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Eric R. Muoz Jaclyn B. Caccese Brittany E. Wilson Kyle T. Shuler Fernando V. Santos Carolina T. Cabn John J. Jeka Dianne Langford Matthew B. Hudson 《运动与健康科学(英文)》2021,10(2):122
BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease. 相似文献
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The analysis of sport performance in competitive contexts has become synonymous with the use of a range of software applications and hardware e.g. heart rate monitors and gps systems. With the prevalence of technology in mind, a small but growing corpus of literature has begun to consider this phenomenon and its influence upon the coaching process. This study adds to this literature by detailing the autoethnographic experiences of a case study coach; Derek. A contextualised and richly described narrative account of Derek’s experience of using coaching applications is provided. Analysis of Derek’s narrative suggests that technology can be a useful means by which individuals make sense of their experience. Specifically, (1) technology can be a ‘ready-to-hand’ instrument that enhances the coaching process. Unfortunately, (2) technology may become the only and ‘calculative’ means by which individuals come to understand their performance. In such instances, it is important to note that (3) the videos we use to understand our performance are transformed and incomplete representations of lived athletic experiences. Thus, Derek’s story illustrates how technology can be both an enabler and barrier to athletes who wish to holistically understand their own lived experiences and engage in coach-athlete relationships. The accompanying analysis draws upon concepts from Heideggerian philosophy to add insight into the use of technology within the coaching process. In so doing, the study prompts coaches to critically view their coach-athlete relationships as situated in a wider world which contains, and can be mediated by, technology. In addition, Derek’s story (re)directs researchers and coaching practitioners interested in technology to a useful literature (philosophy of technology) which may further inform their understanding of coach-athlete relationships. 相似文献
4.
Ben L. Langdown Jack E.T. Wells Sean Graham Matt W. Bridge 《Journal of sports sciences》2019,37(6):656-664
Previous research has highlighted the positive effect that different warm-up protocols have on golf performance (e.g. Sorbie et al., 2016; Tilley & Macfarlane, 2012) with the design of warm-ups and programmes targeting and improving golf performance through the activation and development of specific muscle groups. This study aimed to examine the acute effects of two warm-up protocols on golf drive performance in comparison to a control condition. Using a randomised counterbalanced design over three testing sessions, twenty-three highly skilled golfers completed the control, dynamic and resistance-band warm-up conditions. Following each condition, a GC2 launch monitor was used to record ball velocity and other launch parameters of ten shots hit with the participants’ own driver. A repeated-measures ANOVA found significant increases in ball velocity (ηp2 = .217) between the control and both the dynamic and resistance-band warm-up conditions but no difference between these latter two, and a reduction in launch angle between control and dynamic conditions. The use of either a dynamic stretching or resistance-band warm-up can have acute benefits on ball velocity but golfers should liaise with a PGA Professional golf coach to effectively integrate this into their golf driving performance. 相似文献
5.
Samuel T. Orange Phil Marshall Leigh A. Madden Rebecca V. Vince 《Journal of sports sciences》2019,37(11):1227-1234
This study examined the relationship between sit-to-stand (STS) power and physical function in adults with severe obesity. Thirty-eight adults (age: 44 ± 12 years; body mass index [BMI]: 45.2 ± 7.8 kg/m2) completed evaluations of STS power, strength and functional performance. STS power was measured with a wearable inertial sensor, strength was assessed with the isometric mid-thigh pull, and function was measured with the timed up-and-go (TUG), six-minute walk test (6MWT) and 30-s chair STS. Power and strength (normalised to body mass) entered regression models in addition to age, gender, BMI and physical activity (daily step count). Power displayed large univariate associations with TUG (r = 0.50) and 30-s chair STS (r = 0.67), and a moderate association with 6MWT (r = 0.49). Forward stepwise regression revealed that power independently contributed to TUG (β = ?0.40, p = 0.010), 30-s chair STS (β = 0.67, p < 0.001) and 6MWT performance (β = 0.27, p = 0.007). Power also appeared to be a superior determinant of function compared with strength. Power generated via the STS transfer largely underpins the ability to perform functional tasks in adults with severe obesity, although intervention studies are required to investigate a potentially causal relationship. 相似文献
6.
