High contrast imaging and thickness determination of graphene with in-column secondary electron microscopy

We report a new method for quantitative estimation of graphene layer thicknesses using high contrast imaging of graphene films on insulating substrates with a scanning electron microscope. By detecting the attenuation of secondary electrons emitted from the substrate with an in-column low-energy electron detector, we have achieved very high thickness-dependent contrast that allows quantitative estimation of thickness up to several graphene layers. The nanometer scale spatial resolution of the electron micrographs also allows a simple structural characterization scheme for graphene, which has been applied to identify faults, wrinkles, voids, and patches of multilayer growth in large-area chemical vapor deposited graphene. We have discussed the factors, such as differential surface charging and electron beam induced current, that affect the contrast of graphene images in detail.Comment: 5 pages, 4 figure

Recovering Knowledge Commons for the Global South

The colonial encounter instituted the hegemony of documentary practices over oral, performative and manuscript practices. Only knowledge validated through the process of print publication could stand the test of legal scrutiny. On the one hand the Western epistemological quest glossed over ideas that existed through ephemera, on the other hand that knowledge which Western print practices imbibed from non-European traditions were henceforth, locked behind intellectual property regimes and restrictive archival practices. This tremendously skewed access to knowledge between the North and the South. Tools for digital transformation, particularly those that are based on artificial intelligence (AI) and machine learning (ML), can be culture specific e.g. training data for Optical  Character Recognition (OCR)/ Hand-written Text Recognition (HTR); datasets for natural language processing. In the absence of culture specific tools in underdeveloped societies Anglo-American interpretive categories and assumptions become the default. Further, Anglo-American institutions work to use their advantage in the balance of knowledge distribution to maintain their hegemonic position. In order to protect the South’s access to human heritage and knowledge we need to develop technologies that leverage the potentials of digital communication for increased conversations among languages of the South

Adult life course determinants of cardiac structure and function in the Medical Research Council 1946 birth cohort

Background: Elevated blood pressure (BP) and body mass index (BMI) are associated with abnormalities of cardiac structure and dysfunction in cross-sectional studies. However the consequence of elevated BP and BMI over the adult life course on cardiac structure and function is unknown. Methods: Participants in the Medical Research Council National Survey of Health and Development (MRC NSHD) 1946 birth cohort (n=1653) underwent investigations including echocardiography and BP and BMI measurement at age 60-64y. BP had been measured previously at ages 36, 43 and 53y and BMI had previously been measured at ages 20, 26, 36, 43 and 53y. The relationships between BP, treatment for hypertension (HTT) and BMI and echocardiographic determinants of cardiac structure and function at age 60-64y were investigated. Results: Increased BP from age 36y onwards was associated with increased left ventricular mass index (LVMI) and poorer diastolic function (E/e’). This was independent of BP at age 60-64y for BP measured at age 53y. Faster rises of BP across mid-life were associated with greater increases in LVMI and E/e’. HTT was associated with increased LVMI and E/e’ after adjustment for BP at age 60-64y. Associations with systolic function were inconsistent. Increased BMI and overweight from the age of 20y onwards was associated with increased LVMI and poorer diastolic function. On including BMI/overweight at ages 60-64y, the associations remained for some ages (e.g. for ages 26y and 43y for LVMI and from age 36y onwards for E/e’). Earlier age at first detection of overweight was associated with increased LVMI and diastolic dysfunction. Associations with systolic function were inconsistent. Conclusions: Increased adult life course BP and BMI are associated with increased LVMI and diastolic dysfunction. Increased rate of change in BP is associated with detrimental effects to cardiac structure and function as is HTT. Earlier age of first detection of overweight is associated with increased LVMI and diastolic dysfunction. Earlier interventions to prevent rapid rises in BP and the development of obesity may be key in preventing future abnormalities in cardiac structure and function

UTRNet: High-Resolution Urdu Text Recognition In Printed Documents

In this paper, we propose a novel approach to address the challenges of printed Urdu text recognition using high-resolution, multi-scale semantic feature extraction. Our proposed UTRNet architecture, a hybrid CNN-RNN model, demonstrates state-of-the-art performance on benchmark datasets. To address the limitations of previous works, which struggle to generalize to the intricacies of the Urdu script and the lack of sufficient annotated real-world data, we have introduced the UTRSet-Real, a large-scale annotated real-world dataset comprising over 11,000 lines and UTRSet-Synth, a synthetic dataset with 20,000 lines closely resembling real-world and made corrections to the ground truth of the existing IIITH dataset, making it a more reliable resource for future research. We also provide UrduDoc, a benchmark dataset for Urdu text line detection in scanned documents. Additionally, we have developed an online tool for end-to-end Urdu OCR from printed documents by integrating UTRNet with a text detection model. Our work not only addresses the current limitations of Urdu OCR but also paves the way for future research in this area and facilitates the continued advancement of Urdu OCR technology. The project page with source code, datasets, annotations, trained models, and online tool is available at abdur75648.github.io/UTRNet.Comment: Accepted at The 17th International Conference on Document Analysis and Recognition (ICDAR 2023

Life Course Socioeconomic Position: associations with cardiac structure and function at age 60-64 years in the 1946 British Birth Cohort

Although it is recognized that risks of cardiovascular diseases associated with heart failure develop over the life course, no studies have reported whether life course socioeconomic inequalities exist for heart failure risk. The Medical Research Council’s National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and measures of cardiac structure [left ventricular (LV) mass index and relative wall thickness (RWT)] and function [systolic: ejection fraction (EF) and midwall fractional shortening (mFS); diastolic: left atrial (LA) volume, E/A ratio and E/e’ ratio)]. Different life course models were compared with a saturated model to ascertain the nature of the relationship between socioeconomic position across the life course and each cardiac marker. Findings showed that models where socioeconomic position accumulated over multiple time points in life provided the best fit for 3 of the 7 cardiac markers: childhood and early adulthood periods for the E/A ratio and E/e’ ratio, and all three life periods for LV mass index. These associations were attenuated by adjustment for adiposity, but were little affected by adjustment for other established or novel cardio-metabolic risk factors. There was no evidence of a relationship between socioeconomic position at any time point and RWT, EF, mFS or LA volume index. In conclusion, socioeconomic position across multiple points of the lifecourse, particularly earlier in life, is an important determinant of some measures of LV structure and function. BMI may be an important mediator of these associations

Rate of telomere shortening and cardiovascular damage: a longitudinal study in the 1946 British Birth Cohort.

