Perceptual-cognitive skills in offside decision making: expertise and training effects

This two-experiment study aims to investigate the role of expertise in offside decision making (Experiment 1) and the effect of perceptual-cognitive training (Experiment 2). In Experiment 1, a video-based offside decision-making task followed by a frame recognition task demonstrated a bias toward flag errors and a forward memory shift for less-successful elite-standard assistant referees that is in line with the predictions from the flash-lag effect. In Experiment 2, an offside decision-making training program demonstrated a substantial progress from pre- to posttest for response accuracy, but not for accuracy of memory in the frame recognition task. In both experiments, no differences were found for visual scan patterns. First, these results suggest that less-successful elite-standard assistant referees are more affected by the flash-lag effect. Second, an off-field perceptual-cognitive training program can help assistant referees to deal with the perceptual consequences of the flash-lag illusion and to readjust their decision-making process accordingly.     

Hybrid clustering for validation and improvement of subject-classification schemes

A hybrid text/citation-based method is used to cluster journals covered by the Web of Science database in the period 2002–2006. The objective is to use this clustering to validate and, if possible, to improve existing journal-based subject-classification schemes. Cross-citation links are determined on an item-by-paper procedure for individual papers assigned to the corresponding journal. Text mining for the textual component is based on the same principle; textual characteristics of individual papers are attributed to the journals in which they have been published. In a first step, the 22-field subject-classification scheme of the Essential Science Indicators (ESI) is evaluated and visualised. In a second step, the hybrid clustering method is applied to classify the about 8300 journals meeting the selection criteria concerning continuity, size and impact. The hybrid method proves superior to its two components when applied separately. The choice of 22 clusters also allows a direct field-to-cluster comparison, and we substantiate that the science areas resulting from cluster analysis form a more coherent structure than the “intellectual” reference scheme, the ESI subject scheme. Moreover, the textual component of the hybrid method allows labelling the clusters using cognitive characteristics, while the citation component allows visualising the cross-citation graph and determining representative journals suggested by the PageRank algorithm. Finally, the analysis of journal ‘migration’ allows the improvement of existing classification schemes on the basis of the concordance between fields and clusters.     

Risk factors for overuse injuries in short- and long-distance running: A systematic review

Purpose:The aim of this study was to review information about risk factors for lower extremity running injuries in both short-distance(mean running distance-20 km/week and-10 km/session)and long-distance runners(mean running distance>20 km/week and>10 km/session).Methods:Electronic databases were searched for articles published up to February 2019.Prospective cohort studies using multivariable analysis for the assessment of individual risk factors or risk models for the occurrence of lower extremity running injuries were included.Two reviewers independently selected studies for eligibility and assessed risk of bias with the Quality in Prognostic Studies Tool.The GRADE approach was used to assess the quality of the evidence.Results:A total of 29 studies were included:17 studies focused on short-distance runners,11 studies focused on long-distance runners,and 1 study focused on both types of runners.A previous running-related injury was the strongest risk factor for an injury for long-distance runners,with moderate-quality evidence.Previous injuries not attributed to running was the strongest risk factor for an injury for short-distance runners,with high-quality evidence.Higher body mass index,higher age,sex(male),having no previous running experience,and lower running volume were strong risk factors,with moderate quality evidence,for short-distance runners.Low-quality evidence was found for all risk models as predictors of runningrelated injuries among short-and long-distance runners.Conclusion:Several risk factors for lower extremity injuries have been identified among short-and long-distance runners,but the quality of evidence for these risk factors for running-related injuries is limited.Running injuries seem to have a multifactorial origin both in short-and long-distance runners.     

Activity profile of top-class association football referees in relation to performance in selected physical tests

The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r(2) = 0.30; P < 0.05), the 200-m sprint (r(2) = 0.05; P < 0.05), or the 50-m sprint (r(2) = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.     

Risk factors for musculoskeletal injuries in elite junior tennis players: a systematic review

The objective was to systematically review the literature on risk factors and prevention programs for musculoskeletal injuries among tennis players. PubmedMedline, Embase, CINAHL, Cochrane, SportDiscus were searched up to February 2017. Experts in clinical and epidemiological medicine were contacted to obtain additional studies.

For risk factors, prospective cohort studies (n > 20) with a statistical analysis for injured and non-injured players were included and studies with a RCT design for prevention programs. Downs&Black checklist was assessed for risk of bias for risk factors. From a total of 4067 articles, five articles met our inclusion criteria for risk factors. No studies on effectiveness of prevention programs were identified. Quality of studies included varied from fair to excellent.

