bluuebunny/crossref_metadata_2025 huggingface dataset:
Information technology repositories and knowledge management processes
Authors: Franco Massimo , Mariano Stefania
Published: November 2007

Purpose

The purpose of this paper is to address the impact of information technology repositories (ITR) in the implementation of KM processes, i.e. knowledge storage and retrieval.

Design/methodology/approach

A case study design is used. Data are collected through the use of individual semi‐structured interviews, observations and document analysis.

Findings

This study found that three factors were likely to influence the knowledge retrieval process from information technology repositories and that the process of storage was connected to three distinct events that happened before, during, and after the repository was introduced into the organization. Furthermore, it was also found that knowledge management processes, i.e. knowledge storage and retrieval, were connected to individual learning.

Research limitations/implications

This study has limitations connected to empirical generalizability because it is a single case study research. Also, this study focuses only on two knowledge management processes, i.e. knowledge storage and retrieval.

Practical implications

Findings suggest the need for managers to recognize the influence of leadership on knowledge management processes, i.e. knowledge sharing and storage. Another implication is that, when an organization wants to make information technology repositories more effective, rules and templates should be implemented to correctly use and update such repositories.

Originality/value

This research identifies the connections between knowledge management processes, i.e. knowledge storage and retrieval and individual learning processes. It also suggests four strategies to implement in order to make information technology repositories more effective.
Implementation of KM strategies in the Malaysian telecommunication industry
Authors: Wei Chong Chin , Choy Chong Siong , Yew Wong Kuan
Published: November 2007

Purpose

This purpose of this paper is to assess the perceived importance and actual implementation of four knowledge management (KM) strategies, i.e. culture; leadership; information technology; and measurement, in the Malaysian telecommunication industry.

Design/methodology/approach

Data were collected from 289 telecommunication organizations in Malaysia and analyzed using indices and parametric statistics.

Findings

The paired t‐test results show significant differences among all the KM strategies in terms of their importance and actual implementation. Strategies such as technology, culture and leadership are moderately implemented, with measurement being the least implemented factor.

Research limitations/implications

This paper focuses on KM implementation rather than on learning and knowledge utilization.

Practical implications

Malaysian telecommunication organizations should give equal attention to the implementation of all the four KM strategies. They need to have proper planning and overcome any problem or difficulty for the four KM strategies to be implemented smoothly, and subsequently narrow the gaps between the perceived importance and actual implementation of these strategies. Such viable practice will significantly help the government of Malaysia to achieve the K‐Economy status and Vision 2020.

Originality/value

This study is perhaps one of the first to empirically investigate and compare the perceived importance and actual implementation of the four KM strategies in the Malaysian telecommunication industry.
Value‐added knowledge management for financial performance
Authors: Sharma Ravi S. , Teng Yu Hui Priscilla , Tan Meng‐Wah
Published: November 2007

Purpose

This paper aims to study the economic significance of using a blended business and knowledge strategy through the lens of conventional financial management before and after the implementation of KM initiatives in a knowledge‐intensive, high‐growth firm that had gone through business diversification through organic developments as well as mergers and acquisitions for over a decade.

Design/methodology/approach

The economic value added (EVA) method is proposed as a measure of the effective usage of capital funding in the firm before and after its KM program. The extent of the economic impact due to the contributions of various KM strategies was analyzed using standard financial management reporting. This enabled the derivation of follow‐on KM initiatives that were consistent with the target objectives.

Findings

The EVA method was found to be valid and credible in determining the net impact of various KM initiatives. This was in a form that was comprehensible to top management and KM decision‐makers.

Research limitations/implications

Knowledge management as a strategic imperative has gained significance over the past decade for its ability to handle the complexity of information to further create, transfer and reuse intellectual capital. More importantly, KM is seen as the key business enabler across different enterprises for its ability to enhance competitiveness and shareholder value. The EVA method used in this paper has allowed the valuation of KM initiatives.

Practical implications

The emergence of KM as a blended business strategy has hence proved to be vital for the sustainability of the knowledge‐driven business model that looks beyond the physical and financial into intellectual and social capital.

Originality/value

The paper presents a longitudinal case study of a fairly large East Asian conglomerate.
Effective educational process: a data‐mining approach
Authors: Ranjan Jayanthi , Malik Kamna
Published: November 2007

Purpose

The purpose of this paper is to develop a holistic model for educational purposes using data‐mining techniques for exploring the effects of probable changes in processes related to admissions, course delivery and recruitments.

Design/methodology/approach

The paper proposes a framework for an effective educational process using data‐mining techniques to uncover the hidden trends and patterns and making accuracy based predictions through a higher level of analytical sophistication in the process of counselling students.

Findings

Data‐mining tools are used in academia for capitalizing on the advances of information technology. This process improves research and academic decision making through uncovering hidden trends and patterns that predict using a combination of explicit knowledge base, sophisticated analytical skills and academic domain knowledge.

