Thesis (Ph. D.)--Carleton University, 2004. / Includes bibliographical references (p. 200-217). Also available in electronic format on the Internet.

Orientadores: Denise Vaz de Macedo, Dagmar Ruth Stach-Machado / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:15:50Z (GMT). No. of bitstreams: 1 Ferrucci_DaniloLopes_M.pdf: 1810214 bytes, checksum: 4728c1ea4c33f76583148c1588199a23 (MD5) Previous issue date: 2018-08-15T18:15:37Z / Resumo: Os músculos esqueléticos são constituídos por fibras musculares e pela matriz extracelular. Em resposta ao exercício, o músculo apresenta a habilidade de transformar o estresse mecânico da contração muscular em adaptações de cunho biológico, a esse processo deu-se o nome de mecanotransdução. Embora pouco se saiba sobre a importância da matriz extracelular como mecanoreceptor, trabalhos anteriores mostram que o exercício pode causar alterações na expressão e atividade das metaloproteinases, que podem resultar em modificações na matriz extracelular. Nesse contexto, as MMPs são vistas como pivôs centrais e, através da degradação da matriz extracelular podem gerar fragmentos protéicos com funções distintas das proteínas integras, liberando ainda citocinas e fatores de crescimento associados à matriz, que em interação com receptores celulares fornecem informações à célula sobre o microambiente extracelular, regulando o comportamento e adaptação do tecido. O objetivo do presente estudo foi avaliar o efeito de três sessões diárias de exercício exaustivo, realizados com diferentes pausas recuperativas entre as sessões, grupo E1(1h) e grupo E2 (3h), durante 6 dias consecutivos, na expressão das MMPs 2 e 9 e dos TIMPs 1 e 2; e nas concentrações e atividade biológica das MMPs nas porções vermelha (GV) e branca (GB) do músculo Gastrocnêmio de ratos Wistar. Os animais foram sacrificados após 1°, 3° e 6° dias de exercício e os fragmentos coletados do músculo gastrocnêmio foram analisados via ELISA, zimografia e qRT-PCR. Como controle (C) do protocolo experimental utilizou-se ratos sedentários. Os animais exercitados (E) mostraram aumento de desempenho a partir do 4° dia. Não houve diferença significativa na perfomance dos grupos E1 e E2. Os genes analisados mostraram-se igualmente expressos em resposta ao exercício em ambas as porções do músculo gastrocnêmio, contudo, o grupo E1 apresentou alterações mais acentuadas do que E2 para todos os biomarcadores analisados. O grupo E1 mostrou aumento na expressão das MMPs 2 e 9 no 3° dia de exercício, em ambas as regiões do músculo gastrocnêmio. Com relação aos TIMPs 1 e 2, os dados obtidos demonstram o aumento na expressão no GV e GB em resposta ao exercício (E1 e E2), em todos os tempos experimentais analisados. Todavia esse aumento foi mais acentuado para o grupo E1. A concentração total de MMP-2 nos grupos e E1 e E2 mostrou-se diminuída em todos os períodos analisados, para GV e GB. A atividade das isoformas latente e intermediária da MMP-2 apresentou-se diminuída em ambos os grupos exercitados no GB e apenas no grupo E1 para o GV. A atividade e concentração da MMP-9 não foram detectadas neste estudo. O protocolo agudo utilizado nesse estudo induziu um aumento significativo no desempenho dos animais, independente do tempo de pausa entre as sessões. O efeito adaptativo observado nas MMPs 2 e 9 em GV e GB foi de diminuição quantitativa e qualitativa. Possivelmente o aumento significativo na expressão gênica tanto das MMPs quanto TIMPs no grupo E1, permitiu um remodelamento acelerado na matriz extracelular do tecido, que possibilitou a melhora significativa no desempenho a partir do 3° dia. Considerando que ambos os tempo de pausa foram igualmente eficientes para aumentar a performance, seria melhor utilizar uma pausa de 3h entre as sessões, pois o processo de sinalização de síntese protéica demanda grande quantidade de energia, e depende da oferta de nutrientes em quantidade e qualidade adequada para a resposta / Abstract: Skeletal muscles are composed by muscle fibers and extracellular matrix. In response to exercise, muscles have the ability to transform mechanical stress from their contraction in biological adaptations, and, this process was called echanotransduction. Although little is known about the importance of the extracellular matrix acting as mechanoreceptors in this process, previous studies have shown that exercise can cause changes in the MMPs genetic expression and activity on the extracellular matrix. In this context, MMPs play the central role, once that the extracellular matrix degradation can generate fragments that are bioactive compounds and can interact with cell receptors to provide information regarding to extracellular microenvironment to the cells. Therefore, MMPs can regulate the behavior and adaptation of the muscle. The aims of this study were to evaluate the effect of three daily sessions of exhaustive exercise (performed with different recuperative breaks between sessions for six consecutive days) on the MMP-2, MMP-9 and tissue inhibitors of metalloproteinases 1 and 2 (TIMPs) gene expression, as well as, MMP's concentration and biological activities on the rat gastrocnemius muscle red (RG) and white (WG) portions. The animals were sacrificed on exercise-days 1, 3 and 6 and muscle fragments were collected and stored for later analysis through zymography, ELISA and qRT-PCR. Sedentary rats were used as controls. The exercised animals (E) showed an increased performance from the 4th day (p <0.05). There was no statistical difference between the performance of E1 and E2 groups. The genes examined were similarly expressed in response to exercise on the analyzed muscle regions, however, the group E1 have more pronounced changes than E2 when these biomarkers was analyzed. The E1 showed an increased expression of MMP-2 and -9 on the 3rd day of exercise comparing to the control group for RG e WG. Regarding TIMPs 1 and 2, our data showed an increase on their expression in RG and WG responsive to exercise (E1 and E2) during all time experimental points, but this increase was more pronounced in group E1. Furthermore, total concentration of MMP-2 in both groups was significantly reduced when compared to sedentary animals for all time points and muscle regions. The activity of latent and intermediate MMP-2 isoforms were significantly reduced in both exercised groups in the WG and, only, in the E1 to the RG. MMP-9 concentration and activities were not detected in this study. The acute protocol designed for this study induced an increase in the animal performances, regardless of the pauses employed between sessions. The adaptive effect observed in MMP-2 and 9 in the RG and WG was reduced quantitatively and qualitatively, due to the increased expression of both MMPs and TIMPs in group E1 leading to an accelerated remodeling the gastrocnemius extracellular matrix, allowing a significant improvement on performance since the third day onwards. Considering that both rest periods were equally effective to improve physical performance, rest periods of 3 hours between sessions are more adequate due to processes of protein synthesis, once that demands a great amount of energy and depends on the supply of nutrients in quantity and quality suitable for the positive response / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular

The thermal environment exerts a strong influence on many aspectsof squamate life history. Environmental temperatures constrain daily activity time, fecundity, growth rate, and also influences hatchling phenotype. Cold nest temperatures can slow the development of eggs deposited in the soil, cause developmental abnormalities or result in mortality of embryos.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2006. / Acacia karroo is widespread in southern Africa and displays remarkable phenotypic plasticity over its geographical range. However, it is currently unknown whether this phenomenon is merely phenotypic variation due to environmental variance or whether such plasticity represents adaptation to different habitats (known as adaptive phenotypic plasticity). Adaptive phenotypic plasticity implies that genotypes differ and that there is local adaptation to the local environment. To shed light on this phenomenon, we used a common-garden experiment to investigate among-population variation in plastic responses to simulated rainfall and browsing in two populations originating from contrasting environments, namely arid Karoo (Leeu Gamka) and subtropical coastal forest (Richards Bay). We also studied genetic variation among populations by means of allozyme markers. The results suggest that the populations investigated are both genetically distinct and phenotypically plastic. In addition, there were high levels of polymorphism within populations and great differences in their range of plastic responses to treatments. Of the two populations investigated, the slow-growing one (Leeu Gamka) was phenotypically more plastic with regard to defence-related traits (longer spines, more tannin) while the fast-growing one (Richards Bay) was phenotypically more plastic regarding growth-related traits (taller, with longer leaves). Patterns of performance revealed that the populations have pure strategies of either growth (forest) or defence (arid). The interactions between populations and environments in some traits indicated genetic differentiation in plastic responses between populations and, consequently, that phenotypic plasticity is locally adaptive and not merely due to environmental differences. The two populations appear to have pure strategies; when environmental conditions were improved by addition of water, the forest population increased investment in growth but not defence, while the arid populations increased defence production but not growth.

