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Objectives: This study investigated the genotype-specific dynamics of molecular HIV clusters (MHCs) in Guangzhou, China, aiming to enhance HIV control. Methods: HIV pol sequences from people with HIV (PWH) in Guangzhou (2008-2020) were obtained for genotyping and molecular network creation. MHCs were identified and categorized into three types: emerging, growing, or stable. Clustering rates, proportions of cluster types, and members within each type were calculated and their trends were assessed using joinpoint regression. Results: Among 8395 PWH, the most prevalent HIV-1 genotypes were CRF07_BC (39.7%) and CRF01_AE (32.6%). The genotype composition has been stable since 2012 (Ps > 0.05). The overall clustering rate was 43.3%, with significant variations across genotypes (P < 0.001), indicating genotype-specific transmission fitness. Significant declines in overall and genotype-specific clustering rates toward the end of 2020 (Ps < 0.05), potentially offer support for HIV control efforts in reducing local infections. The continuously increasing proportions of stable clusters and the gradually decreasing proportions of emerging and growing clusters (either Ps < 0.05 or Ps > 0.05) suggest a trend toward stable molecular network structure. However, growing clusters exhibited CRF55_01B, CRF07_BC, and CRF59_01B dominance that indicate their priority for interventions. Conclusion: The evolving MHCs highlight the genotype-specific cluster dynamics, providing fresh insights for enhanced prevention and control strategies.

Abstract Polygonatum cyrtonema Hua is a traditional Chinese medicinal plant acclaimed for its therapeutic potential in diabetes and various chronic diseases. Its rhizomes are the main functional parts rich in secondary metabolites, such as flavonoids and saponins. But their quality varies by region, posing challenges for industrial and medicinal application of P. cyrtonema. In this study, 482 metabolites were identified in P. cyrtonema rhizome from Qingyuan and Xiushui counties. Cluster analysis showed that samples between these two regions had distinct secondary metabolite profiles. Machine learning methods, specifically support vector machine-recursive feature elimination and random forest, were utilized to further identify metabolite markers including flavonoids, phenolic acids, and lignans. Comparative transcriptomics and weighted gene co-expression analysis were performed to uncover potential candidate genes including CHI, UGT1, and PcOMT10/11/12/13 associated with these compounds. Functional assays using tobacco transient expression system revealed that PcOMT10/11/12/13 indeed impacted metabolic fluxes of the phenylpropanoid pathway and phenylpropanoid-related metabolites such as chrysoeriol-6,8-di-C-glucoside, syringaresinol-4'-O-glucopyranosid, and 1-O-Sinapoyl-D-glucose. These findings identified metabolite markers between these two regions and provided valuable genetic insights for engineering the biosynthesis of these compounds.

Few-shot hyperspectral image classification aims to develop the ability of classifying image pixels by using relatively few labeled pixels per class. However, due to the inaccuracy of the localization system and the bias of the ground survey, the potential noisy labels in the training data pose a very significant challenge to few-shot hyperspectral image classification. To solve this problem, this paper proposes a weighted contrastive prototype network (WCPN) for few-shot hyperspectral image classification with noisy labels. WCPN first utilizes a similarity metric to generate the weights of the samples from the same classes, and applies them to calibrate the class prototypes of support and query sets. Then the weighted prototype network will minimize the distance between features and prototypes to train the network. WCPN also incorporates a weighted contrastive regularization function that uses the sample weights as gates to filter the fake positive samples whose labels are incorrect to further improve the discriminative power of the prototypes. We conduct experiments on multiple hyperspectral image datasets with artificially generated noisy labels, and the results show that the WCPN has excellent performance that can sufficiently mitigate the impact of noisy labels.

Enhancing crop nitrogen use efficiency (NUE) in agricultural sciences is a pivotal challenge, particularly for high-demand crops like potatoes (Solanum tuberosum L.), the world’s third most significant food crop. This study delves into the molecular responses of potatoes to low nitrogen (LN) stress, employing an integrative approach that combines transcriptomics and metabolomics to compare two cultivars with divergent NUE traits: XS6, known for its high NUE, and NS7, characterized by lower NUE. Our research unveils that XS6 exhibits higher chlorophyll and N content, increased tuber yield, and elevated N assimilation capacity under LN stress conditions compared to NS7. Through transcriptome analysis, we identified critical genes involved in C and N metabolism that had higher expression in XS6. A significant discovery was the high-affinity nitrate transporter 2.7 gene, which showed elevated expression in XS6, suggesting its key role in enhancing NUE. Metabolomics analysis further complemented these findings, revealing a sophisticated alteration of 1252 metabolites under LN stress, highlighting the dynamic interplay between carbon and N metabolism in coping with N scarcity. The integration of transcriptomic and metabolomic data underscored the crucial role of trehalose in mitigating N deficiency and enhancing NUE. This study provides novel insights into the molecular mechanisms governing NUE in potatoes, offering valuable perspectives for molecular breeding to enhance NUE in potatoes and potentially other crops.

Abstract Diet‐related chronic diseases are becoming more common where many consumers and nutritionists are seeking food and lifestyle interventions to improve health and standard of living. To supplement regular dietary intake, scientists are seeking to develop new crops that are productive and nutritious, which can improve health outcomes. This review focused on the history of Huangjing as a medicine, healthy food as part of a diverse diet and as an input into pharmacology uses. The sustainable production of Huangjing and the development of health‐promoting Huangjing products are reviewed through consulting the “Chinese Pharmacopoeia” along with other herbal textual research and modern research publications. Hence, the potential development of Huangjing as a regular part of a healthy diet is discussed. Huangjing has been used as medicine and food in China for over 2000 years. While it contains no starch, it is rich in fructan, saponins, and flavonoids, which have been reported to prevent and treat chronic diseases such as diabetes and obesity. As part of a healthy diet, Huangjing has been developed into innovative products used in meals, snacks, drinks, health foods, and drugs. Furthermore, Huangjing is a perennial plant, is suitable for cultivation in forests, and does not occupy fertile farmland. It is proposed to use the achievements of genomics and targeted precision breeding to make in‐forest cultivation of Huangjing more productive, comprehensively nutritious, and environmentally friendly and obtain high‐quality food from forests and mountains, providing Chinese wisdom for the global food and nutrition security issue.

Land use is a reflection of human activities in surface space, and classifying it helps better understand the relationship between human activities and the spatial environment. However, the imbalance in land use datasets acquired through remote sensing images has become a major obstacle to improving the accuracy of land use classification. To maintain the balance in the samples of the land use dataset and improve the accuracy of land use classification, this article proposes an improved model based on the DeepLab V3+ network under the GauGAN data enhancement strategy. First, regarding the data imbalance problem, this article proposes an attention optimization mechanism to enhance the learning ability of the generator of GauGAN for contextual semantic information, and adds spectral normalization to the discriminator to induce stable model training. Thus, the model can synthesize excellent small-sample feature data. For the land use classification model, this article improves the DeepLab V3+ network by modifying the expansion rate of the ASPP module and adding the proposed feature fusion module to enhance the ability of the model for combining high- and low-level semantic features. Finally, this article implements both of the proposed improvements to achieve high-precision land use classification. The results showed the following. The land use data synthesized by improved GauGAN contained more complex semantic information and detailed features than the synthetic results of other models, and thus better represented the features of land use. The improved DeepLab V3+ model outperformed the U-Net, FPN, DeepLab V3+, MANet, and TransUNet.

