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Wildfire is one of the main hazards affecting large areas and causes great damage all over the world, and the rapid development of the wildland-urban interface (WUI) increases the threat of wildfires that have ecological, social, and economic consequences. As one of the most widely used methods for tracking fire, remote sensing can provide valuable information about fires, but it is not always available, and needs to be supplemented by data from other sources. Social media is an emerging but underutilized data source for emergency management, contains a wealth of disaster information, and reflects the public's real-time witness and feedback to fires. In this paper, we propose a fusion framework of multi-source data analysis, including social media data and remote sensing data, cellphone signaling data, terrain data, and meteorological data to track WUI fires. Using semantic web technology, the framework has been implemented as a Knowledge Base Service and runs on top of WUIFire ontology. WUIFire ontology represents WUI fire–related knowledge and consists of three modules: system, monitoring, and spread, and tracks wildfires happening in WUIs. It provides a basis for tracking and analyzing a WUI fire by fusing multi-source data. To showcase the utility of our approach in a real-world scenario, we take the fire in the Yaji Mountain Scenic Area, Beijing, China, in 2019 as a case study. With object information identified from remote sensing, fire situation information extracted from Weibo, and fire perimeters constructed through fire spread simulation, a knowledge graph is constructed and an analysis using a semantic query is carried out to realize situational awareness and determine countermeasures. The experimental results demonstrate the benefits of using a semantically improved multi-source data fusion framework for tracking WUI fire. [ABSTRACT FROM AUTHOR]

Objectives: By analyzing the distribution of existing and newly proposed staging imaging features in pT1–3 and pT4a tumors, we searched for a salient feature and validated its diagnostic performance. Methods: Preoperative multiphase contrast-enhanced CT images of the training cohort were retrospectively collected at three centers from January 2016 to December 2017. We used the chi-square test to analyze the distribution of several stage-related imaging features in pT1–3 and pT4a tumors, including small arteriole sign (SAS), outer edge of the intestine, tumor invasion range, and peritumoral adipose tissue. Preoperative multiphase contrast-enhanced CT images of the validation cohort were retrospectively collected at Beijing Cancer Hospital from January 2018 to December 2018. The diagnostic performance of the selected imaging feature, including accuracy, sensitivity, and specificity, was validated and compared with the conventional clinical tumor stage (cT) by the McNemar test. Results: In the training cohort, a total of 268 patients were enrolled, and only SAS was significantly different between pT1–3 and pT4a tumors. The accuracy, sensitivity, and specificity of the SAS and conventional cT in differentiating T1–3 and T4a tumors were 94.4%, 81.6%, and 97.3% and 53.7%, 32.7%, and 58.4%, respectively (all p < 0.001). In the validation cohort, a total of 135 patients were collected. The accuracy, sensitivity, and specificity of the SAS and the conventional cT were 93.3%, 76.2%, and 96.5% and 62.2%, 38.1%, and 66.7%, respectively (p < 0.001, p = 0.021, p < 0.001). Conclusion: Small arteriole sign positivity, an indirect imaging feature of serosa invasion, may improve the accuracy of identifying T4a colon cancer. Clinical relevance statement: Small arteriole sign helps to distinguish T1–3 and T4a colon cancer and further improves the accuracy of preoperative CT staging of colon cancer. Key Points: • The accuracy of preoperative CT staging of colon cancer is not ideal, especially for T4a tumors. • Small arteriole sign (SAS) is a newly defined imaging feature that shows the appearance of tumor-supplying arterioles at the site where they penetrate the intestine wall. • SAS is an indirect imaging marker of tumor invasion into the serosa with a great value in distinguishing between T1–3 and T4a colon cancer. [ABSTRACT FROM AUTHOR]

Background: Identifying the key factors that underlie complex traits during domestication is a great challenge for evolutionary and biological studies. In addition to the protein-coding region differences caused by variants, a large number of variants are located in the noncoding regions containing multiple types of regulatory elements. However, the roles of accumulated variants in gene regulatory elements during duck domestication and economic trait improvement are poorly understood. Results: We constructed a genomics, transcriptomics, and epigenomics map of the duck genome and assessed the evolutionary forces that have been in play across the whole genome during domestication. In total, 304 (42.94%) gene promoters have been specifically selected in Pekin duck among all selected genes. Joint multi-omics analysis reveals that 218 genes (72.01%) with selected promoters are located in open and active chromatin, and 267 genes (87.83%) with selected promoters were highly and differentially expressed in domestic trait-related tissues. One important candidate gene ELOVL3, with a strong signature of differentiation on the core promoter region, is known to regulate fatty acid elongation. Functional experiments showed that the nearly fixed variants in the top selected ELOVL3 promoter in Pekin duck decreased binding ability with HLF and increased gene expression, with the overexpression of ELOVL3 able to increase lipid deposition and unsaturated fatty acid enrichment. Conclusions: This study presents genome resequencing, RNA-Seq, Hi-C, and ATAC-Seq data of mallard and Pekin duck, showing that selection of the gene promoter region plays an important role in gene expression and phenotypic changes during domestication and highlights that the variants of the ELOVL3 promoter may have multiple effects on fat and long-chain fatty acid content in ducks. [ABSTRACT FROM AUTHOR]

Objectives: To investigate potential predictors of treatment response in primary Sjögren's syndrome (pSS) patients with severe immune thrombocytopenia (ITP), with a focus on bone marrow megakaryocyte (MK) count. Methods: This case–control study included patients with pSS and severe ITP who were admitted to Peking Union Medical College Hospital and met the 2002 AECG or 2016 American College of Rheumatology / European League Against Rheumatism criteria for SS. Patients who had overlap other connective tissue diseases and with thrombocytopenia that could be explained by other causes were excluded. Severe ITP was defined as platelet count <20 × 109/L. Response was evaluated at 3 months after treatment. Results: Sixty‐eight eligible patients were included: 34 (50%) achieved complete remission (CR), 18 (26%) partial remission (PR) and 16 (24%) were non‐responders (NRs). Fewer infections were found in the CR group (24%) than in the PR (50%) and NR (56%) groups (P = 0.04). The MK count (CR 32 vs PR 36 vs NR 4 per slide, P < 0.001) in the NR group was significantly lower than in the other groups. MK count >6.5 per slide predicted good treatment response, with 85.7% sensitivity, 88.1% specificity and 0.866 area under the curve. Logistic regression indicated that patients with more MKs were more likely to respond to immunotherapy (crude odds ratio [OR] 1.45, 95% CI 1.2–2.0, adjusted OR 1.68, 95% CI 1.2–2.7). Conclusions: MK count predicted response to immunosuppressive treatment in pSS patients with severe ITP. These patients are recommended to have bone marrow aspiration before treatment initiation. Clinicians should be aware of screening for infections during clinical practice. [ABSTRACT FROM AUTHOR]

Objective: To assess the short‐term and skill‐retention effects of a structural simulation curriculum for the repair of obstetrical anal sphincter injuries (OASIS). Methods: This prepost experimental study recruited 31 obstetrics and gynecology residents from Peking Union Medical College Hospital. OASIS repair skill evaluations (at all timepoints) comprised a task‐specific checklist (TSC), global rating scale (GRS), and pass/fail grade. A beef‐tongue model was adopted in the simulation curriculum. After baseline testing, residents completed a structured 1‐h workshop. Two weeks later, a second test was performed, followed by a one‐to‐one teaching workshop, with the proper completion of a checklist as the end‐point. Three months later, residents completed a third test. Results: The overall pass rate at baseline was 16.1%, with higher GRS scores (p = 0.035) in senior residents. Additionally, previewing the procedure before class and a history of OASIS repair observation were associated with higher TSC and GRS scores. Significant skill improvement was observed in the second and third tests, with pass rates of 96.8% and 93.5% respectively. Both TSC and GRS scores were improved compared with baseline (p < 0.001). Conclusion: A structural simulation curriculum integrating deliberate practice under supervision improves OASIS repair competence and achieves satisfactory skill retention. Synopsis: Our simulation curriculum using a modified beef‐tongue model shows good short‐term and skill‐retention effects for the repair of obstetric anal sphincter injuries. [ABSTRACT FROM AUTHOR]

