Eastern Guangdong Research Articles

A case-control study of environmental exposures for nonsyndromic cleft of the lip and/or palate in eastern Guangdong, China

ObjectiveTo study the relationship between environmental factors and nonsyndromic cleft of the lip and/or palate (NSCLP) in eastern Guangdong for the prevention of NSCLP. MethodsA 1:1 retrospective case-control study was carried out. Data from 479 children with NSCLP who accepted comprehensive care in our center were recruited as cases from April 2010 to April 2013. An equal number of controls were recruited from pediatrics during the same period. Then we conducted face-to-face interviews with both parents using a structural questionnaire to identify the relationship between NSCLP and environmental risk factors. ResultsUnivariate Chi-square analysis identified 23 factors (P<0.05) as being significantly related to NSCLP. Stepwise multiple logistic regression analyses demonstrated that there were 16 factors significantly associated with this disease. Being male (OR=0.609), parental childbearing age of 25–29 years (ORfather=0.633; ORmother=0.469), higher parental education level (high school or greater) and folic acid supplementation (OR=0.360) were protective factors against NSCLP. However, positive family history of NSCLP (OR=54.132), positive maternal abortion history (OR=3.698), high or low parental age at time of childbirth, poor maternal education level (primary school) (OR=2.258), maternal common cold during pregnancy (OR=1.464), and drug use during pregnancy (OR=3.364) were significant risk factors for NSCLP. ConclusionThe findings are beneficial for researchers to understand the etiology of NSCLP and to lay a solid foundation for the prevention of NSCLP in eastern Guangdong through educational programs to teach parents about the benefits of folic acid supplementation, adequate parental age at childbirth (25–29 years), higher parental education level (high school or higher), and the dangers of common cold and drug use during the first trimester of pregnancy, positive family history and maternal abortion history.

Improving the seasonal forecast for summertime South China rainfall using statistical downscaling

AbstractThe performance of various seasonal forecast systems in predicting the station‐scale summer rainfall in South China (SC) was assessed and was compared with that based on a statistical downscaling scheme. Hindcast experiments from 11 dynamical models covering the period of 1983–2003 were taken from the Asia‐Pacific Economic Cooperation Climate Center multimodel ensemble. Based on observations, singular value decomposition analysis (SVDA) showed that SC precipitation is strongly related to the broad‐scale sea level pressure (SLP) variation over Southeast Asia, western north Pacific, and part of the Indian Ocean. Analogous covariability was also found between model hindcasts and the observed station precipitation. Based on these results from SVDA, a statistical downscaling scheme for predicting SC station rainfall with model SLP as predictor was constructed. In general, the statistical scheme is superior to the original model prediction in two geographical regions, namely, western SC (near Guangxi) and eastern coastal SC (eastern Guangdong to part of Fujian). Further analysis indicated that dynamical models are able to reproduce the large‐scale circulation patterns associated with the recurrent modes of SC rainfall, but not the local circulation features. This probably leads to erroneous rainfall predictions in some locations. On the other hand, the statistical scheme was able to map the broad‐scale SLP patterns onto the station‐scale rainfall anomalies, thereby correcting some of the model biases. Overall, our results demonstrate how SC summer rainfall predictions can be improved by tapping the source of predictability related to large‐scale circulation signals from dynamical models.

ANALYSIS OF GERMPLASM RESOURCES AND GENETIC DIVERSITY OF DIOSPYROS L. FROM EASTERN GUANGDONG

We studied the germplasm resources and genetic diversity of Diospyros L. These twenty populations derived from eastern Guangdong were analyzed by inter-simple sequence repeat (ISSR). Here, five primers could produce highly reproducible ISSR bands. Among 71 amplified bands, 63 exhibited polymorphism well, the percentage of polymorphic bands reached 88.73%. The results indicated that the collected Diospyros L. had a high genetic diversity in Eastern Guangdong. The UPGMA cluster analysis showed that 20 populations could be divided into four groups, which indicated that germplasms from the same region were not clustered completely following the collection source. It may be related to folk culture introduction or less than normal for ISSR primers.

