Province South China Research Articles

Comparative Analysis of Saponins from Different Phytolaccaceae Species and Their Antiproliferative Activities.

The quality and the efficacy of herbal medicine are of great concern especially with the increase in their global use. Medicinal plants of different species or collected from different geographical regions have shown variations in both their contents and pharmacological activities due to the differences in the environmental conditions of the collected sites. In this study, roots of Phytolacca acinosa found in different provinces in south China (Sichuan and Shandong) and a species of Phytolacca americana were investigated. To ensure a maximum yield of the major compounds, the extraction method and conditions were optimized. The preeminent method of extraction in this analysis was determined to be the ultrasound-assisted method with specific conditions as follows: ethanol-H2O (1:1, v/v), with a solvent: sample ratio of 1:8, and extraction was performed 3 times, each for 30 min. Under these conditions, samples from the different regions varied both in quantity and quality via the LC-MS analysis. A total of 60 triterpenoid saponins were detected within the three samples, among which 22 were identified as common in the three samples. The amounts of these common triterpenoid saponin identified varied across the samples. Moreover, the analysis led to the detection of some novel compounds that have not yet been reported in this family, while other compounds differ in their fragmentation pathways compared to previous literature. To further divulge the correlations between the bioactivities in these three samples and the quantity and quality of their bioactive components, a cytotoxic analysis was thus carried out with two cancer cell lines, and SGC-7901 and Hep G2, which evidently showed remarkable differences in their anti-proliferative activities with respect to the IC50 value. Samples of P. acinosa from Sichuan showed higher values in both cell lines (27.20 ± 1.60 and 25.59 ± 1.63 µg/mL) compared to those of Shandong and P. americana. For the first time, analysis and comparison of both interspecies and of different species in this family were carried out. This study will significantly contribute to the quality insurance of herbal medicine, especially in the Phytolaccaceae family.

A new genus of Cryphonectriaceae isolated from Lagerstroemia speciosa in southern China

Numerous species in the Cryphonectriaceae have been recorded on the Myrtales and many of these are economically important pathogens of Eucalyptus. Some species have also recently been shown to be endophytes of native Myrtaceae and to have undergone host jumps to infect Eucalyptus species established as exotics in plantations. Recent surveys in the GuangDong and HaiNan Provinces of South China reveal the presence of a species of Cryphonectriaceae associated with cankers on trees of Lagerstroemia speciosa (Lythraceae, Myrtales). Fungal structures were observed on the surface of dead bark covering cankers and on branch stubs. Multigene phylogenetic analyses were conducted based on DNA sequence comparisons of the partial LSU gene, ITS region of the nuclear ribosomal RNA gene and two regions of the β‐tubulin (BT) gene. The results revealed the presence of a previously undescribed genus and species in the Cryphonectriaceae. The fungus is described here as Chrysomorbus lagerstroemiae gen. et sp. nov. Inoculation tests showed that it is an aggressive pathogen on L. speciosa and that it can also infect Eucalyptus.

The Triassic to Early Jurassic palynological record of the Tarim Basin, China

The Tarim Basin, located in northwestern China, is an important oil-bearing region, and the extensive non-marine Mesozoic successions make this a key location for understanding environmental changes through the Triassic and Jurassic. Palynological analyses on samples from Lunnan-1 and Tazhong-1 drill cores from the northern and central part of the Tarim Basin reveal well-preserved spore–pollen assemblages. Five palynological assemblages, i.e. Tarim Triassic 1 (TT1)–Tarim Triassic 4 (TT4) and Tarim Jurassic 1 (TJ1), spanning the Early Triassic to Early Jurassic were identified based on compositional changes, which are supported by ordination of samples using non-metric multidimensional scaling (NMDS). The Early Triassic assemblages possess abundant bryophytes and Densoisporites spp.-producers, which potentially represent a recovery succession following the end-Permian event. The Late Triassic spore–pollen assemblages are more similar to those of the North China Palynofloral Province compared to the South China Province. Based on our phytogeographic analysis, we propose that the western section of the boundary between the North and South China palynofloras should be placed at the southern margin of the Tarim Basin.

