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M-FISH evaluation of chromosome aberrations to examine for historical exposure to ionising radiation due to participation at British nuclear test sites
Get PDFAll data that support the findings of this study are included within the article (and any supplementary files).Data availability statement:
All data that support the findings of this study are included within the article (and any supplementary files) available online at: https://doi.org/10.1088/1361-6498/ad1743 .Veterans of the British nuclear testing programme represent a population of ex-military personnel who had the potential to be exposed to ionising radiation through their participation at nuclear testing sites in the 1950s and 1960s. In the intervening years, members of this population have raised concerns about the status of their health and that of their descendants, as a consequence. Radiation dose estimates based on film badge measurements of external dose recorded at the time of the tests suggest any exposure to be limited for the majority of personnel, however, only ∼20% of personnel were monitored and no measurement for internalised exposure are on record. Here, to in-part address families concerns, we assay for chromosomal evidence of historical radiation exposure in a group of aged nuclear test (NT) veterans, using multiplex in situ hybridisation (M-FISH), for comparison with a matched group of veterans who were not present at NT sites. In total, we analysed 9379 and 7698 metaphase cells using M-FISH (24-colour karyotyping) from 48 NT and 38 control veteran samples, representing veteran servicemen from the army, Royal Airforce and Royal Navy. We observed stable and unstable simple- and complex-type chromosome aberrations in both NT and control veterans' samples, however find no significant difference in yield of any chromosome aberration type between the two cohorts. We do observe higher average frequencies of complex chromosome aberrations in a very small subset of veterans previously identified as having a higher potential for radiation exposure, which may be indicative of internalised contamination to long-lived radionuclides from radiation fallout. By utilising recently published whole genome sequence analysis data of a sub-set of the same family groups, we examined for but found no relationship between paternal chromosome aberration burden, germline mutation frequency and self-reported concerns of adverse health in family members, suggesting that the previously reported health issues by participants in this study are unlikely to be associated with historical radiation exposure. We did observe a small number of families, representing both control and NT cohorts, showing a relationship between paternal chromosome aberrations and germline mutation sub-types which should be explored in future studies. In conclusion, we find no cytogenetic evidence of historical radiation exposure in the cohort of nuclear veterans sampled here, offering reassurance that attendance at NTs sites by the veterans sampled here, was not associated with significant levels of exposure to radiation.Nuclear Community Charity Fund (NCCF) through funds received by The Armed Forces Covenant Fund Trust under the Aged Veterans Fund Grants AVF15A and AVF16. The funding organization had no role in the design and conduct of the study; in the collection, management, analysis and interpretation of the data; or in the preparation, review or approval of the manuscript
Fibroblastic tissue growth on polymeric electrospun membranes: a feasibility study
Get PDFData availability: Data sets generated during the current study are available from the corresponding author on reasonable request.Article Highlights:
• This work shows human mammary fibroblasts (HMF) grown on a selection of electrospun membranes to find the optimal substrate.
• The biodegradable polymeric membranes (PU, PCL/PU, PCL/Ge and PVA) were chosen to avoid the use of expensive alternatives such as Matrigel.
• It was found that the human mammary fibroblasts proliferated and organised themselves depending on scaffold properties, such as porosity, fibre diameter and wettability.All experiments were conducted in the Organ-on-a-Chip Research and Tissue Culture laboratories of Brunel University London.In recent years the interest in synthetic scaffolds has increased significantly as an alternative to animal-derived materials, as well as the advancement of material and manufacturing engineering, has resulted in improved standardisation and reproducibility within the field. Despite these advancements, a significant amount of research on animal-derived scaffolds, whilst research on synthetic materials is lacking for the growth of non-tumourgenic breast cell lines. The main objective of this work is to manufacture biodegradable scaffolds using biocompatible materials such as PVA (Polyvinyl Alcohol), PU (Polyurethane), Ge (Gelatin) and PCL (Poly-(-caprolactone) to test human cell adhesion and investigate the optimal system that supports representative tissue organisation and that could be used as an alternative to Matrigel™. Here, human mammary fibroblasts (HMF) were used as proof of concept. The membranes were manufactured using the process of electrospinning and characterised by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (ATR-FTIR), contact angle, tensile strength, and degradation studies. The assessment of the membranes as a viable biomaterial for the growth and development of cells was studied by MTT proliferation assay, fluorescence microscopy and SEM imaging. Results demonstrate that all materials are suitable for HMF proliferation. However, from microscopy analysis, only PU and PVA membranes induced morphological organisation of HMF similar to those results obtained in the Matrigel™ control conditions. This feasibility study reveals that HMF organisation, and proliferation are affected by the properties of the scaffold. Consequently, scaffolds parameters should be adjusted and manipulated to impact cell behaviour and emulate in vivo conditions.Engineering and Physical Sciences Research Council (EPSRC) Doctoral Training Programme Studentship and a research grant from Breast Cancer UK (BCUK)
The impact of waste brick and geo-cement aggregates as sand replacement on the mechanical and durability properties of alkali–activated mortar composites
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Data will be made available on request.This study explores the potential of waste brick and geo-cement aggregates as substitutes for natural sand in alkali-activated materials (AAMs) for mortar production. With a focus on achieving net-zero construction and mitigating environmental impact, the study replaces Portland Cement (OPC) and virgin aggregates with waste materials and by-products. The investigation evaluates the substitution of sand (up to 100 % by weight) in AAMs with waste brick aggregates (WBA) and waste geo-cement aggregates (WGA) obtained from demolished construction and research lab waste, respectively. The research methodology involves assessing mechanical, durability, and microstructure properties to assess the performance of the developed AAMs with waste aggregates. Notably, AAM composites containing waste brick and geo-cement aggregates surpass natural aggregate composites in terms of mechanical strength, water absorption, freeze-thaw resistance, acid ingress, and chloride attack. The 7-day 50 % waste brick mixture achieved a maximum compressive strength of 61 MPa, while a 70 % waste geo-cement mortar mixture attained a maximum flexural strength of 12 MPa. Combinations, whether comprising waste brick or geo-cement mortar aggregates, demonstrate compressive strengths well over 40 MPa, rendering them suitable for heavy load-bearing structures. The 50 % waste geo-cement mortar mixture stands out with the lowest water absorption rate of 6 % and the least compressive strength loss of 13 % after the freeze-thaw test, with reductions of 6 % and 18 %, respectively, compared to the control. Additionally, 100 % waste brick AAMs exhibit the lowest compressive strength loss after chloride and acid attack tests, with reductions of 13 % and 2.5 %, respectively. When compared to all other mixtures, the 50 % waste brick aggregates mortar mixture obtained the best overall performance. The composites developed in this study affirm their suitability for use in heavy-load structural components, showcasing favourable mechanical and durable properties. These findings underscore the need for additional exploration in this direction to advance sustainable construction practices.10.3030/101029471 - European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement ID: 101029471 (DigiMat project)
Thermo-haemodynamic coupling during regional thigh heating: Insight into the importance of local thermosensitive mechanisms in blood circulation
