Understanding the patterns and processes that create differences among individuals in components of fitness, like the probability of survival or reproductive rates, is essential to our knowledge of population dynamics and for informing conservation efforts. For organisms in seasonal environments, early-breeding individuals regularly attain higher fitness than their late-breeding counterparts. Two primary hypotheses, related to quality and date, have been proposed to explain lower reproductive success of late breeders, but the veracity of these ideas has not been fully resolved. I tested predictions associated with these hypotheses to assess the effects of indices of parental and environmental quality on nestling quality and survival in an insectivorous passerine, the tree swallow (Tachycineta bicolor), at two widely separated breeding locations in western Canada. I combined experiments and statistical modelling of observational data to evaluate two mechanisms proposed to contribute to seasonal decline in environmental quality: an increase in nest parasite abundance and a decrease in food abundance with later breeding dates. A parasite reduction experiment revealed a disproportionate benefit of parasite removal on length of primary feather for early-hatched nestlings, suggesting greater energetic constraints early in the breeding season. Furthermore, late-hatched nestlings from parasite-reduced nests had longer head-bill lengths than their control counterparts, and developed head-bills of similar length to those of early-hatched nestlings. Other than these findings, there were few detectable effects of parasites on nestling size, growth and immunity, as has been reported from several previous studies. Indeed, negative effects of parasites were only apparent when food (i.e., insect) biomass was considered. In a second series of experiments in which parental quality was controlled, I also tested whether food abundance declined during the breeding season, as predicted if environmental conditions deteriorate seasonally (i.e., date). Reduced reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality. Declining insect biomass and enlarged brood sizes resulted in nestlings that were lighter, in poorer body condition, had shorter head-bills, shorter and slower growing ninth primary feathers and that were less likely to survive to fledge. Next, I asked whether results obtained from long-term mark-recapture data corroborated findings of short-term manipulations. I examined seasonal variation in first-year apparent survival to investigate the relative influence of large-, small- and individual-scale factors associated with the quality and date hypotheses. Although parental quality was an important predictor of first-year apparent survival of tree swallows, my results further suggested that quality of parents was not the primary factor influencing seasonal variation in first-year apparent survival. Rather, findings were most consistent with the date hypothesis. The relationship between apparent survival and a direct measurement of environmental quality indicated that annual variation in moisture had important consequences for first-year apparent survival of tree swallows in Saskatchewan. First-year apparent survival probabilities were higher during wet years and wetter conditions are generally linked to greater insect abundance. In British Columbia, nestlings from larger broods were less likely to survive, possibly as a result of receiving less food. Apparent survival probabilities were also higher when food was more abundant. I demonstrated that both parental and environmental quality influenced seasonal variation in fitness-related traits of tree swallows. However, the strongest evidence suggests that environmental quality, and in particular food abundance, had the greatest effect on seasonal variation in nestling quality, reproductive success and first-year apparent survival in tree swallows. My results highlight the importance of considering regional precipitation trends when projecting effects of climate change on demography of aerial insectivores.

