A Method for Extracting High-Resolution Building Height Information in Rural Areas Using GF-7 Data.

Building height is important information in disaster management and damage assessment. It is also a key parameter in studies such as population modeling and urbanization. Relatively few studies have been conducted on extracting building height in rural areas using imagery from China's Gaofen-7 satellite (GF-7). In this study, we developed a method combining photogrammetry and deep learning to extract building height using GF-7 data in the rural area of Pingquan in northern China. The deep learning model DELaMa was proposed for digital surface model (DSM) editing based on the Large Mask Inpainting (LaMa) architecture. It not only preserves topographic details but also reasonably predicts the topography inside the building mask. The percentile value of the normalized digital surface model (nDSM) in the building footprint was taken as the building height. The extracted building heights in the study area are highly consistent with the reference building heights measured from the ICESat-2 LiDAR point cloud, with an R2 of 0.83, an MAE of 1.81 m and an RMSE of 2.13 m for all validation buildings. Overall, the proposed method in this paper helps to promote the use of satellite data in large-scale building height surveys, especially in rural areas.

Thermal Treatment Effects on Structure and Mechanical Properties of Polybutylene Terephthalate and Epoxy Resin Composites Reinforced with Glass Fiber.

In this study, two types of composites, polybutylene terephthalate (PBT) and epoxy resin (ER), reinforced with 20% of glass fiber (GF) are used as the comparative research objects. Their mechanical properties after thermal aging at 85~145 °C are evaluated by tensile strength and fracture morphology analysis. The results show that the composites have similar aging laws. The tensile strength of GF/PBT and GF/ER decrease gradually with the increase of aging temperature, while their elastic moduli are independent of the thermal treatment temperature. Scanning electron microscopy study of the fracture surface shows that separation of glass fiber from PBT and ER matrix becomes more obvious at higher aging temperature. The fibers on the matrix surface appear clear and smooth, and the whole pulled out GFs can be observed. As a main mechanical strength degradation mechanism, the deterioration of interface adhesion between the matrix and GF is discussed. A large difference in coefficients of thermal expansion of the matrix and GF is a main factor of the mechanical degradation.

Sulfur fractionation using high-resolution continuum source molecular absorption spectrometry with calcium and hydrophobic palladium nanoparticles as chemical modifiers.

The unprecedented use of high-resolution continuum source molecular absorption spectrometry (HR-CS MAS) for the fractionation of organic and inorganic sulfur (S) species through monitoring the CS molecule is presented here. Two separate methods for determining organic (CSorg) and inorganic (CSino) sulfur were developed to work sequentially. The optimized temperature program for both methodologies has two pyrolysis steps and one vaporization step (1st Tpyr: 1800 and 2ndTpyr: 800 °C, and Tvap: 2500 °C). The fractionation was achieved by implementing hydrophobic Pd NPs and Ca as chemical modifiers for the CSorg and CSino methods. Method development was performed by applying different statistical models, allowing the definition of optimal conditions for the chemical modifier mass, and minimizing the S species interconversion, i.e., Doehlert design, and central composite design. The limits of detection (LoD) for CSorg and CSino were 2.4 and 2.1 mg L-1, respectively. Recovery tests evaluated the method's specificity and accuracy; over 92 % recovery was found for both CSorg and CSino. Thus, the proposed methods offer a reliable alternative for fractionating organic and inorganic S by using HR-CS MAS.

Comparative Proteomic Analysis Provides New Insights into Improved Grain-filling in Ratoon Season Rice.

Grain-filling of rice spikelets (particularly for the later flowering inferior spikelets) is an important characteristic that affects both quality and yield. Rice ratooning technology is used to cultivate a second crop from dormant buds that sprout from stubble left after the first harvest. This study used two rice varieties, the conventional indica rice 'Jinhui 809' and the hybrid indica-japonica rice 'Yongyou 1540', to assess the impact of rice ratooning on grain-filling. The results indicated that the grain-filling process in inferior spikelets of ratoon season rice (ISR) showed significant improvement compared to inferior spikelets of main crop (late season) rice (ISL). This improvement was evident in the earlier onset of rapid grain-filling, higher seed-setting percentage, and improved grain quality. A label-free quantitative proteomic analysis using mass spectrometry identified 1724 proteins with significant abundance changes, shedding light on the molecular mechanisms behind the improved grain-filling in ISR. The functional analysis of these proteins indicated that ratooning stimulated the metabolic processes of sucrose-starch, trehalose, and hormones in rice inferior spikelets, leading to enhanced enzyme activities related to starch synthesis, elevated concentrations of trehalose-6-phosphate (T6P), indole-3-acetic acid (IAA) and zeatin riboside (ZR) during the active grain-filling phase. This research highlighted the importance of the GF14f protein as a key regulator in the grain-filling process of ISR. It revealed that GF14f transcriptional and protein levels declined more rapidly in ISR compared to ISL during grain-filling. Additionally, the GF14f-RNAi plants specific to the endosperm exhibited improved quality in inferior spikelets. These findings suggest that the enhancement of starch synthesis, increased levels of IAA, ZR, and T6P, along with the rapid decrease in GF14f protein, play a role in enhancing grain-filling in ratoon season rice.

