IDEALLY, THE EVALUATION of acid-base balance should be made from the determination of 002 content and pH on arterial plasma. Obtaining arterial blood is not, however, a routine clinical procedure. Hence, next in order of preference is the performance of these two determinations on plasma of arterialized blood which may be easily obtained by soaking the arm of the subject in a water bath at 40#{...

Past, present, and possible future changes in the Baltic Sea acid-base and oxygen balances were studied using different numerical experiments and a catchment-sea model system in several scenarios including business as usual, medium scenario, and the Baltic Sea Action Plan. New CO2 partial pressure data provided guidance for improving the marine biogeochemical model. Continuous CO2 and nutrient ...

CO 3 concentration and pCO2 thresholds for calcification and dissolution on the Molokai reef flat, Hawaii K. K. Yates and R. B. Halley U.S. Geological Survey, Center for Coastal and Watershed Studies, St. Petersburg, FL 33701, USA Received: 5 December 2005 – Accepted: 22 December 2005 – Published: 31 January 2006 Correspondence to: K. K. Yates ([email protected]) © 2006 Author(s). This work is li...

Observed atmospheric concentrations of CO(2) and data on the partial pressures of CO(2) in surface ocean waters are combined to identify globally significant sources and sinks of CO(2). The atmospheric data are compared with boundary layer concentrations calculated with the transport fields generated by a general circulation model (GCM) for specified source-sink distributions. In the model the ...

In nature, H2- and CO2-utilizing methanogenic archaea have to couple the processes of methanogenesis and autotrophic growth under highly variable conditions with respect to the supply and concentration of their energy source, hydrogen. To study the hydrogen-dependent coupling between methanogenesis and growth, Methanothermobacter thermautotrophicus was cultured in a fed-batch fermentor and in a...

We report here the results of a multi-proxy study to reconstruct surface water pCO2 concentrations in the northern Arabian Sea. Our results show that δB and Mg/Ca measurements of the planktonic foraminifer Globigerinoides sacculifer yield consistent pCO2 values with those reconstructed from the δC of alkenones when used in

Recently reported increasing calcification rates and primary productivity in the coccolithophore Emiliania huxleyi were obtained by equilibrating seawater with mixtures of carbon dioxide in air. The noted discrepancy with previously reported decreasing calcification is likely due to the previously less realistic simulation of bicarbonate due to addition of acid or base to obtain simulated futur...

Elevated partial pressures of atmospheric carbon dioxide, similar to numerous causes of plant stress, may alter leaf pigmentation and structure and thus would be expected to alter leaf optical properties. Hypotheses that elevated CO(2) pressure and air temperature would alter leaf optical properties were tested for sugar maple (Acer saccharum) in the middle of its fourth growing season under tr...

A doubly substituted form of the nitrogenase MoFe protein (α-70(Val)(→Ala), α-195(His→Gln)) has the capacity to catalyze the reduction of carbon dioxide (CO(2)) to yield methane (CH(4)). Under optimized conditions, 1 nmol of the substituted MoFe protein catalyzes the formation of 21 nmol of CH(4) within 20 min. The catalytic rate depends on the partial pressure of CO(2) (or concentration of HCO...

The exchange rate of CO2 in artificial lungs depends on the sweep gas flow rate. Control of the amount of CO2 removed by an artificial lung requires quantitative knowledge of the flow dependence. A simple model of the dependence of CO2 exchange on sweep gas flow rate in artificial lungs has been previously presented (1). For a given partial pressure of CO2 in the blood phase, sweep gas flow rat...