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Evaluating the Impact of Lighting Conditions on Workers' Safety and Health in Industrial Settings
No full textopen access articleLighting is a key element of design that plays an important role in affecting workers’ health and safety in industrial workspaces. Given the scarcity of scientific studies addressing visual environments in relation to workers health in industrial buildings, this field study was conducted to explore workers' responses to multiple lighting scenarios inside production halls on their occupational health and safety in six factories in Sadat City, Egypt. Self-assessments of 456 factory workers during day and night shifts were collected and correlated to light measurements collected at the factories. The statistical analysis of data revealed a significant reduction in workers reporting eye strain, alleviating headaches, and enhancing the ability to concentrate under daylight conditions compared to mixed and/or artificial lighting conditions. Moreover, it was found that lighting levels lower than 140 lux led to visual fatigue(p=0.03), headaches (p=0.014), drowsiness (p=0.004), and rapid loss of concentration (p=0.149) among workers. Poor lighting was shown to increase the likelihood of making occupational errors. Despite the health benefits of natural light compared to artificial lighting, glare from sunlight can sometimes cause headaches. This study emphasizes the importance of improving lighting quality in production halls within industrial environments, as it is a crucial factor in maintaining the health and safety of workers and enhancing professional performance
The need for absorptive capacity alleviates the free-rider problem in knowledge production
No full textKnowledge sharing is central to strategy and organizational learning, yet its effect on knowledge production remains underexplored. When knowledge diffuses too easily, individuals may free-ride on others’ costly
knowledge production, creating a suboptimal equilibrium in which knowledge sharing persists but the average payoff is no greater than if everyone produced knowledge independently—a paradox first identified by
Rogers (1988). We develop a game-theoretic model to reexamine this puzzle. In our baseline model, we
reproduce Rogers’ paradox: frictionless sharing does not increase performance beyond individual knowledge
production alone. We then extend the model to incorporate absorptive capacity—the need for prior investment in one’s own knowledge before learning from others. Absorptive capacity discourages pure free-riding.
Counterintuitively, although it introduces frictions in knowledge sharing, absorptive capacity increases collective knowledge production beyond the level attainable through individual knowledge production alone.
This explains why extensive knowledge sharing in domains such as academia does not erode incentives
for knowledge production and contributes to knowledge-based theories of the firm by showing that while
hierarchical control may be crucial in contexts in which knowledge is simple and codifiable, but less necessary where knowledge is complex and tacit. More broadly, our analysis illustrates how formal modeling can
uncover overlooked mechanisms and integrate insights across cultural evolution, organizational learning, and
strategy
Tensile behaviour and microstructure of wire-based laser directed energy deposited normal- and high-strength steels
No full textWire-based laser directed energy deposition, referred to as DED-LB or WLAM, is an emerging additive method using laser-melted wire feedstock, offering high deposition rate, smooth surfaces, and high precision. These capabilities indicate strong potential for construction, particularly for complex and optimised components, yet structural adoption necessitates in-depth assessments of mechanical and microstructural properties. This study describes a detailed experimental investigation into the mechanical behaviour and microstructural characteristics of ER70S-6 normal-strength and ER110S-G high-strength steels produced by DED-LB, with focus on property variability and orientation-induced anisotropy, compared with wire-based arc directed energy deposition (i.e., DED-Arc or WAAM). Tensile tests are performed on as-built specimens extracted from various orientations, with 3D scanning quantifying surface undulations, and digital image correlation recording full-field strains. The microstructures are characterised using optical and scanning electron microscopy and electron backscatter diffraction, and microhardness is mapped to microstructural phases. The results show that both steels show favourable stiffness properties and ductility with modest orientation-dependent anisotropy, where ultimate strength ratios across orientations are 0.95–1.00, and elongation ratios are 0.94–1.06. Most coefficients of variation for tensile strength and fracture elongation are found to be below 0.07, comparable to conventional steels. Dominant microstructural phases are shown to be uniformly distributed, with observed layer boundary regions in agreement with local microhardness. Relative to DED-Arc, DED-LB steels, especially for the high-strength grade, are shown to exhibit higher ductility with reduced orientation sensitivity while maintaining comparable strengths. Overall, the findings provide as-built dataset for informing wire-based process assessment and selection for civil engineering applications
Profiling vaccine attitudes and subsequent uptake in 1·1 million people in England: a nationwide cohort study
No full textBackground
Despite highly effective vaccines against SARS-CoV-2, COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic, with rates and motivations for hesitancy varying by demographic group. Addressing the drivers of vaccine hesitancy through targeted interventions in hesitant groups is a public health priority for better and more rapid control of disease spread. We aimed to characterise the determinants and subtypes of vaccine hesitancy and identify more persistent forms of hesitancy via analysis of vaccine uptake in a large cross-sectional cohort with linked National Health Service (NHS) data.
