Showing papers by "University of Pennsylvania published in 2000"
TL;DR: A checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology, including background, search strategy, methods, results, discussion, and conclusion should improve the usefulness ofMeta-an analyses for authors, reviewers, editors, readers, and decision makers.
Abstract: ObjectiveBecause of the pressure for timely, informed decisions in public health
and clinical practice and the explosion of information in the scientific literature,
research results must be synthesized. Meta-analyses are increasingly used
to address this problem, and they often evaluate observational studies. A
workshop was held in Atlanta, Ga, in April 1997, to examine the reporting
of meta-analyses of observational studies and to make recommendations to aid
authors, reviewers, editors, and readers.ParticipantsTwenty-seven participants were selected by a steering committee, based
on expertise in clinical practice, trials, statistics, epidemiology, social
sciences, and biomedical editing. Deliberations of the workshop were open
to other interested scientists. Funding for this activity was provided by
the Centers for Disease Control and Prevention.EvidenceWe conducted a systematic review of the published literature on the
conduct and reporting of meta-analyses in observational studies using MEDLINE,
Educational Research Information Center (ERIC), PsycLIT, and the Current Index
to Statistics. We also examined reference lists of the 32 studies retrieved
and contacted experts in the field. Participants were assigned to small-group
discussions on the subjects of bias, searching and abstracting, heterogeneity,
study categorization, and statistical methods.Consensus ProcessFrom the material presented at the workshop, the authors developed a
checklist summarizing recommendations for reporting meta-analyses of observational
studies. The checklist and supporting evidence were circulated to all conference
attendees and additional experts. All suggestions for revisions were addressed.ConclusionsThe proposed checklist contains specifications for reporting of meta-analyses
of observational studies in epidemiology, including background, search strategy,
methods, results, discussion, and conclusion. Use of the checklist should
improve the usefulness of meta-analyses for authors, reviewers, editors, readers,
and decision makers. An evaluation plan is suggested and research areas are
explored.
17,663 citations
TL;DR: Understanding of the complex signaling networks downstream from RTKs and how alterations in these networks are translated into cellular responses provides an important context for therapeutically countering the effects of pathogenic RTK mutations in cancer and other diseases.
7,056 citations
TL;DR: In this article, the authors provide empirical evidence using large-sample survey data to show that when firms build relational capital in conjunction with an integrative approach to managing conflict, they are able to achieve both objectives simultaneously.
Abstract: One of the main reasons that firms participate in alliances is to learn know-how and capabilities from their alliance partners. At the same time firms want to protect themselves from the opportunistic behavior of their partner to retain their own core proprietary assets. Most research has generally viewed the achievement of these objectives as mutually exclusive. In contrast, we provide empirical evidence using large-sample survey data to show that when firms build relational capital in conjunction with an integrative approach to managing conflict, they are able to achieve both objectives simultaneously. Relational capital based on mutual trust and interaction at the individual level between alliance partners creates a basis for learning and know-how transfer across the exchange interface. At the same time, it curbs opportunistic behavior of alliance partners, thus preventing the leakage of critical know-how between them. Copyright © 2000 John Wiley & Sons, Ltd.
3,029 citations
TL;DR: In this paper, the authors study German firms that have switched from the German to an international reporting regime (1AS or U.S. GAAP) and show that proxies for the information asymmetry component of the cost of capital for the switching firms, namely, the bid-ask spread and trading volume behave in the predicted direction compared to firms employing the German reporting regime.
Abstract: Economic theory suggests that a commitment by a firm to increased levels of disclosure should lower the information asymmetry component of the firm's cost of capital. But while the theory is compelling, so far empirical results relating increased levels of disclosure to measurable economic benefits have been mixed. One explanation for the mixed results among studies using data from firms publicly registered in the United States is that, under current U.S. reporting standards, the disclosure environment is already rich. In this paper, we study German firms that have switched from the German to an international reporting regime (1AS or U.S. GAAP), thereby committing themselves to increased levels of disclosure. We show that proxies for the information asymmetry component of the cost of capital for the switching firmsnamely, the bid-ask spread and trading volume-behave in the predicted direction compared to firms employing the German reporting regime.
