bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenous circadian rhythm in an index of cardiac vulnerability independent of changes in behavior
Authors: Hu Kun , Ivanov Plamen Ch. , Hilton Michael F. , Chen Zhi , Ayers R. Timothy , Stanley H. Eugene , Shea Steven A.
Published: December 2004

There exists a robust day/night pattern in the incidence of adverse cardiac events with a peak at ≈10 a.m. This peak traditionally has been attributed to day/night patterns in behaviors affecting cardiac function in vulnerable individuals. However, influences from the endogenous circadian pacemaker independent from behaviors may also affect cardiac control. Heartbeat dynamics under healthy conditions exhibit robust complex fluctuations characterized by self-similar temporal structures, which break down under pathologic conditions. We hypothesize that these dynamical features of the healthy human heartbeat have an endogenous circadian rhythm that brings the features closer to those observed under pathologic conditions at the endogenous circadian phase corresponding to ≈10 a.m. We investigate heartbeat dynamics in healthy subjects recorded throughout a 10-day protocol wherein the sleep/wake and behavior cycles are desynchronized from the endogenous circadian cycle, enabling assessment of circadian factors while controlling for behavior-related factors. We demonstrate that the scaling exponent characterizing temporal correlations in heartbeat dynamics does exhibit a significant circadian rhythm (with a sharp peak at the circadian phase corresponding to ≈10 a.m.), which is independent from scheduled behaviors and mean heart rate. Cardiac dynamics under pathologic conditions such as congestive heart failure also are associated with a larger value of the scaling exponent of the interbeat interval. Thus, the sharp peak in the scaling exponent at the circadian phase coinciding with the period of highest cardiac vulnerability observed in epidemiological studies suggests that endogenous circadian-mediated influences on cardiac control may be involved in the day/night pattern of adverse cardiac events in vulnerable individuals.
Reactive oxygen signaling and MAPK activation distinguish Epstein–Barr Virus (EBV)-positive versus EBV-negative Burkitt's lymphoma
Authors: Cerimele Francesca , Battle Traci , Lynch Rebecca , Frank David A. , Murad Emma , Cohen Cynthia , Macaron Nada , Sixbey John , Smith Kenneth , Watnick Randolph S. , Eliopoulos Aristidis , Shehata Bahig , Arbiser Jack L.
Published: December 2004

Burkitt's lymphoma (BL) is an aggressive B cell neoplasm, which is one of the most common neoplasms of childhood. It is highly widespread in East Africa, where it appears in endemic form associated with Epstein–Barr virus (EBV) infection, and around the world in a sporadic form in which EBV infection is much less common. In addition to being the first human neoplasm to be associated with EBV, BL is associated with a characteristic translocation, in which the Ig promoter is translocated to constitutively activate the c-myc oncogene. Although many BLs respond well to chemotherapy, a significant fraction fails to respond to therapy, leading to death. In this article, we demonstrate that EBV-positive BL expresses high levels of activated mitogen-activated protein kinase and reactive oxygen species (ROS), and that ROS directly regulate NF-κB activation. EBV-negative BLs exhibit activation of phosphoinositol 3-kinase, but do not have elevated levels of ROS. Elevated reactive oxygen may play a role in diverse forms of viral carcinogenesis in humans, including cancers caused by EBV, hepatitis B, C, and human T cell lymphotropic virus. Our findings imply that inhibition of ROS may be useful in the treatment of EBV-induced neoplasia.
Protection from mitochondrial complex II inhibitionin vitroandin vivoby Nrf2-mediated transcription
Authors: Calkins Marcus J. , Jakel Rebekah J. , Johnson Delinda A. , Chan Kaimin , Kan Yuet Wai , Johnson Jeffrey A.
Published: December 2004

Complex II inhibitors 3-nitropropionic acid (3NP) and malonate cause striatal damage reminiscent of Huntington's disease and have been shown to involve oxidative stress in their pathogenesis. Because nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent transcriptional activation by means of the antioxidant response element is known to coordinate the up-regulation of cytoprotective genes involved in combating oxidative stress, we investigated the significance of Nrf2 in complex II-induced toxicity. We found that Nrf2-deficient cells and Nrf2 knockout mice are significantly more vulnerable to malonate and 3NP and demonstrate increased antioxidant response element (ARE)-regulated transcription mediated by astrocytes. Furthermore, ARE preactivation by means of intrastriatal transplantation of Nrf2-overexpressing astrocytes before lesioning conferred dramatic protection against complex II inhibition. These observations implicate Nrf2 as an essential inducible factor in the protection against complex II inhibitor-mediated neurotoxicity. These data also introduce Nrf2-mediated ARE transcription as a potential target of preventative therapy in neurodegenerative disorders such as Huntington's disease.
Study of Mechanical Behaviour of Austempered Ductile Iron using Self-consistent Model
Authors: Serban F. , Baczmanski A. , Labbe E. , Wierzbanowski K. , Lodini A.
Published: December 2004

