Windows of opportunity: addressing climate uncertainty through adaptation plan implementation

There is a pressing need for municipalities and regions to create urban form suited to current as well as future climates, but adaptation planning uptake has been slow. This is particularly unfortunate because patterns of urban form interact with climate change in ways that can reduce, or intensify, the impact of overall global change. Uncertainty regarding the timing and magnitude of climate change is a significant barrier to implementing adaptation planning. Focusing on implementation of adaptation and phasing of policy reduces this barrier. It removes time as a decision marker, instead arguing for an initial comprehensive plan to prevent maladaptive policy choices, implemented incrementally after testing the micro-climate outcomes of previous interventions. Policies begin with no-regrets decisions that reduce the long-term need for more intensive adaptive actions and generate immediate policy benefits, while gradually enabling transformative infrastructure and design responses to increased climate impacts. Global and local indicators assume a larger role in the process, to evaluate when tipping points are in sight. We use case studies from two exemplary municipal plans to demonstrate this method's usefulness. While framed for urban planning, the approach is applicable to natural resource managers and others who must plan with uncertainty.     

Genetic structure and different color morphotypes suggest the occurrence and bathymetric segregation of two incipient species of Sebastes off Argentina

Rockfishes of the genus Sebastes are extensively distributed in the Pacific and Atlantic oceans. Although the occurrence of two morphologically similar species in the Southern Hemisphere, Sebastes oculatus and Sebastes capensis, is now clearly established, the taxonomic status and phylogeographic patterns for the genus in the region have not yet been completely resolved. In this study, we provide new insights into the taxonomy and evolutionary relationships of rockfishes inhabiting the Southwestern Atlantic Ocean, off the coast of mainland Argentina, by combining mitochondrial DNA (mtDNA) control region sequences, microsatellite data, and color pattern analyses. Differences in coloration (“dark” and “light” fish) together with bathymetric segregation between color morphotypes were evident from fish collection and literature review. In addition, the mtDNA phylogenetic analysis and Bayesian clustering analysis using microsatellite data separated the fish into two distinct groups (F _ST?=?0.041), most likely representing incipient species. Our results suggest that speciation-by-depth in the absence of physical barriers could be a widespread mechanism of speciation in Sebastes from both the Northern and Southern Hemispheres. Nevertheless, the degree of genetic differentiation found, added to the large number of individuals displaying high levels of admixture, points to the occurrence of incomplete reproductive barriers between color morphotypes. Beyond the taxonomic and phylogeographic implications of our findings, the occurrence of distinct groups of Sebastes off the coast of Argentina being targeted by different fisheries (angling and trawling) has consequences for the design and implementation of appropriate fishery regulations to avoid overharvest of either group.     

Quantification of changes in zero valent iron morphology using X-ray computed tomography

Morphological changes within the porous architecture of laboratory scale zero valent iron （ZVI） permeable reactive barriers （PRBs）, after exposure to different groundwater conditions, have been quantified experimentally for different ZVI/sand ratios （10%, 50% and 100%, W/W） with the aim of inferring porosity changes in field barriers. Column studies were conducted to simulate interaction with different water chemistries, a synthetic groundwater, acidic drainage and deionised （DI） water as control. Morphological changes, in terms of pore size and distribution, were measured using X-ray computed tomography （CT）. CT image analysis revealed significant morphological changes in columns treated with different water chemistries. For example, 100% ZVI （W/W） columns had a higher frequency of small pores （0.6 mm） was observed in ZVI grains reacted with typical groundwater, resulting in a porosity of 27%, compared to 32% when exposed to DI water. In comparison, ZVI grains treated with the acidic drainage had higher porosity （44%） and larger average pore size （2.8 mm）. 10% ZVI PRB barrier material had the highest mean porosity （56%） after exposure to any water chemistry whilst 100% ZVI （W/W） columns always had the lowest （34%） with the 50% ZVI （W/W） in between （40%）. These results agree with previously published PRB field data and simultaneously conducted geochemical monitoring and mass balance calculation, indicating that both the geochemical and hydraulic environment of the PRB play an important role in determining barrier lifespan. This study suggests that X-ray CT image analysis is a powerful tool for studying the detailed inter pores between ZVI grains within PRBs.     

TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water

The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products (DBPs). Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the environment. Only a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes (THMs) and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water.     

