2,447 research outputs found

    High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization

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    The liberalization of marijuana policies, including the legalization of medical and recreational marijuana, is sweeping the United States and other countries. Marijuana cultivation can have significant negative collateral effects on the environment that are often unknown or overlooked. Focusing on the state of California, where by some estimates 60% -- 70% of the marijuana consumed in the United States is grown, we argue that (a) the environmental harm caused by marijuana cultivation merits a direct policy response, (b) current approaches to governing the environmental effects are inadequate, and (c) neglecting discussion of the environmental impacts of cultivation when shaping future marijuana use and possession policies represents a missed opportunity to reduce, regulate, and mitigate environmental harm

    Comparison of Cell Sediment and Surface Grown Test Plaque Using Scanning Electron Microscopy

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    Scanning electron microscopy was used to compare the morphology, integrity and distribution of bacterial cells in a test plaque grown on the surface of enamel with that of the cell sediment plaque routinely used in a short-term intraoral caries model. Cultures of S. mutans IB-1600 or S. sobrinus 6715-13 were grown in complex media supplemented with either 2.0% sucrose (glucan plaque) or 0.2 % glucose (non-glucan plaque). Cell sediment (CS) plaque was prepared by centrifuging the cultures after incubation, recovering the cell sediment, and spreading it on Metricel membrane filter paper. Surface grown (SG) plaque was prepared by suspending saliva-coated bovine enamel in the culture inedium, incubating, and recovering the enamel assembly with bacterial accumulations. Cell morphology and integrity, as well as the appearance of glucan-like material produced by the cells, was similar in both CS and SG test plaques. The cell distribution however, varied in the SG plaque from extremes of all cells to all glucan, whereas the cell sediment plaque was more uniform in cell distribution. A highly standardized test plaque minimizes variability in the intraoral caries model. These findings support the contention that the bacterial cells in a cell sediment plaque are similar in morphology, integrity and glucan production to surface grown plaque, and have the added advantage of uniform distribution, which makes the cell sediment plaque more appropriate for intraoral caries model studies

    The SAMI Galaxy Survey: mass-kinematics scaling relations

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    We use data from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy stellar mass MM_* and the general kinematic parameter SK=KVrot2+σ2S_K = \sqrt{K V_{rot}^2 + \sigma^2} that combines rotation velocity VrotV_{rot} and velocity dispersion σ\sigma. We show that the logMlogSK\log M_* - \log S_K relation: (1)~is linear above limits set by properties of the samples and observations; (2)~has slightly different slope when derived from stellar or gas kinematic measurements; (3)~applies to both early-type and late-type galaxies and has smaller scatter than either the Tully-Fisher relation (logMlogVrot\log M_* - \log V_{rot}) for late types or the Faber-Jackson relation (logMlogσ\log M_* - \log\sigma) for early types; and (4)~has scatter that is only weakly sensitive to the value of KK, with minimum scatter for KK in the range 0.4 and 0.7. We compare SKS_K to the aperture second moment (the `aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture (σ3\sigma_{3^{\prime\prime}}). We find that while SKS_{K} and σ3\sigma_{3^{\prime\prime}} are in general tightly correlated, the logMlogSK\log M_* - \log S_K relation has less scatter than the logMlogσ3\log M_* - \log \sigma_{3^{\prime\prime}} relation.Comment: 14 pages, 8 figures, Accepted 2019 May 22. Received 2019 May 18; in original form 2019 January

    The SAMI Galaxy Survey: Revising the Fraction of Slow Rotators in IFS Galaxy Surveys

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    The fraction of galaxies supported by internal rotation compared to galaxies stabilized by internal pressure provides a strong constraint on galaxy formation models. In integral field spectroscopy surveys, this fraction is biased because survey instruments typically only trace the inner parts of the most massive galaxies. We present aperture corrections for the two most widely used stellar kinematic quantities V/σV/\sigma and λR\lambda_{R}. Our demonstration involves integral field data from the SAMI Galaxy Survey and the ATLAS3D^{\rm{3D}} Survey. We find a tight relation for both V/σV/\sigma and λR\lambda_{R} when measured in different apertures that can be used as a linear transformation as a function of radius, i.e., a first-order aperture correction. We find that V/σV/\sigma and λR\lambda_{R} radial growth curves are well approximated by second order polynomials. By only fitting the inner profile (0.5ReR_{\rm{e}}), we successfully recover the profile out to one ReR_{\rm{e}} if a constraint between the linear and quadratic parameter in the fit is applied. However, the aperture corrections for V/σV/\sigma and λR\lambda_{R} derived by extrapolating the profiles perform as well as applying a first-order correction. With our aperture-corrected λR\lambda_{R} measurements, we find that the fraction of slow rotating galaxies increases with stellar mass. For galaxies with logM/M>\log M_{*}/M_{\odot}> 11, the fraction of slow rotators is 35.9±4.335.9\pm4.3 percent, but is underestimated if galaxies without coverage beyond one ReR_{\rm{e}} are not included in the sample (24.2±5.324.2\pm5.3 percent). With measurements out to the largest aperture radius the slow rotator fraction is similar as compared to using aperture corrected values (38.3±4.438.3\pm4.4 percent). Thus, aperture effects can significantly bias stellar kinematic IFS studies, but this bias can now be removed with the method outlined here.Comment: Accepted for Publication in the Monthly Notices of the Royal Astronomical Society. 16 pages and 11 figures. The key figures of the paper are: 1, 4, 9, and 1