In this paper, the mechanical properties of austempered ductile iron (ADI) are studied using neutron diffraction and mechanical tensile test. The elasto-plastic model was applied for interpretation of the experimental results. This model treats a given number of polycrystalline grains having different lattice orientations. The calculations are based on the modelling of the processes occurring inside and between grains. As a result, the mechanical behaviour of the polycrystalline material can be studied at various scales.
Residual Stress Prediction for the Inertia Welding Process
Authors: Wang L. , Preuss M. , Withers P.J. , Baxter G.J. , Wilson P.
Published: December 2004

Predictions of residual stresses in inertia friction welded Ni-base superalloys have been carried out using a commercial finite element code (DEFORM) combined with an energy balance approach and a 2D axisymmetric formulation. A coupled thermal and mechanical finite element model has been created. During inertia welding trials of RR1000, a high γ′ Ni-base superalloy, the rotational velocity and upset history curves were recorded. From these data the heat flux (the rate of energy input) through the weld interface was inferred and together with the upsetting rate input into the model as evolving boundary conditions. The coupled thermal and mechanical analysis leads to the prediction of the thermal history and the residual stresses generated during cooling. The validation of the model has been undertaken by comparing the predicted residual stresses with those measured using neutron diffraction. The comparison between predicted and measured stresses is in good agreement.
A Spatially-resolved Synchrotron Diffraction Method for Evaluating Impact-induced Residual Stresses
Authors: Boyce B.L. , Mehta A. , Peters J.O. , Ritchie R.O.
Published: December 2004

Turbine engine fatigue failures associated with foreign object damage (FOD) are thought to be driven, in part, by the impact-induced residual stresses. The present work summarizes the use of spatially-resolved synchrotron X-ray diffraction to quantify the residual stresses, residual elastic Poisson strain, and plastic strain of simulated FOD in a Ti-6Al-4V alloy. A 300 × 300 µm low-divergence synchrotron source provides adequate spatial resolution for the interrogation of impact craters 2–6 mm in diameter, while still sampling a sufficient number of grains for monochromatic polycrystalline diffraction experiments. The observed residual stresses are compared to continuum- based numerical predictions. Both the formation of microcracks at high impact velocities (300 m/s), and the Bauschinger-induced fatigue relaxation of the initial residual stresses must be taken into account to adequately address the driving force for fatigue failure.
Residual Stresses Around Welds in Nickel-based Superalloys
Authors: Korsunsky Alexander M. , James Karen E.
Published: December 2004

Welding of nickel-based superalloys is employed in the manufacture of many important components of the jet engine, such as combustor casings, compressor disc assemblies, etc. Welds induce microstructural modification in the weld seam and the heat affected zone (HAZ) which generally reduce the fatigue resistance compared to that of the parent metal. Welds also generate significant residual stresses, both locally due to combination of solidification shrinkage and high temperature plastic deformation, and also globally through the general tensioning of the structure. Diffraction of high energy synchrotron X-rays is very well suited to the task of accurate non-destructive evaluation of residual stresses near welds in thin walled components assembled by welding nickel superalloys. Residual stresses induced by linear and annular welds produced in test pieces made from C263 and IN718 nickel based alloys under different conditions are evaluated, and the effects of various heat treatments on stress state are discussed.
In situ Investigation of Plastic Deformation by Neutrons and Positrons—a Novel Approach
Authors: Priesmeyer Hans Georg , Bokuchava Gizo
Published: December 2004

When characterizing residual stresses by neutron diffraction, neutron absorption is always a competing process. It leads to the emission of high-energy, so-called prompt gamma radiation, which in turn produces positrons within the bulk of the specimen. The decay of these antiparticles and the resulting annihilation radiation are influenced by material properties like defects. Plastic deformation and resulting increase of the dislocation density leads in the neutron scattering case to an increase in the mosaic spread of the BRAGG reflections, while on the other hand, the 511 keV line of the annihilation radiation is also measurably broadened. Suitable collimation can assure that the information gathered by neutron diffraction comes from about the same gauge volume as the information from positron annihilation. It is the aim of this project to investigate the correlation between the width of the BRAGG reflections and the S-parameter, by which the width of the annihilation line is described as a function of the degree of plastic deformation. In this way, more can be learned about a material, since during strain measurements by diffraction additional information is available through simultaneous gamma-ray spectroscopy.
Residual Stresses in Cold-drawn Pearlite Rods by High Energy Synchrotron Radiation and Thermal Neutron Diffraction
Authors: Martinez-Perez M.L. , Mompean F.J. , Lin Peng R. , Ruiz J. , Borlado C.R. , Atienza J.M. , Gil-Sevillano J. , Garcia-Hernandez M. , Elices M. , Buslaps T.
Published: December 2004

