Magnetospectroscopy of symmetric and anti-symmetric states in double quantum wells

The experimental results obtained for the magneto-transport in the InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of wells are reported. The beating-effect occurred in the Shubnikov-de Haas (SdH) oscillations was observed for both types of the structures at low temperatures in the parallel transport when magnetic field was perpendicular to the layers. An approach to the calculation of the Landau levels energies for DQW structures was developed and then applied to the analysis and interpretation of the experimental data related to the beating-effect. We also argue that in order to account for the observed magneto-transport phenomena (SdH and Integer Quantum Hall effect), one should introduce two different quasi-Fermi levels characterizing two electron sub-systems regarding symmetry properties of their states, symmetric and anti-symmetric ones which are not mixed by electron-electron interaction.Comment: 20 pages, 20 figure

Effect of Spatial Charge Inhomogeneity on 1/f Noise Behavior in Graphene

Scattering mechanisms in graphene are critical to understanding the limits of signal-to-noise-ratios of unsuspended graphene devices. Here we present the four-probe low frequency noise (1/f) characteristics in back-gated single layer graphene (SLG) and bilayer graphene (BLG) samples. Contrary to the expected noise increase with the resistance, the noise for SLG decreases near the Dirac point, possibly due to the effects of the spatial charge inhomogeneity. For BLG, a similar noise reduction near the Dirac point is observed, but with a different gate dependence of its noise behavior. Some possible reasons for the different noise behavior between SLG and BLG are discussed.Comment: 28 pages, 3 figures + 3 supplement figure

Genetic risk prediction of atrial fibrillation

Background—Atrial fibrillation (AF) has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke. Methods—To determine whether genetic data can stratify risk for development of AF, we examined associations between AF genetic risk scores and incident AF in five prospective studies comprising 18,919 individuals of European ancestry. We examined associations between AF genetic risk scores and ischemic stroke in a separate study of 509 ischemic stroke cases (202 cardioembolic [40%]) and 3,028 referents. Scores were based on 11 to 719 common variants (≥5%) associated with AF at P-values ranging from <1x10-3 to <1x10-8 in a prior independent genetic association study. Results—Incident AF occurred in 1,032 (5.5%) individuals. AF genetic risk scores were associated with new-onset AF after adjusting for clinical risk factors. The pooled hazard ratio for incident AF for the highest versus lowest quartile of genetic risk scores ranged from 1.28 (719 variants; 95%CI, 1.13-1.46; P=1.5x10-4) to 1.67 (25 variants; 95%CI, 1.47-1.90; P=9.3x10-15). Discrimination of combined clinical and genetic risk scores varied across studies and scores (maximum C statistic, 0.629-0.811; maximum ΔC statistic from clinical score alone, 0.009-0.017). AF genetic risk was associated with stroke in age- and sex-adjusted models. For example, individuals in the highest versus lowest quartile of a 127-variant score had a 2.49-fold increased odds of cardioembolic stroke (95%CI, 1.39-4.58; P=2.7x10-3). The effect persisted after excluding individuals (n=70) with known AF (odds ratio, 2.25; 95%CI, 1.20-4.40; P=0.01). Conclusions—Comprehensive AF genetic risk scores were associated with incident AF beyond associations for clinical AF risk factors, though offered small improvements in discrimination. AF genetic risk was also associated with cardioembolic stroke in age- and sex-adjusted analyses. Efforts are warranted to determine whether AF genetic risk may improve identification of subclinical AF or help distinguish between stroke mechanisms

SNP Variants in Major Histocompatibility Complex Are Associate with Sarcoidosis Susceptibility - A Joint Analysis in Four European Populations

