Fungi can use a wide variety of nitrogen sources. In the absence of preferred sources such as ammonium, glutamate, and glutamine, secondary sources, including most other amino acids, are used. Expression of the nitrogen utilization pathways is very strongly controlled at the transcriptional level. Here, we investigated the regulation of nitrogen utilization in the pathogenic yeast Candida parap...

Energy and nitrogen balances were performed in 12 very low birthweight infants fed on either human milk or on a preterm formula. Energy and nitrogen retention were significantly higher in those given the formula feed (p less than 0.05). Highly significant correlations were found between nitrogen intake and nitrogen retention and between energy retention and nitrogen retention (p less than 0.001...

Whole-plant and leaf nitrogen isotope composition are determined by the isotope ratio of the external nitrogen source and physiological mechanisms within the plant. Whole-plant isotope composition can reflect that of the nitrogen source when plant demand exceeds nitrogen supply. Uptake by mycorrhizae can cause the isotope ratio of the plant to deviate from the source. Intra-plant variation in i...

Temporal changes in nitrogen concentrations and stream discharge, as well as sediment and nitrogen losses from erosion plots with different land uses, were studied in an agricultural watershed in the Taihu Lake area in eastern China. The highest overland runoff loads and nitrogen losses were measured under the upland at a convergent footslope. Much higher runoff, sediment and nitrogen losses we...

In order to study the effect of nitrite and nitrate on the performance of microbial fuel cell, a system combining an anaerobic fluidized bed (AFB) and a microbial fuel cell (MFC) was employed for high-strength nitrogen-containing synthetic wastewater treatment. Before this study, the AFB-MFC had been used to treat high-strength organic wastewater for about one year in a continuous flow mode. Th...

Nitrogen exists in soils in many forms and constantly changes from one form to another. The paths that the different forms of nitrogen follow through the ecosystem are collectively called the nitrogen cycle (Figure 1). Understanding how the different pools of nitrogen interact and the processes by which these forms enter and leave the cycle is the subject of continuing study. Nitrogen is found ...

There is no evidence in the literature that nitrogen pentoxide (N205), the highest known oxide of nitrogen, has ever been the subject of a toxicological investigation. This gas rapidly breaks down to give nitrogen dioxide and oxygen, but is known to be stabilized by the presence of ozone, and several investigators (Schumacher and Sprenger, 1929; Johnston, 1951) have studied the complex system o...