High Light Research Articles

Pengaruh Tata Letak Ruang Kelas Trerhadap Interaksi Siswa dalam Kegiatan Pembelajran

Currently, we still often find messy classrooms, high classroom temperatures, ventilation and lighting systems that are not appropriate for the classroom, tables and chairs that are not neatly arranged, and learning materials that are not arranged well, which affects concentration. and interaction. The aim of this research is to identify the effect of U-Shape and Cluster class divisions on interactions between students and teachers, as well as between students and other students in learning activities, identify the impact on student concentration, and evaluate the effectiveness of the layout. This research uses qualitative methods by means of observation and questionnaires given to class XI students of Modeling Design and Building Information at SMK Negeri 1 Ngasem Kab. Kediri. Data obtained from interviews with students and studying several articles were then processed into narratives for discussion. To assess interaction and concentration in different types of layouts. Research shows that a more flexible layout, namely U-Shape, significantly increases interaction between students and teachers, as well as between students and other students in learning activities. In addition, this research found that ergonomic classroom layouts that can be modified based on learning needs tend to be more effective in increasing student concentration. Thus, classrooms that are designed flexibly and more interactively have proven effective in creating a more dynamic learning atmosphere, increasing engagement, and facilitating student focus. These findings provide recommendations for educators and schools to consider more effective classroom designs to support the teaching and learning process.

Panopticon: A novel deep learning model to detect single transit events with no prior data filtering in PLATO light curves

To prepare for the analyses of the future PLATO light curves, we develop a deep learning model to detect transits in high precision photometric light curves. Since PLATO's main objective is the detection of temperate Earth-sized planets around solar-type stars, the code is designed to detect individual transit events. The filtering step, required by conventional detection methods, can affect the transit, which could be an issue for long and shallow transits. To protect the transit shape and depth, the code is also designed to work on unfiltered light curves. The model is based on the Unet family architecture, but it is able to more efficiently extract and combine features of various length scale, leading to a more robust detection scheme. We trained the model on a set of simulated PLATO light curves in which we injected, at the pixel level, planetary, eclipsing binary, or background eclipsing binary signals. We also included a variety of noises in our data, such as granulation, stellar spots, and cosmic rays. We then assessed the capacity of to detect transits in a separate dataset. The approach is able to recover 90% of our test population, including more than 25% in the Earth-analog regime, directly in unfiltered light curves. We report that the model also recovers transits irrespective of the orbital period, and it is therefore able to reliably retrieve transits on a single event basis. These figures were obtained when accepting a false alarm rate of 1%. When keeping the false alarm rate low ($<0.01$%) is still able to recover more than 85% of the transit signals. Any transit deeper than ∼180ppm is essentially guaranteed to be recovered. This method is able to recover transits on a single event basis, and it does so with a low false alarm rate. Due to the nature of machine learning, the inference time is minimal, around 0.2,s per light curve of 126,720 points. Thanks to light curves being one dimensional, the model training is also fast, on the order of a few hours per model. This speed in training and inference, coupled with the recovery effectiveness and precision of the model, make this approach an ideal tool to complement or be used ahead of classical approaches.

Unlocking the potential of cacao yield with full sun cultivation

Cacao and chocolate production is a global industry worth around $133 billion. Full sun cultivation is a modern approach aimed at increasing yields. We evaluated six cacao clones (PS 1319, CCN 10, CCN 51, PH 16, SJ 02, and CP 49) grown under full sun conditions to assess their leaf physiology, leaf structure, yield, and yield components. Leaf physiology was measured through seven gas exchange parameters, while leaf structure was analyzed using eight measurements. For fruit and seed, we evaluated seven yield components. The clones showed differences in gas exchange. Clones PH 16 and PS 1319 had higher net photosynthetic rates per unit of leaf area (A), transpiration rates, and lower leaf internal CO2 concentrations. These A high values suggest the clones are well-acclimatized to full sun cultivation. Water availability, nutrient supply, and appropriate plant architecture also contributed to this acclimatization. Under high light intensity, the potential quantum yield of photosystem II indicated no photoinhibition, and adaptations in the photosynthetic apparatus were observed, such as lower pigment concentration in clone PH 16. Clones differed in specific leaf area (SLA) and stomatal density (SD). CCN 51 had a higher SLA, while SJ 02 had a higher SD. A significant negative correlation (-0.89) was found between dry bean yield and leaf-to-air water vapor pressure deficit (VpdL), suggesting that VpdL is a crucial parameter for selecting high-performance clones for fertigated full sun cultivation. Yields ranged from 1,220 kg/ha (CCN 10) to 2,900 kg/ha (CCN 51). Full sun cacao farms have high yield potential due to a combination of cloning, management practices, and adequate water and nutrient availability.

