雪貂和旱獭作为胃癌病因研究的实验模型

本项研究是以雪貂（Ｆｅｒｒｅｔ）和旱獭（Ｗｏｏｄｃｈｕｃｋ）作为实验动物模型，由于这两种动物的某些器官特征在解剖学上和生理学上与人类有其相似之处，试图通过雪貂和旱獭体内生物合成亚硝胺，说明人类暴露于化学致场物亚硝胺的另外一个来源是生物体内合成。同时，用烷基化学致癌物二甲基亚硝胺对旱獭进行ＤＮＡ烷基化的研究，发现由于被旱獭肝炎病毒（ＷＨＶ，ＷｏｏｄｃｈｕｃｋＨｅｐａｔｉｔｉｓＶｉｒｕｓ）感染的旱獭，不仅体内易于合成亚硝胺，而且其肝脏组织ＤＮＡ烷基化的水平高于对照组。以ＤＮＡ烷基化反应产生的烷化核酸碱基作为生物标志（Ｒｉｏｍａｒｋｅｒｓ），对于胃癌高发区人群尿中的烷化核酸碱基进行定量测定，并与低发区相对照，显示两者之间有差异性。本项研究为从动物实验外推到人群的设想提供了启示，还提出了以生物标志作为建立分子流行病学的依据。     

Is there a common metals demand curve?

Previous studies have identified a single, stable and strong correlation between the price of metals and their consumption, such that low priced metals are always used in large amounts and visa versa. Some have interpreted this as evidence that metals share a common demand curve so that a single price elasticity of demand exists. This paper reviews and tests this hypothesis against a number of other possible explanations, including the idea that the relationship is an empirical curiosity. Modifications to the demand curve were tested by allowing metals to have different intercepts and price elasticities. The results from this analysis suggest that metals do not share a common demand curve and that the correlation identified between the price of metals and their level of consumption is an empirical curiosity. As such, the singular price elasticities published in past papers should not be used for assessing future rates of metals substitution.     

Stable-isotope probing of bacterial community for dissolved inorganic carbon utilization in Microcystis aeruginosa-dominated eutrophic water

Dissolved inorganic carbon (DIC) is an important source of carbon in aquatic ecosystems, especially under conditions of increased frequency of cyanobacterial bloom. However, the importance of bacteria in direct or indirect utilization of DIC has been widely overlooked in eutrophic freshwater. To identify the functional bacteria that can actively utilize DIC in eutrophic freshwater during cyanobacterial bloom, stable-isotope probing (SIP) experiments were conducted on eutrophic river water with or without inoculation with cyanobacteria (Microcystis aeruginosa). Our 16S rRNA sequencing results revealed the significance of Betaproteobacteria, with similar relative abundance as Alphaproteobacteria, in the active assimilation of H¹³CO₃^? into their DNA directly or indirectly, which include autotrophic genera Betaproteobacterial ammonia-oxidizing bacteria. Other bacterial groups containing autotrophic members, e.g. Planctomycetes and Nitrospira, also presented higher abundance among free-living bacteria in water without cyanobacteria. Microcystis aggregates showed a preference for some specific bacterial members that may utilize H¹³CO₃^? metabolized by Microcystis as organic matter, e.g. Bacteroidetes (Cytophagales, Sphingobacteriales), and microcystin-degrading bacteria Betaproteobacteria (Paucibacter/Burkholderiaceae). This study provides some valuable information regarding the functional bacteria that can actively utilize DIC in eutrophic freshwater.     

维生素B12对厌氧污泥还原降解8:2FTOH的影响

研究了投加生物催化剂维生素B₁₂（VB₁₂）对厌氧活性污泥还原降解8：2氟调聚醇（8：2FTOH）的影响.结果表明,投加VB₁₂能够改变厌氧活性污泥还原降解8：2FTOH的动力学特性并增加其最终去除率,但投加量存在上下限：当VB₁₂投加量≤1mg/L时,8：2FTOH最终去除量无显著增加;当VB₁₂投加量≥5mg/L时,8：2FTOH最终去除量也不再持续增加.投加所有剂量的VB₁₂均可显著增加8：2FTOH的最终脱氟率.投加VB₁₂对厌氧活性污泥还原降解8：2FTOH去除率和脱氟率的影响并不一致.此外,投加较高浓度的VB₁₂可以抑制厌氧污泥还原降解8：2FTOH过程中多氟代化合物等中间降解产物的积累,提高全氟代化合物等终态降解产物的产率,同时有利于增加8：2FTOH的矿化脱氟率,但却导致了更低的总物质的量回收率.     

