Changes In Content Research Articles

Poplar Leaf Bud Resin Metabolomics: Seasonal Profiling of Leaf Bud Chemistry in Populus trichocarpa Provides Insight Into Resin Biosynthesis.

Trees in the genus Populus synthesize sticky and fragrant resins to protect dormant leaf buds during winter. These resins contain diverse phenolic metabolites, in particular hydroxycinnamate esters and methylated flavonoids. P. trichocarpa leaf bud resin is characterized by methylated dihydrochalcone aglycones. To determine how the resin profile is influenced by seasonal changes, P. trichocarpa lateral leaf bud extracts and secreted surface resin were collected monthly over a one-year cycle. The dihydrochalcones in both sets of extracts were quantified using ultrahigh pressure liquid chromatography - mass spectrometry (UPLC-MS) and other chemical changes monitored using non-targeted metabolomics by ultrahigh pressure liquid chromatography - high resolution mass spectrometry (UPLC-HRMS). The results indicate that the dihydrochalcone content changes over the seasons and that biosynthesis occurs concomitant with bud development in the summer months. Non-targeted metabolomics data confirmed a pattern of dramatic changes in the summer, and further suggested additional periods of substantive biochemical change in the resin. While overall patterns of surface-extracted resin matched that of whole bud extracts, some of the dynamics were shifted in the surface resin samples. This study provides the basis for the use of dihydrochalcones and other identified resin components as metabolic markers for more detailed investigations of resin biosynthesis, secretion and movement to the bud surface.

POSSIBLE NEGATIVE EFFECTS OF THE Calacarus carinatus (PROSTIGMATA: ERIOPHYIDAE) ON THE FIRST HARVESTING OF TEA IN EASTERN BLACK SEA AREA

Tea Camellia sinensis L. is a perennial crop onrush by many arthropod pests. The eriophyid purple tea mite, C. carinatus lead to damage to the fresh tea leaves and had a brownish discoloration and and affected flaovur of tea. It also major tea pest together with Acaphylla theae in Indıa. This study focused on the population situations and chlorophly content changes related to the C. carinatus infestations. Study conducted during one year and collect tea leaves 6 different tea plantation areas in eastern Black Sea area. Individual count and chlorophyll content was performed same day after collecting for avoiding chlorophyll content changing and specimens dying during the preservation period. Study results showed that the C. carinatus found every season but population start to increase early february to reached to peak level end of march. It also showed that the population start to desrease early april and finally remains at very low levels throughout the summer. During the high population density time chlorophyll content was adversely affected by the infestation levels. Density dependent measurements also verify this situation according to the seven density category chlorophyll content. Chlorophyll content of the 0, 0-5 individual category showed the statisticall significant differences than the other density category. This work may help future tea prodution plan and its quality by focusing pest management.

Effect of In Vitro Digestion on Anticancer and Antioxidant Activity of Phenolic Extracts From Latex of Fig Fruit (Ficus carica L.).

In this study, changes in total phenolic content (TPC), phenolic profile, and antioxidant activity and anticancer activity against cervix cancer and colorectal cancer cell lines of phenolic extracts of black and white fig (Ficus carica L.) latex (milk) were investigated during in vitro gastrointestinal digestions for the first time. The findings indicated that the in vitro digestion process exerted a significant effect on TPC of the phenolic extract from white fig milk (WFM-PE) and phenolic extract from black fig milk (BFM-PE), and TPC tended to decrease after in vitro digestion (p<0.05). As consistent with these findings, antioxidant activity (by the CUPRAC method) of the samples decreased (p<0.05) during in vitro digestion. The IC50 value of the undigested BFM-PE was significantly lower than that of the undigested WFM-PE (p<0.05). The undigested and the digested WFM-PE and BFM-PE did not show any cytotoxic activity against normal cells. However, anticancer activity of WFM-PE on cervix and colorectal cancer cell lines (p<0.05) and anticancer activity of BFM-PE against colorectal cancer cell lines decreased after in vitro digestion (p<0.01). On the other hand, the dominant phenolic was catechin hydrate and was syringic acid.

