bluuebunny/crossref_metadata_2025 huggingface dataset:
(—)-Epigallocatechin gallate (EGCG) prevents isoprenaline-induced cardiac toxicity by stabilizing cardiac marker enzymes and membrane-bound ATPases
Authors: Devika Periyathambi Thangappan , Prince Ponnian Staneley Mainzen
Published: December 2007

Intake of tea flavonoids has been reported to reduce the incidence of cardiovascular disease. The present study was undertaken to investigate the preventive effect of (—)epigallocatechin gallate (EGCG) on heart weight, cardiac marker enzymes, membrane-bound ATPases and electrolytes in isoprenaline (ISO)-induced myocardial infarcted (MI) Wistar rats. Rats subcutaneously administered ISO 100 mgkg−1 at intervals of 24 h for 2 days resulted in significant increases in heart weight and the activities of cardiac marker enzymes such as creatine kinase, creatine kinase-MB, lactate dehydrogenase (LDH), aspartate transaminase and alanine transaminase in serum, and significant decreases in the activities of these enzymes in the myocardium. ISO injection also increased levels of LDH isoenzymes (LDH 1 and LDH 2). The activity of Na+/K+ ATPase was decreased significantly and the activities of Ca2+ and Mg2+ ATPases were increased significantly in ISO-induced MI rats. Furthermore, the levels of potassium were lowered and the levels of sodium and calcium were increased in ISO-induced MI rats. Prior treatment with EGCG (10, 20 and 30 mgkg−1) daily for a period of 21 days reduced the effects of ISO on heart weight, activities of cardiac marker enzymes and membrane bound-ATPases and levels of LDH 1 and LDH 2 and electrolytes. Thus, EGCG exhibits beneficial effects on these enzymes and electrolytes. The observed effects may be due to the antioxidant and membrane-stabilizing effects of EGCG in ISO-induced MI rats.
Development of Chiral Bicyclic Triazolium Salt Organic Catalysts: The Importance of the N-Aryl Substituent
Authors: Rovis Tomislav
Published: December 2007

The development of a family of chiral bicyclic triazolium salts is described. Treatment of these salts with base provides a nucleophilic carbene which may be used as an organic catalyst for asymmetric acyl anion chemistry including the benzoin and Stetter reactions, and some recently developed redox chemistry. Throughout the development of these reactions, the nature of the N-aryl substituent on the triazole ring has proven to have a profound effect on both reactivity and selectivity. These observations have also paralleled those made by others using our family of catalysts.
Fabrication of Carbon Nanostructures by Pulsed Electric Discharge between Metal Electrodes Using Fluorine-containing Organic Liquid
Authors: Hosoi Katsuhiko , Kuroda Shin-ichi , Kubota Hitoshi
Published: December 2007

The carbon nanotube and carbon nanoparticle that contain fluorine on the surface were prepared by the pulsed electric discharge in fluorine-containing organic liquid. The production rate of carbon nanostructures by this method was found to be about 50 times faster than that by the “arc in liquid” method previously reported.
Life-Cycle Prices and Production
Authors: Aguiar Mark , Hurst Erik
Published: December 2007

We use scanner data and time diaries to document how households substitute time for money through shopping and home production. We document substantial heterogeneity in prices paid for identical goods for the same area and time, with older households shopping the most and paying the lowest prices. Doubling shopping frequency lowers a good's price by 7 to 10 percent. We estimate the shopper's price of time and use this series to estimate an elasticity of substitution between time and goods in home production of roughly 1.8. The observed lifecycle time allocation implies a consumption series that differs markedly from expenditures. (JEL D12, D91)
Theft, Gift-Giving, and Trustworthiness: Honesty Is Its Own Reward in Rural Paraguay
Authors: Schechter Laura
Published: December 2007

In developing countries lacking legal enforcement, villagers may use implicit contracts to minimize crime. I construct a dynamic limited-commitment model, in which a thief cannot commit to forego stealing, but is induced to steal less by the promise of future gifts. Combining survey data on production, theft, gifts, and trust with experiments measuring trustworthiness, I provide supporting evidence. Farmers living near more relatives or with plots that are difficult to steal from give fewer gifts and trust more, and those living near more relatives also experience less theft. Giving increases when trust is lower and the threat of theft is greater. (JEL D86, K42, O17, Z13)
Child Protection and Child Outcomes: Measuring the Effects of Foster Care
Authors: Doyle Joseph J
Published: December 2007

Little is known about the effects of placing children who are abused or neglected into foster care. This paper uses the placement tendency of child protection investigators as an instrumental variable to identify causal effects of foster care on long-term outcomes—including juvenile delinquency, teen motherhood, and employment—among children in Illinois where a rotational assignment process effectively randomizes families to investigators. Large marginal treatment effect estimates suggest caution in the interpretation, but the results suggest that children on the margin of placement tend to have better outcomes when they remain at home, especially older children. (JEL H75, I38, J13)
Trade Liberalization, Intermediate Inputs, and Productivity: Evidence from Indonesia
Authors: Amiti Mary , Konings Jozef
Published: December 2007

