We then sent the leaf samples to University of California, Irvine, for analysis of carbon isotope ratios
via mass spectrometry (Dawson et al.
A Mann-Whitney U test performed only for data of these two prey species revealed a highly significant difference in their stable carbon isotope ratios
(U = 0.
Summary statistics for stable carbon isotope ratio
where "sample" refers to bromass from the experiment, "control" refers to values calculated from the bulk carbon isotope ratio
(see below), and "standard" refers to acetanilide with a known isotope ratio.
The data of gravimetry as well as carbon isotope ratios
were analyzed for their statistical significance among the genotypes following a completely randomized design by MSTATC software (Anonymous, 1989).
Pierce S, Winter K, Griffiths H (2002) Carbon isotope ratio
and the extent of daily CAM use by Bromeliaceae.
Ehleringer JR, Buchmann N, Flanagan LB (2000) Carbon isotope ratios
in belowground carbon cycle processes.
Carbon isotope ratios
and physiological processes in arid land plants, p.
Correlations between carbon isotope ratio
, water-use efficiency and yield.
And even though the scientists measured the carbon isotope ratio
in filter feeders such as mollusks and sea anemones during midsummer phytoplankton blooms, they found these animals derived an average of nearly 60 percent of their carbon from kelp, the group reports in the July 14 SCIENCE.
The carbon isotope ratio
is difficult to measure in comets, notes astrophysicist Paul Feldman of Johns Hopkins University in Baltimore.
National contract notice: Gas analyzer for the measurement of stable carbon isotope ratios
of methane and carbon dioxide