Photochemistry and Photobiology

Continuous-wave (CW) 450 nm blue diode-laser irradiation was evaluated as a physical seed-priming treatment for improving lettuce (Lactuca sativa L.) germination and early seedling establishment under reduced water availability. Dry seeds were irradiated at 50-250 mW for 2 min and at 100 mW for 0.5-10 min; each condition included three independent Petri-dish replicates with 100 seeds per replicate, and the replicates were monitored for 72 h. Laser treatment produced a dose-dependent biological response. The optimized condition, 100 mW for 2 min, increased final germination from approximately 65-70% to 90-95%, increased the germination speed index, and promoted root elongation more strongly than shoot elongation. Longer exposures reduced germination and seedling growth. Under reduced water availability (0.5-6 ml per Petri dish), laser-treated seeds germinated earlier, maintained final germination of 83-93% compared with 57-72% in controls, and produced better-developed seedlings. The relative benefit increased as water availability decreased, indicating that optimized blue laser priming partially compensated for low water supply during germination and early establishment. These results identify CW blue laser priming as a contactless, chemical-free approach for improving lettuce seed performance and early seedling vigor under limited water availability.

Light reaching the retina is a primary regulator of human circadian physiology, acting largely through melanopsin-expressing retinal ganglion cells with peak short-wavelength sensitivity. Delivering known, repeatable retinal doses outside the laboratory is difficult because conventional light sources leave viewing geometry, gaze, and ambient conditions uncontrolled. Consumer extended-reality (XR) glasses fix a bright binocular display in constant geometry relative to the eye, but their suitability as calibrated photic stimulators has not been established. Here we validate a commercial micro-OLED XR display (VITURE Luma Ultra) for controlled retinal photostimulation. A purpose-built host application renders exact 8-bit RGB stimuli while independently controlling hardware brightness and logging all intensity-determining state; spectral radiance was measured at the retinal position of a 3D-printed phantom head with an open-source miniature spectroradiometer, anchored to absolute units by a luminance transfer calibration. The blue primary peaks at 461 nm (FWHM 43 nm), is spectrally invariant across a >10-fold intensity range, and at maximum output delivers an estimated 299 lx melanopic equivalent daylight illuminance, above consensus daytime recommendations, while remaining roughly two orders of magnitude below photobiological safety limits. The red primary is visually effective with minimal melanopic drive (melanopic DER 0.10), enabling spectrally shifted evening stimulation. Unlike the immersive virtual-reality headsets previously used for calibrated light delivery, the see-through form factor preserves the wearer's view of the surroundings--relevant for clinical monitoring in supervised settings such as the intensive care unit. These results show that consumer XR glasses can serve as a dose-calibrated platform for wearable photostimulation using an open-source measurement chain, and provide groundwork for application-layer dose-response studies.

Ultraviolet-C (UV-C) radiation can be highly damaging to plants, yet its effects on gibberellin (GA) homeostasis are not well understood. In this study, we show that short daily UV-C pulse treatments (12 s, 1,200 J m-2) applied for seven days reduce plant height and delay flowering in Arabidopsis thaliana. Endogenous levels of the GA biosynthesis precursors GA12, GA53, GA15, and GA24, the bioactive GA4, and the GA catabolites GA34 and GA110 are all lower in UV-C treated plants than in untreated controls. These changes were accompanied by lower transcript levels of the GA biosynthesis genes KS, GA13ox1, GA20ox1, and GA3ox1, together with opposing changes in the expression of GA2ox genes. Exogenous GA4 restores growth in UV-C-treated plants, suggesting that reduced GA availability contributes to UV-C-induced growth inhibition. Consistent with this finding, the GA-signalling mutant gdella and the GA-biosynthesis mutants kao1 and kao2 show strongly reduced UV-C responses. Together, these findings highlight the importance of GA metabolism and signalling in the developmental response to repeated UV-C exposure, and suggest that exposure regimen influences the dynamics of UV-C-induced hormonal responses.

