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1.
To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions (δ13C and δD values) of long-chain n-alkanes in a peat core from the Shiwangutian (SWGT) peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the δ13C values of the long-chain n-alkanes can be a proxy for humidity, while the δD values of the long-chain n-alkanes primarily recorded the moisture source δD signal during 9–1.8 ka BP and responded to the dry climate during 1.8–0.3 ka BP. Together with the average chain length (ACL) and the carbon preference index (CPI) data, the climate evolution over last 9 ka in the SWGT peatland can be divided into three stages. During the first stage (9–5 ka BP), the δ13C values were depleted and CPI and Paq values were low, while ACL values were high. They reveal a period of warm and wet climate, which is regarded as the Holocene optimum. The second stage (5–1.8 ka BP) witnessed a shift to relatively cool and dry climate, as indicated by the more positive δ13C values and lower ACL values. During the third stage (1.8–0.3 ka BP), the δ13C, δD, CPI and Paq values showed marked increase and ACL values varied greatly, implying an abrupt change to cold and dry conditions. This climate pattern corresponds to the broad decline in Asian monsoon intensity through the latter part of the Holocene. Our results do not support a later Holocene optimum in south China as suggested by previous studies.  相似文献   

2.
A virulent rabies virus (RABV) strain, GD-SH-01, was isolated from brain tissue of a rabid pig in China. This report describes the first complete genome sequence of a swine-origin RABV strain, and this information will provide important insights into the transmission cycle and genetic diversity of RABV from different hosts in China.  相似文献   

3.
Climate Change and War Frequency in Eastern China over the Last Millennium   总被引:5,自引:0,他引:5  
We explore the association between climate change and warfare in eastern China over the past millennium from a macro-historic perspective. High-resolution palaeo-temperature reconstructions and the complete record of warfare incidence in eastern China were compared. Results show that warfare frequency in eastern China (its southern portion in particular) significantly correlated with the Northern Hemisphere temperature oscillations. Almost all peaks of warfare frequency and dynastic changes occurred in cooling phases. We suggest that in historic China, the reduction of thermal energy during cooling phases significantly shrank agricultural production. Such ecological stress interacted with population pressure and China’s unique historic and geographic setting to bring about the high frequencies of warfare over the last millennium. We recommend scholars take climate change into account as they consider the anthropology of warfare in the historic past.  相似文献   

4.
中国柽柳属和水柏枝属的分子系统学研究   总被引:5,自引:3,他引:2  
对中国柽柳科 3属 2 1种植物的核糖体DNA中的内转录间隔区 (ITS)序列及 5 8SrRNA基因的 3′端序列进行测定。结果表明 ,ITS - 1片段的长度范围在 2 5 4bp~ 2 6 9bp之间 ,ITS - 2片段的长度范围在 2 2 5bp~ 2 5 3bp之间。以Reaumuriasongarica作为功能性外类群 ,运用PAUP软件分析仅得到一个最简约树。简约树步长为 4 6 6步 ,一致性指数CI =0 85 84 ,保持性指数RI=0 86 2 2。系统发育分析表明 :秀丽水柏枝不应从水柏枝属中分出。另外 ,研究分析为目前分类上存有争议的白花柽柳、短毛柽柳及甘蒙柽柳的划分提供了分子生物学证据  相似文献   

5.
通过对真蝽属Pentatoma 9种昆虫线粒体COI基因约798bp的序列进行分子进化分析,并以同蝽科宽铗同蝽Acanthosoma labiduroides为外群,采用最大简约法、最大似然法和邻接法构建了分子系统树,来探讨真蝽属的系统发育关系.研究结果支持褐真蝽群P. semiannulata-group的划分,绿角真蝽Pentatoma viridicornuta应划归到褐真蝽群P. Semiannulata-group;红足真蝽群中的角肩真蝽P. angulata与红足真蝽P. rufipes遗传距离较小,它们是否为1个物种值得关注;真蝽属各群之间的系统发育关系以及是否可分为3个属值得进一步研究.  相似文献   

