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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.
51

It's Not All About The Animals: Veterinarians' Perspectives On Their Work

Owens, Nicole 01 January 2012 (has links)
This study examines lived experiences of veterinarians. A common feature of being a veterinarian is curing and caring for nonhuman animals. It is the love and connection most veterinarians share for animals that ignite their journey to become an animal doctor. Data collected during semi-structured interviews with 17 veterinarians reveal that there are many more intricacies to the job than just animal medicine. These veterinarians suggest that they must treat animals as learning tools during veterinary training and once they complete school, they deal with people and business on a regular basis. Most veterinarians would like their jobs to be animal-centric, but these data show that they are not.
52

Posthumanist Culrural Studies: Taking the Nonhuman Seriously

Cord, Florian 05 March 2024 (has links)
In recent years, there has been a pronounced (re-)turn to questions of ontology, matter, and realism in the humanities and social sciences. What all these theoretical formations have in common is their profound challenge to human exceptionalism. Taken together, these approaches have productively been described as constituting a “nonhuman turn.” This article is a theoretical exploration of the relationship between the intellectual and political practice of Cultural Studies on the one hand and the nonhuman turn on the other. For this purpose, it brings both “into encounter” (Donna Haraway), investigating points of affinity, tension, and compatibility. The essay argues that such a theoretical encounter could prove to be tremendously fruitful, both intellectually and politically, and that Cultural Studies should thus take a genuine interest in these new approaches, engage with them, put them to the test, and, when needed, “translate” and “re-articulate” them. The result could be a Cultural Studies for the Anthropocene which would have a lot to contribute to the critical (cultural/political/social/economic) struggles being fought today.
53

The Habitat : A Posthumanist Design Project for Making Kin with Nonhuman

Hafazoglu, Betyul January 2022 (has links)
‘the habitat’ is a Design+Change project which originates from the will to create positive change in the current situation of climate and ecological emergency. The design project takes the Anthropocene and the materialization of nonhumans as starting point and develops further around the possibilities of forming non-anthropocentric and nonhuman-centered mentalities and world-making processes. It aims to highly emphasize the human dependence on nonhuman existence and well-being. Therefore, the ultimate purpose of the project is to de-center humans and challenge the human exceptionalist mentality. In order to achieve that; practices of making kin with nonhumans are explored and practiced throughout the project. This Design+Change project builds its framework within the theories of posthumanism by Braidotti (2013) (2017) and Barad (2008), the vitality of matter by Bennett (2010) and gets inspiration from multispecies ethnography and design, discusses the possibilities of making kin (Haraway, 2016) with nonhumans. Building on the theoretical framework, my own lived experiences of sharing my domestic environment and my attempts to interact, and interconnect with fungi persons, strive to show interdependencies of life, the assemblages weaved in intertangled lives of humans and nonhumans and to overcome human exceptionalist mindsets and lifestyles. ‘the habitat’ seeks to also question the dichotomies of nature/culture, animate/inanimate. The discussion of the nonhuman agency has also been essential throughout the design project.  ‘the habitat’ displays a journey, an intimate autoethnographic mental expedition, rather than being a monolithic and finished product. It presents my bare attempts and generates discussions from them. At the end of the project, it wraps itself up in the form of an archive, a map, and a record of the journey for the audience to walk through.
54

Escolha e transporte de ferramentas para a quebra de cocos por macacos-prego (Sapajus sp) em semi-liberdade: manipulação experimental dos custos da distância dos \"martelos\" às \"bigornas\" e da eficiência da ferramenta / Selection and transport of tools to crack open nuts by semifree-ranging capuchin monkeys (Sapajus sp): experimental manipulation of the costs of the distance between \"hammers\" and \"anvils\" and efficiency of the tool

