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Influenza A viruses in animal reservoirs repeatedly cross species barriers to infect humans. Dogs are the closest companion animals to humans, but the role of dogs in the ecology of influenza viruses is unclear. H3N2 avian influenza viruses were transmitted to dogs around 2006 and have formed stable lineages. The long-term epidemic of avian-origin H3N2 virus in canines offers the best models to investigate the effect of dogs on the evolution of influenza viruses. Here, we carried out a systematic and comparative identification of the biological characteristics of H3N2 canine influenza viruses (CIVs) isolated worldwide over 10 years. We found that, during adaptation in dogs, H3N2 CIVs became able to recognize the human-like SAα2,6-Gal receptor, showed gradually increased hemagglutination (HA) acid stability and replication ability in human airway epithelial cells, and acquired a 100% transmission rate via respiratory droplets in a ferret model. We also found that human populations lack immunity to H3N2 CIVs, and even preexisting immunity derived from the present human seasonal influenza viruses cannot provide protection against H3N2 CIVs. Our results showed that canines may serve as intermediates for the adaptation of avian influenza viruses to humans. Continuous surveillance coordinated with risk assessment for CIVs is necessary.

China Antimicrobial Resistance Surveillance Network for Pets (CARPet) was established in 2021 to monitor the resistance profiles of clinical bacterial pathogens from companion animals. From 2018 to 2021, we recovered and tested 4,541 isolates from dogs and cats across 25 Chinese provinces, with Escherichia coli (18.5%) and Staphylococcus pseudintermedius (17.8%) being the most predominant bacterial species. The Enterobacterales were highly susceptible to tigecycline, meropenem, colistin, and amikacin (70.3%–100.0%), but showed moderate resistance to ampicillin, ceftriaxone, doxycycline, florfenicol, levofloxacin, enrofloxacin, and trimethoprim-sulfamethoxazole (29.3%–56.7%). About 66.3% of Acinetobacter spp. were resistant to florfenicol, with relatively low resistance to another 11 antibiotics (1.2%–23.3%). The Pseudomonas spp. showed high susceptibility to colistin (91.7%) and meropenem (88.3%). The coagulase-positive Staphylococcus spp. showed higher resistance rates to most antimicrobial agents than coagulase-negative Staphylococcus isolates. However, over 90.0% of Staphylococcus spp. were susceptible to linezolid, daptomycin and rifampin, and no vancomycin-resistant isolates were detected. E. faecium isolates demonstrated higher resistance rates to most antimicrobial agents than E. faecalis isolates. Streptococcus spp. isolates showed low resistance to most antimicrobial agents except for doxycycline (78.2%) and azithromycin (68.8%). Overall, the tested clinical isolates showed high rates of resistance to commonly used antimicrobial agents in companion animals. Therefore, it is crucial to strengthen the monitoring of bacterial resistance in pets. By timely and effectively collecting, analyzing, and reporting antimicrobial resistance dynamics in pets, the CARPet network will become a powerful platform to provide scientific guidance for both pet medical care and public health.

Influenza A viruses in animal reservoirs repeatedly cross species barrier to infect humans. Once an animal-borne virus with novel antigenicity acquired the efficient human to human transmissibility, it will become epidemic in the population. Dogs are the closest animal companions to humans and canine respiratory tract expresses both SAα2,3-(avian type) and α2,6-Gal (human type) receptors. However, the role of dogs in the ecology of influenza viruses is unclear. H3N2 avian influenza viruses transmitted to dogs around 2006 and have formed stable lineages. The long-term epidemic of avian-origin H3N2 virus in canine offers the best models to investigate the effect of dogs on the evolution of influenza viruses. Here, we carried out a systematic and comparative identification of the biological characteristics of H3N2 canine influenza viruses (CIVs) isolated in the worldwide over 10 years. We found that during the adaptation of H3N2 CIVs to dogs, H3N2 CIVs became to recognize the human-like SAα2,6-Gal receptor, gradually increased HA acid stability and replication ability in human airway epithelial cells, and acquired a 100% transmission rate via respiratory droplet in ferret model, which were essential hallmarks of being adapted to humans. We also identified that the frequency of substitutions related to human adaptation has gradually increased in H3N2 CIVs, and determined four cumulative molecular changes responsible for the increased airborne transmission ability in ferrets. Our results suggested that canine may serve as an intermediate for the adaptation of avian influenza virus to human. Continuous surveillance coordinated with risk assessment for CIVs is necessary.

