检索结果-南通市图书馆

Physical activity and exercise in children with chronic health conditions

在线全文

学校读者我要写书评

暂无评论

引用

Journal of Sport and Health science 2013年第1期2卷 12-20页

作者： William F. Riner Sarah hunt Sellhorst Health Services University of South Carolina Lancaster Lancaster SC 29720 USA Gregory Health and Wellness Center University of South Carolina Lancaster Lancaster SC 29720 USA

In the last two or three decades,physical activity(PA) has gained increasing recognition as being essential for maintaining good health and improving quality of life for all *** have traditionally been active in both free play and organized ***,there has been a recent decline in the PA levels among children for various *** lifestyle change has resulted in increased obesity accompanied by a rise in diabetes and cardiovascular risk among otherwise healthy *** lifestyle changes have been shown to be even more a problem when the child is already affected by a chronic *** to medical limitations and contraindications,much care must be taken to make certain that these children are involved in the appropriate volume and intensity of *** type of activity must also be given careful consideration to avoid undue risk for the child who may have problems such as poor balance,limited strength,poor vision,or cognitive *** complications are either caused or exacerbated by lack of sufficient *** priority beyond concern for safety should be focused on ensuring the highest quality of life *** purpose of this review is to examine how PA can benefit children with selected chronic health conditions.

关键词： Children Chronic health condition Exercise Physical activity

The potential of a year-round school calendar for maintaining children’s weight status and fitness:Preliminary outcomes from a natural experiment

在线全文

学校读者我要写书评

暂无评论

引用

Journal of Sport and Health science 2020年第1期9卷 18-27,102页

作者： r.glenn weaver ethan hunt aaron rafferty michael w.beets keith brazendale gabrielle tumer-mcgrievy russell r.pate alberto maydeu-olivares brian saelens shawn youngstedt Separtment of exercise science university of south carolinacolumbiasc 29208usa Department of health promotion educationand behavioruniversity of south carolinacolumbiasc 29208usa Department of psychology university of south carolinacolumbiasc 29208usa Center for child health behavior and development seattle children's hospitalseattlewa 98105usa Department of nursing and health innovation arizona state universitytempeaz 85281usa

Purpose: To evaluate the potential of a year-round school calendar (180-day school year distributed across 12 months) as an intervention comparedto a traditional school calendar (180-day school year distributed across 9 months) for mitigating children's weight gain and fitness loss viaa natural ***. Height, weight, and cardiorespiratory fitness (CRF) (i.e., Fitnessgram Progressive Aerobic Cardiovascular Endurance Run) were measured inchildren (5—12 years old) in 3 schools (2 traditional, 1 year-round, n = 990 students, age = 8.6 土 2.4 years, 53.1% male, 68.9% African American) from1 school district. Structure (represented by the presence of a school day) was the independent variable. Changes in body mass index (BMI), age- andsex-specific BMI z-scores (zBMI), BMI percentile, percent of overweight or obese children, and CRF (Progressive Aerobic Cardiovascular EnduranceRun laps completed) were assessed for summer 2017 (May—August 2017), school year 2017/2018 (August 2017—May 2018), and summer 2018(May—August 2018). Primary analyses examined the overall change in weight and CRF from summer 2017 until summer 2018 via multilevel mixedeffects regression, with group (traditional vs. year-round calendar), time, and a group-by-time interaction as the independent variables. Secondaryregression analyses estimated differences in change within and between groups during each time period, ***. Year-round students gained less BMI (difference in A = —0.44, 95% confidence interval (CI): —0.67 to —0.03) and less CRF (differencein △ = — 1.92, 95%CI: —3.56 to —0.28) than students attending a traditional school overall. Compared with traditional students, during both sum・mers, year-round students gained less BMI (summer 2017 difference in A = —0.15, 95%CI: —0.21 to —0.08;summer 2018 difference in△ = —0.16, 95%CI: —0.24 to —0.07) and zBMI (summer 2017 difference in A = —0.032, 95%CI: —0.050 to —0.010;summer 2018 difference in△ = —0.033, 95%CI: —0.056 to —0.009

关键词： Children Intervention Obesity Overweight Policy school calendar

在线全文

学校读者我要写书评

暂无评论

低钙质黑色页岩的物质来源

引用

世界地质 1993年第4期12卷 74-79页

作者： M.S.Quinby-hunt P.Wilde 刘家军

沉积岩中元素的富集取决于每个元素的化学性质。这些元素是风化作用、沉积作用、成岩作用、石化作用和低级变质作用的产物。但是人们认为,不活泼的碎屑物质组分具有初始火成源的特征。这一认识对研究黑色页岩的物质来源有很大帮助。为... 详细信息

沉积岩中元素的富集取决于每个元素的化学性质。这些元素是风化作用、沉积作用、成岩作用、石化作用和低级变质作用的产物。但是人们认为,不活泼的碎屑物质组分具有初始火成源的特征。这一认识对研究黑色页岩的物质来源有很大帮助。为了确定低钙质(CaCO_3sc三角图解能鉴别出微量元素来自上地壳、陆壳,或是洋壳(Taylor和Mclennan,1985)。所有低钙质黑色页岩样品都集中在上地壳的区域内。人们普遍用Th—Hf—Co三角图来鉴别它们是来自上地壳还是整个陆壳,或是洋壳。在黑色页岩形成的环境中,由于Co元素对氧化还原很敏感,故在三角图解中,用一个不活泼的化学元素(如Rb)替代Co是必要的。取代以后,所有黑色页岩样品均集中在上地壳的区域内。为了确定花岗质组分的来源(Pearce等,1984),样品在Ta—Yb图解和Rb—(Yb+Ta)图解上的投点都集中在边缘分离火山弧花岗岩(VAG)、同碰撞花岗岩(Syn—COLG)与板块内花岗岩(WPG)三者的交界处。大部分样品落于火山弧花岗岩域内,无洋脊花岗岩(ORG)出现。Wood等(1979)的Th—Hf/3—Ta三角图解证实了海相黑色页岩中少量的微量元素来自玄武岩。黑色页岩的投影点很集中,且集中在高Th含量区域,但落于各种玄武岩区域之外,说明黑色页岩来自大陆壳。

关键词：低钙质黑色页岩物质来源页岩