Dissertations / Theses on the topic 'PolyChord'

The object of this thesis is to lay open a repertory of music which has long been ignored, the music for two and more choirs composed by Roman composers of the generation of Palestrina and his immediate successors. Polychoral music is taken to mean music in which two or more independent and consistent groups of voices take part, singing separately and together; the parts should remain independent in tuttl sections, with the possible exception of the bass parts. By this definition, the first real polychoral music to be published in Rome was that by Giovanni P. da Palestrina in his Motettorum liber secundus of 1575. This is taken as the starting point for this study. Music which might have influenced Roman composers is examined, as well as eight-voice music by Roman composers which is not polychoral according to the above criteria. The development of polychoral music in the city is then traced through the reigns of the various popes from Gregory XIII to Paul V, whose death in 1621 is taken as a convenient place to end the study. Particular emphasis is laid on structural and textural aspects and the way these were adapted by successive composers. The ground for the Roman concerts to style was laid in the early experiments by composers such as Giovanni Animuccia, Palestrina and Tomas Luis de Victoria; this is traced through what is termed the 'fragmented' style of the last two decades of the sixteenth century to the full flowering of the large-scale concerts to motet after 1605. The music is studied in the context of the institutions for which it was written. The archives of these Institutions have been researched for information on performance practice, which is presented here. The broader cultural, social and religious background which spawned the idiom is also examined and polychoral music related both to the new propagandist attitude of church leaders from Gregory XIII onwards, and to a general expansion in musical activity in the city of Rome through the period under investigation. The various printed and manuscript sources for this music have been researched and the resulting catalogue of pieces by fifty or so composers who worked in the city is presented. A more detailed examination is carried out of the primary manuscript sources, from which valuable information on various aspects of the music can be obtained.

I devised and implemented a method for constructing regular andsemiregular geometric objects in n-dimensional Euclidean space.Given a finite reflection group (a Coxeter group) G, there is a standard way to give G a group action on n-space.Reflecting a point through this group action yieldsan object that exhibits the symmetries specified by G. If the pointis chosen well, the object is guaranteed to be regular or semiregular,and many interesting regular and semiregular objectsarise this way. By starting with the symmetry group, I can use thegroup structure both to simplify the actual graphics involved withdisplaying the object, and to illustrate various aspects of itsstructure. For example, subgroups of the symmetry group (and theircosets) correspond to substructures of the object. Conversely, bydisplaying such symmetric objects and their various substructures, Ifind that I can elucidate the structure of the symmetry group thatgives rise to them.I have written The Symmetriad, the computer system whose name thisdocument has inherited, and used it to explore 3- and 4-dimensionalsymmetric objects and their symmetry groups. The 3-dimensionalobjects are already well understood, but they serve to illustrate thetechniques used on the 4-dimensional objects and make them morecomprehensible. Four dimensions offers a treasure trove of intriguingstructures, many of which have no ready 3D analogue. These are what Iwill show you here.
MEng thesis

Les polychloro-biphenyles (pcb) sont des composes organiques de synthese consideres par la communaute internationale comme des polluants chimiques prioritaires. Leurs proprietes physico-chimiques, a l'origine de nombreuses applications industrielles, en font des molecules toxiques particulierement remanentes dans l'environnement. Leur resistance aux metabolismes et leur persistance dans l'environnement augmentent avec le nombre d'atomes de chlore portes par le biphenyle. Nous avons examine les possibilites offertes par la reaction de methanolyse pour la degradation des melanges techniques de polychloro-biphenyles. La composition du melange francais phenoclor dp 6 a ete determinee a 91%. La reaction a fait l'objet d'un plan d'experiences effectue sur le congenere 153, congenere majoritaire dans ce melange commercial possedant une teneur ponderale en chlore de 60%. Les conditions optimisees ont ete appliquees aux congeneres modeles et aux melanges techniques phenoclor dp 4, dp 5 et dp 6 produits par prodelec. La dechloration de pcb modeles a ete prealablement etudiee : les resultats montrent l'intervention des mecanismes de substitution nucleophile aromatique (snar) et d'hydro-dechloration. L'etude du potentiel inducteur par des derives methoxyles du congenere 77 du cytochrome p450 1a1 a revele une diminution d'un facteur vingt de l'activite erod. La reaction optimisee affecte tous les congeneres constituant les melanges techniques, entrainant une dechloration significative de ces derniers.

During the late sixteenth and early seventeenth centuries, Venetian society and politics could be considered as a "polychoral culture." The imagination of the republic rested upon a shared set of social attitudes and beliefs. The political structure included several social groups that functioned as identifiable entities; republican ideologies construed them together as parts of a single harmonious whole. Venice furthermore employed notions of the republic to bolster political and religious independence, in particular from Rome. As is well known, music often contributes to the production and transmission of ideology, and polychoral music in Venice was no exception. Multi-choir music often accompanied religious and civic celebrations in the basilica of San Marco and elsewhere that emphasized the so-called "myth of Venice," the city's complex of religious beliefs and historical heritage. These myths were shared among Venetians and transformed through annual rituals into communal knowledge of the republic. Andrea and Giovanni Gabrieli and other Venetian composers wrote polychoral pieces that were structurally homologous with the imagination of the republic. Through its internal structures, polychoral music projected the local ideology of group harmony. Pieces used interaction among hierarchical choirs - their alternation in dialogue and repetition - as rhetorical means, first to create the impression of collaboration or competition, and then to bring them together at the end, as if resolving discord into concord. Furthermore, Giovanni Gabrieli experimented with the integration of instrumental choirs and recitative within predominantly vocal multi-choir textures, elevating music to the category of a theatrical religious spectacle. He also adopted and developed richer tonal procedures belonging to the so-called "hexachordal tonality" to underscore rhetorical text delivery. If multi-choir music remained the central religious repertory of the city, contemporary single-choir pieces favored typical polychoral procedures that involve dialogue and repetition among vocal subgroups. Both repertories adopted clear rhetorical means of emphasizing religious notions of particular political significance at the surface level. Venetian music performed in religious and civic rituals worked in conjunction with the myth of the city to project and reinforce the imagination of the republic, promoting a glorious image of greatness for La Serenissima.

