Dissertations / Theses on the topic 'MQF technique'

This work proposes the computational modeling of two-dimensional media mechanical behavior with a continuous approach, related to the Finite Element Method (FEM) associated with Cohesive Fracture Mechanics (CFM) models, and a discrete approach, using the Discrete Element Method (DEM). The FEM consists in a numerical tool widely used to achieve approximate solutions of Continuum Mechanics problems, involving physical and geometrical nonlinearities phenomena with quasi-static or dynamic behaviors, having already established practical applications in many areas of science and industry. On the other hand, DEM has more recent development and has been increasingly used to model discrete nature problems involving contact, impact and fragmentation phenomena and flow of particulate systems. Focused on analysis of problems with interactions between these natures, a FEMDEM coupling code is developed to solve the problem by a sub-region scheme where the FEM is used on modeling of nucleation process and crack propagation in continuous media, and DEM is employed to model granular media, whether due its nature or its conception, in a transient behavior. The possibility of opening and propagation of cracks is considered by using CFM models, intrinsically incorporated into the FEM formulation through interfaces inserted into the inner edges of the finite element mesh. Illustrative examples are presented and discussed in order to validate the proposed formulation and implementation.<br>FUNDEPES - Fundação Universitária de Desenvolvimento de extensão e Pesquisa<br>PRH-ANP - Programa de Recursos Humanos da Agência Nacional do Petróleo<br>Este trabalho propõe a modelagem computacional do comportamento mecânico bidimensional de meios com abordagens contínua, relacionada ao Método dos Elementos Finitos (MEF) associado a modelos da Mecânica da Fratura Coesiva (MFC) e discreta, através do Método dos Elementos Discretos (MED). O MEF consiste em uma ferramenta numérica bastante utilizada na determinação de soluções aproximadas para problemas da Mecânica do Contínuo, envolvendo fenômenos com não linearidades físicas e geométricas associadas e com comportamento quase-estático ou dinâmico, possuindo aplicações práticas já consagradas em diversas áreas do campo científico e industrial. Por outro lado, o MED tem desenvolvimento mais recente e vem sendo cada vez mais utilizado no tratamento de problemas de natureza discreta envolvendo fenômenos de contato, impacto, fragmentação e fluxo de sistemas particulados. Com foco na análise de problemas que envolvem interações entre tais naturezas, implementa-se uma estratégia de acoplamento MEF-MED para solução do problema em subregiões, onde o MEF é utilizado na modelagem de processos de nucleação e propagação de fraturas em meios contínuos e o MED é empregado na modelagem de meios granulares por natureza, ou assim concebidos, em comportamento transiente. A possibilidade de abertura e propagação de fraturas é considerada através da utilização de modelos da MFC, incorporados intrinsecamente na formulação do MEF através de interfaces inseridas nas arestas internas da malha de elementos finitos. Exemplos ilustrativos são apresentados e discutidos visando-se validar a formulação e a implementação propostas.

Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2006.<br>"A thesis in computer science." Typescript. Advisor: John H. Laity. Vita. Title from "catalog record" of the print edition Description based on contents viewed Nov. 1, 2007. Includes bibliographical references (leaves 81-88). Online version of the print edition.

Made available in DSpace on 2014-06-11T19:23:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-22Bitstream added on 2014-06-13T20:10:26Z : No. of bitstreams: 1 000749206.pdf: 2362410 bytes, checksum: f4f84a869a32983e7c75a2cda7ba0e17 (MD5)<br>A medicina nuclear é uma especialidade médica que se ocupa de técnicas de imagem para observar o estado fisiológico dos tecidos ou órgãos de forma não invasiva, através da marcação de moléculas participantes desses processos, com isótopos radioativos, originando assim os chamados radionuclídeos. O SPECT é um equipamento que se utiliza de imagens planares, obtidas de vários ângulos ao redor do objeto de interesse, e, através de algoritmos computacionais, obtêm uma imagem tomográfica dessas projeções. Sua origem remete há aproximadamente cinquenta anos atrás, com criação da Câmara Anger (Hall Anger, 1964). Durante todo esse tempo, embora tenha havido alguma evolução, a estrutura dessas gama câmaras praticamente ficou Inalterada. Os constantes avanços em pesquisas empregando cristais semicondutores nos exames cintilográficos, bem como a necessidade do surgimento de novos sistemas detectores, compactos, com maior poder de resolução e alta sensibilidade conjugados a crescente preocupação mundial com a minimização das doses de radiação ionizante utilizadas nos exames diagnósticos e terapias, impulsionou o desenvolvimento de novos sistemas detectores. Recentemente, duas Grandes Empresas lançaram comercialmente novos sistemas de detecção para aquisições tomográficas em medicina nuclear, utilizando detectores do estado sólido, mais especificamente cristais de telureto de cádmio e zinco (CZT). Algumas vantagens desse tipo de detector são a melhora sensível da relação sinal/ruído, o aumento da resolução espectral e espacial, o que em suma, resultam numa maior nitidez das imagens obtidas. O emprego desses detectores abre novas perspectivas para os protocolos de imagem. Entretanto, devido a inúmeros fatores, os equipamentos ditos CZT estão focados na área cardiológica, e devido a características próprias requerem a reformulação dos protocolos de aquisição de imagem além daqueles destinados ao...<br>Nuclear medicine is a medical specialty that deals with imaging techniques to observe the physiological status of the tissues or organs noninvasively, by dialing molecules participating in this process, with radioactive isotopes, thus giving the so-called radionuclides. The SPECT is a device that uses planar images, taken from different angles around the object of interest, and, through computer algorithms, obtains a tomographic image of those projections. Its origin refers for nearly fifty years ago, with the creation of the Chamber Anger (Anger Hall, 1964). Throughout this time, although there has been some evolution, the structure of these gamma cameras was virtually unchanged. The constant advances in research employing semiconductor crystals in scintigraphic examinations, as well as the need for the creation of new detectors systems, compacts, higher resolution and high sensitivity; combined with growing worldwide concern with minimization of doses of ionizing radiation used in diagnostic tests and therapies, spurred the development of new detector systems. Recently, two large companies launched commercially new detection systems for nuclear medicine tomographic acquisitions, using solid-state detectors, specifically crystals of zinc and cadmium telluride (CZT). Some advantages of this type of detector are sensitive improvement of signal / noise ratio, increased spectral and spatial resolution, which in short, resulting in greater clarity of the images obtained. The use of these detectors opens news perspectives for imaging protocols. However, due to numerous factors, equipment said CZT are focused on cardiology area, and due to the inherent characteristics, require reformulation of image acquisition protocols beyond those intended for Quality Control

