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Aux origines du séisme du Teil
No full textFin 2019, un tremblement de terre d'une ampleur exceptionnelle pour
la région se déclenche en Ardèche. S'il n'y a pas de victimes, les destructions
du village du Teil sont importantes. Les particularités de l'événement
et la présence d'une grande carrière de ciment, à l'aplomb de la faille qui
a rompu, interrogent les scientifiques. Serait-il d'origine anthropique
Vector-borne diseases : recent developments in epidemiology and control
No full textThe implementation of sustainable control strategies aimed at disrupting the transmission of vector-borne pathogens requires a comprehensive knowledge of the vector ecology in the different eco-epidemiological contexts, as well as the local pathogen transmission cycles and their dynamics. However, even when focusing only on one specific vector-borne disease, achieving this knowledge is highly challenging, as the pathogen may exhibit a high genetic diversity and multiple vector species or subspecies and host species may be involved. In addition, the development of the pathogen and the vectorial capacity of the vectors may be affected by their midgut and/or salivary gland microbiome. The recent advent of Next-Generation Sequencing (NGS) technologies has brought powerful tools that can allow for the simultaneous identification of all these essential components, although their potential is only just starting to be realized. We present a metabarcoding approach that can facilitate the description of comprehensive host-pathogen networks, integrate important microbiome and coinfection data, identify at-risk situations, and disentangle the transmission cycles of vector-borne pathogens.This powerful approach should be generalized to unravel the transmission cycles of any pathogen and their dynamics, which in turn will help the design and implementation of sustainable, effective, and locally adapted control strategies
Sorting the wheat from the chaff : a review of BINs associated with groupers of Vietnam and the implications for species identification from DNA barcoding
No full textThe Epinephelidae is a marine fish family that has been the focus of worldwide taxonomical attention due to its economic value. Recent molecular-based phylogenies have improved understanding of species diversity within this family. Nonetheless, species misidentification or hybridization has led to a barcode index number (BIN) being associated with several species, which hampers a clear species identification within the BOLD system. In this study, grouper diversity in Vietnam was investigated to check the species inventory, provide a DNA barcode library for Vietnam, and reevaluate BINs associated with some species that are present in Vietnam. To this end, 157 specimens were barcoded corresponding to 30 species and 31 BINs. Nine species were new records, bringing to 49 the number of species inventoried for Vietnam. In BOLD, these species are associated with 75 BINs, 31 species being represented by more than one BIN. A careful review of these BINs, considering the present results from Vietnam, the species composition and frequency of each BIN in BOLD, and reference species sequences from phylogenetic studies, revealed those misidentified or hybrid specimens that artificially increased the number of BINs per species. After appropriate revision, 15 species still remained associated with more than one BIN. A phylogeographic analysis of these species demonstrated that most of the BINs derived from evolutionary lineages with geographic distributions that match well known biogeographic units in the Indo-Pacific. Beyond the species identification, these multiple BINs of each species can be used to track the biogeographic origin of each of the associated specimens
Groundwater licensing and its challenges
No full textThe registering and/or licensing of groundwater abstraction is held as a "best practice" in the control of groundwater use and a necessary step toward volumetric management of resources. Yet, groundwater licensing and legalization processes in areas with many scattered (often agricultural) users tend to face severe difficulties and are rarely successful. Based on a global survey on groundwater governance, this article revisits the reasons for the users' lack of interest, the failure of most legalization/licensing processes, and the frequent lack of both capacity and the political will of government agencies in conducting such processes. It identifies a groundwater licensing dilemma that explains why governments deploy too little effort too late, and finally proposes a few steps and principles to be considered when deciding whether licensing is achievable and how to increase the likelihood of success
Search for neutrino counterparts of gravitational-wave events detected by LIGO and Virgo during run O2 with the ANTARES telescope
No full textAn offline search for a neutrino counterpart to gravitational -wave (GW) events detected during the second observation run (02) of Advanced-LIGO and Advanced Virgo performed with ANTARES data is presented. In addition to the search for long tracks induced by pp, (17i,) charged current interactions, a search for showering events induced by interactions of neutrinos of any flavour is conducted. The severe spatial and time coincidence provided by the gravitational -wave alert allows regions above the detector horizon to be probed, extending the ANTARES sensitivity over the entire sky. The results of this all -neutrino -flavour and all -sky time dependent analysis are presented. The search for prompt neutrino emission within 500 s around the time of six GW events yields no neutrino counterparts. Upper limits on the neutrino spectral fluence and constraints on the isotropic energy radiated via high-energy neutrinos (from a few TeV to a few tens of PeV) are set for each GW event analysed
Giant landslide triggerings and paleoprecipitations in the Central Western Andes : the aricota rockslide dam (South Peru)
