bluuebunny/crossref_metadata_2025 huggingface dataset:
Sunlight and mortality from breast, ovarian, colon, prostate, and non-melanoma skin cancer: a composite death certificate based case-control study
Authors: Freedman D M , Dosemeci M , McGlynn K
Published: July 2002

Objectives: To explore whether mortality from female breast, ovarian, colon, and prostate cancer were negatively associated with exposure to sunlight.

Methods:A death certificate based case-control study of mortality was conducted into five cancers: female breast, ovarian, colon, prostate, and non-melanoma skin cancer (as a positive control) to examine associations with residential and occupational exposure to sunlight. Cases were all deaths from these cancers between 1984 and 1995 in 24 states of the United States. Controls, which were age frequency matched to a series of cases, excluded deaths from cancer and certain neurological diseases. Multiple logistic regression was used in a model that included age, sex, race, residential exposure to sunlight (based on region), and socioeconomic status, occupational exposure to sunlight, and physical activity (the last three based on usual occupation).

Results: Residential exposure to sunlight was negatively and significantly associated with mortality from female breast, ovarian, prostate, and colon cancer. Only female breast and colon cancer, however, also showed significant negative associations with jobs with the highest occupational exposure to sunlight (odds ratio (OR) 0.82 (95% confidence interval (95% CI) 0.70 to 0.97) for female breast cancer; OR 0.90 (95% CI 0.86 to 0.94) for colon cancer). For both cancers, the negative association with occupational sunlight was greatest in the geographical region of highest exposure to sunlight and was independent of physical activity on the job. Non-melanoma skin cancer, as expected, was positively associated with both residential and occupational sunlight.

Conclusions: In this exploratory study, unlike mortality from non-melanoma skin cancer, mortality from female breast cancer and colon cancer were negatively associated with both residential and occupational sunlight.
Job stress, fatigue, and job dissatisfaction in Dutch lorry drivers: towards an occupation specific model of job demands and control
Authors: de Croon E M , Blonk R W B , de Zwart B C H , Frings-Dresen M H W , Broersen J P J
Published: July 2002

Objectives:Building on Karasek's model of job demands and control (JD-C model), this study examined the effects of job control, quantitative workload, and two occupation specific job demands (physical demands and supervisor demands) on fatigue and job dissatisfaction in Dutch lorry drivers.

Methods:From 1181 lorry drivers (adjusted response 63%) self reported information was gathered by questionnaire on the independent variables (job control, quantitative workload, physical demands, and supervisor demands) and the dependent variables (fatigue and job dissatisfaction). Stepwise multiple regression analyses were performed to examine the main effects of job demands and job control and the interaction effect between job control and job demands on fatigue and job dissatisfaction.

Results:The inclusion of physical and supervisor demands in the JD-C model explained a significant amount of variance in fatigue (3%) and job dissatisfaction (7%) over and above job control and quantitative workload. Moreover, in accordance with Karasek's interaction hypothesis, job control buffered the positive relation between quantitative workload and job dissatisfaction.

Conclusions:Despite methodological limitations, the results suggest that the inclusion of (occupation) specific job control and job demand measures is a fruitful elaboration of the JD-C model. The occupation specific JD-C model gives occupational stress researchers better insight into the relation between the psychosocial work environment and wellbeing. Moreover, the occupation specific JD-C model may give practitioners more concrete and useful information about risk factors in the psychosocial work environment. Therefore, this model may provide points of departure for effective stress reducing interventions at work.
Chronic subdural haematoma in the elderly
Authors: Adhiyaman V , Asghar M , Ganeshram K N , Bhowmick B K
Published: July 2002

Chronic subdural haematoma is predominantly a disease of the elderly. It usually follows a minor trauma. A history of direct trauma to the head is absent in up to half the cases. The common manifestations are altered mental state and focal neurological deficit. Neurological state at the time of diagnosis is the most important prognostic factor. Morbidity and mortality is higher in the elderly but outcome is good in patients who undergo neurosurgical intervention.
Favourite movie stars, their tobacco use in contemporary movies, and its association with adolescent smoking
Authors: Tickle Jennifer J , Sargent James D , Dalton Madeline A , Beach Michael L , Heatherton Todd F
Published: July 2002

OBJECTIVE

To assess the relation between adolescents' favourite movie stars, the portrayal of tobacco use by those stars in contemporary motion pictures, and adolescent smoking.

DESIGN AND SETTING

632 students (sixth to 12th grade, ages 10–19 years) from five rural New England public schools completed a voluntary, self administered survey in October 1996. The survey assessed tobacco use, other variables associated with adolescent smoking, and favourite movie star. In addition, tobacco use by 43 selected movie stars was measured in films between 1994 and 1996.

OUTCOME MEASURES

Students were categorised into an ordinal five point index (tobacco status) based on their smoking behaviour and their smoking susceptibility: non-susceptible never smokers, susceptible never smokers, non-current experimenters, current experimenters, and smokers. We determined the adjusted cumulative odds of having advanced smoking status based on the amount of on-screen tobacco use by their favourite film star.

