bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the new ward housekeeper role in UK NHS Trusts
Authors: May Daryl , Smith Louise
Published: July 2003

In the year 2000, the UK government promoted the concept that hospital services be shaped around the needs of the patient to make their stay in hospital as comfortable as possible and advocated the introduction of a ward housekeeper role in at least 50 per cent of hospitals by 2004. This is a ward‐based non‐clinical role centred on cleaning, food service and maintenance to ensure that the basics of care are right for the patient. In 2002 the Facilities Management Graduate Centre at Sheffield Hallam University completed a series of six case studies looking at the role within different NHS Trusts. These were developed through interviews and observations with the facilities manager, ward housekeepers and nursing staff and also by collecting documentary evidence such as job descriptions, financial details and training information. Common themes were identified, relating to experiences of developing and implementing the ward housekeeper role. This paper suggests models of best practice relating to role, recruitment, induction, training, integration and management.
Social performance of free markets: issues, analysis and appraisal
Authors: Bathala Chenchuramaiah , Rao Korukonda Appa
Published: July 2003

The centralized, command models emphasized social welfare and equity, whereas in free market conditions, the market participants are primarily governed by the demand and supply factors and their objective of wealth maximization. The tension between these two approaches is most evident in the structure and organization of financial markets. This paper presents an analysis and examination of the feasibility of the commonweal principle in free market environments and offers a preliminary empirical approach to investigate this issue further.
The rising number of uninsured Americans: how adequate is our health system?
Authors: Glover Saundra H. , McCleary Karl J. , Rivers Patrick A. , Waller Raymond A.
Published: July 2003

A primary reason for the increase in uninsured Americans is due to the rising costs of health care that has caused a decline of employment‐based coverage for individuals working for small firms. According to the 1997 US Census Bureau figures, 43 percent of uninsured worked full‐time, and eight out of ten of the uninsured or their dependents were full‐time workers. While significant improvements at the state‐level have occurred to address the unmet health insurance needs of children, less emphasis has been placed on ways to improve access and utilization of health services for uninsured adults. This paper revisits where the health care debate has been over the last decade, system stresses currently being felt by providers in caring for the uninsured population, and the adequacy of the care which they receive. In addition, several incremental strategies for extending Medicaid coverage for children and their families, costs and financing projections, and implications for providers are examined.
Measuring socioeconomic health inequalities: fiction or reality?
Authors: Costa Joan , Garcia Jaume
Published: July 2003

This paper empirically examines the inequalities related to social class and income using individual self‐reported health status data. Health inequalities are estimated by different indexes using individual standardised and unstandardised health status data. The population was divided into income and social class, respectively. From this two main results are obtatined: inequalities are sensitive to the health status variable and the social position variable employed. It was found that significant health related social class inequalities were insignificant when income was employed as a reference variable.
Customer loyalty and customer loyalty programs
Authors: Uncles Mark D. , Dowling Grahame R. , Hammond Kathy
Published: July 2003

Customer loyalty presents a paradox. Many see it as primarily an attitude‐based phenomenon that can be influenced significantly by customer relationship management initiatives such as the increasingly popular loyalty and affinity programs. However, empirical research shows that loyalty in competitive repeat‐purchase markets is shaped more by the passive acceptance of brands than by strongly‐held attitudes about them. From this perspective, the demand‐enhancing potential of loyalty programs is more limited than might be hoped. Reviews three different perspectives on loyalty, and relates these to a framework for understanding customer loyalty that encompasses customer brand commitment, customer brand acceptance and customer brand buying. Uses this framework to analyze the demand‐side potential of loyalty programs. Discusses where these programs might work and where they are unlikely to succeed on any large scale. Provides a checklist for marketers.
A CIT investigation of servicescape failures and associated recovery strategies
Authors: Hoffman K. Douglas , Kelley Scott W. , Chung Beth C.
Published: July 2003

This study was undertaken to investigate service failures relating to problems with the management of the servicescape. Of the 1,370 failure critical incidents collected, 123 were identified as servicescape failures. The three primary types of servicescape failures most likely to occur, listed in order of frequency, include cleanliness issues, mechanical problems, and facility design issues. The study also identifies eight servicescape subfailure type categories and discusses failure ratings, recovery strategies, recovering ratings and customer retention rates.
Perceived quality and satisfaction in multiservice organisations: the case of Spanish public services
Authors: Bigné Enrique , Moliner Miguel A. , Sánchez Javier
Published: July 2003

The main aim of the paper is to study the causal relationship between two constructs, perceived quality and satisfaction, in the particular case of multiservice organisations. These organisations offer a range of services to their customers, so that evaluation of perceived overall quality and of satisfaction is more complex than that of a single service. The study centres on two publicly‐owned multiservice organisations: hospitals, and universities. The particular nature of multiservice organisations is that, when dealing with the influences of the dimensions of perceived quality, it is necessary to take into consideration not only the perceived quality of each of the services, but also the perceived overall quality of the multiservice organisation and the overall satisfaction with it.
Teacher‐pupil dialogue in the guided reading session
Authors: Skidmore David , Perez‐Parent Montserrat , Arnfield Simon
Published: July 2003

Drawing on the findings of an ESRC‐funded project, this article concerns the quality of teacher‐pupil dialogue in the guided reading session of the Literacy Hour and its relationship to pupils' powers of comprehension. We recorded and analysed examples of discussions during the guided reading session in four primary schools, visiting each of them three times. On each school visit, we recorded the same group of six Year 6 children (10–11‐year‐olds) working with their class teacher. The results of the study suggest that talk in this context is teacher‐dominated. The teacher: usually asks questions to which s/he already knows the answer; normally selects which pupil is going to speak next; keeps a tight grip on the topic of conversation; and does most of the talking. We argue that there is a case for making time available during the guided reading session for a period of discussion in which pupils are invited to play a more leading role in shaping the topic of conversation.
Face‐to‐face talk to support computer‐mediated discussion in a primary school literacy practice
Authors: Staarman Judith Kleine
Published: July 2003

In this study, Dutch primary school children used a computer‐mediated discussion forum to discuss the concept of horror stories. In such discussion forums children often write their contributions individually. This paper presents an ongoing empirical study in which the contributions to an electronic discussion forum from children working individually were compared to contributions from children working in dyads. Preliminary results indicated that children working in dyads around the computer wrote more contributions to the computer‐mediated discussion and were more attentive to the collaborative process, than children who wrote their contributions individually.
Talk about texts at the computer: using ICT to develop children's oral and literate abilities
Authors: Mercer Neil , Fernandez Manuel , Dawes Lyn , Wegerif Rupert , Sams Claire
Published: July 2003

This article describes the outcomes of recent research on children's talk while engaged in joint literacy activities in primary school (Year 5). The research is based on a conception of talk as a tool for ‘thinking together’, with computer software being treated as a resource for organising and focusing children's involvement in collaborative activities. The results are used to discuss the value of classroom talk and computer‐based activities for promoting children's literacy development.
The impact of the euro on Europe's financial markets
Authors: Galati Gabriele , Tsatsaronis Kostas
Published: July 2003

This paper presents an overview of the impact of the introduction of the euro on Europe's financial structure over the first four years since the start of EMU. It analyzes changes in money markets, bond markets, equity markets and foreign exchange markets. Euro's role in originating or catalyzing trends has been uneven across the spectrum of financial markets. From the supply side, banks and investors in fixed income markets have become more focused on the characteristics of individual borrowers rather than the nationality of the issuer and have built up expertise to evaluate credit risk. European equity markets have also been affected by the enhanced ability of investors to build strategies with a pan‐European perspective as prices increasingly reflected risk factors specific to industrial sectors rather than individual countries. On the borrower side, EMU has increased the attractiveness of market‐based financing methods by allowing debt issuers to tap institutional portfolios across the euro area. Lower barriers to cross‐border financial transactions have also increased the contestability of the market for financial services, be it at the wholesale or the retail level.

The introduction of the euro has also highlighted the shortcomings of existing institutional structures and areas where excessive focus on narrowly defined interests may stand in the way of realizing the full potential benefits from the new environment. Diverging legal and institutional infrastructures and market practices can impede further financial market development and deepening. Hence, the euro has put a premium on cooperation between national authorities and institution as a means of achieving a more harmonized financial environment.

The impact of EMU on depth in foreign exchange markets has been less clear‐cut, as volatility, spreads, trading volumes and liquidity appear not to have changed in a substantial way. Overall, it seems that the new currency has made some progress towards the goal of becoming a currency of international stature that would rival that of the US dollar. However, a number of the necessary next steps towards achieving this goal are also among the trickiest to implement.
From ‘Normal Incidents’ to Political Crises: Understanding the Selective Politicization of Policy Failures
Authors: Brändström Annika , Kuipers Sanneke
Published: July 2003

This article aims to enhance understanding of selective politicization processes in policy failures and examine the attempts of policy-makers to use framing strategies to allocate blame. The policy response to alleged submarine intrusions in Sweden and Dutch military involvement in the fall of Srebrenica are the two case-studies used in this article. These cases will be analysed using three perspectives derived from the literature on framing: depicting events as violations of core public values; depicting events as operational incidents or as symptoms of endemic problems; allocating accountability and blame for the occurrence and/or ‘mismanagement’ of crisis. Finally, we present a conceptual framework of the different shapes that political blaming can take when certain framing strategies are adopted.
Long-Term Region-Wide Declines in Caribbean Corals
Authors: Gardner Toby A. , Côté Isabelle M. , Gill Jennifer A. , Grant Alastair , Watkinson Andrew R.
Published: July 2003

We report a massive region-wide decline of corals across the entire Caribbean basin, with the average hard coral cover on reefs being reduced by 80%, from about 50% to 10% cover, in three decades. Our meta-analysis shows that patterns of change in coral cover are variable across time periods but largely consistent across subregions, suggesting that local causes have operated with some degree of synchrony on a region-wide scale. Although the rate of coral loss has slowed in the past decade compared to the 1980s, significant declines are persisting. The ability of Caribbean coral reefs to cope with future local and global environmental change may be irretrievably compromised.
Influence of the Van Hove Singularity on the Specific Heat Jump in BCS Superconductors
Authors: Mishonov Todor , Drechsler Stefan-Ludwig , Penev Evgeni
Published: July 2003