Low Prevalence of HPV in Male Sexual Partners of HR-HPV Infected Females and Low Concordance of Viral Types in Couples in Eastern Guangdong

To investigate the prevalence of genital high-risk human papillomavirus (HR-HPV) in male sexual partners of HR-HPV infected women and the concordance of viral types in couples in China, and comprehend the role of men play in HPV transmission to women. 94 asymptomatic women and their husbands from rural Chaozhou participated in epidemiologic screening for HPV infection. Cervical cells from females were collected for high risk HPV screening by real time-PCR, and they were positive for at least 1 of 13 HR-HPV subtypes, then these samples were genotyped. Approximately one mouth later, penile epithelial cells from 94 asymptomatic husbands were collected for HPV genotyping. At the same time, a cross-sectional study was conducted in 366 male patients from sexually transmitted disease (STD) outpatient clinic in China for the prevalence of genital HR-HPV infection in men having frequent sex behavior. Penial epithelial cells were collected for HPV 6/11 and HPV 16/18 detection by fluorescent real-time quantified PCR. Among 94 couples, the prevalence of genital HR-HPV infection in men whose wife was positive for cervical HR-HPV was 5.32% (5/94). Only 2.63% (2/76) had the same high risk viral type presented by their wife. HPV 16 proved to be the most prevalent viral type in men and in couples. Of 366 male patients from STD outpatient clinic, the prevalence of HPV 16/18 infection in men with or without HPV 6/11 was 6.85% and 8.16%, respectively. The incidence of HPV 16/18 was higher in men aged more than 35 years than the young men (18-35 years). The prevalence of genital HR-HPV infection in male sexual partners of HPV-positive women in China was lower than that expected, and the concordance of high risk viral type between couples was extremely low. These data suggested that infected men consitute an important viral reservoir, contributing to transmission of HR-HPV to women and maintenance of infection, but HR-HPV infection may be less likely to persist in men than in women.

Environmental impact factors and mercury speciation in the sediment along Fujian and eastern Guangdong coasts

Concentrations of total mercury (THg) and methyl mercury (MeHg) were determined for 32 surface sediments collected along the coastal line of Fujian Province and eastern Guangdong Province. The spatial distributions of THg and MeHg and their environmental impact factors were investigated. The average concentrations of THg and MeHg in the sediments were 31.5 ng/g and 0.096 ng/g, respectively. Both sediment THg and MeHg concentrations showed relatively high value in the Minjiang Estuary and the coastal areas of Quanzhou and Putian. The concentrations overall decreased as the distance to the shoreline increased. The correlations among environmental impact factors and THg, MeHg were analyzed. The sediment THg concentration was highly correlated to the concentrations of organic matter, copper, total nitrogen (TN) and total phosphorus (TP), and significantly correlated to pH value of the bottom seawater and concentration of sediment sulfide. The sediment MeHg concentration was highly correlated to the concentrations of organic matter and copper, and significant correlated to the concentrations of sulfide, TN, TP and pH value of the bottom seawater.

OCPs and PCBs in Marine Edible Fish and Human Health Risk Assessment in the Eastern Guangdong, China

Marine edible fish samples were collected from two important nearshore fishing sites in the eastern Guangdong Province, China: Shantou Harbor and Haimen Bay. In the mixed edible muscle tissues of marine fish samples, the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, and hexachlorobenzene ranged from 1.12 to 53.87, ND (not detected) to 84.01, 0.22 to 7.09, ND to 4.74, and ND to 1.49 ng/g wet weight (ww) in Haimen Bay, respectively, and from ND to 70.35, ND to 164.83, ND to 8.68, ND to 25.61, and ND to 1.76 ng/g ww in Shantou Harbor, respectively. The concentrations of PCBs, DDTs, and HCHs in all samples did not exceed maximum residue limits (China and United States Food and Drug Administration). However, a few fish samples exceed the maximum levels established by the European Union. Daily fish consumption from this region can be of serious concern, and lifetime cancer risk remains a possibility in the studied area.