2,984 citations
Posted Content•
TL;DR: In this article, the authors show that news about growth rates significantly alter agent's perceptions regarding long run expected growth rates and growth rate uncertainty, which leads to a large equity risk premium, low risk free interest rate, and large market volatility.
Abstract: We model dividend and consumption growth rates as containing a small long-run predictable component and economic uncertainty (i.e., growth rate volatility) as being time-varying. The magnitudes of the predictable variation and changing volatility in growth rates, as in the data, are quite small. These growth rate dynamics, for which we provide empirical support, in conjunction with plausible parameter configurations of the Epstein and Zin (1989) preferences can explain key observed asset markets phenomena. In particular, we show that the model can justify the observed equity premium, the low risk free rate, and the ex-post volatilities of the market return, real risk free rate, and the price-dividend ratio. As in the data, the model also implies that dividend yields predict returns and that market return volatility is stochastic. The main economic insight we capture is that news about growth rates significantly alter agent's perceptions regarding long run expected growth rates and growth rate uncertainty--in equilibrium, this leads to a large equity risk premium, low risk free interest rate, and large market volatility.
2,852 citations
TL;DR: The authors examined the relationship between managers' understanding of the world and the accumulation of organizational capabilities through an in-depth case study of the response of the Polaroid Corporation to the ongoing shift from analog to digital imaging.
Abstract: There is empirical evidence that established firms often have difficulty adapting to radical technological change. Although prior work in the evolutionary tradition emphasizes the inertial forces associated with the local nature of learning processes, little theoretical attention has been devoted in this tradition to understanding how managerial cognition affects the adaptive intelligence of organizations. Through an in-depth case study of the response of the Polaroid Corporation to the ongoing shift from analog to digital imaging, we expand upon this work by examining the relationship between managers' understanding of the world and the accumulation of organizational capabilities. The Polaroid story clearly illustrates the importance of managerial cognitive representations in directing search processes in a new learning environment, the evolutionary trajectory of organizational capabilities, and ultimately processes of organizational adaptation. Copyright © 2000 John Wiley & Sons, Ltd.
2,275 citations
TL;DR: In traditional supply chain inventory management, orders are the only information firms exchange, but information technology now allows firms to share demand and inventory data quickly and inexpensively, and it is concluded that implementing information technology to accelerate and smooth the physical flow of goods through a supply chain is significantly more valuable.
Abstract: In traditional supply chain inventory management, orders are the only information firms exchange, but information technology now allows firms to share demand and inventory data quickly and inexpensively. We study the value of sharing these data in a model with one supplier, N identical retailers, and stationary stochastic consumer demand. There are inventory holding costs and back-order penalty costs. We compare a traditional information policy that does not use shared information with a full information policy that does exploit shared information. In a numerical study we find that supply chain costs are 2.2% lower on average with the full information policy than with the traditional information policy, and the maximum difference is 12.1%. We also develop a simulation-based lower bound over all feasible policies. The cost difference between the traditional information policy and the lower bound is an upper bound on the value of information sharing: In the same study, that difference is 3.4% on average, and no more than 13.8%. We contrast the value of information sharing with two other benefits of information technology, faster and cheaper order processing, which lead to shorter lead times and smaller batch sizes, respectively. In our sample, cutting lead times nearly in half reduces costs by 21% on average, and cutting batches in half reduces costs by 22% on average. For the settings we study, we conclude that implementing information technology to accelerate and smooth the physical flow of goods through a supply chain is significantly more valuable than using information technology to expand the flow of information.
1,790 citations
TL;DR: This paper used computer simulations to examine the role and interrelationship between search processes that are forward-looking based on actors' cognitive map of action-outcome linkages, and those that are backward-looking, or experience based.
Abstract: We used computer simulations to examine the role and interrelationship between search processes that are forward-looking, based on actors' cognitive map of action-outcome linkages, and those that are backward-looking, or experience based. Cognition was modeled as a simple, low-dimensional representation of a more complex, higher dimensional fitness landscape. Results show that, although crude, these representations still act as a powerful guide to initial search efforts and usefully constrain the direction of subsequent experiential search. Changing a cognitive representation itself can act as an important mode of adaptation, effectively resulting in the sequential allocation of attention to different facets of the environment. This virtue of shifting cognitive representation, however, may be offset by the loss of tacit knowledge associated with the prior cognition.
