Dissertations / Theses on the topic 'Function'

Thesis (MComm)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: In this dissertation I investigate the class number one problem in function fields. More precisely I give a survey of the current state of research into extensions of a rational function field over a finite field with principal ring of integers. I focus particularly on the quadratic case and throughout draw analogies and motivations from the classical number field situation. It was the "Prince of Mathematicians" C.F. Gauss who first undertook an in depth study of quadratic extensions of the rational numbers and the corresponding rings of integers. More recently however work has been done in the situation of function fields in which the arithmetic is very similar. I begin with an introduction into the arithmetic in function fields over a finite field and prove the analogies of many of the classical results. I then proceed to demonstrate how the algebra and arithmetic in function fields can be interpreted geometrically in terms of curves and introduce the associated geometric language. After presenting some conjectures, I proceed to give a survey of known results in the situation of quadratic function fields. I present also a few results of my own in this section. Lastly I state some recent results regarding arbitrary extensions of a rational function field with principal ring of integers and give some heuristic results regarding class groups in function fields.
AFRIKAANSE OPSOMMING: In hierdie tesis ondersoek ek die klasgetal een probleem in funksieliggame. Meer spesifiek ondersoek ek die huidige staat van navorsing aangaande uitbreidings van 'n rasionale funksieliggaam oor 'n eindige liggaam sodat die ring van heelgetalle 'n hoofidealgebied is. Ek kyk in besonder na die kwadratiese geval, en deurgaans verwys ek na die analoog in die klassieke getalleliggaam situasie. Dit was die beroemde wiskundige C.F. Gauss wat eerste kwadratiese uitbreidings van die rasionale getalle en die ooreenstemende ring van heelgetalle in diepte ondersoek het. Onlangs het wiskundiges hierdie probleme ook ondersoek in die situasie van funksieliggame oor 'n eindige liggaam waar die algebraïese struktuur baie soortgelyk is. Ek begin met 'n inleiding tot die rekenkunde in funksieliggame oor 'n eindige liggaam en bewys die analogie van baie van die klassieke resultate. Dan verduidelik ek hoe die algebra in funksieliggame geometries beskou kan word in terme van kurwes en gee 'n kort inleiding tot die geometriese taal. Nadat ek 'n paar vermoedes bespreek, gee ek 'n oorsig van wat alreeds vir quadratiese funksieliggame bewys is. In hierdie afdeling word 'n paar resultate van my eie ook bewys. Dan vermeld ek 'n paar resultate aangaande algemene uitbreidings van 'n rasionale funksieliggaam oor 'n eindige liggaam waar die van ring heelgetalle 'n hoofidealgebied is. Laastens verwys ek na 'n paar heurisitiese resultate aangaande klasgroepe in funksieliggame.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Based on the theory of orthogonality, two orthogonal multiplex systems called frequency division multiplexing (FDM) and time division multiplexing (TDM) have long been developed. Therefore, many people tend to think that these two systems represent the ONLY two multiplexing methods that satisfy the orthogonal condition. However, after years of research, we've discovered a new kind of orthogonal functions called Bridge functions. The Bridge functions have the every promise of being the basis for constructing an entirely new kind of telemetry system, which has been named as sequency division multiplexing (SDM). Since the Bridge functions are the mathematical basis of the new telemetry system, we will give a summary of the Bridge functions at first. We have successfully constructed an experimental prototype called BAM-FM system in our laboratory. The main ideas, block diagram, operational principles, and technical problems are discussed in this paper. All our work has proved that SDM has not only research interests, but also practical value.

Medical research currently involves the collection of large and complex data. One such type of data is functional data where the unit of measurement is a curve measured over a grid. Functional data comes in a variety of forms depending on the nature of the research. Novel methodologies are required to accommodate this growing volume of functional data alongside new testing procedures to provide valid inferences. In this dissertation, I propose three novel methods to accommodate a variety of questions involving functional data of multiple forms. I consider three novel methods: (1) a function-on-function regression for Gaussian data; (2) a historical functional linear models for repeated measures; and (3) a generalized functional outcome regression for ordinal data. For each method, I discuss the existing shortcomings of the literature and demonstrate how my method fills those gaps. The abilities of each method are demonstrated via simulation and data application.

Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Mavris, Dimitri; Committee Member: Garcia, Elena; Committee Member: Soban, Danielle. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 19, 2008) Includes bibliographical references.

It is an important problem in analytic number theory to estimate mean values of the Riemann zeta-function and other L-functions. The study of moments of L-functions has some important applications, such as to give information about the maximal order of the Riemann zeta-function on the critical line, the Lindelof Hypothesis for L-functions and non-vanishing results. Furthermore, according to the Katz-Sarnak philosophy [Katz-Sar99a, Katz-Sar99b] it is believed that the understanding of mean values of different families of L-functions may reveal the symmetry of such families. The analogy between characteristic polynomials of random matrices and L- functions was first studied by Keating and Snaith [Kea-SnaOOa, Kea-SnaOOb]. For example, they were able to conjecture asymptotic formulae for the moments of L- functions in different families. The purpose of this thesis is to study moments of L-functions over function fields, since in this case the L-functions satisfy a Riemann Hypothesis and one may give a spectral interpretation for such L-functions as the characteristic polynomial of a unitary matrix. Thus, we expect that the analogy between characteristic polynomials and L-functions can be further understood in this scenario. In this thesis, we study power moments of a family of L-functions associated with hyperelliptic curves of genus 9 over a fixed finite field lFq in the limit as g-->∞, which is the opposite limit considered by the programme of Katz and Sarnak. Specifically, we compute some average value theorems of L-functions of curves and we extend to the function field setting the heuristic for integral moments and ratios of L-functions previously developed by Conrey et. al [CFKRS05, Conr-Far-Zir] for the number field case.

Symbiotic nitrogen fixation occurs in plants harboring nitrogen-fixing bacteria within the plant tissue. The most widely studied association is between the legumes and rhizobia. In this relationship the plant (legumes) provides the bacteria (rhizobia) with reduced carbon derived from photosynthesis in exchange for reduced atmospheric nitrogen. This allows the plant to survive in soil, which is low in available of nitrogen. Rhizobia infect and enter plant root and reside in organs known as nodules. In the nodules the bacteria fix atmospheric nitrogen. The association between the legume, Medicago truncatula and the bacteria Sinorhizobium meliloti, has been studied in detail. Medicago mutants that have defects in nodulation help us understand the process of nitrogen fixation better. One such mutant is the Mtnip-1. Mtnip-1 plants respond to S. meliloti by producing abnormal nodules in which numerous aberrant infection threads are produced, with very rare rhizobial release into host plant cells. The mutant plant Mtnip-1 has an abnormal defense-like response in root nodules as well as defects in lateral root development. Three alleles of the Mtnip/latd mutants, Mtnip-1, Mtlatd and Mtnip-3 show different degrees of severity in their phenotype. Phylogenetic analysis showed that MtNIP/LATD encodes a protein belonging to the NRT1(PTR) family of nitrate, peptide, dicarboxylate and phytohprmone transporters. Experiments with Mtnip/latd mutants demonstrats a defective nitrate response associated with low (250 μM) external nitrate concentration rather than high (5 mM) nitrate concentration. This suggests that the mutants have defective nitrate transport. To test if MtNIP/LATD was a nitrate transporter, Xenopus laevis oocytes and Arabidopsis thaliana mutant plants Atchl1-5, defective in a major nitrate transporter AtNRT1.1(CHL1), were used as surrogate expression systems. Heterologous expression of MtNIP/LATD in X. laevis oocytes and Atchl1-5 mutant plants conferred on them the ability to take up nitrate from external media with high affinity, thus demonstrating that MtNIP/LATD was a high affinity nitrate transporter. Km for MtNIP/LATD was determined to be approximately160 μM in the X. laevis system and 113 μM in the Arabidopsis Atchl1-5 mutant lines thus supporting the previous observation of MtNIP/LATD being a high affinity nitrate transporter. X. laevis expressing the mutant Mtnip-1 and Mtlatd, were unable to transport nitrate. However X. laevis oocytes, expressing the less severe mutant allele Mtnip-3 were able to transport nitrate suggesting another role of the Mtnip/latd besides high affinity nitrate transport. Experimental evidence suggested that MtNIP/LATD might transport another substrate beside nitrate. MtNIP/LATD levels are regulated by phytohormones. Experiments performed with ABA (abscisic acid), IAA (indole acetic acid) and histidine as substrates in X. laevis system show that the MtNIP/LATD mRNA injected oocytes efflux IAA but do not transport histidine or ABA. When wild type A17 and mutant Mtnip-1 and Mtnip-3 plants, grown in the presence of different sources of nitrogen were screened in herbicide chlorate, a structural analog of nitrate, the A17 and Mtnip-3 mutant showed levels of susceptibility that was different from mutant Mtnip-1 lines. Evidence suggested that the amount of chlorate transported into the plants were regulated by the C:N status of the A17 and Mtnip-3 plants. This regulation was missing in the Mtnip-1 lines thus suggesting a sensor function of MtNIP/LATD gene.

