XMM-Newton reveals ~100 new LMXBs in M31 from variability studies

We have conducted a survey of X-ray sources in XMM-Newton observations of M31, examining their power density spectra (PDS) and spectral energy distributions (SEDs). Our automated source detection yielded 535 good X-ray sources; to date, we have studied 225 of them. In particular, we examined the PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of PDS. At low accretion rates, the PDS is characterised by a broken power law, with the spectral index changing from ~0 to ~1 at some frequency in the range \~0.01--1 Hz; we refer to such PDS as Type A. At higher accretion rates, the PDS is described by a simple power law; we call these PDS Type B. Of the 225 sources studied to date, 75 exhibit Type A variability, and are almost certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore, they are mostly found near the centre of M31. Furthermore, most of the X-ray population in the disc are associated with the spiral arms, making them likely high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A variability, while many central X-ray sources (LMXBs) in the same luminosity range do. Hence the PDS may distinguish between LMXBs and HMXBs in this luminosity range.Comment: 4 pages, 2 figures. To appear in proceedings of IAUS230: "Populations of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A. Meurs and G. Fabbian

SN contributions to GRB lightcurves

Several of the nearer GRB afterglows (up to z ∼ 1) show bumps in their lightcurves that have been interpreted as contributions from associated SNae. Thebumps arecustomarily modelled likethet ype-Ic SN 1998bw, but wein vestigate here, for several low-z GRBs, whether other SN types might offer alternatives. While several SN types are ruled out, or are unlikely, a type “II-bl” could also explain the observations

The Role of Political Skill in the Stressor–Outcome Relationship: Differential Predictions for Self- and Other-Reports of Political Skill

The beneficial role of political skill in stress reactions and performance evaluations has been demonstrated in a substantial amount of empirical research. Most of the research, however, has focused on self-perceptions of political skill. This study examines the differential moderating effects of self- vs. other-rated political skill in the conflict – emotional burnout and performance relationships, using two samples including non-academic staff employees of a large university (N = 839) and a variety of office and retail employees from an automotive organization (N = 142). We argue that self-reported political skill moderates the relationship between conflict and a self-reported strain-related outcome that is important to the individual (i.e., emotional burnout), but that supervisor-rated political skill does not moderate this relationship. Further, we argue that supervisor-rated political skill moderates the relationship between conflict and an outcome important to the supervisor and the organization (i.e., job performance), but that self-reported political skill does not moderate this relationship. Findings partially support our hypotheses as both self and supervisor-rated political skill neutralized the negative effects of conflict on burnout, but only supervisor-rated political skill neutralized the negative effects of conflict on performance. Limitations and directions for future research are discussed

Prescription of the first prosthesis and later use in children with congenital unilateral upper limb deficiency: A systematic review

Background: The prosthetic rejection rates in children with an upper limb transversal reduction deficiency are considerable. It is unclear whether the timing of the first prescription of the prosthesis contributes to the rejection rates. Objective: To reveal whether scientific evidence is available in literature to confirm the hypothesis that the first prosthesis of children with an upper limb deficiency should be prescribed before two years of age. We expect lower rejection rates and better functional outcomes in children fitted at young age. Methods: A computerized search was performed in several databases (Medline, Embase, Cinahl, Amed, Psycinfo, PiCarta and the Cochrane database). A combination of the following keywords and their synonyms was used: "prostheses, upper limb, upper extremity, arm and congenital''. Furthermore, references of conference reports, references of most relevant studies, citations of most relevant studies and related articles were checked for relevancy. Results: The search yielded 285 publications, of which four studies met the selection criteria. The methodological quality of the studies was low. All studies showed a trend of lower rejection rates in children who were provided with their first prosthesis at less than two years of age. The pooled odds ratio of two studies showed a higher rejection rate in children who were fitted over two years of age ( pooled OR 3.6, 95% CI 1.6-8.0). No scientific evidence was found concerning the relation between the age at which a prosthesis was prescribed for the first time and functional outcomes. Conclusion: In literature only little evidence was found for a relationship between the fitting of a first prosthesis in children with a congenital upper limb deficiency and rejection rates or functional outcomes. As such, clinical practice of the introduction of a prosthesis is guided by clinical experience rather than by evidence-based medicine

The interactive effects of conscientiousness, openness to experience, and political skill on job performance in complex jobs: The importance of context

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordCaveats concerning the ability of personality to predict job performance have been raised because of seemingly modest criterion-related validity. The goal of the present research was to test whether narrowing the context via the type of job (i.e., jobs with complex task demands) and adding a social skill-related moderator (i.e., political skill) would improve performance prediction. Further, along with political skill, a broad factor of personality (i.e., conscientiousness which had demonstrated in prior research to have the strongest criterion validity) was paired with a narrow construct (i.e., learning approach that is closely related to openness to experience) in a three-way interactive prediction of supervisor-rated task performance. With the employeesupervisor dyads among professionals, but not with the control group of non-professional employees, task performance was predicted by the three-way interaction, such that those high on all three received the highest performance ratings. Implications, strengths and limitations, and directions for future research are discussed