bluuebunny/crossref_metadata_2025 huggingface dataset:
Book Reviews
Authors: Lev Benjamin
Published: December 2006

The range of books reviewed is wide, covering theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems (no software is reviewed). In addition, we include books in other fields that emphasize technical applications. Publishers who wish to have their books reviewed should send them to Professor Benjamin Lev. We list the books received; not all books received can be reviewed because space is limited. Those who would like to review books are urged to send me their names, addresses, and specific areas of expertise. We commission all reviews and do not accept unsolicited book reviews. Readers are encouraged to suggest books that might be reviewed or to ask publishers to send me copies of such books.

The authors or editors of the books reviewed in this issue are Kenneth R. Baker, Wai-Ki Ching, Michael K. Ng, Manuel Laguna, Rafael Marti, J. Cole Smith, and Jan A. Snyman.
IBM Solves a Mixed-Integer Program to Optimize Its Semiconductor Supply Chain
Authors: Denton Brian T. , Forrest John , Milne R. John
Published: December 2006

IBM Systems and Technology Group uses operations research models and methods extensively for solving large-scale supply chain optimization (SCO) problems for planning its extended enterprise semiconductor supply chain. The large-scale nature of these problems necessitates the use of computationally efficient solution methods. However, the complexity of the models makes developing robust solution methods a challenge. We developed a mixed-integer programming (MIP) model and supporting heuristics for optimizing IBM’s semiconductor supply chain. We designed three heuristics, driven by practical applications, for capturing the discrete aspects of the MIP. We leverage the model structure to overcome computational hurdles resulting from the large-scale problem. IBM uses the model and method daily for operational and strategic planning decisions and has saved substantial costs.
Tactical Prevention of Suicide Bombings in Israel
Authors: Kaplan Edward H. , Mintz Alex , Mishal Shaul
Published: December 2006

Suicide bombings are the leading cause of death from terrorism in Israel. Counterterror tactics, such as the targeted killings or preemptive arrests of terror leaders or suspects, are meant to prevent such attacks. To investigate whether these tactics are successful, we estimated via maximum likelihood a family of shot-noise models from monthly data covering 2001 through 2003 to see whether we could predict the rate of suicide-bombing attacks as a function of prevention tactics over time. Although preventive arrests appear to lower the rate of suicide-bombing attacks, targeted killings seem to be followed by an increase in the number of suicide bombings. In addition, limited evidence suggests that the probability of intercepting a suicide bomber en route to an attack increases with the expected number of suicide-bombing attacks. Such an endogenous relationship could imply an upper limit on the rate of successful suicide bombings.
A Survey of Operations Research Models and Applications in Homeland Security
Authors: Wright P. Daniel , Liberatore Matthew J. , Nydick Robert L.
Published: December 2006

Operations research has had a long and distinguished history of work in emergency preparedness and response, airline security, transportation of hazardous materials, and threat and vulnerability analysis. Since the attacks of September 11, 2001 and the formation of the US Department of Homeland Security, these topics have been gathered under the broad umbrella of homeland security. In addition, other areas of OR applications in homeland security are evolving, such as border and port security, cyber security, and critical infrastructure protection. The opportunities for operations researchers to contribute to homeland security remain numerous.
Developing a Customized Decision-Support System for Brand Managers
Authors: Wierenga Berend , Van Bruggen Gerrit H.
Published: December 2006

Working with brand managers at Holland Fast Moving Company (HFMC), we designed a marketing-management-support system, BRANDFRAME. In conducting the project, we (1) examined the decision situation; (2) examined the existing marketing-management-support system; (3) determined what type of decision support best fits the tasks of the brand managers; (4) developed and implemented the software; (5) obtained feedback from the managers who worked with the software; and (6) adapted and extended the system. BRANDFRAME contains a combination of academic and practical knowledge and integrates all the information needed by the brand manager in one system. The system does not replace the brand manager but, in an interactive way, acts as a sparring partner. The system was very well received by the managers who worked with it and has shown that customizing decision-support systems for specific marketing jobs (in this case, the brand manager) may well be an important factor for the success of marketing-management-support systems.
Building Marketing Models that Make Money
Authors: Lodish Leonard M.
Published: December 2006

Building models that help marketers make productive decisions and that they actually use is hard. I learned some lessons in my 30+ years of building and applying models for sizing and deploying sales forces, for estimating brand health, and for estimating the impact on revenue of marketing mix and of the attractiveness to consumers of product attributes. One is that building scientific models that improve productivity is an art. Other lessons include these: to balance model complexity versus ease of understanding and estimation; to involve managers in any subjective estimates for models they will implement; to make measures available to managers when they need them and at the level of organization they need; to use the predictive validity of a hold-out sample to persuade managers of a model's credibility; and to recognize that even for empirical models, subjective estimates about the future may be necessary. Productive marketing models may have different attributes than those published in prestigious academic journals.
Practice Abstract
Authors: Keefer Donald L. , Parnell Gregory S.
Published: December 2006