Sarcoidosis is a multiorgan inflammatory disorder with heritability estimates up to 66%. Previous studies have shown the major histocompatibility complex (MHC) region to be associated with sarcoidosis, suggesting a functional role for antigen-presenting molecules and immune mediators in the disease pathogenesis. To detect variants predisposing to sarcoidosis and to identify genetic differences between patient subgroups, we studied four genes in the MHC Class III region (LTA, TNF, AGER, BTNL2) and HLA-DRA with tag-SNPs and their relation to HLA-DRB1 alleles. We present results from a joint analysis of four study populations (Finnish, Swedish, Dutch, and Czech). Patients with sarcoidosis (n = 805) were further subdivided based on the disease activity and the presence of Lofgren's syndrome. In a joint analysis, seven SNPs were associated with non-Lofgren sarcoidosis (NL; the strongest association with rs3177928, P = 1.79E-07, OR = 1.9) and eight with Lofgren's syndrome [ Lofgren syndrome (LS); the strongest association with rs3129843, P = 3.44E-12, OR = 3.4] when compared with healthy controls (n = 870). Five SNPs were associated with sarcoidosis disease course (the strongest association with rs3177928, P = 0.003, OR = 1.9). The high linkage disequilibrium (LD) between SNPs and an HLA-DRB1 challenged the result interpretation. When the SNPs and HLA-DRB1 alleles were analyzed together, independent association was observed for four SNPs in the HLA-DRA/BTNL2 region: rs3135365 (NL; P = 0.015), rs3177928 (NL; P <0.001), rs6937545 (LS; P = 0.012), and rs5007259 (disease activity; P = 0.002). These SNPs act as expression quantitative trait loci (eQTL) for HLA-DRB1 and/or HLA-DRB5. In conclusion, we found novel SNPs in BTNL2 and HLA-DRA regions associating with sarcoidosis. Our finding further establishes that polymorphisms in the HLA-DRA and BTNL2 have a role in sarcoidosis susceptibility. This multi-population study demonstrates that at least a part of these associations are HLA-DRB1 independent (e.g., not due to LD) and shared across ancestral origins. The variants that were independent of HLA-DRB1 associations acted as eQTL for HLA-DRB1 and/or -DRB5, suggesting a role in regulating gene expression.Peer reviewe

Academic Performance and Behavioral Patterns

Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

Models for compressive strength estimation through non-destructive testing of highly self-compacting concrete containing recycled concrete aggregate and slag-based binder

Indirect estimation of compressive strength through non-destructive testing is key to monitoring the strength of structural concretes used in construction and rehabilitation works. However, no models are available to perform this estimation in highly Self-Compacting Concrete (SCC) with Recycled Concrete Aggregate (RCA). To fill this gap, two indirect measures were tested in this paper, the hammer rebound index and Ultrasonic Pulse Velocity (UPV), to predict the compressive strength of highly SCC. To do so, 24 SCC mixes were developed with different aggregate powders, binders, such as Ground Granulated Blast Furnace Slag (GGBFS), and contents of fine RCA. Compressive strength, and both indirect measures of all mixtures were determined at 1, 7, 28, and 90 days. The development of specific models for highly SCC responded to the inappropriateness of conventional models that are not adapted to its high fines content. Modelling as a function of either UPV or the hammer rebound index yielded accurate predictions, although the UPV model proved more sensitive to compositional changes and presented higher uncertainty. The best predictions were modelled by combining both indirect measures. The models provided safe and accurate indirect estimations of the compressive strength of high flowability SCC in real structures.Spanish Ministry MCIU, AEI and ERDF [grant number FPU17/03374]; the Junta de Castilla y León (Regional Government) and ERDF [grant number UIC-231, BU119P17]; Youth Employment Initiative (JCyL) and ESF [grant number UBU05B_1274]; and, finally, the University of Burgos [grant number SUCONS, Y135.GI]

A roadmap for gene system development in Clostridium

Clostridium species are both heroes and villains. Some cause serious human and animal diseases, those present in the microbiota contribute to health and wellbeing, while others represent useful industrial chassis for the production of chemicals and fuels. To understand, counter or exploit, there is a fundamental requirement for effective systems that may be used for directed or random genome modifications. We have formulated a simple roadmap whereby the necessary gene systems maybe developed and deployed. At its heart is the use of 'pseudo-suicide' vectors and the creation of a pyrE mutant (a uracil auxotroph), initially aided by ClosTron technology, but ultimately made using a special form of allelic exchange termed ACE (Allele-Coupled Exchange). All mutants, regardless of the mutagen employed, are made in this host. This is because through the use of ACE vectors, mutants can be rapidly complemented concomitant with correction of the pyrE allele and restoration of uracil prototrophy. This avoids the phenotypic effects frequently observed with high copy number plasmids and dispenses with the need to add antibiotic to ensure plasmid retention. Once available, the pyrE host may be used to stably insert all manner of application specific modules. Examples include, a sigma factor to allow deployment of a mariner transposon, hydrolases involved in biomass deconstruction and therapeutic genes in cancer delivery vehicles. To date, provided DNA transfer is obtained, we have not encountered any clostridial species where this technology cannot be applied. These include, Clostridium difficile, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium botulinum, Clostridium perfringens, Clostridium sporogenes, Clostridium pasteurianum, Clostridium ljungdahlii, Clostridium autoethanogenum and even Geobacillus thermoglucosidasius