Chemical weathering and CO&lt;sub&gt;2&lt;/sub&gt; consumption in the Wuhua River basin,eastern Guangdong Province

Measurements of physicochemical components in the mainstream and tributaries of the Wuhua River system and application of methods of mass-balance and Pearson correlation analysis were conducted to investigate the atmospheric CO2consumption caused by rocks chemical weathering processes in the subtropical humid mountainous and hill region.Results show that the average concentration(77.11mg/L) of the total dissolved solids within the Wuhua River was close to that(65 mg/L) in the world rivers,dominated by ions of Ca2+,Na+ and HCO-3 and followed by dissolved Si;ions of Ca2+,Na+ and HCO-3 were characterized by the effect of runoff dilution.Chemical runoff in the Wuhua River was dominated by silicate mineral weathering,followed by carbonate mineral.Atmospheric and soil CO2 were major erosive mediums during rocks chemical weathering in the basin,with acids precipitation as the secondary erosive mediums.Comparatively,the atmospheric CO2 consumption flux(2.14×105 mol/(km2·a)) by the rock chemical weathering processes in the Wuhua River basin is lower than that of the world.This is in agreement with the distribution of extensively rocks composed of silicate minerals,sparsely rock containing carbonate minerals.

Geochronology and geochemistry of Cenozoic basalts from eastern Guangdong, SE China: constraints on the lithosphere evolution beneath the northern margin of the South China Sea

The 40Ar–39Ar dating reveals three episodes of basaltic volcanism in eastern Guangdong of SE China since the late Eocene (i.e., 35.5, ~20 and 6.6 Ma). The Miocene alkali olivine basalts (~20 and 6.6 Ma) have OIB-like trace element characteristics, which is coupled with low (87Sr/86Sr)i, high eNd(t), and high eHf(t). In contrast, the late Eocene basalts (35.5 Ma) have overall characteristics of “Island Arc” basalts with strong negative Ta–Nb–Ti anomalies in the primitive mantle-normalized multi-element diagram with high (87Sr/86Sr)i, negative eNd(t), and relatively low eHf(t). All basalts have unexpectedly high 207Pb/204Pb and 208Pb/204Pb, delineating a DUPAL signature in the sources. The late Eocene Arc-like basalts may reflect contributions of relict ancient metasomatized mantle lithosphere that melted as the result of extension-induced asthenospheric upwelling and heating, whereas the Miocene OIB-like basalts may represent partial melting of the asthenospheric mantle beneath the thickened lithosphere. We propose that the Cenozoic basaltic volcanism in eastern Guangdong records an overall lithospheric thickening process beneath SE China, that is, a continental rift system from its maximum extension in the late Eocene to its waning in the Miocene. This interpretation is consistent with the evolution of the South China Sea, whose origin is most consistent with the development of a passive continental margin. The seafloor spreading of the South China Sea during ~ 32–16 Ma may not result from the effect of the “Hainan” mantle plume, but rather played a positive role in allowing the mantle plume to express on the surface.

Onset of the Kwangsian Orogeny as evidenced by biofacies and lithofacies

The onset timing of the Kwangsian Orogeny might differ among localities across South China. Refined stratigraphic works at different localities are necessary to reveal the details of this likely distinction. Recently, we recollected some graptolite specimens from the Ordovician Shixing and Longtouzhai formations (corresponding to the Longxi Formation of southern Jiangxi Province) at many localities in Guangdong Province. The palaeontological and biostratigraphical studies of these graptolite faunas indicate that the facies change from graptolitic shale to nearshore shallow-water, coarse clastics in Guangdong is slightly earlier than that in southern Jiangxi. This timing difference may imply a northward progression of the Kwangsian Orogeny. Based on the biostratigraphy and palaeontology of the Ordovician in the Zhujiang Basin (western part) and Chiangnan Slope Belt (including western Fujian, eastern Guangdong, northern Guangxi, northern Hunan, northeastern Jiangxi, southern Anhui, and western Zhejiang), the Sandbian to late Katian distribution and replacement of biofacies and lithofacies in the two regions are proposed and discussed, which display distinct features at different stages of the Kwangsian Orogeny.

