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The field of sun protection is quickly changing and the research article by Douki et al., published in the current issue of Photochemistry and Photobiology, reported key experimental data that will certainly help the development of better sun care products. Mutagenic photoproducts (CPDs, cyclobutane pyrimidine dimers and 6‐4PPs, pyrimidine‐6‐4‐pyrimidone photoproducts) were formed in the reconstructed human epidermis (RHE) by UVB (312 nm) irradiation, and their concentrations were detected by HPLC‐MS/MS as a function of time after the UVB treatment. RHE had been previously exposed or not (control) to blue light (427 nm). Both CPDs and 6‐4PPs were shown to last longer in blue‐light irradiated RHE, proving the inhibition of the DNA repair by blue light exposure. This is a highly relevant information because sunscreens allow people to enjoy longer periods under the sun and consequently, to endure very high doses of blue light. The work also reported results obtained with RHEs previously treated with a sunscreen formulation containing a broadband filter that offers blue‐light protection. Interestingly, authors observed that the DNA repair was not significantly inhibited in RHE previously treated with the sunscreen offering broadband protection. Readers will find a scientifically sound proof of the importance of blue‐light protection in sun care products. [ABSTRACT FROM AUTHOR]

We demonstrate femtosecond ultra-stable green laser generation by an ytterbium-doped polarization-maintaining fiber laser with a 2.4 mm long lithium triborate (LBO) crystal. We generated 5.6 W of femtosecond green light at 520 nm for a fundamental power of 12 W, which corresponds to a conversion efficiency of 46.7%. The fiber chirped-pulse amplifier, which has an environmentally immune front end, delivered 170 fs pulses at a 75 MHz repetition rate centered at 1040 nm. According to the dispersion of the optical material in a double-frequency setup, the introduced dispersion had a negligible effect for the green laser, and the pulse duration of the generated green laser was calculated to be 171 fs, resulting in an excellent power stability, with fluctuation as low as 0.16% of the generated green light. This system could be of great interest in ultrafast optical and photobiology research. [ABSTRACT FROM AUTHOR]

Plants use light as a resource and signal. Photons within the 400–700 nm waveband are considered photosynthetically active. Far‐red photons (FR, 700–800 nm) are used by plants to detect nearby vegetation and elicit the shade avoidance syndrome. In addition, FR photons have also been shown to contribute to photosynthesis, but knowledge about these dual effects remains scarce. Here, we study shoot‐architectural and photosynthetic responses to supplemental FR light during the photoperiod in several rice varieties. We observed that FR enrichment only mildly affected the rice transcriptome and shoot architecture as compared to established model species, whereas leaf formation, tillering and biomass accumulation were clearly promoted. Consistent with this growth promotion, we found that CO2‐fixation in supplemental FR was strongly enhanced, especially in plants acclimated to FR‐enriched conditions as compared to control conditions. This growth promotion dominates the effects of FR photons on shoot development and architecture. When substituting FR enrichment with an end‐of‐day FR pulse, this prevented photosynthesis‐promoting effects and elicited shade avoidance responses. We conclude that FR photons can have a dual role, where effects depend on the environmental context: in addition to being an environmental signal, they are also a potent source of harvestable energy. Summary statement: The ratio of red: far‐red (FR) light is monitored by phytochrome photoreceptors as a cue for neighbour proximity, and a drop in this ratio plants elicit so‐called shade avoidance responses. Here we show in a number of rice varieties that FR enrichment triggers only marginal shade avoidance but contributes significantly to leaf‐level photosynthesis and whole‐plant biomass accumulation. [ABSTRACT FROM AUTHOR]

Light quality can be stated to be the identity of an artificial light source, and although the response of light quality may vary depending on the crop, the effect is clearly visible and can produce various results depending on the combination of an artificial light source. This study investigated the spectral reflectance, photosynthetic performance, and chlorophyll fluorescence of mini green romaine lettuce based on light quality. Most parameters related to spectral reflectance showed the best results under blue light, and photosynthetic performance was more effective with mixed light than with single-colored light, among which blue + red (BR)-LED was the most suitable. Red light was ineffective, showing mostly low results in parameters of spectral reflectance and photosynthetic performance. In the case of chlorophyll fluorescence, the light quality influenced photomorphogenesis, resulting in increased leaf length and width with R- and quantum dot (QD)-LED, which expanded the leaf area and allowed for more external light to be captured (ABS/RC and TRo/RC). However, the ratio of electronized energy (ETo/RC) was low, and the amount of energy dissipated as heat (DIo/RC) was high. Consequently, the degree of electron acceptor reduction and overall photosynthetic performance (PIABS and PItotal) were lower compared to other light qualities. Additionally, the contrasting results of QD-LED and BR-LED were attributed to the form of red light and the presence or absence of far-red light when comparing spectra. Principal component analysis also clearly distinguished light qualities for photosynthesis and growth. Growth was increased by red (R)- and QD-LED, while photosynthetic performance was increased by BR- and blue (B)-LED. [ABSTRACT FROM AUTHOR]

Animal vision depends on opsins, a category of G protein-coupled receptor (GPCR) that achieves light sensitivity by covalent attachment to retinal. Typically binding as an inverse agonist, 11-cis retinal photoisomerizes to the all-trans isomer and activates the receptor, initiating downstream signaling cascades. Retinal bound to bistable opsins isomerizes back to the 11-cis state after absorption of a second photon, inactivating the receptor. Bistable opsins are essential for invertebrate vision and nonvisual light perception across the animal kingdom. While crystal structures are available for bistable opsins in the inactive state, it has proven difficult to form homogeneous populations of activated bistable opsins either via illumination or reconstitution with all-trans retinal. Here, we show that a nonnatural retinal analog, all-trans retinal 6.11 (ATR6.11), can be reconstituted with the invertebrate bistable opsin, Jumping Spider Rhodopsin-1 (JSR1). Biochemical activity assays demonstrate that ATR6.11 functions as a JSR1 agonist. ATR6.11 binding also enables complex formation between JSR1 and signaling partners. Our findings demonstrate the utility of retinal analogs for biophysical characterization of bistable opsins, which will deepen our understanding of light perception in animals. [ABSTRACT FROM AUTHOR]

Summary: Diatoms are a diverse group of phytoplankton usually dominating areas characterized by rapidly shifting light conditions. Because of their high growth rates and interesting biochemical profile, their biomass is considered for various commercial applications. This study aimed at identifying strains with superior growth in a photobioreactor (PBR) by screening the natural intraspecific diversity of ecotypes isolated from different habitats. We investigated the effect of PBR light fluctuating on a millisecond scale (FL, simulating the light in a PBR) on 19 ecotypes of the diatom Skeletonema marinoi isolated from the North Sea–Baltic Sea area.We compare growth, pigment ratios, phylogeny, photo‐physiological variables and photoacclimation strategies between all strains and perform qPCR and absorption spectra analysis on a subset of strains.Our results show that the ecotypes responded differently to FL, and have contrasting photo‐physiological and photoprotective strategies. The strains from Kattegat performed better in FL, and shared common photoacclimation and photoprotection strategies that are the results of adaptation to the specific light climate of the Kattegat area.The strains that performed better with FL conditions had a high light (HL)‐acclimated phenotype coupled with unique nonphotochemical quenching features. Based on their characteristics, three strains were identified as good candidates for growth in PBRs. [ABSTRACT FROM AUTHOR]

