Urban tinkering

Cities are currently experiencing serious, multifaceted impacts from global environmental change, especially climate change, and the degree to which they will need to cope with and adapt to such challenges will continue to increase. A complex systems approach inspired by evolutionary theory can inform strategies for policies and interventions to deal with growing urban vulnerabilities. Such an approach would guide the design of new (and redesign of existing) urban structures, while promoting innovative integration of grey, green and blue infrastructure in service of environmental and health objectives. Moreover, it would contribute to more flexible, effective policies for urban management and the use of urban space. Four decades ago, in a seminal paper in Science, the French evolutionary biologist and philosopher Francois Jacob noted that evolution differs significantly in its characteristic modes of action from processes that are designed and engineered de novo (Jacob in Science 196(4295):1161–1166, 1977). He labeled the evolutionary process “tinkering”, recognizing its foundation in the modification and molding of existing traits and forms, with occasional dramatic shifts in function in the context of changing conditions. This contrasts greatly with conventional engineering and design approaches that apply tailor-made materials and tools to achieve well-defined functions that are specified a priori. We here propose that urban tinkering is the application of evolutionary thinking to urban design, engineering, ecological restoration, management and governance. We define urban tinkering as:

A mode of operation, encompassing policy, planning and management processes, that seeks to transform the use of existing and design of new urban systems in ways that diversify their functions, anticipate new uses and enhance adaptability, to better meet the social, economic and ecological needs of cities under conditions of deep uncertainty about the future.

This approach has the potential to substantially complement and augment conventional urban development, replacing predictability, linearity and monofunctional design with anticipation of uncertainty and non-linearity and design for multiple, potentially shifting functions. Urban tinkering can function by promoting a diversity of small-scale urban experiments that, in aggregate, lead to large-scale often playful innovative solutions to the problems of sustainable development. Moreover, the tinkering approach is naturally suited to exploring multi-functional uses and approaches (e.g., bricolage) for new and existing urban structures and policies through collaborative engagement and analysis. It is thus well worth exploring as a means of delivering co-benefits for environment and human health and wellbeing. Indeed, urban tinkering has close ties to systems approaches, which often are recognized as critical to sustainable development. We believe this concept can help forge much-closer, much-needed ties among engineers, architects, evolutionary ecologists, health specialists, and numerous other urban stakeholders in developing innovative, widely beneficial solutions for society and contribute to successful implementation of SDG11 and the New Urban Agenda.

     

我国城市内涝灾害的影响因子及气象服务对策

近年来,一场暴雨导致某座现代化大都市部分功能瘫痪、生命财产损失惨重的案例屡见不鲜。以山西为例,通过分析认为城市化导致大城市降水量和强降水事件增多、城市规划和排水管网建设滞后、完善的城市内涝灾害气象服务体系尚未建立等是造成城市内涝灾害加重的主要原因,并提出城市内涝气象服务对策建议。     

Accumulation of perfluorinated compounds in captive Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) in China

The accumulation of perfluorinated compounds (PFCs) in the sera of captive wildlife species Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) from Harbin Wildlife Park, Heilongjiang Province, in China were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the predominant contaminant with a mean serum concentration of 1.18 ng mL(-1) in tigers and 2.69 ng mL(-1) in lions. Perfluorononanoic acid (PFNA) was the second most prevalent contaminant in both species. The composition profiles of the tested PFCs differed between tigers and lions, and the percentages of perfluorooctanoic acid (PFOA) were greater in lions than in tigers, indicating different exposures and/or metabolic capabilities between the two species. Assessments of the risk of PFC contamination to the two species were obtained by comparing measured concentrations to points of departure or toxicity reference values (TRVs). Results suggest no risk of PFOS exposure or toxicity for the two species.     

