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Atividade acaricida do extrato metanólico de Acmella oleracea (L.) R.K. Jansen (Asteraceae) e espilantol sobre Rhipicephalus microplus (Acari: Ixodidae) e Dermacentor nitens (Acari: Ixodidae)Cruz, Paula Barroso 29 July 2016 (has links)
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Previous issue date: 2016-07-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo do presente trabalho foi avaliar a atividade carrapaticida do extrato metanólico de Acmella oleracea e do espilantol sobre Rhipicephalus microplus e Dermacentor nitens. O extrato metanólico foi obtido através de maceração com metanol. Desse extrato, foi obtida uma fração diclorometano com 99% de espilantol (que pode ser considerado um composto puro), que também foi testada sobre larvas e fêmeas ingurgitadas de R. microplus e larvas de D. nitens. Para a avaliação da atividade sobre larvas, foi utilizado o teste de pacote de larvas modificados e o extrato metanólico e a fração diclorometano (99% de espilantol) foram testadas em concentrações de 0,2 a 50,0 mg/mL. No teste de tempo letal, também foi utilizado a técnica de pacote de larvas, o extrato metanólico foi usado na concentração de 12,5 mg/mL e a avaliação do percentual de mortalidade foi feita após 15, 30, 45, 60, 75, 90, 120 minutos e 24 horas. Nesse teste foi feito o cálculo de tempo letal 50% (TL50). O teste com fêmeas ingurgitadas foi feito apenas com R. microplus, sendo testadas concentrações de 25 a 200 mg/mL do extrato metanólico e concentrações entre 2,5 a 20,0 mg/mL para o espilantol. O extrato metanólico ocasionou mortalidade de 100% das larvas de R. microplus e D. nitens a partir de concentrações de 3,1 e 12,5 mg/mL, respectivamente. O espilantol resultou em mortalidade de 100% para larvas de R. microplus a partir da concentração 1,6 mg/mL e de 12,5 mg/mL para D. nitens. No experimento de tempo letal, a mortalidade foi de 100% para larvas de R. microplus e D. nitens após 120 minutos e 24 horas, com TL50 de 38 e 57 minutos. No teste com fêmeas, o peso da massa de ovos e percentagem de eclosão dos grupos tratados com concentrações iguais e/ou superiores a 50,0 mg/mL do extrato metanólico apresentaram redução significativa (p> 0,05) em relação ao controle, enquanto o espilantol provocou redução significativa do peso da massa de ovos e percentagem de eclosão em concentrações de 10,0 mg/mL e 2,5 mg/mL, respectivamente. As fêmeas tratadas com 200,0 mg/mL do extrato morreram antes de iniciar o processo de oviposição, resultando em eficácia de 100%, enquanto a melhor eficácia para espilantol foi de 92,9% na concentração de 20,0 mg/mL. Portanto, é possível concluir que o extrato metanólico da A. oleracea e o espilantol apresentam atividade acaricida sobre R. microplus e D. nitens. / We evaluate the acaricidal activity of Acmella oleracea methanol extract and spilanthol on Rhipicephalus microplus and Dermacentor nitens. The methanol extract was made through maceration with methanol. From this extract, a dichloromethane fraction with approximately 100% spilanthol was obtained and tested on R. microplus larvae and engorged females and D. nitens larvae. For evaluation against larvae, modified larvae test packages were used, and both methanol extract and the dichloromethane fraction were tested at concentrations of 0.2 to 50.0 mg/mL. The larvae package technique was also used in the lethal time (LT) test, with methanol extract at a concentration of 12.5 mg/mL and the mortality percentage assessment was made after 15, 30, 45, 60, 75, 90, 120 minutes and 24 hours. The lethal time calculation 50% (LT50) was performed in this test. The engorged female test was done with R. microplus only, at concentrations of 25 to 200 mg/mL for methanol extract and 2.5 to 20.0 mg/mL for spilanthol. The methanol extract caused 100% mortality of the R. microplus and D. nitens larvae at concentrations from 3.1 and 12.5 mg/mL, respectively. Spilanthol resulted in 100% mortality for R. microplus larvae at concentration from 1.6 mg/mL and 12.5 for D. nitens. In the lethal time essay using the methanol extract, the mortality rate was 100% for R. microplus and D. nitens larvae after 120 minutes and 24 hours with LT50 of 38 and 57 minutes. In the test of females, the egg mass weight and the hatching percentage of the groups treated with concentrations equal to and/or higher than 100.0 mg/mL of methanol extract showed significant differences (p> 0.05) while spilanthol causes significant reduction of the egg mass weight and hatching percentage at concentrations of 10.0 mg/mL and 2.5 mg/mL, respectively. Females treated with 200.0 mg/mL of extract died before starting the oviposition process, resulting in 100% effectiveness, while the best efficacy for spilanthol was 92.9% at concentration of 20.0 mg/mL. Thus we conclude that the methanol extract of A. oleracea and spilanthol present acaricide activity against R. microplus and D. nitens.
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Influence de l'environnement sur l'évolution des génomes de virus / Influence of the environment on the evolution of virus genomesChateigner, Aurélien 12 December 2014 (has links)
Le but de cette thèse fut d’étudier l’influence de l’environnement sur l’évolution des génomes de baculovirus. Nous avons d’abord caractérisé génétiquement la population naturelle d’AcMNPV par séquençage haut-débit et établi par des bioessais la sensibilité de 4 espèces hôtes au virus. Ensuite, une évolution expérimentale de 10 cycles fut mise en place sur les 4 espèces hôtes, à partir d’une population naturelle d’AcMNPV. Elle nous a permis de caractériser phénotypiquement et génotypiquement les lignées de 10ème génération. Cette expérience nous a montré des trade-off de virulence pour chaque lignée : pour augmenter leur virulence pour l’hôte sur lequel elles ont évolué, les lignées ont perdu en potentiel adaptatif généraliste. De plus, la diversité intra-populationnelle a diminué pour toutes les lignées en fonction de la sensibilité des hôtes. Enfin, en corrélant tous ces résultats nous avons mis en évidence des positions spécifiques du génome, impliquées dans l’adaptation à l’hôte. / The purpose of this thesis was to study the influence of the environment on the evolution of baculovirus genomes. We first genetically characterised the AcMNPV natural population by high-throughput sequencing and established the susceptibility of 4 hosts to the virus by bioassays. Then, the AcMNPV natural population was subjected to experimental evolution on the 4 host species for 10 cycles. The 10th generation of the evolved viral lines were then phenotypically and genotypically characterised. This experiment showed a virulence trade-off for each line: to increase their virulence to the host on which they evolved, the lines have lost generalist adaptive potential. Furthermore, intra-population diversity decreased for all the lines regardless of host susceptibility. Lastly, by correlating all these results we found specific genome positions involved in host adaptation.
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