Light pollution by coastal streetlights affects intertidal grazers and biofilm differentially in natural rocky habitats and breakwaters.

Life on Earth evolved in the presence of recurring environmental cycles, namely 12.4-hour tidal cycles, 24-hour day-night cycles, 14.77-day semilunar cycles, 29.5-day lunar cycles, and 1-year annual cycles. In anticipation of predictable conditions associated with these geophysical cycles, organisms have evolved corresponding endogenous time-keeping mechanisms-so-called biological clocks. These clocks oscillate with periods that closely match the periods of the environmental cycles and are therefore called circatidal, circadian, circasemilunar, circalunar, and circannual clocks. While circadian clocks are best studied, and circannual clocks are known to exist in several species, the existence of circatidal, circasemilunar and circalunar clocks is often questioned in terrestrial species. The role of semilunar and lunar rhythms in the reproduction of marine organisms is well known, and they have been shown to rely on circa(semi)lunar clocks in several cases. As life originated in the sea, circa(semi)lunar clocks are likely to be ancient timing mechanisms, which may also be present in terrestrial animals, including humans. Increasing evidence suggests that physiology, metabolism and behaviors including reproduction follow (semi)lunar rhythms in humans and many other animals. Here, we present an overview of (semi)lunar rhythms in animals, with evidence that some of the rhythms are governed by circa(semi)lunar clocks, including those in humans. We compare the properties of circadian clocks with those of circa(semi)lunar clocks, including their entrainment by environmental light cycles - daily light/dark cycles in the former case and monthly full moon/new moon cycles in the latter case, and we examine their putative selective advantages. Finally, we discuss the negative effects of artificial light at night on the entrainment of the putative human circa(semi)lunar clock. Based on all of these observations, we hypothesize that humans possess a circa(semi)lunar clock that was mainly entrained by the environmental moonlight cycles before the introduction of artificial light.

This work pioneers in photohydrogenotrophic cultivation of Rhodobacter capsulatus in an open, non-axenic bubble column reactor to maximize biomass productivity and selectivity for purple non-sulphur bacteria. Using full-spectrum light and non-limiting ammonium levels, biomass productivity reached up to 0.98 gTSS L-1 d-1. To enhance microbial selectivity, two operational strategies were tested: (i) alternating of full light spectrum exposure and infrared light which increased pigment production (15 ± 1 mg bacteriochlorophyll gVSS-1 and 4.7 ± 0.5 mg carotenoids gVSS-1) and protein content (0.78 ± 0.22 g protein gVSS-1) while minimizing microalgae content and (ii) ammonium limitation that stimulated the biological nitrogen fixation capability of purple non-sulphur bacteria, resulting in the highest purple non-sulfur bacteria abundance, representing up to 96% of the prokaryotic community, without compromising on productivity. These results demonstrate the feasibility of open culture photohydrogenotrophic cultivation, offering a stepstone to scalable and ecologically aligned alternative for microbial protein production for food and biobased applications.

Tetracycline and ciprofloxacin reduce nitrification and denitrification activity and alter microbial community composition and activity in microalgal-bacterial aerobic granular sludge.

Microplastics in the environment can age under the influence of light， high temperature， and mechanical forces， releasing nanoplastics and soluble organic matter， which in turn have more severe impacts on the environment. In cold regions， microplastics in water and soil surfaces are usually affected by both light and freeze-thaw cycles， but the aging mechanism and the release characteristics of solubles under their combined effects remain unclear. This study investigated the apparent characteristics， changes in functional groups， and release characteristics of solubles of polypropylene microplastics （PP-MPs） under different durations of light， freeze-thaw， and combined aging treatments through a freezing simulation experiment. The results showed that after light aging treatment， holes and wrinkles appeared on the surface of PP-MPs， while after the freeze-thaw treatment， cracks and peeling occurred. After the combined aging treatment， the degree of damage on the surface of PP-MPs was significantly greater than that under the single-factor aging treatments. The increase in the hydroxyl and carboxyl indices of PP-MPs was higher after freeze-thaw and combined treatments. Under light， freeze-thaw， and combined treatments， the order of the five typical peaks of PP-MPs was： -CH3 → -OH → C=O → C-C → -CH2， -CH3 → C-C → -CH2 → C=O → -OH， and -CH3 → C-C → -CH2 → C=O → -OH， respectively. The concentration of DOC released by PP-MPs changed within the ranges of -0.076 mg-1.843 mg， -0.076 mg-1.778 mg， and 0.086 mg-1.803 mg， respectively， showing an initial increase followed by a decrease. The abundance of nanoplastics released by PP-MPs changed within the ranges of 1.16×109-4.34×1010 particles·mL-1， 1.87×109-3.12×1010 particles·mL-1， and 1.87×109-3.12×1010 particles·mL-1， respectively. Under light conditions， the abundance of nanoplastics increased with time， and the particle size decreased with time. Under freeze-thaw and combined treatments， the abundance of nanoplastics decreased， and the particle size increased. This study can provide a theoretical basis for clarifying the environmental effects and aging mechanisms of microplastics in cold regions.