白洋淀地区污染状况的生物毒性评价

从1992年10月到1994年4月先后几次对白洋淀集水区,包括淀区及排污河道等十几个样点进行了水样采集和多指标生物毒性检验。选用的生物组合包括：荧光发光菌（Photobacteriumphosphorum）、斜生栅藻（Scenedesmusobliqnus）和大型（Daphiniamagna）,罗非鱼（Tilapiamossambica）鱼肝细胞毒性检验,结果表明大部分样品对光合藻有明显刺激生长的作用。污水库沿线和安新县排污渠水样对浮游动物有毒性作用。府河沿线的水样仅对鱼肝细胞有毒性作用,对发光菌无明显抑制。这些潜在的生物毒性效应是否会影响白洋淀淀区的水生生态系统,需进一步深入研究。     

三峡库区出露期消落带沉积物磷分布特征

为了揭示经历完整反季节干湿交替周期消落带沉积物磷的源汇转化趋势,分析了三峡库区出露期消落带沉积物中磷酸盐的分布特征及含量变化.结果表明,首次经历完整反季节干湿交替的消落带宏观上表现出沉积物总磷(TP)累积现象,但覆水沉积物TP>落干沉积物TP,表明夏季水库开闸放水排沙,且消落带夏季出露期降雨资源丰富,有利于出露消落带表层沉积物被冲刷排除.有机磷(Or-P)含量升高是导致首次经历完整反季节干湿交替的消落带沉积物总磷积累的主要原因.消落带反季节干湿交替有利于沉积物中活性较高的活性磷(Ac-P)、Or-P的累积,有利于相对稳定的闭蓄态磷(O-P)、钙磷(Ca-P)排出.     

流域水生态风险评价及管理对策

流域水生态风险评价是流域水环境管理急需解决的难题和研究热点,与传统风险管理的主要不同点在于流域的异质性和复合污染问题.依靠单一污染物研究不足以提供全面风险信息,无法适应我国流域水环境改善和生态恢复的管理需求.本文通过对复合污染的联合毒性效应及其研究方法的分析,综述和比较了生态风险评价方法的实用性和不足,探讨适合于建立流域不同生态单元质量和复合污染效应间关系的方法,发展和构建反映流域时空尺度变化规律的生态风险评价模型.并就流域水生态毒理机理、水环境的生态响应时空异质性变化规律和流域多目标优化管理提出研究展望及管理对策.     

蚯蚓细胞色素P450亚酶及代谢组学对土壤亚致死剂量草甘膦除草剂的响应

以赤子爱胜蚓（Eisenia fetida）为受试生物,通过外源添加污染物的方法,研究了暴露于亚致死剂量草甘膦（添加剂量分别为5、10、20、40 mg·kg^-1）的土壤中7 d后,蚯蚓生长抑制率、细胞色素P450亚酶（CYP1A2、2C9与3A4）活力及代谢组学对土壤草甘膦的响应,旨在探讨亚致死剂量草甘膦能否对非靶标生物蚯蚓产生不良影响及其毒性作用机制,初步推断其毒性作用阈值,并筛选敏感生物标记物.结果表明：从蚯蚓生长抑制率来看,各处理组与对照组无显著差异;从蚯蚓CYP亚酶活力来看,在高剂量草甘膦（20、40 mg·kg^-1）处理下,CYP亚酶活力均受到显著抑制;基于代谢组学鉴定并筛选出14个小分子代谢物标记物,其中9个小分子代谢物（分别是1,6-二磷酸果糖、β-D-果糖6-磷酸、丙酮酸、组氨酸、赖氨酸、鸟氨酸、延胡索酸、肌酸、甜菜碱）在5~40 mg·kg^-1草甘膦暴露下显著低于对照水平,另外2个小分子代谢物（尿酸与二十-羟-二十烷四烯酸）则在草甘膦处理下显著升高.代谢组学的响应表明,草甘膦暴露（5~40 mg·kg^-1）致使蚯蚓糖酵解与三羧酸循环减弱,氨基酸代谢受损,嘌呤代谢紊乱,细胞渗透功能受损,对蚯蚓产生了明显毒副作用,其毒副作用还与细胞色素P450酶代谢相关.蚯蚓CYP亚酶活力与小分子代谢物标记物作为敏感生物标记物,可联合诊断土壤亚致死剂量草甘膦污染.     