Practice Abstracts carries short reports of specific current or recent OR/MS projects. Often these reports are based on existing documents, such as internal reports or company newsletters. We hope that these abstracts will be accessible, interesting, and valuable to practitioners in other organizations. Contributions should be sent for evaluation to the editor of “Practice Abstracts,” Donald L. Keefer, Department of Supply Chain Management, Arizona State University, Box 874706, Tempe, Arizona 85287-4706 [don.keefer@asu.edu].
An Analysis of the Applications of Neural Networks in Finance
Authors: Fadlalla Adam , Lin Chien-Hua
Published: December 2006

Over the last 10 years, neural networks have been increasingly applied to various areas of finance. Neural networks are more often applied on the assets side than on the liabilities side of the balance sheet. Some major characteristics of the areas of these applications are their data intensity, unstructured nature, high degree of uncertainty, and hidden relationships. Most of the applications use the backpropagation model with one hidden layer. In most of these applications, neural networks out-performed traditional statistical models, such as discriminant and regression analysis. Furthermore, these applications have shown significant success in financial practice, for example, in forecasting T-bills, in asset management, in portfolio selection, and in fraud detection.
The Spanish Government Uses a Discrete Multicriteria DSS to Determine Data-Processing Acquisitions
Authors: Barba-Romero Sergio
Published: December 2006

Since 1983, all acquisitions of data-processing equipment, consulting services, and software by the central public administration offices in Spain must be evaluated and approved by a high-level governmental commission. This commission relies on a discrete multicriteria methodology I developed and subsequently collaborated in implementing into a decision support system. The decision support system allows three different evaluations and normalization procedures to prevent suppliers from performing their customary strategic manipulations. It can conduct domination and satisfaction preanalyses, it offers four different aggregation methods, and it performs several sensitivity analyses.
Intermodal Pricing Model Creates a Network Pricing Perspective at BNSF
Authors: Gorman Michael F.
Published: December 2006

Burlington Northern and Santa Fe Railway (BNSF) is exploring methods of pricing its network of intermodal services effectively. The problem is challenging because cost interactions between the markets arise from equipment imbalances at end-points in the network. The intermodal pricing model takes a global perspective when establishing market prices to improve network profitability. Accounting for the vagaries of market-place demand proved to be critical to gaining management's confidence in the plausibility of model results. BNSF has applied the model to many pricing scenarios. In the application I describe, I identified a potential for 3.5 percent improvement in net profitability through a 61 percent reduction in empty repositioning. Since 1998, BNSF has increased loaded miles by five percent and simultaneously reduced repositioning by three percent per year.
Using Simulation to Increase Efficiency in an Army Recruitment Office
Authors: Shtrichman Ofer , Ben-Haim Rami , Pollatschek Moshe A.
Published: December 2006

The Israeli army used queuing analysis, simulation, and decision-support modeling to redesign its recruitment procedures. The analysis and simulation helped it to achieve significant savings and improvements in quality of service. Simulation was the key technique used to evaluate the various possible strategies, and it helped management to visualize their potential benefits. The application of these methods in the service sector, which deals with people rather than assembled parts, was the main challenge in this project.
New York Power Authority Uses Decision Analysis to Schedule Refueling of Its Indian Point 3 Nuclear Power Plant
Authors: Dunning Dennis J. , Lockfort Steve , Ross Quentin E. , Beccue Phillip C. , Stonebraker Jeffrey S.
Published: December 2006

The New York Power Authority (NYPA) wanted to develop a 10-year schedule for refueling its Indian Point 3 Nuclear Power Plant (IP3) that balanced fish protection, which occurs when IP3 is shut down for refueling, and the costs of buying and loading fuel. We developed a decision analysis model to compare alternative strategies for refueling. It explicitly considered key uncertainties associated with future operation: how well IP3 operates, how long it takes to refuel, and when New York State is likely to deregulate the electric utility industry. The NYPA decision makers used the model to reinforce their choice of a refueling strategy. They were not surprised that more fish protection occurred with strategies that restricted the starting date for refueling to the third week in May, rather than allowing the starting date to float throughout the period from May through August. However, the decision makers were surprised that the more restrictive strategies also resulted in lower costs.
Saving Federal Travel Dollars
Authors: Huisingh Jeffrey L. , Yamauchi Harold M. , Zimmerman Randy
Published: December 2006

Federal employees frequently travel to professional-development conferences and training events. Conference planners often decide on event locations arbitrarily with little regard for travel cost. We developed a method for evaluating travel costs and determining the least expensive conference site from over 261 US cities with government-contracted air-fares. It involves using the relaxation method for solving the noncapacitated shortest-path-network problem and computing interairport distances using latitude and longitude data. A decision support tool called OffSite allows conference planners to assess collective travel costs for attendees arriving from geographically dispersed locations. Event planners input a list of origin cities for conference participants, and OffSite then determines the lowest-cost location. This tool can restrict the search for meeting venues to the origin locations of potential hosts for the conference. In addition, OffSite is flexible enough to allow planners to choose a preferred destination.
Determinants of Success of German Venture Capital Investments
Authors: Schefczyk Michael
Published: December 2006

