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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.
41

O empalhador de passarinho, de Mário de Andrade: edição de texto fiel e anotado / The taxidermist finch, by Mário de Andrade: faithfull and annotated text edition

Marina Damasceno de Sá 20 September 2013 (has links)
Esta dissertação de mestrado tem como objeto a edição de texto fiel e anotado de O empalhador de passarinho vigésimo volume das obras completas de Mário de Andrade (1893-1945), publicado pela Livraria Martins Editora em 1946, após sua morte. Apresentando o cotejo entre a edição princeps e as primeiras versões dos artigos em periódicos, esta Edição de texto fiel e anotado dO empalhador de passarinho de Mário de Andrade, inscrita no Programa de Pós-Graduação em Literatura Brasileira da FFLCH-USP, é resultado do projeto temático FAPESP/ IEB e FFLCH-USP, Estudo do processo de criação de Mário de Andrade nos manuscritos de seu arquivo, em sua correspondência, em sua marginália em suas leituras, coordenado, entre 2006-2011, pela Profa. Dra. Telê Ancona Lopez. A partir do confronto documental, realizou-se a confecção de notas que buscam compreender o arte-fazer, operado por Mário de Andrade, das críticas realizadas entre 1938 e 1944 em periódicos do Rio de Janeiro e de São Paulo e reunidas por ele n O empalhador de passarinho. / This dissertation focuses the faithful and annotated edition of The taxidermist finch, twentieth volume of the complete works by Mário de Andrade (1893-1945), published by Editora Martins Bookstore in 1946, after his death. Introducing the collation of work with texts in newspapers and magazines, this edition is enrolled in the Graduate Program in Brazilian Literature at FFLCH-USP, it is a result of the thematic project FAPESP/ IEB/FFLCH-USP Mário de Andrades creative process study: in the manuscripts of his file, his correspondence, in his marginalia in his readings, coordinated between 2006-2011, by professor Telê Ancona Lopez. By analyzing documentation, we sought to understand Mário de Andrades creative process of the critics made by him, from 1938 until 1944 in newspapers and magazines from Rio de Janeiro and São Paulo.
42

Adolescent stress and social experiences : developmental antecedents of adult behavioural responses to unfamiliar stimuli and the underlying neuroendocrine mechanisms

Emmerson, Michael George January 2017 (has links)
During adolescence, animals leave the natal home and interact with potentially threatening stimuli (i.e. stressors), e.g. unfamiliar environments and conspecifics. Adolescent stressors can result in fewer interactions with unfamiliar stimuli in adulthood, plausibly due to sustained effects of glucocorticoid exposure on stress physiology (e.g. glucocorticoid secretion and receptor expression). The current thesis tested the hypothesis that adolescent glucocorticoid exposure and social experiences act as stressors by quantifying the effects of the adolescent experiences on behavioural responses to unfamiliar stimuli and the underlying neuroendocrine mechanisms when in adulthood using two captive species, zebra finches and rats. In study one, adolescent zebra finches were dosed with the glucocorticoid corticosterone. In adulthood, birds dosed with corticosterone in early adolescence took longer to enter an unfamiliar environment when tested individually and had lower expression of the glucocorticoid receptor GR in the hippocampus and hypothalamus, brain regions that regulate stress responses. Glucocorticoids therefore appear to be an endocrine mechanism behind the long-term effects of adolescent stress. Subsequent studies explored whether higher social density and more unfamiliar social interactions during adolescence act as stressors. In study two, early adolescent zebra finches were housed in groups varying in conspecific number and density. In adulthood, females raised in larger groups secreted a higher stressor-induced corticosterone concentration and, if raised at lower density, spent more time in an unfamiliar environment when group housed. In study three, adolescent female rats were housed in familiar pairs or exposed to unfamiliar conspecifics. Unfamiliar adolescent interactions had no effects on responses to unfamiliar environments or stress physiology in adulthood, but heightened ultrasonic call rates. In this thesis, adolescent social experiences do not act like stressors, but modulate (especially female) social behaviour. Adolescent stressors and social experiences therefore have distinct effects on responses to unfamiliar stimuli and stress physiology that are maintained into adulthood.
43

