Coastal dolphins are often exposed to habitat degradation and direct interactions with humans. Major factors that influence dolphin distribution, critical for conservation concerns, are still poorly understood even for the bottlenose dolphin, the best-studied cetacean. To establish the environmental conditions that best predict occurrence of bottlenose dolphins and high feeding densities in Galveston Bay, I conducted a total of 367 boat surveys in five locations of the estuary, totaling 3,814.77 km of search effort. I counted groups of dolphins and measured surface water temperature, salinity, turbidity, total number of boats, shrimp vessels, and number of seabirds. Using geospatial tools, these data -- along with location, distance to the Gulf of Mexico and water depth -- were analyzed on a 500- m resolution grid. Temporal factors at daily and seasonal scales were also examined. Occurrence was modeled using a Generalized Additive Model and core feeding densities (i.e., feeding densities above 2 SD of the mean) were modeled with a Generalized Linear Model. A total of 1,802 dolphins in 262 groups were detected, 56.87% of which were feeding. I found that all factors except warm/cold seasons and turbidity were useful to predict dolphin distribution, which was related non-linearly to most predictors. Fewer variables were relevant in predicting core feeding densities. These were, in decreasing order of relevance, distance to the Gulf of Mexico, surface water temperature, depth, number of boats, and warm/cold seasons. Feeding was highly clustered and the main core areas, less than approximately 3 km2 wide, were stable across time of day and season. The majority of the occurrences (86.2%) and feeding groups (94%) were situated in two bay locations - Galveston Ship Channel (GSC) and Bolivar Roads (BRD) - that amounted to only one- fifth of the surveyed area. Compared to conditions in GSC and BRD when no dolphins were sighted, feeding cores weredeeper and more seabirds were observed. This fine-scale study of bottlenose dolphin distribution may contribute to a better understanding of habitat requirements for coastal dolphins. It also may provide information needed to minimize potential negative impacts to this population caused by human activities.

I investigate aspects of fleet dynamics in a mobile gear, groundfish fishery, on the Scotian Shelf; an area subject to a seasonal area closure. Firstly, the direct impacts of the closure on the redistribution of fishing effort and the resultant catch rates of those “fishing the line” (FTL) were examined. Effort was found to concentrate within 30km of the closure boundary. Two areas of potential FTL strategy were identified, which produced variable catch rate trends. East of the closure, areas of highest catch rate corresponded to areas of greatest effort, while to the west, catch rate was often equalized throughout the region, analogous to the ideal free distribution (IFD). Secondly, two effort distributional models were compared: an IFD-based isodar model and a discrete choice model. The isodar was determined to be the preferred model because of both its consistently superior predictive performance and its greater simplicity.

I investigate aspects of fleet dynamics in a mobile gear, groundfish fishery, on the Scotian Shelf; an area subject to a seasonal area closure. Firstly, the direct impacts of the closure on the redistribution of fishing effort and the resultant catch rates of those “fishing the line” (FTL) were examined. Effort was found to concentrate within 30km of the closure boundary. Two areas of potential FTL strategy were identified, which produced variable catch rate trends. East of the closure, areas of highest catch rate corresponded to areas of greatest effort, while to the west, catch rate was often equalized throughout the region, analogous to the ideal free distribution (IFD). Secondly, two effort distributional models were compared: an IFD-based isodar model and a discrete choice model. The isodar was determined to be the preferred model because of both its consistently superior predictive performance and its greater simplicity.