In 1997, Congress established the Individuals with Disabilities Education Act (IDEA, 1997), which required that schools conduct functional behavior assessments when a student engages in problem behavior that may lead to suspension or expulsion (Ervin et al., 2001; Yell & Katsiyanis, 2010). As a result, research has expanded to include ways to adapt the functional assessment process in school settings. The purpose of this study was to compare the correspondence between functional analysis procedures for students in a private school and validate the assessment outcomes with interventions conducted in the classroom settings. The results indicate that both assessments corresponded in 87% of all functions identified in the study. Furthermore, the interventions yielded reductions in problem behaviors for all participants.

This dissertation follows the history of functional ideas and their pedagogy, illuminates with many examples the implementation of my updated system of Functional Analysis, and discusses the pedagogical implications that this updated system implies. The main goal is to update a system of labeling to be as pedagogically friendly as possible, in order to assist students and teachers of harmony to more easily and enjoyably learn, teach, and engage with common-practice tonal harmonic practice. Example syllabi, assignments, classroom demonstrations, and long projects are also included, and each aspect of the labeling is carefully discussed as it is presented. By surveying the history of functional thinking in music theory, we find that desire to analyze for function is not a new idea, and has been a goal of many theorists and harmony teachers for centuries. However, the current methods for instructing in function still leave students confused or baffled, as they struggle to match functional concepts to labels that do not exemplify their analysis goals and methods that insist on starting from tiny detail instead of coming from a more complete musical perspective. The elaboration of each detail of my Functional Analysis system shows how each part of Functional Analysis has been designed to help make harmonic analysis quicker, easier, more intuitive, and more personalized. The greater pedagogical implications on a larger scale involving courses and curricula are also covered, informed by my experience both as a teacher of today’s standard system and from teaching Functional Analysis in the classroom.

Architects tend to organise a building in a most unnatural way. The organisation and formation of space is a complex matter which traditional approaches tend to flatten into something quantifiable, to allow the task to be managed and planned. This process is inherently determined by the way we perceive the world spatially; constituting a model defining the conceptualisation of space, which is implicit to the way an architect conceives and approaches the task of organising a building. This thesis argues that space is produced through activity. A product of interaction, patterns are determined through feedback between the state of an entity and its interpretation of its context. These patterns restrict autonomy, effecting constraints which enable organisation. In this way space is perceived productive: created through action and being, whilst at the same time creative through constraints effecting the constituents of an arrangement. The study explores a decentralised approach to configuring space, drawing on the concepts of self-organisation and emergence to reapproach how architectural space is organised. A series of models are presented, exploring how the authority of traditional methods may be transferred to the components of a system. An interdisciplinary piece of work, this explorative study draws on fields such as artificial life, qualitative reasoning, and biosemiotics to define an approach to configuring space which embraces the autonomy of natural systems. Using the computer as a tool to emulate natural phenomena, the food foraging behaviour of ant colonies and the aggregative behaviour of slime moulds are looked at as models of organisation; these are leveraged and steered to generate spatial formation. The thesis concludes with a model, conceived a body of swarms, that demonstrates a qualitative-semiotic conception of spatial configuration; alongside an appraisal of how the relations between components of a system might emerge in a creative process of production.

Hypertension is an important modifiable risk factor for cardiovascular disease. An important recent advancement in hypertension research is an understanding that hypertension often may have a developmental origin. Birthweight is associated with hypertension across the lifespan and adult cardiovascular disease, such that those at both ends of the spectrum are at increased risk. Nonetheless, birthweight is a crude surrogate of fetal growth and it may be that quantification of body composition, may more accurately identify the “at risk” individual. A causative mechanism linking birthweight and cardiovascular risk is yet to be identified but may involve changes to the structure and function of organs including the placenta which may impair development and predispose individuals to later cardiovascular disease. The aims of this thesis were to investigate the associations between placental function, body composition and cardiovascular autonomic function. Studies outlines in this thesis indicate different mechanism control fat mass and fat free mass in the newborn and that placental weight partly mediates the association of maternal factors with newborn body composition. While low birthweight has previously been shown to be associated altered autonomic function in the infant our studies suggests that body fatness may provide information beyond that obtained from birthweight assessment alone. Previous studies have shown altered blood pressure control in those born preterm, our studies found altered cardiovascular outcomes even in the late preterm newborn. Assessment of body composition in children and adolescents at rest and in response to an exercise test suggests worsening of autonomic control due to adiposity and may develop over time during childhood and adolescence. Collectively, these results emphasise the implications of altered in-utero and early life exposures on cardiovascular outcomes.

In mathematics, analytic number theory is a branch of number theory that uses methods from mathematical analysis to solve problems that concern the integers. It is often said to have begun with Dirichlet's introduction of Dirichlet L-functions. In analytic number theory one of the main investigation objects is the Riemann zeta function. The Riemann hypothesis states that all non-trivial zeros of the Riemann zeta function lie on the critical line. In the thesis we investigate value distribution of the Riemann zeta function on the critical line. To do so we use the curve of the Riemann zeta function on the critical line. A problem connected to the curve asks the question whether the curve is dense in the complex plane. We prove that the curve expands to all directions on the complex plane. A separete case of the main result can be stated as follows Riemann zeta function has infinetly many negative values on the critical line and they are unbounded.
Analizinė skaičių teorija yra skaičių teorijos dalis, kuri, naudodama matematinės analizės ir kompleksinio kintamojo funkcijų tyrimo metodus, sprendžia uždavinius susijusius su sveikaisiais skaičiais. Manoma, kad analizinės skaičių teorijos pradžią žymi Dirichlet eilučių ir Dirichlet L-funkcijų taikymai. Vienas iš pagrindinių analizinės skaičių teorijos tyrimo objektų yra Riemann’o dzeta funkcija. Riemann’o hipotezė teigia, kad visi netrivialieji nuliai yra ant kritinės tiesės. Disertacijoje nagrinėjamas Riemann’o dzeta funckijos reikšmių pasiskirstymas ant kritinės tiesės. Tam pasitelkiama Riemann’o dzeta funkcijos kreivė. Svarbus klausimas susijęs su kreive yra ar ši kreivė yra visur tiršta kompleksinių skaičių plokštumoje. Disertacijoje įrodoma, kad kreivė plečiasi į visas puse kompleksinių skaičių plokštumoje. Atskiras disertacijos pagrindinio rezultato atvejis gali būti formuluojamas taip – Riemann’o dzeta funkcija ant kritinės tiesės įgyja be galo daug neigiamų reikšmių, kurios yra neaprėžtos.

