Predictores de la agresión en videojuegos de consola

This study was designed to investigate the aggression levels of college students found in the Northeastern part of the United States following exposure to video games. The 59 participants played their assigned game, Mortal Kombat on Nintendo Wii or Halo 2 on the Xbox, for 45 minutes with a partner. The researchers employed twelve t-tests (alpha adjusted to .004) and three multiple linear regressions to explore the difference of aggression levels in gender, violent video game, and predictors of aggression. Results showed no aggression differences in all twelve t-tests for the three aggression variables (physical, verbal, and general) pre and post-tests for gender or violent video game played. Additionally, there was no support found suggesting the violent video games, gender, and time spent playing video games caused aggression as previously touted by past researchers. In fact, the only significance found for predicting aggression were the pre-aggression scores in all three areas of measured aggression suggesting a need for proper control of variables and that aggression may be preexisting within the individual rather than caused by violent video game play.Este estudio fue diseñado para investigar los niveles de agresión en estudiantes universitarios de la región noreste de los Estados Unidos después de la exposición a videojuegos. 59 participantes jugaron a un videojuego asignado, Mortal Kombat en Nintendo Wii o Halo 2 en Xbox, durante 45 minutos con un compañero. Se emplearon doce pruebas t (alfa ajustado a 0.004) y tres regresiones lineales múltiples para explorar la diferencia de niveles de agresión en género, videojuegos violentos y predictores de la agresión. Los resultados no mostraron diferencias en agresión a lo largo de las doce pruebas t para las tres variables de agresión (física, verbal y general) pre y post-tests para género o videojuego violento jugado. Además, no se halló soporte sugiriendo que los videojuegos violentos, el género y el tiempo dedicado a jugar videojuegos causen agresión. De hecho, el único resultado significativo encontrado para predecir la agresión fueron las puntuaciones pre-agresión en las tres áreas medidas, sugiriendo la necesidad de un control adecuado de las variables y que la agresión puede ser pre-existente en el individuo y no causada por videojuegos violentos

Implementing a network for electronic surveillance reporting from public health reference laboratories: an international perspective.

Electronic data reporting from public health laboratories to a central site provides a mechanism for public health officials to rapidly identify problems and take action to prevent further spread of disease. However, implementation of reference laboratory systems is much more complex than simply adopting new technology, especially in international settings. We describe three major areas to be considered by international organizations for successful implementation of electronic reporting systems from public health reference laboratories: benefits of electronic reporting, planning for system implementation (e.g., support, resources, data analysis, country sovereignty), and components of system initiation (e.g., authority, disease definition, feedback, site selection, assessing readiness, problem resolution). Our experience with implementation of electronic public health laboratory data management and reporting systems in the United States and working with international organizations to initiate similar efforts demonstrates that successful reference laboratory reporting can be implemented if surveillance issues and components are planned

Spectroscopic binaries in the Solar Twin Planet Search program: from substellar-mass to M dwarf companions

Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young stars converge towards a well-defined evolution that follows a power-law decay. It seems, however, that some binary stars do not obey this relation, often by displaying enhanced rotational rates and activity. In the Solar Twin Planet Search program we observed several solar twin binaries, and found a multiplicity fraction of $42\% \pm 6\%$ in the whole sample; moreover, at least three of these binaries (HIP 19911, HIP 67620 and HIP 103983) clearly exhibit the aforementioned anomalies. We investigated the configuration of the binaries in the program, and discovered new companions for HIP 6407, HIP 54582, HIP 62039 and HIP 30037, of which the latter is orbited by a $0.06$ M$_\odot$ brown dwarf in a 1-month long orbit. We report the orbital parameters of the systems with well-sampled orbits and, in addition, the lower limits of parameters for the companions that only display a curvature in their radial velocities. For the linear trend binaries, we report an estimate of the masses of their companions when their observed separation is available, and a minimum mass otherwise. We conclude that solar twin binaries with low-mass stellar companions at moderate orbital periods do not display signs of a distinct rotational evolution when compared to single stars. We confirm that the three peculiar stars are double-lined binaries, and that their companions are polluting their spectra, which explains the observed anomalies.Comment: 13 pages, 7 figures, accepted for publication in MNRA

