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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.
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Efeitos comportamentais, neuroquÃmicos e antioxidante da hecogenina obtida de Agave sisalana Perrine em Camundongos / Behavioral, neurochemical and antioxidant effects of Hecogenin Obtained of Agave sisalana Perrine in mice

Rita Neuma Dantas Cavalcante de Abreu 09 July 2013 (has links)
Agave sisalana, popularmente conhecida como sisal, à uma planta originada do MÃxico, fazendo parte da famÃlia Agavaceae. No suco das folhas de Agave à encontrado hecogenina (HEC), uma sapogenina esteroidal. O objetivo foi estudar os efeitos comportamentais, neuroquÃmicos e antioxidante de HEC em camundongos. Foram utilizados camundongos Swiss, machos, pesando de 25-35 g. Os efeitos comportamentais da administraÃÃo aguda da HEC (5, 10, 20 ou 40 mg/kg, via intraperitoneal - ip) ou em doses repetidas por sete dias (20 ou 40 mg/kg, ip) foram avaliados pelos testes: labirinto em cruz elevado, campo aberto, placa perfurada e suspensÃo de cauda. Nestes testes, determinou-se o mecanismo de aÃÃo da HEC com administraÃÃo aguda de Flumazenil 2,5 mg/kg (FLU) ou Reserpina 2 mg/kg (RES). ApÃs os testes comportamentais, as Ãreas cerebrais cÃrtex PrÃ-frontal (CPF), hipocampo (HC) e corpo estriado (CE) foram dissecadas. O teste de labirinto em cruz elevado mostrou que a HEC, administrada agudamente, nas doses de 10, 20 ou 40 mg/kg, causou aumento significativo no nÃmero de entradas nos braÃos abertos (NEBA) comparado ao controle. Efeito semelhante foi observado no tempo de permanÃncia nos braÃos abertos (TPBA) nas doses de 20 ou 40 mg/kg em relaÃÃo ao grupo controle. A administraÃÃo em doses repetidas da HEC (20 ou 40 mg/kg) tambÃm aumentou o NEBA. HEC (20 ou 40 mg/kg), administrada agudamente, aumentou o nÃmero de head dips comparado ao controle. Efeito semelhante foi observado apÃs o tratamento em doses repetidas com a HEC na dose de 40 mg/kg em relaÃÃo ao grupo controle. O FLU nÃo foi capaz de reverter os efeitos ansiolÃticos agudos da HEC no labirinto em cruz elevado e no teste de placa perfurada. Hecogenina reduziu o tempo de imobilidade no teste de suspensÃo de cauda apÃs o tratamento agudo ou em doses repetidas. A molÃcula em estudo (HEC) reverteu o efeito depressor da RES. Referente aos efeitos da administraÃÃo aguda da HEC sobre a peroxidaÃÃo lipÃdica, observou-se uma diminuiÃÃo nas trÃs areas estudadas nas doses 5, 10, 20 ou 40 mg/kg, comparado com os grupos controles. Nas doses de 20 ou 40 mg/kg, HEC causou diminuiÃÃo dos nÃveis de nitrito no CPF, HC e CE comparado ao controle. No CPF, de camundongos tratados agudamente com HEC, o aminoÃcido excitatÃrio glutamato (GLU) aumentou nas doses de 10, 20 ou 40mg/kg. Enquanto os inibitÃrios Ãcido gamaaminobutÃrico (GABA) e Taurina (TAU) aumentaram nas doses de 20 ou 40mg/kg. No hipocampo, houve aumento de Aspartato (ASP), GLU, Glicina (GLI) e TAU apenas na maior dose de HEC. No corpo estriado, ocorreu o aumento do ASP, GLU e TAU apÃs as doses de 20 ou 40 mg/kg de HEC. As concentraÃÃes de GLI e GABA aumentaram na maior dose de HEC (40 mg/kg) nesta Ãrea