Plants using the C3 and C4 photosynthetic pathways differ in carbon-isotope composition, and this difference offers a means to estimate the relative abundance of these two functional groups in the palaeorecord. We report here results of a study aiming to evaluate pollen dC (dCp) of Poaceae (the grass family) as a proxy indicator for palaeoecological studies. On average dCp differs by /13 betwee...

During the last ice age, CO2 concentration ([CO2]) was 180-200 micromol/mol compared with the modern value of 380 micromol/mol, and global temperatures were approximately 8 degrees C cooler. Relatively little is known about the responses of C3 and C4 species to long-term exposure to glacial conditions. Here Abutilon theophrasti Medik. (C3) and Amaranthus retroflexus L. (C4) were grown at 200 mi...

OBJECTIVE To analyze serum C3 and C4 complement system components with a view to their possible utility as biomarkers of intermittent atopic asthma. METHODS Serum levels of the C3 and C4 complement components were assayed in 70 children aged from 3 to 14 years and with a history of "wheezy chest." After 2 years' outpatients follow-up and after application of inclusion and exclusion criteria, ...

studies were undertaken to evaluate content of igg, igm, c3, c4, ch50 and proteines of sera from 53 drug addicts by immunological methods. results shows an increase of igg and no significant variatrion in the level of other ig(s). in the same time we have seen an augmentation of gamma globuline in the protein electrophoresis pattern. the level of c3 and c4 of complement component rest unchanged.

We analyzed the dC of soil organic matter (SOM) and fine roots from 55 native grassland sites widely distributed across the US and Canadian Great Plains to examine the relative production of C3 vs. C4 plants (hereafter %C4) at the continental scale. Our climate vs. %C4 results agreed well with North American field studies on %C4, but showed bias with respect to %C4 from a US vegetation database...

Highly purified and radioiodinated human C4 and (or) C3 were administered to patients with renal allografts in rejection, with hereditary angioedema (HAE), with chronic glomerulonephritis, and to control subjects. The latter group included normal individuals, anephric patients before transplantation, and stable renal allograft recipients. The catabolic rates of these complement proteins were de...