Central South China Research Articles

Genome characteristics of atypical porcine pestivirus from abortion cases in Shandong Province, China

BackgroundAtypical porcine pestivirus (APPV) is a novel, highly variable porcine pestivirus. Previous reports have suggested that the virus is associated with congenital tremor (CT) type A-II in piglets, and little information is available about the correlation between the virus and sow abortion, or on coinfection with other viruses. In China, reported APPV strains were mainly isolated from South China and Central China, and data about the APPV genome from northern China are relatively scarce.MethodsEleven umbilical cords, one placenta, and one aborted piglet, were collected from aborted sows of the same farm in Shandong Province of northern China. Nucleic acids were extracted from the above samples, and subsequently pooled for viral metagenomics sequencing and bioinformatics analysis. The viral coexistence status and complete genome characteristics of APPV in Shandong Province were determined.ResultsIn abortion cases, APPV was present with Getah virus, porcine picobirnavirus, porcine kobuvirus, porcine sapovirus, Po-Circo-like virus, porcine serum-associated circular virus, porcine bocavirus 1, porcine parvovirus 1, porcine parvovirus 3 and porcine circovirus 3, etc. The first complete genome sequence(11,556 nt) of APPV in Shandong Province of northern China, was obtained using viral metagenomics and designated APPV-SDHY-2022. Comparison with Chinese reference strains revealed that the polyprotein of APPV-SDHY-2022 shared 82.6-84.2%, 93.2-93.6%, and 80.7-85% nucleotide identity and 91.4-92.4%, 96.4-97.7%, and 90.6-92.2% amino acid identity with those of the Clade I, Clade II and Clade III strains, respectively. Phylogenetic analysis based on the complete polyprotein CDS and NS5A sequences concluded that APPV-SDHY-2022 belongs to Clade II. Analysis of the NS5A nucleotide sequences revealed homology of greater than 94.6% for the same isoform, 84.7-94.5% for different isoforms of the same clade and 76.8-81.1% for different clades. Therefore, Clade II was further divided into three subclades, and APPV-SDHY-2022 belonged to subclade 2.3. Members of Clade II have 20 unique amino acids in individual proteins, distinguishing them from Clade I and Clade III members. The E2 protein showed the greatest diversity of putative N-glycosylation sites with 9 patterns, and APPV-SDHY-2022 along with other Chinese APPV strains shared the conserved B-cell conformational epitope residues 39E, 70R, 173R, 190K and 191N of the E2 protein.ConclusionsWe reported viral coexistence and the first complete genome sequence of APPV from abortion cases and from Shandong Province. The new APPV isolate belongs to an independent branch of Clade II. Our results increase the molecular and epidemiological understanding of APPV in China.

Shortening food supply chain in home-grown school feeding: experiences and lessons from south central China

Abstract Both home-grown school feeding (HGSF) and short food supply chain (SFSC) emphasize on proximity and aim to strengthen the competitiveness of local smallholder farmers. From a theoretical perspective, HGSF implemented as a type of SFSC could help deliver synergies. A pivotal question is how HGSF can be combined with SFSC and the benefits and drawbacks of such combination. Using an HGSF program which was implemented as an integral part of a free preschool lunch pilot in South Central China, this paper shows that HGSF and SFSC (in its full term) could be combined through one structured demand intervention. This study uses both qualitative and quantitative materials. Qualitative data were collected through focus group discussions with government and preschool staff, parents or caregivers, cooks, World Food Programme representatives and other stakeholders involved in the pilot program. The quantitative part used both small panel data and cross-sectional data from 106 smallholders. This study analyzes the design, implementation, good practices, benefits and constraints of the HGSF-SFSC model. We find that direct purchase from smallholder farmers was linked with higher income and production and dietary diversity. Moreover, this study identifies several constraints of the current HGSF-SFSC model. The policy implications for sustaining and scaling up the current pilot are discussed in the paper.

