Chemical compounds of the foraging recruitment pheromone in bumblebees

When the frenzied and irregular food-recruitment dances of bumblebees were first discovered, it was thought that they might represent an evolutionary prototype to the honeybee waggle dance. It later emerged that the primary function of the bumblebee dance was the distribution of an alerting pheromone. Here, we identify the chemical compounds of the bumblebee recruitment pheromone and their behaviour effects. The presence of two monoterpenes and one sesquiterpene (eucalyptol, ocimene and farnesol) in the nest airspace and in the tergal glands increases strongly during foraging. Of these, eucalyptol has the strongest recruitment effect when a bee nest is experimentally exposed to it. Since honeybees use terpenes for marking food sources rather than recruiting foragers inside the nest, this suggests independent evolutionary roots of food recruitment in these two groups of bees.     

瑞典南部一酸性地区和一碱性地区女性头发中微量元素浓度问题

通过对瑞典南部一个酸性环境地区47名女性头发中34种微量元素浓度的测定,将其结果与某碱性环境地区43名女性的结果进行对比.利用感应耦合等离子光学发射光谱和感应耦合等离子质谱分析法测定头发和饮用水中这些元素的浓度.来自酸性地区的头发样本中硼和钡的浓度明显要高些(p＜0.001),而碱性地区头发样本中的钙、锶、钼、铁、硒浓度明显增高(p＜0.001).对有些金属元素,如钙、铅、钼和锶来说,其在头发中和水中的浓度是呈正相关的(r.=0.34～0.57;p≤0.001),显示了摄入水中矿物质的重要性.取自碱性地区头发样本中的硒/汞比率的增加(p＜0.001)说明这些受试者可能对汞的毒性有更好的防护.     

Comparing systems approaches to innovation and technological change for sustainable and competitive economies: an explorative study into conceptual commonalities,differences and complementarities

This paper makes a distinction between three theoretical frameworks that have been highly influential in the discourse on innovation, competitiveness and sustainability: sectoral systems of innovation (SSI), technological innovation systems (TIS) and socio-technical systems (ST-Systems). These frameworks share a common systems approach to innovation but are often positioned as different bodies of literature that correspond to different epistemic communities. This paper is explorative and conceptual in nature. It presents a systematic comparative review of SSI, TIS and ST-Systems based on the following analytical dimensions: (1) system boundaries, (2) actors and networks, (3) institutions, (4) knowledge, (5) dynamics and (6) policy approach. In the concluding section commonalities and differences, of the three approaches, are presented and suggestions for complimentarily are made.     

耕作和混合农业体系未来植物养分利用的前景和挑战

在不污染环境的情况下生产足量的健康食品对未来世界农业是一个严重挑战.瑞典"21世纪的食物"研究计划已经研究了可持续耕作体系的经济的、环境的以及社会的各个方面,本文列举了瑞典"21世纪的食物"研究计划以及其它相关的国际研究计划中注重改善养分利用效率的一些研究,特别是氮和磷.它表明有许多可持续性解决养分利用效率的方法,有些很复杂,但有些就很简单.政府政策包括津贴、研究和技术以及公众对耕作方式的认可,所有这些都与制定这些解决方法结合在一起.需要知识转让的参与式途径,这样科学家、政策决策者、农场主、顾问以及消费者们可以交流信息,一起构建可持续的耕作体系.     

气候变化与紫外线B辐射对北极苔原和极地荒漠生态系统的影响重要发现和扩展总结

引言 北极已成为对当前气候波动和预计的全球变暖增强的影响进行评估的重要地区.原因有以下几个方面:①在过去几十年中北极经历了大幅度的变暖过程(温度平均升高3℃,而在许多地区温度升高了4～5℃);②气候预测表明气候呈现持续变暖趋势,在2080年之前年平均气温升高4～5℃;③近期的气候变暖正在影响北极的环境和经济,这些影响还会加大,并对生活方式、文化及生态系统造成影响;④北极的变化可能会影响到地球上的其它地区.     

基本原理,概念及评估办法

引言 人们普遍认为,全球气候变暖在北极将进一步放大,由于平流层臭氧修复的可能延误,紫外线B(UV-B)辐射可能继续增加,北极环境及其居民可能特别易受这类环境变化的影响.上述共识促进了对气候变化影响的国际评估工作.北极气候影响评估(ACIA)是一项为时4年的研究,结果出版了一篇重要的科研报告[1]并产生了其他的成果.在本文以及本期Ambio专刊下面的文章中,我们提供了报告中针对北极陆地生态系统(从树线群落交错带到极地荒漠)的部分研究成果.     

