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891.
Reading and spelling errors of vowels are reported in many studies (Bryson and Werker 1989; Fowler, Liberman, and Shankweiler
1977; Fowler, Shankweiler, and Liberman 1979; Goswami 1993; Landerl, Wimmer, and Frith 1997; Shankweiler and Liberman 1972).
The present study tested the hypothesis that spelling errors involving vowels are linked to difficulties in vowel perception.
Second to fourth graders (total n=155) were divided into five groups according to reading skill and were tested on a variety of measures involving vowel identification,
vowel discrimination, and vowel spelling. Despite little difficulty on the vowel discrimination tasks, participants made many
errors on the vowel identification measures. Vowel identification errors were linearly associated with reading skill with
least skilled readers having significantly more difficulty with stressed “short” vowels as in dip than with stressed “long” vowels as in deep, presented in identical contexts. Vowel identification errors were also associated with vowel spelling errors. It is hypothesized
that errors in vowel spelling may relate to weak access to the phoneme at the oral language level and may indicate a lack
of constancy in the representation of vowels by less skilled readers. Weaknesses in vowel perception can be detected with
a simple vowel identification test in which phonological similarity of test items is used as linguistic manipulation, and
where phonemes must be identified based on presentation of a single test item in a forced choice format. 相似文献
892.
893.
894.
Acute and residual effects of vibratory stimulation on explosive strength in elite and amateur athletes. 总被引:13,自引:0,他引:13
Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion. The athletes performed two separate series of three sets of exercises in random order. The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m x s(-2) transmitted through the two-arms handle to the arm muscles. The mechanical power of each repetition was measured by the 'Power Teach' instrument. The maximal and mean power values for each set were automatically recorded and shown on the screen. The acute effect was evaluated as the difference between the mean and peak power output in the second (with vibratory stimulation) and first (without vibratory stimulation) sets. Similarly, the residual effect was taken to be the difference between the power values of the third (after vibratory stimulation) and the first (before vibratory stimulation) sets. The results were subjected to a repeated-measures analysis of variance with group as a between-participants factor. The results showed that exercise mode (with vs without vibratory stimulation) resulted in a significant immediate effect for mean power and for maximal power. The factor group (elite vs amateurs) resulted in a significant effect for maximal power only. The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W (10.4% and 10.2%) for maximal and mean power respectively in the elite group, and 20.0 and 25.9 W (7.9% and 10.7%) respectively in the amateur athletes. Vibratory stimulation resulted in an insignificant residual effect. 相似文献
895.
Rita Christopher S. V. Suresh Babu L. Nirmala G. R. Rangaswamy C. P. Narayan K. Taranath Shetty 《Indian journal of clinical biochemistry : IJCB》1999,14(2):198-206
Maple Syrup Urine Disease is an autosomal recessive disorder caused by a deficiency in the activity of the branched-chain
α-ketoacid dehydrogenase complex. This rare disorder represents one of the causes of acute neonatal illness which results
in devastating disturbances of neurological development. On investigation of 1750 infants with neurological impairment for
inborn errors of amino acid metabolism, 4 neonates with classical maple syrup urine disease were detected. These otherwise
normal neonates presented in the first week after birth with seizures, lethargy and refusal of feeds, hypoglycemia and metabolic
acidosis. The plasma and urine concentrations of the branched-chain amino acids were increased and there was ketoaciduria.
Two of these neonates expired before specific treatment could be instituted. Routine biochemical screening of neonates with
acute illness could unearth many cases of this rare inherited metabolic disease. 相似文献
896.
Pedro Ángel Latorre Román Fernando Redondo Balboa Juan Párraga Montilla Víctor Manuel Soto Hermoso Pedro José Consuegra González Felipe García Pinillos 《Journal of sports sciences》2019,37(5):477-483
The purpose of this study was to determine the foot strike patterns (FSP), rearfoot position at initial contact (RPic, i.e., No INV/EVE) and foot rotation in children in relation to age. A total of 932 children aged 3 to 16 years participated in this study. A sagittal and frontal-plane video was recorded using a high-speed camcorder to analyse these variables. There is a significant increase (p < 0.001) of rearfoot strike patterns (RFS) prevalence in relation to age; e.g. preschool children (3–6 years old) displayed an RFS prevalence 46.65% and the adolescent population(15–16 years old) an RFS prevalence 92.20%. The total RFS prevalence in all samples was 69.25%. There was a significant reduction (p < 0.001) of prevalence of RPic in relation to age groups; preschool children displayed a prevalence of RPic 60.37% and the adolescent population 10%. There was a significant reduction (p < 0.001) of prevalence of no foot rotation in relation to age groups; preschool children displayed a prevalence of no foot rotation 48.95% and the adolescent population 13.55%. In conclusion, FSP in children are influenced by age. It is noteworthy that the RFS prevalence of children is lower in comparison to the adult population. 相似文献
897.