Fonseca, Bianca de Oliveira 27 March 2012 (has links)
Experimentos realizados com grupos de macacos-prego (Sapajus sp) cativos, semilivres e livres em tarefas de escolha de ferramentas para a quebra de frutos encapsulados parecem indicar que esses primatas possuem a capacidade de distinguir ferramentas funcionais de não-funcionais e que também sejam capazes de escolher, dentre as funcionais, a ferramenta mais eficiente. Neste estudo buscamos examinar estas escolhas num grupo semi-livre de macacos-prego através de experimentos que tiveram como objetivos gerais analisar possíveis preferências por martelos de determinados pesos e os efeitos de custos e benefícios associados ao seu transporte e manejo, verificando se essas preferências se modificam em função da distância de transporte até o local de uso (as bigornas) ou do grau de dureza dos cocos oferecidos. Encontramos uma preferência dos juvenis por martelos mais pesados que os escolhidos pelos adultos, o que pode refletir uma compensação daqueles, menores e mais fracos, já que com um martelo mais pesado, menos golpes são necessários para romper o coco. As escolhas individuais parecem vii indicar a influência de fatores, como tamanho corporal e experiência na quebra de cocos, na escolha dos martelos em função do peso. Depois do peso, o custo do transporte da ferramenta até o local de uso parece ter sido a variável de maior importância, dentre as que investigamos, na escolha do peso médio dos martelos: quando estes tinham que ser transportados até as bigornas, os indivíduos escolheram martelos mais leves em comparação com a situação onde os martelos eram oferecidos junto às bigornas; entretanto esse custo não parece ser levado em conta de forma precisa, uma vez que a distância de transporte (5m x 10m) não afetou as escolhas. As escolhas por martelos de determinada faixa de peso também não variaram significativamente em função das espécies de cocos oferecidas, jerivá, Syagrus Romanzoffiana (menor) e indaiá, Atallea dubia (maior) / Experiments with captive, semi-free and wild tufted capuchin (Sapajus sp) groups in tasks involving the selection of tools to crack encapsulated fruit seem to show that these primates can distinguish functional from non-functional tools, and also choose, among functional tools, the most efficient ones. In the present study, we investigate these choices in a semi-free group by means of experiments analyzing the potential preferences for hammer stones of a particular weight and the effects of costs and benefits associated with their transport and handling, to verify whether these preferences are modified as a function of the transport distance to their place of utilization (the anvils) or of the toughness of the available nuts. We found a preference by juveniles for heavier hammers than the ones chosen by adults, which may point to a compensation by the former, since they are smaller and weaker, and heavier hammers require less strikes to crack nuts open. Individual choices seem to indicate the influence of factor such as body size and nut cracking experience on hammer choice. ix Besides weight, the costs of transporting the tools to their utilization sites seem to be the most relevant variable examined affecting the average weight of the chosen hammers: when these had to be carried to the anvils, the subjects selected lighter hammers, as compared to when hammers were made available near the anvils. The precise transport costs did not seem to be taken into account, though, since the transport distance (5m x 10m) did not affect choices. The choice of hammers of a given weight were also not significantly affected by the palm nut species made available, either Syagrus Romanzoffiana (smaller), or Atallea dubia (bigger)
55

\"Estudo dos Processos de Aprendizagem Individual e Social em Macacos-Prego (Cebus Apella) a partir de Manipulação de uma Caixa-Problema\". / Study of individual and social learning processes in Tufted capuchin monkeys (Cebus apella) through the manipulation of a problem-box

Resende, Briseida Dogo de 03 November 1999 (has links)
Macacos-prego (Cebus apella) são proficientes manipuladores de objetos. Este trabalho teve como objetivo estudar os processos de aprendizagem individual e social que durante a aquisição de um comportamento que consistia na abertura de trincos de uma caixa-problema. Foram utilizados dois grupos de macacos, sendo que de cada grupo um indivíduo foi treinado para executar a tarefa. A análise do processo de aprendizagem individual destes dois sujeitos foi feita a partir da construção de curvas de aprendizagem que levaram em conta a interação dos animais com a caixa e com os trincos. Além disso, foi feita uma análise de seqüências comportamentais através do uso de modelos log-lineares. Posteriormente, estes sujeitos serviram de modelo para os outros indivíduos do seu grupo: o sujeito treinado executava a tarefa enquanto era assistido por um outro indivíduo do grupo. Em seguida o modelo era retirado do recinto e o observador poderia tentar executar a tarefa. Desta forma pretendia-se estudar os processos de aprendizagem por observação. Os macacos-prego devidamente treinados tornaram-se eficientes abridores de trincos, evidenciando que possuem uma grande capacidade de aprendizagem individual. Os dados sobre aprendizagem social foram inconclusivos principalmente porque os observadores não observaram adequadamente a demonstração da tarefa. / Capuchin monkeys (Cebus apella) are excellent object handlers. This work aimed to study individual and social learning processes which took place during the aquisition of a task that consisted on opening bolts from a problem-box. Two groups were used and, from each group, one subject was trained to perform the task. The analysis of the individual learning process was based on the construction of learning curves with the animals\' interactions with the box and the bolts. Besides, an analysis of behavior sequences through the use of log-linears models was performed. Then, these subjects were used as models for the other subjects in their own group: the trained subject performed the task while another subject of the group watched. Afterwards, the model was put aside and the observer would be allowed to try to solve the task in order to study observational learning processes. The well trained monkeys became efficient bolt openers, showing that they have great individual learning skills. Data from social learning were inconclusive mainly because the observers didn\'t watch the demonstration of the task properly.
56

