715 research outputs found
Parallax and Kinematics of PSR B0919+06 from VLBA Astrometry and Interstellar Scintillometry
Results are presented from a long-term astrometry program on PSR B0919+06
using the NRAO Very Long Baseline Array. With ten observations (seven epochs)
between 1994--2000, we measure a proper motion of 18.35 +/- 0.06 mas/yr in RA,
86.56 +/- 0.12 mas/yr in Dec, and a parallax of 0.83 +/- 0.13 mas (68%
confidence intervals). This yields a pulsar distance of 1.21 +/- 0.19 kpc,
making PSR B0919+06 the farthest pulsar for which a trigonometric parallax has
been obtained, and the implied pulsar transverse speed is 505 +/- 80 km/s.
Combining the distance estimate with interstellar scintillation data spanning
20 years, we infer the existence of a patchy or clumpy scattering screen along
the line of sight in addition to the distributed electron density predicted by
models for the Galaxy, and constrain the location of this scattering region to
within about 250 parsecs of the Sun. Comparison with the lines of sight towards
other pulsars in the same quadrant of the Galaxy permits refinement of our
knowledge of the local interstellar matter in this direction.Comment: 12 pages, includes 4 figures and 3 tables, uses AASTeX 5 (included);
ApJ submitte
Factors influencing women's decisions to drink alcohol during pregnancy: Findings of a qualitative study with implications for health communication
© 2014 Meurk et al.; licensee BioMed Central Ltd. Background: Despite Australian guidelines advising abstinence from alcohol during pregnancy, a relatively high number of Australian women continue to drink alcohol while pregnant. While some call for greater advocacy of the need for abstinence, others have expressed concern that abstinence messages may be harmful to pregnant women and their unborn babies due to the anxiety they could provoke. We present findings on women's deliberations over drinking alcohol during pregnancy, particularly their emotional dimensions, to inform debates about public health messages and practitioner-patient discussions regarding alcohol use during pregnancy.Methods: Semi-structured face-to-face interviews were conducted with 40 women in their homes. Our sample comprised women aged 34-39, drawn from the Australian Longitudinal Study on Women's Health, living in the Greater Brisbane Area who were pregnant, or had recently given birth, in 2009. An inductive qualitative framework analysis approach was used to identify and interpret themes explaining why pregnant women choose to drink or not.Results: Women generally described drinking small amounts of alcohol during pregnancy as being a low risk activity and talked about the importance of alcohol to their social lives as a reason for continuing to drink or finding abstinence a burden; sensitisation to the judgements of others was not widespread. Women predominantly assessed the risk of their drinking in terms of the kinds of alcoholic beverages consumed rather than alcohol content. In reflecting on the advice they recalled receiving, women described their healthcare practitioners as being relaxed about the risks of alcohol consumption.Conclusions: The significance of alcohol to women's identity appeared to be an important reason for continued alcohol use during pregnancy among otherwise risk averse women. Anxiety about alcohol consumption during pregnancy was not widespread. However, obstetricians were an important mediator of this. Health messages that dispel the notion that wine is a " healthy" choice of alcoholic beverage, that provide women with strategies to help them avoid drinking, that advise the broader public not to pressure women to drink if they do not want to, and educate women about the effects of ethanol on maternal and fetal bodies, should be considered
A longitudinal study of the bi-directional relationship between tobacco smoking and psychological distress in a community sample of young Australian women
Background. Tobacco smoking and poor mental health are both prevalent and detrimental health problems in young women. The temporal relationship between the two variables is unclear. We investigated the prospective bidirectional relationship between smoking and mental health over 13 years
The Supernova Remnant G296.7-0.9 in X-rays
Aims: We present a detailed study of the supernova remnant (SNR) G296.7-0.9
in the 0.2-12 keV X-ray band.
Methods: Using data from XMM-Newton we performed a spectro-imaging analysis
of G296.7-0.9 in order to deduce the basic parameters of the remnant and to
search for evidence of a young neutron star associated with it.
Results: In X-rays the remnant is characterized by a bright arc located in
the south-west direction. Its X-ray spectrum can best be described by an
absorbed non-equilibrium collisional plasma model with a hydrogen density of
N_H=1.24_{-0.05}^{+0.07} x 10^{22} cm^{-2} and a plasma temperature of
6.2^{+0.9}_{-0.8} million Kelvin. The analysis revealed a remnant age of 5800
to 7600 years and a distance of 9.8_{-0.7}^{+1.1} kpc. The latter suggests a
spatial connection with a close-by HII region. We did not find evidence for a
young neutron star associated with the remnant.Comment: accepted by A&A, 5 pages, 2 figure
The Backgrounds Data Center
The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible
A research concept for the development of alternatives to slash-and-burn agriculture in the Eastern Amazon region.
Editado por Reinhard Lieberei, Helmut Bianchi, Vera Boehm, Christoph Reisdorff
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