bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sustaining Knowledge Transfer Through Leadership
Authors: Gifford Wendy , Davies Barbara , Edwards Nancy , Griffin Pat 
Published: December 2004

ABSTRACTThe delivery of efficient and high quality nursing care in today's health care environment requires that nurses utilize research evidence to guide their decision‐making in clinical practice. Best Practice Guidelines (BPGs) are an accessible link to research evidence and an effective tool for improving quality health care. Despite reported benefits and dissemination strategies, the transfer and uptake of guidelines does not always occur, and sustainability over time is seldom evaluated. Emerging evidence indicates that leadership plays a fundamental role in the transfer and sustained use of BPGs in clinical decision‐making. However, a clear understanding of effective nursing leadership to sustain knowledge transfer remains unclear and research is limited. Objective: To describe the evolving development of a conceptual framework for sustaining knowledge transfer of BPGs into nursing practice in Canadian health care settings. Methods: A critical review of the literature has been conducted. A model was developed to direct an inquiry about leadership characteristics and activities in 10 organizations that either sustained, partially sustained, or did not sustain practice guidelines 2 years after a pilot implementation initiative administrated by the Registered Nurses Association of Ontario Best Practice Guideline (RNAO‐BPG) Project. Findings: A conceptual framework has been developed to represent the key components of leadership and how these components are operationalized for knowledge transfer of BPGs into clinical practice. The model is an assimilation of the United Kingdom and North American literature and includes a pathway for personal attributes, defined skills, and knowledge repertoires that emerge from two domains of influence: cultural/clinical and political/organizational. Although the literature shows many similarities between leadership paradigms, some differences in discourse and approach were found. Implications: To create successful strategies to sustain practice innovations, we need to better understand how nursing leaders operate effectively within both clinical and organizational environments. This framework is the groundwork for conceptualizing nursing leadership as a vehicle to influence, shape, and sustain evidence‐based nursing practice.
Genes Involved in the Synthesis and Degradation of Matrix Polysaccharide in
Actinobacillus actinomycetemcomitans
and
Actinobacillus pleuropneumoniae
Biofilms
Authors: Kaplan Jeffrey B. , Velliyagounder Kabilan , Ragunath Chandran , Rohde Holger , Mack Dietrich , Knobloch Johannes K.-M. , Ramasubbu Narayanan 
Published: December 2004

ABSTRACT

Biofilms are composed of bacterial cells embedded in an extracellular polysaccharide matrix. A major component of the
Escherichia coli
biofilm matrix is PGA, a linear polymer of
N
-acetyl-
d
-glucosamine residues in β(1,6) linkage. PGA mediates intercellular adhesion and attachment of cells to abiotic surfaces. In this report, we present genetic and biochemical evidence that PGA is also a major matrix component of biofilms produced by the human periodontopathogen
Actinobacillus actinomycetemcomitans
and the porcine respiratory pathogen
Actinobacillus pleuropneumoniae
. We also show that PGA is a substrate for dispersin B, a biofilm-releasing glycosyl hydrolase produced by
A. actinomycetemcomitans
, and that an orthologous dispersin B enzyme is produced by
A. pleuropneumoniae
. We further show that
A. actinomycetemcomitans
PGA cross-reacts with antiserum raised against polysaccharide intercellular adhesin, a staphylococcal biofilm matrix polysaccharide that is genetically and structurally related to PGA. Our findings confirm that PGA functions as a biofilm matrix polysaccharide in phylogenetically diverse bacterial species and suggest that PGA may play a role in intercellular adhesion and cellular detachment and dispersal in
A. actinomycetemcomitans
and
A. pleuropneumoniae
biofilms.
Dynamics and Control of Biofilms of the Oligotrophic Bacterium
Caulobacter crescentus
Authors: Entcheva-Dimitrov Plamena , Spormann Alfred M. 
Published: December 2004