Air quality plays a vital role in people's health, and air quality forecasting can assist in decision making for government planning and sustainable development. In contrast, it is challenging to multi-step forecast accurately due to its complex and nonlinear caused by both temporal and spatial dimensions. Deep models, with their ability to model strong nonlinearities, have become the primary methods for air quality forecasting. However, because of the lack of mechanism-based analysis, uninterpretability forecasting makes decisions risky, especially when the government makes decisions. This paper proposes an interpretable variational Bayesian deep learning model with information self-screening for PM2.5 forecasting. Firstly, based on factors related to PM2.5 concentration, e.g., temperature, humidity, wind speed, spatial distribution, etc., an interpretable multivariate data screening structure for PM2.5 forecasting was established to catch as much helpful information as possible. Secondly, the self-screening layer was implanted in the deep learning network to optimize the selection of input variables. Further, following implantation of the screening layer, a variational Bayesian gated recurrent unit (GRU) network was constructed to overcome the complex distribution of PM2.5 and achieve accurate multi-step forecasting. The high accuracy of the proposed method is verified by PM2.5 data in Beijing, China, which provides an effective way, with multiple factors for PM2.5 forecasting determined using deep learning technology. [ABSTRACT FROM AUTHOR]

The environment and development are major issues of general concern. After much suffering from the harm of environmental pollution, human beings began to pay attention to environmental protection and started to carry out pollutant prediction research. A large number of air pollutant predictions have tried to predict pollutants by revealing their evolution patterns, emphasizing the fitting analysis of time series but ignoring the spatial transmission effect of adjacent areas, leading to low prediction accuracy. To solve this problem, we propose a time series prediction network with the self-optimization ability of a spatio-temporal graph neural network (BGGRU) to mine the changing pattern of the time series and the spatial propagation effect. The proposed network includes spatial and temporal modules. The spatial module uses a graph sampling and aggregation network (GraphSAGE) in order to extract the spatial information of the data. The temporal module uses a Bayesian graph gated recurrent unit (BGraphGRU), which applies a graph network to the gated recurrent unit (GRU) so as to fit the data's temporal information. In addition, this study used Bayesian optimization to solve the problem of the model's inaccuracy caused by inappropriate hyperparameters of the model. The high accuracy of the proposed method was verified by the actual PM2.5 data of Beijing, China, which provided an effective method for predicting the PM2.5 concentration. [ABSTRACT FROM AUTHOR]

Multilane roads are a set of approximately parallel line segments representing the same road in large-scale vector maps. They must be extracted first in cartographic generalization. There are numerous multilane roads in the easily accessible OpenStreetMap (OSM) dataset. For this dataset, polygon-based methods have achieved state-of-the-art performance. However, traditional polygon-based methods usually rely on manually labeled data, which means they are time-consuming and labor-intensive. To address this problem, an unsupervised framework for extracting multilane roads is proposed in this study. Road segments were first grouped to form the road polygons. A set of shape descriptors was formulated to reduce the dimensions of individual road polygons into conceptual points. Next, dimensional shape descriptors were standardized using logarithmic standardization. The density peaks clustering (DPC) algorithm was employed to classify these points. Then, cluster tags were identified manually to recognize which clusters represent multilane polygons. Finally, post-processing learning from the concept of assimilation is proposed to fill holes and remove islands. Experiments were conducted to extract multilane roads with datasets from three cities: Wuhan, Beijing and Munich. The experimental results show that the proposed framework effectively extracted multilane roads without any labels with accuracy levels comparable to those of supervised methods. [ABSTRACT FROM AUTHOR]

Simple Summary: Lipid deposition in animals is closely related to lipid anabolism. In order to further explore how differences in different metabolic types regulate lipid deposition, we compared the growth performance and lipid droplet metabolism of fatty-type ducks and lean-type ducks. The results showed that fatty-type ducks showed a faster growth rate and more fat deposition in the early growth stage after feeding the same diet, and produced more lipoproteins in serum and deposited in adipose tissue. However, fewer triglycerides accumulated in the liver. We believe that this performance of fatty-type ducks is caused by the increased expression level of lipid droplet-related genes. The reasons for differences in lipid depositions between fatty-type (F-T) and lean-type (L-T) ducks remain unknown. The present study aimed to compare the growth performance, lipid deposition, and gene expression related to lipid droplet formation in F-T and L-T Pekin ducks. One-day-old, 140 each L-T and F-T male ducks were selected and distributed separately into 20 replicate cages. All ducks were fed commercial diets up to 35 d of age. F-T ducks had a higher average daily gain from 21 to 28 d of age. On 35-day-old, F-T ducks had higher serum levels of high- and low-density lipoprotein cholesterol, cholesterol, albumin, and hydroxybutyrate dehydrogenase activity than L-T ducks. F-T ducks had higher abdominal fat and subcutaneous fat percentages than those in L-T ducks. Liver histological examination showed that L-T ducks contained more lipid droplets in the liver, which gradually decreased with increasing age. The average adipocyte area and diameter of abdominal fat and subcutaneous fat in the F-T and L-T ducks increased with age and were higher in F-T ducks than those in L-T ducks. Furthermore, the gene expression of perilipin 1, perilipin 2, angiopoietin-like protein 4, adipose triglyceride lipase, alpha/beta-hydrolase domain-containing protein 5 (ABHD5), and serine/threonine kinase 17a in the liver, abdominal fat, and subcutaneous fat of F-T ducks was higher than that in L-T ducks, and it increased with age. Compared to L-T ducks, F-T ducks had higher expression of ABHD5 in the abdominal fat and subcutaneous fat and lower expression in the liver. Thus, F-T ducks displayed lower hepatic lipid deposition and a higher percentage of abdominal fat and subcutaneous fat, suggesting that F-T ducks had higher lipid storage capacity due to increased gene expression related to lipid droplets. [ABSTRACT FROM AUTHOR]

Wet markets serve as a cornerstone of food distribution in China but are increasingly being threatened by urban displacement. This study explores the various motivations for local governments in Sanya City and Beijing City to enact aggressive policies limiting wet markets, the dynamic nature of the governing process and the multifaceted impacts such governance has on the everyday practices of vendors and consumers. Drawing upon Foucault's notion of problematisation, this study found that wet markets have become representations of 'problems' such as insanitation and disorder, lowlands of economic revenue and 'low-skilled industry'. Specific governance is regularly entangled with multiple means of problematisation, shaped and conditioned by forces such as administrative capacity, policy intensity, market configuration, business activism and consumer demand, as well as the interrelationships among them. Current governance is attempting to 'correct' wet markets to desired forms, but ignores the holistic value they embed in urban life. Thus, this research suggests more inclusive governance and sustainable development with regards to wet markets. [ABSTRACT FROM AUTHOR]

