Tesi sul tema "Equilibri"

Two main topics are treated in this doctoral thesis from a theoretical and computational point of view: the gas capture and separation from post-combustion flue gases, and the enhanced oil recovery from oil reservoirs. The first topic evaluates the separation of CO2 using three different materials. First, several zeolites from the Faujasite family are studied with a combination of Density Functional Theory (DFT) and Monte Carlo methods. The former is employed to understand the driving mechanisms of adsorption, whereas the latter served to assess the separation of CO2 from a flue gas formed by a ternary mixture of CO2, N2 and O2. Second, the adsorption of CO2, N2 and SO2 into Mg-MOF-74 obtained through DFT calculations is presented to determine the most fundamental gas/MOF interactions. The results are then coupled to a Langmuir isotherm model to derive the macroscopic adsorption isotherms of the three gases in Mg-MOF-74. Finally, the absorption of CO2 and SO2 into three different phosphonium-based Ionic Liquids (ILs) is addressed by using the soft-SAFT equation of state and the COSMO-RS model. From the calculated adsorption/absorption isotherms several properties are obtained, such as the purity in the recovered gas, the working capacity of the materials and their selectivity to capture CO2 in the presence of other contaminant species. The main results obtained from this part of the thesis reveal that the cations of microporous materials are very strong sites of absorption for polar gases (i.e., the Na+ cations in Faujasites or the Mg2+ cations in Mg-MOF-74). This feature makes them very good candidates for CO2 capture, but they can be easily poisoned by other polar gases such as SO2. For this reason, it is highly recommended to desulphurize the flue gas before using any of these adsorbents. Similarly, ILs have higher affinity for SO2 than for CO2. However, the gas/IL interactions are significantly weaker, so they do not become poisoned by SO2. This fact implies that SO2 can be captured and separated from the flue gas by using a phosphonium-based IL. The second topic describes via Molecular Dynamics simulations the interactions of several model oils with different rocks and brines. The obtained insight can be applied in better understanding the interactions of the species present at oil reservoirs, with direct application in enhanced oil recovery processes. To that end, two wettability indicators are monitored to determine the potential recovery of the model oils. First, the oil/water interfacial tension (IFT) under different conditions of temperature, pressure and salinity (i.e., from pure water to 2.0 mol/kg of NaCl or CaCl2). And second, the oil/water/rock contact angle (CA) on calcite (10-14) and kaolinite (001) also as a function of salinity (i.e., from pure water to 2.0 mol/kg of NaCl or CaCl2). The different model oils are built with molecules of different chemical nature representing the Saturate/Aromatic/Resin/Asphaltene (SARA) fractionation model. In a final stage of the doctoral thesis the effect of non-ionic surfactants at the oil/brine IFT is also included. The main results obtained show that the most polar components of oil migrate to the oil/water interface and reduce the IFT. However, the same compounds feel attracted to the rock, who increase the CA and hamper the oil recovery. Some of these interactions are affected by the presence of salt. Specifically, if a water layer is formed between the oil and the rock in a reservoir, electrolytes can diffuse into it and attract the polar components of oil, ultimately increasing the CA. Finally, cations can be attracted to the oil/water interface due to salt/surfactant interactions. Both species interact synergistically to modify their orientation/distribution at the interface and reduce the oil/water IFT.
En aquesta tesi doctoral s’han tractat dos temes principals des d’una perspectiva teòrica i computacional: la captura i separació de gasos de post-combustió, i la recuperació millorada de petroli. El primer tema avalua la separació de CO2 utilitzant tres materials diferents. Primer, s’han estudiat diverses zeolites de la família de les Faujasites amb una combinació de teoria del funcional de la densitat (TFD) i mètodes Monte Carlo per entendre els mecanismes d’adsorció separació de CO2 d’una mescla ternària que conté CO2, N2 i O2. Seguidament, s’ha presentat un estudi TFD d’adsorció de CO2, N2 i SO2 en Mg-MOF-74 per determinar les interaccions fonamentals del MOF amb cada gas. Aquesta informació s’ha acoblat a un model d’isoterma de Langmuir per tal de derivar les isotermes d’adsorció macroscòpiques dels tres gasos en Mg-MOF-74. Finalment, s’ha analitzat l’absorció de CO2 i SO2 en tres Líquids Iònics (LIs) basats en fosfoni mitjançant l’equació d’estat soft-SAFT i el model COSMO-RS. D’altra banda, el segon tema descriu les interaccions de diferents models de petroli amb roques i salmorres, via simulacions de Dinàmica Molecular. El coneixement adquirit en aquesta part de la tesi doctoral es pot aplicar directament a la recuperació millorada de petroli i per entendre millor les interaccions de les espècies presents als pous. Amb aquesta finalitat, s’han controlat dos indicadors de la mullabilitat per determinar la recuperació potencial d’aquests models de petroli. Primer la tensió interfacial (TIF) oli/aigua sota diferents condicions de temperatura, pressió i salinitat (des d’aigua pura a 2.0 mol/kg de NaCl o CaCl2). I segon, l’angle de contacte oli/aigua/roca en calcita (10-14) i caolinita (001) en funció de la salinitat (des d’aigua pura a 2.0 mol/kg de NaCl o CaCl2). Els diferents models de petroli s’han construït amb molècules de diferent naturalesa química representant el model de fraccionament Saturat/Aromàtic/Resina/Asfaltè (SARA). En una etapa final de la tesi doctoral s’ha inclòs l’efecte en la TIF induïda pels surfactants no-iònics a la interfase oli/salmorra.

Il seguente lavoro di tesi tratta l'argomento delle aste in modo tecnico, ovvero cerca di descriverne i modelli e le caratteristiche principali, spesso ignorate dagli stessi fruitori. Nel capitolo 1 si introduce brevemente il concetto di asta, descrivendone i principali elementi costitutivi. Si ripercorrono poi le origini di questa procedura ed alcuni suoi utilizzi. Nel capitolo 2 si presentano inizialmente le principali tipologie di aste conosciute e si accenna al processo di valutazione dell'oggetto d'asta. Si introduce poi il concetto di Private Value, analizzandolo per ogni tipo di asta e confrontando queste sotto l'aspetto della rendita. Si enuncia in seguito un principio fondamentale, quale quello dell'equivalenza delle rendite, rilassandone alcuni assunti basilari. Infine si passa al concetto di valori interdipendenti all'interno delle aste, valutandone equilibri, rendite ed efficienza, accennando nel contempo al problema denominato Winner's curse. Nel capitolo 3 si parla dei meccanismi di asta online, ponendo l'attenzione su un loro aspetto importante, ovvero la veridicità, ed analizzandoli attraverso l'analisi del caso peggiore e del caso medio in alcuni esempi costruiti ad-hoc. Nel capitolo 4 si descrivono in particolare le sponsored search auctions, narrandone inizialmente la storia, e successivamente passando all'analisi di equilibri, rendite ed efficienza; si presenta, infine, un modello di tali aste mettendone in rapporto la computabilità con quella dei meccanismi offline conosciuti.

L'obiettivo di questa tesi è quello di applicare alcune nozioni tipiche dei sistemi dinamici discreti a una situazione economica. Si considerano vari casi di oligopolio, secondo il modello di Cournot, e si osserva che un sistema di n competitori inizia a essere instabile con l'aumentare di n. Si approfondisce poi il caso di un duopolio simmetrico in cui i competitori hanno limitate capacità produttive. Se ne studiano i punti di equilibrio e la loro stabilità e, considerando la funzione di reazione, si osserva che le variazioni degli attrattori prodotte da cambiamenti dei parametri nella funzione dei costi sono dovute alle border-collision bifurcations, cioè all'urto di tali attrattori con le discontinuità della funzione di reazione. Si danno in ultimo alcuni strumenti per trovare i bacini di attrazione.

TRUNK BALANCE AS A PREDICTOR OF MOTOR OUTCOME IN PATIENTS WITH STROKE

ABSTRACT

Background: The search for predictors of functional stroke outcome has always been matter of research in Physical Medicine and Rehabilitation. Outcome prediction at an early stage enables clinicians not only to inform patients and their families, but also to set realistic therapeutic goals. A lot of prognostic studies have evaluated several factors, which either individually or in combination claim to predict functional outcome in stroke. The Trunk Control Test (TCT) proposed by Collin & Wade administered at 6 weeks post-stroke is a predictor of the walking ability at 18 weeks. The TCT reliability and validity has been demonstrated in stroke patients, as well as its positive correlation with disability at hospital discharge from in-patient rehabilitation measured with the Functional Independence Measure (FIM).
In a previous study, a predictive model which only includes the FIM and the TCT measured at admission of patients to a rehabilitation ward, predicts 66.5% of the variability of the functional level at discharge (total FIM).

Objective: To develop an early model to predict motor function (disability, walking ability and balance)at 6 months, taking into account the TCT and other valid predictors evaluated in the first and second week after suffering a stroke.

Patients and Methods: Seventy-five consecutive patients with first stroke who were admitted to a rehabilitation hospital were studied. Sex, age, the stroke type, urinary incontinence, the National Institutes of Health Stroke Scales (NIHSS) and the TCT scores (assessed at first and second week post-stroke) as independent variables. Motor function outcome at 6 months after stroke is defined by the use the Rankin score, the motor FIM and the Berg Balance Scale (BBS).

Results: Older patients, women and those with initial urinary incontinence and lower TCT and NIHSS scores showed significantly worse motor outcomes at first and six months after the stroke (Rankin, motor FIM and BBS). A multiple regression reveals that only age and the TCT (at 14 days after stroke) accounts for the 61.1% of the variance in the motor FIM score at 6 months after stroke. When the TCT is registered at 7 days after stroke, age and the TCT accounts for the 51.7% of the motor FIM variance. A cluster analysis identifies 12 patients with low outcome scores: Rankin 4-5, motor FIM < 59 and BBS < 5. The ROC curves show a better prediction ability for the TCT than the NIHSS at 14 days after stroke. Logistic regression is used to predict the probability of achieving in this group with low motor scores. The TCT  50 at 14 days after stroke is a significant predictive factor of poor motor outcome at 6 months after stroke (Sensibility 83.3%, Specificity 85.7%) (OR=30.0, 95% CI 4.7 - 247.3). The TCT  24 at 7 days after stroke is a significant, but obviously worse predictive factor of poor motor outcome (Sensibility 66.7%, Specificity 89.3%) (OR=16.7, 95% CI 3.2 - 97.5).

Discussion and conclusions: Age, sex, urinary incontinence, TCT and NIHSS scores are related with disability, balance and walking ability six months after the stroke. It is possible to approach to the motor functional outcome at 6 months after stroke by the early use of data easily recorded as age and the TCT. In this study the TCT even overcomes the NIHSS, a comprehensive neurological measure whose ability to predicts outcome has been well documented in stroke patients. The reproducibility of this model must be cross-validated in future studies. The TCT registered at 14 days provides better prediction values compared with those obtained at 7 days after stroke. This study shows that the TCT early administered predicts motor outcome at six months after stroke.


EQUILIBRI DE TRONC: PREDICTOR DE LA FUNCIÓ MOTORA EN L'HEMIPLÈGIC VASCULAR RESUM

Introducció: La cerca de factors predictors del resultat funcional després de patir un ictus és objecte constant d'investigació en Medicina Física i Rehabilitació. Un pronòstic funcional en fases inicials permet al clínic informar als pacients i a la seva familia, però també establir objectius terapèutics realistes. Molts estudis han avaluat la capacitat predictora de diferents factors individual i combinadament. El Test de Control de Tronc (TCT) registrat a les 6 setmanes de l'ictus és un predictor de la capacitat de marxa a les 18 setmanes. La fiabilitat i validesa del TCT s'ha demostrat en pacients amb ictus, així com la seva correlació positiva amb la discapacitat a l'alta hospitalaria. Un model predictiu que inclou només el TCT i el Functional Independence Measure (FIM) registrats a l'ingrés en la unitat de rehabilitació d'hospitalització aguda prediu el 66.5% de la variabilitat del FIM a l'alta.
Objectius: Conèixer la relació de les variables predictores amb els resultats de funció motora global al mes i als sis mesos de l'ictus. Construir un model de predicció precoç de la funció motora (discapacitat, capacitat de marxa i equilibri) als 6 mesos, tenint en compte el TCT i altres predictors vàlids avaluats en la primera i en la segona setmana després de patir l'ictus.
Pacients i Mètode: estudi longitudinal i prospectiu en 75 pacients consecutius ingressats per un primer episodi d'ictus. Les variables independents van ser: edat, sexe, tipus d'ictus, incontinencia urinària, l'escala d'ictus National Institutes of Health Stroke Scales (NIHSS) i el TCT (recollits en la primera i segona setmanes de l'ictus). Els resultats de funció motora al mes i als 6 mesos de l'ictus es van definir amb l'escala de Rankin, la subescala motora del FIM i l'escala d'equilibri Berg Balance Scale (BBS).
Resultats: els pacients de més edat, les dones i els que tenen incontinència urinària inicial i puntuacions més baixes de TCT i NIHSS són els que presenten significativament pitjors resultats de funció motora tant en el primer com en el sisè mes de l'ictus (Rankin, FIM motor i BBS). Una anàlisi de regressió múltipla determina que només amb l'edat i el TCT de la segona setmana s'explica el 61.1% de la variabilitat del FIM motor als 6 mesos de l'ictus. Quan el TCT es registra en el setè dia de l'ictus, l'edat i el TCT expliquen el 51.7% de la variabilitat del FIM motor. Una anàlisi de conglomerats identifica 12 pacients amb resultats baixos de funció motora: Rankin 4-5, FIM motor < 59 i BBS < 5. Les corbes ROC mostren que la millor capacitat predictora correspon al TCT de la segona setmana, per sobre del NIHSS. La probabilitat de tenir un mal resultat motor, es a dir, d'estar entre aquests 12 pacients es calcula mitjançant una anàlisi de regressió logística. Un TCT  50 en la segona setmana de l'ictus és un factor predictiu de mal resultat motor als 6 mesos (Sensibilitat 83.3%, Especificitat 85.7%) (OR=30.0, IC 95% 4.7 - 247.3). Un TCT  24 en la primera setmana també és un factor predictor significatiu, tot i que menys potent, de obtenir un mal resultat motor als 6 mesos (Sensibilitat 66.7%, Especificitat 89.3%) (OR=16.7, IC 95% 3.2 - 97.5).
Conclusions: L'edat, el sexe, la incontinència urinària, el TCT i el NIHSS inicials són factors relacionats amb la discapacitat, equilibri i capacitat de marxa 6 mesos després de l'ictus. És possible aproximar-nos al resultat funcional motor als 6 mesos després de patir l'ictus amb la utilització precoç de dades de fácil recollida com l'edat i el TCT. El TCT recollit en fases inicials prediu el resultat motor als 6 mesos de l'ictus.

L'objectiu últim d’aquesta memòria és la descripció qualitativa i quantitativa de totes les transicions termodinàmiques i conformacionals lligades als equilibris àcid-base d’alguns polinucleòtids en ambients biològics de polaritat baixa. L’emulació d’aquests ambients especials s'ha dut a terme fent ús de mescles aigua-dioxa que mantenen la natura aquosa dels medis biològics i al mateix temps presenten la baixa polaritat desitjada gràcies a les propietats del cosolvent orgànic. La complexitat associada al caràcter macromolecular dels polinucleòtids i al fet d'utilitzar dissolvents mixtos ha aconsellat la realització de certs estudis fonamentals abans de tractar especificament el problema dels equilibris àcid-base dels polinucleòtids en mescles aigua-dioxa. Aquests estudis han inclòs, d'una banda, la caracterització detallada de les mescles aigua-dioxa i la interpretació de llur efecte sabre els equilibris àcid-base de soluts senzills d'altra banda, l'estudi de les unitats monòmeres dels polinucleòtids en aquestes mescles. Un punt constant d'interès en tot el treball que s'ha realitzat ha estat l’assoliment de la màxima qualitat en el tractament de les dades experimentals. En aquest sentit, han merescut una atenció especial els problemes associats a l’establiment de les relacions lineals d'energia de solvatació (LSER), que són els models que descriuen l'efecte del solvent sobre el comportament del solut, i la interpretació de les dades multivariants precedents del seguiment dels equilibris dels polinucleòtids. El primer problema s’ha solucionat amb l’aplicació de diversos mètodes de modelatge dur (hard-modelling) i de modelatge tou (soft­ modelling), mentre per al segon s’ha optat per l’aplicació de mètodes de resolució de corbes, que no necessiten la postulació de cap model químic per a interpretar la variació de les diferents espècies en solució.
The main goal of this project is the qualitative and quantitative description of all the thermodynamical and conformational transitions related to the acid-base behaviour of several polynucleotides in biological environments of low polarity. The emulation of these special environments has been carried out by using water-dioxane mixtures that keep the aqueous nature of the biological media and present the desired low polarity due to the features of their cosolvent. Owing to the complexity associated with the macromolecular nature of the polynucleotides and with the mixed character of the solvent used, some fundamental research must be carried out before facing specifically the research about the acid-base polynucleotide behaviour in water-dioxane mixtures. These previous studies include, on one hand, the detailed characterization of the water-dioxane mixtures and the interpretation of their effect on the acid-base behaviour of single solutes and, on the other hand, the study of the monomeric units of the polynucleotidesin these mixtures. In all the work performed, the careful treatment of the experimental data has been a constant concern. Special attention has been focused on the establishment of Linear Solvation Energy Relationships (LSER), behaviour models that relate the solute behaviour to the solvent effect, and on the interpretation of the multivariate data coming from the monitoring of the macromolecular equilibria of polynucleotides. The former problem has been tackled by using different kinds of bard-modelling and soft-modelling methods, whereas the latter has been solved with the application of curve resolution methods which do not need the postulation of any chemical model to interpret the variation of the different species in solution.

