Application of the Speed-Duration Relationship to Normalize the Intensity of High-Intensity Interval Training

Science.gov (United States)

Ferguson, Carrie; Wilson, John; Birch, Karen M.; Kemi, Ole J.

2013-01-01

The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (PHIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P>0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P>0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols. PMID:24244266

Safety in Mixed Martial Arts: a 7-Year Review of Cancelled MMA Bouts in Calgary, Alberta, During the Pre-bout Medical Examination Period.

Science.gov (United States)

Curran-Sills, Gwynn

2018-01-12

Presently, there is no literature that examines the reasons for the cancellation of amateur or professional mixed martial arts (MMA) bouts. The purpose of this study was to review the circumstances that lead to the cancellation of MMA bouts by Calgary ringside physicians during the pre-bout examination period and to identify any emerging patterns that may guide the regulatoin of this sport. The case-series  was constructed from the Calgary Combative Sports Commission pre-bout examination records and the medical records submitted by each athlete from January 2010 to December 2016. Cancelled bouts in the pre-bout examination periods represented 5.4% of all MMA bouts in Calgary. A total of 25 reasons lead to bout cancellation and included the following: failure to obtain required neuroimaging (28.0%), neuroimaging abnormalities (24.0%), incomplete routine screening investigations (16.0%), exceeding maximum weight differential between the two athletes (16.0%), injury in the pre-competition period (8.0%), dehydration (4.0%), and ECG abnormalities (4.0%). The abnormalities on neuroimaging (n of 6) included the following: post traumatic gliosis on MRI (n = 1, 16.7%), flares diffusely and findings consistent with microhemorrhage on MRI (n = 1, 16.7%), chronic orbital fracture with fat pad extrusion on CT (n = 2, 33.3%), lacunar infarct on MRI (1), and unspecified MRI abnormality (n = 1, 16.7%). Twenty-two athletes had bouts cancelled and of these three athletes had their bouts stopped for two reasons. The following recommendations are presented and include: the creation of guidelines regarding pre- and post-bout neuroimaging, the implementation of industry-wide minimum medical screening standards, the adoption of a longitudinal approach to weight monitoring, the development of competent ringside physician groups, and active oversight by the Combative Sports Commission during the matchmaking process.

A single bout of exercise improves motor memory

DEFF Research Database (Denmark)

Roig, Marc; Skriver, Kasper Christen; Lundbye-Jensen, Jesper

2012-01-01

Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact on the acq...... exercise on long-term motor memory....... that exercised before practice, the subjects that exercised after practice showed a better retention of the motor skill 7 days after practice. These findings indicate that one bout of intense exercise performed immediately before or after practicing a motor task is sufficient to improve the long-term retention......Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact...

High-rate operant behavior in two mouse strains: a response-bout analysis.

Science.gov (United States)

Johnson, Joshua E; Pesek, Erin F; Newland, M Christopher

2009-06-01

Operant behavior sometimes occurs in bouts characterized by an initiation rate, within-bout response rate, and bout length. The generality of this structure was tested using high-rate nose-poking in mice. Reinforcement of short interresponse times produced high response rates while a random-interval schedule held reinforcement rates constant. BALB/c mice produced bouts that were more frequent, longer, and contained a higher within-bout rate of responding (nine nose-pokes/s) than did the C57BL/6 mice (five nose-pokes/s). Adding a running wheel decreased total nose-pokes and bout length, and increased bout-initiation rate. Free-feeding reduced nose-poking by decreasing bout-initiation rate. Photoperiod reversal decreased bout-initiation rate but not total nose-poke rate. Despite strain differences in bout structure, both strains responded similarly to the interventions. The three bout measures were correlated with overall rate but not with each other. Log-survival analyses provided independent descriptors of the structure of high-rate responding in these two strains.

Arousal and exposure duration affect forward step initiation

Directory of Open Access Journals (Sweden)

Daniëlle eBouman

2015-11-01

Full Text Available Emotion influences parameters of goal-directed whole-body movements in several ways. For instance, previous research has shown that approaching (moving toward pleasant stimuli is easier compared to approaching unpleasant stimuli. However, some studies found that when emotional pictures are viewed for a longer time, approaching unpleasant stimuli may in fact be facilitated. The effect of viewing duration may modulate whole-body approach movement in previous research but this has not been investigated before. In the current study, participants initiated a step forward after viewing neutral, high-arousal pleasant and high-arousal unpleasant stimuli. The viewing duration of the stimuli was set to 7 different durations, varying from 100 to 4000ms. Valence and arousal scores were collected for all stimuli.The results indicate that both viewing duration and the arousal of the stimuli influence kinematic parameters in forward gait initiation. Specifically, longer viewing duration, compared to shorter viewing duration, (a diminished the step length and peak velocity in both neutral and emotional stimuli, (b increased reaction time in neutral stimuli and, (c decreased reaction time in pleasant and unpleasant stimuli. Strikingly, no differences were found between high-arousal pleasant and high-arousal unpleasant stimuli. In other words, the valence of the stimuli did not influence kinematic parameters of forward step initiation. In contrast, the arousal level (neutral: low; pleasant and unpleasant: high explained the variance found in the results. The kinematics of forward gait initiation seemed to be reflected in the subjective arousal scores, but not the valence scores. So it seems arousal affects forward gait initiation parameters more strongly than valence. In addition, longer viewing duration seemed to cause diminished alertness, affecting GI parameters. These results shed new light on the prevailing theoretical interpretations regarding approach

Recent advances in the understanding of the repeated bout effect: the protective effect against muscle damage from a single bout of eccentric exercise.

Science.gov (United States)

McHugh, Malachy P

2003-04-01

The repeated bout effect refers to the adaptation whereby a single bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts. While the mechanism for this adaptation is poorly understood there have been significant recent advances in the understanding of this phenomenon. The purpose of this review is to provide an update on previously proposed theories and address new theories that have been advanced. The potential adaptations have been categorized as neural, mechanical and cellular. There is some evidence to suggest that the repeated bout effect is associated with a shift toward greater recruitment of slow twitch motor units. However, the repeated bout effect has been demonstrated with electrically stimulated contractions, indicating that a peripheral, non-neural adaptation predominates. With respect to mechanical adaptations there is evidence that both dynamic and passive muscle stiffness increase with eccentric training but there are no studies on passive or dynamic stiffness adaptations to a single eccentric bout. The role of the cytoskeleton in regulating dynamic stiffness is a possible area for future research. With respect to cellular adaptations there is evidence of longitudinal addition of sarcomeres and adaptations in the inflammatory response following an initial bout of eccentric exercise. Addition of sarcomeres is thought to reduce sarcomere strain during eccentric contractions thereby avoiding sarcomere disruption. Inflammatory adaptations are thought to limit the proliferation of damage that typically occurs in the days following eccentric exercise. In conclusion, there have been significant advances in the understanding of the repeated bout effect, however, a unified theory explaining the mechanism or mechanisms for this protective adaptation remains elusive.

Psychological stress exposure to aged mice causes abnormal feeding patterns with changes in the bout number.

Science.gov (United States)

Yamada, Chihiro; Mogami, Sachiko; Hattori, Tomohisa

2017-11-09

Stress responses are affected by aging. However, studies on stress-related changes in feeding patterns with aging subject are minimal. We investigated feeding patterns induced by two psychological stress models, revealing characteristics of stress-induced feeding patterns as "meal" and "bout" (defined as the minimum feeding behavior parameters) in aged mice. Feeding behaviors of C57BL/6J mice were monitored for 24 h by an automatic monitoring device. Novelty stress reduced the meal amount over the 24 h in both young and aged mice, but as a result of a time course study it was persistent in aged mice. In addition, the decreased bout number was more pronounced in aged mice than in young mice. The 24-h meal and bout parameters did not change in either the young or aged mice following water avoidance stress (WAS). However, the meal amount and bout number increased in aged mice for 0-6 h after WAS exposure but remained unchanged in young mice. Our findings suggest that changes in bout number may lead to abnormal stress-related feeding patterns and may be one tool for evaluating eating abnormality in aged mice.

How Changes in Financial Incentives Affect the Duration of Unemployment

NARCIS (Netherlands)

Lalive, R.; van Ours, J.C.; Zweimüller, J.

2004-01-01

This paper studies how changes in the two key parameters of unemployment insurance - the benefit replacement rate (RR) and the potential duration of benefits (PBD) - affect the duration of unemployment.In 1989, the Austrian government made unemployment insurance more generous by changing,

Differences in the Intensity and Duration of Adolescents' Sports and Exercise across Physical and Social Environments

Science.gov (United States)

Dunton, Genevieve Fridlund; Berrigan, David; Ballard-Barbash, Rachel; Perna, Frank; Graubard, Barry I.; Atienza, Audie A.

2012-01-01

We used data from the American Time Use Survey (years 2003-06) to analyze whether the intensity and duration of high school students' (ages 15-18 years) sports and exercise bouts differed across physical and social environments. Boys' sports and exercise bouts were more likely to reach a vigorous intensity when taking place at school and with…

Velocity-specific strength recovery after a second bout of eccentric exercise.

Science.gov (United States)

Barss, Trevor S; Magnus, Charlene R A; Clarke, Nick; Lanovaz, Joel L; Chilibeck, Philip D; Kontulainen, Saija A; Arnold, Bart E; Farthing, Jonathan P

2014-02-01

A bout of eccentric exercise (ECC) has the protective effect of reducing muscle damage during a subsequent bout of ECC known as the "repeated bout effect" (RBE). The purpose of this study was to determine if the RBE is greater when both bouts of ECC are performed using the same vs. different velocity of contraction. Thirty-one right-handed participants were randomly assigned to perform an initial bout of either fast (3.14 rad·s [180°·s]) or slow (0.52 rad·s [30°·s]) maximal isokinetic ECCs of the elbow flexors. Three weeks later, the participants completed another bout of ECC at the same velocity (n = 16), or at a different velocity (n = 15). Indirect muscle damage markers were measured before, immediately after, and at 24, 48, and 72 hours postexercise. Measures included maximal voluntary isometric contraction (MVC) strength (dynamometer), muscle thickness (MT; ultrasound), delayed onset muscle soreness (DOMS; visual analog scale), biceps and triceps muscle activation amplitude (electromyography), voluntary activation (interpolated twitch), and twitch torque. After the repeated bout, MVC strength recovered faster compared with the same time points after the initial bout for only the same velocity group (p = 0.017), with no differences for all the other variables. Irrespective of velocity, MT and DOMS were reduced after the repeated bout compared with that of the initial bout at 24, 48, and 72 hours with a corresponding increase in TT at 72 hours (p effects contribute to the RBE. The current findings support the idea of multiple mechanisms contributing to the RBE.

The bidirectional effect between momentary affective states and exercise duration on a day level

Directory of Open Access Journals (Sweden)

Anna Schöndube

2016-09-01

Full Text Available Despite the well-documented positive effect of exercise on health outcomes, most people do not succeed in exercising regularly. In addition to several other influences, affective states seem to support exercise participation. Associations between exercise and affect have been shown in the laboratory. However, the dynamic relation between affect and exercise in daily life is not yet well understood. The objective of this study was to investigate the bi-directional effect of momentary affective states on naturally occurring exercise and vice versa in healthy participants in real-life environments by applying an ecological momentary assessment design. We hypothesized that (1 exercise duration is positively associated with affective states on a day level, (2 affective states in the morning predict subsequent exercise duration, and (3 exercise duration predicts affective states in the evening on that respective day. Data from N = 60 students aged between 19 and 32 years were analyzed. Affect and exercise duration were assessed daily over a period of 20 days via an electronic diary. Multilevel analysis revealed that positive affective valence was positively associated with exercise duration (p = 0.003 on a day level. In addition, the more the participants exercised that respective day, the better and more content they felt in the evening (p = 0.009. Energetic arousal in the morning significantly predicted subsequent exercise duration (p = 0.045. The findings indicate that it would be worthwhile to focus more on within-subject analyses when analyzing the dynamic relation between affect and exercise. Furthermore, affective states should be taken into account in creating effective interventions to foster exercise behavior and enhance maintenance.

Exercise-induced muscle damage and the repeated bout effect: evidence for cross transfer.

Science.gov (United States)

Starbuck, Chelsea; Eston, Roger G

2012-03-01

We examined whether a prior bout of eccentric exercise in the elbow flexors provided protection against exercise-induced muscle damage in the contralateral arm. Fifteen males (age 22.7 ± 2.1 years; height 178.6 ± 6.8 cm, mass 75.8 ± 9.3 kg) were randomly assigned to two groups who performed two bouts of 60 eccentric contractions (30°/s) separated by 2 weeks: ipsilateral (n = 7, both bouts performed in the same arm), contralateral (n = 8, one bout performed in each arm). Strength, muscle soreness and resting arm angle (RAA) were measured at baseline and at 1, 24 and 48 h post exercise. Surface electromyography was recorded during both bouts of exercise. The degree of strength loss was attenuated (p < 0.05) in the ipsilateral group after the second bout of eccentric exercise (-22 cf. -3% for bout 1 and 2 at 24 h, respectively). Strength loss following eccentric exercise was also attenuated (p < 0.05) at 24 h in the contralateral group (-30 cf. 13% for bout 1 and 2, respectively). Muscle soreness (≈34 cf 19 mm) and change in RAA (≈5 cf. 3%) were also lower following the second bout of eccentric exercise (p < 0.05), although there was no difference in the overall change in these values between groups. Median frequency (MF) was decreased by 31% between bouts, with no difference between groups. Data support observations that the repeated bout effect transfers to the opposite (untrained) limb. The similar reduction in MF between bouts for the two groups provides evidence for a centrally mediated, neural adaptation.

Effect of anaerobic bout using wingate cycle ergometer on pressure pain threshold in normal individuals

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Ajit Dabholkar

2017-01-01

Full Text Available Introduction: Published studies reveal that incremental graded and short term anaerobic exercise lead to an increase in beta-endorphin levels, the extent correlating with the lactate concentration. Beta- endorphin can be released into the circulation from the pituitary gland or can project into areas of the brain through nerve fibers. Exercise of sufficient intensity and duration has been demonstrated to increase circulating Beta-endorphin levels. Thus, our study investigates the effect of anaerobic activity on pressure pain threshold (PPT in normal individuals. Materials and Methods: Normal individuals (N = 30 between the age group of 20-30 years were recruited for this study. The subjects performed an anaerobic bout on Monark Wingate cycle egometer. A pre and post assessment of PPT was evaluated. Data Analysis: Graphpad Instat 3 software program was used for statistical analysis. A paired't' test was done to analyse the level of statistical significance between the pre and post PPT. Results: Study revealed that post anaerobic bout there was statistical significant difference between pre and post PPT in quadriceps, Mean 14.41,95% CI[12.95,15.87], Mean 16.73,95% CI[15.06,18.40] & (P value 0.0411 and gastrocnemius,Mean 13.56, 95% CI[12.18,14.93], Mean 15.55,95% CI[13.94,17.16] & (P value <0.0001. Conclusion: The study emphasizes the influence of pain modulation after an anaerobic bout.

Human behaviours associated with dominance in elite amateur boxing bouts: A comparison of winners and losers under the Ten Point Must System.

Science.gov (United States)

Dunn, Emily C; Humberstone, Clare E; Iredale, K Fiona; Martin, David T; Blazevich, Anthony J

2017-01-01

Humans commonly ascertain physical dominance through non-lethal fighting by participating in combat sports. However, the behaviours that achieve fight dominance are not fully understood. Amateur boxing competition, which is judged using the subjective "Ten Point Must-System", provides insight into fight dominance behaviours. Notational analysis was performed on 26 elite male competitors in a national boxing championship. Behavioural (guard-drop time; movement style [stepping/bouncing time]; clinch-time; interaction-time) and technical (total punches; punches landed [%Hit]; air punches [%Air]; defence) measures were recorded. Participants reported effort required (0-100%) and perceived effect of fatigue on their own performance (5-point Likert scale) following bouts. Differences between winners and losers, and changes across the duration of the bout were examined. Winners punched more accurately than losers (greater %Hit [33% vs. 23%] and lower %Air [17% vs. 27%]) but total punches, defence and interaction-time were similar. From rounds 1-2, clinch-time and guard drops increased whilst bouncing decreased. Perceived effect of fatigue increased throughout the bout while perceived effort increased only from rounds 2-3. %Hit and movement index together in regression analysis correctly classified 85% of bout outcomes, indicating that judges (subjectively) chose winning (dominant) boxers according to punch accuracy and style, rather than assertiveness (more punches thrown). Boxers appear to use tactical strategies throughout the bout to pace their effort and minimise fatigue (increased guard drops, reduced bouncing), but these did not influence perceived dominance or bout outcome. These results show that judges use several performance indicators not including the total number of successful punches thrown to assess fight dominance and superiority between fighters. These results provide valuable information as to how experienced fight observers subjectively rate superiority

Is environmental setting associated with the intensity and duration of children's physical activity? Findings from the SPEEDY GPS study.

Science.gov (United States)

Coombes, Emma; van Sluijs, Esther; Jones, Andy

2013-03-01

Using a sample of English school children, we use accelerometery and global positioning systems to identify whether different intensities of activity (light, moderate, and vigorous) occur in different environments, and whether environments for bouts of moderate to vigorous activity (MVPA) vary from those for non-bout MVPA. We find that land uses such as buildings and roads and pavements were generally used for light activity, whilst green environments such as gardens, parks, grassland and farmland appear supportive of vigorous activity. Built land uses such as hard surface play areas were particularly used for activity of short duration. Future work may consider differentiating light activity from moderate and vigorous, and separating bout and non-bout MVPA to better identify environmental supportiveness for activity in children. Copyright © 2013 Elsevier Ltd. All rights reserved.

Short Duration Small Sided Football and to a Lesser Extent Whole Body Vibration Exercise Induce Acute Changes in Markers of Bone Turnover

DEFF Research Database (Denmark)

Bowtell, J. L.; Jackman, S. R.; Scott, S.

2016-01-01

We aimed to study whether short-duration vibration exercise or football sessions of two different durations acutely changed plasma markers of bone turnover and muscle strain. Inactive premenopausal women (n = 56) were randomized to complete a single bout of short (FG15) or long duration (FG60) sm...

Muscle damage and repeated bout effect induced by enhanced eccentric squats.

Science.gov (United States)

Coratella, Giuseppe; Chemello, Alessandro; Schena, Federico

2016-12-01

Muscle damage and repeated bout effect have been studied after pure eccentric-only exercise. The aim of this study was to evaluate muscle damage and repeated bout effect induced by enhanced eccentric squat exercise using flywheel device. Thirteen healthy males volunteered for this study. Creatine kinase blood activity (CK), quadriceps isometric peak torque and muscle soreness were used as markers of muscle damage. The dependent parameters were measured at baseline, immediately after and each day up to 96 hours after the exercise session. The intervention consisted of 100 repetitions of enhanced eccentric squat exercise using flywheel device. The same protocol was repeated after 4 weeks. After the first bout, CK and muscle soreness were significantly greater (P0.05), while isometric peak torque and muscle soreness returned to values similar to baseline after respectively 48 and 72 hours. All muscle damage markers were significantly lower after second compared to first bout. The enhanced eccentric exercise induced symptoms of muscle damage up to 96 hours. However, it provided muscle protection after the second bout, performed four weeks later. Although it was not eccentric-only exercise, the enhancement of eccentric phase provided muscle protection.

Role of the locus coeruleus in the emergence of power law wake bouts in a model of the brainstem sleep-wake system through early infancy.

Science.gov (United States)

Patel, Mainak; Rangan, Aaditya

2017-08-07

Infant rats randomly cycle between the sleeping and waking states, which are tightly correlated with the activity of mutually inhibitory brainstem sleep and wake populations. Bouts of sleep and wakefulness are random; from P2-P10, sleep and wake bout lengths are exponentially distributed with increasing means, while during P10-P21, the sleep bout distribution remains exponential while the distribution of wake bouts gradually transforms to power law. The locus coeruleus (LC), via an undeciphered interaction with sleep and wake populations, has been shown experimentally to be responsible for the exponential to power law transition. Concurrently during P10-P21, the LC undergoes striking physiological changes - the LC exhibits strong global 0.3 Hz oscillations up to P10, but the oscillation frequency gradually rises and synchrony diminishes from P10-P21, with oscillations and synchrony vanishing at P21 and beyond. In this work, we construct a biologically plausible Wilson Cowan-style model consisting of the LC along with sleep and wake populations. We show that external noise and strong reciprocal inhibition can lead to switching between sleep and wake populations and exponentially distributed sleep and wake bout durations as during P2-P10, with the parameters of inhibition between the sleep and wake populations controlling mean bout lengths. Furthermore, we show that the changing physiology of the LC from P10-P21, coupled with reciprocal excitation between the LC and wake population, can explain the shift from exponential to power law of the wake bout distribution. To our knowledge, this is the first study that proposes a plausible biological mechanism, which incorporates the known changing physiology of the LC, for tying the developing sleep-wake circuit and its interaction with the LC to the transformation of sleep and wake bout dynamics from P2-P21. Copyright © 2017 Elsevier Ltd. All rights reserved.

Blood flow variation in human muscle during electrically stimulated exercise bouts.

Science.gov (United States)

Vanderthommen, Marc; Depresseux, Jean-Claude; Dauchat, Luc; Degueldre, Christian; Croisier, Jean-Louis; Crielaard, Jean-Michel

2002-07-01

To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the mechanisms of muscle spatial recruitment during NMES. One thigh was submitted to 3 stimulation bouts of different durations (S1=4min, S2=8min, S3=12min) with a workload corresponding to 10% of quadriceps maximal isometric voluntary torque. A cyclotron research center at a Belgian university. Ten healthy male volunteers. Not applicable. Participants were studied with positron emission tomography and H(2)(15)O. Tissue blood flow was evaluated during the last 4 minutes of each stimulation bout in multiple regions of interest (ROIs) selected in the transverse section of the stimulated thigh. Mean tissue blood flow was significantly lower during S1 (5.9+/-1.3mL. min(-1). 100g(-1)) than during S2 (10.6+/-3.4mL. min(-1). 100g(-1)) and S3 (11.6+/-3.7mL. min(-1). 100g(-1)) (Precruited ROIs were preferentially located far from the electrode. During NMES, new muscular regions situated far from the stimulation site are recruited. These recruitment mechanisms are particular and contrast with the recruitment of motor units seen during voluntary contraction. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

OpenAIRE

Kliszczewicz Brian; John Quindry C.; Daniel Blessing L.; Gretchen Oliver D.; Michael Esco R.; Kyle Taylor J.

2015-01-01

CrossFit?, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit? bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ? 2.7 yrs havi...

Acute effects of repeated bouts of aerobic exercise on arterial stiffness after glucose ingestion.

Science.gov (United States)

Kobayashi, Ryota; Hashimoto, Yuto; Hatakeyama, Hiroyuki; Okamoto, Takanobu

2018-03-22

The aim of this study was to investigate the acute repeated bouts of aerobic exercise decrease leg arterial stiffness. However, the influence of repeated bouts of aerobic exercise on arterial stiffness after glucose ingestion is unknown. The present study investigates the acute effects of repeated bouts of aerobic exercise on arterial stiffness after the 75-g oral glucose tolerance test (OGTT). Ten healthy young men (age, 23.2 ± 0.9 years) performed repeated bouts of aerobic exercise trial (RE, 65% peak oxygen uptake; two 15 min bouts of cycling performed 20 min apart) and control trial (CON, seated and resting in a quiet room) at 80 min before the 75-g OGTT on separate days in a randomized, controlled crossover fashion. Carotid-femoral (aortic) and femoral-ankle (leg) pulse wave velocity, carotid augmentation index, brachial and ankle blood pressure, heart rate and blood glucose and insulin levels were measured before (baseline) and 30, 60 and 120 min after the 75-g OGTT. Leg pulse wave velocity, ankle systolic blood pressure and blood glucose levels increased from baseline after the 75-g OGTT in the CON trial, but not in the RE trial. The present findings indicate that acute repeated bouts of aerobic exercise before glucose ingestion suppress increases in leg arterial stiffness following glucose ingestion. RE trial repeated bouts of aerobic exercise trial; CON trial control trial; BG blood glucose; VO 2peak peak oxygen uptake; PWV Pulse wave velocity; AIx carotid augmentation index; BP blood pressure; HR heart rate; CVs coefficients of variation; RPE Ratings of perceived exertion; SE standard error.

Effect of the number of ball contacts within bouts of 4 vs. 4 small-sided soccer games.

Science.gov (United States)

Dellal, Alexandre; Lago-Penas, Carlos; Wong, Del P; Chamari, Karim

2011-09-01

The aim of this study was to examine the influence of the number of ball touches authorized per possession on the physical demands, technical performances and physiological responses throughout the bouts within 4 vs. 4 soccer small-sided games (SSGs). Twenty international soccer players (27.4 ± 1.5 y, 180.6 ± 2.3 cm, 79.2 ± 4.2 kg, body fat 12.7 ± 1.2%) performed three different 4 vs. 4 SSGs (4 × 4 min) in which the number of ball touches authorized per possession was manipulated (1 touch = 1T; 2 touches = 2T; Free Play = FP). The SSGs were divided in 4 bouts (B1, B2, B3 and B4) separated by 3 min of passive recovery. The physical performances, technical activities, heart rate responses, blood lactate and RPE were analyzed. The FP rule presented greater number of duels, induced the lowest decreases of the sprint and high-intensity performances, and affected less the technical actions (successful passes and number of ball losses) from B1 to B4 as compared with 1T and 2T forms. Moreover, the SSG played in 1T form led to reach higher solicitation of the high-intensity actions while players presented more difficulty to perform a correct technical action. The modification of the number of ball touches authorized per possession affects the soccer player activity from the first to the last bout of SSG, indicating that the determination of this rule has to be precisely planned by the coach according to the objectives of the training.

Daily events are important for age differences in mean and duration for negative affect but not positive affect.

Science.gov (United States)

Charles, Susan T; Mogle, Jacqueline; Urban, Emily J; Almeida, David M

2016-11-01

Across midlife and into old age, older adults often report lower levels of negative affect and similar if not higher levels of positive affect than relatively younger adults. Researchers have offered a simple explanation for this result: Age is related to reductions in stressors and increases in pleasurable activities that result in higher levels of well-being. The current study examines subjective reports of emotional experience assessed across 8 days in a large sample of adults (N = 2,022) ranging from 35 to 84 years old. By modeling age differences before and after adjusting for daily positive uplifts and negative stressors, this article assesses the extent to which daily events account for age differences in positive and negative affect reports. Consistent with previous research, the authors found that older age is related to lower mean levels and shorter duration of a negative emotional experience in a model only adjusting for gender, education, and ethnicity. After adjusting for daily events, however, the linear age-related effects were no longer significant. For positive affect, adjusting for daily events did not alter age-related patterns of experiencing higher mean levels and longer positive experience duration, suggesting that other factors underlie age-related increases in positive affect. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Flexibility training and the repeated-bout effect: priming interventions prior to eccentric training of the knee flexors.

Science.gov (United States)

Leslie, Andrew W; Lanovaz, Joel L; Andrushko, Justin W; Farthing, Jonathan P

2017-10-01

Both the repeated-bout effect and increased flexibility have been linked to reduced muscle damage, fatigue, and strength loss after intense eccentric exercise. Our purpose was to compare the eccentric-training (ECC) response after first priming the muscles with either static flexibility training or a single intense bout of eccentric exercise. Twenty-five participants were randomly assigned to flexibility training (n = 8; 3×/week; 30 min/day), a single bout of intense eccentric exercise (n = 9), or no intervention (control; n = 8) during a 4-week priming phase, prior to completing a subsequent 4-week period of eccentric training of the knee flexors. Testing was completed prior to the priming phase, before ECC, during acute ECC (0 h, 24 h, and 48 h after bouts 1 and 4), and after ECC. Measures included muscle thickness (MT; via ultrasound); isometric, concentric, and eccentric strength; muscle power (dynamometer); electromyography; range of motion; optimal angle of peak torque; and soreness (visual analog scale). Flexibility training and single-bout groups had 47% less soreness at 48 h after the first bout of ECC compared with control (p training group had 10% less soreness at 48 h after the fourth ECC bout compared with both the single-bout and control groups (p training group (-9%) after the fourth ECC bout compared with control (-19%; p training may be more effective than a single session of eccentric exercise in reducing adverse symptoms during the acute stages of eccentric training; however, these benefits did not translate into greater performance after training.

The duration of light treatment and therapy outcome in seasonal affective disorder

NARCIS (Netherlands)

Knapen, S. E.; van de Werken, M.; Gordijn, Marijke; Meesters, Y.

Background: Seasonal affective disorder (SAD) is characterized by recurrent episodes of major depression with a seasonal pattern, treated with light therapy (LT). Duration of light therapy differs. This study investigates retrospectively whether a single week of LT is as effective as two weeks,

EFFECTS OF A 4-WEEK ECCENTRIC TRAINING PROGRAM ON THE REPEATED BOUT EFFECT IN YOUNG ACTIVE WOMEN

Directory of Open Access Journals (Sweden)

Rodrigo Fernandez-Gonzalo

2011-12-01

Full Text Available The aim of this study was to analyze the responses of women to the repeated bout effect (RBE and to a short eccentric training program. Twenty-four young females were randomly assigned to a training group (TG, n = 14 or a control group (CG, n = 10. They performed two identical acute eccentric bouts (120 repetitions at 70% of 1RM in a leg-press device in an 8 weeks interval. TG followed a 4-week-eccentric-training program between the bouts. Maximal isometric contraction, range of motion, peak power and quadriceps muscle soreness were compared between and within groups before and after the two acute eccentric bouts. TG and CG presented significant losses of isometric strength and peak power, and an increment in soreness after the first bout. Isometric strength and peak power were recovered faster in CG after the second bout (p < 0.05 compared with TG, which showed a similar recovery of these parameters after the second bout compared with the first one. A decrease in soreness and a faster recovery of range of motion were found in TG (p < 0.05 following the second bout compared with the first one, but not in CG. Data indicate that a 4-week eccentric training program may prevent the RBE over those adaptations related with muscle damage (e.g. strength loss, but it may increase RBE impact on inflammatory processes (e.g. soreness.

Intermittent Standing but not a Moderate Exercise Bout Reduces Postprandial Glycemia

DEFF Research Database (Denmark)

Benatti, Fabiana B; Larsen, Sidsel A; Kofoed, Katja

2017-01-01

moderate-intensity walking bout followed by 8.5 h of sitting (MVPA), and 30-min moderate-intensity walking bout followed by 15-min standing bouts every 30 min during 8.5 h of sitting (MVPA + STAND). Three standardized meals on intervention day (day 1) and breakfast the following day (day 2) were served....... RESULTS: Cumulative postprandial glucose response (incremental area under the curve) was lower in STAND versus SIT (↓27%, P = 0.04, effect size [ES] = -0.7) because of decreases in postprandial glucose after breakfast on day 1 (STAND vs SIT: ↓40%, P = 0.01, ES = -0.7) and day 2 (STAND vs SIT: ↓33%, P = 0...... breakfast on day 1 only (MVPA vs SIT: ↓36%, P = 0.003, ES = -0.7; MVPA + STAND vs SIT: ↓43%, P = 0.0001, ES = -0.8). CONCLUSION: Breaking up prolonged sitting with nonambulatory standing across 9 h acutely reduced postprandial glycemic response during and the day after the intervention independent...

Appetite, food intake and gut hormone responses to intense aerobic exercise of different duration.

Science.gov (United States)

Holliday, Adrian; Blannin, Andrew

2017-12-01

The purpose of the study is to investigate the effect of acute bouts of high-intensity aerobic exercise of differing durations on subjective appetite, food intake and appetite-associated hormones in endurance-trained males. Twelve endurance-trained males (age = 21 ± 2 years; BMI = 21.0 ± 1.6 kg/m 2 ; VO 2max  = 61.6 ± 6.0 mL/kg/min) completed four trials, within a maximum 28 day period, in a counterbalanced order: resting (REST); 15 min exercise bout (15-min); 30 min exercise bout (30-min) and 45 min exercise bout (45-min). All exercise was completed on a cycle ergometer at an intensity of ~76% VO 2max Sixty minutes post exercise, participants consumed an ad libitum meal. Measures of subjective appetite and blood samples were obtained throughout the morning, with plasma analyzed for acylated ghrelin, total polypeptide tyrosine-tyrosine (PYY) and total glucagon-like peptide 1 (GLP-1) concentrations. The following results were obtained: Neither subjective appetite nor absolute food intake differed between trials. Relative energy intake (intake - expenditure) was significantly greater after REST (2641 ± 1616 kJ) compared with both 30-min (1039 ± 1520 kJ) and 45-min (260 ± 1731 kJ), and significantly greater after 15-min (2699 ± 1239 kJ) compared with 45-min (condition main effect, P  exercise in 30-min and 45-min, respectively (condition × time interaction, P  exercise trials (condition × time interaction, P  = 0.011); the greatest, most enduring suppression, was observed in 45-min. PYY concentration was unchanged with exercise. In conclusion, high-intensity aerobic cycling lasting up to 45 min did not suppress subjective appetite or affect absolute food intake, but did reduce relative energy intake, in well-trained endurance athletes. Findings question the role of appetite hormones in regulating subjective appetite in the acute post-exercise period. © 2017 Society for Endocrinology.

Circulatory response evoked by a 3 s bout of dynamic leg exercise in humans

NARCIS (Netherlands)

Wieling, W.; Harms, M. P.; ten Harkel, A. D.; van Lieshout, J. J.; Sprangers, R. L.

1996-01-01

1. The mechanisms underlying the pronounced transient fall in arterial blood pressure evoked by a 3 s bout of bicycle exercise were investigated in twenty healthy young adults and four patients with hypoadrenergic orthostatic hypotension. 2. In healthy subjects a 3 s bout of upright cycling induced

Evaluation of muscle activity during a standardized shoulder resistance training bout in novice individuals

DEFF Research Database (Denmark)

Jakobsen, Markus D; Sundstrup, Emil; Andersen, Christoffer H

2012-01-01

training bout. The purpose of this study was to evaluate muscle activity during a shoulder resistance training bout with 15 repetitions maximum (RM) loadings in novice individuals. Twelve healthy sedentary women (age = 27-58 years; weight = 54-85 kg; height = 160-178 cm) were recruited for this study...

Do changes in the pace of events affect one-off judgments of duration?

Science.gov (United States)

Darlow, Hannah M; Dylman, Alexandra S; Gheorghiu, Ana I; Matthews, William J

2013-01-01

Five experiments examined whether changes in the pace of external events influence people's judgments of duration. In Experiments 1a-1c, participants heard pieces of music whose tempo accelerated, decelerated, or remained constant. In Experiment 2, participants completed a visuo-motor task in which the rate of stimulus presentation accelerated, decelerated, or remained constant. In Experiment 3, participants completed a reading task in which facts appeared on-screen at accelerating, decelerating, or constant rates. In all experiments, the physical duration of the to-be-judged interval was the same across conditions. We found no significant effects of temporal structure on duration judgments in any of the experiments, either when participants knew that a time estimate would be required (prospective judgments) or when they did not (retrospective judgments). These results provide a starting point for the investigation of how temporal structure affects one-off judgments of duration like those typically made in natural settings.

Do changes in the pace of events affect one-off judgments of duration?

Directory of Open Access Journals (Sweden)

Hannah M Darlow

Full Text Available Five experiments examined whether changes in the pace of external events influence people's judgments of duration. In Experiments 1a-1c, participants heard pieces of music whose tempo accelerated, decelerated, or remained constant. In Experiment 2, participants completed a visuo-motor task in which the rate of stimulus presentation accelerated, decelerated, or remained constant. In Experiment 3, participants completed a reading task in which facts appeared on-screen at accelerating, decelerating, or constant rates. In all experiments, the physical duration of the to-be-judged interval was the same across conditions. We found no significant effects of temporal structure on duration judgments in any of the experiments, either when participants knew that a time estimate would be required (prospective judgments or when they did not (retrospective judgments. These results provide a starting point for the investigation of how temporal structure affects one-off judgments of duration like those typically made in natural settings.

Ambulatory blood pressure response to a bout of HIIT in metabolic syndrome patients.

Science.gov (United States)

Ramirez-Jimenez, M; Morales-Palomo, F; Pallares, J G; Mora-Rodriguez, Ricardo; Ortega, J F

2017-07-01

The effectiveness of exercise to lower blood pressure may depend on the type and intensity of exercise. We study the short-term (i.e., 14-h) effects of a bout of high-intensity aerobic interval training (HIIT) on blood pressure in metabolic syndrome (MetS) patients. Nineteen MetS patients (55.2 ± 7.3 years, 6 women) entered the study. Eight of them were normotensive and eleven hypertensive according to MetS threshold (≥130 mmHg for SBP and/or ≥85 mmHg for DBP). In the morning of 3 separated days, they underwent a cycling exercise bout of HIIT (>90% of maximal heart rate, ~85% VO 2max ), or a bout of isocaloric moderate-intensity continuous training (MICT; ~70% of maximal heart rate, ~60% VO 2max ), or a control no-exercise trial (REST). After exercise, ambulatory blood pressure (ABP; 14 h) was monitored, while subjects continued their habitual daily activities wearing a wrist-band activity monitor. No ABP differences were found for normotensive subjects. In hypertensive subjects, systolic ABP was reduced by 6.1 ± 2.2 mmHg after HIIT compared to MICT and REST (130.8 ± 3.9 vs. 137.4 ± 5.1 and 136.4 ± 3.8 mmHg, respectively; p HIIT exercise bout is superior to an equivalent bout of continuous exercise when used as a non-pharmacological aid in the treatment of hypertension in MetS.

Factors affecting gestation duration in the bitch.

Science.gov (United States)

Eilts, Bruce E; Davidson, Autumn P; Hosgood, Giselle; Paccamonti, Dale L; Baker, David G

2005-07-15

A retrospective analysis was performed to determine the effects of age, breed, parity, and litter size on the duration of gestation in the bitch. Bitches at two locations were monitored from breeding to whelping. A total of 764 litters whelped from 308 bitches (36 large hounds, 34 Golden Retrievers, 23 German Shepherd Dogs (GSD), and 215 Labrador Retrievers). By breed, the number of whelpings was 152, 72, 58, and 482 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. Whelping was predicted to be 57 d from the first day of cytologic diestrus in the hounds or 65 d from the initial progesterone rise in the other breeds. The average gestation duration (calculated as 8 d prior to Day 1 of cytologic diestrus in hounds or measured from the initial progesterone rise in other breeds) by breed (days +/- S.D.) was 66.0 +/- 2.8, 64.7 +/- 1.5, 63.6 +/- 2.1, and 62.9 +/- 1.3 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. The relationship of age, breed, parity, and litter size with the difference in gestation duration was evaluated using log linear modeling. Age or parity had no effect on gestation duration. Compared to Labrador Retrievers, the German Shepherd Dogs, Golden Retrievers and hounds were more likely to have a longer gestation duration; three, four and nearly eight times as likely, respectively. Bitches whelping four or fewer pups were significantly more likely to have a longer gestation duration than those whelping five or more pups; the prolongation averaging 1 d.

Detecting free-living steps and walking bouts: validating an algorithm for macro gait analysis.

Science.gov (United States)

Hickey, Aodhán; Del Din, Silvia; Rochester, Lynn; Godfrey, Alan

2017-01-01

Research suggests wearables and not instrumented walkways are better suited to quantify gait outcomes in clinic and free-living environments, providing a more comprehensive overview of walking due to continuous monitoring. Numerous validation studies in controlled settings exist, but few have examined the validity of wearables and associated algorithms for identifying and quantifying step counts and walking bouts in uncontrolled (free-living) environments. Studies which have examined free-living step and bout count validity found limited agreement due to variations in walking speed, changing terrain or task. Here we present a gait segmentation algorithm to define free-living step count and walking bouts from an open-source, high-resolution, accelerometer-based wearable (AX3, Axivity). Ten healthy participants (20-33 years) wore two portable gait measurement systems; a wearable accelerometer on the lower-back and a wearable body-mounted camera (GoPro HERO) on the chest, for 1 h on two separate occasions (24 h apart) during free-living activities. Step count and walking bouts were derived for both measurement systems and compared. For all participants during a total of almost 20 h of uncontrolled and unscripted free-living activity data, excellent relative (rho  ⩾  0.941) and absolute (ICC (2,1)   ⩾  0.975) agreement with no presence of bias were identified for step count compared to the camera (gold standard reference). Walking bout identification showed excellent relative (rho  ⩾  0.909) and absolute agreement (ICC (2,1)   ⩾  0.941) but demonstrated significant bias. The algorithm employed for identifying and quantifying steps and bouts from a single wearable accelerometer worn on the lower-back has been demonstrated to be valid and could be used for pragmatic gait analysis in prolonged uncontrolled free-living environments.

Skeletal muscle fiber type composition and performance during repeated bouts of maximal, concentric contractions

Science.gov (United States)

Colliander, E. B.; Dudley, G. A.; Tesch, P. A.

1988-01-01

Force output and fatigue and recovery patterns were studied during intermittent short-term exercise. 27 men performed three bouts of 30 maximal unilateral knee extensions on 2 different occasions. Blood flow was maintained or occluded during recovery periods (60 s). Blood flow was restricted by inflating a pneumatic cuff placed around the proximal thigh. Muscle biopsies from vastus lateralis were analyzed for identification of fast twitch (FT) and slow twitch (ST) fibers and relative FT area. Peak torque decreased during each bout of exercise and more when blood flow was restricted during recovery. Initial peak torque (IPT) and average peak torque (APT) decreased over the three exercise bouts. This response was 3 fold greater without than with blood flow during recovery. IPT and APT decreased more in individuals with mainly FT fibers than in those with mainly ST fibers. It is suggested that performance during repeated bouts of maximal concentric contractions differs between individuals with different fiber type composition. Specifically, in high intensity, intermittent exercise with emphasis on anaerobic energy release a high FT composition may not necessarily be advantageous for performance.

The prognostic ability of the STarT Back Tool was affected by episode duration

DEFF Research Database (Denmark)

Morsø, Lars; Kongsted, Alice; Hestbæk, Lise

2016-01-01

were not systematically affected by SBT risk subgroup (non-stratified care). Using generalised estimating equations, we investigated statistical interactions between SBT risk subgroups and potentially influential factors on the prognostic ability of the SBT subgroups, when Roland Morris Disability...... Questionnaire scores were the outcome. RESULTS: SBT risk subgroup, age, care setting, and episode duration were all independent prognostic factors. The only investigated factor that modified the prognostic ability of the SBT subgroups was episode duration. CONCLUSIONS: These results indicate that the prognostic...

Breath-hold duration in man and the diving response induced by face immersion.

Science.gov (United States)

Sterba, J A; Lundgren, C E

1988-09-01

The objective of this study in 5 selected volunteer subjects was to see whether the circulatory diving response which is elicited by breath holding and by cold water on the face would affect the duration of maximal-effort breath holds. Compared to control measurements (breath holding during resting, breathing with 35 degrees C water on the face) breath holding with the face cooled by 20 degrees C water caused a 12% reduction of heart rate, 6% reduction of cardiac output, 33% reduction in [corrected] forearm blood flow, and 9% rise in mean arterial blood pressure, but there was no difference in breath-hold duration (control and experimental both 94 s). There were also no differences in time of appearance of the first involuntary respiratory efforts during breath holding, in alveolar gas exchange, or in breaking-point alveolar O2 and CO2 tensions. When the diving response was magnified by a brief bout of exercise so that there was a 19% [corrected] reduction in heart rate, 23% reduction in cardiac output, and 48% reduction in forearm blood flow, breath-hold duration was still unaffected by face cooling. Compared to intermittent immersions, continuous exposure of the face to cold water abolished the diving response, probably by a cold adaptation of facial thermal receptors. These results with cooling of the face only are consistent with our earlier finding that there was a negative correlation between the duration of a maximal-effort breath hold and the diving response during whole-body submersion in cold water.

The Effect of Different Repeated-High-Intensity-Effort Bouts on Subsequent Running, Skill Performance, and Neuromuscular Function.

Science.gov (United States)

Johnston, Rich D; Gabbett, Tim J; Jenkins, David G; Speranza, Michael J

2016-04-01

To assess the impact of different repeated-high-intensity-effort (RHIE) bouts on player activity profiles, skill involvements, and neuromuscular fatigue during small-sided games. 22 semiprofessional rugby league players (age 24.0 ± 1.8 y, body mass 95.6 ± 7.4 kg). During 4 testing sessions, they performed RHIE bouts that each differed in the combination of contact and running efforts, followed by a 5-min off-side small-sided game before performing a second bout of RHIE activity and another 5-min small-sided game. Global positioning system microtechnology and video recordings provided information on activity profiles and skill involvements. A countermovement jump and a plyometric push-up assessed changes in lower- and upper-body neuromuscular function after each session. After running-dominant RHIE bouts, players maintained running intensities during both games. In the contact-dominant RHIE bouts, reductions in moderate-speed activity were observed from game 1 to game 2 (ES = -0.71 to -1.06). There was also moderately lower disposal efficiency across both games after contact-dominant RHIE activity compared with running-dominant activity (ES = 0.62-1.02). Greater reductions in lower-body fatigue occurred as RHIE bouts became more running dominant (ES = -0.01 to -1.36), whereas upper-body fatigue increased as RHIE bouts became more contact dominant (ES = -0.07 to -1.55). Physical contact causes reductions in running intensity and the quality of skill involvements during game-based activities. In addition, the neuromuscular fatigue experienced by players is specific to the activities performed.

Every exercise bout matters

DEFF Research Database (Denmark)

Dethlefsen, Christine; Pedersen, Katrine Seide; Hojman, Pernille

2017-01-01

Cumulative epidemiological evidence shows that regular exercise lowers the risk of developing breast cancer and decreases the risk of disease recurrence. The causality underlying this relation has not been fully established, and the exercise recommendations for breast cancer patients follow...... the general physical activity guidelines, prescribing 150 min of exercise per week. Thus, elucidations of the causal mechanisms are important to prescribe and implement the most optimal training regimen in breast cancer prevention and treatment. The prevailing hypothesis on the positive association within...... exercise oncology has focused on lowering of the basal systemic levels of cancer risk factors with exercise training. However, another rather overlooked systemic exercise response is the marked acute increases in several potential anti-cancer components during each acute exercise bout. Here, we review...

Post-exercise hypotensive responses following an acute bout of aquatic and overground treadmill walking in people post-stroke: a pilot study.

Science.gov (United States)

Lai, Byron; Jeng, Brenda; Vrongistinos, Konstantinos; Jung, Taeyou

2015-06-01

The purpose of this study is to investigate the effects of a single-bout of aquatic treadmill walking (ATW) and overground treadmill walking (OTW) on the magnitude and duration of post-exercise ambulatory blood pressure (BP) in people post-stroke. Seven people post-stroke participated in a cross-sectional comparative study. BP was monitored for up to 9 hours after a 15-minute bout of ATW and OTW at approximately 70% of maximal oxygen consumption (VO2max), performed on separate days. Mean systolic and diastolic BP values were compared between both exercise conditions and a day without exercise (control). Three hours after OTW, mean SBP increased by 9% from pre-exercise baseline compared to a 3% decrease during the control day (P stroke can sustain sufficient walking intensities necessary to reduce BP following cardiovascular exercise. Also, these data suggest that ATW can elicit clinically meaningful reductions in DBP and night-time SBP. Thus, it is recommended for clinicians to consider ATW as a non-pharmaceutical means to regulate DBP and promote nighttime dipping of SBP in people post-stroke. However, caution is advised during the immediate hours after exercise, a period of possible BP inflation.

Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

Directory of Open Access Journals (Sweden)

Kliszczewicz Brian

2015-09-01

Full Text Available CrossFit™, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit™ bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit™ experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE, immediately-post-exercise (IPE, 1 hr-post (1-HP and 2 hr-post (2-HP, to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit™ and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit™=+143%,Treadmill=+115% and 2-HP (CrossFit™=+256%,Treadmill+167%. Protein Carbonyls were increased IPE in CF only (+5%, while a time-dependent decrease occurred 1-HP (CrossFit™=−16%,Treadmill=−8% and 2-HP (CF=−16%,TM=−1% compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit™ and Treadmill: IPE (CrossFit™=+25%,Treadmill=+17%, 1-HP (CrossFit™=+26%,Treadmill=+4.8%, 2-HP (CrossFit™=+20%,Treadmill=+12%. Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit™= −10%,Treadmill=−12%, 1-HP (CrossFit™= −12%,Treadmill=−6%, 2-HP (CrossFit™= −7%,Treadmill=−11%. No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit™ bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses.

Acute Exercise and Oxidative Stress: CrossFit™ vs. Treadmill Bout

Science.gov (United States)

Kliszczewicz, Brian; Quindry, C. John; Blessing, L. Daniel; Oliver, D. Gretchen; Esco, R. Michael; Taylor, J. Kyle

2015-01-01

CrossFit™, a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit™ bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit™ experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit™ and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit™=+143%, Treadmill=+115%) and 2-HP (CrossFit™=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit™=−16%, Treadmill=−8%) and 2-HP (CF=−16%, TM=−1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit™ and Treadmill: IPE (CrossFit™=+25%, Treadmill=+17%), 1-HP (CrossFit™=+26%, Treadmill=+4.8%), 2-HP (CrossFit™=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit™=−10%, Treadmill=−12%), 1-HP (CrossFit™=−12%, Treadmill=−6%), 2-HP (CrossFit™=−7%, Treadmill=−11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit™ bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses. PMID:26557192

The Effect of Exercise-Induced Muscle Damage After a Bout of Accentuated Eccentric Load Drop Jumps and the Repeated Bout Effect.

Science.gov (United States)

Bridgeman, Lee A; Gill, Nicholas D; Dulson, Deborah K; McGuigan, Michael R

2017-02-01

Bridgeman, LA, Gill, ND, Dulson, DK, and McGuigan, MR. The effect of exercise induced muscle damage after a bout of accentuated eccentric load drop jumps and the repeated bout effect. J Strength Cond Res 31(2): 386-394, 2017-Although previous studies have investigated exercise-induced muscle damage (EIMD) after a bout of unloaded drop jumps (DJs), none have investigated the effects of accentuated eccentric load (AEL) DJs on EIMD. The purpose of this study was to investigate the effects of 30 and 50 AEL DJs on strength, jump performance, muscle soreness, and blood markers. Eight resistance trained athletes participated in this study. In week 1, baseline countermovement jump (CMJ), squat jump (SJ), concentric and eccentric peak force (PF), creatine kinase, and muscle soreness were assessed. Subjects then completed 30 AEL DJs and baseline measures were retested immediately postintervention, 1, 24, and 48 hours later. Two weeks later, the subjects completed the same protocol with an increase in AEL DJ volume (50). Subjects' SJ height was reduced in week 1 compared with week 3, postintervention, 1, 24, and 48 hours later (ES = -0.34, -0.44, -0.38, and -0.40). Subjects' CMJ height was reduced in week 1 compared with week 3, postintervention, 1, and 24 hours later (ES = -0.37, -0.29, and -0.39). Concentric PF was reduced in week 1 compared with week 3, postintervention and 24 and 48 hours later (ES = -0.02, -0.23, and -0.32). Eccentric PF was reduced in week 1 compared with week 3, postintervention, 24, and 48 hours later (ES = -0.24, -0.16, and -0.50). In this sample, 30 AEL DJs attenuated the effects of EIMD following which 50 AEL DJs completed 2 weeks later.

Duration of high-dose aspirin therapy does not affect long-term coronary artery outcomes in Kawasaki disease.

Science.gov (United States)

Migally, Karl; Braunlin, Elizabeth A; Zhang, Lei; Binstadt, Bryce A

2018-05-02

BackgroundHigh-dose aspirin (HDA) is used with intravenous immunoglobulin (IVIg) in Kawasaki disease (KD). Practice regarding HDA varies, and it is unclear whether HDA duration affects the long-term course.MethodsWe retrospectively studied KD patients at our hospital for over 10 years. Patients were categorized as having received HDA for 0, 1-7, or >7 days. Primary outcome was the maximum coronary Z-score at diagnosis and follow-up; secondary outcomes included inflammatory markers.ResultsOne hundred and three patients had HDA duration documented, of which 35 patients had coronary artery abnormalities (CAAs) at diagnosis. There was no difference in demographics or inflammatory markers between the HDA groups, and no difference in HDA duration between patients with or without CAAs. Seventeen patients received no HDA; they had longer illness and defervescence duration before diagnosis, and were less likely to receive IVIg. For CAAs, multivariate regression revealed that HDA duration did not predict the coronary Z-score at 9-15 months. Higher Z-score at diagnosis was associated with higher Z-score at 9-15 months.ConclusionThe only factor associated with coronary Z-score at 9-15 months was the Z-score at diagnosis. At our institution, longer illness and defervescence duration and the lack of IVIg administration were associated with not administering HDA. HDA duration did not affect the clinically relevant outcomes, particularly CAA persistence.Pediatric Research advance online publication, 2 May 2018; doi:10.1038/pr.2018.44.

Out of mind, out of heart: attention affects duration of emotional experience.

Science.gov (United States)

Freund, Alexandra M; Keil, Andreas

2013-01-01

It has been suggested that the extent to which a person maintains attention to pleasant versus unpleasant aspects of a given stimulus has an effect on the self-reported affective state. This assumption was empirically tested in two experiments. In Study 1, participants received the instruction either to focus on a positive emotion-eliciting event (winning a tournament chess game) or to focus their attention on an affectively neutral distraction task (describing drawings). Study 2 used negative performance feedback in a cognitive task to induce unpleasant affect and included three experimental groups (waiting condition, continuing with the same cognitive task, distraction by a different cognitive task). Results converged to show that distracting attention away from the emotion-eliciting event leads to a shorter duration of the emotional experience. These findings support the attention-focus hypothesis.

The effects of a mid-morning bout of exercise on adolescents' cognitive function

OpenAIRE

Cooper, SB; Bandelow, S; Nute, ML; Morris, JG; Nevill, ME

2012-01-01

The aim of the present study was to examine the effects of a mid-morning bout of exercise on adolescents’ cognitive function in a randomised crossover design where each participant completed two experimental trials. Forty-five adolescents (13.3±0.3 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test, 30s rest between repeats; exercise trial) or continued to rest (resting trial). A battery of cognitive function tests assessing visuo-motor speed, e...

The repeated bout effect of typical lower body strength training sessions on sub-maximal running performance and hormonal response.

Science.gov (United States)

Doma, Kenji; Schumann, Moritz; Sinclair, Wade H; Leicht, Anthony S; Deakin, Glen B; Häkkinen, Keijo

2015-08-01

This study examined the effects of two typical strength training sessions performed 1 week apart (i.e. repeated bout effect) on sub-maximal running performance and hormonal. Fourteen resistance-untrained men (age 24.0 ± 3.9 years; height 1.83 ± 0.11 m; body mass 77.4 ± 14.0 kg; VOpeak 48.1 ± 6.1 M kg(-1) min(-1)) undertook two bouts of high-intensity strength training sessions (i.e. six-repetition maximum). Creatine kinase (CK), delayed-onset muscle soreness (DOMS), counter-movement jump (CMJ) as well as concentrations of serum testosterone, cortisol and testosterone/cortisol ratio (T/C) were examined prior to and immediately post, 24 (T24) and 48 (T48) h post each strength training bout. Sub-maximal running performance was also conducted at T24 and T48 of each bout. When measures were compared between bouts at T48, the degree of elevation in CK (-58.4 ± 55.6 %) and DOMS (-31.43 ± 42.9 %) and acute reduction in CMJ measures (4.1 ± 5.4 %) were attenuated (p 0.05). Sub-maximal running performance was impaired until T24, although changes were not attenuated following the second bout. The initial bout appeared to provide protection against a number of muscle damage indicators suggesting a greater need for recovery following the initial session of typical lower body resistance exercises in resistance-untrained men although sub-maximal running should be avoided following the first two sessions.

acute and session rPe responses during resistance training: Bouts ...

African Journals Online (AJOL)

tive measure of aerobic exercise intensity. While correlating well ... ing intensity in aerobic-type exercise. 7 ... While original work dealt with RPE during an exercise bout, ..... Borg G. Perceived exertion as an indicator of somatic stress. Scan J.

Benchmark studies of BOUT++ code and TPSMBI code on neutral transport during SMBI

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.H. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Z.H., E-mail: zhwang@swip.ac.cn [Southwestern Institute of Physics, Chengdu 610041 (China); Guo, W., E-mail: wfguo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Ren, Q.L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Sun, A.P.; Xu, M.; Wang, A.K. [Southwestern Institute of Physics, Chengdu 610041 (China); Xiang, N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China)

2017-06-09

SMBI (supersonic molecule beam injection) plays an important role in tokamak plasma fuelling, density control and ELM mitigation in magnetic confinement plasma physics, which has been widely used in many tokamaks. The trans-neut module of BOUT++ code is the only large-scale parallel 3D fluid code used to simulate the SMBI fueling process, while the TPSMBI (transport of supersonic molecule beam injection) code is a recent developed 1D fluid code of SMBI. In order to find a method to increase SMBI fueling efficiency in H-mode plasma, especially for ITER, it is significant to first verify the codes. The benchmark study between the trans-neut module of BOUT++ code and the TPSMBI code on radial transport dynamics of neutral during SMBI has been first successfully achieved in both slab and cylindrical coordinates. The simulation results from the trans-neut module of BOUT++ code and TPSMBI code are consistent very well with each other. Different upwind schemes have been compared to deal with the sharp gradient front region during the inward propagation of SMBI for the code stability. The influence of the WENO3 (weighted essentially non-oscillatory) and the third order upwind schemes on the benchmark results has also been discussed. - Highlights: • A 1D model of SMBI has developed. • Benchmarks of BOUT++ and TPSMBI codes have first been finished. • The influence of the WENO3 and the third order upwind schemes on the benchmark results has also been discussed.

Mixtures of beta distributions in models of the duration of a project affected by risk

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Gładysz, Barbara; Kuchta, Dorota

2017-07-01

This article presents a method for timetabling a project affected by risk. The times required to carry out tasks are modelled using mixtures of beta distributions. The parameters of these beta distributions are given by experts: one corresponding to the duration of a task in stable conditions, with no risks materializing, and the other corresponding to the duration of a task in the case when risks do occur. Finally, a case study will be presented and analysed: the project of constructing a shopping mall in Poland.

Comparing the effects of an acute bout of physical exercise with an acute bout of interactive mental and physical exercise on electrophysiology and executive functioning in younger and older adults.

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Dimitrova, Julia; Hogan, Michael; Khader, Patrick; O'Hora, Denis; Kilmartin, Liam; Walsh, Jane C; Roche, Richard; Anderson-Hanley, Cay

2017-10-01

Physical exercise has been shown to improve cognitive and neural functioning in older adults. The current study compared the effects of an acute bout of physical exercise with a bout of interactive mental and physical exercise (i.e., "exergaming") on executive (Stroop) task performance and event-related potential (ERP) amplitudes in younger and older adults. Results revealed enhanced executive task performance in younger and older adults after exercise, with no differences in performance between exercise conditions. Stroop (RT) performance in older adults improved more than in younger adults from pre- to post-exercise. A significant increase in EEG amplitude from pre- to post-exercise was found at the Cz site from 320 to 700 ms post-stimulus for both younger and older adults, with older adults demonstrating a larger Stroop interference effect. While younger adults exhibited overall greater EEG amplitudes than older adults, they showed no differences between congruent and incongruent trials (i.e., minimal interference). Compared to peers with higher BMI (body mass index), older adults with lower BMI showed a greater reduction in Stroop interference effects from pre- to post-exercise. The beneficial effects of an acute bout of physical exercise on cognitive and neural functioning in younger and older adults were confirmed, with no difference between standard exercise and exergaming. Findings suggest that BMI, sometimes used as a proxy for fitness level, may modulate benefits that older adults derive from an acute bout of exercise. Findings have implications for future research that seeks to investigate unique effects of exergaming when compared to standard physical exercise.

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study

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Felix Kaspar

2016-01-01

Full Text Available Objective. This study compared acute and late effect of single-bout endurance training (ET and high-intensity interval training (HIIT on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Design. Cohort study with repeated-measures design. Methods. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL, IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1, insulin growth factor 1 (IGF-1, and C-reactive protein (CRP. Statistical analysis was with Wilcoxon signed-rank tests. Results. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (−20%; p=0.047 and a decrease of MCP-1 (−17.9%; p=0.03. Conclusion. This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis.

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study

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Kaspar, Felix; Jelinek, Herbert F.; Perkins, Steven; Al-Aubaidy, Hayder A.; deJong, Bev; Butkowski, Eugene

2016-01-01

Objective. This study compared acute and late effect of single-bout endurance training (ET) and high-intensity interval training (HIIT) on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Design. Cohort study with repeated-measures design. Methods. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL), IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1), insulin growth factor 1 (IGF-1), and C-reactive protein (CRP). Statistical analysis was with Wilcoxon signed-rank tests. Results. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (−20%; p = 0.047) and a decrease of MCP-1 (−17.9%; p = 0.03). Conclusion. This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis. PMID:27212809

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study.

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Kaspar, Felix; Jelinek, Herbert F; Perkins, Steven; Al-Aubaidy, Hayder A; deJong, Bev; Butkowski, Eugene

2016-01-01

This study compared acute and late effect of single-bout endurance training (ET) and high-intensity interval training (HIIT) on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Cohort study with repeated-measures design. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL), IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1), insulin growth factor 1 (IGF-1), and C-reactive protein (CRP). Statistical analysis was with Wilcoxon signed-rank tests. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (-20%; p = 0.047) and a decrease of MCP-1 (-17.9%; p = 0.03). This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis.

The effect of exercise on affective and self-efficacy responses in older and younger women.

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Barnett, Fiona

2013-01-01

This study examined the self-efficacy and affective responses to an acute exercise bout in sedentary older and younger women to determine whether aging has an effect on affective states. Twenty-five sedentary younger (mean age = 19.9 yrs) and 25 older (mean age = 55.7 yrs) women completed an acute bout of exercise. Affective responses were measured before, during, and immediately following exercise. Self-efficacy responses were measured before and immediately following exercise. Positive engagement, revitalization, tranquility, Felt Arousal and Feeling Scale responses, and self-efficacy were all higher immediately following compared with before or during exercise for both groups of women. In addition, older women experienced higher overall positive engagement and lower physical exhaustion compared with younger women as well as higher tranquility and Feeling Scale responses immediately following exercise. This investigation found that an acute bout of moderate-intensity exercise produced more positive and fewer negative affective states in both younger and older women.

Acute Exercise and Oxidative Stress: CrossFit(™) vs. Treadmill Bout.

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Kliszczewicz, Brian; Quindry, C John; Blessing, L Daniel; Oliver, D Gretchen; Esco, R Michael; Taylor, J Kyle

2015-09-29

CrossFit(™), a popular high-intensity training modality, has been the subject of scrutiny, with concerns of elevated risk of injury and health. Despite these concerns empirical evidence regarding physiologic stresses including acute oxidative stress is lacking. Therefore, the purpose of this investigation was to examine the acute redox response to a CrossFit(™) bout. Furthermore, these findings were compared to a high-intensity treadmill bout as a point of reference. Ten males 26.4 ± 2.7 yrs having three or more months of CrossFit(™) experience participated in the present study. Blood plasma was collected at four time points: Pre-exercise (PRE), immediately-post-exercise (IPE), 1 hr-post (1-HP) and 2 hr-post (2-HP), to examine oxidative damage and antioxidant capacity. Regarding plasma oxidative damage, CrossFit(™) and Treadmill elicited a time-dependent increase of lipid peroxides 1-HP (CrossFit(™)=+143%, Treadmill=+115%) and 2-HP (CrossFit(™)=+256%, Treadmill+167%). Protein Carbonyls were increased IPE in CF only (+5%), while a time-dependent decrease occurred 1-HP (CrossFit(™)=-16%, Treadmill=-8%) and 2-HP (CF=-16%, TM=-1%) compared to IPE. Regarding antioxidant capacity, Ferric Reducing Antioxidant Power also demonstrated a time-dependent increase within CrossFit(™) and Treadmill: IPE (CrossFit(™)=+25%, Treadmill=+17%), 1-HP (CrossFit(™)=+26%, Treadmill=+4.8%), 2-HP (CrossFit(™)=+20%, Treadmill=+12%). Total Enzymatic Antioxidant Capacity showed a time-dependent decrease in IPE (CrossFit(™)=-10%, Treadmill=-12%), 1-HP (CrossFit(™)=-12%, Treadmill=-6%), 2-HP (CrossFit(™)=-7%, Treadmill=-11%). No trial-dependent differences were observed in any biomarker of oxidative stress. The CrossFit(™) bout elicited an acute blood oxidative stress response comparable to a traditional bout of high-intensity treadmill running. Results also confirm that exercise intensity and the time course of exercise recovery influence oxidative responses.

Acute bouts of wheel running decrease cocaine self-administration: Influence of exercise output.