Impacts of changes in climate extremes on wildfire occurrences in China

Climate change has caused more frequent instances of extreme climatic events around the world, being an influential factor on the occurrence of wildfires in China on large scale. However, the impact of changes in extreme climate on the occurrence of wildfires in different climate zones remains unclear. In the present study, 26 extreme climate indices were selected to analyze the thereof relationship with wildfire occurrences from 2005 to 2018 in different regions of China. Wildfires in China primarily occur in the south, with a measurable presence in the north. On an annual scale, the wildfire occurrences in southwestern China show stronger correlations with mean temperature than extreme temperature indices, but show stronger correlations with extreme precipitation indices than the total precipitation. On the contrary, the wildfire occurrences in southeastern China show stronger correlations with the total precipitation than extreme precipitation indices, but show stronger correlations with extreme temperature indices than the mean temperature. In Northeast China, wildfires show a more significant correlation with mean temperature than with any extreme climate indices, indicating a minimal impact from extreme climatic conditions. The fire-climate relationships in the main fire season (January-April) are similar to those in the annual scale. The wildfire occurrences in the southwestern, south-central, and southeastern China, which are located in the same latitudes, were affected by extreme climate indices of different types and on different time scales. Furthermore, we recommend that consecutive dry days (CDD) and diurnal temperature range (DTR) should be considered first when studying the relationship between wildfire occurrence and extreme climate in southwestern and southeastern China respectively.

Evolution of Cenozoic sedimentary architecture in Central and Southern South China Sea basins

The Central and Southern South China Sea (CSSCS) has a complex tectonic dynamic background and abundant oil and gas resources, which has always been a hot topic of academic and industrial attention. However, systematic analyses are still lacking regarding its sediment filling structure and evolution, mostly due to limited borehole penetration and poor quality of seismic reflection data for deeply buried sequences. No consensus has been reached yet on the sedimentary infilling processes, which impeded the reconstruction of the palaeogeography of Southeast Asia and the oil-and-gas exploration undertakings. Here, we illustrate the Cenozoic sedimentary evolution of the CSSCS region by synthesizing relevant data from previous literature and our own observations and displaying the evolution of depositional systems in sequential reconstructions. Besides, the controlling factors of preferred sedimentary scenarios in the CSSCS incorporate the latest interpretations of the spreading of South China Sea (SCS) as well as the demise of the hypothetical Proto-South China Sea (PSCS). The results show that there are three types of sedimentary basins in the CSSCS (foreland, strike-slip, and rift basins) with different sedimentary filling structures. The foreland basins formed a depositional pattern of ‘transition from deep water to shallow water environments’, dominated by deep-water depositional systems which were formed before the Early Oligocene with submarine fans developed. Later, the foreland basins were gradually dominated by shallow-water depositional systems with deltas and shallow marine facies. The strike-slip basins showed the depositional architecture of ‘transition from lake to marine environments’, i.e. the basins were dominated by lacustrine deposits during the Eocene and evolved into the marine depositional environment since Oligocene with delta developed in the western part of the basin. The depositional evolution of rift basins illustrated the characteristics of ‘transition from clastic to carbonate deposits’, i.e., the rift basins were dominated by Eocene–Oligocene shallow marine clastic depositional systems, while carbonate platforms started to develop since the Early Oligocene from east to west. The above-mentioned differences of depositional architecture in the CSSCS were controlled by the scissor-style closure of the PSCS and the progressive-style expansion of the SCS. Specifically, the early-period deep-water sedimentary environment of CSSCS basins was controlled by the distribution of PSCS in the Eocene. As the scissor-style closure of PSCS progressed from west to east during the Oligocene to Early Miocene, the northwest of Borneo continued to rise, providing a great number of clastic materials to the basins and gradually developing large-scale deltas from west to east. The distribution of early-period lacustrine sedimentation of strike-slip basins was affected by paleo uplift, and the basins transgressed from the northeast and gradually evolved into marine sedimentary environment due to the expansion of SCS. The expansion of SCS also controlled the sedimentary filling evolution of the rift basins, which broke away from the South China continent and drifted southward. Thus, the rift basins lacked the supply of terrigenous clastic sediments which hindered the development of large-scale deltas and formed a clear water environment conducive to the development of carbonate platforms from east to west.