No full textThe central part of the Western Andes holds an exceptional concentration of giant paleolandslides involving very large volumes of rock material (v > km(3)). While those gravitational slope failures are interpreted consensually as an erosional response to the geodynamic activity of the Andes (relief formation and tectonic activity), the question of their triggering mechanisms remains enigmatic. To clarify the respective roles of climatic versus seismic forcing on the Andean landslides, new temporal constraints on paleo movements are essential. Here, we focus on one of those giant slope failures, the Aricota giant rockslide that damned the Locumba valley in southern Peru. We conducted fieldwork, high-resolution DEM analysis and cosmogenic nuclide dating to decipher its development history and failure mechanisms. Our results point to the occurrence of two successive events. A giant failure mobilizing a rock volume of ca. 2 km(3) first produced a dam at 17.9 +/- 0.7 ka. Considering its height of ca. 600 m, the Aricota rockslide dam is one of the three largest landslide dams worldwide. At 12.1 +/- 0.2 ka, a second event produced ca. 0.2 km(3) of material, and the rock-avalanche debris spread out over the dam. As the chronology of those two events is pointing to the two main paleoclimatic pluvial periods in this region (Heinrich Stadial 1a and Younger Dryas), we favor the interpretation of a climatic forcing. At a regional scale, the concomitant aggradation of alluvial terraces and fan systems along the nearby valleys highlights higher regional erosion, sediments supply and mass-wasting events during those paleoprecipitation events and strengthens this conclusion
Sexual transmission of Zika virus on Twitter : a depoliticised epidemic
No full textDuring global health crises, different narratives regarding infectious disease epidemics circulate in traditional media (e.g. news agencies, television channels) and social media. Our study investigated the narratives related to sexual transmission of Zika virus that circulated on Twitter during a public health emergency and analyzed the relationship between information on Twitter and on traditional media. We examined 10,748 tweets posted during the peaks of Twitter activity between January and March 2016. Posts in English, Spanish, French, and Portuguese and websites linked to tweets were manually reviewed and analyzed thematically. During the study period, there were three peaks of Twitter activity related to the sexual transmission of Zika. Most tweets in the first peak (n = 412) had humorous/sarcastic content (55%). Most tweets in the second and third peaks (n = 5,154 and n = 5,182, respectively) disseminated information (>93%). Across languages, textual and visual content on the websites were predominantly placed online by traditional media and highlighted epidemiological narratives published by public health agencies, with little or no mention of the concerns or experiences of individuals most affected by Zika. Prioritising epidemiological/clinical aspects of epidemics may have a depoliticising effect and contribute to overlooking socio-economic determinants of the Zika epidemic and issues related to reproductive justice
Voluntary medical male circumcision and HIV in Zambia : expectations and observations
No full textThe study analysed the HIV/AIDS situation in Zambia six years after the onset of mass campaigns of Voluntary Medical Male Circumcision (VMMC). The analysis was based on data from Demographic and Health Surveys (DHS) conducted in 2001, 2007 and 2013. Results show that HIV prevalence among men aged 15-29 (the target group for VMMC) did not decrease over the period, despite a decline in HIV prevalence among women of the same age group (most of their partners). Correlations between male circumcision and HIV prevalence were positive for a variety of socioeconomic groups (urban residence, province of residence, level of education, ethnicity). In a multivariate analysis, based on the 2013 DHS survey, circumcised men were found to have the same level of infection as uncircumcised men, after controlling for age, sexual behaviour and socioeconomic status. Lastly, circumcised men tended to have somewhat riskier sexual behaviour than uncircumcised men. This study, based on large representative samples of the Zambian population, questions the current strategy of mass circumcision campaigns in southern and eastern Africa
Increased prevalence of neurocognitive impairment in aging people living with human immunodeficiency virus : the anrs ep58 hand 55-70 study
No full textBackground.There are limited data on the comparative prevalence of neurocognitive impairment (NCI) in aging people living with human immunodeficiency virus (PLHIV) and people not living with HIV. Methods.This was a cross-sectional study of PLHIV randomly matched by age (±4 years), gender, and education with 5 HIV-uninfected individuals from the CONSTANCES cohort. PLHIV were fluent in French and sequentially included during routine outpatient visits if aged 55-70 years, with HIV viral load -200 cells/uL in the past 24 and 12 months, respectively. The primary outcome was NCI as defined by the Frascati criteria. Multivariate normative comparison (MNC) and -1.5 standard deviations in >-2 neurocognitive domains were secondary outcomes of NCI. Results.Two hundred PLHIV were matched with 1000 controls. Median age was 62 years, and 85% were men. In PLHIV, the median T-CD4 lymphocyte level was 650 cells/uL, and median nadir T-CD4 lymphocyte level was 176 cells/uL. NCI was found in 71 (35.5%) PLHIV and in 242 (24.2%) controls (odds ratio [OR], 1.74; 95% confidence interval [CI], 1.25, 2.41). After adjusting for confounders, HIV remained significantly associated with NCI (OR, 1.50; 95% CI, 1.04, 2.16). Adjusted results were similar with NCI defined by MNC (ORMNC, 2.95; 95% CI, 1.13, 3.50) or -1.5 SD (OR-1.5, 2.24; 95% CI, 1.39, 3.62). Conclusions.In this matched study of aging individuals, HIV was significantly associated with an increased risk of NCI after adjusting for major confounders. Results were confirmed with more stringent NCI classifications
