Unexpected removal of the most neutral cationic pharmaceutical in river waters

Contamination of surface waters by pharmaceuticals is now widespread. There are few data on their environmental behaviour, particularly for those which are cationic at typical surface water pH. As the external surfaces of bacterio-plankton cells are hydrophilic with a net negative charge, it was anticipated that bacterio-plankton in surface-waters would preferentially remove the most extensively-ionised cation at a given pH. To test this hypothesis, the persistence of four, widely-used, cationic pharmaceuticals, chloroquine, quinine, fluphenazine and levamisole, was assessed in batch microcosms, comprising water and bacterio-plankton, to which pharmaceuticals were added and incubated for 21 days. Results show that levamisole concentrations decreased by 19 % in microcosms containing bacterio-plankton, and by 13 % in a parallel microcosm containing tripeptide as a priming agent. In contrast to levamisole, concentrations of quinine, chloroquine and fluphenazine were unchanged over 21 days in microcosms containing bacterio-plankton. At the river-water pH, levamisole is 28 % cationic, while quinine is 91–98 % cationic, chloroquine 99 % cationic and fluphenazine 72–86 % cationic. Thus, the most neutral compound, levamisole, showed greatest removal, contradicting the expected bacterio-plankton preference for ionised molecules. However, levamisole was the most hydrophilic molecule, based on its octanol–water solubility coefficient (K _ow). Overall, the pattern of pharmaceutical behaviour within the incubations did not reflect the relative hydrophilicity of the pharmaceuticals predicted by the octanol–water distribution coefficient, D _ow, suggesting that improved predictive power, with respect to modelling bioaccumulation, may be needed to develop robust environmental risk assessments for cationic pharmaceuticals.     

英国污染减排的经验与启示

论述了英国实现污染物减排环境治理方面的成功经验和做法,其主要有健全完善的法规政策体系,强化运用环境经济手段,建立节能减排的长效机制,建立科学、成熟的战略环评体系(SEA),用最佳可行技术(BAT)防止和减少污染排放,注重公众参与促进全民减排。依据英国实现污染物减排环境治理方面的成功经验和做法,结合目前我国污染物减排工作的实际,对我国污染物减排工作提出了相应的对策与建议。     

Unexpected control of soil carbon turnover by soil carbon concentration

Soils are a key component of the terrestrial carbon cycle as they contain the majority of terrestrial carbon. Soil microorganisms mainly control the accumulation and loss of this carbon. However, traditional concepts of soil carbon stabilisation failed so far to account for environmental and energetic constraints of microorganisms. Here, we demonstrate for the first time that these biological limitations might have the overall control on soil carbon stability. In a long-term experiment, we incubated ¹³C-labelled compost with natural soils at various soil carbon concentrations. Unexpectedly, we found that soil carbon turnover decreased with lower carbon concentration. We developed a conceptual model that explained these observations. In this model, two types of particles were submitted to random walk movement in the soil profile: soil organic matter substrate and microbial decomposers. Soil carbon turnover depended only on the likelihood of a decomposer particle to meet a substrate particle; in consequence, carbon turnover decreased with lower carbon concentration, like observed in the experiment. This conceptual model was able to simulate realistic depth profiles of soil carbon and soil carbon age. Our results, which are simply based on the application of a two-step kinetic, unmystify the stability of soil carbon and suggest that observations like high carbon ages in subsoil, stability of carbon in fallows and priming of soil carbon might be simply explained by the probability to be decomposed.     

Unexpected toxicity decrease during photoelectrochemical degradation of atrazine with NaCl

This report shows an unexpected toxicity decrease during atrazine photoelectrodegradation in the presence of NaCl. Atrazine is a pesticide classified as endocrine disruptor occurring in industrial effluents and agricultural wastewaters. We therefore studied the effects of the degradation method, electrochemical and electrochemical photo-assisted, and of the supporting electrolyte, NaCl and Na₂SO₄, on the residual toxicity of treated atrazine solutions. We also studied the toxicity of treated atrazine solutions using Artemia nauplii. Results show that at initial concentration of 20 mg L⁻¹, atrazine was completely removed in up to 30 min using 10 mA cm⁻² electrolysis in NaCl medium, regardless of the electrochemical method used. The total organic carbon removal by the photo-assisted method was 82% with NaCl and 95% with Na₂SO₄. The solution toxicity increased during sole electrochemical treatment in NaCl, as expected. However, the toxicity unexpectedly decreased using the photo-assisted method. This finding is a major discovery because electrochemical treatment with NaCl usually leads to the formation of toxic chlorine-containing organic degradation by-products.     