Blue light using Flavin (BLUF) proteins are microbial photoreceptors that are involved in various physiological responses. Their occurrence and biochemical properties in fungi remain poorly understood. Here, we investigated a putative BLUF photoreceptor from the corn-smut fungus Mycosarcoma maydis (MmBLUF). Domain analysis, multiple sequence alignment of BLUF core regions, and structural modelling indicated conserved canonical BLUF fold and flavin-pocket residues. However, when heterologously expressed, UV-visible and fluorescence spectroscopy revealed different spectral behaviour than canonical BLUF protein. Further, we tested the role of extended N-terminus in modulation of chromophore binding by expressing N-terminus truncated protein variants. Our results suggest that the unusual spectral behaviour is not linked to the truncation construct (extended N-terminus), which also showed similar spectral features, indicating that the extended N-terminus is unlikely to account for an unusual photodynamics characteristics. Our findings support MmBLUF as a structurally conserved putative fungal BLUF-like photoreceptor with different photochemical properties. Further studies are required to establish its chromophore identity, photocycle and function of this unusual BLUF-like domain from fungal system.

Reported relative biological effectiveness (RBE) values for low-energy X-rays disagree, assays scoring initial DNA double-strand breaks (DSBs) returning about 1.1 and chromosome-level assays 2 to 4. Whether radiation quality varies within the diagnostic range, and how its comparison with a megavoltage reference depends on target scale, has not been quantified on a tube-potential series. A tungsten-anode tube with 1 mm Be and 2.5 mm Al filtration, with copper added in some cases, was modelled in PHITS for 40 to 200 kV. The spectra were transported into a water phantom in which absorbed dose, lineal-energy densities and cluster size distributions were scored for target diameters of 3 nm to 1 micrometre against a cobalt-60 reference; DSB yields were computed in the electron track-structure mode with the PHITS DNA damage tally. Between 40 and 120 kV the depth-dose ratio changed by a factor of 5.7 and the tube output by a factor of 42, whereas the dose-mean lineal energy varied by 2.5 % at 1 micrometre and 1.2 % at 3 nm against a reproducibility of 0.3 %. Relative to cobalt-60 it was 2.05 times larger at 1 micrometre but only 1.08 times larger at 3 nm, while DSB yields per unit dose were 5 to 7 % higher and constant across the range within the 2 % bound set by the statistics. Tube potential therefore changes the amount and distribution of dose but not its physical quality, and a stated RBE is incomplete without the target scale implied by the endpoint.

Introduction Anatomical endoscopic enucleation of the prostate (AEEP) techniques, including bipolar enucleation (B-TUEP), holmium laser enucleation (HoLEP), thulium laser enucleation (ThuLEP), and thulium fibre laser enucleation (ThuFLEP), demonstrate comparable clinical outcomes for benign prostatic hyperplasia. As clinical equivalence is increasingly established, cost becomes a key determinant of modality selection. We performed a cost minimisation analysis comparing index procedural costs across AEEP modalities from an institutional perspective. Methods A cost minimisation model was developed from the institutional perspective, incorporating amortised capital costs, maintenance, and consumables. In addition to the base-case scenario of 180 cases per year, we modelled two additional case volume scenarios: low (50 cases/year) and high (500 cases/year) volume. Thu:YAG laser fibres were modelled on two scenarios: disposable single-use, and reusable fibres (up to 10 cases per fibre). Breakeven analysis determined the threshold volume at which each laser modality achieves cost parity with B-TUEP, and one-way sensitivity analysis was performed on key cost parameters. Analysis was limited to index procedural costs calculated in Singapore dollars. Results At the base case of 180 cases per year, B-TUEP had the lowest index procedure cost (SGD 1,018), followed by ThuFLEP (SGD 1,584), ThuLEP (1,599), and HoLEP (SGD 1,655). Breakeven analysis demonstrated that HoLEP, ThuLEP, and ThuFLEP can never achieve cost parity with B-TUEP when laser fibres are single-use, as laser modalities carry higher costs on both capital and per-case dimensions. ThuLEP with reusable fibres (10 uses per fibre) was the only modality to cross below B-TUEP, at a breakeven volume of 198 cases per year. At 500 cases per year with reusable fibres, ThuLEP achieved the lowest cost (SGD 847), representing a 15.4% saving over B-TUEP. Sensitivity analysis identified annual case volume and B-TUEP loop cost as the most influential parameters. Conclusion Index procedural costs in AEEP are strongly influenced by case volume and consumable strategy. While B-TUEP remains cost-efficient at low volume, high-volume practice combined with reusable Thu:YAG fibre technology enables cost parity and potential cost advantage for laser enucleation. These findings highlight the importance of economies of scale and device utilisation in technology adoption.

