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
    Monitoring an underground repository with modern seismological methods (1981)
    In:  Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., San Francisco, Pergamon, vol. 18, no. 8, pp. 517-527, pp. 1121, (ISSN: 1340-4202)
    Details
    Publication Date: 1981
    Keywords: Seismology ; Energy (of earthquakes) ; nuclear ; waste ; disposal
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    BIBLIOGRAPHY SEISMOLOGY
  • 2
    facet.materialart.
    Unknown
    A computer-aided method for calculating ultrasonic P- and S-wave velocities in rocks (1997)
    In:  International Journal of Rock Mechanics and Mining Sciences, Colorado Springs, US Air Force Academy, vol. 34, no. 2, pp. 309-316, pp. 2443, (ISSN: 1340-4202)
    Details
    Publication Date: 1997
    Keywords: Body waves ; Modelling ; Physical properties of rocks ; Acoustics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    BIBLIOGRAPHY SEISMOLOGY
  • 3
    facet.materialart.
    Unknown
    Soil rotifer communities are extremely diverse globally but spatially autocorrelated locally [Microbiology] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-03-16
    Description: Bdelloid rotifers are important contributors to biogeochemical cycling and trophic dynamics of both aquatic and terrestrial ecosystems, but little is known about their biogeographic distribution and community structure in terrestrial environments. This lack of knowledge stems from a lack of phylogenetic information and assumptions that microbial eukaryotes are globally distributed and have very limited diversity across vast geographic distances. However, these assumptions have been based more on assessments of their morphology than any measure of their true genetic diversity and biogeographic distribution. We developed specific primers for the cytochrome c oxidase subunit 1 (cox1) gene of bdelloid rotifers and amplified and cloned sequences using a nested sampling scheme that represented local (0–10 m) to global (up to 10,000 km) scales. Using phylogenetic community analyses (UniFrac) and geospatial statistics (semivariograms, mantel tests), we were able to reject the hypothesis that communities of rotifers are the same across even fairly small geographic distances. Bdelloid communities showed highly significant spatial structuring with spatial autocorrelation ranges of 54–133 m, but beyond that distance communities were extremely dissimilar. Furthermore, we show that these spatial patterns are driven not only by changes in relative abundance of phylotypes but also by absolute changes in phylotype occurrence (richness). There is almost no overlap in phylotype [or operational taxonomic unit (OTU)] occurrence between communities at distances beyond the autocorrelation range (~133 m). Such small species ranges, combined with their ubiquity in soils, make it increasingly clear that the biodiversity of bdelloid rotifers (and other less easily dispersed microbes) is much higher than previously thought.
    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
  • 4
    facet.materialart.
    Unknown
    Postgenomic processes dictate venom variation [Evolution] (2014)
    National Academy of Sciences
    Details
    Publication Date: 2014-06-25
    Description: Variation in venom composition is a ubiquitous phenomenon in snakes and occurs both interspecifically and intraspecifically. Venom variation can have severe outcomes for snakebite victims by rendering the specific antibodies found in antivenoms ineffective against heterologous toxins found in different venoms. The rapid evolutionary expansion of different toxin-encoding gene families...
    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
  • 5
    Electronic Resource
    Electronic Resource
    The role of intracellular messengers in adrenocorticotropin secretion in vitro (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 26-40 
    Details
    ISSN: 1420-9071
    Keywords: Opiomelanocortin ; cyclic adenosine 3′,5′-monophosphate (cAMP) ; calcium ; phosphatidylinositol (PI) ; glucocorticoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adrenocorticotropin (ACTH), an opiomelanocortin peptide, is secreted from anterior pituitary corticotrophs upon stimulation with corticotropin-releasing hormone (CRH), arginine vasopressin (AVP) and several other neuropeptides. CRH, the most potent secretagogue of ACTH, stimulates ACTH secretion and biosynthesis by increasing the production of cyclic adenosine 3′,5′-monophosphate (cAMP) within corticotrophs. AVP, which is a weak secretagogue of ACTH but strongly potentiates CRH-stimulated ACTH secretion, operates through the phosphatidylinositol (PI) transduction pathway. Both CRH and AVP increase cytosolic free [Ca2+] within normal corticotrophs indicating a role for Ca2+ in ACTH secretion. Glucocorticoids inhibit ACTH synthesis by suppressing transcription of the proopiomelanocortin (POMC) gene and attenuate ACTH release by decreasing cAMP accumulation stimulated by CRH. This review focuses on the roles of these intracellular messengers in ACTH secretion from normal anterior pituitary cells in vitro, and discusses the possible interactions between the cAMP, calcium and PI transduction pathways. Future areas of research are suggested such as identification of protein substrates of cAMP-dependent and Ca2+-dependent kinases within normal corticotrophs and evaluation of their role in ACTH biosynthesis and secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01955409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Attenuation of elastic waves in a cracked solid (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 101 (1990), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The spectral ratios technique is used to measure the attenuation and phase dispersion of the compressional wave and two shear waves polarized parallel and perpendicular to the cleavage of a slate, before and after cracks had been induced in the cleavage plane. The experimental results show that the quality factor Q of the rock sample is affected significantly by the presence of cracks, and that Q is more sensitive to crack parameters than the corresponding wave velocity.The frequency dependence of the attenuation coefficient α is generally assumed to be proportional to the nth power of frequency, ωn, where it is suggested that n has a value lying between 0.5 and 4, depending on the mechanism of the attenuation. The measured frequency dependence of α in this study, where α is influenced strongly by presence of aligned cracks, is demonstrably non-linear for both P- and S2- (polarized parallel to the cleavage) waves, implying that Q is frequency dependent. The