The Art of Reason versus the Exactness of Science in Elite Refereeing: Comments on Plessner and Betsch (2001)

Plessner and Betsch’s (2001) investigation into officiating behavior may be representative of a shift from stress-orientated research (Anshel & Weinberg, 1995; Rainey & Winterich, 1995; Stewart & Ellery, 1996) to consideration of decisionmaking (Craven, 1998; Ford, Gallagher, Lacy, Bridwell & Goodwin, 1999; Oudejans, Verheijen, Bakker, Gerrits, Steinbuckner & Beek, 2000), the primary function of referees in any sport. Commendably, Plessner and Betsch have investigated the most important focus of referee performance, the application of the rules (Anshel, 1995). However, methodological weaknesses, together with a fundamental error in the attribution of causation to the findings, significantly dilute this paper’s contribution to extending knowledge in this important area

Elite Refereeing Performance:Developing a Modelfor Sport Science Support

To identify a framework for referee training and selection, based on the key areas of effective performance, we conducted content analyses on Rugby Football Union referee assessor reports, referee training materials, performance profiles from a group of English premier league referees, and a review of published research on sports officiating. The Cornerstones Performance Model of Refereeing emerged, overarched by the psychological characteristics of excellence (see McCaffrey & Orlick, 1989) and featuring four key areas; (a) knowledge and application of the law; (b) contextual judgment; (c) personality and management skills; and (d) fitness, positioning and mechanics. Focus group interviews confirmed the usefulness of the model as an assessment and training tool, which the RFU now use to develop referees throughout Englan

A Naturalistic Approach to Training Accurate and Coherent Decision Making in Rugby Union Referees

The purpose of this investigation was to pilot the use of a video-based training program designed to develop referees’ shared mental models. A group of English Rugby Football Union (RFU) national referees, divided into a control group (n = 15) and experimental group (n = 41) made their immediate decisions on pre and posttests of 10 video recordings taken from real game scenarios. Over a six-week period the experimental group studied training tapes consisting of 5 sets of 5 tackles, in each case with an expert providing his interpretation of the correct decision. Each clip was filmed from the referee’s perspective and taken from real game situations in order to maintain high ecological validity in accordance with naturalistic decision-making theory. The lowest ranked referees on the national panel significantly improved their percentage of correct decisions, becoming 17.43% more accurate in their decisions at the posttest. These results suggest that such shared mental model training is an appropriate method for improving referee decision making. \bb\164 words

Physical performance and decision making in association football referees: A naturalistic study.

Although researchers have independently investigated the physical and decision-making (DM) demands experienced by sports officials, the combined impact of locomotion and physiological factors upon DM has received little attention. Using an innovative combination of video and Global Positioning System (GPS) technology this study explored the movement, heart rate (HR) and DM of experienced football referees in their natural performance environment. A panel of independent referees analysed incidents (n = 144) taken from five referees in seven games in the New Zealand Football Championship (2005/06). The match-day referees made accurate decisions on 64% of the incidents, although their accuracy levels were not related to variables such as movement speed, HR, and cumulative distance covered. Interestingly, referees were on average only 51% accurate in the opening fifteen minutes of each half compared to 70% accuracy at all other times. This study demonstrated that it is possible to combine new emerging technologies to conduct a comprehensive study of naturalistic decision-making in sport

A molecular roadmap of the AGM region reveals BMP ER as a novel regulator of HSC maturation

In the developing embryo, hematopoietic stem cells (HSCs) emerge from the aorta-gonad-mesonephros (AGM) region, but the molecular regulation of this process is poorly understood. Recently, the progression from E9.5 to E10.5 and polarity along the dorso-ventral axis have been identified as clear demarcations of the supportive HSC niche. To identify novel secreted regulators of HSC maturation, we performed RNA sequencing over these spatiotemporal transitions in the AGM region and supportive OP9 cell line. Screening several proteins through an ex vivo reaggregate culture system, we identify BMP ER as a novel positive regulator of HSC development. We demonstrate that BMP ER is associated with BMP signaling inhibition, but is transcriptionally induced by BMP4, suggesting that BMP ER contributes to the precise control of BMP activity within the AGM region, enabling the maturation of HSCs within a BMP-negative environment. These findings and the availability of our transcriptional data through an accessible interface should provide insight into the maintenance and potential derivation of HSCs in culture.Peer reviewe

Physical activity, cardiorespiratory fitness, and metabolic syndrome in adolescents: A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>In adults, there is a substantial body of evidence that physical inactivity or low cardiorespiratory fitness levels are strongly associated with the development of metabolic syndrome. Although this association has been studied extensively in adults, little is known regarding this association in adolescents. The aim of this study was to analyze the association between physical activity and cardiorespiratory fitness levels with metabolic syndrome in Brazilian adolescents.</p> <p>Methods</p> <p>A random sample of 223 girls (mean age, 14.4 ± 1.6 years) and 233 boys (mean age, 14.6 ± 1.6 years) was selected for the study. The level of physical activity was determined by the Bouchard three-day physical activity record. Cardiorespiratory fitness was estimated by the Leger 20-meter shuttle run test. The metabolic syndrome components assessed included waist circumference, blood pressure, HDL-cholesterol, triglycerides, and fasting plasma glucose levels. Independent Student <it>t</it>-tests were used to assess gender differences. The associations between physical activity and cardiorespiratory fitness with the presence of metabolic syndrome were calculated using logistic regression models adjusted for age and gender.</p> <p>Results</p> <p>A high prevalence of metabolic syndrome was observed in inactive adolescents (males, 11.4%; females, 7.2%) and adolescents with low cardiorespiratory fitness levels (males, 13.9%; females, 8.6%). A significant relationship existed between metabolic syndrome and low cardiorespiratory fitness (OR, 3.0 [1.13-7.94]).</p> <p>Conclusion</p> <p>The prevalence of metabolic syndrome is high among adolescents who are inactive and those with low cardiorespiratory fitness. Prevention strategies for metabolic syndrome should concentrate on enhancing fitness levels early in life.</p

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease