Crop Mapping Based on Sentinel-2 Images Using Semantic Segmentation Model of Attention Mechanism.

Using remote sensing images to identify crop plots and estimate crop planting area is an important part of agricultural remote sensing monitoring. High-resolution remote sensing images can provide rich information regarding texture, tone, shape, and spectrum of ground objects. With the advancement of sensor and information technologies, it is now possible to categorize crops with pinpoint accuracy. This study defines crop mapping as a semantic segmentation problem; therefore, a deep learning method is proposed to identify the distribution of corn and soybean using the differences in the spatial and spectral features of crops. The study area is located in the southwest of the Great Lakes in the United States, where corn and soybean cultivation is concentrated. The proposed attention mechanism deep learning model, A2SegNet, was trained and evaluated using three years of Sentinel-2 data, collected between 2019 and 2021. The experimental results show that this method is able to fully extract the spatial and spectral characteristics of crops, and its classification effect is significantly better than that of the baseline method, and it has better classification performance than other deep learning models. We cross verified the trained model on the test sets of different years through transfer learning in both spatiotemporal and spatial dimensions. Proving the effectiveness of the attention mechanism in the process of knowledge transfer, A2SegNet showed better adaptability.

Land Cover Classification of UAV Remote Sensing Based on Transformer-CNN Hybrid Architecture.

High-precision land cover maps of remote sensing images based on an intelligent extraction method are an important research field for many scholars. In recent years, deep learning represented by convolutional neural networks has been introduced into the field of land cover remote sensing mapping. In view of the problem that a convolution operation is good at extracting local features but has limitations in modeling long-distance dependence relationships, a semantic segmentation network, DE-UNet, with a dual encoder is proposed in this paper. The Swin Transformer and convolutional neural network are used to design the hybrid architecture. The Swin Transformer pays attention to multi-scale global features and learns local features through the convolutional neural network. Integrated features take into account both global and local context information. In the experiment, remote sensing images from UAVs were used to test three deep learning models including DE-UNet. DE-UNet achieved the highest classification accuracy, and the average overall accuracy was 0.28% and 4.81% higher than UNet and UNet++, respectively. It shows that the introduction of a Transformer enhances the model fitting ability.

Transformation of Corn Stover into Furan Aldehydes by One-Pot Reaction with Acidic Lithium Bromide Solution.

Currently, the production of furan aldehydes from raw biomass suffers from low furfural yield and high energy consumption. In this study, a recyclable and practical method was explored for the preparation of furfural from corn stover by the one-pot reaction by acidic lithium bromide solution (ALBS) without pretreatment and enzymolysis. In the ALBS reaction, the furan aldehydes were generated by the degradation of lignocellulose; however, the products were unstable and were further dehydrated to form humins. So, dehydration reaction was inhibited in this study, and the high yield of furan aldehydes was obtained, in which 2.94 g/L of furfural and 2.78 g/L of 5-hydroxymethyl furfural (5-HMF) were generated with high solid loading (10 wt%), the presence of commercial catalyst ZSM-5 and co-solvent tetrahydrofuran (THF) at 140 °C for 200 min. Via this method, almost 100% of hemicellulose was transformed to furfural, and 40.71% of cellulose was transformed to 5-HMF, which was based on the theoretical yield of HMF (8.35 g) from glucose (29.30 g) produced from cellulose. After the reaction, the catalyst ZSM-5 was the main component in the solid residue and kept a suitable performance. THF azeotrope was easily separated from the slurry by evaporation. During the removal of THF, lignin was precipitated from the liquid phase and showed lower molecular weight and abundant active groups, which was a potential feedstock for producing valuable aromatics and polymers. Thus, in a one-pot reaction, the ideal yield of furan aldehydes from raw biomass was obtained on a lab scale, and the catalyst, THF, and LiBr were easily recycled, which provided an option to realize the economical production of sustainable furan aldehydes from raw biomass.

Shooting area of infrared camera traps affects recorded taxonomic richness and abundance of ground-dwelling invertebrates.

