Lorentz Covariance and the Dimensional Crossover of 2d-Antiferromagnets

We derive a lattice $\beta$-function for the 2d-Antiferromagnetic Heisenberg model, which allows the lattice interaction couplings of the nonperturbative Quantum Monte Carlo vacuum to be related directly to the zero-temperature fixed points of the nonlinear sigma model in the presence of strong interplanar and spin anisotropies. In addition to the usual renormalization of the gapful disordered state in the vicinity of the quantum critical point, we show that this leads to a chiral doubling of the spectra of excited states

The social geography of childcare: 'making up' the middle class child

Childcare is a condensate of disparate social forces and social processes. It is gendered and classed. It is subject to an excess of policy and political discourse. It is increasingly a focus for commercial exploitation. This is a paper reporting on work in progress in an ESRC funded research project (R000239232) on the choice and provision of pre-school childcare by middle class (service class) families in two contrasting London locations. Drawing on recent work in class analysis the paper examines the relationships between childcare choice, middle class fractions and locality. It suggests that on the evidence of the findings to date, there is some evidence of systematic differences between fractions in terms of values, perspectives and preferences for childcare, but a more powerful case for intra-class similarities, particularly when it comes to putting preferences into practice in the 'making up of a middle class child' through care and education

Functional morphology of the masticatory apparatus of two dicynodonts (Reptilia, Therapsida)

The specialized masticatory apparatus of Permo-Triassic dicynodonts (herbivorous mammal-like reptiles) is described and its function analysed by comparison of an archaic dicynodont, the pristerodont Emydops, with the advanced dicynodont Lystrosaurus. A unique feature of the dicynodont masticatory apparatus was the fact that the jaw joint consisted of two convex articulating surfaces which permitted free anteroposterior movement. Food was broken up during retraction—protraction serving merely to move the jaw forward for another retractive stroke. True propalinal action did not occur. Food was comminuted by shearing; grinding or crushing was not an integral part of the masticatory cycle. In Emydops, cutting took place at the beak when the jaw was elevated by the vertical component of force of the external adductor muscles. Slightly later in the masticatory cycle, cutting took place at the dentary teeth as the jaw was retracted by the stronger horizontal component of force from the same muscles. The two cutting areas and the motions by which they were utilized are distinct. In Lystrosaurus dentary teeth are lacking and the cutting area at the front of the jaws is expanded. Motion of the lower beak consisted of a combination of elevation and retraction by the powerful horizontal component of the muscles. During much of the Upper Permian and Lower Triassic, when dicynodonts were the dominant tetrapod herbivores, their peculiar masticatory apparatus enabled them to invade an environment apparently barred to conventional herbivores. The line leading to Lystrosaurus probably originated from an Emydops-like form, the main trend of evolution being toward increasingly effective utilization of the horizontal component of force exerted by the external adductors. However, the pristerodonts persisted with little change during most of the interval in which this evolution took place. It appears that the archaic jaw mechanism of pristerodonts was adapted in some way to a persistent environment which was different from the environment that favored the Lystrosaurus type of specialization

Do hip precautions after posterior-approach total hip arthroplasty affect dislocation rates? A systematic review of 7 studies with 6,900 patients

Background and purpose — Hip precautions limiting flexion, adduction, and internal rotation have been prescribed traditionally to minimize dislocation rates following THA. We assessed the prevalence of hip dislocation following posterior approach total hip arthroplasty without postoperative hip precautions. Methods — A systematic review of multiple medical databases was performed using the PRISMA guidelines and checklist. All clinical outcome studies that reported dislocation rates and postoperative instructions following posterior approach, primary surgery, published within the last 6 years, were included. Results — 6,900 patients were included from 7 Level I–IV studies, with 3,517 treated with and 3,383 without precautions. There was no statistically significant difference in the rates of dislocation between groups (2.2% in restricted group vs. 2.0% in unrestricted group). All but 1 study demonstrated no statistically significant differences in patient-reported outcome scores between restricted and unrestricted groups, including those pertaining to return to function, confidence, and pain. Interpretation — The review found no impact on dislocation rates following total hip arthroplasty performed through a posterior approach, regardless of the use of hip precautions. We also found no impact of the prescription of hip precautions on patient-reported outcome scores

An isotope dilution model for partitioning of phenylalanine and tyrosine uptake by the liver of lactating dairy cows

An isotope dilution model to describe the partitioning of phenylalanine (PHE) and tyrosine (TYR) in the bovine liver was developed. The model comprises four intracellular and six extracellular pools and various flows connecting these pools and external blood. Conservation of mass principles were applied to generate the fundamental equations describing the behaviour of the system in the steady state. The model was applied to datasets from multi-catheterised dairy cattle during a constant infusion of [1-13C] phenylalanine and [2,3,5,6-2H] tyrosine tracers. Model solutions described the extraction of PHE and TYR from the liver via the portal vein and hepatic artery. In addition, the exchange of free PHE and TYR between extracellular and intracellular pools was explained and the hydroxylation of PHE to TYR was estimated. The model was effective in providing information about the fates of PHE and TYR in the liver and could be used as part of a more complex system describing amino acid metabolism in the whole animal

Mobile learning for delivering health professional education (protocol)

© 2015 The Cochrane Collaboration.This is the protocol for a review and there is no abstract. The objectives are as follows: The objective of this review is to evaluate the effectiveness of mLearning educational interventions for delivering pre-registration and post-registration healthcare professional education. We will primarily assess the impact of these interventions on students knowledge, skills, professional attitudes and satisfaction

The transcription factor Gli3 promotes B cell development in fetal liver through repression of Shh

Before birth, B cells develop in the fetal liver (FL). In this study, we show that Gli3 activity in the FL stroma is required for B cell development. In the Gli3-deficient FL, B cell development was reduced at multiple stages, whereas the Sonic hedgehog (Hh [Shh])–deficient FL showed increased B cell development, and Gli3 functioned to repress Shh transcription. Use of a transgenic Hh-reporter mouse showed that Shh signals directly to developing B cells and that Hh pathway activation was increased in developing B cells from Gli3-deficient FLs. RNA sequencing confirmed that Hh-mediated transcription is increased in B-lineage cells from Gli3-deficient FL and showed that these cells expressed reduced levels of B-lineage transcription factors and B cell receptor (BCR)/pre-BCR–signaling genes. Expression of the master regulators of B cell development Ebf1 and Pax5 was reduced in developing B cells from Gli3-deficient FL but increased in Shh-deficient FL, and in vitro Shh treatment or neutralization reduced or increased their expression, respectively