肯尼亚退化红树林港湾悬浮泥沙交换和输移动力机制

本文主要研究了肯尼亚姆瓦彻湾(属于浅潮滩红树林湿地)泥沙交换的动力机制.该港湾属于半日潮,大、小潮的潮差分别为.2m和1.4m,大潮高水位的水面面积为17km2.     

“We can keep the fire burning”: building action competence through environmental justice education in Uganda and Germany

The global dimensions of climate change necessitate a response that takes national differences – social, economic, geographic, and cultural – into account. Action-oriented education has a key role to play in advancing citizen engagement in a culture of sustainability. This paper describes research conducted with one such education programme, Youth Leading Environmental Change (YLEC), which operates in six countries and engages university-aged youth in discussion and practice related to global sustainability, systems thinking, and environmental justice. YLEC aims to advance four key competencies; this paper focuses on the goal of action competence, which involves acquiring knowledge, reflecting on experience in the context of one’s values, envisioning alternative futures, and acting individually and collectively to advance those alternatives. The present article examines the impacts of YLEC on environmental action competence in two of the countries involved in this research: Uganda and Germany. In-depth interviews were conducted with participants in both countries to examine the development of action competence during and after the programme. Findings suggest that outcomes differed in each country, reflective of participants’ different lived experiences. YLEC effectively built on the conditions faced in each country to accompany youth to a higher level of awareness and action. These findings have implications for environmental education programmes striving to work with multiple nations and diverse participants.     

Effect of colloid-size copper-based pesticides and wood-preservatives against microbial activities of Gram-positive Bacillus species using five-day biochemical oxygen demand test

Copper-based pesticides and wood preservatives could end up in the environment during production, use, and end-of-life via different pathways that could cause unintended ecological and adverse health effects. This paper provides the effect of colloid-size Cu-based pesticides (CuPRO and Kocide), micronized Cu azole (MCA-1 and MCA-2) and alkaline Cu quaternary (ACQ) treated woods, Cu²⁺, Cu²⁺ spiked untreated wood (UTW), and CuCO₃ solutions against Gram-positive Bacillus species using five-day biochemical oxygen demand (BOD₅) standard test. The total Cu leached from MCA-1, MCA-2, and ACQ in Milli-Q water after 5 days were ~0.1, ~0.11, and ~0.64 g/kg of wood, respectively. However, the form of Cu leached from MCA woods was mostly ionic (> 90%). The total organic carbon (TOC) content of any tested wood (UTW/MCA-1/MCA-2/ACQ) was ~99% of its corresponding total carbon (TC) content, whereas the TOC of any tested wood sawdust exceeded that of its corresponding piece/block by > 300%. The dissolved oxygen (DO) consumption value in the presence of Cu²⁺, CuCO₃, CuPRO, and Kocide solutions was significantly influenced by Cu particles/ions. However, the DO consumption value in the presence of UTW/MCA-1/MCA-2/ACQ woods was significantly influenced by organics leached from woods. On the other hand, the DO consumption of MCA sawdust was greater than (300%) that of MCA pieces/block. The findings of this study provide more insight into how organics leached from woods significantly reduce the toxic effects of Cu ions against Gram-positive Bacillus species.     

Maternal serum thyroid antibodies in early pregnancy and fetal Down's syndrome

Thyroid antibodies were measured in mid-trimester antenatal serum samples from 77 pregnancies affected by fetal Down's syndrome and 385 unaffected control pregnancies. Using a haemagglutination technique, thyroglobulin antibodies were detected in 5·2 per cent of cases (4) and 2·9 per cent of controls (11), and thyroid microsomal antibodies were detected in 22 per cent (17) and 15 per cent (59), respectively. Using an enzyme-linked immunosorbent assay (ELISA) for thyroglobulin antibodies and a cut-off level of 50 KIU/1, positive results were found in 25 per cent of cases (19) and 22 per cent of controls (84). Using an ELISA for thyroid microsomal antibodies and the same cut-off level, the proportions were 52 per cent (40) and 39 per cent (149), respectively. While not statistically significant, the differences were consistent with the previously reported increased levels of thyroid antibody found in nonpregnant women who had had pregnancies associated with Down's syndrome.     

山地:自上而下的变化

山地不仅为全球60多亿人口提供了必需的生境和包括水资源在内的各种资源,而且可以使我们深入地了解全球人类的生境是如何发展的、全球气候发生变化时它又是如何响应的、以及气候突变是如何引起全球生物退化和经济衰退等这样的环境问题.在全世界60多亿人口中,至少有6亿人生活在山区.山区同时又是世界上哺育其他数十亿人口的主要河流的发源地.在河谷流域中,至少有一半人的生活用水部分或者全部依赖于山区的冰雪融水.由于人类活动致使大气组成成分发生变化,引起全球气候不断变暖,从而导致冰川的不断退缩.许多冰川已经或正在消失,这将严重威胁全球城市用水需求.全球温度升高在高纬地区表现得最为明显,从而使得像格陵兰和南极大陆的一些大冰盖变得非常脆弱.北半球冰川的剧烈消融又产生了许多其他的问题:如挪威海湾流的减弱,斯堪的纳维亚半岛和北欧气候的大规模变化等.在生物海洋中,山地是一些生物岛,特有的物种生态型很多.全球气候变暖,使环境的变化已超出了这些山地物种特有生态型的适应范围,致使这些物种特有生态型不能适应环境的改变而对所有类型的病害都很脆弱.这一过程是系统性的衰退,在越来越多暴露于极端气候条件下的山坡上表现得非常明显.现在我们注意到,随着气候变化的累积,植物的死亡率与发病率也不断增加.山区尤其清楚地反映出全球气候突变的严重性.尽管目前的美国政府对一些建设性的建议和措施持强硬立场,但我们还是能够而且必须对此做出应对.     

Changes in functional structure of soil bacterial communities due to fungicide and insecticide applications in canola

The fungicide vinclozolin and insecticide λ-cyhalothrin are widely used to control canola (Brassica spp.) diseases and insect pests, respectively, in Canada. We investigated non-target effects of these pesticides, applied at recommended rates, on soil microbial biomass, functional bacterial diversity and functional community structure of soil bacteria (by evaluating patterns of C substrate utilization) in canola rhizosphere and bulk soil at three locations in Alberta from 2002 to 2004. Experimental treatments were (a) untreated control, (b) vinclozolin fungicide foliar application, (c) λ-cyhalothrin insecticide foliar application, and (d) vinclozolin and λ-cyhalothrin applications. No significant pesticide effects on soil microbial biomass or functional bacterial diversity were observed, but the functional structures of soil bacteria were altered. In 1 of 12 cases, the control treatment had a different soil bacterial community structure from the 3 pesticide treatments. The fungicide treatment had different bacterial community structures from the control or insecticide treatments in 3 of 12 cases, the insecticide treatment had different community structures from the control or fungicide treatments in 4 of 12 cases, and the combined fungicide and insecticide treatment had different community structures from the other treatments in 3 of 12 cases. Therefore, evaluating soil bacterial functional structures revealed pesticide effects that were not detected when bacterial diversity or microbial biomass were measured in canola rhizosphere or bulk soil.