ABSTRACT

Caulobacter crescentus
is an oligotrophic α-proteobacterium with a complex cell cycle involving sessile-stalked and piliated, flagellated swarmer cells. Because the natural lifestyle of
C. crescentus
intrinsically involves a surface-associated, sessile state, we investigated the dynamics and control of
C. crescentus
biofilms developing on glass surfaces in a hydrodynamic system. In contrast to biofilms of the well-studied
Pseudomonas aeruginosa
,
Escherichia coli
, and
Vibrio cholerae
,
C. crescentus
CB15 cells form biphasic biofilms, consisting predominantly of a cell monolayer biofilm and a biofilm containing densely packed, mushroom-shaped structures. Based on comparisons between the
C. crescentus
strain CB15 wild type and its holdfast (
hfsA
; ΔCC0095), pili (Δ
pilA-cpaF
::Ω
aac3
), motility (
motA
), flagellum (
flgH
) mutants, and a double mutant lacking holdfast and flagellum (
hfsA
;
flgH
), a model for biofilm formation in
C. crescentus
is proposed. For both biofilm forms, the holdfast structure at the tip of a stalked cell is crucial for mediating the initial attachment. Swimming motility by means of the single polar flagellum enhances initial attachment and enables progeny swarmer cells to escape from the monolayer biofilm. The flagellum structure also contributes to maintaining the mushroom structure. Type IV pili enhance but are not absolutely required for the initial adhesion phase. However, pili are essential for forming and maintaining the well-defined three-dimensional mushroom-shaped biofilm. The involvement of pili in mushroom architecture is a novel function for type IV pili in
C. crescentus
. These unique biofilm features demonstrate a spatial diversification of the
C. crescentus
population into a sessile, “stem cell”-like subpopulation (monolayer biofilm), which generates progeny cells capable of exploring the aqueous, oligotrophic environment by swimming motility and a subpopulation accumulating in large mushroom structures.
Conserved Repeat Motifs and Glucan Binding by Glucansucrases of Oral Streptococci and
Leuconostoc mesenteroides
Authors: Shah Deepan S. H. , Joucla Gilles , Remaud-Simeon Magali , Russell Roy R. B. 
Published: December 2004

ABSTRACT

Glucansucrases of oral streptococci and
Leuconostoc mesenteroides
have a common pattern of structural organization and characteristically contain a domain with a series of tandem amino acid repeats in which certain residues are highly conserved, particularly aromatic amino acids and glycine. In some glucosyltransferases (GTFs) the repeat region has been identified as a glucan binding domain (GBD). Such GBDs are also found in several glucan binding proteins (GBP) of oral streptococci that do not have glucansucrase activity. Alignment of the amino acid sequences of 20 glucansucrases and GBP showed the widespread conservation of the 33-residue A repeat first identified in GtfI of
Streptococcus downei
. Site-directed mutagenesis of individual highly conserved residues in recombinant GBD of GtfI demonstrated the importance of the first tryptophan and the tyrosine-phenylalanine pair in the binding of dextran, as well as the essential contribution of a basic residue (arginine or lysine). A microplate binding assay was developed to measure the binding affinity of recombinant GBDs. GBD of GtfI was shown to be capable of binding glucans with predominantly α-1,3 or α-1,6 links, as well as alternating α-1,3 and α-1,6 links (alternan). Western blot experiments using biotinylated dextran or alternan as probes demonstrated a difference between the binding of streptococcal GTF and GBP and that of
Leuconostoc
glucansucrases. Experimental data and bioinformatics analysis showed that the A repeat motif is distinct from the 20-residue CW motif, which also has conserved aromatic amino acids and glycine and which occurs in the choline-binding proteins of
Streptococcus pneumoniae
and other organisms.
Bacillus subtilisOperon Encoding a Membrane Receptor for Bacteriophage SPP1
Authors: São-José Carlos , Baptista Catarina , Santos Mário A. 
Published: December 2004

ABSTRACTThe results reported here have identifiedyueBas the essential gene involved in irreversible binding of bacteriophage SPP1 toBacillus subtilis. First, a deletion in an SPP1-resistant (pha-2) strain, covering most of theyueBgene, could be complemented by a xylose-inducible copy ofyueBinserted atamyE. Second, disruption ofyueBby insertion of a pMutin4 derivative resulted in a phage resistance phenotype regardless of the presence or absence of IPTG (isopropyl-β-d-thiogalactopyranoside). YueB homologues are widely distributed in gram-positive bacteria. The protein Pip, which also serves as a phage receptor inLactococcus lactis, belongs to the same family.yueBencodes a membrane protein of ∼120 kDa, detected in immunoblots together with smaller forms that may be processed products arising from cleavage of its long extracellular domain. Insertional inactivation ofyueBand the surrounding genes indicated thatyueBis part of an operon which includes at least the upstream genesyukE,yukD,yukC, andyukBA. Disruption of each of the genes in the operon allowed efficient irreversible adsorption, provided thatyueBexpression was retained. Under these conditions, however, smaller plaques were produced, a phenotype which was particularly noticeable inyukEmutant strains. Interestingly, such reduction in plaque size was not correlated with a decreased adsorption rate. Overall, these results provide the first demonstration of a membrane-bound protein acting as a phage receptor inB. subtilisand suggest an additional involvement of theyukEoperon in a step subsequent to irreversible adsorption.
Involvement of SirABC in Iron-Siderophore Import inStaphylococcus aureus
Authors: Dale Suzanne E. , Sebulsky M. Tom , Heinrichs David E. 
Published: December 2004

