Organic-rich sediments in brine-filled Shaban- and Kebrit Deeps, Northern Red Sea

The element compositions Si, Ca and Al of up to 2 1.1 ka old sediments in about 10 in long cores from the southern basin of the Shaban and Kebrit deeps in the northern Red Sea allowed a classification of major sediment types in carbonate sands and -muds and siliceous oozes. A FeOOH-enriched sediment horizon and a few samples with high Zn values in the Kebrit core indicate a hydrothermal origin probably near the brine-sea water interface with subsequent transport of hydrothermal compounds into the deep sediments. High organic carbon contents up to 8.4% are positively correlated with the Ba concentrations, which suggests that high bioproductivity, and rapid deposition (C-14 dating suggests a sedimentation rate near 70 cm/ka) led to the formation of sapropelic sediments between 11.8 and 13.6 ka (Younger Dryas). Organic petrological observations showed that the sediment organic material largely consists of <20 gm-sized roundish fecal pellets (intimate mixtures of organic matter and inorganic constituents) and bituminite. Terrestrial organic matter (pollens of land plants, fusinite etc.) is very rare in the sediment cores from both deeps. Organic-geochemical investigations of kerogens and organic extracts show that a significant (hydrothermal) hydrocarbon production did not occur in near-surface sediments of the Shaban and Kebrit deeps. Rock Eval pyrolysis of kerogens characterised the organic matter to be of type II quality. The delta C-13 values of the kerogens from the most prominent sapropel in the Shaban deep indicate an enrichment of(C-12-rich) nutrients in the water column during postglacial sapropel formation in the Younger Dryas. The n-alkane spectra are dominated by short chain lengths between n-C-15 and n-C-25 Prevailing n-C-15 to n-C-25 alkanes in low mature sediments are indicative of algal and microbial source. Pristane/phytane ratios are generally low (< I to similar to 1) which suggests that anoxic conditions prevailed within the anaerobic brine-filled deeps for the whole time covered by the sediments. This again indicates that sapropel formation was caused by high bioproductivity in the northern Red Sea rather than episodic stagnation with better preservation of the organic matter. Long-chain alkenones and sterols are the dominating compounds of the lipid fraction. Cholesterol contents in the sediment cores reflect phases of eukaryotes production in the water column, whereas the positive correlations of dinosterol with TOC and the amounts of total extract suggests that the major organic carbon source in the northern Red Sea during postglacial high-productivity stages were dinoflagellates. Another important carbon source, however, is indicated by the occurrence of 22,29,30-trisnorhopan-21 -one (TNH). Although the formation of TNH from its precursors is not fully understood, this compound probably results from microbial. degradation of intact bacteriohopanepolyols (BHP), which can be used as indicators for bacterial abundances and phyla. TNH is most likely produced at the brine-sea water interface where sedimenting organic matter accumulates and, if the redoxcline corresponds to the density gradient, the organic matter is subjected to efficient aerobic bacterial degradation processes. However, during high bioproductivity stage (Younger Dryas) the redoxcline was probably higher in the water column and thus, a significant TNH production at the brine-sea water interface did not occur at times of sapropel formation in the northern Red Sea deeps. (C) 2007 Elsevier B.V All rights reserved

Is there a “net generation” in veterinary medicine? A comparative study on the use of the Internet and Web 2.0 by students and the veterinary profession [Gibt es eine „net-Generation“ in der Tiermedizin? Eine Vergleichende Untersuchung zur Nutzung von Internet und Web 2.0 bei Studierenden und der Tierärzteschaft]

[english] Introduction: Informal and formal lifelong learning is essential at university and in the workplace. Apart from classical learning techniques, Web 2.0 tools can be used. It is controversial whether there is a so-called net generation amongst people under 30.Aims: To test the hypothesis that a net generation among students and young veterinarians exists.Methods: An online survey of students and veterinarians was conducted in the German-speaking countries which was advertised via online media and traditional print media.Results: 1780 people took part in the survey. Students and veterinarians have different usage patterns regarding social networks (91.9% vs. 69%) and IM (55.9% vs. 24.5%). All tools were predominantly used passively and in private, to a lesser extent also professionally and for studying.Outlook: The use of Web 2.0 tools is useful, however, teaching information and media skills, preparing codes of conduct for the internet and verification of user generated content is essential.<br>[german] Einleitung: Informelles und formelles lebenslanges Lernen ist im Studium und Beruf essenziell. Dazu können neben der klassischen Fortbildung auch Web 2.0 Tools benutzt werden. Umstritten in der Literatur ist allerdings, ob es unter den „Unter 30 Jährigen“ eine sogenannte Net-Generation gibt. Ziel: Überprüfung der Hypothese, dass eine Net-Generation unter Studierenden und jungen Tierärzten existiert. Methode: Eine Onlineumfrage unter Studierenden und der Tierärzteschaft wurde im deutschsprachigen Raum durchgeführt, die per Onlinemedien und klassischen Printmedien beworben wurde.Ergebnisse: An der Befragung haben 1780 Personen teilgenommen. Es gibt unterschiedliches Nutzungsverhalten von Studierenden und der Tierärzteschaft bei sozialen Netzwerken (91,9% vs. 69%) und IMs (55,9% vs. 24,5%). Alle Tools wurden hauptsächlich passiv und privat genutzt, im geringeren Maße auch für den Beruf und das Studium.Ausblick: Der Einsatz von Web 2.0 Tools ist sinnvoll, jedoch ist eine Vermittlung von Informations- und Medienkompetenz, Erstellung von Verhaltensregeln im Internet und Überprüfung von „user generated content“ essentiell

Entwicklung und Herstellung eines temporaer geschuetzten Feinstbleches (TGF) und Einfuehrung in den Markt Schlussbericht. Abschlussdatum: Juli 1982

TIB: RN 2598 (83-195)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman