2,182 research outputs found

    Implementation strategies to promote community-engaged efforts to counter tobacco marketing at the point of sale

    Get PDF
    The US tobacco industry spends $8.2 billion annually on marketing at the point of sale (POS), a practice known to increase tobacco use. Evidence-based policy interventions (EBPIs) are available to reduce exposure to POS marketing, and nationwide, states are funding community-based tobacco control partnerships to promote local enactment of these EBPIs. Little is known, however, about what implementation strategies best support community partnerships' success enacting EBPI. Guided by Kingdon's theory of policy change, Counter Tools provides tools, training, and other implementation strategies to support community partnerships' performance of five core policy change processes: document local problem, formulate policy solutions, engage partners, raise awareness of problems and solutions, and persuade decision makers to enact new policy. We assessed Counter Tools' impact at 1 year on (1) partnership coordinators' self-efficacy, (2) partnerships' performance of core policy change processes, (3) community progress toward EBPI enactment, and (4) salient contextual factors. Counter Tools provided implementation strategies to 30 partnerships. Data on self-efficacy were collected using a pre-post survey. Structured interviews assessed performance of core policy change processes. Data also were collected on progress toward EBPI enactment and contextual factors. Analysis included descriptive and bivariate statistics and content analysis. Following 1-year exposure to implementation strategies, coordinators' self-efficacy increased significantly. Partnerships completed the greatest proportion of activities within the “engage partners” and “document local problem” core processes. Communities made only limited progress toward policy enactment. Findings can inform delivery of implementation strategies and tests of their effects on community-level efforts to enact EBPIs

    Multi-Epoch Spectropolarimetry for a Sample of Type IIn Supernovae: Persistent Asymmetry in Dusty Circumstellar Material

    Full text link
    We present multi-epoch spectropolarimetry and spectra for a sample of 14 Type IIn supernovae (SNe IIn). We find that after correcting for likely interstellar polarization, SNe IIn commonly show intrinsic continuum polarization of 1--3% at the time of peak optical luminosity, although a few show weaker or negligible polarization. While some SNe IIn have even stronger polarization at early times, their polarization tends to drop smoothly over several hundred days after peak. We find a tendency for the intrinsic polarization to be stronger at bluer wavelengths, especially at early times. While polarization from an electron scattering region is expected to be grey, scattering of SN light by dusty circumstellar material (CSM) may induce such a wavelength-dependent polarization. For most SNe IIn, changes in polarization degree and wavelength dependence are not accompanied by changes in the position angle, requiring that asymmetric pre-SN mass loss had a persistent geometry. While 2--3% polarization is typical, about 30% of SNe IIn have very low or undetected polarization. Under the simplifying assumption that all SN IIn progenitors have axisymmetric CSM (i.e. disk/torus/bipolar), then the distribution of polarization values we observe is consistent with similarly asymmetric CSM seen from a distribution of random viewing angles. This asymmetry has very important implications for understanding the origin of pre-SN mass loss in SNe IIn, suggesting that it was shaped by binary interaction.Comment: 76 pages, 54 figures (13 in main text, 41 in appendix A

    SN2012ab: A Peculiar Type IIn Supernova with Aspherical Circumstellar Material

    Full text link
    We present photometry, spectra, and spectropolarimetry of supernova (SN) 2012ab, mostly obtained over the course of 300\sim 300 days after discovery. SN 2012ab was a Type IIn (SN IIn) event discovered near the nucleus of spiral galaxy 2MASXJ12224762+0536247. While its light curve resembles that of SN 1998S, its spectral evolution does not. We see indications of CSM interaction in the strong intermediate-width emission features, the high luminosity (peak at absolute magnitude M=19.5M=-19.5), and the lack of broad absorption features in the spectrum. The Hα\alpha emission undergoes a peculiar transition. At early times it shows a broad blue emission wing out to 14,000-14{,}000 km s1\mathrm{s^{-1}} and a truncated red wing. Then at late times (>> 100\,days) it shows a truncated blue wing and a very broad red emission wing out to roughly +20,000+20{,}000 km s1\mathrm{s^{-1}}. This late-time broad red wing probably arises in the reverse shock. Spectra also show an asymmetric intermediate-width Hα\alpha component with stronger emission on the red side at late times. The evolution of the asymmetric profiles requires a density structure in the distant CSM that is highly aspherical. Our spectropolarimetric data also suggest asphericity with a strong continuum polarization of 13\sim 1-3% and depolarization in the Hα\alpha line, indicating asphericity in the CSM at a level comparable to that in other SNe IIn. We estimate a mass-loss rate of M˙=0.050Myr1\dot{M} = 0.050\, {\rm M}_{\odot}\,\mathrm{yr^{-1}} for vpre=100v_{\rm pre} = 100\,km\,s1\mathrm{s^{-1}} extending back at least 75\,yr prior to the SN. The strong departure from axisymmetry in the CSM of SN 2012ab may suggest that the progenitor was an eccentric binary system undergoing eruptive mass loss.Comment: 18 pages, 12 figure

    Spectropolarimetry of SN 2011dh in M51: geometric insights on a Type IIb supernova progenitor and explosion