RESULTS

Of the 43 stars, 65% used tobacco at least once, and 42% portrayed smoking as an essential character trait in one or more films. Stars who smoked more than twice in a film were considered smokers. For adolescents whose favourite stars smoked in only one film, the odds of being higher on the smoking index was 0.78 (95% confidence interval (CI) 0.53 to 1.15). For adolescents whose favourite stars smoked in two films, the odds of being higher on the smoking index was 1.5 (95% CI 1.01 to 2.32). For adolescents whose favourite stars smoked in three or more films (Leonardo DiCaprio, Sharon Stone, John Travolta), the odds of being higher on the smoking index was 3.1 (95% CI 1.34 to 7.12). Among never smokers (n = 281), those who chose stars who were smokers in three or more films were much more likely to have favourable attitudes toward smoking (adjusted odds ratio 16.2, 95% CI 2.3 to 112).

CONCLUSIONS

Adolescents who choose movie stars who use tobacco on-screen are significantly more likely to have an advanced smoking status and more favourable attitudes toward smoking than adolescents who choose non-smoking stars. This finding supports the proposition that the portrayal of tobacco use in contemporary motion pictures, particularly by stars who are admired by adolescents, contributes to adolescent smoking.
The association of smoking and the cost of military training
Authors: Klesges Robert C , Haddock C Keith , Chang Cyril F , Talcott G Wayne , Lando Harry A
Published: July 2002

OBJECTIVE

To determine if premature discharge from the US Air Force was associated with the smoking status of recruits.

DESIGN AND SETTING

A total of 29 044 US Air Force personnel recruited from August 1995 to August 1996 were administered baseline behavioural risk assessment surveys during basic military training. They were tracked over a 12 month period to determine those who were prematurely discharged.

MAIN OUTCOME MEASURES

Excess training costs as a result of premature discharge.

RESULTS

In this 12 month period, 14.0% of those entering the US Air Force were discharged at a one year follow up. In both univariate and multivariate models, the best single predictor of early discharge was smoking status. Overall, 11.8% of non-smokers versus 19.4% of smokers were prematurely discharged (relative risk 1.795).

CONCLUSIONS

Using US Department of Defense data on the cost of military training, recruits who smoke in the US Air Force are associated with $18 million per year in excess training costs. Applied to all service branches, smoking status, which represents a constellation of underlying behaviours and attitudes that can contribute to early discharge, is associated with over $130 million per year in excess training costs.
Science in regulatory policy making: case studies in the development of workplace smoking restrictions
Authors: Bero Lisa A , Montini Theresa , Bryan-Jones Katherine , Mangurian Christina
Published: July 2002

OBJECTIVE

To study the role of science related and other arguments in the development of workplace smoking regulations.

DESIGN

Case study, content analysis

SUBJECTS

Written commentaries and hearing transcripts on proposed indoor air regulations in Maryland and Washington.

MAIN OUTCOME MEASURES

We coded each written commentary and hearing testimony for position toward the regulation, affiliation of the person submitting it, criteria used to evaluate science and scientific, ideological, economic, political, engineering and procedural arguments.

RESULTS

In both states, opposition to the regulations came primarily from the tobacco industry, small businesses, and business organisations and appeared to be coordinated. There was little coordination of public health support for the regulations. Arguments about science were used more often by those opposed to the regulations than by those in favour. Supporters emphasised the quantity of the evidence, while opponents criticised its reliability, validity, and quality. Arguments not related to science (61% of total arguments; 459/751), were more common than scientific arguments (39% of total arguments; 292/751). Economic and ideological arguments were used to a similar extent by regulation supporters and opponents.

CONCLUSIONS

Advocates can support health related regulations by submitting commentary emphasising the sound research base for regulation and countering criticisms of research. National coordination of these efforts could avoid duplication of effort and make more efficient use of limited public health resources.
Web sites selling cigarettes: how many are there in the USA and what are their sales practices?
Authors: Ribisl Kurt M , Kim Annice E , Williams Rebecca S
Published: July 2002

OBJECTIVES

To estimate the number and geographic location of web sites selling cigarettes in the USA, and to examine their sales and marketing practices.

METHODS

Comprehensive searches were conducted using four keyword terms and five popular internet search engines, supplemented by sites identified in a news article. Over 1800 sites were examined to identify 88 internet cigarette vendors.

MEASURES

Trained raters examined the content of each site using a standardised coding instrument to assess geographic location, presence of warnings, products sold, and promotional strategies.

SETTING

USA.

RESULTS

Internet cigarette vendors were located in 23 states. Nearly half (n = 43) were located in New York state, and many were in tobacco producing states with low cigarette excise taxes. Indian reservations housed 49 of the 88 sites. Only 28.4% of sites featured the US Surgeon General's health warnings and 81.8% featured minimum age of sale warnings. Nearly all sites (96.6%) sold premium or value brand cigarettes, 21.6% sold duty-free Marlboros, and 8.0% sold bidis. Approximately one third featured special promotional programmes.

