Age-dependent decreases in human submandibular gland flow rates as measured under resting and post-stimulation conditions.

Submandibular saliva samples were obtained with a new collection device, under resting and post-stimulation conditions, from 28 healthy individuals between 70 and 91 years of age, and from 30 healthy individuals between 18 and 39 years of age. The salivary flow rates were significantly decreased in the aged group compared with the control group. The mean resting and post-stimulation flow rates for the aged group averaged 22% and 39%, respectively, of control values.

Nitrogen fixation associated with 'Park' Kentucky bluegrass (Poa pratensis L.).

Associative nitrogen fixation in Kentucky bluegrass (Poa pratensis L.) turfs inoculated with five nitrogen-fixing bacterial isolates was evaluated using the acetylene reduction assay and nitrogen accumulation as indicators of fixation. 'Park' and 'Nugget' Kentucky bluegrass turfs were grown in controlled environment chambers and inoculated with Klebsiella pneumoniae (W-2, W-6, and W-14), Erwinia herbicola (W-8), and Enterobacter cloacae (W-11).

Nitrogen fixation (acetylene reduction) associated with roots of winter wheat and sorghum in Nebraska.

Root segments and root-soil cores (6.5-cm diameter) from fields and nurseries of winter wheat and sorghum were tested for N2 fixation by using the acetylene reduction assay. Wheat samples (approximately 1,200) from 109 sites generally had low or no activity (0 to 3.