Forensic Evaluation of Metals (Cr,Cu, Pb,Zn), Isotopes (δ13C and δ15N), and C:N Ratios in Freshwater Sediment

A forensic approach was used to evaluate sediments from Portão Stream, including analysis of metals, carbon (C) and nitrogen (N) stable isotopes, and C:N ratios. Samples collected at various points located along the stream were tested in order to investigate a possible illegal leachate input. The studied stream is heavily impacted by sewage and industrial discharges from two cities along its course. Among the metals analyzed, chromium (Cr) was noticeably the main pollutant, showing the highest levels, above regulatory limits, downstream from some potential sources of effluents enriched with this metal. Isotope analyses revealed a general trend of depletion in the heavier isotope along the stream for C and N. The exception was one point near a hazardous waste landfill, where relatively more enriched δ¹³C and δ¹⁵N values were found. The isotope and metal analysis results indicated that this site was affected by a particular source, demonstrating the combination of these parameters could be used for the discrimination of sources in a heavily polluted stream. Nevertheless, further investigations are necessary to provide a comprehensive evaluation of the biogeochemical processes involved in the incorporation of leachate in sediments to use this analysis as evidence for the illegal leachate discharge.     

Activity of biotin-dependent and gaba metabolizing enzymes in chorionic villus samples: Potential for 1st trimester prenatal diagnosis

We have documented the presence of five mitochondrial enzymes in samples of chorionic villus tissue and measured the levels of activity. Three of the enzymes catalyse biotindependent reactions. These are propionyl-CoA carboxylase, 3-methylcrotonyl-CoA carboxylase and pyruvate carboxylase. the other enzymes. 4-aminobutyric acid aminotransferase and succinic semialdehyde dehydrogenase, are involved inthe degradation of the central inhibitory neurotransmitter GABA. Distinct diseases in whichthere is deficiency of each of these enzymes have been documented in man. Significant levels of activity were observed for all five enzymes in chorionic villus tissue. This methodology should permit early prenatal diagnosis of deficiencies of these enzymes by chorionic villus biopsy in the first trimester.     

Improved speciation of dissolved organic nitrogen in natural waters: amide hydrolysis with fluorescence derivatization

The objective of this study was to improve primary-amine nitrogen (1°-N) quantification in dissolved organic matter (DOM) originating from natural waters where inorganic forms of N, which may cause analytical interference, are commonly encountered. Efforts were targeted at elucidating organic-N structural criteria influencing the response of organic amines to known colorimetric and fluorescent reagents and exploring the use of divalent metal-assisted amide hydrolysis in combination with fluorescence analyse...     

消融的冰川：加拿大班夫国家公园亚高山带鲍湖中持久性有机氯的主要来源

有机氯杀虫剂和多氯联苯（PCB）是环境中普遍而稳固的化合物。现已查明，由于它们从温暖的地区逐渐蒸发出来，并在较冷的地区凝聚下来，因而它们富集在寒冷的环境中。在本研究中，我们的结果是，消融的冰川供给阿尔伯达亚高山带湖泊中的有机氯输入量为50%～97％，而提供的水量为73％。对氚的分析结果表明，在夏季的中、晚期，至少10％的冰川消融物是在1950～1970年期间沉积下来的，这期间它受到有机氯更多的污染。这一发现表明，气候变暖可能会使消融的冰川成为日益增多的淡水污染物来源。由于有机物贫乏的冰川粘土对多氯联苯这样的疏水化合物的吸附能力有限，因此冰川水流带来的有机氯大多呈溶解状态。     

Brazil's Electric Power Choices and Their Corresponding Carbon Emissions Implications

This study analyzes the options for meeting power demand in the Brazilianpower sector through the year 2015. Three policy cases are constructedto test economic and environmental policy measures against a baseline:advanced technologies scenario, environmental control scenario and carbon(C) elimination scenario. Least-cost modeling simulated these scenarios throughchanges in emissions fees and caps, costs for advanced technologies,demand side efficiency, and clean energy supplies. Results show that, in theabsence of alternative policies, new additions to Brazil's electric powersector will shift rapidly from hydroelectricity to combined-cycle natural gasplants. When the cost of environmental impacts are incorporated in theprice of power, the least-cost mix of electric power generation technologycould change in other ways. In all scenarios, energy efficiency andcogeneration play an important role in the least-cost power solution. Savingelectricity through increased efficiency offsets the needs for new supply andhas enormous potential in Brazil's industrial sector. Efficiency also reducesthe environmental burden associated with electricity production andtransmission, without compromising the quality of the services demandedby end users. Interesting enough, carbon dioxide (CO₂) emissions will remainrelatively low under almost every conceivable scenario.     

