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Interpretation of carbon isotope records from late Quaternary planktonic foraminifers are confounded due to the presence of a significant physiological component in the carbon isotopic signal. A quantitative carbon isotope (QC) model is presented which relates the carbon isotopic composition of a foraminiferal shell to the physiological processes of respiration and symbiont photosynthesis and to the /5•3C value of seawater ZCO2. The QC model is calibrated with phySiological and stable isotopic data from laboratory experiments with living planktonic foraminifers. Model simulations of chamber and shell •5•3C values with the symbiont-bearing foraminifers, Orbulina universa and Globigerinoides sacculifer, suggest (1) variations in symbiont density and photosynthetic rate (light level or habitat depth) are the primary physiological parameters controlling intraspecific carbon isotopic variability in these species, (•) respiration has little effect on the /5•C of . universa, and (3) each chamber in a multichambered foraminiferal test will have a distinct value depending on its position in the test whorl. Size:•5•C value relationships reported for G. sacculifer from fossil assemblages can be explained as a function of increasing symbiont density during ontogenetic development. Experimental ecology of the temperate scleractinian coral Astrangia danae, II, Effect of temperature, light intensity, and symbiosis with zooxanthellae, Mar. Biol., 76, 136-148, 1983. JCrgensen, B.B., J. Erez, N.P. Revsbech, and Y.P. Cohen, Symbiotic photosynthesis in the planktonic foraminifera, Globigerinoides sacculifer (Brady), studies with microelectrodes, Limnol. Oxygen and carbon isotopes of individual shells of planktonic foraminifera from Ontong-Java Plateau, equatorial Pacific, Palaeogeogr. Palaeoclimatol. Palaeoecol., 33, 193-204, 1981. Kuile, B., and J. Erez, Uptake of inorganic carbon and internal cycling in symbiont-bearing benthonic foraminifera, Mar. Biol., 94, 499-509, 1987. McConnaughey, T., 13C and 180 isotopic disequilibrium in biological carbonates, II, In vitro simulation of kinetic isotope effects, Geochim. Resource partitioning by reef corals as determined 'from stable isotope composition I. •13C of zooxanthellae and animal tissue vs depth, Mar. Biol., 100, 185-193, 1989. Muthiga, N.A., and A.M. Szmant, The effects of salinity stress on the rates of aerobic respkation and photosynthesis in the hermatypic coral Siderastrea siderea, Biol. Bull., Woods Hole Mass., 173, 539-551. 1987. Nier, A.O., A redetermination of the relative abundances of the isotopes of carbon, nitrogen, oxygen, argon and potassium, Phys. Rev., 77, 789-793, 1950.

Equations are set up to describe the quasilinear behavior of a collisionless, relativistic plasma immersed in a uniform, homogeneous magnetic field. Use of the adiabatic assumption, together with an approximation to resonant denominators, enables an estimate to be given of the change of the distribution function due to the turbulent waves. In the particular cases of pure electrostatic waves, magneto-sonic waves, and cyclotron waves, estimates are made of the rate of energy change of resonant particles. It is shown that some modes exhibit resonant diffusion only when relativistic particles are present and for which there is no nonrelativistic counterpart. It is believed that this calculation may be of some interest in situations where relativistic particles play, or are suspected of playing, a major role; for example, the galactic cosmic ray gas and nonthermal radio sources.