Prospectivity mapping for “Zhuxi-type” copper-tungsten polymetallic deposits in the Jingdezhen region of Jiangxi Province, South China

The Zhuxi deposit is the largest copper-tungsten polymetallic deposit in the world and is in Jiangxi Province in South China. The ore body is characterized by hydrothermal-vein deposits of copper, lead, and zinc minerals at shallow levels, skarn deposits of tungsten and copper minerals at middle levels, and altered-granite-hosted copper and tungsten minerals at depth. Such metallogenic systems are typically intrusion-related. The intrusive granites related to the Zhuxi polymetallic deposit have been dated at 152.9Ma to 146.9Ma. The intrusions provided the thermal energy and the source material for the ore mineralization. Skarns mineralization, the main type of ore mineralization, developed in the contact zone of Carboniferous-Permian formations with the granites. Nappe structures changed the dip of the ore bodies from steep in the top part to gentle in the bottom. NE-trending faults provided the fluid pathways and controlled the geological framework and distribution of ore deposits on a regional scale. In this study, recognition exploration criteria were analyzed based on a mineral deposit model and the geological setting. Extraction of favorable geological information and GIS-based data-integration methods were used for mineral-prospectivity mapping of Zhuxi-type polymetallic deposits. Buffering analysis was employed to extract structural information (e.g. faults) and lithologic or stratigraphic information (e.g. granites or geologic units). The singularity method and spatially weighted principal component analysis were used to enhance and delineate geochemical anomalies. The derivative norm was utilized to extract magnetic-gradient anomalies associated with intrusive granites. Student t-test of weights-of-evidence (WofE) proved to be an effective way to optimize threshold values for binarization of variables as evidence layers by evaluating the spatial correlation between known deposits and geological variables. The posterior probabilities of WofE gave a relative estimation of mineralization potential. Areas delineated by high posterior probability had much higher potentiality for the discovery of new deposits where had none had been found yet.

ABO blood groups and risk of deep venous thromboembolism in Chinese Han population from Chaoshan region in South China.

Objectives:To demonstrate the prevalence of ABO blood groups with deep venous thromboembolism in Chinese Han population.Methods:A retrospective study was conducted between January 2010 and March 2015 in The First Affiliated Hospital of Shantou University Medical College in Chaoshan District of Guangdong Province in South China. Eighty nine patients with confirmed diagnosis of deep venous thromboembolism were included. Frequency of blood groups was determined.Results:Of 89 patients with deep venous thromboembolism, 28 patients had blood group A (31.5%), 28 patients had blood group B (31.5%), 13 patients had blood group AB (14.6%), and 20 patients had blood group O (22.5%). Compared with O blood type, the odds ratios of deep venous thromboembolism for A, B and AB were 2.23 (95% CI, 1.27-3.91), 2.34 (95% CI, 1.34-4.09) and 4.43 (95% CI, 2.24-8.76).Conclusion:There is a higher risk of venous thromboembolism in non-O blood groups than O group.

Geology, geochronology, geochemistry and ore genesis of the Wangu gold deposit in northeastern Hunan Province, Jiangnan Orogen, South China

The Wangu gold deposit in northeastern Hunan, South China, is one of many structurally controlled gold deposits in the Jiangnan Orogen. The host rocks (slates of the Lengjiaxi Group) are of Neoproterozoic age, but the area is characterized by a number of Late Jurassic–Cretaceous granites and NE-trending faults. The timing of mineralization, tectonic setting and ore genesis of this deposit and many similar deposits in the Jiangnan Orogen are not well understood. The orebodies in the Wangu deposit include quartz veins and altered slates and breccias, and are controlled by WNW-trending faults. The principal ore minerals are arsenopyrite and pyrite, and the major gangue minerals are quartz and calcite. Alteration is developed around the auriferous veins, including silicification, pyritic, arsenopyritic and carbonate alterations. Field work and thin section observations indicate that the hydrothermal processes related to the Wangu gold mineralization can be divided into five stages: 1) quartz, 2) scheelite–quartz, 3) arsenopyrite–pyrite–quartz, 4) poly-sulfides–quartz, and, 5) quartz–calcite. The Lianyunshan S-type granite, which is in an emplacement contact with the NE-trending Changsha-Pingjiang fracture zone, has a zircon LA-ICPMS U–Pb age of 142±2Ma. The Dayan gold occurrence in the Changsha-Pingjiang fracture zone, which shares similar mineral assemblages with the Wangu deposit, is crosscut by a silicified rock that contains muscovite with a ca. 130Ma 40Ar–39Ar age. The gold mineralization age of the Wangu deposit is thus confined between 142Ma and 130Ma. This age of mineralization suggests that the deposit was formed simultaneously with or subsequently to the development of NE-trending extensional faults, the emplacement of Late Jurassic–Cretaceous granites and the formation of Cretaceous basins filled with red-bed clastic rocks in northeastern Hunan, which forms part of the Basin and Range-like province in South China. EMPA analysis shows that the average As content in arsenopyrite is 28.7 atom %, and the mineralization temperature of the arsenopyrite–pyrite–quartz stage is estimated to be 245±20°C from arsenopyrite thermometry. The high but variable Au/As molar ratios (>0.02) of pyrite suggest that there are nanoparticles of native Au in the sulfides. An integration of S–Pb–H–O–He–Ar isotope systematics suggests that the ore fluids are mainly metamorphic fluids originated from host rocks, possibly driven by hydraulic potential gradient created by reactivation of the WNW-trending faults initially formed in Paleozoic, with possible involvement of magmatic and mantle components channeled through regional fault networks. The Wangu gold deposit shares many geological and geochemical similarities as well as differences with typical orogenic, epithermal and Carlin-type gold deposits, and may be better classified as an “intracontinental reactivation” type as proposed for many other gold deposits in the Jiangnan Orogen.