Within the weak-coupling BCS scheme we derive a general form of the coefficients in the Ginzburg–Landau expansion of the free energy of a superconductor for the case of a Fermi level close to a Van Hove singularity (VHS). A simple expression for the influence of the VHS on the specific heat jump is then obtained for the case where gaps for different bands are distinct but nearly constant at the corresponding sheets of the Fermi surface.
Heat Treatment Effect on the Structural and Optical Properties ofCdGa2S4Thin Films
Authors: El-Nahass M. M. , Soliman H. S. , El-Shazly E. A. A.
Published: July 2003

CdGa2S4was prepared in powder form by reacting CdS and Ga2S3. The powder had a tetragonal crystal structure with lattice parameters, a = 0.559 ± 0.005 nm , c = 1.008 ± 0.009 nm and c/a = 1.803. CdGa2S4films deposited by thermal evaporation of the powder were noncrystalline. After annealing, the CdGa2S4thin films contain crystals with the tetragonal crystal structure. The optical constants (the refractive index n, the absorption index k and the absorption coefficient α) were determined for CdGa2S4thin films in the thickness range 170–452 nm. It was found that both n and k are independent of the film thickness and both are slightly different as deposited and annealed films. The refractive index shows anomalous dispersion in the spectral range 300–700 nm. The high frequency dielectric constant ε∞was determined for the as-deposited and after being annealed films. It was found that ε∞= 5.12 and 5.52 for the as-deposited and after being annealed films respectively. Graphical representations of (αhν)r= f(hν) yield three linear parts, indicating the existence of two indirect and one direct allowed transitions. The values of [Formula: see text], [Formula: see text] and [Formula: see text] for CdGa2S4for the as-deposited and annealed films are presented.
Electron Tunneling in Small-Area Junctions
Authors: Khachaturov Alexander I.
Published: July 2003

Electron tunneling in small-area junctions has been treated. It is found that at the appropriate set of barrier parameters and electronic characteristics of the electrodes, the quantization of the lateral wave vector component manifests itself in the differential tunneling conductance as quite noticeable singularities. The dependance of the second derivative of the tunnel current versus the bias voltage calculated for the perfectly smooth quantized electrode should contain distinct periodic dips. It is shown that for real not perfectly smooth electrodes the resonance structure caused by the commensurate states may be observed.
An Improved Ray Shooting Method for Constructive Solid Geometry Models Via Tree Contraction
Authors: Goodrich Michael T.
Published: July 2003

In the Constructive Solid Geometry (CSG) representation a geometric object is described as the hierarchical combination of a number of primitive shapes using the operations union, intersection, subtraction, and exclusive-union. This hierarchical description defines an expression tree, T, called the CSG tree, with leaves associated with primitive shapes, internal nodes associated with operations, and whose "value" is the geometric object. Evaluation of CSG trees is an important computation that arises in many rendering and analysis problems for geometric models, with ray shooting (also known as "ray casting") being one of the most important. Given any CSG tree T, which may be unbalanced, we show how to convert T into a functionally-equivalent binary tree, D, that is balanced. We demonstrate the utility of this conversion by showing how it can be used to improve the worst-case running time for ray shooting against a CSG model from O(n2) to O(n log n), which is optimal. In addition, the practicality of our method has been demonstrated in experimental benchmarking tests using the BRL-CAD package.
Geosheet
Authors: Lee D. T. , Shen Chin-Fang , Sheu Dennis S.
Published: July 2003

GeoSheet (version 1.0) is an interactive visualization tool for visualizing geometric algorithms in distributed environments. It provides features such as interactive visualization of program states for debugging, high-level graphical input/output manipulation facilities for geometric objects, reuse of existing data structures and algorithms implementation, and more importantly distributed executions on heterogeneous machines at different sites. To minimize development effort of the tool we make use of existing software packages available in public domain. Specifically we extend Xfig with a message-driven interface and a socket-based interprocess communication (IPC) mechanism. This extended-Xfig is the backbone of this version of the tool. Object-oriented programming methodology is used to construct the visualization interface. By deriving from traditional data type and algorithm libraries, our abstract GeoObject representation super-classes are easy to use, easy to construct, and highly portable. Although GeoSheet is not restricted to a particular application domain or any programming language, this release only contains geometric algorithm implementations in C++ and LEDA. We hope that the geometric algorithm designers will find it useful when they develop their algorithms.
Rounding Arrangements Dynamically
Authors: Guibas Leonidas J. , Marimont David H.
Published: July 2003

