Information systems evaluation: Navigating through the problem domain

Information systems (IS) make it possible to improve organizational efficiency and effectiveness, which can provide competitive advantage. There is, however, a great deal of difficulty reported in the normative literature when it comes to the evaluation of investments in IS, with companies often finding themselves unable to assess the full implications of their IS infrastructure. Although many of the savings resulting from IS are considered suitable for inclusion within traditional accountancy frameworks, it is the intangible and non-financial benefits, together with indirect project costs that complicate the justification process. In exploring this phenomenon, the paper reviews the normative literature in the area of IS evaluation, and then proposes a set of conjectures. These were tested within a case study to analyze the investment justification process of a manufacturing IS investment. The idiosyncrasies of the case study and problems experienced during its attempts to evaluate, implement, and realize the holistic implications of the IS investment are presented and critically analyzed. The paper concludes by identifying lessons learnt and thus, proposes a number of empirical findings for consideration by decisionmakers during the investment evaluation process

Specific binding of large aggregates of amphiphilic molecules to the respective antibodies

The Binding of nonylphenol to respective antibodies immobilized on solid substrates was studied with the methods of total internal reflection ellipsometry (TIRE) and QCM (quartz crystal microbalance) impedance spectroscopy. The binding reaction was proved to be highly specific having an association constant of K-A = 1.6 x 10(6) mol(-1) L and resulted in an increase in both the adsorbed layer thickness of 23 nm and the added mass of 18.3 mu g/cm(2) at saturation. The obtained responses of both TIRE and QCM methods are substantially higher than anticipated for the immune binding of single molecules of nonylphenol. The mechanism of binding of large aggregates of nonylphenol was suggested instead. Modeling of the micelle of amphiphilic nonylphenol molecules in aqueous solutions yielded a micelle size of about 38 nm. The mechanism of binding of large molecular aggregates to respective antibodies can be extended to other hydrophobic low-molecular-weight toxins such as T-2 mycotoxin. The formation of large molecular aggregates of nonylphenol and T-2 mycotoxin molecules on the surface was proved by the AFM study