Independent sequential analyses

Independent sequential analyses. In order to explain the basis of an MS/MS experiment consider the basic reaction sequence shown in reaction 1. 

The most common approach to in vivo pharmacokinetic and pharmacodynamic modeling involves sequential analysis of the concentration versus time and effect versus time data, such that the kinetic model provides an independent variable, such as concentration, driving the dynamics. Only in limited situations could it be anticipated that the effect influences the kinetics, for example effects on blood flow or drug clearance itself. 

Fast atom boinbardment mass spectrometry (FAB-MS), being able to detect the masses of the individual molecules in a mixture of homologues, is particularly suitable for the detection of a series of oligomers in copolymer samples. The assumption on which the sequential analysis of a copolymer by mass spectrometry is based is that ions detected in FAB-mass spectra originate from species already present in the polymeric sample. Furthermore if FAB ionization produces the fragmentation of macromolecules, it is assumed that this is independent of chain length. ... 

FT-MIR, Fourier transform mid-infrared spectroscopy 2D-CoS, two-dimensional correlation spectroscopy 3D-FF fluorescence spectroscopy, 3D-font-face fluorescence spectroscopy ICA, independent component analysis SIA, sequential injection analysis EEM, excitation and emission matrices. V ... 

Reduce complexity and design modular systems As far as possible, use proven techniques and combine them in new ways, but let them be independent from each other, e.g., allow different synthesis methods that are independent from your reactor configuration. Furthermore, allow different sequential or parallel analysis methods. This is not a contradiction to the aforementioned integration because workflow integration does not necessarily mean technology integration. 

Deconvolution Analysis of DSC. Data analysis was carried out using the DECONV section of the DA-2 software package. This software, which is based on the deconvolution procedure of Freire and Biltonen (4), allows deconvolution of differential heat-capacity peaks either as the result of simple addition of multiple independent transitions or as the result of more complex mathematical processes representing the combination of transitions that interact in such a way that an obligatory reaction sequence is imposed (sequential transitions). 

This classification technique uses a space that is defined by a unique set of vectors called linear discriminants or LDs. Like the PCs obtained from PCA analysis, LDs are linear combinations of the original M-variables in the X-data that are completely independent of (or orthogonal to) one another. However, the criterion for determining LDs is quite different than the criterion for determining PCs each LD is sequentially determined such... 

Independent parameters with a simple effect on the resolution may be optimized sequentially, i.e. one after the other (section 5.1.1). Hence, after the selectivity has been optimized, the shortest possible column length or the highest possible flowrate may be established that will provide sufficient resolution. Adapting the length of the column is the preferred strategy, because it will lead to both faster analysis and lower pressure drops. 

Sequential measurement of impedance by Fourier analysis provides good accuracy for stationary systems. The sequence of ftequencies can be arbitrarily selected, and therefore frequency intervals of A///, considered to be the most economical use of frequencies, can be employed. Because the measurements at each frequency are independent of each other, frequencies foimd to be inconsistent with the Kramers-Kronig relations can be deleted. 

The amount of EBT present in Showa Denko tryptophan varied markedly in the period 1987-89 (Figure 5), presumably reflecting alterations in the manufacturing conditions. It is likely that levels of all of the contaminants varied with time. These data are consistent with the hypothesis that a contami-nant(s) in tryptophan is responsible for EMS and for the sporadic cases of EE between 1986 and 1988. Recent statistical analyses of EBT, adjusted for serial autocorrelation (to take into account that sequential lots of tryptophan may be related), revealed that higher levels of EBT are still associated with EMS, but the association (p = 0.120) did not achieve statistical significance. Nonetheless, the results do not vindicate EBT as a cause of EMS because mis-classification of lots as case or control could weaken the association and the methods used to account for the lack of independence of observations over time probably reduce the power of the statistical analysis. 

Justification of the choice of independent variables. All reasonable parameters must be validated by an appropriate statistical procedure (e.g., by stepwise regression analysis). The best equation is normally the one with the lowest standard deviation, all terms being significant (indicated by the 95% confidence intervals or by a sequential F test). Alternatively, the equation with the highest overall F value may be selected as the best model (nowadays crossvalidation and/or F-scrambling are recommended as validation tools). 

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