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Light-emitting diode (LED) lighting is currently the most energy-efficient lighting technology, and its use in agriculture is rapidly increasing. This research aimed to investigate the interaction effect of nutrient solution concentration and light quality on tomato seedlings growth. The tested factors included two nutrient solution concentrations (50% and 33% Hoagland solution) and four ratios of blue (440 nm) to red (660 nm) light in LED lighting at a constant light intensity (B2R1, B1R1, B1R2, and B1R3). Height growth was greatest in the 33% nutrient solution × B1R2 light treatment and smallest in the 33% nutrient solution × B2R1 light treatment. Regardless of the nutrient solution concentration, total chlorophyll and carotenoid concentrations decreased with an increase in the proportion of blue light. Plant absorption of sulfur was highest in the 50% nutrient solution × B1R2 light treatment, significantly higher than all other treatments. Although the 50% nutrient solution × B1R2 light treatment also showed the greatest magnesium absorption, it did not differ significantly from most of the other treatments. In general, for growing tomato seedlings, a high ratio of blue light regime (B2R1) with a dilute nutrient solution, enriched with magnesium and sulfur, can be recommended to prevent elongation disorder and have no negative impact on various growth and physiological indicators. [ABSTRACT FROM AUTHOR]

Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase affects bone health in 396 Hy-line W36 hens assigned to control (C) or treatment groups (W1 and W2). All hens received 16 h of light and 8 h of darkness daily in different variations of scotophase interruption. Blood samples were taken at weeks 20, 30, 50, and 70, serum calcium was measured during darkness at two timepoints (SRT and END), and bone demineralization markers were examined using enzyme concentrations (TRACP-5b and CTX-I). Across weeks, tibias were CT-scanned for density (mg/cm3) and area (mm2), then used for breakage strength analysis (N) and ash%. No SRT Ca level differences emerged, but C hens had lower END Ca levels compared to W1 and W2 hens across all weeks, while W1 and W2 hens showed no significant differences. C hens displayed higher TRACP-5b and CTX-I concentrations across all weeks compared to W1 and W2 (all p ≤ 0.05). At week 70, C hens had the lowest cortical bone cross-sectional area and mineral density compared to W1 and W2 (all p ≤ 0.05). Tibiotarsi bone breakage strength was lower in C hens compared to W1 and W2. C hens had significantly lower ash% than treatment birds. Interrupting the scotophase period improved overall bone health in Hy-line W36 laying hens.

In urbanised areas, marine infrastructure alters natural light regimes, creating habitats that are permanently shaded, affecting the community structure of settling and resident biota. While applications of artificial lights have been suggested to minimise impacts of shading or manipulate community composition for specific aims (e.g. carbon capture, biosecurity), their use has not been evaluated. We used two field experiments to test the effect of artificial light of low (1 × 20,000 lumen light) and high (3 × 20,000 lumen light or 1 × 66,000 lumen light) intensities (7 AM–7 PM on–off cycle) on benthic communities on marine infrastructure. Specifically, we assessed whether artificial lights (i) led to the development of communities similar to those under natural light conditions, (ii) enhanced the abundance of algae and discouraged invertebrates (functional groups that are inversely impacted by shade) and whether (iii) the extent to which artificial lights impact marine communities varies across environmental settings (high and low turbidity) where natural light availability differs. Impacts were assessed on new (two sites) and established communities (one site). We also assessed the effect of artificial light on predation/herbivory pressure using a caging experiment at the low turbidity site. For new communities developing on bare substrate in low turbidity conditions, low intensity artificial light resulted in similar communities to bare substrate exposed to natural light levels. High intensity artificial light increased algal cover beyond communities developing in natural light. Caging increased the cover of algae and invertebrates across all treatments. In turbid locations, artificial light (high and low) increased algal abundance, though to a lesser extent. The addition of artificial light had limited effects on established benthic communities. Synthesis and applications. Our experiments indicate that artificial lights can be effective in reversing effects of shading, but that targeted outcomes (e.g. increased algal or reduced invertebrate cover) are limited to bare substrates and low turbidity environments where more light is available, and algae are naturally abundant. [ABSTRACT FROM AUTHOR]

AbstractDespite the lengthy history of saffron cultivation in Iran, the reliance on traditional methods persists and falls short of meeting the growing market demand. Greenhouse technologies and hydroponic cultivation provide a solution by boosting stigma production, reducing labor, and addressing climatic challenges. An experiment was conducted in 2019 at the research greenhouses of Shahed University to examine the impact of artificial light intensities and nutrient concentrations on the quantitative and qualitative performance of saffron under hydroponic conditions. The study followed a split-plot scheme based on a completely randomized design. The main factor involved varying white light intensities (2, 4, 8, and 16 mol.m−2.d−1), while the subfactor included different Hoagland nutrient solution concentrations (0.75, 1.4, and 2.8 dS.m−1). Results showed that optimal conditions (light intensity up to 8 mol.m−2.d−1 and nutrient concentrations of 0.75 to 1.4 dS.m−1) led to a 3.64-fold increase in saffron flower yield and a 2.09-fold increase in stigma dry weight. These treatments also significantly enhanced crocin, picrocrocin, and safranal content, improving the spice’s quality by 5.43, 10.30, and 8.22 times, respectively. Light intensity significantly influenced the weight of the mother corm, while nutrient concentration did not, although consistent nutrition combined with higher light intensity increased the mother corm’s diameter. These findings highlight the effectiveness of using light intensities up to 8 mol.m−2.d−1 and Hoagland nutrient concentrations of 0.75 to 1.4 dS.m−1 for hydroponic saffron cultivation in greenhouses. [ABSTRACT FROM AUTHOR]