Orientador: Antonio Rafael Carvalho dos Santos
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes
Made available in DSpace on 2018-08-08T03:10:40Z (GMT). No. of bitstreams: 1 Lima_AdrianoFagundesOliveira_M.pdf: 1384309 bytes, checksum: 009724025c8fc3ab9b2f5d9cd9d8d8fb (MD5) Previous issue date: 2006
Resumo: O presente trabalho ocupa-se em pesquisar os policordes, formações acordais compostas pela sobreposição de uma ou mais tríades ou tétrades sobre uma base simples ou composta, discutindo as diferentes formas como são encontrados e oferecendo uma proposta de sistematização. Por tratar-se de uma linguagem relativamente nova, procurou-se primeiramente investigar como eles são apresentados conceitualmente e graficamente nos trabalhos de diversos autores e sugerir uma sistematização baseada nessas informações. Em seguida, buscou-se identificar, com base nesta proposta de sistematização, sua utilização no repertório de música brasileira
Abstract: This work is concerned in researching the polychords, chordal structures formed by the superimposition of one or more triads or thetrads over a simple or complex base, discussing the different ways they are found and proposing a system for it¿s use. Being such a new language, primarily this work searches for how they are presented both conceptually and graphically in different works of several authors and suggests a system based upon these informations. Secondly, this work tries to identify, based upon this system proposal, the use of the polychords in popular music
Mestrado
Mestre em Música

Bayesian statistics is an alternative approach to traditional frequentist statistics that is rapidly gaining adherents across different scientific fields. Although initially only accessible to statisticians or mathematically-sophisticated data analysts, advances in modern computational power are helping to make this new paradigm approachable to the everyday researcher and this dissemination is helping open doors to problems that have remained unsolvable or whose solution was extremely complicated through the use of classical statistics. In spite of this, many researchers in the behavioural or educational sciences are either unaware of this new approach or just vaguely familiar with some of its basic tenets. The primary purpose of this thesis is to take a well-known problem in psychometrics, the estimation of the polychoric correlation coefficient, and solve it using Bayesian statistics through the method developed by Albert (1992). Through the use of computer simulations this method is compared to traditional maximum likelihood estimation across various sample sizes, skewness levels and numbers of discretisation points for the latent variable, highlighting the cases where the Bayesian approach is superior, inferior or equally effective to the maximum likelihood approach. Another issue that is investigated is a sensitivity analysis of sorts of the prior probability distributions where a skewed (bivariate log-normal) and symmetric (bivariate normal) priors are used to calculate the polychoric correlation coefficient when feeding them data with varying degrees of skewness, helping demonstrate to the reader how does changing the prior distribution for certain kinds of data helps or hinders the estimation process. The most important results of these studies are discussed as well as future implications for the use of Bayesian statistics in psychometrics

La tomate est susceptible aux attaques de plusieurs agents phytopathogènes. Pour lutter contre ces agents phytopathogènes, des conservateurs chimiques sont utilisés pendant l’entreposage mais ils sont néfastes pour la santé humaine et l’environnement. Le chitosane, produit naturel respectueux de l’environnement et sans danger pour la santé humaine, est connu pour son effet antimicrobien. Toutefois, son efficacité est moindre contre les champignons Zygomycètes et pourrait être améliorée par chloration. Le but de ce projet était de vérifier l’amélioration du potentiel antimicrobien de polychloro-chitosane en vue de son emploi pour la conservation post-récolte de la tomate. Les effets antimicrobiens de quatre doses (1000, 2000, 3000 et 4000 ppm) de polychloro-chitosane et de chitosane natif ont été évalués in vitro contre les phytopathogènes suivants: Mucor sp., Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia sp., Geotrichum candidum, Colletotrichum coccodes, Bacillus subtilis, Escherichia coli, Lactobacillus plantarum, Pseudomonas cichorii, Pseudomonas syringae et Xanthomonas campestris. Exprimés en facteur d’amélioration (FA), ces effets sont notés excellents (FA˃3.5), très bons (FA situé entre 3.5 à 2.5), bons (FA situé entre < 2.5 à 1.5), faibles (FA situé entre < 2.5 à 1.5 uniquement à 3000 et 4000 ppm) et nuls (FA< 1.5). Les mêmes doses de polychloro-chitosane et de chitosane natif ont été testées pour le contrôle de la moisissure grise de la tomate. Selon l’organisme considéré, l’amélioration de l’activité antimicrobienne de chitosane polychloré s’est avérée excellente (Mucor sp.), très bonne (Rhizoctonia sp.), bonne (E. coli), faible (B. cinerea, P. cichorii, P. syringae, X. campestris) ou nulle (S. sclerotiorum, C. coccodes, G. candidum, B. subtilis et L. plantarum). Par ailleurs, le chitosane polychloré s’est révélé plus efficace que le chitosane natif pour le contrôle du développement de la moisissure grise. Les potentiels bioactif et bio-conservateur de polychloro-chitosane s’avèrent prometteurs mais ne sont pas satisfaisants. Cela est en partie attribuable à sa faible solubilité. Des travaux complémentaires s’avèrent nécessaires pour améliorer cette solubilité en modulant les niveaux de chloration et de désacétylation.
Tomato is susceptible to attacks by several phytopathogenic agents. Chemical preservatives are used during storage but are detrimental to human health and the environment. Chitosan, a natural product that is environmentally friendly and safe for human health, is known for its antimicrobial effect. However, this effect is low against Zygomycetes and could be improved by chlorination. The aim of this project was to verify the improvement of the antimicrobial potential of polychloro-chitosan for its use in the tomato postharvest preservation. The antimicrobial effects of four doses (1000, 2000, 3000 and 4000 ppm) of polychloro-chitosan and native chitosan were evaluated in vitro for the following phytopathogenics: Mucor sp, Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia sp, Geotrichum candidum, Colletotrichum coccodes, Bacillus subtilis, Escherichia coli, Lactobacillus plantarum, Pseudomonas cichorii, Pseudomonas syringae and Xanthomonas campestris. Expressed as improvement factor (FA), these effects were rated excellent (FA˃3.5), very good (FA between 3.5 to 2.5), good (FA between ˂2.5 to 1.5), low (FA between ˂2.5 to 1.5 only in 3000 and 4000 ppm) and nil (FA < 1.5). The same doses of polychlorinated chitosan and native chitosan were tested for control of gray mold in tomato. According to the organism, improving the antimicrobial activity of polychlorinated chitosan has been excellent (Mucor sp.), very good (Rhizoctonia sp.), good (E. coli), low (B. cinerea, P. cichorii, P. syringae, X. campestris) or nil (S. sclerotiorum, C. coccodes, G. candidum, B. subtilis and L. plantarum). In addition, more tomatoes were preserved from gray mold by polychloro-chitosan than native chitosan. The bioactive and biopreservation potentials of polychloro-chitosan are promising but not satisfying. This is due in part to its low solubility. Further works are required to improve this solubility by modulating the levels of chlorination and deacetylation.