ABSTRACT Disruption of circadian rhythm is common in rotating shift workers, individuals with jet lag, and people with irregular sleep schedules and contributes to metabolic diseases including obesity, type 2 diabetes, metabolic dysfunction-associated steatotic liver disease, and hepatocellular carcinoma. To delineate early metabolic consequences of circadian disruption, we examined glucose, iron, and lipid homeostasis in a murine model of chronic jet lag. Mice were exposed to a validated protocol in which the light cycle was advanced by 8 hours every 2 days, and blood was collected at four Zeitgeber times (ZT0, ZT6, ZT12, ZT18). Jet-lagged mice displayed a progressive rise in random blood glucose toward the dark phase, whereas controls remained within the normal range with a distinct circadian pattern (p < 0.05), suggesting altered glucose regulation across day and night. Serum iron remained within normal limits and showed only minor circadian variation compared with controls (p < 0.05), indicating largely preserved iron homeostasis. In contrast, lipid metabolism was profoundly altered. Total cholesterol and triglycerides were significantly higher and exhibited phase-shifted rhythms, with exaggerated nocturnal peaks and light-phase elevations. HDL levels were consistently reduced, while LDL/VLDL showed marked increase in concentration (all p < 0.05). These patterns are consistent with disturbed hepatic lipid synthesis, export, and peripheral uptake and with increased nocturnal lipid mobilization. Correlation analysis revealed moderate positive associations of glucose with triglycerides and VLDL, a strong correlation between cholesterol and LDL, and a strong inverse correlation between triglycerides and HDL, whereas iron showed only weak relationships with metabolic traits. Together, these data indicate that chronic circadian misalignment preferentially disrupts coordinated glucose and lipid metabolism while iron levels showed modest variations, consistent with early metabolic alterations associated with circadian disruption.

As the supply of light on Earth is cyclic and asymmetric, living systems that rely on photochemical energy have adapted to accommodate periods of light and darkness. During the day, light energy is available, while throughout the dark phases, thermal relaxation processes can be used to increase functional and structural organization. While light-driven supramolecular assembly has been reported, structural adaptation under alternating light/dark input remains largely unexplored in synthetic supramolecular systems. Here, we show how an oscillating light energy supply can facilitate the structural selection of self-assembling photoswitchable peptides compared to continuous illumination. We demonstrate that polymorphic self-assembled structures are transiently formed and sustained only under light irradiation, while alternating periods of irradiation and darkness favor the formation of a thermodynamically more stable supramolecular architecture. These findings demonstrate the key role that rest (darkness) periods can have in the self-assembly pathway selection of molecular and self-organized supramolecular photosystems.

Gut dysbiosis is a characteristic feature of malnutrition; however, a standardized microbial index for assessing gut health in community settings is lacking. This study aimed to assess the relative abundance of key bacterial communities in underweight, obese, and normal-weight children and adolescents using quantitative polymerase chain reaction (qPCR). We conducted a 12-month case-control study (February 2023-February 2024) in Hyderabad, India, involving 70 children aged 8-18 years. Participants were categorized as thin (Body Mass Index-for-age Z-score (BAZ) < -2 SD; n = 23), normal-weight (n = 24), or obese (BAZ > +2 SD; n = 23). Socio-demographic and anthropometric data were collected. Fecal samples were analyzed for relative abundance of target bacteria species using quantitative PCR (Roche Light Cycler 480). Conditional and unconditional logistic regression models were used to assess associations between bacterial abundance and nutritional status. Obese children had higher odds of Lactobacillus spp. (matched odds ratio [mOR] 12.92, 95% CI 1.48-112.86; p = 0.02) and Faecalibacterium prausnitzii (mOR 5.49, 95% CI 1.06-28.49; p = 0.04) compared with normal-weight children. Bacteroides spp. were more abundant in obese (mOR 11.10, 95% CI 1.15-107.20; p = 0.04) and thin children (mOR 8.10, 95% CI 0.87-75.99; p = 0.07). In contrast, Bifidobacterium spp. showed lower abundance in both obese (mOR 0.006, 95% CI 0.00-0.07) and thin children (mOR 0.54, 95% CI 0.01-0.47) relative to normal-weight peers. This study identified distinct patterns of gut bacterial dysbiosis, characterized by altered relative abundances of Lactobacillus, Faecalibacterium prausnitzii, Bacteroides, and Bifidobacterium, among children and adolescents across different nutritional statuses. These microbial signatures may serve as potential early indicators of malnutrition-related dysbiosis and warrant further investigation.

