Impacts of pure shocks in the BHR71 bipolar outflow

During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks is therefore essential to the study of star formation. We present comparisons of shock models with CO, H2, and SiO observations in a 'pure' shock position in the BHR71 bipolar outflow. These comparisons provide an insight into the shock and pre-shock characteristics, and allow us to understand the energetic and chemical feedback of star formation on Galactic scales. New CO (Jup = 16, 11, 7, 6, 4, 3) observations from the shocked regions with the SOFIA and APEX telescopes are presented and combined with earlier H2 and SiO data (from the Spitzer and APEX telescopes). The integrated intensities are compared to a grid of models that were obtained from a magneto-hydrodynamical shock code which calculates the dynamical and chemical structure of these regions combined with a radiative transfer module based on the 'large velocity gradient' approximation. The CO emission leads us to update the conclusions of our previous shock analysis: pre-shock densities of 1e4 cm-3 and shock velocities around 20-25 km s-1 are still constrained, but older ages are inferred ( 4000 years). We evaluate the contribution of shocks to the excitation of CO around forming stars. The SiO observations are compatible with a scenario where less than 4% of the pre-shock SiO belongs to the grain mantles. We infer outflow parameters: a mass of 1.8x1e-2 Msun was measured in our beam, in which a momentum of 0.4 Msun km s-1 is dissipated, for an energy of 4.2x1e43erg. We analyse the energetics of the outflow species by species. Comparing our results with previous studies highlights their dependence on the method: H2 observations only are not sufficient to evaluate the mass of outflows.Comment: 14 pages, 10 figures, 4 Tables, accepted in A&

Determinants of low birth weight in urban Pakistan

Objective: To identify determinants of low birth weight (LBW) in Karachi, Pakistan, including environmental exposures and nutritional status of the mother during pregnancy. Design: Cross-sectional study. Participants: Five hundred and forty mother-infant pairs. We interviewed mothers about obstetric history, diet and exposure to Pb. We measured birth weight and blood lead level (BLL). We performed multiple log binomial regression analysis to identify factors related to LBW.Results: Of 540 infants, 100 (18.5%) weighed 208.7 mg/d), infants of mothers with MUAC less than or equal to the median and dietary vitamin C intake \u3e 208-7 mg/d (adjPR = 10.80, 95 % CI 1.46, 79.76), mothers with MUAC above the median and vitamin C intak

Mind the gap: Can we explain declining male reproductive health with known antiandrogens?

This article has been made available through the Brunel Open Access Publishing Fund.Several countries have experienced rises in cryptorchidisms, hypospadias and testicular germ cell cancer. The reasons for these trends are largely unknown, but Skakkebaek has proposed that these disorders form a testicular dysgenesis syndrome and can be traced to androgen insufficiency in foetal life. This suggests that antiandrogenic chemicals might contribute to risks, but few chemicals have been linked to these diseases in epidemiological studies. In animal studies with p,p0-dichlorodiphenyldichloroethylene, effects typical of disruptions of male sexual differentiation became apparent when the foetal levels of this androgen receptor (AR) antagonist approached values associated with responses in in vitro assays. This prompted us to analyse whether the 22 chemicals with AR antagonistic properties would produce mixture effects in an in vitro AR antagonism assay when combined at concentrations found in human serum. Other antiandrogenic modalities could not be considered. Two scenarios were investigated, one representative of average serum levels reported in European countries, the other in line with levels towards the high exposures. In both situations, the in vitro potency of the 22 selected AR antagonists was too low to produce combined AR antagonistic effects at the concentrations found in human serum, although the high exposure scenario came quite close to measurable effects. Nevertheless, our analysis exposes an explanation gap which can only be bridged by conjuring up as yet undiscovered high potency AR antagonists or, alternatively, high exposures to unknown agents of average potency

Partner notification for sexually transmitted infections in developing countries: a systematic review

<p>Abstract</p> <p>Background</p> <p>The feasibility and acceptability of partner notification (PN) for sexually transmitted infections (STIs) in developing countries was assessed through a comprehensive literature review, to help identify future intervention needs.</p> <p>Methods</p> <p>The Medline, Embase, and Google Scholar databases were searched to identify studies published between January 1995 and December 2007 on STI PN in developing countries. A systematic review of the research extracted information on: (1) willingness of index patients to notify partners; (2) the proportion of partners notified or referred; (3) client-reported barriers in notifying partners; (4) infrastructure barriers in notifying partners; and (5) PN approaches that were evaluated in developing countries.</p> <p>Results</p> <p>Out of 609 screened articles, 39 met our criteria. PN outcome varied widely and was implemented more often for spousal partners than for casual or commercial partners. Reported barriers included sociocultural factors such as stigma, fear of abuse for having an STI, and infrastructural factors related to the limited number of STD clinics, and trained providers and reliable diagnostic methods. Client-oriented counselling was found to be effective in improving partner referral outcomes.</p> <p>Conclusions</p> <p>STD clinics can improve PN with client-oriented counselling, which should help clients to overcome perceived barriers. The authors speculate that well-designed PN interventions to evaluate the impact on STI prevalence and incidence along with cost-effectiveness components will motivate policy makers in developing countries to allocate more resources towards STI management.</p

Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes

Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs.NovartisEli Lilly and CompanyAstraZenecaAbbViePfizer UKCelgeneEisaiGenentechMerck Sharp and DohmeRocheCancer Research UKGovernment of CanadaArray BioPharmaGenome CanadaNational Institutes of HealthEuropean CommissionMinistère de l'Économie, de l’Innovation et des Exportations du QuébecSeventh Framework ProgrammeCanadian Institutes of Health Researc

Genome-wide association study of germline variants and breast cancer-specific mortality

BACKGROUND: We examined the associations between germline variants and breast cancer mortality using a large meta-analysis of women of European ancestry. METHODS: Meta-analyses included summary estimates based on Cox models of twelve datasets using ~10

Status of children\u27s blood lead levels in Pakistan: Implications for research and policy

Objectives: Data on blood lead levels, sources of lead and health effects were reviewed among children in Pakistan. Methods: A systematic review was conducted of published studies found through PubMed, an index of Pakistani medical journals PakMediNet and unpublished reports from governmental and non-govern mental agencies in Pakistan. Results: With the exception of a few studies that had adequate sample sizes and population-based samples, most studies were small and used convenience sampling methods to select study subjects. Overall, blood lead levels declined from 38 mu g/dl in 1989 to 15 mu g/dl in 2002. The major sources of lead that directly or indirectly resulted in lead exposure of children included: leaded petrol, father\u27s occupation in lead-based industry, leaded paint, traditional cosmetics, and remedies. Apart from leaded petrol, there was no information regarding the [eve[ of lead in other sources such as paints and the household environment. Very little information was available regarding the adverse health effects of lead among children. Conclusion: The phasing out of leaded petrol was a commendable mitigation measure undertaken in July 2001 in Pakistan. A comprehensive assessment is now needed urgently to explore other sources of lead contributing to adverse health effects, and to plan intervention options with the ultimate goal of reducing the burden of disease due to lead exposure