6,563 research outputs found
Decifrando o genoma em grande escala.
A determinação das funções gêni~~stem de~andado um grande avanço das ciências genômicas, cujas tecnologias concentram-se, principalmente, na geração e no estudo de uma grande quantidade de dados. O ponto de apoio para o entendimento da função gênica e da estrutura do genoína tem sido o sequenciamento de genomas completos e do genoma expresso em grande escala. Mapas físicos e genéticos têm sido integrados com informações genôrnicas e de expressão, resultando em bancos de dados públicos altamente informativos para diferentes espécies animais evegetais. Tais informações auxiliam em vários aspectos a análise·de expressão gênica, a determinação dos efeitos de processamento de éxons.e do número de cópias gênicas e cromossômicas, culminando na determinação das funções biológicas e do mecanismo de ação de vários genes. São descritos o surgimento de novas tecnologias e a evolução de algumas inovações já existentes, voltadas para a identificação de funções gênicas
Are the effects of unreal violent videogames pronounced when playing with a virtual reality system?
This study was conducted to analyze the short-term effects of violent electronic games, played with or without a virtual reality (VR) device, on the instigation of aggressive behavior. Physiological arousal (heart rate (HR)), priming of aggressive thoughts, and state hostility were also measured to test their possible mediation on the relationship between playing the violent game (VG) and aggression. The participants—148 undergraduate students—were randomly assigned to four treatment conditions: two groups played a violent computer game (Unreal Tournament), and the other two a non-violent game (Motocross Madness), half with a VR device and the remaining participants on the computer screen. In order to assess the game effects the following instruments were used: a BIOPAC System MP100 to measure HR, an Emotional Stroop task to analyze the priming of aggressive and fear thoughts, a self-report State Hostility Scale to measure hostility, and a competitive reaction-time task to assess aggressive behavior. The main results indicated that the violent computer game had effects on state hostility and aggression. Although no significant mediation effect could be detected, regression analyses showed an indirect effect of state hostility between playing a VG and aggressio
Improving Access and Quality in Early Childhood Development Programs: Experimental Evidence from The Gambia
We evaluate two experiments of early childhood development (ECD) programs in The Gambia: one increasing access to services, and another improving service quality. In the first experiment, new community-based ECD centers were introduced to randomly chosen villages that had no pre-existing structured ECD services. In the second experiment, a randomly assigned subset of existing ECD centers received intensive provider training. We find no evidence that either intervention improved average levels of child development. Exploratory analysis suggests that the first experiment, which increased access to community-based ECD services, led to declines in child development among children from less disadvantaged households
Evidence of Two Distinct Dynamic Critical Exponents in Connection with Vortex Physics
The dynamic critical exponent is determined from numerical simulations
for the three-dimensional (3D) lattice Coulomb gas (LCG) and the 3D XY models
with relaxational dynamics. It is suggested that the dynamics is characterized
by two distinct dynamic critical indices and related to the
divergence of the relaxation time by and
, where is the correlation length and the
wavevector. The values determined are and for the
3D LCG and and for the 3D XY model. It is argued
that the nonlinear exponent relates to , whereas the usual
Hohenberg-Halperin classification relates to . Possible implications for the
interpretation of experiments are pointed out. Comparisons with other existing
results are discussed.Comment: to appear in PR
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