The impact of iodinated X-ray contrast agents on formation and toxicity of disinfection by-products in drinking water

The presence of iodinated X-ray contrast media (ICM) in source waters is of high concern to public health because of their potential to generate highly toxic disinfection by-products (DBPs). The objective of this study was to determine the impact of ICM in source waters and the type of disinfectant on the overall toxicity of DBP mixtures and to determine which ICM and reaction conditions give rise to toxic by-products. Source waters collected from Akron, OH were treated with five different ICMs, including iopamidol, iopromide, iohexol, diatrizoate and iomeprol, with or without chlorine or chloramine disinfection. The reaction product mixtures were concentrated with XAD resins and the mammalian cell cytotoxicity and genotoxicity of the reaction mixture concentrates was measured. Water containing iopamidol generated an enhanced level of mammalian cell cytotoxicity and genotoxicity after disinfection. While chlorine disinfection with iopamidol resulted in the highest cytotoxicity overall, the relative iopamidol-mediated increase in toxicity was greater when chloramine was used as the disinfectant compared with chlorine. Four other ICMs (iopromide, iohexol, diatrizoate, and iomeprol) expressed some cytotoxicity over the control without any disinfection, and induced higher cytotoxicity when chlorinated. Only iohexol enhanced genotoxicity compared to the chlorinated source water.     

美国1961～2000年氮使用量的变化及未来趋势预测

从1961～1997年,因人类活动而输入到美国的氮翻了一番,特别是在上个世纪60年代和70年代,其增长量最大.尽管无机氮肥的使用量增长最大,但矿物燃料燃烧所造成的NOx排放,也有明显的增加.1961年,美国农业生产系统中的生物固氮量是活性氮的最大来源;到了1997年,尽管生物固氮量也有增加,但相比而言,无机氮肥的使用和NOx的排放增加得更快,成为两个最大的氮源.1961～1997年,在输入到美国的活性氯中,有2/3发生了脱氮反应或者是被贮存在土壤与生物群落之中,有1/3输出到境外.在输出到境外的这部分氮中,通过河流流到海洋中的分量最大,其次是通过粮食和饲料出口而到其它国家以及通过大气平流传输到了海洋中.动物性蛋白的消费是美国农业系统中氮使用的主要驱动因子,如果饮食方式或农业生产方式不发生改变,在未来30年的时间里,美国肥料的使用量将继续增长,流向海洋中的氮通量将可能再增长30%,但也有可能出现下降.     

A simple procedure for obtaining fetal chromosome preparations from bloodstained amniotic fluid

Two patients undergoing amniocentesis are described in which the resulting amniotic fluid was unavoidably bloodstained. The results suggest that it may be beneficial in such cases to reserve a small volume of bloodstained liquor for culture with phytohaemagglutinin since the presence of a few fetal lymphocytes can lead to a prenatal diagnosis within 72 h.     

东盟环境合作

本文从国际准则和政治的角度就东南亚各国对环境问题的看法进行了探讨，并对东南亚地区污染的具体情况和相应的区域性解决方法中出现的具体趋势，以及东盟的具体政策作了介绍。     

Potential effects of environmental contamination on Yuma Myotis demography and population growth.

Unplanned natural and anthropogenic disasters provide unique opportunities for investigating the influence of perturbations on population vital rates and species recovery times. We investigated the potential effects of a major pesticide spill by comparing annual survival rates using mark-recapture techniques on a riparian bat species, Yuma Myotis (Myotis yumanensis). Demography and population dynamics for most bat species remain poorly understood despite advances in mark-recapture estimation and modeling techniques. We compared survival and population growth rates of two roost populations exposed to a large chemical (metam sodium) spill in the upper Sacramento River in Northern California with two roost populations outside the contaminated area from 1992 to 1996. Hypotheses about long-term effects of the spill on female juvenile and adult survival were tested using an information-theoretic approach (AIC). Working hypotheses included effects of age, chemical spill, and time trend on survival. Female adult survival was higher than female juvenile survival across all sites, suggesting stage-specific mortality risks. Model-averaged estimates of female juvenile survival in the contaminated area (0.50-0.74) were lower than in control roosts (0.60-0.78) for each year in the study, suggesting that the spill may have reduced juvenile survival for several years. Female adult survival (0.73-0.89) did not appear to be strongly affected by the spill during the years of the study. There was an increase in survival for both stage-classes across all populations during the study period, which may have been caused by the end of an extended drought in California in the winter of 1993. The spill-affected population was in decline for the first year of the study as indicated by an estimated growth rate (lambda) < 1, but population growth rates increased during the four-year period.