Background: Autonomous ultraviolet-C (UV-C) disinfection systems are increasingly used to supplement manual environmental cleaning, yet evidence-based guidance defining pathogen-specific UV-C dose requirements across representative surfaces remains limited. Aim: To characterize operational UV-C dose requirements for clinically relevant pathogens across diverse high-touch and healthcare surfaces and determine how experimentally derived microbial inactivation can inform operational exposure parameters. Methods: SARS-CoV-2, adenovirus, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Candida auris, and Clostridioides difficile spores were exposed to defined UV-C doses on representative high-touch materials or stainless steel under standardized conditions, including a 10% fetal bovine serum organic soil challenge. Microbial inactivation was quantified by viable recovery. Dose-response analysis and operational modelling were used where supported by the experimental data. Findings: UV-C exposure significantly reduced viable recovery of all pathogens, with substantial differences in the exposure conditions associated with microbial inactivation. SARS-CoV-2 exhibited substantial inactivation at doses as low as 2.6 mJ/cm2, whereas the highest evaluated doses were 1,800 mJ/cm2 for C. difficile spores and 3600 mJ/cm2 for C. auris. For C. auris, multi-dose data estimated that approximately 1,410 mJ/cm2 was associated with a 2-log10 reference reduction, enabling distance-dependent exposure-time predictions. Conclusion: Experimentally quantified UV-C exposures produced substantial microbial inactivation across diverse pathogen classes and surfaces. Integrating delivered dose with microbial reduction provides a quantitative framework for translating laboratory efficacy into operational parameters for autonomous UV-C disinfection.

The rise of antimicrobial resistance has intensified interest in antimicrobial photodynamic inactivation (aPDI) and antimicrobial blue light (aBL) as alternatives or adjuvants to conventional antibiotics. However, whether chemically distinct photodynamic treatments elicit a shared bacterial response remains unclear. Here, we integrated transcriptomic profiles of Escherichia coli BW25113 exposed to five short-term, sub-lethal photodynamic treatments: antimicrobial blue light (aBL), aBL combined with 5-aminolevulinic acid (aBL+ALA), rose bengal (RB), new methylene blue (NMB), and the cationic porphyrin TMPyP. Intersection analysis identified 891 conserved core genes differentially expressed across all treatments, of which approximately 98% changed in a consistent direction despite differences in photosensitizer chemistry and activating wavelength. Random-effects meta-analysis and robust rank aggregation prioritized 88 high-confidence genes, revealing induction of envelope stress and cytoplasmic protein quality control pathways alongside repression of acid resistance, hydrogen metabolism, molybdate transport, and biofilm formation. Regulon enrichment indicated that heat-shock sigma factor {sigma}32/RpoH and the envelope-stress regulators CpxR, BaeR, {sigma}24/RpoE, and PspF were enriched among induced genes, whereas GadW/GadX/GadE, Fur, and {sigma}38/RpoS were enriched among repressed genes. Functional validation using selected single-gene Keio knockouts confirmed that deletion of conserved-core genes sensitized E. coli to photodynamic treatment and delayed post-treatment recovery in a modality-dependent manner. Moreover, RT-qPCR analysis of selected transcriptional responses confirmed the direction and overall pattern of RNA-seq-derived expression changes. Together, these findings define a unified conserved early survival program in E. coli after chemically distinct photodynamic treatments and identify stress-response modules that may serve as targets for potentiating aPDI. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/744726v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@dbbadaorg.highwire.dtl.DTLVardef@1c85538org.highwire.dtl.DTLVardef@152d699org.highwire.dtl.DTLVardef@18705a6_HPS_FORMAT_FIGEXP M_FIG C_FIG

