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Simulations of Prebiotic Chemistry under Post-Impact Conditions on Titan

Author(s):Carol Turse -- Johannes Leitner -- Maria Firneis -- Dirk Schulze-Makuch
Journal: Life
Publisher:
Abstract
| Pages: 538-549
The problem of how life began can be considered as a matter of basic chemistry. How did the molecules of life arise from non-biological chemistry? Stanley Miller’s famous experiment in 1953, in which he produced amino acids under simulated early Earth conditions, was a huge leap forward in our understanding of this problem. Our research first simulated early Earth conditions based on Miller’s experiment and we then repeated the experiment using Titan post-impact conditions. We simulated conditions that could have existed on Titan after an asteroid strike. Specifically, we simulated conditions after a potential strike in the subpolar regions of Titan that exhibit vast methane-ethane lakes. If the asteroid or comet was of sufficient size, it would also puncture the icy crust and bring up some of the subsurface liquid ammonia-water mixture. Since, O’Brian, Lorenz and Lunine showed that a liquid water-ammonia body could exist between about 102–104 years on Titan after an asteroid impact we modified our experimental conditions to include an ammonia-water mixture in the reaction medium. Here we report on the resulting amino acids found using the Titan post-impact conditions in a classical Miller experimental reaction set-up and how they differ from the simulated early Earth conditions.

Assessing Cycling Participation in Australia

Author(s):Chris Rissel -- Cameron Munro -- Adrian Bauman
Journal: Sports
Publisher:
Abstract
| Pages: 1-9
Planning and evaluating cycling programs at a national or state level requires accurate measures of cycling participation. However, recent reports of cycling participation have produced very different estimates. This paper examines the reported rates of cycling in five recent population surveys of cycling. Three surveys (one national and two from Sydney) asking respondents when they last rode a bicycle generated cycling participation (cycled in the past year) estimates of 29.7%, 34.1% and 28.9%. Two other national surveys which asked participants to recall (unprompted) any physical activity done for exercise, recreation or sport in the previous 12 months, estimated cycling in the past year as 11.1% and 6.5%. While unprompted recall of cycling as a type of physical activity generates lower estimates of cycling participation than specific recall questions, both assessment approaches produced similar patterns of cycling by age and sex with both approaches indicating fewer women and older adults cycling. The different question styles most likely explain the substantial discrepancies between the estimates of cycling participation. Some differences are to be expected due to sampling variability, question differences, and regional variation in cycling.

Exercise Exploring Mutuality and Discordance(s) Between Sport and Public Health

Author(s):Eling D. de Bruin
Journal: Sports
Publisher:
Abstract
| Pages: 10-12
Sports is a peer-reviewed scientific journal that revolves around the interdisciplinary area of exercise sciences applied in sport and public health. The intention of Sports is to link several scientific disciplines in an integrated fashion in order to address critical issues related to exercise science, sports and public health. As the first Editor-in-Chief of Sports, I would like to share a few comments about this interdisciplinary field of research by discussing the mutuality and discordances between exercise as it is applied in sports and public health. [...]

Paralympics and Its Athletes Through the Lens of the New York Times

Author(s):Jeremy Tynedal -- Gregor Wolbring
Journal: Sports
Publisher:
Abstract
| Pages: 13-36
The purpose of this article is to analyze the coverage of the Paralympics in the New York Times (NYT) from the first appearance of the term Paralympics in 1955 up to 2012. We analyzed a) the textual imagery (not imagery intrinsic to pictures) of the Paralympics and its athletes, b) the representation of views and hopes of Paralympians and c) the visibility of the Paralympics and Paralympians within the NYT. We found that NYT coverage of the Paralympics and Paralympians is minimal and often portrays Paralympic athletes in stereotypical ways, such as being supercrips or suffering entities. In regards to the portrayal of therapeutic assistive devices of Paralympic athletes in the NYT, four themes are evident: a) the advancement of technology, b) the hierarchy between different therapeutic assistive devices, c) the relationship between the device and the athlete and d) the affordability of the device. We submit that the portrayal of the Paralympics, as evident in the NYT, for the most part does not help to further the discussion around a) the future of the Paralympics and its role within society, b) the relationship between the Paralympics and the Olympics and c) barriers of sport participation faced by athletes with disabilities on all levels, from recreational to competitive sport.

Should Rehabilitation Specialists Use External Focus Instructions When Motor Learning Is Fostered? A Systematic Review

Author(s):Tanja H. Kakebeeke -- Ruud H. Knols -- Eling D. de Bruin
Journal: Sports
Publisher:
Abstract
| Pages: 37-54
According to the Constrained Action Hypothesis, motor learning is believed to be more efficient when an external focus (EF) of motor control is given to the performer instead of an internal focus (IF) of motor control. This systematic review investigated whether findings of studies focusing on the Constrained Action Hypothesis may be transferred to rehabilitation settings by assessing the methodological quality and risk of bias (ROB) of available randomized controlled trials (RCTs). Of the 18 selected reports representing 20 RCTs, the methodological quality was rather low, and the majority of the reports appeared to have a high ROB. The 18 reports included 68 patients tested in a rehabilitation setting and 725 healthy participants. The time scale of the motor learning processes presented in the selected articles was heterogenic. The results of this systematic review indicate that the assumption that an external focus of control is to be preferred during motor learning processes is not sufficiently substantiated. The level of available evidence is not large enough to warrant transfer to patient populations (including children and the elderly) and raises doubts about research with healthy individuals. This implies that based on the methodology used so far, there seems to be insufficient evidence for the superiority of an external focus of control, neither in healthy individuals nor in clinical populations. The relationship between EF instructions and motor learning research and its effect in both patient rehabilitation settings and healthy populations requires further exploration. Future adequately powered studies with low ROB and with rehabilitation populations that are followed over extended time periods should, therefore, be performed to substantiate or refute the assumption of the superiority of an EF in motor learning.

