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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Rapid Negative Feedback Mechanisms of the Neuroendocrine Stress Response

January 2019 (has links)
archives@tulane.edu / Glucocorticoid-induced negative feedback of the hypothalamic-pituitary-adrenal axis is rapidly achieved by two mechanisms: desensitization of the corticotropin releasing hormone-producing neurons to excitatory noradrenergic inputs by internalization of the α-1 receptor and suppression of excitatory synaptic input via production of an endocannabinoid retrograde messenger. Several previously undetermined signaling factors in the glucocorticoid-induced endocannabinoid release were identified here. The glucocorticoid-induced desensitization to adrenergic receptor signaling was revealed to involve α-1 receptor intracellular trafficking to the late endosome. The physiological significance and therapeutic targets of attenuation of the stress response to noradrenergic inputs was also investigated using electrophysiology and pharmacogenetics. These experiments indicate that desensitization to norepinephrine selectively attenuates the stress response to physiological over psychological stressors. These rapid interactions between glucocorticoids and adrenoreceptor trafficking and endocannabinoid synthesis represent novel glucocorticoid signaling mechanisms through G-protein coupled receptors. / 1 / Grant L. Weiss
2

La llengua catalana a Cocentaina al segle XIII segons el Llibre de la Cort de Justícia

Ponsoda Sanmartín, Joan Josep 02 December 1992 (has links)
No description available.
3

The Effects of Visual Color Stimuli on Zebra Finch Behavior and Stress Response

Ly, Bao Chau 17 December 2014 (has links)
The Australian Zebra Finch, Taeniopygia guttata, is a common vertebrate model for understanding behavioral, neurological, and physiological changes across the life span. The goal of this study was to determine if color in the environment can act as a stimulus and activate the zebra finch stress response. Zebra finches are diurnal and have color vision. Their plumage coloration is sexually dimorphic and they show behavioral changes to color; females prefer males with redder beaks, and both sexes show individual color preferences for materials in nest building. This experiment was conducted to test whether or not a novel color in the environment can elicit a stress response. A colored poster board was introduced to the adult zebra finches’ habitat, and behavioral changes were measured immediately and then again after twenty four hours. In addition, plasma corticosterone (CORT), the main avian stress hormone, concentrations were measured twenty four hours after introduction of the color stimulus. The introduction of the color stimuli resulted in immediate behavioral changes in the birds and increased activity was observed with the addition of green, blue, and red stimuli and decreased activity with the addition of yellow. However, after twenty four hours there were no changes in behavior or plasma CORT levels for any of the colors. These findings suggest that zebra finches show varied behavioral responses to novel stimuli based on color differences and that these changes are temporary.
4

Mathematical Modelling Of Cortisol Response To Exercise

Honnal Venkatesh, Arpitha January 2022 (has links)
Exercise is widely recognized for its role in the health management and prevention of several chronic diseases. Exercise is considered as a stimulus in the form of physical stress to which a group of anatomical structures in the human body responds by generating a stress response that enables certain physiological modifications essential for restoring systemic homeostasis. A major component of the response is produced through the complex hypothalamic-pituitary-adrenal (HPA) axis mechanism that results in the release of cortisol which then intercedes with the effects of the stimulus. To investigate how cortisol helps the body adapt to this physical stress it is necessary to gain deep insight into the cortisol response mechanism. However, this is a complex mechanism, so to better understand the mechanics and to be able to analyze complex data, mathematical models are used. Various mathematical models have already been developed that describe different metabolic responses to exercise but to date, to my knowledge, none of these existing models has illustrated the HPA axis response mechanism, particularly cortisol response to physical exercise. Therefore, I have developed a mathematical model that describes cortisol variations on a normal day in the absence of any form of stress and on the day of exercise. The developed cortisol response model could fit simulation to experimental data and also passed the χ2- statistical test. Additionally, the model has been validated on different cortisol experimental data with satisfying results. At last, considering the positive outcome of this mathematical model, it could be used as a groundwork for developing a comprehensive model which can describe other metabolic processes response to exercise such as glucose metabolism together with the cortisol response mechanism in the future.
5

