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  • 1
    Electronic Resource
    Electronic Resource
    Cold stratification and growth of radicles of loblolly pine (Pinus taeda) embryos (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 59 (1983), S. 0 
    Details
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The mechanism of germination enhancement by cold stratification was examined in seeds of loblolly pine (Pinus taeda L.), Removal of the seed coat permitted elongation of radicles from unstratified embryos, but both rates of germination and radicle elongation were increased by stratification. Radicles of both stratified and unstratified embryos excised from the megagamethophyte elongated only when in contact with solid incubation media supplemented with sucrose. Stratification of embryos either in the presence or absence of the megagametophyte resulted in similar enhancement of radicle elongation. Elongation rates of radicles were increased after stratification independent of sucrose concentration, and changes in sucrose content in the megagamethophyte during stratification or incubations subsequent to stratification were insufficient to regulate radicle growth. Our results support the hypothesis that the embryos of pine seeds perceive the low temperature stimulus directly and this stimulus results in a growth potential increase in the embryonic axes. We propose that this growth potential increase enables the embryos to overcome the mechanical restraint of the seeds coats and to germinate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1399-3054.1983.tb06287.x
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of nutritional copper deficiency on adjuvant arthritis and immunocompetence in the rat (1984)
    Springer
    Inflammation research 14 (1984), S. 274-282 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Both severe and marginal copper deficiency were produced in male Sprague Dawley rats prior to induction of adjuvant arthritis. Degree of copper deficiency was confirmed by analysis of plasma, liver, and brain samples prior to adjuvant injection. Incidence of adjuvant arthritis was the same in both copper deficient and control animals although the severity was slightly but not statistically less in the former. However, recovery from foot edema was impaired in copper-deficient animals, while marginally copper-deficient animals recovered at the same rate as did controls. Plasma copper concentration increase in response to the injection of adjuvant and the increase was directly related to dietary copper content. Plasma zinc concentration was decreased in arthritic animals and the decrease was inversely correlated to paw edema. Liver copper, zinc, and iron concentrations in arthritic animals remained unchanged or increased slightly in comparison to the corresponding non-injected controls. Copper-deficient rats were immunosuppressed as demonstrated by impaired responsiveness to the T-cell dependent contact sesitizing agent oxazolone and diminshed capacity to respond to the T-cell independent antigen Type III pneumococcal polysaccharide. Although a statistical difference in paw volumes was not found for group of animals fed diets differing in copper content, it is postulated that copper deficiency may alter the severity and kinetics of adjuvant arthritis by impairing aspects of the immune response and the tissue repair processes subsequent to injury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01966653
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Some genetical and biochemical attempts to elucidate the energetics of sugar uptake and explain the Kluyver effect in the yeast Kluyveromyces lactis (1983)
    Springer
    Current genetics 7 (1983), S. 323-325 
    Details
    ISSN: 1432-0983
    Keywords: Disaccharide utilization ; Kluyveromyces lactis ; Anaerobic ; Aerobic ; Kluyver effect ; Respiratory chain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A mutant of Kluyveromyces lactis is described which did not grow with substrates giving the Kluyver effect. In addition it could not grow with non-fermentable carbon sources, although it was not respiratory deficient. Abolition of respiration by cyanide also caused inability to grow with substrates showing the Kluyver effect in the wild-type strain. When the yeasts were using substrates showing the Kluyver effect, shifting to anaerobic conditions gave an immediate decrease in the intracellular concentration of d-glucose 6-phosphate. The results obtained were consistent with the need of a common respiratory and/or anabolic pathway for the utilization of these substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376078
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  • 4
    Electronic Resource
    Electronic Resource
    Starch utilization by yeasts: mutants resistant of carbon catabolite repression (1984)
    Springer
    Current genetics 8 (1984), S. 525-530 
    Details
    ISSN: 1432-0983
    Keywords: Starch utilization ; Yeasts ; Repression-Resistance ; Mutants ; Schwanniomyces occidentals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Twenty-seven yeasts were screened for starch breakdown; the three with the highest rate were strains of Filobasidium capsuligenum, Lipomyces starkeyi and Schwanniomyces occidentalis. Of these, only the last gave mutants with diminished carbon catabolite repression and, hence, enhanced amylase activity. Unlike those yeasts previously reported to break down starch rapidly, these mutants had the commercially advantageous characteristic of growing only slowly on the products of starch break-down and gave rise to readily-inducible auxotrophs. Like hex1 mutants of Saccharomyces cerevisiae, these mutants of Schwanniomyces occidentalis (i) had diminished hexokinase activity, (ii) retained high levels of glucokinase and (iii) resisted carbon catabolite repression of invertase and α-D-glucokinase. In one mutant, isomaltase was induced in the late exponential phase of growth on starch, and this isomaltase was also resistant to repression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00410439
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  • 5
    Electronic Resource
    Electronic Resource
    Plasmodesmata and pit development in secondary xylem elements (1982)
    Springer
    Planta 155 (1982), S. 251-260 
    Details
    ISSN: 1432-2048
    Keywords: Pit development ; Plasmodesma ; Xylem, secondary, differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Developing pit membranes of secondary xylem elements in Drimys winteri, Fagus sylvatica, Quercus robur, Sorbus aucuparia, Tilia vulgaris and Trochodendron aralioides have been examined by transmission electron microscopy. Absence of plasmodesmata from the membranes of vessel elements and tracheids indicates that their pits develop independently of these structures. On the other hand, plasmodesmata are abundant in pit membranes between fibres, parenchyma cells, and combinations of these cell types in Fagus, Quercus and Tilia. In each case the plasmodesmata pass right through the developing pit membrane. In the case of Sorbus fibres, however, plasmodesmata were absent from the majority of pit membrane profiles seen in sections. Occasionally they were observed in large numbers associated with a swollen region on one side of the pit membrane between fibres and between fibres and parenchyma, radiating from a small area of the middle lamella. In the case of fibre to parenchyma pitting, this swelling was always found on the fibre side of the membrane, while on the other side a small number of plasmodesmata were present completing communication with the parenchyma cytoplasm. These observations are discussed with regard to the role of plasmodesmata in pit formation, and in the differentiation of the various cell types in secondary xylem. The significance their distribution may have for our understanding of xylem evolution is also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00392724
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    The measurement of cognitive impulsiveness: Psychometric properties of two automated adult versions of the Matching Familiar Figures Test (1981)
    Springer
    Journal of psychopathology and behavioral assessment 3 (1981), S. 281-295 
    Details
    ISSN: 1573-3505
    Keywords: cognitive impulsiveness ; Matching Familiar Figures Test ; adults ; age differences ; automated testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Psychology
    Notes: Abstract An automated version of the Matching Familiar Figures Test (MFFT) was administered to undergraduates, along with a parallel from. The latency-errors correlation (−0.61) was higher than that reported for most studies in children and weakly supports the view that the correlation increases with age. Repeated exposure resulted in improved performance, which was faster, more accurate, and more efficient, but there was no effect on impulsiveness. Reliability and internal consistency of both forms were acceptably high and the forms were comparable. Use of the univariate measures (impulsiveness-reflectiveness and efficiency-inefficiency) is superior to other scoring methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01350832
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