Quiver Structure of Heterotic Moduli

We analyse the vector bundle moduli arising from generic heterotic compactifications from the point of view of quiver representations. Phenomena such as stability walls, crossing between chambers of supersymmetry, splitting of non-Abelian bundles and dynamic generation of D-terms are succinctly encoded into finite quivers. By studying the Poincar\'e polynomial of the quiver moduli space using the Reineke formula, we can learn about such useful concepts as Donaldson-Thomas invariants, instanton transitions and supersymmetry breaking.Comment: 38 pages, 5 figures, 1 tabl

A truly hyperbolic elastic metamaterial lens

Sub-wavelength imaging is possible if metamaterial lenses realizing hyperbolic or elliptic Equi-Frequency Contours (EFCs) are used. Theoretically, lenses exhibiting hyperbolic EFCs allow imaging with unlimited resolution, but only metamaterials of elliptic EFCs producing limited resolution have been so far realized in elastic field. Thus, an elastic metamaterial lens realizing truly hyperbolic EFCs can lead to superior-resolution ultrasonic imaging. This Letter presents the realization of an elastic lens exhibiting truly hyperbolic EFCs and its experimental verification. (C) 2014 AIP Publishing LLCclos

Investigating the Performance and Safety of Li-Ion Cylindrical Cells Using Acoustic Emission and Machine Learning Analysis

Acoustic emission (AE) is a low-cost, non-invasive, and accessible diagnostic technique that uses a piezoelectric sensor to detect ultrasonic elastic waves generated by the rapid release of energy from a localised source. Despite the ubiquity of the cylindrical cell format, AE techniques applied to this cell type are rare in literature due to the complexity of acoustic wave propagation in cylindrical architectures alongside the challenges associated with sensor coupling. Here, we correlate the electrochemical performance of cells with their AE response, examining the differences during pristine and aged cell cycling. AE data was obtained and used to train various supervised binary classifiers in a supervised setting, differentiating pristine from aged cells. The highest accuracy was achieved by a deep neural network model. Unsupervised machine learning (ML) models, combining dimensionality reduction techniques with clustering, were also developed to group AE signals according to their form. The groups were then related to battery degradation phenomena such as electrode cracking, gas formation, and electrode expansion. There is the potential to integrate this novel ML-driven approach for widespread cylindrical cell testing in both academic and commercial settings to help improve the safety and performance of lithium-ion batteries

Inverted bi-prism phononic crystals for one-sided elastic wave transmission applications

This work presents the realization of one-sided wave transmission by using a specially engineered phononic crystal structure. It is an inverted bi-prism phononic crystal engineered for a horizontally incident elastic wave at a specific frequency. The incident wave along one direction is shown to be totally reflected by the bi-prism while the incident wave along the opposite direction transmitted through it with refraction, also evident from experiments. An application of the proposed bi-prism may be found in thin elastic strips. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721485clos

The impact of education on cortical thickness in amyloid-negative subcortical vascular dementia: cognitive reserve hypothesis

Background: The protective effect of education has been well established in Alzheimer's disease, whereas its role in patients with isolated cerebrovascular diseases remains unclear. We examined the correlation of education with cortical thickness and cerebral small vessel disease markers in patients with pure subcortical vascular mild cognitive impairment (svMCl) and patients with pure subcortical vascular dementia (SVaD). Methods: We analyzed 45 patients with svMCl and 47 patients with SVaD with negative results on Pittsburgh compound B positron emission tomographic imaging who underwent structural brain magnetic resonance imaging. The main outcome was cortical thickness measured using surface-based morphometric analysis. We also assessed the volumes of white matter hyperintensities (WMH) and numbers of lacunes as other outcomes. To investigate the correlation of education with cortical thickness, WMH volume, and number of lacunes, multiple linear regression analyses were performed after controlling for covariates, including Mini Mental State Examination, in the svMCl and SVaD groups. Results: In the SVaD group, higher education was correlated with more severe cortical thinning in the bilateral dorsolateral frontal, left medial frontal, and parahippocampal areas, whereas there was no correlation of education with cortical thickness in the svMCl group. There was no correlation between education and cerebral small vessel disease, including WMH and lacunes, in both patients with svMCl and patients with SVaD. Conclusions: Our findings suggest that the compensatory effects of education on cortical thinning apply to patients with SVaD, which might be explained by the cognitive reserve hypothesis

The Effects of Longitudinal White Matter Hyperintensity Change on Cognitive Decline and Cortical Thinning over Three Years

White matter hyperintensity (WMH) has been recognised as a surrogate marker of small vessel disease and is associated with cognitive impairment. We investigated the dynamic change in WMH in patients with severe WMH at baseline, and the effects of longitudinal change of WMH volume on cognitive decline and cortical thinning. Eighty-seven patients with subcortical vascular mild cognitive impairment were prospectively recruited from a single referral centre. All of the patients were followed up with annual neuropsychological tests and 3T brain magnetic resonance imaging. The WMH volume was quantified using an automated method and the cortical thickness was measured using surface-based methods. Participants were classified into WMH progression and WMH regression groups based on the delta WMH volume between the baseline and the last follow-up. To investigate the effects of longitudinal change in WMH volume on cognitive decline and cortical thinning, a linear mixed effects model was used. Seventy patients showed WMH progression and 17 showed WMH regression over a three-year period. The WMH progression group showed more rapid cortical thinning in widespread regions compared with the WMH regression group. However, the rate of cognitive decline in language, visuospatial function, memory and executive function, and general cognitive function was not different between the two groups. The results of this study indicated that WMH volume changes are dynamic and WMH progression is associated with more rapid cortical thinning