1,781 citations
TL;DR: In this paper, a process model of knowledge transfer is proposed, which identifies stages of transfer and factors that are expected to correlate with difficulty at different stages of the transfer, and measures of stickiness are developed for each stage to explore the predictive power of different factors at different levels of the process.
1,763 citations
TL;DR: This article will review postinfarction remodeling, pathophysiological mechanisms, and therapeutic intervention in left ventricular remodeling and provide important insights into the remodeling process and a rationale for future therapeutic strategies.
Abstract: Left ventricular remodeling is the process by which ventricular size, shape, and function are regulated by mechanical, neurohormonal, and genetic factors.1 2 Remodeling may be physiological and adaptive during normal growth or pathological due to myocardial infarction, cardiomyopathy, hypertension, or valvular heart disease (Figure 1⇓). This article will review postinfarction remodeling, pathophysiological mechanisms, and therapeutic intervention.
Figure 1.
Diagrammatic representation of the many factors involved in the pathophysiology of ventricular remodeling. ECM indicates extracellular matrix; RAAS, renin-angiotensin-aldosterone system; CO, cardiac output; SVR, systemic vascular resistance; LV, left ventricular; and AII, angiotensin II.
### Postinfarction Left Ventricular Remodeling
The acute loss of myocardium results in an abrupt increase in loading conditions that induces a unique pattern of remodeling involving the infarcted border zone and remote noninfarcted myocardium. Myocyte necrosis and the resultant increase in load trigger a cascade of biochemical intracellular signaling processes that initiates and subsequently modulates reparative changes, which include dilatation, hypertrophy, and the formation of a discrete collagen scar. Ventricular remodeling may continue for weeks or months until the distending forces are counterbalanced by the tensile strength of the collagen scar. This balance is determined by the size, location, and transmurality of the infarct, the extent of myocardial stunning, the patency of the infarct-related artery, and local tropic factors.1 3
The myocardium consists of 3 integrated components: myocytes, extracellular matrix, and the capillary microcirculation that services the contractile unit assembly. Consideration of all 3 components provides important insights into the remodeling process and a rationale for future therapeutic strategies. The cardiomyocyte is terminally differentiated and develops tension by shortening. The extracellular matrix provides a stress-tolerant, viscoelastic scaffold consisting of type I and type III collagen that couples myocytes and maintains the spatial relations between the myofilaments and their capillary microcirculation.4 5 The collagen framework couples adjacent myocytes by intercellular struts that …
1,737 citations
TL;DR: The observation that a solid-oxide fuel cell can be operated on dry hydrocarbons, including liquid fuels, without reforming, suggests that this type of fuel cell could provide an alternative to hydrogen-based fuel-cell technologies.
Abstract: The direct electrochemical oxidation of dry hydrocarbon fuels to generate electrical power has the potential to accelerate substantially the use of fuel cells in transportation and distributed-power applications1. Most fuel-cell research has involved the use of hydrogen as the fuel, although the practical generation and storage of hydrogen remains an important technological hurdle2. Methane has been successfully oxidized electrochemically3,4,5,6, but the susceptibility to carbon formation from other hydrocarbons that may be present or poor power densities have prevented the application of this simple fuel in practical applications1. Here we report the direct, electrochemical oxidation of various hydrocarbons (methane, ethane, 1-butene, n-butane and toluene) using a solid-oxide fuel cell at 973 and 1,073 K with a composite anode of copper and ceria (or samaria-doped ceria). We demonstrate that the final products of the oxidation are CO2 and water, and that reasonable power densities can be achieved. The observation that a solid-oxide fuel cell can be operated on dry hydrocarbons, including liquid fuels, without reforming, suggests that this type of fuel cell could provide an alternative to hydrogen-based fuel-cell technologies.
TL;DR: It is shown that recruitment of the p160 class of coactivators is sufficient for gene activation and for the growth stimulatory actions of estrogen in breast cancer supporting a model in which ER cofactors play unique roles in estrogen signaling.
TL;DR: In this article, the authors forges an explicit link between an objective measure of political constraints and variation in cross-national growth rates, and derives a new measure for political constraints from a simple spatial model of political interaction that incorporates information on the number of independent branches of government with veto power and the distribution of preferences across and within those branches.