Characterization of glycogen-related glycoside hydrolase glgX and glgB from Klebsiella pneumoniae and their roles in biofilm formation and virulence

Glycogen is a polymer used by bacteria to store excess glucose, playing a crucial role in bacterial growth, stress resistance, biofilm formation, and virulence. In bacteria, the glycoside hydrolase family 13 protein are involved in the synthesis and metabolism of glycogen, respectively. The absence of these enzymes leads to changes in bacterial glycogen content, thereby affecting the growth metabolism of the strain. To date, research on the roles of these glycogen-related glycoside hydrolase genes in the synthesis metabolism and bacterial phenotypes of Klebsiella pneumoniae has been limited. In this study, we characterized the glycogen-related glycoside hydrolase genes glgB and glgX of K. pneumoniae. We found that both enzymes exhibited significant degradation activity against glycogen substrates and were capable of degrading amylopectin, amylose, and pullulan. The optimal temperatures for GlgB and GlgX were both in the range of 35-40°C, with optimal pH values of 7.5 and 7.0, respectively, and they exhibited high stability at 37°C. Subsequently, we deleted the glgB and glgX genes in K. pneumoniae. The deletion of the glgB gene resulted in a decrease in the growth rate of the bacteria and defected glycogen synthesis. In contrast, the deletion of the glgX gene slightly accelerated the growth rate and led to continuous glycogen accumulation. In terms of biofilm formation and virulence, defects in glycogen synthesis impeded biofilm formation and virulence, while continuous glycogen accumulation did not affect biofilm formation but slightly increased virulence. In conclusion, the glgB and glgX genes are essential for the glycogen synthesis and metabolism in K. pneumoniae and further influence the biofilm formation capacity and virulence.

Changes in agrochemical properties of meadow chernozem-like soil under prolonged exposure to agrogenic factors in grain-soybean crop rotation

In a long-term stationary experiment to study the fertilizer system in crop rotation, established in 1962–1964 on meadow chernozem-like soil in the southern natural and climatic zone of the Amur region, the influence of prolonged use of mineral and organo-mineral fertilizer systems on the agrochemical properties of meadow chernozem-like soil in relation to the level of crop yield in crop rotation was studied. The use of mineral fertilizers alone and together with organic ones provided an increase in the content of mobile phosphorus in the soil by 2.0–2.5 times, its mobility by 2.9–3.5 times relative to control. The long-term use of the organo-mineral fertilizer system led to an increase in the humus content by 0.69% and the preservation of acidity indicators at the initial level, while the application of only mineral fertilizers increased the hydrolytic and metabolic acidity. Wheat yield when applying N30 against the background of prolonged application of fertilizers to the 12th rotation of the crop rotation increased by 0.58 t/ha relative to the control, with its aftereffect – by 0.30 t/ha. At the same time, the yield of soybeans was 2.42–2.62 t/ha. It was found that the productivity of crop rotation was determined by 73% by changes in humus content, soil acid content and mobile P2O5 content in the 0–20 cm soil layer. The relationship of crop rotation productivity with humus content was weak (β = 0.26), hydrolytic acidity – medium reverse (β = –0.57), metabolic acidity – strong reverse (β = –0.81) and phosphorus content – strong (β = 0.84). The values of p-levels and Student coefficients indicated the fact that hydrolytic and metabolic acidity, the content of mobile phosphorus were statistically significant variables.

Factores de riesgo para la aparición de úlceras por presión (UPP) en pacientes hospitalizados en unidades de terapia intensiva: revisión sistemática

Pressure ulcers are lesions that occur on the skin or underlying tissue, typically over a bone or prominence. They vary in size and severity depending on the affected tissue layer, beginning with erythema that may extend to the underlying bone. Patients admitted to intensive care units (ICUs) are particularly susceptible to developing pressure ulcers (PUs), resulting in the highest incidence and prevalence rates. The objective of this study is to identify risk factors associated with the development of pressure ulcers (PUs) in patients admitted to the Intensive Care Unit. The study adheres to conventional academic structure and employs clear, objective language with precise word choice. The text is grammatically correct and free from errors. To achieve this, a systematic review of the literature was conducted using the databases PubMed - Medline, Science Direct, Springer and Web of Science. The search included articles published between 2018 and 2023, resulting in the identification of 413 articles. After screening, 15 studies were included in the final analysis. No changes in content were made. The studies selected identified reduced mobility, nutritional deficit, and haemodynamic instability as the most common risk factors for pressure ulcers. It is important to note that pressure ulcer development is not caused by a single factor, but rather a complex interaction of multiple factors.

Changes in Photosynthetic Efficiency, Biomass, and Sugar Content of Sweet Sorghum Under Different Water and Salt Conditions in Arid Region of Northwest China

Sweet sorghum (Sorghum bicolor L. Moench) has significant cultivation potential in arid and saline–alkaline regions due to its drought and salt tolerance. This study aims to evaluate the mechanisms by which increased soil salinity and reduced irrigation affect the growth, aboveground biomass, and stem sugar content of sweet sorghum. A two-year field experiment was conducted, with four salinity levels (CK: 4.17 dS/m, S1: 5.83 dS/m, S2: 7.50 dS/m, and S3: 9.17 dS/m) and three irrigation levels (W1: 90 mm, W2: 70 mm, and W3: 50 mm). The results showed that increased salinity and reduced irrigation significantly reduced both the emergence rate and aboveground biomass, with the decreases in the emergence rate ranging from 11.0% to 36.2% and the reductions in the aboveground biomass ranging from 15.9% to 43.8%. Additionally, increased soil salinity led to reductions in stem sugar content of 6.3% (S1), 8.8% (S2), and 12.8% (S3), respectively. The results also indicated that photosynthetic efficiency, including the net photosynthetic rate (Pn), stomatal conductance (Gs), and chlorophyll content (SPAD), was significantly hindered under increased water and salt stress, with the Pn decreasing by up to 50.4% and the SPAD values decreasing by up to 36.3% under the highest stress conditions. These findings underscore the adverse impacts of increased soil salinity and reduced irrigation on sweet sorghum’s growth, photosynthetic performance, and sugar accumulation, offering critical insights for optimizing its cultivation in arid and saline environments.

Development of Mathematical Model for Predicting the Cupping of Lumber

Deformations are a significant disadvantage of wood as a structural material for products made of it. Therefore, the purpose of this work was to determine the magnitude and nature of the deformations of lumber used for the manufacturing of laminated panels in construction. The main causes of the possible changes in the shape of the surfaces of laminated panels in construction are characterized. In this paper, a model has been developed for the theoretical study of shape change in lumber, which is proposed to be determined through the warping force, which causes the deformation of lumber. The engineering formulas for calculating the warping force that leads to lumber shape change were obtained. This force mainly depends on size, changes in moisture content and the location of the lumber in the cross-section of the log.

The Stress Response of Aphids to the Accumulation of Heavy Metals Along Vicia faba L. Under Cadmium Treatment

Due to the intensification of human activities, the ecosystems are being polluted by heavy metals. The pollution of heavy metals in agricultural systems has become a serious issue of global concern. This study detected the bioaccumulation of cadmium (Cd) in broad beans and aphids through continuous exposure to varying concentrations of Cd pollution (0, 3.125, 6.25, 12.5, 25, 50 mg/L) and subsequently examined its effects on aphid energy metabolism and reproductive ability. The results showed that Cd can be transmitted and accumulated between Vicia faba L. and aphids along the food chain, and the amount of accumulation was related to the Cd treatment concentration. Quantitative real-time PCR results showed that the expression levels of trehalase (TRE) and trehalose-6-phosphate synthase (TPS) in F1 were significantly upregulated, and those of vitellogenin (Vg) were varied across the five generations of aphids after Cd treatment, which were up-regulated, and others down-regulated. Compared with the control group, the glycogen content and two types of trehalase activities of the first-generation Cd-treatment aphids were decreased, while trehalose content increased; there was no significant change in the carbohydrate content and trehalase activity of the fourth and fifth generations of aphids. In addition, the reproduction of female aphids was inhibited. This research is helpful for studying the toxic effects of heavy metals on insects and the adaptation mechanisms of insects to extreme environments. It also provides a theoretical basis for further exploring the molecular mechanisms of Cd homeostasis in plants and insects under Cd stress.

Dexamethasone-loaded fibroin nanoparticles promote retinal reattachment in rats by regulating the Th17/Treg balance.

