3,525 research outputs found
Effects of Violent Video Game Exposure on Aggressive Behavior, Aggressive thought Accessibility, and Aggressive Affect among Adults with and without Autism Spectrum Disorder
Recent mass shootings have prompted the idea among some members of the public that exposure to violent video games can have a pronounced effect on individuals with autism spectrum disorder (ASD). Empirical evidence for or against this claim currently is absent. To address this issue, adults with and without ASD were assigned to play a violent or nonviolent version of a customized first-person shooter video game, after which responses on three aggression-related outcome variables (aggressive behavior, aggressive thought accessibility, and aggressive affect) were assessed. Results showed strong evidence that adults with ASD are not differentially affected by acute exposure to violent video games compared to typically developing adults. Moreover, model comparisons showed modest evidence against any effect of violent game content whatsoever. Findings from the current experiment suggest that societal concerns over whether violent game exposure has a unique effect on adults with autism are not supported by evidence
A Minimum-Labeling Approach for Reconstructing Protein Networks across Multiple Conditions
The sheer amounts of biological data that are generated in recent years have
driven the development of network analysis tools to facilitate the
interpretation and representation of these data. A fundamental challenge in
this domain is the reconstruction of a protein-protein subnetwork that
underlies a process of interest from a genome-wide screen of associated genes.
Despite intense work in this area, current algorithmic approaches are largely
limited to analyzing a single screen and are, thus, unable to account for
information on condition-specific genes, or reveal the dynamics (over time or
condition) of the process in question. Here we propose a novel formulation for
network reconstruction from multiple-condition data and devise an efficient
integer program solution for it. We apply our algorithm to analyze the response
to influenza infection in humans over time as well as to analyze a pair of ER
export related screens in humans. By comparing to an extant, single-condition
tool we demonstrate the power of our new approach in integrating data from
multiple conditions in a compact and coherent manner, capturing the dynamics of
the underlying processes.Comment: Peer-reviewed and presented as part of the 13th Workshop on
Algorithms in Bioinformatics (WABI2013
Nucleon electromagnetic form factors from lattice QCD using a nearly physical pion mass
We present lattice QCD calculations of nucleon electromagnetic form factors
using pion masses = 149, 202, and 254 MeV and an action with
clover-improved Wilson quarks coupled to smeared gauge fields, as used by the
Budapest-Marseille-Wuppertal collaboration. Particular attention is given to
removal of the effects of excited state contamination by calculation at three
source-sink separations and use of the summation and generalized
pencil-of-function methods. The combination of calculation at the nearly
physical mass = 149 MeV in a large spatial volume ( = 4.2)
and removal of excited state effects yields agreement with experiment for the
electric and magnetic form factors and up to = 0.5
GeV.Comment: v2: published version; 30 pages, 25 figures, 6 table
The maternal social environment shapes offspring growth, physiology, and behavioural phenotype in guinea pigs.
Prenatal conditions influence offspring development in many species. In mammals, the effects of social density have traditionally been considered a detrimental form of maternal stress. Now their potential adaptive significance is receiving greater attention.Sex-specific effects of maternal social instability on offspring in guinea pigs (Cavia aperea f. porcellus) have been interpreted as adaptations to high social densities, while the effects of low social density are unknown. Hence, we compared morphological, behavioural and physiological development between offspring born to mothers housed either individually or in groups during the second half of pregnancy.Females housed individually and females housed in groups gave birth to litters of similar size and sex-ratios, and there were no differences in birth weight. Sons of individually-housed mothers grew faster than their sisters, whereas daughters ofgroup-housed females grew faster than their brothers, primarily due to an effect on growth of daughters. There were few effects on offspring behaviour. Baseline cortisol levels in saliva of pups on day 1 and day 7 were not affected, but we saw a blunted cortisol response to social separation on day 7 in sons of individually-housed females and daughters of group-housed females. The effects were consistent across two replicate experiments.The observed effects only partially support the adaptive hypothesis. Increased growth of daughters may be adaptive under high densities due to increasedfemale competition, but it is unclear why growth of sons is not increased under low social densities when males face less competition from older, dominant males. The differences in growth may be causally linked to sex-specific effects on cortisol response, although individual cortisol response and growth were not correlated, and various other mechanisms are possible. The observed sex-specific effects on early development are intriguing, yet the potential adaptive benefits and physiological mechanisms require further study
Routing of airplanes to two runways: monotonicity of optimal controls
We consider the problem of routing incoming airplanes to two runways of an airport. Due to air turbulence, the necessary separation time between two successive landing operations depends on the types of the airplanes. When viewed as a queueing problem, this means that we have dependent service times. The aim is to minimise waiting times of aircrafts. We consider here a model where arrivals form a stochastic process and where the decision maker does not know anything about future arrivals. We formulate this as a problem of stochastic dynamic programming and investigate monotonicity of optimal routing strategies with respect e.g. to the workload of the runways. We show that an optimal strategy is monotone (i.e. of switching type) only in a restricted case where decisions depend on the state of the runways only and not on the type of the arriving aircraft. Surprisingly, in the more realistic case where this type is also known to the decision maker, monotonicity need not hold
Signals of confinement in Green functions of SU(2) Yang-Mills theory
The vortex picture of confinement is employed to explore the signals of
confinement in Yang-Mills Green functions. By using SU(2) lattice gauge theory,
it has been well established that the removal of the center vortices from the
lattice configurations results in the loss of confinement. The running coupling
constant, the gluon and the ghost form factors are studied in Landau gauge for
both cases, the full and the vortex removed theory. In the latter case, a
strong suppression of the running coupling constant and the gluon form factor
at low momenta is observed. At the same time, the singularity of the ghost form
factor at vanishing momentum disappears. This observation establishes an
intimate correlation between the ghost singularity and confinement. The result
also shows that a removal of the vortices generates a theory for which
Zwanziger's horizon condition for confinement is no longer satisfied.Comment: 4 pages, 4 figure
Comparative study of gp130 cytokine effects on corticotroph AtT-20 cells - Redundancy or specificity of neuroimmunoendocrine modulators?
