The effect of two different 18-week walking programmes on aerobic fitness, selected blood lipids and factor XIIa

Forty-nine previously sedentary or low active individuals aged 40-71 years were allocated to three groups. The long walking group participated in an 18-week walking programme which consisted of walks lasting 20-40 min; the repetitive short walking group completed walks of between 10 and 15 min, up to three times a day, with no less than 120 min between each walk; and the control group maintained their low level of activity. Both walking programmes began at a prescribed 60 min x week(-1), which increased steadily up to 200 min x week(-1) by week 12. During the study, the long walking group walked for an estimated 2514 min (139 min x week(-1)), expending an estimated 67.5 MJ (3.72 MJ x week(-1)) at an estimated 73% of their age-predicted maximum heart rate and 68% of their estimated VO2max. The repetitive short walking group walked for an estimated 2476 min (135 min x week(-1)), expending an estimated 58.5 MJ (3.17 MJ x week(-1)) at an estimated 71% of their age-predicted maximum heart rate and 65% of their estimated VO2max. The results showed a statistically significant reduction in heart rate during a standardized step test (pre- vs post-intervention) in both walking groups, indicating an improvement in aerobic fitness, although the control group showed a higher average heart rate during the post-intervention test, indicating reduced fitness. When compared with the male subjects pre-intervention, the females possessed more favourable levels of high-density lipoprotein (HDL) cholesterol (P< 0.001), apolipoprotein (apo) AI (P < 0.001) and ratios of total cholesterol:HDL cholesterol (P< 0.02) and low-density lipoprotein (LDL) cholesterol: HDL cholesterol (P< 0.02). Compared with the controls post-intervention, the walking groups showed no statistically significant changes in total cholesterol, LDL cholesterol, HDL cholesterol, apo AI, apo AII, apo B, or the ratios of total cholesterol: HDL cholesterol, LDL cholesterol: HDL cholesterol, apo AI: apo B or apo AI: apo AII (P > 0.05). Relative to the walking groups, factor XIIa increased in the control group (P < 0.05). We conclude that, although both walking programmes appeared to improve aerobic fitness, there was no evidence of improvements in the blood lipids or associated apolipoproteins of the walking groups. Further analysis indicated that this apparent lack of change may have been related to the subjects' relatively good pre-intervention blood lipid profiles, which restricted the potential for change. The implications of the observed changes in the coagulation/fibrinolytic factors remain unclear.     

Science in Action: How Middle School Students Are Changing Their World Through STEM Service-Learning Projects

The purpose of Science in Action (SIA) was to examine the relationship between implementing quality science, technology, engineering, and math (STEM) service-learning (SL) projects and the effect on students' academic engagement in middle school science, civic responsibility, and resilience to at-risk behaviors. The innovative project funded by the Corporation for National and Community Service (CNCS) included 6,000+ middle school at-risk students (eligible for at least 50% free or reduced-cost lunch), 126 science teachers who integrated STEM problem-based SL pedagogy into science instruction to teach students to solve real problems in schools and communities. The project involved 20 schools and communities with assistance from 120 community partners. Participants completed pre- and post-SL surveys on academic engagement, civic responsibility, and resilience; qualitative data were collected from journals, interviews, focus groups, observations, and field notes. Results highlight exemplary SL projects that demonstrated increased student academic engagement and achievement for students living in high poverty areas with potential at-risk behavior. Implications for future research and educational practices are discussed.     

When ethnic minority students are judged as more suitable for the highest school track: a shifting standards experiment

When students are grouped into school tracks, this has lasting consequences for their learning and later careers. In Germany to date, some groups of students (boys, ethnic minority students) are underrepresented in the highest track. Stereotypes about these groups exist that entail negative expectations about their suitability for the highest track. Based on the shifting standards model, the present research examines if and how stereotypes influence tracking recommendations. According to this theory, members of negatively stereotyped groups will be judged more leniently or more strictly depending on the framing of the judgment situation (by inducing minimum or confirmatory standards). N = 280 teacher students participated in a vignette study in which they had to choose the amount of positive evidence for suitability they wanted to see before deciding to recommend a fictitious student to the highest track. A 2 (judgment standard: minimum vs. confirmatory) × 2 (target student’s gender: male vs. female) × 2 (target student’s ethnicity: no migration background vs. Turkish migration background) between-subjects design was used. No effects of target gender occurred, but the expected interaction of target’s ethnicity and judgment standard emerged. In the minimum standard condition, less evidence was required for the ethnic minority student to be recommended for the highest track compared to the majority student. In the confirmatory standards condition, however, participants tended to require less evidence for the ethnic majority student. Our experiment underlines the importance of the framing of the recommendation situation, resulting in a more lenient or stricter assessment of negatively stereotyped groups.

     

德国电子书与电子书阅读器的现状及未来发展

概述德国电子图书市场的现状,重点论述德国电子阅读设备的传播和电子图书的市场容量。指出电子图书和电子阅读器市场的最重要驱动力和市场壁垒,并对2015年的电子图书和阅读器市场状况进行预测。     

Mathe mit der Matte – Verkörperlichtes Training basisnumerischer Kompetenzen

Basic numerical representations are seen as the building block for the successful development of more complex numerical and arithmetic competencies. Extending previous studies focusing on improving basic numerical representations by means of embodied training schemes, the current study focused on an embodied training of children’s place-value understanding. In this vein, 49 secondgraders were trained on solving a number line estimation task by stepping on different fields of a dance mat allowing for separate estimations of tens and units with more effort needed to step on the tens. In a partially randomized cross-over design, two control conditions were used to controll for training effects caused exclusively by the numerical content trained or the use of the dance mat. Interestingly, results revealed specific training effects after both the embodied and the control conditions. However, training effects were significantly more pronounced after the embodied training, thereby providing further evidence for the benefit of an embodied training of the place-value structure of the Arabic number system.     

Effects of Headings on Text Summarization

A summarization task was used to study whether headings influence readers' representations of the topic structure of a text. College students (Experiments 1-3) and sixth- and eighth-graders (Experiment 3) summarized a multiple topic text that (a) included headings introducing every new subtopic, (b) included headings introducing half of the new subtopics, or (c) included no headings. In all experiments, topics were more likely to be included in a summary if they were signaled than if they were not signaled. This effect was magnified when the text was only half signaled: Signaled topics were more likely to appear in a summary if only half the text topics were signaled than if all of the topics were signaled; however, unsignaled topics were less likely to appear in a summary if half of the text topics were signaled than if none of the text topics were signaled. The findings demonstrate that readers rely heavily on headings in a task that emphasizes attention to a text's topic structure. It is suggested that previously observed signaling effects on text recall are mediated by effects on how readers represent a text's topic structure. Copyright 2001 Academic Press.