Devido à sua importância em turbulência causada por ondas de deriva e à aplicação com propósitos em diagnósticos de plasma, a investigação de fluxos zonais (ZF) e modos acústicos geodésicos (GAM) tem atraído bastante atenção na literatura em física de plasmas. Nesta tese, primeiramente consideramos efeitos de equilíbrio com rotação poloidal e toroidal nestes modos, posteriormente investigamos efeitos diamagnéticos em GAM a partir de um modelo de dois fluido, no qual incluímos viscosidade paralela de íons e, na parte final, consideramos amortecimento de Landau e efeitos diamagnéticos simultaneamente no estudo de GAM, porém, a partir do modelo girocinético. Efeitos diamagnéticos são causados por termos que envolvem gradientes de densidade e de temperatura provenientes da função Maxwelliana de equilíbrio. O acoplamento entre os harmônicos poloidais, $m = \\pm1$, e as derivadas radiais de quantidades macroscópicas do plasma é responsável pelo aumento no valor da frequência no GAM de alta frequência e pela instabilidade no GAM de baixa frequência. Este tipo de instabilidade, que é proporcional à frequência diamagnética de elétrons e à razão entre os gradientes de temperatura e de densidade, é mais propenso a ocorrer em posições radiais em que o fator segurança é alto. Modos geodésicos são fracamente amortecidos devido a um mecânismo não colisional conhecido por amortecimento de Landau, o qual é causado pela interação entre a onda eletrostática e partículas carregadas, íons no caso, e a taxa de amortecimento é maior próximo ao centro da coluna de plasma, onde o fator de segurança assume valores mais baixos. O equilíbrio MHD com rotação foi investigado em três regimes com relação às superfícies magnéticas: isotérmico, adiabático e isométrico. Foi observado que o gradiente de temperatura possui sentido oposto em relação à velocidade de rotação poloidal apenas no regime isométrico. Ao considerar equilíbrio com rotação e superfícies magnéticas isotérmicas e incluir fluxo de calor na equação da energia, observamos que ZF apresentam frequência não-nula, a qual é proporcional à velocidade de rotação poloidal e inversamente proporcional ao fator de segurança. Como direções futuras ressaltamos que é importante considerar efeitos eletromagnéticos, estudar automodos geodésicos e incluir o efeito de partículas aprisionadas para o desenvolvimento da física de ZF e GAM. Tal desenvolvimento beneficiará tanto a área de transporte em tokamaks como a área de diagnósticos, na qual a obtenção do perfil radial da temperatura de íons e do fator de segurança é um dos objetivos. Nesta área, um novo tipo de diagnóstico conhecido como espectroscopia em modos acústicos geodésicos está sendo desenvolvido baseado no estudo de automodos. / Due to the important role in drift wave turbulence and applications for plasma diagnostic purposes, the investigation of zonal flows (ZF) and associated geodesic acoustic modes (GAM) has arisen much attention in the plasma physics literature. In this thesis, first we consider equilibrium poloidal and toroidal rotation effects on these modes using the ideal MHD model, then we investigate diamagnetic effects on GAM using a two fluid model that includes parallel ion viscosity, and, in the final step, we include both Landau damping and diamagnetic effects on the study of GAM within the framework of the gyrokinetic model. By diamagnetic effects we mean the density and temperature radial gradients terms coming from the equilibrium Maxwellian distribution function. The effects caused by the coupling between the $m = \\pm1$ poloidal harmonics and the radial derivatives of equilibrium macroscopic quantities are responsible for an increase in the frequency value of the high frequency GAM and for an instability in the low frequency GAM. This instability, which is proportional to the electron drift frequency and the ratio between ion temperature and density gradients, are more likely to occur in radial positions where the safety factor is high. We observe that geodesic modes are slowly damped by a collisionlees mechanism known as Landau damping which is caused by the wave particle interaction between the eletrostatic potential and the íons. This damping is enhanced near the center of the plasma column, where the safety factor has lower values. Equilibrium MHD with plasma rotation were investigated in three regimes regarding the magnetic surfaces: isotherm, adiabatic and isometric. It is found that the temperature gradient has opposite directions compared to the poloidal rotation only for the isometric regime. By considering equilibrium rotation with isotherm magnetic surfaces and including heat flux we observed that ZF has a non-zero frequency which is proportional to the poloidal velocity and the inverse of the safety factor. For future directions we point out that electromagnetic effects, geodesic eigenmodes and trapped particles physics should be important for the development of the ZF and GAM physics, either in the area of anomalous transport caused by drift wave turbulence or for diagnostic purposes for obtaining the radial profile of the ion temperature and the safety factor. In this area, a new kind of diagnostic known as geodesic acoustic mode spectroscopy is being developing based on the study of eigenmodes.

