Asymmetrical bloch branes and the hierarchy problem

We investigate a two scalar fields split braneworld model which leads to a possible approach to the hierarchy problem within the thick brane scenario. The model exhibits a resulting asymmetric warp factor suitable for this purpose. The solution is obtained by means of the orbit equation approach for a specific value of one of the parameters. Besides, we analyze the model qualitative behaviour for arbitrary parameters by inspecting the underlying dynamical system defined by the equations which give rise to the braneworld model. We finalize commenting on the metric fluctuation and stability issues.Comment: 8 pages, 7 figure

Homeopatia: uma opção de tratamento da mamite bovina

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Undular bore theory for the modified Korteweg-de Vries-Burgers equation

We consider nonlinear wave structures described by the modified Korteweg-de Vries equation with taking into account a small Burgers viscosity for the case of step-like initial conditions. The Whitham modulation equations are derived which include the small viscosity as a perturbation. It is shown that for long enough time of evolution this small perturbation leads to stabilization of cnoidal bores and their main characteristics are obtained. Applicability conditions of this approach are discussed. Analytical theory is compared with numerical solutions and good agreement is found.Comment: 10 pages, 7 figure

Effects of three pesticides on the avoidance behavior of earthworms in laboratory tests performed under temperate and tropical conditions.

Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the oftenlimited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides

Parâmetros leucocitários de caprinos da raça Moxotó criados no semi-árido cearense.

A influência de algumas variáveis ambientais sobre a fisiologia animal podem ocasionar evidentes oscilações nos elementos constituintes do hemograma em especial do leucograma. Diante da importância das raças caprinas nativas criadas na região Nordeste, objetivou-se com esse estudo conhecer os valores do leucograma de caprinos da raça Moxotó criados no semi-árido cearense, visando determinar os parâmetros específicos para a raça, durante os períodos seco e chuvoso. Foram avaliados 15 animais, sendo cinco machos e dez fêmeas. As colheitas de sangue, num total de 60 amostras, foram realizadas no período da manhã, nos meses de abril e setembro, durante dois anos. Foi possível observar que os valores médios obtidos neste estudo encontram-se dentro da faixa de normalidade citada na literatura, exceto para os valores de bastões, segmentados do machos no período chuvoso e eosinófilos das fêmeas no período seco e chuvoso, que estão acima dos valores considerados normais. Foi observada diferença estatística significativa entre os machos e fêmeas no período seco quanto aos valores de leucócitos totais e segmentados. Observou-se também diferença estatística significativa entre os períodos seco e chuvoso quanto aos valores absolutos de monócitos. Apesar deste estudo, ainda é necessária a realização de maispesquisas com um número maior de animais para a determinação dos parâmetros normais