96 research outputs found

    The INDC counter, aggregation of national contributrions and 2°C trajectories

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    Rapport du groupe interdisciplinaire sur les contributions nationalesConsidering that limiting global warming to below 2°C implies a CO2 budget not to be exceeded and near-zero emissions by 21OO (IPCC), we can assess global 2030 greenhouse gas emissions implied by INDCs in comparison to long-term trajectories. Ahead of the COP21, we estimate that submitted INDCs would bring global greenhouse gas emissions in the range of 55 to 64 GtC02eq in 2030.Under this assumption,global emissions in 2030 are thus higher than the level of 51GtC0 2eq for the year 2012. However, this is not in contradiction with a peaking of global emissions that can only be expected after 2020, given in particular the projected dynamics of emissions in China and other developing countries.The published INDCs represent a significant step towards trajectories compatible with the 2°C goal,but remain insufficient to join trajectories presenting a reasonable probability of success.ln order to increase the chance of meeting the 2°C objective, the ambition of the short-term contributions needs to be strengthened in future negotiations.ln order to sustain a high pace in emissions reductions after 2030,structural measures are also needed, which, in order to have a rapi impact, should be prepared as early as possible. Continued efforts are needed to accelerate the development of low carbon solutions on the one hand,and demonstrate the feasibility of negative emissions on the other hand

    Experimental Infection of Captive Red Foxes (Vulpes vulpes) with Mycobacterium bovis

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    [EN] In Europe, animal tuberculosis (TB) due to Mycobacterium bovis involves multi-host communities that include cattle and wildlife species, such as wild boar (Sus scrofa), badgers (Meles meles) and red deer (Cervus elaphus). Red fox (Vulpes vulpes) infections have also been recently reported in some TB endemic regions in the Iberian Peninsula and France, with some of the infected animals shedding M. bovis in urine and feces. In order to understand the pathogenesis of M. bovis infection in foxes and the associated risk of transmission, 12 captive foxes (6 females and 6 males) were inoc-ulated orally with 2 × 107 colony-forming units of a French field isolate of M. bovis. Clinical samples (urine, feces and oropharyngeal swabs) were collected every four weeks and tested for molecular diagnosis and bacteriology. Serological responses were measured by IDEXX M. bovis Ab Test and Multi Antigen Print Immunoassay (MAPIA). At a post-mortem examination performed 12 weeks post infection (wpi), tissues were tested for the presence of M. bovis and associated gross and microscopic TB-like lesions. M. bovis was detected by PCR in bladder swabs of 3 animals at 12 wpi. It was also detected pre-mortem at different time points of the experiment in the oropharyngeal mu-cus of three individuals and in the feces of nine foxes, with two of them confirmed by bacteriology. All 12 foxes had at least 4 PCR positive samples (out of the 23 tested), and all but 1 fox had at least 1 culture positive sample. The culture negative fox was PCR positive in both retropharyngeal and mesenteric lymph nodes, in line with the results of the other animals. Seroconversion was observed in all foxes except one during the experiment, and in nine at the final time point. No gross visible lesions were found in any animal at the post-mortem examination. The histology showed small granulomas within the lymph nodes, tonsils, liver and lungs from eight animals, with the presence of few acid-fast bacilli. These results confirmed that all orally-infected foxes developed mild TB lesions but they were able to shed mycobacteria in about 75% of cases, 1 month post-infection (9 out 12 foxes). These results show that it is possible to induce typical TB infection experimentally in captive foxes, with measurable M. bovis excretion; such an experimental system could be useful for future evaluations of diagnostics and vaccines in this speciesSIThe French Ministry of Agriculture mainly financed the sampling and the analyses in the framework of the RFSA call on TB projects (Anses-DGAl credit agreement RFSA 2017-326). The animals and the running cost of the BSL3 facilities and technical resources were financed by the European Commission in the context of Horizon 2020?Vetbionet Transnational Access Activities (TNA) call. This work is also partially the result of the I+D+i research project RTI2018-096010-B-C21, funded by the Spanish MCIN/AEI/10.13039/501100011033/ Ministry of Science, Innovation and the European Regional Development Funds (FEDER Una manera de hacer Europa), and of PCTI 2021? 2023 (GRUPIN: IDI2021-000102) funded by Principado de Asturias and FEDE

