8,883 research outputs found
Research Question, Study Design and Continuous Research Education and Training Exercises (CREATE) Program.
The clinical research project starts with identifying the optimal research question, one that is ethical, impactful, feasible, scientifically sound, novel, relevant, and interesting. The project continues with the design of the study to answer the research question. Such design should be consistent with ethical and methodological principles, and make optimal use of resources in order to have the best chances of identifying a meaningful answer to the research question. Physicians and other healthcare providers are optimally positioned to identify meaningful research questions the answer to which could make significant impact on healthcare delivery. The typical medical education curriculum, however, lacks solid training in clinical research. We propose CREATE (Continuous Research Education And Training Exercises) as a peer- and group-based, interactive, analytical, customized, and accrediting program with didactic, training, mentoring, administrative, and professional support to enhance clinical research knowledge and skills among healthcare professionals, promote the generation of original research projects, increase the chances of their successful completion and potential for meaningful impact. The key features of the program are successive intra- and inter-group discussions and confrontational thematic challenges among participating peers aimed at capitalizing on the groups' collective knowledge, experience and skills, and combined intellectual processing capabilities to optimize choice of research project elements and stakeholder decision-making
Entangled and disentangled evolution for a single atom in a driven cavity
For an atom in an externally driven cavity, we show that special initial
states lead to near-disentangled atom-field evolution, and superpositions of
these can lead to near maximally-entangled states. Somewhat counterintutively,
we find that (moderate) spontaneous emission in this system actually leads to a
transient increase in entanglement beyond the steady-state value. We also show
that a particular field correlation function could be used, in an experimental
setting, to track the time evolution of this entanglement
Clinical Research Environment in India: Challenges and Proposed Solutions.
India has compelling need and keen aspirations for indigenous clinical research. Notwithstanding this need and previously reported growth the expected expansion of Indian clinical research has not materialized. We reviewed the scientific literature, lay press reports, and ClinicalTrials.gov data for information and commentary on projections, progress, and impediments associated with clinical trials in India. We also propose targeted solutions to identified challenges. The Indian clinical trial sector grew by (+) 20.3% CAGR (compound annual growth rate) between 2005 and 2010 and contracted by (-) 14.6% CAGR between 2010 and 2013. Phase-1 trials grew by (+) 43.5% CAGR from 2005-2013, phase-2 trials grew by (+) 19.8% CAGR from 2005-2009 and contracted by (-) 12.6% CAGR from 2009-2013, and phase-3 trials grew by (+) 13.0% CAGR from 2005-2010 and contracted by (-) 28.8% CAGR from 2010-2013. This was associated with a slowing of the regulatory approval process, increased media coverage and activist engagement, and accelerated development of regulatory guidelines and recuperative initiatives. We propose the following as potential targets for restorative interventions: Regulatory overhaul (leadership and enforcement of regulations, resolution of ambiguity in regulations, staffing, training, guidelines, and ethical principles [e.g., compensation]).Education and training of research professionals, clinicians, and regulators.Public awareness and empowerment. After a peak in 2009-2010, the clinical research sector in India appears to be experiencing a contraction. There are indications of challenges in regulatory enforcement of guidelines; training of clinical research professionals; and awareness, participation, partnership, and the general image amongst the non-professional media and public. Preventative and corrective principles and interventions are outlined with the goal of realizing the clinical research potential in India
Gaugino Condensation in M-theory on S^1/Z_2
In the low energy limit of for M-theory on S^1/Z_2, we calculate the gaugino
condensate potential in four dimensions using the background solutions due to
Horava. We show that this potential is free of delta-function singularities and
has the same form as the potential in the weakly coupled heterotic string. A
general flux quantization rule for the three-form field of M-theory on S^1/Z_2
is given and checked in certain limiting cases. This rule is used to fix the
free parameter in the potential originating from a zero mode of the form field.
