FACTORS RELATED TO THE DEVELOPMENT OF BALL SPEED AND TO THE INCIDENCE OF ONE-LEGGED LANDINGS IN THE FRONT-ROW VOLLEYBALL ATTACK

A three-dimensional video analysis was used to identify factors related to the development of ball speed and to the incidence of one-legged landings in high-outside, front-row volleyball attacks. At ball contact, hand speed was 11.9±O.9 m·s-1 (mean±SD). Post-impact ball speed was 19.4±2.3 m·s-1. Shoulder and elbow rotations accounted for about 75% of hand speed at the instant of ball contact while the speed of the CM itself accounted for about 16% of hand speed. Trunk rotation and wrist rotation contributed 11 % and 2% to hand speed, respectively. Attackers possessed forward somersaulting, counterclockwise twisting, and counterclockwise "cartwheeling" angular momentum that resulted in faster hand speeds at contact but also a tendency for one-legged landings. Unfortunately. factors contributing to one-legged landings could not be clearly identified

DETERMINISTIC FACTORS OF OVERALL BALL CONTACT HEIGHT DURING HIGH-OUTSIDE FRONT-ROW VOLLEYBALL ATTACKS

The purpose of this study was to quantify the deterministic factors of overall ball contact height among elite level volleyball attackers. Thirty-two trials collected from nine members of the 1999 USA National A2 Team were subjected to 3D analysis. Results demonstrated that takeoff height (CM height at takeoff) and reach height (vertical distance between the hand and CM at contact) accounted for 86.7% of the overall ball contact height. Flight height (in-flight CM elevation) accounted for only 14% of overall height. Reach height was the only meaningful sUb-height that was significantly correlated with overall ball contact height (r=O.70) and appeared to be most sensitive to technique-related differences in performance. Horizontal approach speeds used by the athletes in this study were relatively slow (3.4±O.3 m·s-1) but were positively correlated with flight height (r=O.60)

DOES AN EXTRA MASS IMPROVE THE ARM SWING SPEED?

This study investigated the effect of adding extra mass on individual segments during the performance of an arm swing task in the horizontal plane. The amount of extra mass was 0, 25, 50, 75, and 100% of the mass of the segment on which the extra mass was placed (upper arm or forearm). The variables studied were arm swing speed (hand speed), positive muscle impulse, and system moment of inertia (MOI). The purpose was to see if adding extra mass sped up or slowed down the arm swing and why. Twenty subjects were instructed to produce their maximum hand swing speed over the target point during the horizontal non-dominant arm swing. It was found that the forearm extra mass elicited a significant decrease in the arm swing speed, while the upper arm added mass did not cause decreases in arm speed. Rather, moderate amounts of extra mass at the upper arm (25 and 50% extra mass) induced slight, although not significant, increases in arm swing speed (0.66% and 1.41% increase, respectively). These increases in speed were accompanied by small increases in both the positive muscle impulse and the system MOI with the upper arm extra mass. Significant increases in the system MOI accounted for the significant swing speed drop caused by the forearm extra mass. It was concluded that extra mass is not always detrimental to the arm swing speed. Extra mass added close to the axis of rotation either makes no difference or may actually help swing speed

IODP Advances in the Understanding of Subseafloor Life

The most recent decadal phase of scientific ocean drilling through the International Ocean Discovery Program (IODP) has resulted in paradigm-shifting understanding of life below the seafloor. Enabled by new drilling and coring approaches, cutting-edge methodologies, and novel observatory science, IODP expeditions have significantly advanced understanding of the amount and diversity of subseafloor life, the metabolic strategies that this life uses to survive under extreme energy limitation, and consequences of this life for the Earth system. Here, we summarize highlights from recent IODP expeditions focused on life beneath the seafloor and emphasize remaining major science challenges in investigating the form and function of life in this environment

A note on Makeev's conjectures

A counterexample is given for the Knaster-like conjecture of Makeev for functions on $S^2$. Some particular cases of another conjecture of Makeev, on inscribing a quadrangle into a smooth simple closed curve, are solved positively

Scaling property of the critical hopping parameters for the Bose-Hubbard model

Recently precise results for the boundary between the Mott insulator phase and the superfluid phase of the homogeneous Bose-Hubbard model have become available for arbitrary integer filling factor g and any lattice dimension d > 1. We use these data for demonstrating that the critical hopping parameters obey a scaling relationship which allows one to map results for different g onto each other. Unexpectedly, the mean-field result captures the dependence of the exact critical parameters on the filling factor almost fully. We also present an approximation formula which describes the critical parameters for d > 1 and any g with high accuracy.Comment: 5 pages, 5 figures. to appear in EPJ

Foundation of a component-based flexible registry for language resources and technology

Within the CLARIN e-science infrastructure project it is foreseen to develop a component-based registry for metadata for Language Resources and Language Technology. With this registry it is hoped to overcome the problems of the current available systems with respect to inflexible fixed schema, unsuitable terminology and interoperability problems. The registry will address interoperability needs by refering to a shared vocabulary registered in data category registries as they are suggested by ISO

Gene therapy strategies for idiopathic pulmonary fibrosis:recent advances, current challenges, and future directions

Idiopathic pulmonary fibrosis (IPF) is a chronic disease in which the lungs become irreversibly scarred, leading to declining lung function. As currently available drugs do not cure IPF, there remains a great medical need for more effective treatments. Perhaps this need could be addressed by gene therapies, which offer powerful and versatile ways to attenuate a wide range of processes involved in fibrosis. Despite the potential benefits of gene therapy, no one has reviewed the current state of knowledge regarding its application for treating IPF. We therefore analyzed publications that reported the use of gene therapies to treat pulmonary fibrosis in animals, as clinical studies have not been published yet. In this review, we first provide an introduction on the pathophysiology of IPF and the most well-established gene therapy approaches. We then present a comprehensive evaluation of published animal studies, after which we provide recommendations for future research to address challenges with respect to the selection and use of animal models as well as the development of delivery vectors and dosage forms. Addressing these considerations will bring gene therapies one step closer to clinical testing and thus closer to patients