The temporal evolution of neutron-capture elements in the Galactic discs

Important insights into the formation and evolution of the Galactic disc(s) are contained in the chemical compositions of stars. We analysed high-resolution and high signal to noise HARPS spectra of 79 solar twin stars in order to obtain precise determinations of their atmospheric parameters, ages ($\sigma$$\sim$0.4 Gyr) and chemical abundances ($\sigma$$<$0.01~dex) of 12 neutron-capture elements (Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, and Dy). This valuable dataset allows us to study the [X/Fe]-age relations over a time interval of $\sim$10 Gyr and among stars belonging to the thin and thick discs. These relations show that i) the $s$-process has been the main channel of nucleosynthesis of $n$-capture elements during the evolution of the thin disc; ii) the thick disc is rich in $r$-process elements which suggests that its formation has been rapid and intensive. %; iii) a chemical continuity between the thin and thick discs is evident in the abundances of Ba. In addition, the heavy (Ba, La, Ce) and light (Sr, Y, Zr) $s$-process elements revealed details on the dependence between the yields of AGB stars and the stellar mass or metallicity. Finally, we confirmed that both [Y/Mg] and [Y/Al] ratios can be employed as stellar clocks, allowing ages of solar twin stars to be estimated with an average precision of $\sim$0.5~Gyr

Constraining the evolution of stellar rotation using solar twins

The stellar Rotation $vs.$ Age relation is commonly considered as a useful tool to derive reliable ages for Sun-like stars. However, in the light of \kepler\ data, the presence of apparently old and fast rotators that do not obey the usual gyrochronology relations led to the hypothesis of weakened magnetic breaking in some stars. In this letter, we constrain the solar rotation evolutionary track using solar twins. Predicted rotational periods as a function of mass, age, [Fe/H] and given critical Rossby number ($Ro_{\rm crit}$) were estimated for the entire rotational sample. Our analysis favors the smooth rotational evolution scenario and suggests that, if the magnetic weakened breaking scenario takes place at all, it should arise after $Ro_{\rm crit}\gtrsim2.29$ or ages $\gtrsim$5.3 Gyr (at 95$\%$ confidence level).Comment: 5 pages, 3 figures, accepted for publication in MNRA

Hispanic Familism Reconsidered

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93710/1/tsq1252.pd

Functional Properties and Toxin Pharmacology of a Dorsal Root Ganglion Sodium Channel Viewed through its Voltage Sensors

The voltage-activated sodium (Nav) channel Nav1.9 is expressed in dorsal root ganglion (DRG) neurons where it is believed to play an important role in nociception. Progress in revealing the functional properties and pharmacological sensitivities of this non-canonical Nav channel has been slow because attempts to express this channel in a heterologous expression system have been unsuccessful. Here, we use a protein engineering approach to dissect the contributions of the four Nav1.9 voltage sensors to channel function and pharmacology. We define individual S3b–S4 paddle motifs within each voltage sensor, and show that they can sense changes in membrane voltage and drive voltage sensor activation when transplanted into voltage-activated potassium channels. We also find that the paddle motifs in Nav1.9 are targeted by animal toxins, and that these toxins alter Nav1.9-mediated currents in DRG neurons. Our results demonstrate that slowly activating and inactivating Nav1.9 channels have functional and pharmacological properties in common with canonical Nav channels, but also show distinctive pharmacological sensitivities that can potentially be exploited for developing novel treatments for pain

Primary structure and functional expression of a high voltage activated calcium channel from rabbit lung

The complete amino acid sequence of the receptor for organic calcium channel blockers (CaCB) from rabbit lung has been deduced by cloning and sequence analysis of the cDNA. Synthetic RNA derived from this cDNA induces the formation of a functional CaCB-sensitive high voltage activated calcium channel in Xenopus oocytes