Growth Conditions Research Articles

Sucrose supplements modulate the Pseudomonas chlororaphis-Arabidopsis thaliana interaction via decreasing the production of phenazines and enhancing the root auxin response

Management of the plant microbiome may help support food needs for the human population. Bacteria influence plants through enhancing nutrient uptake, metabolism, photosynthesis, biomass production and/or reinforcing immunity. However, information into how these microbes behave under different growth conditions is missing. In this work, we tested how carbon supplements modulate the interaction of Pseudomonas chlororaphis with Arabidopsis thaliana. P. chlororaphis streaks strongly repressed primary root growth, lateral root formation and ultimately, biomass production. Noteworthy, increasing sucrose availability into the media from 0 to 2.4% restored plant growth and promoted lateral root formation in bacterized seedlings. This effect could not be observed by supplementing sucrose to leaves only, indicating that the interaction was strongly modulated by bacterial access to sugar. Total phenazine content decreased in the bacteria grown in high (2.4%) sucrose medium, and conversely, the expression of phzH and pslA genes were diminished by sugar supply. Pyocyanin antagonized the promoting effects of sucrose in lateral root formation and biomass production in inoculated seedlings, indicating that this virulence factor accounts for growth repression during the plant-bacterial interaction. Defence reporter transgenes PR-1::GUS and LOX2::GUS were induced in leaves, while the expression of the auxin-inducible, synthetic reporter gene DR5::GUS was enhanced in the roots of bacterized seedlings at low and high sucrose treatments, which suggests that growth/defence trade-offs in plants are critically modulated by P. chlororaphis. Collectively, our data suggest that bacterial carbon nutrition controls the outcome of the relation with plants.

Comparing physiological responses of acute and chronically stressed diploid and triploid Atlantic salmon (Salmo salar)

We compared the performance and physiological response of diploid and triploid Atlantic salmon (Salmo salar) following 21 days of either unpredictable chronic stress (UCS) or no disturbance (control). Thereafter, all four groups were challenged with a novel acute stressor consisting of crowding, netting and transfer into another tank. Growth was monitored during the 21-day period, and stress response to the novel acute stress challenge was assessed by blood chemistry parameters and pituitary gene expression. Plasma parameters were analyzed before (0) and 15, 30, 45, 60, 90, 120, 240, and 300 min after acute stress induction, whereas gene expression was analyzed at 0, 30, 60, 120, and 240 min. The results showed: a) similar growth rate and condition factor reductions from UCS in triploids and diploids, b) higher post-stress plasma Acth and cortisol levels in triploids compared with diploids, c) wider post-stress fluctuations in most of the other plasma parameters for triploids compared with diploids, particularly for glucose and lactate, d) pomca1, pomcb, crf-r1a and crf-r1b mRNA levels were more upregulated in control diploids than control triploids, and e) only minor changes in pituitary gene expression from UCS in both diploids and triploids, but with a noticeable upregulation of pomca2 and crf-r1a and crf-r1b in the triploids. Our results suggest that triploid Atlantic salmon have a higher energy cost in response to stress than diploids salmon. This can make them more sensitive to suboptimal conditions and episodes of acute and chronic stress.

Feammox bacterial biofilm formation in HFMB

Nitrogen pollution has been increasing with the development of industrialization. Consequently, the excessive deposition of reactive nitrogen in the environment has generated the loss of biodiversity and eutrophication of different ecosystems. In 2005, a Feammox process was discovered that anaerobically metabolizes ammonium. Feammox with the use of hollow fiber membrane bioreactors (HFMB), based on the formation of biofilms of bacterial communities, has emerged as a possible efficient and sustainable method for ammonium removal in environments with high iron concentrations. This work sought to study the possibility of implementing, at laboratory scale, an efficient method by evaluating the use of HFMB. Samples from an internal circulation reactor (IC) incubated in culture media for Feammox bacteria. The cultures were enriched in a batch reactor to evaluate growth conditions. Next, HFMB assembly was performed, and Feammox parameters were monitored. Also, conventional PCR and scanning electron microscopy (SEM) analysis were performed to characterize the bacterial communities associated with biofilm formation. The use of sodium acetate presented the best performance for Feammox activity. The HFMB operation showed an ammonium (NH4+) removal of 50%. SEM analysis of the fibers illustrated the formation of biofilm networks formed by bacteria, which were identified as Albidiferax ferrireducens, Geobacter spp, Ferrovum myxofaciens, Shewanella spp., and Anammox. Functional genes Archaea/Bacteria ammonia monooxygenase, nrxA, hzsB, nirS and nosZ were also identified. The implementation of HFMB Feammox could be used as a sustainable tool for the removal of ammonium from wastewater produced because of anthropogenic activities.