Residual stresses in a cold drawn pearlitic rod of 18 mm in diameter have been studied by synchrotron radiation and neutron diffraction. The aim has been to characterise the complete residual stresses, including the total phase stresses, macrostresses and microstresses, due to cold drawing. Both techniques have revealed characteristic residual stress profiles along the radius of the rod for the ferrite phase, while the synchrotron radiation measurement has also produced residual stress profiles for the minor cementite phase (11% in weight). Good agreement between the two techniques has been observed. Residual macrostresses derived from the synchrotron measurement show a large variation from center to surface of the rod. The phase stresses for ferrite are dominated by the macrostresses. On the other hand, residual microstresses change less significantly along the radius of the rod and they prevail in the cementite phase.
Residual Stress Variation in Polycrystalline Copper during Recrystallization
Authors: Wierzbanowski K. , Baczmański A. , Wawszczak R. , Bacroix B. , Lodini A.
Published: December 2004

A general multi-reflection method was applied to determine the stress level in deformed and recrystallized polycrystalline copper samples. Different reflections hkl were simultaneously used in the fitting procedure. The anisotropic diffraction elastic constants were calculated using the self-consistent model and crystallographic texture. Important decrease of the first order residual stresses was observed during recovery and recrystallization. Independently, diffraction peak widths and intensities were examined for a few characteristic texture components during the recrystallization process. The importance of cubic orientation grains in the recrystallization process was confirmed.
Analysis of Residual Stresses Following Overloading of Cold Expanded Holes Using the X-ray Diffraction Technique and Finite Element Method
Authors: Nadri B. , Edwards L. , Fitzpatrick M.E. , Lodini A.
Published: December 2004

Cold working of holes is an effective method used to enhance the fatigue life of aerospace structures. The method introduces a zone of compressive residual stresses around the hole, which attenuates fatigue crack growth rates by reducing the effective stress intensity factor range. Therefore, the method reduces the tendency for fatigue cracks to initiate and grow under cyclic loading. Aircraft components are subjected to a complicated sequence of variable fatigue loading during service. Residual stresses around cold expanded holes can be relaxed because of the plastic deformation produced by in-service loading. We have studied the changes of residual stress distribution around a 4% cold expanded hole in 2024-T351 aluminium alloy, when the plate was subjected to different values of compressive overloading. Results from an FE model and X-ray diffraction measurements are presented and compared.
Use of Neutron and Synchrotron X-ray Diffraction for Non-destructive Evaluation of Weld Residual Stresses in Aluminium Alloys
Authors: Ganguly S. , Stelmukh V. , Fitzpatrick M.E. , Edwards L.
Published: December 2004

A full three-dimensional residual stress tensor was determined through a combination of neutron and synchrotron X-ray diffraction in a MIG welded Al2024 plate. The plate was first measured by synchrotron X-rays to determine the strain in the longitudinal (LD) and transverse directions (TD). Then the same plate was measured by pulsed neutrons for the transverse and normal strain directions. The stress-free lattice reference (d0) across the weld was obtained by measuring a comb sample of insufficient constraint to hold an internal residual stress field. The point-to-point corrected strain data of the three principal directions obtained was then combined to calculate the full three-dimensional residual stress tensor. The comparability of the processes was confirmed by comparing the strain observed in the transverse direction. The combination of these two different experiments enabled determination of a full through-thickness stress map across the weld.
Diffraction Stress Analysis in Thin Films and Coatings—Problems, Methods and Perspectives
Authors: Genzel CH.
Published: December 2004

X-ray stress analysis (XSA) at polycrystalline materials is usually a very time-consuming and demanding procedure. This especially applies to thin films and coatings with strong texture and/or steep residual stress gradients, the investigation of which is an important topic in modern materials science research, because these stresses are well-known to influence the properties of technical parts and electronic devices. Starting from some basic aspects concerning the possible residual stress states in thin layers, the paper is to give a compact survey of some of the most important problems in thin film stress analysis and the attempts at their solution.
Neutron Diffraction Studies of Si–Mn Trip Steel In Situ upon Thermomechanical Processing
Authors: Jenčuš P. , Lukáš P. , Muránsky O. , Zrník J. , Nový Z.
Published: December 2004

An excellent combination of high strength and formability can be obtained in a Si–Mn TRIP steels when processed by thermomechanical treatment consisting of high temperature deformation followed by isothermal holding in the bainite region and cooling to room temperature. Microstructure of these steels consists of ferrite, bainite and retained austenite. The combination of high strength and ductility is attributed to the transformation-induced plasticity (TRIP) effect resulting from the strain induced transformation of the retained austenite to martensite. These steels exhibit tensile strengths ranging 800–1000 MPa and elongation up to 30%. In the present paper, the influence of transformation conditions on volume fraction of ferrite and retained austenite in selected 0.2C1.9Si1.45Mn TRIP steel was investigated. Based on results of in situ high-temperature neutron diffraction experiments, the set of specimens was prepared and their transformation characteristics at room temperature were studied again by neutron diffraction experiments realized in situ upon tensile tests. The reported neutron diffraction method has been found as an efficient tool for characterization of austenite transformation proceeding in TRIP steels during combined thermomechanical treatments.
Impurities Effects on the Stored Elastic Energy in Cold-drawn Copper Wires
Authors: Jakani S. , Mathon M.H. , Benyoucef M. , Gerber PH. , Baudin T. , de Novion C.H.
Published: December 2004