Physiological and Environmental Processes Influencing Growth Strategies in Amphibian Larvae

Dahl, Emma January 2011 (has links)
Cost and benefits of high individual growth rates are likely to vary across different environments leading to geographic differentiation in growth strategies. In ectotherms, habitats constrained by short growing seasons favour rapid growth and development leading to adaptive latitudinal clines in these traits. Geographic variation in growth strategies should be influenced by physiological variation as well as environmental factors, however many of these mechanisms remain largely unexplored. In my thesis, I studied hormonal correlates of growth strategies, and compensatory responses to phenological variation and environmental stress in anuran tadpoles. I tested the hypotheses that fast growing high latitude common frog Rana temporaria tadpoles have higher growth hormone (GH) expression, and low stress hormone (CORT) elevation in response to predator stress. I found no relationship between GH expression and latitude, but CORT response decreased with latitude after 24 hours of predator exposure. Lower CORT response at high latitude can be adaptive as it may enable the tadpoles to maintain high growth in time constrained habitats. I also found that breeding phenology affected latitudinal variation in growth, development and anti-predator strategies. Northern R. temporaria tadpoles were phenotypically more similar to southern tadpoles when breeding occurred early, suggesting that part of the latitudinal variation is plastic and affected by yearly variation in phenology. When time stress was manipulated by delaying hatching, tadpoles were able to compensate by increasing their development and growth during the larval stage, decreasing the cost of the delayed development. In the final study, I found that northern tadpoles showed stronger compensatory growth during the larval stage than southern tadpoles after being delayed by low food, however, temperature manipulation did not induce differences in the compensatory responses. In general, my results highlight the roles of both environmental and genetic variation in determining individual growth strategies. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 735
6

Palatable solutions do not prevent the memory impairment induced by sleep deprivation in rats

Escobar, Claudia Angélica Bonilla January 2015 (has links)
Orientador: Prof. Dr. Paula Ayako Tiba / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2015. / A privação do sono REM ou privação do sono paradoxal (PSD), em ratos, induz prejuízos cognitivos. Estudos anteriores mostraram que a exposição ao estresse também é capaz de produzir prejuízo, o que pode indicar que o estresse e seus mediadores hormonais poderiam ser responsáveis pelo déficit cognitivo. Anteriormente, foi demonstrado que o fornecimento de soluções palatáveis durante a privação de sono é capaz de reduzir a liberação de ACTH e corticosterona (CORT), hormônios envolvidos na resposta ao stress e, provavelmente, envolvidos no prejuízo cognitivo. No presente estudo, 130 ratos foram divididos em três experimentos: teste de memória, teste hormonal e de palatabilidade. No teste de memória e hormonal, 60 ratos foram divididos em dois grupos: Controle (CTL) e PSD. Foram oferecidas água, sacarose (SAC) (13,5%) ou sucralose (SUC) (6%) para ingestão durante o período de PSD (96h). Ao final da privação de sono, os as concentrações de CORT foram medidas e os animais foram treinados e testados na tarefa de condicionamento do medo ao contexto. Durante o período de PSD, os animais foram pesados diariamente e a ingestão de alimentos e de fluidos foram avaliadas duas vezes por dia. Para o teste de palatabilidade, os animais foram divididos em dois grupos de 5 ratos cada e foi ofertada SUC e água ou solução de SUC e SAC. O consumo total das soluções foi medido durante 4 dias. Em comparação com os seus homólogos CTL, o grupo PSD perdeu peso durante a privação e roeram mais ração do que CTL durante a terceira e quarta noite de PSD. A ingestão de sacarose foi sempre maior em ambos os grupos. Não houve diferença estatística nas concentrações de CORT entre os grupos, mas as concentrações foram altos em comparação com a literatura. Houve prejuízo da memória induzido pela PSD e não houve efeito das soluções palatáveis sobre o comportamento de freezing no teste de condicionamento de medo ao contexto. Houve preferência por soluções de SUC e SAC. Estes resultados sugerem que o comprometimento da memória induzida pela PSD, não é uma consequência dos elevados níveis de CORT e que o eixo HPA desempenha um papel secundário neste fenômeno. / REM sleep deprivation or paradoxical sleep deprivation (PSD) in rats induce cognitive impairment. Previous studies have shown that exposure to stress is also able to produce similar consequences, which may indicate that stress hormonal mediators could be responsible for cognitive deficit in PSD. Previously, it was shown that the supply of palatable solutions during sleep deprivation is able to reduce the release of ACTH and corticosterone, hormones involved in the stress response and allegedly responsible for the cognitive impairment. In the present study, one hundred and thirty rats were divided in three experiments for memory, hormonal and palatability test. On the memory and hormonal test 60 rats were divided in two groups, Control (CTL) and PSD, and were offered water, saccharose (SAC)(13,5%) or sucralose (SUC)(6%) to drink during the PSD (96h). At the end of the sleep deprivation period, CORT levels were measured and the individuals were trained and tested in the contextual fear-conditioning task according to the experiment. During the PSD period they were weighed daily, food and fluid intake were assessed twice a day. For palatability test two groups of 5 rats were offer SUC and Water or SUC and saccharose SAC solution, total intake during 4 days was measure. Compared to their control counterparts, all PSD rats lost weight during the PSD and chewed more than the CTL during the third and fourth night of PSD. Fluid Intake for SAC treatment was always higher compared with the other solutions and during PSD. There was no statistical difference in CORT levels between groups and treatments, but the levels where high compared to the literature. There was memory impairment induced in the PSD group and there was no effect of the palatable solutions on freezing behavior. There was preference for SUC and SAC solutions over water. These suggest that the impairment on memory induce by PSD, is not a consequence of high levels of CORT and that the HPA axis play a secondary role in this phenomenon.
7