Enhanced Photoelectrochemical Performance by Constructing CdS/CdSe Heterojunction Structure

The growing need for sustainable energy development has become a critical issue due to worsening environmental pollution and climate change. Among the various technologies, the photoelectrochemical technology has been recognized as one of the essential approaches for advancing sustainable energy production. Out of the semiconductor materials used in PEC systems, cadmium sulfide (CdS) and cadmium selenide (CdSe) have been widely studied as promising candidates due to their advantageous properties. CdS, with a bandgap of 2.4 eV and high photoactivity, and CdSe, with a narrower bandgap of 1.9 eV and excellent light absorption characteristics, offer complementary advantages. In this study, we synthesized the CdS and CdSe materials via hydrothermal and chemical bath deposition methods, respectively, to fabricate a CdS/CdSe heterojunction photoanode system. The heterojunction CdS/CdSe photoanode formed a type-II structure, which facilitated efficient charge separation and transfer. Moreover, the CdS/CdSe photoanode exhibited high light absorption properties with very low charge transfer resistance, attributed to the role of CdS particles beneath CdSe as an electron transfer layer and the porous structure of the composite material. As a result, the CdS/CdSe photoanode achieved high photocurrent density of 4.51 mA·cm<sup>-2</sup> comparing to their individual cases, representing a 78% improvement in PEC performance compared to the only CdSe photoanode case.

Links Between Two Duckweed Species (Lemna minor L. and Spirodela polyrhiza (L.) Schleid.), Light Intensity, and Organic Matter Removal from the Water—An Experimental Study

Duckweeds—a group of floating leaf macrophytes from the family of Lemnaceae—have become a major area of interest in the fields of basic and applied aquatic sciences in recent decades, including their use in water purification. Aiming to fulfill one of the gaps in the role of light intensity in duckweed efficiency in organic matter removal, we carried out a laboratory experiment with the use of two duckweed species: Lemna minor and Spirodela polyrhiza. Our main finding was that the intensity of light has a positive effect on the process of water purification from organic compounds by Lemna minor. However, this was not applicable to Spirodela polyrhiza due to the fact that the growth of the species was inhibited by high light intensities.

A cyanobacteria-derived intermolecular salt bridge stabilizes photosynthetic NDH-1 and prevents oxidative stress

Throughout evolution, addition of numerous cyanobacteria-derived subunits to the photosynthetic NDH-1 complex stabilizes the complex and facilitates cyclic electron transfer around photosystem I (PSI CET), a critical antioxidant mechanism for efficient photosynthesis, but its stabilization mechanism remains elusive. Here, a cyanobacteria-derived intermolecular salt bridge is found to form between the two conserved subunits, NdhF1 and NdhD1. Its disruption destabilizes photosynthetic NDH-1 and impairs PSI CET, resulting in the production of more reactive oxygen species under high light conditions. The salt bridge and transmembrane helix 16, both situated at the C-terminus of NdhF1, collaboratively secure the linkage between NdhD1 and NdhB, akin to a cramping mechanism. The linkage is also stabilized by cyanobacteria-derived NdhP and NdhQ subunits, but their stabilization mechanisms are distinctly different. Collectively, to the best of our knowledge, this is the first study to unveil the stabilization mechanism of photosynthetic NDH-1 by incorporating photosynthetic components into its conserved subunits during evolution.

