1,774 research outputs found

    An Experimental Overview of Results Presented at SQM 2006

    Get PDF
    I have been asked to give an critical overview on the experimental results shown in the conference with a emphasis of what has been learned and the challenges that are ahead in trying to understand the physics of the strongly interacting quark-gluon plasma. I will not try to summarize all of the results presented, rather I will concentrate primarily on RHIC data from this conference. Throughout this summary, I will periodically review some of the previous results for those not familiar with the present state of the field.Comment: 15 pages, 12 Figure

    Directed and Elliptic Flow at RHIC

    Full text link
    We present the directed flow measurement (v1v_1) from Au+Au collisions at \sqrtsNN = 62 GeV. Over the pseudorapidity range we have studied, which covers η\eta from -1.2 to 1.2 and 2.4<η<42.4 < |\eta| < 4, the magnitude of v1v_1 for charged particles is found to increase monotonously with pseudorapidity for all centralities. No ``v1v_1 wiggle'', as predicted by various theoretical models, is observed at midrapidity. Elliptic flow (v2v_2) from moderate high ptp_t particles (36GeV/c3-6 GeV/c) at \sqrtsNN = 200 GeV is presented as a function of impact parameter. It is found that models that are based on {\it jet quenching} alone appear to underpredict v2v_2 at moderate high ptp_t, while the model that incorporates both, recombination and fragmentation, describes the data better.Comment: 6 pages, 4 figures. Proceeding for Hot Quark 04 conference Changes in the revision are mostly English fixes. v1 versus eta plot is flipped over to follow the conventio

    Anisotropic flow at RHIC: How unique is the number-of-constituent-quark scaling?

    Get PDF
    The transverse momentum dependence of the anisotropic flow v2v_2 for π\pi, KK, nucleon, Λ\Lambda, Ξ\Xi and Ω\Omega is studied for Au+Au collisions at sNN=200\sqrt{s_{\rm NN}} = 200 GeV within two independent string-hadron transport approaches (RQMD and UrQMD). Although both models reach only 60% of the absolute magnitude of the measured v2v_2, they both predict the particle type dependence of v2v_2, as observed by the RHIC experiments: v2v_2 exhibits a hadron-mass hierarchy (HMH) in the low pTp_T region and a number-of-constituent-quark (NCQ) dependence in the intermediate pTp_T region. The failure of the hadronic models to reproduce the absolute magnitude of the observed v2v_2 indicates that transport calculations of heavy ion collisions at RHIC must incorporate interactions among quarks and gluons in the early, hot and dense phase. The presence of an NCQ scaling in the string-hadron model results suggests that the particle-type dependencies observed in heavy-ion collisions at intermediate pTp_T might be related to the hadronic cross sections in vacuum rather than to the hadronization process itself.Comment: 10 pages, 5 figures; A new author (H. Petersen) is added; A new figure (fig.1) on time evolution of elliptic flow and number of collisions is added; Version accepted for publication in J. Phys.

    Structural and functional characterizations of mung bean mitochondrial nucleoids

    Get PDF
    Mitochondrial nucleoids isolated from mung bean seedlings exhibited a chromatin-like structure associated with a membrane component. A similar structure, which underwent discrete changes during cotyledon development, was identified in situ. Isolated nucleoids consisted of essentially the same phospholipids, including cardiolipin, as whole mitochondria and proteins of inner- and outer-mitochondrial-membrane origin. Actin was consistently found with mitochondrial nucleoids prepared with different detergent concentrations. Formaldehyde cross-linking of cytochalasin B- and proteinase K-treated mitochondria further revealed that actin was associated with DNA in nucleoids. Mitochondrial nucleoids were self-sufficient in directing DNA synthesis in vitro in a pattern mimicking mtDNA synthesis in isolated mitochondria. In pulse-field gel electrophoresis, newly synthesized mtDNA separated into two major components, well-bound and fast-moving forms. Nucleoids DNA synthesis was resistant to aphidicolin but sensitive to N-ethylmaleimide, which indicates that a γ-type DNA polymerase was responsible for this activity. Mitochondrial nucleoids were capable of self-directed RNA transcription in a non-random fashion in vitro. Consistent with and complementary to results from fungi and human cells done mostly in situ, our present work helps to establish the important paradigm that mitochondrial nucleoids in eukaryotes are more than mere mtDNA compaction and segregation entities but are centers of mtDNA maintenance and expression

