1,420 research outputs found
An Estimate of alpha_S from Bottomonium in Unquenched QCD
We estimate the strong coupling constant from the perturbative expansion of
the plaquette. The scale is set by the 2S-1S and 1P-1S splittings in
bottomonium which are computed in NRQCD on dynamical gauge configurations with
nf=2 degenerate Wilson quarks at intermediate masses. We have increased the
statistics of our spectrum calculation in order to reliably extrapolate in the
sea-quark mass. We find a value of alpha_MS(m_Z) = 0.1118(26) which is somewhat
lower than previous estimates within NRQCD.Comment: LATTICE98(heavyqk
Improving Stochastic Estimator Techniques for Disconnected Diagrams
Disconnected diagrams are expected to be sensitive to the inclusion of
dynamical fermions. We present a feasibility study for the observation of such
effects on the nucleonic matrix elements of the axial vector current, using
SESAM full QCD vacuum configurations with Wilson fermions on
lattices, at . Starting from the standard methods developed by the
Kentucky and Tsukuba groups, we investigate the improvement from various
refinements thereof.Comment: One author added. Contribution to Lattice 1997, 3 pages LaTex, to
appear in Nucl. Phys. B (Proc. Suppl.
Light Quark Physics with Dynamical Wilson Fermions
We present results for spectroscopy, quark masses and decay constants
obtained from SESAM's and TkL's large statistics simulations of QCD with two
dynamical Wilson fermions.Comment: 3 pages; to appear in the proceedings of Lat.'9
Glueballs and string breaking from full QCD
We present results on the static potential, and torelon and glueball masses
from simulations of QCD with two flavours of dynamical Wilson fermions on
and lattices at .Comment: Talk presented by Gunnar Bali at International Symposium on Lattice
Field Theories (Lattice 97), Edinburgh, July 1997, 3 pages LaTeX
(epscrc2.sty) with 4 eps figure
Light Quark Masses with Dynamical Wilson Fermions
We determine the masses of the light and the strange quarks in the
-scheme using our high-statistics lattice simulation of QCD with
dynamical Wilson fermions. For the light quark mass we find
, which is lower than in quenched
simulations. For the strange quark, in a sea of two dynamical light quarks, we
obtain .Comment: 10 pages (latex file, uses epsf-style
The Perceived Tightness Scale Does Not Provide Reliable Estimates of Blood Flow Restriction Pressure.
CONTEXT: The perceived tightness scale is suggested to be an effective method for setting subocclusive pressures with practical blood flow restriction. However, the reliability of this scale is unknown and is important as the reliability will ultimately dictate the usefulness of this method.
OBJECTIVE: To determine the reliability of the perceived tightness scale and investigate if the reliability differs by sex.
DESIGN: Within-participant, repeated-measures.
SETTING: University laboratory.
PARTICIPANTS: Twenty-four participants (12 men and 12 women) were tested over 3 days.
MAIN OUTCOME MEASURES: Arterial occlusion pressure (AOP) and the pressure at which the participants rated a 7 out of 10 on the perceived tightness scale in the upper arm and upper leg.
RESULTS: The percentage coefficient of variation for the measurement was approximately 12%, with no effect of sex in the upper (median δ [95% credible interval]: 0.016 [-0.741, 0.752]) or lower body (median δ [95% credible interval]: 0.266 [-0.396, 0.999]). This would produce an overestimation/underestimation of ∼25% from the mean perceived pressure in the upper body and ∼20% in the lower body. Participants rated pressures above their AOP for the upper body and below for the lower body. At the group level, there were differences in participants\u27 ratings for their relative AOP (7 out of 10) between day 1 and days 2 and 3 for the lower body, but no differences between sexes for the upper or lower body.
CONCLUSIONS: The use of the perceived tightness scale does not provide reliable estimates of relative pressures over multiple visits. This method resulted in a wide range of relative AOPs within the same individual across days. This may preclude the use of this scale to set the pressure for those implementing practical blood flow restriction in the laboratory, gym, or clinic
The perceived tightness scale does not provide reliable estimates of blood flow restriction pressure
© 2020 Human Kinetics, Inc. Context: The perceived tightness scale is suggested to be an effective method for setting subocclusive pressures with practical blood flow restriction. However, the reliability of this scale is unknown and is important as the reliability will ultimately dictate the usefulness of this method. Objective: To determine the reliability of the perceived tightness scale and investigate if the reliability differs by sex. Design: Within-participant, repeated-measures. Setting: University laboratory. Participants: Twenty-four participants (12 men and 12 women) were tested over 3 days. Main Outcome Measures: Arterial occlusion pressure (AOP) and the pressure at which the participants rated a 7 out of 10 on the perceived tightness scale in the upper arm and upper leg. Results: The percentage coefficient of variation for the measurement was approximately 12%, with no effect of sex in the upper (median δ [95% credible interval]: 0.016 [-0.741, 0.752]) or lower body (median δ [95% credible interval]: 0.266 [-0.396, 0.999]). This would produce an overestimation/underestimation of ∼25% from the mean perceived pressure in the upper body and ∼20% in the lower body. Participants rated pressures above their AOP for the upper body and below for the lower body. At the group level, there were differences in participants’ ratings for their relative AOP (7 out of 10) between day 1 and days 2 and 3 for the lower body, but no differences between sexes for the upper or lower body. Conclusions: The use of the perceived tightness scale does not provide reliable estimates of relative pressures over multiple visits. This method resulted in a wide range of relative AOPs within the same individual across days. This may preclude the use of this scale to set the pressure for those implementing practical blood flow restriction in the laboratory, gym, or clinic
Decorrelating Topology with HMC
The investigation of the decorrelation efficiency of the HMC algorithm with
respect to vacuum topology is a prerequisite for trustworthy full QCD
simulations, in particular for the computation of topology sensitive
quantities. We demonstrate that for mpi/mrho ratios <= 0.69 sufficient
tunneling between the topological sectors can be achieved, for two flavours of
dynamical Wilson fermions close to the scaling region beta=5.6. Our results are
based on time series of length 5000 trajectories.Comment: change of comments: LATTICE98(confine
Light and Strange Hadron Spectroscopy with Dynamical Wilson Fermions
We present the final analysis of the light and strange hadron spectra from a full QCD lattice simulation with two degenerate dynamical sea quark flavours at corresponding to the range are investigated. For reference we also ran a quenched simulation at , which is the point of equal lattice spacing, . In the light sector, we find the chiral extrapolation to physical u- and d- masses to present a major source of uncertainty, comparable to the expected size of unquenching effects. From linear and quadratic fits we can estimate the errors on the hadron masses made from light quarks to be on a 15 % level prior to the continuum extrapolation. For the hadrons with strange valence quark content, the approximation to QCD appears not to cure the well-known failure of quenched QCD to reproduce the physical splitting
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