Heavy metal induced ecological risk in the city of Urumqi, NW China

A total of 169 samples of road dust collected in the city of Urumqi, capital of the Xinjiang Uygur Autonomous Region in northwest China, were analyzed by method of inductively coupled plasma-mass spectrometry for 10 elements (i.e., Cd, Cr, Cu, Ni, Pb, Mn, Be, Co, Zn, and U). The possible sources of metals are identified with multivariate analysis such as correlation analysis, principal component analysis, and cluster analysis. Besides, enrichment factors are used to quantitatively evaluate the influences of human activities on heavy metal concentrations. Moreover, the potential ecological risk index is applied to evaluating the ecological risk of heavy metal pollutants. The results indicate that: (1) the concentrations of the heavy metals involved were much higher in urban areas than the background values, except those of Co and U. Mn, U, and Co are mainly of natural origin; Cu, Pb, Zn, and Cr are mainly of traffic sources and are partly of industrial sources; Ni and Be are mainly the results of industrial activities, such as machine shops, firepower plants, tire and rubber factories, cement factories, and textile mills and are partly of the traffic sources; (2) with high “toxic-response” factor and high concentration, Cd has more serious influences on the environment than other heavy metals. Therefore, commercial and industrial areas are usually characterized by higher potential ecological risk when compared with residential areas and new developing urban areas. The results of this study could be helpful for the management of environment in industrial areas.     

Pesticide contamination profiles of water, sediment and aquatic organisms in the effluent of Gaobeidian wastewater treatment plant

Organochlorine pesticides (OCPs, including DDT, HCH and HCB) and six indicator polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, and 180) were measured in water, sediment, zooplankton, fish and Chinese softshell turtle (Pelodiscus sinensis) from Gaobeidian Lake, which is located in the effluent of Gaobeidian wastewater treatment plant (WWTP) in Beijing, China. DDTs were dominant except for in water. In water, the concentrations of DDTs (6.22 ng l(-1)) and HCHs (18.0 ng l(-1)) were less than the limits (l000 ng l(-1) for DDTs and 5000 ng l(-1) for HCHs). However, PCBs concentration (20.8 ng l(-1)) exceeded the limit (14 ng l(-1)) suggested by the United States Environmental Protection Agency (USEPA). The high ratio of p,p'-DDT/DDTs (0.80) in water suggested that DDTs had recently been discharged into the ambient environment despite a longtime ban in China. For fish and Pelodiscus sinensis, the accumulation patterns of OCPs and PCBs were different in muscle and liver. And HCB and PCB 153 were significant different in different species (p<0.05). PCBs were dominated by PCB 52 in zooplankton, but by PCB 138 and 153 in Pelodiscus sinensis. The highest food web magnification factor (FWMF) was 4.83 for p,p'-DDT and the second highest was 4.36 for PCB 101 in Gaobeidian Lake. As compared with the other studies, biomagnification in the present study was not obvious. Trophic levels and age were two important factors that might contribute to the bioaccumulation in the present study.     

活性炭纤维的改性及其微孔结构

采用微波辐射、硝酸回流、微波-硝酸处理和氢氧化钠水溶液浸渍改性了粘胶基活性炭纤维,并对其改性机制进行了探讨.利用氮吸附对改性活性炭纤维的孔隙结构进行了表征.结果表明,除碱改性活性炭纤维外,其余改性活性炭纤维的BET表面积增加、微孔容量增大、对氮气的亲和力增强,而且微波辐射改性可使活性碳BET表面积大大增加.活性炭纤维表面呈双重分维特征.