The unique coral reef at St. Lucie Reef (Stuart, FL) persists despite environmental variability from extensive freshwater discharges, summer upwelling, and thermal instability. By examining the symbiotic zooxanthellae, or Symbiodinium, that reside in corals, we can gain insight to coral physiology impacted by local stressors. Two scleractinian corals, Montastraea cavernosa and Pseudodiploria clivosa were sampled over 1.5 years, including both wet and dry seasons. Zooxanthellae were isolated and quantitatively characterized using standard measurements and molecular techniques. Both coral species varied in zooxanthellae biomass, where Pseudodiploria clivosa had Higher cell densities and chlorophyll concentrations than Montastraea cavernosa. Over time, these parameters varied, but were not significantly altered by fresh water discharge events. Symbiodinium diversity and abundance were identified by ITS2 region amplification and next-generation sequencing .Novel associations between Symbiodinium and each coral explained the observed physiological differences. The symbioses remained stable throughout and could indicate local adaptation for St. Lucie Reef corals. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: p. 161-192.

Thesis (M.S.)--State University of New York at Binghamton, Department of Biological Sciences, 2009. / Includes bibliographical references.

CNPq / A região Sul do Brasil cultiva espécies frutíferas de clima temperado, principalmente pessegueiros, macieiras, videiras e ameixeiras com relativo sucesso. Entretanto, a produção está fortemente vinculada a técnica de quebra de dormência a base de produtos químicos, outrora, proibidos em países importadores de frutas brasileiras. Há necessidade de se conhecer melhor a dinâmica da dormência dessas frutíferas, principalmente do pessegueiro, para que se desenvolva novas técnicas e cultivares adaptadas a regiões subtropicais. O objetivo deste trabalho foi de avaliar e compreender os mecanismos de entrada e saída da dormência de gemas, bem como avaliar o teor de carboidratos nos ramos e nas gemas de pessegueiros das cultivares Santa Áurea e Tropic Beauty, que possuem intermediária e baixa necessidade de frio, respectivamente. Para isso, foram investigadas a evolução do estado de dormência pelo teste de nós isolados e pelo teste de Tabuenca, o estado de hidratação dos tecidos, a atividade da enzima alfa amilase e a concentração de açúcares em diferentes partes de ramos produtivos (brindilas) coletados no período de abril a agosto. Não foi observada instalação de endodormência verdadeira nas gemas de Tropic Beauty e Santa Áurea, também não foi observado período de ecodormência típico, sendo que a paralisação observada é atribuída a paradormência. Os testes biológicos (Teste de um só nó e Teste de Tabuenca) são eficientes em separar as cultivares quanto ao seu estado de dormência. A porção distal dos ramos possui maior ou igual concentração de açúcares solúveis (sacarose, hexoses) que a base, sugerindo que esses possam estar relacionados com a acrotomia, principalmente em Santa Áurea. Não foi observado relação real entre o conteúdo de carboidrato com a dormência, variando conforme a mudança da temperatura ambiente. / The South region of Brazil grows temperate fruit species, especially peaches, apples, vines and plums trees with relative success. However, the production is strongly linked to the rest-breaking chemicals technique, once prohibit in importing countries receiving Brazilian fruits. There is a necessity to know better the dynamics of dormancy of these fruit trees, mainly the peach, for the development of new techniques and cultivars adapted to subtropical regions. The aim of this work was to evaluate and to comprehend the mechanisms of entry and interruption of dormancy of the fruit buds, as well as to evaluate the carbohydrates content in branches and buds of peach trees cultivars Santa Áurea e Tropic Beauty, which have intermediate and low cold necessity, respectively. In this regard, it were investigated the dormancy status evolution using the isolated nodes and Tabuenca tests, the tissues hydration, the alpha-amylase enzyme activity and the sugars concentration in several portions of productive branches collected from April to August. No endodormence period was observed on the buds of Tropic Beauty e Santa Áurea; also, no typical ecodormence period was observed, whereas the observed downtime is attributed to paradormence. The biologic tests (isolated nodes and Tabuenca tests) were efficient on the cultivars division due to their dormancy status. The distal portion of the branches has the higher or equivalent soluble sugars concentration (sucrose, hexoses) than the base, suggesting that they may be related to acrotomy, mainly in Santa Áurea. No real relation among carbohydrates content and dormancy, varying according to the changes in the ambient temperature.

