Factors that affect PCO2 measurement in balloon saline during gastrointestinal tonometry are unclear. They include carbon dioxide diffusion rate, correction factors for calculation of equilibrium PCO2 from measurements at saline dwell times that are shorter than needed for full equilibration, role of blood-gas analyser bias during ex vivo PCO2 measurements in saline, and normal values for intra...

Because atmospheric carbon dioxide is the ultimate source of all land-plant carbon, workers have suggested that pCO2 level may exert control over the amount of C incorporated into plant tissues. However, experiments growing plants under elevated pCO2 in both chamber and field settings, as well as meta-analyses of ecological and agricultural data, have yielded a wide range of estimates for the e...

In view of the current increase in atmospheric pCO2 and concomitant changes in the marine environment, it is crucial to assess, understand, and predict future responses of ecologically relevant phytoplankton species. The diazotrophic cyanobacterium Trichodesmium erythraeum was found to respond strongly to elevated pCO2 by increasing growth, production rates, and N2 fixation. The magnitude of th...

The impacts of watercore on incidence of internal disorders and other physiological characteristics of ‘Fuji’ apples (Malus domestica Borkh) were determined following short-term exposure at 20 °C in 20 kPa CO2 (high pCO2) or long-term storage at 0.5 °C in 0.5 kPa O2+0.05 kPa CO2 (low pCO2) or 1.5 kPa O2+3 kPa CO2 (medium pCO2). CO2-injury (brown-heart) occurred in apples exposed to high pCO2 or...

Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy...

Seawater carbonate chemistry is typically calculated from two measured parameters. Depending on the choice of these input parameters, discrepancies in calculated pCO2 have been recognized by marine chemists, but the significance of this phenomenon for CO2 perturbation experiments has so far not been determined. To mimic different 5 pCO2 scenarios, two common perturbation methods for seawater ca...

Ocean acidification is a major threat to calcifying marine organisms such as deep-sea cold-water corals (CWCs), but related knowledge is scarce. The aragonite saturation threshold (Ωa) for calcification, respiration and organic matter fluxes were investigated experimentally in the Mediterranean Madrepora oculata Over 10 weeks, colonies were maintained under two feeding regimes (uptake of 36.75 ...

Because of limitations associated with commercial blood gas quality controls and tonometry of stored blood, fresh heparinized blood was used to compare PO2 and PCO2 performance of ten blood gas analyzers. Function of nine gas mixer/tonometer systems was evaluated. These were used to create blood samples with target values for PO2 and PCO2. All ten analyzers had high precision; this magnified sm...

This paper deals with statistical modelling of blood carbon dioxide partial pressure pCO2. The clinical measurements were carried out in the Arab Centre for Heart and Special Surgery in Amman. The statistical analysis of the results obtained demonstrates that pCO2 for arterial, venous and capillary blood have histograms approaching normal ones. Moreover, the experimental data suggest that the b...

We studied transcutaneous pCO2 monitoring in 70 neonates, most of them premature with respiratory distress syndrome. Measurements were at 44 degrees C. Calibration drift was large in some instances. Least squares linear regression analyses of transcutaneous pCO2 (y) vs arterial pCO2 (x) in kilopascals showed, for all observations (n = 516), for one observation randomly selected from each patien...