We describe a robust, dynamic algorithm to compute the arrangement of a set of line segments in the plane, and its implementation. The algorithm is robust because, following Greene7 and Hobby,11 it rounds the endpoints and intersections of all line segments to representable points, but in a way that is globally topologically consistent. The algorithm is dynamic because, following Mulmuley,16 it uses a randomized hierarchy of vertical cell decompositions to make locating points, and inserting and deleting line segments, efficient. Our algorithm is novel because it marries the robustness of the Greene and Hobby algorithms with Mulmuley's dynamic algorithm in a way that preserves the desirable properties of each.
Polyhedral Assembly Partitioning Using Maximally Covered Cells in Arrangements of Convex Polytopes
Authors: Guibas Leonidas J. , Halperin Dan , Hirukawa Hirohisa , Latombe Jean-Claude , Wilson Randall H.
Published: July 2003

We study the following problem: Given a collection A of polyhedral parts in 3D, determine whether there exists a subset S of the parts that can be moved as a rigid body by infinitesimal translation and rotation, without colliding with the rest of the parts, A\S. A negative result implies that the object whose constituent parts are the collection A cannot be taken apart with two hands. A positive result, together with the list of movable parts in S and a direction of motion for S, can be used by an assembly sequence planner (it does not, however, give the complete specification of an assembly operation). This problem can be transformed into that of traversing an arrangement of convex polytopes in the space of directions of rigid motions. We identify a special type of cells in that arrangement, which we call the maximally covered cells, and we show that it suffices for the problem at hand to consider a representative point in each of these special cells rather than to compute the entire arrangement. Using this observation, we devise an algorithm which is complete (in the sense that it is guaranteed to find a solution if one exists), simple, and improves significantly over the best previously known solutions. We describe an implementation of our algorithm and report experimental results obtained with this implementation.
A Complete Implementation for Computing General Dimensional Convex Hulls
Authors: Emiris Ioannis Z.
Published: July 2003

We present a robust implementation of the Beneath-Beyond algorithm for computing convex hulls in arbitrary dimension. Certain techniques used are of independent interest in the implementation of geometric algorithms. In particular, two important, and often complementary, issues are studied, namely exact arithmetic and degeneracy. We focus on integer arithmetic and propose a general and efficient method for its implementation based on modular arithmetic. We suggest that probabilistic modular arithmetic may be of wide interest, as it combines the advantages of modular arithmetic with the speed of randomization. The use of perturbations as a method to cope with input degeneracy is also illustrated. A computationally efficient scheme is implemented which, moreover, greatly simplifies the task of programming. We concentrate on postprocessing, often perceived as the Achilles' heel of perturbations. Experimental results illustrate the dependence of running time on the various input parameters and attempt a comparison with existing programs. Lastly, we discuss the visualization capabilities of our software and illustrate them for problems in computational algebraic geometry. All code is publicly available.
A Robust Implementation for Three-Dimensional Delaunay Triangulations
Authors: Mücke Ernst P.
Published: July 2003

This paper presents an implementation for Delaunay triangulations of three-dimensional point sets. The code uses a variant of the randomized incremental flip algorithm and employs symbolic perturbation to achieve robustness. The algorithm's theoretical time complexity is quadratic in n, the number of input points, and this is optimal in the worst case. However, empirical running times are proportional to the number of triangles in the final triangulation, which is typically linear in n. Even though the symbolic perturbation scheme relies on exact arithmetic, the resulting code is efficient in practice. This is due to a careful implementation of the geometric primitives and the arithmetic module. The source code is available on the Internet.
Decision Trees for Geometric Models
Authors: Arkin Esther M. , Meijer Henk , Mitchell Joseph S. B. , Rappaport David , Skiena Steven S.
Published: July 2003

A fundamental problem in model-based computer vision is that of identifying which of a given set of geometric models is present in an image. Considering a "probe" to be an oracle that tells us whether or not a model is present at a given point, we study the problem of computing efficient strategies ("decision trees") for probing an image, with the goal to minimize the number of probes necessary (in the worst case) to determine which single model is present. We show that a ⌈l g k⌉ height binary decision tree always exists for k polygonal models (in fixed position), provided (1) they are non-degenerate (do not share boundaries) and (2) they share a common point of intersection. Further, we give an efficient algorithm for constructing such decision tress when the models are given as a set of polygons in the plane. We show that constructing a minimum height tree is NP-complete if either of the two assumptions is omitted. We provide an efficient greedy heuristic strategy and show that, in the general case, it yields a decision tree whose height is at most ⌈l g k⌉ times that of an optimal tree. Finally, we discuss some restricted cases whose special structure allows for improved results.
Voronoi Diagrams of Moving Points
Authors: Albers Gerhard , Guibas Leonidas J. , Mitchell Joseph S. B. , Roos Thomas
Published: July 2003

Consider a set of n points in d-dimensional Euclidean space, d ≥ 2, each of which is continuously moving along a given individual trajectory. As the points move, their Voronoi diagram changes continuously, but at certain critical instants in time, topological events occur that cause a change in the Voronoi diagram. In this paper, we present a method of maintaining the Voronoi diagram over time, at a cost of O( log n) per event, while showing that the number of topological events has an upper bound of O(ndλs(n)), where λs(n) is the (nearly linear) maximum length of a (n,s)-Davenport-Schinzel sequence, and s is a constant depending on the motions of the point sites.

