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Singer J.,ETH Zurich | Diehl T.,ETH Zurich | Husen S.,ETH Zurich | Husen S.,Kantonales Laboratorium Basel Stadt | And 2 more authors.
Earth and Planetary Science Letters | Year: 2014

Beneath the northern foreland of the Central Alps deep crustal earthquakes up to magnitude 4 regularly occur in the continental lithosphere. At 20 km to 30 km depths, where most of these earthquakes are located, temperatures above 450 °C are expected. This leads to a more ductile rheology of the lower continental crust. To better understand occurrence and underlying processes of these unusual earthquakes, we homogenize and improve hypocenter locations of events in the period 1984 to 2012 using a high-precision multi-phase earthquake location method in combination with a reliable three-dimensional P-wave velocity model of the crust and uppermost mantle. With the new approach, the average uncertainty in focal depth of well-locatable earthquakes is less than ±1 km. The homogeneously relocated hypocenters suggest a relatively uniform depth distribution throughout the lower crust. In agreement with previous studies, seismicity is entirely restricted to the crust and no evidence for seismicity in the mantle lithosphere beneath the northern Central Alpine foreland was found. The geographical distribution of lower crustal earthquakes in the foreland correlates remarkably well with the lateral extent of the European slab beneath the Central Alps where it is still attached to the European lithosphere. In addition, the directions of extensional axes derived from focal mechanisms of the deep crustal earthquakes are predominantly parallel to the Alpine front. This consistency of extensional axes can be interpreted as the result of the transferred buoyancy force of the lower crust in the subduction, transformed to a compressional force in the foreland perpendicular to the Alpine front. Existing 2-D thermo-mechanical models predict such viscous bending and stress transfer to the foreland. In our proposed model, the anomalously deep crustal seismicity is driven by stresses transferred into the foreland interrelated with the exhumation of the crust form the orogenic root caused by the rollback of the European lithosphere. © 2014 The Authors. Source


Baumgartner A.,Federal office of Public Health of Fribourg | Gautsch S.,Kantonales Laboratorium Basel Stadt
Journal fur Verbraucherschutz und Lebensmittelsicherheit | Year: 2011

In a broad market survey, 145 samples of tattoo- and permanent make-up pigments were bacteriologically analysed. The pigments originated from 39 unopened vials and 106 opened vials in use. The samples were collected from 33 tattoo shops and 22 beauty studios and the analyses were effected by direct plating on four agar media and by enrichment in a non-selective broth. None of the used media could detect all contaminated samples. The best performance was obtained with sheep blood agar (BA), which detected bacterial counts in 7 of 39 (17.9 %) of unopened vials and in 22 of 106 (20.8 %) opened vials. In 12 of 145 samples (8.3 %), bacterial growth was observed in the enrichment broth but not on sheep BA. In most cases, contaminations were in a low range of 101-102 cfu / mL. Counts in the range of 103-108 cfu / mL were registered in only four samples that were from different tattoo shops and from different manufacturers. Among the 31 bacterial species that were detected in the examined pigments, 20 (64.5 %) belonged to Gram positive rods or to Bacillus or related genera, respectively, 8 (25.8 %) to Gram positive cocci and only 3 (9.7 %) to Gram negative rods. Bacterial agents, known to cause dermal infections, were never detected. Based on the obtained data, a simple risk assessment was made, and microbiological criteria for future legal regulation proposed. © 2010 Springer Basel AG. Source


Laux P.,German Federal Institute for Risk Assessment | Tralau T.,German Federal Institute for Risk Assessment | Tentschert J.,German Federal Institute for Risk Assessment | Blume A.,German Federal Institute for Risk Assessment | And 22 more authors.
The Lancet | Year: 2016

Summary Long perceived as a form of exotic self-expression in some social fringe groups, tattoos have left their maverick image behind and become mainstream, particularly for young people. Historically, tattoo-related health and safety regulations have focused on rules of hygiene and prevention of infections. Meanwhile, the increasing popularity of tattooing has led to the development of many new colours, allowing tattoos to be more spectacular than ever before. However, little is known about the toxicological risks of the ingredients used. For risk assessment, safe intradermal application of these pigments needs data for toxicity and biokinetics and increased knowledge about the removal of tattoos. Other concerns are the potential for phototoxicity, substance migration, and the possible metabolic conversion of tattoo ink ingredients into toxic substances. Similar considerations apply to cleavage products that are formed during laser-assisted tattoo removal. In this Review, we summarise the issues of concern, putting them into context, and provide perspectives for the assessment of the acute and chronic health effects associated with tattooing. © 2016 Elsevier Ltd. Source


Abgottspon H.,University of Zurich | Stephan R.,University of Zurich | Bagutti C.,Kantonales Laboratorium Basel Stadt | Brodmann P.,Kantonales Laboratorium Basel Stadt | And 2 more authors.
Journal of Food Protection | Year: 2014

A worrisome phenomenon is the progressive global spread of Enterobacteriaceae in poultry and chicken meat expressing plasmid-mediated enzymes that inactivate β-lactam antibiotics, suggesting that the food chain might play a role in the epidemiology and the transmission of extended-spectrum cephalosporin-resistant Enterobacteriaceae to humans. The aim of the present study was to further characterize 24 extended-spectrum cephalosporin-resistant Enterobacteriaceae isolated from domestic and imported poultry meat by antibiotic susceptibility testing, identification of the blaESBL/blapAmpC genes, conjugation mating experiments and determination of plasmid incompatibility types, multilocus sequence typing, and analysis of the Escherichia coli phylogenetic groups. On account of their resistance patterns, 21 of the total 24 isolates were classified as multidrug resistant. Eleven isolates carried a blaCMY-2 gene, whereas 13 isolates harbored a blaCTX-M-1 gene. All isolates harbored plasmids that were assigned to 8 of the 18 described plasmid incompatibility groups, the most frequent of which were IncI1, IncFIB, IncB/O, and IncFrepB. The blaESBL/blapAmpC genes were harbored mainly by transferable IncI1 and IncB/O plasmids. Multilocus sequence typing as well as E. coli phylogenetic group typing revealed a high heterogenicity even among different isolates of the same sample. © International Association for Food Protection. Source

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