RESUMEN
A measurement of two-particle correlations with a high transverse momentum trigger particle (p(T)(trig) > 2.5 GeV/c) is presented for Au+Au collisions at square root(s(NN)) = 200 GeV over the uniquely broad longitudinal acceptance of the PHOBOS detector (-4 < Delta eta < 2). A broadening of the away-side azimuthal correlation compared to elementary collisions is observed at all Delta eta. As in p+p collisions, the near side is characterized by a peak of correlated partners at small angle relative to the trigger particle. However, in central Au+Au collisions an additional correlation extended in Delta eta and known as the "ridge" is found to reach at least |Delta eta| approximately = 4. The ridge yield is largely independent of Delta eta over the measured range, and it decreases towards more peripheral collisions. For the chosen (p(T)(trig) cut, the ridge yield is consistent with zero for events with less than roughly 100 participating nucleons.
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This Letter presents the first measurement of event-by-event fluctuations of the elliptic flow parameter v(2) in Au+Au collisions at square root(s(NN))=200 GeV as a function of collision centrality. The relative nonstatistical fluctuations of the v(2) parameter are found to be approximately 40%. The results, including contributions from event-by-event elliptic flow fluctuations and from azimuthal correlations that are unrelated to the reaction plane (nonflow correlations), establish an upper limit on the magnitude of underlying elliptic flow fluctuations. This limit is consistent with predictions based on spatial fluctuations of the participating nucleons in the initial nuclear overlap region. These results provide important constraints on models of the initial state and hydrodynamic evolution of relativistic heavy ion collisions.
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The American College of Obstetricians and Gynecologists, since its beginning established three main objectives: 1. Education of physicians, 2. Education for patients, 3. To improve health care for women. The time has confirmed that through its programs the following has been reached: 1. Diminution in maternal mortality, 2. Diminution in newborn mortality, 3. Diminution in cervical cancer. The following is recommended: Exercise, adequate diet, evaluation tests, early diagnosis, hormonal therapy when recommended by the physician, for a prolonged, healthier, and more productive life.
Asunto(s)
Ginecología/educación , Obstetricia/educación , Educación del Paciente como Asunto , Servicios de Salud para Mujeres , Salud de la Mujer , Adolescente , Adulto , Femenino , Humanos , Mortalidad Infantil , Recién Nacido , Mortalidad Materna , México , Persona de Mediana Edad , Embarazo , Complicaciones del Embarazo/prevención & control , Garantía de la Calidad de Atención de SaludAsunto(s)
Empatía , Ginecología/normas , Obstetricia/normas , Filosofía Médica , Femenino , Humanos , Relaciones Médico-Paciente , Estados UnidosRESUMEN
We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, sqrt[s_{NN}]=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N{part}/2A rather than the same N_{part}. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.
RESUMEN
This Letter presents measurements of the elliptic flow of charged particles as a function of pseudorapidity and centrality from Cu-Cu collisions at 62.4 and 200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The elliptic flow in Cu-Cu collisions is found to be significant even for the most central events. For comparison with the Au-Au results, it is found that the detailed way in which the collision geometry (eccentricity) is estimated is of critical importance when scaling out system-size effects. A new form of eccentricity, called the participant eccentricity, is introduced which yields a scaled elliptic flow in the Cu-Cu system that has the same relative magnitude and qualitative features as that in the Au-Au system.
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We report on measurements of directed flow as a function of pseudorapidity in Au + Au collisions at energies of square root of SNN = 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the BNL Relativistic Heavy Ion Collider. These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.
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We present transverse momentum distributions of charged hadrons produced in Cu + Cu collisions at square root of SNN = 62.4 and 200 GeV. The spectra are measured for transverse momenta of 0.25 < pT < 5.0 GeV/c at square root of SNN = 62.4 GeV and 0.25 < pT < 7.0 GeV/c at square root of SNN = 200 GeV, in a pseudorapidity range of 0.2 < eta < 1.4. The nuclear modification factor R(AA) is calculated relative to p + p data at both collision energies as a function of collision centrality. At a given collision energy and fractional cross section, R(AA) is observed to be systematically larger in Cu + Cu collisions compared to Au + Au. However, for the same number of participating nucleons, R(AA) is essentially the same in both systems over the measured range of pT, in spite of the significantly different geometries of the Cu + Cu and Au + Au systems.
