1,848 research outputs found

    The Nature of Crime by School Resource Officers: Implications for SRO Programs

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    School resource officers (SROs) have become a permanent presence in many K-12 schools throughout the country. As a result, an emerging body of research has focused on SROs, particularly on how SROs are viewed by students, teachers, and the general public. This exploratory and descriptive research employs a different focus by examining the nature of crimes for which SROs were arrested in recent years with information gathered from online news sources. The current findings are encouraging insofar as they reveal that SROs are rarely arrested for criminal misconduct. When SROs were arrested, however, they are most often arrested for a sex-related offense involving a female adolescent. These sex-related incidents generally occurred away from school property or during nonschool hours and rarely involved the use of physical force. The implications of these findings for SRO programs are discussed

    An Exploration of Change or Stability Over Time (2005-2018) in the Number and Likelihood of Police Officers Arrested, Dismissed, and Convicted for On- and Off-Duty Misconduct

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    This research was presented at the annual conference of the Midwestern Criminal Justice Association on September 28, 2023, in Chicago, IL

    An Exploration of the Nature and Disposition of Crimes Committed by Sheriffs and Sheriff’s Deputies

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    Presentation at the Annual Meeting of the Academy of Criminal Justice Sciences, Las Vegas, NV, on March 18, 2022

    Pseudorehearsal in value function approximation

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    Catastrophic forgetting is of special importance in reinforcement learning, as the data distribution is generally non-stationary over time. We study and compare several pseudorehearsal approaches for Q-learning with function approximation in a pole balancing task. We have found that pseudorehearsal seems to assist learning even in such very simple problems, given proper initialization of the rehearsal parameters

    Hachimoji DNA and RNA: A genetic system with eight building blocks

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    Reported here are DNA and RNA-like systems built from eight (hachi-) nucleotide letters (-moji) that form four orthogonal pairs. This synthetic genetic biopolymer meets the structural requirements needed to support Darwinism, including a polyelectrolyte backbone, predictable thermodynamic stability, and stereoregular building blocks that fit a Schrödinger aperiodic crystal. Measured thermodynamic parameters predict the stability of hachimoji duplexes, allowing hachimoji DNA to double the information density of natural terran DNA. Three crystal structures show that the synthetic building blocks do not perturb the aperiodic crystal seen in the DNA double helix. Hachimoji DNA was then transcribed to give hachimoji RNA in the form of a functioning fluorescent hachimoji aptamer. These results expand the scope of molecular structures that might support life, including life throughout the cosmos

    Paternal diet programs offspring health through sperm- and seminal plasma-specific pathways in mice

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    Parental health and diet at the time of conception determine the development and life-long disease risk of their offspring. While the association between poor maternal diet and offspring health is well established, the underlying mechanisms linking paternal diet with offspring health are poorly defined. Possible programming pathways include changes in testicular and sperm epigenetic regulation and status, seminal plasma composition, and maternal reproductive tract responses regulating early embryo development. In this study, we demonstrate that paternal low-protein diet induces sperm-DNA hypomethylation in conjunction with blunted female reproductive tract embryotrophic, immunological, and vascular remodeling responses. Furthermore, we identify sperm- and seminal plasma-specific programming effects of paternal diet with elevated offspring adiposity, metabolic dysfunction, and altered gut microbiota

    The molecular phenotype of human cardiac myosin associated with hypertrophic obstructive cardiomyopathy

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    AIM: The aim of the study was to compare the functional and structural properties of the motor protein, myosin, and isolated myocyte contractility in heart muscle excised from hypertrophic cardiomyopathy patients by surgical myectomy with explanted failing heart and non-failing donor heart muscle. METHODS: Myosin was isolated and studied using an in vitro motility assay. The distribution of myosin light chain-1 isoforms was measured by two-dimensional electrophoresis. Myosin light chain-2 phosphorylation was measured by sodium dodecyl sulphate-polyacrylamide gel electrophoresis using Pro-Q Diamond phosphoprotein stain. RESULTS: The fraction of actin filaments moving when powered by myectomy myosin was 21% less than with donor myosin (P = 0.006), whereas the sliding speed was not different (0.310 +/- 0.034 for myectomy myosin vs. 0.305 +/- 0.019 microm/s for donor myosin in six paired experiments). Failing heart myosin showed 18% reduced motility. One myectomy myosin sample produced a consistently higher sliding speed than donor heart myosin and was identified with a disease-causing heavy chain mutation (V606M). In myectomy myosin, the level of atrial light chain-1 relative to ventricular light chain-1 was 20 +/- 5% compared with 11 +/- 5% in donor heart myosin and the level of myosin light chain-2 phosphorylation was decreased by 30-45%. Isolated cardiomyocytes showed reduced contraction amplitude (1.61 +/- 0.25 vs. 3.58 +/- 0.40%) and reduced relaxation rates compared with donor myocytes (TT(50%) = 0.32 +/- 0.09 vs. 0.17 +/- 0.02 s). CONCLUSION: Contractility in myectomy samples resembles the hypocontractile phenotype found in end-stage failing heart muscle irrespective of the primary stimulus, and this phenotype is not a direct effect of the hypertrophy-inducing mutation. The presence of a myosin heavy chain mutation causing hypertrophic cardiomyopathy can be predicted from a simple functional assay

    Joint analysis of X-ray and Sunyaev Zel'dovich observations of galaxy clusters using an analytic model of the intra-cluster medium

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    We perform a joint analysis of X-ray and Sunyaev Zel'dovich (SZ) effect data using an analytic model that describes the gas properties of galaxy clusters. The joint analysis allows the measurement of the cluster gas mass fraction profile and Hubble constant independent of cosmological parameters. Weak cosmological priors are used to calculate the overdensity radius within which the gas mass fractions are reported. Such an analysis can provide direct constraints on the evolution of the cluster gas mass fraction with redshift. We validate the model and the joint analysis on high signal-to-noise data from the Chandra X-ray Observatory and the Sunyaev-Zel'dovich Array for two clusters, Abell 2631 and Abell 2204.Comment: ApJ in pres

    Equatorial Superrotation on Tidally Locked Exoplanets

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    The increasing richness of exoplanet observations has motivated a variety of three-dimensional (3D) atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or "superrotating," jet stream at the equator. When the radiative and advection timescales are comparable, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been subsequently observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing Rossby waves induced by the day-night thermal forcing. The strong longitudinal variations in radiative heating—namely intense dayside heating and nightside cooling—trigger the formation of standing, planetary-scale equatorial Rossby and Kelvin waves. The Rossby waves develop phase tilts that pump eastward momentum from high latitudes to the equator, thereby inducing equatorial superrotation. We present an analytic theory demonstrating this mechanism and explore its properties in a hierarchy of one-layer (shallow-water) calculations and fully 3D models. The wave-mean-flow interaction produces an equatorial jet whose latitudinal width is comparable to that of the Rossby waves, namely the equatorial Rossby deformation radius modified by radiative and frictional effects. For conditions typical of synchronously rotating hot Jupiters, this length is comparable to a planetary radius, explaining the broad scale of the equatorial jet obtained in most hot-Jupiter models. Our theory illuminates the dependence of the equatorial jet speed on forcing amplitude, strength of friction, and other parameters, as well as the conditions under which jets can form at all
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