Paleostress reconstruction of the Chaling-Yongxing basin in the central South China Block: Bulk (areal or multisite) vs. site stress tensors

A critical problem in fault-slip data stress analysis is separating the heterogeneous fault-slip data into homogeneous subsets. Recent attempts to solve this problem use tectonostratigraphic criteria based on the age of the sites where site stress tensors are calculated with a best-fit stress inversion method. The present study calculates bulk (areal or multisite) stress tensors from fault-slip data published in the Chaling-Yongxing Basin (CYB) in central South China with the Tensor Ratio Method (TRM). These tensors are compared with published site stress tensors to examine whether bulk or site stress tensors define regional or local stress regimes and similar or not paleostress history. Two regional stress regimes for the Late Cretaceous-Paleogene period, describing an older Late Cretaceous stage with transpression-strike-slip (TRP-SS) tectonics (NNE-SSW contraction and WNW-ESE extension) and a younger Paleogene stage with radial-pure (RE-PE) extensional tectonics (WNW-ESE extension), are defined. These stages are interpreted to be transitive through a transtension (TRN) tectonics of similar WNW-ESE extension and responsible for the formation and evolution of the CYB under tectonic processes related to the India-Asia collision and the retreat of the (Paleo)Pacific plate. The present analysis shows that tectonostratigraphic criteria based on the age of the exposed rocks might be insufficient for the coherent correlation of stress tensors resolved in sites of limited size and, thus, for unraveling the paleostress history of a region.

Wet deposition of polycyclic aromatic hydrocarbons in a remote area of Central South China from 2014 to 2017

AbstractIn recent years, there has been a notable increase in the consumption of fossil energy, leading to a significant rise in environmental pollution, particularly in China due to its rapid development. This has resulted in the frequent occurrence of large‐scale fog and haze weather, highlighting the urgent need for environmental protection measures. To gain insights into the atmospheric conditions in China, an analysis was conducted on the wet deposition of polycyclic aromatic hydrocarbons (PAHs) in a remote region of Central South China from 2014 to 2017. The study revealed that the average concentrations and peak values of Ʃ16PAHs in 2014 and 2015 were considerably higher than those observed in 2016 and 2017. Furthermore, it was found that five‐ring PAH species were the predominant components during 2014 and 2015, indicating a shift in the main sources of PAHs. The peaks of Ʃ16PAHs were predominantly detected in samples collected during light rain in the winter, specifically on days without heavy rainfall. This can be attributed to the absence of heavy rain, which would otherwise reduce the concentration of air pollutants. Consequently, contaminants accumulated in the air are easily enriched in rainwater. The concentrations of Ʃ15Alkyl‐PAHs also exhibited a significant correlation with the number of rainfall days. Notably, a much higher annual average concentration of Ʃ15Alkyl‐PAHs was observed in 2017, which experienced fewer rainfall days. Coal combustion, petroleum sources, and vehicular emissions accounted for 58%, 12%, and 30% of the PAHs in the air, respectively. Despite improvements in air quality in China since 2016, it is crucial to address the elevated concentrations of PAHs in the atmosphere, particularly under adverse meteorological conditions characterized by reduced rainfall.

Length-Weight Relationships of Four Fish Species from the Dongting Lake Basin, Central South China

Length-weight relationships (LWRs) were described for four fish species inhabiting the tributaries of the Dongting Lake, China. Fish were sampled using stationary gillnets (50 m long × 2.0 m high and mesh size: 2, 6, 10, and 14 cm) and lobster pots (18 m long × 0.33 m high × 0.45 m width and mesh size: 1 cm) twice a year from May 2021 to July 2023. All fishes were measured in the field immediately after collection for total length (L) to the nearest 0.1 cm and body weight (W) to the nearest 0.1 g. There was a strong correlation between total length and weight in all four species (r2 > 0.98). The values of parameter b in LWR ranged from 2.9709 to 3.4373. The LWR of Sinilabeo tungting, Acrossocheilus jishouensis, Onychostoma rara, and Onychostoma barbata provide new data for https://Fishbase.org and can be useful for establishing conservation measures of fish resources after fishing closure in the Dongting Lake basin, China.

