4,684 research outputs found

    Effect of soccer footwear on landing mechanics

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    Lower-extremity injury is common in soccer. A number of studies have begun to assess why specific lower-extremity injuries occur. However, currently few studies have examined how footwear affects lower-extremity mechanics. In order to address this question, 14 male (age: 22.1±3.9 years, height: 1.77±0.06m, and mass: 73.3±11.5kg) and 14 female (age: 22.8±3.1 years, height: 1.68±0.07m and mass: 64.4±9.2kg) competitive soccer players underwent a motion analysis assessment while performing a jump heading task. Each subject performed the task in three different footwear conditions (running shoe, bladed cleat, and turf shoe). Two-way analyses of variance were used to examine statistical differences in landing mechanics between the footwear conditions while controlling for gender differences. These comparisons were made during two different parts (prior to and following) of a soccer-specific jump heading task. A statistically significant interaction for the peak dorsiflexion angle (P=0.02) and peak knee flexion angle (P=0.05) was observed. Male soccer players exhibited a degree increase in dorsiflexion in the bladed cleat while female soccer players exhibited a three-degree reduction in peak knee flexion in the bladed cleat condition. Other main effects for gender and footwear were also observed. The results suggest that landing mechanics differ based upon gender, footwear, and the type of landing. Therefore, training interventions aimed at reducing lower-extremity injury should consider utilizing sport-specific footwear when assessing movement patterns. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

    Aerobrake assembly with minimum Space Station accommodation

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    The minimum Space Station Freedom accommodations required for initial assembly, repair, and refurbishment of the Lunar aerobrake were investigated. Baseline Space Station Freedom support services were assumed, as well as reasonable earth-to-orbit possibilities. A set of three aerobrake configurations representative of the major themes in aerobraking were developed. Structural assembly concepts, along with on-orbit assembly and refurbishment scenarios were created. The scenarios were exercised to identify required Space Station Freedom accommodations. Finally, important areas for follow-on study were also identified

    A 4-Planet System Orbiting the K0V Star HD 141399

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    We present precision radial velocity (RV) data sets from Keck-HIRES and from Lick Observatory's new Automated Planet Finder Telescope and Levy Spectrometer on Mt. Hamilton that reveal a multiple-planet system orbiting the nearby, slightly evolved, K-type star HD 141399. Our 91 observations over 10.5 years suggest the presence of four planets with orbital periods of 94.35, 202.08, 1070.35, and 3717.35 days and minimum masses of 0.46, 1.36, 1.22, and 0.69 Jupiter masses respectively. The orbital eccentricities of the three inner planets are small, and the phase curves are well sampled. The inner two planets lie just outside the 2:1 resonance, suggesting that the system may have experienced dissipative evolution during the protoplanetary disk phase. The fourth companion is a Jupiter-like planet with a Jupiter-like orbital period. Its orbital eccentricity is consistent with zero, but more data will be required for an accurate eccentricity determination.Comment: 11 pages, 13 figures, To appear in the Astrophysical Journa

    Adam Smith and the theory of punishment

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    A distinctive theory of punishment plays a central role in Smith's moral and legal theory. According to this theory, we regard the punishment of a crime as deserved only to the extent that an impartial spectator would go along with the actual or supposed resentment of the victim. The first part of this paper argues that Smith's theory deserves serious consideration and relates it to other theories such as utilitarianism and more orthodox forms of retributivism. The second part considers the objection that, because Smith's theory implies that punishment is justified only when there is some person or persons who is the victim of the crime, it cannot explain the many cases where punishment is imposed purely for the public good. It is argued that Smith's theory could be extended to cover such cases. The third part defends Smith's theory against the objection that, because it relies on our natural feelings, it cannot provide an adequate moral justification of punishment

    Local- and Regional-Scale Forcing of Glacier Mass Balance Changes in the Swiss Alps

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    Glacier mass variations are climate indicators. Therefore, it is essential to examine both winter and summer mass balance variability over a long period of time to address climate-related ice mass fluctuations. In this study, we analyze glacier mass balance components and hypsometric characteristics with respect to their interactions with local meteorological variables and remote large-scale atmospheric and oceanic patterns. The results show that all selected glaciers have lost their equilibrium condition in recent decades, with persistent negative annual mass balance trends and decreasing accumulation area ratios (AARs), accompanied by increasing air temperatures of +0.45 C decade 1. The controlling factor of annual mass balance is mainly attributed to summer mass losses, which are correlated with (warming) June to September air temperatures. In addition, the interannual variability of summer and winter mass balances is primarily associated to the Atlantic Multidecadal Oscillation (AMO), Greenland Blocking Index (GBI), and East Atlantic (EA) teleconnections. Although climate parameters are playing a significant role in determining the glacier mass balance in the region, the observed correlations and mass balance trends are in agreement with the hypsometric distribution and morphology of the glaciers. The analysis of decadal frontal retreat using Landsat images from 1984 to 2014 also supports the findings of this research, highlighting the impact of lake formation at terminus areas on rapid glacier retreat and mass loss in the Swiss Alps

    Palaeoenvironment and taphonomy of the <i>Hypsilophodon </i>Bed, Lower Cretaceous Wessex Formation, Isle of Wight

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    The ‘Hypsilophodon Bed’ occurs at the top of the Wessex Formation (Early Cretaceous, Barremian) on the Isle of Wight, England. Numerous remains of the small ornithopod dinosaur Hypsilophodon foxii have been recovered from the bed since the mid-19th century. Previous theories for these fossil occurrences have focused on catastrophic mass death events including miring and flood-related mortality. However, only limited sedimentological and taphonomic analyses of the horizon and its fossil assemblage have been undertaken, hindering efforts to evaluate different theories for how the assemblage formed.Here, we undertake a sedimentological study of the bed to constrain its depositional environment, examine matrix from Hypsilophodon fossils to identify where they were collected from within the bed, and undertake taphonomic investigation of Hypsilophodon specimens. Results reveal a floodplain which became a marsh and then mudflats at the edge of a lagoon. Hypsilophodon fossils are spatially and stratigraphically distributed throughout the bed. Specimens are largely incomplete and unabraded suggesting most perished on or near to the floodplain and may have lain exposed for some time prior to burial. Overall, evidence suggests the fossil assemblage of the Hypsilophodon Bed formed as an accumulation of remains over time
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