La majoria dels aparells electrònics utilitzats avui en dia tenen components basats en materials semiconductors, els quals poden ser utilitzats en un ampli rang d’aplicacions, des de transistors fins a generadors termoelèctrics o fotovoltaics. Per tal de millorar el rendiment d’aquests aparells i reduir-ne la mida és necessari conèixer la física dels materials que el formen. Quan la mida es redueix, les propietats físiques dels materials canvia, i en especial la transferència de calor a través dels dispositius. Canvis en la temperatura poden afectar directament totes les altres propietats físiques. En aquesta tesi, el transport tèrmic és analitzat des de material bulk (mides grans) fins la nanoescala sota diferents aproximacions utilitzant primers principis. Per una banda, la conductivitat tèrmica en bulk s’estudia en el marc cinètic-col·lectiu, on l’equació de transport de Boltzmann (BTE) per fonons es soluciona en el model de Guyer i Krumhansl. Aquesta solució es coneguda com Kinetic Collective Model (KCM, model cinètic col·lectiu). El KCM, el qual separa la conductivitat tèrmica en una contribució cinètica i una col·lectiva, ha permès obtenir la conductivitat tèrmica d’un gran nombre de semiconductors, coincidint perfectament amb altres solucions actuals de la BTE, i el que és més important, amb dades experimentals. Per altra banda, per mostres de mida petita, s’han considerat dues aproximacions per estudiar els efectes de la superfície. En primer lloc s’ha utilitzat una aproximació cinètica-col·lectiva. En aquest cas, en el règim cinètic, els efectes de superfície es consideren com un mecanisme microscòpic de col·lisions, mentre que en el règim col·lectiu es calculen tenint en compte consideracions hidrodinàmiques. La limitació d’aquesta aproximació per geometries complexes ha promogut el desenvolupament del segon cas: un marc completament hidrodinàmic de transport tèrmic. Una equació hidrodinàmica de transport s’ha desenvolupat a partir del model de Guyer i Krumhansl i de la termodinàmica irreversible estesa (EIT). Aquesta equació hidrodinàmica s’ha utilitzat en primer lloc per estudiar geometries simples com nanofils amb un model de conductivitat tèrmica efectiva. A més, la utilització de condicions de contorn genèriques ha permès utilitzar la equació hidrodinàmica del KCM en càlculs d’elements finits per estudiar geometries complexes. Finalment s’ha fer un anàlisi de l’espectre de fonons i s’ha proposat la seva importància a l’hora de tractar processos transitori. Tots els temes tractats en aquesta tesi en l’àmbit del KCM s’han discutit i comprat amb altres models de transport tèrmic. Paral·lel al desenvolupament del model hidrodinàmic, les expressions de transport en l’aproximació de superfície cinètica-col·lectiva així com paràmetres hidrodinàmics s’han implementat en un software de codi lliure. Compartir el model com a eina per predir el transport tèrmic permetrà establir ponts entre la física del transport tèrmic des del punt de vista microscòpic al macroscòpic.
Most of the daily life devices and electronic tools have components based on semiconductor materials, which can be used for a wide range of applications, from transistors to photovoltaic or thermoelectric energy sources. The improvement of these devices requires a full knowledge of the materials involved. When the size is reduced the physical properties of the materials change, and especially the heat transfer trough the devices. Changes in the temperature can affect directly other physical properties. In this thesis, thermal transport is analyzed from the bulk to the nanoscale under different approaches using first principles. On one side, the bulk thermal conductivity is studied in the general kinetic-collective framework, where the Boltzmann Transport Equation (BTE) for phonons is solved under the Guyer and Krumhansl model and maximizing the entropy of the system. This solution is known as Kinetic Collective Model (KCM). The KCM, which splits the thermal conductivity into a kinetic and a collective contribution, has allowed obtaining the thermal conductivity of a large number of semiconductors, with excellent agreement to other current solutions of the BTE and, more importantly, to experimental results. On the other side, for reduced size samples, two approaches has been considered in order to study size effects. In the first case, a kinetic-collective boundary approach is used. In this approach, in the kinetic regime the boundary is considered as a microscopic scattering mechanism, while boundary effects in the collective contribution are included from a hydrodynamic basis. The limitation of this approach for complex geometries has prompted the development of the second case: a full hydrodynamic thermal transport framework. A hydrodynamic thermal transport equation has been developed from the Guyer and Krumhansl model and the Extended Irreversible Thermodynamics (EIT) framework. This hydrodynamic equation has been applied to study simple geometries from an effective thermal conductivity model. In addition, the use of general hydrodynamic boundary conditions has allowed using the hydrodynamic KCM equation in finite elements calculations to study complex geometries. Finally, an analysis of the phonon spectrum and its importance to deal with transient transport regimes is proposed. Comparisons of the KCM results with other current solutions concerting all the topics of the thesis are discussed. Parallel to the development of the hydrodynamic model, the KCM expressions from the kinetic-collective boundary approach as well as hydrodynamic parameters have been implemented in an open source code. Sharing the model as a tool to predict thermal transport phenomena will allow bridging the physics of the heat transport from the microscopic to the macroscopic point of view.

El disulfur de carboni (CS2) és un solvent utilitzat, per exemple, en la fabricació de cel·lulosa, de fibres de viscosa i esponges. La seva co-exposició amb el soroll és freqüent. S’ha demostrat que l’exposició professional al CS2 pot provocar pèrdua d’audició en les baixes freqüències i trastorns de l’equilibri quan el soroll està també present. No obstant, els efectes del CS2 sobre la còclea i el vestíbul actualment encara es desconeixen. L’objectiu principal és estudiar els efectes de l’exposició al CS2 juntament amb el soroll ric en baixes freqüències sobre el sistema auditiu i el sistema vestibular amb la finalitat de determinar (1) si la toxicitat del CS2 és central i/o perifèrica, i si en realitat es veu agreujada per la co-exposició al soroll, (2) si la toxicitat del CS2 és similar i/o comparable a nivell del sistema auditiu i el sistema vestibular, (3) si els efectes nocius del CS2 sobre la funció auditiva i vestibular són temporals o permanents, (4) si es pot establir una relació entre les conseqüències de l’efecte tòxic del solvent en termes funcionals i patològics. Per respondre a totes aquestes preguntes, es van exposar rates Long Evans femelles a diferents concentracions de CS2 per inhalació, i a un soroll ric en baixes freqüències durant diverses setmanes. Els efectes temporals i permanents d’aquestes exposicions es van avaluar a través de l’estudi de la funció vestibular (nistagme post-rotatori i testos de comportament) i de la funció auditiva (productes de distorsió acústica), així com una anàlisi histològica de l’orella interna i de l’expressió de gens característics de neurotoxicitat en el cerebel. Igualment, al final del període d’exposició, es va portar a terme la determinació de la concentració del tòxic i dels seus metabòlits. Els resultats principals són els següents: (1) L’exposició de rates al CS2, a partir de 250ppm, va ampliar el rang de freqüències afectades pel soroll de baixes freqüències, però va disminuir la pèrdua auditiva dins de la gamma ja alterada pel soroll. Aquest darrer efecte era més remarcable quan les exposicions al CS2 eren intermitents. (2) A més, el CS2 va provocar una disminució de la duració i el nombre de sacades del nistagme la qual cosa s’agreuja quan també està present el soroll. Aquests efectes són reversibles en 4 setmanes a baixes concentracions, però persisteixen a 500ppm. (3) Les anàlisis del comportament i histològiques (còclea i vestíbul) així com la quantificació dels marcadors neurotòxics en el cerebel, no van revelar cap canvi evident. En les nostres condicions, el CS2 no apareix com un agent ototòxic en rates, la seva administració sola no comporta alteracions evidents sobre els sistemes perifèrics auditiu ni vestibular. No obstant això, a causa d’una probable acció sobre el sistema nerviós central, el CS2 té la capacitat d’alterar ambdós sistemes, exacerbant els efectes temporals del soroll de manera dosi-depenent (extensió de les pèrdues cap a les altes freqüències i major disminució en els paràmetres del nistagme). Les dades d’aquest estudi no ens permeten conèixer de manera precisa el mecanisme d’interacció del CS2 amb el soroll, de tota manera, l’absència de canvis en la morfologia dels receptors perifèrics, del comportament dels animals i de l’expressió gènica de molts marcadors de neurotoxicitat al cervell suggereixen una modificació neuroquímica transitòria dels arcs reflexos eferents. El model establert en aquest projecte permetrà obtenir, en estudis futurs, molta més informació sobre l’ototoxicitat de diferents compostos en co-exposició amb el soroll, estudiant la toxicitat a través de mesures funcionals del sistema auditiu i del vestibular, així com a través de diferents tests de comportament i l’estudi de la morfologia de l’orella interna.
Carbon disulfide (CS2) is a solvent used in the manufacture of cellulose, viscose fibers and sponges. Co-exposures to CS2 and noise are common. Occupational exposures to CS2 have been shown to cause low-frequency hearing loss and balance disorders when noise was also present. However, the effects of CS2 on the cochlea and the vestibule are still unknown today. The general objective of this work was to study, in a rat model, the effects of CS2 and low frequency noises on the auditory and vestibular systems in order to determine: (1) whether the toxicity of CS2 is central and/or peripheral, and whether it is aggravated by co-exposure to noise, (2) if the toxicity of CS2 is equivalent and/or comparable at the level of the auditory system and the vestibular system, (3) if the deleterious effects of CS2 on auditory and vestibular functions (if any) are temporary or permanent, (4) whether the functional adverse effects of exposures are representative of the histopathological damage (if any). To answer these questions, Long Evans rats were exposed to different concentrations of CS2 and low-frequency noises. The temporary and permanent effects of these exposures were evaluated by measurements of vestibular functions (post-rotatory nystagmus and behavioral tests) and cochlear functions (ototacoustic emissions). Moreover, histological analyses of the inner ear and a quantification of the expression of neurotoxicity genes in the cerebellum were performed. The main results are the following: (1) Exposure to CS2 broadened the frequency range affected by low frequency noise, but decreased hearing loss in the range affected by the noise. This latter effect was more accentuated when the CS2 exposures were intermittent. (2) Exposure to CS2 shortened and decreased the duration and the number of saccades of the nystagmus, these effects being exacerbated when low frequency noise was also present. At low CS2 concentrations, we observed a complete recovery, but these effects persisted at the highest concentration. (3) The behavioral and histological analyses (vestibule and cochlea), as well as the quantification of the neurotoxic markers in the cerebellum, did not reveal any major change. In the experimental context of this study, CS2 did not appear ototoxic in rats. However, due to a probable action on the central nervous system, it could exacerbate the temporary effects of noise on both systems. The data of this study do not allow us to know the precise mechanism of interaction of CS2 with the noise. However the absence of histological modifications in the peripheral receptors, of behavioral changes, as well as the lack of major changes in markers of neurotoxicity in the brain, suggest a temporary neurochemical modification of the efferent reflex arcs.

La presente tesis compila el resultado de cuatro estudios siguiendo una línea de investigación. Los cuatro articulos han sido publicados. Esta línea tiene una vertiente metodológica y otra clínica, ya que se han utilizado tres tipos de estudios, como son las revisiones sistemáticas (RS), los estudios de validación y el ensayo clínico aleatorio (ECA), sobre un tema en común como son los trastornos del equilibrio y control del tronco en pacientes que han experimentado un ictus. En las siguientes páginas se pone en contexto el problema del ictus y sus secuelas, con un especial énfasis en la debilidad muscular y las alteraciones de la sensibilidad, lo cual conduce a deficiencias en el control postural y equilibrio. El control postural es una habilidad muy compleja; en la que intervienen diferentes sistemas, y que resulta imprescindible para una vida independiente, para la realización de cualquier tarea de la vida diaria y en la deambulación. En esta tesis se aborda una línea de investigación para mejorar dichas deficiencias, como es un enfoque fisioterapéutico basado en ejercitar y potenciar la musculatura central del cuerpo o Core. El primer trabajo de investigación consistió en la realización de una RS para analizar qué evidencia existía hasta el momento referente a la efectividad de los ejercicios de tronco o de Core Stability para mejorar el equilibrio en sedestación y control de tronco en los pacientes que han sufrido un ictus. La revisión sirvió para constatar las deficiencias metodológicas de los ECAs realizados hasta la fecha, así como para detectar la ausencia de escalas validadas a la lengua española, para evaluar el equilibrio en sedestación y control postural en este tipo de pacientes. A partir de la revisión y en base a las deficiencias detectadas se diseñó un ECA para evaluar el efecto de los ejercicios de Core Stability en la población que ha sufrido su primer ictus y se encuentra en la fase subaguda (≤ 3 meses). Así mismo dos escalas utilizadas en el ECA y de uso frecuente en neurología, fueron validadas a la lengua española.

Progressive ototoxicity of the inner ear is prevalent in patients administered aminoglycoside antibiotics with little understanding of how this damage occurs and to what extent it can be recovered. Numerous in vitro and in vivo studies using acute methods have been completed to demonstrate various types of damage in vestibular and auditory tissue, including hair cell damage that results in apoptosis or necrosis, excitotoxic damage, and/or degeneration of their afferents. However, progressive damage has only just recently been studied utilizing a sub-chronic exposure rat model; this model takes into account the progressive exposure mirrored in aminoglycoside administration that is not implied in acute experimentation. With this in mind, the sub-chronic exposure model was adapted for a new mouse model to characterize the progressive damage taking place in vestibular sensory epithelia and ganglia, along with a preliminary characterization in cochlear sensory epithelia. Mice were exposed to 30 mM IDPN (3,3’- iminodipropionitrile) in regular drinking water for 8 weeks, and monitored for vestibular deficits using an established test battery; auditory deficits were recorded using auditory brainstem response (ABR) measurements. Various techniques for identifying functional, histological (scanning/transmission electron microscopy; immunoconfocal), and molecular (mRNA; protein) data were utilized to study alterations in the vestibular and auditory tissues after sub-chronic intoxication. In the vestibular tissue, SEM/TEM imaging demonstrated progressive damage with the loss of calyceal junctions between type I hair cells and their calyx afferents, the fragmentation and retraction of the afferents, stereociliary bundle coalescence, and the unique mechanism of hair cell extrusion, where the cell is ejected from the epithelia into the endolymphatic cavity. Immunoconfocal and qRT-PCR data demonstrated a loss of caspr1 and tenascin-c in the calyceal junctions of type I hair cells and their afferents. A loss of active synapses between hair cells and their afferents was also noted, where active synapses were defined by the pre-synaptic ribeye of the hair cells and the post-synaptic GluA2 receptor of the afferents. Synaptic scaffolding protein expression was upregulated (PSD95, Homer1), which translated into an increase in the protein level (PSD95), likely for hair cell-afferent synapse stabilization and compensation. Progressive damage was noted to be at least partially or completely recoverable up until stereocilia coalescence of the hair cells. Finally, the expression of numerous scaffolding and signaling proteins were shown to be downregulated (qRT-PCR; RNAseq) during the exposure in the vestibular epithelium and ganglion, leading to the hypothesis of a depression in cell-cell adhesion between hair cells and their afferents and a depression in afferent signaling, resulting in an overall depressed system. In the cochlea, profound hearing loss was observed in a tonotopic pattern during the exposure; higher frequencies were affected first with longer exposure times affecting lower frequencies. Outer hair cells were lost tonotopically due to prolonged exposure, followed by active synapse loss of the inner hair cells. Those intoxicated for the first two weeks demonstrated a capacity for recovery before any outer hair cell or active synapse losses were seen. A sub-chronic ototoxic IDPN model demonstrates the progressive damage of the inner ear, allowing for the study of this damage and its potential for recoverability, gaining a clearer understanding of the mechanisms affecting the tissues.
La ototoxicidad progresiva del oído interno prevalece en los pacientes a los que se les administraron antibióticos aminoglucósidos con poca comprensión de cómo se produce este daño y hasta qué punto se puede recuperar. Se han completado numerosos estudios in vitro e in vivo para demostrar diversos tipos de daño en el tejido vestibular y auditivo; recientemente, se ha estudiado el daño progresivo utilizando un modelo de intoxicación subcrónica en rata. Este modelo tiene en cuenta la exposición progresiva reflejada en la administración de aminoglucósidos que no está implícita en los experimentos agudos. El modelo de intoxicación subcrónica se adaptó a un nuevo modelo de ratón para describir como se caracteriza el daño progresivo que se produce en los epitelios sensoriales vestibulares y los ganglios, junto con una caracterización preliminar en los epitelios sensoriales cocleares. Los ratones se expusieron a IDPN 30 mM (3,3'-iminodipropionitrilo) en agua potable normal durante 8 semanas y se observaron los déficits vestibulares utilizando una batería de pruebas establecida; los déficits auditivos se registraron utilizando medidas de respuesta auditiva del tronco cerebral. Se utilizaron diversas técnicas para estudiar las alteraciones en los tejidos vestibular y auditivo después de una intoxicación subcrónica. En el tejido vestibular, demostró un daño progresivo con la pérdida de las uniones calíceas entre las células ciliadas tipo I y sus aferentes del cáliz, la fragmentación y retracción de los aferentes, la coalescencia estereociliar y el mecanismo único de extrusión de células ciliadas. También se observó una pérdida de sinapsis activas y se demostró que la expresión de numerosas proteínas de andamiaje y señalización estaba regulada a la baja durante la intoxicación. En la cóclea, se observó una pérdida auditiva profunda en un patrón tonotópico durante la exposición y las células ciliadas externas se perdieron tonotópicamente debido a la exposición prolongada, seguida de la pérdida activa de sinapsis de las células ciliadas internas. Un modelo de IDPN ototóxico subcrónico demuestra el daño progresivo del oído interno, lo que permite el estudio de este daño y su potencial de recuperación, obteniendo una comprensión más clara de los mecanismos que afectan a los tejidos.

En esta investigación, hemos documentado y capturado el CDC de dos grupos de profesores para el tema del equilibrio químico. Cuatro de ellos son maestros de bachillerato universitario y los otros son profesores de licenciatura en la Facultad de Química de la Universidad Nacional Autónoma de México. Para documentar el CDC, se decidió utilizar la metodología propuesta por Loughran y compañeros de trabajo. Las ideas centrales seleccionadas por los profesores de bachillerato son diferentes de las elegidas por los maestros universitarios, el análisis de los datos muestra que ambos grupos consideran a la abstracción como uno de los retos más importantes en la enseñanza y el aprendizaje de equilibrio químico. Se menciona que los estudiantes no conciben los procesos simultáneos, asumen que termina primero la reacción hacia adelante y luego el proceso se invierte. Los procedimientos de enseñanza más comunes son experimentos y analogías. Los exámenes de ejercicios de lápiz y papel siguen siendo la forma preferente de evaluación del conocimiento. Cabe destacar el hecho de que no se hace uso de secuencias de enseñanza-aprendizaje, y los argumentos cinéticos siguen siendo el marco de la construcción de concepto.
In this study we documented and portrayed the PCK of two groups of teachers for the chemical equilibrium topic. Four of them are high school teachers and the others are undergraduate teachers at the National Autonomous University of Mexico. To document the PCK, we decided to use the methodology proposed by Loughran and coworkers. The central ideas selected by high school teachers are different from those chosen by undergraduate teachers, the analysis of CoRes shows that both groups consider the abstraction as one of the most important challenges for teaching and learning chemical equilibrium. It is mentioned that the students do not conceive the simultaneous processes, they assume that ends first the forward reaction and then the process reverses. The teaching procedures more commons are experiments and analogies. Tests are still the form of assessment of knowledge. Of note is the fact that no use is made of teaching-learning sequences and also the kinetic arguments are still the framework of the concept construction.