Code comprehension is by many considered to be one of the most expensive and time-consuming phases of the software life cycle. There are multiple techniques for making code more comprehensible, one of them alleged to be keeping functions small. However, the claim that small functions are superior to large functions with regards to code comprehension, are often based upon programming experience and stated without references from research. In these claims the importance of intention-revealing function names to improve codecomprehension is also emphasized. It could therefore be questioned whetherit is keeping functions small or the enabling of intention-revealing functionn ames that underlies the claim of superiority of small functions. This thesis presents previous studies and relevant literature within the area as well as carries out tests using eye tracking. The results of the tests indicated that intention-revealing function names have a significant effect on how fast developers comprehend code. It is also indicated that simply splitting up a function, without using intention-revealing function names, increases the chance for programmers to be able to tell the correct output. To be able to draw reliable conclusions, further studies would be necessary, where the most important improvements would be to provide an unlimited amount of time for each test as well as a larger quantity of test persons.
Kodförståelse anses enligt många vara en av de mest tidskrävande faserna i en programvaras livscykel. Det finns flera tekniker för att göra kod mer begriplig, som till exempel att hålla funktioner korta. Påståendet att korta funktioner är överlägsna långa funktioner med avseende på kodförståelse, är ofta baserat på erfarenhet inom programmering och inte grundat i forskning. I dessa påståenden betonas även vikten av att använda intentionsavslöjande funktionsnamn för att främja kodförståelse. Man kan därför fråga sig om det är själva funktionslängden eller möjligheten att använda intentionsavslöjande namn som ligger bakom påståendet att korta funktioner är fördelaktiga. Denna rapport tar upp tidigare studier och relevant litteratur inom området, samt presenterar resultat från tester menade att undersöka denna fråga. Resultaten från testerna pekar på att intentionsavslöjande funktionsnamn har en signifikant betydelse för hur snabbt utvecklare begriper kod. Det finns även en antydan till att endast dela upp en funktion, utan att använda intentionsavslöjande funktionsnamn, ökar sannolikheten att en programmerare förstår vad funktionen gör. För att kunna dra säkra slutsatser bör ytterligare studier genomföras, där testerna utförs utan tidsbegränsning och på fler testpersoner än i denna studie.

Every architect’s work is a set of conditions which, through various relations, may add frequently does have a significant influence on all who participate in the built environment. At the same time, both architects and their work are constantly exposed to various changing relations. When one considers the network of those mutual influences of which an architect and his environment are elements, “form” may be seen as the positioning of an object within a network of conditions and their relations. This network includes visual characteristics of an object, imposed by the architect, and those independent of him, which are culturally conditioned. Such a network constitutes what is understood by “form” in this project. Among visual relations, I have chosen to recognize for example rhythm, contrast, balance, proportions and transparency. The culturally implied (given) relations are, for example, ownership, use, tradition, fashion. All these relations, imposed by an architect and implied by a culture, reveal only a small fraction of this relational network, of which I have consciously chosen to consider only a few. Within this framework, the term “function” would describe a momentary suspension of the dynamics of the network of relations. It is called momentary because all of the elements are in contrast change. Consequently, so are their relations with other elements and, therefore, the overall aspect of the form. Function allows the “freezing” of the network in order to make the observation and critique of the object possible. Such observation can be performed only within certain imposed boundaries, since the entire framework, and consequently, both form and function, are limitless in their nature. Those boundaries reveal certain aspects of the object which are constituted from groups of considerations, which in this project are called “conditions”. Some of the “conditions” are later mentioned in the book a plan, elevation, shape. Since all of them resemble each other in their tendency towards balance, different parts of the project perform in a similar way.
Master of Architecture

O projeto de funções de transferência é um interessante problema que recebe muita atenção da comunidade de visualização. Diversas pesquisas tem sido conduzidas para criar melhores ferramentas e técnicas que trabalham com dados volumétricos. Existem duas grandes classes de dados: volumes estruturados e volumes não-estruturados. A maioria dos trabalhos anteriores apenas se refere a dados estruturados. Este trabalho possui dois grupos de contribuições. O primeiro diz respeito ao problema clássico de especificação de funções de transferência. Primeiramente é desenvolvido o conceito de Ensembles, que são funções de transferência desenvolvidas a partir da combinação de funções anteriores e mais simples. Também é apresentada uma abordagem de key-framing para manipular dados que variam no tempo. O segundo grupo de contribuições é um estudo aprofundado sobre o comportamento de dados não-estruturados. Problemas críticos foram descobertos e tratados para permitir uma integração quase perfeita de ferramentas usadas para dados estruturados em dados não-estruturados. Os resultados mostram a melhoria de qualidade de histogramas, e também o sistema de desenvolvimento de funções de transferência. Trabalhos futuros são sugeridos para utilizar a versão melhorada do histograma de gradiente-magnitude, assim como a exploração de novos modelos de bordas.
Transfer function design is an important problem that receives much attention from the visualization community. Several researches have inspired the creation of better tools and techniques to deal with volumetric datasets. There are two major classes of datasets, namely structured and unstructured grids. Most of the previous work has only addressed structured data. This work presents two groups of contributions of different nature. The first contribution is related to the general problem of transfer function design. It introduces the concept of ensembles, which are complex transfer functions created from standard types. It also presents a key-frame based approach to handle time-varying sequences. The second group of contributions is related with a study on several characteristics of unstructured data. Problems have been discovered and addressed to allow a seamless integration of classical structured grids tools to unstructured data. This work includes results that show improvements on a statistical analysis of the data, as well as the developed transfer function design system. Further work is suggested to take advantage of the enhanced version of the gradient-magnitude histogram, and explore different boundary model.

Transcranial magnetic stimulation (TMS) is a non-invasive technique that can be used to assess the integrity neuronal circuits in the motor cortex, both at the intrahemispheric and interhemispheric level. In the present study, TMS was used to examine age-related modulation of corticospinal function. Participants underwent hand function testing to examine possible links between TMS measures and manual ability. Participants consisted of healthy young (n=13) and senior (n=17) right-handed individuals. Hand function testing consisted of a battery of tests administered bilaterally to assess each participant’s dexterity, strength, movement speed and reaction time. The following TMS measures were assessed bilaterally: resting motor threshold, recruitment curve and silent periods of the contralateral and ipsilateral hand. Both young and senior subjects showed significant intermanual differences in most behavioral measures, favoring their dominant right hand. There was an age-related difference in TMS measures indicating a decline in intrahemispheric excitability and interhemispheric inhibition. A general trend linking specific TMS measures in the active state with age-related changes in hand function on the dominant hand was found. Our results suggest that TMS markers of corticospinal excitability can be used to predict declining hand function with age and thus could provide an early diagnosis of pathological aging.