Based on literature reviews, I formulated 10 hypotheses for a wide range of determinants of success for German venture capital firms (VCFs). I tested and largely confirmed these hypotheses using bivariate correlation analyses and confirmatory multivariate LISREL models on a data set of 103 transactions by 12 German VCFs. The analyses indicate that emphasizing portfolio companies' managers' qualifications, intensifying cooperation between VCFs and portfolio companies, and ensuring a strong (minority) shareholder position of the VCFs coincide with above average success.
Jeppesen Uses a Dynamic-Programming-Based DSS to Manage Inventory
Authors: Katok Elena , Lathrop Andrew , Tarantino William , Xu Susan H.
Published: December 2006

We developed a system for managing inventory at Jeppesen Sanderson, Inc., a major provider of aviation-information products. The system determines order quantities for charts used in flight manuals. These charts contain essential safety information that changes frequently, making standard methods for inventory management ineffective. We formulated the problem as a dynamic programming model and developed a simple heuristic-solution procedure for determining order quantities. Based on this procedure, we also developed a decision support system (DSS) and implemented it for 600 of the most expensive Jeppesen charts. The system has been in use since August 1998, generating actual annual cost reductions of over $800,000.
The Practice of Operations Research and the Role of Practice and Practitioners in INFORMS
Authors: Murphy Frederic H.
Published: December 2006

Effective practice involves the interplay of technical knowledge, organizational knowledge, and interpersonal skills. This mix of skills plus the business imperatives and social structure of practice creates problems for the role of practice in INFORMS. Mapping the skills and knowledge required for practice and the competencies in INFORMS as a professional society provides a structure for understanding how practice fits into INFORMS and how to resolve some of the issues in providing a proper role for INFORMS in making a community for practitioners. The same structure also illustrates what is different about teaching operations research in business schools versus engineering schools or mathematics departments. Although we work in a technical area, we need to understand the sociology and market structure of practice, major elements in developing a theory of practice.
Market Power and Power Markets
Authors: Weiss Jürgen
Published: December 2006

Market power is a prominent issue in the current debate about electricity industry restructuring. Market experiments I conducted with industry subjects via the Internet show the impact of seller concentration, demand-side bidding, and transmission constraints on competition in simulated electricity markets. Realistic modeling of the transmission grid revealed opportunities to exercise market power not found in simpler experimental designs. In particular, increasing the number of sellers in a market did not necessarily reduce market power as standard theory suggests. Rather, locational advantages allowed some players to maintain profits near monopoly levels even when seller concentration was at levels generally considered competitive. The implication is that divestiture of existing local monopolies may not be enough to make electricity markets competitive. I confirm the positive impact of demand-side bidding on competition.
Managing Increasing Product Variety at Integrated Steel Mills
Authors: Denton Brian , Gupta Diwakar , Jawahir Keith
Published: December 2006

Intense market competition in recent years has made it increasingly important for integrated steel mills (ISMs) to differentiate themselves from competitors based on customer service, two key attributes of which are the duration and the reliability of order-fulfillment time. To improve responsiveness, some ISMs are shifting from a pure make-to-order system toward a hybrid make-to-stock, make-to-order system. They can then match certain customer orders to existing semifinished inventory, thereby reducing the time it takes to fill those orders. However, choosing which semifinished products to make to stock and how to manage their inventory are difficult problems. We developed an optimization model that one ISM implemented as a decision-support tool for choosing the designs of made-for-stock (MFS) slabs. Use of the model has reduced the number of MFS slab designs and increased the proportion of orders covered by those designs.
Research Note: Individual Cognition and Dual-Task Interference in Group Support Systems
Authors: Heninger William G. , Dennis Alan R. , Hilmer Kelly McNamara
Published: December 2006

Previous research shows that synchronous text discussion through group support systems (GSS) can improve the exchange of information within teams, but this improved information exchange usually does not improve decisions because participants fail to process the new information they receive. This study examined one potential cause for this failure: Dual-task interference caused by the need to concurrently process new information from others while also contributing one’s own information to the discussion. Although prior research argues that dual-task interference should be minimal, we found that it significantly reduced participants’ information processing and led to lower decision quality. The effect sizes were large, suggesting that dual-task interference is one of a handful of major factors that exert the greatest influence on information processing and decision-making performance. We believe that these results call for an increased emphasis on and understanding of the cognitive underpinnings of GSS and virtual team decision making.
Perceived Information Quality in Data Exchanges: Effects on Risk, Trust, and Intention to Use
Authors: Nicolaou Andreas I. , McKnight D. Harrison
Published: December 2006