Abstract Background People living with HIV(PLWH) are deemed more vulnerable to the SARS-CoV-2 infection than the uninfected population. Vaccination is an effective measure for COVID-19 control, yet, little knowledge exists about the willingness of men who have sex with men (MSM) living with HIV in China to be vaccinated. Methods This cross-sectional study evaluated the willingness of MSM living with HIV to receive COVID-19 vaccination in six cities of Guangdong, China, from July to September 2020. Factors associated with willingness to receive COVID-19 vaccination using multivariable logistic regression. Results In total, we recruited 944 HIV-positive MSM with a mean age of 29.2 ± 7.7 years. Of all participants, 92.4% of them were willing to receive the COVID-19 vaccine. Participants who were separated, divorced, or widowed (adjusted OR: 5.29, 95%CI: 1.02–27.48), had an annual income higher than 9,000 USD (adjusted OR: 1.70, 95%CI: 1.01–2.86), had ever taken an HIV self-test (adjusted OR: 1.78, 95%CI: 1.07–2.95), had ever disclosed sexual orientation to a doctor/nurse (adjusted OR: 3.16, 95%CI: 1.33–7.50), had ever disclosed sexual orientation to others besides their male partners (adjusted OR: 2.18, 95%CI: 1.29–3.69) were more willing to receive the vaccine. Sex with a female partner in the past six months decreased the likelihood of willingness to receive the vaccine (adjusted OR: 0.40, 95%CI: 0.17–0.95). Economic burden, worry that my health condition could not bear the risk of receiving COVID-19 vaccines, and concern that the vaccination would affect the immune status and antiretroviral therapy were the main reasons for unwillingness to receive vaccination. Conclusion Our study showed that HIV-positive MSM had a high willingness to receive the COVID-19 vaccination. Targeted interventions such as health education should be conducted among MSM with HIV infection to enhance COVID-19 vaccine uptake.

Klebsiella aerogenes is a common infectious bacterium that poses a threat to human health. Nevertheless, there are limited data on the population structure, genetic diversity, and pathogenicity of K. aerogenes, especially among men who have sex with men (MSM). The present study aimed to clarify the sequence types (STs), clonal complexes (CCs), resistance genes, and virulence factors of popular strains. Multilocus sequence typing was used to describe the population structure of K. aerogenes. The Virulence Factor Database and Comprehensive Antibiotic Resistance Database were used to assess the virulence and resistance profiles. In this study, next-generation sequencing was performed on nasal swabs specimens collected in an HIV Voluntary Counseling Testing outpatient department in Guangzhou, China, from April to August 2019. The identification results showed that a total of 258 K. aerogenes isolates were collected from 911 participants. We found that the isolates were most resistant to furantoin (89.53%, 231/258) and ampicillin (89.15%, 230/258), followed by imipenem (24.81%, 64/258) and cefotaxime (18.22%, 47/258). The most common STs in carbapenem-resistant K. aerogenes were ST4, ST93, and ST14. The population has at least 14 CCs, including several novel ones identified in this study (CC11-CC16). The main mechanism of drug resistance genes was antibiotic efflux. Based on the presence of the iron carrier production genes irp and ybt, we identified two clusters according to virulence profiles. In cluster A, CC3 and CC4 carry the clb operator encoding the toxin. Increased monitoring is needed for the three main ST type strains carried by MSM. The main clone group CC4 has a large number of toxin genes, and it spreads among MSM. Caution is needed to prevent further spread of this clone group in this population. In sum, our results may provide a foundation for the development of new therapeutic and surveillance strategies for treating MSM.

The United Nations Sustainable Development Goals (SDGs) and the rise of global sustainability science have led to the increasing recognition of basins as the key natural geographical units for human–land system coupling and spatial coordinated development. The effective measurement of spatiotemporal patterns of urban connectivity within a basin has become a key issue in achieving basin-related SDGs. Meanwhile, China has been actively working toward co-ordinated regional development through in-depth implementation of the Yellow River Basin’s ecological protection and high-quality development. Urban connectivity has been trending in urban planning, and significant progress has been made on different scales according to the flow space theory. Nevertheless, few studies have been conducted on the multiscale spatiotemporal patterns of urban agglomeration connectivity. In this study, the urban network in the Yellow River Basin was constructed using Tencent population migration data from 2015 and 2019. It was then divided into seven distinct communities to enable analysis at both the basin and community scales. Centrality, symmetry, and polycentricity indices were employed, and the multiscale spatiotemporal patterns of urban agglomerations in the Yellow River Basin were identified using community detection, complex networks, and the migration kaleidoscope method. Community connectivity was notably concentrated at the basin scale with a centripetal pattern and spatial heterogeneity. Additionally, there was a symmetrical and co-ordinated relationship in population migration between the eastern and western regions of the basin, as well as between the internal and external parts of the basin. At the community scale, there was significant variation in the extent of central agglomeration among different communities, with few instances of similar-level, long-distance, and interregional bilateral links. The utilization of multiscale spatiotemporal patterns has the potential to enhance the comprehension of economic cooperation between various cities and urban agglomerations. This understanding can aid decision-makers in formulating sustainable development policies that foster the spatial integration of the basin.

Hydrocolloids have been widely used to adjust properties of natural starches, but related research on kudzu starch is still rare. In this study, we investigated the effects of gum arabic (AG), sodium alginate (SA), locust bean gum (LG), and guar gum (GG) on kudzu starch from the perspective of its particle size, pasting, texture, rheology, dehydration rate, thermal properties, microstructure, and sensitivity to amyloglucosidase. Results showed that GG significantly increased the particle size of starch. Addition of AG led to lower peak-, final- and holding-viscosity. SA increased the retention viscosity of kudzu starch, while LG and GG increased its peak viscosity. Addition of hydrocolloids increased the hardness, chewiness, and cohesiveness of starch-hydrocolloid complexes, and reduced the dehydration rate of complex gels. Dynamic rheological data showed that the energy storage modulus (G′) was significantly higher than the loss modulus (G″). The magnitude of modulus increased with frequency, and elastic properties were better than viscous properties. Thermal analysis showed that hydrocolloids increased the starting temperature (To), and the final temperature (Tc). With addition of each of these four hydrocolloids, a more regular and porous thick-wall dense structure was formed, which effectively lowered kudzu starch's sensitivity to amyloglucosidase. It indicated that the binding of hydrocolloid to starch may slow down glucose release into blood during digestion. These results will help understand effects of natural hydrocolloid on kudzu starch, as well as expanding its application in food industry.

With the increasing power of fiber lasers, single chirped and tilted fiber Bragg gratings (CTFBGs) cannot completely mitigate continuously enhanced system-excited stimulated Raman scattering (SRS). Although improving the loss rate of a single CTFBG or cascading multiple CTFBGs can provide better suppression of the stronger SRS, excessive insertion loss may cause significant attenuation of the output power. Confronting the challenge, we firstly present an SRS mitigation method based on a dual-structure fiber grating in this paper. The dual-structure fiber grating comprises a CTFBG and a fiber Bragg grating structure, which were designed and fabricated on a passive 25/400 double-clad fiber. To evaluate the performance of the grating, a 3 kW fiber master oscillator power amplifier laser is established. The experimental results demonstrate that the SRS mitigation rate of the grating is greater than 30 dB (99.9%), whereas the insertion loss is only approximately 3%, thus allowing for minimal deterioration of the output power. This solves the contradiction between high suppression rate and high insertion loss faced by CTFBGs, which in turn makes dual-structure fiber gratings particularly suitable for mitigating SRS in 3–5 kW high-power fiber lasers.