La théorie de la fonctionnelle de la densité (DFT) est une reformulation du problème quantique à N corps où l'énergie de l'état fondamental est exprimée sous la forme d'une fonction de la densité électronique. Dans l'approche de Kohn-Sham de la DFT, seule l'énergie dite d'échange-corrélation décrivant la partie non classique de l'interaction électron-électron nécessite d'être approchée comme une fonctionnelle de la densité. Dans le cadre de la thèse nous nous intéressons à une approximation visant à améliorer la précision et qui consiste à combiner de façon rigoureuse une approximation de type " fonctionnelle de la densité " avec un calcul explicite de type " fonction d'onde " à l'aide d'une décomposition de l'interaction électron-électron coulombienne. L'objectif est de disposer de méthodes améliorant la précision de la DFT actuelle avec un effort de calcul restant compétitif. Ce travail de thèse se décompose en trois études distinctes. Une première étude a consisté a étendre l'analyse de la convergence en base à la séparation de portée qui a permit de mettre en évidence une convergence exponentielle pour l'énergie de corrélation MP2 de longue portée. Dans un second temps nous nous sommes intéressés à une approximation auto-cohérente des fonctionnelles double-hybride utilisant la méthode des potentiels-effectifs-optimisés. Finalement la troisième étude propose une analyse de l'approximation adiabatique semi-locale du noyau d'échange et de corrélation de courte portée dans le cadre de la TDDFT avec séparation de portée dans son formalisme de réponse linéaire
The theory of the functional of the density ( DFT) is a reformulation of the quantum problem in N body where the energy of the fundamental state is expressed under the shape of a function(office) of the electronic density. In the approach of Kohn-Sham of the DFT, only the said energy of exchange-correlation describing the not classic part(party) of the interaction electron-electron requires to be approached as a functional of the density. Within the framework of the thesis(theory) we are interested in an approximation to improve the precision and which consists in combining(organizing) in a rigorous way an approximation of type(chap) " functional of the density " with an explicit calculation of type(chap) " function(office) of wave " by means of a decomposition of the interaction electron-electron coulombienne. The objective is to have methods

Electrical Impedance Tomography (EIT) is a fast, portable imaging technique that produces tomographic images of the internal impedance of an object from surface electrode measurements. This thesis reports the first use of EIT to image evoked brain activity in adults and neonates and determines whether accurate EIT images could be obtained from the adult and neonatal brain. In addition, a realistic head-tank phantom was developed to test the performance of EIT with known impedance changes placed within a real human skull. Two EIT systems were used. Images were obtained using 31 or 21 Ag/AgCl EEG scalp electrodes in adults and neonates, respectively, with either 256 or 187 individual impedance measurements from different electrode combinations: 2 applied a safe, alternating current and 2 measured the resultant scalp voltage. Imaging was performed using a block design with 6-15 stimulation periods of between 10-75s during either: 1) Visual, 2) Somatosensory or 3) Motor stimuli. Impedance changes were detected in 38/39 adults and 9/9 neonates within 0.6-5.8s after stimulus onset, and returned to baseline 7.6-36s after stimulus cessation. Reconstructed images were noisy: -20-70% images showed correct localisation to the expected area of cortex stimulated by the visual, motor or somatosensory paradigms. As EIT images from the head-tank localised changes within 10% of the impedance perturbation, this indicated that poor localisation in humans was not due to the head-shape or the skull, but may be related to unknown physiological factors. An improved EIT reconstruction algorithm, using a computerised finite-element model of the head, showed improved localisation for the adult images. This is the first demonstration that EIT can detect and image impedance changes in the head, probably due to increased regional cerebral blood volume in the activated cortex. Improvements may enable more accurate neuroimaging of the adult and neonatal brain for use in clinical practice.

The present study presents the research findings of the first ever multi-modular Paenibacillus mucilaginosus glycoside hydrolase (PmGH). Furthermore, we report the successful crystallisation of a multi-modular GH. The GH is composed of two catalytic modules (GH5 and GH6) and two carbohydrate binding modules (both CBM3). Functional analysis demonstrated that the cellulase, mannanase and xylanase activities of PmGH (130 kDa) were attributed to the GH5 catalytic domain. The presence of the GH6 catalytic domain resulted in slightly increased cellulase activity in PmGH. Optimal PmGH activity and functional stability was highest at pH 4-6 and at 40-60°C The structural properties of PmGH that determine its robust nature were further investigated. Homology modelling of PmGH showed the GH5 and GH6 domains to be independent but provided no structural information for the CBMs and linker regions. However, successful homology modelling of the individual domains indicated that the combination of the modules makes PmGH structurally and functionally novel. Glycoside hydrolases occur as independent modules or as part of a multi-modular protein with other catalytic and/or non-catalytic modules. Multiple combinations of these modules can occur in nature resulting in novel proteins such as PmGH. In an attempt to determine the PmGH crystal structure, a range of crystallisation conditions were tested. After extensive screening and optimisation, multiple PmGH crystals were diffracted, using both local diffraction and Synchrotron radiation sources (ESRF, France). Overall ~90% of the PmGH protein crystals did not diffract and of the remaining ~10% yielded unsatisfactory data. Phasing by molecular replacement also yielded no structural solutions. Alternative phasing methods such as multi-wavelength anomalous dispersion were also unsuccessful due to the quality of the diffraction data collected. Given the severe lack of multi-modular GH crystal structures in protein structure databases, the present study highlights the major limitations in structural studies of these important enzymes.
Thesis (PhD)--University of Pretoria, 2018.
Genetics
PhD
Unrestricted

Thesis (Ph.D.)--Biomedical Engineering, Georgia Institute of Technology, 2007.
Committee Chair: Hu, Xiaoping; Committee Member: Brummer, Marijn; Committee Member: Butera, Robert; Committee Member: Oshinski, John; Committee Member: Sathian, Krish.

High-throughput genomics projects have resulted in a rapid accumulation of protein sequences. Therefore, computational methods that can predict protein functions and functional sites efficiently and accurately are in high demand. In addition, prediction methods utilizing only sequence information are of particular interest because for most proteins, 3-dimensional structures are not available. However, there are several key challenges in developing methods for predicting protein function and functional sites. These challenges include the following: the construction of representative datasets to train and evaluate the method, the collection of features related to the protein functions, the selection of the most useful features, and the integration of selected features into suitable computational models. In this proposed study, we tackle these challenges by developing procedures for benchmark dataset construction and protein feature extraction, implementing efficient feature selection strategies, and developing effective machine learning algorithms for protein function and functional site predictions. We investigate these challenges in three bioinformatics tasks: the discovery of transmembrane beta-barrel (TMB) proteins in gram-negative bacterial proteomes, the identification of deleterious non-synonymous single nucleotide polymorphisms (nsSNPs), and the identification of helix-turn-helix (HTH) motifs from protein sequence.

Despite a mutual interest in disordered behavior, the psychological approaches of individual differences and behaviorism historically have had little common research or discourse. Moreover, over time, both fields independently have developed methods of assessment and treatment that--despite being broadly applicable across populations--exist only in parallel. This also is despite the facts that (1) individual differences frequently are defined by specific types of behavior (or lack thereof), and (2) behavioral analyses may include "organism" variables that share features with temperament variables. The primary goal of the current study is to examine relations between broad temperament factors and the function of problem behavior(s) identified through formal clinical assessment. The proposed model hypothesizes unique contributions of extraversion/surgency/positive affectivity (E/SPA) and neuroticism/negative affectivity (NNA) to the behavior functions of attention and escape, respectively. Subsidiary goals of the study included replicating previously identified temperament factors in this sample and assessing relations among temperament scales and behavioral form(s). Fifty-three children and their caregivers were recruited from 4 behavior treatment clinics at the University of Iowa. Caregivers were asked to complete two measures of temperament/personality: the Children's Behavior Questionnaire Short Form (CBQ) and the Schedule for Nonadaptive and Adaptive Personality--Other Report Form (SNAP-ORF). Children also underwent behavior assessment procedures as part of their scheduled clinic appointment, and these records were subsequently accessed to code function, form, frequency, and severity of problem behaviors. Results showed significant, positive relations between E/S-PA and measures of attention function. These findings were consistent across several (though not all) measures of E/S/PA and attention function. In contrast, no significant relation between N-NA and either escape or attention was found. Structural modeling of temperament/personality was broadly consistent with the three factors proposed by the CBQ and SNAP-ORF. Several unique findings at the lower order trait level also were noted and are discussed. The results from the current study provide an important first step in linking behavior and personality with regard to function in addition to behavioral form. Implications for the definitions of traits and function used in this project are discussed. Future research should expand on these preliminary findings to replicate and clarify relations among individual differences and behavioral functions.

