Concordance Among Bioelectrical Impedance Analysis Measures Of Percent Body Fat In Athletic Young Adults

International Journal of Exercise Science 12(4): 324-331, 2019. The purpose of this investigation was to determine the agreement among three bioelectrical impedance analysis devices (BIA) in athletic young adults. Fifty-one participants (26 men and 25 women) were assessed for percent body fat (PBF) using an arm-to-arm bipolar single-frequency device (ABIA), a leg-to-leg single-frequency device (LBIA), and an octopolar multi-frequency BIA device (MFBIA). PBF was measured with the three devices in a randomized, counterbalanced order. Repeated measures ANOVA revealed significant (p \u3c 0.001) differences in PBF estimates among all devices (ABIA = 19.1 ± 7.2%, LBIA = 21.6 ±7.5%, and MFBIA = 22.9 ± 8.8%). Pearson’s Correlations revealed a strong relationship between ABIA and MFBIA in both men (r = 0.948) and women (r = 0.947) and a moderately-strong relationship between LBIA and MFBIA (r = 0.870 and 0.679, respectively). Lin’s concordance coefficient revealed moderately-strong concordance between ABIA and MFBIA in men (ρc= 0.800) and women (ρc= 0.681) and between LBIA and MFBIA (ρc = 0.846 and ρc= 0.651, respectively). These data indicate a strong agreement among all three devices, suggesting that any of them could be used to track changes in PBF over time. However, the significant differences in PBF values among devices imply that best practice for monitoring body composition should be to use one device consistently over time for a reliable assessment

Comparison Of Knee Moments And Landing Patterns During A Lateral Cutting Maneuver: Shod Vs. Barefoot

Non-contact anterior cruciate ligament (ACL) injuries often occur during lateral cutting maneuvers where extension, adduction, and external rotation create high loads on the ACL. The aim of this study was to examine knee moments and foot strike patterns during lateral cutting while shod (SD) and barefoot (BF). Fifteen NCAA Division III athletes (7 female and 8 male; age 20.2 ± 1.5 yr; mass 71.5 ± 11.3 kg; height, 1.7 ± .06 m) without lower limb pathologies were analyzed during 5 trials of 45 degree lateral cutting maneuvers for each limb in both BF and SD conditions with the approach speed at 4.3 m/s. Kinetic and kinematic data were collected using an eight-camera motion capture system and a force plate with collection rates at 240 Hz and 2400Hz respectively. Paired t-tests were used to determine differences conditions. The SD condition produced a significantly (p\u3c0.05) greater peak adduction moment and cutting while BF caused a more anterior foot strike. Lateral cutting while BF places no more stress on the ACL than when SD. Our findings suggest that lateral cutting maneuvers while BF will not increase stress on the ACL

Influence of magnetic field inhomogeneity on a magneto-optical current sensor

The growth in the capacity of electric power system creates a demand for the protection of relaying systems. Optical current transducers—OCT that are mainly made up of single mode optical fibers which are subjected to Faraday rotation are used as a replacement for electromagnetic transducers due to their immunity to electromagnetic interference. However, the principal parameter in this system, the sensitivity to magnetic fields or current, depends on the Verdet constant, which is low in the case of optical fibers. However, the optical path length can be increased to compensate for it by winding the fiber around a current carrying element a large number of turns. In this work, we study a current sensor, which is made up of a conductor coil with a fiber inside, thus increasing sensitivity. We study the effect of the inhomogeneity of the magnetic field induced by the current on the sensitivity of the optical fiber sensor

Analytical solution of four-mode coupling in shear strain loaded fiber Bragg grating sensors

The polarization-dependant reflection spectra of fiber Bragg grating (FBG) sensors in polarization-maintaining fibers are influenced by shear strain. This influence can be evaluated from a tensorial coupled-mode theory approach. Yet, this approach requires the numerical integration of the four coupled-mode equations. We present an easy to handle, completely analytical treatment of the polarization-dependent reflection spectra of FBGs. We derive the required equations and compare the results to the numerical integration of the four tensorial coupled mode equations

Measurement errors from internal shear strain within fiber-Bragg-grating sensors

Fiber-Bragg-grating (FBG) sensors have become commercially available sensors for the measurement of temperature, strain and many other quantities. The sensor information is encoded in the spectral reflection characteristic of these devices. Their usage as strain sensors is one of the most prominent fields of application. Strains from a structure which is to be monitored are transferred into the fiber-Bragg-grating, by surface bonding or embedding. In general an arbitrary state of strain may thus occur within the FBG, represented by a full strain tensor with normal strain components, as well as with shear strain components. The influence of normal strains is well understood and has been treated theoretically by many authors. The influence of shear strains is however not well understood. As we were recently able to theoretically demonstrate by a full tensor coupled mode analysis, shear strains do influence the spectral

Phosphocholine-Modified Lipooligosaccharides of Haemophilus influenzae Inhibit ATP-Induced IL-1beta Release by Pulmonary Epithelial Cells