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Smith, Mark A; Fronk, Gaylen E; Zhang, Huailin; Magee, Charlotte P; Robinson, Andrea M

Exercise is associated with lower rates of drug use in human populations and decreases drug self-administration in laboratory animals. Most of the existing literature examining the link between exercise and drug use has focused on chronic, long-term exercise, and very few studies have examined the link between exercise output (i.e., amount of exercise) and drug self-administration. The purpose of this study was to examine the effects of acute bouts of exercise on cocaine self-administration, and to determine whether these effects were dependent on exercise output and the time interval between exercise and drug self-administration. Female rats were trained to run in automated running wheels, implanted with intravenous catheters, and allowed to self-administer cocaine on a fixed ratio (FR1) schedule of reinforcement. Immediately prior to each test session, subjects engaged in acute bouts of exercise in which they ran for 0, 30, or 60min at 12m/min. Acute bouts of exercise before test sessions decreased cocaine self-administration in an output-dependent manner, with the greatest reduction in cocaine intake observed in the 60-min exercise condition. Exercise did not reduce cocaine self-administration when wheel running and test sessions were separated by 12h, and exercise did not reduce responding maintained by food or responding during a saline substitution test. These data indicate that acute bouts of exercise decrease cocaine self-administration in a time- and output-dependent manner. These results also add to a growing body of literature suggesting that physical activity may be an effective component of drug abuse treatment programs. Copyright © 2016 Elsevier Inc. All rights reserved.

Linear calculations of edge current driven kink modes with BOUT++ code

Energy Technology Data Exchange (ETDEWEB)

Li, G. Q., E-mail: ligq@ipp.ac.cn; Xia, T. Y. [Institute of Plasma Physics, CAS, Hefei, Anhui 230031 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Snyder, P. B.; Turnbull, A. D. [General Atomics, San Diego, California 92186 (United States); Ma, C. H.; Xi, P. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); FSC, School of Physics, Peking University, Beijing 100871 (China)

2014-10-15

This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density.

Linear calculations of edge current driven kink modes with BOUT++ code

International Nuclear Information System (INIS)

Li, G. Q.; Xia, T. Y.; Xu, X. Q.; Snyder, P. B.; Turnbull, A. D.; Ma, C. H.; Xi, P. W.

2014-01-01

This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density

Vertical Finger Displacement Is Reduced in Index Finger Tapping During Repeated Bout Rate Enhancement.

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Mora-Jensen, Mark Holten; Madeleine, Pascal; Hansen, Ernst Albin

2017-10-01

The present study analyzed (a) whether a recently reported phenomenon of repeated bout rate enhancement in finger tapping (i.e., a cumulating increase in freely chosen finger tapping frequency following submaximal muscle activation in the form of externally unloaded voluntary tapping) could be replicated and (b) the hypotheses that the faster tapping was accompanied by changed vertical displacement of the fingertip and changed peak force during tapping. Right-handed, healthy, and recreationally active individuals (n = 24) performed two 3-min index finger tapping bouts at freely chosen tapping frequency, separated by 10-min rest. The recently reported phenomenon of repeated bout rate enhancement was replicated. The faster tapping (8.8 ± 18.7 taps/min, corresponding to 6.0 ± 11.0%, p = .033) was accompanied by reduced vertical displacement (1.6 ± 2.9 mm, corresponding to 6.3 ± 14.9%, p = .012) of the fingertip. Concurrently, peak force was unchanged. The present study points at separate control mechanisms governing kinematics and kinetics during finger tapping.

The effects of acute bout of cycling on auditory & visual reaction times.

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Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

2015-04-01

The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

One bout of open skill exercise improves cross-modal perception and immediate memory in healthy older adults who habitually exercise.

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O'Brien, Jessica; Ottoboni, Giovanni; Tessari, Alessia; Setti, Annalisa

2017-01-01

One single bout of exercise can be associated with positive effects on cognition, due to physiological changes associated with muscular activity, increased arousal, and training of cognitive skills during exercise. While the positive effects of life-long physical activity on cognitive ageing are well demonstrated, it is not well established whether one bout of exercise is sufficient to register such benefits in older adults. The aim of this study was to test the effect of one bout of exercise on two cognitive processes essential to daily life and known to decline with ageing: audio-visual perception and immediate memory. Fifty-eight older adults took part in a quasi-experimental design study and were divided into three groups based on their habitual activity (open skill exercise (mean age = 69.65, SD = 5.64), closed skill exercise, N = 18, 94% female; sedentary activity-control group, N = 21, 62% female). They were then tested before and after their activity (duration between 60 and 80 minutes). Results showed improvement in sensitivity in audio-visual perception in the open skill group and improvements in one of the measures of immediate memory in both exercise groups, after controlling for baseline differences including global cognition and health. These findings indicate that immediate benefits for cross-modal perception and memory can be obtained after open skill exercise. However, improvements after closed skill exercise may be limited to memory benefits. Perceptual benefits are likely to be associated with arousal, while memory benefits may be due to the training effects provided by task requirements during exercise. The respective role of qualitative and quantitative differences between these activities in terms of immediate cognitive benefits should be further investigated. Importantly, the present results present the first evidence for a modulation of cross-modal perception by exercise, providing a plausible avenue for rehabilitation of cross

One bout of open skill exercise improves cross-modal perception and immediate memory in healthy older adults who habitually exercise.

Directory of Open Access Journals (Sweden)

Jessica O'Brien

Full Text Available One single bout of exercise can be associated with positive effects on cognition, due to physiological changes associated with muscular activity, increased arousal, and training of cognitive skills during exercise. While the positive effects of life-long physical activity on cognitive ageing are well demonstrated, it is not well established whether one bout of exercise is sufficient to register such benefits in older adults. The aim of this study was to test the effect of one bout of exercise on two cognitive processes essential to daily life and known to decline with ageing: audio-visual perception and immediate memory. Fifty-eight older adults took part in a quasi-experimental design study and were divided into three groups based on their habitual activity (open skill exercise (mean age = 69.65, SD = 5.64, closed skill exercise, N = 18, 94% female; sedentary activity-control group, N = 21, 62% female. They were then tested before and after their activity (duration between 60 and 80 minutes. Results showed improvement in sensitivity in audio-visual perception in the open skill group and improvements in one of the measures of immediate memory in both exercise groups, after controlling for baseline differences including global cognition and health. These findings indicate that immediate benefits for cross-modal perception and memory can be obtained after open skill exercise. However, improvements after closed skill exercise may be limited to memory benefits. Perceptual benefits are likely to be associated with arousal, while memory benefits may be due to the training effects provided by task requirements during exercise. The respective role of qualitative and quantitative differences between these activities in terms of immediate cognitive benefits should be further investigated. Importantly, the present results present the first evidence for a modulation of cross-modal perception by exercise, providing a plausible avenue for rehabilitation of

Physiological profile of a professional boxer preparing for Title Bout: A case study.

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Halperin, Israel; Hughes, Steven; Chapman, Dale W

2016-10-01

This study aimed to (1) profile a professional boxer (23 years and 80 kg) with boxing-specific, muscle function, aerobic capacity and body composition tests, and (2) quantify how these measures varied during an 8-week preparation phase leading to, and post a state-Title Bout fought in the 76.2-kg class. A series of boxing-specific and muscle function tests were completed on 11 occasions: 9 prior and twice after the bout, each separated by approximately 2 weeks. The boxing test included 36 maximal punches (9 of each: lead and rear straights, lead and rear hooks) to a punching integrator measuring forces and velocity. Muscle function tests included countermovement jump, drop-jumps, isometric mid-thigh pull and isometric bench-press. Body composition was assessed using skin-fold measurements on three occasions and one dual energy X-ray absorptiometry scan. Aerobic capacity was assessed using 2 VO2 max tests. Leading up to the bout, performance decreased in isometric mid-thigh pull (8%), isometric bench-press (5%), countermovement jump (15%) and impact forces in 3 of 4 punches (4%-7%). Whereas measures of dynamic and isometric muscle function remained depressed or unchanged post competition, punching forces (6%-15%) and aerobic power (6%) increased. Data suggest the athlete may have super-compensated following rest as fatigue dissipated and further adaptation occurred.

Associations between physical activity, sedentary time, sleep duration and daytime sleepiness in US adults.

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McClain, James J; Lewin, Daniel S; Laposky, Aaron D; Kahle, Lisa; Berrigan, David

2014-09-01

To examine the associations between objectively measured physical activity (PA) or sedentary behavior and self-reported sleep duration or daytime sleepiness in a nationally representative sample of healthy US adults (N=2128). We report analyses of four aspects of sedentary behavior and PA derived from accelerometry data (minutes of sedentary time, activity counts/minute, Minutes of Moderate and Vigorous PA [MVPA], and MVPA in 10-minute bouts) versus self-report of sleep duration and frequency of daytime sleepiness from the 2005-2006 National Health and Nutrition Examination Survey. Age and sex dependence of associations between PA and sleep were observed. Aspects of PA were significantly lower in adults reporting more frequent daytime sleepiness in younger (20-39) and older (≥ 60) age groups, but not in middle-aged (40-59), respondents. In younger respondents, PA increased with sleep duration, but in middle aged and older respondents PA was either unrelated to sleep duration or lower in those reporting ≥ 8 h of sleep. Objectively measured sedentary time showed limited evidence of associations with sleep duration. Further research delineating the relationships between sleep and PA is important because both activities have been implicated in diverse health outcomes as well as in the etiology of obesity. Published by Elsevier Inc.

Increased CSF levels of phosphorylated neurofilament heavy protein following bout in amateur boxers.

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Sanna Neselius

Full Text Available INTRODUCTION: Diagnosis of mild TBI is hampered by the lack of imaging or biochemical measurements for identifying or quantifying mild TBI in a clinical setting. We have previously shown increased biomarker levels of protein reflecting axonal (neurofilament light protein and tau and glial (GFAP and S-100B damage in cerebrospinal fluid (CSF after a boxing bout. The aims of this study were to find other biomarkers of mild TBI, which may help clinicians diagnose and monitor mild TBI, and to calculate the role of APOE ε4 allele genotype which has been associated with poor outcome after TBI. MATERIALS AND METHODS: Thirty amateur boxers with a minimum of 45 bouts and 25 non-boxing matched controls were included in a prospective cohort study. CSF and blood were collected at one occasion between 1 and 6 days after a bout, and after a rest period for at least 14 days (follow up. The controls were tested once. CSF levels of neurofilament heavy (pNFH, amyloid precursor proteins (sAPPα and sAPPβ, ApoE and ApoA1 were analyzed. In blood, plasma levels of Aβ42 and ApoE genotype were analyzed. RESULTS: CSF levels of pNFH were significantly increased between 1 and 6 days after boxing as compared with controls (p<0.001. The concentrations decreased at follow up but were still significantly increased compared to controls (p = 0.018. CSF pNFH concentrations correlated with NFL (r =  0.57 after bout and 0.64 at follow up, p<0.001. No significant change was found in the other biomarkers, as compared to controls. Boxers carrying the APOE ε4 allele had similar biomarker concentrations as non-carriers. CONCLUSIONS: Subconcussive repetitive trauma in amateur boxing causes a mild TBI that may be diagnosed by CSF analysis of pNFH, even without unconsciousness or concussion symptoms. Possession of the APOE ε4 allele was not found to influence biomarker levels after acute TBI.

Locomotion Mode Affects the Physiological Strain during Exercise at Walk-Run Transition Speed inElderly Men.

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Freire, Raul; Farinatti, Paulo; Cunha, Felipe; Silva, Brenno; Monteiro, Walace

2017-07-01

This study investigated cardiorespiratory responses and rating of perceived exertion (RPE) during prolonged walking and running exercise performed at the walk-run transition speed (WRTS) in untrained healthy elderly men. 20 volunteers (mean±SE, age: 68.4±1.2 yrs; height: 170.0±0.02 cm; body mass: 74.7±2.3 kg) performed the following bouts of exercise: a) maximal cardiopulmonary exercise test (CPET); b) specific protocol to detect WRTS; and c) two 30-min walking and running bouts at WRTS. Expired gases were collected during exercise bouts via the Ultima CardiO 2 metabolic analyzer. Compared to walking, running at the WRTS resulted in higher oxygen uptake (>0.27 L·min -1 ), pulmonary ventilation (>7.7 L·min -1 ), carbon dioxide output (>0.23 L·min -1 ), heart rate (>15 beats·min -1 ), oxygen pulse (>0.88 15 mL·beats -1 ), energy expenditure (>27 kcal) and cost of oxygen transport (>43 mL·kg -1 ·km -1 ·bout -1 ). The increase of overall and local RPEs with exercise duration was similar across locomotion modes (Pexercise tolerance. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of Intermittent Neck Cooling During Repeated Bouts of High-Intensity Exercise

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Andrew J. Galpin

2016-06-01

Full Text Available The purpose of this investigation was to determine the influence of intermittent neck cooling during exercise bouts designed to mimic combat sport competitions. Participants (n = 13, age = 25.3 ± 5.0 year height = 176.9 ± 7.5 cm, mass = 79.3 ± 9.0 kg, body fat = 11.8% ± 3.1% performed three trials on a cycle ergometer. Each trial consisted of two, 5-min high-intensity exercise (HEX intervals (HEX1 and HEX2—20 s at 50% peak power, followed by 15 s of rest, and a time to exhaustion (TTE test. One-minute rest intervals were given between each round (RI1 and RI2, during which researchers treated the participant’s posterior neck with either (1 wet-ice (ICE; (2 menthol spray (SPRAY; or (3 no treatment (CON. Neck (TNECK and chest (TCHEST skin temperatures were significantly lower following RI1 with ICE (vs. SPRAY. Thermal sensation decreased with ICE compared to CON following RI1, RI2, TTE, and a 2-min recovery. Rating of perceived exertion was also lower with ICE following HEX2 (vs. CON and after RI2 (vs. SPRAY. Treatment did not influence TTE (68.9 ± 18.9s. The ability of intermittent ICE to attenuate neck and chest skin temperature rises during the initial HEX stages likely explains why participants felt cooler and less exerted during equivalent HEX bouts. These data suggest intermittent ICE improves perceptual stress during short, repeated bouts of vigorous exercise.

Sexual conflict over parental investment in repeated bouts: negotiation reduces overall care

NARCIS (Netherlands)

Lessells, C.M.; McNamara, J.M.

2012-01-01

Understanding the evolution of parental care is complicated by the occurrence of evolutionary conflicts of interest within the family, variation in the quality and state of family members, and repeated bouts of investment in a family of offspring. As a result, family members are expected to

What Is the Effect on Obesity Indicators from Replacing Prolonged Sedentary Time with Brief Sedentary Bouts, Standing and Different Types of Physical Activity during Working Days?

DEFF Research Database (Denmark)

Gupta, Nidhi; Heiden, Marina; Aadahl, Mette

2016-01-01

) across the day during work period and 5.5 hours (~62% of the measured time, SD = 1.5 hours) during non-work period. Most of the sedentary time was accrued in moderate bouts [work = 1.40 (SD = 1.09) hours] during work and in long bouts during non-work [2.7 (SD = 1.4) hours], while least in long sedentary...... bouts during work [work = 0.5 (SD = 0.9)] and in brief sedentary bouts [0.5 hours (SD = 0.3)] during non-work. Significant associations with all obesity indicators were found when 30 min of total sedentary time or long sedentary bouts were replaced with standing time (~1–2% lower) or MVPA (~4–9% lower...... physical activity (MVPA) time on working days was computed using validated Acti4 software. The total sedentary time and uninterrupted sedentary time spent in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) bouts, were determined for the whole day and during work and non-work time separately...

Influence of acute exercise of varying intensity and duration on postprandial oxidative stress.

Science.gov (United States)

Canale, Robert E; Farney, Tyler M; McCarthy, Cameron G; Bloomer, Richard J

2014-09-01

Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal. To compare the impact of acute exercise on postprandial oxidative stress. We compared aerobic and anaerobic exercise bouts of different intensities and durations on postprandial blood triglycerides (TAG), oxidative stress biomarkers (malondialdehyde, hydrogen peroxide, advanced oxidation protein products), and antioxidant status (trolox equivalent antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase). Twelve trained men (21-35 years) underwent four conditions: (1) No exercise rest; (2) 60-min aerobic exercise at 70% heart rate reserve; (3) five 60-s sprints at 100% max capacity; and (4) ten 15-s sprints at 200% max capacity. All exercise bouts were performed on a cycle ergometer. A high-fat meal was consumed 1 h after exercise cessation. Blood samples were collected pre-meal and 2 and 4 h post-meal and analyzed for TAG, oxidative stress biomarkers, and antioxidant status. No significant interaction or condition effects were noted for any variable (p > 0.05), with acute exercise having little to no effect on the magnitude of postprandial oxidative stress. In a sample of healthy, well-trained men, neither aerobic nor anaerobic exercise attenuates postprandial oxidative stress in response to a high-fat meal.

Does exercise motivation predict engagement in objectively assessed bouts of moderate-intensity exercise? A self-determination theory perspective.

Science.gov (United States)

Standage, Martyn; Sebire, Simon J; Loney, Tom

2008-08-01

This study examined the utility of motivation as advanced by self-determination theory (Deci & Ryan, 2000) in predicting objectively assessed bouts of moderate intensity exercise behavior. Participants provided data pertaining to their exercise motivation. One week later, participants wore a combined accelerometer and heart rate monitor (Actiheart; Cambridge Neurotechnology Ltd) and 24-hr energy expenditure was estimated for 7 days. After controlling for gender and a combined marker of BMI and waist circumference, results showed autonomous motivation to positively predict moderate-intensity exercise bouts of >or=10 min, or=20 min, and an accumulation needed to meet public health recommendations for moderate intensity activity (i.e., ACSM/AHA guidelines). The present findings add bouts of objectively assessed exercise behavior to the growing body of literature that documents the adaptive consequences of engaging in exercise for autonomous reasons. Implications for practice and future work are discussed.

Conditioned pain modulation is affected by occlusion cuff conditioning stimulus intensity, but not duration.

Science.gov (United States)

Smith, A; Pedler, A

2018-01-01

Various conditioned pain modulation (CPM) methodologies have been used to investigate diffuse noxious inhibitory control pain mechanisms in healthy and clinical populations. Occlusion cuff parameters have been poorly studied. We aimed to investigate whether occlusion cuff intensity and/or duration influenced CPM magnitudes. We also investigated the role of physical activity levels on CPM magnitude. Two studies were performed to investigate the role of intensity and duration of occlusion cuff conditioning stimulus on test stimulus (tibialis anterior pressure pain thresholds). In Study 1, conditioning stimulus intensity of 2/10 or 5/10 (duration CPM magnitude. In Study 1, 27 healthy volunteers (mean ± SD: 24.9 years (±4.5); eight female) demonstrated that an occlusion cuff applied to the upper arm eliciting 5/10 local pain resulted in a significant (mean ± SD: 17% ± 46%) increase in CPM magnitude, when compared to 2/10 intensity (-3% ± 38%, p = 0.026), whereas in Study 2, 25 healthy volunteers (22.5 years (±2.7); 13 female) demonstrated that 3 min of 2/10 CS intensity did not result in a significant change in CPM (p = 0.21). There was no significant relationship between physical activity levels and CPM in either study (p > 0.22). This study demonstrated that an occlusion cuff of 5/10 conditioning stimulus intensity, when compared to 2/10, significantly increased CPM magnitude. Maintaining 2/10 conditioning stimulus for 3 min did not increase CPM magnitude. Dysfunctional conditioned pain modulation (CPM) has been associated with poor health outcomes. Various factors can influence CPM outcomes. The role of occlusion cuff conditioning stimulus intensity and duration has not been previously investigated. Intensity (5/10), but not duration of lower intensity (2/10) conditioning stimulus, affects CPM magnitude. © 2017 European Pain Federation - EFIC®.

The repeated-bout effect: influence on biceps brachii oxygenation and myoelectrical activity.

Science.gov (United States)

Muthalib, Makii; Lee, Hoseong; Millet, Guillaume Y; Ferrari, Marco; Nosaka, Kazunori

2011-05-01

This study investigated biceps brachii oxygenation and myoelectrical activity during and following maximal eccentric exercise to better understand the repeated-bout effect. Ten men performed two bouts of eccentric exercise (ECC1, ECC2), consisting of 10 sets of 6 maximal lengthening contractions of the elbow flexors separated by 4 wk. Tissue oxygenation index minimum amplitude (TOI(min)), mean and maximum total hemoglobin volume by near-infrared spectroscopy, torque, and surface electromyography root mean square (EMG(RMS)) during exercise were compared between ECC1 and ECC2. Changes in maximal voluntary isometric contraction (MVC) torque, range of motion, plasma creatine kinase activity, muscle soreness, TOI(min), and EMG(RMS) during sustained (10-s) and 30-repeated isometric contraction tasks at 30% (same absolute force) and 100% MVC (same relative force) for 4 days postexercise were compared between ECC1 and ECC2. No significant differences between ECC1 and ECC2 were evident for changes in torque, TOI(min), mean total hemoglobin volume, maximum total hemoglobin volume, and EMG(RMS) during exercise. Smaller (P < 0.05) changes and faster recovery of muscle damage markers were evident following ECC2 than ECC1. During 30% MVC tasks, TOI(min) did not change, but EMG(RMS) increased 1-4 days following ECC1 and ECC2. During 100% MVC tasks, EMG(RMS) did not change, but torque and TOI(min) decreased 1-4 days following ECC1 and ECC2. TOI(min) during 100% MVC tasks and EMG(RMS) during 30% MVC tasks recovered faster (P < 0.05) following ECC2 than ECC1. We conclude that the repeated-bout effect cannot be explained by altered muscle activation or metabolic/hemodynamic changes, and the faster recovery in muscle oxygenation and activation was mainly due to faster recovery of force.

Factors Affecting the Neonatal Intensive Care Unit Stay Duration in Very Low Birth Weight Premature Infants

OpenAIRE

Niknajad, Akram; Ghojazadeh, Morteza; Sattarzadeh, Niloufar; Bashar Hashemi, Fazileh; Dezham Khoy Shahgholi, Farid

2012-01-01

Introduction: Improved survival of very low birth weight (VLBW) premature infants requires urgent intensive care, professional nursing and medical care. On the other hand, long hospital stay period imposes emotional and economic burdens on the family and society. Therefore, it is necessary to clarify the most important factors affecting their hospitalization duration to lessen unwanted outcomes of premature birth and to eliminate or relieve the problems. Methods: In a descri...

GABA-Mediated Inactivation of Medial Prefrontal and Agranular Insular Cortex in the Rat: Contrasting Effects on Hunger- and Palatability-Driven Feeding.

Science.gov (United States)

Baldo, Brian A; Spencer, Robert C; Sadeghian, Ken; Mena, Jesus D

2016-03-01

A microanalysis of hunger-driven and palatability-driven feeding was carried out after muscimol-mediated inactivation of two frontal regions in rats, the agranular/dysgranular insular cortex (AIC) and the ventromedial prefrontal cortex (vmPFC). Food and water intake, feeding microstructure, and general motor activity were measured under two motivational conditions: food-deprived rats given standard chow or ad libitum-fed rats given a palatable chocolate shake. Muscimol infusions into the AIC diminished intake, total feeding duration, and average feeding bout duration for the palatable-food condition only but failed to alter exploratory-like behavior (ambulation or rearing). In contrast, intra-vmPFC muscimol infusions did not alter the overall intake of chow or chocolate shake. However, these infusions markedly increased mean feeding bout duration for both food types and produced a modest but significant reduction of exploratory-like behavior. The lengthening of feeding-bout duration and reduction in rearing were mimicked by intra-vmPFC blockade of AMPA-type but not NMDA-type glutamate receptors. Neither water consumption nor the microstructure of water drinking was affected by inactivation of either site. These results indicate a regional heterogeneity in frontal control of feeding behavior. Neural processing in AIC supports palatability-driven feeding but is not necessary for intake of a standard food under a food-restriction condition, whereas ventromedial prefrontal cortex, and AMPA signaling therein, modulates the duration of individual feeding bouts regardless of motivational context. Results are discussed in the context of regionally heterogeneous frontal modulation of two distinct components of feeding behavior: reward valuation based upon taste perception (AIC) vs switching between ingestive and non-ingestive (eg, exploratory-like) behavioral repertoires (vmPFC).

Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle

DEFF Research Database (Denmark)

Coffey, Vernon G; Pilegaard, Henriette; Garnham, Andrew P

2009-01-01

-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (-42%), whereas muscle ring finger...

The effects of single bouts of aerobic exercise, exergaming, and videogame play on cognitive control.

Science.gov (United States)

O'Leary, Kevin C; Pontifex, Matthew B; Scudder, Mark R; Brown, Michael L; Hillman, Charles H

2011-08-01

The effects of single bouts of aerobic exercise, exergaming, and action videogame play on event-related brain potentials (ERPs) and task performance indices of cognitive control were investigated using a modified flanker task that manipulated demands of attentional inhibition. Participants completed four counterbalanced sessions of 20 min of activity intervention (i.e., seated rest, seated videogame play, and treadmill-based and exergame-based aerobic exercise at 60% HR(max)) followed by cognitive testing once heart rate (HR) returned to within 10% of pre-activity levels. Results indicated decreased RT interference following treadmill exercise relative to seated rest and videogame play. P3 amplitude was increased following treadmill exercise relative to rest, suggesting an increased allocation of attentional resources during stimulus engagement. The seated videogame and exergame conditions did not differ from any other condition. The findings indicate that single bouts of treadmill exercise may improve cognitive control through an increase in the allocation of attentional resources and greater interference control during cognitively demanding tasks. However, similar benefits may not be derived following short bouts of aerobic exergaming or seated videogame participation. Although exergames may increase physical activity participation, they may not exert the same benefits to brain and cognition as more traditional physical activity behaviors. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

A single 60-min bout of peristaltic pulse external pneumatic compression transiently upregulates phosphorylated ribosomal protein s6.

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Martin, J S; Kephart, W C; Mobley, C B; Wilson, T J; Goodlett, M D; Roberts, M D

2017-11-01

We investigated whether a single 60-min bout of whole leg, peristaltic pulse external pneumatic compression (EPC) altered select growth factor-related mRNAs and/or various phospho(p)-proteins related to cell growth, proliferation, inflammation and apoptosis signalling (e.g. Akt-mTOR, Jak-Stat). Ten participants (8 males, 2 females; aged 22·2 ± 0·4 years) reported to the laboratory 4 h post-prandial, and vastus lateralis muscle biopsies were obtained prior to (PRE), 1 h and 4 h post-EPC treatment. mRNA expression was analysed using real-time RT-PCR and phosphophorylated and cleaved proteins were analysed using an antibody array. No changes in selected growth factor-related mRNAs were observed following EPC. All p-proteins significantly altered by EPC decreased, except for p-rps6 (Ser235/236) which increased 31% 1 h post-EPC compared to PRE levels (P = 0·016). Notable decreases also included p-BAD (Ser112; -28%, P = 0·004) at 4 h post-EPC compared to PRE levels. In summary, an acute bout of EPC transiently upregulates p-rps6 as well as affecting other markers in the Akt-mTOR signalling cascade. Future research should characterize whether chronic EPC application promotes alterations in lower-limb musculature and/or enhances exercise-induced training adaptations. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Play and optimal welfare: Does play indicate the presence of positive affective states?

Science.gov (United States)

Ahloy-Dallaire, Jamie; Espinosa, Julia; Mason, Georgia

2017-11-16

Play is commonly used to assess affective states in both humans and non-human animals. Play appears to be most common when animals are well-fed and not under any direct threats to fitness. Could play and playfulness therefore indicate pre-existing positive emotions, and thence optimal animal welfare? We examine this question by surveying the internal and external conditions that promote or suppress play in a variety of species, starting with humans. We find that negative affective states and poor welfare usually do suppress play (although there are notable exceptions where the opposite occurs). Furthermore, research in children suggests that beyond the frequency or total duration of play, poor welfare may additionally be reflected in qualitative aspects of this heterogeneous behaviour (e.g. display of solitary over social play; and the 'fragmentation' of play bouts) that are often overlooked in animals. There are surprisingly few studies of play in subjects with pre-existing optimal welfare or in unambiguously highly positive affective states, making it currently impossible to determine whether play can distinguish optimal or good welfare from merely neutral welfare. This therefore represents an important and exciting area for future research. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of current physical activity on affective response to exercise: physical and social-cognitive mechanisms.

Science.gov (United States)

Magnan, Renee E; Kwan, Bethany M; Bryan, Angela D

2013-01-01

Affective responses during exercise are often important determinants of exercise initiation and maintenance. Current physical activity may be one individual difference that is associated with the degree to which individuals have positive (or negative) affective experiences during exercise. The objective of this study was to explore physical and cognitive explanations of the relationship between current activity status (more versus less active) and affective response during a 30-minute bout of moderate-intensity exercise. Participants reported their current level of physical activity, exercise self-efficacy and affect during a 30-minute bout of moderate-intensity exercise. More active individuals experienced higher levels of positive affect and tranquillity and lower levels of negative affect and fatigue during exercise. Multivariate models for each affective state indicated separate processes through which physical activity may be associated with changes in affect during exercise. These models indicate that affect experienced during physical activity is related to the current activity level and these relationships can be partially explained by the physical and cognitive factors explored in this study. Recommendations for future research to elucidate whether positive affective response to physical activity improves as a function of becoming more active over time are discussed.

Short Duration Small Sided Football and to a Lesser Extent Whole Body Vibration Exercise Induce Acute Changes in Markers of Bone Turnover

Directory of Open Access Journals (Sweden)

J. L. Bowtell

2016-01-01

Full Text Available We aimed to study whether short-duration vibration exercise or football sessions of two different durations acutely changed plasma markers of bone turnover and muscle strain. Inactive premenopausal women (n=56 were randomized to complete a single bout of short (FG15 or long duration (FG60 small sided football or low magnitude whole body vibration training (VIB. Procollagen type 1 amino-terminal propeptide (P1NP was increased during exercise for FG15 (51.6±23.0 to 56.5±22.5 μg·L−1, mean ± SD, P0.05. An increase in osteocalcin was observed 48 h after exercise (P<0.05, which did not differ between exercise groups. C-terminal telopeptide of type 1 collagen was not affected by exercise. Blood lactate concentration increased during exercise for FG15 (0.6±0.2 to 3.4±1.2 mM and FG60 (0.6±0.2 to 3.3±2.0 mM, but not for VIB (0.6±0.2 to 0.8±0.4 mM (P<0.05. Plasma creatine kinase increased by 55±63% and 137±119% 48 h after FG15 and FG60 (P<0.05, but not after VIB (26±54%, NS. In contrast to the minor elevation in osteocalcin in response to a single session of vibration exercise, both short and longer durations of small sided football acutely increased plasma P1NP, osteocalcin, and creatine kinase. This may contribute to favorable effects of chronic training on musculoskeletal health.

Swimming training induces liver mitochondrial adaptations to oxidative stress in rats submitted to repeated exhaustive swimming bouts.

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Frederico D Lima

Full Text Available BACKGROUND AND AIMS: Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts. METHODS: Wistar rats were divided into training (n = 14 and control (n = 14 groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7 and control (n = 7 rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed. RESULTS: Trained group showed increased reduced glutathione (GSH content and reduced/oxidized (GSH/GSSG ratio, higher superoxide dismutase (MnSOD activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group. CONCLUSIONS: Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance.

Cunnilingus apparently increases duration of copulation in the Indian flying fox, Pteropus giganteus.

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Jayabalan Maruthupandian

Full Text Available We observed a total of 57 incidences of copulation in a colony of the Indian flying fox, Pteropus giganteus, over 13 months under natural conditions. The colony consisted of about 420 individuals, roosting in a Ficus religiosa tree. Copulations occurred between 07.00 h and 09.30 h from July to January, with more occurring in October and November. Initially males groomed their penis before approaching a nearby female. Females typically moved away and males followed. When the female stopped moving, the male started licking her vagina (cunnilingus. Typically each bout of cunnilingus lasted for about 50 s. In 57 out of 69 observations, the male mounted the female and copulated. The duration of copulation varied from 10 to 20 sec. After completion of copulation, the male continued cunnilingus for 94 to 188 sec. The duration of pre-copulatory cunnilingus and copulation was positively correlated whereas, the duration of pre- and post-copulatory cunnilingus was negatively correlated. Apart from humans, oral sex as foreplay prior to copulation is uncommon in mammals. Another pteropodid bat, Cynopterus sphinx exhibits fellatio with females licking the penis of males during copulation. It appears that bats, especially pteropodids perform oral sex, either cunnilingus or fellatio, possibly for achieving longer copulation.

Acute Bouts of Exercising Improved Mood, Rumination and Social Interaction in Inpatients With Mental Disorders

Science.gov (United States)

Brand, Serge; Colledge, Flora; Ludyga, Sebastian; Emmenegger, Raphael; Kalak, Nadeem; Sadeghi Bahmani, Dena; Holsboer-Trachsler, Edith; Pühse, Uwe; Gerber, Markus

2018-01-01

Background: Studies at the macro level (such as longer-term interventions) showed that physical activity impacts positively on cognitive-emotional processes of patients with mental disorders. However, research focusing on the immediate impact of acute bouts of exercise (micro level) are missing. The aim of the present study was therefore to investigate whether and to what extent single bouts of moderately intense exercise can influence dimensions of psychological functioning in inpatients with mental disorders. Method: 129 inpatients (mean age: 38.16 years; 50.4% females) took part and completed a questionnaire both immediately before and immediately after exercising. Thirty inpatients completed the questionnaires a second time in the same week. The questionnaire covered socio-demographic and illness-related information. Further, the questionnaire asked about current psychological states such as mood, rumination, social interactions, and attention, tiredness, and physical strengths as a proxy of physiological states. Results: Psychological states improved from pre- to post-session. Improvements were observed for mood, social interactions, attention, and physical strengths. Likewise, rumination and tiredness decreased. Mood, rumination, and tiredness further improved, when patients completed the questionnaires the second time in the same week. Conclusion: At micro level, single bouts of exercise impacted positively on cognitive-emotional processes such as mood, rumination, attention and social interactions, and physiological states of tiredness and physical strengths among inpatients with mental disorders. In addition, further improvements were observed, if patients participated in physical activities a second time. PMID:29593592

Acute Bouts of Exercising Improved Mood, Rumination and Social Interaction in Inpatients With Mental Disorders

Directory of Open Access Journals (Sweden)

Serge Brand

2018-03-01

Full Text Available Background: Studies at the macro level (such as longer-term interventions showed that physical activity impacts positively on cognitive-emotional processes of patients with mental disorders. However, research focusing on the immediate impact of acute bouts of exercise (micro level are missing. The aim of the present study was therefore to investigate whether and to what extent single bouts of moderately intense exercise can influence dimensions of psychological functioning in inpatients with mental disorders.Method: 129 inpatients (mean age: 38.16 years; 50.4% females took part and completed a questionnaire both immediately before and immediately after exercising. Thirty inpatients completed the questionnaires a second time in the same week. The questionnaire covered socio-demographic and illness-related information. Further, the questionnaire asked about current psychological states such as mood, rumination, social interactions, and attention, tiredness, and physical strengths as a proxy of physiological states.Results: Psychological states improved from pre- to post-session. Improvements were observed for mood, social interactions, attention, and physical strengths. Likewise, rumination and tiredness decreased. Mood, rumination, and tiredness further improved, when patients completed the questionnaires the second time in the same week.Conclusion: At micro level, single bouts of exercise impacted positively on cognitive-emotional processes such as mood, rumination, attention and social interactions, and physiological states of tiredness and physical strengths among inpatients with mental disorders. In addition, further improvements were observed, if patients participated in physical activities a second time.

Acute Bouts of Exercising Improved Mood, Rumination and Social Interaction in Inpatients With Mental Disorders.

Science.gov (United States)

Brand, Serge; Colledge, Flora; Ludyga, Sebastian; Emmenegger, Raphael; Kalak, Nadeem; Sadeghi Bahmani, Dena; Holsboer-Trachsler, Edith; Pühse, Uwe; Gerber, Markus

2018-01-01

Background: Studies at the macro level (such as longer-term interventions) showed that physical activity impacts positively on cognitive-emotional processes of patients with mental disorders. However, research focusing on the immediate impact of acute bouts of exercise (micro level) are missing. The aim of the present study was therefore to investigate whether and to what extent single bouts of moderately intense exercise can influence dimensions of psychological functioning in inpatients with mental disorders. Method: 129 inpatients (mean age: 38.16 years; 50.4% females) took part and completed a questionnaire both immediately before and immediately after exercising. Thirty inpatients completed the questionnaires a second time in the same week. The questionnaire covered socio-demographic and illness-related information. Further, the questionnaire asked about current psychological states such as mood, rumination, social interactions, and attention, tiredness, and physical strengths as a proxy of physiological states. Results: Psychological states improved from pre- to post-session. Improvements were observed for mood, social interactions, attention, and physical strengths. Likewise, rumination and tiredness decreased. Mood, rumination, and tiredness further improved, when patients completed the questionnaires the second time in the same week. Conclusion: At micro level, single bouts of exercise impacted positively on cognitive-emotional processes such as mood, rumination, attention and social interactions, and physiological states of tiredness and physical strengths among inpatients with mental disorders. In addition, further improvements were observed, if patients participated in physical activities a second time.

Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

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Gail M Blundell

Full Text Available Large numbers of harbor seals (Phoca vitulina use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less

Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

Science.gov (United States)

Blundell, Gail M; Pendleton, Grey W

2015-01-01

Large numbers of harbor seals (Phoca vitulina) use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less optimally, 09:00-16:00.

Extracting objective estimates of sedentary behavior from accelerometer data: measurement considerations for surveillance and research applications.

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Youngdeok Kim

Full Text Available Accelerometer-based activity monitors are widely used in research and surveillance applications for quantifying sedentary behavior (SB and physical activity (PA. Considerable research has been done to refine methods for assessing PA, but relatively little attention has been given to operationalizing SB parameters (i.e., sedentary time and breaks from accelerometer data - particularly in relation to health outcomes. This study investigated: (a the accrued patterns of sedentary time and breaks; and (b the associations of sedentary time and breaks in different bout durations with cardiovascular risk factors.Accelerometer data on 5,917 adults from the National Health Examination and Nutrition Survey (NHANES 2003-2006 were used. Sedentary time and breaks at different bout durations (i.e., 1, 2-4, 5-9, 10-14, 15-19, 20-24, 25-29, and ≥ 30-min were obtained using a threshold of < 100 counts per minute. Sedentary time and breaks were regressed on cardiovascular risk factors (waist circumference, triglyceride, and high-density lipoprotein cholesterol and body mass index across bout durations.The results revealed that the majority of sedentary time occurred within relatively short bout durations (≈ 70% and ≈ 85% for < 5-min and < 10-min, respectively. The associations of sedentary time and breaks with health outcomes varied depending on how bout time was defined. Estimates of SB parameters based on bout durations of 5 min or shorter were associated with reduced cardiovascular risk factors while durations longer than 10-min were generally associated with increased risk factors.The present study demonstrates that the duration of sedentary bouts should be further considered when operationalizing the SB parameters from accelerometer data. The threshold of 5 minutes to define a bout is defensible, but a 10 minute threshold would provide a more conservative estimate to clearly capture the prolonged nature of sedentary behavior. Additional research is

SALIVARY CORTISOL RESPONSES AND PERCEIVED EXERTION DURING HIGH INTENSITY AND LOW INTENSITY BOUTS OF RESISTANCE EXERCISE

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Alison D. Egan

2004-03-01

Full Text Available The purpose of this study was to measure the salivary cortisol response to different intensities of resistance exercise. In addition, we wanted to determine the reliability of the session rating of perceived exertion (RPE scale to monitor resistance exercise intensity. Subjects (8 men, 9 women completed 2 trials of acute resistance training bouts in a counterbalanced design. The high intensity resistance exercise protocol consisted of six, ten-repetition sets using 75% of one repetition maximum (RM on a Smith machine squat and bench press exercise (12 sets total. The low intensity resistance exercise protocol consisted of three, ten-repetition sets at 30% of 1RM of the same exercises as the high intensity protocol. Both exercise bouts were performed with 2 minutes of rest between each exercise and sessions were repeated to test reliability of the measures. The order of the exercise bouts was randomized with least 72 hours between each session. Saliva samples were obtained immediately before, immediately after and 30 mins following each resistance exercise bout. RPE measures were obtained using Borg's CR-10 scale following each set. Also, the session RPE for the entire exercise session was obtained 30 minutes following completion of the session. There was a significant 97% increase in the level of salivary cortisol immediately following the high intensity exercise session (P<0.05. There was also a significant difference in salivary cortisol of 145% between the low intensity and high intensity exercise session immediately post-exercise (P<0.05. The low intensity exercise did not result in any significant changes in cortisol levels. There was also a significant difference between the session RPE values for the different intensity levels (high intensity 7.1 vs. low intensity 1.9 (P<0.05. The intraclass correlation coefficient for the session RPE measure was 0.95. It was concluded that the session RPE method is a valid and reliable method of

Analysis of plasma instabilities and verification of the BOUT code for the Large Plasma Device

International Nuclear Information System (INIS)

Popovich, P.; Carter, T. A.; Friedman, B.; Umansky, M. V.

2010-01-01

The properties of linear instabilities in the Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] are studied both through analytic calculations and solving numerically a system of linearized collisional plasma fluid equations using the three-dimensional fluid code BOUT[M. Umansky et al., Contrib. Plasma Phys. 180, 887 (2009)], which has been successfully modified to treat cylindrical geometry. Instability drive from plasma pressure gradients and flows is considered, focusing on resistive drift waves and the Kelvin-Helmholtz and rotational interchange instabilities. A general linear dispersion relation for partially ionized collisional plasmas including these modes is derived and analyzed. For Large Plasma Device relevant profiles including strongly driven flows, it is found that all three modes can have comparable growth rates and frequencies. Detailed comparison with solutions of the analytic dispersion relation demonstrates that BOUT accurately reproduces all characteristics of linear modes in this system.

The Influence of a Bout of Exertion on Novice Barefoot Running Dynamics

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Rami Hashish, Sachithra D. Samarawickrame, Lucinda Baker, George J. Salem

2016-06-01

Full Text Available Barefoot, forefoot strike (FFS running has recently risen in popularity. Relative to shod, rear-foot strike (RFS running, employing a FFS is associated with heightened triceps surae muscle activation and ankle mechanical demand. Novice to this pattern, it is plausible that habitually shod RFS runners exhibit fatigue to the triceps surae when acutely transitioning to barefoot running, thereby limiting their ability to attenuate impact. Therefore, the purpose was to determine how habitually shod RFS runners respond to an exertion bout of barefoot running, operationally defined as a barefoot run 20% of mean daily running distance. Twenty-one RFS runners performed novice barefoot running, before and after exertion. Ankle peak torque, triceps surae EMG median frequency, foot-strike patterns, joint energy absorption, and loading rates were evaluated. Of the 21 runners, 6 maintained a RFS, 10 adopted a mid-foot strike (MFS, and 5 adopted a FFS during novice barefoot running. In-response to exertion, MFS and FFS runners demonstrated reductions in peak torque, median frequency, and ankle energy absorption, and an increase in loading rate. RFS runners demonstrated reductions in peak torque and loading rate. These results indicate that a short bout of running may elicit fatigue to novice barefoot runners, limiting their ability to attenuate impact.

5000 Meter Run Performance is not Enhanced 24 Hrs After an Intense Exercise Bout and Cold Water Immersion.

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Stenson, Mary C; Stenson, Matthew R; Matthews, Tracey D; Paolone, Vincent J

2017-06-01

Cold water immersion (CWI) is used by endurance athletes to speed recovery between exercise bouts, but little evidence is available on the effects of CWI on subsequent endurance performance. The purpose of this study was to investigate the effects of CWI following an acute bout of interval training on 5000 m run performance 24 hrs after interval training, perceived muscle soreness (PMS), range of motion (ROM), thigh circumference (TC), and perceived exertion (RPE). Nine endurance-trained males completed 2 trials, each consisting of an interval training session of 8 repetitions of 1200 m at a running pace equal to 75% of VO 2 peak, either a control or CWI treatment, and a timed 5000 m run 24 hrs post interval training session. CWI was performed for 12 min at 12 degrees Celsius on the legs. Recovery treatments were performed in a counterbalanced design. Run time for 5000 m was not different between the CWI and control trials (CWI = 1317.33 ± 128.33 sec, control = 1303.44 ± 105.53 sec; p = 0.48). PMS increased significantly from baseline to immediately post exercise (BL = 1.17 ± 0.22, POST = 2.81 ± 0.52; p = 0.02) and remained elevated from baseline to 24 hrs post exercise (POST24 = 2.19 ± 0.32; p = 0.02), but no difference was observed between the treatments. No differences were observed for the interaction between time and treatment for TC (λ = 0.73, p = 0.15) and ROM (λ = 0.49; p = 0.10). CWI performed immediately following an interval training exercise bout did not enhance subsequent 5000 m run performance or reduce PMS. CWI may not provide a recovery or performance advantage when athletes are accustomed to the demands of the prior exercise bout.

What Is the Effect on Obesity Indicators from Replacing Prolonged Sedentary Time with Brief Sedentary Bouts, Standing and Different Types of Physical Activity during Working Days? A Cross-Sectional Accelerometer-Based Study among Blue-Collar Workers.

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Gupta, Nidhi; Heiden, Marina; Aadahl, Mette; Korshøj, Mette; Jørgensen, Marie Birk; Holtermann, Andreas

2016-01-01

The aim of the study was to investigate if (a) substituting total sedentary time or long sedentary bouts with standing or various types of physical activity and (b) substituting long sedentary bouts with brief sedentary bouts; is associated with obesity indicators using a cross sectional isotemporal substitution approach among blue-collar workers. A total of 692 workers from transportation, manufacturing and cleaning sectors wore an Actigraph GT3X+ accelerometer on the thigh for 1-4 working days. The sedentary (sit and lie), standing, walking, and moderate to vigorous physical activity (MVPA) time on working days was computed using validated Acti4 software. The total sedentary time and uninterrupted sedentary time spent in brief (≤5 mins), moderate (>5 and ≤30 mins), and long (>30mins) bouts, were determined for the whole day and during work and non-work time separately. The obesity indicators, BMI (kg/m2), waist circumference (cm) and fat percentage were objectively measured. Isotemporal substitution modelling was utilized to determine the linear association with obesity indicators of replacing 30 min of total sedentary time or long sedentary bouts with standing, walking or MVPA and separately replacing 30 min of long sedentary bouts with brief sedentary bouts. Workers [mean (standard deviation, SD); age = 45.1 (9.9) years, BMI = 27.5 (4.9) kg/m2, %BF = 29.6 (9.5), waist circumference = 94.4 (13.0) cm] sat for 2.4 hours (~32% of the measured time, SD = 1.8 hours) across the day during work period and 5.5 hours (~62% of the measured time, SD = 1.5 hours) during non-work period. Most of the sedentary time was accrued in moderate bouts [work = 1.40 (SD = 1.09) hours] during work and in long bouts during non-work [2.7 (SD = 1.4) hours], while least in long sedentary bouts during work [work = 0.5 (SD = 0.9)] and in brief sedentary bouts [0.5 hours (SD = 0.3)] during non-work. Significant associations with all obesity indicators were found when 30 min of total

The association between short periods of everyday life activities and affective states: a replication study using ambulatory assessment

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Thomas eBossmann

2013-04-01

Full Text Available Regularly conducted exercise programs effectively influence affective states. Studies suggest that this is also true for short bouts of physical activity of ten minutes or less. Accordingly, everyday life activities of short duration might be used to regulate affective states. However, this association has rarely been studied in reference to unstructured activities in ongoing real-life situations. The current study examined the influence of various everyday life activities on three dimensions of mood (valence, calmness, energetic arousal in a predominantly inactive sample. Ambulatory Assessment (AA was used to investigate the association between actual physical activity (aPA and affective states during the course of one day. Seventy-seven students ages 19 - 30 participated in the study. aPA was assessed with accelerometers, and affective state assessments were conducted hourly using an e-diary with a six-item mood scale that was specially designed for AA. Multilevel analyses indicated that the mood dimensions energetic arousal (p = .001 and valence (p = .005 were positively influenced by the intensity of the activity carried out in the ten minutes prior to the assessment. As their activity increased, the participants’ positive feelings and energetic arousal increased. However, the students’ calmness was not affected by their activity levels. The findings highlight the importance of integrating short activity intervals of 10 minutes or less into everyday life routines to improve affective states.

Dose-Response Effects of Exercise Duration and Recovery on Cognitive Functioning.

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Crush, Elizabeth A; Loprinzi, Paul D

2017-12-01

We examined the effects of different acute exercise durations and recovery periods on cognitive function in a counterbalanced, cross-over randomized controlled experiment. We placed 352 participants, aged 18 to 35 years into one of 16 experimental groups. Each participant visited the laboratory twice, separated by a 1-week washout period. Either Visit 1 or 2 consisted of an acute bout of moderate-intensity treadmill exercise (10, 20, 30, 45, or 60 minutes) followed by a period of rest (5, 15, or 30 minutes) before taking a set of five cognitive tests; the other visit consisted only of completing the cognitive tests (no exercise). Cognitive tests sampled multiple cognitive parameters, including reasoning, concentration, memory, attention, and planning. We found that a short recovery period (i.e., 5 minutes) may have a less favorable effect on planning ability but may be beneficial for memory. In addition, for various exercise durations and recovery periods, a Group × Time × Resting (nonexercise) A cognitive interaction effect was observed such that for both memory and inhibitory cognitive ability, acute exercise (vs. no exercise) had an enhancement effect for those with lower resting cognitive functioning. The length of the acute exercise recovery period and resting cognitive ability most influenced the association between exercise and cognitive function.

The effects of a single bout pilates exercise on mRNA expression of bone metabolic cytokines in osteopenia women.

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Kim, Chang Sun; Kim, Ji Yeon; Kim, Hyo Jin

2014-03-01

The purpose of this study was to examine the effect of a single bout pilates exercise on mRNA expression of bone metabolic cytokines in elderly osteopenia women. We selected 11 people of elderly osteopenia women and loaded a single bout pilates exercise about RPE 10-14 level. The blood samples were collected before, immediately after and 60 minute after pilates exercise, then examined calcium metabolic markers in serum and extracted peripheral blood mononuclear cell (PBMC) from whole blood and confirmed mRNA expression of bone metabolic cytokines from PBMC. To clarify the changes during exercise, we designed repeated measure ANOVA as the control group to perform blood sampling without exercise. As a result, serum P showed significant interaction effect between group and time (ppilates exercise group decreased about 9% at immediately after exercise and 13% during recovery after exercise (ppilates group significantly increased at immediately after exercise and during recovery after exercise (ppilates group (ppilates group (NS). These results suggested that a single bout pilates exercise of elderly osteopenia women cause hypophosphatemia with temporary muscle damage, and it leading high turnover bone metabolic state with to activate both of bone formation and bone resorption.

Design and baseline characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study.

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Alhassan, Sofiya; Nwaokelemeh, Ogechi; Mendoza, Albert; Shitole, Sanyog; Whitt-Glover, Melicia C; Yancey, Antronette K

2012-08-01

Most preschool centers provide two 30-min sessions of gross-motor/outdoor playtime per preschool day. Within this time frame, children accumulate most of their activity within the first 10 min. This paper describes the design and baseline participant characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study. The STEP study is a cluster randomized controlled study designed to examine the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on during-school physical activity (PA) in preschoolers. Ten preschool centers serving low-income families were randomized into SBS-PA versus unstructured PA (UPA). SBS-PA schools were asked to implement age-appropriate 10 min structured PA routines within the classroom setting, twice daily, followed by 20 min of usual unstructured playtime. UPA intervention consisted of 30 min of supervised unstructured free playtime twice daily. Interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for six months. Outcome measures were between group difference in during-preschool PA (accelerometers and direct observation) over six-months. Ten preschool centers, representing 34 classrooms and 315 children, enrolled in the study. The average age and BMI percentile for the participants was 4.1 ± 0.8 years and 69th percentile, respectively. Participants spent 74% and 6% of their preschool day engaged in sedentary and MVPA, respectively. Results from the STEP intervention could provide evidence that a PA policy that exposes preschoolers to shorter bouts of structured PA throughout the preschool day could potentially increase preschoolers' PA levels.

Effect of temperament on cortisol response to a single exercise bout in Thoroughbred racehorses - short communication.

Science.gov (United States)

Bohák, Zsófia; Szenci, Ottó; Harnos, Andrea; Kutasi, Orsolya; Kovács, Levente

2017-12-01

Temperament has not been taken into account in previous studies evaluating the stress response to exercise in horses. The aim of the present study was to investigate the cortisol response in Thoroughbred racehorses to a single exercise bout, and to analyse the results based on the basic personality of the horse examined. Twenty healthy Thoroughbred horses were selected for the study based on a 25-item rating questionnaire survey used for characterising equine temperament. Eight temperamental and twelve calm horses took part in the experiment. The horses trotted as a warm-up activity, and then galloped on a rounded sand track. Blood sampling was conducted four times for each horse. Horses with a more excitable temperament showed a higher cortisol response to the test (P = 0.036). In conclusion, cortisol levels in response to a mild intensive exercise can be affected by temperament in horses. Serum cortisol may be a relevant marker to quantify individual temperamental differences in racehorses.

Associations between lying behavior and lameness in Canadian Holstein-Friesian cows housed in freestall barns.

Science.gov (United States)

Solano, L; Barkema, H W; Pajor, E A; Mason, S; LeBlanc, S J; Nash, C G R; Haley, D B; Pellerin, D; Rushen, J; de Passillé, A M; Vasseur, E; Orsel, K

2016-03-01

, or standard deviations of bout duration over 4 d ≥ 70 min had 3.7, 1.7, 2.5, and 3.0 higher odds of being lame, respectively. Factors related to comfort of lying and standing surfaces significantly affected lying behavior. Finally, we inferred that automated measures of lying behavior could contribute to lameness detection, especially when interpreted in the context of other factors known to affect lying behavior, including those associated with the individual cow (e.g., parity and stage of lactation) or environment (e.g., stall surface). Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Use of novel sensors combining local positioning and acceleration to measure feeding behavior differences associated with lameness in dairy cattle.

Science.gov (United States)

Barker, Z E; Vázquez Diosdado, J A; Codling, E A; Bell, N J; Hodges, H R; Croft, D P; Amory, J R

2018-04-25

Time constraints for dairy farmers are an important factor contributing to the under-detection of lameness, resulting in delayed or missed treatment of lame cows within many commercial dairy herds. Hence, a need exists for flexible and affordable cow-based sensor systems capable of monitoring behaviors such as time spent feeding, which may be affected by the onset of lameness. In this study a novel neck-mounted mobile sensor system that combines local positioning and activity (acceleration) was tested and validated on a commercial UK dairy farm. Position and activity data were collected over 5 consecutive days for 19 high-yield dairy cows (10 lame, 9 nonlame) that formed a subset of a larger (120 cow) management group housed in a freestall barn. A decision tree algorithm that included sensor-recorded position and accelerometer data was developed to classify a cow as doing 1 of 3 categories of behavior: (1) feeding, (2) not feeding, and (3) out of pen for milking. For each classified behavior the mean number of bouts, the mean bout duration, and the mean total duration across all bouts was determined on a daily basis, and also separately for the time periods in between milking (morning = 0630-1300 h; afternoon = 1430-2100 h; night = 2230-0500 h). A comparative analysis of the classified cow behaviors was undertaken using a Welch t-test with Benjamini-Hochberg post-hoc correction under the null hypothesis of no differences in the number or duration of behavioral bouts between the 2 test groups of lame and nonlame cows. Analysis showed that mean total daily feeding duration was significantly lower for lame cows compared with non-lame cows. Behavior was also affected by time of day with significantly lower mean total duration of feeding and higher total duration of nonfeeding in the afternoons for lame cows compared with nonlame cows. The results demonstrate how sensors that measure both position and acceleration are capable of detecting differences in feeding behavior

Time budgets of lactating dairy cattle in commercial freestall herds.

Science.gov (United States)

Gomez, A; Cook, N B

2010-12-01

The aim of this study was to examine the time budgets of 205 lactating dairy cows housed in 16 freestall barns in Wisconsin and to determine the relationships between components of the time budget and herd- and cow-level fixed effects using mixed models. Using continuous video surveillance, time lying in the stall, time standing in the stall, time standing in the alleys (including drinking), time feeding, and time milking (time out of the pen for milking and transit) during a 24-h period were measured for each cow. In addition, the number of lying bouts and the mean duration of each lying bout per 24-h period were determined. Time milking varied between cows from 0.5 to 6.0 h/d, with a mean ± standard deviation of 2.7 ± 1.1h/d. Time milking was influenced significantly by pen stocking density, and time milking negatively affected time feeding, time lying, and time in the alley, but not time standing in the stall. Locomotion score, either directly or through an interaction with stall base type (a rubber crumb-filled mattress, MAT, or sand bedding, SAND), influenced pen activity. Lame cows spent less time feeding, less time in the alleys, and more time standing in the stalls in MAT herds, but not in SAND herds. The effect of lameness on lying time is complex and dependent on the time available for rest and differences in resting behavior observed between cows in MAT and SAND herds. In MAT herds, rest was characterized by a larger number of lying bouts of shorter duration than in SAND herds (mean = 14.4; confidence interval, CI: 12.4 to 16.5 vs. mean = 10.2; CI: 8.2 to 12.2 bouts per d, and mean = 1.0; CI: 0.9 to 1.1 vs. mean = 1.3, CI: 1.2 to 1.4h bout duration for MAT and SAND herds, respectively). Lameness was associated with an increase in time standing in the stall and a reduction in the mean (CI) number of lying bouts per day from 13.2 (CI: 12.3 to 14.1) bouts/d for nonlame cows to 10.9 (CI: 9.30 to 12.8) bouts/d for moderately lame cows, and an overall

Eicosanoid Production following One Bout of Exercise in Middle-Aged African American Pre- and Stage 1 Hypertensives

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Sheara Williamson

2011-01-01

Full Text Available Endothelial dysfunction and a sedentary lifestyle may be involved in the development of hypertension which is proliferative among middle-aged African Americans (AA. Signaling molecules derived from the oxidation of 20-carbon fatty acid molecules known as eicosanoids influence vascular tone. The relationship between aerobic fitness and eicosanoid formation following exercise in middle-aged African American hypertensives is unknown. Purpose. To determine the relationship between aerobic capacity and eicosanoid formation after a bout of moderate-intensity exercise in middle-aged AA hypertensives. Methods. Ten sedentary hypertensive AA underwent 50 min of aerobic exercise at 65% VO2max. Urine was collected for 24 hr on two occasions, prior to testing and immediately following the bout of exercise. Urinary metabolites of prostacyclin (6-keto PGF1α and thromboxane (11-dTXB2 were measured during the day and night periods by high-performance liquid chromatography (HPLC. Results. 6-keto PGF1α levels significantly increased (=.04 following the bout of exercise compared to the control day. There was a significant relationship (=.49, <.05 between 6-keto PGF1α levels and VO2max during the exercise day. Conclusion. Based on this preliminary study, there appears to be a relationship between aerobic capacity and exercise-induced 6-keto PGF1α production in middle-aged hypertensive AAs. AAs with lower VO2max had lower 6-keto PGF1α formation.

Using ecological momentary assessment to examine antecedents and correlates of physical activity bouts in adults age 50+ years: a pilot study.

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Dunton, Genevieve Fridlund; Atienza, Audie A; Castro, Cynthia M; King, Abby C

2009-12-01

National recommendations supporting the promotion of multiple short (10+ minute) physical activity bouts each day to increase overall physical activity levels in middle-aged and older adults underscore the need to identify antecedents and correlates of such daily physical activity episodes. This pilot study used Ecological Momentary Assessment to examine the time-lagged and concurrent effects of empirically supported social, cognitive, affective, and physiological factors on physical activity among adults age 50+ years. Participants (N = 23) responded to diary prompts on a handheld computer four times per day across a 2-week period. Moderate-to-vigorous physical activity (MVPA), self-efficacy, positive and negative affect, control, demand, fatigue, energy, social interactions, and stressful events were assessed during each sequence. Multivariate results showed that greater self-efficacy and control predicted greater MVPA at each subsequent assessment throughout the day (p positive social interaction was concurrently related to higher levels of MVPA (p = 0.052). Time-varying multidimensional individual processes predict within daily physical activity levels.

The effects of a repeated bout of eccentric exercise on indices of muscle damage and delayed onset muscle soreness.

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Paddon-Jones, D; Muthalib, M; Jenkins, D

2000-03-01

This study examined markers of muscle damage following a repeated bout of maximal isokinetic eccentric exercise performed prior to full recovery from a previous bout. Twenty non-resistance trained volunteers were randomly assigned to a control (CON, n=10) or experimental (EXP, n=10) group. Both groups performed 36 maximal isokinetic eccentric contractions of the elbow flexors of the non-dominant arm (ECC1). The EXP group repeated the same eccentric exercise bout two days later (ECC2). Total work and peak eccentric torque were recorded during each set of ECC1 and ECC2. Isometric torque, delayed onset muscle soreness (DOMS), flexed elbow angle and plasma creatine kinase (CK) activity were measured prior to and immediately following ECC1 and ECC2. at 24h intervals for 7 days following ECC1 and finally on day 11. In both groups, all dependent variables changed significantly during the 2 days following ECC1. A further acute post-exercise impairment in isometric torque (30 +/- 5%) and flexed elbow angle (20 +/- 4%) was observed following ECC2 (p0.05). These findings suggest that when maximal isokinetic eccentric exercise is repeated two days after experiencing of contraction-induced muscle damage, the recovery time course is not significantly altered.

T-lymphocyte subset dynamics in well-treated HIV-infected men during a bout of exhausting exercise

DEFF Research Database (Denmark)

Dirksen, Carsten; Hansen, Birgitte R; Kolte, Lilian

2015-01-01

In healthy individuals the substantial lymphocytosis during a bout of exhausting exercise constitutes primarily mature T cells from the peripheral lymphoid organs but naïve T cells are also recruited. This study investigated whether the defective CD4 + T-lymphocyte count in peripheral blood during...

A single bout of resistance exercise can enhance episodic memory performance.

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Weinberg, Lisa; Hasni, Anita; Shinohara, Minoru; Duarte, Audrey

2014-11-01

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

Design and baseline characteristics of the Short bouTs of Exercise for Preschoolers (STEP study

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Alhassan Sofiya

2012-08-01

Full Text Available Abstract Background Most preschool centers provide two 30-min sessions of gross-motor/outdoor playtime per preschool day. Within this time frame, children accumulate most of their activity within the first 10 min. This paper describes the design and baseline participant characteristics of the Short bouTs of Exercise for Preschoolers (STEP study. The STEP study is a cluster randomized controlled study designed to examine the effects of short bouts of structured physical activity (SBS-PA implemented within the classroom setting as part of designated gross-motor playtime on during-school physical activity (PA in preschoolers. Methods/Design Ten preschool centers serving low-income families were randomized into SBS-PA versus unstructured PA (UPA. SBS-PA schools were asked to implement age-appropriate 10 min structured PA routines within the classroom setting, twice daily, followed by 20 min of usual unstructured playtime. UPA intervention consisted of 30 min of supervised unstructured free playtime twice daily. Interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for six months. Outcome measures were between group difference in during-preschool PA (accelerometers and direct observation over six-months. Ten preschool centers, representing 34 classrooms and 315 children, enrolled in the study. The average age and BMI percentile for the participants was 4.1 ± 0.8 years and 69th percentile, respectively. Participants spent 74% and 6% of their preschool day engaged in sedentary and MVPA, respectively. Discussion Results from the STEP intervention could provide evidence that a PA policy that exposes preschoolers to shorter bouts of structured PA throughout the preschool day could potentially increase preschoolers’ PA levels. Trial registration Clinicaltrials.gov, NCT01588392

Repeated Bout Effect Was More Expressed in Young Adult Males Than in Elderly Males and Boys

Directory of Open Access Journals (Sweden)

Giedrius Gorianovas

2013-01-01

Full Text Available This study investigated possible differences using the same stretch-shortening exercise (SSE protocol on generally accepted monitoring markers (dependent variables: changes in creatine kinase, muscle soreness, and voluntary and electrically evoked torque in males across three lifespan stages (childhood versus adulthood versus old age. The protocol consisted of 100 intermittent (30 s interval between jumps drop jumps to determine the repeated bout effect (RBE (first and second bouts performed at a 2-week interval. The results showed that indirect symptoms of exercise-induced muscle damage after SSE were more expressed in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are more resistant to exercise-induced damage than those of adult males. RBE was more pronounced in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are less adaptive to exercise-induced muscle damage than those of adult males.

Psychosocial issues affecting crews during long-duration international space missions

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Kanas, N.

1998-01-01

Psychosocial issues can negatively impact on crew performance and morale during long-duration international space missions. Major psychosocial factors that have been described in anecdotal reports from space and in studies from analog situations on Earth include: 1) crew heterogeneity due to gender differences, cultural issues, and work experiences and motivations; 2) language and dialect variations; and 3) task versus supportive leadership roles. All of these factors can lead to negative sequelae, such as intra-crew tension and cohesion disruptions. Specific sequelae that can result from single factors include subgrouping and scapegoating due to crew heterogeneity; miscommunication due to major or subtle language differences; and role confusion, competition, and status leveling due to inappropriate leadership role definition. It is time to conduct research exploring the impact of these psychosocial factors and their sequelae on space crews during actual long-duration international space missions.

The influence of a consumer-wearable activity tracker on sedentary time and prolonged sedentary bouts: secondary analysis of a randomized controlled trial.

