677 research outputs found

    Azimuth Quadrupole Systematics in Au-Au Collisions

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    We have measured ptp_t-dependent two-particle number correlations on azimuth and pseudorapidity for eleven centralities of sNN=62\sqrt{s_{NN}} = 62 and 200~GeV Au-Au collisions at STAR. 2D fits to these angular correlations isolate the azimuth quadrupole amplitude, denoted 2v22{2D}(pt)2 v_2^2 \{ 2D \} ( p_t ), from localized same-side correlations. Event-plane v2(pt)v_2 ( p_t ) measurements within the STAR TPC acceptance can be expressed as a sum of the azimuth quadrupole and the quadrupole component of the same-side peak. v2{2D}(pt)v_2 \{ 2D \} ( p_t ) can be transformed to reveal quadrupole ptp_t spectra which are approximately described by a fixed transverse boost and universal L\'evy form nearly independent of centrality. A parametrization of v2{2D}(pt)v_2 \{ 2D \} ( p_t ) can be factored into centrality and ptp_t-dependent pieces with a simple ptp_t dependence above 0.75 GeV/c. Results from STAR are compared to published data and model predictions.Comment: Conference proceedings for Hot Quarks 201

    PREDICTORS IN FINISHING POSITION OF NCAA DIVISION II SCHOOLS IN THE LEARFIELD SPORTS-NACDA DIRECTORS’ CUP: CULTURE TYPE AS A POTENTIAL MEDIATOR

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    Predictor variables, institution type and annual allocated revenue, were investigated as potential predictors of success in NCAA Division II Athletic Departments, on the outcome variable (points scored in the Learfield sports-NACDA Directors’ Cup), working through mediating variables representing culture type (clan, adhocracy, market, and hierarchy). Data were collected through an electronic survey emailed to all NCAA Division II institution athletic directors and head coaches. Data specific to institution type (public vs private) and the number of points an athletic department earned in the Learfield sports-NACDA Directors’ Cup was also collected from archived records. Statistical testing included the use of SPSS and the PROCESS Macro to make inferences about direct effects of predictor variables on the outcome variable, inferences about specific indirect effects of predictor variables on the outcome variable through mediating variables, pairwise comparisons between specific indirect effects, and inference about the total indirect effect. Of all the respondents (N=847) to the survey, 285 different NCAA Division II athletic departments were represented. Because of the definition and nature of culture, the number of usable athletic departments was reduced to 67 with a total of 337 respondents with usable data for analysis. Bivariate correlation analysis between the number of Directors’ Cup points scored three culture types was found to be statistically significant. However, only the correlation between market culture the number of Directors’ Cup points scored was found to moderate in size r(335) = .250. Mediation analysis found only one statistically significant interaction between a dependent variable and mediating variable leading to the outcome. Annual allocated revenue was found to effect the number of Directors’ Cup points earned when operating through market culture. In addition, the mediating effect of market culture was found to be statistically different from adhocracy culture and hierarchy culture

    The Impact of Language Translation on the Internal Structure of a Rating Scale: The Strengths and Difficulties Questionnaire in Spanish

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    The purpose of this study was to compare the psychometric properties of the Spanish version of the Strengths and Difficulties Questionnaire SDQ a 25-item behavioral screener with the English version Participants included in this study were 363 English-speaking parents and 334 Spanish-speaking parents of preschool age children ages 3-5 who took part in the Children s Hospital of Orange County University of California Irvine Initiative for the Development of Attention and Readiness CUIDAR program from 2004-2008 This study used data from the CUIDAR program to explore mean rating differences between the English and Spanish versions of the SDQ along with coefficient alpha as an indicator of reliability at the scale and composite level and factor analytic evidence of score validity Mean ratings of the scales and the Total Difficulties scale were very similar across language forms Reliability coefficients indicated alphas were higher for scores derived from the English forms compared to the Spanish forms at the scale and composite levels although neither form produced scores with adequate reliability at the scale level Finally the Five First Order Factor Model was the best-fitting and most valid representation of all 25 items of the SDQ regardless of the language of the for

    The azimuth structure of nuclear collisions -- I

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    We describe azimuth structure commonly associated with elliptic and directed flow in the context of 2D angular autocorrelations for the purpose of precise separation of so-called nonflow (mainly minijets) from flow. We extend the Fourier-transform description of azimuth structure to include power spectra and autocorrelations related by the Wiener-Khintchine theorem. We analyze several examples of conventional flow analysis in that context and question the relevance of reaction plane estimation to flow analysis. We introduce the 2D angular autocorrelation with examples from data analysis and describe a simulation exercise which demonstrates precise separation of flow and nonflow using the 2D autocorrelation method. We show that an alternative correlation measure based on Pearson's normalized covariance provides a more intuitive measure of azimuth structure.Comment: 27 pages, 12 figure

    Life and Liesegang: Outcrop-Scale Microbially Induced Diagenetic Structures and Geochemical Self-Organization Phenomena Produced by Oxidation of Reduced Iron