Purpose&#xD;Retinal detachment (RD) is a common acute blinding eye disease. DEX, an adrenocorticosteroid drug, has predominant protective effects on RD. However, given its poor water solubility and low bioavailability, we aimed to develop an alternative nano-based treatment approach to investigate the effects and underlying mechanisms of RD.&#xD;Methods&#xD;SF@DEX nanomaterials were synthesized and then successfully characterized. In vitro, phagocytosis was measured by flow cytometry. The expression levels of IL-17 and IL-10 were determined by ELISA. A rat model of RD was established by surgery. Then, rats were orally administered with SF, SF@DEX, and DEX, respectively. The level of IL-17A and FOXP3 was assessed by PCR, and the expression levels of TGF-β1, IL-10, IL-17A, and FOXP3 were detected by Western blot. The apoptotic level of retinal ganglion cells (RGCs) in retinal tissue was measured by TUNEL assay, and confocal microscopy was used to detect changes in the colocalization content of IL-17A and FOXP3 in retinal tissue.&#xD;Results&#xD;Our results demonstrated that the nanoparticles exhibited good stability. The encapsulation efficiency (EE) was 90%, and approximately 60% of DEX was released within 12 hours from the dialysis bag. In vivo, after treatment with SF@DEX, the expression of Th17 cells and IL-17A significantly decreased, while the expression levels of Tregs, FOXP3, TGF-β1, and IL-10 were increased. Furthermore, SF@DEX nanomaterial treatment markedly alleviated the severity of RD in rats.&#xD;Conclusion&#xD;Taken together, these findings demonstrate that SF@DEX can protect against RD and inhibit inflammation, mediated by regulating the Th17/Treg immune balance.&#xD.

Selenium Improves the Nutritional and Antioxidant Properties of Oregano (Origanum vulgare L.) Grown in Hydroponics

Oregano (Origanum vulgare L.) is one of the most commercially popular aromatic spices which has long been used in folk medicine as a medicinal plant due to the presence of a wide group of bioactive secondary metabolites. The experimental data available to date indicate that plants of individual species within the Lamiaceae family implement different strategies for the absorption and distribution of selenium (Se) and differ in their metabolic response to Se treatment. In this regard, the present study investigated the effect of Se application (in the form of sodium selenate) at various concentrations (2.0, 5.0, 10.0, 20.0, and 40.0 μM) on the growth and accumulation of Se in oregano plant shoots and roots, as well as on nutritional components and secondary metabolites in shoots. The addition of Se to the nutrient solution at concentrations of 2–20 μM did not adversely affect the growth and accumulation of biomass in the oregano plants, which were characterized by a significant ability to transfer Se from roots to shoots (the translocation factor was &gt;2). The Se treatment enhanced the nutritional proprieties of the oregano and, particularly, it stimulated the accumulation of carbohydrates and proteins (by 30 and 17%) and minerals (calcium and manganese). The total contents of phenolic compounds, flavonoids, hydroxycinnamic acids, luteolin-7-glucoside and its derivatives, catechin, 3,4-dihydroxybenzoic acid, rosmarinic acid and oleanolic and ursolic acids, as well as the percentage of essential oil, showed a dose-dependent increase in the oregano under the Se treatment. Changes in the relative content of the four main components of oregano essential oil (sabinene, germacrene D, β-caryophyllene, and (Z)-β-ocimene) under the Se treatment were not significant. The relative proportions of β-caryophyllene oxide and terpinen-4-ol increased with Se concentration augmentation in the nutrient solution. The obtained results indicate the prospect of using Se at 5–20 μM concentrations in nutrient solution in hydroponically grown oregano to produce Se-biofortified plants with higher levels of compounds beneficial to health and antioxidant activity without yield reduction.

Modification of computer-aided modelling input data based on medium-scale fire tests of wooden beams

The aim of the paper was to optimize the settings of the material properties of a computer model describing heat transfer in a wooden beam exposed to thermal loading from a porcelain radiation panel. The methodology was based on performing medium-scale fire tests as a basis for a creation of finite element model with 6 different setups of material characteristics based on the outputs of tests. When adjusting the settings, the T-history method was used to determine a beginning and end of a phase change of the water content in the wood, a thermal conductivity was adjusted based on a density and a moisture content, and enthalpy was used instead of a specific heat. The results of the simulations were compared with the real medium-scale fire tests, which showed the importance of adjusting the input data. Based on the T-history method, the setting with a thermal conductivity value of 0.35 W·m-1·K-1 at a temperature of 114.8 °C was shown to be the best, with a coefficient of determination 98.7%.The results of the simulations showed that there could be a correlation between the moisture content of the wood and the maximum value of the thermal conductivity of the wood in the phase change of water.