La fibromialgia (FM) es un síndrome crónico caracterizado por dolor generalizado, fatiga, sueño no reparador, quejas somáticas y alteraciones afectivas y cognitivas. Aunque existe evidencia reciente indicando que las emociones negativas pueden desempeñar un papel modulatorio relevante para el mantenimiento de los síntomas de la FM, poco se conoce de la influencia de los polimorfismos genéticos sobre la función motora, el sueño y el procesamiento afectivo en fibromialgia. El objetivo principal de esta tesis fue analizar la influencia del polimorfismo val158met del gen de la COMT, que se encuentra asociado a la actividad enzimática de la degradación de catecolaminas, sobre la marcha y el equilibrio, el sueño y la regulación emocional. Para ello, se ha adoptado un enfoque multidisciplinar en el que se ha tenido en cuenta parámetros biomecánicos de la función motora, la actividad cerebral durante el sueño y durante la modulación afectiva del reflejo de sobresalto para comparar individuos que muestran bien una baja o una alta actividad de COMT (homocigotos met y portadores del alelo val, respectivamente). La función motora fue evaluada mediante el análisis de la marcha y el equilibrio con grabaciones de videos en personas sanas y pacientes con FM (estudio 1). Además, dos subgrupos de pacientes con FM basados en el polimorfismo de la COMT participaron en un registro nocturno de polisomnografía (estudio 2) y una tarea experimental con la presentación de estímulos acústicos de sobresalto durante la visualización de imágenes afectivas (estudio 3). El estudio 1 mostró que las pacientes con FM presentan una reducción significativa en los parámetros de la marcha tales como velocidad, longitud del paso y del paso completo, o la cadencia, así como déficits en el control postural y el equilibrio. El estudio 2 reveló que las pacientes con FM y baja actividad de la enzima COMT parecen estar más impactadas físicamente, más deprimidas y con peor calidad de sueño (mayor número de despertares durante la noche, mayor tiempo en la cama y sueño más fragmentado durante la fase REM) que las pacientes con FM y alta actividad de la enzima COMT. Por último, el estudio 3 mostró que las pacientes con FM y baja actividad de la enzima COMT presentan alteraciones significativas de los componentes tempranos de la actividad cerebral desencadenada por estímulos agradables y desagradables comparadas con las pacientes con FM y alta actividad de la COMT. Estos estudios sugieren: 1) que la marcha y el equilibrio se encuentran alterados en las pacientes con FM comparadas con personas sin dolor, y 2) que el sueño y el procesamiento afectivo en las pacientes con FM puede ser modulado por el polimorfismo val158met del gen de la COMT que regula la actividad enzimática de las catecolaminas. En resumen, estos hallazgos proporcionan un apoyo adicional a la idea de que los síntomas de la fibromialgia precisarían de una evaluación y de una intervención terapéutica de carácter multidimensional con el objetivo de proporcionar las óptimas condiciones para la mejora de la calidad de vida de estos pacientes. Asimismo, estos hallazgos subrayan la relevancia de considerar marcadores genéticos y neurofuncionales para una compresión más completa del síndrome de fibromialgia.
La fibromialgia (FM) és una síndrome crònica caracteritzada per dolor generalitzat, fatiga, son no reparador, queixes somàtiques i alteracions afectives i cognitives. Encara que existeixen evidències indicant que emocions negatives poden tenir un paper modulador rellevant en el manteniment dels símptomes de la FM, poc es coneix de la influència dels polimorfismes genètics sobre la funció motora, el son i el processament afectiu en la fibromiàlgia. L’objectiu principal d’aquesta tesi doctoral va ser analitzar la influència del polimorfisme val158met del gen de la COMT, que es troba associat a l’activitat enzimàtica de la degradació de les catecolamines, sobre la marxa i l’equilibri, el son i la regulació emocional. Per això, s’ha adoptat un enfocament multidisciplinari en el qual s’han tingut en conte paràmetres biomecànics de la funció motora, l’activitat cerebral durant el son i durant la modulació afectiva del reflex de sobresalt per comparar subjectes que mostren una baixa o alta activitat de COMT (homozigots met i portadors d’al·lel val, respectivament). La funció motora fou avaluada mitjançant l’anàlisi de la marxa i l’equilibri amb gravacions de video en persones sanes i en pacients amb FM (estudi 1). A més, dos grups de pacients amb FM basats en el polimorfisme de la COMT participaren en un registre polisomnogràfic nocturn (estudi 2), i en una tasca experimental ambla presència d’estímuls acústics de sobresalt durant la visualització d’imatges afectives (estudi 3). L’estudi 1 mostrà que les pacients amb FM presenten una disminució significativa en paràmetres de la marxa com són la velocitat, la longitud de cada pas i del pas complet o cadència, així com dèficits en el control postural i de l’equilibri. L’estudi 2 desvetllà que les pacients amb FM amb baixa activitat de l’enzim COMT pareixen estar més impactades físicament, més deprimides i amb pitjor qualitat de son (major nombre de despertars durant la nit, major quantitat de temps en el llit i un son més fragmentat durant la fase REM), que les pacients amb FM amb alta activitat de l’enzim COMT. Per últim, l’estudi 3 mostrà que les pacients con FM amb baixa activitat de l’enzim COMT presenten alteracions significatives en els components primerencs de l’activitat cerebral desencadenada per estímuls agradables o desagradables, comparades amb les pacients con FM amb alta activitat del COMT. Aquests estudis suggereixen: 1) la marxa i l’equilibri es troben alterats en les pacients amb FM comparades amb les persones sense dolor, i 2) que el son i el processament afectiu de les pacients amb FM port estar modulat pel polimorfisme val158met del gen del COMT que regula l’activitat enzimàtica de les catecolamines. En resum, aquests resultats remarquen encara més la idea de que els símptomes de la fibromiàlgia precisen d’una avaluació i d’una intervenció terapèutica de caràcter multidimensional amb l’objectiu de proporcionar les òptimes condicions per la millora de la qualitat de vida d’aquetes pacients. Així mateix, aquestes troballes subratllen la rellevància de considerar els marcadors genètics i neurofuncionales per a una compressió més completa de la síndrome de fibromiàlgia.
Fibromyalgia (FM) is a chronic syndrome characterized by widespread pain, fatigue, unrefreshing sleep, somatic complaints, and affective and cognitive alterations. Although there is recent evidence indicating that negative affect may play a relevant modulatory role for the maintenance of fibromyalgia symptoms, little is known about how genetic polymorphisms may influence motor function, sleep and affective processing in fibromyalgia. The major goal of the present thesis was to analyze the influence of the val158met polymorphism of the COMT gene which is associated with the enzymatic activity level of cathecolamine degradation on gait and balance, sleep and emotional regulation. For this purpose, a multidisciplinary approach taking into account biomechanical parameters of motor function and parameters of the brain activity during sleep and during affective processing was used to compare individuals displaying either low (met homozygotes) or high COMT activity (val carriers). Motor function was assessed by analyzing gait and balance through video recordings in healthy controls and FM patients (study 1). In addition, two subsamples of FM patients based on the val158met polymorphism participated in a night polysomnography recording (study 2) and an experimental task with presentation of startle noise stimuli when viewing affective pictures (study 3). Study 1 showed that FM patients display a significant reduction in gait parameters such as speed, step length and full step, cadence and etc., as well as deficits in postural control and balance. Study 2 revealed that FM patients with low-activity of the COMT enzyme appear to be more physically impacted and depressed, and to have poorer quality of sleep (greater number of awakenings during the night, longer in bed and more fragmented sleep during REM) than FM patients with high-activity of the COMT enzyme. Finally, Study 3 showed that patients with low-activity of the COMT enzyme display significant alterations of the early components of the event-related brain potentials elicited by pleasant and unpleasant stimuli as compared with FM patients displaying high COMT activity. These studies suggest: 1) that gait and balance are altered in patients with FM compared to pain-free controls, and 2) that sleep and affective processing in FM patients may be modulated by the val158met polymorphism of the COMT gene that regulates the enzyme activity of catecholamines. In summary, these findings provide further support for the notion that FM symptoms would require multidimensional assessment and intervention to provide optimal conditions for improving quality of life in these patients. Moreover, our findings underline the relevance of considering genetic and neurofunctional markers for a complete understanding of fibromyalgia.

La pèrdua de funció del sistema vestibular causa vertigen, pèrdua d’equilibri i pèrdua de mirada fixa durant el moviment, sovint acompanyats de marejos i nàusees. Els trastorns de l’equilibri són comuns a les persones grans i alteren el seu patró de marxa, sent un important factor de risc per a les caigudes. En els éssers humans, una de les causes de pèrdua de funció vestibular és la toxicitat d’alguns fàrmacs, com antibiòtics aminoglicòsids, medicaments antipalúdics, diürètics de nansa, agents quimioterapèutics com el cisplatí, així com una sèrie de productes químics d’exposició laboral. La diana principal de la toxicitat són les cèl·lules ciliades. Estudis d’exposició aguda en animals han demostrat clarament que els components ototòxics poden causar discapacitat permanent perquè causen la degeneració de moltes o totes les cèl·lules ciliades. Aquestes cèl·lules no poden regenerar o ho poden fer de manera limitada en algunes espècies de mamífers com el conill d’Índies i la xinxilla i en qualsevol cas la recuperació funcional és limitada o nul·la. En peixos, amfibis i ocells les cèl·lules ciliades es produeixen i es poden regenerar al llarg de tota la vida. Les noves cèl·lules ciliades procedeixen de les cèl·lules de suport seguides de dos possibles mecanismes: mitosis o transdiferenciació. Aquestes evidències d’estudis experimentals no serveixen per explicar la recuperació funcional que té lloc en els humans després de la interrupció de l’exposició crònica ototòxica. Quan en pacients a qui s’ha diagnosticat ototoxicitat es para el tractament, els resultats són molt variables: des de la persistència completa dels símptomes fins una recuperació incompleta o completa. Encara que la recuperació comportamental es pot explicar en part per fenòmens de compensació al sistema nerviós central, es coneix molt poc sobre els mecanismes cel·lulars i moleculars involucrats en el dany vestibular crònic i la seva possible recuperació, així como la seva rellevància a nivell comportamental. Per a estudiar els processos involucrats en el dany i reparació vestibulars associats amb la ototoxicitat crònica i la subsegüent recuperació, es van exposar rates Long Evans mascles a IDPN (3,3’-iminodipropionitrilo) via l’agua de beguda durant vàries setmanes i es van avaluar al final del període d’exposició i al final d’un període de recuperació. Per a identificar les etapes de dany que són susceptibles de reparació i que poden ser la base de la recuperació funcional, es van examinar les característiques ultraestructurals de les crestes i els utricles. La intoxicació crònica per IDPN provoca pèrdua de les cèl·lules ciliades per extrusió. Per a revelar més característiques ultraestructurals del dany ototòxic i la seva posterior recuperació, així com dels efectes ciliars, es van examinar les crestes per microscòpia electrònica de transmissió. Per a caracteritzar la dinàmica del dany aferent i del procés de reparació, es van estudiar mitjançant immunohistoquímica i microscòpia de fluorescència confocal l’expressió de proteïnes prèviament identificades en el contacte entre el calze aferent i la cèl·lula ciliada de tipus I. El següent pas va ser estudiar que passava amb les cintes de les sinapsis aferents de les cèl·lules ciliades de tipus I i de tipus II. El model d’ototoxicitat crònica induït per IDPN a l’aigua de beguda, causa retracció i fragmentació del calze aferent abans que tingui lloc la mort de les cèl·lules ciliades per extrusió. En aquest treball es presenten les evidències que el desmantellament de les unions septades és un procés anterior al dany aferent durant la ototoxicitat crònica i que l’extensa reparació de les unions septades i del calze aferent són possibles després d’aturar-se l’agressió.
Acute toxic insults to the mammalian vestibular system cause loss of the sensory hair cells and subsequent loss of equilibrium. In animal models, many studies have demonstrated apoptosis, sometimes necrosis, of the hair cells. In most mammalian species the functional loss is permanent because the hair cells do not regenerate. Human vestibular dysfunction most commonly arises progressively as a result of chronic exposure to ototoxic compounds such as the aminoglycoside antibiotics. If the exposure is discontinued, a highly variable degree of recovery is observed, being either complete, only partial, or minimal with persistent dysfunction. The cellular and molecular bases of the vestibular dysfunction associated with chronic toxicity and of its remarkable variability in the degree of recovery are not established. One reason for this limited knowledge is the scarcity of animal studies of chronic vestibular toxicity, owing to, at least in part, the resiliency of rats and mice to aminoglycoside ototoxicity. Ototoxic nitriles offer an alternative model to study vestibular toxicity in these species. A particularly dependable model is the one of chronic drinking water exposure of rats to 3,3’-iminodipropionitrile (IDPN). We have established a protocol to study the vestibular sensory epithelia simultaneously by scanning electron microscopy, transmission electron microscopy and confocal immunofluorescence microscopy in rats previously assessed for vestibular dysfunction during chronic ototoxic exposure followed by variable times of recovery. This allows identifying the structural and molecular events associated with the loss and recovery of vestibular function. Initial data indicate that a deep but fully reversible functional loss is associated with synaptic and afferent damage and intact ciliary structure. With continued IDPN exposure, hair cell damage and more persistent functional are observed. We hypothesize that similar events occur in humans and are relevant to chronic damage, including that associated with age.

El sistema immune gastrointestinal ha de tenir un equilibri entre les respostes tolerogèniques i proinflamatòries per a mantenir la homeòstasi del sistema. Actualment es desconeixen les possibles diferències en la resposta immunitària entre diferents regions intestinals (ili, colon dret, colon esquerre) en condicions de salut i de malaltia. El primer estudi pretén determinar si hi ha diferències entre diferents àrees del budell sa i si es mantenen o no a la mucosa inflamada. A la mucosa sana es detecta un increment de cèl·lules Th17 i Treg al còlon en comparació amb l'íleum terminal, mentre que no hi ha diferències significatives en el percentatge de cèl·lules Th1. A la mucosa inflamada, els nivells de Th1 i Th17 presenten un patró dependent de malaltia i independent de localització. A la malaltia de Crohn (MC) i la colitis ulcerosa (CU) es detecta un increment de cèl·lules Th17, mentre que només a la MC es demostra un increment de la resposta Th1. Totes les formes d'inflamació intestinal (excepte la colitis infecciosa) presenten un gran increment en els percentatges de Treg, independentment de la localització. Els limfòcits atípics doble positius (DP, + + + + - - CD3 CD4 CD8 ) i doble negatius (DN, CD3 CD4 CD8 ) es comporten de manera especular a la mucosa sana en relació amb la localització: es detecta un increment de DP a l'íleum en comparació amb el còlon, mentre que els limfòcits DN són predominants al colon en vers el budell prim. La inversió en percentatge de DP es manté també a la mucosa inflamada, independentment del tipus de malaltia. Contràriament, s'han detectat patrons específics de malaltia en les cèl·lules DN, que es troben incrementades a la colitis microscòpica i reduïdes a la malaltia de Crohn de còlon. A la mucosa sana es detecta un increment en el percentatge de mort cel·lular per apoptosi que s'incrementa en sentit distal (ílium < colon dret < colon esquerre). Contràriament, totes les formes d'inflamació intestinal de colon (incloent la colitis infecciosa) presenten una davallada en els nivells d'apoptosi en comparació amb la mucosa intestinal sana, mentre que la malaltia de Crohn ileal presenta nivells de mort cel·lular per apoptosi superior a la de la mucosa ileal sana El segon estudi pretén determinar les similituds i les diferències en la resposta immunitària de la mucosa entre les dues formes de colitis microscòpica: colitis col·làgena (CC) i + colitis limfocítica (CL). A la CL s'ha observat un increment de les cèl·lules citotòxiques CD8 i + + una reducció dels limfòcits DP i CD4 . Tot i que la població de limfòcits CD4 total es troba + + reduïda, s'ha detectat un increment selectiu de la població CD4 TCRγδ a la CL. L'expressió gènica de la IL-15 es troba incrementada en la CL. Per contra, la CC no ha mostrat diferències amb els controls sans en cap d'aquests paràmetres. Els nivells de IL-10 es troben incrementats a tots els nivells mesurats (expressió gènica, proteïna total de teixit i secretada a sobrenadant de cultiu). Els nivells de cèl·lules Th1 i Th17 són significativament inferiors als detectats en controls sans, malgrat l'augment d'expressió de gens relacionats amb les vies Th1 i Th17. Per tant la CC i la CL comparteixen alguns mecanismes fisiopatològics però difereixen en altres.
BACKGROUND: There is very limited information regarding region-specific immunological response in human intestine and its deregulation in inflammatory conditions. AIMS: To determine differences in immune compartmentalization between ileum and colon in healthy and inflamed mucosa (inflammatory bowel disease, infectious colitis and microscopic colitis) and to identify similarities and differences between the two forms of microscopic colitis (lymphocytic and collagenous colitis). RESULTS: Healthy colon showed higher percentages of Treg, Th17, and double negative T cells, and lower numbers of double positive T cells compared with ileum. Some but not all region-specific differences were lost in inflammatory conditions. Disease-specific patterns were found: a Th1/Th17 pattern in Crohn's Disease and a Th17 pattern in ulcerative colitis, whereas a reduction in Th1/Th17 was found in microscopic colitis. Double negative T cells were reduced in Crohn's Disease and increased in microscopic colitis. Higher levels of lymphocyte apoptosis were found in healthy colon compared to ileum. All forms of colonic inflammation presented a dramatic decrease in lymphocyte apoptosis compared with healthy colon. By contrast, ileal Crohn’s disease + + showed higher levels of cleaved-Caspase CD3 cells. Lymphocitic colitis + patients had lower numbers of CD4 and double-positive mucosal T + + + lymphocytes, and higher numbers of CD8 and CD4 TCRγδ mucosal T cells, coupled with an increase in Interleukin-15 mRNA levels, compared with controls and collagenous colitis patients. By contrast, an increase in Treg cells and in Interleukin-10 levels (mRNA and protein) was found in both collagenous and lymphocytic colitis compared to controls. CONCLUSIONS: Immunological differences exist in healthy gastrointestinal tract. Inflammatory processes overwhelm some location-specific differences, whereas others are maintained. Care has to be taken when analyzing immune response in intestinal inflammation, as location-specific differences may be relevant. Collagenous and lymphocytic colitis share some regulatory and effector mechanisms, but differ in others, suggesting that they are two closely related, but independent intestinal disorders.

El sobrepeso y la obesidad son condiciones patológicas, con una prevalencia elevada, que están consideradas como una de las principales causas de mortalidad. Los factores genéticos, y especialmente, los factores ambientales y los estilos de vida son determinantes para su desarrollo. Existen varias patologías asociadas a la obesidad como la resistencia a la acción de la insulina, la hipertensión, la hiperlipidemia y las enfermedades cardiovasculares, que son las principales comorbilidades del síndrome metabólico. A lo largo de las décadas se han desarrollado infinidad de estudios enfocados en la prevención y el tratamiento de la obesidad y sus complicaciones, la mayoría de ellos relacionados con el control del peso a través de la intervención nutricional, que se basa principalmente en la modificación de la proporción de los macronutrientes de la dieta. Sin embargo, dichas modificaciones conllevan adaptaciones metabólicas que, con la tentativa de mantener la homeostasis en el organismo, pueden comprometer algunas funciones biológicas. En la presente Tesis, se han estudiado algunas de las adaptaciones metabólicas que se producen tras aplicar una intervención nutricional con cuatro dietas distintas durante un mes. La intervención se realizó en ratas Wistar hembra y macho de 10 semanas de edad. Las dietas utilizadas diferían en la proporción y/o la composición de macronutrientes, y a la vez, fueron comparables entre sí al estar ajustadas al resto de componentes. Los resultados obtenidos en relación a la medida de la glucemia indican que las lecturas de glucosa estarían sujetas a una infraestimación sistemática, pudiendo comprometer los criterios diagnósticos. Las medidas de glucemia y glucosilación obtenidas apuntan a una influencia de la dieta sobre la proporción anomérica de la glucosa, y a diferencias en la compartimentación de la glucosa sanguínea; por ello, se sugiere la medida de la glucosilación de las proteínas de membrana de los eritrocitos (debido a su contacto continuado con la glucosa del plasma) como mejor indicador del desarrollo de la hiperglucemia. En relación a los efectos obesogénicos de la dieta, parece que las consecuencias metabólicas no vienen dadas únicamente por un exceso de nutrientes de la dieta sino también por un desequilibrio en su proporción. Se ha observado que la ingesta de componentes sabrosos (dulce/salado) junto con la textura que aporta el lípido, son los principales responsables de la inducción de hiperfagia y el desarrollo de obesidad. La relación lípido / proteína de la dieta influye positivamente en la acumulación de lípido ectópico, siendo esta también diferente entre sexos. Por otro lado, la composición lipídica de la dieta generó efectos importantes en el metabolismo de carbohidratos y de lípidos, que parecen estar mediados por el estradiol. Respecto al metabolismo nitrogenado, la relación energía / proteína de la dieta parece tener un papel clave en la regulación del ciclo de la urea hepático. Ante un exceso energético y proteico simultáneo proveniente de la dieta, el funcionamiento del ciclo y la producción de urea se ven comprometidos, dificultando la excreción de nitrógeno amínico. Por otro lado, la capacidad del tejido adiposo marrón para contribuir a la eliminación de nitrógeno amínico está limitada debido a la presencia parcial del ciclo de la urea, que parece estar relacionado con la síntesis de arginina. Estos hallazgos refuerzan las hipótesis relacionadas con la existencia de mecanismos alternativos para eliminar un superávit de nitrógeno amínico.
Overweight and obesity are pathologic conditions with a high prevalence, and are considered as one of the leading risks for global deaths. Genetic factors, and especially, environmental factors and lifestyle habits are crucial for their development. There are several obesity- associated pathologies, as insulin resistance, hypertension, cardiovascular disease and hiperlipidemia, which are the main comorbidities of Metabolic Syndrome. Over the decades several approaches have been carried out for the prevention and treatment of obesity and its complications. Most of them are related to weight control through nutritional intervention, which is mainly based on macronutrient’s proportion modifications. However, these modifications involve metabolic adaptations for homeostasis maintenance that can compromise some biological functions. Some of those metabolic adaptations have been studied by carrying out a one-month nutritional intervention with four different diets. It has been performed in 10-week old female and male Wistar rats. The diets used differed in macronutrients proportion or composition, and were comparable to each other since the rest of the components were adjusted. The results obtained in relation to glycaemia measurement suggest the existence of a systematic underestimation of glucose readings, which could be compromising the diagnostic criteria. The obtained glycaemia and glycosylation measurements point to an influence of the diet on glucose anomer proportion and to a different blood glucose compartmentalization, suggesting the measurement of red blood cell membrane protein glycosylation (due to its sustained exposure to glucose) as better marker of hyperglycaemia development. Regarding diet obesogenic effects, it seems that the metabolic consequences are not only given by an excess of nutrients from the diet but also by an imbalance in their proportion. It has been observed that the intake of tasty components (sweet / salty) together with lipid texture, are the main responsible factors for hyperphagia induction and obesity development. The lipid / protein ratio of the diets positively influences the accumulation of ectopic lipid, which also exhibited sex-related differences. On the other hand, the lipid composition of the diet promoted important effects on carbohydrate and lipid metabolism, which seemed to be mediated by oestradiol. In relation to nitrogen metabolism, the energy / protein ratio of the diet seems to play a key role in liver urea cycle regulation. When high amounts of energy and protein simultaneously come from the diet, the operation of urea cycle, and so the excretion of nitrogen as urea, is compromised. Furthermore, the capacity of brown adipose tissue to contribute to the nitrogen excess elimination is limited due to its partial urea cycle presence, which may be more related to arginine synthesis. These findings reinforce the hypotheses related to the existence of alternative mechanisms to eliminate the nitrogen surplus.

