1,400 research outputs found

    Hawking Radiation of Black p-Branes from Gravitational Anomaly

    Full text link
    We investigate the Hawking radiation of black pp-branes of superstring theories using the method of anomaly cancelation, specially, we use the method of [S. Iso, H. Umetsu and F. Wilczek, {\sl Phys. Rev. Lett.} {\bf 96}, 151302 (2006); {\sl Phys. Rev. D} {\bf 74}, 044017 (2006)]. The metrics of black pp-branes are spherically symmetric, but not the Schwarzschild type. In order to simplify the calculation, we first make a coordinate transformation to transform the metric to the Schwarzschild type. Then we calculate its energy-momentum flux from the method of anomaly cancelation of the above mentioned references. The obtained energy-momentum flux is equal to a black body radiation, the thermodynamic temperature of the radiation is equal to its Hawking temperature. And we find that the results are not changed for the original non-Schwarzschild type spherically symmetric metric.Comment: 19 pages Latex, some mistakes correcte

    Can Performance of Indigenous Factors Influence Growth and Globalization?

    Get PDF
    This paper employs a total of thirty four openness factors and indigenous factors to construct two indicators for 62 world economies for the period 1998-2002. While most globalization studies concentrated on openness factors, regression estimates and simulation studies show that sound performance in indigenous factors are crucial to an economy’s growth and globalization. Empirical evidence shows that an optimal performance in indigenous factors can be identified, and that successful globalized economies are equipped with strong performance in their indigenous factors.Globalization, indigenous factors, openness, world economies

    Gravitational anomalies: a recipe for Hawking radiation

    Get PDF
    We explore the method of Robinson and Wilczek for deriving the Hawking temperature of a black hole. In this method, the Hawking radiation restores general covariance in an effective theory of near-horizon physics which otherwise exhibits a gravitational anomaly at the quantum level. The method has been shown to work for broad classes of black holes in arbitrary spacetime dimensions. These include static black holes, accreting or evaporating black holes, charged black holes, rotating black holes, and even black rings. In the case of charged and rotating black holes, the expected super-radiant current is also reproduced.Comment: 7 pages; This essay received an "Honorable Mention" in the 2007 Essay Competition of the Gravity Research Foundation; (v2) Short comments and references added; (v3) Minor revisions and updated references to agree with published versio

    Ecogeomorphic feedbacks and flood loss of riparian tree seedlings in meandering channel experiments

    Get PDF
    During floods, fluvial forces interact with riparian plants to influence evolution of river morphology and floodplain plant community development. Understanding of these interactions, however, is constrained by insufficient precision and control of drivers in field settings, and insufficient realism in laboratory studies. We completed a novel set of flume experiments using woody seedlings planted on a sandbar within an outdoor meandering stream channel. We quantified effects on local sedimentation and seedling loss to scour and burial across realistic ranges of woody plant morphologies (Populus versus Tamarix species), densities (240 plants m-2 versus 24 m-2), and sediment supply (equilibrium versus deficit). Sedimentation was higher within Tamarix patches than Populus patches, reflecting Tamarix’s greater crown frontal area and lower maximum crown density. Plant dislodgement occurred rarely (1% of plants) and was induced in plants with shorter roots. Complete burial was most frequent for small Tamarix that occurred at high densities. Burial risk decreased 3% for Populus and 13% for Tamarix for every centimeter increment in stem height, and was very low for plants \u3e50 cm tall. These results suggest that Tamarix are proportionally more vulnerable than Populus when small (\u3c20 cm tall), but that larger plants of both species are resistant to both burial and scour. Thus, plant morphological traits and development windows must be considered in addition to physical drivers when designing process-based restoration efforts on regulated rivers such as flow releases to benefit native tree species

    TSG-6 Downregulates IFN-Alpha and TNF-Alpha Expression by Suppressing IRF7 Phosphorylation in Human Plasmacytoid Dendritic Cells

    Get PDF
    Proinflammatory cytokines such as TNF-α and type I interferons (IFN) are pathogenic signatures of systemic lupus erythematosus, and plasmacytoid dendritic cells (pDCs) play a major role by predominantly producing IFN-α. Given the rise of importance in identifying tumor necrosis stimulated gene 6 (TSG-6) as a key anti-inflammatory regulator, we investigate its function and its ability to counteract proinflammatory cytokine secretion by pDCs in vitro. CpG-A and R837 induced significant endogenous TSG-6 expression in the pDC cell-line GEN2.2. Following recombinant human TSG-6 treatment and CpG-A or R837 stimulation, significant reduction in IFN-α and TNF-α was observed in healthy donors’ pDCs, and the same phenomenon was confirmed in GEN2.2. By CD44 blocking assay, we deduced that the suppressive effect of TSG-6 is mediated by CD44, by reducing IRF-7 phosphorylation. Our findings suggest that TSG-6 and its downstream signalling pathway could potentially be targeted to modulate proinflammatory cytokine expression in pDCs

    Activities and Role of School-Based Counselors in the US: A National Survey of American Counseling Association Members

    Get PDF
    This study was conducted to determine: how a US sample of American Counseling Association (ACA) affiliated school-based counselors viewed their role; the extent to which various activities were practiced; and, how demographic variables (e.g., work setting and professional identity) were related to both perceptions of role and practice. Participants (N = 249) completed the International Survey of School Counselors Activities-US (ISSA-US) online, which measured both perceptions of the appropriateness of 42 activities and whether these activities are reported to be enacted. US counselors had a broad definition of their role and showed a high degree of consensus regarding the appropriateness of activities. Grade level proved to be an important determinate of the level of enactment of both group counseling and college and career counseling. The implications for of these findings for redefining the role of school counselors in the US and for international comparative research are discussed

    Can performance of indigenous factors influence growth and globalisation?

    Get PDF
    This paper employs a total of thirty four openness factors and indigenous factors to construct two indicators for 62 world economies for the period 1998-2002. While most globalisation studies concentrated on openness factors, regression estimates and simulation studies show that sound performance in indigenous factors are crucial to an economy's growth and globalisation. Empirical evidence shows that an optimal performance in indigenous factors can be identified, and that successful globalised economies are equipped with strong performance in their indigenous factors
    • …
    corecore