Abstract: This article forges an explicit link between an objective measure of political constraints and variation in cross-national growth rates. It derives a new measure of political constraints from a simple spatial model of political interaction that incorporates information on the number of independent branches of government with veto power and the distribution of preferences across and within those branches. The derived variable is found to have a statistically and economically significant impact on growth rates using simple ordinary least squares, three-stage least squares and generalized method of moments estimation techniques.
TL;DR: In this paper, the authors evaluate the literature that assesses the usefulness of accounting numbers on their stock market value association and conclude that the literature provides little insight for standard-setting purposes.
Abstract: We evaluate the literature that, for standard-setting purposes, assesses the usefulness of accounting numbers on their stock market value association. For several reasons we conclude the literature provides little insight for standard setting. First, the association criterion has no theory of accounting or standard setting supporting it. Standard setters' descriptions of their objectives and accounting practice are both inconsistent with the criterion. Important forces shaping accounting standards and practice are ignored. Second, many tests in the literature rely on valuation models that omit important factors and many studies do not provide links between valuation model inputs and accounting numbers. Finally, there are a variety of significant econometric issues in the studies.
TL;DR: Confocal microscopy was used to directly observe three-dimensional dynamics of particles in colloidal supercooled fluids and colloidal glasses; connected clusters of these mobile particles could be identified; and the cluster size distribution, structure, and dynamics were investigated.
Abstract: Confocal microscopy was used to directly observe three-dimensional dynamics of particles in colloidal supercooled fluids and colloidal glasses. The fastest particles moved cooperatively; connected clusters of these mobile particles could be identified; and the cluster size distribution, structure, and dynamics were investigated. The characteristic cluster size grew markedly in the supercooled fluid as the glass transition was approached, in agreement with computer simulations; at the glass transition, however, there was a sudden drop in their size. The clusters of fast-moving particles were largest near the α-relaxation time scale for supercooled colloidal fluids, but were also present, albeit with a markedly different nature, at shorter β-relaxation time scales, in both supercooled fluid and glass colloidal phases.
Howard Hughes Medical Institute1, Celera Corporation2, University of California, Berkeley3, Harvard University4, University of Pennsylvania5, Wellcome Trust6, Stanford University7, Fred Hutchinson Cancer Research Center8, National Institutes of Health9, Lawrence Berkeley National Laboratory10, University of Leeds11, University of California, San Diego12, California Institute of Technology13, Massachusetts Institute of Technology14, BC Cancer Research Centre15, University of Maryland, Baltimore16, Centre national de la recherche scientifique17, University of California, San Francisco18, Columbia University19, Baylor College of Medicine20
TL;DR: The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.
Abstract: A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.
TL;DR: The selective and specific nitration of alpha-synuclein in these disorders provides evidence to directly link oxidative and nitrative damage to the onset and progression of neurodegenerative synucleinopathies.
Abstract: Aggregated α-synuclein proteins form brain lesions that are hallmarks of neurodegenerative synucleinopathies, and oxidative stress has been implicated in the pathogenesis of some of these disorders. Using antibodies to specific nitrated tyrosine residues in α-synuclein, we demonstrate extensive and widespread accumulations of nitrated α-synuclein in the signature inclusions of Parkinson's disease, dementia with Lewy bodies, the Lewy body variant of Alzheimer's disease, and multiple system atrophy brains. We also show that nitrated α-synuclein is present in the major filamentous building blocks of these inclusions, as well as in the insoluble fractions of affected brain regions of synucleinopathies. The selective and specific nitration of α-synuclein in these disorders provides evidence to directly link oxidative and nitrative damage to the onset and progression of neurodegenerative synucleinopathies.