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We have measured transverse momentum distributions of charged hadrons produced in Au+Au collisions at sqrt[s(NN)]=62.4 GeV. The spectra are presented for transverse momenta 0.25
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This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of square root of s(NN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of eta(')=|eta|-y(beam), scale with approximate linearity throughout eta('), implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.
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The objective was to identify and compare causes of unscheduled admission following ambulatory major operative gynecologic laparoscopy in a university hospital and a community hospital setting. Each patient admitted on an unscheduled basis was compared with 2 patients who did not require admission. Twenty-seven variables were evaluated by univariate analysis. Significant factors (p < 0.5) were analyzed by multivariate stepwise logistic regression. Patients admitted at the university hospital were compared with patients at a community hospital. In a 7-year period, 43 patients at the University of Mississippi Medical Center and, in a 6-year period, 30 patients at Gilmore Memorial Hospital required unscheduled admission following ambulatory major operative gynecologic laparoscopy. Site-specific analysis was performed, and these groups also were combined for analysis. The only factor associated with admission by multivariate analysis was estimated operative blood loss. Postoperative emesis was the most common reason for unscheduled admission at both hospitals and occurred in 27 patients. An additional 17 patients were admitted because of the severity of postoperative pain. Operative blood loss seems to be associated with extensive operations. Furthermore, increased blood loss typically leads to a very conservative approach to the postoperative patient, whereas minimal blood loss allows patients to be managed in a routine fashion. Patients at the university hospital seem to be generally comparable to patients at a community hospital. Postoperative nausea and pain resulted in over one half of admissions. Successful therapy for nausea and pain may reduce unscheduled admissions.
Asunto(s)
Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Hospitales Comunitarios , Hospitales Universitarios , Laparoscopía/estadística & datos numéricos , Admisión del Paciente/estadística & datos numéricos , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Femenino , Humanos , Modelos Logísticos , Análisis Multivariante , Dolor Postoperatorio/epidemiología , Complicaciones Posoperatorias/epidemiología , Factores de Riesgo , Vómitos/epidemiologíaRESUMEN
We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at root square[s(NN)] = 200 GeV. For the 6% most central collisions, we obtain dN(ch)/d(eta)/(/eta/<1) = 650+/-35(syst). Compared to collisions at root square[s(NN)] = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.
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We have measured transverse momentum distributions of charged hadrons produced in d+Au collisions at sqrt[s(NN)]=200 GeV. The spectra were obtained for transverse momenta 0.25
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We present measurements of the pseudorapidity distribution of primary charged particles produced in Au+Au collisions at three energies, sqrt[s(NN)]=19.6, 130, and 200 GeV, for a range of collision centrali-ties. The distribution narrows for more central collisions and excess particles are produced at high pseudorapidity in peripheral collisions. For a given centrality, however, the distributions are found to scale with energy according to the "limiting fragmentation" hypothesis. The universal fragmentation region described by this scaling grows in pseudorapidity with increasing collision energy, extending well away from the beam rapidity and covering more than half of the pseudorapidity range over which particles are produced. This approach to a universal limiting curve appears to be a dominant feature of the pseudorapidity distribution and therefore of the total particle production in these collisions.
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The measured pseudorapidity distribution of primary charged particles in minimum-bias d+Au collisions at sqrt[s(NN)]=200 GeV is presented for the first time. This distribution falls off less rapidly in the gold direction as compared to the deuteron direction. The average value of the charged particle pseudorapidity density at midrapidity is
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This paper describes the measurement of collective flow for charged particles in Au+Au collisions at sqrt[s(NN)]=130 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). The measured azimuthal hit anisotropy is presented over a wide range of pseudorapidity (-5.0