Physiological characteristics and transcriptomic analyses of alfalfa root crown in wintering

BackgroundAlfalfa, scientifically identified as Medicago sativa, is repeatedly referred to as the “king of forages”. Because of its tight relationship to winter hardiness, the alfalfa’s root crown plays a significant role as a storage organ over the winter. At present, it is still unknown what molecular process makes the alfalfa root crown resistant to cold. This study was aimed to study these knowledge gaps. Using RNA sequencing (RNA-Seq) technology, significant genes associated with cold hardiness were found.MethodsAccording to the random block design, Longmu 806 alfalfa and Sardi alfalfa were planted in regional experiments. Under the condition of low-temperature treatment in winter, the differentially expressed genes (DEGs), winter survival rate (WSR), and physiological characteristics were, in turn, calculated by RNA-Seq, chemical analysis, and field investigation.ResultsThe WSR of the Longmu 806 alfalfa was 3.68-fold greater than that of the Sardi alfalfa. The jasmonic acid (JA), soluble sugar (SS), proline (Pro), and glutathione (GSH) concentration in the roots of Longmu 806 alfalfa was more than the same amount in Sardi alfalfa in other words P is less than 0.05. An entire set of 878 DEGs related to winter hardiness was found by statistical analysis. Among them, 463 DEGs showed an increase in expression, whereas 415 DEGs showed a decrease in expression. The metabolic pathways’ examination presented that the DEGs (MsERF1, MsCHIB, MsJAZ, MsAOC, MsGST, MsINV, MsTPS, and MsOAT) were linked to the pathways of “plant hormone signaling transduction”, “Amino sugar and nucleotide sugar metabolism”, and “glutathione metabolism”. Furthermore, the physiological changes in JA, SS, Pro content, and GSH were influenced by the dynamic transcription profile of LT (low- temperature) resistance-related genes.

Effects of Mercury Pollution on Soil Organic Carbon Stability and Carbon-fixing Microbial Communities

To elucidate the effects of Hg pollution on soil organic carbon stability and autotrophic microbial carbon assimilation, the characteristics of soil CO2 emission rate, organic carbon components, and cbbL and cbbM functional microorganisms before and after 29 d of Hg pollution were studied using indoor culture experiments and molecular biology techniques. The results showed that the effects of different levels of Hg pollution on soil CO2 emission rates were different. High levels of Hg （S2,S3,and S5） inhibited soil CO2 cumulative emissions, whereas low levels of Hg （S1,S4,and S6） promoted soil carbon emissions. Hg pollution affected the proportion of soil organic carbon components. The changes in SOC and MBC contents in different treatments were basically the same, with significant differences （P &lt; 0.05）. EOC and DOC decreased with the increase in Hg content. Compared with that at 1 d, the qCO2 of each treatment was significantly decreased at the end of culture （P &lt; 0.05）. The effects of different levels of Hg pollution on the functional microbial communities of cbbL and cbbM were significantly different. Proteobacteria, Actinobacteria, and Acidobacteria were the dominant phyla shared by the two functional microorganisms. Cumulative soil CO2 emissions and SOC were the main factors affecting the change in the cbbL community, and soil available Hg was the main factor affecting the change in the cbbM community. In summary, the results of this study can provide a theoretical basis for the carbon cycle and accumulation of Hg-contaminated regional ecosystems.

Clinical utility of liver function tests for resolution of metabolic dysfunction-associated steatotic liver disease after weight loss in the Diabetes Remission Clinical Trial.

