bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge creation and its place in the development of sustainable competitive advantage
Authors: Sharkie Rob
Published: April 2003

Organizations operate in all areas through people and it is their contribution which determines success and it is their skills and knowledge which need to be cultivated and then leveraged to create competitive advantage. Sustainability of this competitive advantage comes from the development of tightly coordinated and complementary activities and directed towards producing a strategy of differentiation and making a unique offering to customers. A consistency in strategic direction is essential and this will necessitate the exercise of choice to develop a unique strategy. The development of sustainable competitive advantage is a vital management function and an important requirement is the nurturing of a knowledge creating environment to enable the organization to exploit and develop resources better than rivals and create sufficient knowledge to address the industry’s future success factors.
Enabling knowledge creation: learning from an R&D organization
Authors: Roth Jonas
Published: April 2003

The ability to create knowledge and diffuse it throughout an organization is today recognized as a major strategic capability for gaining competitive advantage. Scholars and managers have shown an increasing interest in understanding and managing organizational knowledge. Despite this, there are few examples in the literature that bridge the gap between knowledge and knowledge application. This article develops a knowledge management initiative which facilitates knowledge creation and sharing beyond project boundaries, based on exploratory research at pharmaceutical company AstraZeneca. The results indicate that, by allowing the emergence of knowledge facilitators, practical knowledge for action is produced and shared. The article explores the dynamic and relational nature of knowledge when managing knowledge, it then develops actionable tools for lateral knowledge creation and knowledge transfer, and concludes with implications for managers using the tools.
Using “knowledge champions” to facilitate knowledge management
Authors: Jones Nory B. , Herschel Richard T. , Moesel Douglas D.
Published: April 2003

Executives and strategists have long recognized the value of knowledge as a primary driving source for a firm’s sustainable competitive advantage – hence the creation by many firms of a position called the chief knowledge officer (CKO). However, many people have proposed differing perspectives and models relating to the concept of knowledge management. In this paper differing knowledge management viewpoints are examined, by examining and integrating theories relating to the diffusion of innovations and change agents. The roles of change agents, innovators, and opinion leaders, such as CKOs, are explored in terms of effective knowledge management strategies and techniques. A model and strategies are proposed that can serve as a framework for CKOs and other knowledge management change agents to effectively facilitate the acquisition and use of knowledge in the firm by effectively using an organizational memory system.
Motivation and barriers to participation in virtual knowledge‐sharing communities of practice
Authors: Ardichvili Alexander , Page Vaughn , Wentling Tim
Published: April 2003

This paper reports the results of a qualitative study of motivation and barriers to employee participation in virtual knowledge‐sharing communities of practice at Caterpillar Inc., a Fortune 100, multinational corporation. The study indicates that, when employees view knowledge as a public good belonging to the whole organization, knowledge flows easily. However, even when individuals give the highest priority to the interests of the organization and of their community, they tend to shy away from contributing knowledge for a variety of reasons. Specifically, employees hesitate to contribute out of fear of criticism, or of misleading the community members (not being sure that their contributions are important, or completely accurate, or relevant to a specific discussion). To remove the identified barriers, there is a need for developing various types of trust, ranging from the knowledge‐based to the institution‐based trust. Future research directions and implications for KM practitioners are formulated.
Does health care for knowledge management?
Authors: Van Beveren John
Published: April 2003

This study explores knowledge management within an Australian regional health care organization. Many barriers inherent in the organizational structure and design of the organization that are indicative of the public health sector have been identified and discussed. From the results and discussion it is concluded that new models, tools and techniques for knowledge management specific to the environment of the public sector and particularly the health sector are required.
Knowledge workers: exploring the link among performance rating, pay and motivational aspects
Authors: Smith Alan D. , Rupp William T.
Published: April 2003

Historically, performance appraisals were intended to focus on three areas: development, motivation, and recognition of achievement. One major purpose of performance appraisals is to determine individual merit, especially where pay for performance systems are employed. Based upon expectancy theory, high performance ratings should entail high merit increases while low performance ratings result in low merit increases. However, it appears that decoupling performance ratings and merit increases is common practice. This paper explores the effects of receiving a low performance rating and high merit increase or a high performance rating and a low merit increase and empirically investigate its impact on knowledge workers’ motivational and general morale.
The future of the Balanced Scorecard: an interview with Professor Dr Robert S. Kaplan
Authors: de Waal André A.
Published: April 2003

Without doubt Robert Kaplan has been, in the last decade, and continues to be the most influential thinker in the field of performance management, and his Balanced Scorecard is the most successful concept in this field. The article is a summary of an interview with Robert Kaplan, co‐author of The Balanced Scorecard, Translating Strategy into Action (Harvard Business School Press, 1996). The Balanced Scorecard, measures that drive performance (Harvard Business Review, January/February 1992) and The strategy‐focused organization, how balanced scorecard companies thrive in the new business environment (Harvard Business School Press, 2000).
Use of In-Biofilm Expression Technology To Identify Genes Involved in
Pseudomonas aeruginosa
Biofilm Development
Authors: Finelli Antonio , Gallant Claude V. , Jarvi Keith , Burrows Lori L.
Published: April 2003