Methods
We conducted an initial cross-sectional analysis of vaccine hesitancy at baseline, followed by a longitudinal analysis of vaccine uptake in the hesitant cohort. We analysed survey data from the Real-time Assessment of Community Transmission (REACT) studies, which monitored the prevalence of SARS-CoV-2 in England during the COVID-19 pandemic at regular intervals from May 1, 2020, to March 31, 2022, in random samples of the population. Participants self-reported detailed sociodemographic information, vaccination status, and attitudes towards vaccination. Participants were classified as hesitant if they reported that they had refused, planned to refuse, or had not yet decided whether to receive the COVID-19 vaccine. Participants who said they were unvaccinated when NHS records showed that they had been vaccinated were excluded from further analysis. The primary outcome of the cross-sectional analysis was vaccine hesitancy. Longitudinal analysis of vaccine uptake was done in participants in the hesitant cohort who consented to the use of linked NHS vaccination records to track their vaccination history after the survey, with post-survey vaccination as the outcome. Consensus clustering was used to categorise reasons for vaccine hesitancy, and cross-sectional and longitudinal analyses used logistic regression models to identify demographic predictors of vaccine hesitancy and subsequent vaccination.
Findings
Our analyses included 1 137 927 adults (aged 18 years and older) surveyed between Jan 6, 2021, and March 31, 2022. Across the whole study period, 37 982 (3·3%) participants indicated some form of vaccine hesitancy. Hesitancy rates peaked at 8·0% in early 2021, subsequently decreasing to a low of 1·1% at the start of 2022, and increasing to 2·2% in early 2022. Of the 24 229 participants who indicated hesitancy and consented to NHS data linkage, 15 744 (65·0%) went on to receive one or more vaccinations. Cluster analysis identified eight stable categories of vaccine hesitancy, including concerns about effectiveness and side-effects, perception of low risk from COVID-19 and mistrust of vaccine developers, and fear of vaccines and reactions. The most prevalent categories of hesitancy, related to effectiveness and health concerns, declined substantially over the roll-out period and were not strongly associated with the likelihood of later vaccination. Some forms of hesitancy, primarily related to low trust, low risk perception, and general anti-vaccine sentiment, were more resistant, rebounded in 2022, and were strongly associated with a lower likelihood of subsequent vaccination.
Interpretation
Our findings suggest that most COVID-19 vaccine hesitancy was rooted in concrete concerns that can be addressed and successfully overcome with time and increasing availability of information. These findings should help future vaccination roll-outs to encourage vaccine acceptance.
Funding
UK National Institute for Health and Care Research, UK Research and Innovation, and the UK Department of Health and Social Care
The protective stepping response in patients with bilateral vestibular hypofunction
No full textObjective: Protective stepping following postural instability is a defence mechanism that prevents falls. Vestibular patients have increased risk of falling but little is known about their stepping response. Here, we investigate whether the protective stepping response is preserved in patients with bilateral vestibular hypofunction (BVH).
Methods: This cross-sectional study, conducted in a balance-research facility, measured body sway and protective stepping responses during a dynamic postural task (platform oscillations at different velocities). Patients diagnosed with BVH were recruited from neuro-otology clinics. As stepping may be dictated by instability perception, objective sway and subjective instability were also analysed for each participant.
Results: 12 patients (4 males, age:65.1, SD:14.2 years) and 12 healthy age and gender matched controls (age:64.8, SD:5.3) were recruited. Patients swayed more than controls (t:-2.153,p=0.03,d=-0.39) and showed marginally steeper objective-subjective instability curves than controls (t:-2.082,p=0.053,d=-0.85), meaning they felt slightly more unstable than controls for the same amount of sway. However, stepping velocity thresholds (t:-1.013,p=0.324,d=0.45) and latencies (t:0.062,p=0.951,d=-0.02) were not different between patients and controls.