Ordinary Dirichlet series, of which the Riemann zeta function is the most important, play a prominent role in classical analysis and number theory, and in modern mathematics. It is well-known that the Riemann zeta function has a single pole at the point s=1. The present thesis investigates both the behaviour of various zeta functions near this point and the function spaces of ordinary Dirichlet series they can be said to generate. Chapter 1 gives a comprehensive overview of the thesis and offers brief surveys of related results. Chapter 2 introduces a new scale of function spaces of Dirichlet series and explains the local behaviour of the reproducing kernels and establishes local embeddings into classical function spaces. Other such spaces are also considered, of which the Dirichlet-Hardy spaces are the most important. Chapter 3 determines the spaces spanned by the real parts of the boundary functions and distributions in the different settings. Chapter 4 characterises the local interpolating sequences for the Hilbert spaces under consideration. In the non-Hilbert spaces only partial results are obtained. Chapter 5 deals with a family of zeta functions corresponding to subsets of the integers. A complete characterisation of their behaviour close to the points = 1 is given in terms of lower norm bounds of integral operators with the zeta functions as kernels. Chapter 6 considers the results of the previous chapter under the additional hypothesis of arithmetic structure. The characterisations become simpler and more can be said.

Maintenance of physical function with advancing age is vital to continued independent living, which is highly valued by older people. Although commonly associated with the ageing process, loss of functional ability may well be accelerated by inactivity and subsequent decreasing physical capacities, such as muscle performance or balance abilities. The impact of increased levels of activity on physical performance and functional ability was investigated by a single blind randomised controlled study.Two intervention programs, one based on increased levels of physical activity and the second on increased levels of social activity, were provided to a group of community-living participants aged 75 years and over. Another group, receiving no intervention was also included. The exercise intervention offered twice weekly sessions of exercise over a 16-week period. This was designed and supervised by physiotherapists. The social intervention offered a weekly, two-hour session over 13 weeks. Baseline, post-intervention and follow-up assessments measured aspects of physical performance (muscle, balance, gait and step height performance) and functional ability (tiredness of limbs, mobility tiredness and the need for assistance with mobility and activities of daily living). In addition, all participants completed a monthly health and falls report. One hundred and forty-nine subjects were admitted into the study with 108 completing the intervention phase and all four assessments.Analysis of data indicated that the exercise intervention was effective in improving muscle performance (shoulder abduction mean difference 13.00, 95%CI 11.63-14.37; hip abduction mean difference 5.97, 95%CI 4.73-7.20; knee flexion mean difference 4.10, 95%CI 3.32-4.88; dorsiflexion mean difference 4.72, 95%CI 3.74-5.71), dynamic balance ability (Functional Reach mean difference 11.45, 95%CI 9.41-13.48), ++
maximal gait speed (mean difference 0.62, 95%CI 0.50-0.74) and step height performance (mean difference 0.19, 95%CI 0.01-0.29). Improvements in dynamic balance and maximal walk performance were maintained for a period of four months following cessation of the intervention. The social program did not affect aspects of physical performance.Functional improvements were evident for both exercise and social subjects. Immediate improvements in limb tiredness (upper mean difference 0.37, 95%CI -0.11-0.84; lower mean difference 0.63, 95%CI 0.37-0.89) and mobility tiredness (mean difference 1.43, 95%CI 1.16-1.70) and activities of daily living dependence (mean difference 0.25, 95%CI -0.23-0.75) were demonstrated. Four and eight months later, exercise subjects had maintained the improvement in mobility tiredness and activities of daily living dependence. Mobility dependence showed a delayed improvement in both the exercise and social intervention participants. This improvement was not evident immediately following intervention, but emerged at both the four and eight month follow-up assessments.An intention to treat analysis (involving both completing and non-completing subjects) confirmed the usefulness of the exercise intervention as a strategy to improve and maintain functional ability in older subjects, specifically with regard to tiredness of the lower limbs, tiredness during mobility tasks and activities of daily living dependence. In addition, following the cessation of the exercise intervention, participants reported less mobility tiredness and dependence in activities of daily living tasks over the following eight-month period.The relationship between physical performance and functional ability indicated that muscle performance and limb tiredness were significantly associated. Decreased muscle performance of the upper limb was associated with reports of increased ++
tiredness during functional activities involving the upper limb, such as combing hair and dressing the upper body. Similarly, decreased muscle performance of the lower limb, especially proximally, was associated with increasing tiredness of the lower limb during functional activities. Further, decreased proximal muscle performance of both the upper and lower limb was significantly associated with decreasing independence in the performance of physical activities of daily living. These results indicate the significant influence of muscle performance on functional ability, especially on tiredness of the limbs and activities of daily living dependence.The ability to predict future functional limitation, based on decreasing physical performance, was examined and shown to be of limited value. Hip muscle performance and changes in usual gait speed were poorly associated with increased lower limb tiredness and dependence in physical activities of daily living respectively. The lack of a robust relationship between variables of physical performance and functional ability measures indicates that loss of physical performance is not strongly associated with the development of functional limitations.Self-reported falls were monitored throughout the study. A significant increase in the number of participants reporting falls was evident in both the social intervention group and the control group throughout the study. In contrast, there was no change in the number of exercise participants reporting falls. These results suggest that the exercise intervention was effective at minimising the usual increase in the number of older people experiencing falls over time.The results of this study suggest that the exercise intervention program was effective in improving physical performance in elderly subjects. This also resulted in improved functional ability. Positive effects continued ++
following completion of the program as improvements in mobility and activities of daily living tasks were demonstrated for a further eight months. By contrast, the social intervention program appeared to influence only the need for help with mobility tasks in the longer term.Increased physical activity, in the form of an exercise intervention program, specifically designed for community-living elderly people, can improve and maintain functional ability, both immediately and for up to eight months following the completion of the program. As such, involvement in exercise, even in the short-term, should be encouraged as a means of maintaining physical independence in later life. Therapists devising exercise programs specifically for older people should ensure that the associated outcome measures incorporate assessments of functional ability and not simply measures of impairment. This study has demonstrated that a real benefit of increased physical activity in older people may well be the increased physical independence associated with participation.

My research studies algebras of holomorphic functions from $d$-tuples of $n\times n$- matrices, $M_n(\bC)^d$, to $M_n(\bC)$. In particular, I study the holomorphic functions that can be approximated by \emph{polynomial matrix concomitants}, that is polynomial maps from $M_n(\bC)^d$ to $M_n(\bC)$ that satisfy the relationship \[ f(g^{-1}\fz g) = g^{-1}f(\fz)g \] for every $\fz \in M_n(\bC)^d$ and $g\in GL_n(\bC)$. In a sense, these are the polynomial maps that “remember” the structure of the $d$-tuple $\fz$. My first result is that these holomorphic matrix concomitants can be identified with holomorphic cross sections of certain matrix bundles. A holomorphic matrix bundle is a fibred space in which every fibre is $M_n(\bC)$ and the fibres are glued together in such a way that the total space has a holomorphic structure. Once the identification between holomorphic cross sections and holomorphic concomitants is established, the structure of the matrix bundle is used to endow the algebra of continuous cross sections with a $C^*$-algebra structure. Then we study the subalgebra of cross sections that can be approximated by polynomial concomitants. By identifying the matrix concomitants with cross sections, we are able to prove interesting results about these algebras.