Mature
Pseudomonas aeruginosa
biofilms form complex three-dimensional architecture and are tolerant of antibiotics and other antimicrobial compounds. In this work, an in vivo expression technology system, originally designed to study virulence-associated genes in complex mammalian environments, was used to identify genes up-regulated in
P. aeruginosa
grown to a mature (5-day) biofilm. Five unique cloned promoters unable to promote in vitro growth in the absence of purines after recovery from the biofilm environment were identified. The open reading frames downstream of the cloned promoter regions were identified, and knockout mutants were generated. Insertional mutation of PA5065, a homologue of
Escherichia coli ubiB
, was lethal, while inactivation of PA0240 (a porin homologue), PA3710 (a putative alcohol dehydrogenase), and PA3782 (a homologue of the
Streptomyces griseus
developmental regulator
adpA
) had no effect on planktonic growth but caused defects in biofilm formation in static and flowing systems. In competition experiments, mutants demonstrated reduced fitness compared with the parent strain, comprising less than 0.0001% of total biofilm cells after 5 days. Therefore, using in-biofilm expression technology, we have identified novel genes that do not affect planktonic growth but are important for biofilm formation, development, and fitness.
Chaperone-Subunit-Usher Interactions Required for Donor Strand Exchange during Bacterial Pilus Assembly
Authors: Barnhart Michelle M. , Sauer Frederic G. , Pinkner Jerome S. , Hultgren Scott J.
Published: April 2003

The assembly of type 1 pili on the surface of uropathogenic
Escherichia coli
proceeds via the chaperone-usher pathway. Chaperone-subunit complexes interact with one another via a process termed donor strand complementation whereby the G1β strand of the chaperone completes the immunoglobulin (Ig) fold of the pilus subunit. Chaperone-subunit complexes are targeted to the usher, which forms a channel across the outer membrane through which pilus subunits are translocated and assembled into pili via a mechanism known as donor strand exchange. This is a mechanism whereby chaperone uncapping from a subunit is coupled with the simultaneous assembly of the subunit into the pilus fiber. Thus, in the pilus fiber, the N-terminal extension of every subunit completes the Ig fold of its neighboring subunit by occupying the same site previously occupied by the chaperone. Here, we investigated details of the donor strand exchange assembly mechanism. We discovered that the information necessary for targeting the FimC-FimH complex to the usher resides mainly in the FimH protein. This interaction is an initiating event in pilus biogenesis. We discovered that the ability of an incoming subunit (in a chaperone-subunit complex) to participate in donor strand exchange with the growing pilus depended on a previously unrecognized function of the chaperone. Furthermore, the donor strand exchange assembly mechanism between subunits was found to be necessary for subunit translocation across the outer membrane usher.
Natural Variation in the Microcystin Synthetase Operon
mcyABC
and Impact on Microcystin Production in
Microcystis
Strains
Authors: Mikalsen Bjørg , Boison Gudrun , Skulberg Olav M. , Fastner Jutta , Davies William , Gabrielsen Tove M. , Rudi Knut , Jakobsen Kjetill S.
Published: April 2003

Toxic
Microcystis
strains often produce several isoforms of the cyclic hepatotoxin microcystin, and more than 65 isoforms are known. This has been attributed to relaxed substrate specificity of the adenylation domain. Our results show that in addition to this, variability is also caused by genetic variation in the microcystin synthetase genes. Genetic characterization of a region of the adenylation domain in module
mcyB1
resulted in identification of two groups of genetic variants in closely related
Microcystis
strains. Sequence analyses suggested that the genetic variation is due to recombination events between
mcyB1
and the corresponding domains in
mcyC
. Each variant could be correlated to a particular microcystin isoform profile, as identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Among the
Microcystis
species studied, we found 11 strains containing different variants of the
mcyABC
gene cluster and 7 strains lacking the genes. Furthermore, there is no concordance between the phylogenies generated with
mcyB1
, 16S ribosomal DNA, and DNA fingerprinting. Collectively, these results suggest that recombination between imperfect repeats, gene loss, and horizontal gene transfer can explain the distribution and variation within the
mcyABC
operon.
Characterization of Chlorophenol 4-Monooxygenase (TftD) and NADH:Flavin Adenine Dinucleotide Oxidoreductase (TftC) of
Burkholderia cepacia
AC1100
Authors: Gisi Michelle R. , Xun Luying
Published: April 2003