Optimizing the Tensile Strength of Weld Lines in Glass Fiber Composite Injection Molding.

Weld line defects, commonly occurring during the plastic product manufacturing process, are caused by the merging of two opposing streams of molten plastic. The presence of weld lines harms the product's aesthetic appeal and durability. This study uses artificial neural networks to forecast the ultimate tensile strength of a PA6 composite incorporating 30% glass fibers (GFs). Data were collected from tensile strength tests and the technical parameters of injection molding. The packing pressure factor is the one that significantly affects the tensile strength value. The melt temperature has a significant impact on the product's strength as well. In contrast, the filling time factor has less impact than other factors. According to the scanning electron microscope result, the smooth fracture surface indicates the weld line area's high brittleness. Fiber bridging across the weld line area is evident in numerous fractured GF pieces on the fracture surface, which enhances this area. Tensile strength values vary based on the injection parameters, from 65.51 MPa to 73.19 MPa. In addition, the experimental data comprise the outcomes of the artificial neural networks (ANNs), with the maximum relative variation being only 4.63%. The results could improve the PA6 reinforced with 30% GF injection molding procedure with weld lines. In further research, mold temperature improvement should be considered an exemplary method for enhancing the weld line strength.

Hepatocyte Growth Factor Has Unique Functions in Keratinocytes that Differ from those of IL-17A and TNF and May Contribute to Inflammatory Pathways in Hidradenitis Suppurativa.

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that is difficult to control, and its mechanism remains unclear. Hepatocyte GF (HGF) has been reported to be significantly upregulated in the serum and skin of patients with HS, especially in the lesions with tunnels. In this study, we examined the transcriptome of HGF-treated keratinocytes and compared it with genetic profiling of HS lesions. HGF was highly expressed in HS skin, especially in the deep dermis, compared with that in healthy controls, and its source was mainly fibroblasts. HGF upregulated more genes in keratinocytes than IL-17A or TNF-a, and these genes included multiple epithelial-mesenchymal transition-related genes. Differentially expressed genes in HGF-stimulated keratinocytes were involved in activation of epithelial-mesenchymal transition-related pathways. These HGF-induced genes were significantly upregulated in HS lesions compared with those in healthy skin and nonlesions and were more strongly associated with HS tunnels. In summary, HGF was highly expressed in HS and induced epithelial-mesenchymal transition-related genes in keratinocytes; HGF-induced genes were highly associated with gene profiling of HS with tunnels, suggesting that HGF may be involved in HS tunnel formation through epithelial-mesenchymal transition.

Novel griseofulvin zinc nanohybrid emulsion for intensifying the antimicrobial control of dermatophytes and some opportunistic pathogens.

