298 research outputs found

    Strength and power throughout the menstrual cycle

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    2020 Spring.Includes bibliographical references.Purpose: The purpose was to determine if maximal muscle performance varies across the menstrual cycle because historically this measurement has been left out of research and women report feeling differences between phases. Strength and ballistic force production were measured in normally cycling eumenorrheic women and in women on hormonal birth control. We expected greater performance during the follicular vs. luteal phase because of fluctuating hormones, specifically estrogen, for the normally cycling women and more constant values for women on birth control because of the lack of fluctuating hormones due to effects of birth control. Methods: Participants were physically active women between 18-40 years who were either 1) eumenorrheic and not taking hormonal birth control (N=13), or 2) taking birth control (N=10). Ovulation was determined via body temperature and LH strips, and along with menses, was tracked for one full cycle prior to strength testing as well as during their two months of strength testing. Identical assessments were performed on four visits in the luteal and follicular phases over two consecutive months of menstrual cycles. Tests included leg and arm strength, ballistic force production, and vertical jump. Results: Comparisons were made between the luteal and follicular phases within subjects and between the normally cycling and hormonal birth control groups. No significant differences were found in for strength or ballistic functional measures between menstrual phases or between the groups (p=>0.05). Conclusions: Meaningful differences between phases would suggest that hormonal fluctuations affect muscle performance. We found no difference in muscle function between follicular and luteal phases. This suggests that the hormonal variation during the menstrual cycle is insufficient to alter maximal neuromuscular output. One possibility is that the relatively low number of participants hampered the ability to detect differences. If there are no differences between phases, the female athlete does not need to adjust their training and competition schedules

    Mapping the CMB I: the first flight of the QMAP experiment

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    We report on the first flight of the balloon-borne QMAP experiment. The experiment is designed to make a map of the cosmic microwave background anisotropy on angular scales from 0.7 to several degrees. Using the map we determine the angular power spectrum of the anisotropy in multipole bands from l~40 to l~140. The results are consistent with the Saskatoon (SK) measurements. The frequency spectral index (measured at low l) is consistent with that of CMB and inconsistent with either Galactic synchrotron or free-free emission. The instrument, measurement, analysis of the angular power spectrum, and possible systematic errors are discussed.Comment: 4 pages, with 5 figures included. Submitted to ApJL. Window functions and color figures are available at http://pupgg.princeton.edu/~cmb/welcome.htm

    Mapping the CMB II: the second flight of the QMAP experiment

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    We report the results from the second flight of QMAP, an experiment to map the cosmic microwave background near the North Celestial Pole. We present maps of the sky at 31 and 42 GHz as well as a measurement of the angular power spectrum covering the l-range 40-200. Anisotropy is detected at about 20 sigma and is in agreement with previous results at these angular scales. We also report details of the data reduction and analysis techniques which were used for both flights of QMAP.Comment: 4 pages, with 5 figures included. Submitted to ApJL. Window functions and color figures are available at http://pupgg.princeton.edu/~cmb/welcome.htm

    Galactic contamination in the QMAP experiment

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    We quantify the level of foreground contamination in the QMAP Cosmic Microwave Background (CMB) data with two objectives: (a) measuring the level to which the QMAP power spectrum measurements need to be corrected for foregrounds and (b) using this data set to further refine current foreground models. We cross-correlate the QMAP data with a variety of foreground templates. The 30 GHz Ka-band data is found to be significantly correlated with the Haslam 408 MHz and Reich and Reich 1420 MHz synchrotron maps, but not with the Diffuse Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps or the Wisconsin H-Alpha Mapper (WHAM) survey. The 40 GHz Q-band has no significant template correlations. We discuss the constraints that this places on synchrotron, free-free and dust emission. We also reanalyze the foreground-cleaned Ka-band data and find that the two band power measurements are lowered by 2.3% and 1.3%, respectively.Comment: 4 ApJL pages, including 4 figs. Color figures and data at http://www.hep.upenn.edu/~angelica/foreground.html#qmap or from [email protected]

    Eigenstate–Specific Temperatures in Two–Level Paramagnetic Spin Lattices

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    Increasing interest in the thermodynamics of small and/or isolated systems, in combination with recent observations of negative temperatures of atoms in ultracold optical lattices, has stimulated the need for estimating the conventional, canonical temperature Tconvc of systems in equilibrium with heat baths using eigenstate-specific temperatures (ESTs). Four distinct ESTs—continuous canonical, discrete canonical, continuous microcanonical, and discrete microcanonical—are accordingly derived for two-level paramagnetic spin lattices (PSLs) in external magnetic fields. At large N, the four ESTs are intensive, equal to Tconvc, and obey all four laws of thermodynamics. In contrast, for N \u3c 1000, the ESTs of most PSL eigenstates are non-intensive, differ from Tconvc, and violate each of the thermodynamic laws. Hence, in spite of their similarities to Tconvc at large N, the ESTs are not true thermodynamic temperatures. Even so, each of the ESTs manifests a unique functional dependence on energy which clearly specifies the magnitude and direction of their deviation from Tconvc; the ESTs are thus good temperature estimators for small PSLs. The thermodynamic uncertainty relation is obeyed only by the ESTs of small canonical PSLs; it is violated by large canonical PSLs and by microcanonical PSLs of any size. The ESTs of population-inverted eigenstates are negative (positive) when calculated using Boltzmann (Gibbs) entropies; the thermodynamic implications of these entropically induced differences in sign are discussed in light of adiabatic invariance of the entropies. Potential applications of the four ESTs to nanothermometers and to systems with long-range interactions are discussed

