A topography of free kicks in soccer     

Daniel Link  Otto Kolbinger  Hendrik Weber  Michael Stöckl 《Journal of sports sciences》2016,34(24):2312-2320

ABSTRACT

This study investigates the spatial relationship of performance variables for soccer free kicks. In order to suggest ways in which players might optimise their performance, we collected data from free kicks (<35 m to goal line) of two German Bundesliga seasons (2013/14, 2014/15) (n = 1624). In the analysis, we applied the ISO-map approach using colour gradients to visualise the mean values of a variable on a 2D-map of the pitch. Additionally, variograms were used to describe the degree of spatial dependence of the free kick variables. Results show that DENSITY, TYPE OF PLAY, PLAYERS IN WALL, DISTANCE TO WALL and RULE VIOLATION were strongly spatially dependent. Centrality and proximity to the goal increased the variables PLAYERS IN WALL, RULE VIOLATIONS and INTERRUPTION TIME, and the ratio of goals scored increased from 5.9% (central far) to 10.9% (central near). In 70.9% of the shots, players preferred a switched laterality, which did not result in a higher success rate. Furthermore, there was no statistical advantage for the defensive team when DISTANCE TO WALL was below 9.15 m or when there was a RULE VIOLATION. Crosses had a success rate (i.e., first controlled ball contact after the cross) of 20.8%. Played with natural laterality, they were 5% more successful than with switched laterality. Crosses from the right side outside the penalty box were 10% more successful than from the left side. Therefore, it might be worthwhile practising the defence of balls coming from this side.  相似文献   

Physiological profile of a professional boxer preparing for Title Bout: A case study     

Israel Halperin  Steven Hughes  Dale W Chapman 《Journal of sports sciences》2016,34(20):1949-1956

This study aimed to (1) profile a professional boxer (23 years and 80 kg) with boxing-specific, muscle function, aerobic capacity and body composition tests, and (2) quantify how these measures varied during an 8-week preparation phase leading to, and post a state-Title Bout fought in the 76.2-kg class. A series of boxing-specific and muscle function tests were completed on 11 occasions: 9 prior and twice after the bout, each separated by approximately 2 weeks. The boxing test included 36 maximal punches (9 of each: lead and rear straights, lead and rear hooks) to a punching integrator measuring forces and velocity. Muscle function tests included countermovement jump, drop-jumps, isometric mid-thigh pull and isometric bench-press. Body composition was assessed using skin-fold measurements on three occasions and one dual energy X-ray absorptiometry scan. Aerobic capacity was assessed using 2 VO₂ max tests. Leading up to the bout, performance decreased in isometric mid-thigh pull (8%), isometric bench-press (5%), countermovement jump (15%) and impact forces in 3 of 4 punches (4%–7%). Whereas measures of dynamic and isometric muscle function remained depressed or unchanged post competition, punching forces (6%–15%) and aerobic power (6%) increased. Data suggest the athlete may have super-compensated following rest as fatigue dissipated and further adaptation occurred.  相似文献   

The effects of physical contact type on the internal and external demands during a rugby league match simulation protocol     

Jonathan P. Norris  Jamie Highton  Stephen F. Hughes  Craig Twist 《Journal of sports sciences》2016,34(19):1859-1866

The aim of this study was to investigate how the type of contact influences physiological, perceptual and locomotive load during a simulated rugby league match. Eleven male university rugby league players performed two trials of the rugby league movement simulation protocol for interchange forwards with a traditional soft tackle bag and a weighted tackle sled to replicate contact demands. The interchange forward-specific simulation was chosen given the contact frequency is higher for this group of players compared to whole match players. Locomotive rate, sprint speed, tackle intensity, heart rate (HR) and rating of perceived exertion were analysed during the first and second bouts that replicated two ~23 min on-field passages. Countermovement jump (CMJ) was measured before and immediately after each trial. More time was spent in heart rate zone between 91 and 100% HR_peak during the first (effect size ± 90% confidence interval: 0.44 ± 0.49) and second bouts (0.44 ± 0.43), and larger (0.6 ± 0.69) decrements in CMJ performance were observed during the sled trial (5.9, s = 4.9%) compared to the bag trial (2.6, s = 5.4%). Changing the type of contact during the match simulation subtly altered both the internal and external loads on participants. Using a standard tackle bag results in faster sprint speed to contact, but lower overall high-intensity running. Conversely, a heavier tackle object increases the internal load and results in greater lower limb neuromuscular fatigue as reflected by the decrease in CMJ performance.  相似文献   