Evapotranspiration ET is a dominant Earth System process that couples the water and energy cycles at the earth surface. The pressure of global environmental changes foster the broad scientific aim to understand impacts of climate and land-use on evapotranspiration under transient conditions. In this work, the spatial scale of river catchments is addressed through data analysis of hydrological and meteorological archives with ET classically derived through water balance closure. Through a synthesis of various catchments with different climatic forcings and hydrological conditions, the core objectives of this thesis are: - Did environmental changes in the past, such as climatic- or land-use and land cover (LULC) changes, result in detectable non-stationary changes in the hydro-climate time series? - How can the impacts of climatic- from LULC changes on the hydroclimatology of catchments be separated? - What are the factors that control the sensitivity of ET and streamflow to external changes? These research questions are addressed for the climatic scales of long-term annual averages and seasonal conditions which characterise the hydroclimatology of river catchments. Illustrated by a rich hydro-climatic archive condensed for 27 small to medium sized river catchments in Saxony, a method is proposed to analyse the seasonal features of river flow allowing to detect shifting seasons in snow affected river basins in the last 90 years. Observations of snow depth at these same times lead to the conclusion, that changes in the annual cycle of air temperature have a large influence on the timing of the freeze-thaw in late winter and early spring. This causes large changes in storage of water in the snow pack, which leads to profound changes of the river regime, particularly affecting the river flow in the following months. A model-based data analysis, based on the fundamental principles of water and energy conservation for long-term average conditions, is proposed for the prediction of ET and streamflow, as well as the separation of climate related impacts from impacts resulting from changes in basin conditions. The framework was tested on a large data set of river catchments in the continental US and is shown to be consistent with other methods proposed in the literature. The observed past changes highlight that (i) changes in climate, such as precipitation or evaporative demand, result in changes of the partitioning within the water and energy balance, (ii) the aridity of the climate and to a lesser degree basin conditions determine the sensitivity to external changes, (iii) these controlling factors influence the direction of LULC change impacts, which in some cases can be larger than climate impacts. This work provides evidence, that changes in climatic and land cover conditions can lead to transient hydrological behaviours and make stationary assumptions invalid. Hence, past changes present the opportunity for model testing and thereby deriving fundamental laws and concepts at the scale of interest, which are not affected by changes in the boundary conditions. / Die Verdunstung ist ein maßgeblicher Prozess innerhalb des Klimasystems der Erde, welche den Wasserkreislauf mit dem Energiehaushalt der Erde verbindet. Eine zentrale wissenschaftliche Herausforderung ist, zu verstehen, wie die regionale Wasserverfügbarkeit durch Änderungen des Klimas oder der physiographischen Eigenschaften der Landoberfläche beeinflusst wird. Mittels einer integrierten Datenanalyse von vorhandenen langjährigen Archiven hydroklimatischer Zeitreihen werden die folgenden wissenschaftlichen Fragestellungen dieser Dissertation diskutiert: - Haben beobachtete Änderungen der Landoberfläche und des Klimas zu nachweisbaren, instationären hydroklimatischen Änderungen geführt? - Lassen sich die hydroklimatischen Auswirkungen von Klimaänderungen und Änderungen der Landoberfläche voneinander unterscheiden? - Welche Faktoren beeinflussen die Sensitivität von Abfluss und Verdunstung auf Veränderungen der klimatischen und physiographischen Randbedingungen? Hierbei fokussiert sich die Arbeit auf Änderungen im langjährige Mittel und im Jahresgang von hydroklimatischen Variablen auf der räumlichen Skala von Flusseinzugsgebieten. Zur Untersuchung des hydrologischen Regimes wurde ein harmonischer Filter angewandt, der es erlaubt, die Eintrittszeit des Jahresgangs (Phase) zu quantifizieren. Diese klimatologische Kenngröße wurde für eine Vielzahl von Einzugsgebieten in Sachsen untersucht, wobei sich vor allem für die Gebiete in den Kammlagen des Erzgebirges signifikante Veränderungen ergaben. Es konnte gezeigt werden, dass die signifikante Phasenverschiebung der Temperatur seit Ende der 1980er Jahre zu einer verfrühten Schneeschmelze und dadurch zu einem Rückgang des Abflusses bis in die Sommermonate hinein geführt hat. Desweiteren wurde eine modellbasierte Datenanalyse entwickelt, welche auf Massen- und Energieerhalt von Einzugsgebieten im langjährigen Mittel beruht. Das entwickelte Konzept erlaubt es, Auswirkungen von Klimaänderungen von anderen Effekten, welche z.B. durch Landnutzungsänderungen bedingt sind, abzugrenzen und zu quantifizieren. Die Ergebnisse einer Sensitivitätsanalyse dieses Konzeptes sowie die Anwendung auf einen umfangreichen hydroklimatischen Datensatz der USA zeigen: (i) Veränderungen im Wasser- oder Energiedargebot beeinflussen auch die Aufteilung der Wasser- und Energieflüsse. (ii) Die Aridität des Klimas und nachgeordnet die physiographischen Faktoren bestimmen die Sensitivität von Verdunstung und Abfluss. (iii) Beide Faktoren beeinflussen die Stärke und Richtung der Auswirkungen von physiographischen Änderungen. (iv) Anthropogene Veränderungen der Landoberfläche führten zum Teil zu stärkeren Auswirkungen als klimatisch bedingte Änderungen. Zusammenfassend zeigt sich, dass Änderungen von Landnutzung und Klima zu Verschiebungen im Wasserhaushalt führen können und damit auch die Annahme von Stationarität verletzen. Hydroklimatische Veränderungen bieten aber auch eine Gelegenheit zum Testen von Theorien und Modellen, um somit die grundlegenden Zusammenhänge zu erkennen, welche nicht durch Änderungen der Randbedingungen hinfällig werden.