Intensification of compound temperature extremes by rapid urbanization under static and dynamic Urban-rural division: A comparative case study in Hunan Province, Central-South China

Climate extremes, notably compound extremes, pose significant risks to human society and environmental systems. These extremes, heightened by urbanization—a hallmark of modern socioeconomic progression—inflict persistent, intense thermal conditions. The comprehension of urbanization's impact on compound temperature extremes, particularly in Central-South China, a region with rapid urbanization and a subtropical climate, remains limited. In addition, most existing studies relied on static urban-rural division, and few used dynamic division, with no research yet juxtaposing findings from both methods. Against this backdrop, this study provided an unprecedented assessment of urbanization's impact on both individual and compound temperature extremes in Central South China, focusing on Hunan Province during long-time period of 1960–2022 under both static and dynamic urban-rural divisions. In both urban and rural stations, a pronounced warming trend was evident across individual and compound temperature extremes. Besides, a tendency of independent day/night extremes shifting towards extremes spanning both was observed. Notably, the escalation of heat compound extreme temperature indices (ETIs) outpaces that of cold ones, with a larger urban-rural discrepancy under dynamic classifications. Urbanization intensifies temperature extremes, particularly affecting the reduction of independent cold days (30.97 %–33.94 %) and the increase in compound hot events (23.91 %–24.87 %). Interestingly, urbanization's impact is more substantial on independent daytime extremes than on independent nighttime ones. Urbanization's influence on ETIs was consistently observed under both static and dynamic classifications, with the latter revealing a more pronounced contribution (1 %–3 %), and the contribution to compound ETIs is 6 %–8 % higher than to individual ETIs. These findings emphasize the importance of considering urbanization's multifaceted impacts on climate strategies and underscore the need for adaptive infrastructure and sustainable practices to mitigate escalating climate risks.

Mutation and clinical analysis of the CLCC1 gene in amyotrophic lateral sclerosis patients from Central South China.

Recently, chloride channel CLIC-like 1 (CLCC1) was reported to be a novel ALS-related gene. We aimed to screen CLCC1 variants in our ALS cohort and further explore the genotype-phenotype correlation of CLCC1-related ALS. We screened rare damaging variants in CLCC1 from our cohorts of 1005 ALS patients and 1224 healthy controls with whole-exome sequencing in Central South China. Fisher's exact test was conducted for association analysis at the entire gene level and single variant level. In total, four heterozygous missense variants in CLCC1 were identified from four unrelated sporadic ALS patients and predicted to be putative pathogenic by in silico tools and protein model prediction, accounting for 0.40% of all patients (4/1005). The four variants were c.A275C (p.Q92P), c.G1139A (p.R380K), c.C1244T (p.T415M), and c.G1328A (p.R443Q), respectively, which had not been reported in ALS patients previously. Three of four variants were located in exon 10. Patients harboring CLCC1 variants seemed to share a group of similar clinical features, including earlier age at onset, rapid progression, spinal onset, and vulnerable cognitive status. Statistically, we did not find CLCC1 to be associated with the risk of ALS at the entire gene level or single variant level. Our findings further expanded the genetic and clinical spectrum of CLCC1-related ALS and provided more genetic evidence for anion channel involvement in the pathogenesis of ALS, but further investigations are needed to verify our findings.

Pathogenicity of novel hantavirus isolate and antigenicity and immunogenicity of novel strain-based inactivated vaccine

BackgroundHantaan virus (HTNV, Orthohantavirus hantanensae species, Hantaviridae family) is the main etiological agent responsible for hemorrhagic fever with renal syndrome (HFRS). The novel HTNV may pose a potential danger to the control and prevention of HFRS in China, which highlights the importance of vaccine development in public health management. In previous studies, our laboratory discovered and successfully isolated a new HTNV strain, HV004 strain, from Apodemus agrarius captured in an epidemic area in Hubei, China. MethodsAn initial biological and pathogenicity characterization of HTNV 76–118 (standard train), HV114 strain (a clinical isolate from Hubei province in 1986), and the novel isolate HV004 strain from the epidemic areas of Hubei province were performed in susceptible cells and in vivo. An experimental HV004 strain inactivated vaccine was prepared, and its corresponding immunogenicity was analyzed in BALB/c mice. ResultsHV004 strain had a similar but higher pathogenicity than HTNV 76–118 and HV114 in suckling mice. A subcutaneous vaccination (s.c.) with the inactivated HTNV vaccine adjuvanted with aluminum, followed by a challenge intraperitoneally with 106 FFU/ml HTNV, afforded full protection against an HTNV challenge. All immunized mice in every group elicited serum neutralizing antibodies with increasing dosages, which may protect mice from HTNV infection. A dose-dependent stimulation index of splenocytes was also observed in immunized mice. The percentage of IFN-γ-producing CD3+CD8+ T cells was significantly higher in the spleens of immunized mice than in those of control mice. ConclusionsThese findings suggest that the inactivated HTNV vaccine may stimulate mice to produce high levels of antibodies with neutralization activity and elicit specific anti-HTNV humoral and cellular immune responses in BALB/c mice against the prevalent strain of HTNV in south central China.