This paper estimates the productivity gains from reducing tariffs on final goods and from reducing tariffs on intermediate inputs. Lower output tariffs can increase productivity by inducing tougher import competition, whereas cheaper imported inputs can raise productivity via learning, variety, and quality effects. We use Indonesian manufacturing census data from 1991 to 2001, which include plant-level information on imported inputs. The results show that a 10 percentage point fall in input tariffs leads to a productivity gain of 12 percent for firms that import their inputs, at least twice as high as any gains from reducing output tariffs. (JEL F12, F13, L16, O14, O19, O24)
Demographics and Industry Returns
Authors: DellaVigna Stefano , Pollet Joshua M
Published: December 2007

How do investors respond to predictable shifts in profitability? We consider how demographic shifts affect profits and returns across industries. Cohort size fluctuations produce forecastable demand changes for age-sensitive sectors, such as toys, bicycles, beer, life insurance, and nursing homes. These demand changes are predictable once a specific cohort is born. We use lagged consumption and demographic data to forecast future consumption demand growth induced by changes in age structure. We find that demand forecasts predict profitability by industry. Moreover, forecast demand changes five to ten years in the future predict annual industry stock returns. One additional percentage point of annualized demand growth due to demographics predicts a 5 to 10 percentage point increase in annual abnormal industry stock returns. However, forecasted demand changes over shorter horizons do not predict stock returns. A trading strategy exploiting demographic information earns an annualized risk-adjusted return of approximately 6 percent. We present a model of inattention to information about the distant future that is consistent with the findings. We also discuss alternative explanations, including omitted risk-based factors. (JEL E21, G12, G32, J11, L11, L25)
Group Reputations, Stereotypes, and Cooperation in a Repeated Labor Market
Authors: Healy Paul J
Published: December 2007

Reputation effects and other-regarding preferences have both been used to predict cooperative outcomes in markets with inefficient equilibria. Existing reputationbuilding models require either infinite time horizons or publicly observed identities, but cooperative outcomes have been observed in several moral hazard experiments with finite horizons and anonymous interactions. This paper introduces a full reputation equilibrium (FRE) with stereotyping (perceived type correlation) in which cooperation is predicted in early periods of a finitely repeated market with anonymous interactions. New experiments generate results in line with the FRE prediction, including final-period reversions to stage-game equilibrium and noncooperative play under unfavorable payoff parameters. (JEL C72, C73, C78, J41)
Does Price Matter in Charitable Giving? Evidence from a Large-Scale Natural Field Experiment
Authors: Karlan Dean , List John A
Published: December 2007

We conducted a natural field experiment to further our understanding of the economics of charity. Using direct mail solicitations to over 50,000 prior donors of a nonprofit organization, we tested the effectiveness of a matching grant on charitable giving. We find that the match offer increases both the revenue per solicitation and the response rate. Larger match ratios (i.e., $3:$1 and $2:$1) relative to a smaller match ratio ($1:$1) had no additional impact, however. The results provide avenues for future empirical and theoretical work on charitable giving, cost-benefit analysis, and the private provision of public goods. (JEL D64, L31)
Impossibility of Collusion under Imperfect Monitoring with Flexible Production
Authors: Sannikov Yuliy , Skrzypacz Andrzej
Published: December 2007

We show that it is impossible to achieve collusion in a duopoly when (a) goods are homogenous and firms compete in quantities; (b) new, noisy information arrives continuously, without sudden events; and (c) firms are able to respond to new information quickly. The result holds even if we allow for asymmetric equilibria or monetary transfers. The intuition is that the flexibility to respond quickly to new information unravels any collusive scheme. Our result applies to both a simple stationary model and a more complicated one, with prices following a mean-reverting Markov process, as well as to models of dynamic cooperation in many other settings. (JEL D43, L12, L13)
Consensus Building: How to Persuade a Group
Authors: Caillaud Bernard , Tirole Jean
Published: December 2007

The paper explores strategies that the sponsor of a proposal may employ to convince a qualified majority of members in a group to approve the proposal. Adopting a mechanism design approach to communication, it emphasizes the need to distill information selectively to key group members and to engineer persuasion cascades in which members who are brought on board sway the opinion of others. The paper shows that higher congruence among group members benefits the sponsor. The extent of congruence between the group and the sponsor, and the size and the governance of the group, are also shown to condition the sponsor's ability to get his project approved. (JEL D71, D72, D83)
Another Look at Airport Congestion Pricing
Authors: Morrison Steven A , Winston Clifford
Published: December 2007

We study alternate approaches to implement congestion pricing at US airports. Conventional formulations toll all aircraft without determining whether a plane operated by a given airline delays other planes that it operates or planes operated by other airlines. Recent work points out optimal pricing calls for carriers to be charged only for the delay they impose on other airlines. We find a small difference between the net benefits generated by the two congestion-pricing policies because the bulk of airport delays are not internalized and because the efficiency loss from pricing internalized congestion is small. (JEL L11, L93, R41)
Overconfidence, Insurance, and Paternalism
Authors: Sandroni Alvaro , Squintani Francesco
Published: December 2007

