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  • 1995-1999  (2)
  • 1905-1909
  • 1900-1904
  • 1995  (2)
  • Electrocochleography  (1)
  • HAC  (1)
  • 1
    ISSN: 1573-5117
    Keywords: macrophytes ; streams ; PCA ; HAC ; bio-indicator ; water chemistry ; geology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The aquatic vegetation of twenty one streams, located at the head of watersheds and representative of the geological diversity of the Lorraine, was analysed with regard to its environmental d escriptors (geology, morphometry and water chemistry). A Principal Components Analysis was carried out on the data (230 stations and 134 variables). using 40 active chemical and morphometrical variables. This procedure was followed by a Hierarchical Ascending Classification for grouping the variables into classes. The analysis of the mesological and chemical structures of the streams indicated the dominance of geochemical parameters compared to pollution parameters. The indicator capacity of several species was revealed, e.g. Scapania undulata for weakly mineralized, oligotrophic waters; Potamogeton pectinatus for eutrophicated waters and Ranunculus fluitans for high nitrate levels. Five species groups characterizing the geology and mineralization as well as the perturbations in the quality of the water or the environment were identified (e.g. pollution, eutrophication, reposition and reshaping).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 20-25 
    ISSN: 1434-4726
    Keywords: Inner ear pathology ; Noise trauma ; Electrophysiology ; Electrocochleography ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Low-frequency acoustic biasing using an intensive phase-shifted, low-frequency masker was studied according to its ability to determine disorders of cochlear micromechanics following noise trauma in the guinea pig as animal model. Statistical analyses proved that this technique allowed electrophysiological differentiation of controls versus groups with different degrees of experimentally induced threshold shifts. To substantiate group differences an intensity of at least 70 dB SPL was required for the 52 Hz masker and the difference in relation to the test-tone intensity had to be ±10 or ±20 dB SPL. The noise-traumatized cochlea could be identified by means of a threshold shift for the 5 μV pseudothreshold, a low modulation span of the compound action potential amplitude (〈 25–50μLV frequency dependent), and reduced positive summating potential amplitude with negative non-modulating values within the different measurement phases for 1 and 2kHz stimulation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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