Farelo do mesocarpo de babaçu na produção de bovinos de corte / Babassu mesocarp bran in the cattle production

MIOTTO, Fabríca Rocha Chaves 18 August 2011 (has links)
Made available in DSpace on 2014-07-29T15:13:45Z (GMT). No. of bitstreams: 1 Tese parte1 Fabricia Rocha Chaves Miotto.pdf: 8322893 bytes, checksum: e402e3e9bcec9054d69df88cb3b48403 (MD5) Previous issue date: 2011-08-18 / This study aimed to evaluate intake, apparent digestibility of nutrients and nitrogen balance (NB) of diets containing babassu mesocarp bran (BMB) in replacement of elephant grass silage (0, 21, 38, 62 and 78%). Twenty sheep were placed in metabolism crates and allotted to a completely randomized design with four replicates. Were collected and recorded food intake and excretion of feces and urine. The intakes of dry matter (DM), organic matter (OM), crude protein (CP), ash, neutral detergent fibrous (NDF), acid detergent fibrous (ADF), hemicellulose and total carbohydrates were not affected by experimental diets. Change was observed in the intakes of non fibrous carbohydrates (NFC) and reduced intake of ether extract (EE) as % of live weight (%LW) and grams per unit of metabolic weight (g/UMW). The total digestible nutrients TDN intake had a quadratic response with maximum points at 37.3 and 37.9% of BMB when expressed in % LW and g/UMW, respectively. The apparent digestibilities of OM, NDF, ADF, CP and NFC reduced to the extent that the BMB has increased in the diets. The digestibility of DM, EE, and NFC had a quadratic response, where the maximum digestibility of DM was estimated at 10% BMB. TDN decreased 0.28% for each percentage point of inclusion in the diets of BMB. The BMB use reduces the fibrous fractions digestibility, but increases the NFC and TDN intake, indicating that this byproduct can be used as an energy source for ruminant diets. Note: Thesis w/seven chapters. Presented summary and abstract of the 2nd chapter / Objetivou-se avaliar consumo, digestibilidade aparente de nutrientes e balanço de nitrogênio (BN) de dietas contendo farelo de mesocarpo de babaçu (FMB) em substituição à silagem de capim elefante (0; 21; 38; 62 e 78%). Utilizaram-se 20 ovinos alojados em gaiolas metabólicas individuais e distribuídos em delineamento inteiramente casualisado com quatro repetições. Foram coletados e registrados o consumo de alimentos e excreções de fezes e urina. Os consumos de matéria seca (MS), matéria orgânica (MO), proteína brutua (PB), cinza, fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose e carboidratos totais não foram influenciados pelas dietas experimentais. Foi observada alteração nos consumos de carboidratos não fibrosos (CNF) e redução nos consumos de extrato etéreo (EE) em % do PV e em gramas por unidade de tamanho metabólico (g/UTM). O consumo de nutrientes digestíveis totais (NDT) teve comportamento quadrático com pontos de máximo em 37,3 e 37,9% de FMB expressos em %PV e g/UTM, respectivamente. As digestibilidades aparentes da MO, FDN, FDA, PB e CNF reduziram na medida em que o FMB aumentou nas dietas. A digestibilidade da MS, EE e CNF tiveram comportamento quadrático, em que a máxima digestibilidade da MS foi estimada com 10% de FMB. O NDT reduziu 0,28% para cada ponto percentual de inclusão de FMB nas dietas. O uso do FMB reduz a digestibilidade de frações fibrosas, contudo aumenta o consumo de CNF e o consumo de NDT, o que indica que esse subproduto pode ser utilizado como fonte energética para dietas de ruminantes. OBS: Tese c/ sete capítulos. Apresentado resumo e abstract do 2° capítulo.
8