Originality/value

The paper presents a model using a data‐mining approach for academics.
Investigation of environmental reliability of optical polymer waveguides embedded on printed circuit boards
Authors: Immonen Marika P. , Karppinen Mikko , Kivilahti Jorma K.
Published: November 2007

Purpose

To investigate the influences of environmental stresses on board‐embedded polymeric waveguides.

Design/methodology/approach

Optical multimode waveguides were embedded on printed circuit boards using commercial polymers. The optical‐PCBs varying in board structure and in optical build‐up materials were exposed to heat, moisture and ionic‐contaminants in accelerated reliability tests. The influence of stress factors on the structural integrity and functional parameters, namely the refractive index and optical transmissivity, was investigated at the key communication wavelengths.

Findings

Isothermal annealing reduced the refractive index to the greatest extent. The optical‐PCB structure with an optical surface build‐up layer was observed to be more vulnerable under temperature shock when compared with the optical‐PCB with optical inner layer. The buffer layer beneath the optical build‐up was found to improve the stability of the optical waveguides significantly. The results indicated of wavelength dependence to the aging factor with a failure mechanism. The factors affecting the performance and reliability of polymer‐based optical waveguides on PCBs were discussed.

Research limitations/implications

More experimental data and investigations of failure mechanisms are required to ultimately obtain sufficient reliability statistics for accurate life‐time prediction models.

Originality/value

Optical interconnects are seen as a promising solution to overcome performance limitations encountered with high‐frequency electrical interconnections. As an emerging technology, only a limited amount of reliability data on optical/electrical packages is available. The paper investigates the influences of environmental stresses on board‐embedded polymeric waveguides.
Using both linear and non‐linear dimensional analysis, correction and prediction to improve PCB yields
Authors: Kelley Andrew
Published: November 2007

Purpose

To present an update and the latest results from work on a project aimed at enabling printed circuit board (PCB) manufacturing to reduce the effect upon production yields by material distortions during the manufacturing process.

Design/methodology/approach

Measurement data was collated from inspection steps within the PCB manufacturing process and analysed to provide data describing the distortions of materials used. The data was used to generate a self‐learning model which can be used to predict material movement prior to manufacture.

Findings

The data collated enabled CAM engineers at the design introduction stage to model the PCB build and simulate the material movement that will take place during the manufacturing processes. With this knowledge, the correct compensations to counter the material movement can be applied to the production tooling, eliminating the need to run manufacturing test batches.

Research limitations/implications

The technology has been used to ensure inner‐layer designs with nominal dimensions after the lamination stage. Further, development work should be undertaken to collate measured data from other parts of the PCB manufacturing process and model the material movement around all registration critical processes.

Originality/value

The paper details how data collated by production processes can be utilised to train mathematical models and provide modified‐tooling information to increase yields in the manufacturing process.
PWB reliability – the next step
Authors: Reid Paul
Published: November 2007

Purpose

To share the findings of recent investigations of the influences of RoHS requirements on printed wire board (PWB) reliability.

Design/methodology/approach

Interconnect stress testing was used to measure the reduction in reliability of coupons that replicated high‐density multilayer circuit boards, after exposure to a simulation of the thermal excursion associated with “tin‐lead” and “lead‐free” assembly and rework. Coupons were preconditioned by exposure to tin‐lead assembly temperatures (230°C) or lead‐free assembly temperatures (245 or 260°C). Standard statistical methods were applied to the test data, which was compared between more than 20 dielectric materials.

Findings

There is a shift from copper quality being the dominant influence in reliability to copper and material quality working in concert being the major influence on PWB reliability. Delamination and crazing increases with lead‐free assembly and rework and this has the effect of artificially extending cycles to failure, frequently confounding data. Reliability testing to lead‐free temperatures requires an evaluation for delamination to ensure the cycle data are not artificially extended. A robust, well fabricated coupon's reliability is found to be reduced by 50 percent after lead‐free assembly and rework.

Research limitations/implications

There is objective evidence of a significant reduction in reliability with the thermal excursion associated with lead‐free assembly but there has been no apparent reduction in acceptance criteria or limitation on warranties. This paper does not address the influence of reliability on the solder joints, components or other structures of an assembled PWB. This paper is limited to reliability influences on the PWB. The identification of materials used in this study is protected under non‐disclosure agreements.

Originality/value

This study expands the understanding of the implications of the effect of RoHS requirements on PWB reliability. It allows companies to optimise PWB reliability with quality fabrication, using robust materials and optimised PWB designs and to make sound business decisions in order to meet the new challenges of RoHS. Meeting the challenge of RoHS is not limited to a question of compliance by getting the lead out; it is also a question of optimising PWB's reliability.
Conformal coatings and their increasing importance for a safe operation of electronic assemblies
Authors: Suppa Manfred
Published: November 2007

Purpose

The paper aims to describe the various moisture loads affecting conformal coatings. It also seeks to differentiate these from dewing. In the case of dewing, osmotic processes may trigger completely different chemical‐physical processes on the electronic assemblies.