Made available in DSpace on 2014-06-12T23:17:01Z (GMT). No. of bitstreams: 2 arquivo9095_1.pdf: 2279220 bytes, checksum: 153fced8f4e029f8729ec941a61afa99 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / Solo é a superfície inconsolidada que recobre as rochas e mantém a vida animal e vegetal na Terra. É formado a partir da relação do clima e atividades bióticas, modificadas pela topografia, que atua sobre os materiais originários ao longo de certo período de tempo. Em relação às atividades bióticas, destaca-se a exercida pelos líquens, que possibilitam a sucessão na colonização do substrato rochoso, uma vez que podem viver diretamente sobre as rochas, intemperizando-as. Os líquens quando submetidos a diferentes doses e tipos de radiação, são estimulados a produzir suas substâncias em quantidades diferenciadas daquelas que produziriam sem a intervenção da radiação. O objetivo desta pesquisa foi determinar possíveis mudanças na produção do ácido úsnico (USN) pelo líquen Cladonia substellata, submetido a diferentes doses de radiação gama, e determinar a capacidade quelante desse líquen quando acondicionados sobre rochas calcárias. Amostras com 2,5g de C. substellata foram submetidas a fonte de Co-60-irradiador, taxa de dose de 9,06 Gy.h-1, recebendo doses de 5; 7; 10; 15; 20; 30; 40; 50; 60 e 80 Gy, e acondicionadas em placas de Petri, contendo calcário triturado. Durante todo o tempo de incubação, as amostras liquênicas foram borrifadas com água deionizada três vezes por semana. Amostras do líquen foram coletadas a cada 1, 2; 3; 7; 15; 30; 60 e 90 dias e, analisadas por Cromatografias em Camada Delgada (CCD) e Líquida de Alta Eficiência (CLAE). As amostras rochosas controle (não submetidas aos líquens) e, as que estiveram em contato com a C. substellata irradiada a 10, 30 e 80 Gy foram analisadas por difratometria por raios X. Os resultados apontaram para um aumento na produção do ácido úsnico diretamente proporcional às doses mais altas, até a de 10 Gy. A partir desta, houve uma tendência de redução de produção, até uma biossíntese bastante reduzida aos 80Gy. Isso foi corroborado nos experimentos de difratometria por raios X, que demonstraram ser mais facilmente queladas as amostras de calcário que estavam sob C. substellata irradiada com 10 Gy. A rocha submetida ao líquen irradiado a 80Gy, que apresentou baixos teores de USN, permaneceu de forma similar ao controle. Foi possível concluir que a C. substellata incrementa sua biossíntese de ácido úsnico à medida que aumenta a dose de radiação gama, mas há um limite para tal. A ação quelante do ácido úsnico sobre o calcário foi proporcional ao teor produzido desta substância, o que pode ser extrapolado para condições naturais, onde a radiação excessiva pode influenciar na pedogênese e sucessão ecológica

An essential part of the video game experience are the characters. How the characters are perceived as believable can make or break the immersion of the experience. This paper aims to create a model which can be used as a tool for analysis, designed to measure believability in video game characters. For consistency, we first define the term believability. Using thematic analysis, we aim to evaluate what components are relevant in the design process of a new model. This is achieved by studying three characters from japanese role playing games using two existing models to measure believability in artificial agents, as this hasn't been done in this context in the past. The results show that relevant components in existing models does indeed exist, but they lack some components mirroring feelings and personal development in characters from japanese role playing games. In addition to this, problems arising from the categorization of characters in models designed to measure believability is discovered. Two versions of the new model are presented, one designed to measure characters from various genres, and one designed to specifically measure characters from japanese role playing games. A different approach to categorize video game characters is also presented in the latter version of the new model.

