Body mass index and risk of non-alcoholic fatty liver disease: two electronic health record prospective studies

Context: The relationship between rising body mass index (BMI) and prospective risk of non-alcoholic fatty liver disease (NAFLD) / non-alcoholic steatohepatitis (NASH) is virtually absent. Objective: Determine the extent of the association between BMI and risk of future NAFLD diagnosis, stratifying by sex and diabetes. Design: Two prospective studies using Humedica and THIN with 1.54 and 4.96 years of follow-up respectively. Setting: Electronic health record databases Participants: Patients with had a recorded BMI measurement between 15–60kg/m2, and smoking status, and one year of active status prior to baseline BMI. Patients with a diagnosis or history of chronic diseases were excluded. Interventions: None Main Outcome Measure: Recorded diagnosis of NAFLD/NASH during follow-up (Humedica ICD-9 code 571.8, and read codes for NAFLD and NASH in THIN). Results: Hazard ratios (HR) were calculated across BMI categories using BMI of 20–22.5kg/m2 as the reference category, adjusting for age, sex and smoking status. Risk of recorded NAFLD/NASH increased linearly with BMI and was approximately 5-fold higher in Humedica (HR=4.78, 95% CI 4.17–5.47) and 9-fold higher in THIN (HR=8.93, 7.11–11.23) at a BMI of 30–32.5 kg/m2 rising to around 10-fold higher in Humedica (HR=9.80, 8.49–11.32) and 14-fold higher in THIN (HR=14.32, 11.04–18.57) in the 37.5–40 kg/m2 BMI category. Risk of NAFLD/NASH was approximately 50% higher in men, and approximately double in those with diabetes. Conclusions: These data quantify the consistent and strong relationships between BMI and prospectively recorded diagnoses of NAFLD/NASH and emphasize the importance of weight reduction strategies for prevention and management of NAFLD

Coherent transport in linear arrays of quantum dots: the effects of period doubling and of quasi-periodicity

We evaluate the phase-coherent transport of electrons along linear structures of varying length, which are made from two types of potential wells set in either a periodic or a Fibonacci quasi-periodic sequence. The array is described by a tight-binding Hamiltonian and is reduced to an effective dimer by means of a decimation-renormalization method, extended to allow for connection to external metallic leads, and the transmission coefficient is evaluated in a T-matrix scattering approach. Parallel behaviors are found for the energy dependence of the density of electron states and of the transmittivity of the array. In particular, we explicitly show that on increasing its length the periodic array undergoes a metal-insulator transition near single occupancy per dot, whereas prominent pseudo-gaps emerge away from the band center in the Fibonacci-ordered array.Comment: 11 pages, 7 figure

Casimir Effect, Achucarro-Ortiz Black Hole and the Cosmological Constant

We treat the two-dimensional Achucarro-Ortiz black hole (also known as (1+1) dilatonic black hole) as a Casimir-type system. The stress tensor of a massless scalar field satisfying Dirichlet boundary conditions on two one-dimensional "walls" ("Dirichlet walls") is explicitly calculated in three different vacua. Without employing known regularization techniques, the expression in each vacuum for the stress tensor is reached by using the Wald's axioms. Finally, within this asymptotically non-flat gravitational background, it is shown that the equilibrium of the configurations, obtained by setting Casimir force to zero, is controlled by the cosmological constant.Comment: 20 pages, LaTeX, minor corrections, comments and clarifications added, version to appear in Phys. Rev.

