Performance of the PHOBOS silicon sensors Decowski, M.P; Back, B.B; Baker, M.D ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2002, Letnik:
478, Številka:
1
Journal Article
Recenzirano
The PHOBOS detector is designed to study the physics of Au+Au collisions at the Relativistic Heavy Ion Collider. The detector is almost entirely made of silicon pad detectors and was fully ...operational during the first year of operation. The detector is described, and key performance characteristics are summarized.
Inhalation of the pulmonary irritant ozone is associated with an accumulation of macrophages in the lung. These cells, along with type II epithelial cells, are activated to release increased ...quantities of hydrogen peroxide and nitric oxide, two reactive mediators that have been implicated in tissue injury. In the present studies we determined whether pretreatment of rats with bacterially derived endotoxin, which modulates oxidant levels in tissues, could abrogate the effects of ozone on lung injury and nitric oxide production. Acute exposure of rats to ozone (2 parts per million, 3 h) resulted in nitric oxide production in the lung as measured by electron paramagnetic resonance spin trapping. This was correlated with expression of inducible nitric oxide synthase (iNOS) mRNA in the lung as determined by in situ hybridization. Particularly high levels of iNOS were evident in alveolar macrophages and type II cells. Alveolar macrophages isolated from ozone-treated rats also expressed increased iNOS mRNA and protein as measured by Northern and Western blotting, respectively, and produced more nitric oxide compared with cells from air-exposed animals. Treatment of rats with endotoxin (5 mg/kg, intravenously), 30 min prior to ozone, was found to abrogate ozone-induced increases in iNOS mRNA and protein expression, as well as nitric oxide production by alveolar macrophages. This was associated with a reduction in ozone-induced tissue injury as determined by levels of lung lavage fluid protein. Ozone inhalation also resulted in a reduction in intracellular glutathione in alveolar macrophages, an effect that was blocked by endotoxin administration. Taken together, these data provide evidence that the protective effects of endotoxin against ozone-induced injury are mediated, at least in part, by alterations in levels of lung oxidants and antioxidants.
Measuring mid-rapidity multiplicity in PHOBOS Iordanova, Aneta; Collaboration, the PHOBOS; Back, B B ...
Journal of physics. Conference series,
01/2005, Letnik:
5, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Several techniques have been developed by PHOBOS for measuring the multiplicity of charged particles produced in Au + Au collisions. We will discuss one of these techniques (the Tracklet method) ...which utilizes two-hit tracks which intersect at the reconstructed collision vertex position. The physics that comes from these measurements can give valuable insight into the underlying mechanisms of particle production over a center of mass energy range of SNN 19.6 GeV to the maximum RHIC energy of SNN 200 GeV.
Recent results from PHOBOS at RHIC Back, B.B.; Baker, M.D.; Ballintijn, M. ...
Brazilian journal of physics,
09/2004, Letnik:
34, Številka:
3a
Journal Article
Recenzirano
Odprti dostop
PHOBOS is one of the four heavy ion experiments currently running at the Relativistic Heavy Ion Collider (RHIC). In this paper we will present some of the current results from PHOBOS: the study of ...charged multiplicity distribution as function of pseudorapidity and centrality at or = 19.6, 130 and 200 GeV, a discussion of multiplicity scaling, and a measurement of transverse momentum spectra (pT) of charged hadrons produced in d+Au and Au+Au interactions at or = 200 GeV. The dependence of the Au+Au yields as function of centrality is found to be independent of pT. A strong suppression in the Au+Au hadron spectra relative to p at high pT is observed. The spectral shape for d+Au collisions is significantly different from the observations in Au+Au, the yield suppression is not observed in d+Au.
Political developments in Kansas in the 1890s in terms of the party system and realignment perspective are studied using multiple regression techniques to county voting returns. This uncovers changes ...in voting patterns with estimates of the transitional probabilities of partisan choice from election to election.
The roles of blacks and racial issues in Populism in the 1890s, with a focus on the state of Texas, are explored. Texas Populists' principal approach to securing the black vote was through the device ...of "fusion" or combining with the Republican party.
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