Reduced lung function during childhood in identical twins with discordant fetal growth: a cohort study

Fetal growth restriction (FGR) can negatively affect lung development, leading to increased respiratory morbidity and reduced lung function later in life. Studies regarding the impact of FGR on lung function in singletons are influenced by genetic, obstetric, and maternal factors. To overcome these confounding factors, we aim to investigate lung function in identical twins with selective FGR (sFGR). Lung function assessments were performed in identical twins with sFGR born in our centre between March 1, 2002, and December 31, 2017, aged between 5 and 17 years. sFGR was defined as birthweight discordance ≥20%. Outcome measures consisted of forced expiratory volume in 1s (FEV1), forced vital capacity (FVC), and transfer factor for carbon monoxide (DLCO) and were compared between the smaller and larger twin. Thirty-nine twin pairs performed spirometry of sufficient quality. Median gestational age at birth was 34.3 (interquartile range (IQR) 32.1-36.0) weeks with median birthweights of 1500 (IQR 1160-1880) grams and 2178 (IQR 1675-2720) grams for the smaller and larger twin, respectively. Smaller twins had significantly lower z-scores for FEV1 (-0.94 versus-0.41, p=0.0015), FVC (-0.56 versus-0.06, p<0.0001) and DLCO (-0.50 versus 0.00, p<0.0001) compared to larger co-twins. Although being genetically identical, sFGR in identical twins is associated with a reduction in static and dynamic lung volume and a reduction in lung diffusion, even when taking the reduced lung volume into account. This indicates that adverse growth conditions in utero negatively affect lung development and function, potentially contributing to an increase in respiratory morbidities later in life. The Dutch Heart Foundation and The Bontius Foundation.

Templated Growth of In2S3 in Ti3C2TX MXene with Enhanced Photocatalytic Properties

The growth of ultrathin semiconductors is advantageous for photocatalysis due to improved photophysical properties and reduced charge recombination. Along these lines, templating the growth of semiconductors in confined spaces can allow control over semiconductor growth while also conferring the properties of the template to provide composite nanomaterial hybrids. Herein, the semiconductor In2S3 is grown in the organically‐modified interlayer space of Ti3C2TX MXene, a versatile 2D material with metallic character and broadband light absorption. The growth of 1–2 nm thick layers of In2S3 in the interlayer of MXene leads to a drastic increase in photocatalytic properties and light‐induced charge generation due to decreased interfacial charge transfer resistance. Interestingly, the hydrothermal conditions of In2S3 growth lead to partial oxidation of Ti3C2TX MXene to form anatase TiO2 nanocrystals, although this effect is strongly limited by increased In2S3 precursors due to passivation of the MXene surface. MXenes serve as effective templates for the confined growth of semiconductors, emphasizing the potential of MXene as a template for 2D material heterostructures. Overall, this work further develops MXene‐based 2D material composites, offering insights into the origins of the enhanced photocatalytic and photoelectrochemical properties, toward improvements in energy production and aqueous phase catalysis.

