New physics searches at the BESIII experiment     

Shenjian Chen  Stephen Lars Olsen 《国家科学评论(英文版)》2021,8(11)

The standard model (SM) of particle physics, comprised of the unified electroweak and quantum chromodynamic theories, accurately explains almost all experimental results related to the micro-world, and has made a number of predictions for previously unseen particles, most notably the Higgs scalar boson, that were subsequently discovered. As a result, the SM is currently universally accepted as the theory of the fundamental particles and their interactions. However, in spite of its numerous successes, the SM has a number of apparent shortcomings, including: many free parameters that must be supplied by experimental measurements; no mechanism to produce the dominance of matter over antimatter in the universe; and no explanations for gravity, the dark matter in the universe, neutrino masses, the number of particle generations, etc. Because of these shortcomings, there is considerable incentive to search for evidence for new, non-SM physics phenomena that might provide important clues about what a new, beyond the SM theory (BSM) might look like. Although the center-of-mass energies that BESIII can access are far below the energy frontier, searches for new, BSM physics are an important component of its research program. This report reviews some of the highlights from BESIII’s searches for signs of new, BSM physics by: measuring rates for processes that the SM predicts to be forbidden or very rare; searching for non-SM particles such as dark photons; performing precision tests of SM predictions; and looking for violations of the discrete symmetries C and CP in processes for which the SM expectations are immeasurably small.  相似文献   

French DNCG management control versus UEFA Financial Fair Play: a divergent conception of financial regulation objectives     

Nadine Dermit-Richard  Stephen Morrow 《Soccer & Society》2019,20(3):408-430

The French Football Federation was the first football governing body to put in place, in 1990, a financial regulation system. It might be expected that UEFA’s Financial Fair Play (FFP) system established in 2010 would be similar to French DNCG (National Direction for Management Control) regulations. However, while FFP is concerned with profitability, DNCG is focused on solvency. Hence, a French club may be loss-making and not compliant with FFP, while at the same time being solvent in accordance with DNCG rules. Our research confirms that most French clubs do not conform to FFP rules. As such, it provides further evidence that DNCG has not prevented poor financial management within French clubs. The coexistence of DNCG and FFP– or any other domestic financial regulation and FFP –may result in disparities between domestic clubs. As a consequence, there should be consistent financial regulation in all European leagues.  相似文献   

The biomechanical characteristics of high-performance endurance running     

Stephen J. Preece  Christopher Bramah  Duncan Mason 《European Journal of Sport Science》2019,19(6):784-792

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.  相似文献   

Considerations for the use of functional principal components analysis in sports biomechanics: examples from on-water rowing     

John Warmenhoven  Stephen Cobley  Conny Draper  Andrew Harrison  Norma Bargary  Richard Smith 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):317-341

The proliferation of new biomechanical technology in laboratory and field settings facilitates the capture of data-sets consisting of complex time-series. An understanding of the appropriate statistical approaches for analysing and interpreting these data-sets is required and the functional data analysis (FDA) family of statistical techniques has emerged in the biomechanical literature. Given the use of FDA is currently in its infancy with biomechanical data, this paper will form the first of a two part series aiming to address practical issues surrounding the application of FDA techniques in biomechanics. This work focuses on functional principal components analysis (fPCA), which is explored using existing literature and sample data from an on-water rowing database. In particular methodological considerations for the implementation of fPCA such as temporal normalisation of data, removal of unwanted forms of variation in a data-set and documented methods for preserving the original temporal properties within a set of curves are explored in detail as a part of this review. Limitations and strengths of the technique are outlined and recommendations are provided to encourage the appropriate use of fPCA within the field of applied sports biomechanics.  相似文献   

How to use—and create—criterion checklists     

Stephen L. Yelon 《Performance Improvement》1984,23(3):1-4

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An investigation of oral language and writing proficiency in third-grade students     

Rebecca Edmaiston  Stephen C. Larsen 《Psychology in the schools》1983,20(3):380-387

Over the years, professionals have hypothesized that a positive relationship exists between children's oral language proficiency and their written language performance. This study examined the following two aspects of the relationship between oral and written language: (a) Are specific linguistic components of language more closely related than others? (b) Do groups rated high, medium, or low on written language measures differ significantly in oral language proficiency? Measures of oral and written language were administered to 77 third-grade students. Results indicated that moderate relationships existed between grammatical aspects of oral and written language. Oral language proficiency was significantly different for groups rated high, medium, and low on the basis of written language performance.  相似文献   

The impact of training on company productivity levels     

Stephen J. Holoviak 《Performance Improvement》1982,21(5):6-8

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Patricia Gallagher (1954–2021)     

Stephen J. Greenberg 《Journal of the Medical Library Association》2022,110(2):264

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The National Joker: Abraham Lincoln and the Politics of Satire Todd Nathan Thompson. Carbondale: Southern Illinois University Press, 2015.          下载免费PDF全文

Stephen Curley 《Journal of American culture (Malden, Mass. : 2003)》2016,39(4):478-478

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‘Salk Hops’: Teen Health Activism and the Fight against Polio, 1955 – 1960     

Stephen E. Mawdsley 《Cultural and Social History》2016,13(2):249-265

In the late 1950s, a health charity, known as the National Foundation for Infantile Paralysis (March of Dimes), organized American teens into volunteer divisions to fight polio, as well as tame adult anxieties surrounding juvenile delinquency. The alliance that developed permitted the NFIP to increase its influence and revenue, while granting teens an opportunity to assert their cultural power and challenge negative stereotypes. Although the NFIP nurtured and at times dominated the relationship, young volunteers joined for their own reasons and shaped the program to suit their own aspirations and interests.  相似文献