Dermatophytosis is a critical sort of skin infection caused by dermatophytes. The long-term treatment of such skin infections may be improved through the application of nanotechnology. This study aimed to prepare griseofulvin zinc Nanohybrid emulsion (GF-Zn-NHE) to improve griseofulvin activity against dermatophytes and some opportunistic pathogenic yeasts and bacteria. The GF-Zn-NHE is prepared by ultra-homogenization ultra-sonication strategies and validated by UV-visible spectroscopy analysis that confirms presences of griseofulvin and Zn-NPs peaks at 265 and 360 nm, respectively. The GF-Zn-NHE has mean distribution size 50 nm and zeta potential in the range from -40 to -36 mV with no significant changes in size distribution and particle size within 120 day ageing. Fourier transform infrared spectroscopy spectrum confirmed the presence of griseofulvin and Zn-NPs stretching vibration peaks. Gamma ray has a negative influence on GF-Zn-NE production and stability. GF-Zn-NHE drug release 95% up to 24 h and 98% up to 72 h of GF was observed and Zinc 90% up to 24 h and 95% up to 72 h, respectively. High antimicrobial activity was observed with GF-Zn-NHE against dermatophytic pathogens in compare with GF, GF-NE, zinc nitrate and ketoconazole with inhibition zone ranged from 14 to 36 mm. The results have shown that the MIC value for Cryptococcus neoformans, Prophyromonas gingivalis and Pseudomonas aeruginosa is 0.125 mg ml -1 and for Trichophyton rubrum, L. bulgaricus and Escherichia coli value is 0.25 mg ml -1 and for Candida albicans, Malassezia furfur and Enterococcus faecalis is 0.5 mg ml -1 and finally 1 mg ml -1 for Streptococcus mutans. TEM of treated Cryptococcus neoformans cells with GF-Zn-NHE displayed essentially modified morphology, degradation, damage of organelles, vacuoles and other structures.

[Application of LA-UNet network model in remote sensing classification of urban green space]. / LA-UNet网络模型在城市绿地遥感分类中的应用.

The accurate identification and monitoring of urban green space is of great significance in urban planning and ecological management. In view of the complex background of urban green space, the traditional remote sensing classification technology is prone to the problem of misalignment and adhesion. Taking Yuhua District of Changsha City as the research area and Gaofen-2 (GF-2) remote sensing image as the data source, we proposed a remote sensing classification method for urban green space based on the LA-UNet model, which was based on the UNet model. We introduced the DWTCA channel attention mechanism module to improve the attention of the network to green space information, and used the CARAFE module to up sample the extracted features to achieve accurate classification of trees, shrubs and other land types in the complex background of the city. The results showed that the LA-UNet model had the best classification effect of urban green space when using standard false color remote sensing images. The overall accuracy and mean intersection over union were 96.3% and 90.9%, which were 2.8% and 6.1% higher than the UNet model, respectively. In the Potsdam public dataset, the overall accuracy and mean intersection over union of the LA-UNet model were also better than those of the UNet model, which increased by 0.9% and 1.8%, respectively, indicating that the LA-UNet model had good robustness and versatility. In summary, the proposed LA-UNet model could effectively alleviate the problems of misalignment and adhesion of urban green space, with advantages in the remote sensing classification of urban green space. The improved LA-UNet model had a smaller parameter volume than the UNet model, which could effectively improve the classification accuracy of urban green space. This study would provide a methodological reference for the accurate classification and understanding the spatial distribution of urban green space.

Mechanical, Flame-Retardant and Dielectric Properties of Intumescent Flame Retardant/Glass Fiber-Reinforced Polypropylene through a Novel Dispersed Distribution Mode.

The application of continuous glass fiber-reinforced polypropylene thermoplastic composites (GF/PP) is limited due to the inadequate flame retardancy of the polypropylene (PP) matrix. Apart from altering the composition of the flame retardants, the distribution modes of flame retardants also impact material performance. In this study, an alternative approach involving non-uniform distribution is proposed, namely, dispersed distribution, in which non-flame-retardant-content layers (NFRLs) and/or low-flame-retardant-content layers (LFRLs) are dispersed among high-flame-retardant-content layers (HFRLs). The mechanical, flame retardant and dielectric properties of GF/PP with intumescent flame retardant (IFR/GF/PP) are investigated comparatively under uniform, gradient, and dispersed distributions of the flame retardants. The results demonstrate that non-uniform distribution exhibits superior flame retardant performance compared to uniform distribution. Dispersed distribution enables IFR/GF/PP to attain enhanced mechanical properties and reduced dielectric constants while maintaining excellent flame-retardant properties.

Application of sourdough in gluten-free bakery products.

ABSTRACTSIn recent years, the demand for gluten-free (GF) bakery products has grown rapidly due to the remarkable rising number of celiac patients and the increasing health awareness of GF products. However, GF products generally suffer from defects such as poor sensorial level, low nutritional value, high prices and short shelf life. Sourdough is the important starter culture applied in bakery field, and it has been proven to be ideal for enhancing the overall quality of bakery products. This review aims to systematically reviewed the application of sourdough in GF bakery products and its improvement to GF bakery products in terms of texture, shelf life, nutrition and flavor. Its positive effects derive from the complex metabolic activities of sourdough microorganisms, such as acidification, proteolysis, production of exopolysaccharides (EPS), activation of endogenous enzymes, and production of antibacterial substances. Finally, researchers are encouraged to expand the use of sourdough in GF bakery products to increase the variety of GF products. And the technical and nutritional potential of sourdough should be developed more widely.

Genomic mining of Geobacillus stearothermophilus GF16 for xylose production from hemicellulose-rich biomasses using secreted enzymes.

The valorization of lignocellulosic biomass, derived from various bio-waste materials, has received considerable attention as a sustainable approach to improve production chains while reducing environmental impact. Microbial enzymes have emerged as key players in the degradation of polysaccharides, offering versatile applications in biotechnology and industry. Among these enzymes, glycoside hydrolases (GHs) play a central role. Xylanases, in particular, are used in a wide range of applications and are essential for the production of xylose, which can be fermented into bioethanol or find use in many other industries. Currently, fungal secretomes dominate as the main reservoir of lignocellulolytic enzymes, but thermophilic microorganisms offer notable advantages in terms of enzyme stability and production efficiency. Here we present the genomic characterization of Geobacillus stearothermophilus GF16 to identify genes encoding putative enzymes involved in lignocellulose degradation. Thermostable GHs secreted by G. stearothermophilus GF16 were investigated and found to be active on different natural polysaccharides and synthetic substrates, revealing an array of inducible GH activities. In particular, the concentrated secretome possesses significant thermostable xylanase and ß-xylosidase activities (5 ×103 U/L and 1.7 ×105 U/L, respectively), highlighting its potential for application in biomass valorization. We assessed the hemicellulose hydrolysis capabilities of various agri-food wastes using the concentrated secretome of the strain cultivated on xylan. An impressive 300-fold increase in xylose release compared to a commercially available cocktail was obtained with the secretome, underscoring the remarkable efficacy of this approach.

In Vitro Evaluation of Bioavailability of Cr from Daily Food Rations and Dietary Supplements from the Polish Market.

Only some of the nutrients consumed with food are able to be absorbed from the gastrointestinal (GI) tract and enter the systemic circulation (blood). Because some elements are essential minerals for humans, their beneficial effect on the body depends significantly on their bioavailable amount (the fraction that can be absorbed and used by the organism). The term bioavailability, which is very often used to describe the part of nutrients that is able to be absorbed, is influenced by various factors of exogenous and endogenous origin. The main purpose of the study was to assess the relative bioavailability of Cr from selected dietary supplements in the presence of various types of diets, which significantly influence the level of bioavailability. The research was performed using a previously developed and optimized two-stage in vitro digestion model using cellulose dialysis tubes of food rations with the addition of pharmaceutical products. Cr was determined using the ICP-OES and GF-AAS methods, depending on its concentration in particular fractions. The determined relative bioavailability ranged between 2.97 and 3.70%. The results of the study revealed that the type of diet, the chemical form of the molecule, and the pharmaceutical form of preparations have a significant influence on the bioavailability of Cr.

Three once-weekly intra-articular injections of Hylan G-F 20 significantly improve pain relief compared with placebo in patients with chronic idiopathic knee osteoarthritis: a single-centre, evaluator-blinded and patient-blinded, randomized controlled trial.

Background: Clinical trials on the use of viscosupplementation with hyaluronic acid (HA) in patients with knee osteoarthritis (KOA) are inconsistent, making it challenging to determine its value in clinical practice. One issue is the availability of various HA products on the market; differences in their chemical features can impact patient outcomes. Herein, we assess the efficacy and safety of three once-weekly intra-articular (IA) injections of Hylan G-F 20, a high-molecular-weight and highly crosslinked HA product, in patients with KOA. We hypothesized that Hylan G-F 20 would provide significant pain relief with no increased safety risk compared with IA saline (placebo). Methods: This was a 26-week, patient-blinded and evaluator-blinded, single-centre, randomized placebo- controlled trial. Men or women ≥18 years of age with Larsen grade II or III KOA were included. Patients received IA injections of either Hylan G-F 20 or placebo once a week for 3 weeks. The primary endpoints were the week 12 and 26 visits. Primary efficacy outcomes included visual analogue scale (VAS) pain scores, patient activity level and an overall assessment of clinical condition. Secondary outcomes included adverse events (AEs) that emerged during treatment. The primary analysis included the intention-to-treat population. An alpha level of 0.05 was used in the statistical analysis. Results: Thirty patients were included in the intention-to-treat population (15 per group). All efficacy outcomes were statistically significant in favour of Hylan G-F 20, except night pain and inactivity stiffness, for both patient- assessed (all p=0.0001 at week 12) and evaluator-assessed (all p=0.0001 at week 12 and p=0.0004-0.0180 at week 26) measurements. There was also a greater proportion of symptom-free patients and those with a >50% improvement in their VAS scores, except night pain, in the Hylan G-F 20 group (p=0.001-0.003 in patient-assessed scores and p<0.0001 to 0.002 in evaluator-assessed scores at week 12). Two patients, one in each group, experienced an AE; no sequelae occurred, and no special treatment was required for either AE. No patients withdrew from the study prematurely due to an AE. Conclusion: In patients with chronic idiopathic KOA, Hylan G-F 20 provides significant improvements in pain relief compared with placebo with no added safety concerns.

