bluuebunny/crossref_metadata_2025_split huggingface dataset:
Team‐Level Antecedents of Individuals' Knowledge Networks*
Authors: Hoegl Martin , Parboteeah K. Praveen , Munson Charles L. 
Published: December 2003

ABSTRACTIndividuals' knowledge networks are widely considered to contribute substantially to the effectiveness and efficiency of organizations. While the positive effects of knowledge networks as a primary driver of social capital have recently received considerable research attention, potential determinants of individuals' network building have not yet been adequately addressed. In this study, we investigate how certain team‐level properties affect team members' development of knowledge networks through the course of a team project. Using data from 430 team leaders and team members pertaining to 145 software development projects, we test cross‐level hypotheses using hierarchical linear modeling (HLM). The results indicate that the team's perception of the organizational knowledge‐sharing climate, the team's networking preference, and the team's perceived importance of networking for project success positively affect individuals' network building. Furthermore, a team's perception of the adequacy of its technical competency and a team's perception of the adequacy of its material resources inhibit team members' individual network development. Theoretical and managerial implications are discussed.
The Effect of Team Leader Characteristics on Learning, Knowledge Application, and Performance of Cross‐Functional New Product Development Teams
Authors: Sarin Shikhar , McDermott Christopher 
Published: December 2003

ABSTRACTThis study examines how leadership characteristics in new product development teams affect the learning, knowledge application, and subsequently the performance of these teams. Using data from a study of 229 members from 52 high‐tech new product projects, we empirically demonstrate that team learning has a strong positive effect on the innovativeness and speed to market of the new products. Moreover, a democratic leadership style, initiation of goal structure by the team leader, and his or her position within the organization were positively related to team learning. Managerial implications of these results are discussed.
Modeling Network Latency and Parallel Processing in Distributed Database Design
Authors: Johansson Jesper M. , March Salvatore T. , Naumann J. David 
Published: December 2003

ABSTRACTThe design of responsive distributed database systems is a key concern for information systems managers. In high bandwidth networks latency and local processing are the most significant factors in query and update response time. Parallel processing can be used to minimize their effects, particularly if it is considered at design time. It is the judicious replication and placement of data within a network that enable parallelism to be effectively used. However, latency and parallel processing have largely been ignored in previous distributed database design approaches. We present a comprehensive approach to distributed database design that develops efficient combinations of data allocation and query processing strategies that take full advantage of parallelism. We use a genetic algorithm to enable the simultaneous optimization of data allocation and query processing strategies. We demonstrate that ignoring the effects of latency and parallelism at design time can result in the selection of unresponsive distributed database designs.
Strategic Decisions of New Technology Adoption under Asymmetric Information: A Game‐Theoretic Model*
Authors: Zhu Kevin , Weyant John P. 
Published: December 2003

ABSTRACTIn this paper we explore strategic decision making in new technology adoption by using economic analysis. We show how asymmetric information affects firms' decisions to adopt the technology. We do so in a two‐stage game‐theoretic model where the first‐stage investment results in the acquisition of a new technology that, in the second stage, may give the firm a competitive advantage in the product market. We compare two information structures under which two competing firms have asymmetric information about the future performance (i.e., postadoption costs) of the new technology. We find that equilibrium strategies under asymmetric information are quite different from those under symmetric information. Information asymmetry leads to different incentives and strategic behaviors in the technology adoption game. In contrast to conventional wisdom, our model shows that market uncertainty may actually induce firms to act more aggressively under certain conditions. We also show that having better information is not always a good thing. These results illustrate a key departure from established decision theory.
A Note on Interpersonal and Communication Skills for IS Professionals: Evidence of Positive Influence
Authors: Jiang James J. , Klein Gary , Slyke Craig Van , Cheney Paul 
Published: December 2003

ABSTRACTA recent article by Byrd and Turner (2001) reported that interpersonal skills on the part of information systems personnel had a negative influence on the success of systems as measured by competitive advantage. Several reasons were forwarded to account for this unexpected result, including lack of richness in the measure of these skills, the use of strategic success measures, the true complexity of interpersonal relations within an organization, and the sample of CIOs who may have a bias in favor of technical skills. We address these concerns by incorporating a set of communication skills into the interpersonal skills set, sampling users for a different set of stakeholders, and employing a more complex model based on theories of expectation. The results indicate that the impacts of interpersonal skills on system success is not a simple function of the perceived level of the IS staff's skill proficiency but is also determined by the understood expectations of skill requirements.
Why Total Quality Management Programs Do Not Persist: The Role of Management Quality and Implications for Leading a TQM Transformation*
Authors: Beer Michael 
Published: December 2003