This study examines the role of information quality in the success of initial phase interorganizational (I-O) data exchanges. We propose perceived information quality (PIQ) as a factor of perceived risk and trusting beliefs, which will directly affect intention to use the exchange. The study also proposes that two important system design factors—control transparency and outcome feedback—will incrementally influence PIQ. An empirical test of the model demonstrated that PIQ predicts trusting beliefs and perceived risk, which mediate the effects of PIQ on intention to use the exchange. Thus, PIQ constitutes an important indirect factor influencing exchange adoption. Furthermore, control transparency had a significant influence on PIQ, while outcome feedback had no significant incremental effect over that of control transparency. The study contributes to the literature by demonstrating the important role of PIQ in I-O systems adoption and by showing that information cues available to a user during an initial exchange session can help build trusting beliefs and mitigate perceived exchange risk. For managers of I-O exchanges, the study implies that building into the system appropriate control transparency mechanisms can increase the likelihood of exchange success.
Formulating the Data-Flow Perspective for Business Process Management
Authors: Sun Sherry X. , Zhao J. Leon , Nunamaker Jay F. , Sheng Olivia R. Liu
Published: December 2006

Workflow technology has become a standard solution for managing increasingly complex business processes. Successful business process management depends on effective workflow modeling and analysis. One of the important aspects of workflow analysis is the data-flow perspective because, given a syntactically correct process sequence, errors can still occur during workflow execution due to incorrect data-flow specifications. However, there have been only scant treatments of the data-flow perspective in the literature and no formal methodologies are available for systematically discovering data-flow errors in a workflow model. As an indication of this research gap, existing commercial workflow management systems do not provide tools for data-flow analysis at design time. In this paper, we provide a data-flow perspective for detecting data-flow anomalies such as missing data, redundant data, and potential data conflicts. Our data-flow framework includes two basic components: data-flow specification and data-flow analysis; these components add more analytical rigor to business process management.
Research Note: The Influence of Recommendations and Consumer Reviews on Evaluations of Websites
Authors: Kumar Nanda , Benbasat Izak
Published: December 2006

Recommendations and consumer reviews are universally acknowledged as significant features of a business-to-consumer website. However, because of the well-documented obstacles to measuring the causal impact of these artifacts, there is still a lack of empirical evidence demonstrating their influence on two important outcome variables in the shopping context: perceived usefulness and social presence. To test the existence of a causal link between information technology (IT)-enabled support for the provision of recommendations and consumer reviews on the usefulness and social presence of the website, this study employs a novel approach to generate the experimental conditions by filtering the content of Amazon.com in real time. The results show that the provision of recommendations and consumer reviews increases both the usefulness and social presence of the website.
Editorial Notes—The Growth of Interest in Services Management: Opportunities for Information Systems Scholars
Authors: Rai Arun , Sambamurthy Vallabh
Published: December 2006

Across the global economy, we are witnessing a dramatic transformation toward a services economy. At the same time, advances in information technologies provide significant opportunities for digitization of services and the development of services management thinking within the information systems community. This note aims to stimulate attention toward the promising research and teaching opportunities for information systems scholars in the domain of digitized services innovation, management, and use.
A Comment on “Is Having More Channels Really Better? A Model of Competition Among Commercial Television Broadcasters”
Authors: Chou Shan-Yu , Wu Chi-Cheng
Published: December 2006

This paper shows that the analysis of Liu et al. (2004) contains a substantive error—the asserted pure-strategy Nash equilibrium leading to their Theorems 1 and 2 is really not an equilibrium. We show that in their model, either pure-strategy Nash equilibria do not exist or, unlike their asserted main result, when a pure-strategy equilibrium exists, increasing the number of commercial television broadcasters does not result in lower-quality programs. Possible modifications of Liu et al.’s model that may help restore the desired result are discussed.
A Dynamic Lot-Sizing Model with Demand Time Windows
Authors: Lee Chung-Yee , Çetinkaya Sila , Wagelmans Albert P. M.
Published: December 2006

One of the basic assumptions of the classical dynamic lot-sizing model is that the aggregate demand of a given period must be satisfied in that period. Under this assumption, if backlogging is not allowed, then the demand of a given period cannot be delivered earlier or later than the period. If backlogging is allowed, the demand of a given period cannot be delivered earlier than the period, but it can be delivered later at the expense of a backordering cost. Like most mathematical models, the classical dynamic lot-sizing model is a simplified paraphrase of what might actually happen in real life. In most real-life applications, the customer offers a grace period—we call it a demand time window—during which a particular demand can be satisfied with no penalty. That is, in association with each demand, the customer specifies an acceptable earliest and a latest delivery time. The time interval characterized by the earliest and latest delivery dates of a demand represents the corresponding time window.

