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Meson spectroscopy aims to study the masses and decay processes of mesons to better understand the mechanics of Quantum Chromo Dynamics in the strong coupling (non peturbative) regime. The Edinburgh group are spokespersons on a major new proposal at the Thomas Jefferson National Laboratory called MesonEx. This experiment will make use of the newly upgraded 12 GeV electron beam and detector systems to produce and measure the properties of mesons of interest for study. Edinburgh also leads the development of a fast timing Hodoscope, part of the new Forward Tagger detector system that will be essential to the success of this experiment. The primary focus of this thesis is the development process of the Foward Tagger Hodoscope, from its inception up to its installation at Jefferson Lab. The second part of the document will discuss the first measurement of the γp → ωππp decay channel, with data from the g11a run of the CLAS (CEBAF Large Acceptance Spectrometer) in Hall B of Jefferson Lab. The analysis presents evidence for resonant contributions to the dataset decaying directly to ωππ, via b1(1235)π or via ωρ. These include a2(1320), π1(1600), ω3(1670) and π2(1670).

The exchange of dissolved constituents between a shallow bay and the ocean is governed by regular tidal fluxes as well as by wind generated storm surges and currents. In this study the transport of a conservative tracer was simulated using the numerical model Delft3D in a system of shallow bays along the coast of the Delmarva Peninsula, Virginia. The evaluation of the tracer residence time was carried out using the Eulerian approach. The main mechanisms governing the decay of the tracer concentration inside the lagoons were assessed by considering the influence of different factors such as the time of release of the tracer with respect to the tidal cycle, tidal amplitude, and local winds. The exponential curve well approximates the decay of the tracer concentration in time. A set of simulations shows that the prevailing factor controlling the tracer transport and, therefore, the tracer concentration within the lagoons are wind-driven fluxes. Large tidal amplitudes also promote the flushing of the tracer out of the bay, while the time of tracer release with respect to the tidal phase has been found to play a relatively negligible role. Finally, a simplified approach is presented to compute the decay of tracer concentration in time. The method accounts for hourly variable wind characteristics as well as seasonal changes in meteorological conditions.

Since post-war reconstruction, Beirut has been experiencing a building boom, which spreadrapidly outward from the city's historic and war-torn centre to the rest of the Lebanese capital. In the process, old houses and buildings have been systematically demolished to make space forlarge towers, excluding much of the urban population. State policies and market forcesconverge to make real estate a pillar of the neoliberal economy, while offering no housing,social or economic policies to redress its gentrifying effects. This thesis scopes the conditions thatproduce decayed residences since the mid-1990s. It asks: What have these circumstancesprompted urban dwellers to do with their houses in decay? How are dwellers in differentpositions of entitlement to property differently enabled to respond to decay and impendingrenewal, in the quest for continued dwelling in the city? What sentiments and strategiesemerge from this interplay? And how have social relationships and notions of dwelling, and ofdecay been reconfigured in the process? From fieldwork among downwardly mobile tenantsand landowners, urban practitioners and a cultural collective in neighbourhoods where urbanrenewal is approaching, I propose, "institutionalised neglect" as a concept to capture thecircumstances that expedite the decay of old houses. I argue that this neglect keeps landavailable for real estate profit making while making urban renewal inevitable. In chaptersthat deal with inheritance, eviction, material decay, nostalgia and the exceptional conditionsof a commoning experiment, I reveal that dwellers' sensibilities are oriented towards prolongeddwelling close to the city centre, whether by endurance of the neoliberal building regime orattempts to extract gains from its straining conditions.

