Presence and distribution of PAHs,PCBs and DDE in feed and sediments under salmon aquaculture cages in the Bay of Fundy,New Brunswick,Canada

• 1. Wastes from feed and faeces can result in the deposition of contaminants in sediments around aquaculture sites. Five types of feed pellet, a commercial fish oil and 76 sediment samples collected under and up to 100 m away from salmon aquaculture cages in the south‐western Bay of Fundy between 1998 and 2000 were analysed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and chlorinated pesticides.
• 2. Five alkylated naphthalenes (aNAs) were consistently detected in fish oil (116–180 ng g^?1, per aNA), in pellets (25–51 ng g^?1, dry weight, per aNA), and sediments (<1–45 ng g^?1, dry weight, per aNA). Other PAHs were detected at variable levels in feed or in sediments.
• 3. IUPAC congener 153 (a PCB) and p,p′‐dichlorodiphenyldichloroethylene (p,p′‐DDE) were detected more frequently than other chlorinated targets in oil (108 ng g^?1 and 176 ng g^?1 respectively), feed (<1–14 ng g^?1 and 1.7–28.2 ng g^?1 respectively) and sediments (<0.08–3 ng g^?1 and <0.5–7 ng g^?1 respectively).
• 4. Trends were observed during the first year of sediment sampling (1998), with higher organic carbon, PCBs and p,p′‐DDE levels below the cages than 50 m away. The PAHs other than aNA showed an opposite trend with distance. In 1999, levels of p,p′‐DDE and PCBs were somewhat reduced under the cages, but were detected up to 100 m away from the cages.
• 5. Levels of aNA tended to be higher at some sites in 1999 relative to 1998, reflecting variability in feed and/or differential transport or degradation of contaminants relative to the environmental background. When detected, mean levels of PCBs and DDE were 2–10 times lower in 2000 than in 1999, and PAHs were 30–40% lower in 2000 than in 1999.
• 6. Interpretation of the results is done cautiously, since the exact locations of the sites sampled is only known to an intermediate facilitating the work between farmers and scientists. Levels of contaminants are compared with international results, interpreted relative to potential toxicity, uptake from feed, from deposited sediments, and in the framework of an aquaculture decision‐support system published recently.

Copyright © 2005 John Wiley & Sons, Ltd.     

Organochlorine and Metal Accumulation in Fish (Phoxinus phoxinus) Along a North-South Transect in the Alps

Southern populations of the European minnow fromremote oligotrophic mountain lakes along an Alpinenorth-south transect accumulated more p,p DDE andPCBs than northern populations. As these semi-volatileorganochlorines predominantly evaporate in warmcountries, higher rates of condensation (deposition)are assumed to occur in the southern slopes of theAlps. The higher accumulation of lead and cadmium insouthern population is rather attributed to geogenicand specific environmental impacts than to atmosphericdeposition. Increasing liver ratios of [glutathionedisulfide]/[glutathione], a potential indicator foroxidative stress, from north to south reflect thegenerally higher toxic load at remote sites at thesouthern edge of the Alps. However, histopathologicalchanges in the liver did not correlate withaccumulated toxicants indicating that deposition doesnot lead to severe lesions but induces specificmechanisms for detoxification.     

非国标微型电机综合测试台系统

设计了一种新型的非国家标准微型电机综合测试台系统。该系统以VisualBasicforWINDOWS3．2为软件平台,采用DDE,DLL新技术,通过检测电机的电流、电压和转矩、转速等参数,计算出其输出功率和效率,并依据这些参数判断电机是否合格。以直而电机为对象的现场实验结果表明,该系统可满足厂家的需求。     

基于组态王和Matlab的双容水箱液位控制

为了将复杂控制算法应用到实践中,提出利用DDE(动态数据交换)技术实现Matlab与组态王之间的数据通讯,结合了Matlab强大的运算能力和组态王软件的数据采集、系统监控方面的优势。并将其应用到AE3000型过程控制实验系统中,采用自校正PID控制算法实现双容水箱液位的控制,取得良好的控制效果。     

VFP环境下构建三层客户/服务器系统

主要介绍了三层客户／服务器的概念系统结构以及如何在VFP中创建一个OLE服务器作为中间层从而实现三层的客户／服务器系统。     

基于GIS灌溉系统的应用研究

GIS与实时控制系统集成是GIS的重要应用之一。本文以MAPINFO作为GIS平台，采用MAPINFO的DDE技术通过高级编程语言Delphi实现了与PLC的链接，完成了两者的集成。并在灌溉系统中得到应用。     

利用ADS开发Auto CAD软件在机械设计中的应用

阐述了利用ADS开发Auto CAD 与Excel 工作表之间的动态数据交换，真正实现了系列化产品CAD的交互式参数化绘图，为基于Auto CAD 的机械产品设计提供了一种灵活、有效的方法，优化了Auto CAD 开发系统。     

基于工控机的日光温室灌溉自动控制系统的开发

针对日光温室微灌设备设计了一种基于工控机的灌溉自动控制系统。系统以工控机为核心，采用分布式远程模块完成数据的采集与控制信号的发送。系统底层的控制程序由VB开发，通过DDE与“组态王”开发的人机界面进行数据交换，控制算法采用专家决策系统。为此，对系统的硬件配置、上位机应用软件设计进行了较详细地讨论。     

Resistance in the highly DDT-resistant 91-R strain of Drosophila melanogaster involves decreased penetration,increased metabolism,and direct excretion

Resistance to 4,4′-dichlorodiphenyltrichloroethane (DDT) in the 91-R strain of Drosophila melanogaster is extremely high compared to the susceptible Canton-S strain (>1500 times). In addition to enhanced oxidative detoxification, the 91-R strain also has a reduced rate of DDT penetration, increased levels of reductive and conjugative metabolism, and substantially more excretion than the Canton-S strain. Contact penetration of DDT was ∼30% less with 91-R flies, which also had significantly more cuticular hydrocarbons and a thicker, more laminated cuticle compared to Canton-S flies, possibly resulting in penetration differences. DDT was metabolized ∼1.6-fold more extensively by 91-R than Canton-S flies, resulting in dichlorodiphenyldichloroethane (DDD), two unidentified metabolites and polar conjugates being formed in significantly greater amounts. 91-R flies also excreted ∼4-fold more DDT and metabolites than Canton-S flies. Verapamil pretreatment reduced the LD₅₀ value for 91-R flies topically dosed with DDT by a factor of 10-fold, indicating that the increased excretion may involve, in part, ATP-binding cassette (ABC) transporters. In summary, DDT resistance in 91-R is polyfactorial and includes reduced penetration, increased detoxification and direct excretion.     

一种现代大型农业温室控制系统的设计与实现

现有的农业大型温室系统种类繁多,但绝大部分未能综合应用自动化的新技术。提出了一种现代大型农业温室大棚控制系统的设计与实现方法,分析了系统的基本原理,介绍了该系统中应用的FCS、DDE和组态软件关键技术,阐述了其实现的具体方法,并给出了软件流程图和运行效果图。最后,对该系统在实际工程中的应用作出了评价。