Occupational ocular injuries are a preventable yet neglected public health problem, particularly in low- and middle-income countries. Maintenance workers are exposed to diverse ocular hazards daily, yet compliance with protective measures is consistently poor. A descriptive cross-sectional study was conducted among 85 maintenance workers at the Maintenance and Essential Services Organization (MESO) of Kwame Nkrumah University of Science and Technology (KNUST), Ghana, recruited through stratified convenience sampling across seven occupational sections. A structured questionnaire assessed knowledge of ocular hazards and protective equipment, attitudes toward ocular safety, and safety practices. Data were analyzed using IBM SPSS version 26 (IBM Corp., Armonk, NY, USA); chi-square and Fishers exact tests assessed associations (p < 0.05). Participants were predominantly male (84/85, 98.8%), with a mean age of 44.5 {+/-} 10.4 years. Overall knowledge was good (mean 9.40 {+/-} 1.59 out of 11), but attitude and practice scores were average (2.78 {+/-} 0.92 and 3.27 {+/-} 0.93, respectively). Most workers correctly identified goggles and face shields as protective, but only about half recognized that ordinary sunglasses and spectacles offer inadequate protection. Although 97.6% (83/85) recognized the need for ocular protection, only 7.1% (6/85) reported consistent protective eyewear use, and fewer than half (45.9%, 39/85) had received formal ocular safety training. Routine general protective equipment use was significantly associated with ocular protection use (Fishers exact test, p = 0.011). Sand and dust particles were the leading causes of injury and only 25% (5/20) of injured workers sought formal care. Workers demonstrated good knowledge but poor attitudes and practices toward ocular safety, suggesting that knowledge alone does not translate into protective behaviour even within a relatively well-resourced institutional setting. Findings suggest that limited access to task-appropriate protective eyewear may represent an important institutional barrier. Institutional PPE supply and section-specific safety training are essential to bridge this knowledge-practice gap.

Background: Children spend more than 90% of their time indoors, and early childhood education settings (ECEs) are an understudied, high-occupant-density indoor microenvironment where exposure to volatile organic compounds, particulate matter, and other toxicants has been documented. Limited knowledge exists on ECE-specific exposures affecting young children and how they compare to exposures in the home. Methods: This prospective, repeated-measures pilot study targeted enrollment of 44 preschool-aged children and 8 ECE staff across two geographically and sociodemographically distinct ECEs in metropolitan Atlanta, Georgia. Paired silicone wristbands, one home-designated and one ECE-designated, were exchanged between settings across three consecutive days and nights beginning at enrollment to characterize microenvironment-specific exposure. A single spot urine sample was also collected from each child. Continuous indoor air quality monitoring was conducted in two classrooms per site. Caregivers and ECE staff completed structured questionnaires assessing home and ECE environmental characteristics, child respiratory risk, and protocol feasibility and acceptability. Feasibility was evaluated using eight pre-specified indicators spanning recruitment and enrollment, wristband wear duration and loss by microenvironment, urine sample collection completeness, and survey completion by instrument and respondent group. Conclusion: This pilot will establish feasibility and acceptability parameters for a paired, multi-matrix silicone wristband protocol across home and ECE microenvironments. Findings will inform the design, sample size, and power calculations for a subsequent study testing indoor air interventions and pediatric respiratory outcomes in ECEs. Feasibility outcomes are reported in a companion manuscript.

Abstract Importance: Access to eye care is increasingly constrained by declining ophthalmologist workforce density, particularly in rural areas, while optometrist workforce is projected to exceed demand. Numerous state legislatures have expanded optometrist scope of practice (SOP), but the workforce effects of these policies have not been evaluated.. Objective: To evaluate changes in optometrist and ophthalmologist workforce density following state-level expansion of optometrist scope of practice. Design: This retrospective ecological study analyzed workforce density across 50 states and the District of Columbia. Between 2008 - 2019, nine states expanded SOPs for optometrists. We used interrupted time-series regression to estimate associations between these policy changes and provider density from 2010-2021, adjusting for covariates. Setting: Population-based analysis of all 50 US states and the District of Columbia, 2010 - 2021. Participants: State-level workforce data were derived from Bureau of Labor Statistics and US Census data (optometrists) and the American Medical Association Physician Masterfile (ophthalmologists). Socioeconomic covariates were obtained from the American Community Survey. Exposure: State-level legislative expansion of optometrist SOPs to allow injections beyond anti-anaphylaxis treatment, lesion removal, and/or laser procedures. SOP changes were identified through systematic review of legislative and regulatory records. Main Outcomes and Measures: Annual change in optometrist and ophthalmologist workforce density (providers per 100,000 population) following SOP expansion, adjusted for age, income, rates of vision difficulty, diabetes, poverty, and uninsured status. Results: Nine states met inclusion criteria for SOP expansion between 2008 and 2019. Analysis of national data showed that among all 50 US states and the District of Columbia, SOP expansion was associated with a non-significant change in optometrist density (-0.65 per 100,000; 95% CI, -1.87 to 0.57) and ophthalmologist density (+0.09; 95% CI, -0.10 to 0.28). Results were consistent in the 9-state subgroup (optometrists: -0.60, 95% CI -2.90 to 1.70; ophthalmologists: +0.02, 95% CI -0.13 to 0.18). Conclusions and Relevance: Our population-level data suggest that, in the US, state legislation expanding optometrist scope of practice has not been associated with increased workforce density. As numerous state legislatures continue to consider such policies, these findings can inform efforts to balance access to eye care with patient safety.

