ABJ(M) Chiral Primary Three-Point Function at Two-loops

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.archiveprefix: arXiv primaryclass: hep-th reportnumber: QMUL-PH-14-10 slaccitation: %%CITATION = ARXIV:1404.1117;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: QMUL-PH-14-10 slaccitation: %%CITATION = ARXIV:1404.1117;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: QMUL-PH-14-10 slaccitation: %%CITATION = ARXIV:1404.1117;%%Article funded by SCOAP

Phase separation and suppression of critical dynamics at quantum transitions of itinerant magnets: MnSi and (Sr1−x_{1-x}Cax_{x})RuO3_{3}

Quantum phase transitions (QPTs) have been studied extensively in correlated electron systems. Characterization of magnetism at QPTs has, however, been limited by the volume-integrated feature of neutron and magnetization measurements and by pressure uncertainties in NMR studies using powderized specimens. Overcoming these limitations, we performed muon spin relaxation ($\mu$SR) measurements which have a unique sensitivity to volume fractions of magnetically ordered and paramagnetic regions, and studied QPTs from itinerant heli/ferro magnet to paramagnet in MnSi (single-crystal; varying pressure) and (Sr$_{1-x}$Ca$_{x}$)RuO$_{3}$ (ceramic specimens; varying $x$). Our results provide the first clear evidence that both cases are associated with spontaneous phase separation and suppression of dynamic critical behavior, revealed a slow but dynamic character of the ``partial order'' diffuse spin correlations in MnSi above the critical pressure, and, combined with other known results in heavy-fermion and cuprate systems, suggest a possibility that a majority of QPTs involve first-order transitions and/or phase separation.Comment: 11 pages, 4 figures, 21 authors, to appear in Nature Physic

Thinking dispositions for teaching : enabling and supporting resilience in context

Preparing pre-teachers for an increasingly challenging teaching profession is a complex work and requires teacher educators to engage in the careful design of both programmes and professional learning opportunities. This chapter explores how an explicit focus on thinking dispositions that enable effective teaching are developed in a Master of Teaching (Secondary) programme. This programme, delivered on-site at a secondary school, included carefully constructed teaching opportunities to support development of thinking dispositions. Ways of thinking and the impact they have on feelings, actions and beliefs will be examined along with how the implementation of our thinking dispositions framework supports the development of resilience in challenging teaching and learning contexts

Novel GLP-1 Fusion Chimera as Potent Long Acting GLP-1 Receptor Agonist

GLP-1 has a variety of anti-diabetic effects. However, native GLP-1 is not suitable for therapy of diabetes due to its short half-life (t1/2<2 min). To circumvent this, we developed a long-lasting GLP-1 receptor agonist by the fusion of GLP-1 with human IgG2 Fc (GLP-1/hIgG2). ELISA-based receptor binding assay demonstrated that GLP-1/hIgG2 had high binding affinity to the GLP-1R in INS-1 cells (Kd = 13.90±1.52 nM). Upon binding, GLP-1/hIgG2 was rapidly internalized by INS-1 cells in a dynamin-dependent manner. Insulin RIA showed that GLP-1/IgG2 dose-dependently stimulated insulin secretion from INS-1 cells. Pharmacokinetic studies in CD1 mice showed that with intraperitoneal injection (i.p.), the GLP-1/hIgG2 peaked at 30 minutes in circulation and maintained a plateau for >168 h. Intraperitoneal glucose tolerance test (IPGTT) in mice showed that GLP-1/hIgG2 significantly decreased glucose excursion. Furthermore, IPGTT performed on mice one week after a single drug-injection also displayed significantly reduced glucose excursion, indicating that GLP-1/hIgG2 fusion protein has long-lasting effects on the modulation of glucose homeostasis. GLP-1/hIgG2 was found to be effective in reducing the incidence of diabetes in multiple-low-dose streptozotocin-induced type 1 diabetes in mice. Together, the long-lasting bioactive GLP-1/hIgG2 retains native GLP-1 activities and thus may serve as a potent GLP-1 receptor agonist

Drugs developed to treat diabetes, liraglutide and lixisenatide, cross the blood brain barrier and enhance neurogenesis