Pseudorabies virus (PRV) is known to cause severe encephalitis in juvenile pigs and various non-native hosts; recent evidences suggest that PRV might cause encephalitis in humans. In a multicenter cohort study in China, next-generation sequencing of cerebrospinal fluid (CSF) was performed to detect pathogens in all patients with clinically suspected central nervous system infections. This study involved all the patients whose CSF samples were positive for PRV-DNA; their clinical features were evaluated, and species-specific PCR and serological tests were sequentially applied for validation. Among the 472 patients tested from June 1, 2016, to December 1, 2018, six were positive for PRV-DNA, which were partially validated by PCR and serological tests. Additionally, we retrospectively examined another case with similar clinical and neuroimaging appearance and detected the presence of PRV-DNA. These patients had similar clinical manifestations, including a rapid progression of panencephalitis, and similar neuroimaging features of symmetric lesions in the basal ganglia and bilateral hemispheres. Six of the patients were engaged in occupations connected with swine production. PRV infection should be suspected in patients with rapidly progressive panencephalitis and characteristic neuroimaging features, especially with exposure to swine.

Background: Feline parvovirus (FPV) is a member of the Parvoviridae family, which is a major enteric pathogen of cats worldwide. This study aimed to investigate the prevalence of feline parvovirus in Beijing, China and analyze the genetic features of detected viruses.Results: In this study, a total of 60 parvovirus-positive samples (8.5%) were detected from 702 cat fecal samples using parvovirus specific PCR. The complete VP2 genes were amplified from all these samples. Among them, 55 sequences were characterized as FPV (91.7%), the other five were typed as canine parvovirus type 2 (CPV-2) variants (8.3%), comprised of four CPV-2c and a new CPV-2b strain. In order to identify the origin of CPV-2 variants in cats, we amplified full-length VP2 genes from 7 fecal samples of dogs infected with CPV-2, which were further classified as CPV-2c. Moreover, the sequences of new CPV-2b/MT270586 and CPV-2c/MT270587 detected from feline samples shared 100% identity with previous canine isolates KT156833 and MF467242 respectively, indicating the CPV-2 variants circulating in cats were derived from dogs. Sequence analysis indicated new mutations, Ala91Ser and Ser192Phe, in the FPV sequences, while obtained CPV-2c carried mutations reported in Asian CPV variants, showing they share a common evolutionary pattern with the Asian 2c strains. Interestingly, the FPV sequence (MT270571), displaying four CPV-specific residues, was found to be a putative recombinant sequence between CPV-2c and FPV. Phylogenetic analysis of the VP2 gene showed that amino acid and nucleotide mutations promoted the evolution of different geographical branches of FPV and CPV lineages.Conclusions: Our findings will be helpful to further understand the circulation and evolution of canine and feline parvovirus in Beijing.