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Sloan, Robert A; Kim, Youngdeok; Sahasranaman, Aarti; Müller-Riemenschneider, Falk; Biddle, Stuart J H; Finkelstein, Eric A

2018-03-22

A recent meta-analysis surmised pedometers were a useful panacea to independently reduce sedentary time (ST). To further test and expand on this deduction, we analyzed the ability of a consumer-wearable activity tracker to reduce ST and prolonged sedentary bouts (PSB). We originally conducted a 12-month randomized control trial where 800 employees from 13 organizations were assigned to control, activity tracker, or one of two activity tracker plus incentive groups designed to increase step count. The primary outcome was accelerometer measured moderate-to-vigorous physical activity. We conducted a secondary analysis on accelerometer measured daily ST and PSB bouts. A general linear mixed model was used to examine changes in ST and prolonged sedentary bouts, followed by between-group pairwise comparisons. Regression analyses were conducted to examine the association of changes in step counts with ST and PSB. The changes in ST and PSB were not statistically significant and not different between the groups (P consumer-wearable activity trackers as a means to reduce sedentary behavior. Trial registration NCT01855776 Registered: August 8, 2012.

Effects of one versus two bouts of moderate intensity physical activity on selective attention during a school morning in Dutch primary schoolchildren: A randomized controlled trial.

Science.gov (United States)

Altenburg, Teatske M; Chinapaw, Mai J M; Singh, Amika S

2016-10-01

Evidence suggests that physical activity is positively related to several aspects of cognitive functioning in children, among which is selective attention. To date, no information is available on the optimal frequency of physical activity on cognitive functioning in children. The current study examined the acute effects of one and two bouts of moderate-intensity physical activity on children's selective attention. Randomized controlled trial (ISRCTN97975679). Thirty boys and twenty-six girls, aged 10-13 years, were randomly assigned to three conditions: (A) sitting all morning working on simulated school tasks; (B) one 20-min physical activity bout after 90min; and (C) two 20-min physical activity bouts, i.e. at the start and after 90min. Selective attention was assessed at five time points during the morning (i.e. at baseline and after 20, 110, 130 and 220min), using the 'Sky Search' subtest of the 'Test of Selective Attention in Children'. We used GEE analysis to examine differences in Sky Search scores between the three experimental conditions, adjusting for school, baseline scores, self-reported screen time and time spent in sports. Children who performed two 20-min bouts of moderate-intensity physical activity had significantly better Sky Search scores compared to children who performed one physical activity bout or remained seated the whole morning (B=-0.26; 95% CI=[-0.52; -0.00]). Our findings support the importance of repeated physical activity during the school day for beneficial effects on selective attention in children. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effects of an acute bout of exercise on memory in 6th grade children.

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Etnier, Jennifer; Labban, Jeffrey D; Piepmeier, Aaron; Davis, Matthew E; Henning, David A

2014-08-01

Research supports the positive effects of exercise on cognitive performance by children. However, a limited number of studies have explored the effects specifically on memory. The purpose of this study was to compare the effects of an acute bout of exercise on learning, short-term memory, and long-term memory in a sample of children. Children were randomly assigned to an exercise condition or to a no-treatment control condition and then performed repeated trials on an auditory verbal learning task. In the exercise condition, participants performed the PACER task, an aerobic fitness assessment, in their physical education class before performing the memory task. In the control condition, participants performed the memory task at the beginning of their physical education class. Results showed that participants in the exercise condition demonstrated significantly better learning of the word lists and significantly better recall of the words after a brief delay. There were not significant differences in recognition of the words after an approximately 24-hr delay. These results provide evidence in a school setting that an acute bout of exercise provides benefits for verbal learning and long-term memory. Future research should be designed to identify the extent to which these findings translate to academic measures.

Physical activity in the school setting: cognitive performance is not affected by three different types of acute exercise

NARCIS (Netherlands)

Van den Berg, Vera; Saliasi, Emi; De Groot, Renate; Jolles, Jelle; Chin A Paw, Mai; Singh, Amika

2016-01-01

Recent studies indicate that a single bout of physical exercise can have immediatepositive effects on cognitive performance of children and adolescents. However, thetype of exercise that affects cognitive performance the most in young adolescents isnot fully understood. Therefore, this controlled

The Influence of a Bout of Exertion on Novice Barefoot Running Dynamics.

Science.gov (United States)

Hashish, Rami; Samarawickrame, Sachithra D; Baker, Lucinda; Salem, George J

2016-06-01

Barefoot, forefoot strike (FFS) running has recently risen in popularity. Relative to shod, rear-foot strike (RFS) running, employing a FFS is associated with heightened triceps surae muscle activation and ankle mechanical demand. Novice to this pattern, it is plausible that habitually shod RFS runners exhibit fatigue to the triceps surae when acutely transitioning to barefoot running, thereby limiting their ability to attenuate impact. Therefore, the purpose was to determine how habitually shod RFS runners respond to an exertion bout of barefoot running, operationally defined as a barefoot run 20% of mean daily running distance. Twenty-one RFS runners performed novice barefoot running, before and after exertion. Ankle peak torque, triceps surae EMG median frequency, foot-strike patterns, joint energy absorption, and loading rates were evaluated. Of the 21 runners, 6 maintained a RFS, 10 adopted a mid-foot strike (MFS), and 5 adopted a FFS during novice barefoot running. In-response to exertion, MFS and FFS runners demonstrated reductions in peak torque, median frequency, and ankle energy absorption, and an increase in loading rate. RFS runners demonstrated reductions in peak torque and loading rate. These results indicate that a short bout of running may elicit fatigue to novice barefoot runners, limiting their ability to attenuate impact. Key pointsIn response to exertion, novice barefoot runners demonstrate fatigue to their soleus.In response to exertion, novice barefoot runners demonstrate a reduction in ankle energy absorptionIn response to exertion, novice barefoot runners demonstrate an increase in loading rate.

A single bout of meditation biases cognitive control but not attentional focusing: Evidence from the global-local task.

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Colzato, Lorenza S; van der Wel, Pauline; Sellaro, Roberta; Hommel, Bernhard

2016-01-01

Recent studies show that a single bout of meditation can impact information processing. We were interested to see whether this impact extends to attentional focusing and the top-down control over irrelevant information. Healthy adults underwent brief single bouts of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing a global-local task. While the size of the global-precedence effect (reflecting attentional focusing) was unaffected by type of meditation, the congruency effect (indicating the failure to suppress task-irrelevant information) was considerably larger after OMM than after FAM. Our findings suggest that engaging in particular kinds of meditation creates particular cognitive-control states that bias the individual processing style toward either goal-persistence or cognitive flexibility. Copyright © 2015 Elsevier Inc. All rights reserved.

Segmentation and Characterization of Chewing Bouts by Monitoring Temporalis Muscle Using Smart Glasses With Piezoelectric Sensor.

Science.gov (United States)

Farooq, Muhammad; Sazonov, Edward

2017-11-01

Several methods have been proposed for automatic and objective monitoring of food intake, but their performance suffers in the presence of speech and motion artifacts. This paper presents a novel sensor system and algorithms for detection and characterization of chewing bouts from a piezoelectric strain sensor placed on the temporalis muscle. The proposed data acquisition device was incorporated into the temple of eyeglasses. The system was tested by ten participants in two part experiments, one under controlled laboratory conditions and the other in unrestricted free-living. The proposed food intake recognition method first performed an energy-based segmentation to isolate candidate chewing segments (instead of using epochs of fixed duration commonly reported in research literature), with the subsequent classification of the segments by linear support vector machine models. On participant level (combining data from both laboratory and free-living experiments), with ten-fold leave-one-out cross-validation, chewing were recognized with average F-score of 96.28% and the resultant area under the curve was 0.97, which are higher than any of the previously reported results. A multivariate regression model was used to estimate chew counts from segments classified as chewing with an average mean absolute error of 3.83% on participant level. These results suggest that the proposed system is able to identify chewing segments in the presence of speech and motion artifacts, as well as automatically and accurately quantify chewing behavior, both under controlled laboratory conditions and unrestricted free-living.

Effects of an Acute Exercise Bout on Serum Hepcidin Levels

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Raúl Domínguez

2018-02-01

Full Text Available Iron deficiency is a frequent and multifactorial disorder in the career of athletes, particularly in females. Exercise-induced disturbances in iron homeostasis produce deleterious effects on performance and adaptation to training; thus, the identification of strategies that restore or maintain iron homeostasis in athletes is required. Hepcidin is a liver-derived hormone that degrades the ferroportin transport channel, thus reducing the ability of macrophages to recycle damaged iron, and decreasing iron availability. Although it has been suggested that the circulating fraction of hepcidin increases during early post-exercise recovery (~3 h, it remains unknown how an acute exercise bout may modify the circulating expression of hepcidin. Therefore, the current review aims to determine the post-exercise expression of serum hepcidin in response to a single session of exercise. The review was carried out in the Dialnet, Elsevier, Medline, Pubmed, Scielo and SPORTDiscus databases, using hepcidin (and “exercise” or “sport” or “physical activity” as a strategy of search. A total of 19 articles were included in the review after the application of the inclusion/exclusion criteria. This search found that a single session of endurance exercise (intervallic or continuous at moderate or vigorous intensity (60–90% VO2peak stimulates an increase in the circulating levels of hepcidin between 0 h and 6 h after the end of the exercise bout, peaking at ~3 h post-exercise. The magnitude of the response of hepcidin to exercise seems to be dependent on the pre-exercise status of iron (ferritin and inflammation (IL-6. Moreover, oxygen disturbances and the activation of a hypoxia-induced factor during or after exercise may stimulate a reduction of hepcidin expression. Meanwhile, cranberry flavonoids supplementation promotes an anti-oxidant effect that may facilitate the post-exercise expression of hepcidin. Further studies are required to explore the effect

Ambulatory blood pressure response to a bout of HIIT in metabolic syndrome patients

OpenAIRE

Ramirez-Jimenez, Miguel; Morales Palomo, Felix Alberto; García-Pallarés, J.; Mora-Rodríguez, Ricardo; Ortega, Juan Fernando

2017-01-01

The effectiveness of exercise to lower blood pressure may depend on the type and intensity of exercise. We study the short-term (i.e., 14-hour) effects of a bout of high-intensity aerobic interval training (HIIT) on blood pressure in metabolic syndrome (MSyn) patients. Methods: Nineteen MSyn patients (55.2±7.3 years, 6 women) entered the study. Eight of them were normotensive and eleven hypertensive according to MSyn threshold (≥130 mmHg for SBP and/or ≥85 mmHg for DBP). In the...

Effects of a Single Bout of Resistance Exercise in Different Volumes on Endothelium Adaptations in Healthy Animals

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Marcelo Mendonça Mota

Full Text Available Abstract Background: Resistance exercise (RE has been recommended for patients with cardiovascular diseases. Recently, a few studies have demonstrated that the intensity of a single bout of RE has an effect on endothelial adaptations to exercise. However, there is no data about the effects of different volumes of RE on endothelium function. Objective: The aim of the study was to evaluate the effects of different volumes of RE in a single bout on endothelium-dependent vasodilatation and nitric oxide (NO synthesis in the mesenteric artery of healthy animals. Methods: Male Wistar rats were divided into three groups: Control (Ct; low-volume RE (LV, 5 sets x 10 repetitions and high-volume RE (HV, 15 sets x 10 repetitions. The established intensity was 70% of the maximal repetition test. After the exercise protocol, rings of mesenteric artery were used for assessment of vascular reactivity, and other mesenteric arteries were prepared for detection of measure NO production by DAF-FM fluorescence. Insulin responsiveness on NO synthesis was evaluated by stimulating the vascular rings with insulin (10 nM. Results: The maximal relaxation response to insulin increased in the HV group only as compared with the Ct group. Moreover, the inhibition of nitric oxide synthesis (L-NAME completely abolished the insulin-induced vasorelaxation in exercised rats. NO production showed a volume-dependent increase in the endothelial and smooth muscle layer. In endothelial layer, only Ct and LV groups showed a significant increase in NO synthesis when compared to their respective group under basal condition. On the other hand, in smooth muscle layer, NO fluorescence increased in all groups when compared to their respective group under basal condition. Conclusions: Our results suggest that a single bout of RE promotes vascular endothelium changes in a volume-dependent manner. The 15 sets x 10 repetitions exercise plan induced the greatest levels of NO synthesis.

Expectations affect psychological and neurophysiological benefits even after a single bout of exercise.

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Mothes, Hendrik; Leukel, Christian; Jo, Han-Gue; Seelig, Harald; Schmidt, Stefan; Fuchs, Reinhard

2017-04-01

The study investigated whether typical psychological, physiological, and neurophysiological changes from a single exercise are affected by one's beliefs and expectations. Seventy-six participants were randomly assigned to four groups and saw different multimedia presentations suggesting that the subsequent exercise (moderate 30 min cycling) would result in more or less health benefits (induced expectations). Additionally, we assessed habitual expectations reflecting previous experience and beliefs regarding exercise benefits. Participants with more positive habitual expectations consistently demonstrated both greater psychological benefits (more enjoyment, mood increase, and anxiety reduction) and greater increase of alpha-2 power, assessed with electroencephalography. Manipulating participants' expectations also resulted in largely greater increases of alpha-2 power, but not in more psychological exercise benefits. On the physiological level, participants decreased their blood pressure after exercising, but this was independent of their expectations. These results indicate that habitual expectations in particular affect exercise-induced psychological and neurophysiological changes in a self-fulfilling manner.

Associations of sedentary behavior, sedentary bouts and breaks in sedentary time with cardiometabolic risk in children with a family history of obesity.

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Travis John Saunders

Full Text Available Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children.To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8-11 years with a family history of obesity.Data from 286 boys and 236 girls living in Quebec, Canada, with at least one biological parent with obesity (QUALITY cohort were collected from 2005-2008, and analyzed in 2013. Sedentary behavior, light and moderate-to-vigorous physical activity were measured over 7 days using accelerometry. Leisure time computer/video game use and TV viewing over the past 7 days were self-reported. Outcomes included waist circumference, body mass index Z-score, fasting insulin, fasting glucose, triglycerides, HDL-cholesterol, C-reactive protein and a continuous cardiometabolic risk score.After adjustment for confounders, breaks in sedentary time and the number of sedentary bouts lasting 1-4 minutes were associated with reduced cardiometabolic risk score and lower BMI Z-score in both sexes (all p<0.05. The number of sedentary bouts lasting 5-9 minutes was negatively associated with waist circumference in girls only, while the number of bouts lasting 10-14 minutes was positively associated with fasting glucose in girls, and with BMI Z-score in boys (all p<0.05. Leisure time computer/video game use was associated with increased cardiometabolic risk score and waist circumference in boys, while TV viewing was associated with increased cardiometabolic risk, waist circumference, and BMI Z-score in girls (all p<0.05.These results suggest that frequent interruptions in sedentary time are associated with a favourable cardiometabolic risk profile and highlight the deleterious relationship between screen time and cardiometabolic risk among children with a family

Shortening Anesthesia Duration does not Affect Severity of Withdrawal Syndrome in Patients Undergoing Ultra Rapid Opioid Detoxification

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Shoaleh Shami

2010-02-01

Full Text Available Ultra rapid opioid detoxification (UROD is one of the new methods of detoxification. This method of detoxification involves putting patients under general anesthesia and actively giving them opioid antagonists. The objective of this study was to evaluate effects of anesthesia duration in UROD on severity of withdrawal syndrome. Sixty addicted patients seeking UROD procedure assigned randomly to one of the 2hr, 4hr or 6hr anesthesia duration groups. Premedication and anesthesia procedure (induction and maintenance were the same for three groups. Detoxification was done for all patients with 50 mg oral naltroxane (prior to induction and 20 mg intravenous naloxane (8 mg/bolus and 12 mg/infusion. Blood pressure, heart rate and respiratory rate were automatically measured and recorded every 5 minutes. The severity of withdrawal syndrome was measured and recorded every one hour during anesthesia, 2hours post-anesthesia, and 12 and 24 hours following the induction of anesthesia according to the Wang Scale modified by Lomier (WSMBL. Patients aged 20-58 in three groups. Three cases experienced delirium after detoxification that lasted 24 hours in one. Severity of withdrawal syndrome in patients of groups 2, 4 and 6 hour were 8.7, 7.4 and 5.1 respectively during anesthesia and 12.3, 11.1 and 13.9 after 18 hours of anesthesia. Results of this study showed that, in standard settings, UROD is a safe method for detoxification and has low complications. The withdrawal symptoms during and after anesthesia are low. Shortening the duration of anesthesia has no affect on severity of withdrawal syndrome during and after anesthesia.

Endothelial glycocalyx integrity is preserved in young, healthy men during a single bout of strenuous physical exercise.

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Majerczak, J; Duda, K; Chlopicki, S; Bartosz, G; Zakrzewska, A; Balcerczyk, A; Smoleński, R T; Zoladz, J A

2016-06-20

In the present study we aimed to evaluate whether oxidative stress and inflammation induced by strenuous exercise affect glycocalyx integrity and endothelial function. Twenty one young, untrained healthy men performed a maximal incremental cycling exercise - until exhaustion. Markers of glycocalyx shedding (syndecan-1, heparan sulfate and hyaluronic acid), endothelial status (nitric oxide and prostacyclin metabolites - nitrate, nitrite, 6-keto-prostaglandin F(1alpha)), oxidative stress (8-oxo-2'-deoxyguanosine) and antioxidant capacity (uric acid, non-enzymatic antioxidant capacity) as well as markers of inflammation (sVCAM-1 and sICAM-1) were analyzed in venous blood samples taken at rest and at the end of exercise. The applied strenuous exercise caused a 5-fold increase in plasma lactate and hypoxanthine concentrations (p<0.001), a fall in plasma uric acid concentration and non-enzymatic antioxidant capacity (p<10(-4)), accompanied by an increase (p=0.003) in sVCAM-1 concentration. Plasma 6-keto-prostaglandin F(1alpha) concentration increased (p=0.006) at exhaustion, while nitrate and nitrite concentrations were not affected. Surprisingly, no significant changes in serum syndecan-1 and heparan sulfate concentrations were observed. We have concluded, that a single bout of severe-intensity exercise is well accommodated by endothelium in young, healthy men as it neither results in evident glycocalyx disruption nor in the impairment of nitric oxide and prostacyclin production.

What Is the Effect on Obesity Indicators from Replacing Prolonged Sedentary Time with Brief Sedentary Bouts, Standing and Different Types of Physical Activity during Working Days? A Cross-Sectional Accelerometer-Based Study among Blue-Collar Workers

OpenAIRE

Gupta, Nidhi; Heiden, Marina; Aadahl, Mette; Korsh?j, Mette; J?rgensen, Marie Birk; Holtermann, Andreas

2016-01-01

INTRODUCTION: The aim of the study was to investigate if (a) substituting total sedentary time or long sedentary bouts with standing or various types of physical activity and (b) substituting long sedentary bouts with brief sedentary bouts; is associated with obesity indicators using a cross sectional isotemporal substitution approach among blue-collar workers.METHODS: A total of 692 workers from transportation, manufacturing and cleaning sectors wore an Actigraph GT3X+ accelerometer on the t...

Adaptation and Retention of a Perceptual-Motor Task in Children: Effects of a Single Bout of Intense Endurance Exercise.

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Ferrer-Uris, Blai; Busquets, Albert; Angulo-Barroso, Rosa

2018-02-01

We assessed the effect of an acute intense exercise bout on the adaptation and consolidation of a visuomotor adaptation task in children. We also sought to assess if exercise and learning task presentation order could affect task consolidation. Thirty-three children were randomly assigned to one of three groups: (a) exercise before the learning task, (b) exercise after the learning task, and (c) only learning task. Baseline performance was assessed by practicing the learning task in a 0° rotation condition. Afterward, a 60° rotation-adaptation set was applied followed by three rotated retention sets after 1 hr, 24 hr, and 7 days. For the exercise groups, exercise was presented before or after the motor adaptation. Results showed no group differences during the motor adaptation while exercise seemed to enhance motor consolidation. Greater consolidation enhancement was found in participants who exercised before the learning task. Our data support the importance of exercise to improve motor-memory consolidation in children.

Oxidative stress in patients with type 1 diabetes mellitus: is it affected by a single bout of prolonged exercise?

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Francescato, Maria Pia; Stel, Giuliana; Geat, Mario; Cauci, Sabina

2014-01-01

Presently, no clear-cut guidelines are available to suggest the more appropriate physical activity for patients with type 1 diabetes mellitus due to paucity of experimental data obtained under patients' usual life conditions. Accordingly, we explored the oxidative stress levels associated with a prolonged moderate intensity, but fatiguing, exercise performed under usual therapy in patients with type 1 diabetes mellitus and matched healthy controls. Eight patients (4 men, 4 women; 49±11 years; Body Mass Index 25.0±3.2 kg·m(-2); HbA1c 57±10 mmol·mol(-1)) and 14 controls (8 men, 6 women; 47±11 years; Body Mass Index 24.3±3.3 kg·m(-2)) performed a 3-h walk at 30% of their heart rate reserve. Venous blood samples were obtained before and at the end of the exercise for clinical chemistry analysis and antioxidant capacity. Capillary blood samples were taken at the start and thereafter every 30 min to determine lipid peroxidation. Patients showed higher oxidative stress values as compared to controls (95.9±9.7 vs. 74.1±12.2 mg·L(-1) H2O2; pexercise (p = NS), while oxidative defence increased significantly at the end of exercise (pdiabetes exercising under their usual life conditions (i.e. usual therapy and diet). Specifically, we found that the oxidative stress was not exacerbated due to a single bout of prolonged moderate intensity aerobic exercise, a condition simulating several outdoor leisure time physical activities. Oxidative defence increased in both patients and controls, suggesting beneficial effects of prolonged aerobic fatiguing exercise.

Factors affecting perception thresholds of vertical whole-body vibration in recumbent subjects: Gender and age of subjects, and vibration duration

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Matsumoto, Y.; Maeda, S.; Iwane, Y.; Iwata, Y.

2011-04-01

Some factors that may affect human perception thresholds of the vertical whole-body vibrations were investigated in two laboratory experiments with recumbent subjects. In the first experiment, the effects of gender and age of subjects on perception were investigated with three groups of 12 subjects, i.e., young males, young females and old males. For continuous sinusoidal vibrations at 2, 4, 8, 16, 31.5 and 63 Hz, there were no significant differences in the perception thresholds between male and female subjects, while the thresholds of young subjects tended to be significantly lower than the thresholds of old subjects. In the second experiment, the effect of vibration duration was investigated by using sinusoidal vibrations, at the same frequencies as above, modulated by the Hanning windows with different lengths (i.e., 0.5, 1.0, 2.0 and 4.0 s) for 12 subjects. It was found that the peak acceleration at the threshold tended to decrease with increasing duration of vibration. The perception thresholds were also evaluated by the running root-mean-square (rms) acceleration and the fourth power acceleration method defined in the current standards. The differences in the threshold of the transient vibrations for different durations were less with the fourth power acceleration method. Additionally, the effect of the integration time on the threshold was investigated for the running rms acceleration and the fourth power acceleration. It was found that the integration time that yielded less differences in the threshold of vibrations for different durations depended on the frequency of vibration.

Do changes in regulation affect employment duration in temporary help agencies?

DEFF Research Database (Denmark)

Antoni, Manfred; Jahn, Elke

2009-01-01

The employment duration of workers in temporary help agencies is seen as an important indicator of their job quality. Most of the countries that regulate temporary agency employment do so to insure at least a minimal level of employment stability. Over the past three decades Germany has repeatedly...

How Changes in Unemployment Benefit Duration Affect the Inflow Into Unemployment

NARCIS (Netherlands)

van Ours, J.C.; Tuit, S.

2010-01-01

We study how changes in the maximum benefit duration affec the inow into unemployment in the Netherlands. Until August 2003, workers who became un- employed after age 57.5 were entitled to unemployment benefits until the age of 65, after which they would receive old age pensions. This characteristic

Rent control and unemployment duration

DEFF Research Database (Denmark)

Svarer, Michael; Rosholm, Michael; Munch, Jakob Roland

2005-01-01

In this paper we analyse how rent control affects the duration of individual unemployment. In atheoretical search model we distinguish between two effects of rent control. On one hand, rentcontrol reduces housing mobility and hence mobility in the labour market. On the other hand, tomaintain rent...

A single exercise bout and locomotor learning after stroke: physiological, behavioural, and computational outcomes.

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Charalambous, Charalambos C; Alcantara, Carolina C; French, Margaret A; Li, Xin; Matt, Kathleen S; Kim, Hyosub E; Morton, Susanne M; Reisman, Darcy S

2018-05-15

Previous work demonstrated an effect of a single high-intensity exercise bout coupled with motor practice on the retention of a newly acquired skilled arm movement, in both neurologically intact and impaired adults. In the present study, using behavioural and computational analyses we demonstrated that a single exercise bout, regardless of its intensity and timing, did not increase the retention of a novel locomotor task after stroke. Considering both present and previous work, we postulate that the benefits of exercise effect may depend on the type of motor learning (e.g. skill learning, sensorimotor adaptation) and/or task (e.g. arm accuracy-tracking task, walking). Acute high-intensity exercise coupled with motor practice improves the retention of motor learning in neurologically intact adults. However, whether exercise could improve the retention of locomotor learning after stroke is still unknown. Here, we investigated the effect of exercise intensity and timing on the retention of a novel locomotor learning task (i.e. split-belt treadmill walking) after stroke. Thirty-seven people post stroke participated in two sessions, 24 h apart, and were allocated to active control (CON), treadmill walking (TMW), or total body exercise on a cycle ergometer (TBE). In session 1, all groups exercised for a short bout (∼5 min) at low (CON) or high (TMW and TBE) intensity and before (CON and TMW) or after (TBE) the locomotor learning task. In both sessions, the locomotor learning task was to walk on a split-belt treadmill in a 2:1 speed ratio (100% and 50% fast-comfortable walking speed) for 15 min. To test the effect of exercise on 24 h retention, we applied behavioural and computational analyses. Behavioural data showed that neither high-intensity group showed greater 24 h retention compared to CON, and computational data showed that 24 h retention was attributable to a slow learning process for sensorimotor adaptation. Our findings demonstrated that acute exercise

Effect of core body temperature, time of day, and climate conditions on behavioral patterns of lactating dairy cows experiencing mild to moderate heat stress.

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Allen, J D; Hall, L W; Collier, R J; Smith, J F

2015-01-01

Cattle show several responses to heat load, including spending more time standing. Little is known about what benefit this may provide for the animals. Data from 3 separate cooling management trials were analyzed to investigate the relationship between behavioral patterns in lactating dairy cows experiencing mild to moderate heat stress and their body temperature. Cows (n=157) were each fitted with a leg data logger that measured position and an intravaginal data logger that measures core body temperature (CBT). Ambient conditions were also collected. All data were standardized to 5-min intervals, and information was divided into several categories: when standing and lying bouts were initiated and the continuance of each bout (7,963 lying and 6,276 standing bouts). In one location, cows were continuously subjected to heat-stress levels according to temperature-humidity index (THI) range (THI≥72). The THI range for the other 2 locations was below and above a heat-stress threshold of 72 THI. Overall and regardless of period of day, cows stood up at greater CBT compared with continuing to stand or switching to a lying position. In contrast, cows lay down at lower CBT compared with continuing to lie or switching to a standing position, and lying bouts lasted longer when cows had lower CBT. Standing bouts also lasted longer when cattle had greater CBT, and they were less likely to lie down (less than 50% of lying bouts initiated) when their body temperature was over 38.8°C. Also, cow standing behavior was affected once THI reached 68. Increasing CBT decreased lying duration and increased standing duration. A CBT of 38.93°C marked a 50% likelihood a cow would be standing. This is the first physiological evidence that standing may help cool cows and provides insight into a communally observed behavioral response to heat. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

High-intensity interval training: Modulating interval duration in overweight/obese men.

Science.gov (United States)

Smith-Ryan, Abbie E; Melvin, Malia N; Wingfield, Hailee L

2015-05-01

High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations. In a randomized controlled pilot design, we evaluated the effects of two types of interval training protocols, varying in intensity and interval duration, on clinical outcomes in overweight/obese men. Twenty-five men [body mass index (BMI) > 25 kg · m(2)] completed baseline body composition measures: fat mass (FM), lean mass (LM) and percent body fat (%BF) and fasting blood glucose, lipids and insulin (IN). A graded exercise cycling test was completed for peak oxygen consumption (VO2peak) and power output (PO). Participants were randomly assigned to high-intensity short interval (1MIN-HIIT), high-intensity interval (2MIN-HIIT) or control groups. 1MIN-HIIT and 2MIN-HIIT completed 3 weeks of cycling interval training, 3 days/week, consisting of either 10 × 1 min bouts at 90% PO with 1 min rests (1MIN-HIIT) or 5 × 2 min bouts with 1 min rests at undulating intensities (80%-100%) (2MIN-HIIT). There were no significant training effects on FM (Δ1.06 ± 1.25 kg) or %BF (Δ1.13% ± 1.88%), compared to CON. Increases in LM were not significant but increased by 1.7 kg and 2.1 kg for 1MIN and 2MIN-HIIT groups, respectively. Increases in VO2peak were also not significant for 1MIN (3.4 ml·kg(-1) · min(-1)) or 2MIN groups (2.7 ml · kg(-1) · min(-1)). IN sensitivity (HOMA-IR) improved for both training groups (Δ-2.78 ± 3.48 units; p < 0.05) compared to CON. HIIT may be an effective short-term strategy to improve cardiorespiratory fitness and IN sensitivity in overweight males.

Effect of a 1-hour single bout of moderate-intensity exercise on fat oxidation kinetics.

Science.gov (United States)

Chenevière, Xavier; Borrani, Fabio; Ebenegger, Vincent; Gojanovic, Boris; Malatesta, Davide

2009-12-01

The present study aimed to examine the effects of a prior 1-hour continuous exercise bout (CONT) at an intensity (Fat(max)) that elicits the maximal fat oxidation (MFO) on the fat oxidation kinetics during a subsequent submaximal incremental test (IncrC). Twenty moderately trained subjects (9 men and 11 women) performed a graded test on a treadmill (Incr), with 3-minute stages and 1-km.h(-1) increments. Fat oxidation was measured using indirect calorimetry and plotted as a function of exercise intensity. A mathematical model (SIN) including 3 independent variables (dilatation, symmetry, and translation) was used to characterize the shape of fat oxidation kinetics and to determine Fat(max) and MFO. On a second visit, the subjects performed CONT at Fat(max) followed by IncrC. After CONT performed at 57% +/- 3% (means +/- SE) maximal oxygen uptake (Vo(2max)), the respiratory exchange ratio during IncrC was lower at every stage compared with Incr (P rates from 35% to 70% Vo(2max) (P .05), whereas symmetry tended to be greater in IncrC (P = .096). This study showed that the prior 1-hour continuous moderate-intensity exercise bout increased Fat(max), MFO, and fat oxidation rates over a wide range of intensities during the postexercise incremental test. Moreover, the shape of the postexercise fat oxidation kinetics tended to have a rightward asymmetry.

A preliminary examination of neurocognitive performance and symptoms following a bout of soccer heading in athletes wearing protective soccer headbands.

Science.gov (United States)

Elbin, R J; Beatty, Amanda; Covassin, Tracey; Schatz, Philip; Hydeman, Ana; Kontos, Anthony P

2015-01-01

This study compared changes in neurocognitive performance and symptom reports following an acute bout of soccer heading among athletes with and without protective soccer headgear. A total of 25 participants headed a soccer ball 15 times over a 15-minute period, using a proper linear heading technique. Participants in the experimental group completed the heading exercise while wearing a protective soccer headband and controls performed the heading exercise without wearing the soccer headband. Neurocognitive performance and symptom reports were assessed before and after the acute bout of heading. Participants wearing the headband showed significant decreases on verbal memory (p = 0.02) compared with the no headband group, while the no headband group demonstrated significantly faster reaction time (p = 0.03) than the headband group following the heading exercise. These findings suggest that protective soccer headgear likely does not mitigate the subtle neurocognitive effects of acute soccer heading.

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise.

Science.gov (United States)

Beneka, Anastasia G; Malliou, Paraskevi K; Missailidou, Victoria; Chatzinikolaou, Athanasios; Fatouros, Ioannis; Gourgoulis, Vassilios; Georgiadis, Elias

2013-01-01

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90-95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.

Accelerometer-Derived Pattern of Sedentary and Physical Activity Time in Persons with Mobility Disability: National Health and Nutrition Examination Survey 2003 to 2006.

Science.gov (United States)

Manns, Patricia; Ezeugwu, Victor; Armijo-Olivo, Susan; Vallance, Jeff; Healy, Genevieve N

2015-07-01

To describe objectively determined sedentary and activity outcomes (volume and pattern) and their associations with cardiometabolic risk biomarkers in individuals with and without mobility disability. Cross-sectional. Population based. Community-dwelling older adults (≥60) living in the United States who were participants in the 2003 to 2004 or 2005 to 2006 National Health and Nutrition Examination Survey. Participants were classified as with or without mobility disability according to responses to self-reported questions about ability to walk, climb stairs, and/or use of ambulatory aids. Accelerometer-derived sedentary and activity variables for volume (time in sedentary (activity and pattern (number of breaks from sedentary time, duration of sedentary bouts, duration of activity bouts). Survey-weighted regression models, adjusted for age, sex, ethnicity, education, and smoking, were used to examine the associations between pattern of activity and cardiometabolic health risk factors (blood pressure, waist circumference, high-density lipoprotein cholesterol). Of the 2,017 participants, 547 were classified as having a mobility disability. Participants with mobility disability had more sedentary time and less active time than those without. Sedentary bouts were longer and active bouts shorter in those with disability. The total number of sedentary breaks (transitions from sedentary to nonsedentary) differed between groups after adjustment for total sedentary time. Fewer breaks, longer sedentary bouts, and shorter activity bouts were associated with higher average waist circumference regardless of disability status. This study provides rationale for the development and testing of interventions to change the pattern of activity (e.g., include more breaks and longer activity bout durations) in older adults with mobility disability. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Similar acute physiological responses from effort and duration matched leg press and recumbent cycling tasks

Directory of Open Access Journals (Sweden)

James Steele

2018-02-01

Full Text Available The present study examined the effects of exercise utilising traditional resistance training (leg press or ‘cardio’ exercise (recumbent cycle ergometry modalities upon acute physiological responses. Nine healthy males underwent a within session randomised crossover design where they completed both the leg press and recumbent cycle ergometer conditions. Conditions were approximately matched for effort and duration (leg press: 4 × 12RM using a 2 s concentric and 3 s eccentric repetition duration controlled with a metronome, thus each set lasted  60 s; recumbent cycle ergometer: 4 × 60 s bouts using a resistance level permitting 80–100 rpm but culminating with being unable to sustain the minimum cadence for the final 5–10 s. Measurements included VO2, respiratory exchange ratio (RER, blood lactate, energy expenditure, muscle swelling, and electromyography. Perceived effort was similar between conditions and thus both were well matched with respect to effort. There were no significant effects by ‘condition’ in any of the physiological responses examined (all p > 0.05. The present study shows that, when both effort and duration are matched, resistance training (leg press and ‘cardio’ exercise (recumbent cycle ergometry may produce largely similar responses in VO2, RER, blood lactate, energy expenditure, muscle swelling, and electromyography. It therefore seems reasonable to suggest that both may offer a similar stimulus to produce chronic physiological adaptations in outcomes such as cardiorespiratory fitness, strength, and hypertrophy. Future work should look to both replicate the study conducted here with respect to the same, and additional physiological measures, and rigorously test the comparative efficacy of effort and duration matched exercise of differing modalities with respect to chronic improvements in physiological fitness.

ALTERATION OF MUSCLE FUNCTION AFTER ELECTRICAL STIMULATION BOUT OF KNEE EXTENSORS AND FLEXORS

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Marc Vanderthommen

2012-12-01

Full Text Available The purpose was to study the effects on muscle function of an electrical stimulation bout applied unilaterally on thigh muscles in healthy male volunteers. One group (ES group, n = 10 received consecutively 100 isometric contractions of quadriceps and 100 isometric contractions of hamstrings (on-off ratio 6-6 s induced by neuromuscular electrical stimulations (NMES. Changes in muscle torque, muscle soreness (0-10 VAS, muscle stiffness and serum creatine kinase (CK activity were assessed before the NMES exercise (pre-ex as well as 24h (d+1, 48h (d+2 and 120h (d+5 after the bout. A second group (control group, n = 10 were submitted to the same test battery than the ES group and with the same time-frame. The between-group comparison indicated a significant increase in VAS scores and in serum levels of CK only in the ES group. In the ES group, changes were more pronounced in hamstrings than in quadriceps and peaked at d+2 (quadriceps VAS scores = 2.20 ± 1.55 a.u. (0 at pre-ex; hamstrings VAS scores = 3.15 ± 2.14 a.u. (0 at pre-ex; hip flexion angle = 62 ± 5° (75 ± 6° at pre-ex; CK activity = 3021 ± 2693 IU·l-1 (136 ± 50 IU·l-1 at pre-ex. The results of the present study suggested the occurrence of muscle damage that could have been induced by the peculiar muscle recruitment in NMES and the resulting overrated mechanical stress. The sensitivity to the damaging effects of NMES appeared higher in the hamstrings than in quadriceps muscles

The skeletal muscle satellite cell response to a single bout of resistance-type exercise is delayed with aging in men

NARCIS (Netherlands)

Snijders, T.; Verdijk, L.B.; Smeets, J.S.J.; McKay, B.R.; Senden, J.M.G.; Hartgens, F.; Parise, G.; Greenhaff, P.; van Loon, L.J.C.

2014-01-01

Skeletal muscle satellite cells (SCs) have been shown to be instrumental in the muscle adaptive response to exercise. The present study determines age-related differences in SC content and activation status following a single bout of exercise. Ten young (22 +/- 1 years) and 10 elderly (73 +/- 1

Late Sleeping Affects Sleep Duration and Body Mass Index in Adolescents

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Rajesh G.Kathrotia1,

2010-03-01

Full Text Available During adolescence, there is a tendency to sleep late andsleep less because of altered psychosocial and life-stylechanges. Recent studies have demonstrated the link betweensleeping less and gaining weight in children, adolescents, andadults. We studied the effect of late sleeping and sleepingless on body mass index (BMI in medical college freshmen.All participants were adolescents (104 male and 38 femaleadolescents, mean age 17.77±0.79 years. After obtaininginformed consent, they filled out a questionnaire about theirsleeping habits. Height and weight were measured after abrief history taking and clinical examination. BMI increasedsignificantly with decrease in total sleep duration and withdelayed bedtime. Late sleeping individuals (after midnighthad significantly less sleep duration (6.78 hours v 7.74 hours,P<0.001, more day time sleepiness (85.2% v 69.3%,P=0.033 and more gap between dinner time and going tosleep (234.16 min v 155.45 min, P<0.001. Increased BMI inlate sleepers may be explained by low physical activity duringthe day caused by excess sleepiness and increased calorieintake with a gap of 5-6 hours between dinner and sleep.Sleep habits of late sleeping and sleeping less contribute toincrease BMI in adolescents.

Psychological and Physiological Biomarkers of Neuromuscular Fatigue after Two Bouts of Sprint Interval Exercise

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Albertas Skurvydas

2017-12-01

Full Text Available The main aim of our study was to determinate whether a repeated bout (RB (vs. first bout [FB] of sprint interval cycling exercise (SIE is sufficient to mitigate SIE-induced psychological and physiological biomarker kinetics within 48 h after the exercise. Ten physically active men (age, 22.6 ± 5.2 years; VO2max, 44.3 ± 5.7 ml/kg/min performed the FB of SIE (12 repeats of 5 s each on one day and the RB 2 weeks later. The following parameters were measured: motor performance (voluntary, electrically induced and isokinetic skeletal muscle contraction torque, and central activation ratio [CAR]; stress markers [brain-derived neurotrophic factor (BDNF, cortisol, norepinephrine, and epinephrine]; inflammatory markers (IL-6, IL-10, and TNF-α; metabolic markers (glucose and lactate; muscle and rectal temperature; cycling power output; and psychological perceptions. The average cycling power output and neuromuscular fatigue after exercise did not differ between the FB and RB. There were significant decreases in cortisol and BDNF concentration at 12 h (P < 0.05 and 24 h (P < 0.001 after the FB, respectively. The decrease in cortisol concentration observed 12 h after exercise was significantly greater after the RB (P < 0.05 than after the FB. The immune-metabolic response to the RB (vs. FB SIE was suppressed and accompanied by lower psychological exertion. Most of the changes in psychological and physiological biomarkers in the FB and RB were closely related to the response kinetics of changes in BDNF concentration.

Partial report and other sampling procedures overestimate the duration of iconic memory.

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Appelman, I B

1980-03-01

In three experiments, subjects estimated the duration of a brief visual image (iconic memory) either directly by adjusting onset of a click to offset of the visual image, or indirectly with a Sperling partial report (sampling) procedure. The results indicated that partial report and other sampling procedures may reflect other brief phenomena along with iconic memory. First, the partial report procedure yields a greater estimate of the duration of iconic memory than the more direct click method. Second, the partial report estimate of the duration of iconic memory is affected if the subject is required to simultaneously retain a list of distractor items (memory load), while the click method estimate of the duration of iconic memory is not affected by a memory load. Finally, another sampling procedure based on visual cuing yields different estimates of the duration of iconic memory depending on how many items are cued. It was concluded that partial report and other sampling procedures overestimate the duration of iconic memory.

Benefits for Type 2 Diabetes of Interrupting Prolonged Sitting With Brief Bouts of Light Walking or Simple Resistance Activities.

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Dempsey, Paddy C; Larsen, Robyn N; Sethi, Parneet; Sacre, Julian W; Straznicky, Nora E; Cohen, Neale D; Cerin, Ester; Lambert, Gavin W; Owen, Neville; Kingwell, Bronwyn A; Dunstan, David W

2016-06-01

To determine whether interrupting prolonged sitting with brief bouts of light-intensity walking (LW) or simple resistance activities (SRA) improves postprandial cardiometabolic risk markers in adults with type 2 diabetes (T2D). In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men 62 ± 6 years old) underwent the following 8-h conditions on three separate days (with 6-14 days washout): uninterrupted sitting (control) (SIT), sitting plus 3-min bouts of LW (3.2 km · h(-1)) every 30 min, and sitting plus 3-min bouts of SRA (half-squats, calf raises, gluteal contractions, and knee raises) every 30 min. Standardized meals were consumed during each condition. Incremental areas under the curve (iAUCs) for glucose, insulin, C-peptide, and triglycerides were compared between conditions. Compared with SIT, both activity-break conditions significantly attenuated iAUCs for glucose (SIT mean 24.2 mmol · h · L(-1) [95% CI 20.4-28.0] vs. LW 14.8 [11.0-18.6] and SRA 14.7 [10.9-18.5]), insulin (SIT 3,293 pmol · h · L(-1) [2,887-3,700] vs. LW 2,104 [1,696-2,511] and SRA 2,066 [1,660-2,473]), and C-peptide (SIT 15,641 pmol · h · L(-1) [14,353-16,929] vs. LW 11,504 [10,209-12,799] and SRA 11,012 [9,723-12,301]) (all P triglycerides was significantly attenuated for SRA (P triglyceride responses in adults with T2D. With poor adherence to structured exercise, this approach is potentially beneficial and practical. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

The effects of odor and body posture on perceived duration

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Schreuder, E.; Hoeksma, M.R.; Smeets, M.A.M.; Semin, G.R.

2014-01-01

This study reports an examination of the internal clock model, according to which subjective time duration is influenced by attention and arousal state. In a time production task, we examine the hypothesis that an arousing odor and an upright body posture affect perceived duration. The experimental

Écriture et dissidence dans les fictions spéculatives de Pascal Quignard : sur l´exemple de Boutès

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Patricia Martínez García

2013-04-01

Full Text Available In Boutès (2008 Pascal Quignard rescues the figure of this pre-Homeric neglected hero, hidden in one of the best known mythological legends, that of Ja-son and Argona, to which Apollonius of Rhodes only dedicates but a few lines. Contrary to Ulysses and Orpheus, Butes abandons the rowing and lets himself be carried away by the sirens’ chant. In Quignard´s opinion, he dissents from the exemplary model of the heroes that have founded our culture, and dissociates himself from the group that tries to enclose and domesticate the outcast. Based on Quignard´s reading of this myth, we propose an approach to his writing as a token of ethic and aesthetic dissidence, affecting different aspects: dissidence from prevailing models of socialization, dissi-dence from traditional literary forms and conventional genres, dissidence from meta-narratives and their linear vision of history, and finally, dissidence from modern conceptions of time and progress.

The effect of predictability on subjective duration.

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Vani Pariyadath

2007-11-01

Full Text Available Events can sometimes appear longer or shorter in duration than other events of equal length. For example, in a repeated presentation of auditory or visual stimuli, an unexpected object of equivalent duration appears to last longer. Illusions of duration distortion beg an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? In other words, what entailments do duration distortions have with respect to other timing judgments? We here show that when a sound or visual flicker is presented in conjunction with an unexpected visual stimulus, neither the pitch of the sound nor the frequency of the flicker is affected by the apparent duration dilation. This demonstrates that subjective time in general is not slowed; instead, duration judgments can be manipulated with no concurrent impact on other temporal judgments. Like spatial vision, time perception appears to be underpinned by a collaboration of separate neural mechanisms that usually work in concert but are separable. We further show that the duration dilation of an unexpected stimulus is not enhanced by increasing its saliency, suggesting that the effect is more closely related to prediction violation than enhanced attention. Finally, duration distortions induced by violations of progressive number sequences implicate the involvement of high-level predictability, suggesting the involvement of areas higher than primary visual cortex. We suggest that duration distortions can be understood in terms of repetition suppression, in which neural responses to repeated stimuli are diminished.

Collective behaviors of book holding durations

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Li, Ren-De; Guo, Qiang; Han, Jing-Ti; Liu, Jian-Guo

2016-10-01

Duration can directly reflect the collective reading behaviors of library user book holding. In this paper, by introducing the burstiness and memory coefficients, we empirically investigate the collective book holding behavior of three university libraries. The statistical results show that there are similar properties among the students with different backgrounds, presenting the burstiness = - 0.2 and memory = 0.5 for three datasets, which indicates that memory and random effects coexist in student book holding durations. In addition, we analyze the behavior patterns without duplicate durations by merging a series of books borrowed and returned at the same time. The results show the average burstiness B increases to -0.16 and memory M drops to 0.16 for three datasets, which indicates that both duplicate behavior and student's preference affect the memory effect. Furthermore, we present a model which assumes student's next book holding duration follows the previous one with probability p, and with probability 1 - p, the student would hold the book independently. The experimental results show that the presented model can reproduce the burstiness and memory effect of student book holding durations when p = 0.5 for empirical datasets and p = 0.2 for de-duplicate datasets, which indicate that the student's preferential holding behavior occurs with the probability p. This work helps in deeply understanding the regularity of duration-based human behaviors.

Active Recovery between Interval Bouts Reduces Blood Lactate While Improving Subsequent Exercise Performance in Trained Men

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Harutiun M. Nalbandian

2017-06-01

Full Text Available This study aimed to examine the blood lactate and blood pH kinetics during high-intensity interval training. Seventeen well-trained athletes exercised on two different occasions. Exercises consisted of three 30 s bouts at a constant intensity (90% of peak power with 4 min recovery between bouts followed by a Wingate test (WT. The recoveries were either active recovery (at 60% of the lactate threshold intensity or passive recovery (resting at sitting position. During the exercise, blood samples were taken to determine blood gasses, blood lactate, and blood pH, and peak and average power were calculated for the WT. When performing the active recovery trials, blood pH was significantly higher (p < 0.01 and blood lactate was significantly lower (p < 0.01 compared with the passive recovery trials. WT performance was significantly higher in the active recovery trials: peak power was 671 ± 88 and 715 ± 108 watts, and average power was 510 ± 70 and 548 ± 73 watts (passive and active respectively; p < 0.01. However, no statistically significant correlations were found between the increased pH and the increased performance in the active recovery trials. These results suggest that active recovery performed during high-intensity interval exercise favors the performance in a following WT. Moreover, the blood pH variations associated with active recovery did not explain the enhanced performance.

Analysis of the finescale timing of repeated signals: does shell rapping in hermit crabs signal stamina?

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Briffa; Elwood

2000-01-01

Hermit crabs, Pagurus bernhardus, sometimes exchange shells after a period of shell rapping, when the initiating or attacking crab brings its shell rapidly and repeatedly into contact with the shell of the noninitiator or defender in a series of bouts. Bouts are separated by pauses, and raps within bouts are separated by very short periods called 'gaps'. Since within-contest variation is missed when signals are studied by averaging performance rates over entire contests, we analysed the fine within-bout structure of this repeated, aggressive signal. We found that the pattern is consistent with high levels of fatigue in initiators. The duration of the gaps between individual raps increased both within bouts and from bout to bout, and we conclude that this activity is costly to perform. Furthermore, long pauses between bouts is correlated with increased vigour of rapping in the subsequent bout, which suggests that the pause allows for recovery from fatigue induced by rapping. These between-bout pauses may be assessed by noninitiators and provide a signal of stamina. Copyright 2000 The Association for the Study of Animal Behaviour.

Short-term memory for event duration: modality specificity and goal dependency.

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Takahashi, Kohske; Watanabe, Katsumi

2012-11-01

Time perception is involved in various cognitive functions. This study investigated the characteristics of short-term memory for event duration by examining how the length of the retention period affects inter- and intramodal duration judgment. On each trial, a sample stimulus was followed by a comparison stimulus, after a variable delay period (0.5-5 s). The sample and comparison stimuli were presented in the visual or auditory modality. The participants determined whether the comparison stimulus was longer or shorter than the sample stimulus. The distortion pattern of subjective duration during the delay period depended on the sensory modality of the comparison stimulus but was not affected by that of the sample stimulus. When the comparison stimulus was visually presented, the retained duration of the sample stimulus was shortened as the delay period increased. Contrarily, when the comparison stimulus was presented in the auditory modality, the delay period had little to no effect on the retained duration. Furthermore, whenever the participants did not know the sensory modality of the comparison stimulus beforehand, the effect of the delay period disappeared. These results suggest that the memory process for event duration is specific to sensory modality and that its performance is determined depending on the sensory modality in which the retained duration will be used subsequently.

Rats do not respond differently in the presence of stimuli signaling wheel-running reinforcers of different durations.

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Belke, Terry W

2007-05-01

Rats were exposed to a fixed interval 30 s schedule that produced opportunities to run of equal or unequal durations to assess the effect of differences in duration on responding. Each duration was signaled by a different stimulus. Wheel-running reinforcer duration pairs were 30 s 30 s, 50 s 10 s, and 55 s 5 s. An analysis of median postreinforcement pause duration and mean local lever-pressing rates broken down by previous reinforcer duration and duration of signaled upcoming reinforcer showed that postreinforcement pause duration was affected by the duration of the previous reinforcer but not by the stimulus signaling the duration of the upcoming reinforcer. Local lever-pressing rates were not affected by either previous or upcoming reinforcer duration. In general, the results are consistent with indifference between these durations obtained using a concurrent choice procedure.

Epigenetic basis of sensitization to stress, affective episodes, and stimulants: implications for illness progression and prevention.

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Post, Robert M

2016-06-01

The process of sensitization (increased responsivity) to the recurrence of stressors, affective episodes, and bouts of substance abuse that can drive illness progression in the recurrent affective disorders requires a memory of and increased reactivity to the prior exposures. A wealth of studies now supports the postulate that epigenetic mechanisms underlie both normal and pathological memory processes. We selectively reviewed the literature pertinent to the role of epigenetics in behavioral sensitization phenomena and discuss its clinical implications. Epigenetics means above genetics and refers to environmental effects on the chemistry of DNA, histones (around which DNA is wound), and microRNA that change how easily genes are turned on and off. The evidence supports that sensitization to repeated stressor, affective episodes, and substance is likely based on epigenetic mechanisms and that these environmentally based processes can then become targets for prevention, early intervention, and ongoing treatment. Sensitization processes are remediable or preventable risk factors for a poor illness outcome and deserve increased clinical, public health, and research attention in the hopes of making the recurrent unipolar and bipolar affective disorders less impairing, disabling, and lethal by suicide and increased medical mortality. The findings that epigenetic chemical marks, which change in the most fundamental way how genes are regulated, mediate the long-term increased responsivity to recurrent stressors, mood episodes, and bouts of substance abuse should help change how the affective disorders are conceptualized and move treatment toward earlier, more comprehensive, and sustained pharmacoprophylaxis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

To what extent might N2 limit dive performance in king penguins?

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Fahlman, A; Schmidt, A; Jones, D R; Bostrom, B L; Handrich, Y

2007-10-01

A mathematical model was used to explore if elevated levels of N2, and risk of decompression sickness (DCS), could limit dive performance (duration and depth) in king penguins (Aptenodytes patagonicus). The model allowed prediction of blood and tissue (central circulation, muscle, brain and fat) N2 tensions (P(N2)) based on different cardiac outputs and blood flow distributions. Estimated mixed venous P(N2) agreed with values observed during forced dives in a compression chamber used to validate the assumptions of the model. During bouts of foraging dives, estimated mixed venous and tissue P(N2) increased as the bout progressed. Estimated mean maximum mixed venous P(N2) upon return to the surface after a dive was 4.56+/-0.18 atmospheres absolute (ATA; range: 4.37-4.78 ATA). This is equivalent to N2 levels causing a 50% DCS incidence in terrestrial animals of similar mass. Bout termination events were not associated with extreme mixed venous N2 levels. Fat P(N2) was positively correlated with bout duration and the highest estimated fat P(N2) occurred at the end of a dive bout. The model suggested that short and shallow dives occurring between dive bouts help to reduce supersaturation and thereby DCS risk. Furthermore, adipose tissue could also help reduce DCS risk during the first few dives in a bout by functioning as a sink to buffer extreme levels of N2.

Auditory stimulus timing influences perceived duration of co-occurring visual stimuli

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Vincenzo eRomei

2011-09-01

Full Text Available There is increasing interest in multisensory influences upon sensory-specific judgements, such as when auditory stimuli affect visual perception. Here we studied whether the duration of an auditory event can objectively affect the perceived duration of a co-occurring visual event. On each trial, participants were presented with a pair of successive flashes and had to judge whether the first or second was longer. Two beeps were presented with the flashes. The order of short and long stimuli could be the same across audition and vision (audiovisual congruent or reversed, so that the longer flash was accompanied by the shorter beep and vice versa (audiovisual incongruent; or the two beeps could have the same duration as each other. Beeps and flashes could onset synchronously or asynchronously. In a further control experiment, the beep durations were much longer (tripled than the flashes. Results showed that visual duration-discrimination sensitivity (d' was significantly higher for congruent (and significantly lower for incongruent audiovisual synchronous combinations, relative to the visual only presentation. This effect was abolished when auditory and visual stimuli were presented asynchronously, or when sound durations tripled those of flashes. We conclude that the temporal properties of co-occurring auditory stimuli influence the perceived duration of visual stimuli and that this can reflect genuine changes in visual sensitivity rather than mere response bias.

Ingestion of 10 grams of whey protein prior to a single bout of resistance exercise does not augment Akt/mTOR pathway signaling compared to carbohydrate

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Cooke Matthew B

2011-11-01

Full Text Available Abstract Background This study examined the effects of a whey protein supplement in conjunction with an acute bout of lower body resistance exercise, in recreationally-active males, on serum insulin and insulin like growth factor 1 (IGF-1 and Akt/mTOR signaling markers indicative of muscle protein synthesis: insulin receptor substrate 1 (IRS-1, AKT, mammalian target of rapamycin (mTOR, p70S6 kinase (p70S6K and 4E-binding protein 1 (4E-BP1. Methods In a randomized, double-blind, cross-over design, 10 males ingested 1 week apart, either 10 g of whey protein (5.25 g EAAs or carbohydrate (maltodextrose, 30 min prior to a lower-body resistance exercise bout. The resistance exercise bout consisted of 4 sets of 8-10 reps at 80% of the one repetition maximum (RM on the angled leg press and knee extension exercises. Blood and muscle samples were obtained prior to, and 30 min following supplement ingestion and 15 min and 120 min post-exercise. Serum and muscle data were analyzed using two-way ANOVA. Results No significant differences were observed for IGF-1 (p > 0.05. A significant main effect for Test was observed for serum insulin (p 0.05. For the Akt/MTOR signaling intermediates, no significant Supplement × Test interactions were observed (p > 0.05. However, significant main effects for Test were observed for phosphorylated concentrations of IRS, mTOR, and p70S6K, as all were elevated at 15 min post-exercise (p Conclusion Ingestion of 10 g of whey protein prior to an acute bout of lower body resistance exercise had no significant preferential effect compared to carbohydrate on systemic and cellular signaling markers indicative of muscle protein synthesis in untrained individuals.

Evidence of sub-optimal sleep in adolescent Middle Eastern academy soccer players which is exacerbated by sleep intermission proximal to dawn.

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Fowler, Peter M; Paul, Darren J; Tomazoli, Gustavo; Farooq, Abdulaziz; Akenhead, Richard; Taylor, Lee

2017-10-01

The purpose was to assess sleep patterns, quantity and quality in adolescent (16.2 ± 1.2 yr) Middle Eastern academy soccer players (n = 20) and the influence of an intermission upon these characteristics. On a 17-day training camp (located one time zone west of home) including three discrete matches, sleep was assessed pre- (PRE) and post-match (POST) via wrist actigraphy. Retrospective actigraphy analysis identified sleep characteristics, including if players experienced a sleep intermission (YES) or not (NO) proximal to dawn, and bedtime (hh:mm), get-up time (hh:mm), time in bed (h), sleep duration (h) and sleep efficiency (%). Within YES two bouts were identified (BOUT1 and BOUT2). No differences were seen between PRE and POST, nor between BOUT1 and BOUT2 (p > .05). Overall players did not meet National Sleep Foundation (NSF) guidelines (7:04 ± 1:16 h vs. recommended 8-10 h for 14-17 yr). Sleep duration was significantly reduced (∼ -13% or -1:06) in YES compared to NO (6:33 ± 1:05 vs. 7:29 ± 1:17, p sleep durations relative to NSF guidelines, with decrements increased by an intermission proximal to dawn. High inter- and intra-individual variance in the players sleep characteristics indicates the need for individualized sleep education strategies and interventions to promote appropriate sleep.

Does Treatment Duration Affect Outcome After Radiotherapy for Prostate Cancer?

International Nuclear Information System (INIS)

D'Ambrosio, David J.; Li Tianyu; Horwitz, Eric M.; Chen, David Y.T.; Pollack, Alan; Buyyounouski, Mark K.

2008-01-01

Purpose: The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer. Methods and Materials: Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model. Results: The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR ≥33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR ≥33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined. Conclusions: A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of ≥33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided

Five-field simulations of peeling-ballooning modes using BOUT++ code

Energy Technology Data Exchange (ETDEWEB)

Xia, T. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2013-05-15

The simulations of edge localized modes (ELMs) with a 5-field peeling-ballooning (P-B) model using BOUT++ code are reported in this paper. In order to study the particle and energy transport in the pedestal region, the pressure equation is separated into ion density and ion and electron temperature equations. Through the simulations, the length scale L{sub n} of the gradient of equilibrium density n{sub i0} is found to destabilize the P-B modes in ideal MHD model. With ion diamagnetic effects, the growth rate is inversely proportional to n{sub i0} at medium toroidal mode number n. For the nonlinear simulations, the gradient of n{sub i0} in the pedestal region can more than double the ELM size. This increasing effect can be suppressed by thermal diffusivities χ{sub ∥}, employing the flux limited expression. Thermal diffusivities are sufficient to suppress the perturbations at the top of pedestal region. These suppressing effects lead to smaller ELM size of P-B modes.

Risk, treatment duration, and recurrence risk of postpartum affective disorder in women with no prior psychiatric history

DEFF Research Database (Denmark)

Rasmussen, Marie-Louise H; Strøm, Marin; Wohlfahrt, Jan

2017-01-01

BACKGROUND: Some 5%-15% of all women experience postpartum depression (PPD), which for many is their first psychiatric disorder. The purpose of this study was to estimate the incidence of postpartum affective disorder (AD), duration of treatment, and rate of subsequent postpartum AD and other...... total of 789,068 births) and no prior psychiatric hospital contacts and/or use of antidepressants. These women were followed from 1 January 1996 to 31 December 2014. Postpartum AD was defined as use of antidepressants and/or hospital contact for PPD within 6 months after childbirth. The main outcome.......4%. The recurrence risk of postpartum AD for women with a PPD hospital contact after first birth was 55.4 per 100 person-years; for women with postpartum antidepressant medication after first birth, it was 35.0 per 100 person-years. The rate of postpartum AD after second birth for women with no history of postpartum...

White-nose syndrome-affected little brown myotis (Myotis lucifugus) increase grooming and other active behaviors during arousals from hibernation.

Science.gov (United States)

Brownlee-Bouboulis, Sarah A; Reeder, DeeAnn M

2013-10-01

White-nose syndrome (WNS) is an emerging infectious disease of hibernating bats linked to the death of an estimated 5.7 million or more bats in the northeastern United States and Canada. White-nose syndrome is caused by the cold-loving fungus Pseudogymnoascus destructans (Pd), which invades the skin of the muzzles, ears, and wings of hibernating bats. Previous work has shown that WNS-affected bats arouse to euthermic or near euthermic temperatures during hibernation significantly more frequently than normal and that these too-frequent arousals are tied to severity of infection and death date. We quantified the behavior of bats during these arousal bouts to understand better the causes and consequences of these arousals. We hypothesized that WNS-affected bats would display increased levels of activity (especially grooming) during their arousal bouts from hibernation compared to WNS-unaffected bats. Behavior of both affected and unaffected hibernating bats in captivity was monitored from December 2010 to March 2011 using temperature-sensitive dataloggers attached to the backs of bats and infrared motion-sensitive cameras. The WNS-affected bats exhibited significantly higher rates of grooming, relative to unaffected bats, at the expense of time that would otherwise be spent inactive. Increased self-grooming may be related to the presence of the fungus. Elevated activity levels in affected bats likely increase energetic stress, whereas the loss of rest (inactive periods when aroused from torpor) may jeopardize the ability of a bat to reestablish homeostasis in a number of physiologic systems.

An evaluation of factors affecting duration of treatment with repetitive transcranial magnetic stimulation for depression

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Roni Broder Cohen

2007-12-01

Full Text Available Objective: To investigate the effects of repetitive transcranialmagnetic stimulation in patients with major depression who weresubmitted to this treatment during the period from 2000 to 2006.Methods: A retrospective study with 204 patients who underwenttreatment with repetitive transcranial magnetic stimulation, collectingdata from those who experienced remission (defined as a HDRS scoreequal to or lower than 7. The patients were followed for up to 6 monthsafter treatment. Mean duration of remission for this cohort of patientswas 70.2 (± 58.4 days. Results: The only variable associated withthe duration of remission in the linear regression model was numberof repetitive transcranial magnetic stimulation sessions. Conclusion:Our findings suggest that the greater the number of sessions, the longerthe duration of repetitive transcranial magnetic stimulation effects.Consequently, future research investigating the effects of repetitivetranscranial magnetic stimulation should explore this variable in orderto maximize the therapeutic effects of this new brain stimulationtechnique.

Strong motion duration and earthquake magnitude relationships

International Nuclear Information System (INIS)

Salmon, M.W.; Short, S.A.; Kennedy, R.P.

1992-06-01

Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ''strong motion duration'' has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions

The relationship between duration of psoriasis, vascular inflammation, and cardiovascular events

DEFF Research Database (Denmark)

Egeberg, Alexander; Skov, Lone; Joshi, Aditya A.

2017-01-01

of psoriasis duration [hazard ratio, 1.010; 95% confidence interval, 1.007-1.013]). Limitations These studies utilized observational data. Conclusion We found detrimental effects of psoriasis duration on vascular inflammation and MACE, suggesting that cumulative duration of exposure to low-grade chronic......Background Psoriasis is associated with risk of cardiovascular (CV) disease (CVD) and a major adverse CV event (MACE). Whether psoriasis duration affects risk of vascular inflammation and MACEs has not been well characterized. Objectives We utilized two resources to understand the effect...... of psoriasis duration on vascular disease and CV events: (1) a human imaging study and (2) a population-based study of CVD events. Methods First, patients with psoriasis (N = 190) underwent fludeoxyglucose F 18 positron emission tomography/computed tomography (duration effect reported as a β...

Oxidative stress in patients with type 1 diabetes mellitus: is it affected by a single bout of prolonged exercise?