Environmental,economic and social costs and benefits of a packaging waste management system: A Portuguese case study

The impact of the management of packaging waste on the environment, economic growth and job creation is analyzed in this paper. This integrated assessment intends to cover a gap in the literature for this type of studies, using the specific case study of the Portuguese packaging waste management system (SIGRE).The net environmental benefits associated with the management of packaging waste, are calculated using the Life Cycle Assessment methodology. The results show that, for the categories studied, the impacts associated to SIGRE's various activities are surpassed by the benefits associated to material and energy recovery, with special focus on recycling. For example, in 2011 SIGRE avoided the emission of 116 kt CO₂ equiv. – the equivalent carbon emission of the electricity consumption of 124.000 households in Portugal.The economic impact of SIGRE is evaluated through Input–Output Analysis. It was found that SIGRE's activities also have a significant economic impact. For example, their added value are ranked amongst the upper third of the economic activities with highest multiplier effect at national level: this means that for each Euro of value added generated within SIGRE, 1.25 additional € are added to the rest of the economy (multiplier effect of 2.25).Regarding the social impacts of SIGRE, the number of direct jobs associated with the system is estimated to be more than two thousand and three hundred workers. Out of these, 83% are connected to the management of municipal waste packaging (selective collection and sorting), 15% are connected to the management of non-municipal packaging waste and only 2% are connected to the Sociedade Ponto Verde (SPV, green dot society in English) – the management entity responsible for SIGRE.In general terms, the results obtained provide quantitative support to the EEA (2011) suggestion that moving up the waste hierarchy – from landfilling to recycling – creates jobs and boosts the economy.     

Obstruction of biodiversity conservation by minimum patch size criteria

Minimum patch size criteria for habitat protection reflect the conservation principle that a single large (SL) patch of habitat has higher biodiversity than several small (SS) patches of the same total area (SL > SS). Nonetheless, this principle is often incorrect, and biodiversity conservation requires placing more emphasis on protection of large numbers of small patches (SS > SL). We used a global database reporting the abundances of species across hundreds of patches to assess the SL > SS principle in systems where small patches are much smaller than the typical minimum patch size criteria applied for biodiversity conservation (i.e., ∼85% of patches <100 ha). The 76 metacommunities we examined included 4401 species in 1190 patches. From each metacommunity, we resampled species–area accumulation curves to evaluate how biodiversity responded to habitat existing as a few large patches or as many small patches. Counter to the SL > SS principle and consistent with previous syntheses, species richness accumulated more rapidly when adding several small patches (45.2% SS > SL vs. 19.9% SL > SS) to reach the same cumulative area, even for the very small patches in our data set. Responses of taxa to habitat fragmentation differed, which suggests that when a given total area of habitat is to be protected, overall biodiversity conservation will be most effective if that habitat is composed of as many small patches as possible, plus a few large ones. Because minimum patch size criteria often require larger patches than the small patches we examined, our results suggest that such criteria hinder efforts to protect biodiversity.     

中国城市化发展阶段与CO2排放的关系研究

目前节能减排已经成为中国“十二五”规划面临的主要任务之一,相关部门在进行决策时不能不考虑城市发展水平与CO2排放的关系.通过协整理论及修正误差模型分析结果表明,由于中国经历着经济转轨和社会转型,虽然1949-2007年城市化与CO2排放并不存在长期均衡关系,但改革开放前后城市化和CO2排放量都呈现出长期稳定的比例关系,即CO2排放随着城市化水平的提高而不断提高,且改革开放前后城市化水平对CO2排放影响存在差异.另外,尽管从短期来看,CO2排放不受当年城市化变动的影响,但从长期来看,不论改革开放前还是改革开放以后,城市化与CO2排放之间具有长期的稳定关系.城市化对CO2排放的影响存在一定的滞后性.因此,相关政府部门在进行决算时不能脱离城市化发展阶段,即要考虑短期影响,更要在战略高度进行长期规划,可通过把握城市化的进程来控制CO2排放增长的速度.     

Managing conflicts between economic activities and threatened migratory marine species toward creating a multiobjective blue economy

Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement‐based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species’ 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of <100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine >50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.     

Unignited High-Pressure Methane Jet Impinging a Pipe Rack: Practical Tools for Risk Assessment

Although the diffusion of its storage and transport under liquefied conditions, nowadays it is common to have methane in gaseous form in several industrial applications. This leads to safety implications to be considered: hazards are linked to both the high-pressure at which the gas is kept and to its flammability. Scenarios where flammable jets impact an obstacle are of paramount importance because of their possible occurrence. Following a numerical approach, literature shows up that their assessment can be reliably performed by means of only Computational Fluid Dynamics tools. However, despite the improvements of computing power, Computational Fluid Dynamics costs still limit its use in daily risk analysts’ activities. Therefore, considering an accidental jet-obstacle scenario of industrial interest, the present work investigates how a pipe rack can influence the development of a high-pressure methane jet. Based on a Computational Fluid Dynamics analysis, main achievements of this work are a simple criterion able to identify the situations where the pipe rack does not influence the high-pressure methane jet behavior, therefore allowing to identify the scenarios where simpler models can be used (i.e., analytical correlations known for the free jet situation), and, if present, a simple analytical relationship that roughly predicts the influence of the pipe rack without the need of performing complex Computational Fluid Dynamics simulations.