The clubhead and hand planes in golf draw and fade shots.

Swing planes in golf have become a popular area of research. Cochran and Stobbs (1968) examined the motion of the clubhead and hands qualitatively. Subsequent quantitative analyses have included investigations of the planarity of the whole club (Coleman & Anderson, 2007) and clubhead (Shin, Casebolt, Lambert, Kim, & Kwon, 2008). The aim of this study was to investigate the motion of the clubhead and hands in the downswing quantitatively, and to compare these motions for the fade and draw (as suggested by Coleman and Anderson, 2007). In conclusion, both the clubhead and hand planes in the late downswing were found to differ significantly in relation to the target line between the draw and fade shots. Greater differences were found between golfers, rather than between shots, in the relationship between the clubhead and hand motion during the downswing. Nevertheless, further detailed analysis is warranted of how the motions around impact – especially the clubface orientation – differ between the two types of shot

The clubhead swing plane in golf draw and fade shots

It has become popular to characterise a golf shot in terms of a ‘swing plane’. However Coleman and Anderson (2007) showed that the motion of the whole club in the downswing could not be represented by a single plane in all players. Shin et al. (2008) found that the clubhead motion was consistently planar between the club being horizontal in the downswing and follow-through. Coleman and Anderson (2007) also suggested that the club plane might differ between draw and fade shots. The purpose of this study was to compare draw and fade shots, with a focus on the clubhead motion in the late downswing. The late downswing clubhead plane differs between a draw and a fade shot, even when differences in address angles are accounted for

EFFECTS OF NON-INSTRUCTED PRACTICE ON A NOVEL ROWING TASK

Information feedback has been shown to be an important part of the learning process, yet changes have not been assessed within sporting applications. Non-rowers (n=7) performed a 10-minute novel rowing task, and joint and rowing ergometer kinematics recorded. Following four non-instructed practice rowing sessions, their techniques were reassessed. Results showed that the ergometer handle trajectory became more elliptical throughout the stroke and that the knees were more flexed at catch (11°) and more extended at the finish (13°). Changes in the shape of the handle trajectory caused changes in the lengths of the pull and recovery phases and implied changes in the timing of joint motions. This study is a step towards understanding the motor learning of novices

THE EFFECTS OF CONCURRENT BIOFEEDBACK ON ROWING PERFORMANCE

The aim of this study was to assess the effects of concurrent biofeedback (BFb) on the ability of skilled rowers to modify the relative motions of their elbow and knee joints during ergometer rowing. Over 2 weeks, BFb (n=7) and control (n=7) participants completed two maximal rowing tasks (pre-intervention; transfer) separated by three submaximal rowing sessions supplemented with BFb for the BFb group. Pre-intervention to transfer session patterns showed increased elbow extension and knee flexion in the early phases of the pull, which was a move towards the pattern advocated by the BFb intervention. Although these alterations were not universal, BFb appears to be a useful training aid for those further from the target movement pattern

THE EFFECTS OF AUGMENTED BIOFEEDBACK ON NOVEL MOTOR-TASK LEARNING

Biofeedback has been shown to be an influential part of skill acquisition and performance, however, the use of biofeedback for novice, sports specific skill learning has not been assessed. Non-rowers (n=3) performed a 10-minute, novel-rowing task, where joint and rowing ergometer kinematics recorded. Following six non-instructed, subjective reinforcement sessions, participants completed a further six sessions whilst receiving real-time biofeedback. The results show that all subjects changed their rowing technique, moving towards the pattern prescribed by the biofeedback intervention. The elbow remained in greater extension until later in the pull, which induced changes in the temporal aspects of both knee and lumbar spine kinematics

THE EFFECT OF BUNGEE TENSION ON POWER PROFILING IN KAYAK ERGOMETRY

In water sports, where accurate biomechanical measurement in situ is difficult, ergometers are frequently used to test athletes. Many kayak ergometer designs involve a bungee to assist in returning the athlete/paddle to the correct position for the next stroke. The study’s aim was to investigate the effect of bungee tension on the ergometermeasured maximal power-velocity profile of three experienced male kayak athletes. Bungee tension influenced the power-velocity profile, reducing peak power measured by up to 328.4 W from optimal to least optimal tension. Athlete’s anecdotally preferred feel tensions may be optimal, thus these tensions should be considered in investigating power-related factors

Animal community dynamics at senescent and active vents at the 9° N East Pacific Rise after a volcanic eruption

