ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Ascent of dinosaurs linked to an iridium anomaly at the Triassic-Jurassic boundary (2002)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2002-05-23
    Description: Analysis of tetrapod footprints and skeletal material from more than 70 localities in eastern North America shows that large theropod dinosaurs appeared less than 10,000 years after the Triassic-Jurassic boundary and less than 30,000 years after the last Triassic taxa, synchronous with a terrestrial mass extinction. This extraordinary turnover is associated with an iridium anomaly (up to 285 parts per trillion, with an average maximum of 141 parts per trillion) and a fern spore spike, suggesting that a bolide impact was the cause. Eastern North American dinosaurian diversity reached a stable maximum less than 100,000 years after the boundary, marking the establishment of dinosaur-dominated communities that prevailed for the next 135 million years.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Olsen, P E -- Kent, D V -- Sues, H-D -- Koeberl, C -- Huber, H -- Montanari, A -- Rainforth, E C -- Fowell, S J -- Szajna, M J -- Hartline, B W -- New York, N.Y. -- Science. 2002 May 17;296(5571):1305-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12016313" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Evolution ; *Dinosaurs ; *Ecosystem ; Ferns ; *Fossils ; Geologic Sediments/chemistry ; Iridium/*analysis ; Meteoroids ; Minor Planets ; North America ; Spores ; Time
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Microform bed clusters: are they preferred habitats for invertebrates in a flood-prone stream? (2002)
    Oxford, UK : Blackwell Science Ltd
    Freshwater biology 47 (2002), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SUMMARY 1. Microform bed clusters are bedform microunits in streams. They consist of an obstacle clast (a large surface stone) against which other stones are stacked in a specific manner. Stream ecologists have suggested that these clusters are better flood refugia and more valuable habitats for invertebrates than single surface stones because of their higher stability during high-flow events and their greater diversity of microhabitats available for colonisation.2. To test these predictions in the Schmiedlaine, a flood-prone prealpine stream, we sampled invertebrates on clustered and single stones on a total of seven occasions including before and after a moderate spate, two major floods and a minor spate. We also monitored surface particle stability during the second major flood and the minor spate.3. Before the second flood (return period 1–2 years), we determined the exact positions of 60 clusters (60 obstacle clasts with 136 associated smaller particles) and 50 single stones in a 250-m reach. We sampled the fauna on stones in the clusters, on well-embedded single stones, and on loose single stones. Only six obstacle clasts and one single stone remained after the flood, implying movement of almost the entire surface layer. Therefore, we sampled the invertebrates on stones in newly formed clusters, on well-embedded and single loose stones 3 and 11 days after the flood. The minor spate, in contrast to the second flood, moved only one of 495 monitored surface particles.4. Three days after the flood, invertebrate density on clustered stones and both single stone categories were similar and equalled 34% of the mean pre-flood density. Eight days later, density had almost doubled. The relatively high survival and rapid recovery suggest that invertebrates found refugia during the flood. However, the very low stability of clusters and single stones implied that surface particles were unimportant as refugia.5. Total invertebrate density and taxon richness were never higher on clustered than on single stones (regardless of the timing of sampling relative to the last previous high-flow event). Densities of the seven most common taxa and invertebrate community structure were also generally similar between particle types. We conclude that microform bed clusters cannot be regarded as more valuable invertebrate habitats than single surface stones in the Schmiedlaine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.2002.00966.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Oxygen detoxification in the strict anaerobic archaeon Archaeoglobus fulgidus: superoxide scavenging by Neelaredoxin (2000)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 38 (2000), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Archaeoglobus fulgidus is a hyperthermophilic sulphate-reducing archaeon. It has an optimum growth temperature of 83°C and is described as a strict anaerobe. Its genome lacks any homologue of canonical superoxide (O2·−) dismutases. In this work, we show that neelaredoxin (Nlr) is the main O2·− scavenger in A. fulgidus, by studying both the wild-type and recombinant proteins. Nlr is a 125-amino-acid blue-coloured protein containing a single iron atom/molecule, which in the oxidized state is high spin ferric. This iron centre has a reduction potential of +230 mV at pH 7.0. Nitroblue tetrazolium-stained gel assays of cell-soluble extracts show that Nlr is the main protein from A. fulgidus which is reactive towards O2·−. Furthermore, it is shown that Nlr is able to both reduce and dismutate O2·−, thus having a bifunctional reactivity towards O2·−. Kinetic and spectroscopic studies indicate that Nlr's superoxide reductase activity may allow the cell to eliminate O2·− quickly in a NAD(P)H-dependent pathway. On the other hand, Nlr's superoxide dismutation activity will allow the cell to detoxify O2·− independently of the cell redox status. Its superoxide dismutase activity was estimated to be 59 U mg−1 by the xanthine/xanthine oxidase assay at 25°C. Pulse radiolysis studies with the isolated and reduced Nlr proved unambiguously that it has superoxide dismutase activity; at pH 7.1 and 83°C, the rate constant is 5 × 106 M−1 s−1. Besides the superoxide dismutase activity, soluble cell extracts of A. fulgidus also exhibit catalase and NAD(P)H/oxygen oxidoreductase activities. By putting these findings together with the entire genomic data available, a possible oxygen detoxification mechanism in A. fulgidus is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.2000.02121.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Towards the ecology of hyperthermophiles: biotopes, new isolation strategies and novel metabolic properties (2000)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology reviews 24 (2000), S. 0 
