The influence of hearing loss on transport safety and mobility

Purpose: To examine how road users with different degree of hearing loss experience safety and mobility in transport situations, compared to road users with normal hearing.Methods: A questionnaire ... Document type: Articl

Die Wertschöpfungskette des Handels im Zeitalter des Electronic Commerce - Was eingetreten ist und was dem Handel noch bevorsteht

Vor zehn Jahren untersuchten Albers/Peters (1997) die Einflüsse des eCommerce auf die Wertschöpfungskette im Handel. Seit dieser Zeit ist die Entwicklung weiter vorangeschritten. Neben der erwarteten Entbündelung von Handelsaktivitäten wurde seitdem vor allem die Unterstützung des Kaufprozesses der Konsumenten von branchenfremden Infomediären übernommen. Neue Technologien, Anwendungen und ein geändertes Konsumentenverhalten werden die Effekte noch verstärken und stellen alle heutigen Marktteilnehmer, sowohl Infomediäre als auch Stationär-, Online- und Multichannel-Händler, zukünftig vor noch größere Herausforderungen. -- Ten years ago Albers/Peters (1997) analyzed the impact of eCommerce on the retail value chain. Since then major change has taken place. Apart from the expected unbundling of several retail activities along the value chain, especially the consumer buying process has been taken online and increasingly supported by new infomediaries. Those new infomediaries have taken the retailer's traditional ground. New technologies, applications and a changing consumer behavior will confront today's market players, infomediaries as well as offline-, online- and multichannelretailers, with even bigger challenges.eCommerce,Handel,Strategie,Multichannel,Wertschöpfungskette,Konsumentenverhalten

Grainyhead-like 2 is required for morphological integrity of mouse embryonic stem cells and orderly formation of inner ear-like organoids

Mutations in the transcription factor gene grainyhead-like 2 (GRHL2) are associated with progressive non-syndromic sensorineural deafness autosomal dominant type 28 (DFNA28) in humans. Since complete loss of Grhl2 is lethal in mouse embryos, we studied its role during inner ear pathology and hearing loss in vitro. To this end, we generated different homozygous deletions to knockout Grhl2 in mouse embryonic stem cells (Grhl2-KO ESCs), including some mimicking naturally occurring truncations in the dimerisation domain related to human DFNA28. Under naïve culture conditions, Grhl2-KO cells in suspension were more heterogenous in size and larger than wild-type controls. Adherent Grhl2-KO cells were also larger, with a less uniform shape, flattened, less circular morphology, forming loose monolayer colonies with poorly defined edges. These changes correlated with lower expression of epithelial cadherin Cdh1 but no changes in tight junction markers (Ocln, Tjp2) or other Grhl isoforms (Grhl1, Grhl3). Clonogenicity from single cells, proliferation rates of cell populations and proliferation markers were reduced in Grhl2-KO ESCs. We next induced stepwise directed differentiation of Grhl2-KO ESCs along an otic pathway, giving rise to three-dimensional inner ear-like organoids (IELOs). Quantitative morphometry revealed that Grhl2-KO cells initially formed larger IELOs with a less compacted structure, more eccentric shape and increased surface area. These morphological changes persisted for up to one week. They were partially rescued by forced cell aggregation and fully restored by stably overexpressing exogenous Grhl2 in Grhl2-KO ESCs, indicating that Grhl2 alters cell-cell interactions. On day 8, aggregates were transferred into minimal maturation medium to allow self-guided organogenesis for another two weeks. During this period, Grhl2-KO cells and wild-type controls developed similarly, expressing neural, neuronal and sensory hair cell markers, while maintaining their initial differences in size and shape. In summary, Grhl2 is required for morphological maintenance of ESCs and orderly formation of IELOs, consistent with an essential role in organising epithelial integrity during inner ear development. Our findings validate quantitative morphometry as a useful, non-invasive screening method for molecular phenotyping of candidate mutations during organoid development

Grainyhead-like 2 is required for morphological integrity of mouse embryonic stem cells and orderly formation of inner ear-like organoids

