High-Level Behavior Regulation for Multi-Robot Systems

International audienceWe propose a new collaborative guidance platform for a team of robots that should protect a fixed ground target from one or several threats. The team of robots performs high-level behaviors. These are hand-coded since they consist in driving the robots to some given position. However, deciding when and how to use these behaviors is much more challenging. Scripting high-level interception strategies is a complex problem and applicable to few specific application contexts. We propose to use a gene regulatory network to regulate high-level behaviors and to enable the emergence of efficient and robust interception strategies

The macrofilaricidal efficacy of repeated doses of ivermectin for the treatment of river blindness

Background: Mass drug administration (MDA) with ivermectin is the cornerstone of efforts to eliminate human onchocerciasis by 2020 or 2025. The feasibility of elimination crucially depends on the effects of multiple ivermectin doses on Onchocerca volvulus. A single ivermectin (standard) dose clears the skin-dwelling microfilarial progeny of adult worms (macrofilariae) and temporarily impedes the release of such progeny by female macrofilariae, but a macrofilaricidal effect has been deemed minimal. Multiple doses of ivermectin may cumulatively and permanently reduce the fertility and shorten the lifespan of adult females. However, rigorous quantification of these effects necessitates interrogating longitudinal data on macrofilariae with suitably powerful analytical techniques. Methods: Using a novel mathematical modeling approach, we analyzed, at an individual participant level, longitudinal data on viability and fertility of female worms from the single most comprehensive multiple-dose clinical trial of ivermectin, comparing 3-monthly with annual treatments administered for 3 years in Cameroon

Hubble Space Telescope Grism Spectroscopy of Extreme Starbursts Across Cosmic Time: The Role of Dwarf Galaxies in the Star Formation History of the Universe

Near infrared slitless spectroscopy with the Wide Field Camera 3, onboard the Hubble Space Telescope, offers a unique opportunity to study low-mass galaxy populations at high-redshift ($z\sim$1-2). While most high$-z$ surveys are biased towards massive galaxies, we are able to select sources via their emission lines that have very-faint continua. We investigate the star formation rate (SFR)-stellar mass ($M_{\star}$) relation for about 1000 emission-line galaxies identified over a wide redshift range of $0.3 \lesssim z \lesssim 2.3$. We use the H$_{\alpha}$ emission as an accurate SFR indicator and correct the broadband photometry for the strong nebular contribution to derive accurate stellar masses down to $M_{\star} \sim 10^{7} M_{\odot}$. We focus here on a subsample of galaxies that show extremely strong emission lines (EELGs) with rest-frame equivalent widths ranging from 200 to 1500 \AA. This population consists of outliers to the normal SFR-$M_{\star}$ sequence with much higher specific SFRs ($> 10$ Gyr$^{-1}$). While on-sequence galaxies follow a continuous star formation process, EELGs are thought to be caught during an extreme burst of star formation that can double their stellar mass in less than $100$ Myr. The contribution of starbursts to the total star formation density appears to be larger than what has been reported for more massive galaxies in previous studies. In the complete mass range $8.2 <$ log($M_{\star}/M_{\odot}$) $< 10$ and a SFR lower completeness limit of about 2 $M_{\odot}$ yr$^{-1}$ (10 $M_{\odot}$ yr$^{-1}$) at $z\sim1$ ($z \sim 2$), we find that starbursts having EW$_{rest}$(H$_{\alpha}$)$>$ 300, 200, and 100 A contribute up to $\sim13$, 18, and 34 %, respectively, to the total SFR of emission-line selected sample at $z\sim1-2$. The comparison with samples of massive galaxies shows an increase in the contribution of starbursts towards lower masses.Comment: 11 pages, 6 figures. The Astrophysical Journal, in pres

Guidelines for the design, conduct and reporting of human intervention studies to evaluate the health benefits of foods

