Cytogenetical characterization of six orb-weaver species and review of cytogenetical data for Araneidae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O inconsciente entendido à luz de Gilles Deleuze e Félix Guattari: intersecções entre a psicanálise de Melanie Klein e a esquizoanálise

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise teórica do problema de Weaver da falha infinita, modo TE magnetotelúrico

É apresentada uma solução totalmente analítica do modelo da falha infinita para o modo TE magnetotelúrico, levando em conta a presença do ar, utilizando como base o trabalho de Sampaio apresentado em 1985, que apresenta uma solução parcialmente analítica e parcialmente numérica – solução híbrida. Naquela solução foram aplicadas oito condições de contorno, sendo que em quatro delas foram encontradas inconsistências matemáticas que foram dirimidas com alterações adequadas nas soluções propostas por Sampaio. Tais alterações propiciaram a chegarse à solução totalmente analítica aqui apresentada. A solução obtida foi comparada com a solução de Weaver, com a de Sampaio e com o resultado do método numérico dos elementos finitos para contrastes de resistividade iguais a 2, 10 e 50. A comparação da solução analítica, para o campo elétrico normalizado, com a solução de elementos finitos mostra que a solução analítica proporcionou resultados mais próximos, em comparação aos fornecidos por Weaver e por Sampaio. Este é um problema muito difícil, aberto para uma solução analítica definitiva. A solução apresentada aqui é, nesta direção, um grande passo.

Noção de feminilidade em Melanie Klein: subjetivações para além de um registro fálico

Pós-graduação em Psicologia - FCLAS

Cuticular Hydrocarbon Variation of Castes and Sex in the Weaver Ant Camponotus textor (Hymenoptera: Formicidae)

Cuticular hydrocarbons play important roles as chemical signatures of individuals, castes, sex and brood. They also can mediate the regulation of egg laying in ants, by informing directly or indirectly the reproductive status of queens. In this study we asked whether cuticular hydrocarbon profiles are correlated with castes and sex of Camponotus textor. Cuticular hydrocarbons were extracted from part of a mature colony (80 workers, 27 major workers, 27 queens, 27 virgin queens and 27 males). Results showed that cuticular hydrocarbons varied quantitatively and qualitatively among the groups and this variation was sufficiently strong to allow separation of castes and genders. We discuss the specificity of some compounds as possible regulatory compounds of worker tasks and reproduction in C. textor.

Melanie Kurt als Fidelio, Rollenbild, in: Ludwig van Beethoven: Fidelio

Signatur des Originals: S 36/F05084

Melanie Kurt als Fidelio, Rollenbild, in: Ludwig van Beethoven: Fidelio

Signatur des Originals: S 36/F05085

Northwards and eastwards velocities extracted from a historical run (for the year 2000) of the UVic Earth System Climate Model of Weaver et al. (2001)

This study provides a theoretical assessment of the potential bias due to differential lateral transport on multi-proxy studies based on a range of marine microfossils. Microfossils preserved in marine sediments are at the centre of numerous proxies for paleoenvironmental reconstructions. The precision of proxies is based on the assumption that they accurately represent the overlying watercolumn properties and faunas. Here we assess the possibility of a syn-depositional bias in sediment assemblages caused by horizontal drift in the water column, due to differential settling velocities of sedimenting particles based on their shape, size and density, and due to differences in current velocities. Specifically we calculate the post-mortem lateral transport undergone by planktic foraminifera and a range of other biological proxy carriers (diatoms, radiolaria and fecal pellets transporting coccolithophores) in several regions with high current velocities. We find that lateral transport of different planktic foraminiferal species is minimal due to high settling velocities. No significant shape- or size-dependent sorting occurs before reaching the sediment, making planktic foraminiferal ideal proxy carriers. In contrast, diatoms, radiolaria and fecal pellets can be transported up to 500km in some areas. For example in the Agulhas current, transport can lead to differences of up to 2°C in temperature reconstructions between different proxies in response to settling velocities. Therefore, sediment samples are likely to contain different proportions of local and imported particles, decreasing the precision of proxies based on these groups and the accuracy of the temperature reconstruction.

Antagonistic interactions between the african weaver ant Oecophylla longinoda and the parasitoid Anagyrus pseudococci potentially limits suppression of the invasive mealybug Rastrococcus iceryoides

The ant Oecophylla longinoda Latreille forms a trophobiotic relationship with the invasive mealybug Rastrococus iceryoides Green and promotes the latter's infestations to unacceptable levels in the presence of their natural enemies. In this regard, the antagonistic interactions between the ant and the parasitoid Anagyrus pseudococci Girault were assessed under laboratory conditions. The percentage of parasitism of R. iceryoides by A. pseudococci was significantly higher on "ant-excluded" treatments (86.6% ± 1.27%) compared to "ant-tended" treatments (51.4% ± 4.13%). The low female-biased sex-ratio observed in the "ant-tended" treatment can be attributed to ants' interference during the oviposition phase, which disrupted parasitoids' ability to fertilize eggs. The mean foraging time, host handling time and number of successful oviposition in "ant-excluded" treatment were significantly higher compared to "ant-tended" treatments. When ant workers were allowed access to sterilized sand grains, mummified and unmummified R. iceryoides, they selectively removed the mummified mealybugs, indicating that they recognized the mummies as potential foods (1.2 ± 0.46 to 7.8 ± 1.17 mummies at 10 min intervals for 2 h). Percentage emergence from mummified R. iceryoides removed by the ants was significantly lower compared to emergence from mummies not exposed to ants. Although, host seeking parasitoids frequently evaded attacks, some were killed by the foraging ant workers (2.0 ± 0.38 to 6.0 ± 0.88 at 10 min intervals for 2 h). These results suggest for the first time that the presence of O. longinoda has a detrimental effect on the abundance, reproductive success and possibly oviposition strategy of female parasitoids, which might be a delimiting factor in field conditions if both natural enemies are to be recommended for use within the same agro-ecosystem.