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1.
Several studies demonstrate the importance of essential fatty acids (EFAs), and the long chain polyunsaturated FA docosahexaenoic acid (DHA), on cognition and brain development. The objective of this study was to investigate the relationship between whole-blood FAs and executive function in children from Northern Ghana. A total of 307, 2-to-6-year-old children attempted the dimensional change card sort (DCCS) task to assess executive function, and dried blood spot samples were collected and analyzed for FA content. Significant differences in mean % total whole-blood fatty acids were observed between children who could not follow directions on the DCCS test (49.8% of the sample) and those who could (50.2% of the sample). Positive associations with DCCS performance were observed for DHA (β=0.25, P=.06), total n-3 (β=0.17, P=.06) and dihomo-gamma-linolenic acid (DGLA; β=0.60, P=.06). Children with the highest levels of total n-3 and DHA were three and four times, respectively, more likely to pass at least one condition of the DCCS test of executive function than those with the lowest DHA levels. The results of this study indicate an association between n-3 FAs and high-level cognitive processes in children two to six years of age, providing impetus for further studies into possible interventions to improve EFA status of children in developing countries.  相似文献   

2.
Our previous work demonstrated that abacus-based mental calculation (AMC), a traditional Chinese calculation method, could help children improve their math abilities (e.g. basic arithmetical ability) and executive function (e.g. working memory). This study further examined the effects of long-term AMC training on math ability in visual-spatial domain and the task switching component of executive function. More importantly, this study investigated whether AMC training modulated the relationship between math abilities and task switching. The participants were seventy 7-year-old children who were randomly assigned into AMC and control groups at primary school entry. Children in AMC group received 2-hour AMC training every week since primary school entry. On the contrary, children in the control group had never received any AMC training. Math and task switching abilities were measured one year and three years respectively after AMC training began. The results showed that AMC children performed better than their peers on math abilities in arithmetical and visual-spatial domains. In addition, AMC group responded faster than control group in the switching task, while no group difference was found in switch cost. Most interestingly, group difference was present in the relationships between math abilities and switch cost. These results implied the effect of AMC training on math abilities as well as its relationship with executive function.  相似文献   

3.
The aim of the study was to assess the duration and quality of sleep of prepubertal (Tanner Scale level 1) physically and mentally healthy children as a function of school schedule (4 versus 4.5 days per week), age and grade (median age of 9.5 years for 4th grade versus median age of 10.5 years for 5th grade), school district (wealthy versus nonwealthy) in Paris, France, and parental socioeconomic status (high, medium, or low). We studied 51 girl and 44 boy volunteer pupils with written parental consent. The study lasted 2 weeks during the month of March. During the first study week, the children attended school 4.5 days, and during the second week, they attended school only 4 days without difference in the length of the school day. A sleep log was used to ascertain time of lights off for sleep and lights on at awakening, nighttime sleep duration, and self-rated sleep quality. A visual analog scale (VAS) was also used by pupils to self-rate the level of perceived sleepiness at four specific times of the school day. Conventional statistical methods (e.g., t and chi2 tests) were used to examine differences in mean values. Sleep duration, self-rated sleepiness, and subjective sleep quality were comparable (P > .05) by gender, school schedule, school district, and parental socioeconomic status. Overall, the sleep of this sample of Parisian children around 10 years of age was rather stable in its duration and timing, suggesting flexibility to adjust to the different school schedules.  相似文献   

