18624 research outputs found
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Number theoretic subsets of the real line of full or null measure
Full text linkDuring a first or second course in number theory, students soon encounter several sets of “number theoretic interest”. These include basic sets such as the rational numbers, algebraic numbers, transcendental numbers, and Liouville numbers, as well as more exotic sets such as the constructible numbers, normal numbers, computable numbers, badly approximable numbers, the Mahler sets S, T and U, and sets of irrationality exponent m, among others. Those exposed to some measure theory soon make a curious observation regarding a common property seemingly shared by all these sets: each of the sets has Lebesgue measure equal to zero, or its complement has Lebesgue measure equal to zero. In this expository note, we explain this phenomenon. © 2025 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0
Optimized random forest models for rock mass classification in tunnel construction
Full text linkThe accurate prediction of rock mass quality ahead of the tunnel face is crucial for optimizing tunnel construction strategies, enhancing safety, and reducing geological risks. This study developed three hybrid models using random forest (RF) optimized by moth-flame optimization (MFO), gray wolf optimizer (GWO), and Bayesian optimization (BO) algorithms to classify the surrounding rock in real time during tunnel boring machine (TBM) operations. A dataset with 544 TBM tunneling samples included key parameters such as thrust force per cutter (TFC), revolutions per minute (RPM), penetration rate (PR), advance rate (AR), penetration per revolution (PRev), and field penetration index (FPI), with rock classification based on the Rock Mass Rating (RMR) method. To address the class imbalance, the Borderline Synthetic Minority Over-Sampling Technique was applied. Performance assessments revealed the MFO-RF model’s superior performance, with training and testing accuracies of 0.992 and 0.927, respectively, and key predictors identified as PR, AR, and RPM. Additional validation using 91 data sets confirmed the reliability of the MFO-RF model on unseen data, achieving an accuracy of 0.879. A graphical user interface was also developed, enabling field engineers and technicians to make instant and reliable rock classification predictions, greatly supporting safe tunnel construction and operational efficiency. These models contribute valuable tools for real-time, data-driven decision-making in tunneling projects. © 2025 by the authors
Systemic brain dissemination of glioblastoma requires transdifferentiation into endothelial-like cells via TGF-
Full text linkGlioblastoma is the most aggressive type of brain cancer, but treatment improvements for glioblastoma patients remain stagnated for over 20 years. This is despite the large number of clinical trials that have attempted to replicate the success of therapeutics developed for other cancer types. This discrepancy highlights the urgent need to decipher the unique biology of glioblastomas. Here, we show that glioblastoma tumour cells are highly plastic, integrating into blood vessel walls to disseminate throughout the brain. This relies on the transdifferentiation of glioblastoma tumor cells into endothelial-like cells in a process we termed endothelialisation. Mechanistically, in addition to TGF
Bohr compactification of separable locally convex spaces
Full text linkIt is not well-known that for each separable real locally convex space, its Bohr compactification is isomorphic as a topological group to the Bohr compactification of the topological group R of all real numbers. This is the case for each separable real Banach space. In this expository research note, we state the results explicitly and provide accessible proofs. © 2025 the Author(s). All rights reserved
Low and medium voltage distribution network planning with distributed energy resources : a survey
Full text linkAbstract: The penetration of distributed energy resources (DERs) such as photovoltaic systems, energy storage systems, and electric vehicles is increasing in the distribution system. The distinct characteristics of these resources, e.g., volatility and intermittency, introduce complexity in operation and planning of the distribution system. This paper first summarized the physical characteristics and morphological evaluation of the current and future distribution networks. Then, the impact of these changes on system operation and planning is outlined. Next, the tools, methods, and techniques for energy forecasting, optimal planning, and distribution system state estimation are reviewed and discussed, along with the challenges. As the main contributions, this research systematically organized the published works and assessed the relevant milestones regarding distribution system planning with DERs and emerging technologies. Finally, the key research directions in this domain are outlined. © The Author(s) 2024
Recent progress in CRISPR/Cas9 system for eye disorders
No full textOcular disorders encompass a broad spectrum of phenotypic and clinical symptoms resulting from several genetic variants and environmental factors. The unique anatomy and physiology of the eye facilitate validation of cutting-edge gene editing treatments. Genome editing developments have allowed researchers to treat a variety of diseases, including ocular disorders. The clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) system holds considerable promise for therapeutic applications in the field of ophthalmology, including repair of aberrant genes and treatment of retinal illnesses related to the genome or epigenome. Application of CRISPR/Cas9 systems to the study of ocular disease and visual sciences have yielded innovations including correction of harmful mutations in patient-derived cells and gene modifications in several mammalian models of eye development and disease. In this study, we discuss the generation of several ocular disease models in mammalian cell lines and in vivo systems using a CRISPR/Cas9 system. We also provide an overview of current uses of CRISPR/Cas9 technologies for the treatment of ocular pathologies, as well as future challenges. © 202
