1,139 research outputs found

    Incremental and Predictive Validity of the Antisocial Process Screening Device in a Community Sample of Male and Female Ethnic Minority and Caucasian Youth

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    The Antisocial Process Screening Device (APSD) is a well-supported tool for assessing psychopathic features in youth. However, most research with the APSD has been derived from clinical and forensic samples comprised mainly of male Caucasian and African American adolescents. In this prospective study, the incremental and predictive validity of the self-report APSD for violent and non-violent offending was examined in an ethnically diverse community sample of male and female youth (N = 335) aged 12 to 14. High-school students from a moderate sized city in Western Canada completed the self-report APSD and then completed the Self-Report of Offending 6 months later. Receiver Operating Characteristics analysis indicated that APSD total and subscale scores were predictive of violent and non-violent offending at 6-month follow-up with moderate to large effect sizes. In addition, total scores on the APSD added incremental predictive utility above and beyond traditional criminogenic predictors of youth offending (i.e., prior offending, delinquent peer affiliation, poor school achievement, substance use, low parental monitoring). Although sex differences emerged in the predictive utility of the Impulsivity subscale of the APSD vis-à-vis violent offending, sex did not moderate the relationship between APSD total, Narcissism, or Callous/Unemotional scores and offending. In addition, the predictive utility of the APSD did not vary as a function of the youth’s ethnic background. These findings suggest that: (1) the self-report APSD may have utility for risk or threat assessment with normative school populations, (2) APSD findings from higher risk samples generalize to a lower risk sample of high-school youth, and (3) predictive utility of APSD total scores do not differ across male and female Caucasian and ethnic minority youth. &nbsp

    Toric moment mappings and Riemannian structures

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    Coadjoint orbits for the group SO(6) parametrize Riemannian G-reductions in six dimensions, and we use this correspondence to interpret symplectic fibrations between these orbits, and to analyse moment polytopes associated to the standard Hamiltonian torus action on the coadjoint orbits. The theory is then applied to describe so-called intrinsic torsion varieties of Riemannian structures on the Iwasawa manifold.Comment: 25 pages, 14 figures; Geometriae Dedicata 2012, Toric moment mappings and Riemannian structures, available at http://www.springerlink.com/content/yn86k22mv18p8ku2

    Invariant Measures and Decay of Correlations for a Class of Ergodic Probabilistic Cellular Automata

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    We give new sufficient ergodicity conditions for two-state probabilistic cellular automata (PCA) of any dimension and any radius. The proof of this result is based on an extended version of the duality concept. Under these assumptions, in the one dimensional case, we study some properties of the unique invariant measure and show that it is shift-mixing. Also, the decay of correlation is studied in detail. In this sense, the extended concept of duality gives exponential decay of correlation and allows to compute explicitily all the constants involved

    Thirty Years of Cometary Spectroscopy from McDonald Observatory

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    We report on the results of a spectroscopic survey of 130 comets that was conducted at McDonald observatory from 1980 through 2008. Some of the comets were observed on only one night, while others were observed repeatedly. For 20 of these comets, no molecules were detected. For the remaining 110 comets, some emission from CN, OH, NH, C3_{3}, C2_{2}, CH, and NH2_{2} molecules were observed on at least one occasion. We converted the observed molecular column densities to production rates using a Haser (1957) model. We defined a restricted data set of comets that had at least 3 nights of observations. The restricted data set consists of 59 comets. We used ratios of production rates to study the trends in the data. We find two classes of comets: typical and carbon-chain depleted comets. Using a very strict definition of depleted comets, requiring C2_{2} \underline{and} C3_{3} to both be depleted, we find 9% of our restricted data set comets to be depleted. Using a more relaxed definition that requires only C2_{2} to be below a threshold (similar to other researchers), we find 25% of the comets are depleted. Two-thirds of the depleted comets are Jupiter Family comets, while one-third are Long Period comets. 37% of the Jupiter Family comets are depleted, while 18.5% of the Long Period comets are depleted. We compare our results with other studies and find good agreement.Comment: Accepted for Icarus; 15 figures, 9 tables (some multi-page and in landscape mode

    Neuropsychological constraints to human data production on a global scale

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    Which are the factors underlying human information production on a global level? In order to gain an insight into this question we study a corpus of 252-633 Million publicly available data files on the Internet corresponding to an overall storage volume of 284-675 Terabytes. Analyzing the file size distribution for several distinct data types we find indications that the neuropsychological capacity of the human brain to process and record information may constitute the dominant limiting factor for the overall growth of globally stored information, with real-world economic constraints having only a negligible influence. This supposition draws support from the observation that the files size distributions follow a power law for data without a time component, like images, and a log-normal distribution for multimedia files, for which time is a defining qualia.Comment: to be published in: European Physical Journal