4.
To utilize the rat spinotrapezius muscle as a model to investigate the microcirculatory consequences of exercise training, it is necessary to design an exercise protocol that recruits this muscle. There is evidence that the spinotrapezius is derecruited during standard treadmill exercise protocols performed on the uphill treadmill (i.e., 6 degrees incline). This investigation tested the hypothesis that downhill running would effectively recruit the spinotrapezius muscle as assessed by the presence of an exercise hyperemia response. We used radioactive 15-microm microspheres to determine blood flows in the spinotrapezius and selected hindlimb muscles of female Sprague-Dawley rats at rest and during downhill (i.e., -14 degrees incline; 331 +/- 5 g body wt, n = 7) and level (i.e., 0 degrees incline; 320 +/- 11 g body wt, n = 5) running at 30 m/min. Both level and downhill exercise increased blood flow to all hindlimb muscles (P < 0.01). However, in marked contrast to the absence of a hyperemic response to level running, blood flow to the spinotrapezius muscle increased from 26 +/- 6 ml.min(-1).100 g(-1) at rest to 69 +/- 8 ml.min(-1).100 g(-1) during downhill running (P < 0.01). These findings indicate that downhill running represents an exercise paradigm that recruits the spinotrapezius muscle and thereby constitutes a tenable physiological model for investigating the adaptations induced by exercise training (i.e., the mechanisms of altered microcirculatory control by transmission light microscopy).  相似文献   

5.
We studied fatigue of rat diaphragm in response to repetitive brief and prolonged electrical stimulation of the phrenic nerve, at 0.2, 1-100 Hz. Low and high frequency of stimulation produced twitch and tetanic contractions in the rat diaphragm. A mean maximum twitch tension of 1.4 +/- 0.1 g was produced at 1 Hz, and a mean maximum tetanic tension of 5.6 +/- 0.3 g was obtained at 100 Hz (means +/- S.E., n = 8). Twitch and tetanic fatigue was produced at all frequencies of stimulations, but with different time scale, or duration, and with different number of stimuli delivered to the muscle. At low rates of stimulation, e.g. 10 Hz, fewer stimuli were needed to fatigue the muscle (3000 in 5 min), whereas at high rates of stimulation, e.g. 50 Hz, more stimuli were needed to fatigue the muscle (6600 in 2.2 min). The amplitude of the tetanic tensions elicited at 10 and 50 Hz, at the end of 5 or 2 min fatiguing stimulation, was 39 +/- 2.7% and 80 +/- 3.1% of their respective control tensions (2.8 +/- 0 2 g and 5.3 +/- 0.5 g, n = 8, P 0.001). It was concluded that fatigue in the rat diaphragm depended on the frequency and duration of stimulation as well as on the number of stimuli delivered to the muscle. Various mechanisms of muscle fatigue are described in the discussion to explain the observations made in the present investigation.  相似文献   

6.
《Chronobiology international》2013,30(6):1005-1017
The aim of the study was to assess the duration and quality of sleep of prepubertal (Tanner Scale level 1) physically and mentally healthy children as a function of school schedule (4 versus 4.5 days per week), age and grade (median age of 9.5 years for 4th grade versus median age of 10.5 years for 5th grade), school district (wealthy versus nonwealthy) in Paris, France, and parental socioeconomic status (high, medium, or low). We studied 51 girl and 44 boy volunteer pupils with written parental consent. The study lasted 2 weeks during the month of March. During the first study week, the children attended school 4.5 days, and during the second week, they attended school only 4 days without difference in the length of the school day. A sleep log was used to ascertain time of lights off for sleep and lights on at awakening, nighttime sleep duration, and self-rated sleep quality. A visual analog scale (VAS) was also used by pupils to self-rate the level of perceived sleepiness at four specific times of the school day. Conventional statistical methods (e.g., t and χ2tests) were used to examine differences in mean values. Sleep duration, self-rated sleepiness, and subjective sleep quality were comparable (P >. 05) by gender, school schedule, school district, and parental socioeconomic status. Overall, the sleep of this sample of Parisian children around 10 years of age was rather stable in its duration and timing, suggesting flexibility to adjust to the different school schedules. (Chronobiology International, 18 (6), 1005–1017, 2001)  相似文献   