Ectopic fat is reduced by effective weight management, but difficult to assess clinically. We evaluated paired data on 42 participants in the intervention group of the Diabetes Remission Clinical Trial (DiRECT) at baseline, 12 and 24 months after weight loss as indicators of liver fat content measured by 3-point Dixon MRI. Baseline liver fat was elevated at 13.0 [7.8-23.3]% with fasting plasma glucose 7.9 [7.1-10.1] mmol/L. Prevalence of baseline MASLD was 86.4%. After weight loss of 11.9 ± 1.2 kg (0-37 kg) at 12 months, remission of MASLD occurred in 74% and liver fat normalised for many (1.8 [1.2-5.2]%; p < 0.0001) as did fasting glucose (5.9 [5.5-7.2] mmol/L; p < 0.0001). Alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) decreased at 12 months by 38 [19-60]% (p < 0·0001) and 38 [16-53]% (p < 0.0001) respectively. The positive predictive value for decrease in liver fat, with baseline values of >40 IU/L, was 100% for ALT and 87.5% for GGT. As expected, change in liver fat correlated with change in ALT (r = 0.64; p < 0.0001), GGT (r = 0.38; p = 0.013), AST (r = 0.36; p = 0.018), fatty liver index (r = 0.50; p < 0.0001) and hepatic steatosis index (r = 0.44; p < 0.0001). Metabolic dysfunction-associated steatotic liver disease, an important marker of ill-health is improved by intentional weight loss. If enzyme levels are raised at baseline, following weight loss, changes in ALT and GGT usefully reflect change in liver fat content, with high positive predictive value. Monitoring liver enzymes can provide a simple way to assess change in liver fat following weight loss in day-to-day clinical practice.

Effects of Rock Water with Different Alkalinity and Pre-Oxidation on Re-Ignition Characteristics of Residual Coal

ABSTRACT To investigate the impact of alkaline rock water (pH = 8, 9) combined with pre-oxidation on changes in pore structure and functional groups of residual coal in goaf, and consequently, on the secondary oxidation and spontaneous combustion characteristics of coal samples, an analysis was conducted. This analysis focused on examining changes in pore morphology and functional group content of pre-oxidized coal (OI0) and water-immersed oxidized coal (OI) through experiments utilizing low-temperature nitrogen adsorption and in-situ diffuse reflectance infrared spectroscopy. Secondary oxidation and spontaneous combustion characteristics of coal samples were analyzed using thermogravimetric differential thermal analysis incorporating oxidation kinetic theory. The findings indicated that after the combined effect of pre-oxidation and alkali leaching, the mesopore volume of the coal decreased, pore complexity increased, oxygen storage capacity was enhanced, and the apparent activation energy of the coal samples was significantly reduced. This reduction in activation energy was pronounced at lower temperatures but less so at higher temperatures. Specifically, the methyl and methylene contents of OI9 were significantly higher than those of other coal samples within the temperature range of 80–160°C. Meanwhile, the heat release of the low-temperature oxidation stages of OI0, OI8, and OI9 increased by 70.82%, 190.25%, and 75.05%, respectively, compared with RC. The study indicates an elevated risk of spontaneous coal combustion following the combined treatment of alkaline leaching and pre-oxidation. This research elucidates the mechanism of spontaneous combustion of water-immersed coal by alkaline rock water and pre-oxidation, providing valuable insights for the control of coal fires in alkaline mine-water environments.

Changes in Carotenoids and Quality Parameters of Sweet Paprika (Capsicum annuum) After an Accelerated Heat Treatment

Paprika, obtained from dried red pepper (C. annuum), is valued for its characteristic colour and flavour. Its carotenoid content, which is important for both sensory and nutritional quality, varies depending on several factors (agronomic conditions and technological treatment with special attention to the drying methods) that influence the colour and antioxidant capacity of the samples. This study investigated the effect of an accelerated thermal treatment (80 °C for 8 h) applied to evaluate the oxidative stability of the carotenoids and the colour of ground paprika depending on its origin (Peru or China). Changes in quality parameters (ASTA index and CIELAB colour), carotenoid content and profile (HPLC-DAD) and lipophilic antioxidant capacity (FRAP and ABTS•+ methods) were evaluated. Untreated Chinese samples had 30% more total carotenoids than Peruvian samples, but this was not reflected in ASTA units, indicating that at least a 50% carotenoid variation is required for significant differences. Treatment resulted in a carotenoid loss of 70% in Peruvian and 30% in Chinese samples, with changes in total carotenoids correlating positively with antioxidant capacity. Both origins had similar carotenoid profiles, with β-carotene being the predominant carotenoid, while distinct contents were observed between the origins. The higher content of esterified carotenoids in Chinese peppers resulted in better thermal stability. The results highlight the necessity for tailored production processes to maintain nutritional integrity and antioxidant capacity.