This paper studies the dynamic lot-sizing problem with demand time windows and provides polynomial time algorithms for computing its solution. If backlogging is not allowed, the complexity of the proposed algorithm is O(T2) where T is the length of the planning horizon. When backlogging is allowed, the complexity of the proposed algorithm is O(T3).
Price Dispersion and Differentiation in Online Travel: An Empirical Investigation
Authors: Clemons Eric K. , Hann Il-Horn , Hitt Lorin M.
Published: December 2006

Previous research has examined whether price dispersion exists in theoretically highly efficient Internet markets. However, much of the previous work has been focused on industries with low cost and undifferentiated products. In this paper, we examine the presence of price dispersion and product differentiation using data on the airline ticket offerings of online travel agents (OTAs). We find that different OTAs offer tickets with substantially different prices and characteristics when given the same customer request. Some of this variation appears to be due to product differentiation—different OTAs specialize by systematically offering different trade-offs between ticket price and ticket quality (minimizing the number of connections, matching requested departure and return time). However, even after accounting for differences in ticket quality, ticket prices vary by as much as 18% across OTAs. In addition, OTAs return tickets that are strictly inferior to the ticket offered by another OTA for the same request between 2.2% and 28% of the time. Overall, this suggests the presence of both price dispersion and product differentiation in the online travel market.
Repeated Games with Lack of Information on One Side: The Dual Differential Approach
Authors: Laraki Rida
Published: December 2006

We introduce the dual differential game of a repeated game with lack of information on one side as the natural continuous time version of the dual game introduced by De Meyer (1996). A traditional way to study the value of differential games is through discrete time approximations. Here, we follow the opposite approach: We identify the limit value of a repeated game in discrete time as the value of a differential game. Namely, we use the recursive structure for the finitely repeated version of the dual game to construct a differential game for which the upper values of the uniform discretization satisfy precisely the same property.

The value of the dual differential game exists and is the unique viscosity solution of a first-order derivative equation (which appears implicitely in De Meyer and Rosenberg 1999) with a limit condition. We identify the solution by translating viscosity properties in the primal.
A Note on an Axiomatization of the Core of Market Games
Authors: Sudhölter Peter , Peleg Bezalel
Published: December 2006

As shown by Peleg (1993), the core of market games is characterized by nonemptiness, individual rationality, superadditivity, the weak reduced game property, the converse reduced game property, and weak symmetry. It was not known whether weak symmetry was logically independent. With the help of a certain transitive 4-person TU game, it is shown that weak symmetry is redundant in this result. Hence, the core on market games is axiomatized by the remaining five properties, if the universe of players contains at least four members.
Improving Crew Scheduling by Incorporating Key Maintenance Routing Decisions
Authors: Cohn Amy Mainville , Barnhart Cynthia
Published: December 2006

Crew costs are the second-largest operating expense faced by the airline industry, after fuel. Thus, even a small improvement in the quality of a crew schedule can have significant financial impact. Decisions made earlier in the airline planning process, however, can reduce the number of options available to the crew scheduler. We address this limitation by delaying some of these earlier planning decisions—specifically, key maintenance routing decisions—and incorporating them within the crew scheduling problem. We present an extended crew pairing model that integrates crew scheduling and maintenance routing decisions. We prove theoretical results that allow us to improve the tractability of this model by decreasing the number of variables needed and by relaxing the integrality requirement of many of the remaining variables. We discuss how to solve the model both heuristically and to optimality, providing the user with the flexibility to trade off solution time and quality. We present a computational proof-of-concept to support the tractability and effectiveness of our approach.
How Leaders Foster Self-Managing Team Effectiveness: Design Choices Versus Hands-on Coaching
Authors: Wageman Ruth
Published: December 2006

This multi-method field study examines the relative effects of two kinds of leader behaviors—design choices and hands-on coaching—on the effectiveness of self-managing teams. Findings show that how leaders design their teams and the quality of their hands-on coaching both influence team self-management, the quality of member relationships, and member satisfaction, but only leaders' design activities affect team task performance. Moreover, design and coaching interact, so that well-designed teams are helped more by effective coaching—and undermined less by ineffective coaching—than are poorly designed teams.
Getting Off to a Good Start: The Effects of Upper Echelon Affiliations on Underwriter Prestige
Authors: Higgins Monica C. , Gulati Ranjay
Published: December 2006

