Quantitative evaluation of elbe river-derived organic marker compounds in sediment samples from the german bight

Background, Goal and Scope  A large share of anthropogenic contamination of the coastal zone is a result of riverine contributions. Accordingly, the pollution of North Sea estuaries and coastal areas by organic xenobiotics is dominantly characterized by land-derived contamination. In a previous study, we identified a high number of organic contaminants in sediments of the German Bight emitted by industrial and municipal sources, primarily as a result of riverine contributions. Furthermore, a group of contaminants was identified representing Elbe-specific marker compounds. However, quantitative analyses are more adequate to describe the source specificity via the spatial distribution as compared to qualitative analyses. Hence, in the present investigation, the determination of various anthropogenic contaminants has been performed in order to evaluate the proposed Elbe-specific marker compounds. Methods  Numerous anthropogenic contaminants were quantified in seven surface sediment samples from the German Bight by means of gas chromatographic — mass spectrometric analyses. The analytical procedure includes extraction, reI moval of sulphur, fractionation, concentration and addition of internal standard. Results and Discussion  Two groups of Elbe-derived contaminants were differentiated. Substances of the first group appear only at sampling locations directly influenced by the Elbe river and include hexachlorobutadiene and alkylsulfonic acid phenyl esters. The second group consists of compounds, which occur additionally in minor concentrations at sites situated at a greater distance from the coastal area, which are therefore only influenced to a minor-degree by the Elbe river. However, their spatial and quantitative distribution characterizes them clearly as Elbe river-derived components. Compounds of the second group are tetra- to hexachlorinated benzenes, mono- and disubstituted chloronaphthalenes, tetrabutyltin, 4,4’-dichlorodiphenylsulfide and DDT related compounds In order to discern the discussed Elbe marker compounds from non-marker substances, several nonspecific contaminants were analyzed additionally. These contaminants include galaxolide, tonalide, tri-n-butylphosphate, 2,4,4-trimethylpentane-l,3-dioldi-iso-butyrate and 2,2,4,4,6,8,8-heptamethylnonane. No significant accumulation of these compounds was observed at sampling locations mainly influenced by either the Elbe river, or the Ems and Weser rivers. Conclusions  For the evaluation of the proposed Elbe marker compounds, the quantitative and spatial distribution was investigated and successfully discussed as the most important criterion to define their source specificity. Generally, these results illustrate how quantitative data on source-specific organic contaminants and the corresponding spatial distribution can be used to trace individual riverine contributions to the pollution of coastal areas. This approach might be especially useful to differentiate the contribution of several rivers discharging close together into the marine environment. Fingerprinting, the individual riverine contribution additionally allows one to quantify the individual, river-derived contamination. Subsequently, the level of coastal zone contaminations can be reduced more effectively. Further comprehensive analyses on numerous coastal and estuarine areas have to be done to support this approach.     

Testcross performance and diversity analysis of white maize lines derived from backcrosses containing exotic germplasm

Introgression from exotic maize (Zea mays L.) into adapted breeding pools can broaden and diversify the genetic base of adapted germplasm. The first objective of this study was to determine the agronomic performance of white maize lines derived from adapted × exotic backcrosses in tropical environments. Six exotic white maize inbred lines were crossed to an adapted white line (1368) and the F₁s were backcrossed to 1368. Forty-one BC₁F₄ lines derived from these backcrosses and the recurrent parent were crossed with a common inbred tester (9071) and the progeny were evaluated at eight environments in Nigeria. The testcrosses × environment interaction mean square was not significant for all agronomic traits. The BC-derived lines containing exotic germplasm contributed significantly to the variation in testcross mean grain yields and other agronomic traits. Among the 41 testcrosses, only 5 yielded significantly less than 1368 × 9071, with the 7 best testcrosses producing between 304 and 867 kg ha⁻¹ more grain than 1368 × 9071. The second objective of this study was to assess the genetic divergence of the BC-derived white lines from their adapted recurrent parent. Thirty-nine BC-derived white lines along with 1368 and 9071 were genotyped with ten AFLP primer pairs that generated 506 polymorphic fragments. The average allelic diversity of the lines was 31 ± 0.07. The genetic distance (GD) estimates of each BC-derived line from 1368 varied from 0.76 to 0.84, with a mean of 0.80 ± 0.003. The average GD for all pairs of the BC-derived lines was 0.63 ± 0.005, varying from 0.31 to 0.89. The observed significant amount of variation among the BC-derived white lines suggests that they can contribute new alleles for expanding the genetic base of tropical maize and for developing high-yielding hybrids.     

