117 research outputs found

    Hemp a war crop for Iowa

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    Hemp is an annual crop grown for the production of fiber. It is sown in the spring like small grain and produces a thick stand of slender unbranched stalks, growing usually to a height of 6 to 10 feet. The fiber is found extending the length of the stalk, between the thin bark on the outside and the woody central pith on the inside. To obtain, the fiber the stalks are retted (partially decomposed) and then put through machines that separate the fiber from the rest of the stalk. Although hemp has been grown in the United States since early colonial days the acreage of this crop has not been very extensive. Due primarily to competition from cotton, jute, sisal and abaca (Manila fiber) domestic hemp production declined until a low of 1,200 acres was reached in 1933. Since 1939, because of the stimulation of an increased demand due to war conditions, production has again increased. In 1942 there were about 7,500 acres grown for fiber in Wisconsin, 5,000 in Kentucky, 600 in Minnesota and 500 in Illinois

    The EDGE-CALIFA Survey: Evidence for Pervasive Extraplanar Diffuse Ionized Gas in Nearby Edge-On Galaxies

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    We investigate the prevalence, properties, and kinematics of extraplanar diffuse ionized gas (eDIG) in a sample of 25 edge-on galaxies selected from the CALIFA survey. We measure ionized gas scale heights from Hα{\rm H\alpha} and find that 90% have measurable scale heights with a median of 0.8−0.4+0.70.8^{+0.7}_{-0.4} kpc. From the Hα{\rm H\alpha} kinematics, we find that 60% of galaxies show a decrease in the rotation velocity as a function of height above the midplane. This lag is characteristic of eDIG, and we measure a median lag of 21 km s−1^{-1} kpc−1^{-1} which is comparable to lags measured in the literature. We also investigate variations in the lag with radius. HI\rm H{\small I} lags have been reported to systematically decrease with galactocentric radius. We find both increasing and decreasing ionized gas lags with radius, as well as a large number of galaxies consistent with no radial lag variation, and investigate these results in the context of internal and external origins for the lagging ionized gas. We confirm that the [SII]{\rm [S{\small II}]}/Hα{\rm H\alpha} and [NII]{\rm [N{\small II}]}/Hα{\rm H\alpha} line ratios increase with height above the midplane as is characteristic of eDIG. The ionization of the eDIG is dominated by star-forming complexes (leaky HII{\rm H{\small II}} regions). We conclude that the lagging ionized gas is turbulent ejected gas likely resulting from star formation activity in the disk as opposed to gas in the stellar thick disk or bulge. This is further evidence for the eDIG being a product of stellar feedback and for the pervasiveness of this WIM-like phase in many local star-forming galaxies.Comment: 36 pages (including 13 appendix pages), 17 figures, resubmitted to ApJ after one round of refereein

    Effectiveness and cost-effectiveness of an educational intervention for practice teams to deliver problem focused therapy for insomnia: rationale and design of a pilot cluster randomised trial

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    Background: Sleep problems are common, affecting over a third of adults in the United Kingdom and leading to reduced productivity and impaired health-related quality of life. Many of those whose lives are affected seek medical help from primary care. Drug treatment is ineffective long term. Psychological methods for managing sleep problems, including cognitive behavioural therapy for insomnia (CBTi) have been shown to be effective and cost effective but have not been widely implemented or evaluated in a general practice setting where they are most likely to be needed and most appropriately delivered. This paper outlines the protocol for a pilot study designed to evaluate the effectiveness and cost-effectiveness of an educational intervention for general practitioners, primary care nurses and other members of the primary care team to deliver problem focused therapy to adult patients presenting with sleep problems due to lifestyle causes, pain or mild to moderate depression or anxiety. Methods and design: This will be a pilot cluster randomised controlled trial of a complex intervention. General practices will be randomised to an educational intervention for problem focused therapy which includes a consultation approach comprising careful assessment (using assessment of secondary causes, sleep diaries and severity) and use of modified CBTi for insomnia in the consultation compared with usual care (general advice on sleep hygiene and pharmacotherapy with hypnotic drugs). Clinicians randomised to the intervention will receive an educational intervention (2 × 2 hours) to implement a complex intervention of problem focused therapy. Clinicians randomised to the control group will receive reinforcement of usual care with sleep hygiene advice. Outcomes will be assessed via self-completion questionnaires and telephone interviews of patients and staff as well as clinical records for interventions and prescribing. Discussion: Previous studies in adults have shown that psychological treatments for insomnia administered by specialist nurses to groups of patients can be effective within a primary care setting. This will be a pilot study to determine whether an educational intervention aimed at primary care teams to deliver problem focused therapy for insomnia can improve sleep management and outcomes for individual adult patients presenting to general practice. The study will also test procedures and collect information in preparation for a larger definitive cluster-randomised trial. The study is funded by The Health Foundation

    The EDGE-CALIFA Survey: Interferometric Observations of 126 Galaxies with CARMA

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    We present interferometric CO observations, made with the Combined Array for Millimeter-wave Astronomy (CARMA) interferometer, of galaxies from the Extragalactic Database for Galaxy Evolution survey (EDGE). These galaxies are selected from the Calar Alto Legacy Integral Field Area (CALIFA) sample, mapped with optical integral field spectroscopy. EDGE provides good-quality CO data (3σ sensitivity before inclination correction, resolution ∌1.4 kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey and data characteristics and products, then present initial science results. We find that the exponential scale lengths of the molecular, stellar, and star-forming disks are approximately equal, and galaxies that are more compact in molecular gas than in stars tend to show signs of interaction. We characterize the molecular-to-stellar ratio as a function of Hubble type and stellar mass and present preliminary results on the resolved relations between the molecular gas, stars, and star-formation rate. We then discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key data set to address outstanding topics regarding gas and its role in star formation and galaxy evolution, which will be publicly available on completion of the quality assessment.Fil: Bolatto, Alberto. University of Maryland; Estados UnidosFil: Wong, Tony. University of Illinois at Urbana; Estados UnidosFil: Utomo, Dyas. University of California at Berkeley; Estados UnidosFil: Blitz, Leo. University of California at Berkeley; Estados UnidosFil: Vogel, Stuart N.. University of Maryland; Estados UnidosFil: SĂĄnchez, SebastiĂĄn F.. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Barrera-Ballesteros, Jorge. University Johns Hopkins; Estados UnidosFil: Cao, Yixian. University of Illinois; Estados UnidosFil: Colombo, Dario. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Dannerbauer, Helmut. Universidad de La Laguna; EspañaFil: GarcĂ­a-Benito, RubĂ©n. Instituto de AstrofĂ­sica de AndalucĂ­a; EspañaFil: Herrera-Camus, Rodrigo. Max Planck Institute fĂŒr Extraterrestrische Physik; AlemaniaFil: Husemann, Bernd. Max-Planck-Institut fĂŒr Astronomie; AlemaniaFil: Kalinova, Veselina. Max Planck Institut fĂŒr Radioastronomie; AlemaniaFil: Leroy, Adam K.. Ohio State University; Estados UnidosFil: Leung, Gigi. Max-Planck-Institut fĂŒr Astronomie; AlemaniaFil: Levy, Rebecca C.. University of Maryland; Estados UnidosFil: Mast, Damian. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba; ArgentinaFil: Ostriker, Eve. University of Princeton; Estados UnidosFil: Rosolowsky, Erik. University of Alberta; CanadĂĄFil: Sandstrom, Karin M.. University of California at San Diego; Estados UnidosFil: Teuben, Peter. University of Maryland; Estados UnidosFil: Van De Ven, Glenn. Max-Planck-Institut fĂŒr Astronomie; AlemaniaFil: Walter, Fabian. Max-Planck-Institut fĂŒr Astronomie; Alemani

    The EDGE-CALIFA survey: Using optical extinction to probe the spatially resolved distribution of gas in nearby galaxies

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    We present an empirical relation between the cold gas surface density (ÎŁgas) and the optical extinction (AV) in a sample of 103 galaxies from the Extragalactic Database for Galaxy Evolution (EDGE) survey. This survey provides CARMA interferometric CO observations for 126 galaxies included in the Calar Alto Legacy Integral Field Area (CALIFA) survey. The matched, spatially resolved nature of these data sets allows us to derive the ÎŁgas-AV relation on global, radial, and kpc (spaxel) scales. We determine AV from the Balmer decrement (H α/H ÎČ). We find that the best fit for this relation is ÎŁgas (M☉ pc−2) ∌ 26 × AV (mag), and that it does not depend on the spatial scale used for the fit. However, the scatter in the fits increases as we probe smaller spatial scales, reflecting the complex relative spatial distributions of stars, gas, and dust. We investigate the ÎŁgas/AV ratio on radial and spaxel scales as a function of EW(H α). We find that at larger values of EW(H α ) (i.e. actively star-forming regions) this ratio tends to converge to twice the value expected for a foreground dust screen geometry (∌30 M☉ pc−2 mag−1). On radial scales, we do not find a significant relation between the ÎŁgas/AV ratio and the ionized gas metallicity. We contrast our estimates of ÎŁgas using AV with compilations in the literature of the gas fraction on global and radial scales as well as with well-known scaling relations such as the radial star formation law and the ÎŁgas-Σ∗ relation. These tests show that optical extinction is a reliable proxy for estimating ÎŁgas in the absence of direct sub/millimeter observations of the cold gas.Fil: Barrera Ballesteros, Jorge K.. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Utomo, Dyas. Ohio State University; Estados UnidosFil: Bolatto, Alberto. University of Maryland; Estados UnidosFil: SĂĄnchez, SebastiĂĄn F.. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Vogel, Stuart N.. University of Maryland; Estados UnidosFil: Wong, Tony. University of Illinois; Estados UnidosFil: Levy, Rebecca C.. University of Maryland; Estados UnidosFil: Colombo, Dario. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Kalinova, Veselina. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Teuben, Peter. University of Maryland; Estados UnidosFil: GarcĂ­a Benito, RubĂ©n. Instituto de AstrofĂ­sica de AndalucĂ­a; EspañaFil: Husemann, Bernd. Max Planck Institut Fur Astronomie; AlemaniaFil: Mast, Damian. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de AstronomĂ­a TeĂłrica y Experimental. Universidad Nacional de CĂłrdoba. Observatorio AstronĂłmico de CĂłrdoba. Instituto de AstronomĂ­a TeĂłrica y Experimental; ArgentinaFil: Blitz, Leo. University of California at Berkeley; Estados Unido