Climate change and population growth is putting increased pressure on water supply. However, detailed water-balance information, which would assist with management is lacking for major reservoirs around the world. This information is particularly critical in mid-latitude northern Mediterranean climates where evaporation is a potentially important water-balance component. This study examines the seasonality of the water balance for the Sooke Reservoir in western Canada, a major water supply for the City of Victoria, British Columbia. Evaporation is estimated with three evaporation models, Penman, Priestley-Taylor, and Hamon and the results are compared. Inflows are estimated with the contributing-area approach and the HBV-EC, hydrologic model. Finally, a worst-case drought scenario is created. If conditions of low precipitation and high evaporation like those found in the study period were to persist, water levels would become critically low during the third dry season and by the fifth season if water restrictions were put in place.

Objectives To prevent economic problems by high wild boar populations, an effective and biologically based wild boar management has to be established. A lot of wild boar research has been done in the last decades. However, game managers were not able to incorporate this knowledge into the development of effective management strategies. Thus, furthermore studies have to be accomplished to expand wild boar science and management. This thesis, based on a radiotelemetric study in southwestern Mecklenburg–Western Pomerania, presents research results on wild boar space use patterns, dispersal, grouping patterns and divisions. For all these measures I examined the influence of age classes and environmental factors affecting behavioural patterns (e.g. hunting, seasonal resources, seasonal requirements). Finally, I discussed efficiency and amount of hunting pressure of different hunting methods. Results The wild boar groups divided temporarily in 12.3 % of all observed localisations. We defined four types of divisions: short-term local, short-term extensive, long-term extensive and final division. The small home range sizes did not differ between age classes or group types with a slight tendency for larger home ranges of yearlings, especially in summer. The shift of summer home ranges was stronger in yearlings than in adults. Three space use patterns occurred in summer: field sows, commuters and forest sows. Only 15 % of all shot animals were shot outside their mothers’ home range, only one fourth of these “dispersed” animals were females. Males were shot at larger distances than females. Diurnal activity was positively influenced by daytime length, nutritional needs and fewer disturbances. Due to this reasons an impact of hunting was not clearly detectable. Hunting did influence activity and space use only in moderate intensities. Single hunt from hides is the dominating and an efficient hunting method. The sustainable harvest rate was not exhausted. Conclusions The small home ranges and low, male biased, dispersal rates denote strong site fidelity in all age and reproductive classes within female wild boar. The short distances and low dispersal rates, even within males, might be affected by all year round equably distributed high abundance of resources. Changed space use patterns in summer are mainly influenced by changed food availability. Although hunting was often presumed to be responsible for behavioural changes, little direct influences were observed in this study. The results reflect an interaction between habitat types, season, and nutritional needs on most behavioural patterns. Sound nutritional conditions and year-round low hunting pressure might be responsible for similar seasonal home ranges. Group fluctuations, occurrence of sub-groups as well as temporary and final divisions seem to be common behavioural patterns within wild boar groups, depending on age classes, reproduction, and seasonal nutritional supplies. Wild boar groups react flexible on several seasonal internal and extrinsic factors. The omnivore wild boar is enabled easily to adapt to various environments. Its wide eco-ethological plasticity enables the species to colonize new habitats and enlarge its distribution. All over Europe hunting rates seem to be lower than reproduction of wild boar. To reduce populations and thus, damages, supplemental feeding should be reduced and hunting rates have to be increased especially for females, as