194 research outputs found

    2-Dust : a Dust Radiative Transfer Code for an Axisymmetric System

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    We have developed a general purpose dust radiative transfer code for an axisymmetric system, 2-Dust, motivated by the recent increasing availability of high-resolution images of circumstellar dust shells at various wavelengths. This code solves the equation of radiative transfer following the principle of long characteristic in a 2-D polar grid while considering a 3-D radiation field at each grid point. A solution is sought through an iterative scheme in which self-consistency of the solution is achieved by requiring a global luminosity constancy throughout the shell. The dust opacities are calculated through Mie theory from the given size distribution and optical properties of the dust grains. The main focus of the code is to obtain insights on (1) the global energetics of dust grains in the shell (2) the 2-D projected morphologies that are strongly dependent on the mixed effects of the axisymmetric dust distribution and inclination angle of the shell. Here, test models are presented with discussion of the results. The code can be supplied with a user-defined density distribution function, and thus, is applicable to a variety of dusty astronomical objects possessing the axisymmetric geometry.Comment: To be published in ApJ, April 2003 issue; 13 pages, 4 tables, 17 figures, 5-page appendix (no figures for the main text included in this preprint). For the complete preprint and code distribution, contact the author

    Effects of antiplatelet therapy on menstrual blood loss in reproductive-aged women:a systematic review

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    Background: The effects of antiplatelet therapy on menstrual bleeding have not been well characterized. Objectives: To systematically review the effects of antiplatelet therapy on menstrual bleeding. Methods: A literature search was performed for studies of reproductive-aged women who received antiplatelet therapy. Characteristics of menstrual bleeding both before and after initiation of antiplatelet therapy and from comparison groups were collected. Two reviewers independently assessed the risk of bias in individual studies. Results: Thirteen studies with a total of 611 women who received antiplatelet therapy were included. Types of antiplatelet drugs used were aspirin (n = 8), aspirin and/or clopidogrel (n = 2), prasugrel (n = 1), and not specified (n = 2). Risk of bias was assessed at moderate (n = 1), serious (n = 8), critical (n = 2), and no information (n = 2). Three studies reported changes in menstrual blood loss volume. One of these showed no increase during antiplatelet therapy; the other 2 studies suggested that aspirin may increase menstrual blood loss volume. In 3 studies that assessed the duration of menstrual bleeding, up to 13% of women reported an increased duration of menstruation. In 5 studies that reported the intensity of menstrual flow, 13% to 38% of women experienced an increase in the intensity of flow. Five studies reported the prevalence of heavy menstrual bleeding in women who received antiplatelet therapy, with estimates ranging from 7% to 38%. Conclusion: There is lack of high-quality data on the effects of antiplatelet therapy on menstrual bleeding. Aspirin may increase menstrual blood loss, at least in a minority of women, whereas the effects of P2Y12 inhibitors are unknown.</p

    Effects of antiplatelet therapy on menstrual blood loss in reproductive-aged women:a systematic review

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    Background: The effects of antiplatelet therapy on menstrual bleeding have not been well characterized. Objectives: To systematically review the effects of antiplatelet therapy on menstrual bleeding. Methods: A literature search was performed for studies of reproductive-aged women who received antiplatelet therapy. Characteristics of menstrual bleeding both before and after initiation of antiplatelet therapy and from comparison groups were collected. Two reviewers independently assessed the risk of bias in individual studies. Results: Thirteen studies with a total of 611 women who received antiplatelet therapy were included. Types of antiplatelet drugs used were aspirin (n = 8), aspirin and/or clopidogrel (n = 2), prasugrel (n = 1), and not specified (n = 2). Risk of bias was assessed at moderate (n = 1), serious (n = 8), critical (n = 2), and no information (n = 2). Three studies reported changes in menstrual blood loss volume. One of these showed no increase during antiplatelet therapy; the other 2 studies suggested that aspirin may increase menstrual blood loss volume. In 3 studies that assessed the duration of menstrual bleeding, up to 13% of women reported an increased duration of menstruation. In 5 studies that reported the intensity of menstrual flow, 13% to 38% of women experienced an increase in the intensity of flow. Five studies reported the prevalence of heavy menstrual bleeding in women who received antiplatelet therapy, with estimates ranging from 7% to 38%. Conclusion: There is lack of high-quality data on the effects of antiplatelet therapy on menstrual bleeding. Aspirin may increase menstrual blood loss, at least in a minority of women, whereas the effects of P2Y12 inhibitors are unknown.</p

