4,506 research outputs found

    Mid-Infrared diagnostics of metal-rich HII regions from VLT and Spitzer Spectroscopy of Young Massive Stars in W31

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    We present near-IR VLT/ISAAC and mid-IR Spitzer/IRS spectroscopy of the young massive cluster in the W31 star-forming region. H-band spectroscopy provides refined classifications for four cluster members O stars with respect to Blum et al. In addition, photospheric features are detected in the massive Young Stellar Object (mYSO) #26. Spectroscopy permits estimates of stellar temperatures and masses, from which a cluster age of ~0.6 Myr and distance of 3.3 kpc are obtained, in excellent agreement with Blum et al. IRS spectroscopy reveals mid-infrared fine structure line fluxes of [Ne II-III] and [S III-IV] for four O stars and five mYSOs. In common with previous studies, stellar temperatures of individual stars are severely underestimated from the observed ratios of fine-structure lines, despite the use of contemporary stellar atmosphere and photoionization models. We construct empirical temperature calibrations based upon the W31 cluster stars of known spectral type, supplemented by two inner Milky Way ultracompact (UC) HII regions whose ionizing star properties are established. Calibrations involving [NeIII] 15.5um/[NeII] 12.8um, [SIV] 10.5um/[NeII] 12.8um or [ArIII] 9.0um/[NeII] 12.8um have application in deducing the spectral types of early- to mid- O stars for other inner Milky Way compact and UCHII regions. Finally, evolutionary phases and timescales for the massive stellar content in W31 are discussed, due to the presence of numerous young massive stars at different formation phases in a `coeval' cluster.Comment: 16 pages, 13 figures, accepted for MNRA

    NMR CAPIBarA: proof of principle of a low-field unilateral magnetic resonance system for monitoring of the placenta during pregnancy

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    A growing body of literature shows that the transverse relaxation times of the placenta change during pregnancy and may be an early indicator of disease. Magnetic resonance imaging (MRI) of pregnant women is not, however, currently used frequently despite this evidence. One significant barrier to adoption is the cost of undertaking an MRI scan and the over utilization of existing equipment. Low-field nuclear magnetic resonance (NMR) offers a low-cost alternative, capable of measuring transverse relaxation in a single point in space. Ultrasound imaging (US) is routinely used at several points during pregnancy but is not capable of early detection of pre-eclampsia, for example. It does, however, provide a technique that is capable of locating the placenta with ease. In combination with a single point low-field measurement, localised with ultrasound imaging allows access to this exciting technique without the need for an expensive traditional MRI. In this work, we present a unilateral system (NMR CAPIBarA), operating at a magnetic field of only 18mT, which measures transverse relaxation times at distances from its surface equivalent to the positioning of a human placenta. Data are presented to characterise the system using relation time standards covering the full transverse relaxation time range relevant for the developing placenta, which are also measured on a 1.5 T clinical MRI scanner

    Startup of the High-Intensity Ultracold Neutron Source at the Paul Scherrer Institute

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    Ultracold neutrons (UCN) can be stored in suitable bottles and observed for several hundreds of seconds. Therefore UCN can be used to study in detail the fundamental properties of the neutron. A new user facility providing ultracold neutrons for fundamental physics research has been constructed at the Paul Scherrer Institute, the PSI UCN source. Assembly of the facility finished in December 2010 with the first production of ultracold neutrons. Operation approval was received in June 2011. We give an overview of the source and the status at startup.Comment: Proceedings of the International Conference on Exotic Atoms and Related Topics - EXA2011 September 5-9, 2011 Austrian Academy of Sciences, Theatersaal, Sonnenfelsgasse 19, 1010 Wien, Austria 6 pages, 3 figure

    Methods of classification for women undergoing induction of labour: a systematic review and novel classification system

