THE BIOMECHANICAL ANALYSIS OF THE ONE-HANDED AND TWO-HANDED BACKSTROKE IN TENNIS

The purpose of this study was to identify and analyze similarities and differences in spinal movement patterns between the one-handed and two-handed backswing in tennis (1) quantify the angles in degrees in the coronal, sagittal, and transverse planes (2) determine if the CA-6000 Spine Motion Analyzer (electrogoniometry) is an appropriate instrument to evaluate high velocity dynamic sport movements. A temporal and spatial relationship in a-p flexion, lateral bending, and axial rotation evaluated. These variables were compared for 8 elite tennis players, 5 male and 3 female. This descriptive study found that from the elgon tracings there was a greater degree of rotation and lateral bending for the two-handed back hitters when compared with the one-handed hitters; and all of the players exhibited forward flexion. Many of the players produced distinctive spinal patterns when performing the dynamic tennis stroke. In the basic static standing movement, many of the tracings were similar

WHAT YOU SHOULD KNOW ABOUT HOG CHOLERA

I. WHAT IS HOG CHOLERA? Hog cholera is a deadly, contagious disease that attacks swine only. The disease is caused by hog cholera virus, an agent so small (1/250,000 of an inch) that it can even pass through a fine porcelain filter. How do hogs act when they get the disease? They lie around hiding in their nest, have high fevers, are extremely weak and sick all over. They have little appetite, and often stand in a thinking attitude-motionless, tail relaxed, ears hanging limp, and the head slightly lowered as if in deep thought. Very few hogs ever recover. II. How IMPORTANT Is HOG CHOLERA? Hog cholera is the most important disease of hogs in the United States today. Farmers lose millions of dollars worth of hogs from cholera each year. And the expense of annually vaccinating millions of hogs costs even more. Many foreign markets are closed to pork from the United States because of the fear of importing hog cholera. The disease is important enough so that both state and federal governments have enacted regulatory measures and classed it as a reportable disease. In addition, the United States Congress has authorized the Secretary of Agriculture to enter into a marketing agreement with the hog cholera serum-virus industry. The original act was intended to provide that there should always be enough anti-hog cholera serum on hand to safeguard against sudden widespread outbreaks of the disease. Nevertheless, stocks of antiserum are being reduced every year

General relativistic spinning fluids with a modified projection tensor

An energy-momentum tensor for general relativistic spinning fluids compatible with Tulczyjew-type supplementary condition is derived from the variation of a general Lagrangian with unspecified explicit form. This tensor is the sum of a term containing the Belinfante-Rosenfeld tensor and a modified perfect-fluid energy-momentum tensor in which the four-velocity is replaced by a unit four-vector in the direction of fluid momentum. The equations of motion are obtained and it is shown that they admit a Friedmann-Robertson-Walker space-time as a solution.Comment: Submitted to General Relativity and Gravitatio

Scenario of Accelerating Universe from the Phenomenological \Lambda- Models

Dark matter, the major component of the matter content of the Universe, played a significant role at early stages during structure formation. But at present the Universe is dark energy dominated as well as accelerating. Here, the presence of dark energy has been established by including a time-dependent $\Lambda$ term in the Einstein's field equations. This model is compatible with the idea of an accelerating Universe so far as the value of the deceleration parameter is concerned. Possibility of a change in sign of the deceleration parameter is also discussed. The impact of considering the speed of light as variable in the field equations has also been investigated by using a well known time-dependent $\Lambda$ model.Comment: Latex, 9 pages, Major change

Ecological model of extinctions

We present numerical results based on a simplified ecological system in evolution, showing features of extinction similar to that claimed for the biosystem on Earth. In the model each species consists of a population in interaction with the others, that reproduces and evolves in time. Each species is simultaneously a predator and a prey in a food chain. Mutations that change the interactions are supposed to occur randomly at a low rate. Extinctions of populations result naturally from the predator-prey dynamics. The model is not pinned in a fitness variable, and natural selection arises from the dynamics.Comment: 16 pages (LaTeX type, RevTeX style), including 6 figures in gif format. To be published in Phys. Rev. E (prob. Dic. 96

