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  • 1970-1974  (5)
  • 1960-1964
  • Microvilli  (2)
  • Rats  (2)
  • Acquisition  (1)
  • Albumin  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Slow evolution of transferrin and albumin in birds according to micro-complement fixation analysis (1974)
    Springer
    Journal of molecular evolution 3 (1974), S. 243-262 
    Details
    ISSN: 1432-1432
    Keywords: Transferrin ; Albumin ; Micro-Complement Fixation ; Protein Evolution ; Evolutionary Rates ; Birds ; Crocodilians
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Rabbit antisera were prepared to purified ovotransferrin from chicken (order Galliformes) and red-winged blackbird (order Passeriformes) and to purified serum albumin from chicken and rhea (order Rheiformes). Quantitative microcomplement fixation was used to compare these proteins immunologically with those of representatives of all 27 orders of birds. The average interordinal immunological distances were 123 units for transferrin and 53 units for albumin. Extensive intraordinal comparisons of transferrin among 51 species within the order Galliformes and 33 species within the order Passeriformes were also carried out. Values ranging from 0–75 immunological distance units were found within each order. Rabbit antisera to purified alligator albumin were also prepared and shown to react with representatives of all 27 orders of birds, the average immunological distance being 166 units. When the data presented here are considered in relation to the fossil record of birds, it appears that transferrin and albumin have evolved more slowly in birds than in other vertebrates. If prevailing interpretations of the fossil record are correct, transferrin has evolved 2–4 times as fast in mammals and snakes as in birds, while serum albumin has evolved about 3 times as fast in mammals, iguanids, crocodilians, and frogs as in birds. Published immunological and sequence comparisons of lysozyme and cytochromec are also consistent with a slower rate of evolution in birds than in other vertebrates. The implications of a general slowdown in the evolution of bird proteins are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01796041
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Ethanol as a reinforcer: Effects of fixed-ratio size and food deprivation (1973)
    Springer
    Psychopharmacology 28 (1973), S. 171-183 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol Drinking ; Ethanol Reinforcement ; Fixed-Ratio Size ; Food Deprivation ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats having prior experience with ethanol drinking were subjected to geometrically increasing fixed-ratio (FR) schedules of ethanol reinforcement (8% W/V). The rats were tested first food deprived and then food satiated. Each third day ethanol was the reinforcer (0.25 ml/reinforcement), while on other days water, which served as the vehicle control, was available. Food satiating the rats decreased responding for ethanol whereas responding for water was not changed. Under both food conditions ethanol maintained responding at FR's up to 256 with response totals exceeding water control values. As the FR size increased to intermediate values, the number of ethanol responses increased. Further FR increases resulted in decreases in ethanol responding. The pattern of FR responding was similar to that maintained by other reinforcers. Maximum ethanol responding occurred at the beginning of the 6-h sessions, followed by a pause and then intermittent bursts of responding. Water responding was not characterized by a specific pattern. It was inferred that the odor of ethanol functioned as a discriminative stimulus, and it was concluded that ethanol served as a reinforcer for the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00421402
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Rapid establishment of ethanol as a reinforcer for rats (1974)
    Springer
    Psychopharmacology 37 (1974), S. 311-321 
    Details
    ISSN: 1432-2072
    Keywords: Rats ; Ethanol ; Ethanol Reinforcement ; Acquisition ; Schedule-Induced-Polydipsia ; Ethanol Concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Daily 6-h sessions were run during which each lever press by rats produced brief access to water, or to 8
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428917
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Patterns of morphogenesis mediated by dynamic microvilli: Chaetogenesis in Nereis vexillosa (1974)
    Springer
    Cell & tissue research 151 (1974), S. 141-157 
    Details
    ISSN: 1432-0878
    Keywords: Setae ; Polychaeta ; Microvilli ; Morphogenesis ; Chaetogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of morphogenesis of the chitinous compound (jointed) setae of the larvae of polychaete Nereis vexillosa Grube was deduced from electron-microscopic analyses of many stages of secretion. Each seta is secreted over a period of three days within an epidermal follicle consisting of several lateral cells and a basal cell (chaetoblast). The configuration of the apical surface of the chaetoblast changes continuously during secretion. Secreted setal material is polymerized into longitudinally oriented setal filaments, probably by enzymes located on the surfaces of microvilli of the chaetoblast. As a result of this process the setae lengthen by basal appositional growth. We infer that the precise size and shape of each complex seta (a characteristic of the species and the age of the worm) is controlled by sequential modulations of the number, size, shape, arrangement and orientation of the microvilli of the chaetoblast. Each seta embodies a cryptic record of the activities of the chaetoblast on which it formed. The genetic and epigenetic mechanisms involved in chaetogenesis are problematic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222219
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Cephalopod integument: The ultrastructure of Kölliker's organs and their relationship to setae (1974)
    Springer
    Cell & tissue research 151 (1974), S. 293-308 
    Details
    ISSN: 1432-0878
    Keywords: Integument ; Octopus ; Setae ; Secretion ; Microvilli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Kölliker's tufts are transient epidermal bristles found on the external surfaces of late embryonic and juvenile octopods. The structure and growth of Kölliker's tuft is remarkably similar to that of polychaete setae. Each tuft is a fasicle of approximately 1500 distally tapered cannular rodlets located in an epidermal follicle composed of several lateral follicular cells and a single basal chaetoblast. The base of the follicle is associated with obliquely striated dermal muscle fibers. Together these elements comprise Kölliker's organ. The rodlets, composed of longitudinally oriented filaments, are separated basally from one another by a layered meshwork of interstitial filaments. Microvilli on the apical concave surface of the scyphate chaetoblast insert into the base of each rodlet. We infer that the tuft elongates by basal appositional growth and that glycoprotein secreted by the follicle cells is organized into filaments by the apical plasmalemma of the chaetoblast. Each microvillus serves as a template for the formation of a rodlet, therefore the number, size, shape, distribution and dynamic activity of the microvilli determine the morphology of the tuft.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224540
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    Paper (German National Licenses)
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