Les médicaments sont fréquement retrouvés dans les effluents de STEP relargués dans l’environnement aquatique. Dans le but de prévenir et de mieux comprendre les impacts des médicaments sur les écosystèmes aquatiques, il semble pertinent d’évaluer les perturbations comportementales, physiologiques et transcriptomiques des psychotropes sur les organismes aquatiques. Dans ce contexte, l’objectif de cette étude a été d’évaluer les perturbations induites par 4 psychotropes (oxazépam, carbamazépine, cyamémazine et sertraline) chez deux organismes, Radix balthica et Schmidtea polychroa. Pour ce faire, des embryons de Radix au stade trochophore et des planaires adultes ont été exposés à chaque psychotrope (du μg/L jusqu’à 100 μg/L). Il en ressort que les psychotropes allongent la durée du développement embryonnaire du Radix et perturbent le déplacement, la reproduction et la digestion, mais pas la régénération de la planaire. D’un point de vue transcriptomique, nous avons réalisé le séquençage du transcriptome en conditions différentielles chez le Radix. Ainsi, nous avons obtenu d’une part les séquences du transcriptome et d’autre part, après analyse en différentiel, 144 contigs différentiellement exprimés par l’oxazépam parmi lesquels 94 ont été vérifiés en RT-qPCR chez des Radix exposés à chaque psychotrope. Il ressort de cette analyse que les psychotropes impactent principalement la voie de signalisation Notch, mais aussi les voies de biosynthèse des polyamines et des catécholamines. Les psychotropes modulent aussi l’expression de gènes codant des protéines de la Matrice Extra Cellulaire (MEC), comme la Matriline ou encore la Dentine sialophosphoprotéine. Chez la planaire, nous avons analysé l’expression de 87 gènes impliqués dans différentes fonctions. Il ressort de cette étude que les 4 psychotropes modulent l’expression de nombreux gènes impliqués dans la mobilité ciliaire et musculaire et dans les systèmes nerveux, reproducteur, excréteur et digestif
Pharmaceuticals are often found in WWTP effluents realesed in surface water. In order to prevent and to understand the pharmaceuticals impact on aquatic ecosystems, it seems relevant to evaluate behavioural, physiological and transcriptomic disturbances of psychotropics on freshwater organisms. The aim of this study was thus to analyse disturbances of 4 psychotropics (oxazepam, carbamazepine, cyamemazine and sertraline) on 2 freshwater organisms, Radix balthica and Schmidtea polychroa. In our experiments, both Radix embryos at the trochophore stage and mature planarian were exposed to each psychotropic (from 1 to 100 μg/L). This psychotropic exposure results in an increase of the duration of Radix embryonic development and a disturbance of the mobility, the reproduction and the digestion but not the regeneration of planarian. Regarding the transcriptomic impact, we performed RNA sequencing in differential conditions of Radix embryos exposed or not to oxazepam. On one hand, this analysis allowed us to obtain the transcriptome sequences and, on the other hand, 144 contigs differentially expressed among which 94 genes were verified by RT-qPCR. The results showed that psychotropics impact mainly the Notch signalling pathways, but also the biosynthetic pathways of polyamines and catecholamines. Psychotropics also disturb the gene expression encoding some Extra Cellular Matrix (ECM) protein such as Matrilin and Dentin sialophosphoprotein. Regarding the molecular study of the psychotropics impact on planarian, we analysed the expression of 87 genes involved in different functions. The results showed that the 4 psychotropics modulate expression of genes involved in ciliary and muscular motility and in the nervous, reproductive and excretory systems. Genes from the digestive system are also impacted by the psychotropics. All the observed impacts on the 2 organisms suggest a possible disturbance on the population fitness and therefore on the freshwater ecosystems

This thesis is concerned with methods for Bayesian inference and their applications in astrophysics. We principally discuss two related themes: advances in nested sampling (Chapters 3 to 5), and Bayesian sparse reconstruction of signals from noisy data (Chapters 6 and 7). Nested sampling is a popular method for Bayesian computation which is widely used in astrophysics. Following the introduction and background material in Chapters 1 and 2, Chapter 3 analyses the sampling errors in nested sampling parameter estimation and presents a method for estimating them numerically for a single nested sampling calculation. Chapter 4 introduces diagnostic tests for detecting when software has not performed the nested sampling algorithm accurately, for example due to missing a mode in a multimodal posterior. The uncertainty estimates and diagnostics in Chapters 3 and 4 are implemented in the $\texttt{nestcheck}$ software package, and both chapters describe an astronomical application of the techniques introduced. Chapter 5 describes dynamic nested sampling: a generalisation of the nested sampling algorithm which can produce large improvements in computational efficiency compared to standard nested sampling. We have implemented dynamic nested sampling in the $\texttt{dyPolyChord}$ and $\texttt{perfectns}$ software packages. Chapter 6 presents a principled Bayesian framework for signal reconstruction, in which the signal is modelled by basis functions whose number (and form, if required) is determined by the data themselves. This approach is based on a Bayesian interpretation of conventional sparse reconstruction and regularisation techniques, in which sparsity is imposed through priors via Bayesian model selection. We demonstrate our method for noisy 1- and 2-dimensional signals, including examples of processing astronomical images. The numerical implementation uses dynamic nested sampling, and uncertainties are calculated using the methods introduced in Chapters 3 and 4. Chapter 7 applies our Bayesian sparse reconstruction framework to artificial neural networks, where it allows the optimum network architecture to be determined by treating the number of nodes and hidden layers as parameters. We conclude by suggesting possible areas of future research in Chapter 8.

La formació d’un sistema nerviós fou una innovació clau en l’evolució dels animals que va permetre desenvolupar una comunicació ràpida i eficient entre les cèl·lules d’un organisme a mesura que n’augmentava la complexitat. Analitzar la neurogènesi embrionària en el major nombre possible d’organismes és, per tant, necessari per reconstruir quin fou el mode ancestral de neurogènesi als metazous. Recentment s’ha descrit que el procés de formació d’aquest sistema d’òrgans pot ser acotat a una sèrie de passos discrets que estan controlats per xarxes gèniques comunes entre organismes model ben establerts. En general, el primer pas d’aquest procés es caracteritza per la separació de l’ectoderma neurogènic i epitelial durant la gastrulació de l’embrió; posteriorment, l’ectoderma neurogènic, o neuroectoderma, es regionalitza en els diferents eixos de coordenades i s’amplifica en quant a nombre de cèl·lules, i, finalment, dona lloc al sistema nerviós. Als Spiralia, un dels dos principals clades d’animals protòstoms, els estudis sobre les qüestions relacionades amb aquests processos s’han centrat als mol·luscs i anèl·lids mentre que poc se sap de la resta de fílums. Així doncs, en aquesta tesi ens hem plantejat utilitzar la planària d’aigua dolça Schmidtea polychroa, un platihelmint amb un sistema nerviós morfològicament simple, per a caracteritzar l’organogènesi dels sistemes nerviosos central, perifèric, i visual, i, posteriorment, analitzar alguns dels mòduls conservats de la neurogènesi dels organismes bilaterals. La nostra estratègia s’ha basat en l’estudi del marcatge amb anticossos neurals i amb l’anàlisi de l’expressió de gens pan-neurals i de subpoblacions neuronals per proposar un model de desenvolupament del sistema nerviós durant l’embriogènesi d’aquella espècie. Els resultats d’aquesta tesi demostren l’origen de novo a l’estadi 4 i a partir d’una població de cèl·lules embrionàries determinades d’aquell sistema d’òrgans; posteriorment, aquestes cèl·lules conjunten en un primordi nerviós bilateral situat al futur pol ventral de l’embrió que serà l’origen d’estructures nervioses com el cervell o els cordons nerviosos laterals i ventrals. A més, també hem determinat la dinàmica temporal i espaial de desenvolupament dels ulls durant l’embriogènesi més tardana; en concret, aquests òrgans es formen a la part més anterior de l’organisme i des d’una cèl·lula precursora comuna que, més tard, es separarà en els primordis de l’ull dret i esquerra. Finalment, hem aïllat i caracteritzat gens ortòlegs del grup soxB i un conjunt de membres dels bHLH proneurals, que són famílies gèniques amb un paper ben establert en la determinació de l’ectoderma neurogènic i l’especificació neuronal, així com també de gens associats amb la diferenciació dels ulls, com ara els membres de la xarxa gènica controlada per pax6 i també altres factors de transcripció com rx, otxA o atonal. L’anàlisi molecular d’aquests mostra, per una banda, que un ortòleg de la família soxB1 es detecta en el presumptiu neuroectoderma de l’embrió i en cèl·lules progenitores neuronals, mentre que els gens de les famílies soxB2, achaete-scute, neuroD i beta3, així com alguns dels gens relacionats amb el desenvolupament dels ulls, estan associats amb l’especificació de poblacions neuronals. En conjunt, els nostres resultats suggereixen que els principals mecanismes moleculars de control de la neurogènesi es troben substancialment conservats als tríclads, tot i que aquests animals mostren un patró embrionari que divergeix clarament de l’ancestral de la resta d’organismes espirals. En resum, la nostra tesi expandeix la comprensió actual de la neurogènesi dels animals bilaterals i, alhora, proporciona un marc bàsic per a futurs estudis sobre el desenvolupament embrionari de les planàries.
The development of a nervous system is a key innovation in the evolution of metazoans, which is illustrated by the presence of a common developmental toolkit for the formation of this organ system. Neurogenesis in the Spiralia, and in particular the Platyhelminthes, is, however, poorly understood when compared with other animal groups. In this thesis we used the planarian Schmidtea polychroa, a free-living flatworm with a morphologically simple nervous system, as a model organism for studying the organogenesis of the central, peripheral and visual nervous systems. Using a combination of immunolabelling and gene expression analysis of neural-specific markers we show that the nervous system is formed de novo from a population of embryonic cells when the embryo adopts the definitive axial identities. Later on, these cells aggregate in a bilateral neural primordium which differentiates the brain, and the ventral and lateral nerve cords. Also, during this late embryonic phase, the eyes develop in the anterior-most part of the organism from a shared precursor. To further understand the early steps of neurogenesis, we isolate and characterize soxB and a set of bHLH genes, which are gene families with a well-established role in metazoan neural development, and genes associated with the specification of eye cell types -in particular, the pax6-gene network and transcription factors of the otx and rx families. Thus, we demonstrate that soxB1-1 is expressed in the putative neuroectoderm and neural progenitor cells, whereas soxB2, neural bHLH genes (achaete-scute, neuroD and beta3), and the eye-related genes so, eya and otxA are associated with the specification of neural subpopulations. Altogether, our findings suggest that the ancestral neural-specific gene regulatory network is substantially conserved in triclad, despite exhibiting a divergent mode of development. In summary, this thesis expands the current understanding of bilaterian neurogenesis and provides a basic framework for further studies in planarian embryonic development.
La formación de un sistema nervioso fue una innovación clave en la evolución de los animales que permitió desarrollar una comunicación rápida y eficiente entre las células de un organismo a medida que aumentaba la complejidad. Analizar la neurogénesis embrionaria en el mayor número posible de organismos es, por lo tanta, necessario para reconstruir cual fue el modo ancestral de neurogénesis de los metazoos. Recientemente se ha descrito que ese proceso puede ser definido con un conjunto de pasos o etapas que están controlados por redes génicas comunes entre organismos modelo bien establecidos. En general, el primer paso de la neurogénesis implica la separación del ectodermo neurogénico y epitelial durante la gastrulación del embrión; posteriormente, el ectodermo neurogènico, o neuroectodermo, se regionaliza en los principales ejes de coordenadas y se amplifica en cuanto a número de células y, finalmente, da lugar a las células nerviosas. En los organismos del grupo de los Spiralia, uno de los dos principales clados de protóstomos, los estudios sobre temas relacionados con esas etapas se han centrado en los moluscos y anélidos mientras que poco se sabe del resto de filos del grupo. Así pues, en esta tesis doctoral nos hemos planteado utilizar la planaria de agua dulce Schmidtea polychroa, un platihelminto con un sistema nervioso morfológicamente simple, para caracterizar la organogénesis de los sistemas nerviosos central, periférico, y visual, y, posteriormente, analizar algunos de los módulos conservados de la neurogénesis de los organismos bilaterals. Inicialmente nuestra estrategia se basó en el estudio del marcaje con anticuerpos específicos neurales y con el análisis de la expresión de genes pan-neurales y de subpoblaciones neuronales para proponer un modelo de desarrollo del sistema nervioso durante la embriogénesis de esta especie. Los resultados de nuestra tesis demuestran el origen de novo en el estadio 4 y a partir de una población de células embrionarias determinadas del sistema nerviosos definitivo; más tarde, estas células se condensan en un primordio nervioso bilateral situado en el futuro polo ventral del embrión que será el origen de estructuras como el cerebro o los cordones laterales y ventrales. Además, también hemos determinado la dinámica temporal y espacial de desarrollo de los ojos durante las etapas más tardías de la embriogénesis: estos órganos se forman en la parte más anterior del embrión y a partir de unas células precursoras comunes que se separarán en los primordios de los ojos derecho e izquierdo. Por último, hemos aislado y caracterizado genes ortólogos del grupo soxB y un conjunto de miembros de los bHLH proneurales, que son familias génicas con un papel bien establecido en la determinación del ectodermo neurogénico y la especificación neuronal, y también de genes asociados con la diferenciación de los ojos, como por ejemplo los miembros de red génica controlada por pax6 y también otros factores de transcripción como rx, otx o atonal. Su análisis molecular muestra que un ortólogo del grupo soxB1 se detecta en el putativo neuroectodermo del embrión y en células progenitoras neuronales de S. polychroa, mientras que los genes de los grupos soxB2, achaete-scute, neuroD y beta3, así como algunos genes relacionados con el desarrollo de los ojos, están asociados con la especificación de diferentes poblaciones neuronales. En conjunto, nuestros datos sugieren que, a pesar de que los tríclados muestran un patrón de desarrollo del zigoto que difiere claramente del patrón típico de la segmentación espiral, los principales mecanismos moleculares de control de la neurogénesis se encuentran conservados en su grupo. En resumen, nuestra tesis doctoral expande la comprensión sobre el desarrollo del sistema nerviosos de los bilaterales a la vez que proporciona un marco básico para futuros estudios con embriones de planarias.

