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
    Electronic Resource
    Electronic Resource
    Growth and survivorship of preemergence colonies ofRopalidia fasciata in relation to foundress group size in the subtropics (Hymenoptera: Vespidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 197-218 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Für die subtropische Polistine WespeRopalidia fasciata, die neue Nester unabhängig gründet, werden das Wachstum neugegründeter Kolonien sowie deren Überlebensrate beschrieben. Wird ein Nest von mehreren Weibchen gemeinsam gegründet, so stammen diese Weibchen vom selben Elternnest. Die Wachstumsrate neugegründeter Nester in Zellen/Tag (entspricht etwa der Eilegerate) hängt sowohl von dem Entwicklungsstadium der Kolonie wie auch von der Anzahl der Weibchen ab. Die Nestentwicklung (Zellen/Tag) ist positiv mit der Anzahl der Weibchen korreliert. Die Nestgröße nimmt im ersten Stadium, in dem nur Eier vorhanden sind, schneller zu als in dem folgenden Stadium, in dem auch Larven vorhanden sind. Die ersten Arbeiterinnen haben eine kürzere Entwicklungszeit als die später aufgezogenen Arbeiterinnen. Dieser Unterschied dürfte mit der intensiven Brutpflege der Weibchen für die ersten Larven zusammenhängen. Neugegründete Kolonien gehen vor allem durch äußere Ursachen zugrunde: (1) Durch den Verlust der Nestgründerinnen in solchen Kolonien, die von einem Weibchen allein gegründet wurden; (2) durch große Räuber, die auch Kolonien mit mehreren Nestgründerinnen vernichten.
    Notes: Summary Growth of preemergence colonies and colony survivorship of an independent founding polistine wasp,Ropalidia fasciata, in the subtropics are described. When a nest is founded by an association of females, foundresses originate from the same natal nest. Growth rate of preemergence nests in cells/day (nearly equivalent to oviposition rate) is a function of both stage of preemergence colony development and number of foundresses. Rate of nest development (cells/day) is positively correlated with the number of attending foundresses. Nest size increases more rapidly in the egg stage than in the larval stage. The first worker(s) develops faster than does later brood. This may be attributed to the fact that foundresses provide the first larva(e) with intensive care. Factors causing the failure of preemergence colonies are extrinsic: (1) the loss of the foundresses in single-foundress colonies, and (2) predation by large predators on colonies with multiple foundresses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02226304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Dominance of ovariectomized foundresses of the paper wasp,Polistes gallicus (1989)
    Springer
    Insectes sociaux 36 (1989), S. 219-234 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume L'ovariectomie des fondatrices deP. gallicus permet de distinguer une dominance sociale d'une dominance de reproduction. Les fondatrices ovariectomisées peuvent acquérir un rang dominant et le conserver. Les caractéristiques de la dominance sociale (temps passé au nid, faible récolte de nourriture, comportement de dominance) ne sont pas liées a la présence des ovaires. Par contre, les ovariectomisées ne manifestent pas de dominance de reproduction. Elles n'inhibent pas la formation des œufs des subordonnées avec la même intensité que les dominantes intactes; elles ne pratiquent pas d'oophagie différentielle. Ces deux caractères impliquent la présence d'ovaires actifs.
    Notes: Summary By means of ovariectomy it was possible to separate social and reproductive dominance in foundresses ofP. gallicus. Ovariectomized foundresses could achieve and maintain the dominant position. Characteristics of social dominance (time on nest, low contribution to food collecting, dominance behaviour) were found not to be connected to the presence of ovaries. Reproductive dominance, however, did not occur in ovariectomized foundresses. Ovariectomized dominant females did not nihibit egg-formation in subordinates to the same degree as intact dominant females did and they did not show differential oophagy. For both characteristics the presence of active ovaries is necessary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02226305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Factors determining hypopharyngeal gland activity of worker honey bees (Apis mellifera L.) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 264-276 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume On examine différents facteurs qui pourraient affecter l'activité des glandes hypopharyngiennes (HP) des ouvrières d'Abeille, tels que l'âge des ouvrières, les stades de développement du couvain et le moment d'introduction ou de retrait du couvain. L'âge des abeilles exerce une influence marquée sur l'activité des glandes HP; celle-ci est corrélée avec la croissance et la résorption des glandes décrites dans la littérature. Seules les larves sont aptes à activer les glandes HP, alors que les œufs et les nymphes ne le sont pas. Les glandes de l'abeille restent inactives pendant trois jours après le début du nourrissage des larves; elles conservent leur activité pendant trois jours environ après le retrait des larves. Ces données sont en accord avec l'hypothèse que c'est le comportement de nourrissage lui-même qui active les glandes; cependant, on ne peut exclure la possibilité que les larves produisent une phéromone stimulante.
    Notes: Summary The effects of worker age, brood stage and time of brood introduction or brood withdrawal on the hypopharyngeal (HP) gland activity of worker bees were examined. Worker age exerted a marked influence on gland activity. Only larvae affected HP gland activity, while eggs and pupae did not. Bees had inactive glands until their third day of larval feeding and they maintained high gland activity for approximately three days after larval removal. The data are congruent with the hypothesis that feeding behaviour itself causes gland activation, although the possibility that larvae produce a primer pheromone cannot be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Comparisons between two apparently distinct forms ofCamponotus nawai ITO (Hymenoptera: Formicidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 277-292 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Eine obligatorisch monogyne und eine fakultativ polygyne Form vonCamponotus nawai Ito wurden vergleichen. Jahreszeitliche Veränderungen der Koloniezusammensetzung waren bei beiden Formen ähnlich, abgesehen von der Zeit, in der geflügelte Geschlechtstiere in den Nestern zu finden sind. Die Sammelergebnisse lassen annehmen, daß bei der monogynen Form neue Kolonien nur von einzelnen Königinnen gegründet werden, während sie bei der polygynen Form durch Kolonieteilung entstehen. In polygynen Völkern waren alle oder fast alle Königinnen fertil, sa daß eine funktionelle Polygynie vorliegt. Königinnen der monogynen Form sind größer und haben größere Ovarien. Die Königinnen der polygynen Form zeigen eine bimodale Grossen-verteilung doch sind die kleineren Königinnen seltener. Bei der polygynen Form war die Anzahl der Königinnen mit der Menge der Brutstadien positiv korreliert, aber negativ mit der Menge der Brustadien pro Königin. Anscheinend besiedelt die polygyne Form mehr nördliche Gebiete als die monogyne, ihre Areale überschneiden sich kaum. Aufgrund der jahreszeitlich verschiedenen Schwarmzeiten sind die monogyne und die polygyne Form vonC. nawai möglicherweise zwei verschiedene Arten.
    Notes: Summary Obligately monogynous and facultatively polygynous forms ofCamponotus nawai Ito was compared. The seasonal changes of colony composition were similar in the two forms except for the season in which alates were found in nests. Collection data suggested that new colonies are founded only by single foundresses in the monogynous form, but mainly by colony budding in the polygynous form. All or most queens in polygynous nests were fertile, thus polygyny is functional. The body size and ovarian volume of queens were larger in the monogynous forms. Queens of the polygynous form showed bimodal size distribution, though smaller queens were less frequent. In the polygynous form, the number of queens was positively correlated with the number of immatures, but negatively correlated with the number of immatures per queen. It seems that the polygynous form occupies more northern regions than the monogynous one and their ranges contact parapatrically. The monogynous and polygynous forms ofC. nawai may be different species because of the differing mating seasons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224881
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Analysis of mining-induced microseismic events at Strathcona Mine, Subdury, Canada (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 455-474 
    Details
    ISSN: 1420-9136
    Keywords: Mining-induced events ; seismic monitoring ; focal mechanism ; source parameters ; Strathcona hard rock mine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Rockbursts and mining-induced seismic events have serious socio-economic consequences for the Canadian mining industry, as their mines are extended to greater depths. Automatic multichannel monitoring systems (Electro-Lab MP250s) are routinely, used to detect the arrival times of seismic waves radiated by mining-induced events and sensed on an array of single component transducers installed throughout a mine. These arrival times are then used to locate the events and produce maps of areas of high activity for use in mine planning and design. This approach has limitations in that, it does not allow a detailed analysis of source mechanisms, which could be extracted if whole waveform signals are recorded and analyzed. A major research project, sponsored by the Natural Sciences and Engineering Research Council of Canada (NSERC) with the collaboration of the Canadian mining industry, is aimed at enhancing existing mine seismic monitoring technology in Canada, in order to carry out more advanced processing of data to obtain fundamental scientific information on mining-induced seismic events This paper describes preliminary results from seismic monitoring experiments carried out in a hard rock nickel mine in Sudbury, Canada. Existing seismic monitoring instrumentation was enhanced with a low cost microcomputer-based whole waveform seismic acquisition system. Some of the signals recorded during this experiment indicate anisotropic wave propagation through the mine rock masses, as observed by the splitting of shear waves and the relative arrival of two shear waves polarized in directions which may be related to the structural fabric and/or state of stress in the rock mass. Analysis of compressional wave first motion shows the predominance of shear events, as indicated by focal mechanism studies and is confirmed by spectral analysis of the waveforms. The source parameters were estimated fro typical low magnitude localized microseismic events during the initial monitoring experiments. The seismic moment of these events varied between 106 N.m and 2.108 N.m. with a circular source radius of between 1 m and 2 m with an estimated stress drop of the order of 1 MPa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Application of singular value decomposition method for location of seismic events in mines (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 553-570 
    Details
    ISSN: 1420-9136
    Keywords: Location methods ; singular value decomposition method ; Quirke Mine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Singular Value Decomposition method of solving a linear system of equations can be successfully used for focus location when both linear and nonlinear methods are applied. This method can also be used to calculate the variance of the separate source coordinates, when the variance of the input data is known. It is also possible to optimize the geometry of a seismic network by using the condition number of the covariance matrix, and to check the set of data which is used for the focus location when some of the data are expected to be incorrect. Examples of applications of the Singular Value Decomposition method are demonstrated for linear and nonlinear methods with reference to the seismic network in Quirke Mine, Ontario, Canada.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Recognition of the zones of seismic hazard in Polish Coal mines by using a seismic method (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 609-617 
    Details
    ISSN: 1420-9136
    Keywords: Seismic hazard ; rockburst hazard ; seismic wave velocity ; stress state ; Upper Silesian coal mines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In the Upper Silesian Coal Field the seismic hazard induced by mining operations in collieries is closely related to the rockburst hazard. A seismic method is used for premonitory recognition of the zones of seismic hazard. It takes advantage of the relationship between the velocity of propagation of seismic waves and the state of stress existing in the rock. It consists of the determination of the velocity field of artificially induced seismic waves in a studied fragment of the rock, and of locating the velocity anomaly. The position of the velocity anomaly zones and their intensity are the basis for estimating the seismic hazard in advance of mining works.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874528
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Some comparisons between the middle atmosphere dynamics of the Southern and Northern Hemispheres (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 213-232 
    Details
    ISSN: 1420-9136
    Keywords: Middle atmosphere ; dynamics ; interhemispheric comparison
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Comparisons are drawn between certain middle atmosphere dynamical processes in the Southern Hemisphere and the Northern Hemisphere. Attention is focused on the zonal-mean climatological state, stationary waves, transient waves of various types, stratospheric sudden warmings and polar ozone minima. Observations of the similarities and differences between the hemispheres are mentioned, and ways in which these comparisons may be used to enhance our dynamical knowledge of the whole middle atmosphere are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874456
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    A note on some early radiosonde temperature observations in the Antarctic lower stratosphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 171-180 
    Details
    ISSN: 1420-9136
    Keywords: Antarctic lower stratosphere ; polar vortex ; springtime warming behaviour ; radiosonde temperature observations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The behaviour of the Southern Hemisphere stratosphere has attracted considerable interest, and been compared with the Northern Hemisphere, since the International Geophysical Year (1957–58) when the sudden (“explosive” or “accelerated”) springtime warming phenomenon in the Antarctic was first observed. Over the years studies of upper air temperature and wind observations have been made, principally through the spring months when the polar vortex breakdown occurs, utilising both ground-based (rawinsonde, rocket) and more recently, satellite-derived data. Although the radiosonde-derived temperature data are limited both by the number of reporting stations, and the practical difficulty of securing observations much above the 100 hPa level, useful records exist from 1956 or 1957. These have shown that in the 1959 southern spring, the lower stratosphere was relatively colder, and the warming rate through the season was essentially more regular, with little evidence of the marked but short-lived temperature fluctuations usually found. Similar, but not quite such wide-spread conditions occurred again in the 1961 spring. In another study, 30 hPa temperature fields over the Antarctic continent, which could be drawn for the 1967 spring, showed the complexity of the polar vortex breakdown. These features are recalled because extension of the 100 hPa springtime temperature series for the Australian Antarctic station at Casey (66.3°S, 110.5°E) shows that in 1985 and part of 1986, the temperature behaviour there was similar to, but not quite so extreme as that which occurred at Mirny (66.5°S, 93.0°E) in 1959.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Body force circulations in a compressible atmosphere: Key concepts (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 243-262 
    Details
    ISSN: 1420-9136
    Keywords: Mean meridional circulation ; zonally symmetric tidal theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The body force circulation problem of Eliassen is extended to spherical geometry and a quasi-compressible atmosphere using the zonally symmetric tidal theory. The concept of body force circulation is generalized to include the effects of mechanical friction and Newtonian cooling. This viewpoint is conceptually advantageous when the circulation is driven by body forces against radiative relaxation. The resulting linear theory is qualitatively useful in middle atmosphere applications, including the equatorial momentum source for which an analytic solution has not been given previously. Further generalizations of the theory are possible by including dynamical and photochemical feedback effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874458
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Radar observations of prevailing winds and waves in the Southern Hemisphere mesosphere and lower thermosphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 303-318 
    Details
    ISSN: 1420-9136
    Keywords: Mean circulation ; planetary waves ; mesosphere ; Southern Hemisphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract HF radar stations (utilizing the spaced-antenna partial-reflection technique) located at Adelaide (35°S, 138°E) and Mawson Station (67°S, 63°E) have observed horizontal mesospheric winds continuously since mid-1984. Observations in the period 1984–87 are compared with the Northern Hemisphere [latitude conjugate] stations of Kyoto (35°N, 136°E) and Poker Flat (65°N, 147°W), and with satellite-derived circulation models. Particular reference is made to the equinoctial changeovers in zonal flow and to the temporal and altitude variations in the planetary wave activity at Mawson and Adelaide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Introduction (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 1-4 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874477
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Acknowledgement (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 781-782 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881611
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    A note on multiple flow equilibria (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 743-749 
    Details
    ISSN: 1420-9136
    Keywords: Dynamic systems ; multiple equilibrium ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A set of ordinary differential equations describing a mechanical system subject to forcing and dissipation is considered. A topological argument is employed to show that if all time-dependent solutions of the governing equations are bounded, the equations admitN steady solutions, whereN is a positive odd integer and where at least (N−1)/2 of the steady solutions are unstable. The results are discussed in the context of atmospheric flows, and it is shown that truncated forms of the quasigeostrophic equations of dynamic meteorology and of Budyko-Sellers climate models satisfy the hypotheses of the theorem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881609
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Variations in geometric measures of topographic surfaces underlain by fractured granitic plutons (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 77-97 
    Details
    ISSN: 1420-9136