Get PDFData Availability Statement - The raw, unidentified data collected throughout this study will be made available via Brunel Figshare, an online data repository database.A positive relationship between local tissue temperature and perfusion exists, with isolated limb-segment hyperthermia stimulating hyperaemia in the heated region without affecting the adjacent, non-heated limb segment. However, whether partial-limb segment heating evokes a heightened tissue perfusion in the heated region without directly or reflexly affecting the non-heated tissues of the same limb segment remains unknown. This study investigated, in 11 healthy young adults, the lower limb temperature and haemodynamic responses to three levels of 1 h upper-leg heating, none of which alter core temperature: (1) whole-thigh (WTH; water-perfused garment), (2) quadriceps (QH; water-perfused garment) and (3) partial-quadriceps (PQH; pulsed shortwave diathermy) heating. It was hypothesised that perfusion would only increase in the heated regions. WTH, QH and PQH increased local heated tissue temperature by 2.9 ± 0.6, 2.0 ± 0.7 and 2.9 ± 1.3°C (P 0.5000). These findings in healthy young humans demonstrate a tight thermo-haemodynamic coupling during regional thigh heating, providing further evidence of the importance of local heat-activated mechanisms on the control of blood circulatio
Modeling and control of functional electrical stimulation cycling training system
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The datasets generated and/or analyzed during the study are limited due to data confidentiality reasons, which are used under the license of this study and are therefore not publicly available. However, if they makes a reasonable request and obtains permission from the Shandong Provincial Third Hospital, the corresponding author can be contacted to obtain the data.Functional electrical stimulation (FES), a rehabilitation technique, typically relies on physiotherapists using trial-and-error tests to determine effective stimulation patterns. Therefore, this study proposed a kind of pedal hill modeling to establish an optimal stimulus mode with the maximum torque efficiency optimization objective. This study also proposed a new model based on the particle swarm optimization (PSO) algorithm, the back propagation (BP) neural network algorithm, and the proportional integral derivative (PID) control composite algorithm. Six participants were recruited for the experiment. Using the proposed modeling method, we found an appropriate stimulation mode for each of the six subjects, and then each subject performed three sets of experiments for cycling without electrical stimulation, cycling with fixed pulse width, and cycling with adaptive adjustment of pulse width by the fabricated controller. The results of the study showed that root mean square error (RMSE), average (AVE), training time and number of stops all performed well compared to the no control and fixed control conditions and the adaptive pulse width control system of the fabricated controller allows subjects to train at a longer continuous running time and a more stable cycling training speed.This research was funded by National Natural Science Foundation of China under Grant, grant number 62371172
Adaptive Decentralized State Estimation for Multimachine Power Grids Under Measurement Noises With Unknown Statistics
Get PDFThis article is concerned with the adaptive dynamic state estimation (DSE) problem for synchronous-generator-based multimachine power grids under measurement noise with unknown statistics. The statistical properties of the measurement noises are efficiently revealed by utilizing limited measurement data contained in a sliding window, and such data is employed to establish the base distribution of the noises, with the aid of the Gaussian mixture model and the kernel density estimation scheme. Subsequently, the component number of the base distribution of the measurement noises is reduced by designing a fuzzy C-means clustering algorithm with the Wasserstein distance criterion. An improved sliding-window-based adaptive cubature Kalman filtering scheme is then proposed, which leverages the already obtained statistical characteristics of the measurement noise and the concept of the Gaussian summation filter. Finally, the validity of the proposed adaptive DSE algorithm under various measurement noise statistics is illustrated by simulation studies conducted on the IEEE 39-bus system featuring three test scenarios.10.13039/501100001809-National Natural Science Foundation of China (Grant Number: U21A2019, 61933007, 62273088, 62373241 and 62303301);
theShanghai Pujiang Program of China (Grant Number: 23PJD040);
Royal Society of the U.K.;
Alexander von Humboldt Foundation of Germany
Adult-onset testosterone deficiency: the usefulness of hormone replacement in reducing mortality in men with this common age-related condition
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Datasets are available on request.Adult-onset testosterone deficiency (TD) in men is diagnosed by the finding of low serum testosterone levels and recognised, associated symptoms. The condition has high prevalence in men over 50 years of age, particularly those with type 2 diabetes (T2DM). Accumulating data show adult-onset TD is associated with increased mortality risk. We review the literature and consider the evidence suggesting testosterone therapy (TTh) reduces mortality, especially in men with T2DM. We previously reported that in the Burntwood Lichfield Atherstone Sutton Coldfield Tamworth (BLAST) study screened cohort of men with adult-onset TD and T2DM adult-onset TD was associated with increased mortality with TTh decreasing this higher mortality. The data hinted that the effect was greater in older men. We confirmed this observation with statistical analyses to study the effect of age on the association between adult-onset TD and mortality; Cox regression analysis demonstrated that the reduced risk (hazard ratio: 0.61, 95% CI: 0.38–0.96) following TTh was restricted to men above the median age of 65.89 years. Finally, we speculate on putative mechanisms that may mediate these associations. Heterogeneity in men with adult-onset TD is expected in view of its definition of low testosterone levels together with associated clinical phenotypes that are not always directly related. Many of these classifying phenotypes are associated with increased mortality. Thus, it is perhaps possible that mechanism(s) of all-cause mortality reduction following TTh is via the impact on these associated phenotypes such as the metabolic syndrome (MetS), hyperglycaemia, hypertension, dyslipidaemia, low haematocrit, sex hormone binding levels, erectile dysfunction, etc. We propose that further research studying the effect of TTh takes heterogeneity into account.Grant from North Staffordshire Medical Institute (Grant Number: [PID-200078])