Assessing the suitability and dynamics of three medicinal Sambucus species in China under current and future climate scenarios.

Climate change exerts profound influences on the ecological environments on a global scale, leading to habitat destruction and altering distribution patterns for numerous plant species. Traditional Chinese medicinal plants, such as those belonging to the Sambucus genus, have been extensively utilized for several centuries to treat fractures, rheumatism, and inflammation. However, our understanding of their geographic distribution and climatic adaptation within China still needs to be improved. In this study, we screened the optimal predictive model (random forest model) to predict the potential suitable distribution of three Sambucus species (Sambucus adnata, Sambucus javanica, and Sambucus williamsii) across China under both current and future climate scenarios. Moreover, we identified key climate factors that influence their potential distributions. Our findings revealed that S. adnata and S. javanica are predominantly shaped by temperature seasonality and mean diurnal range, respectively, whereas S. williamsii is significantly affected by the precipitation of the wettest month. Currently, S. williamsii is primarily distributed in north and central south China (covering 9.57 × 105 km2), S. javanica is prevalent in the south and east regions (covering 6.41×105 km2), and S. adnata predominantly thrives in the southwest China (covering 1.99×105 km2). Under future climate change scenarios, it is anticipated that S. adnata may migrate to higher latitudes while S. javanica may shift to lower latitudes. However, potentially suitable areas for S. williamsii may contract under certain scenarios for the years 2050 and 2090, with an expansion trend under the SSP585 scenario for the year 2090. Our study emphasizes the importance of climatic variables in influencing the potential geographic distribution of Sambucus species. These findings provide valuable theoretical insights for the preservation, cultivation, and utilization of Sambucus medicinal plant resources in the context of ongoing climate change.

Spatiotemporal exploration of ecosystem service value, landscape ecological risk, and their interactive relationship in Hunan Province, Central-South China, over the past 30 years

Ecosystem services and ecological risk prevention are important factors that influence for sustainable socio-economic development. In recent years, fewer studies, and practices have been conducted on the value of ecosystem services and ecological risk management in larger regions, and the mechanisms of their interactions have not been adequately investigated. The central southern region of China is in a stage of high-quality development, and Hunan Province in this region is used as an example to investigate the interaction mechanism between ecosystem service value (ESV) and landscape ecological risk (LER)as well as to generate new ideas for coordinated and sustainable regional socioeconomic development. This study developed an evaluation model of ESV and LER by synthesizing multi-source data of Hunan Province from 1990 to 2020 and further revealed the interaction mechanism between ESV and LER. We found the following: (1) Hunan Province experienced rapid urbanization, and both ESV and LER showed increasing trends. A complex and significant positive correlation was observed between these two variables. (2) The ESV in Hunan Province showed an overall increasing trend from 1990 to 2020, and each level of ESV was distributed from high to low, with the core of the high value area spreading outward. ESV gradually decreased after 2010, when urban expansion was rapid. (3) The LER level in Hunan Province shifted from medium-low risk to high risk, the risk level gradually increased, and the overall distribution pattern of each level was high in the north and south and low in the surroundings. (4) There were four types of spatial correlations at the local scale: high value and high risk, high value and low risk, low value and high risk, and low value and low risk. Based on these results, an ecological risk prevention zoning plan was developed for Hunan Province. This study contributes to understanding of the interactive and synergistic relationship between ESV and LER in Hunan Province, which is critical for optimizing sustainable economic and social development.

Spatiotemporal Pattern Evolution of Food and Nutrient Production in China.

