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Modelling midline shift and ventricle collapse in cerebral oedema following acute ischaemic stroke
Get PDFIn ischaemic stroke, a large reduction in blood supply can lead to the breakdown of the blood-brain barrier and to cerebral oedema after reperfusion therapy. The resulting fluid accumulation in the brain may contribute to a significant rise in intracranial pressure (ICP) and tissue deformation. Changes in the level of ICP are essential for clinical decision-making and therapeutic strategies. However, the measurement of ICP is constrained by clinical techniques and obtaining the exact values of the ICP has proven challenging. In this study, we propose the first computational model for the simulation of cerebral oedema following acute ischaemic stroke for the investigation of ICP and midline shift (MLS) relationship. The model consists of three components for the simulation of healthy blood flow, occluded blood flow and oedema, respectively. The healthy and occluded blood flow components are utilized to obtain oedema core geometry and then imported into the oedema model for the simulation of oedema growth. The simulation results of the model are compared with clinical data from 97 traumatic brain injury patients for the validation of major model parameters. Midline shift has been widely used for the diagnosis, clinical decision-making, and prognosis of oedema patients. Therefore, we focus on quantifying the relationship between ICP and midline shift (MLS) and identify the factors that can affect the ICP-MLS relationship. Three major factors are investigated, including the brain geometry, blood-brain barrier damage severity and the types of oedema (including rare types of oedema). Meanwhile, the two major types (stress and tension/compression) of mechanical brain damage are also presented and the differences in the stress, tension, and compression between the intraparenchymal and periventricular regions are discussed. This work helps to predict ICP precisely and therefore provides improved clinical guidance for the treatment of brain oedema.European Union’s Horizon 2020 research and innovation program (Grant No. 777072, INSIST project, INSIST – IN Silico clinical trials for Ischemic STroke to TIJ (insist-h2020.eu, between 2018 and 2022)).PLoS Computational Biolog
The thousand faces of beauty: How credible storytelling unlocks disability representation in inclusive luxury fashion branding
No full textThe increasing popularity of inclusive marketing as part of the broader strategies of brand activism, linked to the diversity, equity and inclusion (DEI) movement, is creating new opportunities for luxury fashion brands to signal their responsibility and openness when it comes to these issues. However, such inclusivity initiatives can lead to consumer backlash when luxury brands rely on perfectionism and self-esteem to elicit admiration and desirability. We ask whether weaving models with disabilities into brand narratives contributes to positive consumer responses. Using signaling theory, our study employs a structural equation modeling approach to show that, despite the negative effect of perceived brand inclusivity on consumers’ willingness to buy, the serial mediation by transportation into brand stories and advertising credibility flips the effect to positive. By doing so, this study also extends extant literature on inclusive advertising in luxury fashion by going beyond dominant manifestations of inclusivity tackling feminism and LGBTQAI + rights
Evaluation of extreme value predictions for unsteady flow distortion of aero-engine intakes
Get PDFUnsteady flow distortion is of interest for the development air-breathing propulsion systems. These stochastic fluctuations can generate incompatibilities between intakes and aero-engines. Observing the extreme flow distortion events during experimental testing is not guaranteed and statistical models such as Extreme Value Theory (EVT) can be used to estimate the occurrence and magnitude of the fluctuations. However, the current industry standard does not provide guidance on how to apply these methods to obtain useful predictions. This work proposes a systematic process to assess the required number of observations for obtaining statistical convergence of the EVT predictions. This is achieved through shuffling of the data samples and relies on the availability of a sufficiently large initial dataset. This can be adopted by gas turbine engineers to evaluate the data recording requirements and to potentially reduce costs associated with experimental programs.UKRI [grant reference no. 2202953]Journal of Engineering for Gas Turbines and Powe
Responses of natural microorganisms to land reclamation and applications of functional microorganisms in biorestoration of coal mining area
Get PDFExtensive coal mining causes significant ecological and environmental impacts on the local ecosystem, especially on the terrestrial ecosystem. Mining activities induce the degradation of topsoil physico–chemical characteristics and the succession of soil microbial communities. The soil microbial community is sensitive to soil disturbance and restoration practices, being significant in soil reconstruction and land restoration. Microbes could be effective instruments to restore or reclaim disturbed terrestrial ecosystems and indispensable, unambiguous, indicators to assess reclaimed soils. In the present review, we aimed to provide insight into the effects of mining and subsequent land reclamation on soil microorganisms and the importance and application of microorganisms in the reclamation process. We address changes in the diversity and structure of the soil microbial community after reclamation and discuss the main driving factors of the community. We hypothesize that there is a discernible pattern or regularity in the variation of microbial community composition during the process of restoration succession. By employing the life strategy concept, the study attempts to identify and understand how microbial communities evolve during land reclamation. Land reclamation could improve the nutrients in the soil while increasing the proportion of saprotrophic microorganisms. In community succession, vegetation, soil properties, and reclamation time are key determining factors. Whereas bacteria, fungi, and archaea showed different responses to these factors, as they responded differently to varied soil environments, nutrition, and plants, and occupied different biological niches. Finally, we describe the applications of microorganisms as land reclamation monitors or promoters. This knowledge and understanding can provide comprehensive insight into the soil health condition and strong support for forecasting and decision-making in mine land restoration.Diversit
Sources of error in digital forensics
Get PDFThe occurrence of errors in forensic practice is inevitable, and whilst we may not feel comfortable with the idea, the truth of it must be acknowledged. At a time where forensic science is under intense scrutiny regarding the quality of its work, there has never been a greater need for it. In relation to the field of digital forensics (DF), the support it offers law enforcement is fundamental to many of its inquiries, and ensuring the reliability and accuracy of its services is vital. Errors in forensic practice can have far-reaching consequences for all those involved in an investigation, and practitioners and their organisations must take steps to identify, mitigate and manage them. This work focuses on the concept of error in relation to the field of DF. It first explores what an error is and the language used to describe one before mapping potential sources of error against the stages of the DF investigative process. This is done to assist those in the DF field to identify error sources, what they are and where they come from, and to facilitate the attribution of errors to a source, helping them to address them effectively.Forensic Science International: Digital Investigatio
How to enable ambidexterity in safety-critical software development
Get PDFIn a competitive environment, continually improving new products and services requires new knowledge and novel solutions. Managing projects also requires the careful control of resources for effective delivery. Ambidexterity, the simultaneous achievement of novelty through exploration and efficiency through exploitation, is challenging to achieve in practice. The ways in which companies can achieve ambidexterity are context dependent. It is especially hard to promote new and uncertain concepts in situations where lives are at stake. This article reports on a case study of a safety-critical IT development project that successfully achieved ambidexterity. Leadership behaviors that support ambidexterity in this setting are critical. We highlight four leadership behaviors key to developing an environment where creative solutions can flourish
Evaluation of the influence of dissolved nitrates on corrosion behaviour of ship structural steel exposed to seawater environment
Get PDFCorrosion rates in marine structural steels differ significantly with the varying compositions of seawater particularly near harbours or coastal regions primarily due to the presence of untreated chemically active species from various sources. The reviewed literature reports accelerated steel corrosion losses in coastal seawater exposure conditions, which has widely been attributed to the presence of aggressive chemical compounds e.g., dissolved inorganic nitrogenous (DINs) compounds, sulphur containing compounds, in combination with various other environmental factors and their interdependent complex relationships. This paper aims to investigate the influence of nitrates, a DIN compound, on the corrosion behaviour of a low carbon ship structural steel, by exposing surface the cleaned coupons to an artificial seawater solution in a controlled laboratory environment. The uniform and localised corrosion damages were measured on steel coupons by using the standard weight loss and the dimensional metrology methods. A significant increase in corrosion losses was observed on coupons exposed to the nitrate-added artificial seawater than those exposed to similar seawater compositions with no additional nitrate content. Elemental compositions of corrosion deposits and corrosion morphologies investigated using various analytical tools such as SEM, EDS and Raman scattering techniques have shown different types of corrosion products in both exposure conditions.Ocean Engineerin