Cette thèse porte sur l’Institution harmonique, un traité manuscrit composé par Charles Guillet entre 1640 et 1647, dédié à l’archiduc Léopold-Guillaume. Une étude introductoire précède la transcription de la dédicace, de la préface et du premier livre (le seul qui subsiste). Elle met en lumière l’auteur Charles Guillet (ca. 1575-1654), une figure originale mais peu connue dans le paysage musical et apporte des éclairages sur la source manuscrite (notamment organisation, contenu et dessein théorique). La construction de son discours est enfin analysée à travers l’usage des sources (choix des autorités et compilation de deux « phares harmoniques » qu’étaient Zarlino et Salinas). Par la mise en scène de controverses, Guillet démontre la supériorité de la division syntone sur la diatone et justifie la théorie modale de Zarlino. Dans le premier livre sur « la Theorie, ou Speculative Musicale », la théorie arithmétique des rapports et des proportions est appliquée aux intervalles puis aux questions pratiques du tempérament
This dissertation deals with the Institution Harmonique, a hand written treatise, composed by Charles Guillet between 1640 and 1647, dedicated to Archduke Leopold Wilhelm. An introductory study precedes the transcription of the dedication, preface and Part 1 (the only one remaining to this day). It introduces author Charles Guillet (ca. 1575-1654), an original yet poorly known figure of the musical scene. You will find some specifications regarding the hand-written source (organisation, content and theoretic purpose). I will analyse the construction of discourse through the use of the various sources (choice of authorities and compilation of Zarlino and Salinas, two « harmonic lighthouses ». By staging of controversies, Guillet demonstrates the superiority of syntonic tuning on Pythagorean tuning and justifies the zarlinian modal theory. In the Part 1 on « The Theory, or musical speculative », the arithmetic theory of ratios and proportions is applied to the intervals then to the practical questions regarding temperament

The 24-item scale has been used extensively to assess the attitudes towards AIDS precautions. This study investigated the usefulness and validity of the instrument in a South African setting, fourteen years after the development of the instrument. If a new structure could be found statistically, the HIV/AIDS prevention strategies could be more effective in aiding campaigns to change attitudes and sexual behaviour.

Previous research has individually assessed parallel analysis and minimum average partial for factor retention in exploratory factor analysis using ordinal variables. The current study is a comprehensive simulation study including the manipulation of eight conditions (type of correlation matrix, sample size, number of variables per factor, number of factors, factor correlation, skewness, factor loadings, and number of response categories), and three types of retention methods (minimum average partial, parallel analysis, and empirical Kaiser criterion) resulting in a 2 × 2 × 2 × 2 × 2 × 3 × 3 × 4 × 5 design that totals to 5,760 condition combinations tested over 1,000 replications each. Results show that each retention method performed worse when utilizing polychoric correlation matrices. Moreover, minimum average partials are quite sensitive to factor loadings and overall perform poorly compared to parallel analysis and empirical Kaiser criterion. Empirical Kaiser criterion performed almost identical to parallel analysis in normally distributed data; however, performed much worse under highly skewed conditions. Based on these findings, it is recommended to use parallel analysis utilizing principal components analysis with a Pearson correlation matrix to determine the number of factors to retain when dealing with ordinal data.

This study investigates the most important reasons behind the rst-year students' decision to select University of the Western Cape (UWC) as higher education institution.
These reasons were organized into a few factors for easy interpretation. The data to be analyzed for this project is a subsection of the data collected during the orientation period of 2008. During the orientation week of 2008, the questionnaires were completed on a voluntary basis by new rst-year students. All questionnaires were anonymously completed and therefore the data does not contain any information that could be linked to any individual. For the purpose of this study, only the black African and coloured students were considered. The other racial groups were not analyzed due to too small sample sizes. Questionnaires with missing information on the reasons for selecting UWC were not 
nalyzed. We ended up with a sample of size 600. The data were statistically analyzed, using descriptive statistics, bivariate analyses, factor analysis, coefficient of congruence and bootstrap factor analysis. The results indicated that the most important reasons aecting students to choose UWC were identied as good academic reputation, family member's advice, UWC graduates are successful and UWC graduates get good jobs. The least important reasons were found to be not accepted anywhere, parents / family members graduated from UWC, recruited by UWC and wanted to study near to home. The results also indicated that there were significant differences among students according to population groups, parent's monthly income and grade 12 average. Factor analysis of 12 variables yielded three extracted factors upon which student decisions were based. Similarities of these three factors were tested, and a high similarity among demographic characteristics and grade 12 average were found. Additional analyses were conducted to measure the accuracy of factor analyses models constructed using Spearman and Polychoric correlation matrices. The results indicated that both correlation matrices were 
nbiased, with higher variance and higher loadings when the Polychoric correlation matrix was used to construct a factor analysis model for categorical data.

This thesis presents work around 3 themes: dark energy, gravitational waves and Bayesian inference. Both dark energy and gravitational wave physics are not yet well constrained. They present interesting challenges for Bayesian inference, which attempts to quantify our knowledge of the universe given our astrophysical data. A dark energy equation of state reconstruction analysis finds that the data favours the vacuum dark energy equation of state $w {=} -1$ model. Deviations from vacuum dark energy are shown to favour the super-negative ‘phantom’ dark energy regime of $w {< } -1$, but at low statistical significance. The constraining power of various datasets is quantified, finding that data constraints peak around redshift $z = 0.2$ due to baryonic acoustic oscillation and supernovae data constraints, whilst cosmic microwave background radiation and Lyman-$\alpha$ forest constraints are less significant. Specific models with a conformal time symmetry in the Friedmann equation and with an additional dark energy component are tested and shown to be competitive to the vacuum dark energy model by Bayesian model selection analysis: that they are not ruled out is believed to be largely due to poor data quality for deciding between existing models. Recent detections of gravitational waves by the LIGO collaboration enable the first gravitational wave tests of general relativity. An existing test in the literature is used and sped up significantly by a novel method developed in this thesis. The test computes posterior odds ratios, and the new method is shown to compute these accurately and efficiently. Compared to computing evidences, the method presented provides an approximate 100 times reduction in the number of likelihood calculations required to compute evidences at a given accuracy. Further testing may identify a significant advance in Bayesian model selection using nested sampling, as the method is completely general and straightforward to implement. We note that efficiency gains are not guaranteed and may be problem specific: further research is needed.