all age classes of females are highly reproductive. Hunting management is the most important tool for disease and damage control. As all hunting methods caused similar and negligible disturbances in this study, efficiency should get top priority. The combination of different hunting methods is necessary for reduction on comprehensive areas. / Ziele Um ökonomische Probleme durch Schwarzwild zu vermeiden, muss eine effektive und biologisch fundierte Schwarzwildbewirtschaftung etabliert werden. Die Schwarzwildforschung hat sich in den letzten Jahrzehnten stark entwickelt. Trotzdem konnten viele Erkenntnisse nicht in eine effektive Bewirtschaftung umgesetzt werden. Daher sind Untersuchungen zur Erweiterung des Wissens um das Schwarzwild weiterhin wichtig. Diese These, basierend auf einer radiotelemetrischen Studie im südwestlichen Mecklenburg-Vorpommern, präsentiert Ergebnisse zu Raumnutzung, Ausbreitung, Rottenverhalten und –teilungen. Für all diese Verhaltensmuster wurden Einflüsse der Altersklassen und anderer Faktoren wie Bejagung, saisonale Ressourcen und Bedürfnisse untersucht. Abschließend werden Effektivität und Störungseinfluss verschiedener Bejagungsmethoden diskutiert. Ergebnisse In 12,3 % der Lokalisationen waren die Rotten vorübergehend getrennt. Wir haben vier Trennungstypen definiert: kurzzeitig-lokal, kurzzeitig-extensiv, langzeitig-extensiv und final. Die kleinen Streifgebietsgrößen unterschieden sich kaum zwischen Altersklassen und Rottentypen. Überläuferbachen zeigten eine leichte Tendenz zu größeren Sommerstreifgebieten und verlagerten die Sommerstreifgebiete stärker als Familienrotten. Drei Raumnutzungsmuster waren im Sommer offensichtlich: Feldsauen, Pendler und Waldsauen. Lediglich 15 % aller erlegten Tiere wurden außerhalb ihres Mutterstreifgebietes geschossen, nur ein Viertel dieser „abgewanderten“ Tiere waren weiblich. Keiler wurden in größeren Distanzen als Bachen erlegt. Tagaktivität wurde positiv von der Tageslichtlänge, Nahrungsbedarf und geringer Störung beeinflusst. Aufgrund dieser Faktoren war ein Einfluss durch Bejagung nicht klar erkennbar. Bejagung beeinflusste Aktivität und Raumnutzung nur moderat. Die dominierende Jagdart „Einzeljagd auf dem Ansitz“ war durchaus effektiv, dennoch wurde die nachhaltige Zuwachsrate nicht abgeschöpft. Schlüsse Die kleinen Streifgebiete und niedrigen, keilerdominierten Abwanderungsraten deuten eine starke Standorttreue weiblichen Schwarzwildes in allen Altersklassen an. Die niedrige Abwanderung mit gleichzeitig geringen Distanzen, auch bei Keilern, dürfte durch ganzjährig gleichmäßig verteilte besonders günstige Ernährungsbedingungen beeinflusst sein. Unterschiedliche geänderte Raumnutzungsmuster werden vor allem durch unterschiedliche Nahrungsverfügbarkeiten beeinflusst. Obwohl oft Jagddruck als Hauptursache für Verhaltensänderungen angesehen wird, konnten in dieser Untersuchung nur ein geringer Einfluss der Jagd nachgewiesen werden. Die Ergebnisse reflektieren eine Interaktion zwischen Habitattypen, Jahreszeiten und Nahrungsbedarf auf die meisten Verhaltensmuster. Günstige Ernährungsbedingungen und ganzjährig gleichmäßig niedriger Jagddruck könnten für gleich bleibende saisonale Streifgebiete verantwortlich sein. Änderungen in der Rottenstruktur, Auftreten von Teilrotten sowie temporäre und finale Teilungen scheinen normale Verhaltensmuster beim Schwarzwild zu sein, abhängig von Altersklassen, Reproduktion und saisonalem Nahrungsangebot. Schwarzwildrotten reagieren flexibel auf diverse saisonale interne und externe Faktoren. Das omnivoren Schwarzwild ist befähigt, sich schnell an verschiedenste Umwelten anzupassen. Die große öko-ethologische Plastizität ermöglicht es dieser Art neue Lebensräume zu erschließen und sein Verbreitungsgebiet auszudehnen. In ganz Europa scheinen die Jagdstrecken unter der Zuwachsrate des Schwarzwildes zu liegen. Um die Populationen, und damit die Schäden zu reduzieren, müssen Fütterungen reduziert und die Bejagung intensiviert werden. Dieses gilt insbesondere für die Bejagung von weiblichem Schwarzwild, da alle Altersklassen hohe Reproduktionsraten aufweisen. Jagdliche Bewirtschaftung ist das wichtigste Werkzeug zur Bekämpfung von Krankheiten und Wildschäden. Da alle Jagdmethoden in der vorliegenden Studie ähnlich geringe Störungen hervorrufen, sollte die Effektivität in den Vordergrund treten. Die Kombination verschiedener Jagdmethoden und Zusammenarbeit der Jäger ist zwingend erforderlich zur Reduktion der Schwarzwildpopulationen.

