Through the 137Cs mass balance method, annual consumption rates were estimated for juvenile Atlantic salmon parr and precocious males, as well as brook trout from 4 sites within the Ste Marguerite river system, Quebec. With explicit age analysis, feeding rates and growth rates were derived on an individual fish and age class basis. These represent the first consumption estimates for Atlantic salmon in the wild. The individual fish approach provided a range of data for a single site, as opposed to a single estimate per age class, allowing for an evaluation of the relationship between consumption and growth for each species or life-history variant. Subsequently, the concept of field maintenance ration was introduced as the intercept of consumption over growth. / Salmonid feeding rates were coupled with density estimates to derive total fish exploitation rates for two streams. The application of age- and site-specific feeding rates derived from the 137Cs mass balance method, solved a long standing paradox in stream ecology as all previously inferred salmonid exploitation rates have been in excess of prey turnover. (Abstract shortened by UMI.)

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Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-07-03T13:32:06Z No. of bitstreams: 1 Elizabete Araujo da Silva.pdf: 800834 bytes, checksum: f73600468106a9a529c7d93d6a6bbdad (MD5) / Made available in DSpace on 2018-07-03T13:32:06Z (GMT). No. of bitstreams: 1 Elizabete Araujo da Silva.pdf: 800834 bytes, checksum: f73600468106a9a529c7d93d6a6bbdad (MD5) Previous issue date: 2018-04-20 / This work aims at investigating how the plot of the play Palhaços, by Timonchenco Wehbi, can be connected to the basic elements of what Peter Brook has called Rough Theatre: a kind of theatre that, beyond merely proposing the centrality of human actions, brings up at its core the search for a critical positioning of artists and public alike. In order to conduct such an endeavour, we will start by reading and analyzing Palhaços to demonstrate how the reflection of artistic procedures is capable of critically influencing both artists and public, and is intrinsic to Wehbi’s dramaturgical architecture. Thus, it would be possible to compare the latter with the ideas about theatre that Peter Brook puts forth in his work The empty space. Finally, we intend to bring light to the fact that the theatre of provocation and contestation (i.e., the rough) is indeed an aesthetic and thematic project of Wehbi's, which we can access through the conversation between an artist, a clown called Careta, and a man from the public, a shoe seller called Benvindo, both of whom are characters in Palhaços / O presente trabalho propõe investigar como o enredo do texto dramatúrgico Palhaços, de Timonchenco Wehbi, pode estar ancorado nos preceitos daquilo que Peter Brook nomeou de Teatro Bruto. Um teatro que, além de se ocupar fundamentalmente das ações humanas, traz em sua essência a busca de um posicionamento crítico do artista e seu público. Para tanto, partiremos da leitura e análise de Palhaços para demonstrar como na peça a reflexão do fazer artístico é intrínseca à arquitetura dramatúrgica proposta por Wehbi e, sendo assim, possível de a aproximarmos das reflexões sobre o teatro que Peter Brook faz em sua obra O espaço vazio. Pretendemos, por fim, evidenciar como o teatro da provocação e da contestação, portanto, o bruto, acaba por ser um projeto estético e temático de Wehbi, ao qual teremos acesso por meio da conversa entre um artista, o palhaço Careta, e um homem vindo do público, o vendedor de sapatos Benvindo, personagens do texto dramatúrgico Palhaços

Microwave-Assisted Thermolysis of ortho-Substituted Aroylsilanes Marc Tremblay Master of Science Department of Chemistry University of Toronto 2008 The microwave-assisted thermolysis of ortho-substituted aroylsilanes has been investigated. When irradiated at 250ºC in DMSO or o‑dichlorobenzene for 10 minutes, aroylsilanes form siloxycarbenes that react following different pathways depending on the solvent and the structure of the starting material. It is shown that in the case of substrates having an O‑allyl or an O‑propargyl chain ortho to the acylsilane, cycloaddition occurs followed by a cascade ring opening to give respectively chroman‑4-one and chromen‑4-one derivatives in up to 66% yield. Among the major competitive pathways were the insertion of the siloxycarbene into allylic C–H bonds and decomposition of the acylsilane group to the corresponding aldehyde, followed by Claisen rearrangement.

Microwave-Assisted Thermolysis of ortho-Substituted Aroylsilanes Marc Tremblay Master of Science Department of Chemistry University of Toronto 2008 The microwave-assisted thermolysis of ortho-substituted aroylsilanes has been investigated. When irradiated at 250ºC in DMSO or o‑dichlorobenzene for 10 minutes, aroylsilanes form siloxycarbenes that react following different pathways depending on the solvent and the structure of the starting material. It is shown that in the case of substrates having an O‑allyl or an O‑propargyl chain ortho to the acylsilane, cycloaddition occurs followed by a cascade ring opening to give respectively chroman‑4-one and chromen‑4-one derivatives in up to 66% yield. Among the major competitive pathways were the insertion of the siloxycarbene into allylic C–H bonds and decomposition of the acylsilane group to the corresponding aldehyde, followed by Claisen rearrangement.

