Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points     

Kelsey H.Collins  Graham Z.MacDonald  David A.Hart  Ruth A.Seerattan  Jaqueline L.Rios  Raylene A.Reimer  Walter Herzog 《运动与健康科学(英文)》2020,9(2):132-139,197

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.  相似文献   

新疆生产建设兵团普通高校校园足球推广与发展经验探讨     

连殿冬 《当代体育科技》2020,(12):108-108,110

校园足球运动是夯实足球人才的根基,对学生智力发展及身体健康水平的改善与提升具有重要作用。本文以新疆生产建设兵团所属的塔里木大学为具体研究对象,梳理了塔里木大学校园足球运动的发展模式,并在此基础上分析、探讨了塔里木大学校园足球运动推广、管理与发展的成功经验与模式,以及制约塔里木大学校园足球进一步发展的瓶颈。  相似文献   

Teaching skills of student teachers: Calibration of an evaluation instrument and its value in predicting student academic engagement     

《Studies in Educational Evaluation》2014

Student teachers are expected to develop their teaching skills sooner and more rapidly. However, a sound evaluation instrument that can be used to diagnose and monitor the skilfulness level to aid formative assessment of student teachers is still limited. This article is aimed to calibrate and validate a teaching skill evaluation instrument for use in secondary education. A total of 264 student teachers in the Netherlands participated in the study. Rasch and multilevel analyses were used. Results suggest that the evaluation instrument meets the restrictive assumptions of the Rasch model and has predictive value for academic engagement. This adds validation evidence and justifies the calibration of the evaluation instrument to be used for monitoring the development of teacher's teaching skills.  相似文献   

网球精英运动员赛间训练调控影响因素SEM分析     

汤国进  邹克宁 《武汉体育学院学报》2020,54(9):86-94

为定量解释精英运动员重大比赛期间竞技状态显性和隐性影响因素间相互关系，运用文献资料、层次分析、模糊评价、数理统计等研究方法，基于国家队、省市运动队295名网球教练员、运动员调研数据，提出精英网球运动员重大比赛期间竞技状态影响因素假设命题，再引入SEM概念模型，对假设命题进行验证。结果表明：（1）竞技状态SEM概念模型中，体能训练整合度、技能训练整合度、心智训练整合度、适应度与保障度可作为隐性自变量，且均对竞技状态因变量有正向影响作用，H₁、H₂、H₃、H₄假设命题得到验证；（2）经SEM检验，依影响因素权重，精英网球运动员赛间竞技状态调控依次表现为技能训练整合度、心智训练整合度、体能训练整合度、适应度与保障度；（3）精英网球运动员的参赛表现，虽主要取决于竞技训练因子，但对于适应度与保障度中自然环境、社会环境和规程规则等非训练因子，同样不容忽视。  相似文献   

人类发展指数水平与足球运动发展的或然关系——基于面板数据的实证研究     

傅鸿浩  刘波  张廷安  龚波  郭振  肖辉 《武汉体育学院学报》2020,54(11):20-26

足球运动在世界范围内的普及化与社会化程度日益增强，各国（地区）若要获得全球化竞争中的优势，应注重探讨社会与足球运动发展的关系。通过对1993-2017年131个国家（地区）的人类发展指数与足球排名积分的面板数据建模，以揭示两者之间的关系。研究结果表明，不同国家（地区）的人类发展指数对足球运动发展的影响应建立个体和时点双固定效应模型，模型最高的R²为0.871 32，F检验值为71.014 65，P<0.001，该模型具备较高的解释能力。结论：固定效应模型在考虑历时性因素与不宜观测因素后，在1993-2017年阶段，人类发展指数对于足球运动的发展作用存在分化现象，尤其对亚洲与人口大国的足球运动发展存在制约作用，对南美洲与中等人口国家存在促进作用，人类发展指数与足球运动发展存在一定的或然关系。人类发展指数反映了社会发展的综合水平，对于存在制约效应的国家而言，应当着重考虑社会其它领域（经济、教育、医疗卫生等）与足球运动的互动、协同与融合发展。  相似文献   