O presente trabalho avaliou a variabilidade espacial e temporal de ácidos húmicos (HA) e proteínas (PROT), em uma grande lagoa rasa subtropical. Para tanto, foi usado Cromatógrafo Líquido de Alta Eficiência por Exclusão de Tamanho (HPLC-SEC). Foram incluídas como variáveis explanatórias, carbono orgânico dissolvido (COD), nitrogênio total (NT), nitrogênio total dissolvido (NTD), cor, pH e temperatura. A área de estudo foi a Lagoa Mangueira, uma grande lagoa rasa oligo-mesotrófica inserida ao Sistema Hidrológico do Taim – SHT. As amostras foram coletadas em quatro campanhas, durante o ano de 2010, em dezenove pontos diferentes, compreendendo as zonas litorâneas e pelágica, localizadas no sul, centro e norte da lagoa. Resultados indicaram que a Lagoa Mangueira apresenta heterogeneidade temporal interanual em relação a estas variáveis, ao mesmo tempo que possui um perfil longitudinal homogêneo, não evidenciando um arranjo espacial definido. / The present work evaluated spatial and temporal variability of humic acids (HA) and proteins (PROT) in a large subtropical shallow lake. For this purpose, High Performance Liquid Chromatograph by Size Exclusion (HPLC-SEC) was used. Dissolved organic carbon (DOC), total nitrogen (TN), total dissolved nitrogen (TDN), color, pH and temperature were included as explanatory variables. The study area was Mangueira lake, a large shallow oligo-mesotrophic lake located into the Taim Hydrological System. The samples were collected in four samplings during the year 2010 at nineteen different points, including the littoral and pelagic zones, located in the south, center and north of the lake. Results showed that the Mangueira lake presents interannual temporal heterogeneity in relation to these variables, at the same time that it has a homogeneous longitudinal profile, not evidencing a defined spatial arrangement.

El Niño Southern Oscillation events have global implications both climatologically and socio-economically. One such climatological teleconnection is manifested in the Amundsen Sea region (ASR). The Amundsen sea low (ASL) is the dominant low pressure system located around the ASR and is important to the climate of Western Antarctica. Therefore, it is important to understand the ASL and any phenomena that may affect it. This thesis focuses on the ENSO--ASR teleconnection under El Niño conditions and the mechanism behind it. The ENSO--ASR teleconnection was explored using the UM version 8.4 (HadGEM3) model. Time--slice experiments with various magnitudes of idealised perpetual ENSO events are imposed. Two sets of `switch on' experiments in which tropical Pacific SSTs were ramped up were also carried out to investigate the transient nature of the teleconnection. The seasonality of the ENSO--ASR teleconnection is known from previous studies to be stronger in winter compared to summer. The mechanism behind the seasonality was explored using the time--slice experiments. The seasonality is found to originate from the seasonal differences in the Southern Hemispheric jets. As the subtropical jet is only present in austral winter, Rossby wave source anomalies can only be generated in the mid--latitudes in winter. Furthermore, the propagation of the Rossby waves is not possible in summer due to the strong polar front jet. The lack of the source and propagation in summer explains the weaker ENSO--ASR teleconnection. A flowchart summarising the mechanism was created and then verified by the transient runs. The linearity of the ENSO--ASR teleconnection within El Niño has not been previously investigated. This is mainly due to insufficient reanalysis data available to overcome the high internal variability in the ASR. In this thesis, the linearity of the teleconnection under El Niño is studied using the time--slice runs. The results indicate linearity (within errorbars) for both the summer and winter seasons up to historically maximum El Niños. However, under extreme El Niños (beyond historic records) in winter, the teleconnection is no longer linear. The UPSCALE dataset was used to investigate the effects of horizontal resolution on the simulation of the ASL climatological state and the ENSO--ASR teleconnection. The UPSCALE dataset consists of ensembles of HadGEM3 simulations at three different horizontal resolutions. The high resolution model was found to better simulate the ASL while the low resolution model was found to better simulate the ENSO--ASR teleconnection.