Orientador: José Ricardo de Arruda Miranda<br>Banca: José Roberto Saglieti<br>Banca: Eder Rezende Moraes<br>Resumo: A medicina nuclear é uma especialidade médica que se ocupa de técnicas de imagem para observar o estado fisiológico dos tecidos ou órgãos de forma não invasiva, através da marcação de moléculas participantes desses processos, com isótopos radioativos, originando assim os chamados radionuclídeos. O SPECT é um equipamento que se utiliza de imagens planares, obtidas de vários ângulos ao redor do objeto de interesse, e, através de algoritmos computacionais, obtêm uma imagem tomográfica dessas projeções. Sua origem remete há aproximadamente cinquenta anos atrás, com criação da Câmara Anger (Hall Anger, 1964). Durante todo esse tempo, embora tenha havido alguma evolução, a estrutura dessas gama câmaras praticamente ficou Inalterada. Os constantes avanços em pesquisas empregando cristais semicondutores nos exames cintilográficos, bem como a necessidade do surgimento de novos sistemas detectores, compactos, com maior poder de resolução e alta sensibilidade conjugados a crescente preocupação mundial com a minimização das doses de radiação ionizante utilizadas nos exames diagnósticos e terapias, impulsionou o desenvolvimento de novos sistemas detectores. Recentemente, duas Grandes Empresas lançaram comercialmente novos sistemas de detecção para aquisições tomográficas em medicina nuclear, utilizando detectores do estado sólido, mais especificamente cristais de telureto de cádmio e zinco (CZT). Algumas vantagens desse tipo de detector são a melhora sensível da relação sinal/ruído, o aumento da resolução espectral e espacial, o que em suma, resultam numa maior nitidez das imagens obtidas. O emprego desses detectores abre novas perspectivas para os protocolos de imagem. Entretanto, devido a inúmeros fatores, os equipamentos ditos CZT estão focados na área cardiológica, e devido a características próprias requerem a reformulação dos protocolos de aquisição de imagem além daqueles destinados ao ...<br>Abstract: Nuclear medicine is a medical specialty that deals with imaging techniques to observe the physiological status of the tissues or organs noninvasively, by dialing molecules participating in this process, with radioactive isotopes, thus giving the so-called radionuclides. The SPECT is a device that uses planar images, taken from different angles around the object of interest, and, through computer algorithms, obtains a tomographic image of those projections. Its origin refers for nearly fifty years ago, with the creation of the Chamber Anger (Anger Hall, 1964). Throughout this time, although there has been some evolution, the structure of these gamma cameras was virtually unchanged. The constant advances in research employing semiconductor crystals in scintigraphic examinations, as well as the need for the creation of new detectors systems, compacts, higher resolution and high sensitivity; combined with growing worldwide concern with minimization of doses of ionizing radiation used in diagnostic tests and therapies, spurred the development of new detector systems. Recently, two large companies launched commercially new detection systems for nuclear medicine tomographic acquisitions, using solid-state detectors, specifically crystals of zinc and cadmium telluride (CZT). Some advantages of this type of detector are sensitive improvement of signal / noise ratio, increased spectral and spatial resolution, which in short, resulting in greater clarity of the images obtained. The use of these detectors opens news perspectives for imaging protocols. However, due to numerous factors, equipment said CZT are focused on cardiology area, and due to the inherent characteristics, require reformulation of image acquisition protocols beyond those intended for Quality Control<br>Mestre