Simple Summary: Enterocytozoon bieneusi is the most prevalent microsporidian species that can cause significant intestinal diseases in both humans and animals worldwide. This study investigated the overall E. bieneusi prevalence of 21.9% (47/215) in captive and free-ranging deer species in Beijing, China. Thirteen E. bieneusi genotypes including six known and seven novel genotypes were identified. These resources will provide the insights to understand the veterinary and public health and the transmission dynamics between animal environments and human ones. Enterocytozoon bieneusi is the most prevalent microsporidian species that can cause zoonotic diseases in humans and animals. Despite receiving increasing attention in relation to domestic animals, there has been limited information on the infection burden of E. bieneusi in cervids. Altogether, 215 fecal samples collected from four deer species in Beijing, China were examined by nested- Polymerase Chain Reaction (PCR)targeting the internal transcribed spacer (ITS) region. The overall prevalence of E. bieneusi in deer was 21.9% (47/215), with 30.0% (24/80) in Pere David's deer, 27.3% (15/55) in fallow deer, 12.5% (5/40) in sika deer, and 7.5% (3/40) in Chinese water deer. Thirteen E. bieneusi genotypes were identified, including six known (HLJD-V, MWC_d1, BEB6, CGC2, JLD-XV, and HND-I) and seven novel genotypes (BJED-I to BJED-V, BJFD, and BJCWD). A phylogenetic analysis showed that 38.3% of the isolates belonged to zoonotic Group 1. In addition, E. bieneusi infection was first detected in fallow deer and Chinese water deer, which could act as potential zoonotic reservoirs. Our findings suggest that E. bieneusi circulates in deer and might be of importance to public health. [ABSTRACT FROM AUTHOR]

Duck egg quality improvement is an essential target for Asian poultry breeding. In total, 15 RNA-Seq libraries (magnum, isthmus, and uterus at two different physiological states) were sequenced from 48 weeks old Pekin ducks. De novo assembly and annotation methods were utilized to generate new reference transcripts. Our results revealed that 1264 and 2517 genes were differentially expressed in magnum and uterus in the presence versus absence of an egg, respectively. We identified 1089 genes that were differentially expressed in isthmus compared to uterus (in both presence and absence of a calcifying egg). We observed that 11 common DEGs were detected in the egg white proteomes of 6 different bird species including domestic Chicken, Duck, Goose, Turkey, Quail, and Pigeon. On the other hand, only one of the top five most highly expressed genes in duck isthmus was in this category for the chicken isthmus (SPINK7). Among the large number of DEGs during eggshell formation in ducks, only 41 genes showed a similar differential expression pattern in both duck and chicken. By combining chicken QTL database, chicken oviduct transcriptome and egg proteome data for five bird species, we have obtained high-quality gene lists for egg formation. This is the first study to elucidate the transcriptomic changes in different duck oviduct segments during egg formation, and to integrate QTL, proteome and transcriptome data to probe the functional genes associated with albumen secretion and eggshell mineralization. • De novo assembly yielded 97,264 unigenes • We observed species-specific/common egg white related genes of 6 bird species • SPINK7 is potentially a new gene that is involved in some initial phase of biomineralization in avian eggshell formation • There are significant differences in eggshell phenotypes between chicken and duck eggs [ABSTRACT FROM AUTHOR]

Background: Researches indicate that epigenetics was involved in osteoarthritis (OA). The purpose of this study was to describe the alterations of DNA methylation in hip and knee OA by comparing DNA methylome of OA cartilage and non-OA samples and to identify novel genes and pathways associated with OA. Methods: We gained two expression profiling datasets (GSE73626 and GSE63695) from the GEO dataset. The RnBeads in R package was used to identify differentially methylated CpG sites. Genes that showed significant differences in DNA methylation between OA and normal control groups underwent functional annotation analysis using the online tool of GeneCodis. Furthermore, we used the Sequenom MassARRAY platform (CapitalBio, Beijing, China) to perform the quantitative methylation analysis. Results: A total of 249 hypermethylated sites and 96 hypomethylated sites were obtained from OA samples compared with normal control samples. Functional analysis of differentially methylated genes obtained that embryonic skeletal system morphogenesis, cartilage development, and skeletal system development may be involved in the pathogenesis of OA. Eight genes including HOXB3, HOXB4, HOXB6, HOXC4, HOXC10, HOXD3, TBX3, and TBX5 were identified as potential novel biomarkers for OA. Conclusion: Taken together, our study found different molecular characteristics between OA patients and normal controls. This may provide new clues to elucidate the pathogenesis of OA. Key Points • Embryonic skeletal system morphogenesis, cartilage development, skeletal system development may be involved in the pathogenesis of OA. • Eight genes are identified as potential novel markers for OA. • Our future in vivo molecular intervention experiments will extend our current findings. [ABSTRACT FROM AUTHOR]

• Microscopic and macroscopic properties of Beijing marble are investigated. • Statistical correlations among macroscopic parameters are studied. • An on-site quality control method in selection of replacing pieces is proposed. • Physico-mechanical properties of thirty-one types of marbles are compared. • New insights into weathering mechanisms from perspective of multi-factor coupling. Beijing marble has been used as a construction material for cultural heritage sites in Beijing area, China. The Forbidden City, the Temple of Heaven, the Summer Palace, and the Thirteen Ming Tombs are classified as UNESCO World Heritage sites. In this paper, detailed experimental and analytical investigations of two representative sub-types of Beijing marble are presented. Marble samples were collected from a historical quarry in Dashiwo County of Beijing's Fangshan District. Mineral and chemical constituents were investigated through petrographical observations, X-Ray Diffraction (XRD) analysis and X-Ray Fluorescence (XRF) analysis. Physical parameters (e.g., density, porosity, water absorption, pore size distribution, P-wave velocity (V P), seismic anisotropy (A VP), hardness, etc.) and mechanical parameters (i.e., uniaxial compressive strength (UCS) and Young's modulus (E)) were tested in accordance with British and Chinese standards. Correlations among tested parameters were also analyzed to better understand the internal relations among different properties and to aid in evaluating unattainable parameters during in-site heritage site assessments. To get a more comprehensive understanding of the marble's characteristics, we collected and analyzed those physico-mechanical data reported by previous researchers. Additionally, the weathering mechanisms and resistance of the marbles were discussed from different perspectives. The results of this study provide scientific data on the properties of Beijing dolomitic marble, which have practical use for weathering assessments and reconstruction of cultural heritage sites. Additionally, the results of this study provide a reliable reference for studying worldwide marbles with different geological origins. [ABSTRACT FROM AUTHOR]

In addition to many recent actions taken to reduce emissions from energy production, industry, and transportation, a new campaign substituting residential solid fuels with electricity or natural gas has been launched in Beijing, Tianjin, and 26 other municipalities in northern China, aiming at solving severe ambient air pollution in the region. Quantitative analysis shows that the campaign can accelerate residential energy transition significantly, and if the planned target can be achieved, more than 60% of households are projected to remove solid fuels by 2021, compared with fewer than 20% without the campaign. Emissions of major air pollutants will be reduced substantially. With 60% substitution realized, emission of primary PM2.5 and contribution to ambient PM2.5 concentration in 2021 are projected to be 30% and 41% of those without the campaign. With 60% substitution, average indoor PM2.5 concentrations in living rooms in winter are projected to be reduced from 209 (190 to 230) μg/m³ to 125 (99 to 150) μg/m³. The population-weighted PM2.5 concentrations can be reduced from 140 μg/m³ in 2014 to 78 μg/m³ or 61 μg/m³ in 2021 given that 60% or 100% substitution can be accomplished. Although the original focus of the campaign was to address ambient air quality, exposure reduction comes more from improved indoor air quality because ∼90% of daily exposure of the rural population is attributable to indoor air pollution. Women benefit more than men. [ABSTRACT FROM AUTHOR]