Unexpected new species of deep-water Hydroidomedusae from Korsfjorden,Norway

Two new species of Hydroidomedusae, Parateclaia norvegica sp.nov. and Foersteria quadrata sp.nov., are described from specimens collected in Korsfjorden, western Norway. Neither genus has previously been observed in the North-Atlantic Ocean. The closest congenerics to the new species occur in the Mediterranean, where family Teclaiidae has been considered endemic. P. norvegica and F. quadrata were only collected at sites 500 m or deeper and are possibly deep-water benthopelagic species like their congenerics elsewhere. Sampling took place for the entire year 2003 at 2- to 4-week intervals. F. quadrata, the more numerous of the new species, was absent from the water column only during the spring months, the implications of which regarding its lifecycle are discussed. Hypotheses on speciation in the Foersteria species group and family Teclaiidae are shortly discussed.     

生态食品开发的新思路

本文着重介绍了生态农业和生态食品的概念,阐述了生态食品的标志,探讨了生态食品开发的必要性、可行性,并对我国生态食品的开发提出了一些新的思路.     

Unexpected reproductive strategy of Sardinella aurita off the coast of Venezuela

Biological sampling of Spanish sardine (Sardinella aurita Valenciennes, 1847) off the coast of Venezuela from 1956 to 1989 was used to study the reproductive strategy and migration pattern of the population. Whereas in many pelagic fishes the energy re-allocation necessary for reproduction usually occurs optimally at the end of the upwelling season when planktonic production reaches a maximum, in the present study a 5 mo delay was observed. This suggests that energy was stored as lipids early in the season and released later via metabolism for gamete production. Major reproduction did not occur in an area and at a time when offshore transport and turbulence were low, which is also unusual for a pelagic fish species. These results are discussed in terms of the life cycle of the Spanish sardine and its possible migratory patterns. The reproductive strategy of this population apparently gives priority to optimising food availability for the offspring and not to preventing eggs and larvae being transported offshore. The presence of “retention” areas could explain this unexpected strategy. Received: 4 November 1996 / Accepted: 20 December 1996     

城市水循环途径及影响分析

通过对城市水循环途径及人类对自然界水循环影响因素分析，确定城市水资源优先开发、利用次序，提出城市水资源形成良性循环的必要条件。     

中新生态城土壤质量现状及改良利用途径

对中新生态城区域内土壤的紧实度、有机质、碱解氮、土壤盐分、酸碱度、地表水、地下水进行了调查取样分析,结果表明该区土壤容重在1.3～1.7g/cm3,有机质含量大多为中等或低水平（5.5～19.1g/kg）,速效氮与土壤有机质含量相关性达显著水平（r=0.98）。盐分垂直分布上表现为果园、农田土壤盐分含量小于1.5g/kg,荒地和水库含量在5.0～6.4g/kg之间,垫土区、养殖池和盐场盐池土壤通体盐分含量高（大于10g/kg）,且存在表聚现象,超出了一般植物生长的极限。土壤酸碱度为7.81～9.05,水库、养殖池、盐场、荒地、沟塘水的矿化度均在10g/L以上,蓟运河水和农田沟渠为5000mg/L～8500mg/L,果园灌溉水的矿化度也在2000mg/L以上,地下水矿化度高,埋藏浅。并针对以上特点提出其土壤改良利用途径和绿化建设模式。     

论发展高等职业教育的途径

在社会主义市场经济条件下,为什么要大力发展高等职业教育?文章认为,发展高等职业是市场经济发展和科教兴国的客观要求,并通过对高职教育的定位分析,阐明了发展高职教育的重要性.文章从高等教育的特点和“三改一补”的发展途征两方面论述了高职教育的发展方向.     

Unexpected similar stability of soil microbial CO2 respiration in 20-year manured and in unmanured tropical soils

Soil respiration is one of the main CO₂ sources from terrestrial ecosystems. Soil respiration is therefore a major source of greenhouse gas. Knowledge of the impact of agronomic practices such as manuring on the stability, for example resistance and resilience, of heterotrophic C–CO₂ respiration to disturbance is scarce. Here, we studied the stability of soil microbial heterotrophic respiration of two tropical soils from plots annually enriched or not with manure applications during more than 20 years. Stability was quantified after heating soils artificially. We hypothesized that field manuring would change the stability of the microbial community. Additionally, the impact of both manured and unmanured soils to addition of an organic cocktail was assessed under controlled conditions in order to discriminate the metabolic capacity of the microbial community, and to link the metabolic capacity up with the microbial heterotrophic soil respiration. Our results show that total respiration was not significantly different in manured and unmanured pots. Moreover, contrary to our hypothesis, manure amendment did not affect the stability (resistance, resilience) of the microbial abundance or the basal metabolism, in our experimental conditions. By contrast, the diversity of the bacterial community in heated soils was different from that in unheated soils. After heating, surviving microorganisms showed different carbon utilization efficiency, manuring stimulating the growth of different resistant communities, that is, r-strategist or K-strategist. Microbial community of manured soils developed in the presence of the organic cocktail was less resistant to heating than microbial community of unmanured plots.     