Objective: This comparative in vitro study examined the effects of all known gp130 cytokines on murine corticotroph AtT-20 cell function. Methods: Cytokines were tested at equimolar concentrations from 0.078 to 10 nM. Tyrosine phosphorylation of the signal transducer and activator of transcription ( STAT) 3 and STAT1, the STAT-dependent suppressor of cytokine signaling (SOCS)-3 promoter activity, SOCS-3 gene expression, STAT-dependent POMC promoter activity and adrenocorticotropic hormone ( ACTH) secretion were determined. Results: Leukemia inhibitory factor (LIF), human oncostatin M (OSM) and cardiotrophin (CT)-1 (LIFR/gp130 ligands), as well as ciliary neurotrophic factor ( CNTF) and novel neurotrophin1/B-cell stimulating factor-3 (CNTFRalpha/LIFR/gp130 ligands) are potent stimuli of corticotroph cells in vitro. In comparison, interleukin (IL)-6 (IL-6R/gp130 ligand) and IL-11 (IL-11R/gp130 ligand) exhibited only modest direct effects on corticotrophs, while murine OSM (OSMR/gp130 ligand) showed no effect. Conclusion: (i) CNTFR complex ligands are potent stimuli of corticotroph function, comparable to LIFR complex ligands; (ii) IL-6 and IL-11 are relatively weak direct stimuli of corticotroph function; (iii) differential effects of human and murine OSM suggest that LIFR/gp130 (OSMR type I) but not OSMR/gp130 (OSMR type II) are involved in corticotroph signaling. (iv) CT-1 has the hitherto unknown ability to stimulate corticotroph function, and (v) despite redundant immuno-neuroendocrine effects of different gp130 cytokines, corticotroph cells are preferably activated through the LIFR and CNTFR complexes. Copyright (C) 2004 S. Karger AG, Basel
Quark Contributions to Nucleon Momentum and Spin from Domain Wall fermion calculations
We report contributions to the nucleon spin and momentum from light quarks
calculated using dynamical domain wall fermions with pion masses down to 300
MeV and fine lattice spacing a=0.084 fm. Albeit without disconnected diagrams,
we observe that spin and orbital angular momenta of both u and d quarks are
opposite, almost canceling in the case of the d quark, which agrees with
previous calculations using a mixed quark action. We also present the full
momentum dependence of n=2 generalized form factors showing little variation
with the pion mass.Comment: 7 pages, 5 figures, NT-LBNL-11-020, MIT-CTP-4323. Presented at the
29th International Symposium on Lattice Field Theory (Lattice 2011), Squaw
Valley, California, 10-16 Jul 201
Bayesian Ordinal Quantile Regression with a Partially Collapsed Gibbs Sampler
Unlike standard linear regression, quantile regression captures the
relationship between covariates and the conditional response distribution as a
whole, rather than only the relationship between covariates and the expected
value of the conditional response. However, while there are well-established
quantile regression methods for continuous variables and some forms of discrete
data, there is no widely accepted method for ordinal variables, despite their
importance in many medical contexts. In this work, we describe two existing
ordinal quantile regression methods and demonstrate their weaknesses. We then
propose a new method, Bayesian ordinal quantile regression with a partially
collapsed Gibbs sampler (BORPS). We show superior results using BORPS versus
existing methods on an extensive set of simulations. We further illustrate the
benefits of our method by applying BORPS to the Fragile Families and Child
Wellbeing Study data to tease apart associations with early puberty among both
genders. Software is available at: GitHub.com/igrabski/borps
Nucleon Electromagnetic Form Factors from Lattice QCD using 2+1 Flavor Domain Wall Fermions on Fine Lattices and Chiral Perturbation Theory
We present a high-statistics calculation of nucleon electromagnetic form
factors in lattice QCD using domain wall quarks on fine lattices, to
attain a new level of precision in systematic and statistical errors. Our
calculations use lattices with lattice spacing a=0.084 fm for
pion masses of 297, 355, and 403 MeV, and we perform an overdetermined analysis
using on the order of 3600 to 7000 measurements to calculate nucleon electric
and magnetic form factors up to 1.05 GeV. Results are shown
to be consistent with those obtained using valence domain wall quarks with
improved staggered sea quarks, and using coarse domain wall lattices. We
determine the isovector Dirac radius , Pauli radius and
anomalous magnetic moment . We also determine connected contributions
to the corresponding isoscalar observables. We extrapolate these observables to
the physical pion mass using two different formulations of two-flavor chiral
effective field theory at one loop: the heavy baryon Small Scale Expansion
(SSE) and covariant baryon chiral perturbation theory. The isovector results
and the connected contributions to the isoscalar results are compared with
experiment, and the need for calculations at smaller pion masses is discussed.Comment: 44 pages, 40 figure
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