Directory of Open Access Journals (Sweden)

Maria Pia Francescato

Full Text Available Presently, no clear-cut guidelines are available to suggest the more appropriate physical activity for patients with type 1 diabetes mellitus due to paucity of experimental data obtained under patients' usual life conditions. Accordingly, we explored the oxidative stress levels associated with a prolonged moderate intensity, but fatiguing, exercise performed under usual therapy in patients with type 1 diabetes mellitus and matched healthy controls. Eight patients (4 men, 4 women; 49±11 years; Body Mass Index 25.0±3.2 kg·m(-2; HbA1c 57±10 mmol·mol(-1 and 14 controls (8 men, 6 women; 47±11 years; Body Mass Index 24.3±3.3 kg·m(-2 performed a 3-h walk at 30% of their heart rate reserve. Venous blood samples were obtained before and at the end of the exercise for clinical chemistry analysis and antioxidant capacity. Capillary blood samples were taken at the start and thereafter every 30 min to determine lipid peroxidation. Patients showed higher oxidative stress values as compared to controls (95.9±9.7 vs. 74.1±12.2 mg·L(-1 H2O2; p<0.001. In both groups, oxidative stress remained constant throughout the exercise (p = NS, while oxidative defence increased significantly at the end of exercise (p<0.02 from 1.16±0.13 to 1.19±0.10 mmol·L(-1 Trolox in patients and from 1.09±0.21 to 1.22±0.14 mmol·L(-1 Trolox in controls, without any significant difference between the two groups. Oxidative stress was positively correlated to HbA1c (p<0.005 and negatively related with uric acid (p<0.005. In conclusion, we were the first to evaluate the oxidative stress in patients with type 1 diabetes exercising under their usual life conditions (i.e. usual therapy and diet. Specifically, we found that the oxidative stress was not exacerbated due to a single bout of prolonged moderate intensity aerobic exercise, a condition simulating several outdoor leisure time physical activities. Oxidative defence increased in both patients and controls, suggesting

Turbulent Simulations of Divertor Detachment Based On BOUT + + Framework

Science.gov (United States)

Chen, Bin; Xu, Xueqiao; Xia, Tianyang; Ye, Minyou

2015-11-01

China Fusion Engineering Testing Reactor is under conceptual design, acting as a bridge between ITER and DEMO. The detached divertor operation offers great promise for a reduction of heat flux onto divertor target plates for acceptable erosion. Therefore, a density scan is performed via an increase of D2 gas puffing rates in the range of 0 . 0 ~ 5 . 0 ×1023s-1 by using the B2-Eirene/SOLPS 5.0 code package to study the heat flux control and impurity screening property. As the density increases, it shows a gradually change of the divertor operation status, from low-recycling regime to high-recycling regime and finally to detachment. Significant radiation loss inside the confined plasma in the divertor region during detachment leads to strong parallel density and temperature gradients. Based on the SOLPS simulations, BOUT + + simulations will be presented to investigate the stability and turbulent transport under divertor plasma detachment, particularly the strong parallel gradient driven instabilities and enhanced plasma turbulence to spread heat flux over larger surface areas. The correlation between outer mid-plane and divertor turbulence and the related transport will be analyzed. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-675075.

Associations of sedentary time and patterns of sedentary time accumulation with health-related quality of life in colorectal cancer survivors

Directory of Open Access Journals (Sweden)

Eline H. van Roekel

2016-12-01

Full Text Available Sedentary behavior (sitting/lying at low energy expenditure while awake is emerging as an important risk factor that may compromise the health-related quality of life (HRQoL of colorectal cancer (CRC survivors. We examined associations of sedentary time with HRQoL in CRC survivors, 2–10 years post-diagnosis. In a cross-sectional study, stage I–III CRC survivors (n = 145 diagnosed (2002−2010 at Maastricht University Medical Center+, the Netherlands, wore the thigh-mounted MOX activity monitor 24 h/day for seven consecutive days. HRQoL outcomes were assessed by validated questionnaires (EORTC QLQ-C30, WHODAS II, Checklist Individual Strength, and Hospital Anxiety and Depression Scale. Confounder-adjusted linear regression models were used to estimate associations with HRQoL outcomes of MOX-derived total and prolonged sedentary time (in prolonged sedentary bouts ≥30 min, and usual sedentary bout duration, corrected for waking wear time. On average, participants spent 10.2 h/day sedentary (SD, 1.6, and 4.5 h/day in prolonged sedentary time (2.3. Mean usual sedentary bout duration was 27.3 min (SD, 16.8. Greater total and prolonged sedentary time, and longer usual sedentary bout duration were associated with significantly (P < 0.05 lower physical functioning, and higher disability and fatigue scores. Greater prolonged sedentary time and longer usual sedentary bout duration also showed significant associations with lower global quality of life and role functioning. Associations with distress and social functioning were non-significant. Sedentary time was cross-sectionally associated with poorer HRQoL outcomes in CRC survivors. Prospective studies are needed to investigate whether sedentary time reduction is a potential target for lifestyle interventions aiming to improve the HRQoL of CRC survivors.

Jean Caune, La démocratisation culturelle, une médiation à bout de souffle

OpenAIRE

Clerc, Adeline

2012-01-01

Les travaux de Jean Caune, professeur émérite à l’université Stendhal de Grenoble, portent sur les pratiques esthétiques envisagées comme processus de médiation culturelle. Dans La démocratisation culturelle, une médiation à bout de souffle, il revient sur des notions et expressions trop souvent flottantes telles que « art », « culture », « démocratie culturelle », « action culturelle » et « médiation culturelle », et les met à rude épreuve en réinterrogeant leur signification à travers les é...

Differential effects of acute and regular physical exercise on cognition and affect.

Science.gov (United States)

Hopkins, M E; Davis, F C; Vantieghem, M R; Whalen, P J; Bucci, D J

2012-07-26

The effects of regular exercise versus a single bout of exercise on cognition, anxiety, and mood were systematically examined in healthy, sedentary young adults who were genotyped to determine brain-derived neurotrophic factor (BDNF) allelic status (i.e., Val-Val or Val66Met polymorphism). Participants were evaluated on novel object recognition (NOR) memory and a battery of mental health surveys before and after engaging in either (a) a 4-week exercise program, with exercise on the final test day, (b) a 4-week exercise program, without exercise on the final test day, (c) a single bout of exercise on the final test day, or (d) remaining sedentary between test days. Exercise enhanced object recognition memory and produced a beneficial decrease in perceived stress, but only in participants who exercised for 4 weeks including the final day of testing. In contrast, a single bout of exercise did not affect recognition memory and resulted in increased perceived stress levels. An additional novel finding was that the improvements on the NOR task were observed exclusively in participants who were homozygous for the BDNF Val allele, indicating that altered activity-dependent release of BDNF in Met allele carriers may attenuate the cognitive benefits of exercise. Importantly, exercise-induced changes in cognition were not correlated with changes in mood/anxiety, suggesting that separate neural systems mediate these effects. These data in humans mirror recent data from our group in rodents. Taken together, these current findings provide new insights into the behavioral and neural mechanisms that mediate the effects of physical exercise on memory and mental health in humans. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Differential Effects of Acute and Regular Physical Exercise on Cognition and Affect

Science.gov (United States)

Hopkins, Michael E.; Davis, F. Caroline; VanTieghem, Michelle R.; Whalen, Paul J.; Bucci, David J.

2012-01-01

The effects of regular exercise versus a single bout of exercise on cognition, anxiety, and mood were systematically examined in healthy, sedentary young adults who were genotyped to determine brain-derived neurotrophic factor (BDNF) allelic status (i.e., Val-Val or Val66Met polymorphism). Participants were evaluated on novel object recognition (NOR) memory and a battery of mental health surveys before and after engaging in either a) a four-week exercise program, with exercise on the final test day, b) a four-week exercise program, without exercise on the final test day, c) a single bout of exercise on the final test day, or d) remaining sedentary between test days. Exercise enhanced object recognition memory and produced a beneficial decrease in perceived stress, but only in participants who exercised for four weeks including the final day of testing. In contrast, a single bout of exercise did not affect recognition memory and resulted in increased perceived stress levels. An additional novel finding was that the improvements on the NOR task were observed exclusively in participants who were homozygous for the BDNF Val allele, indicating that altered activity-dependent release of BDNF in Met allele carriers may attenuate the cognitive benefits of exercise. Importantly, exercise-induced changes in cognition were not correlated with changes in mood/anxiety, suggesting that separate neural systems mediate these effects. These data in humans mirror recent data from our group in rodents. Taken together, these current findings provide new insights into the behavioral and neural mechanisms that mediate the effects of physical exercise on memory and mental health in humans. PMID:22554780

Access to Electric Light Is Associated with Shorter Sleep Duration in a Traditionally Hunter-Gatherer Community.

Science.gov (United States)

de la Iglesia, Horacio O; Fernández-Duque, Eduardo; Golombek, Diego A; Lanza, Norberto; Duffy, Jeanne F; Czeisler, Charles A; Valeggia, Claudia R

2015-08-01

Access to electric light might have shifted the ancestral timing and duration of human sleep. To test this hypothesis, we studied two communities of the historically hunter-gatherer indigenous Toba/Qom in the Argentinean Chaco. These communities share the same ethnic and sociocultural background, but one has free access to electricity while the other relies exclusively on natural light. We fitted participants in each community with wrist activity data loggers to assess their sleep-wake cycles during one week in the summer and one week in the winter. During the summer, participants with access to electricity had a tendency to a shorter daily sleep bout (43 ± 21 min) than those living under natural light conditions. This difference was due to a later daily bedtime and sleep onset in the community with electricity, but a similar sleep offset and rise time in both communities. In the winter, participants without access to electricity slept longer (56 ± 17 min) than those with access to electricity, and this was also related to earlier bedtimes and sleep onsets than participants in the community with electricity. In both communities, daily sleep duration was longer during the winter than during the summer. Our field study supports the notion that access to inexpensive sources of artificial light and the ability to create artificially lit environments must have been key factors in reducing sleep in industrialized human societies. © 2015 The Author(s).

Sociality Affects REM Sleep Episode Duration Under Controlled Laboratory Conditions in the Rock Hyrax, Procavia capensis

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Nadine Gravett

2017-11-01

Full Text Available The rock hyrax, Procavia capensis, is a highly social, diurnal mammal. In the current study several physiologically measurable parameters of sleep, as well as the accompanying behavior, were recorded continuously from five rock hyraxes, for 72 h under solitary (experimental animal alone in the recording chamber, and social conditions (experimental animal with 1 or 2 additional, non-implanted animals in the recording chamber. The results revealed no significant differences between solitary and social conditions for total sleep times, number of episodes, episode duration or slow wave activity (SWA for all states examined. The only significant difference observed between social and solitary conditions was the average duration of rapid eye movement (REM sleep episodes. REM sleep episode duration was on average 20 s and 40 s longer under social conditions daily and during the dark period, respectively. It is hypothesized that the increase in REM sleep episode duration under social conditions could possibly be attributed to improved thermoregulation strategies, however considering the limited sample size and design of the current study further investigations are needed to confirm this finding. Whether the conclusions and the observations made in this study can be generalized to all naturally socially sleeping mammals remains an open question.

Influence of acute high-intensity aerobic interval exercise bout on selective attention and short-term memory tasks.

Science.gov (United States)

Alves, Christiano R R; Tessaro, Victor H; Teixeira, Luis A C; Murakava, Karina; Roschel, Hamilton; Gualano, Bruno; Takito, Monica Y

2014-02-01

Acute moderate intensity continuous aerobic exercise can improve specific cognitive functions, such as short-term memory and selective attention. Moreover, high-intensity interval training (HIT) has been recently proposed as a time-efficient alternative to traditional cardiorespiratory exercise. However, considering previous speculations that the exercise intensity affects cognition in a U-shaped fashion, it was hypothesized that a HIT session may impair cognitive performance. Therefore, this study assessed the effects of an acute HIT session on selective attention and short-term memory tasks. 22 healthy middle-aged individuals (M age = 53.7 yr.) engaged in both (1) a HIT session, 10 1 min. cycling bouts at the intensity corresponding to 80% of the reserve heart rate interspersed by 1 min. active pauses cycling at 60% of the reserve heart rate and (2) a control session, consisting of an active condition with low-intensity active stretching exercise. Before and after each experimental session, cognitive performance was assessed by the Victoria Version of the Stroop test (a selective attention test) and the Digit Span test (a short-term memory test). Following the HIT session, the time to complete the Stroop "Color word" test was significantly lower when compared with that of the control session. The performances in the other subtasks of the Stroop test as well as in the Digit Span test were not significantly different. A HIT session can improve cognitive function.

Effect of caffeine on prospective and retrospective duration judgements.

Science.gov (United States)

Gruber, Ronald P; Block, Richard A

2003-07-01

The effects of caffeine on prospective and retrospective duration judgements were evaluated in a double-blind placebo-controlled experiment. After taking either 200 mg caffeine or a placebo, participants touched a 17-sided polygon for 15 s. Then they verbally estimated the number of angles and the duration. Participants in the prospective group were told in advance they would be making a duration estimate, whereas those in the retrospective group were not told. Caffeine reduced duration estimates in the prospective condition but not in the retrospective condition. The effect of caffeine on very long duration comparisons (the past year compared with a year at one-half and one-quarter of one's age) was also evaluated, but none was found. The findings do not support the hypothesis that caffeine affects duration experience by increasing the internal clock rate as a result of its dopamine D(2) agonist properties. The hypothesis that caffeine produces its effect by enhancing memory was considered and rejected. The most parsimonious explanation is that caffeine increased arousal level, which led to a narrowing of the focus of attention to the most salient task. Copyright 2003 John Wiley & Sons, Ltd.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

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F.J. Neves

2012-07-01

Full Text Available To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11 underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96 and control (P = 0.24 experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P 0.05. In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

A single exercise bout augments adenovirus-specific T-cell mobilization and function.

Science.gov (United States)

Kunz, Hawley E; Spielmann, Guillaume; Agha, Nadia H; O'Connor, Daniel P; Bollard, Catherine M; Simpson, Richard J

2018-04-30

Adoptive transfer of virus-specific T-cells (VSTs) effectively treats viral infections following allogeneic hematopoietic stem cell transplantation (alloHSCT), but logistical difficulties have limited widespread availability of VSTs as a post-transplant therapeutic. A single exercise bout mobilizes VSTs specific for latent herpesviruses (i.e. CMV and EBV) to peripheral blood and augments their ex vivo expansion. We investigated whether exercise exerts similar effects on T-cells specific for a NON-latent virus such as adenovirus, which is a major contributor to infection-related morbidity and mortality after alloHSCT. Thirty minutes of cycling exercise increased circulating adenovirus-specific T-cells 2.0-fold and augmented their ex vivo expansion by ~33% compared to rest without altering antigen and MHC-specific autologous target cell killing capabilities. We conclude that exercise is a simple and economical adjuvant to boost the isolation and manufacture of therapeutic VSTs specific to latent and non-latent viruses from healthy donors. Copyright © 2018. Published by Elsevier Inc.

Three dimensional nonlinear simulations of edge localized modes on the EAST tokamak using BOUT++ code

Energy Technology Data Exchange (ETDEWEB)

Liu, Z. X., E-mail: zxliu316@ipp.ac.cn; Xia, T. Y.; Liu, S. C.; Ding, S. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q.; Joseph, I.; Meyer, W. H. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Gao, X.; Xu, G. S.; Shao, L. M.; Li, G. Q.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2014-09-15

Experimental measurements of edge localized modes (ELMs) observed on the EAST experiment are compared to linear and nonlinear theoretical simulations of peeling-ballooning modes using the BOUT++ code. Simulations predict that the dominant toroidal mode number of the ELM instability becomes larger for lower current, which is consistent with the mode structure captured with visible light using an optical CCD camera. The poloidal mode number of the simulated pressure perturbation shows good agreement with the filamentary structure observed by the camera. The nonlinear simulation is also consistent with the experimentally measured energy loss during an ELM crash and with the radial speed of ELM effluxes measured using a gas puffing imaging diagnostic.

Perceived duration of emotional events: evidence for a positivity effect in older adults.

Science.gov (United States)

Nicol, Jeffrey R; Tanner, Jessica; Clarke, Kelly

2013-01-01

BACKGROUND/STUDY CONTEXT: Arousal and negative affect modulate the effect of emotion on the subjective experience of the passage of time. Given that older adults are less aroused by negative emotional stimuli, and report lower levels of negative affect, compared with younger adults, the present study examined whether the effect of emotion on time perception differed in older and younger adults. Participants performed a temporal bisection task for emotional (i.e., angry, sad, happy) and neutral facial expressions presented at varying temporal intervals. Older adults perceived the duration of both positive and threatening events longer than neutral events, whereas younger adults only perceived threatening events longer than neutral events. The results, which are partially consistent with the positivity effect of aging postulated by the socioemotional selectivity theory, are the first to show how the effect of emotion on perceived duration affects older adults, and support previous research indicating that only threatening events prolong perceived duration in younger adults.

Factors affecting incubation patterns and sex roles of black oystercatchers in Alaska

Science.gov (United States)

Spiegel, Caleb S.; Haig, Susan M.; Goldstein, Michael I.; Huso, Manuela M. P.

2012-01-01

Studies examining the effects of human disturbance on avian parental behavior and reproductive success are fundamental to bird conservation. However, many such studies fail to also consider the influence of natural threats, a variable environment, and parental roles. Our work examines interactive relationships of cyclical (time of day, tide, temperature, seasonality) and stochastic (natural/human disturbance) processes with incubation patterns (attendance, bout lengths, recess rates) of the Black Oystercatcher (Haematopus bachmani), a shorebird of conservation concern. We used 24-hour-per-day video monitoring of 13 molecularly-sexed breeding pairs to systematically examine incubation, revealing previously undocumented information that may inform conservation practices for the genus. Seven of 22 video-monitored nests failed, primarily from egg depredation by nocturnally-active mammals. Analyses of 3177 hrs of video footage indicated a near doubling of incubation bout lengths at night, corresponding to the increased risk of nighttime egg predation. Females had higher overall nest attendance (54% vs. 42%) and longer mean incubation bout lengths than males (88 min vs. 73 min). Uninterrupted incubation bouts were over twice as long as bouts interrupted by disturbance. Incubating males departed nests substantially more frequently due to nest-area disturbances than females in one, but not both, years of our study. Our findings suggest that sexes exhibit different, but complimentary, incubation patterns, facilitating efficient egg care in a dynamic environment with several nest threats. We emphasize the importance of considering natural influences when evaluating human threats to shorebird reproductive behavior and success.

Correlation between hematologic profile and transaminase enzymes with hospitalization duration dengue

Science.gov (United States)

Tinambunan, E.; Suryani; Katu, S.; Halim, R.; Mubin, A. H.; Sahyuddin

2018-03-01

Dengue is an infectious disease that can be found from mild to severe andaffected the clinical spectrum of the disease. Various hematologic profiles and transaminase enzymes are thought to reflect the severity of the disease thus affecting the hospitalization duration. For determining the correlation between hematological profile and transaminase enzyme to the hospitalization duration in dengue patients, an observational design study with the cross-sectional approach on dengue subjects was from 2 hospitals in Makassar. Hemoglobin, leukocyte, thrombocyte, AST, ALT, PT, and APTT were examined for hospitalization duration. There were 65 samples (34 men, 31 women) with the length of stay dengue patients. There was no correlation between the elevated of hematocrit value (p = 0.429), thrombocytopenia (p = 1.000), elevated of AST (p = 0.456) and ALT (p = 0.285) on hospitalization duration. In conclusion, low leukocyte values and APTT prolongation correlate with hospitalization duration but did not correlate significantly with hospitalization duration for elevated hematocrit, thrombocytopenia, elevated AST, and ALT.

Duration of plant damage by host larvae affects attraction of two parasitoid species (Microplitis croceipes and Cotesia marginiventris) to cotton: implications for interspecific competition.

Science.gov (United States)

Morawo, Tolulope; Fadamiro, Henry

2014-12-01

Volatile organic compounds (VOCs) released by herbivore-damaged plants can guide parasitoids to their hosts. The quantity and quality of VOC blends emitted by plants may be affected by the duration of plant damage by herbivores, which could have potential ramifications on the recruitment of competing parasitoids. We used two parasitoid species, Microplitis croceipes and Cotesia marginiventris (Hymenoptera: Braconidae), to address the question of whether duration of plant damage affects parasitoid use of plant VOCs for host location. Both wasp species are larval endoparasitoids of Heliothis virescens (Lepidoptera: Noctuidae), an important pest of cotton. Attraction of the two parasitoid species to odors emitted by undamaged (UD), fresh (6 h infestation) damage (FD), and old (24 h infestation) damage (OD) cotton plants infested by H. virescens larvae was investigated using a headspace volatile collection system coupled with four-choice olfactometer bioassay. Both sexes of M. croceipes showed a preference for FD- and OD-plant odors over UD-plants. On the other hand, more C. marginiventris females were attracted to UD- and FD-plants than to OD-plants. GC/MS analyses showed qualitative and quantitative differences in the VOC profiles of UD, FD, and OD-plants, which may explain the observed preferences of the parasitoids. These results suggest a temporal partitioning in the recruitment of M. croceipes and C. marginiventris to H. virescens-damaged cotton, and may have potential implications for interspecific competition between the two parasitoid species.

an acoustic investigation of the duration of vowel nasalization in ga

African Journals Online (AJOL)

Finance

nasalization in Ga. It investigates the duration and also the quality in terms of first and second formant (F1 and F2) values of Ga oral and nasal vowels. It seeks to do a case study of how the duration of vowels affects vowel nasality. Ga is the language of the Ga people in Accra, the seat of the government of Ghana. It is a Kwa ...

Vacancy Duration, Wage Offers, and Job Requirements - Pre-Match Data Evidence

DEFF Research Database (Denmark)

Chen, Long Hwa; Eriksson, Tor Viking

Besides wage offers, credentials like education, work experience and skill requirements are key screening tools for firms in their recruitment of new employees. This paper contributes some new evidence to a relatively tiny literature on firms' recruitment behaviour. In particular, our analysis...... durations. The duration of vacancies due to regular turnover and changing business cycle condition are less affected by skill requirements than that of other vacant jobs....

Risk, treatment duration, and recurrence risk of postpartum affective disorder in women with no prior psychiatric history: A population-based cohort study.

Directory of Open Access Journals (Sweden)

Marie-Louise H Rasmussen

2017-09-01

Full Text Available Some 5%-15% of all women experience postpartum depression (PPD, which for many is their first psychiatric disorder. The purpose of this study was to estimate the incidence of postpartum affective disorder (AD, duration of treatment, and rate of subsequent postpartum AD and other affective episodes in a nationwide cohort of women with no prior psychiatric history.Linking information from several Danish national registers, we constructed a cohort of 457,317 primiparous mothers with first birth (and subsequent births from 1 January 1996 to 31 December 2013 (a total of 789,068 births and no prior psychiatric hospital contacts and/or use of antidepressants. These women were followed from 1 January 1996 to 31 December 2014. Postpartum AD was defined as use of antidepressants and/or hospital contact for PPD within 6 months after childbirth. The main outcome measures were risk of postpartum AD, duration of treatment, and recurrence risk. We observed 4,550 (0.6% postpartum episodes of AD. The analyses of treatment duration showed that 1 year after the initiation of treatment for their first episode, 27.9% of women were still in treatment; after 4 years, 5.4%. The recurrence risk of postpartum AD for women with a PPD hospital contact after first birth was 55.4 per 100 person-years; for women with postpartum antidepressant medication after first birth, it was 35.0 per 100 person-years. The rate of postpartum AD after second birth for women with no history of postpartum AD was 1.2 per 100 person-years. After adjusting for year of birth and mother's age, women with PPD hospital contact after first birth had a 46.4 times higher rate (95% CI 31.5-68.4 and women with postpartum antidepressant medication after their first birth had a 26.9 times higher rate (95% CI 21.9-33.2 of a recurrent postpartum episode after their second birth compared to women with no postpartum AD history. Limitations include the use of registry data to identify cases and limited

Incident Duration Modeling Using Flexible Parametric Hazard-Based Models

Directory of Open Access Journals (Sweden)

Ruimin Li

2014-01-01

Full Text Available Assessing and prioritizing the duration time and effects of traffic incidents on major roads present significant challenges for road network managers. This study examines the effect of numerous factors associated with various types of incidents on their duration and proposes an incident duration prediction model. Several parametric accelerated failure time hazard-based models were examined, including Weibull, log-logistic, log-normal, and generalized gamma, as well as all models with gamma heterogeneity and flexible parametric hazard-based models with freedom ranging from one to ten, by analyzing a traffic incident dataset obtained from the Incident Reporting and Dispatching System in Beijing in 2008. Results show that different factors significantly affect different incident time phases, whose best distributions were diverse. Given the best hazard-based models of each incident time phase, the prediction result can be reasonable for most incidents. The results of this study can aid traffic incident management agencies not only in implementing strategies that would reduce incident duration, and thus reduce congestion, secondary incidents, and the associated human and economic losses, but also in effectively predicting incident duration time.

Duration on unemployment: geographic mobility and selectivity bias.

Science.gov (United States)

Goss, E P; Paul, C; Wilhite, A

1994-01-01

Modeling the factors affecting the duration of unemployment was found to be influenced by the inclusion of migration factors. Traditional models which did not control for migration factors were found to underestimate movers' probability of finding an acceptable job. The empirical test of the theory, based on the analysis of data on US household heads unemployed in 1982 and employed in 1982 and 1983, found that the cumulative probability of reemployment in the traditional model was .422 and in the migration selectivity model was .624 after 30 weeks of searching. In addition, controlling for selectivity eliminated the significance of the relationship between race and job search duration in the model. The relationship between search duration and the county unemployment rate in 1982 became statistically significant, and the relationship between search duration and 1980 population per square mile in the 1982 county of residence became statistically insignificant. The finding that non-Whites have a longer duration of unemployment can better be understood as non-Whites' lower geographic mobility and lack of greater job contacts. The statistical significance of a high unemployment rate in the home labor market reducing the probability of finding employment was more in keeping with expectations. The findings assumed that the duration of employment accurately reflected the length of job search. The sample was redrawn to exclude discouraged workers and the analysis was repeated. The findings were similar to the full sample, with the coefficient for migration variable being negative and statistically significant and the coefficient for alpha remaining positive and statistically significant. Race in the selectivity model remained statistically insignificant. The findings supported the Schwartz model hypothesizing that the expansion of the radius of the search would reduce the duration of unemployment. The exclusion of the migration factor misspecified the equation for

Integration of short bouts of physical activity into organizational routine a systematic review of the literature.

Science.gov (United States)

Barr-Anderson, Daheia J; AuYoung, Mona; Whitt-Glover, Melicia C; Glenn, Beth A; Yancey, Antronette K

2011-01-01

Recommended daily physical activity accumulated in short intervals (e.g., organizational routine as part of the regular "conduct of business." PubMed, MEDLINE, and Google Scholar databases were searched in August 2009 (updated search in February and July 2010) to identify relevant, peer-reviewed journal articles and abstracts on school-, worksite-, and faith-based interventions of short, structurally integrated physical activity breaks. The majority of interventions implemented daily physical activity bouts of 10-15 minutes in length. Schools were the most common settings among the 40 published articles included in this review. The rigor of the studies varied by setting, with more than 75% of worksite versus 25% of school studies utilizing RCT designs. Studies focused on a broad range of outcomes, including academic/work performance indicators, mental health outcomes, and clinical disease risk indicators, in addition to physical activity level. Physical activity was the most commonly assessed outcome in school-based studies, with more than half of studies assessing and observing improvements in physical activity outcomes following the intervention. About a quarter of worksite-based studies assessed physical activity, and the majority found a positive effect of the intervention on physical activity levels. About half of studies also observed improvements in other relevant outcomes such as academic and work performance indicators (e.g., academic achievement, cognitive performance, work productivity); psychosocial factors (e.g., stress, mood); and clinical disease risk indicators (e.g., blood pressure, BMI). The average study duration was more than 1 year, and several reported outcomes at 3-6 years. Interventions integrating physical activity into organizational routine during everyday life have demonstrated modest but consistent benefits, particularly for physical activity, and these are promising avenues of investigation. The proportionately longer-term outcomes

Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.

Science.gov (United States)

Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

2012-07-15

Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

Associations of sedentary behavior, sedentary bouts and breaks in sedentary time with cardiometabolic risk in children with a family history of obesity.

Science.gov (United States)

Saunders, Travis John; Tremblay, Mark Stephen; Mathieu, Marie-Ève; Henderson, Mélanie; O'Loughlin, Jennifer; Tremblay, Angelo; Chaput, Jean-Philippe

2013-01-01

Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children. To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8-11 years with a family history of obesity. Data from 286 boys and 236 girls living in Quebec, Canada, with at least one biological parent with obesity (QUALITY cohort) were collected from 2005-2008, and analyzed in 2013. Sedentary behavior, light and moderate-to-vigorous physical activity were measured over 7 days using accelerometry. Leisure time computer/video game use and TV viewing over the past 7 days were self-reported. Outcomes included waist circumference, body mass index Z-score, fasting insulin, fasting glucose, triglycerides, HDL-cholesterol, C-reactive protein and a continuous cardiometabolic risk score. After adjustment for confounders, breaks in sedentary time and the number of sedentary bouts lasting 1-4 minutes were associated with reduced cardiometabolic risk score and lower BMI Z-score in both sexes (all pfasting glucose in girls, and with BMI Z-score in boys (all pobesity.

Free-living gait characteristics in ageing and Parkinson's disease: impact of environment and ambulatory bout length.

Science.gov (United States)

Del Din, Silvia; Godfrey, Alan; Galna, Brook; Lord, Sue; Rochester, Lynn

2016-05-12

Gait is emerging as a powerful diagnostic and prognostic tool, and as a surrogate marker of disease progression for Parkinson's disease (PD). Accelerometer-based body worn monitors (BWMs) facilitate the measurement of gait in clinical environments. Moreover they have the potential to provide a more accurate reflection of gait in the home during habitual behaviours. Emerging research suggests that measurement of gait using BWMs is feasible but this has not been investigated in depth. The aims of this study were to explore (i) the impact of environment and (ii) ambulatory bout (AB) length on gait characteristics for discriminating between people with PD and age-matched controls. Fourteen clinically relevant gait characteristics organised in five domains (pace, variability, rhythm, asymmetry, postural control) were quantified using laboratory based and free-living data collected over 7 days using a BWM placed on the lower back in 47 PD participants and 50 controls. Free-living data showed that both groups walked with decreased pace and increased variability, rhythm and asymmetry compared to walking in the laboratory setting. Four of the 14 gait characteristics measured in free-living conditions were significantly different between controls and people with PD compared to two measured in the laboratory. Between group differences depended on bout length and were more apparent during longer ABs. ABs ≤ 10s did not discriminate between groups. Medium to long ABs highlighted between-group significant differences for pace, rhythm and asymmetry. Longer ABs should therefore be taken into account when evaluating gait characteristics in free-living conditions. This study provides encouraging results to support the use of a single BWM for free-living gait evaluation in people with PD with potential for research and clinical application.

Partnership duration, concurrency, and HIV in sub-Saharan Africa.

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Sawers, Larry; Isaac, Alan

2017-07-01

A widely accepted explanation for the exceptionally high HIV prevalence in sub-Saharan Africa is the practice of long-term overlapping heterosexual partnering. This article shows that long-duration concurrent partnering can be protective against HIV transmission rather than promoting it. Monogamous partnering prevents sexual transmission to anyone outside the partnership and, in an initially concordant-seronegative partnership, prevents sexual acquisition of HIV by either partner. Those protections against transmission and acquisition last as long as the partnership persists without new outside partnerships. Correspondingly, these two protective effects characterise polygynous partnerships, whether or not the polygyny is formal or informal, until a partner initiates a new partnership. Stable and exclusive unions of any size protect against HIV transmission, and more durable unions provide a longer protective effect. Survey research provides little information on partnership duration in sub-Saharan Africa and sheds no light on the interaction of duration, concurrency, and HIV. This article shows how assumptions about partnership duration in individual-based sexual-network models affect the contours of simulated HIV epidemics. Longer mean partnership duration slows the pace at which simulated epidemics grow. With plausible assumptions about partnership duration and at levels of concurrency found in the region, simulated HIV epidemics grow slowly or not at all. Those results are consistent with the hypothesis that long-duration partnering is protective against HIV and inconsistent with the hypothesis that long-term concurrency drives the HIV epidemics in sub-Saharan Africa.

Influence of the laser pulse duration on laser-produced plasma properties

International Nuclear Information System (INIS)

Drogoff, B Le; Margot, J; Vidal, F; Laville, S; Chaker, M; Sabsabi, M; Johnston, T W; Barthelemy, O

2004-01-01

In the framework of laser-induced plasma spectroscopy (LIPS) applications, time-resolved characteristics of laser-produced aluminium plasmas in air at atmospheric pressure are investigated for laser pulse durations ranging from 100 fs to 270 ps. Measurements show that for delays after the laser pulse longer than ∼100 ns, the plasma temperature increases slightly with the laser pulse duration, while the electron density is independent of it. In addition, as the pulse duration increases, the plasma radiation emission lasts longer and the spectral lines arise later from the continuum emission. The time dependence of the continuum emission appears to be similar whatever the duration of the laser pulse is, while the temporal evolution of the line emission seems to be affected mainly by the plasma temperature. Finally, as far as spectrochemical applications (such as LIPS) of laser-produced plasmas are concerned, this study highlights the importance of the choice of appropriate temporal gating parameters for each laser pulse duration

Lack of CRH Affects the Behavior but Does Not Affect the Formation of Short-Term Memory.

Science.gov (United States)

Varejkova, Eva; Plananska, Eva; Myslivecek, Jaromir

2018-01-01

Corticotropin-releasing hormone (CRH) is involved in modification of synaptic transmission and affects spatial discrimination learning, i.e., affects the formation of memory in long-term aspect. Therefore, we have focused on CRH effect on short-term memory. We have used stress task avoidance (maze containing three zones: entrance, aversive, and neutral) and compared the behavior and short-term memory in wild-type mice and mice lacking CRH (CRH KO) experiencing one 120-min session of restraint stress. As control, non-stressed animals were used. As expected, the animals that experienced the stress situation tend to spend less time in the zone in which the restraint chamber was present. The animals spent more time in the neutral zone. There were significant differences in number of freezing bouts in the aversive and entrance zones in CRH KO animals. CRH KO control animals entered the neutral zone much more faster than WT control and spent more time immobile in the neutral zone than WT control. These data give evidence that lacking of CRH itself improves the ability of mice to escape away from potentially dangerous area (i.e., those in which the scent of stressed animal is present).

Written Spelling to Dictation: Sound-To-Spelling Regularity Affects Both Writing Latencies and Durations

Science.gov (United States)

Delattre, Marie; Bonin, Patrick; Barry, Christopher

2006-01-01

The authors examined the effect of sound-to-spelling regularity on written spelling latencies and writing durations in a dictation task in which participants had to write each target word 3 times in succession. The authors found that irregular words (i.e., those containing low-probability phoneme-to-grapheme mappings) were slower both to…

Similar mitochondrial signaling responses to a single bout of continuous or small-sided-games-based exercise in sedentary men.

Science.gov (United States)

Mendham, Amy E; Duffield, Rob; Coutts, Aaron J; Marino, Frank E; Boyko, Andriy; McAinch, Andrew J; Bishop, David John

2016-12-01

This study assessed the mitochondrial related signaling responses to a single bout of noncontact, modified football (touch rugby), played as small-sided games (SSG), or cycling (CYC) exercise in sedentary, obese, middle-aged men. In a randomized, crossover design, nine middle-aged, sedentary, obese men completed two, 40-min exercise conditions (CYC and SSG) separated by a 21-day recovery period. Heart rate (HR) and ratings of perceived exertion (RPE) were collected during each bout. Needle biopsies from the vastus lateralis muscle were collected at rest and 30 and 240 min postexercise for analysis of protein content and phosphorylation (PGC-1α, SIRT1, p53, p53 Ser15 , AMPK, AMPK Thr172 , CAMKII, CAMKII Thr286 , p38MAPK, and p38MAPK Thr180/Tyr182 ) and mRNA expression (PGC-1α, p53, NRF1, NRF2, Tfam, and cytochrome c). A main effect of time effect for both conditions was evident for HR, RPE, and blood lactate (P 0.05). Both conditions increased PGC1-α protein and mRNA expression at 240 min (P 0.05). CYC increased p53 protein content at 240 min to a greater extent than SSG (P benefit for stimulating mitochondrial biogenesis. Differences between conditions regarding fluctuation in exercise intensity and type of muscle contraction may explain the increase of p53 and AMPK within CYC and not SSG (noncontact, modified football). Copyright © 2016 the American Physiological Society.

Modeling drivers' passing duration and distance in a virtual environment

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Haneen Farah

2013-07-01

The main contribution of this paper is in the empirical models developed for passing duration and distance which highlights the factors that affect drivers' passing behavior and can be used to enhance the passing models in simulation programs.

Does temperature and oxygen affect duration of intramarsupial development and juvenile growth in the terrestrial isopod Porcellio scaber (Crustacea, Malacostraca?

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Terézia Horváthová

2015-07-01

Full Text Available According to the temperature-size rule (TSR, ectotherms developing under cold conditions experience slower growth as juveniles but reach a larger size at maturity. Whether temperature alone causes this phenomenon is unknown, but oxygen limitation can play a role in the temperature-size relationship. Oxygen may become limited under warm conditions when the resulting higher metabolism creates a greater demand for oxygen, especially in larger individuals. We examined the independent effects of oxygen concentration (10% and 22% O2 and temperature (15 °C and 22 °C on duration of ontogenic development, which takes place within the maternal brood pouch (marsupium, and juvenile growth in the terrestrial isopod common rough woodlouse (Porcellio scaber. Individuals inside the marsupium undergo the change from the aqueous to the gaseous environment. Under hypoxia, woodlice hatched from the marsupium sooner, but their subsequent growth was not affected by the level of oxygen. Marsupial development and juvenile growth were almost three times slower at low temperature, and marsupial development was longer in larger females but only in the cold treatment. These results show that temperature and oxygen are important ecological factors affecting developmental time and that the strength of the effect likely depends on the availability of oxygen in the environment.

The influence of reproductive condition and concurrent environmental factors on torpor and foraging patterns in female big brown bats (Eptesicus fuscus).

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Rintoul, Jody L P; Brigham, R Mark

2014-08-01

Unlike many other mammals, bats in temperate regions employ short bouts of torpor throughout the reproductive period to maintain a positive energy balance. In addition to decreasing energy expenditure during the day, they typically alter foraging patterns as well. It is well known that various environmental conditions influence both torpor and foraging patterns, but studies of these factors often have focussed on one element in isolation thus it is not known how the two behaviours are collectively influencing temperate bats. The objective of our study was to assess how reproductive condition and environmental factors concurrently affect energy balance in female big brown bats (Eptesicus fuscus). We equipped pregnant and lactating bats in southwest Saskatchewan, Canada with temperature-sensitive radio-transmitters. While transmitters were active, skin temperature data were collected and foraging patterns were determined using triangulation. Of the various environmental and physiological parameters used to model torpor characteristics, roost type was the most important factor. Bats roosting in trees used deeper and longer torpor bouts than those roosting in buildings. Lactating bats had a tendency to forage for longer durations than pregnant bats, and often made more foraging trips. When taken together, we found that foraging duration and torpor duration were not directly related during pregnancy, but exhibited an inverse relationship during lactation. This provides support for the hypothesis that there are physiological trade-offs for reproductive bats and suggests that how bats compensate is not entirely predictable based on current environmental conditions.

Pulse duration discriminator

International Nuclear Information System (INIS)

Kosakovskij, L.F.

1980-01-01

Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

Substance use and duration of untreated psychosis in KwaZulu ...

African Journals Online (AJOL)

Background: Substance use and psychiatric disorders cause significant burden of disease in low- and middle-income countries. Co-morbid psychopathology and longer duration of untreated psychosis (DUP) can negatively affect treatment outcomes. Objectives: The study assessed substance use amongst adults with ...

The Effect of Different Recovery Duration on Repeated Anaerobic Performance in Elite Cyclists

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Harbili Sultan

2015-12-01

Full Text Available This study investigated the effect of recovery duration on repeated anaerobic performance in elite cyclists. The study followed a cross-over design protocol. Twelve elite male cyclists were randomly assigned to three groups (with recovery duration of 1, 2 and 3 min, respectively. All the subjects performed 4 repeated Wingate tests (4 × 30 s WT at 48 h intervals for three different recovery periods. No significant interaction was observed between the effects of recovery duration and repetition (p>0.05, whereas there was a significant main effect of repetition on peak power, mean power, and a fatigue index (p0.05. In contrast, mean power decreased significantly in repeated WTs with 1, 2 and 3 min recovery duration (p0.05. In a 4 × 30 s WT, peak power decreased in cycles with 1 and 2 min recovery duration, but remained unchanged with 3 min recovery duration, whereas mean power decreased in all recovery duration procedures. The WT with 1 min recovery duration caused greater fatigue. Although recovery duration affected both peak power and mean power, the effect on peak power was greater.

The effect of wheelchair propulsion style on changes in time spent in extreme wrist orientations after a bout of fatiguing propulsion.

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Zukowski, Lisa A; Hass, Chris J; Shechtman, Orit; Christou, Evangelos A; Tillman, Mark D

2017-10-01

This study compared how wheelchair propulsion styles affect changes in percentage of time spent in extreme wrist orientations, which have been associated with median nerve injury, after a fatiguing bout of propulsion. Twenty novice, non-disabled adult males learned arcing (ARC) and semicircular (SEMI) propulsion styles and utilised each to perform a wheelchair fatigue protocol. ARC and SEMI did not significantly differ in terms of changes after the fatigue protocol in percentage of time spent in extreme flexion/extension or radial/ulnar deviation at the push phase beginning or end. A pattern was observed, although not significant, of greater increases in percentage of time spent in extreme wrist extension and ulnar deviation during the push phase beginning and ulnar deviation during the push phase end while utilising SEMI relative to ARC. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles. Practitioner Summary: How wheelchair propulsion styles change with fatigue in terms of extreme wrist orientations was examined. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles and point towards the need for future research on individual differences utilising propulsion styles.

A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy.

Science.gov (United States)

Spielmann, Guillaume; Bollard, Catherine M; Kunz, Hawley; Hanley, Patrick J; Simpson, Richard J

2016-05-16

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy.

Do sediment type and test durations affect results of laboratory-based, accelerated testing studies of permeable pavement clogging?

Science.gov (United States)

Nichols, Peter W B; White, Richard; Lucke, Terry

2015-04-01

Previous studies have attempted to quantify the clogging processes of Permeable Interlocking Concrete Pavers (PICPs) using accelerated testing methods. However, the results have been variable. This study investigated the effects that three different sediment types (natural and silica), and different simulated rainfall intensities, and testing durations had on the observed clogging processes (and measured surface infiltration rates) of laboratory-based, accelerated PICP testing studies. Results showed that accelerated simulated laboratory testing results are highly dependent on the type, and size of sediment used in the experiments. For example, when using real stormwater sediment up to 1.18 mm in size, the results showed that neither testing duration, nor stormwater application rate had any significant effect on PICP clogging. However, the study clearly showed that shorter testing durations generally increased clogging and reduced the surface infiltration rates of the models when artificial silica sediment was used. Longer testing durations also generally increased clogging of the models when using fine sediment (<300 μm). Results from this study will help researchers and designers better anticipate when and why PICPs are susceptible to clogging, reduce maintenance and extend the useful life of these increasingly common stormwater best management practices. Copyright © 2015 Elsevier B.V. All rights reserved.

Associations of Sedentary Behavior, Sedentary Bouts and Breaks in Sedentary Time with Cardiometabolic Risk in Children with a Family History of Obesity

OpenAIRE

Saunders, Travis John; Tremblay, Mark Stephen; Mathieu, Marie-?ve; Henderson, M?lanie; O?Loughlin, Jennifer; Tremblay, Angelo; Chaput, Jean-Philippe

2013-01-01

Background Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children. Purpose To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8?11 years with a family history of obesity. Methods Data from 286 boys and 236 girls living in Quebec, Cana...

Using activity triggered e-diaries to reveal the associations between physical activity and affective states in older adult's daily living.

Science.gov (United States)

Kanning, Martina; Ebner-Priemer, Ulrich; Schlicht, Wolfgang

2015-09-17

Evidence suggests that older adults show positive affects after participating in exercise bouts. However, it is less clear, if and how physical activities in daily living enhance affective states, too. This is dissatisfying, as most of older adults' physical activities are part of their daily living. To answer these questions we used activity-triggered e-diaries to investigate the within-subject effects of physical activity on three dimensions of affective states (valence, energetic arousal, calmness) during everyday life. Older adults (N = 74) between 50 and 70 years took part in the study during three consecutive days. Physical activity in daily living was objectively assessed using accelerometers. Affects were measured 10 min after a study participant surpassed a predefined threshold for activity or inactivity. The participants were prompted by an acoustic signal to assess their momentary affective states on an e-diary. Data were analyzed with hierarchical multilevel analyses. Whenever older individuals were more physically active, they felt more energized (energetic arousal) and agitated (calmness). However, they did not feel better (valence). Interestingly, body mass index (BMI) and valence were associated in a significant cross-level interaction. BMI acts as a moderating variable in the way that lower BMI scores were associated with higher levels of valence scores after being physically active. The innovative ambulatory assessment used here affords an interesting insight to the affective effects of daily activity of older adults. These effects are no simple and no linear ones, i.e. physical activity is not associated with positive affects per se as shown several times in experimental studies with single activity bouts. Rather there is a differentiating association seen as an enhanced feeling of energy and agitation, which is not accompanied by a better feeling. Socio-emotional selectivity theory may support the finding that older individuals are

The duration perception of loading applications in smartphone: Effects of different loading types.

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Zhao, Wenguo; Ge, Yan; Qu, Weina; Zhang, Kan; Sun, Xianghong

2017-11-01

The loading time of a smartphone application is an important issue, which affects the satisfaction of phone users. This study evaluated the effects of black loading screen (BLS) and animation loading screen (ALS) during application loading on users' duration perception and satisfaction. A total of 43 volunteers were enrolled. They were asked to complete several tasks by clicking the icons of each application, such as camera or message. The duration of loading time for each application was manipulated. The participants were asked to estimate the duration, evaluate the loading speed and their satisfaction. The results showed that the estimated duration increased and the satisfaction for loading period declined along with the loading time increased. Compared with the BLS, the ALS prolonged the estimated duration, and lowered the evaluation of speed and satisfaction. We also discussed the tendency and key inflection points of the curves involving the estimated duration, speed evaluation and satisfaction with the loading time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rate and duration of seed filling and yield of soybean affected by water and radiation deficits

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Kazem GHASSEMI-GOLEZANI

2015-11-01

Full Text Available Seed filling and yield of soybean under water and radiation deficits were investigated during 2011 and 2012. Treatments were irrigations (I1, I2, I3 and I4 for irrigation after 60, 90, 120 and 150 mm evaporation from class A pan, respectively in main plots and light interceptions (L1: 100 %, L2: 65 % and L3: 25 % sunlight in sub-plots. Seeds per plant under I1 and I2 decreased, but under I3 and I4 increasedas a result of radiation deficit. Maximum seed weight and seed filling duration of plants under 25 % light interception (L3 were higher than those under full sunlight (L1 and 65 % light interception (L2. In contrast, plants under full sunlight had the highest seed filling rate, particularly under water stress. Seed filling duration under severe light deficit (L3 was about 9 days longer than that under full sunlight (L1, leading to 15.8 % enhancement in maximum seed weight. Decreasing seed yield of soybean under well watering and mild water stress and improving it under moderate and severe water deficit due to low solar radiation are directly related with changes in seed filling duration and consequently in seed weight and number of seeds per plant under these conditions.

Situational motivation and perceived intensity: their interaction in predicting changes in positive affect from physical activity.

Science.gov (United States)

Guérin, Eva; Fortier, Michelle S

2012-01-01

There is evidence that affective experiences surrounding physical activity can contribute to the proper self-regulation of an active lifestyle. Motivation toward physical activity, as portrayed by self-determination theory, has been linked to positive affect, as has the intensity of physical activity, especially of a preferred nature. The purpose of this experimental study was to examine the interaction between situational motivation and intensity [i.e., ratings of perceived exertion (RPE)] in predicting changes in positive affect following an acute bout of preferred physical activity, namely, running. Fourty-one female runners engaged in a 30-minute self-paced treadmill run in a laboratory context. Situational motivation for running, pre- and post-running positive affect, and RPE were assessed via validated self-report questionnaires. Hierarchical regression analyses revealed a significant interaction effect between RPE and introjection (P positive affect was considerable, with higher RPE ratings being associated with greater increases in positive affect. The implications of the findings in light of SDT principles as well as the potential contingencies between the regulations and RPE in predicting positive affect among women are discussed.

The relationship between duration of psoriasis, vascular inflammation, and cardiovascular events.

Science.gov (United States)

Egeberg, Alexander; Skov, Lone; Joshi, Aditya A; Mallbris, Lotus; Gislason, Gunnar H; Wu, Jashin J; Rodante, Justin; Lerman, Joseph B; Ahlman, Mark A; Gelfand, Joel M; Mehta, Nehal N

2017-10-01

Psoriasis is associated with risk of cardiovascular (CV) disease (CVD) and a major adverse CV event (MACE). Whether psoriasis duration affects risk of vascular inflammation and MACEs has not been well characterized. We utilized two resources to understand the effect of psoriasis duration on vascular disease and CV events: (1) a human imaging study and (2) a population-based study of CVD events. First, patients with psoriasis (N = 190) underwent fludeoxyglucose F 18 positron emission tomography/computed tomography (duration effect reported as a β-coefficient). Second, MACE risk was examined by using nationwide registries (adjusted hazard ratios in patients with psoriasis (n = 87,161) versus the general population (n = 4,234,793). In the human imaging study, patients were young, of low CV risk by traditional risk scores, and had a high prevalence of cardiometabolic diseases. Vascular inflammation by fludeoxyglucose F 18 positron emission tomography/computed tomography was significantly associated with disease duration (β = 0.171, P = .002). In the population-based study, psoriasis duration had strong relationship with MACE risk (1.0% per additional year of psoriasis duration [hazard ratio, 1.010; 95% confidence interval, 1.007-1.013]). These studies utilized observational data. We found detrimental effects of psoriasis duration on vascular inflammation and MACE, suggesting that cumulative duration of exposure to low-grade chronic inflammation may accelerate vascular disease development and MACEs. Providers should consider inquiring about duration of disease to counsel for heightened CVD risk in psoriasis. Copyright © 2017 American Academy of Dermatology, Inc. All rights reserved.

In-Hospital Haloperidol Use and Perioperative Changes in QTc-Duration.

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Blom, M T; Jansen, S; de Jonghe, A; van Munster, B C; de Boer, A; de Rooij, S E; Tan, H L; van der Velde, N

2015-05-01

Haloperidol may prolong ECG QTc-duration but is often prescribed perioperatively to hip-fracture patients. We aimed to determine (1) how QTc-duration changes perioperatively, (2) whether low-dose haloperidol-use influences these changes, and (3) which clinical variables are associated with potentially dangerous perioperative QTc-prolongation (PD-QTc; increase >50 ms or to >500 ms). Prospective cohort study. Tertiary university teaching-hospital. Patients enrolled in a randomized controlled clinical trial of melatonin versus placebo on occurrence of delirium in hip-fracture patients. Data from ECGs made before and after hip surgery (1-3 days and/or 4-6 days post-surgery) were analyzed. QTc-duration was measured by hand, blinded for haloperidol and pre/post-surgery status. Clinical variables were measured at baseline. Mixed model analysis was used to estimate changes in QTc-duration. Risk-factors for PD-QTc were estimated by logistic regression analysis. We included 89 patients (mean age 84 years, 24% male); 39 were treated with haloperidol. Patients with normal pre-surgery QTc-duration (male ≤430 ms, female ≤450 ms) had a significant increase (mean 12 ms, SD 28) in QTc-duration. A significant decrease (mean 19 ms, SD 34) occurred in patients with prolonged pre-surgery QTc-duration (male >450ms, female >470 ms). Haloperidol-use did not influence the perioperative course of the QTc-interval (p=0.351). PD-QTc (n=8) was not associated with any of the measured risk-factors. QTc-duration changed differentially, increasing in patients with normal, but decreasing in patients with abnormal baseline QTc-duration. PD-QTc was not associated with haloperidol-use or other risk-factors. Low-dose oral haloperidol did not affect perioperative QTc-interval.

Association of sleep duration with arterial blood pressure profile of Gujarati Indian adolescents

Directory of Open Access Journals (Sweden)

Shaikh Wasim

2010-01-01

Full Text Available Background and Aim: Recently, National Health and Nutritional Examination Survey-1 data analysis found short sleep duration as a risk factor for hypertension in the U.S. population. However, since ethnic differences exist in the aetiopathogenesis of diseases, the current study was undertaken to study the effect of sleep duration on the blood pressure profile of Gujarati Indian adolescents. Materials and Methods: A cross-sectional study was conducted on 489 Gujarati Indian adolescents of age group 16-19 years studying in school and colleges in the local population. The participants were assessed for their sleep duration, physical activity status, body composition, blood pressure profile and cardiovascular reactivity. The sleep duration was reported by the subjects as the number of hours they slept on most of the nights in a week over the last one year. The observations of the study were then analyzed after grouping them into: 1 Adequate Sleep Duration at Night, ASDN (≥ 7 hrs and 2 Inadequate Sleep Duration at Night, ISDN (< 7 hrs groups. Student′s unpaired t-test was used to study if any significant difference (P< 0.05 existed between the groups. Results: No significant difference was found in Systolic blood pressure, Diastolic blood pressure, Pulse pressure and Mean arterial pressure between the ASDN group and the ISDN group. Physical activity status also did not differ between the two groups. However, adolescents of ISDN group showed a significantly higher level of adiposity and cardiovascular reactivity as compared to adolescents of ASDN group. Conclusion: Although short sleep duration is associated with a higher level of adiposity and cardiovascular reactivity in Gujarati Indian adolescents, it does not affect the resting blood pressure profile of these adolescents. However, longitudinal studies would be required to observe if the changes in adiposity and cardiovascular reactivity affect these adolescents in later life.

Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula

Czech Academy of Sciences Publication Activity Database

Konvalinková, T.; Püschel, David; Janoušková, Martina; Gryndler, M.; Jansa, J.

2015-01-01

Roč. 6, FEB 13 (2015), s. 1-11 ISSN 1664-462X Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal symbiosis * light intensity * shading duration Subject RIV: EE - Microbiology, Virology Impact factor: 4.495, year: 2015

Changes in ambient temperature and oxygenation during the proestrus do not affect duration, regularity and repeatability of the estrus cycle in female rats.

Directory of Open Access Journals (Sweden)

Grazyna Wójcik

2009-12-01

Full Text Available There are a lot of factors affecting the release of hormones from the anterior part of pituitary gland and their interactions with other parts of the endocrine, nervous and immune systems. The special significance of the proestrus phase of the estrous cycle of the rat, during which LH and FSH levels increase, followed by ovulation is known. The short length of the estrous cycle and the well recognized sequence of vaginal lavage cytology make it useful for investigating the influence of a stressful environment on the reproductive function. Short duration and mild changes in environmental conditions is considered as a factor analogous to psychological stress. The study was undertaken to determine the effects of a short duration change in the ambient temperature and oxygenation (30 minutes on the proestrus phase of reproductive cycle and on the repeatability and regularity of phases of the reproductive cycle of Wistar strain rats. The animals were kept under standard conditions and had food and water available ad libitum. The climatic chamber with automatically adjustable and monitored internal parameters (temperature, oxygenation, humidity was used to develop stress conditions. An estimation of the vaginal lavage using the microscope was done to determine the estrous cycle. The animals were divided into 6 groups. On the day of experiment: the control group (CG stayed in the climatic chamber for 30 minutes (ambient temperature 21 degrees C, normoxia - 21% O(2, the five test groups (TG - I - V remained in the climatic chamber for 30 minutes, in the established environmental conditions (I - 21 degrees C, 10% O(2; II - 10 degrees C, 21% O(2; III - 10 degrees C, 10% O(2; IV - 35 degrees C, 21% O(2; V - 35 degrees C, 10% O(2. During the following days after the experiment, a microscopic estimation of vaginal lavage was collected over again. There were no changes of duration and sequence of the present estrous cycle and repeatability of the next cycles

Impact of a single bout of high-intensity interval exercise and short-term interval training on interleukin-6, FNDC5, and METRNL mRNA expression in human skeletal muscle

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Malcolm Eaton

2018-04-01

Full Text Available Background: Exercise promotes numerous phenotypic adaptations in skeletal muscle that contribute to improved function and metabolic capacity. An emerging body of evidence suggests that skeletal muscle also releases a myriad of factors during exercise, termed “myokines”. The purpose of this study was to examine the effects of high-intensity interval training (HIIT on the acute regulation of the mRNA expression of several myokines, including the prototypical myokine interleukin-6 (IL-6, and recently identified myokines fibronectin type III domain-containing protein 5 (FNDC5 (irisin and meteorin-like protein (METRNL. Methods: Both before and after a 20-day period of twice-daily high-volume HIIT, 9 healthy males (20.5 ± 1.5 years performed a standardized bout of high-intensity interval exercise (HIIE; 5 × 4 min at ~80% pretraining peak power output with skeletal muscle biopsy samples (vastus lateralis obtained at rest, immediately following exercise, and at 3 h recovery. Results: Before training, a single bout of HIIE increased IL-6 (p < 0.05 and METRNL (p < 0.05 mRNA expression measured at 3 h recovery when compared to rest. Following 20 days of HIIT, IL-6 and FNDC5 mRNA were increased at 3 h recovery from the standardized HIIE bout when compared to rest (both p < 0.05. Resting METRNL and FNDC5 mRNA expression were higher following training (p < 0.05, and there was an overall increase in FNDC5 mRNA post-training (main effect of training, p < 0.05. Conclusion: In human skeletal muscle (1 an acute bout of HIIE can induce upregulation of skeletal muscle IL-6 mRNA both before and after a period of intensified HIIT; (2 Resting and overall FNDC5 mRNA expression is increased by 20 days of HIIT; and (3 METRNL mRNA expression is responsive to both acute HIIE and short-term intense HIIT. Future studies are needed to confirm these findings at the protein and secretion level in humans. Keywords: Brown adipose tissue

Interrupting prolonged sitting with brief bouts of light walking or simple resistance activities reduces resting blood pressure and plasma noradrenaline in type 2 diabetes.

Science.gov (United States)

Dempsey, Paddy C; Sacre, Julian W; Larsen, Robyn N; Straznicky, Nora E; Sethi, Parneet; Cohen, Neale D; Cerin, Ester; Lambert, Gavin W; Owen, Neville; Kingwell, Bronwyn A; Dunstan, David W

2016-12-01

Prolonged sitting is increasingly recognized as a ubiquitous cardiometabolic risk factor, possibly distinct from lack of physical exercise. We examined whether interrupting prolonged sitting with brief bouts of light-intensity activity reduced blood pressure (BP) and plasma noradrenaline in type 2 diabetes (T2D). In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men; mean ± SD; 62 ± 6 years) consumed standardized meals during 3 × 8 h conditions: uninterrupted sitting (SIT); sitting + half-hourly bouts of walking (3.2 km/h for 3-min) (light-intensity walking); and sitting + half-hourly bouts of simple resistance activities for 3 min (SRAs), each separated by 6-14 days washout. Resting seated BP was measured hourly (mean of three recordings, ≥20-min postactivity). Plasma noradrenaline was measured at 30-min intervals for the first hour after meals and hourly thereafter. Compared with SIT, mean resting SBP and DBP were significantly reduced (P light-intensity walking (mean ± SEM; -14 ± 1/-8 ± 1 mmHg) and SRA (-16 ± 1/-10 ± 1 mmHg), with a more pronounced effect for SRA (P light-intensity walking). Similarly, mean plasma noradrenaline was significantly reduced for both light-intensity walking (-0.3 ± 0.1 nmol/l) and SRA (-0.6 ± 0.1 nmol/l) versus SIT, with SRA lower than light-intensity walking (P light-intensity walking (-3 ± 1 bpm; P light-intensity walking or SRA reduces resting BP and plasma noradrenaline in adults with T2D, with SRA being more effective. Given the ubiquity of sedentary behaviors and poor adherence to structured exercise, this approach may have important implications for BP management in patients with T2D.

Timing and Duration of Drug Exposure Affects Outcomes of a Drug-Nutrient Interaction During Ontogeny

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Jane Alcorn

2010-10-01

Full Text Available Significant drug-nutrient interactions are possible when drugs and nutrients share the same absorption and disposition mechanisms. During postnatal development, the outcomes of drug-nutrient interactions may change with postnatal age since these processes undergo ontogenesis through the postnatal period. Our study investigated the dependence of a significant drug-nutrient interaction (cefepime-carnitine on the timing and duration of drug exposure relative to postnatal age. Rat pups were administered cefepime (5 mg/kg twice daily subcutaneously according to different dosing schedules (postnatal day 1-4, 1-8, 8-11, 8-20, or 1-20. Cefepime significantly reduced serum and heart L-carnitine levels in postnatal day 1-4, 1-8 and 8-11 groups and caused severe degenerative changes in ventricular myocardium in these groups. Cefepime also altered the ontogeny of several key L-carnitine homeostasis pathways. The qualitative and quantitative changes in levels of hepatic γ-butyrobetaine hydroxylase mRNA and activity, hepatic trimethyllysine hydroxlase mRNA, intestinal organic cation/carnitine transporter (Octn mRNA, and renal Octn2 mRNA depended on when during postnatal development the cefepime exposure occurred and duration of exposure. Despite lower levels of heart L-carnitine in earlier postnatal groups, levels of carnitine palmitoyltransferase mRNA and activity, heart Octn2 mRNA and ATP levels in all treatment groups remained unchanged with cefepime exposure. However, changes in other high energy phosphate substrates were noted and reductions in the phosphocreatine/ATP ratio were found in rat pups with normal serum L-carnitine levels. In summary, our data suggest a significant drug-nutrient transport interaction in developing neonates, the nature of which depends on the timing and duration of exposure relative to postnatal age.

Discounted Duration Calculus

DEFF Research Database (Denmark)

Ody, Heinrich; Fränzle, Martin; Hansen, Michael Reichhardt

2016-01-01

To formally reason about the temporal quality of systems discounting was introduced to CTL and LTL. However, these logic are discrete and they cannot express duration properties. In this work we introduce discounting for a variant of Duration Calculus. We prove decidability of model checking...... for a useful fragment of discounted Duration Calculus formulas on timed automata under mild assumptions. Further, we provide an extensive example to show the usefulness of the fragment....

The genetic basis of novel water utilisation and drinking behaviour traits and their relationship with biological performance in turkeys.

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Rusakovica, Julija; Kremer, Valentin D; Plötz, Thomas; Rohlf, Paige; Kyriazakis, Ilias

2017-09-29

There is increasing interest in the definition, measurement and use of traits associated with water use and drinking behaviour, mainly because water is a finite resource and its intake is an important part of animal health and well-being. Analysis of such traits has received little attention, due in part to the lack of appropriate technology to measure drinking behaviour. We exploited novel equipment to collect water intake data in two lines of turkey (A: 27,415 and B: 12,956 birds). The equipment allowed continuous recording of individual visits to the water station in a group environment. Our aim was to identify drinking behaviour traits of biological relevance, to estimate their genetic parameters and their genetic relationships with performance traits, and to identify drinking behaviour strategies among individuals. Visits to the drinkers were clustered into bouts, i.e. time intervals spent in drinking-related activity. Based on this, biologically relevant traits were defined: (1) number of visits per bout, (2) water intake per bout, (3) drinking time per bout, (4) drinking rate, (5) daily bout frequency, (6) daily bout duration, (7) daily drinking time and (8) daily water intake. Heritability estimates for most drinking behaviour traits were moderate to high and the most highly heritable traits were drinking rate (0.49 and 0.50) and daily drinking time (0.35 and 0.46 in lines A and B, respectively). Genetic correlations between drinking behaviour and performance traits were low except for moderate correlations between daily water intake and weight gain (0.46 and 0.47 in lines A and B, respectively). High estimates of breeding values for weight gain were found across the whole range of estimated breeding values for daily water intake, daily drinking time and water intake per bout. We show for the first time that drinking behaviour traits are moderately to highly heritable. Low genetic and phenotypic correlations with performance traits suggest that current

Different ankle muscle coordination patterns and co-activation during quiet stance between young adults and seniors do not change after a bout of high intensity training.

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Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2015-03-04

Available evidence suggests that young adults and seniors use different strategies to adjust for increasing body sway during quiet standing. Altered antagonist muscle co-activation and different ankle muscle coordination patterns may account for this finding. Consequently, we aimed at addressing whether aging leads to changes in neuromuscular coordination patterns as well as co-activation during quiet stance. We additionally investigated whether a bout of high intensity interval training additionally alters these patterns. Twenty healthy seniors (age: 70 ± 4 y) and twenty young adults (age: 27 ± 3 y) were enrolled in the present study. In between the testing procedures, four consecutive high-intensity intervals of 4 min duration at a target exercise intensity of 90 to 95% HRmax were completed on a treadmill. The total center of pressure (COP) path length displacement served as standing balance performance outcome. In order to assess ankle muscle coordination patterns, amplitude ratios (AR) were calculated for each muscle (e.g. tibialis anterior (TA) [%] = (TA × 100)/(gastrocnemius medialis (GM) + soleus (SOL) + peroneus longus (PL) + TA). The co-activation was calculated for the SOL and TA muscles computing the co-activation index (CAI = 2 × TA/TA + SOL). Seniors showed an inverted ankle muscle coordination pattern during single limb stance with eyes open (SLEO), compared to young adults (rest: GM, S: 15 ± 8% vs Y: 24 ± 9%; p = 0.03; SOL, S: 27 ± 14% vs Y: 37 ± 18%; p = 0.009; TA, S: 31 ± 13% vs Y: 13 ± 7%; p = 0.003). These patterns did not change after a high-intensity training session. A moderate correlation between amplitude ratios of the TA-contribution and postural sway was observed for seniors during SLEO (r = 0.61). Ankle co-activation was twofold elevated in seniors compared to young adults during SLEO (p Seniors with decreased postural control showed higher TA

Natural course of untreated cluster headache: A retrospective cohort study.

