Changes In Light Intensity Research Articles

Cyclic electron flow compensates loss of PGDH3 and concomitant stromal NADH reduction.

In nature plants constantly experience changes in light intensities. Low illumination limits photosynthesis and growth. However, also high light intensities are a threat to plants as the photosynthetic machinery gets damaged when the incoming energy surpasses the capacity of photochemistry. One limitation of photochemistry is the constant resupply of stromal electron (e-) acceptors, mainly NADP. NADP is reduced at the acceptor-side of photosystem I. The resulting NADPH is utilized by the Calvin-Benson-Bassham cycle (CBBC) and the malate valve to ensure sufficient oxidized NADP ready to accept e- from PSI. Lately, additional pathways, which function as stromal e- sinks under abiotic stress conditions, were discovered. One such reaction in Arabidopsis thaliana is catalyzed by PHOSPHOGLYCERATE DEHYDROGENASE 3 (PGDH3), which diverts e- from the CBBC into NADH. pgdh3 loss-of-function mutants exhibit elevated non-photochemical quenching (NPQ) and fluctuating light susceptibility. To optimize plant photosynthesis in challenging environments knowledge on PGDH3's metabolic integration is needed. We used the source of high NPQ in pgdh3 as a starting point. Our study reveals that increased NPQ originates from high cyclic electron flow (CEF). Interestingly, PGDH3 function seems very important when the CEF-generator PROTON GRADIENT REGULATION5 (PGR5) is lost. Consequently, pgr5pgdh3 double mutants are more sensitive to fluctuating light.

Autoencoder-Based System for Detecting Anomalies in Pelletizer Melt Processes.

Effectively identifying and preventing anomalies in the melt process significantly enhances production efficiency and product quality in industrial manufacturing. Consequently, this paper proposes a study on a melt anomaly identification system for pelletizers using autoencoder technology. It discusses the challenges of detecting anomalies in the melt extrusion process of polyester pelletizers, focusing on the limitations of manual monitoring and traditional image detection methods. This paper proposes a system based on autoencoders that demonstrates effectiveness in detecting and differentiating various melt anomaly states through deep learning. By randomly altering the brightness and rotation angle of images in each training round, the training samples are augmented, thereby enhancing the system's robustness against changes in environmental light intensity. Experimental results indicate that the system proposed has good melt anomaly detection efficiency and generalization performance and has effectively differentiated degrees of melt anomalies. This study emphasizes the potential of autoencoders in industrial applications and suggests directions for future research.

Acclimation of the Resurrection Plant Haberlea rhodopensis to Changing Light Conditions.

Resurrection plants present an attractive model for studying the mechanisms of desiccation tolerance. In addition to drought, the presence of light during desiccation is extremely dangerous. In the present study, we investigated the effect of light during the desiccation of shade and sun Haberlea rhodopensis from two different habitats by measuring the changes in electrolyte leakage, malondialdehyde and proline content, and photosynthetic and antioxidant activities. Moreover, the plasticity and acclimation ability of plants to changing light intensities were studied by desiccating shade plants under high light and sun plants under low light. The most significant differences between shade and sun plants were observed under moderate dehydration. Regardless of some decline in PSII activity in sun plants, it was much higher compared to shade plants. The lower PSII efficiency in the latter was accompanied by a higher extent of excitation pressure and consequently significant enhancement in non-photochemical quenching, Y(NPQ), and especially in the fraction of energy that is passively dissipated as heat and fluorescence, Y(NO). The activity of antioxidant enzymes remained high during the desiccation of H. rhodopensis, being higher in the sun compared to shade plants in an air-dried state. In addition, shade and sun plants showed high acclimation capacity when desiccated at opposite light intensities.