The sea ice spring bloom is crucial for sustaining Arctic marine food webs, with sea ice algae serving as primary carbon sources for higher trophic levels. Despite the prevailing dominance of diatom species in sea ice spring blooms, our study highlights a notable deviation, showcasing a bloom driven by dinoflagellates. Through field sampling of first-year sea ice cores and subsequent analysis of physical and biogeochemical parameters, combined with amplicon sequencing of the 18S rRNA gene, we investigated the occurrence and implications of this significant dinoflagellate bloom, with a particular focus on Polarella glacialis. Our findings reveal that high irradiances at the top of the ice core, coupled with elevated nutrient availability and warm ice conditions, are key drivers of this phenomenon, as elucidated by redundancy analysis. Moreover, our results suggest a potential climate-driven decline in snow cover on sea ice, increased open leads, and thinner sea ice, which may favor the proliferation of dinoflagellates over diatoms. This alternative dinoflagellate-dominated bloom could have profound ecological consequences, given the enriched omega-3 fatty acid content of dinoflagellates, thereby influencing energy transfer within the Arctic marine food web. Furthermore, our study identifies the presence of not only Polarella glacialis but also Chytridinium, an ectoparasite on copepod eggs, and the green algae Ulothrix in relatively high abundances within the sea ice. These findings shed light on the intricate interplay between environmental factors and microbial community dynamics within Arctic sea ice ecosystems. [ABSTRACT FROM AUTHOR]

We developed a solar-driven photo-bioelectrochemical cell (s-PBEC) employing a novel anode photocatalyst material (Co3(PO4)2/Mg(OH)2) intimately coupled with electrochemically active bacteria for synergic electricity generation from wastewater. An s-PBEC was inoculated with a natural microbial community and fed with synthetic wastewater to analyze the performance of the system for electricity generation. Linear sweep voltammetry indicated an increase in power output upon light illumination of the s-PBEC after 1 h, rising from 66.0 to 91.5 mW/m2. The current density in the illuminated s-PBEC exhibited a rapid increase, reaching 0.32 A/m2 within 1 h, which was significantly higher than the current density in dark conditions (0.15 A/m2). Shotgun metagenomic analysis revealed a significant shift in the microbial community composition with a more diverse anodic biofilm upon illumination compared to the microbial communities in dark conditions. Three unclassified genera correlated with the enhanced current generation in illuminated s-PBEC, including Neisseriales (16.31%), Betaproteobacteria (7.37%), and Alphaproteobacteria (5.77%). This study opens avenues for further exploration and optimization of the solar-driven photo-bioelectrochemical cells, paving the way for integrative approaches for sustainable energy generation and wastewater treatment. [ABSTRACT FROM AUTHOR]

Light intensity significantly influences plant growth in hydroponic green fodder systems, yet research exploring the growth dynamics and nutrient accumulation in hydroponically grown barley under various light conditions has been limited. This study investigated the impact of different light intensities—0, 100, 200, and 300 μmol/m2/s—on the nutritional composition and quality of hydroponic barley fodder. Assessments were made on biomass production, physiological responses including photosynthetic parameters, and nutritional components such as essential amino acids five days post-treatment. The findings indicated that increasing light intensity boosted photosynthetic activity, expanded leaf area, enhanced root length, and promoted biomass accumulation. However, the highest intensity tested, 300 μmol/m2/s, led to significant chlorophyll degradation, increased water loss, and induced oxidative stress, adversely affecting fodder quality and reducing essential amino acids. In contrast, an intensity of 200 μmol/m2/s was identified as optimal for promoting robust barley growth through principal component analysis. This optimal setting supported vigorous growth and ensured the production of nutrient-rich, high-quality fodder, providing a basis for scaling up production efficiently. This research offers crucial insights into optimizing light conditions to maximize both the yield and nutritional quality of hydroponically grown barley fodder, presenting a significant step forward in enhancing hydroponic farming practices. [ABSTRACT FROM AUTHOR]

Mining is increasingly under the scholarly microscope for its social and environmental impacts, including its uneven gender impacts. To study resistance of women across two communities affected by a long-established nickel mining and smelting operation in Indonesia, we paired photovoice with a discussion on conjunctures in the photo-stories. Photovoice is a visual ethnographic method that combines photography and storytelling to explore answers to research questions centered on how research participants make sense of their social worlds. By adding a discussion of conjunctures found in the photo-stories, we noted the combined methods facilitated empathetic responses and cross-community solidarity, a powerful antidote to the hyper-individualism and social discord fostered by mining interests in the neoliberal capitalist period. As Indonesia plans to open dozens more nickel mines and smelters, like the one in our study, in the rush to supply nickel for electric vehicle batteries, our study challenges scholars to look for empathy and solidarity. Seeing and exercising empathy and solidarity are important as extractive interests are expected to continue divide and conquer tactics to secure land and resources for exploitation. [ABSTRACT FROM AUTHOR]

SUMMARY: This study investigates photoreceptor's role in the adaption of photosynthetic apparatus to high light (HL) intensity by examining the response of tomato wild type (WT) (Solanum lycopersicum L. cv. Moneymaker) and tomato mutants (phyA, phyB1, phyB2, cry1) plants to HL. Our results showed a photoreceptor‐dependent effect of HL on the maximum quantum yield of photosystem II (Fv/Fm) with phyB1 exhibiting a decrease, while phyB2 exhibiting an increase in Fv/Fm. HL resulted in an increase in the efficient quantum yield of photosystem II (ΦPSII) and a decrease in the non‐photochemical quantum yields (ΦNPQ and ΦN0) solely in phyA. Under HL, phyA showed a significant decrease in the energy‐dependent quenching component of NPQ (qE), while phyB2 mutants showed an increase in the state transition (qT) component. Furthermore, ΔΔFv/Fm revealed that PHYB1 compensates for the deficit of PHYA in phyA mutants. PHYA signaling likely emerges as the dominant effector of PHYB1 and PHYB2 signaling within the HL‐induced signaling network. In addition, PHYB1 compensates for the role of CRY1 in regulating Fv/Fm in cry1 mutants. Overall, the results of this research provide valuable insights into the unique role of each photoreceptor and their interplay in balancing photon energy and photoprotection under HL condition. Significance Statement: Our research explores the role of photoreceptors in plant response to high light (HL). This is crucial as it reveals the complex regulatory mechanisms involved in plant adaptation to environmental stress. By identifying the precise contributions of photoreceptors, our study expands our understanding of plant photobiology and provides insights for optimizing the conversion of photon energy to photochemical energy under HL conditions. This work lays the foundation for developing strategies to enhance plant resilience in HL condition. [ABSTRACT FROM AUTHOR]

As researchers working with youth in educational settings, we enter the research setting with a clear power differential. We used photo projects with the aim of fostering an environment where youth might express themselves freely and choose the starting point for our conversations. In this article, we share our experiences conducting photo-elicitation with youth at a nongovernmental organization in Guatemala and with high school students in Solomon Islands. It is hard for youth to vocalize the tensions and contradictions they experience growing up in contexts where coloniality continues to exert power in daily life. We suggest that using photo projects as an ethnographic method allows youth to reflect on their identities and desires for the future in a way that opens doors to conversations and reduces the power differential between researcher and participant. This is especially important in educational settings, which often rely on Western standards to shape the futures that young people imagine for themselves. [ABSTRACT FROM AUTHOR]

With the increasing availability of LEDs, researchers in photobiology have easier access to customized light sources. However, the abundance of different light sources poses new challenges for the correct characterization of existing light conditions. The photobiological effect of a light source depends mainly on the number of photons involved and the spectral composition. However, light sources are mainly described by parameters such as radiant flux, dominant or peak wavelength, and correlated color temperature (CCT). Therefore, in this work, chromatic and white light sources were measured for their spectral composition, various characterization parameters were determined, and the resulting photon flux densities were calculated, focusing on dominant versus peak wavelength for chromatic LEDs and the CCT for white LEDs and fluorescent tubes. The use of the dominant wavelength is inappropriate as it is partly outside the actual spectral range. It was also shown that white light sources with the same CCT have significantly different spectral compositions and, therefore, may have different photobiological effects. The results of this work should serve as a basis for life scientists to better compare light sources, to correctly interpret existing parameters, and to describe light conditions in a standardized and comparable way. [ABSTRACT FROM AUTHOR]

