829 research outputs found
Status of undergraduate community-based and public-health physiotherapy education in South Africa
Curricula of health education institutions therefore need to
be periodically revised to be aligned with its context. This study explored the
status physiotherapy curricula in South Africa (SA) as point of departure for
benchmarking by individual institutions.
A document analysis was done of the university physiotherapy departments
(N=8) in South Africa. Institutional ethical clearance and permission from the
heads of departments were obtained. Content analysis was used to analyse the
South African Qualifications Authority exit-level outcomes and the university
study guides for community placements.
Most universities employed a form of service-learning, with interventions in
a range of settings. Five themes emerged: practice of evidence-based physiotherapy,
rendering physiotherapy services, acting professionally, communication,
and collaboration. The country’s priority conditions were addressed.
Teaching-earning strategies included group activities (class or education sessions), community projects, home visits and portfolios
of evidence. Personal and small-group reflections were prominent.
The undergraduate community physiotherapy curricula in South Africa address the health profile of the population and priorities
in the health system to different degrees. The variation between universities should be interpreted with caution as the study guides
only gave a limited snapshot into each institution’s curriculum. However, findings suggest that each physiotherapy university
department may have gaps in preparing physiotherapy undergraduate students for the needs of the South African population and
expectations of the Government. Possible ways to share teaching-learning resources are recommended.Department of HE and Training approved lis
Space Symmetries and Quantum Behavior of Finite Energy Configurations in SU(2)-Gauge Theory
The quantum properties of localized finite energy solutions to classical
Euler-Lagrange equations are investigated using the method of collective
coordinates. The perturbation theory in terms of inverse powers of the coupling
constant is constructed, taking into account the conservation laws of
momentum and angular momentum (invariance of the action with respect to the
group of motion M(3) of 3-dimensional Euclidean space) rigorously in every
order of perturbation theory.Comment: LaTex, 17 pages typos correcte
Magnetic Flux Expulsion in the Powerful Superbubble Explosions and the Alpha-Omega Dynamo
The possibility of the magnetic flux expulsion from the Galaxy in the
superbubble (SB) explosions, important for the Alpha-Omega dynamo, is
considered. Special emphasis is put on the investigation of the downsliding of
the matter from the top of the shell formed by the SB explosion which is able
to influence the kinematics of the shell. It is shown that either Galactic
gravity or the development of the Rayleigh-Taylor instabilities in the shell
limit the SB expansion, thus, making impossible magnetic flux expulsion. The
effect of the cosmic rays in the shell on the sliding is considered and it is
shown that it is negligible compared to Galactic gravity. Thus, the question of
possible mechanism of flux expulsion in the Alpha-Omega dynamo remains open.Comment: MNRAS, in press, 11 pages, 9 figure
Logarithmic perturbation theory for quasinormal modes
Logarithmic perturbation theory (LPT) is developed and applied to quasinormal
modes (QNMs) in open systems. QNMs often do not form a complete set, so LPT is
especially convenient because summation over a complete set of unperturbed
states is not required. Attention is paid to potentials with exponential tails,
and the example of a Poschl-Teller potential is briefly discussed. A numerical
method is developed that handles the exponentially large wavefunctions which
appear in dealing with QNMs.Comment: 24 pages, 4 Postscript figures, uses ioplppt.sty and epsfig.st
Steps in the bacterial flagellar motor
The bacterial flagellar motor is a highly efficient rotary machine used by
many bacteria to propel themselves. It has recently been shown that at low
speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437,
916--919]. Here we propose a simple physical model that accounts for this
stepping behavior as a random walk in a tilted corrugated potential that
combines torque and contact forces. We argue that the absolute angular position
of the rotor is crucial for understanding step properties, and show this
hypothesis to be consistent with the available data, in particular the
observation that backward steps are smaller on average than forward steps. Our
model also predicts a sublinear torque-speed relationship at low torque, and a
peak in rotor diffusion as a function of torque
Small denominators, frequency operators, and Lie transforms for nearly integrable quantum spin systems