This PhD thesis is focused in structural aspects of alkali nitrates. In the first chapter, we recollected the most important advancement in this field in alkali nitrates compounds published since 1970. Along this lines, crystal structure, polymorphism and phase transition is discussed first; second, crystal growth, and third, the morphology. And, finally a section concerning solid state miscibility and binary phase diagrams between these compounds is presented. The following chapters present a deeper study of growth morphology and how the impurities affect to the morphology and growth rate. These two topics are closely related because the growth morphology is a consequence of the growth rate ratio of different faces. Evidently, we chose only one compound of all the alkali nitrate family. It turned to be sodium nitrate, nitratine or NaNO3. First, in chapter 2, we calculate the morphology of nitratine by applying the two most common approaches to determine the theoretic morphology of crystals: the Bravais-Friedel-Donnay-Harker (BFDH) methodology and the periodic bond chains (PBCs) procedure proposed by Hartman and Perdok (HP). Then we compare the obtained morphology with the experimental growth shape. This compound is interesting from the morphological and structural point of view because it is isostructural with calcite, a calcium carbonate (CaCO3) polymorph. This fact will permit us to discuss how the charges affect the final crystal morphology; an introduction to this question is in chapter 2. In chapter 3 we sought to determination of the normal growth rates (R104) of {104} faces of sodium nitrate single crystals under isothermal conditions in the temperature interval 288 K  297.5 K and hence find the most probable growth mechanisms. Chapter 4 is devoted to the morphology change in NaNO3 crystals by the effect of impurities. It is followed by an atomic force microscopy (AFM) investigation of heterogeneous nucleation of nitratine on calcite in chapter 5. Finally, the NaNO3 – KNO3 phase diagram has been studied from both experimental and theoretical aspects in chapter 6.

The objective of this doctoral thesis is to apply different multisectorial models available to analyse the impact that would had on the Catalan economy as a result of the introduction of policies designed to reduce emissions of greenhouse effect gases and save energy, and also at the same time to improve the environmental competitiveness of both individual companies and the economy as a whole. For the purposes of this thesis I have analysed the six greenhouse gases that are regulated by the Kyoto Protocol: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). The range of exercises that I put into practice in this thesis enables us to examine the usefulness of the models applied, and allow to analyse questions that are of great importance for the future environmental and economic conditions of Catalan society.

The chapter one contains a brief introduction to computable general equilibrium models, describing the different phases that make up the construction of any applied general equilibrium model, and the advantages and limitations of this type of models. I also give an introduction to the subject of computable general equilibrium models applied to the environment. In the chapter two I construct a social and environmental accounting matrix for Catalonia in the year 2001 (referred to below as NAMEACAT01), which will be used as the numerical basis for all subsequent analyses. A NAMEA (National Accounting Matrix using Environmental Accounts) is simply a double-entry table in which the rows contain the origins of the economic resources and the columns show the uses that economic agents give to the resources concerned.

In the next chapter, I define a linear model of emission multipliers using the NAMEA for the Catalan economy. Like income multipliers, emission multipliers can be divided into own effects, open effects and circular effects. This decomposition shows the various channels of income generation and how they affect regional greenhouse pollution.

The chapter four I analyses the economic impact of alternative policies implemented on the energy activities of the Catalan production system. Specifically, I analyse the effects of a tax on intermediate energy uses, a reduction in intermediate energy demand, and a tax on intermediate uses combined with a reduction in intermediate energy demand. The methodology involves two versions of the input-output price model: a competitive price formulation and a mark-up price formulation.

In chapter five, I use the model proposed by Roland-Holst and Sancho (1995) to assess the economic and social impact of the implementation of different policies to reduce CO2 emissions and improve, at the same time, the environmental competitiveness of enterprises and the private real income in Catalonia. Alternativelly, I also apply a second model, which is an extension of the exogenous determination of production in the input-output quantity model (Miller and Blair, 1985) to a SAM database. Finally, chapter six summarises the conclusions and future research of this study.
La presente tesis doctoral tiene como objetivo efectuar una aplicación de los diferentes modelos multisectoriales, para analizar el impacto que tendría en la economía y la sociedad catalana la implementación de diferentes políticas que nos permitiesen disminuir las emisiones de gases de efecto invernadero y obtener ahorros de energía y al mismo tiempo mejorar la competitividad de nuestras empresas y de nuestra economía. Concretamente para la realización de la presente tesis, hemos utilizamos los seis gases de efecto invernadero regulados por el protocolo de Kyoto: dióxido de carbono (CO2), metano (CH4), oxido nitroso (N2O), hexafluoruro de azufre (SF6), hirofluricarbonos (HFCs) y perflurocarbonos (PFCs). El conjunto de ejercicios que llevamos a cabo en esta tesis permite observar la utilidad de estas aplicaciones, abordando cuestiones de un importante interés para la realidad medioambiental y económica de la sociedad catalana.

El control neuromuscular ha estat descrit com un important factor per a l'èxit en el rendiment esportiu. De la mateixa manera, també s'ha identificat com a clau en la prevenció i readaptació de les lesions esportives. El principal objectiu d'aquesta tesi doctoral és avaluar l'eficàcia de diferents tipus d'entrenament neuromuscular en esportistes.
S'ha utilitzat una mostra de 81 esportistes sans entre els diferents estudis que s'hi presenten. Les diferents avaluacions realitzades han registrat els següents ítems: dolor (escala visual analògica), incidència de lesions esportives, estabilitat postural estàtica i dinàmica (estabilometria i salt unipodal) i força explosiva de l'extremitat inferior (salt amb contramoviment). Els dos mètodes d'entrenament neuromuscular utilitzats són l'anomenat TRAL (Teràpia Reequilibradora de l'Aparell Locomotor) i les VCS (vibracions de cos sencer).
La primera part d'aquesta tesi (Estudis I i II) va tenir l'objectiu de valorar l'eficàcia del mètode TRAL. Aquest va produir una reducció significant del dolor de turmell independentment del gènere registrat, mentre que en el cas del dolor de genoll només hi van haver diferències en les noies estudiades. Un dels altres efectes registrats importants a destacar va ser la reducció significant de l'àrea de desviació del centre de pressions en el cas de les noies, el que representa una millora de l'estabilitat postural. Aquesta dada també va ser positiva en una de les proves registrades en el grup de nois.
La segona part d'aquest treball (Estudi III) es va centrar en donar fiabilitat a una bateria de tests d'equilibri mesurats amb un estabilòmetre, tenint com a objectiu valorar l'estabilitat estàtica i dinàmica de l'extremitat inferior. Es va obtenir una correlació de bona a excel·lent en totes les variables de la millor amplitud promig en el test unipodal d'ulls oberts i tancats. Aquests resultats suggereixen una bona fiabilitat per a la distinció entre grups de subjectes. En el cas del test més dinàmic i proper a la realitat de l'esportista, el salt unipodal, la correlació va ser baixa.
Com a continuació d'aquesta segona part, l'estudi IV va comparar de forma transversal les diferències de l'estabilitat postural estàtica i dinàmica segons sexe i cama dominant. El test d'equilibri unipodal d'ulls oberts no va mostrar diferències significatives en la desviació del centre de pressions entre homes i dones. D'altra banda, el sexe femení va mostrar un major equilibri en els tests més dinàmics (UT i S) en comparació amb el sexe masculí. En relació a les diferències entre cama dominant - no dominant, només es van trobar diferències significatives en les dones en la recepció del salt unipodal, mostrant-se un millor control quan la recepció s'efectuava amb la cama dominant.
La següent línia de treball es va iniciar amb l'estudi V, que va consistir en una revisió sistemàtica sobre els efectes de l'entrenament vibratori sobre el rendiment esportiu en persones físicament actives. Els resultats van mostrar una gran heterogeneïtat clínica i una baixa qualitat metodològica dels treballs analitzats fins la data cercada. Malgrat no poder extreure conclusions clares, existeix una tendència a la millora de la força explosiva. També podem establir un rang segur dels paràmetres d'aplicació de vibracions mecàniques sobre la població d'estudi. Aquest es troba entre 1,7-11mm d'amplitud i entre 20-44 Hz de freqüència, aplicant-se tant en exercicis estàtics com dinàmics i fins a un màxim de 18 minuts de durada per sessió.
Per últim, es va realitzar un assaig clínic controlat aleatori (Estudi VI) amb l'objectiu de valorar l'eficàcia de l'entrenament mitjançant vibracions de cos sencer sobre la força explosiva i el control postural en joves jugadores de bàsquet. Els resultats van mostrar un increment significatiu del salt amb contramoviment, del salt unipodal i de l'equilibri amb ulls tancats a les 8 i 15 setmanes d'entrenament en el grup experimental. És destacable el fet que no es trobessin diferències significatives entre els tests realitzats a les 8 i les 15 setmanes d'entrenament en cap de les variables. D'altra banda, el grup control no va experimentar canvis respecte les valoracions preintervenció. Amb aquests resultats podem afirmar que l'entrenament vibratori possibilita la millora dels paràmetres analitzats, repercutint favorablement en el rendiment esportiu i, també, de forma indirecta, en la prevenció de lesions en esportistes d'alt risc.
A forma de síntesi, els estudis d'aquesta tesi emfatitzen la importància del control neuromuscular sobre el rendiment i prevenció de lesions esportives. És necessari destacar la importància de continuar investigant sobre noves eines que mesurin els paràmetres associats al control neuromuscular, així com seguir estudiant l'eficàcia dels diferents mètodes d'entrenament neuromuscular per a la seva optimització.
El control neuromuscular ha sido descrito como un importante factor para el éxito en el rendimiento deportivo. Del mismo modo, también se ha identificado como clave en la prevención y readaptación de las lesiones deportivas. El principal objetivo de esta tesis doctoral ha sido evaluar la eficacia de diferentes tipos de entrenamiento neuromuscular en deportistas.
Se ha utilizado una muestra de 81 deportistas sanos entre los diferentes estudios que se presentan. Las diferentes evaluaciones realizadas han registrado los siguientes ítems: dolor (escala visual analógica), incidencia de lesiones deportivas, estabilidad postural estática y dinámica (estabilometría y salto unipodal) y fuerza explosiva de la extremidad inferior (salto con contramovimiento). Los métodos de entrenamiento neuromuscular utilizados fueron el llamado TRAL (Terapia reequilibradora del Aparato Locomotor) y las VCE (vibraciones de cuerpo entero).
La primera parte de esta tesis (Estudios I y II) tuvo el objetivo de valorar la eficacia del método TRAL. Este produjo una reducción significativa del dolor de tobillo independientemente del género registrado, mientras que en el caso del dolor de rodilla sólo hubo diferencias en las chicas estudiadas. Otro de los efectos registrados importantes a destacar fue la reducción significativa del área de desviación del centro de presiones en el caso de las chicas, lo que representa una mejora de la estabilidad postural. Este dato también fue positivo en una de las pruebas de equilibrio registradas en el grupo de chicos.
La segunda parte de este trabajo (Estudio III) se centró en dar fiabilidad a una batería de tests de equilibrio medidos con un estabilómetro, teniendo como objetivo valorar la estabilidad estática y dinámica de la extremidad inferior. Se obtuvo una correlación de buena a excelente en todas las variables de la mejor amplitud media en el test unipodal de ojos abiertos y cerrados. Estos resultados sugieren una buena fiabilidad para la distinción entre grupos de sujetos. En el caso del test más dinámico y cercano a la realidad del deportista, el salto unipodal, la correlación fue baja.
Como continuación de esta segunda parte, el estudio IV comparó de forma transversal las diferencias de la estabilidad postural estática y dinámica según sexo y pierna dominante. El test de equilibrio unipodal de ojos abiertos no mostró diferencias significativas en la desviación del centro de presiones entre hombres y mujeres. Por otro lado, el sexo femenino mostró un mayor equilibrio en los tests más dinámicos (UT y S) en comparación con el sexo masculino. En relación a las diferencias entre pierna dominante - no dominante, sólo se encontraron diferencias significativas en las mujeres en la recepción del salto unipodal, mostrándose un mejor control cuando la recepción se efectuaba con la pierna dominante.
La siguiente línea de trabajo se inició con el estudio V, que consistió en una revisión sistemática sobre los efectos del entrenamiento vibratorio sobre el rendimiento deportivo en personas físicamente activas. Los resultados mostraron una gran heterogeneidad clínica y una baja calidad metodológica de los trabajos analizados hasta la fecha buscada. A pesar de no poder extraer conclusiones claras, existe una tendencia a la mejora de la fuerza explosiva. También podemos establecer un rango seguro de los parámetros de aplicación de vibraciones mecánicas sobre la población de estudio. Este se encuentra entre 1,7-11mm de amplitud y entre 20-44 Hz de frecuencia, aplicándose tanto en ejercicios estáticos como dinámicos y hasta un máximo de 18 minutos de duración.
Por último, se realizó un ensayo clínico controlado aleatorio (Estudio VI) con el objetivo de valorar la eficacia del entrenamiento mediante vibraciones de cuerpo entero sobre la fuerza explosiva y el control postural en jóvenes jugadoras de baloncesto. Los resultados mostraron un incremento significativo del salto con contramovimiento, del salto unipodal y del equilibrio con ojos cerrados a las 8 y 15 semanas de entrenamiento en el grupo experimental. Es destacable el hecho de que no se encontraran diferencias significativas entre los tests realizados a las 8 y las 15 semanas de entrenamiento en ninguna de las variables. Por otra parte, el grupo control no experimentó cambios respecto a las valoraciones preintervención. Con estos resultados podemos afirmar que el entrenamiento vibratorio posibilita la mejora de los parámetros analizados, repercutiendo favorablemente en el rendimiento deportivo y, también, de forma indirecta, en la prevención de lesiones en deportistas de alto riesgo.
En forma de síntesis, los estudios de esta tesis enfatizan la importancia del control neuromuscular sobre el rendimiento y prevención de lesiones deportivas. Es necesario destacar la importancia de continuar investigando sobre nuevas herramientas que midan los parámetros asociados al control neuromuscular, así como seguir estudiando la eficacia de los diferentes métodos de entrenamiento neuromuscular para su optimización.
Neuromuscular control is believed to be an important factor for success in athletic performance. Similarly, it has also been identified as a key to prevention and rehabilitation of sports injuries. The main objective of this thesis is to evaluate the effectiveness of different types of neuromuscular training in athletes.
A total of 81 healthy athletes were used for the purpose of the study. The evaluations performed have resulted in the following items: pain (visual analogue scale), incidence of sports injuries, static and dynamic postural stability (stabilometry and one-leg hop test) and explosive strength of the lower extremity (countermovement jump). Neuromuscular training methods used were TRAL (Locomotive rebalancing therapy) and WBV (whole body vibration).
The first part of this thesis (Studies I and II) aims to assess the efficacy of TRAL. The training period showed a significant reduction of ankle pain recorded regardless of gender, whereas in the case of knee pain only differences in the girls studied were found. Another important effect to highlight that contributes to an improvement of stability in body position in women is the significant reduction of movements of the centre of pressure, while there was only a significant reduction in one of the men tests.
The aim in the second part (Study III) is to assess the static and dynamic stability of the lower extremities focusing on battery of tests reliability measured with a stabilometer. Correlation obtained in single leg stance test of open and closed eyes was found in the range between good to excellent, in all variables of t he best average amplitude. These results suggest a good reliability for the distinction between subject groups. Regarding a more dynamic and closer to athlete's reality test, the one-leg hop test, poor correlation was obtained.
Continuing in the second part, study IV compares differences between static and dynamic position stability, by sex and leg dominance. The one leg stance with open eyes test showed no significant difference in the deviation of center of pressure between men and women. Moreover, females showed more balance in higher dynamics tests (UT and S) compared with males. The differences regarding dominant - non dominant leg, were found only in girls in receiving one leg jump, showing a better control where the reception took place with the dominant leg.
The next topic begins with study V, which consists of a systematic review on the effects of vibration training in physically active people. The results demonstrate a high clinical --heterogeneity and low methodological quality of previous studies performed prior to the date of our study. Even if we cannot provide a specific result, there is a tendency to improve explosive strength. Also, we can certainly establish a safe range of parameters for vibration training to be applied on a physically active population. This range goes from 1.7-11mm amplitude, 20-44 Hz frequency, both in static and dynamic exercises, and up to 18 minutes working with vibration.
In the last topic, we conduct a randomized controlled trial (Study VI) aimed to assess the effectiveness of whole body vibration training on explosive strength and postural control in young basketball players. The results showed a significant increase in countermovement jump, one-leg hop test and balance with closed eyes at 8 and 15 weeks of training with the experimental group. It is noteworthy that no significant differences were found between tests performed at 8 and 15 weeks of training in any of the variables. Moreover, the control group experienced no changes from pre-intervention assessments. Based on these results we can state that vibration training enables the improvement of the analyzed parameters, impacting positively on athletic performance, and indirectly prevents injuries in high-risk athletes.
In conclusion, this thesis emphasizes the importance of neuromuscular control on sports performance and prevention of injuries. It is necessary to stress the importance of continuing the research on new tools to measure parameters associated with neuromuscular control, and further studying the effectiveness of different methods of neuromuscular training for its optimization.

