Tough on Scholarship

This series of three articles (that\u27s why it\u27s a trilogy, duh-h-h) chronicles the legal-academic career of one S. Breckinridge Tushingham ( Breck for short). As the trilogy unfolds, Breck works his way up (or maybe it\u27s down) from his first academic position to an established professorship to dean of the South Soybean (Soso) State University law school. In the process of recording his professional history, and thus memorializing it for the ages, Breck provides (probably defamatory) insights into the American legal academy

Bacteria isolated from lung modulate asthma susceptibility in mice

Asthma is a chronic, non-curable, multifactorial disease with increasing incidence in industrial countries. This study evaluates the direct contribution of lung microbial components in allergic asthma in mice. Germ-Free and Specific-Pathogen-Free mice display similar susceptibilities to House Dust Mice-induced allergic asthma, indicating that the absence of bacteria confers no protection or increased risk to aeroallergens. In early life, allergic asthma changes the pattern of lung microbiota, and lung bacteria reciprocally modulate aeroallergen responsiveness. Primo-colonizing cultivable strains were screened for their immunoregulatory properties following their isolation from neonatal lungs. Intranasal inoculation of lung bacteria influenced the outcome of allergic asthma development: the strain CNCM I 4970 exacerbated some asthma features whereas the pro-Th1 strain CNCM I 4969 had protective effects. Thus, we confirm that appropriate bacterial lung stimuli during early life are critical for susceptibility to allergic asthma in young adults

Réactions de radicaux halogénés (chlorés, bromés) d'intérêt atmosphérique

In this work, we have studied the kinetics and mechanisms of reactions of bromine and chlorine containing radicals of atmospheric interest: on one hand, some reactions of BrOx (Br, BrO) and ClOx (Cl, ClO) radicals with HOx (OH, HO2) radicals, in order to estimate their impact on halogenated compound partitioning in the global stratosphere, between active and sink species, in relation to stratospheric ozone depletion ; on the other hand, some reactions between these halogenated radicals and dimethylsulfoxide (DMSO), an intermediate species in the oxidation of dimethylsulphur (DMS) emitted by oceans, in order to evaluate the potential contribution of these reactions in the oxidation of DMSO. These reactions were studied at 1 torr pressure of helium, using the dicharge-flow mass spectrometric method.For the reactions between halogenated and HOx radicals, the results obtained show these reactions are additional sources of the reservoir species HX (X = Br, Cl) in the stratosphere. However, the values of the rate constants seem to be unable to fully explain the discrepancies between observed and modeled HX concentrations in the stratosphere, and thus the partitioning of bromine and chlorine species between active species and reservoirs.With respect to DMSO, this work confirms that reactions with chlorinated and brominated radicals do not contribute significantly to its oxidation, mainly due to the OH radical in the gas phase.Au cours de ce travail, nous avons étudié les cinétiques et mécanismes de plusieurs réactions de radicaux bromés et chlorés d'intérêt pour la chimie atmosphérique : d'une part, des réactions des radicaux halogénés BrOx (Br, BrO) et ClOx (Cl, ClO) avec les radicaux hydroxy-oxygénés (OH, HO2), afin d'évaluer leur impact sur la répartition des composés halogénés dans la stratosphère globale entre espèces actives et réservoirs de ces espèces, en lien avec la diminution de l'ozone stratosphérique ; d'autre part, des réactions entre ces mêmes radicaux halogénés et le diméthylsulfoxyde (DMSO), intermédiaire d'oxydation du sulfure de diméthyle (DMS) émis par les océans, afin d'évaluer la contribution possible de ces réactions à l'oxydation du DMSO. Les réactions ont été étudiées par la technique du réacteur à écoulement couplé à la spectrométrie de masse, à une pression de 1 torr d'hélium.Pour les réactions entre les radicaux halogénés et hydro-oxygénés, les résultats obtenus montrent que les réactions étudiées constituent des sources supplémentaires de l'espèce réservoir HX (X = Br, Cl) dans la stratosphère globale. Toutefois, les valeurs des constantes de vitesse obtenues semblent insuffisantes pour expliquer totalement l'écart entre observations et modélisations des concentrations de HX dans la stratosphère, et donc le partage des composés halogénés entre espèces actives et réservoirs.Concernant le DMSO, ce travail confirme que les réactions avec les radicaux chlorés et bromés ne contribuent pas de manière significative à son oxydation, celle-ci étant amorcée principalement en phase gazeuse par le radical OH

Current issues linked to particulate matter in North-Western Europe

International audienc

Particules fines et nanoparticules : sources, composition chimique et processus en air intérieur

National audienc

Réactions de radicaux halogénés (chlorés, bromés) d'intérêt atmosphérique

ORLEANS-BU Sciences (452342104) / SudocSudocFranceF

Kinetic and mechanistic study of the reactions of OH with IBr and HOI

International audienceThe kinetics and mechanism of the reactions of OH radicals with IBr and HOI have been studied using the mass spectrometric discharge-flow method at 320 K and at a total pressure of 1 Torr of Helium. The rate constant of the reaction OH + IBr → products (1) was measured under pseudo-first order conditions either in excess of IBr or in excess of OH radicals: k1 = (1.4 ± 0.4) × 10−10 cm3 molecule−1 s−1. Both HOI and HOBr were detected as products of reaction (1) and the branching ratios 0.84 ± 0.07 and 0.14 ± 0.05, respectively, were found for the channels forming these species. For the reaction OH + HOI → products (2) the total rate constant was determined from the kinetics of HOI consumption in excess of OH radicals: k2 = (5.0 ± 1.2) × 10−12 cm3 molecule−1 s−1

A laboratory intercomparison of CPC and SMPS measurements of submicron aerosols

International audienc