Block height influences the head depth of competitive racing starts

The purpose of this study was to determine whether or not starting block height has an effect on the head depth and head speed of competitive racing starts. Eleven experienced, collegiate swimmers executed competitive racing starts from three different starting heights: 0.21 m (pool deck), 0.46 m (intermediate block), and 0.76 m (standard block). One-way repeated measures ANOVA indicated that starting height had a significant effect on the maximum depth of the center of the head, head speed at maximum head depth, and distance from starting wall at maximum head depth. Racing starts from the standard block and pool deck were significantly deeper, faster, and farther at maximum head depth than starts from the intermediate block. There were no differences between depth, speed, or distance between the standard block and pool deck. We conclude that there is not a positive linear relationship between starting depth and starting height, which means that starts do not necessarily get deeper as the starting height increases

Competitive swimmers modify racing start depth upon request

To expand upon recent findings showing that competitive swimmers complete significantly shallower racing starts in shallower pools, 12 more experienced and 13 less experienced swimmers were filmed underwater during completion of competitive starts. Two starts (1 routine and 1 “requested shallow”) were executed from a 0.76 m block height into water 3.66 m deep. Dependent measures were maximum head depth, head speed at maximum head depth, and distance from the starting wall at maximum head depth. Statistical analyses yielded significant main effects (p < 0.05) for both start type and swimmer experience. Starts executed by the more experienced swimmers were deeper and faster than those executed by the less experienced swimmers. When asked to dive shallowly, maximum head depth decreased (0.19 m) and head speed increased (0.33 ms-1) regardless of experience. The ability of all swimmers to modify start depth implies that spinal cord injuries during competitive swimming starts are not necessarily due to an inherent inability to control the depth of the start

Racing start safety: head depth and head speed during competitive starts into a water depth of 1.22 m

From the perspective of swimmer safety, there have been no quantitative 3-dimensional studies of the underwater phase of racing starts during competition. To do so, 471 starts were filmed during a meet with a starting depth of 1.22 m and block height of 0.76 m. Starts were stratified according to age (8 & U, 9–10, 11–12, 13–14, and 15 & O) and stroke during the first lap (freestyle, breaststroke, and butterfly). Dependent measures were maximum head depth, head speed at maximum head depth, and distance from the wall at maximum head depth. For all three variables, there were significant main effects for age, F(4, 456) = 12.53, p < .001, F(4, 456) = 27.46, p < .001, and F(4, 456) = 54.71, p < .001, respectively, and stroke, F(2, 456) = 16.91, p < .001, F(2, 456) = 8.45, p < .001, and F(2, 456) = 18.15, p < .001, respectively. The older swimmers performed starts that were deeper and faster than the younger swimmers and as a result, the older swimmers may be at a greater risk for injury when performing starts in this pool depth

Start depth modification by adolescent competitive swimmers

To expand upon previous studies showing inexperienced high school swimmers can complete significantly shallower racing starts when asked to start “shallow,” 42 age group swimmers (6-14 years old) were filmed underwater during completion of competitive starts. Two starts (one normal and one “requested shallow”) were executed from a 0.76 m block into 1.83 m of water. Dependent measures were maximum depth of the center of the head, head speed at maximum head depth, and distance from the starting wall at maximum head depth. Statistical analyses yielded significant main effects (p < 0.05) for start type and age. The oldest swimmers’ starts were deeper and faster than the youngest swimmers’ starts. When asked to start shallowly, maximum head depth decreased (0.10 m) and head speed increased (0.32 ms-1) regardless of age group. The ability of all age groups to modify start depth implies that spinal cord injuries during competitive swimming starts are not necessarily due to age-related deficits in basic motor skills

Water depth influences the head depth of competitive racing starts

Recent research suggests that swimmers perform deeper starts in deeper water (Blitvich, McElroy, Blanksby, Clothier, & Pearson, 2000; Cornett, White, Wright, Willmott, & Stager, 2011). To provide additional information relevant to the depth adjustments swimmers make as a function of water depth and the validity of values reported in prior literature, 11 collegiate swimmers were asked to execute racing starts in three water depths (1.53 m, 2.14 m, and 3.66 m). One-way repeated measures ANOVA revealed that the maximum depth of the center of the head was significantly deeper in 3.66 m as compared to the shallower water depths. No differences due to water depth were detected in head speed at maximum head depth or in the distance from the wall at which maximum head depth occurred. We concluded that swimmers can and do make head depth adjustments as a function of water depth. Earlier research performed in deep water may provide overestimates of maximum head depth following the execution of a racing start in water depth typical of competitive venues

Racing start safety: head depth and head speed during competitive backstroke starts

