Éditeur(s) : HAL CCSD
Résumé : International audience
Studying the ecology of Leishmania parasites is essential for understanding and controlling the epidemiology of the diseases they cause. Despite their abundance and diversity in neotropical forests, few studies have been conducted to investigate the potential involvement of Chiroptera in the Leishmania pathogenic complexes. However, phlebotomine sand flies are known to colonize the same anthropized habitat, are attracted to bats, and are able to transmit trypanosomatids. Thus, 216 bats representing 29 species were sampled in the field in different primary and secondary forests of French Guiana where human cutaneous leishmaniases have been reported, together with 62 non-volant mammals. A series of 411 tissue samples representing 47 mammalian species were cultured and screened for the presence of Leishmania spp. by a genus-specific polymerase chain reaction. All 278 individuals surveyed were negative. Thus, bats do not appear to be involved in the Lishmania parasitic cycles in the Guyanas.
The American journal of tropical medicine and hygiene

halsde-00339305
https://hal.archives-ouvertes.fr/halsde-00339305

Éditeur(s) : HAL CCSD World Scientific Publishing
Résumé : International audience
We present a new, alternative interpretation of the vector-tensor multiplet as a two-form in central charge superspace. This approach provides a geometric description of the (nontrivial) central charge transformations ab initio and is naturally generalized to include couplings of Chern-Simons forms to the antisymmetric tensor gauge field, giving rise to a N=2 supersymmetric version of the Green-Schwarz anomaly cancellation mechanism.
ISSN: 0217-751X

hal-00769900
https://hal.univ-antilles.fr/hal-00769900
DOI : 10.1142/S0217751X98000792

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Dynamic Bifurcations

hal-01529542
https://hal.univ-antilles.fr/hal-01529542

Éditeur(s) : HAL CCSD Berlin: A. Asher & Co.
Résumé : International audience
In this work, we compare IASI-retrieved vertical water vapour profiles and related precipitable water over a complex region, namely the Rhine Valley area, during the pre-operational period of IASI exploitation (June?August 2007). Both IASI water vapour mixing ratio profiles and integrated water vapour content are retrieved from L1C radiances spectra using two techniques and compared with water vapour related observations acquired during the Convective and Orographically-induced Precipitation Study (COPS) field campaign that took place in this area at that time (i.e. lidars, radiosoundings and a global positioning system - GPS - station network). This work addresses the issue of IASI vertical spatial resolution and its capability to detect two-layer water vapour structures such as those observed in a mountainous area and which play an important role in convective initiation or inhibition. We found that this capability mostly relies on the type of a-priori background vector (climatology or space-time colocated ECMWF analysis), which is used within the retrieval scheme. Systematic comparison of water vapour products derived from 71 IASI spectra confirms that IASI can retrieve water vapour amounts in 2 km width layers, in the lower troposphere, with an accuracy of approximately 10%.
ISSN: 0369-1845

hal-00923710
https://hal.archives-ouvertes.fr/hal-00923710
https://hal.archives-ouvertes.fr/hal-00923710/document
https://hal.archives-ouvertes.fr/hal-00923710/file/masiello.pdf
DOI : 10.1127/0941-2948/2013/0430

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
In Taiwan, about one third of the lithospheric plate convergence between Eurasia and the Philippine Sea plate is accommodated on the eastern coast across the narrow Longitudinal Valley (LV). The Longitudinal Valley Fault (LVF) is the main seismically active fault zone in this region. However, the spatial distribution of ground deformation due to interseismic loading on locked fault segments remains widely unknown. To address this problem, we use a "permanent scatterer" (PS) interferometric synthetic aperture radar (InSAR) approach for processing the ERS satellite archives. The PS mean velocity maps allow accurately mapping and quantifying the ground deformation all along the LV. Assuming that, close to the surface, the fault plane along the central LVF creeping segment dips 55 degrees to the east, we derive a slip vector at the surface of similar to 25 mm/yr with a mean rake of 70 degrees. In agreement with our PS observations, shallow seismicity indicates a clear change in the fault mechanical behavior of the creeping segment around Fuli town. Finally, we propose a combination of the PS velocity fields for estimating a 3-D map of ground deformation. In the southern part of the LV, the vertical component reveals an uplift of the Coastal Range with respect to the LV of similar to 10 mm/yr. Moreover, between Taitung and Luyeh, the vertical deformation is essentially accommodated along the Luyeh Strand. Finally, north of Rueisuei, the Coastal Range uniformly subsides at similar to 15 mm/yr relative to the western side of the LV. However, a local uplift pattern is detected around latitude 23 degrees 42'.
ISSN: 0148-0227

hal-00595532
https://hal.archives-ouvertes.fr/hal-00595532
DOI : 10.1029/2010JB007898

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The development of Plasmodium falciparum within the Anopheles gambiae mosquito relies on complex vector-parasite interactions, however the resident midgut microbiota also plays an important role in mediating parasite infection. In natural conditions, the mosquito microbial flora is diverse, composed of commensal and symbiotic bacteria. We report here the isolation of culturable midgut bacteria from mosquitoes collected in the field in Cameroon and their identification based on the 16S rRNA gene sequencing. We next measured the effect of selected natural bacterial isolates on Plasmodium falciparum infection prevalence and intensity over multiple infectious feedings and found that the bacteria significantly reduced the prevalence and intensity of infection. These results contrast with our previous study where the abundance of Enterobacteriaceae positively correlated with P. falciparum infection (Boissiere et al. 2012). The oral infection of bacteria probably led to the disruption of the gut homeostasis and activated immune responses, and this pinpoints the importance of studying microbe-parasite interactions in natural conditions. Our results indicate that the effect of bacterial exposure on P. falciparum infection varies with factors from the parasite and the human host and calls for deeper dissection of these parameters for accurate interpretation of bacterial exposure results in laboratory settings.
ISSN: 1932-6203

hal-01546172
https://hal.archives-ouvertes.fr/hal-01546172
DOI : 10.1371/journal.pone.0081663