Radiation oncology has a long history of developing in-house health information technology (HIT) tools such as quality assurance (QA) checklists, yet there is little guidance from professional bodies on how to implement these tools in complex clinical environments. Building on our previous work that used human-centered participatory co-design, the Task-User-Representation-Function (TURF) framework, and multi-method usability evaluations to design and develop an enhanced dosimetry QA checklist (DQC), this study investigated the barriers and facilitators (determinants) to implementing the enhanced DQC in a radiation oncology clinic, examined implementation strategies, proposed an implementation framework for QA checklists in radiation oncology, and assessed four implementation outcomes: acceptability, appropriateness, feasibility, and adoption. We conducted a qualitative implementation study using an abductive research approach at an academic medical center. All key stakeholders (dosimetrists, physicists, trainees, and software developers) participated in semi-structured interviews, field observations, and surveys across pre-implementation, implementation, and post-implementation phases. Data were analyzed using a hybrid inductive-deductive approach, with deductive coding guided by an adapted Consolidated Framework for Implementation Research (CFIR) mapped to the Unified Theory of Acceptance and Use of Technology and by the Expert Recommendations for Implementing Change (ERIC) compilation. We identified 4 CFIR constructs and 12 sub-constructs as barriers, with structural characteristics and planning showing the highest negative valence, and 5 CFIR constructs and 19 sub-constructs as facilitators, with relative advantage, culture, and leadership engagement showing the highest positive valence. Participants' suggestions mapped to 19 ERIC strategies in 7 clusters, and the CFIR-ERIC matching tool identified 14 evidence-based strategies in 4 clusters that informed a proposed phased implementation framework. Acceptability, appropriateness, and feasibility scores improved significantly from pre-implementation to implementation for all professional roles (p<0.05), yet adoption reached 100% only in the sixth week of implementation. These findings highlight the value of combining subjective and objective implementation outcomes and provide a practical, evidence-based framework for implementing in-house QA checklists in radiation oncology that warrants validation in diverse settings.

2,4-Dinitrochlorobenzene (DNCB) is a well-characterized skin sensitizer that has been widely used in immunological and toxicological research and, historically, in clinical immunotherapy. Although it is a well-investigated chemical, this is the first study focusing on the dose response behavior at low-level concentrations. The aim was to reveal potential hormetic effects due to its known Nrf2 inducting activity. Therefore, THP-1 cells were treated with low doses of DNCB and two endpoints were evaluated for hormetic responses: metabolic activity using a resazurin-based assay and immune activation by measuring CD86 and CD54 expression using flow cytometry. The results showed a significant hormetic effect on the metabolic endpoint at the lower cell density for both analyzed time points, and a hormetic tendency at the higher cell density. Metabolic activity increased to approximately 125% of the control at 0.05 micromolar DNCB. For the immunological endpoint a slight decrease in CD86 and CD54 surface marker expression was observed, up to -16% and up to -12% compared to control at 0.5 micromolar DNCB. These findings highlight the importance of including low dose concentrations when characterizing chemical dose-response relationships and evaluating toxicological risk.