Fish behavior is important to consider when developing selective fishing gear. In studies designed to investigate the size selective properties of towed fishing gears such as trawls, fish behavior is mainly documented by underwater video recordings. Because fishing gear can be operated at great depths or in other low light environments, artificial light is often required for underwater recordings. However, artificial light can influence fish behavior, which casts doubt on the validity of behavioral observations obtained in the presence of artificial light. However, removing artificial light disables video recordings and the possibility to study fish behavior in relation to selectivity devices towed fishing gears in low light environments. To date, little is known about the extent to which artificial light used for video observations affects fish behavior with respect to fishing gear. Therefore, we conducted fishing trials in the Barents Sea demersal trawl fishery to assess the effect of light sources on fish behavior by using size selectivity results in towed fishing gears. We found that the behavior of cod (Gadus morhua) was unaffected by the light sources, whereas the behavior of haddock (Melanogrammus aeglefinus), saithe (Pollachius virens) and redfish (Sebastes spp.) significantly changed when red light and white light were employed. Our results also demonstrated significant differences in fish behavior between white and red light. [ABSTRACT FROM AUTHOR]

Rosmarinic acid is a metabolite that improves cognitive function and may prevent the development of Alzheimer's disease. The long-term continuous cultured calli of the extreme halophytic plant Mertensia maritima L. (Boraginaceae) constitute a source of rosmarinic acid. However, the biosynthetic activity of this calli culture gradually decreased over 12 years of continuous cultivation. In this work, we have shown that this process can be overcome by using monochromatic light, especially green light, in the wavelength range of 510–520 nm. In recent years, LEDs (light-emitting diodes) have been the subject of research within the fields of plant growth, development, and phytochemical biosynthesis. As determined by HPLC–DAD-ESI-HRMS, when this culture was exposed to normal (100 µmol m−2 s−1) or moderate (300 µmol m−2 s−1) green light, the content of rosmarinic acid increased by 2 and 3.5 times, respectively. A green light-induced increase in the content of rosmarinic acid was accompanied by the inhibition of the biosynthesis of glucosides of coumaric and ferulic acid, which are also produced in long-term cultured calli of M. maritima. Thus, monochromatic light can be used to increase the biosynthetic capacity of callus cultures during long-term cultivation.Key message: Exposure of the long-term cultivated callus culture of M. maritima under green light with moderate (300 µmol m−2 s−1) intensities provided the highest productivity of 12-year-old M. maritima, equal to the productivity of the initial calli. [ABSTRACT FROM AUTHOR]

The sweet basil Ocimum basilicum L. is the subject of numerous studies and is cultivated as a food and ornamental plant. Moreover, O. basilicum could be useful in the prevention of stroke ischemia, and its anticancer properties were recently shown. Caffeic acid derivatives, such as rosmarinic acid (RA), chicoric acid, salvianolic acids, and anthocyanins, provide the medicinal properties of basil. Therefore, investigations of the optimal growth conditions that can provide cost-effective cultivation of highly productive basil plants are relevant and important. The aim of the present work was to study the effects of a combination of soil composition and light conditions on the morphological and biochemical characteristics of O. basilicum. In totally artificial (indoor) environments, light-emitting diodes (LEDs) may provide a broad range of narrowband wavelengths with different intensities. This technology can lower operating costs. In addition to the spectral composition, light intensity (PPFD, µmol m−2s−1) is an important parameter for the optimal growth of plants. In the experiment, we used different spectra of LED lamps with intensities of 300 µmol m−2s−1: warm white, monochromatic (green and red), and a combination of blue and red. Plants were grown under various lighting conditions in soil supplemented with fertilizer, Z-ion, and Crystallon. The results showed that supplementation of soil with Crystallon had a greater effect on the growth of both above- and below-ground parts of O. basilicum plants. Interestingly, growing O. basilicum plants under R and RB light led to a 2-fold increase in the biosynthesis of both the key caffeic acid derivative RA and anthocyanin. However, given that under RB light, there is no positive effect of Crystallon on growth, the productivity of RA and anthocyanin reached a maximum when O. basilicum plants were grown under R light and Crystallon. Under these conditions, the productivity of anthocyanins and caffeic acid derivatives in O. basilicum was more than eight times greater than that in untreated O. basilicum plants. [ABSTRACT FROM AUTHOR]

Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase affects bone health in 396 Hy-line W36 hens assigned to control (C) or treatment groups (W1 and W2). All hens received 16 h of light and 8 h of darkness daily in different variations of scotophase interruption. Blood samples were taken at weeks 20, 30, 50, and 70, serum calcium was measured during darkness at two timepoints (SRT and END), and bone demineralization markers were examined using enzyme concentrations (TRACP-5b and CTX-I). Across weeks, tibias were CT-scanned for density (mg/cm3) and area (mm2), then used for breakage strength analysis (N) and ash%. No SRT Ca level differences emerged, but C hens had lower END Ca levels compared to W1 and W2 hens across all weeks, while W1 and W2 hens showed no significant differences. C hens displayed higher TRACP-5b and CTX-I concentrations across all weeks compared to W1 and W2 (all p ≤ 0.05). At week 70, C hens had the lowest cortical bone cross-sectional area and mineral density compared to W1 and W2 (all p ≤ 0.05). Tibiotarsi bone breakage strength was lower in C hens compared to W1 and W2. C hens had significantly lower ash% than treatment birds. Interrupting the scotophase period improved overall bone health in Hy-line W36 laying hens. [ABSTRACT FROM AUTHOR]

California‐based architectural educator Bryan Cantley has pursued the analogy of the machine consistently since his days as a student in Los Angeles. Over the last few decades, he has developed an instantly recognisable style, as he investigates the interstices of the virtual and the actual and all the mixed realities in‐between. Here he describes his working methods and creative preoccupations that ferment into a hot, heady broth of architectural speculation. [ABSTRACT FROM AUTHOR]