Prior Knowledge, Older Age, and Higher Allowance Are Risk Factors for Self-Medication with Antibiotics among University Students in Southern China

BackgroundSelf-medication with antibiotics (SMA) has been reported among university students in many countries, but little research has been done on this issue in China. The objective of this study was to evaluate knowledge and behaviors of university students and risk factors concerning SMA.Methodology/Principal FindingsUsing a novel questionnaire-based data collection instrument, an anonymous online survey was conducted with the students of Shantou University (STU), a university comprising 8 schools/colleges in eastern Guangdong, China. Of 1,300 respondents (13.8% of total eligible participants), 47.8% had self-treated with antibiotics. Logistic regression analysis identified prior knowledge of antibiotics (PKA), older age, and higher monthly allowance as independent risk factors for SMA. PKA significantly influenced students' knowledge about antibiotics, their uses, and common adverse reactions (all p<0.05). Among self-medicated students, 61.7% used antibiotics at least twice in the previous year. Community pharmacies were the major source of self-prescribed antibiotics. Reported common indications for SMA were sore throat (59.7%), fever (38.2%), cough (37.4%), runny nose (29.3%), and nasal congestion (28.7%). While 74.1% of self-medication episodes were based on students' own experiences, only 31.1% of students claimed to understand the package insert. Alteration of antibiotics and dosage during the course of self-treatment was made by 63.8% and 55.6% of students, respectively. At least two kinds of antibiotics were simultaneously taken by 82.6% of students. The majority of self-medicated students failed to complete the course of antibiotics. Adverse reactions were reported by 16.3% of students. Amoxicillin was the most common antibiotic used for self-medication.ConclusionsHigh prevalence of SMA was noted among STU students. Presence of risk factors and risk-associated behaviors/attitudes in the study population calls for focused educational intervention and stricter governmental legislation and regulation of antibiotic use and sale in pharmacies.

Foonchewia guangdongensis gen. et sp. nov. (Rubioideae: Rubiaceae) and its systematic position inferred from chloroplast sequences and morphology

Abstract The new species, Foonchewia guangdongensis R. J. Wang &amp; H. Z. Wen and the new monotypic genus Foonchewia R. J. Wang (Rubioideae, Rubiaceae), are described from eastern Guangdong, China. It is characterized by its subshrub habit, pentamerous and heterostylous flowers, 2‐1ocular ovary with many ovules, and apically dehiscent capsules with numerous angulated seeds. Phylogenetic analysis of four chloroplast DNA regions (rbcL, rps16, ndhF, and atpB‐rbcL) revealed that the new genus is nested in the Spermacoceae alliance and is sister to Dunnia. Morphological comparison between these two genera indicated that they had few synapomorphies; it was therefore inappropriate to classify the new genus in the existing tribe Dunnieae, and a new tribe, Foonchewieae R. J. Wang, is accordingly proposed.

Evaluation of the genetic variability of human papillomavirus type 52

Human papillomavirus (HPV) type 52 is one of the high-risk HPV types. Its variants can be classified as of Asian and European lineages, while little data of HPV 52 variants are available from China. In this study, the complete E6 and L1 genes were amplified and sequenced in 79 samples from eastern Guangdong, China. In total, 21 variants were identified, 18 of which could be divided into Asian lineage and the other three were phylogenetically related to European lineage. No significant difference was found between the pathogenicity of these two lineage variants. Two HPV-52 lineages variants could be classified by high resolution melting (HRM) analysis. Thus, we believe that the application of HRM analysis would be useful for facilitating pathogenic comparisons between different HPV variants. In addition, we found that 6 females were infected with two types of HPV-52 variants. To our knowledge, this is the first time that this rare phenomenon is reported worldwide.

Assessment of Economic Damage Risks from Typhoon Disasters in Guangdong, China

Guangdong is a developed province in China, but suffers from frequent typhoon disasters which cause great economic loss. Quantitative regional risk assessment of typhoon disasters is important for disaster prevention and mitigation. According to direct economic loss and typhoon intensity information, we established a typhoon disaster loss rate curve using data from 1954 to 2008. Based on GIS spatial module, the economic vulnerabilities of different intensity typhoons were calculated for 98 counties in Guangdong Province. Different intensity typhoon landing frequencies in Guangdong were also calculated, and used to indicate typhoon disaster probability. A risk assessment model was established to assess economic loss risk under different intensity typhoons in Guangdong. The results show that economic loss risk caused by typhoon is more than 10 thousand million CNY; according to typhoon intensity grade, economic risk is up to 10.467, 14.429, 7.753 and 13.591 thousand million CNY for slight, light, medium and severe typhoons, respectively. The Pearl River Delta is the highest risk region, especially Guangzhou, Dongguan, Shenzhen, Zhongshan and Zhuhai. Risk value decreases from Pearl River coastal outfall to the inland in a radial pattern. Inland areas far from coastal counties have lower risk, and the risk value is less than 50 million CNY. When typhoon intensity increases from slight to medium, the risk in western is higher than in eastern parts, but when typhoons become to severe, the risk value in eastern Guangdong part is higher than in the west.