Abstract In this study, the corrosion behavior of X80 pipeline steel in the presence of Brevibacterium halotolerans (B. halotolerans) was investigated by surface analysis and electrochemical measurements. Results show that B. halotolerans can attach to the surface of X80 steel, and the entire surface is covered with B. halotolerans. The corrosion products induced by B. halotolerans were FeOOH, Fe 2 O 3 and FeSO 4. X80 steel corrosion was accelerated in the presence of B. halotolerans and was susceptible to pitting corrosion. The formation of pitting corrosion could be due that the B. halotolerans oxidization of elemental iron in X80 steel to either obtain electrons from the reduction of nitrate in the underlying biofilm or in the damaged corrosion product film. Highlights • B. halotolerans behaves a kind of NRB in soil corrosion MIC. • B. halotolerans can restore NO 3 − into NH 4 +. • B. halotolerans promotes pitting corrosion of X80 steel in soil environment. [ABSTRACT FROM AUTHOR]

Numerous studies have showed that landscape composition and configuration can significantly affect land surface temperature (LST). Most of these studies focus on the horizontal dimension of landscape structure. Few studies, however, have explored the effects of vertical dimension of urban landscape. This study aims to fill this gap. We focused on the residential landscapes in the central area of Beijing, and quantified the relationships between the vertical structure of buildings and LST. We delineated the boundaries of residential neighborhoods based on high resolution imagery, which were latterly used as the unit of statistical analysis. Building height, and proportional cover of buildings and vegetation were also mapped from high resolution imagery, with aid of digital maps. LST was retrieved from thermal band of TM imagery. We used Pearson correlation, partial correlation and ordinary least squares(OLS) regressions to quantify the relationships between these variables and LST. We found: 1) Land surface temperature varied greatly among residential neighborhoods, ranging from 53.5 °C to 37.0 °C, with a mean of 44.2 °C and a standard deviation of 2.4 °C. High-rise residential neighborhoods had the lowest LST, and mean LST decreased from low-rise to high-rise residential neighborhoods. 2) Building height, building density and vegetation coverage were all significantly correlated with LST. Building height and vegetation coverage has significantly negative effects on LST, but building density had a significantly positive one. 3) Among these variables, building height had greater impact on LST than the other two variables. These results have important implications for urban design and management. • Mean LST decreased from low-rise to high-rise residential neighborhoods. • Building height has significantly negative effects on LST in residential neighborhoods. • Building height had greater impacts on LST than building density and vegetation coverage. [ABSTRACT FROM AUTHOR]

Perceived destination image is rarely examined through the gaze of stakeholders other than visitors, in particular residents and tourism business operators. This hinders the comprehensive understanding of destination image and limits its practical implications for destination marketing and management. Therefore, this study proposes a multi-stakeholder approach to image evaluation to obtain a comprehensive understanding of the destination image and better inform destination planning and management. Taking Nanluoguxiang hutong tourism site in Beijing as an example, the image perceptions of residents, on-site business operators, and domestic and international tourists are compared. Questionnaire surveys with both types of tourists and semi-structured interviews with residents and business operators are the main research methods. Major between group differences are identified in the evaluation of the authenticity of this Beijing hutong area, its representation of traditional Beijing culture and whether or not it is a place in which to relax. Results demonstrate that visitors, residents and business operators share similar cognitive images of Nanluoguxiang as a traditional historical street and a special business street with Beijing character. However, the historical and cultural values of Nanluoguxiang are undervalued. Moreover, distinct differences exist between the actual motivations for visiting held by domestic and international tourists and their motivations as perceived by residents and business operators. Suggestions are made to better meet the expectations and desires of all stakeholder groups through the provision of participatory programmes and activities to enrich the visitor experience of hutongs and the hutong lifestyle while maintaining a boundary between tourists and residents' personal space to reduce unnecessary interruptions to residents' daily life. [ABSTRACT FROM AUTHOR]

In recent years rapid expansion of populations, disruption of ecological environments, and power shortages to areas of high population density in undeveloped areas have appeared in major cities in China. Well-planned population distribution in a city has become one of the key development strategies of urbanization in the country. Taking Beijing as a case-study and using 2010 as the base period, this study simulates city population size and distribution during 2011–2030 using the CA-MAS model. The results showed that (1) the unplanned layout of Beijing’s population is inefficient and will result in the slow agglomeration of populations into surrounding small towns, (2) the suburbanization of the population (while employment opportunities remain centralized) increases the stress of the city commuters, (3) the current policy guiding the distribution of residential and commercial areas is effective, accelerating the formation of small town clusters, which play a role in the city’s radiation and diffusion, contributing to reducing urban commuter stress, and (4) promoting the homogenization of public resources, planning the development of a multicenter urban area, and promoting mixed use (commercial and residential) zoning are the main measures recommended to strengthen the sustainability of Beijing’s urban development and to optimize spatial layout. [ABSTRACT FROM AUTHOR]

Air pollutants can cause serious harm to human health and a variety of respiratory diseases. This study aimed to explore the associations between air pollutants and outpatient visits for influenza-like illness (ILI) under urbanization process in the sub-center of Beijing. The data of ILI in sub-center of Beijing from April 1, 2014 to December 31, 2020 were obtained from Beijing Influenza Surveillance Network. A generalized additive Poisson model was applied to examine the associations between the concentrations of air pollutants and daily outpatient visits for ILI when controlling meteorological factors and holidays. A total of 322,559 patients with ILI were included. The results showed that in the early urbanization period, the effects of PM2.5, PM10, SO2, O3, and CO on lag0 day, and PM2.5, PM10, O3, and CO on lag1 day were not significant. In the later urbanization period, AQI and the concentrations of PM2.5, PM10, SO2, NO2 and CO on lag1 day were all significantly associated with an increased risk of outpatient visits for ILI, which increased by 0.34% (95%CI 0.23%, 0.45%), 0.42% (95%CI 0.29%, 0.56%), 0.44% (95%CI 0.33%, 0.55%), 0.36% (95%CI 0.24%, 0.49%), 0.91% (95%CI 0.62%, 1.21%) and 0.38% (95%CI 0.26%, 0.49%). The concentration of O3 on lag1 day was significantly associated with a decreased risk of outpatient visits for ILI, which decreased by 0.21% (95%CI 0.04%, 0.39%). We found that the urbanization process had significantly aggravated the impact of air pollutants on ILI outpatient visits. These findings expand the current knowledge of ILI outpatient visits correlated with air pollutants under urbanization process. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of daily activities on myopic refractive change and myopic onset in Chinese urban students. Methods: The Beijing Myopia Progression Study was a 3-year cohort study. Cycloplegic refraction and a daily activity questionnaire were assessed at baseline and at follow-up examinations. Refractive change was defined as the difference in cycloplegic spherical equivalent (SE) between the final follow-up and baseline. 386 students were initially enrolled in the baseline study. Results: At the final follow-up, 222 students (57.5 %) with completed refractive error and daily activity data were analyzed. These students spent 0.32 ± 2.33 h/day more on near work ( p = 0.04), and 0.21 ± 1.31 h/day less on outdoor leisure ( p = 0.02), than they did at baseline. In the multivariate analysis, the younger among the secondary students ( β = 0.06, p < 0.001), and those with more near work hours at baseline ( β = −0.028, p = 0.033), exhibited more myopic refractive change. However, myopic refractive change was not found to be significantly associated with near work hours in the primary students, or with time spent outdoors, in either school level. After stratifying the activity hours into quartile groups, students with a greater near work load at baseline (trend P = 0.03) exhibited a greater myopic refractive change and had a higher risk to develop myopia (hazard ratio, 95 % confidence interval: 5.19, 1.49-18.13), after adjusting for the confounders. However, no significant association was found related to outdoor activity. Conclusions: In this cohort, children with a greater near work load at baseline exhibited more myopic refractive change and were also more likely to develop myopia. The protective effect of outdoor activity on myopic refractive change was not observed. [ABSTRACT FROM AUTHOR]

