Association of daily sitting time and leisure-time physical activity with body fat among U.S. adults

Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.Methods:This was a cross-sectional analysis of U.S.nationally representative data from the National Health and Nutrition Examination Survey2011-2018 among adults aged ...     

Epidemiology of insertional and midportion Achilles tendinopathy in runners:A prospective cohort study

Background:Achilles tendinopathy(AT) is a common problem among runners.There is only limited evidence for risk factors for AT,and most studies have not defined the AT subcategories.No study has compared the incidence and risk factors between insertional AT and midportion AT,though they are considered distinct.This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort.The secondary aim was to explore differences in risk factors between insertional an...     

意义学习分类学

综合十年的研究,作者描述了意义学习的一种分类办法.最有意义的学习结果是解决问题.在这种分类法中,四种不同的问题解决按层次方式排列.解决问题的先决条件是两种基本的推理技能——类比推理和因果推理,这是解决所有问题的基础.这些推理的形式要求运用概念,以及由概念和关系组成的低阶命题和高阶命题.解决问题的教学应该是让学习者解决问...     

商品个性标志的定义及其在美国流行文化中的角色

在过去的一个多世纪,商品的个性标志一直是美国人钟爱的广告工具。各种各样被广告商作为传播体系的＂会说话的动物＂和＂会跳舞的产品＂已悄无声息地蔓延在美国的流行文化中。1982年,有人在做调查后发现,凡是商品特征明显的广告,在改变品牌偏好的能力上要比同行业其他品牌强。这一点表明社会正在接收商品个性标志这样的讯息。然而,尽管商品个性标志的运用在广告商和消费者中大受欢迎,却几乎被完全遗忘在广告和流行文化研究的角落。本文将从相关文学的角度解析什么是商品个性标志,以及其如何运用在现代广告业中,并与消费者进行交流。     

体力活动与癌症生存研究的10大问题

摘要：今天的美国有1 400万的癌症存活者,其中的很多存活者中都接受了多种治疗,包括手术、放疗、化疗、靶向治疗等。这些治疗能够延长生存时间,但同时也会带来很多急慢性的副作用,危害健康,影响生活质量。体力活动（PA）与癌症生存这一领域发展迅速,主要研究PA对癌症患者的影响。基于该领域的研究进展,提出了以下10大研究问题：1）PA能够降低癌症复发风险、和/或提高存活吗？2）PA能够影响癌症治疗决策、完成率、和/或患者对治疗的反应吗？3）癌症存活者的最佳运动处方是什么？4）静坐少动行为对癌症存活者有何影响？5）癌症存活者最有效的体力活动干预方案是什么？6）哪些癌症会影响病人对PA的反应？7）癌症存活者进行体力活动时需要注意的安全问题有哪些？8）哪些具体的癌症症状可以由PA解决？9）对于癌症晚期患者,体力活动还有何作用？10）如何将体力活动研究结果转化到临床和社区肿瘤实践中来？上述问题的回答至关重要,这不仅关系到体力活动和癌症存活这一研究领域的发展,更重要的是,能够为每年数百万新诊断为癌症的病人、正在接受癌症治疗的病人、治疗结束处于恢复中的病人或是那些正在与晚期癌症抗争的病人带来福音。     

Coordination variability and skill development in expert triple jumpers

The aim of this study was to examine the influence of skill of expert triple jumpers on the coordination variability of lower extremity intra-limb couplings. In contrast to the traditional motor learning perspective, we hypothesized that as skill and thus performance increases, movement coordination variability will also increase. Three-dimensional kinematic and ground reaction force data were collected during the hop-step transition phase of the triple jump. Relative motion plots and a modified vector coding technique were used to quantify the coordination variability across the trials. The results were consistent with a U-shaped curve, representing coordination variability, as skill increases. The high coordination variability in less skilled athletes is present while the appropriate characteristics defining the movement coordination patterns are acquired. This coordination variability may not be beneficial to performance. As the refinement of these characteristics is achieved, coordination variability decreases, resulting in a more consistent or regulated performance. In the final stages of developing a skilled performance, a functional variability is accessed that brings flexibility to the system allowing it to cope with perturbations. This study highlights the need to address the learning effect when analysing coordination variability from a dynamical systems perspective.     

迷上练习场

在许多职业赛事上,你不用破费很多就可以大有所获。乔·狄克逊的下巴紧紧贴在球场的钢丝网上,场内的罗杰·费德勒现在离她只有不到5码远。这位她最喜爱的网球选手,在她的注视下练习完上旋发球后,接着开始练习正手抽击。这是一记典型的费德勒式正拍,球"嗖"地飞出,刚刚过网,狠狠地砸在了边线上。狄克逊情不自禁地吹了个口哨,费德勒轻     

巴黎风情画——Blizzard WWI 2008赛场日记

很荣幸参加2008 Blizzard Enter- tainment Worldwide Invitational,作为WE魔兽世界竞技场战队的成员。第一次参加《魔兽世界:燃烧的远征》(World of WarCraft:The Burning Crusade)的竞技场大赛,虽然最后没能取得理想的成绩,但从魔兽世界目前极少的线下赛来看,WWI确实是一次难得的锻炼机会,这次失败也促使我更加努力的练习,对胜利的渴望,遗憾绝对不会留到下次!     

浅谈初级DotA CW阵容与节奏的掌握

DotA游戏基本可以分为以下几个层次：单机AI、路人战、IH、CW比赛。当你厌倦了每天在路人房里孤军备战,而有时队友又让你无奈。或许会找到一个小团体进行IH、内战、开黑,而开黑时往往双方实力悬殊,不能良好地发挥个人实力,基本会养成一些路人战的坏习惯。这时找一个大的平台,进行CW吧!这更正式、更有竞技性,双方都有很强实力的比赛是非常精彩的。其中在IH以后就要考虑阵容问题了,而高等CW还要考虑相互克制关系,团战破解对方优势的打法,这里主要谈一下目前较热的初级CW的一些细节。     

《电子竞技》专访：走近波兰战神NEO

今天《电子竞技》特约记者N.n为大家带来一个neo的独家采访。采访的过程其实是一波三折的,早在一个月前我们打算为这位憨态可掬的战神小朋友（呃,憨态可掬,原谅我用了这个词,暂时没有想到别的形容他可爱的词）做一个特别专访。