Ensuring food and nutrient supply is a crucial aspect of achieving food safety. With rapid population growth, urbanization, and social and economic development, the challenges related to China's food and nutrient production have become increasingly prominent. This paper analyzed the characteristics of the spatiotemporal pattern evolution of food and nutrient production in China from 1995 to 2020, utilizing the conversion of various food nutrients and the establishment of a gravity center model. The results showed that: (1) Food production exhibited increasing trends in China, six regions, and 90% of the provinces. Notably, the structure of food production underwent significant changes in China, East China, Central-South China, Southwest China, Northwest China, and 60% of the provinces. (2) The output of all categories of food nutrients demonstrated increasing trends in China, six regions, and most provinces. At three different geographical scales, the changes of six food nutrients production structure showed significant differences. (3) Natural, political, social, economic, and technological factors played pivotal roles in influencing the gravity centers of food and nutrient production in China. The gravity centers of cereal production shifted northeast, while those of root and tuber, oil crops, and stimulants production moved westward. Additionally, the gravity centers of sugar crop, pulse, vegetable, fruit, and aquatic product production moved southwest and those of livestock and poultry production shifted northward. (4) Affected by the food production, the gravity centers of food energy, food protein, and food carbohydrate production shifted northward, while those of food fat, food vitamins, and food minerals production shifted northwest, southwest, and westward, respectively. The results of this study are of great significance for policy adjustments pertaining to the distribution pattern of food production, food security stability, and sustainable development in China.

The Driving Effects of the Total Water Use Evolution in China from 1965 to 2019

To understand the influence mechanism of the total water use evolution in a certain region more deeply, it is necessary to accurately identify the driving effects of the total water use evolution, and quantitatively analyze the influence of the driving effects on the total water use evolution. In this research, we studied the driving effects of the total water use evolution in China from the perspective of multi-year long time-series in the whole country for the first time. Through the logarithmic mean Divisia index (LMDI) decomposition method, we constructed an LMDI decomposition model for the regional total water use evolution, and decomposed the total water use evolution in China and its five stages from 1965 to 2019 into the water use intensity effect (WUIE), sector proportion effect (SPE), per capita total economy effect (PCTEE), and total population effect (TPE). We also considered the driving effects of the total water use evolution when the population or economic proportion changed in the six major districts in China for the first time. Based on the LMDI decomposition method, we separately added the district population proportion variable and the district economic proportion variable to contrast a logarithmic mean Disivia index-population (LMDI-P) decomposition model and a logarithmic mean Divisia index-economic (LMDI-E) decomposition model for the regional total water use evolution. Compared with the LMDI decomposition model, the district population proportion effect (DPPE) and the district economic proportion effect (DEPE) were separately added. We calculated the value and proportion of the driving effects of the total water use evolution in China and analyzed their influence mechanisms. Our findings provide better decision-making reference for water resource planning and management in China. The results show the following: (1) According to the overall situation from 1965 to 2019, the prohibitive role played by the PCTEE (total 22,263.79 × 108 m3) and the TPE (total 2945.38 × 108 m3) with respect to the total water use increasing in China offset the inhibitive role played by the WUIE (total −16,094.31 × 108 m3) and the SPE (total −5930.02 × 108 m3) with respect to the total water use increasing in China; (2) According to the overall situation from 1965 to 2019, both the DPPE and DEPE had heterogeneity in the total water use evolution in the six major districts in China. The DPPE played a prohibitive role in the three population inflow districts (Southeast China, Central South China, and Northwest China) with respect to the total water use increasing (total 291.09 × 108 m3), and an inhibitive role in the other three population outflow districts (North China, Central South China, and Southwest China) with respect to the total water use increasing (total −207.78 × 108 m3). The DEPE played a prohibitive role in the three economically developed districts (North China, Southeast China, and Central South China) with respect to the total water use increasing (total 428.26 × 108 m3), and an inhibitive role in the other three economically underdeveloped districts (Northeast China, Southwest China, and Northwest China) with respect to the total water use increasing (total −477.74 × 108 m3).

