2,412 research outputs found

    The referee's challenge: a threshold process model for decision making in sport games

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    Judgment and decision making in sporting officials is a challenging task that involves the use of context. Although process models of decision making describe decision contexts, none of the existing models explains when sports officials use rule-driven decision making, or game management. The basic idea of our work is that referees use a subjective threshold to apply game management, which may explain this decision behavior. We propose a new dynamic threshold model that is based on concepts derived from Decision Field Theory (Busemeyer & Townsend, 1993). The model includes two thresholds of game management (high/low) and two contact situations (foul/no foul) as approaching one of these thresholds. Using the example of soccer refereeing, we argue that if the game hits a subjective threshold of aggressive play, then the referee shifts from applying the rules to managing the game. This new approach changes the scientific discussion from one focused on what referees should decide in one situation or the other, to a dynamic model that explains the basic psychological mechanism underlying the referee’s change in behavior during the game, both at the intra-individual as well as inter-individual leve

    Arthropod Faunas of Monocultures and Polycultures in Reseeded Rangelands

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    Sap-feeding and predaceous arthropod faunas of forage bunchgrasses in reseeded rangeland vegetation were examined. Four major species of sap feeders were found; the major predators were spiders. Grass monoculture had very high densities of sap feeders compared with grass biculture, shrub-grass, tree-grass, and native areas; this was reflective of the large contribution from the mirids Irbisia brachycera Uhler and Conostethus americanus (Knight). They were present during the leaf stages of crested wheatgrass when it had its lowest carbohydrate root reserves. Homoptera and predator densities were not significantly related to the pattern of vegetation. The lowest number of sap-feeder species occurred in the grass monoculture, and sap-feeder faunas in this plot were dissimilar to those of all other plots. One-season dispersal experiments did not support the hypothesis that grass density caused the differences between arthropod faunas in different vegetation, whereas big sagebrush, common in reseeded pastures, repelled I. brachycera during short-term dispersal. The data indicate that reseeding to monocultures may result in high densities of Miridae during the leaf stages compared with moderate densities of Homoptera during the flower and seed stages in bicultures. The implications for pest management are discusse

    Obesity as a risk factor for COVID-19 mortality in women and men in the UK Biobank: comparisons with influenza/pneumonia and coronary heart disease

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    Obesity is associated with severe COVID-19 outcomes, yet, it unclear whether the risk of COVID-19 mortality associated with obesity is similar between the sexes. We used data from the UK Biobank to assess the risk of COVID-19 mortality associated with various anthropometric measures in women and men. To put these results in context, we also compared these estimates with those for mortality from influenza/pneumonia and coronary heart disease (CHD). The analyses included 502,493 individuals (54% women), of whom 410 (36% women) died of COVID-19, 549 (36% women) died of influenza/pneumonia, and 3355 (19% women) died of CHD. A higher BMI, waist circumference, waist-to-hip ratio, and waist-to-height ratio were each associated with a greater risk of death from COVID-19, influenza/pneumonia, and CHD in both sexes, with the exception of the association between higher BMI and the risk of influenza/pneumonia death in men. A higher BMI was associated with a stronger risk of COVID-19 mortality in women than men; the women-to-men ratio of hazard ratios was 1.20 (95% confidence interval: 1.00; 1.43). This study demonstrates the role of obesity in COVID-19 mortality and shows that the relative effects of a higher BMI on COVID-19 mortality may be stronger in women than men. This article is protected by copyright. All rights reserved

    BIOMECHANICAL INJURY PREDICTORS FOR MARATHON RUNNERS : STRIDING TOWARDS ILIOTIBIAL BAND SYNDROME INJURY PREVENTION

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    The purpose of this study was to prospectively analyze a large group of marathon runners (n=20) and test for biomechanical determinants of running injuries. The opportunity to prospectively follow runners of organized marathon training teams allowed for testing of the hypothesis that functional biomechanics may lead to iliotibial band syndrome (ITBS). Each runner was gait tested prior to developing any injuries. Injury predictors were generated by comparing those legs which eventually got ITBS injuries (n=7) with those legs that were injury free (n=33). Higher peak hip adduction moments (

    Does framing the hot hand belief change decision-making behavior in volleyball?