Transmissions are an essential part of a vehicle powertrain. An optimally designed powertrain can result in energy savings, reduced environmental impact and increased comfort and reliability. Along with other components of the powertrain, efficiency is also a major concern in the design of transmissions. The churning power losses associated with the motion of gears through the oil represent a significant portion of the total power losses in a transmission and therefore need to be estimated. A lack of reliable empirical models for the prediction of these losses has led to the emergence of CFD (Computational Fluid Dynamics) as a means to (i) predict these losses and (ii) promote a deeper understanding of the physical phenomena responsible for theselosses in order to improve existing models. The commercial CFD solver STAR-CCM+ is used to investigate the oil distribution and the churning power losses inside two gearbox configurations namely an FZG (Technical Institute for the Study of Gears and Drive Mechanisms) gearbox and a planetary gearbox. A comparison of two motion handling techniques in STARCCM+ namely MRF (Moving Reference Frame) and RBM (Rigid Body Motion) models is made in terms of the accuracy of results and the computational requirements using the FZG gearbox. A sensitivity analysis on how the size of gap between the meshing gear teeth affects the flow and the computational requirements is also done using the FZG gearbox. Different modelling alternatives are investigated for the planetary gearbox and the best choices have been determined. The numerical simulations are solved in an unsteady framework where the VOF (Volume Of Fluid) multiphase model is used to track the interface between the immiscible phases. The overset meshing technique has been used to reconfigure the mesh at each time step. The results from the CFD simulations are presented and discussed in terms of the modelling choices made and their effect on the accuracy of the results. The MRF method is a cheaper alternative compared to the RBM model however, the former model does not accurately simulate the transient start-up and instead provides just a regime solution of the unsteady problem. As expected, the accuracy of the results suffers from having a large gap between the meshing gear teeth. The use of compressible ideal gas model for the air phase with a pressure boundary condition gives the optimum performance for the planetary gearbox. The outcomes can be used toeffectively study transmission flows using CFD and thereby improve the design of future transmissions for improved efficiency.

ABSTRACT MICROARRAY APPLICATIONS FOR DETERMINATION OF THE EFFECTS OF EMODIN ON BREAST CANCER CELL LINES Ekenel Qomi, Emilia M.S., Department of Biotechnology Supervisor: Prof. Dr. Mesude Iscan Co-Supervisor: Assoc. Prof. Dr. Nursen &Ccedil<br>oruh February 2012, 191 pages Cancer is a genetic disease that is characterized by uncontrolled cells growth. Breast cancer is a type of cancer originating from breast tissue. Some breast cancers are sensitive to hormones such as estrogen which makes it possible to treat them by blocking the effects of these hormones in the target tissues. These require less aggressive treatment than hormone negative cancers. Breast cancers without hormone receptors, are higher-risk, and are treated more aggressively. The aim of our study is to investigate the effect of emodin on MCF-7 which is ER (estrogen receptor) positive, and MDA-MB-231 (ER negative) cancerous cell lines. Emodin which is a phytoestrogen component, extracted from rheum (genus) plant, has been reported to suppress the growth of tumor in some clinical situation, and it&rsquo<br>s found that emodin induced apoptosis through the decrease of Bcl-2/Bax ratio and the increase of cytoplasm cytochrome c concentration in human breast cancer Bcap-37 cells. Comparing the effect of emodin between ER positive and ER negative cells at the molecular level was investigated by Microarray analysis of gene expressions using Affymetrix Human Genome U133 plus 2.0 Array. The microarray data analysis was performed by using BRB-Array Tools, v.4.2.0. GST and its classes<br>Alpha, Mu, Pi, Theta, Sigma, Omega, Zeta and Kappa is our interested genes because of its role in regulating susceptibility to cancer, by their ability to metabolize reactive electrophilic intermediates to usually less reactive and more water soluble glutathione conjugates. And also its have a role in detoxifying the damage caused by oxidative stress which is a result of the radiotherapy. v The differentially expressed genes from emodin treated and untreated control breast cancer cell lines were compared after normalization and filtering and annotated, it was shown that the top 10 highly (significantly) varied genes belong to the biological processes such as (namely) cell cycle, cell division, cell proliferation, mitosis and meiosis, this insure the relation of emodin to the cell growth processes in the cancerous cells. The analysis of the change on the cell growth confirmed the anti-tumor effect of emodin. About the effect of emodin treatment on MCF-7 and MDA-MB-231 cancerous cell lines separately<br>Both cells its significant genes was belong to cell growth biological processes, in MCF-7 cells in-addition other biological processes was shown, for example<br>stimulus to estradoil response, and the metabolism of xenobiotic by cytochrome p450, so CYP1A1 gene code for a protein which is used in emodin metabolism. The varied gene number was nearly 4400 gene from the scatter plot result in MCF-7 cells while in MDA-MB-231 cells it was nearly 3400 gene, these result insured the effect of emodin as a phytoestrogenic component as MCF-7 cells are ER positive cells, so emodin bind to the ER in MCF-7 cells and affected more gene number than MDA-MB-231. More number of GST enzyme classes changed in MCF-7 cells than MDA-MB-231, and the effect of emodin as anti-cancer showed different change of GST genes between MCF-7 and MDA-MB-231. The results confirmed by network analysis done, to find the most related genes to our top 10 regulated gene list, and these genes were analyzed<br>most of them where in our gene list, and their regulation after emodin treatment analyzed and the result was supported to emodin as anti-tumor and phytoestrogenic component.