Mutations in the transcription factor gene grainyhead-like 2 (GRHL2) are associated with progressive non-syndromic sensorineural deafness autosomal dominant type 28 (DFNA28) in humans. Since complete loss of Grhl2 is lethal in mouse embryos, we studied its role during inner ear pathology and hearing loss in vitro. To this end, we generated different homozygous deletions to knockout Grhl2 in mouse embryonic stem cells (Grhl2-KO ESCs), including some mimicking naturally occurring truncations in the dimerisation domain related to human DFNA28. Under naïve culture conditions, Grhl2-KO cells in suspension were more heterogenous in size and larger than wild-type controls. Adherent Grhl2-KO cells were also larger, with a less uniform shape, flattened, less circular morphology, forming loose monolayer colonies with poorly defined edges. These changes correlated with lower expression of epithelial cadherin Cdh1 but no changes in tight junction markers (Ocln, Tjp2) or other Grhl isoforms (Grhl1, Grhl3). Clonogenicity from single cells, proliferation rates of cell populations and proliferation markers were reduced in Grhl2-KO ESCs. We next induced stepwise directed differentiation of Grhl2-KO ESCs along an otic pathway, giving rise to three-dimensional inner ear-like organoids (IELOs). Quantitative morphometry revealed that Grhl2-KO cells initially formed larger IELOs with a less compacted structure, more eccentric shape and increased surface area. These morphological changes persisted for up to one week. They were partially rescued by forced cell aggregation and fully restored by stably overexpressing exogenous Grhl2 in Grhl2-KO ESCs, indicating that Grhl2 alters cell-cell interactions. On day 8, aggregates were transferred into minimal maturation medium to allow self-guided organogenesis for another two weeks. During this period, Grhl2-KO cells and wild-type controls developed similarly, expressing neural, neuronal and sensory hair cell markers, while maintaining their initial differences in size and shape. In summary, Grhl2 is required for morphological maintenance of ESCs and orderly formation of IELOs, consistent with an essential role in organising epithelial integrity during inner ear development. Our findings validate quantitative morphometry as a useful, non-invasive screening method for molecular phenotyping of candidate mutations during organoid development

Bestimmung mikrobieller Aktivität in Böden mittels IR – Thermographie

Die mikrobielle Aktivität in Böden wird in der Regel an abgeschlossenen Bodenproben anhand der Bodenatmung oder des Energieumsatzes erfasst (z.B. Respirometer, Kalorimeter). Diese Verfahren können jedoch nur punktuelle Aussagen zur mikrobiellen Aktivität, und damit z.B. zu Belastungen von Böden mit Umwelt-chemikalien liefern. In diesem Beitrag stellen wir ein Verfahren vor, das die Bestimmung flächenhafter mikrobieller Aktivität anhand von räumlich und zeitlich hoch aufgelöster Infrarot(IR)- Thermographie erlaubt. Erste Versuche zeigen, dass dieses Verfahren generell möglich ist. Mögliche andere Einflussgrößen für die Oberflächentemperatur, wie z.B. Evaporation, müssen ausgeschlossen oder bei der Auswertung berücksichtigt werden

Bestimmung der Evaporationsrate von Bodenoberflächen mittels Thermographie

Die aktuellen Evaporationsraten von Bodenoberflächen lassen sich durch aufeinander folgende Wägungen bestimmen. Diese Methode hat zwei Nachteile (i) sie ist nur an kontrollierten Bodenmonolithen auf der Labor- und Lysimeterskala möglich und (ii) sie liefert nur ein über die gesamte Bodenoberfläche integriertes Signal, es gibt somit keine Information über eine räumlich variable Evaporationsrate. In diesem Beitrag stellen wir ein Verfahren vor, das die Evaporationsrate mittels Thermographie räumlich und zeitlich hochaufgelöst ermittelt. Ein erster Versuch zeigt, dass dieses Verfahren prinzipiell anwendbar ist. Allerdings spielen die Substrateigenschaften eine große Rolle, sodass eine jeweilige Kalibrierung notwendig ist

Multi Mode Interferometer for Guided Matter Waves

We describe the fundamental features of an interferometer for guided matter waves based on Y-beam splitters and show that, in a quasi two-dimensional regime, such a device exhibits high contrast fringes even in a multi mode regime and fed from a thermal source.Comment: Final version (accepted to PRL

Suppression of electrical breakdown phenomena in liquid TriMethyl Bismuth based ionization detectors

Organometallic liquids provide good properties for ionization detectors. TriMethyl Bismuth (TMBi) has been proposed as a detector medium with charge and Cherenkov photon readout for Positron Emission Tomography. In this work, we present studies for the handling of TMBi at different electric fields and under different environmental conditions to find applicable configurations for the suppression of electrical breakdowns in TMBi at room temperature. A simple glass cell with two electrodes filled with TMBi was constructed and tested under different operation conditions. Working at the vapour pressure of TMBi at room temperature of about 40 mbar and electric fields of up to 20 kV/cm in presence of a small oxygen contamination we found the formation of a discharge channel in the liquid and a steady increase in the current. Further reduction of pressure by pumping caused the TMBi to boil and a spontaneous combustion. Eliminating the oxygen contamination led the TMBi under the same condition to only decompose. When operating the setup under an argon atmosphere of 1 bar we did not observe breakdowns of the electrical potential up to field strengths of 20 kV/cm. Still, in presence of a small oxygen contamination fluctuating currents in the nA range were observed, but no decomposition or combustion. We conclude from our experiments that TMBi at room temperature in a pure argon atmosphere of 1 bar remains stable against electrical breakdown at least up to electric field strengths of 20 kV/cm, presumably because the formation of gaseous TMBi was prevented.Comment: 14 page, 8 figure