Effect of a 6-week yoga intervention on swing mechanics during the golf swing:a feasibility study

Recent evidence suggests that participating in physical conditioning programmes can improve golf performance, however, the effectiveness of a yoga intervention has yet to be investigated. The aim of the current study was to investigate the effectiveness of a six-week yoga intervention on golf swing mechanics. Ten male golfers participated in the laboratory-based-study. Golf swing mechanics were collected from two testing sessions, before and after the six-week yoga intervention, using the Vicon motion capture system. Following the six-week yoga intervention, significant changes were observed between the yoga and control group in X-Factor (P ≤ 0.05) and a medium effect (d ≥ 0.50) observed. No significant changes (P > 0.05) and no effect (d < 0.20) were observed in the X-Factor stretch. Significant changes (P ≤ 0.05) and a medium effect (d > 0.50) were observed for the pelvis rotations following the yoga intervention, however, no differences were observed in torso rotations or hand velocities (P > 0.05). The findings of this feasibility study suggest that yoga may be a promising intervention in helping to improve golf swing mechanics, however, future research is required to confirm the effect of the use of yoga during the golf swing due to the sample size

The SNARE Protein Syntaxin 3 Confers Specificity for Polarized Axonal Trafficking in Neurons.

Cell polarity and precise subcellular protein localization are pivotal to neuronal function. The SNARE machinery underlies intracellular membrane fusion events, but its role in neuronal polarity and selective protein targeting remain unclear. Here we report that syntaxin 3 is involved in orchestrating polarized trafficking in cultured rat hippocampal neurons. We show that syntaxin 3 localizes to the axonal plasma membrane, particularly to axonal tips, whereas syntaxin 4 localizes to the somatodendritic plasma membrane. Disruption of a conserved N-terminal targeting motif, which causes mislocalization of syntaxin 3, results in coincident mistargeting of the axonal cargos neuron-glia cell adhesion molecule (NgCAM) and neurexin, but not transferrin receptor, a somatodendritic cargo. Similarly, RNAi-mediated knockdown of endogenous syntaxin 3 leads to partial mistargeting of NgCAM, demonstrating that syntaxin 3 plays an important role in its targeting. Additionally, overexpression of syntaxin 3 results in increased axonal growth. Our findings suggest an important role for syntaxin 3 in maintaining neuronal polarity and in the critical task of selective trafficking of membrane protein to axons

Simulations of momentum feedback by black hole winds

The observed super-massive black hole (SMBH) mass -- galaxy velocity dispersion ($M_{\rm bh} - \sigma$) correlation may be established when winds/outflows from the SMBH drive gas out of the potential wells of classical bulges. Here we present numerical simulations of this process in a static isothermal potential. Simple spherically symmetric models of SMBH feedback at the Eddington luminosity can successfully explain the $M_{\rm bh} - \sigma$ and nuclear cluster mass $M_{\rm NC}-\sigma$ correlations, as well as why larger bulges host SMBHs while smaller ones host nuclear star clusters. However these models do not specify how SMBHs feed on infalling gas whilst simultaneously producing feedback that drives gas out of the galaxy. More complex models with rotation and/or anisotropic feedback allow SMBHs to feed via a disc or regions not exposed to SMBH winds, but in these more realistic cases it is not clear why a robust $M_{\rm bh} - \sigma$ relation should be established. In fact, some of the model predictions contradict observations. For example, an isotropic SMBH wind impacting on a disc (rather than a shell) of aspect ratio $H/R \ll 1$ requires the SMBH mass to be larger by a factor $\sim R/H$, which is opposite to what is observed. We conclude that understanding how a SMBH feeds is as important a piece of the puzzle as understanding how its feedback affects its host galaxy. Finally, we note that in aspherical cases the SMBH outflows induce differential motions in the bulge. This may pump turbulence that is known to hinder star formation in star forming regions. SMBH feedback thus may not only drive gas out of the bulge but also reduce the fraction of gas turned into stars.Comment: 17 pages, to appear in MNRA

The Structure of Liquid and Amorphous Hafnia.

Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an average Hf-O coordination number of ~7 exists in both the liquid and amorphous nanoparticle forms studied. The measured pair distribution functions are compared to those generated from several simulation models in the literature. We have also performed ab initio and classical molecular dynamics simulations that show density has a strong effect on the polyhedral connectivity. The liquid shows a broad distribution of Hf-Hf interactions, while the formation of low-density amorphous nanoclusters can reproduce the sharp split peak in the Hf-Hf partial pair distribution function observed in experiment. The agglomeration of amorphous nanoparticles condensed from the gas phase is associated with the formation of both edge-sharing and corner-sharing HfO6,7 polyhedra resembling that observed in the monoclinic phase

BIOMECHANICAL SIMILARITIES OF LONGSWINGS AT VARYING SPEEDS AND THE KOVACS ACTION

INTRODUCTION: Low movement variability in the backward longswing has been partly attributed to external competitive constraints (Irwin & Kerwin, 2005). However, a number of high level skills (e.g. Gienger, Deff, Kovacs) derive from variations in the longswing action. If movement variability is viewed as having a functional role (Bartlett et al., 2007) then variability in the longswing might be beneficial to subsequent skill acquisition. This study aims to determine whether variations in the speed of longswing can induce movements thatare more similar to movements associated with a high level skill, in this case the Kovacs

Feeding SMBHs through supersonic turbulence and ballistic accretion

It has long been recognised that the main obstacle to accretion of gas onto supermassive black holes (SMBHs) is large specific angular momentum. It is feared that the gas settles in a large scale disc, and that accretion would then proceed too inefficiently to explain the masses of the observed SMBHs. Here we point out that, while the mean angular momentum in the bulge is very likely to be large, the deviations from the mean can also be significant. Indeed, cosmological simulations show that velocity and angular momentum fields of gas flows onto galaxies are very complex. Furthermore, inside bulges the gas velocity distribution can be further randomised by the velocity kicks due to feedback from star formation. We perform hydrodynamical simulations of gaseous rotating shells infalling onto an SMBH, attempting to quantify the importance of velocity dispersion in the gas at relatively large distances from the black hole. We implement this dispersion by means of a supersonic turbulent velocity spectrum. We find that, while in the purely rotating case the circularisation process leads to efficient mixing of gas with different angular momentum, resulting in a low accretion rate, the inclusion of turbulence increases this accretion rate by up to several orders of magnitude. We show that this can be understood based on the notion of "ballistic" accretion, whereby dense filaments, created by convergent turbulent flows, travel through the ambient gas largely unaffected by hydrodynamical drag. We derive a simple analytical formula that captures the numerical results to within a factor of a few. Rescaling our results to astrophysical bulges, we argue that this "ballistic" mode of accretion could provide the SMBHs with a sufficient supply of fuel without the need to channel the gas via large-scale discs or bars, and therefore that star formation in bulges can be a strong catalyst for SMBH accretion.Comment: 21 pages, 21 figures. Accepted and published by MNRA

The politics of regionalism and federation in East Africa, 1958-1964

Recent scholarship discussing the ‘federal moment’ in world history after 1945 has re-examined alternatives to the nation-state in the years of decolonisation, arguing against any inevitable transition from empire to nation. This article focuses on the case of East Africa, where federation seemed an attractive and likely prospect by 1963, yet never came to pass. Here the politics of federation should be understood as a constitutive part of the contested nation-state making process, rather than a viable alternative to it. For the leaders who initiated the politics of federation in the 1960s, regional unity promised the further centralisation of power, and a means of defeating tribalist opposition. For their opponents, federation was seized on as a means of promoting the autonomy of provinces or kingdoms within a larger federal unit. Yet ultimately, regionalist aspiration was inseparable from national politics: and negotiations among the leaders of East African states demanded the definition of national interests, which divided states rather than united them. Such conclusions suggest that historians of the federal moment might more productively focus on the functions of federalist discourse in the making of nation-states, rather than debating the viability of federalist projects

Detection of CFIRB with AKARI/FIS Deep Observations

The Cosmic Far-Infrared Background (CFIRB) contains information about the number and distribution of contributing sources and thus gives us an important key to understand the evolution of galaxies. Using a confusion study to set a fundamental limit to the observations, we investigate the potential to explore the CFIRB with AKARI/FIS deep observations. The Far-Infrared Surveyor (FIS) is one of the focal-plane instruments on the AKARI (formerly known as ASTRO-F) satellite, which was launched in early 2006. Based upon source distribution models assuming three different cosmological evolutionary scenarios (no evolution, weak evolution, and strong evolution), an extensive model for diffuse emission from infrared cirrus, and instrumental noise estimates, we present a comprehensive analysis for the determination of the confusion levels for deep far-infrared observations. We use our derived sensitivities to suggest the best observational strategy for the AKARI/FIS mission to detect the CFIRB fluctuations. If the source distribution follows the evolutionary models, observations will be mostly limited by source confusion. We find that we will be able to detect the CFIRB fluctuations and that these will in turn provide information to discriminate between the evolutionary scenarios of galaxies in most low-to-medium cirrus regions.Comment: 12 pages, 5 figures, uses elsart.cls, Accepted for publication in Advances in Space Research, 36th COSPAR Scientific Assembly Beijing, China, 16 ~ 23 July 200