Burkholderia cepacia
AC1100 uses 2,4,5-trichlorophenoxyacetic acid, an environmental pollutant, as a sole carbon and energy source. Chlorophenol 4-monooxygenase is a key enzyme in the degradation of 2,4,5-trichlorophenoxyacetic acid, and it was originally characterized as a two-component enzyme (TftC and TftD). Sequence analysis suggests that they are separate enzymes. The two proteins were separately produced in
Escherichia coli
, purified, and characterized. TftC was an NADH:flavin adenine dinucleotide (FAD) oxidoreductase. A C-terminally His-tagged fusion TftC used NADH to reduce either FAD or flavin mononucleotide (FMN) but did not use NADPH or riboflavin as a substrate. Kinetic and binding property analysis showed that FAD was a better substrate than FMN. TftD was a reduced FAD (FADH
2
)-utilizing monooxygenase, and FADH
2
was supplied by TftC. It converted 2,4,5-trichlorophenol to 2,5-dichloro-
p
-quinol and then to 5-chlorohydroxyquinol but converted 2,4,6-trichlorophenol only to 2,6-dichloro-
p
-quinol as the final product. TftD interacted with FADH
2
and retarded its rapid oxidation by O
2
. A spectrum of possible TftD-bound FAD-peroxide was identified, indicating that the peroxide is likely the active oxygen species attacking the aromatic substrates. The reclassification of the two enzymes further supports the new discovery of FADH
2
-utilizing enzymes, which have homologues in the domains
Bacteria
and
Archaea
.
Genetic Analysis of Pathway Specificity during Posttranslational Protein Translocation across the
Escherichia coli
Plasma Membrane
Authors: Blaudeck Natascha , Kreutzenbeck Peter , Freudl Roland , Sprenger Georg A.
Published: April 2003

In
Escherichia coli
, the SecB/SecA branch of the Sec pathway and the twin-arginine translocation (Tat) pathway represent two alternative possibilities for posttranslational translocation of proteins across the cytoplasmic membrane. Maintenance of pathway specificity was analyzed using a model precursor consisting of the mature part of the SecB-dependent maltose-binding protein (MalE) fused to the signal peptide of the Tat-dependent TorA protein. The TorA signal peptide selectively and specifically directed MalE into the Tat pathway. The characterization of a spontaneous TorA signal peptide mutant (TorA*), in which the two arginine residues in the c-region had been replaced by one leucine residue, showed that the TorA*-MalE mutant precursor had acquired the ability for efficiently using the SecB/SecA pathway. Despite the lack of the “Sec avoidance signal,” the mutant precursor was still capable of using the Tat pathway, provided that the kinetically favored Sec pathway was blocked. These results show that the h-region of the TorA signal peptide is, in principle, sufficiently hydrophobic for Sec-dependent protein translocation, and therefore, the positively charged amino acid residues in the c-region represent a major determinant for Tat pathway specificity. Tat-dependent export of TorA-MalE was significantly slower in the presence of SecB than in its absence, showing that SecB can bind to this precursor despite the presence of the Sec avoidance signal in the c-region of the TorA signal peptide, strongly suggesting that the function of the Sec avoidance signal is not the prevention of SecB binding; rather, it must be exerted at a later step in the Sec pathway.
Growth Rate-Dependent Regulation of Medial FtsZ Ring Formation
Authors: Weart Richard B. , Levin Petra Anne
Published: April 2003

FtsZ is an essential cell division protein conserved throughout the bacteria and archaea. In response to an unknown cell cycle signal, FtsZ polymerizes into a ring that establishes the future division site. We conducted a series of experiments examining the link between growth rate, medial FtsZ ring formation, and the intracellular concentration of FtsZ in the gram-positive bacteriumBacillus subtilis.We found that, although the frequency of cells with FtsZ rings varies as much as threefold in a growth rate-dependent manner, the average intracellular concentration of FtsZ remains constant irrespective of doubling time. Additionally, expressingftsZsolely from a constitutive promoter, thereby eliminating normal transcriptional control, did not alter the growth rate regulation of medial FtsZ ring formation. Finally, our data indicate that overexpressing FtsZ does not dramatically increase the frequency of cells with medial FtsZ rings, suggesting that the mechanisms governing ring formation are refractile to increases in FtsZ concentration. These results support a model in which the timing of FtsZ assembly is governed primarily through cell cycle-dependent changes in FtsZ polymerization kinetics and not simply via oscillations in the intracellular concentration of FtsZ. Importantly, this model can be extended to the gram-negative bacteriumEscherichia coli. Our data show that, like those inB. subtilis, average FtsZ levels inE. coliare constant irrespective of doubling time.
Identification of the DNA Binding Sites of PerA, the Transcriptional Activator of thebfpandperOperons in EnteropathogenicEscherichia coli
Authors: Ibarra J. Antonio , Villalba Miryam I. , Puente José Luis
Published: April 2003

The bundle-forming pilus (BFP) is an important virulence factor for enteropathogenicEscherichia coli(EPEC). Genes involved in its biogenesis and regulation are tightly regulated by PerA (BfpT), a member of the AraC/XylS family of transcriptional regulators. The aim of this work was to purify PerA and determine its association withbfpAandperA(bfpT) regulatory regions by electrophoretic mobility shift and DNase I footprinting assays. PerA was purified as a maltose-binding protein (MBP) fusion, which was capable of complementingbfpAexpression and which was able to restore the localized adherence phenotype of an EPECperAmutant strain. Upstream ofbfpAandperA, MBP-PerA recognized with similar affinity asymmetric nucleotide sequences in which a 29-bp-long AT-rich consensus motif was identified. These DNA motifs share 66% identity and were previously shown, by deletion analysis, to be involved in the PerA-dependent expression of both genes. Interestingly, inperA, this motif spans the sequence between positions −75 and −47, approximately one helix turn upstream of the −35 promoter sequence, while inbfpA, it spans the sequence between positions −83 and −55, approximately two helix turns upstream from the promoter. An additional PerA binding site was identified at the 5′ end of thebfpAstructural gene, which was not required for its activation. Experiments with LexA-PerA fusions suggested that PerA acts as a monomer to activate the transcription of bothperAandbfpA, in contrast to what has been documented for other members of this family of transcriptional regulators.
Involvement of the
adc
Operon and Manganese Homeostasis in
Streptococcus gordonii
Biofilm Formation
Authors: Loo C. Y. , Mitrakul K. , Voss I. B. , Hughes C. V. , Ganeshkumar N.
Published: April 2003

