422 research outputs found
Evidencias sobre los factores de riesgo del síndrome de hombro doloroso en deportistas: una revisión de alcance
Objective: To investigate the available evidence on the risk factors (RF) of shoulder pain syndrome (SPS) in athletes.
Methodology: A scope review was carried out, following the criteria of the PRISMA declaration. The search was limited in Pubmed, WOS and Scopus.
Results: Nine studies were included, two discussed the RFs of shoulder pain from overuse of the upper extremity (UE); two other studies referred to playing position, and the remaining four studies have no RF in common. It was mainly found that the development of shoulder pain involves multiple factors and mechanisms; however, a predominant RF could be determined, which was the excessive use of the EU.
Conclusion: This scope review confirmed the high prevalence of shoulder pain in athletes and the most frequent RF; despite this, studies on causality or preventive measures are still lacking.Objetivo: Investigar acerca de las evidencias disponibles sobre los factores de riesgo (FR) del síndrome de hombro doloroso (SHD) en deportistas.
Metodología: Se realizó una revisión de alcance, siguiendo los criterios de la declaración PRISMA. La búsqueda fue limitada en Pubmed, WOS y Scopus.
Resultados: Se incluyeron 9 estudios, dos discutieron los FR del dolor de hombro por el uso excesivo de la extremidad superior (EESS); otros dos estudios se refirieron a la posición de juego, y los otros cuatro estudios restantes no tienen FR en común. Se encontró principalmente que el desarrollo del dolor de hombro involucra múltiples factores y mecanismos; sin embargo, se pudo determinar un FR predominante, que fue el uso excesivo de la EESS.
Conclusión: Esta revisión de alcance confirmó la alta prevalencia de dolor de hombro en deportistas y los FR más frecuentes; a pesar de ello, siguen faltando estudios sobre la causalidad o medidas preventivas
Top quark tensor couplings
We compute the real and imaginary parts of the one-loop electroweak
contributions to the left and right tensorial anomalous couplings of the
vertex in the Standard Model (SM). For both tensorial couplings we find that
the real part of the electroweak SM correction is close to 10 of the leading
contribution given by the QCD gluon exchange. We also find that the electroweak
real and imaginary parts for the anomalous right coupling are almost of the
same order of magnitude. The one loop SM prediction for the real part of the
left coupling is close to the 3 discovery limit derived from
. Besides, taking into account that the predictions of
new physics interactions are also at the level of a few percents when compared
with the one loop QCD gluon exchange, these electroweak corrections should be
taken into account in order to disentangle new physics effects from the
standard ones. These anomalous tensorial couplings of the top quark will be
investigated at the LHC in the near future where sensitivity to these
contributions may be achieved.Comment: 16 pages, 2 figure
Quantum States and Phases in Driven Open Quantum Systems with Cold Atoms
An open quantum system, whose time evolution is governed by a master
equation, can be driven into a given pure quantum state by an appropriate
design of the system-reservoir coupling. This points out a route towards
preparing many body states and non-equilibrium quantum phases by quantum
reservoir engineering. Here we discuss in detail the example of a \emph{driven
dissipative Bose Einstein Condensate} of bosons and of paired fermions, where
atoms in an optical lattice are coupled to a bath of Bogoliubov excitations via
the atomic current representing \emph{local dissipation}. In the absence of
interactions the lattice gas is driven into a pure state with long range order.