Investigating falls risk awareness in hospitals using the Self-Awareness of Falls Risk Measure (SAFRM) : empirical research quantitative
Full text linkAim: The overarching aim of this study was to explore patients' falls risk awareness in hospitals using section A of the validated Self Awareness of Falls Risk Measure (SAFRM). Design: Descriptive cross-sectional study design. Setting: Three rural/regional hospitals in the State of Victoria, Australia. Methods: Using a purposive sampling strategy, patients were eligible to participate if age
Advances in applications of the CRISPR/Cas9 system for respiratory diseases
No full textGenetic and environmental factors can have an impact on lung and respiratory disorders which are associated with severe symptoms and have high mortality rates. Many respiratory diseases are significantly influenced by genetic or epigenetic factors. Gene therapy offers a powerful approach providing therapeutic treatment for lung diseases. Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (CRISPR/Cas9) are promising gene modifying tool that can edit the genome. The utilization of CRISPR/Cas9 systems in the investigation of respiratory disorders has resulted in advancements such as the rectification of deleterious mutations in patient-derived cells and the alteration of genes in multiple mammalian lung disease models. New avenues of treatment for lung disorders have been opened up by advances in CRISPR/Cas9 research. In this chapter, we discuss the known genes and mutations that cause several common respiratory disorders such as COPD, asthma, IPF, and ARDS. We further review the current research using CRISPR/Cas9 in numerous respiratory disorders and possible therapeutic treatments. © 202
Lean tools in higher educational institutions and their impact on operational performance : a scoping review
No full textPurpose: The study aims to summarise the major Lean tools used in higher education institutions (HEIs) and their impact on different operational performances. Design/methodology/approach: A scoping review was conducted to achieve this objective, systematically identifying and synthesizing relevant literature on Lean tools in HEIs, employing the PRISMA methodology for structured analysis. Journal papers from 2000 - 2024 were reviewed, focusing on peer-reviewed journals indexed in Scopus. The screening process yielded a final set of 23 acceptable studies for further analysis, considering only English-language articles and reviews focused on the adoption of Lean tools in higher education processes and their associated benefits. Findings: Lean tools in HEIs enhance the operational performance by streamlining processes and resulting in improved service quality, increased overall efficiency and effectiveness in both academic and administrative operations. Value stream mapping (VSM) emerges as the most important technique, followed by 5S and Kaizen to foster a culture of continuous improvement. Theoretical implications: The research contributes to the development of theory by providing an understanding of the use of lean tools and principles in the specific sector of higher education institutions and highlighting where the gaps lie in current theory about the use of these same tools in higher education. This prompted us to create new theoretical structures to achieve operational excellence in areas such as office work, academic teaching methods, student support and building maintenance at colleges and universities. Practical implications: The benefits of using Lean tools are not only evident in key performance indicators, but also in areas such as teaching processes and the improvement of administrative processes through knowledge sharing, which enables continuous improvement and a change in the culture of quality education. Originality: The study critically examines and categorize the Lean tools that are most relevant and applicable within the unique context of HEIs. By focusing on this sector, we address a gap in the literature, as Lean implementation has been relatively understudied compared to other methodologies and other sectors (i.e., manufacturing or service industries). To the best of our knowledge, this is the first study to categorize the Lean tools adopted in HEIs, the processes in which they have been implemented, and the benefits derived from their adoption, from an operational excellence perspective
The role of public events as a tool for economic recovery in an urban environment
Full text linkThis study investigates the effects of events in the New Zealand city of Christchurch’s Central Business District (CBD) on pedestrian movements over the period from 2018 to 2020. Christchurch represents an ideal example of how contemporary urban design and marketing techniques can be combined to attract people to places that have been negatively affected by a natural disaster. Events played an integral part of the regeneration efforts to attract pedestrians and support economic recovery. Through analysing hourly pedestrian movements in the rebuilt and revitalised parts of the city, results show that public events contribute positively to pedestrian volumes; however, the result is not statistically significant. Common cause, rather than entertainment events, draw larger pedestrian volumes, reflecting a stronger preference for events that contribute to social coherence after the disruptive event. Pedestrian visitations during the summer months, holidays, and from Thursday to Saturday have a positive effect on pedestrian volume and even non-event days draw pedestrians to the CBD, a likely result from the regeneration narrative and personal experience associated with the renewed CBD. This research shows how the importance of temporal effects challenges the role of events as a stand-alone tool designed to drive economic recovery within a revitalised urban environment. © 2025 by the authors