A COMPARISON BETWEEN THE VALUES OBTAINED FROM ACTIVE DRAG ANALYSIS COMPARED TO FORCES PRODUCED IN TETHERED SWIMMING

The purpose of this study was to identify in a maximum swim effort by elite freestyle swimmers, if the mean force produced in tethered swimming over a set number of whole strokes could reliably be utilised as an alternative measure for mean propulsive force over the same number of whole strokes. Tethered force can be measured relatively easily. Although mean propulsive force at a maximum swim velocity may be derived, the process of doing so is not direct, is time consuming and requires an extensive setup. Stepwise regression analysis indicated that mean tethered force was not an acceptable alternative for mean propulsive force. Therefore the use of mean propulsive power to monitor training would require the measurement of mean propulsive force rather than simply measuring the mean tethered force in a maximum swim effort

THE USE OF PASSIVE DRAG TO INTERPRET VARIATION IN ACTIVE DRAG MEASUREMENTS

This study investigated if a measure of mean passive drag could explain the huge differences in propulsive force required by different swimmers to swim at a similar high velocity. Nineteen elite male and female national freestyle swimmers were subjects. The subject’s mean active and passive drag was measured at each swimmer’s top swimming pace. Stepwise regression analysis was used in the analysis. Passive drag was accepted into the equation to calculate mean propulsive force, prior to velocity being rejected. The correlation coefficient for the relationship between mean propelling force and mean passive drag was 0.77. This was statistically significant at the

MEASURING PROPULSIVE FORCE WITHIN THE DIFFERENT PHASES OF BACKSTROKE SWIMMING

The purpose of this study was to identify the propulsive force profile associated within the different phases of backstroke to provide individual feedback to elite swimmers and coaches. Elite backstrokers (n=4) performed three maximal velocity time trials to determine the swimmers maximum velocity. This was followed by three passive drag trials and three active drag trials using a flux vector drive dynamometer mounted on a force platform to tow them at set velocities (derived from the swimmer’s maximum swim pace) while measuring the force to do so. The computed active drag and the propulsive propelling force profile were represented as a dynamic parameter, allowing identification of intra cyclic force fluctuations with respect to time. The force profiles were synchronised to video footage which provided unique quantitative and individual stroke kinematic feedback to the elite swimmers and coaches

Romeríes del 1320

"Aquestes romeries faeren En P. Riber he En R. Torner en lany de nostre Senyor. M. CCCXX. que anaren a la perdonança de monsenyer sen Ffrancesch de Sis". Transcripció d'aquest manuscrit que es conserva en l'Arxiu de la Comunitat de Santa Maria de Ma

Education and older adults at the University of the Third Age

This article reports a critical analysis of older adult education in Malta. In educational gerontology, a critical perspective demands the exposure of how relations of power and inequality, in their myriad forms, combinations, and complexities, are manifest in late-life learning initiatives. Fieldwork conducted at the University of the Third Age (UTA) in Malta uncovered the political nature of elder-learning, especially with respect to three intersecting lines of inequality - namely, positive aging, elitism, and gender. A cautionary note is, therefore, warranted at the dominant positive interpretations of UTAs since late-life learning, as any other education activity, is not politically neutral.peer-reviewe

London 2012 Paralympic swimming: Passive drag and the classification system

Background: The key difference between the Olympic and Paralympic Games is the use of classification systems within Paralympic sports to provide a fair competition for athletes with a range of physical disabilities. In 2009, the International Paralympic Committee mandated the development of new, evidence-based classification systems. This study aims to assess objectively the swimming classification system by determining the relationship between passive drag and level of swimming-specific impairment, as defined by the current swimming class. Methods: Data were collected on participants at the London 2012 Paralympic Games. The passive drag force of 113 swimmers (classes 3-14) was measured using an electro-mechanical towing device and load cell. Swimmers were towed on the surface of a swimming pool at 1.5 m/s while holding their most streamlined position. Results: Passive drag ranged from 24.9 to 82.8 N; the normalised drag (drag/mass) ranged from 0.45 to 1.86 N/kg. Significant negative associations were found between drag and the swimming class (τ=-0.41, p<0.01) and normalised drag and the swimming class (τ=-0.60, p<0.01). The mean difference in drag between adjacent classes was inconsistent, ranging from 0 N (6 vs 7) to 11.9 N (5 vs 6). Reciprocal Ponderal Index (a measure of slenderness) correlated moderately with normalised drag (rP=-0.40, p<0.01). Conclusions: Although swimmers with the lowest swimming class experienced the highest passive drag and vice versa, the inconsistent difference in mean passive drag between adjacent classes indicates that the current classification system does not always differentiate clearly between swimming groups

MicroRNAs, miR-154, miR-299-5p, miR-376a, miR-376c, miR-377, miR-381, miR-487b, miR-485-3p, miR-495 and miR-654-3p, mapped to the 14q32.31 locus, regulate proliferation, apoptosis, migration and invasion in metastatic prostate cancer cells

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Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair

The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway