Seeds of three C₃ and one C₄ annual weedy species were collected from agricultural fields in Beltsville, Maryland in 1966 and 2006, when atmospheric CO₂ concentrations averaged about 320 and 380 mmol mol^-1, respectively. Plants from each collection year were grown over a range of CO₂ concentrations to test for adaptation of these weedy species to recent changes in atmospheric CO₂. In all three of the C₃ species, the increase in CO₂ concentration from 320 to 380 mmol mol^-1 increased total dry mass at 24 days in plants from seeds collected in 2006, but not in plants from seeds collected in 1966. Shoot and seed dry mass at maturity was greater at the higher growth CO₂ in plants collected in 2006 than in 1966 in two of the species. Down regulation of photosynthetic carboxylation capacity during growth at high CO₂ was less in the newer seed lots than in the older in two of the species. Overall, the results indicate that adaptation to recent changes in atmospheric CO₂ has occurred in some of these weedy species.

The reaction mechanism of the carboxylation of K-2-naphthoxide was investigated by density functional theory calculations and spectroscopic studies. The reaction intermediates and products were confirmed by CO₂ adsorbed-FTIR and ¹H-NMR measurements. Four steps of the reaction pathway were identified: CO₂ activation, electrophilic substitution, CO₂-K complex rearrangement, and H-shift, producing 2-hydroxy-1-naphthoic acid (2,1-HNA), 2-hydroxy-3-naphthoic acid (2,3-HNA), and 2-hydroxy-6-naphthoic acid (2,6-HNA). The occurrence of CO₂-K complex rearrangement was also confirmed. These energy profiles of reaction pathways for the reaction intermediates were well consistent the experimental results on the carboxylation of K-2-naphthoxide.

Aerobic glycolysis in cancer cells, originally observed by Warburg 100 years ago, which involves production of lactate as the end product of glucose breakdown even in the presence of adequate oxygen, is the foundation for the current interest in cancer cell-specific reprograming of metabolic pathways. The renewed interest in cancer cell metabolism has now gone well beyond the original Warburg effect related to glycolysis to other metabolic pathways to include amino acid metabolism, one-carbon metabolism, pentose phosphate pathway, nucleotide synthesis, antioxidant machinery, etc. Since glucose and amino acids constitute the primary nutrients that fuel the altered metabolic pathways in cancer cells, the transporters that mediate the transfer of these nutrients and their metabolites not only across the plasma membrane but also across the mitochondrial and lysosomal membranes have become an integral component of expansion of the Warburg effect. In this review, we focus on the interplay between these transporters and metabolic pathways that facilitates the metabolic reprogramming which has become the hallmark of cancer cells. The beneficial outcome of this recent understanding of the unique metabolic signature surrounding the Warburg effect is the identification of novel drug targets for development of a new generation of therapeutics to treat cancer.