Introduction: Globally, a shift is occurring to recognize the importance of young peoples' health and well-being, their unique health challenges, and the potential they hold as key drivers of change in their communities. In Haiti, one of the four leading causes of death for those 20–24 years old is pregnancy, childbirth, and the weeks after birth or at the end of a pregnancy. Important gaps remain in existing knowledge about youth perspectives of maternal health and well-being within their communities. Youth with lived experiences of maternal near-misses are well-positioned to contribute to the understanding of maternal health in their communities and their potential role in bringing about change. Objectives: To explore and understand youth perspectives of maternal near-miss experiences that occurred in a local healthcare facility or at home in rural Haiti. Methods: We will conduct a qualitative, community-based participatory research study regarding maternal near-miss experiences to understand current challenges and identify solutions to improve community maternal health, specifically focused on youth maternal health. We will use Photovoice to seek an understanding of the lived experiences of youth maternal near-miss survivors. Participants will be from La Pointe, a Haitian community served by their local healthcare facility. We will undertake purposeful sampling to recruit approximately 20 female youth, aged 15–24 years. Data will be generated through photos, individual interviews and small group discussions (grouped by setting of near-miss experience). Data generation and analysis are expected to occur over a three-month period. Ethics and dissemination: Ethics approval will be sought from Centre Médical Béraca in La Pointe, Haiti, and from the Hamilton Integrated Research Ethics Board in Hamilton ON, Canada. We will involve community stakeholders, especially youth, in developing dissemination and knowledge mobilisation strategies. Our findings will be disseminated as an open access publication, be presented publicly, at conferences, and defended as part of a doctoral thesis. [ABSTRACT FROM AUTHOR]

The kinetics of oxidation/reduction of the primary donor of photosystem 1 (PS1) P700, plastocyanin (PC), and ferredoxin (Fd) in the first leaves of barley seedlings under exposure to high-intensity light (2000 μmol∙quanta∙m–2·s–1, 30 min) and elevated temperature (40°C, 3 h) were studied using differential absorption photometry. Exposure to high-intensity light increased the accumulation of the oxidized form of PS1 reaction center P700+, oxidized PC, and reduced Fd. Reduced Fd was not reoxidized under the same conditions on exposure to red and far-red light. The accumulation of P700+, PC+, and Fd – increased in barley seedlings exposed to elevated temperatures. Also, reoxidation of leaf Fd accelerated under red light. Oxidized Fd did not accumulate under far-red light. It was concluded that photo-independent electron flow through Fd under light stress and alternative electron flows involving the plastoquinone pool under heat stress were activated. [ABSTRACT FROM AUTHOR]

Within the circular economy framework in Africa, sustainable waste management can contribute to improving the environment and creating green jobs. However, recycling activities are mostly carried out by informal workers, who are often forgotten in discussions about the circular economy. To ensure the development of a socially just circular economy, their voices must be heard and their needs accounted for. This study took place in Rwanda, a circular economy leader in Africa, and explored the experiences of workers engaged in biowaste recycling, with a particular focus on the distinctions between the experiences of female and male workers. We used photovoice as a methodology, allowing waste workers to visually report on the benefits and drawbacks of being involved in biowaste recycling. Seventeen waste recyclers took pictures representing different working experiences, which was followed by individual in-depth interviews to elicit the meaning behind each picture. Data analysis consisted of a reflexive thematic content analysis of interview transcripts and a participatory data analysis with the workers. The results show that the workers valued their jobs for their social relations at work, being responsible for a task, being productive, and generating savings. Workers negatively highlighted the health risks associated with waste sorting, difficult working conditions, and low salaries. We found gendered differences in workers' marital status and access to paid work opportunities. Although working in waste recycling encompasses occupational risks, this photovoice study highlights that access to work improves workers' relative well-being and that this type of circular economy can help create meaningful jobs. [ABSTRACT FROM AUTHOR]

Increasing occurrences of Microcystis surface scum have been observed in the context of global climate change and the increase in anthropogenic pollution, causing deteriorating water quality in aquatic ecosystems. Previous studies on scum formation mainly focus on the buoyancy-driven floating process of larger Microcystis colonies, neglecting other potential mechanisms. To study the nonbuoyancy-driven rapid flotation of Microcystis, we here investigate the floating processes of two strains of single-cell species (Microcystis aeruginosa and Microcystis wesenbergii), which are typically buoyant, under light conditions (150 mmol photons s-1 m-2). Our results showed that M. wesenbergii exhibited fast upward migration and formed surface scum within 4 hours, while M. aeruginosa did not form visible scum throughout the experiments. To further explore the underlying mechanism of these processes, we compared the dissolved oxygen (DO), extracellular polymeric substance (EPS) content, and colony size of Microcystis in different treatments. We found supersaturated DO and the formation of microbubbles (50-200 µm in diameter) in M. wesenbergii treatments. M. aeruginosa produces bubbles in small quantities and small sizes. Additionally, M. wesenbergii produced more EPS and tended to aggregate into larger colonies. M. wesenbergii had much more derived-soluble extracellular proteins and polysaccharides compared to M. aeruginosa. At the same time, M. wesenbergii contains abundant functional groups, which was beneficial to the formation of agglomerates. The surface scum observed in M. wesenbergii is likely due to micro-bubbles attaching to the surface of cell aggregates or becoming trapped within the colony. Our study reveals a species-specific mechanism for the rapid floatation of Microcystis, providing novel insights into surface scum formation as well as succession of cyanobacterial species. [ABSTRACT FROM AUTHOR]

Vitamin D3 synthesis in human skin is initiated by solar ultraviolet radiation (UVR) exposure of precursor 7-dehydrocholesterol (7DHC), but influence of age on the early stage of vitamin D3 metabolism is uncertain. We performed a prospective standardised study in healthy ambulant adults aged ≥65 and ≤40 years examining (1) if baseline skin 7DHC concentration differs between younger and older adults and (2) the impact of older age on serum vitamin D3 response to solar simulated UVR. Eleven younger (18–40 years) and 10 older (65–89 years) adults, phototype I–III, received low-dose UVR (95% UVA, 5% UVB, 1.3 SED) to ~35% of the body surface area. Biopsies were taken for 7DHC assay from unexposed skin, skin immediately and 24 h post-UVR, and blood sampled at baseline, 24 h and 7 d post-UVR for vitamin D3 assay. Samples were analysed by HPLC-MS/MS. Baseline skin 7DHC (mean ± SD) was 0.22 ± 0.07 and 0.25 ± 0.08 µg/mg in younger versus older adults (no significant difference). Baseline serum vitamin D3 concentration was 1.5 ± 1.5 and 1.5 ± 1.7 nmol/L in younger versus older adults, respectively, and showed a significant increase in both groups post-UVR (no significant differences between age groups). Thus, skin 7DHC concentration was not a limiting factor for vitamin D3 production in older relative to younger adults. This information assists public health guidance on sun exposure/vitamin D nutrition, with particular relevance to the growing populations of healthy ambulant adults ≥65 years. [ABSTRACT FROM AUTHOR]