The neuroethology and evolution of nest-building behaviour

Hall, Zachary J. January 2014 (has links)
A surge of recent work elucidating a role for learning and memory in avian nest-building behaviour has challenged the long-standing assumption that nest building develops under genetic control. Whereas that work has been addressed at describing the cognitive mechanisms underpinning nest-building behaviour, almost nothing is known about either the neurobiological processes controlling nest building or the selection pressures responsible for the diversity in avian nest-building behaviour. Here, I sought to identify both the neural substrates involved in nest-building behaviour and some of those selection pressures. First, I used expression of the immediate early gene product Fos, an indirect marker of neuronal activity, to identify brain regions activated during nest-building behaviour in the brains of nest-building and control zebra finches (Taeniogypia guttata). I found that neural circuits involved in motor control, social behaviour, and reward were activated during nest building. Furthermore, I found that subpopulations of neurons that signal using the nonapeptides vasotocin and mesotocin and the neurotransmitter dopamine located within some of these neural circuits were also activated during nest building, suggesting these cell-signalling molecules may be involved in controlling nest-building behaviour. Next, I found that variation in the amount of folding in the cerebellum, a brain structure thought to be involved in manipulative skills, increased with increasing nest structural complexity, suggesting that the cerebellum is also involved in nest building. Finally, using evolutionary statistical models, I found support for the hypothesis that nest-site competition off-ground and increased predation pressure on the ground in Old World babblers (Timaliidae) led to the co-evolution of building domed nests on the ground. Here, then, I provide the first evidence of potential neural substrates controlling and selection pressures contributing to variation in nest-building behaviour.
44

Vliv suplementace karotenoidy a oxidačního stresu na morfologii, kvalitu spermií a spermatogenezi u zebřičky pestré / Interactive effects of carotenoid supplementation and oxidative stress on sperm morphology, sperm quality and spermatogenesis in the Zebra finches

Bílková, Karolína January 2018 (has links)
The phenotype-linked fertility hypothesis predicts that both, male carotenoid-based sexual ornamentation and their spermatozoa are phenotypically plastic and may be co-affected by the environment. One of the factors affecting their phenotype may be oxidative stress and the ability of organism to eliminate its effect. Oxidative stress may reduce sperm quality because sperm lack the ability to repair DNA, but it can also affect spermatogenesis itself. However, some substances may function as antioxidants, and thus eliminate effect of reactive oxygen species (oxidative stress) in the body. In this study, adult zebra finch males (Taeniopygia guttata) originating from the domesticated and recently wild-derived populations were exposed to the diquat (D), which enhances the oxidative stress, and carotenoid lutein (L), which could have an antioxidant function. Experimental design had factorial character 2x2 with a control (group L, D, LD, control). Neither oxidative stress, carotenoids, nor their interactions affected sperm morphology or velocity and it also did not increase abnormal sperm proportion in the ejaculate. However, the differences were observed at the molecular level, where by inducing the oxidative stress, the sperm had reduced signal intensity of acetylated α-tubulin in the sperm tails....
45

Literature and the Enneagram: Applying the Ancient Typing System for New Perspectives on Classic Characters

Bell, Rebekah E. 17 December 2018 (has links)
No description available.
46

Exposure heterogeneity, host immunity and virulence evolution in a wild bird-bacterium system

