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Novel Electrolysers for Clean Energy Production
No full textEnergy is fundamental to modern society, which relies on its production for survival and development. Current energy production entrusts almost entirely on the consumption of fossil fuels. However, this is not a sustainable energy source as there is only a finite supply and more importantly, it is detrimental to the environment. Electrochemical processes have been considered promising alternatives to reduce the over-dependence on fossil fuels. One of the key steps in making the processes practical relies on finding suitable catalysts that are active and stable for the relevant electrochemical reaction. Transition metal-based nanomaterials have unique physical and chemical properties and are considered valid alternatives to noble metals as catalysts. During this PhD, thorough research was conducted to investigate the OER performance of monometallic, bimetallic and trimetallic alloys, carbides and nitrides. These nano-catalysts are highly crystalline and homogeneous in composition. The morphology, surface structure, shape and size of these nano-catalysts were controllably modified to achieve desirable performance. In particular, NiFe/AC was found to be a superior catalyst with relatively high activity due to the synergistic effect and the distinct morphology of nanotubes, making it a more suitable candidate for large-scale production. The conventional way for producing ammonia at an industrial scale utilises the Haber-Bosch (H-B) process, which is known to be energy intensive as it operates at high temperature and high pressure. The H-B process is also a major contributor to climate change due to the large amount of CO2 emissions. Alternatively, the electrocatalytic nitrogen reduction reaction (NRR) represents a more sustainable and promising technology than the H-B process at ambient condition, and the transition metal nitrides (TMNs) are considered to be feasible catalysts for the NRR. In the third part of the current work, the stability of various transition multi-metallic nitrides under NRR condition was carried out. These catalysts were tested in relevant electrolytes for electrocatalysis, showing higher chemical resistance of the bimetallic catalysts over the monometallic ones. In addition, Pourbaix diagrams were employed to evaluate the feasibility of reducing TMNs to ammonia from a thermodynamic perspective. This study demonstrated a novel approach to matching electrolyte pH and catalyst to ensure chemical stability in the electrochemical environment. The synthesis method is cost-effective and environmentally friendly by using non-toxic precursors, i.e. urea as a reducing agent, and operating at a mild temperature, making the process suitable for large-scale application. Our work shows that the pathway towards the ideal catalysts for electrochemical processes relies on the rational design of tailored systems and this result can be achieved in an easy way
Association of left ventricular mass with discordant stress cardiac magnetic resonance and coronary angiography.
No full textAIMS: This study aimed to determine the impact of left ventricular mass (LVM) on discordant stress cardiac magnetic resonance (CMR) imaging and invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD) at coronary computed tomography angiography (CCTA). METHODS AND RESULTS: In this substudy of the Dan-NICAD 2 trial (NCT03481712), 354 patients with suspected obstructive CAD on CCTA were examined with both rest and stress CMR and ICA for invasive physiological measurements. An abnormal stress CMR was defined as ≥2 contiguous segments with a stress perfusion defect, late gadolinium enhancement, or wall motion abnormality. CMR-derived LVM was sex-adjusted by conversion from grams to per cent. Haemodynamically obstructive CAD at ICA was defined as visual diameter stenosis >90% or FFR ≤0.80. LVM was higher in patients with an abnormal stress CMR compared to those with a normal CMR (median difference = 8.0%, P < 0.001). Patients with or without haemodynamically obstructive CAD had similar LVM (median difference = 2%, P = 0.222). Within four binary groups based on normal/abnormal stress CMR and ICA, both median LVM and index of microvascular resistance were higher in patients with discordant abnormal stress CMR and normal ICA than in patients with concordant normal stress CMR and ICA (124% vs. 111%, P = 0.001, and 29 vs. 19, P = 0.072, respectively). CONCLUSION: In patients with suspected obstructive CAD, increased LVM can potentially confound concordance between stress CMR and ICA. This is due to increased microvascular resistance, which decreases the pressure gradient across an epicardial stenosis, resulting in a false high FFR and thus, normal ICA
Coenzyme A homeostasis regulates hypoxic signalling via UBFD1 in triple-negative breast cancer
No full textUnbiased recording and identification of thymic cellular interactomes using synthetic Notch receptors.
