Expected Pass Turnovers (xPT) - a model to analyse turnovers from passing events in football.

The aim of this study was to create a novel metric, Expected Pass Turnovers (xPT), that could evaluate possession retention from player-passing events in football. Event and positional data were analysed from all 380 matches in the 2020/21 English Premier League season, which encompassed 256,433 passes in the final dataset. A logistic mixed-effects model was implemented to attribute the probability of each pass getting turned over. The use of positional data enabled the identification of a) opposition players present in radii surrounding the ball carrier and b) availability of teammates with respect to the ball carrier. The addition of these positional features improved the accuracy (+6.1 AUC Score) of the model. xPT serves as a practitioner Key Performance Indicator, as analysts can identify players that lose possession more often or not than expected, given the situational context of each pass, from game to game. Future work may include modelling the turnover probability of dribble and carry actions, as this would lead to a more comprehensive understanding of turnover events in football.

An economic valuation of federal and private grazing land ecosystem services supported by beef cattle ranching in the United States.

Beef cattle ranching and farming is a major agricultural industry in the United States that manages an estimated 147 million ha of private land and uses approximately 92% of forage authorized for grazing on federal rangelands. Rangelands, as working landscapes, sustain beef cattle ranching while providing habitat for wildlife, recreation, and open space amenities, as well as spiritual and cultural values that define a way of life. Historically, discussions regarding the economics of beef cattle ranching have focused primarily on the value of beef production but have more recently expanded to consider related ecosystem services. A systematic search of peer-reviewed literature published between 1998 and 2018 found 154 articles that considered ecosystem services from rangelands/grasslands. Of these, only two articles (1%) provided an in-depth economic valuation (monetary measure) of ecosystem services in the United States. To fill this knowledge gap, we primarily used publicly available data to conduct an economic valuation of major ecosystem services associated with beef cattle production in the United States at both the national and state levels. We find that over 186 million ha were actively grazed by beef cattle ranches and farms in the United States in 2017. We estimate the economic value of this land use to be $17.5 billion for wildlife recreation, $3.8 billion for forage production, and $3.2 billion for other ecosystem services related to the conservation of biodiversity-a combined total of $24.5 billion. Ecosystem services from federal rangelands in 16 western states accounted for 35% of the total value. Ecosystem services per beef cow and per kilogram of retail beef were estimated to be $1,043.35 and $2.74, respectively. More studies like these are needed to inform decision-makers at the industry, land management, and federal levels to ensure that the conservation, improvement, and restoration of these ecosystem services are considered in future management and research efforts.

The within-match patterns of locomotor efficiency during professional soccer match play: Implications for injury risk?

OBJECTIVES: The principle aim of the current study was to examine within-match patterns of locomotor efficiency in professional soccer, determined as the ratio between tri-axial accelerometer data (PlayerLoad™) and locomotor activities. Between match variability and determinants of PlayerLoad™ during match play were also assessed. DESIGN: A single cohort, observational study. METHODS: Tri-axial accelerometer data (PlayerLoad™) was recorded during 86 competitive soccer matches in 63 English championship players (574 match observations). Accelerometer data accumulated (PlayerLoad Vector Magnitude [PLVM]) from the individual-component planes of PlayerLoad™ (anterior-posterior PlayerLoad™ [PLAP], medial-lateral PlayerLoad™ [PLML] and vertical PlayerLoad™ [PLV]), together with locomotor activity (Total Distance Covered [TDC]) were determined in 15-min segments. Locomotor efficiency was calculated using the ratio of PLVM and TDC (PlayerLoad™ per metre). The proportion of variance explaining the within-match trends in PLVM, PLAP, APML, APv, and TDC was determined owing to matches, individual players, and positional role. RESULTS: PLVM, PLAP, APML, APv and TDC reduced after the initial 15-min match period (p=0.001; η(2)=0.22-0.43, large effects). PL:TDC increased in the last 15min of each half (p=0.001; η(2)=0.25, large effect). The variance in PLVM during soccer match-play was explained by individual players (63.9%; p=0.001) and between-match variation (21.6%; p=0.001), but not positional role (14.1%; p=0.364). CONCLUSIONS: Locomotor efficiency is lower during the latter stages of each half of competitive soccer match-play, a trend synonymous with observations of increased injury incidence and fatigue in these periods. Locomotor efficiency may be a valuable metric to identify fatigue and heightened injury risk during soccer training and match-play.

The pathogenesis of human cytomegalovirus.

Human cytomegalovirus (HCMV) is a recognized cause of disease in the fetus, the allograft recipient and AIDS patients. More recently, it has been recognized as a pathogen for those admitted to intensive care units, for the elderly and for the general population. The epidemiology and molecular and cellular pathology of this virus are summarized to provide an overarching model of pathogenesis, able to account for these varying clinical presentations. In brief, HCMV has the potential to spread in the bloodstream to all organs, but only produces overt disease if the viral load increases to high levels. This is normally prevented by a robust immune response, so that the infected individual usually remains asymptomatic. However, this benefit comes at the cost of committing more and more immunological resources to controlling HCMV with time, so that the overall function of the immune system is impaired. Fortunately, recent progress in developing novel antiviral drugs and vaccines suggests the possibility that the diverse effects of HCMV may soon become controllable at the individual and population level, respectively.