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Fossil fauna and transgressive.sequence from core QC2 in the South Huanghai Sea
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作者 Zhu Xionghua and Lin Hemao Institute of Marine Geology, Ministry of Geology and Mineral Resources, Qingdao, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第4期561-578,共18页
According to palaeoenvironmental analysis on the fossil fauna dominated by Foraminifera and Ostracoda, core QC2 contains 8 marine transgressive beds, called (from up to bottom) Transgressive Beds Ⅰ,Ⅱ, Ⅲ, …,Ⅷ resp... According to palaeoenvironmental analysis on the fossil fauna dominated by Foraminifera and Ostracoda, core QC2 contains 8 marine transgressive beds, called (from up to bottom) Transgressive Beds Ⅰ,Ⅱ, Ⅲ, …,Ⅷ respectively. Together with dating data, the transgressive sequence since 1. 7 Ma B. P. has been established, indicating that the core went through middle and late Early Pleistocene, early and late Middle Pleistocene, early and late (Substages A and B) Late Pleistocene and the Holocene transgressions. Within these 8 transgressions, late Middle Pleistocene, early Late Pleistocene and the Holocene transgressions-had rather strong activities proved by shallow sea (of 50 or 20-50 m water depth) deposits in the prime, while 2 of the 8, during middle Early Pleistocene and late Late Pleistocene (Substage A), were much weaker only with supratidal deposits. The transgressive cycles also differ from each other. Transgressions in the Holocene and in Substage B of late Late Pleistocene are made up of 3 and 2 subcycles of marine ingressions and regressions respectively, but most transgressions only have a single ingressive or regressive sequence. With the core, some important problems concerning, the study of Quaternary transgression such as correlation of transgressive beds and climatic periods and dating of the transgressive beds are discussed in this paper. 展开更多
关键词 Fossil fauna and transgressive.sequence from core QC2 in the South Huanghai Sea core QC
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On Some New Paranormed Euler Sequence Spaces and Euler Core 被引量:1
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作者 Serkan DEMIRIZ Celal CAKAN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第7期1207-1222,共16页
In this paper, the sequence spaces e0^τ(u, p) and ec^τ(u, p) of non-absolute type which are the generalization of the Maddox sequence spaces have been introduced and it is proved that the spaces e0^τ(u,p) and... In this paper, the sequence spaces e0^τ(u, p) and ec^τ(u, p) of non-absolute type which are the generalization of the Maddox sequence spaces have been introduced and it is proved that the spaces e0^τ(u,p) and ec^τ(u,p) are linearly isomorphic to spaces co(p) and c(p), respectively. Furthermore, the α-, β- and γ-duals of the spaces 0^τ(u,p) and ec^τ(u,p) have been computed and their bases have been constructed and some topological properties of these spaces have been investigated. Besides this, the class of matrices (e0^τ)(u, p) : μ) has been characterized, where μ is one of the sequence spaces l∞, c and co and derives the other characterizations for the special cases of μ. In the last section, Euler Core of a complex-valued sequence has been introduced, and we prove some inclusion theorems related to this new type of core. 展开更多
关键词 sequence spaces matrix transformations core of a sequence
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Public health implications of Yersinia enterocolitica investigation:an ecological modeling and molecular epidemiology study 被引量:1
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作者 Yuan Yue Jinxin Zheng +10 位作者 Mei Sheng Xiang Liu Qiong Hao Shunxian Zhang Shuai Xu Zhiguo Liu Xuexin Hou Huaiqi Jing Yang Liu Xuezhang Zhou Zhenjun Li 《Infectious Diseases of Poverty》 SCIE CAS CSCD 2023年第2期134-135,共2页
Background Yersinia enterocolitica has been sporadically recovered from animals,foods,and human clinical samples in various regions of Ningxia,China.However,the ecological and molecular characteristics of Y.enterocoli... Background Yersinia enterocolitica has been sporadically recovered from animals,foods,and human clinical samples in various regions of Ningxia,China.However,the ecological and molecular characteristics of Y.enterocolitica,as well as public health concerns about infection in the Ningxia Hui Autonomous Region,remain unclear.This study aims to analyze the ecological and molecular epidemiological characteristics of Y.enterocolitis in order to inform the public health intervention strategies for the contains of related diseases.Methods A total of 270 samples were collected for isolation[animals(n=208),food(n=49),and patients(n=13)],then suspect colonies were isolated and identified by the API20E biochemical identification system,serological tests,biotyping tests,and 16S rRNA-PCR.Then,we used an ecological epidemiological approach combined with machine learning algorithms(general linear model,random forest model,and eXtreme Gradient Boosting)to explore the associations between ecological factors and the pathogenicity of Y.enterocolitis.Furthermore,average nucleotide identity(ANI)estimation,single nucleotide polymorphism(SNP),and core gene multilocus sequence typing(cgMLST)were applied to characterize the molecular profile of isolates based on whole genome sequencing.The statistical test used single-factor analysis,Chi-square tests,t-tests/ANOVA-tests,Wilcoxon rank-sum tests,and Kruskal–Wallis tests.Results A total of 270 isolates of Yersinia were identified from poultry and livestock(n=191),food(n=49),diarrhoea patients(n=13),rats(n=15),and hamsters(n=2).The detection rates of samples from different hosts were statistically different(χ^(2)=22.636,P<0.001).According to the relatedness clustering results,270 isolates were divided into 12 species,and Y.enterocolitica(n=187)is a predominated species.Pathogenic isolates made up 52.4%(98/187),while non-pathogenic isolates made up 47.6%(89/187).Temperature and precipitation were strongly associated with the pathogenicity of the isolates(P<0.001).The random forest(RF)prediction model showed the best performance.The prediction result shows a high risk of pathogenicity Y.enterocolitica was located in the northern,northwestern,and southern of the Ningxia Hui Autonomous Region.The Y.enterocolitica isolates were classified into 54 sequence types(STs)and 125 cgMLST types(CTs),with 4/O:3 being the dominant bioserotype in Ningxia.The dominant STs and dominant CTs of pathogenic isolates in Ningxia were ST429 and HC100_2571,respectively.Conclusions The data indicated geographical variations in the distribution of STs and CTs of Y.enterocolitica isolates in Ningxia.Our work offered the first evidence that the pathogenicity of isolates was directly related to fluctuations in temperature and precipitation of the environment.CgMLST typing strategies showed that the isolates were transmitted to the population via pigs and food.Therefore,strengthening health surveillance on pig farms in high-risk areas and focusing on testing food of pig origin are optional strategies to prevent disease outbreaks. 展开更多
关键词 Yersinia enterocolitica ECOLOGICAL Machine learning Molecular epidemiology core genome multilocus sequence typing Ningxia China
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