Timescales for exploratory tactical behaviour in football small-sided games     

Angel Ric  Robert Hristovski  Bruno Gonçalves  Lorena Torres  Jaime Sampaio  Carlota Torrents 《Journal of sports sciences》2016,34(18):1723-1730

The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players’ tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.  相似文献   

Motorische Leistungsfähigkeit von Kindern und Jugendlichen in Deutschland     

C. Albrecht  A. Hanssen-Doose  K. Bös  L. Schlenker  S. Schmidt  M. Wagner  N. Will  A. Worth 《Sportwissenschaft》2016,46(4):294-304

Motor performance is an important health resource. Review articles revealed a decline of motor performance of approximately 10?% between 1975 and 2006. In the past most of the data available for such comparisons came from ad hoc studies with non-standardized methods. Within the framework of the ”Motorik-Modul“ (MoMo) study as part of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), it is possible for the first time to directly compare two cohorts in the ages of 4–17 years in a nationally representative database for Germany. The aim of this article is to report changes in motor performance of children and adolescents in the time period 2003–2006 (cohort baseline n = 4528) compared to 2009–2012 (cohort wave 1, n = 2820). Overall, it is clearly shown that the motor performance of children and adolescents in Germany did not decrease within the observational period of 6 years. The comparison of mean values of the baseline cohort compared to those of wave 1 showed that 28 out of 52 mean values of the two cohorts with a high probability did not differ based on 95?% confidence intervals (CI). In 24 out of the 52 mean values positive changes could be noted based on the individual 95?% CI values. There were more positive changes in primary school aged children than in other age groups. Within these positive changes, most effect sizes were small to medium. The results indicate that recent activities aiming at elevating motor performance levels may have started to make an impact and should be expanded, also in secondary schools. The comparative cohort study presented in this article is currently being checked by the ongoing MoMo wave 2 survey of 2014–2017.  相似文献   

Perceived health problems in swimmers according to the chemical treatment of water in swimming pools     

Álvaro Fernández-Luna  Pablo Burillo  José Luis Felipe  Julio del Corral  Jorge García-Unanue  Leonor Gallardo 《European Journal of Sport Science》2016,16(2):256-265

The objective of this study was to determine which chemical treatment used for disinfecting water in indoor swimming pools had the least impact on users' perceptions of health problems, and which generated the greatest satisfaction with the quality of the water. A survey on satisfaction and perceived health problems was given to 1001 users at 20 indoor swimming pools which used different water treatment methods [chlorine, bromine, ozone, ultraviolet lamps (UV) and salt electrolysis]. The findings suggest that there is a greater probability of perceived health problems, such as eye and skin irritation, respiratory problems and skin dryness, in swimming pools treated with chlorine than in swimming pools using other chemical treatment methods. Pools treated with bromine have similar, although slightly better, results. Other factors, such as age, gender, time of day of use (morning and afternoon) and type of user (competitive and recreational), can also affect the probability of suffering health problems. For all of the above, using combined treatment methods as ozone and UV, or salt electrolysis produces a lower probability of perceived health problems and greater satisfaction.  相似文献   

Lower limb alignment characteristics are not associated with running injuries in runners: Prospective cohort study     

Luiz Carlos Hespanhol Junior  Aline Carla Araújo de Carvalho  Leonardo Oliveira Pena Costa 《European Journal of Sport Science》2016,16(8):1137-1144

There is conflicting evidence on the association between lower limb alignment characteristics and the incidence of running-related injury (RRI). Therefore, the primary aim of this study was to investigate the association between lower limb alignment characteristics and the incidence proportion of RRI in a convenience sample of recreational runners. A total of 89 recreational runners were included in this prospective cohort study. These participants had been running for at least six months and were injury-free at baseline. Lower limb alignment measurements were conducted in order to calculate lower limb discrepancy, Q-angle, subtalar angle and plantar index. All participants also answered a baseline and biweekly online surveys about their running routine, history of RRI and newly developed RRI over a period of 12 weeks. The prevalence of previous RRI and the 12-week incidence proportion of new RRI were calculated. Logistic regression analysis was performed to estimate the association between lower limb length discrepancy, Q-angle, subtalar angle and plantar ach index with the incidence proportion of RRI. The prevalence of previous RRI was 55.1% (n?=?49). The 12-week incidence proportion of new RRI was 27.0% (n?=?24). Muscle injuries and tendinopathies were the main types of RRI identified. The lower leg and the knee were the main anatomical regions affected. We did not find significant associations between lower limb length discrepancy, Q-angle, subtalar angle and plantar arch index and injury occurrence.  相似文献   

