1,210 research outputs found
Higgsino Dark Matter in Nonuniversal Gaugino Mass Models
We study two simple and well motivated nonuniversal gaugino mass models,
which predict higgsino dark matter. One can account for the observed dark
matter relic density along with the observed Higgs boson mass of ~ 125 GeV over
a large region of the parameter space of each model, corresponding to higgsino
mass of ~ 1 TeV. In each case this parameter region covers the gluino mass
range of 2-3 TeV, parts of which can be probed by the 14 TeV LHC experiments.
We study these model predictions for LHC in brief and for dark matter detection
experiments in greater detail.Comment: 35 pages, 11 figures, pdflatex, new references and a few relevant
decay branching ratios added in two tables. Version to appear in Phys Rev
Enteroaggregative Escherichia coli: An Emerging Enteric Food Borne Pathogen
Enteroaggregative Escherichia coli (EAEC) are quite heterogeneous category of an emerging enteric pathogen associated with cases of acute or persistent diarrhea worldwide in children and adults, and over the past decade has received increasing attention as a cause of watery diarrhea, which is often persistent. EAEC infection is an important cause of diarrhea in outbreak and non-outbreak settings in developing and developed countries. Recently, EAEC has been implicated in the development of irritable bowel syndrome, but this remains to be confirmed. EAEC is defined as a diarrheal pathogen based on its characteristic aggregative adherence (AA) to HEp-2 cells in culture and its biofilm formation on the intestinal mucosa with a “stacked-brick” adherence phenotype, which is related to the presence of a 60 MDa plasmid (pAA). At the molecular level, strains demonstrating the aggregative phenotype are quite heterogeneous; several virulence factors are detected by polymerase chain reaction; however, none exhibited 100% specificity. Although several studies have identified specific virulence factor(s) unique to EAEC, the mechanism by which EAEC exerts its pathogenesis is, thus, far unknown. The present review updates the current knowledge on the epidemiology, chronic complications, detection, virulence factors, and treatment of EAEC, an emerging enteric food borne pathogen
Precedence tests and confidence bounds for complete data : an overview and some results
An overview of some nonparametric procedures based on precedence (or exceedance) statistics is given. The procedures include both tests and confidence intervals. In particular, the construction of some simple distribution-free confidence bounds for location difference of two distributions with the same shape is considered and some properties are derived. The asymptotic relative efficiency of an asymptotic form of the corresponding test relative to Wilcoxon's two-sample rank-sum test and the two-sample Student's t-test is given for various cases. Some K -sample problems are discussed where precedence type tests are useful, along with a review of the literature
Dynamic asset trees and Black Monday
The minimum spanning tree, based on the concept of ultrametricity, is
constructed from the correlation matrix of stock returns. The dynamics of this
asset tree can be characterised by its normalised length and the mean
occupation layer, as measured from an appropriately chosen centre called the
`central node'. We show how the tree length shrinks during a stock market
crisis, Black Monday in this case, and how a strong reconfiguration takes
place, resulting in topological shrinking of the tree.Comment: 6 pages, 3 eps figues. Elsevier style. Will appear in Physica A as
part of the Bali conference proceedings, in pres
Precedence probability, prediction interval and a combinatorial identity
Precedence tests are simple yet useful nonparametric tests based on two specified order statistics from independent random samples or, equivalently, on the count of the number of observations from one of the samples preceding some order statistic of the other sample. The probability that an order statistic from the second sample exceeds an order statistic from the first sample is termed the precedence probability. When the distributions are the same, this probability can be calculated exactly, without any specific knowledge of the underlying common continuous distribution. This fact can be utilized to set up nonparametric prediction intervals in a number of situations. In this paper, prediction intervals are considered for the number of second sample observations that exceed a particular order statistic of the first sample. To aid the user, tables are provided for small sample sizes, where exact calculations are most necessary. The same tables can be used to implement a precedence test for small sample sizes. Finally, a combinatorial identity is proved. Keywords: Distribution-free; Extremes; Exceedance and Precedence; Nonparametric; Order statistics
Precedence probability and prediction intervals
Precedence tests are simple yet useful nonparametric tests based on two specified order statistics from two independent random samples or, equivalently, on the count of the number of observations from one of the samples preceding some order statistic of the other sample. The probability that an order statistic from the second sample exceeds an order statistic from the first sample is termed the precedence probability. When the distributions are the same, this probability can be calculated exactly, without any specific knowledge of the underlying common continuous distribution. This fact can be utilized to set up nonparametric prediction intervals in a number of situations. In this paper, prediction intervals are considered for the number of second sample observations that exceed a particular order statistic of the first sample. To aid the user, tables are provided for small sample sizes, where exact calculations are most necessary. The same tables can be used to implement a precedence test for small sample sizes
An Outlook on Correlations in Stock Prices
We present an outlook of the studies on correlations in the price timeseries
of stocks, discussing the construction and applications of "asset tree". The
topic discussed here should illustrate how the complex economic system
(financial market) enrichens the list of existing dynamical systems that
physicists have been studying for long.Comment: 6 pages, RevTeX format. To appear in the Conference Proceedings of
ECONOPHYS-KOLKATA II: International Workshop on Econophysics of Stock Markets
and Minority Games", February 14-17, 2006, SINP, Kolkata, as a book chapter
in Eds. A. Chatterjee and B.K. Chakrabarti, Econophysics of Stock and other
Markets, (Springer-Verlag (Italia), Milan, 2006
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