Enhancing crime prediction with machine vision: Convolutional neural network approach
Get PDFThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonCrime significantly challenges socio-economic development, hindering societal progress and stability. This PhD Thesis focuses on training and comparing YOLOv4 with SSD models for classifying high-risk perpetrators. The annotated training dataset comprises approximately 3,118 images, including common weapons such as shotguns, handguns, rifles, and knives. It was sourced from the UCF and the NIST criminal databases. The secondary sources are trusted, compliant with data privacy laws, and personal identifiable information was anonymized before used for training. The models’ validation shows effective object detection, with YOLOv4 achieving a mean Average Precision (mAP) of 90.58%. It achieves a 75.99 % precision for identifying persons of interest between 4,000 and 10,000 epochs. This model excelled most at detecting knives, achieving a precision of 96.11% with 80 instances predicted correctly (TP) with 2 incorrect prediction (FP). The recall rate of 74.5% for YOLOv4 indicates the model identified about 74.5% of actual positive instances. Moreover, with an F1 score of 77.2%, our findings highlight a balance between precision and recall. However, there is room for improvement due to 259 (FN) missed objects out of the 1205 total predictions. In contrast, the SSD model achieved 66.5% precision for persons, with its highest precision for handguns at 81.42 %. But adjusting configuration variables (hyperparameter tuning) improved the model’s mAP to 84.19%, indicating better generalization and prediction across classes. Both architectures performed well by reducing misclassification including maintaining relatively high true positive and low false positive rates across all classes. To enhance pre-crime analysis, the YOLOv4 model was integrated with the Deep-SORT tracker to maintain object identities over time and improved the model's ability to identify weapon sub-objects on individuals and categorize potential perpetrator as high-risk
The Use of Machine Learning In Assessing Future Sustainability of Newly Developed Solar Thermal Systems
No full textAn artificial neural network (ANN) model developed in MATLAB was used to predict the environmental performance of an innovative solar thermal system, ASTEP (Application of Solar Energy to Industrial Processes) over a 30-year period. The system was applied to the industrial processes of two end-users, Mandrekas (MAND) and Arcelor Mittal (AMTP). The ASTEP system was designed to supply thermal energy up to 400°C and consist of three main components: a novel rotary Fresnel Sundial, thermal energy storage (TES) and a control system. The actual GHG emissions of the ASTEP system and a solar thermal plant as presented in the literature were used to evaluate the ability of the ANN model to predict GHG emissions. The actual and predicted emissions were compared to assess the accuracy of the model. Validation results showed a difference of 2.13 kgCO2eq/kWh for AMTP’s ASTEP system, 2.43 kgCO2eq/kWh for MAND’s ASTEP system and 0.32 kgCO2eq/kWh for a third solar thermal plant. These findings indicate that the ANN model could be considered as an effective tool in predicting GHG emissions for solar thermal plants allowing the industry to evaluate their environmental performance and adopt measures to reduce their impact.This research is funded by the EU Horizon 2020 research and innovation programme, Application of Solar Energy in Industrial processes (ASTEP), grant number 884411
Momentum Returns and Corporate Governance
Get PDFJEL classification: G11, G12, G30, G40, G41, O16.This is a working paper. It is not certified by peer review.We hypothesize that corporate governance affects, first, how a firm is perceived by investors in terms of risk, transparency, and valuation and, second, investors’ decisions to buy/sell past winning/losing stocks during good and bad times. Implementing momentum strategies on portfolios of US stocks with different corporate governance scores demonstrate that past winners and losers with weak shareholder rights exhibit significant positive excess returns during expansionary and recessionary periods, respectively. This is consistent with the return behavior of winners and losers when momentum is applied across all stocks. Overall, investors are less (more) reluctant to sell (buy) losing (winning) stocks of weak compared to strong shareholder rights companies. Results show that stocks with weak shareholder rights may be less informationally efficient and subject to biased valuations
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