    The EDGE-CALIFA survey: validating stellar dynamical mass models with CO kinematics

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    Deriving circular velocities of galaxies from stellar kinematics can provide an estimate of their total dynamical mass, provided a contribution from the velocity dispersion of the stars is taken into account. Molecular gas (e.g., CO) on the other hand, is a dynamically cold tracer and hence acts as an independent circular velocity estimate without needing such a correction. In this paper we test the underlying assumptions of three commonly used dynamical models, deriving circular velocities from stellar kinematics of 54 galaxies (S0-Sd) that have observations of both stellar kinematics from the CALIFA survey, and CO kinematics from the EDGE survey. We test the Asymmetric Drift Correction (ADC) method, as well as Jeans, and Schwarzschild models. The three methods each reproduce the CO circular velocity at 1Re to within 10%. All three methods show larger scatter (up to 20%) in the inner regions (R < 0.4Re) which may be due to an increasingly spherical mass distribution (which is not captured by the thin disk assumption in ADC), or non-constant stellar M/L ratios (for both the JAM and Schwarzschild models). This homogeneous analysis of stellar and gaseous kinematics validates that all three models can recover Mdyn at 1Re to better than 20%, but users should be mindful of scatter in the inner regions where some assumptions may break down.Comment: 22 pages, 18 figures, Accepted for publication in MNRA

    Dynamical Equilibrium in the Molecular ISM in 28 Nearby Star-forming Galaxies

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    We compare the observed turbulent pressure in molecular gas, P_(turb), to the required pressure for the interstellar gas to stay in equilibrium in the gravitational potential of a galaxy, P_(DE). To do this, we combine arcsecond resolution CO data from PHANGS-ALMA with multiwavelength data that trace the atomic gas, stellar structure, and star formation rate (SFR) for 28 nearby star-forming galaxies. We find that P_(turb) correlates with—but almost always exceeds—the estimated P_(DE) on kiloparsec scales. This indicates that the molecular gas is overpressurized relative to the large-scale environment. We show that this overpressurization can be explained by the clumpy nature of molecular gas; a revised estimate of P_(DE) on cloud scales, which accounts for molecular gas self-gravity, external gravity, and ambient pressure, agrees well with the observed P_(turb) in galaxy disks. We also find that molecular gas with cloud-scale P_(turb) ≈ P_(DE) ≳ 10⁔ kB K cm⁻³ in our sample is more likely to be self-gravitating, whereas gas at lower pressure it appears more influenced by ambient pressure and/or external gravity. Furthermore, we show that the ratio between P_(turb) and the observed SFR surface density, ÎŁ_(SFR), is compatible with stellar feedback-driven momentum injection in most cases, while a subset of the regions may show evidence of turbulence driven by additional sources. The correlation between ÎŁ_(SFR) and kpc-scale P_(DE) in galaxy disks is consistent with the expectation from self-regulated star formation models. Finally, we confirm the empirical correlation between molecular-to-atomic gas ratio and kpc-scale P_(DE) reported in previous works

    Do Spectroscopic Dense Gas Fractions Track Molecular Cloud Surface Densities?

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    We use ALMA and IRAM 30-m telescope data to investigate the relationship between the spectroscopically-traced dense gas fraction and the cloud-scale (120 pc) molecular gas surface density in five nearby, star-forming galaxies. We estimate the dense gas mass fraction at 650 pc and 2800 pc scales using the ratio of HCN (1-0) to CO (1-0) emission. We then use high resolution (120 pc) CO (2-1) maps to calculate the mass-weighted average molecular gas surface density within 650 pc or 2770 pc beam where the dense gas fraction is estimated. On average, the dense gas fraction correlates with the mass-weighted average molecular gas surface density. Thus, parts of a galaxy with higher mean cloud-scale gas surface density also appear to have a larger fraction of dense gas. The normalization and slope of the correlation do vary from galaxy to galaxy and with the size of the regions studied. This correlation is consistent with a scenario where the large-scale environment sets the gas volume density distribution, and this distribution manifests in both the cloud-scale surface density and the dense gas mass fraction.Comment: 11 pages, 4 figures, accepted for publication in The Astrophysical Journal Letter
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