Pioneer oral bacteria, including
Streptococcus gordonii
, initiate the formation of oral biofilms on tooth surfaces, which requires differential expression of genes that recognize unique environmental cues. An
S. gordonii
::Tn
917-lac
biofilm-defective mutant was isolated by using an in vitro biofilm formation assay. Subsequent inverse PCR and sequence analyses identified the transposon insertion to be near the 3′ end of an open reading frame (ORF) encoding a protein homologous to a
Streptococcus pneumoniae
repressor, AdcR. The
S. gordonii adc
operon, consisting of the four ORFs
adcR
,
adcC
,
adcB
, and
adcA
, is homologous to the
adc
operon of
S. pneumoniae
, which plays a role in zinc and/or manganese transport and genetic competence in
S. pneumoniae
. AdcR is a metal-dependent repressor protein containing a putative metal-binding site, AdcC contains a consensus-binding site for ATP, AdcB is a hydrophobic protein with seven hydrophobic membrane-spanning regions, and AdcA is a lipoprotein permease with a putative metal-binding site. The three proteins (AdcC through -A) are similar to those of the binding-lipoprotein-dependent transport system of gram-positive bacteria. Reverse transcriptase PCR confirmed that
adcRCBA
are cotranscribed as an operon in
S. gordonii
and that the transposon insertion in
S. gordonii adcR
::Tn
917-lac
had resulted in a polar mutation. Expression of
adcR
, measured by the β-galactosidase activity of the
adcR
::Tn
917-lac
mutant, was growth phase dependent and increased when the mutant was grown in media with high levels of manganese (>1 mM) and to a lesser extent in media with zinc, indicating that AdcR may be a regulator at high levels of extracellular manganese. A nonpolar inactivation of
adcR
generated by allelic replacement resulted in a biofilm- and competence-defective phenotype. The biofilm-defective phenotype observed suggests that AdcR is an active repressor when synthesized and acts at a distant site(s) on the chromosome. Thus, the
adc
operon is involved in manganese acquisition in
S. gordonii
and manganese homeostasis and appears to modulate sessile growth in this bacterium.
The YSIRK-G/S Motif of Staphylococcal Protein A and Its Role in Efficiency of Signal Peptide Processing
Authors: Bae Taeok , Schneewind Olaf
Published: April 2003

Many surface proteins of pathogenic gram-positive bacteria are linked to the cell wall envelope by a mechanism requiring a C-terminal sorting signal with an LPXTG motif. Surface proteins ofStreptococcus pneumoniaeharbor another motif, YSIRK-G/S, which is positioned within signal peptides. The signal peptides of some, but not all, of the 20 surface proteins ofStaphylococcus aureuscarry a YSIRK-G/S motif, whereas those of surface proteins ofListeria monocytogenesandBacillus anthracisdo not. To determine whether the YSIRK-G/S motif is required for the secretion or cell wall anchoring of surface proteins, we analyzed variants of staphylococcal protein A, an immunoglobulin binding protein with an LPXTG sorting signal. Deletion of the YSIR sequence or replacement of G or S significantly reduced the rate of signal peptide processing of protein A precursors. In contrast, cell wall anchoring or the functional display of protein A was not affected. The fusion of cell wall sorting signals to reporter proteins bearing N-terminal signal peptides with or without the YSIRK-G/S motif resulted in hybrid proteins that were anchored in a manner similar to that of wild-type protein A. The requirement of the YSIRK-G/S motif for efficient secretion implies the existence of a specialized mode of substrate recognition by the secretion pathway of gram-positive cocci. It seems, however, that this mechanism is not essential for surface protein anchoring to the cell wall envelope.
Species-Wide Variation in the
Escherichia coli
Flagellin (H-Antigen) Gene
Authors: Wang Lei , Rothemund Deborah , Curd Heather , Reeves Peter R.
Published: April 2003