Grassland exclosures with fencing are commonly used to prevent shrub encroachment. However, few studies have been conducted on the effect of exclosures on soil macropores and root architecture during shrub encroachment. This study aimed to quantify the effects of exclosures on soil macropore and root characteristics beneath the encroached shrub C. microphylla L. in the Inner Mongolia grassland. Two exclosure treatments, 9EX (shrubland enclosed for 9 years) and 2EX (shrubland enclosed for 2 years), were designed, with free grazing plots serving as controls. A total of twelve soil cores (0–50 cm deep) were excavated, which included three replicates of each treatment and control. Soil and root architecture of the soil cores were explored using X-ray computed tomography method. Results indicated that macroporosity was 1.03–1.66 times greater in the soil under the enclosed C. microphylla L. than in the soil under the grazed C. microphylla L., and the soil macroporosity increased with exclosure age. Macropores were abundant over the 0–400 mm soil layers under the enclosed shrubland but were mainly present at 0–250 mm soil depth under freely grazed shrubland. Exclosure led to significant proliferation of shrub roots compared with grazing. Root density was 1.04–1.86 times greater in the soil under the enclosed C. microphylla L. than in the soil under the grazed C. microphylla L. Roots were concentrated in the 0–250 mm soil layer in the grazed shrubland, whereas roots were abundant over 0–400 mm in the enclosed shrubland. The high number of macropores under the enclosed shrubland was closely associated with a high root density. These results suggest that exclosure enhances shrub root proliferation and therefore increases soil macroporosity and soil pore connectivity, which would be favourable for shrub encroachment.

During 2012–2017, we collected throat swabs from dogs in China to characterize canine influenza virus (CIV) A(H3N2) isolates. A new antigenically and genetically distinct CIV H3N2 clade possessing mutations associated with mammalian adaptation emerged in 2016 and replaced previously circulating strains. This clade probably poses a risk for zoonotic infection.

The relationship between soil macropore and plant roots warrants special attention because it influences the behavior of water in soil. However, the influence of shrub roots on soil macropores in shrub-encroached grasslands is poorly understood. The objectives of this study were to quantify soil macropores and root architecture in a shrub-encroached grassland in northern China, and to reveal the relationship between shrub roots and soil macropore. In this study, treatments were performed that corresponded to three successional states of the shrub C. microphylla L. with three different shrub densities. At each site, three undisturbed soil cores were excavated under the shrub canopies, and a Philips medical scanner was used to simultaneously visualize and quantify the soil and root architectures. Strong positive correlations between root volume, length, and surface area and the solid surface/solid volume ratio were found, and greater root growth was noted in more porous soil. The results highlighted that the soil macropore characteristics corresponded well with the root characteristics of the soils for the three treatments. Soil macroporosity and macropore volume increased with increasing shrub root network density. In addition, the influence of plant roots on soil macropores increased with increasing shrub encroachment. The study confirmed that the large number of macropores found in the soils under shrubs was attributed to the great degree of root development there. The greater degree of macroporosity under shrubs was attributed to the larger root network density, which might cause greater amounts of water to be concentrated in the deep soil layer by macropore flow under shrub patches. The influence of plant roots on soil macropores increased with increasing shrub encroachment.

Built-up land in floodplains (BLF) is a driver and a disaster-bearing body of flood risk from a socio-hydrological perspective. The relationship between BLF growth and flood vulnerability is the key to understanding and managing flood risk. However, previous studies have focused more on the relationship between BLF growth and flood exposure, ignoring flood vulnerability. We examined the BLF expansion pattern (patch size and expansion type) in the North China Plain Area from 1975 to 2014 (1975–1990–2000–2014) using GIS (geographic information system)-based landscape analysis and revealed its relationship with flood vulnerability. The results show that the BLF area experienced rapid growth (288.26%) from dispersion to coalescence. Small patches dominated the number and area of BLF growth, and edge-expansion patches were the expansion type with the most area growth. We discovered that flood vulnerability was significantly correlated with the growth in small (R = 0.36, p < 0.01), edge-expansion (R = 0.53, p < 0.01), and outlying patches (R = 0.51, p < 0.01). Large patches were not significantly correlated with flood vulnerability (R = 0.18, p > 0.1), but there was a negative trend. Infilling patch growth was significantly associated with flood vulnerability over a long period (R = 0.27, p < 0.05). In addition, we suggest nature-based soft adaptations or village merging for small patches and outlying patches. Our findings have important scientific significance for adequately understanding the interplay between BLF growth and flood risk. It has practical implications for the formulation of integrated flood risk management strategy and the sustainable development of floodplains.

