1,267 research outputs found
Land use planning for high pressure pipelines : ground hazards from dissolution of soluble rocks
The overall permeability of each geological unit has been interpreted to produce an index of the
vulnerability of groundwater occurring in Glasgow, and provides a broad-based view of both the
vulnerability of groundwater and the location of the more permeable aquifers in Glasgow.
The data used to interpret the groundwater vulnerability index are derived from the 1:50 000
DigMap bedrock and superficial geology coverage. The GIS and associated maps should not
therefore be used at scales larger than 1:50 000. Locations of thick clays have been interpreted
and drawn based on BGS borehole records. Information on water boreholes is derived from the
British Geological Survey Scottish Water Borehole database
Concurrent sodium channelopathies and amyotrophic lateral sclerosis supports shared pathogenesis
Amyotrophic lateral sclerosis (ALS) is an invariably fatal adult-onset neurodegenerative disorder; approximately 10% of ALS is monogenic but all ALS exhibits significant heritability. The skeletal muscle sodium channelopathies are a group of inherited, non-dystrophic ion channel disorders caused by heterozygous point mutations in the SCN4A gene, leading to clinical manifestations of congenital myotonia, paramyotonia, and periodic paralysis syndromes. We provide clinical and genetic evidence of concurrence of these two rare disorders which implies a possible shared underlying pathophysiology in two patients. We then identify an enrichment of ALS-associated mutations in another sodium channel, SCN7A, from whole genome sequencing data of 4495 ALS patients and 1925 controls passing multiple testing correction (67 variants, pâ=â0.0002, Firth logistic regression). These findings suggest dysfunctional sodium channels may play a role upstream in the pathogenesis of ALS in a subset of patients, potentially opening the door to novel personalized medicine approaches
Temporal trends of time to antiretroviral treatment initiation, interruption and modification: Examination of patients diagnosed with advanced HIV in Australia
INTRODUCTION:
HIV prevention strategies are moving towards reducing plasma HIV RNA viral load in all HIV-positive persons, including those undiagnosed, treatment naĂŻve, on or off antiretroviral therapy. A proxy population for those undiagnosed are patients that present late to care with advanced HIV. The objectives of this analysis are to examine factors associated with patients presenting with advanced HIV, and establish rates of treatment interruption and modification after initiating ART.
METHODS:
We deterministically linked records from the Australian HIV Observational Database to the Australian National HIV Registry to obtain information related to HIV diagnosis. Logistic regression was used to identify factors associated with advanced HIV diagnosis. We used survival methods to evaluate rates of ART initiation by diagnosis CD4 count strata and by calendar year of HIV diagnosis. Cox models were used to determine hazard of first ART treatment interruption (duration >30 days) and time to first major ART modification.
RESULTS:
Factors associated (p<0.05) with increased odds of advanced HIV diagnosis were sex, older age, heterosexual mode of HIV exposure, born overseas and rural-regional care setting. Earlier initiation of ART occurred at higher rates in later periods (2007-2012) in all diagnosis CD4 count groups. We found an 83% (69, 91%) reduction in the hazard of first treatment interruption comparing 2007-2012 versus 1996-2001 (p<0.001), and no difference in ART modification for patients diagnosed with advanced HIV.
CONCLUSIONS:
Recent HIV diagnoses are initiating therapy earlier in all diagnosis CD4 cell count groups, potentially lowering community viral load compared to earlier time periods. We found a marked reduction in the hazard of first treatment interruption, and found no difference in rates of major modification to ART by HIV presentation status in recent periods
The self-consistent bounce: an improved nucleation rate
We generalize the standard computation of homogeneous nucleation theory at
zero temperature to a scenario in which the bubble shape is determined
self-consistently with its quantum fluctuations. Studying two scalar models in
1+1 dimensions, we find the self-consistent bounce by employing a two-particle
irreducible (2PI) effective action in imaginary time at the level of the
Hartree approximation. We thus obtain an effective single bounce action which
determines the rate exponent. We use collective coordinates to account for the
translational invariance and the growth instability of the bubble and finally
present a new nucleation rate prefactor. We compare the results with those
obtained using the standard 1-loop approximation and show that the
self-consistent rate can differ by several orders of magnitude.Comment: 28 pages, revtex, 7 eps figure
Numerical processes and mathematical anxiety in UK and Russian University students.