Discussion: These results indicate that the protective stepping response is preserved in BVH patients, hence not critically dependent on vestibular input. Only chronic patients were included, which limits the generalisation of the results to acute phases of the vestibular loss
Utilisation of hormone replacement therapy in Arab countries: a systematic review
No full textBackground: Menopause is a major transition in women’s health and may be associated with vasomotor symptoms and increased risk of osteoporosis and cardiovascular disease. Hormone replacement therapy (HRT) is an effective treatment option, yet uptake is reported to be limited in many settings. This systematic review aimed to synthesise evidence on factors associated with HRT uptake and utilisation in Arab countries and to summarise proposed strategies to support informed decision-making.
Methods: We searched Embase, MEDLINE, WHO IRIS, Cochrane Library, PubMed, and Scopus for studies published up to March 2025. Eligible studies examined HRT uptake/utilisation, knowledge, perceptions, or attitudes among women in the 22 Arab countries. Two reviewers screened records using Covidence, with disagreements resolved by a third reviewer. Study quality was assessed using the Newcastle–Ottawa Scale adapted for cross-sectional studies. Findings were synthesised thematically. PROSPERO: CRD420251007430.
Findings: Fifteen cross-sectional studies met inclusion criteria. HRT uptake was generally low; in 11 studies fewer than 20% of participants reported use, with reported prevalence ranging from 0% to 48% across settings. Factors positively associated with uptake included higher educational attainment, employment, healthcare provider influence and access to consultation, and greater baseline knowledge of menopause and HRT. Barriers included risk concerns, cultural conservatism, and preference for herbal or “natural” remedies. In several studies, media was a primary source of menopause-related information, while physician-led counselling was less frequently reported.
Conclusion: Evidence from Arab countries indicates predominantly low HRT utilisation, shaped by knowledge gaps, risk perceptions, and socio-cultural factors, alongside variable healthcare-provider engagement. Studies most commonly recommended community education and strengthened clinician communication to support informed decision-making
The LIRA-Ising model: estimating the boundaries of irregularly shaped X-ray sources
No full textMapping the boundary of an extended source is a key step in the study of its morphology. The background contamination and statistical fluctuations of typical astronomical images make this a challenging statistical task, particularly for X-ray images with low surface brightness. We develop a three-step Bayesian procedure to identify the boundaries of irregularly shaped sources. We first apply a Bayesian multiscale reconstruction algorithm known as LIRA to obtain posterior pixelwise probability distributions of the source intensity that properly account for known structures, astrophysical background, and the effect of the telescope point spread function. Next, we adopt an Ising model to group pixels with similar intensities into cohesive regions corresponding to background and source. Finally, the boundary is derived on the basis of the most likely aggregation of pixels into the source region. Because the overall model combines LIRA and the Ising model, we call it LIRA-Ising. We verify the proposed method using a set of simulation studies. We then apply it to the Chandra X-ray Observatory images of two high redshift quasars, PKS J1421−0643 and 0730+257, to determine the extent and morphology of X-ray jets. Our method shows a uniform X-ray surface brightness of PKS J1421−0643 jet, and identifies knotty structure in the X-ray jet of 0730+257
The mosaic memory of Large Language Models
No full textAs Large Language Models (LLMs) become widely adopted, understanding how they learn from, and memorize, training data becomes crucial. Memorization in LLMs is widely assumed to only occur as a result of sequences being repeated in the training data. Instead, we show that LLMs memorize by assembling information from similar sequences, a phenomenon we call mosaic memory. We show major LLMs to exhibit mosaic memory, with fuzzy duplicates contributing to memorization as much as 0.8 of an exact duplicate and even heavily modified sequences
contributing substantially to memorization. Despite models displaying significant reasoning capabilities, we somewhat surprisingly show memorization to be predominantly syntactic rather than semantic. We finally show fuzzy duplicates to be ubiquitous in real-world data, untouched by deduplication techniques. In this work, we show memorization to be a complex, mosaic process, with real-world implications for privacy, confidentiality, model utility and evaluation
A note on piecewise affine decision rules for robust, stochastic, and data-driven optimization
No full textMulti-stage decision-making under uncertainty, where decisions are taken under sequentially revealing uncertain problem parameters, is often essential to faithfully model managerial problems. Given the significant computational challenges involved, these problems are typically solved approximately. This short note introduces an algorithmic framework that revisits a popular approximation scheme for multi-stage stochastic programs by Georghiou et al. (2015) and improves upon it to deliver superior policies in the stochastic setting, as well as extend its applicability to robust optimization and a contemporary Wasserstein-based data-driven setting. We demonstrate how the policies of our framework can be computed efficiently, and we present numerical experiments that highlight the benefits of our method