A Comparison of Blood Viscosity and Hematocrit Levels between Yoga Practitioners and Sedentary Adults

International Journal of Exercise Science 12(2): 425-432, 2019. Elevations in whole blood viscosity (WBV) and hematocrit (Hct), have been linked with increased risk of cardiovascular disease (CVD). Endurance training has been demonstrated to lower WBV and Hct; however, evidence supporting the efficacy of yoga on these measures is sparse. A cross-sectional study was conducted examining WBV and Hct levels between yoga practitioners with a minimum of 3 years of consistent practice and sedentary, healthy adults. Blood samples were collected from a total of 42 participants: 23 sedentary adults and 19 regular yoga practitioners. Brachial arterial blood pressure (BP) was measured and the averages of 3 measures were reported. The yoga practitioner group had significantly lower WBV at 45 s-1 (p \u3c 0.01), 90 s-1 (p \u3c 0.01), 220 s-1 (p \u3c 0.05), and 450 s-1 (p \u3c 0.05) than sedentary participants. No significant group differences in Hct (p =0.38) were found. A tendency toward lower systolic BP (p=0.06) was observed in the yoga practitioner group; however, no significant group differences in BP were exhibited. A consistent yoga practice was associated with lower WBV, a health indicator related to CVD risk. These findings support a regular yoga practice as a valid form of exercise for improving rheological indicators of cardiovascular health

A Comparison of Blood Viscosity, Hematocrit and Blood Pressure between Yoga Practitioners and Sedentary Individuals

Elevations in whole blood viscosity (WBV) and hematocrit (Hct) have been linked with increased risk of cardiovascular disease (CVD) and coexist with elevations in systolic blood pressure (SBP). Endurance training has been demonstrated to lower WBV and Hct; however, evidence supporting the efficacy of yoga on these measures is sparse. METHODS: A cross-sectional study was conducted examining WBV, Hct and blood pressure among yoga practitioners with a minimum of 3 months of consistent practice and sedentary, healthy adults. Blood samples were collected from a total of 42 participants: 23 sedentary adults and 19 regular yoga practitioners. Brachial arterial blood pressure (BP) was measured and the averages of 3 measures were reported. RESULTS: Yoga practitioners had significantly lower WBV at 45 s-1 (p \u3c 0.01), 90 s-1 (p \u3c 0.01), 220 s-1 (p \u3c 0.05), and 450 s-1 (p \u3c 0.01) than sedentary participants. No significant group differences in Hct (p =0.38) were found. A tendency toward lower systolic BP (p=0.06) was observed in the yoga practitioner group; however, no significant group differences in BP were exhibited. CONCLUSION: A consistent yoga practice was associated with lower WBV and a trend of lower SBP, health indicators associated with CVD risk. These findings support a regular yoga practice as a valid form of exercise for improving rheological indicators of cardiovascular health

Acute Effects of Vinyasa Flow Yoga on Lipid Profile and Fasting Glucose

Dyslipidemia and hyperglycemia are modifiable risk factors for cardiovascular disease (CVD) which could be impacted by yoga. Short- and long-term interventional trials have demonstrated the efficacies of various styles of hatha yoga in improving both lipid profile and fasting glucose concentrations; however, the acute effects of hatha yoga on these measures are unknown. Vinyasa flow yoga is a style of hatha yoga characterized by continuous movement, smooth transitioning between postures, and a synchronization of breath and posture transitions. To date, it is unknown whether this style of yoga can alter lipid profile or glucose concentrations. PURPOSE: The purpose of this study was to evaluate the acute effects of a Vinyasa yoga session on lipid profile and fasting glucose concentrations in yoga practitioners with a minimum of 3 months of yoga practice experience. METHODS: Eighteen yoga practitioners (20 – 75) completed one 60-minute Vinyasa yoga DVD. Whole blood samples were obtained (after 8 hrs of fasting) and analyzed for total- and HDL-cholesterol, triglyceride, and glucose concentrations via reflectance photometry. Briefly, 35µL blood samples were applied to test cassette sampling wells and color changes of the reagent pads were converted to concentration values. LDL-cholesterol was calculated using the Friedewalde equation. RESULTS: After completion of the Vinyasa flow yoga session, no changes occurred in glucose (p = 0.398) or total- (p=0.344), HDL- (p = 0.806), or LDL-cholesterol (p=0.685). Triglyceride concentrations also remained the same after the session (p = 0.462). CONCLUSION: These preliminary results suggest that engaging in vinyasa flow yoga for 1 hour does not induce beneficial changes in lipid profile and glucose concentrations. Further research is needed to determine the potential efficacy of yoga, an alternative exercise mode, in producing favorable changes in lipid profile, glucose and overall CVD risk profile. This study was funded in part by Pure Action, Inc. Austin, TX, USA

The Effects of Slow Deep Breathing on Measures of Microvascular and Autonomic Function in an Irritable Bowel Syndrome Population