Medical Discrimination Affects the HIV/AIDS Epidemic Control: A Study of Self-Perceived Medical Discrimination on People Living with HIV or AIDS.

People living with HIV or AIDS (PLWHA) experienced severe medical discrimination which is seriously affecting their lives. However, few studies examined the epidemic characteristics of self-perceived medical discrimination from the discrimination objects such as PLWHA. Therefore, we aimed to investigate the epidemiological status and analyze the influential factors of the self-perceived medical discrimination on PLWHA in South China. The self-designed questionnaire was used to investigate the medical discrimination status of the 443 infected persons, who were randomly recruited from the representative AIDS designated hospitals in Guangdong Province in South China. The results showed that 49.0% of PLWHA experienced medical discrimination, and 55.3% received discriminatory treatment, 48.4% experienced refusal of treatment, 36.4% had private information leaked and 12.9% received mandatory test. However, 52.2% patients chose to endure discrimination in silence. Compared with the Asymptomatic HIV-infected patients, AIDS patients perceived more medical discrimination. The Logistic regression analysis indicated that PLWHA self-perceived medical discrimination status was influenced by 4 factors: the voluntary of first medical detection, the route of transmission, the stage of the disease and the familiarity with the HIV/AIDS-related law. Additionally, the two dimensions of the life quality scale were influenced by medical discrimination, namely, overall function and disclosure worry. Ultimately, our study provides a better understanding of the relationship between infection status, quality of life and the medical discrimination they experienced or perceived. It will help health professionals and policy makers to develop tailored behavioral and policy-oriented intervention strategies for PLWHA to tackle different types of medical discrimination in high-risk settings.

Trans-Abdominal Ultrasonography of Pancreas is Superior to Liver for Detection of Ectopic Fat Deposit Resulted from Metabolic Syndrome

Non-alcoholic fatty pancreas disease (NAFPD) is frequently found through trans-abdominal ultrasound examination. The incidence of NAFPD varied from 16% to 69.7% in different country. The aim of our study was to investigate the occurrence rate of NAFPD in a south China province of Fujian and the relations to non-alcoholic fatty liver disease(NAFLD) and metabolic parameters. A total of 256 subjects were recruited. Each was assessed by abdominal sonography to diagnose NAFLD and NAFPD. The ages, genders, heights, weights and detection of peripheral blood biochemical indexes (cholesterol, triglycerides, high-density lipoprotein cholesterol, low density lipoprotein cholesterol and glucose) were recorded. The relationships among metabolic parameters and NAFPD or NAFLD were evaluated, and the positive rates of NAFLD and NAFPD in the general population were compared. The age, BMI, holesterol, triglycerides, high-density lipoprotein cholesterol, low density lipoprotein cholesterol and glucose were significantly associated with NAFPD and NAFLD (P<0.05), while the positive rate of NAFPD was significantly higher than that of NAFLD. NAFPD and NAFLD can reflect the body metabolism, while NAFPD has a higher sensitivity.