The interfacial behaviors of ball-milled gorgon euryale starch - Quinoa protein complex and its stabilizing effect on Pickering emulsions

This study investigated the effects of ball-milling treatment on the characteristics of gorgon euryale starch (GES) and quinoa protein (QP), and developed a new strategy by compounding ball-milled GES with QP to study the mechanism of its action on the stability of Pickering emulsions. Through SEM and FTIR analyses, it was found that ball-milling treatment damaged the compound granular structure of GES, reduced the particle size of QP, and caused aggregation. However, the chemical structures of both substances did not change significantly. The Pickering emulsions prepared with the ball-milled GES/QP complex exhibited more significant thickening properties. Ball milling reduced the droplet size of the emulsions (D50 decreased from 6.73 ± 0.12 to 2.85 ± 0.91 μm) and made the distribution more uniform, though an excessive protein ratio led to droplet aggregation and a decrease in the emulsification index. Using the emerging observation method of DIC, it was confirmed that the emulsions prepared with GES/QP (8/2, g/g) and GES/QP (7/3, g/g) showed almost no change in backscattering light intensity and still had good storage stability after 20 days. This study provides a theoretical basis for the development of more stable and clean emulsifiers.

Elevated Heterotrophic Prokaryotic Production Supported by Low Nucleic Acid Prokaryotes at a Cyclonic Eddy Edge in the Northwest Pacific

AbstractThe cyclonic eddy uplifts nutrient‐rich seawater into the euphotic zone, typically directly enhancing phytoplankton abundance and primary production. However, its impact on heterotrophic prokaryotic production (HPP) remains unclear due to the complex interplay of multiple indirect factors governing this process. Here, we conducted a comprehensive investigation of the distribution of picophytoplankton and heterotrophic prokaryotes, prokaryotic community structure, and HPP within a cyclonic eddy in the western North Pacific subtropical gyre. The results indicated that despite the higher abundance of picophytoplankton accompanied by nutrient upwelling at the eddy core compared to the edge, higher levels of HPP were observed at the eddy edge between 100 and 200 m, consistent with the distribution of the low nucleic acid content (LNA) prokaryotes. The significant positive correlation between HPP and the proportion of LNA group in total heterotrophic prokaryotes suggested a primary contribution from the LNA group over the high nucleic acid content (HNA) group. SAR11, a typical member of the LNA group, may primarily contribute to the elevated HPP observed at the eddy edge. The changes in temperature, nutrients, and light intensity induced by the cyclonic eddy may significantly influence the distribution and activity of HNA and LNA groups, potentially exerting a greater impact on HPP compared to phytoplankton‐related factors. These findings contribute to understanding the underlying mechanisms of HPP responses to cyclonic eddies in the oligotrophic open ocean.

Revealing the adaptation mechanism of different color morphs of sea cucumber Apostichopus japonicus to light intensities from the perspective of metabolomics

Global warming has multi-dimensional and complex impacts on the Earth's system, among which changes in light intensities cannot be overlooked. Sea cucumbers are a marine biological resource with significant economic and ecological value. Their presence and activity help maintain the balance and stability of marine ecosystems. The variation in light intensities have important ecological effects on sea cucumbers. Light intensities can alter the synthesis and degradation of metabolic substances within the bodies of Apostichopus japonicus by changing their body color. Their changes affect the production of microorganisms in the environment, thereby achieving the goal of bioremediation. This study investigated metabolic variations in green, purple, and white sea cucumber Apostichopus japonicus under different light conditions (0 lx and 910 lx) with a 12-h light and 12-h dark photoperiod. The findings indicated that the sea cucumbers displayed more diverse metabolic alterations under 910 lx illumination compared to 0 lx. Specifically, these color morphs primarily responded to changes in light intensities through “tryptophan metabolism” and “biosynthesis of steroid hormones”. Additionally, high light intensities environment exacerbated the consumption of fatty acids by sea cucumbers. Different color morphs of sea cucumbers have differences in key metabolites in response to changes in light intensities. Green and white sea cucumbers primarily adapt to environment through phospholipids, while purple sea cucumbers mainly utilize fatty acids. These results enhance our comprehension of how sea cucumbers adapt ecologically to varying light intensities, and they offer valuable insights for systematically uncovering the regulatory processes that marine animals employ in response to environmental changes.