MoS2-mediated active hydrogen modulation to boost Fe2+ regeneration in solar-driven electro-Fenton process.

The sluggish kinetics of Fe2+ regeneration seriously hinders the performance of Fenton process. However, the conventional Fenton system excessively stifle hydrogen-producing reactions, ignoring the significance of active hydrogen (H*) in Fe3+ reduction. Herein, a strategy of H* modulation is developed by decorating molybdenum disulfide (MoS2) on a graphite felt (GF) cathode to boost Fe2+ regeneration in solar-driven electro-Fenton (SEF) process. With MoS2 regulation, moderately dispersed MoS2 on GF can serve as a bifunctional cathode, where the H* and hydrogen peroxide (H2O2) are simultaneously generated through H+ reduction and O2 reduction, respectively. The in-situ generated H2O2 can trigger Fenton reactions with Fe2+, while the H* with robust reducing potential can significantly expedite Fe3+ reduction, consequently enhancing the HO• production. Both DFT calculations and EPR experiments confirm that H* can be activated via MoS2 decoration. The results show that Fe2+ concentration in the MoS2 @GF-SEF system remains at 15.74 mg/L (56.21%) after 6 h, which is 17.89 times that of the GF-SEF system. Moreover, the HO• content and organics degradation rate in the MoS2 @GF-SEF are 3.61 and 5.30 times those of the GF-SEF, respectively. This study provides a practical cathode strategy of H* modulation to enhance HO• production and electro-Fenton process. ENVIRONMENTAL IMPLICATION: Boosting Fe2+ regeneration is of great value for the Electro-Fenton process. Herein, report a strategy to achieve this goal based on a MoS2 @GF cathode. Remarkably, the MoS2 @GF system exhibits exceptional efficiency for both various refractory organic compounds with environmentally hazardous effects and sterilization aspects, which can also work over a wide range of pH values (3-11). Specially, this system is driven only by solar energy. These characteristics make the electro-Fenton system more suitable for practical wastewater treatment.

Enhancement of the Inner Foveal Response of Young Adults with Extended-Depth-of-Focus Contact Lens for Myopia Management.

BACKGROUND: Myopia management contact lenses have been shown to successfully decrease the rate of eye elongation in children by changing the peripheral refractive profile of the retina. Despite the efforts of the scientific community, the retinal response mechanism to defocus is still unknown. The purpose of this study was to evaluate the local electrophysiological response of the retina with a myopia control contact lens (CL) compared to a single-vision CL of the same material. METHODS: The retinal electrical activity and peripheral refraction of 16 eyes (16 subjects, 27.5 ± 5.7 years, 13 females and 3 males) with myopia between -0.75 D and -6.00 D (astigmatism < 1.00 D) were assessed with two CLs (Filcon 5B): a single-vision (SV) CL and an extended-depth-of-focus (EDOF) CL used for myopia management. The peripheral refraction was assessed with an open-field WAM-5500 auto-refractometer/keratometer in four meridians separated by 45° at 2.50 m distance. The global-flash multifocal electroretinogram (gf-mfERG) was recorded with the Reti-port/scan21 (Roland Consult) using a stimulus of 61 hexagons. The implicit time (in milliseconds) and response density (RD, in nV/deg2) of the direct (DC) and induced (IC) components were used for comparison between lenses in physiological pupil conditions. RESULTS: Although the EDOF decreased both the HCVA and the LCVA (one and two lines, respectively; p < 0.003), it still allowed a good VA. The EDOF lens induced a myopic shift in most retinal areas, with a higher and statistically significant effect on the nasal retina. No differences in the implicit times of the DC and IC components were observed between SV and EDOF. Compared with the SV, the EDOF lens showed a higher RD in the IC component in the foveal region (p = 0.032). In the remaining retinal areas, the EDOF evoked lower, non-statistically significant RD in both the DC and IC components. CONCLUSIONS: The EDOF myopia control CL enhanced the response of the inner layers of the fovea. This might suggest that, besides other mechanisms potentially involved, the central foveal retinal activity might be involved in the mechanism of myopia control with these lenses.