MYCOLOGICAL ANALYSIS OF CYSTIC CONTENT IN PATIENTS WITH POLYMICROCYSTIC CHANGES OF THE MAXILLARY SINUS MUCOSA

The prevalence of mycotic infections of the paranasal sinuses is constantly increasing worldwide. Pathogens can enter the sinuses through the respiratory tract that leads to the colonization of microorganisms in both the lungs and paranasal sinuses as part of the normal microflora. The presence of filamentous fungi in the maxillary sinus may result from endodontic treatment of molars directly adjacent to the sinus, increasing the risk of fungal foci development. Fungal paranasal sinusitis manifests in invasive or non-invasive forms. While mycological culture remains the traditional gold standard for mycosis diagnosis, its sensitivity is reportedly low. Paranasal sinus cysts comprise 4-8% of general ENT pathologies and approximately 4-16% of chronic paranasal sinus diseases, with a predominant presence in the maxillary sinus. Factors that contribute to the development of sinusitis and create favorable conditions for fungal spore adhesion and growth include impaired ventilation and transport function of the sinus mucosa, inadequate use of broad-spectrum antibacterial drugs and steroid therapy, as well as household factors. Recently, there has been an increase in the number of cases of multiple small cysts in maxillary sinuses. Clinical manifestations range from asymptomatic incidental findings to varying degrees of discomfort and/or pain localized in the maxillary sinus area. The aim of this study is to identify the involvement of a fungal agent and to develop a set of therapeutic and prophylactic measures for polymicrocystic changes in the mucous membrane of the maxillary sinuses. The study enrolled 37 patients aged 18 to 65 years. Atypical cystic content was collected and cultured in Sabouraud's nutrient broth and Amies transport medium at 35-37°C for 5-7 days, with final measurements on day 21. Treatment involved a 14-day regimen of itraconazole (100 mg once daily) alongside topical miramistin (0.01% solution, 2 ml) sinus injections. The findings obtained demonstrate the following: positive fungal growth was observed in 26 cases (70.3%), predominantly Penicillium (48.6%) and Aspergillus (21.6%). Absence of growth was noted in 11 cases (29.7%). Follow-up examinations in 6 months and in a year revealed no crusts in the nasal cavity, moderate mucous discharge in the sinuses, and no polymicrocystic changes. Conclusion. The analysis has demonstrated the involvement of fungal flora in the development and recurrence of cystic changes in the maxillary sinus mucosa, advocating for mycological examination alongside bacteriological analysis. Itraconazole for systemic therapy and miramistin for topical therapy demonstrate efficacy in treatment and recurrence prevention.

Inventory of Pests and Parasites in the Cultivation of Hotate Shellfish (&lt;i&gt;Patinopecten yessoensis&lt;/i&gt;) in Funka Bay, Hokkaido, Japan

Hotate Shellfish Cultivation is the largest shellfish cultivation in the world, but many pests and parasites are found. This research aims to inventory the types of pests and parasites found in the cultivation of Hotate Shellfish (Patinopecten yessoensis) in Funka Bay, Hokkaido, Japan. The objects used for this research were 54 Hotate shellfish, consisting of three life stages of shellfish, namely seed shellfish, juvenile shellfish, and adult shellfish. This research was carried out using observation and random sampling methods to determine the types and percentages of pests and parasites present during the research. This research was carried out for seven months from 13 April to 6 December 2022 at the Daisan Matsui Company, Ohama, Oshamambe, Hokkaido, Japan. The results of this research show that there are four types of pests, namely Starfish, Purple Shellfish, Crustaceans, and Sea Pineapples as well as two types of parasites, namely Annelid Worms and Barnacles which attack shellfish cultivation. The percentage of shellfish at three life stages that were attacked by parasites was 75.93%. There are several factors that control the attachment of pests and parasites, including substrate availability, nutrient availability, and environmental considerations. The surfaces and nutrients provided by hotate culture facilities provide adequate conditions for pest settlement and growth.

Epigenome editing revealed the role of DNA methylation of T-DMR/CpG island shore on Runx2 transcription

RUNX2 is a transcription factor crucial for bone formation. Mutant mice with varying levels of Runx2 expression display dosage-dependent skeletal abnormalities, underscoring the importance of Runx2 dosage control in skeletal formation. RUNX2 activity is regulated by several molecular mechanisms, including epigenetic modification such as DNA methylation. In this study, we investigated whether targeted repressive epigenome editing including hypermethylation to the Runx2-DMR/CpG island shore could influence Runx2 expression using Cas9-based epigenome-editing tools. Through the transient introduction of CRISPRoff-v2.1 and gRNAs targeting Runx2-DMR into MC3T3-E1 cells, we successfully induced hypermethylation of the region and concurrently reduced Runx2 expression during osteoblast differentiation. Although the epigenome editing of Runx2-DMR did not impact the expression of RUNX2 downstream target genes, these results indicate a causal relationship between the epigenetic status of the Runx2-DMR and Runx2 transcription. Additionally, we observed that hypermethylation of the Runx2-DMR persisted for at least 24 days under growth conditions but decreased during osteogenic differentiation, highlighting an endogenous DNA demethylation activity targeting the Runx2-DMR during the differentiation process. In summary, our study underscore the usefulness of the epigenome editing technology to evaluate the function of endogenous genetic elements and revealed that the Runx2-DMR methylation is actively regulated during osteoblast differentiation, subsequently could influence Runx2 expression.

