Association Between Anthropometrics, Vertical Jump and Broad Jump to Pure and Transitional Acceleration in Junior College Baseball Players

Sprint acceleration is a key physical attribute in baseball players that can be characterized by two phases: pure (PURE) and transitional (TRANS) acceleration. In a linear sprint, PURE occurs from the initiation of movement to approximately 15-meters; TRANS acceleration occurs from approximately 15-meters until an athlete reaches top velocity. Since baseball fields are clearly marked at 13.7m (foul-line) and 27.4m (1st base), acceleration can be determined in a sports-specific environment and these data may be helpful in characterizing player success. Purpose The purpose of this study was to determine the relationship between anthropometrics, vertical, and broad jump ability to PURE and TRANS acceleration of junior college baseball players sprinting to first-base. Methods: Nineteen male junior college baseball players (19.6 ± 2.2y; 181.2 ± 6.9cm; 80.6 ± 11.7kg) volunteered as subjects. They performed tests of physical performance on three days, separated by one week. Initially, subject height and body mass (BM) were determined using a standard equipment. Percent fat (%Fat) was measured using skinfold calipers and a three-site equation. On a separate day, countermovement vertical jumps were performed on a force plate set to sample at 400 Hz. Vertical jump height (VJ), peak force (PF), peak power (PP), and relative power (PP rel) were determined from these data. Broad jump (BJ) distance was measured using a marked court and tape measure. During a third testing day, subjects performed linear sprints from the batter’s box to first-base. Time was recorded at the foul-line and first-base using hand-held stop watches. Acceleration was computed between the two 13.7 meter intervals to first-base: home-plate to the foul-line (PURE) and foul-line to first-base (TRANS). Pearson’s r were calculated between PURE and TRANS and the anthropometric and performance data. Alpha was set a p \u3c 0.05 which equated to r = 0.44 for df = 18. Results: Of the tested variables, PURE was only associated with %Fat (r = -0.50), TRANS was significantly correlated with %Fat (r = -0.61), VJ (r = -0.50), and PP rel (r \=-0.51). Conclusion: These preliminary data indicate a primary determinant of pure acceleration to first-base is %Fat. VJ and PP relative to body mass are also associated with acceleration from the foul-line to first-base. Interesting, body mass was not related to acceleration in either phase. Therefore, strength and conditioning programs that reduce body fat and develop increased peak vertical power capabilities may be helpful in improving overall acceleration to first-base

Microarray analysis of human leucocyte subsets: the advantages of positive selection and rapid purification.

BACKGROUND: For expression profiling to have a practical impact in the management of immune-related disease it is essential that it can be applied to peripheral blood cells. Early studies have used total peripheral blood mononuclear cells, and as a consequence the majority of the disease-related signatures identified have simply reflected differences in the relative abundance of individual cell types between patients and controls. To identify cell-specific changes in transcription it would be necessary to profile purified leucocyte subsets. RESULTS: We have used sequential rounds of positive selection to isolate CD4 and CD8 T cells, CD19 B cells, CD14 monocytes and CD16 neutrophils for microarray analysis from a single blood sample. We compared gene expression in cells isolated in parallel using either positive or negative selection and demonstrate that there are no significant consistent changes due to positive selection, and that the far inferior results obtained by negative selection are largely due to reduced purity. Finally, we demonstrate that storing cells prior to separation leads to profound changes in expression, predominantly in cells of the myeloid lineage. CONCLUSION: Leukocyte subsets should be prepared for microarray analysis by rapid positive selection.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

The evolution of substructure II: linking dynamics to environment

We present results from a series of high-resolution N-body simulations that focus on the formation and evolution of eight dark matter halos, each of order a million particles within the virial radius. We follow the time evolution of hundreds of satellite galaxies with unprecedented time resolution, relating their physical properties to the differing halo environmental conditions. The self-consistent cosmological framework in which our analysis was undertaken allows us to explore satellite disruption within live host potentials, a natural complement to earlier work conducted within static potentials. Our host halos were chosen to sample a variety of formation histories, ages, and triaxialities; despite their obvious differences, we find striking similarities within the associated substructure populations. Namely, all satellite orbits follow nearly the same eccentricity distribution with a correlation between eccentricity and pericentre. We also find that the destruction rate of the substructure population is nearly independent of the mass, age, and triaxiality of the host halo. There are, however, subtle differences in the velocity anisotropy of the satellite distribution. We find that the local velocity bias at all radii is greater than unity for all halos and this increases as we move closer to the halo centre, where it varies from 1.1 to 1.4. For the global velocity bias we find a small but slightly positive bias, although when we restrict the global velocity bias calculation to satellites that have had at least one orbit, the bias is essentially removed.Comment: 14 pages, 14 figures, MNRAS in pres

Can we avoid high coupling?