Background: An estimated 826 million people have avoidable near vision impairment (NVI) due to lack of access to near vision glasses for presbyopia. Glasses use, uptake and replacement is essential to sustained NVI correction. Here we explore the uptake of second and subsequent pairs of near vision glasses and the willingness to pay. Methods: In this cross-sectional survey, 276 individuals who received near vision glasses through eye health screening programs in Punjab province, Pakistan from 2020 to 2022, were surveyed between February and July 2025, i.e. 3-5 years later. Results: 92.0% (n=254) of respondents were still using near vision glasses: a purchased replacement (41.3%, n=114), a free replacement (30.8%, n=85), or the original pair (19.9%, n=55). Male gender, higher age, and personal income were strongly associated with purchasing additional pairs, while women and those economically dependent on others relied more on free provision (all p values <0.05). Accessibility, indicated by shorter travel times and awareness of supply sources, also played a significant role in sustained replacement. Over 98% of participants expected to obtain (purchase or receive) a new pair of glasses in the future, and over 94% of participants expected to purchase their next pair. The mean willingness-to-pay (WTP) was 353 PKR (95% CI: 327-379) // 1.25 USD (95% CI: 1.16-1.34), while the average reported price paid was 416.67 PKR // 1.47 USD (95% CI: 351.39-481.94)). Conclusion: Sustained use of near vision glasses remained high 3-5 years after initial provision. Many recipients had purchased replacements, and willingness and ability to pay were high among participants, suggesting potential for sustained demand beyond initial subsidized distribution.

Previously, we have demonstrated that certain ferric salts common in Archean waters, such as iron trichloride and ferric ammonium citrate, can protect liposomes from destruction by short-wavelength UVC light. In this study, we investigate the propagation of 254 nm UV radiation through aqueous FeCl3 solutions and its interactions with liposomes. We then consider these findings in the context of early Earth UV environment, discuss their implications for our hypothesis of the Darwinian evolution of liposomes, and integrate them with our previous experimental results.

Bacterial melanin are macromolecules found in nature that provide a wide range of biological functions, including pigmentation, resistance to radiation, scavenging of free radicals, thermoregulation and protected from oxidative stress and harmful heavy metals. The melanin is crucial for pathogenesis and bacterial survival in a variety of circumstances, and they can also influence how bacteria interact with other organisms. Usually, bacteria produce the melanin is either black or brown colour. The produced melanin has excellent properties like antimicrobial, antioxidant, photoprotective and antibiofilm. This is a report on Corynebacterium amycolatum melanin-producing bacteria isolated from the marine sediment of Thiruvanmiyur beach in Tamil Nadu, India. Corynebacterium amycolatum was screened using tyrosine basal broth (TBB), and UV-visible spectroscopy, FTIR, and SEM were used to analyse the extracted melanin. The non-pathogenic nature of the Cornynebacterium amycolatum strain was verified through antibiotic sensitivity profiling. The cosmetic potential was evaluated using antioxidant and SPF assays. Corynebacterium amycolatum predominantly uses the DOPA pathway for melanin production, was confirmed using kojic acid inhibitor study. The in vitro studies on mouse fibroblast cell line (L929) and in vivo studies on zebra fish embryos shows non-cytotoxicity using this melanin, even in lower concentration confirms its potential to use in cosmetic formulation. This research aims to demonstrate that bacterial melanin is safe for the environment and has qualities that make it safer and more effective in cosmetics.

Background: Environmental noise and air pollution are both shaped by road traffic and the built environment, and exposure assessment increasingly folds them into composite indices or proxies both by traffic exposure. Whether the two share a social distribution has rarely been tested against direct measurement of several exposures in the same communities, and community noise is almost always characterized by A-weighted levels alone, which discount low-frequency energy. Methods: At 176 sites across Rhode Island, spanning the contiguous urban area of Providence, Central Falls, and Pawtucket together with four rural municipalities, we measured the acoustic environment under A- and C-weighting (LAeq, LCeq), fine particulate matter (PM2.5), night-time illuminance, and relative humidity across four session types over roughly one year (704 site-sessions). Exposures were linked to census-tract composition (American Community Survey), and mixed-effects models were fitted for each of eight area-level markers of disadvantage, adjusting for campaign and session. Relative humidity was carried through the identical model as a negative control. Results: A-weighted noise was consistently higher in more disadvantaged tracts, rising with non-White, poverty, renter, and no-vehicle shares and falling with income and older-resident share (six of eight markers significant; 1.3 to 1.8 dBA per standard deviation; 6.6 dBA between the least and most racially diverse neighborhoods). C-weighted levels followed the same gradient on every marker and exceeded their A-weighted counterparts at block-group scale for renter occupancy and vehicle absence. Night-time illuminance was also socially patterned, whereas short-term PM2.5 was roughly an order of magnitude weaker and relative humidity showed no gradient. The acoustic gradient persisted within the urban core alone. Conclusions: Measured burden was carried by the acoustic environment, including its low-frequency component, and by night-time light, not by short-term particulates. The exposure metric and the averaging time determine which disparities are visible at all.

