bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost‐efficiencies, profitability, and strategic behavior: evidence from Japanese commercial banks
Authors: Hensel Nayantara D.
Published: June 2006

Purpose

To examine whether Japanese commercial banks exhibited economies of scale and economies of density at the time when the mega‐merger wave in Japanese banking began in the late 1990s. Since this merger wave has not yielded efficiencies, this analysis aims to shed light on whether banks, at the start of the wave, had reason to believe that larger banks would be more efficient.

Design/methodology/approach

Using a modified version of the translog cost function, the analysis estimates economies of scale and economies of density for Japanese city banks, trust banks, and regional banks. Then, the relationship between size and economies of scale/density and that between profitability and scale/density are explored using regression analysis.

Findings

Results suggest that larger banks (as measured by value of assets/loans/ deposits/investments, and number of employees/branches) were more likely to be in the decreasing/constant returns to scale/density region than smaller banks, The finding was statistically significant for all three types of Japanese banks. On average, city banks exhibited diseconomies of scale/density; trust banks exhibited constant returns to scale and increasing returns to density, and regional banks exhibited increasing returns to scale and density. This suggests that unions between city banks and either regional banks or trust banks may have been more likely to yield cost‐efficiencies, and raises questions concerning the efficiency motivations of the mega‐bank mergers. The findings further indicate that banks with higher sales were more likely to have exploited scale/density efficiencies, and that banks with higher net incomes were more likely to be in the increasing returns region.

Originality/value

This paper suggests that the mega‐merger wave in Japan in the late 1990s may not have been motivated by a desire for greater efficiencies through utilization of under‐utilized branch networks. Unlike other studies, this analysis differentiates between economies of scale and economies of density.
Currency risk management: simulating the Canadian dollar
Authors: Carrada‐Bravo Francisco , Hosseini Hassan K. , Fernandez Lorenzo
Published: June 2006

Purpose

The purpose of this article is to investigate the return associated with a Canadian dollar (C$) investment in the USA under passive, random walk, value at risk, and Sharpe ratio strategies.

Design/methodology/approach

To comply with the purpose, this paper used a GARCH model, and used, as basic data, daily C$ exchange rates and weekly US and Canadian interest rates on 90‐day CDs, from January 2 to November 26, 2004.

Findings

The empirical results suggest that currency returns are positively correlated to risk; and that the return provided by the random walk strategy beats the other strategies considered in this paper.

Practical implications

The findings suggest that currency investment is similar to other forms of investment, since it shows a positive relationship between risk and return. It also supports the long‐standing belief that sophisticated strategies do not beat simple‐minded approaches such as a random walk strategy.

Originality/value

This paper uses a utility function to investigate the response of investors to risk and return under different aversion scenarios.
Compensation satisfaction in the Baltics and the USA
Authors: Carraher Shawn M. , Whitney Gibson Jane , Buckley M. Ronald
Published: June 2006

Purpose

This study aims to examine the extent to which the demographic and work‐related variables of educational level, gender, age, salary level, organizational tenure, and union membership are useful predictors of satisfaction with pay level, benefits, raises, and the structure/administration of a compensation system. These variables have previously been utilized in the prediction of satisfaction with pay levels, but have not been tested as useful predictors of the other three dimensions of compensation satisfaction.

Design/methodology/approach

This study used multiple regression analyses and samples of 423 employees in the USA with a 63 percent response rate and 519 employees in the Baltics with a 73 percent response rate.

Findings

It was found that not all of the variables are equally useful predictors of each of the four dimensions of compensation satisfaction and that differential prediction is occurring among the four dimensions and across the two world regions. Surprisingly, it was found that in seven of the eight analyses the strongest predictor of satisfaction with the four dimensions of compensation satisfaction is job tenure, while actual compensation level, which was expected to be the strongest predictor, was found to be quite weak.

Research limitations/implications

A major weakness is that all of the data were self‐reported. Ideally the demographic and work‐related variables would have been collected directly from the organization in addition to being collected from employees. A second limitation is that the characteristics of the present sample may limit the generalizability of the results. An inordinate number of the subjects were unionized, female, and married. The major implication is that the paper supports the differential prediction for various dimensions of compensation satisfaction and for the need to explore for additional variables that can account for significant proportions of the variance in these dimensions.