    Breadwinners and Homemakers: Migration and Changing Conjugal Expectations in Rural Bangladesh

    Get PDF
    The literature on marriage norms and aspirations across societies largely sees the institution as static – a tool for the assertion of masculinities and subordination of women. The changing meanings of marriage and conjugality in the contemporary context of globalisation have received scant attention. Based on research in rural Bangladesh, this article questions the usefulness of notions of autonomy and dependence in understanding conjugal relations and expectations in a context of widespread migration for extended periods, especially to overseas destinations, where mutuality is crucial for social reproduction, though in clearly genderdemarcated domains

    Adaptive servoventilation improves cardiac function and respiratory stability

    Get PDF
    Cheyne–Stokes respiration (CSR) in patients with chronic heart failure (CHF) is of major prognostic impact and expresses respiratory instability. Other parameters are daytime pCO2, VE/VCO2-slope during exercise, exertional oscillatory ventilation (EOV), and increased sensitivity of central CO2 receptors. Adaptive servoventilation (ASV) was introduced to specifically treat CSR in CHF. Aim of this study was to investigate ASV effects on CSR, cardiac function, and respiratory stability. A total of 105 patients with CHF (NYHA ≥ II, left ventricular ejection fraction (EF) ≤ 40%) and CSR (apnoea–hypopnoea index ≥ 15/h) met inclusion criteria. According to adherence to ASV treatment (follow-up of 6.7 ± 3.2 months) this group was divided into controls (rejection of ASV treatment or usage <50% of nights possible and/or <4 h/night; n = 59) and ASV (n = 56) adhered patients. In the ASV group, ventilator therapy was able to effectively treat CSR. In contrast to controls, NYHA class, EF, oxygen uptake, 6-min walking distance, and NT-proBNP improved significantly. Moreover, exclusively in these patients pCO2, VE/VCO2-slope during exercise, EOV, and central CO2 receptor sensitivity improved. In CHF patients with CSR, ASV might be able to improve parameters of SDB, cardiac function, and respiratory stability

    A Hedged Monte Carlo Approach to Real Option Pricing

    Full text link
    In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

    Baryon Stopping and Charged Particle Distributions in Central Pb+Pb Collisions at 158 GeV per Nucleon

    Get PDF
    Net proton and negative hadron spectra for central \PbPb collisions at 158 GeV per nucleon at the CERN SPS were measured and compared to spectra from lighter systems. Net baryon distributions were derived from those of net protons, utilizing model calculations of isospin contributions as well as data and model calculations of strange baryon distributions. Stopping (rapidity shift with respect to the beam) and mean transverse momentum \meanpt of net baryons increase with system size. The rapidity density of negative hadrons scales with the number of participant nucleons for nuclear collisions, whereas their \meanpt is independent of system size. The \meanpt dependence upon particle mass and system size is consistent with larger transverse flow velocity at midrapidity for \PbPb compared to \SS central collisions.Comment: This version accepted for publication in PRL. 4 pages, 3 figures. Typos corrected, some paragraphs expanded in response to referee comments, to better explain details of analysi

    Precision Physics at LEP

    Get PDF
    1 - Introduction 2 - Small-Angle Bhabha Scattering and the Luminosity Measurement 3 - Z^0 Physics 4 - Fits to Precision Data 5 - Physics at LEP2 6 - ConclusionsComment: Review paper to appear in the RIVISTA DEL NUOVO CIMENTO; 160 pages, LateX, 70 eps figures include
    corecore