The existence of transportation costs gives labor markets a local dimension. In particular, the well-documented existence of agglomeration economies creates a positive correlation between a city's size and the productivity of the workers living there. The thesis explores the implications of this stylized fact on local unemployment rates as well as local labor market flows. First, based on the logic of a standard search and matching model of the labor market, I show that one would expect job finding rates to be increasing in city size, job separation rates to be decreasing in city size and, thus, unemployment rates to be decreasing in city size. Second, I show that, in fact, both job finding and separation rates are decreasing in city size, leading to a zero-correlation between unemployment rates and city size. Finally, I develop three theoretical models that attempt to rationalize these stylized facts within the framework of a local labor market governed by a constant-returns-to-scale matching function.
La presència de costos de transport fa que els mercats laborals tinguin una dimensió local. Concretament, l'existència d'economies d'aglomeració fa que hi hagi una correlació positiva entre la mida d'una ciutat i la productivitat dels treballadors que hi viuen. La tesi explora les implicacions d'aquest fet estilitzat sobre les taxes d'atur urbanes i sobre els fluxes del mercat laboral. En primer lloc, a partir de la lògica d'un model estàndard d'aparellament al mercat laboral, es demostra que caldria esperar que la probabilitat de trobar una feina augmenti amb la mida de la ciutat, que la probabilitat de perdre una feina disminueixi amb la mida de la ciutat i que, per tant, la taxa d'atur sigui menor en ciutats més grans. En segon lloc, es mostra que, segons les dades, tant la probabilitat de trobar una feina com la de perdre-la disminueixen amb la mida de la ciutat, de tal manera que les taxes d'atur no estan correlacionades amb la mida de la ciutat. En darrer lloc, construeixo tres models que racionalitzen aquests fets estilitzats dins del marc d'un mercat laboral local governat per una funció d'aparellament amb retorns constants a escala.

Les persones adultes amb discapacitat intel•lectual (DI) presenten baixos nivells de capacitat cardiovascular i força, al mateix temps que realitzen poca activitat física (AF) i freqüentment presenten problemes funcionals i d’equilibri. Un dels propòsits d’aquesta tesi fou investigar la fiabilitat del salt vertical en adults amb DI sobre una plataforma de contacte comparar-lo amb el test de salt de longitud sense impuls, normalment utilitzat en la bateria EUROFIT Special, per a avaluar la potència de les cames. Un altre objectiu fou avaluar els efectes d’un programa d’AF combinat incloent-hi exercicis aeròbics, de força i d’equilibri sobre la condició física la força, l’equilibri i les mesures funcionals en un estudi controlat. També s’han avaluat les característiques i nivells d’AF en el grup d’adults amb DI que va participar a la intervenció (GI) en comparació a un grup control (GC). Els participants, adults amb DI lleugera i moderada, varen ser assignats a un grup d’intervenció (GI; n = 37) i a un altre grup control (GC; n = 29). El GI va entrenar 3 vegades a la setmana, en sessions d’una hora durant 14 setmanes, mentre que el GC no va participar de cap tipus de programa d’AF. La resistència aeròbica, força, equilibri, flexibilitat i habilitats funcionals varen ser avaluades pre y post entrenament en ambdós grups. Com a resultat, el GI va millorar la seva capacitat aeròbica (26.8 vs. 29.3 ml•Kg-1•min-1), la força de prensió manual (19.2 vs. 21.9 kg), la força de cames i l’equilibri després del període d’entrenament (p < .05). El pes corporal (70.1 vs. 68.1 kg) i l’índex de massa corporal /27.4 vs. 26.6 kg•m-2) també varen disminuir (p < .05) en el GI. El GC no va presentar canvis en aquests paràmetres. Així també, els adults amb DI del GC varen realitzar menors quantitats d’AF moderada i vigorosa (AFMV) que el GI. Però és de senyalar que el comportament sedentari en ambdós grups fou elevat (~79% del temps monitoritzat). El 69.40% y el 32.10% dels participants del GI i GC respectivament varen complir amb les recomanacions de fer ≥150 minuts d’AFMV/setmana. Aquests resultats suggereixen que un programa d’AF aeròbic, de força i equilibri és beneficiós per a adults amb DI. Les intervencions per a disminuir el temps utilitzat en activitats sedentàries i augmentar l’AFMV haurien de formar part de l’horari laboral d’aquestes persones.
Las personas adultas con discapacidad intelectual (DI) presentan bajos niveles de capacidad cardiovascular y fuerza, al mismo tiempo que realizan poca actividad física (AF) y frecuentemente presentan problemas funcionales y de equilibrio. Uno de los propósitos de esta tesis fue investigar la fiabilidad del salto vertical en perdonas con DI sobre una plataforma de contacto y compararlo con el test de salto en largo sin impulso, normalmente utilizado en la batería EUROFIT Special, para evaluar la potencia de las piernas. Otro de los objetivos del estudio fue evaluar los efectos de un programa de AF combinado incluyendo ejercicios aeróbicos, de fuerza y de equilibrio sobre la condición física, la fuerza, el equilibrio y medidas funcionales en un estudio controlado. También se evaluaron las características y niveles de AF en el grupo de adultos con DI que participó en la intervención (GI) en comparación con un grupo control (GC). Los participantes, adultos con DI leve a moderada, fueron asignados a un grupo intervención (GI; n = 37) y otro grupo control (GC; n = 29). El GI entrenó 3 veces por semana, 1 hora durante 14 semanas, mientras que el GC no participó en ningún tipo de programa de AF. La resistencia aeróbica, fuerza, equilibrio, flexibilidad y habilidades funcionales fueron evaluadas pre y post entrenamiento en ambos grupos. Como resultado, el GI mejoró su capacidad aeróbica (26.8 vs. 29.3 ml•Kg-1•min-1), la fuerza de prensión manual (19.2 vs. 21.9 kg), la fuerza de piernas y el equilibrio luego del período de entrenamiento (p < .05). El peso corporal (70.1 vs. 68.1 kg) y el índice de masa corporal /27.4 vs. 26.6 kg•m-2) también disminuyeron (p < .05) en el GI. El GC no presentó cambios en estos parámetros. Así también, los adultos con DI del GC realizaron menores cantidades de AF moderada a vigorosa (AFMV) que el GI. Sin embargo, el comportamiento sedentario en ambos grupos fue elevado (~79% del tiempo monitorizado). El 69.40% y el 32.10% de los participantes del GI y GC respectivamente cumplieron con las recomendaciones de realizar ≥150 minutos de AFMV/semana. Estos resultados sugieren que un programa de AF aeróbico, de fuerza y equilibrio es beneficioso para los adultos con DI. Las intervenciones para disminuir el tiempo empleado en actividades sedentarias y aumentar la AFMV deberían formar parte del horario laboral de estas personas.
Adults with ID have decreased cardiovascular fitness and strength with lower rates of PA, and often have balance and functional impairments. One of the purposes of this study was to investigate the test-retest reliability of the vertical jump test on a contact platform and compare it with the standing long jump test, normally used in the EUROFIT Special battery, to assess leg power. Other aim of the study was to assess the effects of a combined PA program (CPAP) involving aerobic, strength and balance training on cardiovascular fitness, strength, balance and functional measures in a controlled clinical trial. It was also of interest to know and describe the PA patterns of these groups of adults with ID that participated in the CPAP in comparison to a CG. Adults with mild to moderate ID were randomized into either the intervention group (IG; n = 37) or the control group (CG; n = 29). The IG trained 3 d/wk, 1 h/d over 14 wks, while the CG did not participate in any exercise program. Cardiovascular fitness, strength, balance, flexibility and functional ability were assessed pre-post training. The IG increased cardiovascular fitness, (26.8 vs. 29.3 ml•Kg-1•min-1), handgrip strength (19.2 vs. 21.9 kg), leg strength, and balance following the training period (p < .05). Body weight (70.1 vs. 68.1 kg) and body mass index (27.4 vs. 26.6 kg•m-2) decreased (p < .05) in the IG group. The CG showed no changes in any parameter. Adults with ID in the CG were performing less MVPA than the IG. Nevertheless, important sedentary behaviors were observed in both groups (~79% of their monitoring time). In the IG a 69.4% of participants and a 32.1% in the CG met the PA of recommendations of ≥150 minutes of MVPA/week. These data suggest that a combined aerobic, strength and balance exercise training program is beneficial among individuals with ID. Interventions to decrease sedentary time and increase PA levels should be included into their work days.

Orientador: Maria da Consolação Gomes Cunha Fernandes Tavares
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica
Made available in DSpace on 2018-08-09T20:01:30Z (GMT). No. of bitstreams: 1 Oliveira_Gersonde_M.pdf: 760082 bytes, checksum: dab5c94436ffceaa7a041492624c8a98 (MD5) Previous issue date: 2007
Resumo: As práticas do Yoga são caracterizadas pela permanência numa condição de controle e conforto, onde não se estipula um padrão de execução e metas de desempenho motor. A esclerose múltipla é uma doença crônica desmielinizante que resulta de reações inflamatórias desencadeadas por mecanismos complexos de anormalidade imunorregulatória. É freqüente o acometimento do equilíbrio motor, podendo culminar na queda. Existe uma carência de estudos com relação à influência do Yoga no controle do equilíbrio de pessoas com esclerose múltipla. O objetivo desta pesquisa é avaliar a influência de um programa de Yoga no equilíbrio postural de pessoas com esclerose múltipla. Trata-se de uma pesquisa experimental com N=12 (doze), formado por pessoas com esclerose múltipla pertencentes ao Grupo de Esclerose Múltipla de Campinas e que nunca praticaram Yoga ou estão a pelos menos 01 ano sem praticar. O grupo experimental participou das práticas de Yoga uma vez por semana, com duração de 01 hora, durante o período de seis meses e o grupo controle não realizou as práticas. O equilíbrio foi avaliado através da Escala de Equilíbrio de Berg. Foi coletada também a percepção subjetiva do equilíbrio e o histórico de quedas através de questionário; essas avaliações e a avaliação da Escala de Incapacidade Funcional Ampliada (EDSS) foram realizadas no inicio e final do programa, quando foi oportunizado o programa de Yoga ao grupo controle. Constatou-se através da análise estatística dos resultados obtidos através da escala de Berg, que houve uma melhora significativa do equilíbrio postural dos sujeitos do grupo experimental em relação ao grupo controle, especialmente dos sujeitos com maior escore na EDSS. A percepção subjetiva retratou o que foi avaliado na escala de Berg
Abstract: The practice of Yoga is characterized by the remaining in a condition of control and comfort, where a standard and targets of performance are not specified. Multiple sclerosis is a chronic demyelinating disease that results of inflammatory reactions triggered by complex mechanisms of immunoregulatory abnormality. Balance is often involved and may culminate in a fall. There is a shortage of studies about the influence of Yoga in the control of the balance of people with multiple sclerosis. The objective of this research is to evaluate the influence of a program of Yoga in the postural balance of people with multiple sclerosis. This is an experimental research with N=12 (twelve), and with people with multiple sclerosis who belong to the Multiple Sclerosis Group of Campinas and who never practiced Yoga or who are at least 01 year without a practice. The research group practiced Yoga once a week with classes of 01 hour during a period of six months while the control group did not practice Yoga. The balance was evaluated by the Scale of Balance of Berg. The subjective perception of the balance and the data of falls were also evaluated by means of a questionnaire; such assessments and the evaluation of the Functional Disability Extended Scale (EDSS) were conducted at the beginning and at the end of the program when the program of Yoga was offered to the control group. A significant improvement in the postural balance of the subjects of the research group, especially those with higher EDSS score, was found by means of statistical analysis of the results obtained by the Berg Scale, when compared to the control group. The subjective perception represented the same that was evaluated on the Scale of Berg
Mestrado
Atividade Fisica, Adaptação e Saude
Mestre em Educação Física

El primer propòsit d'aquesta tesi doctoral era investigar la creativitat humana. Ben aviat, però, vam adonar-nos que per endinsar-nos en aquesta qüestió hi havia dues premisses bàsiques: (1) investigar la subjectivitat humana i (2) fer un treball interdisciplinar i de diàleg entre al filosofia, les ciències cognitives i els avenços en el terreny de la física del no equilibri. Finalment, doncs, en aquesta tesi hi trobareu una anàlisi sobre com cal veure la subjectivitat humana i, a partir d'ella, discernir sobre el caràcter d ela creativitat humana. Hem recercat les condicions de la creativitat humana cercant les característiques del que anomenem "subjectivitat" i del que anomenem "consciència".

En tot moment s'ha cercat fugir de tòpics, adequar les perspectives que es mostren a partir del diàleg interdisciplinar i dels avenços de els neurociències i de els ciències de la complexitat i contrastant el que històricament i des de la psicologia s'ha dit sobre la creativitat amb allò que han dit els artistes (compositors, pintors i literats) sobre la seva vivència de l'acte creatiu.
El camí a recórrer era llarg i incert i el camí que s'obre a partir de la tesi és complexe i ambiciós. De tot amanera, pensem que amb aquesta aportació podem obrir la possibilitat d'una tematització seriosa i argumentada sobre la creativitat humana a partir d'una integració de les aportacions de les diferents disciplines científiques i un replantejament de les nocions de "subjectivitat", de "consciència" i de "creativitat".
És per tot plegat que després del capítol d'introducció de les temàtiques que tractarem, hi ha un primer capítol dedicat al cervell i a la consciència, un segon capítol dedicat als conceptes de "creació" i de "creativitat" (en la natura i en al cultura), un tercer capítol dedicat a la creació artística a partir del que s'ha vist en els dos capítols anteriors, un capítol dedicat a fer síntesi dels tres anteriors per veure la consistència i coherència de les nostres hipòtesis de sortida; i una darrera part que consta de tres apèndix (els apèndix 1 i 2 serveixen per reflexionar sobre com obrir noves vies d'investigació, i l'apèndix 3 serveix per fer reconeixement del biòleg i filòsof Ramon Turró com a referent important de la investigació de la persona humana a Catalunya i a Europa).
The first purpose of this doctoral thesis was to investigate human creativity. Soon, we realized that there were two basic premises to get into this question: (1) to investigate human subjectivity and (2) to make an interdisiplinary work and a dialogue bearing in mind, philosophy, cognitive sciences and the advances in the field of the science of non- balance. Finally, in the thesis, you will find an analyses on how to look at human subjectivity and from it to distinguish the character of human creativity. We have looked in the conditions of human creativity searching for the characteristics of what we call subjectivity and what we call "consciousness".

In all the work, we have tried to run away from clichès and to adapt the perspectives from the interdisiplinary dialogue in the advances of neuroscience and the sciences of complexity, contrasting them with what from a historical perspective and from psychology view has been told about creativity and what the artists themselves have said about their experience of their creative act.

We had ahead a long and uncertain paht and the way the the thesis is opened is complex and ambitious. However, we believe that with this contribution we may open the possibility to have a serious and argued view on human creativity integrating the contributions made from different scientific disiplines and establishing new concepts on "subjectivity", "conciousness" and "creativity".

Bearing all this in mind, after the introduction chapter, which introduces the main themes, we will deal, there is a first chapter devoted to brain and conciousness, a second chapter devoted to the concepts of creation and ceativity ( in nature and culture), a third chapter devoted to artistic creation from the point of view studied in the first two chapters, a chapter devoted to make a synthesis of the three former ones to see the consistency and coherence of the hypothesis made at the beginning; and the last part that it is formed by three appendix ( appendix one and two are used to think on how to open new ways to investigate, appendix three is an acknowledgement to the biologist and philosopher, Ramon Turró, as a referent investigating human being in Catalonia and in Europe.

Questa tesi studia un mercato assicurativo competitivo in cui gli assicurati possiedono informazione privata riguardo la loro rischiosità, e al contempo gli assicuratori, in ragione della loro superiore esperienza, hanno una maggiore abilità a valutare il rischio. Nel caso in cui il rischio sia perfettamente stimabile dagli assicuratori e tale stima rappresenti la loro informazione privata, una perfetta rivelazione dell'informazione può non avvenire ed equilibri profittevoli sono possibili, nonostante il contesto competitivo. Inoltre, l'aumento della pressione competitiva può rivelarsi inefficace ai fini di una riduzione dei prezzi assicurativi, in quanto può semplicemente comportare una riduzione dei profitti dei singoli assicuratori. Tuttavia, Il vantaggio informativo degli assicuratori può permettere soluzioni caratterizzate da una maggiore efficienza. La presenza di doppia asimmetria informativa permette anche di spiegare l'esistenza di una correlazione negativa tra rischio e copertura assicurativa in mercati competitivi. Inoltre, se la stima del rischio da parte degli assicuratori è affetta da incertezza, così che gli assicuratori differiscono gli uni dagli altri per quanto riguarda la stima del rischio, profitti nulli non sono consentiti.
This dissertation studies a competitive insurance market in which a policyholder owns private information about her own riskiness and at the same time insurers (through their higher expertise) are better able to estimate it. If insurers’ estimations are private and identical, we find that, despite the presence of competition, perfect revelation of information is not necessarily achieved and profitable outcomes are possible. Adding competitive pressure may be ineffective in driving the insurance prices downward, as it simply reduces the individual insurer’s profits. The insurers’ informative advantage, however, allows more efficient outcomes. The presence of a bilateral asymmetry can also explain why, in dispersed markets, low risk policyholders may be more insured than high risk ones. Moreover, if insurers’ private estimations are heterogeneous and suffer of some degree of uncertainty, we find that, in addition to the previous results, actuarially fair outcomes for all policyholders are never allowed, despite the presence of competition.