Per- and polyfluoroalkyl substances (PFAS) pose significant environmental risks, yet their impact on food crops like legumes remain insufficiently understood. This study investigated the developmental and physiological responses of hydroponically grown mung bean (Vigna radiata) to varying concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). High concentrations (1 mM) of PFOA severely impaired early plant development, significantly delaying seed germination, reducing leaf emergence, and suppressing root hair formation compared to PFOS and controls. Over a narrower concentration range (5-500 {micro}M), both compounds caused transient growth stunting at early timepoints (48 h), though plants exhibited partial recovery over time. High-dose exposure (500 {micro}M) significantly decreased seedling wet weights, leaf area, and leaf biomass without affecting dry weights, indicating disrupted water retention and homeostasis rather than reduced biomass accumulation. Spectrophotometric analysis revealed a dose- and compound-dependent effect on photosynthesis, with low-dose PFOA (5 {micro}M) significantly increasing leaf chlorophyll absorbance. Furthermore, quantification of callose deposition revealed that high-dose PFOA (500 {micro}M) and medium-dose PFOS (50 {micro}M) raised baseline immune stress responses, which were not further elevated by subsequent flagellin-22 (flg22) challenge, suggesting a contaminant-induced immune priming mechanism. These findings highlight distinct, chemical-specific toxicological impact of PFAS on legume growth, water dynamics, and defence priming, underscoring critical implications for agricultural productivity and food safety.

Background: In the United States, several states have restricted sales of flavoured tobacco products, including popular menthol- and mint-flavoured Oral Nicotine Pouches (ONP). In response, tobacco companies introduced "unflavoured" ONP containing odorless synthetic cooling agents. Since these, in turn, have become targets of legislative bans, the tobacco industry may seek out flavourants with other sensory effects to increase the appeal of "unflavoured" ONP. Methods: Online merchants were searched for "unflavored" ONP marketed to consumers in jurisdictions with flavour bans. Sensory effects of aqueous extracts from identified "heat", "spicy" and "unflavoured" ONP were analyzed by Ca2+ microfluorimetry in HEK293 cells expressing the human heat/chili pepper flavourant (capsaicinoid) receptor, hTRPV1. ONP were analyzed for capsaicinoids and sweeteners by Liquid Chromatography/Mass Spectrometry (LC/MS). Results: A new category of "heat" or "spicy" ONP was identified, including products marketed as "unflavoured". Extracts from all these ONP robustly activated TRPV1, with "unflavoured" Lucy Heat the most potent. Chemical analysis demonstrated that Lucy Heat contained the synthetic capsaicinoid nonivamide at high levels (~675 microgram/pouch), while others contained mixtures of capsaicinoids (5-25 microgram/pouch) combined with other characterizing flavours (tropical, fruit). All tested ONP contained sweeteners. Conclusions: The tobacco industry continues to probe regulatory loopholes by claiming that newly introduced capsaicinoid flavourants and sweeteners in ONP do not represent characterizing flavours. This is contradicted by industry and regulatory determinations assigning characterizing flavour properties to these additives. The toxicological health risks of repeated capsaicinoid exposures due to ONP use, in combination with nicotine and other constituents, need to be assessed.

The measurement of light received at the cornea of the eye is a paramount consideration for the understanding of the relation between environmental illumination and the non-image-forming effects of light. The field of view (FOV) at the cornea is less than a full hemisphere, because it is partially occluded by human facial morphology. The International Commission on Illumination (CIE) has defined a standard model of human FOV. A suitably designed physical occluder attached to the sensor (of a light meter) has been proposed as a means of incorporating the effect of human FOV when taking measurements. Similarly, when using simulation to predict light received at the cornea, a geometrical description of the occluder at the eye point(s) can be added to the 3D model of the scene. The first occluder model proposed to represent CIE human FOV was enumerated in terms of: the CIE definition; the radius of the occluder; and, the radius of the light sensor disc. We present a simpler model based only on the CIE definition and the occluder radius. Both models were tested using a virtual goniophotometer. Various sensor response functions describing the spatial sensitivity across the sensor disc, including several we characterized through laboratory measurements, were included in the test. For all functions considered, the performance of the simpler occluder model was equivalent to or better than the model first proposed.