O comportamento do câncer de mama pode ser influenciado pela interação entre células tumorais e estromais que infiltram e circundam o tumor. Acredita-se também que as células que compõem o microambiente linfonodal possam influenciar o perfil da expressão gênica de células mamárias malignas MDA-MB231, induzindo ou inibindo o desenvolvimento de metástase regional. Para avaliar essa possibilidade, células MDA-MB231 foram co-cultivadas com fibroblastos obtidos de linfonodos comprometidos ou não comprometidos de pacientes com câncer de mama, separadas por membranas porosas por 72 horas. O perfil da expressão gênica foi avaliado através de uma plataforma de cDNA microarray de 4608 genes. Observamos que 155 e 188 genes foram modulados em células MDA-MB231 na presença de fibroblastos de linfonodos não comprometidos e comprometidos, respectivamente, quando comparados com células MDA-MB231 cultivadas isoladamente. Análise do agrupamento hierárquico não supervisionado utilizando os genes diferencialmente expressos revelou a presença de dois grupos, um constituído por células MDA-MB 231 em monocultura e outro por células mantidas em co-cultura com fibroblastos. Splicing de RNAm, via spliceossoma, ciclo celular e regulação da transcrição por promotores da RNA polimerase II, foram algumas funções moduladas em células MDA-MB231. A seguir novos ensaios de co-cultura foram realizados e a expressão de alguns genes foram analisados por RT-PCR. FN3K e COMT foram menos expressos em células MDA-MB231 na presença de fibroblastos de linfonodos, mas não em co-cultura com células MCF-7, nas quais apenas HTRA1 mostrou-se hipoexpresso em casos de co-cultura com fibroblastos. Esses resultados sugerem que a inter-relação entre células estromais e células tumorais são dependentes do subtipo do tumor, de fenótipo luminal ou basal<br>Breast cancer behavior may be influenced by interactions between cancer and stromal cells, which infiltrate and surround the tumor. It is also believed that cells within the lymph node microenvironment may influence the gene expression profile of breast cancer cells, stimulating or inhibiting regional metastasis development. To evaluate this possibility, breast cancer MDAMB231 cells were co-cultured with fibroblasts obtained from involved or uninvolved lymph nodes from breast cancer patients, using a porous membrane, for 72 hours. Gene expression profile was evaluated through a cDNA microarray platform containing 4608 genes. MDA-MB231 cells had 155 and 188 genes modulated by the presence of fibroblasts from uninvolved or involved nodes, respectively, as compared to MDA-MB231 cells cultured alone. Unsupervised hierarchical clustering using the differentially expressed genes revealed the presence of two groups, one comprising MDA-MB231 cells cultured aloned and another one, MDA-MB231 cells co-cultured with fibroblasts. Nuclear mRNA splicing, via spliceosome, cell cycle, and regulation of transcription from RNA polymerase II promoter, were functions regulated in cocultured MDA-MB231 cells. New co-culture assays were performed and expression of a few genes was further evaluated by RT-PCR. FN3K and COMT were both down-regulated in MDA-MB231 cells in the presence of nodes\' fibroblasts, but not in co-cultured MCF7 cells, while HTRA1 was just down regulated in MCF7 co-cultured cells. These results suggest that the interrelationship between stromal and cancer cells are dependent on the subtype of tumor, whether from luminal or basal-like phenotype

Au sein des opérations de retraitement du combustible usé, la colonne pulsée à garnissage est l'appareil d'extraction liquide-liquide principalement utilisé. Dans un contexte de compétitivité économique et de raréfaction des ressources, l'efficacité de ces appareils est devenue un enjeu pour l'industriel. Afin d'améliorer leur rendement à travers un meilleur dimensionnement, la connaissance de la vitesse de glissement entre les phases de l'émulsion est nécessaire.Les travaux menés et présentés dans ce manuscrit s'articulent autour de la modélisation physique et numérique de l'hydrodynamique de l'émulsion ainsi que de sa caractérisation expérimentale.Dans ce travail, une modélisation d'approche eulérienne, inspirée des travaux de D. Lhuillier, permet l'obtention d'un modèle bi-fluide couplé à une équation d'évolution de la surface d'échange (aire interfaciale). La résolution du modèle s'effectue par éléments finis sous le logiciel CAST3M. A l'issue des calculs, le modèle montre sa capacité à restituer le comportement de l'émulsion et permet l'obtention des vitesses de glissement. Dans une optique de validation expérimentale du modèle, des expérimentations sur deux installations sont menées. Celles-ci font notamment intervenir un couplage entre les méthodes de vélocimétrie par image de particules et de fluorescence induite par laser afin d'obtenir les vitesses de chaque phases et le taux de rétention de la phase dispersée. Un algorithme de détection et de suivi de gouttes est développé afin d'obtenir la vitesse de la phase dispersée et sa fraction volumique. La confrontation de ces aux résultats numériques permet une première qualification encourageante du modèle<br>In the core of spent fuel reprocessing operations, the pulsed columns with packing are the liquid-liquid extraction apparati mainly used. The context of economical competiveness and scarce resources, industrials are driven to improve the efficiency of these processes. Pulsed column efficiency is bound to the amount of available exchange surface, which depends on geometrical parameters of the column and the operating conditions. A better design would improve the efficiency. In this aim the knowledge of the interphase slip velocity is necessary. The work presented in this thesis revolves around physical and numerical modelling of the hydrodynamics of the emulsion and its experimental characterization.In this work, a eulerian approach, based on the work of D.Lhuillier, allows to obtain a two-fluid model coupled with an evolution equation of the exchange surface (interfacial area). We use finite elements method to solve this model along with CAST3M software. Numerical simulations have shown the model abilities to correctly reproduce the emulsion behaviour and to obtain the slip velocity.In order to experimentally validate the model, we carried out two types of experimentation. Particles images velocimetry coupled to laser induced fluorescence are involved to obtain velocities of each phases and the dispersed phase volume fraction. We developed a tracking algorithm to obtain the dispersed phase velocity and the hold up. These results, such as velocities and strain rate tensor, have been used in a first validation of the model