Artificial light at night is increasingly recognized as a cause of habitat degradation, and as a conservation threat to wildlife species. We studied the behavioral response of Pacific kangaroo rats (Dipodomys agilis) to natural and artificial light in coastal sage scrub in southern California, United States. We used digital trail cameras to monitor visits to seed trays in shrub and open, intershrub microhabitats. Under natural-light conditions, kangaroo rats were more active on full- than new-moon nights, and concentrated foraging beneath shrubs. Surprisingly, kangaroo rats frequently interacted with other rodents in seed trays. Near to an artificial light source, kangaroo rats removed fewer seeds, had fewer foraging bouts, and spent less time in trays—especially in brightly lit open microhabitats—compared to distances farther from the light. Differences between the first and second nights of trials during both experiments suggested that kangaroo rats learned locations of resource-rich seed trays and modified their behavior accordingly. Our results are similar to recent studies showing that artificial light depresses foraging activity of rodents in the areas of highest illumination, and adds to evidence of the need to mitigate impacts of urban lighting in fragments of coastal sage scrub, especially along the urban–wildland interface. [ABSTRACT FROM AUTHOR]

Rooks (Corvus frugilegus) are an invasive bird species in South Korea that are deemed harmful due to nocturnal urban invasions and agricultural damage. Employing citizen science data, we document the daily movement patterns and habitat associations of nocturnal urban-invading rooks in Suwon, South Korea. We collected 4,522 geolocated observations from December 2021 to March 2022, categorized by the timings of sunrise and sunset and segmented into 3-h intervals. Using the MaxENT (Maximum Entropy Model) and k-fold cross-validation (k = 10) with a 25% random test sample, we analyzed daily movement patterns and habitat preferences. Our results show that rooks forage in agricultural areas shortly after sunrise and roost in urban environments after sunset. Urban roosts tend to occur in areas near buildings of medium height (6–20 stories) that are illuminated by artificial light and contain utility poles. The variables with the highest percent contribution to rooks' presence after sunset were buildings of medium height (20.7%), land use type (19.4%), elevation (29%), and utility pole (14.5%). Our findings emphasize the potential of citizen science initiatives to generate insights into the ecology of invasive bird species within large urban environments. [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of artificial light at night (ALAN) on plants is a less explored area within light pollution research. This is especially true for the physiological parameters of photosynthesis of woody plants. The physiological and morphological values of nineteen deciduous urban tree species illuminated by street lamps with a color temperature of 3000 K were examined for light‐polluted and non‐light‐polluted leaves. The morphological studies covered leaf macromorphology (leaf length, leaf width, and biomass production) and histological development (height of the dorsal epidermis and palisade parenchyma, width of photosynthesizing ground tissue and the leaf). The fluorescence yield of the photochemical system II and the net photosynthesis and transpiration of the leaves exposed to different light conditions were determined in the photosynthetic physiology studies. The species included in the research react differently to artificial light, some are able to utilize the extra lighting at night, while others are negatively affected. In this way, the species can be grouped according to their sensitivity to light pollution. The impact of street lights on vegetation can be easily detected by the combined treatment of micromorphological and photosynthetic physiology tests, macromorphological values are not suitable parameters.

This paper presents research on the development history as well as on the materials and techniques of technical installations with gas discharge lamps, colloquially known as ‘neon’ systems, in the former German Democratic Republic (GDR). Taking into account changes in materials, design, and technology between the 1950s and the 1980s, the findings also form the basis for the practical art-technological examination and evaluation of the examples still in existence. The majority of these objects have disappeared since the 1990s; the remainder are still acutely endangered today, due to progress in lighting technology and the current highly invasive repair practices. In this paper, a systematic examination case study is presented and discussed for the first time. The Poliklinik lettering under consideration is located on the façade of today's Medical Centre in the Hanseatic city of Stralsund and dates back to the second half of the 1950s. After more than 60 years of exposure to the elements, it appeared as an authentically aged, completely original example of the object group. A substance-careful concept for in situ examination was developed that did not require the fragile structure to be dismantled. The concept presented here is generally applicable to other objects with gas discharge lamps. [ABSTRACT FROM AUTHOR]

Artificial light can be used to deter unwanted non‐target catch (bycatch) from fishing gear, which is thought to be achieved by repelling bycatch, or highlighting escape routes on nets. To select for responses in bycatch species, light should (1) cause the bycatch species to avoid capture, and (2) not invoke the same reaction in target species. One way to maximise the chance of a bycatch species responding to light is to ensure the light colour used is more visible to bycatch species. Some studies have considered the visual sensitivity of certain species to address this. In particular, the wavebands of light that a species is sensitive to. However, using this measurement alone is incomplete as it does not consider other factors that affect visibility, such as the ambient light spectrum, and wavelength‐dependant light attenuation in different water types and depths. To account for these variables, and to more accurately predict how both target and bycatch species view light colours in a fishing context, we used a model of the vision of commercially relevant species in fisheries across the world. From this, we show whether a light colour is more visible to a bycatch species compared to a target species in a particular depth and water type, and how modelling can be used to make informed assessments of the selection of relevant light colours in fishing. We also discuss the limitations of using vision models alone and the need for corresponding behaviour and/or fishing trials with lights. [ABSTRACT FROM AUTHOR]

Lighting design, including both daylight and artificial light, significantly influence visual comfort and productivity of users, particularly in educational environments. Architecture students, for instance, spend most of their time in the studio, engaging in various activities. Each of these activities requires adequate illumination, especially for drawing and painting tasks. This study aims to evaluate the lighting quality in two design studios within the Department of Architecture at Umm Al-Qura University in Makkah, Saudi Arabia. In addition, it aims to realize the relationship between the illuminance design and the visual perception of the students. Data were collected through observation to obtain physical studio data and existing lighting design. DiaLux evo 12.1 software is used to simulate the lighting performance. User perception of the studio quality was obtained through a questionnaire distributed to students. The results show that the below-standard illumination level reflects on the students' responses. The study concluded that to create visually comfortable learning environments, task lighting should be utilized to ensure uniformity, and sunshades should be installed to mitigate harsh sunlight. [ABSTRACT FROM AUTHOR]