Building load forecasting is critical for energy saving and carbon emission reduction, as building loads account for a rising percentage of energy consumption. Existing load forecasting methods only target a single building and do not consider the spatial characteristics of different building loads in an architectural complex, making it impossible to effectively forecast loads for all buildings in an architectural complex simultaneously. In this paper, considering the spatial correlation among building loads in an architectural complex, a novel short-term load forecasting method is proposed to improve the load forecasting accuracy for the architectural complex. First, Pearson correlation analysis is carried out to determine the key influencing factors of load, which are treated as multi-information. Then, to realize the load forecasting of all buildings in an architectural complex at the same time, a multi-information fusion model combined with a graph convolutional network and a long-short term memory network is proposed, and spatio-temporal attention modules are included to extract the dynamic spatio-temporal correlations of load. The performance of the proposed model is evaluated using actual load data from a public university in Beijing. When compared to other current methods, the experimental results show that the proposed model not only achieves the best results for architectural complex load forecasting (the largest MAPE is only 6.86%, the smallest R2 and Accuracy reach 0.87 and 0.85, respectively), but also maintains forecasting stability to some extent over a longer forecast period. The proposed method is a meaningful step towards achieving fast and accurate architectural complex load forecasting. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between maternal reproductive age and their children’ refractive error progression in Chinese urban students. Methods: The Beijing Myopia Progression Study was a three-year cohort investigation. Cycloplegic refraction of these students at both baseline and follow-up vision examinations, as well as non-cycloplegic refraction of their parents at baseline, were performed. Student’s refractive change was defined as the cycloplegic spherical equivalent (SE) of the right eye at the final follow-up minus the cycloplegic SE of the right eye at baseline. Results: At the final follow-up, 241 students (62.4%) were reexamined. 226 students (58.5%) with completed refractive data, as well as completed parental reproductive age data, were enrolled. The average paternal and maternal age increased from 29.4 years and 27.5 years in 1993–1994 to 32.6 years and 29.2 years in 2003–2004, respectively. In the multivariate analysis, students who were younger (β = 0.08 diopter/year/year, P<0.001), with more myopic refraction at baseline (β = 0.02 diopter/year/diopter, P = 0.01), and with older maternal reproductive age (β = -0.18 diopter/year/decade, P = 0.01), had more myopic refractive change. After stratifying the parental reproductive age into quartile groups, children with older maternal reproductive age (trend test: P = 0.04) had more myopic refractive change, after adjusting for the children's age, baseline refraction, maternal refraction, and near work time. However, no significant association between myopic refractive change and paternal reproductive age was found. Conclusions: In this cohort, children with older maternal reproductive age had more myopic refractive change. This new risk factor for myopia progression may partially explain the faster myopic progression found in the Chinese population in recent decades. [ABSTRACT FROM AUTHOR]

The WRF-Noah-urban canopy model (UCM) coupled modeling system is used to investigate the influence of urbanization on a typical frontal rainfall event that occurred in June 2008 over the greater Beijing metropolitan area (GBMA). The comparison between results of two experiments with and without the presence of urban areas suggests that more precipitation can be induced over and in the area downwind of Beijing because of the urbanization effects while less rainfall is found in the upwind region of central urban areas. The urbanization effects delay the onset of precipitation over Beijing but keep it sustained for a longer period with stronger rainfall intensity. The underlying urban surface not only retards the cold-frontal movement but also favors the development of a wet and unstable atmosphere. This explains why the precipitation can be sustained for a longer time with higher rainfall intensity over urban areas. From analyses of a density-current speed equation, it is found that the abrupt pressure jump during the frontal passage has a significant influence on the cold-frontal movement. A method derived from the surface pressure tendency equation is used to explore the mechanism of urban effects on the cold-frontal system. The cold advection is less intense in the experiment with urban land surface than in the experiment with urban areas replaced by cropland. Hence, the weaker-than-normal cold advection and subsequent smaller pressure jump during the frontal passage over the GBMA are the major mechanisms behind the urbanization effects, which lead to the retardation of the cold-frontal movement and late onset of precipitation over the GBMA. [ABSTRACT FROM AUTHOR]

The Great Beijing Metropolitan Area (GBMA), located in North China, is one of the most rapidly developing regions in the world. In this study, ensemble simulations are conducted to investigate the urban effects on a summertime heavy rainfall event in the GBMA. The Weather Research and Forecasting (WRF) model that couples with a single-layer Urban Canopy Model (UCM) is used for the ensemble simulation. Results show that the ensemble simulation with a realistic land-use representation of urban areas (i.e. control run) can well reproduce the spatial distribution and temporal variation of the rainfall event. The simulated total precipitation agrees well with observation. Compared with the sensitivity ensemble simulation, in which the urban area is replaced by cropland, the control run generates more precipitation over the southwest of Beijing, while less rainfall is found in the area to the northeast of Beijing. This result suggests that the underlying urban surface and urban canopy physics in the surface layer have remarkable impacts on precipitation. The stronger upward motion along with larger convergence and more moisture transportation caused by the urban dynamic and thermodynamic effects directly contribute to the differences in rainfall distribution between the control run and the sensitivity run. In addition, the urban effects are found to slow the cold front movement due to the intense warm air over the urban area, leading to a delayed occurrence of the peak rainfall. However, the slow-moving cold front over the urban area enhances the maximum precipitation intensity. The evolution of the rainfall pattern during the intensification period of the precipitation event is dependent on the movement of the cold front in both the control and sensitivity experiments, indicating that urban effects tend to modify the precipitation distribution and influence the temporal variation of the rainfall process. [ABSTRACT FROM AUTHOR]

Angel wing is a developmental wing deformity that can influence breeding and reproduction in the commercial duck industry. The nutrition foundation of angel wing trait was initially explored, but the genetic basic remains poorly understood. In this study, we identified candidate genes and single‐nucleotide polymorphisms (SNPs) associated with angel wing trait in Pekin ducks using a genome‐wide association study (GWAS) and selective sweep analysis. The GWAS results showed that nine SNPs across five chromosomes were significantly correlated with the angel wing trait. In total, 468 selection signals were shown between the angel wing ducks and normal ducks, and these signals harbored 154 genes, which were enriched in the nervous system and metabolism. This study provides the new insights into the genetic factors that may influence duck angel wing. [ABSTRACT FROM AUTHOR]