Durante décadas, a visão prevalente em ecologia de microrganismos era de que os fatores ambientais locais seriam os únicos agentes estruturantes das comunidades e dos padrões de coexistência das espécies. Entretando, estudos recentes têm fornecido evidência de que processos ligados a dispersão possam ser tão importantes quanto o ambiente local na estruturação das comunidades, reacendendo o debate em torno da hipótese clássica sobre a ubiquidade dos microrganismos. Neste estudo, nós examinamos os padrões de coexistência do fitoplâncton e os possíveis determinantes da variação espacial na composição das comunidades em 9 lagoas do sul do Brasil. Nós testamos se as espécies fitoplanctônicas apresentam um padrão não aleatório de coexistência através de um modelo nulo e se distância espacial ou a distância ambiental possuem relação com a similaridade na composição das comunidades. Nós também investigamos se as variáveis ambientais locais são bons preditores da abundância das espécies. Na análise de coexistência, nós não observamos um padrão significativo de estruturação dentro das lagoas, mas encontramos um padrão não-aleatório e segregado das espécies ao longo das lagoas, indicando que as espécies coexistem menos do que o esperado ao acaso nesta escala. A similaridade na composição das comunidades mostrou correlação significativa com a distância ambiental, mas não foi correlacionada com a distância geográfica entre os sítios. Além disso, a variação na abundância das espécies apresentou correlação significativa com as variáveis ambientais locais (transparência da água, condutividade, nitrato e ortofosfato). Em conclusão, nossos resultados apoiam a visão de que a variação espacial do fitoplâncton é melhor explicada pelo ambiente local. Nós não testamos a influência de variáveis históricas e filogenéticas sobre esses padrões, que podem ser temas de estudos futuros, a fim de elucidar ainda mais essas questões. / For decades, the main hypothesis in microbial ecology was that local environment would be the only mechanism structuring communities and patterns of species coexistence. However, recent studies have provided evidence that processes related to dispersion can be as important as the local environment for shaping biological communities, stimulating new debates on the classical hypothesis about the ubiquity of microorganisms. In this study, we examined the phytoplankton coexistence patterns and possible determinants of spatial variation in community composition in 9 lakes of southern Brazil. First, we use a null model analysis for tested whether the phytoplankton species show a nonrandom pattern of coexistence. We also tested whether spatial distance or environmental distance act as potential factors controlling community composition. Finally, we investigated whether local environmental variables are good predictors of species abundance. We did not observe a significant pattern of coexistence species in the within-lakes analysis, but we found a nonrandom pattern of coexistence and segregation of species across-lakes analysis, indicating that the species coexist less than expected by chance on this scale. Phytoplankton community composition showed a strong positive correlation with the environmental distance but was not correlated with the geographical distance between sites. Moreover, the variation in the abundance of species showed significant correlation with local environmental variables (water transparency, conductivity, nitrate and orthophosphate). In conclusion, our results support the view that the spatial variation of phytoplankton is best explained by the local environmental conditions. We suggest that the influences of historical and phylogenetic variables on these patterns, here not measured, be analyzed in future studies, to further elucidate these questions.

The purpose of this study was to utilise lignin as a partial substitute for phenol in PF resins. To achieve this, initially brown rot lignin was produced by a bioconversion technique. During the course of the study, it became clear that the production of brown rot lignin had a limited success. Since brown rot lignin could not be obtained in sufficient quantity and purity by a bioconversion method, other alternative lignin production methods, as well as commercially available lignin, were chosen; namely production of lignin from black liquor and Alcell® (organosolv) lignin. Before performing production of resin formulations, the lignin sources were characterised in terms of reactivity and physical properties of lignins. Both lignins had a similar reactivity, but organosolv lignin was found to be more pure, with a low ash content. Since isolation of lignin from black liquor in laboratory conditions is more complex and requires more time, it was decided to use organosolv lignin for subsequent production of lignin-based reSIns. The lignin was introduced to the resin in two different ways. The first method was the replacing of a certain percentage of phenol with lignin (as supplied) directly into resins. In the second method, lignin was modified prior to resin manufacture by phenolation. Different degrees of phenol substitution (from 5% to 60%) were tried for the production of lignin-based resins. Bond qualities of lignin-phenol-formaldehyde (LPF) , phenolated-ligninformaldehyde, commercial phenol-formaldehyde (PF _com) and laboratory made phenol-formaldehyde (PF _made) resins were assessed by using an Automatic Bonding Evaluation System (ABES), prior to production of particleboards, in order to eliminate some of the poor quality resins. The effect of press temperature and time on bond strength appeared to be highly significant, as the lignin substitution levels increased. Up to 30% phenol substitution was achieved without sacrificing bond strength. The bond strength values of phenolated-lignin-formaldehyde resins were similar to commercial phenol-formaldehyde and laboratory made phenolformaldehyde resins, but better than the LPF resins. It was apparent that resins containing a high level of lignin substitution gave the poorest bond strength values. From these results, some of the resins were eliminated, prior to particleboard production. In order to evaluate the quality of lignin-based resins, particleboards were produced and mechanical and physical tests performed. Effect of press platen temperature (140°C, 160°C, 180°C) and press cycle time (5 min, 8 min, IS min) on the mechanical properties of particleboard, produced by using lignin-based resins, were investigated. It was found that particleboards bonded with up to 30% lignin content resins gave similar mechanical and physical properties to commercial phenolformaldehyde resin, as long as a sufficient heating regime and time were applied.