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gollner, S., Govenar, B., Arbizu, P. M., Mullineaux, L. S., Mills, S., Le Bris, N., Weinbauer, M., Shank, T. M., & Bright, M. Animal community dynamics at senescent and active vents at the 9° N East Pacific Rise after a volcanic eruption. Frontiers in Marine Science, 6, (2020): 832, doi:10.3389/fmars.2019.00832.In 2005/2006, a major volcanic eruption buried faunal communities over a large area of the 9°N East Pacific Rise (EPR) vent field. In late 2006, we initiated colonization studies at several types of post eruption vent communities including those that either survived the eruption, re-established after the eruption, or arisen at new sites. Some of these vents were active whereas others appeared senescent. Although the spatial scale of non-paved (surviving) vent communities was small (several m2 compared to several km2 of total paved area), the remnant individuals at surviving active and senescent vent sites may be important for recolonization. A total of 46 meio- and macrofauna species were encountered at non-paved areas with 33 of those species detected were also present at new sites in 2006. The animals living at non-paved areas represent refuge populations that could act as source populations for new vent sites directly after disturbance. Remnants may be especially important for the meiofauna, where many taxa have limited or no larval dispersal. Meiofauna may reach new vent sites predominantly via migration from local refuge areas, where a reproductive and abundant meiofauna is thriving. These findings are important to consider in any potential future deep-sea mining scenario at deep-sea hydrothermal vents. Within our 4-year study period, we regularly observed vent habitats with tubeworm assemblages that became senescent and died, as vent fluid emissions locally stopped at patches within active vent sites. Senescent vents harbored a species rich mix of typical vent species as well as rare yet undescribed species. The senescent vents contributed significantly to diversity at the 9°N EPR with 55 macrofaunal species (11 singletons) and 74 meiofaunal species (19 singletons). Of these 129 species associated with senescent vents, 60 have not been reported from active vents. Tubeworms and other vent megafauna not only act as foundation species when alive but provide habitat also when dead, sustaining abundant and diverse small sized fauna.We received funding from the Austrian FWF (GrantP20190-B17; MB), the U.S. National Science Foundation (OCE-0424953; to LM, D. McGillicuddy, A. Thurnherr, J. Ledwell, and W. Lavelle; and OCE-1356738 to LM), and the European Union Seventh Framework Programme (FP7/2007-2013) under the MIDAS project, Grant Agreement No. 603418. Ifremer and CNRS (France) supported NL cruise participation and sensor developments. BG was supported by a postdoctoral fellowship from the Deep Ocean Exploration Institute at WHOI (United States). TS was supported by the U.S. National Science Foundation (OCE-0327261 to TS and OCE-0937395 to TS and BG)

Factors related to adolescent drinking in Appalachia

Objectives: To examine the relationships among parental monitoring, perceptions of peer drinking, and adolescent alcohol consumption. Methods: Tenth- and 12thgrade students (N=648) in a rural, Appalachian county were surveyed. Results: A binomial logistic regression revealed a composite of those who had perceptions that many peers drank, low parental monitoring, and no biological male guardian in the home were 8.496 times more likely to have ever been drunk. Other characteristics resulted in lower odds. Conclusions: Parental monitoring and perceptions of peer drinking were important predictors of drinking in this rural sample. Prevention efforts in school and at home should address both variables

RELIABILITY OF DIFFERENT METHODS OF DETERMINING INDIVIDUAL INTER-STROKE INTERVALS IN SPRINT KAYAKING

The purpose of this study was to explore the reliability of methods for rapidly determining inter-stroke intervals (ISI) of individual kayakers. One participant performed two 150 m trials at a rate of 80 single-strokes/min. ISI were calculated using two criterion measures, visual identification of blade immersion (VID) and peaks in longitudinal acceleration of the kayak hull (ACC). These were compared to ISI from peak footrest force (FRP), initiation of footrest force (FRT), paddle Y axis rotational velocity (PAP) and paddle X axis acceleration (PAA). Least products regression analysis (LPR) revealed that FRP showed the highest reliability, with no fixed or proportional bias compared to VID or ACC. High ISI during the initial strokes influenced the results of the LPR, as such a framework for investigating the reliability of ISI using LPR is suggested where the initial strokes are removed prior to analysis

Thermodynamic limits on oxygenic photosynthesis around M-dwarf stars: Generalized models and strategies for optimization

We explore the feasibility and potential characteristics of photosynthetic light-harvesting on exo-planets orbiting in the habitable zone of low mass stars ($< 1$ M$_{\odot}$). As stellar temperature, $T_{s}$, decreases, the irradiance maximum red-shifts out of the $400 \textrm{nm} \leq \lambda < 750$ nm range of wavelengths that can be utilized by \emph{oxygenic} photosynthesis on Earth. However, limited irradiance in this region does not preclude oxygenic photosynthesis and Earth's plants, algae and cyanobacteria all possess very efficient \emph{light-harvesting antennae} that facilitate photosynthesis in very low light. Here we construct general models of photosynthetic light-harvesting structures to determine how an oxygenic photosystem would perform in different irradiant spectral fluxes. We illustrate that the process of light-harvesting, capturing energy over a large antenna and concentrating it into a small \emph{reaction centre}, must overcome a fundamental \emph{entropic barrier}. We show that a plant-like antenna cannot be adapted to the light from stars of $T_{s}<3400$ K, as increasing antenna size offers diminishing returns on light-harvesting. This can be overcome if one introduces a slight \emph{enthalpic gradient}, to the antenna. Interestingly, this strategy appears to have been adopted by Earth's oxygenic cyanobacteria, and we conclude that \emph{bacterial} oxygenic photosynthesis is feasible around even the lowest mass M-dwarf stars.Comment: 5 Figures, submitted to Astrobiology and awaiting return of revie