Abdominal sensory equipment involved in external host discrimination in a solitary parasitoid wasp

Already parasitized hosts are often of poorer quality than healthy hosts. It is therefore usually advantageous for parasitoid females to recognize and reject them. Parasitized hosts can be identified on the basis of various physical or chemical marks present on the surface or inside the hosts or their surroundings in the case of concealed host. Here we studied host discrimination behaviors of females of a certain population of Pachycrepoideus vindemmiae, a solitary ectoparasitoid, which are known to reject large-sized parasitized hosts after an abdominal examination of their surface. We first investigated females' recognition behaviors of host parasitism status when confronted to small-sized hosts (Drosophila melanogaster pupae) as host size may influence the use of different cues for host selection. We showed that, in such a situation, females also discriminate parasitized hosts after an external host exploration with the tip of their ovipositor sheath (third valvulae). We then described the sense organs present on the different parts of the ovipositor by means of scanning and transmission electron microscopy analysis. As the extremity of the third valvulae bears only one type of sensilla that appears to be chemoreceptors, we considered these sensilla as highly likely to be involved in host discrimination in P. vindemmiae. To our knowledge, this is the first time that receptors located on the ovipositor sheath are described as implicated in host discrimination in parasitoid wasps. We discuss potential chemical markers that might be detected by these receptors.     

Further new CW FIR lasting investigations in CH3I,13CH3I and CD3I: New lines and assignments

Forty seven new CW FIR emissions lines have been observed in CH₃I,¹³CH₃I and CD₃I, optically pumped by a CO₂ laser and a N₂ laser, in a metallic waveguide resonator. Assignments are given for a large number of these new lines.     

Far-infrared laser action in vinyl chloride,vinyl bromide,and vinyl fluoride optically pumped by a CW N2O laser

This paper reports the first use of a N₂O laser for optically pumping vinyl halides, to obtain new cw submillimeter laser lines. Eighteen far-infrared (FIR) emissions have been observed in vinyl chloride, twenty five in vinyl bromide and thirty eight in vinyl flouride.     

Pig I alpha I appears unmodified in plasma in case of endotoxin-induced disseminated intravascular coagulation

The unrestricted activity of leukocyte proteinases is thought to contribute to the degradation of plasma proteins and thus amplify the coagulation disorders occurring in septic shock. Inter-alpha-inhibitor (I alpha I) is a plasma protein particularly susceptible to their action. Therefore we investigated its behavior in a porcine model of endotoxin shock which reproduces the coagulation changes observed in human sepsis. We did not detect any qualitative or quantitative modification of porcine I alpha I in plasmas collected from pigs after endotoxin infusion. To explain these data, I alpha I was incubated with polymorphonuclear neutrophils (PMN) stimulated by FMLP in the presence of cytochalasin B. We found that, unlike human PMN, porcine cells were unable to proteolyze I alpha I. Moreover, in the incubation medium of pig PMN, triggered either by FMLP or PMA, no measurable elastase activity was evidenced. Therefore, we urge to better take into account species differences in functional responses of PMN, to explain the experimental results obtained in animal models of septic shock.     

New CW FIR laser lines obtained in ammonia pumped by a CO2 laser,using the Stark tuning method

We report fifty seven CW FIR emissions observed in NH₃, by resonant pumping with a CO₂ laser. Exact coincidences between IR absorption lines of the gas and emission lines of the CO₂ laser have been carried out by Stark tuning. IR frequency shifts, up to 30 GHz, have allowed the pumping of forty three NH₃ transitions. These FIR emissions correspond to thirty one different wavelengths in the 50–400 μm range; eighteen ones of them are new emitted wavelengths by pumping with the CO₂ laser.     