A plant endophytic bacterium Burkholderia seminalis strain 869T2 increases plant growth under salt stress by affecting several phytohormone response pathways

BackgroundDue to global warming and gradual climate change, plants are subjected to a wide range of environmental stresses, adversely affecting plant growth and production worldwide. Plants have developed various mechanisms to overpower these abiotic stresses, including salt stress, drought, and high light intensity. Apart from their own defense strategies, plants can get help from the beneficial endophytic bacteria inside host plants and assist them in enduring severe growth conditions. A previously isolated plant endophytic bacteria, Burkholderia seminalis 869T2, from vetiver grass can produce auxin, synthesize siderophore, and solubilize phosphate. The B. seminalis 869T2 can colonize inside host plants and increase the growth of bananas, Arabidopsis, and several leafy vegetables.ResultsWe further demonstrated that different growth parameters of Arabidopsis and pak choi plants were significantly increased after inoculating the B. seminalis 869T2 under normal, salt, and drought stress conditions compared to the mock-inoculated plants. Both transcriptome analysis and quantitative real-time PCR results showed that expression levels of genes related to phytohormone signal transduction pathways, including auxin, gibberellin, cytokinin, and abscisic acid were altered in Arabidopsis plants after inoculated with the strain 869T2 under salt stress, in comparison to the mock-inoculated control with salt treatments. Furthermore, the accumulation levels of hydrogen peroxide (H2O2), electrolyte leakage (EL), and malondialdehyde (MDA) were lower in the 869T2-inoculated Arabidopsis and pak choi plants than in control plants under salt and drought stresses.ConclusionsThe plant endophytic bacterium strain B. seminalis 869T2 may affect various phytohormone responses and reduce oxidative stress damage to increase salt and drought stress tolerances of host plants.

Exploiting synergy of dopamine and stressful conditions in enhancing Haematococcus lacustris biomass and astaxanthin yield.

Dopamine (DA) has attracted attention because of its effects on Haematococcus lacustris biomass, astaxanthin production, and physiological responses. The alga treated with 25μM DA combined with 1g L-1 sodium chloride exhibited 7.63%, 41.25%, and 52.04% increases in biomass (1.41g L-1), astaxanthin content (32.37mg/g), and astaxanthin productivity (3.51mg L-1 d-1) respectively, compared with the salinity stress and high light. Exogenous DA treatment promoted lipid synthesis while reducing carbohydrate and protein contents. Moreover, carotenogenesis and lipogenesis-associated genes were upregulated under DA induction. Inhibition of reactive oxygen species and autophagy, along with mitogen-activated protein kinase activation, promoted astaxanthin accumulation under DA. Furthermore, DA application boosted astaxanthin biosynthesis by regulating the levels of respiratory metabolic intermediates, the γ-aminobutyric acid shunt, and important phytohormones. These findings present a potential and successful biotechnological approach for enhancing biomass and astaxanthin production in H. lacustris under stressful conditions.

Structural design of dual Z-scheme GCN/CdO/CaFe2O4 ternary heterojunction with high visible light activity: Photocatalytic performance and mechanism in the degradation of Congo red dye

Structural design of dual Z-scheme GCN/CdO/CaFe2O4 ternary heterojunction with high visible light activity: Photocatalytic performance and mechanism in the degradation of Congo red dye

Visible light-driven copper vanadate/biochar nanocomposite for heterogeneous photocatalysis degradation of tetracycline: Performance, mechanism, and application of machine learning.

Water pollution caused by antibiotics is considered a major and growing issue. To address this challenge, high-performance copper vanadate-based biochar (CuVO/BC) nanocomposite photocatalysts were prepared to develop an efficient visible light-driven photocatalytic system for the remediation of tetracycline (TC) contaminated water. The effects of photocatalyst mass, solution pH, pollutant concentration, and common anions on the TC degradation were investigated in detail. Analytical techniques indicated that the CuVO exhibited a nanobelt-like structure with a uniform distribution on the wrinkled biochar surface. The XRD spectrum confirmed that the as-prepared nanomaterial was composed of Cu3V2O7(OH)2·2H2O. Meanwhile, XPS analysis revealed that copper was present in two forms: monovalent and divalent, while vanadium remained pentavalent. The CuVO/BC exhibited excellent stability and high visible light photocatalytic activity towards TC degradation over a wide pH range. The presence of SO42-, H2PO4-, CO32-, and citric acid inhibited the degradation process due to the consuming of photogenerated h+ and •OH, while Cl- enhanced the efficiency of photocatalytic reactions due to generating chlorine oxidizing species. The CuVO/BC showed lower electron-hole recombination rate, more effective separation of photogenerated carriers, lower charge transfer resistance, and higher visible light absorption capacity comparing to pure CuVO by the addition of BC, thus improving the overall photocatalytic performance. In terms of oxidation mechanism, the EPR test and quenching experiment revealed that the contribution of the active species to the degradation of TC followed the order h+ > 1O2>•OH>•O2-. Through the application of machine learning models to analyse the influencing factors of photocatalytic processes, it was discovered that the GBDT model exhibited optimal reliability for the photocatalytic system, and the simulation results were in agreement with the experimental findings.

