Human antibody responses to the Anopheles salivary gSG6-P1 peptide: a novel tool for evaluating the efficacy of ITNs in malaria vector control.

International audienceTo optimize malaria control, WHO has prioritised the need for new indicators to evaluate the efficacy of malaria vector control strategies. The gSG6-P1 peptide from gSG6 protein of Anopheles gambiae salivary glands was previously designed as a specific salivary sequence of malaria vector species. It was shown that the quantification of human antibody (Ab) responses to Anopheles salivary proteins in general and especially to the gSG6-P1 peptide was a pertinent biomarker of human exposure to Anopheles. The present objective was to validate this indicator in the evaluation of the efficacy of Insecticide Treated Nets (ITNs). A longitudinal evaluation, including parasitological, entomological and immunological assessments, was conducted on children and adults from a malaria-endemic area before and after the introduction of ITNs. Significant decrease of anti-gSG6-P1 IgG response was observed just after the efficient ITNs use. Interestingly, specific IgG Ab level was especially pertinent to evaluate a short-time period of ITNs efficacy and at individual level. However, specific IgG rose back up within four months as correct ITN use waned. IgG responses to one salivary peptide could constitute a reliable biomarker for the evaluation of ITN efficacy, at short- and long-term use, and provide a valuable tool in malaria vector control based on a real measurement of human-vector contact

Performance of the Gamma-ray Cherenkov Telescope structure: a dual-mirror telescope prototype proposed for the future Cherenkov Telescope Array

International audienceThe Cherenkov Telescope Array (CTA) project aims to create the next generation Very High-Energy (VHE) gamma-ray telescope array. It will be devoted to the observation of gamma rays from 20 GeV to above 100 TeV. Because of this wide energy band, three classes of telescopes, associated with different energy ranges and different mirror sizes, are defined. The Small Size Telescopes (SSTs) are associated with the highest energy range. Seventy of these telescopes are foreseen on the Southern site of the CTA. The large number of telescopes constrains their mechanical structure because easy maintenance and reduced cost per telescope are needed. Moreover, of course, the design shall fulfill the required performance and lifetime in the environment conditions of the site. The Observatoire de Paris started design studies in 2011 of the mechanical structure of the GCT (Gamma-ray Cherenkov Telescope), a four-meter prototype telescope for the SSTs of CTA, from optical and preliminary mechanical designs made by the University of Durham. At the end of 2014 these studies finally resulted in a lightweight ( 8 tons) and stiff design. This structure was based on the dual-mirror Schwarzschild-Couder (SC) optical design, which is an interesting and innovative alternative to the one-mirror Davies-Cotton design commonly used in ground-based Cherenkov astronomy. The benefits of such a design are many since it enables a compact structure, lightweight camera and a good angular resolution across the entire field-of-view. The mechanical structure was assembled on the Meudon site of the Observatoire de Paris in spring 2015. The secondary mirror, panels of the primary mirror and the Telescope Control System were successfully implemented afterwards leading now to a fully operational telescope. This paper focuses on the mechanics of the telescope prototype. It describes the mechanical structure and presents its performance identified from computations or direct measurements. Upgrades of the design in the context of the preproduction and the large scale CTA production are also discussed

Serum Detection of Nonadherence to Adjuvant Tamoxifen and Breast Cancer Recurrence Risk

International audienc

IgG Ab responses to gSG6-P1 before and after ITN use.

<p>The percentage (%) of anti-gSG6-P1 IgG immune responders (thick-dotted line) in the “immunological” sub-population (n = 105), before (2005) and after (2006 and January 2007) the installation of ITNs (A). These results are presented together with the intensity of <i>P. falciparum</i> infection (mean parasitaemia – fine-dotted line) measured in the same population and the mean of number of <i>An. gambiae</i> (solid line) in the studied area (A). Entomological data (number of <i>An. gambiae</i>) were not available in December 2006 and January 2007 (the two last months of the study). This arrow indicates the installation of Insecticide Treated Nets (ITNs) in February 2006. Individual anti-gSG6-P1 IgG levels (ΔOD) are presented before (2005) and after (2006) the installation of ITNs (B). Bars indicate the median value for each studied month. Statistically significant differences between months are indicated.</p

IgG response to gSG6-P1 as biomarker for short-term ITN efficacy.