[pt] Esta dissertação apresenta um estudo de validação das estimações dos efeitos da poluição atmosférica na saúde da população quando se utilizam dados com periodicidade de seis dias. O estudo foi realizado utilizando duas abordagens complementares. A primeira consiste em comparar os efeitos estimados a partir da análise de duas séries de morbidade diárias na cidade do Rio de Janeiro com aqueles obtidos particionando-se estas mesmas séries em seis séries distintas, cada qual com periodicidade de seis dias. As estimativas dos efeitos nas series particionadas de seis dias variaram substancialmente em relação à série diária para contagem de internações por doenças respiratórias em crianças. Para a mesma análise feita para a série de idosos, não foram detectadas diferenças tão significativas. Para complementar esta análise, realizou-se um estudo de Monte Carlo considerando diferentes cenários quanto aos padrões de poluição do ar. Os resultados mostraram que quanto maior a quantidade de dia atípicos por mês, maior pode ser a variação entre as estimações das séries diárias e as séries com periodicidade de 6 dias. Ao fim deste trabalho são apresentados resultados utilizando dados reais com periodicidade de 6 dias. Os efeitos estimados de PM10 para doenças respiratórias em crianças foram de 8.1% (IC: 5.4% ; 10.8%) para o dia corrente e 7.3% (IC: 4.5% ; 10.2%) para 1 dia após a exposição à poluição do ar. Para idosos, houve um aumento estatisticamente significativo apenas para o dia corrente de 3.36% (IC: 1.19% ;5.58%). / [en] This dissertation presents a validation study on the analysis of the effect of atmospheric pollution on morbidity using data sampled every sixth day. This has been investigated using two complementary frameworks. We first compared such pollution effects using two morbidity daily time series in Rio de Janeiro city, which have been sampled every sixth day, thus generating, for each series, a set of six sampled series. For the daily counts of hospital events for children due to respiratory diseases the estimated pollution effect for the six sampled series was markedly different from the same effect estimated on the original daily time series, while for elderly people such difference has not been observed. The second part of our analysis was carried over using a Monte Carlo study. Finally we conclude our work presenting risk estimates using real data sampled every six days. The estimated relative risks of particulate material (PM10) on respiratory diseases for inhabitants of Rio de Janeiro city were as follows. For children the risk was estimated in 8.1% (5.4%; 10.8%) for current day exposure and 7.3% (4.5%; 10.2%) for exposition lagging one day. For elderly people it was observed a significant increase on hospital attendances due to pollution on the same day of exposition. and the estimated risk was 3.36% (1.19%; 5.58%).

[pt] Apesar do crescimento exponencial da instalação de novas usinas eólicas nos últimos anos, a matriz energética Brasileira é composta, principalmente, por usinas hidrelétricas. Uma das principais características dos sistemas de geração com predominância hidráulica é a forte dependência dos regimes hidrológicos. Atualmente, o setor elétrico brasileiro utiliza a Energia Natural Afluente para gerar cenários hidrológicos a partir de um modelo PAR. Tal modelo é ajustado a partir dos parâmetros estimados do histórico da série temporal, isto é, não considera quaisquer informações exógenas que possam afetar os regimes hidrológicos e, consequentemente, a produção de energia. Estudos recentes identificaram que o uso de variáveis climáticas na modelagem de séries de afluências nas bacias brasileiras pode servir como fator de diminuição de incertezas devido a existência de correlação entre essas variáveis. Também foram identificados benefícios ao decompor as séries hidrológicas em sinal e ruído e utilizar somente o sinal para a modelagem. Neste contexto, o desenvolvimento de modelos híbridos que combinem técnicas de de composição das séries hidrológicas e modelos de séries temporais com variáveis exógenas são objetos de estudo deste trabalho,assim como o desenvolvimento de modelos que associem tais variáveis de formação-linear e periódica. Essas novas abordagens contemplam o uso das técnicas de decomposição SSA e MSSA em combinação com PAR, a aplicação do modelo PARX e o desenvolvimento do modelo PGAM. Como conclusão tem-se que os modelos aplicados se mostraram eficientes para os objetivos propostos e também apresentaram melhor performance, em alguns casos, quando comparados com modelos já publicados na literatura. / [en] Despite the exponential growth of wind farms in recent years, the Brazilian energy matrix is mainly composed of hydroelectric plants.One of the main characteristics of hydroelectric generation systems is the strong dependence on hydrological regimes. Currently, the Brazilian electric sector uses the Natural Energy In flow to generate hydrological scenarios from a PAR model.Such model is adjusted from the estimated parameters of the time series history, that is, it does not consider any exogenous information that could affect the hydrological regimes and, consequently, the energy production. Recent studies indicate that the use of climatic variables in the modeling of inflow series in the Brazilian basins may serve as a factor to reduce uncertainties due to the existence of correlation between these variables. It was also identified benefits by decomposing hydrological series into signal and noise and using only the signal for modeling. In this context, the development of hybrid models that combine techniques of decomposition of the hydrological series and time series models with exogenous variable are study objects of this work, as well as the development of models that associate such variables in a non-linear and periodic way. These new approaches contemplate the use of SSA and MSSA decomposition techniques in combination with PAR, the application of the PARX and the development of the PGAM model. As conclusion, the applied models were efficient for the proposed objectives and also presented better performance, in some cases, when compared with models already published in the literature.