Partition of polycyclic aromatic hydrocarbons on organobentonites from water

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｌｕｍｉｎｏｓｉｌｉｃａｔｅｓｈｅｅｔｓｏｆｂｅｎｔｏｎｉｔｅｐｏｓｓｅｓｓａｎｅｔｎｅｇａｔｉｖｅｅｌｅｃｔｒｉｃａｌｃｈａｒｇｅｃｏｍｐｅｎｓａｔｅｄｆｏｒｂｙｉｎｏｒｇａｎｉｃｅｘｃｈａｎｇｅａｂｌｅｃａｔｉｏｎｓ(ｅ.ｇ.,Ｎａ+ａｎｄＣａ2+),ｗｈｉｃｈｓｔｒｏｎｇｌｙｈｙｄｒａｔｅｄｉｎｔｈｅｐｒｅｓｅｎｃｅｏｆｗａｔｅｒ.Ｓｕｒｆａｃｅｐｒｏｐｅｒｔｉｅｓｏｆｎａｔｕｒａｌｂｅｎｔｏｎｉｔｅｃａｎｂｅｍｏｄｉｆｉｅｄｂｙｓｉｍｐｌｅｉｏｎｅｘｃｈａｎｇｅｗｉ…     

Distribution of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area in China

ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｒａｚｉｎｅ(2ｃｈｌｏｒｏ4ｅｔｈｙｌａｍｉｎｏ6ｉｓｏｐｒｏｐｙｌａｍｉｎｏｓｔｒｉａｚｉｎｅ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｓｅｌｅｃｔｉｖｅｐｒｅａｎｄｐｏｓｔｅｍｅｒｇｅｎｃｅｈｅｒｂｉｃｉｄｅｓｆｏｒｔｈｅｃｏｎｔｒｏｌｏｆｂｒｏａｄｌｅａｆａｎｄｇｒａｓｓｙｗｅｅｄｓ.ＴｈｉｓｈｅｒｂｉｃｉｄｅｉｓｐｒｉｍａｒｉｌｙｕｓｅｄｉｎｃｏｒｎｃｒｏｐｐｉｎｇｓｙｓｔｅｍｉｎＮｏｒｔｈｅａｓｔａｎｄＮｏｒｔｈｏｆＣｈｉｎａ,ａｎｄａｓｏｆｔｅｎｔｉｍ…     

Design of policy mechanism to promote cleaner production in China

ＩｎｔｒｏｄｕｃｔｉｏｎＣｌｅａｎｅｒｐｒｏｄｕｃｔｉｏｎ (ＣＰ)ｈｏｌｄｓｇｒｅａｔｐｒｏｍｉｓｅａｓａｎｅｆｆｅｃｔｉｖｅｓｔｒａｔｅｇｙｉｎｔｈｅｆａｃｅｏｆｄｏｕｂｌｅｃｈａｌｌｅｎｇｅｓｏｆｅｎｖｉｒｏｎｍｅｎｔａｌｐｒｏｔｅｃｔｉｏｎａｎｄｅｃｏｎｏｍｉｃｄｅｖｅｌｏｐｍｅｎｔ.Ｉｎ 1993,ａｄｅｍｏｎｓｔｒａｔｉｏｎｐｒｏｊｅｃｔ (Ｂ 4ｐｒｏｊｅｃｔ) ,ｄｅｓｉｇｎｅｄａｎｄｅｘｅｃｕｔｅｄｂｙｔｈｅＳｔａｔｅＥｎｖｉｒｏｎｍｅｎｔａｌＰｒｏｔｅｃｔｉｏｎＡｄｍｉｎｉｓｔｒａｔｉｏｎ (…