1,315 research outputs found
Examining the Relationship Between Throwing Injuries Sustained in Adolescent Baseball Players and Use of an Injury Prevention Smartphone Application Throw Like a Pro
Objective: To describe the use rate of the injury prevention smartphone app “Throw Like a Pro” (TLP), and determine the relationship between use of the app and throwing injuries in adolescent baseball players.
Design and Setting: The smartphone application TLP was distributed to adolescent baseball players. Instruction was given on correct use of the application. Stretches, exercises, and application features were demonstrated to subjects. Data on use and injuries was compiled through self-reported surveys.
Subjects: A convenience sample of adolescent baseball players (n=20) aged 13-18 from the Babe Ruth Little League organization in Missoula, Montana were selected.
Measurements: A modified Kerlan-Jobe Orthopedic Clinic demographic questionnaire was collected on participants including age, current/previous history of shoulder or elbow injury, and years of playing experience. Self-reported surveys collected data pertaining to use of the smartphone application TLP and throwing injuries sustained during the baseball season.
Results: Thirty-nine separate time point responses were obtained from participants. Forty-one percent of total responses (n=16/39) revealed shoulder or elbow pain during the season. This is representative of national averages for adolescent baseball players. Athletes who stretched 3-4 times per week experienced less pain than athletes who did not. Pitchers who followed recommended rest periods saw a decreased likelihood of shoulder or elbow pain when compared to pitchers who did not follow recommended rest periods.
Conclusions: The incidence rate of overuse injuries in adolescent baseball players is rising. Many rehabilitative exercises post-injury exist, however preventative approaches are lacking. This research reveals the importance of both using pitch count to decrease likelihood of shoulder or elbow pain, as well as the need for ways to increase compliance among athletes. Further research is needed on the use of smartphone applications as a viable source of treatment protocol and injury prevention
Статические нагрузки упругих зубьев зубчатых передач
Представим себе изготовленную из упругих материалов, статистически нагружен-ную
зубчатую передачу, состоящую из двух зацепляющихся колес и обладающую не-точностями в
нормальном шаге зацепления, характеризуемыми погрешностью α01 . В этом случае для
соблюдения условий уравнения (1), сохранения постоянства угловых перемещений при
вращении и обеспечения непрерывности зубьев, обладающих раз-личными размерами
нормального шага зацепления, потребуется соответствующая сум-марная упругая
деформация, вызванная передаваемым удельным крутящим моментом Mn1, будет
эквивалентна величине углового перемещени
How should we measure psychological resilience in sport performers?
Psychological resilience is important in sport because athletes must constantly withstand a wide range of pressures to attain and sustain high performance. To advance psychologists’ understanding of this area, there exists an urgent need to develop a sport-specific measure of resilience. The purpose of this paper is to review psychometric issues in resilience research and to discuss the implications for sport psychology. Drawing on the wider general psychology literature to inform the discussion, the narrative is divided into three main sections relating to resilience and its assessment: adversity, positive adaptation, and protective factors. The first section reviews the different ways that adversity has been measured and considers the potential problems of using items with varying degrees of controllability and risk. The second section discusses the different approaches to assessing positive adaptation and examines the issue of circularity pervasive in resilience research. The final section explores the various issues related to the assessment of protective factors drawing directly from current measures of resilience in other psychology sub-disciplines. The commentary concludes with key recommendations for sport psychology researchers seeking to develop a measure of psychological resilience in athletes
The changing landscape : ecosystem responses to urbanization and pollution across climatic and societal gradients