7.
Complications of systemic corticosteroid therapy for problematic hemangioma.   总被引:13,自引:0,他引:13  
Systemic corticosteroid therapy has been used to treat hemangiomas for 30 years; yet, there are no studies of possible complications. We reviewed the database of the Vascular Anomalies Center at the Boston Children's Hospital and gathered information on short- and long-term side effects in children who were given systemic corticosteroids for problematic hemangiomas. In addition, a questionnaire regarding early and late consequences was sent to the families of children who were treated with corticosteroids from 1983 to 1997. Of 300 patients with hemangiomas, 80 children were identified as having received a full course of systemic corticosteroids for problematic tumors. Complete data were collected on 62 of these children. The response rate to the questionnaire was 78 percent (n = 62 of 80). The initial dose of corticosteroid varied from 2 to 3 mg/kg/ day. Duration of therapy ranged from 2 to 21 months (mean, 7.9 months; median, 6.5 months). The follow-up interval from the cessation of therapy ranged from 6 months to 15 years (mean, 4 years; median, 3 years). Short-term complications included cushingoid facies (n = 44; 71 percent), personality changes (n = 18; 29 percent), gastric irritation (n = 13; 21 percent), fungal (oral or perineal) infection (n = 4; 6 percent), and diminished gain of height (n = 22; 35 percent) and weight (n = 26; 42 percent). A total of 91 percent of children who had diminished gain of height (n = 20) returned to their pretreatment growth curve for height by 24 months of age. One child, who was treated at another institution with a dose of 20 mg/kg/day for 6.5 months that was slowly tapered over 18 months, was petite 6 years after ending therapy. Another child treated with an initial dose of 2 mg/kg/day for 5 months was smaller than predicted at the age of 6 years, but she was born prematurely and was on ventilatory support for respiratory distress. Three children treated with the standard dose and duration were at a low percentile for weight 4, 5, and 10 years after the cessation of therapy. Statistical analysis showed a correlation between diminished gain of height with duration of therapy and age at initiation of treatment. One child had corticosteroid myopathy that resolved with cessation of therapy. We found no evidence for immunologic suppression, i.e., there was no increase in the number of bacterial infections during corticosteroid administration. In conclusion, systemic corticosteroids can be safely given to treat endangering hemangiomas in infants at doses of 2 to 3 mg/kg/day, which are slowly tapered and stopped before the age of 1 year. Short-term side effects were minor and transient, and no serious long-term complications occurred.  相似文献   

8.
BackgroundRoad traffic noise is a prevalent and known health hazard. However, little is known yet about its effect on children’s cognition. We aimed to study the association between exposure to road traffic noise and the development of working memory and attention in primary school children, considering school-outdoor and school-indoor annual average noise levels and noise fluctuation characteristics, as well as home-outdoor noise exposure.Methods and findingsWe followed up a population-based sample of 2,680 children aged 7 to 10 years from 38 schools in Barcelona (Catalonia, Spain) between January 2012 to March 2013. Children underwent computerised cognitive tests 4 times (n = 10,112), for working memory (2-back task, detectability), complex working memory (3-back task, detectability), and inattentiveness (Attention Network Task, hit reaction time standard error, in milliseconds). Road traffic noise was measured indoors and outdoors at schools, at the start of the school year, using standard protocols to obtain A-weighted equivalent sound pressure levels, i.e., annual average levels scaled to human hearing, for the daytime (daytime LAeq, in dB). We also derived fluctuation indicators out of the measurements (noise intermittency ratio, %; and number of noise events) and obtained individual estimated indoor noise levels (LAeq) correcting for classroom orientation and classroom change between years. Home-outdoor noise exposure at home (Lden, i.e., EU indicator for the 24-hour annual average levels) was estimated using Barcelona’s noise map for year 2012, according to the European Noise Directive (2002). We used linear mixed models to evaluate the association between exposure to noise and cognitive development adjusting for age, sex, maternal education, socioeconomical vulnerability index at home, indoor or outdoor traffic-related air pollution (TRAP) for corresponding school models or outdoor nitrogen dioxide (NO2) for home models. Child and school were included as nested random effects.The median age (percentile 25, percentile 75) of children in visit 1 was 8.5 (7.8; 9.3) years, 49.9% were girls, and 50% of the schools were public. School-outdoor exposure to road traffic noise was associated with a slower development in working memory (2-back and 3-back) and greater inattentiveness over 1 year in children, both for the average noise level (e.g., ‒4.83 points [95% CI: ‒7.21, ‒2.45], p-value < 0.001, in 2-back detectability per 5 dB in street levels) and noise fluctuation (e.g., ‒4.38 [‒7.08, ‒1.67], p-value = 0.002, per 50 noise events at street level). Individual exposure to the road traffic average noise level in classrooms was only associated with inattentiveness (2.49 ms [0, 4.81], p-value = 0.050, per 5 dB), whereas indoor noise fluctuation was consistently associated with all outcomes. Home-outdoor noise exposure was not associated with the outcomes. Study limitations include a potential lack of generalizability (58% of mothers with university degree in our study versus 50% in the region) and the lack of past noise exposure assessment.ConclusionsWe observed that exposure to road traffic noise at school, but not at home, was associated with slower development of working memory, complex working memory, and attention in schoolchildren over 1 year. Associations with noise fluctuation indicators were more evident than with average noise levels in classrooms.

