Orientador: Guilherme de Paula Nogueira / Resumo: Com aumento global da temperatura, compreender como o metabolismo de bovinos se adapta ao estresse térmico, permitirá selecionar animais melhor adaptados ao aumento da temperatura ambiente. Uma das possibilidades é compreender como cada raça responde a esse efeito ambiente. O trabalho objetivou expor ao sol duas raças distintas de bovinos com diferente resistência ao calor e estudar as alterações no metabolismo mitocondrial e comportamental após a exposição ao sol ou não por 60 dias. Foram analisados 23 animais da raça Angus – susceptível ao calor (12 ao sol e 11 sob sombra) e 25 Nelores – tolerantes ao calor (13 ao sol e 12 sob sombra). Após todos os animais passarem por período de adaptação de 60 dias, foram divididos entre os grupos e analisados os parâmetros ambientais (THI, HLI e AHLU), movimentação (por radiotelemetria), concentrações séricas de testosterona e LH por radioimunoensaio, espessura de tecido adiposo subcutâneo por ultrassonografia e atividade enzimática mitocondrial de músculo esquelético do complexo I (NADH oxidoredutase). A atividade mitocondrial foi avaliada em amostras da musculatura do tríceps braquial colhidas por biópsia periodicamente ao longo do experimento. Os parâmetros ambientais caracterizam o desconforto térmico que os animais foram submetidos, principalmente Angus sol com índice de AHLU muito acima de estresse extremo. Os Angus se movimentaram mais que os Nelore durante o período experimental (p<0,05) e os Nelore se movimentaram mais à noite ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cattle farmers are suffering challenges in the animal breeding, consequence of the global increase of the temperature. Understanding how the homeothermic metabolism adapts to the thermal stress, allows the selection of better adapted animals to the of the environmental temperature increase. One of those possibilities is to understand each breed reacts to this ambient effect. The work aimed to expose in the sun two different bovine breeds that have different heat resistance and evaluate the mitochondrial metabolism and behavioral changes during sun exposure. Twenty three Angus - susceptible to heat (12 in the sun and 11 in shadow) and 25 Nellore - heat tolerant (13 in the sun and 12 in shadow) animals were analyzed. After all the animals went through a 60 days adaptation period, the animals were sorted composing the groups and analyzed the environmental parameters, movement (by radiotelemetry) subcutaneous fat thickeness and mitochondrial enzymatic activity from squelectical muscle samples.The activity mitochondria were evaluated by the enzymatic reaction of the compound I (NADH oxidoreductase) in muscular tissue samples that were collected periodically during the experiment. The environmental parameters characterize the thermal discomfort that the animals were subjected to, mainly Angus sun with AHLU index well above extreme stress. The Angus moved more than the Nellore during the experimental period (p <0.05) and the Nellore moved more at night compared to the day (p <0.05).... (Complete abstract click electronic access below) / Doutor

Submitted by GABRIELA DA SILVA FERREIRA (gabrielasf2@hotmail.com) on 2019-01-31T16:47:44Z No. of bitstreams: 1 TESE GABRIELA REAPRESENTAÇÃO.pdf: 1059757 bytes, checksum: 317764f09d9c4d28d72de68078917c1a (MD5) / Approved for entry into archive by Ederson Vasconcelos Pereira null (edersonpereira@fmva.unesp.br) on 2019-02-01T11:42:09Z (GMT) No. of bitstreams: 1 ferreira_gs_dr_araca_int.pdf: 1059757 bytes, checksum: 317764f09d9c4d28d72de68078917c1a (MD5) / Made available in DSpace on 2019-02-01T11:42:09Z (GMT). No. of bitstreams: 1 ferreira_gs_dr_araca_int.pdf: 1059757 bytes, checksum: 317764f09d9c4d28d72de68078917c1a (MD5) Previous issue date: 2019-01-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Com aumento global da temperatura, compreender como o metabolismo de bovinos se adapta ao estresse térmico, permitirá selecionar animais melhor adaptados ao aumento da temperatura ambiente. Uma das possibilidades é compreender como cada raça responde a esse efeito ambiente. O trabalho objetivou expor ao sol duas raças distintas de bovinos com diferente resistência ao calor e estudar as alterações no metabolismo mitocondrial