    Scattering by Interstellar Dust Grains: Optical and Ultraviolet

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    Scattering and absorption properties at optical and ultraviolet wavelengths are calculated for an interstellar dust model consisting of carbonaceous grains and amorphous silicate grains. Polarization as a function of scattering angle is calculated for selected wavelengths from the IR to the vacuum UV. The widely-used Henyey-Greenstein phase function provides a good approximation for the scattering phase function between ~0.4 and 1 micron, but fails to fit the calculated phase functions at shorter wavelengths and longer wavelengths. A new analytic phase function is presented. It is exact at long wavelengths, and provides a good fit to the numerically-calculated phase function for lambda > 0.27um. Observational determinations of the scattering albedo and show considerable disagreement, especially in the ultraviolet. Possible reasons for this are discussed.Comment: ApJ, accepted. 19 pages, 10 figures. This version includes a new analytic scattering phase function which is an improvement on the Henyey-Greenstein phase function. Sections on X-ray scattering in previous version of this astro-ph submission have been relocated to a separate paper (Draine 2003: astro-ph/0308251

    Confidential enquiry into maternal deaths in the Netherlands, 2006-2018

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    Introduction To calculate the maternal mortality ratio (MMR) for 2006-2018 in the Netherlands and compare this with 1993-2005, and to describe women's characteristics, causes of death and improvable factors. Material and Methods We performed a nationwide, cohort study of all maternal deaths between January 1, 2006 and December 31, 2018 reported to the Audit Committee Maternal Mortality and Morbidity. Main outcome measures were the national MMR and causes of death. Results Overall MMR was 6.2 per 100 000 live births, a decrease from 12.1 in 1993-2005 (risk ratio [RR] 0.5). Women with a non-western ethnic background had an increased MMR compared with Dutch women (MMR 6.5 vs. 5.0, RR 1.3). The MMR was increased among women with a background from Surinam/Dutch Antilles (MMR 14.7, RR 2.9). Half of all women had an uncomplicated medical history (79/161, 49.1%). Of 171 pregnancy-related deaths within 1 year postpartum, 102 (60%) had a direct and 69 (40%) an indirect cause of death. Leading causes within 42 days postpartum were cardiac disease (n = 21, 14.9%), hypertensive disorders (n = 20, 14.2%) and thrombosis (n = 19, 13.5%). Up to 1 year postpartum, the most common cause of death was cardiac disease (n = 32, 18.7%). Improvable care factors were identified in 76 (47.5%) of all deaths. Conclusions Maternal mortality halved in 2006-2018 compared with 1993-2005. Cardiac disease became the main cause. In almost half of all deaths, improvable factors were identified and women with a background from Surinam/Dutch Antilles had a threefold increased risk of death compared with Dutch women without a background of migration

    ‘Do i care?’ young adults' recalled experiences of early adolescent overweight and obesity: a qualitative study

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    &lt;p&gt;Objective: Individual behaviour change to reduce obesity requires awareness of, and concern about, weight. This paper therefore describes how young adults, known to have been overweight or obese during early adolescence, recalled early adolescent weight-related awareness and concerns. Associations between recalled concerns and weight-, health- and peer-related survey responses collected during adolescence are also examined.&lt;/p&gt; &lt;p&gt;Design: Qualitative semi-structured interviews with young adults; data compared with responses to self-report questionnaires obtained in adolescence.&lt;/p&gt; &lt;p&gt;Participants: A total of 35 participants, purposively sub-sampled at age 24 from a longitudinal study of a school year cohort, previously surveyed at ages 11, 13 and 15. Physical measures during previous surveys allowed identification of participants with a body mass index (BMI) indicative of overweight or obesity (based on British 1990 growth reference) during early adolescence. Overall, 26 had been obese, of whom 11 had BMI99.6th centile, whereas 9 had been overweight (BMI=95th–97.9th centile).&lt;/p&gt; &lt;p&gt;Measures: Qualitative interview responses describing teenage life, with prompts for school-, social- and health-related concerns. Early adolescent self-report questionnaire data on weight-worries, self-esteem, friends and victimisation (closed questions).&lt;/p&gt; &lt;p&gt;Results: Most, but not all recalled having been aware of their overweight. None referred to themselves as having been obese. None recalled weight-related health worries. Recollection of early adolescent obesity varied from major concerns impacting on much of an individual's life to almost no concern, with little relation to actual severity of overweight. Recalled concerns were not clearly patterned by gender, but young adult males recalling concerns had previously reported more worries about weight, lower self-esteem, fewer friends and more victimisation in early adolescence; no such pattern was seen among females. Conclusion: The popular image of the unhappy overweight teenager was not borne out. Many obese adolescents, although well aware of their overweight recalled neither major dissatisfaction nor concern. Weight-reduction behaviours are unlikely in such circumstances.&lt;/p&gt

