Fluctuation analysis

Selected entries from Methods in Enzymology [vol, page(s)] Analysis, software for, 207, 717 barrier models, 207, 818 closed and open time estimation, 207, 755 data acquisition, 207, 747 modal behavior analysis, 207, 757 multiple channel problem, 207, 756 single-channel [extraction of kinetic information, 207, 765 measurement in tissue slices, 207, 220] synaptic, resolution improvement in patch clamp recording, 207, 216 whole-cell recording in calcium channel, 207, 181 fluctuation analysis, 207, 192. 

Study RE, Barker JL Diazepam and pentobarbital fluctuation analysis reveals different mechanisms for potentiation of gabaaminobutyric acid responses in cultured central neurons. Proc Natl Acad Sci U S A 78 7180-7184, 1981... 

Around 1970, some clues as to individual channel action emerged. Katz and Miledi (1972) discovered that the end-plate membrane potential becomes markedly noisy in the presence of acetylcholine, and they interpreted this as a series of elementary events produced by the opening and closing of individual channels as they bound and released acetylcholine molecules. This led to a series of studies by Stevens and others using techniques of fluctuation analysis to gain information about the size and duration of these events. 

Wavelet techniques (Koscielny-Bunde et al., 1998) and detrended fluctuation analysis (DFA) (Peng et al., 1994) are among the most recently used tools along these lines. Recently, much attention has been paid to DFA, because it has already proved its usefulness in a wide variety of complex systems (e.g., Stanley, 1999 Talkner and Weber, 2000 Varotsos et al., 2003a, b, 2005 Chen et al., 2005 Varotsos and Kirk-Davidoff, 2006). More information about the DFA method is given in Section 3.6.3.2. 

Chen Z. Hu K. Carpena P. Bernaola-Galvan P. Stanley H.E. and Ivanov P. (2005). Effect of nonlinearities on detrended fluctuation analysis. Physical Review, E71, art. no. 011104. 

Kantelhardt J.W. Zschiegner S.A. Koscielny-Bunde E. Havlin S. Bunde A. and Stanley H.E. (2002). Multifractal detrended fluctuation analysis of nonstationary time series. Physica, A316(14), 87-114. 

Talkner P. and Weber R.O. (2000). Power spectrum and detrended fluctuation analysis Application to daily temperatures. Physical Review, Part A, E62(l), 150-160. 

Taylor and Girault [154], and has been further developed by Girault and coworkers [155], Vanysek and Hernandez [156] and Mare k et al. [149]. The use of a microscopic interface is an essential requirement for a fluctuation analysis of ion transfer system under thermodynamic equilibrium which was attempted first by Marecek et al. [149]. No kinetic data have been reported from voltammetric or noise measurement at microliquid interfaces, though a new insight into the interfacial dynamics comprising ion transfer has been thought possible [149]. 

Besides improving classical electrochemical methods, newly employed techniques such as second harmonic-generation and time-resolved fluorometry, with either control of the potential drop across the interface or fluctuation analysis, are promising in this respect. Also indispensable are further advances in molecular dynamics and statistical-mechanical treatments of structure and charge transfer at the ITIES. 

Debenedetti P. Clustering in dilute, binary supercritical mixtures A fluctuation analysis. Chem. Eng. Sci. 1987 42(9) 2203-2212. 

It is, when possible, very convenient to be able to treat the kinetics of the chemical reaction separately from the translational diffusion in the fluctuation analysis. As mentioned, a rather broad range of chemical reactions fulfills the criteria for (8.3)-(8.5). In addition, for a reaction which under standard conditions does not fulfill these criteria, it is sometimes possible to modify the conditions. For instance, the dwell times can be retarded with respect to the chemical relaxation times by expanding the observation volume or by speeding up the reactions under study, for instance by using higher concentrations of unlabelled reactants. 

One limitation, however, is that only a limited number of spots can be measured simultaneously. A compromise between the temporal analysis of FCS and fluorescence fluctuation analysis in the spatial domain [39] can be obtained by exploiting the time structure of sample/laser scanning confocal microscope images [40,41]. Thereby, spatial correlation analysis of the emitted fluorescence is combined with temporal characterization of the fluorescence emission from the serial data stream of subsequently scanned pixels. This... 

There have been a number of modeling efforts that employ the concept of clustering in supercritical fluid solutions. Debenedetti (22) has used a fluctuation analysis to estimate what might be described as a cluster size or aggregation number from the solute infinite dilution partial molar volumes. These calculations indicate the possible formation of very large clusters in the region of highest solvent compressibility, which is near the critical point. Recently, Lee and coworkers have calculated pair correlation functions of solutes in supercritical fluid solutions ( ). Their results are also consistent with the cluster theory. 

In contrast to Mutascreen, the AmesII assay utilizes fluctuation analysis for calculation of reversion frequency. Besides the standard Salmonella tester strain TA98, the AmesII assay also includes new strains each designed to revert by only one specific base pair substitution mutation.13 Thus, when mixed, all six base pair substitutions can be represented in one culture. 

Table 4 Characterization of the active site structure and fluctuations. Analysis was performed over the last 25 ns (10 ps sampling)... 

Merlitz H, Herges T, Wenzel W (2004) Fluctuation analysis and accuracy of a large-scale in silico screen. J Comput Chem 25(13) 1568-1575... 

Recently, deep ROSAT pointed observations (Hasinger et al. 1993) have shown that a substantial fraction (about 60%) of the background in the 1-2 keV band can be resolved into discrete sources at a flux level of about 3 X 10 ery/cm 5. A fluctuation analysis of the remaining background is consistent with all the soft background being due to discrete objects, and restricts a possible diffuse process to less than 25%. 

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