    Et j’avance
 (illustration)

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    Le triangle des Bermudes (illustration)

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    Je place
 (illustration)

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    L’utilisation des progiciels de statistiques dans la recherche en sciences humaines

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    L’un des principaux usages de l ’informatique en recherche se situe au niveau du traitement des donnĂ©es. De nos jours, les traitements courants de donnĂ©es s’effectuent essentiellement Ă  l’aide de progiciels de statistiques. Les progiciels S.P.S.S. et S.A.S. sont les plus couramment utilisĂ©s en recherche en sciences sociales. Quelques avantages et dĂ©savantages de ces deux progiciels, ainsi que leurs possibiitĂ©s et leurs limites d’utilisation sont d’abord prĂ©sentĂ©s. Des recommandations relatives Ă  une optimisation des bons usages d’un progiciel de statistiques sont ensuite Ă©laborĂ©es : prĂ©alables, Ă©tapes de la programmation du progiciel et rĂšgles de programmation

    Higher-level classification of the Archaea: evolution of methanogenesis and methanogens

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    We used a phylogenetic approach to analyze the evolution of methanogenesis and methanogens. We show that 23 vertically transmitted ribosomal proteins do not support the monophyly of methanogens, and propose instead that there are two distantly related groups of extant archaea that produce methane, which we have named Class I and Class II. Based on this finding, we subsequently investigated the uniqueness of the origin of methanogenesis by studying both the enzymes of methanogenesis and the proteins that synthesize its specific coenzymes. We conclude that hydrogenotrophic methanogenesis appeared only once during evolution. Genes involved in the seven central steps of the methanogenic reduction of carbon dioxide (CO2) are ubiquitous in methanogens and share a common history. This suggests that, although extant methanogens produce methane from various substrates (CO2, formate, acetate, methylated C-1 compounds), these archaea have a core of conserved enzymes that have undergone little evolutionary change. Furthermore, this core of methanogenesis enzymes seems to originate (as a whole) from the last ancestor of all methanogens and does not appear to have been horizontally transmitted to other organisms or between members of Class I and Class II. The observation of a unique and ancestral form of methanogenesis suggests that it was preserved in two independent lineages, with some instances of specialization or added metabolic flexibility. It was likely lost in the Halobacteriales, Thermoplasmatales and Archaeoglobales. Given that fossil evidence for methanogenesis dates back 2.8 billion years, a unique origin of this process makes the methanogenic archaea a very ancient taxon

    Higher-level classification of the Archaea: evolution of methanogenesis and methanogens

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    We used a phylogenetic approach to analyze the evolution of methanogenesis and methanogens. We show that 23 vertically transmitted ribosomal proteins do not support the monophyly of methanogens, and propose instead that there are two distantly related groups of extant archaea that produce methane, which we have named Class I and Class II. Based on this finding, we subsequently investigated the uniqueness of the origin of methanogenesis by studying both the enzymes of methanogenesis and the proteins that synthesize its specific coenzymes. We conclude that hydrogenotrophic methanogenesis appeared only once during evolution. Genes involved in the seven central steps of the methanogenic reduction of carbon dioxide (CO2) are ubiquitous in methanogens and share a common history. This suggests that, although extant methanogens produce methane from various substrates (CO2, formate, acetate, methylated C-1 compounds), these archaea have a core of conserved enzymes that have undergone little evolutionary change. Furthermore, this core of methanogenesis enzymes seems to originate (as a whole) from the last ancestor of all methanogens and does not appear to have been horizontally transmitted to other organisms or between members of Class I and Class II. The observation of a unique and ancestral form of methanogenesis suggests that it was preserved in two independent lineages, with some instances of specialization or added metabolic flexibility. It was likely lost in the Halobacteriales, Thermoplasmatales and Archaeoglobales. Given that fossil evidence for methanogenesis dates back 2.8 billion years, a unique origin of this process makes the methanogenic archaea a very ancient taxon
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