It is well known that when agents are fully rational, compulsory public insurance may make all agents better off in the Rothschild and Stiglitz (1976) model of insurance markets. We find that when sufficiently many agents underestimate their personal risks, compulsory insurance makes low-risk agents worse off. Hence, behavioral biases may weaken some of the well-established rationales for government intervention based on asymmetric information. (JEL D82, G22)
Improving Infill Development Decision Making with Interval Estimation
Authors: Jobe J. Marcus , Jobe Hutch
Published: December 2007

Following partial completion of infill development in a given field, it becomes necessary to determine whether continued drilling should be pursued in the same field. The usual approaches for deciding whether to continue drilling (Swanson's mean or estimates based on lognormal methods) fail to account for variation and uncertainty. To better inform this decision, we propose implementing statistical confidence intervals (with an accompanying certainty level) for relevant features of interest. Closed form intervals and maximum likelihood based intervals for the average ultimate recovery for all wells in a field, the percent of wells in a field having ultimate recovery values above a certain benchmark value and other important features of interest are considered. Confidence intervals appropriate for both the lognormal and Weibull distribution are given. The proposed methods are illustrated with real data from 64 wells in the Devonian Richfield Dolomite of the Michigan basin (given in the appendix, Table 2). Table 1 summarizes the different confidence intervals.
Selfstress States Identification and Localization in Modular Tensegrity Grids
Authors: Sánchez R. , Maurin B. , Kazi-Aoual M.N. , Motro R.
Published: December 2007

The design of a modular tensegrity grid requires the determination of its selfstress states, before choosing an appropriate combination defining the system's initial stresses. However, the computation of the vectorial basis associated with selfstress states generally produces results that are difficult to exploit. We therefore propose two different strategies to identify and localize selfstress states in a modular tensegrity grid more pertinently. The first is based on a heuristic approach that exploits the system's structural composition of modularity and regularity. The second is numerical and aims at redefining the vectors of the basis in a more convenient and useful way. Two methods based on transformations of the vectorial basis of selfstress states have been developed for a minimal number of involved components. Finally, we suggest a selfstress state classification based on the number of components and their localization as well as on their mechanical behavior.
Selfstressed Systems Comprising Elements with Unilateral Rigidity: Selfstress States, Mechanisms and Tension Setting
Authors: Quirant Jérôme
Published: December 2007

Selfstressed reticulated systems have given rise to many studies in the past. However, the theoretical studies undertaken were based on the assumption that their components had bilateral rigidities when, in fact for systems with elements as cables (tensegrity or cable-strut systems) this hypothesis is not valid any more.

We propose here to extend the methods of research of the selfstress states or the mechanisms for such systems. Then we can at the same time:

choose the relevant selfstress states verify that cables do not induce unilateral mechanisms optimize the number of active elements for the tension setting of the system.
Simulation Analysis of Vibration Characteristics of Wrinkled Membrane Space Structure
Authors: Changguo Wang , Yunliang Li , Xingwen Du , Xiaodong He , Guozhi Song
Published: December 2007

Flexible membrane space structures have received the widest attention due to their small packaging volume and low launching cost, but wrinkles as the common deformation state, are the main failure mode of such structures. They also affect the vibration characteristics which are the main factor of the structural analysis and design. So a better understanding of the vibration characteristics of the wrinkled membrane structure is essential and desirable. In this paper, a modal analysis, incorporating the wrinkling analysis, is presented to model the vibration characteristics of the wrinkled square membrane structure subjected to the asymmetric tension. The effects of the wrinkles on the vibration characteristics of the wrinkled membrane structures are considered in detail. Some important conclusions are also summarized in detail at last. The results of this paper are very important when used in the structural design and optimization of the membrane space structure.
FE Modeling of Tension Pin-end Connections
Authors: Xudong Xu , Ono Tetsuro , Fulin Guan
Published: December 2007

Pin-end connections have been widely used in tension structures. Accurate design methods are required to ensure these connections are safe and economic. The modeling of a given connection type is normally based on the determination of the connection behavior using experimental or numerical methods. This paper presents some finite-element (FE) modeling principles to analyze pin-end connections. The MSCMarc finite-element package is used to simulate the experimental behavior observed in tests conducted at the Nagoya Institute of Technology, Japan. The parameters varied in both the experiments and MSCMarc simulations are the inner radius of pin-block and gusset-block, the radius and the position of pin. The results obtained from the FE analyses are evaluated and the numerically predicted ultimate strengths are also compared with experiment data. It is shown that the proposed modeling principles are effective and efficient.
Aspects of the Dynamic Response of a Small Wind Turbine Blade in Highly Turbulent Flow: Part 2 Predicted Blade Response
Authors: Wilson S.V.R. , Clausen P.D.
Published: December 2007