CONCLUSIONS

Internet cigarette vendors present new regulatory and enforcement challenges for tobacco control advocates because of the difficulty in regulating internet content and because many vendors are on Indian reservations.
Structural behavior of cable anchorage zones in prestressed concrete cable-stayed bridge
Authors: Jo Byung-Wan , Byun Yunn-Ju , Tae Ghi-Ho
Published: July 2002

Since the cable anchorage zone in a prestressed concrete cable-stayed bridge is subjected to a large amount of concentrated tendon force, it shows very complicated stress distributions which can cause serious local cracks. Accordingly, it is necessary to investigate the parameters affecting the stress distribution, such as the cable inclination, the position of the anchor plate, the modeling method, and three-dimensional effects. The tensile stress distribution in the anchorage zone is compared to the actual design condition by varing the stiffness of spring elements in the local modeling, and an appropriate position for the anchor plate is determined. The results provide elementary data for the stress state in the anchorage zones and encourage more efficient designs.Key words: finite element analysis, bursting stress, spalling stress, cable anchorage zone, cable-stayed bridge.
Important structural features of 15-residue lactoferricin derivatives and methods for improvement of antimicrobial activity
Authors: Strøm Morten B , Haug Bengt Erik , Rekdal Øystein , Skar Merete L , Stensen Wenche , Svendsen John S
Published: July 2002

This review focuses on important structural features affecting the antimicrobial activity of 15-residue derivatives of lactoferricins. Our investigations are based on an alanine-scan of a 15-residue bovine lactoferricin derivative that revealed the absolute necessity of two tryptophan residues for antimicrobial activity. This "tryptophan-effect" was further explored in homologous derivatives of human, caprine, and porcine lactoferricins by the incorporation of one additional tryptophan residue, and by increasing the content of tryptophan in the bovine derivative to five residues. Most of the resulting peptides display a substantial increase in antimicrobial activity. To identify which molecular properties make tryptophan so effective, a series of bovine lactoferricin derivatives were prepared containing non-encoded unnatural aromatic amino acids, which represented various aspects of the physicochemical nature of tryptophan. The results clearly demonstrate that tryptophan is not unique since most of the modified peptides were of higher antimicrobial potency than the native peptide. The size and three-dimensional shape of the inserted "super-tryptophans" are the most important determinants for the high antimicrobial activity of the modified peptides. This review also describes the use of a "soft-modeling" approach in order to identify important structural parameters affecting the antimicrobial activity of modified 15-residue murine lactoferricin derivatives. This QSAR-study revealed that the net charge, charge asymmetry, and micelle affinity of the peptides were the most important structural parameters affecting their antimicrobial activity.Key words: antimicrobial peptides, lactoferricin, non-encoded aromatic amino acids, tryptophan.
Case study of a relict iceberg scour exposed at Scarborough Bluffs, Toronto, Ontario: implications for pipeline engineering
Authors: Eden David J , Eyles Nicholas
Published: July 2002

Ice scour is a common process on high latitude shelves and has been studied extensively though laboratory and numerical modelling. Direct observations of ice scours in outcrop are very rare. This paper describes a Late Pleistocene iceberg scour observable in soil cliff exposures at Cudia Park, Scarborough Bluffs, Toronto, Ontario. The structure is cut into a glaciolacustrine clayey silt, is about 10 m wide and 4 m deep, and is filled with sands deposited in shallow water. A description of the scour and a simplified finite element model of sub-ice scour soil deformation are presented. It is estimated that the Cudia scour was caused by a small iceberg with a mass of 0.04 Mt, in a water depth between 10 and 30 m, acting with a downward force of 5 MN, which is consistent with modern iceberg scours. The relevance of the Cudia scour to pipeline engineering (design burial depths) is demonstrated, with reference to the design methodology of the Centre for Cold Ocean Research and Engineering (C-CORE). The Cudia scour provides an additional outcrop example of a subscour bearing capacity-type failure and is the only outcrop example to date with lateral berm piles, which are a characteristic part of modern iceberg scours.Key words: iceberg scour, Scarborough Bluffs, pipeline engineering, finite element modelling, Pleistocene geology.
Characterization oftdtgenes for the degradation of tricyclic diterpenes byPseudomonas diterpeniphilaA19-6a
Authors: Morgan C A , Wyndham R C
Published: July 2002

Resin acids are tricyclic diterpenes that are toxic to aquatic life when released in high concentrations in pulp mill effluents. These naturally formed organic acids are readily degraded by bacteria and fungi; nevertheless, many of the mechanisms involved are still unknown. We report the localization, cloning, and sequencing of genes for abietane degradation (9.18 kb; designated tdt (tricyclic diterpene) LRSABCD) from the γ-Proteobacterium Pseudomonas diterpeniphila A19-6a. Using gene knockout mutants, we demonstrate that tdtL, encoding a putative CoA ligase, is required for growth on abietic and dehydroabietic acids. A second gene knockout in tdtD, encoding a putative cytochrome P450 monooxygenase, reduced the growth of strain A19-6a on abietic and dehydroabietic acids as sole sources of carbon and energy, but did not eliminate growth. The degree of homology between P450TdtDand P450TerpC, the closest known P450 homologue to TdtD, identifies TdtD as a new member of the P450 superfamily. Hybridization of six of the tdt genes to genomic DNA of a related resin acid degrading bacterium Pseudomonas abietaniphila BKME-9 identified tdt homologues in this strain that utilizes aromatic ring dioxygenase genes (dit) to open the ring structure of abietic and dehydroabietic acids. These results suggest the tdt and dit genes may function in concert to allow these Pseudomonas strains to degrade resin acids. Homologues of several of the tdt genes were detected in resin acid degrading Ralstonia and Comamonas species within the β- and γ-Proteobacteria.Key words: resin acid, tdt gene, biodegradation, Pseudomonas.
Does local feeding specialization exist in Eurasian badgers?
Authors: Revilla Eloy , Palomares Francisco
Published: July 2002