The initial public offering (IPO) is one of the most critical events in the lifetime of a young firm. Prior research has shown that firms tend to have successful IPOs if they go public with the endorsement of a prestigious lead underwriter. This paper examines the antecedents to receiving endorsement by a prestigious underwriter and links this to the experience base of a firm's upper echelon. We theorize that the amount and type of upper echelon experience serve as important symbols of a young firm's legitimacy to critical outsiders. We introduce a typology of upper echelon experience that distinguishes between upper echelon upstream, horizontal, and downstream employment-based affiliations and suggest that these different types of upper echelon affiliations allay different types of endorser concerns regarding firm legitimacy, affecting the endorsement process. Further, we theorize that the relationships between upper echelon experience and investment bank prestige will be moderated by technological uncertainty. We test our assertions on a comprehensive sample of public and private biotechnology firms that were founded between 1961 and 1994 and that went public between 1979 and 1996. Analyses of the five-year career histories of the over 3,200 executives and directors that make up the upper echelons of these firms show that firms with upper echelons with affiliations with prominent downstream organizations (i.e., pharmaceutical and/or healthcare companies) and with prominent horizontal organizations (i.e., biotechnology companies) are more likely to attract the endorsement of a prestigious investment bank. We also find that the greater the range of upper echelon affiliations across the categories of upstream, horizontal, and downstream affiliations, the more prestigious the firm's lead underwriter. We also find that these latter results are moderated by technological uncertainty. The present research has implications for the study of organizational legitimacy, interorganizational endorsements, and entrepreneurship.
Spatial and Temporal Heterogeneity in Founding Patterns
Authors: Cattani Gino , Pennings Johannes M. , Wezel Filippo Carlo
Published: December 2006

A growing body of literature suggests that populations of organizations are not homogeneous, but instead comprise distinct subentities. Firms are highly dependent on their immediate institutional and competitive environments. The present paper further explores this issue by focusing on the spatial and temporal sources of industry heterogeneity. Our goal is threefold. First, we explore founding rates as a function of spatial density, arguing that density-dependent processes occur along a geographic gradient ranging from proximate, to neighboring, to more distant contexts. Second, we show how multiple, local evolutionary clocks shape such entrepreneurial activity. Third, we provide evidence on how diffusion processes are directly affected by social contagion, with new organizational forms spreading through movements of individuals. Results from data on the Dutch accounting industry corroborate these patterns of heterogeneity.
Temporarily Divide to Conquer: Centralized, Decentralized, and Reintegrated Organizational Approaches to Exploration and Adaptation
Authors: Siggelkow Nicolaj , Levinthal Daniel A.
Published: December 2006

To create a competitive advantage, firms need to find activity configurations that are not only internally consistent, but also appropriate given the firm's current environment. This challenge is particularly acute after firms have experienced an environmental change that has shifted the existing competitive landscape and created new, high-performing sets of activity choices. How should firms organize to explore and search such an altered performance landscape? While it has been noted that adaptive entities need to maintain a balance of exploration and exploitation, little is known about how different organizational structures moderate this balance. With the help of an agentbased simulation model, we study the value of three different organizational structures: a centralized organization, in which decisions are made only at the level of the firm as a whole; a decentralized organization, in which decisions are made independently in two divisions; and a temporarily decentralized firm, which starts out with a decentralized structure and later reintegrates.

We find that if interactions among a firm's activities are pervasive, neither the centralized nor the permanently decentralized organizational structure leads to high performance. In this case, temporary decentralization—an organizational structure that has not found much attention in the literature—yields the highest long-term performance. This organizational structure allows the firm both to avoid low-performing activity configurations and to eventually coordinate across its divisions. Thus, even if the decision problem a .rm faces is not fully decomposable, a temporary bifurcation can lead to a higher long-term performance outcome. Initial decentralized exploration is, however, costly in the short run, as compared to centralized exploration. As a result, a tradeoff exists between the short-term costs of decentralized exploration and the longterm benefits of reaching higher performance. As interactions across and within divisions increase, the optimal length of decentralized exploration tends to grow.

Paralleling our first result, we further show that even if a decision problem is decomposable, that is, can be perfectly modularized, it can be beneficial to create a temporary decision allocation that creates "unnecessary" interdependencies across the subsystems. This benefit arises in particular when the modules are complex by themselves. In both cases, an initial phase of exploration, enabled by an appropriate organizational structure, followed by refinement and coordination, enabled by a different structure, leads to high performance. To illustrate our general model, we focus on incumbent firms' responses to the Internet and discuss implications for the product design process.
Comparing dichotomous and trichotomous approaches to achievement goal theory: An example using motivational regulations as outcome variables
Authors: Barkoukis Vassilis. , Ntoumanis Nikos. , Nikitaras Nikitas.
Published: December 2006

Background. It is commonly assumed that there is conceptual equivalence between the task and ego achievement goals proposed by Nicholl's (1989) dichotomous achievement goal theory (Nicholls, 1989), and the mastery and performance approach goals advanced by Elliot's (1997) trichotomous hierarchical model of approach and avoidance achievement motivation.

Aims. Our study examined whether this conceptual equivalence is reflected in measurement equivalence by examining the factorial structure and predictive validity of two established questionnaires that assess achievement goals based on Nicholl's and Elliot's approaches to achievement motivation.

Sample. Greek adolescents (N=336, M age=13.45 years, SD=1.04).

Measures. The participants completed the Task and Ego Orientation in Sport Questionnaire (Duda & Nicholls, 1992), the Approach – Avoidance Achievement Goals Questionnaire (Elliot & Church, 1997) and a Physical Education (PE) version of the Self‐Regulation Questionnaire (Goudas, Biddle, & Fox, 1994).

Results. Confirmatory factor analyses of a number of competing models showed that a model with five correlated independent factors had the best fit. This finding suggests that the goals measured by the two achievement goal questionnaires are related, although independent constructs. However, hierarchical regression analyses predicting regulatory styles in PE showed quite a substantial overlap between the mastery and performance approach goals proposed by Elliot (1997), and the task and ego goals, respectively, advanced by Nicholls (1989).

Conclusions. Taken together, our results indicate that the self‐referenced and comparative1 goals of the TEOSQ and AAGQ are substantially related, to the extent that they have minimal unique predictive validity; however, they are not identical constructs.
Expression of Smad Ubiquitin Regulatory Factor 2 (Smurf2) in Rhesus Monkey Endometrium and Placenta During Early Pregnancy
Authors: Yang Qing , Lin Hai-Yan , Wang Hong-Xing , Zhang Heng , Zhang Xiaoping , Wang Hong-Mei , Zhu Cheng
Published: December 2006

Smad ubiquitin regulatory factor 2 (Smurf2) is an E3 ubiquitin ligase that is involved in the Smad-mediated TGF-β signaling. TGF-β has been shown to play an important role during normal embryo implantation, but whether Smurf2 is involved in this process has not been reported. This study was first conducted to investigate the expression of Smurf2 transcript and protein in different compartments of the rhesus monkey uteri and placenta during early pregnancy. The results showed that both the cloned partial sequence of Smurf2 gene and the corresponding amino acid residues shared 99% identity with those of human homologs. On day 12 (D12) of pregnancy, strong signals of Smurf2 mRNA were found in basalis glandular epithelium and luminal epithelium, and moderate expressions were detected in functionalis glandular epithelium. During early villi stage and villi placental stage, Smurf2 mRNAs were mainly localized in the placenta villi, trophoblastic column, trophoblastic shell, and basalis glandular epithelium. There appeared strong staining signals in the arterioles on D26 of pregnancy, but faint staining signals on D18 of pregnancy. No specific staining of Smurf2 mRNA was observed in stromal cells and myometrium. The expression pattern of Smurf2 protein was generally similar to that of its mRNA. These results provide the first evidence that Smurf2 may play specific roles in glandular secretion, trophoblastic cell invasion, and placentation through mediating the expression of the related proteins of TGF-β signaling pathway during early pregnancy.
Hypoxia-inducible Factors in the First Trimester Human Lung
Authors: Groenman Frederick , Rutter Martin , Caniggia Isabella , Tibboel Dick , Post Martin
Published: December 2006

Lung development takes place in a relatively low-oxygen environment, which is beneficial for lung organogenesis, including vascular development. Hypoxia-inducible factor (HIF)-1 plays an important role in mediating oxygen-regulated events. HIF-1 is stable and initiates gene transcription under hypoxia, whereas in normoxia, interaction with the von Hippel-Lindau (VHL) tumor suppressor protein leads to rapid degradation of the HIF-1α subunit. Interaction with VHL requires hydroxylation of HIF-1α proline residues by prolyl hydroxylases (PHDs). We investigated the expression of the various components regulating HIF-1α stability in first trimester (8-14 weeks) human lungs. Spatial expression was assessed by immunohistochemistry and temporal expression by quantitative PCR. Immunoreactivity for PHD1, PHD3, and seven in absentia homolog (SIAH) 1 was noted in the pulmonary epithelium. PHD2 was not expressed in the airway epithelium, but in the lung parenchyma. HIF-1α and vascular endothelial growth factor (VEGF) immunoreactivity were primarily detected in the branching epithelium. HIF-2α and ARNT proteins localized to the developing epithelium as well as mesenchymal, most likely vascular, structures in the parenchyma. VEGF receptor 2 (VEGFR2) was found in the subepithelium as well as in vascular structures of the mesenchyme. All components of the VEC complex (VHL, NEDD8, and Cullin2) were found in the epithelium. Quantitative PCR analysis demonstrated that VEGF, VEGFR1, HIF-1α, HIF-2α, ARNT, PHD1, PHD2, PHD3, and SIAH1 gene expression was constant during early pulmonary organogenesis. Cumulatively, the data suggest that the lung develops in a low-oxygen environment that allows for proper vascular development through HIF-regulated pathways.
Pitch and Timing in the Songs of Deaf Children With Cochlear Implants
Authors: Nakata Takayuki , Trehub Sandra E. , Mitani Chisato , Kanda Yukihiko
Published: December 2006

Congenitally deaf children (5–10 years) who use cochlear implants and hearing children of comparable age sang songs from memory. Analyses of their performances revealed timing similarities in the songs of deaf and hearing children but substantial differences in pitch patterning. Whereas hearing children accurately reproduced the relative pitch patterns of the songs they sang, deaf children did not. Deaf children’s pitch range was considerably smaller than that of hearing children, and their pitch changes were unrelated to the direction of pitch change in the target songs. For child implant users, the power and pleasure of music may arise primarily from its rhythm.
Identifying Metrical and Temporal Structure With an Autocorrelation Phase Matrix
Authors: Eck Douglas
Published: December 2006