Design/methodology/approach

Numerous test methods are available to verify the climatic resistances of conformal coatings. Focussing on moisture load and dewing, the different types of load are discussed and illustrated by means of examples.

Findings

The tests performed to ascertain the temperature and moisture load of conformal coatings show that under these high loads the electrical functional reliability is maintained. Thus, impacts of the individual process steps can be examined and assessed by means of moisture and insulation measurements.

Research limitations/implications

Utilising different stress evaluations the described tests demonstrate the qualities of conformal coatings for electrical assemblies. Prospective tests for the purpose of lacquer and process qualification are presented.

Originality/value

The physical‐chemical load types with their consequences on conformal coatings for the protection of electrical assemblies are described.
Female career progression in retailing
Authors: Foster Carley , Whysall Paul , Harris Lynette
Published: November 2007

Purpose

The aim of this paper is to highlight the factors that limit and support female career progression in the retail industry.

Design/methodology/approach

The research used a combination of quantitative and qualitative research methods. Data were collected from employees and managers working in 31 stores belonging to national stores operating in the East Midlands as well as ten SME independent retailers based in the region.

Findings

The women in this study can be categorised into those women who are not interested in pursuing a career in retail, those that seek promotion but have difficulties balancing the demands of their work and domestic circumstances and those who have actively pursued a career in the industry. Despite these categorisations, the study suggests that the career progression of all female staff is helped and hindered by a number of interrelating factors, such as whether they have a role model, are loyal to the store they work in or have children.

Practical implications

It is proposed that career initiatives in retailing need to be more adaptable so that they take account of the different development needs of these three types of women.

Originality/value

This is a large‐scale study that uses a mixed method approach and considers the opinions of store staff working in a range of roles.
Students' views of retail employment – key findings from Generation Ys
Authors: Broadbridge Adelina M. , Maxwell Gillian A. , Ogden Susan M.
Published: November 2007

Purpose

The aim of this paper is to highlight some preliminary findings regarding students' perceptions of retail employment. It concentrates on those students who belong to Generation Y, those born between 1977 and 1994.

Design/methodology/approach

The research instrument consisted of a questionnaire survey administered to business studies students at two Scottish universities – Glasgow Caledonian University and Stirling University. This paper reports on responses to 340 of these questionnaires – those students who already have some experience of retail employment, mainly as their part‐time employment experiences while studying for their degree.

Findings

Retail employment experience is common with the majority of students. Their expectations for future retail employment after graduation is to enjoy their work, while they are also concerned with fairness, equality and tolerance from their future employment.

Practical implications

The results are of benefit to retail employers' as preliminary indications of how they can attract potential graduate entrants into the sector. They provide some areas that retail companies should be addressing in their recruitment literature. These factors include future career opportunities including opportunities for self development, training and development, as well as pay and job security. Other factors that are also important to highlight are responsibility and challenging work opportunities and the maintenance of a good work‐life balance.

Originality/value

This is an under‐researched topic in the area of retail employment and Generation Y.
Permission‐based mobile marketing and sources of trust in selected European markets
Authors: Kautonen Teemu , Karjaluoto Heikki , Jayawardhena Chanaka , Kuckertz Andreas
Published: November 2007

Purpose

The purpose of this paper is to provide a three‐country comparison of personal and institutionally based trust as factors affecting consumers' willingness to participate in permission‐based mobile marketing.

Design/methodology/approach

A conceptual model of different dimensions of personal and institutionally based trust and their effect on the consumer's willingness to provide personal information and the permission to use it is tested with data from surveys of young consumers in Finland, Germany and the UK. The data were analysed by structural equation modelling (LISREL8.7).

Findings

The main factor affecting the consumers' decision to participate in mobile marketing is the company's media presence, which is a significant factor in all three countries.

Research limitations/implications

While the results of this study establish the sources of trust that play a role in permission‐based mobile marketing, the study of trust in the context of mobile marketing would greatly benefit from research that addresses the process of how trust emerges and develops over time. As a company's presence in the media weighs more than the customer's own experiences or control, mobile marketers should focus on building a strong and positive media presence and image in order to gain consumers' permission for mobile marketing.

Practical implications

As a company's reputation conveyed by the media weighs more than the customer's own experiences, mobile marketers should focus on building a strong and positive media presence and image, and thereby gain consumers' trust.

Originality/value

The paper is the first international empirical investigation of the different antecedents of trust in the context of mobile marketing.
Approaches to strategic alignment of business and information systems
Authors: Kajalo Sami , Rajala Risto , Westerlund Mika
Published: November 2007

Purpose

Technology‐related issues have an increasing impact on business. The alignment between overall business objectives and technology‐related decisions, such as decisions on application service acquisitions, resurfaces occasionally in the intense academic discussion on information systems (IS). Prior research indicates that the alignment of business and IS decisions remains a major concern for business practitioners. The purpose of this paper is to analyze the factors that drive the consistency in technology‐related decisions and result in diverse modes of business‐IS alignment.