Two critical membranes. How does the chloroplast envelope affect plant acclimation properties?

Chloroplasts play a pivotal role in the metabolism of leaf mesophyll cells, functioning as a cellular hub that orchestrates molecular reactions in response to environmental stimuli. These organelles contain complex protein machinery for energy conversion and are indispensable for essential metabolic pathways. Proteins located within the chloroplast envelope membranes facilitate bidirectional communication with the cell and connect essential pathways, thereby influencing acclimation processes to challenging environmental conditions such as temperature fluctuations and light intensity changes. Despite their importance, a comprehensive overview of the impact of envelope-located proteins during acclimation to environmental changes is lacking. Understanding the role of these proteins in acclimation processes could provide insights into enhancing stress tolerance under increasingly challenging environments. This review highlights the significance of envelope-located proteins in plant acclimation.

Preparation of Imidazole Compounds as Latent Curing Agents and Their Application in RGB LED Packaging.

LED packaging miniaturization has raised more requirements for LED materials. As a material contacting the LED chip directly, the reliability of LED non-conductive adhesive has also garnered increasing attention. This study optimized the formula for non-conductive adhesives for an imidazole curing system. The optimized composition of the adhesive is 25%wt for the curing agent and 30%wt for the silica. The prepared non-conductive adhesive has a 7-day pot life and 9-month storage stability. The shear strength reached 87 g and 72 g at 25 °C and 160 °C, respectively. The reliability of the LED modules packaged with the non-conductive adhesive was researched. The green and blue light intensity change was 4.7%, 43.7%, respectively, indicating good anti-aging properties. The blue light decay was mainly due to adhesive aging. The non-conductive adhesive effectively prevented "caterpillar" growth. This provides useful and practical guidelines for industry for applications of adhesive in different packages.

Impact of dicarboxystilbene impurities on the properties of swift heavy ion latent tracks in PET films

We present a new hypothesis and supporting experimental evidence about the essential role played by small impurities of dicarboxystilbene in the process of UV treatment of PET films irradiated with swift heavy ions (SHI). This treatment both forms highly selective membranes with permeability values comparable to natural ones (the track-UV technique) and sharply accelerates the etching of latent tracks in membrane production (the track-etching technique). We hypothesize (1) that these high permeability value is due to the presence of a molecular motor of an Archimedes screw type in the central part of the latent track formed by photoinduced trans-cis isomerization of dicarboxystilbene molecules that are anchored in helical conformations in the latent track; and (2) that the acceleration of etching rates is due to the preferential accumulation of phenanthrene-type molecules in the central part of the latent track due to the existence of a cyclization channel for photoexcited molecules of cis-dicarboxystilbene. In the presence of alkali solution, phenanthrene molecules release electrons which behave as strong anions in aqueous solution, catalyzing alkaline hydrolysis of PET molecules in the central part of the track. We present experimental observations of photoinduced changes in transmission light intensity after track-UV light treatment of both pristine and SHI irradiated PET films that confirm the presence of trans-cis isomerization of dicarboxystilbene molecules and show their contribution to the formation of new helical conformations in SHI irradiated PET films during the light treatment.

Position-dependent roles of somatic cells in phototaxis of Volvox.

A spherical green alga, Volvox, achieves phototaxis via a simple on/off switch of flagellar beating in response to changes in light intensity, without the need for complex signal transduction between cells. Moreover, the alga can change its susceptibility to light in order to adapt to its environment. To identify the mechanisms of susceptibility regulation, experiments were conducted at three different levels: population, individual, and cellular. The light intensity dependence of the average velocity at the population level and that of the change in flow speed obtained at the individual level were consistent, indicating that susceptibility regulation occurred in each Volvox colony. Furthermore, by measuring the probability of stopping flagellar beating when the light intensity was changed, susceptibility regulation was found to result from the properties of somatic cells as differential and adaptive photosensors. These photosensing properties deteriorated from the anterior to the posterior regions of the colony. Considering the mechanical motion of a Volvox colony, the position-dependent ability of somatic cells indicates that the anterior cells play the role of a rudder, whereas the posterior cells play the role of a rower. The position-dependent properties of somatic cells imply an early stage of cell differentiation that allows for an efficient response to changes in the circumstances.

