Cross validation protocols

STE = 0.64). The same cross-validation protocol was carried out in the case of Pyrazolopyrimidine series obtaining the following correlation coefficients r2on. cv = 0.78 (STE =... 

A misconception, which still occurs in the literature, is that a cross-validation could serve as a local indicator rather than a global guide for the whole structure determination protocol. Cross-validation cannot be sufficiently sensitive to indicate as to whether a particular side chain could be built into one or another conformation. 

A VMP should be divided into chapters covering different subjects. First, an introduction should state the manufacture s validation policy, general description of the scope of those validation activities covered by the VMP, and their objectives, derivation, location, and schedule. Then, it must declare all validation activities and their organizational structure in terms of personnel responsibility for the VMP, validation protocols, validation work, report and document preparation projects, approval of the same validation protocols, reports in all stages of validation processes, and the training needs in support of validation. Other requirements of the VMP are cross references to other documents and to specific characteristics of the processes that are critical for yielding a quality product. Next, all validation activities comprised in the VMP should be summarized and compiled in a matrix format. Such a matrix should provide an overview and contain all items covered by the VMP that... 

A validation report is a written document that cross-references the validation protocol, summarizes the results obtained, describes any deviations observed, and draws the necessary conclusions, including recommending changes required to correct deficiencies for the qualification and validation performed [5]. In this report it is required to present both the results and conclusions and the secure approval of the study. The report should include a summary of the procedures used to clean, sample, and test as well as the physical and analytical test results or references for the same. The conclusions regarding the acceptability of the results should also be included. Other information would be the status of the procedures being validated, any recommendations based on the results, or any relevant information obtained during the study. These include, re validation practices (if applicable), the approved conclusions, and any deviations of the protocol that might have occurred. In cases where it is unlikely that further batches of the product will be manufactured for a period... 

A report that cross-references the qualification and/or validation protocol should be prepared, summarizing the results obtained, commenting on any deviation observed and drawing the necessary conclusions, including recommended changes necessary to correct deficiencies. Any changes in the plan as defined in the protocol should be documented with the appropriate justification. 

Sometimes a clinical site may deviate from the study protocol-defined sample-collection procedures. For example, instead of collecting blood into heparinized tubes, the sample may be collected into a tube containing another anticoagulant, such as citrate or EDTA. Under these conditions, it is necessary to cross-validate each of the plasma/serum matrices QC samples in the deviant matrix must be prepared and processed along with the deviant samples to ensure that the method is validated in the new matrix. 

Space by automated model updating protocols where all new data are retrieved and used in an automated model rebuilding and validation process on a regular basis. Internal validation strategies such as cross validation and hold-out validation complement external and temporal test sets in the assessment of the generalization accuracy. 

The Problem (vahdation requirements in this case) should be clearly defined with highly specific definitions for the scope and objectives of the work to be undertaken. If part of a larger program, the protocol may include an overview of all other activities relating to the work, e.g. cross validation activities at another laboratory, but more likely a vahdation protocol will be focused on the analytical portion of the study and the procedures to be conducted in a particular laboratory. 

Ungwitayatorn et al. [240] reported the 3D-QSAR CoMFA/CoMSIA studies for a series of 30 Chromone derivatives of HIVPI. The dataset was divided into a training/test set of 30/5 compounds based on the distribution of biological activity and the variety of substitution pattern. Superposition and field fit alignment criteria were used for model development in CoMFA. The best predictive CoMFA model with steric (46%) and electrostatic (54%) fields gave cross-validated of 0.763 and non-cross-validated of 0.967 with a standard error of estimate (S) of 5.092. The PLS protocol and stepwise procedure were... 

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