22,629 research outputs found
Use of an audio-paced incremental swimming test in young national-level swimmers
Purpose:To evaluate the reliability and sensitivity to training of an audio-paced incremental swimming test.Methods:Eight young national-level male swimmers (age 15 ± 1 year) performed a 7 × 200-m incremental swimming test (velocities 1.19, 1.24, 1.28, 1.33, 1.39, and 1.45 m/s and maximal sprint pace) using an audio-pacing device. The same test was performed 4 times by each participant, 1 wk apart to assess reliability (WK1, WK2) and after 9 and 20 wk of training (WK9, WK20). Blood lactate concentration ([La−]) and heart rate (HR) were recorded after each stage. Outcome measures were the velocity (v) and HR at lactate markers of 2 mM, 4 mM, and Δ1 mM.Results:Velocities at the lactate markers proved to be more reliable than HR, with typical errors ranging from 0.66% to 2.30% and 1.28% to 4.50%, respectively (shifts in mean ranged –0.91% to 0.73% and –0.84% to 1.79%, respectively). Across WK1, WK9, and WK20 there were significant improvements in peak velocity (P < .001) and each of the velocities associated with the lactate markers (P < .05), whereas only HR at Δ1 mM improved (P < .05).Conclusions:This article demonstrates that an audio-paced incremental swimming test is reliable for use with junior swimmers and is sensitive to changes observed after training. The postswimming measurement of HR in the pool was comparatively less reliable.</jats:sec
Barotropic thin shells with linear EOS as models of stars and circumstellar shells in general relativity
The spherically symmetric thin shells of the barotropic fluids with the
linear equation of state are considered within the frameworks of general
relativity. We study several aspects of the shells as completely relativistic
models of stars, first of all the neutron stars and white dwarfs, and
circumstellar shells. The exact equations of motion of the shells are obtained.
Also we calculate the parameters of the equilibrium configurations, including
the radii of static shells. Finally, we study the stability of the equilibrium
shells against radial perturbations.Comment: final version; ps-version of figure is available by email request to
[email protected]
A Three-Dimensional Solution of Flows over Wings with Leading-Edge Vortex Separation. Part 2: Program Description Document
For abstract, see N75-32026
Reply to the comment by Carmelo Anile on the paper "Complexity analysis of the cerebrospinal fluid pulse waveform during infusion studies"
Veterinary technology is an emerging profession within the veterinary and allied animal health fields in Australia and affords graduates the opportunity to contribute to the small but growing body of literature within this discipline. This study describes the introduction of a contextualised assessment task to develop students’ research capability, competence and confidence in professional writing, and to engage them with the academic publishing process. Students worked in self-selected dyads to author a scientific case report, of publishable standard, based on authentic cases from their clinical practicum. Intrinsic to the task, students attended a series of workshops that explored topics such as critiquing the literature, professional writing styles and oral presentation skills. Assessment was multi-staged with progressive feedback, including peer review, and culminated with students presenting their abstracts at a mock conference. Students reported the task to be an enjoyable and valuable learning experience which improved their competence and confidence in scientific writing; supported by a comparison of previously submitted work. Linking scientific writing skills to clinical practice experiences enhanced learning outcomes and may foster the professionalisation of students within this emerging discipline
Symplectic N and time reversal in frustrated magnetism
Identifying the time reversal symmetry of spins as a symplectic symmetry, we
develop a large N approximation for quantum magnetism that embraces both
antiferromagnetism and ferromagnetism. In SU(N), N>2, not all spins invert
under time reversal, so we have introduced a new large N treatment which builds
interactions exclusively out of the symplectic subgroup [SP(N)] of time
reversing spins, a more stringent condition than the symplectic symmetry of
previous SP(N) large N treatments. As a result, we obtain a mean field theory
that incorporates the energy cost of frustrated bonds. When applied to the
frustrated square lattice, the ferromagnetic bonds restore the frustration
dependence of the critical spin in the Neel phase, and recover the correct
frustration dependence of the finite temperature Ising transition.Comment: added reference
Quantum replica approach to the under-screened Kondo model
We extend the Schwinger boson large N treatment of the underscreened Kondo
model in a way that correctly captures the finite elastic phase shift in the
singular Fermi liquid. The new feature of the approach, is the introduction of
a flavor quantum number with K possible values, associated with the Schwinger
boson representation. The large N limit is taken maintaining the ratio k=K/N
fixed. This approach differs from previous approaches, in that we do not
explicitly enforce a constraint on the spin representation of the Schwinger
bosons. Instead, the energetics of the Kondo model cause the bosonic degrees of
freedom to ``self assemble'' into a ground-state in which the spins of K bosons
and N-K conduction electrons are antisymmetrically arranged into a Kondo
singlet. With this device, the large N limit can be taken, in such a way that a
fraction K/N of the Abrikosov Suhl resonance is immersed inside the Fermi sea.
We show how this method can be used to model the full energy dependence of the
singular Abrikosov Suhl resonance in the underscreened Kondo model and the
field-dependent magnetization.Comment: Revised draft, with plots explicitly showing logarithmic scaling of
inverse coupling constant. Small corrections prior to submission to journa
Information of Structures in Galaxy Distribution
We introduce an information-theoretic measure, the Renyi information, to
describe the galaxy distribution in space. We discuss properties of the
information measure, and demonstrate its relationship with the probability
distribution function and multifractal descriptions. Using the First Look
Survey galaxy samples observed by the Infrared Array Camera onboard Spitzer
Space Telescope, we present measurements of the Renyi information, as well as
the counts-in-cells distribution and multifractal properties of galaxies in
mid-infrared wavelengths. Guided by multiplicative cascade simulation based on
a binomial model, we verify our measurements, and discuss the spatial selection
effects on measuring information of the spatial structures. We derive structure
scan functions at scales where selection effects are small for the Spitzer
samples. We discuss the results, and the potential of applying the Renyi
information to measuring other spatial structures.Comment: 25 pages, 8 figures, submitted to ApJ; To appear in The Astrophysical
Journal 2006, 644, 678 (June 20th
Apollo particles and fields subsatellite magnetometer experiment
The results of the Apollo 15 subsatellite magnetometer experiment are reported. The magnetometer is described including the operation, and specifications. Orbit plots presented are altitude versus time, selenographic longitude versus latitude, and the ecliptic projection of the earth-moon system. The lunar magnetic field, solar wind interaction with the moon, the transfer function of the moon, and the plasma sheet interaction with the moon are discussed
Globular Clusters and Dwarf Spheroidal Galaxies
Traditionally globular clusters and dwarf spheroidal galaxies have been
distinguished by using one or more of the following criteria: (1) mass, (2)
luminosity, (3) size, (4) mass-to-light ratio and (5) spread in metallicity.
However, a few recently discovered objects show some overlap between the
domains in parameter space that are occupied by galaxies and clusters. In the
present note it is shown that ellipticity can, in some cases, be used to help
distinguish between globular clusters and dwarf spheroidal galaxies.Comment: MNRAS (Letters), in pres
Multiple Lifshitz transitions driven by short-range antiferromagnetic correlations in the two-dimensional Kondo lattice model
With a mean field approach, the heavy Fermi liquid in the two-dimensional
Kondo lattice model is carefully considered in the presence of short-range
antiferromagnetic correlations. As the ratio of the local Heisenberg
superexchange coupling to the Kondo coupling increases, the Fermi surface
structure changes dramatically. From the analysis of the ground state energy
density, multiple Lifshitz type phase transitions occur at zero temperature.Comment: 4 pages, 3 figures, contribution to SCES201
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