bluuebunny/crossref_metadata_2025 huggingface dataset:
LONG RANGE DEPENDENCE, NO ARBITRAGE AND THE BLACK–SCHOLES FORMULA
Authors: ZÄHLE M.
Published: July 2002

A bond and stock model is considered where the driving process is the sum of a Wiener process W and a continuous process Z with zero generalized quadratic variation. By means of forward integrals a hedge against Markov-type claims is constructed. If Z is independent of W under some natural assumptions on Z and the admissible portfolio processes the model is shown to be arbitrage free. The fair price of the above claims agrees with that in the classical case Z ≡ 0. In particular, the Black–Scholes formula remains valid for non-semimartingale models with long range dependence.
A CONSTRUCTIVE EXTENSION OF ARTSTEIN'S THEOREM TO THE STOCHASTIC CONTEXT
Authors: DAUMAIL LAURENT , FLORCHINGER PATRICK
Published: July 2002

The aim of this paper is to extend Artstein's theorem on the stabilization of affine in the control nonlinear deterministic systems to nonlinear stochastic differential systems when both the drift and the diffusion terms are affine in the control. We prove that the existence of a smooth control Lyapunov function implies smooth stabilizability.
INERTIAL PARTICLES IN A RANDOM FIELD
Authors: SIGURGEIRSSON H. , STUART A. M.
Published: July 2002

The motion of an inertial particle in a Gaussian random field is studied. This is a model for the phenomenon of preferential concentration, whereby inertial particles in a turbulent flow can correlate significantly. Mathematically the motion is described by Newton's second law for a particle on a 2-D torus, with force proportional to the difference between a background fluid velocity and the particle velocity itself. The fluid velocity is defined through a linear stochastic PDE of Ornstein–Uhlenbeck type. The properties of the model are studied in terms of the covariance of the noise which drives the stochastic PDE.

Sufficient conditions are found for almost sure existence and uniqueness of particle paths, and for a random dynamical system with a global random attractor. The random attractor is illustrated by means of a numerical experiment, and the relevance of the random attractor for the understanding of particle distributions is highlighted.
ADOPTION RATES AND PATTERNS OF BEST PRACTICES IN NEW PRODUCT DEVELOPMENT
Authors: DOOLEY KEVIN J. , SUBRA ANAND , ANDERSON JOHN
Published: July 2002

Firms are experimenting with numerous different best practices in order to improve the timeliness and effectiveness of their new product development (NPD) process. This paper examines how widely adopted certain best practices are, and if the adoptions show any pattern in terms of being simultaneously adopted within organisations. We developed an inventory of best practices related to NPD, and an empirical survey was administered to 39 companies. Our results indicate that best practices associated with enhancing the human resources involved in NPD, and improving the fuzzy front end of NPD appear to be getting little attention to date, despite a strong call for such attention in the management literature. Best practices associated with the strategic implementation of NPD (project selection, goals, technological leadership, product strategy, and customer involvement) are on average all more widely adopted than best practices associated with controlling the execution of NPD (process control, metrics, documentation, change control).
Searching for the holy grail of software engineering
Authors: Glass Robert L.
Published: July 2002

`But my project is different' really is a valid response.
The organism and the mechanism of projects
Authors: Armour Phillip G.
Published: July 2002

Software developers would do well to place more emphasis on the social and communication traits of team members.
Theory of keyblock-based image retrieval
Authors: Zhu Lei , Rao Al Bing , Zhang Aldong
Published: July 2002

The success of text-based retrieval motivates us to investigate analogous techniques which can support the querying and browsing of image data. However, images differ significantly from text both syntactically and semantically in their mode of representing and expressing information. Thus, the generalization of information retrieval from the text domain to the image domain is non-trivial. This paper presents a framework for information retrieval in the image domain which supports content-based querying and browsing of images. A critical first step to establishing such a framework is to construct a codebook of "keywords" for images which is analogous to the dictionary for text documents. We refer to such "keywords" in the image domain as "keyblocks." In this paper, we first present various approaches to generating a codebook containing keyblocks at different resolutions. Then we present a keyblock-based approach to content-based image retrieval. In this approach, each image is encoded as a set of one-dimensional index codes linked to the keyblocks in the codebook, analogous to considering a text document as a linear list of keywords. Generalizing upon text-based information retrieval methods, we then offer various techniques for image-based information retrieval. By comparing the performance of this approach with conventional techniques using color and texture features, we demonstrate the effectiveness of the keyblock-based approach to content-based image retrieval.
Atomicity and isolation for transactional processes
Authors: Schuldt Heiko , Alonso Gustavo , Beeri Catriel , Schek Hans-Jörg
Published: July 2002

Processes are increasingly being used to make complex application logic explicit. Programming using processes has significant advantages but it poses a difficult problem from the system point of view in that the interactions between processes cannot be controlled using conventional techniques. In terms of recovery, the steps of a process are different from operations within a transaction. Each one has its own termination semantics and there are dependencies among the different steps. Regarding concurrency control, the flow of control of a process is more complex than in a flat transaction. A process may, for example, partially roll back its execution or may follow one of several alternatives. In this article, we deal with the problem of atomicity and isolation in the context of processes. We propose a unified model for concurrency control and recovery for processes and show how this model can be implemented in practice, thereby providing a complete framework for developing middleware applications using processes.
A survey of methods for recovering quadrics in triangle meshes
Authors: Petitjean Sylvain
Published: July 2002

