1,960 research outputs found
THE EFFECT OF INDIVIDUALISED COACHING INTERVENTIONS ON ELITE YOUNG FAST BOWLERS‘ TECHNIQUE
Fast bowling in cricket is an activity well recognised as having a high injury prevalence. Previous research has associated lower back injury with aspects of fast bowling technique. Coaching interventions that may decrease the likelihood of injury, whilst maintaining or increasing ball speed, remain a priority within the sport. Selected kinematics of the bowling action of 14 elite young fast bowlers were measured using an 18 camera Vicon Motion Analysis System. Subjects were tested before and after a two year coaching intervention period, during which subject-specific coaching interventions were provided. Mann-Whitney tests were used to identify significant differences in the change in the selected kinematics between those bowlers who were coached or un-coached on each specific aspect. Coached athletes demonstrated a significant change in shoulder alignment at back foot contact (more side-on, P = 0.002) and shoulder counter-rotation (decreased, P = 0.001) relative to un-coached athletes. There was no difference in the amount of change in flexion angles of the front or back knee or lower trunk side-flexion between those who received coaching intervention and those that did not. This study shows that specific aspects of fast bowling technique in elite players can change over a two year period and may be attributed to coaching intervention
Ideal based graph structures for commutative rings
We introduce a graph structure \gamrr for commutative rings with unity. We study some of the properties of the graph \gamrr. Also we study some parameters of \gamrr and find rings for which \gamrr is split
Horizontal flow fields observed in Hinode G-band images. I. Methods
Context: The interaction of plasma motions and magnetic fields is an
important mechanism, which drives solar activity in all its facets. For
example, photospheric flows are responsible for the advection of magnetic flux,
the redistribution of flux during the decay of sunspots, and the built-up of
magnetic shear in flaring active regions. Aims: Systematic studies based on
G-band data from the Japanese Hinode mission provide the means to gather
statistical properties of horizontal flow fields. This facilitates comparative
studies of solar features, e.g., G-band bright points, magnetic knots, pores,
and sunspots at various stages of evolution and in distinct magnetic
environments, thus, enhancing our understanding of the dynamic Sun. Methods: We
adapted Local Correlation Tracking (LCT) to measure horizontal flow fields
based on G-band images obtained with the Solar Optical Telescope on board
Hinode. In total about 200 time-series with a duration between 1-16 h and a
cadence between 15-90 s were analyzed. Selecting both a high-cadence (dt = 15
s) and a long-duration (dT = 16 h) time-series enabled us to optimize and
validate the LCT input parameters, hence, ensuring a robust, reliable, uniform,
and accurate processing of a huge data volume. Results: The LCT algorithm
produces best results for G-band images having a cadence of 60-90 s. If the
cadence is lower, the velocity of slowly moving features will not be reliably
detected. If the cadence is higher, the scene on the Sun will have evolved too
much to bear any resemblance with the earlier situation. Consequently, in both
instances horizontal proper motions are underestimated. The most reliable and
yet detailed flow maps are produced using a Gaussian kernel with a size of 2560
km x 2560 km and a full-width-at-half-maximum (FWHM) of 1200 km (corresponding
to the size of a typical granule) as sampling window.Comment: 12 pages, 8 figures, 4 tables, accepted for publication in Astronomy
and Astrophysic
Quiet Sun internetwork magnetic fields from the inversion of Hinode measurements
We analyze Fe I 630 nm observations of the quiet Sun at disk center taken
with the spectropolarimeter of the Solar Optical Telescope aboard the Hinode
satellite. A significant fraction of the scanned area, including granules,
turns out to be covered by magnetic fields. We derive field strength and
inclination probability density functions from a Milne-Eddington inversion of
the observed Stokes profiles. They show that the internetwork consists of very
inclined, hG fields. As expected, network areas exhibit a predominance of kG
field concentrations. The high spatial resolution of Hinode's
spectropolarimetric measurements brings to an agreement the results obtained
from the analysis of visible and near-infrared lines.Comment: To appear in ApJ letter
A Tale Of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere
We use high-resolution observations of the Sun in Ca II H 3968 A from the
Solar Optical Telescope on Hinode to show that there are at least two types of
spicules that dominate the structure of the magnetic solar chromosphere. Both
types are tied to the relentless magnetoconvective driving in the photosphere,
but have very different dynamic properties. ``Type-I'' spicules are driven by
shock waves that form when global oscillations and convective flows leak into
the upper atmosphere along magnetic field lines on 3-7 minute timescales.
