Provinces In Southern China Research Articles

Mapping the Spatial Distribution of Tea Plantations Using High-Spatiotemporal-Resolution Imagery in Northern Zhejiang, China

Tea plantations are widely distributed in the southern provinces of China and have expanded rapidly in recent years due to their high economic value. This expansion has caused ecological problems such as soil erosion, and it is therefore urgent to clarify the spatial distribution and area of tea plantations. In this study, we developed a simple method to accurately map tea plantations based on their unique phenological characteristics observed from VENμS high-spatiotemporal-resolution multispectral imagery. The normalized difference vegetation index (NDVI) and red—green ratio index (RGRI) of time series were calculated using 40 VENμS images taken in 2018 to evaluate the phenology of tea plantations. The unique phenological period of tea plantations in northern Zhejiang is from April to May, with obvious deep pruning, which is very different from the phenological period of other vegetation. During this period, the RGRI values of tea plantations were much higher than those of other vegetation such as broadleaf forest and bamboo forest. Therefore, it is possible to identify tea plantations from the vegetation in images acquired during their phenological period. This method was applied to tea plantation mapping in northern Zhejiang. The NDVI value of the winter image was used to extract a vegetation coverage map, and spatial intersection analysis combined with maps of tea plantation phenological information was performed to obtain a tea plantation distribution map. The resulting tea plantation map had a high accuracy, with a 94% producer accuracy and 95.9% user accuracy. The method was also applied to Sentinel-2 images at the regional scale, and the obtained tea plantation distribution map had an accuracy of 88.7%, indicating the good applicability of the method.

Chinese nonmedicinal herbal diet and risk of nasopharyngeal carcinoma: A population-based case-control study.

An association between a nonmedicinal herbal diet and nasopharyngeal carcinoma (NPC) has often been hypothesized but never thoroughly investigated. This study enrolled a total of 2469 patients with incident NPC and 2559 population controls from parts of Guangdong and Guangxi Provinces in southern China between 2010 and 2014. Questionnaire information was collected on the intake of traditional herbal tea and herbal soup as well as the specific herbal plants used in soups and other potentially confounding lifestyle factors. Multivariate logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the NPC risk in association with herbal tea and soup intake. Ever consumption of herbal tea was not associated with NPC risk (OR, 1.03; 95% CI, 0.91-1.17). An inverse association was observed for NPC among ever drinkers of herbal soup (OR, 0.78; 95% CI, 0.67-0.90) but without any monotonic trend with an increasing frequency or duration of herbal soup consumption. Inverse associations with NPC risk were detected with 9 herbal plants used in herbal soup, including Ziziphus jujuba, Fructus lycii, Codonopsis pilosula, Astragalus membranaceus, Semen coicis, Smilax glabra, Phaseolus calcaratus, Morinda officinalis, and Atractylodes macrocephala (OR range, 0.31-0.79). Consuming herbal soups including specific plants, but not herbal tea, was inversely associated with NPC. If replicated, these results might provide potential for NPC prevention in endemic areas.

Analysis of chemical components and biological activities of essential oils from black and white pepper (Piper nigrum L.) in five provinces of southern China

The chemical composition and antioxidant and antifungal activities of hydro-distilled essential oils (EOs) in black and white Piper nigrum L were evaluated in the present study. Hydro-distilled EOs obtained from black and white P. nigrum L from five areas of China was analyzed by gas chromatography-mass spectrometry (GC-MS). Nineteen compounds were identified, accounting for 98.20–99.35% of the oils. Chemical variation in the oils was estimated using systematic cluster analysis and principal component analysis. Moreover, antioxidant activity was determined by DPPH and ABTS radical cation scavenging assay, ferric reducing power assay, and ferric ion chelating activity assay, scavenging superoxide anion free radical activity assay and antifungal activity were assessed by micro-well dilution assay. Our results suggest that the region of origin greatly influences the pepper's chemical composition and bioactivities, which might support the development and utilization of this promising bio-resource in food industries.