Soil C:N:P Stoichiometry across Forest Communities in Eastern Guangdong, China

Stoichiometric characteristics of soil organic carbon (SOC), total nitrogen (N) and total phosphorus (P) across forest communities were investigated based on community classification in Changtan Nature Reserve, Guangdong province, China. Results are as follows: (1) the monsoon broadleaved forest had high concentrations of SOC, N and P as compared with other community types. The highest concentration of SOC (39.2±2.3 g•kg-1) was found in the Schima superba community, while the highest concentration of N (2.21±0.24 g•kg-1) occurred in the Castanopsis fissa community, which also had the highest P concentration. Pinus massoniana community had the lowest concentrations of SOC, N, and P, especially lacking in P element. (2) Communities which had longer succession time exhibited a high C:P ratio. The Schima superba and Castanopsis fissa communities had the highest C:P ratios (301.0 and 304.2, respectively); in contrast, soil C:P ratio in the Cunninghamia lanceolata community was only 150.0. (3) The highest and lowest ratios of soil C:N were found in monsoon evergreen broadleaved forest (36.6) and Schima superba community (17.0), respectively, which was significantly different (P &lt; 0.05). No significant difference was found in the N:P ratios among the five communities.

Epidemiologic Characterization of Human Papillomavirus Infection in Rural Chaozhou, Eastern Guangdong Province of China

BackgroundHuman papilloma virus (HPV) infection was the main cause of cervical cancer. There were only a few reports and detailed data about epidemiological research of HPV infection in rural population of China.Materials and MethodsThe cervical cells of rural Chaozhou women were collected, and multiplex real time PCR was firstly performed to detect high-risk HPV (HR-HPV) infection, which could detect 13 types of HR-HPV (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68). Then, HPV-positive samples were typed by HPV GenoArray test.ResultsHR-HPV DNA was detected by multiplex real time-PCR in 3830 of 48559 cases (7.89%). There was a peak incidence in age of 55–60 years group, and a lower incidence in who lived in plain group compared with suburban, mountain and seashore group. 3380 cases of HPV positive sample were genotyped, 11.01% (372/3380) cases could not be classified, among the typed 3008 cases, 101 cases were identified without HR-HPV type infection, 2907 cases were infected with one HR-HPV type at least, the 6 most common HR-HPV types in descending order of infection, were type 52 (33.4%, 16 (20.95%), 58 (15.93%), 33 (9.94%), 68 (9.22%) and 18 (8.36%). The combined prevalence of HPV types 16 and 18 accounted for 28.52% of total infection. However, type 52 plus 58 presented 48.23% of total infection. 2209/2907 cases were infected with a single HPV type and 698/2907 cases were infected with multiple types, and multiple infection constituent ratio increased with age, with a peak incidence in age 55–60 years group.ConclusionsOur findings showed low prevalence of HPV vaccine types (16 and 18) and relatively high prevalence of HPV-52 and -58, support the hypothesis that the second-generation HPV vaccines including HPV-52 and -58 may offer higher protection for women in rural Guangdong Province.