6.
提供了南海大陆坡上17962孔深海沉积物的孢粉记录.该孔长8 m,底部14C年龄为30 000 a BP,跨越了深海氧同位素3期、末次冰期、冰消期和全新世几个地质历史阶段.孢粉记录显示末次冰期低海面时南海南部出露的陆架上覆盖了低地雨林.同时,在邻近的岛屿上山地雨林扩张,表明气候比现在凉,但是没有变干的迹象.冰消期植被和气候都经历了快速变暖和变凉的波动.全新世时,红树林和低地雨林的扩张以及孢粉沉积率的明显降低均表明气候变暖,海面上升,大陆架被淹没.  相似文献   

7.
8.
9.
Molecular typing of Candida albicans is important for studying the population structure and epidemiology of this opportunistic yeast, such as population dynamics, nosocomial infections, multiple infections and microevolution. The genetic diversity of C. albicans has been rarely studied in China. In the present study, multilocus sequence typing (MLST) was used to characterize the genetic diversity and population structure of 62 C. albicans isolates collected from 40 patients from Huashan Hospital in Shanghai, China. A total of 50 diploid sequence types (DSTs) were identified in the 62 C. albicans isolates, with 41 newly identified DSTs. Based on cluster analysis, the 62 isolates were classified into nine existing clades and two new clades (namely clades New 1 and New 2). The majority of the isolates were clustered into three clades, clade 6 (37.5%), clade 1 (15.0%) and clade 17 (15.0%). Isolates of clade New 2 were specifically identified in East Asia. We identified three cases of potential nosocomial transmission based on association analysis between patients’ clinical data and the genotypes of corresponding isolates. Finally, by analyzing the genotypes of serial isolates we further demonstrated that the microevolution of C. albicans was due to loss of heterozygosity. Our study represents the first molecular typing of C. albicans in eastern China, and we confirmed that MLST is a useful tool for studying the epidemiology and evolution of C. albicans.  相似文献   

10.
末次盛冰期环境恶化对中国北方旧石器文化的影响   总被引:10,自引:0,他引:10  
末次冰期间冰段时,中国北方地区水热条件普遍较好,旧石器文化也比较发达。然而,进入末次盛冰期后,随着气温的普遍降低和降水量的明显减少,草原和沙漠带急速向南扩张,动物群也大举南迁。对于这种严酷的生存环境,中国北方的旧石器文化是如何响应的呢?本文以宁夏彭阳PY01-02,PY03和PY05等地点的地层剖面和石制品的研究为基础,首先提出彭阳地点群地层沉积相由河湖相沉积迅速转变为黄土堆积说明由末次冰期间冰段到末次盛冰期自然环境发生了剧烈变化。其次,通过对上述两种不同沉积相中出土石制品的大小、重量、原料以及技术上的比较说明随着环境的变化石制品本身也发生了相应的变化。下层河湖相堆积中出土的石制品粗大笨重,主要以各种石英岩为原料,与同期泾水上游旧石器文化的特征相近,应是当地文化特征的一种具体体现。上层马兰黄土中的石制品的普遍较小,主要以石英和燧石为原料,其中用燧石制成的细石器具有宁夏灵武水洞沟下文化层同类制品的特征,而用石英制成的小石器则同海原一带的史前文化有着较为密切的联系,据此作者推测这可能与史前人类在环境日益恶劣的情况下向南迁移有关。山西南部地区的下川和柿子滩遗址的地层和石制品证据亦表明,末次盛冰期前后该地区旧石器文化的明显差异可能也与末次盛冰期环境恶化时人类的迁徙有关。最后,中国北方地区考古遗址的空间分布变化为上述史前人类南迁的推测提供了有力证据。因此,作者认为末次冰期的环境恶化对中国北方旧石器文化的影响具有普遍性。  相似文献   

