Search results for "FAST"
showing 10 items of 821 documents
Cellular-free magnesium depletion in brain and muscle of normal and preeclamptic pregnancy: A nuclear magnetic resonance spectroscopic study
2004
Preeclampsia is a pregnancy disorder of unknown origin, characterized by vasospasm, elevated blood pressure, and increased neuromuscular irritability, features common to syndromes of magnesium deficiency. Evidence of serum and ionized magnesium metabolism disturbances have been observed in women with preeclampsia. This and the therapeutic utility of magnesium in preeclampsia led us to investigate the extent to which an endogenous tissue magnesium deficiency might be present in and contribute to its pathophysiology. We used 31 P nuclear magnetic resonance spectroscopy to noninvasively measure in situ intracellular-free magnesium levels in brain and skeletal muscle of fasting nonpregnant wom…
The relative contribution to the plantar-flexor torque of the soleus motor units activated by the H reflex and M response in humans.
2000
Abstract This study proposes a method of quantifying the relative contribution to the plantar-flexor torque of soleus H and M responses evoked by tibial nerve stimulation. For ten subjects, the amplitude of the twitch produced by the H wave was plotted against the corresponding potential, for stimuli producing H without M (i.e. in the ascending portion of the H-recruitment curve). It was then assumed that the contribution of H to twitches produced by M plus H was similar for similar H waves on the curve-descending portion. Hence, the contribution of M was estimated, for the range of M waves including those accompanying H max . The estimated mechanical contributions of H and M wave increase …
Selecting one of two regular sound sequences : Perceptual and motor effects of tempo
2008
This study assessed the influence of tempo on selecting a sound sequence. In Exp. 1, synchronization with one of the two regular subsequences in a complex sequence was measured. 30 participants indicated a preference for the fastest subsequence when subsequences were in a slow tempo range (≥ 500 msec. IOI), and with the slower subsequence when they were in the fast tempo range (≤ 300 msec. IOI). These results were replicated using a perceptual task (Exp. 2 and 3) in which the 30 listeners had to detect a temporal irregularity in one of the two subsequences. Detection was better when the temporal irregularity was in the fastest subsequence than in the slowest one when the complex sequence w…
Impaired plasma nitric oxide availability and extracellular superoxide dismutase activity in healthy humans with advancing age
2006
This study is aimed to verify the modifications of extracellular superoxide dismutase (EC-SOD) activity and its potential involvement on the mechanism responsible for the impairment of plasma nitric oxide (NO) availability occurring with advancing age in healthy humans. For this purpose, plasma samples were drawn from 40 healthy men, aged 20-92 years, in fasting state and used for measurements of stable end-product nitrite/nitrate (NOx), as expression of NO availability, EC-SOD activity, thiobarbituric acid reactive substances (TBARS) as marker of lipid peroxidation, Trolox equivalent antioxidant capacity (TEAC) as a measure of plasma total antioxidant capacity, and in vitro susceptibility …
Changes in cerebellar activation pattern during two successive sequences of saccades
2002
The changes in the cerebellar activation pattern of two successive fMRI scanning runs were determined for visually guided to‐and‐fro saccades in 12 healthy volunteers familiar with the study paradigm. Group and single subject‐analyses revealed a constant activation of the paramedian cerebellar vermis (uvula, tonsils, tuber, folium/declive), which reflects constant ocular motor activity in both runs. A significant decrease in activation of the cerebellar hemispheres found in the second run is best explained by either a decrease in attention or the effects of motor optimization and learning. The significant, systematic changes of the cerebellar activation pattern in two successive runs were n…
Time and frequency analysis of the static balance in young adults with Down syndrome
2010
The main objective of this study is to understand the differences in equilibrium control between normal subjects and those with Down syndrome. A total of 54 subjects participated voluntarily, divided into control group and Down syndrome group. The equilibrium of the subjects was tested under two conditions: bipedal support with eyes open and closed. The signals were analyzed in a time and frequency domain. The statistical parameters selected (i.e., RMS distance, mean velocity, mean frequency and sway area) to analyze the behavior of the center of pressures (CoP) are calculated employing the result of the combination of the time series data in both directions (i.e. resultant distance). In or…
Pleasant music as a countermeasure against visually induced motion sickness.
2013
Visually induced motion sickness (VIMS) is a well-known side-effect in virtual environments or simulators. However, effective behavioral countermeasures against VIMS are still sparse. In this study, we tested whether music can reduce the severity of VIMS. Ninety-three volunteers were immersed in an approximately 14-minute-long video taken during a bicycle ride. Participants were randomly assigned to one of four experimental groups, either including relaxing music, neutral music, stressful music, or no music. Sickness scores were collected using the Fast Motion Sickness Scale and the Simulator Sickness Questionnaire. Results showed an overall trend for relaxing music to reduce the severity o…
Mechanical characteristics and fiber composition of human leg extensor muscles.
1979
To investigate the influence of skeletal muscle fiber composition on the mechanical performance of human skeletal muscle under dynamic conditions, 34 physical education students with differing muscle fiber composition (M. vastus lateralis) were used as subjects to perform maximal vertical jumps on the force-platform. Two kinds of jumps were performed: one from a static starting position (SJ), the other with a preliminary counter-movement (CMJ). The calculated mechanical parameters included height of rise of center of gravity (h), average force (F), net impulse (NI) and average mechanical power (W). It was observed that the percentage of fast twitch fibers was significantly related (p less t…
Identification of a Unique Helicobacter Species by 16S rRNA Gene Analysis in an Abdominal Abscess from a Patient with X-Linked Hypogammaglobulinemia
2000
ABSTRACT A unique Helicobacter species, MZ640285, was isolated from a patient with X-linked hypogammaglobulinemia suffering from recurrent abdominal abscesses and was identified by 16S rRNA gene sequence analysis. In the phylogenetic tree, the isolate fell into a cluster which included Flexispira rappini , Helicobacter bilis , and Helicobacter sp. strain Mainz. Helicobacters are being increasingly recognized as pathogens in immunocompromised hosts. These fastidious bacteria are not easily cultured in the routine diagnostic laboratory, and this is the first report of their identification by 16S rRNA gene sequencing performed directly from a clinical specimen.
Bilateral and Unilateral Neuromuscular Function and Muscle Cross-Sectional Area in Middle-Aged and Elderly Men and Women
1996
Forty-eight healthy men (M) and women (W), divided into two different age groups, i.e., M50 yrs (range 44-57; n = 12), W50 yrs (range 43-57; n = 12), M70 yrs (range 59-75; n = 12), and W70 yrs (range 62-75; n = 12), volunteered as subjects for examination of muscle cross-sectional area (CSA), maximal voluntary forces, force-time curves, and electromyographic activity of the knee extensor muscles during bilateral and unilateral isometric contractions. The maximal bilateral knee extension force and the average CSA values in M50 were greater (p < .05) than in M70 and in W50 were greater (p < .05-.001) than those recorded for W70. The early forces in the force-time curve were greater (p < .05) …