Uncovering the Origin of Light‐Promoted Synergetic Effect and Y Doping in Enhancing Photothermocatalytic Dry Reforming of Methane on Ni/Ni‐Y2‐Al2O3

Photothermocatalytic dry reforming of methane (DRM) can convert CH4 and CO2 into syngas, offering an effective approach to reducing greenhouse gas emissions. However, photothermocatalytic DRM reaction generally needs a high light intensity surpassing 192 kW m−2 to attain high light‐fuel conversion. Also, catalysts applied to photothermocatalytic DRM are liable to inactivation due to carbon deposition. Herein, a nanocomposite of Ni nanoparticles supported on Ni‐ and Y‐doped Al2O3 (Ni/Ni‐Y2‐Al2O3) is prepared. It achieves high H2 and CO production rates with a light‐to‐fuel efficiency (29.2%) at a lower intensity (80.1 kW m−2). Meanwhile, it sustains excellent photothermocatalytic durability and accomplishes a 37‐fold reduction in carbon deposition rate compared to Ni/Al2O3. The substantially enhanced catalytic activity and carbon resistance of Ni/Ni‐Y2‐Al2O3 are correlated with accelerating carbon species (C*) oxidation (the rate‐determining steps of DRM). This acceleration derives from the synergetic effect and carbonate species resulting from Y doping, which participate in C* oxidation via two separate reaction pathways. When in light, the synergetic effect further facilitates C* oxidation. Simultaneously, light immensely reduces activation energy, activates the NiO bonds at the interface region, and expedites the reaction between carbonate species and C* in the interface, enhancing catalytic activity and carbon resistance.

A highly transparent cellulose film for shielding ultraviolet and high-energy visible blue light.

The ultraviolet (UV) and high-energy visible blue (HEVB) light can cause damage to the eyes and skin. In this study, a cellulose composite film with UV and HEVB light shielding properties was prepared through the incorporation of a shielding agent into a carboxymethyl cellulose (CMC) solution. The shielding agent was synthesized through a Schiff base reaction between vanillin (VA) and 3-aminopropyltriethoxysilane (APS). The composite films exhibited excellent shielding performance against UV and HEVB light and maintained high visible light transmittance. Additionally, the films achieved shielding ratios of 100% for UV (200 to 400nm) and 93% for HEVB (400 to 450nm), respectively. Even under prolonged UV irradiation, the composite films maintained excellent shielding stability. The composite films exhibited higher performance in blocking UV and HEVB light than commercial shielding films. Moreover, the composite films achieved 100% antibacterial efficiency against both Staphylococcus aureus and Escherichia coli, even with minimal amounts of the shielding agent. Furthermore, the films exhibited significant improvements in thermal stability, oxidation resistance, and mechanical properties. The multifunctional UV and HEVB shielding films have broad potential applications in food packaging, anti-UV/HEVB radiation display screens, and mobile phone screens.

Comparison of the Effect of High Light Intensity on the Response of Solanum lycopersicum and Arabidopsis thaliana to Low Temperature

This study compares the effect of light intensity on the responses of two plants with different cold tolerance – tomato (Solanum lycopersicum L.) and on model plant Arabidopsis (Arabidopsis thaliana Col 0) to several days' treatment by low temperature and after recovery at control conditions. Net photosynthetic rate was evaluated by oxygen evolution from leaf discs. The photosynthetic performance was assessed by the maximal quantum efficiency of photosystem II and the degree of non-photochemical and non-regulated quenching. Malondialdehyde accumulation was used as a stress indicator and synthesis and accumulation of anthocyanins as an indicator for activation of defense mechanism. The results demonstrated that in Arabidopsis plants the high light treatment at control and low temperature increased non-regulated quenching but, in tomato plants the balance between both quenching mechanisms was maintained.