After wire-drawing, the orientation dependent stored elastic energy was measured by neutron diffraction in electrolytic tough pitch copper (ETP 99.99% Cu) wires to improve the knowledge on the chemical composition effect on the static recrystallization behavior. The line broadening measurements on relatively low deformed samples have shown that the stored energy related to the main fibers—the texture develops major {111}〈uvw〉 and minor {001}〈uvw〉 fibers—is about 2–4 J/mol and that the stored energy ratio {111}〈uvw〉/{001}〈uvw〉 decreases when the total impurity content increases. Some hypotheses about the relationship between recrystallization process, recovery and stored energy are finally proposed, and some assumptions about the recrystallization mechanisms are set.
Product dynamics for homoclinic attractors
Authors: Ashwin Peter , Field Michael
Published: December 2004

Heteroclinic cycles may occur as structurally stable asymptotically stable attractors if there are invariant subspaces or symmetries of a dynamical system. Even for cycles between equilibria, it may be difficult to obtain results on the generic behaviour of trajectories converging to the cycle. For more–complicated cycles between chaotic sets, the non–trivial dynamics of the ‘nodes’ can interact with that of the ‘connections’. This paper focuses on some of the simplest problems for such dynamics where there are direct products of an attracting homoclinic cycle with various types of dynamics. Using a precise analytic description of a general planar homoclinic attractor, we are able to obtain a number of results for direct product systems.

We show that for flows that are a product of a homoclinic attractor and a periodic orbit or a mixing hyperbolic attractor, the product of the attractors is a minimal Milnor attractor for the product. On the other hand, we present evidence to show that for the product of two homoclinic attractors, typically only a small subset of the product of the attractors is an attractor for the product system.
Group-beneficial traits, frequency-dependent selection and genotypic diversity: an antibiotic resistance paradigm
Authors: Dugatkin Lee Alan , Perlin Michael , Lucas J. Scott , Atlas Ronald
Published: December 2004

The evolution of group-beneficial traits potentially allows the survival of 'cheaters' that would otherwise be unfit. Here we describe experimental work on group-beneficial traits and the consequences of frequency-dependent selection in the context of bacterial antibiotic resistance. We constructed a 'self-limited antibiotic resistant' (SLAR) strain of
Escherichia coli
in which a TEM-1 ß-lactamase was anchored to the inner membrane. In pairwise competition experiments between the SLAR strain and ampicillin-sensitive strains, only the SLAR strain survived in the presence of ampicillin. We also constructed a 'shared antibiotic resistant' (SAR) strain in which TEM-1 ß-lactamase protected both the SAR strain and nearby sensitive cells, thus acting as a model for a genetically defined group-beneficial trait. In pairwise competition experiments of the SAR strain against two different sensitive strains of
E. coli
, we found that the sensitive strains maintained themselves at frequencies of 5-12% in the presence of ampicillin. When the relative cost of the SAR strain was lowered, its equilibrial frequency rose. Sensitive strains also arose from pure cultures of the SAR strain. In these cases, too, the sensitive 'cheaters' were maintained in ampicillin at frequencies comparable to those observed in the previous competitions. These results suggest that traits which benefit other group members can permit survival of genotypes that otherwise would be eliminated by natural selection, and allow the maintenance of greater genetic variation upon which evolution can operate.
Why do multiple traits determine mating success? Differential use in female choice and male competition in a water boatman
Authors: Candolin Ulrika
Published: December 2004

Mating success is often determined by multiple traits, but why this occurs is largely unknown. Much attention has been paid to female preferences for multiple traits, but surprisingly few researchers have addressed the possibility that multiple traits are important because they serve different functions in female choice and male-male competition. Differential trait function could result from a conflict of interest between the sexes or from constraints forcing the sexes to pay attention to different traits. I show that traits determined at distinct life-history stages differ in their importance in female choice and male-male competition in a water boatman
Sigara falleni
. Juvenile conditions determined body and foreleg pala size and were the main determinants of mating success under female choice, whereas adult conditions determined body mass and influenced mating success when male competition was included. This differential use of condition-dependent traits under the two selection regimes appeared to arise partly from a conflict between the sexes, since the two selection forces (female choice and male competition) conflict for selection on pala size, and partly from constraints, as females appeared unable to assess adult condition.
The flight of macromolecular complexes in a mass spectrometer
Authors: Sobott Frank , McCammon Margaret G. , Hernández Helena , Robinson Carol V.
Published: December 2004