关于环境管理方式的几点思考

我国利用经济手段、行政手段治理环境污染存在一定局限 ,从而使各项环保措施难以收到理想效果。文章针对几种环境管理方式的局限性 ,指出开展环境保护工作不能“一刀切” ,也不能对国外流行的方式照搬照抄 ,而是要脚踏实地 ,从现实入手进行环境管理。最后对几种新环境管理方式给予了评价。     

恶臭污染评价分级方法

恶臭污染的定量评价分级是评价恶臭污染状况的重要依据,但目前我国还没有成熟的恶臭污染分级标准.在分析了国外臭气强度标准的基础上,结合韦伯-费希纳公式,计算臭气浓度与臭气强度的对应值,以臭气强度的嗅觉感觉和丰富的实验经验为依据,将恶臭污染程度初步划分为5级,并对分级结果的科学性和合理性进行实验验证.     

Unexpected consequences of vertebrate pest control: predictions from a four-species community model.

Although indirect effects are important structuring forces in ecological communities, they are seldom considered in the design of pest control operations. However, such effects may cause unpredicted and deleterious changes in other populations that could reduce or even negate the benefit to endangered species for which control is undertaken. Furthermore, the complexity and nonlinearities inherent in interacting ecological communities may cause thresholds in the strength of pest control, on either side of which indirect effects could vary greatly in their magnitude and desirability. We constructed a four-species simulation model for a common pest community in New Zealand beech (Nothofagus spp.) forests: house mice, ship rats, stoats, and brushtail possums. When the model was perturbed to simulate common control techniques, marked increases in the abundance of nontarget pest species were observed at the next forest mast. Higher mouse numbers were observed following both toxin (1080) application and rat kill-trapping, and higher rat numbers were observed following stoat kill-trapping, due to a release from predation in all cases. In comparison, a marked decrease in stoat abundance at the next forest mast was observed following simultaneous control of rats and mice, due to the effects of decreased prey abundance on the stoat population. For rat control, the size of the indirect effect on mouse numbers increased monotonically with control strength. Because the curvature of the relationship is slight, the relationship between the direct benefits of control and the indirect costs incurred would remain relatively unchanged regardless of the strength of control employed. For simultaneous mouse and rat control, however, high levels of control (as initially simulated) were predicted to cause decreased peak stoat abundance at the next mast event, whereas intermediate and low levels of control were predicted to cause increased stoat abundance. Hence, this study demonstrates two points of concern for pest managers. First, indirect effects of control operations do have the potential to reduce the planned-for benefit. Second, thresholds in the strength of control employed can potentially occur, across which indirect effects switch from being of conservation benefit to being of conservation concern.     

豪猪的发情观察及其鉴定方法初探

1999年3月至2001年12月在湖南省衡东县特种经济动物研究所豪猪养殖场采用外生殖器观察、阴道分泌物涂片镜检、行为表现观察和放对试情等方法，对雌雄豪猪进行发情观察与鉴定．结果表明：豪猪的发情期有三个阶段，即发情前期，发情旺期和发情后期，其中发情旺期是豪猪的最佳配种时期．此期雌豪猪阴门表现出明显肿胀，呈现圆形，触摸有弹性，呈粉红色，阴道分泌物涂片镜检可见有核细胞和无核细胞；放对试情雌豪猪主动接近雄豪猪，发生交配行为．     

高校生态文明道德教育进课堂途径探析

大学生是具有较高觉悟和文化素质的公民群体,是未来中国社会发展、建设"美丽中国"的重要力量,同时又是人类环境的保护者、创造者.推进高校生态文明道德教育进课堂,培养大学生生态道德观、价值观,有效提升学生生态文明素质已成为当务之急.文章阐述了高校加强生态文明道德教育的必要性,分析了当前高校生态文明道德教育中存在的主要问题,提出了高校生态文明道德教育进课堂的主要途径.参5.     

论高职院校新生的心理特点及教育方法

针对高校新生心理特点，提出教育的四种方法．即：帮助新生克服思想上的满足感，树立新的奋斗目标；帮助新生克服生活上的依赖性，增强自主意识和自理能力；帮助学生克服心理上的孤独感，学会正确处理人际关系；切实改进高校新生思想政治教育方法．     

探究式教学在中等学校生物教学中的应用

探究式教学凭自身的特点,打破了以往生物教学的旧模式,积极主动地探究问题的实质,培养学生对生物的兴趣,从而使学生的创造性和创新能力得到更好的锻炼.