Irritable Bowel Syndrome (IBS) is a functional disorder linked to disruptions in autonomic nervous system regulation, which could impair vascular homeostasis. Studies have shown that slow, deep breathing reduces muscle sympathetic nerve activity and arterial stiffness; however, its effects on autonomic regulation in adults with IBS have not been previously investigated. Moreover, the effects of breathing on microvascular endothelium function are unknown. PURPOSE: To investigate the effects of slow, deep breathing on measures of autonomic function and microvascular endothelial function in adults with IBS. METHODS: Adults (ages 18-65 years) with a formal diagnosis of IBS were enrolled and randomized to 4-week controlled breathing or time-control conditions. The experimental group followed a 20-minute slow, deep breathing video 4 to 6 days per week while the control group maintained their regular activity. To assess autonomic function, heart rate variability (HRV) and exercise heart rate recovery (HRR) were measured at baseline and week 4. The HRV test was accompanied by respiration rate measurements to ensure no significant deviations in respiration occurred between assessments as this could impact HRV. Exercise HRR was assessed 30, 60, and 120 seconds following a Balke treadmill VO2 max test. Laser Doppler flowmetry was assessed at baseline (33°C) and in response to local heating up to 43.5°C while blood pressure was measured throughout for the calculation of cutaneous vascular conductance (CVC). RESULTS: Of the 14 participants enrolled, 12 (n=6 for control and experimental groups) completed the study. At baseline, age (p = 0.47) and body mass index (p=0.14) were similar between groups. Respiration rate was similar between HRV assessments in both groups. In the experimental group, %CVC max significantly increased (p = 0.027) at week 4 while HRR was unchanged. A tendency toward a time by group interaction was observed for HRV low frequency to high frequency (LF/HF) ratio (p = 0.066) with slight reductions in the breathing group and increases in the control group. In the control group, %CVC max and HRR were unaltered, though HRR at 120 seconds tended to improve (p=0.08). CONCLUSIONS: Preliminary results from this ongoing study suggest that microvascular endothelial function can improve with 4 weeks of slow, deep breathing exercises in adults with IBS. These alterations in vascular function were unaccompanied by significant changes in autonomic function though trends were observed in HRV. Results show that slow, deep breathing is a viable alternative to physical exercise for improving microvascular function. Findings also suggest that this intervention could result in improved sympathovagal balance in adults with IBS and potentially other individuals with functional disorders

EGRET Observations of the Extragalactic Gamma Ray Emission

The all-sky survey in high-energy gamma rays (E$>$30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray emission. The observed diffuse emission has a Galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation as well an almost uniformly distributed component that is generally believed to originate outside the Galaxy. Through a careful study and removal of the Galactic diffuse emission, the flux, spectrum and uniformity of the extragalactic emission is deduced. The analysis indicates that the extragalactic emission is well described by a power law photon spectrum with an index of -(2.10+-0.03) in the 30 MeV to 100 GeV energy range. No large scale spatial anisotropy or changes in the energy spectrum are observed in the deduced extragalactic emission. The most likely explanation for the origin of this extragalactic high-energy gamma-ray emission is that it arises primarily from unresolved gamma-ray-emitting blazars.Comment: 19 pages latex, 10 figures, accepted for publication in Ap

MEGA: A Medium-Energy Gamma-ray Astronomy mission concept

The Medium Energy Gamma-ray Astronomy (MEGA) telescope concept will soon be proposed as a MIDEX mission. This mission would enable a sensitive all-sky survey of the medium-energy gamma-ray sky (0.4 - 50 MeV) and bridge the huge sensitivity gap between the COMPTEL and OSSE experiments on the Compton Gamma Ray Observatory, the SPI and IBIS instruments on INTEGRAL, and the visionary Advanced Compton Telescope (ACT) mission. The scientific goals include, among other things, compiling a much larger catalog of sources in this energy range, performing far deeper searches for supernovae, better measuring the galactic continuum and line emissions, and identifying the components of the cosmic diffuse gamma-ray emission. MEGA will accomplish these goals using a tracker made of Si strip detector (SSD) planes surrounded by a dense high-Z calorimeter. At lower photon energies (below ∼ 30 MeV), the design is sensitive to Compton interactions, with the SSD system serving as a scattering medium that also detects and measures the Compton recoil energy deposit. If the energy of the recoil electron is sufficiently high (\u3e 2 MeV) its momentum vector can also be measured. At higher photon energies (above ∼10 MeV), the design is sensitive to pair production events, with the SSD system measuring the tracks of the electron and positron. A prototype instrument has been developed and calibrated in the laboratory and at a gamma-ray beam facility. We present calibration results from the prototype and describe the proposed satellite mission

The First Stars

The first stars to form in the Universe -- the so-called Population III stars -- bring an end to the cosmological Dark Ages, and exert an important influence on the formation of subsequent generations of stars and on the assembly of the first galaxies. Developing an understanding of how and when the first Population III stars formed and what their properties were is an important goal of modern astrophysical research. In this review, I discuss our current understanding of the physical processes involved in the formation of Population III stars. I show how we can identify the mass scale of the first dark matter halos to host Population III star formation, and discuss how gas undergoes gravitational collapse within these halos, eventually reaching protostellar densities. I highlight some of the most important physical processes occurring during this collapse, and indicate the areas where our current understanding remains incomplete. Finally, I discuss in some detail the behaviour of the gas after the formation of the first Population III protostar. I discuss both the conventional picture, where the gas does not undergo further fragmentation and the final stellar mass is set by the interplay between protostellar accretion and protostellar feedback, and also the recently advanced picture in which the gas does fragment and where dynamical interactions between fragments have an important influence on the final distribution of stellar masses.Comment: 72 pages, 4 figures. Book chapter to appear in "The First Galaxies - Theoretical Predictions and Observational Clues", 2012 by Springer, eds. V. Bromm, B. Mobasher, T. Wiklin

Cross-cutting principles for planetary health education

Since the 2015 launch of the Rockefeller Foundation Lancet Commission on planetary health,1 an enormous groundswell of interest in planetary health education has emerged across many disciplines, institutions, and geographical regions. Advancing these global efforts in planetary health education will equip the next generation of scholars to address crucial questions in this emerging field and support the development of a community of practice. To provide a foundation for the growing interest and efforts in this field, the Planetary Health Alliance has facilitated the first attempt to create a set of principles for planetary health education that intersect education at all levels, across all scales, and in all regions of the world—ie, a set of cross-cutting principles