Annals of Regional Science | Year: 2010
This article report findings from a new dataset that consists of productivity and employment variables from 89 Western European regions and 51 American states and districts from 1950 to 2000. Distribution dynamics is used to investigate convergence in labor productivity, Gross Value Added (GVA) per capita, and employment ratios. Main findings are that European labor productivity and GVA per capita have converged more or less continuously since 1950, but that the European employment ratios show divergence after 1970. Compared to US, the European regions have faced an employment-productivity trade-off since the 1970s. This trade-off appears to be related to country-specific factors. © 2009 Springer-Verlag.
Applied Geochemistry | Year: 2015
Environmental assessments are conducted prior to mineral development at proposed mining operations. Among the objectives of these assessments is prediction of solute release from mine wastes projected to be generated by the proposed mining and associated operations. This paper provides guidance to those engaged in these assessments and, in more detail, provides insights on solid-phase characterization and application of kinetic test results for predicting solute release from waste rock. The logic guiding the process is consistent with general model construction practices and recent publications. Baseline conditions at the proposed site are determined and a detailed operational plan is developed and imposed upon the site. Block modeling of the mine geology is conducted to identify the mineral assemblages present, their masses and compositional variations. This information is used to select samples, representative of waste rock to be generated, that will be analyzed and tested to describe characteristics influencing waste rock drainage quality. The characterization results are used to select samples for laboratory dissolution testing (kinetic tests). These tests provide empirical data on dissolution of the various mineral assemblages present as waste rock. The data generated are used, in conjunction with environmental conditions, the proposed method of mine waste storage, and scientific and technical principles, to estimate solute release rates for the operational scale waste rock. Common concerns regarding waste rock are generation of acidic drainage and release of heavy metals and sulfate. Key solid phases in the assessments are those that dissolve to release acid and sulfate (iron sulfides, soluble iron sulfates, hydrated iron-sulfate minerals, minerals of the alunite-jarosite group), those that dissolve to neutralize acid (calcium and magnesium carbonates, silicate minerals), and those that release trace metals (trace metal sulfides, hydrated trace metal-sulfate minerals). Conventional mineralogic, petrographic, and geochemical analyses generally can be used to determine the quantities of these minerals present and to describe characteristics that influence their dissolution. A key solid-phase characteristic is the mineral surface area exposed for reaction, which is influenced by mode of occurrence (included, interstitial, liberated) and the extent of mineral surface coating. Short-term dissolution tests can estimate the extent of hydrated sulfate minerals present. Longer term dissolution tests are necessary to describe the dependence of drainage pH and solute release rates on solid-phase variation. The extensive data compiled from baseline pre-development definition, the operational plan, solid-phase characterization, and dissolution testing are ultimately synthesized by means of a modeling exercise requiring considerable technical and scientific expertise. The predicted rates (model outputs) are expressed as probability distributions to allow assessment of risk. This exercise must be technically defensible and transparent so that regulators can confidently assess the results and evaluate the operational plan proposed. Technical and non-technical challenges involved in implementing such programs are identified to benefit management planning for both industry and government. © 2015.
Gossling S.,Box |
Gossling S.,Linnaeus University
Journal of Transport Geography | Year: 2013
Mobility growth poses considerable challenges to city planners around the world, as it entails problems of congestion, air pollution, and accidents. Many cities have thus sought to increase the share of sustainable transport, and specifically travel by bicycle. However, it appears that measures to foster cycling are often implemented on an ad hoc basis, lacking strategic focus and a more profound understanding of bicycle cultures. New insights can be gained from Copenhagen, Denmark, a selfdeclared City of Cyclists that has made considerable progress towards increasing the share of travel by bicycle, with the political goal to become the "world's best city for bicycling". In this article, the success, reproducibility and limitations of the Copenhagen bicycle strategy are discussed in an urban transport transitions framework, based on a content- and discourse analysis of the city's official documents to assess the respective role of market-based, command-and-control, and soft policy measures in encouraging bicycling. Results suggest that soft policies, integrated with command-and-control measures, and the consideration of bicyclist expectations and concerns with regard to perceptions of safety, speed and comfort have been key in achieving high bicycle trip shares. Integrating these in comprehensive planning frameworks appears to be an approach that is more likely to foster bicycle cultures that can result in urban transport transitions. © 2013 Elsevier Ltd.
Forest Ecology and Management | Year: 2010
Fires are considered the most important disturbance regime in many ecosystems, including boreal forest. Fires usually reduce the abundances of soil living animals, but the duration of the fire effect and the recovery rate of soil fauna communities after fire are poorly understood. The species-rich group of microarthropods (collembolans, mites and proturans) constitutes an important part of the soil food-web, contributing to important ecosystem services like decomposition and nutrient mobilization. Recovery rates of microarthropods after fire reported in the literature differ considerable between sites and studies. Here, I examine if variation in fire severity can explain part of the variation in recovery of microarthropods after fire observed among studies. To do so, I have chosen studies done in boreal forests and in which the post-fire situation was described in such a way that fire severity (depth of burn) could be estimated. I also selected studies that used real abundance data and that sampled for animals for at least 2 years after fire. More severe fires were more determinal to soil fauna. Collembola (springtails) recovered within a few years at sites burnt with low severity, but the time frame in most studies (2-5 years) was too short to detect recovery at moderate or severely burnt sites. For mesostigmata and oribatida the recovery patterns were harder to interpret. I argue that fire severity is the most important factor explaining differences in microarthropod responses to fire, and that this is probably true also for other soil dwelling organisms. Because fire severity is often not taken into account when the effects of fire are investigated, generalizations about fire effects are hard to make. © 2010 Elsevier B.V. All rights reserved.
Andersson D.I.,Box |
Drug Resistance Updates | Year: 2012
Human use of antimicrobials in the clinic, community and agricultural systems has driven selection for resistance in bacteria. Resistance can be selected at antibiotic concentrations that are either lethal or non-lethal, and here we argue that selection and enrichment for antibiotic resistant bacteria is often a consequence of weak, non-lethal selective pressures - caused by low levels of antibiotics - that operates on small differences in relative bacterial fitness. Such conditions may occur during antibiotic therapy or in anthropogenically drug-polluted natural environments. Non-lethal selection increases rates of mutant appearance and promotes enrichment of highly fit mutants and stable mutators. © 2012 Elsevier Ltd. All rights reserved.