[1] On the basis of a broad compilation of data on pCO2 in surface waters, we show tropical lakes to be, on average, far more supersaturated and variable in CO2 (geometric mean ± SE pCO2 = 1804 ± 35 matm) than temperate lakes (1070 ± 6 matm). There was a significant negative relationship between pCO2 and latitude, resulting in an average decrease of pCO2 by 2.8 ± 0.5% per degree latitude. In ad...

Species distributions and ecology can often be explained by their physiological sensitivity to environmental conditions. Whilst we have a relatively good understanding of how these are shaped by temperature, for other emerging drivers, such as PCO2  we know relatively little. The marine polychaete Sabella spallanzanii increases its metabolic rate when exposed to high PCO2  conditions and remain...

Seaweeds that lack carbon-concentrating mechanisms are potentially inorganic carbon-limited under current air equilibrium conditions. To estimate effects of increased atmospheric carbon dioxide concentration and ocean acidification on photosynthetic rates, we modeled rates of photosynthesis in response to pCO2, temperature, and their interaction under limiting and saturating photon flux densiti...

Cammarata, Gianluca A. A. M., Max Harry Weil, Michael Fries, Wanchun Tang, Shijie Sun, and Carlos J. Castillo. Buccal capnometry to guide management of massive blood loss. J Appl Physiol 100: 304–306, 2006. First published September 1, 2005; doi:10.1152/japplphysiol.01247.2004.—In both clinical and experimental settings, tissue PCO2 measured in the oral mucosa is a practical and reliable measur...

The purpose of this study was to find the dominant processes affecting the diel carbon cycle of the Biosphere 2 ocean from July 27, 1995 to August 14, 1995. Despite excessively low nitrate (B0.05 mmol l) and phosphate (0.00–0.04 mmol l) values, the Biosphere 2 ocean not only showed large daily TCO2 changes of 30.597.0 mmol kg but also a net production of organic carbon and CaCO3 during the peri...

Recent work has shown that the behaviour of marine organisms can be affected by elevated PCO2 , although little is known about the effect of multiple stressors. We therefore investigated the effect of elevated PCO2  and temperature on locomotion and behaviour during prey searching in the marine gastropod Concholepas concholepas, a predator characteristic of the southeastern Pacific coast. Movem...

Antarctic ice cores document glacial-interglacial and millennial-scale variability in atmospheric pCO2 over the past 800 kyr. The ocean, as the largest active carbon reservoir on this timescale, is thought to have played a dominant role in these pCO2 fluctuations, but it remains unclear how and where in the ocean CO2 was stored during glaciations and released during (de)glacial millennial-scale...

The relation between the partial pressure of atmospheric carbon dioxide (pCO2) and Paleogene climate is poorly resolved. We used stable carbon isotopic values of di-unsaturated alkenones extracted from deep sea cores to reconstruct pCO2 from the middle Eocene to the late Oligocene (approximately 45 to 25 million years ago). Our results demonstrate that pCO2 ranged between 1000 to 1500 parts per...

Monitoring splanchnic perfusion by means of gastric intramucosal tonometry is carried out using saline, or more recently, air tonometry using the Tonocap. The objective of this study was the validation of the Tonocap in saline and perfluorocarbon FC 43. The two methods underestimated the predefined PCO2 value by an average of 10%, with clinically acceptable precision. Accuracy of the Tonocap im...

The objective of this study was to examine the repeatability of blood gas (BG) parameters and their derived variables such as the central venous-to-arterial carbon dioxide tension difference (▵PCO2) and the ratio of ▵PCO2 over the central arteriovenous oxygen content difference (▵PCO2/C(a-cv)O2) and to determine the smallest detectable changes in individual patients.A total of 192 patients with...