Development within the cleidoic egg of birds and reptiles presents the embryo with the problem of accumulation of wastes from nitrogen metabolism. Ammonia derived from protein catabolism is converted into the less toxic product urea or relatively insoluble uric acid. The pattern of nitrogen excretion of the green iguana, Iguana iguana, was determined during embryonic development using samples f...

Elevation of the blood urea nitrogen following massive hemorrhage from the stomach and duodenum is a frequent occurrence (1). Its mechanism is not the same as that associated with high intestinal obstruction, as it occurs in the absence of any vomiting (2) (e.g. in the presence of melena alone4), and is associated with a normal or increased blood chloride concentration (3, 4, 5) and a normal ca...

Field and laboratory experiments were designed to determine the differential growth and toxin response to inorganic and organic nitrogen additions in Pseudo-nitzschia spp. Nitrogen enrichments of 50 mM nitrate (KNO3), 10 mM ammonium (NH4Cl), 20 mM urea and a control (no addition) were carried out in separate carboys with seawater collected from the mouth of the San Francisco Bay (Bolinas Bay), ...

I. The interaction between nitrogen and water intake was studied in two ewes and two red deer hinds. They were given pelleted diets, at maintenance level, containing equal amounts of roughage but either rich or poor in nitrogen. The deer received 5 0 yo more food than the sheep. Water was given either in large amounts (sheep 5.0 1, deer 7.0 1 daily) or in small amounts (sheep 1.1 1, deer 2.4 1 ...

BACKGROUND Although there are several published estimates of the endogenous amino acid composition of ileal digesta in humans, to our knowledge, there are no systematic studies of ileal digesta endogenous proteins. OBJECTIVES We determined the nature and composition of endogenous nitrogen-containing substances lost from the upper digestive tract of humans. DESIGN Digesta were collected from...

The value of milk on the open market is linked to its protein content, and standard methods for protein analysis rely on a simple nitrogen assay, with the protein concentration inferred from the nitrogen content. Consequently, the addition of chemicals rich in nitrogen, such as urea, can artificially increase the apparent protein content and thus the price demanded. Urea occurs naturally in mil...

in order to evaluate the effects of ethephon and nitrogen fertilizer on sweet sorghum cv. sofra, an experiment was conducted as split plot on a randomized complete block design with three replications at agricultural research station of isfahan university (isfahan, iran). experiment was conducted with four nitrogen levels (0, 100, 200 and 300 kg urea ha-1 from urea with 0, 46, 92 and 138 kg nit...