This thesis, which consists of five papers, is concerned with various aspects of confirmatory factor analysis (CFA) of ordinal variables and the generation of non-normal data. The first paper studies the performances of different estimation methods used in CFA when ordinal data are encountered.  To take ordinality into account the four estimation methods, i.e., maximum likelihood (ML), unweighted least squares, diagonally weighted least squares, and weighted least squares (WLS), are used in combination with polychoric correlations. The effect of model sizes and number of categories on the parameter estimates, their standard errors, and the common chi-square measure of fit when the models are both correct and misspecified are examined. The second paper focuses on the appropriate estimator of the polychoric correlation when fitting a CFA model. A non-parametric polychoric correlation coefficient based on the discrete version of Spearman's rank correlation is proposed to contend with the situation of non-normal underlying distributions. The simulation study shows the benefits of using the non-parametric polychoric correlation under conditions of non-normality. The third paper raises the issue of simultaneous factor analysis. We study the effect of pooling multi-group data on the estimation of factor loadings. Given the same factor loadings but different factor means and correlations, we investigate how much information is lost by pooling the groups together and only estimating the combined data set using the WLS method. The parameter estimates and their standard errors are compared with results obtained by multi-group analysis using ML. The fourth paper uses a Monte Carlo simulation to assess the reliability of the Fleishman's power method under various conditions of skewness, kurtosis, and sample size. Based on the generated non-normal samples, the power of D'Agostino's (1986) normality test is studied. The fifth paper extends the evaluation of algorithms to the generation of multivariate non-normal data.  Apart from the requirement of generating reliable skewness and kurtosis, the generated data also need to possess the desired correlation matrices.  Four algorithms are investigated in terms of simplicity, generality, and reliability of the technique.

Using data envelopment analysis with principal components, we calculate an adoption-intensity index for herbicide-resistance best management practices (BMPs). Empirical results for over 1,100 farmers in twenty-two U.S. states suggest that many farmers could improve their herbicide resistance BMP adoption. Two-limit truncated regression results show that higher yields and a greater proportion of acres planted with Roundup Ready (R) seeds motivate weed BMP adoption. While soybean and corn farmers have lower adoption intensity than cotton farmers, farmer educational attainment and greater concern for herbicide effectiveness and for human and environmental safety are found to help increase the adoption of weed BMPs.

A modelagem de equações estruturais é uma técnica estatística multivariada que permite analisar variáveis que não podem ser medidas diretamente, mas que podem ser estimadas através de indicadores. Dado o poder que esta técnica tem em acomodar diversas situações em um único modelo, sua aplicação vem crescendo nas diversas áreas do conhecimento. Diante disto, este trabalho teve por objetivo avaliar a incorporação de indicadores categóricos ordinais em modelos de equações estruturais, fazendo um resumo dos principais procedimentos teóricos e subjetivos presentes no processo de estimação de um modelo, avaliando as suposições violadas quando indicadores ordinais são utilizados para estimar variáveis latentes e criando diretrizes que devem ser seguidas para a correta estimação dos parâmetros do modelo. Mostramos que as correlações especiais (correlação tetracórica, correlação policórica, correlação biserial e correlação poliserial) são as melhores escolhas como medida de associação entre indicadores, que estimam com maior precisão a correlação entre duas variáveis, em comparação à correlação de Pearson, e que são robustas a desvios de simetria e curtose. Por fim aplicamos os conceitos apresentados ao longo deste estudo a dois modelos hipotéticos com o objetivo de avaliar as diferenças entre os parâmetros estimados quando um modelo é ajustado utilizando a matriz de correlações especiais em substituição à matriz de correlação de Pearson.
The structural equation modeling is a multivariate statistical technique that allows us to analyze variables that cant be measured directly but can be estimated through indicators. Given the power that this technique has to accommodate several situations in a single model, its application has increased in several areas of the knowledge. At first, this study aimed to evaluate the incorporation of ordinal categorical indicators in structural equation models, making a summary of the major theoretical and subjective procedures of estimating the present model, assessing the assumptions that are violated when ordinal indicators are used to estimate latent variables and creating guidelines to be followed to correct estimation of model parameters. We show that the special correlations (tetrachoric correlation, polychoric correlation, biserial correlation and poliserial correlation) are the best choices as a measure of association between indicators, that estimate more accurately the correlation between two variables, compared to Pearsons correlation, and that they are robust to deviations from symmetry and kurtosis. Finally, we apply the concepts presented in this study to two hypothetical models to evaluate the differences between the estimated parameters when a model is adjusted using the special correlation matrix substituting the Pearsons correlation matrix.

This article explains what we mean by the unidimensionality of a measurement instrument, therefore we present some definitions and  theoretical contributions about this subject. Factor analysis is proposed as one of the many methods for assessing the unidimensionality of a measurement instrument. The use of Pearson correlations matrices on item-level factor analysis is identified as an important problem. Those correlations are problematic because items didn’t carry out the necessary assumptions in order to apply the Pearson correlation: interval-level measurement and normal distribution of the variable. As an alternative we propose and exemplify the use of tetrachoric and polychoric correlations.
Este artículo explica qué es lo que implica la unidimensionalidad de un instrumento de medición. Para ello se presentan algunas definiciones y aportes teóricos sobre el tema. Luego, el análisis factorial es propuesto como uno de los métodos para evaluar la dimensionalidad de un instrumento de medición. Se señala como un problema importante el uso de las matrices de correlaciones de Pearson en los análisis factoriales a nivel de ítems. Estas correlaciones son problemáticas porque los ítems no cumplen con los supuestos necesarios para aplicar la correlación de Pearson: nivel de medición de intervalo y distribución normal de la variable. Como alternativa se postula y ejemplifica el uso de las correlaciones tetracóricas y policóricas.

La biphenyle dioxygenase (bdo) catalyse la dihydroxylation du biphenyle et des polychlorobiphenyles (pcb) chez la bacterie pseudomonas sp. B4, pour former un cis-dihydrodiol. C'est une enzyme a trois composantes : une dioxygenase (isp), une ferredoxine (fer) et une reductase (red). Le locus bpha codant la bdo b4 a ete clone, sequence et surexprime chez e. Coli. Les composantes isp, fer et red ont ete isolees, et caracterisees au niveau biochimique et spectroscopique. Isp et fer possedent chacune un centre 2fe-2s de type rieske. Nous avons isole la composante red de comamonas testosteroni b-356, plus facile a obtenir que celle de b4, l'avons combinee aux composantes isp et fer de b4 afin de reconstituer un complexe catalytique actif in vitro. La cinetique d'oxydation du nadh par le complexe bdo a ete determinee in vitro par spectroscopie de fluorescence, l'oxydation concomitante du biphenyle et des pcb ayant ete suivie par chromatographies hplc et cpg/sm. Une bonne correlation a ete observee entre l'oxydation du nadh, la degradation du biphenyle ou du 4,4-chlorobiphenyle et l'apparition du dihydrodiol. Dans le cas des composes doublement substitues en ortho, qui ne sont pas oxydes par l'enzyme, on observe une oxydation du nadh non couplee a celle du substrat aromatique. La region situee en amont du locus bpha a ete clonee, sequencee et fusionnee au gene rapporteur gfp (green fluorescent protein) dans le but d'elaborer un biocapteur bacterien a pcb. Cette region possede 2 cadres de lecture de fonction inconnue (orf), dont l'un est homologue a un orf present dans l'operon de deux souches de pseudomonas degradant le naphtalene. Introduites chez la souche b4, les constructions n'ont induit aucun signal de fluorescence significatif en presence de biphenyle. Cependant, la souche b4 peut etre utilisee directement pour detecter le biphenyle dans une gamme de 10 a 100 ppm, par mesure de la fluorescence endogene de la bacterie.

