Bayesian analysis using MCMC methods of record values based on a new generalised Rayleigh distribution

In this paper, we extend the Rayleigh distribution to create a generalised Rayleigh distribution which is more flexible than the standard. The general properties of the new distribution are derived and investigated, with properties of more standard distributions, such as the exponential, standard Rayleigh and the Weibull, appearing as special cases. Further, we consider maximum likelihood estimation and Bayesian inference under the assumptions of gamma prior distributions on model parameters. Point estimates and confidence intervals based on maximum likelihood estimation are computed. The main challenge, however, is that the Bayesian estimators cannot easily be found and hence, Markov chain Monte Carlo (MCMC) techniques are proposed to generate samples from the posterior distributions leading to approximate posterior inference. The approximate Bayes estimators are compared with the maximum likelihood estimators using simulated data showing dramatic superiority of the Bayesian approach

Endothelial Depletion of Acvrl1 in Mice Leads to Arteriovenous Malformations Associated with Reduced Endoglin Expression

Rare inherited cardiovascular diseases are frequently caused by mutations in genes that are essential for the formation and/ or function of the cardiovasculature. Hereditary Haemorrhagic Telangiectasia is a familial disease of this type. The majority of patients carry mutations in either Endoglin (ENG) or ACVRL1 (also known as ALK1) genes, and the disease is characterized by arteriovenous malformations and persistent haemorrhage. ENG and ACVRL1 encode receptors for the TGF beta superfamily of ligands, that are essential for angiogenesis in early development but their roles are not fully understood. Our goal was to examine the role of Acvrl1 in vascular endothelial cells during vascular development and to determine whether loss of endothelial Acvrl1 leads to arteriovenous malformations. Acvrl1 was depleted in endothelial cells either in early postnatal life or in adult mice. Using the neonatal retinal plexus to examine angiogenesis, we observed that loss of endothelial Acvrl1 led to venous enlargement, vascular hyperbranching and arteriovenous malformations. These phenotypes were associated with loss of arterial Jag1 expression, decreased pSmad1/5/8 activity and increased endothelial cell proliferation. We found that Endoglin was markedly down-regulated in Acvrl1-depleted ECs showing endoglin expression to be downstream of Acvrl1 signalling in vivo. Endothelial-specific depletion of Acvrl1 in pups also led to pulmonary haemorrhage, but in adult mice resulted in caecal haemorrhage and fatal anaemia. We conclude that during development, endothelial Acvrl1 plays an essential role to regulate endothelial cell proliferation and arterial identity during angiogenesis, whilst in adult life endothelial Acvrl1 is required to maintain vascular integrity

Nanosized nickel hexacyanoferrate modified screen-printed electrodes as flexible supercabattery platforms: Influence of annealing temperatures and supporting electrolytes

Water-insoluble nickel hexacyanoferrate Ni3[Fe(CN)6]2.nH2O (NiHCF) nanoparticles were synthesized via a facile precipitation method in the presence of polyvinylpyrrolidone (PVP) and sodium citrate (SC). Large-scale production of cubic NiHCF crystals with an average diameter of 35 nm and a specific surface area (SBET) of 452.9 m2/g was shown to be possible. The NiHCF nanoparticles were drop-cast upon screen-printed graphite macroelectrode surfaces (SPEs) allowing a flexible energy storage device to be realised. The tunable pore size and dual functional reactive sites offered superior specific capacitances of 197.5, 139.35, 356.25, and 406.25 F/g in 0.1 M KCl, 0.1 M NaCl, 0.1 M NaOH and 0.1 M KOH, respectively at a current density of 5 A/g. The highest capacitance was found using 0.1 M KOH supporting electrolyte due to the combination of surface (intercalation/de-intercalation of A+) and faradaic processes (M2+/M3+) as supercabattery platforms. The thermal treatment of the NiHCF samples at 100, 200, 300 °C were performed within oxygen and nitrogen atmospheres and the specific capacitances were measured in 0.1 M KOH. Interestingly, the specific capacitance increases up to 546 F/g for NiHCF annealed at 100 °C in oxygen and reduces to 342 F/g if NiHCF when annealed at 200 °C in nitrogen atmospheres due to the likely introduction of diverse vacancies. Furthermore, the NiHCF/SPEs were investigated in an as-symmetric two-electrode system, which revealed a specific capacitance of 570 F/g at 5 A/g. The NiHCF/SPE exhibited high capability rate, capacitive retention and excellent cycling stabilities particularly if NiHCF was annealed within a nitrogen atmosphere. Thus, the NiHCF supercabattery platforms can be used for developing new flexible energy storage devices