11.
提供了南海大陆坡上17962孔深海沉积物的孢粉记录。该孔长8m,底部^14C年龄为30000aBP,跨越了深海氧同位素3期,末次初期,冰消期和全新世几个地质历史阶段。孢偻记录显示末次冰期低海面时南海南部出露的陆架上了低地雨林。同时,在邻近的岛屿上山地雨林扩张,表明气候比较在凉,但是没有变干的迹象,冰消期植被和气候都经历了快速变暖的变凉的波动。全新世时,红树林和低地雨林的扩及孢粉沉积率的明显降低均表明气候变暖,海面上升,大陆架被淹没。  相似文献   

12.
Using the polymerase chain reaction (PCR) and hybridization with oligonucleotide probes, we analyzed the distribution of DPB1 alleles in 99 healthy unrelated individuals from the city of Guangzhou (Canton), South China. Twelve different DPB1 alleles were found in this panel. The most common allele was DPB1*0501 (62.6%). Other major alleles detected included DPB1*02 (DPB1*0201 and DPB1*0202), DPB1*1301, DPB1*0401, and a recently described allele, designated DPB1*2101. The hybridization pattern of DPB1*2101 showed that this allele shared sequences with DPB1*0301 and DPB1*0601 in the A and F hypervariable regions, while the C, D, and E regions were identical to those of DPB1*0202. DPB1*2101 was observed in 11% of the subjects tested. It was found to be in strong linkage dis-equilibrium with DRB1*1202. In family studies, segregation of the haplotype DRB1*1202, DRB3*0301, DQA1*0601, DQB1*0301, DPB1*2101 was observed. The second exon of DPB1*2101 was sequenced from codon 8 to codon 90 and the sequence, inferred from the pattern of hybridization, was confirmed. DPB1*0301, DPB1*0402, DPB1*0101, DPB1*1401, DPB1*1901, and another recently recognized allele, now designated DPB1*2401, were detected with low frequencies. DPB1*2401 had the same hybridization pattern as DPB1*0501 except for a probe that matches codons 85–90. In this region, DPB1*2401 encoded the amino acid sequence GPMTLQ instead of EAVTLQ as in DPB1*0501.  相似文献   

13.
Molecular approach to the identification of fish in the South China Sea   总被引:3,自引:0,他引:3  
Zhang J  Hanner R 《PloS one》2012,7(2):e30621

Background

DNA barcoding is one means of establishing a rapid, accurate, and cost-effective system for the identification of species. It involves the use of short, standard gene targets to create sequence profiles of known species against sequences of unknowns that can be matched and subsequently identified. The Fish Barcode of Life (FISH-BOL) campaign has the primary goal of gathering DNA barcode records for all the world''s fish species. As a contribution to FISH-BOL, we examined the degree to which DNA barcoding can discriminate marine fishes from the South China Sea.

Methodology/Principal Findings

DNA barcodes of cytochrome oxidase subunit I (COI) were characterized using 1336 specimens that belong to 242 species fishes from the South China Sea. All specimen provenance data (including digital specimen images and geospatial coordinates of collection localities) and collateral sequence information were assembled using Barcode of Life Data System (BOLD; www.barcodinglife.org). Small intraspecific and large interspecific differences create distinct genetic boundaries among most species. In addition, the efficiency of two mitochondrial genes, 16S rRNA (16S) and cytochrome b (cytb), and one nuclear ribosomal gene, 18S rRNA (18S), was also evaluated for a few select groups of species.

Conclusions/Significance

The present study provides evidence for the effectiveness of DNA barcoding as a tool for monitoring marine biodiversity. Open access data of fishes from the South China Sea can benefit relative applications in ecology and taxonomy.  相似文献   