ABSTRACTTop‐down total quality management (TQM) programs often fail to create deep and sustained change in organizations. They become a fad soon replaced by another fad. Failure to institutionalize TQM can be attributed to a gap between top management's rhetoric about their intentions for TQM and the reality of implementation in various subunits of the organization. The gap varies from subunit to subunit due to the quality of management in each. By quality of management is meant the capacity of senior team to (1) develop commitment to the new TQM direction and behave and make decisions that are consistent with it, (2) develop the cross‐functional mechanisms, leadership skills, and team culture needed for TQM implementation, and (3) create a climate of open dialogues about progress in the TQM transformation that will enable learning and further change. The TQM transformations will persist only if top management requires and ultimately institutionalizes an honest organizational‐wide conversation that surfaces valid data about the quality of management in each subunit of the firm and leads to changes in management quality or replacement of managers.
The Preferred Substrate for RecA-Mediated Cleavage of Bacteriophage 434 Repressor Is the DNA-Bound Dimer
Authors: Pawlowski David R. , Koudelka Gerald B. 
Published: December 2003

ABSTRACT
Induction of a lysogen of a lambdoid bacteriophage usually involves RecA-stimulated autoproteolysis of the bacteriophage repressor protein. Previous work on the phage repressors showed that the monomeric form of the protein is the target of RecA. Our previous work indicated that in the case of bacteriophage 434, virtually none of the repressor is present as a monomer in vivo. Hence, if the repressor in a lysogen is present as a dimer, how can RecA-stimulated autoproteolysis play a role in bacteriophage induction? We examined this question by determining the rate of RecA-stimulated 434 repressor cleavage as a function of repressor concentration and added DNA. Our results show that binding of 434 repressor to a specific DNA binding site dramatically increases the velocity of repressor autocleavage compared to the velocity of cleavage of the monomer and concentration-induced dimer. DNA binding-deficient hemidimers formed between the intact repressor and its C-terminal domain fragment have a lower rate of cleavage than DNA-bound dimers. These results show that the DNA-bound 434 repressor dimer, which is the form of the repressor that is required for its transcriptional regulatory functions, is the preferred form for RecA-stimulated autocleavage. We also show that the rate of repressor autocleavage is influenced by the sequence of the bound DNA. Kinetic analysis of the autocleavage reaction indicated that the DNA sequence influences the velocity of 434 repressor autocleavage by affecting the affinity of the repressor-DNA complex for RecA, not the chemical cleavage step. Regardless of the mechanism, the finding that the presence and precise sequence of DNA modulate the autocleavage reaction shows that DNA allosterically affects the function of 434 repressor.
Genomic Interrogation of the Dassie Bacillus Reveals It as a Unique RD1 Mutant within the
Mycobacterium tuberculosis
Complex
Authors: Mostowy Serge , Cousins Debby , Behr Marcel A. 
Published: December 2003

ABSTRACT

Despite their remarkable genetic homology, members of the
Mycobacterium tuberculosis
complex express very different phenotypes, most notably in their spectra of clinical presentation. For example,
M. tuberculosis
is regarded as pathogenic to humans, whereas members having deleted RD1, such as
Mycobacterium microti
and
Mycobacterium bovis
BCG, are not. The dassie bacillus, an infrequent variant of the
M. tuberculosis
complex characterized as being most similar to
M. microti
, is the causative agent of tuberculosis (TB) in the dassie (
Procavia capensis
). Intriguingly, the dassie bacillus is not pathogenic to rabbits or guinea pigs and has never been documented to infect humans. Although it was identified more than a half-century ago, the reasons behind its attenuation are unknown. Because large sequence polymorphisms have presented themselves as the most obvious genomic distinction among members of the
M. tuberculosis
complex, the DNA content of the dassie bacillus was interrogated by Affymetrix GeneChip to identify regions that are absent from it but present in
M. tuberculosis
H37Rv. Comparison has led to the identification of nine regions of difference (RD), five of which are shared with
M. microti
(RDs 3, 7, 8, 9, and 10). Although the dassie bacillus does not share the other documented deletions in
M. microti
(RD1
mic
, RD5
mic
, MID1, MID2, and MID3), it has endured unique deletions in the regions of RD1, RD5, N-RD25, and Rv3081-Rv3082c (
virS
). RD1
das
, affecting only Rv3874-Rv3877, is the smallest natural deletion of the RD1 region uncovered and points to genes within this region that are likely implicated in virulence. Newfound deletions from the dassie bacillus are discussed in relation to their evolutionary and biological significance.
Natural Selection and Evolution of Streptococcal Virulence Genes Involved in Tissue-Specific Adaptations
Authors: Kalia Awdhesh , Bessen Debra E. 
Published: December 2003

