986,590 research outputs found
A rapid review to identify physical activity accrued while playing golf
Objective To identify physical activity (PA) accrued while playing golf and modifiers of PA accrued. Design A rapid review of primary research studies. Quality was assessed using the National Heart, Lung, and Blood Institute quality assessment tool for cohort and cross-sectional studies. Methods and outcomes The following databases were searched from 1900 to March 2017: SPORTDiscus, Web of Science, PsycINFO, MEDLINE, Google Scholar, Google Advanced Search, ProQuest, WHO International Clinical Trials Registry Platform. All primary research investigating golf or golfers with any of the following outcomes was included: metabolic equivalent of task, oxygen uptake, energy expenditure, heart rate, step count, distance covered, strength, flexibility, balance, sedentary behaviour. Results Phase one searching identified 4944 citations and phase two searching identified 170 citations. In total, 19 articles met inclusion criteria. Golf is primarily a moderate intensity PA, but may be low intensity depending on the playing population and various modifiers. Less PA is accrued by those who ride a golf cart compared with those walking the course. Conclusions Golf can be encouraged in order to attain PA recommendations. Further research is required into the relationship between golf and strength and flexibility PA recommendations and how modifiers affect PA accrued. PROSPERO registration number CRD42017058237.</p
Comparative studies on yield potential of some hevea clones in Cambodia
Cambodian Rubber Research Institute is carrying out researches on tapping systems to assess the influence of intensity of stimulation on yield at a given tapping frequency 1/2S d/3 7d/7. The objectives of these trials are to determine the yield potential of each clone at various intensity of hormonal stimulation. Five clones have been studied since March 2005. These clones are IRCA111, PB330, GT1, IRCA230 and AF261. Each trial consists of Fisher block design with 3 replications and four treatments per replication. Two protocols of stimulation were set up for different clones. The preliminary results show that the highest yields for the clone IRCA111 and PB330 are obtained with ET 1.5% Pa 1(1) 5/y (75 mg) and ET 2.5% Pa 1(1) 2/y (50 mg), respectively. Interestingly, the clones GT1 and IRCA230 give significant high yield at the most intensive treatments, ET 2.5% Pa 1(1) 6/y (150 mg). However, the clone AF261 does not response to more intensive stimulation system than ET 1.5% Pa 1(1) 5/y as the same yields are obtained at different intensities of stimulation. The clone GT1 gives the highest yield at increased stimulation intensity compared with other clones. (Texte intégral
Suppression of power-broadening in strong-coupling photoassociation in the presence of a Feshbach resonance
Photoassociation (PA) spectrum in the presence of a magnetic Feshbach
resonance is analyzed. Nonperturbative solution of the problem yields
analytical expressions for PA linewidth and shift which are applicable for
arbitrary PA laser intensity and magnetic field tuning of Feshbach Resonance.
We show that by tuning magnetic field close to Fano minimum, it is possible to
suppress power broadening at increased laser intensities. This occurs due to
quantum interference of PA transitions from unperturbed and perturbed
continuum. Line narrowing at high laser intensities is accompanied by large
spectral shifts. We briefly discuss important consequences of line narrowing in
cold collisions.Comment: 12 pages, 5 figure
Physical Activity Modulates Corticospinal Excitability of the Lower Limb in Young and Old Adults
Aging is associated with reduced neuromuscular function, which may be due in part to altered corticospinal excitability. Regular physical activity (PA) may ameliorate these age-related declines, but the influence of PA on corticospinal excitability is unknown. The purpose of this study was to determine the influence of age, sex, and PA on corticospinal excitability by comparing the stimulus-response curves of motor evoked potentials (MEP) in 28 young (22.4 ± 2.2 yr; 14 women and 14 men) and 50 old adults (70.2 ± 6.1 yr; 22 women and 28 men) who varied in activity levels. Transcranial magnetic stimulation was used to elicit MEPs in the active vastus lateralis muscle (10% maximal voluntary contraction) with 5% increments in stimulator intensity until the maximum MEP amplitude. Stimulus-response curves of MEP amplitudes were fit with a four-parameter sigmoidal curve and the maximal slope calculated (slopemax). Habitual PA was assessed with tri-axial accelerometry and participants categorized into either those meeting the recommended PA guidelines for optimal health benefits (\u3e10,000 steps/day, high-PA; n = 21) or those not meeting the guidelines (n = 41). The MEP amplitudes and slopemax were greater in the low-PA compared with the high-PA group (P \u3c 0.05). Neither age nor sex influenced the stimulus-response curve parameters (P \u3e 0.05), suggesting that habitual PA influenced the excitability of the corticospinal tract projecting to the lower limb similarly in both young and old adults. These findings provide evidence that achieving the recommended PA guidelines for optimal health may mediate its effects on the nervous system by decreasing corticospinal excitability
