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Sobriété environnementale et évaluation du risque écologique soutenable
No full textInternational audienceDans le cadre des stratégies de développement durable des organisations, l'évaluation de la dimension éthique du développement économique, conduit à mesurer leur responsabilité environnementale à partir des « empreintes » ou des coûts liés à la pression qu'elles exercent sur l'environnement pour satisfaire l'offre et la demande des ressources rares renouvelables. Le risque écologique soutenable représente le montant de cette pression nécessaire pour créer de la valeur dans le cadre de la sobriété environnementale. Deux profils de développement s'en dégagent. Le pays à forte responsabilité écologique ayant des avoirs de réserves de ressources renouvelables produisant une faible valeur et le pays à faible responsabilité écologique vivant à crédit de ressources renouvelables produisant une forte valeur grâce aux importations des ressources. La constitution des stocks de ressources renouvelables par la photosynthèse artificielle améliore la sobriété environnementale et permet de réaliser une valeur durable. Mots de passe Sobriété environnementale, risque écologique soutenable, empreinte carbone, empreinte écologique, biocapacité
Murine in utero exposure to simulated complex urban air pollution disturbs offspring gut maturation and microbiota during intestinal suckling-to-weaning transition in a sex-dependent manner
No full textInternational audienceBackground Emerging data indicate that prenatal exposure to air pollution may lead to higher susceptibility to several non-communicable diseases. Limited research has been conducted due to difficulties in modelling realistic air pollution exposure. In this study, pregnant mice were exposed from gestational day 10–17 to an atmosphere representative of a 2017 pollution event in Beijing, China. Intestinal homeostasis and microbiota were assessed in both male and female offspring during the suckling-to-weaning transition.Results Sex-specific differences were observed in progeny of gestationally-exposed mice. In utero exposed males exhibited decreased villus and crypt length, vacuolation abnormalities, and lower levels of tight junction protein ZO-1 in ileum. They showed an upregulation of absorptive cell markers and a downregulation of neonatal markers in colon. Cecum of in utero exposed male mice also presented a deeply unbalanced inflammatory pattern. By contrast, in utero exposed female mice displayed less severe intestinal alterations, but included dysregulated expression of Lgr5 in colon, Tjp1 in cecum, and Epcam , Car2 and Sis in ileum. Moreover, exposed female mice showed dysbiosis characterized by a decreased weighted UniFrac β -diversity index, a higher abundance of Bacteroidales and Coriobacteriales orders, and a reduced Firmicutes/Bacteroidetes ratio.Conclusion Prenatal realistic modelling of an urban air pollution event induced sex-specific precocious alterations of structural and immune intestinal development in mice
First-Dose Coronavirus 2019 Vaccination Coverage among the Residents of Long-Term Care Facilities in France
No full textInternational audienceBackground: Long-term care facilities (LTCFs) experienced severe burden from the Coronavirus 2019 (COVID-19), and vaccination against SARS-CoV-2 is a major issue for their residents. Objective: The objective of this study was to estimate the vaccination coverage rate among the residents of French LTCFs. Method: Participants and settings: 53 medical coordinators surveyed 73 LTCFs during the first-dose vaccination campaign using the BNT162b2 vaccine, conducted by health authorities in January and early February 2021. Measurements: in all the residents being in the LTCF at the beginning of the campaign, investigators recorded age, sex, history of clinical or asymptomatic COVID-19, serology for SARS-CoV-2 or severe allergy, current end-of-life situation, infectious or acute disease, refusal of vaccination by the resident or by the representative person of vaccine, and the final status, vaccinated or not. Results: Among the 4,808 residents, the average coverage rate for COVID-19 vaccination was 69%, and 46% of the LTCFs had a coverage rate <70%. Among unvaccinated residents, we observed more frequently a history of COVID-19 or a positive serology for SARS-CoV-2 (44.6 vs. 11.2% among vaccinated residents, p < 0.001), a history of severe allergy (3.7 vs. 0.1%, p < 0.001), end-of-life situation (4.9 vs. 0.3%, p < 0.001), current infectious or acute illness (19.6 vs. 0.3%, p < 0.001), and refusal of vaccination by residents or representative persons (38.9 vs. 0.4%, p < 0.001). Conclusions: About 3 out of 10 residents remained unvaccinated, and half of the LTCFs had a coverage rate <70%. This suggests that COVID-19 will remain a threat to many LTCFs after the vaccination campaigns
Trajectoire paysagère des digues fluviales confrontées aux risques côtiers : le cas des marais de la Dives (Calvados, France)