e comportamental após a exposição ao sol ou não por 60 dias. Foram analisados 23 animais da raça Angus – susceptível ao calor (12 ao sol e 11 sob sombra) e 25 Nelores – tolerantes ao calor (13 ao sol e 12 sob sombra). Após todos os animais passarem por período de adaptação de 60 dias, foram divididos entre os grupos e analisados os parâmetros ambientais (THI, HLI e AHLU), movimentação (por radiotelemetria), concentrações séricas de testosterona e LH por radioimunoensaio, espessura de tecido adiposo subcutâneo por ultrassonografia e atividade enzimática mitocondrial de músculo esquelético do complexo I (NADH oxidoredutase). A atividade mitocondrial foi avaliada em amostras da musculatura do tríceps braquial colhidas por biópsia periodicamente ao longo do experimento. Os parâmetros ambientais caracterizam o desconforto térmico que os animais foram submetidos, principalmente Angus sol com índice de AHLU muito acima de estresse extremo. Os Angus se movimentaram mais que os Nelore durante o período experimental (p<0,05) e os Nelore se movimentaram mais à noite em comparação ao dia (p<0,05). As concentrações de testosterona aumentaram do período de adaptação para o experimento para ambas as raças e tratamentos. Os animais da raça Nelore apresentaram maior depósito de gordura subcutânea que os Angus. A atividade mitocondrial aumentou significativamente do período de adaptação (P0) para o experimento (P1) e não diferiu durante o experimento entre as raça e os tratamentos. Animais endotérmicos mantidos em altas temperaturas respondem com adaptações metabólicas e comportamentais mediante o estresse exposto. Os Nelore se movimentam mais à noite quando a temperatura é mais amena e os Angus durante o dia à procura de conforto térmico. A atividade mitocondrial é aumentada devido a alta demanda de ATP provavelmente em repercussão da necessidade de sinalizar biogênese mitocondrial, reparação celular, movimentação e níveis aumentados de testosterona. / Cattle farmers are suffering challenges in the animal breeding, consequence of the global increase of the temperature. Understanding how the homeothermic metabolism adapts to the thermal stress, allows the selection of better adapted animals to the of the environmental temperature increase. One of those possibilities is to understand each breed reacts to this ambient effect. The work aimed to expose in the sun two different bovine breeds that have different heat resistance and evaluate the mitochondrial metabolism and behavioral changes during sun exposure. Twenty three Angus - susceptible to heat (12 in the sun and 11 in shadow) and 25 Nellore - heat tolerant (13 in the sun and 12 in shadow) animals were analyzed. After all the animals went through a 60 days adaptation period, the animals were sorted composing the groups and analyzed the environmental parameters, movement (by radiotelemetry) subcutaneous fat thickeness and mitochondrial enzymatic activity from squelectical muscle samples.The activity mitochondria were evaluated by the enzymatic reaction of the compound I (NADH oxidoreductase) in muscular tissue samples that were collected periodically during the experiment. The environmental parameters characterize the thermal discomfort that the animals were subjected to, mainly Angus sun with AHLU index well above extreme stress. The Angus moved more than the Nellore during the experimental period (p <0.05) and the Nellore moved more at night compared to the day (p <0.05). Testosterone concentrations increased from the adaptation period to the experimental for both breeds and treatments. The animals of the Nelore breed presented greater subcutaneous fat deposition than the Angus. Enzymatic mitochondrial activity increased significantly from the adaptation period (P0) to the experiment (P1) and did not differ during the experiment between breed and treatments. Homeothermic animals kept at high temperatures respond with metabolic and behavioral adaptations through exposed stress. The Nelore move more at night when the temperature is milder and the Angus during the day looking for thermal comfort. Mitochondrial activity is increased due to high ATP demand probably in repercussion of the need to signal mitochondrial biogenesis, cell repair, movement and increased levels of testosterone.

