Application of simulation and modelling in managing unplanned healthcare demand

Patients who attend Accident and Emergency (A & E) departments with problems that could be dealt with by their general practitioners (GPs) use time and resources of the department that could be otherwise used for patients with more appropriate needs. Hospital managers throughout the world are facing increasing pressure to introduce measures and initiatives to significantly ease the problem of such inappropriate attendances at A&E departments. This study looks at an initiative in which primary care clinicians are used to help deflect patients with non-urgent needs away from A&E. Simulation and modelling was used to assess the impact that this initiative would have on A&E workflow. The results suggest that the deflection of patients attending A&E with non-urgent needs may reduce the time spent in A&E by all patients attending A&E

Geometric, electronic properties and the thermodynamics of pure and Al--doped Li clusters

The first--principles density functional molecular dynamics simulations have been carried out to investigate the geometric, the electronic, and the finite temperature properties of pure Li clusters (Li$_{10}$, Li$_{12}$) and Al--doped Li clusters (Li$_{10}$Al, Li$_{10}$Al$_2$). We find that addition of two Al impurities in Li$_{10}$ results in a substantial structural change, while the addition of one Al impurity causes a rearrangement of atoms. Introduction of Al--impurities in Li$_{10}$ establishes a polar bond between Li and nearby Al atom(s), leading to a multicentered bonding, which weakens the Li--Li metallic bonds in the system. These weakened Li--Li bonds lead to a premelting feature to occur at lower temperatures in Al--doped clusters. In Li$_{10}$Al$_2$, Al atoms also form a weak covalent bond, resulting into their dimer like behavior. This causes Al atoms not to `melt' till 800 K, in contrast to the Li atoms which show a complete diffusive behavior above 400 K. Thus, although one Al impurity in Li$_{10}$ cluster does not change its melting characteristics significantly, two impurities results in `surface melting' of Li atoms whose motions are confined around Al dimer.Comment: 9 pages, 7 figure

The Efficiency and Performance Evaluation of Government-Linked Companies (GLCs) in Malaysia using Data Envelopment Analysis

Efficiency is a vital criterion in global competitive business and sustainable growth. Efficiency has always been reflected in company’s performance based on the existing input or resources available against the optimum output generated. A highly strong organizations capability will attract higher revenue and more investors to the company. The purpose of this study is to evaluate, compare and rank the overall efficiency based on annual report of companies in Malaysia stock market by using Data Envelopment Analysis (DEA). The analysis is carried out on 15 government-linked companies (GLCs) where cross-sectional data between periods of 2013 to 2017 were evaluated. Three efficiency input were considered including return on assets, return on equity and tobin’s q where the outcome or outputs were profitability. The results indicate the significance to the investors as the overall efficiency of the companies is ranked according to several years of reports using the DEA model. The implication of this research would benefit the organizations to perform better

Turbulent Combustion of Polydisperse Evaporating Sprays with Droplet Crossing: Eulerian Modeling and Validation in the Infinite Knudsen Limit

The accurate simulation of the dynamics of polydisperse evaporating sprays in unsteady gaseous flows with large-scale vortical structures is both a crucial issue for industrial applications and a challenge for modeling and scientific computing. The difficulties encountered by the usual Lagrangian approaches make the use of Eulerian models attractive, aiming at a lower cost and an easier coupling with the carrier gaseous phase. Among these models, the multi-fluid model allows for a detailed description of the polydispersity and size-velocity correlations for droplets of various sizes. The purpose of the present study is twofold. First, we extend the multi-fluid model in order to cope with crossing droplet trajectories by using the quadrature method of moments in velocity phase space conditioned by size. We identify the numerical difficulties and provide dedicated numerical schemes in order to preserve the velocity moment space. Second, we conduct a comparison study and demonstrate the capability of such an approach to capture the dynamics of an evaporating polydisperse spray in a 2-D free jet configuration. We evaluate the accuracy and computational cost of Eulerian models and related discretization schemes vs. Lagrangian solvers and show that, even for finite Stokes number, the standard Eulerian multi-fluid model can be accurate at reasonable cost

Subaqueous shrinkage cracks in the Sheepbed mudstone: Implications for early fluid diagenesis, Gale crater, Mars

The Sheepbed mudstone, Yellowknife Bay formation, Gale crater, represents an ancient lakebed now exhumed and exposed on the Martian surface. The mudstone has four diagenetic textures, including a suite of early diagenetic nodules, hollow nodules, and raised ridges and later diagenetic light-toned veins that crosscut those features. In this study, we describe the distribution and characteristics of the raised ridges, a network of short spindle-shaped cracks that crosscut bedding, do not form polygonal networks, and contain two to four layers of isopachous, erosion-resistant cement. The cracks have a clustered distribution within the Sheepbed member and transition laterally into concentrations of nodules and hollow nodules, suggesting that these features formed penecontemporaneously. Because of the erosion-resistant nature of the crack fills, their three-dimensional structure can be observed. Cracks that transition from subvertical to subhorizontal orientations suggest that the cracks formed within the sediment rather than at the surface. This observation and comparison to terrestrial analogs indicate that these are syneresis cracks—cracks that formed subaqueously. Syneresis cracks form by salinity changes that cause sediment contraction, mechanical shaking of sediment, or gas production within the sediment. Examination of diagenetic features within the Sheepbed mudstone favors a gas production mechanism, which has been shown to create a variety of diagenetic morphologies comparable to the raised ridges and hollow nodules. The crack morphology and the isopachous, layered cement fill show that the cracks were filled in the phreatic zone and that the Sheepbed mudstone remained fluid saturated after deposition and through early burial and lithification

