Effects of pharmaceutical marketing:a re-analysis of the study of Windmeijer et al

Despite a growing body of scientific research, there is still much uncertainty about the effects of marketing expenditures on the demand for pharmaceuticals. Recently it was found that higher marketing expenditures for a brand may reduce the price elasticity of demand, and hence allow firms to charge higher prices (Windmeijer et al [1]). In this study we reconsider the study by Windmeijer et al. We find that their econometric models are based on an incorrect assumption of homogeneous parameters across brands. As a consequence, our conclusions concerning the effects of pharmaceutical marketing are different from theirs.

Flow field analysis of some mixing and conveying screw element regions, within a closely intermeshing, co-rotating twin-screw extruder.

Grafting of antioxidants and other modifiers onto polymers by reactive extrusion, has been performed successfully by the Polymer Processing and Performance Group at Aston University. Traditionally the optimum conditions for the grafting process have been established within a Brabender internal mixer. Transfer of this batch process to a continuous processor, such as an extruder, has, typically, been empirical. To have more confidence in the success of direct transfer of the process requires knowledge of, and comparison between, residence times, mixing intensities, shear rates and flow regimes in the internal mixer and in the continuous processor.The continuous processor chosen for the current work in the closely intermeshing, co-rotating twin-screw extruder (CICo-TSE). CICo-TSEs contain screw elements that convey material with a self-wiping action and are widely used for polymer compounding and blending. Of the different mixing modules contained within the CICo-TSE, the trilobal elements, which impose intensive mixing, and the mixing discs, which impose extensive mixing, are of importance when establishing the intensity of mixing. In this thesis, the flow patterns within the various regions of the single-flighted conveying screw elements and within both the trilobal element and mixing disc zones of a Betol BTS40 CICo-TSE, have been modelled using the computational fluid dynamics package Polyflow. A major obstacle encountered when solving the flow problem within all of these sets of elements, arises from both the complex geometry and the time-dependent flow boundaries as the elements rotate about their fixed axes. Simulation of the time dependent boundaries was overcome by selecting a number of sequential 2D and 3D geometries, used to represent partial mixing cycles. The flow fields were simulated using the ideal rheological properties of polypropylene and characterised in terms of velocity vectors, shear stresses generated and a parameter known as the mixing efficiency. The majority of the large 3D simulations were performed on the Cray J90 supercomputer situated at the Rutherford-Appleton laboratories, with pre- and postprocessing operations achieved via a Silicon Graphics Indy workstation. A mechanical model was constructed consisting of various CICo-TSE elements rotating within a transparent outer barrel. A technique has been developed using coloured viscous clays whereby the flow patterns and mixing characteristics within the CICo-TSE may be visualised. In order to test and verify the simulated predictions, the patterns observed within the mechanical model were compared with the flow patterns predicted by the computational model. The flow patterns within the single-flighted conveying screw elements in particular, showed good agreement between the experimental and simulated results.

Brady et al.'s (2005) service evaluation models: A replication and extension in China

The research described in this study replicates and extends the Brady et al., [Brady, M. K., Knight, G. A., Cronin Jr. J. Toma, G., Hult, M. and Keillor, B. D. (2005), emoving the Contextual Lens: A Multinational, Mult-setting Comparison of Service Evaluation Models, Journal of Retailing, 81(3), pp. 215-230] study suggestion that future research in service evaluations should focus on emerging service economies such as China. The intent of the research was to examine the suitability of the models suggested by Brady and colleagues in the Chinese market. The replication somewhat successfully duplicated their finding as to the superiority of the comprehensive service evaluation model. Additionally, we also sought to examine as to whether the service evaluation model is gender invariant. Our findings indicate that there are significant differences between gender. These findings are discussed relative to the limitations associated with the study.

Brady et al.'s (2005) service evaluation models: A replication and extension in China

The research described in this study replicates and extends the Brady et al., [Brady, M. K., Knight, G. A., Cronin Jr. J. Toma, G., Hult, M. and Keillor, B. D. (2005), emoving the Contextual Lens: A Multinational, Mult-setting Comparison of Service Evaluation Models, Journal of Retailing, 81(3), pp. 215-230] study suggestion that future research in service evaluations should focus on emerging service economies such as China. The intent of the research was to examine the suitability of the models suggested by Brady and colleagues in the Chinese market. The replication somewhat successfully duplicated their finding as to the superiority of the comprehensive service evaluation model. Additionally, we also sought to examine as to whether the service evaluation model is gender invariant. Our findings indicate that there are significant differences between gender. These findings are discussed relative to the limitations associated with the study.

Selectivity and timing performance of UK investment trusts

This study examines the selectivity and timing performance of 218 UK investment trusts over the period July 1981 to June 2009. We estimate the Treynor and Mazuy (1966) and Henriksson and Merton (1981) models augmented with the size, value, and momentum factors, either under the OLS method adjusted with the Newey-West procedure or under the GARCH(1,1)-in-mean method following the specification of Glosten et al. (1993; hereafter GJR-GARCH-M). We find that the OLS method provides little evidence in favour of the selectivity and timing ability, consistent with previous studies. Interestingly, the GJR-GARCH-M method reverses this result, showing some relatively strong evidence on favourable selectivity ability, particularly for international funds, as well as favourable timing ability, particularly for domestic funds. We conclude that the GJR-GARCH-M method performs better in evaluating fund performance compared with the OLS method and the non-parametric approach, as it essentially accounts for the time-varying characteristics of factor loadings and hence obtains more reliable results, in particular, when the high frequency data, such as the daily returns, are used in the analysis. Our results are robust to various in-sample and out-of-sample tests and have valuable implications for practitioners in making their asset allocation decisions across different fund styles. © 2012 Elsevier B.V.

Platinum-catalysed cinnamaldehyde hydrogenation in continuous flow

Platinum is one of the most widely used hydrogenation catalysts. Here we describe the translation of batch reactions to continuous flow, affording tunable C=O versus C=C hydrogenation over a Pt/SiO2 catalyst, resulting in high steady state activity and single-pass yields in the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol under mild conditions. Negligible catalyst deactivation occurs under extended flow operation due to removal of reactively-formed poisons from the reaction zone. Process intensification imparts a four-fold enhancement in cinnamyl alcohol productivity.