<p>Changes in individual IgG levels (ΔOD) are presented between “just before” (January 2006) and “just after” (April 2006) ITN introduction (n = 105; children and adults) (A). The arrow indicates the installation of Insecticide Treated Nets (ITNs) in February 2006. Individual IgG level changes from January (before) to April are presented (B) by individual ΔOD_ITNs, value (ΔOD_ITNs =ΔOD_April06, - ΔOD_January06). The threshold of specific IgG responders (TR = 0.204) is indicated (dotted line). Significant positive (ΔOD>0.204) or negative (ΔOD<−0.204) changes are therefore individually presented.</p

Changes in anti-gSG6-P1 IgG levels before and after the introduction of ITNs according to age group.

<p>Median anti-gSG6-P1 IgG levels in 2005–2006 are presented according to three age groups (A): 0–6 years-old (solid line; n = 49), 7–14 years-old (thick-dotted line; n = 34) and >14 years-old (fine-dotted line; n = 25). Individual, short-term changes in specific IgG levels from January (just before) to April (just after ITN installation), are presented according to age group (0–6 years = B; 7–14 years = C and >14 years = D). The arrow indicates the installation of Insecticide Treated Nets (ITNs) in February 2006. Statistically significant differences between age groups are indicated for respective months (*: P<0.05; ***: P<0.0001).</p

Gas-Chromatographic analysis of Mars soil samples with the SAM instrument onboard Curiosity - the 180 first sols

International audienceAmongst the SAM suite of instruments [1], SAM-GC (Gas Chromatograph) is devoted to identify and quantify volatiles evolved from the thermal/chemical treatment of any soil sample collected by the Curiosity rover. The first soil samples analyzed with SAM were composed of sand collected at the Rocknest site, when the second site analyzed was a basin called "Yellowkive Bay". For their analysis, these samples were submitted to a pyrolysis at temperatures reaching about 900°C. For SAM-GC and GCMS analyses, different fractions of pyrolysates were collected at different temperature in the ambient-900°C range in order to discriminate potential different volatile fractions present in the solid sample.With the aim to search for potential organic molecules outgassed from the samples, a SAM-GC analytical channel composed of thermal-desorption injector and a MXT-CLP chromatographic column was used as it was designed for the separation of a wide range of volatile organic molecules. This channel is also equipped with a thermal conductivity detector (TCD) capable to detect the most abundant species (with abundances down to approximately 10-10 mol). It is thus complementary to the mass spectrometer detection for quantification of such species as this last instrument has not a linear response in this domain of high abundance, whereas it is significantly more sensitive than the TCD. The results obtained with this instrument first show that the performances of SAM-GC are representative of those obtained during calibrations of the instrument in laboratory, as well as they are repeatable. Hence, the instrument performs nominally, making it the first GCMS running successfully on Mars since the Viking missions. Moreover, the complementarity of GC towards MS is also shown, either by allowing the quantification ofthe major species detected (as water), or by providing a chromatographic signal well resolved temporally which can be used to improve the QMS signal treatment.In the frame of research of organics, the SAM-GC analyses contribute to the identification of several methyl-chlorohydrocarbons, and of HCN in the gases evolved from the solid sample. These detections strongly support the presence of perchlorates in the Rocknest soil. Since perchlorates have been detected with Phoenix lander [2] and then recently with Curiosity, the re-interpretation of the Viking data have to be seen under a new angle [3]. The nondetection of PAHs is also interesting to notice, when it is known that micrometeorites containing PAHs still bring this organic material to the Mars surface today. This lack of detection defines an upper limit on the content of PAHs in the martian soil at the sites studied by Curiosity, but it could also be indicative of the presence of chemical mechanisms that process this type of material at the surface