Mathematical anxiety (MA) has been shown to be related to poor performance in mathematics exams, as well as to avoidance of mathematical subjects in higher education and mathematics-related careers choices, even among students of high potential. This study investigated the relationship of MA and
a number of mathematically relevant cognitive traits in UK and Russian University students. The cognitive traits included number sense, spatial ability, IQ, aptitude for mathematics and knowledge of numerical vocabulary. No sex differences in levels of MA were observed. The levels of MA were also similar in the two countries. No correlations were found between MA and mathematically relevant cognitive traits. A relationship between IQ and MA was found in the Russian participant
Kinks in the Hartree approximation
The topological defects of the lambda phi^4 theory, kink and antikink, are
studied in the Hartree approximation. This allows us to discuss quantum effects
on the defects in both stationary and dynamical systems. The kink mass is
calculated for a number of parameters, and compared to classical, one loop and
Monte Carlo results known from the literature. We discuss the thermalization of
the system after a kink antikink collision. A classical result, the existence
of a critical speed, is rederived and shown for the first time in the quantum
theory. We also use kink antikink collisions as a very simple toy model for
heavy ion collisions and discuss the differences and similarities, for example
in the pressure. Finally, using the Hartree Ensemble Approximation allows us to
study kink antikink nucleation starting from a thermal (Bose Einstein)
distribution. In general our results indicate that on a qualitative level there
are few differences with the classical results, but on a quantitative level
there are some import ones.Comment: 20 pages REVTeX 4, 17 Figures. Uses amsmath.sty and subfigure.sty.
Final version, fixed typo in published versio
The Higher Derivative Expansion of the Effective Action by the String Inspired Method. Part II
We apply the string inspired worldline formalism to the calculation of the
higher derivative expansion of one-loop effective actions in non-Abelian gauge
theory. For this purpose, we have completely computerized the method, using the
symbolic manipulation programs FORM, PERL and M. Explicit results are given to
sixth order in the inverse mass expansion, reduced to a minimal basis of
invariants specifically adapted to the method. Detailed comparisons are made
with other gauge-invariant algorithms for calculating the same expansion. This
includes an explicit check of all coefficients up to fifth order.Comment: 37 pages, LaTeX, 3 figures, typos corrected, to appear in Ann. Phys.
(N.Y.
Thinking about growth : a cognitive mapping approach to understanding small business development
School of Managemen
The Clinical Translation Gap in Child Health Exercise Research: A Call for Disruptive Innovation
In children, levels of play, physical activity, and fitness are key indicators of health and
disease and closely tied to optimal growth and development. Cardiopulmonary exercise
testing (CPET) provides clinicians with biomarkers of disease and effectiveness of
therapy, and researchers with novel insights into fundamental biological mechanisms
reflecting an integrated physiological response that is hidden when the child is at rest.
Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the
current emphasis on preventative medicine and the growing recognition that therapies
used in children should be clinically tested in children. There exists a translational gap
between basic discovery and clinical application in this essential component of child
health. To address this gap, the NIH provided funding through the Clinical and
Translational Science Award (CTSA) program to convene a panel of experts. This
report summarizes our major findings and outlines next steps necessary to enhance
child health exercise medicine translational research. We present specific plans to
bolster data interoperability, improve child health CPET reference values, stimulate
formal training in exercise medicine for child health care professionals, and outline
innovative approaches through which exercise medicine can become more accessible
and advance therapeutics across the child health spectrum
Coherent states for exactly solvable potentials
A general algebraic procedure for constructing coherent states of a wide
class of exactly solvable potentials e.g., Morse and P{\"o}schl-Teller, is
given. The method, {\it a priori}, is potential independent and connects with
earlier developed ones, including the oscillator based approaches for coherent
states and their generalizations. This approach can be straightforwardly
extended to construct more general coherent states for the quantum mechanical
potential problems, like the nonlinear coherent states for the oscillators. The
time evolution properties of some of these coherent states, show revival and
fractional revival, as manifested in the autocorrelation functions, as well as,
in the quantum carpet structures.Comment: 11 pages, 4 eps figures, uses graphicx packag
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