There is substantial evidence to link what we eat to the reduction of the risk of major chronic diseases and/or the improvement of functions. Thus, it is important for public health agencies and the food industry to facilitate the consumption of foods with particular health benefits by providing consumer products and messages based on scientific evidence. Although fragmentary advice is available from a range of sources, there is a lack of comprehensive scientific guidelines for the design, conduct and reporting of human intervention studies to evaluate the health benefits of foods. Such guidelines are needed both to support nutrition science in general, and to facilitate the substantiation of health claims. In the present study, which presents the consensus view of an International Life Sciences Institute Europe Expert Group that included senior scientists from academia and industry, the term †foods’ refers to foods, dietary supplements and food constituents, but not to whole diets. The present study is based on an initial survey of published papers, which identified the range and strengths and weaknesses of current methodologies, and was finalised following exchanges between representatives from industry, academia and regulatory bodies. The major factors involved in the design, conduct and reporting of studies are identified, summarised in a checklist table that is based on the Consolidated Standards of Reporting Trials guidelines, and elaborated and discussed in the text. © 2011 ILSI Europe

An evaluation of SMOS L-band vegetation optical depth (L-VOD) data sets:high sensitivity of L-VOD to above-ground biomass in Africa

The vegetation optical depth (VOD) measured at microwave frequencies is related to the vegetation water content and provides information complementary to visible/infrared vegetation indices. This study is devoted to the characterization of a new VOD data set obtained from SMOS (Soil Moisture and Ocean Salinity) satellite observations at L-band (1.4 GHz). Three different SMOS L-band VOD (LVOD) data sets (SMOS level 2, level 3 and SMOS-IC) were compared with data sets on tree height, visible/infrared indexes (NDVI, EVI), mean annual precipitation and above-ground biomass (AGB) for the African continent. For all relationships, SMOS-IC showed the lowest dispersion and highest correlation. Overall, we found a strong (R > 0.85) correlation with no clear sign of saturation between L-VOD and four AGB data sets. The relationships between L-VOD and the AGB data sets were linear per land cover class but with a changing slope depending on the class type, which makes it a global non-linear relationship. In contrast, the relationship linking L-VOD to tree height (R = 0.87) was close to linear. For vegetation classes other than evergreen broadleaf forest, the annual mean of L-VOD spans a range from 0 to 0.7 and it is linearly correlated with the average annual precipitation. SMOS L-VOD showed higher sensitivity to AGB compared to NDVI and K/X/C-VOD (VOD measured at 19, 10.7 and 6.9 GHz). The results showed that, although the spatial resolution of L-VOD is coarse (similar to 40 km), the high temporal frequency and sensitivity to AGB makes SMOS L-VOD a very promising indicator for large-scale monitoring of the vegetation status, in particular biomass

Resolving debris discs in the far-infrared: early highlights from the DEBRIS survey

We present results from the earliest observations of DEBRIS, a Herschel Key Programme to conduct a volume- and flux-limited survey for debris discs in A-type through M-type stars. PACS images (from chop/nod or scan-mode observations) at 100 and 160 micron are presented toward two A-type stars and one F-type star: beta Leo, beta UMa and eta Corvi. All three stars are known disc hosts. Herschel spatially resolves the dust emission around all three stars (marginally, in the case of beta UMa), providing new information about discs as close as 11 pc with sizes comparable to that of the Solar System. We have combined these data with existing flux density measurements of the discs to refine the SEDs and derive estimates of the fractional luminosities, temperatures and radii of the discs.Comment: to be published in A&A, 5 pages, 2 color figure

COST-G: towards a new GRACE and GRACE-FO combination

The combination service for time-variable gravity fields (COST-G) provides the full time-series of monthly GRACE gravity fields: COST-G GRACE RL01, combined in reprocessing mode, and a steadily growing time-series of monthly GRACE-FO gravity fields: COST-G GRACE-FO RL01 OP, combined on an operational basis. Both time-series are currently considered for re-combination. In case of GRACE, new high-quality time-series from Chinese analysis centers are available for combination. In case of GRACE-FO, a revision of the weighting scheme, developed in the frame of the Horizon2020 project Global Gravity-based Groundwater Product (G3P), and the availability of reprocessed GRACE-FO time-series from AIUB, CSR, GFZ, and JPL, lead to a significant improvement of the combined gravity fields. We present the preliminary re-combined GRACE and GRACE-FO time-series and quantify the differences with respect to the COST-G RL01 series in terms of signal and noise content