Chiral 4d string vacua with D-branes and NSNS and RR fluxes

We discuss type IIB orientifolds with D-branes, and NSNS and RR field strength fluxes. The D-brane sectors lead to open string spectra with non-abelian gauge symmetry and charged chiral fermions. The closed string field strengths generate a scalar potential stabilizing most moduli. We describe the construction of N=1 supersymmetric models in the context of orientifolds of IIB theory on T^6/Z_2 x Z_2, containing D9-branes with world-volume magnetic fluxes, and illustrate model building possibilities with several explicit examples. We comment on a T-dual picture with D8-branes on non-Calabi-Yau half-flat geometries, and discuss some of the topological properties of such configurations. We also explore the construction of models with fluxes and with D3-branes at singularities and present a non-supersymmetric 3-family SU(5) model.Comment: latex, 49 pages, 2 figure

Flux Compactifications on Calabi-Yau Threefolds

The presence of RR and NS three-form fluxes in type IIB string compactification on a Calabi-Yau orientifold gives rise to a nontrivial superpotential W for the dilaton and complex structure moduli. This superpotential is computable in terms of the period integrals of the Calabi-Yau manifold. In this paper, we present explicit examples of both supersymmetric and nonsupersymmetric solutions to the resulting 4d N=1 supersymmetric no-scale supergravity, including some nonsupersymmetric solutions with relatively small values of W. Our examples arise on orientifolds of the hypersurfaces in $WP^{4}_{1,1,1,1,4}$ and $WP^{4}_{1,1,2,2,6}$. They serve as explicit illustrations of several of the ingredients which have played a role in the recent proposals for constructing de Sitter vacua of string theory.Comment: 30 pages, harvmac big; refs and minor comments adde

Electromigration of Single-Layer Clusters

Single-layer atom or vacancy clusters in the presence of electromigration are studied theoretically assuming an isotropic medium. A variety of distinctive behaviors distinguish the response in the three standard limiting cases of periphery diffusion (PD), terrace diffusion (TD), and evaporation-condensation (EC). A general model provides power laws describing the size dependence of the drift velocity in these limits, consistent with established results in the case of PD. The validity of the widely used quasistatic limit is calculated. Atom and vacancy clusters drift in opposite directions in the PD limit but in the same direction otherwise. In absence of PD, linear stability analysis reveals a new type of morphological instability, not leading to island break-down. For strong electromigration, Monte Carlo simulations show that clusters then destabilize into slits, in contrast to splitting in the PD limit. Electromigration affects the diffusion coefficient of the cluster and morphological fluctuations, the latter diverging at the instability threshold. An instrinsic attachment-detachment bias displays the same scaling signature as PD in the drift velocity.Comment: 11 pages, 4 figure

Low Energy Supersymmetry from Non-Geometry

We study a class of flux compactifications that have all the moduli stabilised, a high (GUT) string scale and a low (TeV) gravitino mass that is generated dynamically. These non-geometric compactifications correspond to type II string theories on SU(3)xSU(3) structure orientifolds. The resulting superpotentials admit, excluding non-perturbative effects, supersymmetric Minkowski vacua with any number of moduli stabilised. We argue that non-perturbative effects are present and introduce terms in the superpotential that are exponentially suppressed by the same moduli that appear perturbatively. These deform the supersymmetric Minkowski vacua to supersymmetric AdS vacua with an exponentially small gravitino mass. The resulting vacua allow for low scale supersymmetry breaking which can be realised by a number of mechanisms.Comment: 36pp; v2 references added, minor clarifications, JHEP versio

An Inflationary Scenario in Intersecting Brane Models

We propose a new scenario for D-term inflation which appears quite straightforwardly in the open string sector of intersecting brane models. We take the inflaton to be a chiral field in a bifundamental representation of the hidden sector and we argue that a sufficiently flat potential can be brane engineered. This type of model generically predicts a near gaussian red spectrum with negligible tensor modes. We note that this model can very naturally generate a baryon asymmetry at the end of inflation via the recently proposed hidden sector baryogenesis mechanism. We also discuss the possibility that Majorana masses for the neutrinos can be simultaneously generated by the tachyon condensation which ends inflation. Our proposed scenario is viable for both high and low scale supersymmetry breaking.Comment: 30 pages, 2 figures; v2 references and comments adde

Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r2>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (pinteraction= 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Concl

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a