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    The Kanab Wonderstone is sandstone (Shinarump Member, Chinle Formation) that is cemented and stained with iron oxide. The iron-oxide cementation and staining in these rocks have been considered examples of the Liesegang phenomenon, but we will show that they comprise a microbially induced structure. The spacing of bands of iron-oxide stain follow the Jablczynski spacing law (wherein the spacing between bands of iron-oxide stain increases as one traverses a series of bands) characteristic of Liesegang. Bands of iron-oxide cement exhibit more variable spacing and exhibit a weak but significant correlation between band thickness and distance between bands of cement. The pore-filling cement contains morphotypes that are similar in size and habit to those exhibited by microaerophilic iron-oxidizing bacteria. Other disseminated iron-oxide mineralization occurs as rhombohedra interpreted to be pseudomorphs after siderite. We interpret the cement to be produced by microbially mediated oxidation of siderite (a typical early diagenetic mineral in fluvial sandstones). Iron-oxidizing bacteria colonized the redox interface between siderite-cemented sand and porous sandstone. Microbes oxidized aqueous Fe(II), generating acid that caused siderite dissolution. The iron-oxide cement is the microbial product of a geochemical drive for organization; whereas the iron-oxide stain is true Liesegang. Together, they comprise a distinctive microbially induced structure with high preservation potential. Key Words: Biosignatures—Iron oxides—Diagenesis—Iron-oxidizing bacteria—Shinarump

    Third Harmonic Flow of Charged Particles in Au+Au Collisions at sNN=200\sqrt {s_{NN}} = 200 GeV

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    In this proceedings, we report measurements of the third harmonic coefficient of the azimuthal anisotropy, v3v_{3}, known as triangular flow. The analysis is for charged particles near midrapidity in Au+Au collisions at sNN\sqrt {s_{NN}} = 200 GeV, based on data from the STAR experiment at the Relativistic Heavy Ion Collider. Triangular flow as a function of centrality, pseudorapidity and transverse momentum are reported using various methods, including a study of the signal for particle pairs as a function of their pseudorapidity separation. Results are compared with other experiments and model predictions.Comment: Talk given by Yadav Pandit (For the STAR Collaboration) at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS): 10 pages, 8 figure

    3D macro- and microfabric analyses of Neoproterozoic diamictites from the Valjean Hills, California (United States)

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    The Cryogenian interval (720–635 Ma) is famous for a rich archive of diamictites, many of which were deposited during glaciations. Classic examples are exposed in the Kingston Peak Formation of the Valjean Hills, near Death Valley (United States), with previous work pointing to multiple glacial cycles in other outcrop belts. Within any glacial period, diamictites are widespread, and in addition, their mechanics of deposition are highly variable. Some are massive in appearance at outcrop or in hand specimens and apparently lack any information that allows their mode of emplacement to be elucidated. Yet, the correct interpretation for deep-time successions in this area is especially important, since it is debated whether the diamictites are either associated with a tectonically driven origin, associated with rifting at the south-western Laurentian margin alongside slope-controlled gravitational mass movement, or predominantly deposited as (sub)glacial diamictites. In this paper, we demonstrate how diamictite texture can be objectively quantified based on clast orientations, at both macroscale and microscale (micromorphology), guiding interpretations. Our method is based on a technique used for Quaternary sediments, by mapping the apparent longest axes of skeleton grains (ranging from fine-grained sand to fine-grained pebbles) in oriented thin sections and reconstructing their microfabric in a 3D space coupled with macrofabric data for each diamictite. In this way, we could identify a bimodal signal in the orientation of the longest axes for each sample. Evidence for shearing and soft sediment deformation supports either subaqueous or subglacial deposition with deformation induced by basal sliding with a paleoflow directed toward the southeast. Our combined approach of micro- and macrofabric analyses can also encourage acquiring accurate fabric data for seemingly structureless diamictites from other deep-time rock archives in an objective manner

    New Perspectives on Glacial Geomorphology in Earth's Deep Time Record

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    International audienceThe deep time (pre-Quaternary) glacial record is an important means to understand the growth, development, and recession of the global cryosphere on very long timescales (10 6-10 8 Myr). Sedimentological description and interpretation of outcrops has traditionally played an important role. Whilst such data remain vital, new insights are now possible thanks to freely accessible aerial and satellite imagery, the widespread availability and affordability of Uncrewed Aerial Vehicles, and accessibility to 3D rendering software. In this paper, we showcase examples of glaciated landscapes from the Cryogenian, Ediacaran, Late Ordovician and Late Carboniferous where this approach is revolutionizing our understanding of deep time glaciation. Although some problems cannot be overcome (erosion or dissolution of the evidence), robust interpretations in terms of the evolving subglacial environment can be made. Citing examples from Australia (Cryogenian), China (Ediacaran), North and South Africa (Late Ordovician, Late Carboniferous), and Namibia (Late Carboniferous), we illustrate how the power of glacial geomorphology can be harnessed to interpret Earth's ancient glacial record
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