地方足球协会软法治理模式、困境与对策研究——基于苏、浙、沪三省市调查的实证分析     

白杨  王家宏 《武汉体育学院学报》2020,54(11):41-48

运用文献研究法、饱和经验法、典型案例分析法对苏、浙、沪三省市地方足球协会进行实证研究，依据软法制定主体和实施主体的不同，提炼概括了当前地方足球协会的两种软法治理模式，即省级层面地方足球协会"政府主导型"软法治理模式和市级层面地方足球协会"多维互动型"软法治理模式，并对这两种模式的特征进行比较分析。继而归纳了当前地方足球协会软法治理"程序缺失、责任制度不规范、承诺滞后和权利救济缺失"的四个困境，从"内部法人治理结构、相关主体法治观念、软法的程序、监督问责机制"四个方面阐释了产生软法治理困境的原因，最后提出四项地方足协软法治理的对策建议。  相似文献   

Business Intelligence Capabilities and Firm Performance: A Study in China     

《International Journal of Information Management》2021

The development of artificial intelligence (AI) technology expands the boundary of business practice, inducing the emergence and application of business intelligence (BI) that has promoted the transformation of information techniques to optimize business decision and operation. However, there is a lack of theoretical consensus and measurement of the technology embedded in BI at present. This study exploratively develops the Sense-Transform-Drive (STD) conceptual model of BI based on dynamic capabilities theory and organizational evolutionary theory to explain the core BI capabilities. By using factoring analysis and structural equation modeling analysis, we extract the latent constructs and empirically verify the validity of the STD model and further examine the correlation and mode of interaction of the three core BI capabilities and the impact of BI application on firm performance in the real economy with a sample contextual to Chinese business practices. The study results show that there are direct and high-intensity cumulative positive effects among the structural components of the STD conceptual model and BI-related dynamic capabilities can enhance operating efficiency and firm performance.  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   

Ancient Mural Classification Method Based on Improved AlexNet Network     

Jianfang Cao  Hongyan Cui  Qi Zhang  Zibang Zhang 《文物保护研究》2020,65(7):411-423

ABSTRACT

As an important part of art and culture, ancient murals depict a variety of different artistic images, and these individual images have important research value. For research purposes, it is often important to first determine the type of objects represented in a painting. However, the mural painting environment makes datasets difficult to collect, and long-term exposure leads to underlying features that are not distinct, which makes this task challenging. This study proposes a convolutional neural network model based on the classic AlexNet network model and combines it with feature fusion to automatically classify ancient mural images. Due to the lack of large-scale mural datasets, the model first expands the dataset by applying image enhancement algorithms such as scaling, brightness conversion, noise addition, and flipping; then, it extracts the underlying features (such as fresco edges) shared by the first stage of a dual channel structure. Subsequently, a second-stage deep abstraction is conducted on the features extracted by the first stage using a two-channel network, each of which has a different structure. The obtained characteristics from both channels are merged, and a loss function is constructed to obtain the classification result. This approach improves the model's robustness and feature expression ability. The model achieves an accuracy of 84.24%, a recall rate of 84.15%, and an F1-measure of 84.13% when applied to a constructed mural image dataset. Compared with the AlexNet model and other improved convolutional neural network models, the proposed model improves each evaluation index by approximately 5%, verifying the rationality and effectiveness of the model for automatic mural image classification. The mural classification model proposed in this paper comprehensively considers the influences of network width and depth and can extract rich details from mural images from multiple local channels. An effective classification method could help researchers manage and protect mural images in an orderly fashion and quickly and effectively search for target images in a digital mural library based on a specified image category, aiding mural condition monitoring and restoration efforts as well as archaeological and art historical research.  相似文献   

学习团队协作信息搜索的共享心智模型研究   总被引：1，自引：0，他引：1  

颜端武  张馨月  汤佳丽  苏琼 《图书情报工作》2020,64(8):3-12

[目的/意义] 对协作信息搜索进行深入研究，为专业化协作信息搜索系统平台建设优化等提供启发和借鉴。[方法/过程] 聚焦于学习团队的信息搜索行为，以高校学生为研究样本，以共享心智模型为切入点，采用扎根理论研究方法，探讨协作信息搜索中团队共享心智模型建构过程。[结果/结论] 识别出四大核心环节——个体感知与探索、团队任务解析、团队信息收集和团队信息整合，并理清各环节的认知活动与共享心智模型内容要素。  相似文献