Experimental assesment of Zika virus mechanical transmission by Aedes aegypti

International audienc

Vector competence of Aedes aegypti from Havana, Cuba, for dengue virus type 1, chikungunya, and Zika viruses

Background Like many countries from the Americas, Cuba is threatened by Aedes aegypti-associated arboviruses such as dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. Curiously, when CHIKV was actively circulating in the region in 2013–2014, no autochthonous transmission of this virus was detected in Havana, Cuba, despite the importation of chikungunya cases into this city. To investigate if the transmission ability of local mosquito populations could explain this epidemiological scenario, we evaluated for the first time the vector competence of two Ae. aegypti populations (Pasteur and Párraga) collected from Havana for dengue virus type 1 (DENV-1), CHIKV, and ZIKV. Methodology/Principal findings Mosquito populations were fed separately using blood containing ZIKV, DENV-1, or CHIKV. Infection, dissemination, and transmission rates, were estimated at 3 (exclusively for CHIKV), 7, and 14 days post exposure (dpe) for each Ae. aegypti population-virus combination. Both mosquito populations were susceptible to DENV-1 and ZIKV, with viral infection and dissemination rates ranging from 24–97% and 6–67% respectively. In addition, CHIKV disseminated in both populations and was subsequently transmitted. Transmission rates were low (&lt;30%) regardless of the mosquito population/virus combination and no ZIKV was detected in saliva of females from the Pasteur population at any dpe. Conclusions/Significance Our study demonstrated the ability of Ae. aegypti from Cuba to transmit DENV, ZIKV, and CHIKV. These results, along with the widespread distribution and high abundance of this species in the urban settings throughout the island, highlight the importance of Ae. aegypti control and arbovirus surveillance to prevent future outbreaks. </jats:sec

Elevated carbon dioxide concentration reduces alarm signaling in aphids

Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels

Assessment of pyrochemical processes at CEA: Objectives and current results

International audienceA RandD program has been launched in 1999 to assess the potentialities of the pyrochemical processes which could be an advantageous alternative to hydrometallurgy for two applications: (i) the reprocessing of targets as well as dedicated fuels for minor actinides transmutation if multiple recycling is necessary, (ii) the reprocessing of future nuclear fuels where all the actinides will have to be recycled together (long-term strategies). The period from 1999 to 2005 is mainly devoted to laboratory-scale research (investigations on actinide chemistry in molten halides and liquid metals, exploratory experiments on various separation techniques for actinide recovery)

Futuristic back-end of the nuclear fuel cycle with the partitioning of minor actinides

For future back-end of the nuclear fuel cycle, the partitioning of minor actinides: Np, Am and Cm, followed by their transmutation will minimize importantly the radiotoxicity of nuclear glass waste. In this paper, the research done in France and in Europe will be presented: (i) partitioning of Np by modified PUREX process, (ii) partitioning of Am and Cm by the DIAMEX and SANEX hydrometallurgical processes. (c) 2007 Published by Elsevier B.V

Futuristic Back-end of the Nuclear Fuel Cycle with the Partitioning of Minor Actinides

For future back-end of the nuclear fuel cycle, the partitioning of minor actinides: Np, Am and Cm, followed by their transmutation will minimize importantly the radiotoxicity of nuclear glass waste. In this paper, the research done in France and in Europe will be presented: (i) partitioning of Np by modified PUREX process, (ii) partitioning of Am and Cm by the DIAMEX and SANEX hydrometallurgical processes.JRC.E.5-Nuclear chemistr

CEA's R&D on advanced fuel treatment with multi-recycling of plutonium and uranium

International audienceThe full closure of the fuel cycle stems from the progressive deployment of plutonium and uranium multi-recycling using Fast neutron Reactors (FR) associated with advanced fuel treatment/recycling. On the basis of industrial experience with the present closed fuel cycle and taking advantage of past pilot-scale demonstrations of FR fuel treatment in France, RandD is being conducted in the CEA to move forward in the adaptation and optimization of the overall treatment/recycling process. The main RandD subjects concern increased quantities of fissile material in some key steps of the process the head-end, because of a growing need for Pu based fuel treatment capacities (LWR and FR MOx), the separation step, because of higher Pu/U ratio, and the conversion and production stages to fabricate MOx fuels from recycled Pu and U. The different features of wastes from FR assemblies compared to those from LWRs may require significant optimizations considering future industrial deployment. The main RandD program orientations and recent achievements are presented in this paper