Core set construction and association analysis of Pinus massoniana from Guangdong province in southern China using SLAF-seq

Germplasm resource collection and utilization are important in forestry species breeding. High-through sequencing technologies have been playing increasing roles in forestry breeding. In this study, specific-locus amplified fragment sequencing (SLAF-seq) was employed to analyze 149 masson pine (Pinus massoniana) accessions collected from Guangdong in China. A large number of 471,660 SNPs in the total collection were identified from 599,164 polymorphic SLAF tags. Population structure analysis showed that 149 masson pines could not be obviously divided into subpopulations. Two core sets, containing 29 masson pine accessions for increasing resin and wood yield respectively, were obtained from the total collection. Phenotypic analyses of five traits showed abundant variations, 25 suggestive and 9 significant SNPs were associated with the resin-yielding capacity (RYC’) and volume of wood (VW) using EMMAX and FaST-LMM; 22 suggestive and 11 significant SNPs were associated with RYC’ and VW using mrMLM and FASTmrMLM. Moreover, a large number of associated SNPs were detected in trait HT, DBH, RW and RYC using mrMLM, FASTmrMLM, FASTmrEMMA and ISIS EM-BLASSO. The core germplasm sets would be a valuable resource for masson pine improvement and breeding. In addition, the associated SNP markers would be meaningful for masson pine resource selection.

High risk of the fall armyworm invading Japan and the Korean Peninsula via overseas migration

AbstractThe fall armyworm, Spodoptera frugiperda (J.E. Smith), is an invasive pest species in the Old World. This species is originally native to the Americas. Since 2016, S. frugiperda has spread widely and rapidly throughout Africa, the Middle East, India, Southeast Asia and, most recently, to southern China. By May 2019, S. frugiperda had appeared in 13 provinces in southern China and will spread further into northern China. It is highly likely that S. frugiperda will enter Japan and Korea via overseas migrations as have many other migratory pests. To evaluate the risk of S. frugiperda invasion in Japan and the Korean Peninsula, we modelled the rate of expansion and future potential migratory range of the insect by a trajectory analytical approach using the flight behaviour of S. frugiperda and meteorological data of the past five years (2014–2018). If S. frugiperda can fly for up to 36 continuous hours over water, then our results predict migration from southern and eastern China into Japan and Korea. Most likely, Japan would be invaded from Fujian and Zhejiang in 1 June–15 July, and Kyushu, Shikoku and southwestern Honshu could face the highest risk of S. frugiperda invasion. Korea would most likely be reached by S. frugiperda from northern Zhejiang, Jiangsu, Anhui and Shandong in 1 June–15 July and later. Our results indicated a very high risk that S. frugiperda would annually invade Japan and the Korean Peninsula and cause a possible significant decrease in agricultural productivity.

Maternal hypertensive disorders in pregnancy and risk of hypoxic-ischemia encephalopathy

Background Hypoxic–ischemic encephalopathy (HIE) is one of the most serious birth complications for neonates. Few studies reported the relationship between maternal blood pressure disorders and risk of neonatal HIE. Objective This study was conducted to examine whether maternal hypertensive disorders in pregnancy increase the risk of HIE. Methods The analyses were performed using data from a large population-based cohort study aiming to prevent neural tube defects by supplementation with folic acid. The subjects comprised 183,981 women with singleton live births delivered at gestational ages of 32–42 weeks, who registered in two southern provinces in China. Blood pressure was measured by trained health care workers at each prenatal visit. Diagnosis information on HIE was recorded at the time of delivery. Results Totally 19,298 women (10.49%) were diagnosed with maternal hypertensive disorders in pregnancy and 255 infants (1.4 per 1000) with HIE, respectively. Compared with the normotensive group, a great increment in the risk of HIE was observed in women with hypertensive disorders (adjusted RR = 2.40, 95% confidence interval [CI]: 1.79–3.22) after adjusting for maternal confounding factors. A greater association was presented among preterm (32–36 weeks) infants with an adjusted RR of 5.45 (95% CI: 2.79, 10.65) compared to a RR of 2.09 (95% CI: 1.49, 2.92) among full-term (37–42 weeks) infants (p for heterogeneity < .05). Further stratification analyses showed that no matter with or without small for gestational age (SGA), maternal hypertensive disorders were associated with the increased risk for HIE. Sensitivity analyses excluding infants with low or high birth weight did not appreciably change the findings. Conclusions Our present study demonstrated a positive association of maternal hypertensive disorders in pregnancy with the risk of neonatal HIE.

