Harnessing Intellectual Resources in a Collaborative Context to Create Value

The value of electronic collaboration has arisen as successful organisations recognize that they need to convert their intellectual resources into customized services. The shift from personal computing to interpersonal or collaborative computing has given rise to ways of working that may bring about better and more effective use of intellectual resources. Current efforts in managing knowledge have concentrated on producing; sharing and storing knowledge while business problems require the combined use of these intellectual resources to enable organisations to provide innovative and customized services. In this chapter the collaborative context is developed using a model for electronic collaboration through the use of which organisations may mobilse collaborative technologies and intellectual resources towards achieving joint effect

What Does It Mean for an Organisation to Be Intelligent? Measuring intellectual bandwidth for value creation

The importance of electronic collaboration has risen as successful organisations recognize that they need to convert their intellectual resources into goods and services their customers will value. The shift from personal computing to interpersonal or collaborative computing has given rise to ways of working that may bring about better and more effective use of intellectual resources. Current efforts in managing knowledge have concentrated on producing, sharing and storing knowledge while business problems require the use of these intellectual resources to create value. This paper draws upon Nunamaker et. al.'s (2001) Intellectual Bandwidth Model to measure an organization's potential to create value. Following an analysis of initial data collected at the Netherlands branch of Cap-Gemini Ernst & Young, conclusions are drawn with respect to what it means for an organisation to be intelligent and how such organisations can create value through the use of information and collaboration technologies to increase its intellectual bandwidth

Selection of Inhibitor-Resistant Viral Potassium Channels Identifies a Selectivity Filter Site that Affects Barium and Amantadine Block

BACKGROUND:Understanding the interactions between ion channels and blockers remains an important goal that has implications for delineating the basic mechanisms of ion channel function and for the discovery and development of ion channel directed drugs. METHODOLOGY/PRINCIPAL FINDINGS:We used genetic selection methods to probe the interaction of two ion channel blockers, barium and amantadine, with the miniature viral potassium channel Kcv. Selection for Kcv mutants that were resistant to either blocker identified a mutant bearing multiple changes that was resistant to both. Implementation of a PCR shuffling and backcrossing procedure uncovered that the blocker resistance could be attributed to a single change, T63S, at a position that is likely to form the binding site for the inner ion in the selectivity filter (site 4). A combination of electrophysiological and biochemical assays revealed a distinct difference in the ability of the mutant channel to interact with the blockers. Studies of the analogous mutation in the mammalian inward rectifier Kir2.1 show that the T-->S mutation affects barium block as well as the stability of the conductive state. Comparison of the effects of similar barium resistant mutations in Kcv and Kir2.1 shows that neighboring amino acids in the Kcv selectivity filter affect blocker binding. CONCLUSIONS/SIGNIFICANCE:The data support the idea that permeant ions have an integral role in stabilizing potassium channel structure, suggest that both barium and amantadine act at a similar site, and demonstrate how genetic selections can be used to map blocker binding sites and reveal mechanistic features

Resolution of Abfraction-Associated Gingival Fenestration Utilizing Connective Tissue Grafting

Introduction. Gingival fenestration (GF) is a distinct clinical entity of uncertain etiology that is seldom documented in the literature. It has been associated mainly with submucosal mechanical irritants such as calculus that subsequently create an opening in the oral soft tissue, usually at facial anterior sites. Surgical correction may be indicated to address functional and/or esthetic concerns. Case Presentation. The patient, a 74-year-old male, presented to the clinic with a chief complaint of “something is poking through my gum.” Clinical exam revealed a gingival fenestration on the facial of tooth #11, associated with what appeared to be a pronounced noncarious cervical lesion (NCCL). Surgical treatment consisted of a connective tissue graft and odontoplasty of the sharp protruding edge of the root surface. Healing was uneventful with excellent closure of the fenestration and no evidence of recurrence after 18 months of follow-up. Conclusion. GF is a perforation of the mucosa typically associated with underlying sharp mechanical etiology. This report describes a fenestration that developed from a probable abfractive lesion, which later was successfully closed and exhibits long-term stability

A role for the middle C terminus of G-protein-activated inward rectifier potassium channels in regulating gating

