Free ‐ living animals as indicators of environmental pollution by chlorinated hydrocarbons

As some species of game and free‐living animals promptly respond to ecosystem damage by a reaction that is easy to interpret, they are important ecological indicators in assessing the total contamination of the environment. Consumers of the highest order like predators, predatory and fish‐eating birds are among the most important bioindicators of environmental contamination by chlorinated hydrocarbons and PCB.

Data on chlorinated hydrocarbons and PCB levels were collected throughout 1988–1992 and obtained from 16 species of free‐living animals from 9 protected areas of Slovakia. Muscle tissue, liver, kidney and egg samples were examined for HCB, HCH isomers, DDT and its analogues, and PCB.

Levels of organic chlorinated contaminants reveal a decreasing tendency and thus cease to be a toxicologically important risk factor in game, with the exception of predatory birds, as significant values have been recorded in their eggs and reproductive organs.     

我国西南湖塘溪流的水化学组成与离子平衡的研究

本文研究了我国重酸雨地区四川，贵州省湖塘溪流的水化学组成及离子平衡关系，结果表明：城郊之间水化学组成存在差异；同时，进行离子平衡衡算时，须对溶解态钙，镁进行校正，否则，会出现阴离子短缺现象，仅由钙，镁及硫酸根和弱酸根组成的简单离子平衡也是大致符合的，但其应用有一定的局限性。     

ADVANCES IN THE BOUNDARY INTEGRAL EQUATION METHOD IN SUBSURFACE FLOW1

ABSTRACT: This paper explores some of the advances of the boundary element method, as applied to ground-water problems, during the last five years. Although the method is still somewhat limited compared to solution by finite elements, the range of solutions has increased considerably. Diffusion and advection-diffusion solutions are done efficiently. These include the incorporation of inhomogeneity, anisotropy, and nonlinear diffusion. The difficult problem of stream-aquifer interaction is an important application as it is much easier to follow a free surface with its multiple configurations. The application must be able to cycle between ground-water connection and disconnection with the stream and include seepage surfaces. Flow in fractured media is a natural application where the flow in fractures can usually be treated without a computational exception in spite of extremely high aspect ratios. The case of seawater intrusion forms a type of free surface problem and thus is a case for which the method has special advantages. For these and other applications the boundary element method provides an inexpensive technique for calculation where the data preparation and setup time is minimal. In most of these cases, programs can and have been written on microcomputers.     

Dams and Flows: Immersing in Western Meaning Systems in Search of Ecocultural Reflexivity

In this unprecedented era of anthropogenic ecological destruction, this study illustrates inadequacies in conceptual language available in Western settings to think deeply and holistically about “nature.” At the same time, the study illustrates transformative potential of moments of ecocultural reflexivity. Using free write methodology, we examine ways participants in the United States, New Zealand, and Australia articulate what they mean when they say “nature.” We interpret participant streams of consciousness as representative of a wider Western river-way, a channel of dominant, multiple, and contradictory meanings in continuous movement. We identify conceptual obstructions that provide glimpses into ways Western ecological relations are bounded and dammed by binary, fragmented, and unconsidered meanings. Yet reflexivity in the face of such obstructions, and in potent ecocultural side streams of childhood remembering and ecocentric cosmology, provides some participants a lucid flow of regenerative narratives at a time such shared stories are urgently needed.     

重庆市无公害蔬菜基地环境和产品质量评价标准初探

通过对重庆市环境污染情况的调查分析 ,结合现行的国家相关环境质量标准和食品卫生标准 ,提出了适合重庆市无公害蔬菜基地建设的环境质量和产品质量评价标准体系 ,为建立规范化、标准化绿色蔬菜基地打下了基础     

N,N-二乙基对苯二胺分光光度法测定饮用水中的游离余氯

文中采用N,N-二乙基对苯二胺分光光度法测定饮用水中的游离余氯,实验结果表明,该方法可以准确测定水中的游离余氯且有好的线性,相关系数大于99%。方法检测限为0.01 mg/L,相对标准偏差为2.47～9.08%,回收率在92.5～105%之间,检测方法符合《生活饮用水卫生标准》(GB 5749-2006)的要求。     

丙烷扩散火焰燃烧光谱特性研究

为实现烃类火灾事故的光谱辨识,对丙烷火焰燃烧初期过程中的光谱特性进行实验研究,利用拉曼光谱仪等设备采集、提取丙烷扩散火焰光谱数据。分析燃烧初期OH~*,C₂~*,CH~*,H₂O分子谱带范围及特征峰值分布特性,揭示谱带光谱特征强弱的主要原因,阐述沿火焰轴向与径向C₂~*,CH~*以及H₂O分子光谱峰值强度的分布特性。研究结果表明：丙烷火焰特征光谱主要分布在可见光与近红外波段,250～380 nm的近紫外波段光谱强度较弱。C₂~*的509.4,512.8,810.5 nm特征谱带,CH~*的431.4 nm谱带以及H₂O分子的586.2,652.2 nm处振动-转动谱带可作为丙烷火焰燃烧的关键特征光谱,为烃类火灾的早期识别与防控提供光谱实验依据。     

Prenatal detection of free sialic acid storage disease: genetic and biochemical studies in nine families

Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease-causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd.     

Maternal serum levels of dimeric inhibin A in pregnancies affected by trisomy 21 in the first trimester

Dimeric inhibin A was measured in maternal serum samples from 45 pregnancies affected by trisomy 21 and 493 samples from unaffected pregnancies at 10–14 weeks of gestation. Inhibin A levels in affected pregnancies were compared with levels of free β-hCG and PAPP-A in the same series. In the trisomy 21 group, the median multiple of the median (MoM) inhibin A was not significantly elevated (1.28 vs 1.00) with only 15.5% being above the 95th centile. In contrast, the median MoM free β-hCG was significantly increased (2.05 vs 1.00) with 36% above the 95th centile and PAPP-A was significantly reduced (0.49 vs 1.00) with 42% below the 5th centile. Inhibin A levels in the trisomy 21 group were significantly correlated with gestational age such that median levels rose from 1.04 at 11 weeks to 1.30 at 12 weeks and 1.67 at 13 weeks. These findings suggest that first trimester biochemical screening for trisomy 21, which is currently optimised using maternal serum free β-hCG and PAPP-A and fetal nuchal translucency, will not benefit from the inclusion of inhibin A. Copyright © 2001 John Wiley & Sons, Ltd.