In this paper, we consider a stochastic model in which the population grows according to the batch Markovian arrival process and is subjected to renewal generated geometric catastrophes. Our analytical work starts from the vector generating function (VGF) of the population size at post-catastrophe epoch. We develop a methodology for extracting the population size distribution at post-catastrophe epoch from the VGF, which is based on the inversion of VGF using the roots method. The method is analytically quite simple and easy to implement. Further, we obtain the population size distribution at arbitrary, pre-catastrophe and pre-arrival epochs along with their factorial moments. To show the applicability and correctness of the proposed methodology, we match our results with the available ones in special cases and present several numerical examples for different inter-catastrophe time distributions. Moreover, we investigate the effect of key parameters on the system performance and display the results in the form of graphs along with a detailed description.
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http://dx.doi.org/10.1007/s40819-021-01112-4 | DOI Listing |
J Nephrol
January 2025
Department of Nephrology, Matsunami General Hospital, Gifu, Japan.
Background: The relationship between the psoas muscle gauge (PMG), a combined sarcopenia indicator obtained from psoas muscle index (PMI) and psoas muscle density (PMD), and adverse clinical outcomes in patients on hemodialysis remains unclear. We examined whether psoas muscle gauge could predict all-cause mortality and new cardiovascular events more accurately than psoas muscle index in these patients.
Methods: We retrospectively included 217 hemodialysis patients who underwent abdominal computed tomography.
Exp Appl Acarol
January 2025
Manaaki Whenua - Landcare Research, 231 Morrin Road, Auckland, 1072, New Zealand.
The balance between mating benefits and costs shapes reproductive strategies and life history traits across animal species. For biological control programs, understanding how mating rates influence life history traits is essential for optimising population management and enhancing predator efficacy. This study investigates the impact of mating opportunity availability, delayed mating, and male mating history (copulation frequency) on the lifespan (both sexes), female reproductive traits (duration of oviposition and of pre- and post-oviposition periods, and lifetime oviposition), and offspring quality (egg size and offspring survival) of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), an important biological control agent against spider mites.
View Article and Find Full Text PDFNutr Rev
January 2025
Department of Emergency Medicine, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan 64600, China.
Context: Previous studies have explored the relationship between vitamin D and lipid profile in individuals with obesity or overweight women, but the results have been inconsistent.
Objective: This meta-analysis and systematic review of randomized controlled trials (RCTs) was conducted to assess the effect of vitamin D on lipid profile in women who are overweight or obese.
Data Sources: A meticulous search strategy was used across the Scopus, PubMed/Medline, Web of Science, and Embase databases up to June 2024.
J Phys Chem A
January 2025
Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
Symmetry breaking is ubiquitous in chemical transformations and affects various physicochemical properties of materials and molecules; Jahn-Teller (JT) distortion of hexa-coordinated transition-metal-ligand complexes falls within this paradigm. An uneven occupancy of degenerate 3d-orbitals forces the complex to adopt an axially elongated or compressed geometry, lowering the symmetry of the system and lifting the degeneracy. Coordination complexes of Cu are known to exhibit axial elongation, while compression is far less common, although this may be due to the lack of rigorous experimental verification.
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
Division of Analytical Chemistry and Environmental Geochemistry, Institute of Chemistry, Jan Kochanowski University, Kielce, Poland.
Occurrence of microplastics in the environment is well studied, but our knowledge of their distribution in specific locations, such as the sandboxes, which are integral parts of popular playgrounds for children, is limited. Pioneering research on the factors affecting the microplastic pollution of sandboxes in urban residential areas was conducted within three estates in Kielce, Poland. Sand samples (Σ27) were collected from nine sandboxes and examined for the presence of microplastics, using a simple quality control methodology proposed by the authors.
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