THE RELATIONSHIP OF CONTROL AND LEARNING TO PROJECT PERFORMANCE

ABSTRACT

Management controls can be divided into two types that can have opposite effects on organizational learning: behavioral controls, which promote efficiency but also stifle much of the learning opportunity, and outcome controls, which foster interaction among stakeholders can add to the learning environment. This article reports on a study that confirms these observations and explores the nature of their direct and indirect influences on project performance. Data from a sample of software development professionals confirms that behavioral controls and learning directly influence project performance, while outcome controls contribute only indirectly through their impact on learning.     

Similarity between class A and class B G-protein-coupled receptors exemplified through calcitonin gene-related peptide receptor modelling and mutagenesis studies

Modelling class B G-protein-coupled receptors (GPCRs) using class A GPCR structural templates is difficult due to lack of homology. The plant GPCR, GCR1, has homology to both class A and class B GPCRs. We have used this to generate a class A–class B alignment, and by incorporating maximum lagged correlation of entropy and hydrophobicity into a consensus score, we have been able to align receptor transmembrane regions. We have applied this analysis to generate active and inactive homology models of the class B calcitonin gene-related peptide (CGRP) receptor, and have supported it with site-directed mutagenesis data using 122 CGRP receptor residues and 144 published mutagenesis results on other class B GPCRs. The variation of sequence variability with structure, the analysis of polarity violations, the alignment of group-conserved residues and the mutagenesis results at 27 key positions were particularly informative in distinguishing between the proposed and plausible alternative alignments. Furthermore, we have been able to associate the key molecular features of the class B GPCR signalling machinery with their class A counterparts for the first time. These include the [K/R]KLH motif in intracellular loop 1, [I/L]xxxL and KxxK at the intracellular end of TM5 and TM6, the NPXXY/VAVLY motif on TM7 and small group-conserved residues in TM1, TM2, TM3 and TM7. The equivalent of the class A DRY motif is proposed to involve Arg^2.39, His^2.43 and Glu^3.46, which makes a polar lock with T^6.37. These alignments and models provide useful tools for understanding class B GPCR function.     

Technological Innovation: Regaining the Competitive Edge

ABSTRACT

Global competition has become a business reality. To become competitive, we must improve the rate at which new technical concepts are incorporated into our products and processes. This article describes the sources and driving forces of innovation and the creative environment that the engineering manager must consider to increase the innovative productivity of the organization. Managers must also recognize the impact that the technical education system has on future innovative productivity and take the initiative to improve it. They must emphasize the importance of systems and process research and support such programs. In addition, idea generation must be considered just as important as analysis to the long-term success of the technological enterprise.     

Modelling of pharmaceutical tablet swelling and dissolution using discrete element method

This work presents a novel use of the Discrete Element Method (DEM) combined with inter-particle mass transfer in order to simulate polymer swelling and dissolution. Each particle can absorb water and swell, pushing on its neighbours and causing an overall expansion. Once the disentanglement threshold is reached, the polymer dissolves and the particle reduces in size. This paper applies DEM to simulate the radial swelling and dissolution of cylindrical tablets. The method was validated against exact numerical solution of the same system to assess the accuracy of the DEM simulations for different DEM particle sizes. Parametric studies were done to assess the impact of physical parameters – namely the concentration-dependent diffusion coefficient of water through the polymer, the dissolution rate constant of the polymer and the disentanglement threshold of the polymer – on the radial expansion of the tablet. It was found that different settings of the concentration-dependent water diffusion coefficient function could produce similar radial expansion curves but with different internal concentration profiles. Increasing the dissolution rate constant or decreasing the disentanglement threshold of the polymer caused a reduction in the maximum radius of tablet. Lastly, ATR-FTIR spectroscopic imaging was used to obtain chemical images of a pure hydroxy-propyl methylcellulose (HPMC) tablet swelling and dissolving. The model was optimised to match both the HPMC tablet radius and the concentration profiles over time.     

Photoclickable Surfaces for Profluorescent Covalent Polymer Coatings

The nitrile imine‐mediated tetrazole‐ene cycloaddition reaction (NITEC) is introduced as a powerful and versatile conjugation tool to covalently ligate macromolecules onto variable (bio)surfaces. The NITEC approach is initiated by UV irradiation and proceeds rapidly at ambient temperature yielding a highly fluorescent linkage. Initially, the formation of block copolymers by the NITEC methodology is studied to evidence its efficacy as a macromolecular conjugation tool. The grafting of polymers onto inorganic (silicon) and bioorganic (cellulose) surfaces is subsequently carried out employing the optimized reaction conditions obtained from the macromolecular ligation experiments and evidenced by surface characterization techniques, including X‐ray photoelectron spectroscopy and FT‐IR microscopy. In addition, the patterned immobilization of variable polymer chains onto profluorescent cellulose is achieved through a simple masking process during the irradiation.     

Relative Rates of Reaction of Silver Bromide with Adsorbed Monolayers of Derivatives of Thiourea*

Thiourea and many of its derivatives are strongly adsorbed by silver bromide to form a monolayer. The adsorbed thiourea prevents adsorption of certain dye ions, but these dyes are rapidly adsorbed after reaction between the thiourea and silver bromide occurs. Use is made of this fact to measure the rate of reaction in the adsorbed layer.

Adsorption and reaction-rate data were obtained for thiourea and the following derivatives: methyl, 1.1-dimethyl, 1,1,3-trimethyl, 1,1,3.3-tetramethyl, allyl, acetyl, phenyl, 1,3-diethyl, 1,3-di-n-butyl. l-ethanol-3-allyl, and l-ethanol-3-phenyl. Only the 1,3-dibutylthiourea showed evidence of significant multilayer adsorption. Electron donor groups (methyl, ethyl) decrease the rate of reaction of the adsorbed thiourea; electron acceptor groups (ethanol, acetyl, phenyl, allyl) increase the rate. Tetramethylthiourea is substantially inert. Sulphide formed by reaction of thiourea and silver bromide catalyzes the reaction of thiourea and of its derivatives. The mechanism of the reaction is discussed on the basis of the experimental results.     

A landmark‐bounded method for large‐scale underground mine mapping

A practical localization technology for underground drift networks—such as those excavated in the practice of underground mining—has yet to become commercially available. This paper focuses on the problem of mapping GPS‐deprived underground environments with the eventual goal of using these maps for navigation. Recent industry‐directed work in the creation of a landmark‐bounded occupancy grid mapping tool that combines odometry, scanning laser data, and sporadically placed passive RFID tags is described. Unlike other work, the suggested approach holds the philosophy that precise localization of the actual landmark locations is not necessary; rather, landmarks serve as a global means for partitioning the map. Successful field experiments were conducted in two underground environments, with the results used to conduct a basic analysis of the described method. © 2012 Wiley Periodicals, Inc.