University of Iowa

About: University of Iowa is a education organization based out in Iowa City, Iowa, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 49229 authors who have published 109171 publications receiving 5021465 citations. The organization is also known as: UI & The University of Iowa.

Observation and studies of jet quenching in PbPb collisions at √sNN=2.76 TeV

Abstract: Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.

Bullying in schools: Perspectives on understanding and preventing an international problem.

Abstract: Bullying is a problem which is receiving increasing attention worldwide. Researchers in several countries have already devised and implemented bullying intervention/prevention programs on a nation-wide basis. Data from large-scale trials of comprehensive, school-wide programs indicate that when used as a long-term ongoing solution rather than a 'quick fix' in crisis situations, bullying behaviour can be reduced significantly. This article examines terminology, background, developmental aspects and myths about bullying. Psychosocial characteristics of and implications for bullies and victims are discussed. Four bullying interventions are summarized and reviewed, and the main findings indicate everyone must shoulder the responsibility of putting an end to bullying behaviour.

Confirmatory factor analyses of posttraumatic stress symptoms in deployed and nondeployed veterans of the Gulf War.

Abstract: Confirmatory factor analysis was used to compare 6 models of posttraumatic stress disorder (PTSD) symptoms, ranging from 1 to 4 factors, in a sample of 3,695 deployed Gulf War veterans (N = 1,896) and nondeployed controls (N = 1,799) The 4 correlated factors-intrusions, avoidance, hyperarousal, and dysphoria-provided the best fit The dysphoria factor combined traditional markers of numbing and hyperarousal Model superiority was cross-validated in multiple subsamples, including a subset of deployed participants who were exposed to traumatic combat stressors Moreover, convergent and discriminant validity correlations suggested that intrusions may be relatively specific to PTSD, whereas dysphoria may represent a nonspecific component of many disorders Results are discussed in the context of hierarchical models of anxiety and depression

Kinetics of nitrate, nitrite, and Cr(VI) reduction by iron metal.

Abstract: The kinetics of nitrate, nitrite, and Cr(VI) reduction by three types of iron metal (Fe0) were studied in batch reactors for a range of Fe0 surface area concentrations and solution pH values (5.5−9.0). At pH 7.0, there was only a modest difference (2−4×) in first-order rate coefficients (kobs) for each contaminant among the three Fe0 types investigated (Fisher, Peerless, and Connelly). The kobs values at pH 7.0 for both nitrite and Cr(VI) reduction were first-order with respect to Fe0 surface area concentration, and average surface area normalized rate coefficients (kSA) of 9.0 × 10-3 and 2.2 × 10-1 L m-2 h-1 were determined for nitrite and Cr(VI), respectively. Unlike nitrite and Cr(VI), Fe0 surface area concentration had little effect on rates of nitrate reduction (with the exception of Connelly Fe0, which reduced nitrate at slower rates at higher Fe0 surface areas). The rates of nitrate, nitrite, and Cr(VI) reduction by Fisher Fe0 decreased with increasing pH with apparent reaction orders of 0.49 ± 0.0...