It is considered good software design practice to organize source code into modules and to favour within-module connections (cohesion) over between-module connections (coupling), leading to the oft-repeated maxim "low coupling/high cohesion". Prior research into network theory and its application to software systems has found evidence that many important properties in real software systems exhibit approximately scale-free structure, including coupling; researchers have claimed that such scale-free structures are ubiquitous. This implies that high coupling must be unavoidable, statistically speaking, apparently contradicting standard ideas about software structure. We present a model that leads to the simple predictions that approximately scale-free structures ought to arise both for between-module connectivity and overall connectivity, and not as the result of poor design or optimization shortcuts. These predictions are borne out by our large-scale empirical study. Hence we conclude that high coupling is not avoidable--and that this is in fact quite reasonable

Inverse Melting of an Electronic Liquid Crystal

Inverse melting refers to the rare thermodynamic phenomenon in which a solid melts into a liquid upon cooling, a transition that can occur only when the ordered (solid) phase has more entropy than the disordered (liquid) phase, and that has so far only been observed in a handful of systems. Here we report the first experimental observation for the inverse melting of an electronic liquid crystalline order in strontium-doped lanthanum nickelate, a compound isostructural with the superconducting cuprates, with a hole doping concentration of 1/3. Using x-ray scattering, we demonstrate that the isotropic charge modulation is driven to nematic order by fluctuating spins and shows an inverse melting transition. Using a phenomenological Landau theory, we show that this inverse melting transition is due to the interlayer coupling between the charge and spin orders. This discovery points to the importance of the interlayer correlations in the system, and provides a new perspective to study the intricate nature of the electronic liquid crystal phases in strongly correlated electronic systems, including possibly the Cu- and Fe-based high-Tc superconductors.Comment: 7 pages, 7 figure

Inverse order-disorder transition of charge stripes

We report an unusual transition behavior of charge stripes in La1.67Sr0.33NiO4 using x-ray scattering. The segregated holes in La1.67Sr0.33NiO4 are observed to form anisotropic stripes in the a × b plane of the crystal space below the transition temperature T 238 K, and at the same time, display an unusual inverse order-disorder transition along the c axis. Using a phenomenological Landau theory, we show that this inverse transition is due to the interlayer coupling between the charge and spin orders. This discovery points to the importance of the interlayer correlations in the strongly correlated electrons system

Sussing merger trees: the Merger Trees Comparison Project

Merger trees follow the growth and merger of dark-matter haloes over cosmic history. As well as giving important insights into the growth of cosmic structure in their own right, they provide an essential backbone to semi-analytic models of galaxy formation. This paper is the first in a series to arise from the Sussing Merger Trees Workshop in which 10 different tree-building algorithms were applied to the same set of halo catalogues and their results compared. Although many of these codes were similar in nature, all algorithms produced distinct results. Our main conclusions are that a useful merger-tree code should possess the following features: (i) the use of particle IDs to match haloes between snapshots; (ii) the ability to skip at least one, and preferably more, snapshots in order to recover subhaloes that are temporarily lost during merging; (iii) the ability to cope with (and ideally smooth out) large, temporary fluctuations in halo mass. Finally, to enable different groups to communicate effectively, we defined a common terminology that we used when discussing merger trees and we encourage others to adopt the same language. We also specified a minimal output format to record the results

Mental health problems in people with learning disabilities: prevention, assessment and management

This guideline covers preventing, assessing and managing mental health problems in people with learning disabilities in all settings (including health, social care, education, and forensic and criminal justice). It aims to improve assessment and support for mental health conditions, and help people with learning disabilities and their families and carers to be involved in their care

The evolution of early-type galaxies at z~1 from the K20 survey

We have performed VLT spectroscopy of an almost complete sample of 18 early-type galaxies with 0.88 < z < 1.3 plus two at z=0.67, selected from the K20 survey, and derived the velocity dispersion for 15+2 of them. By combining these data with HST and VLT images, we study the Fundamental Plane (FP), the Faber-Jackson and the Kormendy relations at z~1, and compare them with the local ones. The FP at z~1 keeps a remarkably small scatter, and shows both an offset and a rotation, which we interpret in terms of evolution of the mass-to-light ratio, and possibly of the size. We show evidence that the evolution rate depends on galaxy mass, being faster for less massive galaxies. We discuss the possible factors driving the evolution of spheroids and compare our results with the predictions of the hierachical models of galaxy formation.Comment: 14 pages, 15 figures, accepted by A&