Fructans, fructose polymers, are one of the three major reserve carbohydrate in plants. The nutritional and therapeutic benefits of natural fructans in plants have attracted increasing interest by consumers and food industry. In the course of evolution, many plants have developed the ability of regulating plant fructans metabolism to produce fructans with different structures and chain lengths, which are strongly correlated with their survival in harsh environments. Exploring these evolution-related genes in fructans biosynthesis and de novo domestication of fructans-rich plants based on genome editing is a viable and promising approach to improve human dietary quality and reduce the risk of chronic disease. These advances will greatly facilitate breeding and production of tailor-made fructans as a healthy food ingredient from wild plants such as huangjing (Polygonatum cyrtonema). The purpose of this review is to broaden our knowledge on plant fructans biosynthesis, evolution and benefits to human health.

Background: Savolitinib, a selective MET inhibitor, showed efficacy in patients with non-small cell lung cancer (NSCLC), including pulmonary sarcomatoid carcinoma (PSC), harbouring MET exon 14 skipping alteration ( MET ex14). Objective: To analyse post hoc , the association between circulating tumour DNA (ctDNA) biomarkers and clinical outcomes, including resistance, with savolitinib. Design: A multicentre, single-arm, open-label phase 2 study. Methods: All enrolled patients with baseline plasma samples were included. Outcomes were objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) by baseline MET ex14 and post-treatment clearance, coexisting gene alterations at baseline and disease progression. Results: Among 66 patients with baseline ctDNA sequencing, 46 (70%) had detectable MET ex14. Frequent coexisting baseline gene alterations included TP53 and POT1 mutations. Patients with detectable baseline MET ex14 exhibited worse PFS [hazard ratio (HR), 1.77; 95% confidence interval (CI), 0.88–3.57; p = 0.108] and OS (HR, 3.26; 95% CI, 1.35–7.89; p = 0.006) than those without, despite showing a numerically higher ORR. Among 24 patients with baseline detectable MET ex14 and evaluable postbaseline samples, 13 achieved MET ex14 clearance post-treatment. Median time to first clearance was 1.3 months (range, 0.7–1.5). MET ex14 post-treatment clearance was associated with better ORR (92.3%; 95% CI, 64.0–99.8 versus 36.4%; 95% CI, 10.9–69.2; p = 0.0078), PFS (HR, 0.44; 95% CI, 0.2–1.3; p = 0.1225) and OS (HR, 0.31; 95% CI, 0.1–1.0; p = 0.0397) versus non-clearance. Among 22 patients with disease progression, 10 acquired pathway alterations (e.g. in RAS/RAF and PI3K/PTEN) alone or with secondary MET mutations (D1228H/N and Y1230C/H/S). Conclusion: ctDNA biomarkers may allow for longitudinal monitoring of clinical outcomes with savolitinib in patients with MET ex14-positive PSC and other NSCLC subtypes. Specifically, undetectable baseline MET ex14 or post-treatment clearance may predict favourable clinical outcomes, while secondary MET mutations and other acquired gene alterations may explain resistance to savolitinib. Registration: The trial was registered with ClinicalTrials.gov (NCT02897479) on 13 September 2016.

Introduction: Savolitinib has been found to have encouraging antitumor activity and a favorable safety profile in Chinese patients with pulmonary sarcomatoid carcinoma and other NSCLCs with MET exon 14 skipping alterations (MET ex14 positive) at the primary analysis of a phase 2 study. Here, we present the long-term efficacy and safety data of savolitinib, including subgroup analyses. Methods: This multicenter, single-arm, open-label, phase 2 study in the People’s Republic of China enrolled MET inhibitor-naive adults with locally advanced or metastatic METex14-positive NSCLC (NCT02897479). Oral savolitinib at a dose of 400 or 600 mg was administered once daily (body weight dependent). The primary objectives of the final analysis were long-term overall survival (OS) and subgroup analyses by previous systemic treatment, NSCLC subtypes, and brain metastases. Results: At the final analysis cutoff date (June 28, 2021), a total of 70 patients were enrolled and receiving savolitinib, and median follow-up was 28.4 (interquartile range: 26.2–36.3) months. The median OS was 12.5 months (95% confidence interval [CI]: 10.5–21.4 [18- and 24-mo OS rates, 42.1% and 31.5%, respectively]). Median OS in pretreated or treatment-naive patients was 19.4 (95% CI: 10.5–31.3) and 10.9 (95% CI: 7.5–14.0) months, respectively; it was 10.6 months (95% CI: 4.6–14.0) in patients with pulmonary sarcomatoid carcinoma, 17.3 months (95% CI: 10.6–23.6) in other NSCLC subtypes, and 17.7 months (95% CI: 10.5–not evaluable) in patients with brain metastases. No new safety signals emerged with prolonged follow-up and exposure. Conclusions: The updated results further confirm the favorable benefit and acceptable safety of savolitinib in Chinese patients with METex14-positive NSCLC.

Abstract Background Dendrobium catenatum belongs to the Orchidaceae, and is a precious Chinese herbal medicine. In the past 20 years, D. catenatum industry has developed from an endangered medicinal plant to multi-billion dollar grade industry. The necrotrophic pathogen Sclerotium delphinii has a devastating effection on over 500 plant species, especially resulting in widespread infection and severe yield loss in the process of large-scale cultivation of D. catenatum. It has been widely reported that Jasmonate (JA) is involved in plant immunity to pathogens, but the mechanisms of JA-induced plant resistance to S. delphinii are unclear. Results In the present study, the role of JA in enhancing D. catenatum resistance to S. delphinii was investigated. We identified 2 COI1, 13 JAZ, and 12 MYC proteins in D. catenatum genome. Subsequently, systematic analyses containing phylogenetic relationship, gene structure, protein domain, and motif architecture of core JA pathway proteins were conducted in D. catenatum and the newly characterized homologs from its closely related orchid species Phalaenopsis equestris and Apostasia shenzhenica, along with the well-investigated homologs from Arabidopsis thaliana and Oryza sativa. Public RNA-seq data were investigated to analyze the expression patterns of D. catenatum core JA pathway genes in various tissues and organs. Transcriptome analysis of MeJA and S. delphinii treatment showed exogenous MeJA changed most of the expression of the above genes, and several key members, including DcJAZ1/2/5 and DcMYC2b, are involved in enhancing defense ability to S. delphinii in D. catenatum. Conclusions The findings indicate exogenous MeJA treatment affects the expression level of DcJAZ1/2/5 and DcMYC2b, thereby enhancing D. catenatum resistance to S. delphinii. This research would be helpful for future functional identification of core JA pathway genes involved in breeding for disease resistance in D. catenatum.

