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
Filter
  • IGF-I  (1)
  • Nitrogen fixation mutants  (1)
  • Oligonychus gossypii  (1)
  • 1995-1999  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Comparison of biological and demographic parameters forMononychellus progresivus andOligonychus gossypii on cassava: influence of temperature (1995)
    Springer
    Entomologia experimentalis et applicata 75 (1995), S. 119-125 
    Details
    ISSN: 1570-7458
    Keywords: Acaru ; Tetranychidae ; Mononychellus progresivus ; Oligonychus gossypii ; biological ; demographic parameters ; cassava
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of five constant temperatures (16, 22, 26, 31 and 36°C) on biological (survival and duration of developmental stages, fecundity and longevity of females, sex-ratio) and demographic parameters (R o , G, r m and λ) of the two main phytophagous mites that attack cassava in Africa,Mononychellus progresivus Doreste andOligonychus gossypii (Zacher), was studied in the laboratory. Experiments were performed simultaneously on the two mite species reared on the same cassava variety (1M20) under controlled conditions: 70±10% r.h. and 12L∶12D. The lower thermal threshold was 13°C forM. progresivus and 11°C forO. gossypii. Both species developed in the range from 22 to 36°C. The shortest development time was obtained at 31°C for both species; it was 7.2 days forM. progresivus and 8.2 days forO. gossypii. Maximum fecundity of both species was recorded at 26°C with 42.1 eggs forM. progresivus and 36.3 eggs forO. gossypii The highest intrinsic rate of increase (r m ) was obtained at 31°C for both species with 0.289 and 0.214 forM. progresivus andO. gossypii, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ammonium repression of the nitrite-nitrate (nasAB) assimilatory operon of Azotobacter vinelandii is enhanced in mutants expressing the nifO gene at high levels (1997)
    Springer
    Molecular genetics and genomics 255 (1997), S. 172-179 
    Details
    ISSN: 1617-4623
    Keywords: Key wordsnasAB ; Chlorate-resistant mutants ; nifO ; Nitrogen fixation mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A number of Tn5 mutants were isolated which were unable to fix nitrogen and showed enhanced ammonium repression of the nitrate/nitrite assimilation genes. They also had reduced nitrate reductase activity under fully inducing conditions. Insertions were localized within the nifB gene, and inability to fix nitrogen was shown to be due to disruption of the nifB gene. However, enhanced ammonium repression proved to be the result of constitutive expression of the downstream nifO gene from an `out' promoter present in Tn5. Our results suggest that molybdenum metabolism might function as a regulatory factor that acts through the nitrate reductase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380050486
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Dynamics of insulin and insulin-like growth factor-I (IGF-I) ovarian receptors during maturation in the brown trout (Salmo trutta) (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 341-349 
    Details
    ISSN: 1573-5168
    Keywords: insulin ; IGF-I ; receptor ; trout ; ovary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In salmonid fishes, the role of insulin and insulin-like growth factor-I (IGF-I) in the regulation of ovarian function is not well understood. Recently, we reported that isolated follicular layers of the preovulatory ovarian follicle of coho salmon (Oncorhynchus kisutch) have specific receptors for insulin and IGF-I and that IGF-I modulates steroid production in the follicular layers. In the present study we have investigated the structural and functional characteristics of insulin and IGF-I receptors in the ovary of brown trout (Salmo trutta) and the changes in insulin and IGF-I binding throughout the reproductive cycle of this species. The specific binding for IGF-I was 8- to 15-fold higher than the specific binding for insulin. IGF-I receptors were also more specific than insulin receptors because unlabeled insulin displaced bound radiolabeled insulin at concentrations 40- to 80-fold lower than unlabeled IGF-I; whereas, unlabeled IGF-I displaced bound radiolabeled IGF-I at concentrations 4000- to 8000-fold lower than unlabeled insulin. Insulin and IGF-I receptors from the brown trout ovary were composed of 120 kDa α-subunits and 90 kDa β-subunits, which underwent autophosphorylation in a concentration-dependent manner. Receptor tyrosine kinase activity was also stimulated in a concentration-dependent manner by insulin and IGF-I. When ovarian insulin and IGF-I binding was determined from mid-vitellogenesis (March) until ovulation (November), maximal binding for both peptides was detected in mid-vitellogenesis and gradually decreased until the end of vitellogenesis (August). In the preovulatory period (October), a small increase of insulin and IGF-I binding was observed. After ovulation, insulin binding was no longer detectable and IGF-I binding was very low. These results suggest that insulin and IGF-I receptors in the salmonid ovary follow the structural pattern described in other vertebrate species and that insulin and IGF-I could be involved in the regulation of ovarian function during reproductive stages other than the preovulatory period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007767605620
    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...