The effect of oral butyrate on colonic short-chain fatty acid transporters and receptors depends on microbial status.

Butyrate, a metabolite produced by gut bacteria, has demonstrated beneficial effects in the colon and has been used to treat inflammatory bowel diseases. However, the mechanism by which butyrate operates remains incompletely understood. Given that oral butyrate can exert either a direct impact on the gut mucosa or an indirect influence through its interaction with the gut microbiome, this study aimed to investigate three key aspects: (1) whether oral intake of butyrate modulates the expression of genes encoding short-chain fatty acid (SCFA) transporters (Slc16a1, Slc16a3, Slc16a4, Slc5a8, Abcg2) and receptors (Hcar2, Ffar2, Ffar3, Olfr78, Olfr558) in the colon, (2) the potential involvement of gut microbiota in this modulation, and (3) the impact of oral butyrate on the expression of colonic SCFA transporters and receptors during colonic inflammation. Specific pathogen-free (SPF) and germ-free (GF) mice with or without DSS-induced inflammation were provided with either water or a 0.5% sodium butyrate solution. The findings revealed that butyrate decreased the expression of Slc16a1, Slc5a8, and Hcar2 in SPF but not in GF mice, while it increased the expression of Slc16a3 in GF and the efflux pump Abcg2 in both GF and SPF animals. Moreover, the presence of microbiota was associated with the upregulation of Hcar2, Ffar2, and Ffar3 expression and the downregulation of Slc16a3. Interestingly, the challenge with DSS did not alter the expression of SCFA transporters, regardless of the presence or absence of microbiota, and the effect of butyrate on the transporter expression in SPF mice remained unaffected by DSS. The expression of SCFA receptors was only partially affected by DSS. Our results indicate that (1) consuming a relatively low concentration of butyrate can influence the expression of colonic SCFA transporters and receptors, with their expression being modulated by the gut microbiota, (2) the effect of butyrate does not appear to result from direct substrate-induced regulation but rather reflects an indirect effect associated with the gut microbiome, and (3) acute colon inflammation does not lead to significant changes in the transcriptional regulation of most SCFA transporters and receptors, with the effect of butyrate in the inflamed colon remaining intact.

UAV and Satellite Synergies for Mapping Grassland Aboveground Biomass in Hulunbuir Meadow Steppe.

Aboveground biomass (AGB) is an important indicator of the grassland ecosystem. It can be used to evaluate the grassland productivity and carbon stock. Satellite remote sensing technology is useful for monitoring the dynamic changes in AGB across a wide range of grasslands. However, due to the scale mismatch between satellite observations and ground surveys, significant uncertainties and biases exist in mapping grassland AGB from satellite data. This is also a common problem in low- and medium-resolution satellite remote sensing modeling that has not been effectively solved. The rapid development of uncrewed aerial vehicle (UAV) technology offers a way to solve this problem. In this study, we developed a method with UAV and satellite synergies for estimating grassland AGB that filled the gap between satellite observation and ground surveys and successfully mapped the grassland AGB in the Hulunbuir meadow steppe in the northeast of Inner Mongolia, China. First, based on the UAV hyperspectral data and ground survey data, the UAV-based AGB was estimated using a combination of typical vegetation indices (VIs) and the leaf area index (LAI), a structural parameter. Then, the UAV-based AGB was aggregated as a satellite-scale sample set and used to model satellite-based AGB estimation. At the same time, spatial information was incorporated into the LAI inversion process to minimize the scale bias between UAV and satellite data. Finally, the grassland AGB of the entire experimental area was mapped and analyzed. The results show the following: (1) random forest (RF) had the best performance compared with simple regression (SR), partial least squares regression (PLSR) and back-propagation neural network (BPNN) for UAV-based AGB estimation, with an R2 of 0.80 and an RMSE of 76.03 g/m2. (2) Grassland AGB estimation through introducing LAI achieved higher accuracy. For UAV-based AGB estimation, the R2 was improved by an average of 10% and the RMSE was reduced by an average of 9%. For satellite-based AGB estimation, the R2 was increased from 0.70 to 0.75 and the RMSE was decreased from 78.24 g/m2 to 72.36 g/m2. (3) Based on sample aggregated UAV-based AGB and an LAI map, the accuracy of satellite-based AGB estimation was significantly improved. The R2 was increased from 0.57 to 0.75, and the RMSE was decreased from 99.38 g/m2 to 72.36 g/m2. This suggests that UAVs can bridge the gap between satellite observations and field measurements by providing a sufficient training dataset for model development and AGB estimation from satellite data.