Originality/value

The paper is the first of its kind to examine in a single or cross‐cultural setting the relationship between common demographic and work‐related factors and compensation satisfaction while controlling for organizational level. The literature review traverses the research in the area stretching from the 1940s to 2005 and makes specific suggestions for future research that could advance the field.
Building relationship with customers by using technological solutions in commercial banks of Latvia
Authors: Brige Andra
Published: June 2006

Purpose

This paper aims to give a short overview on bank/customer relationship experience in the Latvian banking system and the impact of developing technology in banking. Without usage of technology commercial banks cannot provide customers with effective services, but short banking history increases the danger of such a reduced loyalty towards the services supplier.

Design/methodology/approach

Literature studies, quantitative surveys combined with in‐depth interviews with bank customers and employees, and experts representing ITC sector.

Findings

Satisfaction with services provided is not the only factor influencing customer loyalty level. Customers experiencing a short banking history can be loyal to the service provider due to the lack of financial literacy. A great impact on loyalty level is made by other factors, such as: image, prestige, word of mouth, etc.

Research limitations/implications

The sample used for research did not include all 23 commercial banks of Latvia. Further research should be developed to compare customer loyalty levels in the more technologically developed and less technologically developed banks, and additional loyalty‐influencing determinants could be included.

Originality/value

An analysis of ITC development in banking side‐effects provides useful information not only for transitional countries but also for developing countries.
The Latvian market constructed
Authors: Borg Erik A.
Published: June 2006

Purpose

To identify essential building‐blocks in the construction of the Latvian market after the Latvian transition to a market economy.

Design/methodology/approach

The research uses a social constructivist approach to deconstruct the Latvian experience of economic change. The Latvian market is viewed as socially constructed, and essential events in the economic transition and national independence are viewed as essential to the interpretation of the Latvian experience of inclusion in the global economy.

Research limitations/implications

The research is limited to Latvia, but is portrayed against the change taking place in Eastern Europe and the Baltic States in particular.

Practical implications

The practical implications of this research are many, and could be taken into consideration not least by enterprises investing in the Latvian economy.

Originality/value

The value of the paper lies in the interpretations of the broader context of the Latvian market and some of the conditions in which enterprises are managed. The Latvian experience of transition is a background for reaching a better understanding of Latvian society.
Converging human resource management
Authors: Vanhala Sinikka , Kaarelson Tõnu , Alas Ruth
Published: June 2006

Purpose

The purpose of this paper is to participate in the convergence‐divergence debate related to the trends in European human resource management (HRM). The paper evaluates the converging vs diverging implications in Estonia and Finland by comparing HR strategies, policies and practices between the two countries in the context of HRM in the Nordic and EU‐15 countries.

Design/methodology/approach

The research is part of a large international comparative HRM project (CRANET), which covers over 30 countries. Empirical data were collected by a survey questionnaire mailed to large private and public organisations employing over 200 employees. The Estonian survey data involve 69 organisations and the Finnish data 269. The data cover private companies and public sector organisations.

Findings

The comparison of HRM in Estonia and Finland revealed a few interesting empirical observations: First, in spite of Estonia's short history as an independent Baltic state, HRM has stabilised its position at both strategic and policy level's as well as in HR practices. Second, there is a converging (directional) trend between Estonian and Finnish HRM. Third, the Estonian HRM matches with the EU‐15 HRM; Estonia does not increase diversity in the European HRM.

Research limitations/implications

The main limitation of the study is related to survey methodology. In further research longitudinal data as well as case studies and triangulation are needed to open country‐level trends in the convergence‐divergence debate.

Practical implications

Estonian companies and public organisations might need to pay more attention to equality/diversity policy. Special attention should be paid to HRM in public organisations.

Originality/value

The main value of the paper is related to the contribution to the convergence debate in HRM.
The company's involvement in international networks as an entrepreneurial decision
Authors: Roolaht Tõnu
Published: June 2006

Purpose

The purpose is to show the interconnections between the management style of an internationally expanding company and the pattern of its network connections, while incorporating the company size and corporate traditions as secondary determinants.

Design/methodology/approach

The paper uses multiple case study analysis. Included case studies characterise the various management attitudes of Estonian companies in engaging in international inter‐company relationships. To allow for the generalisation of results, the cases analyse the companies from several sectors and size groups.

Findings

Research concludes that the decision to participate in an international network could be made either because of socio‐economic circumstances or as the innovative entrepreneurial choice toward more rapid expansion. Thus, the paper views certain decisions of a company about its relationships with other agents, including suppliers and competitors, as entrepreneurial choices made by its general management. This research also categorises these choices as irreversible and temporary and positions company size and traditions as secondary factors, besides management style, which are important in determining the usage of relational support.

