Pretreatment of the cockroach cercal afferent/giant interneuron synapses with nicotinoids and neonicotinoids differently affects acetylcholine and nicotine-induced ganglionic depolarizations

We have recently demonstrated that neonicotinoid insecticides were able to act as agonists of postsynaptic nicotinic acetylcholine receptors (nAChRs) expressed at the synapse between the cercal nerve XI and the giant interneurons, in the sixth abdominal ganglion. In this work, we demonstrated that nicotinoids such as nornicotine acted as an agonist of nicotinic acetylcholine receptors expressed at cercal afferent/giant interneurons while cotinine was a poor agonist. Indeed, nornicotine induced a ganglionic depolarization which was blocked by the nicotinic antagonist mecamylamine. In addition, we found that pretreatment of the sixth abdominal ganglion with 1 and 10 muM nornicotine and cotinine had no significant effect on acetylcholine and nicotine-induced depolarization. But pretreatment with 1 and 10 muM acetamiprid and imidacloprid had a strong effect. 1 and 10 muM acetamiprid completely blocked acetylcholine-induced depolarization, whereas imidacloprid had a partial effect. The present work therefore suggests, in agreement with previous studies, that nornicotine and cotinine bind to distinct cockroach postsynaptic nAChRs, whereas acetamiprid and imidacloprid have competitive effects with acetylcholine and nicotine on ganglionic depolarization

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Non-AIDS defining cancers in the D:A:D Study-time trends and predictors of survival : a cohort study

BACKGROUND:Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors of these.METHODS:Individuals were followed from 1st January 2004/enrolment in study, until the earliest of a new NADC, 1st February 2010, death or six months after the patient's last visit. Incidence rates were estimated for each year of follow-up, overall and stratified by gender, age and mode of HIV acquisition. Cumulative risk of mortality following NADC diagnosis was summarised using Kaplan-Meier methods, with follow-up for these analyses from the date of NADC diagnosis until the patient's death, 1st February 2010 or 6 months after the patient's last visit. Factors associated with mortality following NADC diagnosis were identified using multivariable Cox proportional hazards regression.RESULTS:Over 176,775 person-years (PY), 880 (2.1%) patients developed a new NADC (incidence: 4.98/1000PY [95% confidence interval 4.65, 5.31]). Over a third of these patients (327, 37.2%) had died by 1st February 2010. Time trends for lung cancer, anal cancer and Hodgkin's lymphoma were broadly consistent. Kaplan-Meier cumulative mortality estimates at 1, 3 and 5 years after NADC diagnosis were 28.2% [95% CI 25.1-31.2], 42.0% [38.2-45.8] and 47.3% [42.4-52.2], respectively. Significant predictors of poorer survival after diagnosis of NADC were lung cancer (compared to other cancer types), male gender, non-white ethnicity, and smoking status. Later year of diagnosis and higher CD4 count at NADC diagnosis were associated with improved survival. The incidence of NADC remained stable over the period 2004-2010 in this large observational cohort.CONCLUSIONS:The prognosis after diagnosis of NADC, in particular lung cancer and disseminated cancer, is poor but has improved somewhat over time. Modifiable risk factors, such as smoking and low CD4 counts, were associated with mortality following a diagnosis of NADC

Expression du gène de la cholécystokinine. Mise en évidence à partir de biopsies duodénales chez l'homme

National audienc

Optical Diagnostics of RF Argon and Xenon Magnetron Discharges

A comparison of magnetron discharges in Ar and Xe gases with Al and BN targets has shown that a similar electron kinetic is producing about the same quantity of Ar and Xe metastable atoms: $(1{-}3) \times 10^{10}$ cm$^{-3}$ at gas pressures of 25 and 100 mTorr and RF powers, W, from 5 to 50 watts. The electron density is varying as $W^{\frac{1}{2}}$ in the two gases. The sputtering yields of Al and BN targets are lower in Xe than in Ar, by factors of 1.1–1.2 for Al and of 3 for BN.La comparaison de décharges magnétrons dans des gaz d'argon et de xénon, avec des cibles en Al et BN indique que des quantités équivalentes d'argon et de xénon métastables sont produites, à savoir $(1{-}3) \times 10^{10}$ cm$^{-3}$ à des pressions de 25 et 100 mTorr et des puissances RF, W, de 5 à 50 watts. La densité électronique varie comme $W^{\frac{1}{2}}$ dans les deux cas. Les taux de pulvérisation de cibles d'Al et de BN sont plus faibles dans le Xe que dans l'Ar, d'un facteur 1, 1– 1, 2 pour Al et 3 pour BN

Spectromètre utilisant des chambres à magnétostriction

We use a set of eight magnetostrictive spark chambers in a π- - proton backward scattering experiment. The main features of the chambers are described, including the way they were built - we emphasize the main performance (track localisation, repetition rate).Un ensemble de huit chambres à étincelles à magnétostriction est utilisé dans une expérience de diffusion π- - p vers l'arrière. On décrit les caractéristiques des chambres et leur mode de construction. Les performances obtenues - localisation des traces, taux de répétition - sont mises en évidence

Spectromètre utilisant des chambres à magnétostriction

Un ensemble de huit chambres à étincelles à magnétostriction est utilisé dans une expérience de diffusion π- - p vers l'arrière. On décrit les caractéristiques des chambres et leur mode de construction. Les performances obtenues - localisation des traces, taux de répétition - sont mises en évidence