Constraining the Texture and Composition of Pore-Filling Cements at Gale Crater, Mars

The Mars Science Laboratory (MSL) rover Curiosity has encountered a wide variety of sedimentary rocks deposited in fluvio-lacuestrine sequences at the base of Gale Crater. The presence of sedimentary rocks requires that initial sediments underwent diagenesis and were lithified. Lithification involves sediment compaction, cementation, and re-crystallization (or authigenic) processes. Analysis of the texture and composition of the cement can reveal the environmental conditions when the cements were deposited, enabling better understanding of early environments present within Gale Crater. The first step in lithification is sediment compaction. The Gale crater sediments do not show evidence for extensive compaction prior to cementation; the Sheepbed mudstone in Yellowknife Bay (YKB) has preserved void spaces ("hollow nodules"), indicating that sediments were cemented around the hollow prior to compaction, and conglomerates show imbrication, indicating minimal grain reorganization prior to lithification. Furthermore, assuming the maximum burial depth of these sediments is equivalent to the depth of Gale Crater, the sediments were never under more than 1 kb of pressure, and assuming a 15 C/km thermal gradient in the late Noachian, the maximum temperature of diagenesis would have been approximately 75 C. This is comparable to shallow burial diagenetic conditions on Earth. The cementation and recrystallization components of lithification are closely intertwined. Cementation describes the precipitation of minerals between grains from pore fluids, and recrystallization (or authigenesis) is when the original sedimentary mineral grains are altered into secondary minerals. The presence of authigenic smectites and magnetite in the YKB formation suggests that some recrystallization has taken place. The relatively high percentage of XRD-amorphous material (25-40%) detected by CheMin suggests that this recrystallization may be limited in scope, and therefore may not contribute significantly to the cementing material. However, relatively persistent amorphous components could exist in the Martian environment (e.g. amorphous MgSO4), so recrystallization, including loss of crystallinity, cannot yet be excluded as a method of cementation. In order to describe the rock cementation, both the rock textures and their composition must be considered. Here, we attempt to summarize the current understanding of the textural and compositional aspects of the cement across the rocks analyzed by Curiosity to this point

Nonstop mRNAs generate a ground state of mitochondrial gene expression noise

Funding Information: This work was supported by the Academy of Finland (307431 and 314706 to B.J.B.), the Sigrid Juselius Foundation Senior Investigator Award to B.J.B., and United Mitochondrial Disease Foundation (PI-16-0598 to B.J.B.) and donations from the Hereditary Neuropathy Foundation, Lindsey Flynt, and Medtronic to B.J.B.; the Orion Research Foundation and the Finnish Cultural Foundation to K.Y.N.; the Academy of Finland (321961 to U.R.); the Sigrid Juselius Foundation, the Academy of Finland (331556), and the Jane and Aatos Erkko Foundation to C.D.D.; Action Medical Research (GN2494 to W.G.N.) and the Manchester NIHR Biomedical Research Centre (IS-BRC-1215-20007 to W.G.N.); the Wellcome Centre for Mitochondrial Research (203105/Z/16/Z to R.W.T.), the Mitochondrial Disease Patient Cohort (UK) (G0800674 to R.W.T.), the Medical Research Council International Centre for Genomic Medicine in Neuromuscular Disease (MR/S005021/1 to R.W.T.), the Lily Foundation, the UK NIHR Biomedical Research Centre for Ageing and Age-related disease award to the Newcastle upon Tyne Foundation Hospitals NHS Trust, the Pathological Society, and the UK NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and Children to R.W.T.; Medical Research Council (MR/W019027/1 to W.G.N. and R.W.T.); the Academy of Finland (338836 and 314672 to V.O.P.); and the Sigrid Juselius Foundation and the Jane and Aatos Erkko Foundation. Publisher Copyright: Copyright © 2022 The Authors, some rights reserved;A stop codon within the mRNA facilitates coordinated termination of protein synthesis, releasing the nascent polypeptide from the ribosome. This essential step in gene expression is impeded with transcripts lacking a stop codon, generating nonstop ribosome complexes. Here, we use deep sequencing to investigate sources of nonstop mRNAs generated from the human mitochondrial genome. We identify diverse types of nonstop mRNAs on mitochondrial ribosomes that are resistant to translation termination by canonical release factors. Failure to resolve these aberrations by the mitochondrial release factor in rescue (MTRFR) imparts a negative regulatory effect on protein synthesis that is associated with human disease. Our findings reveal a source of underlying noise in mitochondrial gene expression and the importance of responsive ribosome quality control mechanisms for cell fitness and human health.Peer reviewe