Escherichia coli
is a clonal species. The best-understood components of its clonal variation are the flagellar (H) and polysaccharide (O) antigens, both well documented since the mid-1930s because of their use in serotyping. Flagellin is the protein subunit of the flagellum that carries H-antigen specificity. We show that 43 of the 54 H-antigen specificities of
E. coli
map to the flagellin gene at
fliC
and sequenced all 43 forms and confirmed specificity of each by cloning and expression. This is, to our knowledge, the first time that all known forms of such a highly polymorphic gene have been fully sequenced and characterized for any species. The established distinction between a highly variable central region and more conserved flanking regions is upheld. The sequences fall into two groups, one of which may be derived from the
fliC
gene of the
E. coli
/
Salmonella enterica
common ancestor, the other perhaps obtained by lateral transfer since species divergence. Comparison of sequences revealed that both horizontal DNA transfer and fixation of mutations under diversifying selection pressure contributed to polymorphism in this locus.
Substrate Specificity and Expression of Three 2,3-Dihydroxybiphenyl 1,2-Dioxygenases from
Rhodococcus globerulus
Strain P6
Authors: McKay David B. , Prucha Matthias , Reineke Walter , Timmis Kenneth N. , Pieper Dietmar H.
Published: April 2003

Rhodococcus globerulus
strain P6 contains at least three genes,
bphC1
,
bphC2
, and
bphC3
, coding for 2,3-dihydroxybiphenyl 1,2-dioxygenases; the latter two specify enzymes of the family of one-domain extradiol dioxygenases. In order to assess the importance of these different isoenzymes for the broad catabolic activity of this organism towards the degradation of polychlorinated biphenyls (PCBs), the capacities of recombinant enzymes expressed in
Escherichia coli
to transform different chlorosubstituted dihydroxybiphenyls formed by the action of
R. globerulus
P6 biphenyl dioxygenase and biphenyl 2,3-dihydrodiol dehydrogenase were determined. Whereas both BphC2 and BphC3 showed similar activities for 2,3-dihydroxybiphenyl and all monochlorinated 2,3-dihydroxybiphenyls, BphC1 exhibited only weak activity for 2′-chloro-2,3-dihydroxybiphenyl. More highly chlorinated 2′-chlorosubstituted 2,3-dihydroxybiphenyls were also transformed at high rates by BphC2 and BphC3 but not BphC1. In
R. globerulus
P6, BphC2 was constitutively expressed, BphC1 expression was induced during growth on biphenyl, and BphC3 was not expressed at significant levels under the experimental conditions. Although we cannot rule out the expression of BphC3 under certain environmental conditions, it seems that the contrasting substrate specificities of BphC1 and BphC2 contribute significantly to the versatile PCB-degrading phenotype of
R. globerulus
P6.
The Cell Wall of the Pathogenic Bacterium
Rhodococcus equi
Contains Two Channel-Forming Proteins with Different Properties
Authors: Rieβ Franziska G. , Elflein Marion , Benk Michael , Schiffler Bettina , Benz Roland , Garton Natalie , Sutcliffe Iain
Published: April 2003

We have identified in organic solvent extracts of whole cells of the gram-positive pathogen
Rhodococcus equi
two channel-forming proteins with different and complementary properties. The isolated proteins were able to increase the specific conductance of artificial lipid bilayer membranes made from phosphatidylcholine-phosphatidylserine mixtures by the formation of channels able to be permeated by ions. The channel-forming protein PorA
Req
(
R. equi
pore A) is characterized by the formation of cation-selective channels, which are voltage gated. PorA
Req
has a single-channel conductance of 4 nS in 1 M KCl and shows high permeability for positively charged solutes because of the presence of negative point charges. According to the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the protein has an apparent molecular mass of about 67 kDa. The analysis (using the effect of negative charges on channel conductance) of the concentration dependence of the single-channel conductance suggested that the diameter of the cell wall channel is about 2.0 nm. The second channel (formed by PorB
Req
[
R. equi
pore B]) shows a preferred movement of anions through the channel and is not voltage gated. This channel shows a single-channel conductance of 300 pS in 1 M KCl and is characterized by the presence of positive point charges in or near the channel mouth. Based on SDS-PAGE, the apparent molecular mass of the channel-forming protein is about 11 kDa. Channel-forming properties of the investigated cell wall porins were compared with those of others isolated from mycolic acid-containing actinomycetes. We present here the first report of a fully characterized anion-selective cell wall channel from a member of the order
Actinomycetales
.
STUDIES ON TWO-PHOTON ABSORPTION OF ANILINE USING THERMAL LENS EFFECT
Authors: KURIAN ACHAMMA , LEE S. THOMAS , UNNIKRISHNAN K. P. , GEORGE D. SAJAN , NAMPOORI V. P. N. , VALLABHAN C. P. G.
Published: April 2003

Two-photon absorption spectrum of aniline is recorded using thermal lens effect with optical parametric oscillator as the pump source. Studies show that the two-photon absorption spectrum observed corresponds to 1A1 → 1B2 transition of aniline.
POLYCYANURATE THIN FILM OPTICAL WAVEGUIDE FOR INTEGRATED OPTICS APPLICATIONS
Authors: SHARMA SUDHIR KUMAR , MISRA S. C. K. , TRIPATHI K. N.
Published: April 2003

This paper reports on the fabrication and characterization of polymer optical waveguide. The polymer films were used by dip coating technique. Various waveguide parameters such as refractive index, optical losses, thickness of guide has been reported. Polycyanurate synthesized as planar optical waveguide exhibits low optical loss (< 2 dB/cm) having refractive index 1.592 and excellent absorption spectra in the wavelength range (1540–1560 nm) which makes this polymer promising for integrated optical devices.
ANALYSIS OF POTENTIAL ENERGY IN BIREFRINGENT FIBER THROUGH UNDAMPED DUFFING OSCILLATOR EQUATION
Authors: PORSEZIAN K. , SENTHILNATHAN K.
Published: April 2003