    Development and Validation of the Tele-Pulmonary Rehabilitation Acceptance Scale

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    BACKGROUND: Using telehealth in pulmonary rehabilitation (telerehabilitation) is a new field of health-care practice. To successfully implement a telerehabilitation program, measures of acceptance of this new type of program need to be assessed among potential users. The purpose of this study was to develop a scale to measure acceptance of using telerehabilitation by health-care practitioners and patients. METHODS: Three objectives were met (a) constructing a modified scale of the technology acceptance model, (b) judging the items for content validity, and (c) judging the scale for face validity. Nine experts agreed to participate and evaluate item relevance to theoretical definitions of domains. To establish face validity, 7 health-care practitioners and 5 patients were interviewed to provide feedback about the scale's clarity and ease of reading. RESULTS: The final items were divided into 2 scales that reflected the health-care practitioner and patient responses. Each scale included 3 subscales: perceived usefulness, perceived ease of use, and behavioral intention. CONCLUSIONS: The 2 scales, each with 3 subscales, exhibited evidence of content validity and face validity. The 17-item telerehabilitation acceptance scale for health-care practitioners and the 13-item telerehabilitation acceptance scale among patients warrant further psychometric testing as valuable measures for pulmonary rehabilitation programs

    Health Care Practitioners’ Determinants of Telerehabilitation Acceptance

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    Background: Pulmonary rehabilitation is a multidisciplinary patient-tailored intervention that aims to improve the physical and psychological condition of people with chronic respiratory diseases. Providing pulmonary rehabilitation (PR) services to the growing population of patients is challenging due to shortages in health care practitioners and pulmonary rehabilitation programs. Telerehabilitation has the potential to address this shortage in practitioners and PR programs as well as improve patients’ participation and adherence. This study’s purpose was to identify and evaluate the influences of intention of health care practitioners to use telerehabilitation. Methods: Data were collected through a self-administered Internet-based survey. Results: Surveys were completed by 222 health care practitioners working in pulmonary rehabilitation with 79% having a positive intention to use telerehabilitation. Specifically, perceived usefulness was a significant individual predictor of positive intentions to use telerehabilitation. Conclusion: Perceived usefulness may be an important factor associated with health care providers’ intent to use telerehabilitation for pulmonary rehabilitation

    Mesospheric Bore Evolution and Instability Dynamics Observed in PMC Turbo Imaging and Rayleigh Lidar Profiling over Northeastern Canada on 13 July 2018

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    Two successive mesospheric bores were observed over northeastern Canada on 13 July 2018 in high-resolution imaging and Rayleigh lidar profiling of polar mesospheric clouds (PMCs) performed aboard the PMC Turbo long-duration balloon experiment. Four wide field-of-view cameras spanning an area of ~75x150 km at PMC altitudes captured the two evolutions occurring over ~2 hr and resolved bore and associated instability features as small as ~100 m. The Rayleigh lidar provided PMC backscatter profiling that revealed vertical displacements, evolving brightness distributions, evidence of instability character and depths, and insights into bore formation, ducting, and dissipation. Both bores exhibited variable structure along their phases, suggesting variable gravity wave (GW) source and bore propagation conditions. Both bores also exhibited small-scale instability dynamics at their leading and trailing edges. Those at the leading edges comprised apparent Kelvin-Helmholtz instabilities that were advected downward and rearward beneath the bore descending phases extending into an apparently intensified shear layer. Instabilities at the trailing edges exhibited alignments approximately orthogonal to the bore phases that resembled those seen to accompany GW breaking or intrusions arising in high-resolution modeling of GW instability dynamics. Collectively, PMC Turbo bore imaging and lidar profiling enabled enhanced definition of bore dynamics relative to what has been possible by previous ground-based observations, and a potential to guide new, three-dimensional modeling of bore dynamics. The observed bore evolutions suggest potentially important roles for bores in the deposition of energy and momentum transported into the mesosphere and to higher altitudes by high-frequency GWs achieving large amplitudes

    First Results from COPSS: The CO Power Spectrum Survey

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    We present constraints on the abundance of carbon monoxide in the early universe from the CO Power Spectrum Survey. We utilize a data set collected between 2005 and 2008 using the Sunyaev–Zel'dovich Array (SZA), which was previously used to measure arcminute-scale fluctuations of the cosmic microwave background. This data set features observations of 44 fields, covering an effective area of 1.7 square degrees, over a frequency range of 27–35 GHz. Using the technique of intensity mapping, we are able to probe the CO(1–0) transition, with sensitivity to spatial modes between k = 0.5–2 h Mpc^(−1) over a range in redshift of z = 2.3–3.3, spanning a comoving volume of 3.6 × 10^6 h^(−3) Mpc^3. We demonstrate our ability to mitigate foregrounds, and present estimates of the impact of continuum sources on our measurement. We constrain the CO power spectrum to P_(CO) < 2.6 × 10^4 ÎŒK^2 (h^(−1) Mpc)^3, or Δ^2_(CO)(k = 1 h Mpc^(−1)) < 1.3 × 10^3 ÎŒK^2, at 95% confidence. This limit resides near optimistic predictions for the CO power spectrum. Under the assumption that CO emission is proportional to halo mass during bursts of active star formation, this corresponds to a limit on the ratio of CO(1–0) luminosity to host halo mass of A_(CO) < 1.2 × 10^(−5) L⊙_ M_⊙^(−1). Further assuming a Milky Way-like conversion factor between CO luminosity and molecular gas mass (α_(CO) = 4.3 M_⊙ (K km s^(−1) pc^(−2))^(−1)), we constrain the global density of molecular gas to ρ_(z~3) (M_H_2) â©œ 2.8 x 10^8 M_☉ Mpc^(-3)
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