The interaction between the use of information technology and organizational culture

The interaction between the use of information technology, (IT) in organizations and that organization's culture is examined. The interaction is considered from the early stages of specification through to the regular use of the systems. The changes in the technological artefacts which result from the use of IT are discussed. Some suggestions about control of the interaction are made.     

Structural determinants of the interaction between the erbB2 receptor and the Src homology 2 domain of Grb7

The Src homology 2 (SH2) domain-containing protein Grb7 and the erbB2 receptor tyrosine kinase are overexpressed in a subset of human breast cancers. They also co-immunoprecipitate from cell lysates and associate directly in vitro. Whereas the Grb7 SH2 domain binds strongly to erbB2, the SH2 domain of Grb14, a protein closely related to Grb7, does not. We have investigated the preferred binding site of Grb7 within the erbB2 intracellular domain and the SH2 domain residues that determine the high affinity of Grb7 compared with Grb14 for this site. Phosphopeptide competition and site-directed mutagenesis revealed that Tyr-1139 of erbB2 is the major binding site for the Grb7 SH2 domain, indicating an overlap in binding specificity between the Grb7 and Grb2 SH2 domains. Substituting individual amino acids in the Grb14 SH2 domain with the corresponding residues from Grb7 demonstrated that a Gln to Leu change at the betaD6 position imparted high affinity erbB2 interaction, paralleled by a marked increase in affinity for the Tyr-1139 phosphopeptide. The reverse switch at the betaD6 position abrogated Grb7 binding to erbB2. This residue therefore represents an important determinant of SH2 domain specificity within the Grb7 family.     

Lack of relationship between CDK activity and G1 cyclin expression in breast cancer cells

The G1 cyclins, cyclin D1 and E, are rate limiting for progression through G1 phase of the cell cycle in breast epithelial cells and are oncogenic when expressed in the mammary epithelium of transgenic mice. These genes are frequently overexpressed in clinical breast cancer where overexpression appears to be associated with specific disease phenotypes, altered responsiveness to therapeutic intervention and patient survival. In order to investigate the functional correlates of cyclin D1 and cyclin E overexpression we employed a panel of normal, immortalized and neoplastic breast epithelial cell lines to examine the relationships between cyclin gene expression, cyclin-CDK complex formation and CDK activity. In agreement with earlier studies cyclin D1 and E expression varied over an approximately tenfold range among the 18 cell lines studied. There was no apparent relationship, however, between cyclin D1 expression and the in vitro activity of its major kinase partner, Cdk4, although MDA-MB-134 cells displayed the highest level of both cyclin D1 expression and Cdk4 activity. Similarly, there was no significant relationship between cyclin E expression and cyclin E-Cdk2 activity. Fractionation of whole cell lysates by gel filtration chromatography revealed that approximately 90% of the cyclin E protein was present in inactive complexes containing the CDK inhibitors p21 and p27. Much of the small fraction of active cyclin E protein was of very high apparent molecular mass, >400 kDa, suggesting that formation of these complexes is a more important determinant of cyclin E-Cdk2 activity than cyclin E abundance. These data suggest that properties of cyclins D1 and E in addition to their ability to activate Cdk4 and Cdk2 may contribute to the effects of overexpression on the breast cancer phenotype.     

Human cerebral neoplasms studied using MR spectroscopy: a review

Of primary central nervous system tumors treated each year, the majority are glioma, followed by meningioma and then pituitary adenoma. While the use of magnetic resonance (MR) and computed tomographic imaging is well established in the diagnosis and management of such tumors, these techniques have a limited role in determining the metabolic state, either prior to or following therapy. Multinuclear MR spectroscopy, on the other hand, provides information on tumor metabolism and the effect of therapy on tumor viability. This paper reviews MR spectroscopic studies performed on patients with central nervous system tumors and discusses the impact that such studies have had on tumor diagnosis and management.     

Similarity study of large steam line break LOCA's in ROSA-III, FIST and BWR/6

Similarity of the thermal hydraulic phenomena in a 100% steam line break loss-of-coolant accident (LOCA) between the Rig-of-Safety Assessment (ROSA)-III. Full-Integral Simulation Test (FIST) and a boiling water reactor (BWR)/6 system has been studied experimentally and analytically. The experimental results of ROSA-III (RUN952) and FIST (6MSB1) showed similar LOCA phenomena except for the core cooling. The core cooling was affected by the different ECCS actuation logics used in the tests. The effects of the different test conditions and the system-inherent features on the LOCA phenomena were separately evaluated through the post-test and similarity analysis of the ROSA-III and FIST tests by using RELAP5/MOD1 code with a jet pump model. The similarity of the major events in the ROSA-III and FIST facilities to those of BWR/6 system were confirmed assuming the same ECCS actuation logic and the same sealed initial mass inventory among the three systems. Differences in vessel geometries, metal stored heat and core power curves caused slight differences in the responses of pressure and fuel surface temperatures.     

Human monoclonal antibodies to human blood group antigens Kidd Jka and Jkb

Three IgM human monoclonal antibodies to Jkb, and one IgM human monoclonal antibody to Jka were produced from the lymphocytes of two immunized donors. Two of the anti-Jkb monoclonal antibodies (MS-7 and MS-9) are of the IgM (kappa) isotype and one (MS-8) is an IgM(lambda). The anti-Jka monoclonal antibody (MS-15) is of the IgM(kappa) isotype. They are all specific for their respective antigens, and give positive agglutinations in saline by the immediate spin technique, even against Jk(a+b+) cells. The heterohybridomas have been shown to be suitable for bulk culture and produce levels of antibody that reach 18 micrograms/ml in the spent culture supernatant. They offer considerable advantages over currently available reagents in terms of stability, simplicity and speed of use, and will provide a reliable and unlimited supply of what are at the moment rare and unsatisfactory antibodies.     

Patterns of discussion between pupil pairs in computer and non-computer environments

Abstract This paper presents some findings of research into the discussion between pupils in computer and non-computer environments. The research was concerned with analysing the processes whereby pairs of pupils came to make mathematical generalizations in three environments, LOGO , spreadsheet and paper and pencil. Critical decisions in the generalization process were identified in order to allow comparisons to be made across environments. The analysis reveals differences in the effects of task environment on the negotiation of the mathematical generalization particularly in relation to the part played by formalization.     

Individual mating success, lek stability, and the neglected limitations of statistical power

The evolution of leks (aggregations of males displaying to females) cannot be explained solely by an increasing average gain in matings for each male as group size increases. This is because the mating skew, that is, the inequality among males in mating success, is often high and may vary with lek size. Here, we show that the common observation that matings become more evenly divided as lek size increases is also insufficient to explain by itself the benefits of aggregating. The benefits to individual males are highly sensitive to the exact relationship between mating skew and lek size, and very similar relationships can lead to opposite predictions concerning individual benefits. With data on published mating success for 18 species (71 leks), we show that different species have very similar skew versus lek size relationships. With current sample sizes, however, there is insufficient statistical power to distinguish between completely different alternatives concerning individual optima of males. Copyright 1998 The Association for the Study of Animal Behaviour