rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: The
    title: energy dependence of mutations produced in Escherichia coli by low doses of x-radiation
  name:
    name part: Bartlett, William Thomas.
    role:
      role term: creator
  name:
    name part: Landmann, Wendell A.
    role:
      role term: degree committee member.
  name:
    name part: Neff, R. D.
    role:
      role term: degree committee member.
  name:
    name part: O'Donovan, Gerard A.
    role:
      role term: degree supervisor.
  name:
    name part: Smith, James D.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: txu
    date issued: 1976
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: ix, 49 leaves : illustrations ; 28 cm
  abstract: Resistance to the proline analogue, azetidine-2-carboxylic acid, was used as a selection technique with E. coli in order to measure the production of mutations caused by low doses of X-radiation. An improved procedure was required to measure the small changes in the mutation rate. Since the Coulter Counter provided a precise estimate of bacterial numbers, it was found to be essential in this procedure. In addition, a system for producing K X-rays and highly filtered X-rays was developed. This system produced X-rays of good homogeneity whose quality could easily be defined. Bacterial cultures received exposures from 10 R to 138 R at various energies from 29 keV to 88 keV. X-ray exposure at the 29 keV energy produced a significant increase in the bacterial mutation rate. Exposure at 37 keV and 58 keV caused a significant decrease in the bacterial mutation rate. Bacterial cultures showing logarithmic growth were much more sensitive to irradiation than cultures in a non-growing state. Mutants were characterized by reversion with the alkylating agent ethyl methane sulfonate (EMS) and the less specific, but more potent, agent N-methyl-N'-nitro-N-nitrosoguanidine (NTG). EMS reverted the spontaneously occurring mutants and those produced by exposure to 29 keV X-rays more readily than mutants produced by exposure to higher energy X-rays. No correlation was observed with NTG reversion. The data in these experiments indicate that the rate and type of mutations produced by low doses of X-rays were energy dependent.
  note: Vita.
  note: Texas A & M University
  note: Includes bibliographical references (leaves 42-46).
  subject:
    topic: Bacterial genetics
    topic: Experiments
  subject:
    topic: Escherichia coli
  subject:
    topic: X-ray mutagenesis
  subject:
    topic: Major biochemistry
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-472525
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-472525
  record info:
    record content source: TXA
    record creation date: 770513
    record change date: 20220103135049.0
    record identifier: in00000448233
    language of cataloging:
      language term: eng