Fractional quantum Hall effect in a quantum point contact at filling fraction 5/2

Recent theories suggest that the excitations of certain quantum Hall states may have exotic braiding statistics which could be used to build topological quantum gates. This has prompted an experimental push to study such states using confined geometries where the statistics can be tested. We study the transport properties of quantum point contacts (QPCs) fabricated on a GaAs/AlGaAs two dimensional electron gas that exhibits well-developed fractional quantum Hall effect, including at bulk filling fraction 5/2. We find that a plateau at effective QPC filling factor 5/2 is identifiable in point contacts with lithographic widths of 1.2 microns and 0.8 microns, but not 0.5 microns. We study the temperature and dc-current-bias dependence of the 5/2 plateau in the QPC, as well as neighboring fractional and integer plateaus in the QPC while keeping the bulk at filling factor 3. Transport near QPC filling factor 5/2 is consistent with a picture of chiral Luttinger liquid edge-states with inter-edge tunneling, suggesting that an incompressible state at 5/2 forms in this confined geometry

Dietary Protein Intake and Incidence of Type 2 Diabetes in Europe: The EPIC-INTERACT Case-Cohort Study

OBJECTIVEThe long-term association between dietary protein and type 2 diabetes incidence is uncertain. We aimed to investigate the association between total, animal, and plant protein intake and the incidence of type 2 diabetes.RESEARCH DESIGN AND METHODSThe prospective European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study consists of 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 individuals from eight European countries, with an average follow-up time of 12.0 years. Pooled country-specific hazard ratios (HRs) and 95% CI of prentice-weighted Cox regression analyses were used to estimate type 2 diabetes incidence according to protein intake.RESULTSAfter adjustment for important diabetes risk factors and dietary factors, the incidence of type 2 diabetes was higher in those with high intake of total protein (per 10 g: HR 1.06 [95% CI 1.02-1.09], Ptrend 30 kg/m(2) (per 10 g animal protein: 1.19 [1.09-1.32]), and nonsignificant in men. Plant protein intake was not associated with type 2 diabetes (per 10 g: 1.04 [0.93-1.16], Ptrend = 0.098).CONCLUSIONSHigh total and animal protein intake was associated with a modest elevated risk of type 2 diabetes in a large cohort of European adults. In view of the rapidly increasing prevalence of type 2 diabetes, limiting iso-energetic diets high in dietary proteins, particularly from animal sources, should be considered

A Differential Network Approach to Exploring Differences between Biological States: An Application to Prediabetes

Background: Variations in the pattern of molecular associations are observed during disease development. The comprehensive analysis of molecular association patterns and their changes in relation to different physiological conditions can yield insight into the biological basis of disease-specific phenotype variation. Methodology: Here, we introduce a formal statistical method for the differential analysis of molecular associations via network representation. We illustrate our approach with extensive data on lipoprotein subclasses measured by NMR spectroscopy in 4,406 individuals with normal fasting glucose, and 531 subjects with impaired fasting glucose (prediabetes). We estimate the pair-wise association between measures using shrinkage estimates of partial correlations and build the differential network based on this measure of association. We explore the topological properties of the inferred network to gain insight into important metabolic differences between individuals with normal fasting glucose and prediabetes. Conclusions/Significance: Differential networks provide new insights characterizing differences in biological states. Based on conventional statistical methods, few differences in concentration levels of lipoprotein subclasses were found between individuals with normal fasting glucose and individuals with prediabetes. By performing the differential analysis of networks, several characteristic changes in lipoprotein metabolism known to be related to diabetic dyslipidemias were identified. The results demonstrate the applicability of the new approach to identify key molecular changes inaccessible to standard approaches

Biomechanical spinal growth modulation and progressive adolescent scoliosis – a test of the 'vicious cycle' pathogenetic hypothesis: Summary of an electronic focus group debate of the IBSE