In the present study, we analyzed the effect of using a hydroponic system inside a greenhouse and different photoperiod regimes with artificial light on the nutrient uptake of bok choy. Light duration treatment consisting of both sunlight and artificial light was applied to determine the optimal photoperiod for bok choy. Advanced technology - a wireless sensor network and Internet of Things - was used to monitor and maintain nutrient concentrations. Additionally, plant growth was evaluated using image processing technology. A higher amount of P was observed to be accumulated in plants grown in plots without photoperiod. Meanwhile, excessive photoperiod was found to reduce K content in plants. The optimal photoperiod in this study was 20:4 (light:dark), which is a combination of 12 h of sunlight and 8 h of artificial light. Additionally, image processing technology helped monitor plant growth. Pixel information in images can represent plant growth with a R² value of >0.8. Further, the addition of photoperiod affects the dry weight of yields and growth rate, which is highly correlated to nutrient uptake, with R² values of 0.84 and 0.72, respectively. The combination of artificial light and sunlight along with the optimal photoperiod can optimize the growth of bok choy with appropriate NPK uptake. [ABSTRACT FROM AUTHOR]

Artificial light at night has been considered an emerging threat to global biodiversity. However, the impacts of artificial light on foraging behavior in most wild animals remain largely unclear. Here, we aimed to assess whether artificial light affects foraging behavior in Asian parti‐colored bats (Vespertilio sinensis). We manipulated the spectra of light‐emitting diode (LED) lighting in a laboratory. Using video and audio recording, we monitored foraging onset, total foraging time, food consumption, freezing behavior (temporary cessation of body movement), and echolocation vocalizations in triads of bats under each lighting condition. Analyses showed that the foraging activities of experimental bats were reduced under LED light. Green, yellow, and red light had greater negative effects on bats' foraging onset, total foraging time, and food consumption than white and blue light. LED light of different spectra induced increased freezing time and echolocation vocalizations in captive bats, except for the white light. The peak wavelength of light emission correlated positively with freezing time, estimated echolocation pulse rate (the number of echolocation pulses per minute), and foraging onset, but negatively with total foraging time and food consumption. These results demonstrate that artificial light disturbs foraging behavior in Asian parti‐colored bats. Our findings have implications for understanding the influencing mechanism of light pollution on bat foraging. [ABSTRACT FROM AUTHOR]

Light pollution is spreading around the world, causing a variety of problems, particularly for nocturnal animals such as bats. As urban areas expand, attic-dwelling bats face the problem of being exposed to more and more artificial light as they move to their dark foraging areas. Avoiding street lights could force bats to make energetically costly detours, which could eventually lead to the collapse of urban colonies. We therefore investigated the response of attic-dwelling bats to street lighting, using the brown long-eared bat (Plecotus auritus) as an example. Using radio-tracking, we followed 17 bats during their commutes through two urban areas: a small town and a village in rural Germany. After a conservative filtering process to ensure a high spatial accuracy of the tracking data, we analysed the data of nine bats in detail, using a use-versus-availability approach for the small town and a descriptive approach for the smaller dataset obtained from the village. The best-fitting model confirmed that the bats responded to artificial light at night. Close to the roost (∼10 m), bats preferred areas with low light intensities, but seemed to tolerate some light levels. We speculate that this pattern was caused by bats being forced to leave the roost into an illuminated area. At medium distances from roosts (∼400 m), most bats avoided street lights. In fact, all bats avoided being in close proximity to street lights, even when the lanterns produced only low levels of light. We conclude that brown long-eared bats avoid street lights when moving through urban areas. We recommend the establishment of dark corridors in urban areas to support high bat diversity, including all species along the continuum of light-opportunistic and light-sensitive species.

Abstract Urbanization gradients are increasingly used in ecological studies to discover responses of species communities to different intensities of human-induced habitat transformation. Here, we investigated patterns of bat communities against the background of different urbanization levels using a priori defined urbanization categories based on distance classes (5 km intervals) along a linear transect from the urban core of the city of Berlin westwards into the rural outskirts of the state of Brandenburg. Using linear-mixed effects models, we found that “distance class”, as a proxy for urbanization level, is a meaningful and suitable predictor of bat species richness and diversity. We observed an unexpectedly sudden increase in bat species richness and diversity and changes in species-specific activity levels relatively close to the urban center at the transition between urban and peri-urban areas. This change suggests a relevant influence of the peri-urban areas as a “buffer zone” for specific bat species not able to adapt to the heavily modified inner core of the metropolitan area. Although we could demonstrate that anthropogenic noise and artificial light have the potential to predict the variability of bat species activity along the urban–rural gradient, the actual influence on observed shifts in the bat community needs further research.

This article proposes an autonomous greenhouse system which has a sunlight Reflector Board (RB). In general, a greenhouse, which grows leafy vegetables, utilizes artificial light, such as LED light, as a supplementary source of light. However, artificial light cannot be used as the main source of light for photosynthesis for various kinds of plants. Our article utilizes natural sunlight, instead of artificial light, for growing plants inside a greenhouse. We develop an autonomous system to control the amount of sunlight inside the greenhouse by controlling the angle of the RB, which is located in front of the greenhouse. Since the proposed greenhouse uses natural sunlight, one can grow various kinds of plants which cannot grow under artificial light. Suppose that we accumulate the RB angle data for one year. Since solar motion repeats every year, we can control the RB according to this accumulated angle data. In this way, we can reduce unnecessary RB controls, after running the system for more than a year. As far as we know, the proposed greenhouse system based on autonomous RB controls is novel, since we control RBs for providing optimal sunlight for plants inside the greenhouse. We perform experiments to demonstrate the performance of the proposed greenhouse system. [ABSTRACT FROM AUTHOR]

Artificial lighting, including light-emitting diode (LED) illumination, is increasingly being optimized in protected agricultural systems to maximize plant yield and quality. However, it may also cause other top–down and bottom–up effects in these relatively simple ecological communities that also include insect pests and their natural enemies. While some effects of LED lighting on insects have been demonstrated to date, it is not known how they influence biological control of insect pests in practice. To examine potential top–down and bottom–up impacts of LED illumination on greenhouse biological control with parasitoids, we studied the effects of artificially lengthened days on a tri-trophic system in cages and in a greenhouse. We grew plants under a 12-h photoperiod of white-supplemented light with 6 h of additional (1) white light or (2) red and blue light, or (3) with no additional light. We exposed the plants to the pest aphid Myzus persicae (Hemiptera: Aphididae) with or without its parasitoid wasp Aphidius matricariae (Hymenoptera: Braconidae), or to no insects. The 18-h light treatments increased mean plant dry mass by 127% compared with the 12-h control without affecting the aphid's population density or the parasitoid's biological control efficacy, under relatively low light conditions. This suggests that insect communities in protected agriculture can be resilient to even drastic changes in their light environment, and that adjusting crop lighting in a manner that affects plant growth does not necessarily compromise biological control's effectiveness. [ABSTRACT FROM AUTHOR]

This research examines the natural and artificial lighting performance comparison in an architecture classroom at a university in southern Thailand and gives principles for enhancing lighting design. The sample for the study was classroom spaces. The efficacy of natural and artificial lighting was studied using static and dynamic models, and data were obtained using a 4 in 1 multi-function environmental meter at various times of the day. The current study adopted the IESNA (Illuminating Engineering Society of North America) and CIBSE (Chartered Institution of Building Services Engineers) lighting standards for the performance comparison analysis. The results showed that the natural light in the classrooms did not satisfy the standards for lighting levels. In contrast, the artificial lighting was more effective but raised some issues with uniformity and glare. The study offers recommendations for improving lighting effectiveness, maximizing natural light, reducing energy consumption, improving the uniformity of artificial illumination, addressing issues with various classroom lighting designs, and creating more comfortable and realistic learning environments. [ABSTRACT FROM AUTHOR]

This paper explores hydroponic vertical systems as a sustainable solution to modern agricultural challenges, particularly those posed by climate change. Hydroponics, a method of growing plants without soil using nutrient-rich water solutions, offers significant advantages over traditional farming. Vertical systems maximize space efficiency by growing plants in stacked layers, making them ideal for urban environments with limited space. These systems provide a controlled environment that mitigates the impacts of extreme weather, ensuring consistent crop production. The paper reviews various hydroponic techniques, including deep water culture, nutrient film technique, flood and drain, and drip irrigation. It highlights the efficiency of water use in hydroponics, crucial for areas facing water scarcity. Advanced technologies, such as sensors, automated nutrient delivery, and LED lighting, are employed to optimise growing conditions, enhance resource use efficiency, and improve crop yields. LED lights, in particular, offer energy efficiency, customizable spectra, and low heat output. Mathematical models are used to maximize plant development and resource efficiency, providing a framework for understanding plant-environment interactions. Despite high initial setup costs and the need for technical expertise, hydroponic systems present long-term economic and environmental benefits. This paper underscores hydroponic vertical systems' potential to revolutionize urban agriculture, ensuring food security and sustainability amidst climate change challenges. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) widely affects wildlife by blurring light‐dark differences, including transitions such as sunrise and sunset, thereby affecting regulation of diel rhythms. As a result, activity onsets in many wild diurnal songbirds advance under ALAN. From chronobiological studies, it is known that the direction and strength of the response to light depends on when during the night exposure takes place. However, these experiments are mostly done under continuous light conditions, when animals have free‐running rhythms. It remains unclear whether phase‐dependence also holds in entrained, wild songbirds; i.e., does the effect of ALAN on activity patterns differ between exposure in the morning compared to the evening? This information is essential to assess the effects of mitigation measures by limiting ALAN to selected times of the night. We exposed incubating great tits (Parus major) inside the nest‐box to 4 h of dim light, of which 1 h overlapped with dawn before sunrise or dusk after sunset. We found a small advancing effect of morning‐light on activity onset and of evening‐light on offset compared to dark controls but not vice versa. Breeding success and chick condition were unaffected by the light treatments. However, light‐treated females had lower weights 9–18 days after the end of the treatment compared to the controls, independent of whether ALAN occurred in the morning or the evening, indicating possible costs of ALAN. Despite the weak behavioral response, ALAN might have affected the females' circadian clock or physiology resulting in lower body condition. Research Highlights: Part‐night lighting alters natural shifts in incubation activity patterns. Thus, onset advanced by light in the early morning and offset by light in the early evening compared to dark controls, and led to lower body weights. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) is a common form of light pollution worldwide, and the intensity, timing, duration, and wavelength of light exposure can affect biological rhythms, which can lead to metabolic, reproductive, and immune dysfunctions and consequently, host–pathogen interactions. Insect vector-borne diseases are a global problem that needs to be addressed, and ALAN plays an important role in disease transmission by affecting the habits and physiological functions of vector organisms. In this work, we describe the mechanisms by which ALAN affects host physiology and biochemistry, host–parasite interactions, and vector-borne viruses and propose preventive measures for related infectious diseases to minimize the effects of artificial light on vector-borne diseases.

Purple paprika (Capsicum annuum) is a vegetable with potential economic value; however, enhancing and maintaining the purple fruit color is challenging. We investigated the effects of night blue-light supplementation on fruit growth, anthocyanin content, and gene expression in purple paprika. During two duplicated experiments conducted in spring and autumn, purple paprika plants were subjected to blue-light supplementation at night. Ten days after fruits were pollinated, night blue light with photosynthetic photon flux density (PPFD) of 80 to 100 µmol·s−1·m−2 was supplied from 1800 HR to 0500 HR (11 hours). Fruit samples were harvested 15, 20, and 40 days after pollination from control (no-light treatment) and blue light–treated fruits. The fruit size, fresh weight, anthocyanin content, and expression levels of anthocyanin biosynthesis-related genes (HY5, bHLH, WDR, MYB, PAL, CHS, F3H, DFR, ANS, and UFGT) were determined. Blue-light supplementation increased the anthocyanin-related gene expressions in the fruit peel, enhancing anthocyanin synthesis and accumulation. However, there were no significant differences between the growth of control and blue light–treated fruits. These findings highlight the potential of night blue-light supplementation to enhance anthocyanin content in purple paprika fruits without affecting overall fruit growth.