Desertification is a form of land degradation principally in semi-arid and arid areas influenced by climatic and human factors. As a country plagued by extensive sandy desertification and frequent sandstorms and dust storms, China has been trying to find ways to achieve the sustainable management of desertified lands. This paper reviewed the impact of climate change and anthropogenic activities on desertified areas, and the effort, outcome, and lessons learned from desertification control in China. Although drying and warming trends and growing population pressures exist in those areas, the expanding trend of desertified land achieved an overall reversal. In the past six decades, many efforts, including government policies, forestry, and desertification control programs, combined with eco-industrialization development, have been integrated to control the desertification in northern China. Positive human intervention including afforestation, and the rehabilitation of mobile sandy land, and water conservation have facilitated the return of arid and semi-arid ecosystems to a more balanced state. China’s practices in desertification control could provide valuable knowledge for sustainable desertified land management on a global scale.

Flooding is one of the most devastating natural events and leads to enormous and recurring loss of life, properties, and resources around the globe. With climate change and accelerating urbanization, flood disasters in China have increasingly affected the sustainable development of metropolitan areas. Risk assessment is an essential step in flood management and disaster mitigation, which provide a quantitative measure of flood risk. However, the difficulty of flood risk zoning is dealing with the uncertainty of the evaluation process and the complicated non-linear relationship between indicators and risk levels. To address this issue, a fuzzy synthetic evaluation (FSE) method based on combined weight (CW) was utilized in this paper to generate flood risk maps at a grid-scale (1 &times, 1 km). For the case study in the Beijing-Tianjin-Hebei metropolitan area (BTH) in China, fourteen indicators were selected to construct the flood risk assessment model based on the FSE approach integrated with ArcGIS. The research demonstrates that moderate, high, and very high risk zones are distributed in the southeast fluvial plain of the BTH area, accounting for 31.36% of the total land area. Meanwhile, low and very-low risk zones occupy 68.64% of the total land area, and are primarily located in the high plateau and mountain regions in the northwest. We analyzed the risk level of each county and proposed risk mitigation measures based on field investigations. The verified risk assessment results were spatially consistent with the historical flood disaster records and loss positions, indicating the accuracy and reliability of the risk assessment map using the FSE approach. Compared with the IPCC (Intergovernmental Panel on Climate Change) TAR (Third Assessment Report) and AR5 (Fifth Assessment Report) methods, FSE has significant advantages in handling uncertainty, complexity, and the non-linear relationship between indices and risk grades. This study provides a novel quantitative method for flood risk assessment in metropolitan areas and practical implications for urban flood management.

This study explored the interdecadal variations and their horizontal and vertical light extinction performances of atmospheric particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5), particulate matter with aerodynamic diameters ≤ 10 μm (PM10), and total suspended particulates (TSPs) in Beijing from 1980 to 2015, using data available from historical publications. Prominent declines of PM2.5, PM10, and TSPs were detected with long-term linear trends of −6.7, −4.3, and −1.9 μg m−3 yr−1, respectively. Generally, on the annual scale during the studied period, it was found that PM2.5 displayed negative correlation (R2 = 0.38, p

