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Avaliação neuropsicofarmacológica dos mecanismos CRFérgicos na amídala, nas reações de defesa de camundongos pré-expostos à derrota social
(Universidade Federal de São Carlos, 2015-05-15) Cipriano, Ana Cláudia; Souza, Ricardo Luiz Nunes de; https://lattes.cnpq.br/2475842684688693; https://lattes.cnpq.br/5515891277855644
Stressful situations are a real or potential threat for psychological or physiological integrity of an individual. The underlying neurobiological substrates involved in these processes were substancially investigated through the use of animal models of stress. In this context, a crescent number of studies have used more naturalistic animal tests, such as the social defeat test. Regarding neurobiological substrates, it is known that the amygdala plays an important role in the modulation of defensive responses. This forebrain structure has several neurotransmitters and receptors with important implications in emotional states. In this context, the neuropeptide Corticotropin Releasing Factor (CRF) and its receptors, CRF1 and CRF2, have been recently investigated as an important modulatory system of defensive reactions to aversive situations. Activation CRF mechanisms in the amygdala has been postulated as a possible neurochemical substrate underlying the emotional disorders, especially anxiety disorders, induced by stress in humans. To study anxiety-related responses induced by stressors in animals, the elevated plus maze (EPM) test has been widely used. While previous studies have emphasized the role of CRF1 receptors in modulation of anxiety in rodents exposed to the EPM, the involvement of CRF2 receptors remains unclear. Few studies, however, have investigated the effects of CRF and CRF1 and CRF2 antagonists injected directly into the amygdala on the defensive responses in mice. In addition, several studies are needed to clarify the complex relationship between CRF neurotransmission of the amygdala in the etiology of anxiety disorders related to previous exposure to stress. This study investigated the role of CRF in the amygdala upon the defense reactions evaluated in the EPM in mice previously exposed to acute social defeat. Therefore, we carried out experiments to (i) characterize the effects of acute social defeat on behavior in the EPM and on the levels of plasma corticosterone; (ii) to investigate the effects of intraamygdala microinjection of CRF, CRF1 and CRF2 antagonists on the behavior of mice in the EPM and (iii) to investigate the effects of intra-amygdala microinjections of CRF1 and CRF2 antagonists on anxiety-related behaviors of mice pre-exposed to acute social defeat. Results showed that the exposure to acute social defeat stress produces anxiogenesis at short and long terms (i.e, assessed 5 min and 10 days after stress exposure), however short-term anxiety response is variable. Stress-short term effects are accompanied by increased plasma corticosterone levels. In addition, while intra-amygdala CRF increases anxiety, local injection of CRF1 (but not CRF2) receptor antagonists produced anxiolytic-like effects, suggesting a tonic role of CRF1 in the modulation of anxiety in mice exposed to the EPM. However, it was not possible to determine what is the role of CRF neurotransmission in the responses displayed by mice pre-exposed to social defeat and submitted to EPM.
Estudos sobre as equações de Bethe
(Universidade Federal de São Carlos, 2015-05-15) Vieira, Ricardo Soares; Santos, Antonio Lima; https://lattes.cnpq.br/8463237728503334; https://lattes.cnpq.br/8265512739743253
In this dissertation we made an analytic study of the Bethe Ansatz equations for the XXZ six vertex model with periodic boundary conditions. We had show that the Bethe Ansatz equations deduced from the algebraic and coordinate Bethe Ansatze are related by a conformal map. This allowed us to reduce the Bethe Ansatz equations to a system of polynomial equations. For the one, two and three magnon sectors, we succeeded in decouple these equations, so that the solutions could be expressed in terms of the roots of some self-inversive polynomials, Pa (z). Through new theorems deduced here about the distribution of the roots of self-inversive polynomials in the complex plane, we did a thorough analysis of the distribution of the Bethe roots for the two-magnon sector. This analysis allowed us to show that the Bethe Ansatz is indeed complete for this sector, except at some critical values of the anisotropy parameter A, in which the polynomials Pa (z) may have multiple roots. Finally, an unexpected connection between the Bethe Ansatz equations and the Salem polynomials was found and a new algorithm for search small Salem numbers was elaborated.
Contratos formais entre empresas processadoras de laranja e citricultores : um estudo de múltiplos casos entre os anos-safras de 1978/79 a 2011/12 na perspectiva dos citricultores
(Universidade Federal de São Carlos, 2015-05-15) Carvalho, Murilo Secchieri de; Paulillo, Luiz Fernando de Oriani e; https://lattes.cnpq.br/9919942357089937; https://lattes.cnpq.br/1236295876549276
This thesis describes and analyzes from economic transaction cost (ETC) theoretical framework, formal agreements between ten citrus growers and a set of five citrus processors between 1978/79 to 2011/12 harvest seasons. The research uses an exploratory multiple-case study methodology, to deepen the historical relationships established, identifying transactional and relational elements involved, besides the maladaptation problems. The main objective is to verify empirically contractual governance form in São Paulo citrus complex, in the view of new institutional economics (NIE) and the contracts economy, deepening problems of contractual incompleteness, ex-ante and ex-post opportunism and external/internal transaction enforcements requirements. The result of this academic work is a relational contract model proposition that should be implemented in the negotiation between citrus processors and growers, a new orange box buy and sell contracts, supported by relational governance principles and arbitrated by an independent third party. This relational contract model could give greater governance stability and cohesion, reducing conflicts and also transaction cost between citrus growers and processors, modifying São Paulo citrus crises and stagnation that persist more than one decade.
A influência da estereoscopia na experiência imersiva nos videogames
(Universidade Federal de São Carlos, 2015-05-15) Gonçalves, Diogo Augusto; Andrade, Leonardo Antônio de; https://lattes.cnpq.br/3921612856948891; https://lattes.cnpq.br/0555701646963289
Stereoscopy is a form of image reproduction older than photography itself, and unlike it, it rearranges the spatiality of the elements in the screen, allowing observers different points of view. Although stereoscopy being a form of visualization this old, it did not remain obsolete. It has been reinvented nowadays with the help of different reproduction techniques. Stereoscopy expanded to the cinema, and recently for television and videogames. Regarding stereoscopy, this dissertation proposes to address how the tridimensional perspective influences the immersive experience in videogames, leading the virtual space of the game, closer to the interactor, which ultimately creates an intimate relationship between those two agents, giving new meanings to the interaction. Thus, for the development of this research, it was necessary to survey the historical evolution of stereoscopy, videogames and devices that enable immersion through virtual reality, to understand how this evolution happened and which was the motivation that led to this demand. After this historical overview, this research proposes to present what are the features that make the act of playing a video game something so immersive that sensitizes players to try new experiences. At last, we analyze games that use stereoscopy as a feature that enables enhanced immersion in their experiences, in order to understand the strategies that these games use to strengthen the link between the interactor and the fantastic interactive worlds, making a survey of the main characteristics that are aggregated to these games.