The genus Eimeria (Apicomplexa, Coccidia) provides a wide range of different species with different hosts to study common and variable features within the genus and its species. A common characteristic of all known Eimeria species is the oocyst, the infectious stage where its life cycle starts and ends. In our study, we utilized Eimeria nieschulzi as a model organism. This rat-specific parasite has complex oocyst morphology and can be transfected and even cultivated in vitro up to the oocyst stage. We wanted to elucidate how the known oocyst wall-forming proteins are preserved in this rodent Eimeria species compared to other Eimeria. In newly obtained genomics data, we were able to identify different gametocyte genes that are orthologous to already known gam genes involved in the oocyst wall formation of avian Eimeria species. These genes appeared putatively as single exon genes, but cDNA analysis showed alternative splicing events in the transcripts. The analysis of the translated sequence revealed different conserved motifs but also dissimilar regions in GAM proteins, as well as polymorphic regions. The occurrence of an underrepresented gam56 gene version suggests the existence of a second distinct E. nieschulzi genotype within the E. nieschulzi Landers isolate that we maintain.

Le système d'upwelling nord-ouest africain au large du Maroc, de la Mauritanie, de la Gambie et du Sénégal est le système le plus productif au monde en termes de productivité primaire. Elle se traduit par une importante biomasse de poissons principalement dominée par les petits poissons pélagiques qui sont les principales ressources vivantes exploitées de la région. Dans un contexte de gestion partagée par plusieurs pays des ressources halieutiques de la région, comprendre les facteurs qui contrôlent la répartition spatiale de ces populations et l'évolution de leurs abondances est un enjeu crucial pour les pêcheries et le développement socio-économique de la région. Le but principal de cette thèse est d'une part de décrire les variations saisonnières et interannuelles de l'environnement marin de l'upwelling des Canaries le long de la Côte nord-ouest de l'Afrique, et d'autre part de relier ces variations avec les dynamiques spatio-temporelles de ces principales espèces d'importance commerciale. Nous avons utilisé différents jeux de données disponibles et développé différentes approches afin d'avoir une vision la plus complète possible du fonctionnement de cet écosystème. Ainsi, nous avons combiné des données satellitaires, des données de campagnes scientifiques acoustiques, des statistiques de pêche et des analyses de formes d'otolithes. Le long des côtes NW africaines (10°-35° N), nos données nous ont permis d'identifier trois régions avec une saisonnalité et une intensité de l'upwelling bien différencié. La région présente une forte variabilité latitudinale et temporelle des conditions environnementales. La partie sud de la zone (~ entre 10° et 24°N) se caractérise par des eaux plus chaudes et plus riche en Chlorophylle-a que la partie nord. La majeure partie de la variabilité des paramètres environnementaux étudiés est due à la saisonnalité (>60%). Au cours de la période d'étude (2002-2012), nous avons noté une tendance significative au réchauffement allant de 0.01°C. à 0.04°C.an-¹ et un renforcement général de l'upwelling, mais une tendance à la baisse de la concentration en Chl a dans l'ensemble de la zone étudiée. Il existe un gradient latitudinal sud-nord de la phénologie du bloom de phytoplancton (période, durée et l'ampleur du bloom). Cependant, il n'y a pas de tendances interannuelles significatives de la phénologie du bloom phytoplanctonique ni de corrélations ou tendances avec les paramètres physiques de l'environnement étudié (SST, indice d'upwelling, vent). L'écosystème du courant des Canaries se caractérise par le couple sardines/sardinelles. L'anchois, bien que présent dans cet écosystème, ne joue pas un rôle aussi important que dans les autres systèmes d'upwelling. Les relations entre les abondances d'anchois, de sardines et de sardinelles avec les paramètres environnementaux ont été étudiées à différentes échelles à l'aide de modèles additifs généralisés (GAM). Les résultats de notre étude indiquent que les variations spatio-temporelles de l'abondance de l'anchois et de la sardinelle sont