Urban noise and artificial light at night (ALAN) are global pollutants affecting animal acoustic communication. A previous study that measured noise, but not ALAN, found that vermilion flycatchers produce longer songs in noisier territories. A subsequent study in another population, that measured noise and ALAN, found that males emit longer songs in brighter, but not noisier, territories. The negative result could be due a lack of sufficient noise variation in the latter study. We evaluated the contribution of noise and ALAN on song length, provided sufficient variation in noise and ALAN. We also measured song peak frequency. During the dawn chorus, we recorded songs of 41 vermilion flycatchers in two populations (UNAM and PERM), and measured noise, ALAN, and temperature. For the population with sufficient noise and ALAN variation (UNAM), we confirmed that song length was positively associated with noise; it was also negatively associated with ALAN, especially in those males recorded late in the breeding season. At UNAM, we found an overall positive association between song pitch and ALAN; additionally, males singing at relatively low ambient temperatures (12-15 °C) produced higher pitched songs as ALAN increased. Those singing closer to new moon and at relatively low ambient noise levels (43-54 dB[A]) sang higher pitched songs in brighter territories; these two results should be taken cautiously. Our results show that light, noise, date, and temperature are associated in unexpected ways with song length and pitch, potentially affecting song information content and sexual selection.

The production of seedlings is one of the main activities for implementing agricultural crops. Many factors are involved in producing quality seedlings, including nutrition, health, genetics, and climatic factors such as temperature, humidity, and light. To evaluate the effect of light supplementation, a study was conducted using supplementary artificial light to produce lettuce and cauliflower seedlings. Sowing was carried out in styrofoam trays under a floating irrigation system. Part of the experiment containing the two species, received treatment with LED light for an additional 4 h per day, in addition to solar radiation (10 h∙day−1). The remaining seedlings received only solar radiation (without supplementation). After 37 days, the seedlings’ biometric (leaf area, root length, aerial dry mass, and root dry mass) and biochemical parameters (phenolic compounds, flavonoids, chlorophyll a/b, and total chlorophyll) were analyzed. The data showed that the complementary light enhanced the performance in all the biometric parameters evaluated in the experiment for lettuce and cauliflower. The biochemical parameters in lettuce were also higher in seedlings with light supplementation. For cauliflower, supplementary light did not differ from the natural photoperiod for biochemical parameters except for a reduction in the levels of total phenolic compounds. Considering the enhanced biometric and biochemical parameters and greater dry weight and leaf area of the seedlings grown with supplemental light, using such a tool can optimize seedling development, possibly reducing production time in the nursery and providing greater productivity.

The sweet basil Ocimum basilicum L. is the subject of numerous studies and is cultivated as a food and ornamental plant. Moreover, O. basilicum could be useful in the prevention of stroke ischemia, and its anticancer properties were recently shown. Caffeic acid derivatives, such as rosmarinic acid (RA), chicoric acid, salvianolic acids, and anthocyanins, provide the medicinal properties of basil. Therefore, investigations of the optimal growth conditions that can provide cost-effective cultivation of highly productive basil plants are relevant and important. The aim of the present work was to study the effects of a combination of soil composition and light conditions on the morphological and biochemical characteristics of O. basilicum. In totally artificial (indoor) environments, light-emitting diodes (LEDs) may provide a broad range of narrowband wavelengths with different intensities. This technology can lower operating costs. In addition to the spectral composition, light intensity (PPFD, µmol m−2s−1) is an important parameter for the optimal growth of plants. In the experiment, we used different spectra of LED lamps with intensities of 300 µmol m−2s−1: warm white, monochromatic (green and red), and a combination of blue and red. Plants were grown under various lighting conditions in soil supplemented with fertilizer, Z-ion, and Crystallon. The results showed that supplementation of soil with Crystallon had a greater effect on the growth of both above- and below-ground parts of O. basilicum plants. Interestingly, growing O. basilicum plants under R and RB light led to a 2-fold increase in the biosynthesis of both the key caffeic acid derivative RA and anthocyanin. However, given that under RB light, there is no positive effect of Crystallon on growth, the productivity of RA and anthocyanin reached a maximum when O. basilicum plants were grown under R light and Crystallon. Under these conditions, the productivity of anthocyanins and caffeic acid derivatives in O. basilicum was more than eight times greater than that in untreated O. basilicum plants.

Climate and land-use change are modifying the availability of food and water resources, which is driving more wildlife to the wildland-urban interface. For many wildlife populations, use of these areas still requires habitat connectivity both within the interface and/or to wildland habitats. However, navigating these areas can be difficult due to human development and sensory pollutants, such as artificial night light. Determining how these components of urbanization influence the behaviors and functional connectivity of species is important for managing wildlife within these mixed-use landscapes. Here we used a movescape approach based on graph theory to characterize functional uses of the landscape using metrics for behavior, connectivity, and space use intensity. We found that mule deer (Odocoileus hemionus; n = 43) functional uses of anthropogenic landscapes in the Intermountain West, USA, were dependent not only on physical barriers, terrain, and sensory factors, but also the local levels of light exposure and vegetative greenness. Remotely sensed artificial light levels had a strong influence on how mule deer used the landscape by reducing the intensity of use in the most illuminated areas given forage availability. In contrast, relatively high local light levels were associated with increased use intensity within less developed areas—highlighting the foraging tradeoffs for species using the wildland-urban interface. Corridor use was reduced in areas where road and housing density were higher, and within-corridor movement was faster when artificial light was high and vegetative greenness was low. Developing a more mechanistic understanding of how species functionally use the landscape in relation to features of urbanization can enhance conservation by delineating areas important for connectivity and foraging, while providing insights into how future development and climate change may alter movement and behavior. Spatially-explicit estimates of functional uses can directly guide management decisions to maintain species resiliency and improve land-use planning.