Machine Learning-Powered Forecasting of Climate Conditions in Smart Greenhouse Containing Netted Melons

The greenhouse environment plays a crucial role in providing favorable conditions for crop growth, significantly improving their quality and yield. Accurate prediction of greenhouse environmental factors is essential for their effective control. Although artificial intelligence technologies for predicting greenhouse environments have been researched recently, there are limitations in applying these to general greenhouse environments due to computing resources or issues with interpretability. Moreover, research on environmental prediction models specifically for melon greenhouses is also lacking. In this study, machine learning models based on MLR (Multiple Linear Regression), SVM (Support Vector Machine), ANN (Artificial Neural Network), and XGBoost were developed to predict the internal temperature, relative humidity, and CO2 conditions of melon greenhouses 30 min in advance. The XGBoost model demonstrated high accuracy and stability, with an R2 value of up to 0.9929 and an RPD (Residual Predictive Deviation) of 11.8464. Furthermore, the analysis of the XGBoost model’s feature importance and decision trees revealed that the model learned the complex relationships and impacts among greenhouse environmental factors. In conclusion, this study successfully developed a predictive model for a greenhouse environment for melon cultivation. The model developed in this study can facilitate an understanding and efficient management of the greenhouse environment, contributing to improvements in crop yield and quality.

Combined effect of light and glyphosate herbicide on growth rate of marine diatom algae.

The effect of glyphosate herbicide at concentrations of 25, 100, 150 and 200 μg.L-1 on growth characteristics of diatoms C. caspia and T. weissflogii under accumulative growth conditions was investigated. Increasing herbicide concentration in the medium resulted in growth suppression of both species and decreased the final abundance of the cultures in the stationary growth phase. The calculated concentrations of herbicide EC10 and EC50 (10 and 90 μg.L-1 for C. caspia and 7 and 25 μg·L-1 for T. weissflogii, respectively) led to a 10 and 50% reduction in the abundance of the studied cultures relative to the control, are ecologically significant and correspond to the values recorded in aquatic areas. The combined effect of light (in the range of 20-250 µE.m-2.s-1) and glyphosate (calculated concentrations of EC10 and EC50) on the growth characteristics of microalgae was evaluated. An increase in algal sensitivity to light was observed with glyphosate exposure. In both species, the increase in the concentration of glyphosate in the medium led to a decrease in the initial angle of slope of the light curve of growth under conditions of light limitation, a reduction in the value of light saturation of growth, narrowing of the boundaries of the light optimum and an increase in the degree of light inhibition. It is shown that the effect of the combined action of light and glyphosate exceeds the sum of the effects of each factor. This fact should be taken into account in ecotoxicological monitoring when assessing the risks of glyphosate ingress into aquatic ecosystems. An increase in glyphosate concentration in water during periods with high values of solar insolation is potentially dangerous due to a decrease in the photosynthetic activity of algae and a reduction in diatom algae abundance.

Regularity results for Hölder minimizers to functionals with non‐standard growth

AbstractWe study the regularity properties of Hölder continuous minimizers to non‐autonomous functionals satisfying ‐growth conditions, under Besov assumptions on the coefficients. In particular, we are able to prove higher integrability and higher differentiability results for solutions to our minimum problem.

