Comprendre les comportements face à un risque modéré d’inondation. Etude de cas dans le périurbain toulousain (Sud-Ouest de la France)

Les espaces urbanisés soumis à des risques modérés d’inondation pour les vies humaines sont souvent peu considérés dans les études sur la vulnérabilité aux risques naturels en dépit des enjeux qu’ils représentent en termes de gestion de crise. Comment les riverains y font-ils face au danger et quelles sont leurs « bonnes raisons » d’agir? A partir de l’étude socio-géographique de deux inondations récentes (2000 et 2003) dans la périphérie toulousaine (Sud-Ouest de la France), nous montrons que les caractéristiques de l’aléa dans les vallées étudiées influencent les représentations du risque et par conséquent les motivations à se protéger. Face au risque majeur, la vulnérabilité sociale se trouve ainsi augmentée. Pour améliorer la résilience des populations, il convient d’adapter la communication sur les risques: personnaliser l’information, améliorer la compréhension de l’événement vécu et mobiliser de nouvelles formes de médiation entre gestionnaires et riverains

Radial Distribution of the Dust Comae of Comets 45P/Honda–Mrkos–Pajdusáková and 46P/Wirtanen

There was an unprecedented opportunity to study the inner dust coma environments, where the dust and gas are not entirely decoupled, of comets 45P/Honda–Mrkos–Pajdusáková (45P/HMP) from 2016 December 26 to 2017 March 15, and 46P/Wirtanen from 2018 November 10 to 2019 February 13, both in visible wavelengths. The radial profile slopes of these comets were measured in the R and HB-BC filters most representative of dust, and deviations from a radially expanding coma were identified as significant. The azimuthally averaged radial profile slope of comet 45P/HMP gradually changes from −1.81 ± 0.20 at 5.24 days preperihelion to −0.35 ± 0.16 at 74.41 days postperihelion. Contrastingly, the radial profile slope of 46P/Wirtanen stays fairly constant over the observed time period at −1.05 ± 0.05. Additionally, we find that the radial profile of 46P/Wirtanen is azimuthally dependent on the sky-plane-projected solar position angle, while that of 45P/HMP is not. These results suggest that comets 45P/HMP and 46P/Wirtanen have vastly different coma dust environments and that their dust expansion properties are distinct. As evident from these two comets, well-resolved inner comae are vital for detailed characterization of dust environments. © 2022. The Author(s). Published by the American Astronomical Society.We would like to thank everyone who participated in the data-gathering process. This includes all students from the Lunar and Planetary Laboratory course PTYS 495B/595B (Fall 2018). We would also like to thank the additional organizers of the 4*P Campaign: Matthew Knight (United States Naval Academy) and Tony Farnham (University of Maryland). We would like the thank the Steward Observatory technical staff for the amount of time they dedicated to this project. Finally, we would like to thank the SSO grant No. NNX16A670G (Walt Harris) and the NESSF grant No. 80NSSC18K1241 (Cassandra Lejoly; P.I.: Walt Harris) for allowing this work to be completed. We would also like to thank the Slovak Academy of Sciences grant No. VEGA 2/ 0023/18 (Oleksandra Ivanova) and the Slovak Research and Development Agency under the Contract no. APVV-19-0072 (Oleksandra Ivanova)

Telomeric Trans-Silencing in Drosophila melanogaster: Tissue Specificity, Development and Functional Interactions between Non-Homologous Telomeres

BACKGROUND: The study of P element repression in Drosophila melanogaster led to the discovery of the telomeric Trans-Silencing Effect (TSE), a homology-dependent repression mechanism by which a P-transgene inserted in subtelomeric heterochromatin (Telomeric Associated Sequences, "TAS") has the capacity to repress in trans, in the female germline, a homologous P-lacZ transgene located in euchromatin. TSE can show variegation in ovaries, displays a maternal effect as well as an epigenetic transmission through meiosis and involves heterochromatin and RNA silencing pathways. PRINCIPAL FINDINGS: Here, we analyze phenotypic and genetic properties of TSE. We report that TSE does not occur in the soma at the adult stage, but appears restricted to the female germline. It is detectable during development at the third instar larvae where it presents the same tissue specificity and maternal effect as in adults. Transgenes located in TAS at the telomeres of the main chromosomes can be silencers which in each case show the maternal effect. Silencers located at non-homologous telomeres functionally interact since they stimulate each other via the maternally-transmitted component. All germinally-expressed euchromatic transgenes tested, located on all major chromosomes, were found to be repressed by a telomeric silencer: thus we detected no TSE escaper. The presence of the euchromatic target transgene is not necessary to establish the maternal inheritance of TSE, responsible for its epigenetic behavior. A single telomeric silencer locus can simultaneously repress two P-lacZ targets located on different chromosomal arms. CONCLUSIONS AND SIGNIFICANCE: Therefore TSE appears to be a widespread phenomenon which can involve different telomeres and work across the genome. It can explain the P cytotype establishment by telomeric P elements in natural Drosophila populations

Institutional interactions and economic growth: The joint effects of property rights, veto players and democratic capital

We investigate the possible interaction effects that the extent of property rights protection and separation of powers in a political system have on economic growth. Using analysis of panel data from more than countries over the period 1970-2010 we find that the growth effects of property rights increase when political power is divided among more veto players. When distinguishing between institutional veto players (political institutions) and partisan veto players (fractionalization among political parties), we further find that the growth effects of property rights are driven mainly by checks on the chief executive (in bicameral systems) and primarily found in countries with large stocks of democratic capital

Aspects psychosociaux des stratégies de faire face à une inondation : soutien social, comparaison sociale et rumeur

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