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Davies, A.

Publications and source records attributed to Davies, A..

36 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Antigen S1, encoded by the MIC1 gene, is characterized as an epitope of human CD59, enabling measurement of mutagen-induced intragenic deletions in the AL cell system

S1 cell membrane antigen is encoded by the MIC1 gene on human chromosome 11. This antigen has been widely used as a marker for studies in gene mapping or in analysis of mutagen-induced gene deletions/mutations, which utilized the human-hamster hybrid cell-line, AL-J1, carrying human chromosome 11. Evidence is presented here which identifies S1 as an epitope of CD59, a cell membrane complement inhibiting protein. E7.1 monoclonal antibody, specific for the S1 determinant, was found to react strongly with membrane CD59 in Western blotting, and to bind to purified, urinary form of CD59 in ELISAs. Cell membrane expression of S1 on various cell lines always correlated with that of CD59 when examined by immunofluorescent staining. In addition, E7.1 antibody inhibited the complement regulatory function of CD59. Identification of S1 protein as CD59 has increased the scope of the AL cell system by enabling analysis of intragenic mutations, and multiplex PCR analysis of mutated cells is described, showing variable loss of CD59 exons.

Non-NASA Center↗
NASA NTRS1999

Active Volcanism on IO: Global Distribution and Variations in Activity

Io's volcanic activity has been monitored by instruments aboard the Galileo spacecraft since June 28, 1996. We present results from observations by the Near-Infrared Mapping Spectrometer (NIM) for the first ten orbits of Galileo, correlate them with results from the Solid State Imaging System (SSI)and from ground-based observations, and compare them to what was known about Io's volcanic activity from observations made during the two Voyager fly-bys in 1979.

near-infrared mapping spectrometry solid state ima↗
NASA NTRS1996

Near-Infrared Spectroscopy and Spectral Mapping of Jupiter and the Galilean Satellites: Results from Galileo's Initial Orbit

The Near Infrared Mapping Spectrometer performed spectral studies of Jupiter and the Galilean satellites during the June 1996 perijove pass of the Galileo spacecraft. Spectra fora5-micrometer hotspot on Jupiter are consistent with the absence of a significant watercloud above 8 bars and with a depletion of water compared to that predicted for solar composition, corroborating results from the Galileo probe. Great Red Spot (GRS) spectral images show that parts of this feature extend upward to 240 millibars, although considerable altitude-dependent structure is found within it. A ring of dense clouds surrounds the GRS and is lower than it by 3 to 7 kilometers. Spectra of Callisto and Ganymede reveal a feature at 4.25 micrometers, attributed to the presence of hydrated minerals or possibly carbon dioxide on their surfaces. Spectra of Europa's high latitudes imply that fine-grained water frost overlies larger grains. Several active volcanic regions were found on lo, with temperatures of 420 to 620 kelvin and projected areas of 5 to 70 square kilometers.

Carlson, R.↗