Several local populations of the otherwise trophic-generalist Eurasian badger (Meles meles) have been defined as specializing locally on temporally variable food resources such as earthworms (Lumbricus spp.), olive fruits (Olea europaea), or young rabbits (Oryctolagus cuniculus), owing to a lack of correlation between resource availability and use. However, theoretical models predict that temporal variation in resources reduces the probability of diet specialization. To understand the relationship between temporal resource variability and local feeding specialization, we studied temporal variation in diet composition and diversity (using fecal analysis), the availability of a temporally stable key resource, and the relation between consumption and availability of rabbits (key prey) and invertebrates (secondary prey) for a badger population previously described as specialized on young rabbits. We found strong variations in the use of different resources (including young rabbits) and in diet diversity among seasons and years. The main food resource was young rabbits during winter and spring, fruits in autumn, and reptiles in summer. Diet diversity was inversely related to consumption of young rabbits and directly related to consumption of secondary prey (invertebrates). Consumption of rabbits (both young and adults) was correlated with their abundance in the field, with a type 3 functional response in the consumption of young rabbits, which is typical of a generalist to whom alternative prey are available. There was no relationship between the abundance of invertebrates and their consumption. Our results show that badgers in the study area were not locally specialized, therefore care should be taken when referring to a population as specialized without an adequate test of the predictions.
LAMBDA-REPRESENTABLE FUNCTIONS OVER TERM ALGEBRAS
Authors: TAKAHASHI MASAKO
Published: July 2002

In this paper, we study λ→-representability of functions over (open or closed) term algebras. First, by extending the standard notion of λ→-representation of closed (or variable-free) terms to open terms and extending the notion of λ→-representable functions accordingly, we give a recursion-theoretic characterization of the class of λ→-representable functions over open term algebras. Then, based on this result, we obtain two characterizations of the class of λ→-representable functions over closed term algebras (i.e., free structures). As a related topic, in the Appendix we give a simple formulation of the recursive word functions, and study their properties in relation to recursive functions on natural numbers and type-free pure λ-calculus.
PARALLEL MAXIMUM MATCHING ALGORITHMS IN INTERVAL GRAPHS
Authors: CHUNG YOOJIN , PARK KUNSOO , CHO YOOKIN
Published: July 2002

We develop efficient parallel maximum matching algorithms in interval graphs by exploiting special properties of interval graphs. For general interval graphs, our algorithm requires O( log 2v+(n log n/v) time and O(nv2+n2) operations on the CREW PRAM, where n is the number of intervals and v≤n is a parameter. By choosing [Formula: see text], we obtain an [Formula: see text]-time algorithm in O(n2) operations. For v=n/ log n, we have an O( log 2n)-time algorithm in O(n3/ log 2n) operations. The best previously known solution takes O( log 2n) time using O(n3 log 2n) operations. For proper interval graphs, our algorithm runs in O( log n) time using O(n) operations if input intervals are sorted and using O(n log n) operations otherwise on the EREW PRAM.
GLAUBER DYNAMICS FOR QUANTUM LATTICE SYSTEMS
Authors: ALBEVERIO S. , KONDRATIEV YU. G. , RÖCKNER M. , TSIKALENKO T. V.
Published: July 2002

Models of quantum mechanical anharmonic lattice systems ("anharmonic crystals") are described. Temperature quantum Gibbs states are represented by classical Gibbs measures for lattice systems of loop-valued spin variables. These Gibbs measures are also obtained as invariant (equilibrium) measures of a system of stochastic differential equations ("stochastic dynamics", "stochastic quantization"). Existence and uniqueness results for these equations are established and a construction of the solution via a finite volume approximation is given. The Markov property of this solution is also exhibited and properties of the Gibbs distributions (existence, a prioiri estimates, regularity of support) are characterized in terms of the stochastic dynamics. Ergodicity and uniqueness of the Gibbs distributions are also discussed.
SOLITARY WAVES OF THE NONLINEAR KLEIN-GORDON EQUATION COUPLED WITH THE MAXWELL EQUATIONS
Authors: BENCI VIERI , FORTUNATO DONATO FORTUNATO
Published: July 2002

This paper is divided in two parts. In the first part we construct a model which describes solitary waves of the nonlinear Klein-Gordon equation interacting with the electromagnetic field. In the second part we study the electrostatic case. We prove the existence of infinitely many pairs (ψ, E), where ψ is a solitary wave for the nonlinear Klein-Gordon equation and E is the electric field related to ψ.
GAUGE TRANSFORMATIONS AND RECIPROCAL LINKS IN 2 + 1 DIMENSIONS
Authors: OEVEL W. , ROGERS C.
Published: July 2002