Bicycle-sharing is an eco-friendly transportation operating model in the context of "Internet Plus" and the sharing economy. It not only meets the short-distance travel needs of residents but has great significance for promoting the sustainable development of urban public transportation. However, a series of problems have appeared in the bicycle-sharing market, such as unreasonable resource allocation, low operating efficiency and management difficulties. Based on booking data and GPS trajectory data in Beijing of Mobike, this paper statistically analyzes the spatial and temporal distribution characteristics of residents' bicycle-sharing trips. Then, we construct a multi-factor influence model of bicycle-sharing demand based on a negative binomial regression and variable selection model, which quantifies a series of factors that influence bicycle-sharing trips, such as population and the regional economy, building land attributes, transportation accessibility, weather, and climatic conditions, etc. The results show that, firstly, there is a spatial imbalance in the distribution of bicycle-sharing demand among different districts in Beijing. Bicycle-sharing demand is mainly concentrated in the six core districts of the city, with more than 80% of all demand. We also find that the bicycle-sharing demand has different distribution characteristics on working days and nonworking days. Compared with nonworking days, residents' demand for bicycle-sharing on weekdays shows obvious peak periods in the morning, noon, and evening. Secondly, factors that have a major impact on the demand for bicycle-sharing include: per capita disposable income, pass facilities, parking lots etc. Among them, factors such as per capita disposable income, pass facilities, parking lots and bus/subway stations have a significant positive influence on bicycle-sharing demand. However, the number of functional zones such as airports, ports and marinas, tourist attraction and automobile sales has a significant negative influence. In addition, a comfortable temperature and good air quality encourage residents to use bicycle-sharing more for travel, while high humidity is not conducive to bicycle-sharing. We suggest that companies and related departments should jointly participate in the regulation and management of the bicycle-sharing industry, in various aspects such as bicycle scheduling, bicycle management and industry systems. In this way, cities can allocate bicycle-sharing resources reasonably and improve overall operating efficiency. The advantages of bicycle-sharing can be better used to promote the sustainable development of urban public transportation in the future. • The temporal distribution of bicycle-sharing demand is imbalanced, including between working and nonworking days, and between peak and off-peak periods of a day. • The spatial distribution of bicycle-sharing demand is imbalanced across the various administrative districts and functional zones. • Factors such as income and pass facilities have positive influence on bicycle-sharing demand, but the functional zones such as airports and ports have negative influence. • The use of bike-sharing is sensitive to the weather and air quality. [ABSTRACT FROM AUTHOR]

Aims To report the refractive error difference (RED) between parents and their children and the estimated single generational myopic shift in an urban area in China. Methods 395 children aged 6-17 years and their parents, who had been enrolled in the Beijing Myopia Progression Study were included. Cycloplegic and non-cycloplegic refraction of the children and parents were performed, respectively. RED was defined as the difference between the average parental spherical equivalent (SE) and the average SE of their children. Binomial fitted curves of RED were plotted as a function of the children's age. Generational myopic shift was defined as the estimated RED according to the prediction model at the age of 18 years. Results 395 families were enrolled. The RED was positively correlated with the children's age (rspearman=0.58, p<0.001). The RED (median (25th and 75th percentile)) was -1.88 (-3.23 to -1.00) dioptres (D) in children at 6.0-7.9 years of age, and it increased to 1.53 (-0.12 to 3.44) D in children at 16.0-17.9 years of age. The SE of the children approached the average SE of their parents at the age of 11 years. At the age of 18 years, the children's estimated myopic shift would be 1.94 D. Conclusions In this sample, children's refractive errors at the age of 11 years were already similar to their parents. Moreover, the estimated myopia in children at the age of 18 years would be up to 2.0 D higher than their parents. This remarkable single-generation myopic shift indicates that there are likely effects of environmental factors on myopia development in urban Chinese children. [ABSTRACT FROM AUTHOR]

Background: Herpes simplex virus (HSV) can cause encephalitis. Its infected cell polypeptide 47 (ICP47), encoded by immediate-early gene US12, promotes immune escape. ICP47 was modified in the clinically approved oncolytic HSV (oHSV) T-Vec. However, transcription regulatory sequence (TRS) and transcription regulatory factor (TRF) of HSV US12 are seldom reported. Methods: Previously, our laboratory isolated a new HSV strain named HSV-1-LXMW from a male patient with oral herpes in Beijing, China. Firstly, the genetic tree was used to analyze its genetic relationship. The US12 TRS and TRF in HSV-1-LXMW were found by using predictive software. Secondly, the further verification by the multi-sequence comparative analysis shown that the upstream DNA sequence of HSV US12 gene contained the conserved region. Finally, the results of literature search shown that the expression of transcription factors was related to the tissue affinity of HSV-1 and HSV-2, so as to increase the new understanding of the transcriptional regulation of HSV biology and oncolytic virus (OVs) therapy. Results: Here we reported the transcriptional regulation region sequence of our new HSV-1-LXMW, and its close relationship with HSV-1-CR38 and HSV-1-17. Importantly we identified eight different kinds of novel TRSs and TRFs of HSV US12 for the first time, and found they are conserved among HSV-1 (c-Rel, Elk-1, Pax-4), HSV-2 (Oct-1, CF2-II, E74A, StuAp) or both HSVs (HNF-4). The TRFs c-Rel and Oct-1 are biologically functional respectively in immune escape and viral replication during HSV infection. Conclusions: Our findings have important implication to HSV biology, infection, immunity and oHSVs. [ABSTRACT FROM AUTHOR]

To determine the role of the pandemic influenza A/H1N1 2009 (A/H1N1 2009pdm) in acute respiratory tract infections (ARTIs) and its impact on the epidemic of seasonal influenza viruses and other common respiratory viruses, nasal and throat swabs taken from 7,776 patients with suspected viral ARTIs from 2006 through 2010 in Beijing, China were screened by real-time PCR for influenza virus typing and subtyping and by multiplex or single PCR tests for other common respiratory viruses. We observed a distinctive dual peak pattern of influenza epidemic during the A/H1N1 2009pdm in Beijing, China, which was formed by the A/H1N1 2009pdm, and a subsequent influenza B epidemic in year 2009/2010. Our analysis also shows a small peak formed by a seasonal H3N2 epidemic prior to the A/H1N1 2009pdm peak. Parallel detection of multiple respiratory viruses shows that the epidemic of common respiratory viruses, except human rhinovirus, was delayed during the pandemic of the A/H1N1 2009pdm. The H1N1 2009pdm mainly caused upper respiratory tract infections in the sampled patients; patients infected with H1N1 2009pdm had a higher percentage of cough than those infected with seasonal influenza or other respiratory viruses. Our findings indicate that A/H1N1 2009pdm and other respiratory viruses except human rhinovirus could interfere with each other during their transmission between human beings. Understanding the mechanisms and effects of such interference is needed for effective control of future influenza epidemics. [ABSTRACT FROM AUTHOR]

Abstract: Comparative analysis is carried out on fresh water and reclaimed wastewater consumption in Beijing. As well, reclaimed wastewater consumption levels among various sectors are contrasted. Beijing has been integrating reclaimed wastewater as an important water resource since 2003 to solve the persistent problem of water shortage. Currently, reclaimed wastewater is exploited for scenic environment use, agricultural use and industrial use in the place of conventional water resources with higher percentage compared with other uses. Main factors affecting the promotion of wastewater reclamation in Beijing include water price, reclaimed wastewater quality, acceptability and local administrative orders. In order to stimulate the development of wastewater reclamation, local policies should take more rigorous water quality supervision into account, which will in turn improve social acceptability of reclaimed wastewater. Also, provision of reclaimed wastewater with guaranteed quality entails distribution of quality-differentiated reclaimed water to respective water consumers, and the resulted investment can be supported by public finances. [Copyright &y& Elsevier]

