Search results for "Electronics"
showing 10 items of 4340 documents
Standing up from a chair as a dynamic equilibrium task: a comparison between young and elderly subjects.
2000
The purpose of this study was to analyze and compare the features of center of mass (CoM) control along anterior/posterior axis in young and elderly subjects during sit-to-stand (STS). From a sitting position, seven healthy young subjects and seven healthy elderly subjects were asked to stand up from a chair under different experimental conditions (visual conditions: normal and blindfolded; speed: normal and as fast as possible). Analysis of results was based upon the concept of a “dynamic equilibrium area” (DEA), which in turn identified the dynamic limits of balance. The results showed that both the maximal CoM velocity in the horizontal axis and the CoM velocity at the instant of seat-of…
Biomechanical Determinants of Right Ventricular Failure in Pulmonary Hypertension.
2018
Pulmonary hypertension (PH) is a disease characterized by progressive adverse remodeling of the distal pulmonary arteries, resulting in elevated pulmonary vascular resistance and load pressure on the right ventricle (RV), ultimately leading to RV failure. Invasive hemodynamic testing is the gold standard for diagnosing PH and guiding patient therapy. We hypothesized that lumped-parameter and biventricular finite-element (FE) modeling may lead to noninvasive predictions of both PH-related hemodynamic and biomechanical parameters that induce PH. We created patient-specific biventricular FE models that characterize the biomechanical response of the heart and coupled them with a lumped-paramete…
Does anaerobic threshold correlate with maximal lactate steady-state?
1992
The aim of this study was to compare the 'anaerobic threshold' (AnT) of subjects determined during a continuous 2-min incremental exercise test until exhaustion and the 'maximal lactate steady-state' (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects' AnT and/or 5-25% above and below it. Seventeen subjects performed an incremental exercise test and 1-5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached …
Comparison of tactile sensitivity measured with a new digital esthesiometer (Beam Test) relative to Semmes–Weinstein monofilament analog esthesiometer
2019
The assessment of tactile sensitivity uses many tests, of which monofilaments are considered the best. The aim of this study was to develop a tactile sensitivity test, similar to the monofilament test, which eliminates the error risk related to manipulations by the observer, and to establish a correspondence scale. We studied 29 healthy subjects (18 women and 11 men) with a mean age of 27.8 years. The Semmes-Weinstein monofilament (SWM) analog esthesiometer and a digital beam esthesiometer (DBE) were used. We evaluated the tactile sensitivity threshold on the fingertip of each subject's dominant index using the SWM and the DBE. The DBE test consisted of applying the index against the tip of…
Diurnal coupling between testosterone and cortisol from adolescence to older adulthood
2016
The hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes are typically conceptualized as mutually inhibitory systems; however, previous studies have found evidence for positive within-person associations (i.e., coupling) between cortisol and testosterone. One developmental hypothesis is that positive testosterone-cortisol coupling is unique to the adolescent period and that coupling becomes attenuated, or even switches direction, in adulthood. This study used a lifespan sample (N = 292, ages 11 to 88) to test for age-related differences in coupling between cortisol and testosterone in daily life. Participants provided salivary hormone samples at waking, 30 minu…
Use of Visual Feedback During Jump-Squat Training Aids Improvement in Sport-Specific Tests in Athletes.
2020
Vanderka, M, Bezak, A, Longova, K, Krcmar, M, and Walker, S. Use of visual feedback during jump-squat training aids improvement in sport-specific tests in athletes. J Strength Cond Res 34(8): 2250-2257, 2020-This study investigated the effects of instantaneous performance feedback during the jump-squat exercise over a 6-week training period. Twenty-five strength-trained athletes were randomly divided into an instant feedback (n = 13, half-squat 3-repetition maximum (3RM)/body mass = 2.38 ± 0.19) or a nonfeedback (n = 12, half-squat 3RM/body mass = 2.03 ± 0.44) group. Both groups performed the same training program (3 × week), consisting of 4 sets of 8 repetitions (weeks 1-3) and 8 sets of 4…
Estimation of Muscular Fatigue under Electromyostimulation Using CWT
2012
International audience; The aims of this study are to investigate muscular fatigue and to propose a new fatigue index based on the continuous wavelet transform (CWT) which is compared to the standard fatigue indexes from literature. Fatigue indexes are all based on the electrical activity of muscles (electromyogram) acquired during an electrically stimulated contraction thanks to two modules (electromyostimulation + electromyography recording) that can analyze EMG signals in real time during electromyostimulation. The extracted parameters are compared with each other and their sensitivity to noise is studied. The effect of truncation of M waves is then investigated, enlightening the robustn…
Temporally stable beta sensorimotor oscillations and cortico–muscular coupling underlie force steadiness
2022
Funding Information: Data and code are available on the Open Science Framework (OSF) at the following link: https://osf.io/4rmex/?view_only=7d17c2334ace4a0d83087bddf2a64a68. Scott Mongold, Thomas Legrand, and Mathieu Bourguignon were supported by the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Brussels, Belgium; grant MIS F.4504.21). Harri Piitulainen was supported by the Academy of Finland (grants 266133, 296240, 326988, 327288 and 311877) including “Brain changes across the life-span” profiling funding to University of Jyväskylä. We thank Helge Kainulainen and Ronny Schreiber at Aalto NeuroImaging for providing technical help and the force sensor system for the study. We thank Riitta…
Prenatal exposure to lead in Spain: Cord blood levels and associated factors
2011
Abstract Introduction and Objective Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother–child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood). Methods A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blo…
Photobleaching effects onin vivoskin autofluorescence lifetime
2015
The autofluorescence lifetime of healthy human skin was measured using excitation provided by a picosecond diode laser operating at a wavelength of 405 nm and with fluorescence emission collected at 475 and 560 nm. In addition, spectral and temporal responses of healthy human skin and intradermal nevus in the spectral range 460 to 610 nm were studied before and after photobleaching. A decrease in the autofluorescences lifetimes changes was observed after photobleaching of human skin. A three-exponential model was used to fit the signals, and under this model, the most significant photoinduced changes were observed for the slowest lifetime component in healthy skin at the spectral range 520 …