Dust transport and deposition processes are important for understanding the environmental risk of dust storms. This study investigated characteristics of dustfall at two rural sites and four urban sites from dust sources to downwind regions during three dust storms (DS1: March 19–22, DS2: April 24–26, DS3: May 7–10, 2010). Analysis of near-surface instantaneous maximum wind speed and prevailing wind direction revealed the dust storms bursted out from northwestern arid and semiarid regions to eastern China. Microaggregates, angular, subangular, columnar, subrounded, and spherical particles were identified by scanning electron microscope. Dust deposition flux (DDF) during the dust storms was significantly high at sites near sand deserts and sandy land. During DS2, DDF was 25.1, 9.9, 2.3, and 1.5 g m−2 in Jingbian, Shapotou, Lanzhou, and Beijing, respectively. The three dust storms contributed 7.3% of Beijing’s annual dustfall in 2010, which suggests anthropogenic dust might contribute the majority of annual dustfall in urban areas. The mass medium diameter of dustfall during DS2 in Shapotou, Jingbian, Lanzhou, and Beijing was 26.1, 9.0, 16.4, and 15.5 μm, respectively. Urban dustfall contained more heavy metals, sulfur and arsenic than rural dustfall. Cadmium contamination was identified in all urban dust particles. Anthropogenic pollutants in combination with mineral dust might lead to complex environmental risk on local, regional, and global scales. China’s environmental pollution control should integrate reductions in land desertification and multisource anthropogenic emissions within the context of climate change mitigation.

Grassland exclosure is a widely-used option to prevent from grazing in degraded grasslands for restoration. However, the influence of exclosure on soil macropore of grassland remain scarce. The objective of this study was to quantify the pore architecture of grassland soils under exclosure. Two treatments, 9E (grassland enclosed for 9 years) and 5E (grassland enclosed for 5 years), were designed, with grazing as a control in the experiment. Nine soil columns (0–50 cm deep) were taken at the three sites with three replicates. At each site, three soil columns were from the grassland, and cores were scanned with a Philips Brilliance ICT Medical Scanner. Numbers of macropores, macroporosity, network density, length density, and node density within the 50-cm soil profile were interpreted from X-ray computed tomography to analyze soil pore architecture. The results indicated that exclosure significantly influenced CT-measured soil macroporosity in the Inner Mongolia grassland of northern China. Soils under enclosed grassland had greater macroporosity, length density, total volume, and node density than that of under freely grazed grassland. Macroporosity increased as the enclosure age increased. For soils under enclosed grassland, macropores were concentrated at 0–300-mm soil layers, and macropores were mainly present at 0–100-mm soil depth under freely grazed grassland. The large number of macropores found in soil under enclosed grassland can be attributed to greater root development. Exclosure increases soil macroporosity and improve soil structure.

Flooding is one of the most destructive natural events that severely damage the ground and inundate underground infrastructure. Subway systems in metropolitan areas are susceptible to flooding, which may be exacerbated when land subsidence occurs. However, previous studies have focused on flood risk evaluation on regional/watershed-scales and land subsidence monitoring in plains, instead of on subway flood risk evaluation and how land subsidence aggravates the flood risk in subway systems. Using the proposed risk indicators and field survey data, we present a method assessing the flood risk of metropolitan subway systems under a subsidence condition based on the fuzzy analytic hierarchy process (FAHP) combined with a geographic information system (GIS). We use the regional risk level within the 500 m buffer zone of the subway line to depict the flood risk of the subway system. The proposed method was used to evaluate the flood risk of the Beijing subway system. The results show that the flood risks of the Beijing subway show a ring-like distribution pattern—risk levels decreasing from the central urban area to the suburbs. Very high and high risks are mainly located within third and fourth ring roads, accounting for 63.58% (29.40 km2) and 63.83% (81.19 km2) of the total area. Land subsidence exacerbated the Beijing subway system’s flood risk level—the moderate to very high risk increased by 46.88 km2 (16.33%), indicating that land subsidence is an essential factor affecting the flood risk level of subway systems. In addition to enhancing flood warnings, future subway flooding could be reduced by elevating the height of the stations’ exit (entrance) and installing water stop plates and watertight doors. This study is of great significance for flood warning and prevention in the Beijing subway system; it provides a theoretical basis for flood risk evaluation in other metropolitan areas.