No<br>Optimal design and operation of MSF desalination process is considered here using MINLP technique within gPROMS model builder 2.3.4. gPROMS provides an easy and flexible platform to build a process flowsheet graphically and the corresponding master model connecting automatically individual unit model equations during simulation and optimisation. For different freshwater demand throughout the year and with seasonal variation of seawater temperature, the total annualised cost of desalination is minimised. It is found that seasonal variation in seawater temperature results in significant variation in design and some of the operating parameters but with minimum variation in of process temperatures. The results also reveal the possibility of designing stand-alone flash stages which would offer flexible scheduling in terms of the connection of various units (to build up the process) and efficient maintenance of the units throughout the year as the weather condition changes. In addition, operation at low temperatures throughout the year will reduce design and operating costs in terms of low temperature materials of construction and reduced amount of anti-scaling and anti-corrosion agents.

碩士<br>國立成功大學<br>微電子工程研究所碩博士班<br>92<br>In this thesis, the properties and characteristics investigation of nitride based multiple quantum wells light emitting diodes which had been fabricated by metal organic chemical vapor deposition were demonstrated. The simulation results using “MEDICI” of different barrier doping location and concentration were compared with experimental results. Furthermore, the parameters of quantum well such as barrier and well thickness and barrier doping condition were confirmed using x-ray diffraction, photoluminescence and electroluminescence. From the experiments, different doping location changes the forward voltage at 20mA (i.e. VF2) of LEDs. Then, barrier thickness of 215Å is determined with the best quantity in this structure due to better electron-hole recombination mechanism. Besides, the narrower well thickness shows better quantum confinement then contributes to LED luminescence. The well thickness is dominant in energy transition; hence different well thickness changes emitted light of LED. In addition, higher barrier doping concentration can lead to better crystal quality owing to the doped silicon make up for the defects. Further, the highest transparency of ITO film was obtained with 450°C annealing temperature and 1800 Å thickness separately. In summary, the studies of quantum well doping, thickness and pair were demonstrated to verify their characteristics, and simulations also show a considerable tool to design and determine to characteristic of optical devices.

No<br>Modelling played an important role in simulation, optimisation, and control of multi-stage flash (MSF) desalination processes. Top brine temperature (TBT) is one of the many important parameters that affect optimal design and operation of MSF processes. Within the MSF process model, calculation of TBT is therefore important. For a given pressure, TBT is a function of boiling point temperature (BPT) at zero salinity and temperature elevation (TE) due to salinity. In this work, we develop several neural network (NN) based correlations for predicting TE. It is found that the NN based correlations can predict the experimental TE very closely. Also predictions by the NN based correlations were good when TE values, obtained using existing correlations from the literature are compared. Due to advancement of the microcomputer, plant automation becomes reliable means of plant maintenance. NN based correlations (models) can be updated in terms of new sets of weights and biases for the same architecture or for a new architecture reliably with new plant data.

Synchronization is one of the important issues in digital system design. While other approaches have been intriguing, up until now a globally clocked timing discipline has been the dominant design philosophy. However, we have reached the point, with advances in technology, where other options should be given serious consideration. VLSI promises great processing power at low cost. This increase in computation power has been obtained by scaling the digital IC process. But as this scaling continues, it is doubtful that the advantages of faster devices can be fully exploited. This is because the clock periods are getting much smaller in relation to the interconnect propagation delays, even within a single chip and certainly at the board and backplane level. In this thesis, some alternative approaches to synchronization in digital system design are described and developed. We owe these techniques to a long history of effort in both digital computational system design as well as digital communication system design. The latter field is relevant because large propagation delays have always been a dominant consideration in its design methods. Asynchronous design gives better performance than comparable synchronous design in situations for which a global synchronization with a high speed clock becomes a constraint for greater system throughput. Asynchronous circuits with unbounded gate delays, or self-timed digital circuit can be designed by employing either of two request-acknowledge protocols 4-cycle and 2-cycle. We will also present an alternative approach to the problem of mapping computation algorithms directly into asynchronous circuits. Data flow graph or language is used to describe the computation algorithms. The data flow primitives have been designed using both the 2-cycle and 4-cycle signaling schemes which are compared in terms of performance and transistor count. The 2-cycle implementations prove to be better than their 4-cycle counterparts. A promising application of self-timed design is in high performance DSP systems. Since there is no global constraint of clock distribution, localized forwardonly connection allows computation to be extended and sped up using pipelining. A decimation filter was designed and simulated to check the system level performance of the two protocols. Simulations were carried out using VHDL for high level definition of the design. The simulation results will demonstrate not only the efficacy of our synthesis procedure but also the improved efficiency of the 2-cycle scheme over the 4- cycle scheme.<br>Graduation date: 1994

In the present thesis, a novel gridding technique, as well as, two new segmentation methods applied to complementary DNA (cDNA) microarray images is proposed. More precise, a new gridding method based on continuous wavelet transform (CWT) was performed. Line profiles of x and y axis were calculated, resulting to 2 different signals. These signals were independently processed by means of CWT at 15 different levels, using daubechies 4 mother wavelet. A summation, point by point, was performed on the processed signals, in order to suppress noise and enhance spot’s differences. Additionally, a wavelet based hard thresholding filter was applied to each signal for the task of alleviating the noise of the signals. 10 real microarray images were used in order to visually assess the performance of our gridding method. Each microarray image contained 4 sub-arrays, each sub-array 40x40 spots, thus, 6400 spots totally. According to our results, the accuracy of our algorithm was 98% in all 10 images and in all spots. Additionally, processing time was less than 3 sec on a 1024×1024×16 microarray image, rendering the method a promising technique for an efficient and fully automatic gridding processing. Following the gridding process, the Gaussian Mixture Model (GMM) and the Fuzzy GMM algorithms were applied to each cell, with the purpose of discriminating foreground from background. In addition, markov random field (MRF), as well as, a proposed wavelet based MRF model (SMRF) were implemented. The segmentation abilities of all the algorithms were evaluated by means of the segmentation matching factor (SMF), the Coefficient of Determination (r2), and the concordance correlation (pc). Indirect accuracy performances were also tested on the experimental images by means of the Mean Absolute Error (MAE) and the Coefficient of Variation (CV). In the latter case, SPOT and SCANALYZE software results were also tested. In the former case, SMRF attained the best SMF, r2, and pc (92.66%, 0.923, and 0.88, respectively) scores, whereas, in the latter case scored MAE and CV, 497 and 0.88, respectively. The results and support the performance superiority of the SMRF algorithm in segmenting cDNA images.<br>Τα τελευταία χρόνια παρατηρείται ραγδαία ανάπτυξη της τεχνολογίας των μικροσυστοιχιών (microarrays) με αποτέλεσμα την ποιοτική και ποσοτική μέτρηση της έκφρασης χιλιάδων γονιδίων ταυτοχρόνως σ’ ένα και μόνο πείραμα. Εικόνες μικροσυστοιχιών, στις οποίες έχει λάβει χώρα υβριδοποίηση δείγματος DNA, χρησιμοποιούνται ευρέως για την εξαγωγή αξιόπιστων αποτελεσμάτων γονιδιακής έκφρασης και προσδιορισμό των μηχανισμών που ελέγχουν την ενεργοποίηση των γονιδίων σ’ έναν οργανισμό. Συνεπώς, η δημιουργία κατάλληλων υπολογιστικών τεχνικών για την επεξεργασία των εικόνων αυτών συντελεί καθοριστικά στην εξαγωγή ορθών και έγκυρων αποτελεσμάτων. Στη παρούσα Διδακτορική Διατριβή αναπτύχθηκε στο πρώτο στάδια μια νέα πλήρως αυτοματοποιημένη τεχνική διευθυνσιοδότησης και στο δεύτερο στάδιο δύο νέες τεχνικές τμηματοποίησης. Πιο συγκεκριμένα, αναπτύχθηκε μια νέα μέθοδος διευθυνσιοδότησης η οποία βασίζεται στο συνεχή μετασχηματισμό κυματιδίου (Continuous Wavelet Transform CWT) για την αυτόματη εύρεση των κέντρων των κηλίδων, καθώς και των ορίων μεταξύ δύο διαδοχικών κηλίδων. Στη συνέχεια αναπτύχθηκαν δύο νέες μέθοδοι κατάτμησης της εικόνας για τον διαχωρισμό των κηλίδων από το φόντο, οι οποίες βασίζονται στη τεχνική μίξης ασαφών μοντέλων Γκάους (Fuzzy Gaussian Mixture Models FGMM) καθώς και στη τεχνική συνδυασμού τυχαίων πεδίων Μαρκόφ (Markov Random Field MRF) και μετασχηματισμού κυματιδίου (Wavelet Transform WT) (SMRF). Με σκοπό την αξιολόγηση (validation) των προτεινόμενων μεθόδων της παρούσας Διδακτορικής Διατριβής, δημιουργήθηκαν και χρησιμοποιήθηκαν τόσο πραγματικές εικόνες μικροσυστοιχιών, καθώς και απομιμούμενες (simulated) σύμφωνα με μεθοδολογία η οποία προτείνεται απο τη διεθνή βιβλιογραφία. Όσον αφορά την διευθυνσιοδότηση, χρησιμοποιώντας οπτική ανασκόπηση για κάθε κηλίδα χωριστά σε όλες τις πραγματικές εικόνες, δημιουργήθηκαν δύο κατηγορίες, ανάλογα με το αν οι γραμμές του πλέγματος εφάπτονταν πάνω σε κάποια κηλίδα ή όχι. Η προτεινόμενη μεθοδολογία ήταν ακριβής σε ποσοστό 98% στον ακριβή εντοπισμό των κηλίδων σε όλες τις εικόνες. Σύγκριση ανάμεσα στην απόδοση των GMM, FGMM, MRF και SMRF στις απομιμούμενες εικόνες σε διαφορετικά επίπεδα θορύβου πραγματοποιήθηκε και τα αποτελέσματα σε όλα τα μετρικά, segmentation matching factor (SMF), coefficient of variation ( ), και coefficient of determination ( ), μας έδειξαν ότι η μέθοδος SMRF είναι πιο αξιόπιστη στο να μπορέσει να αναδείξει την πραγματική περιφέρεια της κηλίδας, τόσο σε εικόνες με μεγάλο λόγο σήματος προς θόρυβο, όσο και σε μικρό λόγο. Ενδεικτικά αποτελέσματα σε 1 db SNR για την περίπτωση του SMRF είναι SMF = 92.66, =0.923, και = 0.88, ακολουθούμενο από το MRF ( SMF = 92.15, =0.91, και = 0.85), FGMM ( SMF = 91.07, =0.92, και = 0.86)και GMM (SMF = 90.73, =0.89, και = 0.83). Στη συνέχεια πάρθηκαν αποτελέσματα τα οποία προέκυψαν από τη χρήση πραγματικών εικόνων μικροσυστοιχιών. Και σε αυτή τη περίπτωση, αναδείχθηκε η υπεροχή του WMRF, έναντι των άλλων αλγορίθμων ταξινόμησης μέση τιμή MAE = 497 και CV = 0.88. Τέλος, θα πρέπει να τονιστεί ότι τα παραπάνω μετρικά υπολογίστηκαν και σε αποτελέσματα από δύο ευρέως χρησιμοποιούμενα πακέτα επεξεργασίας εικόνων μικροσυστοιχιών, τα οποία χρησιμοποιούνται και είναι διαθέσιμα. Πιο συγκεκριμένα, χρησιμοποιήθηκαν το SCANALYSE και το SPOT, τα οποία χρησιμοποιούν τις τεχνικές τμηματοποίησης Fixed Circle και Seeded Region Growing, αντίστοιχα. Στη περίπτωση αυτή η τεχνική SMRF κατάφερε να υπολογίσει καλύτερα αποτελέσματα από τα δύο αυτά πακέτα. Πιο συγκεκριμένα η τεχνική GMM πέτυχε MAE = 1470 και CV = 1.29, η τεχνική FGMM πέτυχε MAE = 1430 και CV = 1.21, η τεχνική MRF πέτυχε MAE = 1215 και CV = 1.15, η τεχνική WMRF πέτυχε MAE = 497 και CV = 0.88, η τεχνική FC του λογισμικού πακέτου SCANALYZE πέτυχε MAE = 503 και CV = 0.90, και τέλος η τεχνική SRG του λογισμικού πακέτου SPOT πέτυχε MAE = 1180 και CV = 0.93.