A la frontière entre les industries du divertissement et la production culturelle, grand fournisseur de contenu à l'économie numérique, l'industrie du cinéma soulève des questions intéressantes dans le champ de l'économie et du marketing. Cette thèse répond à trois questions empiriques importantes sur ce sujet à l'aide de différentes méthodes adaptées (économétrie des données de panel, différence-de-différences, économétrie structurelle) et propose un nouveau développement théorique du modèle nested logit. Le premier chapitre étudie l'effet des notes des consommateurs sur Internet, et analyse la complémentarité et la substituabilité de ces notes avec l'information disponible avant la sortie des films en salle. Le deuxième chapitre étudie l'effet redistributif de la loi anti-piratage Hadopi sur les entrées des films en salle, en écartant minutieusement les phénomènes alternatifs pouvant affecter les résultats. Le troisième chapitre considère la saisonnalité dans l'industrie française du cinéma et décompose séparément les entrées des films en salle en le niveau de l'offre (le nombre et la qualité des films), la demande saisonnière sous-jacente, les variations météorologiques, et les promotions nationales en estimant un modèle nested logit à trois étages tenant compte de la congestion des films dans les salles de cinéma. Le modèle est utilisé pour identifier les dates de sortie optimales en fonction des types de film. / At the frontier between entertainment industries and cultural production, vital content provider of digital economy, the motion picture industry raises several interesting questions in the field of economics and marketing. This dissertation tackles three important empirical questions in the motion picture industry using different methods (panel data models, difference-in-differences, and structural econometrics) and brings a new theoretical development about the nested logit model. The first chapter deals with online consumer reviews, also known as electronic word of mouth (eWOM), and focuses on the extent to which prerelease information alters the effect of eWOM on movie sales. The second chapter studies the collateral damages of the French anti-piracy law known as Hadopi on box office performances of movies, by carefully ruling out alternative explanations of the result. The third chapter investigates on seasonality in the French movie industry. The analysis separately identifies and decomposes movie sales into the number and quality of available movies, underlying seasonal demand, weather shocks, and national sales promotion by estimating a three-level nested logit model of weekly demand accounting for congestion on movie theaters' screens. The model is used to identify optimal release periods depending on the types of movie.

