A Haxo-Blinks rate-measuring oxygen electrode together with a modulated light source gave an average current signal (change in net Oa exchange) and a modulated current signal (photosynthetic 02 evolution). Using this apparatus, net 02 exchange and photosynthetic 02 evolution at low intensities have been studied in the green alga, Chlamydomonas reinhardi. At both 645 nm and 695 nm, the curves of...

Nitrogenase (EC 1.7.99.2) activity of nodules of cowpea ( Vigna aguiculata IL.1 Walp), maintained under conditions of a 12-hour day at 30°C and 800 to 1,000 microelastelns per square meter per second (photosyntheticaHly active radiation) and a 12-hour night at 20°C, showed a marked diurnal variation with the total electron flux through the enzyme at night being 60% of that in the photoperiod. T...

In the endosomes of APCs, the MHC class II-like molecule H2-M catalyzes the exchange of class II-associated invariant chain peptides (CLIP) for antigenic peptides. H2-O is another class II-like molecule that modulates the peptide exchange activity of H2-M. Although the expression pattern of H2-O in mice has not been fully evaluated, H2-O is expressed by thymic epithelial cells, B cells, and den...

We show the existence of (H2 0 (Ω)×L2(Ω), H2 0 (Ω)×H2 0 (Ω))-global attractors for plate equations with critical nonlinearity when g ∈ H−2(Ω). Furthermore we prove that for each fixed T > 0, there is an (H2 0 (Ω) × L2(Ω), H2 0 (Ω) × H2 0 (Ω))T -exponential attractor for all g ∈ L2(Ω), which attracts any H2 0 (Ω)×L2(Ω)-bounded set under the stronger H2(Ω)×H2(Ω)-norm for all t ≥ T .

A coupled equations approach is used to calculate the probabilities of photophysical processes in the ten photon absorption spectrum of H2 at wavelength A = 532nm At high intensities, ie, I~10~°W/cm~, it is shown that above threshold photodissocianon (ATPD) occurs readily m the B ~3]

Free Oxygen in the Atmospheres of Mars and Venus Mark Allen, Jet Propulsion Laboratory, Califomia Institute Of Technology Yuk L. Yung, California Institute of Technology The study of the terrestrial planets has provided an opportunity to understand the factors controlling the abundance of free oxygen--primarily O2 and O3--in abiotic atmospheres. This experience should be able to guide future as...

Molecular hydrogen (H2) has been accepted to be an inert and nonfunctional molecule in our body. We have turned this concept by demonstrating that H2 reacts with strong oxidants such as hydroxyl radical in cells, and proposed its potential for preventive and therapeutic applications. H2 has a number of advantages exhibiting extensive effects: H2 rapidly diffuses into tissues and cells, and it i...