    Воспитание толерантности в процессе преподавания гуманитарных дисциплин

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    Objective: To assess whether patient characteristics add to the fetal fibronectin test and cervical length measurement in the prediction of preterm delivery in symptomatic women. Study design: A nationwide prospective cohort study was conducted in all ten perinatal centres in the Netherlands. Women with symptoms of preterm labour between 24 and 34 weeks gestation with intact membranes were invited. In all women qualitative fibronectin testing (0.050 tig/mL cut-off) and cervical length measurement were performed. Only singleton pregnancies were included in this analysis. Logistic regression was used to construct two multivariable models to predict spontaneously delivery within 7 days: a model including cervical length and fetal fibronectin as predictors, and an extended model including all potential predictors. The models were internally validated using bootstrapping techniques. Predictive performances were assessed as the area under the receiver operator characteristic curve (AUC) and calibration plots. We compared the models' capability to identify women with a low risk to deliver within 7 days. A risk less than 5%, corresponding to the risk for women with a cervical length of at least 25 mm, was considered as low risk. Results: Seventy-three of 600 included women (12%) had delivered spontaneously within 7 days. The extended model included maternal age, parity, previous preterm delivery, vaginal bleeding, C-reactive protein, cervical length, dilatation and fibronectin status. Both models had high discriminative performances (AUC of 0.92 (95% CI 0.88-0.95) and 0.95 (95% CI 0.92-0.97) respectively). Compared to the model with fibronectin and cervical length, our extended model reclassified 38 women (6%) from low risk to high risk and 21 women (4%) from high risk to low risk. Preterm delivery within 7 days occurred once in both the reclassification groups. Conclusion: In women with symptoms of preterm labour before 34 weeks gestation, a model that integrates maternal characteristics, clinical signs and laboratory tests, did not predict delivery within 7 days better than a model with only fibronectin and cervical length. (C) 2015 Elsevier Ireland Ltd. All rights reserved

    Роль страдающей депрессией матери в развитии личности ребенка

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    С позиций психодинамического подхода показана роль страдающей депрессией матери в формировании личности ребенка на первых этапах его постнатального развития и ее влияние на его психическое здоровье в дальнейшем.The role of the mother with depression in development of the child's personality at the first stages of the postnatal period as well as its influence on his/her mental state in future are shown from the perspective of a psychodynamic approach

    Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

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    Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries

    Wolbachia in the flesh: symbiont intensities in germ-line and somatic tissues challenge the conventional view of Wolbachia transmission routes

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    Symbionts can substantially affect the evolution and ecology of their hosts. The investigation of the tissue-specific distribution of symbionts (tissue tropism) can provide important insight into host-symbiont interactions. Among other things, it can help to discern the importance of specific transmission routes and potential phenotypic effects. The intracellular bacterial symbiont Wolbachia has been described as the greatest ever panzootic, due to the wide array of arthropods that it infects. Being primarily vertically transmitted, it is expected that the transmission of Wolbachia would be enhanced by focusing infection in the reproductive tissues. In social insect hosts, this tropism would logically extend to reproductive rather than sterile castes, since the latter constitute a dead-end for vertically transmission. Here, we show that Wolbachia are not focused on reproductive tissues of eusocial insects, and that non-reproductive tissues of queens and workers of the ant Acromyrmex echinatior, harbour substantial infections. In particular, the comparatively high intensities of Wolbachia in the haemolymph, fat body, and faeces, suggest potential for horizontal transmission via parasitoids and the faecal-oral route, or a role for Wolbachia modulating the immune response of this host. It may be that somatic tissues and castes are not the evolutionary dead-end for Wolbachia that is commonly thought
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