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Understanding volunteer motivation has been widely recognized by both researchers and administrators as a valuable component of program development. Thus, it is important to explore the motivational needs that contribute to Virginia adult 4-H volunteerism. This quantitative research study was designed to fill a gap in the current volunteer literature regarding our understanding of the motivational needs of Virginia adult 4-H volunteers. The following research questions guided this study: 1. What are the motivations of Virginia adult 4-H volunteers and how are these volunteers distributed in terms of their primary motivational need (power, achievement, or affiliation)? 2. What is the relationship between motivational needs (power, achievement, and affiliation) and volunteer satisfaction as self-reported by Virginia adult 4-H volunteers? 3. To what extent are Virginia adult 4-H volunteers motivated to volunteer for Virginia 4-H? 4. To what extent do motivational needs (power, achievement, and affiliation) differ in urban and rural Virginia adult 4-H volunteers? 5. What are the most prevalent youth experiences influencing adult 4-H volunteerism in Virginia 4-H? Data were collected from 296 Virginia 4-H volunteers via a 20-item questionnaire utilizing McClelland's Trichotomy of Needs Theory. The results showed that the top three motives for volunteering with Virginia 4-H were within the achievement and power subscales and included to teach and lead others, to improve the community, and to have an influence on how young people learn and grow. Further, a significant positive relationship was revealed between motivational needs (achievement, affiliation, and power) and satisfaction level. Results also indicated that the majority of Virginia adult 4-H volunteers described their current motivational level as "motivated." Additionally, no significant differences were found between the motivational needs of urban and rural Virginia adult 4-H volunteers and 4-H involvement was the most prevalent youth experience that influenced the decision to volunteer for 4-H. Based on the results of this study, implications and recommendations for practice and further research were suggested. / Ph. D.

There is much interest in the design of feedback controllers for linear systems that minimize the H-infty norm of a specific closed-loop transfer function.  The H-infty optimization problem initiated by Zames (1981), \\cite{zames1981feedback}, has received a lot of interest since its formulation.  In H-infty control theory one uses the H-infty norm of a stable transfer function as a performance measure.  One typically uses approaches in either the frequency domain or a state space formulation to tackle this problem.  Frequency domain approaches use operator theory, J-spectral factorization or polynomial methods while in the state space approach one uses ideas similar to LQ theory and differential games.  One of the key computational issues in the design of H-infty optimal controllers is the determination of the optimal H-infty norm.  That is, determining the infimum of r for which the H-infty norm of the associated transfer function matrix is less than r.  Doyle  et al (1989), presented a state space characterization  for the sub-optimal H-infty control problem.  This characterization requires that the unique stabilizing solutions to  two Algebraic Riccati Equations are positive semi definite as well as satisfying a spectral radius coupling condition.  In this work, we describe an algorithm by Lin et al(1999),  used to calculate the H-infty norm for the state feedback and output feedback control problems.  This algorithm only relies on standard assumptions and divides the problem into three sub-problems. The first two sub-problems rely on algorithms for the state feedback problem formulated in the frequency domain as well as a characterization of the optimal value in terms of the singularity of the upper-half of  a matrix created by the stacked basis vectors of the invariant sub-space of the associated Hamiltonian matrix.  This characterization is verified through a bisection or secant method.  The third sub-problem relies on the geometric nature of the spectral radius of the product of the two solutions to the Algebraic Riccati Equations associated with the first two sub-problems.  Doyle makes an intuitive argument that the spectral radius condition will fail before the conditions involving the Algebraic Riccati Equations fail.  We present numerical results where we demonstrate that the Algebraic Riccati Equation conditions fail before the spectral radius condition fails. / Master of Science

Yes / UV/Vis absorption and NMR spectroscopy titrations have been used to investigate the formation of complexes between cations and neutral H-bond acceptors in organic solvents. Complexes formed by two different H-bond acceptors with fifteen different cations were studied in acetone and in acetonitrile. The effects of water and ion pairing with the counter-anion were found to be negligible in the two polar solvents employed for this study. The data were used to determine self-consistent H-bond donor parameters (α) for a series of organic and inorganic cations; guanidinium, primary, tertiary and quaternary ammonium, imidazolium, methylpyridinium, lithium, sodium, potassium, rubidium and caesium. The results demonstrate the transferability of α parameters for cations between different solvents and different H-bond acceptor partners, allowing reliable prediction of cation recognition properties in different environments. Lithium and protonated nitrogen cations form the most stable complexes, but the α parameter is only 5.0, which is similar to the neutral H-bond donor 3-trifluoromethyl, 4-nitrophenol (α = 5.1). Quaternary ammonium is the weakest H-bond donor investigated with an α value of 2.7, which is comparable to an alcohol. The α parameters for alkali metal cations decrease down the group from 5.0 (Li+) to 3.5 (Cs+). / Financial support from the Engineering and Physical Sciences Research Council (EP/K025627/2) and Unilever