In a variety of practical situations such as reverse engineering of boundary representation from depth maps of scanned objects, range data analysis, model-based recognition and algebraic surface design, there is a need to recover the shape of visible surfaces of a dense 3D point set. In particular, it is desirable to identify and fit simple surfaces of known type wherever these are in reasonable agreement with the data. We are interested in the class of quadric surfaces, that is, algebraic surfaces of degree 2, instances of which are the sphere, the cylinder and the cone. A comprehensive survey of the recent work in each subtask pertaining to the extraction of quadric surfaces from triangulations is presented.
Pareto-optimal formulations for cost versus colorimetric accuracy trade-offs in printer color management
Authors: Littlewood D. J. , Drakopoulos P. A. , Subbarayan G.
Published: July 2002

Color management for the printing of digital images is a challenging task, due primarily to nonlinear ink-mixing behavior and the presence of redundant solutions for print devices with more than three inks. Algorithms for the conversion of image data to printer-specific format are typically designed to achieve a single predetermined rendering intent, such as colorimetric accuracy. In the present paper we present two CIELAB to CMYK color conversion schemes based on a general Pareto-optimal formulation for printer color management. The schemes operate using a 149-color characterization data set selected to efficiently capture the entire CMYK gamut. The first scheme uses artificial neural networks as transfer functions between the CIELAB and CMYK spaces. The second scheme is based on a reformulation of tetrahedral interpolation as an optimization problem. Characterization data are divided into tetrahedra for the interpolation-based approach using the program Qhull, which removes the common restriction that characterization data be well organized. Both schemes offer user control over trade-off problems such as cost versus reproduction accuracy, allowing for user-specified print objectives and the use of constraints such as maximum allowable ink and maximum allowable ΔE*ab. A formulation for minimization of ink is shown to be particularly favorable, integrating both clipping and gamut compression features into a single methodology. Codes developed as applications of these schemes were used to convert several CIELAB Tiff images to CMYK format, providing both qualitative and quantitative verification of the Pareto-optimal approach. Prints of the MacBeth ColorCheckertmchart were accurate within approximately to 3 ΔE*abfor in-gamut colors. Modifications to this approach are presented that offer user control over grey component replacement and provide additional options for rendering intent.
Random number generation with primitive pentanomials
Authors: Wu Pei-Chi
Published: July 2002

This paper presents generalized feedback shift register (GFSR) generators with primitive polynomials
x

p

+
x

p
-1

+
x

q

+
x

q
-1

+ 1. The recurrence of these generators can be efficiently computed. We adopt Fushimi's initialization scheme, which guarantees the
k
-distribution property. Statistical and timing results are presented.
A methodology for certification of modeling and simulation applications
Authors: Balci Osman
Published: July 2002

Certification of modeling and simulation (M&S) applications poses significant technical challenges for M&S program managers, engineers, and practitioners. Certification is becoming increasingly more important as M&S applications are used more and more for military training, complex system design evaluation, M&S-based acquisition, problem solving, and critical decision making. Certification, a very complex process, involves the measurement and evaluation of hundreds of qualitative and quantitative elements, mandates subject matter expert evaluation, and requires the integration of different evaluations. Planning and managing such measurements and evaluations requires a unifying methodology and should not be performed in an
ad hoc
manner. This paper presents such a methodology. The methodology consists of the following body of methods, rules, and postulates: (a) employment of subject matter experts, (b) construction of a hierarchy of indicators, (c) relative criticality weighting of indicators using the analytic hierarchy process, (d) using a rule-based expert knowledge base with an object-oriented specification language, (e) assignment of crisp, fuzzy, and nominal scores for the indicators, (f) aggregation of indicator scores, (g) graphical representation of the indicator scores and weights, (h) hypertext certification report, and (i) interpretation of the results. The methodology can be used for certification of any kind of M&S application either throughout the M&S development life cycle or after the development is completed.
Improving education and training with IT
Authors: Benbunan-Fich Raquel
Published: July 2002

Findings from the review of previous empirical studies set the foundation for a conceptual model demonstrating how IT supports learning and group communications.
Global networking for everyone
Authors: Gerwig Kate
Published: July 2002

Maybe would-be global telecommunications providers need a theme song, if not a team song. Disney's "It's a Small World after All" may be just the one. But if providers can't or won't sing, maybe they could try chanting it, along with their multinational corporation (MNC) customers.
Estimation of blocking probabilities in cellular networks with dynamic channel assignment
Authors: Vázquez-abad Felisa J. , Andrew Lachlan L. H. , Everitt David
Published: July 2002

