CA-125 as a maternal serum marker for Down's syndrome in the first and second trimesters

CA-125, alpha-fetoprotein (AFP), and human chorionic gonadotropin (HCG) were determined in maternal serum in the first trimester from 14 women with a Down's syndrome fetus and 61 women with a healthy fetus. In the second trimester, 15 and 60 serum samples were determined from women with a Down's syndrome and a healthy fetus respectively. In both trimesters, maternal serum CA-125 was found to be elevated in Down's syndrome pregnancies compared with controls. Using discrimination functions, our preliminary results indicate that CA-125 is a better marker than AFP and HCG respectively for a Down's syndrome fetus in the first trimester and improves the detection rate in the second trimester.     

Age of licensure and monitoring teenagers' driving: survey of parents of novice teenage drivers

OBJECTIVE: To assess parental decision making regarding the timing of teenagers initiating driving and monitoring teenagers' driving after licensure. METHODS: About 300 parents were interviewed during spring 2006 in Minnesota, North Carolina, and Rhode Island, states with varying licensing provisions, while teenagers took their first on-road driving tests. RESULTS: States' differences in ages of obtaining learner's permits and licenses reflected different licensing laws, but most teenagers obtained permits and took road tests within the first few months after they became eligible. Common reasons for delaying obtaining permits were fulfilling driver education requirements and lack of readiness/immaturity. Insufficient practice driving most often delayed licensure. Among the parents interviewed, 33-49% believed the minimum licensure age should be 17 or older. Almost all parents planned to supervise teenagers' driving after licensure, and most wanted to know about speeding or distractions. When asked about in-vehicle devices to monitor teenagers' driving, 37-59% of parents had heard of them. Parents were least interested in using video cameras and about equally interested in computer chips and cell-phone-based GPS systems. Disinterest in monitoring devices most often was attributed to trusting teenagers or respecting their privacy. CONCLUSIONS: Licensing laws influence ages of initiating driving. Although many parents support licensing at 17 or older - higher than in all but one state - most teenagers initiate driving soon after reaching the minimum age. Parents plan to supervise teenagers' driving, and many say they are open to using in-vehicle monitoring devices. IMPACT ON INDUSTRY: Many parents support a minimum licensing age of 17 or older and would consider in-vehicle devices to extend their supervision of teenager's driving.     

海洋环境水下采油树腐蚀与防护研究进展

根据国内外水下采油树腐蚀防护技术现状,从采油树腐蚀环境、材料选择、阴极保护及涂层防护方面系统地探究了水下采油树的腐蚀防护技术,对各种技术的优缺点进行了比较分析.材料选择方面,主要对采油树的服役环境、服役要求及材料性能等进行了探究,并对常见水下采油树的材料316L、25Cr7Ni4Mo型双相不锈钢、30CrMo钢及Inc...     

Root-associated (rhizosphere and endosphere) microbiomes of the Miscanthus sinensis and their response to the heavy metal contamination

The plant root-associated microbiomes, including both the rhizosphere and the root endosphere microbial community, are considered as a critical extension of the plant genome. Comparing to the well-studied rhizosphere microbiome, the understanding of the root endophytic microbiome is still in its infancy. Miscanthus sinensis is a pioneering plant that could thrive on metal contaminated lands and holds the potential for phytoremediation applications. Characterizing its root-associated microbiome, especially the root endophytic microbiome, could provide pivotal knowledge for phytoremediation of mine tailings. In the current study, M. sinensis residing in two Pb/Zn tailings and one uncontaminated site were collected. The results demonstrated that the metal contaminant fractions exposed strong impacts on the microbial community structures. Their influences on the microbial community, however, gradually decreases from the bulk soil through the rhizosphere soil and finally to the endosphere, which resulting in distinct root endophytic microbial community structures compared to both the bulk and rhizosphere soil. Diverse members affiliated with the order Rhizobiales was identified as the core microbiome residing in the root of M. sinensis. In addition, enrichment of plant-growth promoting functions within the root endosphere were predicted, suggesting the root endophytes may provide critical services to the host plant. The current study provides new insights into taxonomy and potential functions of the root-associated microbiomes of the pioneer plant, M. sinensis, which may facilitate future phytoremediation practices.     

黄土高原关键带土壤水分空间分异特征

地球关键带是人类生存和发展的关键区域。关键带发生的一系列物理、化学和生物过程与人类活动密切相关。土壤水分是黄土高原关键带的关键要素,同时又是黄土高原植被恢复与生态环境重建的决定因子。为揭示黄土高原关键带土壤水分的空间分异特征,采用网格(50m×50m)布点,雨季结束后采集0~500cm深度土壤样品,结合室内分析,结果表明:黄土高原小流域中73个样点0~500cm的土壤含水量分布范围介于1%~23%之间,降水对0~100cm土层的土壤水分补充明显;土壤水分在水平和垂直方向都表现出明显的空间异质性,在不同方向上的水分控制过程有所不同,是对土地利用方式、植被类型、地形要素、土壤质地等多因素综合响应的结果。充分理解关键带土壤水分空间的分异规律及其主控因素有助于该区小流域综合治理中的植被建造与布局,也有助于对该区土壤水文和生物地球化学过程的理解。     

电子部组件延寿分析

由于军用电子设备的高可靠性以及列装之前的测试无法完全模拟出真实的服役环境,导致测试结果的参考意义不大。鉴于此,文中将以电子部组件的任务剖面作为基础,在制作环境载荷谱时,参考影响电子部组件寿命的关键因素,将电子元器件及焊点疲劳失效的机理模型作为理论依据。在绘制电子部组件的CAD模型时,进行适当简化,使用ANSYS软件对其进行多载荷耦合作用下的有限元仿真,找出电子元器件的薄弱点,并对关键部位进行寿命预测,为军用电子设备故障的初步诊断及装备延寿分析提供借鉴。     

Concentrations of polychlorinated dibenzo‐p‐dioxins and dibenzofurans in outdoor air of North‐Rhine‐Westphalia,Germany

Measurements of polychlorinated dibenzo‐p‐dioxins (PCDD) and dibenzofurans (PCDF) in outdoor air of North‐Rhine‐Westphalia were carried out. Fifty‐six samples were taken at different sites in areas of different land use and emission structures. A special filter system allowed analysis of the gas and particle phases separately. It was found that higher chlorinated PCDD/PCDF (7 or 8 chlorine atoms) are collected on glass fiber filter and lower chlorinated PCDD/PCDF (tetra‐ and penta‐CDD/CDF) are absorbed on polyurethane foam. The following isomers were determined: OCDD, OCDF and 11 isomers with chlorine substitution in 2,3,7,8‐position as well as the sum of TCDD, PeCDD, HxCDD, HpCDD, TCDF, PeCDF, HxCDF, HpCDF and the sum of PCDD (4–8) and PCDF (4–8). No 2,3,7,8‐TCDD could be detected but 2,3,7,8‐TCDF was found at 15 sites. Mean concentration in the Rhine‐Ruhr‐District for the sum of PCDD (4–8) and PCDF (4–8) was 3.2pg/m³ and 5.5pg/m³ respectively. Detection limit for TCDD and PCDD/PCDF (5–8) was 0.1–0.2 pg/m³ and 0.005–0.015 pg/m³ respectively. There is no significant indication that 2,3,7,8‐chlorinated isomers of PCDD/PCDF are predominantly decomposed by photochemical reactions in outdoor air.     

Environmental fate of pesticides used in Australian viticulture V. Behaviour of atrazine in the soils of the south Australian Riverland

The transport of the s‐triazine herbicide, atrazine, through the red, calcareous earth soils of the South Australian Riverland was investigated. Small, undisturbed soil cores were extracted from the inter‐row topsoil of a vineyard adjacent to the River Murray, approximately 10 km south‐west of Overland Corner, South Australia. The vines were grown in a deep (1–4 m) reddish brown, strongly alkaline, sandy loam with a low organic carbon content (<2%). Atrazine concentrations in the leachate were dependent on application rate and soil type. High application rates on subsoil gave high rates of leaching for a longer time compared to the same application rate on topsoil and/or lower application rates on either topsoil or subsoil. Overall, 37–65% of the applied atrazine was detected in the leachate from subsoil cores, 14–25% in topsoil core leachates. Small amounts of atrazine (< 10% of applied dose) were found only in the top 2 cm of the core profiles. The results suggest that this herbicide is somewhat mobile in such strongly alkaline, sandy loam soils and that the irrigated soils of this region are likely to be prone to leaching of atrazine, and therefore that groundwater supplies in this area may be at risk of contamination through use of triazine herbicides.     

Valuing eco-assets: A note on valuation methods

SUMMARY

The valuation of eco-assets should take into account the perceptions and judgments of the public. However, the value of eco-assets based on conventional calculations has often been unreliable as a result of differing situations and individuals involved. Therefore, a reasonable and efficient method for valuing eco-assets is needed. In this paper, a brief summary of the history of valuing eco-assets is provided, followed by a summary of conventional methods of valuation. This summary of the currently used methods revealed that they do not take into account the effect of the stage and development of the population determining the value of the eco-assets. Therefore, we have developed a social development stage coefficient (l), based on Engel's coefficient. A new valuation method was then created by integrating the development stage coefficient (l) with a conventional model. Finally, possible future strategies for valuing eco-assets are discussed.     

Multi-objective synthesis of a company's supply network by accounting for several environmental footprints

This contribution presents the multi-objective synthesis of a company's supply network by integrating renewables (biomass and other waste, and solar energy) and accounting for several environmental footprints. The synthesis is based on a Mixed-Integer Linear Programming (MILP) problem. A previously developed model by the authors for achieving energy self-sufficiency by integrating renewables into companies’ supply networks has been extended for the evaluation of environmental impacts, such as energy, carbon, nitrogen, and water footprints. The achievement of an energy self-sufficient supply network has been considered whilst significantly reducing environmental impacts.The presented model is applied to multinational poultry-meat producing company. Direct (burdening) and indirect (unburdening) effects that form total effects on the environment are considered for the evaluation of environmental footprints. The results showed significant unburdening of the environment in terms of carbon and nitrogen footprints but, however, higher burdening in terms of the water footprint.