Mechanical behaviour of cross-country ski racing poles during double poling     

Thomas Stöggl  Lars Karlöf 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):365-380

The purpose of this study was to evaluate the behaviour of cross-country ski poles during double poling on a treadmill using three-dimensional kinematics. The results were compared with standard laboratory tests of the pole manufacturers. A total of 18 skiers were analysed at two speeds (85% and 95% of the maximal speed) at grades of 1.5% and 7%. Variables describing cycle characteristics, bending stiffness, bending behaviour, and trajectories of the pole markers were analysed. Triangular-shaped poles demonstrated the greatest stiffness and lowest variability in maximal bending. Softer poles demonstrated greater variability in bending behaviour and lost ground contact at high skiing speeds, which for some skiers resulted in failure to complete high-speed tests. Considerable variations in pole behaviour for similar poles between skiers were observed, which might be attributed to differences in technique, indicating that mechanical properties of the poles did not exclusively determine pole behaviour in the dynamic situation. The greatest magnitude of pole bending was in the middle part of the pole, which differed from the standard static pole analysis of the manufacturer. Increases in grade demonstrated the greatest effect on pole bending. Distinct differences from the pole manufacturers' laboratory measures were apparent, suggesting that basic pole testing might be adapted.  相似文献   

How does attention relate to the ability-specific and position-specific components of reasoning measured by APM?     

Xuezhu Ren  Frank Goldhammer  Helfried Moosbrugger  Karl Schweizer 《Learning and individual differences》2012,22(1):1-7

The aim of the present study was to clarify the nature of the ability-specific and position-specific components of Raven's Advanced Progressive Matrices (APM) by relating them to a number of types of attention. The ability-specific component represents the constant part of cognitive performance whereas the position-specific component reflects the changes in processing of reasoning items as a result of the changing item position. A special model denoted fixed-links model was used to decompose the data of APM into independent components. Both components were related to two higher-order units of attention, perceptual attention and executive attention, which were derived from the various types of attention. In a sample of 226 participants the position-specific component of APM showed a substantially higher link with executive attention than with perceptual attention whereas the ability-specific component only showed a moderate link with perceptual attention.  相似文献   

Dyslexia heterogeneity: cognitive profiling of Portuguese children with dyslexia     

Andreia Pacheco  Alexandra Reis  Susana Araújo  Filomena Inácio  Karl Magnus Petersson  Luís Faísca 《Reading and writing》2014,27(9):1529-1545

Recent studies have emphasized that developmental dyslexia is a multiple-deficit disorder, in contrast to the traditional single-deficit view. In this context, cognitive profiling of children with dyslexia may be a relevant contribution to this unresolved discussion. The aim of this study was to profile 36 Portuguese children with dyslexia from the 2nd to 5th grade. Hierarchical cluster analysis was used to group participants according to their phonological awareness, rapid automatized naming, verbal short-term memory, vocabulary, and nonverbal intelligence abilities. The results suggested a two-cluster solution: a group with poorer performance on phoneme deletion and rapid automatized naming compared with the remaining variables (Cluster 1) and a group characterized by underperforming on the variables most related to phonological processing (phoneme deletion and digit span), but not on rapid automatized naming (Cluster 2). Overall, the results seem more consistent with a hybrid perspective, such as that proposed by Pennington and colleagues (2012), for understanding the heterogeneity of dyslexia. The importance of characterizing the profiles of individuals with dyslexia becomes clear within the context of constructing remediation programs that are specifically targeted and are more effective in terms of intervention outcome.  相似文献   

Comparative Evaluations of Early Intervention Alternatives: A Response to Commentaries by Guralnick and Telzrow     

Karl R. White  Glenna C. Boyce  Glendon Casto  Mark S. Innocenti  Matthew J. Taylor  Linda Goetze  Diane Behl 《Early education and development》1994,5(1):56-68

This article responds to two commentaries by Guralnick (1993) and Telzrow (1993) published in the October 1993 issue of Early Education and Development. The commentaries addressed the six longitudinal, comparative studies from the Early Intervention Research Institute's (EIRI's) investigations of the effects and costs of early intervention for children with disabilities. In this response to their thoughtful critique, we clarify details of our research design and procedures that may have been unclear. We also discuss the specificity and consistency with contemporary developmental/ecological issues raised by Guralnick We contend that the interventions investigated address important questions about age at start, intensity, and parent involvement with which today's service providers contend. We give our opinion on how the results of these studies should be interpreted, and emphasize their implications for other second-generation early intervention research.  相似文献   

Covariation in conditioned response strength between stimuli trained in compound     

Louis D. Matzel  Karl Shuster  Ralph R. Miller 《Learning & behavior》1987,15(4):439-447