Blocking probabilities in cellular mobile communication networks using dynamic channel assignment are hard to compute for realistic sized systems. This computational difficulty is due to the structure of the state space, which imposes strong coupling constraints amongst components of the occupancy vector. Approximate tractable models have been proposed, which have product form stationary state distributions. However, for real channel assignment schemes, the product form is a poor approximation and it is necessary to simulate the actual occupancy process in order to estimate the blocking probabilities.Meaningful estimates of the blocking probability typically require an enormous amount of CPU time for simulation, since blocking events are usually rare. Advanced simulation approaches use importance sampling (IS) to overcome this problem. In this article, we study two regimes under which blocking is a rare event: low-load and high cell capacity. Our simulations use the standard clock (SC) method. For low load, we propose a change of measure that we call
static ISSC
, which has bounded relative error. For high capacity, we use a change of measure that depends on the current state of the network occupancy. This is the
dynamic ISSC
method. We prove that this method yields zero variance estimators for single clique models, and we empirically show the advantages of this method over naïve simulation for networks of moderate size and traffic loads.
Growing applications of linear programming
Authors: Aronofsky J. S.
Published: July 2002

Use of linear programming models has grown so extensively in recent years that the whole concept for organizing a computer code has undergone a radical change. It no longer is adequate merely to reduce a mathematical algorithm (i.e. the simplex method) to a computer code. An advanced code must cope with such a variety of situations that the respective computer subprograms must be organized into an integrated system.Emphasis in this paper is devoted to the underlying principles upon which future linear programming systems must be based. These viewpoints are influenced by the new demands that applications within the petroleum industry are placing on such systems. Some of the components of such a system are: translation of problem statement in terms of basic data to linear programming matrix coefficients, data transmission for direct computer entry, data file at the computer center, data processing and editing prior to solving the simplex algorithm, an efficient and reliable code for solving the above-mentioned algorithm, and flexible means for summarizing the results.
xlinkit
Authors: Nentwich Christian , Capra Licia , Emmerich Wolfgang , Finkelsteiin Anthony
Published: July 2002

xlinkit is a lightweight application service that provides rule-based link generation and checks the consistency of distributed Web content. It leverages standard Internet technologies, notably XML, XPath, and XLink. xlinkit can be used as part of a consistency management scheme or in applications that require smart link generation, including portal construction and management of large document repositories. In this article we show how consistency constraints can be expressed and checked. We describe a novel semantics for first-order logic that produces links instead of truth values and give an account of our content management strategy. We present the architecture of our service and the results of two substantial case studies that use xlinkit for checking course syllabus information and for validating UML models supplied by industrial partners.
E-commerce and the undulating distribution channel
Authors: Gallaugher John M.
Published: July 2002

Understanding the role of e-commerce in restructuring distribution channels by examining the factors influencing the collapse, shift, and expansion of channels.
The quality of online social relationships
Authors: Cummings Jonathon N. , Butler Brian , Kraut Robert
Published: July 2002

Online relationships are less valuable than offline ones. Indeed, their net benefit depends on whether they supplement or substitute for offline social relationships.
A post-baccalaureate undergraduate-level program in computer science
Authors: Simonson Shai
Published: July 2002

A one-year pilot education, tuition-free, that could be shared under an open-source license with the rest of the world.
Intraocular surgery on a virtual eye
Authors: Wagner Clemens , Schill Markus , Männer Reinhard
Published: July 2002

The EyeSi surgical simulation immerses the surgeon in an environment of real surgical instruments, virtual tissue deformations, and interactive 3D graphics.
SHOOT ANDFLORALMERISTEMMAINTENANCE INARABIDOPSIS
Authors: Fletcher Jennifer C.
Published: July 2002

▪ Abstract  The shoot apical meristem (SAM) of higher plants functions as a site of continuous organogenesis within which a small pool of pluripotent stem cells replenishes the cells incorporated into lateral organs. This article summarizes recent results demonstrating that the fate of stem cells in Arabidopsis shoot and floral meristems is controlled by overlapping spatial and temporal signaling systems. Stem cell maintenance is an active process requiring constant communication between neighboring groups of SAM cells. Information flows via a ligand-receptor signal transduction pathway, resulting in the formation of a spatial feedback loop that stabilizes the size of the stem cell population. Termination of stem cell activity during flower development is achieved by a temporal feedback loop involving both stem cell maintenance genes and flower patterning genes. These investigations are providing exciting insights into the components and activities of the stem cell regulatory pathway and into the interaction of this pathway with molecular mechanisms that control floral patterning.
A NEWMOSSGENETICS: Targeted Mutagenesis inPhyscomitrella patens
Authors: Schaefer Didier G.
Published: July 2002

▪ Abstract  The potential of moss as a model system to study plant biology is associated with their relatively simple developmental pattern that nevertheless resembles the basic organization of the body plan of land plants, the direct access to cell-lineage analysis, their similar responses to plant growth factors and environmental stimuli as those observed in other land plants, and the dominance of the gametophyte in the life cycle that facilitates genetic approaches. Transformation studies in the moss Physcomitrella patens have revealed a totally unique feature for plants, i.e., that foreign DNA sequences integrate in the genome preferentially at targeted locations by homologous recombination, enabling for the first time in plants the application of the powerful molecular genetic approaches used routinely in bacteria, yeast, and since 1989, the mouse embryonic stem cells. This article reviews our current knowledge of Physcomitrella patens transformation and its unique suitability for functional genomic studies.
CHLORORESPIRATION
Authors: Peltier Gilles , Cournac Laurent
Published: July 2002