Ground-dwelling invertebrates are vital for soil biodiversity and function maintenance. Contemporary biodiversity assessment necessitates novel and automatic monitoring methods because of the threat of sharp reductions in soil biodiversity in farmlands worldwide. Using infrared camera traps (ICTs) is an effective method for assessing richness and abundance of ground-dwelling invertebrates. However, the influence that the shooting area of ICTs has on the diversity of ground-dwelling invertebrates has not been strongly considered during survey design. In this study, data from six ICTs with two shooting areas (A1, 38.48 cm2; A2, 400 cm2) were used to investigate ground-dwelling invertebrates in a farm in a city on the Eastern Coast of China from 20: 00 on July 31 to 00:00 on September 29, 2022. Over the course of 59 days and 1420 h, invertebrates within 9 taxa, 2447 individuals, and 112,909 ind./m2 were observed from 222,912 images. Our results show that ICTs with relatively large shooting areas recorded relatively high taxonomic richness and abundance of total ground-dwelling invertebrates, relatively high abundance of the dominant taxon, and relatively high daily and hourly abundance of most taxa. The shooting areas of ICTs significantly affected the recorded taxonomic richness and abundance of ground-dwelling invertebrates throughout the experimental period and at fine temporal resolutions. Overall, these results suggest that the shooting areas of ICTs should be considered when designing experiments, and ICTs with relatively large shooting areas are more favorable for monitoring the diversity of ground-dwelling invertebrates. This study further provides an automatic tool and high-quality data for biodiversity monitoring and protection in farmlands.

Preliminary Study on Hourly Dynamics of a Ground-Dwelling Invertebrate Community in a Farmland Vineyard.

We evaluated the hourly dynamics of ground-dwelling invertebrate communities in farmland using infrared camera traps between August and September 2022. No significant variations within 24 h nor between any two time points of each day were observed in the taxonomic richness and abundance of the entire community. However, the periods from 4:00 to 7:00 and 13:00 to 20:00 showed relatively high taxonomic richness, while those from 2:00 to 6:00 and 16:00 to 21:00 showed relatively high abundance. Millipede abundance varied significantly in a 24 h period, with higher abundance from 3:00 to 4:00 and 1:00 to 2:00. Additionally, slug, beetle, and grasshopper abundances were significantly higher from 22:00 to 23:00, 17:00 to 18:00, and 23:00 to 24:00, respectively. The abundance of other taxa did not show significant variations between any two time points of a day. Predominant generalist predators showed positive correlation in their activity times. These results suggest that significant variations within each 24 h period are uncommon at either community or taxa (except for millipedes) levels in farmland ground-dwelling invertebrates. Further, while most taxa had significantly preferred active hours, the total community did not. Therefore, hourly dynamics should be considered to understand biodiversity maintenance.

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Functional traits are indicators of the responses and adaptation of organisms to environmental changes and cascade to a series of ecosystem functions. The functional traits of soil animals are sensitive to environmental factors and may characterize and predict the changes of ecosystem functions. Multiple dimensions of biodiversity that combing species, phylogenetic, and functional diversity improves the understanding of distribution patterns, community assembly mechanisms and ecosystem functions of soil animals. In this review, we listed the categories of soil animal functional traits and their ecological significance, and summarized current researches on the responses of soil animal communities to environmental changes and the community assembly processes based on trait-based approaches. We proposed to strengthen the study on the impacts of eco-evolution processes of biotic interactions to soil animal functional traits, establish the database of soil animal functional traits, and apply trait-based approaches in the ecological restoration in the future, which would benefit soil biodiversity conservation and sustainability of soil ecosystems.

Soil nematode metacommunities in different land covers: Assessment at the local and regional scales.