Orientador: Maria Filomena Ceolim
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação
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Mestrado
Mestre em Gerontologia

Orientador: Adalberto Bono Maurizio Sacci Bassi
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: A termodinâmica clássica é utilizada, por muitos professores e autores, exclusivamente como um instrumento para a solução de problemas. Por isto, não costuma ser feita uma discussão aprofundada sobre seus conceitos, sobre suas equações matemáticas, ou sobre a limitação teórica da termodinâmica. Este trabalho é realizado dentro deste contexto. O intuito do trabalho é o de analisar e comparar livros didáticos de termodinâmica clássica, na definição dos conceitos e no tratamento matemático utilizado. Verificar se existe uma única termodinâmica clássica, ou se as idéias mais fundamentais apresentadas dependem fortemente do enfoque do autor, ou do que este quer mostrar. Foram escolhidos sete livros didáticos bem conhecidos (Atkins, Callen, Guggenheim, Levine, McQuarrie et al., Moran et al. e Sonntag et al.) e, além destes autores, outros também foram utilizados, mas de forma mais específica. Supondo-se que os autores mantenham coerência interna nos seus respectivos livros, eventuais incoerências entre os autores, em conceitos derivados dos alicerces da termodinâmica, seriam apenas necessárias conseqüências de incoerências mais fundamentais. Por isto, não se considera que restringir a comparação aos conceitos fundamentais implique numa perda de abrangência, em relação aos objetivos antes colocados. O trabalho está dividido em seis seções, cada uma delas subdividida em três partes: colocações feitas por cada um dos sete autores; comparação entre os autores; e eventual apresentação de conceitos preferidos por outros autores. Há, ainda, a conclusão, que contém uma discussão mais aprofundada sobre alguns tópicos específicos e a introdução
Abstract: Classical thermodynamics is used, by many professors and authors, exclusively as an instrument for solving problems. Because of that, concepts, mathematical foundations and even thermodynamics limitations as a theorethical model aren¿t often discussed. This piece develops within this context. The aim of this paper is to analyze and compare classical thermodynamics textbooks in regard to concepts presented and mathematical models applied. Also, to verify if there is a consensual classical thermodynamics or if the ideas presented vary among the authors. Seven well-known pieces were chosen (Atkins, Callen, Guggenheim, Levine, McQuarrie et al., Moran et al. e Sonntag et al.) and, on top of these textbooks, others were used specifically. Supposing the authors are coherent within their own writings, inconsistencies that might be found among the authors could be the consequence of divergencies regarding the basis of thermodynamics. Consequently, narrowing down the analysis exclusively to basic concepts is not considered superficial. The work is divided into six sections, each one with three parts: presentation of each author¿s concept; comparison among the authors; and eventually, concepts adopted by other authors. There is also a conclusion covering an in-deep discussion of some topics presented, as well as the introduction of the paper
Mestrado
Físico-Química
Mestre em Química

We consider the class of two-player symmetric n x n games with the total bandwagon property (TBP) introduced by Kandori and Rob (1998). We show that a game has TBP if and only if the game has 2^n - 1 symmetric Nash equilibria. We extend this result to bimatrix games by introducing the generalized TBP. This sheds light on the (wrong) conjecture of Quint and Shubik (1997) that any n x n bimatrix game has at most 2^n - 1 Nash equilibria. As for an equilibrium selection criterion, I show the existence of a ½-dominant equilibrium for two subclasses of games with TBP: (i) supermodular games; (ii) potential games. As an application, we consider the minimum-effort game, which does not satisfy TBP, but is a limit case of TBP. (author's abstract)
Series: Department of Economics Working Paper Series

El turmell és una articulació que registra un alt percentatge de lesions. Els individus afectats per lesions al turmell acostumen a mostrar alteracions de l’equilibri postural i de la capacitat de percebre l’articulació estable, cosa que fa augmentar el risc de patir de nou un esquinç al turmell, així com també s’han descrit alteracions en els patrons d’activació muscular de diferents grups musculars de la cama. Per aquest motiu s’han desenvolupat diferents protocols d’entrenament neuromotor orientats a disminuir el risc de patir una lesió al turmell, però malauradament fins avui, aquests han mostrat baixos nivells d’evidència i efectivitat. Aquesta tesi va tenir dos objectius principals: analitzar l’efectivitat d’un protocol d’entrenament neuromotor com a eina de prevenció sobre la millora de l’estabilitat dinàmica del turmell, i determinar la relació existent entre els nivells d’activació de la musculatura pèlvica i els de la musculatura estabilitzadora del turmell. Els resultats obtinguts en la realització dels estudis realitzats per aquesta tesi, indiquen que la realització d’un entrenament neuromotor tradicional orientat a la millora de l’estabilitat del turmell no va suposar un estímul suficient per obtenir millores en la capacitat d’equilibri de la mostra estudiada, i que la influència observada entre l’activació de la musculatura proximal de la cama i la pròpia del turmell, sembla indicar que la introducció d’exercicis d’entrenament específic de la musculatura estabilitzadora de la pelvis podria representar una eina interessant per la millora dels nivells d’estabilitat del turmell.
El tobillo es una articulación que sufre un alto porcentaje de lesiones. Los individuos afectados por alguna lesión en esta región suelen mostrar alteraciones del equilibrio postural y de la capacidad de percibir la articulación estable, lo que aumenta el riesgo de sufrir de nuevo un esguince en el tobillo, así como se han descrito alteraciones en los patrones de activación muscular de distintos grupos musculares de la pierna. Por este motivo se han desarrollado diferentes protocolos de entrenamiento neuromotor orientados a disminuir el riesgo de sufrir una lesión en el tobillo, pero desafortunadamente hasta nuestro tiempo, han mostrado bajos niveles de evidencia y efectividad. Por estos motivos esta tesis tuvo dos objetivos principales: analizar la efectividad de un protocolo de entrenamiento neuromotor como herramienta de prevención sobre la mejora de la estabilidad dinámica del tobillo, y determinar la relación existente entre los niveles de activación de la musculatura pélvica y los de la musculatura propia del tobillo. Los resultados obtenidos en la realización de los estudios realizados para esta tesis, podemos concluir que la realización de un entrenamiento neuromotor tradicional orientado a la mejora de la estabilidad del tobillo no supuso un estímulo suficiente para obtener mejoras en la capacidad de equilibrio de la muestra estudiada, y que la influencia observada entre la activación de la musculatura proximal de la pierna y la propia del tobillo, parece indicar que la introducción de ejercicios de entrenamiento específico de la musculatura estabilizadora de la pelvis podría representar una herramienta interesante para la mejora de los niveles de estabilidad del tobillo.
The ankle is a joint that undergoes a high percentage of injuries. People who have suffered from an injury can show some kind of imbalance according to postural balance and related to the ability to perceive joint stability, which increases the risk of suffering an injurie again. In addition, changes have been described in muscle activation patterns for those who have suffered an injury in this joint. All this data has led physiotherapists to design different neuromotor training programs to reduce the risk of injuring the ankle again. Unfortunately until now, there is very little scientific evidence about their effectiveness. For these reasons, this thesis had two main objectives: first, to analyse the effectiveness of a neuromotor training program as a prevention mechanism for improving the dynamic stability of the ankle, and second, to determine the relationship between the electromyographic activity of the hip muscles and the ankle muscles. Based on the results obtained in this thesis, we can conclude that the performance of a traditional neuromotor training program, with the aim of improving ankle stability, does not represent a sufficient stimulus to generate balance improvements in the sample studied. The influence observed between the proximal muscle activity and the ankle muscle activity, seems to show that it is necessary to introduce specific training based on the hip muscles, and this could represent an interesting tool for improving ankle stability.

Orientador: Reginaldo Guirardello
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: A demanda mundial por energia cresce a cada ano. Essa demanda pode atingir níveis que os recursos atuais de combustíveis fósseis não podem sustentar. Neste contexto, os biocombustíveis surgem como uma fonte crescente de energia primária, aumentando a oportunidade de pesquisa e desenvolvimento de tecnologia a níveis animadores. Uma importante questão relacionada com o desenvolvimento destes biocombustíveis é o equilíbrio de fases entre seus componentes. Este trabalho investiga o equilíbrio líquido-vapor (ELV) de sistemas binários e o equilíbrio líquido-líquido (ELL) de sistemas ternários e quaternários, além do equilíbrio líquido-líquido-vapor (ELLV) de sistemas ternários, compostos por óleo vegetal, álcool, glicerina e éster, envolvidos na produção do biodiesel. O modelo desenvolvido também é capaz de predizer o equilíbrio químico e de fases para vários tipos de óleos vegetais na produção de biodiesel. Para tanto houve a necessidade da estimativa das propriedades físicas destes vários componentes e uma busca por métodos de predição através de contribuição de grupos foi realizada para as propriedades físicas não encontradas na literatura. A minimização da energia de Gibbs foi utilizada para calcular cada fase presente em uma determinada condição de pressão e temperatura, assim como a composição de cada fase prevista. A equação de estado de Soave-Redlich-Kwong (SRK-EOS) com a regra de mistura de van der Waals de dois parâmetros ajustáveis (VdW-2) foi empregada. O software GAMS® 23.1.3 (General Algebraic System Model) combinado com o solver CPLEX foi utilizado para resolver numericamente o modelo matemático. Através de discretização das frações molares, a modelagem do problema pode ser desenvolvida na forma de uma programação linear. Os dados experimentais foram representados de forma satisfatória por estes modelos e utilizando SRK-EOS obteve-se desvio absoluto médio e tempo computacional para sistemas binários, ternários e quaternários respectivamente de 1,03%, 1,39% e 1,30% e 0,17s, 27s e 6s, para os sistemas utilizando metanol. Já para os sistemas que utilizam etanol, o desvio absoluto médio e tempo computacional para sistemas binários e ternários são respectivamente de 0,64% e 2,10% e 0,14s e 26s
Abstract: The worldwide energy demand increases every year. This demand will reach levels that cannot be supplied by current conventional fossil fuel resources. In this context, biofuels arise as a growing primary source of energy, raising research opportunities and encouraging technology development. An important technical issue related to biofuels development is the phase equilibrium among their components. This work investigates the vapor-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) of binary, ternary and quaternary systems composed by vegetable oil, alcohol, glycerol and ester, involved in biodiesel production. The Gibbs energy minimization was used to calculate the amount of each phase present in a particular condition of pressure and temperature, as well as the composition of each phase predicted. The Soave-Redlich-Kwong (SRK) equation of state with van der Waals mixing rule, with two adjustable parameters (vdW-2) was employed. The GAMS® 23.2.1 (General Algebraic Model System) in combination with the solver CPLEX was used to tackle the large and complex mathematical models. The minimization of the Gibbs energy was done using a discretized procedure, so that the problem could be solved as a linear programming approach. The proposed model is also used to predict the chemical and phase equilibrium for eight types of vegetable oils in biodiesel production. For this purpose it was necessary to estimate the physical properties of these various components and a search for methods of prediction by group contribution was made to physical properties not found in the literature. The experimental data were correlated quite well by the Soave-Redlich-Kwong (SRK) equation of state, with absolute medium deviations and computational time for binary, ternary and quaternary systems using methanol as a compound of: 0.83% and 0.17s, 1.39% and 27s and 1.30% and 6s, respectively. Using ethanol as a compound, the absolute medium deviations and computational time for binary and ternary systems of: 0,64%, 2,10% , 0,14s and 26s
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química

Orientador: Ibsen Bellini Coimbra
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação
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Resumo: O processamento do controle postural tem início com a comunicação entre o ambiente e corpo, feita por meio dos sistemas sensoriais. Com o envelhecimento, estes sistemas são afetados pela diminuição da reserva funcional e/ ou doenças, predispondo o idoso à instabilidade e quedas. Objetivo: Analisar a influência das informações sensoriais no equilíbrio estático de idosos, comparando-os, em grupos, quanto ao histórico de quedas (sem queda, uma queda e quedas recorrentes) no último ano. Método: Pesquisa descritiva comparativa de corte transversal. Amostra constituída por idosos da comunidade cadastrados em unidade de saúde da família, selecionados e divididos por grupos em consulta ao banco de dados de pesquisa populacional sobre envelhecimento no município de Amparo (SP). Cada grupo foi reduzido a 32 sujeitos por filtro de gênero e faixa etária. O protocolo de avaliação incluiu dados sociodemográficos, clínicofuncionais, psicocognitivos e de equilíbrio estático. O equilíbrio foi avaliado pelo CTSIB que analisa a capacidade de manutenção da estabilidade frente a seis condições de conflitos sensoriais. Foi realizada análise descritiva e inferencial dos dados por meio dos testes de Qui-quadrado, ANOVA, Teste-T e Correlação de Pearson; todos com nível de significância a 5%. Resultados: Houve maior número de casos anormais ao CTSIB para o Grupo de quedas recorrentes em relação ao Grupo sem quedas nas condições 4 (p=0,012) e 5 (p=0,017); e ao Grupo de uma queda na condição 4 (p=0,052). Quanto ao tempo despendido, o Grupo de quedas recorrentes permaneceu menos tempo do que o Grupo sem quedas nas condições 4 (p=0,043), 5 (p=0,042) e 6 (p=0,052). Na progressão do CTSIB, os Grupos sem quedas e uma queda apresentaram menor tempo despendido da condição 4 para a 5 (p=0,016 e p=0,012, respectivamente) e o Grupo de quedas recorrentes teve menor desempenho da condição 1 para a 2 (p=0,039) e da 4 para a 5 (p=0,001). A idade foi a variável de maior associação com a informação sensorial nos três grupos. Conclusão: Os resultados revelam que a interação sensorial nos idosos difere quanto ao histórico de quedas e que no Grupo de quedas recorrentes há maior dependência no sistema somatossensorial e visual. Com esses dados, é possível direcionar o processo de reabilitação e prevenção por meio do treinamento e/ou compensação das estratégias deficitárias e diminuição da dependência sensorial
Abstract: The processing of postural control starts with the environment and body communication, through sensorial systems. Because of the ageing, these systems are affected by the functional decrease and/or diseases, predisposing the elderly to instability and falls. Objective: This work is aimed at analyzing the influence of sensorial information in the elderly¿s static balance comparing them in groups, according to the report of falls (without fall, one fall and recurrent falls) in the last year. Method: A transversal descriptive comparative research. The sample was composed by community-dwelling elderly, which were registered in the Health Family Unit. They were selected and divided into groups by means of consultation of the database on a population research about aging in the Municipal District of Amparo (SP). Each group was reduced to 32 subjects by gender and age filter. The evaluation protocol included socialdemographic, health, physical, psychological and cognitive status, and static balance performance data. The balance was evaluated by CTSIB, which analyzes the stability maintenance capacity according to six sensorial conflicts conditions. The descriptive and inferential analysis was accomplished by means of the tests: Qui-squared, ANOVA, T-Test and Pearson Correlation; with significance level of 5%. Results: There was a larger number of CTSIB abnormal cases for the Group of recurrent falls in comparison to the Group without falls in the conditions 4 (p=0.012) and 5 (p=0.017); and to the Group of one fall in the condition 4 (p=0.052). As for the time performance, the Group of recurrent falls remained less time than the Group without falls in the conditions 4 (p=0.043), 5 (p=0.042) and 6 (p=0.052). In relation to the CTSIB progression, the Groups without falls, and one fall presented less time from the condition 4 to 5 (p=0.016 and p=0.012, respectively); and the Group of recurrent falls had a worse performance from the condition 1 to 2 (p=0.039) and from the condition 4 to 5 (p=0.001). The variable age was presented the largest association with the sensorial information for all the groups. Conclusion: The results showed that the sensorial interaction in the elderly varies according to the history of falling. They also revealed that there is a larger dependence on the visual and somatosensory systems for the Group of recurrent falls. In this way, it is possible to guide the rehabilitation process and prevention with training and/or compensation of deficient strategies and decrease the sensorial dependence
Mestrado
Mestre em Gerontologia

The aim of this thesis is to analyze and describe a mechanism of educational influence which research has identified in different instructional contexts. We study the mechanism of cession and transfer of learning control and responsibility from teacher to students in a teaching and learning sequence of dynamic balance in school physical education. The theoretical background of this work is based on the constructivist perspective and the cultural psychology. In a more specific level, we adopt the «constructivist conception of school teaching and learning» as a theoretical and methodological approach to the study of the educational school practices. From this view, it takes a lot of importance the concept of "interactive triangle" as the basic structure from which students build their knowledge. The content which constitutes one vertex of the interactive triangle is dynamic balance. For this reason we present dynamic balance as a school physical education content and different proposals and methodological basis to justify its work during these ages
L’objectiu principal de la tesi és analitzar i descriure un dels mecanismes d’influència educativa que la recerca ha identificat en diferents contextos instruccionals. Estudiem el mecanisme de cessió i traspàs del control i la responsabilitat de l’aprenentatge del professor als alumnes en una seqüència didàctica d’equilibri dinàmic en educació física escolar. Les bases teòriques que guien aquest treball es fonamenten en la perspectiva constructivista d’orientació sociocultural. Adoptem, a nivell més específic, la «concepció constructivista de l’ensenyament i l’aprenentatge escolar» com a enfocament teòric i metodològic per a l’estudi de les pràctiques educatives escolars. Des d’aquesta concepció, pren molta importància el concepte de “triangle interactiu” com l’estructura bàsica a partir de la qual els alumnes construeixen el seu coneixement. El contingut que constitueix un dels vèrtex del triangle interactiu és l’equilibri dinàmic. Per aquest motiu presentem l’equilibri dinàmic com a contingut en educació física escolar i diferents propostes i bases metodològiques que justifiquen el seu treball en aquestes edats

Orientador: Antonio Jose de Almeida Meirelles
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Doutorado
Engenharia de Alimentos
Doutor em Engenharia de Alimentos

Le compostage constitue un phénomène simple qui nécessite cependant un savoir-faire important puisque la réaction biologique est orientée par le contrôle de certains paramètres (température, oxygène, humidité) faisant intervenir de nombreux phénomènes couplés. Face à la complexité des mécanismes à étudier et dans le but d'optimiser le procédé industriel, l'utilisation d'un modèle de compostage semble donc pertinente afin de mieux comprendre les mécanismes mis en jeu, d'identifier les effets des couplages entre les mécanismes et mettre en avant certains facteurs clés ou encore comparer différents scénarios. L'état de l'art des modèles de compostage montre qu'aujourd'hui, malgré le nombre important de modèles de compostage, il n'en existe aucun capable de prédire, avec une formulation en temps et en espace, la température, la concentration des gaz (oxygène, dioxyde de carbone, diazote, …), la teneur en eau, les transferts entre phase, la dégradation du substrat, et prenant en compte les modifications d'aération. Le développement d'un nouveau modèle a donc été nécessaire pour pouvoir prédire l'évolution de ces variables et étudier leur couplage dans le procédé. Pour cela, la technique de moyenne volumique, appliquée aux équations à l'échelle du pore, a été utilisée et a permis d'obtenir un modèle de compostage à l'échelle de Darcy. Ce modèle prend en compte une phase gazeuse, une phase liquide et une phase solide. La phase gazeuse comprend quatre espèces : oxygène, dioxyde de carbone, azote, et vapeur d'eau. Dans la phase liquide, seule l'eau est considérée. Le séchage est intégré au modèle sous la forme d'un terme d'échange entre les phases gazeuse et liquide. Enfin, un modèle biologique, inclus dans le modèle de compostage, permet de prendre en compte la dégradation du substrat. Celui-ci est divisé en trois fractions : rapidement biodégradable, lentement biodégradable et inerte. Les deux premières fractions sont solubilisées, fournissant une fraction rapidement hydrolysable. Cette fraction est supposée directement consommée par les bactéries. En compostage, procédé aérobie, la dégradation de la matière organique est associée à une consommation d'oxygène et production de dioxyde de carbone, d'eau et de chaleur. L'hypothèse d'équilibre local thermique et chimique a été supposée ici. Cependant, pour l'eau, les 2 approches (Equilibre Local (EL) et Non-Equilibre Local (NEL)) ont été testées numériquement. Les résultats ont montré que lorsque σ, le coefficient d'échange de masse entre la phase gaz et la phase liquide pour l'eau, est compris dans l'intervalle [1, 4], les approches EL et NEL sont équivalentes, avec des temps de calcul moindres pour le cas NEL. Ainsi, pour toutes les simulations, une écriture NEL a été adoptée avec une valeur de σ de 2.5. Des tests ont ensuite permis de montrer la consistance du modèle. Au vu du nombre important de paramètres, une analyse de sensibilité a ensuite été réalisée afin de déterminer quels sont les paramètres qui ont l'impact le plus important sur le procédé. Ainsi, l'analyse a mis en évidence qu'il faut être prudent quant aux valeurs utilisées pour la capacité calorifique, un coefficient de l'isotherme de sorption, de nombreux paramètres du modèles biologiques (ksH, krH, µmax, Xa,0, Tmax, Topt, Xi,0, Xrb,0) et la porosité. Enfin, les résultats fournis par le modèle ont été comparés aux résultats expérimentaux obtenus à l'échelle pilote 1/1000 en usant des conditions opératoires identiques. Les essais de compostage réels ont été réalisés par Veolia Environnement Recherches et Innovation sur un mélange de biodéchets des ménages et de déchets verts
Composting may look like a simple process. However, it requires an important expertise, as the biological response is governed by the control parameters (temperature, oxygen, moisture content), involving many coupled phenomena. Given the complexity of the studied mechanisms and in order to optimize the process, using a composting model seems relevant to understand the mechanisms involved, identify the effects of coupling between these mechanisms, highlight some key factors or compare different scenarios, in order to optimize the industrial process. The state of the art of composting models in the literature shows that today, despite the large number of composting models, there is none that can predict, with a formulation in time and space, temperature, concentration of gases (oxygen, carbon dioxide, nitrogen, ...), moisture content, transfers between phases, degradation of the substrate, and take into account the changes in aeration. The development of a new model was therefore necessary to predict the evolution of these variables and study their coupling in the process. The technique of volume averaging applied to the pore scale equations has led to a composting model at the Darcy-scale. This model takes into account a gas phase, a liquid phase and a solid phase. The gas phase includes four species: oxygen, carbon dioxide, nitrogen and water vapor. In the liquid phase, only water is considered. Drying is integrated into the model as an exchange term between gas and liquid phases. Finally, the biological model, included in the composting model, allows to take into account the degradation of the substrate. It is divided into three fractions: readily hydrolysable, slowly hydrolysable and inert. The first two fractions are hydrolized, providing a readily assimilable soluble fraction. It is this fraction that is directly consumed by bacteria. In a composting process, degradation of organic matter is associated with oxygen consumption and production of carbon dioxyde, water and heat. The assumption of thermal and chemical local equilibrium was assumed in this work. However, for water, the two approaches (Local Equilibrium (LE) and Local Non-Equilibrium (LNE)) have been numerically tested. The results showed that when , the water mass exchange coefficient between gas and liquid phases, ranges from 1 to 4 s-1, the LE and LNE approaches are equivalent, with less computing time for the LNE case. Thus, for all future simulations, it was decided to adopt a LNE approach with a value of equal to 2.5 s-1. Tests were then carried out to show the consistency of the model. Given the large number of parameters, a sensitivity analysis was performed to determine the parameters that have the greatest impact on the process. This analysis showed that one must be cautious about the values used for the heat capacity, a coefficient of the sorption isotherm, many parameters from the biological model (ksH, krH, μmax, Xa,0, Tmax, Topt, Xi,0, Xrb,0) and porosity, because these are the parameters that affect mainly the process. Finally, the results provided by the model were compared with experimental results obtained at a pilot scale of 1/1000 using identical operating conditions. The composting experiments were carried out by Veolia Environment Research and Innovation with a mixture of household biowaste and green waste. The results on the 1/1000 scale pilot showed that the model is good at capturing the average change in temperature and concentration during the process. The temperature at the central point in particular is very well reproduced by the model. The same applies to the assessment of organic matter degradation. Simulations at industrial scale (1/1) have also been carried out. They have given promising results

La inmovilización funcional del tobillo es un recurso de fisioterapia que se utiliza para la prevención y el tratamiento de lesiones de ligamentos del tobillo, a través de dos técnicas, el Vendaje Funcional y la Ortesis de Tobillo. En el baloncesto se realizan movimientos del tobillo de gran amplitud articular, que podrían alterar las propiedades de un vendaje funcional y de una ortesis de tobillo. El estudio analiza y compara vendaje funcional y una ortesis de tobillo, en relación a su capacidad de limitación de la inversión y sus efectos sobre el equilibrio dinámico y sobre la funcionalidad en una sesión de ejercicio físico aplicada al baloncesto. Los participantes son jugadores de baloncesto federados con edades comprendidas entre 18 y 35 años, a los cuales se valoró ambos tobillos. El estudio se estructuró en dos etapas. En la Etapa 1 se analizó la fiabilidad de la tabla de inversión. Es un instrumento que se diseñó y se construyó para este estudio y permitió la medición del movimiento de la inversión de tobillo en cadena cinética cerrada. La Etapa 2, mediante un ensayo clínico cruzado, analizó la capacidad de limitación de inversión del tobillo de un vendaje funcional y de una ortesis de tobillo durante una sesión de ejercicio físico aplicada al baloncesto que tenía integrados test de medición articular, de equilibrio dinámico y de funcionalidad. Se midieron los efectos sobre el equilibrio dinámico del vendaje funcional y de la ortesis de tobillo al inicio y al final de la sesión, se midieron los efectos del vendaje funcional y de la ortesis de tobillo sobre la funcionalidad en extremidad inferior durante la sesión y se compararon las dos técnicas en relación a los parámetros obtenidos. A todos los participantes se les realizaron mediciones en tres condiciones, la primera sin inmovilización funcional de tobillo, la segunda con vendaje funcional y la tercera con ortesis. Los datos obtenidos en la Etapa 1 se trataron mediante el cálculo del Índice de Correlación Intraclase, para la determinación de la fiabilidad intraobservador y la fiabilidad interobservador. En la Etapa 2, con el fin de evaluar la evolución, se ajustó la variable respuesta con un modelo lineal generalizado (GLM). Posteriormente se comprobó la normalidad mediante el Test de Kolmogorov-Smirnov y la esfericidad mediante la Prueba de Esfericidad de Mauchly. Finalmente, con un análisis post-hoc con corrección de Bonferroni se determinó entre qué comparaciones se observaban diferencias estadísticamente significativas. En todos los modelos ajustados y test de contraste se utilizó un nivel de significación de α=0.05. Los resultados obtenidos permiten constatar que la tabla de inversión es un instrumento con una excelente fiabilidad intraobservador. El vendaje funcional tiene mayor capacidad de limitación del movimiento de inversión de tobillo que la ortesis. Ambas técnicas mejoran el equilibrio dinámico y la agilidad al inicio de la sesión. El vendaje funcional y la ortesis no producen ningún efecto sobre el salto horizontal con una pierna, sin embargo, reducen el salto horizontal con dos piernas en jugadores de baloncesto. De acuerdo con estos resultados, el vendaje funcional y la ortesis se consideran técnicas de inmovilización con capacidad de limitación de inversión de tobillo, que se podrían indicar en prevención y tratamiento de lesiones ligamentosas de esta articulación, sin repercutir en la funcionalidad del jugador de baloncesto.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 183-188).
The main contribution of this thesis is a new solution concept for symmetric games (of complete information in strategic form), the exchangeable equilibrium. This is an intermediate notion between symmetric Nash and symmetric correlated equilibrium. While a variety of weaker solution concepts than correlated equilibrium and a variety of refinements of Nash equilibrium are known, there is little previous work on "interpolating" between Nash and correlated equilibrium. Several game-theoretic interpretations suggest that exchangeable equilibria are natural objects to study. Moreover, these show that the notion of symmetric correlated equilibrium is too weak and exchangeable equilibrium is a more natural analog of correlated equilibrium for symmetric games. The geometric properties of exchangeable equilibria are a mix of those of Nash and correlated equilibria. The set of exchangeable equilibria is convex, compact, and semi-algebraic, but not necessarily a polytope. A variety of examples illustrate how it relates to the Nash and correlated equilibria. The same ideas which lead to the notion of exchangeable equilibria can be used to construct tighter convex relaxations of the symmetric Nash equilibria as well as convex relaxations of the set of all Nash equilibria in asymmetric games. These have similar mathematical properties to the exchangeable equilibria. An example game reveals an algebraic obstruction to computing exact exchangeable equilibria, but these can be approximated to any degree of accuracy in polynomial time. On the other hand, optimizing a linear function over the exchangeable equilibria is NP-hard. There are practical linear and semidefinite programming heuristics for both problems. A secondary contribution of this thesis is the computation of extreme points of the set of correlated equilibria in a simple family of games. These examples illustrate that in finite games there can be factorially many more extreme correlated equilibria than extreme Nash equilibria, so enumerating extreme correlated equilibria is not an effective method for enumerating extreme Nash equilibria. In the case of games with a continuum of strategies and polynomial utilities, the examples illustrate that while the set of Nash equilibria has a known finite-dimensional description in terms of moments, the set of correlated equilibria admits no such finite-dimensional characterization.
by Noah D. Stein.
Ph.D.

Orientador: Mario de Jesus Mendes
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: A simulação de processos é um componente fundamental de uma grande variedade de atividades de Engenharia de Processos, tais como a Otimização Online, o controle em Tempo Real, a Identificação, etc. O cálculo de Equilíbrio de Fases é uma atividade fundamental em qualquer simulação de processos de separação. O elevado tempo computacional deste cálculo provocado pela sua natureza iterativa pode criar incompatibilidades entre a atividade de simulação e as aplicações em tempo real que ela integra. O objetivo deste trabalho foi desenvolver um método alternativo simples, mas suficientemente preciso, para realizar os cálculos de equilíbrio de fases na simulação de processos de separação de sistemas complexos. Entende-se por tal, sistemas que apresentam problemas de Equilíbrio Líquido-Líquido e de Equilíbrio Líquido-Líquido-Vapor, como é o caso dos que possuem um Azeótropo Heterogêneo. Pelas suas propriedades, as Redes Neurais Artificiais surgem naturalmente como candidatas alternativas para esta tarefa. Como objeto de aplicação foram escolhidos dois sistemas que apresentam um azeótropo heterogêneo, o sistema binário acetato de etila - água e o sistema ternário etanol - acetato de etila - água. Para gerar os dados usados no treinamento das redes foi implementado um método convencional de cálculo de equilíbrio de fases, adequado à complexidade dos sistemas escolhidos, o método de Pham & Doherty. Para a resolução do problema da estabilidade de fases, a primeira etapa do cálculo do equilíbrio de fases, foram testados dois tipos de redes neurais artificiais (RNAs), as Redes Neurais Artificiais Probabilísticas (RNAPs) e os Perceptrons. Com os perceptrons foram encontradas dificuldades para atingir a precisão desejada, sendo necessário recorrer a perceptrons com várias camadas escondidas. Já as RNAPs apresentaram uma excelente precisão, embora a sua simulação seja mais lenta. Perceptrons simples de uma só camada escondida foram usados com êxito na solução da segunda etapa do cálculo de equilíbrio de fases, o problema da divisão de fases. Combinando as redes desenvolvidas para cada uma das etapas foi criada uma ferramenta que permite resolver qualquer problema de equilíbrio de fases para os sistemas estudados. A precisão dos resultados fornecidos pelas redes neurais é comparável à dos apresentados pelos métodos tradicionais, mas os cálculos do equilíbrio de fases feitos usando redes neurais foram mais rápidos. Pode-se concluir que as redes neurais artificiais constituem uma alternativa válida aos métodos tradicionais do cálculo do equilíbrio de fases baseados em equações de estado para sistemas complexos como os avaliados
Abstract: Process simulation is a basic component of different Process Engineering activities such as On-line Optimization, Model Predictive Control, Identification, etc. The calculation of Phase Equilibrium appears as a fundamental task in any simulation of a separation process. However, the high computational time due to the iterative nature of this calculation makes it oft unsuitable for use with real time process analysis and synthesis strategies. The objective of this work is to develop a simple but accurate method to perform the phase equilibrium calculations required to the study of the behavior of complex systems. As such we mind those systems who present liquid-liquid and vapor-liquid-liquid phase equilibrium problems, such as systems with a heterogeneous azeotrope do. Given their inherent ability to learn and recognize non-linear and highly complex relationships, artificial neural networks (ANNs) appear to be well suited for such a task. Two chemical systems, the binary ethyl acetate ¿ water and the ternary ethanol ¿ ethyl acetate ¿ water were chosen; both systems present a miscibility gap and a heterogeneous azeotrope. The data sets used to train the ANNs were computed using the method of Pham & Doherty. Two kinds of neural networks were tried to solve the phase stability problem, namely the probabilistic neural networks (PNNs) and the perceptrons. In order to attain an acceptable precision perceptrons had to be trained with several hidden layers. Even though, PNNs got slightly better results than the perceptrons. Simple perceptrons were able to deliver the required precision when trained to predict the compositions of phases in equilibrium. Coupling the ANNs trained for phase stability with those trained for phase division a tool was obtained that can solve any phase equilibrium problem for the two chosen systems. Predictions made with the use of neural networks were faster than those made using the traditional methods, and delivered comparable precision
Doutorado
Sistemas de Processos Quimicos e Informatica
Doutor em Engenharia Química

Orientadores: Reginaldo Guirardello, Gustavo Paim Valença
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Essa pesquisa consiste em aplicar métodos de otimização global para o cálculo do equilíbrio químico e de fases combinados para misturas com gás de síntese. O gás de síntese tem grande interesse industrial, pelas inúmeras possibilidades de produção de diversos compostos químicos. Dessa forma, é fundamental conhecer as condições termodinâmicas que favoreçam a obtenção de determinado produto. A aplicação de métodos de otimização global é de grande interesse para a determinação do equilíbrio, uma vez que permite realizar em um único procedimento o cálculo de equilíbrio e a análise de estabilidade de fases. Como estudos de caso, o método é aplicado em um conjunto de situações que consiste em 280 compostos em potencial que geram como produtos: o gás de síntese a partir do metano e vapor d¿água ¿ já que os reatores operam em condições próximas ao equilíbrio; a produção de hidrocarbonetos e a produção de metanol a partir do gás de síntese. Afim de atingirmos o objetivo dessa pesquisa, observamos que apenas as situações para produção de gás de síntese não necessitam de restrições para incluir a influência do catalisador. Os demais produtos derivados requerem algum tipo de restrição adicional, como evitar a formação de metano e coque. Trabalhamos com o software comercial GAMS, aplicamos o solver CONOPT 2 o qual utiliza-se da PNL (Programação Não-Linear) para a resolução, o modelo caracteriza-se como convexo. Aplicamos métodos de programação matemática diferenciados no intuito de estudarmos o desempenho de cada um
Abstract: This research consists of applying methods of global optimization for chemical equilibrium calculation and combined phases for mixtures with synthesis gas. The synthesis gas has great industrial interest, for the innumerable possibilities of various chemical composite productions. Of this form, is basic to know the thermodynamic conditions which favor the attainment of definitive product. The application of methods of global optimization has great interest for the determination of the equilibrium, a time that allows determining through in an only procedure the calculation of equilibrium and the analysis of stability of phases. As case study, the method is applied in a set of reactions that generate as product the synthesis gas. Since the reactors operate in conditions near the equilibrium, we will apply methods of similar mathematical programming differentiated to study the performance of each one
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química

Ce travail se concentre sur l'étude de jeux joués sur des graphes finis, parun nombre arbitraire de joueurs, dont les objectifs ne sont pas antagonistes.Chaque joueur représente un agent, c'est-à-dire un programme, un processus,ou un périphérique, qui interagit avec les autres joueurs et leurenvironnement commun dans le but de satisfaire au mieux son objectifindividuel.Des concepts telsque les équilibres de Nash, permettant d'exprimer l'optimalité des stratégiesdes joueurs, ont été étudiés dans un cadre déterministe, et l'existencede tels équilibres n'est pas assurée, même lorsque les objectifs des joueurssont de simples conditions d'accessibilité ou de sûreté. En effet, lorsqueles joueurs jouent de manière déterministe, le système évolue en conservantune certaine symmétrie, ce qui nous motive à considérer un modèle stochastiqueoù les joueurs et l'environnement sont sources d'aléa. Dans le premier cas,nous montrons que les concepts classiques d'équilibres de Nash ne peuventêtre calculés, et introduisons des notions approchées d'équilibrescalculables. Dans le deuxième cas, nous nous intéressons à l'analyse desystèmes composés d'un nombre arbitraires de processus, dont l'éxécutionest déterminée par un ordonnanceur, c'est-à-dire l'environnement,probabiliste
We study games played on graphs by an arbitrary number of players withnon-zero sum objectives. The players representagents (programs, processes or devices) that can interact to achieve their ownobjectives as much as possible. Solution concepts, as Nash Equilibrium, forsuch optimal plays,need not exist when restricting topure deterministic strategies, even with simple reachability or safetyobjectives. The symmetry induced by deterministic behavioursmotivates the studies where eitherthe players or the environment can use randomization. In the first case, weshow that classical concepts are undecidable with a fixednumber of agents and propose computable approximations.In the second case, we studyrandomization as a reasonable policy for scheduling an arbitrary number ofprocesses

Orientador: Watson Loh
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Polieletrólitos associam-se fortemente com surfatantes de carga oposta em meio aquoso, levando a uma separação de fases que resulta em uma fase concentrada, rica em polieletrólito e surfatante, em equilíbrio com uma fase diluída constituída pelos contra-íons. A fase concentrada pode ser constituída de interessantes estruturas supramoleculares advindas das propriedades de auto-organização destes sistemas, que aliadas à possibilidade de modificaremse a geometria da mesofase e as distâncias entre os agregados, tornam estes sistemas ferramentas importantes em processos de fabricação de estruturas micro e mesoporosas e em sistemas de liberação controlada de drogas. O estudo do equilíbrio de fases de sistemas constituídos por polieletrólitos e surfatantes de cargas opostas em água não é tão simples devido ao grande número de componentes presentes no sistema, porém é possível reduzir a quantidade de componentes através da síntese do sal complexo ¿puro¿ (polieletrólito-surfatante), facilitando dessa forma a análise dos diagramas de fases gerados. Neste trabalho o comportamento de fases de sais complexos formados pelo íon surfatante hexadeciltrimetilaônio (CTA) e pelo polieletrólito (PA) em água e na presença de diferentes solventes orgânicos foi investigado. Três efeitos principais foram analisados: efeito da natureza do solvente orgânico; efeito da adição de uma série homóloga de álcoois e efeito da hidrofobicidade do contra-íon polimérico. Os resultados obtidos indicam que a polaridade do solvente orgânico utilizado influencia intensamente nas estruturas formadas pelo sal complexo. Em geral, observou-se a predominância de estruturas lamelares em sistemas contendo co-surfatantes (n-álcoois) e a predominância de estruturas hexagonais em sistemas contendo p-xileno e ciclohexano. A hidrofobicidade do contra-íon polimérico não gerou mudanças significativas nos diagramas de fases obtidos.
Abstrat: Association between charged polymers and oppositely charged surfactants in aqueous solutions may lead to phase separation forming a concentrated phase rich in polyions and surfactant ions, and a more dilute phase, which mostly contains simple ions. The concentrated phases may display a variety of supramolecular structures with diverse and interesting features due to self-assembling properties of these systems, which have found applications in the field of controlled drug delivery and in templating the synthesis of materials with tailored geometries. A complete description of the phase equilibrium in these systems is quite demanding, because addition of polyelectrolyte and oppositely charged surfactant to water leads to the formation of several components, however it is possible to reduce the number of the components by the preparation of the pure complex-salt, which allows to analyze the phase equilibrium in a controlled manner. In this work the phase behavior of complex salts formed by the surfactant ion hexadecyltrimethylammonium (CTA) and the polyacrylate (PA) in water and with different organic solvents were investigated. Three principal effects were analyzed: the effect of the organic solvent nature; the effect of n-alcohol carbon chain length and the effect of the polyelectrolyte hidrophibicity. The obtained results revealed that the organic solvent nature has a strong influence in the structure assumed by the complex salt. From the general analysis, systems containing co-surfactants (n-alcohols) a predominance of lamellar structures was observed, and in systems containing p-xylene and ciclohexane a predominance of hexagonal structures was detected. The polyelectrolyte hidrophobicity did not display significant changes in the obtained phase diagrams.
Doutorado
Físico-Química
Doutor em Ciências