Design/methodology/approach

This study investigates application service acquisitions among the top 200 firms in Finland. In this quantitative empirical study, principal component analysis with varimax rotation method is used to examine the companies' drivers for business‐IS alignment. Moreover, the firms are categorized using the cluster analysis method.

Findings

This study identifies four factors that drive the achievement of business‐IS alignment. These factors are: awareness of the impact and risks of IS decisions, efficacy of IS management, systematic decision making process, and business development orientation of IS management. Moreover, the study identifies four clusters of firms that illustrate diverse modes of business‐IS alignment: ad‐hoc alignment, business‐driven alignment, consensual alignment, and technology‐driven alignment.

Originality/value

The value of the study lies in revealing the key factors influencing the alignment of vital IS investments and the overall business strategy. The study identifies four clearly different approaches to business‐IS alignment. Moreover, the paper suggests that business‐IS alignment stems from several factors, including the collective development of strategies that reflect the combined knowledge of business and IS managers.
Business assistance for SMEs: New Zealand owner‐managers make their assessment
Authors: Lewis Kate , Massey Claire , Ashby Mary , Coetzer Alan , Harris Candice
Published: November 2007

Purpose

The purpose of this paper is to explore the business assistance realities of New Zealand small and medium enterprise (SME) owner‐managers in order to better understand those experiences in terms of their ability to identify and use what is provided.

Design/methodology/approach

Site visits were made to 51 small firms that had been recruited from a random sample of 500 New Zealand firms that employed up to 50 full‐time equivalent staff and were in the “manufacturing” or “service” sector. An interview was then carried out with the owner‐manager of the firm.

Findings

The owner‐managers of some SMEs interact with the support infrastructure regularly, while others do not. The sources of business assistance most frequently accessed where not necessarily those that were subsequently perceived as being the most useful or significant.

Research limitations/implications

The findings are limited in their generalisability due to the research methodology and research context. However, the conclusions will be of interest to researchers, policy‐makers and business assistance providers.

Originality/value

The paper addresses a gap in the knowledge base surrounding business assistance and SMEs. Typically investigations on this topic focus on supply‐side issues (i.e. how service provision can be improved) rather than those that relate to demand (i.e. investigating the needs of owner‐managers). The project was unique in the New Zealand context (both in terms of scale and research approach).
Can broadband access rescue the rural economy?
Authors: Galloway Laura
Published: November 2007

Purpose

Government is promoting broadband for all, and specifically, is advocating business up‐take of broadband that affords high‐speed internet activity, to foster global competitiveness. Urban areas have economies of scale and the effect on price of concentration of demand. Rural areas do not, and potential broadband provision is thus problematic. The paper aims to study technology roll‐out in rural areas, and provide a commentary, based on empirical work, on the potential of demand for, and use of, the service.

Design/methodology/approach

The paper draws from secondary research sourced from academic papers, government and agency documents to evaluate rural broadband provision, and analyses the suitability of current “solutions”. It also draws together conclusions of various empirical and survey researches on the potential of uptake and business use of broadband.

Findings

The paper questions whether broadband access in rural areas has the potential to contribute to economic development. It also identifies the limitations of current broadband technologies, concluding that, in fact, none are appropriate for rural and remote locations. The paper finds that rural businesses tend to lack propensity for growth and diversification; therefore, accessibility for rural businesses may be an issue secondary to that of lack of enterprise in many rural areas. Therefore, efforts to roll out technology to rural areas may not provide results desired or expected.

Originality/value

The value of the paper lies in providing a holistic viewpoint, based on research and technology considerations, from which policy can be informed.
Consumer trust: privacy policies and third‐party seals
Authors: Peterson Dane , Meinert David , Criswell John , Crossland Martin
Published: November 2007

Purpose

This study aims to compare the effectiveness of third‐party seals with self‐reported privacy policy statements with regard to the willingness of potential e‐commerce customers to provide web sites with various types of personal information.

Design/methodology/approach

A survey was administered to 374 graduate business students at two Midwestern universities in the USA.

Findings

The results indicated that third‐party seals were not as effective as self‐reported privacy statements with a strong guarantee of security.

Research limitations/implications

This study did not provide any evidence to support the necessity for small enterprises to incur the added costs in terms of money and time required to obtain a third‐party seal. Rather the results suggest small enterprises may increase consumer trust more effectively through strong privacy policy statements.

Originality/value

This study provides useful information on the effectiveness of third‐party seals with self‐reported privacy policy statements with regard to the willingness of potential e‐commerce customers to provide web sites with various types of personal information.
Job‐matching and employee diversity: an exploratory study
Authors: Ruggeri Stevens Geoff
Published: November 2007

Purpose

The investigation reported here aims to: adapt existing recruitment theory to add to tools available to small business recruiters for job matching; provide job‐specific scoring methods to help employers in recruitment processes; and enhance the consideration of reasonable adjustment issues in the possible employment of disabled individuals.

