Results 41 to 50 of about 95,714 (157)

Elementary Isotopic Analysis: Determination of Nitrogen [PDF]

Nature, 1947
We have recently described an isotopic method for the determination of oxygen1 and carbon2 in organic compounds by using heavy oxygen (O18) and carbon (C13) respectively in conjunction with a mass spectrometer. Using the same method, higher precision is possible in the determination of nitrogen and hydrogen, since N15 and H2 (deuterium) are available ...
A D, KIRSHENBAUM, S G, HINDIN, A V, GROSSE   +2 more
openaire   +2 more sources

Tree growth acceleration and expansion of alpine forests: The synergistic effect of atmospheric and edaphic change. [PDF]

, 2016
Many forest ecosystems have experienced recent declines in productivity; however, in some alpine regions, tree growth and forest expansion are increasing at marked rates.
Horwath, William R, Liang, Qianlong, Silva, Lucas CR, Sun, Geng, Wu, Ning, Zhu-Barker, Xia   +5 more
core   +2 more sources

First ice core records of NO3− stable isotopes from Lomonosovfonna, Svalbard [PDF]

, 2014
Samples from two ice cores drilled at Lomonosovfonna, Svalbard, covering the period 1957–2009, and 1650–1995, respectively, were analyzed for NO3− concentrations, and NO3− stable isotopes (δ15N and δ18O).
Björkman, M. P., Isaksson, E., Kaiser, J., Marca, A., Martma, T., Pettersson, R., Pohjola, V. A., Samyn, D., Vega, C. P.   +8 more
core   +1 more source

Stable isotope analysis provides new information on winter habitat use of declining avian migrants that is relevant to their conservation [PDF]

, 2012
Winter habitat use and the magnitude of migratory connectivity are important parameters when assessing drivers of the marked declines in avian migrants. Such information is unavailable for most species.
BJM Stutchbury, BN Smith, C Eraud, C Fry, CM Perrins, CP Chamberlain, D Lack, D Norman, DI Pearson, DJ Pain, DS Wilcove, E Yohannes, FJ Sanderson, G Gory, GD Farquhar, GJ Morel, I Burfield, I Newton, JA Grey, Jason Newton, JC Sealy, JC Vogel, JF Kelly, JM Neto, John W. Mallord, JR Ehleringer, K Risely, KA Hobson, Karl L. Evans, KL Evans, L Jenni, L Svensson, L Zwarts, LA Hill, M Cardillo, M Schaub, MB Hernquist, MJA Werger, MS Webster, N Cooper, N Saino, Ofer Ovadia, P Chantler, P Marra, RA Robinson, RF Inger, RP Ellis, S Bearhop, S Bensch, S Oppel, S Shultz, SD Newsome, SH Ambrose, Shai Markman, T Szép, T Szép, TB Coplen, TB Oatley, TS Reichlin, WJ Peach   +59 more
core   +4 more sources

Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites [PDF]

, 2015
Increasing reactive nitrogen (N-r) deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of N-r to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define ...
Aanes R., Alina Marca, Amoroso A., Atkin O.K, Beaudon E., Beine H.J., Björkman M.P, Björkman M.P., Björkman M.P., Blunier T., Bottenheim J.W., Brimblecombe P., Burkhart J.F., Carmen P. Vega, Carroll M.A., Casciotti K.L., Coplen T.B., Dibb J.E., Dickson L.G, Draxler R.R., Elisabeth Isaksson, Eneroth K., Felix J.D., Forsström S., Freyer H.D, Freyer H.D., Førland E.J., Gibbons J.D., Goto-Azuma K., Hastings M.G, Hastings M.G., Hastings M.G., Heaton T.H.E, Heaton T.H.E., Hisdal V, Honrath R.E., Honrath R.E., Jan Kaiser, Jarvis J.C., Kahl J.D.W., Kaiser J., Kang S., Kekonen T., Kühnel R., Kühnel R., Li D., Liu S.C., Mats P. Björkman, Michalski G., Morin S., Morin S., Morin S., Morin S., Mosier A.R., Nuth C., Pohjola V.A., Rickard Pettersson, Rinnan R., Ruggirello R.M., Röthlisberger R., Samyn D., Schuler T.V., Semb A., Shaver G.R., Stohl A., Tõnu Martma, Vega C.P., Veijo A. Pohjola, Wolff E.W, Xu L.   +69 more
core   +2 more sources

Nitrogen isotopic analyses by isotope-ratio-monitoring gas chromatography / mass spectrometry [PDF]

Journal of the American Society for Mass Spectrometry, 1994
Amino acids containing natural-abundance levels of 15N were derivatized and analyzed isotopically using a technique in which individual compounds are separated by gas chromatography, combusted on-line, and the product stream sent directly to an isotope-ratio mass spectrometer. For samples of N2 gas, standard deviations of ratio measurement were better
Merritt, Dawn A., Hayes, J.M.
openaire   +3 more sources

The fate of nitrogen in the Zarin-Gol River receiving trout farm effluent

Scientific Reports, 2023
This study investigated the Zarrin-Gol River ecosystem in Iran to trace organic matter in the food web and evaluate the impact of aquaculture farm effluent using stable isotopes of nitrogen (δ15N) and carbon (δ13C).
Altin Ghojoghi, Rasoul Ghorbani, Rahman Patimar, Abdolrassoul Salmanmahiny, Rahmat Naddafi, Abdolazim Fazel, Timothy D. Jardine   +6 more
doaj   +1 more source

Different Responses in Root Water Uptake of Summer Maize to Planting Density and Nitrogen Fertilization

Frontiers in Plant Science, 2022
Modifying farming practices combined with breeding has the potential to improve water and nutrient use efficiency by regulating root growth, but achieving this goal requires phenotyping the roots, including their architecture and ability to take up water
Yang Gao, Jinsai Chen, Guangshuai Wang, Zhandong Liu, Weihao Sun, Yingying Zhang, Xiaoxian Zhang   +6 more
doaj   +1 more source

Food fit for a Khan: Stable isotope analysis of the elite Mongol Empire cemetery at Tavan Tolgoi, Mongolia [PDF]

, 2014
The creation and expansion of the Mongol Empire during the thirteenth century A.D. brought with it many changes, both for the conquered peoples and for the conquerors themselves.
Fenner, Jack, Khatanbaatar, Dorjpurev, Tumen, Dashtseveg   +2 more
core   +2 more sources

Nitrogen isotopes link mycorrhizal fungi and plants to nitrogen dynamics [PDF]

New Phytologist, 2012
SummaryIn this review, we synthesize field and culture studies of the 15N/14N (expressed as δ15N) of autotrophic plants, mycoheterotrophic plants, parasitic plants, soil, and mycorrhizal fungi to assess the major controls of isotopic patterns. One major control for plants and fungi is the partitioning of nitrogen (N) into either 15N‐depleted chitin ...
Hobbie, Erik A., Hogberg, Peter
openaire   +3 more sources