Metabolic syndrome (MetS) is a chronic metabolic disorder whose global prevalence continues to rise, imposing a significant burden on public health. With the development of round-the-clock societies, shift work has become increasingly commonplace. A growing body of epidemiological evidence indicates that circadian rhythm disruption constitutes a predictable risk factor for MetS; however, the precise mechanisms underlying this relationship remain inadequately understood. This study employed golden hamsters as a model to investigate the effects of circadian rhythm disruption simulated by cyclic light (CL) exposure on MetS. Thirty-three male golden hamsters (7 weeks old, body weight 120-160 g) were randomly assigned to four groups for a 6-week intervention: the Control group (normal light + normal diet, ND), the high-fat diet group (normal light + HFD, to induce a MetS model), the cyclic light group (CL + normal diet, CL), and the CL + HFD group (CL + HFD). Outcome measures included metabolic indicators, hepatic histopathology, and gut microbiota (analyzed via 16S rDNA sequencing). The stability of the MetS model was assessed through measurements of body weight, fasting blood glucose, and total cholesterol levels. The results indicated that CL exposure may further aggravate metabolic disorders associated with MetS. Furthermore, it was observed that CL exposure intensified MetS-related disturbances in gut microbiota, evidenced by an increase in α-diversity and distinct separation in β-diversity. CL exposure in the MetS model golden hamsters resulted in a reduced abundance of Bacteroidetes and Weissella, alongside an overgrowth of Helicobacter. Circadian rhythm disruption is an independent risk factor for MetS. It further exacerbates metabolic indicators by inducing gut microbiota dysbiosis and promoting the growth of harmful bacteria. Future research should integrate functional metabolomics with faecal microbiota transplantation studies to validate causal mechanisms and explore clinical translational value. Circadian rhythm disruption is an independent risk factor for MetS. It exacerbates the pathological progression of MetS by reducing beneficial bacteria and promoting the growth of harmful bacteria, thereby further damaging its metabolic indicators.

To address the challenge of comparing entire chromatograms, three tile-based comparative analysis methods (Fisher ratio, pairwise, and relative variance ranking) were applied to data collected by comprehensive two-dimensional gas chromatography with vacuum ultraviolet spectroscopy detection (GC × GC-VUV). The tile-based scheme, originally developed for time-of-flight mass spectrometry (TOFMS) detection, was adapted herein to rank analytes on a hit list according to the metric for each method. We analyzed a GC × GC-VUV data set comprising 14 gas oils from five sample classes: straight-run (SR), light cycle oil (LCO), coker (CK), hydroconverted (HDC), and hydrotreated (HDT). Three replicates each of HDT and LCO gas oil GC × GC-VUV data were analyzed by Fisher ratio analysis with 459 out of 557 analyte hits exhibiting at least a 2-fold change, which were visualized by 2D chromatogram projections. Additionally, multivariate curve resolution-alternating least-squares was applied to obtain the pure VUV spectrum of each analyte, which was readily classified into five compound classes (saturates, olefins, mono-, di-, and triaromatics) and projected onto the 2D separation space to visualize the positions of these compound classes. Next, pairwise analysis, either between replicates of the same sample or between samples within the same sample class was studied. A concentration ratio >1.2 was determined as the 99% confidence level threshold for distinguishing analyte hits from background variation. Finally, relative variance analysis of all 24 gas oil chromatograms combined with principal component analysis enabled unsupervised differentiation of the five gas oil sample classes.