Colleges and universities in the United States often promote diversity through a neoliberal lens by framing diversity as a celebration of individual differences or a commodity that students can gain by attending their institution. In communication courses, diversity has been conceptualized through both neoliberal and critical lenses, but limited research has investigated how communication students define and explain diversity. The focus of this study was to understand how communication students define diversity. We performed thematic analyses on open-ended survey responses to investigate how communication students define diversity. Four themes emerged from our analyses: (a) diversity is a mechanism for unifying communities, (b) diversity is an affirmation of individual differences, (c) diversity is a harbinger of acceptance and equality, and (d) diversity is a disruptive force that re-centers the voices of traditionally marginalized people. Our findings indicate most communication students define diversity through a neoliberal lens. However, 3% of our participants conceptualized diversity through a critical lens by explaining that diversity should create space for those who are marginalized to have their voices heard. We conclude by providing recommendations for communication instructors to incorporate more critical conversations about diversity into their classrooms and foster diverging discourses about diversity across communication curricula. 相似文献
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Dan J. Miller Garry Kidd Peter T. F. Raggatt Kerry Anne McBain Wendy Li 《Communication Research Reports》2020,37(3):110-121
ABSTRACT The idea that pornography promotes sexism is a commonly purported one. This study employed an online sample of heterosexual men (N = 323) to investigate the relationship between pornography use (in terms of both overall level of pornography use and use of violent and/or humiliating pornography) and old-fashioned and modern sexism. The moderating effects of agreeableness and perceived realism of pornography were also assessed. Level of general pornography use and use of violent and/or humiliating pornography was not predictive of either sexism measure. Agreeableness was negatively predictive of both sexism measures, whereas perceived realism was positively predictive of sexism. Agreeableness and perceived realism did not moderate the relationship between level of pornography use and any of the outcome measures. 相似文献
9.
Pantelis T. Nikolaidis 《Journal of sports sciences》2019,37(12):1387-1392
The present retrospective study intended to determine age, performance, the role of nationality and participation trends across calendar years in runners competing in “Comrades Marathon”, the ultra-marathon with the longest tradition and the highest number of finishers worldwide. We analysed 235,467 finishers (40,211 women and 195,256 men) competing between 1994 and 2017. In women and men, Russians were the fastest (12.55 ± 2.03 km/h and 12.24 ± 2.93 km/h, respectively) and Indians the slowest (7.87 ± 0.64 km/h and 7.91 ± 0.60 km/h) (p < 0.001, η2 = 0.053 and η2 = 0.010, small effect size, ES). Also, Russians were the youngest (33.9 ± 4.6 and 36.3 ± 5.9 years, respectively) and Japanese the oldest (49.3 ± 9.6 and 51.4 ± 12.3 years, respectively) (p < 0.001, η2 = 0.011, small ES). Performance improved (r = 0.90 in women and r = 0.92 in men), age of finishers (r = 0.91 in women and r = 0.97 in men), participation (r = 0.92 in women and r = 0.87 in men) and sex difference in age increased (r = 0.71), whereas men-to-women ratio (r = ?0.91) and sex difference in performance (r = ?0.68) decreased across calendar years (p < 0.001). In summary, runners from Russia were the fastest and the youngest in both sexes. The knowledge of the relationship of nationality with performance, age and participation trends of finishers, and changes across calendar years are of practical importance for ultra-runners and coaches working with them. 相似文献
10.
Piret Luik Reelika Suviste Marina Lepp Tauno Palts Eno Tõnisson Merilin Säde Kaspar Papli 《British journal of educational technology : journal of the Council for Educational Technology》2019,50(1):153-165
Learners who enrol in massive open online courses (MOOCs) have different backgrounds and tend to have different motivations than learners in traditional courses. Based on value-expectancy theory, an instrument was developed to measure motivation for enrolling in a programming MOOC. A study with 1229 adult participants in Estonian-language programming course “About Programming” was conducted to validate the instrument. Results of confirmatory factor analysis validated the 7-factor scale named factors influencing enrolment in MOOC (FIEM). FIEM comprises three factors of expectancies, three factors of values and one factor of social influence. The highest and lowest rated motivational factors influencing enrolment in programming MOOC are discussed in the paper. Interest in and expectations for the course, personal suitability of distance learning and suitability for family and work are the highest-rated motivational factors for those who enrol in MOOC. Usefulness related to own children, social influence and usefulness to related to certification were the lowest rated. The results of this study can be useful for designers of programming MOOCs and the developed scale might be used in future studies. 相似文献