Laser Guide Star Adaptive Optics Integral Field Spectroscopy of a Tightly Collimated Bipolar Jet from the Herbig Ae star LkHa 233

We have used the integral field spectrograph OSIRIS and laser guide star adaptive optics at Keck Observatory to obtain high angular resolution (0.06"), moderate spectral resolution (R ~ 3800) images of the bipolar jet from the Herbig Ae star LkHa 233, seen in near-IR [Fe II] emission at 1.600 & 1.644 microns. This jet is narrow and tightly collimated, with an opening angle of only 9 degrees, and has an average radial velocity of ~ 100 km/s. The jet and counterjet are asymmetric, with the red-shifted jet much clumpier than its counterpart at the angular resolution of our observations. The observed properties are in general similar to jets seen around T Tauri stars, though it has a relatively large mass flux of (1.2e-7 +- 0.3e-7) M_sun/year, near the high end of the observed mass flux range around T Tauri stars. We also spatially resolve an inclined circumstellar disk around LkHa 233, which obscures the star from direct view. By comparison with numerical radiative transfer disk models, we estimate the disk midplane to be inclined i = 65 +- 5 degrees relative to the plane of the sky. Since the star is seen only in scattered light at near-infrared wavelengths, we detect only a small fraction of its intrinsic flux. Because previous estimates of its stellar properties did not account for this, either LkHa 233 must be located closer than the previously believed, or its true luminosity must be greater than previously supposed, consistent with its being a ~4 M_sun star near the stellar birthline.Comment: Accepted for publication in the Ap

Waiting in the Wings: Reflected X-ray Emission from the Homunculus Nebula

We report the first detection of X-ray emission associated with the Homunculus Nebula which surrounds the supermassive star Eta Carinae. The emission is characterized by a temperature in excess of 100 MK, and is consistent with scattering of the time-delayed X-ray flux associated with the star. The nebular emission is bright in the northwestern lobe and near the central regions of the Homunculus, and fainter in the southeastern lobe. We also report the detection of an unusually broad Fe K fluorescent line, which may indicate fluorescent scattering off the wind of a companion star or some other high velocity outflow. The X-ray Homunculus is the nearest member of the small class of Galactic X-ray reflection nebulae, and the only one in which both the emitting and reflecting sources are distinguishable.Comment: 17 pages, 5 figures, accepted by Ap

General Practitioner Autism Training and Mandatory Medical Training: A Cross-Sectional Study of GPs’ Knowledge, Attitudes and Practices

Numerous physical conditions appear with increased frequency in autistic individuals in comparison to their non-autistic peers. These co-existing conditions are known to lead to higher morbidity, lower quality of life, and lower life expectancy in autisticadults. There is substantial evidence in the literature that many, if not most, General Practitioners (GPs) in the United Kingdom do not have the necessary understanding of autism to enable them to offer the same standard of service to their autistic patients that their non-autistic patients receive. This research project was set up, inter alia, to explore the attitudes of GPs to the introduction of autism training and the contentious issue of making GP training on any subject mandatory rather than voluntary. We wanted to better understand how autism training for GPs might be developed to maximise "take-up" and “buy-in” given that the demands on their time, including training demands, are such that autism is only one of many conditions vying for training time and mandatory training is anathema to many GPs. Key findings were that nearly three quarters of our respondents strongly agreed that training in autism is important for GPs, the same percentage of our participants had received little or no formal autismtraining, and there was a general dislike of any training being made mandatory. Training should be focused on barriers faced by autistic people in accessing healthcare as well as on autism as a medical condition. No respondent had received a significant level of training in autism although 40% of participants who had received training had been trained by an autistic individual

An X-ray investigation of the NGC 346 field in the SMC (3): XMM-Newton data

We present new XMM-Newton results on the field around the NGC346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two XMM-Newton observations were obtained, respectively, six months before and six months after the previously published Chandra data. Of the 51 X-ray sources detected with XMM-Newton, 29 were already detected with Chandra. Comparing the properties of these X-ray sources in each of our three datasets has enabled us to investigate their variability on times scales of a year. Changes in the flux levels and/or spectral properties were observed for 21 of these sources. In addition, we discovered long-term variations in the X-ray properties of the peculiar system HD5980, a luminous blue variable star, that is likely to be a colliding wind binary system, which displayed the largest luminosity during the first XMM-Newton observation.Comment: 19 pages, 5 figures (in gif), accepted by ApJ, also available from http://vela.astro.ulg.ac.be/Preprints/P89/index.htm

Quasiparticles in the vortex state of V3Si

Low-energy quasiparticle excitations in the vortex state of the superconductor V3Si have been investigated using the de Haas-van Alphen effect. Quantum oscillations persist to surprisingly low values of B0/B(c2) is similar to 0.6 and T/T(c) is similar to 0.001. The superconducting state introduces a field-dependent quasiparticle damping which has a value HBAR tau-1 almost-equal-to 0.25 DELTA at the lowest fields investigated, considerably less than the superconducting gap DELTA. Quantum oscillations are attributed to the presence of a gapless excitation spectrum and may be a universal characteristic of superconductors in the vortex state

Recent Decisions

Comments on recent decisions by George N. Tompkins, James M. Corcoran, John L. Rosshirt, Ronald P. Mealey, Patrick J. Foley, Lawrence J. Dolan, Edward J. Griffin, John W. Thornton, and Thomas R. King

EFBAT: exact family-based association tests

Background: Family-based association tests are important tools for investigating genetic risk factors of complex diseases. These tests are especially valuable for being robust to population structure. We introduce a tool, EFBAT, which performs exact family-based tests of association for X-chromosome and autosomal biallelic markers. Results: The program EFBAT extends a network algorithm previously applied to autosomal markers to include the X-chromosome and to perform tests of association under the null hypotheses "no association, no linkage" and "no association in the presence of linkage" under additive, dominant and recessive genetic models. These tests are valid regardless of patterns of missing familial data. Conclusion: The general framework for performing exact family-based association tests has been usefully extended to the X-chromosome, particularly for the hypothesis of "no association in the presence of linkage" and for different genetic models

Ginzburg-Landau-Gor'kov Theory of Magnetic oscillations in a type-II 2-dimensional Superconductor

We investigate de Haas-van Alphen (dHvA) oscillations in the mixed state of a type-II two-dimensional superconductor within a self-consistent Gor'kov perturbation scheme. Assuming that the order parameter forms a vortex lattice we can calculate the expansion coefficients exactly to any order. We have tested the results of the perturbation theory to fourth and eight order against an exact numerical solution of the corresponding Bogoliubov-de Gennes equations. The perturbation theory is found to describe the onset of superconductivity well close to the transition point $H_{c2}$. Contrary to earlier calculations by other authors we do not find that the perturbative scheme predicts any maximum of the dHvA-oscillations below $H_{c2}$. Instead we obtain a substantial damping of the magnetic oscillations in the mixed state as compared to the normal state. We have examined the effect of an oscillatory chemical potential due to particle conservation and the effect of a finite Zeeman splitting. Furthermore we have investigated the recently debated issue of a possibility of a sign change of the fundamental harmonic of the magnetic oscillations. Our theory is compared with experiment and we have found good agreement.Comment: 39 pages, 8 figures. This is a replacement of supr-con/9608004. Several sections changed or added, including a section on the effect of spin and the effect of a conserved number of particles. To be published in Phys. Rev.