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE) introduced the electronic focus group (EFG) as a means of increasing debate on knowledge of important topics. This has been designated as an on-line Delphi discussion. The text for this debate was written by Dr Ian A Stokes. It evaluates the hypothesis that in progressive scoliosis vertebral body wedging during adolescent growth results from asymmetric muscular loading in a "vicious cycle" (vicious cycle hypothesis of pathogenesis) by affecting vertebral body growth plates (endplate physes). A frontal plane mathematical simulation tested whether the calculated loading asymmetry created by muscles in a scoliotic spine could explain the observed rate of scoliosis increase by measuring the vertebral growth modulation by altered compression. The model deals only with vertebral (not disc) wedging. It assumes that a pre-existing scoliosis curve initiates the mechanically-modulated alteration of vertebral body growth that in turn causes worsening of the scoliosis, while everything else is anatomically and physiologically 'normal' The results provide quantitative data consistent with the vicious cycle hypothesis. Dr Stokes' biomechanical research engenders controversy. A new speculative concept is proposed of vertebral symphyseal dysplasia with implications for Dr Stokes' research and the etiology of AIS. What is not controversial is the need to test this hypothesis using additional factors in his current model and in three-dimensional quantitative models that incorporate intervertebral discs and simulate thoracic as well as lumbar scoliosis. The growth modulation process in the vertebral body can be viewed as one type of the biologic phenomenon of mechanotransduction. In certain connective tissues this involves the effects of mechanical strain on chondrocytic metabolism a possible target for novel therapeutic intervention

Prenatal exposure to antipsychotic medication and use of primary health care system in childhood: a population-based cohort study in Denmark

Anne Mette Lund Würtz,1,2 Claus Høstrup Vestergaard,1 Dorte Rytter,2 Merete Juul Sørensen,3 Jakob Christensen,4 Mogens Vestergaard,1,5 Bodil Hammer Bech1,2 1Research Unit for General Practice, 2Section for Epidemiology, Department of Public Health, Aarhus University, 3Regional Centre for Child and Adolescent Psychiatry, 4Department of Neurology, Aarhus University Hospital, 5Section for General Practice, Department of Public Health, Aarhus University, Aarhus, Denmark Background: Antipsychotic (AP) medication is increasingly used for many health conditions. Prenatal exposure to AP medication has been associated with several adverse outcomes, but the findings remain inconsistent.Purpose: We aimed to investigate prenatal exposure to AP medication and the use of primary health care system in childhood.Subjects and methods: All live-born singletons in Denmark during 1997–2012 were identified in the nationwide Danish National Patient Register and followed until December 31, 2013 (n = 963,010). Information on prenatal exposure to AP medication was obtained from the Danish Register of Medicinal Product Statistics. Contacts to the general practitioner (GP) were used as a proxy for the overall health of the children. Negative binomial regression was used to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for the association between prenatal exposure to AP medication and number and type of GP contacts, excluding routine well-child visits and vaccinations. The models were adjusted for sex and birth date of the child, maternal age, parity, cohabitation status, income, education, smoking status, diagnosis of substance abuse, severe psychiatric disorder, depression and epilepsy as well as the use of antiepileptic drugs, antidepressants, benzodiazepines and insulin.Results: The prenatally AP-exposed children had 7% more GP contacts than unexposed children, IRR: 1.07 (95% CI: 1.03, 1.11). The association was slightly stronger among children of mothers with no diagnosis of severe psychiatric disorder (IRR: 1.08, 95% CI: 1.04–1.13) than among children of mothers with severe psychiatric disorder (IRR: 1.03, 95% CI: 0.96–1.11), but the difference was not statistically significant. We found no difference between prenatally AP-exposed children and their unexposed siblings, IRR: 1.00 (95% CI: 0.97–1.04) for total contacts.Conclusion: Children of women using AP medication in pregnancy had more GP contacts in childhood than children of mothers not using AP medication. However, this might be explained by confounding from maternal behavior and mental illness. Keywords: antipsychotic medication, prenatal drug exposure, primary health care, general practitioner&nbsp

The Smart Table Constraint

Table Constraints are very useful for modeling combinatorial problems in Constraint Programming (CP). They are a universal mechanism for representing constraints, but unfortunately the size of their tables can grow exponentially with their arities. In this paper, we propose to authorize entries in tables to contain simple arithmetic constraints, replacing classical tuples of values by so-called smart tuples. Smart table constraints can thus be viewed as logical combinations of those simple arithmetic constraints. This new form of tuples allows us to encode compactly many constraints, including a dozen of well-known global constraints. We show that, under a very reasonable assumption about the acyclicity of smart tuples, a Generalized Arc Consistency algorithm of low time complexity can be devised. Our experimental results demonstrate that the smart table constraint is a highly promising general purpose tool for CP