We describe a novel conservative algorithm for parabolic problems in domains with moving boundaries developed for modeling in cell biology. The spatial discretization is accomplished by applying Voronoi decomposition to a fixed rectangular grid. In the vicinity of the boundary, the procedure generates irregular Voronoi cells that conform to the domain shape and merge seamlessly with regular control volumes in the domain interior. Consequently, our algorithm is free of the CFL stability issue due to moving interfaces and does not involve cell-merging or mass redistribution. Local mass conservation is ensured by finite-volume discretization and natural-neighbor interpolation. Numerical experiments with two-dimensional geometries demonstrate exact mass conservation and indicate an order of convergence in space between one and two. The use of standard meshing techniques makes extension of the method to three dimensions conceptually straightforward.
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http://dx.doi.org/10.1016/j.jcp.2014.03.014 | DOI Listing |
Rehabilitacion (Madr)
January 2025
Servicio de Medicina Física y Rehabilitación, Hospital Universitario Miguel Servet, Zaragoza, España.
Osteoarthritis is a major health problem due to its high prevalence. It is a very common cause of consultation in both primary care and hospitals, implying a high care burden and health costs. Current treatment recommendations are based on a conservative approach, based mainly on physical exercise and ultimately on prosthetic surgery.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Mathematics, University of Maryland, College Park, Maryland, United States of America.
1. Analysis of co-occurrence data with traditional indices has led to many problems such as sensitivity of the indices to prevalence and the same value representing either a strong positive or strong negative association across different datasets. In our recent study (Mainali et al 2022), we revealed the source of the problems that make the traditional indices fundamentally flawed and unreliable-namely that the indices in common use have no target of estimation quantifying degree of association in the non-null case-and we further developed a novel parameter of association, alpha, with complete formulation of the null distribution for estimating the mechanism of affinity.
View Article and Find Full Text PDFSoil moisture is a key parameter for the exchange of substance and energy at the land-air interface, timely and accurate acquisition of soil moisture is of great significance for drought monitoring, water resource management, and crop yield estimation. Synthetic aperture radar (SAR) is sensitive to soil moisture, but the effects of vegetation on SAR signals poses challenges for soil moisture retrieval in areas covered with vegetation. In this study, based on Sentinel-1 SAR and Sentinel-2 optical remote sensing data, a coupling approach was employed to retrieval surface soil moisture over dense vegetated areas.
View Article and Find Full Text PDFThe species, valued for their pharmaceutical, ornamental, and economic importance, exhibit notable rarity and endemism in the Karst areas of the Yunnan-Kweichow Plateau in China. These species face significant threats from habitat loss and fragmentation, leading to a decline in biodiversity. To mitigate these threats, the Maxent algorithm was employed to analyze current and future distribution patterns, with a particular focus on the influence of climate variables in predicting potential distribution shifts and assessing extinction risks under the optimistic SSP1-2.
View Article and Find Full Text PDFRev Med Suisse
January 2025
Service de chirurgie viscérale, Département de chirurgie, Centre hospitalier universitaire vaudois, 1011 Lausanne.
This article highlights some advances in visceral surgery in 2024. In the hepato-pancreato-biliary field, liquid biopsies, immunotherapy, and robotics have revolutionized diagnosis and treatment, while artificial intelligence could enhance planning and operational safety. In endocrine surgery, a more conservative approach is recommended for well-differentiated thyroid cancers.
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