14.
A Plio-Pleistocene to Holocene faunal sequence has been recovered from four carefully excavated caves in the Bubing Basin, adjacent to the larger Bose Basin of South China. The caves vary in elevation; we suggest that the higher caves were formed and filled with sediments prior to the lower caves. The highest deposits, which are from Mohui Cave, contain hominoid teeth and other fossilized remains of mammalian taxa most similar to late Pliocene and early Pleistocene faunas. Wuyun Cave ( approximately 50m lower in elevation than Mohui) contains a late middle Pleistocene fauna, which is supported by U-series age constraints from 350 to 200ka. Lower Pubu Cave ( approximately 23m below Wuyun) is assigned to the late Pleistocene, while the Cunkong Cave (the lowest, approximately 2m lower elevation than Lower Pubu) preserves a Holocene fauna. The four faunal assemblages indicate species-level changes in Ailuropoda, Stegodon, and Sus, the appearance of Elephas, the local disappearance of Stegodon, and the migration of Equus hemionus to South China. These initial results of our work call into question the continued value of the Stegodon/Ailuropoda Fauna, a category long used to characterize the Pleistocene faunas of South China. Excavation of karstic caves of varying elevation within the basins of South China holds promise for defining local sequences of mammalian fossils that can be used to investigate faunal variations related to climate change, biogeographic events, and evolutionary change over the past two million years. Stable isotopic analysis of a small sample of mammalian teeth from Bubing Basin caves is consistent with 100% C(3) vegetation in the Bubing/Bose region, with certain delta(13)C values consistent with a canopied woodland or forest. A preliminary assessment of the hominoid teeth indicates the presence of diverse molar and premolar morphologies including dental remains of Gigantopithecus blacki and a sample with similarities to the teeth reported from Longgupo.  相似文献   

15.
A widespread hemorrhagic gastroenteritis in young dogs occurred in South China. A virulent field canine parvovirus (CPV) strain, SC02/2011, was isolated from a puppy showing enteric signs in Guangdong, China. The genome of CPV strain SC02/2011 was sequenced and analyzed, which will promote a better understanding of the molecular epidemiology and genetic diversity of CPV field isolates in South China.  相似文献   

16.
The superfamily Dytiscoidea contains six families with an aquatic lifestyle, with most of its extant diversity in two families: the burrowing water beetles (Noteridae) and the diving beetles (Dytiscidae). The other families have few species (up to six) and generally highly disjunct extant distributions. Aspidytidae currently contains one genus with two species, one in China and one in South Africa. Here we provide the first molecular data for the Chinese species, allowing us to explore the phylogenetic relationships and position of both species of this small family for the first time. Based on a matrix of 11 genes we inferred a phylogenetic hypothesis for Dytiscoidea including all extant families. Unexpectedly, Aspidytidae were consistently recovered as paraphyletic relative to Amphizoidae, despite being well characterized by apparently synapomorphic adult features. A re‐examination of larval characters in the two aspidytid species revealed that the larva of the Chinese species is strikingly similar to that of Amphizoidae. Both share a series of plesiomorphic features but also some potential synapomorphies, including a dense vestiture of short setae on the head capsule, anteriorly shifted posterior tentorial grooves and widely separated labial palps. Arguably these features may belong to the groundplan of the clade Aspidytidae + Amphizoidae, with far‐reaching secondary modifications (including reversals) in the South African Aspidytes niobe. At present we retain the family Aspidytidae, however, due to the strong adult morphological synapomorphies of the two extant species, and the fact that the molecular paraphyly of the family may result from the highly divergent nature of the two extant species. This long evolutionary separation and strong divergence, in terms of gene sequences and larval features, is undeniable, substantial levels of saturation in third codon positions of protein‐coding genes being present between the two taxa. We address this issue taxonomically by introducing the new genus S inaspidytes gen. nov. for the Chinese Aspidytes wrasei. The continued contentious relationships amongst Dytiscidae, Hygrobiidae, Aspidytidae and Amphizoidae highlight the need for more data to address dytiscoid phylogenetics, possibly involving a genomic approach. © 2016 The Linnean Society of London  相似文献   