In a cohort study, Maria Foraster and colleagues study associations between exposure to road traffic noise at schools, and trajectories of working memory and inattentiveness among schoolchildren aged 7 to 10 years in Barcelona, Spain.  相似文献   

9.

Aims

To assess the cognitive and behavioral aspects of executive functioning (EF) and learning skills in extremely preterm (EPT) children compared with term control children aged 10 to 15 years.

Methods

A total of 132 of 134 (98% of all eligible survivors) EPT children born at the 2 Swedish regional tertiary care centers from 1992 to 1998 (mean age = 12 years, mean birth weight = 718 g, and mean gestational age = 24.4 weeks) and 103 matched term controls were assessed. General intelligence was assessed using the Wechsler Intelligence Scale for Children (WISC-III-R), and cognitive aspects of EF were analyzed using EF-sensitive subscales of the WISC-III-R and Tower test of the Delis-Kaplan Executive Function Scale (D-KEFS). Behaviors related to EF and learning skills were assessed using the Five to Fifteen questionnaire, which is a validated parent and teacher instrument. Academic performance in school was assessed by teachers’ responses on Achenbach’s Teachers Report Form. Analyses performed included multivariate analyses of covariance (ANCOVA and MANCOVA) and logistic regression analyses.

Results

The EPT children displayed significant deficits in cognitive aspects of EF compared with the controls, exhibiting decreases on the order of 0.9 SD to 1.2 SD for tasks of verbal conceptual reasoning, verbal and non-verbal working memory, processing speed and planning ability (P <0.001 for all). After excluding the children with major neurosensory impairment (NSI) or a Full Scale intelligence quotient (FSIQ) of < 70, significant differences were observed on all tests. Compared with controls, parents and teachers of EPT children reported significantly more EF-related behavioral problems. MANCOVA of teacher-reported learning skills in children with FSIQ >70 and without major NSI revealed no interactions, but significant main effects were observed for the behavioral composite executive function score, group status (EPT vs control) and FSIQ, for which all effect sizes were medium to large. The corresponding findings of MANCOVA of the parent-reported learning skills were very similar. According to the teachers’ ratings, the EPT children were less well adjusted to the school environment.

