Search results for "imulation"
showing 10 items of 7271 documents
Entropy of balance--some recent results.
2010
Abstract Background Entropy when applied to biological signals is expected to reflect the state of the biological system. However the physiological interpretation of the entropy is not always straightforward. When should high entropy be interpreted as a healthy sign, and when as marker of deteriorating health? We address this question for the particular case of human standing balance and the Center of Pressure data. Methods We have measured and analyzed balance data of 136 participants (young, n = 45; elderly, n = 91) comprising in all 1085 trials, and calculated the Sample Entropy (SampEn) for medio-lateral (M/L) and anterior-posterior (A/P) Center of Pressure (COP) together with the Hurst…
Preoperative simulation of postoperative iris-fixated phakic intraocular lens position and simulation of aging using high-resolution Scheimpflug imag…
2006
To increase postoperative safety after implantation of iris-fixated phakic intraocular lenses (pIOLs), optimal preoperative evaluation and patient selection is mandatory. We present a new software tool in a high-resolution Scheimpflug imaging device that precisely simulates the postoperative position of an iris-fixated pIOL and also simulates the effect of aging on the pIOL's position.
β-Adrenoceptor stimulation up-regulates phosphodiesterase 4 activity and reduces prostaglandin E 2 -inhibitory effects in human neutrophils
2000
Human neutrophils were treated for 4 h with a combination of salbutamol (1 µM), a β2-adrenoceptor agonist, and rolipram (30 µM), a selective phosphodiesterase 4 inhibitor, to investigate whether this treatment produces up-regulation of phosphodiesterase activity with functional consequences. Anion-exchange chromatography coupled with the use of selective activators and inhibitors demonstrated that a phosphodiesterase activity with characteristics of the isoenzyme type 4 was increased in drug-treated cells. Kinetic analysis showed a ~1.5-fold increase in V max without alteration of K m values. The augmented phosphodiesterase activity in drug-treated cells was abolished by actinomycin D. Cycl…
δ 1‐OPIOID receptor‐mediated controlofacetylcholine (ACh) release in human neocortex slices
1998
In slices of human neocortex, prelabelled with [3H]-choline, the release of [3H]-acetylcholine reflects the evoked release of endogenous acetylcholine which was elicited by the same electrical stimulation paradigm. [3H]-Acetylcholine release was depressed by the delta-opioid receptor agonist D-Pen2-D-Pen5-enkephalin. When the nerve endings were depolarized by elevating extracellular potassium the evoked [3H]-acetylcholine release was similarly depressed by D-Pen2-D-Pen5-enkephalin in the absence, but not in the presence, of tetrodotoxin which blocks action potential propagation. Therefore, the delta-opioid receptor inhibiting [3H]-acetylcholine release should not be located to cholinergic n…
Cutaneous lymphocyte antigen expression on human effector B cells depends on the site and on the nature of antigen encounter
2003
In contrast to T cells, information on skin-homing B cells expressing the cutaneous lymphocyte antigen (CLA) is sparse. CLA expression on human B cells was investigated among circulating immunoglobulin-secreting cells (ISC) and among antigen-specific antibody-secreting cells (ASC) elicited by parenteral, oral or rectal primary immunization, or by parenteral or oral secondary immunization with Salmonella typhi Ty21a. CLA expression was examined by combining cell sorting with an enzyme-linked immunospot assay. Among all ISC, the proportion of CLA(+) cells was 13-21%. Parenteral immunization induced antigen-specific ASC of which 13% were CLA(+), while oral and rectal immunizations were followe…
Amusic does not mean unmusical: Beat perception and synchronization ability despite pitch deafness
2013
Pitch deafness, the most commonly known form of congenital amusia, refers to a severe deficit in musical pitch processing (i.e., melody discrimination and recognition) that can leave time processing--including rhythm, metre, and "feeling the beat"--preserved. In Experiment 1, we show that by presenting musical excerpts in nonpitched drum timbres, rather than pitched piano tones, amusics show normal metre recognition. Experiment 2 reveals that body movement influences amusics' interpretation of the beat of an ambiguous drum rhythm. Experiment 3 and a subsequent exploratory study show an ability to synchronize movement to the beat of popular dance music and potential for improvement when give…
Increased migraine-free intervals with multifocal repetitive transcranial magnetic stimulation.
2021
Introduction: Episodic migraine is a debilitating condition associated with vast impairments of health, daily living, and life quality. Several prophylactic treatments exist, having a moderate ratio of action related to side effects and therapy costs. Repetitive transcranial magnetic stimulation (rTMS) is an evidence based therapy in several neuropsychiatric conditions, showing robust efficacy in alleviating specific symptoms. However, its efficacy in migraine disorders is unequivocal and might be tightly linked to the applied rTMS protocol. We hypothesized that multifocal rTMS paradigm could improve clinical outcomes in patients with episodic migraine by reducing the number of migraine day…
Motion-Cuing Algorithms
2015
Objective:The aim of this study was to characterize the human response to motion-cuing algorithms (MCAs) by comparing users’ perception to several proposed objective indicators.Background:Other researchers have proposed several MCAs, but few improvements have been achieved lately. One of the reasons for this lack of progress is that fair comparisons between different algorithms are hard to achieve, for their evaluation needs to be performed with humans and the tuning process is slow.Method:This characterization is performed by means of a comparison of the subjective perception of vehicle simulation users (90 participants) against several proposed objective indicators that try to measure MCA…
The pancreatic beta-cell response to intravenous administration of glucose in elderly subjects.
1970
A study was made of the serum insulin level after the intravenous administration of glucose (0.33 gm/ kg) in two groups of normal subjects—18 in the 60–85 age bracket, and 16 in the 23–45 age bracket. All had a normal coefficient of glucose utilization and a normal blood glucose curve after intravenous administration of glucose. Serum insulin was assayed by the radio-immunological method, with use of an ion exchange resin. Blood samples were drawn at 2, 5, 10, 30, 45 and 60 minutes after the end of the glucose infusion. In the elderly subjects the maximal value was reached only after 5 minutes and the mean value was 39± 9 µU/ml (range, 27–50), whereas in the younger subjects the serum insul…
Effect of neuromuscular electrical stimulation frequency on postprandial glycemia, current-related discomfort, and muscle soreness. A crossover study
2019
Consensus is lacking regarding optimal neuromuscular electrical stimulation (NMES) parameters for postprandial glycemic control. Therefore, the aim of this study was to determine the NMES frequency inducing the greatest hypoglycemic effect in healthy individuals. The secondary aim was to compare current-related discomfort and muscle soreness between different frequencies. We conducted an experimental clinical study with a randomized crossover design. Sixteen healthy and sedentary participants received NMES for 20 min at 5, 10, or 50 Hz (pulse duration: 400 μs, on-off ratio: 4:12 s) following a standardized meal. Glycemia, discomfort, and muscle soreness during and after NMES were compared …