Abstract Background HIV testing is an essential gateway to HIV prevention and treatment thus controlling the HIV epidemic. More innovative interventions are needed to increase HIV testing among men who have sex with men (MSM) since their testing rate is still low. We proposed an online HIV test results exchange mechanism whereby the one without a certified online HIV report will be asked to test HIV for exchanging HIV report with others. The exchange mechanism is developed as an extension to the existing online HIV testing service system. Through the extended system, MSM can obtain certified online HIV reports and exchange their reports with friends via WeChat. This study aims to assess effectiveness of the exchange mechanism to increase the HIV testing rate among MSM. Methods This study will use a cluster randomized controlled trial (RCT) design. Participants are recruited based on the unit of individual social network, the sender and the receivers of the HIV report. An individual social network is composed of one sender (ego) and one or more receivers (alters). In this study, MSM in an HIV testing clinic are recruited as potential egos and forwarded online reports to their WeChat friends voluntarily. Friends are invited to participate by report links and become alters. Ego and alters serve as a cluster and are randomized to the group using the certified online HIV report with exchange mechanism (intervention group) or without exchange mechanism (control group). Alters are the intervention targeting participants. The primary outcome is HIV testing rate. Other outcomes are sexual transmitted infections, sexual behaviors, HIV testing norms, stigma, risk perception and HIV report delivery. The outcomes will be assessed at baseline and follow-up questionnaires. Analysis will be according to intention to treat approach and using mixed-effect models with networks and individuals as random effects. Discussion This is the first study to evaluate the effectiveness of an HIV test result exchange mechanism to increase the HIV testing among MSM. This assessment of the intervention will also provide scientific evidence on other potential effects. Findings from this study will yield insights for sustainability driven by communities' intrinsic motivation. Trail registration: ClinicalTrials.gov NCT03984136. Registered 12 June 2019.

Dendrobium catenatum, belonging to the Orchidaceae, is a precious Chinese herbal medicine. Sclerotium delphinii (P1) is a broad-spectrum fungal disease, which causes widespread loss in the near-wild cultivation of D. catenatum. Thus, resistance breeding of D. catenatum has become the key to solve this problem. The basic helix–loop–helix (bHLH) gene family is closely related to plant resistance to external stresses, but the related research in D. catenatum is not deep enough yet. Phylogenetic analysis showed that 108 DcbHLH genes could be divided into 23 subgroups. Promoter cis-acting elements revealed that DcbHLHs contain a large number of stress-related cis-acting elements. Transcriptome analysis of MeJA and P1 treatment manifested that exogenous MeJA can change the expression pattern of most bHLH genes, especially the IIIe subgroup, including inhibiting the expression of DcbHLH026 (MYC2a) and promoting the expression of DcbHLH027 (MYC2b). Subcellular localization indicated that they were located in the nucleus. Furthermore, exogenous MeJA treatment significantly delayed disease time and reduced lesion size after infection with P1. DcMYC2b-overexpression Arabidopsis lines showed significantly smaller lesions after being infected with P1 than the wild type, indicating that DcMYC2b functions as an important positive regulator in D. catenatum defense against P1. Our findings shed more insights into the critical role of the DcbHLH family in plants and the resistance breeding of D. catenatum.

Dendrobium catenatum, a traditional precious Chinese herbal medicine, belongs to epiphytic orchids. Its special life mode leads to the specialization of roots, but there is a lack of systematic research. The aerial root in D. catenatum displays diverse unique biological characteristics, and it initially originates from the opposite pole of the shoot meristem within the protocorm. The root development of D. catenatum is not only regulated by internal cues but also adjusts accordingly with the change in growth environments. D. catenatum root is highly tolerant to auxin, which may be closely related to its epiphytic life. Exogenous auxin treatment has dual effects on D. catenatum roots: relatively low concentration promotes root elongation, which is related to the induced expression of cell wall synthesis genes; excessive concentration inhibits the differentiation of velamen and exodermis and promotes the overproliferation of cortical cells, which is related to the significant upregulation of WOX11-WOX5 regeneration pathway genes and cell division regulatory genes. Overexpression of D. catenatum WOX12 (DcWOX12) in Arabidopsis inhibits cell and organ differentiation, but induces cell dedifferentiation and callus production. Therefore, DcWOX12 not only retains the characteristics of ancestors as stem cell regulators, but also obtains stronger cell fate transformation ability than homologous genes of other species. These findings suggest that the aerial root of D. catenatum evolves special structure and developmental characteristics to adapt to epiphytic life, providing insight into ideal root structure breeding of simulated natural cultivation in D. catenatum and a novel target gene for improving the efficiency of monocot plant transformation.

Sunflower is one of the most important oil crops in the world, and drought stress can severely limit its production and quality. To understand the underlying mechanism of drought tolerance, and identify candidate genes for drought tolerance breeding, we conducted a combined genome-wide association studies (GWAS) and RNA-seq analysis. A total of 226 sunflower inbred lines were collected from different regions of China and other countries. Eight phenotypic traits were evaluated under control and drought stress conditions. Genotyping was performed using a Specific-Locus Amplified Fragment Sequencing (SLAF-seq) approach. A total of 934.08 M paired-end reads were generated, with an average Q30 of 91.97%. Based on the 243,291 polymorphic SLAF tags, a total of 94,162 high-quality SNPs were identified. Subsequent analysis of linkage disequilibrium (LD) and population structure in the 226 accessions was carried out based on the 94,162 high-quality SNPs. The average LD decay across the genome was 20 kb. Admixture analysis indicated that the entire population most likely originated from 11 ancestors. GWAS was performed using three methods (MLM, FarmCPU, and BLINK) simultaneously. A total of 80 SNPs showed significant associations with the 8 traits (p < 1.062 × 10−6). Next, a total of 118 candidate genes were found. To obtain more reliable candidate genes, RNA-seq analysis was subsequently performed. An inbred line with the highest drought tolerance was selected according to phenotypic traits. RNA was extracted from leaves at 0, 7, and 14 days of drought treatment. A total of 18,922 differentially expressed genes were obtained. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed up-regulated genes were mainly enriched in the branched-chain amino acid catabolic process, while the down-regulated genes were mainly enriched in the photosynthesis-related process. Six DEGs were randomly selected from all DEGs for validation; these genes showed similar patterns in RNA-seq and RT-qPCR analysis, with a correlation coefficient of 0.8167. Through the integration of the genome-wide association study and the RNA-sequencing, 14 candidate genes were identified. Four of them (LOC110885273, LOC110872899, LOC110891369, LOC110920644) were abscisic acid related protein kinases and transcription factors. These genes may play an important role in sunflower drought response and will be used for further study. Our findings provide new insights into the response mechanisms of sunflowers against drought stress and contribute to further genetic breeding.