Phosphocholine-modified bacterial cell wall components are virulence factors enabling immune evasion and permanent colonization of the mammalian host, by mechanisms that are poorly understood. Recently, we demonstrated that free phosphocholine (PC) and PC-modified lipooligosaccharides (PC-LOS) from Haemophilus influenzae, an opportunistic pathogen of the upper and lower airways, function as unconventional nicotinic agonists and efficiently inhibit the ATP-induced release of monocytic IL-1beta. We hypothesize that H. influenzae PC-LOS exert similar effects on pulmonary epithelial cells and on the complex lung tissue. The human lung carcinoma-derived epithelial cell lines A549 and Calu-3 were primed with lipopolysaccharide from Escherichia coli followed by stimulation with ATP in the presence or absence of PC or PC-LOS or LOS devoid of PC. The involvement of nicotinic acetylcholine receptors was tested using specific antagonists. We demonstrate that PC and PC-LOS efficiently inhibit ATP-mediated IL-1beta release by A549 and Calu-3 cells via nicotinic acetylcholine receptors containing subunits alpha7, alpha9, and/or alpha10. Primed precision-cut lung slices behaved similarly. We conclude that H. influenzae hijacked an endogenous anti-inflammatory cholinergic control mechanism of the lung to evade innate immune responses of the host. These findings may pave the way towards a host-centered antibiotic treatment of chronic airway infections with H. influenzae

Shear strain influence on fiber Bragg grating measurement systems

Fiber Bragg grating (FBG) sensors have become commercially available sensors for the measurement of temperature, strain, and many other quantities. One interesting application is the embedding of these sensors, during which shear strains can arise inside the sensor. As we have recently demonstrated by a full-tensor coupled-mode analysis, shear strains do influence the spectral response of fiber Bragg sensors, and thus have to be considered. In this paper, we use the theory behind this analysis to compute the direct influence of shear strains on the output of a FBG measurement system, and show cases where shear strain effects are relevant. Furthermore, we compare the sensitivity of different interrogation algorithms toward shear strain influences on the measurement system output. To model the experimentally relevant unpolarized light

Resistance exercise load reduction and exercise-induced micro-damage

High volumes of resistance exercise increase muscle hypertrophy, independent of the extent of muscle damage. We compared volume load and markers of muscle damage after resistance exercise using two load reduction strategies versus a constant intensity. Methods: Twenty-seven trained men (age = 23.4±3.5 years, body mass = 74.5±10.7 Kg, height = 174±8 cm, 10 RM = 211±40 Kg) completed one weekly bout of 4 sets of leg press exercise under three loading schemes in a randomized, counterbalanced order over a three-week period. The loading schemes were (a) constant load for all sets (CON), (b) 5% load reduction after each set (LR5), and (c) 10% load reduction after each set (LR10). Volume load, muscle soreness (SOR), and range of motion (ROM) at the knee were assessed after each bout. Results: Volume load was significantly different amongst all conditions (CON = 6799±1583 Kg; LR5 = 8753±1789 Kg; 10896±2262 Kg; F=31,731; p<0.001). ROM and SOR were significantly different among conditions, with LR5 and LR10 producing greater preservations of ROM (p =<0.001) and less SOR (p < 0.001). These data may support the use of load reductions when training for hypertrophy

Is hypertension associated with a greater increase in creatine kinase activity following cycling exercise? A case study

We describe discrepant behavior of serum creatine kinase (CK) activity during and after cycling in a hypertensive athlete when compared to the healthy athletes from the same team of endurance cyclists. Heart Rate (HR), Blood Pressure (BP), Perceived Exertion (PE) and serum CK activity were evaluated before, during and after 150 km indoor cycling. The results showed that there were no differences between the hypertensive athlete and the healthy athletes in time trial (186.3 min vs. 179.1 ± 14.9 min), HR (159.3 ± 11.4 bpm vs. 169.5 ± 7.8 bpm respectively) and PE (6.3 ± 1.5 vs. 6.3 ± 1.3). Systolic BP was higher in hypertensive athlete before, during and after the exercise. Serum CK activity was higher (+47%) at baseline and exhibited a higher increase (&gt; +200%) after exercise. Our finding shed light on a hypothesis regarding the interindividual variability of serum CK activity and its possible interaction with hypertension

Caffeine Does Not Augment Markers of Muscle Damage or Leukocytosis Following Resistance Exercise

The purpose of this study was to evaluate the effects of caffeine ingestion before a resistance exercise session on markers of muscle damage (CK, LDH, ALT, AST) and leukocyte levels. Methods: Fifteen soccer athletes completed two resistance exercise sessions that differed only in the ingestion of caffeine or a placebo preworkout. Results: CK concentration increased significantly following the caffeine session (415.8 ± 62.8 to 542.0 ± 73.5) and the placebo session (411.5 ± 43.3 to 545.8 ± 59.9), with no significant differences between sessions. Similarly, LDH concentration increased significantly following the caffeine session (377.5 ± 18.0 to 580.5 ± 36.1) and the placebo session (384.8 ± 13.9 to 570.4 ± 36.1), with no significant differences between sessions. Both sessions resulted in significant increases in the total leukocyte count (caffeine = 6.24 ± 2.08 to 8.84 ± 3.41; placebo = 6.36 ± 2.34 to 8.77 ± 3.20), neutrophils (caffeine = 3.37 ± 0.13 to 5.15 ± 0.28; placebo = 3.46 ± 0.17 to 5.12 ± 0.24), lymphocytes (caffeine = 2.19 ± 0.091 to 2.78 ± 0.10; placebo = 2.17 ± 0.100 to 2.75 ± 0.11), and monocytes (caffeine = 0.53 ± 0.02 to 0.72 ± 0.06; placebo = 0.56 ± 0.03 to 0.69 ± 0.04), with no significant differences between sessions. Conclusion: Ingestion of caffeine at 4.5 mg⋅kg−1 did not augment markers of muscle damage or leukocyte levels above that which occurs through resistance exercise alone