The discovery that conditions can be found such that non–covalent macromolecular complexes can survive the transition from solution to gas phase and remain intact during their flight in a mass spectrometer is an intriguing observation. While the nature of the interaction between the components, either ionic, hydrophobic or van der Waals, undoubtedly has an effect on the stability of these gas phase species, the role of small molecules in conferring additional stability is often overlooked. Here we review historical aspects of the development of mass spectrometry for macromolecular complexes with particular focus on the role of small molecules in stabilizing gas–phase complexes. Moreover, we demonstrate how the dissociation of small molecules from subunits within a macromolecular complex can be used to probe the topological arrangement. Overall, therefore, we show that mass spectrometry used in this way is capable of addressing features of the energy landscape not readily accessed by traditional structural biology approaches.
Multiple tautomers of cytosine identified and characterized by infrared laser spectroscopy in helium nanodroplets: probing structure using vibrational transition moment angles
Authors: Choi M. Y. , Dong F. , Miller R. E.
Published: December 2004

Infrared laser spectroscopy in helium nanodroplets is used to identify and characterize several distinct tautomers of cytosine. The experimentally observed species correspond to the lowest–energy structures obtained from
ab initio
calculations, also reported here. The assignment of the infrared vibrational bands in the spectra is aided by the measurement of the corresponding vibrational transition moment angles, which are also calculated using
ab initio
methods. In the present study we confirm the existence of three primary tautomers and provide tentative assignments for even higher–energy forms of cytosine in helium nanodroplets.
A Formal Model for Experience–Aided Diagnosis
Authors: Féret Michel P. , Glasgow Janice I.
Published: December 2004

This paper presents a novel approach to model–based diagnosis. The approach addresses the two main problems that have prevented model–based diagnostic techniques from being widely used: computational complexity of abduction and inadequacies of device models. A model for automated diagnosis is defined that combines (1) deduction to rule out hypotheses, (2) abduction to generate hypotheses, and (3) induction to recall past experiences and account for potential errors in the device models. A review of the three forms of inference is provided, as well as a detailed analysis of the relationship between case–based reasoning and induction. The proposed model for diagnosis is used to characterize diagnostic errors and relate them to different types of errors in the device models. Experimental results are then described and used to assert the practicality and the usefulness of the approach. The model presented in this paper yields a practical method for solving hard diagnostic problems at a reasonable computational cost and provides a theoretical basis for overcoming the problem of partially incorrect device models.
Efficient Processing of Queries and Assertions about Qualitative and Quantitative Temporal Constraints
Authors: Console Luca , Terenziani Paolo
Published: December 2004

A critical problem for managers of temporal information is the treatment of assertions and of complex types of queries because in many cases the treatment could involve reasoning on the whole knowledge base of temporal constraints. We propose an efficient approach to this problem. First, we show how different types of queries can be answered (in a complete way) in a time polynomial in the dimension of the query and independently of the dimension of the knowledge base. Second, we provide an efficient (and complete) procedure to deal with sessions of interleaved assertions and queries to the knowledge base. We provide both analytical and experimental evaluations of our approach, and we discuss some application areas.
Being Good at Doing Good? Quality and Accountability of Humanitarian NGOs
Authors: Hilhorst
Published: December 2004

Quality enhancement of humanitarian assistance is far from a technical task. It is interwoven with debates on politics of principles and people are intensely committed to the various outcomes these debates might have. It is a field of strongly competing truths, each with their own rationale and appeal. The last few years have seen a rapid increase in discussions, policy paper and organisational initiatives regarding the quality of humanitarian assistance. This paper takes stock of the present initiatives and of the questions raised with regard to the quality of humanitarian assistance.
Explaining the Fuel Protests
Authors: Doherty Brian , Paterson Matthew , Plows Alexandra , Wall Derek
Published: December 2004

We describe and analyse the fuel protests in the UK in September and November 2000. We draw on theories of social movements to explain the success of the first of these protests and the failure of the second. We show how the loose, network forms of organisation contributed to the success in September, and the attempts to impose more formal organisations helped to cause the failure in November. We also show how the success of the protests depended on the articulation of the aims of the protesters with dominant social forces in British politics, in particular the oil companies, the police, and the mass media.
The Origins of the Global City: Ethics and Morality in Contemporary Cosmopolitanism
Authors: Jones Deiniol
Published: December 2004

This article makes the case for a strong delineation of ethical and moral categories in contemporary international relations theory—specifically, within the theory of cosmopolitanism. The argument draws on the history of ideas, particularly observations about the nature of Stoicism in classical political thought, and a range of contemporary ‘ethical’ texts to make the case that there is a missing ethical category in contemporary approaches. Contemporary reflections on world citizenship and the global city, such as those contained in Linklater and Held, adopt a specifically moral notion of normativity and neglect an ethical component which is both distinct and theoretically practicable. The article offers a specific policy area—the area of international drug control—as a potential area of policy application.
Regionalism and Regionalisation in Britain and North America
Authors: Elcock Howard
Published: December 2004