Design/methodology/approach

A total of 32 interviews were conducted on‐site with managers to devise and test templates combining person specifications with job characteristics, based on managers' judgements of what is important. The methods devised and used are an original adaptation of repertory grid principles. Where there were disabled employees, indications of the employees' success and difficulty were elicited.

Findings

A simplified derivative of repertory grid method to give a combined abilities/tasks matrix was found usable and clarifying by respondents.

Research limitations/implications

The investigation was confined to hotel and leisure small to medium‐sized enterprises in Sussex, UK. As they stand, the methods could be used in business sectors beyond the sector to which the research reported in this paper has been confined, but further work is needed on resource consequences, and on the implications for state benefits and related support in the case of disabled applicants.

Originality/value

Results of the analysis could be used almost immediately by a company: for future applicants, the company could make direct use of the completed matrix by scoring the applicant on the matrix variables, superimposing the applicant matrix on the requirements matrix, and calculating the percentage of desirable scores met.
Performance measurement in the construction research and development
Authors: Kulatunga Udayangani , Amaratunga Dilanthi , Haigh Richard
Published: November 2007

Purpose

The purpose of this paper is to highlight the importance of performance measurement (PM) within construction research and development (R&D) activities to enhance its efficiency and effectiveness.

Design/methodology/approach

A comprehensive literature review is used as the methodology of this paper where it will look into two main areas. First, the paper discusses R&D work in construction industry with particular reference to its role, main contributors, and the issues which hinders its successfulness. From this section the paper arrives at a definition for construction R&D and the scope of the study. The second section of the paper defines PM and identifies the importance of it in general. Finally, the paper justifies how the issues within construction R&D could be minimised by implementing PM system.

Findings

The paper justifies the implementation of PM within construction R&D and identifies how PM could enhance the efficiency and effectiveness of construction R&D through: identifying requirements of the parties involved within the research process; defining clear aims and objectives; evaluation of the successfulness of activates/confirmation of milestones; providing information for the research funders regarding the utilisation of resources; improving the communication and coordination of the parties involved; and providing feedback for future improvements of the research work.

Originality/value

The paper reveals the impact and influence of PM towards the construction R&D activities.
Characterization of the slowly inactivating sodium current INa2 in canine cardiac single Purkinje cells
Authors: Bocchi L. , Vassalle M.
Published: November 2007

The aim of our experiments was to investigate by means of a whole cell patch‐clamp technique the characteristics of the slowly inactivating sodium current (INa2) found in the plateau range in canine cardiac Purkinje single cells. The INa2 was separated from the fast‐activating and ‐inactivating INa (labelled here INa1) by applying a two‐step protocol. The first step, from a holding potential (Vh) of −90 or −80 mV to −50 mV, led to the quick activation and inactivation of INa1. The second step consisted of depolarizations of increasing amplitude from −50 mV to less negative values, which led to the quick activation and slow inactivation of INa2. The INa2 was fitted with a double exponential function with time constants of tens and hundreds milliseconds, respectively. After the activation and inactivation of INa1 at −50 mV, the slope conductance was very small and did not change with time. Instead, during INa2, the slope conductance was larger and decreased as a function of time. Progressively longer conditioning steps at −50 mV resulted in a progressive decrease in amplitude of INa2 during the subsequent test steps. Gradually longer hyperpolarizing steps (increments of 100 ms up to 600 ms) from Vh−30 mV to −100 mV were followed on return to −30 mV by a progressively larger INa2, as were gradually more negative 500 ms steps from Vh−30 mV to −90 mV. At the end of a ramp to −20 mV, a sudden repolarization to approximately −35 mV fully deactivated INa2. The INa2 was markedly reduced by lignocaine (lidocaine) and by low extracellular [Na+], but it was little affected by low and high extracellular [Ca2+]. At negative potentials, the results indicate that there was little overlap between INa2 and the transient outward current, Ito, as well as the calcium current, ICa. In the absence of Ito and ICa (blocked by means of 4‐aminopyridine and nickel, respectively), INa2 reversed at 60 mV. In conclusion, INa2 is a sodium current that can be initiated after the inactivation of INa1 and has characteristics that are quite distinct from those of INa1. The results have a bearing on the mechanisms underlying the long plateau of Purkinje cell action potential and its modifications in different physiological and pathological conditions.
Modeling Helicopter Blade Sailing: Dynamic Formulation in the Planar Case
Authors: Wall A. S. , Langlois R. G. , Afagh F. F.
Published: November 2007