The work described in this paper compares the measured blade root flapwise bending moment on a 400W 3-bladed wind turbine to analytical predictions and calculations from the “simple load model” of the International Electrotechnical Commission safety standard for small wind turbines. The predictions use the method of Eggleston and Stoddard (1987) and were found to over predict the measured azimuthal averaged flapwise root bending moment. During an extreme yaw event, the instantaneous blade root flapwise bending moment was found to be dominated by the gyroscopic moment from the blades. The calculated fatigue loads from the safety standard were some 25% lower than the measured values, with the calculated yaw moment under-predicting the measured flapwise bending moment for a range of turbine yaw rates with the error increasing with increasing blade rotational speed. A Combination of the calculated root bending moment from yaw and yaw error was found to over-estimate the root flapwise bending moment especially at high rotational speeds.
Quantification of Condition Monitoring Benefit for Offshore Wind Turbines
Authors: McMillan David , Ault Graham W.
Published: December 2007

Condition monitoring (CM) systems are increasingly installed in wind turbines with the goal of providing component-specific information to wind farm operators, theoretically increasing equipment availability via maintenance and operating actions based on this information. In the offshore case, economic benefits of CM systems are often assumed to be substantial, as compared with experience of onshore systems. Quantifying this economic benefit is non-trivial, especially considering the general lack of utility experience with large offshore wind farms. A quantitative measure of these benefits is therefore of value to utilities and operations and maintenance (O & M) groups involved in planning and operating future offshore wind farms. The probabilistic models presented in this paper employ a variety of methods including discrete-time Markov Chains, Monte Carlo methods and time series modelling. The flexibility and insight provided by this framework captures the necessary operational nuances of this complex problem, thus enabling evaluation of wind turbine CM offshore. The paper concludes with a study of baseline CM benefit, sensitivity to O & M costs and finally effectiveness of the CM system itself.
A New Decision Making Approach to Wind Energy Site Assessment
Authors: Lackner Matthew A. , Manwell James F.
Published: December 2007

This paper describes an objective decision making approach for wind energy site assessment. It is often assumed that a full year of measured data is necessary to make a decision of whether or not to build a wind farm at a site, due to larger uncertainty in estimating the long-term wind resource associated with measurement periods less than one year. The approach in this paper considers if it is possible to make a decision well before a year of measurement is complete, despite the larger uncertainty. The basic premise is that at any point in the site assessment process, one can choose between stopping measurement and building a wind farm, stopping measurement and not building a wind farm, and continuing measurement. Portable ground-based device, such as SODAR and LIDAR, allow measurements to be stopped at a site and recommenced at another site. A decision making framework is developed, in which the three options are evaluated and compared after a period of data acquisition. This approach begins by utilizing Measure-Correlate-Predict to estimate the long-term annual mean wind speed. Next, cash flow analysis, with realistic constraints on the debt service coverage ratio, is used to analyze the economics of building a project. A recursive dynamic program is used to evaluate the option to continue measurement. Finally, the net present value of the cash flows is used to evaluate the three possible choices, and the “best” of the three choices is determined. When the optimal choice is to continue measurement, another measurement period is considered. This approach is applied to fifteen pairs of data sets, and the results indicate that it is an extremely effective method for reducing the average measurement time at a site. Furthermore, the accuracy of the decisions made using this method is equivalent to the accuracy when an entire year of measured on-site data is used. Lastly, this approach achieves significant savings on average in the site assessment process, for all 15 sites, due to both reduced measurement time and more rapid development.
Design and Implementation of an Active Absorber
Authors: Yuan Jing
Published: December 2007

Active control may be introduced to resonators to improve noise control performance. Many active controllers depend on accurate transfer functions from speakers to error sensors to generate destructive interference. These transfer functions are sensitive to acoustical parameters in noise fields where error sensors are installed. An alternative strategy is to modify internal resonator impedance instead of destructive interference in noise fields. This approach focuses on the internal dynamics of a resonator and uses an equivalent primary source to model the external noise field. A controller is designed on the basis of the internal dynamics and is hence independent of external acoustical parameters. The controller improves absorption by minimising noise reflection inside the resonator. Such an active absorber is implemented and tested in experiments to achieve near perfect absorption performance in a wide frequency range. The closed-loop system is stable and reliable with respect to significant variations of acoustical parameters in the external field.
A Design Methodology for Multiple Tonal Beam-Type Vibration Absorber
Authors: Wang P. W. , Cheng C. C.
Published: December 2007

The purpose of this paper is to introduce a systematic method of designing a beam-type vibration absorber that attenuates vibration at multiple frequencies. This vibration absorber is a non-uniform beam with natural frequencies intentionally designed to coincide with or close to the frequencies of excitation, e.g. the rotating speed of a rotary machine and its harmonic orders. Therefore it can reduce the vibration response due to rotor eccentric, rotor shaft bending, mechanical looseness, etc. The thickness profile of the non-uniform beam can be determined systematically using the impedance technique proposed in this paper. A design is given to demonstrate the methodology and the result is experimentally validated.
On Optimized Extrapolation Method for Elliptic Problems with Large Coefficient Variation
Authors: Garbey M. , Shyy W.
Published: December 2007