    Full text link
    We present seven epochs of spectropolarimetry of the Type IIb supernova (SN) 2011dh in M51, spanning 86 days of its evolution. The first epoch was obtained 9 days after the explosion, when the photosphere was still in the depleted hydrogen layer of the stripped-envelope progenitor. Continuum polarization is securely detected at the level of P~0.5% through day 14 and appears to diminish by day 30, which is different from the prevailing trends suggested by studies of other core-collapse SNe. Time-variable modulations in P and position angle are detected across P-Cygni line features. H-alpha and HeI polarization peak after 30 days and exhibit position angles roughly aligned with the earlier continuum, while OI and CaII appear to be geometrically distinct. We discuss several possibilities to explain the evolution of the continuum and line polarization, including the potential effects of a tidally deformed progenitor star, aspherical radioactive heating by fast-rising plumes of Ni-56 from the core, oblique shock breakout, or scattering by circumstellar material. While these possibilities are plausible and guided by theoretical expectations, they are not unique solutions to the data. The construction of more detailed hydrodynamic and radiative-transfer models that incorporate complex aspherical geometries will be required to further elucidate the nature of the polarized radiation from SN 2011dh and other Type IIb supernovae.Comment: Post-proof edit. Accepted to MNRAS 2015 Aug 1

    Longitudinal study of urban malaria in a cohort of Ugandan children: description of study site, census and recruitment

    Get PDF
    BACKGROUND: Studies of malaria in well-defined cohorts offer important data about the epidemiology of this complex disease, but few have been done in urban African populations. To generate a sampling frame for a longitudinal study of malaria incidence and treatment in Kampala, Uganda, a census, mapping and survey project was conducted. METHODS: All households in a geographically defined area were enumerated and mapped. Probability sampling was used to recruit a representative sample of children and collect baseline descriptive data for future longitudinal studies. RESULTS: 16,172 residents living in 4931 households in a densely-populated community (18,824 persons/km(2)) were enumerated. A total of 582 households were approached with at least one child less than 10 years of age in order to recruit 601 children living in 322 households. At enrollment, 19% were parasitaemic, 24% were anaemic, 43% used bednets, and 6% used insecticide-treated nets. Low G6PD activity (OR = 0.33, P = 0.009) and bednet use (OR = 0.64, P = 0.045) were associated with a decreased risk of parasitaemia. Increasing age (OR = 0.62 for each year, P < 0.001) and bednet use (OR = 0.58, P = 0.02) were associated with a decreased risk of anaemia CONCLUSION: Detailed surveys of target populations in urban Africa can provide valuable descriptive data and provide a sampling frame for recruitment of representative cohorts for longitudinal studies. Plans to use a multi-disciplinary approach to improve the understanding of the distribution and determinants of malaria incidence and response to therapy in this population are discussed

    SN2013fs and SN2013fr: Exploring the circumstellar-material diversity in Type II supernovae

    Full text link
    We present photometry and spectroscopy of SN2013fs and SN2013fr in the first 100 days post-explosion. Both objects showed transient, relatively narrow Hα\alpha emission lines characteristic of SNeIIn, but later resembled normal SNeII-P or SNeII-L, indicative of fleeting interaction with circumstellar material (CSM). SN2013fs was discovered within 8hr of explosion. Its light curve exhibits a plateau, with spectra revealing strong CSM interaction at early times. It is a less luminous version of the transitional SNIIn PTF11iqb, further demonstrating a continuum of CSM interaction intensity between SNeII-P and IIn. It requires dense CSM within 6.5×\times1014^{14}~cm of the progenitor, from a phase of advanced pre-SN mass loss shortly before explosion. Spectropolarimetry of SN2013fs shows little continuum polarization, but noticeable line polarization during the plateau phase. SN2013fr morphed from a SNIIn at early times to a SNII-L. After the first epoch its narrow lines probably arose from host-galaxy emission, but the bright, narrow Hα\alpha emission at early times may be intrinsic. As for SN2013fs, this would point to a short-lived phase of strong CSM interaction if proven to be intrinsic, suggesting a continuum between SNeIIn and II-L. It is a low-velocity SNII-L, like SN2009kr but more luminous. SN2013fr also developed an IR excess at later times, due to warm CSM dust that require a more sustained phase of strong pre-SN mass loss.Comment: MNRAS accepted. 28 pages, 23 figures, 8 table

    A Detailed Observational Analysis of V1324 Sco, the Most Gamma-Ray Luminous Classical Nova to Date

    Full text link
    It has recently been discovered that some, if not all, classical novae emit GeV gamma rays during outburst, but the mechanisms involved in the production of the gamma rays are still not well understood. We present here a comprehensive multi-wavelength dataset---from radio to X-rays---for the most gamma-ray luminous classical nova to-date, V1324 Sco. Using this dataset, we show that V1324 Sco is a canonical dusty Fe-II type nova, with a maximum ejecta velocity of 2600 km s1^{-1} and an ejecta mass of few ×105\times 10^{-5} M_{\odot}. There is also evidence for complex shock interactions, including a double-peaked radio light curve which shows high brightness temperatures at early times. To explore why V1324~Sco was so gamma-ray luminous, we present a model of the nova ejecta featuring strong internal shocks, and find that higher gamma-ray luminosities result from higher ejecta velocities and/or mass-loss rates. Comparison of V1324~Sco with other gamma-ray detected novae does not show clear signatures of either, and we conclude that a larger sample of similarly well-observed novae is needed to understand the origin and variation of gamma rays in novae.Comment: 26 pages, 13 figure
    corecore