85 research outputs found
Graviton emission from a higher-dimensional black hole
We discuss the graviton absorption probability (greybody factor) and the
cross-section of a higher-dimensional Schwarzschild black hole (BH). We are
motivated by the suggestion that a great many BHs may be produced at the LHC
and bearing this fact in mind, for simplicity, we shall investigate the
intermediate energy regime for a static Schwarzschild BH. That is, for
, where is the mass of the black hole and
is the energy of the emitted gravitons in -dimensions. To find
easily tractable solutions we work in the limit , where is the
angular momentum quantum number of the graviton.Comment: 10 pages, 8 figures, references added, typos corrected. Graviton
degeneracy factor included; main results remain unchange
The design of a project to assess bilateral versus unilateral hearing aid fitting
Binaural hearing provides advantages over monaural in several ways, particularly in difficult listening situations. For a person with bilateral hearing loss, the bilateral fitting of hearing aids thus seems like a natural choice. However, surprisingly few studies have been reported in which the additional benefit of bilateral versus unilateral hearing aid use has been investigated based on real-life experiences. Therefore, a project has been designed to address this issue and to find tools to identify people for whom the drawbacks would outweigh the advantages of bilateral fitting. A project following this design is likely to provide reliable evidence concerning differences in benefit between unilateral and bilateral fitting of hearing aids by evaluating correlations between entrance data and outcome measures and final preferences
Transfer of passive immunity and serum proteinogram in the first six months of life of Criollo Lageano and black and white holstein calves
High-dimensional maximum marginal likelihood item factor analysis by adaptive quadrature
Although the Bock–Aitkin likelihood-based estimation method for factor analysis of dichotomous item response data has important advantages over classical analysis of item tetrachoric correlations, a serious limitation of the method is its reliance on fixed-point Gauss-Hermite (G-H) quadrature in the solution of the likelihood equations and likelihood-ratio tests. When the number of latent dimensions is large, computational considerations require that the number of quadrature points per dimension be few. But with large numbers of items, the dispersion of the likelihood, given the response pattern, becomes so small that the likelihood cannot be accurately evaluated with the sparse fixed points in the latent space. In this paper, we demonstrate that substantial improvement in accuracy can be obtained by adapting the quadrature points to the location and dispersion of the likelihood surfaces corresponding to each distinct pattern in the data. In particular, we show that adaptive G-H quadrature, combined with mean and covariance adjustments at each iteration of an EM algorithm, produces an accurate fast-converging solution with as few as two points per dimension. Evaluations of this method with simulated data are shown to yield accurate recovery of the generating factor loadings for models of upto eight dimensions. Unlike an earlier application of adaptive Gibbs sampling to this problem by Meng and Schilling, the simulations also confirm the validity of the present method in calculating likelihood-ratio chi-square statistics for determining the number of factors required in the model. Finally, we apply the method to a sample of real data from a test of teacher qualifications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43596/1/11336_2003_Article_1141.pd
Transferência de imunidade passiva em bezerros das raças Nelore e Limousin e proteinograma sérico nos primeiros quatro meses de vida
Rock coast geomorphology: Recent advances and future research directions
There have been considerable advances in rock coast research in the past decade, as measured in terms of the number of active researchers and in the number of research papers being produced. This review, although not exhaustive, highlights many of the improvements that have been made in our ability to identify and measure the processes shaping rock coasts, at a range of spatial and temporal scales. We review how researchers are experimenting with new techniques; grappling with quantifying the effects of multiple processes on resultant landforms; and exploring how well rock coast systems relate to wider geomorphological and earth science debates. Recent research, including those in this special issue, aptly demonstrate the scientific benefits that can be accrued by studying rock coasts at a variety of spatial and temporal scales, by considering the effect of the wide range of processes that operate on them, and by the application of new measurement techniques and approaches. Despite these advances, there is ample scope for future research, which could profit from increasing collaboration with other coastal geomorphologists and allied earth science disciplines in order to identify and quantify linkages between rock coasts and other coastal systems. It is also important that new research considers how rock coasts will respond to extreme events and to risks associated with changing climate, and to how rock coast geomorphology might contribute, beyond coastal science, to wider debates in theoretical geomorphology
Evaluation of a possible role for the dopamine D1 and D2 receptors in the steroid-dependent suppression of luteinizing hormone secretion in the seasonally anoestrous ewe
Changing Patterns of Carotid Endarterectomy Between 2011 and 2017 in England: A Population-Based Cohort Study
The characteristics of antibiotic resistance and phenotypes in 29 outer‐membrane protein mutant strains in Aeromonas hydrophila
Do depression, stress, inflammation and sleep alter hippocampal apoptosis and neurogenesis?
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