Research on competitive swim start safety has focused on starts involving a dive from above the water surface. The purpose of this study was to determine the depths, speeds, and distances attained when executing backstroke starts, which begin in the water, and to investigate whether or not these variables are a function of age. Backstroke starts (n = 122) performed in 1.22 m of water during competition were stratified according to age group (8&U, 9-10, 11-12, 13-14, and 15&O). Dependent measures were maximum depth of the center of the head (MHD), head speed at maximum head depth (SPD), and distance from the wall at maximum head depth (DIST). Main effects were shown for age group for MHD (F = 8.86, p < 0.05), SPD (F = 4.64, p < 0.05), and DIST (F = 17.21, p < 0.05). Because they performed starts that were deeper and faster than the younger swimmers, the older swimmers seem to be at a greater risk for injury when performing backstroke starts in shallow water

Racing start safety: head depth and head speed during competitive swim starts into a water depth of 2.29m

The head depths and head speeds of swimmers attained following the execution of racing starts during competition have not been well described. To address this, 211 competitive starts were filmed into a starting depth of 2.29 m with a block height of 0.76 m. Starts were stratified according to age, sex, stroke, and swim meet. Dependent measures were maximum depth of the center of the head, head speed at maximum head depth, and distance from the wall at maximum head depth. Significant main effects existed for age for all three measures: F(1, 106) = 13.33, p < .001, F(1, 106) = 18.60, p < .001 and F(1, 106) = 70.59, p < .001, respectively. There was a significant age by sex interaction, F(1, 106) = 5.36, p = 0.023, for head speed. In conclusion, older swimmers performed starts that were deeper and faster than younger swimmers and nearly all starts exceeded the threshold speeds for injury. As compared to starts previously reported into 1.22 m, starts were deeper, slower, and farther from the starting wall at maximum head depth

Collaborating between Writing and STEM: Teaching Disciplinary Genres, Researching Disciplinary Interventions, and Engaging Science Audiences