Current insights into molecular mechanisms of environmental stress tolerance in Cyanobacteria.

The photoautotrophic nature of cyanobacteria, coupled with their fast growth and relative ease of genetic manipulation, makes these microorganisms very promising factories for the sustainable production of bio-products from atmospheric carbon dioxide. However, both in nature and in cultivation, cyanobacteria go through different abiotic stresses such as high light (HL) stress, heavy metal stress, nutrient limitation, heat stress, salt stress, oxidative stress, and alcohol stress. In recent years, significant improvement has been made in identifying the stress-responsive genes and the linked pathways in cyanobacteria and developing genome editing tools for their manipulation. Metabolic pathways play an important role in stress tolerance; their modification is also a very promising approach to adapting to stress conditions. Several synthetic as well as systems biology approaches have been developed to identify and manipulate genes regulating cellular responses under different stresses. In this review, we summarize the impact of different stresses on metabolic processes, the small RNAs, genes and heat shock proteins (HSPs) involved, changes in the metabolome and their adaptive mechanisms. The developing knowledge of the adaptive behaviour of cyanobacteria may also be utilised to develop better stress-responsive strains for various applications.

Inter-specific variability in photophysiological responses of epipelic diatoms to the actin inhibitor Latrunculin B

This study investigates whether the actin inhibitor Latrunculin B (Lat B) can be used to study the interplay between cellular motility and photosynthetic activity of pennate diatoms, by inhibiting their motility while not affecting their photosynthetic performance. The effects of increasing concentrations of Lat B (2.5, 5, and 10 µM) on cellular motility (% motile cells) was measured on several species of pennate diatoms and on natural microphytobenthic assemblages. The species Entomoneis paludosa, Nitzschia longissima, Craspedostauros britannicus, and Pleurosigma strigosum were used for testing the existence of species-specific effects. The results showed that all tested concentrations of Lat B inhibited diatom motility in all studied species, with no decrease in efficacy over at least 5 hours. The effect of Lat B on photosynthetic activity (PSII electron transport rate and non-photochemical quenching) was tested at 2.5 µM. Parameters extracted from light-response curves of relative electron transport rates of PSII (rETR vs E) and from light-induced photoprotection through thermal dissipation of energy (NPQ vs E) did not show common differences between treated and untreated cells. However, some species-specific effects were observed, underscoring the need for careful consideration when using chemicals, based on the specific model under study. Furthermore, treatment with Lat B did not affect the impact of high light exposure on PSII quantum yield. Nevertheless, Lat B appeared to partially reduce the ability of the cells to recover from high light stress, suggesting a potential involvement of actin filaments in photoinhibitory processes.

Electronic, optical and photocatalytic water splitting properties of two-dimensional monolayers of Janus Cd2XY (X = S, Se; Y = Se, Te; X ≠ Y): A first-principles study

Abstract Two-dimensional Janus materials play a significant role in the advancement of optoelectronic devices and photocatalytic water splitting. In the present work, the stability, electronic structure, transfer properties, optical properties, and photocatalytic water-splitting properties of three Janus monolayers (Cd2SSe, Cd2STe, and Cd2SeTe) were investigated by using first-principles calculations. It is found that they are well-stabilized with a band gap Eg of 1.14, 1.49, and 2.32 eV (the photocatalytic water splitting threshold being 1.23 eV) respectively, all of which correspond to direct band gap semiconductors. They all demonstrate excellent electron mobility and hole mobility, along with high light absorption in the visible range. The band-edge potential of Cd2SSe crosses the potential for the redox reaction of water; Applying biaxial tensile strain enhances its light absorption efficiency and reduces the band gap, thereby increasing the performance of photocatalytic water splitting. Each step of the HER and OER reaction process with Cd2SSe as a catalyst can be carried out spontaneously under light conditions. The results indicate that the three Janus monolayers hold significant promise in next-generation optoelectronic devices and photocatalysts.