Artificial light can affect eyeball development and increase myopia rate. Matrix metalloproteinase 2 (MMP-2) degrades the extracellular matrix, and induces its remodeling, while tissue inhibitor of matrix MMP-2 (TIMP-2) inhibits active MMP-2. The present study aimed to look into how refractive development and the expression of MMP-2 and TIMP-2 in the guinea pigs' remodeled sclerae are affected by artificial light with varying spectral compositions. Three weeks old guinea pigs were randomly assigned to groups exposed to five different types of light: natural light, LED light with a low color temperature, three full spectrum artificial lights, i.e. E light (continuous spectrum in the range of ~390-780 nm), G light (a blue peak at 450 nm and a small valley 480 nm) and F light (continuous spectrum and wavelength of 400 nm below filtered). A-scan ultrasonography was used to measure the axial lengths of their eyes, every two weeks throughout the experiment. Following twelve weeks of exposure to light, the sclerae were observed by optical and transmission electron microscopy. Immunohistochemistry, Western blot and RT-qPCR were used to detect the MMP-2 and TIMP-2 protein and mRNA expression levels in the sclerae. After four, six, eight, ten, and twelve weeks of illumination, the guinea pigs in the LED and G light groups had axial lengths that were considerably longer than the animals in the natural light group while the guinea pigs in the E and F light groups had considerably shorter axial lengths than those in the LED group. Following twelve weeks of exposure to light, the expression of the scleral MMP-2 protein and mRNA were, from low to high, N group, E group, F group, G group, LED group; however, the expression of the scleral TIMP-2 protein and mRNA were, from high to low, N group, E group, F group, G group, LED group. The comparison between groups was statistically significant (p

Objective: Artificial light at night (ALAN) is one of the most pervasive and rapidly expanding sources of anthropogenic pollution. Aquatic ecosystems may be especially vulnerable to the effects of ALAN due to their disproportionate exposure to anthropogenic pressures. However, research on mechanisms of response to ALAN by aquatic species remains sparse. Our research investigated the extent to which ALAN influences the nocturnal feeding efficiency of Bluegill Lepomis macrochirus. Methods: Using an array of outdoor mesocosm tanks, we assigned juvenile Bluegill to five nighttime lighting treatments (control dark, 1 lx, 4 lx, 12 lx, and intermittent 12 lx). We conducted weekly nighttime feeding trials for 6 weeks to assess four prey capture variables, including capture efficiency (the effectiveness of prey strikes), capture rate (the number of prey items captured), strike rate (the frequency of prey strikes), and latency (time elapsed before the first prey strike). Result: The steady lighting treatments, which were selected based on nighttime urban light intensities we previously measured in the field, had no apparent effect on any of the prey capture variables. However, flashing high‐intensity lights (intended to mimic the effect of passing car headlights on a busy highway) had a significant negative effect on capture rate and strike rate, thereby inhibiting the ability of fish to strike at and capture prey. Conclusion: Our results demonstrate the potential for light pollution (especially flashing or intermittent lights) to interfere with the foraging behavior of this ecologically and economically important sportfish. Impact statementLight pollution, especially flashing lights, may interfere with the foraging behavior of an ecologically and economically important sport fish. [ABSTRACT FROM AUTHOR]

The production of seedlings is one of the main activities for implementing agricultural crops. Many factors are involved in producing quality seedlings, including nutrition, health, genetics, and climatic factors such as temperature, humidity, and light. To evaluate the effect of light supplementation, a study was conducted using supplementary artificial light to produce lettuce and cauliflower seedlings. Sowing was carried out in styrofoam trays under a floating irrigation system. Part of the experiment containing the two species, received treatment with LED light for an additional 4 h per day, in addition to solar radiation (10 h∙day−1). The remaining seedlings received only solar radiation (without supplementation). After 37 days, the seedlings' biometric (leaf area, root length, aerial dry mass, and root dry mass) and biochemical parameters (phenolic compounds, flavonoids, chlorophyll a/b, and total chlorophyll) were analyzed. The data showed that the complementary light enhanced the performance in all the biometric parameters evaluated in the experiment for lettuce and cauliflower. The biochemical parameters in lettuce were also higher in seedlings with light supplementation. For cauliflower, supplementary light did not differ from the natural photoperiod for biochemical parameters except for a reduction in the levels of total phenolic compounds. Considering the enhanced biometric and biochemical parameters and greater dry weight and leaf area of the seedlings grown with supplemental light, using such a tool can optimize seedling development, possibly reducing production time in the nursery and providing greater productivity. [ABSTRACT FROM AUTHOR]

The effects of anthropogenic sources of light on the circadian biology of marine animals are largely unexplored at the molecular and cellular level. Given that light is a major driver of circadian rhythms at the behavioral, physiological, cellular, and even molecular levels, it is important to consider the effects that anthropogenic light, especially at night, has on aquatic species. With the expanding data generated from circadian clock research, it is surprising that these techniques have not been applied more frequently to better understand how artificial light affects animal circadian rhythms. Circadian research has been limited to behavioral and physiological observations in wild marine animals rather than a cellular and molecular understanding due to the logistical constraints. While there are some benefits to using artificial light at night (ALAN), there have also been many studies reporting physiological and behavioral consequences in response to exposure to ALAN. Here, the benefits and consequences of using ALAN in the marine environment are reviewed. Furthermore, perspectives on research limitations and future research directions are discussed. Taken together, this is an important area in which more information is required to translate our understanding of circadian biology into better practices to promote the health and welfare of marine animals. [ABSTRACT FROM AUTHOR]

The objectives are the analysis of the benefits and risks of LED lighting systems in the economic, social and environmental fields; as well as the evaluation of the political, economic and social conditions for the use of LED lighting systems in Cuba. The relationship between the advantages of this technology and the benefits offered by its application in different sectors of society and economy is deepened. Also, its impact on the lighting industry and off-grid communities in developing countries is discussed. In addition, the main risks involved in their use are exposed, identifying the related open research fields in this direction, and it demonstrates the importance of considering the risks of LED lighting in projects. Finally, the existing conditions in Cuba for the development of LED lighting and its contribution to sustainability and energy independence are presented. [ABSTRACT FROM AUTHOR]