Best evidence synthesis revealed moderate evidence for previous injury regardless of body location in general and fewer years of tennis experience for the occurrence of upper extremity injuries. Moderate evidence was found for lower back injuries, a previous back injury, playing >6hours/week and low lateral flexion of the neck for risk factors. Limited evidence was found for male gender as a risk factor.

The risk factors identified can assist clinicians in developing prevention-strategies. Further studies should focus on risk factor evaluation in recreational adult tennis players.     

Major Survey Findings of Listening to MothersSM III: Pregnancy and Birth: Report of the Third National U.S. Survey of Women’s Childbearing Experiences

To understand the experiences and views of childbearing women in the United States and trends over time, Childbirth Connection carried out the third national Listening to Mothers survey among 2,400 women who gave birth in U.S. hospitals to a single baby from mid-2011 to mid-2012 and could participate in English. Harris Interactive conducted the survey using a validated methodology that includes data weighting to ensure that results closely reflect the target population. Results of the initial survey describe experiences from before pregnancy through the early postpartum period, and were reported in Listening to Mothers III: Pregnancy and Birth. A follow-up survey directed to the same participants explored postpartum experiences, attitudes about maternity care, and some additional pregnancy and birth items.     

Dimensional Stability and Moisture Properties of Gap-Fillers Based on Wood Powder and Glass Microballoons

ABSTRACT

Conservation of wooden objects exposed outdoors is extremely difficult and complex due to their constant exposure to fluctuating weather conditions and biological degradation. Filling the gaps in such objects requires the use of specific materials that in particular can adapt to changes in wood dimensions in response to humidity variations. Various materials have been used so far for filling voids in wooden artefacts but none of them was entirely suitable. Therefore, the authors have attempted to provide the basic characteristics of the selected commonly used filling materials based on pine wood powder or glass microballoons as fillers and Paraloid® B-72, Klucel® G, or glutin glue as binders, as the first step in research aiming at developing new and more appropriate gap-fillers. Special attention was paid to the dimensional stability of filling materials upon drying and exposure to water vapour and liquid water. The overall results indicate that among the examined fills those consisting of Paraloid® B-72 and glass microballoons revealed best properties as they were relatively dimensionally stable upon drying and exposure to moisture – despite high absorption of water – and were quite easy to finish. Generally, better properties were observed for filling materials containing higher concentrations of adhesives and these materials will be modified in the next step of the research. Since the main drawbacks of the examined gap-fillers were low water resistance, poor dimensional stability upon drying or exposure to water vapour or liquid water, and fragility or friability, future research into their modification will head towards improvement of the above-mentioned properties.     

Listening to Mothers II: Report of the Second National U.S. Survey of Women's Childbearing Experiences: Conducted January-February 2006 for Childbirth Connection by Harris Interactive(R) in partnership with Lamaze International

With permission from Childbirth Connection, the concise version of the Listening to Mothers II "Survey Methodology" is reprinted here. Harris Interactive(R) conducted Listening to Mothers II: Report of the Second National U.S. Survey of Women's Childbearing Experiences on behalf of Childbirth Connection. The survey consisted of 1,373 online interviews and 200 telephone interviews with women who had given birth in U.S. hospitals in 2005, with weighting of data to reflect the target population. Interviews were conducted from January 20 through February 21, 2006. The methods used to conduct the survey and analyze the data collected are described.     

An Introduction to Distributions Using Weighted Dice

This article describes a lively classroom demonstration that may be used to help develop students' understanding of the concept of a distribution, and to provide a foundation for the intuitive link between distributions and hypothesis testing.     

Rebels With a Cause? Adolescent Defiance From the Perspective of Reactance Theory and Self‐Determination Theory

The present investigation focused on adolescents' defiance against parents by drawing upon psychological reactance theory (Brehm, 1966) and self‐determination theory (Ryan & Deci, 2000). Psychological reactance would be elicited when freedom is taken away, thereby motivating individuals to engage in oppositional behavior. Throughout four studies (total N = 1,472, age ranging between 12 and 21 years), it was examined whether a controlling parenting style related to adolescents' experiences of autonomy need frustration (i.e., pressure) and reactance. Reactance, in turn, would relate to more externalizing and internalizing problems. Support was obtained for these associations in community and clinical samples, making use of different informants, and controlling for responsiveness and rule setting. A vignette‐based study provided further support. The discussion highlights theoretical and clinical implications.