Geochemistry, Sr–Nd–Pb–Hf isotopes systematics and geochronological constrains on petrogenesis of the Xishan A-type granite and associated W–Sn mineralization in Guangdong Province, South China

The Xishan deposit, located in the western Guangdong Province in South China, is a quartz-vein type W-Sn deposit with an average Sn grade of 0.1–0.4wt%. The deposit is temporally and spatially associated with Xishan alkali feldspar granite. The W–Sn mineralization is present mainly as veins that are hosted by the granite. In this paper we present new zircon U–Pb age, whole-rock geochemical data, Sr–Nd–Pb–Hf isotopic data and Re–Os age in order to constrain the nature and timing of magmatism and mineralization in the Xishan mining district with implications on geodynamic settings. LA–ICP–MS zircon U–Pb analyses yielded an age of 79.14±0.31Ma for the alkali feldspar granite, consistent with the molybdenite Re–Os age of 79.41±1.11Ma. The alkali feldspar granite shows high contents of SiO2 (71.52–76.25wt%), high total alkalis (Na2O+K2O=9.35–13.51wt%), high field strength elements (e.g. Zr=95.4–116ppm, Y=97.1–138ppm, Nb=36.1–55.5ppm, Ga=97.1–138ppm), and rare earth elements (total REE=171.8–194.0ppm) as well as high Ga/Al ratios (10,000×Ga/Al=3.23–3.82) suggesting that it has the geochemical characteristics of A-type granite and shows an A2 subtype affinity. Sr–Nd isotopes of the alkali feldspar granite show that (87Sr/86Sr)i values range from 0.7111 to 0.7183, and the εNd(t) values and Nd model ages (T2DM) vary from −6.8 to −6.5 and 1414 to 1433Ma, respectively. The Pb isotopic compositions are variable, with 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values ranging from 18.783 to 18.947, 15.709 to 15.722 and 38.969 to 39.244, respectively, indicating that the alkali feldspar granite was derived from a mantle-crust mixed source. In situ Hf isotopic analyses reveal that the alkali feldspar granite has εHf(t) values ranging from −9.69 to −0.04 and two-stage Hf model ages from 1145Ma to 1755Ma, indicating that the alkali feldspar granite was formed by the partial melting of Mesoproterozoic crusts of the Cathaysia Block with additions of mantle-derived materials. These results, together with previously presented regional geological relationships, suggest that the formation of the Xishan granite and associated W–Sn mineralization is related to lithospheric extension and asthenospheric upwelling that are attributed to a directional change of Pacific plate motion.

Epidemiology of hepatitis B virus infection: results from a community-based study of 0.15 million residents in South China.

Limited information is available about the current epidemic status of hepatitis B virus (HBV) in Guangdong province in South China, where hepatitis B is endemic. We sought to provide an up-to-date assessment of hepatitis B prevalence in a large population through a community-based study. A total of 169,211 local residents were recruited using the stratified cluster random sampling method from 2014 to 2015, and each participant’s information was collected using an interviewer-administered questionnaire. Accordingly, the prevalence of hepatitis B surface antigen (HBsAg) in the total population was 8.76%. HBsAg prevalence was lowest (0.29%) among children aged 0–12 years and highest (12.71%) among those aged 23–59 years. Moreover, the prevalence (8.82%) in males approximately equalled that (8.65%) in females (P > 0.05). Overall, vaccination was effective in preventing HBV infection, regardless of age. Among adults aged 23–59 years, male sex tended to keep the HBsAg persistence. However, reduced persistence for participants with occasional physical exercise and drinking was observed. For participants older than 59 years, a history of prior surgery placed people at high risk for infection. Although Guangdong has successfully decreased the HBsAg prevalence among children, it is urgent to expand vaccination to adults, and employ interventions to reduce the infection risk.

Intensity and diversity of internationalization among small and medium-sized exporters in China

PurposeThis study aims to gauge the interactive effect of export intensity and diversity on export performance among exporters in an emerging economy and explore the moderating effect of export intermediaries on the internationalization–export performance relationship.Design/methodology/approachA survey was undertaken among a convenience sample of small and medium exporters located in Guangdong and Fujian Provinces in South China.FindingsThe results show that intensity and diversity interact negatively with export performance, whereas the use of export agents registered a positive effect. Exporters pursuing a strategy of high export intensity will achieve better performance provided that these exports are concentrated in a few countries. Using export agents can help in enhancing the intensity–performance relationship but not that for diversity–performance.Practical implicationsChinese exporters are advised not to blindly pursue international expansion without regard to their own resources and capabilities. They should try to strike a balance between intensity and diversity and employ external agents when needed.Originality/valueThis research seeks to address the void in the literature on how export intensity and diversity should be balanced to create a positive effect on the performance of exporting ventures in an emerging economy, which is under-addressed in the literature. It is also found that employment of export intermediaries is not always good for export performance.