Les composés organochlores sont particulièrement bien adaptés à l'étude des formes de transport et de distribution des polluants en Méditerranée. Mécanismes de transport de ces composés à travers l'équilibre phase particulaire-phase dissoute. A l'aide des trois réservoirs, atmosphère, eau, sédiment, on essaie de préciser les phénomènes propres à chaque interface.

Yiu Choi Fan.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (leaves 69-71).
Abstracts in English and Chinese.
Abstract --- p.i
Acknowledgement --- p.iii
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Estimation with Known Misclassification Probabilities --- p.7
Chapter 2.1 --- Model --- p.7
Chapter 2.2 --- Maximum Likelihood Estimation --- p.9
Chapter 2.3 --- Standard Errors of the Parameter Estimates --- p.12
Chapter 3 --- Numerical Examples (I) --- p.13
Chapter 3.1 --- Analysis of Real Data --- p.13
Chapter 3.2 --- Analysis of Artificial Data --- p.16
Chapter 4 --- Simulation Study (I) --- p.19
Chapter 4.1 --- Simulation Algorithm --- p.19
Chapter 4.2 --- Simulation Design --- p.20
Chapter 4.3 --- Reported Statistics --- p.21
Chapter 4.4 --- Conclusions of Simulation Results --- p.22
Chapter 5 --- Estimation by Double Sampling Scheme --- p.24
Chapter 5.1 --- Introduction of Double Sampling Scheme --- p.24
Chapter 5.2 --- Model --- p.25
Chapter 5.3 --- Minimum Chi-square Estimation --- p.26
Chapter 5.4 --- Statistical Properties of the Parameter Estimates --- p.28
Chapter 6 --- Numerical Examples (II) --- p.30
Chapter 6.1 --- "Analysis of Real Data, (2x2 Table)" --- p.30
Chapter 6.2 --- Analysis of Artificial Data (3x3 Table) --- p.32
Chapter 7 --- Simulation Study (II) --- p.34
Chapter 7.1 --- Simulation Algorithm --- p.34
Chapter 7.2 --- Simulation Design --- p.35
Chapter 7.3 --- Reported Statistics --- p.37
Chapter 7.4 --- Conclusions of Simulation Results --- p.38
Chapter 8 --- Conclusions --- p.39
Appendices --- p.42
Chapter A.1 --- The proof of the expression for P(Zj = Ehk) --- p.42
Chapter A.2 --- The proof of puv and whk{uv) --- p.44
Chapter A.3 --- The proof of the covariance matrix Q --- p.47
Chapter A.4 --- The proof of the matrix Σ --- p.52
Tables A1-A9 --- p.54
Tables B1-B6 --- p.63
Bibliography --- p.69

by Kwan-Moon Leung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1990.
Bibliography: leaves 77-79.
Chapter Chapter 1 --- Introduction --- p.1
Chapter Chapter 2 --- Estimation of the Model with Some Polytomous Entries Missed --- p.5
Chapter §2.1 --- The Model --- p.5
Chapter §2.2 --- Full Maximum Likelihood (FML) Estimation --- p.7
Chapter Chapter 3 --- Estimation of the Model with Some Continuous and Polytomous Entries Missed --- p.13
Chapter §3.1 --- The Model --- p.13
Chapter §3.2 --- Pseudo Maximum Likelihood (PsML) Estimation --- p.15
Chapter Chapter 4 --- Indirect Methods --- p.19
Chapter §4.1 --- Listwise Deletion Method --- p.19
Chapter §4.2 --- Mean Imputation Method --- p.19
Chapter §4.3 --- Regression Imputation Method --- p.20
Chapter Chapter 5 --- Computation of the Estimates --- p.23
Chapter §5.1 --- Optimization Procedure --- p.23
Chapter §5.2 --- Starting Value and Gradient Vector of the Model with Some Polytomous Entries Missed --- p.25
Chapter §5.3 --- Starting Value and Gradient Vector of the Model with Some Continuous and Polytomous Entries Missed --- p.29
Chapter Chapter 6 --- Partition Maximum Likelihood (PML) Estimation --- p.35
Chapter §6.1 --- Motivation --- p.35
Chapter §6.2 --- PML Procedure of the Model with Some Polytomous Entries Missed --- p.35
Chapter §6.3 --- PML Procedure of the Model with Some Continuous and Polytomous Entries Missed --- p.37
Chapter Chapter 7 --- Simulation Studies and Comparison --- p.39
Chapter §7.1 --- Simulation Study I --- p.39
Chapter §7.2 --- Simulation Study II --- p.44
Chapter Chapter 8 --- Summary and Discussion --- p.43
Tables
Appendix
References

碩士
國立中山大學
音樂學系
87
The practice of the polychoral singing on psalm setting (i.e. salmi spezzati) became popular in some churches during the first half of the sixteenth-century in north Italy. The purpose of the thesis is the study of the development of cori spezzati from the beginning of the sixteenth-century to the date of the publication of the Salmi spezzati by Adrian Willaert in 1550. The research focuses study of the historical documents and manuscripts, which are provided by the libraries in Biblioteca Marciana di Venezia, Biblioteca Capitolare di Treviso, Biblioteca dell'Accademia Filarmonica di Verona and Biblioteca Civica Angelo Mai di Bergamo. In addition to the introduction, the thesis contains four chapters. The first chapter includes historical background on the tradition of the psalm singing, the falsobordone, and the term definition on cori spezzati. The second chapter is a thorough study of the composers and their works of the cori spezzati including Ruffino Bartolucci, Francesco Santacroce, Gaspar de Albertis and Adrian Willaert , who were active in the Republic of Venice during the first half of the sixteenth-century. The third chapter centers on the analytical study from the manuscripts of polychoral music. The final chapter contains the summary and conclusion of the study. From the study of the manuscripts of above mentioned composer's works, the ideal of the practice of breaking choirs was existed through the performance of psalm singing during the early sixteenth-century, but the texture and the frequency of alternating choir were variable. The treatment of breaking choirs in the works of Bartolucci show great freedom, and those compositions of Santacroce strictly follow the falsobordone tradition. The style of Willaert 's composition present imitative polyphonic texture, but the employing of alternating choirs shows extremely conservative. The development of the polychoral composition grew out from the practice of the falsobodone on psalm singing in the early sixteenth. Later, it was developed to a larger sacred works. Giovanni Gabrieli, a great Venetian composer in the late sixteenth, employed the ploychoral practice into his motets and instrumental works and led into a new era polychoral music.