Science.gov (United States)

Lee, Mi Ji; Choi, Hyun Ah; Shin, Jong Hwa; Park, Hea Ree; Chung, Chin-Sang

2018-04-01

Objective To determine the natural course of cluster headache. Methods We screened patients with cluster headache who were diagnosed at Samsung Medical Center and lost to follow-up for ≥5 years. Eligible patients were interviewed by phone about the longitudinal changes in headache characteristics and disease course. Remission was defined as symptom-free 1) for longer than twice the longest between-bout period and 2) for ≥5 years. Results Forty-two patients lost to follow-up for mean 7.5 (range, 5.0-15.7) years were included. The length of the last bout did not differ from the first one, while the last between-bout period was longer than the first one ( p = 0.012). Characteristics of cluster headache decreased over time: Side-locked unilaterality (from 92.9% to 78.9%), seasonal and circadian rhythmicity (from 63.9% to 60.9% and from 62.2 to 40.5%, respectively), and autonomic symptoms (from 95.2% to 75.0%). Remission occurred in 14 (33.3%) patients at a mean age of 42.3 (range, 27-65) years, which was not different from the age of last bouts in active patients ( p = 0.623). There was a trend for more seasonal and circadian predilection at baseline in the active group ( p = 0.056 and 0.063, respectively) and fewer lifetime bouts and shorter disease duration in patients in remission ( p = 0.063 and 0.090). Conclusions This study first shows the natural courses of cluster headache. Features of cluster headache become less prominent over time. Remission occurred regardless of age. Although no single predictor of remission was found, our data suggest that remission of cluster headache might not be a consequence of more advanced age, longer duration of disease, or accumulation of lifetime bouts.

Elevated temperature intensity, timing, and duration of exposure affect soybean internode elongation, mainstem node number, and pod number per plant

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Leon Hartwell Allen, Jr.

2018-04-01

Full Text Available A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville, FL, USA to investigate how a soybean (Glycine max L. Merr. cultivar, Maverick (maturity group III, indeterminate, responded to three elevated temperatures, ELT, (day/night of 34/26 °C, 38/30 °C, and 42/34 °C in comparison to a control growth temperature (30/22 °C. Carbon dioxide (CO2 concentration was maintained at 700 μmol mol−1 in each compartment by a processor controlled air-sampling and CO2-injection system. Three sequential experiments were conducted at different times of year (summer, autumn, and early spring to investigate the effect of intensity, timing, and duration of ELT on soybean node number, internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity, whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage (R1–R2 or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. Short-term (10-day duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number (internode number are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem length. Furthermore, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C (and

Heart rate variability in stroke patients submitted to an acute bout of aerobic exercise.

Science.gov (United States)

Raimundo, Rodrigo Daminello; de Abreu, Luiz Carlos; Adami, Fernando; Vanderlei, Franciele Marques; de Carvalho, Tatiana Dias; Moreno, Isadora Lessa; Pereira, Valdelias Xavier; Valenti, Vitor Engracia; Sato, Monica Akemi

2013-10-01

Stroke has been associated with cardiac autonomic impairment due to damage in central nervous system. Dysfunction in heart rate variability (HRV) may reflect dysfunction of the autonomic nervous system. Aerobic training has been used in the rehabilitation procedure of patients, due to improvement of aerobic function and other beneficial effects as increased recruitment of motor units, favoring the development of muscle fibers. The purpose of this study was to evaluate the cardiac autonomic modulation in patients with stroke before, during, and after an acute bout of aerobic exercise. The heart rate of 38 stroke patients was recorded using a heart rate (HR) monitor and the data were used to assess cardiac autonomic modulation through HRV analysis. The patients were in supine position and remained at resting condition (R) for 10 min before starting the experiment. Afterwards, they were submitted to walking exercise (E) on a treadmill until achieve 50-70% of maximum heart rate. After 30 min of aerobic exercise, the subjects were advised to remain in supine position for additional 30 min in order to record the HR during the recovery (RC) period. The recordings were divided in three periods: RC1, immediately after the end of exercise bout, RC2, between 12 and 17 min of recovery, and RC3, at the final 5 min of recovery. A significant decrease was observed during exercise in the MeanRR index (577.3±92 vs. 861.1+109), RRtri (5.1±2 vs. 9.1±3), high frequency component (11.2±4 vs. 167±135 ms) and SD1 (5.7±2 vs. 16.9±7 ms) compared to resting values. The SDNN index reduced during E (27.6±19) and RC1 (29.9±11), RC2 (27.9±9) and RC3 (32.4±13) compared to resting values (42.4±19). The low frequency component increased during E (545±82), but decreased during RC1 (166.3±129), RC2 (206.9±152), and RC3 (249.5±236) compared to R levels (394.6±315). These findings suggest that stroke patients showed a reduced HRV during and at least 30 min after exercise, due to an

How does the duration of active pushing in labor affect neonatal outcomes?

Science.gov (United States)

Yli, Branka M; Kro, Grete A Birkeland; Rasmussen, Svein; Khoury, Janette; Norèn, Håkan; Amer-Wåhlin, Isis; Saugstad, Ola Didrik; Stray-Pedersen, Babill

2011-11-19

To assess the effect of time of active pushing (TAP) on neonatal outcome. The study population (n=36,432) was taken from a Swedish randomized control trial on intrapartum monitoring, a European Union fetal electrocardiogram trial, and from Mölndal Hospital. After validation of acid-base samples and TAP, 22,812 cases were accepted for analysis. The median active TAP was 36 min for P0 and 13 min for P≥1 (Ppushing for 15-29 min (n=6589) relative to pushing for 12 mmol/L to 3.5 (95% CI 1.3-9.0). The group with a cord artery pH of 15 min), while the probability of a spontaneous vaginal delivery decreased with the duration of pushing. We suggest active physiological evaluation of the labor progress together with continuous electronic fetal monitoring during pushing irrespective of guideline thresholds.

Duration reproduction with sensory feedback delay: Differential involvement of perception and action time

Directory of Open Access Journals (Sweden)

Stephanie eGanzenmüller

2012-10-01

Full Text Available Previous research has shown that voluntary action can attract subsequent, delayed feedback events towards the action, and adaptation to the sensorimotor delay can even reverse motor-sensory temporal-order judgments. However, whether and how sensorimotor delay affects duration reproduction is still unclear. To investigate this, we injected an onset- or offset-delay to the sensory feedback signal from a duration reproduction task. We compared duration reproductions within (visual, auditory modality and across audiovisual modalities with feedback signal onset- and offset-delay manipulations. We found that the reproduced duration was lengthened in both visual and auditory feedback signal onset-delay conditions. The lengthening effect was evident immediately, on the first trial with the onset delay. However, when the onset of the feedback signal was prior to the action, the lengthening effect was diminished. In contrast, a shortening effect was found with feedback signal offset-delay, though the effect was weaker and manifested only in the auditory offset-delay condition. These findings indicate that participants tend to mix the onset of action and the feedback signal more when the feedback is delayed, and they heavily rely on motor-stop signals for the duration reproduction. Furthermore, auditory duration was overestimated compared to visual duration in crossmodal feedback conditions, and the overestimation of auditory duration (or the underestimation of visual duration was independent of the delay manipulation.

Mechanically induced intracellular calcium waves in osteoblasts demonstrate calcium fingerprints in bone cell mechanotransduction.

Science.gov (United States)

Godin, Lindsay M; Suzuki, Sakiko; Jacobs, Christopher R; Donahue, Henry J; Donahue, Seth W

2007-11-01

An early response to mechanical stimulation of bone cells in vitro is an increase in intracellular calcium concentration ([Ca (2+)](i)). This study analyzed the [Ca (2+)](i) wave area, magnitude, duration, rise time, fall time, and time to onset in individual osteoblasts for two identical bouts of mechanical stimulation separated by a 30-min rest period. The area under the [Ca (2+)](i) wave increased in the second loading bout compared to the first. This suggests that rest periods may potentiate mechanically induced intracellular calcium signals. Furthermore, many of the [Ca (2+)](i) wave parameters were strongly, positively correlated between the two bouts of mechanical stimulation. For example, in individual primary osteoblasts, if a cell had a large [Ca (2+)](i) wave area in the first bout it was likely to have a large [Ca (2+)](i) wave area in the second bout (r (2) = 0.933). These findings support the idea that individual bone cells have "calcium fingerprints" (i.e., a unique [Ca (2+)](i) wave profile that is reproducible for repeated exposure to a given stimulus).

Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula

Czech Academy of Sciences Publication Activity Database

Konvalinková, Tereza; Püschel, David; Janoušková, Martina; Gryndler, Milan; Jansa, Jan

2015-01-01

Roč. 6, FEB 13 (2015), s. 1-11 ISSN 1664-462X R&D Projects: GA MŠk(CZ) LK11224 Institutional support: RVO:61388971 Keywords : arbuscular mycorrhizal symbiosis * light intensity * shading duration Subject RIV: EE - Microbiology, Virology Impact factor: 4.495, year: 2015

The duration of reionization constrains the ionizing sources

Science.gov (United States)

Sharma, Mahavir; Theuns, Tom; Frenk, Carlos

2018-03-01

We investigate how the nature of the galaxies that reionized the Universe affects the duration of reionization. We contrast two sets of models: one in which galaxies on the faint side of the luminosity function dominate the ionizing emissivity, and a second in which the galaxies on the bright side of the luminosity function dominate. The faint-end of the luminosity function evolves slowly, therefore the transition from mostly neutral to mostly ionized state takes a much longer time in the first set of models compared to the second. Existing observational constraints on the duration of this transition are relatively weak, but taken at face value prefer the model in which galaxies on the bright side play a major role. Measurements of the kinetic Sunyaev Zeldovich effect in the cosmic microwave background from the epoch of reionization also point in the same direction.

The duration of reionization constrains the ionizing sources

Science.gov (United States)

Sharma, Mahavir; Theuns, Tom; Frenk, Carlos

2018-06-01

We investigate how the nature of the galaxies that reionized the Universe affects the duration of reionization. We contrast two sets of models: one in which galaxies on the faint side of the luminosity function dominate the ionizing emissivity, and a second in which the galaxies on the bright side of the luminosity function dominate. The faint end of the luminosity function evolves slowly, therefore the transition from mostly neutral to mostly ionized state takes a much longer time in the first set of models compared to the second. Existing observational constraints on the duration of this transition are relatively weak, but taken at face value prefer the model in which galaxies on the bright side play a major role. Measurements of the kinetic Sunyaev-Zeldovich effect in the cosmic microwave background from the epoch of reionization also point in the same direction.

Duration judgements over multiple elements

Directory of Open Access Journals (Sweden)

Inci eAyhan

2012-11-01

Full Text Available We investigated the limits of the number of events observers can simultaneously time. For single targets occurring in one of eight positions sensitivity to duration was improved for spatially pre-cued items as compared to post-cued items indicating that exogenous driven attention can improve duration discrimination. Sensitivity to duration for pre-cued items was also marginally better for single items as compared to eight items indicating that even after the allocation of focal attention, distracter items can interfere with the encoding of duration. For an eight item array discrimination was worse for post-cued locations as compared to pre-cued locations indicating both that attention can improve duration discrimination performance and that it was not possible to access a perfect memory trace of the duration of eight elements. The interference from the distracters in the pre-cued eight item array may reflect some mandatory averaging of target and distracter events. To further explore duration averaging we asked subjects to explicitly compare average durations of multiple item arrays against a single item standard duration. Duration discrimination thresholds were significantly lower for single elements as compared to multiple elements, showing that averaging, either automatically or intentionally, impairs duration discrimination. There was no set size effect. Performance was the same for averages of two and eight items, but performance with even an average of two items was worse than for one item. This was also true for sequential presentation indicating poor performance was not due to limits on the division of attention across items. Rather performance appears to be limited by an inability to remember or aggregate duration information from two or more items. Although it is possible to manipulate perceived duration locally, there appears to be no perceptual mechanisms for aggregating local durations across space.

Strategies for improving performance in long duration events: Olympic distance triathlon.

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Hausswirth, Christophe; Brisswalter, Jeanick

2008-01-01

This review focuses on strategic aspects that may affect performance in a long-duration Olympic event, the Olympic distance triathlon. Given the variety of races during the Olympic Games triathlon, strategic aspects include improving technological features as well as energetics factors affecting overall triathlon performance. During the last decade, many studies have attempted to identify factors reducing the metabolic load associated (or not) with the development of fatigue process by analysing the relationship between metabolic and biomechanical factors with exercise duration. To date, a consensus exists about the benefit of adopting a drafting position during the swimming or the cycling part of the triathlon. Other potential strategic factors, such as the production of power output or the selection of cadence during the cycling or the running leg, are likely to affect the overall triathlon performance. Within this approach, pacing strategies are observed by elite athletes who swim or cycle in a sheltered position, inducing several changes of pace, intensity or stochastic shifts in the amplitude of the physiological responses. The analysis of these parameters appears to arouse some experimental and practical interest from researchers and coachers, especially for long-distance Olympic events.

Physical activity and negative affective reactivity in daily life.

Science.gov (United States)

Puterman, Eli; Weiss, Jordan; Beauchamp, Mark R; Mogle, Jacqueline; Almeida, David M

2017-12-01

The results from experimental studies indicate that physically active individuals remain calmer and report less anxiety after the induction of a standardized stressor. The current study extends this research to real life, and examines whether daily physical activity attenuates negative affect that occurs in response to naturally occurring daily stressors. The current study used data from the second wave of the National Study of Daily Experiences, a sub-study of the second wave of the Midlife in the United States Study (MIDUS-II) of 2,022 individuals aged 33-84 questioned nightly for eight consecutive days about their general affect and affective responses to stressful events and their engagement in physical activity. Results indicated that while negative affect is significantly elevated on days with stressful events compared to days free of events in all individuals, these effects are attenuated in those who remain physically active when compared to those who were underactive. This was also true for any day participants were physically active. Importantly, negative affect in response to any specific stressor was reduced the closer in time that the stressor occurred to the bout of exercise in underactive participants, while, in active participants, negative affect in response to any stressor remained low throughout the entire day that participants reported that they were active. Given the significant mental and physical health implications of elevated affective reactivity observed in previous studies, the current study sheds further light on the importance of remaining physically active in times of stress. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effects of Electronic Cigarette Liquid Nicotine Concentration on Plasma Nicotine and Puff Topography in Tobacco Cigarette Smokers: A Preliminary Report.

Science.gov (United States)

Lopez, Alexa A; Hiler, Marzena M; Soule, Eric K; Ramôa, Carolina P; Karaoghlanian, Nareg V; Lipato, Thokozeni; Breland, Alison B; Shihadeh, Alan L; Eissenberg, Thomas

2016-05-01

Electronic cigarettes (ECIGs) aerosolize a liquid that usually contains propylene glycol and/or vegetable glycerin, flavorants, and the dependence-producing drug nicotine in various concentrations. This study examined the extent to which ECIG liquid nicotine concentration is related to user plasma nicotine concentration in ECIG-naïve tobacco cigarette smokers. Sixteen ECIG-naïve cigarette smokers completed four laboratory sessions that differed by the nicotine concentration of the liquid (0, 8, 18, or 36 mg/ml) that was placed into a 1.5 Ohm, dual coil "cartomizer" powered by a 3.3V battery. In each session, participants completed two, 10-puff ECIG use bouts with a 30-second inter-puff interval; bouts were separated by 60 minutes. Venous blood was sampled before and after bouts for later analysis of plasma nicotine concentration; puff duration, volume, and average flow rate were measured during each bout. In bout 1, relative to the 0mg/ml nicotine condition (mean = 3.8 ng/ml, SD = 3.3), plasma nicotine concentration increased significantly immediately after the bout for the 8 (mean = 8.8 ng/ml, SD = 6.3), 18 (mean = 13.2 ng/ml, SD = 13.2), and 36 mg/ml (mean = 17.0 ng/ml, SD = 17.9) liquid concentration. A similar pattern was observed after bout 2. Average puff duration in the 36 mg/ml condition was significantly shorter compared to the 0mg/ml nicotine condition. Puff volume increased during the second bout for 8 and 18 mg/ml conditions. For a given ECIG device, nicotine delivery may be directly related to liquid concentration. ECIG-naïve cigarette smokers can, from their first use bout, attain cigarette-like nicotine delivery profiles with some currently available ECIG products. Liquid nicotine concentration can influence plasma nicotine concentration in ECIG-naïve cigarette smokers, and, at some concentrations, the nicotine delivery profile of a 3.3V ECIG with a dual coil, 1.5-Ohm cartomizer approaches that of a combustible tobacco cigarette in this

β1-Adrenoceptor autoantibodies affect action potential duration and delayed rectifier potassium currents in guinea pigs.

Science.gov (United States)

Zhao, Yuhui; Huang, Haixia; Du, Yunhui; Li, Xiao; Lv, Tingting; Zhang, Suli; Wei, Hua; Shang, Jianyu; Liu, Ping; Liu, Huirong

2015-01-01

β1-Adrenoceptor autoantibodies (β1-AAs) affect the action potential duration (APD) in cardiomyocytes and are related to ventricular arrhythmias. The delayed rectifier potassium current (I K) plays a crucial role in APD, but the effects of β1-AAs on I K have not been completely illuminated. This work aimed to observe the effects of β1-AAs on I K and APD and further explore the mechanisms of β1-AA-mediated ventricular arrhythmias. β1-AAs were obtained from sera of patients with coronary heart disease (CHD) and nonsustained ventricular tachycardia. With whole-cell patch clamp technique, action potentials and I K were recorded. The results illustrated 0.1 μmol/L β1-AAs shortened APD at 50 % (APD50) and 90 % (APD90) of the repolarization. However, at 0.01 μmol/L, β1-AAs had no effects on either APD90 or APD50 (P > 0.05). At 0.001 μmol/L, β1-AAs significantly prolonged APD90 and APD50. Moreover, β1-AAs (0.001, 0.01, 0.1 μmol/L) dose-dependently increased the rapidly activating delayed rectifier potassium current (I Kr), but similarly decreased the slowly activating delayed rectifier potassium current (I Ks) and increased L-type calcium currents at the different concentrations. Taken together, the IKr increase induced by high β1-AA concentrations is responsible for a significant APD reduction which would contribute to repolarization changes and trigger the malignant ventricular arrhythmias in CHD patients.

Out of mind, out of heart: Attention affects duration of emotional experience

OpenAIRE

Freund, Alexandra M; Keil, Andreas

2013-01-01

It has been suggested that the extent to which a person maintains attention to pleasant versus unpleasant aspects of a given stimulus has an effect on the self-reported affective state. This assumption was empirically tested in two experiments. In Study 1, participants received the instruction either to focus on a positive emotion-eliciting event (winning a tournament chess game) or to focus their attention on an affectively neutral distraction task (describing drawings). Study 2 used negativ...

Relationships of feeding behaviors with average daily gain, dry matter intake, and residual feed intake in Red Angus-sired cattle.

Science.gov (United States)

McGee, M; Welch, C M; Ramirez, J A; Carstens, G E; Price, W J; Hall, J B; Hill, R A

2014-11-01

Feeding behavior has the potential to enhance prediction of feed intake and to improve understanding of the relationships between behavior, DMI, ADG, and residual feed intake (RFI) in beef cattle. Two cohorts, born in 2009 and 2010, the progeny of Red Angus bulls (n = 58 heifers and n = 53 steers), were evaluated during the growing phase, and the latter group of steers was also evaluated during the finishing phase. All behavior analyses were based on 7 feeding behavior traits (bunk visit frequency, bunk visit duration [BVDUR], feed bout frequency, feed bout duration, meal frequency, meal duration, and average meal intake) and their relationships with ADG, DMI, and RFI. During the growing phase, feeding duration traits were most indicative of DMI with positive correlations between BVDUR and DMI for cohort 1 steers, growing phase (n = 28, r = 0.52, P = 0.00); cohort 2 steers, growing phase (n = 25, r = 0.44, P = 0.01); and cohort 2 heifers, growing phase (n = 29, r = 0.28 P = 0.05). There were similar trends toward correlation of BVDUR and RFI for both steer groups and cohort 1 heifers, growing phase (C1HG; n = 29; r = 0.27, P = 0.06; r = 0.30, P = 0.07; and r = 0.26, P = 0.08, respectively). Feed bout frequency was correlated with ADG in C1HG and in cohort 2 steers, finishing phase (r = -0.31, P = 0.04, and r = 0.43, P = 0.01, respectively). Feed bout duration was correlated with ADG in heifer groups (r = 0.29 and r = 0.28, P = 0.05 for both groups) and DMI for all growing phase animals (r = 0.29 to 0.55, P ≤ 0.05 for all groups). Evaluation of growing vs. finishing phase steer groups suggests that all behaviors, RFI, and DMI, but not ADG, are correlated through the growing and finishing phases (P ≤ 0.01 for all variables excluding ADG), implying that feeding behaviors determined during the growing phase are strong predictors of DMI in either life stage. Sire maintenance energy EPD effects (measured as high or low groups) on progeny feeding behaviors revealed a

The Moderating Influence of Situational Motivation on the Relationship Between Preferred Exercise and Positive Affect

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Eva Guérin

2013-10-01

Full Text Available Despite convincing evidence supporting the association between exercise and positive affect, this complex relationship requires further theoretical and person-centered explanation. The nature of one’s motivation for exercise, as postulated by Self-Determination Theory (SDT, may supply a missing and understudied link. The primary aim of this experimental study was to examine the moderating influence of situational motivation from SDT on the relationship between an acute bout of preferred exercise, namely running (vs. control, and changes in positive affect. Forty-one active women attended two sessions to engage in (a a 30-min moderate-intensity self-paced treadmill run and (b a 30-min quiet activity (i.e., newspaper reading. Participants with high introjection versus those with low introjection reported a greater increase in positive affect from pre- to postrunning and a greater decrease in positive affect from pre- to postcontrol. A “relief from guilt” effect was postulated to explain these results. Motivational variables accounted for 7% of variance in postrun positive affect. Consistent with SDT, running because one values this behavior and its benefits (i.e., identified regulation was significantly associated with postrun positive affect.

Reduced Tic Symptomatology in Tourette Syndrome After an Acute Bout of Exercise: An Observational Study.

Science.gov (United States)

Nixon, Elena; Glazebrook, Cris; Hollis, Chris; Jackson, Georgina M

2014-03-01

In light of descriptive accounts of attenuating effects of physical activity on tics, we used an experimental design to assess the impact of an acute bout of aerobic exercise on tic expression in young people (N = 18) with Tourette Syndrome (TS). We compared video-based tic frequency estimates obtained during an exercise session with tic rates obtained during pre-exercise (baseline) and post-exercise interview-based sessions. Results showed significantly reduced tic rates during the exercise session compared with baseline, suggesting that acute exercise has an attenuating effect on tics. Tic rates also remained reduced relative to baseline during the post-exercise session, likely reflecting a sustained effect of exercise on tic reduction. Parallel to the observed tic attenuation, exercise also had a beneficial impact on self-reported anxiety and mood levels. The present findings provide novel empirical evidence for the beneficial effect of exercise on TS symptomatology bearing important research and clinical implications. © The Author(s) 2014.

Prevalence of Healthy Sleep Duration among Adults--United States, 2014.

Science.gov (United States)

Liu, Yong; Wheaton, Anne G; Chapman, Daniel P; Cunningham, Timothy J; Lu, Hua; Croft, Janet B

2016-02-19

To promote optimal health and well-being, adults aged 18-60 years are recommended to sleep at least 7 hours each night (1). Sleeping disease, stroke, frequent mental distress, and all-cause mortality (2-4). Insufficient sleep impairs cognitive performance, which can increase the likelihood of motor vehicle and other transportation accidents, industrial accidents, medical errors, and loss of work productivity that could affect the wider community (5). CDC analyzed data from the 2014 Behavioral Risk Factor Surveillance System (BRFSS) to determine the prevalence of a healthy sleep duration (≥ 7 hours) among 444,306 adult respondents in all 50 states and the District of Columbia. A total of 65.2% of respondents reported a healthy sleep duration; the age-adjusted prevalence of healthy sleep was lower among non-Hispanic blacks, American Indians/Alaska Natives, Native Hawaiians/Pacific Islanders, and multiracial respondents, compared with non-Hispanic whites, Hispanics, and Asians. State-based estimates of healthy sleep duration prevalence ranged from 56.1% in Hawaii to 71.6% in South Dakota. Geographic clustering of the lowest prevalence of healthy sleep duration was observed in the southeastern United States and in states along the Appalachian Mountains, and the highest prevalence was observed in the Great Plains states. More than one third of U.S. respondents reported typically sleeping sleep health; worksite shift policies that ensure healthy sleep duration for shift workers, particularly medical professionals, emergency response personnel, and transportation industry personnel; and opportunities for health care providers to discuss the importance of healthy sleep duration with patients and address reasons for poor sleep health.

Urbanization effect on trends in sunshine duration in China

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Y. Wang

2017-07-01

Full Text Available There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as dimming and brightening periods, are a large-scale or solely local phenomenon. We investigated this issue using long-term sunshine duration records from China, which experienced a rapid increase in urbanization during the past decades. Over the period 1960–2013, 172 pairs of urban and nearby rural stations were analyzed. Urban and rural sunshine duration trends show similar spatial patterns during a dimming phase (1960–1989 and a subsequent period during which trends were leveling off (1990–2013. This indicates that rather than local effects, the trends in sunshine duration are on more of a national or regional scale in China. Nevertheless, in the dimming phase, the declining rate of sunshine duration in rural areas is around two-thirds of that in urban areas. The ratio of rural to urban dimming generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization calculated based on the year 2013. It reaches a maximum when the urbanization level exceeds 50 %, the urban population exceeds 20 million, or the population density becomes higher than 250 person km−2. After the transition into the leveling-off period, sunshine duration trends are no longer significantly affected by urbanization. Meanwhile, the number of laws and regulations related to air pollution and investment in pollution treatment have been increasing in China.

Twenty-four hour total and dietary fat oxidation in lean, obese and reduced-obese adults with and without a bout of exercise.

Directory of Open Access Journals (Sweden)

Audrey Bergouignan

Full Text Available It has been hypothesized that obese and reduced-obese individuals have decreased oxidative capacity, which contributes to weight gain and regain. Recent data have challenged this concept.To determine (1 whether total and dietary fat oxidation are decreased in obese and reduced-obese adults compared to lean but increase in response to an acute exercise bout and (2 whether regular physical activity attenuates these metabolic alterations.We measured 24-hr total (whole-room calorimetry and dietary fat (14C-oleate oxidation in Sedentary Lean (BMI = 21.5±1.6; n = 10, Sedentary Obese (BMI = 33.6±2.5; n = 9, Sedentary Reduced-Obese (RED-SED; BMI = 26.9±3.7; n = 7 and in Physically Active Reduced-Obese (RED-EX; BMI = 27.3±2.8; n = 12 men and women with or without an acute exercise bout where energy expended during exercise was not replaced.Although Red-SED and Red-EX had a similar level of fatness, aerobic capacity and metabolic profiles were better in Red-EX only compared to Obese subjects. No significant between-group differences were seen in 24-hr respiratory quotient (RQ, Lean: 0.831±0.044, Obese: 0.852±0.023, Red-SED: 0.864±0.037, Red-EX: 0.842±0.039, total and dietary fat oxidation. A single bout of exercise increased total (+27.8%, p<0.0001 and dietary (+6.6%, p = 0.048 fat oxidation across groups. Although exercise did not impact RQ during the day, it decreased RQ during sleep (p = 0.01 in all groups. Red-EX oxidized more fat overnight than Red-SED subjects under both resting (p = 0.036 and negative energy balance (p = 0.003 conditions, even after adjustment for fat-free mass.Obese and reduced-obese individuals oxidize as much fat as lean both under eucaloric and negative energy balance conditions, which does not support the hypothesis of reduced oxidative capacity in these groups. Reduced-obese individuals who exercise regularly have markers of metabolic health similar to those seen in lean

Reactor shell model response to inner loading with impulses of various origin and duration

International Nuclear Information System (INIS)

Ryzhanskij, V.A.; Ivanov, A.G.; Uskov, A.A.; Kharlamov, M.V.; Novikov, V.V.; Pozharskij, A.N.

1994-01-01

The reaction of reactor vessel mockup towards internal pulsed loading simulating emergency nuclear power release burst is experimentally studied. Four types of non-nuclear pulsed power release sources are used in the experiments. It is revealed that the nature and duration of power release pulse affect greatly its efficiency. A semi-empirical formula describing the interrelation between power release efficiency and duration depending on its nature is derived. 11 refs., 1 tab., 3 figs

Associations of office workers' objectively assessed occupational sitting, standing and stepping time with musculoskeletal symptoms.

Science.gov (United States)

Coenen, Pieter; Healy, Genevieve N; Winkler, Elisabeth A H; Dunstan, David W; Owen, Neville; Moodie, Marj; LaMontagne, Anthony D; Eakin, Elizabeth A; O'Sullivan, Peter B; Straker, Leon M

2018-04-22

We examined the association of musculoskeletal symptoms (MSS) with workplace sitting, standing and stepping time, as well as sitting and standing time accumulation (i.e. usual bout duration of these activities), measured objectively with the activPAL3 monitor. Using baseline data from the Stand Up Victoria trial (216 office workers, 14 workplaces), cross-sectional associations of occupational activities with self-reported MSS (low-back, upper and lower extremity symptoms in the last three months) were examined using probit regression, correcting for clustering and adjusting for confounders. Sitting bout duration was significantly (p < 0.05) associated, non-linearly, with MSS, such that those in the middle tertile displayed the highest prevalence of upper extremity symptoms. Other associations were non-significant but sometimes involved large differences in symptom prevalence (e.g. 38%) by activity. Though causation is unclear, these non-linear associations suggest that sitting and its alternatives (i.e. standing and stepping) interact with MSS and this should be considered when designing safe work systems. Practitioner summary: We studied associations of objectively assessed occupational activities with musculoskeletal symptoms in office workers. Workers who accumulated longer sitting bouts reported fewer upper extremity symptoms. Total activity duration was not significantly associated with musculoskeletal symptoms. We underline the importance of considering total volumes and patterns of activity time in musculoskeletal research.

Infant pain-related negative affect at 12 months of age: early infant and caregiver predictors.

Science.gov (United States)

Din Osmun, Laila; Pillai Riddell, Rebecca; Flora, David B

2014-01-01

To examine the predictive relationships of early infant and caregiver variables on expressed pain-related negative affect duration at the 12-month immunization. Infants and their caregivers (N = 255) were followed during immunization appointments over the first year of life. Latent growth curve modeling in a structural equation modeling context was used. Higher levels of initial infant pain reactivity at 2 months and caregiver emotional availability averaged across 2, 4, and 6 months of age were related to larger decreases in the duration of infant negative affect over the first 6 months of life. Longer duration of infant negative affect at 2 months and poorer regulation of infant negative affect over the first 6 months of life predicted longer durations of infant negative affect by 12 months. Infant negative affect at 12 months was a function of both infant factors and the quality of caregiver interactive behaviors (emotional availability) in early infancy.

Evaluation of different pre-slaughter light intensities and fasting duration in broilers

Directory of Open Access Journals (Sweden)

IB Ramão

2011-12-01

Full Text Available The aim of this study was to determine the effects of different levels of light intensity (0, 5 or 20 lx and different pre-slaughter feed fasting duration (3, 6, 9, 12 and 15 hours on the parameters body weight loss, carcass yield, commercial cuts yield, water carcass retention, bacterial counts and breast meat pH. A number of 72 broiler chickens at 45 days of age (Cobb 500 strain was distributed in three chambers, in a total of 24 broilers per chamber. The results showed that feed fasting significantly influenced (p0.05. The presence of feed in the crop and gizzard did not depend on light intensity, but was affected by pre-slaughter feed fasting duration. Bacterial counts decreased with feed fasting duration (p<0.05.

The Effect of Task Duration on Event-Based Prospective Memory: A Multinomial Modeling Approach

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Hongxia Zhang

2017-11-01

Full Text Available Remembering to perform an action when a specific event occurs is referred to as Event-Based Prospective Memory (EBPM. This study investigated how EBPM performance is affected by task duration by having university students (n = 223 perform an EBPM task that was embedded within an ongoing computer-based color-matching task. For this experiment, we separated the overall task’s duration into the filler task duration and the ongoing task duration. The filler task duration is the length of time between the intention and the beginning of the ongoing task, and the ongoing task duration is the length of time between the beginning of the ongoing task and the appearance of the first Prospective Memory (PM cue. The filler task duration and ongoing task duration were further divided into three levels: 3, 6, and 9 min. Two factors were then orthogonally manipulated between-subjects using a multinomial processing tree model to separate the effects of different task durations on the two EBPM components. A mediation model was then created to verify whether task duration influences EBPM via self-reminding or discrimination. The results reveal three points. (1 Lengthening the duration of ongoing tasks had a negative effect on EBPM performance while lengthening the duration of the filler task had no significant effect on it. (2 As the filler task was lengthened, both the prospective and retrospective components show a decreasing and then increasing trend. Also, when the ongoing task duration was lengthened, the prospective component decreased while the retrospective component significantly increased. (3 The mediating effect of discrimination between the task duration and EBPM performance was significant. We concluded that different task durations influence EBPM performance through different components with discrimination being the mediator between task duration and EBPM performance.

Pre-attentive sensitivity to vowel duration reveals native phonology and predicts learning of second-language sounds.

Science.gov (United States)

Chládková, Kateřina; Escudero, Paola; Lipski, Silvia C

2013-09-01

In some languages (e.g. Czech), changes in vowel duration affect word meaning, while in others (e.g. Spanish) they do not. Yet for other languages (e.g. Dutch), the linguistic role of vowel duration remains unclear. To reveal whether Dutch represents vowel length in its phonology, we compared auditory pre-attentive duration processing in native and non-native vowels across Dutch, Czech, and Spanish. Dutch duration sensitivity patterned with Czech but was larger than Spanish in the native vowel, while it was smaller than Czech and Spanish in the non-native vowel. An interpretation of these findings suggests that in Dutch, duration is used phonemically but it might be relevant for the identity of certain native vowels only. Furthermore, the finding that Spanish listeners are more sensitive to duration in non-native than in native vowels indicates that a lack of duration differences in one's native language could be beneficial for second-language learning. Copyright © 2013 Elsevier Inc. All rights reserved.

Duration of multipacting processes and discharges in the linac of ions

International Nuclear Information System (INIS)

Lobzov, L.D.; Shulika, N.G.; Shulika, O.N.; Belan, V.N.

2009-01-01

It is experimentally shown that multipactor processes may be as harmful as other of parasitic discharges and cause significant disturbance in resonator electrodynamic characteristics of an accelerating structure. The disturbance may be evaluated by pulse-shape distortions of a reference rf voltage impulse. Control over duration of multipactor processes within diode gaps of a linac is effected by varying parameters of a self-sustained oscillation system formed by two independent positive feedback circuits (PFC). If two synchronous rf voltage pulses of given amplitude superpose in the accelerating structure, there occurs an impediment to multipactor processes. As this takes place, multipactor processes display minimal duration and do not affect acceleration stability.

Captive spider monkeys (Ateles geoffroyi) arm-raise to solicit allo-grooming.

Science.gov (United States)

Scheel, Matthew H; Edwards, Dori

2012-03-01

Old World monkeys solicit allo-grooming from conspecifics. However, there are relatively few studies of allo-grooming among spider monkeys, and descriptions of allo-grooming solicitation among spider monkeys are anecdotal. In this study, eighty-one hours of video, shot over eight weeks, captured 271 allo-grooming bouts among small groups of captive spider monkeys. Six of eight monkeys made heretofore unreported arm-raises that solicited higher than normal rates of allo-grooming. Allo-grooming bout durations following arm-raises also tended to be longer than bouts not preceded by arm-raises. The efficacy of the arm-raise at soliciting allo-grooming suggests spider monkeys are capable of intentional communication. Copyright © 2012 Elsevier B.V. All rights reserved.

Homework schedule: an important factor associated with shorter sleep duration among Chinese school-aged children.

Science.gov (United States)

Li, Shenghui; Yang, Qian; Chen, Zhe; Jin, Xingming; Jiang, Fan; Shen, Xiaoming

2014-09-03

This study was designed to examine the hypothesis that homework schedule has adverse impacts on Chinese children's sleep-wake habits and sleep duration. A random sample of 19,299 children aged 5.08 to 11.99 years old participated in a large, cross-sectional survey. A parent-administered questionnaire was completed to quantify children's homework schedule and sleep behaviors. Generally, it was demonstrated that more homework schedule was significantly associated with later bedtime, later wake time, and shorter sleep duration. Among all sleep variables, bedtime and sleep duration during weekdays appeared to be most affected by homework schedule, especially homework schedule during weekdays.

Sunshine Duration Variability in Haihe River Basin, China, during 1966–2015

Directory of Open Access Journals (Sweden)

Jing Ren

2017-10-01

Full Text Available Sunshine can have a profound impact on the systematic change in climate elements, such as temperature and wind speed, and in turn affects many aspects of the human society. In recent years, there has been a substantial interest in the variation of sunshine duration due to the dramatic global climate change. Hence, there is a need to better understand the variation of sunshine duration in order to cope with climate change. This study aimed to analyze the variation of sunshine duration in Haihe River basin, China, and its relationship with temperature, wind speed and low-level cloudiness. The annual, seasonal and monthly changes of sunshine duration were analyzed based on the data collected from 33 meteorological stations over the Haihe River basin during 1966–2015. It is evident that the annual, seasonal and monthly sunshine duration shows a decreasing trend over time. In addition, the annual sunshine duration is lower with a higher climate tendency rate in the southern and eastern coastal regions than that in the northwestern regions. It is negatively correlated with temperature (r = −0.50 and low-level cloudiness (r = −0.29, but positively with wind speed (r = 0.61. Wind speed may be one of the important causes of the decrease of sunshine duration in the Haihe River basin during 1966–2015. These changes may have significant implications for the hydrological cycle in the area.

The effects of odour and body posture on perceived duration

Directory of Open Access Journals (Sweden)

Eliane eSchreuder

2014-02-01

Full Text Available This study reports an examination of the internal clock model, according to which subjective time duration is influenced by attention and arousal state. In a time production task, we examine the hypothesis that an arousing odour and an upright body posture affect perceived duration.The experimental task was performed while participants were exposed to an odour and either sitting upright (arousing condition or lying down in a relaxing chair (relaxing condition. They were allocated to one of three experimental odour conditions: rosemary (arousing condition, peppermint (relaxing condition and no odour (control condition. The predicted effects of the odours were not borne out by the results. Self-reported arousal and pleasure states were measured before, during (after each body posture condition and post experimentally. Heart rate and skin conductance were measured before and during the experiment. As expected, odour had an effect on perceived duration. When participants were exposed to rosemary odour, they produced significantly shorter time intervals than in the no odour condition. This effect, however, could not be explained by increased arousal. There was no effect of body posture on perceived duration, even though body posture did induce arousal. The results do not support the proposed arousal mechanism of the internal clock model.

Game-based evaluation of personalized support for astronauts in long duration missions

NARCIS (Netherlands)

Smets, N.J.J.M.; Abbing, M.S.; Neerincx, M.A.; Lindenberg, J.; Oostendorp, H. van

2008-01-01

Long duration missions set high requirements for personalized astronaut support that takes into account the social, cognitive and affective state of the astronaut. Such support should be tested as thoroughly as possible before deployment into space. The in-orbit influences of the astronaut's state

Concurrent schedules of wheel-running reinforcement: choice between different durations of opportunity to run in rats.

Science.gov (United States)

Belke, Terry W

2006-02-01

How do animals choose between opportunities to run of different durations? Are longer durations preferred over shorter durations because they permit a greater number of revolutions? Are shorter durations preferred because they engender higher rates of running? Will longer durations be chosen because running is less constrained? The present study reports on three experiments that attempted to address these questions. In the first experiment, five male Wistar rats chose between 10-sec and 50-sec opportunities to run on modified concurrent variable-interval (VI) schedules. Across conditions, the durations associated with the alternatives were reversed. Response, time, and reinforcer proportions did not vary from indifference. In a second experiment, eight female Long-Evans rats chose between opportunities to run of equal (30 sec) and unequal durations (10 sec and 50 sec) on concurrent variable-ratio (VR) schedules. As in Experiment 1, between presentations of equal duration conditions, 10-sec and 50-sec durations were reversed. Results showed that response, time, and reinforcer proportions on an alternative did not vary with reinforcer duration. In a third experiment, using concurrent VR schedules, durations were systematically varied to decrease the shorter duration toward 0 sec. As the shorter duration decreased, response, time, and reinforcer proportions shifted toward the longer duration. In summary, differences in durations of opportunities to run did not affect choice behavior in a manner consistent with the assumption that a longer reinforcer is a larger reinforcer.

Exercise holds immediate benefits for affect and cognition in younger and older adults.

Science.gov (United States)

Hogan, Candice L; Mata, Jutta; Carstensen, Laura L

2013-06-01

Physical activity is associated with improved affective experience and enhanced cognitive processing. Potential age differences in the degree of benefit, however, are poorly understood because most studies examine either younger or older adults. The present study examined age differences in cognitive performance and affective experience immediately following a single bout of moderate exercise. Participants (144 community members aged 19 to 93) were randomly assigned to one of two experimental conditions: (a) exercise (15 min of moderate intensity stationary cycling) or (b) control (15 min completing ratings of neutral IAPS images). Before and after the manipulation, participants completed tests of working memory and momentary affect experience was measured. Results suggest that exercise is associated with increased levels of high-arousal positive affect (HAP) and decreased levels of low-arousal positive affect (LAP) relative to control condition. Age moderated the effects of exercise on LAP, such that younger age was associated with a drop in reported LAP postexercise, whereas the effects of exercise on HAP were consistent across age. Exercise also led to faster RTs on a working memory task than the control condition across age. Self-reported negative affect was unchanged. Overall, findings suggest that exercise may hold important benefits for both affective experience and cognitive performance regardless of age. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Monitoring the Impacts of Forest Management on Snowpack Duration

Science.gov (United States)

O'Halloran, T.; Tyler, S.; Gaffney, R.; Pai, H.

2017-12-01

Seasonal snowpack constitutes a significant portion of the hydrologic budget in mountain watersheds and influences dynamic (e.g., runoff magnitude and timing, soil moisture availability) and energetic processes (e.g., surface-atmosphere energy fluxes, ground temperature). Altered forest structure can affect snow accumulation and ablation. As part of a long-term monitoring project, this work examines the impact of forest management practices on snow cover in Lassen National Forest, California. We deployed a fiber optic distributed temperature sensing (DTS) cable and multiple meteorological stations in thinned, clear-cut, and untreated areas of forest. The DTS data was collected at 1 meter spatial intervals every 4 hours from February to May 2017. To determine snow cover, daily temperature variations were examined along locations of the DTS cable associated with our areas of interest. Between the various treatments, snow duration was greater in both clear-cut and untreated forest compared to the thinned area. However, snow duration varied by only six days. We also investigated other meteorological forcings, such as average winter temperature and precipitation, which coupled with forest modifications could explain snow duration in our study.

Couch potatoes do better: Delayed dispersal and territory size affect the duration of territory occupancy in a monogamous mammal.

Science.gov (United States)

Mayer, Martin; Zedrosser, Andreas; Rosell, Frank

2017-06-01

In territorial, socially monogamous species, the establishment and defense of a territory are an important strategy to maximize individual fitness, but the factors responsible for the duration of territory occupancy are rarely studied, especially in long-lived mammals. A long-term monitoring program in southeast Norway spanning over 18 years allowed us to follow the individual life histories of Eurasian beavers ( Castor fiber ) from adolescence in their natal family group to dispersal and territory establishment until the end of territory occupancy. We investigated whether territory size, resource availability, population density, and dispersal age could explain the duration of territory occupancy, which ranged from 1 to 11 years. The duration of territory occupancy was positively related to dispersal age, suggesting that individuals that delayed dispersal had a competitive advantage due to a larger body mass. This is in support with the maturation hypothesis, which states that an animal should await its physical and behavioral maturation before the acquisition of a territory. Further, we found that individuals that established in medium-sized territories occupied them longer as compared to individuals in small or large territories. This suggests that large territories are more costly to defend due to an increased patrolling effort, and small territories might not have sufficient resources. The lifetime reproductive success ranged from zero to six kits and generally increased with an increasing duration of territory occupancy. Our findings show the importance of holding a territory and demonstrate that dispersal decisions and territory selection have important consequences for the fitness of an individual.

Is the Relationship between Race and Continuous Positive Airway Pressure Adherence Mediated by Sleep Duration?

Science.gov (United States)

Billings, Martha E.; Rosen, Carol L.; Wang, Rui; Auckley, Dennis; Benca, Ruth; Foldvary-Schaefer, Nancy; Iber, Conrad; Zee, Phyllis; Redline, Susan; Kapur, Vishesh K.

2013-01-01

Study Objectives: Black race has been associated with decreased continuous positive airway pressure (CPAP) adherence. Short sleep duration, long sleep latency, and insomnia complaints may affect CPAP adherence as they affect sleep and opportunity to use CPAP. We assessed whether self-reported sleep measures were associated with CPAP adherence and if racial variations in these sleep characteristics may explain racial differences in CPAP adherence. Design: Analysis of data from a randomized controlled trial (HomePAP), which investigated home versus laboratory-based diagnosis and treatment of obstructive sleep apnea. Setting: Seven American Academy of Sleep Medicine-accredited sleep centers in five cities in the United States. Patients or Participants: Enrolled subjects (n = 191) with apnea-hypopnea index ≥ 15 and sleepiness (Epworth Sleepiness Scale > 12). Interventions: N/A. Measurements and Results: Multivariable regression was used to assess if subjective sleep measures and symptoms predicted 3-mo CPAP use. Mediation analysis was used to assess if sleep measures mediated the association of race with CPAP adherence. Black participants reported shorter sleep duration and longer sleep latency at baseline than white and Hispanic participants. Shorter sleep duration and longer sleep latency predicted worse CPAP adherence. Sleep duration mediated the association of black race with lower CPAP adherence. However, insomnia symptoms were not associated with race or CPAP adherence. Conclusions: Among subjects with similar severity of obstructive sleep apnea and sleepiness, baseline self-reported sleep duration and latency, but not perceived insomnia, predicted CPAP adherence over 3 mo. Sleep duration explains some of the observed differences in CPAP use by race. Sleep duration and latency should be considered when evaluating poor CPAP adherence. Clinical Trial Information: Portable Monitoring for Diagnosis and Management of Sleep Apnea (HomePAP) URL: http

Uncovering the genetic landscape for multiple sleep-wake traits.

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Christopher J Winrow

Full Text Available Despite decades of research in defining sleep-wake properties in mammals, little is known about the nature or identity of genes that regulate sleep, a fundamental behaviour that in humans occupies about one-third of the entire lifespan. While genome-wide association studies in humans and quantitative trait loci (QTL analyses in mice have identified candidate genes for an increasing number of complex traits and genetic diseases, the resources and time-consuming process necessary for obtaining detailed quantitative data have made sleep seemingly intractable to similar large-scale genomic approaches. Here we describe analysis of 20 sleep-wake traits from 269 mice from a genetically segregating population that reveals 52 significant QTL representing a minimum of 20 genomic loci. While many (28 QTL affected a particular sleep-wake trait (e.g., amount of wake across the full 24-hr day, other loci only affected a trait in the light or dark period while some loci had opposite effects on the trait during the light vs. dark. Analysis of a dataset for multiple sleep-wake traits led to previously undetected interactions (including the differential genetic control of number and duration of REM bouts, as well as possible shared genetic regulatory mechanisms for seemingly different unrelated sleep-wake traits (e.g., number of arousals and REM latency. Construction of a Bayesian network for sleep-wake traits and loci led to the identification of sub-networks of linkage not detectable in smaller data sets or limited single-trait analyses. For example, the network analyses revealed a novel chain of causal relationships between the chromosome 17@29cM QTL, total amount of wake, and duration of wake bouts in both light and dark periods that implies a mechanism whereby overall sleep need, mediated by this locus, in turn determines the length of each wake bout. Taken together, the present results reveal a complex genetic landscape underlying multiple sleep-wake traits

Association between Sleep Duration and Perceived Stress: Salaried Worker in Circumstances of High Workload

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Dong-Woo Choi

2018-04-01

Full Text Available The aim of this study was to find the association between sleep duration and perceived stress in salaried workers according to occupational categories and which lifestyle factors affected those correlations in South Korea. This study used data from the 2015 Community Health Survey (CHS. The self-reported sleep duration was used as the dependent variable in this study. We explored sleep duration and stress awareness among salaried workers, as well as household income and educational level with multiple logistic regression analysis. Salaried workers who slept for five or less hours had a higher odds ratio for high-stress awareness (OR: 1.86, 95% CI: 1.74–1.98. Stress awareness is associated with short sleep duration; specialized workers, office workers, those with above mid-high household income and graduate, university, or college level workers especially need to sleep adequately to manage stress.

The effect of study-test modalities on the remembrance of subjective duration from long-term memory.

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Klapproth, Florian

2002-07-31

It was examined whether stimulus modality (auditory vs. visual) affects the retrieval of subjective duration from memory. In two experiments the temporal generalization paradigm was used. Participants had to decide whether the previously learned standard duration (400 ms) occurred in the context of comparison stimuli. Two major results were found. (1) Discrimination was more accurate if the training and testing stimuli were of the same modality than if they were of opposite modalities. (2) If both modality of learning and modality of testing were different, subjects systematically underestimated the test durations, i.e. temporal generalization gradients (the proportion of identifications of a stimulus as the standard, plotted against stimulus duration) shifted to the right. The observed shift is interpreted as a result of a delayed timing process.

Characteristics of snow cover duration across the northeast United States of America

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Leathers, Daniel J.; Luff, Barbara L.

1997-11-01

The presence or absence of a snow cover affects a myriad of environmental and societal systems through its modification of the surface radiation balance and its ultimate impact on near-surface air temperatures. Daily snow cover data were collected for a network of 91 stations covering the northeast USA from Maine, south through to West Virginia. The snow cover data along with ancillary temperature, snowfall and precipitation data were used to investigate the characteristics of snow cover duration in this region and the effects of the snow cover on boundary layer climate variables for the snow cover seasons 1948-1949 through to 1987-1988.Results indicate that snow cover duration is variable in both space and time. The duration of a snow cover of 2.5 cm or greater varies from greater than 100 days in northern New England to less than 20 days across areas of Delaware, Maryland and West Virginia. Temporally, snow cover duration for the region as a whole was very short from the late 1940s through to the mid-1950s. From the late 1950s to the end of the period snow cover duration has varied around a consistent mean value. No long-term trends in snow cover duration are apparent in the record for the northeast USA.Principal components analysis and clustering techniques were utilized to isolate spatially coherent regions in which snow cover duration has varied similarly over the period of record. This analysis resulted in the identification of four snow-cover-duration regions across the northeast USA: including (i) the West Virginia area, (ii) the mid-Atlantic from southern New England through to western Pennsylvania, (iii) western and central New York and (iv) northern New England. Snow cover duration is shown to be highly associated with snowfall and temperature but not strongly related to total liquid precipitation. The intra-annual variability of snow cover duration is also investigated for each region.

Antecedent acute cycling exercise affects attention control: an ERP study using attention network test

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Yu-Kai eChang

2015-04-01

Full Text Available The purpose of this study was to investigate the after-effects of an acute bout of moderate-intensity aerobic cycling exercise on neuroelectric and behavioral indices of efficiency of three attentional networks: alerting, orienting, and executive (conflict control. Thirty young, highly fit amateur basketball players performed a multifunctional attentional reaction time task, the attention network test (ANT, with a two-group randomized experimental design after an acute bout of moderate-intensity spinning wheel exercise or without antecedent exercise. The ANT combined warning signals prior to targets, spatial cueing of potential target locations and target stimuli surrounded by congruent or incongruent flankers, which were provided to assess three attentional networks. Event-related brain potentials and task performance were measured during the ANT. Exercise resulted in a larger P3 amplitude in the alerting and executive control subtasks across frontal, central and parietal midline sites that was paralleled by an enhanced reaction speed only on trials with incongruent flankers of the executive control network. The P3 latency and response accuracy were not affected by exercise. These findings suggest that after spinning, more resources are allocated to task-relevant stimuli in tasks that rely on the alerting and executive control networks. However, the improvement in performance was observed in only the executively challenging conflict condition, suggesting that whether the brain resources that are rendered available immediately after acute exercise translate into better attention performance depends on the cognitive task complexity.

Does increasing active warm-up duration affect afternoon short-term maximal performance during Ramadan?

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Baklouti, Hana; Aloui, Asma; Chtourou, Hamdi; Briki, Walid; Chaouachi, Anis; Souissi, Nizar

2015-01-01

The purpose of this study was to examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the afternoon. Twelve healthy active men took part in the study. The experimental design consisted of four test sessions conducted at 5 p.m., before and during Ramadan, either with a 5-minute or a 15-minute warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. During each session, the subjects performed two vertical jump tests (squat jump and counter movement jump) for measurement of vertical jump height followed by a 30-second Wingate test for measurement of peak and mean power. Oral temperature was recorded at rest and after warming-up. Moreover, ratings of perceived exertion were obtained immediately after the Wingate test. Oral temperature was higher before Ramadan than during Ramadan at rest, and was higher after the 15-minute warm-up than the 5-minute warm-up both before and during Ramadan. In addition, vertical jump heights were not significantly different between the two warm-up conditions before and during Ramadan, and were lower during Ramadan than before Ramadan after both warm-up conditions. Peak and mean power were not significantly different between the two warm-up durations before Ramadan, but were significantly higher after the 5-minute warm-up than the 15-minute warm-up during Ramadan. Moreover, peak and mean power were lower during Ramadan than before Ramadan after both warm-up conditions. Furthermore, ratings of perceived exertion were higher after the 15-minute warm-up than the 5-minute warm-up only during Ramadan. The prolonged active warm-up has no effect on vertical jump height but impairs anaerobic power assessed during Ramadan in the afternoon.

Situational Motivation and Perceived Intensity: Their Interaction in Predicting Changes in Positive Affect from Physical Activity

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Eva Guérin

2012-01-01

Full Text Available There is evidence that affective experiences surrounding physical activity can contribute to the proper self-regulation of an active lifestyle. Motivation toward physical activity, as portrayed by self-determination theory, has been linked to positive affect, as has the intensity of physical activity, especially of a preferred nature. The purpose of this experimental study was to examine the interaction between situational motivation and intensity [i.e., ratings of perceived exertion (RPE] in predicting changes in positive affect following an acute bout of preferred physical activity, namely, running. Fourty-one female runners engaged in a 30-minute self-paced treadmill run in a laboratory context. Situational motivation for running, pre- and post-running positive affect, and RPE were assessed via validated self-report questionnaires. Hierarchical regression analyses revealed a significant interaction effect between RPE and introjection (P<.05 but not between RPE and identified regulation or intrinsic motivation. At low levels of introjection, the influence of RPE on the change in positive affect was considerable, with higher RPE ratings being associated with greater increases in positive affect. The implications of the findings in light of SDT principles as well as the potential contingencies between the regulations and RPE in predicting positive affect among women are discussed.

Calves Use an Automated Brush and a Hanging Rope When Pair-Housed

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Gosia Zobel

2017-11-01

Full Text Available Calf housing often only meets the basic needs of calves, but there is a growing interest in providing enrichments. This study described the behaviour of calves when they were given the opportunity to interact with two commonly available enrichment items. Female and male calves (approximately 11 days old were pair-housed in 8 identical pens fitted with an automated brush and a hanging rope. Frequency and duration of behaviours were recorded on 3 separate days (from 12:00 until 08:00 the following day. Calves spent equal time using the brush and rope (27.1 min/day, but there was less variation in the use of the brush as opposed to the rope (coefficient of variation, CV: 23 vs. 78%, respectively. Calves had more frequent (94 bouts, CV: 24% and shorter (17.8 s/bout, CV: 24% brush use bouts compared to fewer (38 bouts, CV: 43% and longer (38.3 s/bout, CV: 53% rope use bouts. There was a diurnal pattern of use for both items. Frequency of play was similar to rope use, but total time playing was 8% of rope and brush use. Variability among calves suggested that individual preference existed; however, the social dynamics of the pair-housed environment were not measured and therefore could have influenced brush and rope use. Multiple enrichment items should be considered when designing improvements to calf housing.

Elevated dopamine alters consummatory pattern generation and increases behavioral variability during learning

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Mark A. Rossi

2015-05-01

Full Text Available The role of dopamine in controlling behavior remains poorly understood. In this study we examined licking behavior in an established hyperdopaminergic mouse model—dopamine transporter knockout (DAT KO mice. DAT KO mice showed higher rates of licking, which is due to increased perseveration of licking in a bout. By contrast, they showed increased individual lick durations, and reduced inter-lick-intervals. During extinction, both KO and control mice transiently increased variability in lick pattern generation while reducing licking rate, yet they showed very different behavioral patterns. Control mice gradually increased lick duration as well as variability. By contrast, DAT KO mice exhibited more immediate (within 10 licks adjustments—an immediate increase in lick duration variability, as well as more rapid extinction. These results suggest that the level of dopamine can modulate the persistence and pattern generation of a highly stereotyped consummatory behavior like licking, as well as new learning in response to changes in environmental feedback. Increased dopamine in DAT KO mice not only increased perseveration of bouts and individual lick duration, but also increased the behavioral variability in response to the extinction contingency and the rate of extinction.

High levels of DDT in breast milk: Intake, risk, lactation duration, and involvement of gender

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Bouwman, Hindrik; Kylin, Henrik; Sereda, Barbara; Bornman, Riana

2012-01-01

We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean ΣDDT levels in breast milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest ΣDDT level ever reported for breast milk from South Africa (140 mg/kg mf). Understanding the causes for these differences would be informative for exposure reduction intervention. The Provisional Tolerable Daily Intake (PTDI) for DDT by infants, and the Maximum Residue Limit (MRL) were significantly exceeded. DDT had no effect on duration of lactation. There were indications (not significant) from DDT-sprayed villages that first-born female infants drink milk with more ΣDDT than first-born male infants, and vice versa for multipara male and female infants, suggesting gender involvement on levels of DDT in breast milk – requiring further investigation. - Highlights: ► The highest ΣDDT in breast milk ever found in South Africa is reported. ► Maximum Residue Limit is exceeded, up to 99 times. ► Provisional Tolerable Daily Intake is exceeded, up to 310 times. ► High ΣDDT did not affect duration of lactation. ► Infant gender may affect levels of ΣDDT in breast milk. - High levels of DDT in breast milk from a DDT-spayed area exceeded known limits in milk, but did not affect duration lactation. Infant gender may affect levels of ΣDDT in breast milk.

Temporal organization of rest defined by actigraphy data in healthy and childhood chronic fatigue syndrome children.

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Kawabata, Minako; Ueno, Taro; Tomita, Jun; Kawatani, Junko; Tomoda, Akemi; Kume, Shoen; Kume, Kazuhiko

2013-11-04

Accumulating evidence has shown a universality in the temporal organization of activity and rest among animals ranging from mammals to insects. Previous reports in both humans and mice showed that rest bout durations followed long-tailed (i.e., power-law) distributions, whereas activity bouts followed exponential distributions. We confirmed similar results in the fruit fly, Drosophila melanogaster. Conversely, another report showed that the awakening bout durations, which were defined by polysomnography in bed, followed power-law distributions, while sleeping periods, which may correspond to rest, followed exponential distributions. This apparent discrepancy has been left to be resolved. Actigraphy data from healthy and disordered children were analyzed separately for two periods: time out of bed (UP period) and time in bed (DOWN period). When data over a period of 24 h were analyzed as a whole, rest bouts showed a power law distribution as previously reported. However, when UP and DOWN period data were analyzed separately, neither showed power law properties. Using a newly developed strict method, only 30% of individuals satisfied the power law criteria, even when the 24 h data were analyzed. The human results were in contrast to the Drosophila results, which revealed clear power-law distributions for both day time and night time rest through the use of a strict method. In addition, we analyzed the actigraphy data from patients with childhood type chronic fatigue syndrome (CCFS), and found that they showed differences from healthy controls when their UP and DOWN data were analyzed separately. These results suggested that the DOWN sleep, the bout distribution of which showed exponential properties, contributes to the production of long-tail distributions in human rest periods. We propose that separate analysis of UP and DOWN period data is important for understanding the temporal organization of activity.

Digoxin affects potassium homeostasis during exercise in patients with heart failure.

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Schmidt, T A; Bundgaard, H; Olesen, H L; Secher, N H; Kjeldsen, K

1995-04-01

The aim was to evaluate whether digitalisation of heart failure patients affects extrarenal potassium handling during and following exercise, and to assess digoxin receptor occupancy in human skeletal muscle in vivo. In a paired study of before versus after digitalisation, 10 patients with congestive heart failure underwent identical exercise sessions consisting of three bouts of increasing work rates, 41-93 W, on a cycle ergometer. The final bouts were followed by exercise to exhaustion. The femoral vessels and brachial artery were catheterised. Arterial blood pressure, heart rate, leg blood flow, cardiac output, plasma potassium, haemoglobin, pH, and skeletal muscle receptor occupancy with digoxin in biopsies were determined. Occupancy of skeletal muscle Na/K-ATPase with digoxin was 9% (P digitalisation femoral venous plasma potassium increased by 0.2-0.3 mmol.litre-1 (P digitalisation the femoral venoarterial difference in plasma potassium increased by 50-100% (P digitalisation on plasma potassium were not the outcome of changes in haemodynamics, because cardiac output and leg blood flow increased by up to 13% and 19% (P < 0.05), nor was it the outcome of changes in haemoconcentration or pH. Extrarenal potassium handling is altered as a result of digoxin treatment. This is likely to reflect a reduced capacity of skeletal muscle Na/K-ATPase for active potassium uptake because of inhibition by digoxin, adding to the reduction of skeletal muscle Na/K-ATPase concentration induced by heart failure per se. In heart failure patients, improved haemodynamics induced by digoxin may, however, increase the capacity for physical conditioning. Thus the impairment of extrarenal potassium homeostasis by heart failure and digoxin treatment may be counterbalanced by training.

Effects of methylprednisolone on the duration of rocuronium-induced neuromuscular block

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Geng, Weilian; Nie, Yuyan; Huang, Shaoqiang

2017-01-01

Abstract Background: We aim to investigate whether intraoperative use of methylprednisolone could affect the duration of rocuronium-induced neuromuscular blockade. Methods: A double blind, randomized, placebo-controlled trial was conducted. A total of 136 patients underwent gynecologic laparoscopic surgery were randomly divided into 3 groups: pregroup, receiving intravenous injection of methylprednisolone (40 mg) 30 minutes before induction of anesthesia; postgroup, receiving intravenous injection of methylprednisolone (40 mg) immediately after induction of anesthesia and intubation; and control group, receiving intravenous injection of normal saline. Patients were intravenously administrated with rocuronium 0.6 mg/kg, and changes in adductor policies evoked twitch responses were measured by ulnar nerve stimulator. Results: We found that all patients achieved maximum blockade effects, and there was no difference in onset time among the 2 groups. For time required to achieve train-of-four ratio (TOFR) 90%, pregroup (64.50 ± 10.52 minutes) and postgroup (65.29 ± 11.64 minutes) were significantly shorter than that of the control group (71.04 ± 10.55 minutes, P = .027), whereas clinical duration and total duration were significantly shorter in the 2 groups received methylprednisolone than the control group. However, there was no significant difference between the 2 treatment groups either in clinical duration and total duration of muscle relaxants, or time required to achieve TOFR 90%. No significant difference was found in recovery index among the 3 groups. Conclusion: Our findings suggest that a single intravenous injection of methylprednisolone, no matter preoperatively or intraoperatively, could shorten the duration of rocuronium-induced neuromuscular blockade. PMID:28953616

Effects of transient global ischaemia on freezing behaviour and activity in a context-dependent fear conditioning task--implications for memory investigations.