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Durante décadas, a visão prevalente em ecologia de microrganismos era de que os fatores ambientais locais seriam os únicos agentes estruturantes das comunidades e dos padrões de coexistência das espécies. Entretando, estudos recentes têm fornecido evidência de que processos ligados a dispersão possam ser tão importantes quanto o ambiente local na estruturação das comunidades, reacendendo o debate em torno da hipótese clássica sobre a ubiquidade dos microrganismos. Neste estudo, nós examinamos os padrões de coexistência do fitoplâncton e os possíveis determinantes da variação espacial na composição das comunidades em 9 lagoas do sul do Brasil. Nós testamos se as espécies fitoplanctônicas apresentam um padrão não aleatório de coexistência através de um modelo nulo e se distância espacial ou a distância ambiental possuem relação com a similaridade na composição das comunidades. Nós também investigamos se as variáveis ambientais locais são bons preditores da abundância das espécies. Na análise de coexistência, nós não observamos um padrão significativo de estruturação dentro das lagoas, mas encontramos um padrão não-aleatório e segregado das espécies ao longo das lagoas, indicando que as espécies coexistem menos do que o esperado ao acaso nesta escala. A similaridade na composição das comunidades mostrou correlação significativa com a distância ambiental, mas não foi correlacionada com a distância geográfica entre os sítios. Além disso, a variação na abundância das espécies apresentou correlação significativa com as variáveis ambientais locais (transparência da água, condutividade, nitrato e ortofosfato). Em conclusão, nossos resultados apoiam a visão de que a variação espacial do fitoplâncton é melhor explicada pelo ambiente local. Nós não testamos a influência de variáveis históricas e filogenéticas sobre esses padrões, que podem ser temas de estudos futuros, a fim de elucidar ainda mais essas questões. / For decades, the main hypothesis in microbial ecology was that local environment would be the only mechanism structuring communities and patterns of species coexistence. However, recent studies have provided evidence that processes related to dispersion can be as important as the local environment for shaping biological communities, stimulating new debates on the classical hypothesis about the ubiquity of microorganisms. In this study, we examined the phytoplankton coexistence patterns and possible determinants of spatial variation in community composition in 9 lakes of southern Brazil. First, we use a null model analysis for tested whether the phytoplankton species show a nonrandom pattern of coexistence. We also tested whether spatial distance or environmental distance act as potential factors controlling community composition. Finally, we investigated whether local environmental variables are good predictors of species abundance. We did not observe a significant pattern of coexistence species in the within-lakes analysis, but we found a nonrandom pattern of coexistence and segregation of species across-lakes analysis, indicating that the species coexist less than expected by chance on this scale. Phytoplankton community composition showed a strong positive correlation with the environmental distance but was not correlated with the geographical distance between sites. Moreover, the variation in the abundance of species showed significant correlation with local environmental variables (water transparency, conductivity, nitrate and orthophosphate). In conclusion, our results support the view that the spatial variation of phytoplankton is best explained by the local environmental conditions. We suggest that the influences of historical and phylogenetic variables on these patterns, here not measured, be analyzed in future studies, to further elucidate these questions.

Après un cycle de la production des protéines, les sous-unités des ribosomes terminés sont dissociés, afin de les rendre disponibles pour de nouveaux cycles de traduction. Si lors de la traduction le ribosome pause, il ne pourra pas terminer la traduction et être recyclé par la voie classique. Un mécanisme de recyclage alternatif a évolué pour dissocier de tels ribosomes arrêtés. Un complexe composé des facteurs Dom34 et Hbs1 induit leur dissociation. Ce complexe est aussi impliqué dans des voies de contrôle qualité qui ciblent des ARN qui causent des arrêts ribosomiques. Dans cette thèse, l'importance de plusieurs sites fonctionnels du complexe Dom34-Hbs1 pour ces voies contrôle qualité des ARNs est étudiée. De plus, la relation entre ces voies et leurs détails sont examiné. Finalement, un nouveau rôle de Dom34-Hbs1, en dissociant des ribosomes inactifs ce qui rend leurs sous-unités disponibles pour de nouveaux cycles de la traduction, est décrit. / Protein production is a cyclic process that consists of four stages: initiation, elongation, termination and recycling. During recycling the subunits of terminated ribosomes are dissociated, to make them available for new rounds of translation. If ribosomes stall during translation, ribosomes cannot terminate properly and canonical recycling cannot occur. Cells have mechanisms to rescue these stalled ribosomes. A complex formed by the factors Dom34 and Hbs1 induces their dissociation. This compex in RNA quality control, targeting RNAs that cause ribosomal stalling. In this thesis the importance of several functional sites of the Dom34-Hbs1 complex for the degradation of these RNA sis investigated. Details of and therelationship between RNA quality control pathways in which the complex functions are further investigated. Finally, a new role of this complex, dissociating inactive ribosomes and there by making their subunits available to re-enter the translation cycle is described.