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    OBJECTIVE To develop and demonstrate the applicability of a classification system for induction of labour (IOL) that fulfils recognised classification system attributes for clinical, surveillance and research purposes. DESIGN Proof of concept. SETTING, POPULATION Applicability demonstrated in a population cohort of 909,702 maternities in New South Wales, Australia, 2002-2011. METHODS A multidisciplinary collaboration developed a classification system through a systematic literature review, development of a clinically logical model, and presentation to stakeholders for feedback and refinement. Classification factors included parity (nulliparous, parous), previous caesarean section (CS), gestational age (≀36, 37-38, 39-40, ≄41 weeks gestation), number (singleton, multiple) and presentation of the fetus (cephalic, non-cephalic). We determined: the size of each classification group, the contribution each group made to overall IOL rates, and within-group IOL rates (calculated as proportions of all maternities, all maternities excluding prelabour CS and of all continuing maternities). MAIN OUTCOME MEASURES Applicability of IOL classification using routinely collected obstetric data. RESULTS A 10 group classification system was developed. Of all maternities, 25.4% were induced. Nulliparous and parous women without a prior CS at 39-40 weeks gestation with a singleton cephalic-presenting fetus were the largest groups (21.2% and 24.5% respectively) and accounted for the highest proportion of all IOL (20.7% and 21.5% respectively). The highest within group IOL rates were for nullipara (53.8%) and multipara (45.5%) ≄41 weeks gestation. CONCLUSION We propose a classification system for IOL that has the attributes of simplicity and clarity, utilises information that is readily and reliably collected and reported, and enables standard characterisation of populations of women having an IOL.NHMRC 1021025, ARC FT12010006

    Intermittent aeration to improve wastewater treatment efficiency in pilot-scale constructed wetland

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    Forced aeration of horizontal subsurface flow constructed wetlands (HSSF CWs) is nowadays a recognized method to improve treatment efficiency, mainly in terms of ammonium removal. While numerous investigations have been reported testing constant aeration, scarce information can be found about the efficiency of intermittent aeration. This study aims at comparing continuous and intermittent aeration, establishing if there is an optimal regime that will increase treatment efficiency of HSSF CWs whilst minimizing the energy requirement. Full and intermittent aeration were tested in a pilot plant of three HSSF CWs (2.64 m2 each) fed with primary treated wastewater. One unit was fully aerated; one intermittently aerated (i.e. by setting a limit of 0.5 mg/L dissolved oxygen within the bed) with the remaining unit not aerated as a control. Results indicated that intermittent aeration was the most successful operating method. Indeed, the coexistence of aerobic and anoxic conditions promoted by the intermittent aeration resulted in the highest COD (66%), ammonium (99%) and total nitrogen (79%) removals. On the other hand, continuous aeration promotes ammonium removal (99%), but resulted in nitrate concentrations in the effluent of up to 27 mg/L. This study demonstrates the high potential of the intermittent aeration to increase wastewater treatment efficiency of CWs providing an extreme benefit in terms of the energy consumption

    Population-genomic insights into emergence, crop-adaptation, and dissemination of Pseudomonas syringae pathogens

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Many bacterial pathogens are well characterized but, in some cases, relatively little is known about the populations from which they emerged. This limits understanding of the molecular mechanisms underlying disease. The crop pathogen Pseudomonas syringae sensu lato has been widely isolated from the environment, including wild plants and components of the water cycle, and causes disease in several economically important crops. Here, we compared genome sequences of 45 P. syringae crop pathogen outbreak strains with 69 closely related environmental isolates. Phylogenetic reconstruction revealed that crop pathogens emerged many times independently from environmental populations. Unexpectedly, differences in gene content between environmental populations and outbreak strains were minimal with most virulence genes present in both. However, a genome-wide association study identified a small number of genes, including the type III effector genes hopQ1 and hopD1, to be associated with crop pathogens, but not with environmental populations, suggesting that this small group of genes may play an important role in crop disease emergence. Intriguingly, genome-wide analysis of homologous recombination revealed that the locus Psyr 0346, predicted to encode a protein that confers antibiotic resistance, has been frequently exchanged among lineages and thus may contribute to pathogen fitness. Finally, we found that isolates from diseased crops and from components of the water cycle, collected during the same crop disease epidemic, form a single population. This provides the strongest evidence yet that precipitation and irrigation water are an overlooked inoculum source for disease epidemics caused by P. syringae.Caroline L. Monteil received support from INRA and the European Union, in the framework of the Marie-Curie FP7 COFUND People Programme, through the award of an AgreenSkills’ fellowship (under grant agreement n° 267196). Research in Boris A. Vinatzer’s laboratory and genome sequencing was funded by the National Science Foundation of the USA (grants IOS-1354215 and DEB-1241068). Funding for work in the Vinatzer laboratory was also provided in part by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture, U.S. Department of Agriculture. Work carried out in the Sheppard laboratory was supported by the Medical Research Council (MRC) grant MR/L015080/1, and the Wellcome Trust grant 088786/C/09/Z. GM was supported by a NISCHR Health Research Fellowship (HF-14-13)

