Sisssy Charles

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Endosymbiotic bacteria are often transmitted vertically from one host generation to the next via oocytes cytoplasm. The generally small number of colonizing bacteria in the oocytes leads to a bottleneck at each generation, resulting in genetic homogenization of the symbiotic population. Nevertheless, in many of the species infected by Wolbachia (maternally(More)
The aim of this work is to study the influence of patch selection on the dynamics of a system describing the interactions between two populations, generically called 'population N' and 'population P'. Our model may be applied to prey-predator systems as well as to certain host-parasite or parasitoid systems. A situation in which population P affects the(More)
When several symbionts infect simultaneously the same host (multiple infections), the interactions between them affect the dynamics of the symbiotic population. Despite their widespread occurrence, associations with multiple vertically transmitted symbionts have attracted little attention. Vertical transmission tends to homogenize the symbiotic population(More)
The effects of parasites on the behavior of their hosts are well documented. For example, parasites may affect the habitat selection of the host individual. We used variables aggregation methods to investigate the way in which parasites affect the spatial pattern of susceptible hosts. We developed a simple epidemiological model, taking into account both the(More)
Ecotoxicology supplies environmental quality criteria mainly based on the potential effects of contaminants on demographic rates of natural populations. Possible impacts through pollutant-induced disruptions of spatial behaviors are totally neglected. Should it be significant to take into account this "second way"? We developed the example of a hypothetical(More)
The aim of this work is to study the effects of different individual behaviours on the overall growth of a spatially distributed population. The population can grow on two spatial patches, a source and a sink, that are connected by migrations. Two time scales are involved in the dynamics, a fast one corresponding to migrations and a slow one associated with(More)
Calotropis gigantea (Asclepiadaceae) is a glabrous or hoary, laticiferous shrubs or small trees, commonly known as “the swallow-wort or milkweed”. Calotropis is used as a traditional medicinal plant. C. gigantea contain chemical constituents are cardenolides, flavonoids, terpenes, pregnanes and a nonprotein amino acid. The latex , leaves, flowers, bark,(More)
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