A-STAR: The All-Sky Transient Astrophysics Reporter

The small mission A-STAR (All-Sky Transient Astrophysics Reporter) aims to locate the X-ray counterparts to ALIGO and other gravitational wave detector sources, to study the poorly-understood low luminosity gamma-ray bursts, and to find a wide variety of transient high-energy source types, A-STAR will survey the entire available sky twice per 24 hours. The payload consists of a coded mask instrument, Owl, operating in the novel low energy band 4-150 keV, and a sensitive wide-field focussing soft X-ray instrument, Lobster, working over 0.15-5 keV. A-STAR will trigger on ~100 GRBs/yr, rapidly distributing their locations.Comment: Accepted for the European Astronomical Society Publications Series: Proceedings of the Fall 2012 Gamma-Ray Burst Symposium held in Marbella, Spain, 8-12 Oct 201

A continuous non-linear shadowing model of columnar growth

We propose the first continuous model with long range screening (shadowing) that described columnar growth in one space dimension, as observed in plasma sputter deposition. It is based on a new continuous partial derivative equation with non-linear diffusion and where the shadowing effects apply on all the different processes.Comment: Fast Track Communicatio

Evaluating the longitudinal item and category stability of the SF-36 full and summary scales using rasch analysis

Introduction. The Medical Outcome Study Short Form 36 (SF-36) is widely used for measuring Health-Related Quality of Life (HRQoL) and has undergone rigorous psychometric evaluation using Classic Test Theory (CTT). However, Item Response Theory-based evaluation of the SF-36 has been limited with an overwhelming focus on individual scales and cross-sectional data. Purpose. This study aimed to examine the longitudinal item and category stability of the SF-36 using Rasch analysis. Method. Using data from the 1921-1926 cohort of the Australian Longitudinal Study on Women's Health, responses of the SF-36 from six waves of data collection were analysed. Rasch analysis using Winsteps version 3.92.0 was performed on all 36 items of the SF-36 and items that constitute the physical health and mental health scales. Results. Rasch analysis revealed issues with the SF-36 not detected using classical methods. Redundancy was seen for items on the total measure and both scales across all waves of data. Person separation indexes indicate that the measure lacks sensitivity to discriminate between high and low performances in this sample. The presence of Differential Item Functioning suggests that responses to items were influenced by locality and marital status. Conclusion. Previous evaluations of the SF-36 have relied on cross-sectional data; however, the findings of the current study demonstrate the longitudinal efficacy of the measure. Application of the Rasch Measurement Model indicated issues with internal consistency, generalisability, and sensitivity when the measure was evaluated as a whole and as both physical and mental health summary scales. Implications for future research are discussed

PIV-based dynamic model of EHD volume force produced by a surface dielectric barrier discharge

In this paper, an experimental measurement of the f low produced by a surface DBD plasma actuator has been conducted. One original aspect of these measurements by particle image velocimetry is the high acquisition rate for a PIV system (20 kHz). By using these highly- resolved flow measurements, the fluid flow velocity is used to estimate the spatial and temporal evolution of the EHD volume force. A reduced order model of this force has been constructed by proper orthogonal decomposition. Based on the analy sis of the time-resolved expansion coefficients and their associated spatial modes, it is shown that the volume force can be reconstructed by using a limited number of POD mode s (6 modes). This spatial and temporal filtering of the force fields remains faithful to t he original data and it will help in view of an implementation of such a source term in a numerical solver. The resulting dynamic model shows an alternation of positive and negative volume forc es. The strong positive EHD force developing in the glow regime of the DBD plasma discharge is v isualized in a time-resolved manner. This positive force is immediately followed by a strong negative volume force probably caused by the local flow deceleration

The INTEGRAL/SPI response and the Crab observations

The Crab region was observed several times by INTEGRAL for calibration purposes. This paper aims at underlining the systematic interactions between (i) observations of this reference source, (ii) in-flight calibration of the instrumental response and (iii) the development and validation of the analysis tools of the SPI spectrometer. It first describes the way the response is produced and how studies of the Crab spectrum lead to improvements and corrections in the initial response. Then, we present the tools which were developed to extract spectra from the SPI observation data and finally a Crab spectrum obtained with one of these methods, to show the agreement with previous experiments. We conclude with the work still ahead to understand residual uncertainties in the response.Comment: 4 pages, 4 figures, Proc. of the 5th INTEGRAL Workshop (Feb. 16-20 2004), to be published by ES

