Search

Background: Viral diseases are posing threat to annual production and quality of tobacco in China. Recently, tomato spotted wilt orthotospovirus (TSWV) has been reported to infect three major crops including tobacco. Current study was aimed to investigate the population dynamics and molecular diversity of the TSWV. In the current study, to assess and identify the prevalence and evolutionary history of TSWV in tobacco crops in China, full-length genome sequences of TSWV isolates from tobacco, were identified and analyzed. Methods: After trimming and validation, sequences of new isolates were submitted to GenBank. We identified the full-length genomes of ten TSWV isolates, infecting tobacco plants from various regions of China. Besides these, six isolates were partially sequenced. Phylogenetic analysis was performed to assess the relativeness of newly identified sequences and corresponding sequences from GenBank. Recombination and population dynamics analysis was performed using RDP4, RAT, and statistical estimation. Reassortment analysis was performed using MegaX software. Results: Phylogenetic analysis of 41 newly identified sequences, depicted that the majority of the Chinese isolates have separate placement in the tree. RDP4 software predicted that RNA M of newly reported isolate YNKM-2 had a recombinant region spanning from 3111 to 3811 bp. The indication of parental sequences (YNKMXD and YNHHKY) from newly identified isolates, revealed the conservation of local TSWV population. Genetic diversity and population dynamics analysis also support the same trend. RNA M was highlighted to be more capable of mutating or evolving as revealed by data obtained from RDP4, RAT, population dynamics, and phylogenetic analyses. Reassortment analysis revealed that it might have happened in L segment of TSWV isolate YNKMXD (reported herein). Conclusion: Taken together, this is the first detailed study revealing the pattern of TWSV genetic diversity, and population dynamics helping to better understand the ability of this pathogen to drastically reduce the tobacco production in China. Also, this is a valuable addition to the existing worldwide profile of TSWV, especially in China, where a few studies related to TSWV have been reported including only one complete genome of this virus isolated from tobacco plants. [ABSTRACT FROM AUTHOR]

• The angle of calculative governmentality is proposed to interpret the role of state. • Local state maintains dominance via calculation in democratized urban redevelopment. • Calculative tactics included vague criteria, redistricting, and differentiation. Recently, the role of the state in urban redevelopment has drawn increasing scholarly attention. However, insufficient efforts have been made to determine how the state intervenes in and legitimizes the processes of urban redevelopment. Existing theoretical angles have also not provided convincing explanations for the democratization of urban redevelopment in some traditionally authoritarian regimes. Hence, this study attempts to narrow these gaps by examining the politics of urban redevelopment in Chengdu, China, from a Foucauldian governmentality perspective. A series of calculative tactics was adopted to promote the processes of reaching an agreement and legitimizing the demolition of old communities. These tactics enabled the local state to maintain its dominance in the participatory politics of urban redevelopment. This study contributes to the literature on urban redevelopment by elaborating the processes and roles of the state and governmentality and clarifying the calculative foundation of democratized urban politics in authoritarian regimes. [ABSTRACT FROM AUTHOR]

Chinese urbanites' housing differentiation is a subject that attracts increasing scholarly attention. Previously, housing differentiation was measured by access to homeownership and housing tenure. Given high Chinese homeownership rates, however, heterogeneity among urban Chinese homeowners should be further decomposed. Many studies identified links between housing differentiation and social stratification, but few have examined residents' responses to their homes. Based on the China Labour-force Dynamics Survey (CLDS), this study decomposes homeowners' housing differentiation along three dimensions: housing conditions, housing wealth, and neighbourhood environment. We also examine the impacts of these dimensions on homeowners' subjective social status (SSS). Significant differentiation is found among homeowners in housing conditions, neighbourhood environment, and housing loans. Furthermore, housing wealth and neighbourhood environment affect homeowners' perceived social status. These findings advance housing differentiation studies and have important implications for policies aimed at reducing social inequality and housing poverty. [ABSTRACT FROM AUTHOR]

This paper reviews the genealogy of 'Chinese' political geography, which, to a certain extent, can be read as a national report of the status of political geography in Chinese scholarship. It begins by outlining the short duration of the development of political geography in China, compared to the longer history of western political geography. Looking at the extant studies related to political geography in China, this paper suggests an existence of a duality in this field. One strand of scholarship is termed 'exogenous political geography', which is largely influenced by western scholarship with a particular focus on theories and vocabularies from classical geopolitics and geo-economy. The other strand is termed as 'endogenous political geography', which covers rich topics, including, yet not limited to, political and geographical views of inter-state relationships, central-local relationships and emperor-people relationships. Such a duality is important for understanding the condition of current political geography in China. The dualised understanding, however, seems to have undermined the comprehensiveness of political geography in China. In this regard, this paper calls for a more complete, integrated and critical agenda for political geography in China. [ABSTRACT FROM AUTHOR]