The metacommunity theory enhances our understanding of how ecological processes regulate community structure. Yet, unraveling the complexities of soil nematode metacommunity structures across various spatial scales and determining the factors influencing these patterns remains challenging. Therefore, we conducted an investigation on soil nematode metacommunities spanning from north to south in the Northeastern China. Our aim was to test whether nematode metacommunities were structured by different drivers under three land covers (i.e., farmland, grassland and woodland) at the local and regional scales. The results revealed that the Clementsian, Gleasonian and their quasi-structures of soil nematodes collectively accounted for 93% of the variation across the three land covers at the local and regional scales. These structures suggest that the soil nematode metacommunities in the Northeast China responded to fluctuations in environmental gradients. At the local scale, metacommunities were primarily shaped by biological interactions. At the regional scale, environmental heterogeneity, dispersal limitation and biological interactions all contributed to nematode metacommunities. Meanwhile, biological interactions under three land covers were represented within different trophic groups, with plant parasites predominant in farmlands and bacterivores in grasslands and woodlands. In conclusion, the metacommunity structures of soil nematodes remain stable at different spatial scales and land covers. Biological interactions are widespread among nematodes regardless of changes in spatial scales and land covers. This study reveals the importance of nematode sensitivity to the environment and biological interactions in shaping the nematode metacommunities, potentially enhancing our understanding of the spatial patterns of nematode metacommunities.

Global fine-resolution data on springtail abundance and community structure.

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.

Description of the octopunctata-group species of Protaphorura from China (Collembola: Onychiuridae).

Protaphorura species of the octopunctata-group are recorded in China for the first time. Two new species, Protaphorura jiamusiensis sp. nov. and Protaphorura maoerensis sp. nov., and one species new to China, Protaphorura nutak, are reported. Protaphorura jiamusiensis sp. nov. is diagnosed mainly by the formula of pso on the body and subcoxae 1, the psx formula, the ratio of M/sp on Abd. V and the number of chaetae on Th. I-III sterna between the legs. Protaphorura maoerensis sp. nov. is similar to P. mongolica and P. sakatoi, but it can be easily distinguished from them by the dorsal pso formula.

Crop classification in high-resolution remote sensing images based on multi-scale feature fusion semantic segmentation model.

The great success of deep learning in the field of computer vision provides a development opportunity for intelligent information extraction of remote sensing images. In the field of agriculture, a large number of deep convolutional neural networks have been applied to crop spatial distribution recognition. In this paper, crop mapping is defined as a semantic segmentation problem, and a multi-scale feature fusion semantic segmentation model MSSNet is proposed for crop recognition, aiming at the key problem that multi-scale neural networks can learn multiple features under different sensitivity fields to improve classification accuracy and fine-grained image classification. Firstly, the network uses multi-branch asymmetric convolution and dilated convolution. Each branch concatenates conventional convolution with convolution nuclei of different sizes with dilated convolution with different expansion coefficients. Then, the features extracted from each branch are spliced to achieve multi-scale feature fusion. Finally, a skip connection is used to combine low-level features from the shallow network with abstract features from the deep network to further enrich the semantic information. In the experiment of crop classification using Sentinel-2 remote sensing image, it was found that the method made full use of spectral and spatial characteristics of crop, achieved good recognition effect. The output crop classification mapping was better in plot segmentation and edge characterization of ground objects. This study can provide a good reference for high-precision crop mapping and field plot extraction, and at the same time, avoid excessive data acquisition and processing.

Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning.

Application of Fiber Biochar-MOF Matrix Composites in Electrochemical Energy Storage.

Fiber biochar-metal organic framework (MOF) composites were successfully prepared by three different biochar preparation methods, namely, the ionic liquid method, the pyrolysis method, and the direct composite method. The effects of the different preparation methods of fiber biochar on the physical and chemical properties of the biochar-MOF composites showed that the composite prepared by the ionic liquid method with the Zeolite-type imidazolate skeleton -67 (ZIF-67) composite after high temperature treatment exhibited a better microstructure. Electrochemical tests showed that it had good specific capacity, a fast charge diffusion rate, and a relatively good electrochemical performance. The maximum specific capacity of the composite was 63.54 F/g when the current density was 0.01 A/g in 1 mol/L KCl solution. This work explored the preparation methods of fiber biochar-MOF composites and their application in the electrochemical field and detailed the relationship between the preparation methods of the composites and the electrochemical properties of the electrode materials.

Chalcone Derivatives and their Activities against Drug-resistant Cancers: An Overview.

Drug resistance, including multidrug resistance resulting from different defensive mechanisms in cancer cells, is the leading cause of the failure of the cancer therapy, posing an urgent need to develop more effective anticancer agents. Chalcones, widely distributed in nature, could act on diverse enzymes and receptors in cancer cells. Accordingly, chalcone derivatives possess potent activity against various cancers, including drug-resistant, even multidrug-resistant cancer. This review outlines the recent development of chalcone derivatives with potential activity against drug-resistant cancers covering articles published between 2010 and 2020 so as to facilitate further rational design of more effective candidates.

Bis-triazole-containing Compounds with Anticancer Potential: A Short Review.

The development of novel anticancer agents with high efficiency is of great importance due to the severe anticancer scenario of the currently used drugs. Dimerization is a useful method to develop new drug candidates with a broad biological spectrum, enhanced activity and potency to overcome drug resistance. A wide variety of bis-triazole-containing compounds have been developed with improved properties compared with their parent compounds. These derivatives could inhibit tumor proliferation, invasion and metastasis, revealing their potential as putative anticancer candidates. This review covers the recent advances of bis-triazole-containing compounds as anticancer candidates, and the structure-activity relationship are also discussed to set up the direction for the design and development of bis-triazole-containing compounds with higher efficiency.

Distribution characteristics of insect diversity in long-term fixed monitoring plots in Northeast China.

The spatial patterns of field arthropod communities are an essential part of ecology and can provide fundamental data regarding field ecological processes and reveal the mechanism of ecosystem biodiversity maintenance. This study investigated the spatial distribution pattern of field insect communities to detect the spatial relationships between insect communities in farmland. The study site was located at the Dehui Agro-ecological Experimental Station of Black Soil, Jilin, China. Insect communities and environmental factors were sampled at 121 uniformly distributed points in a 400 × 400 m plot in August, September, and October 2015. The analysis revealed that insect communities from June to October demonstrated significant spatial correlation, and 6085 samples of 47 species and 47 families in 11 orders were collected from the insect community in the farmland. The farmland insect community structure changes and dynamic changes of nutritional function groups occur with time. According to the 400 x 400 m plot, the diversity of farmland insect communities and functional groups is maintained at a relatively high and stable level. In this study, a total of 6085 samples of corn farmland insects were obtained using the fluke method and direct observation method, including 11 orders, 26 families and 47 species, 4 absolute dominant populations, 6 main dominant populations, and 37 other populations. These studies can provide help for pest control in the spring corn area of Northeast China.

Nature-derived anticancer steroids outside cardica glycosides.

Steriods which are ubiquitous in natural resources are important components of cell membranes and involved in several physiological functions. Steriods not only exerted the anticancer activity through inhibition of various enzymes and receptors in cancer cells, inclusive of aromatase, sulfatase, 5α-reductase, hydroxysteroid dehydrogenase and CYP 17, but also exhibited potential activity against various cancer forms including multidrug-resistant cancer with low cytotoxicity, and high bioavailability. Accordingly, steroids are useful scaffolds for the discovery of novel anticancer agents. This review aims to outline the advances of nature-derived steroids outside cardica glycosides with anticancer potential, covering the articles published between Jan. 2015 and Aug. 2020.

Recent advances of podophyllotoxin/epipodophyllotoxin hybrids in anticancer activity, mode of action, and structure-activity relationship: An update (2010-2020).

Podophyllotoxins and epipodophyllotoxins, possess excellent activity against both drug-sensitive and drug-resistant even multidrug-resistant cancer cells via inhibition of tubulin polymerization. Several podophyllotoxin/epipodophyllotoxin derivatives such as etoposide and teniposide have already been applied for cancer therapy, revealing their potential as putative anticancer drugs. Hybridization of podophyllotoxin/epipodophyllotoxin moiety with other anticancer pharmacophores is a promising strategy to develop novel drug candidates so as to overcome drug resistance and improve the specificity, and numerous of podophyllotoxin/epipodophyllotoxin hybrids exhibit excellent in vitro antiproliferative and in vivo anticancer potency. This review emphasizes the recent development of podophyllotoxin/epipodophyllotoxin hybrids with potential application for cancer therapy covering articles published between 2010 and 2020. The mechanisms of action, the critical aspects of design as well as structure-activity relationships were also summarized.

Two new onyсhiurid species (Collembola, Onychiurinae) inhabiting morel fruit bodies in southwest China.