    Keywords: Fractures ; fractal geometry ; granite permeability ; topography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Silicate melts impose systematic fracture patterns on their hosts and their own subsolidus portions as they crystallize and cool to ambient conditions. Weathering of these plutonic bodies accentuates the fractures and produces fragmented topographic surfaces whose geometric measures exceed those of a Euclidean surface. Because geometric measures of these surfaces are potentially indicative of the percolation properties of the fracture network, contours and vertical sections were digitized from 1∶250000 and 1∶240000 scale maps, and their statistical fractal dimensions,D, were computed. Regions underlain by granitic plutons with similar fragmentation patterns were found to haveD values ranging from 1.15 to 1.28 within a single pluton. This range of values is caused by noise and several geologic factors. The values contain noise introduced by the map-making and digitizing procedures that amounts toD≈1.05. However all values lie well above this threshold, and they correlate closely with local differences in weathering. SmallerD values derive from contours where accumulation of screen or glacial erosion has smoothed the surface, whereas largerD values derive from contours along aretes and in unglaciated terrains. In each of these regions, largerD values occur locally where fractures are most frequent and/or continuous. LargeD values were also derived from regions underlain by host rocks that lie in the near-field region of the stress field caused by the pluton. The fractral values derived are apparently related to the magma-hydrothermal event, they can potentially be used to derive properties of the percolation networks that were active during the hydrothermal events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874481
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    The fractal geometry of flow paths in natural fractures in rock and the approach to percolation (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 111-138 
    Details
    ISSN: 1420-9136
    Keywords: Fractals ; fractures ; fluid flow ; percolation ; rock mechanics ; geohydrology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The distributions of contact areas in single, natural fractures in quartz monzonite (Stripa granite) are found to have fractal dimensions which decrease fromD=2.00 to values nearD=1.96 as stress normal to the fractures is increased from 3 MPa up to 85 MPa. The effect of stress on fluid flow is studied in the same samples. Fluid transport through a fracture depends on two properties of the fracture void space geometry. the void aperture; and the tortuosity of the flow paths, determined through the distribution of contact area. Each of these quantities change under stress and contribute to changes observed in the flow rate. A general flow law is presented which separates these different effects. The effects of tortuosity on flow are largely governed by the proximity of the flow path distribution to a percolation threshold. A fractal model of correlated continuum percolation is presented which quantitatively reproduces the flow path geometries. The fractal dimension in this model is fit to the measured fractal dimensions of the flow systems to determine how far the flow systems are above the percolation threshold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Empirically derived relationships between fractal dimension and power law form frequency spectra (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 211-239 
    Details
    ISSN: 1420-9136
    Keywords: Fourier analysis ; fractal ; frequency spectra ; roughness ; stationarity ; numerical modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Fractal analysis and Fourier analysis are independent techniques for quantitatively describing the variability of natural figures. Both methods have been applied to a variety of natural phenomena. Previous analytical work has formulated relationships between the fractal dimension and power law form frequency spectrum.Mandelbrot (1985) has shown that difficulties arise when the ruler method for measuring dimensionality is applied to other than self-similar figures. Since an investigator presumably does not know in advance the dimensionality of a natural profile, it is essential to quantify the nature of the discrepancy for self-affine cases. In this study, a series of experiments are conducted in which discrete random series of specified spectral forms are analyzed using the fractal ruler method. The various parameters of the fractal measurement are related to the parameters of the spectral model. In this way, empirical relationships between the techniques can be derived for discrete, finite series which simulate the results of applying the fractal method to observational data. The results of the study indicate that there are considerable discrepancies between the results predicted by theory and those derived empirically. The fundamental power law form of length versus resolution pairs does not hold over the entire region of analysis. The predicted linear relationship between fractal dimension and exponent of the frequency spectrum does not hold, and the spectral signals can be extended beyond the limits of dimension inferred by theory. Root-mean-square variability is also shown to be linearly related to the fractal intercept term. An investigation of the effect of nonstationary sampling is conducted by generating signals composed of segments of differing spectral characteristics. Fractal analyses of these signals appear identical to those conducted on stationary series. The discrepancies between theoretical prediction and empirical results described in this study reflect the difficulties of applying analytically derived techniques to measurement data. Both Fourier and fractal techniques are formulated through rigorous mathematics, assuming various conditions for the underlying signal. When these techniques are applied to discrete, finite length, nonstationary series, certain statistical transformations must be applied to the data. Methods such as windowing, prewhitening, and anti-aliasing filters have been developed over many years for use with Fourier analysis. At present, no such statistical theory exists for use with fractal analysis. It is apparent from the results of this study that such a statistical foundation is required before the fractal ruler method can be routinely applied to observational data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874488
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Fractals, fault-gouge, and friction (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 255-271 
    Details
    ISSN: 1420-9136
    Keywords: Fractals ; fault-gouge ; friction ; faulting ; stick-slip ; velocity-weakening ; self-similarity ; fractal dimension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The particle-size distribution of a natural fault-gouge has been determined over the range from 5 μm to 40 cm. The gouge is self-similar over the range from 5 μm to 1 cm having a fractal dimension of 2.60±0.11. The lower and upper fractal limits were also determined. The lower fractal limit occurs at a dimension of about 1–10 μm where mineral cleavage and intergranular porosity dominate the cataclasis. The upper fractal limit occurs at particle sizes on the order of 1 cm where the scaled particle density decreases abruptly by a factor of about three. By analogy to soil-mechanics shear box tests and laboratory rock friction experiments, it is argued that the upper fractal limit of the gouge determines the characteristic displacement parameter in stick-slip friction models. A characteristic displacement on the order of 1 cm is consistent with estimates based on numerical simulations of faulting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874490
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Geomagnetic quiet day selection (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 333-341 
    Details
    ISSN: 1420-9136
    Keywords: Quiet day ; geomagnetic indices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Based on published literature and the response to a questionnaire sent to geomagnetic field, ionospheric and magnetospheric researchers, several methods of choosing periods of quiet conditions based on geomagnetic records, as well as other observed parameters, have been identified. Caveats with respect to using geomagnetic indices to select quiet periods include the following: 1. Geomagnetic disturbances are strongly local. Even if the data from all available observatories indicate quiet behavior, there is the distinct possibility that some other location, not sampled, may be disturbed. 2. Geomagnetic indices are convenient but imperfect indicators of geomagnetic activity. Indices based on a quiet-day reference level have uncertainties comparable to the threshold value for quiet conditions. Indices representing average conditions during a 24-hr UT day may not be appropriate. 3. Geomagnetic activity does not fully reflect the range of possible factors that influence the ionosphere or magnetosphere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876832
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Least squares and integral methods for the spherical harmonic analysis of theSq-field (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 357-370 
    Details
    ISSN: 1420-9136
    Keywords: Spherical harmonic analysis ; Sq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Spherical harmonic coefficients (SHCs) for the daily magnetic variation fields (solar and lunar) and the main field of the earth are usually estimated by the method of least squares applied to a truncated spherical harmonic series. In this paper, an integral method for computing the SHCs for the solar quiet daily magnetic variation fieldSq is described and applied toSq data for May and June 1965. TheSq SHCs thus derived are then compared with the results obtained using both unweighted and weighted versions of the least squares method. The weighting used tends to orthogonalize the least squares terms. The integral and weighted least squares results agree closely for terms up to order 4 and degree 30, but both disagree considerably for the higher degree terms with the results of the unweighted least squares. Errors introduced by the numerical integration can be shown to be small, hence the disagreement between integral and unweighted least squares coefficient sets arises from improper weighting. Also, it is concluded that discrepancies between the geomagnetic northward and eastward component-derived coefficient sets arise from either time-dependent external sources that produce non-local-time, based fields or nonpotential sources and not from truncation of the spherical harmonic series as has previously been suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876834
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The contribution of magnetospheric currents toSq (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 447-462 
    Details
    ISSN: 1420-9136
    Keywords: Magnetospheric currents ; Sq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Since the discovery of the magnetosphere, it has been known that the currents flowing in the magnetosphere contribute toSq, the regular daily variation in the earth's surface magnetic field. The early models, however, were not very accurate in the vicinity of the earth. The magnetospheric contribution toSq has therefore been recalculated by direct integration over the three major magnetospheric current systems; magnetopause, tail and ring. The finite electrical conductivity of the earth, which increases the horizontal and decreases the vertical components of the magnetospheric field at the earth's surface, has been taken into account. The magnetospheric currents are found to contribute 12 nanotesla to the day to night difference in the mid-latitudeSq pattern for steady, quiet magnetospheric conditions. They also contribute to the annual variation in the surface field and must be considered an important source of the observed day to day variation in theSq pattern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876839
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    On the evolution of methods of determiningL (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 527-531 
    Details
    ISSN: 1420-9136
    Keywords: Lunar geomagnetic variations ; L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A brief description of existing methods of determiningL of geophysical elements is given in this paper. Their evolution or various modifications are briefly mentioned. It is hoped that scientific studies of lunar perturbations in geophysics and aeronomy should be encouraged and strengthened during future years.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876843
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Scattering and attenuation of elastic waves in random media (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 577-603 
    Details
    ISSN: 1420-9136
    Keywords: Elastic wave ; random media ; multiple scattering ; phase velocity and attenuation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In seismic exploration, elastic waves are sent to investigate subsurface geology. However, the transmission and interpretation of the elastic wave propagation is complicated by various factors. One major reason is that the earth can be a very complex medium. Nevertheless, in this paper, we model some terrestrial material as an elastic medium consisting of randomly distributed inclusions with a considerable concentration. The waves incident on such an inhomogeneous medium undergo multiple scattering due to the presence of inclusions. Consequently, the wave energy is redistributed thereby reducing the amplitude of the coherent wave. The coherent or average wave is assumed to be propagating in a homogeneous continuum characterized by a bulk complex wavenumber. This wavenumber depends on the frequency of the probing waves; and on the physical properties and the concentration of discrete scatterers, causing the effective medium to be dispersive. With the help of multiple scattering theory, we are able to analytically predict the attenuation of the transmitted wave intensity as well as the dispersion of the phase velocity. These two sets of data are valuable to the study of the inverse scattering problems in seismology. Some numerical results are presented and also compared, if possible, with experimental measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876265
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Elastic wave inverse scattering in nondestructive evaluation (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 715-739 
    Details
    ISSN: 1420-9136
    Keywords: Inverse scattering ; elastic wave ; nondestructive evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Ultrasonic detection and characterization of flaws in metals and ceramics is of considerable technological interest. Scattering and inverse scattering theories have recently been applied to these tasks in a systematic manner and considerable progress has resulted. This paper first reviews briefly the development of scattering and inverse scattering methods in the AF/DARPA Program in Quantitative Nondestructive Evaluation.2 Then one particular inverse method studied in that program, the inverse Born approximation, is discussed in detail. Progress is reviewed and the ability of the method to distinguish volumetric and crack-like flaws is demonstrated in simple cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876270
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    The impact of base-level analyses on stratospheric circulation statistics for the Southern Hemisphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 181-194 
    Details
    ISSN: 1420-9136
    Keywords: Southern Hemisphere stratosphere ; sensitivity of stratospheric circulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The impact of different base-level analyses on derived stratospheric circulation statistics for the Southern Hemisphere has been assessed. Three different sets of daily operational analyses of geopotential height at 100 hPa for September, 1981 have been used as the base-level analyses, combined with a single set of daily thickness analyses for the stratosphere. The circulation statistics considered include mean fields, transient eddy statistics, Eliassen-Palm flux diagnostics and vorticity fields. In general, the different base-level analyses do not change the qualitative description of the circulation statistics but they lead to marked quantitative differences, particularly at high latitudes. The statistics which are most sensitive to the different base-level analyses are those which emphasise the shortest space scales through multiple differentiation of the height field and the shortest time scales, such as daily Eliassen-Palm flux diagrams or the daily vorticity fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874454
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    A review of gravity wave saturation processes, effects, and variability in the middle atmosphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 343-371 
    Details
    ISSN: 1420-9136
    Keywords: Gravity waves ; saturation ; middle atmosphere dynamics ; turbulence ; diffusion ; momentum fluxes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This paper provides a review of our current understanding of the processes responsible for gravity wave saturation as well as the principal effects and variability of saturation in the lower and middle atmosphere. We discuss the theoretical and observational evidence for linear and nonlinear saturation processes and examine the consequences of saturation for wave amplitude limits, momentum and energy fluxes, the diffusion of heat and constituents, and the establishment of a near-universal vertical wavenumber spectrum. Recent studies of gravity wave variability are reviewed and are seen to provide insights into the significant causes of wave variability throughout the atmosphere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874464
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    A theory of enhanced saturation of the gravity wave spectrum due to increases in atmospheric stability (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 399-420 
    Details
    ISSN: 1420-9136
    Keywords: Gravity waves ; saturation ; wave breaking ; energy dissipation ; momentum flux ; mean flow acceleration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In this paper we consider a vertical wavenumber spectrum of vertically propagating gravity waves impinging on a rapid increase in atmospheric stability. If the high-wavenumber range is saturated below the increase, as is usually observed, then the compression of vertical scales as the waves enter a region of higher stability results in that range becoming supersaturated, that is, the spectral amplitude becomes larger than the saturation limit. The supersaturated wave energy must then dissipate in a vertical distance of the order of a wavelength, resulting in an enhanced turbulent energy dissipation rate. If the wave spectrum is azimuthally anisotropic, the dissipation also results in an enhanced vertical divergence of the vertical flux of horizontal momentum and enhanced wave drag in the same region. Estimates of the enhanced dissipation rates and radar reflectivities appear to be consistent with the enhancements observed near the high-latitude summer mesopause. Estimates of the enhanced mean flow acceleration appear to be consistent with the wave drag that is needed near the tropopause and the high-latitude summer mesopause in large-scale models of the atmosphere. Thus, this process may play a significant role in determining the global effects of gravity waves on the large-scale circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Wind fluctuations near a cold vortex-tropopause funnel system observed by the MU radar (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 463-479 
    Details
    ISSN: 1420-9136
    Keywords: MST radar observation ; cold vortex ; tropopause funnel ; internal gravity waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Vertical and temporal variations of three-dimensional wind velocity associated with an upper-tropospheric cold vortex-tropopause funnel system were observed by an MST radar in Japan (the MU radar). Marked changes of vertical velocity and horizontal wind direction were found between the inside and outside of the cold vortex. The vertical velocity activity outside the vortex was asymmetric; it was most active in a sector before the vortex. Unsaturated internal gravity waves in their generation stage contribute predominantly to the vertical velocity activity, suggesting that tropospheric occluded cyclones may be a possible source of middle-atmospheric gravity waves through the geostrophic adjustment process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874469