The literature on residential mobility pays little attention to the outcomes of residential relocation and their determinants. This study aims to address this shortfall by examining the link between home relocation and change in residential satisfaction based on data from a two-wave sample survey in Beijing, China. The data is collected through interviews with a sample of 537 participants who planned to move and eventually did move in Beijing. A multi-level structural equation model is developed to analyse the determinants of change in residential satisfaction after home relocation. The results show that people generally become more satisfied with their residence after relocation. The major determinants of residential satisfaction changes are adjustments in housing conditions (including housing tenure and dwelling space) and neighbourhood environment (including physical design, absence of nuisance, social interaction and accessibility to various facilities). The findings of this research not only enrich the literature on residential satisfaction and residential mobility, but may also help to improve urban planning and public housing policies. [ABSTRACT FROM AUTHOR]

The Chinese hukou system has been a hot topic in China study for decades. It not only restricts access to state-sponsored benefits (such as food and housing provision) in pre-reform China, but continues to influence the local-led urbanization in post-reform era. However, few studies have explained why this highly exploitative system persists in China. This paper tries to contribute some insights to interpretation of this issue based on Foucault’s concept of governmentality. It is argued that Chinese hukou system is actually a power relation consisting of a series of governmental technologies based on differentiation, surveillance and calculation in pursuit of economic growth and political stability. The governmental techniques and rationality within the Chinese institutional system make the hukou system persist in modern China. [ABSTRACT FROM AUTHOR]

Virus particles of approximately 740-760 nm in length and 13 nm in diameter were observed from a diseased Nicotiana tabacum (tobacco) plant in Sichuan Province, China. The complete genomic sequence of the virus isolate XC1 was determined to contain 9659 nucleotides without 3′ terminal poly(A) tail. XC1 has a genome typical of members of the genus Potyvirus, encoding a large polyprotein of 3075 amino acids. Putative proteolytic cleavage sites and a number of well characterized functional motifs were identified by sequence comparisons with those of known potyviruses. Sequence comparison revealed that XC1 shared the highest level of nucleotide sequence identity (76.5%) with Wild tomato mosaic virus ( WTMV). Phylogenetic analysis showed that XC1 was closely related to the WTMV Guangdong isolate with an identity of 94.3% between CP gene sequence of the two viruses. We thus named XC1 WTMV- XC-1 as a novel isolate of WTMV. The full sequence of WTMV- XC-1 may serve as a basis for future investigations on the gene diversity of WTMV. [ABSTRACT FROM AUTHOR]

Landslides are one of the most destructive disasters that cause damage to both property and life every year. The mountainous terrain, heavy and prolonged rainfall and dense development near steep hillsides make Hong Kong as one of the most vulnerable metropolitans to the risk of landslides. Therefore, regional-specific landslide susceptibility assessment in Hong Kong is necessary for hazard management and effective land use planning. Various methodologies have been proposed for landslide susceptibility mappings. By applying the statistically based frequency ratio and logistic regression models in Lantau Island, Hong Kong, this study attempts to add extra value to the literature of evaluating their ‘prediction rate’ (rather than ‘success rate’) for landslide susceptibility mapping in a temporal context. The spatial relationship among landslide occurrence and nine causative factors (elevation, slope, aspect, plan curvature, profile curvature, normalized difference vegetation index (NDVI), distance to river, distance to fault and lithology) were examined, and landslide susceptibility maps were generated by frequency ratio and logistic regression model. Validations of the mapping results were performed by calculating relative operating characteristics (ROC). Virtually all previous studies randomly extracted and reserved a portion of historical landslide records to perform the model evaluation. In contrast, in this study, 1864 (70%) landslide records in the Enhanced Natural Terrain Landslide Inventory from 2000 to 2008 are utilized to train the model, while the subsequent 799 (30%) landslides occurred from 2008 to 2009 are used for model validation. The validation result shows that logistic regression model (84.05%) possesses a better prediction power than frequency ratio model (76.64%) for the study area. This study attempts to offer a new model assessment strategy for landslide susceptibility mapping. The resultant maps also provide a scientific assessment of the risk areas with respect to landslides on Lantau Island and could serve as a basis for decisions or justification of the Lantau development planning. [ABSTRACT FROM PUBLISHER]