Kelp communities are experiencing exacerbated heat‐related impacts from more intense, frequent, and deeper marine heatwaves (MHWs), imperiling the long‐term survival of kelp forests in the climate change scenario. The occurrence of deep thermal anomalies is of critical importance, as elevated temperatures can impact kelp populations across their entire bathymetric range. This study evaluates the impact of MHWs on mature sporophytes of Pterygophora californica (walking kelp) from the bathymetric extremes (8–10 vs. 25–27 m) of a population situated in Baja California (Mexico). The location is near the southernmost point of the species's broad distribution (from Alaska to Mexico). The study investigated the ecophysiological responses (e.g., photobiology, nitrate uptake, oxidative stress) and growth of adult sporophytes through a two‐phase experiment: warming simulating a MHW and a post‐MHW phase without warming. Generally, the effects of warming differed depending on the bathymetric origin of the sporophytes. The MHW facilitated essential metabolic functions of deep‐water sporophytes, including photosynthesis, and promoted their growth. In contrast, shallow‐water sporophytes displayed metabolic stress, reduced growth, and oxidative damage. Upon the cessation of warming, certain responses, such as a decline in nitrate uptake and net productivity, became evident in shallow‐water sporophytes, implying a delay in heat‐stress response. This indicates that variation in temperatures can result in more prominent effects than warming alone. The greater heat tolerance of sporophytes in deeper waters shows convincing evidence that deep portions of P. californica populations have the potential to serve as refuges from the harmful impacts of MHWs on shallow reefs. [ABSTRACT FROM AUTHOR]

The work examines the features of light sources influence simulating solar illumination with different spectral composition with a ratio of blue : green : red ranges of 11 : 35 : 54% (AFI-3000), 19 : 38 : 43% (AFI-4000), and 25 : 38 : 37% (AFI-5000) on morphometric, biochemical, photosynthetic, and electrogenic parameters of small radish (Raphanus sativus L.) for photoculture of the 'Peterburgskiy fioletovyy'cultivar. The conducted studies revealed a significant increase in the yield of roots (3.45 kg/m2 for 28 days of growing season), dry matter content up to 8.9% and photosynthetic pigments, reduction in the amount of nitrates to 1206 mg/kg in radish plants illuminated with AFI-5000 spectrum lamps, close to solar radiation at noon. In this variant, an increase in the coefficients of the effective quantum photochemical yield of the PS II photosystem Y (II) = 0.206, photochemical qP = 0.304, and nonphotochemical qN = 0.415 of fluorescence quenching was observed as well as a high generation of potential difference up to 532 mV in the root environment compared to AFI-3000, simulating the light of the sun near the horizon, under which illumination a high proportion of light scattering by the leaf was observed (R800 = 1.716), and AFI-4000 with a spectrum close to morning light. The AFI-4000 option showed the worst result: increased unregulated excitation energy losses Y (NO) = 0.712 and light transmission by the leaf surface of 7.5%. The use of the AFI-5000 light source contributed to obtaining higher indicators characterizing both the yield of plant products and the activity of the photosynthetic apparatus and the intensity of electrogenic processes in the root environment, which makes it possible to recommend a lamp of this type for growing root crops under light culture conditions. This positive effect is likely due to the presence in the spectrum of a greater proportion of blue light, which affects the development of the root system. [ABSTRACT FROM AUTHOR]

Bathy phytochromes are a subclass of bacterial biliprotein photoreceptors that carry a biliverdin IXα chromophore. In contrast to prototypical phytochromes that adopt a red-light--absorbing Pr ground state, the far-red light--absorbing Pfrform is the thermally stable ground state of bathy phytochromes. Although the photobiology of bacterial phytochromes has been extensively studied since their discovery in the late 1990s, our understanding of the signal transduction process to the connected transmitter domains, which are often histidine kinases, remains insufficient. Initiated by the analysis of the bathy phytochrome PaBphP from Pseudomonas aeruginosa, we performed a systematic analysis of five different bathy phytochromes with the aim to derive a general statement on the correlation of photostate and autokinase output. While all proteins adopt different Pr/Pfr-fractions in response to red, blue, and far-red light, only darkness leads to a pure or highly enriched Pfr-form, directly correlated with the lowest level of autokinase activity. Using this information, we developed a method to quantitatively correlate the autokinase activity of phytochrome samples with well-defined stationary Pr/Pfrfractions. We demonstrate that the off-state of the phytochromes is the Pfr-form and that different Pr/Pfr-fractions enable the organisms to fine-tune their kinase output in response to a certain light environment. Furthermore, the output response is regulated by the rate of dark reversion, which differs significantly from 5 s to 50 min half-life. Overall, our study indicates that bathy phytochromes function as sensors of light and darkness, rather than red and far-red light, as originally postulated. [ABSTRACT FROM AUTHOR]

Photoreceptor proteins utilise chromophores to sense light and trigger a biological response. The discovery that adenosylcobalamin (or coenzyme B12) can act as a light-sensing chromophore heralded a new field of B12-photobiology. Although microbial genome analysis indicates that photoactive B12-binding domains form part of more complex protein architectures, regulating a range of molecular–cellular functions in response to light, experimental evidence is lacking. Here we identify and characterise a sub-family of multi-centre photoreceptors, termed photocobilins, that use B12 and biliverdin (BV) to sense light across the visible spectrum. Crystal structures reveal close juxtaposition of the B12 and BV chromophores, an arrangement that facilitates optical coupling. Light-triggered conversion of the B12 affects quaternary structure, in turn leading to light-activation of associated enzyme domains. The apparent widespread nature of photocobilins implies involvement in light regulation of a wider array of biochemical processes, and thus expands the scope for B12 photobiology. Their characterisation provides inspiration for the design of broad-spectrum optogenetic tools and next generation bio-photocatalysts. Photoreceptor proteins utilise biological chromophores to regulate a large range of cellular processes in response to light. Here the authors identify and characterise a sub-family of multi-centre photoreceptors, termed photocobilins, that not only utilise B12 but also contain biliverdin (BV) as an additional chromophore. [ABSTRACT FROM AUTHOR]

Photo elicitation is a powerful data collection tool that involves using photographs within an interview encounter to articulate, expand on and uncover experiences of the social world. Between 2020 and 2022, 41 Muslim immigrant older women between the ages of 54 and 85 were recruited via community liaisons in an Urban Canadian setting to participate in a qualitative descriptive photo elicitation study on social connectedness. We explore methodological and ethical considerations of using photo elicitation in narrative interviews with Muslim older women with a focus on: (1) selection and access to photographs, (2) informed consent, (3) shared meaning-making, (4) politics of a photograph, and (5) digital opportunities within a pandemic. The discussion highlights the ways gender, age and religion intersect to influence decision-making during research activities. [ABSTRACT FROM AUTHOR]

The International Journal of Molecular Sciences has published a special issue on "Materials for Photobiology," which explores the interactions between light and living organisms. The issue includes articles and reviews on the latest advances in light-responsive materials for photobiology, with applications in cancer therapy, microbial infections, aesthetic dentistry, and neurological disorder treatment. The articles cover topics such as nanoprodrugs for combined chemo-photodynamic therapy, selective modulators for breast cancer treatment, bichromophoric systems for bioimaging, and the use of photodynamic therapy for cancer and antimicrobial treatment. The issue also discusses the potential of photobiomodulation therapy in various medical fields, including neurology. The studies published in the journal focus on the use of light-responsive materials in photobiology and related biomedical areas, with the hope of inspiring further developments in the field. [Extracted from the article]

To investigate the knowledge, attitude, and practice (KAP) of photoaging in the Chinese population. This web-based cross-sectional study was conducted between January 2023 and March 2023 among the Chinese population aged 18–80 years old. Participants' knowledge, attitude, and practice toward photoaging were collected through a self-administered questionnaire. A total of 830 questionnaires were collected, with 826 valid questionnaires and an efficiency rate of 99.52%. There were 274 (33.17%) males and 532 (64.41%) aged 31–51 years old. The average knowledge, attitude, and practice scores were 7 (4, 9) (possible range 0–12), 31.5 (28, 34) (possible range 8–40), and 33 (24, 42) (possible range 11–55), respectively, indicating poor knowledge, good attitude, and moderate practice. Spearman correlation analysis showed that knowledge was negatively correlated with attitude (r = − 0.111, P < 0.05) and practice (r = − 0.113, P < 0.05), and attitude was positively correlated with practice (r = 0.992, P < 0.05). The multivariable linear regression model showed that for each point increase in attitude score, the practice score increased by 2.96 points (β = 2.96, 95% CI 2.91–3.01, P < 0.001). The Chinese population has poor knowledge, good attitude, and moderate practice toward photoaging. A good attitude toward photoaging would lead to good practice, and more outreach and education for the Chinese population might be needed. [ABSTRACT FROM AUTHOR]