Precision Regulation and Forecasting of Greenhouse Tomato Growth Conditions Using an Improved GA-BP Model

Tomatoes are annual herbaceous plants of the family Solanaceae. They have very stringent requirements for their growing environment and climate conditions. To precisely control the greenhouse environment for tomato growth, this project designed and implemented a monitoring system utilizing programmable logic controllers and a data acquisition system for monitoring. Sensors are installed at key locations in the greenhouse, such as near the ground, in the plant canopy, and under the roof, to monitor environmental parameters such as temperature, humidity, light intensity, and carbon dioxide concentration in real time. A three-layer feedforward GA-BP neural network model was established using soil temperature, soil humidity, air humidity, and illumination as predictive parameters. This technology predicts optimal environmental parameters and performs real-time monitoring and intelligent control, overcoming the traditional BP neural network’s drawbacks of slow convergence, susceptibility to disturbance, and poor generalization ability, with the current model’s average prediction error being less than 5%. It provides a theoretical basis and decision support for precision control and related environmental forecasting in agricultural projects. Based on the growth characteristics, physiological and morphological features of tomatoes, and the comprehensive impact of planting conditions, the technology enhances tomato yield and quality while reducing production costs and labor inputs. It mainly includes the establishment of tomato growth models, measurement and control of environmental parameters, and the design and optimization of intelligent decision control systems. Research outcomes in this field are significant for improving agricultural production efficiency, ensuring food security, and promoting sustainable agricultural development.

Environmental controls and phenology of sea ice algal growth in a future Arctic

The future of Arctic sea ice algae is examined using a regional ocean and sea ice biogeochemical model, with a simulation from 1980 to 2085, considering a future scenario with strong warming. To analyze the impacts of climate change, we computed key dates in the development of sympagic blooms, corresponding to the occurrence of specific growth conditions, and designed diagnostics of ice algal phenology to estimate the onset and peak of blooms. These diagnostics help understand how the timing of light and nutrient availability governs the growth of ice algae and how environmental controls will be altered by climate change across regions. With thinner ice, photosynthetically active radiation in bottom ice will reach levels sufficient for growth earlier, resulting in a better synchrony of high levels of light and nutrients. Increases in snow cover can potentially offset the effect of thinner ice, leading to shorter periods of favorable growth conditions in certain regions. The loss of sea ice cover before the late 21st century only impacts sympagic blooms at lower latitudes, as the timing of sea ice break-up shows little change relative to other key dates at higher latitudes. In response to climate change, the model simulates a modified spatial distribution of blooms, with the emergence of highly productive areas and the loss of blooms in other regions. However, the changes in the timing of growth conditions do not substantially alter the timing of blooms, and both onset and peak ice algae see little change. The simulated lack of sensitivity of bloom onset is attributed to the delay in sea ice freeze-up projected by the model, causing a reduction of overwintering ice algae. The resulting lower initial biomass at the beginning of spring then causes a delay in the development of blooms, offsetting earlier light from thinner ice.

The Prospects and Challenges for Ambi‐Polar Vacancy‐Ordered Double Perovskite Cs2SnI6 towards Realization of High Efficiency Air‐Stable Solar‐Cells

The rapid advancements in material research for lead‐free inorganic metal halide perovskites have fuelled the pathway to design environmentally‐benign solar‐cells to cater the energy requirements for future generations. The vacancy‐ordered double perovskite Cs2SnI6 with an optimum band‐gap (∽1.3 eV), high absorption coefficient (∽105 cm‐1), ambi‐polar charge carrier transport, high structural and compositional stability coupled with simple cost‐effective solution‐based synthesis techniques seems to be an excellent candidate to design air‐stable high‐efficiency solar‐cell based applications. The review focusses on the structure‐property relationship in Cs2SnI6; and its critical dependency on growth precursors, conditions and methods. The recent advancements in material and additive engineering to obtain phase‐pure uniform continuous smooth Cs2SnI6 films; and myriad methods to modulate its opto‐electronic properties are summarized. The nature, origin and type of charge‐carriers in intrinsic and doped Cs2SnI6 is extensively discussed. The application of Cs2SnI6 in dye sensitized solar‐cell (DSSC) and planar perovskite solar‐cell (PSC) configurations are critically reviewed; and its recent progress and challenges to achieve ultimate theoretical Shockley‐Queisser limit of 30‐33% is presented. The recent experimental findings on the stability and performance of Cs2SnI6‐based solar‐cells under ambient and controlled conditions would be discussed to highlight its feasibility for the design and development of air‐stable high‐efficiency solar‐cells.This article is protected by copyright. All rights reserved.