The physicochemical characteristics of household dust in a typical metropolitan city (i.e., Beijing, the urban region) and a remote village in western of China (the rural region) were investigated and compared. The results show that the particles of household dust in both the regions could be classified as six types: micro-aggregates, biogenic, spherical, subrounded, subangular, and angular in morphology. Most dust particles were found to belong to the latter three types and belonged to mineral particles. The average particle size (aerodynamic equivalent diameter) of household dust was 16.1 and 14.9 μm in the rural and urban regions, respectively. Dust particles with diameters 10–20 μm were the highest by number in the both regions, while dust diameters from 30 to 40 μm and from 20 to 30 μm were the highest by volume in the urban and rural regions, respectively. The minerals in household dust particles in both the rural and urban regions were primarily quartz, albite, calcite, and dolomite. The average percentages of macro-element species (Si, Al, Ca, Fe, K, Mg, Na, P, and Ti) in household dust in the rural and urban regions were lower than those in the corresponding outdoor dust and their background values, except for Ca. Silicon, Al, Ca, Fe, and K were the predominant elements distributed in household dust in both the rural and urban regions. The concentrations of the studied macro-elements in the rural household dust were lower than those in the urban household dust, being in agreement with the relationship of the reference crust element content in the rural and urban regions. The average percentages of the ions in the rural and urban household dust were generally higher than those in the corresponding outdoor dust. The levels of SO 4 2− , NO 3 − , Cl − , and Ca 2+ in the urban household dust were higher than those in the rural, owing to human activities. The deposition rate of household dust in the rural region (i.e., 15.3 ± 2.6 g m −2 year −1 ) was approximately 10 times greater than that observed in the urban region due to worse tightness of the houses. Dust at homes was one of the significant sources of PM 10 in the residential environment through resuspension, and the studied properties of household dust are closely related to human health. Household dust in both the rural and urban regions of China should not be ignored.

Dust storm originates from arid and semiarid areas and could cause worldwide lasting effects along varying trajectories. As an extreme weather hazard, dust storm is usually induced by strong winds. In this paper, an aerodynamic parameter, defined as the ratio between dust storm frequency (DSF) and strong wind frequency (SWF), was calculated for quantifying dust storm susceptibility (DSS). The characteristic value and temporal change of DSS in five typical land surface areas, including cultivated land, grassland, sand desert, Gobi desert, and salt crust, were analyzed with dust storm and strong wind records at 15 weather stations. The spatial distribution of DSS in the arid and semiarid regions of northern China was described using dust storm and strong wind records at 102 meteorological stations. There are positive correlations between SWF and DSF for any identical land surface type. Land surface conditions have a great influence on dust storm susceptibility. According to DSS value, the five land surface types can be divided into two categories: (1) Cultivated land and sand desert, with DSS between 0.64 and 0.53, about 2.6–10 times higher than that of the other three land surfaces, are prone to forming dust storm under strong wind conditions; (2) Gobi desert, grassland and salt crust, with average DSS from 0.06 to 0.2, exhibit lower probability of dust storm occurrence under strong wind conditions. The DSF in the surrounding areas of the arid Taklimakan desert in Xinjiang are much larger than SWF, and dust storms take place readily even at normal erosive wind conditions. The areas with high DSF are not spatially consistent with SWF distribution but more coincide with high DSS areas where sand deserts and farmland are concentrated. In the nearly four past decades, the DSS showed an overall increasing trend on different ground surfaces which may be related to local human activities and climatic warming.

Climate change and simultaneous increases in extreme events have significant impacts on the structure and function of the global ecosystem. The response of the ecosystem on the Qinghai–Tibet Plateau (QTP) to climate change has drawn increasing attention for its prominent elevation. In this study, resistance and resilience were selected as two stability indicators of ecosystems to analyze the response of the QTP ecosystem to climate change over the past 34 years. We explored the main climate drivers that affect vegetation change, and predicted the stability of the ecosystem in the future. The results showed that the coniferous and Hylaea coniferous and hylaea forests of the QTP had high resilience, whereas the steppe and meadow had poor resilience. Shrubs and coniferous and hylaea coniferous and hylaea forests were with less resistance to climate change, whereas steppe and meadow showed more resistance to climate change. Temperature (TEMP) was the driving factor that affected the stability of steppe and meadow; however, precipitation (PRE) had a greater impact on stability of coniferous and hylaea forests and shrubs. Based on the CMIP5 results, TEMP and PRE on the QTP will significantly increase (p

All data are listed in Excel (.xlsx), including micro-mrophology of shrub shadow dunes at different spacings for the shrub with a height of 15cm at 9 m s-1; amount of sand trapped by shrubs; rate of sand trapped by shurbs; morphological parameters of shadow dunes at different spacings and wind velocities; variation in morphological parameters during process of shadow dune development.

