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Injury Patterns and Severity Among Hospitalized Motorcyclists: A Comparison of Younger and Older Riders

Dischinger, Patricia C.; Ryb, Gabriel E.; Ho, Shiu M.; Braver, Elisa R.
Fonte: Association for the Advancement of Automotive Medicine Publicador: Association for the Advancement of Automotive Medicine
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
26.05%
In recent years there has been a significant increase in mortality among motorcyclists, especially older riders (40+ years). However, few studies have compared the nature and severity of injuries sustained by older vs. younger cyclists. The purpose of this analysis was to determine differences, if any, in injury patterns to older vs. younger motorcyclists and to explore rider, vehicle, and environmental factors associated with these differences. Older riders were found to have a significantly higher incidence of thoracic injury, especially multiple thoracic injuries, and specifically multiple rib fractures. Older motorcyclists were also more likely to ride larger motorcycles, and were more involved in collisions involving overturning or striking highway structures. Large engine sizes were associated with increased risk of head and thoracic injuries, but not abdominal injuries. The magnitude of increased risks related to 1000+ cc engine size was higher among older motorcyclists than younger motorcyclists.

Abrupt climate change in the Atlantic Ocean during the last 20,000 years : insights from multi-element analysis of benthic and planktic foraminifera and coupled OA-GCM

Came, Rosemarie Evangeline
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 152 leaves
ENG
Relevância na Pesquisa
16.46%
Minor and trace element records of planktic and benthic foraminifera from Atlantic sediment cores, as well as output from a coupled OAGCM, were used to investigate the magnitude and distribution of the oceanic response to abrupt climate events of the past 20 kyr. The study addressed three major questions: 1) What is the magnitude of high-latitude sea surface temperature and salinity variability during abrupt climate events? 2) Does intermediate depth ventilation change in conjunction with high-latitude climate variability? 3) Are the paleoclimate data consistent with the response of a coupled OAGCM to a freshwater perturbation? To address these questions, analytical methods were implemented for the simultaneous measurement of Mg/Ca, Zn/Ca, Cd/Ca, Mn/Ca and Al/Ca in foraminiferal samples using inductively-coupled plasma mass spectrometry. Paired records of planktic foraminiferal [delta]¹⁸O and Mg/Ca from the subpolar North Atlantic reveal trends of increasing temperatures ([approx.] 3⁰C) and salinities over the course of the Holocene, which were punctuated by abrupt events. The variability does not appear to be periodic, but tends to recur within a broad millennial band. The records provide the first evidence of open-ocean cooling (nearly 2⁰C) and freshening during the 8.2 kyr event...

Modelagem da estabilidade de tratores agrícolas de pneus.

KHOURY JUNIOR, J.K.; DIAS, G.P.; CORDEIRO, R.R.; SOUZA, C.M.A. de
Fonte: Pesquisa Agropecuária Brasileira, Brasília, DF, v. 39, n. 5, p. 459-468, maio 2004. Publicador: Pesquisa Agropecuária Brasileira, Brasília, DF, v. 39, n. 5, p. 459-468, maio 2004.
Tipo: Artigo em periódico indexado (ALICE)
PT_BR
Relevância na Pesquisa
26.05%
O conhecimento do limite de estabilidade de tratores é fundamental à segurança das operações agrícolas. O objetivo deste trabalho foi desenvolver um modelo matemático para previsão da perda da estabilidade de tratores agrícolas. No modelo foram utilizadas as características geométricas e ponderais do trator e de sua condição numa pista de ensaio. Análises de balanço de forças e de momentos foram realizadas para determinar as equações que regem o comportamento estático e dinâmico do trator em superfície inclinada. Com base nos resultados da comparação entre os valores dos ângulos-limite de tombamento simulados e experimentais, conclui-se que o modelo matemático desenvolvido é capaz de prever a perda da estabilidade de trator 4x2 satisfatoriamente.; 2004

Hard scattering and QCD Fundamentals at RHIC

Tannenbaum, M. J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/06/2008
Relevância na Pesquisa
16.18%
In 1998, at the 4th QCD workshop, Rolf Baier asked me whether jets could be measured in Au+Au collisions because he had a prediction of a QCD medium-effect (energy loss via soft gluon radiation induced by multiple scattering) on color-charged partons traversing a hot-dense-medium composed of screened color-charges. I reviewed the possibilities in a talk explaining that there was a general consensus that for Au+Au central collisions at $\sqrt{s_{NN}}=200$ GeV, leading particles are the only way to find jets because of the large particle density. The good news was that hard-scattering in p-p collisions was originally observed by the method of leading particles and that these techniques could be used to study hard-scattering and jets in Au+Au collisions. Notably, I described ``How everything you want to know about jets can be found using 2-particle correlations''. In fact, the predicted ``jet quenching'' and other new phenomena were discovered by this method. However, this past year, I had to soften the statement to {\em almost everything} because we found by explicit calculation in PHENIX that the away-side two-particle correlation $p_{T_a}$ spectrum from a $\pi^0$ trigger with $p_{T_t}$ is not sensitive to the fragmentation function--overturning a belief dating from the seminal paper of Feynman...

Lateral downflows in sunspot penumbral filaments and their temporal evolution

Pozuelo, S. Esteban; Rubio, L. R. Bellot; Rodriguez, J. de la Cruz
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
16.18%
We study the temporal evolution of downflows observed at the lateral edges of penumbral filaments in a sunspot located very close to the disk center. Our analysis is based on a sequence of nearly diffraction-limited scans of the Fe I 617.3 nm line taken with the CRisp Imaging Spectro-Polarimeter at the Swedish 1 m Solar Telescope. We compute Dopplergrams from the observed intensity profiles using line bisectors and filter the resulting velocity maps for subsonic oscillations. Lateral downflows appear everywhere in the center-side penumbra as small, weak patches of redshifts next to or along the edges of blueshifted flow channels. These patches have an intermittent life and undergo mergings and fragmentations quite frequently. The lateral downflows move together with the hosting filaments and react to their shape variations, very much resembling the evolution of granular convection in the quiet Sun. There is a good relation between brightness and velocity of the flow structures in the center-side penumbra, with downflows being darker than upflows on average, which is again reminiscent of quiet Sun convection. These results point to the existence of overturning convection in sunspot penumbrae, with elongated cells forming filaments where the flow is upward but very inclined...

Convection in Binary Fluid Mixtures. I. Extended Traveling Wave and Stationary States. (Physical Review E, in press)

Barten, W.; Luecke, M.; Kamps, M.; Schmitz, R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/04/1995
Relevância na Pesquisa
16.05%
Nonlinear convection structures are investigated in quantitative detail as a function of Rayleigh number for several negative and positive Soret coupling strengths (separation ratios) and different Lewis and Prandtl numbers characterizing different mixtures. A finite difference method was used to solve the full hydrodynamic field equations in a range of experimentally accessible parameters. We elucidate the important role that the concentration field plays in the nonlinear states of stationary overturning convection (SOC) and of traveling wave (TW) convection. Structural differences in the concentration boundary layers and of the concentration plumes in TW's and SOC's and their physical consequences are discussed. These properties show that the states con- sidered here are indeed strongly nonlinear, as expected from the magnitude of advection and diffusion in the concentration balance. The bifurcation behaviour of the states is analysed using different order parameters such as flow intensity, Nusselt number, a newly defined mixing parameter characterized by the variance of the concentration field, and the TW frequency. For further comparison with experiments, light intensity distributions are determined that can be observed in side-view shadowgraphs. Structural analyses of all fields are made using colour coded isoplots...