Research limitations/implications

The case study analysis might fail to illuminate the most archetypical features that could be generalized to all similar companies. Thus, one should exercise extreme caution when generalizing given results. In the case of qualitative research, the danger of misinterpretation of facts or events is bigger than in the case of quantitative research. The methodological variations make it more difficult to bring in cause and effect patterns.

Practical implications

These results imply the role and authority of an entrepreneur not only in multinational or ownership‐based networks but also in solely relational networks. This issue at present is not the subject of the research focus. The managers should also increasingly account for the impact of entrepreneurial management style in the corporate setting of takeovers and partnerships. Thus, innovative choices might achieve an increasingly important role in the formation of industrial networks.

Originality/value

This paper establishes the position of entrepreneurial management style as a determinant of partnership contacts, while controlling for company size and its management traditions. It offers case evidence about this entrepreneur‐led relationship building in Estonian companies.
From administrative humanism to the awareness of anomalies: the role of the human sciences
Authors: Cruz Kronfly Fernando
Published: June 2006

Purpose

The first purpose of this paper is to show that the so‐called “Administrative Humanitarian” is not a derivation from the “Human Science”. It is really derivated from “Antroprocentrismo” innocence, echo, at the same time from Geocentrismo. The second purpose of this paper is to explain why in the administrative humanitarian, while the human being in productive organization is, in a rhetoric way, “the center” of all, denies its essence on practices related to the act of work.

Design/methodology/approach

To support these two purposes, the paper suggests a brief presentation of the different “humanitarians” that really exist. Some of them, the “Christian Humanitarian” and the “Liberal Laïco Humanitarian” and other human sciences including organization studies before it goes through some considerations about the up‐to‐date promises, related to the cultural project of the “Administrative Humanitarian” and its ideal.

Findings

This paper is challenging traditional humanism and is denouncing discrepancies between discourses and action. If one observes the contemporary business world, one might conclude that the humanist paradigm in business administration is in crisis, since it is incapable of explaining the lack of correspondence between what is preached and what is practised in reality.

Originality/value

This paper belongs to a long tradition, which is still marginal is administrative science. This is why such a position should be important for further researches.
Technology management in China: a global perspective and challenging issues
Authors: Li‐Hua Richard , Khalil Tarek M.
Published: June 2006

Purpose

This paper reviews the framework of the management of technology (MOT) field and examines some application cases of technological development and innovation in China. It addresses various crucial issues necessary in the establishment of infrastructure, strategies, mechanisms and systems of technology management in China. It draws upon knowledge acquired from the US experience in this field for the past two decades.

Design/methodology/approach

An overview and conceptual paper based on observations and research experience.

Findings

This paper stresses the importance of keeping‐up with the fast pace of technological change and the emerging new global paradigms of the business environment. MOT is an important strategic instrument to improve competitiveness and create prosperity in countries that effectively apply it. The paper draws upon the experience of the US in MOT over the past two decades and projects what may be needed for China to continue its development and economic growth in the future. There is a need for appropriate infrastructures, strategies and mechanism to be established in order to support the diffusion of MOT principles throughout China. Educational institutions offering business and engineering education need to introduce MOT curricula following the US model or develop a new model shaped by the Chinese culture.

Originality/value

This paper presents the crucial tenets of technology management and provides some observations and insights on technology transfer, technology strategy and innovation process in China today. It suggests critical areas that decision makers in government agencies, enterprises and international funding agencies need to address with respect to MOT in China. Understanding the existing gaps in the process of technology management will assist in implementing more sustainable arrangement for successful technology transfer and development.
Northeast China – cradle of change
Authors: Sigurdson Jon
Published: June 2006

Purpose

The Northeast of the People's Republic of China is now termed the “rustbelt” of the country: there is a need to reform and restructure enterprises in the region. China's major industrialization is underway elsewhere, with factories located in coastal area and primarily oriented towards exports into global markets. In the meantime the original primary industrial base in Northeast has been almost been forgotten.

Design/methodology/approach

This preliminary mapping and tentative analysis of the Chinese rustbelt is based on intensive field interviews in three major cities in Northeast China – Dalian, Changchun and 1Harbin. The empirical results are complemented with official statistics and other government information. This research paper is a first attempt to take stock of the remaining technological and industrial structures that exist in the area and how they can become revitalized to service the overall economy.

Findings

This paper provides a preliminary examination of the possibility of using the region's strong higher education base to develop new high technology industries. It argues that this is a possible option for the future.