A variety of inorganic carbon acquisition modes have been proposed in Characean algae, however, a broadly applicable inorganic carbon uptake mechanism is unknown for the genus Chara. In the present study, we analyzed if C. braunii can efficiently use HCO3- as a carbon source for photosynthesis. For this purpose, C. braunii was exposed to different concentrations of NaHCO3- at different time scales. The photosynthetic electron transport through photosystem I (PSI) and II (PSII), the maximum electron transport rate (ETRmax), the efficiency of the electron transport rate (α, the initial slope of the ETR), and the light saturation point of photosynthesis (Ek) were evaluated. Additionally, pigment contents (chlorophyll a, chlorophyll b, and carotenoids) were determined. Bicarbonate addition positively affected ETRmax, after direct HCO3- application, of both PSII and PSI, but this effect seems to decrease after 1 h and 24 h. Similar trends were seen for Ek, but no significant effect was observed for α. Pigment contents showed no significant changes in relation to different HCO3- concentrations. To evaluate if cyclic electron flow around PSI was involved in active HCO3- uptake, the ratio of PSI ETRmax/PSII ETRmax was calculated but did not show a distinctive trend. These results suggest that C. braunii can utilize NaHCO3- in short-term periods as a carbon source but could rely on other carbon acquisition mechanisms over prolonged time periods. These observations suggest that the minor role of HCO3- as a carbon source for photosynthesis in this alga might differentiate C. braunii from other examined Chara spp. [ABSTRACT FROM AUTHOR]

Shade stress is a common problem encountered in turfgrass management situations worldwide. Shade reduces photosynthetic photon flux (PPF), alters light quality, reduces air movement, and may introduce tree root competition. As a species, Kentucky bluegrass (Poa pratensis L.) possesses relatively poor shade tolerance, which limits its use in reduced light environments. However, genetic alteration of the gibberellic acid enzyme pathway has shown promise in some plant species for improving growth in shade. The objective of this 2‐year field study was to determine the comparative performance under reduced PPF and determine minimal daily light integral (DLIm) requirements for acceptable quality of a conventional (CONV) Kentucky bluegrass (KBG) blend and gibberellic acid 2‐oxidase (GA2ox) transformed "ProVista" (PV) KBG. A 2‐year field study was conducted under neutral density shade treatments producing monthly daily light integrals averaging from ∼5.8 (90% shade) to 48 mol m−2 day−1 (full sun) for mid‐June through October study periods. Based on nonlinear regression of mean monthly DLI during the study period versus turfgrass quality (TQ) at the end of each study period, DLIm was found to range from 7.5 to 10 mol m−2 day−1 for PV and from 22.5 to 26.2 mol m−2 day−1 for CONV KBG. Improved TQ of PV under low light intensities may be associated with reduced rates of leaf elongation, greater stand density, higher chlorophyll concentrations, and darker green color compared to CONV KBG. Although shade duration did not exceed 4 months, the results suggest that GA2ox‐transformed PV KBG possesses improved tolerance to reduced PPF compared to CONV KBG. Core Ideas: Limited data are available on minimal light requirements of Kentucky bluegrass cultivars.ProVista shows improved turf quality and color and reduced vertical regrowth relative to conventional under low photosynthetic photon flux.ProVista required minimal daily light integral of 7.5–10 mol m−2 day−1, while conventional Kentucky bluegrass requires 22–26 mol m−2 day−1. [ABSTRACT FROM AUTHOR]

Online discussions tend to be more effective when they are purposefully structured. In this article, we describe how the design of a photo-based protocol influenced community interactions within an online discussion in an undergraduate course. Students were asked to take and share a photo related to a course concept, respond to a peer's photo, and reflect on the comments they received. Discussion posts were coded to identify the three presences (social, cognitive, and teaching) within the Community of Inquiry framework, and student feedback about the experience was analyzed. Findings indicated that the protocol supported all three presences among learners within the community. Cognitive presence was the most frequently exhibited presence, with students exploring concepts from the photos together. In the future, enhancements to the protocol design are proposed to elicit richer interactions and references to course materials. [ABSTRACT FROM AUTHOR]

Nuclides pollution and its biological effects are of great concern, especially for bryophytes during their terrestrial adaptation. Understanding PSII activity and electron transport response is vital for comprehending moss abiotic stress reactions. However, little is known about the photosynthetic performance of moss under nuclide treatment. Therefore, this study aimed to evaluate the chlorophyll fluorescence of Racomitrium japonicum L. The moss was subjected to Sr2+ solutions at concentrations of 5, 50, and 500 mg/L to evaluate chlorophyll a fluorescence using the OJIP test. Moderate and high Sr2+ stress led to inner cell membrane dissolution and reduced chlorophyll content, indicating impaired light energy absorption. At 5 mg/L Sr2+, fluorescence kinetics showed increased light energy capture, energy dissipation, and total photosynthetic driving force, thus stimulating transient photosynthetic activity of PSII and improving PSI reduction. Linear electron transfer and PSII stability significantly decreased under moderate and high Sr2+ stress, indicating potential photosynthetic center damage. Cyclic electron transfer (CEF) alleviated photosynthetic stress at 5 mg/L Sr2+. Thus, low Sr2+ levels stimulated CEF, adjusting energy flux and partitioning to protect the photosynthetic apparatus. Nevertheless, significant damage occurred due to inefficient protection under high Sr2+ stress. [ABSTRACT FROM AUTHOR]

Coriander (Coriandrum sativum L.) is prized for its aroma and medicinal properties and is extensively employed in various cuisines. Light intensity and photoperiod greatly impact its phenological development. The application of light-emitting diodes (LEDs) in facility cultivation systems enables precise control of lighting conditions, leading to enhanced energy efficiency in coriander cultivation. This study investigated three levels of light intensity (133, 200, and 400 μmol·m−2·s−1) and three photoperiods (8L/16D, 16L/8D, and 24L) to comprehensively assess their effects on coriander's morphological development, photosynthetic characteristics, and energy utilization efficiency. The objective was to identify a combination conducive to efficient and energy-saving coriander cultivation in PFALs. Results indicated that high light intensity (400 μmol·m−2·s−1) with continuous lighting (24L) reduces coriander's photosynthetic capacity, while 24-h of continuous lighting can boost yield at the expense of energy efficiency. An 8-h photoperiod significantly decreases the yield compared to 16 h. Low light intensity inhibits plant development, indicating that 133 μmol·m−2·s−1 is suboptimal. For optimal efficiency and yield, a light intensity of 200 μmol·m−2·s−1 and a 16-h photoperiod are recommended in coriander PFAL cultivation. These findings advocate for the adoption of these specific conditions for the indoor cultivation of coriander within PFAL systems. [ABSTRACT FROM AUTHOR]

This paper describes three datasets which include 443 folders and approximately 4430 images. The images were obtained from the interior of a 1:50 scale model using a fisheye camera connected to a Raspberry Pi microcomputer. This dataset aims to analyze the photobiological effects (visual and non-visual) of the interplay between coloured surfaces and different types of lighting strategies. The experiments were conducted under three types of light sources: simulated daylight through a mirror-box artificial sky simulator, direct daylight, and an electric lighting system that allows for colour temperature modification. This dataset includes low dynamic range images to generate high dynamic range images, which in turn can be used to plot false colour maps concerning photopic luminance, melanopic luminance, CCT of an image, M/P ratio, and brightness distribution maps. This dataset can be useful for architects, interior designers, and building engineers to integrate lighting and colour strategies according to the visual and non-visual needs of the users. This research was partially used in the research of Espinoza-Sanhueza et al. [1,2]. The datasets are published and shared through a Mendeley repository [3].