Collaborating between Writing and STEM: Teaching Disciplinary Genres, Researching Disciplinary Interventions, and Engaging Science Audiences This poster describes a multi-pronged effort to build a writing curriculum in Physics and other STEM fields at the George Washington University, USA. These efforts include curricular collaboration, a research study conducted by the Physicists and Writing Scholars, and external funding initiatives. This project first began as a curricular collaboration through our Writing in the Disciplines (WID) curriculum, initiated by observations among Physics faculty that undergraduate students lack Physics specific writing skills. Writing faculty responded to this observation by introducing Physics faculty to the idea that writing can and must be taught, that the genres of Physics can be taught by Physics faculty, and that a focus on the writing process can improve student writing. Our curricular goal was to demonstrate to faculty who are unfamiliar with writing studies that writing is a means to learn in Physics (Anderson et al., 2017). The first phase of our effort was to persuade Physics faculty that writing contributes to learning in Physics; we describe a collaboration between Physics and Writing faculty that developed assignments and made curricular interventions. This collaboration built upon scholarship in writing studies that argues genre instruction develops capacities and skills for student writing (Swales, 1990; Winsor, 1996). While genre is not a new concept in Writing Studies, for many Physics faculty the idea that they can teach – and have students learn – how to write in disciplinary genres is novel. Collaboration around curricular revisions enabled Writing and Physics faculty to teach students that learning how to write in a new genre is a skill that can be practiced (Ericsson, 2006; Kellogg &amp; Whiteford, 2009). We developed a process for students to follow when faced with types of writing common to Physics, but potentially new to them, such as the abstract (written), lab research notebook (written), article summary (oral), letter to colleague (written), cover letter and resumé (written), elevator pitch (oral), proposal (written and oral), presentation on issues of ethics and equity in STEM (oral), research presentation (oral), poster (written), poster presentation (oral), final research report (written), and Symposium presentation (oral). The collaboration thus created pedagogical exchange between faculty as well as scholarly synergy between the disciplines of Physics and Writing Studies. Physics faculty have observed that the curricular collaboration has had measurable results for students. Physics student participation in the campus research day has increased dramatically. We attribute this rise partly to the increased, explicit attention in classroom settings to how to engage with Physics genres of writing, especially abstracts and research posters. While the collaboration successfully brought together a small but solid group of Writing and Physics faculty, it also raised questions about how to persuade a broader range of Physics faculty, and other science faculty, that teaching disciplinary genres can improve student writing, and that writing is a means of learning. Given that faculty in STEM disciplines find empirical research persuasive, our next step was to undertake a collaborative research project to measure the impact of the teaching of writing in Physics. The new curricular focus on genre asked students to conceptualize themselves as scientific writers in relation to specific Physics or STEM audiences. The collaborative research therefore investigates if teaching Physics genres improves writing and enables students to conceptualize themselves as emerging scientists engaged in professional communication (Poe et al., 2010; Winsor, 1996). Our longitudinal analysis of student writing in Physics evaluates writing from three sequenced courses, the first before faculty-developed genre assignments, and then after genre assignments. We developed a rubric that evaluates general outcomes – audience, genre, structure, style – and a rubric that evaluates specialized learning outcomes – acknowledgement of past scholarship, working with models, incorporating scholarship, articulation of research questions, working with graphs, and articulation of methods. Preliminary research analysis shows that explicitly teaching Physics genres increases student’s abilities to write successfully in Physics, enabling students to understand how knowledge is communicated persuasively to audiences. Our goal with this research is to show STEM faculty through research by Physicists and Writing Studies scholars that teaching writing socializes students into the discipline of Physics, leading them to identify as professional scientists (Allie et al, 2010; Gere et al., 2019). This increase is exemplified by the large number of students volunteering to present a poster during the University wide research day, giving them experience presenting to an educated audience outside of Physics. Thus, a combination of strategies – curricular collaboration and intervention, collaborative research from within the discipline of Physics, and successful external funding – are what demonstrate to scientists that teaching genre and teaching writing are central to science education. Based on this experience, our contribution is that shared pedagogical and research collaborations, and funding, are what make the knowledge of Writing Studies persuasive to scientists. We have seen success with these efforts. At George Washington, other STEM faculty have observed successes in the Physics curriculum, and have joined efforts to bring writing more explicitly into their curriculum. This year, we began a Writing in STEM symposium that has grown to include faculty in Chemistry, Systems Engineering, Mathematics, Geography, Mechanical Engineering, and other fields. We have also seen an uptick in STEM courses in the WID curriculum. The Physics and Writing research collaboration has led to a National Science Foundation (NSF) submission on genre, and an NSF award for a study of writing and engineering judgement, being conducted by Writing faculty and Systems Engineering faculty. References Allie, S., Armien, M.N., Burgoyne, N, Case, J.M., Collier-Reed, B.I, Craig, T.S., Deacon, A, Fraser, D.M.,Geyer, Z, Jacobs, C., Jawitz, J., Kloot, B., Kotta, L., Langdon, G., le Roux, K., Marshall, D, Mogashana,D., Shaw,C., Sheridan, G., &amp; Wolmarans, N. (2009). Learning as acquiring a discursive identity through participation in a community: improving student learning in engineering education. European Journal of Engineering Education, 34(4), 359-367. https://doi.org/10.1080/03043790902989457 Anderson, P., Anson, C. M., Fish, T., Gonyea, R. M., Marshall, M., Menefee-Libey, W Charles Paine, C., Palucki Blake, L. &amp; Weaver, S. (2017). How writing contributes to learning: new findings from a national study and their local application. Peer Review, 19(1), 4. Ericsson, K. A. (2009). The Influence of experience and deliberate practice on the development of superior expert performance. In K. A. Ericsson, R. R. Hoffman, A. Kozbelt &amp; A. M Williams (Eds.), The Cambridge handbook of expertise and expert performance (pp 685–705). Cambridge University Press. Gere, A. R., Limlamai, N., Wilson, E., Saylor, K., &amp; Pugh, R. (2019). Writing and conceptual learning in science: an analysis of assignments. Written communication, 36(1), 99–135. https://doi.org/10.1177/0741088318804820 Kellogg, R., &amp; Whiteford, A. (2009). Training advanced writing skills: the case for deliberate practice. Educational psychologist, 44(4), 250–266. https://doi.org/10.1080/00461520903213600 Poe, M., Lerner, N., &amp; Craig, J. (2010). Learning to communicate in science and engineering: Case studies from MIT. MIT Press. Swales, J. (1990). Discourse analysis in professional contexts. Annual review of applied linguistics, 11, 103–114. Winsor, D. A.(1996) Writing like an engineer: A rhetorical education. Mahwah, NJ: Lawrence Erlbaum Associates

Multi-scale gyrokinetic simulations: Comparison with experiment and implications for predicting turbulence and transport

To better understand the role of cross-scale coupling in experimental conditions, a series of multi-scale gyrokinetic simulations were performed on Alcator C-Mod, L-mode plasmas. These simulations, performed using all experimental inputs and realistic ion to electron mass ratio ((mi/me)1∕2 = 60.0), simultaneously capture turbulence at the ion (kθρs∼(1.0)) and electron-scales (kθρe∼(1.0)). Direct comparison with experimental heat fluxes and electron profile stiffness indicates that Electron Temperature Gradient (ETG) streamers and strong cross-scale turbulence coupling likely exist in both of the experimental conditions studied. The coupling between ion and electron-scales exists in the form of energy cascades, modification of zonal flow dynamics, and the effective shearing of ETG turbulence by long wavelength, Ion Temperature Gradient (ITG) turbulence. The tightly coupled nature of ITG and ETG turbulence in these realistic plasma conditions is shown to have significant implications for the interpretation of experimental transport and fluctuations. Initial attempts are made to develop a “rule of thumb” based on linear physics, to help predict when cross-scale coupling plays an important role and to inform future modeling of experimental discharges. The details of the simulations, comparisons with experimental measurements, and implications for both modeling and experimental interpretation are discussed.United States. Department of Energy (DE-AC02-05CH11231)United States. Department of Energy (DE-FC02-99ER54512-CMOD)United States. Department of Energy (DE-SC0006957)United States. Department of Energy (DE-FG02-06ER54871