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Henrich-Noack, Petra; Krautwald, Karla; Reymann, Klaus G; Wetzel, Wolfram

2011-07-15

Transient global ischaemia induces cell death in the CA1 layer of the hippocampus. To evaluate the functional consequences, we performed context-dependent fear conditioning. Ischaemia was induced by 2-vessel-occlusion (2VO) in gerbils. On day 6 post ischaemia or sham procedures (in control group) gerbils were placed in a test chamber and after 3 min adaption time exposed to foot-shocks (training session). On the next day the animals were placed in the same test chamber without foot-shocks (test session). As a parameter for memory performance we used the standard method of measuring the total freezing time via a cumulative time-sampling procedure during the test session. We found a significant longer total freezing time in control animals than in ischaemic animals. In addition, however, we applied a more detailed analysis of (i) quantifying the number of freezing bouts, (ii) the average duration of single freezing bouts, (iii) the activity pattern during the training and test situation and (iv) we differentially evaluated all the single time segments of the experiment. These analyses revealed that although maintenance of freezing (duration of freezing bout) was significantly lower in ischaemic animals compared to controls, the initiation of freezing (number of freezing bouts) was not significantly different between the two groups during the test session. The activity scores of ischaemic and non-ischaemic gerbils were similar during the adaption time of the training session. The foot-shock, however, induced a significantly different pattern of behaviour in the ischaemic animals, which was selectively reproduced during the test session. In conclusion, ischaemic gerbils reacted to a fearsome thread with a behavioural pattern different from unlesioned animals and they revealed this specific foot-shock induced behaviour again during the test session. This indicated that CA1 hippocampal death did not interrupt memory performance but changed expression of fear. Therefore

Curved Walking Rehabilitation with a Rotating Treadmill in Patients with Parkinson’s Disease: A Proof of Concept

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Godi, Marco; Giardini, Marica; Nardone, Antonio; Turcato, Anna Maria; Caligari, Marco; Pisano, Fabrizio; Schieppati, Marco

2017-01-01

Training subjects to step-in-place eyes open on a rotating platform while maintaining a fixed body orientation in space [podokinetic stimulation (PKS)] produces a posteffect consisting in inadvertent turning around while stepping-in-place eyes closed [podokinetic after-rotation (PKAR)]. Since the rationale for rehabilitation of curved walking in Parkinson’s disease is not fully known, we tested the hypothesis that repeated PKS favors the production of curved walking in these patients, who are uneasy with turning, even when straight walking is little affected. Fifteen patients participated in 10 training sessions distributed in 3 weeks. Both counterclockwise and clockwise PKS were randomly administered in each session. PKS velocity and duration were gradually increased over sessions. The velocity and duration of the following PKAR were assessed. All patients showed PKAR, which increased progressively in peak velocity and duration. In addition, before and at the end of the treatment, all patients walked overground along linear and circular trajectories. Post-training, the velocity of walking bouts increased, more so for the circular than the linear trajectory. Cadence was not affected. This study has shown that parkinsonian patients learn to produce turning while stepping when faced with appropriate training and that this capacity translates into improved overground curved walking. PMID:28293213

Word Durations in Non-Native English

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Baker, Rachel E.; Baese-Berk, Melissa; Bonnasse-Gahot, Laurent; Kim, Midam; Van Engen, Kristin J.; Bradlow, Ann R.

2010-01-01

In this study, we compare the effects of English lexical features on word duration for native and non-native English speakers and for non-native speakers with different L1s and a range of L2 experience. We also examine whether non-native word durations lead to judgments of a stronger foreign accent. We measured word durations in English paragraphs read by 12 American English (AE), 20 Korean, and 20 Chinese speakers. We also had AE listeners rate the `accentedness' of these non-native speakers. AE speech had shorter durations, greater within-speaker word duration variance, greater reduction of function words, and less between-speaker variance than non-native speech. However, both AE and non-native speakers showed sensitivity to lexical predictability by reducing second mentions and high frequency words. Non-native speakers with more native-like word durations, greater within-speaker word duration variance, and greater function word reduction were perceived as less accented. Overall, these findings identify word duration as an important and complex feature of foreign-accented English. PMID:21516172

Effects of metric hierarchy and rhyme predictability on word duration in The Cat in the Hat.

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Breen, Mara

2018-05-01

Word durations convey many types of linguistic information, including intrinsic lexical features like length and frequency and contextual features like syntactic and semantic structure. The current study was designed to investigate whether hierarchical metric structure and rhyme predictability account for durational variation over and above other features in productions of a rhyming, metrically-regular children's book: The Cat in the Hat (Dr. Seuss, 1957). One-syllable word durations and inter-onset intervals were modeled as functions of segment number, lexical frequency, word class, syntactic structure, repetition, and font emphasis. Consistent with prior work, factors predicting longer word durations and inter-onset intervals included more phonemes, lower frequency, first mention, alignment with a syntactic boundary, and capitalization. A model parameter corresponding to metric grid height improved model fit of word durations and inter-onset intervals. Specifically, speakers realized five levels of metric hierarchy with inter-onset intervals such that interval duration increased linearly with increased height in the metric hierarchy. Conversely, speakers realized only three levels of metric hierarchy with word duration, demonstrating that they shortened the highly predictable rhyme resolutions. These results further understanding of the factors that affect spoken word duration, and demonstrate the myriad cues that children receive about linguistic structure from nursery rhymes. Copyright © 2018 Elsevier B.V. All rights reserved.

Nitrous oxide-related postoperative nausea and vomiting depends on duration of exposure.

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Peyton, Philip J; Wu, Christine Yx

2014-05-01

Inclusion of nitrous oxide in the gas mixture has been implicated in postoperative nausea and vomiting (PONV) in numerous studies. However, these studies have not examined whether duration of exposure was a significant covariate. This distinction might affect the future place of nitrous oxide in clinical practice. PubMed listed journals reporting trials in which patients randomized to a nitrous oxide or nitrous oxide-free anesthetic for surgery were included, where the incidence of PONV within the first 24 postoperative hours and mean duration of anesthesia was reported. Meta-regression of the log risk ratio for PONV with nitrous oxide (lnRR PONVN2O) versus duration was performed. Twenty-nine studies in 27 articles met the inclusion criteria, randomizing 10,317 patients. There was a significant relationship between lnRR PONVN2O and duration (r = 0.51, P = 0.002). Risk ratio PONV increased 20% per hour of nitrous oxide after 45 min. The number needed to treat to prevent PONV by avoiding nitrous oxide was 128, 23, and 9 where duration was less than 1, 1 to 2, and over 2 h, respectively. The risk ratio for the overall effect of nitrous oxide on PONV was 1.21 (CIs, 1.04-1.40); P = 0.014. This duration-related effect may be via disturbance of methionine and folate metabolism. No clinically significant effect of nitrous oxide on the risk of PONV exists under an hour of exposure. Nitrous oxide-related PONV should not be seen as an impediment to its use in minor or ambulatory surgery.

How does duration of curing affect the radiopacity of dental materials?

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Bejeh Mir, Arash Poorsattar [School of Dentistry, Babol University of Medical Sciences, Babol (Iran, Islamic Republic of); Bejeh Mir, Morvarid Poorsattar [Private Practice of Orthodontics, Montreal (Canada)

2012-06-15

Clinicians commonly encounter cases in which it is difficult to determine whether adjacent radiopacities are normal or pathologic. The ideal radiopacity of composite resin is equal to or higher than that of the same thickness of aluminum. We aimed to investigate the possible effects of different curing times on the post-24-hour radiopacity of composite resins on digital radiographs. One mm thick samples of Filtek P60 and Clearfil resin composites were prepared and cured with three regimens of continuous 400 mW/cm{sup 2} irradiance for 10, 20 and 30 seconds. Along with a 12-step aluminum step wedge, digital radiographs were captured and the radiopacities were transformed to the equivalent aluminum thicknesses. Data were compared by a general linear model and repeated-measures of ANOVA. Overall, the calculated equivalent aluminum thicknesses of composite resins were increased significantly by doubling and tripling the curing times (F(2,8)=8.94, p=0.002). Notably, Bonferroni post-hoc tests confirmed that the radiopacity of the cured Filtek P60 was significantly higher at 30 seconds compared with 10 seconds (p=0.04). Although the higher radiopacity was observed by increasing the time, other comparisons showed no statistical significance (p>0.05). These results supported the hypothesis that the radiopacity of resin composites might be related to the duration of light curing. In addition to the current standards for radiopacity of digital images, defining a standard protocol for curing of dental materials should be considered, and it is suggested that they should be added to the current requirements for dental material.

How does duration of curing affect the radiopacity of dental materials?

International Nuclear Information System (INIS)

Bejeh Mir, Arash Poorsattar; Bejeh Mir, Morvarid Poorsattar

2012-01-01

Clinicians commonly encounter cases in which it is difficult to determine whether adjacent radiopacities are normal or pathologic. The ideal radiopacity of composite resin is equal to or higher than that of the same thickness of aluminum. We aimed to investigate the possible effects of different curing times on the post-24-hour radiopacity of composite resins on digital radiographs. One mm thick samples of Filtek P60 and Clearfil resin composites were prepared and cured with three regimens of continuous 400 mW/cm 2 irradiance for 10, 20 and 30 seconds. Along with a 12-step aluminum step wedge, digital radiographs were captured and the radiopacities were transformed to the equivalent aluminum thicknesses. Data were compared by a general linear model and repeated-measures of ANOVA. Overall, the calculated equivalent aluminum thicknesses of composite resins were increased significantly by doubling and tripling the curing times (F(2,8)=8.94, p=0.002). Notably, Bonferroni post-hoc tests confirmed that the radiopacity of the cured Filtek P60 was significantly higher at 30 seconds compared with 10 seconds (p=0.04). Although the higher radiopacity was observed by increasing the time, other comparisons showed no statistical significance (p>0.05). These results supported the hypothesis that the radiopacity of resin composites might be related to the duration of light curing. In addition to the current standards for radiopacity of digital images, defining a standard protocol for curing of dental materials should be considered, and it is suggested that they should be added to the current requirements for dental material.

The effect of two different swinging methods upon colic and crying durations among the infants

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Gamze Yilmaz

2015-01-01

Full Text Available Context: Swinging "repetitive and rhythmic" movements are helpful because these provide a continuous stimulus. These methods are reported to be effective upon decreasing baby′s pains or cry. Aim: The purpose of this study was to determine the factors of the two different methods (rhythmic rocking of infants in the arm and rhythmic rocking infants on a blanket on crying duration and colic as well as the factors affecting duration of crying with colic. Materials and Methods: A pre-test post-test quasi experimental model was used. Subjects included 72 infants (1-3 months who had colic and their mothers. The infants were healthy and were delivered after full-term gestation. Results: It has been determined that as the duration of application increased (at the end of the second week, the crying duration of babies who were in each of the two groups decreased. Conclusion: It has been found that swinging ( rhythmic rocking the infants on a blanket and in arm, decreased the colic and crying duration of infants.

The confidence-accuracy relationship for eyewitness identification decisions: Effects of exposure duration, retention interval, and divided attention.

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Palmer, Matthew A; Brewer, Neil; Weber, Nathan; Nagesh, Ambika

2013-03-01

Prior research points to a meaningful confidence-accuracy (CA) relationship for positive identification decisions. However, there are theoretical grounds for expecting that different aspects of the CA relationship (calibration, resolution, and over/underconfidence) might be undermined in some circumstances. This research investigated whether the CA relationship for eyewitness identification decisions is affected by three, forensically relevant variables: exposure duration, retention interval, and divided attention at encoding. In Study 1 (N = 986), a field experiment, we examined the effects of exposure duration (5 s vs. 90 s) and retention interval (immediate testing vs. a 1-week delay) on the CA relationship. In Study 2 (N = 502), we examined the effects of attention during encoding on the CA relationship by reanalyzing data from a laboratory experiment in which participants viewed a stimulus video under full or divided attention conditions and then attempted to identify two targets from separate lineups. Across both studies, all three manipulations affected identification accuracy. The central analyses concerned the CA relation for positive identification decisions. For the manipulations of exposure duration and retention interval, overconfidence was greater in the more difficult conditions (shorter exposure; delayed testing) than the easier conditions. Only the exposure duration manipulation influenced resolution (which was better for 5 s than 90 s), and only the retention interval manipulation affected calibration (which was better for immediate testing than delayed testing). In all experimental conditions, accuracy and diagnosticity increased with confidence, particularly at the upper end of the confidence scale. Implications for theory and forensic settings are discussed.

Validation of triaxial accelerometers to measure the lying behaviour of adult domestic horses.

Science.gov (United States)

DuBois, C; Zakrajsek, E; Haley, D B; Merkies, K

2015-01-01

Examining the characteristics of an animal's lying behaviour, such as frequency and duration of lying bouts, has become increasingly relevant for animal welfare research. Triaxial accelerometers have the advantage of being able to continuously monitor an animal's standing and lying behaviour without relying on live observations or video recordings. Multiple models of accelerometers have been validated for use in monitoring dairy cattle; however, no units have been validated for use in equines. This study tested Onset Pendant G data loggers attached to the hind limb of each of two mature Standardbred horses for a period of 5 days. Data loggers were set to record their position every 20 s. Horses were monitored via live observations during the day and by video recordings during the night to compare activity against accelerometer data. All lying events occurred overnight (three to five lying bouts per horse per night). Data collected from the loggers was converted and edited using a macro program to calculate the number of bouts and the length of time each animal spent lying down by hour and by day. A paired t-test showed no significant difference between the video observations and the output from the data loggers (P=0.301). The data loggers did not distinguish standing hipshot from standing square. Predictability, sensitivity, and specificity were all >99%. This study has validated the use of Onset Pendant G data loggers to determine the frequency and duration of standing and lying bouts in adult horses when set to sample and register readings at 20 s intervals.

The Correlation between Daily Lens Wear Duration and Dry Eye Syndrome.

Science.gov (United States)

Lubis, Rodiah Rahmawaty; Gultom, Monica Tumiar Hanna

2018-05-20

To analyze the correlation between the daily lens wear duration and dry eye syndrome. This study was an analytic cross sectional study using consecutive sampling conducted among the students in Economy and Bussiness Faculty and Faculty of Humanities in University of Sumatera Utara aged between 17 to 23 that wore contact lens continously for at least a year and 5 days a week. The symptoms were assessed using Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and interview about their contact lens comfort; eye drops usage, contact lens washing habit, daily circumstances, places to buy contact lens and personal experince in wearing contact lens. The questionnaire was completed by 53 students. All of them were female and wore softlens wearers. The mean duration of daily wear was 8.19 ± 2.20 hours. The most common symptom experienced was dry eye and the least symptom experienced was removing lens. The most frequent symptom experienced was closing eyes and the least frequent symptom experienced was removing lenses. This study used Exact Test as analysis statistic method. The result was p > 0.05 which means there is no correlation between daily lens wear duration and dry eye syndrome. This study showed that dry eye syndrome was not correlated with daily lens wear duration, but affected by many factors such as contact lens, lens care solution, eye drops usage and environment.

Concomitant changes in cross-sectional area and water content in skeletal muscle after resistance exercise

DEFF Research Database (Denmark)

Kristiansen, Maja Sofie; Uhrbrand, Anders; Hansen, Mette

2014-01-01

This study investigated how one bout (1EX) and three bouts (3EX) of strenuous resistance exercise affected the cross-sectional area (CSA) and water content (WC) of the quadriceps muscle and patella tendon (PT), 4 h and 52 h after the last exercise bout. Ten healthy untrained male subjects performed...... was significantly reduced at 52 h (3EX: 14 ± 2%) compared with baseline and (3EX: 13 ± 1%) compared with 4 h. Present data demonstrate that strenuous resistance exercise results in an acute increase in muscle WC and underlines the importance of ensuring sufficient time between the last exercise bout...

Intertextualité et intersémioticité : Les Bouts de bois de Dieu, un roman-cinéma

Directory of Open Access Journals (Sweden)

Serigne SYLLA

2016-05-01

Full Text Available Les Bouts de bois de Dieu, the Sembene Ousmane’s masterpiece, is in constant contact with novels of European or Negro-African literature. Going by the different meanings of the concept of intertextuality, we shall identify these relations. But the author, writer, experienced in cinema techniques, is unable to make a «functional dividing». That’s the reason why the narrative tools of cinematic aesthetic are shown through the novelistic woof. From that moment, and other notion is essential for us: the intersemioticity. Otherwise, the cinema and the novel are an integral part of the set of themes. Some characters, whose behaviours are explained by the psychoanalytic theory of identification, dream of occidental life or give way to the violence consubstantial with the offered films. All things considered, the work, multimodal, rocking between novel and cinema, becomes a novel-cinema.

The Influence of Various Distraction Stimuli on Affective Responses during Recumbent Cycle Ergometry

Directory of Open Access Journals (Sweden)

Paul C. Miller

2016-03-01

Full Text Available (1 Background: Acute bouts of exercise have been associated with affective changes. Exercise supplemented with distraction may divert attention from unpleasant feelings commonly associated with exercise to more pleasant feelings. The purpose of this study was to compare affective responses to exercise with and without distraction. (2 Methods: 25 individuals volunteered for this investigation and completed all three conditions. This study included three 30 min cycle ergometry exercise conditions, a control condition with no stimuli and two test conditions; one supplemented with a self-selected video and the other self-selected music. The Feeling Scale (FS was administered prior to, every 10 min during, immediately following, and 10 min post exercise. (3 Results: These data demonstrate a significant condition effect for FS during exercise. The condition effect was due to FS being greater in the video and distraction conditions. There was no time by condition interaction seen during exercise. (4 Conclusion: These data indicate that distraction may be effective in supporting a more pleasant exercise experience and could potentially increase exercise adherence.

Speaker-specific variability of phoneme durations

CSIR Research Space (South Africa)

Van Heerden, CJ

2007-11-01

Full Text Available The durations of phonemes varies for different speakers. To this end, the correlations between phonemes across different speakers are studied and a novel approach to predict unknown phoneme durations from the values of known phoneme durations for a...

Strategies for improving performance during long duration Olympic events : the example of Olympic distance Triathlon

OpenAIRE

Hausswirth , Christophe; Brisswalter , Jeanick

2008-01-01

International audience; This review focuses on strategic aspects which may affect performance during a long duration Olympic event: the Olympic distance Triathlon. Given the variety of races during Olympic games, Strategic aspects include as well improving technological features as energetical factors affecting the overall triathlon performance.. During the last decade, a lot of studies have attempted to identify factors reducing the metabolic load associated or not with the development of fa...

Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines.

Science.gov (United States)

Stålhandske, Sandra; Lehmann, Philipp; Pruisscher, Peter; Leimar, Olof

2015-12-01

The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

Temperature and duration of heating of sunflower oil affect ruminal biohydrogenation of linoleic acid in vitro

OpenAIRE

Privé , Florence; Combes, Sylvie; Cauquil, Laurent; Farizon, Yves; Enjalbert, Francis; Troegeler-Meynadier, Annabelle

2010-01-01

Sunflower oil heated at 110 or 150°C for 1, 3, or 6 h was incubated with ruminal content in order to investigate the effects of temperature and duration of heating of oil on the ruminal biohydrogenation of linoleic acid in vitro. When increased, these 2 parameters acted together to decrease the disappearance of linoleic acid in the media by inhibiting the isomerization of linoleic acid, which led to a decrease in conjugated linoleic acids and trans-C18:1 production. Nevertheless, trans-10 iso...

The immediate effects of a single bout of aerobic exercise on oral glucose tolerance across the glucose tolerance continuum

DEFF Research Database (Denmark)

Knudsen, Sine H; Karstoft, Kristian; Pedersen, Bente K

2014-01-01

We investigated glucose tolerance and postprandial glucose fluxes immediately after a single bout of aerobic exercise in subjects representing the entire glucose tolerance continuum. Twenty-four men with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes (T2D; age......: 56 ± 1 years; body mass index: 27.8 ± 0.7 kg/m(2), P > 0.05) underwent a 180-min oral glucose tolerance test (OGTT) combined with constant intravenous infusion of [6,6-(2)H2]glucose and ingestion of [U-(13)C]glucose, following 1 h of exercise (50% of peak aerobic power) or rest. In both trials......OGTT, and Rd (all P value in NGT subjects when compared to IGT and T2D subjects. Accordingly, following exercise, the plasma glucose concentration during the OGTT was increased in NGT subjects (P

Toward a definition of affective instability.

Science.gov (United States)

Renaud, Suzane M; Zacchia, Camillo

2012-01-01

Affective instability is a psychophysiological symptom observed in some psychopathologies. It is a complex construct that encompasses (1) primary emotions, or affects, and secondary emotions, with each category having its own characteristics, amplitude, and duration, (2) rapid shifting from neutral or valenced affect to intense affect, and (3) dysfunctional modulation of emotions. Affective instability is often confused with mood lability, as in bipolar disorders, as well as with other terms. To clarify the concept, we searched databases for the term affective instability and read related articles on the topic. In this article we situate the term within the current affective nomenclature and human emotional experience, explore its psychophysiological features, and place it within the context of psychopathology. We explain why the term can potentially be confused with mood pathology and then define affective instability as an inherited temperamental trait modulated by developmental experience.

Synthesizing controllers from duration calculus

DEFF Research Database (Denmark)

Fränzle, Martin

1996-01-01

Duration Calculus is a logic for reasoning about requirements for real-time systems at a high level of abstraction from operational detail, which qualifies it as an interesting starting point for embedded controller design. Such a design activity is generally thought to aim at a control device...... the physical behaviours of which satisfy the requirements formula, i.e. the refinement relation between requirements and implementations is taken to be trajectory inclusion. Due to the abstractness of the vocabulary of Duration Calculus, trajectory inclusion between control requirements and controller designs...... for embedded controller design and exploit this fact for developing an automatic procedure for controller synthesis from specifications formalized in Duration Calculus. As far as we know, this is the first positive result concerning feasibility of automatic synthesis from dense-time Duration Calculus....

Model-checking dense-time Duration Calculus

DEFF Research Database (Denmark)

Fränzle, Martin

2004-01-01

Since the seminal work of Zhou Chaochen, M. R. Hansen, and P. Sestoft on decidability of dense-time Duration Calculus [Zhou, Hansen, Sestoft, 1993] it is well-known that decidable fragments of Duration Calculus can only be obtained through withdrawal of much of the interesting vocabulary...... of this logic. While this was formerly taken as an indication that key-press verification of implementations with respect to elaborate Duration Calculus specifications were also impossible, we show that the model property is well decidable for realistic designs which feature natural constraints...... suitably sparser model classes we obtain model-checking procedures for rich subsets of Duration Calculus. Together with undecidability results also obtained, this sheds light upon the exact borderline between decidability and undecidability of Duration Calculi and related logics....

Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways.

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Justin George

Full Text Available Asian citrus psyllid (Diaphorina citri feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas bacterium that causes the economically devastating citrus greening disease. Sustained phloem ingestion by D. citri on CLas infected plants is required for pathogen acquisition and transmission. Recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more prominent on the abaxial compared with the adaxial side. The composition and thickness of this fibrous ring may have an important role in selection of feeding sites by D. citri based on leaf age and leaf surface, which in turn can affect pathogen acquisition and transmission. We measured feeding behavior using electrical penetration graph (EPG recordings of individual D. citri adults placed on abaxial or adaxial surfaces of young or mature Valencia orange leaves to study the role of the sclerenchymatous ring in modifying D. citri feeding behavior. Feeding sites on the same leaf tissues were then sectioned and examined by epifluorescence microscopy. The duration of phloem ingestion (E2 waveform by psyllids was significantly reduced on mature compared with young leaves, and on abaxial compared with adaxial leaf surfaces. The longest duration of phloem ingestion was observed from psyllids placed on the adaxial side of young leaves that had the least developed sclerenchyma. Bouts of phloem salivation (E1 waveform, however, were significantly longer on mature leaves compared with young leaves. D. citri adults made consecutive phloem feeding attempts (bouts on the abaxial side of mature leaves and those bouts resulted in unsuccessful or shorter periods of phloem ingestion. Adults also made more frequent and longer bouts of xylem ingestion on mature leaves compared with adult psyllids placed on young leaves. Epifluorescence microscopy showed that the fibrous ring

Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways

Science.gov (United States)

George, Justin; Ammar, El-Desouky; Hall, David G.

2017-01-01

Asian citrus psyllid (Diaphorina citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Sustained phloem ingestion by D. citri on CLas infected plants is required for pathogen acquisition and transmission. Recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more prominent on the abaxial compared with the adaxial side. The composition and thickness of this fibrous ring may have an important role in selection of feeding sites by D. citri based on leaf age and leaf surface, which in turn can affect pathogen acquisition and transmission. We measured feeding behavior using electrical penetration graph (EPG) recordings of individual D. citri adults placed on abaxial or adaxial surfaces of young or mature Valencia orange leaves to study the role of the sclerenchymatous ring in modifying D. citri feeding behavior. Feeding sites on the same leaf tissues were then sectioned and examined by epifluorescence microscopy. The duration of phloem ingestion (E2 waveform) by psyllids was significantly reduced on mature compared with young leaves, and on abaxial compared with adaxial leaf surfaces. The longest duration of phloem ingestion was observed from psyllids placed on the adaxial side of young leaves that had the least developed sclerenchyma. Bouts of phloem salivation (E1 waveform), however, were significantly longer on mature leaves compared with young leaves. D. citri adults made consecutive phloem feeding attempts (bouts) on the abaxial side of mature leaves and those bouts resulted in unsuccessful or shorter periods of phloem ingestion. Adults also made more frequent and longer bouts of xylem ingestion on mature leaves compared with adult psyllids placed on young leaves. Epifluorescence microscopy showed that the fibrous ring in young

Effects of Ripening Duration and Rosemary Powder Addition on Salchichon Modified Sausage Quality

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Jong-Hyun Jung

2015-05-01

Full Text Available The ripening durations and ingredients for the Salchichon sausages were modified to increase pork rear leg consumption by Korean consumers. The salchichon, a ripened pork sausage, was produced to evaluate the efficacy of two different ripening durations with and without rosemary powder on salchichon sausage quality, and the treatments were: i 45 days of ripening without rosemary, ii 60 days of ripening without rosemary, iii 45 days of ripening with 0.05% rosemary, and iv 60 days of ripening with 0.05% rosemary. Significant differences were observed in both moisture and fat content for ripening durations, with the highest moisture and least fat content observed in salchichon modified sausage (SMS ripened for 45 days. Ripening duration and rosemary addition appeared to influence water activity (aw of salchichon sausages. The aw of SMS ripened for 45 days was 0.80, whereas the other had aw values <0.80. Lactic acid bacteria were predominant, as Korean traditional fermented red pepper paste was added to sausages; however, the Bacillus cereus population was significantly affected by rosemary powder addition. Chewiness and gumminess decreased significantly due to the addition of rosemary powder compared to SMS without rosemary powder, and both 45 days of ripening and rosemary powder addition influenced the hardness of SMS. In conclusion, ripening duration of SMS for 45 days in the presence of rosemary powder provided superior SMS quality with an economical ripening duration compared to that of ripening with rosemary powder or ripening for 60 days.

The Duration of Paid Parental Leave and Children's Scholastic Performance

OpenAIRE

Liu, Qian; Nordström Skans, Oskar

2009-01-01

We study how the duration of paid parental leave affects the accumulation of cognitive skills among children. We use a reform which extended parental leave benefits from 12 to 15 months for Swedish children born after August 1988 to evaluate the effects of prolonged parental leave on children's test scores and grades at age 16. We show that, on average, the reform had no effect on children's scholastic performance. However, we do find positive effects for children of well-educated mothers, a ...

Determinants of long-duration commuting and long-duration commuters' perceptions and attitudes toward commuting time: Evidence from Kunming, China

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Mingwei He

2017-04-01

Full Text Available Understanding the commuting patterns of long-duration commuters and the possible changes in these patterns can help policymakers adopt the more reasonable land use and transportation policies. With Kunming in China as a case study, the determinants of long-duration commuting trips were identified based on logistic regression model. The results indicated that age, education level, number of workers, presence of retirees, and residential location have a significant impact on the occurrence of long-duration commuting trips. The ideal commuting times and tolerance thresholds of commuting time of long-duration commuters were also investigated. The statistical results revealed the distributions of ideal commuting times and tolerance thresholds of commuting time of both short- and long-duration commuters. The average tolerance threshold of commuting time and the average ideal commuting time of long-duration commuters were greater than those of short-duration commuters. For 97.2% of the long-duration commuters, their actual commuting time was longer than the ideal commuting time; this finding indicates that most long-duration commuters are dissatisfied with their commuting time. The actual commuting time of 40.1% long-duration commuters exceeded their tolerance thresholds; these commuters are eager to reduce their commuting time.

Energy expenditure of interruptions to sedentary behavior

Directory of Open Access Journals (Sweden)

Strath Scott J

2011-06-01

Full Text Available Abstract Background Advances in technology, social influences and environmental attributes have resulted in substan-tial portions of the day spent in sedentary pursuits. Sedentary behavior may be a cause of many chronic diseases including obesity, insulin resistance, type 2 diabetes and the metabolic syndrome. Research demonstrated that breaking up sedentary time was beneficially associated with markers of body composition, cardiovascular health and type 2 diabetes. Therefore, the purpose of this study was to quantify the total energy expenditure of three different durations of physical activity within a 30-minute sedentary period and to examine the potential benefits of interrupting sedentary behavior with physical activity for weight control. Methods Participants completed four consecutive 30-minute bouts of sedentary behavior (reading, working on the computer, or doing other desk activities with and without interruptions of walking at a self-selected pace. Bout one contained no walking interruptions. Bout two contained a 1-minute walking period. Bout three contained a 2-minute walking period. Bout four contained a 5-minute walking period. Body composition and resting metabolic rate were assessed. Result Twenty males and females (18-39 years completed this study. Results of the repeated measures analysis of variance with post-hoc testing showed that significantly more energy was expended during each 30 minute sedentary bout with a walking break than in the 30 minute sedentary bout (p Conclusions This study demonstrated that making small changes, such as taking a five minute walking break every hour could yield beneficial weight control or weight loss results. Therefore, taking breaks from sedentary time is a potential outlet to prevent obesity and the rise of obesity in developed countries.

Duration of orthognathic-surgical treatment.

Science.gov (United States)

Paunonen, Jaakko; Helminen, Mika; Peltomäki, Timo

2017-07-01

The objective of this study was to determine the duration of orthognathic-surgical treatment conducted with conventional pre- and post-surgical orthodontic treatment phases. The study material was comprised of the files of 185 consecutive patients treated in Oral and Maxillofacial Unit, Tampere University Hospital, Finland, in 2007-2014. The files were reviewed and the following data was obtained: gender and age of patients, ICD-10 diagnosis, type of malocclusion, duration of pre- and post-surgical orthodontic treatment and type of operation. Total treatment duration (median) from placement of separating rings for banding until fixed orthodontic appliances were removed and retention period started was 31.1 months, of which pre-surgical orthodontics took 24.4 months and postsurgical 6.4 months. Treatment duration (median) was in BSSO was 32.1, LeFort 1 30.1 and bimaxillary osteotomy 29.7 months. Orthodontic extractions were performed in 35 patients (19%). If the orthodontic treatment included tooth extraction, the duration of pre-surgical treatment was on average 10 months longer, which is a statistically highly significant difference (p pre-surgical orthodontic treatment prolong treatment time by an average of 8-9 months.

From Sleep Duration to Childhood Obesity

DEFF Research Database (Denmark)

Börnhorst, Claudia; Hense, Sabrina; Ahrens, Wolfgang

2012-01-01

Sleep duration has been identified as risk factor for obesity already in children. Besides investigating the role of fat mass (FM), this study addressed the question whether endocrine mechanisms act as intermediates in the association between sleep duration and overweight/obesity. Within...... the framework of the IDEFICS study, the present research was conducted in 609 German resident children aged 2–9 years with information on fasting insulin, C-reactive protein and cortisol levels next to anthropometric measurements and parental questionnaires. Emphasising methodological aspects, an age......-specific measure of sleep duration was derived to account for alteration in sleep duration during childhood/period of growth. Multivariate linear regression and quantile regression models confirmed an inverse relationship between sleep duration and measures of overweight/obesity. The estimate for the association...

Factors That Influence Running Intensity in Interchange Players in Professional Rugby League.

Science.gov (United States)

Delaney, Jace A; Thornton, Heidi R; Duthie, Grant M; Dascombe, Ben J

2016-11-01

Rugby league coaches adopt replacement strategies for their interchange players to maximize running intensity; however, it is important to understand the factors that may influence match performance. To assess the independent factors affecting running intensity sustained by interchange players during professional rugby league. Global positioning system (GPS) data were collected from all interchanged players (starters and nonstarters) in a professional rugby league squad across 24 matches of a National Rugby League season. A multilevel mixed-model approach was employed to establish the effect of various technical (attacking and defensive involvements), temporal (bout duration, time in possession, etc), and situational (season phase, recovery cycle, etc) factors on the relative distance covered and average metabolic power (P met ) during competition. Significant effects were standardized using correlation coefficients, and the likelihood of the effect was described using magnitude-based inferences. Superior intermittent running ability resulted in very likely large increases in both relative distance and P met . As the length of a bout increased, both measures of running intensity exhibited a small decrease. There were at least likely small increases in running intensity for matches played after short recovery cycles and against strong opposition. During a bout, the number of collision-based involvements increased running intensity, whereas time in possession and ball time out of play decreased demands. These data demonstrate a complex interaction of individual- and match-based factors that require consideration when developing interchange strategies, and the manipulation of training loads during shorter recovery periods and against stronger opponents may be beneficial.

Lateral head turning affects temporal memory.

Science.gov (United States)

Vicario, Carmelo Mario; Martino, Davide; Pavone, Enea Francesco; Fuggetta, Giorgio

2011-08-01

Spatial attention is a key factor in the exploration and processing of the surrounding environment, and plays a role in linking magnitudes such as space, time, and numbers. The present work evaluates whether shifting the coordinates of spatial attention through rotational head movements may affect the ability to estimate the duration of different time intervals. A computer-based implicit timing task was employed, in which participants were asked to concentrate and report verbally on colour changes of sequential stimuli displayed on a computer screen; subsequently, they were required to reproduce the temporal duration (ranging between 5 and 80 sec.) of the perceived stimuli using the computer keyboard. There was statistically significant overestimation of the 80-sec. intervals exclusively on the rightward rotation head posture, whereas head posture did not affect timing performances on shorter intervals. These findings support the hypothesis that the coordinates of spatial attention influence the ability to process time, consistent with the existence of common cortical metrics of space and time in healthy humans.

Effect of prior warm-up duration on the time limit at peak speed in untrained men.

Science.gov (United States)

da Cruz, Victor H; Peserico, Cecília S; Machado, Fabiana A

2017-10-01

The peak speed (Vpeak) and its time limit (tlim) are variables used to prescribe training loads and the intervals durations during interval training, respectively. The aim of this study was to test different warm-up durations (5, 10 and 15 minutes), adapted from the protocol proposed by Billat et al.,1 to determine tlim in untrained men. Fifteen untrained men were submitted to the following laboratory evaluations: 1) an incremental running exercise test on a treadmill starting with a speed of 8 km/h, after a warm-up of walking at 6 km/h for three minutes, and increased by 1 km/h between each successive 3-minute stage until volitional exhaustion to determine Vpeak; 2) three rectangular tests, performed in randomized order, with warm-up durations of 5, 10, and 15 minutes at 60% of Vpeak to determine the tlim5, tlim10, and tlim15; after the warm-up the tests were performed at the speed of the individual Vpeak until volitional exhaustion. It was demonstrated that the duration of the warm-up affected the test duration (tlim). Significant differences were observed between tlim5 and tlim15, and between tlim10 and tlim15. However, tlim15 and tlim10 did not differ. Additionally, duration of the warm-up did not influence other variables (HRmax, RPEmax and post lactate concentrations). Therefore, it was concluded that the duration of the warm-up in tlim tests modifies the test duration in untrained men.

Shorter sleep duration is associated with social impairment and comorbidities in ASD.

Science.gov (United States)

Veatch, Olivia J; Sutcliffe, James S; Warren, Zachary E; Keenan, Brendan T; Potter, Melissa H; Malow, Beth A

2017-07-01

Sleep disturbance, particularly insomnia, is common in children with autism spectrum disorders (ASD). Furthermore, disturbed sleep affects core symptoms and other related comorbidities. Understanding the causes and consequences of sleep disturbances in children with ASD is an important step toward mitigating these symptoms. To better understand the connection between sleep duration and ASD severity, we analyzed ASD-related symptoms using the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS), IQ scores, and parent reports of the average amount of time slept per night that were available in the medical histories of 2,714 children with ASD in the Simons Simplex Collection (SSC). The mean (SD) sleep duration was 555 minutes. Sleep duration and severity of core ASD symptoms were negatively correlated, and sleep duration and IQ scores were positively correlated. Regression results indicated that more severe social impairment, primarily a failure to develop peer relationships, is the core symptom most strongly associated with short sleep duration. Furthermore, increased severity for numerous maladaptive behaviors assessed on the Child Behavior Checklist, as well as reports of attention deficit disorder, depressive disorder, and obsessive compulsive disorder were associated with short sleep duration. Severity scores for social/communication impairment and restricted and repetitive behaviors (RRB) were increased, and IQ scores were decreased, for children reported to sleep ≤420 minutes per night (lower 5th percentile) compared to children sleeping ≥660 minutes (upper 95th percentile). Our results indicate that reduced amounts of sleep are related to more severe symptoms in children with ASD. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1221-1238. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism

Access to Awareness for Faces during Continuous Flash Suppression Is Not Modulated by Affective Knowledge.

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Milena Rabovsky

Full Text Available It is a controversially debated topic whether stimuli can be analyzed up to the semantic level when they are suppressed from visual awareness during continuous flash suppression (CFS. Here, we investigated whether affective knowledge, i.e., affective biographical information about faces, influences the time it takes for initially invisible faces with neutral expressions to overcome suppression and break into consciousness. To test this, we used negative, positive, and neutral famous faces as well as initially unfamiliar faces, which were associated with negative, positive or neutral biographical information. Affective knowledge influenced ratings of facial expressions, corroborating recent evidence and indicating the success of our affective learning paradigm. Furthermore, we replicated shorter suppression durations for upright than for inverted faces, demonstrating the suitability of our CFS paradigm. However, affective biographical information did not modulate suppression durations for newly learned faces, and even though suppression durations for famous faces were influenced by affective knowledge, these effects did not differ between upright and inverted faces, indicating that they might have been due to low-level visual differences. Thus, we did not obtain unequivocal evidence for genuine influences of affective biographical information on access to visual awareness for faces during CFS.

Incorporating Duration Information in Activity Recognition

Science.gov (United States)

Chaurasia, Priyanka; Scotney, Bryan; McClean, Sally; Zhang, Shuai; Nugent, Chris

Activity recognition has become a key issue in smart home environments. The problem involves learning high level activities from low level sensor data. Activity recognition can depend on several variables; one such variable is duration of engagement with sensorised items or duration of intervals between sensor activations that can provide useful information about personal behaviour. In this paper a probabilistic learning algorithm is proposed that incorporates episode, time and duration information to determine inhabitant identity and the activity being undertaken from low level sensor data. Our results verify that incorporating duration information consistently improves the accuracy.

The Effects of "Mere Exposure" on Learning and Affect.

Science.gov (United States)

Stang, David J.

The mediating role of learning in the relationship between repeated exposure and affect was explored and supported in three experiments involving a total of 229 undergraduate participants. It was found that both learning and affect measures behaved in essentially the same way as a function of exposure duration (experiments I and III), serial…

Sleep duration and subjective psychological well-being in adolescence: a longitudinal study in Switzerland and Norway

OpenAIRE

Brand, Serge; Lemola,Sakari; Holsboer-Trachsler,Edith; Grob,Alexander; Kalak,Nadeem

2014-01-01

Nadeem Kalak,1 Sakari Lemola,2 Serge Brand,1,3 Edith Holsboer–Trachsler,1 Alexander Grob21Center for Affective, Stress and Sleep Disorder, Psychiatric Hospital of the University of Basel, Center for Affective, Stress and Sleep Disorders, Basel, Switzerland; 2Department of Psychology, 3Department of Sport and Health Science, Division of Sport Science, University of Basel, Basel, Switzerland Background: Adolescents’ sleep duration and subjective psychological well-being are...

Physical activity patterns of people affected by depressive and anxiety disorders as measured by accelerometers: a cross-sectional study.

Directory of Open Access Journals (Sweden)

Björg Helgadóttir

Full Text Available Exercise can relieve both depressive and anxiety disorders and it is therefore of importance to establish movement patterns of mildly to moderately affected sufferers to estimate the treatment potential. The aim is to describe the physical activity patterns of people affected by mild to moderate depressive and/or anxiety symptoms using objective measures of physical activity.The design of the study was cross-sectional using data from 165 people aged 18-65 years, with mild to moderate depressive and/or anxiety disorder symptoms (scoring ≥ 10 on the PHQ-9. Diagnoses were made using Mini International Neuropsychiatric Interview (MINI and symptom severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS. The participants wore accelerometers for a week to evaluate physical activity patterns.No statistically significant differences were detected between different diagnoses, though depressed participants tended to be less active and more sedentary. Only one-fifth of the sample followed public health guidelines regarding physical activity. Each one point increase in MADRS was associated with a 2.4 minute reduction in light physical activity, independent of moderate-to-vigorous physical activity and sedentary time. MADRS was positively associated with number of sedentary bouts.The physical activity pattern of people with depressive and/or anxiety disorders was characterized by large amounts of sedentary time and low fulfillment of physical activity guidelines. There is therefore a large treatment potential for this group by increasing exercise. The results suggest that instead of focusing exclusively on high intensity exercise for treating depressive and anxiety disorders, health care providers might encourage patients to reduce sedentary time by increasing light physical activity and decreasing the number of sedentary bouts, though further studies are needed that can determine directionality.

Physical activity patterns of people affected by depressive and anxiety disorders as measured by accelerometers: a cross-sectional study.

Science.gov (United States)

Helgadóttir, Björg; Forsell, Yvonne; Ekblom, Örjan

2015-01-01

Exercise can relieve both depressive and anxiety disorders and it is therefore of importance to establish movement patterns of mildly to moderately affected sufferers to estimate the treatment potential. The aim is to describe the physical activity patterns of people affected by mild to moderate depressive and/or anxiety symptoms using objective measures of physical activity. The design of the study was cross-sectional using data from 165 people aged 18-65 years, with mild to moderate depressive and/or anxiety disorder symptoms (scoring ≥ 10 on the PHQ-9). Diagnoses were made using Mini International Neuropsychiatric Interview (MINI) and symptom severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). The participants wore accelerometers for a week to evaluate physical activity patterns. No statistically significant differences were detected between different diagnoses, though depressed participants tended to be less active and more sedentary. Only one-fifth of the sample followed public health guidelines regarding physical activity. Each one point increase in MADRS was associated with a 2.4 minute reduction in light physical activity, independent of moderate-to-vigorous physical activity and sedentary time. MADRS was positively associated with number of sedentary bouts. The physical activity pattern of people with depressive and/or anxiety disorders was characterized by large amounts of sedentary time and low fulfillment of physical activity guidelines. There is therefore a large treatment potential for this group by increasing exercise. The results suggest that instead of focusing exclusively on high intensity exercise for treating depressive and anxiety disorders, health care providers might encourage patients to reduce sedentary time by increasing light physical activity and decreasing the number of sedentary bouts, though further studies are needed that can determine directionality.

Flexibility in the duration of parental care: Female leopards prioritise cub survival over reproductive output.

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Balme, Guy A; Robinson, Hugh S; Pitman, Ross T; Hunter, Luke T B

2017-09-01

Deciding when to terminate care of offspring is a key consideration for parents. Prolonging care may increase fitness of current offspring, but it can also reduce opportunities for future reproduction. Despite its evolutionary importance, few studies have explored the optimal duration of parental care, particularly among large carnivores. We used a 40-year dataset to assess the trade-offs associated with the length of maternal care in leopards in the Sabi Sand Game Reserve, South Africa. We compared the costs imposed by care on the survival and residual reproductive value of leopard mothers against the benefits derived from maternal care in terms of increased offspring survival, recruitment and reproduction. We also examined the demographic and ecological factors affecting the duration of care in the light of five explanatory hypotheses: litter size, sex allocation, resource limitation, timing of independence and terminal investment. Duration of care exhibited by female leopards varied markedly, from 9 to 35 months. Mothers did not appear to suffer any short- or long-term survival costs from caring for cubs, but extending care reduced the number of litters that mothers could produce during their lifetimes. Interestingly, the duration of care did not appear to affect the post-independence survival or reproductive success of offspring (although it may have indirectly affected offspring survival by influencing dispersal distance). However, results from generalised linear mixed models showed that mothers prolonged care during periods of prey scarcity, supporting the resource limitation hypothesis. Female leopards also cared for sons longer than daughters, in line with the sex-allocation hypothesis. Cub survival is an important determinant of the lifetime reproductive success in leopards. By buffering offspring against environmental perturbation without jeopardising their own survivorship, female leopards apparently "hedge their bets" with current offspring rather than

The algorithm for duration acceleration of repetitive projects considering the learning effect

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Chen, Hongtao; Wang, Keke; Du, Yang; Wang, Liwan

2018-03-01

Repetitive project optimization problem is common in project scheduling. Repetitive Scheduling Method (RSM) has many irreplaceable advantages in the field of repetitive projects. As the same or similar work is repeated, the proficiency of workers will be correspondingly low to high, and workers will gain experience and improve the efficiency of operations. This is learning effect. Learning effect is one of the important factors affecting the optimization results in repetitive project scheduling. This paper analyzes the influence of the learning effect on the controlling path in RSM from two aspects: one is that the learning effect changes the controlling path, the other is that the learning effect doesn't change the controlling path. This paper proposes corresponding methods to accelerate duration for different types of critical activities and proposes the algorithm for duration acceleration based on the learning effect in RSM. And the paper chooses graphical method to identity activities' types and considers the impacts of the learning effect on duration. The method meets the requirement of duration while ensuring the lowest acceleration cost. A concrete bridge construction project is given to verify the effectiveness of the method. The results of this study will help project managers understand the impacts of the learning effect on repetitive projects, and use the learning effect to optimize project scheduling.

Estimation of Kubo number and correlation length of fluctuating magnetic fields and pressure in BOUT + + edge pedestal collapse simulation

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Kim, Jaewook; Lee, W.-J.; Jhang, Hogun; Kaang, H. H.; Ghim, Y.-C.

2017-10-01

Stochastic magnetic fields are thought to be as one of the possible mechanisms for anomalous transport of density, momentum and heat across the magnetic field lines. Kubo number and Chirikov parameter are quantifications of the stochasticity, and previous studies show that perpendicular transport strongly depends on the magnetic Kubo number (MKN). If MKN is smaller than one, diffusion process will follow Rechester-Rosenbluth model; whereas if it is larger than one, percolation theory dominates the diffusion process. Thus, estimation of Kubo number plays an important role to understand diffusion process caused by stochastic magnetic fields. However, spatially localized experimental measurement of fluctuating magnetic fields in a tokamak is difficult, and we attempt to estimate MKNs using BOUT + + simulation data with pedestal collapse. In addition, we calculate correlation length of fluctuating pressures and Chirikov parameters to investigate variation correlation lengths in the simulation. We, then, discuss how one may experimentally estimate MKNs.

Influence of prior knowledge of exercise duration on pacing strategies during game-based activities.

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Gabbett, Tim J; Walker, Ben; Walker, Shane

2015-04-01

To investigate the influence of prior knowledge of exercise duration on the pacing strategies employed during game-based activities. Twelve semiprofessional team-sport athletes (mean ± SD age 22.8 ± 2.1 y) participated in this study. Players performed 3 small-sided games in random order. In one condition (Control), players were informed that they would play the small-sided game for 12 min and then completed the 12-min game. In a 2nd condition (Deception), players were told that they would play the small-sided game for 6 minutes, but after completing the 6-min game, they were asked to complete another 6 min. In a 3rd condition (Unknown), players were not told how long they would be required to play the small-sided game, but the activity was terminated after 12 min. Movement was recorded using a GPS unit sampling at 10 Hz. Post hoc inspection of video footage was undertaken to count the number of possessions and the number and quality of disposals. Higher initial intensities were observed in the Deception (130.6 ± 3.3 m/min) and Unknown (129.3 ± 2.4 m/min) conditions than the Control condition (123.3 ± 3.4 m/min). Greater amounts of high-speed running occurred during the initial phases of the Deception condition, and more low-speed activity occurred during the Unknown condition. A moderately greater number of total skill involvements occurred in the Unknown condition than the Control condition. These findings suggest that during game-based activities, players alter their pacing strategy based on the anticipated endpoint of the exercise bout.

Duration of surgical-orthodontic treatment.

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Häll, Birgitta; Jämsä, Tapio; Soukka, Tero; Peltomäki, Timo

2008-10-01

To study the duration of surgical-orthodontic treatment with special reference to patients' age and the type of tooth movements, i.e. extraction vs. non-extraction and intrusion before or extrusion after surgery to level the curve of Spee. The material consisted files of 37 consecutive surgical-orthodontic patients. The files were reviewed and gender, diagnosis, type of malocclusion, age at the initiation of treatment, duration of treatment, type of tooth movements (extraction vs. non-extraction and levelling of the curve of Spee before or after operation) and type of operation were retrieved. For statistical analyses two sample t-test, Kruskal-Wallis and Spearman rank correlation tests were used. Mean treatment duration of the sample was 26.8 months, of which pre-surgical orthodontics took on average 17.5 months. Patients with extractions as part of the treatment had statistically and clinically significantly longer treatment duration, on average 8 months, than those without extractions. No other studied variable seemed to have an impact on the treatment time. The present small sample size prevents reliable conclusions to be made. However, the findings suggest, and patients should be informed, that extractions included in the treatment plan increase chances of longer duration of surgical-orthodontic treatment.

Seasonal Patterns of Community Participation and Mobility of Wheelchair Users Over an Entire Year.

Science.gov (United States)

Borisoff, Jaimie F; Ripat, Jacquie; Chan, Franco

2018-03-23

To describe how people who use wheelchairs participate and move at home and in the community over an entire yearlong period, including during times of inclement weather conditions. Longitudinal mixed-methods research study. Urban community in Canada. People who use a wheelchair for home and community mobility (N=11). Not applicable. Use of a global positioning system (GPS) tracker for movement in community (number of trips per day), use of accelerometer for bouts of wheeling mobility (number of bouts per day, speed, distance, and duration), prompted recall interviews to identify supports and barriers to mobility and participation. More trips per day were taken during the summer (P= .03) and on days with no snow and temperatures above 0°C. Participants reliant on public transportation demonstrated more weather-specific changes in their trip patterns. The number of daily bouts of mobility remained similar across seasons; total daily distance wheeled, duration, and speed were higher on summer days, days with no snow, and days with temperatures above 0°C. A higher proportion of outdoor wheeling bouts occurred in summer (P=.02) and with temperatures above 0°C (P=.03). Inaccessible public environments were the primary barrier to community mobility and participation; access to social supports and private transportation were the primary supports. Objective support is provided for the influence of various seasonal weather conditions on community mobility and participation for people who use a wheelchair. Longitudinal data collection provided a detailed understanding of the patterns of, and influences on, wheelchair mobility and participation within wheelchair users' own homes and communities. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effect of a prenatal nutritional intervention program on initiation and duration of breastfeeding.

Science.gov (United States)

Léger-Leblanc, Gisèle; Rioux, France M

2008-01-01

To evaluate initiation and duration of breastfeeding of infants born to mothers who participated in the Early Childhood Initiative (ECI) program. Factors affecting the initiation and the early cessation of breastfeeding were also explored. Twenty-five pregnant women participating in the ECI program completed this prospective study. At 36 weeks' gestation, a questionnaire was administered to assess socioeconomic status, intention to breastfeed and breastfeeding experience. When the infants were three and six months of age, feeding practices were assessed with a questionnaire. The breastfeeding initiation rate was 62.5%. At one and three months postpartum, exclusive breastfeeding rates were 39% and 4%, respectively. At six months, none of the women was exclusively breastfeeding. Primiparity, prenatal classes, having been breastfed and intention to breastfeed at 36 weeks' gestation were positively associated with breastfeeding initiation. Father's education, intention to breastfeed at 36 weeks' gestation, no water or formula given to the infant during hospitalization and higher maternal hemoglobin level at 36 weeks' gestation were positively associated with the duration of breastfeeding. The rate of initiation and duration of breastfeeding for ECI participants were low. To achieve successful interventions, it is important to target modifiable factors known to influence the initiation and duration of breastfeeding within this population.

Molecular transduction mechanisms in ACTH-induced grooming

NARCIS (Netherlands)

Gispen, W.H.; Colbern, D.; Spruijt, B.M.

1988-01-01

Intraventricular administration of ACTH1-24 induces excessive grooming in the rat. Ethogram analysis shows that the peptide does not alter grooming behavior seen in a novel box, but that it prolongs the duration of the grooming bout. Extensive structure-activity studies have been performed which

The effect of an acute bout of rubber tube running constraint on kinematics and muscle activity.

Science.gov (United States)

Haudum, Anita; Birklbauer, Jürgen; Müller, Erich

2012-01-01

We examined the effect of an acute bout of treadmill running with rubber tube (RT) and without rubber tube (NT) elastic constraints on electromyographic (EMG), 3D kinematics variability, and blood lactate concentration (LA). In the RT test, the constraints were attached to the hips and ankles. The selected variables were compared between 30 min of NT running and 30 minutes of RT running in 13 healthy recreationally trained male runners who had no prior exposure to RT. Statistical analysis revealed significantly higher EMG variability (p running influences muscle recruitment and variability, but has only a minor influence on kinematics. Changes in LA were significant, although relatively small. The observed adaptations in EMG and kinematics suggest that the RTs provide a possibility to create within movement variability in various sports, and thus, variable training conditions may foster strategies to increase the ability to flexibly adapt to different and new situations. Key pointsAdaptation to training device occurred quite rapidly.Changes in muscle activity were more pronounced than kinematic changes due to the training device.Training device may be used to increase within-movement variability.Participants may learn to flexibly adapt to variable constraints.

Effect of post-hatch transportation duration and parental age on broiler chicken quality, welfare, and productivity.

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Jacobs, Leonie; Delezie, Evelyne; Duchateau, Luc; Goethals, Klara; Ampe, Bart; Lambrecht, Evelien; Gellynck, Xavier; Tuyttens, Frank A M

2016-09-01

Broiler chicks are transported to production sites within one to 2 d post-hatch. Possible effects of this transportation are poorly understood and could vary among chicks from breeder flocks of different ages. The aim of the present study was to investigate the effects of transportation duration and parental flock age on chick welfare, productivity, and quality. After hatch in a commercial hatchery, 1,620 mixed-sex chicks from 29-wk old (young) and 1,620 chicks from 60-wk old (old) breeders were subjected to transportation of 1.5 h or 11 h duration. After transportation, 2,800 chicks were divided among 100 pens, with each pen containing 28 chicks from one transportation crate (2 or 3 pens per crate). From the remaining chicks, on average 6 chicks (min 4, max 8) per crate (n = 228) were randomly selected and assessed for chick quality, weighed, and culled for yolk sac weighing (one d). Chicks that had not been assigned to pens or were not used for post-transportation measurements, were removed from the experiment (n = 212). Mortality, ADG, BW, and feed conversion ( FC: ) of the experimental chicks were recorded until 41 d. Meat quality was measured for breast fillets (n = 47). No interaction effect of parental age and transportation duration was found for any variables. BW and yolk sac weight at one d were lower for chicks transported 11 h than 1.5 h and for chicks from young versus old breeders. The effect of parental flock age on BW persisted until slaughter. Additionally, parental age positively affected ADG until slaughter. Chick quality was lower in chicks from old versus young breeders. Chick quality and productivity were not affected by transportation duration. Mortality and meat quality were not affected by either parental age or transportation duration. To conclude, no long-term detrimental effects were found from long post-hatch transportation in chicks from young or old parent flocks. Based on these results, we suggest that 11 h post

Cryostorage duration does not affect pregnancy and neonatal outcomes: a retrospective single-centre cohort study of vitrified-warmed blastocysts.

Science.gov (United States)

Ueno, Satoshi; Uchiyama, Kazuo; Kuroda, Tomoko; Yabuuchi, Akiko; Ezoe, Kenji; Okimura, Tadashi; Okuno, Takashi; Kobayashi, Tamotsu; Kato, Keiichi

2018-06-01

A retrospective cohort study of 8736 autologous single vitrified-warmed blastocyst transfer cycles was conducted in a single centre to investigate the effect of cryostorage on clinical and neonatal outcomes. Cryostorage duration was classified into three groups: (A) 0-2 months (n = 4702); (B) 2-13 months (n = 2853) and (C) 13-97 months (n = 1181). Blastocysts were vitrified using the Cryotop method. No significant differences were observed in live birth rates: (A) 37.3%; (B) 34.9%; (C) (35.2%). Gestational period was significantly shorter in group C: (A) 38.7 ± 1.8; (B) 38.6 ± 1.6; (C) 38.1 ± 1.7; P limitation of this study was that maximum storage duration was 8 years; most blastocysts were in cryostorage for much shorter periods. Long-term storage of blastocysts that are vitrified using an open device vitrification system has no negative effect on pregnancy and neonatal outcomes. Copyright © 2018 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

A designated centre for people with disabilities operated by Enable Ireland Disability Services Limited, Tipperary

LENUS (Irish Health Repository)

Harrington, Deirdre M.

2011-10-28

Abstract Background Adolescent females have been highlighted as a particularly sedentary population and the possible negative effects of a sedentary lifestyle are being uncovered. However, much of the past sedentary research is based on self-report or uses indirect methods to quantity sedentary time. Total time spent sedentary and the possible intricate sedentary patterns of adolescent females have not been described using objective and direct measure of body inclination. The objectives of this article are to examine the sedentary levels and patterns of a group of adolescent females using the ActivPAL™ and to highlight possible differences in sedentary levels and patterns across the week and within the school day. A full methodological description of how the data was analyzed is also presented. Methods One hundred and eleven adolescent females, age 15-18 yrs, were recruited from urban and rural areas in the Republic of Ireland. Participants wore an ActivPAL physical activity monitor for a 7.5 day period. The ActivPAL directly reports total time spent sitting\\/lying every 15 seconds and accumulation (frequency and duration) of sedentary activity was examined using a customized MATLAB ® computer software programme. Results While no significant difference was found in the total time spent sitting\\/lying over the full 24 hour day between weekday and weekend day (18.8 vs. 18.9 hours; p = .911), significantly more sedentary bouts of 1 to 5 minutes and 21 to 40 minutes in duration were accumulated on weekdays compared to weekend days (p < .001). The mean length of each sedentary bout was also longer (9.8 vs. 8.8 minutes; p < .001). When school hours (9 am-3 pm) and after school hours (4 pm-10 pm) were compared, there was no difference in total time spent sedentary (3.9 hours; p = .796) but the pattern of accumulation of the sedentary time differed. There were a greater number of bouts of > 20 minutes duration during school hours than after school hours (4.7 vs. 3

Cross-Sectional Analysis of Levels and Patterns of Objectively Measured Sedentary Time in Adolescent Females

LENUS (Irish Health Repository)

Harrington, Deirdre M.

2011-10-28

Abstract Background Adolescent females have been highlighted as a particularly sedentary population and the possible negative effects of a sedentary lifestyle are being uncovered. However, much of the past sedentary research is based on self-report or uses indirect methods to quantity sedentary time. Total time spent sedentary and the possible intricate sedentary patterns of adolescent females have not been described using objective and direct measure of body inclination. The objectives of this article are to examine the sedentary levels and patterns of a group of adolescent females using the ActivPAL™ and to highlight possible differences in sedentary levels and patterns across the week and within the school day. A full methodological description of how the data was analyzed is also presented. Methods One hundred and eleven adolescent females, age 15-18 yrs, were recruited from urban and rural areas in the Republic of Ireland. Participants wore an ActivPAL physical activity monitor for a 7.5 day period. The ActivPAL directly reports total time spent sitting\\/lying every 15 seconds and accumulation (frequency and duration) of sedentary activity was examined using a customized MATLAB ® computer software programme. Results While no significant difference was found in the total time spent sitting\\/lying over the full 24 hour day between weekday and weekend day (18.8 vs. 18.9 hours; p = .911), significantly more sedentary bouts of 1 to 5 minutes and 21 to 40 minutes in duration were accumulated on weekdays compared to weekend days (p < .001). The mean length of each sedentary bout was also longer (9.8 vs. 8.8 minutes; p < .001). When school hours (9 am-3 pm) and after school hours (4 pm-10 pm) were compared, there was no difference in total time spent sedentary (3.9 hours; p = .796) but the pattern of accumulation of the sedentary time differed. There were a greater number of bouts of > 20 minutes duration during school hours than after school hours (4.7 vs. 3

A designated centre for people with disabilities operated by Brothers of Charity Services Galway, Galway

LENUS (Irish Health Repository)

Harrington, Deirdre M.

2011-10-28

Abstract Background Adolescent females have been highlighted as a particularly sedentary population and the possible negative effects of a sedentary lifestyle are being uncovered. However, much of the past sedentary research is based on self-report or uses indirect methods to quantity sedentary time. Total time spent sedentary and the possible intricate sedentary patterns of adolescent females have not been described using objective and direct measure of body inclination. The objectives of this article are to examine the sedentary levels and patterns of a group of adolescent females using the ActivPAL™ and to highlight possible differences in sedentary levels and patterns across the week and within the school day. A full methodological description of how the data was analyzed is also presented. Methods One hundred and eleven adolescent females, age 15-18 yrs, were recruited from urban and rural areas in the Republic of Ireland. Participants wore an ActivPAL physical activity monitor for a 7.5 day period. The ActivPAL directly reports total time spent sitting\\/lying every 15 seconds and accumulation (frequency and duration) of sedentary activity was examined using a customized MATLAB ® computer software programme. Results While no significant difference was found in the total time spent sitting\\/lying over the full 24 hour day between weekday and weekend day (18.8 vs. 18.9 hours; p = .911), significantly more sedentary bouts of 1 to 5 minutes and 21 to 40 minutes in duration were accumulated on weekdays compared to weekend days (p < .001). The mean length of each sedentary bout was also longer (9.8 vs. 8.8 minutes; p < .001). When school hours (9 am-3 pm) and after school hours (4 pm-10 pm) were compared, there was no difference in total time spent sedentary (3.9 hours; p = .796) but the pattern of accumulation of the sedentary time differed. There were a greater number of bouts of > 20 minutes duration during school hours than after school hours (4.7 vs. 3

The influence of storage duration on the setting time of type 1 alginate impression material

Science.gov (United States)

Rahmadina, A.; Triaminingsih, S.; Irawan, B.

2017-08-01

Alginate is one of the most commonly used dental impression materials; however, its setting time is subject to change depending on storage conditions and duration. This creates problems because consumer carelessness can affect alginate shelf life and quality. In the present study, the setting times of two groups of type I alginate with different expiry dates was tested. The first group consisted of 11 alginate specimens that had not yet passed the expiry date, and the second group consisted of alginates that had passed the expiry date. The alginate powder was mixed with distilled water, poured into a metal ring, and tested with a polished rod of poly-methyl methacrylate. Statistical analysis showed a significant difference (p<0.05) between the setting times of the alginate that had not passed the expiry date (157 ± 3 seconds) and alginate that had passed the expiry date (144 ± 2 seconds). These findings indicate that storage duration can affect alginate setting time.

Workplace Social Support and Behavioral Health Prior to Long-Duration Spaceflight.

Science.gov (United States)

Deming, Charlene A; Vasterling, Jennifer J

2017-06-01

Preparation and training for long-duration spaceflight bring with them psychosocial stressors potentially affecting the well-being and performance of astronauts, before and during spaceflight. Social support from within the workplace may mitigate behavioral health concerns arising during the preflight period and enhance resiliency before and during extended missions. The purpose of this review was to evaluate evidence addressing the viability of workplace social support as a pre-mission countermeasure, specifically addressing: 1) the observed relationships between workplace social support and behavioral health; 2) perceived need, acceptability, and format preference for workplace social support among high-achievers; 3) potential barriers to delivery/receipt of workplace social support; 4) workplace social support interventions; and 5) delivery timeframe and anticipated duration of workplace social support countermeasure benefits. We conducted an evidence review examining workplace social support in professional contexts sharing one or more characteristics with astronauts and spaceflight. Terms included populations of interest, social support constructs, and behavioral health outcomes. Abstracts of matches were subsequently reviewed for relevance and quality. Research findings demonstrate clear associations between workplace social support and behavioral health, especially following exposure to stress. Further, studies indicate strong need for support and acceptability of support countermeasures, despite barriers. Our review revealed two general formats for providing support (i.e., direct provision of support and training to optimize skills in provision and receipt of support) with potential differentiation of expected duration of benefits, according to format. Workplace social support countermeasures hold promise for effective application during pre-mission phases of long-duration spaceflight. Specific recommendations are provided.Deming CA, Vasterling JJ

Obstructive sleep apnea alters sleep stage transition dynamics.

Directory of Open Access Journals (Sweden)

Matt T Bianchi

2010-06-01

Full Text Available Enhanced characterization of sleep architecture, compared with routine polysomnographic metrics such as stage percentages and sleep efficiency, may improve the predictive phenotyping of fragmented sleep. One approach involves using stage transition analysis to characterize sleep continuity.We analyzed hypnograms from Sleep Heart Health Study (SHHS participants using the following stage designations: wake after sleep onset (WASO, non-rapid eye movement (NREM sleep, and REM sleep. We show that individual patient hypnograms contain insufficient number of bouts to adequately describe the transition kinetics, necessitating pooling of data. We compared a control group of individuals free of medications, obstructive sleep apnea (OSA, medical co-morbidities, or sleepiness (n = 374 with mild (n = 496 or severe OSA (n = 338. WASO, REM sleep, and NREM sleep bout durations exhibited multi-exponential temporal dynamics. The presence of OSA accelerated the "decay" rate of NREM and REM sleep bouts, resulting in instability manifesting as shorter bouts and increased number of stage transitions. For WASO bouts, previously attributed to a power law process, a multi-exponential decay described the data well. Simulations demonstrated that a multi-exponential process can mimic a power law distribution.OSA alters sleep architecture dynamics by decreasing the temporal stability of NREM and REM sleep bouts. Multi-exponential fitting is superior to routine mono-exponential fitting, and may thus provide improved predictive metrics of sleep continuity. However, because a single night of sleep contains insufficient transitions to characterize these dynamics, extended monitoring of sleep, probably at home, would be necessary for individualized clinical application.