In this paper, we consider the pulse propagation through the birefringent fiber with linear coupling effects. Using the Stokes parameter formalism and conserved densities, we construct the undamped Duffing oscillator equation from integro-differential equations. We also discuss the variation of potential well for different choices of physical parameters. From the linear stability analysis and numerical methods, we also discuss the stability, instability and bifurcation phenomenon in the birefringent fiber through Duffing oscillator type equation.
Aircraft drag reduction—a review
Authors: Bushnell D M
Published: April 2003

The paper summarizes the state of the art in aeronautical drag reduction across the speed range for the “conventional” drag components of viscous drag, drag due to lift and wave drag. It also describes several emerging drag-reduction approaches that are either active or reactive/interactive and the drag reduction potentially available from synergistic combinations of advanced configuration aerodynamics, viscous drag-reduction approaches, revolutionary structural concepts and propulsion integration.
Hydrodynamic support and dynamic response for an inner-piloted bearing cage
Authors: Ashmore D R , Williams E J , McWilliam S
Published: April 2003

Although many attempts have been made to model rolling-element bearings with inner-piloted cages, they all simplify the hydrodynamic cage-support mechanism. This can mean that some cage behaviour is inadequately explained, such as cage lap. This paper presents the development of a new three-dimensional analysis of the hydrodynamic support for an inner-piloted cage for a rolling-element bearing incorporating starved-film conditions. The solution of the generalized Reynolds equation along with a continuity equation leads to analytical expressions for the hydrodynamic forces. The equations of motion for the cage are then integrated numerically using the Newmark beta method to predict the cage response. The availability of analytical hydrodynamic force expressions means that the numerical integration process is computationally efficient. The influence of key parameters such as the level of lubrication and the angular velocity of the inner race are investigated.
Effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers
Authors: Anand R B , Rai L , Singh S N
Published: April 2003

The effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers (length-inlet diameter ratio, L/Di = 11:4) having an area ratio of 1.9 and centre-line length of 600 mm has been established. The experiments are carried out for three S-shaped circular diffusers having angles of turn of 15°/15°, 22.5°/22.5° and 30°/30°. Velocity, static pressure and total pressure distributions at different planes along the length of the diffusers are measured using a five-hole impact probe. The turbulence intensity distribution at the same planes is also measured using a normal hot-wire probe. The static pressure recovery coefficients for 15°/15°, 22.5°/22.5° and 30°/30° diffusers are evaluated as 0.45, 0.40 and 0.35 respectively, whereas the ideal static pressure recovery coefficient is 0.72. The low performance is attributed to the generation of secondary flows due to geometrical curvature and additional losses as a result of the high surface roughness (~0.5 mm) of the diffusers. The pressure recovery coefficient of these circular test diffusers is comparatively lower than that of an S-shaped rectangular diffuser of nearly the same area ratio, even with a larger turning angle (90°/90°), i.e. 0.53. The total pressure loss coefficient for all the diffusers is nearly the same and seems to be independent of the angle of turn. The flow distribution is more uniform at the exit for the higher angle of turn diffusers.
Desirable eigenstructure for good short-term helicopter handling qualities: The attitude command response case
Authors: Clarke T , Ensor J , Griffin S J
Published: April 2003

The eigenstructure necessary to achieve a good short-term attitude command response in a generic single-rotor helicopter is presented. It achieves appropriate mode decoupling and is consistent with the physical relationships between the state variables. This eigenstructure translates exactly into ideal transfer functions for use with a variety of control design methodologies. The paper discusses how such an eigenstructure is defined to satisfy the requirements of two important military rotorcraft specifications: US ADS 33 and UK DEF STAN 00970.
Hydrodesulfurization of 4,6-DMDBT in the High Boiling Fraction of Gas Oil
Authors: Choi Ki-Hyouk , Korai Yozo , Mochida Isao
Published: April 2003

A high boiling fraction of straight run gas oil, which contained 4,6-DMDBT by addition but free from dimethylbiphenyl and dimethylcyclohexylbenzene of its HDS products, was desulfurized over commercial catalysts to find principal products of 4,6-DMDBT. Thus, HDS of 4,6-DMDBT in the high boiling fraction of real feed was proved to proceed principally through hydrogenative route. During the HDS of the fraction, 4,6-DMDBT was found to be produced from trimethyldibenzothiophenes. This activity depended very much on the acidity of the catalyst.
Decomposition of Dichlorodifluoromethane with Simultaneous Halogen Fixation by Transition Metal Oxides Supported on Magnesium Oxide
Authors: Tamai Tsukasa , Inazu Koji , Aika Ken-ichi
Published: April 2003

