269 research outputs found

    Gaia Data Release 2: Short-timescale variability processing and analysis

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    The Gaia DR2 sample of short-timescale variable candidates results from the investigation of the first 22 months of Gaia photometry for a subsample of sources at the Gaia faint end. For this exercise, we limited ourselves to the case of suspected rapid periodic variability. Our study combines fast-variability detection through variogram analysis, high-frequency search by means of least-squares periodograms, and empirical selection based on the investigation of specific sources seen through the Gaia eyes (e.g. known variables or visually identified objects with peculiar features in their light curves). The progressive definition and validation of this selection criterion also benefited from supplementary ground-based photometric monitoring of a few preliminary candidates, performed at the Flemish Mercator telescope (Canary Islands, Spain) between August and November 2017. We publish a list of 3,018 short-timescale variable candidates, spread throughout the sky, with a false-positive rate up to 10-20% in the Magellanic Clouds, and a more significant but justifiable contamination from longer-period variables between 19% and 50%, depending on the area of the sky. Although its completeness is limited to about 0.05%, this first sample of Gaia short-timescale variables recovers some very interesting known short-period variables, such as post-common envelope binaries or cataclysmic variables, and brings to light some fascinating, newly discovered variable sources. In the perspective of future Gaia data releases, several improvements of the short-timescale variability processing are considered, by enhancing the existing variogram and period-search algorithms or by classifying the identified candidates. Nonetheless, the encouraging outcome of our Gaia DR2 analysis demonstrates the power of this mission for such fast-variability studies, and opens great perspectives for this domain of astrophysics

    Gaia Data Release 2: All-sky classification of high-amplitude pulsating stars

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    Out of the 1.69 billion sources in the Gaia Data Release 2 (DR2), more than half a million are published with photometric time series that exhibit light variations during 22 months of observation. An all-sky classification of common high-amplitude pulsators (Cepheids, long-period variables, Delta Scuti / SX Phoenicis, and RR Lyrae stars) is provided for stars with brightness variations greater than 0.1 mag in the G band. A semi-supervised classification approach was employed, firstly training multi-stage Random Forest classifiers with sources of known types in the literature, followed by a preliminary classification of the Gaia data and a second training phase that included a selection of the first classification results to improve the representation of some classes, before the application of the improved classifiers to the Gaia data. Dedicated validation classifiers were used to reduce the level of contamination in the published results. A relevant fraction of objects were not yet sufficiently sampled for reliable Fourier series decomposition, so classifiers were based on features derived from statistics of photometric time series in the G, BP, and RP bands, as well as from some astrometric parameters. The published classification results include 195,780 RR Lyrae stars, 150,757 long-period variables, 8550 Cepheids, and 8882 Delta Scuti / SX Phoenicis stars. All of these results represent candidates, whose completeness and contamination are described as a function of variability type and classification reliability. Results are expressed in terms of class labels and classification scores, which are available in the vari_classifier_result table of the Gaia archive

    A knowledge, attitudes, and practice survey among obstetrician-gynaecologists on intimate partner violence in Flanders, Belgium

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    BACKGROUND: Intimate partner violence (IPV) has consistently been found to afflict one in twenty pregnant women and is therefore considered a leading cause of physical injury, mental illness and adverse pregnancy outcome. A general antenatal screening policy has been advocated, though compliance with such guidelines tends to be low. We therefore attempted to identify potential barriers to IPV screening in a context where no guidelines have been instigated yet. METHODS: Questionnaire-based Knowledge, Attitude, and Practice survey among obstetrician-gynaecologists in Flanders, Belgium (n = 478). RESULTS: The response rate was 52.1% (249/478). Gynaecologists prove rather unfamiliar with IPV and therefore largely underestimate the extent of the problem. Merely 6.8% (17/249) of the respondents ever received or pursued any kind of education on IPV. Accordingly they do feel insufficiently skilled to deal with IPV, yet sufficiently capable of recognizing IPV among their patients. Survey participants largely refute the incentive of universal screening in favour of opportunistic screening and do not consider pregnancy as a window of opportunity for routine screening. They do consider screening for IPV as an issue of medical liability and therefore do not suffer from a lack of motivation to screen. In addition, obstetrician-gynaecologists do believe that screening for IPV may be an effective means to counteract abusive behaviours. Yet, their outcome expectancy is weighed down by their perceived lack of self-efficacy in dealing with IPV, by lack of familiarity with referral procedures and by their perceived lack of available referral services. Major external or patient-related barriers to IPV screening included a perceived lack of time and fear of offending or insulting patients. Overall, merely 8.4 % (21/245) of gynaecologists in this survey performed some kind of IPV questioning on a regular basis. Finally, physician education was found to be the strongest predictor of a positive attitude towards screening and of current screening practices. CONCLUSION: Endorsement of physician training on IPV is an important first step towards successful implementation of screening guidelines for IPV. Additional introduction of enabling and reinforcement strategies such as screening tools, patient leaflets, formal referral pathways, and physician feedback may further enhance compliance with screening recommendations and guidelines