As part of a research project aimed at simulating rotor dynamic response during shipboard rotor startup and shutdown operations, a dynamic model of the ship–helicopter–rotor system that is appropriate for use in predicting rotor elastic response was developed. This planar model consists of a series of rigid bodies connected by rotational stiffness and damping elements that allow motion in the flapwise direction. The rotors were partitioned into an arbitrary number of rigid beam segments having the inertial and geometrical properties of a typical rotor. Helicopter suspension flexibility and damping were also modeled, although the helicopter was otherwise considered as a rigid body. Lagrange’s equation was used to derive the governing dynamic equations for the helicopter–rotor model. The effect of ship motion on blade deflection was also considered. The ship motion supplied as input to the model included representative frigate flight deck motion in three dimensions corresponding to an actual sea spectrum, ship particulars and ship operating conditions. This paper is intended to detail the dynamic approach adopted for this blade sailing study, and its conceptual validation in the planar case. The methodologies that have been developed lend themselves to easy expansion into three dimensions, and into torsion and lead/lag modeling. The amount of blade motion induced by ship motion on nonrotating helicopter blades is included. Although aerodynamic loads are a major contributor to blade sailing, this paper focuses on the dynamics aspect of the problem, and thus does not include aerodynamic effects.
Role of Solvent-Host Interactions That Lead to Very Large Swelling of Hybrid Frameworks
Authors: Serre C. , Mellot-Draznieks C. , Surblé S. , Audebrand N. , Filinchuk Y. , Férey G.
Published: November 2007

An unusually large expansion upon solvent adsorption occurs without apparent bond breaking in the network of a series of isoreticular chromium(III) or iron(III) diarboxylates labeled MIL-88A to D [dicarbox = fumarate (88A); terephthalate (1,4-BDC) (88B); 2,6-naphthalenedicarboxylate (2,6-NDC) (88C); and 4-4′-biphenyldicarboxylate (4-4′-BPDC) (88D)]. This reversible “breathing” motion was analyzed in terms of cell dimensions (extent of breathing), movements within the framework (mechanism of transformation), and the interactions between the guests and the skeleton. In situ techniques show that these flexible solids are highly selective absorbents and that this selectivity is strongly dependent on the nature of the organic linker.
Protein Composition of Catalytically Active Human Telomerase from Immortal Cells
Authors: Cohen Scott B. , Graham Mark E. , Lovrecz George O. , Bache Nicolai , Robinson Phillip J. , Reddel Roger R.
Published: November 2007

Telomerase is a ribonucleoprotein enzyme complex that adds 5′-TTAGGG-3′ repeats onto the ends of human chromosomes, providing a telomere maintenance mechanism for ∼90% of human cancers. We have purified human telomerase ∼10
8
-fold, with the final elution dependent on the enzyme's ability to catalyze nucleotide addition onto a DNA oligonucleotide of telomeric sequence, thereby providing specificity for catalytically active telomerase. Mass spectrometric sequencing of the protein components and molecular size determination indicated an enzyme composition of two molecules each of telomerase reverse transcriptase, telomerase RNA, and dyskerin.
Cloning and Characterization of Two
Lactobacillus casei
Genes Encoding a Cystathionine Lyase
Authors: Irmler Stefan , Raboud Sylvie , Beisert Beata , Rauhut Doris , Berthoud Hélène
Published: November 2007

Volatile sulfur compounds are key flavor compounds in several cheese types. To better understand the metabolism of sulfur-containing amino acids, which certainly plays a key role in the release of volatile sulfur compounds, we searched the genome database of
Lactobacillus casei
ATCC 334 for genes encoding putative homologs of enzymes known to degrade cysteine, cystathionine, and methionine. The search revealed that
L. casei
possesses two genes that putatively encode a cystathionine β-lyase (CBL; EC 4.4.1.8). The enzyme has been implicated in the degradation of not only cystathionine but also cysteine and methionine. Recombinant CBL proteins catalyzed the degradation of
l
-cystathionine,
O
-succinyl-
l
-homoserine,
l
-cysteine,
l
-serine, and
l
-methionine to form α-keto acid, hydrogen sulfide, or methanethiol. The two enzymes showed notable differences in substrate specificity and pH optimum.
Population Structures of Two Genotypes of
Vibrio vulnificus
in Oysters (
Crassostrea virginica
) and Seawater
Authors: Warner Elizabeth , Oliver James D.
Published: November 2007