No full textClustering of Gravitational Wave Sources in Luminosity Distance Space
No full textGravitational waves (GWs) have rapidly emerged as valuable cosmological probes since their first detection in 2015. With upcoming third-generation detectors such as the Einstein Telescope (ET) and Cosmic Explorer (CE), millions of compact binary coalescences will be observed. When combined with large-scale structure surveys, like those from DESI, Euclid, the Vera Rubin Observatory, and the Square Kilometre Array (SKA), this opens up the opportunity to use GWs as tracers of the matter distribution in the Universe. This thesis presents a framework for employing GWs as large-scale structure tracers, analogous to galaxies, but observed in luminosity distance space — the only distance measure for GWs. We develop the formalism for clustering in this space, deriving the observed number count fluctuations and their dependence on relativistic effects. In particular, we model and analyse the impact of magnification and evolution biases, essential for interpreting the angular power spectrum of GW sources. Using Fisher forecasts, we quantify the precision with which these effects can be measured when GWs are cross-correlated with other tracers, including optical and radio galaxies as well as 21cm intensity mapping. We show that this multi-tracer approach can constrain the GW clustering bias at the few-percent level and enable percent-level detection of relativistic effects such as gravitational lensing, Doppler terms, and radial velocity distortions. Furthermore, we demonstrate that this methodology opens the door to measuring previously inaccessible contributions from gravitational potentials. Altogether, this thesis highlights the potential of gravitational waves as cosmological tracers of the underlying matter distribution. These results position gravitational waves as a new frontier for cosmology, offering an independent and powerful probe of structure formation and gravitational physics
Linking Health Financing to Oral Health Coverage and Disease Burden in SEARO Countries: A Cross-Sectional Analysis of Country Level Data.
Get PDFINTRODUCTION: The Southeast Asian region of World Health Organization (SEARO) comprising 11 countries, that is Bangladesh, Bhutan, Democratic People's Republic of Korea, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka, Thailand, and Timor-Leste is home to a quarter of the world's population where severe oral health disparities persist. AIM: This study aims to collate the oral health financing landscape, evaluate the relationship between government health expenditure and the burden of oral diseases, assess the proportionality of oral health spending relative to its share of the overall disease burden, and examine the inclusion and funding of dental care within Universal Health Coverage (UHC) benefit packages in the SEARO region. MATERIALS AND METHODS: Data for this study were sourced from publicly available databases and relevant national health statistics repositories of SEARO countries. These datasets provided information on health financing indicators, oral health coverage, and oral disease burden. Descriptive statistics were used to summarize indicators across SEARO countries. Correlation analyses were done to examine the interrelationship between health financing indicators and oral health outcomes and oral health coverage. RESULTS: Increased government expenditure on health was significantly and positively correlated with insurance and oral health coverage. It was inversely correlated with out-of-pocket expenses (OOPE), private health expenditure, borrowing money to cover health expenses, and 'All cause' DALYs (Disability Adjusted Life Years). There was no significant correlation between government health spending and 'Oral Disorders' DALYs. Increased private expenditure was inversely correlated with domestic general government health expenditure as a percentage of current health expenditure and oral health coverage and positively correlated with Out-of-pocket expenses and borrowing money for covering health expenses. The allocation of government spending did not correspond proportionately to the burden of oral diseases. DISCUSSION AND CONCLUSION: The lack of correlation between government health funding and the oral disease burden and the disproportionately low government expenditure on oral health relative to the burden of oral diseases when compared to their share of the total disease burden indicates not only a significant deficiency in funding but also misplaced funding priorities. There is a need to focus on the prevention of oral diseases and direct resources towards prevention, regular training, and education of healthcare workers and the public to identify early signs and symptoms of oral disease, rather than solely on treatment
A secondary multivariate decomposition analysis of factors influencing smokeless tobacco cessation across two Global Adult Tobacco Survey waves in India and Bangladesh.