46. HAPLOTYPES BASED ON EIGHT VARIANTS IN SOUTHERN CHINA POPULATIONS WITH COMMON Α-THALASSEMIA DELETIONS AND THEIR APPLICATION TO PREIMPLANTATION GENETIC TESTING

Introduction Around 5 to 20% of the population in the provinces of southern China are carriers of β-thalassemia mutations. In our hospital, more than half of couples treated with preimplantation genetic testing for monogenic diseases (PGT-M) are β-thalassemia carriers. The most common mutations are deletion in β-thalassemia genes (HBA1 and HBA2), including –SEA, -α 3.7, and -α 4.2. Preimplantation genetic haplotyping (PGH) is a powerful technology for PGT-M that can detect allele drop-out (ADO) accurately by detecting numerous linked or unlinked polymorphic markers in DNA segments surrounding the genes of interest. However, there is a lack of normative data references in the selection of linkage sites for disease. Therefore, a mutation-specific haplotype analysis will improve the efficiency of PGT-M for β-thalassemia. Materials & methods A total of 113 couples with β-thalassemia deletion mutations were collected from the Reproductive Medicine Center in the First Affiliated Hospital of Sun Yat-sen University and the Reproductive and Genetic Hospital of CITIC-Xiangya. A pre-examination validation for PGT-M was performed on these. The SNPs with large difference between reference frequency and alternate frequency in 452 haplotypes with or without three kinds of deletions were filtered out. Candidate sites close to the β-thalassemia genes were selected, upstream and downstream of genes within 1 Mb. Then, the haplotypes model was established with several specific genotypes of SNPs inherited with the mutations. Subsequently, the model was verified to predict the genotypes in another 34 couples after PGT-M. In addition, the ADO ratio of each site in 255 embryos was analyzed. Results Eight candidate SNPs (rs2562164, rs2857997, rs2857998, rs116995933, rs149153770, rs3918352, rs1203977, and rs1203979) were identified for the haplotypes model constructed for different genotypes. SEA-I (GCGTAACA), α3.7-I (AGACGACA) and α4.2-I (AGACGGAT) haplotypes were detected in 92.2%, 50.9%, and 70.8% genotypes with corresponding mutations, respectively. On average, 42.7% sites were able to be used as key SNPs in the verification of another 34 PGT-M cohort haplotypes and genotypes. The SEA-I model was detected in 91.1% of genotypes with –SEA mutation. The α3.7-I model was concordant with 37.5% of genotypes with the -α3.7 mutation. The α4.2-I models were inherited with 87.5% of genotype with the -α4.2 mutation. The average ADO ratio of the eight SNPs in the 255 embryos was 2.3%. Conclusions The haplotype analysis for common β-thalassemia deletion mutations including the eight-site model improves the efficiency of PGT-M in the population of southern China. The establishment of standardized diagnostic procedures and systems can be further extended to other populations for PGT-M in the future.

The evolutionary dynamics of DENV 4 genotype I over a 60-year period.

Dengue virus serotype 4 (DENV 4) has had a relatively low prevalence worldwide for decades; however, likely due to data paucity, no study has investigated the epidemiology and evolutionary dynamics of DENV 4 genotype I (DENV 4-I). This study aims to understand the diversity, epidemiology and dynamics of DENV 4-I. We collected 404 full length DENV4-1 envelope (E) gene sequences from 14 countries using two sources: Yunnan Province in China (15 strains during 2013–2016) and GenBank (489 strains up to 2018-01-11). Conducting phylogenetic and phylogeographical analyses, we estimated the virus spread, population dynamics, and selection pressures using different statistical analysis methods (substitution saturation, likelihood mapping, Bayesian coalescent inference, and maximum likelihood estimation). Our results show that during the last 60 years (1956–2016), DENV 4-I was present in mainland and maritime Southeast Asia, the Indian subcontinent, the southern provinces of China, parts of Brazil and Australia. The recent spread of DENV 4-I likely originated in the Philippines and later spread to Thailand. From Thailand, it spread to adjacent countries and eventually the Indian subcontinent. Apparently diverging around years 1957, 1963, 1976 and 1990, the different Clades (Clade I-V) were defined. The mean overall evolution rate of DENV 4-I was 9.74 (95% HPD: 8.68–10.82) × 10−4 nucleotide substitutions/site/year. The most recent common ancestor for DENV 4-I traces back to 1956. While the demographic history of DENV 4-I fluctuated, peaks appeared around 1982 and 2006. While purifying selection dominated the majority of E-gene evolution of DENV 4-I, positive selection characterized Clade III (Vietnam). DENV 4-I evolved in situ in Southeast Asia and the Indian subcontinent. Thailand and Indian acted as the main and secondary virus distribution hubs globally and regionally. Our phylogenetic analysis highlights the need for strengthened regional cooperation on surveillance and sharing of sample sequences to improve global dengue control and cross-border transmission prevention efforts.

