Soybean aphid (Aphis glycines Matsumura) is a pest of soybean in the northern Midwest whose migratory patterns have been difficult to quantify. Improved knowledge of soybean aphid overwintering sites could facilitate the development of control efforts with exponential impacts on aphid densities on a regional scale. In this preliminary study, we explored the utility of variation in stable isotop...

We report the measurement of the natural isotope ratios of nitrogen and carbon in subcellular volumes of individual cells among a population of cultured cells using a multi-isotope imaging mass spectrometer (MIMS), [MIMS is the prototype of the NanoSIMS 50, Cameca, France.] We also measured the nitrogen and carbon isotope ratio in cells after they had been cultured in media enriched with the am...

Two novel compounds, 2-methyl, 4-carboxy, 5-hydroxy-3,4,5,6-tetrahydropyrimidine (THP(A] and 2-methyl, 4-carboxy-3,4,5,6-tetrahydropyrimidine (THP(B] have been identified in the pool of Streptomyces parvulus by in vivo and in vitro studies. 13C and 15N were introduced into the compounds by feeding S. parvulus with 15N- and 13C-labeled L-glutamate. High resolution 13C and 15N NMR have been appli...

Magic-angle spinning (MAS) solid-state nuclear magnetic resonance (SSNMR) spectroscopy is rapidly developing as a technique for the atomic-level characterization of structure and dynamics of biomacromolecules not amenable to analysis by X-ray crystallography or solution NMR.1-5 While nearly complete resonance assignments have been achieved for multiple 13C,15N-enriched proteins up to ∼100 aa,1,...

Stable isotope labeling of pollutants is a valuable tool to investigate their environmental transport and degradation. For the globally most frequently used herbicide glyphosate, such studies have, so far, been hampered by absence an analytical standard for its labeled metabolite AMPA-15N, which formed during degradation all commercially available glyphosate isotopologues. Without standard, det...

A sample of Escherichia coli-expressed human N-RAS-encoded p21, a 21-kDa protein, was selectively labeled with 15N at each of the 14 glycine amide positions. Two-dimensional proton-observe 15N correlation spectra showed one peak for each glycine residue. Five glycine resonances were identified with residues near the nucleotide binding site and provide useful reporters of several oncogene-activa...

Ultrahigh resolution l5N NMR spectra were measured for two nitroalkanes (MeNÜ2 la, fBuN02 lc), two isocyanates (;BuNCO 2c, Me^SiNCO 2d), four isothiocyanates (MeNCS 3a, EtNCS 3b, 'BuNCS 3c, M e3SiNCS 3d), one carbodiimide (Me3 SiNCNSiMe3 4d), one keteneimine [Me3 SiNCC(SiMe3 ) 2 5d], two sulphinyl imides ('BuNSO 6c, Me3 SiNSO 6d), and N-terf-butyl-pyrrole 7c, in order to determine coupling cons...

Increasing anthropogenic pollution from urban centers and fossil fuel combustion can impact the carbon and nitrogen cycles in forests. To assess the impact of twentieth century anthropogenic pollution on forested system carbon and nitrogen cycles, variations in the carbon and nitrogen isotopic compositions of tree-rings were measured. Individual annual growth rings in trees from six sites acros...

reprintInfo.asp. DOI: 10.1525/cond.2010.090186 Resumen. En el futuro, deseamos usar análisis de isótopos estables de plumas de vuelo para entender el comportamiento alimenticio de aves marinas pelágicas como Pterodroma sandwichensis y Puffinus auricularis newelli. El análisis de las rémiges es particularmente informativo porque generalmente se conoce la secuencia y el momento en que ocurre la m...