Maintenance of physical function with advancing age is vital to continued independent living, which is highly valued by older people. Although commonly associated with the ageing process, loss of functional ability may well be accelerated by inactivity and subsequent decreasing physical capacities, such as muscle performance or balance abilities. The impact of increased levels of activity on physical performance and functional ability was investigated by a single blind randomised controlled study.Two intervention programs, one based on increased levels of physical activity and the second on increased levels of social activity, were provided to a group of community-living participants aged 75 years and over. Another group, receiving no intervention was also included. The exercise intervention offered twice weekly sessions of exercise over a 16-week period. This was designed and supervised by physiotherapists. The social intervention offered a weekly, two-hour session over 13 weeks. Baseline, post-intervention and follow-up assessments measured aspects of physical performance (muscle, balance, gait and step height performance) and functional ability (tiredness of limbs, mobility tiredness and the need for assistance with mobility and activities of daily living). In addition, all participants completed a monthly health and falls report. One hundred and forty-nine subjects were admitted into the study with 108 completing the intervention phase and all four assessments.Analysis of data indicated that the exercise intervention was effective in improving muscle performance (shoulder abduction mean difference 13.00, 95%CI 11.63-14.37; hip abduction mean difference 5.97, 95%CI 4.73-7.20; knee flexion mean difference 4.10, 95%CI 3.32-4.88; dorsiflexion mean difference 4.72, 95%CI 3.74-5.71), dynamic balance ability (Functional Reach mean difference 11.45, 95%CI 9.41-13.48), maximal gait speed (mean difference 0.62, 95%CI 0.50-0.74) and step height performance (mean difference 0.19, 95%CI 0.01-0.29). Improvements in dynamic balance and maximal walk performance were maintained for a period of four months following cessation of the intervention. The social program did not affect aspects of physical performance.Functional improvements were evident for both exercise and social subjects. Immediate improvements in limb tiredness (upper mean difference 0.37, 95%CI -0.11-0.84; lower mean difference 0.63, 95%CI 0.37-0.89) and mobility tiredness (mean difference 1.43, 95%CI 1.16-1.70) and activities of daily living dependence (mean difference 0.25, 95%CI -0.23-0.75) were demonstrated. Four and eight months later, exercise subjects had maintained the improvement in mobility tiredness and activities of daily living dependence. Mobility dependence showed a delayed improvement in both the exercise and social intervention participants. This improvement was not evident immediately following intervention, but emerged at both the four and eight month follow-up assessments.An intention to treat analysis (involving both completing and non-completing subjects) confirmed the usefulness of the exercise intervention as a strategy to improve and maintain functional ability in older subjects, specifically with regard to tiredness of the lower limbs, tiredness during mobility tasks and activities of daily living dependence. In addition, following the cessation of the exercise intervention, participants reported less mobility tiredness and dependence in activities of daily living tasks over the following eight-month period.The relationship between physical performance and functional ability indicated that muscle performance and limb tiredness were significantly associated. Decreased muscle performance of the upper limb was associated with reports of increased tiredness during functional activities involving the upper limb, such as combing hair and dressing the upper body. Similarly, decreased muscle performance of the lower limb, especially proximally, was associated with increasing tiredness of the lower limb during functional activities. Further, decreased proximal muscle performance of both the upper and lower limb was significantly associated with decreasing independence in the performance of physical activities of daily living. These results indicate the significant influence of muscle performance on functional ability, especially on tiredness of the limbs and activities of daily living dependence.The ability to predict future functional limitation, based on decreasing physical performance, was examined and shown to be of limited value. Hip muscle performance and changes in usual gait speed were poorly associated with increased lower limb tiredness and dependence in physical activities of daily living respectively. The lack of a robust relationship between variables of physical performance and functional ability measures indicates that loss of physical performance is not strongly associated with the development of functional limitations.Self-reported falls were monitored throughout the study. A significant increase in the number of participants reporting falls was evident in both the social intervention group and the control group throughout the study. In contrast, there was no change in the number of exercise participants reporting falls. These results suggest that the exercise intervention was effective at minimising the usual increase in the number of older people experiencing falls over time.The results of this study suggest that the exercise intervention program was effective in improving physical performance in elderly subjects. This also resulted in improved functional ability. Positive effects continued following completion of the program as improvements in mobility and activities of daily living tasks were demonstrated for a further eight months. By contrast, the social intervention program appeared to influence only the need for help with mobility tasks in the longer term.Increased physical activity, in the form of an exercise intervention program, specifically designed for community-living elderly people, can improve and maintain functional ability, both immediately and for up to eight months following the completion of the program. As such, involvement in exercise, even in the short-term, should be encouraged as a means of maintaining physical independence in later life. Therapists devising exercise programs specifically for older people should ensure that the associated outcome measures incorporate assessments of functional ability and not simply measures of impairment. This study has demonstrated that a real benefit of increased physical activity in older people may well be the increased physical independence associated with participation.