Orientador:Irenilza de Alencar Naas
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola.
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Resumo: Durante o período de lactação, as fêmeas suínas devem consumir níveis adequados de ração para mantença e produção de leite. O baixo consumo resulta em mobilização das reservas corporais, condição corporal inadequada, falhas reprodutivas e redução no tempo de vida útil das fêmeas no rebanho, principalmente nas condições de temperatura ambiente elevada. A hipótese desse trabalho foi que, o sistema de resfriamento evaporativo associado ao uso da dieta com balanço eletrolítico, pode favorecer o conforto térmico das fêmeas suínas em lactação, durante a exposição ao calor ambiente excessivo e, consequentemente, minimizar os efeitos prejudiciais do estresse calórico sobre o desempenho. O experimento foi realizado em uma granja comercial com 72 fêmeas suínas da genética DanBred® e objetivou avaliar os efeitos do sistema de ventilação e da dieta sobre o desempenho e os parâmetros de termorregulação de porcas lactantes durante o verão. O delineamento experimental foi blocos ao acaso com quatro tratamentos em disposição fatorial 2 x 2 e 18 repetições por tratamento. Os tratamentos foram dois sistemas de ventilação (ventilação natural ou resfriamento evaporativo) e duas dietas (balanço eletrolítico natural de 175 mEq kg-1 ou balanço eletrolítico ajustado de 275 mEq kg-1). Os resultados foram submetidos à análise de variância utilizando o programa Minitab®15.1. Foram registrados os dados de temperatura ambiente, umidade relativa do ar, velocidade do ar, iluminância e características físico-químicas da água. Foram calculados o índice de conforto térmico e o retorno econômico do investimento. Foram monitorados os dados fisiológicos (frequência respiratória, temperatura retal, temperatura superficial, concentração de sódio, potássio e cloretos na urina e concentração de cortisol salivar) e de desempenho das porcas (consumo de ração, condição corporal e intervalo desmame-estro) e dos leitões. As variáveis de termorregulação e os resultados de desempenho das porcas e dos leitões também foram avaliados de acordo com a ordem de parto. Não houve efeito significativo do sistema de ventilação e da dieta sobre o consumo de ração, a condição corporal e o intervalo desmame-estro das porcas. O sistema de resfriamento evaporativo proporcionou redução (P<0,05) na frequência respiratória e temperatura superficial mensuradas nos períodos da manhã e da tarde e na temperatura retal à tarde e aumento (P<0,1) no peso dos leitões ao desmame. A dieta com ajuste do balanço eletrolítico não promoveu diferença nestas variáveis. Fêmeas primíparas apresentaram menor (P<0,05) frequência respiratória, consumo de ração, peso dos leitões ao nascimento e ao desmame, peso corporal e espessura de toucinho e maior intervalo desmame estro, comparando-se às fêmeas multíparas. Concluiu-se que a utilização do sistema de resfriamento evaporativo contribuiu para reduzir os efeitos do calor sobre as variáveis relacionadas à termorregulação das porcas em lactação durante o verão e proporcionou aumento no peso dos leitões ao desmame. Em dieta com níveis nutricionais específicos para climas quentes, o ajuste do balanço eletrolítico não minimizou os efeitos do estresse calórico. A ordem de parto apresentou influência direta na frequência respiratória, consumo de ração e condição corporal das fêmeas, intervalo desmame-estro, e no peso dos leitões ao desmame
Abstract: During the lactation period, sows should consume adequate levels of feed for their maintenance and the milk production. The low consumption results in mobilization of body reserves, poor body condition, reproductive failure and reduced life span of females in the herd, especially under conditions of high ambient temperature. The hypothesis of this study was that evaporative cooling system associated with the use of dietary electrolyte balance might favor the thermal comfort of lactating sows during exposure to extreme environmental heat and, therefore, reduce the harmful effects of heat stress on performance. The field trial was conducted in a commercial farm with 72 sows genetics DanBred® and aimed to evaluate the effects of the ventilation system and diet on the performance and thermoregulatory parameters of lactating sows during summer. The experimental design was randomized blocks with four treatments in a factorial arrangement 2 x 2 and 18 replicates per treatment. Treatments were two ventilation systems (natural ventilation or evaporative cooling) and two diets (natural electrolyte balance of 175 mEq kg-1 or electrolyte balance setting of 275 mEq kg-1). Results were subjected to analysis of variance using software Minitab®15.1. Regarding the variables related to the environment, temperature, relative humidity, air velocity, luminance and water physic-chemical characteristics we recorded. We calculated the thermal comfort index and financial return on investment. Physiological data (respiratory rate, rectal temperature, surface temperature, concentration of sodium, potassium and chlorides in urine and concentration of salivary cortisol) and of sows performance (feed intake, body condition and weaning-estrus interval) and piglets performance results were also recorded. The variables of thermoregulation and performance results of sows and piglets were also evaluated according to the order of parity. There was no significant effect of ventilation systems and diet on feed intake, body condition and weaning-to-estrus interval of sows. The evaporative cooling caused a significant reduction (P<0.05) in respiratory rate and surface temperature measurements in the morning and afternoon and evening rectal temperature and increase (P<0.1) weight of piglets at weaning. The dietary adjusted electrolyte balance did not change these variables. Primiparous females had lower respiratory rate (P<0.05) than multiparous females, feed intake, weight of piglets at birth and weaning, body weight, back fat thickness and higher weaning-estrus interval, compared to the multiparous females. It was concluded that the use of the evaporative cooling system helped to reduce the effects of heat on the variables related to body thermoregulation during the summer and provided an increase in weaning piglets weight. The utilization of a diet with specific nutrient levels for hot climates, adjusting the electrolyte balance did not reduce the effects of heat stress in sows. Parity order had a direct impact on respiratory rate, feed intake and body condition of females, weaning-to-estrus interval and weight of piglets at weaning
Doutorado
Construções Rurais e Ambiencia
Mestre em Engenharia Agrícola

Ce travail décrit l'étude de différents paramètres qui influent sur les propriétés d'adsorption de composés poreux organométalliques (MOFs). Nous avons utilisé les techniques de volumétrie et de gravimétrie d'adsorption et les systèmes adsorbables sont la série des alcanes linéaires (du n-pentane au n-nonane). Les solides étudiés sont les MIL-47(V), MIL-53(Cr, Al, Fe), les MIL-53(Fe)-X modifiés et la série MIL-88(Fe)-A, B, C. Parmi les nombreuses conclusions de cette étude, nous pouvons en détailler plusieurs : (i) la flexibilité des MIL-53(Cr, Al, Fe), rendue possible par la présence de µ2-OH coordinés aux centres métalliques, dépend de l'identité des centres métalliques et de celle de l'adsorbable. (ii) la modification chimique, par substitution d'un atome d'hydrogène porté par les noyaux aromatiques des ligands, induit une variation dans le degré de flexibilité des structures et dans la stabilité des différentes phases. (iii) la nature des ligands, dans la série des MIL-88(Fe), en termes de nombre de noyaux aromatiques constituent les ligands, modifie les interactions physiques au sein des réseaux organométalliques ce qui a un effet sur leur stabilité et leur flexibilité.(iv) la facilité de la diffusion des alcanes linéaires, de longueur différente, dans les pores des solides dépend notamment des points développés ci-dessus
This study describes a study of the adsorptive properties of several flexible porous organometallic frameworks (MOFs) using the volumetric and gravimetric methods and apolar normal alkanes (n-pentane to n-nonane) as adsorbate molecules. The materials studied are MIL-47(V), MIL-53(Cr, Al, Fe), the modified MIL-53(Fe)-X and the MIL-88(Fe)-A, B, C.This allows the study of different parameters on the behaviour of the solids during the adsorption process. Amongst the findings of this study, several can be emphasized :(i) the flexibility of the MIL-53(Cr, Al, Fe), made possible by the presence of µ2-OH coordinated to the metal centres, depends on the identity of the metal centres and that of the adsorbate.(ii) the chemical modification by the substitution of a hydrogen atom on the aromatic ligands of the MIL-53(Fe) induces a change in the degree of flexibility of the framework and the stability of the various phases.(iii) the nature of the ligands in the MIL-88(Fe) series, in terms of the number of the aromatic rings comprising the linker, changes the physical interactions within the framework and thus its stability and flexibility.(iv) the ease of diffusion into the pores of the alkanes of various alkyl chain length depends on the three points mentioned above

This thesis aims to contribute to a fundamental objective of Network Economics: to provide based incentives explanations of real social network topologies. By using game theoretical tools, the three papers of this thesis analyze how real social networks can arise from the strategic interaction of self-interested individuals.
In the first paper, we discuss the influence of imperfect information on the process of social network formation and, specifically, on the possibilities of observing racially segregated societies when agents' preferences are not racially biased. The second work attempts to complete the Network Economics' explanation of the puzzle regarding how agents can benefit from structural holes over a long time period. The third paper presents a model that focuses on the mechanisms underlying the formation of scientific collaboration networks. We show how researchers' heterogeneity and limited processing capability explain the basic characteristics of these networks.
Aquesta tesi aspira a contribuir a un objectiu fonamental de l'Economia de Xarxes: oferir explicacions basades en els incentius de les topologies que adopten les xarxes socials. Usant les eines de la Teoria de Jocs, els tres articles de la tesi analitzen com les xarxes socials que observem a la realitat poden esser fruit de la interacció entre individus que responen als seus propis interessos.
En primer lloc, estudiem la influència de la informació imperfecte en la formació de xarxes socials i, específicament, en les possibilitats de tenir societats racialment segregades quan les preferències dels agents no estan racialment esbiaixades. El segon treball, intenta completar l'explicació que l'Economia de Xarxes dóna a l'interrogant referent als forats estructurals i a la gent que s'en beneficia de manera continuada. El darrer capítol, se centra en els mecanismes que expliquen la formació de xarxes de col·laboració científica. Es mostra com l'heterogeneïtat i la limitada capacitat de processament dels investigadors expliquen les caractarístiques bàsiques d'aquestes xarxes.

Orientador: Fernando Antonio Cabral
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho foi estudado o fracionamento de óleo de palma bruto (Elaes guineensi) com dióxido de carbono supercrítico; mediu-se a solubilidade, a composição em ácidos graxos, carotenóides totais, tocoferóis, tocotrienóis e ácidos graxos livres. Foi determinado o equílibro de fases no intervalo de pressão de 100 a 350 bar e nas temperaturas de 40, 50 e 60°C. A quantificação dos componentes minoritários presentes nos extratos foi feita por espectrofotometria para a determinação de carotenóides totais, por cromatografia líquida de alta eficiência para a determinação dos tocoferóis e tocotrienóis e por titulação potenciométrica para os ácidos graxos livres. Realizou-se uma extração fracionada utilizando raspas de madeiras como suporte na condição de 40°C a 200 bar, onde doze amostras foram extraídas, nas quais mediu-se a solubilidade e a concentração de ácidos graxos livres e carotenóides totais. Observou-se que a composição em ácidos graxos do óleo de palma refinado e a composição dos extratos em equilíbrio com o CO2 apresentaram pequenas variações na concentração dos ácidos palmítico, oléico e linoléico. Os valores de coeficiente de distribuição, que indicam o grau de fracionamento entre as fases, foram menores que a unidade para tocoferóis e carotenóides e maiores que a unidade para ácidos graxos livres. Notou-se que o comportamento do equilíbrio de fases, transcrito em termos dos coeficientes de distribuição, concorda com os valores da literatura, exceto para os tocoferóis onde o comportamento foi diferente daqueles reportados na litertura
Abstract: In this work was studied the fractionation of crude oil palm (Elaes guineensi) with supercritical carbon dioxide; it measured solubility, the free fatty acids composition, carotenoids totals, tocochromanols and free fatty acids. Was determined equilibrium phase in the interval at pressure of 100 at 350 bar and temperature of 40, 50 and 60°C. The quantification of the minor components present in extracts was made by spectrometer for the determination of carotenoids totals, liquid chromatography of high efficiency for the determination of tocochromanols and potenciometric titration for determination free fatty acids. Were fulfilled extraction fractionated using wood scraps as support in condition of 40°C at 200 bar, where twelve sample had been extracted, in which it measured the solubility and the concentration of free fatty acid and carotenoids totals. It was observed that the free fatty acid composition of refined oil palm and the composition the extracts in equilibrium with CO2 had present small variations in the palmitic acid, oleic acid and linoleic acid. The values separation factor, that indicate the degree of fractionation between the phase were smaller than unit for tocochromanols, carotenoids totals and bigger than unit for free fatty acids. It was noticed that the behavior of equilibrium phase, transcript in term of the separation factor, had agreed to the values of literature, except for the tocochromanols where the behavior was different of those reported in the literature
Mestrado
Mestre em Engenharia de Alimentos

In the present work, Current Reversal Equilibrium Configurations (CRECs) in the context of Magnetohydrodinamic (MHD) equilibrium are considered. The hamiltonian nature of the magnetic field lines is used to introduce the concept of magnetic surfaces and their relation to the Grad-Shafranov (G-S) equation. From a geometrical perspective and the Maxwell equations, it is shown that current reversal configurations in two-dimensional equilibrium do not generate the usual nested topology of the equilibrium magnetic surfaces. The concept of intersecting critical curves is introduced to describe the CRECs and recently published equilibria are shown to be compatible with such description. The equilibrium with a single magnetic island is constructed analytically, through a local successive approximations method, valid for any choice of the source functions of the G-S equation. From the local solution, an estimate of the island width in terms of simple quantities is deduced and verified to a good accuracy with recently published CRECs; the accuracy of this simple model suggests the existence of strong topological constraints in the formation of the equilibria. Lastly, an instability mechanism is conjectured to explain the lack of conclusive experimental evidence of reversed currents, in favor of the current clamp hypothesis.
No presente trabalho, as configurações de equilíbrio com corrente reversa (CRECs), são consideradas no contexto de Equilíbrio Magnetoidrodinâmico. A natureza hamiltoniana das linhas de campo magnético é usada para introduzir o conceito de superfícies magnéticas, e sua relação com a equação de Grad-Shafranov (G-S). Desde uma perspectiva geométrica e usando as equações de Maxwell, é demonstrado que as configurações de corrente reversa em equilíbrios bidimensionais não é compativel com as topologias aninhadas usuais para as superfícies magnéticas de equilíbrio. O conceito de curvas críticas é introduzido para descrever as CRECs e é observado que os equilíbrios recentemente publicados satisfazem esta descrição. O equilíbrio com uma única ilha magnética é construído analiticamente, por meio de aproximações sucessivas locais, este é válido para qualquer escolha das funções arbitrárias da equação G-S. A partir da solução local, se desenvolve uma estimativa do tamanho da ilha magnética em termos de quantidades simples. Esta estimativa concorda bem com as CRECs da literatura recente, sugerindo pela simplicidade do modelo, que existem fortes restrições topológicas no estabelecimento do equilíbrio. Finalmente, na forma de conjectura, introduzimos um mecanismo para instabilidades que tenta dar conta da falta de evidência experimental conclusiva em relação às CRECs em favor da hipótese de corrente unidirecional (current clamp).

We modify the concept of consistent expectations equilibria introduced in Hommes and Sorger (1998) in two ways: (i) the consistency condition requires that the probability that the agents reject their perceived law of motion in any period does not exceed a given level and (ii) there may exist exogenous stochastic shocks. The concept is illustrated by two examples using a linear economic system. In one of the examples consistency implies rational expectations, in the other example it does not. (authors' abstract)
Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

The problem of finding equilibria in non-cooperative games and understanding their properties is a central problem in modern game theory. After John Nash proved that every finite game has at least one equilibrium (so-called Nash equilibrium), the natural question arose whether we can compute one efficiently. After several years of extensive research, we now know that the problem of finding a Nash equilibrium is PPAD-complete even for two-player normal-form games, making the task of finding approximate Nash equilibria one of the central questions in the area of equilibrium computation. In this thesis our main goal is a new study of the complexity of various variants of the approximate Nash equilibrium. Specifically, we study algorithms for additive approximate Nash equilibria in bimatrix and multi-player games. Then, we study algorithms for relative approximate Nash equilibria in multi-player games. Furthermore, we study algorithms for optimal approximate Nash equilibria in bimatrix games and finally we study the communication complexity of additive approximate Nash equilibria in bimatrix games.

This thesis studies various equilibrium concepts in the context of finite games of infinite duration and in the context of bi-matrix games. We considered the game settings where a special player - the leader - assigns the strategy profile to herself and to every other player in the game alike. The leader is given the leeway to benefit from deviation in a strategy profile whereas no other player is allowed to do so. These leader strategy profiles are asymmetric but stable as the stability of strategy profiles is considered w.r.t. all other players. The leader can further incentivise the strategy choices of other players by transferring a share of her own payoff to them that results in incentive strategy profiles. Among these class of strategy profiles, an 'optimal' leader resp. incentive strategy profile would give maximal reward to the leader and is a leader resp. incentive equilibrium. We note that computing leader and incentive equilibrium is no more expensive than computing Nash equilibrium. For multi-player non-terminating games, their complexity is NP complete in general and equals the complexity of computing two-player games when the number of players is kept fixed. We establish the use of memory and study the effect of increasing the memory size in leader strategy profiles in the context of discounted sum games. We discuss various follower behavioural models in bi-matrix games assuming both friendly follower and an adversarial follower. This leads to friendly incentive equilibrium and secure incentive equilibrium for the resp. follower behaviour. While the construction of friendly incentive equilibrium is tractable and straight forward the secure incentive equilibrium needs a constructive approach to establish their existence and tractability. Our overall observation is that the leader return in an incentive equilibrium is always higher (or equal to) her return in a leader equilibrium that in turn would provide higher or equal leader return than from a Nash equilibrium. Optimal strategy profiles assigned this way therefore prove beneficial for the leader.

It has been supposed since the middle of this century that it is the global magnetic field surrounding a quiescent prominence that provides the force to prevent its collapse due to the sun's gravitational field. Many theoretical models, assuming that the prominence plasma is supported in a dip in the magnetic field lines associated by the magnetic tension force, have since been put forward. The aim of this thesis is to propose further models of quiescent prominences to widen our understanding and knowledge of these remarkable features. A short overview over the magnetohydrodynamic equations used to describe solar prominences, or most of the solar phenomena for that matter, are discussed in chapter 2, and a short summary of prominence observations and attempts to model them is given in chapter 3. A brief description of the numerical code used in chapters 5 and 7 is given in chapter 4. Observations of Kim (1990) and Leroy (1985) have found that most large quiescent prominences are of inverse polarity type for which the magnetic field passes through the prominence in the opposite direction to that expected from the photospheric magnetic field. Many theoretical models have been proposed, but failed. Hence, in chapter 5 we investigate first – without the inclusion of a prominence sheet – when an inverse polarity magnetic field must have the correct topology for an inverse polarity configuration before the formation of the prominence itself. Only very recently, the first basic successful model of an I-type polarity prominence was proposed by Low (1993). In chapter 6 we examine this model and investigate current sheets more complicated and realistic than the one used by Low. These analytical models deal with the force-free solution, which is matched onto an external, unsheared, potential coronal magnetic field. These solutions are mathematically interesting and allow an investigation of different profiles of the current intensity of the magnetic field vector and of the mass density in the sheet. The prominence properties predicted by these models have been examined and have been found to match the observational values. The mathematics of current sheets in general is also briefly discussed. Chapter 7 deals with numerical solutions of inverse polarity prominences embedded in a force-free magnetic flux tube, matched onto an unsheared potential coronal field. Unfortunately the solutions gained are quite sensitive to the boundary conditions imposed on them through the numerical box, showing a loss of convergence and a tendency for the solution to blow up. Finally, a short summary as well as possible future work is given in chapter 8.