Generalized Lax equations are considered in the spirit of Sato theory. Three decompositions of an underlying algebra of pseudo-differential operators lead, in turn, to three different classes of integrable nonlinear hierarchies. These are associated with Kadomtsev-Petviashvili, modified Kadomtsev-Petviashvili and Dym hierarchies in 2 + 1 dimensions. Miura- and auto-Bäcklund transformations are shown to originate naturally from gauge transformations of the Lax operators. General statements on reciprocal links between these hierarchies are established, which, in particular, give rise to novel reciprocal auto-Bäcklund transformations for the Dym hierarchy. These links are formulated as Darboux theorems for the associated Lax operators.
Entropy Density of One-Dimensional Quantum Lattice Systems
Authors: Moriya Hajime
Published: July 2002

We prove that the entropy density of a KMS state of one-dimensional quantum lattice systems is equal to the thermodynamical limit of the entropy of local Gibbs states.
MULTIPLE BASE SUBSTITUTION CORRECTIONS IN DNA SEQUENCE EVOLUTION
Authors: KOWALCZUK M. , MACKIEWICZ P. , SZCZEPANIK D. , NOWICKA A. , DUDKIEWICZ M. , DUDEK M. R. , CEBRAT S.
Published: July 2002

We discuss the Jukes and Cantor's one-parameter model and Kimura's two-parameter model unability to describe evolution of asymmetric DNA molecules. The standard distance measure between two DNA sequences, which is the number of substitutions per site, should include the effect of multiple base substitutions separately for each type of the base. Otherwise, the respective tables of substitutions cannot reconstruct the asymmetric DNA molecule with respect to the composition. Basing on Kimura's neutral theory, we have derived a linear law for the correlation of the mean survival time of nucleotides under constant mutation pressure and their fraction in the genome. According to the law, the corrections to Kimura's theory have been discussed to describe evolution of genomes with asymmetric nucleotide composition.

We consider the particular case of the strongly asymmetric Borrelia burgdorferi genome and we discuss in detail the corrections, which should be introduced into the distance measure between two DNA sequences to include multiple base substitutions.
IS MERITOCRACY OUTMODED IN A KNOWLEDGE-BASED ECONOMY?
Authors: APPOLD STEPHEN J.
Published: July 2002

Singapore prides itself on its system of meritocracy that is meant to channel the most capable individuals to the most critical positions. Performance in school, buttressed by a system of university scholarships, identifies potential stars early on. Scholars are often carefully groomed in the early years of their working careers and screened further. Only the best reach positions of real responsibility. Such a system worked well in the past and some researchers have held the meritocratic stratification system at least partially responsible for Singapore's economic growth (and that of some other Asian countries). The meritocratic system, however, is not well-suited to the exigencies of knowledge-based economies; these require a broad base of committed workers each with a high level of skill. As tasks and needs rapidly shift, so may job performance. Building on information gathered from Singaporean workplaces and on theories of internal labor markets, this paper will identify how a meritocratic stratification system limits overall job performance by producing only a small number of committed workers. This paper will illustrate how a stratification system capable of motivating a larger number of workers would work and discuss adaptation issues.
A NOTE ON NONCOMMUTATIVE CHERN–SIMONS MODEL ON MANIFOLDS WITH BOUNDARY
Authors: LUGO ADRIÁN R.
Published: July 2002

We study field theories defined in regions of the spatial noncommutative (NC) plane with a boundary present delimiting them, concentrating in particular on the U(1) NC Chern–Simons theory on the upper half-plane. We find that classical consistency and gauge invariance lead necessary to the introduction of K0-space of square integrable functions null together with all their derivatives at the origin. Furthermore the requirement of closure of K0 under the *-product leads to the introduction of a novel notion of the *-product itself in regions where a boundary is present, that in turn yields the complexification of the gauge group and to consider chiral waves in one sense or other. The canonical quantization of the theory is sketched identifying the physical states and the physical operators. These last ones include ordinary NC Wilson lines starting and ending on the boundary that yield correlation functions depending on points on the one-dimensional boundary. We finally extend the definition of the *-product to a strip and comment on possible relevance of these results to finite quantum Hall systems.
COMMENTS ON D-BRANES ON GENERAL GROUP MANIFOLDS
Authors: MICHISHITA YOJI
Published: July 2002

We investigate D-branes with maximal symmetry on general group manifolds in terms of boundary states and effective actions. We show that in large k limit boundary states with a suitable Wilson line form boundary states of the other types of D-branes, extending the known fact in SU(2) case. We also show that fluctuation mass spectrum around D-brane solutions of the effective action agrees with that of boundary CFT in large k limit.
Spin(p + 1, p + 1) COVARIANT Dp-BRANE BOUND STATES
Authors: SUNDELL P.
Published: July 2002

We construct Spin (p + 1, p + 1) covariant D p-brane bound states by using the fact that the potentials in the RR sector of toroidically compactified type II supergravity transform as a chiral spinor of the T duality group. As an application, we show the invariance of the zero-force condition for a probe D-brane under noncommutative deformations of the background, which gives a holographic proof of the stability of the corresponding field theory ground state under noncommutative deformations. We also identify the Spin (p + 1, p + 1) transformation laws by examining the covariance of the D-brane Lagrangians.
CONVERGENCE OF DERIVATIVE EXPANSIONS IN SCALAR FIELD THEORY
Authors: MORRIS TIM R. , TIGHE JOHN F.
Published: July 2002