The propensity for animals to migrate can vary markedly among species, populations within species, and individuals within populations. Many taxa displaying variation in migratory behaviour and life history are attracting conservation concern as migratory populations decline in abundance. I developed a conceptual framework for delineating the nature of the broad phenotypic variation observed among and within migratory populations and apply this to Lake Superior brook trout (Salvelinus fontinalis). My literature review of variation in the migratory behaviour of fishes revealed that subsets of the predictions outlined in my framework have been tested for most study systems, but few systems had tested all five predictions. My field studies of Lake Superior brook trout (i) compared isotopic signatures of brook trout sampled from Lake Superior and tributary streams to demonstrate that the fish sampled from the lake and stream differ consistently in habitat use and trophic ecology, (ii) applied age and growth analyses to demonstrate that fish sampled from the lake live longer and grow faster than fish sampled from the streams, with the differences in growth apparent by the end of the first year of life, (iii) used histological measures to demonstrate that fish residing in streams, and exhibiting a stream growth history, reach sexual maturity, and (iv) provided no evidence based on growth histories to suggest that individuals change migratory behaviours later in life. Together, these field studies suggest that partial migration is the best hypothesis to describe the variation observed in the migratory behaviour of brook trout in the Nipigon Bay area of Lake Superior. Although the possibility remains that some individuals could complete their life cycle in the lake. My review and field studies demonstrate that the conceptual framework can be used to help delineate variation in the migratory behaviour exhibited by fishes whose lifetime movements can be difficult to track. / Funding was provided by the Ontario Ministry of Natural Resources through the Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem, Great Lakes Fishery Commission Fishery Research Program, a Natural Science and Engineering Research Council (NSERC) Postgraduate Scholarship, and a NSERC Discovery Grant.

Model organisms are often used in ecotoxicological studies and environmental risk assessments; however, species differences in responses to toxicants exist. A meta-analysis identified normal biomarker ranges for rainbow trout (RT) and brook trout (BT), and showed that RT had greater whole-body lipids and plasma T4 levels than BT. Exposure to selenium inhibited cortisol secretion of trout adrenocortical cells; however, RT were more sensitive than BT. To investigate species vulnerability at the individual level, RT and BT were stocked into reference and selenium-contaminated pit lakes. Fish accumulated more Se from selenium-contaminated than reference lakes, and selenium accumulation was similar between species. Chronic selenium exposure had a greater energetic cost for RT than BT, but this was mitigated by food availability. Chronic selenium exposure decreased plasma T3 and T4 levels, but did not alter other endocrine or oxidative stress biomarkers. This project highlights the need for both species- and site-specific risk assessments. / xiv, 171 leaves : ill., maps ; 29 cm

Mémoire (M.Sc.B.) -- Université du Québec à Chicoutimi, 1992. / Document électronique également accessible en format PDF. CaQCU

Despite the threat of climate change, the physiological mechanisms by which temperature drives the distribution of species are unclear. Here we used chronic temperature exposures to determine that the upper limit for positive growth in the eastern brook trout (Salvelinus fontinalis) is 23.4 °C. Additionally, brook trout exposed to daily temperature oscillations of 8 °C, around a mean of 21 °C, exhibited growth rates that were 43 and 35% lower by length and weight respectively, than in constant 21 °C controls. Limitations in growth were associated with increases in indicators of the physiological stress response. Individuals exposed to 22 or 24 °C for 24 days exhibited plasma cortisol levels that were 12 and 18 fold greater than at 16 °C. Similarly, gill heat shock protein (Hsp)-70 levels were 10.7 and 56 fold higher at 22 and 24 °C than at 16 °C. Brook trout exposed to daily temperature oscillation of 4 or 8 °C had gill Hsp-70 levels that were 40 and 700 fold greater than controls. Acute (6 h) temperature exposures were used to demonstrate a threshold for induction of the Hsp-70 and plasma glucose responses of 20.7 °C and 21.2 °C respectively. Finally, we conducted field surveys that demonstrated increased plasma cortisol, plasma glucose, and gill Hsp-70 at temperatures above 21 °C. Induction of the cellular and endocrine stress responses is associated with decreased growth in brook trout. Thermal limitations on growth may provide a mechanism by which temperature drives the distributions of this cold-water species.

Translocations are an important aspect of the management of natural populations in an increasingly fragmented landscape. Maintaining connectivity and gene flow is beneficial for both contemporary fitness and adaptive potential in the face of environmental change. Genetic rescue (GR) can alleviate inbreeding depression, genetic load, and increase adaptive potential of populations. Here, I have translocated 10 (5 of each sex) brook trout (Salvelinus fontinalis) to four geographically proximate and environmentally similar fragmented stream-dwelling populations of brook trout in Virginia to test for genetic rescue. The translocated brook trout contributed to more families than would be expected under neutral introgression, and hybridization resulted consistently in larger full-sibling family sizes. In the cohort immediately following translocation I observed relatively high (>20%) introgression in 3 of the 4 recipient sites, and in one recipient population 57.7 % of the offspring had at least one migrant parent. During the post-translocation period favorable regional climatic conditions resulted in large cohorts across recipient sites and controls, however the percent increase in juvenile abundance scales to initial genetic diversity and patch size. I observe strong evidence of hybrid vigor through consistently larger body sizes of hybrid offspring. At this point I cannot rule out potential negative effects of translocations such as outbreeding depression with out sampling more cohorts following genetic recombination. However, I provide an empirical and replicated foundation to begin assessing the efficacy of GR-motivated translocations for headwater fish conservation, and make a substantial contribution to the growing body of GR-literature.