Originality/value

The information and analysis provides insights into a region of China not well‐known to the rest of the world, which has many challenges, but also many opportunities.
Innovation practices success in China: the use of innovation mechanisms in Chinese SOEs
Authors: Ren Liqin , Krabbendam Koos , de Weerd‐Nederhof Petra
Published: June 2006

Purpose

The climate for technical innovation has been improving in the past few years in China. This paper describes a case research concerning technical innovation practices success in three Chinese state‐owned enterprises (SOEs) in the manufacturing industry. This is executed by applying a technical innovation audit tool based on “Western” good practices.

Design/methodology/approach

Studies on technical innovation in the Chinese SOEs started in the 1990s, but most investigations in this field were based on statistical survey and mathematical modelling. In this research, case study research method, including such strategies as open‐ended, in‐depth questions, intensive interviews and observations, are applied for the validity of information.

Findings

The data and results reveal that the investigated Chinese SOEs have already some mechanisms for innovation in place. But there is still room for improvement and enhancement with respect to the effect on innovation success. It is also concluded that benchmarking (through the application of the technical innovation audit tool) does guide the Chinese management toward deciding which innovation mechanisms to adopt so as to provide the basics for innovation success. Additionally, based on the case studies the interesting conclusion could be drawn. In the context of the Chinese economy in transition, the case companies with less openness to the market (i.e. with high government involvement) have a more widespread use of innovation mechanisms.

Practical implications

The last finding seems to contradict the positive relationship between market focus and innovativeness as suggested in “Western” innovation management theories. For clarification we relate this to the way the SOEs deal with their adaptive cycle, thereby considering their way of dealing with (increased) complexity as compared to “Western” companies (complexity absorption versus reduction). The considered cases are embedded in the institutional setting of China in transition. Therefore, the conclusions and findings enrich the theory of transition by revealing the point that entering an open market abruptly may not be the solution for SOEs, which are rooted in a socialist economy, to become more competitive and more innovative. This was mostly elaborated through the influence of the two main stakeholders (i.e. government and customer/end‐user) on the openness of the SOEs and their use of innovation mechanisms in China, the largest socialist system of the world.

Originality/value

This paper is based on a doctoral research project, containing reliable, first hand data from the practice.
Exploring sources of competitive advantage
Authors: Matthew Hinton C. , Tao Yan
Published: June 2006

Purpose

To investigate the key sources of competitive advantage gained from e‐business applications by Chinese real estate developers and whether the value chain theory and its related theories can explain this phenomenon.

Design/methodology/approach

A key issue in e‐business is how established companies can gain competitive advantage. Despite the interest in e‐business applications, few empirical studies have been carried out to look at how “clicks‐and‐mortar” approaches offer competitive advantages, especially from specific industry perspectives. By using a qualitative case study approach this study addresses this.

Findings

The study shows that the value chain framework is useful to identify and categorize possible e‐business application areas. Moreover, this categorization makes identification of key sources of competitive advantage explicit. However, this framework cannot fully explain the success of e‐business applications nor the realization of intended motivations.

Research limitations/implications

Further research is needed to make the value chain model become an easily‐used, practical guideline for e‐business implementation. This study has focussed on one specific industry within China (centre on real estate) so generalisation to other industries is limited at this stage. Similar research in other sectors will go a long way to addressing this.

Practical implications

Offers organizations a theoretical framework which helps to support the identification of appropriate e‐business applications. Furthermore, it closes the gap between strategic direction and subsequent system implementation.

Originality/value

This paper provides empirical evidence of how established organizations gain competitive advantage through their e‐business applications. Furthermore, it offers insight into how value chain theory helps to explain this phenomenon within the context of ongoing changes within the Chinese economy.
Executive insight: evaluating the market size for service franchising in emerging markets
Authors: Alon Ilan
Published: June 2006

Purpose

The purpose of this article is to propose a framework for analyzing the comparative economic market size for service franchisors in emerging markets using current and available data from the World Bank.

Design/methodology/approach

Data is transformed through simple manipulations to derive information‐filled rankings of 20 popular emerging markets. Emerging markets constitute the largest and most dynamic markets for international franchisors.

Findings

The findings show that Brazil, Russia, and Mexico outranked China and India as the markets with the largest economies for service franchising. Future research should enhance the economic analysis and measures developed in the article and use them in conjunction with other environmental, industry, and company variables to estimate the market potential and select the appropriate markets for entry.

Practical implications

Attempting to estimate the market size of emerging markets is often only the first step in international market selection.

Originality/value

This paper encourages managers to think beyond simple measures of market size when considering the attractiveness of franchising opportunities which hitherto has been under‐emphasized in the extant literature.
The impact of group membership on knowledge sharing in Russia and China
Authors: Hutchings Kate , Michailova Snejina
Published: June 2006

Purpose

To explore the contention that, contrary to earlier research suggesting that people in transition economies such as Russia and China have a propensity not to share knowledge, Russians' and Chinese' may in fact be more inclined to share knowledge than people in Western, industrialised countries but that this willingness to share knowledge is highly influenced by group membership.

