Improved rates for Wasserstein deconvolution with ordinary smooth error in dimension one

This paper deals with the estimation of a probability measure on the real line from data observed with an additive noise. We are interested in rates of convergence for the Wasserstein metric of order $p\geq 1$. The distribution of the errors is assumed to be known and to belong to a class of supersmooth or ordinary smooth distributions. We obtain in the univariate situation an improved upper bound in the ordinary smooth case and less restrictive conditions for the existing bound in the supersmooth one. In the ordinary smooth case, a lower bound is also provided, and numerical experiments illustrating the rates of convergence are presented

A geometric study of Wasserstein spaces: Hadamard spaces

Optimal transport enables one to construct a metric on the set of (sufficiently small at infinity) probability measures on any (not too wild) metric space X, called its Wasserstein space W(X). In this paper we investigate the geometry of W(X) when X is a Hadamard space, by which we mean that $X$ has globally non-positive sectional curvature and is locally compact. Although it is known that -except in the case of the line- W(X) is not non-positively curved, our results show that W(X) have large-scale properties reminiscent of that of X. In particular we define a geodesic boundary for W(X) that enables us to prove a non-embeddablity result: if X has the visibility property, then the Euclidean plane does not admit any isometric embedding in W(X).Comment: This second version contains only the first part of the preceeding one. The visibility properties of W(X) and the isometric rigidity have been split off to other articles after a referee's commen

Lead-induced DNA damage in Vicia faba root cells: Potential involvement of oxidative stress

Genotoxic effects of lead (0–20 µM) were investigated in whole-plant roots of Vicia faba L., grown hydroponically under controlled conditions. Lead-induced DNA damage in V. faba roots was evaluated by use of the comet assay, which allowed the detection of DNA strand-breakage and with the V. faba micronucleus test, which revealed chromosome aberrations. The results clearly indicate that lead induced DNA fragmentation in a dose-dependant manner with a maximum effect at 10 µM. In addition, at this concentration, DNA damage time-dependently increased until 12 h. Then, a decrease in DNA damages was recorded. The significant induction of micronucleus formation also reinforced the genotoxic character of this metal. Direct interaction of lead with DNA was also evaluated with the a-cellular comet assay. The data showed that DNA breakages were not associated with a direct effect of lead on DNA. In order to investigate the relationship between lead genotoxicity and oxidative stress, V. faba were exposed to lead in the presence or absence of the antioxidant Vitamin E, or the NADPH-oxidase inhibitor dephenylene iodonium (DPI). The total inhibition of the genotoxic effects of lead (DNA breakage and micronucleus formation) by these compounds reveals the major role of reactive oxygen species (ROS) in the genotoxicity of lead. These results highlight, for the first time in vivo and in whole-plant roots, the relationship between ROS, DNA strand-breaks and chromosome aberrations induced by lead

A geometric study of Wasserstein spaces: an addendum on the boundary

International audienceWe extend the geometric study of the Wasserstein space W(X) of a simply connected, negatively curved metric space X by investigating which pairs of boundary points can be linked by a geodesic, when X is a tree

ONG, social entreprises et social business : le cas du Cambodge

http://riuess2014.sciencesconf.org/30871"Au Cambodge, les organisations privées revendiquant des pratiques et missions d'utilité sociale sont des ONG, entreprises sociales et social businesses. Ce texte vise à clarifier les relations entretenues entre ces trois organisations qui, dans les faits, se recoupent pour une bonne part, ainsi que leurs pratiques et la justification de leur mission sociale. Il présente les spécificités du contexte cambodgien, puis discute le contenu supposé des termes et la diversité, voire le flou, qui les caractérise. Sur ces bases, l'étude de quelques-unes de ces organisations conduit à identifier plusieurs contenus de la mission sociale revendiquée : respecter le droit du travail, prêter attention aux employés, améliorer leur situation et leur pouvoir d'agir par le travail ou par la consommation. Deux questions transversales traversent ces expériences : l'objectif d'autonomie financière et une réflexion sur le rôle du profit.".http://riuess2014.sciencesconf.org/3087

Optimisation of cultural practices for organic potato: effect of irrigation regimes on the development of late blight, crop yield and quality

A trial was established in 2003, in Southern France, to assess under organic farming conditions the effect of top irrigation with sprinklers on potato yield, but also to evaluate side effects on epidemics, with a focus on late blight (Phytophthora infestans L.). Two varieties, one susceptible (Charlotte) and one with a good level of resistance to late blight (Eden), have been planted. Three irrigation regimes have been applied : no irrigation [NO], reduced or optimized irrigation [OPT] and irrigation according to usual grower practice [NORM]. Irrigation had no effect on foliar late blight development. For both varieties, commercial yield in the non-irrigated plots was significantly lower (16,36 t.ha-1) than in the OPT and NORM plots (resp. 26,12 t.ha-1 and 24,15 t.ha-1), with a higher proportion of small tubers for NO (11,96%) than for OPT and NORM (resp. 4,25% and 3,32%). Irrigation regime had no effect on proportion of tubers with affected by either late blight or Rhizoctonia (black scurf). As expected, Charlotte confirmed its susceptibility to foliar late blight, while Eden had a significant higher total yield than Charlotte (resp. 47,19 t.ha-1 and 32,19 t.ha-1). However, there was no significant difference between the two varieties for commercial yield (resp. 20,51 t.ha-1 and 23,91 t.ha-1), due to a large proportion of tubers with black scurf and of mis-shaped tubers in Eden. For conclusion, irrigation in this region is necessary to obtain reasonable yields and tuber sizes compatible with market requirements. It is possible to reduce irrigation doses without reducing significantly yields, in order to preserve water resources. Under the conditions of this trial, top irrigation on foliage did not increase late blight or silver scurf severity