Made available in DSpace on 2016-06-02T19:22:56Z (GMT). No. of bitstreams: 1 Retido.pdf: 19733 bytes, checksum: 6aad255badc436a06364517de2344ab6 (MD5) Previous issue date: 2012-04-26 / Universidade Federal de Minas Gerais / The goal of the present study was to determine if nitric oxide (NO) acting on brain of frogs presents an inhibitory tonus on mean arterial blood pressure (MAP) and heart rate (HR) by reducing the sympathetic activity dependent on α and/or β adrenergic receptors during winter and spring/summer seasons. Thus, body temperature and MAP was measured by a telemetry device implanted into the abdominal cavity of American bullfrogs, with the catheter of the device inserted into the left aortic arch for AP and HR measurements. Additionally, blood cell flux was measured using a laser Doppler flowmeter sutured to the pelvic skin to calculate cutaneous vascular condutance (CVC). A guide cannula was implanted into brain lateral ventricle for injections of L-NMMA (non selective NO synthase inhibitor) or mCSF (mock cerebrospinal fluid, vehycle) and a PE cannula was inserted in the femoral vein for bolus injections of adrenergic antagonists, prazosin (α1) and sotalol (β), and agonists, phenylephrine (α1) and isoproterenol (β) or Ringer solution. Animals were maintained at 25 °C during all the experiments. Mean AP, but not HR, was greater during winter than spring/summer. L-NMMA increased MAP, but did not change HR, during both seasons. The pre-treatment with prazosin attenuated and soltalol accentuated the hypertensive effect of LNMMA in both seasons. We conclude that NO seems to act on the brain of frogs as a hypotensive agent via, at least in part, the inhibition of the symphathetic activity dependent on α, and β, adrenergic receptors. / O objetivo do presente trabalho foi determinar se o óxido nítrico (NO) atuando no SNC de rãs apresenta tônus inibitório sobre a pressão arterial média (PAM) e a frequência cardíaca (FC) reduzindo a atividade simpática dependente de receptores a e/ou b adrenérgicos durante o inverno e a primavera/verão. Desta forma, a temperatura corporal e a PAM foram mensuradas por meio de um transmissor de telemetria implantado na cavidade abdominal de rãs-touro, e o cateter do transmissor foi inserido no arco aórtico esquerdo para as medidas de pressão arterial e FC. Adicionalmente, o fluxo de células sanguíneas foi avaliado por meio de um sensor a laser Doppler suturado à pele da região pélvica ventral do animal para as medidas de condutância vascular cutânea (CVC). Uma cânula foi implantada no ventrículo lateral para injeções de L-NMMA (inibidor não seletivo da NOS) ou líquor artificial (veículo) e uma cânula de polietileno PE50 foi inserida na veia femoral para injeções in bolus de antagonistas adrenérgicos, prazosin (α1) e sotalol (β), e agonistas, fenilefrina (α1) e isoproterenol (β) ou solução Ringer. Os animais foram mantidos a 25 °C durante todos os experimentos. A PAM, mas não a FC, foi maior no inverno em relação à primavera/verão. A CVC da região pélvica ventral foi maior no inverno em relação à primavera/verão. O L-NMMA aumentou a PAM e diminuiu a CVC, mas não alterou a FC, durante ambas as estações. O pré-tratamento com prazosin atenuou e o sotalol acentuou o efeito pressor do L-NMMA em ambas as estações. Podemos concluir que o NO parece atuar no encéfalo de rãs como um agente hipotensor via, em parte, inibição da atividade simpática dependente de receptores alfa vasoconstritores e beta adrenérgicos vasodilatadores.

This thesis analyzes the monthly data from historical series of the heat stroke cycles, solar radiation and average wind speeds in the 1961 and 2008 period to identify long-term inaccuracies in the location of both wind and solar sources. The state of Rio Grande do Sul-Brazil, was chosen as a case study, to estimate the behavioral trend of these variables and compare them with the measured data, testing the homogeneity of information. Therefore, it aims at improving the long-term prognosis in locating projects of solar power generation plants. The analysis of these climatic variables was carried out using ARIMA models (autoregressive integrated moving average models) as well as the Box & Jenkins methodology and seasonality studies with the X11 ARIMA models with 5% statistical significance. In this study, the period between 1961 and 2011 indicated that heat stroke rates were not enough to overcome the values recorded in the 1960s and 1970s, when the percentages were in most months 1% below the historical average. The observed heat stroke data suggest decreasing trends in the 1980s and 1990s, due to the presence of the phenomenon called "global dimming", which contributed to lower levels of solar radiation.!A possible structural break has been found in the wind series from August 2001 through the CUSUMQ test (cumulative sum of squares of recursive waste) and the Lane et al test. (2002), leading to higher values and overestimating the final prognosis of wind power. A decrease in the average wind