Vibrio vulnificus
biotype 1 strains can be classified into two genotypes based on the PCR analysis of variations in the virulence-correlated gene (
vcg
). Genotype has been correlated with human infection for 90% of isolates from human cases having the
vcgC
sequence type and 87% of environmental strains having the
vcgE
variant. In this study we examined the dynamics of
V. vulnificus
populations and the distribution of the two genotypes recovered from oysters and surrounding estuarine wasters. Analysis of 880 isolates recovered from oysters showed a disparity in the ratio of the two genotypes, with those of the
vcgE
(E) genotype accounting for 84.4% of the population. In contrast, 292 isolates recovered from the waters surrounding the oyster sites revealed an almost equal distribution of the two genotypes. The levels of
vcgC
(C genotype) strains from both sources increased as a percentage of the population as water temperatures increased, while no culturable
V. vulnificus
cells were recovered from December through February. Our results suggest that there is a selective advantage for strains of the E genotype within oysters while survival of the C genotype strains may be favored by increased water column temperatures. These data suggest that the low incidence of infections may be due to the comparatively rare consumption of an oyster that contains a greater number of
V. vulnificus vcgC
genotype strains than of
vcgE
genotype strains. Levels of the two genotypes as well as seasonal dynamics within both oyster tissue and the surrounding waters may aid in identifying risk factors associated with human infection.
Prevalence of Lysogeny among Soil Bacteria and Presence of 16S rRNA and
trzN
Genes in Viral-Community DNA
Authors: Ghosh Dhritiman , Roy Krishnakali , Williamson Kurt E. , White David C. , Wommack K. Eric , Sublette Kerry L. , Radosevich Mark
Published: November 2007

Bacteriophages are very abundant in the biosphere, and viral infection is believed to affect the activity and genetic diversity of bacterial communities in aquatic environments. Lysogenic conversion, for example, can improve host fitness and lead to phage-mediated horizontal gene transfer. However, little is known about lysogeny and transduction in the soil environment. In this study we employed atrazine-impregnated Bio-Sep beads (a cell immobilization matrix) to sample active microbiota from soils with prior pesticide exposure history. Once recovered from soil, the bead communities were induced with mitomycin C (MC), and viral and bacterial abundances were determined to evaluate the incidence of inducible prophage in soil bacteria. The inducible fraction calculated within bead communities was high (ca. 85%) relative to other studies in aquatic and sedimentary environments. Moreover, the bacterial genes encoding 16S rRNA and
trzN
, a chlorohydrolase gene responsible for dehalogenation of atrazine, were detected by PCR in the viral DNA fraction purified from MC-induced bead communities. A diverse collection of actinobacterial 16S rRNA gene sequences occurred within the viral DNA fraction of induced, water-equilibrated beads. Similar results were observed in induced atrazine-equilibrated beads, where 77% of the cloned sequences were derived from actinobacterial lineages. Heterogeneous 16S rRNA gene sequences consisting of fragments from two different taxa were detected in the clone libraries. The results suggest that lysogeny is a prevalent reproductive strategy among soil bacteriophages and that the potential for horizontal gene transfer via transduction is significant in soil microbial communities.
Eucaryotic Diversity in a Hypersaline Microbial Mat
Authors: Feazel Leah M. , Spear John R. , Berger Alicia B. , Harris J. Kirk , Frank Daniel N. , Ley Ruth E. , Pace Norman R.
Published: November 2007

To determine the eucaryotic diversity of the hypersaline Guerrero Negro microbial mat, we amplified 18S rRNA genes from DNA extracted from this mat and constructed and analyzed clone libraries. The extent of eucaryotic diversity detected was remarkably low, only 15 species among 890 clones analyzed. Six eucaryotic kingdoms were represented, as well as a novel cluster of sequences. Nematode sequences dominated the clone libraries.
Prokaryotic Suppression Subtractive Hybridization PCR cDNA Subtraction, a Targeted Method To Identify Differentially Expressed Genes
Authors: De Long Susan K. , Kinney Kerry A. , Kirisits Mary Jo
Published: November 2007

Molecular biology tools can be used to monitor and optimize biological treatment systems, but the application of nucleic acid-based tools has been hindered by the lack of available sequences for environmentally relevant biodegradation genes. The objective of our work was to extend an existing molecular method for eukaryotes to prokaryotes, allowing us to rapidly identify differentially expressed genes for subsequent sequencing. Suppression subtractive hybridization (SSH) PCR cDNA subtraction is a technique that can be used to identify genes that are expressed under specific conditions (e.g., growth on a given pollutant). While excellent methods for eukaryotic SSH PCR cDNA subtraction are available, to our knowledge, no methods previously existed for prokaryotes. This work describes our methodology for prokaryotic SSH PCR cDNA subtraction, which we validated using a model system:
Pseudomonas putida
mt-2 degrading toluene. cDNA from
P. putida
mt-2 grown on toluene (model pollutant) or acetate (control substrate) was subjected to our prokaryotic SSH PCR cDNA subtraction protocol to generate subtraction clone libraries. Over 90% of the sequenced clones contained gene fragments encoding toluene-related enzymes, and 20 distinct toluene-related genes from three key operons were sequenced. Based on these results, prokaryotic SSH PCR cDNA subtraction shows promise as a targeted method for gene identification.
LactobacillusStrain Diversity Based on Partialhsp60Gene Sequences and Design of PCR-Restriction Fragment Length Polymorphism Assays for Species Identification and Differentiation
Authors: Blaiotta Giuseppe , Fusco Vincenzina , Ercolini Danilo , Aponte Maria , Pepe Olimpia , Villani Francesco
Published: November 2007

