Current fluctuation spectra

Potassium current fluctuation spectra in frog nodes (19) yield Yjr=2.9 pS in close agreement with the value obtained from single variance measurements (10). Table 1 summarizes estimates of y and obtained from fluctuation analysis. 

Very recently, more reliable sodium current fluctuation spectra... 

Raman parent spectrum is obtained simply by adding all the spectra together. However, the ROA spectrum is obtained by either adding or subtracting from the current coadded spectrum depending on the position of quarter-wave plate. After several cycles, the Raman and ROA spectra are saved on the hard disk as one data set. After several data sets, all the data are added and saved into either the Raman parent spectrum or the ROA raw data spectrum and stored for the data manipulation. Occasionally, the raw data contains parental bias or first derivative contributions due to the fluctuation of the laser intensity or the quality of the optics, and these are reduced or removed digitally. 

More details of the large scale distribution of galaxies as the full SDSS data set becomes available. Already it and 2dF seem to connect up the current power spectrum of density fluctuations vs. length scale very nicely with the CMB numbers. 

If further observational and associated theoretical work should confirm the current tension among the SBBN-predicted and observed primordial abundances of D, 4He, 7Li, what physics beyond the standard models of cosmology and particle physics has the potential to resolve the apparent conflicts Are those models which modify the early, radiation-dominated universe expansion rate consistent with observations of the CMB temperature fluctuation spectrum If neutrino degeneracy is invoked, is it consistent with the neutrino properties (masses and mixing angles) inferred from laboratory experiments as well as the solar and cosmic ray neutrino oscallation data ... 

From the above equation it follows that the surface salinity of the Baltic Sea is controlled by the ratio between the freshwater surplus and the sum of the stochastic salt fluxes normalized by the salinity difference between the Kattegat and the Arkona Sea surface water, see Fig. 2.6. The turbulent salt diffusivity k is a function of the geometry of the Belt Sea in terms of the length of the channel and the sill depth as well as of the spectrum of wind fluctuations determining the sea level difference between the Kattegat and the Arkona Sea and subsequently the barotropic current fluctuations in the Belt Sea. 

An alternative approach is to impose random fluctuations upon the flow and then use Fourier analysis of the resultant current or potential fluctuations to obtain the transfer function. MartemYanov and Grafov [17, 87, 88] used a particularly simple method employing a paddle stirrer to generate a turbulent flow, with a uniform spectrum of fluctuations over the frequency range (<100 Hz). This methodology was termed hydroelec-... 

After water vapor and C02, methane (CH4) is the third most important greenhouse gas. Each additional molecule of CH4 added to the atmosphere absorbs about 20 times as much long-wave infrared radiation as does a molecule of carbon dioxide. This occurs in part because some of the absorption spectrum of methane lies in windows in the carbon dioxide absorption spectrum (see Fig. 4-42) therefore, methane absorbs wavelengths that are not already being highly attenuated by carbon dioxide. Currently, the global concentration of methane in the atmosphere is approximately 1.7 ppm and is increasing at an annual rate of approximately 0.01 ppm per year (Table 4-14). The seasonal fluctuations shown in Fig. 4-44 may correspond to seasonal... 

Fluctuations in spectral intensities8-14 provide an even more detailed probe. Transition rates examine only the variation with the initial state (all final states being usually summed over). A spectrum can be studied for the distribution of intensities over all final states and, moreover, the initial state can be varied. The measurement of spectra at the required resolution for the excitation range of interest is not easy, but improved and novel techniques15,16 are currently providing a wealth of data. 

A model membrane system that also shows reproducible and clear 1/f behavior was described by Bezrukov and Brutyan (76). Fluctuations of current through lipid bilayers with one-sided application of three different polyene antibiotics of very close chemical structure (i.e., amphotericin B, nystatin, and mycoheptin) were studied. For one-sided application these antibiotics form channels that are weakly bound to the membrane as compared with the channels of the two-sided action. All three compounds produced pronounced noise component with spectral distribution of 1/f type (Figure 8). It was found that the noise intensity scales as the ratio of single channel conductances for amphotericin B, nystatin, and mycoheptin namely, hA hN hM = 10 5 1. For mycoheptin the spectrum is described by the function 1/f0-86 over the whole frequency range used. With two-sided application of these antibiotics, channels are more stable and strongly bound to the bilayer. In this case, significantly lower noise intensities were found the spectrum for amphotericin B was described by a single Lorentzian spectrum of relatively small amplitude (63). 

Note that at fixed current values the voltage fluctuations are substantially equivalent to conductance fluctuations. For potassium channels similar measurements showed that the potassium conductance spectrum can be represented as a sum of the flicker and Lorentzian conponents. However, the fcidifferent systems and techniques involved. 

---