Effects of an 8-weeks erythropoietin treatment on mitochondrial and whole body fat oxidation capacity during exercise in healthy males     

Amelia Guadalupe-Grau  Ulla Plenge  Signe Helbo  Marianne Kristensen  Peter Riis Andersen  Angela Fago 《Journal of sports sciences》2015,33(6):570-578

The present investigation was performed to elucidate if the non-erythropoietic ergogenic effect of a recombinant erythropoietin treatment results in an impact on skeletal muscle mitochondrial and whole body fatty acid oxidation capacity during exercise, myoglobin concentration and angiogenesis. Recombinant erythropoietin was administered by subcutaneous injections (5000 IU) in six healthy male volunteers (aged 21 ± 2 years; fat mass 18.5 ± 2.3%) over 8 weeks. The participants performed two graded cycle ergometer exercise tests before and after the intervention where VO_2max and maximal fat oxidation were measured. Biopsies of the vastus lateralis muscle were obtained before and after the intervention. Recombinant erythropoietin treatment increased mitochondrial O₂ flux during ADP stimulated state 3 respiration in the presence of complex I and II substrates (malate, glutamate, pyruvate, succinate) with additional electron input from β-oxidation (octanoylcarnitine) (from 60 ± 13 to 87 ± 24 pmol · s^?1 · mg^?1 P < 0.01). β-hydroxy-acyl-CoA-dehydrogenase activity was higher after treatment (P < 0.05), whereas citrate synthase activity also tended to increase (P = 0.06). Total myoglobin increased by 16.5% (P < 0.05). Capillaries per muscle area tended to increase (P = 0.07), whereas capillaries per fibre as well as the total expression of vascular endothelial growth factor remained unchanged. Whole body maximal fat oxidation was not increased after treatment. Eight weeks of recombinant erythropoietin treatment increases mitochondrial fatty acid oxidation capacity and myoglobin concentration without any effect on whole body maximal fat oxidation.  相似文献   

Identity Matching to Scientists: Differences that Make a Difference?     

Hanne Moeller Andersen  Lars Brian Krogh  Eva Lykkegaard 《Research in Science Education》2014,44(3):439-460

Students' images of science and scientists are generally assumed to influence their related subject choices and aspirations for tertiary education within science and technology. Several research studies have shown that many young people hold rather stereotypical images of scientists, making it hard for them to see themselves as future scientists. Adolescents' educational choices are important aspects of their identity work, and recent theories link individual choice to the perceived match between self and prototypical persons associated with that choice. In the present study, we have investigated images of scientists among the segment of the upper secondary school students (20 % of the cohort) from which future Danish scientists are recruited. Their images were rather realistic, only including vague and predominantly positive stereotypical ideas. With a particular Science-and-Me (SAM) interview methodology, we inquired into the match between self- and prototypical-scientists (N?=?30). We found high perceived similarity within a core of epistemological characteristics, while dissimilarities typically related to a social domain. However, combining interview data with survey data, we found no significant statistical relation between prototype match and aspirations for tertiary education within science and technology. Importantly, the SAM dialogue revealed how students negotiate perceived differences, and we identified four negotiation patterns that all tend to reduce the impact of mismatches on educational aspirations. Our study raises questions about methodological issues concerning the traditional use of self-to-prototype matching as an explanatory model of educational choice.  相似文献   

Participatory pedagogy in an open educational course: challenges and opportunities     

Renate Andersen  Marisa Ponti 《Distance Education》2014,35(2):234-249

This article presents an empirical study of an open educational course in an online peer-to-peer university (P2PU). P2PU is a nonprofit organization offering free educational opportunities. Focus is on how peers are part of creating course content in a Web 2.0 environment. Massive open online courses (MOOCs) have evolved into two different pedagogical directions: content-based xMOOCs and connectivist cMOOCs. cMOOCs emphasizing learning in networks developed informally, where learners are part of creating course content, resemble P2PU`s vision. We investigated processes of interaction in co-creation of tasks in an open educational course and what opportunities and challenges emerge. We employed template analysis for coding data. We report two different processes of interaction between users and organizers: problem identification and co-creation of tasks. This study contributes to understanding a new model of teaching and learning through scrutinizing participation in an open educational course and explores implications for the learning experience.  相似文献   

Students teach sex education: introducing alternative conceptions of sexuality     

Alison Buck  Kylie Parrotta 《Sex education》2014,14(1):67-80

In this paper, we describe an exercise that challenges hetero-normative and sexist notions of sexuality, allowing students to envision alternative models. Research shows how active learning eases student anxiety over challenging or threatening material. After reading Jessica Fields' Risky Lessons and Waskul, Vannini, and Weisen's article entitled ‘Women and Their Clitoris’, students designed a sex education curriculum that challenges conventional methods. Beyond critiquing existing sex education models, this exercise provides a space for students to reflect on their own sex education experiences, develop their own ideas for teaching about sex and become comfortable discussing sex and sexuality with their peers. All but one of the students reported finding the activity enjoyable or interesting. More than half of students reported change in their views about sex and sex education as a result of the activity.  相似文献   

Listening for Creative Voices amid the Cacophony of Fiscal Complaint about Art and Design Education     

Angela Clarke  Kylie Budge 《The International Journal of Art & Design Education》2010,29(2):153-162

The current tertiary education climate in Australia and other Organisation for Economic Co‐operation and Development (OECD) countries is one where class numbers are increasing and contact hours between students and teachers are reducing to keep them financially viable. In this context increasing pressure is being placed on teachers to essentially ‘do more with less’ and to perform well, despite the changing conditions. Students, too, are challenged to learn in an environment where they have less time with their teachers. What seems surprising is that all of this is occurring whilst the rhetoric of tertiary institutions is being more closely aligned with contemporary constructivist theories of learning with a focus on producing creative graduates. This pressure is now being keenly felt in creative disciplines where studio models of teaching, which require small classes and substantial contact hours, are seriously under threat. If tertiary institutions genuinely want to produce creative graduates there needs to be more widespread understanding of how creative processes are nurtured and creative minds are fostered. Many experienced teachers in creative disciplines have developed such understanding. Their voices need to be encouraged and supported so that the artistry of their creative pedagogies may be articulated and heard above the cacophony of fiscal complaint. We do not naively suggest that financial issues should be disregarded. We do, however, call for a middle way where sophisticated conversations, about both the quality and viability of creative educational practice, amongst all stakeholders can allow for an authentically creative future to emerge.  相似文献   

Athletic injury, psychosocial factors and perceptual changes during stress.   总被引：1，自引：1，他引：0  

M B Andersen  J M Williams 《Journal of sports sciences》1999,17(9):735-741

In this study, we measured changes in state anxiety, visual perception and reaction time during stress among 196 collegiate athletes participating in 10 sports. The athletes also completed measures of life events and social support at the beginning of their seasons. Measures of life events stress, social support, perceptual changes and changes in reaction time during stress were used as predictors of the number of injuries. For the entire sample, the only significant predictor of injury was negative life events stress (R = 0.45, P < 0.001). Following the suggestions of Smith et al., simple correlations were performed for those with least social support (bottom 33%, n = 65). Among this group, those individuals with more negative life events and greater peripheral narrowing during stress incurred more injuries than those with the opposite profile. Our findings are in line with the model of Andersen and Williams, in that those individuals who were low in a variable that buffers stress responsivity (i.e. social support), their negative life events and peripheral narrowing under stress (large and medium effect sizes, respectively) were substantially related to their number of injuries.  相似文献   

Tracking of Gross Motor Coordination From Childhood Into Adolescence     

Rodrigo Antunes Lima  Anna Bugge  Karin Allor Pfeiffer  Lars Bo Andersen 《Research quarterly for exercise and sport》2017,88(1):52-59

Purpose: The purpose of this study was to analyze tracking and stability of motor coordination in children from age 6 years to ages 9 and 13 years. Method: Data were from the Copenhagen School Child Intervention Study. Motor coordination (MC) was measured using the körperkoordinationstest für Kinder (KTK) test. The crude performance score on every item was converted into a standardized “score” based on the original German reference study, which was used to generate a total standardized motor coordination (MQ) score. The MQ scores, which represented children's level of gross MC, were classified as low (MQ score < 85), normal (MQ score = 85–115), or high (MQ score>115). Pearson correlation was used to calculate the tracking coefficients of each KTK element and MQ score, and weighted kappa was used to analyze maintenance in MC classification groups. Mixed-effects logistic regression analyses were performed to examine the odds of remaining in the low MC group over time based on body mass index (BMI), weight, and height tertiles. Results: Tracking coefficients among the MQ score and each KTK element at different ages were moderate (r>.35). Children in the highest BMI and weight tertiles had a 5.44 and 5.15 times greater chance to be in the lower MC classification group during the 7-year follow-up, respectively, in comparison with children in their lowest tertiles. Conclusion: MC tracked moderately through childhood to early adolescence. Because heavier children had a greater chance to be in the lower MC group at older ages, intervention may be useful at earlier ages for those with lower MC and disadvantageous weight status.  相似文献   

Identifying swimmers as water-polo or swim team-mates from visual displays of less than one second     

Steel KA  Adams RD  Canning CG 《Journal of sports sciences》2007,25(11):1251-1258

Opportunities for ball passing in water-polo may be brief and the decision to pass only informed by minimal visual input. Since researchers using point light displays have shown that the walking or running gait of familiars can be identified, water-polo players may have the ability to recognize team-mates from their swimming gait. To test this hypothesis, members of a water-polo team and a competition swim team viewed two randomized sets of video clips, each less than one second long, of swimmers from both teams sprinting freestyle past a fixed camera. The arm stroke clip sequence showed only the upper body, and the kick sequence showed only the lower body. After viewing each video clip, observers rated their level of certainty as to whether the swimmer presented was a team-mate or not. Discrimination was significantly above chance in both groups. Water-polo players were better able to identify team-mates from their kick, whereas swimmers were better able to do so by viewing arm stroke. Our results suggest that, as with walking and running gait, small amounts of visual information about swimmers can be used for recognition, and so raise the possibility that specific training may be able to improve team-mate classification in water-polo, particularly in newly formed teams.  相似文献   

Using Item Scores and Distractors in Person-Fit Assessment     

Kylie Gorney  James A. Wollack 《Journal of Educational Measurement》2023,60(1):3-27

  相似文献