A posteriori error estimators are fundamental tools for providing confidence in the numerical computation of PDEs. In this paper we present a new technique that produces global a posteriori error estimates based on an optimized extrapolation method. The choice of the objective function as well as the representation of the unknown weight function in the extrapolation formula is discussed. This paper focuses on applications governed by the elliptic problem div(ρΔ u) = f, with Dirichlet boundary conditions. Special attention is given to problems where the positive coefficient ρ exhibits large variations throughout the domain or f contains some singular source terms. These features are commonly encountered in physical problems including heat transfer with heterogeneous material properties and pressure solver in multiphase flows with large ratio of density between fluids.
Solution of Linear Systems by GMRES Method on Global Computing Platform
Authors: He Haiwu , Bergere Guy , Wang Zhijian , Petiton Serge
Published: December 2007

By making use of a very large amount of unexploited computing resources, grid computing achieves high throughput computing. We present a classical parallel method GMRES (m) to solve large sparse linear systems utilizing a lightweight GRID system XtremWeb. XtremWeb is a global computing platform which is dedicated to multi-parameters generic applications. We have implemented this important algorithm GMRES (m) which is one of the key methods to resolve large, non-symmetric, linear problems on this system. We discuss as well the performances of this implementation deployed on two XtremWeb networks: a local network with 128 non-dedicated PCs in Polytech-Lille of University of Sciences and Technologies of Lille, France, a remote network with 3 clusters of SCGN Grid including 91 CPUs totally in the High Performance Computing Center of University of Tsukuba in Japan. We also performed the tests on the platform of supercomputer IBM SP4 of CINES in Montpellier, France. We compare the performances on the two different computing systems. The advantages and drawbacks of our implementations on this GRID computing system XtremWeb will be well explained.
Approximate NGPC Algorithm for Real Time System Applications
Authors: Rao D. N. , Murthy M. Radha Krishna , Praveen J.
Published: December 2007

The central theme of this paper is to delineate computationally simple and efficient new methods in order to improve the usefulness of Neural Generalized Predictive Control (NGPC) algorithm further through Smaller Prediction horizon with modified performance index and recursive formulation is presented. The combined effect of these schemes are demonstrated and examined. The simulation results show that it is a viable approach with good performance for real time system applications.
Numerical Simulation of the Nonlinear Fractional Dynamical Systems with Fractional Damping for the Extensible and Inextensible Pendulum
Authors: Yin C. , Liu F. , Anh V.
Published: December 2007

In this paper we consider a class of nonlinear dynamical systems with fractional damping. The problem is transformed into a system of fractional-order differential equations. A computationally effective fractional predictor-corrector method is used to simulate and examine the effects and solution behavior of the nonlinear dynamical systems with fractional damping for extensible and inextensible pendulum. The corresponding error analysis is derived. Finally, some numerical examples are given. This method and technique can be applied to solve other fractional-order ordinary differential equations.
CFD Analysis of One-Dimensional Infiltration in Vadose Zone
Authors: Frost Nageena K. , Patel Mayur K. , Lai Choi-Hong
Published: December 2007

This study presents a CFD analysis constructed around PHYSICA, an open framework for multi-physics computational continuum mechanics modelling, to investigate the water movement in unsaturated porous media. The modelling environment is based on a cell-centred finite-volume discretisation technique. A number of test cases are performed in order to validate the correct implementation of Richard's equation for compressible and incompressible fluids. The pressure head form of the equation is used together with the constitutive relationships between pressure, volumetric water content and hydraulic conductivity described by Haverkamp and Van Genuchten models. The flow problems presented are associated with infiltration into initially dry soils with homogeneous or layered geologic settings. Comparison of results with the problems selected from literature shows a good agreement and validates the approach and the implementation.
A Coordinates Rotating Algorithm for Computing Fourier Series with Basic Operations
Authors: Gu Feng
Published: December 2007

In this paper, a coordinates rotating algorithm for computing Fourier series with only basic operations adding, subtracting, and shifting was put forward. Convergence of the algorithm was proved and error estimation of the algorithm was discussed.
Small Worlds and Regional Innovation
Authors: Fleming Lee , King Charles , Juda Adam I.
Published: December 2007

Small-world networks have attracted much theoretical attention and are widely thought to enhance creativity. Yet empirical studies of their evolution and evidence of their benefits remain scarce. We develop and exploit a novel database on patent coauthorship to investigate the effects of collaboration networks on innovation. Our analysis reveals the existence of regional small-world structures and the emergence and disappearance of giant components in patent collaboration networks. Using statistical models, we test and fail to find evidence that small-world structure (cohesive clusters connected by occasional nonlocal ties) enhances innovative productivity within geographic regions. We do find that both shorter path lengths and larger connected components correlate with increased innovation. We discuss the implications of our findings for future social network research and theory as well as regional innovation policies.
Corporate Governance Reform as Institutional Innovation: The Case of Japan
Authors: Yoshikawa Toru , Tsui-Auch Lai Si , McGuire Jean
Published: December 2007

