Fractionation of carbon isotopes in oxygenic photosynthesis product 3-phosphoglycerate is depleted in C due to the kinetic isotope effect of the above reaction. The overall C fractionation for C3 photosynthesis ranges between -20 to -37‰. The wide range of variation in delta values expressed in C3 plants is modulated by the stomatal conductance, or the rate of CO entering, or water vapor exiting, the small pores in the epidermis of a leaf. The δC of C3 plants depends on the relationship between stomatal conductance and photosynthetic rate, which is a good proxy of water use efficiency in the leaf. C3 plants with high water-use efficiency tend to
What I Need What I Need "What I Need" is a song by American recording artist Ray J. It was written by Rodney "Darkchild" Jerkins, LaShawn Daniels, Fred Jerkins III, and Ray J for his 2005 album "Raydiation", while production was handled by the former. Released as the second single from the album following "One Wish", it reached number 58 on "Billboard"s Hot R&B/Hip-Hop Songs chart. "What I Need" earned generally positive reviews by critics. "Billboard" magazine felt that the song "should be enough to momentum. Here, Ray J's vocals once again seem strained as he cops another plea to the woman he