The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol x 1(-1) (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant (P > 0.05). Blood lactate concentration was significantly higher (P < 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm. 相似文献
ABSTRACTThis paper reports findings from a project called “The National Panel of Raters” (NPR) that took place within a writing test programme in Norway (2010–2016). A recent research project found individual differences between the raters in the NPR. This paper reports results from an explorative follow up-study where 63 NPR members were surveyed with 23 items that were dilemma-like in the sense that deviating from the NPR rules would follow another—but socially acceptable—rationale. Four NPR members participated in a follow-up interview in which they motivated why they had agreed or disagreed with certain items. The results indicate two distinctly different stances toward rating work, with one stance threatening the validity of the scoring process. 相似文献
The continuity of behavioral adjustment from preschool through elementary school and junior high school years was examined. 541 children aged 9-15 years from a preschool epidemiological study were relocated and behavior checklist data obtained. Analyses focused on the relationship between internalizing and externalizing behavior dimensions from the preschool to follow-up periods. It was found that preschool externalizing symptoms were positively correlated with later externalizing and internalizing symptoms in the entire sample. Preschool internalizing symptoms, however, were predictive of later internalizing symptoms only for 2-year-old girls and 5- and 6-year-old boys. Similar results were obtained for clinically disturbed preschoolers. Results are consistent with previous findings regarding the longitudinal continuity of externalizing behavior but are at odds with reports of equal or greater stability of internalizing behavior. Given the magnitude of obtained correlations, even when significant, the results support the view that discontinuity rather than continuity in behavioral adjustment from preschool to later ages is the rule. The importance of examining other mediating variables in the prediction of behavioral adjustment and the need for models of development that encompass both stability and change are discussed. 相似文献
To help students acquire mathematics and science knowledge and competencies, educators typically use multiple external representations (MERs). There has been considerable interest in examining ways to present, sequence, and combine MERs. One prominent approach is the concreteness fading sequence, which posits that instruction should start with concrete representations and progress stepwise to representations that are more idealized. Various researchers have suggested that concreteness fading is a broadly applicable instructional approach. In this theoretical paper, we conceptually analyze examples of concreteness fading in the domains of mathematics, physics, chemistry, and biology and discuss its generalizability. We frame the analysis by defining and describing MERs and their use in educational settings. Then, we draw from theories of analogical and relational reasoning to scrutinize the possible cognitive processes related to learning with MERs. Our analysis suggests that concreteness fading may not be as generalizable as has been suggested. Two main reasons for this are discussed: (1) the types of representations and the relations between them differ across different domains, and (2) the instructional goals between domains and subsequent roles of the representations vary.