Regionalism: the development of governments and governance structures intermediate between state and local levels has become increasingly significant in the government of both Britain and the United States. Functional issues concerned with the regeneration of rustbelt areas or controlling growth in prosperous areas have resulted in searches for regionalist solutions on both sides of the Atlantic. However, in Britain there are additional pressures from regions with distinctive cultures, as well as from the increasingly influential ‘Europe of the Regions’. Demands for regional government and governance may be generated from the bottom up by a region's politicians, business leaders and others but they are unlikely to be successful unless they are encouraged by higher levels of government, at state, national or supranational levels.
Welfare Consequences of Tight Price‐Cap Regulation
Authors: Cowan Simon
Published: December 2004

This paper analyses the welfare effects of price‐cap regulation of a multi‐product monopolist when the price index has fixed weights. A tight cap can result in welfare below the level associated with an unregulated monopoly. This does not occur if the weights are based on lagged quantities and the level of the cap exceeds the previous period's total cost. In a two‐period model the welfare problem is alleviated in the second period but first‐period performance can be worse if the firm is not myopic.
Towards an Economic Approach to Imperfect Meritocracy
Authors: Drakopoulos S. A. , Karayiannis A. D.
Published: December 2004

In this paper imperfect meritocracy is defined as the appointment in the public sector of unsuitable (in the sense of merit) individuals for political reasons. After discussing the possible causes for the emergence of an imperfect meritocracy framework, the paper then sets the basis for an economic analysis of typical politicians’ behaviour in such a framework. After deriving the demand for political appointments, the analysis verifies the intuitive insight that the number of political appointments falls when politicians are competent. Another main result is that the more votes an appointment carries through relatives and friends, the greater the demand for political appointments. Finally, it is shown that the demand for political appointments increases when taxation and the price index increase and that it falls when income increases.
Multi‐Output Capacity Measures and Their Relevance for Productivity
Authors: FÃÂÃÂÃÂÃÂÃÂÃÂÃÂÃÂre Rolf , Grosskopf Shawna , Kirkley* Jim
Published: December 2004

In this paper, measures of capacity are developed following those suggested in 1968 by Leif Johansen. By taking advantage of Shephard’s duality, both primal and dual multi‐output measures of capacity can be derived. Having generalized the capacity utilization measures, the authors show how these may be entered into measures of productivity. In particular, it is shown how the Malmquist direct and indirect productivity measures are related to various measures of capacity utilization.
Sequential Generalized Lorenz Dominance and Transfer Principles*
Authors: Ebert Udo
Published: December 2004

In an important contribution in 1987, Atkinson and Bourguignon proposed dominance criteria which allow us to compare income distributions for heterogeneous populations. They are defined by the unanimous preference of the dominating distribution by a set of welfare functions which satisfy some conditions on the derivatives of utility‐of‐income functions. This paper contributes to an understanding of some of the orderings considered. In particular it provides a characterization of the sequential generalized Lorenz ordering by transfer principles. The axiomatization illuminates the criterion.
Growth Regressions and What the Textbooks Don’t Tell You
Authors: Temple Jonathan
Published: December 2004

The paper discusses three econometric problems that are rarely given adequate discussion in textbooks: model uncertainty, parameter heterogeneity, and outliers. Leamer’s extreme bounds analysis can be adapted to address all three problems simultaneously. Two examples are presented based on an influential cross‐country growth paper by Levine and Renelt (American Economic Review, vol. 82, 1992, pp. 942‐63).
A Knowledge–based Algorithm for the Internet Transmission Control Protocol (TCP)
Authors: Stulp Freek , Verbrugge Rineke
Published: December 2004

Using a knowledge–based approach, the authors derive a protocol for the sequence transmission problem, which provides a high–level model of the Internet transmission control protocol (TCP). The knowledge–based protocol is correct for communication media where deletion and reordering errors may occur. Furthermore, it is shown that both sender and receiver eventually attain depth–n knowledge about the values of the messages for any n, but that common knowledge about the messages is not attainable.
The Endowment Effect and the Role of Uncertainty
Authors: Inder Brett , O'Brien Terry
Published: December 2004

This paper explains the endowment effect, whereby sellers generally demand considerably more for a good than buyers are prepared to pay, and related anomalies. Many decisions, including nominating buying or selling prices, involve uncertainty, and we assert that people experience negative psychological reactions to uncertainty. These reactions can affect a person's valuation of the various options, biasing the person's actions towards the status quo, thus producing the endowment effect. Our model also proposes positive or negative reactions to unlikely prospects, which are able to explain commonly observed behaviour in the presence of ambiguity.
What Does it Mean to be Market‐Driven?
Authors: Day George S.
Published: December 2004

