Carbon (C/C) and nitrogen (N/N) stable isotope ratios were longitudinally measured in human hair that reflected the period from pre-conception to delivery in 10 pregnant women. There was no significant change in the dC results, but all subjects showed a decrease in dN values ( 0.3 to 1.1%) during gestation. The mechanisms causing this decrease in hair dN have not been fully elucidated. However,...

‘Ihe Ipswich River is a low-gradient, coastal river in northeastem Massachusetts. It is about 55 km long and drains an area of 401 km’. Previous observations and studies indicate high levels of dissolved inorganic nitrogen (DIN) in the headwaters of the river due to urban and residential land use (1). However, concentrations drop quickly with distance downstream, presumably due to biological pr...

Energy balance, nitrogen balance, and growth studies were done in 37 preterm infants (20 of very low birthweight) who were fed on expressed breast milk or on one of 3 formulae each of different composition, including a special premature formula and a highly adapted 'humanised' formula. The variability of breast milk composition was such that it would have been difficult to predict the infants' ...

Drought stress triggers mature leaf senescence, which supports plant survival and remobilization of nutrients; yet leaf senescence also critically decreases post-drought crop yield. Drought generally results in carbon/nitrogen imbalance, which is reflected in the increased carbon:nitrogen (C:N) ratio in mature leaves, and which has been shown to be involved in inducing leaf senescence under nor...

The balance between nitrogen loading and runoff in the forested headwater streams of the Kanna River was estimated to elucidate the current status of nitrogen saturation in a forested watershed. NO3-N concentration in the study area was far higher than the average value in Japan. Estimated nitrogen runoff accounted for 55–57% of nitrogen loading; suggesting that the forest’s nitrogen retention ...

Experiments to determine the comparative nutritive value of partial acid hydrolysates of various proteins have been carried out for several years in this laboratory. Most of this work has involved studies of nitrogen balance in dogs wherein the hydrolysates were administered intravenously. Short term experiments, i.e. 4 to 5 days, were used to determine minimum nitrogen levels at wb.ich the N b...

Many elderly people have a low intake of dietary protein, yet their protein requirement may be higher than the current Recommended Dietary Allowance. High-quality protein supplements may be useful to enhance nitrogen retention and increase the availability of essential amino acids in elderly people. We compared the nitrogen balance of two protein supplements (Resource Beneprotein Instant Protei...

The nitrogen balance technique is widely used for protein metabolism studies and in this laboratory is being applied to research on interrelationships between diet and disease (Squibb, 1961). Recently, however, the experimental error resulting from N losses during N balance experiments has been stressed and the integrity of some N balance data questioned (Wallace, 1959). In this report the N re...

Constructed wetlands could be components of low-tech systems to treat and reuse wastewater in arid region. A key function of the wetland would be to provide additional N removal. To improve design criteria, a sequential model of nitrogen transformations (organic N! ammonium; ammonium!nitrate; nitrate!nitrogen gas) was successfully calibrated and verified for a wetland in Kingman, Arizona. A seq...