Fitting peak

Using the data from Fig. 19-11, the calculated cr from the CWI concentration is 239 m from the observed peak concentration it is 232 m and from the fitted peak concentration it is 235 m. Note that errors in any ofthe parameters H, Q, or u, will cause errors in the estimated [Pg.314]

Cell cycle analysis by dedicate software (e g. Modfit or Flowjo ) [26] usually underestimates percentage of cells in S-phase, since Gi and G2/M peaks are fitted by a gaussian model with modelling of cell cycle phases, and early (ES) and late S-phase (LS) are included inside fitted peaks (Figure 4). 

Figure 2.12 shows the Cp values resulting from fitting peak potentials measured in CV as a function of ionic strength with Equation 2.5 for PAH-Os/PVS films finished either in positive or negative polyions and assembled and tested at different pHs. Interestingly, not always do films finished in PVS have Cp < 0 and films capped with PAH-Os have Cp>0, which means that uncompensated charges at the electrolyte/ film interface are not the only contribution to Cp. The other contribution arises from... 

Weinreich, D. M. and Chao, L. 2005. Rapid evolutionary escape by large populations from local fitness peaks is likely in nature. Evolution, 59 1175-1182. 

Random energy model The random energy model (REM) results from using a fitness distribution p(f) to assign fitnesses randomly to points in the landscape [ 14,59,60,70,71,81, 91,92], p(f) is the probability that a point in the sequence space has fitness fand is exactly analogous to affinity distribution p(Ka). Such landscapes have zero correlation (are very rugged), have many local fitness peaks, and result in very short adaptive walks. Very few of the local peaks are accessible by adaptive walks from any particular point. 

Fig. 4. The role of neutral networks in evolutionary optimization through adaptive walks and random drift. Adaptive walks allow to choose the next step arbitrarily from all directions where fitness is (locally) nondecreasing. Populations can bridge over narrow valleys with widths of a few point mutations. In the absence of selective neutrality (upper part) they are, however, unable to span larger Hamming distances and thus will approach only the next major fitness peak. Populations on rugged landscapes with extended neutral networks evolve along the network by a combination of adaptive walks and random drift at constant fitness (lower part). In this manner, populations bridge over large valleys and may eventually reach the global maximum ofthe fitness landscape.

Fig. 1. A two-dimensional projection of the hyperdimensional fitness landscape. In this simplified representation, sequence space is shown for a 4-mer where the colors represent amino acid types. The all-blue sequence is the global optimum the lower fitness peaks are local optima. The problem of in vitro evolution is how to search this space effectively, without becoming trapped at a suboptimal fitness.

To discover new fitness peaks, the neutral network must be sufficiently extended, allowing neutral drift to effectively sample sequence space. A neutral network can be characterized by a mean fraction of neutral neighbors A (Reidys et al., 1997). If A exceeds a threshold A,., then the network is connected and dense, making it more likely the network percolates through sequence space. If A < Ac, the networks are partitioned into components. Using random graph theory, the threshold is derived analytically as... 

Mohwald and co-workers conducted similar research on arachidic acid monolayer on the subphase of different pHs in the presence of sodium ions [93]. The fitted peak intensities are related to surface concentrations of single and double hydrogen bonded and non-hydrogen bonded carbonyl and carboxylate. From the change of the concentrations with the pH, tentative conclusions are drawn on the bonding situation of fatty acids in monolayers on water and alkaline solution. 

Fig. 11.9. The 500 eV noncoplanar-symmetric valence energy spectra for xenon at 0 = 0° and 10° (Cook et al, 1986). The full curve is obtained by fitting peaks (broken curves) of the known experimental resolution function at known energy levels of Xe" ". From McCarthy and Weigold (1991).

Bortels, G. and Collaers, P.J., Analytical functions for fitting peaks in alpha-particle spectra. Int. J. Appl. Radiat. Isotop., 38 (1987) 831. 

Figure. 44 shows the C Is (a-d), O Is (e-h), and Fe 2p 2 (i-j) XPS peaks of CWZ (NM and Ox) samples with adsorbed iron ions. There were marked differences between the experimental (dotted) and synthesized (continuous) lines in all the spectra. The position of deconvoluted peaks (dashed lines) were determined according to both literature data [188,191,240-247] and empirically derived values. The relative areas (%) of the fitted peaks were also calculated. Several peaks attributable to carbon, oxygen, nitrogen, and iron were present. The XP survey spectra of the initial modified carbons (before adsorption) were discussed... 

Figure 4.6. Observed and simulated spectra of the synthetic aluminosilicate mineral pink ultramarine, including fitted peaks, showing resolution of all possible Si(nAl) units. From Klinowski et al. (1987), by permission of MacMillan Magazines Ltd.

Figure 9.5. H MAS NMR spectra of hydrous silica glasses with different water contents. D is the simulation of spectrum C showing 4 separate proton resonances. Fitted peaks a and c are thought to be due to Si-OH groups in 2 different environments while peaks b and d are due to molecular water in 2 different environments. From Kohn et al. (1989), by permission of the copyright owner.

Figure 9.23. A. N NMR spectra of polyborazilene precursor for the production of BN. Upper solid state MAS spectrum, middle solid-state CP MAS spectrum, lower liquid-state spectrum in tetrahydrofuran. B. Schematic representations and calculated N chemical shifts of the various environments in hexagonal BN. C. Observed and simulated N MAS NMR spectrum of polyborazilene showing the fitted components with assignments according to the environments of Figure 9.23B. The fitted peaks from the BHN2 sites are shown by full lines, those from BN3 sites by broken lines. From Gervais et al. (2001), by permission of the American Chemical Society.

Figure 5. Normalized -weighted As-EXAFS spectra (a) and Fourier transforms (FTs) (b) of As(V) sorption on goethite (total reaction time = 1032 hours) after I hour and 24 hours desorption ofAs(V) by 6 mM phosphate. The spectrum ofscorodite is plotted for comparison. Solid lines are experimental data dotted lines are least-squares fits. Peak positions in FTs are not corrected for phase-shift effects, and are therefore approximately 0.5 A shorter than the true distance. Reprinted from O Reilly et al. (2001) with permission.

By stepping a over the duration of the pulse and collecting a pump-probe spectrum for each time value of a, the vibrational population transfer over the course of the pulse is assessed. To quantitatively extract relative vibrational populations from these pump-probe spectra, we fit peak intensities assuming a harmonic scaling law for the transition dipoles [e.g., (n + l) /xn n+i 2 = (n + 2)... 

Figure 3. High energy region of the (J.XRF spectrum for a 3 pm interplanetary dust particle showing peaks due to trace elements at the 10 ag level. Shown are the raw spectrum, background fit, individual fitted peaks (labeled) and the overall fitted spectrum. The fluorescence spectra for elements with atomic number near 40 are complicated by the overlap between the peak of element Z and the Kp peak of element Z-2. The odd-even abundance effect in the chondritic (solar) composition is apparent. Krypton derives from air in the analysis environment.

Fitness Landscapes and Effective Means of Conquering Fitness Peaks... 

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