A Hilbert-space variant of Geršgorin's circle theorem
We provide a variant of Geršgorin's circle theorem, where the -estimates are swapped for -estimates, more suitable for the infinite-dimensional Hilbert space setting.
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We provide a variant of Geršgorin's circle theorem, where the -estimates are swapped for -estimates, more suitable for the infinite-dimensional Hilbert space setting.
This commentary highlights two cross-cultural issues identified from our global mental health (GMH) research, RECOLLECT (Recovery Colleges Characterisation and Testing) 2: self-enhancement and ingroup biases. Self-enhancement is a tendency to maintain and express unrealistically positive self-views. Ingroup biases are differences in one’s evaluation of others belonging to the same social group. Th
INTRODUCTION: Maternal-neonatal healthcare services were severely disrupted during the COVID-19 pandemic in even high-income countries within the World Health Organization (WHO) European Region. The objective of this study was to compare trends in the quality of maternal and neonatal care (QMNC) in Sweden and Norway to 12 other countries from the WHO European Region during the COVID-19 pandemic, a
We investigate the use of atmospheric oxygen (O2) and carbon dioxide (CO2) measurements for the estimation of the fossil fuel component of atmospheric CO2 in the UK. Atmospheric potential oxygen (APO) - a tracer that combines O2 and CO2, minimizing the influence of terrestrial biosphere fluxes - is simulated at three sites in the UK, two of which make APO measurements. We present a set of model ex
Preconcentration of methane (CH4) from air is a critical sampling step in the measurement of singly and doubly substituted isotopologue ratios. We demonstrate the potential for isotope fractionation during preconcentration onto and elution from the common trapping material HayeSep-D and investigate its significance in laser spectroscopy measurements. By altering the trapping temperature for adsorp
We use the GEOS-Chem global 3-D model and two inverse methods (the maximum a posteriori and ensemble Kalman filter) to infer regional methane (CH4) emissions and the corresponding stable-carbon-isotope source signatures from 2004-2020 across the globe using in situ and satellite remote sensing data. We use the Siegel estimator to determine linear trends from the in situ data. Over our 17-year stud
We have employed a new approach to quantify the amount fraction of nitrous oxide in a synthetic air matrix gas used to prepare high-accuracy reference materials of the same component. Until now, this was the largest contributor to the measurement uncertainty of nitrous oxide in air reference materials at atmospheric amount fractions (∼330 nmol mol-1), as identified in a recent international compar
We present a method for estimating fossil fuel methane emissions using observations of methane and ethane, accounting for uncertainty in their emission ratio. The ethane:methane emission ratio is incorporated as a spatially and temporally variable parameter in a Bayesian model, with its own prior distribution and uncertainty. We find that using an emission ratio distribution mitigates bias from us
Atmospheric measurements can be used as a tool to evaluate national greenhouse gas inventories through inverse modelling. Using 8 years of continuous methane (CH4) concentration data, this work assesses the United Kingdom's (UK) CH4 emissions over the period 2013-2020. Using two different inversion methods, we find mean emissions of 2.10±0.09 and 2.12±0.26Tgyr-1 between 2013 and 2020, an overall t
Atmospheric methane (CH4) and its isotopic composition trends over the last decades are explained by various flux scenarios, from tropical wetland emission increases through to reductions in global hydroxyl (OH). In this study, we develop a modeling framework to assess the potential usefulness of clumped isotope measurements to distinguish between the main drivers of change in the CH4 burden. We m
Radon gas is the largest source of public exposure to naturally occurring radioactivity. However, radon is also a useful tracer for understanding atmospheric processes, assessing the accuracy of chemical transport models, and enabling integrated emissions estimates of greenhouse gases. A sound metrological system for low level atmospheric radon observations is therefore needed for the benefit of t
It is estimated that global anthropogenic carbon dioxide (CO2) emissions reduced by up to 12% at the start of 2020 compared to recent years due to the COVID-19 related downturn in economic activity. Despite the large decrease in CO2 emissions, no reduction in the trend in background atmospheric CO2 concentrations has been detected. So, how long would it take for sustained COVID-19 CO2 emission red
This study reports thermodynamic and kinetic data of Sb(III) adsorption from single metal solutions onto synthetic aqueous goethite (α-FeOOH). Batch equilibrium sorption experiments were carried out at 25 °C over a Sb:Fe molar range of 0.005-0.05 and using a goethite concentration of 0.44 g Fe/L. Experimental data were successfully modelled using Langmuir (R2 ≥ 0.891) and Freundlich (R2 ≥ 0.990) i
The modified sample-standard bracketing method (m-SSB) combines a sample-standard bracketing and an inter-element correction procedure to account for instrumental mass fractionation during multi-collector ICP-MS measurements. Precisions for Cu and Zn isotopes in plant and experimental granite leachate samples are in line with those obtained using other mass bias correction techniques. In addition,
Intra-islet crosstalk has become a focus area to fully understand the regulation of insulin secretion and impaired β-cell function in type 2 diabetes (T2D). Here, we put forward evidence for insulin-like growth factor binding protein 7 (IGFBP7) as a potential protein involved in autocrine and paracrine β-cell regulation. We showed presence of IGFBP7 in granules of both human α- and β-cells and mea