Design/methodology/approach

Our argument is based on reviews of previous literature and cases and the authors' own semi‐structured interview research conducted with Western and local managers and employees in Russia and China over the past decade.

Findings

The research finds that the extent to which group membership influences the processes of knowledge sharing and whether it is impeded or facilitated in Russia and China is determined by both cultural and institutional factors.

Practical implications

The paper has important practical implications in providing guidelines on the initiatives that international businesses can implement to create knowledge‐sharing organizational cultures in their subsidiary operations in Russia and China.

Originality/value

The research is original and adds value to existing literature in that we examine an issue erstwhile not explored in mainstream organizational writings, namely an in‐depth consideration of the relationship between groups and knowledge sharing, with particular reference to two emerging markets.
Progress in the development of guidance strategies for the landing flare manoeuvre using tau‐based parameters
Authors: Jump Michael , Padfield Gareth D.
Published: June 2006

Purpose

To provide a progress report into research conducted to establish guidelines for the development of guidance vision aids.

Design/methodology/approach

The first stage of the research is to establish a coherent engineering basis for the methods of (visual) motion perception and control to inform the design of pilot aids that will support flight in degraded visual conditions, particularly when close to the ground. The next stage will then be to construct and evaluate synthetic displays that recover the visual cues necessary to allow flight in degraded visual conditions for a range of manoeuvres using the flight simulation facilities at the University of Liverpool (UoL). The research is guided by tau (time to contact) theory from the field of ecological psychology.

Findings

The closure of spatial gaps for a number of aircraft manoeuvres are presented in the tau domain. Analysis of the landing flare manoeuvre suggest that both a constant rate of change of tau strategy and an intrinsic tau‐guidance strategy will yield benefits in terms of touchdown descent rate if presented as display symbology.

Research limitations/implications

Results are presented from trials where only one professional pilot was used. Results from a wider population of pilots need to be analysed to ensure that the observed trends are generic.

Practical implications

The reported results are being used in the next phase of the research project to inform the design of a guidance vision‐aid for the flare manoeuvre. These displays will be tested in flight simulation trials.

Originality/value

The research takes a theory of motion perception and applies it to aircraft guidance display technology.
The helicopter – efficiency or efficacy?
Authors: Newman Simon
Published: June 2006

Purpose

This paper reflects the design characteristics of helicopters and how each addresses the requirements of efficiency in operation and the ability to perform these operations effectively.

Design/methodology/approach

The basic requirements of a helicopter are discussed. A survey of the various rotorcraft configurations follows. A brief perusal of possibilities for the future concludes the paper.

Findings

The helicopter appears in various guises. Each version is designed to a particular brief and fulfils its own particular purpose.

Originality/value

The paper content is generally available from the various rotary wing texts both in print and within libraries. The originality comes from the assembly of these items within one paper which attempts to highlight the particular difficulties faced when designing rotary wing aircraft.
The influence of human factors on operational efficiency
Authors: Harris Don
Published: June 2006

Purpose

To describe how airline operational efficiency may be improved by adopting a socio‐technical systems approach which emphasises and integrates the role of human factors within a wider context.

Design/methodology/approach

After describing what is meant by a socio‐technical system, the paper uses four short case studies to illustrate the benefits and dis‐benefits of using (or failing to use) a socio‐technical systems approach.

Findings

Readers are encouraged to acknowledge the role of the human being in a wider system context. It is also suggested that improving individual aspects of airline operations in isolation may not actually improve overall efficiency.

Research/limitations/implications

The case studies discussed are meant to be illustrative of the socio‐technical systems approach rather than an authoritative review of the area.

Practical implications

The practical implications of adopting a socio‐technical systems view of improvements aimed at improving efficiency are emphasised in that with early consideration of system changes bottlenecks may be identified which will reduce the efficacy of these changes.

Originality/value

Possibly the first attempt at providing a wider socio‐technical systems framework for the assessment of operational efficiency explicitly incorporating the role of the human in the system.
Measuring operational safety in aviation
Authors: Rose Andrew
Published: June 2006

Purpose

The paper seeks to outline the limitations and constraints in measuring operational safety in an aviation environment and provide an overview of the work being done at British Airways to overcome them.

Design/methodology/approach

The paper looks at the limitations and problems of trying to measure safety and operational risk. These limitations are then discussed along with methodologies to overcome them. The paper then describes some of the methods being tried within British Airways to provide useful measures of risk whilst trying to avoid the problems identified previously.