Uso de ferramentas por macacos-prego (Sapajus libidinosus) do parque nacional Serra da capivara - PI / Tool use by capuchin monkeys (Sapajus libidinosus) of Serra da Capivara National Park

Falotico, Tiago 17 August 2011 (has links)
O uso de ferramentas, sabe--se atualmente, é típico das populações selvagens de macacos--prego (Sapajus sp) nos biomas da Caatinga e Cerrado. No Parque Nacional Serra da Capivara -- PI (PNSC), estudos anteriores mostraram que o \"kit de ferramentas\" dos S. libidinosus da área era bem mais diverso que em outras populações. Uma das possíveis explicações para essas diferenças seria a de variações tradicionais entre essas populações. O objetivo desse trabalho foi (1) descrever as ferramentas usadas por dois grupos de macacos--prego do PNSC, suas características físicas, suas frequências de uso e demografia dentro dos grupos, além das correlações com fatores físicos do ambiente; (2) buscar evidências de aprendizagem socialmente mediada para esses comportamentos, e (3) determinar as possíveis tradições comportamentais no uso de ferramentas por estes grupos. As ferramentas usadas pelos grupos Pedra Furada (PF) e Bocão (BC) foram de dois tipos de materiais, pedras e varetas. As pedras eram usadas como: martelo para quebrar frutos encapsulados e sementes, martelo para soltar solo e cavar, enxada para cavar, martelo para pulverizar seixos, e pedra para arremesso durante display sexual de fêmeas. As varetas eram usadas como sondas para expulsar invertebrados e pequenos vertebrados de seus esconderijos e também para extrair mel de dentro de ocos de troncos. O outro uso das varetas foi como lanças em episódios de ameaças a outros animais. Os dois grupos apresentaram o uso de todas essas ferramentas (com exceção das pedras de arremesso, só registradas no grupo PF), mas suas frequências de ocorrência foram diferentes em alguns casos. O uso de varetas foi o único tipo de ferramenta a se mostrar um comportamento quase exclusivo dos machos. Esses resultados ratificam os estudos anteriores e confirmam a diversidade das ferramentas usadas por essas população do PNSC. Além disso, descrevem um comportamento inédito em macacos--prego selvagens, as pedras de arremesso, que são bastante interessantes por serem ferramentas usadas em contexto comunicativo. A frequência geral de uso das ferramentas foi correlacionada positivamente com o período seco, no entanto, no caso das ferramentas de pedra para quebra, houve uma correlação positiva com a disponibilidade de alimento de origem vegetal, mostrando que essas ferramentas eram mais usadas quando havia mais disponibilidade de alimentos. As evidências da aprendizagem socialmente mediada sugerem que a aprendizagem do uso das ferramentas tem um viés social que ocorre por realce de estímulo. Foram identificadas seis possíveis tradições de uso de ferramentas nos grupos. Pelo método comparativo, nossas observações foram comparadas com dados relativos a outras populações que não apresentam os mesmos comportamentos, e as explicações ecológicas e genéticas aparentemente não explicam as diferenças, apesar de não poderem ser completamente descartadas. Já o método do espaço tradicional indica que alguns comportamentos são tradições, mas não pode afirmar com certeza, pois a aprendizagem social dos mesmos não pode ser categoricamente corroborada pela metodologia usada. Apesar dessas limitações, as evidências sugerem que os comportamentos de uso de ferramentas estudados provavelmente são tradições dos grupos do PNSC / Tool use by capuchin monkeys (Sapajus sp) is currently known in many wild populations in Caatinga and Cerrado biomes. Previous studies in Serra da Capivara National Park Piauí State (SCNP), showed that the \"tool kit\" of S. libidinosus in that area was much more diverse than in other populations. One possible explanation for these differences is the occurrence of traditional variations between these populations. The aim of this study was (1) to describe the tools used by two groups of capuchin monkeys in SCNP, their physical characteristics, frequencies of use and demographics within the groups, and to find correlations with physical factors of the environment, (2) search for evidence of socially mediated learning in these behaviors, and (3) determine the possible behavioral traditions of these groups. The tools used by groups Pedra Furada (PF) and Bocão (BC) were made from two materials, stones and sticks. The stones were used as \"hammer\" to break encapsulated fruits and seeds, \"hammer\" to loosen soil and dig, \"hoe\" to dig, \"hammer\" to pulverize pebbles and stone throwing during female sexual display. The sticks were used as probes to expel invertebrates and small vertebrates from their hiding places and also to extract honey from inside trunks hollows. The other use of sticks was as spears in threaten episodes to other animals. The two groups used all of these tools (except for the throwing stones, only recorded in the PF group), but their frequencies were different in some cases. The use of sticks was the only type of tool to be used almost exclusive by males. These results support previous studies and confirm the diversity of tools used by this population of SCNP. In addition, it was described a novel behavior in wild capuchin monkeys, the throwing stones, which is quite interesting because they are used in a communicative context. The total frequency of tool use was positively correlated with the dry period, however, for the cracking stone tools, there was a positive correlation with vegetal food availability, showing that these tools were more used when there was more food available. The evidence for socially mediated learning suggests that tool use learning has a social bias that occurs by stimulus enhancement. Six possible tool use traditions were identified in these groups. Using the comparative method the data was compared to other populations that do not exhibit the behavior, and ecological and genetic explanations do not seem to explain the differences (although they cannot be completely discarded). The traditional space method indicates that some behaviors are traditions, but cannot firmly confirm, because social learning cannot be corroborated with the used methodology. Despite these limitations, the analysis suggests that the studied tool--using behaviors are likely to be traditions of the PNSC groups
57