In addition, we show that if only k points are moving (while leaving the other n - k points fixed), there is an upper bound of O(knd-1λs(n)+(n-k)dλ s(k)) on the number of topological events.
Computational Geometry Column 33
Authors: O'Rourke Joseph
Published: July 2003

Several recent SIGGRAPH papers on surface simplification are described.
Computing the Angularity Tolerance
Authors: De Berg Mark , Meijer Henk , Overmars Mark , Wilfong Gordon
Published: July 2003

In computational metrology one needs to compute whether an object satisfies specifications of shape within an acceptable tolerance. To this end positions on the object are measured, resulting in a collection of points in space. From this collection of points one wishes to extract information on flatness, roundness, etc. of the object. In this paper we study one particular feature of objects, the angularity. The angularity indicates how well a plane makes a specified angle with another plane. We study the problem in 2-dimensional space (where the planes become lines) and in 3-dimensional space. In 2-dimensional space the problem is equivalent to computing the smallest wedge of the given angle that contains all the points. We give an O(n2 log n) algorithm for this problem. In 3-dimensional space we study the more restricted problem where one of the planes is known (a datum plane). In this case the problem is equivalent to asking for the smallest width 3-dimensional strip that contains all the points and makes a given angle with the datum plane. We give an O(n log n) algorithm to solve this version. We also show that in the case of uncertainty in the measured points, upperbounds and lowerbounds on the width can be computed in similar time bounds.
A Database for the Representation of Assembly Features in Mechanical Products
Authors: Jabbour Toni , Mascle Christian , Maranzana Roland
Published: July 2003

This paper deals with a representation of assembly features. Modeling the product at each stage of the assembly process, taking into account all pertinent geometrical, technological and functional data, distinguishes our model from the ones described in the literature. A representation such as this also greatly contributes to the designing of a system that includes the various stages in the development and manufacture of a product. To reach our goal, we let the user interactively input a set of features that cannot be supported by a solid modeler. The system automatically deduces other features pertaining to faces, parts and subassemblies. Given the object-oriented structure that we chose, the different features can be abstractly represented as object attributes. This can assist the method engineer in the automatic generation of assembly sequences or resources. Examples are given to validate the concept.
Free-Form Modeling in Bilateral Brep and CSG Representation Schemes
Authors: Menon Jai , Guo Baining
Published: July 2003

This paper presents a unified approach for incorporating free-form solids in bilateral Brep and CSG representation schemes, by resorting to low-degree (quadratic, cubic) algebraic surface patches. We develop a general CSG solution that represents a free-form solid as a boolean combination of a direct term and a complicated delta term. This solution gives rise to the trunctet-subshell conditions, under which the delta term computation can be obviated. We use polyhedral smoothing to construct a Brep consisting of quadratic algebraic patches that meet with tangent-plane continuity, such that the trunctet-subshell conditions are guaranteed automatically. This guarantee is not currently available for cubic patches. The general CSG solution thus applies whenever trunctet-subshell conditions are violated, e.g. sometimes for cubic patches or sometimes for patches of any degree that are subject to shape control operations. Manifold solids of arbitrary topology can be represented in our dual representation system. Ensuing CSG constructs are parallel processed on the RayCasting Engine to support a wide range of solid modeling applications, including general sweeping, Minkowski operations, NC machining, and touch-sense probing.
RENORMALIZATION GROUP APPROACH FOR FOREST FIRE MODELS
Authors: LORETO V. , PIETRONERO L. , VESPIGNANI A. , ZAPPERI S.
Published: July 2003

We introduce a Renormalization scheme for the one- and two-dimensional Forest-Fire models in order to characterize the nature of the critical state and its scale invariant dynamics. We show the existence of a relevant scaling field associated with a repulsive fixed point. These models are therefore critical in the usual sense because the fixed point value of the control parameter is crucial in order to get criticality and it is not just the expression of a time scale separation. This general scheme allows us to calculate analytically the critical exponents for the one- and two-dimensional cases. The results obtained are in good agreement with exact or numerical results.
MIXING AND DISORDER
Authors: GUYON ETIENNE
Published: July 2003

Ordinary diffusion equation as described by a Brownian walk applies to a large number of physical processes. However, qualitative deviations are obtained in a number of situations involving correlations or large distributions of steps or waiting times in the walk. Anomalous diffusion laws result which can be expressed in terms of fractal Brownian walks. We examine from an experimental point of view some manifestations of such systems: dispersion in porous media, chaotic advection, turbulent flows.
A DIMENSION FORMULA FOR SELF-SIMILAR AND SELF-AFFINE FRACTALS
Authors: HUBER GREG , JENSEN MOGENS H. , SNEPPEN KIM
Published: July 2003

A geometric and very general relation between the size distribution and the fractal dimensions of a set of objects is presented. The applications are numerous, ranging from fragmentation experiments to time series. For example, it may be used to understand the fragment-size distribution of fragmenting gypsum. The formalism also generalizes to self-affine fractals, and here it is applied to the scaling properties of self-interactions in (1+1)-d directed percolation.
ANOMALOUS ROUGHENING IN A RANDOM SINE GORDON CHAIN
Authors: RANGEL R. , GUERRERO L.E.
Published: July 2003