▪ Abstract  Chlororespiration has been defined as a respiratory electron transport chain (ETC) in interaction with the photosynthetic ETC in thylakoid membranes of chloroplasts. The existence of chlororespiration has been disputed during the last decade, with the initial evidence mainly obtained with intact algal cells being possibly explained by redox interactions between chloroplasts and mitochondria. The discovery in higher-plant chloroplasts of a plastid-encoded NAD(P)H-dehydrogenase (Ndh) complex, homologous to the bacterial complex I, and of a nuclear-encoded plastid terminal oxidase (PTOX), homologous to the plant mitochondrial alternative oxidase, brought molecular support to the concept of chlororespiration. The functionality of these proteins in nonphotochemical reduction and oxidation of plastoquinones (PQs), respectively, has recently been demonstrated. In thylakoids of mature chloroplasts, chlororespiration appears to be a relatively minor pathway compared to linear photosynthetic electron flow from H2O to NADP+. However, chlororespiration might play a role in the regulation of photosynthesis by modulating the activity of cyclic electron flow around photosystem I (PS I). In nonphotosynthetic plastids, chlororespiratory electron carriers are more abundant and may play a significant bioenergetic role.
VASCULAR TISSUE DIFFERENTIATION AND PATTERN FORMATION IN PLANTS
Authors: Ye Zheng-Hua
Published: July 2002

▪ Abstract  Vascular tissues, xylem and phloem, are differentiated from meristematic cells, procambium, and vascular cambium. Auxin and cytokinin have been considered essential for vascular tissue differentiation; this is supported by recent molecular and genetic analyses. Xylogenesis has long been used as a model for study of cell differentiation, and many genes involved in late stages of tracheary element formation have been characterized. A number of mutants affecting vascular differentiation and pattern formation have been isolated in Arabidopsis. Studies of some of these mutants have suggested that vascular tissue organization within the bundles and vascular pattern formation at the organ level are regulated by positional information.
Computational Cell Biology: Spatiotemporal Simulation of Cellular Events
Authors: Slepchenko Boris M. , Schaff James C. , Carson John H. , Loew Leslie M.
Published: July 2002

▪ Abstract  The field of computational cell biology has emerged within the past 5 years because of the need to apply disciplined computational approaches to build and test complex hypotheses on the interacting structural, physical, and chemical features that underlie intracellular processes. To meet this need, newly developed software tools allow cell biologists and biophysicists to build models and generate simulations from them. The construction of general-purpose computational approaches is especially challenging if the spatial complexity of cellular systems is to be explicitly treated. This review surveys some of the existing efforts in this field with special emphasis on a system being developed in the authors' laboratory, Virtual Cell. The theories behind both stochastic and deterministic simulations are discussed. Examples of respective applications to cell biological problems in RNA trafficking and neuronal calcium dynamics are provided to illustrate these ideas.
Computational Mechanics
Authors: Schmauder Siegfried
Published: July 2002

▪ Abstract  Computational mechanics comprises all types of computer modeling of the mechanical behavior of materials. In this contribution we concentrate on new developments in modeling based on the finite element method (FEM), especially deformation analyses based on numerical homogenization techniques (self-consistent embedding procedure, matricity model), simulations of real microstructural cut-outs, damage analyses of artificial and real microstructures, and multiscale modeling aspects. The limit flow stresses for transverse loading of metal matrix composites reinforced with continuous fibers and for uniaxial loading of spherical particle reinforced metal matrix composites are investigated by recently developed embedded cell models in conjunction with the finite element method. A fiber of circular cross section or a spherical particle is surrounded by a metal matrix, which is again embedded in the composite material, with the mechanical behavior to be determined iteratively in a self-consistent manner. Stress-strain curves have been calculated for a number of metal matrix composites with the embedded cell method and verified with literature data of a particle reinforced Ag/58vol.%Ni composite and for a transversely loaded uniaxially fiber reinforced Al/46vol.%B composite. Good agreement has been obtained between experiment and calculation, and the embedded cell model is thus found to well represent metal matrix composites with randomly arranged inclusions. Systematic studies of the mechanical behavior of fiber- and particle-reinforced composites with plane strain and axisymmetric embedded cell models are carried out to determine the influence of fiber or particle volume fraction and matrix strain-hardening ability on composite strengthening levels. Results for random inclusion arrangements obtained with self-consistent embedded cell models are compared with strengthening levels for regular inclusion arrangements from conventional unit cell models. It is found that with increasing inclusion volume fractions pronounced differences in composite strengthening exist between all models. Finally, closed-form expressions are derived to predict composite strengthening for regular fiber arrangements and for realistic random fiber or particle arrangements as a function of matrix hardening and particle volume fraction. The impact of the results on effectively designing technically relevant metal matrix composites reinforced by randomly arranged strong inclusions is emphasized. Atomistic modeling such as Monte Carlo (MC) simulations and molecular dynamics (MD) methods, dislocation theoretical modeling, and continuum mechanical methods are applied in order to provide insight into the mechanical behavior of materials. Simulations are presented graphically in a systematic manner for different material systems and are compared with experimental results. Finally, it will be shown that the results can be used to predict the future behavior of materials presently in service and even to design new materials.
Mechanical and Electrical Properties of Nanotubes
Authors: Bernholc J. , Brenner D. , Buongiorno Nardelli M. , Meunier V. , Roland C.
Published: July 2002