The efficiency evaluation and the spatiotemporal differences of CO2 emissions in China's construction industry

Under the promotion of China's double carbon policy, China's construction industry (CI) is facing the pressure for CO2 emissions (CE) reduction. In order to promote China's high-quality green development, CO2 emissions efficiency (CEE) evaluation in China's CI was crucial. Based on the super-efficiency slacks-based measure–data envelopment analysis (SBM-DEA) model, the Global Malmquist-Luenberger (GML) index, the global and local Moran index in spatial autocorrelation, 11 indicators of CI were selected to evaluate CEE and the spatiotemporal differences of CEE in China's CI 31 provinces from 2000 to 2020 were analyzed. The results indicated the CEE was on the rise on the whole. The average annual CEE of Hainan, Heilongjiang, Tianjin, Shanghai and Xizang was bigger than 1. The CEE of Sichuan, Gansu and Guizhou was around 0.5. The order of CE of CI in China from high to low Was South China, North China, Northeast China, Central China, East China, Northwest China and Southwest China. The GML index increased by 6.25% annually, the average annual TC increased by 11.68%, and the average annual EC increased by 5.21%. The overall CEE of China's CI showed a positive correlation between 2010 and 2015, but the spatial agglomeration was weak.

Pangenome analysis provides insight into the evolution of the orange subfamily and a key gene for citric acid accumulation in citrus fruits.

The orange subfamily (Aurantioideae) contains several Citrus species cultivated worldwide, such as sweet orange and lemon. The origin of Citrus species has long been debated and less is known about the Aurantioideae. Here, we compiled the genome sequences of 314 accessions, de novo assembled the genomes of 12 species and constructed a graph-based pangenome for Aurantioideae. Our analysis indicates that the ancient Indian Plate is the ancestral area for Citrus-related genera and that South Central China is the primary center of origin of the Citrus genus. We found substantial variations in the sequence and expression of the PH4 gene in Citrus relative to Citrus-related genera. Gene editing and biochemical experiments demonstrate a central role for PH4 in the accumulation of citric acid in citrus fruits. This study provides insights into the origin and evolution of the orange subfamily and a regulatory mechanism underpinning the evolution of fruit taste.

Projections of mortality risk attributable to short-term exposure to landscape fire smoke in China, 2021–2100: a health impact assessment study

Landscape fire smoke, including smoke from all vegetation burning in natural and cultural landscapes, remains a threat to the health of the population. However, the future health impacts of landscape fire smoke in China have not been sufficiently investigated. We aimed to estimate the mortality risk attributable to landscape fire-related PM2·5 under different scenarios. In this health impact assessment study, we used the projected population and landscape fire-related PM2·5 concentration to calculate deaths attributable to short-term exposure to landscape fire smoke PM2·5 during 2021-2100. We did the analysis in three defined future periods: 2021-40 (near term), 2051-70 (medium term), and 2081-2100 (long term), with 1986-2005 as the historical period. We used fire-specific short-term epidemiological functions with the regional parameters specific to China. We assessed the mortality risks of landscape fire-related smoke and further identified their spatiotemporal distribution under two shared socioeconomic pathway (SSP) scenarios: SSP1-2·6, an optimistic scenario with strict control of carbon emissions, and SSP2-4·5, an intermediate scenario with weaker control of carbon emissions. The national mortality rate attributable to short-term exposure (ie, a few days) to landscape fire-related PM2·5 is projected to increase compared with historical values. The national deaths attributable to landscape fire smoke PM2·5 could peak in 2021-40, with increases of 28·10% (95% CI 14·08-53·11) under the SSP1-2·6 scenario and 37·38% (14·08-53·11) under the SSP2-4·5 scenario. Deaths would then decrease slightly during 2051-70 and 2081-2100. The provinces with the highest projected number of deaths attributable to landscape fire-related PM2·5 are located in east and south-central China, and those with the largest percentage increase in projected deaths are located in northwest and southwest China. Our results suggest that global warming could increase the contribution of landscape fire smoke to the total PM2·5 concentration, leading to an increase in the mortality rate in China. Our findings could help policy makers implement effective interventions in hotspot areas during different periods to reduce the impact of landscape fire smoke on human health. The National Natural Science Foundation of China, National Key Research and Development Program of China, and the Wellcome Trust.

Authenticating the geographic origins of Atractylodes lancea rhizome chemotypes in China through metabolite marker identification.

