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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Human evolution 6 (1991), S. 193-200 
    ISSN: 1824-310X
    Keywords: Laetoli footprints ; Australopithecus afarensis ; toes ; bipedalism ; hominid evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The probable misfit between feet, particularly toes II–V, of 3.0-million-year-oldAustralopithecus afarensis from Hadar, Ethiopia, and the 3.5-million-year-old hominid footprints at Site G, Laetoli, Tanzania, casts doubt thatA. Afarensis made the Laetoli trails. We suggest that another species ofAustralopithecus or an anonymous genus of the Hominidae, with remarkably humanoid feet, walked at Laetoli. It would be imprudent to declare thatHomo was present at Laetoli 3.5 million years ago (my) because there is no evidence of brain expansion, advanced tool manufacture, or other non-locomotor hallmarks of the human condition at Site G.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Behavioral ecology and sociobiology 8 (1981), S. 175-182 
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Social behavior of 15 colonies of Yellow-bellied Marmots was studied at sites differing in both elevation (plant growing season length) and patch structure (density and spacing of suitable colony sites in large blocks of habitat) from 1976 through 1978. Colonies were typically composed of family groups. In low elevation colonies, offspring dispersed at the end of the juvenile year. In all high elevation areas, offspring dispersed as yearlings, and parent-offspring and sibling interactions during the juvenile year were highly amicable. In high elevation areas in continuous habitat, dispersal by yearlings occurred with no agonistic interactions. In high elevation areas with patchy habitat, however, brief but intense periods of extremely agonistic sibling and parent-offspring interactions occurred immediately prior to dispersal of yearlings. Social behavior and dispersal are uncorrelated with elevation, plant growing season length, or available foraging time. Social interaction among relatives in marmot colonies is amicable when other suitable colony sites are located nearby; in these areas, dispersal occurs without any antagonism. Agonistic behavior occurs only in areas with a patchy distribution of suitable colony sites. At these sites, dispersal occurs only after periods of extreme antagonism. Further, those offspring who do not disperse from the colony site are the ones who dominate and initiate agonistic interactions with their siblings. The large-scale structure of the habitat influences the propensity of the individual to disperse. When the animal is reluctant to disperse because of a combination of high transit difficulty and low desirability of a new site, angonistic social interactions with relatives force dispersal.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 257-258 (Feb. 2004), p. 213-218 
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 64 (1996), S. 49-56 
    ISSN: 0340-3793
    Keywords: PACS: 42.40 ; 42.65 ; 42.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract.  A generalized systematic description of the Two-Wave Mixing (TWM) process in sillenite crystals allowing for arbitrary orientation of the grating vector is presented. An analytical expression for the TWM gain is obtained for the special case of plane waves in a thin crystal (∣g∣d≪1) with large optical activity (∣g∣/ϱ≪1, g is the coupling constant, ϱ the rotatory power, d the crystal thickness). Using a two-dimensional formulation the scope of the nonlinear equations describing TWM can be extended to finite beams in arbitrary geometries and to any crystal parameters. Two promising applications of this formulation are proposed. The polarization dependence of the TWM gain is used for the flattening of Gaussian beam profiles without expanding them. The dependence of the TWM gain on the interaction length is used for the determination of the crystal orientation. Experiments carried out on Bi12GeO20 crystals of a non-standard cut are in good agreement with the results of modelling.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of clinical immunology 3 (1983), S. 90-99 
    ISSN: 1573-2592
    Keywords: C8 deficiency ; recurrent meningococcal infection ; HLA linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An adult male with recurrent meningococcal infections is reported whose serum lacked functional C8 activity but possessed antigenic C8. The addition of 1500 U of purified C8/ml of serum restored hemolytic activity to normal. Four to five times more C8 was required to restore bactericidal activity than to restore hemolytic activity. Bactericidal activity could also be restored by mixing the patient's serum with a second C8-deficient serum that lacked detectable antigenic or functional C8. The patient's serum contained bactericidal antibody for groups A, B, C, and Y meningococci and specific antibody to group Y capsular polysaccharide. There was two to three times more bactericidal antibody activity in the serum than in a pool of normal sera for the infecting strain. Family studies disclosed a sibling who was HLA identical to the patient but whose serum contained normal amounts of total hemolytic and C8 functional activity.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric surgery international 5 (1990), S. 451-453 