Findings

The findings of the work are that there are potential ways to generate useful safety metrics from incident reporting data and that the best use of risk data is to focus attention within the organisation onto areas of risk that need to be addressed.

Practical implications

The paper is based on practical work being undertaken at British Airways, and therefore, is demonstrated to be practical in an aviation environment.

Originality/value

The drive for operational efficiency in aviation means that aircraft operations are increasingly run against a backdrop of measures and targets. This in turn generates an increasing need and desire to include safety as a metric that can be tracked and monitored. This paper is focussed on meeting that desire and ensuring that any metrics developed avoid, as far as practical, the problems of measuring safety and using it to drive operational performance.
The operational efficiency of passenger aircraft
Authors: McLean Donald
Published: June 2006

Purpose

To provide for the use of airlines and other civil aviation organizations a practical definition of operational efficiency and to show how it can be determined.

Design/methodology/approach

A brief account of air transport economics is used to demonstrate how bom load factors and aircraft utilization need to be considered in assessing operational efficiency. Then other efficiencies are treated briefly before an example is given of how the better of two fictitious aircraft can be chosen for a particular route. A second example involving the calculation of the operational efficiency achieved by an imaginary airline is also given to show that the typical value is lower than might be expected, particularly in view of the relatively high load factors involved.

Findings

Provides performance values and economic figures which are typical of current airline operations.

Practical implications

Use of the proposed definition will allow the consistent assessment of the economic performance of airlines.

Originality/value

At present there is no definition of operational efficiency in general use although it is greatly needed by airlines. The definition proposed in this paper is practical and easy to use.
CIRSE: A solvation energy estimator compatible with flexible protein docking and design applications
Authors: Cerutti David S. , Jain Tushar , McCammon J. Andrew
Published: June 2006

We present the Coordinate Internal Representation of Solvation Energy (CIRSE) for computing the solvation energy of protein configurations in terms of pairwise interactions between their atoms with analytic derivatives. Currently, CIRSE is trained to a Poisson/surface‐area benchmark, but CIRSE is not meant to fit this benchmark exclusively. CIRSE predicts the overall solvation energy of protein structures from 331 NMR ensembles with 0.951 ± 0.047 correlation and predicts relative solvation energy changes between members of individual ensembles with an accuracy of 15.8 ± 9.6 kcal/mol. The energy of individual atoms in any of CIRSE's 17 types is predicted with at least 0.98 correlation. We apply the model in energy minimization, rotamer optimization, protein design, and protein docking applications. The CIRSE model shows some propensity to accumulate errors in energy minimization as well as rotamer optimization, but these errors are consistent enough that CIRSE correctly identifies the relative solvation energies of designed sequences as well as putative docked complexes. We analyze the errors accumulated by the CIRSE model during each type of simulation and suggest means of improving the model to be generally useful for all‐atom simulations.
Sequence of events in folding mechanism: Beyond the Gō model
Authors: Sutto Ludovico , Tiana Guido , Broglia Ricardo A.
Published: June 2006

Simplified Gō models, where only native contacts interact favorably, have proven useful to characterize some aspects of the folding of small proteins. The success of these models is limited by the fact that all residues interact in the same way so that the folding features of a protein are determined only by the geometry of its native conformation. We present an extended version of a Cα‐based Gō model where different residues interact with different energies. The model is used to calculate the thermodynamics of three small proteins (Protein G, Src‐SH3, and CI2) and the effect of mutations (ΔΔGU‐N, ΔΔG‡‐N, ΔΔG‡‐U, and φ‐values) on the wild‐type sequence. The model allows us to investigate some of the most controversial areas in protein folding, such as its earliest stages and the nature of the unfolded state, subjects that have lately received particular attention.
A limited universe of membrane protein families and folds
Authors: Oberai Amit , Ihm Yungok , Kim Sanguk , Bowie James U.
Published: June 2006

One of the goals of structural genomics is to obtain a structural representative of almost every fold in nature. A recent estimate suggests that 70%–80% of soluble protein domains identified in the first 1000 genome sequences should be covered by about 25,000 structures—a reasonably achievable goal. As no current estimates exist for the number of membrane protein families, however, it is not possible to know whether family coverage is a realistic goal for membrane proteins. Here we find that virtually all polytopic helical membrane protein families are present in the already known sequences so we can make an estimate of the total number of families. We find that only ∼700 polytopic membrane protein families account for 80% of structured residues and ∼1700 cover 90% of structured residues. While apparently a finite and reachable goal, we estimate that it will likely take more than three decades to obtain the structures needed for 90% residue coverage, if current trends continue.
Structural studies of human alkaline phosphatase in complex with strontium: Implication for its secondary effect in bones
Authors: Llinas Paola , Masella Michel , Stigbrand Torgny , Ménez André , Stura Enrico A. , Le Du Marie Hélène
Published: June 2006