Background: Coagulase-negative Staphylococci (CoNS) are opportunistic pathogens. Methicillin-resistant CoNS (MRCoNS) remain a major cause of nosocomial infections, but limited information is available in communities. We, therefore, aimed to investigate the epidemiology of CoNS nasal carriage, especially MRCoNS in community-based drug users. Methods: Drug users were included in the cross-sectional study from three communities in Guangzhou, China. A face-to-face questionnaire was used to collect individual information and nasal swabs were collected to identify CoNS and MRCoNS isolates. Phenotypic and genotypic characterization of MRCoNS isolates were detected by using the disk diffusion method and polymerase chain reaction assays. Factors impacting MRCoNS carriage were assessed and estimated odds ratios (ORs) and 95% confidence intervals (CIs) by using logistic regression models. Results: Overall, 353 drug users were eligible and included in the study. The prevalence of CoNS and MRCoNS were 42.78% and 29.18%, respectively. Having a history of being in prison (aOR = 2.16, 95% CI: 1.10−4.22) and a history of heroin snorting in the past 6 months (aOR = 1.87, 95% CI: 1.14−3.05) were risk factors for MRCoNS nasal carriage in drug users. The proportions of multidrug resistance for CoNS and MRCoNS isolates were respectively 54.38% and 66.07%. The predominant multidrug resistance pattern for CoNS and MRCoNS isolates was simultaneously non-susceptible to penicillin, cefoxitin and trimethoprim-sulfamethoxazole. MRCoNS isolates that were positive for erythromycin- (χ2 = 15.49, P < 0.001), tetracycline- (χ2 = 44.88, P < 0.001), penicillin- (χ2 = 3.86, P = 0.049), clindamycin- (χ2 = 4.18, P = 0.028), and gentamicin- (χ2 = 20.66, P < 0.001) resistance genes had significantly higher rates of resistance to corresponding antibiotics. Conclusions: The prevalence of MRCoNS nasal carriage was high in community-based drug users. Drug users with risk factors should be paid greater attention to. The use of antibiotics in drug users needs further investigation and control.

Abstract Background Staphylococcus aureus (S. aureus), particularly methicillin-resistant Staphylococcus aureus (MRSA), remains the predominant cause of infections in drug users. This cross-sectional study aims to elucidate the prevalence, risk factors, phenotypic and molecular characteristics of S. aureus carriage among community-based drug users. Methods All eligible drug users, with both injection and non-injection route of drug administration, were asked to complete questionnaires and collect nasal swabs by trained personal during the period between May and December 2017 in Guangzhou, China. Swabs were processed for identification of S. aureus. Antimicrobial susceptibility test and polymerase chain reaction assays were used to detect phenotypic and molecular characteristics for identified isolates. Univariate and multivariate logistic regression analyses were used to assess risk factors for S. aureus carriage. Results Overall, 353 drug users were included in the study and the prevalence of S. aureus carriage was 15.01% (53/353). The prevalence of MRSA carriage was 6.80% (24/353). Cohabitation was a risk factor for S. aureus (adjusted OR = 8.80, 95% CI: 1.89–40.99). The proportion of multidrug resistance was 54.72% for S. aureus isolates and most of these isolates were resistant to penicillin, erythromycin and clindamycin. Seventeen MRSA isolates were multidrug resistant. The results of clonal complexes (CCs) and sequence types (STs) for S. aureus were diverse. The three predominant types for CCs were CC5 (64.15%, 34/53), CC59 (11.32%, 6/53), and CC7 (7.55%, 4/53); and for STs were ST188 (20.75%, 11/53), ST5 (11.32%, 6/53), and ST59 (11.32%, 6/53). Conclusion The prevalence of S. aureus nasal carriage was lower while the prevalence of MRSA carriage was moderate compared to previous studies. Phenotypic and molecular characteristics of S. aureus isolates, particularly MRSA isolates, revealed high proportions of antibiotic resistance, indicating the existence of cross-circulation, and implying high opportunity of virulence-related diseases. Decolonization and antibiotic stewardship might be implemented for drug users with MRSA carriage.

Abstract At the microsite “Evolution Slope”, Tabigha, Israel, wild barley (Hordeum spontaneum) populations adapted to dry Terra Rossa soil, and its derivative abutting wild barley population adapted to moist and fungi‐rich Basalt soil. However, the mechanisms underlying the edaphic adaptation remain elusive. Accordingly, whole genome bisulfite sequencing, RNA‐sequencing, and metabolome analysis are performed on ten wild barley accessions inhabiting Terra Rossa and Basalt soil. A total of 121 433 differentially methylated regions (DMRs) and 10 478 DMR‐genes are identified between the two wild barley populations. DMR‐genes in CG context (CG‐DMR‐genes) are enriched in the pathways related with the fundamental processes, and DMR‐genes in CHH context (CHH‐DMR‐genes) are mainly associated with defense response. Transcriptome and metabolome analysis reveal that the primary and secondary metabolisms are more active in Terra Rossa and Basalt wild barley populations, respectively. Multi‐omics analysis indicate that sugar metabolism facilitates the adaptation of wild barley to dry Terra Rossa soil, whereas the enhancement of phenylpropanoid/phenolamide biosynthesis is beneficial for wild barley to inhabit moist and fungi pathogen‐rich Basalt soil. The current results make a deep insight into edaphic adaptation of wild barley and provide elite genetic and epigenetic resources for developing barley with high abiotic stress tolerance.

Road vulnerability is crucial for enhancing the robustness of urban road networks and urban resilience. In medium or large cities, road failures in the face of unexpected events, such as heavy rainfall, can affect regional traffic efficiency and operational stability, which can cause high economic losses in severe cases. Conventional studies of road cascading failures under unexpected events focus on dynamic traffic flow, but the significant drop in traffic flow caused by urban flooding does not accurately reflect road load changes. Meanwhile, limited studies analyze the spatiotemporal pattern of cascading failure of urban road networks under real rainstorms and the correlation of this pattern with road vulnerability. In this study, road vulnerability is calculated using a network’s global efficiency measures to identify locations of high and low road vulnerability. Using the between centrality as a measure of road load, the spatiotemporal patterns of road network cascading failure during a real rainstorm are analyzed. The spatial association between road network vulnerability and cascading failure is then investigated. It has been determined that 90.09% of the roads in Zhengzhou city have a vulnerability of less than one, indicating a substantial degree of spatial heterogeneity. The vulnerability of roads adjacent to the city ring roads and city center is often lower, which has a significant impact on the global network’s efficiency. In contrast, road vulnerability is greater in areas located on the urban periphery, which has little effect on the global network’s efficiency. Five hot spots and three cold spots of road vulnerability are identified by using spatial autocorrelation analysis. The cascading failure of a road network exhibits varied associational characteristics in distinct clusters of road vulnerability. Road cascading failure has a very minor influence on the network in hot spots but is more likely to cause widespread traffic congestion or disruption in cold spots. These findings can help stakeholders adopt more targeted policies and strategies in urban planning and disaster emergency management to build more resilient cities and promote sustainable urban development.