For my thesis I explored the idea of the mask in relation to architecture. For my project I designed an art gallery located in Georgetown Washington DC which is composed of three layers: a structural layer, an environmental casing, and an outer layer. Theoretical parallels are drawn between the outer layer of the gallery and what is commonly referred to as a mask. Additionally, I explored the interaction between the layers of the gallery. The distinguishing characteristics of the building include the tri-facade mask, the unique spaces in between the gallery's layers, the glass system, the mask's ghost effect, and the floor system. / Master of Architecture

Les architectures mixtes contenant des composants programmables et d'autres reconfigurables peuvent fournir les performances de calcul nécessaires pour satisfaire les contraintes imposées aux applications temps réel. Mais l'implantation et d'optimisation de ces applications temps réel sur ce type d'architectures est une tâche complexe qui prend un temps énorme. Dans ce contexte, nous proposons un outil de prototypage rapide visant ce type d'architectures. Cet outil se base sur une extension que nous proposons de la méthodologie Adéquation Algorithme Architecture (AAA). Il permet d'effectuer automatiquement le partitionnement et l'ordonnancement optimisés des opérations de l'application sur les composants de l'architecture cible et la génération automatique des codes correspondants. Nous avons utilisé cet outil pour l'implantation de l'estimateur de mouvement de la norme H.264/AVC sur une architecture composée d'un processeur NIOS II d'Altera et d'un FPGA Stratix III. Ainsi nous avons pu vérifier le bon fonctionnement de notre outil et validé notre générateur automatique de code mixte / Mixed architectures containing programmable devices and reconfigurable ones can provide calculation performance necessary to meet constraints of real-time applications. But the implementation and optimization of these applications on this kind of architectures is a complex task that takes a lot of time. In this context, we propose a rapid prototyping tool for this type of architectures. This tool is based on our extension of the Adequacy Algorithm Architecture methodology (AAA). It allows to automatically perform optimized partitioning and scheduling of the application operations on the target architecture components and generation of correspondent codes. We used this tool for the implementation of the motion estimator of the H.264/AVC on an architecture composed of a Nios II processor and Altera Stratix III FPGA. So we were able to verify the correct running of our tool and validate our automatic generator of mixed code

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Dentre as espÃcies produtoras de carragenana a Hypnea musciformis à a bastante comum na costa do nordeste Brasileiro. Embora as propriedades da carragenana da H. musciformis sejam promissoras, suas populaÃÃes naturais sÃo geralmente insuficientes a pressÃo da colheita comercial. O cultivo tem sido uma saÃda para incrementar a produÃÃo mundial de algas. Desta forma, o presente trabalho se propÃs a avaliar o potencial para aquicultura da carragenÃfita Hypnea musciformis (Wulfen) j.v. lamour. (Gigartinales - Rhodophyta). Os experimentos foram realizados na praia de Flecheiras, no litoral do estado do CearÃ, Brasil. Foi avaliado o cultivo da H. musciformis em estruturas long-line, o cultivo foi realizado em diferentes Ãpocas do ano (2007) com comprimentos de substratos variados, em diferentes profundidades, sendo avaliado ainda o rendimento da carragenana produzida por algas cultivadas. As mudas cultivadas obtiveram os melhores ganhos de biomassa apÃs 30, 45 e 60 dias de cultivo, para os meses de setembro à novembro 325,7Â44,2g; 359,4Â51,8g e 411,2Â77,8g respectivamente, com taxa de crescimento diÃrio 6,246%; 0,218% e 0,224% respectivamente. Em relaÃÃo à profundidade de cultivo, as algas apresentaram maior ganho biomassa a 0.2 m de profundidade, com taxas de crescimento diÃrio de 5,38 %. Para o comprimento do substrato de cultivo as cordas com 0,8 m apresentaram os melhores resultados, 403,33 g e 616,33g para 30 e 60 dias de cultivo respectivamente. O rendimento de carragenana nÃo apresentou diferenÃas significativas, sendo 32,96 (%) para as algas cultivadas e 32,74 (%) para algas dos bancos naturais / Among the species producing the carrageenan Hypnea musciformis is quite common on the northeast coast of Brazil. Although the properties of carrageenan from H. musciformis are promising, their natural populations are generally insufficient pressure from commercial harvest. The crop has been a way to increase the world production of algae. The present study was to evaluate the potential for aquaculture of Hypnea musciformis (Wulfen) jv Lamour. (Gigartinales - Rhodophyta). The experiments were carried on the Flecheiras beach on coast of CearÃ, Brazil. We evaluated the cultivation of H. musciformis in long-line structures, with adjustments as a substrate for the cultivation of this species, the culture was grown in different seasons (2007) substrates with varying lengths at different depths, and rated the performance of the carrageenan produced by grown algae. Seedlings grown obtained the best gains in biomass after 30, 45 and 60 days of cultivation, for the months of September to November 325.7  44.2 g, 359.4  51.8 g and 411.2  77.8 g respectively with daily growth rate 6.246%, 0.218% and 0.224% respectively. In relation to the depth of cultivation, the algae had greater average biomass to 0.2 meters deep, with daily growth rates of 5.38%. For the length of the growth substrate the strings with 0.8 meters showed the best results, 403.33 g and 616.33 g for 30 and 60 days culture respectively. The yield of carrageenan did not show significant differences, 32.96 (%) for algae grown and 32.74 (%) for algae from natural beds