    Closed forms and multi-moment maps

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    We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps are guaranteed to exist and are unique when the symmetry group is (3,4)-trivial, meaning that the group is connected and the third and fourth Lie algebra Betti numbers vanish. We give a structural description of some classes of (3,4)-trivial algebras and provide a number of examples.Comment: 36 page

    Production and decay of the Standard Model Higgs Bososn at LEP200

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    We collect and update theoretical predictions for the production rate and decay branching fractions of the Standard Model Higgs boson that will be relevant for the Higgs search at LEP200. We make full use of the present knowledge of radiative corrections. We estimate the systematics arising from theoretical and experimental uncertainties.Comment: 27 page

    Testing non-perturbative strong interaction effects via the Adler function

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    Based on the compilation of the available e^+e^- data, we present a non-perturbative estimation of the Adler function derived from the electromagnetic current correlator, and compare it with theoretical predictions from perturbative QCD (pQCD). The comparison is presented for the Euclidean region where pQCD is supposed to work best. We emphasize that such a comparison only makes sense if one takes into account the exact mass dependence of the perturbative predictions, which are available for the leading and next to leading (two-loop) order. In order to have the correct physical mass dependence in the evolution of the strong coupling as well, we utilize the MOM scheme beta-function to two-loops calculated recently. Three-loop effects, which are available as series expansions for low and high momentum transfer, are included by using Pade improvement. We discuss possible constraints on non-perturbative effects as suggested by the operator product expansion.Comment: 14 pages, 5 figure

    Wolbachia wStri blocks Zika virus growth at two independent stages of viral replication

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    Mosquito-transmitted viruses are spread globally and present a great risk to human health. Among the many approaches investigated to limit the diseases caused by these viruses are attempts to make mosquitos resistant to virus infection. Coinfection of mosquitos with the bacterium Wolbachia pipientis from supergroup A is a recent strategy employed to reduce the capacity for major vectors in the Aedes mosquito genus to transmit viruses, including dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Recently, a supergroup B Wolbachia wStri, isolated from Laodelphax striatellus, was shown to inhibit multiple lineages of ZIKV in Aedes albopictus cells. Here, we show that wStri blocks the growth of positive-sense RNA viruses DENV, CHIKV, ZIKV, and yellow fever virus by greater than 99.9%. wStri presence did not affect the growth of the negative-sense RNA viruses LaCrosse virus or vesicular stomatitis virus. Investigation of the stages of the ZIKV life cycle inhibited by wStri identified two distinct blocks in viral replication. We found a reduction of ZIKV entry into wStri-infected cells. This was partially rescued by the addition of a cholesterol-lipid supplement. Independent of entry, transfected viral genome was unable to replicate in Wolbachia-infected cells. RNA transfection and metabolic labeling studies suggested that this replication defect is at the level of RNA translation, where we saw a 66% reduction in mosquito protein synthesis in wStri-infected cells. This study’s findings increase the potential for application of wStri to block additional arboviruses and also identify specific blocks in viral infection caused by Wolbachia coinfection.R01 AI099210 - NIAID NIH HHSPublished versio

    Linear stability analysis of retrieval state in associative memory neural networks of spiking neurons

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    We study associative memory neural networks of the Hodgkin-Huxley type of spiking neurons in which multiple periodic spatio-temporal patterns of spike timing are memorized as limit-cycle-type attractors. In encoding the spatio-temporal patterns, we assume the spike-timing-dependent synaptic plasticity with the asymmetric time window. Analysis for periodic solution of retrieval state reveals that if the area of the negative part of the time window is equivalent to the positive part, then crosstalk among encoded patterns vanishes. Phase transition due to the loss of the stability of periodic solution is observed when we assume fast alpha-function for direct interaction among neurons. In order to evaluate the critical point of this phase transition, we employ Floquet theory in which the stability problem of the infinite number of spiking neurons interacting with alpha-function is reduced into the eigenvalue problem with the finite size of matrix. Numerical integration of the single-body dynamics yields the explicit value of the matrix, which enables us to determine the critical point of the phase transition with a high degree of precision.Comment: Accepted for publication in Phys. Rev.
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