Journal Article•
Lawrence Berkeley National Laboratory1, University of Zurich2, Stanford University3, College of William & Mary4, University of Genoa5, University of Urbino6, CERN7, Budker Institute of Nuclear Physics8, Cornell University9, Argonne National Laboratory10, ETH Zurich11, Tata Institute of Fundamental Research12, Hillsdale College13, Spanish National Research Council14, Tohoku University15, Ohio State University16, University of California, San Diego17, University of California, Berkeley18, Aix-Marseille University19, University of Minnesota20, University of Alabama21, University of Helsinki22, California Institute of Technology23, George Washington University24, University of Kansas25, RWTH Aachen University26, Boston University27, University of California, Los Angeles28, Institut des Hautes Études Scientifiques29, University of Pennsylvania30, University of Tokyo31, University of Delaware32, Fermilab33, Carnegie Mellon University34, University of California, Santa Cruz35, Lawrence Livermore National Laboratory36, University of Washington37, Karlsruhe Institute of Technology38, Heidelberg University39, Florida State University40, Carleton University41, National Science Foundation42, University of Mainz43, University of Edinburgh44, University of Chicago45, Brookhaven National Laboratory46, Kent State University47, Paul Scherrer Institute48, Max Planck Society49, Massachusetts Institute of Technology50, Nagoya University51, Harvard University52
TL;DR: In this article, a biennial review summarizes much of particle physics using data from previous editions., plus 2778 new measurements from 645 papers, including measurements of gauge bosons, leptons, quarks, mesons, and baryons.
Abstract: This biennial Review summarizes much of particle physics. Using data from previous editions., plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors., probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on CKM quark-mixing matrix, V-ud & V-us, V-cb & V-ub, top quark, muon anomalous magnetic moment, extra dimensions, particle detectors, cosmic background radiation, dark matter, cosmological parameters, and big bang cosmology.
TL;DR: In this paper, the potential energies of interaction between two parallel, infinitely long carbon nanotubes of the same diameter, and between a nanotube in various arrangements, were computed by assuming a continuous distribution of atoms on the tube and ball surfaces and using a Lennard-Jones (LJ) carbon-carbon potential.
Abstract: The potential energies of interaction between two parallel, infinitely long carbon nanotubes of the same diameter, and between ${\mathrm{C}}_{60}$ and a nanotube in various arrangements, were computed by assuming a continuous distribution of atoms on the tube and ball surfaces and using a Lennard-Jones (LJ) carbon-carbon potential. The constants in the LJ potential are different for graphene-graphene and ${\mathrm{C}}_{60}\ensuremath{-}{\mathrm{C}}_{60}$ interactions. From these, the constants for tube-${\mathrm{C}}_{60}$ interactions were estimated using averaging rules from the theory of dispersion forces. For tubes in ropes, the cohesive energy per unit length, the compressibility, and the equilibrium separation distance were computed as a function of tube radius. For a ${\mathrm{C}}_{60}$ molecule interacting with tubes, the binding energy inside a tube was much higher than on a tube or at the tube mouth. Within a tube, the binding energy was highest at a spherically capped end. The potential energies for tubes of all radii, as well as for interactions between ${\mathrm{C}}_{60}$ molecules, for a ${\mathrm{C}}_{60}$ molecule outside of a nanotube, between a ${\mathrm{C}}_{60}$ molecule and a graphene sheet, and between graphene sheets, all fell on the same curve when plotted in terms of certain reduced parameters. Because of this, all the potentials can be represented by a simple analytic form, thereby greatly simplifying all computations of van der Waals interactions in graphitic systems. Binding-energy results were all consistent with the recently proposed mechanism of peapod formation based on transmission electron microscopy experiments.
TL;DR: The discovery of leptin in the mid-1990s has focused attention on the role of proteins secreted by adipose tissue, which is also involved in the regulation of neuroendocrine and immune function and the metabolic and cardiovascular complications associated with obesity.
Abstract: Adipose tissue is a complex, essential, and highly active metabolic and endocrine organ. Besides adipocytes, adipose tissue contains connective tissue matrix, nerve tissue, stromovascular cells, and immune cells. Together these components function as an integrated unit. Adipose tissue not only responds to afferent signals from traditional hormone systems and the central nervous system but also expresses and secretes factors with important endocrine functions. These factors include leptin, other cytokines, adiponectin, complement components, plasminogen activator inhibitor-1, proteins of the renin-angiotensin system, and resistin. Adipose tissue is also a major site for metabolism of sex steroids and glucocorticoids. The important endocrine function of adipose tissue is emphasized by the adverse metabolic consequences of both adipose tissue excess and deficiency. A better understanding of the endocrine function of adipose tissue will likely lead to more rational therapy for these increasingly prevalent disorders. This review presents an overview of the endocrine functions of adipose tissue. (J Clin Endocrinol Metab 89: 2548–2556, 2004)
TL;DR: The evidence strongly suggests that the numerous mechanisms of quinone toxicity can be correlated with the known pathology of the parent compound(s), including benzene, polycyclic aromatic hydrocarbons, estrogens, and catecholamines.
