Characterizing spiral arm and interarm star formation

Interarm star formation contributes significantly to a galaxy's star formation budget, and provides an opportunity to study stellar birthplaces unperturbed by spiral arm dynamics. Using optical integral field spectroscopy of the nearby galaxy NGC 628 with VLT/MUSE, we construct Halpha maps including detailed corrections for dust extinction and stellar absorption to identify 391 HII regions at 35pc resolution over 12 kpc^2. Using tracers sensitive to the underlying gravitational potential, we associate HII regions with either arm (271) or interarm (120) environments. Using our full spectral coverage of each region, we find that most HII region physical properties (luminosity, size, metallicity, ionization parameter) are independent of environment. We calculate the fraction of Halpha luminosity due to the diffuse ionized gas (DIG) background contaminating each HII region, and find the DIG surface brightness to be higher within HII regions compared to the surroundings, and slightly higher within arm HII regions. Use of the temperature sensitive [SII]/Halpha line ratio map instead of the Halpha surface brightness to identify HII region boundaries does not change this result. Using the dust attenuation as a tracer of the gas, we find depletion times consistent with previous work (2 x 10^9 yr) with no differences between the arm and interarm, however this is very sensitive to the DIG correction. Unlike molecular clouds, which can be dynamically affected by the galactic environment, we see fairly consistent HII region properties in both arm and interarm environments. This suggests either a difference in arm star formation and feedback, or a decoupling of dense star forming clumps from the more extended surrounding molecular gas.Comment: 10 pages, 4 figures, 1 table, accepted for publication in Ap

Separate ways: The Mass-Metallicity Relation does not strongly correlate with Star Formation Rate in SDSS-IV MaNGA galaxies

We present the integrated stellar mass-metallicity relation (MZR) for more than 1700 galaxies included in the integral field area SDSS-IV MaNGA survey. The spatially resolved data allow us to determine the metallicity at the same physical scale (effective radius in arcsecs, $\mathrm{R_{eff}}$ ) using a heterogeneous set of ten abundance calibrators. Besides scale factors, the shape of the MZR is similar for all calibrators, consistent with those reported previously using single-fiber and integral field spectroscopy. We compare the residuals of this relation against the star formation rate (SFR) and specific SFR (sSFR). We do not find a strong secondary relation of the MZR with either SFR or the sSFR for any of the calibrators, in contrast with previous single-fiber spectroscopic studies. Our results agree with an scenario in which metal enrichment happens at local scales, with global outflows playing a secondary role in shaping the chemistry of galaxies and cold-gas inflows regulating the stellar formation.Comment: 10 pages, 9 Figures. Accepted for publication in Ap

Human resources for control of tuberculosis and HIV-associated tuberculosis.

The global targets for tuberculosis (TB) control were postponed from 2000 to 2005, but on current evidence a further postponement may be necessary. Of the constraints preventing these targets being met, the primary one appears to be the lack of adequately trained and qualified staff. This paper outlines: 1) the human resources and skills for global TB and human immunodeficiency virus (HIV) TB control, including the human resources for implementing the DOTS strategy, the additional human resources for implementing joint HIV-TB control strategies and what is known about human resource gaps at global level; 2) the attempts to quantify human resource gaps by focusing on a small country in sub-Saharan Africa, Malawi; and 3) the main constraints to human resources and their possible solutions, under six main headings: human resource planning; production of human resources; distribution of the work-force; motivation and staff retention; quality of existing staff; and the effect of HIV/AIDS. We recommend an urgent shift in thinking about the human resource paradigm, and exhort international policy makers and the donor community to make a concerted effort to bridge the current gaps by investing for real change

Why Aren’t There More Maternal Deaths? A Decomposition Analysis

Globally, the number of maternal deaths remains large, and the risk per birth is high in the developing world. Deaths declined between 1990 and 2008, despite the 42% increase in women. We decompose selected determinants to help explain the decline. Numbers of women, births, and fertility rates come from the UN; maternal mortality ratios are from the UN and from Hogan et al. Decomposition isolates the effects of additional women, decreases in fertility, and declines in mortality ratios, also in rates. Women aged 15–49 increased by 42%, but births remained constant due to declining fertility rates. The fertility decline alone averted approximately 1.7 million deaths, 1990–2008. The risk per birth (MMR) also fell, adding to the decline in the number of deaths. Exceptional declines occurred in the maternal mortality rate. Sub-Saharan Africa has experienced minimal declines in deaths, due to increases in women and small declines in fertility and mortality. The growing numbers of women have made international efforts to reduce the number of maternal deaths ever more challenging. Comparatively little attention has been given to the offsetting effect of the historic fertility declines in the developing world, and hence a flat trend in births. The maternal mortality ratio has also fallen, reflecting the success of direct maternal health efforts. Programs that provide couples with the means to control their fertility can reinforce fertility declines. These programs are companions to ongoing, direct measures to reduce the risk of death once pregnant

Vortex distribution in the Lowest Landau Level

We study the vortex distribution of the wave functions minimizing the Gross Pitaevskii energy for a fast rotating condensate in the Lowest Landau Level (LLL): we prove that the minimizer cannot have a finite number of zeroes thus the lattice is infinite, but not uniform. This uses the explicit expression of the projector onto the LLL. We also show that any slow varying envelope function can be approximated in the LLL by distorting the lattice. This is used in particular to approximate the inverted parabola and understand the role of ``invisible'' vortices: the distortion of the lattice is very small in the Thomas Fermi region but quite large outside, where the "invisible" vortices lie.Comment: 4 pages, 1 figur

Asthma on the job: work-related factors in new-onset asthma and in exacerbations of pre-existing asthma

AbstractOccupational asthma (OA) can be defined as variable airways narrowing causally related to exposure in the working environment to airborne dusts, gases, vapours or fumes. There are many agents in the work-place that can induce asthma or cause substantial deterioration in pre-existing asthma. It has been estimated that 5–15% of adult-onset asthma can be attributed to occupational exposures. Hence adult patients, especially those with new-onset asthma, must be investigated with regard to occupational risk factors for disease. The prognosis for OA is improved if the causal exposure is controlled either by controlling the exposure at the workplace or by moving the patient out of the workplace

An international prospective general population-based study of respiratory work disability

Background: Previous cross-sectional studies have shown that job change due to breathing problems at the workplace (respiratory work disability) is common among adults of working age. That research indicated that occupational exposure to gases, dust and fumes was associated with job change due to breathing problems, although causal inferences have been tempered by the cross-sectional nature of previously available data. There is a need for general population-based prospective studies to assess the incidence of respiratory work disability and to delineate better the roles of potential predictors of respiratory work disability.Methods: A prospective general population cohort study was performed in 25 centres in 11 European countries and one centre in the USA. A longitudinal analysis was undertaken of the European Community Respiratory Health Survey including all participants employed at any point since the baseline survey, 6659 subjects randomly sampled and 779 subjects comprising all subjects reporting physician-diagnosed asthma. The main outcome measure was new-onset respiratory work disability, defined as a reported job change during follow-up attributed to breathing problems. Exposure to dusts (biological or mineral), gases or fumes during follow-up was recorded using a job-exposure matrix. Cox proportional hazard regression modelling was used to analyse such exposure as a predictor of time until job change due to breathing problems.Results: The incidence rate of respiratory work disability was 1.2/1000 person-years of observation in the random sample (95% CI 1.0 to 1.5) and 5.7/1000 person-years in the asthma cohort (95% CI 4.1 to 7.8). In the random population sample, as well as in the asthma cohort, high occupational exposure to biological dust, mineral dust or gases or fumes predicted increased risk of respiratory work disability. In the random sample, sex was not associated with increased risk of work disability while, in the asthma cohort, female sex was associated with an increased disability risk (hazard ratio 2.8, 95% CI 1.3 to 5.9).Conclusions: Respiratory work disability is common overall. It is associated with workplace exposures that could be controlled through preventive measures

Proximate determinants of fertility in Ethiopia: comparative analysis of the 2005 and 2011 DHS

Fertility is one of the elements in population dynamics that makes a significant contribution towards changing population size and structure over time. In Ethiopia, for the last 10 years the total fertility rate (TFR) has declined slightly from 5.5 to 4.8 children in 2011. But, the TFR in urban areas has increased from 2.4 to 2.6 per 1000 live births. The Bongaarts model was applied to estimate the indices of the four main proximate determinants of fertility. Bongaarts defines the TFR of a population as a function of the total fecundity rate (TF), index of marriage (Cm), index of contraception (Cc), index of postpartum infecundability (Ci), and index of abortion (Ca); this can be written as TFR = Cm × Cc × Ci × Ca × TF. In 2005, the index of married women in urban areas was lower than rural, but it was unfortunately the same in urban and rural areas in 2011. For the last decade, the index of postpartum infecundability had a great fertility reduction effect compared with the contraception index and marriage index in rural Ethiopia. The lower the four indices of proximate determinants, the more fertility will be reduced. As such, the Ethiopian government, international non-governmental organizations and policy-makers must pay attention to increase the prevalence of contraceptive use and educate society to fight against child marriage. Permanent contraceptive use, such as female sterilization, should be promoted; moreover, legal organizations and the community must work together to raise the legal age of marriage to 18 years.IS