Development and Testing of a Modular Sunlight Transport System Employing Free-Form Mirrors

The energy consumption of artificial lighting and its impacts on health have stimulated research into natural lighting systems. However, natural lighting system designs are mainly custom, making them costly and difficult to replicate. This study took an office space as a testing field in order to develop a highly adaptable and adjustable modular natural light illumination system. We divided the system into multiple module designs, demonstrated the use of simple development and fabrication processes and integrated a freeform reflector into the system. In creating a freeform mirror, the optical simulation results of the tested field were regressed (through polynomial regression) to achieve a uniformly illuminated plane, and a high-efficiency light-emitting system was produced. Finally, an active heliostat was used to collect sunlight, combined with actual manufacturing verification and measurement results, in order to create an excellent indoor lighting system. As a result, we presented a low-cost and easy-to-design natural light illumination system for the assisted lighting of office areas.

Toward Multiplexed Optogenetic Circuits

Owing to its ubiquity and easy availability in nature, light has been widely employed to control complex cellular behaviors. Light-sensitive proteins are the foundation to such diverse and multilevel adaptive regulations in a large range of organisms. Due to their remarkable properties and potential applications in engineered systems, exploration and engineering of natural light-sensitive proteins have significantly contributed to expand optogenetic toolboxes with tailor-made performances in synthetic genetic circuits. Progressively, more complex systems have been designed in which multiple photoreceptors, each sensing its dedicated wavelength, are combined to simultaneously coordinate cellular responses in a single cell. In this review, we highlight recent works and challenges on multiplexed optogenetic circuits in natural and engineered systems for a dynamic regulation breakthrough in biotechnological applications.

Welcome to the Dark Side: Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal

Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics.

Shade stress on maize seedlings biomass production and photosynthetic traits

ABSTRACT: The responses of two maize (Zea mays L.) cultivars, ‘LY336’ (shade tolerant) and ‘LC803’ (shade sensitive), to shade stress in a pot experiment conducted in the 2015 and 2016 growing seasons were investigated. The impact of 50% shade stress treatment on shoot biomass, photosynthetic parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content was evaluated. The shoot biomass of the two maize hybrids was decreased significantly by shade stress treatment, for shade stress 7 d, the LC803 and LY336 were reduced by 56.7% and 44.4% compared with natural light. Chlorophyll fluorescence parameters of LY336 were not significantly affected by shade stress, whereas those of LC803 were significantly affected, the Fo increased under shade stress; however Fm, FV/FM and ΦPSII were decreased under shade stress. Among photosynthetic parameters measured, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate were significantly decreased compared with natural light, LY336 and LC803 reduction by 28.0%, 22.2%, 57.7% and 35.5%, 18.9%, 62.4%; however, intercellular CO2 concentration (Ci) was significantly increased, for the two cultivars. Under shade stress for different durations (1, 3, 5, 7 d), Pn, Gs, Ci, and MDA content differed significantly between the two cultivars. Results indicated that different maize genotypes showed different responses to shading. Shade-tolerant genotypes are only weakly affected by shade stress.

Color-tuning Pt(ii) complexes for natural-light electrophosphorescence

Efficient and durable OLEDs of cyan, greenish yellow, yellow and white colors were fabricated in simple structures with Pt–Cpy bonded complexes, giving state-of-the-art tuning the color of electroluminescence.

CIRCADE RHYTHMS OF PINCHUK'S GOBY PONTICOLA CEPHALARGOIDES (PINCHUK, 1976) IN LABORATORY CONDITIONS

Introduction. Circadian rhythms help the body to anticipate changes in environmental conditions and adapt to the daily fluctuations of external factors. The presence of such mechanisms, which provide early preparation of the organism, gives an advantage in the struggle for survival. The dynamics of light is one of the main factors, which determines the level of growth, development, nutrition, metabolism, affects hormonal activity. Aim. The aim of the study was to study the circadian rhythms of motor activity of Pinchuk's goby Ponticola cephalargoides (Pinchuk, 1976) in the laboratory. Methods. To study the activity of the fish individuals of the Pinchuk's goby caught in the Gulf of Odesa on a fishing rod were selected. The experiments were performed in an aquarium with two lighting options – under natural light and in the complete round-the-clock absence of lighting. Measurements of the fish activity were recorded at 1 hour intervals for 5 days. Results. The study revealed that the activity in constant darkness is generally lower than in the natural light. In both cases, the maximum value of the motor activity occurs in the first half of the day. Under the natural light, the activity of the Pinchuk's goby reaches the maximum value from 06:00 to 07:00, in constant darkness the activity reaches the maximum from 07:00 to 08:00. The difference in the activity of the fish between the two lighting modes is most noticeable from 16:00 to 22:00. Conclusion. It is established that the activity of Pinchuk's goby is cyclical both under the natural light conditions and in the absence of light. From 00:00 to 16:00 Pinchuk's goby has an endogenous circadian rhythm, from 16:00 to 22:30 the rhythm is exogenous.

The Psychological Impact of Color and Light in Interior Design on Teenagers

Interior design is a wide profession that can drastically influence how people feel and use a room. Marco Costa’s research on the effect of color in a room and Markus Canazei’s study on the effect of natural light in a room both focused on how adults were influenced by light and color in rooms. This ultimately led to both studies in this research process focused on teenagers because there isn’t a great amount of research on how light and color can affect teenagers in a room. The results showed that teenagers have a preference towards neutral and cool tones as opposed to adults who prefer warm tones. Teenagers also have a preference towards natural light similar to adults. More research can be done on understanding how light and color can affect teenagers in other environments such as school settings. Further research is necessary to obtain more information on the psychological impact of interior design on teenagers.

Seed Germination of the Herbaceous Vine Tropaeolum pentaphyllum Lam. (Tropaeolaceae): A Neglected Geophyte with High Agricultural Potential

The objective of this study was to evaluate the seed germination of Tropaeolum pentaphyllum Lam., an endangered geophyte native of southern Brazil with agriculture potential due its edible tubers. Two experiments were carried out in 2017: germination of T. pentaphyllum under natural conditions and under controlled conditions. In the experiments under natural and controlled conditions, the germination of 1,100 and 100 seeds was evaluated, respectively. In the experiment under controlled conditions, two treatments (natural light and dark) were evaluated and each treatment contained 50 seeds. In the natural conditions experiment, in 2018 (first year), of the 1,100 seeds, 5.6% germinated and 76.5% persisted in the soil; and in 2019 (second year), 5.3% of the seeds germinated and no seeds remained in the soil. In natural conditions experiment, 10.9% of seeds germinated over two years. In controlled conditions experiment, in 2018 the germination in dark was higher (48%) compared to natural light (18%); and in 2019, despite the absence of statistical differences, the dark showed a higher value of germination (12%) in relation to natural light (6%). Over two years, dark treatment showed higher germination (60%) compared to natural light (24%) and no seeds remained in the substrate. The production of tubers in plants obtained by seed germination was 98.4% and 100%, in natural and controlled conditions, respectively. The highest germination rates occurred under dark conditions indicating that the species is preferential negative photoblastic. In addition, this species forms a seed bank in the soil, in which the seeds remained for a maximum of two years. The seed germination can contribute to the genetic diversity of crops and the production of seed-tubers, decreasing the collection of tubers in situ, contributing to the conservation and agricultural use of T. pentaphyllum.