1,110 research outputs found

    Solar gravitational energy and luminosity variations

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    Due to non-homogeneous mass distribution and non-uniform velocity rate inside the Sun, the solar outer shape is distorted in latitude. In this paper, we analyze the consequences of a temporal change in this figure on the luminosity. To do so, we use the Total Solar Irradiance (TSI) as an indicator of luminosity. Considering that most of the authors have explained the largest part of the TSI modulation with magnetic network (spots and faculae) but not the whole, we could set constraints on radius and effective temperature variations (dR, dT). However computations show that the amplitude of solar irradiance modulation is very sensitive to photospheric temperature variations. In order to understand discrepancies between our best fit and recent observations of Livingston et al. (2005), showing no effective surface temperature variation during the solar cycle, we investigated small effective temperature variation in irradiance modeling. We emphasized a phase-shift (correlated or anticorrelated radius and irradiance variations) in the (dR, dT)-parameter plane. We further obtained an upper limit on the amplitude of cyclic solar radius variations, deduced from the gravitational energy variations. Our estimate is consistent with both observations of the helioseismic radius through the analysis of f-mode frequencies and observations of the basal photospheric temperature at Kitt Peak. Finally, we suggest a mechanism to explain faint changes in the solar shape due to variation of magnetic pressure which modifies the granules size. This mechanism is supported by our estimate of the asphericity-luminosity parameter, which implies an effectiveness of convective heat transfer only in very outer layers of the Sun.Comment: 17 pages, 2 figure, 1 table, published in New Astronom

    Specialty choice in UK junior doctors: Is psychiatry the least popular specialty for UK and international medical graduates?

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    <p>Abstract</p> <p>Background</p> <p>In the UK and many other countries, many specialties have had longstanding problems with recruitment and have increasingly relied on international medical graduates to fill junior and senior posts. We aimed to determine what specialties were the most popular and desirable among candidates for training posts, and whether this differed by country of undergraduate training.</p> <p>Methods</p> <p>We conducted a database analysis of applications to Modernising Medical Careers for all training posts in England in 2008. Total number of applications (as an index of popularity) and applications per vacancy (as an index of desirability) were analysed for ten different specialties. We tested whether mean consultant incomes correlated with specialty choice.</p> <p>Results</p> <p>In, 2008, there were 80,949 applications for specialty training in England, of which 31,434 were UK graduates (39%). Among UK medical graduates, psychiatry was the sixth most popular specialty (999 applicants) out of 10 specialty groups, while it was fourth for international graduates (5,953 applicants). Among UK graduates, surgery (9.4 applicants per vacancy) and radiology (8.0) had the highest number of applicants per vacancy and paediatrics (1.2) and psychiatry (1.1) the lowest. Among international medical graduates, psychiatry had the fourth highest number of applicants per place (6.3). Specialty popularity for UK graduates was correlated with predicted income (p = 0.006).</p> <p>Conclusion</p> <p>Based on the number of applicants per place, there was some consistency in the most popular specialties for both UK and international medical graduates, but there were differences in the popularity of psychiatry. With anticipated decreases in the number of new international medical graduates training in the UK, university departments and professional associations may need to review strategies to attract more UK medical graduates into certain specialties, particularly psychiatry and paediatrics.</p

    Compressed sensing and robust recovery of low rank matrices

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    In this paper, we focus on compressed sensing and recovery schemes for low-rank matrices, asking under what conditions a low-rank matrix can be sensed and recovered from incomplete, inaccurate, and noisy observations. We consider three schemes, one based on a certain Restricted Isometry Property and two based on directly sensing the row and column space of the matrix. We study their properties in terms of exact recovery in the ideal case, and robustness issues for approximately low-rank matrices and for noisy measurements

    Did female prisoners with mental disorders receive psychiatric treatment before imprisonment?

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    © 2015 Mundt et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BackgroundThroughout the world, high prevalence rates of mental disorders have been found in prison populations, especially in females. It has been suggested that these populations do not access psychiatric treatment. The aim of this study was to establish rates of psychiatric in- and outpatient treatments prior to imprisonment in female prisoners and to explore reasons for discontinuation of such treatments.Methods150 consecutively admitted female prisoners were interviewed in Berlin, Germany. Socio-demographic characteristics, mental disorders, and previous psychiatric in- and outpatient treatments were assessed by trained researchers. Open questions were used to explore reasons for ending previous psychiatric treatment.ResultsA vast majority of 99 prisoners (66%; 95% CI: 58¿73) of the total sample reported that they had previously been in psychiatric treatment, 80 (53%; 95 CI: 45¿61) in inpatient treatment, 62 (41%; 95 CI: 34¿49) in outpatient treatment and 42 (29%; 21¿39) in both in- and outpatient treatments. All prisoners with psychosis and 72% of the ones with any lifetime mental health disorder had been in previous treatment. The number of inpatient treatments and imprisonments were positively correlated (rho¿=¿0.27; p¿<¿0.01). Inpatient treatment was described as successfully completed by 56% (N¿=¿41) of those having given reasons for ending such treatment, whilst various reasons were reported for prematurely ending outpatient treatments.ConclusionThe data do not support the notion of a general `mental health treatment gap¿ in female prisoners. Although inpatient care is often successfully completed, repeated inpatient treatments are not linked with fewer imprisonments. Improved transition from inpatient to outpatient treatment and services that engage female prisoners to sustained outpatient treatments are needed