▪ Abstract  We review the recent progress in our understanding of the mechanical and electrical properties of carbon nanotubes, emphasizing the theoretical aspects. Nanotubes are the strongest materials known, but the ultimate limits of their strength have yet to be reached experimentally. Modeling of nanotube-reinforced composites indicates that the addition of small numbers of nanotubes may lead to a dramatic increase in the modulus, with only minimal crosslinking. Deformations in nanotube structures lead to novel structural transformations, some of which have clear electrical signatures that can be utilized in nanoscale sensors and devices. Chemical reactivity of nanotube walls is facilitated by strain, which can be used in processing and functionalization. Scanning tunneling microscopy and spectroscopy have provided a wealth of information about the structure and electronic properties of nanotubes, especially when coupled with appropriate theoretical models. Nanotubes are exceptional ballistic conductors, which can be used in a variety of nanodevices that can operate at room temperature. The quantum transport through nanotube structures is reviewed at some depth, and the critical roles played by band structure, one-dimensional confinement, and coupling to nanoscale contacts are emphasized. Because disorder or point defect–induced scattering is effectively averaged over the circumference of the nanotube, electrons can propagate ballistically over hundreds of nanometers. However, severe deformations or highly resistive contacts isolate nanotube segments and lead to the formation of quantum dots, which exhibit Coulomb blockade effects, even at room temperature. Metal-nanotube and nanotube-nanotube contacts range from highly transmissive to very resistive, depending on the symmetry of two structures, the charge transfer, and the detailed rehybridization of the wave functions. The progress in terms of nanotube applications has been extraordinarily rapid, as evidenced by the development of several nanotube-based prototypical devices, including memory and logic circuits, chemical sensors, electron emitters and electromechanical actuators.
The Role of Hypocretins (Orexins) in Sleep Regulation and Narcolepsy
Authors: Taheri Shahrad , Zeitzer Jamie M. , Mignot Emmanuel
Published: July 2002

▪ Abstract  The hypocretins (orexins) are two novel neuropeptides (Hcrt-1 and Hcrt-2), derived from the same precursor gene, that are synthesized by neurons located exclusively in the lateral, posterior, and perifornical hypothalamus. Hypocretin-containing neurons have widespread projections throughout the CNS with particularly dense excitatory projections to monoaminergic centers such as the noradrenergic locus coeruleus, histaminergic tuberomammillary nucleus, serotoninergic raphe nucleus, and dopaminergic ventral tegmental area. The hypocretins were originally believed to be primarily important in the regulation of appetite; however, a major function emerging from research on these neuropeptides is the regulation of sleep and wakefulness. Deficiency in hypocretin neurotransmission results in the sleep disorder narcolepsy in mice, dogs, and humans. The hypocretins are also uniquely positioned to link sleep, appetite, and neuroendocrine control. The aim of this review is to describe and discuss the current knowledge regarding the hypocretin neurotransmitter system in narcolepsy and normal sleep.
Intentional Maps in Posterior Parietal Cortex
Authors: Andersen Richard A. , Buneo Christopher A.
Published: July 2002

▪ Abstract  The posterior parietal cortex (PPC), historically believed to be a sensory structure, is now viewed as an area important for sensory-motor integration. Among its functions is the forming of intentions, that is, high-level cognitive plans for movement. There is a map of intentions within the PPC, with different subregions dedicated to the planning of eye movements, reaching movements, and grasping movements. These areas appear to be specialized for the multisensory integration and coordinate transformations required to convert sensory input to motor output. In several subregions of the PPC, these operations are facilitated by the use of a common distributed space representation that is independent of both sensory input and motor output. Attention and learning effects are also evident in the PPC. However, these effects may be general to cortex and operate in the PPC in the context of sensory-motor transformations.
AB INITIO MOLECULAR DYNAMICS WITH DENSITY FUNCTIONAL THEORY
Authors: Tse John S.
Published: July 2002

▪ Abstract  Recent applications of density functional theory base ab initio molecular dynamics in chemical relevant systems are reviewed. The emphasis is on the dynamical aspect in the study of structures, reaction mechanisms, and electronic properties in both the molecular and condensed phases. Examples were chosen from fluxional molecules, solution reactions, and biological systems to illustrate the broad potential applications and unique information that can be obtained from ab initio molecular dynamics calculations. Recent advances in the development of efficient numerical algorithms for the prediction of spectroscopic properties are highlighted.
The Changing Face of Methodological Individualism
Authors: Udehn Lars
Published: July 2002

▪ Abstract  It is common to categorize social scientific theories as either individualistic or holistic, and to assume that they are opposites. This neat picture is not so much wrong as too simple. There are different versions of both doctrines, and some versions combine elements from both. In this article I distinguish a number of versions of methodological individualism that differ significantly in strength. The main divide is between strong versions of methodological individualism, which suggest that all social phenomena should be explained only in terms of individuals and their interaction, and weak versions of methodological individualism, which also assign an important role to social institutions and/or social structure in social science explanations.
All‐Solid‐State Lithium Thin‐Film Rechargeable Battery with Lithium Manganese Oxide
Authors: Park Young‐Shin , Lee Se‐Hee , Lee Byung‐Il , Joo Seung‐Ki
Published: July 2002

All‐solid‐state rechargeable thin‐film batteries were fabricated with the cell structure of

Li
/
Lipon
/

LiMn

2

O

4

using sequential thin‐ film deposition techniques. Room‐temperature cycling of these cells showed a nearly constant potential of