The appearance of solitons in a random sine-Gordon system is related to the roughening exponent, ζ, defined as the scaling exponent of the length of the ensemble average of the standard deviation of the height of the spatiotemporal profile. We show that the coherence of the ordered state appears to have three different regimes with well-defined crossover lengths. After the activation of solitons, there is a very interesting crossover from non-Kardar-Parisi-Zhang6 behavior (ζ~0.7) to KPZ behavior (ζ~0.5); additionally, for sufficiently large scales, a crossover to a zero roughening exponent takes place. For the transient we calculate from flat initial conditions the common dynamic exponent (ζ/z~0.9) for all these regimes. This last result reveals that the surface grows faster than is predicted by the KPZ model. We point out the connection of our results to the Sneppen universality class9 and discuss the crossover between the conditions of global dynamics and the conditions of local dynamics at different length scales in the stationary regime.
NONEXTENSIVE THERMOSTATISTICS AND FRACTALS
Authors: TSALLIS CONSTANTINO
Published: July 2003

We discuss the modifications of standard, extensive, thermodynamics that long-range interactions are expected to introduce. In addition to that, by using the generalized entropic form [Formula: see text] (q∈ℜq=1 corresponds to the standard entropy S1≡−kB ∑i pi ln pi) we establish, through a simple identification, that Sq=0 is equivalent to q=df/d, where df and d respectively are fractal and Euclidean dimensions.
FOUNDATIONS OF FRACTIONAL DYNAMICS
Authors: HILFER R.
Published: July 2003

Time flow in dynamical systems is reconsidered in the ultralong time limit. The ultralong time limit is a limit in which a discretized time flow is iterated infinitely often and the discretization time step is infinite. The new limit is used to study induced flows in ergodic theory, in particular for subsets of measure zero. Induced flows on subsets of measure zero require an infinite renormalization of time in the ultralong time limit. It is found that induced flows are given generically by stable convolution semigroups and not by the conventional translation groups. This could give new insight into the origin of macroscopic irreversibility. Moreover, the induced semigroups are generated by fractional time derivatives of orders less than unity, and not by a first order time derivative. Invariance under the induced semiflows therefore leads to a new form of stationarity, called fractional stationarity. Fractionally stationary states are dissipative. Fractional stationarity also provides the dynamical foundation for a previously proposed generalized equilibrium concept.
FRACTAL GEOMETRY OF FINANCIAL TIME SERIES
Authors: EVERTSZ CARL J.G.
Published: July 2003

A simple quantitative measure of the self-similarity in time-series in general and in the stock market in particular is the scaling behavior of the absolute size of the jumps across lags of size k. A stronger form of self-similarity entails that not only this mean absolute value, but also the full distributions of lag-k jumps have a scaling behavior characterized by the above Hurst exponent. In 1963, Benoit Mandelbrot showed that cotton prices have such a strong form of (distributional) self-similarity, and for the first time introduced Lévy’s stable random variables in the modeling of price records. This paper discusses the analysis of the self-similarity of high-frequency DEM-USD exchange rate records and the 30 main German stock price records. Distributional self-similarity is found in both cases and some of its consequences are discussed.
Platelet Adhesion to Collagen and Collagen-Related Peptide Under Flow
Authors: Polanowska-Grabowska Renata , Gibbins Jonathan M. , Gear Adrian R.L.
Published: July 2003

Objective—

Platelet stimulation by collagen and collagen-related peptides (CRPs) is associated with activation of protein tyrosine kinases. In the present study, we investigated the role of Src family tyrosine kinases in the initial adhesion events of human platelets to collagen and cross-linked CRP.

Methods and Results—

Under arterial flow conditions, a glycoprotein VI–specific substrate, cross-linked CRP, caused rapid (<2 second) platelet retention and protein tyrosine phosphorylation that were markedly decreased by the Src family kinase inhibitor pyrozolopyrimidine (PP2) or by aggregation inhibitor GRGDSP. CRP-induced platelet retention was transient, and 90% of single platelets or aggregates detached within seconds. PP2, although having no effect on RGD peptide–binding to CRP, completely blocked aggregation and tyrosine phosphorylation of Syk and phospholipase Cγ2 (PLCγ2). In contrast, PP2 weakly (<30%) suppressed firm adhesion to collagen mediated primarily by the α
2
β
1
integrin. Although PP2 prevented activation of Syk and PLCγ2 in collagen-adherent platelets, tyrosine phosphorylation of several unidentified protein bands persisted, as did autophosphorylation of pp125
FAK
.

Conclusions—

These findings indicate that activation of Src-tyrosine kinases Syk and PLCγ2 is not required for the initial stable attachment of human platelets to collagen and for FAK autophosphorylation. However, Src-tyrosine kinases are critical for glycoprotein VI–mediated signaling leading to platelet aggregation.
Tumor Necrosis Factor-α Promotes Macrophage-Induced Vascular Smooth Muscle Cell Apoptosis by Direct and Autocrine Mechanisms
Authors: Boyle Joseph J. , Weissberg Peter L. , Bennett Martin R.
Published: July 2003

Objective—We have previously shown that human macrophages induce human plaque vascular smooth muscle cell (VSMC) apoptosis by cell-cell proximity, Fas-L, and nitric oxide (NO), thereby predisposing to plaque rupture. This study sought to analyze whether tumor necrosis factor-α (TNF-α) contributes additionally to macrophage-induced VSMC apoptosis.

