6,504 research outputs found
Refeeding Hypophosphatemia in Adolescents With Anorexia Nervosa: A Systematic Review
The rate of adolescents presenting with anorexia nervosa (AN) is increasing. Medically unstable adolescents are admitted to the hospital for nutrition restoration. A lack of global consensus on appropriate refeeding practices of malnourished patients has resulted in inconsistent refeeding practices. Refeeding hypophosphatemia (RH) is the most common complication associated with refeeding the malnourished patient. This review sought to identify the range of refeeding rates adopted globally and the implication that total energy intake and malnutrition may have on RH while refeeding adolescents with anorexia nervosa. Studies were identified by a systematic electronic search of medical databases from 1980 to September 2012. Seventeen publications were identified, including 6 chart reviews, 1 observational study, and 10 case reports, with a total of 1039 subjects. The average refeeding energy intake was 1186 kcal/d, ranging from 125–1900 kcal/d, with a mean percentage median body mass index (% mBMI) of 78%. The average incidence rate of RH was 14%. A significant correlation between malnutrition (% mBMI) and post-refeeding phosphate was identified (R 2 = 0.6, P = .01). This review highlights the disparity in refeeding rates adopted internationally in treating malnourished adolescents with anorexia nervosa. Based on this review, the severity of malnutrition seems to be a marker for the development of RH more so than total energy intake
Randomize-Then-Optimize for Sampling and Uncertainty Quantification in Electrical Impedance Tomography
A field expansions method for scattering by periodic multilayered media
The interaction of acoustic and electromagnetic waves with periodic structures plays an important role in a wide range of problems of scientific and technological interest. This contribution focuses upon the robust and high-order numerical simulation of a model for the interaction of pressure waves generated within the earth incident upon layers of sediment near the surface. Herein described is a boundary perturbation method for the numerical simulation of scattering returns from irregularly shaped periodic layered media. The method requires only the discretization of the layer interfaces (so that the number of unknowns is an order of magnitude smaller than finite difference and finite element simulations), while it avoids not only the need for specialized quadrature rules but also the dense linear systems characteristic of boundary integral/element methods. The approach is a generalization to multiple layers of Bruno and Reitich’s “Method of Field Expansions” for dielectric structures with two layers. By simply considering the entire structure simultaneously, rather than solving in individual layers separately, the full field can be recovered in time proportional to the number of interfaces. As with the original field expansions method, this approach is extremely efficient and spectrally accurate
Community Libraries in England: Empowering Volunteers and a catalyst for change
This paper explores the balance between austerity localism (a reaction to public budget cuts) and progressive localism (a challenge to neo-liberalist hegemony) in the transfer of libraries to volunteer management. It is based on interviews in libraries in a northern city. Libraries in the U.K. are vulnerable to budget cuts as the extent of statutory provision is ambiguous and transfer to volunteer management may be the only viable alternative to closure. Volunteers felt compelled to act to save their libraries from closure, but in doing so were developing new services and ways of providing them. This showed a nuanced balance between a reaction to austerity and an approach which could be regarded as ‘progressive’. The paper contributes to the meaning and use of the concept of ‘progressive localism’, and understanding the synergy between this and ‘austerity localism’ within the asset transfer of library services
Developmental Contexts and Features of Elite Academy Footoall Players: Coach and Player Perspectives
Player profiling can reap many benefits; through reflective coach-athlete dialogue that produces a profile the athlete has a raised awareness of their own development, while the coach has an opportunity to understand the athlete's viewpoint. In this study, we explored how coaches and players perceived the development features of an elite academy footballer and the contexts in which these features are revealed, in order to develop a player profile to be used for mentoring players. Using a Delphi polling technique, coaches and players experienced a number of ‘rounds’ of expressing their opinions regarding player development contexts and features, ultimately reduced into a consensus. Players and coaches had differing priorities on the key contexts of player development. These contexts, when they reflect the consensus between players and coaches were heavily dominated by ability within the game and training. Personal, social, school, and lifestyle contexts featured less prominently. Although ‘discipline’ was frequently mentioned as an important player development feature, coaches and players disagreed on the importance of ‘training’
Diffusion-controlled generation of a proton-motive force across a biomembrane
Respiration in bacteria involves a sequence of energetically-coupled electron
and proton transfers creating an electrochemical gradient of protons (a
proton-motive force) across the inner bacterial membrane. With a simple kinetic
model we analyze a redox loop mechanism of proton-motive force generation
mediated by a molecular shuttle diffusing inside the membrane. This model,
which includes six electron-binding and two proton-binding sites, reflects the
main features of nitrate respiration in E. coli bacteria. We describe the time
evolution of the proton translocation process. We find that the electron-proton
electrostatic coupling on the shuttle plays a significant role in the process
of energy conversion between electron and proton components. We determine the
conditions where the redox loop mechanism is able to translocate protons
against the transmembrane voltage gradient above 200 mV with a thermodynamic
efficiency of about 37%, in the physiologically important range of temperatures
from 250 to 350 K.Comment: 26 pages, 4 figures. A similar model is used in arXiv:0806.3233 for a
different biological system. Minor changes in the Acknowledgements sectio
Dobrushin-Kotecky-Shlosman theorem for polygonal Markov fields in the plane
We consider the so-called length-interacting Arak-Surgailis polygonal Markov
fields with V-shaped nodes - a continuum and isometry invariant process in the
plane sharing a number of properties with the two-dimensional Ising model. For
these polygonal fields we establish a low-temperature phase separation theorem
in the spirit of the Dobrushin-Kotecky-Shlosman theory, with the corresponding
Wulff shape deteremined to be a disk due to the rotation invariant nature of
the considered model. As an important tool replacing the classical cluster
expansion techniques and very well suited for our geometric setting we use a
graphical construction built on contour birth and death process, following the
ideas of Fernandez, Ferrari and Garcia.Comment: 59 pages, new version revised according to the referee's suggestions
and now publishe
Structural properties of epitaxial {\alpha}-U thin films on Ti, Zr, W and Nb
Thin layers of orthorhombic uranium ({\alpha}-U) have been grown onto
buffered sapphire substrates by d.c. magnetron sputtering, resulting in the
discovery of new epitaxial matches to Ti(00.1) and Zr(00.1) surfaces. These
systems have been characterised by X-ray diffraction and reflectivity and the
optimal deposition temperatures have been determined. More advanced structural
characterisation of the known Nb(110) and W(110) buffered {\alpha}-U systems
has also been carried out, showing that past reports of the domain structures
of the U layers are incomplete. The ability of this low symmetry structure to
form crystalline matches across a range of crystallographic templates
highlights the complexity of U metal epitaxy and points naturally toward
studies of the low temperature electronic properties of {\alpha}-U as a
function of epitaxial strain
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