385 research outputs found

    Do Distinct Groups of Reactively and Proactively Aggressive Children Exist? A Confirmatory Latent Profile Approach

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    The present study examined whether there are distinct groups of children with reactive versus proactive motives for their aggressive behavior. We extended previous research by using a person-based analytical approach on data from a questionnaire assessing childrenā€™s motives independently from the severity of their aggression. Two competing hypotheses were tested. The both subtypes hypothesis holds that both reactive and proactive subtypes exist, as well as a mixed subtype. The reactive only hypothesis holds that only reactive and mixed subtypes exist. Hypotheses were tested on existing data from a community sample of children displaying aggression (Study 1: nā€‰=ā€‰228, ages 10ā€“13, 54% boys), and two clinical samples of children with aggressive behavior problems (Study 2: nā€‰=ā€‰115, ages 8ā€“13, 100% boys; Study 3: nā€‰=ā€‰123, ages 6ā€“8, 78% boys). Teachers reported on childrenā€™s reactive and proactive motives. We selected measures available from peers, parents, teachers, and children themselves to compare the supported subtypes on variables that previous literature suggests uniquely correlate with reactive versus proactive aggression. Confirmatory latent profile analyses revealed that the both subtypes hypothesis best fit the data of all three samples. Most children were classified as reactive (55.7ā€“61.8% across samples), with smaller percentages classified as proactive (10.4ā€“24.1%) and mixed (18.0ā€“33.9%). However, these subtypes only differed in expected directions on 7 out of 34 measures. Overall, results support the existence of both reactive and proactive subtypes of aggressive children, but the distinctiveness of these subtypes in terms of social-emotional characteristics warrants further study. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10802-021-00813-0

    Transport Phenomena in Alcator C-Mod H-Modes

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    Abstract. Several interesting new results have come from studies of ICRF-heated, H-mode plasmas in Alcator C-Mod. Dimensionless scaling studies have found gyro-Bohm-like transport similar to that reported on other devices; however, the dependence on collisionality was surprisingly strong, with BE āˆ’1. Despite high edge temperatures and strong edge pressure gradients, type I edge-localized modes (ELMs) are not observed in C-Mod. Instead we obtain a regime that we have dubbed enhanced D (EDA) which is accompanied by high-frequency density fluctuations. For all H-modes, core gradients were found to increase linearly with edge temperature, suggesting the importance of critical gradient/marginal stability behaviour. Comparisons with the IFS-PPPL model have begun, showing quantitative agreement in some cases. Impurity particle transport was studied via the laser blow-off technique with impurity confinement found to be effectively infinite for ELM-free discharges but reduced into the range 0.1ā€“0.2 s for the EDA plasmas. 1

    H-mode edge stability of Alcator C-mod plasmas

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    ISPIDER Central: an integrated database web-server for proteomics

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    Despite the growing volumes of proteomic data, integration of the underlying results remains problematic owing to differences in formats, data captured, protein accessions and services available from the individual repositories. To address this, we present the ISPIDER Central Proteomic Database search (http://www.ispider.manchester.ac.uk/cgi-bin/ProteomicSearch.pl), an integration service offering novel search capabilities over leading, mature, proteomic repositories including PRoteomics IDEntifications database (PRIDE), PepSeeker, PeptideAtlas and the Global Proteome Machine. It enables users to search for proteins and peptides that have been characterised in mass spectrometry-based proteomics experiments from different groups, stored in different databases, and view the collated results with specialist viewers/clients. In order to overcome limitations imposed by the great variability in protein accessions used by individual laboratories, the European Bioinformatics Institute's Protein Identifier Cross-Reference (PICR) service is used to resolve accessions from different sequence repositories. Custom-built clients allow users to view peptide/protein identifications in different contexts from multiple experiments and repositories, as well as integration with the Dasty2 client supporting any annotations available from Distributed Annotation System servers. Further information on the protein hits may also be added via external web services able to take a protein as input. This web server offers the first truly integrated access to proteomics repositories and provides a unique service to biologists interested in mass spectrometry-based proteomics

    Mean field approach to antiferromagnetic domains in the doped Hubbard model

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    We present a restricted path integral approach to the 2D and 3D repulsive Hubbard model. In this approach the partition function is approximated by restricting the summation over all states to a (small) subclass which is chosen such as to well represent the important states. This procedure generalizes mean field theory and can be systematically improved by including more states or fluctuations. We analyze in detail the simplest of these approximations which corresponds to summing over states with local antiferromagnetic (AF) order. If in the states considered the AF order changes sufficiently little in space and time, the path integral becomes a finite dimensional integral for which the saddle point evaluation is exact. This leads to generalized mean field equations allowing for the possibility of more than one relevant saddle points. In a big parameter regime (both in temperature and filling), we find that this integral has {\em two} relevant saddle points, one corresponding to finite AF order and the other without. These degenerate saddle points describe a phase of AF ordered fermions coexisting with free, metallic fermions. We argue that this mixed phase is a simple mean field description of a variety of possible inhomogeneous states, appropriate on length scales where these states appear homogeneous. We sketch systematic refinements of this approximation which can give more detailed descriptions of the system.Comment: 14 pages RevTex, 6 postscript figures included using eps
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