Many choices,one destination: multimodal university brand construction in an urban public transportation system     

Gerardo Blanco Ramírez 《International journal of qualitative studies in education》2016,29(2):186-204

Amidst global competition in higher education, colleges and universities adopt strategies that mimic and adapt business practices. Branding is now a widespread practice in higher education; multimodal advertisement is a manifestation of emerging branding strategies for universities. While the visibility of brands in higher education has grown substantially in recent years, its empirical study has lagged. This article reports on the findings from a study that employed social semiotic and multimodal analysis to explore text and visual rhetoric as brand construction strategies in publicly displayed university advertisements. After analyzing photographs representing advertising campaigns from 16 different universities displayed in an urban public transportation system, I suggest that universities construct their brand identity through messages that emphasize multiple choices and convenience, but construct success primarily according to corporate standards and values.  相似文献   

Equality and excellence. Hegemonic discourses of economisation within the German education system     

Tobias Peter  Ulrich Bröckling 《International Studies in Sociology of Education》2017,26(3):231-247

Looking to conflicting constitutions of education systems through the terms equality and excellence, this paper examines the discursive formation of two political rationalities in the contemporary German education system. While early childhood and primary education discourses are dominated by a terminology of equality, tertiary education institutions such as universities are described using a terminology of excellence that has become a reference point for political interventions and institutional reform processes. Drawing from hegemony theory, governmentality studies and systems theory, this paper analyses the rules of justification referred to by such hegemonic discourses. It presents a policy discourse analysis of strategic, conceptional and institutional texts produced between 2003 and 2010. Through this analysis, the paper suggests that ‘mobilising’ and ‘optimising’ represent the common principles of equality and excellence as economic rationalities.  相似文献   

Art,Culture and Citizenship in Social Projects in Brazil     

Santo  Denise Espírito 《Prospects》2002,32(4)

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José Pedro Varela     

Marta Demarchi  Hugo Rodríguez 《Prospects》1994,24(3-4):703-718

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Do all roads really lead to Rome? The case of spelling acquisition     

Daigle  Daniel  Berthiaume  Rachel  Costerg  Agnès  Plisson  Anne  Ruberto  Noémia  Varin  Joëlle 《Reading and writing》2020,33(2):313-328

The French orthographic code is complex, and its acquisition is laborious (Catach, 2008; Fayol & Jaffré, 2008). Three hypotheses attempt to explain orthographic knowledge acquisition (OKA). For some, exposure to the code leads to OKA through a self-learning process (Share, 2004). For others, OKA benefits from graphophonological processes (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). Finally, some authors suggest that OKA is possible thanks to visual specific processes (Ans, Carbonnel, & Valdois, 1998). The main goal of this study was to test these hypotheses in a classroom context with comparable samples. In total, 143 2nd-grade children participated in this quasi-experimental study with a pretest, immediate posttest, and delayed posttest design. We assigned participants to one of four conditions. For three conditions, we created three teaching procedures based on each of the hypotheses: frequency of contacts with target words; explicit teaching of graphophonological properties of words; explicit teaching of visual properties of words. The fourth served as a control group. ANOVA analyses indicated that all three experimental conditions favored OKA, showing that the different teaching procedures led to spelling development. However, the visual condition was the most favorable. Three main conclusions can be drawn from this study: (a) models of OKA should account for the different paths that can lead to spelling acquisition; (b) visual properties of words and their acquisition need additional research, and (c) applied research in real classroom contexts is not only relevant for informing teaching practices but also for better understanding how learning takes place.

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The Experience of the Teaching Expedition and Teacher Networks: New Modes of Training?     

Unda  María Pilar 《Prospects》2002,32(3)

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