High-order hybrid DG-FV framework for compressible multi-fluid problems on unstructured meshes
No full textIn this work we extend the hybrid Discontinuous Galerkin/ Finite Volume framework, introduced in V. Maltsev, D. Yuan, K. W. Jenkins, M. Skote, P. Tsoutsanis, “Hybrid discontinuous Galerkin-finite volume techniques for compressible flows on unstructured meshes, Journal of Computational Physics 473 (2023)” [1], to multi-species problems involving gas-gas and gas-liquid systems. The numerical scheme achieves high order accuracy in smooth flow regions thanks to the DG discretisation, yet avoiding oscillations at material interfaces and shocks thanks to a FV type reconstruction. This strategy, as typically represented in literature, makes use of the so-called troubled cell indicators for the detection of numerical oscillations generated by an unlimited high-order scheme in presence of discontinuities, and enables a more dissipative scheme in the troubled cells only in order to suppress the spurious oscillations. As will be shown in a series of increasingly challenging test-cases, when applied to multi-species flows in the context of diffuse-interface models, the hybrid framework is able to limit the excessive material interface dissipation, characteristic of these interface-capturing methods, allowing at the same time a control over the amount of dissipation necessary to solve stiffer problems.Journal of Computational Physic
Improving 2D resolution in geosynchronous SAR via spatial spectrum synthesis: method and verification
Get PDFGeosynchronous synthetic aperture radar (GEO SAR) has the advantages of a short revisit time and a large beam footprint. Enhancing spatial resolution has become a hotspot in spaceborne SAR research areas. The existing designs of GEO SAR suffer from the problem of poor resolution (greater than 10 m) and cause low-precision observation in urban areas. First time, this article points out that GEO SAR has the ability to improve the two-dimensional (2-D) resolution of SAR images by spatial spectrum synthesis based on 2-D baselines, and proposes models and a signal processing method involved in GEO SAR spectrum synthesis. The 2-D spatial baselines of GEO SAR are analyzed and evaluated first based on satellite software and real ephemeris from Beidou Inclined Geosynchronous Orbit (IGSO) navigation satellites to demonstrate the potential of 2-D resolution improvement. Then the analytical models of the spectral shape and relative spectral shift between GEO SAR images are derived. Furthermore, a 2-D spectrum synthesis algorithm suitable for GEO SAR is also proposed, where we use deramping operation instead of the traditional spectrum shifting process. Nonideal factors are considered in the processing of synthesized. In addition, performances of the proposed algorithm, including the resolution improvement factor, the amplitude fluctuation, and the critical baseline, are constructed. Finally, computer simulations and equivalent experiments based on Beidou IGSO navigation satellites verify the proposed algorithm.IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensin
Processes and mechanisms in remediation of aqueous chromium contamination by sulfidated nano-scale zerovalent iron (S-nZVI): experimental and computational investigations
Get PDFSulfidated nano-scale zerovalent iron (S-nZVI) has emerged as an advanced functional nanomaterial for efficiently remediating Cr(VI) contamination in aqueous environments. However, there is an insufficient understanding of its coherent process, removal pathway, and hydrochemical reactive mechanisms, presenting potential challenges for its future environmental applications. To address this gap, this study successfully synthesized S-nZVI through a chemical precipitation method and effectively applied it for the removal of Cr(VI). Additional characterization revealed that the removal of Cr(VI) followed a sequence of rapid chemisorption and intraparticle diffusion processes, concomitant with an increase in pH and a decrease in oxidation-reduction potential. The remediation mechanism encompassed a synergistic reduction of Cr(VI) to Cr(III) and simultaneous immobilization via Cr2FeO4 coprecipitation. The highest Cr(VI) removal capacity of 75 mg/g was attained during dynamic removal experiments in the sand column packed with S-nZVI. Further computational analysis, employing density functional theory calculations based on the experimental data, revealed the involvement of multiple molecular orbitals of Cr(VI) in the removal process. It also elucidated a step-by-step reduction pathway for Cr(VI) characterized by decreasing free energy. These findings provide evidence-based insights into Cr(VI) remediation using S-nZVI and can serve as valuable technical support for future environmental management of heavy metals.Journal of Hazardous Material