CFC12 (CCl2F2) decomposition with simultaneous halogen fixation by MgO was significantly promoted by supporting transition metal oxides. Vanadium oxides were the most effective and over 80% of halogen was fixed as magnesium halides in 3.3 h (stoichiometric CFC12 feeding to MgO) at 723 K.
Electroreduction Behavior of Dinitrogen over Ruthenium Cathodic Catalyst
Authors: Zhang Shu-Yong , Zhang Xiu-Yun , Zhang Zuo-Shan , Kong Yan , Hua Shou-Nan
Published: April 2003

Dinitrogen was reduced electrochemically at ambient temperature and pressure in aqueous solution over ruthenium catalyst. It was found that the chemically deposited ruthenium loaded on active carbon was an effective catalyst with good activity and stability for nitrogen reduction. A peak with many shoulders corresponding to the reduction of dinitrogen to ammonia was first observed in the difference linear sweep voltammogram.
Solvothermal Synthesis of γ-LiV2O5 Nanorods as Cathode Material for Rechargeable Lithium Batteries
Authors: Xu Hai Yan , Wang Hao , Song Zhi Qiang , Wang Yao Wu , Zhang Yong Cai , Yan Hui
Published: April 2003

γ-LiV2O5 nanorods with diameters of 30–40 nm and lengths of 0.4–2 μm have been synthesized by a simple solvothermal method at 160 °C using ethanol as a solvent, which also serves as a reducing agent. The γ-LiV2O5/Li cell demonstrated an initial specific capacity of 259 mAh/g. After several initial cycling, the cell showed stabilized cycling behavior (199 mAh/g at the 20th cycle).
Home telemonitoring for patients with severe respiratory illness: the Italian experience
Authors: Maiolo Carmela , Mohamed Ehab I , Fiorani Cesare M , de Lorenzo Antonino
Published: April 2003

We investigated the feasibility of telemonitoring services for patients with severe respiratory illness. In the first phase of the study, patients were observed and treated using face-to-face medical visits for 12 months. In the second phase of the study, the patients were monitored at home for 12 months, during which time determinations of arterial oxygen saturation and heart rate were performed twice a week, and the data were automatically transmitted to the hospital's processing centre via a normal telephone line. Thirty patients on long-term oxygen therapy were enrolled in the study; 23 completed the 12 months of home telemonitoring. The numbers of hospital admissions and of acute home exacerbations during the telemonitoring phase of the study decreased by 50% and 55%, respectively, in comparison with the first phase. Estimates of hospitalization costs for the patients during the second phase were approximately 17% lower than those for the first phase. Patients were satisfied with the quality of the personal telemonitoring process in 96% of cases. We believe that telemedicine can enable the provision of high-quality home care for patients with severe respiratory illness.
Use of ISDN video-phones for clients receiving palliative and antenatal home care
Authors: Miyazaki Masako , Stuart Michelle , Liu Lili , Tell Sharon , Stewart Marianne
Published: April 2003

We examined the use of ISDN video-phones by health professionals and two types of home care clients: those receiving palliative care and those receiving antenatal care. In the palliative care group, there were four female clients and 15 health professionals; these clients on average had the video-phones at home for six weeks and made 12.5 calls per week. The antenatal care group consisted of six female clients and eight female registered nurses; these clients on average also had the video-phones at home for six weeks and made 12.5 calls per week. Exit interviews were conducted with three clients and eight staff in the palliative care group, and with six clients and three staff in the antenatal care group. Palliative care clients and their families commented that the visual feature of the phone enhanced the care that they received. In the antenatal group, the video-phone was used mainly for booking appointments and arranging home visits. In general, the technology was well received by clients and care providers.
A network-reactive model for distributed telemicroscopy
Authors: Lin Wei , Wilder Joseph , Grossman Seth , Foran David J
Published: April 2003

We have developed a network-reactive robotic telemicroscopy system that uses high-speed image processing and quality of service (QoS) feedback to maximize performance. In tests, four magnifications (4×, 10×, 40×, 60×) of a section stained with haematoxylin and eosin were used. Up to 25 clients, distributed across two Internet domains, accessed the server. When given control of the microscope, any of the clients could direct the microscope to change focus and objectives within 3 s and move the stage to any x-y position within 1 s. Transmission rates of 50-200 kbit/s were achieved for video (320 × 240 pixels at 24 bit/pixel). Performance varied according to the complexity of the images being transmitted. The 25 simultaneous users were supported without affecting the operation of the server and the system overhead was relatively small. The server's message-processing time and the network transmission delay amounted to 83 ms. The compression ratio of five previously stored video-sequences ranged from 336:1 to 1213:1. The underlying model for this system could serve a wide range of telemedicine and distance-learning applications.
Tele-education in child mental health for rural allied health workers
Authors: Fahey A , Day N A , Gelber H
Published: April 2003

We developed a tele-education programme in child mental health for rural allied health workers. The programme was delivered in two parts, each consisting of six sessions. Videoconferencing at 384 kbit/s was used. Satisfactory retention rates were maintained throughout. Participants consistently reported increases in knowledge and skills as a result of attending the programme. The project resulted in a high rate of reported changes to practice. An unanticipated outcome was the value placed on the opportunities for local networking provided by the project for participants. Videoconferencing can deliver effective professional development to allied health workers in child mental health.
The measurement of organizational justice in organizational change programmes: A reliability, validity and context‐sensitivity assessment
Authors: Paterson Janice M. , Green Andrea , Cary Jane
Published: April 2003