Air pollutant emissions from agricultural burning are observed every year after harvest in China. While agriculture is not the main contributor to air pollution in China, agricultural activities can cause severe pollution events. Recognizing the key mechanisms involved in this process offers an opportunity to minimize pollution events caused by agricultural burning. In this paper, we review the meteorological conditions present during a selected air pollution episode and discuss those conditions using standard meteorological observations. The spatio-temporal variations of PM2.5 concentrations following agricultural burning in Beijing were measured from October 4 to October 7, 2013. This time period coincides with a Chinese public holiday and was selected because the influence of other anthropogenic emissions on air quality was strongly reduced during those days. As a result, we were able to identify the key sources and progress of a severe air pollution event. On October 4, average PM_(2.5) concentration in Beijing continuously increased from 49.7 μg m^(-3) at 1:00 to 302.5 μg m^(-3) at 23:00. Heavily polluted air (＞ 300 μg m^(-3)) initially appeared in southeastern Beijing on the afternoon of October 4. On October 5 and in the early morning of October 6, heavily polluted air masses moved into central Beijing, the inner suburbs, and the suburbs. From 0:00 on October 6 to 15:00 on October 7, the average PM_(2.5) concentration in Beijing decreased from 291.6 μg m^(-3) to 19.2 μg m^(-3). Active fire information derived from the MODIS sensors and back trajectory analysis show that field burning of agricultural residues after a harvest triggered and massively contributed to this severe air pollution event. The results improve our understanding of PM_(2.5) air pollution development processes, and they provide scientific support for the Chinese government to accelerate emission reductions from the field burning of agricultural residues.

Brucella spp. are facultative intracellular pathogens that cause a contagious zoonotic disease. Twelve different species are currently identified. This study presents the complete genome sequences of four Brucella strains. These complete genomes were annotated and the contents compared to those of other strains isolated from China.

Atmospheric particulate matter (PM) from multinatural and anthropogenic sources poses serious risk to human health and contaminates soil and water resources as it settles back to ground environment and ecosystem. In this study, dust deposition flux (DDF), pollution load index (PLI) of heavy metals, enrichment factor (EF), and settling flux (SF) of eighteen chemical elements were investigated in comparison with crustal composition to assess the influence of anthropogenic emission on PM in major northern Chinese cities. The annual DDF in Lanzhou, Huhhot, Beijing, Zhengzhou, and Harbin was 134.7, 240.6, 103.7, 124.7, and 196.7 g m−2, respectively. The annual EF of Zn in Harbin, Cd in Lanzhou, and Cd in Beijing was 736.4, 248.6, and 166.3, respectively. Most of the inspected elements were enriched during winter in Lanzhou. Annual PLI showed that deposited dust in Beijing had the highest concentration of heavy metals. Seasonal PLI exhibited obvious changes in different cities. The annual SF of crustal elements was 1–5 orders higher than that of heavy metals. The highest annual SF of elements was identified mainly in Lanzhou and Huhhot. Sulfur, cadmium, copper, lead, and zinc in the dustfall of most urban areas were from human activities. Fossil fuel burning, metal smelting, mining, construction, and vehicle exhaust are the major sources of enriched elements in dustfall in urban areas of northern China. Toxic pollutants with dustfall are widespread and persistent, which deserves public concern in future sustainable development.

