948 research outputs found

    USING NONINVASIVE CALIBRATED CUFF PLETHYSMOGRAPHY TO OBSERVE THE EFFECTS OF COLD-WATER IMMERSION ON ARTERIAL COMPLIANCE

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    As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological response to cold exposure and endothelial function encourage further study of the effects of ice plunging on cardiovascular health. Calibrated cuff plethysmography is a promising method of reflecting on endothelial function by measuring arterial compliance of select blood vessels. In this study, a calibrated cuff plethysmography device was built and tested for efficiency as it was used to measure compliance and cross-sectional area of the brachial artery of 14 participants 30 minutes before, immediately after, and 30 minutes after a 5-minute cold plunge in a temperature of 10°C - 15°C. Results found some significant differences between baseline measurements recorded immediately after the ice plunge and measurements recorded during reactive hyperemia conditions at normal body temperature but did not conclude that 5-minute cold-water immersion intervention had a significant impact on arterial compliance or area overall since this was a short term experiment with only acute intervention methods. The device used was concluded to effectively measure arterial compliance and area

    Using Noninvasive Calibrated Cuff Plethysmography to Observe the Effects of Cold-Water Immersion on Arterial Compliance

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    As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological response to cold exposure and endothelial function encourage further study of the effects of ice plunging on cardiovascular health. Calibrated cuff plethysmography is a promising method of reflecting on endothelial function by measuring arterial compliance of select blood vessels. In this study, a calibrated cuff plethysmography device was built and tested for efficiency as it was used to measure compliance and cross-sectional area of the brachial artery of 14 participants 30 minutes before, immediately after, and 30 minutes after a 5-minute cold plunge in a temperature of 10°C - 15°C. Results found some significant differences between baseline measurements recorded immediately after the ice plunge and measurements recorded during reactive hyperemia conditions at normal body temperature but did not conclude that 5-minute cold-water immersion intervention had a significant impact on arterial compliance or area overall since this was a short term experiment with only acute intervention methods. The device used was concluded to effectively measure arterial compliance and area

    An Algorithm for the Simulations of the Magnetized Neutron Star Cooling

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    The model and algorithm for the cooling of the magnetized neutron stars are presented. The cooling evolution described by system of parabolic partial differential equations with non-linear coefficients is solved using Alternating Direction Implicit method. The difference scheme and the preliminary results of simulations are presented.Comment: 6 pages, 4 figures, accepted to the European Physical Journal Web of Conferences as a contribution of the International Conference Mathematical Modeling and Computational Physics 2015 (High Tatra Mountains, Slovakia, July 13 - July 17, 2015, http://web.tuke.sk/mmcp/mmcp2015/

    Design-Simulation-Optimization Package For A Generic 6-DOF Manipulator With A Spherical Wrist

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    Robot manipulators are built to meet certain predetermined performance requirements. The question of whether the robot will have the desired functionality (e.g. dexterity, accuracy, reliability, speed, etc.) needs to be answered before the robot is actualThis is an Author's Original Manuscript of an Article submitted for consideration in the Systems Analysis Modelling Simulation copyright Taylor & Francis; Systems Analysis Modelling Simulation is available online at http://www.tandfonline.com/http://www.tandfonline.com/doi/abs/10.1080/0232929031000150337#.VFpIMWNNfH

    Probing the QCD vacuum with an abelian chromomagnetic field: A study within an effective model

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    We study the response of the QCD vacuum to an external abelian chromomagnetic field in the framework of a non local Nambu-Jona Lasinio model with the Polyakov loop. We use the Lattice results on the deconfinement temperature of the pure gauge theory to compute the same quantity in the presence of dynamical quarks. We find a linear relationship between the deconfinement temperature with quarks and the squared root of the applied field strength, gHgH, in qualitative (and to some extent also quantitative) agreement with existing Lattice calculations. On the other hand, we find a discrepancy on the approximate chiral symmetry restoration: while Lattice results suggest the deconfinement and the chiral restoration remain linked even at non-zero value of gHgH, our results are consistent with a scenario in which the two transitions are separated as gHgH is increased.Comment: 14 pages, 7 figures, RevTeX4. Published version, with enlarged abstract and minor changes in the main tex

    Vector interaction, charge neutrality and multiple chiral critical point structures

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    We investigate the combined effect of the repulsive vector interaction and the positive electric chemical potential on the chiral phase transition by considering neutral color superconductivity (CSC). The chiral condensate, diquark condensate and quark number densities are solved in both two-flavor and two-plus-one-flavor Nambu-Jona-Lasinio(NJL) models with the so called Kobayashi-Maskawa-'t Hooft term under the charge neutrality constraint. We demonstrate that multiple chiral critical-point structures always exist in the NJL model within the self-consistent mean-field approximation and the number of chiral critical points can vary from zero to four, which is dependent on the magnitudes of vector interaction and the diquark coupling. The difference between the dynamical chemical potentials induced by vector interaction for u and d quarks can effectively reduce the Fermi sphere disparity between the two flavors of diquark paring. Thus the vector interaction works to significantly suppress the unstable region associated with chromomagnetic instability in the phase of neutral asymmetric homogenous CSC.Comment: version for Phys. Rev.

    Nonlocality effects on Color Spin Locking condensates

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    We consider the color spin locking (CSL) phase of two-flavor quark matter at zero temperature for nonlocal instantaneous, separable interactions. We employ a Lorentzian-type form factor allowing a parametric interpolation between the sharp (Nambu-Jona-Lasinio (NJL) model) and very smooth (e.g. Gaussian) cut-off models for systematic studies of the influence on the CSL condensate the deviation from the NJL model entails. This smoothing of the NJL model form factor shows advantageous features for the phenomenology of compact stars: (i) a lowering of the critical chemical potential for the onset of the chiral phase transition as a prerequisite for stability of hybrid stars with extended quark matter cores and (ii) a reduction of the smallest pairing gap to the order of 100 keV, being in the range of values interesting for phenomenological studies of hybrid star cooling evolution.Comment: 8 pages, 8 figures, 1 table, accepted for publication in Phys.Rev.
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