A study of causality structure and dynamics in industrial electricity consumption based on Granger network

Abstract Based on industrial electricity consumption, we model industrial networks by Granger causality method and MST (minimum spanning tree), and then further stick onto an industrial coupling mechanism from energy-consumption perspective. First, we construct Granger causality networks of five provinces in South China of GD, GX, GZ, HN and YN based on their industrial electricity consumption data, and we demonstrate from a network-topology perspective: the distribution of weight of links of all industrial electricity-consumption Granger causality networks approximately follows power-law distribution, revealing a phenomenon that few industries may bring a tremendous influence on the rest. Moreover, correlation analysis between weight and degree of a node shows that in most Granger causality networks, both span and strength of influence of a given industry will significantly increase. Further, we analyze the relationship between the thresholds of Granger causality significance and density of corresponding networks. Results show GD and HN could be classified into a group with relatively greater global differentiation in industries and unbalanced industrial development, however, GX, GZ and YN are grouped as second cluster with relatively balanced industrial development. Furthermore, using Chu–Liu–Edmonds MST algorithm, we extract graphs of MSTs or maximal cliques from industrial electricity-consumption Granger causality networks, and research on energy transmission structure, feedback loop, and bootstrap reliability. By analyzing MSTs, we find that only GD, GX and YN can be extracted with MST graphs, and capture the probable transmission routes of key nodes. Besides we illustrate all three MST graphs are involved with feedback loops structures with various characteristics: GX has complete feed-forward section, feed-back section and feedback loop section; YN has only feed-forward section and feedback loop section; GD has multiple feedback loops section. Finally, we conduct bootstrap reliability tests on MSTs. Results show branches of reliability of GD, GX and YN are decentralized while those feedback loops sections are only concentrated on highly-reliable branches. As neither HN nor GZ can be extracted with MST graphs, we characterize them by maximal cliques. It is demonstrated that both industrial systems of HN and GZ are significantly grouped into two independent branches and those internal industries inside independent branches are highly correlated. However from perspectives of whole South China, the causal relationship is only converged on a few of industries. For regions without MST graphs like HN and GZ, the reliability of links is also greater than that of GD, GX and YN.

Diagenetic overprint to a negative carbon isotope anomaly associated with the Gaskiers glaciation of the Ediacaran Doushantuo Formation in South China

Ediacaran carbon isotope records contain significant and long-lasting negative anomalies for which convincing explanations have not been given. We recognized a diagenetic overprint contributing to the 120-m-thick negative anomaly interval in the upper part of the Ediacaran Doushantuo Formation at Yangjiaping, Hunan province in South China. Coarse-grained carbonate facies deposited in an outer shelf setting of the Yangtze platform provided an opportunity to examine diagenetic components by measuring micro-drilled sub-samples. Scattered δ13C values of bulk samples (+5 to −14‰) in this anomaly interval are here attributed to the secondary precipitation of highly 13C-depleted (up to −33‰) calcite cement on dolomite sedimentary grains of less negative δ13C. This diagenetic overprint was not observed in the intervals above or below the anomaly. In these intervals the δ13C difference between the cements and the grains is insignificant. Strontium isotopic variation in the anomaly interval is identical to that of the interval with negative δ13C anomaly in the middle Doushantuo Formation reported from the Three Gorges area, which is presumably correlated with the Gaskiers glaciation. This correlation scheme indicates a long-term hiatus (∼35myrs) between the anomaly horizon and the overlying Dengying Formation at Yangjiaping. We suggest that the anaerobic oxidization of reduced carbon (organic carbon or methane) by sulfate reduction was the most likely process responsible for 13C-depleted secondary calcite, which progressively filled intergranular porosity. An increase in atmospheric oxygen during Ediacaran and the Gaskiers glaciation enhanced oxidative weathering and elevated seawater sulfate concentrations to a level sufficient for diagenetic alteration. This co-occurred with an increase in 87Sr/86Sr from 0.7080 to 0.7085 in middle Ediacaran. We also show that the δ13C profile of the Doushantuo Formation at Yangjiaping is similar to that at Weng’an in Guizhou province, another section recording an outer shelf depositional environment. Although further study is needed, correlation between the Yangjiaping Unit 3 with the δ13C-scattered interval in Weng’an suggests that the embryo-bearing phosphorites at Weng’an were formed likely before the Gaskiers glaciation.