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Source mechanism of a large scale gas outburst at Sunagawa Coal Mine in Japan (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 325-343 
    Details
    ISSN: 1420-9136
    Keywords: Source mechanism ; seismic moment tensor ; gas outburst ; Sunagawa Coal Mine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract On January 29ty, 1986, the third largest gas outburst in Japan took place at Sunagawa Coal Mine, which is the only hydraulic mine in Japan. It occurred at a face of a cross-cut, just after a coal seam was outcropped by blasting for drivage of the cross-cut. The site of the gas outburst was located 1,180 m below the surface. No workers were injured, but the cross-cut was plugged with 1,600 m3 of coal fragments extending over 100 m behind the face and 60,000 m3 of methane gas was emitted. The site of the gas outburst was investigated in detail to clarify the geological features. A normal and a reverse fault existed at the site. The area of the ejected zone was about 400 m2 and extended upward along the normal fault. The shape of the ejected zone suggests a great role of the normal fault on the gas outburst. Digital seismograms, recorded by a mine-wide seismic array at the coal mine, consisting of 27 microseismic events were used to investigate the gas outburst. Magnitude, seismic energy release, distribution of hypocenter and focal mechanism were analyzed. Taking the shape of the ejected zone together with results of the seismological investigation into consideration, it appears that the seismicity started with left-lateral faulting of the reverse fault and then right-lateral faulting of the normal fault followed. The faulting of the normal fault might be the direct cause and be the predominant mechanism of the gas outburst.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Full-correlation analysis of turbulent scattering layers in the mesosphere observed by the MU radar (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 605-616 
    Details
    ISSN: 1420-9136
    Keywords: MU radar ; mesosphere ; turbulence ; scattering layer ; full-correlation analysis technique ; gravity wave ; wave breaking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We have applied a full-correlation analysis technique to the echo power fluctuations observed by the MU radar (35°N, 136°E), and analyzed the horizontal structure of the scattering pattern in the mesosphere as well as their horizontal motions. The velocity of the scattering pattern did not agree with the background wind velocity, but was associated with the horizontal propagating direction of a saturated inertia gravity wave identified in the wind field. The length of the long axis of the characteristic ellipse of the scattering pattern was approximately 50 km, and the direction was almost perpendicular to the propagating direction of the wave. The correlation time of the scattering pattern was approximately 700 s, which is much longer than the lifetime of the isolated turbulence itself. This implies that the observed scattering pattern is associated with a region where the saturated inertia gravity wave generates turbulence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874476
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    In situ thermal conductivity and equilibrium formation temperature from circulation flow rate variations (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 687-697 
    Details
    ISSN: 1420-9136
    Keywords: Thermal conductivity ; transient heat transfer ; borehole temperature logging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A temperature-transient method to estimatein situ formation thermal conductivity and equilibrium formation temperature using circulation fluid flow-rate pulses is described. Flow-rate changes induce temperature variations in the well and the time from when the flow alters to the subsequent maximum or minimum temperature of the drilling fluid can be used to determine these two formation parameters. Some examples are presented to illustrate the method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881604
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Multifractal measures, especially for the geophysicist (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 5-42 
    Details
    ISSN: 1420-9136
    Keywords: Fractal ; multifractal ; measure ; Hölder ; limit theorem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This text is addressed to both the beginner and the seasoned professional, geology being used as the main but not the sole illustration. The goal is to present an alternative approach to multifractals, extending and streamlining the original approach inMandelbrot (1974). The generalization from fractalsets to multifractalmeasures involves the passage from geometric objects that are characterized primarily by one number, namely a fractal dimension, to geometric objects that are characterized primarily by a function. The best is to choose the function ϱ(α), which is a limit probability distribution that has been plotted suitably, on double logarithmic scales. The quantity α is called Hölder exponent. In terms of the alternative functionf(α) used in the approach of Frisch-Parisi and of Halseyet al., one has ϱ(α)=f(α)−E for measures supported by the Euclidean space of dimensionE. Whenf(α)≥0,f(α) is a fractal dimension. However, one may havef(α)〈0, in which case α is called “latent.” One may even have α〈0, in which case α is called “virtual.” These anomalies' implications are explored, and experiments are suggested. Of central concern in this paper is the study of low-dimensional cuts through high-dimensional multifractals. This introduces a quantityD q, which is shown forq〉1 to be a critical dimension for the cuts. An “enhanced multifractal diagram” is drawn, includingf(α), a function called τ(q) andD q.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Fractal dimension of fault systems in Japan: Fractal structure in rock fracture geometry at various scales (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 157-170 
    Details
    ISSN: 1420-9136
    Keywords: Fracture geometry ; fractal dimension ; self-similarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Based on fault maps, whether or not the fracture geometry of rocks is self-similar, was examined by using a box-counting algorithm. The statistical self-similarity (fractal structure) of the fault fracture systems holds well at the scale of about 2 to 20 km. The fractal dimension in Japan varied from 1.05 to 1.60. The fractal dimension is about 1.5–1.6 at the central part of the Japan Arc, and decreases with distance from the center. At a smaller scale, the fractal structure also holds well in the rock fracture geometry. The fractal dimension of the North Izu Peninsula fault system (branching faults) is 1.49 at the scale of 0.625 to 10 km, the fractal dimension of rock fracture geometry at the scale order of 10−1 to 10−2 meters is about 1.49–1.61. The upper limit of the fractal dimension of rock fracture geometry is about 1.6, judging from the estimation of fractal dimension on actual fracture geometry of rocks. This value may impose a restraint on modeling of faulting and the fracture process of rocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874485
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Editorial (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 1-3 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877733
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Simple method for combined studies of macroseismic intensities and focal mechanisms (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 83-97 
    Details
    ISSN: 1420-9136
    Keywords: macroseismic data ; focal mechanism ; circular source ; energy flow ; directivity ; local effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A simple method is presented for the computation of theoretical models of the macroseismic field, approximately valid close to the epicentre of a weak crustal earthquake. It is assumed that the intensity is logarithmically proportional to the energy flux of a complete directS wave. A circular source is used, whose energy-flux directivity is weak and thus simply predictable. The focal mechanism influences the solution through standard far-field double-couple radiation patterns. For the wave propagation in the layered crust the ray method is used, and a simple absorption correction is applied. Conversion coefficients at the earth's surface are included. To speed up repeated computations of the theoretical macroseismic fields for varying focal mechanisms, the ray quantities are computed (and stored) separately. This makes the program fast and simple enough even for routine applications on small microcomputers, whenever observed macroseismic fields, focal mechanisms, and hypocentre locations need joint interpretation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877738
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Earlier days of gravity waves revisited (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 151-170 
    Details
    ISSN: 1420-9136
    Keywords: Atmospheric dynamics ; atmospheric waves ; gravity waves ; upper atmosphere ; history of atmospheric science
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The means whereby the author came to be involved in the study of atmospheric gravity waves, and then came to involve others in that study, are outlined. In particular, events leading up to, during and following the International Symposium on Fluid Mechanics in the Ionosphere, of July 1959, are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874452
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Monthly mean winds in the mesosphere at 44S and 78S (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 291-301 
    Details
    ISSN: 1420-9136
    Keywords: Mesosphere ; high latitude ; Southern Hemisphere ; partial reflection radar ; winds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A medium frequency partial-reflection spaced-antenna wind radar was installed at Scott Base (78S) on Ross Island, Antarctica, in November 1982. Results from this radar for the period December 1982 to October 1984 inclusive are compared with simultaneous measurements made with a similar radar at Christchurch (44S), N. Z. Monthly mean zonal winds measured at 80 km are compared with recent models for the Southern Hemisphere middle atmosphere. There is a general agreement with the models but there is evidence that the Christchurch winter flow was atypical in 1983.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874461
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Theory of internal gravity wave saturation (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 373-397 
    Details
    ISSN: 1420-9136
    Keywords: Internal gravity waves ; nonlinear instability ; transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Gravity wave saturation is an important process affecting the transport and deposition of momentum, heat, and constituents in the earth's atmosphere. This paper informally discusses several saturation mechanisms and their effects, including convection, Kelvin-Helmholtz instability, vortical mode instability, parametric subharmonic instability, and mean flow interaction. Convective saturation is emphasized. The parameterization of convective adjustment is discussed and a few remarks are made concerning the effects of turbulence localization on the convective saturation process. Several outstanding problems in saturation theory are identified that could be addressed with observational, numerical, and laboratory studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874465
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Pattern triplications following genetic ablation on the wing ofDrosophila (1989)
    Springer
    Development genes and evolution 198 (1989), S. 65-77 
    Details
    ISSN: 1432-041X
    Keywords: Cell communication ; Pattern formation ; Cell differentiation ; trans-regulatory genes ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects ofpolyhomeotic (ph) mutants in imaginal cells have been studied in a clonal analysis. Clones of cells, homozygous forph, sort-out after a few divisions, probably as a consequence of modified cell affinities. The dorso-ventral margin of the wing has special characteristics that retard this phenomenon. The formation and exclusion of a clone of 8–16 cells affect the polarity of the wild-type neighbour cells and can provoke pattern triplications. The results suggest that a defect in intercellular communication prevents the wild-type cells from maintaining coordinated positional information. The cells react by regenerative growth, and reorganize into a new pattern. The pleiotropic phenotypes ofph mutants are explained according to a common hypothesis aboutph + function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447741
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    The metamorphic switch in hemoglobin phenotype ofXenopus laevis involves erythroid cell replacement (1989)
    Springer
    Development genes and evolution 198 (1989), S. 57-64 
    Details
    ISSN: 1432-041X
    Keywords: Hemoglobin transition ; Erythrocytes ; Indirect immunofluorescence ; Metamorphosis ; Xenopus laevis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To elucidate the cellular basis of hemoglobin transition inXenopus laevis the distribution of larval and adult hemoglobins was analyzed by indirect immunofluorescence in the circulating erythrocytes during metamorphosis. In addition, the morphological characteristics as well as the capacity for synthesis of DNA and hemoglobin in the erythrocytes were followed during the same developmental period. Our quantitative analysis on the distribution of larval and adult hemoglobins suggests that they are localized in different cells. Hemoglobin transition, therefore, most likely reflects replacement of the larval erythrocyte population by new cells which are committed to adult globin synthesis. Since hemoglobin transition is not accompanied by an increase in the abundance of immature erythroid cells with active DNA synthesis, we assume that the presumptive adult erythroid cells are released into circulation at a relatively advanced stage of maturation. The decline in the synthesis of DNA and larval hemoglobin further indicates that cessation of cell renewal in the larval erythrocyte population may represent a decisive step in hemoglobin transition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447740
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Effects of the injection of exogenous DNAs on gene expression in early embryos and coenocytic egg cells ofXenopus laevis (1989)
    Springer
    Development genes and evolution 198 (1989), S. 78-84 
    Details
    ISSN: 1432-041X
    Keywords: DNA injection ; CAT gene expression ; Midblastula transition ; Xenopus embryogenesis ; Coenocytic egg cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary InXenopus laevis embryogenesis, the synthesis of heterogeneous mRNA-like RNA starts at the cleavage stage, whereas that of low-molecular-mass RNAs and rRNA occurs at the early blastula and late blastula stages, respectively. In coenocytic fertilizedXenopus egg cells, which fail to cleave, an excess of exogenously injected DNA (pBR322) induces ‘premature’ expression of previously injected exogenous genes (yeast tRNA genes). We have carried out experiments to discover whether the injection of excess exogenous DNAs of various origins modifies the expression of endogenous genes and previously injected exogenous genes inXenopus embryogenesis. We found that injection of a relatively large amount of exogenous DNA (Xenopus rDNA clone) induces the premature expression, or enhanced expression, of previously injected bacterial chloramphenicol acetyltransferase genes in coenocytic cells. In embryos, however, the injection of exogenous DNAs of various origins did not appreciably modify the expression of either endogenous or previously injected CAT genes. The DNAs injected into fertilized eggs were not degraded and were partitioned into the nuclei of most (at least 80%) of the descendant blastomeres at least during early stages of development. Therefore, we concluded that the program of gene expression in normally developing embryos cannot easily be altered by the introduction of excess exogenous DNAs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447742
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Elongated microvilli support the sea urchin embryo concentrically within the perivitelline space until hatching (1989)
    Springer
    Development genes and evolution 198 (1989), S. 85-91 
    Details
    ISSN: 1432-041X
    Keywords: Elongated microvilli ; Extracellular matrix ; Elastic support ; Hatching process ; Sea urchin embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The early sea urchin embryo is supported in a concentric position within the perivitelline space by elongated microvilli which are attached to the fertilization envelope by extracellular matrix fibers. This “attachment complex,” of microvillus tip: extracellular matrix fibers: fertilization envelope, was revealed by two methods: the use of pronase or calcium-free sea water to dissolve the extracellular matrix fibers, thus causing the eggs to lose their concentric location, and the visualization of the “attachment complex” using video-enhanced differential interference contrast microscopy and transmission electron microscope images. The presence of the “attachment complex” helps in understanding two types of early developmental events: (1) the apparently continual change in microvillus length during cleavage stages which retains the embryos in their concentric position and (2) the hatching process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447743
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Keratan sulfate expression during avian craniofacial morphogenesis (1989)
    Springer
    Development genes and evolution 198 (1989), S. 103-113 
    Details
    ISSN: 1432-041X
    Keywords: Morphogenesis ; Keratan sulfate ; Glycosaminoglycan ; Craniofacial morphogenesis ; Chondrogenesis ; Placodes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using the monoclonal antibody MZ15 in immunocytochemical and ultrastructural studies we have been able to determine the spatiotemporal pattern of keratan sulfate (KS) distribution during quail craniofacial morphogenesis. KS-containing proteoglycans are found associated with invaginating placodes (olfactory, lens and otic), in developing pronephric tubules, notochord, pharynx and endocardium, and display developmental regulation. The appearance of such proteoglycans (PGs) during placode morphogenesis is particularly striking and we suggest that they may be an important component of the extracellular matrix which has been previously implicated in mediating the morphogenetic interactions and cell movements occurring at these sites. The otic vesicle during stage 18–22 displays a notable asymmetric distribution of KS-containing PGs. The role that these molecules may play and the reasons for this regionalization are, as yet, unclear but it is conceivable that the distribution of proteoglycans at this stage reflects subsequent differentiative events during otocyst development. Furthermore, our ultrastructural observations indicate that over the developmental period studied (H & H stages 8–22) keratan sulfate exists in at least two proteoglycan forms. Some spatiotemporal correlation has been found to exist between the distributions of KS-containing PGs and type II collagen as previously reported by Thorogood et al. (1986). We suggest that the proteoglycan detected at such sites is cartilage-specific proteoglycan and that it plays an important role, together with type II collagen, in the “signalling” mechanism which specifies the subsequent pattern of the chondrocranium. It is proposed that this interaction at epithelio-mesenchymal interfaces in the developing head parallels the matrix-mediated tissue interaction between notochord and somites which results in the formation of the cartilaginous primordia of the vertebrae from the sclerotomes as reported by Lash and Vasan (1978).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447745