Monthly Prediction of Pine Stress Probability Caused by Pine Shoot Beetle Infestation Using Sentinel-2 Satellite Data

Due to the significant threat to forest health posed by beetle infestations on pine trees, timely and accurate predictions are crucial for effective forest management. This study developed a pine tree stress probability prediction workflow based on monthly cloud-free Sentinel-2 composite images to address this challenge. First, representative pine tree stress samples were selected by combining long-term forest disturbance data using the Continuous Change Detection and Classification (CCDC) algorithm with high-resolution remote sensing imagery. Monthly cloud-free Sentinel-2 images were then composited using the Multifactor Weighting (MFW) method. Finally, a Random Forest (RF) algorithm was employed to build the pine tree stress probability model and analyze the importance of spectral, topographic, and meteorological features. The model achieved prediction precisions of 0.876, 0.900, and 0.883, and overall accuracies of 89.5%, 91.6%, and 90.2% for January, February, and March 2023, respectively. The results indicate that spectral features, such as band reflectance and vegetation indices, ranked among the top five in importance (i.e., SWIR2, SWIR1, Red band, NDVI, and NBR). They more effectively reflected changes in canopy pigments and leaf moisture content under stress compared with topographic and meteorological features. Additionally, combining long-term stress disturbance data with high-resolution imagery to select training samples improved their spatial and temporal representativeness, enhancing the model’s predictive capability. This approach provides valuable insights for improving forest health monitoring and uncovers opportunities to predict future beetle outbreaks and take preventive measures.

Expression and functional analysis of adipokinetic hormone reveal its different roles in larval development and female fecundity in Panonychus citri (McGregor) (Acari: Tetranychidae).

Adipokinetic hormone (AKH), a crucial neuropeptide, participates in the important physiological processes by specially binding to its receptor to activate the AKH signalling pathway. AKH regulates energy metabolism. However, it remains unknown whether AKH affects larval development and adult reproduction by influencing energy metabolism. In the present study, the AKH was identified from Panonychus citri and contained the conserved functional domain 'Q-[LIV]-[NT]-F-[ST]-X (2)-W' that characterises the AKH family. The relative expression levels of PcAKH revealed different patterns of AKH expression at different developmental stages of P. citri. Feeding of double-standard RNA against PcAKH induced decreased fecundity and reduced survival, which was accompanied by the down-regulation of vitellogenin gene expression. In addition, after silencing the PcAKH, lipid metabolism and carbohydrate homeostasis were disrupted, manifested by increased body width and weight, and fasting phenomenon. Further investigation found that compared with the control, physiological changes in trehalose and triglyceride contents were accompanied by variations in the mRNA expression levels of genes related to lipid metabolism and carbohydrate metabolism. The disorder of lipid and carbohydrate metabolism may affect adult female reproduction, which may lead to insufficient vitellogenin deposition. Moreover, the silencing of PcAKH seriously affected the growth and development of larvae, which was manifested as delayed development period and difficulty in moulting. Conclusively, all these results in current study demonstrated that double-stranded RNA silencing system targeting PcAKH effectively inhibited larval development and female fecundity by disturbing lipid and carbohydrate metabolism, and PcAKH is a specific RNAi target for control of P. citri in the design and development of biopesticide in sustainable agriculture.

Physiological response of diverse maize genotypes to heat stress and simple sequence repeats markers-based genotyping in Rawalpindi, Punjab Pakistan

The current study was designed to observe the response of maize genotypes under high-temperature stress conditions and to check their diversity using simple sequence repeats (SSR) markers in in-vitro conditions. Maize genotypes (n=10) were subjected to heat stress at ~45 °C for 72 h after growing into young seedlings. Their physiological responses were determined by measuring the changes in proline content (PC), chlorophyll content (CC), cell membrane stability (CMS), relative water content (RWC) and osmotic potential (Ψπ). The analysed data disclosed significant differences (P ≤ 0.01) among all the characters. Comparison between control and heat-treated genotypes depicted a notable increase in PC, Ψπ while a decrease in CC, RWC and CMS index in heat-treated plants. Maize genotypes viz. NCEV-1230, NARC-4, HN Gold and OPV-20 performed better under heat stress and also showed a strong genetic relationship for similarity index in dendrogram based on selected SSR markers related to abiotic stress tolerance. This study is beneficial for understanding the physiological behaviour of maize plants under heat stress and for further genetic studies on maize to select heat-tolerant lines for breeding programs