To PEG or not to PEG that is the question

Nutrition support involves the use of oral supplements, enteral tube feeding or parenteral nutrition. These interventions are considered when oral intake alone fails to meet nutritional requirements. Special diets and oral supplements are usually the first approach to managing malnutrition; however, their role becomes limited when oral intake is restricted or if swallowing is unsafe. Enteral tube feeding or parenteral nutrition are alternative means of providing nutrition support for this select group of patients. Percutaneous endoscopic gastrostomy (PEG) feeding was introduced into clinical practice in 1980. It describes a feeding tube placed directly into the stomach under endoscopic guidance. It is an established means of providing enteral nutrition to those who have functionally normal gastrointestinal tracts, but who cannot meet their nutritional requirements due to inadequate oral intake. The intervention is usually reserved when nutritional intake is likely to be inadequate for more than 4–6 weeks. Although the benefits of PEG have been shown for a select group of patients, there currently exists concerns about the increasing frequency of this intervention, and also uncertainty about the long-term benefits for certain patients. The 2004 UK National Confidential Enquiry into Patient Outcome and Death report emphasised this concern, with almost a fifth of PEG being undertaken for futile indications that negatively influenced morbidity and mortality. The present review paper discusses the indications for, controversies surrounding and complications of gastrostomy feeding and provides practical advice on optimising patient selection for this intervention

Dynamical equations for high-order structure functions, and a comparison of a mean field theory with experiments in three-dimensional turbulence

Two recent publications [V. Yakhot, Phys. Rev. E {\bf 63}, 026307, (2001) and R.J. Hill, J. Fluid Mech. {\bf 434}, 379, (2001)] derive, through two different approaches that have the Navier-Stokes equations as the common starting point, a set of steady-state dynamic equations for structure functions of arbitrary order in hydrodynamic turbulence. These equations are not closed. Yakhot proposed a "mean field theory" to close the equations for locally isotropic turbulence, and obtained scaling exponents of structure functions and an expression for the tails of the probability density function of transverse velocity increments. At high Reynolds numbers, we present some relevant experimental data on pressure and dissipation terms that are needed to provide closure, as well as on aspects predicted by the theory. Comparison between the theory and the data shows varying levels of agreement, and reveals gaps inherent to the implementation of the theory.Comment: 16 pages, 23 figure

The Impact of Name-Matching and Blocking on Author Disambiguation

In this work, we address the problem of blocking in the context of author name disambiguation. We describe a framework that formalizes different ways of name-matching to determine which names could potentially refer to the same author. We focus on name variations that follow from specifying a name with different completeness (i.e. full first name or only initial). We extend this framework by a simple way to define traditional, new and custom blocking schemes. Then, we evaluate different old and new schemes in the Web of Science. In this context we define and compare a new type of blocking schemes. Based on these results, we discuss the question whether name-matching can be used in blocking evaluation as a replacement of annotated author identifiers. Finally, we argue that blocking can have a strong impact on the application and evaluation of author disambiguation

Universal behaviour of entrainment due to coherent structures in turbulent shear flow

I suggest a solution to a persistent mystery in the physics of turbulent shear flows: cumulus clouds rise to towering heights, practically without entraining the ambient medium, while apparently similar turbulent jets in general lose their identity within a small distance through entrainment and mixing. From dynamical systems computations on a model chaotic vortical flow, I show that entrainment and mixing due to coherent structures depend sensitively on the relative speeds of different portions of the flow. A small change in these speeds, effected for example by heating, drastically alters the sizes of the KAM tori and the chaotic mixing region. The entrainment rate and, hence, the lifetime of a turbulent shear flow, shows a universal, non-monotone dependence on the heating.Comment: Preprint replaced in order to add the following comment: accepted for publication in Phys. Rev. Let

Lysosomal pH Is Regulated in a Sex Dependent Manner in Immune Cells Expressing CXorf21