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    The ultrastructural organization of the isolated cortex in eggs ofNassarius reticulatus (Mollusca) (1989)
    Springer
    Development genes and evolution 198 (1989), S. 119-128 
    Details
    ISSN: 1432-041X
    Keywords: Egg cortex ; Molluscan egg ; Polarity ; Polar lobe ; Cytoskeleton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have studied the organization of the cortex in fertilized eggs ofNassarius reticulatus by examining rotary-shadowed whole mounts of isolated cortices in the transmission electron microscope. The following components were distinguished: (a) the plasma membrane, with clathrin-coated areas and coated pits, (b) microfilaments and microtubules, and (c) a tubulovesicular network of endoplasmic reticulum. Microfilaments were identified by labeling with heavy meromyosin, and microtubules with a monoclonal anti-tubulin antibody, using both immunofluorescence microscopy and immunogold labeling for transmission electron microscopy. The microfilaments are organized in a network parallel to and closely associated with the plasma membrane, with typical Y- and X-shaped intersections. The endoplasmic reticulum is associated with this microfilamentous lattice. The microtubules also run parallel to the plasma membrane, but they are located at a greater distance, as can be inferred from stereo images. In the uncleaved egg, numerous microtubules are present in the egg cortex. Shortly before polar lobe formation, at the onset of mitosis, the microtubules disappear almost entirely. They reappear again at the end of first cleavage, as the polar lobe is being resorbed. The synthesis of cortical microtubules at this stage appears to depend on the presence of microtubule-organizing centers in the animal hemisphere of the egg, since microtubules do not reappear in isolated polar lobes. Clathrin-coated areas are present in both the animal and vegetal hemisphere before polar lobe formation. During mitosis, the clathrin-coated plaques and pits are found almost exclusively in the animal hemisphere. After resorption of the polar lobe, at the two-cell stage, no clathrin-coated areas were found at all.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438936
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Removal of the polar lobe leads to the formation of functionally deficient photocytes in the annelidChaetopterus variopedatus (1989)
    Springer
    Development genes and evolution 198 (1989), S. 129-136 
    Details
    ISSN: 1432-041X
    Keywords: Bioluminescence ; Polar lobe ; Spiralian development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The light emitting photocytes ofChaetopterus variopedatus larvae are bilaterally situated within the ectoderm of the post-trochal region. Their histological appearance is similar to that of the adult photocytes. The larval photocytes contain a large quantity of membranous secretory vesicles (photosomes), which probably contain the photoluminescent protein. The two-cellChaetopterus embryo contains a small AB and a large CD blastomere. Previous studies have shown that only the “larvae” resulting from isolated CD blastomeres are able to luminesce. Consistent with these findings, morphologically distinct photocytes are only found in the CD larvae. The removal of the small polar lobe that forms during first cleavage leads to the production of a “larva” that is unable to produce light. All delobed larvae contain morphologically distinct photocytes, which are identical to those in normal larvae except they appear to contain only a small quantity of photosomes. Experimental equalization of first cleavage leads to the production of a double embryo. While photocytes are found in both of the duplicated post-trochal regions, usually only one of these is capable of emitting luminescence. Apparently, the highly localized vagetal material (determinants) responsible for functional light emission is distributed to both halves in only a few cases when first cleavage is experimentally “equalized”. These results indicate that the determinative action of the polar lobe is not required for the formation of the photocytes themselves, but rather for their ability to function as emitters of light. The determinants in the polar lobe ofChaetopterus may control some aspect of the photoluminescence reaction itself, such as the production of the photoprotein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438937
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Mutations in thespalt gene ofDrosophila cause ectopic expression ofUltrabithorax andSex combs reduced (1989)
    Springer
    Development genes and evolution 198 (1989), S. 137-140 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila embryo ; Spalt gene ; Homeotic gene expression ; Polycomb group
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary spalt is a gene required for head and tail development in theDrosophila embryo. When mutated it produces homeotic transformations which are restricted in the embryonic cuticle to both ends of the embryo. However analysis of the distribution of its transcripts has shown that it is also expressed in the trunk region of the embruo. Here I show that two homeotic genesUltrabithorax (Ubx) andSex combs reduced (Scr) can be ectopically expressed in the trunk region of embryos lackingspalt gene function. These results suggest thatspalt has a general role in ensuring the correct spatial expression of other homeotic genes and hence could be another member of thePolycomb class of regulatory genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438938
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Immunocytochemical evidence for the presence of two domains in the plasma membrane of sea urchin blastomeres (1989)
    Springer
    Development genes and evolution 198 (1989), S. 179-184 
    Details
    ISSN: 1432-041X
    Keywords: Egg membrane ; Polarity ; Blastomere ; Sea urchin ; Immuno-electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The blastomeres of sea urchin embryos have two surface regions with different properties. Numerous microvilli are present in the apical surface region, while the baso-lateral surface region, either on adjoining adjacent cells or facing the blastocoel, is smooth. When blastomeres are isolated from embryos and stained with fluorescein-isothiocyanate-labelled anti-(egg surface) antibody (anti-ES) prepared against membranes isolated from fertilized eggs, the apical microvillous region fluoresces while the smooth region does not [Yazaki I (1984) Acta Embryol Morphol Exp 5∶3–22]. In order to study quantitatively the ‘bindability’ of the membrane in the two regions to anti-ES, immunoelectron microscopy was used. Blastomeres isolated from embryos ofHemicentrotus pulcherrimus at the eight-cell stage were treated with rabbit anti-ES serum or pre-immune serum and then with ferritin-conjugated goat anti-(rabbit IgG) for 10 min at 0°C, mainly before fixation. About 10 times (maximally 45 times) more ferritin particles were counted per contour length in the microvillous surface region than in the smooth surface region. These results suggest that the membrane of the blastomeres of sea urchin embryos is a mosaic of two different membrane territories: one represented by the microvillous surface originating from the unfertilized egg, which binds anti-ES, the other by the smooth surface newly organized after the first cleavage, which does not react with anti-ES. The mechanism of segregation of the membrane into these two regions is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438943
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Use of BRL-conditioned medium in combination with feeder layers to isolate a diploid embryonal stem cell line (1989)
    Springer
    Development genes and evolution 198 (1989), S. 48-56 
    Details
    ISSN: 1432-041X
    Keywords: Embryonal stem cells ; Conditioned medium ; Feeder layer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The derivation of a karyotypically normal embryonal stem (ES) cell line, E14, from inner cell masses (ICMs) isolated by immunosurgery from 129/Ola late mouse blastocysts is described. Disaggregated ICMs were cultured on mitotically-arrested fibroblast feeder layers in droplets of medium conditioned with Buffalo rat liver (BRL) cells under oil. BRL-conditioned medium inhibits the differentiation of established embryonal carcinoma (EC) and ES cell lines which can be maintained indefinitely in the complete absence of feeder cells (Smith and Hooper 1987). At clonal densities, however, a combination of BRL-conditioned medium and a feeder layer was most effective in preventing the differentiation of E14 cells. This effect was less pronounced at higher passage suggesting it may be particularly important to use a combination in the early stages of isolation. Once established, E14 has been maintained in BRL-conditioned medium alone. In non-conditioned medium on agarose, E14 cells formed embryoid bodies which when allowed to reattach differentiated into a wide variety of tissues. An HPRT-deficient sub line of E14, E14TG2a, has been demonstrated to form germline chimaeras with high efficiency after injection into blastocysts (Hooper et al. 1987). The modifications to the ES cell isolation procedure described here may improve the efficiency with which karyotypically normal lines can be derived.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Cell surface proteins of wholeXenopus embryos identified by radioiodination (1989)
    Springer
    Development genes and evolution 198 (1989), S. 141-147 
    Details
    ISSN: 1432-041X
    Keywords: Cell surface ; Glycoproteins ; Xenopus Oocytes ; Embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have examined the proteins ofXenopus whole oocytes and embryos that are accessible to surface iodination. These cell surface proteins appear to undergo stagespecific modulation during development. The most pronounced changes were observed between oocytes and the 32-cell stage when the number of labelled proteins doubled, and between early and late gastrula when the complexity declined by two thirds. The simplification of the pattern during gastrulation may reflect changes in cell position as endodermal cells move inside leaving ectodermal cells at the external surface. The lectin binding patterns for NP-40 solubilized proteins extracted from oocytes and embryos also changed in a stage-dependent manner. Con A and WGA recognized a complex pattern of glycoproteins containing glucose and mannose residues. In contrast, SAB and RCA binding to galactose residues recognized far fewer glycoproteins. Many of the observed changes occurred during cleavage stages before embryonic gene transcription is initiated and may be due to post-translational modifications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438939
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Proximal-distal pattern formation inDrosophila: graded requirement forDistal-less gene activity during limb development (1989)
    Springer
    Development genes and evolution 198 (1989), S. 157-169 
    Details
    ISSN: 1432-041X
    Keywords: Distal less ; Limb development ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of all of the adult limbs inDrosophila depends upon the activity of theDistal-less gene. We report here the phenotypic characterization of a number of hypomorphicDistal-less alleles which indicates that there is a graded requirement forDistal-less activity in the developing limbs. Previous analysis of genetically mosaic animals indicated that cells in the early primordia of the limb imaginal dises possess a graded proximal-distal positional information which depends on the presence of theDistal-less gene for its expression. Taken together these data suggest thatDistal-less may directly encode the graded positional information that is required to organise the proximal-distal axis of the developing limbs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438941
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Organisation and assembly of the surface membrane during early cleavage of the mouse embryo (1989)
    Springer
    Development genes and evolution 198 (1989), S. 170-178 
    Details
    ISSN: 1432-041X
    Keywords: Membrane assembly ; Mouse embryo ; Cleavage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An attempt was made to understand the ways in which ‘newly inserted’ membrane was organised in relation to existing membrane during early cleavage of the mouse embryo by (i) monitoring the redistribution of a variety of surface-binding ligands (applied to the embryo during the previous cell cycle) and (ii) analysing the localisation of newly synthesised lipid at defined stages during the second cell cycle. The membrane dynamics of the embryo appear similar to those of somatic cells during cytokinesis and/or motility, and are consistent with previous suggestions (Pratt 1985) that the main cytocortical domains of the polarised 8-cell blastomere may start to diverge during early cleavage as a result of localised assembly and reorganisation of the embryo cytocortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438942
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Expression of circular and linearized bacterial chloramphenicol acetyltransferase genes with or without viral promoters after injection into fertilized eggs, unfertilized eggs and oocytes ofXenopus laevis (1989)
    Springer
    Development genes and evolution 198 (1989), S. 148-156 
    Details
    ISSN: 1432-041X
    Keywords: Xenopus egg ; DNA microinjection ; Concatemer formation ; CAT enzyme assay ; Enhancer-promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Circular and linearized plasmids containing bacterial chloramphenicol acetyltransferase (CAT) genes connected or not connected to viral promoters were injected into fertilized eggs, unfertilized eggs and oocyte nuclei ofXenopus laevis, and CAT enzyme expression was studied under different conditions. Circular DNAs injected into fertilized eggs did not change their molecular form greatly, but CAT enzyme activity was expressed by the blastula or gastrula stage depending on the strength of the enhancer contained within the promoter. Linearized plasmid DNAs injected into fertilized eggs were concatemerized and replicated extensively by the blastula stage, and were expressed also actively irrespective of whether DNAs contained the promoter or not. The CAT enzyme activity was roughly comparable to the level of CAT mRNA in injected embryos. Similar results were obtained for both circular and linearized DNAs in unfertilized eggs, although the level of CAT enzyme expressed here was quite low. In oocyte nuclei, by contrast, only circular DNAs were expressed, and the expression was independent of whether or not the DNAs contained the promoter. The large concatemers formed in embryos comigrated with host DNA, but the majority of them disappeared later, at the tadpole stage, suggesting the extrachromosomal nature of these DNAs. The pronounced decrease in the amount of comigrating DNAs was accompanied by the disappearance of both CAT mRNA and enzyme activity. Therefore, we conclude that active CAT enzyme expression induced by injection of linearized DNAs in embryos and early stage larvae is due mainly to transcription from the transiently existing extra-chromosomal concatermers rather than from long-lasting, probably genome-integrated DNAs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02438940
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Follicle cell development is partly independent of germ-line cell differentiation in Drosophila oogenesis (1989)
    Springer
    Development genes and evolution 198 (1989), S. 185-190 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Oogenesis ; Follicle cells ; Egg shell ; Ovarian tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental potential of the cells of the somatic follicular epithelium (follicle cells) was studied in mutants in which the differentiation of the germ-line cells is blocked at different stages of oogenesis. In two mutants, sn 36a and kelch, nurse cell regression does not occur, yet the follicle cells around the small oocyte continue their normal developmental program and produce an egg shell with micropylar cone and often deformed operculum and respiratory appendages. Neither the influx of nurse cell cytoplasm into the oocyte nor the few follicle cells covering the nurse cells are apparently required for the formation of the egg shell. In the tumor mutant benign gonial cell neoplasm (bgcn) the follicle cells can also differentiate to some extent although the germ-line cells remain morphologically undifferentiated. Vitelline membrane material was synthesized by the follicle cells in some bgcn chambers and in rare cases a columnar epithelium, which resembled morphologically that of wild-type stage-9 follicles, formed around the follicle's posterior end. The normal polarity of the follicular epithelium that is characteristic for mid-vitellogenic stages may, therefore, be established in the absence of morphologically differentiating germ-line cells. However, the tumorous germ-line cells do not constitute a homogeneous cell population since in about 30% of the analyzed follicles a cell cluster at or near the posterior pole can be identified by virtue of its high number of concanavalin A binding sites. This molecular marker reveals an anteroposterior polarity of the tumorous chambers. In follicles mutant for both bgcn and the polarity gene dicephalic the cluster of concanavalin A-stained germ-line cells shifts to more anterior positions in the follicle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00375904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Localization of urokinase-type and tissue-type plasminogen activator mRNA during organogenesis in the mouse (1989)
    Springer
    Development genes and evolution 198 (1989), S. 219-226 
    Details
    ISSN: 1432-041X
    Keywords: Plasminogen activators ; Mouse embryo ; In situ hybridization ; Organogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cryostat sections of E8.5 to E9.5 mouse embryos were hybridized with 35S-labelled RNA probes to urokinase-type and tissue-type plasminogen activator (uPA and tPA, respectively) mRNA. The sections were screened for expression of either gene. Two main features emerge from the results. (a) The stage of initial detection is different for each transcript. The uPA mRNA is first detected in cephalic mesenchyme at E8.5 when tPA mRNA is already widely distributed in tissues derived from ectoderm and mesoderm; later, the uPA mRNA transcripts were found throughout most mesodermic tissues, (b) Each gene presents a different pattern of expression. The uPA is restricted to single cells or to small groups of cells within tissues; this distribution suggests its involvement in cell migratory mechanisms. On the other hand, tPA was detected in most tissues, with variable intensities. Its expression gains complexity while organogenesis proceeds. This pattern supports the hypothesis that regulatory mechanisms other than a direct gene regulation are involved. In extraembryonic tissues, uPA and tPA genes are constantly expressed at a high level in trophoblastic giant cells and parietal endoderm, respectively. Our results confirm the presence of plasminogen activator during embryonic development and provide detailed picture of the plasminogen activator gene expression in mouse organogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00375908
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Influence of reproductives on tunnelling behaviour inKalotermes flavicollis Fabr. (Isoptera: Kalotermitidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 70-73 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume On a isolé des groupes deK. flavicollis de leur colonie afin d'étudier leur manière de creuser un nouvel abri, dans le mélange agar/sciure. Dès le premier jour les insectes ont creusé plusieurs galeries, puis les creusements ont été effectués avec grande régularité. Enfin, quelques galeries ont été comblées de fragments de bois. Il existe une corrélation entre la longueur des galeries comblées et la longueur de celles qui ont été creusées. La présence des sexués stimule l'activité des insectes dès le premier jour et ceux-ci creusent des nids plus vastes constitués d'un nombre plus élevé de galeries.