Atractylodes lancea is widely distributed in East Asia, ranging from Amur to south-central China. The rhizome of A. lancea is commonly used in traditional Chinese medicine, however, the quality of products varies across different regions with different geochemical characteristics. This study aimed to identify the chemotypes of A. lancea from different areas and screen for chemical markers by quantifying volatile organic compounds (VOCs) using a targeted metabolomics approach based on GC-MS/MS. The A. lancea distributed in Hubei, Anhui, Shaanxi, and a region west of Henan province was classified as the Hubei Chemotype (HBA). HBA is characterized by high content of β-eudesmol and hinesol with lower levels of atractylodin and atractylon. In contrast, the Maoshan Chemotype (MA) from Jiangsu, Shandong, Shanxi, Hebei, Inner Mongolia, and other northern regions, exhibited high levels of atractylodin and atractylon. A total of 15 categories of VOCs metabolites were detected and identified, revealing significant differences in the profiles of terpenoid, heterocyclic compound, ester, and ketone among different areas. Multivariate statistics indicated that 6 compounds and 455 metabolites could serve as candidate markers for differentiating A. lancea obtained from the southern, northern, and Maoshan areas. This comprehensive analysis provides a chemical fingerprint of selected A. lancea. Our results highlight the potential of metabolite profiling combined with chemometrics for authenticating the geographical origin of A. lancea.

Characteristics and reduction assessment of GHG emissions from crop residue open burning in China under the targets of carbon peak and carbon neutrality

Driven by the goal of carbon peak and carbon neutrality, greenhouse gas (GHG) emissions from the crop residue open burning (CROB) in China cannot be ignored. In this study, we have established a high-resolution (0.05° × 0.05°) GHG emissions inventory (including CO2, CH4, and N2O) of CROB from 2012 to 2021 in China based on the VIIRS data and official statistics. To improve the results accuracy, we compared the two commonly used bases for grid allocation, fire counts (FC) and fire radiative power (FRP), in the construction of high-resolution inventory. In 2012, GHG emissions are overestimated by 599 t CO2e per grid on average in 24,577 grids, and underestimated by 1096 t CO2e per grid on average in 13,546 grids based on FC compared to FRP. Then, we characterized the spatial and temporal distribution of GHG emissions from CROB by using the FRP-based method. From 2012 to 2021, total GHG emissions from CROB in China have decreased by 31.2 %, of which the East and South-Central China contributed 22.51 and 9.12 Tg CO2e of GHG reductions, while the Northeast China contributed 10.73 Tg CO2e of GHG growth, respectively. In addition, GHG emissions from CROB on the time scale are mainly concentrated in April, June, and October, with variations between years and regions influenced by the policy, climate, and farmers' perceptions. Finally, we assessed the GHG emission reductions from CROB under different scenarios in the future. By 2060, GHG emissions would be significantly reduced by 57.3 %–77.9 % compared to 2021 under effective control measures. We believe the results will be of great significance for GHG policy formulation and emission reduction potential assessment.

Diversity in the quasi‐biweekly oscillation sources of the daily maximum temperature over South China during summer

AbstractThe summer daily maximum temperature (Tmax) over South China features obvious quasi‐biweekly oscillation (QBWO) and its QBWO sources mainly include three types. The first type is influenced by tropical and mid–high‐latitude antiphase coupling QBWO. Successive suppressed and enhanced convection, accompanying with anticyclonic and cyclonic anomalies, propagate northward from the northwest of the Philippines to South China. At the peak warm phase, an anomalous high dominates over South China and causes significant warming. Meanwhile, an anomalous low associated with a southeastward‐propagating wave train occurs to the north and leading to abnormal cooling in situ. The second type originates from the mid–high latitudes. Before the warm phase, an anomalous high around the Ural Mountains triggers two wave trains propagating southeastward along the great circle route and eastward along the westerly jet, respectively, favouring an anomalous high over North–Northeast China. At the peak warm phase, the anomalous high extends southward, causing significant warming over South–Central China. The third type is influenced by tropical and mid–high‐latitude in‐phase coupling QBWO. The tropical anomalies are similar to the first type but the convection anomalies are centred to the northeast of the Philippines and propagate northwestward. The mid–high‐latitude wave trains are similar to the second type but with relatively weaker southeastward‐propagating wave train. At the peak warm phase, the anomalous highs from the Tropics and mid–high latitudes together dominate a large meridional scope and induce wide‐range warming over eastern China. Intrinsically, the QBWO of the convection north of the Philippines and mid–high‐latitude wave trains are important signals of the atmospheric variability and might be applied to the forecast of South China Tmax.