An OSSE Search for the Binary Radio Pulsar 1259-63

We have searched data from the Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma Ray Observatory (GRO) for evidence of low‐energy γ‐ray emission from the binary radio pulsar PSR1259−63. This 47 ms pulsar is in a long‐period, highly eccentric orbit around a Be stellar companion and was observed by OSSE approximately 400 days after periastron. The period derivative allowed by the published radio ephemeris (Johnston et al. 1992) suggests that the pulsar might be relatively young, and therefore a γ‐ray source. However, the ephemeris is not sufficiently accurate to allow the traditional epoch‐folding technique over the full OSSE observation. Instead, the OSSE data were analyzed using Fourier transform spectral techniques after applying trial accelerations to correct for a range of possible orbital accelerations. We searched 48 accelerations; each FFT was 2 ^2^9 points sampled at 2 ms, spanning ∼106 seconds of observation time. There was no evidence of pulsed emission in the 64–150 keV band, with a 99.9% confidence upper limit of 6×10^(−)3 photons cm^(−2) s^(−1) MeV− 1 or ∼40 m Crab pulsars, which suggests that the pulsar’s intrinsic period derivative is small and its magnetic field weak. This work was performed on the Concurrent Supercomputing Consortium’s Intel Touchstone Delta parallel supercomputer as part of a GRO Phase 1 Guest Investigation

Relativistic Electromagnetic Mass Models: Charged Dust Distribution in Higher Dimensions

Electromagnetic mass models are proved to exist in higher dimensional theory of general relativity corresponding to charged dust distribution. Along with the general proof a specific example is also sited as a supporting candidate.Comment: Latex, 7 pages. Accepted in Astrophysics and Space Scienc

Surface state engineering of molecule-molecule interactions

Engineering the electronic structure of organics through interface manipulation, particularly the interface dipole and the barriers to charge carrier injection, is of essential importance to improved organic devices. This requires the meticulous fabrication of desired organic structures by precisely controlling the interactions between molecules. The well-known principles of organic coordination chemistry cannot be applied without proper consideration of extra molecular hybridization, charge transer and dipole formation at the interfaces. Here we identify the interplay between energy level alignment, charge transfer, surface dipole and charge pillow effect and show how these effects collectively determine the net force between adsorbed porphyrin 2H-TPP on Cu(111). We show that the forces between supported porphyrins can be altered by controlling the amount of charge transferred across the interface accurately through the relative alignment of molecular electronic levels with respect to the Shockley surface state of the metal substrate, and hence govern the self-assembly of the molecules

Auroral evidence of radial transport at Jupiter during January 2014

We present Jovian auroral observations from the 2014 January Hubble Space Telescope (HST) campaign and investigate the auroral signatures of radial transport in the magnetosphere alongside contemporaneous radio and Hisaki EUV data. HST FUV auroral observations on day 11 show, for the first time, a significantly superrotating polar spot poleward of the main emission on the dawnside. The spot transitions from the polar to main emission region in the presence of a locally broad, bright dawnside main emission feature and two large equatorward emission features. Such a configuration of the main emission region is also unreported to date. We interpret the signatures as part of a sequence of inward radial transport processes. Hot plasma inflows from tail reconnection are thought to flow planetward and could generate the superrotating spot. The main emission feature could be the result of flow shears from prior hot inflows. Equatorward emissions are observed. These are evidence of hot plasma injections in the inner magnetosphere. The images are thought to be part of a prolonged period of reconnection. Radio emissions measured by Wind suggest that hectometric (HOM) and non-Io decametric (DAM) signatures are associated with the sequence of auroral signatures, which implies a global magnetospheric disturbance. The reconnection and injection interval can continue for several hours

Persistence in higher dimensions : a finite size scaling study

We show that the persistence probability $P(t,L)$, in a coarsening system of linear size $L$ at a time $t$, has the finite size scaling form $P(t,L)\sim L^{-z\theta}f(\frac{t}{L^{z}})$ where $\theta$ is the persistence exponent and $z$ is the coarsening exponent. The scaling function $f(x)\sim x^{-\theta}$ for $x \ll 1$ and is constant for large $x$. The scaling form implies a fractal distribution of persistent sites with power-law spatial correlations. We study the scaling numerically for Glauber-Ising model at dimension $d = 1$ to 4 and extend the study to the diffusion problem. Our finite size scaling ansatz is satisfied in all these cases providing a good estimate of the exponent $\theta$.Comment: 4 pages in RevTeX with 6 figures. To appear in Phys. Rev.