    Notes: Summary Groups ofKalotermes flavicollis were isolated from their wild colony, in order to study their digging of a new shelter in a mixture of agar/sawdust. On the 1st day the insects dug a lot of tunnels, and then the digging went on with great regularity. Some tunnels were later filled with sawdust. There is a correlation between the total length of the dug tunnels and that of the filled ones. The reproductives stimulated the insects' activity right from the beginning and so the latters dug wider nests made of longer tunnels and with more branches too.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225882
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Social Organization in reactivated nests of three species ofXylocopa (Hymenoptera, Anthophoridae) in southeastern Brasil (1989)
    Springer
    Insectes sociaux 36 (1989), S. 92-105 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Wir haben das Zusammenleben von meheren Weibchen in Nestern vonXylocopa suspecta, X. frontalis undX. grisescens, den häufigsten Arten in der Region von Ribeirão Preto, S.P., Brasilien, untersucht. Nahrungssammeln und Fortpflanzung der Weibchen wurde als Maß für das Sozialverhalten gewertet. Die Bildung einer Gemeinschaft begann am Ende des biologischen Zyklus', wenn die Nester erneut benutzt wurden. Zu Beginn bestanden die Gemeinschaften aus der Mutter und ihren Töchtern. Anschließend waren nur die Töchter im Nest, von denen eine, gewöhnlich das älteste Weibchen, Eier legte (erste Phase). Im nächsten Stadium waren zwei oder mehr Weibchen in der Lage, Eier zu legen; sie versorgten gemeinsam dieselben Zellen mit Nahrung und legten Eier. In der dritten Phase legten alle Weibchen Eier, jede versorgte aber ihre eigenen Zellen. Das Sozialverhalten in der ersten Phase wird als semisozial, das Verhalten in der zweiten Phase als quasisozial angesehen. Diese Verhaltensmuster traten jedoch nur vorübergehend auf, denn im letzten Stadium zeigten die Weibchen ein kommunales Sozialverhalten.
    Notes: Summary We have investigated the occurrence of cohabitation of several females in the same nest ofXylocopa suspecta, X. frontalis andX. grisescens which are the most common species in the region of Ribeirão Preto, S.P., Brazil. The study of social behaviour of these species involved, as a general procedure, the identification of each associated female in relation to its foraging and reproductive activity. It was observed that in each species the association of females started at the final phase of the biological cycle, when the reactivation of the nests began. Initially the association was observed to occur among mother and daughters. Subsequently only daughters remained in the nest and in the first phase of this association only one female (generally the eldest), was able to realize oviposition. Next, two ore more females were in the same condition, provisioning and ovipositing in only one cell. In the third phase the females had all the same condition, each one of them provisioning and ovipositing in their own cells. So, in the first and second phases the social behaviour corresponds to the semisocial and quasisocial levels, respectively. Nevertheless, this behaviour was transitory and the final pattern attained was communal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Usurpation and nest rebuilding inPolistes riparius: Two ways to reproduce after the loss of the original nest (Hymenoptera: Vespidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 116-128 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Dans une population de la guêpe monogyne,Polistes riparius, le nid est parfois usurpé par une fondatrice étrangère dont le nid a été détruit avant l'apparition des ouvrières. La probabilité de l'usurpation est 0.11–0.23 en phase de pré-émergence. La fondatrice qui n'a pas encore d'ouvrières reconstruit rarement le nid détruit, tandis que celle qui est accompagnée d'ouvrières le reconstruit fréquemment. Par suite, il semble que la fondatrice tente d'usurper ou de prendre possession du nid d'une autre quand son propre nid est détruit avant l'apparition d'ouvrières; au contraire, après leur apparition, elle tente de reconstruire le nid détruit avec ses propres ouvrières. Environ 70% des nids détruits en sous-phase de pré-mâle sont reconstruits, et environ 70% des nids ainsi reconstruits produisent une moyenne de 10–20 imagos reproducteurs, tandis que des nids ordinaires en produisent 60–90. Les usurpatrices détruisent, en moyenne, 80% des œufs et 40% des jeunes larves des fondatrices précédentes pendant 5 jours. Environ 20% des usurpatrices réussit à produire des reproducteurs. Les autres ne produisent aucun imago: la cause de l'échec la plus importante est la destruction de leur couvain par des ouvrières des fondatrices précédentes. On discute l'usurpation des nids établis et la reconstruction du nid détruit du point de vue des tactiques alternatives pour la fondatrice.
    Notes: Summary In a population of the haplometrotic paper waspPolistes riparius, a nest is sometimes usurped by a foundress who has lost its nest before worker emergence. Probability of a nest's being usurped during the pre-emergence stage was 0.11–0.23. Foundresses who did not yet have workers rarely rebuilt destroyed nests, while those with workers frequently did so. Therefore, it seems that a foundress tends to usurp another's nest if her original nest is destroyed before worker emergence, whereas she rebuilds it if her workers have already emerged. About 70% of nests which were destroyed in the pre-male substage were rebuilt, and about 70% of the rebuilt nests produced a mean of 10–20 reproductives of both sexes as compared to 60–90 for non-destroyed nests. On average, usurping foundresses destroyed 80% of the eggs and 40% of the young larvae of the previous queen during 5 days. About 20% of the usurpers succeeded in producing reproductive offspring. Others failed in reproduction. The most important cause of failure was destruction of their broods by workers of the previous foundresses. Usurpation of established nests and nest rebuilding are discussed in terms of alternative tactics of the foundress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Queen polymorphism inLeptothorax spec. A: Its genetic and ecological background (Hymenoptera: Formicidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 139-155 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Königinnepolymorphismus der nicht-parasitischen AmeisenartLeptothorax spec. A wird genetisch, wahrscheinlich durch ein Allelpaar E/e, kontrolliert. E unterdrückt dabei in weiblichen Larven die Entwicklung von Flügeln, Ocellen und Thoraxnähten, nur ee-Larven können zu geflügelten, gynomorphen Jungköniginnen heranwachsen. EE-und Ee-Königinnen sind immer intermorph. Die Häufigkeit intermorpher Königinnen im Freiland variiert von Population zu Population: in den homogenen, lichten Nadelwäldern Süd/und Zentralquebecs überwiegt die Gynomorphe, in inselartig beschränkten Biotopen, wie auf den Felsflächen am Lorenzstrom, dominieren intermorphe Weibchen. Unterschiedlicher Erfolg der beiden Morphen in den verschiedenen Biotopen wird angenommen.
    Notes: Summary Queen polymorphism in the non-parasitic ant,Leptothorax spec. A, is most probably genetically mediated by a pair of alleles E/e. E suppresses the development of wings, thoracic structures and ocelli in female larvae. Only ee-larvae may grow to gynomorphic, winged queens, EE- and Ee- larvae develop into intermorphic, wingless queens. The frequency of intermorphic queens varies widely in different habitats. Whereas in homogeneous coniferous forests throughout southern and central Quebec the gynomorph is abundant, in patchily distributed rocky outcrops along the St. Lawrence River intermorphic queens predominate. We suggest a different dispersal success of the two morphs in the various habitats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225909
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    The inoculation of newly formed fungus comb withTermitomyces inMacrotermes colonies (Isoptera, Macrotermitinae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 328-338 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume ChezMacrotermes le substrat des meules à champignon nouvellement formées est inoculé dès le début par des conidies viables deTermitomyces (spores asexuées) qui garantissent la prolifération accélérée du champignon symbiotique. Le substrat est de la matière végétale ayant traversé rapidement l'intestin des jeunes ouvriers, c'est-à-dire les constructeurs de meules et les nourrices. Ces insectes ingèrent la matière végétale recueilie par les fourrageurs et se nourrissent aussi des mycotêtes nutritives produites par le champignon. Ces mycotêtes contiennent les conidies qui sont adaptées à résister au passage à travers l'intestin où elles se mélangent avec le substrat.
    Notes: Summary The substrate of newly constructedMacrotermes fungus combs is inoculated from the start with viableTermitomyces conidia (asexual spores) which guarantee fast proliferation of the symbiotic fungus. The substrate is vegetable matter which has passed rapidly through the intestine of the young workers which are comb-builders and nurses. These ingest the vegetable matter which has been collected by the foragers and also feed on the nutrient enriched nodules produced by the fungus. These nodules contain the adaptive gut-resistant conidia which are mixed with the intestinal substrate on this pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224884
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    A new aspect of the role of larvae in the pharaoh's ant society (Monomorium pharaonis (L.)-Formicidae, Myrmicinae): Producer of fecundity-increasing substances to the queen (1989)
    Springer
    Insectes sociaux 36 (1989), S. 313-327 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume L'observation — en évitant toute perturbation — du couvain de la fourmi du Pharaon, a permis de constater que les reines fécondées et matures, sélectionnent régulièrement de grosses larves au fond du nid. De toute évidence les reines obtiennent des sécrétions liquides en léchant différentes parties de ces larves. Il s'agit surtout de sécrétions buccales provenant sans doute des glandes labiales des larves, mais aussi de sécrétions anales et de sucs intestinaux provenant de larves au stade prénymphal en train d'expulser le méconium. Afin d'étudier l'importance de ce comportement, on a compté le nombre d'œufs pondus par des reines ayant ou non accès aux larves et on a disséqué des reines et quelques ouvrières pour observer les différences. La production des reines sans larves chute immédiatement au tiers de ce qu'elle est chez des reines ayant accès aux larves; on peut rétablir la ponte de ces reines à son niveau antérieur en leur ajoutant des larves; les résultats des dissections vont dans le même sens. Il paraît vraisemblable que les reines matures et fécondées de cette espèce reçoivent la plus grande part de leur nourriture directement des larves.