博士<br>臺北醫學大學<br>醫學科學研究所<br>103<br>Neurophilic parasitic infections (like Toxocariasis and Toxoplasmosis) and intestinal parasites are serious public health problems in many developed and developing countries. Children are particularly at risk due to their attraction to pets (especially dogs and cats), their play habits, poor level of hygiene and in some cases pica. In Nigeria many studies have indicated the existence of Toxocara canis in dogs, but investigations in humans is very scanty and none exist exclusively on children, and in southern Nigeria. With regards to Toxoplasmosis, most of the studies, if not all, in the country are on pregnant women. Hence, there is also paucity of information on the prevalence in children. Intestinal parasitic infections continue to prevail in Nigeria, hence the need for accurate diagnosis. Most studies in the country were done using the Kato-Katz, probably due to cheaper cost, though the technique is believed to be less sensitive compared to the Merthiolate-Iodine-Formaldehyde (MIF) technique. Blood samples were collected (3-5mls) for the detection of both Toxocara canis and Toxoplasma gondii. The larval excretory-secretory antigens, from the third stage larva, were used to test sera for toxocara specific IgG by western blotting. A kit based on latex agglutination (Toxo Test-MT: Eiken Tokyo) was used to test sera for T. gondii and a titre of 1:32 or higher was considered positive. Intestinal helminthes were investigated using stool samples. About 1g of stool sample was put in special containers for the MIF procedure and mixed with 5mls of MIF solution, then passed through a 100 mesh sieve. It was then allowed to stand overnight after which about 50ul was aspirated onto microscope slides and viewed. For the Kato-Katz technique, about 1g of stool was also used. The stool was placed on a filter paper and pressed through a 100 mesh sieve. The sieved stool was then scraped off the sieve surface and placed to fill a hole on a template on a microscope slide. The fecal material was then covered with pre-soaked cellophane strips in malachite green, inverted and pressed for an even spread, then viewed. Out of the 384 samples (blood and stool) examined, results showed that 86.1%, 24% and 86.2% of the children were infected with Toxocara canis, Toxoplasma gondii and intestinal parasites respectively. The MIF technique showed superiority to Kato-Katz in detection of intestinal parasites (p < 0.0001), and it was also able to detect protozoan parasites like Entamoeba hystolytica/E. dispar (27%), Entamoeba coli (10%), Giardia lamblia (13%), Endolimax nana (11%) and Blastocystis hominis (3%), which were not detected by Kata-Katz. With the results of Toxocariasis and Toxoplasmosis infections, we have generated baseline data on these neglected tropical diseases among schoolchildren in Nigeria, while enriching the data on intestinal parasitic infections. There is therefore need for community education on personal hygiene, proper sanitation, and drinking of safe water. Government intervention in these aspects is also urgently required.