Conclusion

EPT children born in the 1990s who received active perinatal care are at an increased risk of executive dysfunction, even after excluding children with significant neurodevelopmental disabilities. Even mild to moderate executive dysfunctions has a significant impact on learning skills. These findings suggest the need for timely interventions that address specific cognitive vulnerabilities and executive dysfunctions.  相似文献   

10.
Imprecise or biased density estimates can lead to inadequate conservation action, overexploitation of game species, or lost recreational opportunities. Common approaches to estimating density of avian populations often either ignore the probability that an individual is present within the sampling area but is not available to be sampled (e.g., not vocalizing), or do not consider covariates that could influence availability. Additionally, management decisions made at the management unit scale are often informed by inadequate monitoring practices, such as limited sampling intensity. In such cases, management agencies calculate density by applying correction factors (e.g., detection probabilities estimated using empirical data from a different study system) to count data, rather than estimating a detection function directly using statistical models. We conducted a simulation study using northern bobwhite (Colinus virginianus; bobwhite) as a model species to quantify the consequences of mis-specifying avian point count models on bias and precision of density estimates. We compared bias and precision of estimates from a fully specified distance-sampling model that estimates availability and detection to 4 different mis-specified approaches, including 2 approaches to calculating density using correction factors. Using correction factors to calculate density produced estimates with low bias but relatively lower precision compared to the fully specified model (CV of density estimates at 35 sites over 5 years: fully specified = 10%, correction factors = 25% and 30%). Although the mean precision and bias of the fully specified model improved with more data (70 sites over 5 years, CV = 9%; 35 sites over 10 years, CV = 9%), precision of correction factors did not (70 sites over 5 years, CV = 22% and 27%; 35 sites over 10 years, CV = 24% and 29%). The fully specified model captured the underlying temporal variation in detection and availability. Increasing sampling duration from 5 to 10 years improved modeled estimates of growth rate, even for mis-specified models, but not derived growth rates using pre-determined detection functions. We demonstrated that conducting point counts 3 times/year at a feasible number of sites can produce relatively unbiased estimates of bobwhite density. Pre-determined detection functions can be fortuitously unbiased for certain years, but they are not a reliable method for determining density or identifying trends in density over time. © 2020 The Wildlife Society.  相似文献   

11.

Background and Aims

Excessive alcohol use is assumed to affect maturation of cognitive functioning in adolescence. However, most existing studies that have tested this hypothesis are seriously flawed due to the use of selective groups and/or cross-sectional designs, which limits the ability to draw firm conclusions. This longitudinal study investigated whether patterns of alcohol use predicted differences in maturation of executive functioning in adolescence. Additionally, gender was tested as a possible moderator.

Methods

We used data from the Tracking Adolescents’ Individual Lives Survey (TRAILS), which comprises a cohort of 2,230 Dutch adolescents. Maturation of executive functioning was measured by assessing the standardized improvement on each of four basic executive functions (i.e., inhibition, working memory, and shift- and sustained attention) between ages 11 and 19. Participants were assigned to one of six (heavy) drinking groups (i.e., non-drinkers, light drinkers, infrequent heavy drinkers, increased heavy drinkers, decreased heavy drinkers, and chronic heavy drinkers). We conducted linear regression analyses, and adjusted for relevant confounders.

Results

The six drinking groups did not reveal significant differences in maturation between drinking groups. E.g., maturation executive functioning of chronic heavy drinkers in comparison to non-drinkers; inhibition: B = -0.14, 95% CI [-0.41 to 0.14], working memory: B = -0.03, 95% CI [-0.26 to 0.21], shift attention: B = 0.13, 95% CI [-0.17 to 0.41], sustained attention: B = 0.12, 95% CI [-0.60 to 0.36]. Furthermore, gender was not found to be a significant moderator.

