Muscle force characteristics of male and female collegiate cross-country runners during overground running     

C. Nathan Vannatta  Thomas G. Almonroeder  Thomas W. Kernozek  Stacey Meardon 《Journal of sports sciences》2020,38(5):542-551

ABSTRACT

Males and females demonstrate unique running mechanics that may contribute to sex-related differences in common running related injuries. Understanding differences in muscle forces during running may inform intervention approaches, such as gait retraining addressing muscle force distribution. The purpose of this study was to compare muscle force characteristics and inter-trial variability between males and females during running. Twenty female and 14 male collegiate cross-country runners were examined. Three-dimensional kinetic and kinematic data were collected during overground running and used to estimate muscle forces via musculoskeletal modelling. Principle components analysis was used to capture the primary sources of variance from the muscle force waveforms. The magnitude of the forces for the hamstrings, gastrocnemius, and soleus muscles were higher across the majority of stance in male runners regardless of footstrike pattern. Males also demonstrated greater inter-trial variability in the timing of the peak gluteus maximus force and the magnitude of local peaks in the gastrocnemius force waveform. Male and female collegiate cross-country runners appear to employ unique lower extremity muscle force characteristics during overground running.  相似文献   

用户动机视角下的Altmetrics指标研究     

刘晓娟  王晨琳 《图书情报知识》2020,(3):63-70,96

[目的/意义]从用户动机视角对Altmetrics指标的本质和价值进行分析,使Altmetrics的应用更为科学合理。[研究设计/方法]首先对相关文献中的动机进行组织提炼与规范化表述。在此基础上引入用户行为理论解释和分析用户动机体现的指标价值。再选取Twitter提及量指标,使用内容分析法进行案例研究。[结论/发现]提炼出19种用户动机,其中有6种动机会降低指标应用价值。[创新/价值]探索Altmetrics数据的产生机制,在一定程度上回答了Altmetrics指标可用性问题。  相似文献   

国际科研众筹项目的特征描述、主题分析及属性对比:基于Experiment平台的发现     

刘周颖  赵宇翔  巴志超  吴聪  朱庆华 《图书情报知识》2020,(3):71-82

[目的/意义]为了深入了解科研众筹平台中的项目情况,本文对科研众筹项目的基本特征、研究主题和不同类型科研众筹项目的属性对比进行研究。[研究设计/方法]首先对科研众筹的起源、价值和运作模式进行了梳理;随后爬取了科研众筹平台Experiment的项目信息,并对该平台中科研项目的发起者、背书者、项目记录、所属学科、资助情况等进行特征描述;基于LDA模型对科研众筹项目主题进一步细化,并对不同资金筹集和不同主题分类情况下的科研众筹项目的属性差异进行比较分析。[结论/发现]科研众筹主题主要集中在生物学和生态学两个领域,不同资金筹集达成情况的科研众筹项目在项目背书者数量、信息记录次数和讨论次数上具有显著差异;不同主题的科研众筹项目在其讨论次数上具有显著差异。同时,是否提供视频和是否参与资助挑战在不同资金筹集达成情况和不同主题的科研众筹项目上均具有显著差异。[创新/价值]深入分析了科研众筹平台中项目主题及属性对比情况,对科研众筹平台优化信息审核机制、社交机制和信息展示机制具有一定的参考价值。  相似文献   

Populist linguistic tone in recent U.S. presidential campaign discourse: a DICTION analysis     

Craig O. Stewart 《Communication Research Reports》2020,37(1-2):11-21

ABSTRACT

This study analyzed the tone of public campaign remarks of right- and left-wing populist (Donald Trump and Bernie Sanders, respectively) and right and left-wing non-populist (Mitt Romney and Hillary Clinton, respectively) U.S. presidential candidates using DICTION 7.0. Findings suggest that populists tended to use a linguistic tone that is high in pessimism, group abstractness, and exclusion. Pessimism and group abstractness were positively associated with immigration language in right-wing populist speech. Commonality and “we-ness” were positively associated with populist language in left-wing populist speech.  相似文献   

英国的医学知识服务保障体系     

孙会清  何小凤  刘青松 《图书馆论坛》2020,(6):156-165

在"健康中国"战略下,医学知识服务保障体系对建设国家健康信息化服务体系、提高健康教育服务能力和提高全民健康素养进行支撑。文章从医学知识服务管理机构、医学知识服务支持政策、医学知识服务实施策略、医学知识服务研究和培训、医学知识服务合作和医学知识服务质量评价等方面对英国医学知识服务保障体系现状进行分析,提出我国医学知识服务保障体系建设策略:加强医学知识服务管理机构和政策体系建设,开展医学知识服务项目研究和职业教育培训,重视医学图书馆知识服务合作和评价。  相似文献   