convex shape of the attenuation coefficient curves for P-waves indicates a value of n of rather less than unity (0.5 ± 0.2), and the concave shape of the curves for S2-waves suggests a value of n of more than unity (1.8 ± 0.2), indicating that the frequency dependence of the attenuation also depends on wave mode. The attenuation coefficient for S1-waves (polarized perpendicular to the cleavage of the slate) has also been observed to behave in a non-linear manner (n= 3.5 ± 0.3) at low confining pressures. This is probably due to attenuation by scattering, where the frequency dependence in the long-wavelength limit is predicted to be to the fourth power of frequency. At high confining pressures, the scattering factor is found to be negligible and a linear relationship (constant Q) is observed, probably as a result of friction between crack surfaces.The crack-induced phase dispersion for P-, S1- and S2-waves has been observed to maintain causality. Although the P- and S2-wave velocities are not found to be sensitive to cracking (as predicted by Hudson's theory), the corresponding Q values have been found to vary significantly with confining pressure. This behaviour can be explained as due to the closure of low aspect ratio cracks at high confining pressure. The S2-wave phase dispersion is the only one which can be demonstrated to obey the Kramers-Kronig relation. This is made possible because the S2-waves can be recorded over a sufficiently wide frequency band with high enough signal-to-noise ratios.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1990.tb00766.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    SEISMIC AND ELECTRICAL PROPERTIES OF UNCONSOLIDATED PERMAFROST (1988)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 36 (1988), S. 0 
    Details
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: A model has been developed to relate the velocities of acoustic waves Vp and Vs in unconsolidated permafrost to the porosity and extent of freezing of the interstitial water. The permafrost is idealized as an assemblage of spherical quartz grains embedded in a matrix composed of spherical inclusions of water in ice. The wave-scattering theory of Kuster and Toksoz is used to determine the effective elastic moduli, and hence the acoustic velocities. The model predicts Vp and Vs to be decreasing functions of both the porosity and the water-to-ice ratio. The theory has been applied to laboratory measurements of Vp and Vs in 31 permafrost samples from the North American Arctic. Although no direct measurements were made of the extent of freezing in these samples, the data are consistent with the predictions of the model. Electrical resistivity measurements on the permafrost samples have demonstrated their essentially resistive behaviour. The ratio of resistivity of permafrost in its frozen state to that in its unfrozen state has been related to the extent of freezing in the samples.Electromagnetic and seismic reflection surveys can be used together in areas of permafrost: firstly an EM survey to determine the extent of freezing and then the acoustic velocity model to predict the velocities in the permafrost. The necessary transit time corrections can thus be made on seismic reflection records to compensate for the presence of permafrost.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2478.1988.tb02168.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    A COMPARISON OF LABORATORY AND FIELD MEASUREMENTS OF P-WAVE ANISOTROPY (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 41 (1993), S. 0 
    Details
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: P-wave velocity anisotropy determined from a cross-hole survey at the Imperial College borehole test site compares favourably with that measured in the laboratory on core from the holes. The holes penetrate a layered sequence of sandstones, shales and carbonates of the Namurian Upper Limestone Group. The Laboratory measurements of the vertical and horizontal velocities of core samples indicate that the shales exhibit P-wave anisotropies of over 20% but that the sandstones and limestones are only slightly anisotropic. These discrete measurements have been used in combination with wireline data to produce a log of P-wave anisotropy. Including the anisotropic information vastly improves the match between observed and synthetic traveltimes from the cross-hole data set. This implies that there is little frequency dependence of intrinsic P-wave anisotropy.Inversion of the cross-hole traveltimes highlights the need for good angular coverage in order to resolve the anisotropy parameters. The observed P-wave anisotropy of the field data is due to the combined effect of sedimentary layering and the intrinsic anisotropy of the rocks. The intrinsic anisotropy is found to be the dominant factor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2478.1993.tb00865.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    facet.materialart.
    Unknown
    Laboratory measurements of acoustic emissions and wave velocities associated with the formation of fractures in sandstones (2007)
    In:  Geological Society Special Publication 270: 93-99.
    Details
    Publication Date: 2007-10-08
    Description: Acoustic emission (AE), ultrasonic velocity and petrophysical property measurements are increasingly being used as tools to investigate mechanical, thermal and hydraulic changes in rock masses around underground excavations and in the exploration of oil and gas. In order to develop these measurements into an effective tool it is necessary to understand how they relate to changes in the fracture and fluid content under controlled laboratory conditions. A polyaxial (true triaxial) test system has been developed to perform high-resolution measurements of AE, ultrasonic velocities and fluid permeability characteristics in a cubic specimen under true-triaxial stress. The polyaxial system also allows the measurement of AEs using an array of small-diameter, high-frequency transducers. The measurements allow the AE source locations and mechanisms to be calculated, thus providing an analysis of the distribution, orientation and type of fracture growth in the specimens. Example results are given from an experiment, showing that AE mechanisms during crack initiation describe a dominant failure mode with a significant tensile component.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER
  • 10
    facet.materialart.
    Unknown
    Majority of CD4+ T cells from peripheral blood of HIV-1-infected individuals contain only one HIV DNA molecule (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-06-20
    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...