Conclusions

Four years of weekly heavy drinking (i.e., chronic heavy drinkers) did not result in measurable impairments in four basic executive functions. Thus, regular heavy drinking in adolescence does not seem to affect these basic behavioural measures of executive functioning.  相似文献   

12.
The purpose of this experiment was to investigate 5- and 8-year-olds' long-term memory for stimulus duration in a bisection task. Children were trained to discriminate between a short and a long standard duration presented as visual stimulus for 2 and 8 s, respectively. They had then to decide whether an intermediate stimulus duration was more similar to the short or to the long standard in two identical testing phases separated by an interfering task lasting for 15 min (immediate test vs. deferred test). The results showed that the 5- and the 8-year-olds produced orderly psychophysical functions. However, the 8-year-olds produced psychophysical functions, which increased more abruptly with the increasing stimulus duration. Nevertheless, whatever the age of children tested, the psychophysical function curves were flatter in the deferred test than in the immediate test, and more particularly in the 5-year-olds. Furthermore, the 5-year-olds produced fewer 'long' responses in the deferred than in the immediate test. Modeling of the data suggests that the variability of the representation of the standard in long-term memory was higher in the 5- than in the 8-year-olds and that the interfering task increased this memory variability.  相似文献   

13.
Although amnestic mild cognitive impairment (aMCI; often considered a prodromal phase of Alzheimer’s disease, AD) is most recognized by its implications for decline in memory function, research suggests that deficits in attention are present early in aMCI and may be predictive of progression to AD. The present study used functional magnetic resonance imaging to examine differences in the brain during the attention network test between 8 individuals with aMCI and 8 neurologically healthy, demographically matched controls. While there were no significant behavioral differences between groups for the alerting and orienting functions, patients with aMCI showed more activity in neural regions typically associated with the networks subserving these functions (e.g., temporoparietal junction and posterior parietal regions, respectively). More importantly, there were both behavioral (i.e., greater conflict effect) and corresponding neural deficits in executive control (e.g., less activation in the prefrontal and anterior cingulate cortices). Although based on a small number of patients, our findings suggest that deficits of attention, especially the executive control of attention, may significantly contribute to the behavioral and cognitive deficits of aMCI.  相似文献   

14.
A performance-based measure for assessing executive functions (EF) is useful to understand patients’ real life performance of EF. This study aimed to develop a performance-based measure of executive functions (PEF) based on the Lezak model and to examine psychometric properties (i.e., unidimensionality and reliability) of the PEF using Rasch analysis in patients with schizophrenia. We developed the PEF in three phases: (1) designing the preliminary version of PEF; (2) consultation with experts, cognitive interviews with patients, and pilot tests on patients to revise the preliminary PEF; (3) establishment of the final version of the PEF and examination of unidimensionality and Rasch reliability. Two hundred patients were assessed using the revised PEF. After deleting items which did not satisfy the Rasch model’s expectations, the final version of the PEF contained 1 practice item and 13 test items for assessing the four domains of EF (i.e., volition, planning, purposive action, and effective performance). For unidimensional and multidimensional Rasch analyses, the 4 domains showed good reliability (i.e., 0.77–0.85 and 0.87–0.90, respectively). Our results showed that the PEF had satisfactory unidimensionality and Rasch reliability. Therefore, clinicians and researchers could use the PEF to assess the four domains of EF in patients with schizophrenia.  相似文献   

15.
The effect of electromagnetic stimulation on nerve conduction and on muscle contraction was studied in isolated frog sciatic nerve-gastrocnemius muscle preparation. The nerve trunk was passed through an induction copper coil and current was induced from a d.c. source 1.5-4 V at a frequency of 100 min-1, for 20-120 s duration, via an operating switch. Normal indirectly-elicited twitch (0.5 Hz with 0.6 V, supramaximal, and 1 ms pulse duration) tension was elicited, repetitively, and this was interrupted by magnetic induction. Inhibition of the twitch tension was taken as a measure of conduction block. The results showed that magnetic stimulation inhibited or blocked the twitch contractions (control 3.2 +/- 0.1 g, tension, mean +/- s.e., n = 8), in 4-5 min, and hence it blocked nerve conduction in this preparation. Recovery was achieved within 4-5 min, after washing out the preparation in Ringer solution. The mechanism of inhibition was interpreted in terms of an interference with ionic fluxes across the cell membrane. A comparison of electrical and magnetic stimulation was made and this was related to their clinical and experimental implications.  相似文献   