Climatic envelope models focus on the climatic variables affecting species or species assemblages, and are important tools to investigate the effect of climate change on their geographical ranges. These models have largely been proposed in order to make successful predictions on species‘ persistence, determining which variables are likely to induce range expansion, contraction, or shifting. More recent models, including the ability and the cost for individuals to respond promptly to an environmental stimulus, have revealed that species may express phenotypic plasticity able to induce adaptation to the new environment. Consequently, understanding how species evolve to a changing climate is fundamental. From this perspective, investigating intraspecific responses to an environmental variable may contribute to better understanding and prediction of the effect of climate change on the geographical range and evolution of species, particularly in the case of widespread species. In this context, the present study aimed at establishing how environmental variables (focussing mainly on temperature) may have contributed to shape the spatial distribution, physiology, reproductive biology and connectivity of two species of Southern African sandhoppers (Talorchestia capensis and Africorchestia quadrispinosa, Amphipoda, Talitridae). Most of the work was carried out on T. capensis, due to its widespread spatial distribution. A first investigation of the biogeography of T. capensis and A. quadrispinosa, revealed that, for both species, spatial patterns of abundance, size and sex ratio were not explained by the Abundant Centre Hypothesis (greater abundance at the core of a spatial range), but rather guided by bio-physical forces. Precisely, the abundance of sandhoppers was driven by the morphodynamic state of the beach, salinity and temperatures, with strong differentiation among sites that reflected local environmental conditions. In support of these findings, strong population structure in the genetics of T. capensis was found (three main groups) when investigating its phylogeography and genetic connectivity. Although such defined structure may suggests cryptic speciation, the concomitant within-population variation in the COX1 region of mtDNA, also highlighted the importance of individual genetic variability. High individual variability was also found in the response of T. capensis to temperature, both in its physiology (thermal plasticity) and its reproductive biology (maternal effects). Since temperature is one of the main variables affecting the coastal marine systems of southern Africa and the metabolism of animals in general, its effect on the physiology and reproduction of T. capensis was therefore investigated. Thermal responses to increasing/decreasing temperatures were assessed for separated populations of T. capensis. Individual variability was reported in the oxygen consumption of T. capensis in response to temperature (high variation around the means, especially for increasing temperatures). Among population differences in thermal sensitivity were significantly correlated with air temperature variability experienced over the past 23 years, highlighting the importance of historical temperature fluctuations to the current thermal physiology of these sandhoppers. Temperature also had an important effect on the reproductive plasticity of T. capensis. Different temperatures induced mothers to adjust the size of their offspring (i.e. egg size), with larger eggs produced at lower temperatures. Interestingly, females showed strongly significant among individual variation in the size of the eggs. Given the importance of understanding rapid responses of organisms to climate change and considering the fundamental role played by phenotypic plasticity in evolution, the overall study revealed the significance of individual plasticity and variability in response to the environment and highlighted its importance. Particularly, studying the thermal physiology of separated populations and understanding within population reproductive plasticity in response to temperature, helped to clarify how differences among individual responses have important consequences at the population level, possibly explaining the widespread distribution of T. capensis.

Eastern Kingbirds (Tyrannus tyrannus) breed from coast to coast in North America and build open-cup nests in trees. They have been extensively studied across most of their range and have only on occasion been documented to reuse a nest from a previous season. However, at Malheur National Wildlife Refuge (MNWR), located in southeastern Oregon, ~10 % of female Eastern Kingbirds reuse old nests of mainly American Robins (Turdus migratorius). In an attempt to address why nest reuse is so common at MNWR, I used artificial nests to evaluate two hypotheses as to why nest reuse is common in this breeding population. The first hypothesis states that Eastern Kingbirds reuse nests to save time and/or energy (TES) and the second one states nest reuse occurs because there is a shortage of suitable nest sites (NSS). I was able to reject the TES hypothesis because artificial nests provided no apparent reproductive benefits to Eastern Kingbirds, except that if a nest had failed it took less time to lay a replacement clutch after an initial failure if an artificial nest was used instead of building a new nest. A more reasonable explanation is that Eastern Kingbirds face a limited availability of suitable nest sites. With this in mind, I took vegetation measurements to address the hypothesis that Eastern Kingbirds make adaptive choices when selecting a nest site, in which case they would choose sites that increase their probability of breeding successfully. Successful nests, both natural and artificial, were placed higher in a tree and on a steeper angled nest branch than their failed counterparts. Those findings suggest that Eastern Kingbirds make adaptive choices when selecting a nest site.