Background:CXorf21 and SLC15a4 both contain risk alleles for systemic lupus erythematosus (SLE) and Sjögren's syndrome (pSS). The former escapes X inactivation. Our group predicts specific endolysosomal-dependent immune responses are driven by the protein products of these genes, which form a complex at the endolysosomal surface. Our previous studies have shown that knocking out CXorf21 increases lysosomal pH in female monocytes, and the present study assesses whether the lysosomal pH in 46,XX women, who overexpress CXorf21 in monocytes, B cells, and dendritic cells (DCs), differs from 46,XY men.Methods: To determine endolysosome compartment pH we used both LysoSensor™ Yellow/Blue DND-160 and pHrodo® Red AM Intracellular pH Indicator in primary monocyte, B cells, DCs, NK cells, and T cells from healthy men and women volunteers.Results: Compared to male samples, female monocytes, B cells, and DCs had lower endolysosomal pH (female/male pH value: monocytes 4.9/5.6 p < 0.0001; DCs 4.9/5.7 p = 0.044; B cells 5.0/5.6 p < 0.05). Interestingly, T cells and NK cells, which both express low levels of CXorf21, showed no differential pH levels between men and women.Conclusion: We have previously shown that subjects with two or more X-chromosomes have increased CXorf21 expression in specific primary immune cells. Moreover, knockdown of CXorf21 increases lysosomal pH in female monocytes. The present data show that female monocytes, DC, B cells, where CXorf21 is robustly expressed, have lower lysosomal pH compared to the same immune cell populations from males. The lower pH levels observed in specific female immune cells provide a function to these SLE/SS-associated genes and a mechanism for the reported inflated endolysosomal-dependent immune response observed in women compared to men (i.e., TLR7/type I Interferon activity)

Generation of Large-Scale Vorticity in a Homogeneous Turbulence with a Mean Velocity Shear

An effect of a mean velocity shear on a turbulence and on the effective force which is determined by the gradient of Reynolds stresses is studied. Generation of a mean vorticity in a homogeneous incompressible turbulent flow with an imposed mean velocity shear due to an excitation of a large-scale instability is found. The instability is caused by a combined effect of the large-scale shear motions (''skew-induced" deflection of equilibrium mean vorticity) and ''Reynolds stress-induced" generation of perturbations of mean vorticity. Spatial characteristics, such as the minimum size of the growing perturbations and the size of perturbations with the maximum growth rate, are determined. This instability and the dynamics of the mean vorticity are associated with the Prandtl's turbulent secondary flows. This instability is similar to the mean-field magnetic dynamo instability. Astrophysical applications of the obtained results are discussed.Comment: 8 pages, 3 figures, REVTEX4, submitted to Phys. Rev.

Fluid Particle Accelerations in Fully Developed Turbulence

The motion of fluid particles as they are pushed along erratic trajectories by fluctuating pressure gradients is fundamental to transport and mixing in turbulence. It is essential in cloud formation and atmospheric transport, processes in stirred chemical reactors and combustion systems, and in the industrial production of nanoparticles. The perspective of particle trajectories has been used successfully to describe mixing and transport in turbulence, but issues of fundamental importance remain unresolved. One such issue is the Heisenberg-Yaglom prediction of fluid particle accelerations, based on the 1941 scaling theory of Kolmogorov (K41). Here we report acceleration measurements using a detector adapted from high-energy physics to track particles in a laboratory water flow at Reynolds numbers up to 63,000. We find that universal K41 scaling of the acceleration variance is attained at high Reynolds numbers. Our data show strong intermittency---particles are observed with accelerations of up to 1,500 times the acceleration of gravity (40 times the root mean square value). Finally, we find that accelerations manifest the anisotropy of the large scale flow at all Reynolds numbers studied.Comment: 7 pages, 4 figure

Manipulation and reduction of paediatric fractures of the distal radius and forearm using intranasal diamorphine and 50% oxygen and nitrous oxide in the emergency department

A retrospective study was performed in 100 children aged between two and 16 years, with a dorsally angulated stable fracture of the distal radius or forearm, who were treated with manipulation in the emergency department (ED) using intranasal diamorphine and 50% oxygen and nitrous oxide. Pre- and post-manipulation radiographs, the final radiographs and the clinical notes were reviewed. A successful reduction was achieved in 90 fractures (90%) and only three children (3%) required remanipulation and Kirschner wire fixation or internal fixation. The use of Entonox and intranasal diamorphine is safe and effective for the closed reduction of a stable paediatric fracture of the distal radius and forearm in the ED. By facilitating discharge on the same day, there is a substantial cost benefit to families and the NHS and we recommend this method

Hyperviscosity, Galerkin truncation and bottlenecks in turbulence

It is shown that the use of a high power $\alpha$ of the Laplacian in the dissipative term of hydrodynamical equations leads asymptotically to truncated inviscid \textit{conservative} dynamics with a finite range of spatial Fourier modes. Those at large wavenumbers thermalize, whereas modes at small wavenumbers obey ordinary viscous dynamics [C. Cichowlas et al. Phys. Rev. Lett. 95, 264502 (2005)]. The energy bottleneck observed for finite $\alpha$ may be interpreted as incomplete thermalization. Artifacts arising from models with $\alpha > 1$ are discussed.Comment: 4 pages, 2 figures, Phys. Rev. Lett. in pres