abstract: Compared to sacred choral music of the great Spanish composers of the Renaissance, church music of later Spanish composers is relatively ignored, despite the fact that many left behind a significant body of works worthy of scholarly investigation and performance. In fact, there is a paucity of information on eighteenth-century church music in Spain - music history books generally treat the subject in the briefest way. To correct this situation, scholars must delve into the large caches of unpublished works from this period, which lie dormant in the archives of religious institutions. Even contextualizing these works is difficult, because so much remains to be unearthed. To help fill the lacuna of knowledge about this repertoire, I will shed light on the music of maestro de capilla José Gil Pérez (1715-1762), who was active at the cathedral of Segorbe, Spain from 1745 until his death in 1762, by presenting an edition of one of his vespers services. This service is comprised of a magnificat and three psalms (nos. 116, 122, and 147). These works, transcribed from the composer's autograph housed in the Segorbe cathedral, and written for SAT/SATB chorus and organ, will serve as a valuable contribution to the body of knowledge concerning choral music of the Spanish late Baroque. It will be seen that despite Gil Pérez's innovative use of "theatrical" instruments in the Segorbe cathedral and "Italianisms" in his villancicos, his compositional style in Latin works was largely conservative, in keeping with the practice of most maestros in Spain at this time. In fact his oeuvre demonstrates varying influences, largely dependent upon the genre. To contextualize this composer and his works, I will provide background information regarding music in the Segorbe cathedral during the century in question, including trends and influences, as well as information on Gil Pérez himself.
Dissertation/Thesis
D.M.A. Music 2013

La nourriture traditionnelle (NT) (résultant principalement des ressources halieutiques et cynégétiques) présente de nombreux bénéfices pour les communautés autochtones. Elle apporte beaucoup d'éléments essentiels pour le maintien d'une bonne santé. En effet, en plus d'être nutritive, la NT englobe plusieurs autres aspects. Culturellement, la chasse et la pêche permettent la transmission du savoir et des valeurs traditionnelles aux futures générations, tout en valorisant la coopération et la cohésion sociale. D'un point de vue économique, les activités traditionnelles contribuent à l'autosuffisance alimentaire et perpétuent également les activités artisanales traditionnelles. Ces activités renforcent les liens que les peuples des Premières Nations ont avec leur environnement. Pour les Autochtones, le concept d'une bonne santé, implique un maintien des aspects sociaux, culturels, spirituels, nutritionnels et économiques, qu'apporte la NT. Par contre, la consommation de NT expose ces populations à des substances potentiellement toxiques à leur santé. Les poissons et mammifères marins sont souvent contaminés par du méthylmercure (MeHg) et autres contaminants associés alors que le gibier ainsi que la sauvagine contiennent des polluants organiques persistants et autres métaux lourds comme le cadmium et le plomb. De par son caractère neurotoxique, le MeHg peut causer de graves répercussions sur la santé telles que des difficultés motrices, sensorielles et cognitives. Les personnes les plus à risque sont celles consommant de grandes quantités de poissons et/ou de mammifères marins, c'est-à-dire les populations autochtones et les pêcheurs sportifs ou des sous-groupes plus vulnérables tels les enfants et les femmes enceintes. Au Canada, certains peuples autochtones, tels que les Inuits et les Cris, ont été et sont encore étudiés dans le but d'évaluer et de mieux comprendre les risques d'une exposition aux divers contaminants présents dans leur environnement. À ce jour, aucune étude n'a porté sur les effets de l'exposition environnementale au mercure (Hg) et autres contaminants, de même qu'aux effets potentiellement néfastes sur la santé dans les communautés innues (ou montagnaises), qui sont culturellement et géographiquement différentes des communautés Inuites et Cries. Il est fort probable que ces différences territoriales se reflètent à travers les espèces animales consommées qui pourraient présenter des profils de contamination différents et conséquemment sur les risques d'expositions environnementales reliés à leur alimentation. Dans le cadre du projet multidisciplinaire COMERN (Collaborative Mercury Research Network) et en adoptant une approche écosystémique, au sein de la communauté innue de Sheshatshiu (Labrador), le sujet proposé dans le cadre de ce doctorat a permis d'évaluer, dans un premier temps, que les résultats de Hg dans les cheveux des participants de l'étude ont montré des niveaux étonnamment faibles (niveaux d'exposition jugés acceptables selon les recommandations de Santé Canada) par rapport à leur consommation de poissons. En tenant compte de plusieurs paramètres, les niveaux de Hg dans le poisson des différentes espèces consommées, le nombre de repas de poisson de chaque espèce ainsi que la taille des portions consommées, l'apport de Hg pour chaque participant fut calculé. Les niveaux de Hg capillaires de chaque participant ont été mesurés et comparativement aux niveaux attendus (par des simulations informatiques), les niveaux étaient dix fois moins élevés, suggérant des différences d'assimilation du Hg. Dans un deuxième temps, les résultats obtenus ont permis d'apprécier les bienfaits de l'alimentation traditionnelle des lnnus et les bienfaits de la NT selon les apports nutritionnels de référence et sur l'indice de masse corporelle. Dans un troisième temps, des altérations neurologiques précoces pouvant être associées à l'exposition au Hg et autres contaminants ont été évaluées selon trois domaines neurologiques (moteur, sensoriel et cognitif). Les principaux résultats ont démontré que les performances des trois domaines analysés étaient affectées par des profils de contamination différents. Et finalement, cette étude a permis de révéler trois groupes distincts en lien avec leurs performances aux tests neurofonctionnels (groupe bonne mémoire, groupe bonne vision et groupe avec difficultés). Les principales investigations effectuées sur le groupe avec difficultés, ont confirmé des niveaux de contaminants significativement plus élevés comparativement aux deux autres groupes (groupe bonne mémoire et groupe bonne vision), nonobstant l'âge et le nombre de repas traditionnels consommés. En analysant les informations colligées à l'aide des questionnaires sociodémographiques, .portant sur les lieux de chasse et de pêche visités par les familles innues, il a été possible d'établir qu'une partie des zones de chasse et de pêche utilisées par le groupe avec difficultés abritaient également des infrastructures militaires. Par ailleurs, des sources médiatiques et scientifiques ont rapporté, pour ces emplacements militaires, des déversements ou de la mauvaise gestion des déchets (métaux lourds et composés organochlorés) dans le passé, qui ont eu pour conséquences, selon ces mêmes sources, de contaminer les eaux et les sols environnants. Les résultats à venir seront les premiers à documenter les effets du Hg et autres contaminants au niveau d'une population adulte d'Innus et parmi les quelques études portant sur les effets d'une exposition multiple sur une population adulte (hommes et femmes). Ces résultats seront d'abord utiles pour la communauté autochtone. Les informations recueillies guideront les intervenants locaux pour monter un plan d'intervention, d'éducation et de gestion des ressources en combinant le savoir local et les données scientifiques générées par l'étude. Deuxièmement, les résultats serviront à la communauté scientifique qui s'intéresse à la problématique du Hg et autres contaminants ainsi qu'aux effets possibles chez les Premières Nations. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Innu, Nourriture traditionnelle, Contaminants, Métaux, Mercure, BPC, Pesticides organochlorés, Exposition multiple, Tests neurofonctionnels, Indice de masse corporelle, Territoire.