A phylogenetic tree showing diversities among 116 partial (499-bp)Lactobacillus hsp60(groEL, encoding a 60-kDa heat shock protein) nucleotide sequences was obtained and compared to those previously described for 16S rRNA andtufgene sequences. The topology of the tree produced in this study showed aLactobacillusspecies distribution similar, but not identical, to those previously reported. However, according to the most recent systematic studies, a clear differentiation of 43 single-species clusters was detected/identified among the sequences analyzed. The slightly higher variability of thehsp60nucleotide sequences than of the 16S rRNA sequences offers better opportunities to design or develop molecular assays allowing identification and differentiation of either distant or very closely relatedLactobacillusspecies. Therefore, our results suggest thathsp60can be considered an excellent molecular marker for inferring the taxonomy and phylogeny of members of the genusLactobacillusand that the chosen primers can be used in a simple PCR procedure allowing the direct sequencing of thehsp60fragments. Moreover, in this study we performed a computer-aided restriction endonuclease analysis of all 499-bphsp60partial sequences and we showed that the PCR-restriction fragment length polymorphism (RFLP) patterns obtainable by using both endonucleases AluI and TacI (in separate reactions) can allow identification and differentiation of all 43Lactobacillusspecies considered, with the exception of the pairL. plantarum/L. pentosus. However, the latter species can be differentiated by further analysis with Sau3AI or MseI. Thehsp60PCR-RFLP approach was efficiently applied to identify and to differentiate a total of 110 wildLactobacillusstrains (including closely related species, such asL. caseiandL. rhamnosusorL. plantarumandL. pentosus) isolated from cheese and dry-fermented sausages.
Cloning of a Novel Gene Encoding β-1,3-Xylosidase from a Marine Bacterium,
Vibrio
sp. Strain XY-214, and Characterization of the Gene Product
Authors: Umemoto Yoshiaki , Onishi Ryosuke , Araki Toshiyoshi
Published: November 2007

The β-1,3-xylosidase gene (
xloA
) of
Vibrio
sp. strain XY-214 was cloned and expressed in
Escherichia coli
. The
xloA
gene consisted of a 1,608-bp nucleotide sequence encoding a protein of 535 amino acids with a predicted molecular weight of 60,835. The recombinant β-1,3-xylosidase hydrolyzed β-1,3-xylooligosaccharides to
d
-xylose as a final product.
Cholest-4-En-3-One-Δ
1
-Dehydrogenase, a Flavoprotein Catalyzing the Second Step in Anoxic Cholesterol Metabolism
Authors: Chiang Yin-Ru , Ismail Wael , Gallien Sébastien , Heintz Dimitri , Van Dorsselaer Alain , Fuchs Georg
Published: November 2007

The anoxic metabolism of cholesterol was studied in the denitrifying bacterium
Sterolibacterium denitrificans
, which was grown with cholesterol and nitrate. Cholest-4-en-3-one was identified before as the product of cholesterol dehydrogenase/isomerase, the first enzyme of the pathway. The postulated second enzyme, cholest-4-en-3-one-Δ
1
-dehydrogenase, was partially purified, and its N-terminal amino acid sequence and tryptic peptide sequences were determined. Based on this information, the corresponding gene was amplified and cloned and the His-tagged recombinant protein was overproduced, purified, and characterized. The recombinant enzyme catalyzes the expected Δ
1
-desaturation (cholest-4-en-3-one to cholesta-1,4-dien-3-one) under anoxic conditions. It contains approximately one molecule of FAD per 62-kDa subunit and forms high molecular aggregates in the absence of detergents. The enzyme accepts various artificial electron acceptors, including dichlorophenol indophenol and methylene blue. It oxidizes not only cholest-4-en-3-one, but also progesterone (with highest catalytic efficiency, androst-4-en-3,17-dione, testosterone, 19-nortestosterone, and cholest-5-en-3-one. Two steroids, corticosterone and estrone, act as competitive inhibitors. The dehydrogenase resembles 3-ketosteroid-Δ
1
-dehydrogenases from other organisms (highest amino acid sequence identity with that from
Pseudoalteromonas haloplanktis
), with some interesting differences. Due to its catalytic properties, the enzyme may be useful in steroid transformations.
A New Assay for Promoter Analysis in
Chlamydomonas
Reveals Roles for Heat Shock Elements and the TATA Box in
HSP70A
Promoter-Mediated Activation of Transgene Expression
Authors: Lodha Mukesh , Schulz-Raffelt Miriam , Schroda Michael
Published: November 2007

The aim of this work was to identify
cis
-regulatory sequences within the
Chlamydomonas HSP70A
promoter that mediate its stimulatory effect on the expression of downstream promoters. For this, we deleted/mutated the
HSP70A
promoter and, using a new assay, quantified its stimulatory effect. Our results indicate that the effect is mediated largely by heat shock elements and the TATA box.