Performance Practice of Interactive Music for Clarinet and Computer with an Examination of Five Works by American Composers

Yoder, Rachel M. 12 1900 (has links)
Since the development of interactive music software in the 1980s, a new genre of works for clarinet and computer has emerged. The rapid proliferation of interactive music resulted in a great deal of experimentation, creating a lack of standardization in both the composition and performance of this repertoire. In addition, many performers are reluctant to approach these works due to unfamiliarity with the genre and its technical and musical considerations. Performance practice commonly refers to interpretation of a written score, but the technology involved in interactive music requires a broader definition of performance practice; one that also addresses computer software, coordination between the performer and computer system, and technology such as microphones and pedals. The problems and potential solutions of interactive music performance practice are explored in this paper through review of the relevant published literature, interviews with experts in the field, and examination of musical examples from works for clarinet and computer by Lippe, May, Pinkston, Rowe, and Welch. Performance practice considerations of interactive music fall into the categories of notation, technology, collaboration, interpretation, and rehearsal. From the interviews and the literature, it is clear that the performance of interactive music requires specific knowledge and skills that performers may not encounter in other genres of contemporary music, including microphone technique, spatialization, sound processing, and improvisation. Performance practice issues are often mediated by close collaboration between performers and composers, but they can inhibit the accessibility of these works to new performers, and may be detrimental to the long-term viability of interactive music. Recommendations for resolving these issues are directed at both composers and performers of interactive music. A listing of over one hundred interactive works for clarinet and computer is also included.
9