This article introduces a new method for detecting long-timescale structure in music. We describe a way to compute autocorrelation such that the distribution of energy in phase space is preserved in a matrix. The resulting Autocorrelation Phase Matrix (APM) is useful for several tasks involving metrical structure. In this article we describe the details of calculating the APM. We then show how phase-related regularities from music are stored in the APM and present two ways to recover these regularities. The simpler approach uses variance or entropy calculated on the distribution of information in the APM. The more complex approach explicitly searches through the phase and lag space of the APM to predict meter and tempo in parallel. We compare these approaches against standard autocorrelation for the task of tempo prediction on a relatively large database of annotated digital audio files. We demonstrate that better tempo prediction is achieved by exploiting the phase-related information in the APM.We argue that the APM is an effective data structure for tempo prediction and related applications, such as real-time beat induction and music analysis.
Experiencing Groove Induced by Music: Consistency and Phenomenology
Authors: Madison Guy
Published: December 2006

There is a quality of music that makes people tap their feet, rock their head, and get up and dance. The consistency of this experience among listeners was examined, in terms of differences in ratings across 64 music examples taken from commercially available recordings. Results show that ratings of groove, operationally defined as “wanting to move some part of the body in relation to some aspect of the sound pattern,” exhibited considerable interindividual consistency. Covariance patterns among the 14 rated words indicated four prominent factors, which could be labeled regular-irregular, groove, having swing, and flowing. Considering the wide range of music examples used, these factors are interpreted as reflecting psychological dimensions independent of musical genre and style.
Microbial protein synthesis, digestion and lactation responses of cows to grass or grass-red clover silage diet supplemented with barley or oats
Authors: VANHATALO A. , GÄDDNÄS T. , HEIKKILÄ T.
Published: December 2006

The study was conducted to evaluate effects of silage type (grass-red clover vs. pure grass) and grain supplement (oats vs. barley) on rumen fermentation, post-ruminal nutrient flows, diet digestion and milk production. Four primiparous Finnish Ayrshire cows fitted with cannulae in the rumen and duodenum were used in a 4 × 4 Latin square experiment with four 28-d experimental periods and 2 × 2 factorial arrangements of treatments. Using red clover-containing (40%) silage rather than pure grass silage had minor effects on rumen fermentation or diet digestion but increased non-ammonia nitrogen (N) flow in terms of increased flows of microbial and dietary N entering to the small intestine. This was reflected as a reduced ruminal N degradability on grass-red clover diets. Furthermore, grass-red clover diets in comparison to grass silage diets increased milk lactose concentration and yields of milk, protein and lactose. Feeding oats in replacement for barley had minor effects on rumen fermentation or post-ruminal non-ammonia N flows but reduced digestibility of organic matter and neutral detergent fibre in the diet. Using oats rather than barley increased yields of milk and lactose but reduced milk protein concentration. Oats also increased proportions of C18:0 and C18:1 in milk fat and reduced those of C10:0 to C16:0. It is concluded that inclusion of red clover and replacement of barley with oats in grass silage based diets have beneficial effects in dairy cow production.;
Effect of lactic acid bacteria inoculants, formic acid, potassium sorbate and sodium benzoate on fermentation quality and aerobic stability of wilted grass silage
Authors: SAARISALO E. , JALAVA T. , SKYTTÄ E.
Published: December 2006

The efficiency of a novel strain of lactic acid bacteria inoculant (Lactobacillus plantarum VTT E-78076, E76) on the fermentation quality of wilted silage was studied. Furthermore, the possibility to improve aerobic stability of silages by combining an inoculant and chemical preservatives was investigated. Two experiments were conducted with wilted timothy-meadow fescue herbage (dry matter 429 and 344 g kg-1) using six treatments. In experiment I, E76 (106 cfu g-1 fresh matter (FM)) was applied alone and in combination with sodium benzoate (0.3 g kg-1 grass FM) or low rate of formic acid (0.4 l t-1 FM). In experiment II, E76 and a commercial inoculant were applied alone and in combination with sodium benzoate. Untreated silage and formic acid (4 l t-1 FM) treated silage served as negative and positive controls in both experiments. The effect of sodium benzoate and potassium sorbate in experiment I, on aerobic stability was tested by treating silages prior to aerobic stability measurements. The novel lactic acid bacteria inoculant was equally effective in improving fermentation quality as the commercial inoculant. However, the aerobic stability of both inoculated silages was poorer than that of formic acid treated or the untreated one in one of the experiments. The results suggested that antimicrobial properties of E76 were not effective enough to improve aerobic instability. One option to overcome this problem is to use chemical additives in combination with the inoculants.;