Leon, Ariel Elizabeth 25 June 2019 (has links)
Immunological heterogeneity is the norm in most free-living vertebrate populations, creating a diverse and challenging landscape for pathogens to replicate and transmit. This dissertation work sought to determine sources of immunological heterogeneity, as well as the consequences of this heterogeneity on pathogen fitness and evolution. A major source of heterogeneity in free-living host populations is the degree of exposure to a pathogen, as well as a host's history of exposure to a pathogen, which can create variation in standing immunity. We sought to determine the role of exposure heterogeneity on host susceptibility and immunity to secondary infection, and the influence of this heterogeneity on pathogen fitness and virulence evolution in a wild bird-bacterium system. We first determined that exposure level has a significant effect on host susceptibility to infection, severity of disease and infection, as well as immunity produced to secondary infection. Subsequently, we tested whether exposure history, and the immunity formed from this previous exposure, altered the within-host fitness advantage to virulent pathogens. We determined that previous low-level repeat exposure, which wild hosts likely encounter while foraging, produces a within-host environment which greatly favors more virulent pathogens. While within-host processes are vital for understanding and interpreting the evolutionary pressures on a pathogen, the ultimate metric of pathogen fitness is transmission. We therefore tested whether exposure history altered the transmission potential of a host and whether prior host exposure selected for more virulent pathogens. The transmission potential of a host significantly decreased with previous exposure, and high levels of previous exposure selected for more virulent pathogens. While we anticipated selection to be strongest at low-levels of exposure based on our previous results, we found here that high doses of prior exposure resulted in the strongest transmission advantage to virulence. This study also provided insight into the nuanced nature of transmission, which our results indicate is determined both by the degree of within-host pathogen replication as well as host disease severity. Together, our findings underscore the importance of exposure level and exposure history in natural populations in determining susceptibility, immunity and pathogen virulence evolution. / Doctor of Philosophy / Infectious diseases disrupt and threaten all life on this planet. To better anticipate and understand why some diseases are more harmful than others, it is vital that we consider the natural variability that exists in animal populations. A major source of variation in populations that experience disease is exposure level to a pathogen, as well as the history of exposure to a pathogen, which can alter an individual’s protection against future exposures. We sought to determine the role of exposure level on the likelihood of an individual contracting an infection, their protection from future infections, and the influence this has on pathogen evolution in a wild bird-bacterium system. We determined that exposure level has a significant effect on the likelihood an individual has of becoming infected, how severe the infection became, as well as how protected they were from future infections. Subsequently, we tested whether exposure history, and the immunity formed from previous exposure, altered the ability of pathogen strains that cause different levels of harm to replicate. We determined that previous low-level exposure, which hosts likely encounter in the wild, creates a level of immunity that favors more harmful strains of the pathogen. While understanding what happens within a host is important, the ultimate metric for predicting whether more or less harmful types of pathogens will persist is the ability of each pathogen type to spread from one host to another. We therefore tested whether exposure history altered the spread potential of a host and whether previous exposure preferentially favored the spread of more harmful pathogens. The spread potential of a host was much lower if that host had previously been exposed to the pathogen, and high levels of previous exposure in hosts only allowed the more harmful pathogen types to spread. We also found that a host’s spread potential was the result of both how much pathogen they had in their body, as well as how inflamed their affected tissues were. Together, our results indicate that natural variation in prior exposure to pathogens, which is common in all animal populations, including humans, can favor more harmful pathogen types.
47

Influence d’une augmentation du taux de testostérone sur les décisions d’approvisionnement chez les diamants mandarins mâles (Taeniopygia guttata)

Le Hô, Mewen 04 1900 (has links)
Un animal qui s’approvisionne en groupe peut rechercher soi-même sa nourriture (tactique producteur) ou tenter de se joindre à des parcelles déjà découvertes par un autre individu (tactique chapardeur). Bien que les modèles de jeu producteur-chapardeur partent du principe que les gains moyens à l’équilibre associés à chacune de ces tactiques sont égaux et ne dépendent pas des caractéristiques des individus, de plus en plus d’études démontrent que le gain de chaque tactique est influencé par certaines caractéristiques phénotypiques (agressivité, capacités d’apprentissage,…). Dans cette étude, nous nous intéressons aux effets de la testostérone sur le choix des tactiques d’approvisionnement chez les mâles de diamant mandarin (Taeniopygia guttata). La testostérone est connue pour influencer le développement du cerveau et l’agressivité, nous avons donc testé les effets d’une exposition prénatale à la testostérone ainsi que durant l’âge adulte sur le choix des tactiques d’approvisionnement lorsque la nourriture est cryptique ou défendable. Nous avons réalisé deux expériences : nous avons tout d’abord utilisé la longueur du tarse ainsi que la différence entre les longueurs des doigts 2 et 4 comme des indicateurs de l’exposition prénatale à la testostérone puis testé si ces différences morphologiques se traduisent par des différences dans le choix des tactiques dans une condition défendable et une condition cryptique. Nous avons trouvé que le choix des tactiques chez les diamants mandarins était limité par le phénotype. Une exposition précoce à la testostérone au cours du développement prénatal pourrait donc être la cause d’au moins une part de la variation observée dans le choix des tactiques d’approvisionnement. Ensuite, nous avons manipulé le taux de testostérone plasmatique chez des mâles adultes grâce à des implants hormonaux sous-cutanés puis comparé le comportement des individus lorsqu’ils portaient un implant hormonal et un implant contrôle et ce, dans chacune des deux conditions d’approvisionnement. Nous n’avons mis en évidence aucun effet du taux de testostérone plasmatique sur le choix des tactiques à l’âge adulte. Nos résultats sont en accord avec l’hypothèse que le choix des tactiques d’approvisionnement peut être influencé par les hormones. Notre conclusion est que les hormones stéroïdiennes peut affecter le choix des tactiques via l’existence d’effets maternels dans le jeu producteur-chapardeur. / An animal foraging in groups can search for its own food (producer tactic) or try to join food patches previously discovered by another group member (scrounger tactic). Although producer-scrounger game models assume that the payoffs associated with both tactic are equal at equilibrium and so do not depend on individual characteristics, there is recent evidence that tactic choice is constrained by certain phenotypical traits (aggressivity, learning abilities…). In this study, we examined the effect of testosterone on tactic use in male zebra finches (Taeniopygia guttata). Because testosterone is known to affect both brain development and aggressiveness, we tested whether differences in testosterone exposure either during development or in adulthood had an effect on producer-scrounger tactic use, when food was cryptic or defendable. First, we measured the tarsus length and the distance between the end of the fourth and the end of the second digit as proxies of prenatal exposure to testosterone, and tested whether they were correlated with foraging tactic use under both conditions. We found that tactic choice in zebra finches is phenotypically constrained. We suggest that early exposure to sex hormones during the embryonic period could be responsible for at least a part of the variation in tactic choice. Second, we manipulated the circulating level of testosterone in adult male zebra finches using subcutaneous testosterone implants, and compared the behavior of individuals when they had either a control implant or a testosterone implant. This time we found no effect of plasmatic level of testosterone on tactic choice. Our results are consistent with the hypothesis that tactic choice in zebra finches could be mediated by hormones. Our finding that steroid hormones can affect tactic use provides evidence for maternal effects in producer-scrounger games.
48