    Details
    ISSN: 1574-6976
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Ecological studies have shown that water-containing terrestrial, subterranean and submarine high-temperature environments harbor a great diversity of hyperthermophilic prokaryotes, growing fastest at temperatures of 80°C or above. The investigations included cultivation, isolation and detailed analysis of these hyperthermophiles as well as in situ 16S rRNA gene sequence analysis and in situ hybridization studies. For a safe and fast isolation of novel hyperthermophiles from mixed cultures, a new, plating-independent isolation technique was developed, based on the use of a laser microscope (‘optical tweezers’). This method, combined with 16S rRNA gene sequence analysis and whole-cell hybridization using fluorescently labelled oligonucleotide probes, even allows the recovery of pure cultures of phylogenetically predicted organisms harboring novel 16S rRNA gene sequences. In their natural habitats, hyperthermophiles form complex food webs, consisting of primary producers and consumers of organic material. Their metabolic potential includes various types of aerobic and anaerobic respiration and different modes of fermentation. In hydrothermal and geothermal environments, hyperthermophiles have important ecological functions in biogeochemical processes. Members of the Sulfolobales are able to mobilize heavy metals from sulfidic ores like pyrite or chalcopyrite. Biomineralization processes of hyperthermophiles include the formation of magnetite from iron or the precipitation of arsenate as realgar, a reaction performed by a novel hyperthermophile that was isolated from Pisciarelli Solfatara, Naples, Italy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6976.2000.tb00562.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Optimization of the Multiparameter γ-γ Coincidence Spectrometry for the Determination of Iridium in Geological Materials (2000)
    Springer
    Journal of radioanalytical and nuclear chemistry 244 (2000), S. 655-660 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A new ICS system has recently been constructed at the University of Vienna. Using low-energy planar detectors and improved electronic components, the detection limit could be lowered to about ≤20 ng/g for carbonate rocks. As standards, either synthetic iridium standards loaded on high-purity quartz powder, or well characterized geological reference materials, were used. In a series of test measurements we attempted to optimize external factors, such as sample size, irradiation time and flux, decay time, and measuring time, and to determine the optimal electronic configuration, including shaping time, coincidence time, range, and gain. Further measurements are geared towards the establishment of a simple and effective routine procedure for a variety of rock types containing iridium at concentrations within the 0.02–1 ppb range.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006754409429
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Use of γ-γ Coincidence Spectrometry in the Geochemical Study of Diamictites from South Africa (2000)
    Springer
    Journal of radioanalytical and nuclear chemistry 244 (2000), S. 603-607 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract We used γ-γ coincidence spectrometry to investigate the possible presence of a meteoritical component in 27 samples of South African diamictites. Recently, several studies have suggested that some tillites/diamictites may represent impact breccias, but a petrographical study by our group found no evidence for the presence of impact-characteristic shocked minerals. The siderophile elements, such as Cr, Co, Ni, and, especially, the platinum group elements, have high abundances in meteorites, but low abundances in terrestrial crustal rocks. The Ir content of the diamictites was measured with the new iridium coincidence spectrometer (ICS) at the University of Vienna, with detection limits of around 0.02 ppb. No enrichments in the contents of Ir and other siderophile elements compared to average crustal concentrations were found; thus, no unequivocal evidence for an impact origin of these diamictites of the South African Dwyka Group can be documented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006717417181
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Die Glykoside der Wurzeln von Xysmalobium undulatum R. Br. Erste Mitteilung. Glykoside und Aglykone, 69. Mitt. (1951)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 34 (1951), S. 46-70 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Beschaffung und Untersuchung der Wurzeln von Xysmalobium undulatum R. Br. wird beschrieben und Gründe angegeben, die dafür sprechen, dass es sich bei dieser Asclepiadacee um die (oder eine) Stammpflanze der bekannten „Uzara-Medizin“ handelt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19510340108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Über das Alkaloid Serpentinin aus Rauwolfia serpentina Benth. Mitt. XII über Rauwolfiaalkaloide (1954)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 37 (1954), S. 1912-1920 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus Rauwolfia serpentina Benth. wurde das Alkaloid Serpentinin isoliert und seine Konstitution untersucht. Die erhaltenen Abbauprodukte erlauben es noch nicht, eine Formel aufzustellen, ausserdem sind die Beziehungen zwischen den beiden Alkaloiden Serpentin und Serpentinin noch unklar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19540370640
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Die Konstitution des Alkaloids Artabotrin (Iso-corydin) (1952)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 35 (1952), S. 111-113 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wurde gefunden, dass das Alkaloid Artabotrin mit Iso-corydin identisch ist. Der Name „Artabotrin“ ist aus der Literatur zu streichen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19520350114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Identification of 86 candidates for small non-messenger RNAs from the archaeon Archaeoglobus fulgidus (2002)
    National Academy of Sciences
    Details
    Publication Date: 2002-05-28
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...