Epizootic rabbit enteropathy. Study of early phenomena with fresh inoculum and attempt at inactivation

[EN] Using 180 35-day-old SPF rabbits, this study used the effectiveness of bacitracin as a tool for acquiring more information on the various phases of ERE, in particular during the hours inoculation. Five groups of animals were used, including 3 treatments with Bacivet S(R) (bacitracin) at different times from inoculation, with the standard inoculum TEC3. Three parameters were studied: growth, mortality and stomach noises (borborygmi). A significant fall in growth rate was observed during the first 18 hours following the inoculation in all the inoculated groups, both medicated and not medicated. Treatment with bacitracin eliminated mortality and borborygmi, but not the initial fall in growth rate. Treatment starting 18 hours after inoculation is less effective during the acute phase than the preventive treatment. With a preventive treatment interrupted as soon as 18 hours after inoculation, a delay of several days was observed before the appearance of the disease (fall in growth rate, manifestation of borborygmi) and total mortality was reduced. Very few pathogens can explain this early fall in growth rate. Bacitracin is an antibiotic which offers good control of the disease, and probably of the pathogen but not of the physio-pathological disturbances in the first few hours. The intervention of an exogenic toxin in the first hours of contamination seems likely. Borborygmi are important criteria. The intensity and/or frequency could be used as semi-quantitative criteria to characterize the disease and for the prognosis. In a simultaneous trial, a group was contaminated with the same inoculum, heated for 10 min at 55°C, in order to obtain more information on the type of pathogen involved in the etiology of ERE. This treatment did not modify the virulence of the inoculum.This research received financial help from the Ministry for Agriculture of France (DGAL - ITAVI).Coudert, P.; Licois, D. (2005). Epizootic rabbit enteropathy. Study of early phenomena with fresh inoculum and attempt at inactivation. World Rabbit Science. 13. doi:10.4995/wrs.2005.515SWORD1

Defects and disorder in metal organic frameworks.

The wide-ranging properties of metal organic frameworks (MOFs) rely in many cases on the presence of defects within their structures and the disorder that is inevitably associated with such defects. In the present work we review several aspects of defects in MOFs, ranging from simple substitutional defects at metal cation or ligand positions, to correlated defects on a larger length scale and the extreme case of disorder associated with amorphous MOFs. We consider both porous and dense MOFs, and focus particularly on the way in which defects and disorder can be used to tune physical properties such as gas adsorption, catalysis, photoluminescence, and electronic and mechanical properties.The authors would like to thank Ras Al Khaimah Center for Advanced Materials (AKC, TDB), Trinity Hall (TDB), and the ERC (ALG, Grant 279705).This is the author accepted manuscript. The final version is available from RSC via http://dx.doi.org/10.1039/C5DT04392

Energy saving in fixed wireless broadband networks

International audienceIn this paper, we present a mathematical formulation for saving energy in fixed broadband wireless networks by selectively turning off idle communication devices in low-demand scenarios. This problem relies on a fixed-charge capacitated network design (FCCND), which is very hard to optimize. We then propose heuristic algorithms to produce feasible solutions in a short time.Dans cet article, nous proposons une modélisation en programme linéaire en nombres entiers pour le problème de minimiser la consommation d'énergie dans les réseaux de collecte à faisceaux hertziens en éteignant une partie des équipements lorsque le trafic est bas. Ce problème repose sur un problème de dimensionnement de réseaux dont les arcs ont une capacité fixe, qui est très difficile à résoudre. Nous proposons un algorithme heuristique fournissant rapidement des solutions réalisables

Modeling the microclimate inside a vessel in in vitro culture : vessel with agar

Numerical simulations show that variations in vessel internal humidity was sensitive to transfer coefficient, climatic conditions within the growth chamber, evaporation and condensation of water vapor on the walls of the vessel. The variations in water vapor pressure deficits (VPD) (low during the nyctiperiod and high during the photoperiod) were well explained by a free convection model, which took into account temperature differences. Finally, the results show the necessity to construct containers with variable openings and growth chambers in which bioclimatic conditions can be controlled.Les simulations numériques révèlent que les variations de l\'humidité interne ont été sensibles au coefficient d\'échange de vapeur d\'eau, aux conditions climatiques de la chambre de culture et aux phénomènes d\'évaporation et de condensation de vapeur d\'eau sur les parois des bocaux. Par ailleurs, il a été établi que le «créneau» de déficit de pression de vapeur (DPV) de l\'air intérieur (palier de DPV faible en nyctipériode et palier de DPV élevé en photopériode) a été bien imité en mode convectif libre qui tient compte des écarts de températures. Ainsi, ces résultats montrent la nécessité de construire des récipients à ouverture variable et des chambres de culture dans lesquelles les facteurs bioclimatiques des plantes peuvent être maîtrisés. Keywords: Agar, in vitro culture, microclimate, modeling, transfer coefficient./Agar, culture in vitro, microclimat, modélisation, coefficient d\'échange.Sciences & Nature Vol. 4 (1) 2007: pp. 75-8

Production/maintenance cooperative scheduling using multi-agents and fuzzy logic

Within companies, production is directly concerned with the manufacturing schedule, but other services like sales, maintenance, purchasing or workforce management should also have an influence on this schedule. These services often have together a hierarchical relationship, i.e. the leading function (most of the time sales or production) generates constraints defining the framework within which the other functions have to satisfy their own objectives. We show how the multi-agent paradigm, often used in scheduling for its ability to distribute decision-making, can also provide a framework for making several functions cooperate in the schedule performance. Production and maintenance have been chosen as an example: having common resources (the machines), their activities are actually often conflicting. We show how to use a fuzzy logic in order to model the temporal degrees of freedom of the two functions, and show that this approach may allow one to obtain a schedule that provides a better compromise between the satisfaction of the respective objectives of the two functions

Notions of Connectivity in Overlay Networks

International audience" How well connected is the network? " This is one of the most fundamental questions one would ask when facing the challenge of designing a communication network. Three major notions of connectivity have been considered in the literature, but in the context of traditional (single-layer) networks, they turn out to be equivalent. This paper introduces a model for studying the three notions of connectivity in multi-layer networks. Using this model, it is easy to demonstrate that in multi-layer networks the three notions may differ dramatically. Unfortunately, in contrast to the single-layer case, where the values of the three connectivity notions can be computed efficiently, it has been recently shown in the context of WDM networks (results that can be easily translated to our model) that the values of two of these notions of connectivity are hard to compute or even approximate in multi-layer networks. The current paper shed some positive light into the multi-layer connectivity topic: we show that the value of the third connectivity notion can be computed in polynomial time and develop an approximation for the construction of well connected overlay networks

Can Thermoclines Be a Cue to Prey Distribution for Marine Top Predators? A Case Study with Little Penguins

The use of top predators as bio-platforms is a modern approach to understanding how physical changes in the environment may influence their foraging success. This study examined if the presence of thermoclines could be a reliable signal of resource availability for a marine top predator, the little penguin (Eudyptula minor). We studied weekly foraging activity of 43 breeding individual penguins equipped with accelerometers. These loggers also recorded water temperature, which we used to detect changes in thermal characteristics of their foraging zone over 5 weeks during the penguin’s guard phase. Data showed the thermocline was detected in the first 3 weeks of the study, which coincided with higher foraging efficiency. When a thermocline was not detected in the last two weeks, foraging efficiency decreased as well. We suggest that thermoclines can represent temporary markers of enhanced food availability for this top-predator to which they must optimally adjust their breeding cycle