Escolha e transporte de ferramentas para a quebra de cocos por macacos-prego (Sapajus sp) em semi-liberdade: manipulação experimental dos custos da distância dos \"martelos\" às \"bigornas\" e da eficiência da ferramenta / Selection and transport of tools to crack open nuts by semifree-ranging capuchin monkeys (Sapajus sp): experimental manipulation of the costs of the distance between \"hammers\" and \"anvils\" and efficiency of the tool

Bianca de Oliveira Fonseca 27 March 2012 (has links)
Experimentos realizados com grupos de macacos-prego (Sapajus sp) cativos, semilivres e livres em tarefas de escolha de ferramentas para a quebra de frutos encapsulados parecem indicar que esses primatas possuem a capacidade de distinguir ferramentas funcionais de não-funcionais e que também sejam capazes de escolher, dentre as funcionais, a ferramenta mais eficiente. Neste estudo buscamos examinar estas escolhas num grupo semi-livre de macacos-prego através de experimentos que tiveram como objetivos gerais analisar possíveis preferências por martelos de determinados pesos e os efeitos de custos e benefícios associados ao seu transporte e manejo, verificando se essas preferências se modificam em função da distância de transporte até o local de uso (as bigornas) ou do grau de dureza dos cocos oferecidos. Encontramos uma preferência dos juvenis por martelos mais pesados que os escolhidos pelos adultos, o que pode refletir uma compensação daqueles, menores e mais fracos, já que com um martelo mais pesado, menos golpes são necessários para romper o coco. As escolhas individuais parecem vii indicar a influência de fatores, como tamanho corporal e experiência na quebra de cocos, na escolha dos martelos em função do peso. Depois do peso, o custo do transporte da ferramenta até o local de uso parece ter sido a variável de maior importância, dentre as que investigamos, na escolha do peso médio dos martelos: quando estes tinham que ser transportados até as bigornas, os indivíduos escolheram martelos mais leves em comparação com a situação onde os martelos eram oferecidos junto às bigornas; entretanto esse custo não parece ser levado em conta de forma precisa, uma vez que a distância de transporte (5m x 10m) não afetou as escolhas. As escolhas por martelos de determinada faixa de peso também não variaram significativamente em função das espécies de cocos oferecidas, jerivá, Syagrus Romanzoffiana (menor) e indaiá, Atallea dubia (maior) / Experiments with captive, semi-free and wild tufted capuchin (Sapajus sp) groups in tasks involving the selection of tools to crack encapsulated fruit seem to show that these primates can distinguish functional from non-functional tools, and also choose, among functional tools, the most efficient ones. In the present study, we investigate these choices in a semi-free group by means of experiments analyzing the potential preferences for hammer stones of a particular weight and the effects of costs and benefits associated with their transport and handling, to verify whether these preferences are modified as a function of the transport distance to their place of utilization (the anvils) or of the toughness of the available nuts. We found a preference by juveniles for heavier hammers than the ones chosen by adults, which may point to a compensation by the former, since they are smaller and weaker, and heavier hammers require less strikes to crack nuts open. Individual choices seem to indicate the influence of factor such as body size and nut cracking experience on hammer choice. ix Besides weight, the costs of transporting the tools to their utilization sites seem to be the most relevant variable examined affecting the average weight of the chosen hammers: when these had to be carried to the anvils, the subjects selected lighter hammers, as compared to when hammers were made available near the anvils. The precise transport costs did not seem to be taken into account, though, since the transport distance (5m x 10m) did not affect choices. The choice of hammers of a given weight were also not significantly affected by the palm nut species made available, either Syagrus Romanzoffiana (smaller), or Atallea dubia (bigger)
58

Uso de ferramentas por macacos-prego (Sapajus libidinosus) do parque nacional Serra da capivara - PI / Tool use by capuchin monkeys (Sapajus libidinosus) of Serra da Capivara National Park