ABSTRACTStaphylococcus aureusSirA was previously identified as a lipoprotein, and SirB and SirC are thought to encode the transmembrane domains of an ABC transporter. Sir proteins show similarity to iron-siderophore transporters in several bacteria. Here, we show that the iron-regulatedsirABCoperon is divergently transcribed from thesbnoperon that encodes enzymes involved in the synthesis of staphylobactin, a recently described siderophore produced byS. aureus. Mutation of eithersirAorsirBincreased the resistance of iron-starvedS. aureusto streptonigrin and resulted in compromised growth in iron-restricted, but not iron-rich, media. We also demonstrated thatsirAandsirBmutants are compromised in the ability to transport iron complexed to staphylobactin but are not compromised for uptake of other iron complexes, such as ferric hydroxamates, ferric enterobactin, or ferric citrate. SirA- and SirB-deficientS. aureus, however, retain the ability to produce staphylobactin. Moreover, we found that transcription from thesbnoperon was increased, relative to the wild type, in bothsirAandsirBknockout strains, likely in response to an increased level of iron starvation in these cells. These results provide evidence of a role for these proteins in iron import inS. aureusand for full fitness of the bacterium in iron-restricted environments and demonstrate a function forS. aureusgenes encoding proteins involved in the transport of an endogenously produced siderophore.
Gene
ytkD
of
Bacillus subtilis
Encodes an Atypical Nucleoside Triphosphatase Member of the Nudix Hydrolase Superfamily
Authors: Xu WenLian , Jones Candice R. , Dunn Christopher A. , Bessman Maurice J. 
Published: December 2004

ABSTRACT

Gene
ytkD
of
Bacillus subtilis
, a member of the Nudix hydrolase superfamily, has been cloned and expressed in
Escherichia coli
. The purified protein has been characterized as a nucleoside triphosphatase active on all of the canonical ribo- and deoxyribonucleoside triphosphates. Whereas all other nucleoside triphosphatase members of the superfamily release inorganic pyrophosphate and the cognate nucleoside monophosphate, YtkD hydrolyses nucleoside triphosphates in a stepwise fashion through the diphosphate to the monophosphate, releasing two molecules of inorganic orthophosphate. Contrary to a previous report, our enzymological and genetic studies indicate that
ytkD
is not an orthologue of
E. coli mutT
.
Effect of Mild Acid on Gene Expression in
Staphylococcus aureus
Authors: Weinrick Brian , Dunman Paul M. , McAleese Fionnuala , Murphy Ellen , Projan Steven J. , Fang Yuan , Novick Richard P. 
Published: December 2004

ABSTRACT
During staphylococcal growth in glucose-supplemented medium, the pH of a culture starting near neutrality typically decreases by about 2 units due to the fermentation of glucose. Many species can comfortably tolerate the resulting mildly acidic conditions (pH, ∼5.5) by mounting a cellular response, which serves to defend the intracellular pH and, in principle, to modify gene expression for optimal performance in a mildly acidic infection site. In this report, we show that changes in staphylococcal gene expression formerly thought to represent a glucose effect are largely the result of declining pH. We examine the cellular response to mild acid by microarray analysis and define the affected gene set as the mild acid stimulon. Many of the genes encoding extracellular virulence factors are affected, as are genes involved in regulation of virulence factor gene expression, transport of sugars and peptides, intermediary metabolism, and pH homeostasis. Key results are verified by gene fusion and Northern blot hybridization analyses. The results point to, but do not define, possible regulatory pathways by which the organism senses and responds to a pH stimulus.
Terminal Oxidases Are Essential To Bypass the Requirement for ResD for Full Pho Induction in
Bacillus subtilis
Authors: Schau Matthew , Eldakak Amr , Hulett F. Marion 
Published: December 2004