To address the convergence-divergence debate in corporate governance, we conduct a multiple-case, multiple-level study to analyze the diffusion of governance innovation in Japan. We argue that Japanese systems of corporate governance neither fully converge to, nor completely diverge from, the Anglo-American model. Rather, Sony—the pioneer of corporate governance reforms—and its followers selectively adopted features from this model, decoupled them from the original context, and tailored them to fit to their own situations to generate governance innovation. However, we find that the spread of innovation across firms and institutional levels is far from linear and straightforward, and that other well-regarded firms raised strong opposition to the institutionalization of corporate governance reforms. Eventually, the Ministry of Justice revised the Commercial Code to legitimize different systems, which led to the emergence of diverse corporate governance practices.

Based on the results of our study, we construct an analytical framework to examine innovation diffusion in light of conflicting institutional pressures for change and continuity. Our analysis adds complexity to the convergence-divergence debate by identifying the creation of hybrid corporate governance systems and the nonlinear evolution of such systems as a result of interactions across multiple levels. We show the various degrees of decoupling from the Anglo-American model and identify the antecedents. We then extend the conventional focus of innovation research on diffusion across firms to examine diffusion across institutional levels. We also contribute to institutional theory by offering insights into organizational field formation and the conceptualization of the state in shaping institutional change and continuity.
Building Dynamic Capabilities: Innovation Driven by Individual-, Firm-, and Network-Level Effects
Authors: Rothaermel Frank T. , Hess Andrew M.
Published: December 2007

Following the dynamic capabilities perspective, we suggest that antecedents to innovation can be found at the individual, firm, and network levels. Thus, we challenge two assumptions common in prior research: (1) that significant variance exists at the focal level of analysis, whereas other levels of analysis are assumed to be homogeneous, and (2) that the focal level of analysis is independent from other levels of analysis. Accordingly, we advance a set of hypotheses to simultaneously assess the direct effects of antecedents at the individual, firm, and network levels on innovation output. We then investigate whether a firm's antecedents to innovation lie across different levels. To accomplish this, we propose two competing interaction hypotheses. We juxtapose the hypothesis that the individual-, firm-, and network-level antecedents to innovation are substitutes versus the proposition that these innovation mechanisms are complements. We test our multilevel theoretical model using an unusually comprehensive and detailed panel data set that documents the innovation attempts of global pharmaceutical companies within biotechnology over a 22-year time period (1980–2001). We find evidence that the antecedents to innovation lie across different levels of analysis and can have compensating or reinforcing effects on firm-level innovative output.
Geography, Networks, and Knowledge Flow
Authors: Bell Geoffrey G. , Zaheer Akbar
Published: December 2007

Knowledge—which is closely linked to firm innovativeness—is accessed across organizational boundaries and geographic space via networks operating at different levels of analysis. However, we know tantalizingly little about the comparative influence of geography on knowledge flow across organizational boundaries over different types of ties, despite warnings that research needs to account for the geographic context of ties to fully understand causal relationships. Using a combination of primary and secondary data on 77 Canadian mutual fund companies, we find that institutional-level ties are valuable in knowledge transmission only when such ties are geographically proximate. Organization-level ties fail to act as transmitters of knowledge, regardless of geographic location. Interestingly, we find that geographically distant individual-level friendship ties are superior conduits for knowledge flow, which suggests they span “geographic holes.”
Exploring the Foundations of Cumulative Innovation: Implications for Organization Science
Authors: Murray Fiona , O'Mahony Siobhán
Published: December 2007

Organizational theorists have built a deep understanding of the conditions affecting knowledge sharing. However, for innovation to occur, knowledge must not just be shared, but also reused, recombined, and accumulated. Such accumulation is not inherent to the innovation process but can be either supported or limited by the context in which it occurs. We propose a framework arguing that three conditions shape this context: disclosure, access, and rewards. We show how these conditions operate at the institutional, field, community, and organizational levels. Our framework highlights how when innovators encounter barriers to the accumulation of knowledge, their solutions are often organizational ones rather than legal ones. This suggests an expanding terrain for organizational scholars interested in debates often dominated by law and economics.
Innovation At and Across Multiple Levels of Analysis
Authors: Gupta Anil K. , Tesluk Paul E. , Taylor M. Susan
Published: December 2007