• Exposure to urban greenness and mixed land-use impact residents' life satisfaction. • Greenness-life satisfaction relationship is positive at residence, negative at workplace. • Mixed land-use generates positive impacts on life satisfaction at residence and workplaces. • There is positive interaction between greenness and mixed land-use on life satisfaction. China's unprecedented urbanisation in the last several decades has significantly transformed its urban built environment. On the one hand, such an urbanisation has brought about improvement in infrastructure, access to various public facilities, and opportunities for social connectivity, all of which would benefit citizen's wellbeing. On the other hand, rapid, unplanned, and unregulated urbanisation may lead to air pollution and water pollution, compact neighbourhoods, traffic noise and congestion, and lack of natural amenity, which pose various threats to urban dwellers' wellbeing and life satisfaction. Therefore, how to build liveable cities has become one of the key goals and top priorities of urban planning in China and other developing countries. This study investigates the effect of urban greenness and mixed land-use, two key dimensions defining urban liveability, on residents' life satisfaction at both residence and workplace settings in Beijing. Three big geo-coded datasets are combined, including a social survey about residents' subjective life satisfaction and demographic characteristics, eye-sensored street greenness data extracted from online platform through machine learning, and fine-grain land-use data based on point-of-interest entropy, and then taken into a Bayesian multilevel ordered logit model. The empirical results reveal that (1) street view greenness could enhance life satisfaction at residence, but depress life satisfaction at workplace; (2) mixed land-use could positively contribute to life satisfaction at both residence and workplace; and (3) there exist positive interactions between greenness and mixed land-use. These empirical findings provide practical implications for planning and constructing liveable cities in China and other countries where both urban greening and mixed land-use are promoted and embraced as core elements of the compact city and smart city ideal. [ABSTRACT FROM AUTHOR]

As a major aspect of the 'China Model', urbanization in China is being heatedly discussed in the Anglophone literature in the last two decades. By considering China's urbanization as a 'testing ground' of 'western' theories, these studies are important for the understanding of China's ongoing urban restructuring and exchanging knowledge with 'western' insights. Based on a survey of existing studies, this paper identifies various endogenous and exogenous concepts and explanations of China's urbanization. It is suggested that China's urbanization is mainly driven by a combination of political decentralization and neoliberalization with various forms of social stratification and mobility. However, it is argued that the distinctness of the 'China Model', which is usually used to support the legitimacy of studies of China's urbanization, has led to many controversial arguments and diminished the due contributions of Chinese scholars in the knowledge production of China's urbanization. To consolidate the legitimacy of studies on China's urbanization and enhance the roles of Chinese scholars, we suggest future studies to pay more attentions to the fundamental theories with looser constraints and 'true questions' on Chi [ABSTRACT FROM AUTHOR]

lentiviral vaccine, live attenuated equine infectious anemia virus (EIAV) vaccine, was developed in the 1970s, and this has made tremendous contributions to the control of equine infectious anemia (EIA) in China. Four key virus strains were generated during the attenuation of the EIAV vaccine: the original Liao-Ning strain (EIAV), a donkey-adapted virulent strain (EIAV), a donkey-leukocyte-attenuated vaccine strain (EIAV), and a fetal donkey dermal cell (FDD)-adapted vaccine strain (EIAV). In this study, we analyzed the proviral genomes of these four EIAV strains and found a series of consensus substitutions among these strains. These mutations provide useful information for understanding the genetic basis of EIAV attenuation. Our results suggest that multiple mutations in a variety of genes in our attenuated EIAV vaccines not only provide a basis for virulence attenuation and induction of protective immunity but also greatly reduce the risk of reversion to virulence. [ABSTRACT FROM AUTHOR]

Much scholarly attention has been paid to the urban transformation occurring in China. A large amount of literature pertains to the role of local governments in Chinese coastal cities, but very few studies have focused on the relations between local governments and the capital flow process, especially regarding inland cities with little foreign and domestic investment. Using Ordos as a case study, this paper proposes a model of “local government-directed capital switching” to explain how new town projects are financed and what roles local governments play in capital switching. In contrast with Harvey's model of capital switching, we find that the Ordos government has dominated the three circuits of capital accumulation in the new town making through a series of administrative measures. It follows the logic of “spatial fix” and yet adopts quite different strategies to channel the capital accumulated in the primary circuit into the built environment. The crisis associated with this capital switching model is also discussed. [ABSTRACT FROM AUTHOR]