Methods and Results—Macrophage-induced VSMC apoptosis was examined in direct coculture. Antagonistic antibodies to TNF-receptor (R1) inhibited VSMC apoptosis, and preincubation of monocytes and VSMCs indicated that TNF-R1 on both cell types contributed to macrophage-induced VSMC apoptosis. Correspondingly, both monocytes and VSMCs expressed TNF-R1, and macrophages expressed cell surface TNF-α. Two NO donors upregulated VSMC surface TNF-R1, and exogenous TNF-α induced VSMC apoptosis synergistically with the NO donor diethylenetriamine/NO, indicating that NO sensitizes VSMCs to TNF-α. Neutralizing anti–TNF-R1 antibodies inhibited macrophage activation assessed by Fas-L expression and NO secretion.

Conclusions—TNF-α promotes macrophage-induced VSMC apoptosis by autocrine and direct pathways.
Effect of Glycoprotein IIb/IIIa Antagonist Abciximab on Monocyte-Platelet Aggregates and Tissue Factor Expression
Authors: Steiner Sabine , Seidinger Daniela , Huber Kurt , Kaun Christoph , Minar Erich , Kopp Christoph W.
Published: July 2003

Objective—Activated platelets rapidly adhere to monocytes and upregulate the expression of tissue factor (TF), the major trigger of the coagulation cascade. In this study, we examined the effect of abciximab, a nonselective glycoprotein IIb/IIIa-receptor antagonist, on monocyte TF expression in thrombin receptor activator–stimulated whole blood in vitro.

Methods and Results—Abciximab (50 μg/mL) reduced the mass of platelets attached to monocytes, measured by the mean fluorescence intensity (MFI) of CD42b on CD14+cells, 1 (CD42b, 471±197 versus 1073±217 MFI, mean±SD,P<0.05), 5, and 10 minutes after thrombin receptor activator stimulation of whole blood to the same extent as anti–P-selectin (50 μg/mL; 288±177 MFI,P<0.05) when determined by flow cytometry. In parallel, the expression of the platelet activation marker P-selectin colocalized with CD14+monocytes was reduced up to 25% by abciximab at the same time points. Expression of monocyte TF antigen (CD14+/TF+, 39.9±8.7% versus 66.3±19.9%,P<0.05), chromogenic TF-activity (TF, 8.4±1.9 versus 13.2±2.8 U, arbitrary units,P<0.05), and TF mRNA was suppressed in the presence of abciximab as a consequence of reduced platelet mass attached to monocytes.

Conclusions—Our data suggest that heterotypic monocyte-platelet aggregates are a target for abciximab, which suppresses monocyte TF because of a reduction of monocyte-platelet cross talk.
Bradykinin Receptor Antagonism and Endothelial Tissue Plasminogen Activator Release in Humans
Authors: Witherow Fraser N. , Dawson Pamela , Ludlam Christopher A. , Webb David J. , Fox Keith A.A. , Newby David E.
Published: July 2003

Objective—

We sought to assess pharmacodynamic responses to the bradykinin antagonist B9340 and to determine the contribution of the endothelial bradykinin receptor to stimulated tissue plasminogen activator (t-PA) release in humans.

Methods and Results—

Bilateral forearm blood flow and plasma fibrinolytic variables were measured in 8 volunteers during 100 minutes of intrabrachial infusions of saline placebo, B9340 at 4.5 nmol/min, or B9340 at 13.5 nmol/min. On each occasion, intra-arterial bradykinin (30 to 3000 pmol/min) and substance P (4 to 16 pmol/min) were coinfused for 10 minutes at each dose. To assess the onset and offset of action, 6 additional subjects on 2 occasions received intra-arterial bradykinin (100 pmol/min) for 60 minutes with a coinfusion of either saline placebo or B9340 (13.5 nmol/min) for 12 minutes. During placebo infusion, bradykinin and substance P caused dose-dependent vasodilatation in the infused forearm (
P
<0.001). B9340 caused a dose-dependent inhibition of bradykinin-induced forearm vasodilatation and t-PA release (
P
<0.001) without affecting substance P–induced vasodilatation or t-PA release (
P
=NS). B9340 caused a reversible inhibition of bradykinin-induced vasodilatation (
P
<0.001) with a rapid onset and offset of action.

Conclusions—

B9340 is a potent, reversible, and selective competitive receptor antagonist of bradykinin-induced vasodilatation and t-PA release in humans.
High Pressure Induces Superoxide Production in Isolated Arteries Via Protein Kinase C–Dependent Activation of NAD(P)H Oxidase
Authors: Ungvari Zoltan , Csiszar Anna , Huang An , Kaminski Pawel M. , Wolin Michael S. , Koller Akos
Published: July 2003

Background—

Oxidative stress seems to be present in all forms of hypertension. Thus, we tested the hypothesis that high intraluminal pressure (P
i
) itself, by activating vascular oxidases, elicits increased superoxide (O
2
·−
) production interfering with flow-induced dilation.