Bioinformatics and comparative genomics analysis methods were used to predict unknown pathogen genes based on homology with identified or functionally clustered genes. In this study, the genes of common pathogens were analyzed to screen and identify genes associated with intracellular survival through sequence similarity, phylogenetic tree analysis and the λ-Red recombination system test method. The total 38,952 protein-coding genes of common pathogens were divided into 19,775 clusters. As demonstrated through a COG analysis, information storage and processing genes might play an important role intracellular survival. Only 19 clusters were present in facultative intracellular pathogens, and not all were present in extracellular pathogens. Construction of a phylogenetic tree selected 18 of these 19 clusters. Comparisons with the DEG database and previous research revealed that seven other clusters are considered essential gene clusters and that seven other clusters are associated with intracellular survival. Moreover, this study confirmed that clusters screened by orthologs with similar function could be replaced with an approved uvrY gene and its orthologs, and the results revealed that the usg gene is associated with intracellular survival. The study improves the current understanding of intracellular pathogens characteristics and allows further exploration of the intracellular survival-related gene modules in these pathogens.

Blown sand disasters are caused by sand activity. It can lead to casualties of people and livestock, declining productivity of farmland and pasture, damage to buildings, roads, communication and other facilities, as well as deterioration of air quality (Gao et al. 2000). In northern China, due to the dry and windy climate and large land areas that are covered with sparse vegetation, sand activity is intense and blown sand disasters occur frequently with serious damages. Depending on the severity, sand and dust storm (SDS) weathers can be divided into floating dust, sand-blowing, and sand and dust storm types. Among these, strong and extremely strong sand and dust storms are the main types of SDS weather that causes blown sand disasters (CMA 2006). Sandstorm and dust storm have been a notable natural phenomenon in northern China historically (Zhang 1982). Due to the constantly growing human activities, the coupling effect of land desertification and climatic aridification has been strengthened and thus increases the risk of blown sand disasters. This chapter discusses sand and dust storm and blown sand disasters in northern China, including the spatiotemporal distribution characteristics of sand and dust storms, formation process of blown sand disasters and influences, blown sand disaster risk, and a case of blown sand disasters in China in 2000.

Background Since late 2011, cases of suspected canine pseudorabies have increased in north China with the outbreak of swine pseudorabies in the same area, but the pathogenesis of canine Pseudorabies virus (PRV) infections in China is poorly understood. In this study, we investigated the pathogenesis of canine pseudorabies. Methods The pathological changes in 13 dogs that died of natural PRV infections (confirmed by pathogen detection) during 2011–2013 in Beijing were evaluated. An experimental study was also conducted in which healthy adult beagle dogs were administered PRV isolate BJ-YT by subcutaneous injection. The dog tissues were subjected to gross and microscopic examinations and immunohistochemical analysis and the dogs’ serum cardiac troponin-I (cTn-I) was measured. Results Systemic hemorrhage and/or congestion were the most marked pathological changes in both the naturally and experimentally PRV-infected dogs. Macroscopically, the major lesions consisted of petechiae and ecchymoses in both the endocardium and epicardium, thrombi in the mitral valves, hemorrhage in the lungs and thymus, and incomplete contraction of the spleen. Microscopically, the major histopathological findings were systemic hemorrhage and congestion, nonsuppurative ganglioneuritis (in the experimentally infected dogs, unexamined in the naturally PRV-infected dogs), brainstem encephalitis (in the naturally infected dogs), necrosis or exudation in the myocardium, and lymphoid depletion in many lymphoid organs and tissues. Viral antigens were only detected in the brainstems and peripheral ganglia of the infected dogs. Serum cTn-I was significantly higher in the experimentally PRV-infected dogs with myocardial lesions than in the dogs without myocardial lesions. Conclusions Based on these results, we conclude that virally induced systemic hemorrhage, peripheral nervous system pathology, and/or cardiac injury can individually or collectively cause death in PRV-infected dogs. The respiratory signs of the disease are attributed to cardiogenic lesions.