Weak interactions lead to a weakly mixed state, which in 3D can be understood
as a depletion of the condensate, and in 1D and 2D exhibits properties
reminiscent of a Luttinger liquid or a Kosterlitz-Thouless critical phase at
finite temperature, with the role of the ``finite temperature'' played by the
interactions.Comment: 9 pages, 2 figure
Design and fabrication of gas cell targets for laboratory astrophysics experiments on the Orion high-power laser facility
This paper describes the design and fabrication of a range of ‘gas cell’ microtargets produced by the Target Fabrication Group in the Central Laser Facility (CLF) for academic access experiments on the Orion laser facility at the Atomic Weapons Establishment (AWE). The experiments were carried out by an academic consortium led by Imperial College London. The underlying target methodology was an evolution of a range of targets used for experiments on radiative shocks and involved the fabrication of a precision machined cell containing a number of apertures for interaction foils or diagnostic windows. The interior of the cell was gas-filled before laser irradiation. This paper details the assembly processes, thin film requirements and micro-machining processes needed to produce the targets. Also described is the implementation of a gas-fill system to produce targets that are filled to a pressure of 0.1–1 bar. The paper discusses the challenges that are posed by such a target
Dynamics of a Quantum Phase Transition and Relaxation to a Steady State
We review recent theoretical work on two closely related issues: excitation
of an isolated quantum condensed matter system driven adiabatically across a
continuous quantum phase transition or a gapless phase, and apparent relaxation
of an excited system after a sudden quench of a parameter in its Hamiltonian.
Accordingly the review is divided into two parts. The first part revolves
around a quantum version of the Kibble-Zurek mechanism including also phenomena
that go beyond this simple paradigm. What they have in common is that
excitation of a gapless many-body system scales with a power of the driving
rate. The second part attempts a systematic presentation of recent results and
conjectures on apparent relaxation of a pure state of an isolated quantum
many-body system after its excitation by a sudden quench. This research is
motivated in part by recent experimental developments in the physics of
ultracold atoms with potential applications in the adiabatic quantum state
preparation and quantum computation.Comment: 117 pages; review accepted in Advances in Physic
Entanglement in solvable many-particle models
Lecture notes for the Brazilian School on Statistical Mechanics, Natal,
Brazil, July 2011.
The five lectures introduce to the description of entanglement in
many-particle systems and review the ground-state entanglement features of
standard solvable lattice models. This is done using a thermodynamic
formulation in which the eigenvalue spectrum of a certain Hamiltonian
determines the entanglement properties. The methods to obtain it are discussed
and results, both analytical and numerical, for various cases including time
evolution are presented.Comment: 44 pages, 30 figures. Lecture notes for the Brazilian School on
Statistical Mechanics, Natal, July 2011. For the Brazilian Journal of Physic
Association of MC1R Variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study
<p><b>Background</b> Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited.</p>
<p><b>Methods</b> We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, ≥2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided.</p>
<p><b>Results</b> Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 × 10−6 ≤ P ≤ .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; Ptrend = 1.86 × 10−8). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 ≤ P ≤ .04), hair color (.006 ≤ P ≤ .06), and number of nevi (6.9 × 10−6 ≤ P ≤ .02).</p>
<p><b>Conclusion</b> Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.</p>
Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF
If the Technicolor omega_T particle exists, a likely decay mode is omega_T ->
gamma pi_T, followed by pi_T -> bb-bar, yielding the signature gamma bb-bar. We
have searched 85 pb^-1 of data collected by the CDF experiment at the Fermilab
Tevatron for events with a photon and two jets, where one of the jets must
contain a secondary vertex implying the presence of a b quark. We find no
excess of events above standard model expectations. We express the result of an
exclusion region in the M_omega_T - M_pi_T mass plane.Comment: 14 pages, 2 figures. Available from the CDF server (PS with figs):
http://www-cdf.fnal.gov/physics/pub98/cdf4674_omega_t_prl_4.ps
FERMILAB-PUB-98/321-
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A Search for Dark Higgs Bosons
Recent astrophysical and terrestrial experiments have motivated the proposal
of a dark sector with GeV-scale gauge boson force carriers and new Higgs
bosons. We present a search for a dark Higgs boson using 516 fb-1 of data
collected with the BABAR detector. We do not observe a significant signal and
we set 90% confidence level upper limits on the product of the Standard
Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots
for b/w printin
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
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