Glacial Deposited Sediments: Evidence for Ice Sheets along Northern Rim of Beringia

The East Siberian and the Chukchi Shelf are of general interest concerning the distribution of regional ice sheets. Both shelves felt dry during glacial times, which is named Beringia. From geological onshore mapping it was proposed that Beringia did not host large ice sheets during glacial times. Instead, a widespread mountain glaciation was suggested. However, geophysical data of the last two decades imaged a complex pattern of glaciogenic erosion of even the shallow shelf areas. The results indicate the presence of several streams in bathymetric troughs and point to an ice sheet on the outer shelf of Beringia with unknown size. Advancing ice sheets deliver large amounts of sediments to the continental margins and change the slope properties. However, the amount of delivered sediments varies along the ice sheet margin. In seismic data, these deposits form chaotic or opaque wedges separated by strong semi-continuous to continuous reflections. We use published and reprocessed 2D multi-channel seismic reflection data from R/V Marcus G. Langseth located between 147°E in the East Siberian Sea to the to 149°W in the Beaufort Sea to investigate in greater detail the glacial deposited sediments along the northern margins of Beringia. We found in this data glacial deposits relocating the shelf break up to 13 km along the slope between 175° E and 161° W. The maximum thickness of these sediments reaches up to 450 m. Deposits in the Northwind Basin between 165° W and 161° W are separated by strong reflections indicating 3-5 glacial advances. On the Kucherov Terrace between 175°E to 176°W, we found erosion and grounded ice deposits in water depths shallower than 1200 m. However, slopes in the western East Siberian Sea and in the Beaufort Sea lack of thick glacial deposits. This might indicate either less intense or no glaciation. The amounts of glacial deposited sediments along the margins of Beringia are significant smaller than the reported amounts along the Norwegian and Greenland margins. In conclusion, our results indicate a less intense glaciation of Beringia compared to other glaciated margins during the Quaternary

The geography of stock exchanges in Imperial Germany

23 Stock Exchanges were in operation in Germany in 1913. We provide new data about the number of listed firms, their market value, and the number of IPOs between 1897 and 1913 for all exchanges. We assess reasons why a firm opts to be listed at a certain exchange. Large firms tend to be listed and tend to go public at the Berlin Stock Exchange, while the regional stock exchanges were important hosts for small and medium-sized firms. Borders and distance affect listing decisions, suggesting that a patriotic home bias and asymmetric information between issuer and investors affected listing decisions

Plio-Pleistocene submarine glaciogenic morphology of the Chukchi Shelf, Arctic Ocean

Ongoing research aims to constrain the extent of grounded ice shelves around the Arctic Ocean during the last glacial periods. Here, the Chukchi region is of special interest because of its broad, shallow shelf. In general, little is known about possible sources and the areal extent of ice sheets if any existed on the Chukchi shelf. Bathymetric and sub bottom profiler data from the Chukchi Sea margins as well as from the Arlis Plateau to the west show complex patterns of glaciogenic erosion like Mega Scale Glacial Lineations (MSGL) at water depths of more than 500 m. The different directions of those MSGL indicate the presence of ice shelves and streams and point to an East Siberian Ice Sheet of unknown size. On the Chukchi Shelf, no evidences for the existence of an ice shelf for water depths shallower than 350 m have been described yet. We re-processed 2D multi-channel seismic data acquired in 2011 from R/V Marcus G. Langseth to investigate glaciogenic features on the shallow shelf. These data reveal new insights into the formation of the northern Chukchi Shelf. The first up to 500 ms TWT of the seismic data show strongly eroded reflectors and reworked sediments. Additionally, small-scale channels with a few tens of meters width and a depth of 20 ms TWT disrupt the horizons below the reworked layers. Furthermore, the seismic data show channels with widths up to few km and depths up to 150 ms TWT as well as truncated well stratified reflectors. All above described features can be observed on parts of the Chukchi shelf with water depths shallower than 900 m

Formation and Development of Nanometer-sized Cybotactic Clusters in Bent-core Nematic Liquid Crystalline Compounds

