Reproducibility, data capture

Retention requirements for electronic records are discussed in Chapter 12. It is important to remember that electronic data capture can undermine data integrity. Image capture techniques may reproduce an original record very accurately, but if the original has insufficient dots per inch for clear reading, then the reproduction may not be usable. Electronic records are often not nearly as rugged and durable as their paper counterparts. The following factors may affect their life expectancy ... 

Data captured by the Rapid Underway Monitoring system show the increase in turbidity, and decrease in salinity, as well as the more diffuse increase in chlorophyll-a associated with the discharge from a major wastewater-treatment plant near the mouth of the Brisbane River. One useful application of the system is this capacity to map mixing and impact zones from discharges. (Reproduced from Hodge, ]., Longstaff, B., Steven, A., Thornton, P., Ellis, P., and McKelvie, I., Mur. Pol. Bull, 51,113, 2005. With permission.)... 

Documentation of experimental method so that work can be reproduced at a later time Appropriate data handling statistical methods conclusions based on fact, supportable by data Define and execute critical experiments to prove or disprove hypothesis Mechanistic or fundamental interpretation of data preferred Communication of Conclusions to Incorporate Technical Learning in Organization Experimental W rk Done in Support of New or Existing Processes Should be Captured in Process Models... 

To properly assess drug safety, we must be able to systematically tap the information captured in the massive amounts of medical data collected in both premarketing and postmarketing settings. In addition, as stated above, we must also be able to reproduce findings in different repositories of medical data in an auditable way. However, two major issues in studying drug safety confront us. 

Figure 3.8. Kinetic data from molecular beam experiments with NO + CO mixtures on a Pd/MgO(100) model catalyst [70]. The upper panel displays raw steady-state C02 production rates from the conversion of Pco = PN0 = 3.75 x 10-8 mbar mixtures as a function of the sample temperature on three catalysts with different average particle size (2.8, 6.9, and 15.6 nm), while the bottom panel displays the effective steady-state NO consumption turnover rates estimated by accounting for the capture of molecules in the support. After this correction, which depends on particle size, the medium-sized particles appear to be the most active for the NO conversion. (Reproduced with permission from Elsevier, Copyright 2000).

The detectors used with UPLC systems have to be able to handle very fast scanning methods because peak half-height widths of around 1 s are typically obtained with columns packed with 1.7-p.m particles. In order to accurately and reproducibly integrate an analyte peak, the detector sampling rate must be high enough to capture enough data points across the peak. Conceptually, the sensitivity increase for UPLC... 

Another viable method to compare experiments and theories are simulations of either the cell model with one or more infinite rods present or to take a solution of finite semi-flexible polyelectrolytes. These will of course capture all correlations and ionic finite size effects on the basis of the RPM, and are therefore a good method to check how far simple potentials will suffice to reproduce experimental results. In Sect. 4.2, we shall in particular compare simulations and results obtained with the DHHC local density functional theory to osmotic pressure data. This comparison will demonstrate to what extent the PB cell model, and furthermore the whole coarse grained RPM approach can be expected to hold, and on which level one starts to see solvation effects and other molecular details present under experimental conditions. 

In the study of Hietaniemi et al. [76], the model reproduced well most of the experiments conducted on spruce, but the calculated HRR was sensitive to the back-face boundary condition in the SBI test and the observed decay in the HRR in the cavity experiment was not captured by the model. Modeled HRR for medium density fiberboard closely matched room/corner test data, whereas HRR in the SBI test was not reproduced as closely. The HRR of the PVC wall carpet was reproduced reasonably well in the SBI test, but was overpredicted in the room corner test, probably owing to the discrepancy between the back-face boundary condition in reality and in the model. For the upholstered chair, FDS underestimated the time to ignition and the peak HRR compared with experimental data for both the furniture calorimeter and ISO room cases. Finally, for the polyethylene-sheathed cables in the 6 m cavity, the modeled HRR matched the experimental data fairly closely. In general, the results of Hietaniemi et al. [76] are encouraging. 

Wang and Charles Han calculated the electron affinities of aldehydes and ketones by using the parameterized Huckel theory. Eight parameters were used to calculate the electron affinities of 16 compounds with a deviation of only 0.05 eV. However, some of the data were not published until the 1970s [35]. By measuring relative electron capture coefficients and scaling to the acetophenone data, more precise electron affinities could be obtained. This was further support for the validity of the ECD model. M. J. S. Dewar reproduced the experimental electron affinities of aromatic hydrocarbons using the MINDO/3 method and calculated Ea from reduction potentials [36]. 

The ECD used to establish the kinetic model was custom-built. Affordable commercial ECD and negative-ion gas chromatograph chemical ionization mass spectrometers are now available. Thus in order for an investigator to use these techniques, it is simply a matter of calibrating the instrument by reproducing the experimental results to verify that no artifacts result from the equipment. The major work described in this book was conducted with the radioactive ECD. The mechanisms for the pulsed discharge electron capture detector are the same as with the radioactive ECD that is now commercially available [4]. We have used commercial detectors and a quadrupole mass spectrometer with a home-made data collection system to determine electron affinities and to study the complexes of negative ions [5-9]. 

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