    Maxillofacial injuries associated with intimate partner violence in women

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    <p>Abstract</p> <p>Background</p> <p>The facial region has been the most common site of injury following violent episodes. The purpose of this study was to determine the prevalence and pattern of maxillofacial injuries associated with intimate partner violence (IPV) in women treated at a single facility in Malaysia.</p> <p>Methods</p> <p>A retrospective review of 242 hospital records of female IPV victims who were seen at the One-Stop Crisis Centre (OSCC) in Hospital Raja Perempuan Zainab II, Kelantan over a two-year period (January 1, 2005 to December 31, 2006) was performed. A structured form was used for data collection. Information regarding the anatomical sites of injuries, types of injuries, and mechanisms of assault were obtained.</p> <p>Results</p> <p>Most victims were married (85.1%), were injured by the husband (83.5%), and had at least one previous IPV episode (85.5%). Injury to the maxillofacial region was the most common (50.4%), followed by injury to the limbs (47.9%). In 122 cases of maxillofacial injuries, the middle of the face was most frequently affected (60.6%), either alone or in combination with the upper or lower third of the face. Injury to soft tissues (contusions, abrasions and lacerations) was the most common (87.7%).</p> <p>Conclusions</p> <p>This study indicates there is a high prevalence of maxillofacial injuries associated with IPV among women treated at the OSCC in Kelantan, Malaysia.</p

    <i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties

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    Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data

    The training needs of Turkish emergency department personnel regarding intimate partner violence

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    <p>Abstract</p> <p>Background</p> <p>Violence against females is a widespread public health problem in Turkey and the lifetime prevalence of IPV ranges between 34 and 58.7%. Health care workers (HCW) sometimes have the unique opportunity and obligation to identify, treat, and educate females who are abused. The objective of this study was to evaluate the knowledge, attitudes, and experiences of the emergency department (ED) staff regarding intimate partner violence (IPV) at a large university hospital in Turkey.</p> <p>Methods</p> <p>A cross-sectional study was conducted in a large university hospital via questionnaire. The study population consisted of all the nurses and physicians who worked in the ED during a two month period (n = 215). The questionnaire response rate was 80.5% (41 nurses and 132 physicians). The main domains of the questionnaire were knowledge regarding the definition of IPV, clinical findings in victims of IPV, legal aspects of IPV, attitudes towards IPV, knowledge about the characteristics of IPV victims and abusers, and professional and personal experiences and training with respect to IPV.</p> <p>Results</p> <p>One-half of the study group were females, 76.3% were physicians, and 89.8% had no training on IPV. The majority of the nurses (89.5%) and physicians (71.1%) declared that they were aware of the clinical appearance of IPV. The mean of the knowledge scores on clinical knowledge were 8.84 ± 1.73 (range, 0–10) for acute conditions, and 4.51 ± 3.32 for chronic conditions. The mean of the knowledge score on legal procedures and the legal rights of the victims was 4.33 ± 1.66 (range, 0–7). At least one reason to justify physical violence was accepted by 69.0% of females and 84.7% of males, but more males than females tended to justify violence (chi square = 5.96; p = 0.015). However, both genders accepted that females who experienced physical violence should seek professional medical help.</p> <p>Conclusion</p> <p>The study participants' knowledge about IPV was rather low and a training program is thus necessary on this issue. Attention must be given to the legal aspects and clinical manifestations of IPV. The training program should also include a module on gender roles in order to improve the attitudes towards IPV.</p

