Observations on the seasonal and yearly occurrence and the distribution ofAtyaephyra desmaresti (Millet, 1831) (Crustacea,Decapoda, Natantia) in The Netherlands

Summary The seasonal occurrence ofAtyaephyra desmaresti in The Netherlands has been studied by sampling the cooling-water filtering screens of power stations situated along the rivers Rhine and Meuse. The shrimps were only found in large numbers at the two power stations with vegetation in the cooling-water intake areas. Fluctuations in the seasonal occurrence showed great similarity for these two localities. Highest numbers of shrimps were impinged in November. High numbers also occurred in September, while a lower peak in numbers was found in May.Changes in the numbers of records during the last 30 years in The Netherlands were compared with climatological fluctuations (severe or mild winters), indicating that this mainly southern-European species is living here at the limits of its ecological and geographical range.The distribution in The Netherlands reveals thatAtyaephyra desmaresti mainly occurs in freshwater habitats, although it tolerates higher chlorinities.     

厚孢孔菌属一新种

本文报道了厚孢孔菌属(Pachykytospora)的一个新种,即大厚孢孔菌Pachykytospora major G.Y.Zheng et Bi和一个国内新记录:瘤厚孢孔菌Pachykytospora tuberculosa(DC.:Fr.)Kotl.et Pouz.。     

A short history of nuclear activation analysis

The major developments in the field of nuclear activation analysis, from 1936 to 1989, are discussed. The developments are grouped into five consecutive time periods. The impact of various scientists on the development of the field in the first 35 years is also discussed.     

Sequence of the immunoregulatory early region 3 and flanking sequences of adenovirus type 35

Adenovirus type 35 (Ad35) is an important pathogen in immunosuppressed individuals such as AIDS patients and bone marrow transplant recipients. Ad35, a member of Ad subgroup B, differs with respect to pathogenic properties from the more fully characterized subgroup C Ad, such as Ad2 and Ad5. One region of human Ad which varies between subgroups and which may influence Ad pathogenesis is early region 3 (E3), a region which appears to modulate the immune response to Ad infection. In order to begin to characterize the differences between the Ad35 E3 and the E3 of other Ad, the complete DNA sequence of the Ad35 E3 promoter and coding sequence along with two flanking structural proteins, pVIII and fiber, has been determined. Ad35 contains open reading frames which are unique to the subgroup B Ad in addition to the four characterized immunoregulatory proteins encoded by the subgroup C Ad. Further evaluation of the sequence of one of these proteins, 18.5K, which is the class-I major histocompatibility complex (MHC) binding protein of 18.5 kDa, demonstrates that the amino acid sequence of this Ad2 gp19K homologue fits a proposed model of gp19K-MHC interaction. Analysis of promoter sequences demonstrates that an NF-κB site found in the subgroup C E3 promoter is absent from the Ad35 E3 promoter. In addition, the fiber genes of Ad35 and other subgroup B Ad have been shown to diverge in an unexpected way, yielding three clusters of fiber homology.     

Molecules and Morphology,Phylogenetics and Genetics

Various explanations can be offered for the incongruence between phylogenetic hypotheses resulting from morphological and molecular data sets. Of these, the possibility that incongruence may result from the mutation of major morphogenetic genes leading to dramatic morphological divergence unaccompanied by equivalent change of the phylogenetic marker molecule(s) used is discussed in detail. As evidence for this hypothesis, several examples for such incongruence are surveyed. It seems possible that in many cases the genetic basis of the morphological characters responsible for the incongruence found may be simple, and that the genes involved may be homologous to genes known from mutant systems. It is suggested that: 1. the systematic documentation of incongruence between molecular and morphological phylogenies may help to assess the frequency of evolutionary change through the mutation of major morphogenetic genes, and that 2. the identification of major morphological characters distinguishing closely related taxa with mutant phenotypes known from mutant systems eventually may allow an experimental approach to the problem of evolutionary change resulting from major genes. Natural taxa suspected to be the result of such processes could be changed morphologically through transformation with the relevant genes.     

Discrimination Amongst Leishmania by Polymerase Chain Reaction and Hybridization with Small Subunit Ribosomal DNA Derived Oligonucleotides

ABSTRACT. A method for discriminating among Leishmania is described, based upon small subunit ribosomal DNA sequence differences. The method was to amplify the entire 2.2 kb small subunit rDNA by polymerase chain reaction using conserved primers specific for the 5' and 3' termini of the small subunit ribosomal RNA, and then hybridize the product dotted onto nylon membranes with labeled oligonucleotides. The design of the hybridization probes was based upon complete small subunit rDNA sequences from L. amazonensis, L. major and L. guyanensis and partial sequences of L. mexicana, L. braziliensis, L. tropica and L. chagasi. A high degree of sequence similarity (> 99%) among species was found. However, sufficient sequence divergence occurred to permit the design of internal oligonucleotide probes specific for species complexes. This procedure successfully discriminated amongst a wide range of Leishmania isolates. The method detected as few as 10 cultured organisms and detected parasites in tissue samples from experimentally infected animals. Non-radioactive labeling showed the same specificity and sensitivity as radioactive probes.     

基于主体功能区的长江经济带绿色发展评价与问题区域识别

长江经济带已成为我国推进绿色发展的重要阵地。基于主体功能区视角,构建以水系统为纽带的长江经济带绿色发展评价指标体系,采用综合加权法、空间自相关、耦合协调度模型等方法探究2018年长江经济带130个城市绿色发展及各子系统耦合协调水平的空间格局,并对绿色发展的问题区域进行分类识别。结果表明：(1)长江经济带绿色发展水平呈由下游、中游至上游递减趋势;各主体功能区绿色发展指数表现为优化开发区>限制开发区>重点开发区。(2)绿色发展各子系统耦合协调度值位于0.365—0.656之间,多处于濒临失调和勉强协调的临界区间,耦合协调水平整体偏低。(3)从长江经济带整体来看,长江中上游地区绝大部分城市绿色发展主要受资源利用和产业发展水平偏低,及由此带来的生态和生活问题限制,且长江中上游地区各省会或直辖市对区域内其他城市绿色发展带动能力不足。从主体功能区视角来看,优化开发区以生态问题为主,仅上海和嘉兴两市;重点开发区以生态和生产问题为主,集中于武汉都市圈和成渝双城经济圈内部;限制开发区以生产和生活问题为主,主要位于省际边界型城市地区。最后综合问题识别结果,分别对长江经济带各主要问题区域绿色发展...     

Genotype and phenotype associations with drought tolerance in barley tested in North Africa

A review is presented of genetic strategies deployed in a 3-yr project on drought tolerance in barley. Data were collected on genetic, physiological and agronomic traits in non-irrigated and irrigated field trials in Egypt, Morocco and Tunisia. A wide range of barley germplasm (developed from African and European cultivars, adapted landraces and wild barleys) was tested, and positive traits were found in each gene pool. The contrasting environments of the three North African countries had major effects on plant/genotype performance. Genetic effects were also detected, as were genotype × environment interactions. A range of strategies were deployed to investigate the physiology and genetics of quantitative traits associated with field performance. Quantitative trait locus (QTL) analysis was performed using backcross lines, recombinant inbred lines and doubled haploid mapping populations. A detailed genetic map was generated in the Tadmor × (ER/Apm) recombinant inbred lines, an important mapping population specifically developed by ICARDA (Centre for Agricultural Research in Dry Areas) and CIMMYT (International Maize and Wheat Improvement Center) to study drought. Quantitative trait loci (QTLs) for grain yield and other important morphological and physiological traits were also identified in a population of doubled haploids derived from F2BCj plants from a cross between a cultivar and a wild barley accession. Significantly, the wild parental line was found to contribute a number of positive alleles for yield. Effects of major developmental genes could explain many of the responses observed. QTLs were found to cluster around major genes controlling flowering time (sghI), plant stature (sdwI and arie.GP) and ear type (vrsl), and it is highly likely that the associations represent pleiotropic effects. Some QTLs were associated with candidate genes such as dehydrins and rubisco activase. One of the most significant results was the identification and generation of material that out performed the best local standards in the three participating North African countries; the selected lines have now entered local breeding programmes. The strategies adopted provided information on physiological traits, genotypes and genetic markers that could be used for marker-assisted selection. Target QTLs and their associated genetic markers may be deployed in marker assisted selection programmes to match crop phenology to the field environment.     

一类新内含子的研究状况

在真核细胞基因组中发现一类新内含子——AT-AC内含子, 除结构特征与普遍存在的核mRNA前体内含子有明显不同外,剪接机制上也存在一定差异.文章介绍了该内含子的分布,结构特征及剪接机理,并与主内含子作了相应比较.