Tiago Falotico 17 August 2011 (has links)
O uso de ferramentas, sabe--se atualmente, é típico das populações selvagens de macacos--prego (Sapajus sp) nos biomas da Caatinga e Cerrado. No Parque Nacional Serra da Capivara -- PI (PNSC), estudos anteriores mostraram que o \"kit de ferramentas\" dos S. libidinosus da área era bem mais diverso que em outras populações. Uma das possíveis explicações para essas diferenças seria a de variações tradicionais entre essas populações. O objetivo desse trabalho foi (1) descrever as ferramentas usadas por dois grupos de macacos--prego do PNSC, suas características físicas, suas frequências de uso e demografia dentro dos grupos, além das correlações com fatores físicos do ambiente; (2) buscar evidências de aprendizagem socialmente mediada para esses comportamentos, e (3) determinar as possíveis tradições comportamentais no uso de ferramentas por estes grupos. As ferramentas usadas pelos grupos Pedra Furada (PF) e Bocão (BC) foram de dois tipos de materiais, pedras e varetas. As pedras eram usadas como: martelo para quebrar frutos encapsulados e sementes, martelo para soltar solo e cavar, enxada para cavar, martelo para pulverizar seixos, e pedra para arremesso durante display sexual de fêmeas. As varetas eram usadas como sondas para expulsar invertebrados e pequenos vertebrados de seus esconderijos e também para extrair mel de dentro de ocos de troncos. O outro uso das varetas foi como lanças em episódios de ameaças a outros animais. Os dois grupos apresentaram o uso de todas essas ferramentas (com exceção das pedras de arremesso, só registradas no grupo PF), mas suas frequências de ocorrência foram diferentes em alguns casos. O uso de varetas foi o único tipo de ferramenta a se mostrar um comportamento quase exclusivo dos machos. Esses resultados ratificam os estudos anteriores e confirmam a diversidade das ferramentas usadas por essas população do PNSC. Além disso, descrevem um comportamento inédito em macacos--prego selvagens, as pedras de arremesso, que são bastante interessantes por serem ferramentas usadas em contexto comunicativo. A frequência geral de uso das ferramentas foi correlacionada positivamente com o período seco, no entanto, no caso das ferramentas de pedra para quebra, houve uma correlação positiva com a disponibilidade de alimento de origem vegetal, mostrando que essas ferramentas eram mais usadas quando havia mais disponibilidade de alimentos. As evidências da aprendizagem socialmente mediada sugerem que a aprendizagem do uso das ferramentas tem um viés social que ocorre por realce de estímulo. Foram identificadas seis possíveis tradições de uso de ferramentas nos grupos. Pelo método comparativo, nossas observações foram comparadas com dados relativos a outras populações que não apresentam os mesmos comportamentos, e as explicações ecológicas e genéticas aparentemente não explicam as diferenças, apesar de não poderem ser completamente descartadas. Já o método do espaço tradicional indica que alguns comportamentos são tradições, mas não pode afirmar com certeza, pois a aprendizagem social dos mesmos não pode ser categoricamente corroborada pela metodologia usada. Apesar dessas limitações, as evidências sugerem que os comportamentos de uso de ferramentas estudados provavelmente são tradições dos grupos do PNSC / Tool use by capuchin monkeys (Sapajus sp) is currently known in many wild populations in Caatinga and Cerrado biomes. Previous studies in Serra da Capivara National Park Piauí State (SCNP), showed that the \"tool kit\" of S. libidinosus in that area was much more diverse than in other populations. One possible explanation for these differences is the occurrence of traditional variations between these populations. The aim of this study was (1) to describe the tools used by two groups of capuchin monkeys in SCNP, their physical characteristics, frequencies of use and demographics within the groups, and to find correlations with physical factors of the environment, (2) search for evidence of socially mediated learning in these behaviors, and (3) determine the possible behavioral traditions of these groups. The tools used by groups Pedra Furada (PF) and Bocão (BC) were made from two materials, stones and sticks. The stones were used as \"hammer\" to break encapsulated fruits and seeds, \"hammer\" to loosen soil and dig, \"hoe\" to dig, \"hammer\" to pulverize pebbles and stone throwing during female sexual display. The sticks were used as probes to expel invertebrates and small vertebrates from their hiding places and also to extract honey from inside trunks hollows. The other use of sticks was as spears in threaten episodes to other animals. The two groups used all of these tools (except for the throwing stones, only recorded in the PF group), but their frequencies were different in some cases. The use of sticks was the only type of tool to be used almost exclusive by males. These results support previous studies and confirm the diversity of tools used by this population of SCNP. In addition, it was described a novel behavior in wild capuchin monkeys, the throwing stones, which is quite interesting because they are used in a communicative context. The total frequency of tool use was positively correlated with the dry period, however, for the cracking stone tools, there was a positive correlation with vegetal food availability, showing that these tools were more used when there was more food available. The evidence for socially mediated learning suggests that tool use learning has a social bias that occurs by stimulus enhancement. Six possible tool use traditions were identified in these groups. Using the comparative method the data was compared to other populations that do not exhibit the behavior, and ecological and genetic explanations do not seem to explain the differences (although they cannot be completely discarded). The traditional space method indicates that some behaviors are traditions, but cannot firmly confirm, because social learning cannot be corroborated with the used methodology. Despite these limitations, the analysis suggests that the studied tool--using behaviors are likely to be traditions of the PNSC groups
59

\"Estudo dos Processos de Aprendizagem Individual e Social em Macacos-Prego (Cebus Apella) a partir de Manipulação de uma Caixa-Problema\". / Study of individual and social learning processes in Tufted capuchin monkeys (Cebus apella) through the manipulation of a problem-box