Synergistic Ability and Effect of Leaf Color and Leaf Thickness to Improve the Photosynthetic Performance of Wheat

Leaf traits are important factors affecting the photosynthetic capacity of crops. In Bainong 4199 (BN4199) and Aikang 58 (AK58) wheat, the role of leaf color and leaf thickness in improving wheat photosynthetic performance and its influence on material accumulation and yield were studied in the field environment. Compared with AK58, BN4199 has a deeper leaf color and thicker leaves. Further study on photosynthetic physiological characteristics showed that the photosynthetic capacity of BN4199 with deep color and thick leaves was higher than that of AK58 at flowering stage, 7 days after flowering, 15 days after flowering, and 20 days after flowering regardless of low light in the morning and evening or light at noon. During the flowering stage, the light saturation point and compensation point were 1% higher and 15.23% lower, respectively, in BN4199 than AK58. According to the diurnal variation in chlorophyll content in different growth stages, BN4199 was generally higher than AK58, and the chlorophyll content was the highest at each time point 7 days after flowering. The chlorophyll content was highest at each time point 7 days after flowering. Chlorophyll fluorescence parameters and light reflectance analyses indicated that BN4199 has significantly higher photosynthetic electron transport and population light energy absorption and utilization capacity than AK58. The 2-year field yields indicated significantly higher material accumulation in BN4199 than AK58. In summary, thick leaves with deep color were resistant to both strong light and weak light, thus, markedly increasing photosynthetic efficiency. Improvement in leaf color and leaf thickness might serve as an important index to enhance the photosynthetic performance of wheat, and achieve improvement and breeding of wheat with high light efficiency.

High light availability offsets low naturalness regarding diversity but cannot compensate for reduced ecological value: A case study of near-natural forests and tree plantations in Serbia

High light availability offsets low naturalness regarding diversity but cannot compensate for reduced ecological value: A case study of near-natural forests and tree plantations in Serbia

Genome-Wide Characterization and Expression Profiling of YTH Domain-Containing RNA-Binding Protein Family in Taxus chinensis

N6-methyladenosine (m6A), the most common internal RNA modification in eukaryotes, plays a vital role in post-transcriptional regulation. The YT521-B homology (YTH) domain plays a pivotal role in the methylation-dependent recognition of m6A. In this study, we performed an in-depth analysis of the YTH domain-containing RNA-binding protein family in Taxus chinensis (T. chinensis), a species renowned for its rich content of taxol, a significant compound in cancer therapy. We identified and analyzed six YTH domain-containing proteins in T. chinensis, elucidating their phylogenetic relationships, conserved domain, gene structures, conserved motifs, and chromosomal locations. The prion-like domain analyses provided insights into their potential functions in liquid–liquid phase separation and mRNA metabolism. Quantitative tissue analysis revealed TcYTH1 as the most highly expressed gene among the six TcYTH members. Additionally, we investigated the expression profiles of TcYTH genes under various stress conditions, such as high light, ABA, and PEG treatments. The expression levels of all TcYTH genes changed significantly under stress, revealing their involvement in stress response mechanisms. Our research provides novel insights into the YTH genes family in T. chinensis, emphasizing their potential roles in growth regulation and stress tolerance. The identification and analysis of these genes lay the groundwork for future studies on their functional roles in plant biology.

Cryo-EM structure of the NDH-PSI-LHCI supercomplex from Spinacia oleracea.

The nicotinamide adenine dinucleotide phosphate (NADPH) dehydrogenase (NDH) complex is crucial for photosynthetic cyclic electron flow and respiration, transferring electrons from ferredoxin to plastoquinone while transporting H+ across the chloroplast membrane. This process boosts adenosine triphosphate production, regardless of NADPH levels. In flowering plants, NDH forms a supercomplex with photosystem I, enhancing its stability under high light. We report the cryo-electron microscopy structure of the NDH supercomplex in Spinacia oleracea at a resolution of 3.0-3.3 Å. The supercomplex consists of 41 protein subunits, 154 chlorophylls and 38 carotenoids. Subunit interactions are reinforced by 46 distinct lipids. The structure of NDH resembles that of mitochondrial complex I closely, including the quinol-binding site and an extensive internal aqueous passage for proton translocation. A well-resolved catalytic plastoquinone (PQ) occupies the PQ channel. The pronounced structural similarity to complex I sheds light on electron transfer and proton translocation within the NDH supercomplex.