Orientadores : Dr. Paulo da Cunha Lana, Dr. Britas Klemens Eriksson
Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências da Terra, Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos. Defesa: Pontal do Paraná, 21/04/2017
Inclui referências
Resumo: Na presente tese, investiguei como a função do macrobentos marinho de sistemas sedimentares rasos é afetada pela poluição ambiental, complexidade do habitat e mudanças na composição específica das assembleias. Utilizei uma abordagem analítica baseada em traços biológicos para estimar potenciais mudanças na função do macrobentos nos processos ecossistêmicos associados aos sedimentos. Meus objetivos de pesquisa incluem avaliações do papel dos gradientes ambientais naturais ou antropogênicos na estrutura funcional do macrobentos; da aplicabilidade das abordagens baseadas em traços biológicos para analisar a qualidade ambiental do bentos; dos efeitos das mudanças na composição específica das assembleias na função do macrobentos; do efeito da complexidade do habitat na diversidade de traços funcionais; e do impacto de espécies funcionalmente relevantes no funcionamento ecossistêmico. Os resultados e conclusões mais importantes desta tese foram: 1. Baixa qualidade do ambiente bêntico causada pelo enriquecimento orgânico prejudica o estabelecimento de espécies com determinados traços funcionais, resultando em assembleias com baixa diversidade funcional. 2. Abordagens baseadas em traços biológicos são uma forma válida de avaliação os efeitos gerais da poluição orgânica no macrobentos. Tanto a análise de traços biológicos quanto os índices multivariados de diversidade funcional representam boas ferramentas analíticas para a investigação de mudanças na estrutura macrobêntica ao longo de gradientes de contaminação orgânica. 3. As mudanças na estrutura das assembleias promovidas pelo estabelecimento de espécies exóticas podem levar a grandes mudanças na diversidade funcional do macrobentos. Essas mudanças podem aumentar o potencial de bioturbação das assembleias e ter implicações para o funcionamento do ecossistema nos sistemas sedimentares. 4. O aumento da complexidade do habitat promovido pelas gramas marinhas pode promover funções relacionadas com os sedimentos devido ao estabelecimento de organismos bioturbadores que habitam camadas superficiais do sedimento. 5. As espécies funcionalmente relevantes do macrobentos podem promover o microfitobentos, seja através do aumento da bioturbação dos sedimentos ou através da estabilização dos sedimentos devido à atenuação da hidrodinâmica local. 6. As espécies funcionalmente relevantes podem promover cascatas funcionais por favorecer o estabelecimento de organismos que desempenham outras funções. Nos casos abordados nesta tese, as gramas marinhas promovem a infauna que vive próximo à superfície do sedimento e indiretamente media processos relacionados à bioturbação; a bioturbação macrobêntica influencia os produtores primários por afetar a estrutura microfitobêntica e os bancos de mexilhões promovem a produção primária por favorecer o microfitobentos. 7. Os índices de diversidade funcional são úteis como uma ferramenta exploratória para avaliar os efeitos gerais de perturbações ou gradientes ambientais na estrutura do macrobentos. Por outro lado, a análise de traços biológicos ou o enfoque em identidades funcionais representa uma melhor abordagem para avaliar os efeitos funcionais gerais do macrobentos na estrutura e nos processos ecossistêmicos.
Abstract: In this doctoral thesis, I investigate how the function of sediment living organisms is affected by environmental pollution, habitat complexity and changes in assemblage composition in shallow sedimentary systems. I used a trait-based approach to estimate potential changes in function of the macrobenthos in sediment-related ecosystem processes. My research subjects include: the role of natural and human induced gradients in shaping assemblage functional trait structure; the applicability of trait-based approaches to assess environmental status; the effects of changes in assemblage composition on macrobenthic function; the effect of complexity on functional diversity; and the impact of functionally relevant species on ecosystem functioning. The most important findings and conclusions of this thesis are: 1. Low benthic environmental quality driven by organic enrichment hinders the establishment of macrobenthic species with specific functional traits, resulting in assemblages with differentiated trait composition and decreased functional diversity. 2. Trait-based approaches are a reliable way to assess general effects of organic pollution on the macrobenthos. Both biological trait analysis and multivariate functional diversity are good analytical tools to analyze changes in macrobenthic structure across organic contamination gradients, although biomass- and abundancebased analysis can differ. 3. Changes in assemblage structure driven by establishing alien species can drive major changes in macrobenthic functional diversity. These changes can drive increased bioturbation potential, and have implications for ecosystem functioning in sedimentary systems. 4. Increased habitat complexity driven by seagrasses can promote sediment-related functions by favoring the establishment of shallow-living macrobenthic bioturbators. 5. Functionally relevant macrobenthic species can promote microphytobenthos either by increasing sediment bioturbation or by sediment stabilization via flow attenuation. 6. Functionally relevant species can promote functional cascades by favoring the establishment of organisms that perform other functions. In the cases addressed in this thesis, seagrasses promote shallow-living infauna and indirectly mediate bioturbation-related processes; macrobenthic bioturbation drives primary producers by affecting microphytobenthic structure; and mussel beds promote primary production by favoring microphytobenthos. 7. Functional diversity indices are useful as an exploratory tool to assess general effects of disturbances or gradients on macrobenthic structure. On the other hand, biological trait analysis or the focus on functional identities represents a better approach to assess the general functional effects of the macrobenthos on ecosystem structure and processes.
Samenvatting: In dit proefschrift onderzoek ik hoe de ecologische functie van bodemorganismen wordt beïnvloed door milieuvervuiling, habitatcomplexiteit en veranderingen in de soortensamenstelling binnen ondiepe sedimentaire ecosystemen. Ik heb gebruik gemaakt van een aanpak gericht op fenotypische kenmerken (een zogeheten trait-based approach) om een inschatting te maken van potentiële veranderingen in de functie van het macrobenthos binnen sedimentgerelateerde ecosysteemprocessen. Onderwerpen binnen mijn onderzoek zijn: de rol van natuurlijke en door de mens veroorzaakte gradiënten bij het vormen van de functionele structuur van ecologische gemeenschappen; de toepasbaarheid van de trait-based approach om de toestand van het milieu te beoordelen; de effecten van veranderingen in de soortensamenstelling op de functie van het macrobenthos; de effecten van complexiteit op functionele diversiteit; en de invloed van functioneel relevante soorten op het functioneren van ecosystemen. De belangrijkste bevindingen en conclusies van dit proefschrift zijn: 1. Lage kwaliteit van de benthische omgeving, gedreven door organische verrijking, verhindert de vestiging van macrobenthische soorten met specifieke functionele kenmerken. Dit resulteert in samenstellingen met verschillende eigenschappen en verminderde functionele diversiteit. 2. De trait-based approach is een betrouwbare manier om de algemene effecten van organische vervuiling op het macrobenthos te beoordelen. Zowel een analyse van biologische kenmerken als multivariate indices van functionele diversiteit zijn nuttige analytische methoden om de veranderingen in macrobenthische structuur in verschillende gradiënten van organische vervuiling te analyseren, ondanks dat biomassa- en abundantie-analyse kunnen verschillen. 3. Veranderingen in de structuur van de soortensamenstelling gedreven door de vestiging van uitheemse soorten, kan grote veranderingen in de macrobenthische functionele diversiteit veroorzaken. Deze veranderingen kunnen een verhoogd bioturbatiepotentieel veroorzaken en hebben implicaties voor het functioneren van bodemecosystemen. 4. Toegenomen habitatcomplexiteit gedreven door zeegrassen kan sedimentgerelateerde functies bevorderen door de vestiging van ondiep levende macrobenthische bioturbators. 5. Functioneel relevante macrobenthische soorten kunnen het microfytobenthos begunstigen door bioturbatie van het sediment te verhogen of door het sediment te stabiliseren middels het verzwakken van de stroming. 6. Functioneel relevante soorten kunnen functionele cascades bevorderen door de vestiging van organismen die andere functies uitvoeren te begunstigen zoals in de gevallen besproken in dit proefschrift: zeegrassen bevorderen ondiep levende infauna en bemiddelen indirect bioturbatiegerelateerde processen; macrobenthische bioturbatie drijft primaire producenten door de microfytobenthische structuur te beïnvloeden; en mosselbedden bevorderen primaire productie door microfytobenthos te begunstigen. 7. Indicatoren van functionele diversiteit zijn nuttig als verkennend hulpmiddel om de algemene effecten van verstoringen of gradiënten op de macrobenthische structuur te beoordelen. Anderzijds vertegenwoordigen de analyse van biologische kenmerken of de focus op functionele identiteit een betere aanpak om algemene functionele effecten van het macrobenthos op de processen en de structuur van het ecosysteem te beoordelen.

In leading up to the proof, methods for constructing fields and finitely additive set functions are introduced with an application involving the Tagaki function given as an example. Also, non-absolutely continuous set functions are constructed using Banach limits and maximal filters.

Age-related decline in memory and other cognitive functions, such as visuospatial functions is widely studied and well documented. In recent years, some studies have also found relationships between memory performance and functional body lateralization, with individuals who are inconsistently lateralized (e.g. have inconsistent handedness) scoring higher on episodic memory tests. The objectives of this study were to investigate relationships and possible differences between episodic and semantic memory performance, and visuospatial functions as a function of functional lateralization consistency in a large population-based study. In total, 1283 adult men and women participants, with age ranging from 25 to 100 years, were tested within the Betula prospective cohort study (Nilsson et al., 1997) where they were included in the fifth wave (T5) of data collection. Participants were divided into groups of consistent or inconsistent functional lateralization regarding respective hand-, foot-, and eyedness. Results revealed weak to moderate relationship between variables of functional laterality and its consistency. While age was significant predictor of memory performance and visuospatial functions, sex and functional laterality consistency variables were insignificant. Results are discussed in relation to previous studies and to hemispheric interaction theory.
Betula prospective cohort study (Nilsson et al., 1997, 2004)

In the recent years one of the lines of in vestigation in the Neur obiology Laboratory at SISSA has been to study the molecular det erminants of Alzheimer’s Disease (AD), one of the most known and diffused neur odegenerative aging diseases. AD is characterized by lesions in the brai n cortex, including the presence of β -amyloid plaques and neurofibrillary tangles c ontaining phosphorylated tau protein. In Alzheimer’s disease neuronal degeneration is found in selected areas of the brain, in particular in cortical, hippocam pal and basal forebrain cholinergic neurons (reviewed in Price et al ., Ann. Rev. Neurosci., 1986) . The investigation on the involvement of the neurotrophin Nerve Gr owth Factor (NGF) in AD has been extensive, because it promotes the survival and regulates the function of cholinergic neurons of the basal forebr ain. (reviewed in Counts et al. , J. Neuropath. Exp. Neuro., 2005). NGF is translated as a pre- pro-protein, proNGF, the im portance of which in the recent years has grown much, thanks to impor tant findings on its bi ological functions, besides the one of promoting protein foldin g. Accordingly, the increasing number of involved new actors has complicated also t he scenario of the investigations on the molecular determinants in AD.