The convergence of the derivative expansion of the exact renormalisation group is investigated via the computation of the β function of massless scalar λφ4 theory. The derivative expansion of the Polchinski flow equation converges at one loop for certain fast falling smooth cutoffs. Convergence of the derivative expansion of the Legendre flow equation is trivial at one loop, but also can occur at two loops and in particular converges for an exponential cutoff.
SCHRÖDINGER EQUATION FOR QUANTUM FRACTAL SPACE–TIME OF ORDER n VIA THE COMPLEX-VALUED FRACTIONAL BROWNIAN MOTION
Authors: JUMARIE GUY
Published: July 2002

First remark: Feynman's discovery in accordance of which quantum trajectories are of fractal nature (continuous everywhere but nowhere differentiable) suggests describing the dynamics of such systems by explicitly introducing the Brownian motion of fractional order in their equations. The second remark is that, apparently, it is only in the complex plane that the Brownian motion of fractional order with independent increments can be generated, by using random walks defined with the complex roots of the unity; in such a manner that, as a result, the use of complex variables would be compulsory to describe quantum systems. Here one proposes a very simple set of axioms in order to expand the consequences of these remarks. Loosely speaking, a one-dimensional system with real-valued coordinate is in fact the average observation of a one-dimensional system with complex-valued coordinate: It is a strip modeling. Assuming that the system is governed by a stochastic differential equation driven by a complex valued fractional Brownian of order n, one can then obtain the explicit expression of the corresponding covariant stochastic derivative with respect to time, whereby we switch to the extension of Lagrangian mechanics. One can then derive a Schrödinger equation of order n in quite a direct way. The extension to relativistic quantum mechanics is outlined, and a generalized Klein–Gordon equation of order n is obtained. As a by-product, one so obtains a new proof of the Schrödinger equation.
SUPER-RADIANCE AND THE UNSTABLE PHOTON OSCILLATOR
Authors: SIVASUBRAMANIAN S. , WIDOM A. , SRIVASTAVA Y. N.
Published: July 2002

If the damping of a simple harmonic oscillator from a thermally random force is sufficiently strong, then the oscillator may become unstable. For a photon oscillator (radiatively damped by electric dipole moments), the instability leads to a low temperature Hepp–Lieb–Preparata super-radiant phase transition. The stable oscillator regime is described by the free energy of the conventional Casimir effect. The unstable (strongly damped) oscillator has a free energy corresponding to Dicke super-radiance.
A Parallel Algorithm for Conserving Approximation of Lattice Models Having Both Interactions and Disorder
Authors: Buhrow B. , Deisz J. J.
Published: July 2002

We present a parallel algorithm for numerical calculations for electronic lattice models with interactions and disorder. In this scheme, diagonal and off-diagonal disorder are treated exactly per disorder configuration and interaction effects are evaluated using conserving approximations based on self-consistent perturbation theory. We demonstrate this method by calculating second-order corrections to the local pairing amplitude and specific heat for the attractive Hubbard model.
RETRIEVED ANISOTROPY OF ONE-DIMENSIONAL CRYSTAL PIPERIDINIUM TRIBLOMOPLUMBATE
Authors: AZUMA JUNPEI , TANAKA KOICHIRO
Published: July 2002

Polarization characteristics of luminescence in one-dimensional crystal piperidinium tribromoplumbate has been investigated to clarify the relaxed photo-excited states of this system. It has been observed that the emission band with non-exponential decay is almost depolarized at 10 K but becomes polarized drastically parallel to the chain as temerature is raised above 15 K. This indicates that anisotropy of the initial state of luminescence retrieved thermally. Electron spin resonance (ESR) technique has been applied to identify photo-induced defects. A hole center formed by several bromine ions has been observed. The initial state of this emission band is discussed from the retrieved anisotropy and the ESR measurements.
Synthesis and Properties of Novel Magnetorheological Fluids Having Improved Stability and Redispersibility
Authors: Phulé Pradeep P. , Ginder John M.
Published: July 2002

A novel class of relatively stable and redispersible MR fluids based on meso-scale magnetic particles of iron or nickel zinc ferrite and nano-scale additives is described. For a flux density B ~ 1 Tesla, the iron based MR fluids exhibited yield stresses of ~100 kPa. For ferrite based fluids the yield stress values were as high as ~15 kPa at B ~ 1T. The yield stresses at the flux density required for magnetic saturation increase quadratically with the saturation magnetization of the particulate material, in good agreement with a model for the yield stress of uniformly saturated particle chains. At lower flux densities, the yield stress was generally observed to increase as B 3/2, consistent with models of the role of local saturation of the particle magnetization. The additives were found to enhance the stability and redispersibility of the MR fluids: they appeared to promote a small non-zero yield stress in the absence of a field but were found not to have a substantial effect on the field-dependent yield stresses.
THEORY OF HIGH-Tc SUPERCONDUCTING CUPRATES BASED ON EXPERIMENTAL EVIDENCE
Authors: ABRIKOSOV A. A.
Published: July 2002

A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T c , features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
TRANSITION FROM HEAVY FERMION METAL TO 16 K SUPERCONDUCTOR IN SINGLE CRYSTAL YbxLu(1-x)Ni2B2C: TRANSPORT STUDIES
Authors: RATHNAYAKA K. D. D. , NAUGLE D. G. , LI SHI , de ANDRADE M. C. , DICKEY R. P. , AMANN A. , MAPLE M. B. , BUD'KO S. L. , CANFIELD P. C. , BEYERMANN W. P.
Published: July 2002

