1,765 research outputs found
Skill policies for Scotland
This paper argues that skill formation is a life-cycle process and develops the
implications of this insight for Scottish social policy. Families are major
producers of skills, and a successful policy needs to promote effective families
and to supplement failing ones. Targeted early interventions have proven to be
very effective in compensating for the effect of neglect. Improvements in
traditional measures of school quality, tuition subsidies, company-sponsored
and public job training are unlikely to be as effective. We review the evidence
and present several policy recommendations
Transport Properties of Strong-Interaction Matter
The properties of strong-interaction matter are probed in ultra-relativistic
heavy-ion collisions. In the context of measurements of the elliptic flow at
RHIC and the LHC the shear viscosity is of particular interest. In this
presentation we discuss recent results for eta/s in hadronic matter at
vanishing baryo-chemical potential within kinetic theory. Using the
Nambu-Jona-Lasinio model, special attention is paid to effects arising from the
restoration of spontaneously broken chiral symmetry with increasing
temperature.Comment: 8 pages, 4 figures, presented at the HIC for FAIR Workshop and XXVIII
Max Born Symposium "Three days on Quarkyonic Island", Wroclaw, May 19-21,
2011; v2: conversion to Pa in fig. 2 correcte
A study of higher dimensional inhomogeneous cosmological model
In this paper we present a class of exact inhomogeneous solutions to
Einstein's equations for higher dimensional Szekeres metric with perfect fluid
and a cosmological constant. We also show particular solutions depending on the
choices of various parameters involved and for dust case. Finally, we examine
the asymptotic behaviour of some of these solutions.Comment: 9 Latex pages, No figure, Revtex styl
Newtonian and Post-Newtonian approximations of the k = 0 Friedmann Robertson Walker Cosmology
In a previous paper we derived a post-Newtonian approximation to cosmology
which, in contrast to former Newtonian and post-Newtonian cosmological
theories, has a well-posed initial value problem. In this paper, this new
post-Newtonian theory is compared with the fully general relativistic theory,
in the context of the k = 0 Friedmann Robertson Walker cosmologies. It is found
that the post-Newtonian theory reproduces the results of its general
relativistic counterpart, whilst the Newtonian theory does not.Comment: 11 pages, Latex, corrected typo
Schwarzschild and Synge once again
We complete the historical overview about the geometry of a Schwarzschild
black hole at its horizon by emphasizing the contribution made by J. L. Synge
in 1950 to its clarification.Comment: 2 pages, LaTeX, submitted for publication; 2 references, one Note,
and an Acknowledgement are adde
On the Significance of the Weyl Curvature in a Relativistic Cosmological Model
The Weyl curvature includes the Newtonian field and an additional field, the
so-called anti-Newtonian. In this paper, we use the Bianchi and Ricci
identities to provide a set of constraints and propagations for the Weyl
fields. The temporal evolutions of propagations manifest explicit solutions of
gravitational waves. We see that models with purely Newtonian field are
inconsistent with relativistic models and obstruct sounding solutions.
Therefore, both fields are necessary for the nonlocal nature and radiative
solutions of gravitation.Comment: 15 pages, incorporating proof correction
Can noncommutativity resolve the Big-Bang singularity?
A possible way to resolve the singularities of general relativity is proposed
based on the assumption that the description of space-time using commuting
coordinates is not valid above a certain fundamental scale. Beyond that scale
it is assumed that the space-time has noncommutative structure leading in turn
to a resolution of the singularity. As a first attempt towards realizing the
above programme a modification of the Kasner metric is constructed which is
commutative only at large time scales. At small time scales, near the
singularity, the commutation relations among the space coordinates diverge. We
interpret this result as meaning that the singularity has been completely
delocalized.Comment: Latex, 13 pages, 2 figures, accepted for publication in EPJ
Incidence of seropositive myasthenia gravis in Cape Town and South Africa
Background. Myasthenia gravis (MG) is a treatable autoimmune disease characterised by fatiguable weakness of skeletal muscles. More than 85% of MG patients have antibodies to the acetylcholine receptor (AChR) at the neuromuscular junction or are seropositive for MG (SPMG). In the developed world the incidence of MG has increased, particularly among older individuals, but no epidemiological studies have been done on SPMG in Africa.
Objectives. To determine the annual incidence rate (IR) of SPMG in the Cape Town (CT) municipality, and the crude annual IR of SPMG for the whole of South Africa (SA).
Methods. Positive AChR antibody tests were identified between 1 January 2003 and 1 January 2005 for patients living in CT, and the age- and sex-specific incidences were calculated. To determine the national crude annual IR over the same period, positive assays were identified from the laboratories that process AChR assays for SA. National Census 2001 population statistics formed the denominators.
Results. There were 65 positive assays in CT, and 230 nationwide. Based on these figures the annual IR for CT was 11.2 per million per year (95% confidence interval (CI) 8.7 - 14.3), and for South Africa 2.6 per million / year (95% CI 2.2 - 2.9). After a questionnaire response from CT neurologists regarding the routine use of the AChR antibody assay, the annual IR for CT was adjusted to 12.6 per million (95% CI 9.9 - 15.9) to incorporate those presumed to have SPMG without a confirmatory test. In CT, the IR in females was 15.3 per million / year (95% CI 11.2 - 20.4), and in males, 6.8 per million / year (95% CI 4.1 - 10.7). The CT IRs for blacks, coloureds and whites were not statistically different after adjusting for age and gender. The IR of SPMG in CT was 6 times greater in those presenting after the age of 50 years than in those with earlier disease onset (95% CI 3.7 - 9.7).
Conclusions. The annual IR of SPMG in CT is much the same as rates recorded recently in other developed countries, but the rest of SA has a much lower IR. A preponderance of MG starting after the age of 50 years reflects a worldwide trend, although the CT data showed a relatively lower-than-expected incidence for older males. IRs for SPMG vary widely in different regions in SA; this is likely to be related to differences in regional health care delivery, and underdiagnosis
Deep learning allows genome-scale prediction of Michaelis constants from structural features
AU The:Michaelis Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly constant KM describes the affinity of an enzyme : for a specific substrate and is a central parameter in studies of enzyme kinetics and cellular physiology. As measurements of KM are often difficult and time-consuming, experimental estimates exist for only a minority of enzyme–substrate combinations even in model organisms. Here, we build and train an organism-independent model that successfully predicts KM values for natural enzyme–substrate combinations using machine and deep learning methods. Predictions are based on a task-specific molecular fingerprint of the substrate, generated using a graph neural network, and on a deep numerical representation of the enzyme’s amino acid sequence. We provide genome-scale KM predictions for 47 model organisms, which can be used to approximately relate metabolite concentrations to cellular physiology and to aid in the parameterization of kinetic models of cellular metabolism
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