Potential Use of Colored LED Lights to Increase the Production of Bioactive Metabolites Hedyotis corymbosa (L.) Lam

Hedyotis corymbosa (L.) Lam is a wild herb that is used in traditional Indian, Chinese, and African medicine. Light-emitting diode (LED) technology is paving the way to enhance crop production and inducing targeted photomorphogenic, biochemical, or physiological responses in plants. This study examines the efficiency of H. corymbosa (L.) Lam production under blue 450 nm and red 660 nm LED lights for overall plant growth, photosynthetic characteristics, and the contents of metabolite compounds. Our research showed that blue LED lights provided a positive effect on enhancing plant growth and overall biomass. In addition, blue LED lights are more effective in controlling the production of sucrose, starch, total phenolic compounds, and total flavonoid compared to red LED lights. However, blue and red LED lights played essential but different roles in photosynthetic characteristics. Our results showed the potential of colored LED light applications in improving farming methods and increasing metabolite production in herbs. LED lights are safer alternatives than genetically modified organisms or genome editing.

The effects of LED light spectrum manipulation on growth and color performance of giant gourami Osphronemus gouramy Lacepede Padang strain

This study aimed to evaluate the effect of light spectrum on growth and color performance of giant giant gourami Padang strain. The experiment used a completely randomized design (RAL) with four light emitting diode (LED) treatments in different emission spectra (white, red, green, and blue) at 550 Lux intensity, compared to the control treatment (light room with white tubular lamp at 50 Lux intensity). The irradiation was carried out for 12 hours of photoperiod. The fish used had the total length of 82.90±4.2 mm and body weight of 9.87 ± 0.99 g. The highest growth performance was found in blue LED treatment with the specific growth rate of 2.73 ± 0.2% and feed efficiency of 86.26 ± 2.71%. The best color performance was found in red LED treatment with the RGB ratio of 44.57 ± 0.62% in dorsal fin, 38.41 ± 1.36% in pectoral fins, and 45.33 ± 2.25% in anal fin with the chromatophore cell concentration at 1.973±58 cells/mm2. Keywords : Osphronemus gouramy, blue LED, spectrum, chromatophore, light ABSTRAK Penelitian ini bertujuan untuk mengevaluasi pengaruh spektrum cahaya terhadap kinerja pertumbuhan dan warna ikan gurami strain Padang. Rancangan penelitian yang digunakan adalah rancangan acak lengkap (RAL) dengan 4 perlakuan cahaya lampu light emitting diodes (LED) yang memiliki spektrum panjang gelombang berbeda (putih, merah, hijau dan biru) intensitas 550 Lux dan kontrol (cahaya ruang berasal dari lampu tubular putih intensitas 50 Lux). Penyinaran dilakukan selama 12 jam mengikuti fotoperiod. Ikan uji yang digunakan memiliki panjang total 82,90 ± 4,2 mm, dengan bobot 9,87 ± 0,99 g. Kinerja pertumbuhan terbaik terdapat pada perlakuan LED biru dengan laju pertumbuhan spesifik sebesar 2,73 ± 0,2% dan efisiensi pakan sebesar 86,26 ± 2,71%. Performa warna terbaik terdapat pada perlakuan LED merah dengan rasio warna merah pada RGB bagian dorsal sebesar 44,57 ± 0,62%, sirip pektoral sebesar 38,41 ± 1,36%, dan sirip anal sebesar 45,33 ± 2,25% dengan jumlah sel kromatofor sebanyak 1973 sel/mm2. Kata kunci : Osphronemus gouramy, LED biru, spektrum, kromatofor, cahaya

Morphogenetic and physiological effects of LED spectra on the apical buds of Ficus carica var. Black Jack