CONSTRUCCIONES ESCOLARES EN VALENCIA. 1920-1939

Gómez Alfonso, Carlos José 05 April 2016 (has links)
[EN] ABSTRACT This work aims to compile and to study school buildings which were designed and constructed in Valencia and its province, between the year 1920 and 1939. The period begins in 1920 when the Oficina Técnica de Construcción de Escuelas was founded, given that this measure -together with others of the same moment- supposed a very important change in the mechanisms that the State arranged for the construction of school buildings. The temporary period of this study finishes in 1939, moment in which Spanish II Republic falls. The present work raises five thematic core issues (nudos temáticos) able to establish a framework capable to centering the context from where the school production was developed The second part of this work consists on the specific study of all the schools compiled in Valencia, by means of a systematic analysis, which uses defined variables distilled from the above mentioned core issues. This analysis will allow us to explain some circumstances in a relatively trustworthy way, that is to say we will be able to extract founded conclusions. To be able to study the school buildings in Valencia and to understand the school buildings production in our environment, there has been compiled a great quantity of information about the school buildings designed and constructed, gathered in four annexes in this work. / [ES] RESUMEN Este estudio se plantea como objetivo la recopilación y estudio de los grupos escolares proyectados y construidos en Valencia y su provincia, entre los años 1920 y 1939. El ámbito temporal se inicia en 1920 con la creación de la Oficina Técnica de Construcción de Escuelas, puesto que esta medida junto con otras del mismo momento, suponen un cambio muy importante en los mecanismos que el Estado dispone para la construcción de edificios escolares. El periodo temporal de estudio finaliza en 1939, momento en que cae la II República El estudio plantea cinco nudos temáticos que establecen una trama capaz de centrar el contexto sobre el que se desarrolló la producción escolar. La segunda parte de este trabajo consiste en el estudio específico de todas las escuelas recopiladas en Valencia, mediante un análisis sistemático, destilado de los nudos temáticos a través de las variables definidas. El análisis nos permitirá explicar algunas circunstancias de una manera relativamente fiable, es decir extraeremos conclusiones fundadas. Para poder realizar el estudio de las escuelas en Valencia y entender la producción escolar en nuestro entorno, se ha recopilado una gran cantidad de información sobre los edificios escolares proyectados y construidos, recogida en los cuatro anexos de este trabajo. / [CA] RESUM Aquest treball es planteja com a objectiu la recopilació i estudi dels grups escolars projectats i construïts a València i la seua província, entre els anys 1920 i 1939. El període temporal s'inicia en 1920 amb la creació de la Oficina Técnica de Construcción de Escuelas, ja que aquesta mesura juntament amb unes altres del mateix moment, suposen un canvi molt important en els mecanismes que l'Estat disposa per a la construcció d'edificis escolars. El estudi finalitza en 1939, moment en què cau la II República. El treball planteja cinc nusos temàtics que estableixen una trama capaç de centrar el context sobre el qual es va desenvolupar la producció escolar. La segona part d'aquest treball consisteix en l'estudi específic de totes les escoles recopilades a València, mitjançant una anàlisi sistemàtica, destil¿lat dels nusos temàtics a través de les variables definides. L'anàlisi ens permetrà explicar algunes circumstàncies d'una manera relativament fiable, és a dir extraurem conclusions fonamentades. Per a poder realitzar l'estudi de les escoles a València i entendre la producció escolar en el nostre entorn, s'ha recopilat una gran quantitat d'informació sobre els edificis escolars projectats i construïts, recollida en els quatre annexos d'aquest treball. / Gómez Alfonso, CJ. (2016). CONSTRUCCIONES ESCOLARES EN VALENCIA. 1920-1939 [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62170
10

O efeito como fim : guias da composi??o

Chemello, Maur?cio 02 January 2008 (has links)
Made available in DSpace on 2015-04-14T13:37:37Z (GMT). No. of bitstreams: 1 398247.pdf: 556446 bytes, checksum: f8a8cb9aa35858ee18d047f536ca82b1 (MD5) Previous issue date: 2008-01-02 / A presente disserta??o analisa o pressuposto de que h? uma expectativa do autor em provocar um efeito no leitor. Apresenta-o como parte do processo de composi??o do conto e elemento respons?vel pela qualifica??o do texto liter?rio. O estudo divide-se em tr?s eixos: 1) aspectos do conto; 2) aspectos do efeito; 3) fus?o: o conto e o efeito. Identifica caracter?sticas do conto e o modo como os textos te?ricos analisam o efeito como seu elemento constitutivo. Foram utilizados os estudos de Julio Cort?zar, Ricardo Piglia, Arist?teles e Edgar Allan Poe, al?m da teoria do efeito, de Wolfgang Iser.

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