Media Violence Effects on Brain Development: What Neuroimaging Has Revealed and What Lies Ahead

Substantial research has indicated that media violence induces both short- and long-term increases in aggressive thoughts, feelings, and behaviors. Recently, neuroimaging techniques have begun to identify the mechanisms driving these changes. An important avenue that these neuroimaging tools can address is how exposure to media violence in childhood affects brain development, which can have lifelong behavioral consequences. This review highlights neuroimaging research examining how media violence exposure affects the pediatric brain. While such research is limited, evidence suggests that prefrontal mechanisms for controlling emotion and behavior are altered by exposure to violent media. Therefore, long-term increases in aggression and decreases in inhibitory control due to excessive media violence exposure may result from impaired development of prefrontal regions. However, additional neuroimaging research is necessary to establish whether and how exposure to media violence specifically shapes subsequent neural maturation. To optimize the use of neuroimaging in this inquiry, imaging studies should not stand on their own, but instead must be integrated with more traditional research paradigms to establish a more complete picture of effects. Future research must employ more longitudinal approaches to better characterize long-term effects that high exposure to violent screen media may have on brain development, particularly prefrontal and limbic brain regions

Simulation modeling and preliminary analysis of TIMS data from the Carlin area and the northern Grapevine Mountains, Nevada

A theoretical radiance model was employed together with laboratory data on a suite of igneous rock to evaluate various algorithms for processing Thermal Infrared Multispectral Scanner (TIMS) data. Two aspects of the general problem were examined: extraction of emissivity information from the observed TIMS radiance data, and how to use emissivity data in a way that is geologically meaningful. The four algorithms were evaluated for appropriate band combinations of TIMS data acquired on both day and night overflights of the Tuscarora Mountains, including the Carlin gold deposit, in north-central Nevada. Analysis of a color composited PC decorrelated image (Bands 3, 4, 5--blue/green/red) of the Northern Grapevine Mountains, Nevada, area showed some useful correlation with the regional geology. The thermal infrared region provides fundamental spectral information that can be used to discriminate the major rock types occurring on the Earth's surface

Molecular Realism in Default Models for Information Theories of Hydrophobic Effects

This letter considers several physical arguments about contributions to hydrophobic hydration of inert gases, constructs default models to test them within information theories, and gives information theory predictions using those default models with moment information drawn from simulation of liquid water. Tested physical features include: packing or steric effects, the role of attractive forces that lower the solvent pressure, and the roughly tetrahedral coordination of water molecules in liquid water. Packing effects (hard sphere default model) and packing effects plus attractive forces (Lennard-Jones default model) are ineffective in improving the prediction of hydrophobic hydration free energies of inert gases over the previously used Gibbs and flat default models. However, a conceptually simple cluster Poisson model that incorporates tetrahedral coordination structure in the default model is one of the better performers for these predictions. These results provide a partial rationalization of the remarkable performance of the flat default model with two moments in previous applications. The cluster Poisson default model thus will be the subject of further refinement.Comment: 5 pages including 3 figure

Educational attainment and the clustering of health-related behavior among U.S. young adults

We documented health-related behavior clustering among US young adults and assessed the extent to which educational attainment was associated with the identified clusters. Using data from Wave IV of the National Longitudinal Study of Adolescent to Adult Health (Add Health), we performed latent class analysis on 8 health-related behaviors (n = 14,338), documenting clustering of behavior separately by gender. Subsequently, we used multinomial logistic regression and estimated associations between educational attainment and the health-related behavior clusters. Twenty-eight percent of young women grouped into the most favorable health behavior cluster, while 22 percent grouped into a very high-risk cluster. A larger percentage of young men (40 percent) grouped into the highest risk cluster. Individuals with educational attainment at the college and advanced degree levels exhibited much lower risk of being in the unhealthy behavioral clusters than individuals with lower educational attainment, net of a range of confounders. Substantial fractions of US young adults, particularly those with less than college degrees, exhibit unhealthy behavior profiles. Efforts to improve health among young adults should focus particular attention on the clustering of poor health-related behavior, especially among individuals who have less than a college degree

Racial Disparities in Functional Limitations Among Hispanic Women in the United States

This paper assesses whether there are race differences in functional health among Hispanic women in the United States; ascertains whether the race differences in functional health vary by age; and examines the extent to which race differences in functional health are attributable to key dimensions of demographic, geographic, and socioeconomic heterogeneity. The analysis is based on 15 years of aggregated data from the National Health Interview Survey. Both U.S.- and foreign-born black and other race Hispanic women display a higher level of functional limitations than their white Hispanic counterparts. There is little evidence that such health differences widen with age. U.S.-born black Hispanic women, however, suffer from a high burden of functional limitations across the adult age range. This research speaks to the need for greater attention to racial differences in health among Hispanics, and particularly so within the U.S.-born segment of this rapidly aging population

Scattered Lyman-alpha Radiation Around Sources Before Cosmological Reionization

The spectra of the first galaxies and quasars in the Universe should be strongly absorbed shortward of their rest-frame Lyman-alpha wavelength by neutral hydrogen (HI) in the intervening intergalactic medium. However, the Lyman-alpha line photons emitted by these sources are not eliminated but rather scatter until they redshift out of resonance and escape due to the Hubble expansion of the surrounding intergalactic HI. We calculate the resulting brightness distribution and the spectral shape of the diffuse Lyman-alpha line emission around high redshift sources, before the intergalactic medium was reionized. Typically, the Lyman-alpha photons emitted by a source at z=10 scatter over a characteristic angular radius of order 15 arcseconds around the source and compose a line which is broadened and redshifted by about a thousand km/s relative to the source. The scattered photons are highly polarized. Detection of the diffuse Lyman-alpha halos around high redshift sources would provide a unique tool for probing the neutral intergalactic medium before the epoch of reionization. On sufficiently large scales where the Hubble flow is smooth and the gas is neutral, the Lyman-alpha brightness distribution can be used to determine the cosmological mass densities of baryons and matter.Comment: 21 pages, 5 Postscript figures, accepted by ApJ; figures 1--3 corrected; new section added on the detectability of Lyman alpha halos; conclusions update