    Evolution of motif variants and positional bias of the cyclic-AMP response element

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    BACKGROUND: Transcription factors regulate gene expression by interacting with their specific DNA binding sites. Some transcription factors, particularly those involved in transcription initiation, always bind close to transcription start sites (TSS). Others have no such preference and are functional on sites even tens of thousands of base pairs (bp) away from the TSS. The Cyclic-AMP response element (CRE) binding protein (CREB) binds preferentially to a palindromic sequence (TGACGTCA), known as the canonical CRE, and also to other CRE variants. CREB can activate transcription at CREs thousands of bp away from the TSS, but in mammals CREs are found far more frequently within 1 to 150 bp upstream of the TSS than in any other region. This property is termed positional bias. The strength of CREB binding to DNA is dependent on the sequence of the CRE motif. The central CpG dinucleotide in the canonical CRE (TGACGTCA) is critical for strong binding of CREB dimers. Methylation of the cytosine in the CpG can inhibit binding of CREB. Deamination of the methylated cytosines causes a C to T transition, resulting in a functional, but lower affinity CRE variant, TGATGTCA. RESULTS: We performed genome-wide surveys of CREs in a number of species (from worm to human) and showed that only vertebrates exhibited a CRE positional bias. We performed pair-wise comparisons of human CREs with orthologous sequences in mouse, rat and dog genomes and found that canonical and TGATGTCA variant CREs are highly conserved in mammals. However, when orthologous sequences differ, canonical CREs in human are most frequently TGATGTCA in the other species and vice-versa. We have identified 207 human CREs showing such differences. CONCLUSION: Our data suggest that the positional bias of CREs likely evolved after the separation of urochordata and vertebrata. Although many canonical CREs are conserved among mammals, there are a number of orthologous genes that have canonical CREs in one species but the TGATGTCA variant in another. These differences are likely due to deamination of the methylated cytosines in the CpG and may contribute to differential transcriptional regulation among orthologous genes

    Multi-GeV Electron Generation Using Texas Petawatt Laser

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    We present simulation results and experimental setup for multi-GeV electron generation by a laser plasma wake field accelerator (LWFA) driven by the Texas Petawatt (TPW) laser. Simulations show that, in plasma of density n(e) = 2 - 4 x cm(-3), the TPW laser pulse (1.1 PW, 170 fs) can self-guide over 5 Rayleigh ranges, while electrons self-injected into the LWFA can accelerate up to 7 GeV. Optical diagnostic methods employed to observe the laser beam self-guiding, electron trapping and plasma bubble formation and evolution are discussed. Electron beam diagnostics, including optical transition radiation (OTR) and electron gamma ray shower (EGS) generation, are discussed as well.Physic

    Effectiveness of current policing-related mental health interventions in England and Wales and Crisis Intervention Teams as a future potential model: a systematic review

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    Background Experiencing mental ill health adds a layer of complexity for individuals in touch with the justice system and for those responsible for working in the justice service with these individuals, such as frontline police officers. In England and Wales, there are three commonly used but not necessarily commonly designed or operated, mental health interventions associated with policing, Liaison and Diversion, Street Triage and specialist staff embedded in Police Contact Control Rooms. A fourth US designed model, Crisis Intervention Teams (CITs), is now attracting some interest in England and Wales, and these four are to be considered in this review. A fifth intervention, Mental Health Courts, was trialed but has now been abandoned in England and Wales and so has been excluded, but remains in use elsewhere. In recent years, there has been an increase in the level of investment related to these intervention options. This has largely been without an evidence base being available to aid design, structure, and consistency of approach. The review will address this gap and provide a systematic review of each of these options. This will provide a baseline of research evidence for those who commission and provide services for individuals experiencing mental ill health and who are in contact with the justice system. Methods Twenty-nine relevant databases and sources have been selected which will be systematically searched to locate relevant studies. These studies have to meet the set inclusion criteria which require them to report an objective outcome measure(s) in respect of offending or mental health outcomes and to have an experimental or quasi-experimental design including a comparator group(s) or a pre/post comparison. The review will exclude PhD theses, papers in non-English languages and papers published prior to 1980. Keywords have been collected through canvassing experts’ opinion, literature review, controlled vocabulary and reviewing the results of a primary scoping review carried out to aid the development of the PICO, composed of Population/Participants, Intervention/Indicator, Comparator/Control, and Outcomes. For the proposed review, the key elements of the PICO are the following: persons with mental health problems, symptoms or diagnoses who come into contact with the police; interventions involving partnership working between police and mental health nurses and related professionals to divert those with mental health problems away from criminal justice processes; comparisons with control groups or areas where such interventions have not been introduced; and outcomes concerning criminal justice and health outcomes. The results of the searches will be screened using the set criteria and the selected papers reviewed and analysed to allow findings regarding these interventions to be reported. Discussion The objectives of the review are firstly to identify and report research on the relevant interventions, nationally and internationally and then secondly to consider, when possible, which interventions or aspects of those interventions are effective. This is judged with regard to changes in mental health status or service use and future offending behaviour. The approaches to be considered have gained a good deal of support and funding over recent years, and this review will provide a systematic review of the underpinning research evidence to inform future commissioning, service design and investment decisions
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