Objectives: The objectives of this study were to distinguish the role of men who have sex with men (MSM) with or without syphilis testing in HIV-1 transmission and to provide molecular evidence of syphilis testing as a proxy marker for identifying the subgroup of MSM.Methods: HIV-1 transmission clusters were constructed by HIV-TRACE and Cluster Picker using HIV-1 pol sequences from 729 newly diagnosed HIV-infected MSM from 2008 to 2012 in Guangzhou, China. The role of MSM in HIV-1 transmission networks was determined by a node influence measurement and centrality analysis. The association between syphilis testing and factors related to HIV-1 transmission and antiretroviral treatment (ART) were analyzed by the Cox regression model.Results: Among HIV-infected MSM, 56.7% did not test for syphilis at the time of HIV-1 diagnosis. MSM without syphilis testing was a specific subgroup of MSM with a larger closeness centrality and clustering coefficient than the recipients of syphilis testing (P < 0.001), indicating their central position in the HIV-1 transmission networks. The median degree and radiality within HIV-1 transmission networks as well as the median K-shell scores were also greater for MSM without syphilis testing (P < 0.001), suggesting their relatively greater contribution in transmitting HIV-1 than the receipts of syphilis testing. MSM with syphilis testing usually did not disclose their occupation or were more likely to be unemployed or to take non-skilled jobs, to have a history of sexually transmitted infections (STIs), and to be AIDS patients when diagnosed with HIV-1 infection (P < 0.05). Multivariable Cox regression analysis indicated that syphilis testing per se did not promote the engagement of ART (P = 0.233) or affect the speed of CD4+ T cell count recovery after treatment (P = 0.256).Conclusions: Our study identifies syphilis testing as a proxy marker of a specific subgroup of HIV-infected MSM who refuse syphilis testing during HIV-1 diagnosis with an important role in HIV-1 transmission. Specific prevention and intervention targeting MSM without syphilis testing during HIV-1 care are urgently needed.

Abstract Background Silk fibroin hydrogel, derived from Bombyx mori cocoons, has been shown to have potential effects on wound healing due to its excellent biocompatibility and less immunogenic and biodegradable properties. Many studies suggest silk fibroin as a promising material of wound dressing and it can support the adhesion and proliferation of a variety of human cells in vitro. However, lack of translational evidence has hampered its clinical applications for skin repair. Herein, a heparin-immobilized fibroin hydrogel was fabricated to deliver FGF1 (human acidic fibroblast growth factor 1) on top of wound in rats with full-thickness skin excision by performing comprehensive preclinical studies to fully evaluate its safety and effectiveness. The wound-healing efficiency of developed fibroin hydrogels was evaluated in full-thickness wound model of rats, compared with the chitosan used clinically. Results The water absorption, swelling ratio, accumulative FGF1 releasing rate and biodegradation ratio of fabricated hydrogels were measured. The regenerated fibroin hydrogels with good water uptake properties rapidly swelled to a 17.3-fold maximum swelling behavior over 12 h and a total amount of 40.48 ± 1.28% hydrogels was lost within 15 days. Furthermore, accumulative releasing data suggested that heparinized hydrogels possessed effective release behavior of FGF1. Then full-thickness skin excision was created in rats and left untreated or covered with heparinized fibroin hydrogels-immobilized recombinant human FGF1. The histological evaluation using hematoxylin and eosin (HE) and Masson’s trichrome (MT) staining was performed to observe the dermic formation and collagen deposition on the wound-healing site. To evaluate the wound-healing mechanisms induced by fibroin hydrogel treatment, wound-healing scratch and cell proliferation assay were performed. it was found that both fibroin hydrogels and FGF1 can facilitate the migration of fibroblast L929 cells proliferation and migration. Conclusion This study provides systematic preclinical evidence that the silk fibroin promotes wound healing as a wound-healing dressing, thereby establishing a foundation toward its further application for new treatment options of wound repair and regeneration.

Abstract Background Given the widespread use of the Internet among men who have sex with men (MSM) and high risk of Internet-facilitated sexual behaviors, Internet-based interventions to reduce sexual risk are urgently needed. Methods We recruited 1,100 participants from online and randomly assigned to two groups. One group received online HIV intervention services. Online HIV intervention was developed through mix-method formative research, measures included scenarios experiencing intervention and HIV information dissemination. Self-reported condomless anal sex with a male in the past three months was measured to evaluate the intervention effect. Result Of the 1,100 participants, the majority were aged between 21 and 30 years old (62%), had a college degree or higher (80%), were single (88%), and self-identified as homosexual (78%). The estimated risk difference of condomless sex with a male in the past three months between groups was 9.3% (95% confidence interval (CI): 1.1, 17.5%). Using multiple imputations intention-to-treat, the estimated risk difference was 8.9% (95%CI: 1.2, 16.6%). Modification effects were found between intervention and characteristics including: educational attainment (p = 0.012), marital status (p = 0.005) and awareness of AIDS-related knowledge (p = 0.010). Conclusion Internet appears to be a promising approach to disseminate HIV prevention amongst MSM. Interactive online intervention appeals to MSM and poses a great potential for reducing HIV risky behavior. Trial registration ChiCTR1800014260 (retrospectively registered 2 Jan, 2018).

In this paper, the multiple hyperbolas method is proposed for characterizing the beam quality of unstable laser beams. Based on the traditional beam quality analyzer equipment, the proposed method captures multiple intensity images at every measurement positions. Afterward, three different hyperbolas are fitted according to the widths of laser intensities. With the fitted hyperbolas, three parameters, which include the average beam quality factor (Maver2) and variation factors (νpos, νneg), are determined. With the proposed method and determined parameters, the beam quality of unstable laser beams can be characterized more accurately and completely. The limitation of the traditional ISO standard-based method for characterizing unstable laser beams is also presented. In addition, the simulation and experimental results agree well with each other, indicating that the new method and determined parameters are appropriate for characterizing unstable laser beams. Keywords: Laser beam delivery and diagnostics, Laser characteristic, Laser beam quality, Unstable laser beams

Security issues such as natural disasters and terrorist attacks have attracted increasing global concern and attention. How to effectively detect security events has become worrisome to countries worldwide. Advances in mobile Internet technology have led to hundreds of millions of users using social media daily to post microblogs, text messages and multimedia information, generating enormous amounts of social media data that reflect people's social behaviors. Studies have proven that the timely intelligence can be extracted from these data. In particular, geosocial media when combined with location information can be used as a proxy for security event detection and security situational awareness. This paper provides a synopsis of the geosocial media data and the related processing/analysis methods used for detecting security events, and summarizes the general framework of security-related analyses based on geosocial media. Four major categories of analysis methods and application cases, including natural language processing, social network analysis, location inference and geospatial analysis, and image or video understanding, are discussed in detail. The paper concludes with possible future directions and areas of research that could be addressed and investigated. We hope to provide a clarion call to the scientists, practitioners, and other stakeholders to enhance the capabilities and accuracy of security events detection and security situational awareness and assessment using geosocial media.

Land use is used to reflect the expression of human activities in space, and land use classification is a way to obtain accurate land use information. Obtaining high-precision land use classification from remote sensing images remains a significant challenge. Traditional machine learning methods and image semantic segmentation models are unable to make full use of the spatial and contextual information of images. This results in land use classification that does not meet high-precision requirements. In order to improve the accuracy of land use classification, we propose a land use classification model, called DADNet-CRFs, that integrates an attention mechanism and conditional random fields (CRFs). The model is divided into two modules: the Dual Attention Dense Network (DADNet) and CRFs. First, the convolution method in the UNet network is modified to Dense Convolution, and the band-hole pyramid pooling module, spatial location attention mechanism module, and channel attention mechanism module are fused at appropriate locations in the network, which together form DADNet. Second, the DADNet segmentation results are used as a priori conditions to guide the training of CRFs. The model is tested with the GID dataset, and the results show that the overall accuracy of land use classification obtained with this model is 7.36% and 1.61% higher than FCN-8s and BiSeNet in classification accuracy, 11.95% and 1.81% higher in MIoU accuracy, and with a 9.35% and 2.07% higher kappa coefficient, respectively. The proposed DADNet-CRFs model can fully use the spatial and contextual semantic information of high-resolution remote sensing images, and it effectively improves the accuracy of land use classification. The model can serve as a highly accurate automatic classification tool for land use classification and mapping high-resolution images.