Forty-five sediment samples collected from Dongjiang River, which drains one of the most industrialized and urbanized regions in South China, were analyzed for 19 linear alkylbenzene (LAB) components. The sample dry weight-based concentrations of total LABs (ΣLAB) ranged from 1.5 to 410 ng/g. Comparison of the relative abundances of n-dodecylbenzenes (or C12-LABs) and internal to external ratio (I/E) values in riverine sediment, wastewater, and sediment samples from the outfalls of paper mills, as well as three brands of domestic detergents obtained from the present and previous studies, implicated the occurrence of untreated wastewater in the sampling sites. Levels of ΣLAB were significantly linear correlated with those of total organic carbon (TOC) but not with those of polycyclic aromatic hydrocarbons. Multiple linear regression integrated principal component analysis indicated that 56% of LABs in wastewater in the study area were treated, but the extent of degradation of LABs was low. Finally, it is proposed that ineffective law enforcement and loopholes in the current regulations for wastewater discharge account for the substantial amount (44%) of untreated wastewater discharged in the study region. Environ. Toxicol. Chem. 2012;31:724-730. © 2012 SETAC [ABSTRACT FROM AUTHOR]

Abstract: The compact pulsed neutron source can play an important role in the research, education, user training, and development of the advanced neutron scattering instruments. The materials for the target, moderator, reflector (TMR) and their configurations must be optimized to get the optimal yield of neutrons with energy in the range of 0.001–0.1eV order. Several kinds of materials of the TMR, their configurations, and their dimensions are investigated by the Monte Carlo simulation and optimized for developing the compact pulsed neutron source. The results would contribute to the construction of the Compact Pulsed Hadron Source (CPHS) at Tsinghua University, China. [Copyright &y& Elsevier]

Information on several topics which were discussed at the International Conference on Geo-spatial Solutions for Emergency Management (GSEM2009) in Beijing, China on September 14-19, 2009 is presented. Y. Zhang discussed the automated image fusion methods of University of New Brunswick (UNB) such as UNB-Pansharp techniques and fusion of synthetic aperture radar (SAR). W. Wagner said that converting research into operation depends on scientific algorithms and information technology infrastructure.

The previous compact hydrogen maser with sapphire microwave cavity at the Beijing Institute of Radio Metrology and Measurement was not suitable for a space application in navigation systems with limitations on volume and weight. To resolve this problem, we present a new design of the sapphire-loaded cavity with optimal parameters in the minimization of volume and maximization of the quality factor. Methods of theoretical calculations, finite element simulation, and related experiments were performed in designing the sapphire-loaded cavity. Based on the analysis, a miniaturized sapphire microwave cavity with the total volume of 3.04 dm³, the quality factor 67 500, and frequency-temperature coefficient -59.7 kHz/°C is developed. The experimental results are completely consistent with calculation values. In addition, the theoretical calculation result shows that the product of the z-component of the magnetic energy filling factor in the bulb region and the cavity TE011-mode Q-factor is 40 800 at 50°C in the miniaturized sapphire cavity. In addition, 2 sapphire-loaded cavities in the Japanese National Institute of Information and Communications Technology and in the Microwave and Optical Communication Research Institute at the University of Limoges, France, are compared with that of our designs. [ABSTRACT FROM AUTHOR]

First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping earlycareer researchers promote themselves alongside their papers. Zhong-Qiu Yu is first author on ' Visual detection of binary, ternary and quaternary protein interactions in fission yeast using a Pil1 co-tethering assay', published in JCS. Zhong-Qiu conducted the research described in this article while a postdoc in Li-Lin Du's lab at National Institute of Biological Sciences, Beijing, China. He is now a research associate in the lab of David Rubinsztein at Department of Medical Genetics, Cambridge Institute for Medical Research, UK, investigating protein degradation pathways and neurodegeneration diseases. [ABSTRACT FROM AUTHOR]

In order to achieve the United Nations 2030 Sustainable Development Goals (SDGs) related to green spaces, monitoring dynamic urban green spaces (UGSs) in cities around the world is crucial. Continuous dynamic UGS mapping is challenged by large computation, time consumption, and energy consumption requirements. Therefore, a fast and automated workflow is needed to produce a high-precision UGS map. In this study, we proposed an automatic workflow to produce up-to-date UGS maps using Otsu's algorithm, a Random Forest (RF) classifier, and the migrating training samples method in the Google Earth Engine (GEE) platform. We took the central urban area of Beijing, China, as the study area to validate this method, and we rapidly obtained an annual UGS map of the central urban area of Beijing from 2016 to 2020. The accuracy assessment results showed that the average overall accuracy (OA) and kappa coefficient (KC) were 96.47% and 94.25%, respectively. Additionally, we used six indicators to measure quality and temporal changes in the UGS spatial distribution between 2016 and 2020. In particular, we evaluated the quality of UGS using the urban greenness index (UGI) and Shannon's diversity index (SHDI) at the pixel level. The experimental results indicate the following: (1) The UGSs in the center of Beijing increased by 48.62 km2 from 2016 to 2020, and the increase was mainly focused in Chaoyang, Fengtai, and Shijingshan Districts. (2) The average proportion of relatively high and above levels (UGI > 0.5) in six districts increased by 2.71% in the study area from 2016 to 2020, and this proportion peaked at 36.04% in 2018. However, our result revealed that the increase was non-linear during this assessment period. (3) Although there was no significant increase or decrease in SHDI values in the study area, the distribution of the SHDI displayed a noticeable fluctuation in the northwest, southwest, and northeast regions of the study area between 2016 and 2020. Furthermore, we discussed and analyzed the influence of population on the spatial distribution of UGSs. We found that three of the five cold spots were located in the east and southeast of Haidian District. Therefore, the proposed workflow could provide rapid mapping and dynamic evaluation of the quality of UGS. [ABSTRACT FROM AUTHOR]

Sandstorms, which distribute many particles, are a special atmospheric occurrence and are frequent in northern China. We conducted this study to determine, for the first time, the concentration of polychlorinated biphenyls (PCBs) in sandstorm depositions. We collected 13 samples from urban areas of Beijing, and we measured a total of 144 PCB congeners. Thirteen samples all contained PCB residues. The total PCB concentration ranged from 1.6 to 15.6ngg−1 (median, 4.8ngg−1, dry weight), with trichlorinated biphenyls as the predominant homologue (>50.4%). Furthermore, we observed increasing PCB contamination from northwest to east Beijing. We later explored possible factors affecting contamination of the sandstorm depositions, which revealed a significant correlation between ∑PCBs and the minimum particle size of the sandstorm deposition samples. Principal-component analysis revealed that the major source of PCBs in Beijing may be potentially associated with the number-one commercial PCB through the long-range transmission. In previous results, PCBs were not a severe component of contamination in sandstorm depositions of Beijing. However, this study suggested that sandstorm deposition may be a potential source of exposure to PCBs for the residents of Beijing, China. [Copyright &y& Elsevier]

To determine the role of the migrant population in the transmission of tuberculosis (TB), we investigated the distribution and magnitude of TB in permanent residents and migrant populations of Beijing, People's Republic of China, from 2000 through 2006. An exploratory spatial data analysis was applied to detect the "hot spots" of TB among the 2 populations. Results, using the data obtained from 2004-2006, showed that people who migrated from the western, middle, and eastern zones of China had a significantly higher risk of having TB than did permanent residents. These findings indicate that population fluctuations have affected the rate of TB prevalence in Beijing, and interventions to control TB should include the migrant population. [ABSTRACT FROM AUTHOR]

Survival of Monilinia fructicola on the surface of mummified fruit and in peduncles and shoots of stone fruit trees infected by M. fructicola in the previous season was studied from 2003 to 2006 in orchards in the agricultural region of Beijing. Viable conidia of M. fructicola were consistently detected on fruit mummies from mid-March to the end of April. During flowering (in mid-April), studies in five peach orchards showed that 33–87% of mummified fruit bore viable conidia. The germination rate of conidia on diseased fruit was about 64% in autumn. It decreased to 24% in mid-winter when the fruit was completely mummified, and in the following year to 2–4% in early spring. Viable M. fructicola was consistently detected in peach and nectarine shoots collected in winter and spring. In general, viable M. fructicola in peduncles was detected from mummified fruit of 11–27% branches and from asymptomatic plant tissues of 3–20% branches. Sporulation of M. fructicola was observed on peduncles in seven of eight surveys, and the percentage of branches containing viable M. fructicola in peduncles in contact with mummified fruits ranged from 18% to 40%. This study demonstrates that the tree-borne mummified fruit and the peduncles could be the parts of trees where M. fructicola can survive the winter in orchards in suburban Beijing. [ABSTRACT FROM AUTHOR]

The article examines the use solid-phase extraction and high-performance liquid chromatography to determine forchlorfenuron residues in watermelon. The proposed method was applied to determine the residue levels and dissipation rates in watermelon grown in an experimental greenhouse in Beijing, China.