The mineralization age of the Banxi Sb deposit in Xiangzhong metallogenic province in southern China

The Banxi Sb deposit is one of world-class Sb deposits located in the Xiangzhong Sb-Au metallogenic province in southern China. However, the mineralization age of this deposit is still not well constrained due to a lack of suitable minerals for reliable radiometric dating. Since the fluid-inclusion data suggest that the temperature of ore-forming fluids in the Banxi deposit is up to 330 °C, zircon (U-Th)/He thermochronometry with the closure temperature of 160–200 °C was chosen here to elucidate the timing of Sb mineralization of this deposit. Detrital zircons within three samples of altered host rocks in the Banxi deposit yielded (U-Th)/He dates of 132–113 Ma (weighted mean = 121 ± 12 Ma), 132–124 Ma (weighted mean = 129 ± 3 Ma) and 142–113 Ma (weighted mean = 125 ± 10 Ma), respectively, which are broadly consistent with the Rb-Sr and Sm-Nd isochron ages of hydrothermal sulfide minerals (~130 Ma). Combining with the reported ages of adjacent Sb deposits, we propose that Sb mineralization in the Banxi deposit may have primarily taken place during 130–120 Ma.

Initial detections and spread of invasive Spodoptera frugiperda in China and comparisons with other noctuid larvae in cornfields using molecular techniques.

The fall armyworm, Spodoptera frugiperda, is a species native to the Americas and has spread to many countries in Africa and Asia in recent years. Proactive actions for potential invasion of S. frugiperda to China coordinated by government agencies and agricultural extension systems resulted in timely detection in January 2019 in Yunnan province neighboring onto Myanmar. The extensive monitoring in southern provinces of China since February 2019 resulted in dynamic tracking of S. frugiperda spreading to 13 provincial regions in China within 4 months by May 10, 2019, which is crucial for timely management actions in the fields. The first detections of S. frugiperda (corn strain) in China were confirmed using cytochrome oxidase subunit 1 (CO1) and triosephosphate isomerase (Tpi) genes molecular marker method. In addition to S. frugiperda, larvae of three other noctuid species with similar morphological appearance (S. litura, S. exigua and Mythimna separata) can occur simultaneously and cause similar damage in cornfields in southern China. Thus, we can use both morphological and molecular marker methods to compare larval stages of four noctuid species. Further, we discuss the risk of potential spread of invasive S. frugiperda to other regions and impact on corn production in China.

An example of de‐Tai‐isation? Longue durée ethnic change in a mountainous area of southern China

Inspired by Grant Evans’ work Tai‐ization: Ethnic Change in Northern Indo‐China, this article explores aspects of historical ethnic change in the Yunkai and Yunwu Mountain Ranges, a small upland region intersected by the boundary of Guangdong and Guangxi provinces in southern China over the period 600–1700 C.E. The discussion begins with some of the early linguistic evidence for populations of Tai speakers in the region and what is known of their political and cultural systems, then moves on to consider how Chinese military conquests of the eighth century coupled with the migration of Sinitic and Mien peoples from the eleventh century onwards altered the ethnic composition and political landscape of the region. This is followed by an examination of different exonyms used in Chinese texts for populations of southern China from the fifteenth century onwards and how these might have related to linguistic groupings and identities on the ground, demonstrating that historical usage of Chinese exonyms now connected with Tai or Mien speakers is not always a reliable indicator of a corresponding presence of historical Tai or Mien‐speaking populations. Further research drawing on a number of disciplines is required on a localised level in order to determine when Tai and Mien languages were abandoned in the region and how the inhabitants of the area shifted from the status of named Others to ordinary Chinese subjects.