Buildings are important entity objects of cities, and the classification of building shapes plays an indispensable role in the cognition and planning of the urban structure. In recent years, some deep learning methods have been proposed for recognizing the shapes of building footprints in modern electronic maps. Furthermore, their performance depends on enough labeled samples for each class of building footprints. However, it is impractical to label enough samples for each type of building footprint shapes. Therefore, the deep learning methods using few labeled samples are more preferable to recognize and classify the building footprint shapes. In this paper, we propose a relation network based method for the recognization of building footprint shapes with few labeled samples. Relation network, composed of embedding module and relation module, is a metric based few-shot method which aims to learn a generalized metric function and predict the types of the new samples according to their relation with the prototypes of these few labeled samples. To better extract the shape features of the building footprints in the form of vector polygons, we have taken the TriangleConv embedding module to act as the embedding module of the relation network. We validate the effectiveness of our method based on a building footprint dataset with 10 typical shapes and compare it with three classical few-shot learning methods in accuracy. The results show that our method performs better for the classification of building footprint shapes with few labeled samples. For example, the accuracy reached 89.40% for the 2-way 5-shot classification task where there are only two classes of samples in the task and five labeled samples for each class.

Drought is a devastating environmental constraint affecting the agronomic production of barley. To facilitate the breeding process, abundant germplasm resources and reliable evaluation systems to identify the true drought-tolerant barley genotypes are needed. In this study, 237 cultivated and 190 wild barley genotypes, originating from 28 countries, were screened for drought tolerance under the conditions of both water deficit and polyethylene glycol (PEG)-simulated drought at seedling stage. Drought stress significantly reduced the plant growth of all barley genotypes, but no significant difference in drought-induced reduction in the performance of barley seedlings was observed under these two drought conditions. Both cultivated and wild barley subspecies displayed considerable genotypic variability in drought tolerance, which underpinned the identification of 18 genotypes contrasting in drought tolerance. A comparative analysis of drought effects on biomass, water relation, photosynthesis, and osmotic adjustment was undertaken using these contrasting barley genotypes, in order to verify the reliability of the screening and to obtain the credible traits as screening criteria of drought tolerance in barley. As expected, the selected drought-tolerant genotypes showed much less reduction in shoot biomass than drought-sensitive ones under water deficit, which was significantly positively correlated with the results of large-scale screening, confirming the reliability of the screening for drought tolerance under two drought conditions in this study. Likewise, the traits of water relation, photosynthetic activity, and osmotic adjustment differed greatly between the contrasting genotypes under water deficit stress, and they were highly correlated to the growth of barley seedlings, suggesting the potential of them to be the selection criteria for drought tolerance. The analysis of the variable importance of these traits in drought tolerance indicated that sap osmolality and relative water content in the youngest fully-expanded leaf are the suitable selection criteria of screening for drought tolerance in barley at seedling stage.

In barley (Hordeum vulgare L.) breeding, heading date is one of the most important agricultural traits that is essential for the completion of its life cycle. Certain endogenous and environmental factors regulate floral transition, morphing the complex genetic mechanism of the heading phase, which could serve as a premise of orchestration for improved yields. To elaborate the network of genetic and environmental signals, a hydroponic experiment was carried out using two spring (i.e., DM65 and DM70) and two winter barley genotypes (i.e., DM269 and DM385). Our results confirmed that the vernalized environment produced a substantial reduction in plant height, biomass and photosynthetic activity compared with the control plants. A noticeable increase in oxidative stress was exhibited by DM65 and DM70 plants compared with their respective controls at 20 °C, while no significant difference was observed for any genotype grown in the greenhouse (25 °C). Simultaneously, increased antioxidant enzyme activity in winter barley genotypes showed a defensive mechanism under vernalized conditions (4 °C). Furthermore, the expression of key regulatory flowering genes revealed that the vernalization gene (HvVRN1) is the key regulator of floral induction after cold exposure, whereas Photoperiod Response Locus 1 (HvPpd-H1) had significantly higher expression under greenhouse conditions, along with Phytochrome C (HvPHY-C), validating their involvement as upstream heading time regulators. These findings contribute to enriching the study of environmental signals that substantially modulate the complex mechanism of barley heading date.

Abstract Background The interest has been increasing on the phenolic compounds in plants because of their nutritive function as food and the roles regulating plant growth. However, their underlying genetic mechanism in barley is still not clear. Results A genome-wide association study (GWAS) was conducted for total phenolic content (TPC), total flavonoid content (FLC) and antioxidant activity (AOA) in 67 cultivated and 156 Tibetan wild barley genotypes. Most markers associated with phenolic content were different in cultivated and wild barleys. The markers bPb-0572 and bPb-4531 were identified as the major QTLs controlling phenolic compounds in Tibetan wild barley. Moreover, the marker bPb-4531 was co-located with the UDP- glycosyltransferase gene (HvUGT), which is a homolog to Arabidopsis UGTs and involved in biosynthesis of flavonoid glycosides . Conclusions GWAS is an efficient tool for exploring the genetic architecture of phenolic compounds in the cultivated and Tibetan wild barleys. The DArT markers applied in this study can be used in barley breeding for developing new barley cultivars with higher phenolics content. The candidate gene (HvUGT) provides a potential route for deep understanding of the molecular mechanism of flavonoid synthesis.

Urban vitality is a key indicator for measuring urban development. This topic has been trending in urban planning and sustainable development, and significant progress has been made in measuring single indicators of urban vitality based on parcel or block units. With the continuous development of smart sensing technology, multisource urban data are becoming increasingly abundant. The application of such data to measure the multidimensional urban vitality of street space, reflecting multiple functions of an urban space, can significantly improve the accuracy of urban vitality analyses and promote the construction of people-oriented healthy cities. In this study, streets were taken as the analysis unit, and multisource data such as the trajectories of taxies and shared bicycles, user reviews and cultural facility points of interest (POIs) in Chengdu, a city in southwestern China, were used to identify spatial patterns of urban vitality on streets across social, economic and cultural dimensions. The correlation between the built environment factors and the multidimensional urban vitality on the street was analyzed using a multiple regression model. The spatial distribution of the different dimensions of urban vitality of the street space in Chengdu varies to a certain extent. It is common for areas with high social vitality to have production and life centers nearby. High economic vitality centers are typically found along busy streets with a high concentration of businesses. Areas with high cultural vitality centers tend to be concentrated on the city’s central streets. Land use, transportation, external environment, population and employment are all closely linked to urban vitality on streets. The crowd counting and POI density have the greatest impact on multidimensional urban vitality. The crowd and the level of service facilities profoundly affect social interaction, trade activities and cultural communication. The goodness of fit (R2) of the regression models for social, economic and cultural vitality are 0.590, 0.423 and 0.409, respectively. Using multisource urban data, our findings can help stakeholders better understand the spatial patterns and influencing factors of multidimensional urban vitality on streets and provide sustainable urban planning and development strategies for the future.

The classification and recognition of the shapes of buildings in map space play an important role in spatial cognition, cartographic generalization, and map updating. As buildings in map space are often represented as the vector data, research was conducted to learn the feature representations of the buildings and recognize their shapes based on graph neural networks. Due to the principles of graph neural networks, it is necessary to construct a graph to represent the adjacency relationships between the points (i.e., the vertices of the polygons shaping the buildings), and extract a list of geometric features for each point. This paper proposes a deep point convolutional network to recognize building shapes, which executes the convolution directly on the points of the buildings without constructing the graphs and extracting the geometric features of the points. A new convolution operator named TriangleConv was designed to learn the feature representations of each point by aggregating the features of the point and the local triangle constructed by the point and its two adjacency points. The proposed method was evaluated and compared with related methods based on a dataset consisting of 5010 vector buildings. In terms of accuracy, macro-precision, macro-recall, and macro-F1, the results show that the proposed method has comparable performance with typical graph neural networks of GCN, GAT, and GraphSAGE, and point cloud neural networks of PointNet, PointNet++, and DGCNN in the task of recognizing and classifying building shapes in map space.

Accurately identifying and delineating urban boundaries are the premise for and foundation of the control of disorderly urban sprawl, which is helpful for us to accurately grasp the scale and form of cities, optimize the internal spatial structure and pattern of cities, and guide the expansion of urban spaces in the future. At present, the concept and delineation of urban boundaries do not follow a unified method or standard. However, many scholars have made use of multi-source remote sensing images of various scales and social auxiliary data such as point of interest (POI) data to achieve large-scale, high-resolution, and high-precision land cover mapping and impermeable water surface mapping. The accuracy of small- and medium-scale urban boundary mapping has not been improved to an obvious extent. This study uses multi-temporal Sentinel-2 high-resolution images and POI data that can reflect detailed features of human activities to extract multi-dimensional features and use random forests and mathematical morphology to map the urban boundaries of the city of Zhengzhou. The research results show that: (1) the urban construction land extraction model established with multi-dimensional features has a great improvement in accuracy; (2) when the training sample accounts for 65% of the sample data set, the urban construction land extraction model has the highest accuracy, reaching 96.25%, and the Kappa coefficient is 0.93; (3) the optimized boundary of structural elements with a size of 13 × 13 is selected, which is in good agreement in terms of scope and location with the boundary of FROM-GLC10 (Zhengzhou) and visual interpretations. The results from the urban boundary delineation in this paper can be used as an important database for detailed basic land use mapping within cities. Moreover, the method in this paper has some reference value for other cities in terms of delineating urban boundaries.

In this article, the characteristics of the wave energy converter are considered and a novel dynamic controller (NDC) for a permanent magnet synchronous generator (PMSG) is proposed for Wells turbine applications. The proposed NDC includes a recursive cerebellum model articulation controller (RCMAC) with a grey predictor and innovative particle swarm optimization (IPSO). IPSO is developed to adjust the learning speed and improve learning capability. Based on the supervised learning method, online adjustment law of RCMAC parameters is derived to ensure the system’s stability. The NDC scheme is designed to maintain a supply−demand balance between intermittent power generation and grid power supply. The proposed NDC exhibits an improved power regulation and dynamic performance of the wave energy system under various operation conditions. Furthermore, better results are obtained when the RCMAC is used with the grey predictive model method.

A soil erosion model is used to evaluate the conditions of soil erosion and guide agricultural production. Recently, high spatial resolution data have been collected in new ways, such as three-dimensional laser scanning, providing the foundation for refined soil erosion modelling. However, serial computing cannot fully meet the computational requirements of massive data sets. Therefore, it is necessary to perform soil erosion modelling under a parallel computing framework. This paper focuses on a parallel computing framework for soil erosion modelling based on the Hadoop platform. The framework includes three layers: the methodology, algorithm, and application layers. In the methodology layer, two types of parallel strategies for data splitting are defined as row-oriented and sub-basin-oriented methods. The algorithms for six parallel calculation operators for local, focal and zonal computing tasks are designed in detail. These operators can be called to calculate the model factors and perform model calculations. We defined the key-value data structure of GeoCSV format for vector, row-based and cell-based rasters as the inputs for the algorithms. A geoprocessing toolbox is developed and integrated with the geographic information system (GIS) platform in the application layer. The performance of the framework is examined by taking the Gushanchuan basin as an example. The results show that the framework can perform calculations involving large data sets with high computational efficiency and GIS integration. This approach is easy to extend and use and provides essential support for applying high-precision data to refine soil erosion modelling.

Wormhole attack is one of the severe threats to wireless sensor and ad hoc networks. Most of the existing countermeasures either require specialized hardware or demand high network overheads in order to capture the specific symptoms induced by the wormholes, which in result limits their applicability. In this paper, we exploit an inevitable symptom of wormholes and present Pworm, a passive wormhole detection and localization system based upon the key observation that a large amount of network traffic will be attracted by the wormholes. The proposed scheme is passive, real-time, and efficient against both active and passive wormholes. Our approach silently observes the variations in network topology to infer the wormhole existence and solely relies on network routing information. It does not necessitate specialized hardware or poses rigorous assumptions on network features. We evaluate our scheme through extensive simulations of 100 to 800 nodes for various network scales and show that Pworm is well suited for false alarms, scalability, and time delay in terms of activation as well as detection latencies.

INTRODUCTION: Previous studies have reported a possibly increasing HIV prevalence among men who have sex with men (MSM) in China. However there have been limited systematic analyses of existing surveillance data to learn the trend of HIV prevalence and factors driving the trend. The aims of this study were to examine the trend of HIV prevalence among MSM in Guangzhou and to explore the role of unprotected anal intercourse (UAI) in the trend. METHODS: Snow-ball sampling was applied in the subject recruitment for the annual serological and behavioral surveys among MSM from 2008 to 2013. Data collected in the behavioral survey include demographic information, HIV related sexual behavior with men and women, access to HIV prevention services, and symptoms of sexually transmitted infections. Chi-square test was used to analyze the trend of HIV prevalence. Multivariate logistic regression was conducted to test the factors associated with HIV infection. RESULTS: HIV prevalence increased significantly from 5.0% in 2008 to 11.4% in 2013 while syphilis prevalence decreased from 17.4% to 3.3% in the same period. UAI rates were high and stable in every single year, ranging from 54.5% to 62.0%. Those who were having UAI (OR = 1.80, 95% confidence interval (CI): 1.26-2.58), being migrants, having more than 10 partners, and infected with syphilis had higher risk for HIV infection. CONCLUSIONS: HIV epidemic is expanding in Guangzhou. The persistently high UAI may have played a major role in the increasing trend of HIV prevalence. Targeted prevention program should be conducted among MSM who are migrants, low educational level, syphilis infected, or having multiple partners to encourage HIV test and change UAI behavior. The general high UAI calls for tailored intervention program to promote healthy culture and form a safe sex social norm in the MSM community.

The general form of model-free control law is introduced, and its convergence is analyzed. Firstly, the necessity to improve the basic form of model free control law is explained, and the functional combination method as the approach of improvement is presented. Then, a series of sufficient conditions of convergence are given. The analysis denotes that these conditions can be satisfied easily in the engineering practice.