17.
High-resolution sea surface temperatures (SST) derived from Mg/Ca ratios of Globeriginoides sacculifer at ODP Site 1144 were reported to reveal the SST changes during the last 260 ka in the northern South China Sea (SCS). The results indicate an average Holocene SST of about 26.7 °C, about 3.6 °C increase from LGM to the Holocene, and higher temperature during MIS 5.5 than the Holocene. These agree well with other foraminifer Mg/Ca and Uk37 SST records in this region. The Mg/Ca records suggest warmer SSTs during MIS 3 in the northern SCS, compared with those in the eastern Pacific. Strong East Asian summer monsoon during MIS 3 indicated by paleoclimate records from nearby continents may account for it. Step-wise increases during terminations are shown in our SST record, and the beginning of deglacial warming occurs at about 19 ka, which precedes the change of oxygen isotopes, suggesting a tropical driven forcing for the SST change in the northern SCS. This is further supported by a robust semi-precessional cycle centering at  9.1 ka in the spectra of the SST record, which is absent in that of the oxygen isotopes. However, tropical driven forcing seems not to be indicated in another Mg/Ca SST record in the northern SCS [Oppo, D.W. and Sun, Y.B., 2005. Amplitude and timing of sea-surface temperature change in the northern South China Sea: Dynamic link to the East Asian monsoon. Geology, 33 (10): 785–788.]. The discrepancy may be caused by different post-deposition dissolutions of foraminifer tests at these two sites. Details about the modification of foraminifer Mg/Ca ratios after burial, however, are not well known in this region, and further studies are needed.  相似文献   

18.
Objective: To describe the 25‐year changes in BMI (measured in kilograms per meters squared) and the prevalence of obesity in Japanese children with special reference to urban‐rural differences. Research Methods and Procedures: We used the data sets from the cross‐sectional annual nationwide surveys (National Nutrition Survey, Japan) conducted from 1976 to 2000 and comprising 29, 052 boys and 27, 552 girls between 6 and 14 years of age. We carried out the trend analyses with the data on sex and age groups and on residential areas according to the size of the municipality (metropolitan areas, cities, and small towns). Results: The mean (age‐adjusted) BMI increased by +0.32 kg/m2 per 10 years in boys and by +0.24 kg/m2 per 10 years in girls, increases that were remarkable in small towns. The prevalence of obese boys and girls increased from 6.1% and 7.1%, respectively, in the time‐period 1976 to 1980, to 11.1% and 10.2% in 1996 to 2000. The increasing trend was most evident in 9‐ to 11‐year‐old children of both sexes living in small towns, whereas no changes were observed in girls in metropolitan areas. Discussion: Our data clearly show increasing trends in obesity prevalence in Japanese school children. Degrees of the increasing trends, however, differed across sex and age groups and residential areas, demonstrating a particular phenomenon that girls in metropolitan areas were unlikely to become obese. These epidemiological aspects indicate the priorities for intervention in population strategies to control obesity in children.  相似文献   

19.
Vegetation on the emerged continental shelves of the South China Sea (SCS) during the Last Glacial Maximum (LGM) was deduced based on pollen of hemipelagic sediments from the continental slopes and the consideration of pollen transport dynamics and source areas. During the LGM (including the top of Oxygen Isotope Stage 3) the sea level might be more than 100 m lower than that of the present. Consequently, both northern and southern continental shelves of the SCS were exposed. The northern continental shelf was covered by grassland mainly of Artem/s/a. The climate should be cold and dry, whereas on the southern continental shelf (Sunda Land) was spread tropical lowland rainforest and mangroves were scattered by the river mouths and along the coast. The climate might be cooler than that in the present day, but drop of humidity was not observed.  相似文献   

20.
《Ostrich》2013,84(2):227-234
A collection of almost 830 specimens of birds and their eggs was made at Deelfontein, Northern Cape province, South Africa, in 1901 and 1902, by two soldiers who had enlisted in the Yeomanry during the South African (Boer) War. A total of 151 bird species has been recorded in the Deelfontein area in two periods, 1901–1902 and 1987–1992. There has been no apparent change in occurrence in 82 species, but 40 species were recorded only in 1901–1902, and 29 species were recorded only by observers who completed field cards for the area for the SABAP surveys in 1987–1992. It is suggested that the differences in bird species composition are most likely associated with anthropogenic influences including land-use changes and over-utilisation of shrublands as grazing for domestic livestock.  相似文献   

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