5,189 research outputs found
Trends in the availability and usage of electrophysical agents in physiotherapy practices from 1990 to 2010: A review
This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Maney PublishingBackground: The use of electrophysical agents has a historically important role in physiotherapy practice. There are anecdotal reports that the availability and usage of electrotherapy modalities are declining, which may have implications for physiotherapy practice. The aim of this literature review was to provide scientific evidence on electrotherapy usage in the last 20 years by identifying trends in availability, use, and non-use of nine electrotherapeutic modalities in physiotherapy practices during 1990s and 2000s. Methods: Review of empirical studies published in the English language from 1990 to 2010 and identified through searching online bibliographic databases, which included: Medline/OvidSP, PubMed Central, CINAHL/EBSCOhost, ScienceDirect, Scopus, ISI Web of Science, and Google Scholar. Findings: In the last 20 years, ultrasound availability and usage show increasing trends in several countries. The availability and use of pulsed shortwave diathermy and laser have shown steady trends. Transcutaneous electrical nerve stimulation, interferential, and biofeedback availability and usage have shown increasing trends in the UK and decreasing trends in Australia and the Republic of Ireland. Trends of continuous shortwave diathermy availability and use are declining irrespective of the country of the study. The availability and usage of microwave diathermy and H-wave show steeply declining trends, while there is a sharp rise in their non-availability over the last several years. Conclusions: The availability and use of electrophysical agents have greatly changed in the last 20 years. Declining trends in the availability and usage along with increasing trend of non-availability of electrotherapy modalities may have implications for electrotherapy education, training, and practice in the coming years.This study was funded by Health & Safety Executive, UK (grant no. 4371/R47.022)
MICRO-Foundations in Strategic Management: Squaring Coleman's Diagram
Abell, Felin and Foss argue that "macro-explanations" in strategic management, explanations in which organizational routines figure prominently and in which both the explanandum and explanans are at the macro-level, are necessarily incomplete. They take a diagram (which has the form of a trapezoid) from Coleman, Foundations of Social Theory, The Belknap Press of Harvard University Press, Cambridge (Mass.)/London, (1990) to task to show that causal chains connecting two macro-phenomena always involve "macro-to-micro" and "micro-to-macro" links, links that macro-explanations allegedly fail to recognize. Their plea for micro-foundations in strategic management is meant to shed light on these "missing links". The paper argues that while there are good reasons for providing micro-foundations, Abell, Felin and Foss's causal incompleteness argument is not one of them. Their argument does not sufficiently distinguish between causal and constitutive relations. Once these relations are carefully distinguished, it follows that Coleman's diagram has to be squared. This in turn allows us to see that macro-explanations need not be incomplete
Honey bee foraging distance depends on month and forage type
To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other
A scalar field instability of rotating and charged black holes in (4+1)-dimensional Anti-de Sitter space-time
We study the stability of static as well as of rotating and charged black
holes in (4+1)-dimensional Anti-de Sitter space-time which possess spherical
horizon topology. We observe a non-linear instability related to the
condensation of a charged, tachyonic scalar field and construct "hairy" black
hole solutions of the full system of coupled Einstein, Maxwell and scalar field
equations. We observe that the limiting solution for small horizon radius is
either a hairy soliton solution or a singular solution that is not a regular
extremal solution. Within the context of the gauge/gravity duality the
condensation of the scalar field describes a holographic
conductor/superconductor phase transition on the surface of a sphere.Comment: 16 pages including 8 figures, v2: discussion on soliton solutions
extended; v3: matches version accepted for publication in JHE
Thermodynamics, Disequilibrium, Evolution: Far-From-Equilibrium Geological and Chemical Considerations for Origin-Of-Life Research.
