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A. Parker

Publications and source records attributed to A. Parker.

3 recordsLinked to original sources
USGS2020

Preparing for geophysical science on the surface of the moon enabled by Artemis

Geophysical methods have been extremely successful in identifying resources on Earth as they provide a means of characterizing and mapping the sub-surface using data gathered on and above the target structures. Geophysics on the Moon will be an important tool for identifying key targets for geological prospecting, scientific sampling, assessing hazards and risks to crew and infrastructure, and determining the near subsurface and deeper workings of the lunar interior. Artemis will require 21st century geophysics instruments to advance lunar science and exploration, similar to how Apollo gathered geophysical data that is still leading to scientific discoveries 50 years later.

Report↗
USGS1981

Dark CO2-fixation and diurnal malic acid fluctuations in the submerged-aquatic Isoetes storkii

In the leaves (but not corms) of the submerged aquatic Isoetes storkii malic acid concentration fluctuated from 22 μeg g FW -1 in the evening to 171 μeg g FW -1 in the morning. Associated with this was a change in titratable acidity of 152 μeg g FW -1 between morning and evening. 14 C carbon was fixed in both the light and the dark, though the amount of carbon fixed in the light was more than that fixed in the dark. Autoradiographs show 88% of 14 CO 2 fixed in the dark is recovered after 1 h, in malic acid and the remainder in one other unidentified product, whereas these two products contain less than 15% of the 14 C fixed after 1 h exposure to 14 CO 2 in the light. It is suggested that CAM metabolism in this aquatic species may be related to the low availability of CO 2 for photosynthesis during the day in its aquatic environment and that this metabolic pathway may prove common in the genus Isoetes .

Oecologia↗