Internet of things (IoT) based saffron cultivation system in greenhouse

Saffron is the world's most expensive and legendary crop that is widely used in cuisine, drugs, and cosmetics. Therefore, the demand for saffron is increasing globally day by day. Despite its massive demand the cultivation of saffron has dramatically decreased and grown in only a few countries. Saffron is an environment-sensitive crop that is affected by various factors including rapid change in climate, light intensity, pH level, soil moisture, salinity level, and inappropriate cultivation techniques. It is not possible to control many of these environmental factors in traditional farming. Although, many innovative technologies like Artificial Intelligence and Internet of Things (IoT) have been used to enhance the growth of saffron still, there is a dire need for a system that can overcome primary issues related to saffron growth. In this research, we have proposed an IoT-based system for the greenhouse to control the numerous agronomical variables such as corm size, temperature, humidity, pH level, soil moisture, salinity, and water availability. The proposed architecture monitors and controls environmental factors automatically and sends real-time data from the greenhouse to the microcontroller. The sensed values of various agronomical variables are compared with threshold values and saved at cloud for sending to the farm owner for efficient management. The experiment results reveal that the proposed system is capable to maximize saffron production in the greenhouse by controlling environmental factors as per crop needs.

Morphophysiological Parameters of Growth and Development of Seedlings of Gleditsia triacanthos L. in the Early Stages of Ontogenesis under Conditions of Changing Lighting Intensity

Background: Gleditsia triacanthos L. is a valuable taxon for agroforestry. This species is promising for the creation of protective plantations and has a wide range of economically valuable traits, in particular, drought tolerance. In this regard, the aim of the work was to evaluate morphophysiological parameters of growth and development of G. triacanthos seedlings at early stages of ontogenesis under conditions of changing light intensity. Methods: To achieve this goal, seeds of G. triacanthos were sown with subsequent selection of individuals for the study possessing homogeneity of genetic structure. Analysis of close relatedness of individuals of G. triacanthos showed low intraspecific diversity by Nei (0.27 to 0.62). To evaluate the development of seedlings of G. triacanthos at early stages of ontogenesis, morphophysiological methods were used. Result: Under unfavorable conditions due to low light, the growth and development of the embryonic root and seedling formation was slow. However, all subphases of G. triacanthos seed organogenesis were passed in 98% of individuals, thus forming seedlings under standard criteria. Accumulation of total chlorophyll content in unfavorable conditions was 3 times less compared to individuals in favorable conditions. At the same time, there was a tendency to increase the sum of chlorophylls in the leaves of G. triacanthos in each experimental group at 30 days (p less than 0.05). As a result, it was revealed that light intensity is a limiting parameter for accelerated growth and development of G. triacanthos seedlings.

Multi-field coupling analysis of photovoltaic cells under long distance and multi-mode laser transmission

Most electronic devices are powered by electricity, and the transfer of energy to related electronic devices is a critical issue. Laser wireless power transmission (LWPT) has a broad prospect in the field of wireless energy transmission, such as distributed charging system (DLC), spacecraft sensor network, satellite-to-satellite communication and medium and long distance power transmission, ground to unmanned aerial vehicle (UAV), and so on. In this paper, a multi-field coupled model of LWPT system for laser transmission at medium and long distances is established. Through the existing LWPT experimental platform and test, the test obtained the correlation coefficient of the I-V relationship formula with the change of light intensity and temperature. On the basis of the modified parameters, the attenuation efficiency of laser power with transmission distance is calculated, and the heat transfer and electrical characteristics of photovoltaic cells are solved by finite element method. It is found that different atmospheric environment and laser transmission distance have obvious effects on the voltage, current and temperature variation of photovoltaic cells. The temperature of a photovoltaic cell has a huge impact on its output efficiency. The temperature can be controlled effectively by setting the laser interval of pulse mode reasonably. The cooling capacity of photovoltaic cells is the key to improve the electrical conversion efficiency of LWPT systems.

LiPro: displaying concurrent image viewing and imperceptible positioning using visible light

Visible light can be used to achieve effective human interaction with projectors. However, current visible light-based projectors for the target positioning either lose the image viewing function or cause abnormal luminance changes perceived by human eyes, which is not practical for real-world applications. Therefore, we propose a smart lighting-based projector system, LiPro, which can display imperceptible target positioning and any image viewing, simultaneously. In a nutshell, we propose what we believe to be a novel color space conversion modulation scheme to transmit the landmark information, which adds δ and −3δ color intensity value on the red (R) channel and blue (B) channel according to the YCbCr color space analysis, so that human eyes are imperceptible to light intensity changes. Then, we propose the dual-channel decision demodulation scheme, which demodulates the received light signals on both the R channel and B channel at the same time to decide and increase the correctness of the landmark recognition. In the end, we use off-the-shelf devices to implement LiPro to evaluate its performance, and results from extensive experiments show that our LiPro can achieve centimeter-level target positioning under any image viewing conditions.

Fabrication of Circular Defects in 2-Dimensional Photonic Crystal Lasers with Convex Edge Structure

We have developed circular defects in 2-dimensional photonic crystal lasers that allow current injection for interconnected optical communications. However, when cleaving the sample to measure the output light, the output light intensity changes due to the cleaving position. In a previous study, we proposed a new end face structure called a convex edge structure. In this paper, we design the electron beam lithography patterns to fabricate this structure. With this design, it is possible to eliminate the effect of different cleaving positions and ensure that the cleavage tolerance is larger than the cleavage position error. We also develop the fabrication technology for this structure, fabricate samples, and measure the output light experimentally. The optical properties of the fabricated sample are similar to well-fabricated samples with normal cleavage edge faces. We are assured that these results contribute to future work such as accurate manufacturing and improving the end face configuration to obtain higher outputs.

Source and mask optimization for stability of reticle and wafer stages.

The relative motion of the reticle stage and wafer stage caused by vibration during the scanning exposure process of the lithography machine is an important factor that affects the imaging quality under limited lithography ability. In this paper, the influence of the vibration of the lithography stage system on the lithography imaging quality is studied. The lithography model including the vibration error of the stage is taken into account in the framework of source and mask optimization (SMO). For the 193-nm immersion lithography machine, combined with different design patterns with a line width of 40 nm and different vibration states of the stage when the lithography machine is exposed, the SMO joint optimization research is carried out, and the robustness of the stage under the limit process after SMO optimization is explored. The research results show that the contrast and relative light intensity change of the limit design figure under the influence of moving standard deviation (MSD) will greatly affect the linewidth at the light intensity threshold and then affect the process window (PW). The SMO including MSD allows the MSD to change in the range of 0-6 nm without changing the PW.

The laser screen imaging measurement system based on arrayed fibers

This paper presents a laser screen imaging measurement system (LSIMS) based on arrayed fibers to measure the velocity and dimension of a flying object. A laser diode is connected to the emission module of the laser screen via a single-mode fiber, then the emitted light beam is collimated into a parallel beam with a lens, this structure is arrayed to form the laser screen. The receiving module of the laser screen employs a cylindrical lens array to converge the collimated beams into a focal line. The input ends of the plastic fibers are arrayed along this focal line, while the output ends are imaged on the sensor of a line scan camera (LSC) through a lens. The LSIMS effectively modulates the process of a flying object passing through the laser screen into the light intensity change in the plastic fibers. The velocity and dimension of the flying object are subsequently measured through the analysis of the image obtained by the LSC. The timing accuracy of the LSIMS is verified through experiments. The velocity and diameter of pellets launched by a slingshot are measured and analyzed for errors.