Abstract Photobiomodulation (PBM) has emerged as a rapidly growing and innovative therapeutic method for various illnesses in recent years. Due to the irreversible nature of Parkinson's disease (PD), it has proven challenging to impede or postpone the progression of the disease. Despite research on pharmacological approaches to halt neuronal degeneration, the viability of these techniques has been called into doubt due to apprehensions over potential side effects and the ethical implications associated with the utilization of embryonic cell transplantation. Hence, developing an innovative therapeutic approach to halting neuronal degeneration and safeguarding neurons from this neurodegenerative disorder is imperative. This review examines the pathogenesis, challenges, and limitations of conventional PD therapies, allowing a closer examination of PBM's distinctive approach within this medical context. Delving into PBM's therapeutic mechanisms in the cells, the effects of different wavelengths on cell therapies in PD patients, and considerations for patient care administration to overcome traditional challenges, this study offers insights into its potential as a promising avenue for PD management.

The sea ice spring bloom is crucial for sustaining Arctic marine food webs, with sea ice algae serving as primary carbon sources for higher trophic levels. Despite the prevailing dominance of diatom species in sea ice spring blooms, our study highlights a notable deviation, showcasing a bloom driven by dinoflagellates. Through field sampling of first-year sea ice cores and subsequent analysis of physical and biogeochemical parameters, combined with amplicon sequencing of the 18S rRNA gene, we investigated the occurrence and implications of this significant dinoflagellate bloom, with a particular focus on Polarella glacialis. Our findings reveal that high irradiances at the top of the ice core, coupled with elevated nutrient availability and warm ice conditions, are key drivers of this phenomenon, as elucidated by redundancy analysis. Moreover, our results suggest a potential climate-driven decline in snow cover on sea ice, increased open leads, and thinner sea ice, which may favor the proliferation of dinoflagellates over diatoms. This alternative dinoflagellate-dominated bloom could have profound ecological consequences, given the enriched omega-3 fatty acid content of dinoflagellates, thereby influencing energy transfer within the Arctic marine food web. Furthermore, our study identifies the presence of not only Polarella glacialis but also Chytridinium, an ectoparasite on copepod eggs, and the green algae Ulothrix in relatively high abundances within the sea ice. These findings shed light on the intricate interplay between environmental factors and microbial community dynamics within Arctic sea ice ecosystems.

We present a partially linearized method based on spin-mapping for computing both linear and nonlinear optical spectra. As observables are obtained from ensembles of classical trajectories, the approach can be applied to the large condensed-phase systems that undergo photosynthetic light-harvesting processes. In particular, the recently derived spin partially linearized density matrix method has been shown to exhibit superior accuracy in computing population dynamics compared to other related classical-trajectory methods. Such a method should also be ideally suited to describing the quantum coherences generated by interaction with light. We demonstrate that this is, indeed, the case by calculating the nonlinear optical response functions relevant for the pump–probe and 2D photon-echo spectra for a Frenkel biexciton model and the Fenna–Matthews–Olsen light-harvesting complex. One especially desirable feature of our approach is that the full spectrum can be decomposed into its constituent components associated with the various Liouville-space pathways, offering a greater insight beyond what can be directly obtained from experiments. [ABSTRACT FROM AUTHOR]

Transient absorption spectroscopy (TAS) is a time‐resolved spectroscopic technique that can quantitatively observe temporal changes in the absorption spectrum associated with transient species, such as excitons and charges. Therefore, it is extensively used in photophysics, photochemistry, and photobiology. TAS plays a crucial role in unveiling charge generation and recombination dynamics in organic solar cells (OSCs). However, the interpretation of TA data is sometimes difficult for those who are not familiar with TAS. In this Perspective, therefore, the utility of TAS is briefly explained in studying OSCs and highlight key considerations for interpreting TA data. Measuring TA data at appropriate excitation fluence and appropriate spectral assignment are essential to correctly interpret photophysics of OSCs. With this Perspective, it aims to offer readers sufficient advice to enable them to perform TA measurements appropriately and interpret the TA data correctly. [ABSTRACT FROM AUTHOR]

Chronic diabetic wounds are at lifelong risk of developing diabetic foot ulcers owing to severe hypoxia, excessive reactive oxygen species (ROS), a complex inflammatory microenvironment, and the potential for bacterial infection. Here we develop a programmed treatment strategy employing live Haematococcus (HEA). By modulating light intensity, HEA can be programmed to perform a variety of functions, such as antibacterial activity, oxygen supply, ROS scavenging, and immune regulation, suggesting its potential for use in programmed therapy. Under high light intensity (658 nm, 0.5 W/cm2), green HEA (GHEA) with efficient photothermal conversion mediate wound surface disinfection. By decreasing the light intensity (658 nm, 0.1 W/cm2), the photosynthetic system of GHEA can continuously produce oxygen, effectively resolving the problems of hypoxia and promoting vascular regeneration. Continuous light irradiation induces astaxanthin (AST) accumulation in HEA cells, resulting in a gradual transformation from a green to red hue (RHEA). RHEA effectively scavenges excess ROS, enhances the expression of intracellular antioxidant enzymes, and directs polarization to M2 macrophages by secreting AST vesicles via exosomes. The living HEA hydrogel can sterilize and enhance cell proliferation and migration and promote neoangiogenesis, which could improve infected diabetic wound healing in female mice. The treatment of infected diabetic wounds faces obstacles of bacterial infection, hypoxia, hyperexpression of reactive oxygen species, and inflammation. Here, the authors address these issues by developing a programmed treatment strategy that utilizes live Haematococcus to promote healing of diabetic wounds in a comprehensive manner. [ABSTRACT FROM AUTHOR]

Over the last decade, the development of time‐resolved serial crystallography (TR‐SX) at X‐ray free‐electron lasers (XFELs) and synchrotrons has allowed researchers to study phenomena occurring in proteins on the femtosecond‐to‐minute timescale, taking advantage of many technical and methodological breakthroughs. Protein crystals of various sizes are presented to the X‐ray beam in either a static or a moving medium. Photoactive proteins were naturally the initial systems to be studied in TR‐SX experiments using pump–probe schemes, where the pump is a pulse of visible light. Other reaction initiations through small‐molecule diffusion are gaining momentum. Here, selected examples of XFEL and synchrotron time‐resolved crystallography studies will be used to highlight the specificities of the various instruments and methods with respect to time resolution, and are compared with cryo‐trapping studies. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to investigate the differences of photosynthetic physiological characteristics of different varieties (strains), which will provide a theoretical basis for high photosynthesis efficiency breeding and application in Chinese chestnut [Methods] Six Chinese chestnut varieties of Castanea mollissima Yanbao, C. mollissima 'Yanqiu, C. mollissima Yanchang, C. mollissima Yanjia, C. mollissima Qianxi 37, and C. mollissima Hybrid 22 were used as the materials. Using the portable photosynthesis system Li-6400, we measured the photosynthetic characteristics and diurnal variation of leaf samples of six different chestnut varieties or strains. We fitted the light response curves and photosynthetic parameters using the leaf floating model. Additional- ly, we determined the chlorophyll content in the leaves using a UV-visible spectrophotometer. [Results] Among the six chestnut varieties or strains, 'Yanqiu' ex hibited a significantly higher photosynthetic light saturation point (PLSP) compared to other five varieties, and 'Hybrid 22 ranked second, indicating that these two varieties had the strongest adaptation to high light intensity. The photosynthetic light compensation point (PLCP) of 'Yanchang was significantly higher than other five varieties, and "Qianxi 37" ranked second, indicating that these two varieties had the strongest adaptation to low ligat intensity. Additionally, they exhibited higher chlorophyll content and maintained good photosynthetic characteristics even in shaded environments with weak light stress. Varieties 'Yanbao' and 'Yanjia showed higher PLSP and lower PLCP, indicating that these two varieties have a wider range of adaptation to light intensity. They were capable of efficiently utilizing light across a broader spectrum of intensities. Yanqiu had the highest maximum net photosynthetic rate (Pn, max) and the lowest dark respiration rate (Rd), along with the highest chlorophyll content. It indicated that 'Yanqiu' has strong photosynthetic capacity and organic matter accumulation ability. It also had the highest PLSP, enabling it to fully utilize the high light environment of the Yanshan Mountains and possessed high light efficiency characteristics. The Pn, max of Yanqiu was significantly higher than other varieties. Hybrid 221 and Yanbao' also exhibited significantly higher P mos compared with 'Yanjia and Qianxi 37 chang had the lowest Pn, max- The order of Pn, max, among the six chestnut varieties or strains was as follows: 'Yanqiu' 'Hybrid 22 Yanbao' > 'Yanjia > Qianxi 371> 'Yanchang. [ABSTRACT FROM AUTHOR]