The influence of the frequency of periodic disturbances on the maintenance of phytoplankton diversity
The influence of periodic disturbances of various frequency on the maintenance of the phytoplankton diversity was studied by semicontinuous competition experiments. Disturbances consisted of dilution events, which meant both addition of fresh nutrients and elimination of organisms. The intervals between dilution events varied from 1 to 14 days. Diversity was found to increase with increasing intervals between disturbances. coexisting species belonged to different strategy types: (a) species with rapid growth under enriched conditions, (b) species with good competitive abilities under impoverished conditions, (c) species with the ability to build up storage pools of the limiting nutrient. An increase of the number of coexisting species over the number that would have coexisted in steady state was only found when the interval exceeded one generation time
The RN/CFT Correspondence Revisited
We reconsidered the quantum gravity description of the near horizon extremal
Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS/CFT
correspondence. We found that, for pure electric case, the right moving central
charge of dual 1D CFT is which is different from the previous result of left moving sector obtained by warped AdS/CFT description. We
discussed the discrepancy in these two approaches and examined novel properties
of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
Thermodynamics of a class of non-asymptotically flat black holes in Einstein-Maxwell-Dilaton theory
We analyse in detail the thermodynamics in the canonical and grand canonical
ensembles of a class of non-asymptotically flat black holes of the
Einstein-(anti) Maxwell-(anti) Dilaton theory in 4D with spherical symmetry. We
present the first law of thermodynamics, the thermodynamic analysis of the
system through the geometrothermodynamics methods, Weinhold, Ruppeiner,
Liu-Lu-Luo-Shao and the most common, that made by the specific heat. The
geometric methods show a curvature scalar identically zero, which is
incompatible with the results of the analysis made by the non null specific
heat, which shows that the system is thermodynamically interacting, does not
possess extreme case nor phase transition. We also analyse the local and global
stability of the thermodynamic system, and obtain a local and global stability
for the normal case for 0<\gamma<1 and for other values of \gamma, an unstable
system. The solution where \gamma=0 separates the class of locally and globally
stable solutions from the unstable ones.Comment: 18 pages, version accepted for publication in General Relativity and
Gravitatio
The Cosmic Infrared Background: Measurements and Implications
The cosmic infrared background records much of the radiant energy released by
processes of structure formation that have occurred since the decoupling of
matter and radiation following the Big Bang. In the past few years, data from
the Cosmic Background Explorer mission provided the first measurements of this
background, with additional constraints coming from studies of the attenuation
of TeV gamma-rays. At the same time there has been rapid progress in resolving
a significant fraction of this background with the deep galaxy counts at
infrared wavelengths from the Infrared Space Observatory instruments and at
submillimeter wavelengths from the Submillimeter Common User Bolometer Array
instrument. This article reviews the measurements of the infrared background
and sources contributing to it, and discusses the implications for past and
present cosmic processes.Comment: 61 pages, incl. 9 figures, to be published in Annual Reviews of
Astronomy and Astrophysics, 2001, Vol. 3
Helical Chirality: a Link between Local Interactions and Global Topology in DNA
DNA supercoiling plays a major role in many cellular functions. The global DNA conformation is however intimately linked to local DNA-DNA interactions influencing both the physical properties and the biological functions of the supercoiled molecule. Juxtaposition of DNA double helices in ubiquitous crossover arrangements participates in multiple functions such as recombination, gene regulation and DNA packaging. However, little is currently known about how the structure and stability of direct DNA-DNA interactions influence the topological state of DNA. Here, a crystallographic analysis shows that due to the intrinsic helical chirality of DNA, crossovers of opposite handedness exhibit markedly different geometries. While right-handed crossovers are self-fitted by sequence-specific groove-backbone interaction and bridging Mg2+ sites, left-handed crossovers are juxtaposed by groove-groove interaction. Our previous calculations have shown that the different geometries result in differential stabilisation in solution, in the presence of divalent cations. The present study reveals that the various topological states of the cell are associated with different inter-segmental interactions. While the unstable left-handed crossovers are exclusively formed in negatively supercoiled DNA, stable right-handed crossovers constitute the local signature of an unusual topological state in the cell, such as the positively supercoiled or relaxed DNA. These findings not only provide a simple mechanism for locally sensing the DNA topology but also lead to the prediction that, due to their different tertiary intra-molecular interactions, supercoiled molecules of opposite signs must display markedly different physical properties. Sticky inter-segmental interactions in positively supercoiled or relaxed DNA are expected to greatly slow down the slithering dynamics of DNA. We therefore suggest that the intrinsic helical chirality of DNA may have oriented the early evolutionary choices for DNA topology
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