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  • 1
    Electronic Resource
    Electronic Resource
    Bowhead whale (Balaena mysticetus) growth and feeding as estimated by δ13C techniques (1989)
    Springer
    Marine biology 103 (1989), S. 433-443 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tissue δ13C of bowhead whale, Balaena mysticetus, varies seasonally in response to geographic variations in the δ13C of prey organisms consumed along the annual migratory route between the Bering, Chukchi and Beaufort Seas. Seasonal changes in body δ13C of whales taken in 1986 from Alaskan waters provide a means of estimating energy intake from the different habitats in which the whales feed. Adult bowheads do not show significant seasonal shifts in the δ13C of muscle and visceral fat. Their enrichment in 13C relative to subadult whales suggests that they acquire most of their food from fall and winter feeding or from unsampled parts of the summer range where zooplankton are enriched in 13C. Young individuals however, undergo marked seasonal shifts indicating that they feed heavily both in the summer and autumn or winter. Oscillations in δ13C along the length of the baleen also provide a measure of age. Baleen growth rates decline as the whales age and provide a means of correcting for wear loss and allow aging of individuals less than ∼ 12 yr old. Although body length is a poor indicator of age in young bowhead whales, baleen length is closely correlated. Growth rates of bowheads after Year 1 are slow (∼ 0.4m yr-1) and up to 20 yr are required to reach the assumed length of sexual maturity at 13 to 14m.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00399575
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  • 2
    Electronic Resource
    Electronic Resource
    Carbon-isotope ratio gradients in western arctic zooplankton (1989)
    Springer
    Marine biology 103 (1989), S. 427-432 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zooplankton from 87 stations in the Bering, Chukchi and Beaufort Seas sampled in 1985, 1986 and 1987 showed a geographic gradient in stable carbon-isotope ratios (δ13C). The zooplankton most depleted in 13C were found in the central and eastern Beaufort Sea and those most enriched were from the Bering and Chukchi Seas. Average δ13C values ranged from-20.9 to-26.7‰ for copepods and from-19.4 to-25.1‰ for euphausiids. Euphausiids show a minimum of 1.0‰ enrichment relative to copepods throughout the study area. Relative biomasses of the major zooplankton taxa varied significantly across the Alaskan Beaufort Sea in October 1986, with euphausiids dominating in the west and copepods in the east. These differences in taxonomic composition affected the weighted δ13C values for “total” zooplankton and may produce an even more pronounced geographic gradient in zooplankton δ13C than that found within a single taxon. The bowhead whale Balaena mysticetus migrates between wintering areas in the Bering Sea and summering areas in the Beaufort Sea and feeds over this geographic range. The zooplankton δ13C gradient is the probable source of δ13C oscillations found along the baleen plates of this planktivore.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00399574
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Sequence diversity and unusual variability at the het-c locus involved in vegetative incompatibility in the fungus Podospora anserina (1995)
    Springer
    Current genetics 27 (1995), S. 466-471 
    Details
    ISSN: 1432-0983
    Keywords: Vegetative incompatibility ; Filamentous fungi ; Allele variability ; Podospora anserina
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The het-c locus of the filamentous fungus Podospora anserina controls heterokaryon formation through genetic interaction with alleles of the unlinked loci het-e and het-d. We have isolated four wild-type and two mutant alleles of the het-c locus. A comparison of the predicted proteins encoded by the different wild-type alleles revealed an unusual high level of amino-acid replacements compared to silent polymorphisms but only one amino-acid difference is sufficient to modify the specificity of het-c alleles. Chimeric genes constructed in vitro may exhibit a new specificity different from that of any known wild-type allele.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00311217
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  • 4
    Electronic Resource
    Electronic Resource
    Vibrationally stimulated ionization of carbon monoxide in optical pumping experiments
    Amsterdam : Elsevier
    Chemical Physics 173 (1993), S. 491-504 
    Details
    ISSN: 0301-0104
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0301-0104(93)80163-4
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  • 5
    Electronic Resource
    Electronic Resource
    Vibrational and electronic excitation of nitric oxide in optical pumping experiments
    Amsterdam : Elsevier
    Chemical Physics 174 (1993), S. 219-228 
    Details
    ISSN: 0301-0104
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0301-0104(93)87006-9
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  • 6
    Electronic Resource
    Electronic Resource
    Sub-Doppler Heterodyne Frequency Measurements of Carbonyl Sulfide Transitions between 56 and 62 THz
    Amsterdam : Elsevier
    Journal of Molecular Spectroscopy 167 (1994), S. 419-428 
    Details
    ISSN: 0022-2852
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1006/jmsp.1994.1246
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  • 7
    Electronic Resource
    Electronic Resource
    CO-laser side-band spectrometer: Sub-Doppler heterodyne frequency measurements around 5 µm (1995)
    Springer
    Applied physics 61 (1995), S. 169-173 
    Details
    ISSN: 1432-0649
    Keywords: 07.65.Gj ; 33.20.Ea ; 42.72.Ai
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report the realization of a tunable sub-Doppler heterodyne spectrometer with high absolute accuracy, employing side-band generation with a CO laser. The fixed-frequency CO-gas laser, working from 4.7 to 8.4µm, is made partially tunable by the use of microwave side-band generation in a CdTe Electro-Optical Modulator (EOM). This leads to tunable radiation of high spectral purity. We describe the design of the microwave EOM, adapted to the CO laser, its performance and its first application to highly accurate frequency measurements. The side-band radiation is used for sub-Doppler stabilization of the CO laser, while the carrier frequency is mixed with the frequencies of two CO2 reference lasers. As a first result, we present measurements of OCS transitions in the 4.9µm (61 THz) region, reaching an absolute accuracy of 30 kHz (Δν/ν = 5×1O−10). Further application of our spectrometer to calibration gases will establish a variety of InfraRed (IR) calibration standards with a new quality of accuracy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01090939
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  • 8
    Electronic Resource
    Electronic Resource
    The CO fundamental-band laser as secondary frequency standard at 5 µm (1994)
    Springer
    Applied physics 59 (1994), S. 159-166 
    Details
    ISSN: 1432-0649
    Keywords: 33.20 ; 07.65.Gj ; 42.72
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present a very high-resolution heterodyne spectrometer based on a CO laser which operates down to fundamental-band transitions of the molecule. This allows us to detect saturated absorption signals on these transitions at very low pressure (0.4 Pa) and laser intensity (〈 1 mW/cm2), yielding a linewidth of about 250 kHz. With the CO fundamental-band laser stabilized to these saturation signals we have measured the transition frequencies of the fundamental bands of three isotopic species to an accuracy of typically 20 kHz (Δv/v ≈ 3 × 10−10), referenced to the CO2 frequency standard. Together with additional frequency measurements of the first hot bands, these provide the first heterodyne frequency data of sub-Doppler accuracy for transitions in low lying bands of CO. They now represent the most accurate secondary frequency standard in the spectral region around 5 µm (60 THz).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01081166
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