Construction of a photovoltaic low-voltage grid connected power regulation system based on partition control

Abstract Photovoltaic power generation is a green and renewable power generation mode and has been widely used. However, the power fluctuation of photovoltaic power generation has a significant impact on the power grid, which is very important. Based on the concept of regional control, this paper studies the photovoltaic low-voltage grid-connected power regulation system. The photovoltaic power generation system is divided into multiple regions, and each region is provided with an independent control unit and regulation strategy under the control of multiple control areas. The regional factors are combined, such as light intensity and power voltage. In the case of the city, the impact of the area on the whole is dynamically adjusted to achieve the overall balance of power and the stability of the system. The experimental results show that the photovoltaic low-voltage grid-connected power regulation system constructed by regional control performs well and has a high degree of stability. According to the change in light intensity and load demand, the system can achieve accurate control and distribution of photovoltaic power generation.

Artificial Amacrine Retinal Circuits.

Event-based imaging represents a new paradigm in visual information processing that addresses the speed and energy efficiency shortcomings inherently present in the current complementary metal oxide semiconductor-based machine vision. Realizing such imaging systems has previously been sought using very large-scale integration technologies that have complex circuitries consisting of many photodiodes, differential amplifiers, capacitors, and resistors. Here, we demonstrate that event-driven sensing can be achieved using a simple one-resistor, one-capacitor (1R1C) circuit, where the capacitor is modified with colloidal quantum dots (CQDs) to have a photoresponse. This sensory circuit emulates the motion-tracking function of the biological retina, in which the amacrine cells in the bipolar-to-ganglion synaptic pathway produce a transient spiking signal only in response to changes in light intensity but remain inactive under constant illumination. When extended to a 2D imaging array, the individual sensors work independently and output signals only when a change in the light intensity is detected; hence, the concept of the frame in image processing is thereby removed. In this work, we present the fabrication and characterization of a CQD photocapacitor-based 1R1C circuit that has a spectral response at 1550 nm in the short-wave infrared (SWIR). We report on the key performance parameters including peak responsivity, noise, and optical noise equivalent power and discuss the operating mechanism that is responsible for spiking responses in these artificial retinal circuits. The present work sets the foundation for expanding the bioinspired vision sensor capability toward midwave infrared (MWIR) and long-wave infrared (LWIR) spectral regions that are invisible to human eyes and mainstream semiconductor technologies.

Fabrication of a microfluidic system with in situ-integrated microlens arrays using electrohydrodynamic jet printing

Microfluidic systems with integrated microlenses enhance cellular analysis and observation and have gained significant attention in the biomedical field. However, the integration and design of microlenses in microfluidic systems remain challenging. In this study, we utilize a high-precision electrohydrodynamic jet (E-jet) printing system for in-situ integration of microlens. By incorporating a tilting illumination observation module into the E-jet printing system, the print nozzle can be accurately positioned 10 μm above the microchannel bottom, thereby mitigating the edge effect of the microfluidic channels. We have developed a microfluidic system embedding microlens arrays (MLAs) that enable parallel, multichannel cell counting. The microfluidic system comprises nine channels, each featuring a 50 μm diameter microlens printed along the central axis. Using microlenses enables non-contact cell counting by detecting light-intensity changes. Simulating and optimizing the microfluidic channel size enable cells to align on the centerline of the channel and pass over the focal region of the microlens via inertial forces. As the cells flow through the microlens, the intensity of the focal spots decreases by approximately 50 %. The microfluidic cell-counting system can function independently or be integrated with other microfluidic systems as a unit, thus enhancing the single-cell operational and analytical capabilities of microfluidic systems.