Extraction et analyse du réseau acoustique d'oiseaux sociaux / Extraction and analysis of social birds' acoustic network

Fernandez, Marie 09 April 2018 (has links)
Posséder des données fiables, à jour et précises sur les populations d’oiseaux peut se révéler central aux décisions de politique environnementale. La bioacoustique est un outil de suivi non invasif de populations animales et avantageux lorsque les méthodes d’observation ou les captures sont difficiles. De plus, il a été montré chez de nombreuses espèces que l'étude de la communication acoustique peut largement contribuer à comprendre la dynamique des interactions sociales au sein d'un groupe. Cependant, l'étude des interactions vocales peut se révéler difficile, notamment lorsque l'on souhaite s'intéresser à une échelle fine des échanges. C'est pourquoi la bioacoustique n’a que peu été utilisée pour la caractérisation de la structure sociale de populations. L'objectif de ce projet de thèse était le développement de techniques d’extraction de vocalisations individuelles au sein d'un groupe, ainsi que la modélisation de leur dynamique fine. Après avoir été développée, testée et validée, notre méthode a permis d'étudier le réseau acoustique chez une espèce d'oiseau social, le diamant mandarin, et d'explorer le lien entre réseau acoustique et réseau social. A travers plusieurs études, nous avons montré que la dynamique vocale d'un groupe dépend à la fois de la composition de ce groupe (sa taille, la présence de couples ou de juvéniles) et du contexte environnemental (sans perturbation, puis avec séparation visuelle ou présence d'un danger). Ainsi, avec le développement de méthodes d'extraction de réseau acoustique, ce projet contribue à la fois à la recherche fondamentale et appliquée dans ce domaine : en recherche fondamentale car l'étude de la dynamique des interactions vocales permet de mieux comprendre le réseau social, et en recherche appliquée pour le suivi de population.! / Bird populations represent a significant proportion of urban and rural biodiversity. For this purpose, the acquisition of reliable, updated and precise data on bird population can be a central factor for environmental decisions. The current classical techniques are difficult regarding human resources (banding, tracking, counting) and often invasive. Bioacoustics is a non-invasive tool for animal populations monitoring (density, migration paths...). Moreover, it has been shown in many species that the study of vocal exchanges can largely help to understand the social interactions occurring in a group. However, studying vocal exchanges can be difficult, especially when we want to assess fine scale interactions. For this reason bioacoustics have rarely been used to characterize groups’ social structure. The aim of this project was to develop techniques for the extraction of individual vocalizations in a group, and the modelling of their dynamics at a fine scale. After we developed, tested and validated our method, we used it to extract the acoustic network in a bird social species, the zebra finch, and investigate the link between acoustic and social network. Throughout different studies we showed that the group composition, more particularly its size, the presence of couples or the presence of juveniles can shape parts of the vocal dynamics. We also found that the environmental context (without any perturbation, then a context of separation for a couple, or predation in a group) can impact the vocal interactions dynamics. Thus, this project make contribution to both fundamental and applied research: in fundamental research by contributing to the study of vocal interactions dynamics to better understand the social network, and in applied research by contributing to define new standards for population monitoring.
49

Acoustic communication in female songbirds : functions, flexibility and plasticity in calls / Communication acoustique chez les passereaux femelles : fonctions, flexibilité et plasticité des cris