Briseida Dogo de Resende 03 November 1999 (has links)
Macacos-prego (Cebus apella) são proficientes manipuladores de objetos. Este trabalho teve como objetivo estudar os processos de aprendizagem individual e social que durante a aquisição de um comportamento que consistia na abertura de trincos de uma caixa-problema. Foram utilizados dois grupos de macacos, sendo que de cada grupo um indivíduo foi treinado para executar a tarefa. A análise do processo de aprendizagem individual destes dois sujeitos foi feita a partir da construção de curvas de aprendizagem que levaram em conta a interação dos animais com a caixa e com os trincos. Além disso, foi feita uma análise de seqüências comportamentais através do uso de modelos log-lineares. Posteriormente, estes sujeitos serviram de modelo para os outros indivíduos do seu grupo: o sujeito treinado executava a tarefa enquanto era assistido por um outro indivíduo do grupo. Em seguida o modelo era retirado do recinto e o observador poderia tentar executar a tarefa. Desta forma pretendia-se estudar os processos de aprendizagem por observação. Os macacos-prego devidamente treinados tornaram-se eficientes abridores de trincos, evidenciando que possuem uma grande capacidade de aprendizagem individual. Os dados sobre aprendizagem social foram inconclusivos principalmente porque os observadores não observaram adequadamente a demonstração da tarefa. / Capuchin monkeys (Cebus apella) are excellent object handlers. This work aimed to study individual and social learning processes which took place during the aquisition of a task that consisted on opening bolts from a problem-box. Two groups were used and, from each group, one subject was trained to perform the task. The analysis of the individual learning process was based on the construction of learning curves with the animals\' interactions with the box and the bolts. Besides, an analysis of behavior sequences through the use of log-linears models was performed. Then, these subjects were used as models for the other subjects in their own group: the trained subject performed the task while another subject of the group watched. Afterwards, the model was put aside and the observer would be allowed to try to solve the task in order to study observational learning processes. The well trained monkeys became efficient bolt openers, showing that they have great individual learning skills. Data from social learning were inconclusive mainly because the observers didn\'t watch the demonstration of the task properly.
60

Studies of Innate and Adaptive Immunity in Islet Transplantation

Hårdstedt, Maria January 2014 (has links)
Clinical islet transplantation is today an established alternative treatment for a selected group of type 1 diabetes patients. The predominant technique for transplantation is infusion of islets in the liver via the portal vein. Obstacles to advancing islet transplantation include limited engraftment resulting from an immediate blood-mediated inflammatory reaction (IBMIR), a life-long need for immunosuppression and the shortage of organs available. In this thesis, innate and adaptive immunity were explored in allogeneic and xenogeneic settings, with the long-term goal of preventing islet graft destruction. Methods for studying immune responses to islets in blood and engrafted islets in liver tissue (intragraft gene expression) were developed and refined. The innate response to human islets and exocrine tissue in ABO-compatible blood was characterized up to 48 h using a novel whole-blood model. Physiological changes in the blood during incubations were explored and adjusted to allow prolonged experiments. Increased production of chemokines targeting CXCR1/2, CCR2 and CXCR3 was observed, accompanied by massive intra-islet neutrophil infiltration. Notably, endocrine and exocrine tissue triggered a similarly strong innate immune response. Two studies of adult porcine islet transplantation to non-human primates (NHPs) were performed. Expression of immune response genes induced in liver tissue of non-immunosuppressed NHPs (≤72 h) was evaluated after porcine islet transplantation. Up-regulation of CXCR3 mRNA, together with IP-10, Mig, MIP-1α, RANTES, MCP-1 and cytotoxic effector molecule transcripts, was associated with T-cell and macrophage infiltration at 48-72 h. Long-term survival (>100 days) of adult porcine islets in a NHP model was later demonstrated using T-cell-based immunosuppression, including co-stimulatory blockade (anti-CD154 mAb). Graft failure was associated with increased levels of circulating, indirectly activated T cells, non-Gal pig-specific IgG and gene transcripts of inflammatory cytokines. Microarray analysis of the response to inflammatory cytokines in cultured porcine islets identified genes involved in cell death, immune responses and oxidative stress; this gene pattern coincided with physiological changes (decrease in insulin and ATP content). In summary, allogeneic whole-blood experiments and xenogeneic in vivo studies underscored the importance of preventing early inflammation and cell-recruitment to avoid islet graft loss in islet transplantation. Long-term survival of porcine islets in NHPs was shown to be feasible using T-cell-directed immunosuppression, including anti-CD154 mAb.

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