85000 research outputs found
Sort by
Microplastic distribution and ecological risks: investigating road dust and stormwater runoff across land uses
No full textRoad dust and stormwater runoff are significant pathways for transporting microplastics (MPs) from land-based sources to the surrounding ecological compartments. The aim of this study is to understand the occurrence of MPs in both road dust and stormwater samples collected under various land uses, including residential, commercial and industrial areas, within Melbourne metropolitan city, Australia. This study also evaluated the ecological risk indices of MP polymers under different land uses. MP emission characteristics and loads (number- and mass-based) were estimated to investigate pollution risks. Higher quantities of MPs were detected in road dust and stormwater in industrial areas (2410 items per kg and 35 items per L) than in commercial (2130 items per kg and 27 items per L) and residential (1970 items per kg and 24 items per L) areas. Mass loads of MPs were also higher in industrial regions in road dust and stormwater samples. It was found that 200 μm to 2450 μm sized MPs were abundant in road dust, which was higher than the sizes of stormwater MPs (125 μm to 960 μm). The water forces in the drainage system could be the reason for the breakdown of larger MPs. Fragments and fibers were the dominant shapes of MPs in all the selected areas. Fourier transform infrared spectroscopy of representative samples identified several types of polymers, predominantly polypropylene, polyethylene, polyethylene terephthalate/polyester, polyvinyl chloride and polyethylene. The hazard index indicates that the ecological risks of MPs are higher in industrial areas than in other areas. This study revealed that MP emission via road dust was significantly higher due to traffic and industrial and human activities. This study has demonstrated that stormwater runoff is the primary corridor for transporting MPs from road dust to the aquatic environment of wetlands
Development of a glass-based imaging phantom to model the optical properties of human tissue
No full textThe fabrication of a stable, reproducible optical imaging phantom is critical to the assessment and optimization of optical imaging systems. We demonstrate the use of an alternative material, glass, for the development of tissue-mimicking phantoms. The glass matrix was doped with nickel ions to approximate the absorption of hemoglobin. Scattering levels representative of human tissue were induced in the glass matrix through controlled crystallization at elevated temperatures. We show that this type of glass is a viable material for creating tissue-mimicking optical phantoms by providing controlled levels of scattering and absorption with excellent optical homogeneity, long-term stability and reproducibility
A Wearable Sonification System to Improve Movement Awareness: A Feasibility Study
No full textThis paper presents the design, development, and feasibility testing of a wearable sonification system for real-time posture monitoring and feedback. The system utilizes inexpensive motion sensors integrated into a compact, wearable package to measure body movements and standing balance continuously. The sensor data is processed through sonification algorithms to generate real-time auditory feedback cues indicating the user’s balance and posture. The system aims to improve movement awareness and physical conditioning, with potential applications in balance rehabilitation and physical therapy. Initial feasibility testing was conducted with a small group of healthy participants performing standing balance tasks with eyes open and closed. Results indicate that the real-time audio feedback improved participants’ ability to maintain balance, especially in the case of closed eyes. This preliminary study demonstrates the potential for wearable sonification systems to provide intuitive real-time feedback on posture and movement to improve motor skills and balance
Monopoly dynamics and the rise of UK single-family rental
No full textThis article offers an early account of the emergent UK single family rental market, which it argues represents a potential locus for monopoly dynamics within the UK rental sector. Conceptually, this article positions single family rental (SFR) within the rise of the ‘beds sector’ and within Brett Christophers’ asset manager society. This article further engages with total life landlordism, which theorises the asset manager practice of mopping up opportunities across the beds sector that progresses towards the cradle-to-grave entrapment of households in a corporate rental system, beholden to asset management efforts to maximise asset disposal considerations. Stakeholder interview analysis highlights: investor/housebuilders synergies; crossover of institutional investors from build to rent (multifamily), another beds subsector; and common ground with US SFR despite otherwise divergent transatlantic SFR genealogies and timelines. Focusing on monopoly intermediation, as the primary logic of total life landlordism, this article highlights early signs of competition dynamics at play within and through this new SFR market, including monopoly power and class monopoly rents. It underscores monopoly dynamics as an important feature of the asset manager society
Damage mechanism and assessment of precast double-column bridge piers under blast impact
No full textThis paper aims to investigate the damage mechanism of precast double-column bridge piers under blast impact and propose a new damage evaluation method. The three-dimensional solid separation model of a pier column under explosion actions is established using ANSYS/LS-DYNA, and the accuracy of the numerical simulation method is verified by the existing experimental results. Subsequently, numerical experiments of the double-column bridge piers under explosions are carried out. The damage accumulation process and local failure mechanism are investigated with the analyses of the propagation of stress waves in concrete. In addition, the criteria containing residual bearing capacity and local damage are introduced in the damage assessment, aiming to evaluate the explosion damage degree of bridge piers comprehensively. The P-I (pressure-impulse) curves of precast double-column piers are established, based on the overpressure-impulse damage assessment method by Henrych's empirical formula. The general evaluation process and method of double-column bridge piers under blast impacts are proposed and verified. The research results provide important insights and references for the anti-blast design of precast double-column piers and their bridge systems
Mean-field reinforcement learning for decentralized task offloading in vehicular edge computing
No full textVehicular Edge Computing (VEC) is a promising paradigm for providing low-latency and high-reliability services in the Internet of Vehicles (IoV). The increasing number of mobile devices and the diverse resource requirements of the growing IoV have resulted in a shift from centralized resource management to a decentralized approach. This shift offers improved fault tolerance, scalability, and privacy preservation. However, constructing collaborative awareness and coordination mechanisms between multiple vehicles and edge nodes in a decentralized manner is a challenge. To address this issue, we propose a decentralized many-to-many task offloading method that aims to minimize the average task completion latency of vehicles. In this study, we propose a data-sharing mechanism between vehicles and edge servers using the digital twin service, which provides global environmental perceptions to the vehicles by a low-cost approach. Additionally, we develop a mean-field multi-agent reinforcement learning algorithm to generate coordinated task offloading schemes. Instead of interacting with multiple agents, the vehicle only needs to respond to the mean action of the environment. Based on this transition, the agent generates coordinated task offloading decisions in complex scenarios. We evaluate the performance of our method using real urban traffic data. Experiment results verify the efficiency of our proposed method
Biofilm Formation in Campylobacter concisus: The Role of the luxS Gene
No full textCampylobacter concisus is a bacterium that inhabits human oral cavities and is an emerging intestinal tract pathogen known to be a biofilm producer and one of the bacterial species found in dental plaque. In this study, biofilms of oral and intestinal C. concisus isolates were phenotypically characterized. The role of the luxS gene, which is linked to the regulation of biofilm formation in other pathogens, was assessed in relation to the pathogenic potential of this bacterium. Biofilm formation capacity was assessed using phenotypic assays. Oral strains were shown to be the highest producers. A luxS mutant was created by inserting a kanamycin cassette within the luxS gene of the highest biofilm-forming isolate. The loss of the polar flagellum was observed with scanning and transmission electron microscopy (SEM and TEM). Furthermore, the luxS mutant exhibited a significant reduction (p < 0.05) in biofilm formation, motility, and its expression of flaB, in addition to the capability to invade intestinal epithelial cells, compared to the parental strain. The study concluded that C. concisus oral isolates are significantly higher biofilm producers than the intestinal isolates and that LuxS plays a role in biofilm formation, invasion, and motility in this bacterium
A Review of the Ethnobotanical Use, Chemistry and Pharmacological Activities of Constituents Derived from the Plant Genus Geijera (Rutaceae)
No full textGeijera Schott is a plant genus of the Rutaceae Juss. (rue and citrus) family, comprising six species which are all native to Oceania. Of the plants belonging to this genus, the most significant species that has a customary use is Geijera parviflora, which was used by Indigenous Australians, primarily as a pain reliever. Herein, a comprehensive review of the literature published on the genus Geijera from 1930 to 2023 was conducted. This is the first review for this plant genus, and it highlights the chemical constituents reported to date, together with the range of pharmacological properties described from the various species and different parts of the plant. These properties include anti-inflammatory, anti-microbial, anti-parasitic, insect repellent, analgesic, neuroactive, and anti-cancer activities. Finally, a reflection on some of the important areas for future focused studies of this plant genus is provided
Foreign market exit in family firms: Do historical military and cultural frictions matter?
No full textIn a fast-changing world, strategic decisions to exit a foreign market become more complex for family firms, owing to their vulnerability to uncertainty in internationalization. However, there is scant research on family firms’ foreign market exit with respect to their responses to contextual influences from home and host countries. This study reconciles the socioemotional wealth (SEW) perspective and the friction lens to address this gap. Using a sample of 1,455 subsidiaries established by 413 Chinese family firms in 2009-2018, we find that historical military friction increases family firms’ foreign market exit, while cultural friction leads to a lower exit propensity. We also find that family management reinforces the friction-exit relationships, and this effect is strengthened when the family firm is controlled by the first generation. Our theory and related findings deepen our understanding of the foreign market exit decision of family firms while offering important theoretical and managerial implications
Nanozyme-enhanced paper-based biosensor technologies
No full textNanozymes, enzyme-mimetic nanomaterials that combine features of nanoscale material with the catalytic properties of enzymes, have undergone rapid development in recent years. While enzymes have remained integral to biosensor technologies for the past several decades, the emerging potential of nanozymes to overcome the low stability and high production costs of biological enzymes has turned them into promising biosensor candidates. Nanozymes have already been explored for a myriad of biosensing applications. However, only a small subset of these efforts has resulted in devices and platforms that are potentially suitable for on-site/point-of-care monitoring. To promote efforts in this area, the review first provides a concise overview of different paper-based technologies, their architecture and functionality, in a language conducive to the nanozyme research community. The review, then, critically discusses the progress made in the integration of nanozymes in biosensor platforms for on-site detection of food contaminants, environmental pollutants, and disease biomarkers. The challenges associated with the transition of solution-based nanozyme biosensors to relevant devices and technologies are highlighted, and strategies to overcome those challenges are proposed. We envision that this review could narrow the gap impeding the translation of nanozyme-based biosensor technologies from laboratories to real-world scenarios by encouraging consolidated cross-disciplinary and trans-sectoral efforts