Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Life and Medical Sciences  (2)
  • Mutagenesis  (2)
  • Neisseria gonorrhoeae  (2)
  • Britain  (1)
  • Conservation  (1)
  • Karst landforms  (1)
Materialart
Erscheinungszeitraum
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Environmental geology 21 (1993), S. 167-172 
    ISSN: 1432-0495
    Schlagwort(e): Limestone quarrying ; Karst landforms ; Geomorphological processes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract Limestones have been worked for many thousands of years — initially for building stone and agricultural lime and more recently for a wide range of construction and industrial uses. In most industrialized countries limestone quarries represent the most visually obvious and, in both process and landform terms, the most dramatic anthropogenic impact on karst terrain. However, quarrying has, to date, received surprisingly little attention from karst scientists. Research in the English Peak District suggested that the postexcavation evolution of quarried limestone rock faces was in part a result of the methods used in their excavation, and this led to the development of a technique designed to reduce the visual and environmental impacts of modern quarries by “Landform replication. ” This involves the use of controlled “restoration blasting” techniques on quarried rock slopes to construct a landform sequence similar to that in the surrounding natural landscape. The constructed landforms are then partially revegetated using appropriate wildflower, grass, and/or tree species.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Environmental geology 28 (1996), S. 121-127 
    ISSN: 1432-0495
    Schlagwort(e): Key words Limestone caves ; Conservation ; Agriculture ; Recreation ; Britain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract  Limestone caves are an important scientific and recreational resource in Britain. During the mid- to late 1970s, cavers and statutory conservation bodies cooperated in a review of cave resources which resulted in the designation of 48 caves or cave areas as Sites of Special Scientific Interest (SSSI). During the same period, the Wildlife and Countryside Act 1981 was introduced to provide more effective planning controls on activities such as agriculture carried out within SSSI boundaries. In one case, at Priddy in the Mendip Hills of Somerset, landowners prevented access to a number of caves in protest over the new, tougher restrictions on agriculture. Faced with the closure, and perceiving that their recreational use of caves might also be controlled, local cavers joined the landowners in opposing the proposals for SSSI designation. As a result the proposals were reviewed, three caves were excluded from the site and controls on the remaining area were relaxed. The case emphasized a need for an effective system to take account of all factors affecting cave conservation, a need which has led to a more constructive dialogue between nature conservation bodies, caver organizations and other interested parties.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 251 (1996), S. 509-517 
    ISSN: 1617-4623
    Schlagwort(e): DNA methyltransferase ; Restriction endonuclease ; Neisseria gonorrhoeae ; Transformation ; Mutagenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A technique that allows for easy identification of transformants ofNeisseria gonorrhoeae in the absence of selective pressure has been developed. A suicide vector that contains a gonococcal DNA uptake sequence was constructed to aid in DNA uptake. In this transformation procedure, a limiting number of cells is incubated with an excess amount of DNA, and the mixture is plated onto a non-selective medium. At least 20% of the resulting colonies contained cells that had been transformed. This strategy was utilized to construct specific deletions of the S.NgoI, II, IV, V and VII restriction-modification (R/M) genes. All five deletions were successfully incorporated into the chromosome of FA19, producing strain JUG029. Strain JUG029 could be transformed with non-methylated plasmid DNA while strain FA19 could not be transformed with such DNA. The development of a simple, non-selective transformation technique, coupled with the construction of a strain that is more permissive for DNA-mediated transformation, will aid in genetic manipulations of the gonococcus.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 251 (1996), S. 509-517 
    ISSN: 1617-4623
    Schlagwort(e): Key words DNA methyltransferase ; Restrictionendonuclease ; Neisseria gonorrhoeae ; Transformation ; Mutagenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  A technique that allows for easy identification of transformants of Neisseria gonorrhoeae in the absence of selective pressure has been developed. A suicide vector that contains a gonococcal DNA uptake sequence was constructed to aid in DNA uptake. In this transformation procedure, a limiting number of cells is incubated with an excess amount of DNA, and the mixture is plated onto a non-selective medium. At least 20% of the resulting colonies contained cells that had been transformed. This strategy was utilized to construct specific deletions of the S.NgoI, II, IV, V and VII restriction-modification (R/M) genes. All five deletions were successfully incorporated into the chromosome of FA19, producing strain JUG029. Strain JUG029 could be transformed with non-methylated plasmid DNA while strain FA19 could not be transformed with such DNA. The development of a simple, non-selective transformation technique, coupled with the construction of a strain that is more permissive for DNA-mediated transformation, will aid in genetic manipulations of the gonococcus.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 87 (1976), S. 79-87 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The ability of two media identically supplemented with serum to maintain functional and structural differentiated properties of cultured malignant liver epithelial cells was compared. Reuber H35 hepatoma cells grown in a complex medium, Medium E, possessed the gluconeogenic enzyme phosphoenolpyruvate carboxykinase and bile canaliculi. When grown in Eagle's Minimal Essential Medium, the activity of phosphoenolpyruvate carboxykinase was reduced and bile canaliculi were not formed. This decrease in properties was restored when cells maintained in Minimal Essential Medium were returned to Medium E. It was concluded that the enhanced phenotypic expression was probably due to enrichment of the nutrient environment.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 105 (1980), S. 335-346 
    ISSN: 0021-9541
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Protein degradation has been measured in confluent monolayers of eleven lines of contact-inhibited cells and ten transformed lines as the rate of release of trichloroacetic acid-soluble radioactivity after prelabeling cell protein with [3H]leucine. Insulin, at concentrations from 10-12 M to 10-6 M, has been added at the beginning of the 4-hour degradation period to detect selective effects of this hormone as an inhibitor of the inducible proteolysis occurring in serumfree medium. In addition insulin binding measurements have been performed on selected cell lines in an attempt to relate receptor properties to insulin action. Substantial effects of insulin are found in most cells with a selective inhibition at low insulin concentrations noted in several of the transformed lines. The difference in insulin sensitivity is not entirely definitive because temperature-sensitive transformation mutants of NRK cells are not more sensitive to insulin at a temperature where they show the transformed phenotype. Although insulin receptors on different cell lines have similar binding properties, two of the hepatomas used, H35 and MH1C1, show inhibition of protein degradation at insulin concentrations where receptor occupancy is extremely low. Calvarial osteoblast-like cells have a high rate of protein degradation which can be reduced by growth factors but not by insulin. The lack of an insulin response is a consequence of poor insulin binding to the cells. Insulin binds to the osteogenic sarcoma cells in substantial amounts. However, its normal action to inhibit the induced proteolysis is restricted because with these cells no increase of proteolysis occurs in serum-free medium. Generally higher rates of protein degradation are observed in the contact-inhibited lines than the transformed cells. We suggest that this difference may provide a selective growth advantage to transformed cells.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...