Experimental robustness

Data analysis and sensibly applied statistical tools are of crucial importance for metabolomics. Good experimental design is of course a fundamental first requirement. There have been a number of books and research papers written recently discussing statistics use and models for data analysis of metabolomics.100-104 Statistical and experimental robustness have been the focus of metabolomics and demonstrated in a study of NMR protocols and multivariate statistical batch processing, which were examined for consistency over six different centers. The data were shown to be sufficiently robust to generate comparable results across each center.105... 

Correlating coupled heteronuclear spins across a single bond and hence identifying directly connected nuclei, most often Employs detection of high-sensitivity nuclide e.g. H, F, (an inverse technique ). Experimentally robust sequence, well suited to routine structural characterisation. 

Despite the progress made in the field in the last three decades there is currently no single reliable, rapid and experimentally robust method for the forensic identification and discrimination of complex, chemically similar silicone elastomers. There are, however, non-spectroscopic methods available that may be developed to serve such a function. 

C. Daniel, App/ications of Statistics to lndustria/Experimentation, ]oE Wiley Sons, Inc., New York, 1976. This book is based on the personal experiences and insights of the author, an eminent practitioner of industrial appHcations of experimental design. It provides extensive discussions and concepts, especially in the areas of factorial and fractional factorial designs. "The book should be of use to experimenters who have some knowledge of elementary statistics and to statisticians who want simple explanations, detailed examples, and a documentation of the variety of outcomes that may be encountered." Some of the unusual features are chapters on "Sequences of fractional repHcates" and "Trend-robust plans," and sections entided, "What is the answer (what is the question )," and "Conclusions and apologies."... 

The first task considered is the robust estimation of fitting parameters. Following to Peter Huber, the consideration is built at the assumption that the density function of the experimental random errors (8) can be presented in the following form ... 

The criteria chai acterizing the robustness of parameters of retention model for the changing of experimental data number were proposed to estimate the prediction capability of the models. 

Data collected by modern analytical instalments are usually presented by the multidimensional arrays. To perform the detection/identification of the supposed component or to verify the authenticity of a product, it is necessary to estimate the similarity of the analyte to the reference. The similarity is commonly estimated with the use of the distance between the multidimensional arrays corresponding to the compared objects. To exclude within the limits of the possible the influence of the random errors and the nonreproductivity of the experimental conditions and to make the comparison of samples more robust, it is possible to handle the arrays with the use of the fuzzy set theory apparatus. 

On a different note, after some 50 years of intensive research on high-pressure shock compression, there are still many outstanding problems that cannot be solved. For example, it is not possible to predict ab initio the time scales of the shock-transition process or the thermophysical and mechanical properties of condensed media under shock compression. For the most part, these properties must presently be evaluated experimentally for incorporation into semiempirical theories. To realize the potential of truly predictive capabilities, it will be necessary to develop first-principles theories that have robust predictive capability. This will require critical examination of the fundamental postulates and assumptions used to interpret shock-compression processes. For example, it is usually assumed that a steady state is achieved immediately after the shock-transition process. However, due to the fact that... 

Given robust experimental evidence of cannabis withdrawal, recent interest has focused on the extent to which medications may assist in the amelioration... 

Eq. (44)). In Eig. 20, we show the result of this approximation for reasonable a = 1 and cOc = 2 a/ Q )D- Even though these curves resemble the experimental data better than in the previous figure, they do not really provide more material support for the theory than the earlier method. This discussion simply demonstrates that the basic estimates are robust enough to survive different levels of treatment. Also, curiously, these curves reflect the experimental tendency that the higher T plateaus seem to have a more negative slope as compared to the low T ones (see Fig. 1), which was less obvious in Fig. 19. 

Considering all potential experimental and systematic errors of NOE/ROE crosspeak intensities, it is remarkable how robust the derived distance restraints still are. The reason Ues in the dependence of the cross-relaxation rate even if a cross-peak intensity is determined wrongly by a factor 2, the resulting distance restraint is only affected by the factor 1.12, which usually lies within the error range of distance restraints used in structure calculations. It should be further noted that the quaUty of a resulting structure is not so much determined by the... 

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