Muskoxen (<i>Ovibos moschatus</i>) are relatively large herbivores living in an arctic environment where forage is sparse and its availability during long winters is often much reduced by snow and ice. Muskoxen cope by obtaining energy and nutrients from the low-quality sedges and grasses they eat, and from body reserves accumulated in summer and autumn. The objectives of this study were to evaluate the physiological and energetic adaptation of muskoxen to digestion of graminoid forage, and to measure the extent and reproductive significance of seasonal changes in body composition of female muskoxen. The first objective was addressed using two studies with captive muskoxen in Saskatoon, and the second during a field study on Victoria Island, Northwest Territories. In the first study, changes in body weight, intake, retention time and digestibility of a supplemented brome-alfalfa hay were measured in mature muskoxen during two seasonal cycles. Mean daily dry matter intake of breeding females was highest in July and August (62 ± 3.6 g/kg^0.75) then declined slowly to its lowest point in March and April (41 ± 0.7 g/kg^0.75). Mean retention time of hay, calculated from a chromium marker, declined (P<0.01) from 114 ± 4 h in March to 95 ± 4 h in July. Apparent organic matter digestibility decreased (P<0.01) from 74.7 ± 0.8% in winter to 61.7 ± 1.3% in summer. Compared with other ruminants, muskoxen are grazers exceptionally well-suited to slow, thorough digestion of graminoid forage. In the second study, the voluntary intake and apparent digestibility of a low-protein grass hay, similar in composition to diets of wild muskoxen in winter, were measured in five mature muskoxen and three mature Hereford cows during late winter 1993. Both species maintained body weight on the experimental diet but daily dry matter intake of the muskoxen was only 1/3 that of the cattle (32 ± 2 vs. 96 ± 3 g/kg^0.75; P<0.001). Apparent digestibility of organic matter, measured using chromic oxide, was higher in the muskoxen than in the cattle (58 ± 2 [SE] vs. 50 ± 3%; P=0.03). Muskoxen are particularly well adapted to digesting low quality graminoid forage at exceptionally low rates of intake. In the third study, the anatomical and chemical body composition of 22 muskoxen that varied widely in size, age and condition were analysed, and measures of body weight and condition were evaluated as predictors of body composition. The leanest muskoxen were four 5 to 15-day-old calves with 3.5 ± 0.5% (mean ± SE) fat in the IFBW, and the fattest were three females with 24.8 ± 1.4% fat. Muscle weight was best predicted from weights of individual muscles, protein weight from IFBW, bone weight from the weights of individual limb bones, and ash weight from IFBW. Combining kidney fat weight and a measure of body weight with up to three other measurements allowed dissectible and total fat weights to be estimated accurately. The extent of fattening in muskoxen exceeded that found in other wild ruminants with the exception of Svalbard reindeer (<i>Rangifer tarandus platyrhynchus</i>). In the fourth study, the body weight, body composition and reproductive status of 202 muskox cows from Victoria Island were analysed during 16 seasonal collections from 1989 to 1993. Adult muskox cows were lightest and leanest in May, when the ingesta-free body weight (IFBW) of newly-lactating adult cows was 116 ± 2 kg (adjusted mean ± SE) and a similar 112 ± 3 kg in nonlactating cows. Thereafter, the IFBW of lactating cows was virtually unchanged until July, increased rapidly during August, peaked in September at 166 ± 4 kg, then decreased to 148 ± 2 kg in November. In contrast, the IFBW of nonlactating cows increased throughout summer, reached a higher peak in September (176 ± 7 kg; P < 0.01) and changed little by November (164 + 2.1 kg). Pregnancy rates in this population increased from 0 in females 1.5 years old in the autumn to 25% in 2.5 year-olds and 62.5% in cows at least 3.5 years old. Lactation did not appear to peak until at least two months after calving, and was sometimes extended to more than a year. Lactation in November did not preclude pregnancy, but pregnant females at this time were fatter and heavier than nonpregnant cows. These results indicate substantial flexibility in reproductive patterns of muskoxen and an unique ability to maintain condition through long arctic winters. Based on these studies, the persistence of muskoxen through arctic winters can be ascribed in large part to exceptionally low maintenance requirements, along with an ability to thoroughly digest low-quality graminoid forage. Female muskoxen also deposit large quantities of fat in late summer and are able to conserve a large portion of them through early and mid- winter, and use them to support late-winter lactation. Muskox reproductive rates are strongly sensitive to nutritional influences. This suite of K-selected characters in muskoxen is consistent with a slow metabolism and a low rate of population growth.

This thesis is presented as a collection of research papers synthesising knowledge gained during the period of candidacy. Its underlying focus is the examination of evolution from a variety of perspectives for terrestrial arthropods (springtails) in an Antarctic setting. These perspectives include investigation of the ways in which springtail populations respond both physiologically and genetically to environmental variability over historical and contemporary time-scales. While the physiological and genetic may seem two worlds apart, this thesis recognises that, in reality the two are inextricably linked. Thus, when genetic differentiation between populations of the same species can be demonstrated, physiological differentiation of these populations may also be predicted (and vice versa). Therefore, across several locations and springtail species, physiological and genetic parameters of individuals and populations are examined both separately and, where possible, in concert. The physiological aspect of this thesis focuses on the springtail Gomphiocephalus hodgsoni from continental Antarctica. In addition to providing the first metabolic rate data for a continental Antarctic springtail, seasonal variation in metabolic rates is examined across multiple temporal and spatial scales to evaluate the ways in which individuals and populations respond to environmental variability. Metabolic activity in this species is intricately linked to a variety of factors, both intrinsic and extrinsic. These include biological function, temperature profiles in the local microclimate, and body mass and genetic differences among populations. In the genetically-focused aspect of this thesis, population genetic patterns of G. hodgsoni from several continental locations and Cryptopygus antarcticus antarcticus from locations across the Antarctica Peninsula are compared. Here, the importance of differing evolutionary histories in influencing patterns of contemporary genetic population structure is highlighted. While both species have been similarly affected genetically by Pleistocene (2 Ma – present) glacial cycling, it is clear that differences in timing of colonisation events and subsequent population expansions have left distinct genetic signatures in each species. In a separate molecular study, phylogenetic analyses are employed to study members of the circum-Antarctic springtail family Isotomidae. Thesis Abstract The genetic ancestry among these closely related species is shown to reflect a diverse evolutionary origin in the Miocene (23 – 5 Ma), subsequent to which both vicariant and dispersal processes have been important. Phylogenetic re-constructions tease out the relationships among sister species, and the identification of several genetically distant lineages suggests that a revision of current species designations is required. Finally, two studies that integrate the physiological and molecular genetic are presented. First, metabolic rate variation across several locations on sub-Antarctic Marion Island in the springtail Cryptopygus antarcticus travei is examined. This variation is related to the genetic structure of populations to show that historical and contemporary environmental characteristics have left their trace in the expression of both genetic and physiological variability of these populations. Second, the perceived association between metabolic rate and genetic (mutation) rate is investigated more closely - a sophisticated Bayesian correlation analysis detects that there is an indirect relationship between metabolic rate and underlying species phylogeny in C. a. travei. Thus, the physiological and molecular genetic elements of this thesis test or advance important hypotheses within their own fields, and the integrated approach applied is a new step in interpreting evidence of physiological adaptation in Antarctic species. In its multi-faceted approach to evolutionary studies, this thesis enhances understanding of the current picture of springtail evolution in polar environments.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill4 uppsatser.

Orientador: Ana Carolina Pero Vizoto / Resumo: O período de adaptação funcional com as próteses totais novas envolve uma série de problemas transitórios, e este período está diretamente relacionado com o sucesso ou falha do tratamento. O objetivo deste estudo foi avaliar a influência da altura do rebordo mandibular no padrão de movimentos mandibulares, na máxima força de mordida oclusal, na função mastigatória, na ingestão de nutrientes e na satisfação dos pacientes em diferentes estágios após a instalação de próteses totais convencionais novas. Vinte e oito indivíduos desdentados totais (RN, n=14, rebordos mandibulares normais; RR, n=14, rebordos mandibulares reabsorvidos) receberam novas próteses totais convencionais. Um cinesiógrafo foi utilizado para registrar os movimentos mandibulares durante a abertura e fechamento e a mastigação de um alimento teste. A máxima força oclusal foi mensurada com o auxílio de um gnatodinamômetro digital, o desempenho mastigatório foi avaliado por meio do método dos tamises e a habilidade mastigatória pela aplicação de questionário específico baseado em uma escala visual analógica (EVA de 100,0 mm), a satisfação foi avaliada por meio de um questionário. A ingestão de nutrientes foi avaliada por meio de diário alimentar de três dias, e posteriormente foi traduzido em valores nutricionais por meio da utilização da Tabela Brasileira de Composição de Alimentos. Essas avaliações foram conduzidas em momentos distintos: 24 horas, 30 dias, três meses e seis meses após a instalação das próteses t... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Switches play an important regulatory role at all levels of biology, from molecular switches triggering signaling cascades to cellular switches regulating cell maturation and apoptosis. Medical therapies are often designed to toggle a system from one state to another, achieving a specified health outcome. For instance, small doses of subpathologic viruses activate the immune system’s production of antibodies. Electrical stimulation revert cardiac arrhythmias back to normal sinus rhythm. In all of these examples, a major challenge is finding the optimal stimulus waveform necessary to cause the switch to flip. This thesis develops, validates, and applies a novel model-independent stochastic algorithm, the Extrema Distortion Algorithm (EDA), towards finding the optimal stimulus. We validate the EDA’s performance for the Hodgkin-Huxley model (an empirically validated ionic model of neuronal excitability), the FitzHugh-Nagumo model (an abstract model applied to a wide range of biological systems that that exhibit an oscillatory state and a quiescent state), and the genetic toggle switch (a model of bistable gene expression). We show that the EDA is able to not only find the optimal solution, but also in some cases excel beyond the traditional analytic approaches. Finally, we have computed novel optimal stimulus waveforms for aborting epileptic seizures using the EDA in cellular and network models of epilepsy. This work represents a first step in developing a new class of adaptive algorithms and devices that flip biological switches, revealing basic mechanistic insights and therapeutic applications for a broad range of disorders.