The identification of bleaching tolerant traits among individual corals is a major focus for many restoration and conservation initiatives but often relies on large scale or high-throughput experimental manipulations which may not be accessible to many front-line restoration practitioners. Here, we evaluate a machine learning technique to generate a predictive model which estimates bleaching severity using non-destructive chlorophyll-a fluorescence photo-physiological metrics measured with a low-cost and open access bio-optical tool. First, a 4-week long thermal bleaching experiment was performed on 156 genotypes of Acropora palmata at a land-based restoration facility. Resulting bleaching responses (percent change in Fv/Fm or Absorbance) significantly differed across the four distinct light-response phenotypes (clusters) generated via a photo-physiology-based dendrogram, indicating strong concordance between fluorescence-based photo-physiological metrics and future bleaching severity. The proportion of thermally tolerant Clade D symbionts also differed significantly across photo-physiology-based dendrogram clusters, linking light-response phenotypes and bleaching response with underlying symbiont species. Next, these correlations were used to train and then test a Random Forest algorithm-based model using a bootstrap resampling technique. Correlation between predicted and actual bleaching responses in test corals was significant (p < 0.0001) and increased with the number of corals used in model training (Peak average R2 values of 0.45 and 0.35 for Fv/Fm and absorbance, respectively). Strong concordance between photo-physiology-based phenotypes and future bleaching severity may provide a highly scalable means for assessing reef corals. [ABSTRACT FROM AUTHOR]

Human-induced climate change is causing ocean warming that triggers the breakdown of the coral–algal symbiosis. The proximate cause of this phenomenon, known as coral bleaching, is commonly attributed to the overproduction of reactive oxygen species (ROS) by the thermally stressed photosynthetic algal symbionts. However, direct evidence that algal ROS production (e.g., in the form of H2O2) and coral physiological stress are the ultimate cause of bleaching remains ambiguous. Here, we investigated the temporal dynamics of H2O2 and oxygen (O2) concentrations during thermally induced coral bleaching to disentangle cause from consequence. Microsensors at the tissue interface of Pocillopora damicornis measured H2O2 and O2 concentrations while exposing single nubbins to baseline temperatures (30 °C) and to minor (33 °C), moderate (36 °C), and high (39 °C) levels of acute heat stress using the Coral Bleaching Automated Stress System (CBASS). We show that a temporary decline in O2 concentration, accompanied by a declining photosynthetic efficiency and loss of Symbiodiniaceae and pigmentation, is the initial response to moderate thermal stress. This response was neither provoked nor followed by an increased H2O2 concentration at the coral tissue interface. A steady light-independent increase of H2O2 was only detected during high heat stress, resulting in the complete and permanent loss of photosynthetic activity. Our findings do not support a direct connection between algal photodamage and an increase in H2O2 concentration during thermally induced bleaching and suggest that more research on the function of H2O2 is warranted. This notion is further substantiated by the observation of an additional source of H2O2, likely oxidative bursts, that were common at the baseline temperature and under minor heat stress, while their occurrence decreased at moderate and high heat stress. Resolving the multifaceted and dynamic roles of H2O2 in coral bleaching is critical to better understand the response of the coral holobiont to thermal stress and identifying the processes underlying the breakdown of the coral–algal symbiosis. [ABSTRACT FROM AUTHOR]

Natural photosynthetic biosystems, with elaborate spatial structures, possess substantial specific surface areas and strong light-scattering abilities and provide a blueprint for the fabrication of photocatalysts for efficiently capturing and utilizing solar energy. However, mimicking sophisticated natural structures by a rational design is a great challenge. Herein, we report a facile and universal symbiosis hydrothermal synthesis strategy for obtaining biomimetic volvox-like double-core nested hollow materials. The nested hollow materials possessed the special notched "mother–twin" core–shell structure and the core numbers could be well controlled by adjusting the amount of precursor. The notched double-core hollow ZnO/CdS (mother–twin HZC) was facilely constructed by the direct chemical deposition of CdS nanosheets on the double-core hollow ZnO (mother–twin HZ). The notched complex spatial heterostructure possessed a multiple light-reflection capability (improving the utilization of solar energy), tight interfacial contact (favoring charge migration), and a high surface-to-volume ratio (providing sufficient active sites for H2 production). Both the Z-scheme ZnO/CdS heterostructures and the special nested hollow structure could synergistically enable achieving a remarkable hydrogen generation rate (up to 18.70 mmol g−1 h−1) under visible-light irradiation, exceeding that of the reported similar ZnO/CdS heterostructure without co-catalysts. [ABSTRACT FROM AUTHOR]

Macroalgal growth and yield are key to sustainable aquaculture. Although light and water turbulence are two important factors that affect algal productivity, research on their interaction is limited. Therefore, in this study, we investigated the effects of different wavelengths of light and the presence or absence of water turbulence on the growth of the green macroalga Ulva australis. Water turbulence was found to enhance the growth of U. australis irrespective of photosynthetic performance, but only in blue light cultures. The quantum dose of blue light required to induce 50% growth promotion was 1.02 mol m−2, which is comparable to the reported values for cryptochrome-mediated effects in other macroalgae. The combined effect of blue light and water turbulence led to the accumulation of photosynthesis-related proteins that support plastid differentiation and facilitate efficient photosynthesis and growth. Our findings thus highlight the potential of harnessing blue light and water turbulence to maximise macroalgal cultivation for sustainable and profitable algal aquaculture. [ABSTRACT FROM AUTHOR]

The mat-forming fruticose lichens Cladonia stellaris and Cetraria islandica frequently co-occur on soils in sun-exposed boreal, subarctic, and alpine ecosystems. While the dominant reindeer lichen Cladonia lacks a cortex but produces the light-reflecting pale pigment usnic acid on its surface, the common but patchier Cetraria has a firm cortex sealed by the light-absorbing pigment melanin. By measuring reflectance spectra, high-light tolerance, photosynthetic responses, and chlorophyll fluorescence in sympatric populations of these lichens differing in fungal pigments, we aimed to study how they cope with high light while hydrated. Specimens of the two species tolerated high light equally well but with different protective mechanisms. The mycobiont of the melanic species efficiently absorbed excess light, consistent with a lower need for its photobiont to protect itself by non-photochemical quenching (NPQ). By contrast, usnic acid screened light at 450–700 nm by reflectance and absorbed shorter wavelengths. The ecorticate usnic species with less efficient fungal light screening exhibited a consistently lower light compensation point and higher CO2 uptake rates than the melanic lichen. In both species, steady state NPQ rapidly increased at increasing light with no signs of light saturation. To compensate for less internal shading causing light fluctuations with a larger amplitude, the usnic lichen photobiont adjusted to changing light by faster induction and faster relaxation of NPQ rapidly transforming excess excitation energy to less damaging heat. The high and flexible NPQ tracking fluctuations in solar radiation probably contributes to the strong dominance of the usnic mat-forming Cladonia in open lichen-dominated heaths. [ABSTRACT FROM AUTHOR]