Ailuroglossum (Boraginaceae, Cynoglosseae), a New Genus Endemic to Southern China, and a New Species

A new genus, Ailuroglossum Sutorý (Boraginaceae), endemic to Sichuan and Yunnan provinces of southern China, is described. It includes two species: A. triste (Diels) Sutorý, formerly recognized as Cynoglossum triste Diels, and the newly described A. breviglochidiatum Sutorý. The genus is distinguished from Cynoglossum L. by a combination of characters, including a rhizome rather than a taproot, an almost flat gynobase, narrowly conical style, and discoid stigma, nutlets with perfect separation, without ventral attachment, and hourglass-shaped tricolporate pollen grains. The new species, A. breviglochidiatum, is distinguished by its more slender rhizomes with longer internodes, differently shaped leaves, and smaller nutlets with a denser indument of shorter glochids.

Detection and Genetic Characterization of Atypical Porcine Pestivirus in Piglets With Congenital Tremors in Southern China.

Atypical porcine pestivirus (APPV) is an RNA virus newly discovered from swine in Asia, Europe, and the Americas. This novel virus has been confirmed as the cause of congenital tremor (CT) in piglets, which causes extensive economic losses to the swine industry. To investigate the genetic diversity and evolutionary relationship of APPV in China, 83 piglet samples with severe CT clinical signs were obtained from 12 commercial swine farms in 3 provinces of Southern China. RT-PCR revealed that the positive rates of APPV were as high as 100% (12/12) for the swine farms and 90.4% (75/83) for the samples. Subsequently, 21 positive samples and 3 positive samples were selected for partial E2 gene and complete polyprotein gene sequencing, respectively. Phylogenetic analysis showed that 62.5% of the sequences belonged to a novel APPV clade provisionally named genotype 3, which showed 81.0–82.1% sequence identity to genotypes 1 and 2. Amino acid sequence alignment showed that E2 protein of genotype 3 has three specific mutation sites, namely I19V, Y82F, and N107G. The results of the present study demonstrate that a novel APPV subgenotype, which is widely distributed in severe CT clinical samples in Southern China, was genetically diverse. We advocate for the inclusion of genotype 3 during revision of the APPV typing method.

Emergence of Getah Virus Infection in Horse With Fever in China, 2018.

Getah virus (GETV) is a mosquito-borne virus that was first determined in Malaysia in 1955, and can infect humans and multiple other mammals. GETV infection in horses has been reported in Japan and India, and causes great economic losses. In China, GETV has been identified in mosquitoes, pigs, foxes, and cattle with a wide geographical distribution, but has not been detected in horses. In August 2018, a sudden onset of fever was observed in racehorse in an equestrian training center in Guangdong Province in southern China. Blood samples were collected from the sick horse, and PCR/RT-PCR analysis was performed to screen for equine viral pathogens associated with fever. The results indicated that the samples were GETV RNA positive. After RT-PCR, sequencing, and assembly, the genome of the first Chinese horse-derived GETV strain, GZ201808, was obtained. Compared with the genome sequences of other GETV strains, twelve unique nucleotide substitutions were observed in GZ201808. The genome of GZ201808 had the highest genetic identity (99.6%) with AH9192, which was detected in pigs in China in 2017. Phylogenetic analysis indicated that GZ201808 clustered in Group III, and was located in an independent branch distant from other horse-derived GETV strains, indicating a unique evolutionary pattern of GZ201808. This study first determined and described the disease course of horse infected with GETV in China, sequenced and characterized the genome of the field horse-derived GETV strain, and therefore presented an unequivocal report of GETV infection in horses in China.