Villain, Avelyne 12 December 2016 (has links)
La théorie de la sélection sexuelle a drastiquement orienté l’effort de recherche sur la communication acoustique chez les oiseaux : les mâles apprennent et produisent des chants élaborés et les femelles choisissent. Par conséquent (1) la production vocale chez les femelles a été négligée, (2) les cris (la majorité de la communication sociale) ont été peu étudiés. Contrairement aux chants, les cris ont été considérés comme innés et aucun effet de l’environnement sur leur structure n’était attendu. J’ai donc posé la question de la flexibilité vocale (court-terme) et de la plasticité vocale (au cours du développement) chez les femelles, en étudiant les cris majoritairement. J’ai étudié deux contextes où les deux sexes vocalisent: la communication dans le couple au nid et la communication parent-jeunes. Les vocalisations produites au nid par les couples montrent-elles de la flexibilité en réponse au bruit? Le développement des cris est-il influencé par l’environnement social ? J’ai travaillé sur deux espèces: le cincle plongeur, Cinclus cinclus et le diamant mandarin, Taeniopygia guttata. Chez les deux espèces, en réponse au bruit, les couples augmentent l’amplitude de leurs vocalisations. Chez le cincle une variation de la structure spectrale est observée dans les notes de chant mais pas dans les cris. Chez le diamant mandarin, les cris montrent des changements de leur structure spectrale: ils peuvent donc être flexibles en réponse au bruit. Les changements sont similaires chez les femelles et les mâles : la flexibilité n’est pas spécifique du sexe. Enfin, j’ai montré que l’environnement social précoce influence le développement des cris de quémande alimentaire chez le diamant mandarin : il existe une plasticité précoce des cris chez les mâles. J’ai montré que les femelles expriment des degrés de flexibilité similaires aux mâles mais que leur développement vocal peut prendre des trajectoires différentes. Les cris sont de bons objets de recherche pour étudier des variations de comportement vocal liées au sexe / The theory of sexual selection has drastically oriented research on acoustic communication in birds: males learn and sing conspicuous songs and females choose. Consequently, (1) female vocal production has been neglected, (2) birdcalls (most bird social communication) have been understudied. Birdcalls were supposed to be non-learned and no effect of the environment was expected on their structure (no flexibility, no learning). I thus focused my thesis on vocal flexibility (short-term) and vocal plasticity (developmental) of female vocalizations (mainly calls). I studied two contexts in which both sexes produce vocalizations: intrapair communication at the nest and parent-offspring communication. Do pairs express vocal flexibility in their calls in response to environmental noise? Is call development influenced by social environment? I studied two species: the white-throated dippers, Cinclus cinclus. (in which both sexes produce calls and songs) and the zebra finch, Taeniopygia guttata, (in which only males sing but both sexes use the same calls). I showed in both species, that in response to environmental noise, pairs increased the amplitude of their calls or song notes. In dippers, spectral flexibility was observed in song notes but not in calls. However, zebra finch calls showed spectral flexibility in response to noise. Both sexes showed similar changes in their calls: call spectral flexibility is not sex specific. Last, I showed that the structure of male begging calls changed in response to the early social environment, bringing evidence of early vocal plasticity in males. No change was found in females, showing that they either differ in their plasticity abilities or do not express plasticity because they receive different social feedbacks. My work showed that females and males show vocal flexibility but their vocal developmental trajectories may differ. Calls are thus good study objects to investigate sexual dimorphism in vocal behaviour
50

VASODILATORY EFFECTS OF EXOGENOUS NITRIC OXIDE ON THE BROOD PATCH OF THE ZEBRA FINCH (Taeniopygia guttata)

Södergren, Anna January 2010 (has links)
<p>In birds like the Zebra finch (Taeniopygia guttata) the female, but not the male develop a brood patch upon incubation of eggs. The brood patch functions to increase heat exchange between the bird and the eggs. Development of the brood patch includes de-feathering, increased vascularization and edema formation. The increased vascularization is due to the development of arteriovenous anastomoses, AVA. The AVA are thermoregulatory vessels involved in cold induced vasodilation, CIVD, demonstrated to occur in the brood patch. Nitric oxide, NO, which is a well known vasodilator is a candidate substance for involvement in CIVD. In this study a NO-generating gel was applied to the brood patch of male and female zebra finches. Vasodilation was found to be markedly larger in females than in males. The larger vasodilation in the female brood patch is probably because NO vasodilate AVA selectively more than any other vessels. The study also investigated whether vasodilation would cause an increase in brood patch temperature. No definite changes in brood patch temperature could be observed and no conclusions could be drawn in the matter.</p>

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