Methods and Results—

Isolated, cannulated rat femoral arterial branches were exposed in vitro (for 30 minutes) to normal P
i
(80 mm Hg) or high P
i
(160 mm Hg). High P
i
significantly increased vascular O
2
·−
production (as measured by lucigenin chemiluminescence and ethidium bromide fluorescence) and impaired endothelium-dependent dilations to flow; these effects could be reversed by superoxide dismutase. Administration of the NAD(P)H oxidase inhibitor diphenyleneiodonium, apocynin, the protein kinase C (PKC) inhibitor chelerythrine or staurosporin or the removal of extracellular Ca
2+
during high P
i
treatment prevented the increases in O
2
·−
production, whereas administration of losartan or captopril had no effect. High P
i
resulted in significant increases in intracellular Ca
2+
([Ca
2+
]
i
) in the vascular wall (fura 2 fluorescence) and phosphorylation of PKCα (Western blotting). The PKC activator phorbol myristate acetate significantly increased vascular O
2
·−
production, which was inhibited by superoxide dismutase, diphenyleneiodonium, chelerythrine, or removal of extracellular Ca
2+
. Both high P
i
and phorbol myristate acetate increased the phosphorylation of the NAD(P)H oxidase subunit p47

phox

.

Conclusion—

High P
i
itself elicits arterial O
2
·−
production, most likely by PKC-dependent activation of NAD(P)H oxidase, thus providing a potential explanation for the presence of oxidative stress and endothelial dysfunction in various forms of hypertension and the vasculoprotective effect of antihypertensive agents of different mechanisms of action.
Cloning of a Novel Prolyl 4-Hydroxylase Subunit Expressed in the Fibrous Cap of Human Atherosclerotic Plaque
Authors: Van Den Diepstraten Caroline , Papay Karen , Bolender Zuzana , Brown Arthur , Pickering J. Geoffrey
Published: July 2003

Background—

The production of collagen is fundamental to atherosclerosis and critically dependent on posttranslational modification by prolyl 4-hydroxylase.

Methods and Results—

We report the cloning of a novel prolyl 4-hydroxylase catalytic (α) subunit from human vascular smooth muscle cells. The peptide displayed conservation of critical residues for interacting with Fe
2+
and 2-oxoglutarate, essential cosubstrates for prolyl 4-hydroxylase activity. Furthermore, when the recombinant protein was expressed in cells, it associated with the β-subunit of prolyl 4-hydroxylase and could catalyze prolyl 4-hydroxylation of a collagen-like peptide. The tissue distribution was dissimilar from that of the 2 previously cloned α-subunits, suggesting a role beyond redundancy. Importantly, the novel gene was expressed in the fibrous cap of human carotid atherosclerotic lesions.

Conclusions—

The discovery of a novel prolyl 4-hydroxylase α-subunit, here termed the α(III)-subunit, suggests a new participant in collagen synthesis that, in view of the expression findings, may be relevant to atherosclerotic disease.
Carotid Intima-Media Thickness Is Associated With Premature Parental Coronary Heart Disease
Authors: Wang Thomas J. , Nam Byung-Ho , D’Agostino Ralph B. , Wolf Philip A. , Lloyd-Jones Donald M. , MacRae Calum A. , Wilson Peter W. , Polak Joseph F. , O’Donnell Christopher J.
Published: July 2003

Background—

A family history of coronary heart disease (CHD) is an independent risk factor for cardiovascular events. However, the mechanisms underlying this susceptibility have not been fully elucidated. We hypothesized that an important mediator of the familial predisposition to CHD is subclinical atherosclerosis, which is detectable by noninvasive imaging.

Methods and Results—

We studied 1662 subjects (mean age 57, 51% women) in the Framingham Offspring Study who underwent carotid ultrasonography and had both biological parents in the original (parental) cohort. Parental CHD events were validated prospectively by a physician endpoint committee. The associations of carotid intima-media thickness (IMT) with premature parental CHD (occurring before age 60) and any parental CHD (no age restriction) were examined in age- and multivariable-adjusted analyses. Age-adjusted mean internal carotid IMT was higher in subjects who had at least one parent with premature CHD than in those without a validated parental history of premature CHD (men 1.13 versus 1.04 mm,
P
<0.01; women 0.92 versus 0.85 mm,
P
=0.03). In both sexes, these differences remained significant after adjustment for cardiovascular risk factors. In analyses without a restriction on parental age of CHD onset, the association between carotid IMT and parental CHD was not statistically significant. There was also no significant association of common carotid IMT with premature or any parental CHD.

Conclusions—

These findings suggest that subclinical atherosclerosis, assessed in the carotid arteries, is more prevalent in individuals with a family history of CHD. Early-onset parental CHD, in particular, identifies offspring with a strong familial predisposition to atherosclerosis.