The use of He buffer gas for moderating the plume kinetic energy during Nd:YAG-PLD growth of EuxY2−xO3 phosphor films

We have investigated the He buffer gas process of moderating the kinetic energy of the pulsed laser deposition (PLD) plume during EuxY2−xO3 phosphor film growth. When using a neodymium yttrium aluminum garnet laser for PLD thin film growth, the kinetic energy of the ablation plumes can be high enough to cause the formation of point defects in the film. The buffer gas pressure is an important process parameter in PLD film growth. We find that the presence of the He buffer gas reduces the kinetic energy of the laser deposition plume through many low-angle collisions in the gas phase by a factor of 7 without reducing the deposition rate. This is because He is much lighter than any of the elements in the plume and it does not affect the composition of the oxide films. Consequently, the resputtering of the Y2O3 film surface by the plume was significantly suppressed in the presence of the He gas moderator, leading to a decrease of the defect density in the Y2O3 films. The improvement of the film quality was verified by a systematic analysis of time-resolved photoluminescence (PL) data for EuxY2−xO3 composition–gradient films. The PL lifetime and intensity of Eu0.2Y1.8O3, which shows the highest PL intensity, increased by 13.3% and 36.4%, respectively, when the He gas moderation process was used. The He buffer gas process is applicable to the PLD growth of the other oxide materials as well, where the reduction of the kinetic energy of the plume would bring the PLD process closer to the molecular beam epitaxy growth condition.

Detection and classification of wilting status in leaf images based on VGG16 with EfficientNet V3 algorithm

The aim of this paper is to explore the importance of leaf wilting status detection and classification in agriculture to meet the demand for monitoring and diagnosing plant growth conditions. By comparing the performance of the traditional VGG16 image classification algorithm and the popular EfficientNet V3 algorithm in leaf image wilting status detection and classification, it is found that EfficientNet V3 has faster convergence speed and higher accuracy. As the model training process proceeds, both algorithms show a trend of gradual convergence of Loss and Accuracy and increasing accuracy. The best training results show that VGG16 reaches a minimum loss of 0.288 and a maximum accuracy of 96% at the 19th epoch, while EfficientNet V3 reaches a minimum loss of 0.331 and a maximum accuracy of 97.5% at the 20th epoch. These findings reveal that EfficientNet V3 has a better performance in leaf wilting status detection, which provides a more accurate and efficient means of plant health monitoring for agricultural production and is of great research significance.

Activity-based protein profiling of serine hydrolases and penicillin-binding proteins in Enterococcus faecium

Abstract Enterococcus faecium is a gut commensal bacterium that is gaining increasing relevance as an opportunistic, nosocomial pathogen. Its high level of intrinsic and acquired antimicrobial resistance is causing a lack of treatment options, particularly for infections with vancomycin-resistant strains, and prioritizes the identification and functional validation of novel druggable targets. Here, we use activity-based protein profiling (ABPP), a chemoproteomics approach using functionalized covalent inhibitors, to detect active serine hydrolases across 11 E. faecium and Enterococcus lactis strains. Serine hydrolases are a big and diverse enzyme family, that includes known drug targets such as penicillin-binding proteins (PBPs), whereas other subfamilies are underexplored. Comparative gel-based ABPP using Bocillin-FL revealed strain- and growth condition dependent variations in PBP activities. Profiling with the broadly serine hydrolase-reactive fluorescent probe fluorophosphonate-TMR showed a high similarity across E. faecium clade A1 strains, but higher variation across A2 and E. lactis strains. To identify these serine hydrolases, we used a biotinylated probe analog allowing for enrichment and identification via liquid chromatography-mass spectrometry. We identified 11 largely uncharacterized targets (α,β-hydrolases, SGNH-hydrolases, phospholipases, amidases, peptidases) that are druggable and accessible in live vancomycin-resistant E. faecium E745 and may possess vital functions that are to be characterized in future studies.