Two homologue achiral bent-core liquid crystals (LCs), BCN66 and BCN84, in their nematic phases are studied by dielectric spectroscopy in the frequency range 10 Hz–10 MHz. In each of these compounds, two relaxation processes are identified and assigned to (i) collective dynamics of molecules in nanometer-sized cybotactic clusters and (ii) individual molecular relaxations, in the ascending order of frequency of the probe field. The temperature and the bias electric field dependence of the dielectric strength and relaxation frequency for these processes are shown to give rise to sharpness in cluster boundaries, increased size and volume fraction in the LC nematic phase. The effect of the bias field on the LC cell is similar to reducing its temperature; both variables increase the cluster size and volume fraction and give rise to sharp cluster boundaries. The findings confirm that dielectric spectroscopy is a powerful and an extremely useful technique to provide a deeper understanding of the mechanism of cybotactic cluster formation in the isotropic liquid and the nematic phase of LCs as a function of temperature and the bias field

Spontaneous Helix Formation in Non-Chiral Bent-Core Liquid Crystals with Fast Linear Electro-Optic Effect

Liquid crystals (LCs) represent one of the foundations of modern communication and photonic technologies. Present display technologies are based mainly on nematic LCs, which suffer from limited response time for use in active colour sequential displays and limited image grey scale. Herein we report the first observation of a spontaneously formed helix in a polar tilted smectic LC phase (SmC phase) of achiral bent-core (BC) molecules with the axis of helix lying parallel to the layer normal and a pitch much shorter than the optical wavelength. This new phase shows fast (∼30 μs) grey-scale switching due to the deformation of the helix by the electric field. Even more importantly, defect-free alignment is easily achieved for the first time for a BC mesogen, thus providing potential use in large-scale devices with fast linear and thresholdless electro-optical response. les

Untersuchungen zur Qualitätsveränderung bei der Verarbeitung und Lagerung von ausgewählten Erzeugnissen aus Bio-Forellen und konventionell erzeugten Forellen als Voraussetzung für die Erstellung einer Handlungshilfe für handwerkliche Forellenzuchtbetriebe

Die Aufzucht der Forellen wurde unter standardisierten Bedingungen durchgeführt (Modellversuch). Futterzusammensetzung und Besatzdichte entsprachen ökologischen und konventionellen Zuchtbedingungen. Es wurden verschiedene Ökofutter getestet. Extrudiertes Ökofutter desselben Herstellers schnitt deutlich besser ab als pelletiertes. Die Leistungsvorteile (Wachstum, Futterauswertung, Proteinausnutzung) eines hochwertigen konventionellen Futters hingen von der Pelletgröße ab. Mit 6,0 % Fett waren die geräucherten konventionellen Forellen des Modellversuches deutlicher fetter als die ökologischen (4,5 %). TVB-N- Wert, Redoxpotential, Malondi-aldehyd und Glutathion sowie physikalische Methoden (Farbmessung, elektronische Nase) waren zur Verfolgung von Qualitätsveränderungen bei einer Lagerung bei 2-4 °C ungeeignet. Aufzuchtsbedingte unterschiedliche Gehalte einiger Fettsäuren sind als ernährungsphysiologisch unbedeutend einzustufen. Die mikrobiologische Qualität war gut oder sehr gut. In konventionellen vakuumverpackten Räucherfilets wurden seltener Bakterien und niedrigere Gesamtkeimzahlen gegenüber den ökologisch produzierten gefunden. Die Befunde waren aber nicht geeignet, die sensorische Qualität zu beeinflussen. Diese nahm kontinuierlich ab, war jedoch am Ende der Lagerung noch als durchschnittlich zu bezeichnen und keinesfalls verdorben. In Übereinstimmung mit Ergebnissen des Vorgängerprojektes „Bioforelle“ an rohen Forellen konnten auch in den Räucherforellen weder reproduzierbare Auswirkungen der Produktionsform noch qualitative Unterschiede festgestellt werden. Durch Besichtigung kleiner bis mittelständischer Räuchereien wurden individuelle Verarbeitungsstrukturen erfasst. Die Auswirkungen der wichtigsten Arbeitsschritte (Salzen, Räuchern) auf die Qualität wurden näher untersucht. Die Kerntemperatur von 60°C wurde in konventionellen Handelsproben nicht immer, bei der untersuchten Bioware zuverlässig erreicht. Die besuchten ökologisch arbeitenden Betriebe waren modern ausgestattet unter Berücksichtigung heutiger Hygienestandards