Strontium is used in the treatment of osteoporosis as a ranelate compound, and in the treatment of painful scattered bone metastases as isotope. At very high doses and in certain conditions, it can lead to osteomalacia characterized by impairment of bone mineralization. The osteomalacia symptoms resemble those of hypophosphatasia, a rare inherited disorder associated with mutations in the gene encoding for tissue‐nonspecific alkaline phosphatase (TNAP). Human alkaline phosphatases have four metal binding sites—two for zinc, one for magnesium, and one for calcium ion—that can be substituted by strontium. Here we present the crystal structure of strontium‐substituted human placental alkaline phosphatase (PLAP), a related isozyme of TNAP, in which such replacement can have important physiological implications. The structure shows that strontium substitutes the calcium ion with concomitant modification of the metal coordination. The use of the flexible and polarizable force‐field TCPEp (topological and classical polarization effects for proteins) predicts that calcium or strontium has similar interaction energies at the calcium‐binding site of PLAP. Since calcium helps stabilize a large area that includes loops 210–228 and 250–297, its substitution by strontium could affect the stability of this region. Energy calculations suggest that only at high doses of strontium, comparable to those found for calcium, can strontium substitute for calcium. Since osteomalacia is observed after ingestion of high doses of strontium, alkaline phosphatase is likely to be one of the targets of strontium, and thus this enzyme might be involved in this disease.
Platelet‐dependent thrombography: a method for diagnostic laboratories
Authors: Dargaud Yesim , Luddington Roger , Baglin Trevor
Published: June 2006

The thrombin‐platelet feedback loop was examined at low concentration tissue factor using calibrated automated thrombography in combination with the elimination of contact factor activation by corn trypsin inhibitor. The results indicated that, when contact factor activation was eliminated, the thrombin‐platelet feedback loop was a major determinant of thrombin generating capacity and that platelets had a greater role in regulating the propagation of thrombin generation than its initiation. This method has potential application to the measurement of platelet‐dependent thrombin generation in clinical diagnostic laboratories and hence the investigation of patients with apparent hypo‐ or hypercoagulable phenotypes.
Self‐potential data interpretation using standard deviations of depths computed from moving‐average residual anomalies
Authors: Abdelrahman E.M. , Essa K.S. , Abo‐Ezz E.R. , Soliman K.S.
Published: June 2006

We have developed a least‐squares minimization approach to determine simultaneously the shape (shape factor) and the depth of a buried structure from self‐potential (SP) data. The method is based on computing the standard deviation of the depths determined from all moving‐average residual anomalies obtained from SP data, using filters of successive window lengths for each shape factor. The standard deviation may generally be considered a criterion for determining the correct depth and shape factor of the buried structure. When the correct shape factor is used, the standard deviation of the depths is less than the standard deviations computed using incorrect shape factors. This method is applied to synthetic data with and without random errors, complicated regionals and interference from neighbouring sources, and is tested on a known field example from Turkey. In all cases, the shape and depth solutions obtained are in a good agreement with the actual values.
Linear demultiple solution based on the concept of bottom‐multiple‐generator (BMG) approxiamtion: some new results
Authors: Oladeinde Abiola O. , Ikelle Luc T.
Published: June 2006

Recent advances in the demultiple technique have shown that a multidimensional convolution of a portion of data containing only primaries with the whole data (containing both primaries and multiples) can allow us to predict and attenuate all orders of free‐surface multiples that are relevant for practical purposes. One way of constructing the portion of the data containing only primaries is by muting the actual data just above the first free‐surface multiple to arrive. The location of the mute is generally known as the bottom‐multiple‐generator (BMG) reflector; the portion of the data containing only primaries required for constructing the free‐surface multiples is located above the BMG. The outstanding question about this method is how effective can the technique be when the BMG cuts through several seismic events, as is the case in long‐offset data or in very complex shallow geology. We present new results which demonstrate the fact that the BMG location may cut through several seismic events without affecting the accuracy or the cost of demultiple.
Electromagnetic fields in a non‐uniform steel‐cased borehole
Authors: Kim Hee Joon , Lee Ki Ha
Published: June 2006

