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  • 42.10  (1)
  • Aortic baroreceptor afferents  (1)
  • Ash-free biomass  (1)
  • Bone mineral analysis  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Experimental measurements of non-Gaussian scattering by a fractal diffuser (1983)
    Springer
    Applied physics 31 (1983), S. 179-186 
    Details
    ISSN: 1432-0649
    Keywords: 42.10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report measurements of the statistics of intensity scintillations of 10.6 μm CO2 radiation scattered by a two-dimensional fractal phase screen. The surface profile of the phase screen is measured and shown to have a Hausdorff-Besicovitch dimension of approximately 1.4. Measurements of the on-axis intensity fluctuations as a function of illuminated spot size in both the Fresnel and Fraunhofer region are presented. This fractal scatterer does not produce the high contrast values found in speckle patterns of smoothlyvarying surfaces. Both direct and heterodyne detection results are reported. Measurements of the average intensity as a function of angle are also presented, and illustrate the failure of theoretical models which assume a Gaussian phase autocorrelation function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688840
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Earthworm response to rotation and tillage in a Missouri claypan soil (1999)
    Springer
    Biology and fertility of soils 29 (1999), S. 343-347 
    Details
    ISSN: 1432-0789
    Keywords: Key words Aporrectodea trapezoides ; Diplocardia singularis ; Population density ; Ash-free biomass ; Crop rotation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Agricultural management practices affect earthworm populations. A field experiment was conducted to determine the effect of two rotations and two tillage systems on earthworm population density and biomass in a claypan soil. The rotations were soybean/corn and wheat/corn, and the tillage systems were conventional tillage (chisel plowed and disked) and no-tillage. Earthworm and soil samples were collected in fall 1995, spring 1996, and fall 1996. Aporrectodea trapezoides and Diplocardia singularis were the species identified at the site. A. trapezoides accounted for 92–96% of the total earthworm population density and D. singularis accounted for only 4–8%. In a no-till system, soybean/corn rotation resulted in significantly greater population density of A. trapezoides compared with the wheat/corn rotation. Crop residue quality (low C:N ratio) and quantity were important factors in increasing A. trapezoides population density and biomass. Conventional tillage markedly decreased population density and biomass of both earthworm species. Our results suggest that rotation and tillage significantly affect earthworm population density and biomass.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050563
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Sex differences in geometry of the femoral neck with aging: A structural analysis of bone mineral data (1992)
    Springer
    Calcified tissue international 50 (1992), S. 24-29 
    Details
    ISSN: 1432-0827
    Keywords: Bone mineral analysis ; Hip strength analysis ; Age ; Femoral neck stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The greater hip fracture rate among elderly women is generally ascribed to differences in femoral neck strength between the sexes. Strength of a given bone is a function of both its material properties and the magnitudes of mechanical stresses within it. This study examined the hypothesis that these apparent strength differences between the sexes are due to dissimilarities in the restructuring of the femoral neck with age, which result in higher stresses in elderly women. Using Hip Strength Analysis, a computer program developed by the authors, femoral neck cross-sectional geometric properties for stress analyses were derived from bone mineral image data of 409 community living, white subjects ranging from 19 to 93 years of age. Though both sexes show declines in femoral neck bone mineral density (BMD) and cross-sectional area with age, only females show a decline in the cross-sectional moment of inertia (CSMI, a geometric index of bone rigidity). The lack of decline in male CSMI appears to be a result of a small but significant increase in femoral neck girth. Similar age-related changes have been observed in the femoral shaft by others. The net effect of these observed changes is that mechanical stresses in the femoral neck of females appear to increase at three times the rate per decade of those of males. These results lend support to the hypothesis that the higher fracture rate in elderly women is due, at least in part, to elevated levels of mechanical stress, resulting from a combination of greater bone loss and less compensatory geometric restructuring with age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297293
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Presynaptic depolarization in myelinated vagal afferent fibres terminating in the nucleus of the tractus solitarius in the cat (1986)
    Springer
    Pflügers Archiv 406 (1986), S. 12-19 
    Details
    ISSN: 1432-2013
    Keywords: Slowly adapting lung stretch receptor afferents ; Aortic baroreceptor afferents ; Presynaptic depolarization ; Neural control of respiration ; Neural control of circulation ; Nuclei of the solitary tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The presynaptic influences that act on terminals of slowly adapting lung stretch receptor afferents and aortic baroreceptor afferents within the nucleus of the solitary tract were assessed using intracellular recording and antidromic stimulation techniques. Central respiratory influences on the axcitability of lung stretch receptor terminals were observed in 29% (4 of 14) of measurements. These were confirmed in intracellular recordings where membrane depolarizations in synchrony with phrenic nerve discharge were seen in 17% (4 of 24) of fibres. In three cases membrane depolarization also occurred synchronously with artificial lung inflation. Neither tests of excitability nor intracellular recording revealed any evidence for equivalent presynaptic influences on 16 myelinated aortic baroreceptor terminals. Stimulation of the superior laryngeal nerve evoked depolarizations in 50% (7 of 14) of lung stretch receptor terminals. These took the form of complex waves of depolarization with both short (3–8 ms) and long latency (27–35 ms) components. The amplitude of the long latency response increased during the period of phrenic nerve discharge, i.e. during “central inspiration”. These effects are discussed in relation to the central respiratory influences on both respiratory and cardiovascular reflexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582946
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    Paper (German National Licenses)
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