Two new species Oligaphorura shifangensis sp. nov. and Onychiurus qingchuanensis sp. nov. living on mushrooms (morels) were reported from southwest China. Oligaphorura shifangensis sp. nov. is similar to known species O. schoetti (Lie-Pettersen, 1896), O. groenlandicus (Tullberg, 1876) and O. sibirica (Weiner Kaprus', 2014) as having the same pso formulae (32/133/33343 dorsally and 11/000/00000 ventrally), five papillae in AIIIO, subcoxae 1 of legs I-III with 1 pso each, 11 chaetae in the distal whorl of tibiotarsi, ms present on Th. II and III terga and the presence of anal spines; but they can easily be separated by the labial palp type, ventral psx formula, ratio of unguiculus/unguis and the presence/absence of cuticular fold in furcal remnant. Onychiurus qingchuanensis sp. nov. shares the number of dorsal pso with only three congeners, namely O. bhattii, O. fraterculi and O. steinmanni. They can easily be distinguished by the number of ventral and subcoxal pso, ventral psx and papillae on AIIIO.

Fabrication and excellent electroresponsive properties of ideal PMMA@BaTiO3 composite particles.

A series of core-shell-structured poly(methylmethacrylate)@BaTiO3 (PMMA@BT) composite particles were constructed via the self-assembly of BT nanoparticles on the surfaces of PMMA cores through the covalent bonding of siloxane groups at room temperature. The PMMA@BT composite particles were characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray diffraction, video-based optical contact angle measurement, thermogravimetric analysis, and impedance analysis. The electroresponses of the obtained PMMA@BT composite particles were all stronger than that of pure BT, and the electroresponse depended on the weight percentage of the BT shell. The PMMA@BT particles with the optimal core-shell structure contained 58.14 wt% of BT shell. The surface hydrophilicity of the optimal particles was close to that of pure BT, and the dielectric constant was the greatest among the series of synthesized PMMA@BT particles. Thus, the optimized PMMA@BT particles demonstrated the strongest electroresponsive behavior in gelatin hydrogel elastomer, as demonstrated by polarized microscopy and dynamic mechanical analysis. The excellent electroresponsive property of the optimal PMMA@BT particles is reflected by the large sensitivity of the increase in storage modulus for the gelatin hydrogel elastomer containing the composite particles (21% at E = 0.8 kV mm-1 and a particle loading of 1.0 wt%), far greater than that of pure BT particles (4.7%). Based on the sensitive electroresponsive properties, the PMMA@BT particles have potential applications as electroresponsive materials.

Benzofuran-isatin-imine hybrids tethered via different length alkyl linkers: Design, synthesis and in vitro evaluation of anti-tubercular and anti-bacterial activities as well as cytotoxicity.

Herein we report the design and synthesis of twenty-two novel benzofuran-isatin-imine hybrids 7a-v tethered through propylene, butylene, pentylene and hexylene, and for the evaluation of their in vitro anti-tubercular and anti-bacterial activities as well as cytotoxicity. All benzofuran-isatin-imine hybrids exhibited considerable in vitro anti-TB (MIC: <0.016-0.218 µg/mL and 0.062-14.15 µg/mL against drug-sensitive and MDR MTB, respectively) and anti-bacterial (MIC: 0.25-64 µg/mL and 0.06-16 µg/mL against Gram-positive and Gram-negative strains, respectively) activities. All of them also showed acceptable cytotoxicity towards VERO (CC50: 8-128 µg/mL). The most active hybrid 7j (MIC: <0.016, 0.062 and 0.16 µg/mL, respectively) was >4.8 and ≥ 48 folds more potent than the first line anti-TB agents RIF and INH against both drug-sensitive MTB H37Rv and MDR-TB isolates, respectively. Moreover, hybrid 7j also demonstrated promising anti-bacterial activities with MIC values of ≤1 µg/mL against the majority of the tested Gram-negative and Gram-positive pathogens, which was comparable to vancomycin (MIC: 0.5-4 µg/mL) and CPFX (MIC: 0.125-8 µg/mL) against Gram-positive bacteria, but slightly less potent than CPFX (MIC: ≤0.03-0.5 µg/mL) against Gram-negative bacteria. The results indicated that benzofuran-isatin-imine hybrids could act as candidates for the development of anti-TB and anti-bacterial agents.