This study reports valuable information regarding the presence and concentration of a series of photoactive β‐carboline (βCs) alkaloids (norharmane, harmane, harmine, harmol, harmaline, and harmalol) and their distribution across the floral age and organs of Passiflora caerulea. UHPLC–MS/MS data reported herein reveal that the βCs' content ranged from 1 to 110 μg kg−1, depending on the floral organ and age. In certain physiologically relevant organs, such as anthers, βCs' content was one order of magnitude higher than in other organs, suggesting a special role for βCs in this specific organ. βCs' content also varied in a structure‐dependent manner. Alkaloids bearing a hydroxyl group at position C(7) of the main βC ring were present at concentrations one order of magnitude higher than other βC derivatives investigated. UV–visible and fluorescence spectroscopy of the flower extracts provided complementary information regarding other biologically relevant groups of chromophores (phenolic/indolic derivatives, flavonoids/carotenes, and chlorophylls). Since flowers are constantly exposed to solar radiation, the presence of photoactive βCs in floral organs may have several (photo)biological implications that are further discussed. [ABSTRACT FROM AUTHOR]

Background: Photoprotection is crucial in preventing the development and progression of various skin diseases. However, patients with skin disease have limited awareness of photoprotection. We evaluated the knowledge and behavioral patterns of photoprotection among Koreans with skin diseases. Methods: A cross‐sectional study was conducted in 11 general hospitals across South Korea. The study population consisted of patients aged 19 years or older who visited dermatologic clinics for their skin diseases. A self‐administered questionnaire was used to collect patient demographics, knowledge of photoprotection, and photoprotective habits. Results: In this study, 1173 patients with skin cancer, hyperpigmentary disorders, hypopigmentary disorders, or other skin diseases participated. Females scored significantly higher in knowledge of photoprotection compared to males (mean score 8.4 vs. 7.8; p <.001), and younger patients (<50 years) scored higher than older patients (mean score 8.7 vs. 7.5; p <.001). Males also reported longer sun exposure times and lower usage of photoprotective measures (both p <.001). Patients with skin cancer had the lowest mean knowledge score (7.1 ± 2.6) and were less likely to use photoprotective measures compared to other groups (p <.001). In contrast, patients with hyperpigmentation actively avoided sun exposure compared with other groups (p < 0.001). Conclusions: Knowledge of photoprotection among Korean patients with skin diseases varied depending on the gender, age, and type of skin disease. Their photoprotective behaviors were inadequate, especially among males and those with skin cancer. These findings emphasize the importance of educating and tailoring photoprotection strategies for patients with skin diseases. [ABSTRACT FROM AUTHOR]

Background/Purpose: Exposure to sunlight has been shown to cause pigmentary alterations, photoaging and photocarcinogenesis. Understanding photoprotective patterns in adolescent populations is beneficial to public health initiatives. We utilized data provided by the American College Health Association's National College Health Assessment to evaluate photoprotective behaviors among adolescent populations. Methods: Behavioral questions related to photoprotection were analyzed from the American College Health Association (ACHA) National College Health Assessment (NCHA) (Version III). Results: When comparing races, Black/African American respondents had the lowest association of practicing photoprotective behaviors in comparison to white respondents (p <.05). When comparing US geographic regions, the south had the lowest association of photoprotective measures (p <.05). Limitations: The response rate of each institution varied, although there was still a large quantity of respondents. Finally, we cannot discern the specific reasoning for adolescent populations not using sunscreen. Conclusion: These data identify demographics where efforts to enhance education on photoprotective behaviors, specifically among skin of color and southern population, to support public health initiatives. [ABSTRACT FROM AUTHOR]

Objective: This survey aimed to evaluate knowledge of photoprotection among individuals from a random group in a resort town in Poland, Kołobrzeg, and explore the correlation between their knowledge and demographics like age, gender, education, and residence. Methods: An anonymous survey was conducted among a diverse group. This population comprised individuals from various backgrounds: health spa patients undergoing treatments, therapies and medical appointments, guests visiting the resort for leisure, passersby, and staff working at the spa and recreational facilities. The survey was designed by authors, encompassed 16 questions about knowledge on photoprotection, sunscreen use and related topics, and gathered demographic data. Responses from 142 individuals were statistically analyzed using PQStat Software. Results: Only 7.7% use sunscreen all year‐round. The majority apply sun protection factor (SPF) creams on sunny days or with prolonged sun exposure. Over half of the respondents (53.5%) are aware when to apply sunscreen but 43% reapply it less than every 4 h. 25.4% do not reapply at all. 38.7% think protection provided by higher SPF means longer sun exposure time. Over 50% believe SPF 30 offers double the protection of SPF 15. Almost half (46.8%) use extra sun protection, like sunglasses or hats. Significant correlations exist between education/age and certain survey responses. Conclusions: The findings emphasize the urgency to improve photoprotection knowledge in the Polish population, particularly regarding the year‐round harmful solar effects and the correct use of sun protection products. [ABSTRACT FROM AUTHOR]

Through plasmon resonance, silver and gold nanoparticles can selectively backscatter light within different regions of the visible electromagnetic spectrum. We engineered a plasmonic film technology that utilizes gold and silver nanoparticles to enhance light at the necessary wavelengths for microalgal photosynthetic activities. Nanoparticles were embedded in a polymeric matrix to fabricate millimeter-thin plasmonic films that can be used as light filters in microalgal photobioreactors. Experiments conducted with microalga Chlamydomonas reinhardtii proved that microalgal growth and photosynthetic pigment production can be increased by up to 50% and 78%, respectively, by using these plasmonic film light filters. This work provides a scalable strategy for the efficient production of specialty chemicals and biofuels from microalgae through irradiation control with plasmonic nanoparticles. [ABSTRACT FROM AUTHOR]

Sustainable approaches to circular economy in animal agriculture are still poorly developed. Here, we report an approach to reduce gaseous emissions of CO2 and NH3 from animal housing while simultaneously using them to produce value-added biomass. To this end, a cone-shaped, helical photobioreactor was developed that can be integrated into animal housing by being freely suspended, thereby combining a small footprint with a physically robust design. The photobioreactor was coupled with the exhaust air of a chicken house to allow continuous cultivation of a mixed culture of Arthrospira spec. (Spirulina). Continuous quantification of CO2 and NH3 concentration showed that the coupled algae reactor effectively purifies the exhaust air from the chicken house while producing algal biomass. Typical production rates of greater than 0.3 g/l*day dry mass were obtained, and continuous operation was possible for several weeks. Morphological, biochemical, and genomic characterization of Spirulina cultures yielded insights into the dynamics and metabolic processes of the microbial community. We anticipate that further optimization of this approach will provide new opportunities for the generation of value-added products from gaseous CO2 and NH3 waste emissions, linking resource-efficient production of microalgae with simultaneous sequestration of animal emissions. Key points: • Coupling a bioreactor with exhaust gases of chicken coop for production of biomass. • Spirulina mixed culture removes CO2 and NH3 from chicken house emissions. • High growth rates and biodiversity adaptation for nitrogen metabolism. Towards a sustainable circular economy in livestock farming. The functional coupling of a helical tube photobioreactor with exhaust air from a chicken house enabled the efficient cultivation of Spirulina microalgae while simultaneously sequestering the animals' CO2 and NH3 emissions. [ABSTRACT FROM AUTHOR]