Context. Previous research has indicated that high amounts of ozone (O3) and oxygen (O2) may be produced abiotically in atmospheres with high concentrations of CO2. The abiotic production of these two gases, which are also characteristic of photosynthetic life processes, could pose a potential “false-positive” for remote-sensing detection of life on planets around other stars. We show here that...

Homeostasis of internal carbon dioxide (CO2) and oxygen (O2) levels is fundamental to all animals. Here we examine the CO2 response of the nematode Caenorhabditis elegans. This species inhabits rotting material, which typically has a broad CO2 concentration range. We show that well fed C. elegans avoid CO2 levels above 0.5%. Animals can respond to both absolute CO2 concentrations and changes in...

Salad savoy (Brassica oleracea L.) is a vegetable crop that is becoming a valued addition to fresh-cut salad mixes. This study was conducted to develop a modified atmosphere packaging system for fresh-cut salad savoy and to evaluate the effect of film oxygen transmission rate (OTR) on package atmospheres, and consequently product quality changes during storage. Two varieties of salad savoy (whi...

BACKGROUND: CO2-pneumoperitoneum used in endoscopic surgery induces system effects by CO2 absorption. This study investigated the effect of the addition of O2 to CO2-pneumoperitoneum, upon CO2 absorption. METHODS: The effect of a pneumoperitoneum using 100% CO2 or 94% CO2 6% O2 upon arterial blood gases, acid base and O2 homeostasis was evaluated. In series A suboptimal ventilation and a pneumo...

Wetland plants actively provide oxygen for aerobic processes in submerged tissues and the rhizosphere. The novel concomitant assessment of diurnal dynamics of oxygen and carbon dioxide concentrations under field conditions tests the whole-system interactions in plant-internal gas exchange and regulation. Oxygen concentrations ([O2]) were monitored in-situ in central culm and rhizome pith caviti...

BACKGROUND Exposure to carbon dioxide (CO2) gas as a killing method is aversive and exposure to high concentrations is likely to be painful. Bradycardia during exposure to CO2 is associated with nociception and pain. However, it is unclear if bradycardia occurs before loss of consciousness as definitions of loss of consciousness vary in the literature. The objectives of this study were to explo...

This paper evaluates the influence of the main constituents of flue gases from coal combustion (CO2, O2, N2 and water vapor), in air and oxy-fuel combustion conditions on the re-emission of Hg(0) in wet scrubbers. It was observed that the concentration of water vapor does not affect the re-emission of mercury, whereas O2 and CO2 have a notable influence. High concentrations of O2 in the flue ga...

Modeling and optimization of synthesis gas production via the non-catalytic partial oxidation of methane (NCPO) were studied by minimizing of Gibbs free energy, and comparison studies were carried out to analyze the mechanism of syngas production. For this purpose, concentrations of CO2 and H2O in the feed were optimized in specified pressure and temperature, such that the hydrogen to carbon mo...