Since most oil wells are cased in steel, electromagnetic (EM) signals undergo severe attenuation as they diffuse across the casing. This paper examines an effect of non‐uniform casing properties on EM fields measured in a steel‐cased well embedded in a layered formation. We use a finite‐element method for computing secondary azimuthal electric fields in a cylindrically symmetric model, and analytically obtain primary fields for a homogeneous casing in a homogeneous whole space. Although steel casing largely masks EM signals induced into a layered formation, the induced signal is more pronounced in phase than in amplitude. The effect of casing non‐uniformity is quite large in measured fields but is highly localized. When electrical conductivity varies rapidly in the casing wall, the resulting EM fields also vary rapidly. A cross‐correlation function of these variations has strong peaks at two points, the interval between them being equal to the source–receiver distance. The high‐frequency coherent noise event caused by the non‐uniform casing can be greatly suppressed by low‐pass filtering to enhance EM signals indicating formation conductivity.
Theory and seismic applications of the eigenimage discrete wavelet transform
Authors: Droujinine Alexander
Published: June 2006

Discrete wavelet transforms are useful in a number of signal processing applications. To improve the scale resolution, a joint function of time, scale and eigenvalue that describes the energy density or intensity of a signal simultaneously in the wavelet and eigenimage domains is constructed. A hybrid method, which decomposes eigenimages in the wavelet domain, is developed and tested on field data with a variety of noise types. Several illustrative examples examine the ability of wavelet transforms to resolve features at several scales. Successful applications to time‐lapse seismic reservoir monitoring are presented. In reservoir monitoring, the scale‐dependent properties of the eigenstructure of the 4D data covariance matrix enable us to extract the low‐frequency time‐lapse signal that is the result of internal diffusive losses caused by fluid flow.
Theoretical development of the differential scattering decomposition for the 3D resistivity experiment
Authors: Oldenborger Greg A. , Routh Partha S.
Published: June 2006

In any numerical solution of the DC resistivity experiment, care must be taken to deal with strong heterogeneity of electrical conductivity. In order to examine the importance of conductivity contrasts, we develop a scattering decomposition of the DC resistivity equation in the sparse differential domain as opposed to the traditional dense integral formulation of scattering‐type equations. We remove the singularity in the differential scattered series via separation of primary and secondary conductivity, thereby avoiding the need to address the singularity in a Green's function. The differential scattering series is observed to diverge for large conductivity contrasts and to converge for small contrasts. We derive a convergence criterion, in terms of matrix norms for the weak‐form finite‐volume equations, that accounts for both the magnitude and distribution of heterogeneity of electrical conductivity. We demonstrate the relationship between the differential scattering series and the Fréchet derivative of the electrical potential with respect to electrical conductivity, and we show how the development may be applied to the inverse problem. For linearization associated with the Fréchet derivative to be valid, the perturbation in electrical conductivity must be small as defined by the convergence of the scattered series. The differential scattering formulation also provides an efficient tool for gaining insight into charge accumulation across contrasts in electrical conductivity, and we present a derivation that equates accumulated surface charge density to the source of scattered potential.
The human renal lymphatics under normal and pathological conditions
Authors: Ishikawa Y , Akasaka Y , Kiguchi H , Akishima‐Fukasawa Y , Hasegawa T , Ito K , Kimura‐Matsumoto M , Ishiguro S , Morita H , Sato S , Soh S , Ishii T
Published: June 2006

Aims:  The renal lymphatics have not been fully documented in humans. The aim of this study was to clarify the morphology of the human renal lymphatic system under normal and pathological conditions by immunohistochemistry using anti‐D2‐40 antibody.

Methods and results:  Normal and pathological renal tissues obtained at autopsy as well as nephrectomy specimens with renal cell carcinoma (RCC) were used. Thin sections were immunostained with antibodies against D2‐40 and CD31. In normal kidney, D2‐40+ lymphatics were abundant in the interstitium around the interlobar and arcuate arteries/veins but sporadic in those around the glomeruli or between the tubules in the cortex. A few lymphatics contained erythrocytes in their lumina. Lymphatics were seldom present in the medulla. In RCC cases, lymphatics were evident at the tumour margin, whereas CD31+ capillaries were abundant throughout the tumour and lymphatics were increased in the fibrous interstitium around the tumour. Lymphatic invasion by RCC cells was also detectable. D2‐40+ lymphatics were evident in other pathological conditions and end‐stage kidney had a denser lymphatic distribution than normal kidney.

Conclusions:  Lymphatics are abundant around the arteries/veins and are also present in the renal cortex and medulla. D2‐40 immunostaining is helpful for investigating the pathophysiological role of renal lymphatics.