Time to embrace the complexity when analysing GPS data? A systematic review of contextual factors on match running in rugby league

ABSTRACT

This systematic review aimed to identify and summarise associations between currently identified contextual factors and match running in senior male professional rugby league. Eligible articles included at least one contextual factor and used GPS to measure at least one displacement variable within competitive senior, male, professional rugby league matches. Of the 15 included studies, the identified contextual factors were grouped into factors related to individual characteristics (n = 3), match result (n = 4), team strength (n = 2), opposition strength (n = 3), match conditions (n = 6), technical and tactical demands (n = 6), spatial and temporal characteristics (n = 7), and nutrition (n = 1). Speed was the most commonly reported measure of match running (100%), followed by distance (47%), and acceleration (20%). Inconsistencies were found between studies for most contextual factors on match running. Higher speeds were generally associated with higher fitness, encountered earlier in the match and whilst defending. All 15 studies utilised a univariate approach to quantify associations of a contextual factor. The inconsistencies found in the associations of given contextual factors highlight the complex and multi-faceted nature of match running. Therefore, practitioners should consider contextual factors when analysing and interpreting GPS data.     

Experimental determination of the flame temperatures of complex mixtures of combustible gases and a method for calculating them

The flame temperatures of mixtures of hydrogen, or methane, or carbon monoxide containing various amounts of nitrogen and carbon dioxide, with air, have been determined. The flame temperatures of a number of complex mixtures of combustible gases and industrial gases have also been determined. A method of calculating the maximum flame temperature of any mixed gas is described. Good agreement is found between the calculated and determined temperatures of the gases used in this investigation.     

如何在网上挣外快

当今社会是一个信息化的时代,电脑逐渐成为每家每户不可或缺的"伙伴"。除了将电脑作为休闲娱乐的工具之外,我们也可以利用它得天独厚的优势赚取外快。本文将向读者介绍一些实用的网络赚钱方法。     

Developing writing skills of learners with persistent literacy difficulties through explicit grammar teaching

The benefits of grammar instruction in the teaching of writing is contested in most English‐speaking countries (Jones et al., 2012). The majority of Anglophone countries abandoned the teaching of grammar in the 1950s based on the conclusions that it had no positive impact on learners’ development of reading, writing and language (Locke, 2005). Through an action research design, this study aims at gaining a further understanding of how the explicit teaching of grammar in context can benefit learners with persistent literacy difficulties by adapting the Grammar for Writing materials (Myhill, 2013). It intends to improve educational practice (Koshy, 2010) through action, analysis and reflection.