Author Posting. © Ecological Society of America, 2008. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 6 (2008): 264–272, doi:10.1890/070147.Urbanization, an important driver of climate change and pollution, alters both biotic and abiotic ecosystem properties within, surrounding, and even at great distances from urban areas. As a result, research challenges and environmental problems must be tackled at local, regional, and global scales. Ecosystem responses to land change are complex and interacting, occurring on all spatial and temporal scales as a consequence of connectivity of resources, energy, and information among social, physical, and biological systems. We propose six hypotheses about local to continental effects of urbanization and pollution, and an operational research approach to test them. This approach focuses on analysis of “megapolitan” areas that have emerged across North America, but also includes diverse wildland-to-urban gradients and spatially continuous coverage of land change. Concerted and coordinated monitoring of land change and accompanying ecosystem responses, coupled with simulation models, will permit robust forecasts of how land change and human settlement patterns will alter ecosystem services and resource utilization across the North American continent. This, in turn, can be applied globally.We thank the NSF LTER program for its support
Applications of patching to quadratic forms and central simple algebras
This paper provides applications of patching to quadratic forms and central
simple algebras over function fields of curves over henselian valued fields. In
particular, we use a patching approach to reprove and generalize a recent
result of Parimala and Suresh on the u-invariant of p-adic function fields, for
p odd. The strategy relies on a local-global principle for homogeneous spaces
for rational algebraic groups, combined with local computations.Comment: 48 pages; connectivity now required in the definition of rational
group; beginning of Section 4 reorganized; other minor change
Cellular location and activity of Escherichia coli RecG proteins shed light on the function of its structurally unresolved C-terminus
RecG is a DNA translocase encoded by most species of bacteria. The Escherichia coli protein targets branched DNA substrates and drives the unwinding and rewinding of DNA strands. Its ability to remodel replication forks and to genetically interact with PriA protein have led to the idea that it plays an important role in securing faithful genome duplication. Here we report that RecG co-localises with sites of DNA replication and identify conserved arginine and tryptophan residues near its C-terminus that are needed for this localisation. We establish that the extreme C-terminus, which is not resolved in the crystal structure, is vital for DNA unwinding but not for DNA binding. Substituting an alanine for a highly conserved tyrosine near the very end results in a substantial reduction in the ability to unwind replication fork and Holliday junction structures but has no effect on substrate affinity. Deleting or substituting the terminal alanine causes an even greater reduction in unwinding activity, which is somewhat surprising as this residue is not uniformly present in closely related RecG proteins. More significantly, the extreme C-terminal mutations have little effect on localisation. Mutations that do prevent localisation result in only a slight reduction in the capacity for DNA repair. © 2014 The Author(s)
A Rapid Gamma-Ray Glow Flux Reduction Observed From 20 km Altitude
Two gamma-ray glows were observed by a high-altitude NASA ER-2 aircraft flying at 20 km altitude over a thunderstorm in Colorado, USA. The flux of the first glow rapidly intensified and then abruptly decreased within a few tens of milliseconds. On a timescale of seconds, the flux decrease occurred simultaneously with a hybrid intra-cloud/cloud-to-ground lightning discharge beneath the aircraft. However, a more detailed analysis of the discharge dynamics indicated that the discharge activity was unusually calm during the actual period of the flux decrease. The lightning was observed with on-board antennas, optical sensor, and ground-based lightning mapping and location networks. Its closest activity was 12 km away from the aircraft, below and slightly ahead the course. The gamma-ray flux reduction happened roughly in the middle of the lightning development process. The glow spectral analysis for the periods of a weak and strong flux enhancement has been done. The spectra were found to be background-like and similar to each other.publishedVersio
Evolution of the One CGIAR’s research and innovation portfolio to 2030 : approaches, tools, and insights after the reform