davantage contrôlées par le gradient thermique que par la productivité biologique. La sardine semble être plus contrôlée par une fenêtre environnementale optimale d'intensité d'upwelling et de température "optimal upwelling and temperature windows". Nous avons pu pour la première fois mettre en évidence l'existence d'une alternance temporelle d'abondance entre l'anchois et la sardine comme cela est connu dans d'autres systèmes d'upwelling. Enfin, pour contribuer à la connaissance sur la structuration des populations de la sardinelle ronde qui préoccupent les scientifiques et les gestionnaires des pêches, nous avons mené une étude sur l'analyse de la forme des otolithes. L'existence possible de plusieurs stocks de sardinelle en lien avec des structures océanographiques ne confortent pas la politique de gestion actuelle qui considère un stock unique au large de la côte NW africaine. / The North West African upwelling system off Morocco, Mauritania, Gambia and Senegal is the most productive system in the world in terms of primary productivity. This productivity results in a large fish biomass dominated by small pelagic fish which are the main living resources exploited in the region. In a context of shared management of fisheries resources by several countries in the region, understanding the factors that control the spatial distribution of populations of small pelagic fish and the evolution of their abundances is a crucial issue for fisheries and the socio-economic development of the region. The main objective of this thesis is to describe the seasonal and interannual variations of the marine environment of the Canary upwelling along the Northwest coast of Africa and to link these variations with the spatio-temporal dynamics of the main small pelagic species of commercial importance of this zone. We have used different sets of data available and developed different approaches in order to have a complete view of the functioning of this ecosystem. Thus, we have combined satellite data, acoustic scientific survey data, fishing statistics and analysis of otolith shapes. Along th NW African coasts ( 10° - 35° N), our data allowed us to identify three regions with a well-differentiated seasonality and intensity of upwelling. The region has a high latitudinal and temporal variability of environmental conditions. The southern part of the zone (between 10° and 24° N) is characterized by warmer and richer Chlorophyll-a waters than the northern part. The majority of the variability of the environmental parameters studied is due to seasonality (> 60%). During the study period (2002-2012), we noted a significant warming trend ranging from 0.01° C to 0.04°C. yr-¹ and a general reinforcement of ipwelling, but a downward trend in Chl a concentration in the whole study area. There is a south-north latitudinal gradient of the phenology of the phytoplankton bloom (period, duration and magnitude of the bloom). However, there are no significant interannual trends in phytoplankton bloom phenology or correlations or trends with the physical parameters of the environment studied (SST, upwelling index, wind). The Canary current ecosystem is characterized by the sardine/ Sardinella pair, Anchovy, althought present in this ecosystem, plays no more important role than in other upwelling systems. The relationships between the abundances of anchovies, sardines and sardinella with environmental parameters have been studied at different scales using generalized additive models (GAM). The results of our study indicate that the spatial and temporal variations of the abundance of anchovy and sardinella are controlled more by the thermal gradient than by the biological productivity. The sardine seems to be more controlled by an "optimal upwelling and temperature windows". We were able for the first time to demonstrate the existence of a temporal alternation of abundance between anchovy and sardine as is known in other upwelling systems. Finally, in order to contribute to the knowledge of population structure of the round sardinella that concern scientists and fisheries managers, we conducted a study of the shape of otoliths. The possible existence of several stocks of sardinella in connection with oceanographic structures do not support the current management policy which considers a single stock off the African NW coast.