45,748 research outputs found
Mesons and Nucleons in Soft-Wall AdS/QCD with Constrained Infrared Background
The purpose of this paper is to further study the soft-wall AdS/QCD model
with constrained IR background. By including a quartic bulk scalar potential we
study various meson and nucleon spectra. This model naturally realizes the
asymptotical linearity of these mass spectra simultaneously, together with
correctly pattern of explicit and dynamical chiral symmetry breaking. The
agreement between the theoretical calculations and the experimental data is
good.Comment: 17 pages,5 table
Magnitude and Sign Correlations in Heartbeat Fluctuations
We propose an approach for analyzing signals with long-range correlations by
decomposing the signal increment series into magnitude and sign series and
analyzing their scaling properties. We show that signals with identical
long-range correlations can exhibit different time organization for the
magnitude and sign. We find that the magnitude series relates to the nonlinear
properties of the original time series, while the sign series relates to the
linear properties. We apply our approach to the heartbeat interval series and
find that the magnitude series is long-range correlated, while the sign series
is anticorrelated and that both magnitude and sign series may have clinical
applications.Comment: 4 pages,late
Mechanisms of pelvic floor muscle function and the effect on the urethra during a cough
Background: Current measurement tools have difficulty identifying the automaticphysiologic processes maintaining continence, and many questions still remainabout pelvic floor muscle (PFM) function during automatic events.Objective: To perform a feasibility study to characterise the displacement, velocity,and acceleration of the PFM and the urethra during a cough.Design, setting, and participants: A volunteer convenience sample of 23 continentwomen and 9 women with stress urinary incontinence (SUI) from the generalcommunity of San Francisco Bay Area was studied.Measurements: Methods included perineal ultrasound imaging, motion trackingof the urogenital structures, and digital vaginal examination. Statistical analysisused one-tailed unpaired student t tests, and Welch’s correction was applied whenvariances were unequal.Results and limitations: The cough reflex activated the PFM of continent women tocompress the urogenital structures towards the pubic symphysis, which wasabsent in women with SUI. The maximum accelerations that acted on the PFMduring a cough were generally more similar than the velocities and displacements.The urethras of women with SUI were exposed to uncontrolled transverse accelerationand were displaced more than twice as far ( p = 0.0002), with almost twicethe velocity ( p = 0.0015) of the urethras of continent women. Caution regardingthe generalisability of this study is warranted due to the small number of women inthe SUI group and the significant difference in parity between groups.Conclusions: During a cough, normal PFM function produces timely compressionof the pelvic floor and additional external support to the urethra, reducing displacement,velocity, and acceleration. In women with SUI, who have weakerurethral attachments, this shortening contraction does not occur; consequently,the urethras of women with SUI move further and faster for a longer duratio
Free Quarks and Antiquarks versus Hadronic Matter
Meson-meson reactions A(q_1 \bar{q}_1) + B(q_2 \bar{q}_2) to q_1 + \bar{q}_1
+ q_2 + \bar{q}_2 in high-temperature hadronic matter are found to produce an
appreciable amount of quarks and antiquarks freely moving in hadronic matter
and to establish a new mechanism for deconfinement of quarks and antiquarks in
hadronic matter.Comment: 9 pages, 3 figure
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