Evolutionary aspects of perfume collection in male euglossine bees (Hymenoptera) and of nest deception in bee-pollinated flowers

Summary A fascinating pollination system has been evolved between perfume producing flowers and perfume collecting male euglossine bees in the neotropics. Detailed investigations have contributed to an understanding of the interactions between euglossine males and flowers as a pollination system. The role which the collected perfume plays in the reproductive behaviour of euglossine bees is not fully understood. A favoured hypothesis suggests that the collected fragrances are used as precursors for male sex pheromones and thus serve to attract conspecific males or females. It is not known how perfume collection behaviour evolved. Here, an evolutionary approach presents a new hypothesis which suggests that the evolution of perfume collection in euglossine males is based upon pre-existing signals which were attractive to females and males. It is further suggested that, at the evolutionary outset, flowers mimicked nest sites to deceive nest-seeking euglossine bees. In addition, a comparative study was undertaken on the phenomena of nest-mimicking flowers in related bee families.     

Aquatic litter, management and prevention—the role of measurement

Methodology of litter management has many forms and increasingly measurement is linked to management. By providing measured profiles of the quality of litter types, trends in the input of new items can be assessed and prevention programmes directed more effectively to sources. Developing methodologies and their application to management cover three main areas.

企业环境污染行为的经济学研究

从经济学和委托代理理论出发构建非国有企业和国有企业环境污染行为产生的成本－收益决策模型，分析了污染行为产生的根本动因，并据此提出控制企业环境污染行为有效可行的政策。     

不同土壤重金属复合污染的有效态离子冲量表征

选择红壤、黄棕壤和潮土为对象，依据中国土壤环境质量二级和三级标准确定土壤重金属铜、锌、镉的污染浓度，通过生物盆裁试验研究在重金属Cu、Zn、Cd复合污染条件下牧草（黑麦草、紫花苜蓿）体内重金属含量和土壤中重金属有效态含量的相关性，结果表明，在3种不同性质的污染土壤上，牧草体内重金属的离子冲量与其对应土壤中重金属有效态的离子冲量之间均存在明显的相关性。校正土壤pH、牧草品种等因素后，土壤有效态离子冲量可以有效表征不同土壤-牧草系统的重金属复合污染。     

室内霉菌污染原因及其控制对策

通过对建筑墙体内湿气迁移过程的研究，详细分析了霉菌污染产生的原因。通过夏、冬两季平均气候条件下沿墙厚度温度、相对湿度分布和湿积累量的具体计算，得出墙内的相对湿度将达到或超过70％，有时甚至处于饱和状态，从而为霉菌的生长提供了有利条件。基于分析结果，提出了对于室内霉菌污染的控制对策。     

Dioxin removal in “energy from waste plants” - comparison of air pollution control methods

The graph below shows the emitted dioxin - equivalents (Eadon) in grams per year in flue gas from municipal solid waste incinerators with various air pollution control methods for plants of capacity of 200 000 ton municipal solid waste (MSW) per year.

Full-size image (15K)

With optimized combustion and an effective air pollution control system the emissions of dioxins can be kept very low (concentrations below 0.1 ng/m³n).

With a very effective air pollution control system the total emission from all Swedish MSW-incinerators burning approximately 1.5 Mton/year will by 1990 be below 2 g/year - a drastic reduction from approximately 15 g today. As the total dioxin - equivalent emission to the environment in Sweden in the year 1987 was almost 500 g we see that municipal waste incineration really is on the way to solve their dioxin problem.     

西安地区旅游景点水体卫生细菌学调查及保护对策

以粪大肠菌和异养细菌总数做指标，对西安地区旅游景点水体的卫生细菌学状况进行了调查。结果表明，西安市区内旅游景点的人工湖、天然湖等大都受到不同程度的污染，而离市区较远、海拔较高的旅游景点则污染较轻。     

Development of a ‘Matrix Scoring Technique’ to determine litter sources at a Bristol Channel beach

Litter at beaches can come from more than one source and determining the proportions to assign pollution to different sources is very complex. There is no widely accepted methodology at present that links litter items to their source. The aim of this study was to create a method of assigning a source to litter found on beaches of the Bristol Channel but which could equally be used on any beach. Various methods that attempt to establish the source of beach litter were evaluated; their strengths, weaknesses, applicability and reliability for use on Bristol Channel, UK beaches were considered. Elements of existing methods coupled with new ideas were utilized in the production of a ‘refined’ methodology: consequently a new method of assigning a source to beach litter was developed. The developed ‘Matrix Scoring Technique’ was applied to data collected at Minehead beach on the Bristol Channel, UK. Several numerical and nomenclature variations were used to produce a system that reflected the various sources and eliminated as much bias as possible. This cross-tabulated matrix scoring system can produce an insight into the contribution of different source groups to litter found on beaches. This novel approach requires further testing with emphasis on a control data set.     

Inorganic mercury and methylmercury in surface sediments and mussel tissues from a microtidal lagoon (Bizerte, Tunisia)

The aim of this study was to investigate the distribution of mercury compounds in marine sediments and mussel tissues collected in the lagoon of Bizerte, Tunisia, during two seasons (summer and winter). Inorganic mercury (Hg²⁺) concentrations in sediments were found to be highly variable, ranging from 0.04 nmol.g¹ to 3.22 nmol.g⁻¹ (dry weight) with a mean value of 0.52 nmol.g⁻¹. Anthropogenic sources of Hg²⁺, most probably metallurgy or tire production industries, have been evidenced. The mean concentration of monomethylmercury (MeHg⁺) in the surface sediments is 2.32 pmol g⁻¹ ranging from below the detection limit (0.45 pmol.g⁻¹) to 14.6 pmol.g⁻¹. No significant variation was observed between winter and summer seasons for both mercury species concentration in the sediments. The Hg²⁺ concentrations in mussel tissues are also variable, ranging from 0.007 to 1.347 nmol.g⁻¹ (dry weight). The mean concentration is 0.70 nmol.g⁻¹. In these tisssues, Hg²⁺ is generally the major compound, making up ca. 88% of total mercury concentrations. However, methylmercury concentrations are significant and homogeneous, ranging from 62 to 121 pmol.g⁻¹ (mean 96 pmol.g⁻¹). The results suggest that a fraction of the inorganic mercury load in the sediments of the lagoon undergoes methylation pathways. MeHg⁺ produced is assimilated in the mussels more readily than Hg²⁺.     

河流水质全球变化研究若干问题

本文首先简要阐述自本世纪50年代以来全球河流水质研究与水质监测的基本情况,进而就河流水质全球变化研究中的几个难点问题进行讨论。这些问题是:1)河流水质的多样性及全球参比值问题,2)河流水质监测的发展及存在问题,3)与社会-经济发展有关的河流水质全球变化趋势分析。