Scientific Rationale of Saturn's In Situ Exploration

Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustratedby the exploration of Jupiter, where key measurements such as the determination of the noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scienti-c goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussedthroughout this paper : rst, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk elemental and isotopiccomposition would place important constraints on the volatile reservoirs in the protosolar nebula. We also show that the in situ measurement of CO (or any other disequilibrium species that is depleted by reaction with water) in Saturn's upper troposphere may help constraining its bulk OH ratio. We compare predictions of Jupiter and Saturn's bulk compositions from different formation scenarios, and highlight the key measurements required to distinguish competing theories to shed light on giant planet formation as a common process in planetary systems with potential applications to mostextrasolar systems. In situ measurements of Saturn's stratospheric and tropospheric dynamics, chemistry and cloud-forming processes will provide access to phenomena unreachable to remote sensing studies. Dierent mission architectures are envisaged, which would benet from strong international collaborations, all based on an entry probe that would descend through Saturn's stratosphere and troposphere under parachute down to a minimum of 10 bars of atmospheric pressure. We rally discuss the science payload required on a Saturn probe to match the measurement requirements

Malaria vector research and control in Haiti: a systematic review

BACKGROUND: Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS: A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS: A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000–2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION: Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination

European surveillance of antimicrobial consumption (ESAC) : systemic antiviral use in Europe

Objectives: To assess the total systemic antiviral use in Europe and to identify the antiviral substances most commonly used.Methods: Within the European Surveillance of Antimicrobial Consumption (ESAC; www.esac.ua.ac.be), using the anatomical therapeutic chemical (ATC) classification and defined daily dose (DDD) measurement unit, data on total (out- and inpatient) systemic antiviral use (ATC J05), aggregated at the level of the active substance, were collected for 2008, and use was expressed in DDD (WHO ATC/DDD, version 2010) per 1000 inhabitants per day (DID). Antiviral substances were grouped according to their main indication.Results: In Europe, 12 countries (Belgium, Croatia, Denmark, Estonia, Finland, France, Hungary, Italy, Luxembourg, Russia, Slovenia and Sweden) provided total (out- and inpatient) data and 4 countries (Austria, the Netherlands, Portugal and Norway) provided outpatient data only. Total systemic antiviral use varied by a factor of 10.95 between the country with the highest (3.53 DID in France) and the country with the lowest (0.32 DID in Croatia) use. HIV/AIDS antivirals represented more than 50% of the total antiviral use in most countries. The amount and spectrum of antivirals used varied greatly between countries.Conclusions: Our study demonstrated a wide variation of total systemic antiviral use in several European countries, as striking as that of outpatient systemic antibiotic, antimycotic and antifungal use. The variation is mainly determined by the use of HIV/AIDS antivirals. These observations should stimulate further analysis to understand the variation of specific antiviral substances. The ESAC data facilitate auditing of antiviral prescriptions and evaluation of the implementation of guidelines and public health policies.peer-reviewe

Comparative genotoxicity of aluminium and cadmium in embryonic zebrafish cells

International audienceAluminium is a toxic metal whose genotoxicity has been scarcely studied in aquatic species and more generally in mammals. Recently, human and ecological disaster caused by the discharge of red mud in Hungary has revived questions about the toxicity of this metal particularly for the environment. On the contrary, cadmium is a highly toxic metal whose genotoxicity has been well characterized in various mammalian cells. However on non-human cells, little is known about its impact on DNA damage and repair.In this study, the genotoxic potential of both metals on embryonic zebrafish cells ZF4 was analyzed and particularly the impairment of the major DNA double strand breaks (DSB)-repair pathway, i.e. non-homologous end-joining (NHEJ).To this aim, DNA single strand breaks (SSB) and DSB were evaluated using the comet assay and the immunodetection of γ-H2AX proteins, respectively, in AlCl3 or CdCl2 exposed ZF4 cells. These exposures result in the production of DSBs a few hours after incubation. The DNA-PK kinase activity, essential for NHEJ, is more affected by the presence of aluminium than cadmium. Altogether our data provide evidence of the high toxicity induced by aluminium in zebrafish and indicates the pertinence of genotoxicity evaluation in organisms living in contaminated water. © 2012 Elsevier B.V