典型低纬度海区(南海、孟加拉湾)初级生产力比较

PDF HTML阅读 XML下载 导出引用 引用提醒 典型低纬度海区(南海、孟加拉湾)初级生产力比较 DOI: 10.5846/stxb201108221228 作者: 作者单位: 广东省渔业生态环境重点实验室,中国水产科学研究院南海水产研究所;中国科学院南海海洋研究所,中国科学院南海海洋研究所,中国科学院南海海洋研究所,中国科学院南海海洋研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(41130855, 40906057);中央级公益性科研院所基本科研业务费(中国水产科学院南海水产研究所)资助项目(2011TS06);农业部南海渔业资源开发利用重点实验室开放基金(LSF2011-05);中国科学院海洋生物资源可持续利用重点实验室开放基金(LMB111010) A comparison study on primary production in typical low-latitude seas (South China Sea and Bay of Bengal) Author: Affiliation: South China Sea Fisheries Institute, China Academy of Fishery Sciences,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:南海和孟加拉湾有着相似的纬度范围,均处于低纬度季风区,但环境的开放性和水体交换特征有所不同。将南海和孟加拉湾的初级生产力进行对比,有助于加深人们对低纬度海区生物生产过程的认识。南海有着复杂的物理过程,存在涡旋、上升流、黑潮、台风和冲淡水等多种现象,显著地影响着初级生产力大小和时空分布。南海初级生产力有以下几个特点:(1)受冲淡水和沿岸上升流的影响,沿岸海域常常高于开阔海区;(2)初级生产力的高值通常不出现在表层,大都出现在次表层;(3)在开阔海区受水体交换(黑潮等)和中尺度现象影响(涡旋)显著。此外,南海初级生产力的季节变化也比较明显,但季度变化规律有较强的区域性。孟加拉湾物理环境与南海差别明显,初级生产力主要受淡水输入、涡旋和光照的影响,受台风和上升流影响不如南海明显。在沿岸区,高温低盐水覆盖了沿岸上层水体,使得混合层较稳定,抑制了深层富含营养盐水体的涌升补充,导致初级生产力下降;光强(悬浮物多、多云天气多)也限制了初级生产力。孟加拉湾开阔海区常常有涡旋形成,也对初级生产力有一定影响。沿岸区初级生产力南海高于孟加拉湾,而在开阔海区两者差别不大,因此整体上南海初级生产力水平高于孟加拉湾。 Abstract:The Bay of Bengal (BOB), the largest bay in the world, forms the northeastern part of the Indian Ocean. Both the BOB and the South China Sea (SCS) were influenced by monsoon seasonally with similar latitude range. Primary productions (PP) of the two seas and their influencing factors were reviewed in this paper. The spatial distributions of PP and their environmental regulation mechanisms showed obvious differences between the two seas. Complicated physical phenomena could be found in the SCS, such as mesoscale eddies, coastal upwelling, Kuroshio, typhoon and river discharges. River discharges (especially those from the Pearl River and the Mekong river) and coastal upwelling (e.g. the Eastern Guangdong upwelling) bring abundant nutrients to the coastal waters in the southwest monsoon period, and result in the stimulation of phytoplankton growth. Mesoscale eddies (cold eddy or warm eddy) have different physical structures from adjacent waters, and can influence the nutrients availability. Kuroshio intrusion (characterized as warm and oligotrophic waters) and typhoon can also regulate PP in the SCS. Various physical processes could potentially control nutrient supply in the euphotic layer, and consequently influence the spatial and temporal variation of PP in the SCS. In the BOB, copious rainfall and river discharge often decreased salinity in the upper layers during summer, and sea surface temperature was warmer than in the SCS, leading to strong stratification in the upper layer. Weak wind over the Bay was unable to erode the strongly stratified surface waters; thereby the wind-driven vertical mixing was restricted within a shallow depth. This inhibits any possible introduction of nutrients from deeper water below the mixed layer into the upper layer. Meanwhile, suspended solids from the discharges and cloudy weather decreased light availability and therefore limited phytoplankton growth. In the near-shore area, river discharge and coastal upwelling can enhance PP in the SCS, while stratification in the BOB can inhibit algal growth in the euphotic zone, so PP in the coastal waters of SCS was higher than that in the BOB. In the open sea area, PP in the SCS is supposed to be close to that in the BOB. As a whole, PP in the SCS is evaluated to be higher than in the BOB. 参考文献 相似文献 引证文献

Multi-stage crust–mantle interaction in SE China: Temporal, thermal and compositional constraints from the Mesozoic felsic volcanic rocks in eastern Guangdong–Fujian provinces