Abstract: Quinones represent a class of toxicological intermediates which can create a variety of hazardous effects in vivo, including acute cytotoxicity, immunotoxicity, and carcinogenesis. The mechanisms by which quinones cause these effects can be quite complex. Quinones are Michael acceptors, and cellular damage can occur through alkylation of crucial cellular proteins and/or DNA. Alternatively, quinones are highly redox active molecules which can redox cycle with their semiquinone radicals, leading to formation of reactive oxygen species (ROS), including superoxide, hydrogen peroxide, and ultimately the hydroxyl radical. Production of ROS can cause severe oxidative stress within cells through the formation of oxidized cellular macromolecules, including lipids, proteins, and DNA. Formation of oxidatively damaged bases such as 8-oxodeoxyguanosine has been associated with aging and carcinogenesis. Furthermore, ROS can activate a number of signaling pathways, including protein kinase C and RAS. This review explore...
Book•
01 Jan 2000TL;DR: In the United States and the United Kingdom competitive markets dominate the financial landscape, whereas in France, Germany, and Japan banks have traditionally played the most important role as discussed by the authors. But the form of these financial systems varies widely.
Abstract: Financial systems are crucial to the allocation of resources in a modern economy. They channel household savings to the corporate sector and allocate investment funds among firms; they allow intertemporal smoothing of consumption by households and expenditures by firms; and they enable households and firms to share risks. These functions are common to the financial systems of most developed economies. Yet the form of these financial systems varies widely. In the United States and the United Kingdom competitive markets dominate the financial landscape, whereas in France, Germany, and Japan banks have traditionally played the most important role. Why do different countries have such different financial systems? Is one system better than all the others? Do different systems merely represent alternative ways of satisfying similar needs? Is the current trend toward market-based systems desirable? Franklin Allen and Douglas Gale argue that the view that market-based systems are best is simplistic. A more nuanced approach is necessary. For example, financial markets may be bad for risk sharing; competition in banking may be inefficient; financial crises can be good as well as bad; and separation of ownership and control can be optimal. Financial institutions are not simply veils, disguising the allocation mechanism without affecting it, but are crucial to overcoming market imperfections. An optimal financial system relies on both financial markets and financial intermediaries.
University of California, Irvine1, University of Pennsylvania2, University of Colorado Denver3, Technische Universität München4, Yale University5, Hoffmann-La Roche6, State University of New York System7, University of Michigan8, Collège de France9, National Institutes of Natural Sciences, Japan10, Colorado State University11, University College London12, University of Washington13
TL;DR: The present alphabetical nomenclature does not reveal the structural relationships among the α1 subunits of Ca2+ channels, but it is apparent that these two alphabeticals will overlap at α1L, which may not mediate an L-type Ca2- current and therefore may create confusion.
TL;DR: In this paper, the authors propose that part of the value of a firm derives from its participation in a network that emerges from the operation of generative rules that instruct the decision to cooperate.
Abstract: The imputation problem is how to account for the sources of the value of the firm. I propose that part of the value of the firm derives from its participation in a network that emerges from the operation of generative rules that instruct the decision to cooperate. Whereas the value of firm-level capabilities is coincidental with the firm as the unit of accrual, ownership claims to the value of coordination in a network pit firms potentially in opposition with one another. We analyze the work on network structure to suggest two types of mechanisms by which rents are distributed. This approach is applied to an analysis of the Toyota Production System to show how a network emerged, the rents were divided to support network capabilities, and capabilities were transferred to the United States. Copyright © 2000 John Wiley & Sons, Ltd.
TL;DR: In this article, the authors re-examine, in light of recent developments, the reasoned action perspective inherent in the expectancy-value model of attitude and in the theory of planned behavior.