``Type-II'' spicules are much more dynamic: they form rapidly (in ~10s), are
very thin (<200km wide), have lifetimes of 10-150s (at any one height) and seem
to be rapidly heated to (at least) transition region temperatures, sending
material through the chromosphere at speeds of order 50-150 km/s. The
properties of Type II spicules suggest a formation process that is a
consequence of magnetic reconnection, typically in the vicinity of magnetic
flux concentrations in plage and network. Both types of spicules are observed
to carry Alfven waves with significant amplitudes of order 20 km/s.Comment: 8 pages, 5 figures, accepted for Hinode special issue of PAS
Vector spectropolarimetry of dark-cored penumbral filaments with Hinode
We present spectropolarimetric measurements of dark-cored penumbral filaments
taken with Hinode at a resolution of 0.3". Our observations demonstrate that
dark-cored filaments are more prominent in polarized light than in continuum
intensity. Far from disk center, the Stokes profiles emerging from these
structures are very asymmetric and show evidence for magnetic fields of
different inclinations along the line of sight, together with strong Evershed
flows of at least 6-7 km/s. In sunspots closer to disk center, dark-cored
penumbral filaments exhibit regular Stokes profiles with little asymmetries due
to the vanishing line-of-sight component of the horizontal Evershed flow. An
inversion of the observed spectra indicates that the magnetic field is weaker
and more inclined in the dark cores as compared with the surrounding bright
structures. This is compatible with the idea that dark-cored filaments are the
manifestation of flux tubes carrying hot Evershed flows.Comment: Accepted for publication in ApJ Letters. Use the Postscript version
for high quality figure
Strategy for the inversion of Hinode spectropolarimetric measurements in the quiet Sun
In this paper we propose an inversion strategy for the analysis of
spectropolarimetric measurements taken by {\em Hinode} in the quiet Sun. The
spectropolarimeter of the Solar Optical Telescope aboard {\em Hinode} records
the Stokes spectra of the \ion{Fe}{i} line pair at 630.2 nm with unprecendented
angular resolution, high spectral resolution, and high sensitivity. We discuss
the need to consider a {\em local} stray-light contamination to account for the
effects of telescope diffraction. The strategy is applied to observations of a
wide quiet Sun area at disk center. Using these data we examine the influence
of noise and initial guess models in the inversion results. Our analysis yields
the distributions of magnetic field strengths and stray-light factors. They
show that quiet Sun internetwork regions consist mainly of hG fields with
stray-light contaminations of about 0.8.Comment: To appear in Publications of the Astronomical Society of Japan, 8
pages, 10 figure
Variability in content and dissolution profiles of MDMA tablets collected in the UK between 2001 and 2018-A potential risk to users?
Official Student Newspaper
Issue is 12 pages long
Effect of Medicaid Expansion on Cancer Treatment and Survival Among Medicaid Beneficiaries and the Uninsured
BACKGROUND: The Affordable Care Act expanded Medicaid coverage for people with low income in the United States. Expanded insurance coverage could promote more timely access to cancer treatment, which could improve overall survival (OS), yet the long-term effects of Medicaid expansion (ME) remain unknown. We evaluated whether ME was associated with improved timely treatment initiation (TTI) and 3-year OS among patients with breast, cervical, colon, and lung cancers who were affected by the policy.
METHODS: Medicaid-insured or uninsured patients aged 40-64 with stage I-III breast, cervical, colon, or non-small cell lung cancer within the National Cancer Database (NCDB). A difference-in-differences (DID) approach was used to compare changes in TTI (within 60 days) and 3-year OS between patients in ME states versus nonexpansion (NE) states before (2010-2013) and after (2015-2018) ME. Adjusted DID estimates for TTI and 3-year OS were calculated using multivariable linear regression and Cox proportional hazards regression models, respectively.
RESULTS: ME was associated with a relative increase in TTI within 60 days for breast (DID = 4.6; p \u3c 0.001), cervical (DID = 5.0 p = 0.013), and colon (DID = 4.0, p = 0.008), but not lung cancer (p = 0.505). In Cox regression analysis, ME was associated with improved 3-year OS for breast (DID hazard ratio [HR] = 0.82, p = 0.009), cervical (DID-HR = 0.81, p = 0.048), and lung (DID-HR = 0.87, p = 0.003). Changes in 3-year OS for colon cancer were not statistically different between ME and NE states (DID-HR, 0.77; p = 0.075).
CONCLUSIONS: Findings suggest that expanded insurance coverage can improve treatment and survival outcomes among low income and uninsured patients with cancer. As the debate surrounding ME continues nationwide, our findings serve as valuable insights to inform the development of policies aimed at fostering accessible and affordable healthcare for all
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