The Mesozoic geology of southeastern (SE) China was characterized by emplacement of voluminous felsic magmas. We present zircon U–Pb–Hf isotopic compositions and whole-rock major and trace elemental compositions of a series of felsic volcanic rocks from the eastern Guangdong and Fujian provinces. The volcanic rocks have been divided into three formations (the Douling, Nanyuan and Shimaoshan Fms.). Zircon U–Pb dating defines three eruption cycles: 168–145Ma for the Douling Fm., 143–130Ma for the Nanyuan Fm., and 104–95Ma for the Shimaoshan Fm. In situ Hf isotope analyses on dated zircon yield an εHf(t) range of −13.8 to +6.9 and a TDM(Hf) range from 1400 to 486Ma with a peak at ca. 930Ma. The majority of the Mesozoic felsic lavas have more radiogenic Hf than that of metamorphic basement rocks and related igneous rocks, requiring the involvement of a juvenile component in their origin. The Mesozoic felsic magmas are predominantly dacites and rhyolites – with only minor basalt and andesite – and show relatively homogeneous Hf isotopic compositions of zircon in single sample. Combined these data indicated that neither differentiation of a mantle-derived magma, nor mixing of magmas from different sources, was a dominant petrogenetic process. Both the εHf(t) of zircon and the magma temperature increase from the Douling and Nanyuan Fms. to the Shimaoshan Fm. All these facts imply an increasing contribution of contemporaneous underplated hot and dry mantle-derived magmas, as both a heat source inducing crustal melting and as a source of material (melt) that variably mixed with the local crustal melts. The felsic crustal melt component was generated at amphibolite-facies conditions with a residual assemblage of plagioclase+/−hornblende+/−garnet+/−zircon. Our results suggest a progressive role of crust–mantle interaction in generating the episodic felsic volcanic eruption during the Mesozoic.

Prevalence and molecular characterization of abnormal hemoglobin in eastern Guangdong of southern China

Abnormal hemoglobins (Hbs) are the most commonly inherited disorders in humans. Their frequency and types change considerably with geographic location and ethnic group. To investigate the molecular epidemiological characterization of abnormal Hbs in eastern Guangdong of southern China, a total of 11,450 'healthy' subjects were subjected to hemoglobin electrophoresis screening. Samples of EDTA-K(2) blood with abnormal Hbs were analyzed by CELL-DYN1700 blood analyzer; thalassemia genotypes and Hb E variant were identified by gap-PCR and/or reverse dot blot (RDB). The genotypes of Hb variants were detected by PCR and sequencing. The incidence of abnormal Hbs was 0.358%(41/11,450) in Chaozhou, including 12.2% (5/41) Hb J, 4.9% (2/41) Hb K, 9.7% (4/41) Hb Q, 31.7% (13/41) Hb G/D and 41.5% (17/41) Hb E. Eight types of Hb variants were found, including 3 cases of Hb J-Bangkok, 2 cases of Hb J-Wenchang-Wuming, 2 cases of Hb New York, 4 cases of Hb Q-Thailand, 5 cases of Hb G-Waimanalo, 4 cases of Hb Ottawa, 4 cases of Hb G-Chinese and 17 cases of Hb E. In comparison with other areas of Guangdong, Chaozhou had a different pattern of abnormal Hbs with a high prevalence of Hb G/D. This study describes the prevalence and molecular characterization of abnormal Hbs in eastern Guangdong.

Spatial-temporal variability patterns of regional runoffs series and their root cause analysis, Guangdong Province

