| 1. |
- Benaiges-Fernandez, Robert, et al.
(författare)
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Dissimilatory bioreduction of iron(III) oxides by Shewanella loihica under marine sediment conditions
- 2019
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Ingår i: Marine Environmental Research. - : Elsevier. - 0141-1136 .- 1879-0291. ; 151
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Tidskriftsartikel (refereegranskat)abstract
- Shewanella is a genus of marine bacteria capable of dissimilatory iron reduction (DIR). In the context of deep-sea mining activities or submarine mine tailings disposal, dissimilatory iron reducing bacteria may play an important role in biogeochemical reactions concerning iron oxides placed on the sea bed. In this study, batch experiments were performed to evaluate the capacity of Shewanella loihica PV-4 to bioreduce different iron oxides (ferrihydrite, magnetite, goethite and hematite) under conditions similar to those in anaerobic sea sediments. Results showed that bioreduction of structural Fe(III) via oxidation of labile organic matter occurred in all these iron oxides. Based on the aqueous Fe (II) released, derived Fe(II)/acetate ratios and bioreduction coefficients seem to be only up to about 4% of the theoretical ones, considering the ideal stoichiometry of the reaction. A loss of aqueous Fe (II) was caused by adsorption and mineral transformation processes. Scanning electron microscope images showed that Shewanella lohica was attached to the Fe(III)-oxide surfaces during bioreduction. Our findings suggest that DIR of Fe(III) oxides from mine waste placed in marine environments could result in adverse ecological impacts such as liberation of trace metals in the environment.
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| 2. |
- Enflo, Kerstin, et al.
(författare)
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Transportation and regional inequality: the impact of railways in the Nordic countries, 1860–1960
- 2018
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Ingår i: Journal of Historical Geography. - : Elsevier BV. - 0305-7488. ; 62, s. 51-70
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Tidskriftsartikel (refereegranskat)abstract
- Before industrialisation the Nordic countries (Denmark, Finland, Norway and Sweden) were part of Europe's poor periphery, but over the last century these countries have become some of the richest in the world. This article analyses the origins of Nordic growth from the late nineteenth century, focusing on a previously neglected topic: the role of transportation. We argue that transportation, and most notably large investments in railways, played a key role in Nordic industrialisation. Railways made the exploitation and exportation of natural resources possible in what had previously been isolated areas and helped fuel a process of rural-based industrialisation. By creating conditions that favoured migration towards previously scarcely populated, but economically booming areas, Nordic industrialisation was paralleled by a reduction in regional inequality as measured in per capita GDP. We assert that railways were built before local population growth and helped shape the economic landscape of the entire region. We illustrate these points using maps based on Historical Geographic Information Systems (HGIS) highlighting railways, regional GDP and population densities from the mid nineteenth century until 1960.
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