    Notes: Summary Observations of undisturbed brood chambers of the pharaoh's ant showed that mated, mature queens regularly selected large larvae lying on the bottom of the chambers. The queens obviously obtained liquid secretions by licking various parts of these larvae. It was mainly stomodeal secretion, most likely originating from the larval labial glands, but also anal secretion and gut liquid from larvae becoming prepupae on shedding the meconium. In order to study the significance of this behaviour, the egg-yield of queens with or without access to larvae was counted and dissections of queens and some workers were made to observe the differences. The egg-yield of queens without larvae almost immediately dropped to about one third of the production in queens with larvae, and a high rate of egg production could be restored by introducing larvae to queens which had been depleted of larvae, in agreement with observations in the dissections. It seems likely that the mated mature queens of this species obtain most of their food directly from the larvae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224883
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    The self-organising clock pattern ofMessor pergandei (Formicidae, Myrmicinae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 339-347 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume On présente un modèle simple de choix du secteur de fourragement par des fourmis. Ce choix se fait en fonction de la quantité de phéromone associée à chaque secteur, et est autocatalytique puisque les fourrageuses qui trouvent de la nourriture dans un secteur y ajoutent de la phéromone. Quand la nourriture d'un secteur est épuisée, les fourrageuses transfèrent spontanément leur activité vers le secteur adjacent. Si la richesse en nourriture augmente, le modèle passe d'un fourragement aléatoire à la formation d'une piste qui tourne autour du nid. Plus la richesse est élevée, plus la piste tourne lentement, jusqu'à devenir figée en un secteur. Ces résultats correspondent aux observations faites sur la fourmiMessor pergandei parBernstein (1975),Rissing etWheeler (1976). reconcilient une apparente contradiction entre eux.
    Notes: Summary A simple model is described wherein ant foragers choose a foraging sector as a function of the pheromone concentration associated with each sector. The choice is autocatalytic, as foragers that find food in a sector add to its pheromone. As a sector's food runs out, the foragers spontaneously switch to the adjacent sector. With increasing food abundance, the model passes from random foraging to the formation of a trail that rotates about the nest. The greater the abundance the more slowly the trail rotates until it finally becomes fixed on one sector. These results agree with experimental observations made on the harvester antMessor pergandei byBernstein (1975) andRissing andWheeler (1976), and reconcile an apparent contradiction between them.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224885
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Soldier production inCamponotus novaeboracensis during colony growth (1989)
    Springer
    Insectes sociaux 36 (1989), S. 28-41 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Dans des colonies d'importance différente chez la fourmi charpentièreCamponotus novaeboracensis, on a observé des changements dans les équations allométriques, les courbes de fréquence de taille et la distribution des castes. Les colonies naturelles ont été groupées en trois catégories selon le nombre d'ouvrières dans une colonie: colonie «juvénile» pour moins de 150 ouvrières, colonie «prémature» pour 200 à 2000 ouvrières et colonie «mature» pour plus de 2000 ouvrières et ayant produit des sexués. Il n'y avait pas de différence dans les équations allométriques entre les trois catégories, néanmoins les colonies «matures» contenaient un plus grand nombre de soldats. On a noté des différences notables dans les courbes de fréquence de taille des trois catégories.
    Notes: Summary Changes in allometry equations, size-frequency curves, and caste ratios were examined in different-sized colonies of the polymorphic carpenter antCamponotus novaeboracensis. Field collected colonies broadly grouped into three categories based on the number of workers in a colony: “incipient” if they had fewer than 150 workers, “juvenile” if they had 200 to 2,000 workers, and “mature” if they had more than 2,000 workers and had produced reproductives. There was no difference in the allometry equations between the three groups, but the mature colonies did contain a higher proportion of soldiers. The size-frequency histograms and caste ratios were significantly different between the three groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225878
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Nest sharing, nest switching, longevity and overlap of generations inCerceris antipodes (Hymenoptera: Sphecidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 42-50 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Weibchen vonCerceris antipodes Smith benutzten am Anfang der Brutsaison selten gemeinsam ein Nest, jedoch überwogen solche Gemeinschaftsnester während der meisten Zeit des Sommers. Adulte Weibchen überwinterten und waren im nächsten Sommer für 90 Tage aktiv. Die Lebensdauer der Elterngeneration reichte bis in die Fortpflanzungszeit der Tochtergeneration. Beide Generationen überwinterten, und die Weibchen der Sommergeneration lebten relativ lange verglichen mit anderen Spheciden-Arten. Zahlreiche Nester wurden von Weibchen zweier Generationen gemeinsam benutzt. Vermutlich benutzten nicht nur verwandte Weibchen Nester gemeinsam, da bis zu 25% der Weibchen die Nester wechselten; jedoch wurden einige Nester von Müttern und ihren Töchtern gemeinsam bewohnt.
    Notes: Summary Shared nests ofCerceris antipodes Smith were infrequent early in the nesting season but most nests were shared during most of the summer. Adult females overwintered and then were active for up to 90 days the next summer. Their lives overlapped those of their adult daughters. Both overwintered and first summer generation females were long-lived compared to other sphecids and many nests were shared by females of two generations. Up to 25% of females switched nests, suggesting that not all nests were shared by relatives, although some were presumably shared by mothers and daughters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225879
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Chimaeridris, a new genus of hook-mandibled myrmicine ants from tropical asia (Hymenoptera: Formicidae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 62-69 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die neue GattungChimaeridris, mit den neuen ArtenC. boltoni aus Sulawesi undC. burckhardti aus Sabah werden beschrieben. Die Arbeiterin ist äusserlich einerPheidole sehr ähnlich, mit Ausnahme ihrer hakenförmigen Mandibeln, deren Form oberflächlich denen vonCheliomyrmex und von einigen afrikanischen Treiberameisen der GattungDorylus gleicht. Es ist möglich dassChimaeridris eine Sklavenräuberin ist (vielleicht mitPheidole Sklaven), oder eine spezialisierte Jägerin.
    Notes: Summary A description is given of the new genusChimaeridris, comprising the new speciesC. boltoni of Sulawesi andC. burckhardti of Sabah. The worker is outwardly similar to that of a minor worker or minor-major intermediate ofPheidole, except that its mandibles are hook shaped, displaying a form unique within the subfamily Myrmicinae and superficially similar to that of ecitonine army ants in the genusCheliomyrmex and some African driver ants of the genusDorylus. The possibility is raised thatChimaeridris is either a slavemaker (presumably, ofPheidole) or a specialized predator.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225881
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Trajets d'approvisionnement a partir d'un nid central chez la fourmiSerrastruma lujae (Formicidae: Myrmicinae) (1989)
    Springer
    Insectes sociaux 36 (1989), S. 51-61 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The movements ofS. lujae worker ants were analysed under experimental conditions approximating those of the African rain season (humidity at saturation point), using a correlated random walk model developed by one of the authors. With this model it is possible to account for random movements and to quantify the sinuosity of an animal's path in terms of an index which is affected neither by the length of the paths nor by the accuracy with which they have been recorded. Foraging workers on leaving the nest take a very sinuous path to which the random walk model can be applied. After capturing an item of prey, the ant takes a very direct path back to the nest. These findings are in agreement with a previous central place foraging model in which the ants' exploratory paths were taken to be erratic and their return paths direct.
    Notes: Resume Nous avons analysé les déplacements des ouvrières deS. lujae dans des conditions expérimentales reproduisant celles de la saison des pluies en Afrique (humidité à saturation) et en utilisant le modèle de la randonnée développé par l'un de nous. Ce modèle, qui permet de rendre compte des déplacements de type aléatoire, permet de quantifier la sinuosité d'un déplacement par un indice ne dépendant ni de la longueur des trajets ni de la précision avec laquelle ils ont été relevés. Les ouvrières chasseuses présentent dès leur sortie du nid un trajet exploratoire très sinueux auquel le modèle de la randonnée est applicable. Après capture d'une proie, le retour au nid est très direct. Ces résultats sont en accord avec un modèle d'approvisionnement autour d'un nid central dans lequel les trajets exploratoires sont erratiques et les retours directs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Introduction to subduction zones (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 1-5 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Generalised scale invariance and multiplicative processes in the atmosphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 57-81 
    Details
    ISSN: 1420-9136
    Keywords: Scale invariance (scaling) ; (multi-) fractal ; nonlinear variability ; turbulence ; geophysics ; atmosphere ; multiplicative processes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Many geophysical fields show highly intermittent fractal structures spanning wide ranges of scale. However, few are isotropic: “texture”, stratification, as well as variable (scale dependent) orientation of structures is far more common. To deal with such fractals, we must generalise the idea of scale invariance beyond the familiar self-similar (or even self-affine) notions. Taking the atmosphere as our primary example (however, we also model galaxies), we outline the necessary formalism (generalised scale invariance), and show how it can be used to deal with the strongly intermittent structures which result from multiplicative (cascade type) processes concentrating matter or energy into smaller and smaller scales. We illustrate these ideas with rain data from blotting paper and radar, showing first how to directly estimate the elliptical dimension characterising the stratification, and second, how to determine universal scale-independent (invariant) codimension functions that characterise the distribution of the intense rain regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877737
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    On the initiation of subduction zones (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 7-25 
    Details
    ISSN: 1420-9136
    Keywords: Initiation of subduction ; passive to active margin transition ; preservation of back-arc basins ; emplacement of ophiolites ; mechanics of plate boundary formation ; Wilson cycle ; plate reorganizations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Analysis of the relation between intraplate stress fields and lithospheric rheology leads to greater insight into the role that initiation of subduction plays in the tectonic evolution of the lithosphere. Numerical model studies show that if after a short evolution of a passive margin (time span a few tens of million years) subduction has not yet started, continued aging of the passive margin alone does not result in conditions more favorable for transformation into an active margin. Although much geological evidence is available in supporting the key role small ocean basins play in orogeny and ophiolite emplacement, evolutionary frameworks of the Wilson cycle usually are cast in terms of opening and closing of wide ocean basins. We propose a more limited role for large oceans in the Wilson cycle concept. In general, initiation of subduction at passive margins requires the action of external plate-tectonic forces, which will be most effective for young passive margins prestressed by thick sedimentary loads. It is not clear how major subduction zones (such as those presently ringing the Pacific Basin) form but it is unlikely they form merely by aging of oceanic lithosphere. Conditions likely to exist in very young oceanic regions are quite favorable for the development of subduction zones, which might explain the lack of preservation of back-arc basins and marginal seas. Plate reorganizations probably occur predominantly by the formation of new spreading ridges, because stress relaxation in the lithosphere takes place much more efficiently through this process than through the formation of new subduction zones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874622
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Estimation of strong ground motions from hypothetical earthquakes on the Cascadia subduction zone, Pacific Northwest (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 131-201 
    Details
    ISSN: 1420-9136
    Keywords: Earthquake ; strong motion ; subduction ; Cascadia ; Washington, Oregon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes ofM s≥7.0 are used to estimate the response spectra that may result from earthquakesM w〈81/4. Large variations in observed ground motion levels are noted for a given site distance and earthquake magnitude. When compared with motions that have been observed in the western United States, large subduction zone earthquakes produce relatively large ground motions at surprisingly large distances. An earthquake similar to the 22 May 1960 Chilean earthquake (M w 9.5) is the largest event that is considered to be plausible for the Cascadia subduction zone. This event has a moment which is two orders of magnitude larger than the largest earthquake for which we have strong motion records. The empirical Green's function technique is used to synthesize strong ground motions for such giant earthquakes. Observed teleseismicP-waveforms from giant earthquakes are also modeled using the empirical Green's function technique in order to constrain model parameters. The teleseismic modeling in the period range of 1.0 to 50 sec strongly suggests that fewer Green's functions should be randomly summed than is required to match the long-period moments of giant earthquakes. It appears that a large portion of the moment associated with giant earthquakes occurs at very long periods that are outside the frequency band of interest for strong ground motions. Nevertheless, the occurrence of a giant earthquake in the Pacific Northwest may produce quite strong shaking over a very large region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874626
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Do trench sediments affect great earthquake occurrence in subduction zones? (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 263-282 
    Details
    ISSN: 1420-9136
    Keywords: Subduction zones ; great earthquakes ; trench sediments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Seismic energy release is dominated by the underthrusting earthquakes in subduction zones, and this energy release is further concentrated in a few subduction zones. While some subduction zones are characterized by the occurrence of great earthquakes, others are relatively aseismic. This variation in maximum earthquake size between subduction zones is one of the most important features of global seismicity. Previous work has shown that the variation in maximum earthquake size is correlated with the variation in two other subduction zone properties: age of the subducting lithosphere and convergence rate. These two properties do not explain all the variance in maximum earthquake size. I propose that a third subduction zone property, “trench sediments”, explains part of the remaining variance in maximum earthquake size. Subduction zones are divided into two groups: (1) those with excess trench sediments, and (2) those with horst and graben structure at the trench. Thirteen of the 19 largest subduction zone events, including the three largest, occur in zones with excess trench sediments. About half the zones with excess trench sediments are characterized by great earthquake occurrence. Most of the other zones with excess trench sediments but without great earthquakes are predicted to have small earthquakes by the age-rate correlation. Two notable exceptions are the Oregon-Washington and Middle America zones. Overall, the presence of excess trench sediments appears to enhance great earthquake occurrence. One speculative physical mechanism that connects trench sediments and earthquake size is that excess trench sediments are associated with the subduction of a coherent sedimentary layer, which at elevated temperature and pressure, forms a homogeneous and strong contact zone between the plates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874629
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The mechanism of small mining tremors from amplitude inversion (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 309-324 
    Details
    ISSN: 1420-9136
    Keywords: Inversion ofP- andS-wave amplitudes ; weak mining tremors ; shear-implosive source model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A method of inverting seismic wave amplitudes from mining tremors is proposed to reveal their mechanism. A simple shear-implosive model of a mechanism is proposed. The shapes of theoretical and observed radiation patterns are compared in the least squares norm and the parameters describing the shear-slip together with the ratio of implosive and shear dislocations are optimized. The efficiency of the method, even in the case of a small number of stations, is demonstrated by applying it to weak mining tremors from two mine regions in Czechoslovakia. The weak mining tremors are found to be of a predominantly shear mechanism with a clear coincidence of nodal planes to local tectonics, which could imply their tectonic nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874512
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Induced gravity anomalies and seismic energy as a basis for prediction of mining tremors (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 535-552 
    Details
    ISSN: 1420-9136
    Keywords: Mining-tremors ; underground gravity measurements ; time changes of gravity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The results of prediction of occurrence of mining tremors and bursts in the course of the exploitation of the remaining part of the hard coal in seam 510 of the mine “Pstrowski”, Upper Silesia, have been presented in the paper. The exploitation has taken place under extremely difficult conditions hazardous for the mining crew. To predict the occurrence of mining tremors, bursts and direction of migration of increased elastic strain in the rock mass, the microgravity method has been applied. The microgravity observations were carried out in the measurement points located at mutual distances equal 20 m in three profiles of the lengths 700 m, 760 m and 260 m respectively. The profiles were located in mining workings in the vicinity of the exploited part of the bed. In the course of exploitation, lasting 25 months, 29 series of measurements including 3600 individual microgravity observations were carried out. Microgravity observations were made with a Worden-Master gravimeter. The observed time changes of gravity microanomalies were essential for prediction. Local negative changes of gravity microanomalies signalled the approaching mining tremor. The tremor would cover an area of the radius 60 m to 100 m. The regional time changes of the gravity microanomalies appearing as linear trends of these anomalies signalled the development of the fields of elastic strain in the whole investigated area and the approaching violent release of elastic strain energy from the rock mass. The values of the amplitudes AMP of the above-mentioned trend were the measure of this hazard. In the course of the investigations each shock was preceded by considerably increased values of AMP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874524
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Rockburst research at Falconbridge's Strathcona Mine, Sudbury, Canada (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 619-645 
    Details
    ISSN: 1420-9136
    Keywords: Rockbursts ; microseismic system ; fault-slip mechanism ; stick-slip ; numerical models ; tomographic imaging ; waveform data ; Sudbury Basin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Microseismic systems at five mines in the Sudbury Basin provide the basic data for Falconbridge Limited's rockburst research. Daily and long-term analysis of this data as well as underground observations have confirmed the fault-slip mechanism at three mines. A detailed analysis of the complete history of Falconbridge Mine is being conducted and Distinct Element numerical models are being used to simulate both the stick-slip behaviour of faults and the dynamic effects of the induced vibrations on rock and backfill. University research includes acoustic tomographic imaging of the rock mass based on seismic wave propagation and collection of full microseismic waveforms to allow application of advanced seismic and statistical analysis techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874529