    Carboxyhaemoglobin levels and their determinants in older British men

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    Background: Although there has been concern about the levels of carbon monoxide exposure, particularly among older people, little is known about COHb levels and their determinants in the general population. We examined these issues in a study of older British men.Methods: Cross-sectional study of 4252 men aged 60-79 years selected from one socially representative general practice in each of 24 British towns and who attended for examination between 1998 and 2000. Blood samples were measured for COHb and information on social, household and individual factors assessed by questionnaire. Analyses were based on 3603 men measured in or close to (< 10 miles) their place of residence.Results: The COHb distribution was positively skewed. Geometric mean COHb level was 0.46% and the median 0.50%; 9.2% of men had a COHb level of 2.5% or more and 0.1% of subjects had a level of 7.5% or more. Factors which were independently related to mean COHb level included season (highest in autumn and winter), region (highest in Northern England), gas cooking (slight increase) and central heating (slight decrease) and active smoking, the strongest determinant. Mean COHb levels were more than ten times greater in men smoking more than 20 cigarettes a day (3.29%) compared with non-smokers (0.32%); almost all subjects with COHb levels of 2.5% and above were smokers (93%). Pipe and cigar smoking was associated with more modest increases in COHb level. Passive cigarette smoking exposure had no independent association with COHb after adjustment for other factors. Active smoking accounted for 41% of variance in COHb level and all factors together for 47%.Conclusion: An appreciable proportion of men have COHb levels of 2.5% or more at which symptomatic effects may occur, though very high levels are uncommon. The results confirm that smoking (particularly cigarette smoking) is the dominant influence on COHb levels

    Haptic guidance improves the visuo-manual tracking of trajectories

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    BACKGROUND: Learning to perform new movements is usually achieved by following visual demonstrations. Haptic guidance by a force feedback device is a recent and original technology which provides additional proprioceptive cues during visuo-motor learning tasks. The effects of two types of haptic guidances-control in position (HGP) or in force (HGF)-on visuo-manual tracking ("following") of trajectories are still under debate. METHODOLOGY/PRINCIPALS FINDINGS: Three training techniques of haptic guidance (HGP, HGF or control condition, NHG, without haptic guidance) were evaluated in two experiments. Movements produced by adults were assessed in terms of shapes (dynamic time warping) and kinematics criteria (number of velocity peaks and mean velocity) before and after the training sessions. CONCLUSION/SIGNIFICANCE: These results show that the addition of haptic information, probably encoded in force coordinates, play a crucial role on the visuo-manual tracking of new trajectories

    Alcohol Production as an Adaptive Livelihood Strategy for Women Farmers in Tanzania and Its Potential for Unintended Consequences on Women's Reproductive Health.

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    Although women occupy a central position in agriculture in many developing countries, they face numerous constraints to achieving their full potential including unequal access to assets and limited decision-making authority. We explore the intersection of agricultural livelihoods, food and economic security, and women's sexual and reproductive health in Iringa Region, Tanzania. Our goal was to understand whether the benefits of supporting women in the agricultural sector might also extend to more distal outcomes, including sexual and reproductive health. Using the Sustainable Livelihoods Framework to guide data collection, we conducted 13 focus group discussions (FGD) with female (n = 11) and male farmers (n = 2) and 20 in-depth interviews with agricultural extension officers (n = 10) and village agro-dealers (n = 10). Despite providing the majority of agricultural labor, women have limited control over land and earned income and have little bargaining power. In response to these constraints, women adopt adaptive livelihood strategies, such as alcohol production, that allow them to retain control over income and support their households. However, women's central role in alcohol production, in concert with the ubiquitous nature of alcohol consumption, places them at risk by enhancing their vulnerability to unsafe or transactional sex. This represents a dangerous confluence of risk for female farmers, in which alcohol plays an important role in income generation and also facilitates high-risk sexual behavior. Alcohol production and consumption has the potential to both directly and indirectly place women at risk for undesirable sexual and reproductive health outcomes. Group formation, better access to finance, and engaging with agricultural extension officers were identified as potential interventions for supporting women farmers and challenging harmful gender norms. In addition, joint, multi-sectoral approaches from health and agriculture and alternative income-generating strategies for women might better address the complexities of achieving safe and sustainable livelihoods for women in this context
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