Greater understanding of the pathophysiology of carbon dioxide kinetics during steady and nonsteady state should improve, we believe, clinical care during intensive care treatment. Capnography and the measurement of end-tidal partial pressure of carbon dioxide (PETCO2) will gradually be augmented by relatively new measurement methodology, including the volume of carbon dioxide exhaled per breat...

BACKGROUND We aimed to compare plasma concentrations of carbon dioxide (CO(2)) in dogs that underwent intra- and preperitoneal CO(2) insufflation. MATERIALS AND METHODS Thirty dogs were studied. Ten formed a control group, 10 underwent intraperitoneal CO(2) insufflation, and 10 underwent preperitoneal CO(2) insufflation. General anesthesia with controlled ventilation was standardized for all ...

Elevated CO2, in the dark, is sometimes reported to inhibit leaf respiration, with respiration usually measured as CO2 efflux. Oxygen uptake may be a better gauge of respiration because non-respiratory processes can affect dark CO2 efflux in elevated CO2. Two methods of quantifying O2 uptake indicated that leaf respiration was unaffected by coincident CO2 level in the dark.

Iglesias-Rodriguez et al. (Research Articles, 18 April 2008, p. 336) reported that the coccolithophore Emiliania huxleyi doubles its organic matter production and calcification in response to high carbon dioxide partial pressures, contrary to previous laboratory and field studies. We argue that shortcomings in their experimental protocol compromise the interpretation of their data and the resul...

[1] Global ocean carbon models and available syntheses of the oceanic CO2 flux suggest that the North Atlantic subpolar gyre (50 N–70 N, 80 W–10 W) is a region of increasing uptake of CO2 from the atmosphere, with the oceanic partial pressure of CO2 (pCO2) increasing more slowly than the atmospheric CO2 over time. Our analysis of available CO2 data shows that, on the contrary, seawater pCO2 has...

Freshwater systems are at risk owing to increasing carbon dioxide (CO2) levels, and one of the possible reasons for these elevations is the deployment of non-physical fish barriers to prevent invasive fish movements. Carbon dioxide barriers have the potential to create short, chronic and intermittent exposures of CO2 for surrounding freshwater biota. Although intermittent exposures to a stresso...

Natural and human-induced controls on carbon dioxide (CO(2)) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication b...

In response to the massive volume of water along the Amazon River, the Amazon tributaries have their water backed up by 100s of kilometers upstream their mouth. This backwater effect is part of the complex hydrodynamics of Amazonian surface waters, which in turn drives the variation in concentrations of organic matter and nutrients, and also regulates planktonic communities such as viruses and ...

Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat....