385 research outputs found
Do Distinct Groups of Reactively and Proactively Aggressive Children Exist? A Confirmatory Latent Profile Approach
Do Distinct Groups of Reactively and Proactively Aggressive Children Exist? A Confirmatory Latent Profile Approach
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 childrenās 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=ā228, ages 10ā13, 54% boys), and two clinical samples of children with aggressive behavior problems (Study 2: nā=ā115, ages 8ā13, 100% boys; Study 3: nā=ā123, ages 6ā8, 78% boys). Teachers reported on childrenās 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 (55.7ā61.8% across samples), with smaller percentages classified as proactive (10.4ā24.1%) and mixed (18.0ā33.9%). 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
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 ā1. 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 0.1ā0.2 s for the EDA plasmas. 1
ISPIDER Central: an integrated database web-server for proteomics
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
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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