Altitude-dependent polarization in radio pulsars
Because of the corotation, the polarization angle (PA) curve of a pulsar lags
the intensity profile by 4r/Rlc rad in pulse phase. I present a simple and
short derivation of this delay-radius relation to show that it is not caused by
the aberration (understood as the normal beaming effect) but purely by
contribution of corotation to the electron acceleration in the observer's
frame. Available altitude-dependent formulae for the PA curve are expressed
through observables and emission altitude to make them immediately ready to use
in radio data modelling. The analytical approximations for the
altitude-dependent PA curve are compared with exact numerical results to show
how they perform at large emission altitudes. I also discuss several possible
explanations for the opposite-than-normal shift of PA curve, exhibited by the
pedestal emission of B1929+10 and B0950+08.Comment: 12 pages, 5 figures, accepted by MNRAS after minor change
Efficient production of polar molecular Bose-Einstein condensates via an all-optical R-type atom-molecule adiabatic passage
We propose a scheme of "-type" photoassociative adiabatic passage (PAP) to
create polar molecular condensates from two different species of ultracold
atoms. Due to the presence of a quasi-coherent population trapping state in the
scheme, it is possible to associate atoms into molecules with a
\textit{low-power} photoassociation (PA) laser. One remarkable advantage of our
scheme is that a tunable atom-molecule coupling strength can be achieved by
using a time-dependent PA field, which exhibits larger flexibility than using a
tunable magnetic field. In addition, our results show that the PA intensity
required in the "-type" PAP could be greatly reduced compared to that in a
conventional "-type" one.Comment: 17 pages, 5 figures, to appear in New Journal of Physic
Pulsars identified from the NRAO VLA Sky Survey
We identified 97 strong pulsars from the NRAO VLA Sky Survey (NVSS) at 1.4
GHz north of Dec(J2000) >-40\degr. The total flux density, linear
polarization intensity and polarization angle (PA) of all pulsars are extracted
from the NVSS catalog. The well-calibrated PA measurement of 5 pulsars can be
used for absolute PA calibrations in other observations. Comparing the source
positions with those in the pulsar catalog, we got the first measurement of the
proper motion upper limit of PSR B0031-07, which is and .Comment: 7 pages; 3 figures; one big table; To appear in A&A Supplement
Physical Activity Modulates Corticospinal Excitability of the Lower Limb in Young and Old Adults
Aging is associated with reduced neuromuscular function, which may be due in part to altered corticospinal excitability. Regular physical activity (PA) may ameliorate these age-related declines, but the influence of PA on corticospinal excitability is unknown. The purpose of this study was to determine the influence of age, sex, and PA on corticospinal excitability by comparing the stimulus-response curves of motor evoked potentials (MEP) in 28 young (22.4 ± 2.2 yr; 14 women and 14 men) and 50 old adults (70.2 ± 6.1 yr; 22 women and 28 men) who varied in activity levels. Transcranial magnetic stimulation was used to elicit MEPs in the active vastus lateralis muscle (10% maximal voluntary contraction) with 5% increments in stimulator intensity until the maximum MEP amplitude. Stimulus-response curves of MEP amplitudes were fit with a four-parameter sigmoidal curve and the maximal slope calculated (slopemax). Habitual PA was assessed with tri-axial accelerometry and participants categorized into either those meeting the recommended PA guidelines for optimal health benefits (\u3e10,000 steps/day, high-PA; n = 21) or those not meeting the guidelines (n = 41). The MEP amplitudes and slopemax were greater in the low-PA compared with the high-PA group (P \u3c 0.05). Neither age nor sex influenced the stimulus-response curve parameters (P \u3e 0.05), suggesting that habitual PA influenced the excitability of the corticospinal tract projecting to the lower limb similarly in both young and old adults. These findings provide evidence that achieving the recommended PA guidelines for optimal health may mediate its effects on the nervous system by decreasing corticospinal excitability
Assessment of physical activity in older Belgian adults : validity and reliability of an adapted interview version of the long International Physical Activity Questionnaire (IPAQ-L)
Background: Adequate monitoring of older adults’ physical activity (PA) is essential to develop effective health promotion programs. The present study examined criterion validity and test-retest reliability of the long International Physical Activity Questionnaire (IPAQ-L), adapted for Belgian, community-dwelling older adults (65y and older).
