The culture history of Madagascar

Madagascar's culture is a unique fusion of elements drawn from the western, northern, and eastern shores of the Indian Ocean, and its past has fascinated many scholars, yet systematic archaeological research is relatively recent on the island. The oldest traces of visitors are from the first century AD. Coastal settlements, with clear evidence of ties to the western Indian Ocean trading network, were established in several places over the next millennium. Important environmental changes of both plant and animal communities are documented over this period, including the extinctions of almost all large animal species. Urban life in Madagascar began with the establishment of the entrepôt of Mahilaka on the northwest coast of the island in the twelfth century. At about the same time, communities with ties to the trade network were established around the island's coasts. From the fourteenth to the sixteenth century, social hierarchies developed in several regions of the island. During the succeeding two centuries, Madagascar saw the development of state polities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45256/1/10963_2004_Article_BF00997802.pd

Comparative phylogeography of parasitic Laelaps mites contribute new insights into the specialist-generalist variation hypothesis (SGVH)

BACKGROUND: The specialist-generalist variation hypothesis (SGVH) in parasites suggests that, due to patchiness in habitat (host availability), specialist species will show more subdivided population structure when compared to generalist species. In addition, since specialist species are more prone to local stochastic extinction events with their hosts, they will show lower levels of intraspecific genetic diversity when compared to more generalist. RESULTS: To test the wider applicability of the SGVH we compared 337 cytochrome oxidase I mitochondrial DNA and 268 nuclear tropomyosin DNA sequenced fragments derived from two co-distributed Laelaps mite species and compared the data to 294 COI mtDNA sequences derived from the respective hosts Rhabdomys dilectus, R. bechuanae, Mastomys coucha and M. natalensis. In support of the SGVH, the generalist L. muricola was characterized by a high mtDNA haplotypic diversity of 0.97 (±0.00) and a low level of population differentiation (mtDNA Fst= 0.56, p < 0.05; nuDNA Fst = 0.33, P < 0.05) while the specialist L. giganteus was overall characterized by a lower haplotypic diversity of 0.77 (±0.03) and comparatively higher levels of population differentiation (mtDNA Fst = 0.87, P < 0.05; nuDNA Fst = 0.48, P < 0.05). When the two specialist L. giganteus lineages, which occur on two different Rhabdomys species, are respectively compared to the generalist parasite, L. muricola, the SGVH is not fully supported. One of the specialist L. giganteus species occurring on R. dilectus shows similar low levels of population differentiation (mtDNA Fst= 0.53, P < 0. 05; nuDNA Fst= 0.12, P < 0.05) than that found for the generalist L. muricola. This finding can be correlated to differences in host dispersal: R. bechuanae populations are characterized by a differentiated mtDNA Fst of 0.79 (P < 0.05) while R. dilectus populations are less structured with a mtDNA Fst= 0.18 (P < 0.05). CONCLUSION: These findings suggest that in ectoparasites, host specificity and the vagility of the host are both important drivers for parasite dispersal. It is proposed that the SGHV hypothesis should also incorporate reference to host dispersal since in our case only the specialist species who occur on less mobile hosts showed more subdivided population structure when compared to generalist species

Reactor physic and reprocessing scheme for innovative molten salt reactor system

The molten salt reactor is one of the six concepts retained by the Generation IV forum in 2001. Based on the MSRE and MSBR concepts developed by ORNL in the 60s which involve a liquid fuel constituted of fluorine molten salt at a temperature close to 600 8C, new developments with innovative approach and technology have been realized which contribute to strongly improve the concept. The thorium breeder potentiality is closely related to the use of a liquid fuel which is able to be periodically treated. A reprocessing scheme has been established to treat used fuel by extraction of fission products. According to the Gen IV philosophy for closed cycle nuclear reactor, the actinides are sent back in the reactor core. In this way, the wastes radiotoxicity is strongly decreased and the use of natural resource is optimized. This paper describes an innovative reactor concept, the TMSR-NM (non-moderated thorium molten salt reactor), from the nuclear physic point of view and the different steps involving in the reprocessing scheme from the chemical point of view

Visual Servoing

International audienceVisual servoing refers to the use of visual data as input of real-time closed-loop control schemes for controlling the motion of a dynamic system, a robot typically. It can be defined as sensor-based control from a vision sensor and relies on techniques from image processing, computer vision, and control theory

Robot Visual Control

International audienc