ABSTRACTAdvances in optogenetics now allow specific modifications to the DNA of live cells with light. However, successfully using these technologies requires knowing their properties in terms of sensitivity, efficiency, kinetics and mechanism. We previously developed an optogenetic tool made of a single chimeric protein called LiCre that enables the induction of specific changes in the genome with blue light via DNA recombination between loxP sites (Duplus-Bottin et al., 2021). Here, we used in vitro and in vivo experiments combined with kinetic modeling to provide a deeper characterization of the photoactivated LiCre-loxP recombination reaction. We find that LiCre binds DNA with high affinity in the absence of a light stimulus and that this binding is cooperative, although not as much as for the Cre recombinase from which LiCre was derived. In yeast, the addition of riboflavin to the culture medium had no effect on LiCre's efficiency, even when cells over-expressed riboflavin kinase, suggesting that the abundance of the flavin mononucleotide cofactor is not limiting for the reaction. However, LiCre's efficiency in yeast gradually increased when raising the temperature from 20°C to 37°C. The recombination kinetics observed in live cells are best explained by a model where the photoactivation of two or more DNA-bound LiCre units (happening in seconds) can produce (in several minutes) a functional recombination synapse. This model was able to capture the effect of a point mutation altering LiCre's light cycle. This deeper understanding of the LiCre-loxP system provides additional knowledge for designing experiments where specific genetic changes are induced in live cells with light.

Diatoms are tiny algae that play a key role in Earth's ecosystems by absorbing carbon and producing oxygen. They also create valuable pigments with properties that can protect against environmental stress and may have uses in health, food, and industry. This study reveals how diatoms adapt to changing light conditions, which are common in natural waters. Researchers found that short intervals of light and darkness can boost diatom growth and increase pigment production, especially under very short light cycles. By exploring the genes and biochemical processes involved, the study offers new insight into how these microorganisms survive in dynamic environments. This knowledge could help improve the sustainable production of diatom-derived pigments for a range of practical applications, from food coloring to natural health products.

Melatonin (N-acetyl-5-methoxytryptamine) is a neuroendocrine hormone primarily secreted by the pineal gland and also produced in extrapineal tissues such as the retina, lymphocytes, and the cardiovascular (CV) system. This hormone possesses amphiphilic properties, allowing it to penetrate most biological barriers and exert its effects at the subcellular level; it plays an important role in controlling the body's response to circadian rhythms and adjusting to internal and external environmental cues. It also has antioxidant, anti-inflammatory, and antiaging properties. Melatonin's secretion is controlled by daily and seasonal environmental light cycles. Its production is strictly occurs during the night and is inhibited by light. Besides these chronobiotic actions, this hormone possesses vasoactive properties mediated by the plasma membrane melatonin receptors (MT1/MT2) and ion channels expressed in the CV system. The responses triggered by melatonin in the CV system vary depending on the vascular bed analyzed and hormone concentration. Also, MT1 receptors likely mediate vasoconstrictor effects, whereas MT2 receptors mediate vasorelaxant effects. Furthermore, there is a gap in the literature, as very few studies have addressed the effects of circadian variations on the expression of these receptors, pointing to an important area for further investigation. In summary, melatonin is a robust antioxidant agent and free radical scavenger, guarding cells from oxidative damage. Within its wide spectrum of diverse physiological roles, such as maintaining the functional integrity of endothelial cells, thus averting atherosclerosis, a major contributor to CVD, melatonin exhibits antioxidant and free radical scavenging properties, potentially ameliorating cardiometabolic disorders, and, as herein detailed, it has a unique adjunctive therapeutic potential for managing various CVDs via several mechanisms by which melatonin interacts with the CV system. All these issues are herein reviewed, the results of relevant meta-analyses are tabulated and discussed, and the actions and influences of melatonin on the CV system are detailed and pictorially illustrated.