Get PDFINTRODUCTION: This study explores patterns and determinants of attempted quitting of smokeless tobacco (AQSLT) in India and Bangladesh, using data from two waves of the Global Adult Tobacco Survey (GATS). METHODS: A secondary analysis was conducted using nationally representative data from GATS Wave 1 (2009-2010) and Wave 2 (2016-2017) in India and Bangladesh. Adults who reported using SLT currently or within 12 months at the time of each wave were included. Changes in AQSLT prevalence, associated factors, and contribution of independent variables were assessed using descriptive statistics, logistic regression, and multivariate decomposition analysis. RESULTS: While smokeless tobacco (SLT) use declined from Wave 1 to Wave 2 in both countries, changes in AQSLT prevalence were not statistically significant. In India, multivariate decomposition revealed that increases in the proportion of individuals who received quitting advice from a doctor or healthcare professional, noticed health warnings on SLT products, saw SLT warnings in print media, and were exposed to pro-SLT advertisements, had positive endowment effects on AQSLT. Behavioral changes among those exposed to SLT product warnings had the strongest negative composition effect. In Bangladesh, increased exposure to warnings in print media had positive, while decreased exposure to pro-SLT advertisements had a negative endowment effect on AQSLT. No significant composition effects were observed in Bangladesh. CONCLUSIONS: Interventions such as providing advice and health warnings show inconsistent effects on quit behavior. Findings warrant further evaluation of effectiveness of interventions and exploring tested culturally sensitive cessation strategies, that effectively motivate quit attempts among SLT users
Converging to mediocrity: Trends in firm-level markups in the United Kingdom 2008–2019
Get PDFUK manufacturing productivity has declined sharply since 2008, yet little is known about the role of trends in firm-level markups in this context. We estimate firm-level markups using a structural demand approach with revenue shares and industry elasticities, which is complemented by a primal method. Findings indicate a decline in aggregate markups of two to five per cent from 2008 to 2019, driven mainly by within-firm declines. These results suggest that the UK's productivity slowdown reflects structural deterioration within manufacturing firms rather than reallocation effects
Automatic acoustic identification of individual animals in the wild
No full textTraditionally, studies of animal vocal communication have focused on species-level analysis. While this approach has provided valuable insights, it often overlooks the individuality present within populations. Recent advances in technology, combined with novel research perspectives, have highlighted the importance of studying individual-level variation. This shift in focus reveals unique behaviours, ecological roles, and social dynamics that are critical for a deeper understanding of animal populations. In this thesis, we develop computational methods to advance automatic acoustic identification on individuals (AIID), with the goal of identifying individual animals based on their unique vocal characteristics. The latest advancements in machine learning (ML) inspire the development of robust methodologies design to perform AIID in real-world scenarios. The methods are developed to address key challenges such as generalization across multiple species and open world classification, where neither the species nor the individuals present are fully known. Unlike traditional species-level bioacoustic studies, this work adopts a novel hierarchical framework, accounting for the taxonomic relationships among species and individuals. This approach not only enhances AIID performance but also provides new insights into vocal recognition mechanisms across the different taxonomic groups. The thesis first establishes a baseline for multispecies AIID by curating a novel dataset comprising vocalisations annotated at the individual level for both mammals and birds. Classification-based training methods are adopted to first evaluate the benefits of incorporating taxonomic information into the training process. To address the inherent challenges of AIID in the wild, particularly open world classification and the limited availability of annotated data, the thesis further explores alternative training paradigms based on distance learning. The results demonstrate that integrating hierarchical constraints into AIID frameworks significantly improves identification performance across all taxonomic levels while enhancing generalization to unseen individuals and species. These findings advance the technical capabilities of AIID systems and underscore their potential to drive progress in animal behaviour research and conservation efforts
A chromosome-level assembly and functional genomic resources for the model annelid Capitella teleta.
Get PDFThe polychaete Capitella teleta is a primary model for evolutionary developmental biology, comparative genomics, conservation, and ecotoxicology. Although it was the first polychaete genome sequenced, the original assembly is outdated by modern standards. Here, we combine long-read and short-read sequencing with Hi-C chromatin conformation capture to assemble chromosome-level nuclear and mitochondrial genomes of the laboratory strain of C. teleta. This reference assembly accurately reflects the expected genome size (∼243.6 Mb) and contains a highly complete, evolutionarily conserved gene repertoire. Notably, the nuclear and mitochondrial genomes are heavily rearranged, indicating a decoupling between gene family repertoire and chromosomal evolution. The analyses of developmental time courses of bulk and single-cell RNA-seq, ATAC-seq, and EM-seq data using the new reference assembly resulted in a significant improvement in quality, enabling the identification of new cell-type-specific gene markers. Finally, we generated a publicly available genome browser that ensures these resources comply with FAIR principles. Our study provides state-of-the-art genomic resources for C. teleta, addressing a pressing community need and opening new research opportunities in animal and genome evolution