Atmospheric icing status and type of southwest China networks

Transmission line disconnection, tower collapse and insulator flashover caused by icing seriously threaten power system security. Ice type and state of transmission lines, which vary a lot with terrain and climate, in typical areas such as Daqing-ridge, Yak Mountain and Erlang Mountain in Sichuan Province in South China were investigated in this paper. It is shown that mixed-phase ice with obvious layered structure, low density, strong adhesive force and windward-side growth is the main type of ice threatening the security of transmission lines and insulators. There is more ice on the ends of insulators than other areas in severe cases, where all sheds of the insulator is bridged by ice. Besides, temperature, humidity and precipitation intensity are main factors influencing the icing process. As a result, terrain and climate play a leading role in determination of icing type and severity.

Wind Structure of a Subtropical Squall Line in China: Results from Dual-Doppler Radar Data

A subtropical squall line moved from Guangxi to Guangdong province in South China on 23-24 April 2007, which resulted in gale and heavy precipitation. The three-dimensional (3D) wind field of the squall line in its mature period was retrieved by Guangzhou-Shenzhen dual-Doppler data. The 3D conceptual model of this squall line was proposed. On the horizontal plane, the storm-relative front-to-rear inflow prevailed at the lower altitudes of the leading edge. The rear-to-front cold inflow in the stratiform region was observed below 3 km height, which enhanced the convergence in the convective region. At the middle altitudes of the squall line, the front-to-rear horizontal flow prevailed. Strong updrafts were observed at the lower and middle altitudes of the leading edge. Some convergence centers were located at the lower altitudes of the convective region. Furthermore, the storm-relative flow in the vertical cross-section perpendicular to the squall line was revealed. The front-to-rear warm flow extended from the surface to 7.5 km altitude at the leading edge. Above it, part of the front-to-rear inflow blew upward and then forward, and the other part of the inflow blew backward. The descending rear-to-front cold flow was only seen below 3 km height in the stratiform region.

Carbon cycle perturbation expressed in terrestrial Permian–Triassic boundary sections in South China

Stable isotopes of inorganic and organic carbon are commonly used in chemostratigraphy to correlate marine and terrestrial sedimentary sequences based on the assumption that the carbon isotopic signature of the exogenic carbon pool dominates other sources of variability. Here, sediment samples from four Permian–Triassic boundary (PTB) sections of western Guizhou and eastern Yunnan provinces in South China, representing a terrestrial to marine transitional setting, were analyzed for δ13C of organic matter (δ13Corg). These values were subsequently compared to published δ13C values of carbonates (δ13Ccarb) from the Global Stratotype Section and Point at Meishan and many other marine and terrestrial sections. A similar isotopic trend evident through all four sections is characterized by a negative shift of 2–3‰ at the top of the Xuanwei Formation, where we tentatively place the PTB. This negative shift also corresponds to a turnover in the vegetation and the occurrence of fungal spores, which is generally interpreted as a proliferation of decomposers and collapse of complex ecosystems during the end-Permian mass extinction event. Moreover, the absolute values of δ13Corg are more extreme in the more distal (marine) deposits. The δ13Corg values for the studied sediments are more variable compared to coeval δ13Ccarb records from marine records especially in the interval below the extinction horizon. We contend that the depositional environment influenced the δ13Corg values, but that the persisting geographic δ13Corg pattern through the extinction event across the four independent sections is an indication that the atmospheric δ13C signal left an indelible imprint on the geologic record related to the profound ecosystem change during the end-Permian extinction event.

Characteristics of Lasiodiplodia theobromae from Rosa rugosa in South China

Rosa rugosa Thunb., one of the most important cut flower crops in China, is mainly planted in the southern regions of this country. Lasiodiplodia species include pathogens of a wide variety of plant and cover a wide geographic distribution. Recently, canker disease caused by species of Lasiodiplodia was observed on R. rugosa branches in GuangDong Province in South China. Based on sequence comparisons for the ITS rDNA and translation elongation factor 1 alpha (TEF-1α) gene region, and combined morphological characteristics, the Lasiodiplodia isolates from diseased R. rugosa branches were identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl. Pathogenicity tests showed that L. theobromae was virulent to R. rugosa. To our knowledge, this is the first report of L. theobromae infecting Rosa in China.