The use of artificial light sources such as light-emitting diodes (LEDs) has become a prerequisite in tissue culture studies to obtain morphogenetic enhancements on in vitro plants. This technology is essential for developmental enhancements in the growing plant cultures due to its light quality and intensity greatly influencing the in vitro growing explants at a cellular level. The current study investigates the effects of different light-emitting diode (LED) spectra on the growth of apical buds of Ficus carica var. Black Jack. Ficus carica, commonly known as figs is rich in vitamins, minerals, and phytochemicals capable of treating microbial infections and gastric, inflammatory, and cardiac disorders. Apical buds of Ficus carica var. Black Jack, presented morphogenetic changes when grown under six different LED spectra. The highest multiple shoots (1.80 per growing explant) and healthy growing cultures were observed under the blue + red LED spectrum. Wound-induced callus formation was observed on apical buds grown under green LED spectrum and discolouration of the growing shoots were observed on the cultures grown under far-red LED spectrum. Multiple shoots obtained from the blue + red LED treatment were rooted using 8 µM indole-3-acetic acid (IAA), and the rooted plantlets were successfully acclimatised. Compared with the other monochromatic LEDs, blue + red proved to be significantly better for producing excellent plant morphogeny. It is apparent that blue and red LED is the most suitable spectra for the healthy development of plants. The findings have confirmed that the combination of blue + red LED can potentially be used for enhancing growth yields of medicinally and commercially important plants.

A fluorescent dissolved oxygen sensor with autocalibration based on ruthenium (II) tris-bathophenanthroline complex

The study describes a submersible fluorescent dissolved oxygen (DO) sensor suitable for aquaculture facilities. The sensor is based on the quenching of fluorescence from ruthenium (II) tris-bathophenanthroline complex, [Ru(dpp)3]2+. One of its precursors, bathophenanthroline (BPhen), was obtained by a green approach with less aggressive reagents than in a classical synthesis. It was embedded in a polymer membrane and attached to a glass window to fabricate a sensing element. The composition and functioning of the sensor are described. It uses an additional red LED for automatic calibration and correction of measurements due to photodegradation of Ru(dpp) over time. The intensity of the red light reflected from the active Ru(II) centres indicates their concentration and allows for automatic correction of the calibration factor. The sensor has demonstrated good linearity in calibration tests; its readings were independent of the presence of common inorganic ions in water, which might interfere with the results. This novel low-cost sensor with autocalibration is expected to be a long-term solution for aquaculture.

Comparing Light—Emitting—Diodes Light Traps for Catching Anopheles Mosquitoes in a Forest Setting, Western Thailand

Light traps are a common method for attracting and collecting arthropods, including disease vectors such as mosquitoes. Various types of traps have been used to monitor mosquitoes in a forest in Western Thailand. In this study, four Light Emitting Diodes (LED) light sources (UV, blue, green, and red) and two fluorescent lights (white and UV) were used to trap nocturnal adult mosquitoes. These traps were used with light alone and not any additional attractant. The experiment was conducted from 18:00 to 06:00 h. on six consecutive nights, every two months, across dry, wet, and cold seasons. All specimens were first identified by morphological features and subsequently confirmed by using PCR. We collected a total of 873 specimens of 31 species in four genera, Anopheles, Aedes, Culex, and Armigeres. Anopheles harrisoni was the predominant species, followed by Aedes albopictus, Culex brevipalpis, Culex nitropunctatus, and Armigeres (Leicesteria) longipalpis. UV fluorescent light was the most effective light source for capturing forest mosquitoes, followed by UV LED, blue LED, green LED, white fluorescent, and red LED. The optimal times for collection were from 21:00 to 03:00 h in the dry season. Our results demonstrate that appropriate sampling times and light sources should be selected for optimal efficiency in vector surveillance programs.

Assessing horseshoe crab avoidance response of flicker and continuous red-light LED: Gillnets bycatch mitigation

The horseshoe crab has the important roles as macrobenthos, but it is unfriendly for gillnets fisheries because it can damage the fishing net. The horseshoe crab is an ancient, rare, and protected animal so that the fishermen unable to utilize it, so the effort like mitigations need to be conducted like using red light LED. To avoid the learning behavior of horseshoe crab, so that the technology used is red light LED continuous then the red light led with flicker is used as a comparison. This study aims to determine the right type of red-light LED for horseshoe crab bycatch mitigation by the response pattern. The method used was a laboratory experiment. There are 20 adult horseshoe crabs used. The analysis used was descriptively comparative. The results showed that the red-light LED with flicker was most avoided by horseshoe crabs, which is 75%, while the fastest response of horseshoe crab in avoiding light was found in the light with a flicker effect of 22.97 seconds. Based on the horseshoe crab’s response, it can be concluded that the red LED light flicker is better than the red LED continuous as an alternative technology for the mitigation of horseshoe crab bycatch.