We have used sulfhydryl-modifying reagents to investigate the regulation of G-protein-activated inward rectifier potassium (GIRK) channels via their cytoplasmic domains. Modification of either the conserved N-terminal cysteines (GIRK1C53 and GIRK2C65) or the middle C-terminal cysteines (GIRK1C310 and GIRK2C321) independently inhibited GIRK1/GIRK2 heteromeric channels. With the exception of GIRK2C65, these cysteines were relatively inaccessible to large modifying reagents. The accessibility was further reduced by a mutation at the end of the second transmembrane domain that stabilized the open state of the channel. Thus it is unlikely that these cysteines line the permeation pathway of the open pore. Cysteines introduced 3 and 6 amino acids upstream of GIRK2C321 (G318C and E315C) were considerably more accessible. The effect of modification was dependent on the charge of the reagent. Modification of E315C in GIRK2 and E304C in GIRK1 by sodium (2-sulfonatoethyl) methanethiosulfonate (MTSES(-)) increased the current by approximately 17-fold, whereas modification by 2-aminoethyl methanethiosulfonate hydrochloride (MTSEA(+)), abolished the current. There was no effect on single-channel conductance. Thus a switch in charge at this middle C-terminal position was sufficient to gate the channel open and closed. This glutamate is conserved in all members of the Kir family. The E303K mutation in Kir2.1 inhibits channel function and causes Andersen's syndrome in humans (Plaster, N. M., Tawil, R., Tristani-Firouzi, M., Canun, S., Bendahhou, S., Tsunoda, A., Donaldson, M. R., Iannaccone, S. T., Brunt, E., Barohn, R., Clark, J., Deymeer, F., George, A. L., Jr., Fish, F. A., Hahn, A., Nitu, A., Ozdemir, C., Serdaroglu, P., Subramony, S. H., Wolfe, G., Fu, Y. H., and Ptacek, L. J. (2001) Cell 105, 511-519 and Preisig-Muller, R., Schlichthorl, G., Goerge, T., Heinen, S., Bruggemann, A., Rajan, S., Derst, C., Veh, R. W., and Daut, J. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 7774-7779). Our results suggest that this residue regulates channel gating through an electrostatic mechanism

Abscisic acid regulation of guard-cell K+ and anion channels in Gβ- and RGS-deficient Arabidopsis lines

In mammals, basal currents through G protein-coupled inwardly rectifying K+ (GIRK) channels are repressed by Gαi/oGDP, and the channels are activated by direct binding of free Gβγ subunits released upon stimulation of Gαi/o-coupled receptors. However, essentially all information on G protein regulation of GIRK electrophysiology has been gained on the basis of coexpression studies in heterologous systems. A major advantage of the model organism, Arabidopsis thaliana, is the ease with which knockout mutants can be obtained. We evaluated plants harboring mutations in the sole Arabidopsis Gα (AtGPA1), Gβ (AGB1), and Regulator of G protein Signaling (AtRGS1) genes for impacts on ion channel regulation. In guard cells, where K+ fluxes are integral to cellular regulation of stomatal apertures, inhibition of inward K+ (Kin) currents and stomatal opening by the phytohormone abscisic acid (ABA) was equally impaired in Atgpa1 and agb1 single mutants and the Atgpa1 agb1 double mutant. AGB1 overexpressing lines maintained a wild-type phenotype. The Atrgs1 mutation did not affect Kin current magnitude or ABA sensitivity, but Kin voltage-activation kinetics were altered. Thus, Arabidopsis cells differ from mammalian cells in that they uniquely use the Gα subunit or regulation of the heterotrimer to mediate Kin channel modulation after ligand perception. In contrast, outwardly rectifying (Kout) currents were unaltered in the mutants, and ABA activation of slow anion currents was conditionally disrupted in conjunction with cytosolic pH clamp. Our studies highlight unique aspects of ion channel regulation by heterotrimeric G proteins and relate these aspects to stomatal aperture control, a key determinant of plant biomass acquisition and drought tolerance

Using Yeast to Study Potassium Channel Function and Interactions with Small Molecules

Analysis of ion channel mutants is a widely used approach for dissecting ion channel function and for characterizing the mechanisms of action of channel-directed modulators. Expression of functional potassium channels in potassium-uptake-deficient yeast together with genetic selection approaches offers an unbiased, high-throughput, activity-based readout that can rapidly identify large numbers of active ion channel mutants. Because of the assumption-free nature of the method, detailed biophysical analysis of the functional mutants from such selections can provide new and unexpected insights into both ion channel gating and ion channel modulator mechanisms. Here, we present detailed protocols for generation and identification of functional mutations in potassium channels using yeast selections in the potassium-uptake-deficient strain SGY1528. This approach is applicable for the analysis of structure–function relationships of potassium channels from a wide range of sources including viruses, bacteria, plants, and mammals and can be used as a facile way to probe the interactions between ion channels and small-molecule modulators