白花草木樨半同胞家系的生物固氮性状评价

以不同的白花草木樨(Melilotus albus)半同胞家系为试验材料,分别种植于甘肃临泽和榆中,测定其根干重、根瘤数、根瘤重、叶全氮、叶全磷和生物固氮百分率,以此评价其生物固氮能力。结果表明,白花草木樨在两个地区表现出的各项固氮指标变异系数均大于15%,主成分分析后,可将半同胞家系划分为4组,组1白花草木樨家系的根干重、根瘤数、根瘤重、叶全氮、叶全磷和生物固氮百分率分别高出对照当地白花草木樨品种(RX-02)4%、26%、10%、17%、24%、11%,其中生物固氮百分率的最大值和最小值分别为58%和43%。本研究筛选出的优良生物固氮性状的后代家系,可为进一步选育生物固氮能力强的新品种奠定基础。     

Chelex-100快速提取动物源饲料DNA方法的建立

为防止疯牛病疫区反刍动物源性饲料传入我国,非常有必要对贸易往来中的肉骨粉品种来源进行鉴定。本文建立了一种利用Chelex—100快速提取动物源性饲料DNA的方法,用于反刍动物源性饲料的PCR扩增分析。结果显示该方法与GuSCN法、SDS法同样理想,从而实现了对进境饲料的快速检定的要求。该方法检测灵敏度达到牛成分含量为0．1％的水平,具有简单、快捷、灵敏度高的优点。     

我国与CAC动物源性产品中药物残留限量的对比分析

国际食品法典委员会(Codex Alimentarius Commission,简称CAC)承担贸易仲裁的工作,CAC标准体系中制定了较多的产品质量标准,并将动物源性产品中药物残留规定统一到CAC/MRL2。重点对已有限量的动物源性产品中药物种类及残留限量值进行比较,将CAC中CAC/MRL2及我国农业部235号公告附录2中的内容进行比较,以期为今后不断健全和完善我国动物源性产品中药物残留法律法规、标准体系、检测手段,并为提高产品质量及扩大生产出口提供参考。     

Monitoring shallow methane‐derived authigenic carbonate: Insights from a UK Marine Protected Area

1. Methane‐derived authigenic carbonate (MDAC) is a biogenic rocky substrate formed by microbial assemblages below the seabed. It performs important ecosystem functions, including the provision of reef‐like habitats on soft sediments and the sequestration of carbon.
2. The protection of MDAC is limited at the global scale; however, 27 marine protected areas (MPAs) have been designated in European waters for ‘cold seep’ MDAC, mainly in shallow waters (<200 m). Few studies have been conducted on these habitats from a conservation perspective.
3. The effective management of MDAC structures requires an understanding of their ecology and physical characteristics in a healthy condition. This is best achieved using a multidisciplinary approach to provide evidence on predefined aspects of MDAC structures, termed feature attributes, which can be assessed to determine habitat condition over time.
4. This article presents the first UK effort to develop a multidisciplinary approach to monitoring shallow MDAC feature attributes, using the Croker Carbonate Slabs Special Area of Conservation (SAC) as a case study. A range of remote and physical survey methods were used to characterize the MDAC and associated relatively unimpacted and healthy biological communities.
5. The data confirm that the SAC contains the largest known area of shallow MDAC in European waters, that methane release is ongoing, and that MDAC is still likely to be forming. Specialized chemoautotrophic fauna were not recorded, possibly due to the dominance of fauna that derive carbon (ultimately) from photosynthesis. Five epifaunal taxa were found to be associated with MDAC, but not with the surrounding sediments.
6. The broad multidisciplinary survey allowed a detailed characterization of shallow MDAC but was resource intensive. We recommend a low‐resource monitoring strategy to deliver cost‐effective and robust evidence for condition assessment and suggest further studies to contextualize future interpretations of change.

     

建立隶属函数的实用方法

隶属函数是模糊数学理论的基石,也是模糊数学应用中的关键问题。而隶属函数的确定又无一般模式可循,这给应用模糊数学的实际工作者带来困难,致使一些应用实例中,对所论模糊集隶属函数的选定或缺乏充分依据,或与概率混为一谈。本文在剖析隶属函数含义的基础上,建立了普通集的导出模糊集的概念,从而阐明了一类统计指标的隶属度本质,为模糊数学与统计学的结合提出一个途径,并从实用的角度说明了建立隶属函数的常用方法。     

IRRI野生稻渗入基因系稻瘟病、白叶枯病、褐飞虱抗性鉴定

对65份从IRRI引进的野生稻渗入基因系进行稻瘟病、白叶枯病及褐飞虱抗性鉴定,筛选出34份抗稻瘟病品系,15份高抗白叶枯病品系,35份中抗白叶枯病品系,21份抗褐飞褐飞虱的品系,44份中抗褐飞虱品系,30份兼抗2种病虫害的品系和27份兼抗2种病虫害的品系,以期为育种利用提供新的抗源。     

运用SYBR Green Ⅰ熔解曲线法检测饲料中牛、羊源性成分的研究

试验旨在建立SYBR Green Ⅰ熔解曲线法对饲料中牛、羊源成分进行检测,以SYBR GreenⅠ为荧光染料,通过优化PCR反应体系,提高了检测灵敏度。在随机抽检的145批样品中,与国标法（GB/T20190-2006）相比,SYBR GreenⅠ熔解曲线法的准确性达到了100%,此方法可作为饲料中牛羊源成分检测的一种方法。     

牛肉、玉米秸秆、精料及水中药残留的检测及分析

采集新疆伊犁地区铁列克萨依山放牧牛群的牛肉样及同批次农区育肥之后屠宰的牛肉样进行检测分析,同时采集农区玉米秸秆、混合精料和水样。将采集到的样品采用高效液相色谱法(HPLC)对阿苯哒唑、伊维菌素和呋喃丹进行检测,这3种物质均未在所检样品中检出。