Comparison of extended reality and conventional methods of basic life support training: protocol for a multinational, pragmatic, noninferiority, randomised clinical trial (XR BLS trial)

Abstract Background Conventional cardiopulmonary resuscitation (CPR) training for the general public involves the use of a manikin and a training video, which has limitations related to a lack of realism and immersion. To overcome these limitations, virtual reality and extended reality technologies are being used in the field of medical education. The aim of this study is to explore the efficacy and safety of extended reality (XR)-based basic life support (BLS) training. Methods This study is a prospective, multinational, multicentre, randomised controlled study. Four institutions in 4 countries will participate in the study. A total of 154 participants will be randomly assigned to either the XR group or the conventional group stratified by institution and sex (1:1 ratio). Each participant who is allocated to either group will be sent to a separate room to receive training with an XR BLS module or conventional CPR training video. All participants will perform a test on a CPR manikin after the training. The primary outcome will be mean compression depth. The secondary outcome will be overall BLS performance, including compression rate, correct hand position, compression, and full release and hands-off time. Discussion Using virtual reality (VR) to establish a virtual educational environment can give trainees a sense of realism. In the XR environment, which combines the virtual world with the real world, trainees can more effectively learn various skills. This trial will provide evidence of the usefulness of XR in CPR education. Trial registration ClinicalTrials.gov NCT04736888. Registered on 29 January 202

The gene-reduction effect of chromosomal losses detected in gastric cancers

<p>Abstract</p> <p>Background</p> <p>The level of loss of heterozygosity (LOH) that reduces a gene dose and exerts a cell-adverse effect is known to be a parameter for the genetic staging of gastric cancers. This study investigated if the cell-adverse effect induced with the gene reduction was a rate-limiting factor for the LOH events in two distinct histologic types of gastric cancers, the diffuse- and intestinal-types.</p> <p>Methods</p> <p>The pathologic specimens obtained from 145 gastric cancer patients were examined for the level of LOH using 40 microsatellite markers on eight cancer-associated chromosomes (3p, 4p, 5q, 8p, 9p, 13q, 17p and 18q).</p> <p>Results</p> <p>Most of the cancer-associated chromosomes were found to belong to the gene-poor chromosomes and to contain a few stomach-specific genes that were highly expressed. A baseline-level LOH involving one or no chromosome was frequent in diffuse-type gastric cancers. The chromosome 17 containing a relatively high density of genes was commonly lost in intestinal-type cancers but not in diffuse-type cancers. A high-level LOH involving four or more chromosomes tended to be frequent in the gastric cancers with intestinal and mixed differentiation. Disease relapse was common for gastric cancers with high-level LOH through both the hematogenous (38%) and non-hematogenous (36%) routes, and for the baseline-level LOH cases through the non-hematogenous route (67%).</p> <p>Conclusions</p> <p>The cell-adverse effect of gene reduction is more tolerated in intestinal-type gastric cancers than in diffuse-type cancers, and the loss of high-dose genes is associated with hematogenous metastasis.</p

Identification of a Systemic Lupus Erythematosus Risk Locus Spanning ATG16L2, FCHSD2, and P2RY2 in Koreans

Objective Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder whose etiology is incompletely understood, but likely involves environmental triggers in genetically susceptible individuals. Using an unbiased genome-wide association (GWA) scan and replication analysis, we sought to identify the genetic loci associated with SLE in a Korean population. Methods A total of 1,174 SLE cases and 4,246 population controls from Korea were genotyped and analyzed with a GWA scan to identify single-nucleotide polymorphisms (SNPs) significantly associated with SLE, after strict quality control measures were applied. For select variants, replication of SLE risk loci was tested in an independent data set of 1,416 SLE cases and 1,145 population controls from Korea and China. Results Eleven regions outside the HLA exceeded the genome-wide significance level (P = 5 × 10-8). A novel SNP-SLE association was identified between FCHSD2 and P2RY2, peaking at rs11235667 (P = 1.03 × 10-8, odds ratio [OR] 0.59) on a 33-kb haplotype upstream of ATG16L2. In the independent replication data set, the SNP rs11235667 continued to show a significant association with SLE (replication meta-analysis P = 0.001, overall meta-analysis P = 6.67 × 10-11; OR 0.63). Within the HLA region, the SNP-SLE association peaked in the class II region at rs116727542, with multiple independent effects observed in this region. Classic HLA allele imputation analysis identified HLA-DRB1∗1501 and HLA-DQB1∗0602, each highly correlated with one another, as most strongly associated with SLE. Ten previously established SLE risk loci were replicated: STAT1-STAT4, TNFSF4, TNFAIP3, IKZF1, HIP1, IRF5, BLK, WDFY4, ETS1, and IRAK1-MECP2. Of these loci, previously unreported, independent second risk effects of SNPs in TNFAIP3 and TNFSF4, as well as differences in the association with a putative causal variant in the WDFY4 region, were identified. Conclusion Further studies are needed to identify true SLE risk effects in other loci suggestive of a significant association, and to identify the causal variants in the regions of ATG16L2, FCHSD2, and P2RY2.</p