No full textInternational audienceEn territoire côtier, les espaces agricoles endigués sont aujourd’hui menacés par une conjonction de facteurs, qui en compromettent l’existence parfois millénaire. Dans les marais de la Dives (Calvados, France), le transfert de la compétence Gestion des milieux aquatiques et prévention des inondations (GEMAPI) ainsi que le changement climatique, ajoutent à l’incertitude du devenir de digues déjà en mauvais état. À partir d’une analyse géohistorique et d’une enquête menée auprès des habitants dans le cadre du programme de recherche ANR DIGUES, cette contribution interroge les scénarios d’évolution possibles des digues, au regard de la trajectoire paysagère du marais. Les résultats amènent à nuancer le seul critère du coût économique du maintien des ouvrages, en montrant que l’abandon des digues des marais pourrait en réalité accentuer la vulnérabilité du littoral urbanisé
Effect of cooling rate on the microstructures of three low carbon alloys with different manganese and molybdenum contents
No full textInternational audienceLow-alloy 16 to 20MND5 steels are used for the production of nuclear reactor components. During manufacturing, austenitization is followed by a quench; different types of microstructures are formed during this step. Characterizing the impact of Mo and Mn and of cooling rate on these microstructures can help understand how mechanical properties will evolve during tempering and ageing. The impact of molybdenum and manganese, as well as the impact of the cooling rate, were studied on microstructures of three model alloys: FeCMo, FeCMn and FeCMoMn. This was done using continuous cooling transformation (CCT) diagrams and electron backscattering diffraction (EBSD) characterizations. FeCMoMn was found to be a good model for 16 to 20MND5 steels, based on its CCT diagram and hardness. The presence of molybdenum or manganese did not modify the misorientation angle/axis pairs of martensite. In bainitic microstructures however, the presence of Mn seemed to favor the presence of block boundaries with a misorientation about 59° [433]. On the prior austenitic grain (PAG) level, the impact of the cooling rate was rather continuous, from martensite to slowly cooled bainite, and the same regardless of the composition, with the presence of block and sub-block boundaries. The microstructure became coarser with decreasing cooling rate, with fewer crystallographic orientations per PAG
Comparative seasonal abundance and diversity of populations of the Pseudomonas syringae and Soft Rot Pectobacteriaceae species complexes throughout the Durance River catchment from its French Alps sources to its delta
No full textFlowing surface waters (rivers, creeks, streams) are integrators of biological, chemical and physical processes occurring in a catchment and they link catchment land cover from the headwaters to the outlet. The dynamics of human and animal pathogens in catchments have been widely studied in a large variety of contexts allowing the optimization of disease risk reduction. In parallel, there is an emerging awareness that crop pathogens might also be disseminated via surface waters especially when they are used for irrigation. However, there are no studies on the extent to which potential plant pathogens are present – nor about their dynamics - along the full course of a catchment. We do not know if they are confined to regions close to crops or if they are present throughout a catchment. Here we have compared the seasonal dynamics of populations of the Pseudomonas syringae (Psy) and the Soft Rot Pectobacteriaceae (SRP) species complexes along a 270 km stretch of the Durance River from the upstream alpine reaches to the downstream agricultural production areas at the confluence with the Rhone River at Avignon. Among 168 samples collected at 21 sites in fall, winter, spring and summer of 2016 and 2017, Psy strains were detected at all sampling sites and in 156 of the samples at population densities up to 105 bacteria L−1. In contrast, SRP strains were detected in 98 of the samples, mostly from the southern part of the river, at population densities that did not exceed 3 × 104 bacteria L−1. Among the aquatic parameters that were characterized at each sampling site (total culturable bacteria, temperature, conductivity, concentrations of dissolved organic carbon (DOC), P043−, NH4+, N02− and N03−), temperature was the only factor that explained a significant amount of the variability in population size for both species complexes. Psy densities decreased with increasing temperature whereas SRP densities increased with increasing temperature. River-borne populations of SRP were composed mainly of Pectobacterium versatile and P. aquaticum that have little known epidemiological importance. Only a few strains of Pectobacterium and Dickeya species reputed for their epidemiological impact were observed. In contrast, Psy populations at all sites were dominated by a genetic lineage of phylogroup 2 known from other studies for its broad host range and its geographic and habitat ubiquity. These results suggest that strains of SRP with pathogenic potential to plants have lower competence for saprophytic survival (in freshwaters) than do potentially pathogenic strains of Psy and that their presence in river water is probably much more dependent on specific vegetative sources than are pathogenic strains of Psy. Nevertheless, their vegetative sources have not yet been identified. We discuss how to incorporate knowledge of the abundance and diversity of these two groups of plant pathogens in river water into a strategy for anticipating risk for disease outbreaks on crops in a catchment
