247 research outputs found
Mass Shootings and Public Support for Gun Control
The recent spate of mass public shootings in the United States raises important questions about how these tragic events might impact mass opinion and public policy. Integrating research on focusing events, contextual effects and perceived threat, this article stipulates that residing near a mass shooting should increase support for gun control by making the threat of gun violence more salient. Drawing upon multiple data sources on mass public shootings paired with large-N survey data, it demonstrates that increased proximity to a mass shooting is associated with heightened public support for stricter gun control. Importantly, the results show that this effect does not vary by partisanship, but does vary as a function of salience-related event factors, such as repetition, magnitude and recency. Critically, the core result is replicated using panel data. Together, these results suggest a process of context-driven policy feedback between existing gun laws, egregious gun violence and demand for policy change
Foreign language exposure, cultural threat, and opposition to immigration
In the present article, we extend the notion of cultural threat posed by immigrants beyond its current conceptualization as symbolic, collective-level threats to American culture and identity. Instead, we argue that routine encounters with non-English-speaking immigrants cause many individuals to feel threatened because of real barriers to interpersonal communication and exchange. We draw upon survey and experimental data to demonstrate that local contact with immigrants who speak little to no English, as well as incidental exposure to the Spanish language, heighten feelings of cultural threat, which increases anti-immigrant sentiment and policy preferences
Social dominance and the cultural politics of immigration.
We argue that conflict over immigration largely concerns who bears the burden of cultural transaction costs, which we define as the costs associated with overcoming cultural barriers (e.g., language) to social exchange. Our framework suggests that the ability of native-born citizens to push cultural transaction costs onto immigrant out-groups serves as an important expression of social dominance. In two novel studies, we demonstrate that social dominance motives condition emotional responses to encountering cultural transaction costs, shape engagement in cultural accommodation behavior toward immigrants, and affect immigration attitudes and policy preferences
Gravitational waves from rapidly rotating neutron stars
Rapidly rotating neutron stars in Low Mass X-ray Binaries have been proposed
as an interesting source of gravitational waves. In this chapter we present
estimates of the gravitational wave emission for various scenarios, given the
(electromagnetically) observed characteristics of these systems. First of all
we focus on the r-mode instability and show that a 'minimal' neutron star model
(which does not incorporate exotica in the core, dynamically important magnetic
fields or superfluid degrees of freedom), is not consistent with observations.
We then present estimates of both thermally induced and magnetically sustained
mountains in the crust. In general magnetic mountains are likely to be
detectable only if the buried magnetic field of the star is of the order of
G. In the thermal mountain case we find that gravitational
wave emission from persistent systems may be detected by ground based
interferometers. Finally we re-asses the idea that gravitational wave emission
may be balancing the accretion torque in these systems, and show that in most
cases the disc/magnetosphere interaction can account for the observed spin
periods.Comment: To appear in 'Gravitational Waves Astrophysics: 3rd Session of the
Sant Cugat Forum on Astrophysics, 2014', Editor: Carlos F. Sopuert
Tunneling Time Distribution by means of Nelson's Quantum Mechanics and Wave-Particle Duality
We calculate a tunneling time distribution by means of Nelson's quantum
mechanics and investigate its statistical properties. The relationship between
the average and deviation of tunneling time suggests the exsistence of
``wave-particle duality'' in the tunneling phenomena.Comment: 14 pages including 11 figures, the text has been revise
Accuracy and Stability of Computing High-Order Derivatives of Analytic Functions by Cauchy Integrals
High-order derivatives of analytic functions are expressible as Cauchy
integrals over circular contours, which can very effectively be approximated,
e.g., by trapezoidal sums. Whereas analytically each radius r up to the radius
of convergence is equal, numerical stability strongly depends on r. We give a
comprehensive study of this effect; in particular we show that there is a
unique radius that minimizes the loss of accuracy caused by round-off errors.
For large classes of functions, though not for all, this radius actually gives
about full accuracy; a remarkable fact that we explain by the theory of Hardy
spaces, by the Wiman-Valiron and Levin-Pfluger theory of entire functions, and
by the saddle-point method of asymptotic analysis. Many examples and
non-trivial applications are discussed in detail.Comment: Version 4 has some references and a discussion of other quadrature
rules added; 57 pages, 7 figures, 6 tables; to appear in Found. Comput. Mat
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4Ă10-5 and 9.4Ă10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
All-sky search for long-duration gravitational wave transients with initial LIGO
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4Ă10-5 and 9.4Ă10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society
Self-control interventions for children under age 10 for improving self-control and delinquency and problem behaviors
Self-control improvement programs are intended to serve many purposes, most
notably improving self-control. Yet, interventions such as these often aim to reduce
delinquency and problem behaviors. However, there is currently no summary
statement available regarding whether or not these programs are effective in
improving self-control and reducing delinquency and problem behaviors. The main objective of this review is to assess the available research evidence on the
effect of self-control improvement programs on self-control and delinquency and
problem behaviors. In addition to investigating the overall effect of early selfcontrol
improvement programs, this review will examine, to the extent possible, the
context in which these programs may be most successful. The studies included in this systematic review indicate that self-control
improvement programs are an effective intervention for improving self-control and
reducing delinquency and problem behaviors, and that the effect of these programs
appears to be rather robust across various weighting procedures, and across context,
outcome source, and based on both published and unpublished data
Subcortical volumes across the lifespan: data from 18,605 healthy individuals aged 3-90 years
Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to examine age-related trajectories inferred from cross-sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3-90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter-individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age-related morphometric patterns.Education and Child Studie
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