In this introductory article for the Special Issue on Innovation At and Across Multiple Levels of Analysis, we review major streams of extant research on innovation to establish a clear role for multilevel theory and research within this domain. We then examine and illustrate two fundamental and complementary approaches for investigating multilevel linkages—bottom-up emergent processes and top-down processes. In a brief commentary on each paper in the special issue, we overview the conceptual questions addressed by the research, identify the particular model of multilevel effects that serves as its foundation, and suggest how the use of multilevel models provides insights that help us better understand how innovation phenomena at one level of analysis are linked to those at another, thus providing a richer and more complete perspective on innovation. We conclude by identifying major methodological and applied contributions of the special issue and suggesting future research directions for the study of innovation at and across multiple levels of analysis.
Noninvasive Optical, Electrical, and Acoustic Methods of Total Hemoglobin Determination
Authors: McMurdy John W , Jay Gregory D , Suner Selim , Crawford Gregory
Published: December 2007

Background: Anemia is an underdiagnosed, significant public health concern afflicting >2 billion people worldwide. The detrimental effects of tissue oxygen deficiency on the cardiovascular system and concurrent appearance of anemia with numerous high-risk disorders highlight the importance of clinical screening. Currently there is no universally accepted, clinically applicable, noninvasive hemoglobin/hematocrit screening tool. The need for such a device has prompted an investigation into a breadth of techniques.

Methods: A synopsis of the literature and current directions of research in noninvasive total hemoglobin measurement was collected. Contributions highlighted in this review are limited to those studies conducted with a clinical aspect, and most include in vivo patient studies.

Results: The review of potential techniques presented here includes optoacoustic spectroscopy, spectrophotometric imaging, diffuse reflectance spectroscopy, transcutaneous illumination, electrical admittance plethysmography, and photoplethysmography. The technological performance, relative benefits of each approach, potential instrumentation design considerations, and future directions are discussed in each subcategory.

Conclusions: Many techniques reviewed here have shown excellent accuracy, sensitivity, and specificity in measuring hemoglobin/hematocrit, thus in the near future a new clinically viable tool for noninvasive hemoglobin/hematocrit monitoring will likely be widely used for patient care. Limiting factors in clinical adoption will likely involve technology integration into the current standard of care in each field routinely dealing with anemia.
Evaluation of Endometrial Urocortin Secretion for Prediction of Pregnancy after Intrauterine Insemination
Authors: Florio Pasquale , Bruni Luca , De Falco Carmen , Filardi Gilda , Torricelli Michela , Reis Fernando M , Galleri Letizia , Voltolini Chiara , Bocchi Caterina , De Leo Vincenzo , Petraglia Felice
Published: December 2007

Background: Urocortin is a neuropeptide produced by the human endometrium and has biological effects putatively important for promoting blastocyst implantation. We measured urocortin concentrations in samples of endometrial wash fluid collected from women with unexplained infertility who underwent intrauterine insemination (IUI).

Methods: Patients 28–42 years of age (n = 71) were consecutively enrolled after a complete clinical evaluation. Endometrial wash fluid was retrieved before IUI, at the time of ultrasound evaluation of endometrial thickness. Urocortin concentrations were assayed with a specific ELISA.

Results: After IUI, 28 patients (39%) became pregnant. Urocortin concentrations were significantly higher in women who became pregnant than in those who did not (0.38 μg/L vs 0.13 μg/L, P <0.0001). At a cutoff of 0.321 μg/L, urocortin results were positive in 61% [95% confidence interval (CI), 41%–78%] of women who had successful implantation and negative in 98% (95% CI, 88%–99.6%) of those who did not. The pregnancy rate for women with urocortin concentrations >0.32 μg/L was 94%, which differed significantly (P <0.05) from the overall pregnancy rate of 39% in the study population.

Conclusions: Urocortin is measurable in endometrial wash fluid, and its concentrations before IUI are higher in women who subsequently achieve pregnancy. These data suggest that the probability of having a successful pregnancy-producing IUI may be better estimated by measuring urocortin in endometrial wash fluid.
Bloodspot Assay Using HPLC–Tandem Mass Spectrometry for Detection of Barth Syndrome
Authors: Kulik Willem , van Lenthe Henk , Stet Femke S , Houtkooper Riekelt H , Kemp Helena , Stone Janet E , Steward Colin G , Wanders Ronald J , Vaz Frédéric M
Published: December 2007

Background: Barth syndrome (BTHS) is a serious X-linked, metabolic, multisystem disorder characterized by cardiomyopathy, neutropenia, myopathy, and growth delay. Because early diagnosis and appropriate treatment are of key importance for the survival of affected boys, we developed a biochemical BTHS screening method based on analysis of the monolysocardiolipin:cardiolipin ratio in bloodspots.

Methods: We performed chloroform/methanol extraction on quarter-inch punches of dried bloodspots on Guthrie cards from BTHS patients and controls. Extracts were dried (60 °C, N2) and reconstituted in CHCl3/methanol/H2O [50:45:5 vol/vol/vol, 0.1% NH3 (25%)]. HPLC–tandem mass spectrometry analysis was performed with a normal-phase HPLC column and multiple reaction monitoring transitions for monolysocardiolipin (MLCL) and cardiolipin (CL) with a total run time of 10 min. The ratio of MLCL and CL was used as screening parameter.