气候变化对景观和区域过程的影响及其对气候系统的反馈

北极生态系统的生物和物理过程会在不同的时间、空间尺度上对地球生态系统产生反馈作用,并与之相互影响.气候变化对北极地区的影响及其对全球气候系统的反馈主要存在着四种潜在机制反照率改变、生态系统对温室气体的排放或吸收、甲烷类温室气体的排放、影响海洋暖流淡水量的增长.这些反馈机制在某种程度上是由生态系统的分布和特征,尤其是大规模植被区域变化来控制的.通过少量全年的CO2通量测量表明,目前在地理分布上碳源区要比碳汇区要多.根据目前现有的关于CH4排放源地信息表明,景观规模上的CH4排放量对北极地区的温室效应平衡至关重要.北极地区的能量和水量平衡在变化的气候下,也是一个很重要的反馈机制.植被密度以及分布范围的增加会导致反射率的下降,因而会使地表吸收更多的能量.其效果可能会抵消由于极地沙漠地带向极地苔原带的的转化,或极地苔原带向极地森林带的转化,而造成的植被总净初级生产力碳沉降能力的提高而引起的负反馈.永久冻土带的退化对示踪气体动力学有着很复杂的影响.在不连续的永久冻土带地区,升温将会导致其完全消失.依赖于当地水文条件,温室气体排放可能由于气候环境变的干燥或湿润而使得其通量有所变化.总的来说,影响反馈的各种过程复杂的相互作用,以及这些过程随着时间地点的变化,加之数据的缺乏,又会在陆地生态系统气候变化对气候系统产生反馈作用的净效应估计上,产生许多的不确定性,这种不确定性将会影响到一些反馈的大小和方向.     

从亚马孙泛滥平原森林中获取林产品的经济重要性

秘鲁亚马孙流域的农民从事农业,同时从天然林,河流和湖泊中获取各种各样的产品,他们多样化的生活方式包括捕鱼,狞猎和采集植物产品.在2个泛滥平原的村庄里,我们已经收集了一年的资料对当地农业经济与为满足生活基本需求和商业贸易的林业经济进行比较.此研究中的林产品包括动物产品(狞猎和捕鱼)和植物产品(木材和非木材).结果表明为了生活需要而获取的林产品尤其是鱼,是当地经济的支柱.获取林产品的日净收入高于种植和非熟练工人正常的日工资收入,这说明在实施任何土地开发利用的决策之前对社会经济情况进行全面的调查研究显得尤为重要.每公顷天然林可获取林产品的价值为平均每年13美元,平均每户可利用的天然林面积为113hm2.如果把农业产出也计算在内的话,每公顷土地的总产值(包括农业和林业)就上升到每年21美元.     

Revising REACH guidance on information requirements and chemical safety assessment for engineered nanomaterials for aquatic ecotoxicity endpoints: recommendations from the EnvNano project

The European Chemical Agency (ECHA) is in the process of revising its guidance documents on how to address the challenges of ecotoxicological testing of nanomaterials. In these revisions, outset is taken in the hypothesis that ecotoxicological test methods, developed for soluble chemicals, can be made applicable to nanomaterials. European Research Council project EnvNano—Environmental Effects and Risk Evaluation of Engineered, which ran from 2011 to 2016, took another outset by assuming that: “The behaviour of nanoparticles in suspension is fundamentally different from that of chemicals in solution”. The aim of this paper is to present the findings of the EnvNano project and through these provide the scientific background for specific recommendations on how ECHA guidance could be further improved. Key EnvNano findings such as the need to characterize dispersion and dissolution rates in stock and test media have partially been addressed in the updated guidance. However, it has to be made clear that multiple characterization methods have to be applied to describe state of dispersion and dissolution over time and for various test concentration. More detailed information is called for on the specific characterization methods and techniques available and their pros and cons. Based on findings in EnvNano, we recommend that existing algal tests are supplemented with tests where suspensions of nanomaterials are aged for 1–3 days for nanomaterials that dissolve in testing media. Likewise, for daphnia tests we suggest to supplement with tests where (a) exposure is shortened to a 3 h pulse exposure in daphnia toxicity tests with environmentally hazardous metal and metal oxide nanomaterials prone to dissolution; and (b) food abundance is three to five times higher than normal, respectively. We further suggest that the importance of considering the impact of shading in algal tests is made more detailed in the guidance and that it is specified that determination of uptake, depuration and trophic transfer of nanomaterials for each commercialized functionalization of the nanomaterials is required. Finally, as an outcome of the project a method for assessing the regulatory adequacy of ecotoxicological studies of nanomaterials is proposed.