<p>Abstract</p> <p>Background</p> <p>Type 2 diabetes is a risk factor for Alzheimer's disease (AD), most likely linked to an impairment of insulin signalling in the brain. Therefore, drugs that enhance insulin signalling may have therapeutic potential for AD. Liraglutide (Victoza) and exenatide (Byetta) are novel long-lasting analogues of the GLP-1 incretin hormone and are currently available to treat diabetes. They facilitate insulin signalling via the GLP-1 receptor (GLP-1R). Numerous <it>in vitro </it>and <it>in vivo </it>studies have shown that GLP-1 analogues have a range of neuroprotective properties. GLP-1Rs are expressed in the hippocampal area of the brain an important site of adult neurogenesis and maintenance of cognition and memory formation. Therefore, if GLP-1 analogues can cross the blood brain barrier, diffuse through the brain to reach the receptors and most importantly activate them, their neuroprotective effects may be realized.</p> <p>Results</p> <p>In the present study we profiled the GLP-1 receptor agonists liraglutide (Victoza) and lixisenatide (Lyxumia). We measured the kinetics of crossing the blood brain barrier (BBB), activation of the GLP-1R by measuring cAMP levels, and physiological effects in the brain on neuronal stem cell proliferation and neurogenesis. Both drugs were able to cross the BBB. Lixisenatide crossed the BBB at all doses tested (2.5, 25, or 250 nmol/kg bw ip.) when measured 30 min post-injection and at 2.5-25 nmol/kg bw ip. 3 h post-injection. Lixisenatide also enhanced neurogenesis in the brain. Liraglutide crossed the BBB at 25 and 250 nmol/kg ip. but no increase was detectable at 2.5 nmol/kg ip. 30 min post-injection, and at 250 nmol/kg ip. at 3 h post-injection. Liraglutide and lixisenatide enhanced cAMP levels in the brain, with lixisenatide being more effective.</p> <p>Conclusions</p> <p>Our results suggest that these novel incretin analogues cross the BBB and show physiological activity and neurogenesis in the brain, which may be of use as a treatment of neurodegenerative diseases.</p

Opinion formation in multiplex networks with general initial distributions

We study opinion dynamics over multiplex networks where agents interact with bounded confidence. Namely, two neighbouring individuals exchange opinions and compromise if their opinions do not differ by more than a given threshold. In literature, agents are generally assumed to have a homogeneous confidence bound. Here, we study analytically and numerically opinion evolution over structured networks characterised by multiple layers with respective confidence thresholds and general initial opinion distributions. Through rigorous probability analysis, we show analytically the critical thresholds at which a phase transition takes place in the long-term consensus behaviour, over multiplex networks with some regularity conditions. Our results reveal the quantitative relation between the critical threshold and initial distribution. Further, our numerical simulations illustrate the consensus behaviour of the agents in network topologies including lattices and, small-world and scale-free networks, as well as for structure-dependent convergence parameters accommodating node heterogeneity. We find that the critical thresholds for consensus tend to agree with the predicted upper bounds in Theorems 4 and 5 in this paper. Finally, our results indicate that multiplexity hinders consensus formation when the initial opinion configuration is within a bounded range and, provide insight into information diffusion and social dynamics in multiplex systems modeled by networks

Physics, Astrophysics and Cosmology with Gravitational Waves

Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version <http://www.livingreviews.org/lrr-2009-2

Postnatal Development of Numbers and Mean Sizes of Pancreatic Islets and Beta-Cells in Healthy Mice and GIPRdn Transgenic Diabetic Mice

The aim of this study was to examine postnatal islet and beta-cell expansion in healthy female control mice and its disturbances in diabetic GIPRdn transgenic mice, which exhibit an early reduction of beta-cell mass. Pancreata of female control and GIPRdn transgenic mice, aged 10, 45, 90 and 180 days were examined, using state-of-the-art quantitative-stereological methods. Total islet and beta-cell volumes, as well as their absolute numbers increased significantly until 90 days in control mice, and remained stable thereafter. The mean islet volumes of controls also increased slightly but significantly between 10 and 45 days of age, and then remained stable until 180 days. The total volume of isolated beta-cells, an indicator of islet neogenesis, and the number of proliferating (BrdU-positive) islet cells were highest in 10-day-old controls and declined significantly between 10 and 45 days. In GIPRdn transgenic mice, the numbers of islets and beta-cells were significantly reduced from 10 days of age onwards vs. controls, and no postnatal expansion of total islet and beta-cell volumes occurred due to a reduction in islet neogenesis whereas early islet-cell proliferation and apoptosis were unchanged as compared to control mice. Insulin secretion in response to pharmacological doses of GIP was preserved in GIPRdn transgenic mice, and serum insulin to pancreatic insulin content in response to GLP-1 and arginine was significantly higher in GIPRdn transgenic mice vs. controls. We could show that the increase in islet number is mainly responsible for expansion of islet and beta-cell mass in healthy control mice. GIPRdn transgenic mice show a disturbed expansion of the endocrine pancreas, due to perturbed islet neogenesis