Alien Registration- Drouin, Atila A. (Fairfield, Somerset County)

https://digitalmaine.com/alien_docs/9603/thumbnail.jp

A search for strong, ordered magnetic fields in Herbig Ae/Be stars

The origin of magnetic fields in intermediate-mass and high-mass stars is fundamentally a mystery. Clues toward solving this basic astrophysical problem can likely be found at the pre-main sequence (PMS) evolutionary stage. With this work, we perform the largest and most sensitive search for magnetic fields in pre-main sequence Herbig Ae/Be (HAeBe) stars. Sixty-eight observations of 50 HAeBe stars have been obtained in circularly polarised light using the FORS1 spectropolarimeter at the ESO VLT. An analysis of both Balmer and metallic lines reveals the possible presence of weak longitudinal magnetic fields in photospheric lines of two HAeBe stars, HD 101412 and BF Ori. The intensity of the longitudinal fields detected in HD 101412 and BF Ori suggest that they correspond to globally-ordered magnetic fields with surface intensities of order 1 kG. Monte Carlo simulations of the longitudinal field measurements of the undetected stars allow us to place an upper limits of about 300 G on the general presence of aligned magnetic dipole magnetic fields, and of about 500 G on perpendicular dipole fields. We find that the observed bulk incidence of magnetic HAeBe stars in our sample is 8-12%, in good agreement with that of magnetic main sequence stars of similar masses. We also find that the rms longitudinal field intensity of magnetically-detected HAeBe stars is similar to that of Ap stars and consistent with magnetic flux conservation during stellar evolution. These results are all in agreement with the hypothesis that the magnetic fields of main sequence Ap/Bp stars are fossils, which already exist within the stars at the pre-main sequence stage. Finally, we explore the ability of our new magnetic data to constrain magnetospheric accretion in Herbig Ae/Be stars.Comment: Accepted by Monthly Notices of the Royal Astronomical Society, 2007 January 11. Received 2007 January 11; in original form 2006 August 18. The paper contains 18 pages, 11 figures and 2 table

Alien Registration- Drouin, Corinne A. (Sanford, York County)

https://digitalmaine.com/alien_docs/2705/thumbnail.jp

HIV-Positive Men who Use the Internet to Meet Other Men in France: Results from the French “Net Gay Baromètre” Study

International audienceObjectives: With data from this biennial study, we will present some of the HIV-positive respondents’ social and sexual practices and identify predictors of regular unprotected anal intercourse in this group.Method: Men were recruited between January and April 2009 (n = 19 052) through personalized e-mailing on nine major websites for France’s diverse MSM population. Approximately 12 % of the sample was HIV-positive (n = 2229). Bivariate analyses (c2, t-test) as well as simple and multivariate logistic regressions were performed.Results: Compared to HIV-negative men, a significantly greater proportion of HIV-positive respondents were older, identified as homosexual, resided in the Paris metropolitan area, and were active members of the gay community. In particular, more HIV-positive men went to sex clubs, outdoor sex venues, and saunas in the previous 12 months. Drug use over this period of time was also more prevalent among HIV-positive men and this latter group had twice as many sexual partners as HIV-negative men. A significantly greater number of HIV-positive men reported regularly engaging in unprotected anal sex and about three times as many of them had “barebacked” in the past 12 months, compared to HIV-negative men: HIV-negative men engaged in less serosorting. The multivariate regression analysis found that regularly engaging in unprotected anal sex was significantly associated in HIV-positive men with the following factors: residing in the Paris metropolitan area, having more than 11 casual partners in the previous 12 months, meeting casual partners online, using dating websites for MSM that feature “hard” sexual practices, using drugs in the past 12 months, having contracted an STI over this period of time, not having been tested for HIV over this same period of time, engaging in bareback sex with a couple, having been in contact with a partner’s sperm during oral sex, engaging in group sex, and practicing fist fucking.Conclusion: This online survey reached many HIV-positive respondents. Overall, these men seem to be more exposed to some risk factors. This can be explained by positive HIV status but this could also be explained by sensation seeking, by a taste for risk, as well as by a disinterest in preventive strategies

Spectroscopic ellipsometry on thin titanium oxide layers grown on titanium by plasma oxidation

Abstract : Electronic devices based on tunnel junctions require tools able to accurately control the thickness of thin metal and oxide layers on the order of the nanometer. This article shows that multisample ellipsometry is an accurate method to reach this goal on plain uniform layers, in particular for titanium. From these measurements, the authors carefully studied the oxidation rate of titanium thin films in an oxygen plasma. The authors found that the oxide thickness saturates at 5.4±0.4 nm5.4±0.4 nm after 10 min in the plasma with an ion acceleration power of 30 W. Increasing this power to 240 W increases the saturation value to 7.6±0.4 nm7.6±0.4 nm. An x-ray photoelectron spectroscopy study of the oxide has shown that the oxide created by O2O2 plasma is stoichiometric (TiO2)(TiO2). The developed model was also used to measure the thicknesses of titanium and titanium oxide layers that have been polished using a chemical mechanical planarization process and a material removal rate of 5.9 nm/min is found with our planarization parameters. I. INTRODUCTIO

Editorial: InSAR for volcanoes and tectonics

Abstract not availabl

Biomechanical interactions of endodontically treated tooth implant-supported prosthesis under fatigue test with acoustic emission monitoring

International audienc

Sur la notion de contrat didactique

Les notions de contrat et de transposition didactiques sont actuellement centrales en didactique des mathématiques. Dans quelle mesure sont-elles spécifiques de ce domaine? Quelles adaptations sont nécessaires pour pouvoir les " transposer " à d'autres disciplines? Sans prétendre apporter de réponse élaborée, le texte qui suit rend compte de discussions et commentaires dans le cadre de l'équipe de didactique des sciences expérimentales de l'INR