Small-scale opencast mining: an important research field for anthropogenic geomorphology

Artisanal and small-scale mining (A&SM) is a growing economic sector in many third-world countries. This review focuses on anthropo-geomorphic factors and processes associated with small-scale opencast mining (SSOM), a form of A&SM in which near-surface ores are extracted by removing relatively thin covers of soil, bedrock or sediments. Being widespread and commonly conducted without proper planning and beyond the control of local authorities, this form of mining has potentially large impacts on landforms and landscape dynamics, often resulting in drastic consequences for the local environment and agriculture. SSOM should be regarded as a component of anthropogenic geomorphology because it involves the role of humans in creating landforms and modifying the operation of natural geomorphological processes, such as weathering, erosion, transport and deposition. By initiating new and modifying natural geomorphic processes, SSOM causes and/or accelerates geomorphic processes, resulting in various forms of land degradation. While the direct geomorphic impact of SSOM is in general easily discernible and leads to characteristic features, such as excavated pits and overburden spoil heaps, many secondary impacts are attributed to geomorphic processes triggered in the wake of the primary mining-induced landscape alterations. The magnitude of such secondary implications may well extend beyond the actual mining areas, but these effects have not been thoroughly addressed in the research so far. This review summarizes the known studies on the geomorphic impacts of SSOM operations and highlights common geomorphic processes and landforms associated with this type of anthropogenic activity, thus establishing a starting point for further in-depth research

Euro+Med-Checklist Notulae, 2

This is the second of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. The instalment deals with the families Amaranthaceae, Boraginaceae, Caryophyllaceae, Compositae, Cruciferae, Labiatae, Orobanchaceae, Papaveraceae, Portulacaceae, Ranunculaceae, Vitaceae; Amaryllidaceae, Araceae, Cyperaceae, Gramineae and Potamogetonaceae. It includes new country and area records, taxonomic and distributional considerations for taxa in Amaranthus, Bothriochloa, Carex, Consolida, Corrigiola, Cyperus, Festuca, Fumaria, Heliotropium, Jacobaea, Klasea, Lobularia, Nigella, Orobanche, Papaver, Phelipanche, Pistia, Portulaca, Potamogeton, Spergula, Sternbergia, Teucrium and Vitis, and the validation of names in Amaranthus, Festuca and Spergula

Euro+Med-Checklist Notulae, 14

This is the fourteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Apocynaceae, Compositae, Crassulaceae, Cyperaceae, Euphorbiaceae, Gramineae, Leguminosae, Nyctaginaceae, Onagraceae, Orobanchaceae, Rubiaceae, Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Acalypha, Bupleurum, Carex, Datura, Epilobium, Eragrostis, Galium, Leontodon, Mirabilis, Nerium, Orobanche, Phelipanche, Rhinanthus, Saccharum, Sedum, Trifolium, Tripleurospermum and Willemetia

Euro+Med-Checklist Notulae, 15

This is the fifteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Amaranthaceae, Amaryllidaceae, Cactaceae, Campanulaceae, Caprifoliaceae, Caryophyllaceae, Chenopodiaceae, Compositae, Cyperaceae, Dipsacaceae, Leguminosae, Lentibulariaceae, Molluginaceae, Montiaceae, Onagraceae, Orobanchaceae, Pinaceae, Plantaginaceae, Polygalaceae, Rosaceae, Rubiaceae, Umbelliferae and Violaceae. It includes new country and area records and taxonomic and distributional considerations for taxa in Acacia, Amaranthus, Bupleurum, Campanula, Carex, Claytonia, Dysphania, Epilobium, Erigeron, Galium, Gelasia, Hieracium, Lathyrus, Lomelosia, Lonicera, Mollugo, Nothoscordum, Opuntia, Orobanche, Picea, Plantago, Polycarpon, Polygala, Rubus, Scorzoneroides, Utricularia, Veronica, Vicia and Viola, and a correction to a previous notula for Trifolium pachycalyx in Greece

Euro+Med-Checklist Notulae, 16

This is the sixteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Caryophyllaceae, Compositae, Euphorbiaceae, Gramineae, Iridaceae, Leguminosae, Malvaceae, Portulacaceae, Rosaceae, Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Bromus, Datura, Daucus, Erigeron, Euphorbia, Iris, Minuartia, Paspalum, Portulaca, Sida and Vigna, and a new combination in Prunus

