5,793 research outputs found
Predictions for the unitarity triangle angles in a new parametrization
A new approach to the parametrization of the CKM matrix, , is considered
in which is written as a linear combination of the unit matrix and a
non-diagonal matrix which causes intergenerational-mixing, that is
. Such a depends on 3 real parameters
including the parameter . It is interesting that a value of
is required to fit the available data on the CKM-matrix
including CP-violation. Predictions of this fit for the angles ,
and for the unitarity triangle corresponding to
, are given. For
=, we obtain , and
. These values are just about in agreement, within errors,
with the present data. It is very interesting that the unitarity triangle is
expected to be approximately a right-angled, isosceles triangle. Our prediction
is in excellent agreement with the value reported by the Belle collaboration at the Lepton-Photon 2001 meeting.Comment: 11 pages, latex, no figure
Mycobiome of the Bat White Nose Syndrome (WNS) Affected Caves and Mines reveals High Diversity of Fungi and Local Adaptation by the Fungal Pathogen Pseudogymnoascus (Geomyces) destructans
The investigations of the bat White Nose Syndrome (WNS) have yet to provide
answers as to how the causative fungus Pseudogymnoascus (Geomyces) destructans
(Pd) first appeared in the Northeast and how a single clone has spread rapidly
in the US and Canada. We aimed to catalogue Pd and all other fungi (mycobiome)
by the culture-dependent (CD) and culture-independent (CI) methods in four
Mines and two Caves from the epicenter of WNS zoonotic. Six hundred sixty-five
fungal isolates were obtained by CD method including the live recovery of Pd.
Seven hundred three nucleotide sequences that met the definition of operational
taxonomic units (OTUs) were recovered by CI methods. Most OTUs belonged to
unidentified clones deposited in the databases as environmental nucleic acid
sequences (ENAS). The core mycobiome of WNS affected sites comprised of 46
species of fungi from 31 genera recovered in culture, and 17 fungal genera and
31 ENAS identified from clone libraries. Fungi such as Arthroderma spp.,
Geomyces spp., Kernia spp., Mortierella spp., Penicillium spp., and
Verticillium spp. were predominant in culture while Ganoderma spp., Geomyces
spp., Mortierella spp., Penicillium spp. and Trichosporon spp. were abundant is
clone libraries. Alpha diversity analyses from CI data revealed that fungal
community structure was highly diverse. However, the true species diversity
remains undetermined due to under sampling. The frequent recovery of Pd
indicated that the pathogen has adapted to WNS-afflicted habitats. Further,
this study supports the hypothesis that Pd is an introduced species. These
findings underscore the need for integrated WNS control measures that target
both bats and the fungal pathogen.Comment: 59 pages, 7figure
Algebraic Shape Invariant Models
Motivated by the shape invariance condition in supersymmetric quantum
mechanics, we develop an algebraic framework for shape invariant Hamiltonians
with a general change of parameters. This approach involves nonlinear
generalizations of Lie algebras. Our work extends previous results showing the
equivalence of shape invariant potentials involving translational change of
parameters with standard potential algebra for Natanzon type
potentials.Comment: 8 pages, 2 figure
The Schwinger Representation of a Group: Concept and Applications
The concept of the Schwinger Representation of a finite or compact simple Lie
group is set up as a multiplicity-free direct sum of all the unitary
irreducible representations of the group. This is abstracted from the
properties of the Schwinger oscillator construction for SU(2), and its
relevance in several quantum mechanical contexts is highlighted. The Schwinger
representations for and SU(n) for all are constructed via
specific carrier spaces and group actions. In the SU(2) case connections to the
oscillator construction and to Majorana's theorem on pure states for any spin
are worked out. The role of the Schwinger Representation in setting up the
Wigner-Weyl isomorphism for quantum mechanics on a compact simple Lie group is
brought out.Comment: Latex, 17 page
Fractional statistic
We improve Haldane's formula which gives the number of configurations for
particles on states in a fractional statistic defined by the coupling
. Although nothing is changed in the thermodynamic limit, the new
formula makes sense for finite with integer and A
geometrical interpretation of fractional statistic is given in terms of
''composite particles''.Comment: flatex hald.tex, 3 files Submitted to: Phys. Rev.
Vascular risk factors and diabetic neuropathy
Background: Other than glycemic control, there are no treatments for diabetic neuropathy. Thus, identifying potentially modifiable risk factors for neuropathy is crucial. We studied risk factors for the development of distal symmetric neuropathy in 1172 patients with type 1 diabetes mellitus from 31 centers participating in the European Diabetes (EURODIAB) Prospective Complications Study.
Methods: Neuropathy was assessed at baseline (1989 to 1991) and at follow-up (1997 to 1999), with a mean (±SD) follow-up of 7.3±0.6 years. A standardized protocol included clinical evaluation, quantitative sensory testing, and autonomic-function tests. Serum lipids and lipoproteins, glycosylated hemoglobin, and the urinary albumin excretion rate were measured in a central laboratory.
Results: At follow-up, neuropathy had developed in 276 of 1172 patients without neuropathy at baseline (23.5 percent). The cumulative incidence of neuropathy was related to the glycosylated hemoglobin value and the duration of diabetes. After adjustment for these factors, we found that higher levels of total and low-density lipoprotein cholesterol and triglycerides, a higher body-mass index, higher von Willebrand factor levels and urinary albumin excretion rate, hypertension, and smoking were all significantly associated with the cumulative incidence of neuropathy. After adjustment for other risk factors and diabetic complications, we found that duration of diabetes, current glycosylated hemoglobin value, change in glycosylated hemoglobin value during the follow-up period, body-mass index, and smoking remained independently associated with the incidence of neuropathy. Cardiovascular disease at baseline was associated with double the risk of neuropathy, independent of cardiovascular risk factors.
Conclusions: This prospective study indicates that, apart from glycemic control, the incidence of neuropathy is associated with potentially modifiable cardiovascular risk factors, including a raised triglyceride level, body-mass index, smoking, and hypertension
Vascular endothelium: the battlefield of dengue viruses
Increased vascular permeability without morphological damage to the capillary endothelium is the cardinal feature of dengue haemorrhagic fever (DHF)/dengue shock syndrome (DSS). Extensive plasma leakage in various tissue spaces and serous cavities of the body, including the pleural, pericardial and peritoneal cavities in patients with DHF, may result in profound shock. Among various mechanisms that have been considered include immune complex disease, T-cell-mediated, antibodies cross-reacting with vascular endothelium, enhancing antibodies, complement and its products, various soluble mediators including cytokines, selection of virulent strains and virus virulence, but the most favoured are enhancing antibodies and memory T cells in a secondary infection resulting in cytokine tsunami. Whatever the mechanism, it ultimately targets vascular endothelium (making it a battlefield) leading to severe dengue disease. Extensive recent work has been done in vitro on endothelial cell monolayer models to understand the pathophysiology of vascular endothelium during dengue virus (DV) infection that may be translated to help understand the pathogenesis of DHF/DSS. The present review provides a broad overview of the effects of DV infection and the associated host responses contributing towards alterations in vascular endothelial cell physiology and damage that may be responsible for the DHF/DSS
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