Contrasted dynamics of northern Labrador tree lines caused by climate change and migrational lag

The northern Québec-Labrador tree lines are the most climatically stressed tree ecosystems of eastern North America. In particular, white spruce (Picea glauca) tree line populations distributed between 56 degrees N and 58 degrees N and 61 degrees W and 66 degrees W show contrasted responses to recent changes in climate according to their geographic position relative to the Labrador Sea. Along the coast, the northernmost latitudinal and altitudinal tree lines responded positively to warming over the last 50 years with invading spruce several tens of meters above the current tree line. In contrast, white spruce tree lines across the wind-exposed Labrador plateau are located much higher in altitude and have receded a few tens of meters beginning around AD 1740-1750 and have not yet recovered. Whereas no field evidence of recent fire and insect damage was found, all inland tree line stands were progressively damaged likely due to mechanical defoliation of wind-exposed trees. Massive tree death in the 19th century caused a reduction in the number of seed-bearing trees, and declining tree lines were not replenished by seedlings. Recent warming reported for northern latitudes has not been strong enough to change the regressive tree line trajectory in interior Labrador. However, white spruce expansion above coastal tree line in the northernmost forest site in Labrador is in line with current climatic trends. It is hypothesized that the species is still advancing toward its potential tree line higher in altitude due to delayed postglacial migration. The slow advance of white spruce in northernmost coastal Labrador is likely caused by the rugged topography of the Torngat-Kaumajet-Kiglapait mountains.     

Social and environmental injustices in solid waste management in sub-Saharan Africa: a study of Kinshasa,the Democratic Republic of Congo

This paper investigates social and environmental injustices in solid waste management in Kinshasa, the capital of the Democratic Republic of Congo. The urban poor in most parts of Kinshasa bear a huge encumbrance of the solid waste burden and face multiple challenges associated with poor management of solid waste. This situation has resulted in poor and unhealthy living conditions for the majority of the urban residents. The problem of solid waste management in Kinshasa has further been compounded by rapid urbanisation which has occurred in the face of poor urban governance, civil conflict and weak institutional set-up. The combination of these challenges has resulted in increased overcrowding, poor sanitary conditions, lack of water and an unprecedented accumulation of solid waste which have triggered a myriad of urban problems. The worst affected are the poor urban who reside in locations that receive little or no socio-economic services from the Kinshasa Municipal authority. Using secondary data collected through a desk study, this paper argues that the poor solid waste situation in Kinshasa is not only a health risk, but also presents issues of both social and environmental injustices. These issues are analysed within the context of evolving arguments that focus on the need to develop a pro-poor approach in solid waste management that may present an opportunity for achieving both social and environmental justice for the urban poor in Kinshasa.     

石油烃厌氧生物降解代谢产物研究进展

石油烃厌氧生物降解代谢产物的分析对于石油烃厌氧降解机制的研究、功能微生物的筛选以及微生物活动的原位监测具有指示性作用.综述了近年来石油烃厌氧生物降解代谢产物的研究进展.石油烃厌氧降解的初始活化方式主要包括脱氢羟基化、加延胡索酸以及羧化等.其中,加延胡索酸是不同种类的微生物通常采用的代谢方式.同时,将代谢产物按照气体、无机离子和有机酸进行分类,并针对各类物质特别是瞬时性、低浓度的有机酸类产物常采用的分析方法进行归纳.通过实例强调了代谢产物作为潜在生物标记物的应用,并对石油烃厌氧降解代谢产物分析方法的发展提出展望.图3参58     

Biocatalytic dechlorination of hexachlorocyclohexane by immobilized bio-Pd in a pilot scale fluidized bed reactor

Lindane (??-hexachlorocyclohexane, ??-HCH) is a recalcitrant and toxic organochlorine insecticide. Due to its non-selective production process and widespread use, HCH isomers and their degradation products have been detected frequently in soils and groundwater. An innovative technology using microbial produced Pd(0) nanoparticles, i.e. bio-Pd, was developed to treat groundwater containing a mixture of HCHs and chlorobenzenes. In a first step, the groundwater was de-ironized and most of the chlorobenzenes were removed in a biological trickling filter. The ??g?L^?1 levels of HCHs and chlorobenzenes were removed in a second step by the bio-Pd-based technology. Therefore, a 200-L pilot scale reactor was developed with 100?mg?L^?1 bio-Pd encapsulated in alginate beads. Hydrogen gas was bubbled at the bottom of the reactor and served to charge the bio-Pd catalyst. The reactor influent contained 5.2???g?L^?1 HCHs and 51.1???g?L^?1 chlorobenzenes. During a test period of 10?days, 29% of the HCH isomers and 63% of the chlorobenzenes were removed applying a nominal hydraulic residence time of 4?h. These removal percentages could be increased to 75 and 68% by doubling the nominal hydraulic residence time to 8?h. This study demonstrated that biologically produced nanoparticles of Pd can be applied for the large-scale remediation of groundwater contaminated with HCHs.     