Abstract: The chapter re-examines, in light of recent developments, the reasoned action perspective inherent in the expectancy-value model of attitude and in the theory of planned behavior. According to this perspective, people's attitudes follow spontaneously and consistently from beliefs accessible in memory and then guide corresponding behavior. The number and types of beliefs that are accessible vary with motivation and ability to process attitude-relevant information and with the context. Based on these considerations, it is shown that the reasoned action perspective is compatible with evidence for automatic processes in the activation of attitudes and behavior, and with the finding that attitudes can vary with the context in which they are expressed. Implications for the attitude-behavior relation and for the role of habit in human behavior are discussed.
TL;DR: Bax and Bak have overlapping roles in the regulation of apoptosis during mammalian development and tissue homeostasis and are found to be developmentally normal and reproductively fit.
TL;DR: The intrinsic high-field transport properties of metallic single-wall carbon nanotubes are measured using low-resistance electrical contacts and it is shown that the current-voltage characteristics can be explained by considering optical or zone-boundary phonon emission as the dominant scattering mechanism at high field.
Abstract: Using low-resistance electrical contacts, we have measured the intrinsic high-field transport properties of metallic single-wall carbon nanotubes. Individual nanotubes appear to be able to carry currents with a density exceeding 10(9) A/cm(2). As the bias voltage is increased, the conductance drops dramatically due to scattering of electrons. We show that the current-voltage characteristics can be explained by considering optical or zone-boundary phonon emission as the dominant scattering mechanism at high field.
TL;DR: The previous conceptual analysis of transitions is extended and refined by drawing on the results of five different research studies that have examined transitions using an integrative approach to theory development.
Abstract: Changes in health and illness of individuals create a process of transition, and clients in transition tend to be more vulnerable to risks that may in turn affect their health. Uncovering these risks may be enhanced by understanding the transition process. As a central concept of nursing, transition has been analyzed, its components identified, and a framework to articulate and to reflect the relationship between these components has been defined. In this article, the previous conceptual analysis of transitions is extended and refined by drawing on the results of five different research studies that have examined transitions using an integrative approach to theory development. The emerging middle-range theory of transitions consists of types and patterns of transitions, properties of transition experiences, facilitating and inhibiting conditions, process indicators, outcome indicators, and nursing therapeutics. The diversity, complexity, and multiple dimensionality of transition experiences need to be further explored and incorporated in future research and nursing practice related to transitions.
TL;DR: In this paper, the authors develop a framework that provides a simple, explicit economic mechanism for understanding skill-biased technological change in terms of observable variables and use the framework to evaluate the fraction of variation in the skill premium that can be accounted for by changes in observed factor quantities.
Abstract: The supply and price of skilled labor relative to unskilled labor have changed dramatically over the postwar period. The relative quantity of skilled labor has increased substantially, and the skill premium, which is the wage of skilled labor relative to that of unskilled labor, has grown significantly since 1980. Many studies have found that accounting for the increase in the skill premium on the basis of observable variables is difficult and have concluded implicitly that latent skill-biased technological change must be the main factor responsible. This paper examines that view systematically. We develop a framework that provides a simple, explicit economic mechanism for understanding skill-biased technological change in terms of observable variables, and we use the framework to evaluate the fraction of variation in the skill premium that can be accounted for by changes in observed factor quantities. We find that with capital-skill complementarity, changes in observed inputs alone can account for most of the variations in the skill premium over the last 30 years.
TL;DR: In this article, the effect of political hazards on the choice of market entry mode varies across multinational firms based on the extent to which they face expropriation hazards from their potential joint-venture partners in the host country (the level of contractual hazards).
Abstract: This article posits that the effect of political hazards on the choice of market entry mode varies across multinational firms based on the extent to which they face expropriation hazards from their potential joint-venture partners in the host country (the level of contractual hazards). As political hazards increase, the multinational faces an increasing threat of opportunistic expropriation by the government. Partnering with host-country firms that possess a comparative advantage in interactions with the host-country government can safeguard against this hazard. However, as contractual hazards increase, the potential benefit to the joint-venture partner of manipulating the political system for it's own benefit at the expense of the multinational increases as well, thereby diminishing the hazard-mitigating benefit of forming a joint venture. A two-stage bivariate probit estimation technique is used to test these hypotheses on a sample of 3,389 overseas manufacturing operations by 461 firms in 112 countries. Copyright 2000 by Oxford University Press.