ABSTRACT

The
Bacillus subtilis
Pho signal transduction network, which regulates the cellular response to phosphate starvation, integrates the activity of three signal transduction systems to regulate the level of the Pho response. This signal transduction network includes a positive feedback loop between the PhoP/PhoR and ResD/ResE two-component systems. Within this network, ResD is responsible for 80% of the Pho response. To date, the role of ResD in the generation of the Pho response has not been understood. Expression of two terminal oxidases requires ResD function, and expression of at least one terminal oxidase is needed for the wild-type Pho response. Previously, our investigators have shown that strains bearing mutations in
resD
are impaired for growth and acquire secondary mutations which compensate for the loss of the
a
-type terminal oxidases by allowing production of cytochrome
bd
. We report here that the expression of cytochrome
bd
in a Δ
resDE
background is sufficient to compensate for the loss of ResD for full Pho induction. A
ctaA
mutant strain, deficient in the production of heme A, has the same Pho induction phenotype as a Δ
resDE
strain. This demonstrates that the production of
a
-type terminal oxidases is the basis for the role of ResD in Pho induction. Terminal oxidases affect the redox state of the quinone pool. Reduced quinones inhibit PhoR autophosphorylation in vitro, consistent with a requirement for terminal oxidases for full Pho induction in vivo.
Cold Adaptation in the Antarctic Archaeon
Methanococcoides burtonii
Involves Membrane Lipid Unsaturation
Authors: Nichols David S. , Miller Matthew R. , Davies Noel W. , Goodchild Amber , Raftery Mark , Cavicchioli Ricardo 
Published: December 2004

ABSTRACT

Direct analysis of membrane lipids by liquid chromatography-electrospray mass spectrometry was used to demonstrate the role of unsaturation in ether lipids in the adaptation of
Methanococcoides burtonii
to low temperature. A proteomics approach using two-dimensional liquid chromatography-mass spectrometry was used to identify enzymes involved in lipid biosynthesis, and a pathway for lipid biosynthesis was reconstructed from the
M. burtonii
draft genome sequence. The major phospholipids were archaeol phosphatidylglycerol, archaeol phosphatidylinositol, hydroxyarchaeol phosphatidylglycerol, and hydroxyarchaeol phosphatidylinositol. All phospholipid classes contained a series of unsaturated analogues, with the degree of unsaturation dependent on phospholipid class. The proportion of unsaturated lipids from cells grown at 4°C was significantly higher than for cells grown at 23°C. 3-Hydroxy-3-methylglutaryl coenzyme A synthase, farnesyl diphosphate synthase, and geranylgeranyl diphosphate synthase were identified in the expressed proteome, and most genes involved in the mevalonate pathway and processes leading to the formation of phosphatidylinositol and phosphatidylglycerol were identified in the genome sequence. In addition,
M. burtonii
encodes CDP-inositol and CDP-glycerol transferases and a number of homologs of the plant geranylgeranyl reductase. It therefore appears that the unsaturation of lipids may be due to incomplete reduction of an archaeol precursor rather than to a desaturase mechanism. This study shows that cold adaptation in
M. burtonii
involves specific changes in membrane lipid unsaturation. It also demonstrates that global methods of analysis for lipids and proteomics linked to a draft genome sequence can be effectively combined to infer specific mechanisms of key biological processes.
The F-ATPase Operon Promoter of
Streptococcus mutans
Is Transcriptionally Regulated in Response to External pH
Authors: Kuhnert Wendi L. , Zheng Guolu , Faustoferri Roberta C. , Quivey Robert G. 
Published: December 2004

ABSTRACT

Streptococcus mutans
F-ATPase, the major component of the acid-adaptive response of the organism, is transcriptionally upregulated at low pH. Fusions of the F-ATPase promoter to chloramphenicol acetyltransferase indicated that pH-dependent expression is still observed with a short promoter that contains a domain conserved between streptococcal ATPase operons.
Influence of
l
-Leucine and
l
-Alanine on Lrp Regulation of
foo
, Coding for F165
1
, a Pap Homologue
Authors: Berthiaume Frédéric , Crost Cécile , Labrie Vincent , Martin Christine , Newman Elaine B. , Harel Josée 
Published: December 2004