L'émergence de la technologie de virtualisation des fonctions réseau (NFV) a suscité un vif intérêt autour de la conception, la gestion et le déploiement de services réseau de manière flexible, automatisée et indépendante du fournisseur. La mise en œuvre de la technologie NFV devrait être une solution profitable pour les fournisseurs de services et les clients. Cependant, ce changement de paradigme, amorcé par NFV, nécessite un abandon progressif des services réseau fournis à travers des équipements dédiés. En contrepartie, un environnement totalement ou partiellement virtualisé est proposé pour instancier dynamiquement et à la demande des modules logiciels appelés fonctions de réseau virtuelles (VNF). Cette évolution soulève un ensemble de défis liés au déploiement et à l'exploitation de services, tels que l'orchestration et la gestion, la résilience des services, le contrôle de la qualité de service (QoS), l’approvisionnement des ressources, etc. En outre, la question centrale à résoudre dans le contexte NFV est la suivante : « comment placer et chaîner effacement des fonctions virtuelles d’un service afin de fournir un niveau de qualité demandé par le client tout en optimisant l'utilisation des ressources par le fournisseur de services ? ”.Ainsi, cette thèse étudie la problématique du placement et du chaînage des VNF en tenant compte de certaines exigences de service telles que le délai de bout en bout, la disponibilité du service et la consommation d'énergie, et propose un ensemble d'algorithmes et de mécanismes visant à optimiser le déploiement des services demandés/fournis. Nos contributions dans cette thèse sont triples. Premièrement, nous proposons deux algorithmes de placement et de chaînage de VNF sensibles au délai de bout-en-bout pour des applications temps-réel. Les algorithmes proposés visent à respecter le délai approprié de bout-en-bout qui dépend du service déployé (exemples : VoIP, Streaming, etc.). Deuxièmement, nous présentons une analyse comparative de la disponibilité des services et nous proposons deux mécanismes de placement et de chaînage de VNF pour garantir un niveau prédéfini de disponibilité. L’objectif est de fournir des services résilients en ajustant avec précision les paramètres du schéma de protection (nombre, type, emplacement et taille des instances VNF) nécessaires pour atteindre ce niveau de disponibilité en dépit des défaillances du réseau. Enfin, nous proposons une architecture générale qui explore la possibilité d’étendre le paradigme de la virtualisation à l’Internet des objets (IoT). À cette fin, nous définissons un mécanisme de placement et de chaînage respectant les contraintes énergétiques pour des services IoT. Notre architecture propose de découpler et de virtualiser les fonctionnalités inhérentes à un objet connecté de l’équipement IoT physique. En étendant NFV au domaine IoT, notre solution ouvre de nouvelles perspectives d’application en supportant de nouveaux cas d’usages
The emergence of Network Function Virtualization (NFV) technology has aroused keen interest to design, manage and deploy network services in a flexible, automated and vendor-agnostic manner. Implementing NFV technology is expected to be a win-win solution for both service providers and costumers. However, this paradigm shift, sparked by NFV, calls for a progressive abandon of network services that are provided as hardware appliance and rather it proposes a fully or partially virtualized environment that offers software modules called Virtual Network Functions (VNFs). This shift rises a set of challenges related to service deployment and operation such as orchestration and management, service resiliency, Quality of Service (QoS) and resource provisioning among others. Furthermore, the core question that needs to be solved within NFV context is “What is the best way to place and chain VNFs that form a service in order to meet Service Level Agreement requirements (costumer side) while optimizing resource usage (service provider side)?”.This thesis investigates the problem of VNF Placement and Chaining considering service requirements such as end-to-end delay, service availability and energy consumption and proposes a set of algorithms and mechanisms that aim to achieve an optimized deployment of the requested/provided services. Our contributions in this thesis are threefold. First, we propose a delay-aware Placement and Chaining algorithms for delay-sensitive applications over NFV networks. The proposed algorithms aim to meet the appropriate end-to-end delay defined according to the deployed service (VoIP, Streaming, etc.). Second, we provide a comprehensive service availability benchmarking and we propose two availability-aware mechanisms for VNFs chain. The aim is to provide resilient service provisioning by fine-tuning the parameters of the protection scheme (the number, the type, the placement and the size of the spare instances) needed to reach a predefined availability level, despite network failures. Finally, we propose a framework architecture that explores the possibility to extend the virtualization paradigm to Internet of Things (IoT). Toward this end, we define an energy-aware Placement and Chaining for IoT services where inherent IoT functionalities are decoupled from specific dedicated IoT devices and instantiated on-demand. By bringing together NFV and IoT paradigms, this extension opens new perspectives and push toward designing new use cases

Algoritmos exatos para fatoração estão limitados a funções Booleanas read-once, onde cada variável aparece uma vez na equação final. No entanto, estes algoritmos apresentam duas restrições principais: (1) eles não consideram funções Booleanas incompletamente especificadas, e (2) eles não são adequados para as funções binate. Para superar o primeiro inconveniente, é proposto um algoritmo que encontra equações read-once para funções Booleanas incompletamente especificadas, sempre que possível, é proposto. Com respeito à segunda limitação, é apresentada uma transformação de domínio que divide variáveis binate existentes em duas variáveis unate independentes. Tal transformação de domínio conduz a funções Booleanas incompletamente especificadas, que podem ser eficientemente fatoradas mediante a aplicação do algoritmo proposto. A combinação das duas contribuições dá resultados ótimos para uma nova classe de funções Booleanas chamada read-polarity-once, onde cada polaridade (positiva ou negativa) de uma variável aparece no máximo uma vez na forma fatorada da expressão Booleana. Resultados experimentais sobre circuitos ISCAS'85 mostrou que funções read-polarity-once são significativamente mais frequentes em circuitos reais quando comparado com a classe de funções read-once, a qual muitos trabalhos já foram dedicados na literatura.
Efficient exact factoring algorithms are limited to read-once functions, in which each variable appears once in the final Boolean equation. However, those algorithms present two main constraints: (1) they do not consider incompletely specified Boolean functions; and (2) they are not suitable for binate functions. To overcome the first drawback, it is proposed an algorithm that finds read-once formulas for incompletely specified Boolean functions, whenever possible. With respect to the second limitation, a domain transformation that splits existing binate variables into two independent unate variables is presented. Such domain transformation leads to incompletely specified Boolean functions, which can be efficiently factored by applying the proposed algorithm. The combination of both contributions gives optimal results for a novel broader class of Boolean functions named as read-polarity-once functions, where each polarity (positive or negative) of a variable appears at most once in the factored form. Experimental results over ISCAS'85 benchmark circuits have shown that read-polarityonce functions are significantly more frequent than read-once functions, for which many works have already been devoted in the literature.

Cardiovascular diseases form one of the most dangerous events that affect human life. They are usually the result of high blood pressure. Thus controlling blood pressure within patient specific healthy limits is a goal that we must target. There are two control loops for blood haemostasis inside the body either long term or short term. Baroreceptors control the short term blood pressure regulation. They are nerve endings that exist in certain locations within the blood vessel walls and they report blood pressure into the brain and the central nervous system. However the basics of their function are not yet known. We propose here that the baroreceptors work by converting circumferential and axial pressure into a stress into their respective direction and they start to send nerve signals based on a threshold of strain energy of the location they are embedded in. Thus baroreceptors A fibre is highly likely to exist in the stiffer adventitia, while the media will contain C fibres. This explains the reason behind having identical fibres with different threshold. We were able to arrive to this solution by getting a relationship between stress–strain relationship for the whole wall and for the arterial vessels. These findings are quiet significant as they allow a method to identify different stress in the arterial wall layers using whole wall experimental data and also as they were able to differentiate between different fibres based on their locations inside the arterial wall. A complete modelling of the baroreceptors function might lead to the formation of biosynthetic material that could interact with the body on the cellular level, so as to give humans the mean to the control of short term blood regulation thus preventing hypertension and its accompanying diseases such as atherosclerosis.