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Morphologic and geologic effects of the subduction of bathymetric highs (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 41-69 
    Details
    ISSN: 1420-9136
    Keywords: Subduction ; tectonic erosion ; uplift ; aseismic ridges ; subsidence ; deformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Morphologic and geologic observations suggest that subduction of bathymetric highs, such as aseismic ridges, chains of seamounts, and fracture zones, are important in the development of many forearc features and that those features form during relatively brief episodes of intense tectonism. A bathymetric high obliquely entering a subduction zone tends to compress sediments along its leading edge, resulting in arcward compression of the accretionary wedge. A landward deflection of the trench axis and a steepened inner wall result from this deformation. If a significant component of oblique slip occurs along the subduction zone, then along-strike movement of the accretionary wedge may also occur. Stresses resulting from subduction of bathymetric features with sufficient buoyancy or high relief extend farther landward than in the case of smaller, less buoyant features, inducing uplift of the leading edge of the overriding plate. Tectonic erosion of the base of the overriding plate and along-strike transport of are material may also occur. The accelerated tectonism observed along several convergent margins can be attributed to the consumption of bathymetric irregularities on the seafloor rather than temporally abrupt changes in rates and directions of plate motions or other episodic events in the accretionary prism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874624
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Subduction and back-arc activity at the Hikurangi convergent Margin, New Zealand (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 203-231 
    Details
    ISSN: 1420-9136
    Keywords: Subduction ; back-arc basin ; lithospheric coupling ; historical seismicity ; Hikurangi Margin ; New Zealand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The Hikurangi Margin is a region of oblique subduction with northwest-dipping intermediate depth seismicity extending southwest from the Kermadec system to about 42°S. The current episode of subduction is at least 16–20 Ma old. The plate convergence rate varies along the margin from about 60 mm/a at the south end of the Kermadec Trench to about 45 mm/a at 42°S. The age of the Pacific lithosphere adjacent to the Hikurangi Trench is not known. The margin divides at about latitude 39°S into two quite dissimilar parts. The northern part has experienced andesitic volcanism for about 18 Ma, and back-arc extension in the last 4 Ma that has produced a back-arc basin onshore with high heaflow, thin crust and low upper-mantle seismic velocities. The extension appears to have arisen from a seawards migration of the Hikurangi Trench north of 39°S. Here the plate interface is thought to be currently uncoupled, as geodetic data indicate extension of the fore-arc basin, and historic earthquakes have not exceededM s=7. South of 39°S there is no volcanism and a back-arc basin has been produced by downward flexure of the lithosphere due to strong coupling with the subducting plate. Heatflow in the basin is normal. Evidence for strong coupling comes from historic earthquakes of up to aboutM s=8 and high rates of uplift on the southeast coast of the North Island. The reason for this division of the margin is not known but may be related to an inferred increase, from northeast to southwest, in the buoyancy of the Pacific lithosphere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874627
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Fred Leighton Memorial Workshop on mining induced seismicity August 30, 1987 (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 285-293 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Constrains on gravity wave induced diffusion in the middle atmosphere (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 533-546 
    Details
    ISSN: 1420-9136
    Keywords: Gravity waves ; turbulence ; heat transport ; tracer transport ; eddy diffusion ; mesosphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A review of the important constraints on gravity wave induced diffusion of chemical tracers, heat, and momentum is given. Ground-based microwave spectroscopy measurements of H2O and CO and rocket-based mass spectrometer measurements of Ar constrain the eddy diffusion coefficient for constituent transport (K zz ) to be (1–3)×105 cm2s−1 in the upper mesosphere. Atomic oxygen data also limitsK zz to a comparable value at the mesopause. From the energy balance of the upper mesosphere the eddy diffusion coefficient for heat transport (D H ) is, at most 6×105 cm2s−1 at the mesopause and decreasing substantially with decreasing altitude. The available evidence for mean wind deceleration and the corresponding eddy diffusion coefficient for momentum stresses (D M ) suggests that it is at least 1×106 cm2s−1, in the upper mesosphere. Consequently the eddy Prandtl number for macroscopic scale lengths is 〉3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874473
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Spline approximation for TALWANI's method of magnetic anomaly computation (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 699-709 
    Details
    ISSN: 1420-9136
    Keywords: Magnetic anomalies ; Talwani's method ; splines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract When using TALWANI's method for computing magnetic anomalies of three-dimensional bodies unexpected errors may occur. They are caused by the numerical depth integration. It is shown how those errors can be recognized and reduced by employing spline approximations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    On the interpretation of magnetic anomalies for strong remanent magnetizations (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 721-733 
    Details
    ISSN: 1420-9136
    Keywords: Magnetic anomalies ; remanent magnetization ; apparent susceptibility ; interpretation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract In this paper some aspects concerning the interpretation of magnetic anomalies are treated, particularly when the remanent magnetization intensity is strong. In this case, since total and induced magnetization vectors can have very different directions, a correct anomaly interpretation strictly depends on the knowledge of their declinations and inclinations. Thus, a specific procedure is described to determine such parameters from well-known semi-empirical techniques and vectorial relations. Furthermore, the classical definition of apparent susceptibility is shown to be inadequate to this problem and a more general formulation is suggested, which is not only related to the true susceptibility and to the Koenisberger ratio, but also to the declinations and inclinations of the induced and remanent magnetization vectors. The two apparent susceptibilities are then compared for some synthetic magnetic anomalies and significant differences are found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Dip angle determination of fault planes from gravity data (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 735-742 
    Details
    ISSN: 1420-9136
    Keywords: Gravity modeling ; dip angle of faulted structures ; dimensionless amplitudes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This paper illustrates an approach for determining uniquely the dip angle of a faulted structure, approximated by two semi-infinite horizontal slabs, displaced vertically from each other, by making use of the maximum positive and the maximum negative gravity amplitudes. The method is simple and rapid, and it does not necessarily require computing facilities. Two field examples from Aberdeenshire, Scotland and from the Northern Eastern Desert of Egypt are presented in which the angles of dip of two geological contacts are estimated at 45 and 40 degrees, respectively, and verified from surface geology, gravity modeling, and seismic data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Fractal velocity models in refraction seismology (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 61-76 
    Details
    ISSN: 1420-9136
    Keywords: Refraction ; fractal ; raytracing ; scattering ; seismology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The introduction of noise components to a simple crustal velocity model is shown to markedly affect the appearance of synthetic seismograms calculated according to ray theory applied to refraction experiments. Here we simulate noise by a self-similar process with a power spectral density which falls off as inverse wavenumber to a simple power (0–2). The major effect is to destroy the coherency of the arrival branches normally expected from deterministic velocity models; the arrival amplitudes also show large trace-to-trace variations and considerable sensitivity to shot position. Some of these differences can be ascribed to the variety of noise model chosen (i.e., white noise, flicker noise and brown noise). It is argued that there is no clear distinction between coherent noise and geological structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874480
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    An introduction to quiet daily geomagnetic fields (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 315-331 
    Details
    ISSN: 1420-9136
    Keywords: Quiet daily geomagnetic field variations ; Sq ; L ; lunar variations ; ionospheric dynamo currents ; thermotidal currents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract On days that are quiet with respect to solar-terrestrial activity phenomena, the geomagnetic field has variations, tens of gamma in size, with major spectral components at about 24, 12, 8, and 6 hr in period. These quiet daily field variations are primarily due to the dynamo currents flowing in theE region of the earth's ionosphere, are driven by the global thermotidal wind systems, and are dependent upon the local tensor conductivity and main geomagnetic field vector. The highlights of the behavior and interpretation of these quiet field changes, from their discovery in 1634 until the present, are discussed as an introduction to the special journal issue on Quiet Daily Geomagnetic Fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Polar regionSq (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 371-393 
    Details
    ISSN: 1420-9136
    Keywords: S q p , polar ionospheric current ; field-aligned current ; IMF sector effect ; ionosphere-magnetosphere coupling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Geomagnetically quiet day variations in the polar region are reviewed with respect to geomagnetic field variation, ionospheric plasma convection, electric field and current. Persistently existing field-aligned currents are the main source of the polar regionSq. Consequently, the morphology and variability of the polar regionSq largely depend upon both field-aligned currents and ionospheric conductivity. Since field-aligned currents are the major linkage between the ionosphere and the magnetosphere, the latter is controlled by solar wind state, in particular, the interplanetary magnetic field, the polar regionSq exhibits remarkable IMF dependence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876835
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Contribution to geomagneticSq-field and equatorial electrojet from the day/night asymmetry of ionospheric current under dawn-to-dusk electric field of magnetospheric origin (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 437-446 
    Details
    ISSN: 1420-9136
    Keywords: GeomagneticSq-field ; equatorial electrojet ; ionospheric current ; electric field of magnetospheric origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract If the earth and its ionosphere are immersed in a large-scale dawn-to-dusk electric field (of the order of 0.5 mV/m), the resultant dawn-to-dusk ionospheric currents are much stronger on the dayside than on the nightside. These asymmetric currents over the earth produce a magnetic field detectable on the ground, which will contribute to a considerable extent to theSq-field and equatorial electrojet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876838
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Predicting the overall properties of composite materials with small-scale inclusions or cracks (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 551-576 
    Details
    ISSN: 1420-9136
    Keywords: Composite materials ; elastic waves ; cracked materials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract This paper will summarise the present state of knowledge concerning the elastic and dissipative properties of composite materials in the long wavelength or static approximation. In this case the material, although containing numerous inclusions or cracks or other types of microstructure, can be regarded as a continuum. Established results are listed for the elastic parameters following a review of approximate and exact methods of their derivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    The equatorial electrojet (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 485-508 
    Details
    ISSN: 1420-9136
    Keywords: Equatorial electrojet ; counter-electrojet ; electric fields ; electric currents ; magnetic field variations ; wind effects ; magnetosphere-ionosphere interactions ; substorms ; magnetic storm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The typical quiet day variations of the equatorial electrojet (EEJ) current intensity with time of the day, season, sunspot number, and geomagnetic latitude are presented in terms of the corresponding variations of ΔH which is the deviation of the horizontal component (H) of the geomagnetic field from its steady nighttime level. The observed height structure of the current density in the EEJ as measured in rocket flights is presented, along with the theoretically computed structure. Theoretical model results on the polarization electric fields and east-west currents as generated by the local interactions of height-varying winds in the EEJ show large height gradients and reversals for both currents and electric fields; experimental evidence for the reality of such height structures is also shown. The characteristics of the counter-electrojet events are presented and the possible causative mechanisms are discussed critically. Some typical experimental results are presented on the electric field changes in the EEJ which result from its sensitive response to electrodynamic disturbances in the magnetosphere and the auroral-polar latitude ionosphere during geomagnetic substorms and storms; and their implications are discussed. Possibilities for utilizing the EEJ as a very useful medium for important scientific studies on the larger space domain of ionosphere-magnetosphere system, on plasma waves, and on the earth's conductivity are emphasized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876841
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Subsolar elevation of the equatorial electrojet (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 509-525 
    Details
    ISSN: 1420-9136
    Keywords: Equatorial electrojet ; ionospheric electrical current
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The subsolar elevation of the equatorial electrojet has been produced from satellite solstitial data available from 09 to 15 hr LT using a new approach with the general style of the overhead equivalent current system. It shows the bunching of the current around the dip equator; the return currents of the equatorial electrojet close to the flanks of the dip equator; the fast growth of the electrojet to its diurnal peak followed by a slow decay; and the contraction of its latitudinal extent around the meridian of its highest intensity. Comparison with the results of other workers using ground data suggests that the elevation from satellite data agrees better with that from ground data when the worldwideSq is removed from the ground data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876842
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    The perturbation method in elastic wave scattering (1989)
    Springer
    Pure and applied geophysics 131 (1989), S. 605-637 
    Details
    ISSN: 1420-9136
    Keywords: Scattering ; elastic wave ; perturbation method ; heterogeneity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Methods of theoretical study in seismic wave scattering are reviewed with the emphasis on the perturbation method. Detailed analysis for weak scattering using Born approximation is given. For elastic random media, the mean square amplitudes of scattered waves are derived using a new approach by working directly in the spectrum domain. The conditions for the scalar wave approximation are obtained. The problem of sensitivity of fore- and backscattering to heterogeneities with different scales and properties (velocity or impedance) is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876266
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    The effect of horizontal resolution on gravity waves simulated by the GFDL “SKYHI” general circulation model (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 421-443 
    Details
    ISSN: 1420-9136
    Keywords: Gravity waves ; SKYHI model ; horizontal resolution ; space-time spectra ; Eliassen-Palm flux
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract To examine the effects of horizontal resolution on internal gravity waves simulated by the 40-level GFDL “SKYHI” general circulation model, a comparison is made between the 3° and 1° resolution models during late December. The stratospheric and mesospheric zonal flows in the winter and summer extratropical regions of the 1° model are much weaker and more realistic than the corresponding zonal flows of the 3° model. The weaker flows are consistent with the stronger Eliassen-Palm flux divergence (EPFD). The increase in the magnitude of the EPFD in the winter and summer extratropical mesospheres is due mostly to the increase in the gravity wave vertical momentum flux convergence (VMFC). In the summer extratropical mesosphere, the increase in the resolvable horizontal wavenumbers accounts for most of the increase in the gravity wave VMFC. In the winter extratropical mesosphere, the increase of VMFC associated with large-scale eastward moving components also accounts for part of the increase in the gravity wave VMFC. The gravity waves in the summer and winter mesosphere of the 1° model are associated with a broader frequency-spectral distribution, resulting in a more sporadic time-distribution of their VMFC. This broadening is due not only to the increase in resolvable horizontal wavenumbers but also occurs in the large-scale components owing to wave-wave interactions. It was found that the phase velocity and frequency of resolvable small-scale gravity waves are severely underestimated by finite difference approximations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874467
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Falling sphere observations of anisotropic gravity wave motions in the upper stratosphere over Australia (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 509-532 
    Details
    ISSN: 1420-9136
    Keywords: Middle atmosphere ; intertial scale gravity wave ; Stokes parameters ; momentum fluxes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A study of inertial scale gravity wave motions in the region of the atmosphere between 30 and 60 km has been undertaken, using wind and temperature data derived from rocket-borne falling sphere density experiments performed over Woomera, Australia between 1962 nad 1976. The gross features of the wave field compare favorably with those found in similar northern hemispheric studies. Wave propagation is found to be both vertically and horizontally anisotropic. A rotary spectral analysis indicates predominately upgoing wave energy, suggesting that the majority of sources of these waves lie below 30 km. A detailed statistical investigation of the waves, made using the Stokes parameters technique, reveals that phase progression is also highly directional in the horizontal, with a significant zonal component in summer, but with a strong meridional component in winter. Propagation towards the southeast is inferred in summer, with the waves possibly emanating from tropospheric sources in equatorial regions to the north of Australia. The technique also shows that, on average, the waves appear to have mean ellipse eccentricities (=f/ω) around 0.4–0.45. Indirect estimates of a number of important wave parameters are made. In particular,v′ andw′ flux estimates are made over several height intervals. The vertical gradient of density weighted flux implies wave-induced mean flow accelerations of the order 0.1–1 ms−1day−1. This suggests that dissipating gravity waves are a significant source of the momentum residuals that are encountered in studies of satellite data from this region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874472
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Biochemical-genetic differentiation among nine species of polistine wasps from Japan (1989)
    Springer
    Insectes sociaux 36 (1989), S. 183-196 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die genetischen Beziehungen zwischen neun japanischen Feldwespenarten wurden mittels der Stärkegel-Enzymelektrophorese untersucht, und zwar die ArtenRopalidia fasciata undParapolybia indica sowie siebenPolistes-Arten: zwei Arten des SubgenusPolistes (P. chinensis, P. riparius), zwei Arten des SubgenusMegapolistes (M. jadwigae, M. rothneyi), drei Arten des SubgenusPolistella (P. mandarinus, P. japonicus, P. snelleni). Die Dendrogramme zeigen, daß sich die GattungenRopalidia undParapolybia deutlich von den siebenPolistes-Arten unterscheiden. Das SubgenusPolistes unterscheidet sich auffällig von den beiden anderen Subgenera der GattungPolistes. Das SubgenusPolistella ist keine monophyletische Gruppe, sondern die beiden ArtenP. mandarinus undP. japonicus besitzen eine engere genetische Verwandtschaft zu Arten des SubgenusMegapolistes als zu der ArtP. snelleni.
