We should not allow dissection of animals

This essay argues against routine dissection exercises on animals under three headings. First, attaining goals of general scientific education does not require dissection. The training of specialists, in whose vocations dissection skills are essential, could then be accomplished without killing animals specifically for the purpose of acquiring those skills. Second, killing and dissecting animals for unnecessary exercises teaches students bad attitudes toward animal life. Third, moral principles cannot justify killing and dissecting animals but not humans; consequently, such treatment of animals is prejudiced exploitation of the weak by the strong.     

恢复力与可持续发展:在瞬息万变的世界中增强适应能力

由于在以往的自然资源政策上逐渐暴露出了两个带根本性的错误,人们开始意识到在环境管理理论和实践方面需要进行一场全球性的重大改革.第一个错误是毫无保留地假定生态系统对人类利用所作出的反应是呈线性关系、是可以预测和控制的.第二个错误是认定人类社会与天然系统可以分别对待,不必联系在一起进行考虑.然而,从世界各地收集到的证据表明,天然系统和人类社会系统是以非线性方式运行的、在其动态运行过程中均有其显著的极限,而且,人类社会与生态系统表现为一种紧密相联的、复杂的且不断演变的综合系统.本文是代表瑞典政府环境咨询委员会编写的一份报告的摘要,这份报告是作为向2002年8月26日～9月4日在南非约翰内斯堡召开的可持续发展世界首脑会议献礼的论文而撰写的.从概念上说,恢复力是一种能缓冲变化所带来的影响、学习知识和求得发展的能力,我们将它作为在一个纷纭复杂、快速变化的世界中,是否真正懂得如何维护和提高适应能力的一种参照标准来使用.在社会、生态综合系统中,有两种有用的工具可用来提高恢复力,一种是结构严谨的工作方案,另一种是积极的适应力管理.这两种工具都需要而且有助于形成这样一种社会环境:具有灵活开放的组织机构和多层次的监管体制,允许学习适应力方面的知识和提高适应力但又不妨碍对未来的发展作出选择.     

Laboratory-scale comparison of anaerobic-digestion alternatives.

Laboratory-scale digesters were used to perform side-by-side evaluations of alternative digestion systems including thermophilic-mesophilic-phased digestion (TPAD), acid/methane-phased digestion, mesophilic digestion, and the performance of the thermophilic stage of TPAD alone. Total detention times in the systems evaluated varied from 8 to 20 days. Temperatures in the mesophilic stage of TPAD were varied from 35 to 43.3 degrees C and temperatures in the thermophilic stage were varied from 55 to 58.9 degrees C. The purpose of the study was to evaluate volatile solids (VS) reduction and thickening properties of the different systems. Parameters evaluated included solids, volatile acids, gas production and quality, various chemical constituents of the sludge, and thickening properties using polymer and ferric chloride plus polymer. The TPAD systems were found capable of higher VS destruction at total detention times of 10 and 12.5 days compared to single-stage mesophilic or thermophilic digestion at 15 to 20 days. A laboratory-scale thickening test was performed to evaluate thickening properties. Based on obtaining 95% capture in the test, the polymer demand of mesophilic and acid-methane-phased digestion was the lowest. The TPAD system required approximately 180% of the dosage of the mesophilic sludge and thermophilic sludge required approximately 310% of the dosage. Temperatures of 40.5 and 43.3 degrees C in the mesophilic stage of TPAD were found to increase the polymer requirement and decrease the VS reduction of the TPAD system. Higher temperatures (above 56.1 degrees C) and lower detention times (less than 15 days) in the thermophilic digesters seemed to result in problems with degradation of volatile acids, particularly propionic acid.     

Evaluation of approaches for terrestrial hazard classification

Hazard assessment is an essential element in the evaluation of the potential effects of chemical substances on the environment. To date, most work has focused on hazard assessment schemes for the aquatic environment, but in recent years, a number of proposals have been developed for other environmental compartments. Due to limited datasets, the suitability of the toxicity cut-off values in these schemes has not been fully determined and the practicalities associated with using these approaches have not been fully established. This study, which focused on the soil compartment, was performed to examine cut-off values proposed by two terrestrial hazard assessment schemes and establish the availability of data. Data on earthworms indicated that current proposals for toxicity cut-off values are appropriate. However, analysis of IUCLID (International Uniform ChemicaL Information Database) indicates that even for commonly used high production volume chemicals, insufficient data are available to enable classification. Whilst the necessary data may already be available for selected groups of substances (e.g. pesticides and veterinary medicines), a significant experimental testing programme would therefore be required before a terrestrial classification system could be applied widely. Such data may become available in the future as a result of initiatives such as REACH.     