Optimizing Tapping-Tree Density of Rubber (Hevea brasiliensis) Plantations in South China

Tapping-tree density in rubber plantations affects the production of dry rubber. Farmers can estimate rubber productivity when they know with certainty the number of tapping trees within a plantation and can therefore increase productivity through optimized planting schematics. Historical data on planting distance between trees and between rows, planting density (trees/ha) and tapping-tree density (number of trees under tapping for latex harvest per hectare) from 1952 to 2014 have been collected for plantations in the Hainan, Yunnan and Guangdong provinces of South China. A plantation survey was conducted to collect more detailed data on current tapping tree and planting densities in various plantations in the three provinces. Planting density and row spacing are found to have increased with rubber tree planting time and plant spacing to have declined from 1952 to 2014. Tapping-tree density of rubber plantations from 1955 to 1995 in South China ranges from 270 to 345 tree/ha, averaging 300 trees/ha. Strong typhoons and cold snaps are important drivers of fluctuations in tapping-tree density. The factors driving tapping-tree density are similar across the three provinces but the degree of change differs between provinces. Tapping panel dryness (due to tapping beyond the natural limit of the rubber tree productivity), severe wind damage and cold damage are the major factors resulting in loss of tapping trees in plantations in South China. These results suggest that a combination of environmental management for extreme weather and targeted breeding could improve tapping-tree density in rubber plantation and therefore dry rubber yield per unit area.

Evaluation of the population structure and genetic diversity of Plasmodium falciparum in southern China.

BackgroundYunnan and Hainan provinces are the two major endemic regions for Plasmodiumfalciparum malaria in China. However, few studies have investigated the characteristics of this parasite. Therefore, this study aimed to evaluate the genetic diversity and population structure of P. falciparum to predict the geographic origin of falciparum malaria.MethodsThirteen highly polymorphic microsatellite loci were studied to estimate the genetic diversity and population structure of 425 P. falciparum isolates obtained from blood samples collected from Yunnan and Hainan provinces of South China. The isolates were analysed for genetic diversity, linkage disequilibrium, and population structure. The parasite populations were clustered into two subgroups (i.e., Yunnan and Hainan) and a classification algorithm was used to identify molecular markers for classifying the P. falciparum populations.ResultsAll 13 microsatellite loci were highly polymorphic, with the number of alleles per locus varying from 5 to 20. The mean expected heterozygosity (He) in Yunnan and Hainan was 0.766 ± 0.036 and 0.677 ± 0.039, respectively, revealing a moderate high level of genetic diversity. Significant linkage disequilibrium was found for some regions of Yunnan (Lazan county and Xishuangbanna region) and Hainan (Dongfang city and Sanya city) province. According to the classification algorithm, a combination of three microsatellites could be used as a discriminatory marker to identify the origin of P. falciparum isolates.ConclusionsThe results on the genetic structure of P. falciparum populations from South China provide a basis for developing a genetic marker-based tool to trace the source of the parasite infections and consequently improve malaria control and elimination strategies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0786-0) contains supplementary material, which is available to authorized users.

Evaluation of health benefit using BenMAP-CE with an integrated scheme of model and monitor data during Guangzhou Asian Games

Guangzhou is the capital and largest city (land area: 7287km2) of Guangdong province in South China. The air quality in Guangzhou typically worsens in November due to unfavorable meteorological conditions for pollutant dispersion. During the Guangzhou Asian Games in November 2010, the Guangzhou government carried out a number of emission control measures that significantly improved the air quality. In this paper, we estimated the acute health outcome changes related to the air quality improvement during the 2010 Guangzhou Asian Games using a next-generation, fully-integrated assessment system for air quality and health benefits. This advanced system generates air quality data by fusing model and monitoring data instead of using monitoring data alone, which provides more reliable results. The air quality estimates retain the spatial distribution of model results while calibrating the value with observations. The results show that the mean PM2.5 concentration in November 2010 decreased by 3.5μg/m3 compared to that in 2009 due to the emission control measures. From the analysis, we estimate that the air quality improvement avoided 106 premature deaths, 1869 cases of hospital admission, and 20,026 cases of outpatient visits. The overall cost benefit of the improved air quality is estimated to be 165 million CNY, with the avoided premature death contributing 90% of this figure. The research demonstrates that BenMAP-CE is capable of assessing the health and cost benefits of air pollution control for sound policy making.