YbNi 2 B 2 C has been found to be a heavy fermion metal with neither superconductivity nor magnetic order in contrast to the other members of the borocarbide family. LuNi 2 B 2 C is a superconductor with T c~ 16.3 K and no magnetic order. Transport studies on single crystal Yb x Lu (1-x) Ni 2 B 2 C show a systematic change from a heavy fermion system to a moderately high-temperature superconductor. A "giant" thermopower is observed for small x to x =1, i.e., in the transition region from a Kondo alloy to a heavy fermion metal. Measurements of H c2( T, x ) are also reported for x <0.15.
THOMPSON'S METHOD APPLIED TO DIFFUSION LIMITED CHEMICAL REACTION A+B→0, WITH DIFFERENT INITIAL CONCENTRATIONS OF THE TWO SPECIES
Authors: NASSIF CLÁUDIO , SILVA P. R.
Published: July 2002

In this work we use Thompson's renormalization group method to treat diffusion limited chemical reactions A + B →0 (inert product), with unequal initial concentrations of the two species, by considering ρ A (0)≪ρ B (0). For d≤2, we obtain stretched exponential decaying of the specie A, which is in agreement with rigorous result of Bramson and Lebowitz. For d>2, we obtain simple exponential decaying of the specie A.
ESR STUDIES ON GMR RELATED MATERIALS IV: ESR OF Mn IN La0.7Ca0.3MnO3
Authors: SUGAWARA K. , ARAI N. , KOUZUKI A. , HOTTA K. , HIROSE H. , CHU C. W.
Published: July 2002

ESR measurements have been carried out on La 0.7 Ca 0.3 MnO 3. Distorted signals have been observed below about 255 K, but clear signals above ≃ 270 K . The temperature dependence of the low-temperature ESR linewidth nearly follows the magnetization (or susceptibility). The ESR intensity exhibits an anomalous increase at temperatures between about 200 K and 260 K with a peak at around 250 K; quite similar behavior to that of the resistivity, indicating a possible correlation between the resistivity and the ESR intensity. The temperature dependence of the ESR linewidth and intensity has been also studied above 300 K.
CURRENT-VOLTAGE CHARACTERIZATION OF ALKANETHIOL SELF-ASSEMBLED MONOLAYERS IN METAL NANOWIRES
Authors: KRATOCHVÍLOVÁ IRENA , ZAMBOVA ADRIANA , MBINDYO JEREMIAH , RAZAVI BAHARAK , HOLAKOVSKÝ JOSEF
Published: July 2002

An electric-field assisted assembly has been used to place rod-shaped, metal-organic, molecule-metal nanowires onto lithographically defined metal pads allowing the electrical characterization of metal-molecule self-assembled monolayer-metal containing nanowires. Our results show that the parameters of metal-molecule metal junctions are close to previously published data, so we have constructed systems containing insulating monolayers with reasonable properties.
Pseudogap Formation in CeNiSn
Authors: Xiao-Bing Feng
Published: July 2002

Using Green's function decoupling method the single particle excitation spectrum of the periodic Anderson model is studied. With increasing hybridization potential in the Kondo regime there appear pseudogaps in the excitation spectrum of the two kinds of carriers. The temperature dependence of the pseudogaps is qualitatively in accordance with tunneling experiments on CeNiSn.
CLUSTERING USING SIMULATED ANNEALING WITH PROBABILISTIC REDISTRIBUTION
Authors: BANDYOPADHYAY SANGHAMITRA , MAULIK UJJWAL , PAKHIRA MALAY KUMAR
Published: July 2002

An efficient partitional clustering technique, called SAKM-clustering, that integrates the power of simulated annealing for obtaining minimum energy configuration, and the searching capability of K-means algorithm is proposed in this article. The clustering methodology is used to search for appropriate clusters in multidimensional feature space such that a similarity metric of the resulting clusters is optimized. Data points are redistributed among the clusters probabilistically, so that points that are farther away from the cluster center have higher probabilities of migrating to other clusters than those which are closer to it. The superiority of the SAKM-clustering algorithm over the widely used K-means algorithm is extensively demonstrated for artificial and real life data sets.
AUTOMATIC DETECTION AND VERIFICATION OF TEXT REGIONS IN NEWS VIDEO FRAMES
Authors: HU JIANMING , XI JIE , WU LIDE
Published: July 2002

Textual information in a video is very useful for video indexing and retrieving. Detecting text blocks in video frames is the first important procedure for extracting the textual information. Automatic text location is a very difficult problem due to the large variety of character styles and the complex backgrounds.