This thesis describes the development, modification and refinement of a high-powered hybrid Stratospheric Tropospheric (ST)/meteor radar at the University of Adelaide’s Buckland Park (BP) field station. This thesis also describes the process of statistically comparing results obtained from multiple co-located independent measurement sources. Also included are statistical comparisons made between meteor radars at BP,Darwin, Northern Territory, and Davis Station, Antarctica, with other independent sources of measurement. Previous meteor radar systems have generally been low powered (∼8 kW peak) and as such could only afford low count rates at frequencies of the order of 50 MHz. While it has been shown that the echo detection rate is inversely proportional to frequency to the power of 1.5, the use of lower VHF frequencies within Australia is restricted by government regulations. As such, this has lead to the development of a high powered meteor radar system at 55 MHz which has served to facilitate higher echo rates at this frequency. The aim of improving the echo rate is to improve the statistical accuracy of results generated by the meteor technique. Also presented are descriptions of the meteor radar systems used to provide the data for this study and the basic principles of the meteor technique. Basic descriptions of the other systems and the techniques used to provide data for comparison are also presented. Two key components in the development of the high-powered meteor system are the high-powered all-sky crossed-dipole transmit antenna and the high-powered 1:2 splitter-combiner required to drive the antenna. The antenna was designed using standard equations for Yagi-Uda antenna design found in literature and modeled using the EZNEC modeling programe. After successful modeling, the antenna was prototyped and refined into a low powered version to investigate the antenna’s performance characteristics. Once the performance of the antenna was verified, the process of upgrading the antenna to handle the full output power from a VTX transmitter was performed. This upgrade also spawned the design and development of the highpowered 1:2 splitter-combiner which would be used to feed the high-powered version of the antenna. The successful operation of the high-powered system over several periods of observation has allowed for a more in-depth investigation into the statistical reliability of the meteor technique. Along with the comparison of standard atmospheric parameters, i.e. temperatures and wind velocity, the high-powered system has allowed for the verification of the relationship between echo rate and radar parameters found by McKinley, which is frequently referred to in many papers dealing with meteor observations. Along with the comparisons made with the results from the high-powered meteor radar system at BP, comparisons of atmospheric parameters derived from meteor observations and other techniques were made at Davis Station and Darwin. Of particular interest is the unique comparison of atmospheric winds made at Davis between two independent meteor radar systems and a Medium Frequency (MF) radar. Previous comparison studies have only enjoyed the benefit of having two independent sources of measurement to compare and as such have not allowed for a unique solution to be obtained for the uncertainties of the techniques using the method of Hocking et al. [2001]. Davis Station is unique in that it has two independent meteor radars in addition to a MF radar. This has enabled for the reduction in the number of degrees of freedom in the statistical comparison process, and as such has allowed for unique solutions to be determined for the uncertainties when comparing two independent techniques; i.e. meteor and MF wind comparisons. Atmospheric temperatures in the Mesospheric and Lower Thermospheric (MLT) region were determined through the use of meteor diffusion coefficients and derived atmospheric pressure models at Davis Station, BP and Darwin. Comparisons are made between the meteor technique and other co-located independent measurements. These include; airglow, satellite and falling sphere measurements at Davis Station, airglow and two independent satellite measurements at BP and two independent satellite observations at Darwin. This thesis as a whole demonstrates the successful operation of the highpowered ST/meteor hybrid radar at BP. It also demonstrates the successful comparisons of MLT winds and temperatures made between meteor radar and other independent sources of MLT measurements. The validation of using the high-powered meteor radar at BP coupled with the successful comparison of atmospheric parameters derived using the meteor technique and other forms of MLT observations serves to re-affirm the statistical accuracy and benefit of the meteor technique in observations of the MLT region.<br>http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1474902<br>Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2010

Yes<br>The NAD(+)-dependent deacetylase SIRT1 is involved in diverse cellular processes, and has also been linked with multiple disease states. Among these, SIRT1 expression negatively correlates with cancer survival in both laboratory and clinical studies. Active regulator of SIRT1 (AROS) was the first reported post-transcriptional regulator of SIRT1 activity, enhancing SIRT1-mediated deacetylation and downregulation of the SIRT1 target p53. However, little is known regarding the role of AROS in regulation of SIRT1 during disease. Here, we report the cellular and molecular effects of RNAi-mediated AROS suppression, comparing this with the role of SIRT1 in a panel of human cell lines of both cancerous and non-cancerous origins. Unexpectedly, AROS is found to vary in its modulation of p53 acetylation according to cell context. AROS suppresses p53 acetylation only following the application of cell damaging stress, whereas SIRT1 suppresses p53 under all conditions analysed. This supplements the original characterization of AROS but indicates that SIRT1 activity can persist following suppression of AROS. We also demonstrate that knockdown of AROS induces apoptosis in three cancer cell lines, independent of p53 activation. Importantly, AROS is not required for the viability of three non-cancer cell lines indicating a putative role for AROS in specifically promoting cancer cell survival.