Glycoengineering is a technology that could improve protein therapeutics. While protein glycosylation in general enhances solubility and stability, and reduces aggregation, immunogenicity and proteolysis, specific kinds of glycosylation may also be critical. For example, capping of glycans with N-acetylneuraminic acid (Neu5Ac) maximises circulatory half-life in humans. Moreover, some glycans directly participate in molecular recognition and other aspects of glycoprotein function. Glycoproteins produced by non-human mammalian cells carry glycans capped by N-glycolyl-neuraminic acid rather than Neu5Ac. Yet production in human cell lines is costly and slow, requires specialist facilities, produces low yields and is subject to additional regulations. Hence there is a case for glycoengineering alternative expression systems capable of rapid, low-cost, high-yield glycoprotein production. This report focuses on the glycoengineering of Pichia pastoris, a yeast, to produce recombinant human glycoprotein factor H (FH) bearing human-like glycans. FH is a potent down-regulator of the complement system. Mutations and SNPs in FH result in autoimmune diseases such as atypical haemolytic ureamic syndrome and age-related macular degeneration (AMD). Recombinant FH is an enticing therapeutic candidate for treating AMD, but high doses are required since FH is abundant (200-300 mg l-1) in normal human serum. Human FH (155 kDa), with eight sites of N-linked glycosylation and 40 disulphides, is a challenging target for recombinant production. Yet FH was previously expressed to 10s of milligrams in P. pastoris. In this study, methods were established to confirm that human plasma-derived (h)FH carries predominantly N-linked diantennary disialylated complex-type glycans, with monosialylated diantennary structures and triantennary structures in fucosylated and non-fucosylated forms, contributing to glycan heterogeneity. Functional comparison of native hFH, enzymatically desialylated (DeSia-) hFH and deglycosylated recombinant P. pastoris-produced (DeGly-r)FH showed that DeSia-hFH had the lowest affinity for complement protein C3b, its key target. Moreover, DeSia-hFH binds C3d, an opsonic C3b-breakdown product, whereas native hFH does not. DeSia-hFH had an improved ability to accelerate decay of the C3 convertase (an enzyme that cleaves C3 to C3b) compared to native hFH, but neither was as good as DeGly-rFH in this respect. In contrast, DeGly-rFH had reduced cofactor activity (for factor I-mediated degradation of C3b) compared to native hFH whereas DeSiahFH did not have reduced cofactor activity. These data suggest that sialylation of FH glycans may play a role in stabilising a conformation of circulating FH that is not fully effective, consistent with specificity for self-surfaces and resistance to bacterial hijack. Aiming eventually to produce human-like glycosylated FH in glycoengineered P. pastoris, the SuperMan 5 strain served as a starting point. While conventional strains of P. pastoris put hypermannosylated N-linked glycans on proteins, glycans on SuperMan 5-produced FH were shown to contain just five mannose (Man) residues. In further glycoengineering, and following unsuccessful efforts to use inABLE technology for this purpose, commercially available (GlycoSwitch) vectors were used to introduce genes encoding the glycosyltransferase enzymes N-acetylglucosamine (GlcNAc) transferase I (GnTI) and galactose (Gal) transferase. These catalysed the formation of a hybrid-type glycan containing an N-acetyllactosamine (Gal-β(1,4)-GlcNAc (LacNAc)) antennae on a five-mannose glycan. Then two more GlycoSwitch plasmids, containing genes encoding α-Mannosidase II (ManII) and GnTII, were introduced into P. pastoris to catalyse the formation of a second LacNAc antennae. MALDI-TOF analysis found the glycosylation of this strain to be heterogeneous, containing the humanised diantennary digalactosyl glycan as well as other endogenous yeast glycans. This strain was designated SuperGal. Large-scale expression of rFH with terminally galactosylated complex-type glycans (Gal-rFH) in SuperGal yielded 100s of milligrams of purified Gal-rFH. Yeast-type glycans were enzymatically removed from rFH and the remaining complex-type humanised glycans were sialylated with a recombinant bacterial α(2,6)-sialyltransferase from Photobacterium sp. expressed in E.coli. Purified sialylated (Sia-) and non-sialylated (Gal-) rFH expressed in SuperGal were functionally characterised in vitro using SPR-based assays. In C3b-binding assays Sia-rFH had lower affinity compared to Gal-rFH. Both bound with lower affinity than DeGly-rFH. A similar pattern of binding affinity was seen for C3d. In C3 convertase decay-acceleration assays, all rFH glycoforms performed equally well and had greater activity than hFH. Conversely, Sia-and Gal-rFH were shown to perform equally as well as hFH in CA assays, while all three versions outperformed DeGly-rFH. However, in vivo complement activity assay carried out in a FH-knockout mouse model showed that humanisation of the glycosylation of rFH did not significantly improve activity compared to DeGly-rFH. In addition, analysis of the circulatory half-life of rFH showed that humanisation did not improve half-life. Further engineering steps will be required to increase the complex-type glycan site occupancy on rFH with a view to improving circulatory half-life and efficacy. However, this study represents a significant step forward in developing a therapeutically useful source of rFH.