    ISSN: 1437-9813
    Keywords: Percutaneous nephrolithotomy ; Lithotripsy ; Calculi ; Extracorporeal shock wave lithotripsy ; Endourology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Childhood urolithiasis is uncommon, comprising 2% – 3% of urinary calculi. This paper presents our initial experience in the endourological (EU) treatment of 23 children with urinary calculi presenting to the Royal Childrens' Hospital. Twenty-seven renal, ureteric, and vesical calculi were treated. Three strictures were divided endoscopically synchronously with calculus removal. Twenty-three calculi were renal (6 staghorn, 3 cystine), 2 ureteric, and 2 vesical. In 12 patients (mean age 17.5 years, range 5–24), the underlying cause was a neuropathic bladder secondary to spina bifida. Ten of these had ileal conduits, 1 was successfully undiverted, and 1 previously undiagnosed (all infected). The second group of 11 patients (mean age 10.1 years, range 5–16) had normal renal anatomy. Seventeen (63%) were treated by percutaneous nephrolithotomy (PCNL) or endoscopic lithotripsy via their conduit (n = 1) or bladder (n = 2). Three (11%) underwent combined extracorporeal shock wave lithotripsy (ESWL) and PCNL and 7 (26%) were treated by ESWL alone. Twenty-one (77%) were cleared of stone by their primary procedure. Four patients with residual calculi following ESWL have a decreased volume of stone and 2 patients with staghorn calculi treated by PCNL have peripheral fragments only (1 bilateral). There was no mortality or significant morbidity except sepsis in 4 patients, which was treated medically. This series demonstrates that EU and ESWL techniques are safe and effective in children and patients with spina bifida, who often have marked scoliosis, urinary diversion, and difficulties in access. In our experience, paediatric calculi were associated with infection, metabolic disorders, urinary diversion, and patient deformities, and so the majority were more appropriately treated by endourological techniques. ESWL was effective for small stones and in combination with EU for complex stones. By using EU and ESWL alone or in combination, we have avoided open surgery in all patients with urinary calculi treated so far.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 22 (1972), S. 150-177 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A grazing incidence X-ray telescope on board the OSO-IV spacecraft obtained images of the Sun in the 2.5 to 12 Å waveband nearly continuously from 27 October 1967 to 12 May 1968. The instrument had sufficient spatial resolution (one and four arc minutes) and temporal resolution (5 to 20 min) to estimate the spatial characteristics of X-ray emitting regions and to monitor the temporal behavior of individual active regions. Variations in the absence of flares of as much as a factor of 10 in the X-ray output of individual regions were observed, with typical durations ranging from several hours to several days. The X-ray time variations are related to observations at optical and radio wavelengths. The results are interpreted under the assumption that the X-ray time variations are caused by temperature changes in the coronal portions of active regions. The contribution of radiative losses to the energy budget of the coronal active region is estimated.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 70 (1981), S. 335-350 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A flare event occurred which involved the disappearance of a filament near central meridian on 29 August 1973. The event was well observed in X-rays with the AS & E telescope on Skylab and in Hα at BBSO. It was a four-ribbon flare involving both new and old magnetic inversion lines which were roughly parallel. The Hα, X-ray, and magnetic field data are used to deduce the magnetic polarities of the Hα brightenings at the footpoints of the brightest X-ray loops. These magnetic structures and the preflare history of the region are then used to argue that the event involved a reconnection of magnetic field lines rather than a brightening in place of pre-existing loops. The simultaneity of the Hα brightening onsets in the four ribbons and the apparent lack of an eruption of the filament are consistent with this interpretation. These observations are compared to other studies of filament disappearances. The preflare structures and the alignment of the early X-ray flare loops with the Hα filament are consistent with the schematic picture of a filament presented first by Canfield et al. (1974).
    Type of Medium: Electronic Resource
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