cerebral. Os nÃveis de 5-HT e 5-HIAA foram aumentados apenas na dose de 40 mg/kg de HEC. Concluiu-se que HEC (20 ou 11 40 mg/kg) apresentou efeitos ansiolÃticos e este efeito nÃo foi relacionado aos receptores benzodiazepÃnicos. A molÃcula nÃo causou estresse oxidativo ao SNC. / Agave sisalana, popularly known as sisal, is a plant originaly from Mexico and belongs to the family Agavaceae. Hecogenin (HEC) is a steroidal sapogenin found in the juice from the leaves of Agave. The purpose was to study the behavioral, neurochemical and antioxidant effects of HEC in mice. We used swiss mice weighing 25-35 g. The behavioral effects of HEC‟s acute administration (5, 10, 20, or 40 mg/kg intraperitoneally â i.p.) or in repeated doses for seven days (20 or 40 mg/kg, i.p.), were evaluated by tests: elevated plus maze, open field, hole board test and tail suspension. In these tests, we determined the mechanism of action of HEC with acute administration of Flumazenil 2.5 mg/kg (FLU) or Reserpine 2 mg/kg (RES). After the behavioral tests, the brain areas pre-frontal cortex (PFC), hippocampus (HC) and striatum (CE) were dissected. The elevated plus-maze test showed that HEC, acutely administered, at doses of 10, 20 or 40 mg/kg, caused a significant increase in the number of entries in the open arms (NEOA) compared to control. A similar effect was observed in the time spent in the open arms (TPOA) at doses of 20 or 40 mg/ kg compared to the control group. The administering repeated doses of HEC (20 or 40 mg/kg) increased the NEOA. HEC (20 or 40 mg/kg) administered acutely increased the number of head dips compared to control. A similar effect was observed after treatment with repeated doses of HEC at a dose of 40 mg/kg compared to the control group. The FLU was unable to reverse the acute anxiolytic effects of HEC in the elevated plus-maze test and in the hole board test. Hecogenin reduced the immobility time in the tail suspension test after acute treatment or repeated doses. The molecule under study (HEC) reversed the depressant effect of RES. Related to the effects of acute administration of HEC on lipid peroxidation, we observed a decrease in the three studied areas at 5, 10, 20 or 40 mg/kg doses, compared to control groups. At doses of 20 or 40 mg/kg, HEC caused decreased levels of nitrite in the PFC, HC and CE compared to control. In PFC‟s mice acutely treated with HEC, the excitatory amino acid glutamate (GLU) increased at doses of 10, 20 or 40mg/kg, while the inhibitory gamaaminobutiric acid (GABA) and taurine (TAU) increased at doses of 20 or 40mg/kg. In the mice‟s hippocampus treated with HEC, there was increased aspartate (ASP), GLU, glycine (GLY) and TAU only at the highest dose HEC. In the striatum, there was an increase of ASP, and GLU and TAU after doses of 20 or 40 mg/kg of HEC. Concentrations of GLY and GABA increased HEC at the highest dose (40 mg/kg) in this brain area. The 5-HT and 5-HIAA levels were increased only in 40 mg/kg dose of HEC. We concluded that HEC (20 or 40 mg/kg) showed anxiolytic effects and this effect was not related to benzodiazepine receptors. The molecule did not cause oxidative stress to the CNS.
2

