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Marc S. Wells 《European Journal of Sport Science》2016,16(8):912-918
It has previously been shown that cyclists are unable to maintain a constant power output during cycle time-trials on hilly courses. The purpose of the present study is therefore to quantify these effects of power variation using a mathematical model of cycling performance. A hypothetical cyclist (body mass: 70?kg, bicycle mass: 10?kg) was studied using a mathematical model of cycling, which included the effects of acceleration. Performance was modelled over three hypothetical 40-km courses, comprising repeated 2.5-km sections of uphill and downhill with gradients of 1%, 3%, and 6%, respectively. Amplitude (5–15%) and distance (0.31–20.00?km) of variation were modelled over a range of mean power outputs (200–600?W) and compared to sustaining a constant power. Power variation was typically detrimental to performance; these effects were augmented as the amplitude of variation and severity of gradient increased. Varying power every 1.25?km was most detrimental to performance; at a mean power of 200?W, performance was impaired by 43.90?s (±15% variation, 6% gradient). However at the steepest gradients, the effect of power variation was relatively independent of the distance of variation. In contrast, varying power in parallel with changes in gradient improved performance by 188.89?s (±15% variation, 6% gradient) at 200?W. The present data demonstrate that during hilly time-trials, power variation that does not occur in parallel with changes in gradient is detrimental to performance, especially at steeper gradients. These adverse effects are substantially larger than those previously observed during flat, windless time-trials. 相似文献
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Turşucu Süleyman Spandaw Jeroen de Vries Marc J. 《Research in Science Education》2020,50(5):2131-2157
Research in Science Education - Students in upper secondary education encounter difficulties in applying mathematics in physics. To improve our understanding of these difficulties, we examined... 相似文献
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Resham S. Dhariwal Marc P.Y. Desmulliez 《European Journal of Engineering Education》2005,30(3):341-352
Whereas research in MicroSystems Technology (MST) has grown rapidly over the last twenty years, the education of engineers at postgraduate level is still in its infancy. The number of dedicated MST research institutions, companies and university laboratories worldwide has grown at a dramatic rate and all require trained individuals who can be immediately operational in the workplace. With the possible exceptions of Germany and Switzerland, the authors of this article believe that the training requirements for such scientists, engineers and technicians have not been satisfactorily addressed as yet. Realising the need for adequate training in MST, the British funding agency for research in science and engineering, the EPSRC (Engineering and Physical Sciences Research Council) awarded a substantial grant to Heriot-Watt University in order to set up a Masters Training Package (MTP). The context of this grant, the syllabus developed for this Master of Science as well as its implementation are presented in this article. Advantages and drawbacks of block-based delivery of the course are presented from a pedagogical point of view for the different categories of students (full-time students, part-time students and company delegates). 相似文献
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Marschark M Sapere P Convertino C Seewagen R 《Journal of deaf studies and deaf education》2005,10(1):38-50
Despite the importance of sign language interpreting for many deaf students, there is surprisingly little research concerning its effectiveness in the classroom. The limited research in this area is reviewed, and a new study is presented that included 23 interpreters, 105 deaf students, and 22 hearing students. Students saw two interpreted university-level lectures, each preceded by a test of prior content knowledge and followed by a post-lecture assessment of learning. A variety of demographic and qualitative data also were collected. Variables of primary interest included the effects of a match or mismatch between student interpreting preferences (interpreting vs. transliteration) and the actual mode of interpreting, student-interpreter familiarity, and interpreter experience. Results clarify previous contradictory findings concerning the importance of student interpreting preferences and extend earlier studies indicating that deaf students acquire less than hearing peers from interpreted college-level lectures. Issues relating to access and success in integrated academic settings are discussed as they relate to relations among student characteristics, interpreter characteristics, and educational settings. 相似文献
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Marschark M 《Journal of deaf studies and deaf education》2007,12(2):125-126
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Stability in cardiac indicators before birth and their utility in predicting variation in postnatal development were examined. Fetal heart rate and variability were measured longitudinally from 20 through 38 weeks gestation (n = 137) and again at age 2 (n = 79). Significant within-individual stability during the prenatal period and into childhood was demonstrated. Fetal heart rate variability at or after 28 weeks gestation and steeper developmental trajectories were significantly associated with mental and psychomotor development at 2 years (n = 82) and language ability at 2.5 years (n = 61). These data suggest that the foundations of individual differences in autonomic control originate during gestation and the developmental momentum of the fetal period continues after birth. 相似文献
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Duggan A Caldera D Rodriguez K Burrell L Rohde C Crowne SS 《Child abuse & neglect》2007,31(8):801-827
OBJECTIVES: To assess the impact of a voluntary, paraprofessional home visiting program in preventing child maltreatment and reducing the multiple, malleable psychosocial risks for maltreatment for which families had been targeted. METHODS: This collaborative, experimental study focused on 6 Healthy Families Alaska (HFAK) programs; 325 families were enrolled in 2000-2001, randomized to intervention and control groups, and interviewed to measure baseline attributes. Follow-up data were collected when children were 2 years old (85% follow-up rate). Outcomes included maltreatment reports, measures of potential maltreatment and parental risks, for example, poor mental health, substance use, and partner violence. HFAK records were reviewed to measure home visiting services. Home visitors were surveyed to measure perceived effectiveness and training adequacy. RESULTS: Parental risks were common at baseline, and one-sixth of families had a substantiated child protective services report in the child's first 2 years of life. There was no overall program effect on maltreatment reports, and most measures of potential maltreatment. Home visited mothers reported using mild forms of physical discipline less often than control mothers. The groups were similar in their use of more severe forms of physical discipline. There was no program impact on parental risks. There was no impact on outcomes for families with a 'high dose' of home visiting. Home visitors often failed to address parental risks and seldom linked families with community resources. Contradictions in the model compromised effectiveness. CONCLUSIONS: The program did not prevent child maltreatment, nor reduce the parental risks that had made families eligible for service. Research is needed to develop and test strategies to improve the effectiveness of home visiting. 相似文献