assay of Keilin and Hartree (Biochem. J. (London), 42, 230, 1948) was used to measure initial and residual sugar in the carbon balance studies. Total carbon was determined by the wet carbon oxidation method (Van Slyke et al., J. Biol. Chem., 191, 299, 1951), and carbon assimilation into polysaccharide and cellular material was estimated from wet carbon oxidation of the culture samples after dia...

BACKGROUND The American Thoracic Society recommends that the inspired concentration used for the estimation of carbon monoxide transfer factor (TLCO) mixture should be 0.25-0.35% carbon monoxide, 10-14% helium, 17-21% oxygen, balance nitrogen. Inspired oxygen influences alveolar oxygen and hence carbon monoxide uptake, such that transfer factor increases by 0.35% per mm Hg decrease in alveolar ...

The continuous flow of carbon from the land and water through the atmosphere and living organisms makes up the global carbon cycle [1]. It contains reservoirs where carbon is stored and features dynamic flows of carbon between the carbon pools [2]. Forests are one of the largest reservoirs of carbon on Earth [1], and therefore their storage and release of carbon have a great impact on the globa...

BACKGROUND Carbon storage potential has become an important consideration for land management and planning in the United States. The ability to assess ecosystem carbon balance can help land managers understand the benefits and tradeoffs between different management strategies. This paper demonstrates an application of the Land Use and Carbon Scenario Simulator (LUCAS) model developed for local-...

BACKGROUND Disturbance is a key influence on forest carbon dynamics, but the complexity of spatial and temporal patterns in forest disturbance makes it difficult to quantify their impacts on carbon flux over broad spatial domains. Here we used a time series of Landsat remote sensing images and a climate-driven carbon cycle process model to evaluate carbon fluxes at the ecoregion scale in wester...

BACKGROUND Managed forests are a major component of tropical landscapes. Production forests as designated by national forest services cover up to 400 million ha, i.e. half of the forested area in the humid tropics. Forest management thus plays a major role in the global carbon budget, but with a lack of unified method to estimate carbon fluxes from tropical managed forests. In this study we pro...

This study estimates the complete carbon budget of an 11.4 km(2) peat-covered catchment in Northern England. The budget considers both fluvial and gaseous carbon fluxes and includes estimates of particulate organic carbon (POC); dissolved organic carbon (DOC); excess dissolved CO(2); release of methane (CH(4)); net ecosystem respiration of CO(2); and uptake of CO(2) by primary productivity. All...

Complex interactions among climate change and ecosystem processes (plant demographics, tree-grass interactions, grazers, browsers, fire and nitrogen) challenge our ability to predict future carbon stocks in Africa and other tropical regions. Recent work suggests Africa has a near zero decade-scale carbon balance, but that climate fluctuations induce sizeable variability in ecosystem productivit...