Methods: Participants (n = 434) completed the last seven days version of IPAQ-L, modified for the Belgian population of community-dwelling older adults. This elderly-adapted version of IPAQ-L combined vigorous and moderate activities, and questions on gait speed and recreational cycling were added. Furthermore, participants wore an ActiGraph GT3X(+) accelerometer for at least five days. Criterion validity was determined by comparing self-reported weekly minutes of moderate-to-vigorous physical activity (MVPA) and weekly minutes of total PA with accelerometer data, defined by two different cut points (Freedson vs. Copeland). To examine test-retest reliability, a subsample of 29 participants completed IPAQ-L for a second time within a ten day interval.
Results: IPAQ-L showed moderate criterion validity for measuring weekly minutes of MVPA and total PA (Spearman’s ρ range 0.33–0.40). However, plots on agreement between self-reported and accelerometer PA showed a systematic over-reporting of IPAQ-L for MVPA. In contrast, plots indicated that IPAQ-L under-estimated levels of total PA, however, this under-estimation of total PA was substantially lower than the observed over-reporting of MVPA. Test-retest reliability was moderate-to-good for work-related PA, domestic PA, MVPA and total PA (ICC range 0.52–0.81), but poorer for transportation and recreational PA (ICC 0.44 and 0.43, respectively).
Conclusions: Criterion validity results suggest that IPAQ-L is more valid to measure older adults’ weeklyminutes of total PA than weekly MVPA minutes. Moreover, results might imply that content validity of IPAQ-L can be improved if specific light-intensity PA items are incorporated into IPAQ-L. Test-retest reliability of IPAQ-L was moderate to good, except for weekly minutes of transportation and recreational PA, probably due to week-to-week variability of these behaviors
Measuring physical activity using accelerometry in 13-15-year-old adolescents : the importance of including non-wear activities
Objective: The present study aimed to examine the impact of non-wear activities registered in diaries when using accelerometers to assess physical activity (PA) in young adolescents.
Design: Data arise from a large-scale cross-sectional study on PA. PA was objectively assessed using Actigraph (TM) accelerometers (Actigraph MTI, Manufacturing Technology Inc., Pensacola, FL, USA) during seven consecutive days. Non-wear time activity diaries were provided to register the activities for which the accelerometer was removed. After correction to deal with over-reporting, the registered minutes of PA were used to replace periods of non-wear time measured by the accelerometer.
Setting: Between October 2008 and May 2009 adolescents were recruited by home visits in Ghent (Belgium).
Subjects: Young adolescents (n 513; 48.6% boys) aged 13 to 15 years.
Results: Of the total sample, 49.9% registered at least one activity of moderate to vigorous intensity in the non-wear time activity diary. More adolescents registered an activity performed on a weekday than on a weekend day and the registered mean number of minutes of moderate to vigorous PA were higher on weekend days. Repeated-measures (M) ANOVA tests revealed a significant difference between the mean minutes with and without non-wear activities for all PA intensities, regardless of adolescents' socio-economic status or gender. More adolescents achieved the PA recommendations after inclusion of the non-wear activities irrespective of accelerometer thresholds used.
Conclusions: The collection of information regarding non-wear time by non-wear time activity diaries when using accelerometers in 13-15-year-old adolescents can lead to different PA outcomes at the individual level and therefore can improve the ability to accurately measure PA
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