ABSTRACTThe molecular mechanisms underlying niche adaptation in bacteria are not fully understood. Primary infection by the pathogen group A streptococcus (GAS) takes place at either the throat or the skin of its human host, and GAS strains differ in tissue site preference. Many skin-tropic strains bind host plasminogen via the plasminogen-binding group A streptococcal M protein (PAM) present on the cell surface; inactivation of genes encoding either PAM or streptokinase (a plasminogen activator) leads to loss of virulence at the skin. Unlike PAM, which is present in only a subset of GAS strains, the gene encoding streptokinase (ska) is present in all GAS isolates. In this study, the evolution of the virulence genes known to be involved in skin infection was examined. Most genetic diversity withinskagenes was localized to a region encoding the plasminogen-docking domain (β-domain). The gene encoding PAM displayed strong linkage disequilibrium (P≪ 0.01) with a distinct phylogenetic cluster of theskaβ-domain-encoding region. Yet,skaalleles of distant taxa showed a history of intragenic recombination, and high intrinsic levels of recombination were found among GAS strains having different tissue tropisms. The data suggest that tissue-specific adaptations arise from epistatic coselection of bacterial virulence genes. Additional analysis ofskagenes showed that ∼4% of the codons underwent strong diversifying selection. Horizontal acquisition of oneskalineage from a commensalStreptococcusdonor species was also evident. Together, the data suggest that new phenotypes can be acquired through interspecies recombination between orthologous genes, while constrained functions can be preserved; in this way, orthologous genes may provide a rich and ready source for new phenotypes and thereby play a facilitating role in the emergence of new niche adaptations in bacteria.
Ruminococcus albus
8 Mutants Defective in Cellulose Degradation Are Deficient in Two Processive Endocellulases, Cel48A and Cel9B, Both of Which Possess a Novel Modular Architecture
Authors: Devillard Estelle , Goodheart Dara B. , Karnati Sanjay K. R. , Bayer Edward A. , Lamed Raphael , Miron Joshua , Nelson Karen E. , Morrison Mark 
Published: December 2003

ABSTRACT

The cellulolytic bacterium
Ruminococcus albus
8 adheres tightly to cellulose, but the molecular biology underpinning this process is not well characterized. Subtractive enrichment procedures were used to isolate mutants of
R. albus
8 that are defective in adhesion to cellulose. Adhesion of the mutant strains was reduced 50% compared to that observed with the wild-type strain, and cellulose solubilization was also shown to be slower in these mutant strains, suggesting that bacterial adhesion and cellulose solubilization are inextricably linked. Two-dimensional polyacrylamide gel electrophoresis showed that all three mutants studied were impaired in the production of two high-molecular-mass, cell-bound polypeptides when they were cultured with either cellobiose or cellulose. The identities of these proteins were determined by a combination of mass spectrometry methods and genome sequence data for
R. albus
8. One of the polypeptides is a family 9 glycoside hydrolase (Cel9B), and the other is a family 48 glycoside hydrolase (Cel48A). Both Cel9B and Cel48A possess a modular architecture, Cel9B possesses features characteristic of the B
2
(or theme D) group of family 9 glycoside hydrolases, and Cel48A is structurally similar to the processive endocellulases CelF and CelS from
Clostridium cellulolyticum
and
Clostridium thermocellum
, respectively. Both Cel9B and Cel48A could be recovered by cellulose affinity procedures, but neither Cel9B nor Cel48A contains a dockerin, suggesting that these polypeptides are retained on the bacterial cell surface, and recovery by cellulose affinity procedures did not involve a clostridium-like cellulosome complex. Instead, both proteins possess a single copy of a novel X module with an unknown function at the C terminus. Such X modules are also present in several other
R. albus
glycoside hydrolases and are phylogentically distinct from the fibronectin III-like and X modules identified so far in other cellulolytic bacteria.
In
Pseudomonas syringae
pv. phaseolicola, Expression of the
argK
Gene, Encoding the Phaseolotoxin-Resistant Ornithine Carbamoyltransferase, Is Regulated Indirectly by Temperature and Directly by a Precursor Resembling Carbamoylphosphate
Authors: López-López Karina , Hernández-Flores José Luis , Cruz-Aguilar Marisa , Alvarez-Morales Ariel 
Published: December 2003

