University of California, Davis

About: University of California, Davis is a education organization based out in Davis, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 78770 authors who have published 180033 publications receiving 8064158 citations. The organization is also known as: UC Davis & UCD.

Interspecific Killing among Mammalian Carnivores

Abstract: Interspecific killing among mammalian carnivores is common in nature and accounts for up to 68% of known mortalities in some species. Interactions may be symmetrical (both species kill each other) or asymmetrical (one species kills the other), and in some interactions adults of one species kill young but not adults of the other. There is a positive significant relationship between the body masses of solitary killer species and body masses of their victim species, and grouping species kill larger victims than solitary species. Interactions and consumption of the victim appear more common when food is scarce or disputed. In response to killers, victim species may alter their use of space, activity patterns, and form groups. Consequences of interspecific killing include population reduction or even extinction, and reduction and enhancement of prey populations, and may therefore have important implications for conservation and management of carnivores and their prey.

Anterior cingulate cortex and conflict detection: an update of theory and data.

Abstract: The dorsal anterior cingulate cortex (ACC) and associated regions of the medial frontal wall have often been hypothesized to play an important role in cognitive control. We have proposed that the ACC's specific role in cognitive control is to detect conflict between simultaneously active, competing representations and to engage the dorsolateral prefrontal cortex (DLPFC) to resolve such conflict. Here we review some of the evidence supporting this theory, from event-related potential (ERP) and fMRI studies. We focus on data obtained from interference tasks, such as the Stroop task, and review the evidence that trial-to-trial changes in control engagement can be understood as driven by conflict detection; the data suggest that levels of activation of the ACC and the DLPFC in such tasks do indeed reflect conflict and control, respectively. We also discuss some discrepant results in the literature that highlight the need for future research.

Placebo-controlled phase 3 trial of a recombinant glycoprotein 120 vaccine to prevent HIV-1 infection.

Abstract: Background A vaccine is needed to prevent human immunodeficiency virus type 1 (HIV-1) infection. Methods A double-blind, randomized trial of a recombinant HIV-1 envelope glycoprotein subunit (rgp120) vaccine was conducted among men who have sex with men and among women at high risk for heterosexual transmission of HIV-1. Volunteers received 7 injections of either vaccine or placebo (ratio, 2 : 1) over 30 months. The primary end point was HIV-1 seroconversion over 36 months. Results A total of 5403 volunteers (5095 men and 308 women) were evaluated. The vaccine did not prevent HIV-1 acquisition: infection rates were 6.7% in 3598 vaccinees and 7.0% in 1805 placebo recipients; vaccine efficacy (VE) was estimated as 6% (95% confidence interval, -17% to 24%). There were no significant differences in viral loads, rates of antiretroviral-therapy initiation, or the genetic characteristics of the infecting HIV-1 strains between treatment arms. Exploratory subgroup analyses showed nonsignificant trends toward efficacy in preventing infection in the highest risk (VE, 43%; n=247) and nonwhite (VE, 47%; n=914) volunteers (P=.10, adjusted for multiple subgroup comparisons). Conclusions There was no overall protective effect. The efficacy trends in subgroups may provide clues for the development of effective immunization approaches.

Involvement in traditional and electronic bullying among adolescents.

Abstract: The increasing availability of Internet and cell phones has provided new avenues through which adolescents can bully. Electronic bullying is a new form of bullying that may threaten adolescent social and emotional development. In this study the relation between involvement in electronic and traditional bullying was examined. Eighty-four adolescents completed questionnaires regarding their involvement in traditional and electronic bullying. Results show that students' roles in traditional bullying predicted the same role in electronic bullying. Also, being a victim of bullying on the Internet or via text messages was related to being a bully at school. Traditional victims were not found to be electronic bullies. Perceptions of the effects of and motivations for electronic bullying are discussed.

Domestic Saving and International Capital Flows Reconsidered

Abstract: A long literature since Feldstein and Horioka's seminal contribution documents the strong correlation of domestic saving and investment rates since the 1960s. According to conventional wisdom, the result provides evidence of international capital market imperfections. The macroeconomic theory of small open economies prescribes a relationship between the composition of aggregate demand and its relative price structure, a linkage hitherto ignored in the saving-investment literature. Theory and evidence also suggest a role for growth and demographic effects, well known in previous studies. If one controls for these effects, the standard correlation of saving and investment disappears. International capital markets may be better integrated than once thought, and the former correlations may have been spurious. The pattern of domestic investment rates is better explained by domestic price distortions and other variables than by domestic saving constraints.