16.
OBJECTIVE--To evaluate the long term outcome of renal function in infants and children after diarrhoea associated haemolytic uraemic syndrome. SETTING--The Hospital for Sick Children, Great Ormond Street, and the Royal Free Hospital, London. SUBJECTS--103 children with the syndrome who presented between 1966 and 1985; 88 attended for follow up investigations (40 male, 48 female) with a mean age 11.6 (range 5.2-22.6) years and a mean duration of follow up of 8.5 (range 5.1-21.3) years. MAIN OUTCOME MEASURES--Blood pressure, ratio of early morning urine albumin to creatinine concentration, glomerular filtration rate, and plasma renin activity. RESULTS--The mean (SD) systolic blood pressure standard deviation score was 0.38 (0.67) and diastolic blood pressure SD score was 0.10 (0.76). The geometric mean ratio of overnight urine albumin to creatinine concentration was 1.27 (range 0.03-48.2), significantly higher than the value observed in 77 normal children (0.32 (0.05-1.95), p less than 0.0001). Glomerular filtration rate estimated from the plasma clearance of chromium-51 EDTA was 95.1 (22.7) ml/min/1.73 m2 surface area, and 16 children had a rate of less than or equal to 80 ml/min/1.73 m2. Significant negative correlations were found between glomerular filtration rate and urinary albumin to creatinine ratio (r = -0.41, p less than 0.0001) and glomerular filtration rate and systolic blood pressure SD score (r = -0.48, p less than 0.0001). A significant positive correlation was found between urinary albumin to creatinine ratio and systolic blood pressure SD score (r = 0.25, p = 0.02). CONCLUSIONS--After an acute episode of diarrhoea associated haemolytic uraemic syndrome 31% (27/88) of children had an increased albumin excretion, 18% (16/88) had a reduced glomerular filtration rate and 10% (9/88) had both, in association with a higher systolic blood pressure, indicating considerable residual nephropathy in this group.  相似文献   

17.
The purpose of this study was to compare 4 interval training (IT) sessions with different intensities and durations of exercise to determine the effect on mean VO?, total VO?, and duration of exertion ≥95% maximum power output (MPO), and the effects on biomarkers of fatigue such as blood-lactate concentration (BLC) and rating of perceived exertion. The subjects were 12 recreationally competitive male (n = 7, mean ± SD age = 26.2 ± 3.9 years) and female (n = 5, mean ± SD age = 27.6 ± 4.3 years) triathletes. These subjects performed 4 IT sessions on a cycle ergometer varying in intensity (90 and 100% MPO) and duration of exercise (30 seconds and 3 minutes). This study revealed that IT using 30-second duration intervals (30-30 seconds) allows the athlete to perform a longer session, with a higher total and mean VO? HR and lower BLC than 3-minute durations. Similarly, submaximal exertion at 90% of MPO also allows performing longer sessions with a higher total VO? than 100% intensity. Thus, the results of the present study suggested that to increase the total time at high intensity of exercise and total VO? of a single exercise session performed by the athlete, IT protocols of short durations (i.e., 30 seconds) and submaximal intensities (i.e., 90% MPO) should be selected. Furthermore, performing short-duration intervals may allow the athlete to complete a longer IT session with greater metabolic demands (VO?) and lower BLC than longer (i.e., 3 minutes) intervals.  相似文献   