Effects of Excerpt Tempo and Duration on Musicians' Ratings of High-Level Piano Performances

Science.gov (United States)

Wapnick, Joel; Ryan, Charlene; Campbell, Louise; Deek, Patricia; Lemire, Renata; Darrow, Alice-Ann

2005-01-01

The purpose of this study was to determine how judgments of solo performances recorded at an international piano competition might be affected by excerpt duration (20 versus 60 seconds) and tempo (slow versus fast). Musicians rated performances on six test items. Results indicated that piano majors rated slow excerpts higher than they rated fast…

C'mon get happy: reduced magnitude and duration of response during a positive-affect induction in depression.

Science.gov (United States)

Horner, Michelle S; Siegle, Greg J; Schwartz, Robert M; Price, Rebecca B; Haggerty, Agnes E; Collier, Amanda; Friedman, Edward S

2014-11-01

Depression involves decreased positive affect. Whether this is due to a failure to achieve or maintain positive emotion in response to discrete stimuli is unclear. Understanding the nature of decreased positive affect could help to address how to intervene in the phenomenon, for example, how to structure interventions using positive and rewarding stimuli in depression. Thus, we examined the time course of affect following exposure to positive stimuli in depressed and healthy individuals. Seventy-one adults with major depressive disorder and thirty-four never-depressed controls read a self-generated highly positive script and continuously rated their affect for 7 min. Both groups quickly achieved increased positive affect, however, compared to controls, depressed participants did not achieve the same level of positive affect, did not maintain their positive affect, spent less time rating their affect as happy, and demonstrated larger drops in mood. These data indicate that depressed and nondepressed individuals can generate positive reactions to happy scripts, but depressed individuals cannot achieve or sustain equivalent levels of positive affect. Interventions for depression might fruitfully focus on increasing depressed individuals' ability to maintain initial engagement with positive stimuli over a sustained period of time. © 2014 Wiley Periodicals, Inc.

Mitochondrial Haplogroups Modify the Effect of Diabetes Duration and HbA1c on Proliferative Diabetic Retinopathy Risk in Patients With Type 2 Diabetes.

Science.gov (United States)

Mitchell, Sabrina L; Neininger, Abigail C; Bruce, Carleigh N; Chocron, Isaac M; Bregman, Jana A; Estopinal, Christopher B; Muhammad, Ayesha; Umfress, Allison C; Jarrell, Kelli L; Warden, Cassandra; Harlow, Paula A; Wellons, Melissa; Samuels, David C; Brantley, Milam A

2017-12-01

We previously demonstrated an association between European mitochondrial haplogroups and proliferative diabetic retinopathy (PDR). The purpose of this study was to determine how the relationship between these haplogroups and both diabetes duration and hyperglycemia, two major risk factors for diabetic retinopathy (DR), affect PDR prevalence. Our population consisted of patients with type 2 diabetes with (n = 377) and without (n = 480) DR. A Kruskal-Wallis test was used to compare diabetes duration and hemoglobin A1c (HbA1c) among mitochondrial haplogroups. Logistic regressions were performed to investigate diabetes duration and HbA1c as risk factors for PDR in the context of European mitochondrial haplogroups. Neither diabetes duration nor HbA1c differed among mitochondrial haplogroups. Among DR patients from haplogroup H, longer diabetes duration and increasing HbA1c were significant risk factors for PDR (P = 0.0001 and P = 0.011, respectively). Neither diabetes duration nor HbA1c was a significant risk factor for PDR in DR patients from haplogroup UK. European mitochondrial haplogroups modify the effects of diabetes duration and HbA1c on PDR risk in patients with type 2 diabetes. In our patient population, longer diabetes duration and higher HbA1c increased PDR risk in patients from haplogroup H, but did not affect PDR risk in patients from haplogroup UK. This relationship has not been previously demonstrated and may explain, in part, why some patients with nonproliferative DR develop PDR and others do not, despite similar diabetes duration and glycemic control.

Effect of freezing method and frozen storage duration on instrumental quality of lamb throughout display.

Science.gov (United States)

Muela, E; Sañudo, C; Campo, M M; Medel, I; Beltrán, J A

2010-04-01

This study evaluated the effect of freezing method (FM) (air blast freezer, freezing tunnel, or nitrogen chamber) and frozen storage duration (FSD) (1, 3, or 6 months) on the instrumental measurements of quality of thawed lamb, aged for a total of 72 h, throughout a 10-d display period, compared to the quality of fresh meat. pH, colour, lipid oxidation, thawing, and cooking losses in Longissimus thoracis and lumborum muscle, were determined following standard methods. FM affected yellowness, FSD redness and thawing losses, and both affected oxidation (increased as freezing rate decreased and/or as storage duration increased). When compared with fresh meat, the main differences appeared on oxidation (where a significant interaction between treatment (3FM x 3FSD + fresh meat) with display duration was detected), and on total losses (thaw + cook losses). Oxidation was lower in fresh meat, but values were not significantly different from those stored frozen for 1 month. Fresh meat had smaller total losses than did thawed meat, but losses were not significantly different from meat frozen in the freezing tunnel and stored frozen for 1 month. Display duration had a greater effect on instrumental quality parameters than did FM or FSD. pH, b*, and oxidation increased, and L* and a* decreased with an increase in the number of days on display. In conclusion, neither freezing method nor frozen storage up to 6 months influenced extensively the properties of lamb when instrumental measurements of quality were measured in meat that had been displayed for 1d after thawing. The small deterioration shown in this study should not give consumers concerns about frozen meat. 2009 Elsevier Ltd. All rights reserved.

Insomnia with objective short sleep duration is associated with longer duration of insomnia in the Freiburg Insomnia Cohort compared to insomnia with normal sleep duration, but not with hypertension.

Science.gov (United States)

Johann, Anna F; Hertenstein, Elisabeth; Kyle, Simon D; Baglioni, Chiara; Feige, Bernd; Nissen, Christoph; McGinness, Alastair J; Riemann, Dieter; Spiegelhalder, Kai

2017-01-01

To replicate the association between insomnia with objective short sleep duration and hypertension, type 2 diabetes and duration of insomnia. Retrospective case-control study. Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg. 328 patients with primary insomnia classified according to DSM-IV criteria (125 males, 203 females, 44.3 ± 12.2 years). N/A. All participants were investigated using polysomnography, blood pressure measurements, and fasting routine laboratory. Insomnia patients with short sleep duration (insomnia compared to those with normal sleep duration (≥ 6 hours) in the first night of laboratory sleep. Insomnia patients who were categorised as short sleepers in either night were not more likely to suffer from hypertension (systolic blood pressure of ≥ 140 mm Hg, diastolic blood pressure of ≥ 90 mm Hg, or a previously established diagnosis). Data analysis showed that insomnia patients with objective short sleep duration were not more likely to suffer from type 2 diabetes (fasting plasma glucose level of ≥ 126 mg/dl, or a previously established diagnosis). However, the diabetes analysis was only based on a very small number of diabetes cases. As a new finding, insomnia patients who were categorised as short sleepers in either night presented with increases in liver enzyme levels. The finding on insomnia duration supports the concept of two distinct sub-groups of insomnia, namely insomnia with, and without, objectively determined short sleep duration. However, our data challenges previous findings that insomnia patients with short sleep duration are more likely to suffer from hypertension.

Elaborative rehearsal of nontemporal information interferes with temporal processing of durations in the range of seconds but not milliseconds.

Science.gov (United States)

Rammsayer, Thomas; Ulrich, Rolf

2011-05-01

The distinct timing hypothesis suggests a sensory mechanism for processing of durations in the range of milliseconds and a cognitively controlled mechanism for processing of longer durations. To test this hypothesis, we employed a dual-task approach to investigate the effects of maintenance and elaborative rehearsal on temporal processing of brief and long durations. Unlike mere maintenance rehearsal, elaborative rehearsal as a secondary task involved transfer of information from working to long-term memory and elaboration of information to enhance storage in long-term memory. Duration discrimination of brief intervals was not affected by a secondary cognitive task that required either maintenance or elaborative rehearsal. Concurrent elaborative rehearsal, however, impaired discrimination of longer durations as compared to maintenance rehearsal and a control condition with no secondary task. These findings endorse the distinct timing hypothesis and are in line with the notion that executive functions, such as continuous memory updating and active transfer of information into long-term memory interfere with temporal processing of durations in the second, but not in the millisecond range. 2011 Elsevier B.V. All rights reserved.

Nerve conduction and antioxidant levels in experimentally diabetic rats: effects of streptozotocin dose and diabetes duration

NARCIS (Netherlands)

Gispen, W.H.; Dam, P.S. van; Asbeck, B.S. van; Bravenboer, B.; Oirschot, J.F.L.M. van; Marx, J.J.

1999-01-01

Oxidative stress supposedly plays a role in the pathogenesis of diabetic neuropathy. We have studied whether a variation in the streptozotocin (STZ) dose or diabetes duration affects the outcome of measurements of oxidative damage in relation to nerve conduction. In experiment 1, we induced diabetes

THE INFLUENCE OF POTASSIUM DICHROMATE Cr (VI ADMINISTRATION DURATION ON GLOBULAR RESISTANCE IN FEMALE RATS

Directory of Open Access Journals (Sweden)

LETIŢIA STANA

2009-05-01

Full Text Available The „in vivo” experiment has had as aim the study of different Cr(VI doses administration on globular resistance in female rats related to administration duration. Study was carried out on 56 female rats divided in 8 groups, 6 experimental and 2 control that received potassium dichromate in drinking water in doses of 25 ppm, 50 ppm and 75ppm Cr(VI, for 3 months, respectively, 6 months. Decrease of globular resistance (in terms of haemolysis degree in hypotonic solutions at increasing dose (up to 0.8% NaCl at 75 ppm dose in all experimental groups, in direct relation with the duration of administration was registered. Control groups were in physiological limits. The results of the present study revealed the affecting of erythrocyte membrane in function of administration duration and chromium intake level, because of oxidative lesions produced by it.

KrF laser ablation of a polyethersulfone film: Effect of pulse duration on structure formation

International Nuclear Information System (INIS)

Pazokian, Hedieh; Selimis, Alexandros; Stratakis, Emmanuel; Mollabashi, Mahmoud; Barzin, Jalal; Jelvani, Saeid

2011-01-01

Polyethersulfone (PES) films were processed with KrF laser irradiation of different pulse durations (τ). Scanning electron microscopy (SEM) and Raman spectroscopy were employed for the examination of the morphology and chemical composition of the irradiated surfaces, respectively. During ablation with 500 fs and 5 ps pulses, localized deformations (beads), micro-ripple and conical structures were observed on the surface depending on the irradiation fluence (F) and the number of pulses (N). In addition, the number density of the structures is affected by the irradiation parameters (τ, F, N). Furthermore, at longer pulse durations (τ = 30 ns), conical structures appear at lower laser fluence values, which are converted into columnar structures upon irradiation at higher fluences. The Raman spectra collected from the top of the structures following irradiation at different pulse durations revealed graphitization of the ns laser treated areas, in contrast to those processed with ultra-short laser pulses.

Subjective duration distortions mirror neural repetition suppression.

Science.gov (United States)

Pariyadath, Vani; Eagleman, David M

2012-01-01

Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression. Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli) followed by a line presented at a different orientation (oddball stimulus). We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials. Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

Subjective duration distortions mirror neural repetition suppression.

Directory of Open Access Journals (Sweden)

Vani Pariyadath

Full Text Available Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression.Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli followed by a line presented at a different orientation (oddball stimulus. We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials.Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

Developing Project Duration Models in Software Engineering

Institute of Scientific and Technical Information of China (English)

Pierre Bourque; Serge Oligny; Alain Abran; Bertrand Fournier

2007-01-01

Based on the empirical analysis of data contained in the International Software Benchmarking Standards Group(ISBSG) repository, this paper presents software engineering project duration models based on project effort. Duration models are built for the entire dataset and for subsets of projects developed for personal computer, mid-range and mainframeplatforms. Duration models are also constructed for projects requiring fewer than 400 person-hours of effort and for projectsre quiring more than 400 person-hours of effort. The usefulness of adding the maximum number of assigned resources as asecond independent variable to explain duration is also analyzed. The opportunity to build duration models directly fromproject functional size in function points is investigated as well.

Factors affecting the duration of nestling period and fledging order in Tengmalm's owl (Aegolius funereus: effect of wing length and hatching sequence.

Directory of Open Access Journals (Sweden)

Marek Kouba

Full Text Available In altricial birds, the nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mostly been undertaken on passerine birds. We studied individual duration of nestling period of 98 Tengmalm's owl chicks (Aegolius funereus at 27 nests during five breeding seasons using a camera and chip system and radio-telemetry. We found the nestlings stayed in the nest box for 27 - 38 days from hatching (mean ± SD, 32.4 ± 2.2 days. The individual duration of nestling period was negatively related to wing length, but no formally significant effect was found for body weight, sex, prey availability and/or weather conditions. The fledging sequence of individual nestlings was primarily related to hatching order; no relationship with wing length and/or other factors was found in this case. We suggest the length of wing is the most important measure of body condition and individual quality in Tengmalm's owl young determining the duration of the nestling period. Other differences from passerines (e.g., the lack of effect of weather or prey availability on nestling period are considered likely to be due to different life-history traits, in particular different food habits and nesting sites and greater risk of nest predation among passerines.

Contraceptive Use Affects Overall Olfactory Performance: Investigation of Estradiol Dosage and Duration of Intake.

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Kathrin Kollndorfer

Full Text Available The influence of female sex steroids on cognitive performance and sensory perception has been investigated for decades. However, previous research that studied olfaction revealed inconsistent results. The main aim of this study was to investigate the effects of different ethinyl estradiol (EE concentrations of oral contraceptives and duration of intake on olfactory function. Forty-two healthy women, with regular intake of either high or low EE dosage over at least one year and up to 15 years participated in this study. Results revealed a significant concordance between a priori categorization in the two groups with high and low EE dosage and data-driven hierarchical clustering (p = 0.008. Furthermore, significantly higher olfactory performance was observed in women using low-dose products compared to women using high-dosed products (p = 0.019. These findings indicate different effects of pill use with regard to EE concentration. We therefore strongly recommend the acquisition of information about EE dosage of oral contraceptives to reduce potential confounding factors when investigating sensory systems.

Duration Adaptation Occurs Across the Sub- and Supra-Second Systems.

Science.gov (United States)

Shima, Shuhei; Murai, Yuki; Hashimoto, Yuki; Yotsumoto, Yuko

2016-01-01

After repetitive exposure to a stimulus of relatively short duration, a subsequent stimulus of long duration is perceived as being even longer, and after repetitive exposure to a stimulus of relatively long duration, a subsequent stimulus of short duration is perceived as being even shorter. This phenomenon is called duration adaptation, and has been reported only for sub-second durations. We examined whether duration adaptation also occurs for supra-second durations (Experiment 1) and whether duration adaptation occurs across sub- and supra-second durations (Experiment 2). Duration adaptation occurred not only for sub-second durations, but also for supra-second durations and across sub- and supra-second durations. These results suggest that duration adaptation involves an interval-independent system or two functionally related systems that are associated with both the sub- and supra-second durations.

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces pendant le soudage et aux

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces

Satellite-Based Sunshine Duration for Europe

Directory of Open Access Journals (Sweden)

Bodo Ahrens

2013-06-01

Full Text Available In this study, two different methods were applied to derive daily and monthly sunshine duration based on high-resolution satellite products provided by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring using data from Meteosat Second Generation (MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager. The satellite products were either hourly cloud type or hourly surface incoming direct radiation. The satellite sunshine duration estimates were not found to be significantly different using the native 15-minute temporal resolution of SEVIRI. The satellite-based sunshine duration products give additional spatial information over the European continent compared with equivalent in situ-based products. An evaluation of the satellite sunshine duration by product intercomparison and against station measurements was carried out to determine their accuracy. The satellite data were found to be within ±1 h/day compared to high-quality Baseline Surface Radiation Network or surface synoptic observations (SYNOP station measurements. The satellite-based products differ more over the oceans than over land, mainly because of the treatment of fractional clouds in the cloud type-based sunshine duration product. This paper presents the methods used to derive the satellite sunshine duration products and the performance of the different retrievals. The main benefits and disadvantages compared to station-based products are also discussed.

Addictive drugs and their duration affecting on trace elements levels in men

International Nuclear Information System (INIS)

Nadeem, A.; Iqbal, K.; Shafiq, T.; Rehman, S.

2008-01-01

During the drug addiction the blood biochemistry particularly level of trace elements in blood is widely affected. Eighty male addicts of various age groups along with seventeen normal subjects were studied. The plasma Zinc and manganese concentration was high in addict person as compared to normal subjects. Where as a significant decrease in iron concentration was observed in addicts. The plasma copper concentration was also low in addicts as compared to normal subjects. In conclusion drug addiction leads to many biochemical changes that may have detritus effects on health status of addicts. (author)

A single bout of whole-leg, peristaltic pulse external pneumatic compression upregulates PGC-1α mRNA and endothelial nitric oxide sythase protein in human skeletal muscle tissue.

Science.gov (United States)

Kephart, Wesley C; Mobley, C Brooks; Fox, Carlton D; Pascoe, David D; Sefton, JoEllen M; Wilson, Trent J; Goodlett, Michael D; Kavazis, Andreas N; Roberts, Michael D; Martin, Jeffrey S

2015-07-01

What is the central question of this study? Does 60 min of peristaltic pulse external pneumatic compression (EPC) alter gene and protein expression patterns related to metabolism, vascular biology, redox balance and inflammation in vastus lateralis biopsy samples? What is the main finding and its importance? A single bout of EPC transiently upregulates PGC-1α mRNA, while also upregulating endothelial nitric oxide synthase protein and nitric oxide metabolite concentrations in vastus lateralis biopsy samples. We investigated whether a single 60 min bout of whole-leg, lower pressure external pneumatic compression (EPC) altered select vascular, metabolic, antioxidant and inflammation-related mRNAs. Ten participants (eight male, two female; aged 22.0 ± 0.4 years) reported to the laboratory 4 h postprandial, and vastus lateralis muscle biopsies were obtained before (PRE) and 1 and 4 h after EPC treatment. Messenger RNA expression was analysed using real-time RT-PCR, and significant mRNA findings were investigated further by Western blot analysis of respective protein concentrations. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) mRNA increased by 77% 1 h following EPC compared with PRE levels (P = 0.005), but no change in protein concentration 1 or 4 h post-EPC was observed. Increases in endothelial nitric oxide sythase (eNOS) mRNA (+44%) and superoxide dismutase 2 (SOD2) mRNA (+57%) 1 h post-EPC as well as an increase in interleukin-10 mRNA (+132%) 4 h post-EPC compared with PRE levels were observed, but only approached significance (P = 0.076, 0.077 and 0.074, respectively). Interestingly, eNOS protein (+40%, P = 0.025) and nitrate and nitrite (NOx) concentrations (+69%, P = 0.025) increased 1-4 h post-EPC. Moreover, SOD2 protein tended to increase from PRE to 4 h post-EPC (+43%, P = 0.074), although no changes in tissue 4-hydroxnonenal levels was observed. An acute bout of EPC transiently upregulates PGC-1α mRNA, while also upregulating e

A randomized trial comparing structured and lifestyle goals in an internet-mediated walking program for people with type 2 diabetes.

Science.gov (United States)

Richardson, Caroline R; Mehari, Kathleen S; McIntyre, Laura G; Janney, Adrienne W; Fortlage, Laurie A; Sen, Ananda; Strecher, Victor J; Piette, John D

2007-11-16

The majority of individuals with type 2 diabetes do not exercise regularly. Pedometer-based walking interventions can help; however, pedometer-based interventions targeting only total daily accumulated steps might not yield the same health benefits as physical activity programs specifying a minimum duration and intensity of physical activity bouts. This pilot randomized trial compared two goal-setting strategies: 1) lifestyle goals targeting total daily accumulated step counts and 2) structured goals targeting bout steps defined as walking that lasts for 10 minutes or longer at a pace of at least 60 steps per minute. We sought to determine which goal-setting strategy was more effective at increasing bout steps. Participants were sedentary adults with type 2 diabetes. All participants: wore enhanced pedometers with embedded USB ports; uploaded detailed, time-stamped step-count data to a website called Stepping Up to Health; and received automated step-count feedback, automatically calculated goals, and tailored motivational messages throughout the six-week intervention. Only the automated goal calculations and step-count feedback differed between the two groups. The primary outcome of interest was increase in steps taken during the previously defined bouts of walking (lasting at least 10 minutes or longer at a pace of at least 60 steps per minute) between baseline and end of the intervention. Thirty-five participants were randomized and 30 (86%) completed the pilot study. Both groups significantly increased bout steps, but there was no statistically significant difference between groups. Among study completers, bout steps increased by 1921 +/- 2729 steps a day. Those who received lifestyle goals were more satisfied with the intervention (p = 0.006) and wore the pedometer more often (p day of additional moderate intensity bout activity. Pedometer-based walking programs that emphasize total accumulated step counts are more acceptable to participants and are as

Chronic and acute inspiratory muscle loading augment the effect of a 6-week interval program on tolerance of high-intensity intermittent bouts of running.

Science.gov (United States)

Tong, Tom K; Fu, Frank H; Eston, Roger; Chung, Pak-Kwong; Quach, Binh; Lu, Kui

2010-11-01

This study examined the hypothesis that chronic (training) and acute (warm-up) loaded ventilatory activities applied to the inspiratory muscles (IM) in an integrated manner would augment the training volume of an interval running program. This in turn would result in additional improvement in the maximum performance of the Yo-Yo intermittent recovery test in comparison with interval training alone. Eighteen male nonprofessional athletes were allocated to either an inspiratory muscle loading (IML) group or control group. Both groups participated in a 6-week interval running program consisting of 3-4 workouts (1-3 sets of various repetitions of selected distance [100-2,400 m] per workout) per week. For the IML group, 4-week IM training (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets·d-1, 6 d·wk-1) was applied before the interval program. Specific IM warm-up (2 sets of 30 inspiratory efforts at 40% P0) was performed before each workout of the program. For the control group, neither IML was applied. In comparison with the control group, the interval training volume as indicated by the repeatability of running bouts at high intensity was approximately 27% greater in the IML group. Greater increase in the maximum performance of the Yo-Yo test (control: 16.9 ± 5.5%; IML: 30.7 ± 4.7% baseline value) was also observed after training. The enhanced exercise performance was partly attributable to the greater reductions in the sensation of breathlessness and whole-body metabolic stress during the Yo-Yo test. These findings show that the combination of chronic and acute IML into a high-intensity interval running program is a beneficial training strategy for enhancing the tolerance to high-intensity intermittent bouts of running.

Self-reported sleep duration and daytime napping are associated with renal hyperfiltration in general population.

Science.gov (United States)

Lin, Miao; Su, Qing; Wen, Junping; Wei, Shichao; Yao, Jin; Huang, Huibin; Liang, Jixing; Li, Liantao; Lin, Wei; Lin, Lixiang; Lu, Jieli; Bi, Yufang; Wang, Weiqing; Ning, Guang; Chen, Gang

2018-03-01

Renal hyperfiltration (RHF) has emerged as a novel marker of early renal damage in various conditions such as diabetes and metabolic syndrome. Aberrant sleep duration and excessive daytime napping may affect the development of chronic kidney disease (CKD). In this study, the association between sleep duration, daytime napping, and renal hyperfiltration was assessed. This study was conducted in three communities in China. A total of 16,119 community volunteers (5735 males and 10,384 females) aged 40-65 years without CKD were included for the study. Participants with short sleep duration (naps longer than 1.5 h per day had a higher risk of renal hyperfiltration compared with those without napping (OR 1.400, 95% CI 1.018-1.924). Further joint analysis indicated that participants with long sleep duration (≥10 h/day) had a more than twofold increased risk of RHF regardless of nap status compared with those who slept 8-9 h per day without daytime napping. The association between sleep duration or daytime napping and RHF could not be explained by the influence of sleep quality. Additional subgroup analysis showed long sleep duration (≥9 h/day) and long daytime napping (≥1.5 h) were associated with an increased risk of RHF among individuals with good sleep quality. Sleep duration less than 6 h/day or more than 10 h/day and long daytime napping tend to be associated with an increased risk of renal hyperfiltration in middle-aged general population, and this relationship was independent of diabetes, hypertension, obesity, or poor sleep quality.

Stress reactivity to and recovery from a standardised exercise bout: a study of 31 runners practising relaxation techniques.

Science.gov (United States)

Solberg, E E; Ingjer, F; Holen, A; Sundgot-Borgen, J; Nilsson, S; Holme, I

2000-08-01

To compare the efficacy in runners of two relaxation techniques with regard to exercise reactivity and recovery after exercise. Thirty one adult male runners were studied prospectively for six months in three groups practising either meditation (n = 11) or autogenic training (n = 11) or serving as controls (n = 10). Before and after the six months relaxation intervention, indicators of reactivity to exercise and metabolism after exercise (blood lactate concentration, heart rate (HR), and oxygen consumption (VO2)), were tested immediately after and 10 minutes after exercise. Resting HR was also assessed weekly at home during the trial. State anxiety was measured before and after the intervention. After the relaxation training, blood lactate concentration after exercise was significantly (pmeditation group compared with the control group. No difference was observed in lactate responses between the autogenic training group and the control group. There were no significant differences among the groups with regard to HR, VO2, or levels of anxiety. Meditation training may reduce the lactate response to a standardised exercise bout.

RFI flagging implications for short-duration transients

Science.gov (United States)

Cendes, Y.; Prasad, P.; Rowlinson, A.; Wijers, R. A. M. J.; Swinbank, J. D.; Law, C. J.; van der Horst, A. J.; Carbone, D.; Broderick, J. W.; Staley, T. D.; Stewart, A. J.; Huizinga, F.; Molenaar, G.; Alexov, A.; Bell, M. E.; Coenen, T.; Corbel, S.; Eislöffel, J.; Fender, R.; Grießmeier, J.-M.; Jonker, P.; Kramer, M.; Kuniyoshi, M.; Pietka, M.; Stappers, B.; Wise, M.; Zarka, P.

2018-04-01

With their wide fields of view and often relatively long coverage of any position in the sky in imaging survey mode, modern radio telescopes provide a data stream that is naturally suited to searching for rare transients. However, Radio Frequency Interference (RFI) can show up in the data stream in similar ways to such transients, and thus the normal pre-treatment of filtering RFI (flagging) may also remove astrophysical transients from the data stream before imaging. In this paper we investigate how standard flagging affects the detectability of such transients by examining the case of transient detection in an observing mode used for Low Frequency Array (LOFAR; van Haarlem et al., 2013) surveys. We quantify the fluence range of transients that would be detected, and the reduction of their SNR due to partial flagging. We find that transients with a duration close to the integration sampling time, as well as bright transients with durations on the order of tens of seconds, are completely flagged. For longer transients on the order of several tens of seconds to minutes, the flagging effects are not as severe, although part of the signal is lost. For these transients, we present a modified flagging strategy which mitigates the effect of flagging on transient signals. We also present a script which uses the differences between the two strategies, and known differences between transient RFI and astrophysical transients, to notify the observer when a potential transient is in the data stream.

Development and comparison of different intensity duration ...

African Journals Online (AJOL)

Nigerian Journal of Technology ... Microsoft Excel software was used to develop exponential, logarithmic and power intensity-duration-frequency models for return period (T) of duration-frequency models for return period (T) of between 2 years and 100 years using rainfall intensity data for durations of 2, 5, 10, 15, 30, 60, ...

Prompts to disrupt sitting time and increase physical activity at work, 2011-2012.

Science.gov (United States)

Swartz, Ann M; Rote, Aubrianne E; Welch, Whitney A; Maeda, Hotaka; Hart, Teresa L; Cho, Young Ik; Strath, Scott J

2014-05-01

The objective of this study was to assess change in sitting and physical activity behavior in response to a workplace intervention to disrupt prolonged sitting time. Sixty office workers were randomized to either a Stand group (n = 29), which received hourly prompts (computer-based and wrist-worn) to stand up, or a Step group (n = 31), which received the same hourly prompts and an additional prompt to walk 100 steps or more upon standing. An ActivPAL monitor was used to assess sitting and physical activity behavior on the same 3 consecutive workdays during baseline and intervention periods. Mixed-effect models with random intercepts and random slopes for time were performed to assess change between groups and across time. Both groups significantly reduced duration of average sitting bouts (Stand group, by 16%; Step group, by 19%) and the number of sitting bouts of 60 minutes or more (Step group, by 36%; Stand group, by 54%). The Stand group significantly reduced total sitting time (by 6.6%), duration of the longest sitting bout (by 29%), and number of sitting bouts of 30 minutes or more (by 13%) and increased the number of sit-to-stand transitions (by 15%) and standing time (by 23%). Stepping time significantly increased in the Stand (by 14%) and Step (by 29%) groups, but only the Step group significantly increased (by 35%) the number of steps per workday. Differences in changes from baseline to intervention between groups were not significant for any outcome. Interventions that focus on disrupting sitting time only in the workplace may result in less sitting. When sitting time disruptions are paired with a physical activity prompt, people may be more likely to increase their workday physical activity, but the effect on sitting time may be attenuated.

Pavlovian conditioning of psychomotor stimulant-induced behaviours: has convenience led us astray?

Science.gov (United States)

Martin-Iverson, M.T.; Fawcett, S.L.

1996-01-01

In order to classically condition the behavioural effects of psychomotor stimulants within a test context, rats were treated for 10 days with (+)-amphetamine (1.5mg/kg), (+)-4-propyl-9-hydroxynaphthoxazine (PHNO, 30µg/kg) or vehicle prior to a 1h placement into a test box. Conditioned behavioural effects were then measured in the previously drug-paired context after a vehicle injection (drug-free test day). Each rat was videotaped for the 1h test box exposure on days 1, 4, 7 and 10 of the drug conditioning trials, and on the drug-free test day. Eleven of 28 behaviours that were scored for frequency, duration and mean bout duration (bout length) were significantly influenced by at least one of the two drugs. Amphetamine predominantly increased bout lengths while PHNO predominantly increased bout frequency. Only two measures that were influenced by the drugs exhibited clear increases over controls in a manner consistent with a classical conditioning interpretation. Behavioural sensitization clearly occurred to some of the effects of amphetamine and PHNO, but these were not the same effects as those increased on the non-drug day testing for classical conditioning. Most behavioural effects of amphetamine and PHNO are not classically conditioned, and behavioural sensitization to these drugs, while perhaps context-specific, is not due to classical conditioning. Automated measures of behaviours have provided misleading evidence concerning the similarity among behavioural effects of stimulants, sensitization and effects of exposure to an environment previously paired with stimulants. Analysis of transitions between behaviours does not support the view that stimulants increase switching or response competition, or that behavioural reorganization is responsible for sensitization. Rather, it is suggested that stimulants selectively facilitate current stimulus-guided behaviours.

[Longevity, disease, and duration of disability].

Science.gov (United States)

Matsushita, S

1996-12-01

Disability and the resulting lowered quality of life are serious issues accompanying increased longevity. Active life expectancy #(8) can be to used to distinguish the number of years without disability from the number with disability; increases were found in both in longevity #(9, 19). With the same rate of age-related new disability in the cohorts between 1970 and 1990, the total disability increased three fold #(11). In elderly patients I showed that 1) the duration of disability of those at a specific age at death (predeath) #(1) increased with age, and it decreased in those who remained without disability, 2) the cumulative number of days of disability for patients who died at a specific age (a convolution function of predeath and mortality) #(2), approached a normal distribution, which is consistent with the central limit theorem, 3) competing risk with chronic disease in a patient greatly affects the incidence and duration of disability, 4) using the central limit theorem we can predict that preventing dementia will retard premature rectangularization of the disability-free survival curve, and will thus reduce the total disability, 5) disability is an example of how variation and selection of chronic diseases (disease Darwinism) can alter population structure. Insights into the evolution of senescence #(14-21), pleiotropy, and slower rates of molecular evolution in the core than at the border #(26, 27), reveal that the central nervous system is relatively robust and conservative for pleiotropy and may senesce relatively slowly, which support a new way of thinking #(3, 4) about old age. To minimize disability, public knowledge and education about an ideal lifestyle and the evolution of senescence is essential.

Sleep duration, life satisfaction and disability.

Science.gov (United States)

Pagan, Ricardo

2017-04-01

Although sleep is considered an essential part of individuals' lives, there are no previous studies analysing how sleep duration affects the levels of life satisfaction reported by males and females with disabilities. To analyse and compare the impact of hours of sleep on life satisfaction scores reported by people without and with disabilities (stratified by sex) in Germany. Using data taken from the German Socio-Economic Panel for the period 2008-2013, we estimate life satisfaction equations for males and females (running a fixed-effects model) which include a set of variables measuring the number of sleep hours on workdays and weekends. A higher number of sleep hours on workdays increase life satisfaction for all males and females. However, the contribution of each hour of sleep on workdays is greater for males with disabilities in terms of life satisfaction, whereas for females no significant differences by disability status have been found. Although sleep hours on weekends also increase life satisfaction, the magnitude of the coefficients is relatively higher than that found for the corresponding hours of sleep on workdays, but only for the male sample (disabled or not). The participation and commitment of policymakers, governments, trade unions, employers, and health care professionals are key aspects for developing and formulating new guidelines and specific measures that promote a healthy lifestyle and increase sleep duration. Such guidelines and measures are of essence for people with disabilities who are employed (e.g. using brief sleep opportunities during prolonged work periods, which can contribute to reducing fatigue, stress and anxiety). Copyright © 2016 Elsevier Inc. All rights reserved.

A randomized trial comparing structured and lifestyle goals in an internet-mediated walking program for people with type 2 diabetes

Directory of Open Access Journals (Sweden)

Fortlage Laurie A

2007-11-01

Full Text Available Abstract Background The majority of individuals with type 2 diabetes do not exercise regularly. Pedometer-based walking interventions can help; however, pedometer-based interventions targeting only total daily accumulated steps might not yield the same health benefits as physical activity programs specifying a minimum duration and intensity of physical activity bouts. Methods This pilot randomized trial compared two goal-setting strategies: 1 lifestyle goals targeting total daily accumulated step counts and 2 structured goals targeting bout steps defined as walking that lasts for 10 minutes or longer at a pace of at least 60 steps per minute. We sought to determine which goal-setting strategy was more effective at increasing bout steps. Participants were sedentary adults with type 2 diabetes. All participants: wore enhanced pedometers with embedded USB ports; uploaded detailed, time-stamped step-count data to a website called Stepping Up to Health; and received automated step-count feedback, automatically calculated goals, and tailored motivational messages throughout the six-week intervention. Only the automated goal calculations and step-count feedback differed between the two groups. The primary outcome of interest was increase in steps taken during the previously defined bouts of walking (lasting at least 10 minutes or longer at a pace of at least 60 steps per minute between baseline and end of the intervention. Results Thirty-five participants were randomized and 30 (86% completed the pilot study. Both groups significantly increased bout steps, but there was no statistically significant difference between groups. Among study completers, bout steps increased by 1921 ± 2729 steps a day. Those who received lifestyle goals were more satisfied with the intervention (p = 0.006 and wore the pedometer more often (p Conclusion In this six-week intervention, Lifestyle Goals group participants achieved increases in bout steps comparable to the

The Effects of Long-Duration Spaceflight on Training Retention and Transfer

Science.gov (United States)

Barshi, Immanuel; Healy, Alice; Dempsey, Donna L.; McGuire, Kerry M.; Landon, Lauren B.

2018-01-01

Training our crew members for long duration, exploration-class missions will have to maximize long-term retention and transfer of the trained skills. The expected duration of the missions, our inability to predict all the possible tasks the crew will be called upon to perform, and the low training-to-mission time ratio require that the training be maximally effective such that the skills acquired during training will be retained and will be transferrable across a wide range of specific tasks that are different from the particular tasks used during training. However, to be able to design training that can achieve these ambitious goals, we must first understand the ways in which long-duration spaceflight affects training retention and transfer. Current theories of training retention and transfer are largely based on experimental studies conducted at university laboratories using undergraduate students as participants. Furthermore, all such studies have been conducted on Earth. We do not know how well the results of these studies predict the performance of crew members. More specifically, we do not know how well the results of these studies predict the performance of crew members in space and especially during long-duration missions. To address this gap in our knowledge, the current on-going study seeks to test the null hypothesis that performance of university undergraduate students on Earth on training retention and transfer tests do in fact predict accurately the performance of crew members during long-duration spaceflights. To test this hypothesis, the study employs a single 16-month long experimental protocol with 3 different participant groups: undergraduate university students, crew members on the ground, and crew members in space. Results from this study will be presented upon its completion. This poster presents results of study trials of the two tasks used in this study: a data entry task and a mapping task. By researching established training principles, by

Combinations of Epoch Durations and Cut-Points to Estimate Sedentary Time and Physical Activity among Adolescents

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Fröberg, Andreas; Berg, Christina; Larsson, Christel; Boldemann, Cecilia; Raustorp, Anders

2017-01-01

The purpose of the current study was to investigate how combinations of different epoch durations and cut-points affect the estimations of sedentary time and physical activity in adolescents. Accelerometer data from 101 adolescents were derived and 30 combinations were used to estimate sedentary time, light, moderate, vigorous, and combined…

Countermeasures to Mitigate the Negative Impact of Sensory Deprivation and Social Isolation in Long-Duration Space Flight

Science.gov (United States)

Bachman, Katharine Ridgeway OBrien; Otto, Christian; Leveton, Lauren

2012-01-01

Long-duration space flight presents several challenges to the behavioral health of crew members. The environment that they are likely to experience will be isolated, confined, and extreme (ICE) and, as such, crew members will experience extreme sensory deprivation and social isolation. The current paper briefly notes the behavioral, cognitive, and affective consequences of psychological stress induced by ICE environments and proposes nine countermeasures aimed at mitigating the negative effects of sensory deprivation and social isolation. Implementation of countermeasures aims to maintain successful crew performance and psychological well-being in a long-duration space flight mission.

Growth performance, haematology and cost benefit of growing rabbits reared on different feed access times and restriction durations

Directory of Open Access Journals (Sweden)

Obasa, O.A

2016-06-01

Full Text Available Sixty growing rabbits of mixed breeds and sexes were used for 10 wk in a 4 x 3 factorial experimental design to test for the effect of different feed access times (2, 4, 6 and 24 h and different restriction durations (2, 4 and 6 wk on the performance, haematological parameters and cost benefits of growing rabbits. Data obtained were subject to a 2�way analysis of variance. Results showed significantly higher (p0.05 across the feed access time and restriction duration. White blood cell was higher in growing rabbits on 2-h feed access time for 6-wk duration of restriction while all other parameters measured for haematology were not significantly affected by the feed access time and restriction duration. Total cost of feed consumed was highest in growing rabbits maintained on 24-h feed access time. Cost of feed per kg weight gain was not significantly influenced across the feed access times and the restriction durations. It was concluded that for a reduced cost of feeding without an adverse effect on the performance and haematological profile, growing rabbits should be raised on not less than 4-h feed access time for 2-wk restriction duration.

Sleep Duration and Area-Level Deprivation in Twins.

Science.gov (United States)

Watson, Nathaniel F; Horn, Erin; Duncan, Glen E; Buchwald, Dedra; Vitiello, Michael V; Turkheimer, Eric

2016-01-01

We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions. Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from the University of Washington Twin Registry. Participants self-reported habitual sleep duration. The Singh Index was determined by linking geocoding addresses to 17 indicators at the census-tract level using data from Census of Washington State and Census Tract Cartographic Boundary Files from 2000 and 2010. Data were analyzed using univariate and bivariate genetic decomposition and quantitative genetic interaction models that assessed A (additive genetics), C (common environment), and E (unique environment) main effects of the Singh Index on sleep duration and allowed the magnitude of residual ACE variance components in sleep duration to vary with the Index. The sample had a mean age of 38.2 y (standard deviation [SD] = 18), and was predominantly female (62%) and Caucasian (91%). Mean sleep duration was 7.38 h (SD = 1.20) and the mean Singh Index score was 0.00 (SD = 0.89). The heritability of sleep duration was 39% and the Singh Index was 12%. The uncontrolled phenotypic regression of sleep duration on the Singh Index showed a significant negative relationship between area-level deprivation and sleep length (b = -0.080, P sleep duration. For the quasi-causal bivariate model, there was a significant main effect of E (b(0E) = -0.063; standard error [SE] = 0.30; P sleep duration were significant for both A (b(0Au) = 0.734; SE = 0.020; P deprivation has a quasi-causal association with sleep duration, with greater deprivation being related to shorter sleep. As area-level deprivation increases, unique genetic and nonshared environmental residual variance in sleep duration increases. © 2016 Associated Professional Sleep Societies, LLC.

Sleep Duration and Area-Level Deprivation in Twins

Science.gov (United States)

Watson, Nathaniel F.; Horn, Erin; Duncan, Glen E.; Buchwald, Dedra; Vitiello, Michael V.; Turkheimer, Eric

2016-01-01

Study Objectives: We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions. Methods: Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from the University of Washington Twin Registry. Participants self-reported habitual sleep duration. The Singh Index was determined by linking geocoding addresses to 17 indicators at the census-tract level using data from Census of Washington State and Census Tract Cartographic Boundary Files from 2000 and 2010. Data were analyzed using univariate and bivariate genetic decomposition and quantitative genetic interaction models that assessed A (additive genetics), C (common environment), and E (unique environment) main effects of the Singh Index on sleep duration and allowed the magnitude of residual ACE variance components in sleep duration to vary with the Index. Results: The sample had a mean age of 38.2 y (standard deviation [SD] = 18), and was predominantly female (62%) and Caucasian (91%). Mean sleep duration was 7.38 h (SD = 1.20) and the mean Singh Index score was 0.00 (SD = 0.89). The heritability of sleep duration was 39% and the Singh Index was 12%. The uncontrolled phenotypic regression of sleep duration on the Singh Index showed a significant negative relationship between area-level deprivation and sleep length (b = −0.080, P sleep duration. For the quasi-causal bivariate model, there was a significant main effect of E (b0E = −0.063; standard error [SE] = 0.30; P sleep duration were significant for both A (b0Au = 0.734; SE = 0.020; P sleep duration, with greater deprivation being related to shorter sleep. As area-level deprivation increases, unique genetic and nonshared environmental residual variance in sleep duration increases. Citation: Watson NF, Horn E, Duncan GE, Buchwald D, Vitiello MV, Turkheimer E. Sleep duration and area

Investigating the role of time in affective forecasting: temporal influences on forecasting accuracy.

NARCIS (Netherlands)

Finkenauer, C.; Gallucci, M.; van Dijk, W.; Pollmann, M.M.H.

2007-01-01

Using extensive diary data from people taking their driver's license exam, the authors investigated the role of time in affective forecasting accuracy. Replicating existing findings, participants grossly overestimated the intensity and duration of their negative affect after failure and only

Unemployment Duration over the Business Cycle

DEFF Research Database (Denmark)

Rosholm, Michael

1996-01-01

In this paper I study the way in which individual unemployment durations vary over the business cycle, as measured by the aggregate unemployment rate. I decompose the cyclical variations in observed unemployment durations into a composition al and a general part. The compositional part consists...

Sociosexuality, Morningness–Eveningness, and Sleep Duration

Directory of Open Access Journals (Sweden)

Christoph Randler

2016-01-01

Full Text Available Morningness–eveningness is the preference for different times of day for activity and sleep. Here, we addressed the effects of sleep behavior and morningness–eveningness on sociosexuality. Three hundred students (M age = 22.75 years, with 95% between 18 and 28 participated online, answering questions about morningness–eveningness (rMEQ [Reduced Morningness–Eveningness Questionnaire], midpoint of sleep on free days (MSF, sleep duration, and the Sociosexuality Orientation Inventory–Revised (SOI-R. The SOI-R contains three subscales, Behavior, Attitude, and Desire. Evening orientation and short sleep duration were related to a higher total SOI-R and to the three subscales. Based on the linear models, the strongest effect on sociosexuality was produced by gender (27% explained variance while age accounted for 6% of variance. Nonadditive variance explained by sleep–wake behavior was 7% (MSF, 4% (sleep duration, and 4% (rMEQ scores; 3% rMEQ-based typology. Older age was related to less-restricted sociosexuality, and men were less restricted than women in Attitude and Desire. Sleep duration and rMEQ scores were associated with Attitude and Desire; but only MSF was significantly related to Behavior. The data show that sleep–wake variables are associated with sociosexuality, with evening orientation and shorter sleep duration being related to a less-restricted sociosexuality.

Ultrasonic Vocalizations as a Measure of Affect in Preclinical Models of Drug Abuse: A Review of Current Findings.

Science.gov (United States)

Barker, David J; Simmons, Steven J; West, Mark O

2015-01-01

The present review describes ways in which ultrasonic vocalizations (USVs) have been used in studies of substance abuse. Accordingly, studies are reviewed which demonstrate roles for affective processing in response to the presentation of drug-related cues, experimenter- and self-administered drug, drug withdrawal, and during tests of relapse/reinstatement. The review focuses on data collected from studies using cocaine and amphetamine, where a large body of evidence has been collected. Data suggest that USVs capture animals' initial positive reactions to psychostimulant administration and are capable of identifying individual differences in affective responding. Moreover, USVs have been used to demonstrate that positive affect becomes sensitized to psychostimulants over acute exposure before eventually exhibiting signs of tolerance. In the drug-dependent animal, a mixture of USVs suggesting positive and negative affect is observed, illustrating mixed responses to psychostimulants. This mixture is predominantly characterized by an initial bout of positive affect followed by an opponent negative emotional state, mirroring affective responses observed in human addicts. During drug withdrawal, USVs demonstrate the presence of negative affective withdrawal symptoms. Finally, it has been shown that drug-paired cues produce a learned, positive anticipatory response during training, and that presentation of drug-paired cues following abstinence produces both positive affect and reinstatement behavior. Thus, USVs are a useful tool for obtaining an objective measurement of affective states in animal models of substance abuse and can increase the information extracted from drug administration studies. USVs enable detection of subtle differences in a behavioral response that might otherwise be missed using traditional measures.

Theories of willpower affect sustained learning.

Science.gov (United States)

Miller, Eric M; Walton, Gregory M; Dweck, Carol S; Job, Veronika; Trzesniewski, Kali H; McClure, Samuel M

2012-01-01

Building cognitive abilities often requires sustained engagement with effortful tasks. We demonstrate that beliefs about willpower-whether willpower is viewed as a limited or non-limited resource-impact sustained learning on a strenuous mental task. As predicted, beliefs about willpower did not affect accuracy or improvement during the initial phases of learning; however, participants who were led to view willpower as non-limited showed greater sustained learning over the full duration of the task. These findings highlight the interactive nature of motivational and cognitive processes: motivational factors can substantially affect people's ability to recruit their cognitive resources to sustain learning over time.

Breastfeeding duration and early parenting behaviour: the importance of an infant-led, responsive style.

Science.gov (United States)

Brown, Amy; Arnott, Bronia

2014-01-01

Popular parenting literature promotes different approaches to caring for infants, based around variations in the use of parent-led routines and promoting infant independence. However, there is little empirical evidence of how these early behaviours affect wider parenting choices such as infant feeding. Breastfeeding often requires an infant-led approach, feeding on demand and allowing the infant to regulate intake whilst conversely formula feeding is open to greater caregiver manipulation. The infant-led style associated with breastfeeding may therefore be at odds with philosophies that encourage strict use of routine and independence. The aim of this study was to explore the association between early parenting behaviours and breastfeeding duration. Five hundred and eight mothers with an infant aged 0-12 months completed a questionnaire examining breastfeeding duration, attitudes and behaviours surrounding early parenting (e.g. anxiety, use of routine, involvement, nurturance and discipline). Participants were attendees at baby groups or participants of online parenting forums based in the UK. Formula use at birth or short breastfeeding duration were significantly associated with low levels of nurturance, high levels of reported anxiety and increased maternal use of Parent-led routines. Conversely an infant-led approach characterised by responding to and following infant cues was associated with longer breastfeeding duration. Maternal desire to follow a structured parenting approach which purports use of Parent-led routines and early demands for infant independence may have a negative impact upon breastfeeding duration. Increased maternal anxiety may further influence this relationship. The findings have important implications for Health Professionals supporting new mothers during pregnancy and the postpartum period.

Manifestation of arsenicosis patients and factors determining the duration of arsenic symptoms in Bangladesh

International Nuclear Information System (INIS)

Hossain, M.K.; Khan, M.M.H.; Alam, M.A.; Chowdhury, A.K.; Delwar Hossain, M.; Feroze Ahmed, M.; Kobayashi, Kota; Sakauchi, Fumio; Mori, Mitsuru

2005-01-01

This study analyzed a total of 1482 arsenicosis patients living in 6 of 496 upzilas (sub-districts) of Bangladesh, who were identified through household screening and then confirmed by a trained medical team headed by medical officer. Melanosis was common (97%) among them but about two-thirds (68.7%) of the patients were suffering from keratosis. Average age was 36 years and average duration of arsenic symptoms was 3 (median) years. About 50% of the patients had been drinking tubewell water more than 24 years. Melanosis was significantly associated with younger patients (P = 0.031), shallower tubewell (P = 0.005), and complication of conjunctivitis (P < 0.001). Keratosis was also significantly associated with older age (P 0.022), shallower tubewell (P < 0.001), complication of conjunctivitis (P < 0.001), bronchitis (P < 0.001), loss of appetite (P < 0.001), and wasting (P < 0.001). Duration of arsenic symptoms was significantly associated with older age (P < 0.001), male (P = 0.002), married (P < 0.001), smoking (P 0.002), longer duration of consuming tubewell water (P < 0.001), complication of conjunctivitis (P = 0.002), loss of appetite (P < 0.001), wasting (P 0.006), and social problem faced having arsenicosis (P = 0.040). Multivariate odds ratio (OR) and 95% confidence interval (CI) indicated that keratosis (OR 2.00; 95% CI: 1.56-2.56) was significantly associated with longer duration of arsenic symptoms; loss of appetite (OR = 1.40; 95% CI: 1.12-1.74) was a significant complication for longer duration. Similarly smoking (OR = 1.33; 95% CI: 1.06-1.68) was positively associated with longer duration of arsenic symptom. These findings will help the policy makers of Bangladesh to understand about the factors that may affect the severity condition of the patients through prolongation of arsenic symptoms

Sleep Duration and Breast Cancer Phenotype

International Nuclear Information System (INIS)

Khawaja, A.; Rao, S.

2013-01-01

Emerging evidence suggests that short sleep is associated with an increased risk of cancer; however, little has been done to study the role of sleep on tumor characteristics. In this study, we evaluated the relationship between sleep duration and tumor phenotype in 972 breast cancer patients. Sleep duration was inversely associated with tumor grade (univariate P= 0.032), particularly in postmenopausal women (univariate P= 0.018). This association did not reach statistical significance after adjustments for age, race, body mass index, hormone replacement therapy use, alcohol consumption, smoking, and physical activity in the entire study sample (P= 0.052), but it remained statistically significant (P= 0.049) among post-menopausal patients. We did not observe a statistically significant association between sleep duration and stage at diagnosis, ER, or HER2 receptor status. These results present a modest association between short duration of sleep and higher grade breast cancer in post-menopausal women. Further work needs to be done to validate these findings.

How Hearing Impairment Affects Sentence Comprehension: Using Eye Fixations to Investigate the Duration of Speech Processing

DEFF Research Database (Denmark)

Wendt, Dorothea; Kollmeier, Birger; Brand, Thomas

2015-01-01

; this measure uses eye fixations recorded while the participant listens to a sentence. Eye fixations toward a target picture (which matches the aurally presented sentence) were measured in the presence of a competitor picture. Based on the recorded eye fixations, the single target detection amplitude, which...... reflects the tendency of the participant to fixate the target picture, was used as a metric to estimate the duration of sentence processing. The single target detection amplitude was calculated for sentence structures with different levels of linguistic complexity and for different listening conditions......: in quiet and in two different noise conditions. Participants with hearing impairment spent more time processing sentences, even at high levels of speech intelligibility. In addition, the relationship between the proposed online measure and listener-specific factors, such as hearing aid use and cognitive...

Acute effects of brisk walking on sugary snack cravings in overweight people, affect and responses to a manipulated stress situation and to a sugary snack cue: a crossover study.

Science.gov (United States)

Ledochowski, Larissa; Ruedl, Gerhard; Taylor, Adrian H; Kopp, Martin

2015-01-01

Research has shown that acute exercise reduces urges for chocolate in normal weight people. This study aimed to examine the effects of an acute exercise bout on urges to consume sugary snacks, affect as well as 'psychological and physiological responses' to stress and a 'sugary snack cue', in overweight individuals. Following 3 days of chocolate-abstinence, 47 overweight, sugary snack consumers were assessed, in 2 randomly ordered conditions, in a within-subject design: 15-min brisk walk or passive control. Following each, participants completed 2 tasks: Stroop color-word interference task, and handling sugary snacks. Urges for sugary snacks, affective activation and valence were assessed. ANOVAs revealed significant condition x time interaction effects for: urges to consume sugary snacks, affective valence and activation. Obtained data show that exercise reduces urges for sugary snacks and attenuates urges in response to the stress situation and the cue in overweight people.

Acute effects of brisk walking on sugary snack cravings in overweight people, affect and responses to a manipulated stress situation and to a sugary snack cue: a crossover study.

Directory of Open Access Journals (Sweden)

Larissa Ledochowski

Full Text Available Research has shown that acute exercise reduces urges for chocolate in normal weight people. This study aimed to examine the effects of an acute exercise bout on urges to consume sugary snacks, affect as well as 'psychological and physiological responses' to stress and a 'sugary snack cue', in overweight individuals. Following 3 days of chocolate-abstinence, 47 overweight, sugary snack consumers were assessed, in 2 randomly ordered conditions, in a within-subject design: 15-min brisk walk or passive control. Following each, participants completed 2 tasks: Stroop color-word interference task, and handling sugary snacks. Urges for sugary snacks, affective activation and valence were assessed. ANOVAs revealed significant condition x time interaction effects for: urges to consume sugary snacks, affective valence and activation. Obtained data show that exercise reduces urges for sugary snacks and attenuates urges in response to the stress situation and the cue in overweight people.

Strenuous physical exercise adversely affects monocyte chemotaxis

DEFF Research Database (Denmark)

Czepluch, Frauke S; Barres, Romain; Caidahl, Kenneth

2011-01-01

Physical exercise is important for proper cardiovascular function and disease prevention, but it may influence the immune system. We evaluated the effect of strenuous exercise on monocyte chemotaxis. Monocytes were isolated from blood of 13 young, healthy, sedentary individuals participating...... in a three-week training program which consisted of repeated exercise bouts. Monocyte chemotaxis and serological biomarkers were investigated at baseline, after three weeks training and after four weeks recovery. Chemotaxis towards vascular endothelial growth factor-A (VEGF-A) and transforming growth factor...

Estimation of available global solar radiation using sunshine duration over South Korea

Science.gov (United States)

Das, Amrita; Park, Jin-ki; Park, Jong-hwa

2015-11-01

Besides designing a solar energy system, accurate insolation data is also a key component for many biological and atmospheric studies. But solar radiation stations are not widely available due to financial and technical limitations; this insufficient number affects the spatial resolution whenever an attempt is made to construct a solar radiation map. There are several models in literature for estimating incoming solar radiation using sunshine fraction. Seventeen of such models among which 6 are linear and 11 non-linear, have been chosen for studying and estimating solar radiation on a horizontal surface over South Korea. The better performance of a non-linear model signifies the fact that the relationship between sunshine duration and clearness index does not follow a straight line. With such a model solar radiation over 79 stations measuring sunshine duration is computed and used as input for spatial interpolation. Finally monthly solar radiation maps are constructed using the Ordinary Kriging method. The cross validation results show good agreement between observed and predicted data.

Age-specific neural strategies to maintain motor performance after an acute social stress bout.

Science.gov (United States)

Mehta, Ranjana K; Rhee, Joohyun

2017-07-01

Stress due to cognitive demands and fatigue have shown to impair motor performance in older adults; however, the effect of social stress and its influence on prefrontal cortex (PFC) functioning in older adults during upper extremity motor performance tasks is not known. The present study explored the after-effects of an acute social stress bout on neural strategies, measured using PFC and hand/arm muscle activation, and adopted by younger and older adults to maintain handgrip force control. Nine older [74.1 (6.5) years; three men, six women] and ten younger [24.2 (5.0) years, four men, six women] adults performed handgrip force control trials at 30% maximum voluntary contractions before and after the Trier Social Stress Test (TSST). PFC activity was measured using functional near infrared spectroscopy and muscle activity from the flexor and extensor carpi radialis (FCR/ECR) was measured using electromyography. In general, aging was associated with decreased force steadiness and force complexity with a concomitant increase in bilateral PFC activity. While motor performance remained comparable before and after the TSST stress session in both age groups, the associated neural strategies differed between groups. While the stress condition was associated with lower FCR and ECR activity in younger adults despite no change in the PFC activation, stress was associated with increases in FCR activity in older adults. This stress-related compensatory neural strategy of increasing hand/arm muscle activation, potentially via the additional recruitment of the stress-motor neural circuitry, may have played a role in maintaining motor performance in older adults.

Effects of pulse duration on magnetostimulation thresholds

Energy Technology Data Exchange (ETDEWEB)

Saritas, Emine U., E-mail: saritas@ee.bilkent.edu.tr [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara 06800 (Turkey); National Magnetic Resonance Research Center (UMRAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Goodwill, Patrick W. [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Conolly, Steven M. [Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720-1762 (United States); Department of EECS, University of California, Berkeley, California 94720-1762 (United States)

2015-06-15

Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

Effects of pulse duration on magnetostimulation thresholds

International Nuclear Information System (INIS)

Saritas, Emine U.; Goodwill, Patrick W.; Conolly, Steven M.

2015-01-01

Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

Sleep duration and obesity in children: A systematic review and meta-analysis of prospective cohort studies.

Science.gov (United States)

Li, Lian; Zhang, Shuang; Huang, Yubei; Chen, Kexin

2017-04-01

Childhood obesity is a major public problem worldwide, and sleep duration may be associated with childhood obesity. We conducted a systematic review and meta-analysis of prospective cohort studies to estimate the associations between sleep duration and obesity/body mass index (BMI) in children. PubMed, Embase and the Cochrane Library were searched. For the meta-analysis, the pooled relative risk (RR) and 95% confidence intervals (CI) were estimated to reveal the association between short sleep duration and obesity. For the review, the outcomes focused on BMI change or subsequent BMI status. A total of 12 studies (15 populations) met the criteria for inclusion in the meta-analysis. Short sleep duration was significantly associated with obesity (RR: 1.45; 95% CI: 1.14-1.85). After excluding two cohorts that substantially affected the heterogeneity, the pooled results remained significant (RR: 1.30; 95% CI: 1.20-1.42), and the association was not substantially altered in the subgroup analysis. In addition, we summarised 24 studies that met the criteria for our review of the relationship between sleeping and BMI. The present meta-analysis indicated that short sleep duration increased the risk of childhood obesity. Public health efforts that encourage children to have sufficient sleep time may be important in combating obesity. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Acute Impact of Moderate-Intensity and Vigorous-Intensity Exercise Bouts on Daily Physical Activity Energy Expenditure in Postmenopausal Women

Directory of Open Access Journals (Sweden)

Xuewen Wang

2011-01-01

Full Text Available This study determined whether performing a single moderate- or vigorous-intensity exercise bout impacts daily physical activity energy expenditure (PAEE, by accelerometer. Overweight/obese postmenopausal women underwent a 5-month caloric restriction and moderate- (n=18 or vigorous-intensity (n=18 center-based aerobic exercise intervention. During the last month of intervention, in women performing moderate-intensity exercise, PAEE on days with exercise (577.7±219.7 kcal⋅d−1 was higher (P=.011 than on days without exercise (450.7±140.5 kcal⋅d−1; however, the difference (127.0±188.1 kcal⋅d−1 was much lower than the energy expended during exercise. In women performing vigorous-intensity exercise, PAEE on days with exercise (450.6±153.6 kcal⋅d−1 was lower (P=.047 than on days without exercise (519.2±127.4 kcal⋅d−1. Thus, women expended more energy on physical activities outside of prescribed exercise on days they did NOT perform center-based exercise, especially if the prescribed exercise was of a higher intensity.

Validation of the Actigraph GT3X and ActivPAL Accelerometers for the Assessment of Sedentary Behavior

Science.gov (United States)

Kim, Youngdeok; Barry, Vaughn W.; Kang, Minsoo

2015-01-01

This study examined (a) the validity of two accelerometers (ActiGraph GT3X [ActiGraph LLC, Pensacola, FL, USA] and activPAL [PAL Technologies Ltd., Glasgow, Scotland]) for the assessment of sedentary behavior; and (b) the variations in assessment accuracy by setting minimum sedentary bout durations against a proxy for direct observation using an…

Type III Radio Burst Duration and SEP Events

Science.gov (United States)

Gopalswamy, N.; Makela, P.; Xie, H.

2010-01-01

Long-duration (>15 min), low-frequency (25 MeV. The 1-MHz duration of the type III burst (28 rein) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. This study suggests that the type III burst duration may not be a good indicator of an SEP event, consistent with the statistical study of Cliver and Ling (2009, ApJ ).

Duration of patients’ visits to the hospital emergency department

Directory of Open Access Journals (Sweden)

Karaca Zeynal

2012-11-01

Full Text Available Abstract Background Length of stay is an important indicator of quality of care in Emergency Departments (ED. This study explores the duration of patients’ visits to the ED for which they are treated and released (T&R. Methods Retrospective data analysis and multivariate regression analysis were conducted to investigate the duration of T&R ED visits. Duration for each visit was computed by taking the difference between admission and discharge times. The Healthcare Cost and Utilization Project (HCUP State Emergency Department Databases (SEDD for 2008 were used in the analysis. Results The mean duration of T&R ED visit was 195.7 minutes. The average duration of ED visits increased from 8 a.m. until noon, then decreased until midnight at which we observed an approximately 70-minute spike in average duration. We found a substantial difference in mean duration of ED visits (over 90 minutes between Mondays and other weekdays during the transition time from the evening of the day before to the early morning hours. Black / African American patients had a 21.4-minute longer mean duration of visits compared to white patients. The mean duration of visits at teaching hospitals was substantially longer than at non-teaching hospitals (243.8 versus 175.6 minutes. Hospitals with large bed size were associated with longer duration of visits (222.2 minutes when compared to hospitals with small bed size (172.4 minutes or those with medium bed size (166.5 minutes. The risk-adjusted results show that mean duration of visits on Mondays are longer by about 4 and 9 percents when compared to mean duration of visits on non-Monday workdays and weekends, respectively. Conclusions The duration of T&R ED visits varied significantly by admission hour, day of the week, patient volume, patient characteristics, hospital characteristics and area characteristics.

Simulative Global Warming Negatively Affects Cotton Fiber Length through Shortening Fiber Rapid Elongation Duration.

Science.gov (United States)

Dai, Yanjiao; Yang, Jiashuo; Hu, Wei; Zahoor, Rizwan; Chen, Binglin; Zhao, Wenqing; Meng, Yali; Zhou, Zhiguo

2017-08-23

Global warming could possibly increase the air temperature by 1.8-4.0 °C in the coming decade. Cotton fiber is an essential raw material for the textile industry. Fiber length, which was found negatively related to the excessively high temperature, determines yarn quality to a great extent. To investigate the effects of global warming on cotton fiber length and its mechaism, cottons grown in artificially elevated temperature (34.6/30.5 °C, T day /T night ) and ambient temperature (31.6/27.3 °C) regions have been investigated. Becaused of the high sensitivities of enzymes V-ATPase, PEPC, and genes GhXTH1 and GhXTH2 during fiber elongation when responding to high temperature stress, the fiber rapid elongation duration (FRED) has been shortened, which led to a significant suppression on final fiber length. Through comprehensive analysis, T night had a great influence on fiber elongation, which means T n could be deemed as an ideal index for forecasting the degree of high temperature stress would happen to cotton fiber property in future. Therefore, we speculate the global warming would bring unfavorable effects on cotton fiber length, which needs to take actions in advance for minimizing the loss in cotton production.

Association between QRS duration and obstructive sleep apnea.

Science.gov (United States)

Gupta, Shuchita; Cepeda-Valery, Beatriz; Romero-Corral, Abel; Shamsuzzaman, Abu; Somers, Virend K; Pressman, Gregg S

2012-12-15

Both obstructive sleep apnea (OSA) and prolonged QRS duration are associated with hypertension, heart failure, and sudden cardiac death. However, possible links between QRS duration and OSA have not been explored. Cross-sectional study of 221 patients who underwent polysomnography at our center. Demographics, cardiovascular risk factors and ECG were collected to explore a relationship between OSA and QRS duration. The apnea-hypopnea index (AHI) was positively correlated with QRS duration (r = 0.141, p = 0.03). Patients were divided into 3 groups: AHI 30 (55). The mean QRS duration prolonged significantly as OSA worsened (AHI 30, 95 ± 19.9 ms, p = 0.001). QRS ≥ 100 ms was present in 12.7% of patients with severe OSA compared with 0% in the rest of the sample (p < 0.0001). After adjustment for age, race, and cardiovascular risk factors, this association remained significant in women but not in men. QRS duration and OSA were significantly associated. Severity of OSA independently predicted prolonged QRS in women but not men. Nevertheless, prolongation of QRS duration in either sex may potentiate arrhythmic risks associated with OSA.

Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction

Science.gov (United States)

Watson, Nathaniel F.; Harden, Kathryn Paige; Buchwald, Dedra; Vitiello, Michael V.; Pack, Allan I.; Strachan, Eric; Goldberg, Jack

2014-01-01

Objective: We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms. Method: Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration. Results: Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%). Conclusion: Genetic contributions to depressive symptoms increase at both short and long sleep durations. Citation: Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358. PMID:24497663

duration diabetes mellitus

African Journals Online (AJOL)

... group, type of diabetes, age of onset and duration of diabetes), presence of retinopathy, markers of nephropathy and biochemical variables. ... type 2 diabetes and for each ethnic group. Results. ... time of diabetes diagnosis in blacks than Indians. In the type ... countries, minority groups and disadvantaged communities in.

High-threshold motor unit firing reflects force recovery following a bout of damaging eccentric exercise

Science.gov (United States)

Macgregor, Lewis J.

2018-01-01

Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; pmotor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures. PMID:29630622

High-threshold motor unit firing reflects force recovery following a bout of damaging eccentric exercise.

Science.gov (United States)

Macgregor, Lewis J; Hunter, Angus M

2018-01-01

Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p exercise. Mean motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; pexercise. The firing rate of high-threshold motor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures.

Adaptation to an Illusory Duration: Nothing Like the Real Thing?

Directory of Open Access Journals (Sweden)

John Hotchkiss

2012-05-01

Full Text Available Recent work has shown that adapting to a visual or auditory stimulus of a particular duration leads to a repulsive distortion of the perceived duration of a subsequently presented test stimulus. This distortion seems to be modality-specific and manifests itself as an expansion or contraction of perceived duration dependent upon whether the test stimulus is longer or shorter than the adapted duration. It has been shown (Berger et al 2003, Journal of Vision 3, 406–412 that perceived events can be as effective as actual events in inducing improvements in performance. In light of this, we investigated whether an illusory visual duration was capable of inducing a duration after-effect in a visual test stimulus that was actually no different in duration from the adaptor. Pairing a visual stimulus with a concurrent auditory stimulus of subtly longer or shorter duration expands or contracts the duration of the visual stimulus. We mapped out this effect and then chose two auditory durations (one long, one short that produced the maximum distortion in the perceived duration of the visual stimulus. After adapting to this bimodal stimulus, our participants were asked to reproduce a visual duration. Group data showed that participants, on average, reproduced the physical duration of the visual test stimulus accurately; in other words, there was no consistent effect of adaptation to an illusory duration.

Habitual sleep durations and subjective sleep quality predict white matter differences in the human brain

Directory of Open Access Journals (Sweden)

Sakh Khalsa

2017-06-01

Full Text Available Self-imposed short sleep durations are increasingly commonplace in society, and have considerable health and performance implications for individuals. Reduced sleep duration over multiple nights has similar behavioural effects to those observed following acute total sleep deprivation, suggesting that lack of sleep affects brain function cumulatively. A link between habitual sleep patterns and functional connectivity has previously been observed, and the effect of sleep duration on the brain's intrinsic functional architecture may provide a link between sleep status and cognition. However, it is currently not known whether differences in habitual sleep patterns across individuals are related to changes in the brain's white matter, which underlies structural connectivity. In the present study we use diffusion–weighted imaging and a group comparison application of tract based spatial statistics (TBSS to investigate changes to fractional anisotropy (FA and mean diffusivity (MD in relation to sleep duration and quality, hypothesising that white matter metrics would be positively associated with sleep duration and quality. Diffusion weighted imaging data was acquired from a final cohort of 33 (23–29 years, 10 female, mean 25.4 years participants. Sleep patterns were assessed for a 14 day period using wrist actigraphs and sleep diaries, and subjective sleep quality with the Pittsburgh Sleep Quality Index (PSQI. Median splits based on total sleep time and PSQI were used to create groups of shorter/longer and poorer/better sleepers, whose imaging data was compared using TBSS followed by post-hoc correlation analysis in regions identified as significantly different between the groups. There were significant positive correlations between sleep duration and FA in the left orbito-frontal region and the right superior corona radiata, and significant negative correlations between sleep duration and MD in right orbito-frontal white matter and the right

On the Limitation of Warranty Duration.

OpenAIRE

Emons, Winand

1989-01-01

This paper analyzes the frequently-observed phenomenon that firms offer product warranties that are of much shorter duration than the life expectancy of these products. It is shown that competitive equilibria may entail limitation of warranty duration if firms face adverse selection problems with respect to different consumers. Copyright 1989 by Blackwell Publishing Ltd.

Earth-Space Links and Fade-Duration Statistics

Science.gov (United States)

Davarian, Faramaz

1996-01-01

In recent years, fade-duration statistics have been the subject of several experimental investigations. A good knowledge of the fade-duration distribution is important for the assessment of a satellite communication system's channel dynamics: What is a typical link outage duration? How often do link outages exceeding a given duration occur? Unfortunately there is yet no model that can universally answer the above questions. The available field measurements mainly come from temperate climatic zones and only from a few sites. Furthermore, the available statistics are also limited in the choice of frequency and path elevation angle. Yet, much can be learned from the available information. For example, we now know that the fade-duration distribution is approximately lognormal. Under certain conditions, we can even determine the median and other percentiles of the distribution. This paper reviews the available data obtained by several experimenters in different parts of the world. Areas of emphasis are mobile and fixed satellite links. Fades in mobile links are due to roadside-tree shadowing, whereas fades in fixed links are due to rain attenuation.

Estimating potential diapause duration in Calanus finmarchicus

Science.gov (United States)

Saumweber, Whitley J.; Durbin, Edward G.

2006-11-01

Deep basins in the Gulf of Maine act as refuge for a large population of diapausing Calanus finmarchicus during the summer and fall. This population acts as the primary seed population for Georges Bank in the spring and is thought to be composed primarily of individuals that developed during the previous spring bloom. The factors affecting growth and mortality in the summer-fall population are not well understood, however, and loss terms from advection and starvation may be large. To assess the potential energetic limitation and loss of C. finmarchicus from the Gulf of Maine basins, a new nitrogen-specific respiration model has been developed for the resting stage of the species. Stage C5 C. finmarchicus were collected during July, September, and December 2003 from Wilkinson and Georges Basins. Animals were collected using both MOCNESS tows and zooplankton samplers on the Johnson Sea Link II submersible. Metabolic rates were measured using a Micro-Oxymax gas analyzer and Winkler incubation techniques both at sea and on animals kept in culture on shore. Respiration rates measured in the field were not significantly different from those measured on shore, with a mean of 130 μmol O 2 gN -1 h -1 (14.4 μmol O 2 gC -1 h -1) at 0 °C and a Q10 of 2.77 (2.58 for carbon-specific respiration). Using the nitrogen-specific rates in conjunction with visual estimates of nitrogen weight and lipid stores, we derived a discrete function for predicting potential diapause duration based on an animal's length, oil sac volume, and the in situ temperature. The maximum potential diapause duration for a C5 C. finmarchicus is predicted to range from 280 days at 0 °C to approximately 90 days at 11 °C. The maximum potential diapause duration in the Gulf of Maine is predicted to be between 3.5 and 5.5 months. These results suggest that energetic limitation may play a role in controlling the population dynamics of diapausing C. finmarchicus in the Gulf of Maine. A reassessment of the

Call Duration Characteristics based on Customers Location

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Žvinys Karolis

2014-05-01

Full Text Available Nowadays a lot of different researches are performed based on call duration distributions (CDD analysis. However, the majority of studies are linked with social relationships between the people. Therefore the scarcity of information, how the call duration is associated with a user's location, is appreciable. The goal of this paper is to reveal the ties between user's voice call duration and the location of call. For this reason we analyzed more than 5 million calls from real mobile network, which were made over the base stations located in rural areas, roads, small towns, business and entertainment centers, residential districts. According to these site types CDD’s and characteristic features for call durations are given and discussed. Submitted analysis presents the users habits and behavior as a group (not an individual. The research showed that CDD’s of customers being them in different locations are not equal. It has been found that users at entertainment, business centers are tend to talk much shortly, than people being at home. Even more CDD can be distorted strongly, when machinery calls are evaluated. Hence to apply a common CDD for a whole network it is not recommended. The study also deals with specific parameters of call duration for distinguished user groups, the influence of network technology for call duration is considered.

The Frequency and Duration of Uterine Contractions during Labour

African Journals Online (AJOL)

1974-04-17

Apr 17, 1974 ... n-e;.l. Fig. 12. Indian primigravidas: duration of contractions. Fig. 11. Indian multiparas: duration of contractions. Fig. 10. Black primigravidas (all ages): duration of con- tractiom. Indian multiparas: Fig. 11 shows the duration of con- tractions in labour of Indian multiparas studied. Again, the pattern is similar to ...

The Impact of Sleep Duration on Performance Among Competitive Athletes: A Systematic Literature Review.

Science.gov (United States)

Kirschen, Gregory W; Jones, Jason J; Hale, Lauren

2018-06-14

The athletic advantage of sleep, although commonly touted by coaches, trainers, and sports physicians, is still unclear and likely varies by sport, athletic performance metric, and length of sufficient or insufficient sleep. Although recent literature reviews have highlighted circadian and nutritional factors that influence different aspects of athletic performance, a systematic summary of the effects of sleep duration and sleep quality on performance among competitive athletes is lacking. Here we systematically review the relationship between sleep duration and sleep quality and objective athletic performance among competitive athletes across 19 studies representing 12 sports. Taken holistically, we find that the sports requiring speed, tactical strategy, and technical skill are most sensitive to sleep duration manipulations. Furthermore, longer-term sleep manipulations are more likely than acute sleep manipulations (whether deprivation or extension) to affect athletic performance. Thus, the importance of sleep for competitive athletes to achieve high performance is dependent on the demands of the sport as well as the length of sleep interventions. In light of the limited number of studies investigating sleep quality and performance, the potential relevance of subjective sleep quality remains an interesting question for future work.

INTENSITY, DURATION AND TYPE OF PHYSICAL ACTIVITY REQUIRED TO IMPROVE FUNCTION IN KNEE OSTEOARTHRITIS

Science.gov (United States)

KIRIHARA, RICARDO AKIHIRO; CATELAN, FELLIPE BRAVIM; FARIAS, FABIANE ELIZE SABINO DE; SILVA, CLEIDNÉIA APARECIDA CLEMENTE DA; CERNIGOY, CLAUDIA HELENA DE AZEVEDO; REZENDE, MÁRCIA UCHOA DE

2017-01-01

ABSTRACT Objective: To evaluate the effects of physical activity intensity, type and duration in patients with knee osteoarthritis (KOA). Methods: A retrospective study of 195 KOA patients who were followed for two years after receiving educational material about KOA with or without attending classes. The patients were evaluated at baseline and 24 months. At the evaluations, the patients answered questionnaires pertaining to pain and function (WOMAC, Lequesne, VAS and SF-36); reported the intensity, duration and type of exercise performed per week; and performed the Timed Up & Go (TUG) and Five Times Sit-to-Stand (FTSST) tests. Results: Increased age affected improvements in the TUG results (p=0.017). The type, intensity and duration of physical activity did not correlate with pain, function or quality of life improvements (p>0.05), but the TUG results were on average 4 seconds faster among the patients who practiced intense physical activity and/or exercised for more than 180 minutes per week and/or performed isolated weight training or swam compared with those who remained sedentary after 2 years (p=0.01; pbodybuilding) for relevant pain reduction and functional improvement.Level of Evidence II, Retrospective Study. PMID:28642646

Effects of NYMEX trading on IPE Brent Crude futures markets: a duration analysis

International Nuclear Information System (INIS)

Lin, S.X.; Tamvakis, M.N.

2004-01-01

Recent developments in the energy markets, and the surge and dip in crude oil prices over the last few years, have renewed the interest in the workings of the two main price setting markets: London's International Petroleum Exchange (IPE) and New York's Mercantile Exchange (NYMEX). The interaction of these two markets, when both of them are open (synchronous trading) and when only London is open (asynchronous trading), is important, in view of the fact that most participants take positions in both markets. This paper looks at how London is affected by New York by analysing the transaction duration of the IPE Brent futures contract, both when the NYMEX WTI futures contract is being traded and when NYMEX is closed. Using tick-by-tick data obtained from IPE, transaction durations are found to form two distinctive and inverted U-shaped patterns. Autoregressive conditional duration (ACD) model, first introduced by Engle and Russell, is applied to the data. Parameters of IPE morning and afternoon are significantly different from each other, underlining the dominant effects of NYMEX on IPE trading. The results from the current analysis reinforce previous results by the authors, which indicate that NYMEX is a leading price setter in crude oil futures prices and has a dominant effect on the IPE-traded contracts

Breastfeeding Duration and Early Parenting Behaviour: The Importance of an Infant-Led, Responsive Style

Science.gov (United States)

Brown, Amy; Arnott, Bronia

2014-01-01

Background Popular parenting literature promotes different approaches to caring for infants, based around variations in the use of parent-led routines and promoting infant independence. However, there is little empirical evidence of how these early behaviours affect wider parenting choices such as infant feeding. Breastfeeding often requires an infant-led approach, feeding on demand and allowing the infant to regulate intake whilst conversely formula feeding is open to greater caregiver manipulation. The infant-led style associated with breastfeeding may therefore be at odds with philosophies that encourage strict use of routine and independence. The aim of this study was to explore the association between early parenting behaviours and breastfeeding duration. Methods Five hundred and eight mothers with an infant aged 0–12 months completed a questionnaire examining breastfeeding duration, attitudes and behaviours surrounding early parenting (e.g. anxiety, use of routine, involvement, nurturance and discipline). Participants were attendees at baby groups or participants of online parenting forums based in the UK. Results Formula use at birth or short breastfeeding duration were significantly associated with low levels of nurturance, high levels of reported anxiety and increased maternal use of Parent-led routines. Conversely an infant-led approach characterised by responding to and following infant cues was associated with longer breastfeeding duration. Discussion Maternal desire to follow a structured parenting approach which purports use of Parent-led routines and early demands for infant independence may have a negative impact upon breastfeeding duration. Increased maternal anxiety may further influence this relationship. The findings have important implications for Health Professionals supporting new mothers during pregnancy and the postpartum period. PMID:24533046

Breastfeeding duration and early parenting behaviour: the importance of an infant-led, responsive style.

Directory of Open Access Journals (Sweden)

Amy Brown

Full Text Available Popular parenting literature promotes different approaches to caring for infants, based around variations in the use of parent-led routines and promoting infant independence. However, there is little empirical evidence of how these early behaviours affect wider parenting choices such as infant feeding. Breastfeeding often requires an infant-led approach, feeding on demand and allowing the infant to regulate intake whilst conversely formula feeding is open to greater caregiver manipulation. The infant-led style associated with breastfeeding may therefore be at odds with philosophies that encourage strict use of routine and independence. The aim of this study was to explore the association between early parenting behaviours and breastfeeding duration.Five hundred and eight mothers with an infant aged 0-12 months completed a questionnaire examining breastfeeding duration, attitudes and behaviours surrounding early parenting (e.g. anxiety, use of routine, involvement, nurturance and discipline. Participants were attendees at baby groups or participants of online parenting forums based in the UK.Formula use at birth or short breastfeeding duration were significantly associated with low levels of nurturance, high levels of reported anxiety and increased maternal use of Parent-led routines. Conversely an infant-led approach characterised by responding to and following infant cues was associated with longer breastfeeding duration.Maternal desire to follow a structured parenting approach which purports use of Parent-led routines and early demands for infant independence may have a negative impact upon breastfeeding duration. Increased maternal anxiety may further influence this relationship. The findings have important implications for Health Professionals supporting new mothers during pregnancy and the postpartum period.

The Duration of Motor Responses Evoked with Intracortical Microstimulation in Rats Is Primarily Modulated by Stimulus Amplitude and Train Duration.

Directory of Open Access Journals (Sweden)

Meghan Watson

Full Text Available Microstimulation of brain tissue plays a key role in a variety of sensory prosthetics, clinical therapies and research applications, however the effects of stimulation parameters on the responses they evoke remain widely unknown. In particular, the effects of parameters when delivered in the form of a stimulus train as opposed to a single pulse are not well understood despite the prevalence of stimulus train use. We aimed to investigate the contribution of each parameter of a stimulus train to the duration of the motor responses they evoke in forelimb muscles. We used constant-current, biphasic, square wave pulse trains in acute terminal experiments under ketamine anaesthesia. Stimulation parameters were systematically tested in a pair-wise fashion in the caudal forelimb region of the motor cortex in 7 Sprague-Dawley rats while motor evoked potential (MEP recordings from the forelimb were used to quantify the influence of each parameter in the train. Stimulus amplitude and train duration were shown to be the dominant parameters responsible for increasing the total duration of the MEP, while interphase interval had no effect. Increasing stimulus frequency from 100-200 Hz or pulse duration from 0.18-0.34 ms were also effective methods of extending response durations. Response duration was strongly correlated with peak time and amplitude. Our findings suggest that motor cortex intracortical microstimulations are often conducted at a higher frequency rate and longer train duration than necessary to evoke maximal response duration. We demonstrated that the temporal properties of the evoked response can be both predicted by certain response metrics and modulated via alterations to the stimulation signal parameters.

Effects of organic farming duration on field boundary vegetation in Denmark

DEFF Research Database (Denmark)

Petersen, Sune; Axelsen, Jørgen A.; Tybirk, Knud

2006-01-01

The aim of this study was to assess, whether organic dairy farming has increased the biological diversity of field boundary vegetation when compared to conventional dairy farming, and if increasing organic farming duration affected diversity. The diversity of plant species in field boundaries...... was found to be higher under organic than under conventional farming. Analysis of community patterns revealed that ruderal species and species with affinity to nutrient rich conditions were most common in conventional field borders, whereas stress-tolerant species were more abundant around organic farming....... These differences occurred only 3-4 years after conversion to organic farming....

Theories of willpower affect sustained learning.

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Eric M Miller

Full Text Available Building cognitive abilities often requires sustained engagement with effortful tasks. We demonstrate that beliefs about willpower-whether willpower is viewed as a limited or non-limited resource-impact sustained learning on a strenuous mental task. As predicted, beliefs about willpower did not affect accuracy or improvement during the initial phases of learning; however, participants who were led to view willpower as non-limited showed greater sustained learning over the full duration of the task. These findings highlight the interactive nature of motivational and cognitive processes: motivational factors can substantially affect people's ability to recruit their cognitive resources to sustain learning over time.

Physical activity, sleep duration and metabolic health in children fluctuate with the lunar cycle

DEFF Research Database (Denmark)

Sjödin, Anders Mikael; Hjorth, Mads Fiil; Damsgaard, Camilla Trab

2015-01-01

Behaviours of several animal species have been linked to lunar periodicity. Evidence for such links in humans is weak; however, recently, shorter sleep duration was reported around full moon in two small samples of adults. As restrictions in sleep duration have been shown to adversely affect...... and sleep as well as 2000 measurements of different cardiometabolic risk factors, including insulin sensitivity, appetite hormones and blood pressure, during nine lunar phases. During the period around full moon, children were 5.0 and 3.2 min per day less active, slept 2.4 and 4.1 min per night longer, had...... compared with days around half moon (both P sleep is responsible for the metabolic alterations observed around full moon. However, we have no understanding of potential mechanisms that may mediate a potential true link between childhood...

MONTE CARLO RADIATION TRANSFER SIMULATIONS OF PHOTOSPHERIC EMISSION IN LONG-DURATION GAMMA-RAY BURSTS

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Lazzati, Davide [Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, OR 97331 (United States)

2016-10-01

We present MCRaT, a Monte Carlo Radiation Transfer code for self-consistently computing the light curves and spectra of the photospheric emission from relativistic, unmagnetized jets. We apply MCRaT to a relativistic hydrodynamic simulation of a long-duration gamma-ray burst jet, and present the resulting light curves and time-dependent spectra for observers at various angles from the jet axis. We compare our results to observational results and find that photospheric emission is a viable model to explain the prompt phase of long-duration gamma-ray bursts at the peak frequency and above, but faces challenges when reproducing the flat spectrum below the peak frequency. We finally discuss possible limitations of these results both in terms of the hydrodynamics and the radiation transfer and how these limitations could affect the conclusions that we present.

Mental Summation of Temporal Duration within and across Senses.

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Kohske Takahashi

Full Text Available Perceiving, memorizing, and estimating temporal durations are key cognitive functions in everyday life. In this study, a duration summation paradigm was used to examine whether summation of temporal durations introduces an underestimation or overestimation bias, and whether this bias is common to visual and auditory modalities. Two within- or across-modality stimuli were presented sequentially for variable durations. Participants were asked to reproduce the sum of the two durations (0.6-1.1 s. We found that the sum of two durations was overestimated regardless of stimulus modalities. A subsequent control experiment indicated that the overestimation bias arose from the summation process, not perceptual or memory processes. Furthermore, we observed strong positive correlations between the overestimation bias for different sensory modalities within participants. These results suggest that the sum of two durations is overestimated, and that supra-modal processes may be responsible for this overestimation bias.

Effects of a Single Bout of Resistance Exercise in Different Volumes on Endothelium Adaptations in Healthy Animals.

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Mota, Marcelo Mendonça; Silva, Tharciano Luiz Teixeira Braga da; Macedo, Fabricio Nunes; Mesquita, Thássio Ricardo Ribeiro; Quintans, Lucindo José; Santana-Filho, Valter Joviniano de; Lauton-Santos, Sandra; Santos, Márcio Roberto Viana

2017-05-01

Resistance exercise (RE) has been recommended for patients with cardiovascular diseases. Recently, a few studies have demonstrated that the intensity of a single bout of RE has an effect on endothelial adaptations to exercise. However, there is no data about the effects of different volumes of RE on endothelium function. The aim of the study was to evaluate the effects of different volumes of RE in a single bout on endothelium-dependent vasodilatation and nitric oxide (NO) synthesis in the mesenteric artery of healthy animals. Male Wistar rats were divided into three groups: Control (Ct); low-volume RE (LV, 5 sets x 10 repetitions) and high-volume RE (HV, 15 sets x 10 repetitions). The established intensity was 70% of the maximal repetition test. After the exercise protocol, rings of mesenteric artery were used for assessment of vascular reactivity, and other mesenteric arteries were prepared for detection of measure NO production by DAF-FM fluorescence. Insulin responsiveness on NO synthesis was evaluated by stimulating the vascular rings with insulin (10 nM). The maximal relaxation response to insulin increased in the HV group only as compared with the Ct group. Moreover, the inhibition of nitric oxide synthesis (L-NAME) completely abolished the insulin-induced vasorelaxation in exercised rats. NO production showed a volume-dependent increase in the endothelial and smooth muscle layer. In endothelial layer, only Ct and LV groups showed a significant increase in NO synthesis when compared to their respective group under basal condition. On the other hand, in smooth muscle layer, NO fluorescence increased in all groups when compared to their respective group under basal condition. Our results suggest that a single bout of RE promotes vascular endothelium changes in a volume-dependent manner. The 15 sets x 10 repetitions exercise plan induced the greatest levels of NO synthesis. O exercício resistido (ER) tem sido recomendado para pacientes com doen

Is performance on probed serial recall tasks in schizophrenia related to duration of Attentional Blink?

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David P. McAllindon

2017-03-01

Full Text Available Schizophrenia is associated with a deficit in working memory, with the degree of working memory impairment related to the level of social and occupational functioning. This study tests the hypothesis that the working memory deficits in individuals with schizophrenia can be explained by slow processing of visual stimuli, as measured by the attentional blink (AB task. Individuals with schizophrenia (SC and controls (HC were recruited from an early intervention service for psychosis and the local community. Data from 16 SC (11M/5F, mean = 26.4 yo and 20 age-matched HC (11M/9F, mean = 25.8 yo were analyzed. Each subject performed an AB task to determine their AB duration, defined as the lag to reach their plateau performance (ltpp. As expected, mean AB duration in the SC group (575 ms was significantly slower than HC (460 ms; p = 0.007. Recall accuracy of the SC group on a working memory task, a 6-item probed serial recall task (PSR, was reduced compared to the HC group at a standard interstimulus interval (ISI (p = 0.002. When the individual's AB duration was then used to adjust the ISI on the PSR task to three relative ISI rates (Slow (2 × ltpp, Medium (ltpp and Fast (1/2 × ltpp, performance on the PSR task was affected by group, position and ISI and qualified by an ISI ∗ position (p = 0.001 and a trend to a triple interaction (p = 0.054. There was main effect of group at all ISIs, but group ∗ position interaction only at Slow ISI (p = 0.01. Our interpretation of the results is that absolute ISI, rather than ISI relative to AB duration, affected performance.

Criteria of immobilization duration of the affected foot in diabetic Charcot neuro-osteoarthropathy

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Anastasia Gennad'evna Demina

2014-10-01

Full Text Available Long-term offloading is the key factor in the treatment of the acute stage of Charcot foot. The indication for remobilization and transition of the affected foot to weight-bearing activities is believed to be based on two factors: the absence of the clinical signs of inflammation and results of the objective diagnostic tests. At the present time, consensus about appropriate methods sufficient for initiating weight-bearing activities after immobilization is absent. This paper discusses current data on clinical and laboratory tests and methods and describes their advantages and disadvantages.

[Associations of the work duration, sleep duration and number of holidays with an exaggerated blood pressure response during an exercise stress test among workers].

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Michishita, Ryoma; Ohta, Masanori; Ikeda, Masaharu; Jiang, Ying; Yamato, Hiroshi

2016-01-01

It has been reported that an exaggerated systolic blood pressure (ESBP) response during exercise, even if resting blood pressure is normal, is associated with an increased risk of future hypertension and cardiovascular disease (CVD). This study was designed to investigate the relationships of work duration, sleep duration and number of holidays with blood pressure response during an exercise stress test among normotensive workers. The subjects were 362 normotensive workers (79 males and 283 females; age, 49.1 years). A multi-stage graded submaximal exercise stress test was performed on each subject using an electric bicycle ergometer. The workload was increased every 3 minutes, and blood pressure was measured at rest and during the last 1 minute of each stage. In this study, an ESBP response during exercise was defined according to the criteria of the Framingham Study (peak systolic blood pressure ≥210 mmHg in males, or ≥190 mmHg in females). Working environments, work duration, sleep duration, number of holidays, and physical activity during commuting and work, and leisure time exercise duration were evaluated using a questionnaire. An ESBP response during exercise was observed in 94 (26.0%) workers. The adjusted odds ratio for the prevalence of an ESBP response during exercise was found to be significantly higher with an increase in work duration, decreases in sleep duration and number of holidays (pwork duration with lowest sleep duration and number of holidays groups had significantly higher adjusted odds ratio for the prevalence of an ESBP response during exercise than the lowest work duration with highest sleep duration and number of holidays groups (pwork duration, short sleep duration and small number of holidays.

Men and women with psychosis and the impact of illness-duration on sex-differences: The second Australian national survey of psychosis.

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Hanlon, Mary-Claire; Campbell, Linda E; Single, Natalie; Coleman, Clare; Morgan, Vera A; Cotton, Susan M; Stain, Helen J; Castle, David J

2017-10-01

We aimed to examine and compare sex-differences in people receiving treatment for psychotic illnesses in community settings, based on long or short duration of illness; expecting association between longer illness-duration and worse outcomes in women and men. Clinical, demographic and service-use data from the Survey of High Impact Psychosis were analysed by sex and duration of illness (≤5 years; ≥6 years), using independent t-tests, chi-square tests, one-way ANOVA, and Cramer's V. Of the 1825 participants, 47% had schizophrenia, 17.5% bipolar and 16.1% schizo-affective disorders. More women than men had undertaken post-school education, maintained relationships, and been living in their own homes. Women with a shorter-illness-duration showed social functioning equivalent to non-ill women in the general population. Men tended to have an early illness onset, show premorbid dysfunction, be single, show severe disability, and to use illicit substances. Men with a longer-illness-duration were very socially disadvantaged and isolated, often experiencing homelessness and substance use. Men with a short-illness-duration were most likely to be in paid employment, but two-thirds earned less than $AUD500 per fortnight. Men with longer-illness-duration showed most disability, socially and globally. Interventions should be guided by diagnosis, but also by a person's sex and duration of illness. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of duration of untreated psychosis and treatment delay on the outcomes of prolonged early intervention in psychotic disorders

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Albert, Nikolai; Melau, Marianne; Jensen, Heidi

2017-01-01

to the prolonged treatment with regards to disorganized and negative dimension. For participants with short duration from first symptom until start of SEI treatment there was a significant difference on the negative dimension favoring the prolonged OPUS treatment. The finding of an effect of prolonged treatment......The duration of untreated psychosis (DUP) has been shown to have an effect on outcome after first-episode psychosis. The premise of specialized early intervention (SEI) services is that intervention in the early years of illness can affect long-term outcomes. In this study, we investigate whether...... DUP affects treatment response after 5 years of SEI treatment compared to 2 years of SEI treatment. As part of a randomized controlled trial testing the effect of prolonged SEI treatment 400 participants diagnosed within the schizophrenia spectrum were recruited. For this specific study participants...

Influence of tow duration on catch performance of trawl survey in the Mediterranean Sea.

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Antonello Sala

Full Text Available The aim of this study was to assess the effect of tow duration on catch per unit of swept area (CPUE, trawl catch performance, and the proportion of the species caught in a trawl survey. Longer tows are expected to have a greater probability of catching species. An average of 26 species were caught in the first 30 minutes, whereas only about one additional species was caught in the next 30 minutes in longer tows. The shorter tows involved a decrement in catch weight for 11 of the 12 target species sampled, demonstrating that tow duration did affect catch per unit of swept area CPUE. The shorter tows were associated with a significant reduction of the overall CPUE in terms of weight of the main target species and of the total catch (circa 60%. The same strong reduction of around 70% was found in particular for European hake (Merluccius merluccius and surmullet (Mullus spp and 50% for Nephrops (Nephrops norvegicus. The shorter tows were less efficient in catching large-sized hake, surmullet, Nephrops, Atlantic horse mackerel (Trachurus trachurus, and poor cod (Trisopterus minutus, even though the difference was significant only for Nephrops. Regardless of the p-value statistic, these findings suggest that the continuity of survey time series would be severely impaired by changing tow duration. Further work is required to explore a way to reduce tow duration without reducing CPUE.

Smoking duration, respiratory symptoms, and COPD in adults aged ≥45 years with a smoking history

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Liu, Yong; Pleasants, Roy A; Croft, Janet B; Wheaton, Anne G; Heidari, Khosrow; Malarcher, Ann M; Ohar, Jill A; Kraft, Monica; Mannino, David M; Strange, Charlie

2015-01-01

Background The purpose of this study was to assess the relationship of smoking duration with respiratory symptoms and history of chronic obstructive pulmonary disease (COPD) in the South Carolina Behavioral Risk Factor Surveillance System survey in 2012. Methods Data from 4,135 adults aged ≥45 years with a smoking history were analyzed using multivariable logistic regression that accounted for sex, age, race/ethnicity, education, and current smoking status, as well as the complex sampling design. Results The distribution of smoking duration ranged from 19.2% (1–9 years) to 36.2% (≥30 years). Among 1,454 respondents who had smoked for ≥30 years, 58.3% were current smokers, 25.0% had frequent productive cough, 11.2% had frequent shortness of breath, 16.7% strongly agreed that shortness of breath affected physical activity, and 25.6% had been diagnosed with COPD. Prevalence of COPD and each respiratory symptom was lower among former smokers who quit ≥10 years earlier compared with current smokers. Smoking duration had a linear relationship with COPD (Psmoking status and other covariates. While COPD prevalence increased with prolonged smoking duration in both men and women, women had a higher age-adjusted prevalence of COPD in the 1–9 years, 20–29 years, and ≥30 years duration periods. Conclusion These state population data confirm that prolonged tobacco use is associated with respiratory symptoms and COPD after controlling for current smoking behavior. PMID:26229460

An investigation of the spatial selectivity of the duration after-effect.

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Maarseveen, Jim; Hogendoorn, Hinze; Verstraten, Frans A J; Paffen, Chris L E

2017-01-01

Adaptation to the duration of a visual stimulus causes the perceived duration of a subsequently presented stimulus with a slightly different duration to be skewed away from the adapted duration. This pattern of repulsion following adaptation is similar to that observed for other visual properties, such as orientation, and is considered evidence for the involvement of duration-selective mechanisms in duration encoding. Here, we investigated whether the encoding of duration - by duration-selective mechanisms - occurs early on in the visual processing hierarchy. To this end, we investigated the spatial specificity of the duration after-effect in two experiments. We measured the duration after-effect at adapter-test distances ranging between 0 and 15° of visual angle and for within- and between-hemifield presentations. We replicated the duration after-effect: the test stimulus was perceived to have a longer duration following adaptation to a shorter duration, and a shorter duration following adaptation to a longer duration. Importantly, this duration after-effect occurred at all measured distances, with no evidence for a decrease in the magnitude of the after-effect at larger distances or across hemifields. This shows that adaptation to duration does not result from adaptation occurring early on in the visual processing hierarchy. Instead, it seems likely that duration information is a high-level stimulus property that is encoded later on in the visual processing hierarchy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Computer use, sleep duration and health symptoms

DEFF Research Database (Denmark)

Nuutinen, Teija; Roos, Eva; Ray, Carola

2014-01-01

OBJECTIVES: This study investigated whether computer use is associated with health symptoms through sleep duration among 15-year olds in Finland, France and Denmark. METHODS: We used data from the WHO cross-national Health Behaviour in School-aged Children study collected in Finland, France...... and Denmark in 2010, including data on 5,402 adolescents (mean age 15.61 (SD 0.37), girls 53 %). Symptoms assessed included feeling low, irritability/bad temper, nervousness, headache, stomachache, backache, and feeling dizzy. We used structural equation modeling to explore the mediating effect of sleep...... duration on the association between computer use and symptom load. RESULTS: Adolescents slept approximately 8 h a night and computer use was approximately 2 h a day. Computer use was associated with shorter sleep duration and higher symptom load. Sleep duration partly mediated the association between...

NOX2 Inhibition Impairs Early Muscle Gene Expression Induced by a Single Exercise Bout.

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Henríquez-Olguín, Carlos; Díaz-Vegas, Alexis; Utreras-Mendoza, Yildy; Campos, Cristian; Arias-Calderón, Manuel; Llanos, Paola; Contreras-Ferrat, Ariel; Espinosa, Alejandra; Altamirano, Francisco; Jaimovich, Enrique; Valladares, Denisse M

2016-01-01

Reactive oxygen species (ROS) participate as signaling molecules in response to exercise in skeletal muscle. However, the source of ROS and the molecular mechanisms involved in these phenomena are still not completely understood. The aim of this work was to study the role of skeletal muscle NADPH oxidase isoform 2 (NOX2) in the molecular response to physical exercise in skeletal muscle. BALB/c mice, pre-treated with a NOX2 inhibitor, apocynin, (3 mg/kg) or vehicle for 3 days, were swim-exercised for 60 min. Phospho-p47(phox) levels were significantly upregulated by exercise in flexor digitorum brevis (FDB). Moreover, exercise significantly increased NOX2 complex assembly (p47(phox)-gp91(phox) interaction) demonstrated by both proximity ligation assay and co-immunoprecipitation. Exercise-induced NOX2 activation was completely inhibited by apocynin treatment. As expected, exercise increased the mRNA levels of manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx), citrate synthase (CS), mitochondrial transcription factor A (tfam) and interleukin-6 (IL-I6) in FDB muscles. Moreover, the apocynin treatment was associated to a reduced activation of p38 MAP kinase, ERK 1/2, and NF-κB signaling pathways after a single bout of exercise. Additionally, the increase in plasma IL-6 elicited by exercise was decreased in apocynin-treated mice compared with the exercised vehicle-group (p < 0.001). These results were corroborated using gp91-dstat in an in vitro exercise model. In conclusion, NOX2 inhibition by both apocynin and gp91dstat, alters the intracellular signaling to exercise and electrical stimuli in skeletal muscle, suggesting that NOX2 plays a critical role in molecular response to an acute exercise.

Effect of caffeine ingestion on anaerobic capacity quantified by different methods

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Arcoverde, Lucyana; Silveira, Rodrigo; Tomazini, Fabiano; Sansonio, André; Bertuzzi, Romulo; Andrade-Souza, Victor Amorim

2017-01-01

We investigated whether caffeine ingestion before submaximal exercise bouts would affect supramaximal oxygen demand and maximal accumulated oxygen deficit (MAOD), and if caffeine-induced improvement on the anaerobic capacity (AC) could be detected by different methods. Nine men took part in several submaximal and supramaximal exercise bouts one hour after ingesting caffeine (5 mg·kg-1) or placebo. The AC was estimated by MAOD, alternative MAOD, critical power, and gross efficiency methods. Caffeine had no effect on exercise endurance during the supramaximal bout (caffeine: 131.3 ± 21.9 and placebo: 130.8 ± 20.8 s, P = 0.80). Caffeine ingestion before submaximal trials did not affect supramaximal oxygen demand and MAOD compared to placebo (7.88 ± 1.56 L and 65.80 ± 16.06 kJ vs. 7.89 ± 1.30 L and 62.85 ± 13.67 kJ, P = 0.99). Additionally, MAOD was similar between caffeine and placebo when supramaximal oxygen demand was estimated without caffeine effects during submaximal bouts (67.02 ± 16.36 and 62.85 ± 13.67 kJ, P = 0.41) or when estimated by alternative MAOD (56.61 ± 8.49 and 56.87 ± 9.76 kJ, P = 0.91). The AC estimated by gross efficiency was also similar between caffeine and placebo (21.80 ± 3.09 and 20.94 ± 2.67 kJ, P = 0.15), but was lower in caffeine when estimated by critical power method (16.2 ± 2.6 vs. 19.3 ± 3.5 kJ, P = 0.03). In conclusion, caffeine ingestion before submaximal bouts did not affect supramaximal oxygen demand and consequently MAOD. Otherwise, caffeine seems to have no clear positive effect on AC. PMID:28617848

Striations, duration, migration and tidal response in deep tremor.

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Ide, Satoshi

2010-07-15

Deep tremor in subduction zones is thought to be caused by small repeating shear slip events on the plate interface with significant slow components. It occurs at a depth of about 30 kilometres and provides valuable information on deep plate motion and shallow stress accumulation on the fault plane of megathrust earthquakes. Tremor has been suggested to repeat at a regular interval, migrate at various velocities and be modulated by tidal stress. Here I show that some time-invariant interface property controls tremor behaviour, using precise location of tremor sources with event duration in western Shikoku in the Nankai subduction zone, Japan. In areas where tremor duration is short, tremor is more strongly affected by tidal stress and migration is inhibited. Where tremor lasts longer, diffusive migration occurs with a constant diffusivity of 10(4) m(2) s(-1). The control property may be the ratio of brittle to ductile areas, perhaps determined by the influence of mantle wedge serpentinization on the plate interface. The spatial variation of the controlling property seems to be characterized by striations in tremor source distribution, which follows either the current or previous plate subduction directions. This suggests that the striations and corresponding interface properties are formed through the subduction of inhomogeneous structure, such as seamounts, for periods as long as ten million years.

Effect of Activation Temperature and Heating Duration on Physical Characteristics of Activated Carbon Prepared from Agriculture Waste

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Tham Yee Jun

2010-01-01

Full Text Available This study was conducted to determine the physical characteristics of activated carbon prepared from durian shell in varied heating durations from 10 min to 30 min and activation temperatures of 400C and 500C. Durian shells have been characterized in term of ultimate and proximate analysis, chemical composition and thermal behaviour with a view to be used as activated carbon precursor. Durian shell activated carbon was prepared by impregnating 10g of sample in 10% (v/v concentration of phosphoric acid for 24 h, followed by carbonization at 400C and 500C with different heating durations under nitrogen atmosphere. The results showed that various treatment conditions affect the percentage of yield, BET surface area, micropore volume, and average pore diameter. The highest surface area (SBET 1024 m2/g was obtained at 500C and 20 min of heating duration with 63% of yield and 0.21 cm3/g micropore volume.

Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.

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Mary E Jung

Full Text Available Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI, the affective response to continuous vigorous-intensity exercise (CVI has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT, is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak. Three subsequent visits involved a single bout of a HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b CMI, corresponding to ∼ 40% W peak for 40 minutes, and c CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.

Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum.

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Jung, Mary E; Bourne, Jessica E; Little, Jonathan P

2014-01-01

Affect experienced during an exercise session is purported to predict future exercise behaviour. Compared to continuous moderate-intensity exercise (CMI), the affective response to continuous vigorous-intensity exercise (CVI) has consistently been shown to be more aversive. The affective response, and overall tolerability to high-intensity interval training (HIT), is less studied. To date, there has yet to be a comparison between HIT, CVI, and CMI. The purpose of this study was to compare the tolerability and affective responses during HIT to CVI and CMI. This study utilized a repeated measures, randomized, counter-balanced design. Forty-four participants visited the laboratory on four occasions. Baseline fitness testing was conducted to establish peak power output in Watts (W peak). Three subsequent visits involved a single bout of a) HIT, corresponding to 1-minute at ∼ 100% W peak and 1-minute at ∼ 20% W peak for 20 minutes, b) CMI, corresponding to ∼ 40% W peak for 40 minutes, and c) CVI, corresponding to ∼ 80% W peak for 20 minutes. The order of the sessions was randomized. Affective responses were measured before, during and after each session. Task self-efficacy, intentions, enjoyment and preference were measured after sessions. Participants reported greater enjoyment of HIT as compared to CMI and CVI, with over 50% of participants reporting a preference to engage in HIT as opposed to either CMI or CVI. HIT was considered more pleasurable than CVI after exercise, but less pleasurable than CMI at these times. Despite this participants reported being just as confident to engage in HIT as they were CMI, but less confident to engage in CVI. This study highlights the utility of HIT in inactive individuals, and suggests that it may be a viable alternative to traditionally prescribed continuous modalities of exercise for promoting self-efficacy and enjoyment of exercise.

Sleep duration moderates the association between insula activation and risky decisions under stress in adolescents and adults.

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Uy, Jessica Phuong; Galván, Adriana

2017-01-27

Insufficient sleep has been associated with increased risk-taking and poor decision-making, enhanced physiological responses to stress, and attenuated anterior insula (AI) activity to risk. The AI has also been linked to risky decision-making under acute stress. However, it is yet unknown how naturalistic sleep habits affect risky decision-making and AI activity when individuals feel stressed. In the current study, a daily diary approach was used to document participants' daily stress. Adolescents and adults reported their recent sleep duration and completed two fMRI visits during which they performed a risky decision-making task: once each when they endorsed a high and low level of stress. Results revealed that, regardless of age, individuals who reported receiving more sleep took fewer non-advantageous risks during high stress relative to those who reported receiving fewer hours of sleep per night while sleep duration was not associated with risky behavior under low stress. Among individuals who reported less sleep, those who exhibited reduced AI activation during risk-taking under high stress also took more disadvantageous risks whereas this effect was attenuated for those who reported longer sleep duration. Moreover, longer sleep duration was associated with greater functional coupling between the AI and dorsolateral prefrontal cortex (DLPFC) under high stress whereas sleep duration was not associated with AI-DLPFC functional coupling under low stress. These findings suggest that naturalistic sleep duration may amplify the effects of daily stress and alter risky decision-making behavior through interactions with the AI. Copyright © 2016. Published by Elsevier Ltd.

The relationships between exercise and affective states: a naturalistic, longitudinal study of recreational runners

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Tim Bonham

2018-01-01

Full Text Available Background Although people generally feel more positive and more energetic in the aftermath of exercise than before, longitudinal research on how exercise relates to within-person fluctuations in affect over the course of everyday life is still relatively limited. One constraint on doing such research is the need to provide participants with accelerometers to objectively record their exercise, and pagers to capture affective reports. Aims We aimed to develop a methodology for studying affect and exercise using only technology that participants already possess, namely GPS running watches and smartphones. Using this methodology, we aimed to characterize within-individual fluctuations in affective valence and arousal in relation to bouts of exercise, and explore possible moderators of these fluctuations. Methods We recruited a sample of 38 recreational runners. Participants provided daily affective reports for six weeks using their smartphones. Information on their runs was harvested from their own GPS devices via an online platform for athletes. Results Average valence and arousal were higher on days when the person had run than on the next day, and higher the day after a run than on the days after that. Over the course of the day of a run, valence and arousal declined significantly as the time since the run increased. Physically fitter participants had more positive valence overall, and this was particularly true when they had not run recently. There was some evidence of higher-dose (i.e., longer and faster runs being associated with lower arousal on the next and subsequent days. Gender did not moderate associations between running and valence or arousal. Discussion Our study demonstrated the potential for studying the associations between affect and exercise in a way that is precise, undemanding for participants, and convenient for researchers, using technologies that participants already own and use.

Motion illusions in optical art presented for long durations are temporally distorted.

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Nather, Francisco Carlos; Mecca, Fernando Figueiredo; Bueno, José Lino Oliveira

2013-01-01

Static figurative images implying human body movements observed for shorter and longer durations affect the perception of time. This study examined whether images of static geometric shapes would affect the perception of time. Undergraduate participants observed two Optical Art paintings by Bridget Riley for 9 or 36 s (group G9 and G36, respectively). Paintings implying different intensities of movement (2.0 and 6.0 point stimuli) were randomly presented. The prospective paradigm in the reproduction method was used to record time estimations. Data analysis did not show time distortions in the G9 group. In the G36 group the paintings were differently perceived: that for the 2.0 point one are estimated to be shorter than that for the 6.0 point one. Also for G36, the 2.0 point painting was underestimated in comparison with the actual time of exposure. Motion illusions in static images affected time estimation according to the attention given to the complexity of movement by the observer, probably leading to changes in the storage velocity of internal clock pulses.

Prevalence and impact of short sleep duration in redeployed OIF soldiers.

Science.gov (United States)

Luxton, David D; Greenburg, David; Ryan, Jenny; Niven, Alexander; Wheeler, Gary; Mysliwiec, Vincent

2011-09-01

Short sleep duration (SSD) is common among deployed soldiers. The prevalence of SSD during redeployment, however, is unknown. Cross-sectional study of a brigade combat team (n = 3152 US Army soldiers) surveyed 90-180 days after completing a 6-15 month deployment to Iraq as part of Operation Iraqi Freedom (OIF). Survey items targeted sleep habits and comorbid medical conditions. Multivariate logistic regression analyses were performed to calculate adjusted odds ratios of medical comorbidities associated with SSD. US Army Infantry Post. All soldiers from a redeploying brigade combat team participated in a health assessment between 90 and 180 days upon return to Ft. Lewis from Iraq. None. A total of 2738 (86.9%) soldiers answered questions regarding self-perceived sleep and were included in the analysis. Mean sleep duration was 5.8 ± 1.2 hours. Nineteen hundred fifty-nine (72%) slept ≤ 6 h, but only 16% reported a daytime nap or felt their job performance was affected due to lack of sleep. Short sleep was more common among soldiers who reported combat exposure. After controlling for combat exposure, short sleep duration (SSD) was associated with symptoms of depression, posttraumatic stress disorder, panic syndrome, and with high-risk health behaviors such as abuse of tobacco and alcohol products, and suicide attempts. SSD is common among redeployed soldiers. Soldiers who experienced combat are at increased risk for persistent SSD and comorbidities associated with SSD. Efforts to reestablish good sleep habits and aggressive evaluation of soldiers with persistent SSD following deployment may aid in the prevention and management of associated medical conditions.

Economic impact of antidepressant treatment duration in naturalistic conditions.

Science.gov (United States)

Tournier, M; Crott, R; Gaudron, Y; Verdoux, H

2013-05-01

To assess the economic impact of the duration of antidepressant drug treatment in a real-life setting. A historical fixed cohort study included 27 917 patients aged 18 and over with a new antidepressant treatment registered in the national insurance database. The economic impact concerned healthcare expenditure in the first 3 months after treatment discontinuation. Generalized linear models were used to compare two groups of treatment duration: adjustment for care costs before and during treatment episode, gender, age, chronic diseases, welfare and prescriber specialty, total healthcare costs (in log) [-0.06 (-0.14;0.01) P = 0.11] and psychiatric care costs (in square root) [-0.08 (-0.41;0.25) P = 0.6] were similar in both groups. Non-psychiatric care costs were significantly lower in the 'long treatment duration' group compared with the 'short treatment duration' group [-11.4 (-15.8; -7.0) P costs over the antidepressant treatment episode were larger in the 'long treatment duration' group compared with the 'short treatment duration' group. With regard to healthcare costs and global health, antidepressant drug treatments of short duration appear less effective than treatment of recommended duration. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Globally coherent short duration magnetic field transients and their effect on ground based gravitational-wave detectors

International Nuclear Information System (INIS)

Kowalska-Leszczynska, Izabela; Bulik, Tomasz; Bizouard, Marie-Anne; Robinet, Florent; Christensen, Nelson; Rohde, Maximilian; Coughlin, Michael; Gołkowski, Mark; Kubisz, Jerzy; Kulak, Andrzej; Mlynarczyk, Janusz

2017-01-01

It has been recognized that the magnetic fields from the Schumann resonances could affect the search for a stochastic gravitational-wave background by LIGO and Virgo. Presented here are the observations of short duration magnetic field transients that are coincident in the magnetometers at the LIGO and Virgo sites. Data from low-noise magnetometers in Poland and Colorado, USA, are also used and show short duration magnetic transients of global extent. We measure at least 2.3 coincident (between Poland and Colorado) magnetic transient events per day where one of the pulses exceeds 200 pT. Given the recently measured values of the magnetic coupling to differential arm motion for Advanced LIGO, there would be a few events per day that would appear simultaneously at the gravitational-wave detector sites and could move the test masses of order 10 −18 m. We confirm that in the advanced detector era short duration transient gravitational-wave searches must account for correlated magnetic field noise in the global detector network. (paper)

Effect of smart phone using duration and gender on dynamic balance

Directory of Open Access Journals (Sweden)

Doaa Rafat El Azab

2017-01-01

Full Text Available Smart phones are constantly used for extended periods while looking at the visual display terminals this may causes musculoskeletal problems. So, the purpose of this study was to investigate effect of smart phone using duration and gender on dynamic balance. Subjects: Sixty normal subjects included in this study their age ranged from 20 years to 35 years were divided into three groups, A not using smart phone, B using smart phone less than 4 h per day, C using smart phone more than 4 h per day. Methods: Biodex Stability System was utilized to assess dynamic balance; 3 trials were performed from which the mean value was calculated. Results: there is a significant decrease in all balance directions for group B and C (using smart phone with favor reduction for group C (using smart phone more than 4 h per day and there is a significant difference between male and female subjects as dynamic balance decreased more in female subjects more than male subjects. Conclusion: Long duration of smart phone using affect negatively the balance ability especially in females, so we should develop preventive programs to alleviate its negative effects.

Storage temperature affects fruit quality attributes of Ber ( Ziziphus ...

African Journals Online (AJOL)

Fruit utilization is affected by quality attributes and shelf life. The quality of Jujube or Ber (Ziziphus mauritiana Lamk.) fruits after harvest depends on storage conditions used. In this study, different storage temperatures and durations were evaluated to determine the appropriate storage conditions of fresh fruits of Z.

High-voltage variable-duration pulse generator

International Nuclear Information System (INIS)

Anisimova, T.E.; Akkuratov, E.V.; Gromovenko, V.M.; Nikonov, Yu.P.; Malinin, A.N.

1988-01-01

A high-voltage generator is described that allows pulse duration tau to be varied within wide limits and has high efficiency (at least 50% for tau = 0.5 tau/sub max/) and an amplitude of up to 5 kV, a repetition frequency of up to 200 Hz,and a variable duration of 0-30 μsec. The generator is used in the controller of an electron accelerator

Duration of therapy – Does it matter?

DEFF Research Database (Denmark)

Kramer Schmidt, Lotte; Bojesen, Anders Bo; Nielsen, Anette Søgaard

2018-01-01

Background The recommendations in clinical guidelines for duration of therapy for alcohol use disorder (AUD) are based on consensus decisions. In reality, we do not know the optimal duration of an alcohol treatment course. Methods A systematic review and meta-regression of randomized controlled...... project in itself may influence outcome in studies of psychosocial treatment for alcohol use disorder....... across studies. Treatment outcome was defined as long-term alcohol use measured in percentage of days abstinent (PDA), percentage of heavy days drinking (PHD), and/or proportion of participants abstinent (ABS). Results 48 studies encompassing 8984 participants. Mean planned duration of therapy: 18 (8...

Physiological and Molecular Processes Associated with Long Duration of ABA Treatment

Directory of Open Access Journals (Sweden)

Mei Wang

2018-02-01

Full Text Available Plants need to respond to various environmental stresses such as abiotic stress for proper development and growth. The responses to abiotic stress can be biochemically demanding, resulting in a trade-off that negatively affects plant growth and development. Thus, plant stress responses must be fine-tuned depending on the stress severity and duration. Abscisic acid, a phytohormone, plays a key role in responses to abiotic stress. Here, we investigated time-dependent physiological and molecular responses to long-term ABA treatment in Arabidopsis as an approach to gain insight into the plant responses to long-term abiotic stress. Upon ABA treatment, the amount of cellular ABA increased to higher levels, reaching to a peak at 24 h after treatment (HAT, and then gradually decreased with time whereas ABA-GE was maintained at lower levels until 24 HAT and then abruptly increased to higher levels at 48 HAT followed by a gradual decline at later time points. Many genes involved in dehydration stress responses, ABA metabolism, chloroplast biogenesis, and chlorophyll degradation were strongly expressed at early time points with a peak at 24 or 48 HAT followed by gradual decreases in induction fold or even suppression at later time points. At the physiological level, long-term ABA treatment caused leaf yellowing, reduced chlorophyll levels, and inhibited chloroplast division in addition to the growth suppression whereas short-term ABA treatment did not affect chlorophyll levels. Our results indicate that the duration of ABA treatment is a crucial factor in determining the mode of ABA-mediated signaling and plant responses: active mobilization of cellular resources at early time points and suppressive responses at later time points.

The effects of duration of exposure to the REAPS model in developing students' general creativity and creative problem solving in science

Science.gov (United States)

Alhusaini, Abdulnasser Alashaal F.

The Real Engagement in Active Problem Solving (REAPS) model was developed in 2004 by C. June Maker and colleagues as an intervention for gifted students to develop creative problem solving ability through the use of real-world problems. The primary purpose of this study was to examine the effects of the REAPS model on developing students' general creativity and creative problem solving in science with two durations as independent variables. The long duration of the REAPS model implementation lasted five academic quarters or approximately 10 months; the short duration lasted two quarters or approximately four months. The dependent variables were students' general creativity and creative problem solving in science. The second purpose of the study was to explore which aspects of creative problem solving (i.e., generating ideas, generating different types of ideas, generating original ideas, adding details to ideas, generating ideas with social impact, finding problems, generating and elaborating on solutions, and classifying elements) were most affected by the long duration of the intervention. The REAPS model in conjunction with Amabile's (1983; 1996) model of creative performance provided the theoretical framework for this study. The study was conducted using data from the Project of Differentiation for Diverse Learners in Regular Classrooms (i.e., the Australian Project) in which one public elementary school in the eastern region of Australia cooperated with the DISCOVER research team at the University of Arizona. All students in the school from first to sixth grade participated in the study. The total sample was 360 students, of which 115 were exposed to a long duration and 245 to a short duration of the REAPS model. The principal investigators used a quasi-experimental research design in which all students in the school received the treatment for different durations. Students in both groups completed pre- and posttests using the Test of Creative Thinking

Effects of whole-body cryotherapy duration on thermal and cardio-vascular response.

Science.gov (United States)

Fonda, Borut; De Nardi, Massimo; Sarabon, Nejc

2014-05-01

Whole-body cryotherapy (WBC) is the exposure of minimally dressed participants to very cold air, either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. Practitioners are vague when it comes to recommendations on the duration of a single session. Recommended exposure for cryo-chamber is 150s, but no empirically based recommendations are available for a cryo-cabin. Therefore the aim of this study was to examine thermal and cardio-vascular responses after 90, 120, 150 and 180s of WBC in a cryo-cabin. Our hypothesis was that skin temperature would be significantly lower after longer exposers. Twelve male participants (age 23.9±4.2 years) completed four WBC of different durations (90, 120, 150 and 180s) in a cryo-cabin. Thermal response, heart rate and blood pressure were measured prior, immediately after, 5min after and 30min after the session. Skin temperature differed significantly among different durations, except between 150 and 180s. There was no significant difference in heart rate and blood pressure. Thermal discomfort during a single session displayed a linear increase throughout the whole session. Our results indicate that practitioners and clinicians using cryo-cabin for WBC do not need to perform sessions longer than 150s. We have shown that longer sessions do not substantially affect thermal and cardio-vascular response, but do increase thermal discomfort. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dog growls express various contextual and affective content for human listeners.

Science.gov (United States)

Faragó, T; Takács, N; Miklósi, Á; Pongrácz, P

2017-05-01

Vocal expressions of emotions follow simple rules to encode the inner state of the caller into acoustic parameters, not just within species, but also in cross-species communication. Humans use these structural rules to attribute emotions to dog vocalizations, especially to barks, which match with their contexts. In contrast, humans were found to be unable to differentiate between playful and threatening growls, probably because single growls' aggression level was assessed based on acoustic size cues. To resolve this contradiction, we played back natural growl bouts from three social contexts (food guarding, threatening and playing) to humans, who had to rate the emotional load and guess the context of the playbacks. Listeners attributed emotions to growls according to their social contexts. Within threatening and playful contexts, bouts with shorter, slower pulsing growls and showing smaller apparent body size were rated to be less aggressive and fearful, but more playful and happy. Participants associated the correct contexts with the growls above chance. Moreover, women and participants experienced with dogs scored higher in this task. Our results indicate that dogs may communicate honestly their size and inner state in a serious contest situation, while manipulatively in more uncertain defensive and playful contexts.

Factors predicting the duration of adrenal insufficiency in patients successfully treated for Cushing disease and nonmalignant primary adrenal Cushing syndrome.

Science.gov (United States)

Prete, Alessandro; Paragliola, Rosa Maria; Bottiglieri, Filomena; Rota, Carlo Antonio; Pontecorvi, Alfredo; Salvatori, Roberto; Corsello, Salvatore Maria

2017-03-01

Successful treatment of Cushing syndrome causes transient or permanent adrenal insufficiency deriving from endogenous hypercortisolism-induced hypothalamus-pituitary-adrenal-axis suppression. We analyzed pre-treatment factors potentially affecting the duration of adrenal insufficiency. We conducted a retrospective analysis on patients successfully treated for Cushing disease (15 patients) who underwent transsphenoidal surgery, and nonmalignant primary adrenal Cushing syndrome (31 patients) who underwent unilateral adrenalectomy, divided into patients with overt primary adrenal Cushing syndrome (14 patients) and subclinical primary adrenal Cushing syndrome (17 patients). Epidemiological data, medical history, and hormonal parameters depending on the etiology of hypercortisolism were collected and compared to the duration of adrenal insufficiency. The median duration of follow-up after surgery for Cushing disease and primary adrenal Cushing syndrome was 70 and 48 months, respectively. In the Cushing disease group, the median duration of adrenal insufficiency after transsphenoidal surgery was 15 months: younger age at diagnosis and longer duration of signs and symptoms of hypercortisolism before diagnosis and surgery were associated with longer duration of adrenal insufficiency. The median duration of adrenal insufficiency was 6 months for subclinical primary adrenal Cushing syndrome and 18.5 months for overt primary adrenal Cushing syndrome. The biochemical severity of hypercortisolism, the grade of hypothalamus-pituitary-adrenal-axis suppression, and treatment with ketoconazole before surgery accounted for longer duration of adrenal insufficiency. In patients with Cushing disease, younger age and delayed diagnosis and treatment predict longer need for glucocorticoid replacement therapy after successful transsphenoidal surgery. In patients with primary adrenal Cushing syndrome, the severity of hypercortisolism plays a primary role in influencing the duration of

The relationship between intensity and duration of physical activity and subjective well-being.

Science.gov (United States)

Wicker, Pamela; Frick, Bernd

2015-10-01

Previous research documented a positive effect of physical activity on subjective well-being (SWB). Yet, mainly broad activity measures (e.g. resulting from yes-no questions) were used and the effect of different participation intensities and durations has been largely neglected. The aim of this study is to examine the effect of physical activity on SWB by focusing on participation intensity and duration. Survey data from 28 European countries are used for the analysis (n = 22 971). Two regression models (Generalized Method of Moments) are estimated which analyze the effect of participation intensity and duration on SWB (measured by life satisfaction). Given the endogeneity of the participation measures, instrumental variables are used (sport opportunities, club membership, time spent sitting). The models also control for other factors that could affect SWB (e.g. age, occupation). The results for participation intensity show that the number of days people practised at moderate intensity in the week prior to the interview have a significant and positive effect on SWB, while the number of days with vigorous-intensity activity has a significant and negative impact. Similarly, the models for duration indicate that the minutes spent on moderate-intensity activity significantly add to SWB, while the minutes spent on vigorous-intensity activity significantly reduce the level of SWB. The findings challenge the World Health Organization's recommendation in the sense that activity at moderate and vigorous intensity is not interchangeable if the aim is to also improve SWB (and not only physical health). © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Analysis of the Swift Gamma-Ray Bursts duration

International Nuclear Information System (INIS)

Horvath, I.; Veres, P.; Balazs, L. G.; Kelemen, J.; Bagoly, Z.; Tusnady, G.

2008-01-01

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanalyze the durations and their distribution and also the classification of GRBs. Using The First BAT Catalog the maximum likelihood estimation was used to analyzed the duration distribution of GRBs. The three log-normal fit is significantly (99.54% probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2%).

Sociodemographic characteristics associated with frequency and duration of eating family meals: a cross-sectional analysis.

Science.gov (United States)

Skeer, Margie R; Yantsides, Konstantina E; Eliasziw, Misha; Tracy, Migdalia R; Carlton-Smith, Allison R; Spirito, Anthony

2016-01-01

Children who frequently eat family meals are less likely to develop risk- and behavior-related outcomes, such as substance misuse, sexual risk, and obesity. Few studies have examined sociodemographic characteristics associated with both meal frequency (i.e., number of meals) and duration (i.e., number of minutes spent at mealtimes). We examine the association between sociodemographics and family meal frequency and duration among a sample of 85 parents in a large New England city that was recruited through the public-school system. Additionally, we examined differences in family meals by race/ethnicity and parental nativity. Unadjusted ANOVA and adjusted ANCOVA models were used to assess the associations between sociodemographic characteristics and frequency and duration of meals. Sociodemographic characteristics were not significantly associated with the frequency of family meals; however, in the adjusted models, differences were associated with duration of meals. Parents who were born outside the U.S. spent an average of 135.0 min eating meals per day with their children compared to 76.2 for parents who were born in the U.S. ( p  meals (126.7 min) compared to parents who reported being married or partnered (84.4; p  = 0.02). Differences existed in meal duration by parental nativity and race/ethnicity, ranging from 63.7 min among multi-racial/other parents born in the U.S. to 182.8 min among black parents born outside the U.S. This study builds a foundation for focused research into the mechanisms of family meals. Future longitudinal epidemiologic research on family meals may help to delineate targets for prevention of maladaptive behaviors, which could affect family-based practices, interventions, and policies.

[Individual variability in the duration of the second phase of the mixed dentition].

Science.gov (United States)

Löhr, E

1994-02-01

With a collection of dental casts from a longitudinal study of 175 orthodontically untreated probands (100 children without and 75 children with premature loss of deciduous molars and/or canines) serving as a base, the duration of the second period of mixed dentition was determined to be in relation to the probands the period of time between the gingival emergence of the first permanent buccal tooth and the full eruption of the set of teeth. The second period of mixed dentition in boys without premature loss of deciduous molars and canines lasts on an average 3.6 +/- 1.1 years and in girls 3.8 +/- 1.0 years. In cases of premature loss of deciduous molars and/or canines, the period of dentition is distinctly longer than under normal development conditions. The outside parameters (boys: Xmin = 0.9 years, Xmax = 6.2 years; girls: Xmin = 2.6 years, Xmax = 8.6 years), reflect a high degree of variability. The duration of the second period of mixed dentition is significantly affected by "the point in time of inception" and by the criteria "morphologically intact support zones" and "premature loss of deciduous molars and/or canines". Even given such data, however, it is not possible to make a sufficiently reliable prediction on an individual basis of the duration of the dentition.

Metabolic syndrome, hypertension, and diabetes mellitus after gastric banding: the role of aging and of duration of obesity.

Science.gov (United States)

Pontiroli, Antonio E; Alberto, Morabito; Paganelli, Michele; Saibene, Alessandro; Busetto, Luca

2013-01-01