Excess signal

The preceding sections have established that the U-series information from arc lavas is a complex end-product of several different processes and this is especially true for U-Th isotopes. The two observations that seem to be most robust are (1) the need to transfer the Ra-excess signal from the subducting plate into the melting zone and to the surface in less than a few 1000 years, and (2) the need for a partial melting process which allows for Pa in-growth. There are a number of different models which can take account of these two requirements but which have different implications for the U-Th isotope arrays. 

When high-resolution NMR spectra have to be recorded of a polymeric sample, one has to recognize that polymer solutions are in general highly viscous. To prevent excessive signal broadening caused by this restricted mobility of the solution, polymer solutions for NMR studies have to be highly diluted (approx. 

The activity of the cytokine receptors is under tight control to avoid prolonged activation and excessive signaling. Several mechanims exist by which termination and damping of cytokine receptor signaling is achieved ... 

Fig. 10.4. Illustration of excess signals and their subtraction in typical small angle x-ray scattering experiment. The filled squares and open circles are SANS spectra of

Table II, in these mutants, but not in the leu mutants, the isoleucine-vafine biosynthetic enzymes were also derepressed. At that time, however, it was already known that the repression of these enzymes is multivalent, that is, the enzymes are repressed only if isoleucine, valine, and leucine are in excess [16]. Thus, it was clear that the leu S function needed in generating the leucine excess signal for repression of the...

Figure 3 shows the microwave excess signal loss through 6 inch thick AZS for a reflection from the inner surface. Note the 28 dB RF loss (round trip reflection) due to the high temperature at... 

The signal transduction from outside the cell to the nucleus depends on several proteins (kinase enzymes and ras proteins). Signal transduction is a normal process needed by healthy cells, but in cancer cells excessive signal transduction favors proliferation and metastasis. So cancer can be inhibited by normalizing signal transduction. 

The hydroxyl signals are of no significance because of excessive signal broadening. Other regions of the spectrum are nearly identical to those of humulone. Upon comparison of both spectra with the spectrum of dihydrohumulone, the structure... 

The two sections of the multiplier are separated by a special gate electrode. In the presence of very high signal levels, the gate electrode can be activated to gate off the pulse-counting part of the detector to protect it from excessive signal levels and thus extend its operational life. 

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