Seven freshwater and terrestrial amphipod species from Beijing, including one new species, Jesogammarus (Annanogammarus) debilis, are reported. A detailed description and illustrations of this new species are given and differences between these even species are discussed. A key to the amphipods of Beijing and their distribution data are also presented. [ABSTRACT FROM AUTHOR]

A new species of subterranean amphipod from China, Procrangonyx limpidus n. sp., is reported in the present paper. Detailed drawings of body parts and remarks on its affinities to related species are presented. [ABSTRACT FROM AUTHOR]

The Bashang area is a water-source area and ecological barrier zone for Beijing and Tianjin. The area is located at 200 km from Beijing and Tianjin and is a typical agriculture-pasture-interlacing zone, in which the eco-environment is vulnerable and hence it is sensitive to environmental change. The area is relatively lagged in social and economic development, where the traditional cultivation made is predominated in agriculture and animal husbandry, but the disturbance by human activity is relatively small. Therefore, in order to reveal the interrelation between eco-environmental change in the area and environmental change in Beijing and Tianjin area, it is fairly necessary to study the effect of land-use and land-cover change on nutrients in soil in this area. According to the actual situation of changed land use for the limited time period, five series of changed land plots were selected and 4 samples were collected from each series for the study. The samples were collected from different soil-farming level at the same site in different time. Analysis of the collected samples indicates that in the process of change of Zn, Cu, and Fe, have regularly changed. When the land had changed from grassland and non-irrigated farmland into woodland, and from non-irrigated farmland into irrigated field, the nutrients in soil totally increased. But there exists some exception, i.e. quick-acting N, P, K, and some microelements have appeared to be inconsistent with the mentioned above regularity in some areas. [ABSTRACT FROM AUTHOR]

A monitoring study was conducted in 2001 to determine the organochlorine pesticides and their metabolite residues in milk taken from supermarkets in Beijing, P. R. China. The average concentrations of total HCH and DDT were 0.038 and 0.046 mg kg[SUP-1], respectively, expressed on a fat basis. The aldrin residue was detected in nine milk samples, with a mean concentration of 0.035 mg kg[SUP-1]. Heptachlor and its epoxides were not found in any milk samples. Of 72 milk samples analysed, three from South China contained the higher levels of DDT and HCH residues that exceeded the FAO/WHO accepted tolerance level. Although organochlorine pesticides such as DDT and HCH have been banned in China since 1983, the residues of such compounds still exist in the environment and cause food contamination, a fact likely attributed to the short prohibition period and illegal use for agricultural purposes at present. [ABSTRACT FROM AUTHOR]

A number of high resolution and high signal-to-noise ratio spectra of mildly metal-poor stars were obtained with the coude´ echelle spectrograph attached to the 2.16m telescope at Xinglong Observation Base of Beijing Astronomical Observatory. The spectra of seven mildly metal-poor stars were processed with the MIDAS software package, and the equivalent widths of their spectral lines were measured. The measured equivalent widths together with an error analysis are presented. [Copyright &y& Elsevier]

While a number of network systems are running under certain stress with a limited lifetime, it is still unknown how to predict the lifetime–stress relation of complex systems. We develop a percolation-based approach to build an operational lifetime–stress model for complex networks, which captures the spatial and temporal reliability characteristics of the system. In this article, the general analytical expression for the entire operational lifetime–stress relation has been presented, which suggests that the load stress and the number of nodes in the network impact the operational lifetime in the same manner. The size effect found here in the lifetime–stress relation is observed for the first time, to our best knowledge. For 2-D lattices, we show that the lifetime–stress relation can be regarded as the combination of two parts—an approximately linear region for small stress, and nonlinear region for large stress. We also analyze the lifetime–stress function of Beijing road network and the western United States power grid. Our article might help to develop acceleration testing methods, which will facilitate better design of reliable complex systems. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of fertilization on soil chemical characteristics and ecological security, the chemical characteristics and ecological security risk analysis of heavy metal elements in a certain soil caused by fertilization were proposed. The contents of Ni, V, Cr, As, Cd, Pb, Zn, and Hg in 1,065 surface soil samples collected in a district of a city in the southwest agricultural area were tested and analyzed. Multivariate statistical analysis and spatial analysis were used to clarify the geochemical distribution characteristics of these heavy metals, and the possible main sources were also discussed. The results showed that the eight heavy metals could be divided into three categories. The first category included Ni, V, Cr, and As, whose content was lower than the background value in Beijing. And the distribution was mainly affected by natural factors such as parent materials of soil formation. The second category included Cd, Pb, and Zn, whose average content was higher than the background value. And the content was the highest in residential areas. In addition to the parent material inherited from the soil, the distribution characteristics of these elements were greatly affected by human activities. And Cd was significantly more affected by human activities than Pb and Zn. The third category included Hg, and it was inferred that atmospheric deposition was the main factor affecting the distribution of Hg. It was concluded that the Hakanson method was used to evaluate the ecological risk of heavy metals in soil, and the results showed that the potential ecological risk index was low in the area. [ABSTRACT FROM AUTHOR]

Fine particle matter (PM 2.5) pollution frequently occurs in winter with increased consumption for heating and decreased radiation and boundary-layer height. Under strict emission controls since 2013, the mass concentrations of PM 2.5 in Beijing decreased substantially in Winter 2017/2018. However, in March 2018, the mean PM 2.5 concentration doubled from ~40 to 87 μg m−3, the reason for which is still unclear in the context of significant emission reductions. Here, using PM 2.5 measurements, vertical observations, and reanalysis data, we found that this worsening was attributed to increasingly stable stratification characterized by temperature differences between 850 hPa and 1000 hPa, which reached the maximum value (−4 °C) for March from 1951 to 2018. Not limited to Beijing, positive anomalies in temperature differences occurred widely as a result of a westward transition in the center of the polar vortex. Away from the cold center and dominated by anomalous zonal westerlies, northern China was intruded by warm southerly winds. The warm regional advection increased positive anomalies in low-level temperature differences, and in turn, enhanced geopotential thickness throughout the troposphere. The adverse impact on pollution was also confirmed in comparison to the vortex pattern in January. The vortex changed from the elongated one with a split-flow pattern in January to the annular vortex with a major center over Novaya Zemlya in March. Correspondingly, Beijing was less affected by cold air masses and thereby under relatively stable stratification, which is unfavorable for pollution dispersion in March. Additionally, this aerosol pollution was further worsened by aerosol-induced deteriorating meteorological conditions. • Increased aerosol pollution in March 2018 occurred due to reduced vertical temperature differences. • Large-scale positive anomalies in temperature differences resulted from the westward transition of the center of the polar vortex. • The two-way feedback mechanism between meteorology and aerosols further worsened aerosol pollution. [ABSTRACT FROM AUTHOR]