4,660 research outputs found
On Understanding Indian Philosophical Thinking
Professor Potter interprets Indian philosophy as mainly concerned with moksa or transcendental freedom. Professor Riepe offers a Marxist interpretation of Indian philosophy. The aim of this paper is to identify the strengths and limitations of each of these two views
SU(N) Coherent States
We generalize Schwinger boson representation of SU(2) algebra to SU(N) and
define coherent states of SU(N) using bosonic harmonic
oscillator creation and annihilation operators. We give an explicit
construction of all (N-1) Casimirs of SU(N) in terms of these creation and
annihilation operators. The SU(N) coherent states belonging to any irreducible
representations of SU(N) are labelled by the eigenvalues of the Casimir
operators and are characterized by (N-1) complex orthonormal vectors describing
the SU(N) manifold. The coherent states provide a resolution of identity,
satisfy the continuity property, and possess a variety of group theoretic
properties.Comment: 25 pages, LaTex, no figure
Risk models and scores for type 2 diabetes: Systematic review
This article is published under a Creative Commons Attribution Non Commercial (CC BY-NC 3.0) licence that allows reuse subject only to the use being non-commercial and to the article being fully attributed (http://creativecommons.org/licenses/by-nc/3.0).Objective - To evaluate current risk models and scores for type 2 diabetes and inform selection and implementation of these in practice.
Design - Systematic review using standard (quantitative) and realist (mainly qualitative) methodology.
Inclusion - criteria Papers in any language describing the development or external validation, or both, of models and scores to predict the risk of an adult developing type 2 diabetes.
Data sources - Medline, PreMedline, Embase, and Cochrane databases were searched. Included studies were citation tracked in Google Scholar to identify follow-on studies of usability or impact.
Data extraction - Data were extracted on statistical properties of models, details of internal or external validation, and use of risk scores beyond the studies that developed them. Quantitative data were tabulated to compare model components and statistical properties. Qualitative data were analysed thematically to identify mechanisms by which use of the risk model or score might improve patient outcomes.
Results - 8864 titles were scanned, 115 full text papers considered, and 43 papers included in the final sample. These described the prospective development or validation, or both, of 145 risk prediction models and scores, 94 of which were studied in detail here. They had been tested on 6.88 million participants followed for up to 28 years. Heterogeneity of primary studies precluded meta-analysis. Some but not all risk models or scores had robust statistical properties (for example, good discrimination and calibration) and had been externally validated on a different population. Genetic markers added nothing to models over clinical and sociodemographic factors. Most authors described their score as “simple” or “easily implemented,” although few were specific about the intended users and under what circumstances. Ten mechanisms were identified by which measuring diabetes risk might improve outcomes. Follow-on studies that applied a risk score as part of an intervention aimed at reducing actual risk in people were sparse.
Conclusion - Much work has been done to develop diabetes risk models and scores, but most are rarely used because they require tests not routinely available or they were developed without a specific user or clear use in mind. Encouragingly, recent research has begun to tackle usability and the impact of diabetes risk scores. Two promising areas for further research are interventions that prompt lay people to check their own diabetes risk and use of risk scores on population datasets to identify high risk “hotspots” for targeted public health interventions.Tower Hamlets, Newham, and City and Hackney primary care trusts and National
Institute of Health Research
XMM-Newton observations of SDSS J143030.22001115.1: an unusually flat spectrum AGN
We present XMM observations of the AGN SDSS 1430-0011. The low S/N spectrum
of this source obtained in a snap shot Chandra observation showed an unusually
flat continuum. With the follow up XMM observations we find that the source
spectrum is complex; it either has an ionized absorber or a partially covering
absorber. The underlying power-law is in the normal range observed for AGNs.
The low luminosity of the source during Chandra observations can be understood
in terms of variations in the absorber properties. The X-ray and optical
properties of this source are such that it cannot be securely classified as
either a narrow line Seyfert 1 or a broad line Seyfert 1 galaxy.Comment: Submitted to A
From Black Holes to Glueballs: The QCD_3 Tensor Glueball at Strong Coupling
A strong coupling calculation of glueball masses based on the duality between
supergravity and Yang-Mills theory is presented. Earlier work is extended to
non-zero spin. Fluctuations in the gravitational metric lead to the 2^{++}
state on the leading Pomeron trajectory with a mass relation: m(0^{++}) <
m(2^{++}) < m(1^{-+}). Contrary to expectation, the mass of our new 0^{++}
state (m^2=5.4573) associated with the graviton is smaller than the mass of the
state (m^2=11.588) from the dilaton, which in fact is exactly
degenerate with the tensor 2^{++}.Comment: 3 pages, 1 figure, Talk at Lattice 99 by R. Browe
The information paradox: A pedagogical introduction
The black hole information paradox is a very poorly understood problem. It is
often believed that Hawking's argument is not precisely formulated, and a more
careful accounting of naturally occurring quantum corrections will allow the
radiation process to become unitary. We show that such is not the case, by
proving that small corrections to the leading order Hawking computation cannot
remove the entanglement between the radiation and the hole. We formulate
Hawking's argument as a `theorem': assuming `traditional' physics at the
horizon and usual assumptions of locality we will be forced into mixed states
or remnants. We also argue that one cannot explain away the problem by invoking
AdS/CFT duality. We conclude with recent results on the quantum physics of
black holes which show the the interior of black holes have a `fuzzball'
structure. This nontrivial structure of microstates resolves the information
paradox, and gives a qualitative picture of how classical intuition can break
down in black hole physics.Comment: 38 pages, 7 figures, Latex (Expanded form of lectures given at CERN
for the RTN Winter School, Feb 09), typo correcte
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