    Male responsibility and maternal morbidity: a cross-sectional study in two Nigerian states

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    <p>Abstract</p> <p>Background</p> <p>Nigeria continues to have high rates of maternal morbidity and mortality. This is partly associated with lack of adequate obstetric care, partly with high risks in pregnancy, including heavy work. We examined actionable risk factors and underlying determinants at community level in Bauchi and Cross River States of Nigeria, including several related to male responsibility in pregnancy.</p> <p>Method</p> <p>In 2009, field teams visited a stratified (urban/rural) last stage random sample of 180 enumeration areas drawn from the most recent censuses in each of Bauchi and Cross River states. A structured questionnaire administered in face-to-face interviews with women aged 15-49 years documented education, income, recent birth history, knowledge and attitudes related to safe birth, and deliveries in the last three years. Closed questions covered female genital mutilation, intimate partner violence (IPV) in the last year, IPV during the last pregnancy, work during the last pregnancy, and support during pregnancy. The outcome was complications in pregnancy and delivery (eclampsia, sepsis, bleeding) among survivors of childbirth in the last three years. We adjusted bivariate and multivariate analysis for clustering.</p> <p>Findings</p> <p>The most consistent and prominent of 28 candidate risk factors and underlying determinants for non-fatal maternal morbidity was intimate partner violence (IPV) during pregnancy (ORa 2.15, 95%CIca 1.43-3.24 in Bauchi and ORa 1.5, 95%CI 1.20-2.03 in Cross River). Other spouse-related factors in the multivariate model included not discussing pregnancy with the spouse and, independently, IPV in the last year. Shortage of food in the last week was a factor in both Bauchi (ORa 1.66, 95%CIca 1.22-2.26) and Cross River (ORa 1.32, 95%CIca 1.15-1.53). Female genital mutilation was a factor among less well to do Bauchi women (ORa 2.1, 95%CIca 1.39-3.17) and all Cross River women (ORa 1.23, 95%CIca 1.1-1.5).</p> <p>Interpretation</p> <p>Enhancing clinical protocols and skills can only benefit women in Nigeria and elsewhere. But the violence women experience throughout their lives – genital mutilation, domestic violence, and steep power gradients – is accentuated through pregnancy and childbirth, when women are most vulnerable. IPV especially in pregnancy, women's fear of husbands or partners and not discussing pregnancy are all within men's capacity to change.</p

    A Systematic Review of African Studies on Intimate Partner Violence against Pregnant Women: Prevalence and Risk Factors

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    Background: Intimate partner violence (IPV) is very high in Africa. However, information obtained from the increasing number of African studies on IPV among pregnant women has not been scientifically analyzed. This paper presents a systematic review summing up the evidence from African studies on IPV prevalence and risk factors among pregnant women. Methods: A key-word defined search of various electronic databases, specific journals and reference lists on IPV prevalence and risk factors during pregnancy resulted in 19 peer-reviewed journal articles which matched our inclusion criteria. Quantitative articles about pregnant women from Africa published in English between 2000 and 2010 were reviewed. At least two reviewers assessed each paper for quality and content. We conducted meta-analysis of prevalence data and reported odds ratios of risk factors. Results: The prevalence of IPV during pregnancy ranges from 2% to 57% (n = 13 studies) with meta-analysis yielding an overall prevalence of 15.23% (95% CI: 14.38 to 16.08%). After adjustment for known confounders, five studies retained significant associations between HIV and IPV during pregnancy (OR1.48-3.10). Five studies demonstrated strong evidence that a history of violence is significantly associated with IPV in pregnancy and alcohol abuse by a partner also increases a woman's chances of being abused during pregnancy (OR 2.89-11.60). Other risk factors include risky sexual behaviours, low socioeconomic status and young age. Conclusion: The prevalence of IPV among pregnant women in Africa is one of the highest reported globally. The major risk factors included HIV infection, history of violence and alcohol and drug use. This evidence points to the importance of further research to both better understand IPV during pregnancy and feed into interventions in reproductive health services to prevent and minimize the impact of such violence
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