AIM: Cross-sectional studies reported associations between short leucocyte telomere length (LTL) and measures of vascular and cardiac damage. However, the contribution of LTL dynamics to the age-related process of cardiovascular (CV) remodelling remains unknown. In this study, we explored whether the rate of LTL shortening can predict CV phenotypes over 10-year follow-up and the influence of established CV risk factors on this relationship. METHODS AND RESULTS: All the participants from the MRC National Survey of Health and Development (NSHD) with measures of LTL and traditional CV risk factors at 53 and 60-64 years and common carotid intima-media thickness (cIMT), cardiac mass and left ventricular function at 60-64 years were included. LTL was measured by real-time polymerase chain reaction and available at both time points in 1033 individuals. While LTL at 53 years was not linked with any CV phenotype at 60-64 years, a negative association was found between LTL and cIMT at 60-64 years (β = -0.017, P = 0.015). However, the strongest association was found between rate of telomere shortening between 53 and 60-64 years and values of cIMT at 60-64 years (β = -0.020, P = 0.006). This association was not affected by adjustment for traditional CV risk factors. Cardiac measurements were not associated with cross-sectional or longitudinal measures of LTL. CONCLUSION: These findings suggest that the rate of progression of cellular ageing in late midlife (reflected by the rate of LTL attrition) relates to vascular damage, independently from contribution of CV risk factor exposure

Designing Optimal Convolutional Neural Network Architecture Using Differential Evolution Algorithm

Convolutional neural networks (CNNs) are deep learning models used widely for solving various tasks like computer vision and speech recognition. CNNs are developed manually based on problem-specific domain knowledge and tricky settings, which are laborious, time consuming, and challenging. To solve these, our study develops an improved differential evolution of convolutional neural network (IDECNN) algorithm to design CNN layer architectures for image classification. Variable-length encoding is utilized to represent the flexible layer architecture of a CNN model in IDECNN. An efficient heuristic mechanism is proposed in IDECNN to evolve CNN architecture through mutation and crossover to prevent premature convergence during the evolutionary process. Eight well-known imaging datasets were utilized. The results showed that IDECNN could design suitable architecture compared with 20 existing CNN models. Finally, CNN architectures are applied to pneumonia and coronavirus disease 2019 (COVID-19) X-ray biomedical image data. The results demonstrated the usefulness of the proposed approach to generate a suitable CNN model

The 10th Biennial Hatter Cardiovascular Institute workshop: cellular protection—evaluating new directions in the setting of myocardial infarction, ischaemic stroke, and cardio-oncology

Due to its poor capacity for regeneration, the heart is particularly sensitive to the loss of contractile cardiomyocytes. The onslaught of damage caused by ischaemia and reperfusion, occurring during an acute myocardial infarction and the subsequent reperfusion therapy, can wipe out upwards of a billion cardiomyocytes. A similar program of cell death can cause the irreversible loss of neurons in ischaemic stroke. Similar pathways of lethal cell injury can contribute to other pathologies such as left ventricular dysfunction and heart failure caused by cancer therapy. Consequently, strategies designed to protect the heart from lethal cell injury have the potential to be applicable across all three pathologies. The investigators meeting at the 10th Hatter Cardiovascular Institute workshop examined the parallels between ST-segment elevation myocardial infarction (STEMI), ischaemic stroke, and other pathologies that cause the loss of cardiomyocytes including cancer therapeutic cardiotoxicity. They examined the prospects for protection by remote ischaemic conditioning (RIC) in each scenario, and evaluated impasses and novel opportunities for cellular protection, with the future landscape for RIC in the clinical setting to be determined by the outcome of the large ERIC-PPCI/CONDI2 study. It was agreed that the way forward must include measures to improve experimental methodologies, such that they better reflect the clinical scenario and to judiciously select combinations of therapies targeting specific pathways of cellular death and injury

Liver Metabolic Alterations and Changes in Host Intercompartmental Metabolic Correlation during Progression of Malaria

1H NMR-based metabonomics was used to investigate the multimodal response of mice to malarial parasite infection by P. berghei ANKA. Liver metabolism was followed by NMR spectroscopy through the course of the disease in both male and female mice. Our results showed alterations in the level of several metabolites as a result of the infection. Metabolites like kynurenic acid, alanine, carnitine, and β-alanine showed significant alteration in the liver, suggesting altered kynurenic acid, glucose, fatty acid and amino acid pathways. Distinct sexual dimorphism was also observed in the global analysis of the liver metabolic profiles. Multiway principal component analysis (MPCA) was carried out on the liver, brain, and serum metabolic profile in order to explore the correlation of liver and brain metabolic profile to the metabolite profile of serum. Changes in such correlation profile also indicated distinct sexual dimorphism at the early stage of the disease. Indications are that the females are able to regulate their metabolism in the liver in such a way to maintain homeostasis in the blood. In males, however, choline in liver showed anticorrelation to choline content of serum indicating a higher phospholipid degradation process. The brain-serum correlation profile showed an altered energy metabolism in both the sexes. The differential organellar responses during disease progression have implications in malaria management