In this perspective, we offer insights into the evolution of CGIAR’s research and innovation portfolio from 2019 to 2023, underpinning the transformative journey towards One CGIAR. With this contribution, we aim to strengthen the social and environmental sustainability components of allied, future Research for Development (R4D) portfolios. We explore three interlinked operational frameworks—Quality of Research for Development (QoR4D), Comparative Advantage (CA) Analysis, and Inclusive Innovation—and present practical tools and lessons for enhancing the quality and impact of R4D initiatives. This work is based on insights gained by the Independent Science for Development Council (ISDC) during the review of proposals for the current One CGIAR research portfolio. QoR4D’s four dimensions (relevance, scientific credibility, legitimacy, and effectiveness) guide research strategy, portfolio development, evaluation and performance standards, fostering intentional design and transparent assessment. CA Analysis leverages organisational strengths, facilitating purposeful partnerships, and strategic resource allocation. Inclusive Innovation emphasises stakeholder inclusivity, amplifying legitimacy, relevance, and effectiveness. Insights are drawn from the application of these frameworks, highlighting the importance of collaboration, the need for a mindset shift and institutional reform, specialisation, and impact maximisation. By adopting these lessons, CGIAR and allied organisations can collectively address global food system challenges more effectively, driving sustainable agricultural innovation and societal transformation. This article aims to contribute to advancing sustainable agriculture and underscores the significance of systemic collaborations in creating more resilient and equitable food systems.Publisher PDFPeer reviewe
Strongyloses ratti and S. stercoralis: effects of cambendazole, thiabendazole and mebendazole in vitro
The effects of in vitro incubation of three henzimidazole anthelmintics, thiabendazole, mebendazole and cambendazole on Strongyloides were compared. No drug affected hatching of S. ratti eggs or the viability of infective larvae or parasitic adult worms, but all three inhibited moulting of S. ratti larvae. In addition, cambendazole, but not thiabendazole or mebendazole, impaired the viability of S. ratti first- and second-stage larvae. The three drugs had no effect on isolated S. stercorais free-living adult worms, but they all prevented development of S. stercoralis rhabditiform larvae. Thiabendazole and mebendazole had no effect on the infectivity of either S. ratti or S. stercoralis infective larvae, but infection with these worms was abrogated by prior incubation with cambendazole. These results indicate that cambendazole acts in a different manner to the other two drugs. Since it is active against larvae migrating through the tissues, it is potentially of much greater value than thiabendazole or mebendazole in the therapy of strongyloidiasis
Blood pressure variability and cardiovascular risk in the PROspective study of pravastatin in the elderly at risk (PROSPER)
Variability in blood pressure predicts cardiovascular disease in young- and middle-aged subjects, but relevant data for older individuals are sparse. We analysed data from the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study of 5804 participants aged 70–82 years with a history of, or risk factors for cardiovascular disease. Visit-to-visit variability in blood pressure (standard deviation) was determined using a minimum of five measurements over 1 year; an inception cohort of 4819 subjects had subsequent in-trial 3 years follow-up; longer-term follow-up (mean 7.1 years) was available for 1808 subjects. Higher systolic blood pressure variability independently predicted long-term follow-up vascular and total mortality (hazard ratio per 5 mmHg increase in standard deviation of systolic blood pressure = 1.2, 95% confidence interval 1.1–1.4; hazard ratio 1.1, 95% confidence interval 1.1–1.2, respectively). Variability in diastolic blood pressure associated with increased risk for coronary events (hazard ratio 1.5, 95% confidence interval 1.2–1.8 for each 5 mmHg increase), heart failure hospitalisation (hazard ratio 1.4, 95% confidence interval 1.1–1.8) and vascular (hazard ratio 1.4, 95% confidence interval 1.1–1.7) and total mortality (hazard ratio 1.3, 95% confidence interval 1.1–1.5), all in long-term follow-up. Pulse pressure variability was associated with increased stroke risk (hazard ratio 1.2, 95% confidence interval 1.0–1.4 for each 5 mmHg increase), vascular mortality (hazard ratio 1.2, 95% confidence interval 1.0–1.3) and total mortality (hazard ratio 1.1, 95% confidence interval 1.0–1.2), all in long-term follow-up. All associations were independent of respective mean blood pressure levels, age, gender, in-trial treatment group (pravastatin or placebo) and prior vascular disease and cardiovascular disease risk factors. Our observations suggest variability in diastolic blood pressure is more strongly associated with vascular or total mortality than is systolic pressure variability in older high-risk subjects
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