ABSTRACT

The
foo
operon encodes F165
1
fimbriae that belong to the P-regulatory family and are synthesized by septicemic
Escherichia coli
. Using an Lrp-deficient host and the
lrp
gene cloned under the arabinose pBAD promoter, we demonstrated that
foo
was transcribed proportionally to the amount of Lrp synthesized.
l
-Leucine and
l
-alanine decreased drastically the steady-state transcription of
foo
and modified phase variation, independently of the presence of FooI. Specific mutations in the C-terminal region of Lrp reduced or abolished the repressive effect of these amino acids, indicating that they modulate F165
1
by affecting Lrp.
Law and Custom in the Popular Legal Culture of North Africa
Authors: Rosen Lawrence 
Published: December 2004

AbstractFocusing on a series of instances from the Islamic courts of North Africa, the present article argues that custom does not stand apart from the sacred law but is seen by its adherents as itself Islamic and hence indissolubly linked to Islamic law. Local practice and universalizing principles of the sharīʿa thus merge in popular conceptualizations. Legal officials also share in the recognition of custom as part of the shariʾa, thus contributing to the overall legitimacy of the sharīʿa and to its capacity to respond to changing circumstances.
Barnabas 4.6b: the Exegetical Implications of a Textual Problem
Authors: Rhodes James 
Published: December 2004

AbstractAmong early Christian writings the Epistle of Barnabas is remarkable for the claim that Israel lost its covenant forever at Sinai because of its worship of the golden calf. What is less clear is whether Barnabas's interest in this event is driven primarily by polemical, paraenetic, or abstract theological concerns. Contributing to this uncertainty is a notorious text-critical problem at Barn. 4.6b where the author first raises the issue of Israel's debacle at Sinai. Although commentators have shown a pronounced preference for the reading preserved by the Latin version of Barnabas, this article concludes that the deference shown to the Latin reading is unwarranted. The author postulates a conservative emendation of the Greek text as superior to the Latin reading on both transcriptional and exegetical grounds.
Effect of Erucic Acid Percentage on Slip Properties of Erucamide
Authors: Walp Leonard , Tomlinson Harry 
Published: December 2004

Erucamide is a fatty acid amide most frequently used to reduce the coefficient of friction (increase slip) of polyolefin films. The erucic acid content of commercial erucamides varies from 80 to 94%. A project has been initiated to determine the effect, if any, that this variation has on slip properties. The performance of erucamide is measured in: • three different butene copolymer linear low-density polyethylenes (LLDPEs) • a hexene copolymer LLDPE • three different low-density polyethylenes (LDPE) Slip is measured on a 1.3 mil blown film. Varying the percentage of erucic acid in erucamide between 80 and 93% did not affect the coefficient of friction in the polymers tested.
The acoustic emission technique in orthopaedics - a review
Authors: Browne M , Roques A , Taylor A 
Published: December 2004

Traditionally, orthopaedic research has focused upon the assessment of individual components in an implanted construct. A great deal of research has investigated the durability of the metallic stem, even though this is the most robust component in the implanted system. Standards have been developed for the structural assessment of the implant and even the bone cement which holds the implant in place in the bone. However, the construct as a whole, and its short- and long-term structural integrity, are rarely assessed, and few methods have been established to monitor and predict the mechanisms leading to failure. These are necessary to ensure that any new implants entering the market will perform satisfactorily and prevent premature revision surgery. The acoustic emission (AE) technique offers the capability of monitoring structural degradation passively and in real time, and can distinguish failure mechanisms and their location through the analysis of AE parameters. In the present paper, the use of acoustic emission in orthopaedics, in particular for the evaluation of hip replacement constructs, is reviewed. Following this, three case studies undertaken at the University of Southampton are presented, in which acoustic emission on-line monitoring has been used to evaluate the performance of simulated artificial hip replacement constructs and their constituents during static and fatigue testing. In Case Study 1, the fatigue behaviour of bone cement is characterized; in Case Study 2, the residual stresses induced in the construct as a result of bone cement cure are investigated; in Case Study 3, the mechanisms leading to failure of a carbon fibre reinforced plastic hip stem during fatigue testing are characterized.