运用最大似然比和西沃兹信息标准的变点识别方法, 对广东省主要江河1956-1999年的年径流量、汛期径流量、枯水期径流量和最小月径流量的年序列, 进行均值变点和方差变点识别, 得出径流量特征值存在变点的序列类型、时间位置、空间分布及时序变点前后的特征值变化状况, 结合广东省降雨量序列变点识别、水利工程设施建设等气候和人类活动影响因素的分析, 以揭示广东省河川径流量时空变异特征及主要成因.结果表明:广东省河川年径流量和汛期径流量序列的一致性较好, 而枯水期径流量和最小月径流量序列的特征值变点具有普遍性, 年均值明显增加, 年际离散程度增大.枯水期径流量序列均值变点的典型时间位置为1973年和1980-1981年, 分布于西江支流贺江、东江、粤东沿海螺河, 由水库等蓄水工程的径流调节作用而形成;方差变点的典型时间位置为1981年, 主要分布于北江、韩江、粤西鉴江、珠江三角洲的增江及网河区顶部干流水道, 与特丰年1982年的枯水期大量降水有关.最小月径流序列主要为均值变点, 不同河流的变点时间位置有较大差异, 但多集中在1972-1973年, 分布于西江支流、东江、韩江及粤东沿海河流、珠江三角洲的增江.珠江三角洲顶部的北江干流水道的径流量变异尤其典型, 四种径流量序列均存在均值变点和方差变点, 典型时间位置为1980-1981年和1992-1993年, 是由网河区剧烈的人类活动改变了河道分流比所导致。;Based on the change-point theory and methods, the likelihood ratio method testing in the mean and the Schwarz Information Criterion testing in the variance, change points of time series of the river runoff such as the full year runoff, the flood season runoff, the dry season runoff, and the least monthly runoff were recognized for main gauge stations of Guangdong Province from 1956 to 1999.Spatial-temporal location of these tested change points were described in detail, key features of the characteristics variability of time series of the river runoff were concluded on the whole, and furthermore root causes were illuminated for those change points of runofif time series in terms of the mean and the variance.In general, it showed that change point was widely tested in the existence of the dry season runoff and of the least monthly runoff, which the annual value increased significantly and fluctuated remarkably after the change-point time, otherwise of the full year runoff and of the flood season runoff.Furthermore, the change-point location in the mean of the dry season runoff obviously occurred to 1973 and 1980-1981 in the Hejiang River of the Xijiang Basin, the Dongjiang River, Luohe River of Eastern Guangdong coast mainly due to reservoirs adjustment, and the change-point location in the variance of die dry season runoff to 1981 in the Beijiang River, the Hanjiang River, Jianjiang RiveT of the Western Guangdong coast, Zengjiang River and the top water channel of the Pearl River Delta, mainly by the reason of the precipitation of the dry season in large quantity in 1982.However, it occurred to 1972-1973 in spite of different change-point temporal location in the mean of the least monthly runoff, widely in Xijiang River and its streams, Dongjiang River, Hanjiang River, Zengjiang River, and rivers of Eastern Guangdong coast.In particular, change-point in the mean and in the variance were tested in the existence of these four kinds of annual series in the top Beijiang channel of the Pearl River Delta due to change of the split flow ratio on the channel net under the intensely human activities.

Diagenesis and Evolution of the Holocene Coquinite from the Haishan Island, Eastern Guangdong, China

Abstract:The coastal hard rock with a thickness of over 5 m and a distribution area of nearly 200 ha in the Haishan Island, south China, has long drawn researchers’attention. However, there were controversies over its formation and classification, and these controversies in turn lead to the dispute of sea level changes and coastal uplift‐subsidence of this area. To investigate its diagenesis and evolution, petrographic analysis, elemental geochemistry, isotopic analysis, and radiocarbon dating were used in the present study. Radiocarbon dating indicates that the deposition of the Haishan Coquinite commenced in the mid Holocene and lasted to ∼600 a B.P. Petrographic analysis shows that the Haishan Coquinite is cemented by low‐Mg calcite, indicating that the cementation occurred in a meteoric environment. The elemental geochemistry and isotopic values demonstrate that the coquinite suffered strong leaching, which was thought to be responsible for the meteoric cementation of the coquinite. According to these results, the diagenesis of the coquinite is revealed: deposition of the Haishan Coquinite commenced in the mid Holocene in a shoal environment, initial cementation occurred and cement may be high‐Mg calcite or aragonite; latterly the coquinite exposed to meteoric environment as a result of lowering of relative sea level, and the cement altered to low‐Mg, which took the morphologies of bladed calcite rim and equant spar. A four‐stage evolution model is proposed: (1) deposition stage, (2) initial cementation, (3) exposure to and cementation in meteoric environment, and (4) erosion stage. The published reports indicate that the hard rock should be designated as coquinite. Based on these studies, mid‐Holocene sea level in this area was discussed, and the Haishan Island was proposed to uplift with a rate of ∼5 mm/a in the last ∼600 a.