C-flux

Figure 2. The carbon dynamics of a primary forest prior to and following deforestation and slash burning. Arrows represent the relative magnitude of C flux. In the primary forest (represented by the large box at the top of the figure), the C pool is in a dynamic equilibrium with inputs approximately equalling exports. With deforestation and fire, the balance is altered with exports far exceeding imports.

J. N. Holland, W. Cheng, and D. A. Crossley, Jr, Herbivore-induced changes in plant carbon allocation assessment of below-ground C fluxes using carbon-14, Oe-cologia I07-.S1 (1996). 

C. Flux of ammonia through the urea cycle is regulated by two factors ... 

The coefficient Ln in Eq. 3.96 is positive and the equation therefore shows that the C flux will be in the direction of reduced C activity. Because the C activity is higher in the Si-containing alloy than in the non-Si-containing alloy at the same C concentration, the uphill diffusion into the non-Si-containing alloy occurs as observed. In essence, the C is pushed out of the ternary alloy by the presence of the essentially immobile Si. 

Figure 8. The high frequency nature of the vertical velocity (W), water vapor (q ), and CO2 densities (C ) at 2 meters above a soybean canopy during a 3 minute period. The illustration also shows instantaneous water vapor (W q ) and carbon dioxide (W C ) fluxes and the mean quantities for the 15 minute period from which these traces were taken. Data courtesy of Center for Agricultural Meteorology and Climatology, University of Nebraska, Lincoln, Nebraska, and Environmental Sciences Division, Lawrence Livermore National Laboratory, Livermore, California.

Fig. 2.1. Zero-current ion fluxes in the ion-selective membrane. Left (A) Concentrated inner solution induces coextraction of electrolyte into the membrane increasing the primary ion-ionophore concentration within the membrane. Consequently, primary ions leach into the sample increasing the activity of primary ions at the membrane/sample phase boundary. (B) Diluted inner solution and ion exchange at the inner solution side decreases the concentration of the complex within the membrane. Primary ions are siphoned-off from the sample, and their activity at the membrane/sample phase boundary is significantly decreased. (C) Ideal case of perfectly symmetric sample and inner solution resulting in no membrane fluxes. Note that fluxes of other species (counterions or interfering ions) are not shown for clarity. Right potential responses for each case. Ideal LOD is defined by the Nikolskii-Eisenman equation (Y Kj°jaj) and is obtained only in the ideal case (C). Fluxes in either direction significantly affect the LOD.

Despite its importance in ecosystem C fluxes, soil respiration has limitations as a constraint on SOM turnover, for two main reasons. First, it is difficult to partition soil respiration into its two sources (1) decomposition of SOM by microbes (heterotrophic respiration) and (2) respiration from live plant roots (autotrophic respiration) (Kuzyakov, 2006). As a result, an increase in soil respiration may indicate not only an increase in SOM decomposition but also an increase in root respiration. Second, it is likely that in most soils only a small fraction of total SOM contributes to heterotrophic respiration. As a result, respiration measurements provide information about the dynamic fraction of SOM (particularly when combined with 14C measurements of respiration) but do not provide information about the large, stable pools unless they are destabilized and contribute to respiration (detectable with 14C02 respiration measurements). Attributing the sources of respiration from different SOM reservoirs, which may respond differently to climatic variables, is not... 

C-flux With colonies (standard run) (figCL-1) No colonies... 

The daily C fluxes (pg C L-1 d-1 ) originate from an ecosystem model by Ruardij et al. (2005) and are averaged values over a period of 36 days. The standard run represents the situation as was observed during the mesocosm experiment, with both P. globosa single cells and colonies present. Viral lysis of phytoplankton is specific for P. globosa. Viral lysis of bacteria is a second order density-dependent mortality. Respiration and high refractory DOC were modeled but are not included in the table... 

Figure 4.10 Fits to kinetic data from [135] on the operation of citrate synthase from rat kidney. Data (flux as a function of substrate concentrations) were obtained from Figures 2, 3, 4, 5, 6, 7, and 9 of [135], Initial fluxes (p.mol of COASH (or CIT) synthesized per minute per ug of enzyme) measured at the substrate concentrations indicated are plotted in A, B, C, and D. For A, B, and D, the initial product (CIT and COASH) concentrations are zero. In C, flux was measured with COASH added in various concentrations to investigate the kinetics of product inhibition. E and F show fits to kinetic data on the reverse operation of kidney enzyme, with product concentrations indicated in the figure. All data were obtained at pH = 8.1 at 28 °C. Model fits in all cases are plotted as solid lines.

Figure 4.12 Analysis of data from Smith and Williamson [188] on inhibition of cardiac enzyme. Measured flux in arbitrary units was obtained from Figures 1 and 2 of [188], A. Flux is plotted as a function inhibitor ATP concentration for [ACCOA]= 16 pM and OAA = 1.13 and 2.25 pM. B. Flux is pi oiled as a function of [ACCOA] at [OAA] = 5 pM at three different concentrations of ATP indicated in figure. C. Flux is plotted as a function of [ACCOA] at [OAA] = 3.1 pM at three different concentrations of SCOA indicated in figure. All data were obtained at pH = 7.4 at 21 °C. Model fits are plotted as solid lines.

As mentioned in the introduction, one goal of some experiments was to examine, to which extent the chemical erosion of doped materials is reduced. For example, the methane formation by plasma exposure of NS31 (Si-doped CFC with 1.0-1.5% Si) was reduced by a factor of two in comparison to graphite. The interpretation of this result (as of others, e.g., C flux from W) is very complex. We have to be aware that the measurements were done in a carbon machine and we have to take into account the carbon fluxes onto... 

Using small signal theory, we find that the fluxes and concentrations can be written in the form f = ] + J eiat, nB = hs + hseiat where Jf is the d.c. flux... 

A % land area B % weath. flux C %flux to ocean... 

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