A new method based on extraction induced by emulsion breaking for determination of Co and Ni in chocolate bars by graphite furnace atomic absorption spectrometry.

This paper describes a new experimental configuration of extraction induced by emulsion breaking method to extract and determine Ni and Co in chocolate bars by graphite furnace atomic absorption spectrometry. At optimized conditions, the sample (0.08 g) was mixed with 4 mL of extractant solution (4% m/v Triton X-100 and 10% v/v HNO3) in a plastic syringe to form a solid-oil-water emulsion. Then, emulsion breaking was assisted by membrane filtration. The total extraction procedure took approximately 1 min, in opposition to 25 (centrifugation) and 50 min (heating). Extraction yields ranged from 94.8 to 114.3% for Co and from 85.9 to 108.4% for Ni. The limits of detection and quantification were, respectively, 24.73 and 82.45 µg Kg-1 for Co and 49.05 and 163.5 µg Kg-1 for Ni. Recoveries ranged from 92.1 (Ni) to 105.4% (Co).

Determination of chromium in foodstuffs by using novel adsorbent in vortex assisted-dispersive solid phase micro-extraction method: An application of multivariate techniques.

A new graft copolymer composed of polystyrene and polylinoleic acid (PLinas) with the sodium salt of iminodiacetate (Ida) was synthesized and used as an adsorbent. The vortex-assisted dispersive solid-phase micro-extraction (VA-dSPµE) method was used for the extraction and pre-concentration of chromium. Multivariate methodologies, such as factorial design and 3D surface plots, were applied for screening and optimizing effective extraction parameters. The influence of diverse analytical parameters, such as pH, sample volume, and interfering ions, on the extraction of chromium was studied. The calibration standard curve exhibited a linear range from 0.01 to 0.50 µg L-1. The relative standard deviation and limit of detection were found to be 1.65 % and 0.003 µg L-1, respectively. Extraction recoveries were found in the range of 96 to 99 % by using certified reference materials (CRMs). The adsorbent capacity of PLinas-Ida was found to be 112 mg g-1. The VA-dSPµE method demonstrated its effectiveness in the pre-concentration and determination of chromium within samples of foodstuffs by graphite furnace-atomic absorption spectrometry (GF-AAS).

Characteristics of pine wood nematode disease in Nankang District, Ganzhou, Jiangxi Province, China.

Pine wood nematode (PWN) disease is one of the major disasters in forests of southern China, causing substantial forest resources and ecological and economic losses. Based on field surveys and WFV image data from the GF-1 satellite, we constructed a spatial identification model of PWN disease with the random forest model to explore the relative influences of topography, human activities and stand factors on the occurrence of diseases and predict their spatial distribution. We then used the spatial autocorrelation analysis to assess the distribution characteristics of PWN disease at the regional scale. The results showed that the random forest model constructed in this study was effective in identifying pine nematode diseases (AUC value=0.99, overall accuracy=0.96). The norma-lized difference greenness index (NDGI), the distance to the highway, and normalized vegetation index (NDVI) were important factors in explaining the spatial variations of PWN disease occurrence. There was a positive spatial correlation in the occurrence of PWN disease (not randomly distributed but with obvious spatial aggregation characteristics). The high occurrence areas of pine wood nematode disease concentrated in Chitu Township, Zhufang Township and Shibatang Township, low occurrence areas concentrated in the vicinity of Rongjiang Street. The areas far away from the highway, low in elevation, and close to county roads were suffered to PWN disease. The results could serve the regional monitoring of pine nematode disease occurrence and provide practical guidance for PWN disease management.