Lithium availability in the EU27 for battery-driven vehicles: The impact of recycling and substitution on the confrontation between supply and demand until2050

The adverse impacts of climate change are widely recognized as well as the importance of the mitigation of carbon dioxide (CO₂). Battery driven vehicles are expected to have a bright future, since GHG emissions can be reduced. Lithium-ion (Li-ion) batteries appear to be the most promising, due to their high energy density. Recently, the discussion concerning adequate lithium carbonate (Li₂CO₃) resources is resolved. The current challenge is the needed increase in flow rate of Li₂CO₃ into society to foresee in forecasted demand. This research determines ten factors which influence the availability of Li-ion batteries for the EU27 in the coming decades. They are used in a system dynamics analysis. The results of this research show that undersupply can be expected in the EU27 until 2045 somewhere between 0.5 Mt and 2.8 Mt. Substitution of Li₂CO₃ in other end-use markets and recycling can relieve the strain on Li₂CO₃ supply to some extent. In 2050, 20% of the vehicle fleet in the EU27 can be battery electric vehicles (BEVs). The lack of resources in the EU27 and the geographical distribution of lithium in politically sensitive areas suggest that the shares of lithium available for the EU27 will be less than assumed in this research. The increase in flow rate shows to be the bottle-neck for a transition to (partly) battery driven vehicles in the EU27, at least when Li-ion batteries are used. Focusing on large-scale application of BEVs with Li-ion batteries in order to substantially mitigate CO₂ emissions in transport is a futile campaign.     

Campomelic acampomelic dysplasia presenting with increased nuchal translucency in the first trimester

This is the first report of a fetus affected with campomelic acampomelic dysplasia presenting with increased nuchal translucency. Ultrasonography at 13 weeks of amenorrhea showed a nuchal translucency 5.6 mm thick. The karyotype performed on amniotic fluid cells was normal (46,XY). Ultrasonography at 22 weeks revealed a normal femoral length and female genitalia. A second amniocentesis was performed to confirm the karyotype and for dosage of steroid hormones. Testosterone dosage was low, corresponding to a female fetus. Ultrasonography at 32 weeks showed growth retardation of the long bones (<3rd centile) that were not curved. A severe malformation syndrome was suspected and the pregnancy was terminated at 33 weeks. The fetus displayed macrocephaly, facial dysmorphism and female external genitalia. X ray showed straight and thickened long bones, hypoplastic scapulae and moderate platyspondyly. In view of the association of sex reversal, hypoplasia of the scapulae, and the presence of straight long bones, campomelic acampomelic dysplasia was suspected and confirmed by the finding of a SOX9 mutation. This case shows the importance of a careful echographic survey in a fetus with a nuchal translucency > 4 mm, especially if there is discordance between phenotypic and genotypic sex, since growth retardation may occur later during the pregnancy. Copyright © 2004 John Wiley & Sons, Ltd.     

Lessons learnt from a participatory integrated assessment of greenhouse gas emission reduction options in firms

This article discusses an approach for identification and evaluation of short-term greenhouse gas (GHG) emission reduction options in firms. The approach is based on lessons learnt from a project using Participatory Integrated Assessment (PIA) and builds on the idea that effective public climate policy for firms requires options that have support from stakeholders and are practically feasible. Scenarios are used to provide a link with short-term policy developments and a model assists to communicate quantitative effects of options to participating stakeholders. Our approach can be seen as a first step towards a framework that meets the need for more systematic approaches to PIAs identifying effective public policies for short-term GHG emission reduction options in firms. In order to identify effective options for non-carbon dioxide GHG emission reductions, our approach has been applied to Dutch dairy farms, after which it has been refined. The case study suggests that our approach can provide balance between practical, context specific issues and scientific-theoretical aspects, thereby avoiding common pitfalls of participatory research projects to focus too much on either theory or practical issues.

Understanding nutrient build-up on urban road surfaces

This article discusses the outcomes of a research project on nutrients build-up on urban road surfaces.Nutrient build-up was investigated on road sites belonging to residential,industrial and commercial land use.Collected build-up samples were separated into five particle size ranges and were tested for total nitrogen (TN),total phosphorus (TP) and sub species of nutrients,namely,NO 2- ,NO 3- ,TKN and PO 43-.Multivariate analytical techniques were used to analyse the data and to develop detailed understanding on build- up.Data analysis revealed that the solids loads on urban road surfaces are highly influenced by factors such as land use,antecedent dry period and traffic volume.However,the nutrient build-up process was found to be independent of the type of land use.It was solely dependent on the particle size of solids build-up.Most of the nutrients were associated with the particle size range 150 μm.Therefore,the removal of particles below 150 μm from road surfaces is of importance for the removal of nitrogen and phosphorus from road surface solids build-up.It is also important to consider the difference in the composition of nitrogen and phosphorus build-up in the context of designing effective stormwater quality mitigation strategies.     

Elaboration of a Bio-Colored Material Based on Natural Dye and Polybutylene Succinate: Comparative Study with Colored Polylactic Acid

Journal of Polymers and the Environment - In the context of sustainable development and natural products valorization, new ecological materials enter a logic aimed at removing the causes of...