Searching behind the slogans, and with a wealth of reference to real‐life corporate experience, this article starts by outlining some of the traps which managers can fall into in their search for market orientation. It then identifies specific capabilities and behaviours which go towards making a firm market‐driven in practice and concludes with an analysis of how the parts fit together to generate extra effectiveness.
Stockton Lecture
Authors: Bygrave Bill
Published: December 2004

In the second of the 1998 Stockton Lectures, Professor Bygrave argues that the secret of US economic success has been and continues to be its innovative and entrepreneurial culture. He identifies the industries, companies and individuals which most typify entrepreneurial innovation in the US and discusses the reasons why they succeeded. He concludes with a case history of Massachusetts, the cradle of the US industrial revolution more than a hundred years ago and still at the leading edge of US competitive advantage.
Virtual Reality and Innovation Potential
Authors: Watts Tim , Swann G.M. , Pandit Naresh R.
Published: December 2004

This article examines how companies can harness virtual reality (VR) technology to help make themselves more innovative. VR has some unique characteristics which, taken together, can help companies to develop three features common to many innovative organisations: a capacity to experiment in depth; involvement of all in the innovation process; and an ability to capture ideas generated in the innovation process. However, some obstacles need to be overcome before VR fulfils this potential.
Parsing Items into Separate Categories: Developmental Change in Infant Categorization
Authors: Younger Barbara A. , Fearing Dru D.
Published: December 2004

Three experiments report developmental change in infants' tendency to parse exemplars into separate categories. In Experiment 1, a familiarization‐novelty preference procedure was used. Fifty‐four 4‐, 7‐, and 10‐month‐old infants were familiarized with members of two basic‐level animal categories (cats and horses) and tested with novel members of the familiarized categories and with members of a third category (dogs). In Experiment 2, a habituation‐dishabituation procedure was used. Forty‐eight 7‐ and 10‐month‐old infants were habituated to examples of both male and female faces and tested with novel gender‐typical and gender‐ambiguous faces. In both experiments, 10‐month‐old infants appeared to form differentiated categories, whereas younger infants formed a single category to include the range of items presented during familiarization. Experiment 3 ruled out a priori stimulus preferences as an explanation for the 10‐month findings in Experiment 2.
A Nonverbal False Belief Task: The Performance of Children and Great Apes
Authors: Call Josep , Tomasello Michael
Published: December 2004

A nonverbal task of false belief understanding was given to 4‐ and 5‐year‐old children (N = 28) and to two species of great ape: chimpanzees and orangutans (N = 7). The task was embedded in a series of finding games in which an adult (the hider) hid a reward in one of two identical containers, and another adult (the communicator) observed the hiding process and attempted to help the participant by placing a marker on the container that she believed to hold the reward. An initial series of control trials ensured that participants were able to use the marker to locate the reward, follow the reward in both visible and invisible displacements, and ignore the marker when they knew it to be incorrect. In the crucial false belief trials, the communicator watched the hiding process and then left the area, at which time the hider switched the locations of the containers. When the communicator returned, she marked the container at the location where she had seen the reward hidden, which was incorrect. The hider then gave the subject the opportunity to find the sticker. Successful performance required participants to reason as follows: the communicator placed the marker where she saw the reward hidden; the container that was at that location is now at the other location; so the reward is at the other location. Children were also given a verbal false belief task in the context of this same hiding game. The two main results of the study were: (1) children's performance on the verbal and nonverbal false belief tasks were highly correlated (and both fit very closely with age norms from previous studies), and (2) no ape succeeded in the nonverbal false belief task even though they succeeded in all of the control trials indicating mastery of the general task demands.
Developmental and Individual Differences in Children's On‐Line Representations of Dynamic Social Events
Authors: Milch‐Reich Shoulamit , Campbell Susan B. , Pelham, Jr. William E. , Connelly Lynda M. , Geva Diklah
Published: December 2004

Developmental and clinical differences in children's on‐line understanding of ongoing social events were examined. Boys with (n = 38) and without (n = 41) Attention Deficit Hyperactivity Disorder (ADHD) were compared. Prior social schemes and integrative processes were hypothesized to influence children's representation of incoming social cues. Younger children and children with ADHD were expected to differ from older children and children without ADHD, respectively, in what they encoded and how they organized the encoded information. Differences in on‐line representation were postulated to underlie differences in children's recall and social reasoning. Children's prior social schemes, looking time and on‐line verbal protocols, recall, and social reasoning were assessed. Younger boys and ADHD boys showed less integrated on‐line representations, accounting for poorer recall and reasoning.
Developmental Trajectories of Disruptive Behavior Problems in Preschool Children of Adolescent Mothers
Authors: Spieker Susan J. , Larson Nancy C. , Lewis Steven M. , Keller Thomas E. , Gilchrist Lewayne
Published: December 2004

