Submarine slope failure offshore Uruguay - first results

New geophysical acquired during cruise M78 with RV “Meteor” in 2009 reveal a large-scale slope failure complex. Positioned between 1800 and 3300 m water depth, the slope failure affected an area of at least 1200 km2. The failure is hosted in contouritic deposits. The morphology of the up 70 m high headwalls is underlain by a deeper reflector which we interpret as detachment. Listric faults positioned upslope these headwalls root in this detachment and are precursor of future failure at this location. The detachment correlates with a regional BSR mapped by Uruguayan colleagues. Cores recovered from 3 transects across the failure complex confirm that the acoustic transparent units are debrites. Sedimentological evidence in accordance with hydro-acoustic data indicate that debrites deposited downslope this failure complex are recent features on the slope

New hydroacoustic and core data reveal sediment transport patterns off Uruguay

Submarine landslides cause slope instabilities and might damage sea-floor infrastructure or even generate tsunami waves. Therefore it is of major importance to understand all processes related to gravity-driven mass wasting and slope stability at continental margins. New swath bathymetry and parametric echo-sounding data from the Uruguay shelf and slope north-east of the Rio de la Plata were collected during METEOR Cruise M78/3. These data are investigated in order to understand mass wasting and sedimentary transport processes at the margin off Uruguay. Large amounts of silty suspension freight are delivered from the Rio de la Plata estuary. These sediments are potentially unstable, leading to numerous mass transport units in the working area. Prominent features identified in the study include slide deposits, channels and several prominent escarpment structures. The situation is complicated by intensive slope parallel sediment transport due to strong contour currents. Our data indicate interaction between gravity-driven downslope transport and alongslope sediment transport. Contourite deposits in the headwall areas of mass wasting events suggest widespread weak layers at those deposits. The up to 70m-high headwalls, are focusing contour currents resulting in small alongslope channels. Future work will concentrate on the reconstruction of the geological/sedimentological history of the study area in order assess slope stability and sediment transport in greater detail

Die neuen Gewänder der Klassen: Klassifikationsstrategien in einer ästhetisierten Gesellschaft

"Die erlebnisbetonte Leistungsgesellschaft stellt immer höhere Anforderungen und Ansprüche an ihre Mitglieder. Will man erfolgreich sein, müssen Ressourcen wie Kompetenz, Einfluß, Geschmack und andere spezifische Fähigkeiten genutzt werden. Diese sind aber nicht als Resultate einer individuellen Biographie zu begreifen, sondern als Handlungskompetenzen, die erworben werden und als transformierte Sozialstrukturen in Erscheinung treten. In den ästhetisierten Lebenswelten der Erlebnisgesellschaft kommt dem Geschmack eine besondere Bedeutung zu: Geschmack verdichtet sich in kulturellen Stilen, die als Distinktionsstrategien genutzt, Geschmacksklassen konstituieren. Als Klasse sind so Gesellschaftsmitglieder mit ähnlicher Ressourcenausstattung zu verstehen, die im Kultur-Raum aufgrund von ähnlichen Klassifikationsstrategien entstehen. Strukturelle Ungleichheit verwandelt sich durch Klassifikation in expressive Unterscheidbarkeit. Der Habitus wirkt überall dort, wo Distinktion als Ausschluß anderer durch Monopolisierung von Geschmack, Handlungskompetenz und Situationsmanagement funktioniert. Diese zentralen Aussagen werden im Vortrag in drei Abschnitten abgehandelt: 1. Restrukturierung der Klassengesellschaft, 2. Kulturelle Fundierung der Ungleichheit, 3.Klassenbildung, subtile Distinktion und ästhetische Lebensführung." (Autorenreferat

Developing Web-based Search Portals on Birds for Different Target Groups

This paper presents the experiences and interim results from the ongoing iterative development and testing of four distinctive search portals on birds. The search portals are developed within the EU STERNA project and address different target user groups. Based upon specific use case scenarios the search portals are tested and validated in four specific phases, applying three different testing methods: WAMMI online evaluation, focus group evaluation and task-based usability tests. The paper introduces the four search portals, depicts the testing methodology and presents the first results from the ongoing user validation process

Label-Free Investigations on the G Protein Dependent Signaling Pathways of Histamine Receptors

G protein activation represents an early key event in the complex GPCR signal transduction process and is usually studied by label-dependent methods targeting specific molecular events. However, the constrained environment of such “invasive” techniques could interfere with biological processes. Although histamine receptors (HRs) represent (evolving) drug targets, their signal transduction is not fully understood. To address this issue, we established a non-invasive dynamic mass redistribution (DMR) assay for the human H1–4Rs expressed in HEK cells, showing excellent signal-to-background ratios above 100 for histamine (HIS) and higher than 24 for inverse agonists with pEC50 values consistent with literature. Taking advantage of the integrative nature of the DMR assay, the involvement of endogenous Gαq/11, Gαs, Gα12/13 and Gβγ proteins was explored, pursuing a two-pronged approach, namely that of classical pharmacology (G protein modulators) and that of molecular biology (Gα knock-out HEK cells). We showed that signal transduction of hH1–4Rs occurred mainly, but not exclusively, via their canonical Gα proteins. For example, in addition to Gαi/o, the Gαq/11 protein was proven to contribute to the DMR response of hH3,4Rs. Moreover, the Gα12/13 was identified to be involved in the hH2R mediated signaling pathway. These results are considered as a basis for future investigations on the (patho)physiological role and the pharmacological potential of H1–4Rs

Accurate band mapping via photoemission from thin films

Electron bands in solids can be determined in angle-resolved photoemission experiments from thin films, where the perpendicular wave vector (k⊥) uncertainty that characterizes photoemission from bulk crystals is removed. However, the comparison with state-of-the-art quasiparticle band-structure calculations has never been done. In this work we have mapped both initial-state (occupied) and final-state (empty) E(k⊥) bands along the A axis of aluminum, from photon-energy- and thickness-dependent quantum-well spectra of aluminum films. For final states the best fit is obtained with inverse low-energy electron diffraction band structure calculations. For initial-state bands of Cu and Al, thin-film data display excellent agreement with bulk quasiparticle theory, suggesting the use of thin films as model systems to investigate fine effects in the crystal band structure.This work has been supported in part by the Universidad del País Vasco (A.Mu. and J.E.O. under Contract No. 00057.240-EA-13668/2001, and A.Ma., A.R., and F.J.G.A. under Contract No. 00206.215-13639/2001), the European Community (EC) research training network NANOPHASE [A.Ma. and A.R. (Grant No. HPRN-CT-2000-00167)], and the Spanish Ministerio de Ciencia y Tecnología [A.Ma., A.R., and F.J.G.A. (Grant No. MAT2001-0946), and J.L. and E.G.M. (BFM2001-0244)].Peer Reviewe