This study identified relevant content for standardized measures of organizational justice and evaluated the reliability, validity and context sensitivity of measures of procedural, interactional and distributive justice that assess the perceived fairness of organizational change programmes. Two organizations that were undergoing changes that differed in the severity and permanence of employee outcomes participated in the research. After refinement on the basis of test‐retest reliability and factor analysis, the procedural and interactional justice measures demonstrated good reliability and validity, but the equity‐based items that operationalized distributive justice performed poorly. The results offer some support for concerns over possible context‐sensitivity of justice perceptions and emphasize the need for a comprehensive set of standardized measures that can be customized to assess and compare justice perceptions in different organizational contexts. Directions for further research and measurement development are discussed.
Underemployment and relative deprivation among re‐employed executives
Authors: Feldman Daniel C. , Leana Carrie R. , Bolino Mark C.
Published: April 2003

Using a sample of 517 executives who lost their jobs as a result of downsizing, this study examined underemployment among managers in replacement jobs taken after their layoffs. Laid‐off executives who were re‐employed in jobs which paid less, were at lower levels of organizational hierarchies and which did not fully utilize their skills had consistently lower job attitudes. In addition, the results suggest that relative deprivation is an important mediator in explaining how underemployment leads to poorer psychological well‐being in those replacement jobs. The article concludes with directions for future research on underemployment and relative deprivation in the aftermath of layoffs.
The interface of cognitive and industrial, work and organizational psychology
Authors: Hodgkinson Gerard P.
Published: April 2003

This special issue brings together a collection of papers that variously integrate, extend and/or test new theory and research lying at the boundaries of the cognitive sciences and the field of industrial, work and organizational (IWO) psychology. Over the last two decades, the IWO psychology field in general has witnessed a dramatic upsurge in the development and testing of theories of work‐related behaviour and the design of interventions with a cognitive emphasis. In the related areas of engineering psychology and ergonomics, for example, researchers have devoted considerable attention to an analysis of the nature and significance of employees' mental models of complex operating systems in terms of their impact on system performance while in the area of selection and assessment, attribution theory and other work from the field of social cognition have increasingly informed the analysis of personnel selection interviews. Cognitive theory and research have also been applied in an attempt to better understand the underlying bases of appraisers' judgments in the appraisal of performance. In the area of training and development, conventional approaches to the analysis, design, and evaluation of interventions are being augmented, and in some cases openly challenged, by the application of cognitive constructs, theories, and principles. Much recent theory and research relating to the topics of employee relations and motivation, organizational development and change, teamwork, leadership, organizational culture and climate, negotiation, group decision‐making, stress, and personality and individual differences has also been decidedly cognitive in emphasis. This essay provides a selective overview of these developments, both in order to place in context the other contributions to this volume and in order to reflect more generally on the state of theory and research lying at the IWO‐cognitive psychology interface.
The ASPIRe model: Actualizing Social and Personal Identity Resources to enhance organizational outcomes
Authors: Haslam S. Alexander , Eggins Rachael A. , Reynolds Katherine J.
Published: April 2003

A growing body of research points to the contribution of social identity and self‐categorization processes to organizational social capital. In particular, this is because all facets of collective behaviour (e.g., trust, communication, leadership, productivity) are facilitated to the extent that individuals define themselves in terms of higher‐order social categories (i.e., as members of a common ingroup). However, very little work has sought to translate these social and cognitive insights into models of organizational practice. In an attempt to do this, the present paper outlines a four‐phase model for Actualizing Social and Personal Identity Resources (the ASPIRe model). Within a relevant organizational unit, an initial phase involves ascertaining which social identities employees use collectively to define themselves (AIRing). In intermediate phases, relevant subgroups and then the organizational unit as a whole develop goals that are relevant to those identities (Sub‐Casing and Super‐Casing). In a final phase, organizational planning and direction are informed by the outcomes of the previous two phases and by the new organic organizational identity they produce (ORGanizing). Points of contact with alternative models are identified and the model's potential to encourage sustainable productivity is discussed.
Comparing two attributional models of job performance in retail sales: A field study
Authors: Silvester Joanne , Patterson Fiona , Ferguson Eamonn
Published: April 2003

Research investigating attributional style and job performance among sales staff has been limited by its focus on specific sales roles: notably selling insurance by telephone. Important questions therefore remain regarding the mechanism by which attributions influence job performance in sales roles more generally. This paper describes a field study comparing two attributional models of job performance: (1) a learned helplessness (LH) model, and (2) an achievement motivation (AM) model. Managers' performance ratings were collected for 452 retail sales assistants who completed a job‐specific attribution questionnaire and a work‐satisfaction questionnaire. Results indicate that sales assistants who made more internalcontrollable attributions for positive outcomes received higher performance ratings (r =.20, p<.01) and were more satisfied in their work (r =.12, p< .05). The findings provide support for an AM model of job performance among retail sales assistants. They suggest that more successful sales assistants proactively manage their environment in order to create opportunities for successful interactions with customers.