18.
The present study describes the development and initial validation of a new obesity‐specific, self‐report measure of health‐related quality of life (HRQOL) for children aged 5–13 years. Participants included 141 obese children (mean age = 9.2 years, 67% female, 55% black, mean zBMI = 2.52) and their primary caregivers. Children completed Sizing Me Up (obesity‐specific HRQOL) and the PedsQL (generic HRQOL). Item content for Sizing Me Up was based on the published child obesity and HRQOL literatures and expert opinion. Items use phrasing to orient children to respond to questions in context of his/her size (e.g., “were teased by other kids because of your size”). Caregivers completed Sizing Them Up, a parallel parent‐proxy, obesity‐specific HRQOL measure. Initial psychometric evaluation of Sizing Me Up was completed by conducting a factor analysis and determining internal consistency, test–retest reliability, and convergent and construct validity. Sizing Me Up is a 22‐item measure with five scales (i.e., Emotional Functioning, Physical Functioning, Social Avoidance, Positive Social Attributes, and Teasing/Marginalization) that account for 57% of the variance and a total HRQOL score. Internal consistency coefficients range from 0.68 to 0.85. Test–retest reliabilities range from 0.53 to 0.78. Good convergent validity was demonstrated with the PedsQL (rs = 0.35–0.65) and the parent‐proxy Sizing Them Up (rs = 0.22–0.44). Sizing Me Up represents the first obesity‐specific HRQOL measure developed specifically for younger school‐aged children (aged 5–13 years) with preliminary evidence of strong psychometric properties that likely has both clinical and research utility in a variety of settings.  相似文献   

19.
The aim of this study was to evaluate the contribution of insulin processing to the improved meal-related B-cell function previously shown with the DPP-4 inhibitor vildagliptin. Fifty-five patients with type 2 diabetes (56.5+/-1.5 years; BMI=29.6+/-0.5 kg/m(2); FPG=9.9+/-0.2 mmol/l; HbA1c=7.7+/-0.1 %) were studied: 29 patients were treated with vildagliptin and 26 patients with placebo, both added to an ongoing metformin regimen (1.5-3.0 g/day). A standardized breakfast was given at baseline and after 52 weeks of treatment, and proinsulin related to insulin secretion was measured with C-peptide in the fasting and postprandial (over 4 h post-meal) states to evaluate B-cell function. The between-treatment difference (vildagliptin-placebo) in mean change from baseline in fasting proinsulin to C-peptide ratio (fastP/C) was -0.007+/-0.009 (p=0.052). Following the standard breakfast, 52 weeks of treatment with vildagliptin significantly decreased the dynamic proinsulin to C-peptide ratio (dynP/C) relative to placebo by 0.010+/-0.008 (p=0.037). Importantly, when the P/C was expressed in relation to the glucose stimulus (i.e., the fasting glucose and glucose AUC(0-240 min), respectively), the P/C relative to glucose was significantly reduced with vildagliptin vs. placebo, both in the fasting state (p=0.023) and postprandially (p=0.004). In conclusion, a more efficient B-cell insulin processing provides further evidence that vildagliptin treatment ameliorates abnormal B-cell function in patients with type 2 diabetes.  相似文献   

20.
Adoptive children are at increased risk for problematic behaviors but the origin of these individual differences in neurobehavioral function is unclear. This investigation examined whether adopted children with prenatal exposure to a wide variety of recreational drugs exhibited higher scores (i.e. more problems) with executive function and psychiatric symptomology. Caregivers of children ages 5 to 18 completed an online survey with items about use of alcohol, nicotine, or methamphetamine during pregnancy followed by the Behavior Rating Inventory of Executive Function (BRIEF, N = 437 including 59 adoptive parents) or the Child Behavior Checklist (CBCL, N = 549 including 54 adoptive parents). Relative to a comparison group of children raised by their biological parents, adoptive children that were polysubstance exposed during prenatal development exhibited higher rates of academic difficulties and were behind their classmates in math and reading. Adoptive children had statistically and clinically significant higher BRIEF ratings and this pattern was similar for boys and girls. CBCL ratings were significantly increased in adoptive children, particularly for Externalizing and Attention problems. Adoptive children with a history of polysubstance exposures including alcohol, nicotine, and methamphetamine are at heightened risk for difficulties with executive function as well as various psychopathologies. These findings suggest that increased monitoring to identify and implement remediation strategies may be warranted for adopted children with a history of in utero drug exposures.  相似文献   

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