Toxicidade e repelência do óleo essencial de negramina para lagarta do cartucho e lagarta da soja

Lourenço, Adriano Mendes 03 February 2016 (has links)
O uso recorrente de produtos químicos para o controle de Spodoptera frugiperda e Anticarsia gemmatalis tem levado a indução de populações resistentes, tornando-se necessário o uso de óleos essenciais como uma alternativa de controle. Dessa forma, o presente trabalho teve por objetivo avaliar a atividade inseticida e repelente do óleo essencial de Siparuna guianensis contra S. frugiperda e A. gemmatalis, bem como verificar os padrões comportamentais de caminhamento dessas pragas quando submetidas ao óleo essencial. De acordo com resultados obtidos, observou-se alta toxicidade do óleo essencial de S. guianensis para todos os estádios de S. frugiperda e A. gemmatalis, bem como percentuais de repelência de até 100% (18μL /900μL) para ambas as espécies. No teste de fagoinibição alimentar sem chance de escolha, houve uma redução drástica no consumo de 59 e 66% (300 μL/15mL) das folhas tratadas com o óleo essencial, em relação às folhas não tratadas, para larvas de 3o instar de S. frugiperda e A. gemmatalis respectivamente. Já nos testes com chance de escolha, observou-se a não-preferência das larvas pelas folhas tratadas com óleo essencial de S. guianensis. No teste inibitório de oviposição, houve uma redução drástica de 78 e 97% no número de posturas de S. frugiperda e A. gemmatalis, respectivamente, quando expostas ao óleo essencial. Os bioensaios comportamentais demonstraram que a atividade de grupo foi significativamente reduzida nas duas espécies após exposição à CL10 e CL50 de S. guianensis. Os bioensaios comportamentais demonstraram que a atividade de caminhamento, tanto em grupo quanto em larvas individualizadas, foi significativamente reduzida após exposição à CL50 de S. guianensis, evidenciando o efeito do óleo essencial sobre o comportamento locomotor das espécies em estudo. Em testes com chance de escolha, as larvas de ambas as espécies preferiram permanecer em áreas não tratadas, demonstrando o alto efeito repelente do óleo de S. guianensis. Dessa forma, os resultados apresentados neste trabalho mostram o potencial do óleo essencial de S. guianensis para o desenvolvimento de um método alternativo e eficaz para o controle natural de S. frugiperda e A. gemmatalis. / The recurrent use of chemicals for the control of Spodoptera frugiperda and Anticarsia gemmatalis has led to induction of resistant populations, making it necessary to use essential oils as a control alternative. Thus, this study aimed to evaluate the insecticide and repellent activity of essential oil Siparuna guianensis against S. frugiperda and A. gemmatalis and check the traversal of behavioral patterns of these pests when subjected to the essential oil. According to results obtained, we observed high toxicity of the essential oil of S. guianensis for all stages of S. frugiperda and A. gemmatalis and percentage of repellency of up to 100% (18μL / 900μL) for both species. In the test food fagoinibição no choice, there was a drastic reduction in consumption of 59 and 66% (300 uL / 15mL) leaves treated with the essential oil, compared to untreated leaves for larvae of third instar S. frugiperda and A. gemmatalis respectively. Already in test free choice, it was observed the non-preference of the larvae through the leaves treated with essential oil of S. guianensis. The inhibitory test oviposition, there was a drastic reduction of 78 and 97% in the number of eggs of S. frugiperda and A. gemmatalis, respectively, when exposed to the essential oil. Behavioral bioassays showed that gang activity was significantly reduced in both species after exposure to CL50 S. guianensis. Behavioral bioassays showed that pathway activity, both in group and in individual larvae was significantly reduced after exposure to CL50 S. guianensis, showing the effect of the essential oil on the locomotor behavior of the species under study. In tests with free choice, the larvae of both species preferred to remain in untreated areas, demonstrating the high repellent effect of S. guianensis oil. Thus, the results presented here show the essential oil of S. guianensis potential for the development of an alternative and effective method for natural control of S. frugiperda and A. gemmatalis.
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Les styles de représentation, leurs déterminants et effets comportemenaux : étude empirique des sénateurs français / Representational styles, their determinants and behavioral effect, an empirical study

Schnatterer, Tinette 14 November 2014 (has links)
Les typologies de parlementaires occupent une place centrale dans les études parlementaires.Nous proposons une définition du concept de «style de représentation», centrée sur lescaractéristiques déclarées des parlementaires - permettant de traiter les caractéristiques des élusdans leur diversité en examinant le spectre le plus large possible d’activités représentatives - et desaisir la manière dont ces activités s’articulent entre le niveau local et le niveau national. Ceconcept nous permettra d’étudier empiriquement les liens entre les styles de représentation -dansnotre cas des sénateurs français-, leurs déterminants et leurs effets comportementaux et desurmonter ainsi le descriptivisme propre à beaucoup d'études mobilisant des types parlementaires.L'analyse de cinq styles de représentation des sénateurs français met en évidence que les stylesde représentation sont des réponses aux contraintes et ressources des parlementaires et qu’ilsaffectent de manière systématique le comportement des sénateurs. / Typologies of parliamentarians play a central role in the study of legislators and their behavior. Wepropose a narrow concept of styles of representation, focused on the expressed characteristics ofparliamentarians and taking into account the largest possible spectrum of representational activitiesincluding the local and the national arena of the mandate.This concept enables us to study empirically the links between styles of representations -in ourcase of French senators-, their determinants and behavioral effects and to overcome thedescriptiveness of many studies mobilizing typologies of parliamentarians.The analysis of five styles of representation of the French senators show, that these styles areanswers to the constraints and resources of the parliamentarians and that they affect the senators’behavior in a systematic manner.

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