    Self-reported psychopathy in the Middle East: a cross-national comparison across Egypt, Saudi Arabia, and the United States

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    Background: The construct of psychopathy is sparsely researched in the non-Western world, particularly in the Middle East. As such, the extent to which the psychopathy construct can be generalized to other cultures, including Middle Eastern Arab cultures, is largely unknown. Methods: The present study investigated the cross-cultural/national comparability of self-reported psychopathy in the United States (N = 786), Egypt (N = 296), and Saudi Arabia (N = 341). Results: A widely used psychopathy questionnaire demonstrated largely similar properties across the American and Middle Eastern samples and associations between Five Factor Model (FFM) personality and psychopathy were broadly consistent. Nevertheless, several notable cross-cultural differences emerged, particularly with regard to the internal consistencies of psychopathy dimensions and the correlates of Coldheartedness. Additionally, in contrast to most findings in Western cultures, associations between psychopathy and FFM personality varied consistently by gender in the Egyptian sample. Conclusions: These findings lend preliminary support to the construct validity of self-reported psychopathy in Arabic-speaking cultures, providing provisional evidence for the cross-cultural generalizability of certain core characteristics of psychopathy

    Self-Healing Polymer Materials for Wire Insulation, Polyimides, Flat Surfaces, and Inflatable Structures

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    Materials based on low melt polyimide, polyurea, or polyurethane chemistry have been developed which exhibit self-healing properties. These high performance polymers can be utilized either by themselves or in combination with microcapsule technology to deliver self-healing properties to electrical wire insulation or in other high performance, thin wall technologies such as inflatable structures

    Positive Surgical Margins in the 10 Most Common Solid Cancers.

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    A positive surgical margin (PSM) following cancer resection oftentimes necessitates adjuvant treatments and carries significant financial and prognostic implications. We sought to compare PSM rates for the ten most common solid cancers in the United States, and to assess trends over time. Over 10 million patients were identified in the National Cancer Data Base from 1998-2012, and 6.5 million had surgical margin data. PSM rates were compared between two time periods, 1998-2002 and 2008-2012. PSM was positively correlated with tumor category and grade. Ovarian and prostate cancers had the highest PSM prevalence in women and men, respectively. The highest PSM rates for cancers affecting both genders were seen for oral cavity tumors. PSM rates for breast cancer and lung and bronchus cancer in both men and women declined over the study period. PSM increases were seen for bladder, colon and rectum, and kidney and renal pelvis cancers. This large-scale analysis appraises the magnitude of PSM in the United States in order to focus future efforts on improving oncologic surgical care with the goal of optimizing value and improving patient outcomes

    The SAMI Galaxy Survey: Global stellar populations on the size-mass plane

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    We present an analysis of the global stellar populations of galaxies in the SAMI Galaxy Survey. Our sample consists of 1319 galaxies spanning four orders of magnitude in stellar mass and includes all morphologies and environments. We derive luminosity-weighted, single stellar population equivalent stellar ages, metallicities and alpha enhancements from spectra integrated within one effective radius apertures. Variations in galaxy size explain the majority of the scatter in the age--mass and metallicity--mass relations. Stellar populations vary systematically in the plane of galaxy size and stellar mass, such that galaxies with high stellar surface mass density are older, more metal-rich and alpha-enhanced than less dense galaxies. Galaxies with high surface mass densities have a very narrow range of metallicities, however, at fixed mass, the spread in metallicity increases substantially with increasing galaxy size (decreasing density). We identify residual correlations with morphology and environment. At fixed mass and size, galaxies with late-type morphologies, small bulges and low Sersic n are younger than early-type, high n, high bulge-to-total galaxies. Age and metallicity both show small residual correlations with environment; at fixed mass and size, galaxies in denser environments or more massive halos are older and somewhat more metal rich than those in less dense environments. We connect these trends to evolutionary tracks within the size--mass plane.Comment: 25 pages, 18 figures, MNRAS in press Corrected typo in author lis
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