Using hierarchical linear modeling (HLM), we analyzed individual developmental trajectories of disruptive behavior problems between ages 3.5 to 6.0 years for 183 children of adolescent mothers. We examined how the level of problem behavior (intercept) and the rate of change over time (slope) are influenced by child's sex, mother's depression/anxiety symptoms, and mother's use of negative control for regulating child behavior. On average, disruptive behavior decreased from age 3.5 to 6.0. Child sex and maternal depression/anxiety related to the level of behavior problems but not to the rate of change. Boys and children of more depressed/anxious mothers exhibited higher levels of disruptive behavior. Maternal negative control was associated with both level of disruptive behavior and rate of change, and negative control mediated the effects of maternal depression/anxiety. Greater negative control corresponded to higher levels of behavior problems and no reduction in their display over time. Child race moderated effects of negative control.
Temporal Contingency as an Independent Component of Parenting Behavior
Authors: Keller Heidi , Lohaus Arnold , Völker Susanne , Cappenberg Martina , Chasiotis Athanasios
Published: December 2004

Several theoretical conceptions emphasize the importance of prompt responses to infant's signals in providing them with early causal experiences. The present paper examines if a maternal tendency toward prompt responses can be identified by distributional analyses of maternal response latencies and if this response tendency can be shown for different communicative channels (in verbal/vocal, nonverbal, intermodal communication). In addition, the paper focuses on the relation between the temporal contingency of maternal behavior and measures of maternal interactional quality. Interactional sequences of 54 mother and 3‐month‐old infant dyads were analyzed using microanalytical assessment techniques and ratings of interactional quality. Distributional analyses of maternal expressions during face‐to‐face encounters revealed that promptness of responses toward infant signals with a short latency is a typical response tendency in maternal behavior. There are, however, individual differences between mothers, indicating that this response tendency is expressed in different communicative channels by individual mothers. This is shown by low correlations between the contingency indices of different communicative channels. The relation between contingency and rated indicators of interactional quality turned out to be rather small, indicating that maternal contingency may be conceptualized to contribute an independent factor to the quality of maternal interactional behavior.
Children's Evaluations of Decision‐Making Procedures in Peer, Family, and School Contexts
Authors: Helwig Charles C. , Kim Susan
Published: December 2004

Children's evaluations of decision‐making procedures were examined in applications in different social contexts. Seventy‐two children evenly divided into three grade levels (grades 1 – 2, 3 – 4, 5 – 6) were administered a structured interview requiring them to evaluate three decision‐making procedures (consensus, majority rule, and authority‐based) embedded in three social contexts (peer group, family, and school classroom) and to select the most appropriate decision‐making procedure for two specific decisions: one expected to pull for procedures emphasizing children's autonomous decision making, and one expected to pull for adult authority. Judgments of decision‐making procedures at all grade levels did not show a heteronomous acceptance of adult authority but rather were influenced by social context and type of decision. In general, consensus was preferred in peer and family contexts and authority‐based procedures were preferred for school decisions about curriculum. Older children were more likely than younger children to consider how children's limited knowledge and competence may constrain their autonomous decision making.
Parental Reactions to Children's Negative Emotions: Longitudinal Relations to Quality of Children's Social Functioning
Authors: Eisenberg Nancy , Fabes Richard A. , Shepard Stephanie A. , Guthrie Ivanna K. , Murphy Bridget C. , Reiser Mark
Published: December 2004

Relations between self‐reported parental reactions to children's negative emotions (PNRs) and children's socially appropriate/problem behavior and negative emotionality were examined longitudinally. Evidence was consistent with the conclusion that relations between children's externalizing (but not internalizing) emotion and parental punitive reactions to children's negative emotions are bidirectional. Reports of PNRs generally were correlated with low quality of social functioning. In structural models, mother‐reported problem behavior at ages 10 – 12 was at least marginally predicted from mother‐reported problem behavior, children's regulation, and parental punitive or distress reactions. Moreover, parental distress and punitive reactions at ages 6 – 8 predicted reports of children's regulation at ages 8 – 10, and regulation predicted parental punitive reactions at ages 10 – 12. Father reports of problem behavior at ages 10 – 12 were predicted by earlier problem behavior and parental distress or punitive reactions; some of the relations between regulation and parental reactions were similar to those in the models for mother‐reported problem behavior. Parental perceptions of their reactions were substantially correlated over 6 years. Some nonsupportive reactions declined in the early to mid‐school years, but all increased into late childhood/early adolescence.
From Individual Differences to Dynamic Pathways of Development
Authors: Fischer Kurt W. , Paré‐Blagoev Juliana
Published: December 2004

A fruitful way to build upon French‐language research on development of analogical and propositional processes in logical reasoning tasks is to use dynamic systems tools to describe and analyze relevant developmental pathways. Issues to address include (1) the characteristics of developmental transitions, such as hysteresis; (2) the nature of growth processes, such as hierarchical development or predator–prey interactions; and (3) the construction of effective scales for measuring change in logical reasoning.