UNDERSTANDING THE ROLE OF SOCIAL PRESENCE IN CROWDFUNDING: EVIDENCE FROM LEADING U.S. AND GERMAN PLATFORMS

As a novel opportunity to acquire capital from the masses, crowdfunding has attracted great attention in academia and practice. So far, little is known about the factors that promote the success of crowdfunding projects, however. In this paper, we examine in how far the social presence perceived on a project’s website influences the success of the respective crowdfunding project. Based on a data-driven analysis of 2.000 project websites from the largest crowdfunding platforms in the U.S. and Germany, we show that the perceived social presence has a significant influence on the success of crowdfunding projects. The obtained results indicate that using socially rich pictures and a socially rich description in the project presentation positively affects the success of a crowdfunding project. A socially rich profile page of the founder(s) in contrast appears to have a rather limited effect. The success of crowdfunding projects seems to be dependent on the participation behavior of the founder, however. Our results indicate that having backed other projects positively influences the success of one’s own initiative. The number of answered comments might have a negative effect on the success of the initiative, though

A simple and versatile analytical approach for planar metamaterials

We present an analytical model which permits the calculation of effective material parameters for planar metamaterials consisting of arbitrary unit cells (metaatoms) formed by a set of straight wire sections of potentially different shape. The model takes advantage of resonant electric dipole oscillations in the wires and their mutual coupling. The pertinent form of the metaatom determines the actual coupling features. This procedure represents a kind of building block model for quite different metaatoms. Based on the parameters describing the individual dipole oscillations and their mutual coupling the entire effective metamaterial tensor can be determined. By knowing these parameters for a certain metaatom it can be systematically modified to create the desired features. Performing such modifications effective material properties as well as the far field intensities remain predictable. As an example the model is applied to reveal the occurrence of optical activity if the split ring resonator metaatom is modified to L- or S-shaped metaatoms.Comment: 5 figures, 1 tabl

Dye Tracer Visualization of Infiltration Patterns in Soils on Relict Charcoal Hearths

Anthropogenically modified soils are often characterized by a high heterogeneity of substrates and show unique patterns of water infiltration. Such effects are not limited to intensively used or disturbed agricultural and technogenic soils, but can also occur as legacies of former land use in forested areas. The remains of historic charcoal hearths represent a widespread legacy of historic land use. Soils at relict charcoal hearths (RCHs) are most prominently altered by the deposition of a layer of charcoal-rich substrate on top of the natural soil surface. The presence of such a technogenic layer can considerably influence infiltration and soil wetness patterns on the sites. This study describes the spatial patterns of infiltration and soil wetness at charcoal hearth sites compared with undisturbed sandy forest soils for a historic charcoal production area north of Cottbus, Germany. We characterized six plots on RCH and reference soils under pine, oak, and mixed forest by visualizing preferential flow patterns of infiltrating water in dye tracer experiments. Additionally, we characterized bulk density, soil organic matter (SOM) contents and water repellency, using water drop penetration time (wdpt) tests, of the RCH and reference soil horizons. The results reflect that the persistence of water repellency of both the technogenic substrates and the natural topsoils is extremely high under dry conditions, but is drastically reduced after wet antecedent conditions. The dye tracer experiments reflect increased preferential flow on the RCHs for dry soil conditions, for which infiltration is limited to very few flow paths in the technogenic substrate layer. Differences between RCH and reference soils are less clear for higher antecedent soil wetness, for which the results indicate more uniform wetting of the technogenic substrates. We conclude that the structural properties of the additional technogenic substrate layer of RCHs have characteristic effects on water infiltration, causing a high temporal variation of preferential flow in relation to antecedent soil moisture conditions. These effects can result in high heterogeneity of soil moisture for dry conditions, and generally in a high temporal variation of soil wetness in RCHs soils

The GeneOptimizer Algorithm: using a sliding window approach to cope with the vast sequence space in multiparameter DNA sequence optimization

One of the main advantages of de novo gene synthesis is the fact that it frees the researcher from any limitations imposed by the use of natural templates. To make the most out of this opportunity, efficient algorithms are needed to calculate a coding sequence, combining different requirements, such as adapted codon usage or avoidance of restriction sites, in the best possible way. We present an algorithm where a “variation window” covering several amino acid positions slides along the coding sequence. Candidate sequences are built comprising the already optimized part of the complete sequence and all possible combinations of synonymous codons representing the amino acids within the window. The candidate sequences are assessed with a quality function, and the first codon of the best candidates’ variation window is fixed. Subsequently the window is shifted by one codon position. As an example of a freely accessible software implementing the algorithm, we present the Mr. Gene web-application. Additionally two experimental applications of the algorithm are shown