Conditioned lick suppression by water-deprived rats was used to elaborate on recent evidence that the attenuated conditioned response elicited by an overshadowed stimulus may be enhanced by extinction of the overshadowing stimulus with which it had been trained in simultaneous compound. Using a modified serial stimulus arrangement in which a light coexisted with the last half of a tone that terminated with footshock, it was found in Experiment 1 that the tone overshadowed the light. Extinction of the tone-shock association resulted in a virtually complete recovery of the response to the overshadowed light. Using this serial overshadowing procedure, the possibility that the strength of a conditioned response to an element trained in compound covaries as a function of the strength of the response to the other element was tested in Experiment 2. Following overshadowing training similar to that of Experiment 1, independent reinforcement of the overshadowed light, that is, associative inflation, was found to have no deleterious effect on the response to the overshadowing tone. This suggests that the effects of postconditioning extinction and inflation of one element do not have symmetrical effects upon responding to the other element. The results of Experiment 2 were replicated in Experiment 3 using a simultaneous compound stimulus as opposed to the serial compound of the previous studies. These results are discussed in terms of various associative and cognitive models of learning and performance.  相似文献   

Serving two masters: how vocational educators experience marketisation reforms     

Patrick Locke  Karl Maton 《Journal of Vocational Education & Training》2019,71(1):1-20

Contemporary education reforms that draw ideas from the political and economic fields are said to be altering the nature of vocational education. While there are substantial policy studies on the effects of marketisation reforms, fewer analyse the perspectives of vocational educators on such reforms. How vocational educators negotiate the potential clash of values when marketisation reforms are enacted within the sector remains relatively unexplored. This paper aims to incorporate these perspectives in order to explore and help explain the responses of vocational educators to such changes. To do so the paper draws on concepts from Legitimation Code Theory, a sociological framework for analysing practices and beliefs. Specifically, it enacts ‘autonomy codes’, which reveal how external forces impact upon the internal practices of a social field. These concepts are used to analyse the beliefs and perceptions of a group of vocational educators in Australia who are undergoing marketisation reforms. The analysis suggests that many educators are experiencing a growing ‘code clash’ between the goals they attribute to reforms and their own beliefs about public education and the expectations of their students, one which problematises their capacity to reconcile these sets of values and colours their views of changes in the sector.  相似文献   

On the effects of training inductive reasoning: How far does it transfer and how long do the effects persist?     

Welko Tomic  Karl Josef Klauer 《European Journal of Psychology of Education - EJPE》1996,11(3):283-299

Using the same program, two training experiments have been conducted in a Dutch and in a German elementary school. The common expectation was that training in inductive reasoning would transfer both on intelligence tests measuring inductive reasoning and on math performance. Furthermore, it was expected that the training effects would persist for at least some months after training had ended. In experiment 1 (N=34), a rather short training period turned out to be effective with respect to the intelligence test performance but not with respect to math performance. In experiment 2 (N=23), the amount of training in inductive reasoning was systematically varied. It could be shown that transfer on intelligence test as well as on math performance was linearly dependent on the amount of prior training. The training effects were found to persist between four and nine months after training.  相似文献   

Do grades in higher education matter for labour market rewards? A multilevel analysis of all Norwegian graduates in the period 1990–2006     

Karl Ingar Kittelsen Røberg  Håvard Helland 《Journal of Education & Work》2017,30(4):383-402

This paper examines the effects of grades from higher education on labour market outcomes. Economic theory predicts that grades are rewarded in the labour market because employers regard them as an expression of valuable skills or a signal of other sought after attributes. Social closure, however, may give reason to expect no effects. Whether good grades are rewarded in the labour market is thus uncertain. This paper addresses this question by examining whether employers tend to reward good grades in the form of employment and higher income. Previous research has demonstrated that the returns to education vary according to structural–institutional labour market settings. We examined the interaction effects between grades and field-specific characteristics and between grades and sector by analysing data on all graduates in these educational programmes at Norwegian universities and university colleges from 1990 through 2006. The education data are linked with multiple other data sources such as the national tax register and the national employment register. We find that good grades have positive effects on both income and employment and that these effects are influenced by both the type of education and sector.  相似文献   

The Cost-Effectiveness of Increasing Hours Per Week of Early Intervention Services for Young Children with Disabilities     

Matthew J. Taylor  Karl R. White  Alice Kusmierek 《Early education and development》1993,4(4):238-255

Although there is a widespread belief that increasing the hours of early intervention services for children with disabilities will result in increased benefits for the participating children and their families, there is little research evidence to support this point of view. In this study, young children with disabilities were randomly assigned to receive either one hour per week of early intervention services, or three hours per week. Measures of child and family outcomes over the subsequent five-year period demonstrated no consistent benefits associated with increasing the hours of intervention. Possible reasons for the lack of benefits are discussed in the context of previous research.  相似文献   

Lehrplananalyse Als Teil der Curriculumforschung     

Karl Frey 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1969,15(1):4-26

Ohne Zusammenfassung

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Analysis of curricula as a phase in curriculum research

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L'analyse des programmes scolaires comme phase de la recherche sur le Curriculum

  相似文献