speed was also observed from 2003 to 2011 during six months of these years.!The spring season, often with the highest wind potential had the highest mean decrease while the season with the lowest wind potential, fall, had the opposite behavior during the studied period. By spectral analysis, performed by Fourier method, the time series of sunshine and solar radiation also showed cycles with possible ranges of influence on measurements of the solar energy potential. Such temporal variations in the data, indicate that possible locations for the wind and photovoltaic plants may be seriously affected since longterm weather fluctuations can vary significantly even at the best location selected to generate electricity. / Esta tese analisa os dados mensais das séries históricas dos ciclos de insolação, radiação solar e velocidade média dos ventos para melhorar o prognóstico de longo prazo na localização de áreas para fontes eólicas e solares de geração de potência elétrica. Como estudo de caso, tomou-se o período de dados de 1961 a 2008 para definir imprecisões de longo prazo que podem ocorrer no estado do Rio Grande do Sul, Brasil, na estimativa da tendência comportamental das variáveis meteorológicas e compará-las com dados medidos, testando assim, a homogeneidade das informações. As análises das variáveis climáticas foram realizadas através de modelos ARIMA (modelos autorregressivos integrados de média móvel), por meio da metodologia Box & Jenkins e do estudo da sazonalidade com modelos X11 ARIMA em níveis de significância estatística de 5%. Neste estudo, o período entre 1961 e 2011 indicou que os índices de insolação não foram suficientes para superar os valores verificados nas décadas de 1960 e 1970, em que os percentuais foram na maioria dos meses da ordem de -1% abaixo da média histórica. Os dados observados da insolação sugerem tendências decrescentes nas décadas de 1980 e 1990, pela presença do fenômeno global dimming sobre o estado do Rio Grande do Sul contribuindo para menores níveis de radiação solar. Foi constatada também uma possível quebra estrutural na série eólica em agosto de 2001 através do teste CUSUMQ (soma acumulada dos quadrados dos resíduos recursivos) e do teste de Lane et al. (2002), conduzindo a valores maiores e superestimando o prognóstico final do potencial eólico. Também foi constatada, redução em seis dos doze meses do ano na velocidade média dos ventos no período de 2003 a 2011. A estação da primavera, geralmente com o maior potencial eólico, indicou uma maior média de redução enquanto a estação de menor potencial eólico, o outono, mostrou um comportamento inverso para este mesmo período. Através da análise espectral, realizada pelo método de Fourier, as séries históricas de insolação e radiação solar mostraram também ciclos com amplitudes possíveis de influenciar as mensurações do potencial energético solar. Com estas variações temporais nos dados, as previsões de localização de centrais eólicas e fotovoltaicas ficam seriamente prejudicadas, uma vez que as oscilações meteorológicas de longo prazo podem variar sensivelmente na melhor localização de áreas para geração de energia elétrica.

O presente trabalho avaliou a variabilidade espacial e temporal de ácidos húmicos (HA) e proteínas (PROT), em uma grande lagoa rasa subtropical. Para tanto, foi usado Cromatógrafo Líquido de Alta Eficiência por Exclusão de Tamanho (HPLC-SEC). Foram incluídas como variáveis explanatórias, carbono orgânico dissolvido (COD), nitrogênio total (NT), nitrogênio total dissolvido (NTD), cor, pH e temperatura. A área de estudo foi a Lagoa Mangueira, uma grande lagoa rasa oligo-mesotrófica inserida ao Sistema Hidrológico do Taim – SHT. As amostras foram coletadas em quatro campanhas, durante o ano de 2010, em dezenove pontos diferentes, compreendendo as zonas litorâneas e pelágica, localizadas no sul, centro e norte da lagoa. Resultados indicaram que a Lagoa Mangueira apresenta heterogeneidade temporal interanual em relação a estas variáveis, ao mesmo tempo que possui um perfil longitudinal homogêneo, não evidenciando um arranjo espacial definido. / The present work evaluated spatial and temporal variability of humic acids (HA) and proteins (PROT) in a large subtropical shallow lake. For this purpose, High Performance Liquid Chromatograph by Size Exclusion (HPLC-SEC) was used. Dissolved organic carbon (DOC), total nitrogen (TN), total dissolved nitrogen (TDN), color, pH and temperature were included as explanatory variables. The study area was Mangueira lake, a large shallow oligo-mesotrophic lake located into the Taim Hydrological System. The samples were collected in four samplings during the year 2010 at nineteen different points, including the littoral and pelagic zones, located in the south, center and north of the lake. Results showed that the Mangueira lake presents interannual temporal heterogeneity in relation to these variables, at the same time that it has a homogeneous longitudinal profile, not evidencing a defined spatial arrangement.