Tobacco mosaic virus (TMV) is widespread in China and causes considerable economic losses to tobacco production. The molecular epidemiology of this virus is, however, poorly understood. In this study, we sequenced the genomes of 51 TMV isolates from five tobacco-producing regions in China and investigated the dispersal patterns of this virus. Our phylogenetic analysis showed that TMV might have been introduced to China in the early 1900s, probably first to southwest China. However, TMV then moved to the north of the country, where it expanded. The north became the main seeding region for the subsequent movements of the virus within China. The north-to-south movement of TMV coincides with a shift of major tobacco-producing areas from north to south in this century, suggesting a link between human activities and the dispersal of TMV in China. • TMV was introduced into the Southwest producing region of China before its spread through the country. • Gene flow has occurred between TMV populations, generally along a north-to-south axis in China. • Demographic expansions of TMV in China are potentially linked to tobacco production. [ABSTRACT FROM AUTHOR]

• Bacillus siamensis could suppress the mycelial growth and sporulation of Alternaria alternata. • Bacillus siamensis increased defense-related enzyme activities in tobacco plant. • It could be potential PGPR used to control tobacco brown spot disease. Tobacco brown spot disease, caused by Alternaria alternata , is responsible for causing significant losses in tobacco production in China. The use of biocontrol microorganisms to prevent and control this disease represent an important, environment-friendly, management strategy. In the present study, 17 bacterial strains with antimicrobial activity were isolated from 40 rhizosphere soil samples and evaluated for antifungal activity to identify an effective biocontrol agent for the control of tobacco brown spot disease in tobacco. Among the isolated strains, Bacillus siamensis, strain LZ88, exhibited the strongest antifungal activity with an inhibition rate of 81.96%. We confirmed that strain LZ88 controlled both mycelial growth and spore production in A. alternata by secreting protein-like antifungal metabolites and through the release of volatile organic compounds. Strain LZ88 also had the ability to induce plant basal immunity as evidenced by increased expression of the defense-related enzymes, peroxidase (POD) and polyphenol oxidase (PPO), in tobacco leaves. Results of greenhouse experiments indicated that LZ88 could effectively reduce the occurrence and degree of severity of tobacco brown spot disease. To the best of our knowledge, this is the first report regarding the use of B. siamensis to control brown spot disease in tobacco. [ABSTRACT FROM AUTHOR]

Background: Tobacco production in China has been affected by plant viruses with Milk vetch dwarf virus (MDV) as a recent invader posing serious concern. According to most of the studies, MDV mainly infects hosts from Fabaceae family but in our previous study we reported its infection in tobacco plant (Nicotiana tabacum L.) in Shandong province., Findings: In current study (2016-2017), tobacco plants (Nicotiana tabacum) with severe stunting, yellowing and axillary bunch of new leaves were observed in Zhengning, Gansu province. Isolate GSZN yielded into eight genomic circular single-stranded DNA components while no alphasatellite DNA was obtained. High percent identity of this isolate was recorded in overall nucleotide and amino acid assembly with reported MDV isolates worldwide. Phylogenetic analysis fetched into a separate sub-clade comprising of new isolate along with other tobacco infecting isolates of MDV. While recombination was predicted in DNA-C encoding Clink protein and DNA-U1, which may attribute towards the potential host-shifting phenomenon and ability of this virus to expand its host range., Conclusion: To our knowledge this is the first full genome annotation of a Nanovirus, infecting tobacco in natural field conditions, also this is the first extended analysis on host-shifting behavior of MDV.

Milk vetch dwarf virus (MDV) is a member of the genus Nanovirus, and its genome is composed of multiple circular 1-kb ssDNA components. In this study, we first determined that the diseased tobacco samples obtained in Zhucheng, Shandong Province were naturally infected with MDV using a polymerase chain reaction (PCR) assay. Subsequently, loop-mediated isothermal amplification (LAMP) was developed for the detection of MDV for the first time. The Mg 2+ and dNTP concentrations and the reaction temperature and time of the LAMP were optimized to 8 mM, 1.8 mM, 65 °C, and 60 min, respectively. The best ratio of the inner primers (FIP and BIP) to the outer primers (F3 and B3) was 2:1. The LAMP detection limit was 100 times greater than that of PCR. The nucleotide amplification could be clearly observed by adding SYBR Green I. The positive and negative reactions exhibit distinctly different colors in daylight; however, the positive reactions exhibit green fluorescence under a UV lamp. Therefore, the method is stable, sensitive and specific., (Copyright © 2018. Published by Elsevier B.V.)