Regards croisés sur les évolutions et mutations des métiers de BIATSS et d'enseignant et de chercheur
No full textInternational audienc
Prevalence of Self-Reported Venous Thromboembolism and Cardiovascular Risk Factors in Patients with Ulcerative Colitis: The GETAID FOCUS Study
No full textFOCUS Study Group: Benjamin Pariente, Laurent Beaugerie, Phillipe Seksik, Anne Bourrier, Arnaud Bourrreille, Ariadne Desjeux, Guillaume Savoye, Stéphanie Auzou, Guillaume Cadiot, Alban Benezech, Nicolas Mathieu, Georgia Malamut, Karine Amouriaux, Hédia Brixi, Marion Simon, Daniel Benitah, Philippe Ah-Soune, Mathurin Fumery, Gilles Boschetti, Claire Gay, Mathias Vidon, Ginette Fotsing, Benoit Coffin, Cyrielle Gilletta, Jean Marie Reimund, Marie Bonnet-DodelInternational audienceBackground and aims: Patients with inflammatory bowel disease have an increased risk of venous thromboembolism (VTE) and cardiovascular disease (CVD). The study aims to determine the prevalence of CVD and VTE risk factors in a large population of patients with ulcerative colitis (UC).Methods: We conducted a cross-sectional study in 33 French and Belgium referral centers. A questionnaire was developed to explore self-reported risk factors for VTE and CVD, based on the latest international guidelines, in consecutive patients with UC.Results: A total of 1071 patients with UC were included. There were 539 women (50.3%), and the median age of patients was 44 years [32; 57]. The median disease duration was 10 years [6; 17]. In the cohort, 36.5% of patients reported no cardiovascular risk factor (CVRF) and 72% had ≤ 1 CVRF. Regarding cardiovascular risk markers (CVRM) 36.9% of patients reported no CVRM and 78% had ≤ 1 CVRM. Of the 1071 patients, 91.3% of patients reported no VTE strong risk factor and 96% had ≤ 1 VTE moderate risk factor.Conclusion: This is the first cohort specifically designed to assess both VTE and CVD risks in patients with UC. More than one third of patients with UC had no CVRF and around three quarters had ≤ 1 CVRF. In addition, more than nine out of ten patients had no VTE strong risk factor and ≤ 1 moderate risk factor. Physicians should be aware of these factors in their patients
Prediction intervals with controlled length in the heteroscedastic Gaussian regression
No full textWe tackle the problem of building a prediction interval in heteroscedastic Gaussian regression. We focus on prediction intervals with constrained expected length in order to guarantee interpretability of the output. In this framework, we derive a closed form expression of the optimal prediction interval that allows for the development a data-driven prediction interval based on plug-in. The construction of the proposed algorithm is based on two samples, one labeled and another unlabeled. Under mild conditions, we show that our procedure is asymptotically as good as the optimal prediction interval both in terms of expected length and error rate. In particular, the control of the expected length is distribution-free. We also derive rates of convergence under smoothness and the Tsybakov noise conditions. We conduct a numerical analysis that exhibits the good performance of our method. It also indicates that even with a few amount of unlabeled data, our method is very effective in enforcing the length constraint
Essais sur le risque politique et la finance d'entreprise
No full textThe world is now changing with lightening speed. The greatest of those changes are occurring in the political and technological spheres. Geopolitical shifts have brought politics and business closer together. Political upheavals are incessantly reshaping the circumstances in which individuals, societies, and companies operate, which doesn't make markets in total isolation from politics. Politics molds and constrains markets through its rules, norms, and institutions. Trade regimes, sanctions, and national laws, for instance, shape businesses' environment. Tumultuous reverses, such as wars and revolutions, and other minor events, such as social activism and cyber threats, still take firms by surprise. Therefore, firms are forced to plan and act beyond their immediate environment. The meaning of political risk has changed. A few decades ago, political risk could be summarized in governmental actions, such as industry-related regulations or assets seizing in dictatorships. Today, however, governments are no longer the only arbiter. The twenty-first-century political risk has a broader and more complicated meaning. A civil war in Syria results in a refugee crisis in Europe. An anti-Chinese protest in Vietnam fuels stock-outs in the clothing industry in America. Rice and Zegart (2018) define the twenty-first-century political risk as “the probability that a political action could affect a company in significant ways.” Put in the most elemental terms, political actions emphasize the growing impact of risk generators outside army barracks and party headquarters. In today's