4.0
V

, good coulombic efficiency, and the capability of carrying high current density. Planar microbatteries were connected in series through metallization. High voltages of approximately

32
V

could be realized by serial connection of eight unit cells. ©1999 The Electrochemical Society
Thermodynamic Properties for Rare Earths and Americium in Pyropartitioning Process Solvents
Authors: Fusselman S. P. , Roy J. J. , Grimmett D. L. , Grantham L. F. , Krueger C. L. , Nabelek C. R. , Storvick T. S. , Inoue Tadashi , Hijikata Takatoshi , Kinoshita Kensuke , Sakamura Yoshiharu , Uozumi Koichi , Kawai Tsutomu , Takahashi Noriaki
Published: July 2002

The design of a molten metal‐molten salt based chemical and electrochemical process for separation of actinides from plutonium‐uranium extraction waste requires a consistent set of thermodynamic properties for the actinides and rare earths present in nuclear waste. Standard potential data for Y, La, Ce, Pr, and Gd in molten LiCl‐KCl were obtained. Americium data obtained were standard potentials in molten LiCl‐KCl and activity coefficients for Cd and Bi. Data were obtained between 400 and 500°C. Results for the rare earth chlorides using an improved experimental technique were consistent with theory, with standard free energy of formation values somewhat more negative than those found in the literature. Special attention was given to Am in the LiCl‐KCl/Cd system because it can exist as the +2 and/or +3 ion in this system. Americium ions existed only as the +3 ion in LiCl‐KCl/Bi. Standard electrochemical potentials for

Am
/

Am

+
2

in LiCl‐KCl eutectic at 400, 450, and 500°C were −2.893, −2.853, and −2.838 V, respectively, relative to

Cl

2

/

Cl

−

. Standard electrochemical potentials vs.

Cl

2

/

Cl

−

for

Am
/

Am

+
3

in LiCl‐KCl eutectic were −2.83 V at 450°C and −2.78 V at 500°C. Activity coefficients for Am in molten Cd were

1
×

10

−
5

and

8
×

10

−
5

at 450 and 500°C. Activity coefficients for Am in molten Bi were

2
×

10

−
11

and

2
×

10

−
10

at 450 and 500°C. © 1999 The Electrochemical Society. All rights reserved.
Increased Circulating Malondialdehyde-Modified LDL Levels in Patients With Coronary Artery Diseases and Their Association With Peak Sizes of LDL Particles
Authors: Tanaga Kosei , Bujo Hideaki , Inoue Masahiro , Mikami Keiji , Kotani Kazuo , Takahashi Kazuo , Kanno Takashi , Saito Yasushi
Published: July 2002

Recent establishment of a sensitive ELISA system using antibodies against malondialdehyde-modified low density lipoprotein (MDA-LDL) made it possible to determine the circulating oxidized lipoprotein levels. Here, we investigated the serum levels of MDA-LDL in 62 patients with coronary artery disease (CAD) compared with the levels in 42 patients without CAD [groups CAD(+) and CAD(−), respectively], which are adjusted for age, serum total cholesterol, LDL and high density lipoprotein cholesterol, and triglyceride levels. Serum MDA-LDL levels were 113.4±49.1 IU/L in CAD(+), which were significantly higher than the levels in CAD(−) (85.2±22.5 IU/L,
P
<0.0005). The ratio of MDA-LDL/LDL cholesterol was 0.95±0.32 in CAD(+), indicating a significant increase compared with the ratio in CAD(−) (0.68±0.19,
P
<0.0005). The positive correlation of MDA-LDL level and the ratio of MDA-LDL/LDL cholesterol with intima-media thickness in carotid arteries was observed. Age was not clearly associated with the MDA-LDL level (
P
=0.865). The serum MDA level was positively correlated with LDL cholesterol (
P
<0.0001) and with triglycerides (
P
<0.001) and negatively correlated with high density lipoprotein cholesterol (
P
<0.05). Furthermore, the MDA-LDL level was negatively correlated with the peak size of the LDL particle (
P
<0.01). The LDL subclasses that were identified by using the sera collected from the subjects by sequential ultracentrifugation showed that the ratios of MDA-LDL/apolipoprotein B in LDL3 and LDL4 were nearly 3-fold higher than those in LDL1 and LDL2 for CAD(+) and CAD(−). These results indicate that the circulating MDA-LDL level is increased in CAD(+), independent of the serum LDL cholesterol level but in association with the peak size of LDL particles. The measurement of serum MDA-LDL level may be useful for the identification of patients with advanced atherosclerosis.
Fluvastatin Reduces Tissue Factor Expression and Macrophage Accumulation in Carotid Lesions of Cholesterol-Fed Rabbits in the Absence of Lipid Lowering
Authors: Baetta Roberta , Camera Marina , Comparato Carmen , Altana Caterina , Ezekowitz Michael D. , Tremoli Elena
Published: July 2002