真正的天堂     

高素菊 《海外英语》2007,(3):40-41

你说的那个地方是不是有金子铺的街道和珍珠做的门? 不, 那是地狱。一个人带着他的狗在路上边走边欣赏风景, 突然, 他想起来自己已经死了。他记得他死了, 而且狗也死了几年了。他不知道这条路会把他们带到哪里。  相似文献   

Teaching and research: Rapport or mesalliance     

Michael A. Faia 《Research in higher education》1976,4(3):235-246

In America, the problem has persisted for at least a century: Are teaching and research mutually supportive, or do they tend to detract from one another? The empirical literature (due largely to measurement problems) provides an ambiguous answer, although the more recent studies have produced fairly consistently negative results. Role complementarity may depend on a range of social structural conditions, such as time allocation, whether or not roles are highly specialized, and the values around which roles are organized. In addition, the process of “compensatory selection” may reduce role complementarity as teacher/researchers move through their careers. Data for this study suggest that teaching and research tend to be mutually supportive, especially at schools where research is not emphasized.  相似文献   

Reassessing the People's Choice: Revisiting a Classic and Excavating Lessons for Research About Media and Voting     

Stephen Lacy  Michael Stamm 《Mass Communication and Society》2016,19(2):105-126

This article reassesses The People's Choice by Paul Lazarsfeld, Bernard Berelson, and Hazel Gaudet, one of the foundations of communication and voting behavior research. As with most classics, which are often cited but seldom read, we believe this book has much to teach contemporary social scientists. We return to the original context of the research and use voting data from the period with three broad goals: (a) to find ideas and lessons from this work that generally have been overlooked, (b) to suggest new ways of applying these ideas, and (c) to encourage scholars to engage more with this seminal work to understand ideas that are often overlooked when a complex piece of research is reduced to a brief discussion or passing citation.  相似文献   

Walter Lippmann’s Ghost: An Interview With Michael Schudson     

Michael Schudson 《Mass Communication and Society》2016,19(3):221-229

An esteemed scholar conducts an enlightening examination of the enduring issues of the press as a democratic institution, the professionalization of the journalist, journalism schools, liberalism, and science. This imagined one-on-one conversation with Walter Lippmann is lightly humorous yet offers important insights on the accountability of the government by the press in days gone by and on the accountability of the press to the public in our digital age.  相似文献   

Humanitas Emptor: Reconsidering Recent Trends and Policy in Science Teacher Education     

Dana L. Zeidler  Benjamin C. Herman  Michael P. Clough  Joanne K. Olson  Sami Kahn  Mark Newton 《Journal of Science Teacher Education》2016,27(5):465-476

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Academic socialization,parental educational expectations,and academic self‐efficacy among Latino adolescents     

Fernanda L. Cross  Aixa D. Marchand  Michael Medina  Andrea Villafuerte  Deborah Rivas‐Drake 《Psychology in the schools》2019,56(4):483-496

This study examined the direct association between parental educational expectations and adolescents’ academic self‐efficacy, as well as the moderating influence of parental academic socialization messages. Participants were 148 Latino parent–adolescent dyads with the majority of Mexican origin (80.4%). Most of the parent participants were mothers (85.8%). Adolescents were 13 (46%) or 14 (54%) years of age, and 53% identified as female. Adolescents reported their academic self‐efficacy and perceptions of their parents’ educational expectations; parents reported on their academic socialization messages of shame/pressure and effort regarding academics. The results suggest that, after accounting for parents’ level of education and immigrant status, parental educational expectations were positively associated with adolescent academic self‐efficacy. This association was stronger among adolescents whose parents reported transmitting fewer messages of shame/pressure and academic effort. These results point to the importance of nuances in the content and type of academic socialization messages within Latino families.  相似文献   

Modelling quality     

Michael Christie  Hetty Grunefeld  Gerda Thibautt 《European Journal of Engineering Education》2001,26(4):441-450

This article argues that the increase in the number of teaching and learning centres in universities of technology in recent years is bound up with concerns about the quality of university education. Universities that have set up such centres have been motivated to do so for two main reasons. They are keen to improve the image and the capacity of their teaching faculty. They also hope to attract students at a time when many school leavers prefer immediate, well-paid employment to four or more years of study. There has been outside pressure as well. Governments have demanded that tertiary institutions become more accountable. Governments are insisting that taxpayers get value for their money, especially in the area of teaching and learning. The question asked in this article is whether or not teaching and learning centres should be modelling quality issues as well as teaching and learning issues. Our conclusion is that the centres should be proactive in this matter, providing their institution with both theoretical and practical models of quality management and assurance.  相似文献