Temperature cues gametogenesis and larval release in a tropical sponge

Determining the reproductive processes of benthic invertebrates is central to our understanding of their recruitment and population dynamics. Sexual reproduction of the gonochoric and viviparous Great Barrier Reef sponge, Luffariella variabilis (Poléjaeff 1884) was quantified from histological samples collected over two reproductive seasons (2004 and 2005). Gametogenesis commenced for females at a water temperature of 21°C, the lowest water temperature of the year. Spermatogenesis occurred above 22.5°C with sperm asynchronously developed and released from August or September to October. Oocytes developed asynchronously from July to September, embryos from September to December, and larvae from November to December. Female reproduction terminated in December (after larval release) prior to the highest mean annual water temperature of 30°C in January. There was a significant (35%) decrease in female reproductive output in 2005 compared to 2004, as measured by the reproductive index (0.68 ± 0.12 female reproductive propagules mm⁻² of mesohyl in 2005 compared with 1.05 ± 0.10 mm⁻² in 2004). This corresponded with delayed oogenesis and spermatogenesis, and a shortened larval development cycle corresponding with a delayed minimum temperature (21°C) in August of 2005 compared with July 2004. Accordingly, the maximum percentage of the mesohyl occupied by female reproductive propagules (eggs, embryos and larvae) was also reduced by 60% in 2005 (overall mean of 13.04% in October 2004 compared with 5.35% in October 2005). However, the mean sizes of individual female propagules remained the same from year to year. Males in contrast, showed no overall difference in either reproductive index or percentage occupation of the mesohyl between 2004 and 2005. The lowered reproductive output (∼35%) of females of L. variabilis associated with delayed minimum water temperatures may have important implications for population reproductive success where oogenesis and spermatogenesis and larval release are cued by minimum and maximum water temperatures, respectively.     

量化沿海海域中背景营养盐的富集:波罗的海城市港湾的实例研究

对受到破坏的海岸生态系统进行成功的管理需要它们过去状况的可靠的科学根据.我们证明,生物指标的沉积物记录可用于在监测记录所经历的较短时间跨度之前对营养盐的浓度进行定量重建.我们为总溶解氮建立了一个具有0.09g/L(对数log10的单位)预测精度的借助于硅藻的、加权平均的、部分最小二乘传递函数模型.该模型被用于处理采自拉亚拉赫蒂(Laajalahti)湾的沉积岩心数据,拉亚拉赫蒂湾是位于芬兰赫尔辛基的一个城市港湾,在该港湾中,该模型的性能在30年的水质数据记录和该流域中已知土地使用变化的基础上得以证实.尽管该模型低估了受到严重影响的该港湾中的高营养盐浓度,但它仍成功跟踪了该营养盐记录中的各种趋势.实际值与预测值之间存在的总体一致性显示出该方法在对沿海水域中的背景营养盐浓度进行评估方面具有的巨大潜力.     

Toxicity and Mutagenicity of Component Classes of Oils Isolated from Soils at Petroleum- and Creosote-Contaminated Sites

Abstract

Microtox and Ames bioassays were employed to assess acute toxicity and mutagenicity of water soluble components of class–fractionated oils extracted from one creosote–and four petroleum–contaminated soils. Microtox results revealed that potential acute toxicity resides mainly in the polar class fractions at three sites and indicated potential synergistic and antagonistic effects between compounds in the total extracts at two sites. Ames Salmonella/microsome testing indicated that the polyaromatic fractions at two sites exhibit weak mutagenicity with enzymatic activation, while the polar fractions at two sites are weakly mutagenic without enzyme activation. Further chemical characterization of the polar and polyaromatic fractions is required to fully assess the potential of health and ecological risks at the creosote–and petroleum–contaminated sites exhibiting these toxic responses.