Braided composite materials for the production of lightweight, high rigidity golf shafts

Braiding is not currently used in the production of golf shafts. The objective of this work was to develop, through a modelling process consisting of altering lamina sequence, a golf shaft, using braided laminas, which would have mass, stiffness and torque comparable to commercially available composite and steel shafts. A 2D conical braided composite model was previously developed and validated to predict elastic constants of braided closed meshed structures. Energy methods were used to calculate the stiffness and torque of shafts using prescribed industry approaches. Shaft mass was calculated based on geometry and density of constitutent materials. Modelled shafts had both braided and unidirectional layers and compared favourably with or were better than commercially available composite and steel shafts in terms of deflection force and twist angle; they had the same weight as composite shafts but were much lighter than steel shafts. If these findings are verified, braided composites would be a viable and effective approach to the design of future golf shafts.     

In Physics Education,Perception Matters

Student difficulties in science learning are frequently attributed to misconceptions about scientific concepts. We argue that domain‐general perceptual processes may also influence students' ability to learn and demonstrate mastery of difficult science concepts. Using the concept of center of gravity (CoG), we show how student difficulty in applying CoG to an object such as a baseball bat can be accounted for, at least in part, by general principles of perception (i.e., not exclusively physics‐based) that make perceiving the CoG of some objects more difficult than others. In particular, it is perceptually difficult to locate the CoG of objects with asymmetric‐extended properties. The basic perceptual features of objects must be taken into account when assessing students' classroom performance and developing effective science, technology, engineering, and mathematics (STEM) teaching methods.     

Self-report vs. kinematic screening test: prevalence,demographics, and sports biography of yips-affected golfers

The yips is considered a task-specific movement disorder. Its estimated prevalence, however, is high compared to similar neurological movement disorders, possibly resulting from previous studies’ restriction of samples based on skill level, and self-report bias. Alternatively, this high prevalence might be an indication of additional aetiologies, for example the influence of previously played racket sports. We estimated the prevalence of the putting yips across the skill range, using self-reports in one study and a screening test in a second study. We explored if previously played sports matter for the development of the yips. In study 1, yips prevalence (N = 1,306) and golfers’ sports biographies (n = 264) were examined via two online surveys, in which golfers indicated if they were yips-affected. In study 2, golfers (N = 186) putted in a standardised putting test while kinematic and performance measures were recorded. Prevalence was estimated via a kinematic threshold. Sports biographies (n = 119) were obtained via an online survey. Prevalence of currently yips-affected golfers was 22.4% in study 1 and 16.7% in study 2. In both studies, more yips-affected than unaffected golfers had experience in playing racket sports. Yips prevalence remained higher than previously estimated prevalence of other movement disorders but decreased when the whole skill range including professionals and novices was considered. Future studies should use the kinematic screening test instead of self-reports to detect the yips and further investigate the influence of previously played racket sports.     

Impact of age on haematological markers pre- and post-marathon running

This study investigated whether haematological markers differ between young and masters marathon participants, running at similar performance levels. Nine young (31.89 ± 4.96 years) and eight masters (63.13 ± 4.61 years) runners participated. At five time points (pre-race through 54 h post-race), a complete blood cell count, basic metabolic panel and creatine kinase (CK) isoenzyme panel were assessed. Race performance was standardised using the World Masters Association Age Grading Performance Tables. Total CK levels were elevated for all participants at all time points post-race (P < 0.001). The CK-isoenzyme MB% was elevated across groups at 6, 30 and 54 h post-race (P < 0.01, P < 0.01 and P < 0.05), with masters runners having a higher CK-MB% at 30 and 54 h (P < 0.05, P < 0.05). Total white blood cell and neutrophil counts were elevated through 6 h post-race (P < 0.001), with higher levels found in younger runners (P < 0.001). When considering all blood work, masters runners had a higher number of abnormal values at 6, 30 and 54 h post-race (P < 0.05, P < 0.01 and P < 0.05). In conclusion, masters runners demonstrated sustained CK-MB elevation, which may suggest greater cardiac stress. However, future studies using additional cardiac markers should be completed to confirm these findings. In addition, masters runners showed an increased number of laboratory values outside normal range, indicating the body’s reduced capacity to respond to marathon running.     

Archives and Historians of Sport

Archives and the documents within them are at the heart of the practice of history and the occupational culture of historians. A majority of historical work has been characterized and defined by research in archives of varying kinds. Yet, the material within archives is both partial and political and using it is never straightforward. For historians of sport, the material available in archives can be especially limited but, with some careful reading between the lines, there is still much to learn from and interpret within traditional archives. This paper explores the different kinds of archives and archival material that historians of sport have used and the uses they have been and can be put to. Archives, however, are not static entities and the paper also discusses the impact and implication of digitization processes and programmes to popularize and legitimize traditional archives. Although sport has been seen as one of the ways of diversifying the content and audience of archives, the paper argues that the practical and interpretative challenges historians of sport face in archives are no different to those faced by other historians.     

Big and open linked data analytics ecosystem: Theoretical background and essential elements

Big and open linked data are often mentioned together because storing, processing, and publishing large amounts of these data play an increasingly important role in today's society. However, although this topic is described from the political, economic, and social points of view, a technical dimension, which is represented by big data analytics, is insufficient. The aim of this review article was to provide a theoretical background of big and open linked data analytics ecosystem and its essential elements. First, the key terms were introduced including related dimensions. Then, the key lifecycle phases were defined and involved stakeholders were identified. Finally, a conceptual framework was proposed. In contrast to previous research, the new ecosystem is formed by interactions of stakeholders in the following dimensions and their sub-dimensions: transparency, engagement, legal, technical, social, and economic. These relationships are characterized by the most important requisites and public policy choices affecting the data analytics ecosystem together with the key phases and activities of the data analytics lifecycle. The findings should contribute to relevant initiatives, strategies, and policies and their effective implementation.     

Partisan Patriotism in the American Presidency: American Exceptionalism,Issue Ownership,and the Age of Trump

This study employs issue ownership theory to examine the partisan dynamics surrounding the idea of American exceptionalism in presidential discourse. We conducted a content analysis of invocations of American exceptionalism in all major U.S. presidential addresses—domestic and foreign—from the end of World War II through Trump’s 1st year in office. We find that even though Republicans have traditionally claimed ownership of American exceptionalism, patterns in presidential discourse tell a very different story. Specifically, our results show (a) in domestic contexts, Republican and Democratic presidents were very similar in their invocations of American exceptionalism during the Cold War but that Democrats have held a substantial advantage over Republicans throughout the post–Cold War era, including on issue areas that Republicans are perceived to “own” (e.g. national security); (b) in foreign contexts, Democrats have been much more outspoken in their embrace of American exceptionalism throughout both the Cold War and post–Cold War; and (c) President Trump has diverged significantly, both in substance and frequency, from his Democratic and Republican predecessors in his invocation of American exceptionalism. We reflect on the implications of these findings on our broader understanding of issue—and trait—ownership, presidential discourse, and American exceptionalism in American politics.