Increasing plantarflexion angle during landing reduces vertical ground reaction forces,loading rates and the hip’s contribution to support moment within participants     

K. Michael Rowley  James G. Richards 《Journal of sports sciences》2015,33(18):1922-1931

The ankle joint’s role in shock absorption during landing has been researched in many studies, which have found that landing with higher amounts of plantarflexion (PF) results in lower peak vertical ground reaction forces and loading rates. However, there has not yet been a study that compares drop landings within participants along a quantitative continuum of PF angles. Using a custom-written real-time feedback program, participants adjusted their ankles to an instructed PF angle and dropped onto two force platforms. For increasing PF, peak ground reaction force and peak loading rate during weight acceptance decreased significantly. The hip’s contribution to peak support moment decreased as PF at initial contact increased up to 30°. The ankle and knee contributions increased over this same continuum of PF angles. There appears to be no optimal PF angle based on peak ground reaction force and loading rate measurements, but there may be an optimum where joint contributions to peak support moment converge and the hip moment’s contribution is minimised.  相似文献   

Impact of age on haematological markers pre- and post-marathon running     

Thomas G. Martin  Rachel W. Pata  Johanna D’Addario  Lauren Yuknis  Rebecca Kingston  Richard Feinn 《Journal of sports sciences》2015,33(19):1988-1997

This study investigated whether haematological markers differ between young and masters marathon participants, running at similar performance levels. Nine young (31.89 ± 4.96 years) and eight masters (63.13 ± 4.61 years) runners participated. At five time points (pre-race through 54 h post-race), a complete blood cell count, basic metabolic panel and creatine kinase (CK) isoenzyme panel were assessed. Race performance was standardised using the World Masters Association Age Grading Performance Tables. Total CK levels were elevated for all participants at all time points post-race (P < 0.001). The CK-isoenzyme MB% was elevated across groups at 6, 30 and 54 h post-race (P < 0.01, P < 0.01 and P < 0.05), with masters runners having a higher CK-MB% at 30 and 54 h (P < 0.05, P < 0.05). Total white blood cell and neutrophil counts were elevated through 6 h post-race (P < 0.001), with higher levels found in younger runners (P < 0.001). When considering all blood work, masters runners had a higher number of abnormal values at 6, 30 and 54 h post-race (P < 0.05, P < 0.01 and P < 0.05). In conclusion, masters runners demonstrated sustained CK-MB elevation, which may suggest greater cardiac stress. However, future studies using additional cardiac markers should be completed to confirm these findings. In addition, masters runners showed an increased number of laboratory values outside normal range, indicating the body’s reduced capacity to respond to marathon running.  相似文献   

‘The Product of the Town Itself’: Community Representation and the Stanley Cup Hockey Challenges of the Kenora Thistles, 1903–1907     

Stacy L. Lorenz 《国际体育史杂志》2015,32(17):2078-2106

This case study of community representation in Canadian hockey analyzes media accounts of four Stanley Cup hockey series played by the Kenora Thistles between 1903 and 1907. It examines newspaper coverage of the Thistles hockey club as it moved from an amateur team represented by players with roots in their home community to a professional aggregation that included paid imports from outside the town. The essay explores the relationship between sport and civic identity during a key time of change in top-level hockey. The dominant narrative surrounding the Thistles portrayed players as true ‘members’ of the town of Kenora. Even after the turn to professionalism, narratives of small-town, amateur purity and close connections to the community characterized coverage of the Thistles as they pursued the Stanley Cup. At the same time, however, a growing emphasis on securing the personnel that could ensure victory led to praise for the club’s efforts to please its supporters, or ‘customers’. As a result, this study of notions of civic representation in early hockey provides insight into the process by which sports teams came to be viewed as symbolic representatives of their communities.  相似文献   

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes     

A. Zaher  S. Li  K. T. Wolf  F. N. Pirmoradi  O. Yassine  L. Lin  N. M. Khashab  J. Kosel 《Biomicrofluidics》2015,9(5)

Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices'' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.  相似文献   