Finally, we calculate soft supersymmetry breaking terms. We find that
corrections to the Kahler potential and the gauge kinetic function, which can
be large in the strongly coupled region, contribute significantly to certain
soft terms. In particular, for supersymmetry breaking in the T-modulus
direction, the small values of gaugino masses and trilinear couplings that
occur in the weakly coupled, large radius regime are enhanced to order m_3/2 in
M-theory. The scalar soft masses remain small even, in the strong coupling
M-theory limit.Comment: 20 pages, LATE
Social Cohesion, Structural Holes, and a Tale of Two Measures
EMBARGOED - author can archive pre-print or post-print on any open access repository after 12 months from publication. Publication date is May 2013 so embargoed until May 2014.This is an author’s accepted manuscript (deposited at arXiv arXiv:1211.0719v2 [physics.soc-ph] ), which was subsequently published in Journal of Statistical Physics May 2013, Volume 151, Issue 3-4, pp 745-764. The final publication is available at link.springer.com http://link.springer.com/article/10.1007/s10955-013-0722-
Cosmological Solutions of Horava-Witten Theory
We discuss simple cosmological solutions of Horava-Witten theory describing
the strongly coupled heterotic string. At energies below the grand-unified
scale, the effective theory is five- not four-dimensional, where the additional
coordinate parameterizes a S^1/Z_2 orbifold. Furthermore, it admits no
homogeneous solutions. Rather, the vacuum state, appropriate for a reduction to
four-dimensional supersymmetric models, is a BPS domain wall. Relevant
cosmological solutions are those associated with this BPS state. In particular,
such solutions must be inhomogeneous, depending on the orbifold coordinate as
well as on time. We present two examples of this new type of cosmological
solution, obtained by separation of variables rather that by exchange of time
and radius coordinate applied to a brane solution, as in previous work. The
first example represents the analog of a rolling radii solution with the radii
specifying the geometry of the domain wall. This is generalized in the second
example to include a nontrivial ``Ramond-Ramond'' scalar.Comment: 21 pages, Latex 2e with amsmath, minor addition
Crab cavities for linear colliders
Crab cavities have been proposed for a wide number of accelerators and
interest in crab cavities has recently increased after the successful operation
of a pair of crab cavities in KEK-B. In particular crab cavities are required
for both the ILC and CLIC linear colliders for bunch alignment. Consideration
of bunch structure and size constraints favour a 3.9 GHz superconducting,
multi-cell cavity as the solution for ILC, whilst bunch structure and
beam-loading considerations suggest an X-band copper travelling wave structure
for CLIC. These two cavity solutions are very different in design but share
complex design issues. Phase stabilisation, beam loading, wakefields and mode
damping are fundamental issues for these crab cavities. Requirements and
potential design solutions will be discussed for both colliders.Comment: 3 pages. To be published in proceedings of LINAC 2008, Victoria,
Canad
Population Size, Sex and Purifying Selection: Comparative Genomics of Two Sister Taxa of the Wild Yeast Saccharomyces paradoxus
This study uses population genomic data to estimate demographic and selection parameters in two sister lineages of the wild yeast Saccharomyces paradoxus and compare their evolution. We first estimate nucleotide and recombinational diversities in each of the two lineages to infer their population size and frequency of sex and then analyze the rate of mutation accumulation since divergence from their inferred common ancestor to estimate the generation time and efficacy of selection. We find that one of the lineages has significantly higher silent nucleotide diversity and lower linkage disequilibrium, indicating a larger population with more frequent sexual generations. The same lineage also shows shorter generation time and higher efficacy of purifying selection, the latter consistent with the finding of larger population size and more frequent sex. Similar analyses are also performed on the ancestries of individual strains within lineages and we find significant differences between strains implying variation in rates of mitotic cell divisions. Our sample includes some strains originating in the Chernobyl nuclear-accident exclusion zone, which has been subjected to high levels of radiation for nearly 30 years now. We find no evidence, however, for increased rates of mutation. Finally, there is a positive correlation between rates of mutation accumulation and length of growing period, as measured by latitude of the place of origin of strains. Our study illustrates the power of genomic analyses in estimating population and life history parameters and testing predictions based on population genetic theory
Heterotic M-Theory Cosmology in Four and Five Dimensions
We study rolling radii solutions in the context of the four- and
five-dimensional effective actions of heterotic M-theory. For the standard
four-dimensional solutions with varying dilaton and T-modulus, we find
approximate five-dimensional counterparts. These are new, generically
non-separating solutions corresponding to a pair of five-dimensional domain
walls evolving in time. Loop corrections in the four-dimensional theory are
described by certain excitations of fields in the fifth dimension. We point out
that the two exact separable solutions previously discovered are precisely the
special cases for which the loop corrections are time-independent. Generically,
loop corrections vary with time. Moreover, for a subset of solutions they
increase in time, evolving into complicated, non-separating solutions. In this
paper we compute these solutions to leading, non-trivial order. Using the
equations for the induced brane metric, we present a general argument showing
that the accelerating backgrounds of this type cannot evolve smoothly into
decelerating backgrounds.Comment: 15 pages, Latex, 1 eps figur
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