The SVOM gamma-ray burst mission

We briefly present the science capabilities, the instruments, the operations, and the expected performance of the SVOM mission. SVOM (Space-based multiband astronomical Variable Objects Monitor) is a Chinese-French space mission dedicated to the study of Gamma-Ray Bursts (GRBs) in the next decade. The SVOM mission encompasses a satellite carrying four instruments to detect and localize the prompt GRB emission and measure the evolution of the afterglow in the visible band and in X-rays, a VHF communication system enabling the fast transmission of SVOM alerts to the ground, and a ground segment including a wide angle camera and two follow-up telescopes. The pointing strategy of the satellite has been optimized to favor the detection of GRBs located in the night hemisphere. This strategy enables the study of the optical emission in the first minutes after the GRB with robotic observatories and the early spectroscopy of the optical afterglow with large telescopes to measure the redshifts. The study of GRBs in the next decade will benefit from a number of large facilities in all wavelengths that will contribute to increase the scientific return of the mission. Finally, SVOM will operate in the era of the next generation of gravitational wave detectors, greatly contributing to searches for the electromagnetic counterparts of gravitational wave triggers at Xray and gamma-ray energies.Comment: 13 pages, 5 figures, published by PoS, proceedings of the conference Swift: 10 Years of Discovery, 2-5 December 2014, La Sapienza University, Rome, Ital

SIMBOL-X : a new generation hard X-ray telescope

SIMBOL-X is a hard X-ray mission, operating in the 0.5-70 keV range, which is proposed by a consortium of European laboratories for a launch around 2010. Relying on two spacecraft in a formation flying configuration, SIMBOL-X uses a 30 m focal length X-ray mirror to achieve an unprecedented angular resolution (30 arcsec HEW) and sensitivity (100 times better than INTEGRAL below 50 keV) in the hard X-ray range. SIMBOL-X will allow to elucidate fundamental questions in high energy astrophysics, such as the physics of accretion onto Black Holes, of acceleration in quasar jets and in supernovae remnants, or the nature of the hard X-ray diffuse emission. The scientific objectives and the baseline concepts of the mission and hardware design are presented.Comment: 12 pages, 16 fig., Proc. SPIE conf. 5168, San Diego, Aug. 200

Hypernovae/GRB in the Galactic Center as possible sources of Galactic Positrons

The observation of a strong and extended positron-electron line annihilation emission in the central regions of the Galaxy by INTEGRAL-SPI, consistent with the Galactic bulge geometry, without any counterpart in the gamma-ray range, neither at high energy nor in the 1809 keV $^{26}$Al decay line, is challenging. Leaving aside the geometrical question, we address the problem of the adequate positron sources, showing the potentiality of a new category of SN Ic, exemplified by SN2003dh, which is associated to a gamma-ray burst. This kind of supernova/hypernova/GRB event is interpreted as the result of a bipolar Wolf-Rayet explosion, which produces a large amount of $^{56}$Ni and ejects it at high velocity along the rotation axis. The bulk of positrons resulting from $^{56}$Co decay escapes in the surrounding medium due to the rapid thinning of the ejecta in the polar direction. We show that a rate of about 0.02 SN2003dh-like events per century in the central region of the Galaxy is sufficient to explain the positron flux detected by INTEGRAL-SPI. In order to explain this flux by SN Ia events alone, a rate of 0.5 per century is necessary, much higher than indicated by Galactic evolutionary models applied to the bulge. Further observations of late light curves of SNe Ia and SNe Ic in the bulge of spiral galaxies, together with 3D hydrodynamic calculations of anisotropic ejections of $^{56}$Ni in SN Ic/GRB events, will allow to estimate the separate contributions of SNe Ia and SNe Ic to positron injection.Comment: 7 pages, 0 figures, accepted for publication in Astrophysical Journal Letters, 2003 12 0

The role of the genetic counsellor: a systematic review of research evidence

In Europe, genetic counsellors are employed in specialist genetic centres or other specialist units. According to the European Board of Medical Genetics, the genetic counsellor must fulfil a range of roles, including provision of information and facilitation of psychosocial adjustment of the client to their genetic status and situation. To evaluate the extent to which genetic counsellors fulfil their prescribed roles, we conducted a systematic review of the published relevant scientific evidence. We searched five relevant electronic databases (Medline, CINAHL, SocIndex, AMED and PsychInfo) using relevant search terms and handsearched four subject-specific journals for research-based papers published in English between 1 January 2000 and 30 June 2013. Of 419 potential papers identified initially, seven satisfied the inclusion criteria for the review. Themes derived from the thematic analysis of the data were: (i) rationale for genetic counsellors to provide care, (ii) appropriate roles and responsibilities and (iii) the types of conditions included in the genetic counsellor caseload. The findings of this systematic review indicate that where genetic counsellors are utilised in specialist genetic settings, they undertake a significant workload associated with direct patient care and this appears to be acceptable to patients. With the burden on genetic services, there is an argument for the increased use of genetic counsellors in countries where they are under-utilised. In addition, roles undertaken by genetic counsellors in specialist genetic settings could be adapted to integrate genetic counsellors into multi-disciplinary teams in other specialisms