Core-shell hydrogel beads with extracellular matrix for tumor spheroid formation     

L. Yu  S. M. Grist  S. S. Nasseri  E. Cheng  Y.-C. E. Hwang  C. Ni  K. C. Cheung 《Biomicrofluidics》2015,9(2)

Creating multicellular tumor spheroids is critical for characterizing anticancer treatments since they may provide a better model of the tumor than conventional monolayer culture. Moreover, tumor cell interaction with the extracellular matrix can determine cell organization and behavior. In this work, a microfluidic system was used to form cell-laden core-shell beads which incorporate elements of the extracellular matrix and support the formation of multicellular spheroids. The bead core (comprising a mixture of alginate, collagen, and reconstituted basement membrane, with gelation by temperature control) and shell (comprising alginate hydrogel, with gelation by ionic crosslinking) were simultaneously formed through flow focusing using a cooled flow path into the microfluidic chip. During droplet gelation, the alginate acts as a fast-gelling shell which aids in preventing droplet coalescence and in maintaining spherical droplet geometry during the slower gelation of the collagen and reconstituted basement membrane components as the beads warm up. After droplet gelation, the encapsulated MCF-7 cells proliferated to form uniform spheroids when the beads contained all three components: alginate, collagen, and reconstituted basement membrane. The dose-dependent response of the MCF-7 cell tumor spheroids to two anticancer drugs, docetaxel and tamoxifen, was compared to conventional monolayer culture.  相似文献   

Informing in-season tactical periodisation in team sport: development of a match difficulty index for Super Rugby     

Samuel J. Robertson  David G. Joyce 《Journal of sports sciences》2015,33(1):99-107

In team sports, tactical periodisation refers to the planned manipulation of training loads with the aim of prioritising athlete readiness for matches of greatest importance. Although monitoring of athletes’ physical condition is often used to inform this planning, the direct influence of external factors on match difficulty has not been well quantified. In this study, a ‘match difficulty index’ (MDI) for use in Super Rugby was developed, based on the influence imparted by five external factors on previous match outcomes. Specifically, information relating to match location, days break between matches, time-zone change and opposition ladder position (both current and previous year) were collected for matches played during the 2011–2013 Super Rugby seasons. Logistic regression analyses were used to assess the importance of each of these factors with respect to match outcome (win/loss), with opposition ladder position and match location (home, domestic away or international) exerting the greatest influence on match difficulty. Three separate cross-validated models were constructed, with match outcome classification performance reported as 66.2%, 65.5% and 63.7% respectively. The three MDI models emanating from this study can each be used to inform tactical periodisation program design both prior to and during the regular season.  相似文献   

心的中心地位:道家之间的论战     

达格拉斯·贝格美 《商丘师范学院学报》2015,(2):29-33

心与身体其他感觉器官的关系问题,备受先秦两汉所有重要思想流派的争议。众所周知,传统儒家认为心是主"情"的器官,并具有分析其他感官之间差异的能力1。对于孟子来说,"四端"学说就是关于"心"的内容,最为显著的是恻隐之心,它能促进人们德性的成长2。对于儒家来说,与其他自然的感觉器官相比,"心"是较为高级的。因为它不仅具有思考的能力,而且能评估人们所遇之事;而其他感知器官,仅仅是在于接触其他事物3。"心"比其  相似文献   

发展中国家研究型大学的作用:引领国家和全球知识经济发展     

菲利普·G·阿特巴赫  胡颖 《大学教育科学》2015,1(1)

研究型大学是各国学术系统的核心部分.研究型大学的发展可以推动各国知识经济的成功.国际顶尖期刊的编辑、作者和评阅人都来自研究型大学,同时,研究型大学能够获取全球知识信息,汇聚各类学者团体,资助教师参与国际专业学术机构和国际会议,并位于互联网革命的中心,因此,开展国际学术知识交流和参与到国际学术网络中是发展中国家研究型大学的核心使命.研究型大学作为“知识的仓库”和“批判中心”,面临着全球化带来的机遇和挑战.在高等教育国际化进程中,发展中国家的研究型大学面临着语言的困境,并且亟需改善学术职业的条件.从卓越的研究型大学的典型特征来分析,各国应该思考如何改善研究型大学的基础设施和智力氛围以使其迈向成功.  相似文献   

CRP,but not TNF-α or IL-6, decreases after weight loss in patients with morbid obesity exposed to intensive weight reduction and balneological treatment     

Danuta Ro??  Przemys?aw Adamczyk  Joanna Boinska  Robert Szafkowski  Irena Ponikowska  Katarzyna Stankowska  Barbara Góralczyk  Barbara Ruszkowska-Ciastek 《Journal of Zhejiang University. Science. B》2015,16(5):404-411

  相似文献   

Library as a Partner in Co-Designing Learning Spaces: A Case Study at Tampere University of Technology,Finland     

Johanna Tevaniemi  Jenni Poutanen  Riitta Lähdemäki 《New Review of Academic Librarianship》2015,21(3):304-324

This article presents a case of co-designed temporary learning spaces at a Finnish academic library, together with the results of a user-survey. The experimental development of the multifunctional spaces offered an opportunity for the library to collaborate with its parent organisation thus broadening the role of the library. Hence, library can be seen as a third player facilitating learning spaces. Additionally, the library's own expertise was strengthened through successful cooperation with the undergraduate students and other actors. The results support prior research, where studying in the library is target-oriented differing from other learning spaces in providing support and resources.  相似文献