The expression of tissue factor (TF), mainly by infiltrated inflammatory cells, has been shown to be responsible for the thrombogenicity associated with atheroma. The contribution of the nonlipid-related effects of statins to the clinical benefits of statin therapy is currently under intense investigation. In this study, we evaluated the ability of fluvastatin to modulate TF expression and macrophage accumulation in rabbit carotid intimal lesions independently of cholesterol lowering. Male rabbits were fed for 30 days a 1% cholesterol-rich diet with or without fluvastatin at 5 mg/kg per day. Two weeks from the start of treatment, a silastic collar was placed around the carotid artery. Fifteen days later, the animals were killed, and carotid segments were excised and processed. The atherogenic diet caused a consistent increase in plasma cholesterol levels (610±231 mg/dL versus 50±9 mg/dL at baseline), which were not affected by fluvastatin (603±248 mg/dL). In the rabbits fed a high cholesterol diet without fluvastatin, an intimal lesion with macrophage accumulation and TF expression was detected. Fluvastatin significantly reduced TF and macrophage content of the lesion (−50% for both). Results indicate that fluvastatin may attenuate the inflammatory and thrombogenic potential of atherosclerotic lesions through a mechanism(s) other than cholesterol reduction, providing new insight regarding the complex mode of action of statins.
Factor V Leiden, Hormone Replacement Therapy, and Risk of Venous Thromboembolic Events in Women With Coronary Disease
Authors: Herrington David M. , Vittinghoff Eric , Howard Timothy D. , Major David A. , Owen John , Reboussin David M. , Bowden Donald , Bittner Vera , Simon Joel A. , Grady Deborah , Hulley Stephen B.
Published: July 2002

Oral contraceptive use in women with factor V Leiden is associated with increased rates of venous thromboembolic events (VTEs). However, the effects of hormone replacement therapy (HRT) in postmenopausal women with factor V Leiden are not known. A nested case-control study was conducted among women with established coronary disease enrolled in 2 randomized clinical trials of HRT, the Heart and Estrogen/Progestin Replacement Study (HERS) and the Estrogen Replacement and Atherosclerosis (ERA) trial. The Leiden mutation was present in 8 (16.7%) of 48 cases with VTE compared with only 7 (6.3%) of 112 controls (odds ratio [OR]
Leiden
3.3, 95% CI 1.1 to 9.8;
P
=0.03). In women without the factor V Leiden mutation, risk associated with HRT use was significantly increased (OR
HRT
3.7, 95% CI 1.4 to 9.4;
P
<0.01). On the other hand, in women with the factor V Leiden mutation, the estimated risk associated with HRT was increased nearly 6-fold, although the CIs were wide and included unity (OR
HRT
5.7, 95% CI 0.6 to 53.9;
P
=0.13). The OR for women with the Leiden mutation who were also assigned to HRT compared with wild-type women assigned to placebo was 14.1 (95% CI 2.7 to 72.4,
P
=0.0015). In women with the factor V Leiden mutation who were treated with HRT, the estimated absolute incidence of VTE was 15.4 of 1000 per year compared with 2.0 of 1000 per year in women without the mutation who were taking a placebo (
P
=0.0015). On the basis of these data, in women with coronary disease, the estimated number needed to screen for factor V Leiden to avoid an HRT-associated VTE during 5 years of treatment is 376. If factor V Leiden genotyping becomes less expensive, it could be cost effective to screen for the presence of the mutation before instituting HRT in women with coronary disease.
Angiotensin II Type 1 Receptor Antagonism Improves Hypercholesterolemia-Associated Endothelial Dysfunction
Authors: Wassmann Sven , Hilgers Stefan , Laufs Ulrich , Böhm Michael , Nickenig Georg
Published: July 2002

Objective

Objective

—

Hypercholesterolemia-induced angiotensin II type 1 (AT
1
) receptor overexpression is thought to be a key event in the development of endothelial dysfunction.

Methods and Results

—

The effect of a 6-week treatment with the AT
1
receptor antagonist candesartan (16 mg/d) on endothelial function and serum inflammation markers was compared with the effect of treatment with placebo or the calcium channel antagonist felodipine (5 mg/d) in 47 hypercholesterolemic patients (low density lipoprotein cholesterol >160 mg/dL). Endothelial function was assessed by measurement of forearm blood flow (FBF) by venous occlusion plethysmography. FBF during reactive hyperemia was significantly improved by candesartan, whereas felodipine and placebo exerted no effect. Nitroglycerin-induced vasorelaxation and basal FBF were not altered significantly. Blood pressure and cholesterol levels were not affected significantly by any drug. Serum concentrations of 8-isoprostane, monocyte chemoattractant protein-1, and soluble intercellular adhesion molecule-1 were significantly reduced by candesartan treatment but not by placebo or felodipine (ELISA assays). Levels of high-sensitivity C-reactive protein and tumor necrosis factor-α were not altered significantly by any treatment.

Conclusions

—

These data suggest that AT
1
receptor antagonism improves endothelial function during hypercholesterolemia and that this applies not only to endothelium-dependent vasodilatation but also to oxidative stress and events involved in monocyte attraction and adhesion. AT
1
receptor blockade may potentially represent a novel approach for the prevention of vascular dysfunction associated with hypercholesterolemia that is independent of lipid-lowering and blood pressure–lowering interventions.
Saphenous Vein Endothelin System Expression and Activity in African American Patients
Authors: Grubbs Ashley L. , Anstadt Mark P. , Ergul Adviye
Published: July 2002

Objective

—

Plasma endothelin (ET)-1 levels are significantly higher in African American hypertensive patients than in white hypertensive patients. However, whether the molecular components of vascular ET-1 biosynthesis and function are altered in this population remains to be established. Accordingly, the overall goal of this study was to investigate the effects of race on vascular mRNA and protein levels of ET-converting enzyme (ECE)-1 subisoforms, ET-1, and ET receptor profiles in hypertension.