The Relationship between Physical Activity and Physical Performance and Cognitive Abilities in the Chinese Elderly

PURPOSE: Decreased physical and cognitive ability have become seriously problematic in aging. Studies seldom describe the relationship between physical activity (PA), physical performance and cognitive abilities, most of which by measuring only one or two specific abilities using questionnaires. The study was thus designed to examine the relationship between PA and physical performance and multiple cognitive abilities in the Chinese elderly. METHODS: The design was a cross-sectional study. 148 people aged 65.15±7.79 were included from Guangxi Province in southern China. PA was measured by the Physical Activity Scale for the Elderly (PASE, Cronbach’s ɑ=0.752; Test-retest reliability=0.980). Physical performance included coordination and lower limb strength, functional walking ability and the balance ability. Cognitive abilities were measured by computer-based tests, including simple reaction time and executive function (stroop task and shifting task). The association between PA and the outcomes were examined using correlation matrix and linear regression. RESULTS: 1) The average time spent on physical activity was 1.8h/d; 2) High levels of PA significantly associated with better gait speed (B=-0.67, p<0.05), 30-s chair-stand test (B=0.72, p<0.05) and reaction abilities (B=0.89, p<0.05); 3) The gait speed significantly correlated with the accuracy of stroop task (r = 0.23, p = .018) and shifting task (r = 0.21, p = 0.023), grip strength significantly correlated with the accuracy and the reaction time of the stroop task(r = 0.19, p = 0.04 & r = 0.19, p = 0.04). However, other physical performance outcomes had no significant correlation with the cognitive abilities. CONCLUSIONS: More physically active residents scored higher on physical performance outcomes. Positive associations were found between physical performance, executive function and reaction ability.

Capacity assessment of the health laboratory system in two resource-limited provinces in China

BackgroundStrong laboratory capacity is essential for detecting and responding to emerging and re-emerging global health threats. We conducted a quantitative laboratory assessment during 2014–2015 in two resource-limited provinces in southern China, Guangxi and Guizhou in order to guide strategies for strengthening core capacities as required by the International Health Regulations (IHR 2005).MethodsWe selected 28 public health and clinical laboratories from the provincial, prefecture and county levels through a quasi-random sampling approach. The 11-module World Health Organization (WHO) laboratory assessment tool was adapted to the local context in China. At each laboratory, modules were scored 0–100% through a combination of paper surveys, in-person interviews, and visual inspections. We defined module scores as strong (> = 85%), good (70–84%), weak (50–69%), and very weak (< 50%). We estimated overall capacity and compared module scores across the provincial, prefecture, and county levels.ResultsOverall, laboratories in both provinces received strong or good scores for 10 of the 11 modules. These findings were primarily driven by strong and good scores from the two provincial level laboratories; prefecture and county laboratories were strong or good for only 8 and 6 modules, respectively. County laboratories received weak scores in 4 modules. The module, ‘Public Health Functions’ (e.g., surveillance and reporting practices) lagged far behind all other modules (mean score = 46%) across all three administrative levels. Findings across the two provinces were similar.ConclusionsLaboratories in Guangxi and Guizhou are generally performing well in laboratory capacity as required by IHR. However, we recommend targeted interventions particularly for county-level laboratories, where we identified a number of gaps. Given the importance of surveillance and reporting, addressing gaps in public health functions is likely to have the greatest positive impact for IHR requirements. The quantitative WHO laboratory assessment tool was useful in identifying both comparative strengths and weaknesses. However, prior to future assessments, the tool may need to be aligned with the new WHO IHR monitoring and evaluation framework.