ABSTRACT

Pseudomonas syringae
pv. phaseolicola synthesizes a non-host-specific toxin, phaseolotoxin, and also synthesizes a phaseolotoxin-resistant ornithine carbamoyltransferase (ROCT) to protect itself from its own toxin. ROCT is encoded by
argK
, which is expressed coordinately with phaseolotoxin synthesis at 18°C. To investigate the regulatory mechanisms of this system, null mutants were constructed for
argK
,
argF
(encoding the phaseolotoxin-sensitive OCTase [SOCT]), and
amtA
(encoding an amidinotransferase involved in phaseolotoxin synthesis). The
argF
mutant did not exhibit arginine auxotrophy when grown in M9 medium at 28°C, because under this condition SOCT was replaced by ROCT. This loss of thermoregulation of
argK
was apparently caused by accumulation of carbamoylphosphate, one of the substrates of SOCT. Carbamoylphosphate, which has a structure similar to that of the inorganic moiety of phaseolotoxin, was used in induction assays with wild-type
P. syringae
pv. phaseolicola and was shown to be able to induce
argK
expression in M9 medium at 28°C. These results indicate that
argK
expression is independent of temperature and is regulated directly by a compound resembling the inorganic moiety of phaseolotoxin.
Esp-Independent Biofilm Formation by
Enterococcus faecalis
Authors: Kristich Christopher J. , Li Yung-Hua , Cvitkovitch Dennis G. , Dunny Gary M. 
Published: December 2003

ABSTRACT

Enterococcus faecalis
is a gram-positive opportunistic pathogen known to form biofilms in vitro. In addition, this organism is often isolated from biofilms on the surfaces of various indwelling medical devices. However, the molecular mechanisms regulating biofilm formation in these clinical isolates are largely unknown. Recent work has suggested that a specific cell surface protein (Esp) of
E. faecalis
is critical for biofilm formation by this organism. However, in the same study,
esp
-deficient strains of
E. faecalis
were found to be capable of biofilm formation. To test the hypothesis that Esp is dispensable for biofilm formation by
E. faecalis
, we used microtiter plate assays and a chemostat-based biofilm fermentor assay to examine biofilm formation by genetically well-defined, non-Esp-expressing strains. Our results demonstrate that in vitro biofilm formation occurs, not only in the absence of
esp
, but also in the absence of the entire pathogenicity island that harbors the
esp
coding sequence. Using scanning electron microscopy to evaluate biofilms of
E. faecalis
OG1RF grown in the fermentor system, biofilm development was observed to progress through multiple stages, including attachment of individual cells to the substratum, microcolony formation, and maturation into complex multilayered structures apparently containing water channels. Microtiter plate biofilm analyses indicated that biofilm formation or maintenance was modulated by environmental conditions. Furthermore, our results demonstrate that expression of a secreted metalloprotease, GelE, enhances biofilm formation by
E. faecalis
. In summary,
E. faecalis
forms complex biofilms by a process that is sensitive to environmental conditions and does not require the Esp surface protein.
Formation and Composition of the
Bacillus anthracis
Endospore
Authors: Liu Hongbin , Bergman Nicholas H. , Thomason Brendan , Shallom Shamira , Hazen Alyson , Crossno Joseph , Rasko David A. , Ravel Jacques , Read Timothy D. , Peterson Scott N. , Yates John , Hanna Philip C. 
Published: December 2003

