Sprint kayaking and canoeing performance prediction based on the relationship between maturity status,anthropometry and physical fitness in young elite paddlers     

Daniel López-Plaza  Fernando Alacid  José María Muyor  Pedro Ángel López-Miñarro 《Journal of sports sciences》2017,35(11):1083-1090

This study aimed to identify the maturity-related differences and its influence on the physical fitness, morphological and performance characteristics of young elite paddlers. In total, 89 kayakers and 82 canoeists, aged 13.69 ± 0.57 years (mean ± s), were allocated in three groups depending on their age relative to the age at peak height velocity (pre-APHV, circum-APHV and post-APHV) and discipline (kayak and canoe). Nine anthropometric variables, a battery of four physical fitness tests (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20 m multistage shuttle run test) and three specific performance tests (1000, 500 and 200 m) were assessed. Both disciplines presented significant maturity-based differences in all anthropometric parameters (except for fat and muscle mass percentage), overhead medicine ball throw and all performance times (pre > circum > post; P < 0.05). Negative and significant correlations (P < 0.01) were detected between performance times, chronological age and anthropometry (body mass, height, sitting height and maturity status), overhead medicine ball throw and sit and reach for all distances. These findings confirm the importance of maturity status in sprint kayaking and canoeing since the more mature paddlers were also those who revealed largest body size, physical fitness level and best paddling performance. Additionally, the most important variables predicting performance times in kayaking and canoeing were maturity status and chronological age, respectively.  相似文献   

A new footwear technology to promote non-heelstrike landing and enhance running performance: Fact or fad?     

Janet H. Zhang  Aislinn J. C. McPhail  Winko W. An  Waqar M. Naqvi  Daniel L. H. Chan  Ivan P. H. Au 《Journal of sports sciences》2017,35(15):1533-1537

This study sought to compare the kinetics and kinematics data in a group of habitual shod runners when running in traditional running shoes and newly designed minimalist shoes with lug platform. This novel footwear design claims to simulate barefoot running and reduce energy loss during impact. We compared footstrike angle (FSA), vertical average (VALR) and instantaneous (VILR) loading rates, energy loss and initial vertical stiffness between two shoe conditions. Runners demonstrated a decreased FSA while running in minimalist shoes with lug platform than traditional shoes (P = 0.003; Cohen’s d = 0.918). However, we did not observe a landing pattern transition. VALR and VILR between two footwear conditions showed no significant difference (P = 0.191–0.258; Cohen’s d = 0.304–0.460). Initial vertical stiffness (P = 0.032; Cohen’s d = 0.671) and energy loss (P = 0.044; Cohen’s d = 0.578) were greater when running in minimalist shoes with lug platform. The results show that minimalist shoes with lug platform reduce the FSA but may not lead to a landing pattern switch or lower vertical loading rates. Interestingly, the new shoe design leads to a greater energy loss than traditional running shoes, which could be explained by a higher initial vertical stiffness.  相似文献   

Hot-Heads,Gentlemen and the Liberties of Tradesmen     

Daniel Johnson 《Cultural and Social History》2013,10(3):343-364

Abstract

Over the summer and autumn of 1739 Philadelphia’s two newspapers published competing versions of a hearing in the Pennsylvania assembly that was described as the ‘Affair of the Tanners’. What began as a minor property dispute in the colonial assembly became, with the aid of the local press, a citywide paper war for the support of the urban populace. This article argues the affair provides unique evidence for competing conceptions of the common good in the eighteenth-century colonial city, and was an expression of conflict with deep roots in Philadelphia’s history. The affair also shows how the medium of print could reflect both transatlantic cultural processes as well as distinctly local grievances, as a group of prosperous city artisans and their opponents utilized the city’s newspapers to articulate competing commonwealth ideologies.  相似文献   

Comfort,Class and Climate Change: The Rise of Glass in Late Medieval and Early Modern Domestic Architecture     

Daniel Jütte 《Cultural and Social History》2013,10(5):621-641

ABSTRACT

In the modern world, glass windows are considered an indispensable element of the built environment. Throughout premodern times, however, glass was not universally used in European architecture. This article argues that the rise of glass in Western architecture was neither an inevitable nor a linear process, but rather a response to certain social, cultural and environmental factors that gained increasing relevance from the late medieval period onwards. In other words, glass windows are a cultural convention, reflecting some of the wide-ranging and transformative challenges that Europeans faced in the late medieval and early modern period.  相似文献   

Annual report of the mechanical and engineering section for 1901     

Daniel Eppelshimer 《Journal of The Franklin Institute》1902,153(2):156-157

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The antiquity of the art of paper making     

R. Daniel 《Journal of The Franklin Institute》1830,10(4):267-269

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Description of a new process of stereotype moulds; with notices of the history and results of the processes of stereotyping     

Daniel Wilson  LL.D  F.S.A.  Scot V.P. 《Journal of The Franklin Institute》1838

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Accelerated aging test for weighted silk     

WM.D. Appel  Daniel A. Jessup 《Journal of The Franklin Institute》1935,220(6):793-794

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Game management, context effects, and calibration: the case of yellow cards in soccer     

Unkelbach C  Memmert D 《运动与训练心理学杂志》2008,30(1):95-109

Referees in German first-league soccer games do not award as many yellow cards in the beginning of a game as should be statistically expected. One explanation for this effect is the concept of game management (Mascarenhas, Collins, & Mortimer, 2002). Alternatively, the consistency model (Haubensak, 1992) explains the effect as a necessity of the judgment situation: Referees need to calibrate a judgment scale, and, to preserve degrees of freedom in that scale, they need to avoid extreme category judgments in the beginning (i.e., yellow cards). Experiment 1 shows that referees who judge scenes in the context of a game award fewer yellow cards than referees who see the same scenes in random order. Experiment 2 shows the combined influence of game management (by explicitly providing information about the game situation) and calibration (early vs. late scenes in the time course of a game). Theoretical implications for expert refereeing and referee training are discussed.  相似文献   

Starting with a clean slate: An analysis of member identification with a new sports team     

Daniel Lock  Simon Darcy  Tracy Taylor 《Sport Management Review》2009,12(1):15-25

Soccer in Australia underwent a series of changes following a Federal Government inquiry into its future. A report into the Structure, Governance and Management of Soccer in Australia (2003) recommended a process of structural change, aimed at repositioning and re-branding soccer as association football. The restructure yielded the replacement of the National Soccer League with the A-League, five new Australian teams and a concerted attempt to separate soccer from its ethnic ties in the antipodes. This paper examines member identification in relation to a specific A-League club’s members. Using the Sports Spectator Identity Scale (Wann & Branscombe, 1993) to measure sport fan identity in a new team context, a survey of club members of Sydney FC (n = 510), was undertaken. Survey findings indicated that members of Sydney FC reported relatively strong team identification in the first year of the new competition, with some nuanced differences based on age and income. The SSIS demonstrated a good level of fit in relation to a new sports team, although it is evident that rivalries and identification with a new team need time to develop fully.  相似文献