Nikos V. Margaritelis Anastasios A. Theodorou Antonios Kyparos Michalis G. Nikolaidis Vassilis Paschalis 《Journal of sports sciences》2019,37(14):1630-1637
Underfat individuals have been neglected as a malnourished population in terms of redox homeostasis. The aim of the present study was to evaluate the effect of body composition on redox homeostasis at rest and in response to exercise. Underfat, lean and overfat women, classified according to their BMI and body fat percentage, participated in the study and were subjected to an acute session of eccentric exercise. With regard to muscle function and damage, a significant group × time interaction was found for range of motion (P < .01), isometric peak torque at 90° (P < .01), delayed onset muscle soreness (P < .01) and creatine kinase (P < .05), with the lean group generally exhibiting faster recovery compared to the underfat and overfat groups. With regard to redox homeostasis, a significant group × time interaction was found for F2-isoprostanes, protein carbonyls and glutathione (P < .01 for all biomarkers), with the underfat and overfat groups exhibiting increased resting oxidative stress levels and lower exercise-induced reactive species production . In conclusively, our data underline the importance of normal body composition for redox homeostasis, since underfat and overfat women demonstrate a similar pattern of redox disturbances both at rest and in response to exercise. 相似文献
898.
Philip von Rosen Oskar Olofsson Sebastian Väsbom Annette Heijne 《European Journal of Sport Science》2019,19(5):707-716
The primary aim of this cross-sectional study was to compare subjective correlates of health, such as nutrition, self-esteem, sleep and stress, between adolescent elite athletes (n?=?625) and a reference group of adolescents (n?=?391) not involved in elite sports. A secondary aim was to study predictors for self-perceived stress. A questionnaire was e-mailed to all participants containing valid questions about competence-based self-esteem, nutrition, self-perceived stress and sleep. Our results show that adolescent elite athletes reported significantly (p?.001) lower self-perceived stress, competence-based self-esteem, a more varied diet and more time of sleep, compared to adolescents not involved in elite sports (Hedges’g 0.31–0.82). Female adolescent elite athletes and female adolescents, compared to their male peer group, reported poorer values for competence-based self-esteem (elite, Hedges’g 0.29; adolescents, Hedges’g 0.30) and self-perceived stress (elite, Hedges’g 0.63; adolescents, Hedges’g 0.60). The linear mixed effect model revealed several significant (p?.05) predictors (sex, general well-being, competence-based self-esteem, sleep during weekdays, BMI, training volume) associated with self-perceived stress in adolescent elite athletes. In conclusion, differences in correlates of health with a moderate to strong effect sizes were found between the two groups, where elite athletes surprisingly reported less stress, competence-based self-esteem, a more varied diet and more time of sleep. Even if injury risk is high in adolescent elite athletes and pressure from multiple stakeholders is evident, it appears that the athletes still have better conditions for a good subjective health, based on self-reported measures, compared to adolescents not involved in elite sports. 相似文献
899.
900.
Using a mathematical procedure, we determine appropriate sampling rates for logging heart rate, at a variety of exercise intensities. The mathematical procedure involves correlating exercise and heart rate data to determine a dynamical mathematical model, from which the frequency response of the relationship between exercise intensity and heart rate can be determined. The sampling rate is then straightforwardly deduced by making appropriate measurements on the frequency response curve. We show how careful consideration needs to be given to the choice of dynamical model structure and the work regimen, so that consistent and convincing conclusions can be drawn. We demonstrate that the dynamics of the work-rate/heart-rate system are dependent on the nominal work/heart rate, but a 5-s sampling period, as used in many commercial heart rate monitors, appears to be adequate, especially when some averaging is performed before logging. 相似文献