Impact of Right Ventricular Dysfunction on Mortality in Patients Hospitalized with COVID-19 according to Race

Background: Epidemiological studies suggest that black, Asian and minority ethnic (BAME) patients may be at risk of worse outcomes from Coronavirus-19 (COVID-19) but the pathophysiological drivers for this association are unknown. This study sought to investigate the relationship between findings on echocardiography, mortality and race in COVID-19 pneumonia. Methods: This was a multicenter, retrospective, observational study including 164 adults (61±13years; 78% male; 36% BAME) hospitalized with COVID-19 undergoing echocardiography between March 16 and May 9, 2020 at 3 days (IQR 2 - 5) from admission. The primary outcome was all-cause mortality. Results: After a median follow up of 31 days (IQR 14 - 42 days), 58 (35%) patients had died. The right ventricle (RV) was dilated in 62 (38%) patients, and 58 (35%) patients had RV systolic dysfunction. Only 2 (1%) patients had left ventricular (LV) dilatation and 133 (81%) had normal or hyperdynamic LV systolic function. Reduced tricuspid annulus planar systolic excursion was associated with elevated D-dimer (ρ = -0.18, p = 0.025) and high-sensitivity cardiac Troponin (ρ = -0.30, p < 0.0001). Reduced RV systolic function (HR, 1.80; 95% CI, 1.05 - 3.09; p = 0.032) was an independent predictor of all-cause mortality after adjustment for demographic and clinical risk factors. Comparing white and BAME individuals, there were no differences in echocardiography findings, biomarkers or mortality. Conclusions: In patients hospitalized with COVID-19 pneumonia, reduced RV systolic function is prevalent and associated with all-cause mortality. There is however, no racial variation in the early findings on echocardiography, biomarkers or mortality

A reverse engineering approach to the suppression of citation biases reveals universal properties of citation distributions

The large amount of information contained in bibliographic databases has recently boosted the use of citations, and other indicators based on citation numbers, as tools for the quantitative assessment of scientific research. Citations counts are often interpreted as proxies for the scientific influence of papers, journals, scholars, and institutions. However, a rigorous and scientifically grounded methodology for a correct use of citation counts is still missing. In particular, cross-disciplinary comparisons in terms of raw citation counts systematically favors scientific disciplines with higher citation and publication rates. Here we perform an exhaustive study of the citation patterns of millions of papers, and derive a simple transformation of citation counts able to suppress the disproportionate citation counts among scientific domains. We find that the transformation is well described by a power-law function, and that the parameter values of the transformation are typical features of each scientific discipline. Universal properties of citation patterns descend therefore from the fact that citation distributions for papers in a specific field are all part of the same family of univariate distributions.Comment: 9 pages, 6 figures. Supporting information files available at http://filrad.homelinux.or

Alternative Routes for a Proposed Nigerian Superhighway to Limit Damage to Rare Ecosystems and Wildlife

The Cross River State Government in Nigeria is proposing to construct a ‘‘Cross River Superhighway’’ that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated ～US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (～290 and ～353 km, respectively) and have markedly lower estimated construction costs (～US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway

Improved Melting of Latent Heat Storage Using Fin Arrays with Non-Uniform Dimensions and Distinct Patterns

Data Availability Statement: Not applicable.Copyright: © 2022 by the authors. Employing phase-change materials (PCM) is considered a very efficient and cost-effective option for addressing the mismatch between the energy supply and the demand. The high storage density, little temperature degradation, and ease of material processing register the PCM as a key candidate for the thermal energy storage system. However, the sluggish response rates during their melting and solidification processes limit their applications and consequently require the inclusion of heat transfer enhancers. This research aims to investigate the potential enhancement of circular fins on intensifying the PCM thermal response in a vertical triple-tube casing. Fin arrays of non-uniform dimensions and distinct distribution patterns were designed and investigated to determine the impact of modifying the fin geometric characteristics and distribution patterns in various spatial zones of the heat exchanger. Parametric analysis on the various fin structures under consideration was carried out to determine the most optimal fin structure from the perspective of the transient melting evolution and heat storage rates while maintaining the same design limitations of fin material and volume usage. The results revealed that changing the fin dimensions with the heat-flow direction results in a faster charging rate, a higher storage rate, and a more uniform temperature distribution when compared to a uniform fin size. The time required to fully charge the storage system (fully melting of the PCM) was found to be reduced by up to 10.4%, and the heat storage rate can be improved by up to 9.3% compared to the reference case of uniform fin sizes within the same fin volume limitations.Funding: This research received no external funding