Determination of a microwave transistor model based on an experimental study of its internal structure

Based on an analysis of the physical structure of a bipolar interdigitated microwave transistor, a simple model is developed which accurately describes the high frequency small signal operation. The transistor model contains 15 elements. The values for ten of these parameters are determined by technological measurements using a special test pattern mask. The values of four of the parameters are determined through measurements made on the transistor, and one parameter is adjusted using the microwave S parameters measurements.A circuit model for the transistor package is also developed. The emitters are all arsenic doped, and the transistor structure does not exhibit a push effect. However, our measurements indicate that the emitter depth varies significantly with the width of the emitter window. This result shows that doping profiles measured on a uniformly doped test wafer may be quite different from the doping profile in the active base of a fine geometry microwave transistor. This implies that much recent work on microscopic models treating charge carrier transport may be invalid, since calculations are based on inaccurate doping profiles. The model in its present form neglects the physical mechanisms related to high current injection, but it describes accurately the transistor characteristics at normal operating currents and provides a valuable guide in optimizing the fabrication technology.     

Assessment of a remediation technique using the replacement of contaminated soils in kitchen gardens nearby a former lead smelter in Northern France

Vegetables cultivated in kitchen gardens that are strongly contaminated by heavy metals (Pb, Cd) may represent to consumers a means of exposure to these metals. This exposure is more problematic for those families that include a large quantity of home-grown vegetables in their diet. Researchers have shown that the majority of vegetables produced in kitchen gardens in the vicinity of the Metaleurop Nord smelter (Northern France) do not conform to European regulations. This study was carried out in three of these kitchen gardens. The concentrations of Cd and Pb in the topsoils were up to 24 and 3300 mg kg(-1) respectively. The method consisted of delineating a surface area of about 50 to 100 m(2) for each garden, then removing the contaminated soil and replacing it with a clean one. Seven species of vegetables were cultivated from 2003 to 2005 in the original contaminated soils and the remediated ones. The data showed a clear improvement of the quality of the vegetables cultivated in remediated soils, although 17% of them were still over the European legislative limits for foodstuffs. This suggested that there was a foliar contamination due to contaminated dust fallout coming from the closed smelter site and the adjacent polluted soils. In addition, the measurement of the Cd and Pb concentrations in the dust fallout showed that the substantial rise in metal concentrations in the remediated soil was not only due to atmospheric fallout. These results raise questions about possible technical, economic and sociological problems associated with this kind of remediation.     

Evaluation of statistical association measures for the automatic signal generation in pharmacovigilance.

Pharmacovigilance aims at detecting the adverse effects of marketed drugs. It is generally based on the spontaneous reporting of events thought to be the adverse effects of drugs. Spontaneous Reporting Systems (SRSs) supply huge databases that pharmacovigilance experts cannot exhaustively exploit without data mining tools. Data mining methods; i.e., statistical association measures in conjunction with signal generation criteria, have been proposed in the literature but there is no consensus regarding their applicability and efficiency, especially since such methods are difficult to evaluate on the basis of actual data. The objective of this paper is to evaluate association measures on simulated datasets obtained with SRS modeling. We compared association measures using the percentage of false positive signals among a given number of the most highly ranked drug-event combinations according to the values of the association measures. By considering 150 drugs and 100 adverse events, these percentages of false positives, among the 500 most highly ranked drug-event couples, vary from 1.1% to 53.4% (averages over 1000 simulated datasets). As the measures led to very different results, we could identify which measures appeared to be the most relevant for pharmacovigilance.     

Drug prescriptions for the elderly

The assessment od drugs taken by elderly people remains a difficult subject since epidemiological data on drug intake in this population is very limited. In a study undertaken in the context of the PAQUID project, drug use was screened in a group of 3,777 elderly people living at home in the Gironde and Dordogne regions of south-west France. In this group, 89.1% of subjects take at least one drug per day, with an average daily intake of 4.1 drugs by 41% of the group. One third of these elderly people take a benzodiazepine drug. Excessive intake of drugs by elderly people is a phenomenon encountered in Scandinavia and Italy but not in the United Kingdom.