拒绝傲慢与偏见:体育教师受歧视现象、根源及消解     

徐剑  林海峰 《吉林体育学院学报》2020,(1):80-83

运用文献资料法、问卷调查法等研究方法对歧视体育教师的现象进行分析。研究认为:体育教师受歧视现象的持续发生,折射出了学校体育教育的缺失。体育教师受到歧视的根源在于传统文化观念的影响、社会对体育教育的偏见、学校体育政策的偏颇、教师职业认同的迷失、个人行为形象失范等。体育教师受歧视现象的消解路径:提升体育教师社会地位,完善学校体育法律法规,优化大众媒介舆论管理,加强体育教师个人修养等。只有如此,才能从根本上扭转和消除体育教师受歧视现象的再发生。  相似文献   

上海国际航运中心建设支持政策的量化评价     

张婕姝  陈靖瑶 《上海海事大学学报》2020,41(1):116-121

为增强上海国际航运中心建设支持政策的有效性,基于2009—2018年间国家及地方政府层面颁布的19个涉及上海国际航运中心建设的政策文本,应用文本挖掘方式提取评价指标,构建PMC指数模型对政策进行量化评价。分别选取3项针对性政策和3项辅助性政策作为评价对象进行实证分析,结果表明:针对性政策的PMC指数总得分高于辅助性政策的PMC指数总得分,且随着上海国际航运中心建设的不断推进,其引导作用不断加强;辅助性政策虽然只考虑到上海国际航运中心的部分建设需求,但在保障激励等方面给予了高度重视。  相似文献   

集装化危险品物流作业风险因素识别与评价     

何景师  张智勇 《上海海事大学学报》2020,41(4):62-69

为识别与评价集装化危险品物流作业的风险因素，通过鱼骨图分析法构建风险因素评价指标体系。以风险发生的概率和后果为决策变量建立基于熵权 层次分析法（analytic hierarchy process, AHP）约束的数据包络分析(data envelopment analysis, DEA)法的风险评价模型。利用熵权 AHP解决传统DEA法的权重无限性问题，利用DEA法求解风险极大、极小值并对风险因素进行评价与排序。研究发现，人员风险、包装风险达到风险极大值，集装箱风险达到风险极小值。研究得到各风险因素决策单元的风险降低比例，并根据风险因素的特点提出集装化危险品物流作业风险管理的建议。结果表明了该评价模型的适用性和评价方法的科学性。  相似文献   

2001-2017年尼泊尔中部地区滑坡变化及其影响因素     

孙国庆  陈方  于博  王宁 《中国科学院大学学报》2020,37(3):308-316

滑坡是造成尼泊尔巨大经济损失和人员伤亡的主要地质灾害。目前，遥感方法对滑坡信息的识别、提取和监测具有巨大的潜力。基于随机森林模型的平均不纯度减少算法，选用NDBI、MNDWI、NDVI和红波段4个参数对Landsat遥感数据进行滑坡信息的初提取，同时借助目视解译得到滑坡的精提取结果。采用数据格网的方法将研究区划分为0.05°×0.05°的滑坡格网，并在不同土地覆盖类型中，对滑坡与降雨和温度进行偏相关分析。研究表明：1）尼泊尔中部地区的滑坡主要分布在海拔1 000~2 500 m，坡度20°~40°的范围内；2）相比其他土地覆盖类型，林地中滑坡数目与降雨的偏相关系数为0.671 5，而在草地中滑坡数目与温度的偏相关性最强，其偏相关系数为0.436 1；3）研究区片麻岩、页岩分布广泛，加之地震、断裂带、人类活动的影响，破坏边坡的稳定性，极易造成滑坡灾害。  相似文献   

Location extraction from tweets     

Thi Bich Ngoc Hoang  Josiane Mothe 《Information processing & management》2018,54(2):129-144

Five hundred million tweets are posted daily, making Twitter a major social media platform from which topical information on events can be extracted. These events are represented by three main dimensions: time, location and entity-related information. The focus of this paper is location, which is an essential dimension for geo-spatial applications, either when helping rescue operations during a disaster or when used for contextual recommendations. While the first type of application needs high recall, the second is more precision-oriented. This paper studies the recall/precision trade-off, combining different methods to extract locations. In the context of short posts, applying tools that have been developed for natural language is not sufficient given the nature of tweets which are generally too short to be linguistically correct. Also bearing in mind the high number of posts that need to be handled, we hypothesize that predicting whether a post contains a location or not could make the location extractors more focused and thus more effective. We introduce a model to predict whether a tweet contains a location or not and show that location prediction is a useful pre-processing step for location extraction. We define a number of new tweet features and we conduct an intensive evaluation. Our findings are that (1) combining existing location extraction tools is effective for precision-oriented or recall-oriented results, (2) enriching tweet representation is effective for predicting whether a tweet contains a location or not, (3) words appearing in a geography gazetteer and the occurrence of a preposition just before a proper noun are the two most important features for predicting the occurrence of a location in tweets, and (4) the accuracy of location extraction improves when it is possible to predict that there is a location in a tweet.  相似文献