Acute Effects of Polyphenols from Cranberries and Grape Seeds on Endothelial Function and Performance in Elite Athletes

Author(s):Kim Labonté -- Charles Couillard -- Annie Motard-Bélanger -- Marie-Eve Paradis -- Patrick Couture -- Benoît Lamarche
Journal: Sports
Publisher:
Abstract
| Pages: 55-68
We examined how intake of polyphenols modifies brachial artery flow-mediated dilation (FMD) at rest, and cycling anaerobic performance, in elite athletes. In the first randomized cross-over study, FMD was measured over a three-hour period on two occasions in eight elite male and female athletes after acute consumption of either polyphenols from cranberries and grape seeds (600 mg) or a polyphenol-free placebo drink. Consumption of the polyphenol-rich drink led to a significant increase in FMD compared to placebo (p = 0.02), with a peak at 60 min. In a second study, 12 elite male and female athletes completed a three-kilometer time trial (TT) on an ergocycle on two occasions in random order, either after consumption of 800 mg of polyphenols or a placebo. Acute intake of the polyphenol extract had no impact on the three-kilometer time trial completion. However, plasma lactate levels were significantly lower before and after the TT when subjects consumed the polyphenols vs. placebo (p < 0.05). Results suggest that polyphenols from cranberries and grape seeds acutely modifies FMD at rest in elite athletes but this does not translate into enhanced cycling anaerobic performance.

A Comparison between Australian Football League (AFL) Injuries in Australian Indigenous versus Non-indigenous Players

Author(s):Jessica Orchard -- John Orchard -- Hugh Seward
Journal: Sports
Publisher:
Abstract
| Pages: 69-77
It has previously been shown that being of aboriginal descent is a risk factor for hamstring injuries in Australian football. The aim of this study was to review the Australian Football League (AFL) injury database to determine whether there were any injuries where indigenous players had different relative risks to non-indigenous players. Analysis was conducted using data from the AFL injury database, which included data from 4,492 players over 21 years (1992–2012), covering 162,683 player-matches at AFL level, 91,098 matches at lower levels and 328,181 weeks (possible matches) of exposure. Compared to non-indigenous players, indigenous players had a significantly higher risk of hamstring injuries (RR 1.52, 95% CI 1.32–1.73) and calf strains (RR 1.30, 95% CI 1.00–1.69). Conversely, indigenous players had a significantly lower risk of lumbar/thoracic spine injuries (RR 0.61, 95% CI 0.41–0.91), groin strains/osteitis pubis (RR 0.75, 95% CI 0.58–0.96) and Achilles tendon injuries (RR 0.32, 95% CI 0.12–0.86). The results for the above injuries were also significant in terms of games missed. There was no difference between overall risk of injury (RR 1.03, 95% CI 0.96–1.10) or missed games (RR 1.00, 95% CI 0.97–1.04). This suggests that indigenous AFL players have the same overall number of injuries and missed games, but a slightly different injury profile.

Materials, Designs and Standards Used in Ski-Boots for Alpine Skiing

Author(s):Martino Colonna -- Marco Nicotra -- Matteo Moncalero
Journal: Sports
Publisher:
Abstract
| Pages: 78-113
This review article reports the recent advances in the study, design and production of ski-boots for alpine skiing. An overview of the different designs and the materials used in ski-boot construction is provided giving particular emphasis to the effect of these parameters on the final performances and on the prevention of injuries. The use of specific materials for ski-boots dedicated to different disciplines (race skiing, mogul skiing, ski-mountaineering etc.) has been correlated with the chemical and physical properties of the polymeric materials employed. A review of the scientific literature and the most interesting patents is also presented, correlating the results reported with the performances and industrial production of ski-boots. Suggestions for new studies and the use of advanced materials are also provided. A final section dedicated to the standards involved in ski-boot design completes this review article.

Responder Feelings in a Three-Player Three-Option Ultimatum Game: Affective Determinants of Rejection Behavior

Author(s):Hans-Rüdiger Pfister -- Gisela Böhm
Journal: Games
Publisher:
Abstract
| Pages: 1-29
This paper addresses the role of affect and emotions in shaping the behavior of responders in the ultimatum game. A huge amount of research shows that players do not behave in an economically rational way in the ultimatum game, and emotional mechanisms have been proposed as a possible explanation. In particular, feelings of fairness, anger and envy are likely candidates as affective determinants. We introduce a three-player ultimatum game with three-options, which permits the responder to either penalize the proposer or to penalize a third party by rejecting offers. This allows for partially distinguishing rejections due to a retaliation motive driven by anger towards the proposer from rejections due to inequity aversion driven by feelings of envy towards a third party. Results from two experiments suggest that responders experience feelings of dissatisfaction and unfairness if their share is small in comparison to the proposer’s share; anger, then, may trigger rejections towards the proposer. Responders also experience dissatisfaction and envy when third party shares exceed their own shares; however, in contrast to anger, envy does not trigger rejections and is dissociated from the decision to accept or reject an offer. We conclude that acting upon anger is socially acceptable, whereas envy is not acceptable as a reason for action. Furthermore, we find that responders generally feel better after rejections, suggesting that rejections serve to regulate one’s affective state.
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