Surface functionalization of plasticized chitosan films through PNIPAM grafting via UV and plasma graft polymerization

International audienceChitosan films were formulated and subsequently given thermosensitive properties by modifying the surfaces. The first step involved the incorporation of poly(ethylene glycol) (PEG) plasticizers at various ratios into the chitosan blends. Tensile tests showed that the molecular weight of the PEG impacted the mechanical properties, while the plasticizing effect was optimal for a PEG content of 20%. The addition of glycerol, in combination with PEG, increased the elongation at break without altering the tensile strength. In order to add thermosensitive properties to the chitosan films, poly(N-isopropylacrylamide) (PNIPAM) was graft polymerized on the surface via two methods: UV irradiation or plasma treatment. The surface modification was evaluated in terms of surface characteristics (XPS, SEM, contact angle) and bulk swelling abilities, with a specific focus on the thermosensitive nature due to the lower critical solution temperature (LCST) transition of the PNIPAM. The two grafting methods implied differences in terms of thermal responsiveness. Indeed, due to the presence of particles on their surfaces, UV grafted samples exhibited higher hydrophilicity and thermosensitivity, whereas their lower content of PNIPAM involved lower swelling thermal dependence. All of these results support the interest in PNIPAM grafted chitosan surfaces for the development of smart biomaterials

How toxic is the depleted uranium to crayfish Procambarus clarkii compared with cadmium?

International audienceDue to a lack of information on the assessment of uranium's (U) toxicity, our work aimed to compare the effects of U on the crayfish Procambarus clarkii with those of the well documented metal cadmium (Cd). Accumulation and impacts at different levels of biological organization were assessed after acute (40 μM Cd or U; 4-10 days) and chronic (0.1 μM Cd or U; 30-60 days) exposures. The survival rates demonstrated the high tolerance of this species toward both metals and showed that Cd had a greater effect on the sustainability of crayfish. The concentration levels of Cd and U accumulated in gills and hepatopancreas were compared between both conditions. Distinctions in the adsorption capacities and the mobility of the contaminants were suspected. Differences in the detoxification mechanisms of both metals using transmission electron microscopy equiped with an energy dispersive X-ray were also pointed out. In contrast, comparison between the histological structures of contaminated hepatopancreas showed similar symptoms. Principal component analyses revealed different impacts of each metal on the oxidative balance and mitochondria using enzymatic activities and gene expression levels as endpoints. The observation that U seemed to generate more oxidative stress than Cd in our conditions of exposure is discussed. © 2014 Wiley Periodicals, Inc

Hybrid electronic-photonic subwavelength cavities operating at terahertz frequencies

International audienc

Mitochondrial gene expression, antioxidant responses, and histopathology after cadmium exposure

International audienceThe present study investigates cadmium effects on the transcription of mitochondrial genes of Procambarus clarkii after acute (0.05, 0.5, and 5 mg Cd/L; 4-10 days) and chronic exposures (10 μg Cd/L; 30-60 days). Transcriptional responses of cox1, atp6, and 12S using quantitative real-time RT-PCR were assessed in gills and hepatopancreas. Additionally, the expression levels of genes involved in detoxification and/or oxidative stress responses [mt, sod(Mn)] and enzymatic activities of antioxidants (SOD, CAT, GPX, and GST) were analyzed. The histopathological effects in hepatopancreas of crayfish were evaluated by light microscopy. Relationships between endpoints at different levels of biological organization and Cd bioaccumulation were also examined. Cd induced high levels of bioaccumulation, which was followed by mitochondrial dysfunction and histological alterations in both experiments. Moreover, perturbations in the defence mechanisms against oxidative stress tended to increase with time. Results also showed that molecular responses can vary depending on the intensity and duration of the chemical stress applied to the organisms and that the study of mt gene expression levels seemed to be the best tool to assess Cd intoxication. © 2012 Wiley Periodicals, Inc., a Wiley company