    Notes: Summary Genetic relationships among nine species of polistine wasps of Japan, that is,Ropalidia fasciata, Parapolybia indica, two species of the subgenusPolistes (chinensis andriparius), two species of the subgenusMegapolistes (jadwigae androthneyi) and three species of the subgenusPolistella (mandarinus, japonicus andsnelleni) of the genusPolistes, were examined by starch-gel electrophoresis of the enzymes. Dendrograms drawn from the result suggested that the generaRopalidia andParapolybia occupied distinctly different positions from seven species ofPolistes, that the subgenusPolistes diverged conspicuously from the other two subgenera in the genusPolistes, and that the subgenusPolistella was not a monophyletic group but the speciesmandarinus andjaponicus belonging to this subgenus had genetic relationships closer to the mmembers of the subgenusMegapolistes than to the speciessnelleni of the subgenusPolistella.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02226303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    The composition of larval food in stingless bees: Evaluating nutritional balance by Chemosystematic methods (1989)
    Springer
    Insectes sociaux 36 (1989), S. 1-14 
    Details
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die ausgewogene Zusammensetzung des Larvenfutters wird allgemein als ein wichtiger Faktor in der Kastenbildung der Honigbiene angesehen. Ob dies für Stachellose Bienen in ähnlicher Weise gilt, war eine offene Frage. Wir analysierten die wasserlöslichen Hauptkomponenten im Larvenfutter von 7 Meliponinen-Arten. Die Ergebnisse wurden herangezogen, um die Hypothese zu überprüfen, daß eine ausgewogene Zusammensetzung des Larvenfutters der Selektion unterliegt. Dazu wurden chemosystematische Bäume berechnet und mit einem bereits publizierten, strukturell-morphologisch begründeten Stammbaum verglichen. Ein beträchtlicher Grad an Kongruenz zwischen den chemosystematischen Bäumen für die allgemeine Zusammensetzung des Larvenfutters und dem Stammbaum erlaubte es, die Zusammensetzung des Larvenfutters hoch-eusozialer Bienen in Bezug auf die funktionalen Aspekte der Larvenernährung zu diskutieren.
    Notes: Summary Nutritional balance of larval food supposedly plays an important role in honey bee caste formation. Whether this is similar in stingless bees was an open question. We analysed the major water-soluble constituents in the larval food of 7 species of meliponids. The data were used to evaluate the hypothesis that a balanced composition of larval food is shaped by selection. Chemosystematic trees were calculated and compared to a published phylogenetic tree based on morphological characters. A considerable degree of congruence between the chemosystematic trees for the general composition of larval food and the phylogenetic tree allowed us to discuss the composition of larval food in highly eusocial bees in relation to functional aspects of larval nutrition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02225876
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Induced seismicity in mines in Canada—An overview (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 423-453 
    Details
    ISSN: 1420-9136
    Keywords: Elastic effects ; inelastic after-effects ; monitor seismicity ; mitigate hazards
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Monitoring of mine-induced seismicity in Canada has improved with the expansion of regional seismograph networks into areas of active mining. However, the severity, and in some cases the frequency, of mine-induced tremors has increased as mining extends to greater depths and at accelerated rates of extraction. Because of the complex design and large areal extent of many mines (potash, coal and metalliferous), the most feasible and practical way to monitor these tremors at the present time is to deploy a network of seismometers in and on the surface above mines experiencing microearthquake activity. A few of these mines already have a network of seismometers deployed around them and plans are under way to deploy seismograph networks around other mines that have experienced some rather severe tremors in recent times. Six possible mechanisms for mine-induced tremors are described and the associatedP- andS-wave radiation patterns presented. A comparison of actual seismic radiation patterns with theoretical predictions is a quick way to diagnose the potential source mechanisms. In addition, recognizing the pattern of microearthquake activity preceding larger tremors can be used to mitigate the potential effects of severe tremors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Seismological models for mining-induced seismic events (1989)
    Springer
    Pure and applied geophysics 129 (1989), S. 513-521 
    Details
    ISSN: 1420-9136
    Keywords: Mine-induced seismicity ; source models ; barrier/asperity models ; seismic moment ; rockbursts ; damaged area
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract One possibility to estimate and to interpret the source parameters of low-stress drop seismic events to use the barrier or the asperity model. These models serve as the description of seismic events in a in which a horizontal room and pillar mining method is used in great depth. An additional macroseismic parameter, the destroyed or damaged area in the mine, allows the estimation of the real static stress drop of mining-induced seismic events. This stress drop, derived from a simplified barrier-or asperity-model, appears to be a constant and a characteristic parameter for a given source region. On this base, a relation between the underground destruction or damages and the seismologically estimated parameters is derived and is used for the classification of the mining-induced seismic events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874522
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Effect of occurrence rate of acoustic emissions on their statistical behavior (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 5-29 
    Details
    ISSN: 1420-9136
    Keywords: Acoustic emission (AE) ; masking effect ; m-value ; AE rate ; time interval distribution of AEs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The parameterm in Ishimoto-Iida's relation was investigated for acoustic emissions (AEs) occurring in rock samples under uniaxial compression. In the experiment, we found: 1) The large AEs are counted without serious error but the number of small AEs is systematically underestimated at high AE rates, 2) the frequency distribution of maximum AE amplitudes becomes nonlinear in logarithmic scale with increasing AE rate, and 3) there exists a strong negative correlation betweenm-value and AE rate. The miscount of small AEs was interpreted as due to overlap of the large and small AEs. We call the miscount “masking effect”. A statistical analysis based on the masking effect showed that them-value decreases more effectively as the AE rate increases, and thus the masking effect is a possible origin both for the nonlinear frequency distribution of maximum AE amplitudes and for the negative correlation ofm-value with AE rate. We emphasize that one should be careful of the masking effect to examine correctly the change, ofm-value. In order to eliminate the masking effect, AEs should be measured by a measurement system with low sensitivity. Even if the masking effect is eliminated, them-value decreases before the main fracture of a rock sample. Them-value is a key parameter to predict the main fracture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877734
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Internal gravity wave selection in the upper troposphere and lower stratosphere observed by the MU radar: Preliminary results (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 481-495 
    Details
    ISSN: 1420-9136
    Keywords: MST radar observation ; internal gravity waves ; monochromatic analysis ; wave-mean flow interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Marked wavelike variations of the lower stratospheric wind observed on 7–10 May, 1985 by an MST radar in Japan (by the MU radar) are analyzed assuming that they are induced by monochromatic internal inertio-gravity waves. These variations are mainly composed of two modes (periods: 22 and 24 hours), both of which have zonal phase velocities (C X ) slower than the mean westerly wind (ū). A statistical analysis of the zonal phase velocity shows thatC X ≲ū above andC X ∼ū below the tropopause jet stream, which is considered to be a vivid proof of wave selection due to the tropospheric mean flow and upward wave emission from the tropopause jet. A comparison between the MU radar results and routine meteorological observations leads to the conclusion that the marked waves appear when the jet stream takes a maximum wind speed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874470
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Temperature and heat flux spectra in the turbulent buoyancy subrange (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 547-569 
    Details
    ISSN: 1420-9136
    Keywords: Turbulence ; atmospheric turbulence ; clear air turbulence ; middle atmosphere ; heat flux
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The physical nature of motions with scales intermediate between approximately isotropic turbulence and quasi-linear internal gravity waves is not understood at the present time. Such motions play an important role in the energetics of small scales processes, both in the ocean and in the atmosphere, and in vertical transport of heat and constituents. This scale range is currently interpreted either as a saturated gravity waves field or as a buoyancy range of turbulence. We first discuss some distinctive predictions of the classical (Lumley, Phillips) buoyancy range theory, recently improved (Weinstock, Dalaudier and Sidi) to describe potential energy associated with temperature fluctuations. This theory predicts the existence of a spectral gap in the temperature spectra and of an upward mass flux (downward buoyancy and heat fluxes), strongly increasing towards large scales. These predictions are contrasted with an alternate theory, assuming “energetically insignificant” buoyancy flux, proposed by Holloway. Then we present experimental evidences of such characteristic features obtained in the lower stratosphere with an instrumented balloon. Spectra of temperature, vertical velocity, and cospectra of both, obtained in homogeneous, weakly turbulent regions, are compared with theoretical predictions. These results are strongly consistent with the improved classical buoyancy range theory and support the existence of a significant downward heat flux in the buoyancy range. The theoretical implications of the understanding of this scale range are discussed. Many experimental evidences consistently show the need for an anisotropic theory of the buoyancy range of turbulence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Multiasperity fault model and the nature of short-period subsources (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 635-660 
    Details
    ISSN: 1420-9136
    Keywords: Earthquake source spectrum ; asperity ; strong ground motion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We suggest to consider the breaking of an asperity,i.e., a small contact patch between fault walls, as a typical subsource producing an elementary short-period radiation pulse from a source of a large earthquake. Based on the results ofDas andKostrov we propose formulas to describe amplitudes and spectra of acceleration for a multiasperity fault/source model. The stress drop over an asperity is determined in several ways; the estimates agree to give the average value of several hundred bar. Theoretical acceleration spectral shapes for the case of similar asperities agree with the observed ones, they reproduce such features as lower-frequencyf 1 slope, peak, and high-frequency cutoff. The statistical stress-drop distribution over the population of asperities, and also the related distribution of peak accelerations are discussed. There distributions are found to be the power-law ones with exponent near to 2. This means that acceleration peaks are formed normally by breaking of individual asperities. We consider small earthquakes as produced by breaking of single asperities, this idea explains the observed correlation between the upper cutoff frequency of acceleration spectrum and the typical characteristic frequency of small earthquakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00881602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Surface ozone variation associated with rainfall (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 47-55 
    Details
    ISSN: 1420-9136
    Keywords: Surface ozone ; rainfall ; vertical mixing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Using an electrochemical surface ozone recorder, continuous monitoring of surface ozone is being carried out at Trivandrum (8°29′N, 76°57′E). A study of those surface ozone data together with rainfall and temperature reveals certain variations in ozone associated with rainfall, apart from other established variations reported so far. While daytime rainfall brings a decrease in surface ozone, nighttime rainfall produces an increase. The change in the surface ozone persists for a longer duration than the rainfall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877736
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Book review (1989)
    Springer
    Pure and applied geophysics 130 (1989), S. 127-148 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877740
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...