In this paper, we describe the various steps of the proposed text detection algorithm. First, the gray scale edges are detected and smoothed horizontally. Second, the edge image is binarized, and run length analysis is applied to find candidate text blocks. Finally, each detected block is verified by an improved logical level technique (ILLT). Experiments show this method is not sensitive to color/texture changes of the characters, and can be used to detect text lines in news videos effectively.
SELF-EXCITING FARADAY DISK HOMOPOLAR DYNAMOS
Authors: MOROZ IRENE M.
Published: July 2002

In this paper we present an overview of recently published work on the Faraday disk self-exciting homopolar dynamos. We also extend the analysis of two such coupled self-exciting disk dynamos with linear series motors [Moroz et al., 1998a; Moroz et al., 1998b] to the situation where one or both dynamo subunits incorporate nonlinear motors. We examine the differences in some of the bifurcation transition sequences between the various cases and consider whether the nonlinear quenching of oscillatory solutions can occur [Hide, 1998].
NO DIVISION AND THE ENTROPY OF TREE MAPS
Authors: YE XIANGDONG
Published: July 2002

Let T be a tree, End (T) be the number of ends of T and f:T→ T be continuous. We show that if f has a nondivisible periodic orbit or a nontwist periodic orbit then the topological entropy of f is larger than or equal to (1/ End (T)) log 2. By constructing examples we also show that the estimate is the best one.
RELIABLE SOLUTION OF A TORSION PROBLEM IN HENCKY PLASTICITY WITH UNCERTAIN YIELD FUNCTION
Authors: HLAVÁČEK IVAN
Published: July 2002

The worst scenario method is applied to the torsion problem of a homogeneous orthotropic elasto-plastic bar with uncertain yield function. According to the Haar–Kármán principle, the problem leads to a minimization of the complementary energy over a convex set of admissible stresses. The latter set is determined by a yield function with uncertain coefficients. We formulate two maximization problems with respect to the set of admissible coefficients, prove the solvability of the corresponding continuous and approximate problems, and discuss the convergence of some sequences of finite-element approximations.
"ETERNAL" SOLUTIONS FOR A MODEL OF THE BOLTZMANN EQUATION
Authors: CABANNES HENRI
Published: July 2002

This paper deals with the analysis of the so-called "eternal" solutions to the Cauchy problem for a semidiscrete plane model of the Boltzmann equation. By eternal solutions we mean solutions existing globally for both positive and negative values of time.
A COMPARISON OF THE ROLES OF LOCALISED AND NONLOCALISED GROWTH FACTORS IN SOLID TUMOUR GROWTH
Authors: BYRNE HELEN M.
Published: July 2002

Recent experimental results suggest that during proliferation, tumour cells express growth factors that modify their growth dynamics. In this paper we extend the standard model of avascular tumour growth to study the effect that two types of growth factors (localised or nondiffusible and diffusible) can have on the tumour's development. In both cases we assume that the growth factor is produced in inactive form and becomes activated when it binds to a tumour cell. We show how the inclusion into the model of such GFs endows the tumour with history dependence, in that its evolution depends not only on its structure at a given instant but also on its structure at earlier times. We also present numerical simulations to illustrate the various ways in which the two types of growth factors affect the tumours' growth dynamics. The physical implications of the results are discussed briefly and several experiments are suggested which could be performed to validate the model hypotheses and results.
ON A QUESTION OF DEHORNOY CONCERNING BRAIDS
Authors: Fenn Roger , Ibáñez-Varela Raúl
Published: July 2002

In this paper we will prove that the answer to the following question proposed by Patric Dehornoy [3] is affirmative. Let β be a braid in Bn such that sh(β-1)σ1sh(β) belongs to Bn, where sh : Bn→Bn+1 is the shift operator. Does β belong necessarily to sh(Bn-1)·Bn-1?
HIGHER DIMENSIONAL CHARGED NULL FLUID COLLAPSE AND COSMIC CENSORSHIP
Authors: GHOSH S. G. , SARAYKAR R. V.
Published: July 2002

We analyze here the spherically symmetric collapse of a charged null fluid in a higher dimensional spacetime. Both naked singularities and black holes are shown to be developing as final outcome of the collapse. A relationship between weak energy condition and occurrence of strong curvature singularity is pointed out.
ANISOTROPIC HOMOGENEOUS UNIVERSES IN THE VARYING SPEED OF LIGHT THEORY
Authors: HARKO T. , MAK M. K.
Published: July 2002

The evolution and dynamics of Bianchi type I and V Universes is considered in the framework of the varying speed of light theory. Einstein's field equations with a variable speed of light c=c(t), gravitational coupling G=G(t) and decaying vacuum energy density Λ=Λ(t) are considered as describing matter creation in a cosmological framework. The particle creation rate is uniquely determined by the variation rates of c, and G and Λ. By considering simple phenomenological evolution laws for the "constants," exact analytical and numerical solutions of the gravitational field equations are obtained, leading to a self-consistent cosmological model describing matter and entropy generation in anisotropic Universes. In the limit of large times the mean anisotropy tends to zero, thus the time variation of the fundamental constants providing an effective mechanism for the isotropization of the Universe.
SOME FRACTAL CHARACTERS OF POROUS MEDIA
Authors: YU BOMING , LI JIANHUA
Published: July 2002

In this paper, a unified model for describing the fractal characters of porous media is deduced. The theoretical predictions from the proposed unified model are compared with those from the previous models and from the box-counting method. The results from the proposed model are found to be in good agreement with both the previous models and box-counting method. The results also indicate that the proposed unified model is applicable to both the exactly and statistically self-similar fractal media. A statistical property of porous media is also described based on the basic fractal theory and technique. A criterion, for determining whether a porous medium can be characterized by fractal theory and technique or not, is proposed based on the fractal statistical property.