Methods and Results

—

Saphenous vein samples were obtained from African American (n=13) and white (n=15) patients undergoing coronary artery grafting surgery. The expression of preproET-1 and of ECE-1a was upregulated ∼2- and 3-fold, respectively, in African Americans. In endothelium-intact vessels, the ET
A
expression was higher in whites. In endothelium-denuded vessels, the ET
B
mRNA was 3-fold higher in African Americans, suggesting that vasoconstriction-promoting ET
B
receptors are upregulated in this population. Vascular tissue ET-1 levels and ECE-1 activity were also augmented in African American patients.

Conclusions

—

This study demonstrated that the biosynthetic pathway of ET-1 is activated to a higher degree and that the ET
B
receptor subtype expression is altered in the peripheral vasculature of African American hypertensive patients. The augmented synthesis and altered expression of ET
B
receptors may both contribute to the increased incidence of hypertension and related complications in this patient population.
Primary Prevention of Sudden Cardiac Death in Idiopathic Dilated Cardiomyopathy
Authors: Bänsch Dietmar , Antz Matthias , Boczor Sigrid , Volkmer Marius , Tebbenjohanns Jürgen , Seidl Karlheinz , Block Michael , Gietzen Frank , Berger Jürgen , Kuck Karl Heinz
Published: July 2002

Background

—

Patients with idiopathic dilated cardiomyopathy (DCM) and impaired left ventricular ejection fraction have an increased risk of dying suddenly.

Methods and Results

—

Patients with recent onset of DCM (≤9 months) and an ejection fraction ≤30% were randomly assigned to the implantation of an implantable cardioverter-defibrillator (ICD) or control. The primary end point of the trial was all-cause mortality at 1 year of follow-up. The trial was terminated after the inclusion of 104 patients because the all-cause mortality rate at 1 year did not reach the expected 30% in the control group. In August 2000, the vital status of all patients was updated by contacting patients, relatives, or local registration offices. One hundred four patients were enrolled in the trial: Fifty were assigned to ICD therapy and 54 to the control group. Mean follow-up was 22.8±4.3 months, on the basis of investigators’ follow-up. After 1 year, 6 patients were dead (4 in the ICD group and 2 in the control group). No sudden death occurred during the first and second years of follow-up. In August 2000, after a mean follow-up of 5.5±2.2 years, 30 deaths had occurred (13 in the ICD group and 17 in the control group). Cumulative survival was not significantly different between the two groups (93% and 80% in the control group versus 92% and 86% in the ICD group after 2 and 4 years, respectively).

Conclusions

—

This trial did not provide evidence in favor of prophylactic ICD implantation in patients with DCM of recent onset and impaired left ventricular ejection fraction.
High-Density Lipoprotein Restores Endothelial Function in Hypercholesterolemic Men
Authors: Spieker Lukas E. , Sudano Isabella , Hürlimann David , Lerch Peter G. , Lang Markus G. , Binggeli Christian , Corti Roberto , Ruschitzka Frank , Lüscher Thomas F. , Noll Georg
Published: July 2002

Background

—

Hypercholesterolemia is a risk factor for atherosclerosis-causing endothelial dysfunction, an early event in the disease process. In contrast, high-density lipoprotein (HDL) cholesterol inversely correlates with morbidity and mortality representing a protective effect. Therefore, we investigated the effects of reconstituted HDL on endothelial function in hypercholesterolemic men.

Methods and Results

—

Endothelium-dependent and -independent vasodilation to intraarterial acetylcholine and sodium nitroprusside (SNP), respectively, was measured by forearm venous occlusion plethysmography in healthy normo- and hypercholesterolemic men. In hypercholesterolemics, the effects of reconstituted HDL (rHDL; 80 mg/kg IV over 4 hours) on acetylcholine- and SNP-induced changes in forearm blood flow were assessed in the presence or absence of the nitric oxide (NO) synthase inhibitor L-NMMA. Hypercholesterolemics showed reduced vasodilation to acetylcholine but not to SNP compared with normocholesterolemics (
P
<0.0001). rHDL infusion increased plasma HDL cholesterol from 1.3±0.1 to 2.2±0.1 mmol/L (
P
<0.0001, n=18) and significantly enhanced the acetylcholine-induced increase in forearm blood flow without affecting that induced by SNP. rHDL infusion also improved flow-mediated dilation of the brachial artery (to 4.5±0.9% from 2.7±0.6%,
P
=0.02). NO synthase inhibition prevented the improvement in acetylcholine-induced vasodilation while leaving the response to SNP unchanged. Albumin infusion in an equivalent protein dose had no effect on vasomotion or lipid levels.

Conclusions

—

In hypercholesterolemic patients, intravenous rHDL infusion rapidly normalizes endothelium-dependent vasodilation by increasing NO bioavailability. This may in part explain the protective effect of HDL from coronary heart disease and illustrates the potential therapeutic benefit of increasing HDL in patients at risk from atherosclerosis.