The use of mixed light-emitting diodes and natural light in combination with daylength affects turkey hen performance, eye development, and feather coverage

Lighting is a complex management tool in turkey production, controlled by three parameters; daylength, intensity, and chromaticity. As light-emitting diodes (LED) increase in popularity as alternatives to traditional light sources, research regarding LED impacts on commercial-type turkey production is lacking. Therefore, turkey hens of the same strain were reared under experimental brooding and grow-out conditions with six lighting treatments. An environmentally and light controlled facility (ECF) consisted of 5,000 Kelvin (K) LED or 5,000K + far-red LED (639nm) (RED) with either 12h short or 18h long daylength to test LED spectra. In the remaining treatments, hens were exposed to sunlight in a curtain-sided facility (CSF) as two treatments 1) natural decreasing daylength from September to November (NAT) or 2) natural daylight + 5,000 K LED lighting with an 18h long blocked daylength (BLK). The intensity was 9 footcandles in the ECF and naturally fluctuating in the CSF. Hen's performance was evaluated at 5, 9, and 14 weeks for eye development and feather coverage. Hens brooded and grown-out under NAT light had significantly increased body weight gain compared to BLK hens for the same period. Hens reared with RED LED spectrum had significantly increased eye anterior-posterior distance than birds raised in the NAT treatment. A significant reduction in red heat signature on the breast tissue in the NAT treatment compared to all other 18h treatments indicated improved feather coverage. However, these same results were not observed during serum thyroid hormone analysis. While turkey hens reared under different lighting programs had similar ending performance, lighting parameters significantly affected bird performance during the growing period, bird's eye development, and body feather coverage. Therefore, potential effects on growth patterns and physiology should be considered when choosing a LED lighting program for turkeys

Critical Photoperiod and Optimal Quality of Night Interruption Light for Runner Induction in June-Bearing Strawberries

The optimal photoperiod and light quality for runner induction in strawberries ‘Sulhyang’ and ‘Maehyang’ were investigated. Two experiments were carried out in a semi-closed walk-in growth chamber with 25/15 °C day/night temperatures and a light intensity of 250 μmol·m–2·s–1photosynthetic photon flux density (PPFD) provided from white light-emitting diodes (LEDs). In the first experiment, plants were treated with a photoperiod of either 12, 14, 16, 18, 20, or 22 h In the second experiment, a total of 4 h of night interruption (NI) light at an intensity of 70 μmol·m–2·s–1PPFD provided from either red, blue, green, white, or far-red LED in addition to 11 h short day (SD). The results showed that both ‘Sulhyang’ and ‘Maehyang’ produced runners when a photoperiod was longer than 16 h, and the number of runners induced positively correlated with the length of photoperiod. However, the plant growth, contents of chlorophyll, sugar and starch, and Fv/Fo decreased in a 22 h photoperiod. All qualities of the NI light, especially red light, significantly increased the number of runners and daughter plants induced per plant as compared with those in the SD treatment in both cultivars. In a conclusion, a photoperiod between 16 and 20 h and NI light, especially red NI light, can be used for quality runner induction in both ‘Sulhyang’ and ‘Maehyang’.

PSI Open Fluor CAM script for measuring qE component of NPQ in Chlorella vulgaris v1

This is a simple protocol that consists of 1) 10 minutes preillumination with far red light 2) 5 minutes of illumination with actinic light 3) 5 minutes of dark adaptation with far red light qE is calculated as the differe between NPQ_Lss and NPQ_D5 qE=NPQ_Lss-NPQ_D5 qI=NPQ_D5 Protocol to be used with FluorCAM 7.0 on a PSI Open FC 800-O/1010-S. Act 2 - are the white light LED arrays ADD2 - is the far red LED array Camera is placed at ~20 cm above the measured sample. Light intensity uniformity across the 96 well plate was measured according to manufacturer instructions. !Important - protocol only works under weak far red light. Intense far red will interfere with the fluorescence measurement.