Dynamics of growing carbon nanotube interfaces probed by machine learning-enabled molecular simulations

Carbon nanotubes (CNTs), hollow cylinders of carbon, hold great promise for advanced technologies, provided their structure remains uniform throughout their length. Their growth takes place at high temperatures across a tube-catalyst interface. Structural defects formed during growth alter CNT properties. These defects are believed to form and heal at the tube-catalyst interface but an understanding of these mechanisms at the atomic-level is lacking. Here we present DeepCNT-22, a machine learning force field (MLFF) to drive molecular dynamics simulations through which we unveil the mechanisms of CNT formation, from nucleation to growth including defect formation and healing. We find the tube-catalyst interface to be highly dynamic, with large fluctuations in the chiral structure of the CNT-edge. This does not support continuous spiral growth as a general mechanism, instead, at these growth conditions, the growing tube edge exhibits significant configurational entropy. We demonstrate that defects form stochastically at the tube-catalyst interface, but under low growth rates and high temperatures, these heal before becoming incorporated in the tube wall, allowing CNTs to grow defect-free to seemingly unlimited lengths. These insights, not readily available through experiments, demonstrate the remarkable power of MLFF-driven simulations and fill long-standing gaps in our understanding of CNT growth mechanisms.

A Simple Method for Estimating Stomatal Aperture from Temperature Measurements on Intact Leaves and Wet and Dry Artificial Reference Leaves

Environmental control in greenhouse horticulture is essential for providing optimal conditions for plant growth and achieving greater productivity and quality. To develop appropriate environmental management practices for greenhouse horticulture through sensing technologies for monitoring the environmental stress responses of plants in real time, we evaluated the relative value of the stomatal opening to develop a technology that continuously monitors stomatal aperture to determine the moisture status of plants. When plants suffer from water stress, the stomatal conductance of leaves decreases, and transpiration and photosynthesis are suppressed. Therefore, monitoring stomatal behavior is important for controlling plant growth. In this study, a method for simply monitoring stomatal conductance was developed based on the heat balance method. The stomatal opening index (SOI) was derived from heat balance equations on intact tomato leaves, wet reference leaves, and dry reference leaves by measuring their temperatures in a growth chamber and a greenhouse. The SOI can be approximated as the ratio of the conductance of the intact leaf to the conductance of the wet reference leaf, which varies from 0 to 1. Leaf temperatures were measured with infrared thermometry. The theoretically and experimentally established SOI was verified with tomato plants grown hydroponically in a greenhouse. The SOI derived by this method was consistent with the leaf conductance measured via the porometer method, which is a standard method for evaluating actual leaf conductance that mainly consists of stomatal conductance. In conclusion, the SOI for the continuous monitoring of stomatal behavior will be useful not only for studies on interactions between plants and the environment but also for environmental management, such as watering at plant production sites.

Adaptability parameters of the trait ‘1000-grain weight’ of spring barley in the conditions of the Ryazan region

The purpose of the current work was to study the ecological adaptability and stability of the trait ‘1000-grain weight’ of spring barley varieties of different ecological and geographical origins over three years of research in the conditions of the Ryazan region. To analyze and study this issue 26 varieties of the collection nursery were studied on the fields of the laboratory of breeding and primary seed production of ISA, a branch of the FSBI FRAEC VIM, located in the forest-steppe agroclimatic zone of the Ryazan region in 2021–2023. To calculate the adaptability parameters, there were used the following coefficients and indicators: adaptability coefficient (AC), yield range (d, %), homeostatic index (Homi), variety yield stability level index (VISLi, %), environmental adaptability (a linear regression coefficient) (bi), stability of the trait (σd2), index of environmental conditions (Ij), stability factor (SF), genetic flexibility of the variety (Ymin+Ymax/2), stress resistance (Ymin–Ymax) and coefficient of responsiveness to favorable growing conditions (Cr), calculated using appropriate methods. The study has established that the dominant influence (66.4 %) on the variability of the trait ‘1000-grain weight’ of the studied varieties is made by the factor “year” (growth and development conditions). A significant contribution to the formation of the indicator “weight of 1000 grains” is made by the meteorological conditions of the grain filling phase (July) – HTC (r = +0.722 p = 0.01) and the amount of precipitation (r = +0.637, p = 0.01). 80.8 % of the 26 varieties studied belonged to the large-grain group (1000-grain weight was more than 50.0 g), the average varietal yield of the varieties was quite high with 6.84 t/ha. Based on the principle of ranking the obtained indicators of adaptability of the trait ‘1000-grain weight’ and its components, there were identified the varieties ‘Dobry’, ‘Magutny’ (Republic of Belarus) and ‘Lenetah’ (USA), which took, respectively, first, second and third places in the rating scale. It can be recommended to involve these varieties in a breeding crossbreeding program to increase grain size.