ABSTRACT

The endospores of
Bacillus anthracis
are the infectious particles of anthrax. Spores are dormant bacterial morphotypes able to withstand harsh environments for decades, which contributes to their ability to be formulated and dispersed as a biological weapon. We monitored gene expression in
B. anthracis
during growth and sporulation using full genome DNA microarrays and matched the results against a comprehensive analysis of the mature anthrax spore proteome. A large portion (∼36%) of the
B. anthracis
genome is regulated in a growth phase-dependent manner, and this regulation is marked by five distinct waves of gene expression as cells proceed from exponential growth through sporulation. The identities of more than 750 proteins present in the spore were determined by multidimensional chromatography and tandem mass spectrometry. Comparison of data sets revealed that while the genes responsible for assembly and maturation of the spore are tightly regulated in discrete stages, many of the components ultimately found in the spore are expressed throughout and even before sporulation, suggesting that gene expression during sporulation may be mainly related to the physical construction of the spore, rather than synthesis of eventual spore content. The spore also contains an assortment of specialized, but not obviously related, metabolic and protective proteins. These findings contribute to our understanding of spore formation and function and will be useful in the detection, prevention, and early treatment of anthrax. This study also highlights the complementary nature of genomic and proteomic analyses and the benefits of combining these approaches in a single study.
Fine-Tuning in Regulation of Clp Protein Content inBacillus subtilis
Authors: Gerth Ulf , Kirstein Janine , Mostertz Jörg , Waldminghaus Torsten , Miethke Marcus , Kock Holger , Hecker Michael 
Published: December 2003

ABSTRACTClp-controlled proteolysis inBacillus subtilisseems to play a substantial role, particularly under stress conditions. Calibrated Western blot analyses were used to estimate the approximate numbers of heat-inducible Clp molecules within a single cell. According to these numbers, the different Clp ATPases do not seem to compete for the proteolytic subunit ClpP. Coimmunoprecipitation experiments revealed the predicted specific ClpX-ClpP, ClpC-ClpP, and ClpE-ClpP interactions. ClpE and ClpX are rapidly degraded in wild-type cells during permanent heat stress but remained almost stable in aclpPmutant, suggesting ClpP-dependent degradation. In particular, ClpCP appeared to be involved in the degradation of the short-lived ClpE ATPase, indicating a negative “autoregulatory” circuit for this particular Clp ATPase at the posttranslational level. Analysis of the half-life of stress-inducibleclpmRNAs during exponential growth and heat shock revealed precise regulation of the synthesis of each Clp protein at the posttranscriptional level as well to meet the needs ofB. subtilis.
Surfaces of Spo0A and RNA Polymerase Sigma Factor A That Interact at the
spoIIG
Promoter in
Bacillus subtilis
Authors: Kumar Amrita , Buckner Starke Cindy , DeZalia Mark , Moran Charles P. 
Published: December 2003

ABSTRACT

In
Bacillus subtilis
, the DNA binding protein Spo0A activates transcription from two classes of promoters, those used by RNA polymerase containing the primary sigma factor, σ
A
(e.g.,
spoIIG
), and those used by RNA polymerase containing the secondary sigma factor, σ
H
(e.g.,
spoIIA
). Several single amino acid substitutions in region 4 of σ
A
define positions in σ
A
that are specifically required for Spo0A-dependent promoter activation. Similarly, several single amino acid substitutions in Spo0A define positions in Spo0A that are required for σ
A
-dependent promoter activation but not for other functions of Spo0A. It is unknown whether these amino acids in Spo0A interact directly with those in region 4 of σ
A
or whether they interact with another subunit of RNA polymerase to effect promoter activation. Here we report the identification of a new amino acid in region 4 of σ
A
, arginine at position 355 (R355), that is involved in Spo0A-dependent promoter activation. To further investigate the role of R355, we used the coordinates of Spo0A and sigma region 4, each in complex with DNA, to build a model for the interaction of σ
A
and Spo0A at the
spoIIG
promoter. We tested the model by examining the effects of amino acid substitutions in the putative interacting surfaces of these molecules. As predicted by the model, we found genetic evidence for interaction of R355 of σ
A
with glutamine at position 221 of Spo0A. These results appear to define the surfaces of Spo0A and σ
A
that directly interact during activation of the
spoIIG
promoter.