The lack of physiologically relevant and controllable experimental systems has limited mechanistic understanding of age-related macular degeneration (AMD) and the development of effective therapeutic strategies. Here, we present a tunablein vitroretinal pigment epithelium (RPE) stress model that integrates engineered light delivery with lipid modulation to reproduce early AMD-like cellular pathology under standard culture conditions. Human RPE cells (ARPE-19 and iPSC-derived RPE) were exposed to precisely controlled, low-intensity light-induced oxidative stress in the presence of docosahexaenoic acid (DHA), a highly unsaturated retinal lipid, or palmitic acid (PA) as a saturated lipid control. Cellular responses were assessed using functional and structural readouts including lysosomal and mitochondrial activity, membrane integrity, epithelial morphology, tight junction organization, and lipid peroxidation. A programmable LED-based exposure system enabled fine control over light intensity, duration, and cycling, allowing delivery of sub-lethal, chronic oxidative stress. Combined light and DHA exposure selectively induced lipid peroxidation, disruption of ZO-1-defined tight junctions, and progressive loss of RPE viability, while PA-treated cells and non-retinal HuH7 hepatocytes showed minimal sensitivity. ARPE-19 cells responded rapidly, whereas iPSC-derived RPE cells exhibited delayed but comparable pathological changes, reflecting differences in cellular maturity and stress resilience. Pharmacological inhibition of ferroptosis using ferrostatin-1 significantly reduced lipid peroxidation and rescued epithelial integrity and cell viability, identifying ferroptosis as a key mechanism underlying RPE vulnerability in this system. By enabling programmable and reproducible delivery of oxidative lipid stress, this modular light-based platform provides a biofabrication-compatible framework for modeling early AMD, with potential for integration into more complex retinal constructs, co-culture systems, and high-throughput therapeutic screening pipelines.

• Direct recycling of HCO, LCO, and HN to RFCC feed was evaluated using ACE microreactor testing. • Mono-aromatics enhance gasoline formation, while di-aromatics preferentially generate LCO. • ATR + HN achieved the highest conversion and gasoline yield among all blended feeds. • Increasing catalyst-to-oil ratio raised gasoline and olefin yields while reducing LCO and MCB. • Recycling RFCC side streams enables operational control of refinery product value and flexibility. This study examines the recycling of heavy cycle oil (HCO), light cycle oil (LCO), and heavy naphtha (HN) into the feed of a residue fluid catalytic cracking (RFCC) reactor to evaluate their effects on product yield distribution. The objective is to develop strategies for steering RFCC operations toward higher-value products. The recycled streams, rich in aromatic compounds, were tested in a fixed fluidized bed microreactor (ACE test) using a commercial RFCC equilibrium catalyst. The NOFs (neat oil fractions), namely HCO, LCO and HN, and blended feeds with atmospheric residue (ATR) were cracked at 520 °C under varying catalyst-to-oil (C/O) ratios. Conversion of the NOFs followed the order HN (99 wt%) > LCO (87.5 wt%) > HCO (42 wt%), with corresponding gasoline yields of 69, 51, and 14 wt%. For blended feeds, ATR + HN achieved the highest conversion (79.1 wt%) and gasoline yield (51 wt%), while ATR + LCO generated the most olefins. Results demonstrate that mono-aromatics act as gasoline precursors, whereas di-aromatics favor LCO formation. Increasing C/O ratio enhanced gasoline and olefin yields while reducing LCO and main cycle oil. These findings highlight the potential of recycling side streams to optimize RFCC performance and improve refinery fuel flexibility.

Plastic waste management is a major challenge for our society. The use of refinery facilities offers the possibility of treating them neatly or blending them with refinery streams to obtain products suitable for adaptability to market requirements. In this sense, this work investigates the production of automotive fuels through the hydrocracking of a blend composed of plastic-derived pyrolysis oil (PPO) and light cycle oil (LCO). First, three catalysts (PtPd/HZSM-5, PtPd/HY, and NiW/HY) were tested to study the influence of their acid, metallic, and structural properties in the hydrocracking reactions. This was performed using a PPO/LCO blend (20:80 in mass) at 400 °C, 60 bar, H2:feed volumetric ratio, 2000:1, space-time, 0.23 g h gfeed -1, and time on stream (TOS), 8 h. The PtPd/HY catalyst exhibited good capacity for fuel production; its medium acid strength, superior hydrogenation capacity, and microporous structure favored gasoline production, reaching a selectivity of 81 wt %. With this catalyst, the effects of pressure and the amount of PPO in the blend were also assessed. At high pressures (80 bar), overcracking reactions were more likely to occur, while the conversion of heavy fractions remained constant. A similar trend was observed when the PPO loading was increased up to 40 wt %, the formation of light compounds was promoted to the detriment of the conversion of heavy fractions and gasoline formation.

Cellular- and systems-level profiling of amyloid-beta effects on circadian timing.

Cross-sectional and longitudinal associations between circadian alignment and stroke in US adults.

Synthetic plug-in fatty acid pathway for stress-adaptive lipid accumulation in Chlamydomonas reinhardtii.

Toward energy-efficient extraction of aromatics from light cycle oil using deep eutectic solvents: Insights from experimental and process evaluation