Weaning stress is the most common issue in swine farms, which increases mortality and morbidity. The use of artificial light is an option for modifying the immune system and metabolic pathways. This study aimed to evaluate the influence of ultraweak light (Photonia) on growth performance, immune system and metabolism of weanling pigs, and the carry‐over effect on the growth performance in postweanling growing stages. A total of 30 weaned pigs with an average initial body weight of 7.06 ± 0.11 kg (age: 21 days) were allotted two treatments (Control and Photonia) with 15 replicates. The pelleted form diets were prepared for pigs in three phases including phase 1 (Days 0–14), phase 2 (Days 15–28) and phase 3 (Days 29–48). The gain‐to‐feed ratio (G:F) of pigs was significantly greater in the Photonia treatment. On Day 28, a higher concentration of immunoglobin A (IgA) (p < 0.01) and IgG (p < 0.01) was observed in the Photonia pigs. On Day 48, the Photonia treatment showed a greater serum IgA (p < 0.01) and IgG (p < 0.05). The concentration of interleukin (IL)‐6 was decreased (p < 0.05) in the Photonia treatment. At Day 48, the concentrations of tumour necrotic factor‐α, IL‐1β and IL‐6 in serum were decreased (p < 0.05) in pigs in the Photonia treatment. Metabolic pathways analysis showed that the Photonia treatment increased the d‐glutamine, d‐glutamate, alanine, aspartate, glutamate and phenylalanine compared with the control treatment. In conclusion, the use of Photonia for weanling pigs is recommended due to improved G:F, immune status and activation of amino acids metabolic pathways including d‐glutamine, d‐glutamate, alanine, aspartate, glutamate and phenylalanine. [ABSTRACT FROM AUTHOR]

We investigated the immune-stimulating and anti-diabetic effects of Allium hookeri leaves grown in a plant factory with artificial lights. The immunomodulatory effects of A. hookeri leaves' ethanol extracts were evaluated with immune-related hematological factors in blood, the proliferation of splenocytes, NK cell activity, IgG and cytokine levels, and their mechanisms in immunosuppressed obese mice. Anti-diabetic effects were determined by the inhibitory activity against α-amylase and α-glucosidase in vitro and fasting blood glucose levels and biochemical factors in the serum of immunosuppressed obese mice. A. hookeri leaf extracts increased WBC and LYM counts, the proliferation of splenocytes, and serum IgG and IL-1β concentrations compared to those of the NC group, which was used as a negative control. A. hookeri leaf extracts also improved serum HDL levels while they decreased the activities of digestive enzymes, fasting blood glucose, and biochemical factors (ALT, AST, T-Chol, TG, LDL, and GLU). The expressions of IL-1β, JNK, c-Jun, p65, and iNOS in the thymus of immunosuppressed mice were activated by the treatment of A. hookeri leaf extracts. The results suggest that A. hookeri leaves grown in a plant factory with artificial lights also have immune-stimulatory and anti-diabetic effects and can be used as novel functional supplements to control related diseases and to improve public health. [ABSTRACT FROM AUTHOR]

The effects of anthropogenic sources of light on the circadian biology of marine animals are largely unexplored at the molecular and cellular level. Given that light is a major driver of circadian rhythms at the behavioral, physiological, cellular, and even molecular levels, it is important to consider the effects that anthropogenic light, especially at night, has on aquatic species. With the expanding data generated from circadian clock research, it is surprising that these techniques have not been applied more frequently to better understand how artificial light affects animal circadian rhythms. Circadian research has been limited to behavioral and physiological observations in wild marine animals rather than a cellular and molecular understanding due to the logistical constraints. While there are some benefits to using artificial light at night (ALAN), there have also been many studies reporting physiological and behavioral consequences in response to exposure to ALAN. Here, the benefits and consequences of using ALAN in the marine environment are reviewed. Furthermore, perspectives on research limitations and future research directions are discussed. Taken together, this is an important area in which more information is required to translate our understanding of circadian biology into better practices to promote the health and welfare of marine animals.

Tehran is the most affected town by light pollution in Iran. In this study, the role of the regional topography in the distribution of light pollution in Tehran was evaluated using digital images recording and analyzing the obtained images from Tehran sky-glow by East and South in standard image-processing Software. The scale of Tehran's glowing =dome as measured by 17 mag/arc sec2 or 0.017 cd/m2 by South, and 18.7 (mag/arc sec2) or 0.0035 cd/m2 by East. Considering the approximately equal distance of the two viewpoints from the center of Tehran city, the calculated scale by South is 1.36 times larger than the amount from the East point.

Lighting technologies develop rapidly and the energy efficiency of LEDs quadrupled between prices have decreased more than 60% in the last decade. The cyanobacterium Arthrospira platensis, commercially known as food supplement Spirulina, has great potential for urban indoor farming due to its high growth rate and low resources needed. This study investigates the combined effects of photoperiod (16–24 h light), light intensity (100–400 μmol photons m−2 s−1), and temperature (27–35℃) on production and energy efficiency in the cultivation of A. platensis in 0.5 L bubble column photobioreactor. This study aimed to develop a cost-efficient LED light regime for attaining maximal production of A. platensis. All experiments under cold white (6500 K) light show higher light energy efficiency than those under warm white (3000 K) light (p < 0.05). The light saturation point was at 261 μmol photons m−2 s−1 for warm white light and was not reached for cold white light. The maximum specific growth rate (µmax) was 2.2 day−1, 30% higher than reported in the literature. This growth rate was obtained at 24:00 light:dark photoperiod 33–35℃ and cold white light; light efficiency was 3 kW g−1 DW. Cultivation under warm white light resulted in 22% lower µmax, and light efficiency was 9 kW g−1 DW. The most economical light intensity was 193 μmol photons m−2 s−1 of cold white light. [ABSTRACT FROM AUTHOR]