FGF-23: More Than a Regulator of Renal Phosphate Handling?

Fibroblast growth factor 23 (FGF-23) is likely to be the most important regulator of phosphate homeostasis, which mediates its functions through FGF receptors and the coreceptor Klotho. Besides reducing expression of the sodium-phosphate cotransporters NPT2a and NPT2c in the proximal tubules, FGF-23 inhibits the renal 1α-hydroxylase and stimulates the 24-hydroxylase, and it appears to reduce parathyroid hormone (PTH) secretion in short-term studies. FGF-23 synthesis and secretion by osteocytes and osteoblasts is upregulated through 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and through an increased dietary phosphate intake. FGF-23 levels are elevated or inappropriately normal in patients with tumor-induced osteomalacia and several inherited hypophosphatemic disorders, but the most significant increases are found in patients with chronic kidney disease (CKD). During the early stages of CKD, increased FGF-23 production enhances urinary phosphate excretion and thus prevents the development of hyperphosphatemia, reduces the circulating levels of 1,25(OH)2D3, and therefore contributes to the development of secondary hyperparathyroidism. In patients with end-stage renal disease (ESRD), FGF-23 levels can be extremely high and were shown to be predictors of bone mineralization, left ventricular hypertrophy, vascular calcification, and mortality. It remains to be determined, however, whether FGF-23 represents simply a sensitive biomarker of an abnormal phosphate homeostasis or has, independent of serum phosphate levels, potentially negative “off-target” effects. Nonetheless, reducing the production and/or the biologic activity of FGF-23 may be an important therapeutic goal for this patient population. © 2010 American Society for Bone and Mineral Research

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

Abstract 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 and rhinitis and (3) to develop guidelines with all stakeholders that could be used globally for all countries and populations. ARIA—disseminated and implemented in over 70 countries globally—is now focusing on the implementation of emerging technologies for individualized and predictive medicine. MASK [MACVIA (Contre les Maladies Chroniques pour un Vieillissement Actif)-ARIA Sentinel NetworK] uses mobile technology to develop care pathways for the management of rhinitis and asthma by a multi-disciplinary group and by patients themselves. An app (Android and iOS) is available in 20 countries and 15 languages. It uses a visual analogue scale to assess symptom control and work productivity as well as a clinical decision support system. It is associated with an inter-operable tablet for physicians and other health care professionals. The scaling up strategy uses the recommendations of the European Innovation Partnership on Active and Healthy Ageing. The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease

Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5)

Abstract Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) focuses on the integrated care of chronic diseases. Area 5 (Care Pathways) was initiated using chronic respiratory diseases as a model. The chronic respiratory disease action plan includes (1) AIRWAYS integrated care pathways (ICPs), (2) the joint initiative between the Reference site MACVIA-LR (Contre les MAladies Chroniques pour un VIeillissement Actif) and ARIA (Allergic Rhinitis and its Impact on Asthma), (3) Commitments for Action to the European Innovation Partnership on Active and Healthy Ageing and the AIRWAYS ICPs network. It is deployed in collaboration with the World Health Organization Global Alliance against Chronic Respiratory Diseases (GARD). The European Innovation Partnership on Active and Healthy Ageing has proposed a 5-step framework for developing an individual scaling up strategy: (1) what to scale up: (1-a) databases of good practices, (1-b) assessment of viability of the scaling up of good practices, (1-c) classification of good practices for local replication and (2) how to scale up: (2-a) facilitating partnerships for scaling up, (2-b) implementation of key success factors and lessons learnt, including emerging technologies for individualised and predictive medicine. This strategy has already been applied to the chronic respiratory disease action plan of the European Innovation Partnership on Active and Healthy Ageing