Complicated HCV subtype expansion among drug users in Guangdong province, China

Guangdong Province is one of the most developed and populous provinces in southern China. The subtype situation of hepatitis C virus (HCV) in Guangdong remains unknown. The aim of this study was to investigate and estimate the HCV subtypes in drug users (DU) using a city-based sampling strategy to better understand the characteristics of HCV transmission in Guangdong. Archived plasma samples (n = 1074) from DU who were anti-HCV positive in 2014 were selected randomly from 20 cities in Guangdong Province. Subtypes were determined based on core and/or E1 sequences using phylogenetic analysis. The distributions of HCV subtypes in DU and different regions were analyzed. A total of 8 genotypes were identified. The three main HCV subtypes in DU in Guangdong were 6a (63.0%), 3a (15.2%), and 3b (11.8%). Significant differences were discovered among different registered residency and regions but not among genders, marital status, education level, or drug use patterns. HCV subtype 3b was significantly higher in Guangdong residents than in non-Guangdong residents. In contrast, HCV subtype 6a was significantly lower in Guangdong residents than in non-Guangdong residents. Subtype 1b in eastern Guangdong (eastern) was significantly lower, while 6a was significantly higher when compared with other regions. Subtype 3a in the Pearl River Delta (PRD) region was significantly higher, while 3b was significantly lower when compared with other regions. In western Guangdong, HCV subtype 3a was significantly lower when compared with other regions. Additionally, in northern Guangdong subtypes 1b and 3b were significantly higher, while 6a was significantly lower when compared with other regions. Our study revealed the diversity and distribution of HCV subtypes in DU in nearly all the cities in Guangdong. The results provide essential information that will allow the establishment of specific intervention strategies that may help prevent HCV transmission.

Cold water immersion test (10°C, 10min) for diagnosing vibration-induced white finger among a group of polishers in a subtropical environment.

This study aimed to investigate whether the finger skin temperature (FST) after cold provocation (10°C, 10min) is as a useful indicator for assisting in the diagnosis of vibration-induced white finger (VWF) in a group of polishers in a subtropical environment. Ninety male vibration-exposed metal polishers (30 patients and 60 controls) from the Guangdong Province in Southern China were recruited. The FSTs at 30, 20, 10, and 0min before cold water immersion (FSTpre-30, FSTpre-20, FSTpre-10, and FSTbaseline) and 0, 5, 10, 15, 20, 25, and 30min after immersion (FST0, FST5, FST10, FST15, FST20, FST25, and FST30) were measured on the index, middle, and ring fingers of both hands. During the first 20-min adaptation period, there was a significant increase in FST in three fingers on both hands in the two groups. In contrast, there were no significant differences between FSTpre-10 and FSTbaseline. Furthermore, FSTpre-30, FSTpre-20, FSTpre-10, and FSTbaseline of the three fingers in both hands did not differ significantly. During recovery, the indicators FST5-0, FST10-0, R5, and R10 for the index finger of the left hand in patients were lower than for the controls. Among the various indicators, the absolute recovery rate, FST5-0, at 5min after immersion was identified as the best diagnosis indicator with a sensitivity of 76.7% and specificity of 70.0% when applied to the index finger of the left hand. The cold water immersion test as applied in a subtropical environment can have a fair discriminating ability for diagnosing VWF.

Adoption of direct seeded rice, land use and enterprise income: Evidence from Chinese rice producers

China is the world largest producer and consumer of rice. With stagnant yields, resource depletion, labor shortages direct-seed rice (DSR) is gaining the interest of rice producers in southern China. This study investigates the impact of the adoption of DSR on rice yield and net rice income of Chinese farmers. We use plot-level data from four provinces in southern China. Results indicate that rice yield increase by 3.1% for DSR adopters and by 0.7% if puddled transplanted rice (PTR) producers adopted DSR method. Finally, we find that net rice income increased by 66% if PTR method plots switched to DSR method. Adoption of DSR should be encouraged by policymakers.

Endemic Melioidosis in Southern China: Past and Present.

Melioidosis is a severe tropical infectious disease caused by the soil-dwelling bacterium Burkholderia pseudomallei, predominantly endemic to Southeast Asia and northern Australia. Between the 1970s and the 1990s, the presence of B. pseudomallei causing melioidosis in humans and other animals was demonstrated in four coastal provinces in southern China: Hainan, Guangdong, Guangxi, and Fujian, although indigenous cases were rare and the disease failed to raise concern amongst local and national health authorities. In recent years, there has been a rise in the number of melioidosis cases witnessed in the region, particularly in Hainan. Meanwhile, although China has established and maintained an effective communicable disease surveillance system, it has not yet been utilized for melioidosis. Thus, the overall incidence, social burden and epidemiological features of the disease in China remain unclear. In this context, we present a comprehensive overview of both historical and current information on melioidosis in Southern China, highlighting the re-emergence of the disease in Hainan. Surveillance and management strategies for melioidosis should be promoted in mainland China, and more research should be conducted to provide further insights into the present situation.