competitive markets, firms need to consider all risks engendered by the widening array of global political actors, journalists, social activists, documentary filmmakers, etc. Historically, revolutions, nationalization, seizure of assets were the political risk chorus. However, for the modern-day global firms consider this risk on much more and more aspects. Thus, companies, and particularly international firms see the market as a global place and they plan their strategies accordingly. SeaWorld story, among many others, points out that firms can be dramatically blindsided by political actions of small groups of people and the power of individuals charged by connective technologies. The twenty-first-century political environment is an important external factor of uncertainty for firms. It can, therefore, constrain or foster their growth opportunities and survival. This thesis addresses the relationship between the modern-day politics and corporate financial decisions. So far, prior research studies have only focused on country-level and sector-level measures of political risk in the absence of direct ones. This dissertation, instead, traces through the ways in which political risk can affect U.S. firms' behaviour, using a new firm-level proxy to measure the risk. My dissertation is a three-paper compilation of studies related to political risk and corporate finance. In my first paper, I examine the effect of firm-level political risk on corporate cash holdings and cash management. The second paper investigates whether firm-level political risk affects trade credit provision. Finally, the third paper tackles the issues in measurement of political risk and examines the effect of the novel political risk measure on corporate investment and financing decisions.Contexte et problématique Le monde évolue maintenant à une vitesse fulgurante. Les plus importants de ces changements se produisent dans les domaines politique et technologique. Les changements géopolitiques ont rapproché la politique et les entreprises. Les bouleversements politiques modifient sans cesse les circonstances dans lesquelles les individus, les sociétés et les entreprises évoluent, ce qui ne crée pas des marchés totalement isolés de la politique. La politique façonne et contraint les marchés par le biais de ses règles, normes et institutions. Les régimes commerciaux, les sanctions et les lois nationales, par exemple, modifient l'environnement des entreprises. Les revers tumultueux, tels que les guerres et les révolutions, et d'autres événements mineurs, tels que l'activisme social menacent toujours les entreprises. Par conséquent, les entreprises sont obligées de planifier et d'agir au-delà de leur environnement immédiat et étroit. La signification du risque politique a changé. Il y a quelques décennies, le risque politique pouvait se résumer en actions gouvernementales, telles que des réglementations liées à l'industrie. Aujourd'hui, cependant, les gouvernements ne sont plus le seul arbitre. Le risque politique du XXIe siècle a un sens plus large et plus complexe. Une guerre civile en Syrie entraîne une crise de réfugiés en Europe. Une manifestation anti-chinoise au Vietnam entraîne les ruptures de stock dans l'industrie du vêtement en Amérique du Nord. Rice et Zegart (2018) définissent le risque politique du XXIe siècle comme «la probabilité qu'une action politique puisse affecter de manière significative une entreprise». Les actions politiques soulignent donc l'impact croissant des facteurs générateurs de risques en dehors des institutions gouvernementales. Sur les marchés qui se caractérisent par une forte concurrence, les entreprises doivent prendre en compte tous les risques engendrés par les acteurs politiques, les journalistes, les militants dans la société civile, de réalisateurs de documentaires, etc. Historiquement, les révolutions, la nationalisation étaient au cœur du risque politique. Aujourd'hui les entreprises multinationales considèrent ce risque en tenant compte de plusieurs aspects. L'environnement politique du XXIe siècle constitue un important facteur externe d'incertitude pour les entreprises. Il peut donc limiter ou favoriser leurs possibilités de croissance et leur survie. Cette thèse aborde la relation entre le risque politique dans sa nouvelle définition et les décisions financières des entreprises. Jusqu'à présent, les études de recherche antérieures ne portaient que sur les mesures du risque politique au niveau des pays ou des secteurs d'activités en l'absence de mesures directes. Cette thèse retrace la façon dont le risque politique peut influer sur le comportement des entreprises américaines, en utilisant une nouvelle mesure de ce risque. Ma thèse est une compilation de trois études sur le risque politique et les choix financiers des entreprises. Dans mon premier article, j'examine l'effet du risque politique au niveau de l'entreprise sur les encaisses de trésorerie des entreprises. Le deuxième chapitre traite comment le risque politique affecte les crédits commerciaux inter-firmes. Dans le troisième chapitre, une nouvelle mesure du risque politique est développée et son effet sur les choix d'investissement et de financement des entreprises sera examiné