Based on the previously proposed notions of action operators and of quantum integrability, frequency operators are introduced in a fully quantum-mechanical setting. They are conceptually useful because another formulation can be given to unitary perturbation theory. When worked out for quantum spin systems, this variant is found to be formally equivalent to canonical perturbation theory applied to nearly integrable systems consisting of classical spins. In particular, it becomes possible to locate the quantum-mechanical operator-valued equivalent of the frequency denominators that may cause divergence of the classical perturbation series. The results that are established here link the concept of quantum-mechanical integrability to a technical question, namely, the behavior of specific perturbation series
Conserving Gapless Mean-Field Theory for Weakly Interacting Bose Gases
This paper presents a conserving gapless mean-field theory for weakly
interacting Bose gases. We first construct a mean-field Luttinger-Ward
thermodynamic functional in terms of the condensate wave function and
the Nambu Green's function for the quasiparticle field. Imposing its
stationarity respect to and yields a set of equations to
determine the equilibrium for general non-uniform systems. They have a
plausible property of satisfying the Hugenholtz-Pines theorem to provide a
gapless excitation spectrum. Also, the corresponding dynamical equations of
motion obey various conservation laws. Thus, the present mean-field theory
shares two important properties with the exact theory: ``conserving'' and
``gapless.'' The theory is then applied to a homogeneous weakly interacting
Bose gas with s-wave scattering length and particle mass to clarify its
basic thermodynamic properties under two complementary conditions of constant
density and constant pressure . The superfluid transition is predicted
to be first-order because of the non-analytic nature of the order-parameter
expansion near inherent in Bose systems, i.e., the Landau-Ginzburg
expansion is not possible here. The transition temperature shows quite
a different interaction dependence between the -fixed and -fixed cases.
In the former case increases from the ideal gas value as
, whereas it decreases in the latter as
. Temperature dependences of
basic thermodynamic quantities are clarified explicitly.Comment: 19 pages, 8 figure
Use of Modal Acoustic Emission to Monitor Damage Progression in Carbon Fiber/Epoxy Tows and Implications for Composite Structures
This slide presentation reviews the use of Modal Acoustic Emission to monitor damage progression to carbon fiber/epoxy tows. There is a risk for catastrophic failure of composite overwrapped pressure vessels (COPVs) due to burst-before-leak (BBL) stress rupture (SR) failure of carbon-epoxy (C/Ep) COPVs. A lack of quantitative nondestructive evaluation (NDE) is causing problems in current and future spacecraft designs. It is therefore important to develop and demonstrate critical NDE that can be implemented during stages of the design process since the observed rupture can occur with little of no advanced warning. Therefore a program was required to develop quantitative acoustic emission (AE) procedures specific to C/Ep overwraps, but which also have utility for monitoring damage accumulation in composite structure in general, and to lay the groundwork for establishing critical thresholds for accumulated damage in composite structures, such as COPVs, so that precautionary or preemptive engineering steps can be implemented to minimize of obviate the risk of catastrophic failure. A computed Felicity Ratio (FR) coupled with fast Fourier Transform (FFT) frequency analysis shows promise as an analytical pass/fail criterion. The FR analysis and waveform and FFT analysis are reviewe
Stochastic Cellular Automata Model for Stock Market Dynamics
In the present work we introduce a stochastic cellular automata model in
order to simulate the dynamics of the stock market. A direct percolation method
is used to create a hierarchy of clusters of active traders on a two
dimensional grid. Active traders are characterised by the decision to buy,
(+1), or sell, (-1), a stock at a certain discrete time step. The remaining
cells are inactive,(0). The trading dynamics is then determined by the
stochastic interaction between traders belonging to the same cluster. Most of
the stylized aspects of the financial market time series are reproduced by the
model.Comment: 17 pages and 7 figure
Perturbative Approach to the Quasinormal Modes of Dirty Black Holes
Using a recently developed perturbation theory for uasinormal modes (QNM's),
we evaluate the shifts in the real and imaginary parts of the QNM frequencies
due to a quasi-static perturbation of the black hole spacetime. We show the
perturbed QNM spectrum of a black hole can have interesting features using a
simple model based on the scalar wave equation.Comment: Published in PR
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