Results: All BTHS patients (n = 31) had monolysocardiolipin:cardiolipin ratios >0.40 and all controls (n = 215) had monolysocardiolipin:cardiolipin ratios <0.23. Using a cutoff point of 0.30, a blind test of 206 samples (199 controls, 7 BTHS) had sensitivity and specificity of 100%. Bloodspots could be stored at 4 °C or room temperature for >1 year without affecting the test outcome. Three neonatal Guthrie cards of BTHS patients taken 3.6 to 5.8 years previously were correctly identified as positive for BTHS.

Conclusions: HPLC–tandem mass spectrometry analysis of dried bloodspots is an unambiguous screening test for BTHS with potential for rapid screening of neonates suspected of having BTHS, making remote and retrospective diagnosis accessible for a disease that is almost certainly underdiagnosed.
Effect of Homocysteine Concentration in Early Pregnancy on Gestational Hypertensive Disorders and Other Pregnancy Outcomes
Authors: Dodds Linda , Fell Deshayne B , Dooley Kent C , Armson B Anthony , Allen Alexander C , Nassar Bassam A , Perkins Sherry , Joseph K S
Published: December 2007

Background: Increased total homocysteine (tHcy) may be associated with placental-mediated adverse pregnancy outcomes, but few prospective studies have measured tHcy before pregnancy outcome. This study was undertaken to determine whether increased tHcy measured in early pregnancy is associated with pregnancy loss, gestational hypertension (GH), preeclampsia, or small for gestational age (SGA) infants.

Methods: We conducted a prospective cohort study between 2002 and 2005. We measured tHcy and serum folate in blood samples from pregnant women (<20 weeks’ gestation) and collected detailed pregnancy information through a questionnaire and medical record review.

Results: Of the 2119 women included in the study, 103 had a pregnancy loss, 115 had gestational hypertension, 65 had preeclampsia, and 129 had an SGA infant. Subjects with increased tHcy concentrations were at increased risk of pregnancy loss [relative risk (RR) 2.1, 95% CI 1.2–3.6] or preeclampsia (RR 2.7, 95% CI 1.4–5.0) than subjects with lower tHcy concentrations, but increased tHcy concentration was not associated with increased risk of developing GH or having an SGA infant.

Conclusion: The finding of high tHcy in early pregnancy as a risk factor for pregnancy loss and preeclampsia is consistent with a hypothesis that increased tHcy results in abnormalities of the placental vasculature.
Rationale, Design, and Methodology of the Women’s Genome Health Study: A Genome-Wide Association Study of More Than 25 000 Initially Healthy American Women
Authors: Ridker Paul M , Chasman Daniel I , Zee Robert Y L , Parker Alex , Rose Lynda , Cook Nancy R , Buring Julie E ,   for the Women’s Genome Health Study Working Group
Published: December 2007

The primary aim of the Women’s Genome Health Study (WGHS) is to create a comprehensive, fully searchable genome-wide database of >360 000 single nucleotide polymorphisms among at least 25 000 initially healthy American women participating in the ongoing NIH-funded Women’s Health Study (WHS). These women have already been followed over a 12-year period for major incident health events including but not limited to myocardial infarction, stroke, cancer, diabetes, osteoporosis, venous-thromboembolism, cognitive decline, and common visual disorders such as age- related macular degeneration and cataracts. Investigations within the WGHS will seek to identify relevant patterns of genetic polymorphism that predict future disease states in otherwise healthy American women, and to evaluate patterns of genetic polymorphism that relate to multiple intermediate phenotypes including blood-based determinants of disease that were measured at baseline for each study participant. By linking genome-wide data to the existing epidemiologic databank of the parent WHS, which includes comprehensive dietary, behavioral, and traditional exposure data on each participant since cohort inception in 1992, the WGHS will also allow exploration of gene-environment and gene-gene interactions as they relate to incident disease states. Thus, with continued follow-up of the WHS, the WGHS provides a unique scientific resource—a full-cohort, prospective, genome-wide association study among initially healthy American women.
Power and personality: politicians on the World Wide Web
Authors: Bondebjerg Ib
Published: December 2007

This article is a comparative analysis of the websites of four of the most powerful leaders in the world: two presidents (George W. Bush and Jacques Chirac) and two prime ministers (Angela Merkel and Tony Blair). The analysis focuses on the structure and content of the websites; the
relation between textual elements, visual and other elements; the types of information given; the way it addresses users; and to what degree and in what forms interactive potentials for dialogue are constructed. The ways in which the relation between the official, political person, the representative
of the nation and the more personal aspects of these politicians are constructed are key focus points seen in the more theoretical context of mediated politics and the mediation of the political personae in the present media-saturated society. The comparative analysis shows significant national
differences in the way the political leaders are linked to national symbols and national cultural identity. The last part of the article discusses the empirical data on the rising importance of political websites for the general population.
Online debate on digital aesthetics and communication
Authors: Fetveit Arild , Stald Gitte
Published: December 2007

Jay Bolter, Lev Manovich, Klaus Bruhn Jensen, Arild Fetveit, and Gitte Stald