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    PURPOSE: Previous discussions of the hot hand belief, wherein athletes believe that they have a greater chance of scoring after 2 or 3 hits (successes) compared with 2 or 3 misses, have focused on whether this is the case within game statistics. Researchers have argued that the perception of the hot hand in random sequences is a bias of the cognitive system. Yet most have failed to explore the impact of framing on the stability of the belief and the behavior based on it. METHOD: The authors conducted 2 studies that manipulated the frame of a judgment task. In Study 1, framing was manipulated via instructions in a playmaker allocation paradigm in volleyball. In Study 2, the frame was manipulated by presenting videos for allocation decisions from either the actor or observer perspective. RESULTS: Both manipulations changed the hot hand belief and sequential choices. We found in both studies that the belief in continuation of positive or negative streaks is nonlinear and allocations to the same player after 3 successive hits are reduced. CONCLUSIONS: The authors argue that neither the hot hand belief nor hot hand behavior is stable, but rather, both are sensitive to decision frames. The results can inform coaches on the importance of how to provide information to athletes

    Associations of inflammatory and hemostatic variables with the risk of recurrent stroke

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    <p><b>Background and Purpose:</b> Several prospective studies have shown significant associations between plasma fibrinogen, viscosity, C-reactive protein (CRP), fibrin D-dimer, or tissue plasminogen activator (tPA) antigen and the risk of primary cardiovascular events. Little has been published on the associations of these variables with recurrent stroke. We studied such associations in a nested case-control study derived from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS).</p> <p><b>Methods:</b> Nested case-control study of ischemic (n=472) and hemorrhagic (n=83) strokes occurring during a randomized, placebo-controlled multicenter trial of perindopril-based therapy in 6105 patients with a history of stroke or transient ischemic attack. Controls were matched for age, treatment group, sex, region, and most recent qualifying event at entry to the parent trial.</p> <p><b>Results:</b> Fibrinogen and CRP were associated with an increased risk of recurrent ischemic stroke after accounting for the matching variables and adjusting for systolic blood pressure, smoking, peripheral vascular disease, and statin and antiplatelet therapy. The odds ratio for the last compared with the first third of fibrinogen was 1.34 (95% CI, 1.01 to 1.78) and for CRP was 1.39 (95% CI, 1.05 to 1.85). After additional adjustment for each other, these 2 odds ratios stayed virtually unchanged. Plasma viscosity, tPA, and D-dimer showed no relationship with recurrent ischemic stroke, although tPA was significant for lacunar and large artery subtypes. Although each of these variables showed a negative relationship with recurrent hemorrhagic stroke, none of these relationships achieved statistical significance.</p> <p><b>Conclusions:</b> Fibrinogen and CRP are risk predictors for ischemic but not hemorrhagic stroke, independent of potential confounders.</p&gt

    Prior events predict cerebrovascular and coronary outcomes in the PROGRESS trial

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    <p><b>Background and Purpose:</b> The relationship between baseline and recurrent vascular events may be important in the targeting of secondary prevention strategies. We examined the relationship between initial event and various types of further vascular outcomes and associated effects of blood pressure (BP)–lowering.</p> <p><b>Methods:</b> Subsidiary analyses of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS) trial, a randomized, placebo-controlled trial that established the benefits of BP–lowering in 6105 patients (mean age 64 years, 30% female) with cerebrovascular disease, randomly assigned to either active treatment (perindopril for all, plus indapamide in those with neither an indication for, nor a contraindication to, a diuretic) or placebo(s).</p> <p><b>Results:</b> Stroke subtypes and coronary events were associated with 1.5- to 6.6-fold greater risk of recurrence of the same event (hazard ratios, 1.51 to 6.64; P=0.1 for large artery infarction, P<0.0001 for other events). However, 46% to 92% of further vascular outcomes were not of the same type. Active treatment produced comparable reductions in the risk of vascular outcomes among patients with a broad range of vascular events at entry (relative risk reduction, 25%; P<0.0001 for ischemic stroke; 42%, P=0.0006 for hemorrhagic stroke; 17%, P=0.3 for coronary events; P homogeneity=0.4).</p> <p><b>Conclusions:</b> Patients with previous vascular events are at high risk of recurrences of the same event. However, because they are also at risk of other vascular outcomes, a broad range of secondary prevention strategies is necessary for their treatment. BP–lowering is likely to be one of the most effective and generalizable strategies across a variety of major vascular events including stroke and myocardial infarction.</p&gt

    Understanding the tectonic evolution of the West Orphan Basin, offshore Canada, and the conjugate Rockall Basin, offshore Ireland, using a seismic megatransect

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    The Orphan Basin, offshore Newfoundland, Canada, is approximately conjugate to the rifted margin basins on the Irish Atlantic margin. At the onset of seafloor spreading, plate reconstructions, based solely on oceanic magnetic anomalies, show the Rockall Basin, west of Ireland, forming a continuous Mesozoic basin with the West Orphan Basin. Here, the nature of this potentially continuous basin is examined through the development of a Newfoundland-Ireland conjugate basins model. 2D and 3D reconstructions of the West Orphan and Rockall basins yielded the thickness of the post-rift and syn-rift sedimentary packages, as well as the pre-rift crust. A discrepancy inspired additional analysis of the East Orphan Basin to aid in the reconstruction of the continuous Mesozoic basins. Based on the results of the reconstruction of the East Orphan Basin, it is possible that the Rockall Basin was originally conjugate to, and continuous with, the East Orphan Basin
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