Day-level sedentary pattern estimates derived from hip-worn accelerometer cut-points in 8–12-year-olds: Do they reflect postural transitions?

Improving sedentary measurement is critical to understanding sedentary-health associations in youth. This study assessed agreement between the thigh-worn activPAL and commonly used hip-worn ActiGraph accelerometer methods for assessing sedentary patterns in children. Both devices were worn by 8–12-year-olds (N = 195) for 4.6 ± 1.9 days. Two ActiGraph cut-points were applied to two epoch durations: ≤25 counts (c)/15 s, ≤75c/15s, ≤100c/60s, and ≤300c/60s. Bias, mean absolute deviation (MAD), and intraclass correlation coefficients (ICCs) tested agreement between devices for total sedentary time and 11 sedentary pattern variables (usual bout duration, sedentary time accumulated in various bout durations, breaks/day, break rate, and alpha). For most sedentary pattern variables, ActiGraph 25c/15s, 75c/15s, and 100c/60s had poor ICCs, with bias and MAD >20%. ActiGraph 300c/60s had a better agreement than the other cut-points, but all ICCs were <0.587. ActiGraph underestimated sedentary time in longer bouts and usual bout duration, and overestimated sedentary time in shorter bouts, breaks/day, and alpha. For total sedentary time, ActiGraph 25c/15s, 300c/60s, and 75c/15s had good/fair ICCs, with bias and MAD <20%. Sedentary patterns derived from two commonly used ActiGraph cut-points did not appear to reflect postural changes. These differences between measurement devices should be considered when interpreting findings from sedentary pattern studies.     

Learning to Lead: an Approach to Mathematics Teacher Leader Development

This paper describes a partnership between a university and an urban school district, formed with a goal of preparing mathematics teacher leaders to conduct professional development (PD) at their schools. The university and district partners worked together to achieve the district’s mission of providing every student with high-quality instruction and equitable learning opportunities in mathematics by building the district’s capacity to conduct school-based PD for mathematics teachers. Given the power of school-based subject-specific PD for improving instructional quality, we worked with Teacher Leaders from participating schools to prepare and support them to lead PD workshops at their schools. In this paper, we examine how Teacher Leaders learn and adapt key elements of a PD model over three school years through the lenses of Prediger et al.’s Three-Tetrahedron-Model (2019) and the university’s Learning to Lead model. Over 3 years, we see that Teacher Leaders use the key structures of the PD model; make adaptations in response to school goals, interests, and priorities; and gain confidence in their work with colleagues. By viewing the adaptations through the lens of pedagogies of practice as well as the relationships illustrated by the 3-T model, this work offers insights into the complexities of teacher leadership development.

     

架起金桥 话交流

1994年10月,地处“东南阙里”的衢州二中,因为抗战时期的一个美丽故事,奏响了一所学校与多个国家的教育文化交流的序曲。16年来,有100多位教师,带着二中人特有的凤采和儒学校园的滋养,远赴美国、英国、德国、日本、巴西、新加坡等20多个国家和地区任教、访问、交流;16年来,美国、英国、德国、法国等20多个国家的教师也络绎不绝地来到衢州二中交流。文化教育这座“金桥”已构架在不同国度的无数人心中,衢州二中走出了一条富有特色的与世界融合之路。那么,我们就来聆听这所学校的老师、外籍教师以及去国外交流学习的学生在中外文化教育交流中的心声吧!     

Comparison of split double and triple twists in pair figure skating

In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.     

THE IMPACT OF INSTITUTIONAL CHOICE AND ENVIRONMENTS ON AFRICAN-AMERICAN AND WHITE STUDENTS' DEGREE EXPECTATIONS

This study examines the effects of individualcharacteristics, institutional characteristics andexperiences, and financial aid measures onAfrican-American and white college students' degreeaspirations. The main theoretical foundations for this studyare the status attainment models developed in the early1970s and Weidman's (1989) model of undergraduatesocialization. The study used the BeginningPostsecondary Students (BPS:90/92) data set, and the findingsshow that regression models between the two groups havemany similarities: Students' aspirations are mostly theresult of socioeconomic factors, initial degree aspirations, and institutional characteristics.Financial aid measures are not significant predictors ofaspirations for African-American students, although workstudy awards and fewer hours per week spent working significantly affect white students'aspirations. There are quite a few differences betweenthe groups' regression models. For instance,intellectual selfconfidence has opposite effects onaspirations for African-American and white students.African-American enrollment and faculty contactpositively affect AfricanAmerican students' aspirations,while tuition cost and peer contact have positiveeffects on white students' aspirations.     

Adults' prior exposure to print as a predictor of the legibility of text on paper and laptop computer

This study investigated the effects of variations in graphic elements that account for differences in speed and accuracy between reading text aloud from paper versus laptop computer. Variations in accurate reading-aloud performance are attributable to individual differences in the visual accessibility of information due to (1) the experimental manipulations of the independent variables, (2) the subjects' prior exposure to print within the culture, and (3) the educational attainment of the subject. A non-representative sample of 48 female survey interviewers (ages 38–72) were employed in the conduct of this study. Survey interviewers were selected because they gather information using laptop computers; the quality of the survey information collected may be directly associated with the legibility of computerized text on reader performance. Subjects completed a prior exposure to print questionnaire (Stanovich & West 1989) and a demographic data form (IDIQ). Repeated-measures analyses of variance were employed to examine individual differences in the speed and accuracy of reading-aloud performance for twenty-four conditions varying the levels of independent variables including: (1) Font (Times Roman, Helvetica, and Courier), (2) Justification (fully- justified versus left-justified), (3) Leading (single-spaced versus double-spaced), and (4) Mode of Presentation (paper versus laptop computer). Linear regression analyses found subjects' prior exposure to print significantly and positively related to predicting speed and miscue performance. The subjects' educational attainment significantly predicted miscue performance. Subjects' ages were not significantly related to performance. Results of this study inform computer programmers and designers who are responsible for developing standards and guidelines for legible computerized text for the effective access of accurate information.