Nitrogen availability

THF into the sep funnel. It is recommended that an iodine crystal is placed in the reaction flask and before the condenser is attached, nitrogen should be blown Into the receiving flask to remove any air. As / didn t have any nitrogen available I skipped this step but I did place one small crystal of iodine into the reaction flask. When the iodine is added the solvent will begin to turn brown. Although this looks like the iodine is just dissolving it would appear from what I have read that this is also caused by the reaction. 

The natural supply of nitrogen available to plants from the nitrogen cycle is limited. To meet the growing demands for agriculture crops, nitrogen is added to soil in the form of fertilizers. An estimated one-third of the human population is fed as a result of the use of synthetic fertilizers. 

Protein stress and recycling of nitrogen could also have the opposite effect, however. If less N-depleted N is excreted as inea, then there should be less overall enrichment in the nitrogen available for tissue synthesis. Moreover, if urea itself is recycled for protein synthesis under protein stress, which often occurs in herbivores, then the diet-tissue difference should be smaller than in unstressed individuals because urea has a substantially lower 8 N value than the diet. 

Regulation of amino acid permease activity as a function of nitrogen availability... 

S. Sehmidt and G. R. Stewart, Waterlogging and fire impacts on nitrogen availability and utilization in a subtropical wet heathland (wallum). Plani Cell Environ. 20 1231 (1997). 

G. P. Robertson, M. A. Huston, F. C. Evans, and J. M. Tiedje, Spatial variability in a successional plant community patterns of nitrogen availability. Ecology 69 1517 (1988). 

The Nitrogen Availability Assay [376] consists of growth tests under defined conditions using mineral salts medium and organonitrogen compounds as sources of carbon and/or nitrogen. Probe molecules include quinoline, pyridine, carbazole, and porphyrin. Growth tests are performed using six conditions ... 

High seeding density as well as high nitrogen availability should be avoided because it results in dense crop stands with a favourable microclimate for fungal growth. 

Keeney DR (1982) Nitrogen-availability indices. In Page AL, Miller RH, Keeney DR (eds) Methods of soil analysis. Part 2 Chemical and microbiological properties. Am Soc Agron, Madison, Wisconsin, pp 711-733... 

M. Khatipov, J. Miyake, M. Miyake, Y. Asada (1998) Polyhydroxybutyrate accumulation and hydrogen evolution by Rhodobacter sphaeroides as a function of nitrogen availability, BioHydrogen, edited by Zaborsky et al. 

Binkley D, Matson E Ion exchange resin bag method for assessing forest soil nitrogen availability. Soil Sci. Soc. Am. J. 1983 47 1050-1052. 

Grams of nitrogen available from protein sources is calculated as follows ... 

Arnold TM, Tanner CE, Hatch WI (1995) Phenotypic variation in polyphenolic content of the tropical brown algae Lobophora variegata as a function of nitrogen availability. Mar Ecol Prog Ser 123 177-183... 

Henley WJ, Levavasseur G, Franklin LA, Osmond CB, Ramus J (1991) Photoacclimation and photoinhibition in Ulva rotimdataas influenced by nitrogen availability. Planta 184 235-243... 

Fragoyiannis, D. A., McKinlay, R. G., D Mello, J. P. F. (2001). Interactions of aphid herbivory and nitrogen availability on the total foliar glycoalkaloid content of potato plants. J. Chem. EcoL, 27, 1749-1762. 

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