bluuebunny/crossref_metadata_2025 huggingface dataset:
What We Owe Our Children, They Their Children, …
Authors: Roemer John E. , Veneziani Roberto
Published: November 2004

Egalitarian theorists, since Rawls, have in the main advocated equalizing some objective measure of individual well‐being, such as primary goods, functionings, or resources, rather than subjective welfare. This discussion, however, has assumed, implicitly, a static environment. By analyzing a society that survives for many generations, we demonstrate that equality of opportunity for some objective condition is incompatible with human development over time. We argue that this incompatibility can be resolved by equalizing opportunities for welfare. Thus, “subjectivism” seems necessary if we are to hope for a society that can both equalize opportunities and support the development of human capacity over time.
Politically Determined Income Inequality and the Provision of Public Goods
Authors: Olszewski Wojciech , Rosenthal Howard
Published: November 2004

Political processes may bring about Pareto improvements by increasing income inequality in a society that produces a public good by voluntary contributions. Proportional taxation funds a “governing agent.” The most endowed agent is the Condorcet winner for governing agent. When the tax rate can also be chosen by a vote, the ideal point of the agent with median initial endowment is the Condorcet winner under Cobb–Douglas utility. If Pareto improvements are possible, this ideal point corresponds to Pareto improvement. Pareto improvement may also be possible, even when a Leviathan set taxes, if there is deadweight loss from taxation. Pareto improvements are indeed always possible in “large” societies. On the other hand, no improvements may be possible if the initial distribution of wealth is very unequal in a “small” society, and Condorcet winners may not exist for other utility functions.
Decreased aortic smooth muscle contraction in a rat model of multibacterial sepsis
Authors: Wang Changhua , Mansard Arnaud , Giummelly Philippe , Atkinson Jeffrey
Published: November 2004

We investigated whether blockade of the smooth muscle cell (SMC) inducible nitric oxide synthase (iNOS)–soluble guanylyl cyclase (sGC) vasodilator pathway would restore the fall in vasoreactivity produced by sepsis following cecal ligation and perforation (CLP) in rats. Contraction of adjacent aortic rings paired for the presence or absence of endothelial cells (EC) was recorded following high [K+]e (40 mm) or norepinephrine (NE, 10−8 to 10−5 m) in the presence of the nitric oxide synthase inhibitor (NOS), NG‐nitro‐l‐arginine methyl ester (l‐NAME, 0.3 mm) or the sGC inhibitor, 1H‐[1,2,4]oxadiazolo[4,3‐alpha]quinoxalin‐1‐one (ODQ, 5 μm). In EC‐denuded rings, sepsis halved SMC contraction induced by high [K+]e or NE; neither l‐NAME nor ODQ produced an increase in NE Emax or high [K+]e‐evoked contraction. In conclusion, SMC contractility is globally reduced in CLP; this reduction does not appear to be explained by induction of SMC NOS in this CLP model.
A 10‐year follow‐up study of pulmonary function in symptomatic elite cross‐country skiers – athletes and bronchial dysfunctions
Authors: Vergès Samuel , Flore Patrice , Blanchi Marie‐Philippe Rousseau , Wuyam Bernard
Published: November 2004

A high prevalence of asthma‐like symptoms and abnormal bronchial reactivity to various stimuli has been reported among endurance athletes. This report presents the cases of three cross‐country skiers who have shown a progressive development of airway obstruction during their sport careers. The observed decline in FEV1, FEV1/FVC and/or FVC (FEV, forced expiratory volume; FVC, forced expiratory vital capacity) was greater than expected from longitudinal regression equations describing the ageing effect on pulmonary function. The three subjects encountered abnormal respiratory discomfort during their sport activity which was not systematically associated with abnormal bronchial reactivity (either to methacholine or exercise hyperventilation). At the end of the follow‐up periods (9–12 years), all three skiers presented objective signs of airflow limitations during intense exercise. This report suggests that repeated chronic hyperventilation of cold dry air in cross‐country skiers for several years can induce permanent bronchial disorders which may include remodeling processes and induce ventilatory limitations during intense exercise.
Effects of adding luteinizing hormone to a medium containing follicle stimulating hormone on progesterone‐induced differentiation of cumulus cells during meiotic resumption of porcine oocytes
Authors: SHIMADA Masayuki , NISHIBORI Masahide , YAMASHITA Yasuhisa
Published: November 2004

In the present study, we investigated the effects of adding luteinizing hormone (LH) to a medium containing follicle stimulating hormone (FSH) on the shift in expression of progesterone receptor (PR) isoforms (PR‐A and PR‐B) and the roles in function of cumulus cells of cumulus‐oocyte complexes (COC). The level of PR‐B mRNA in cumulus cells was up‐regulated by FSH during the first 16‐h cultivation but the level was significantly decreased at 20 h. The decrease of PR‐B mRNA was accelerated when COC were cultured with FSH and LH. Still, a high level of total PR mRNA was maintained in cumulus cells cultured with or without the addition of LH up to 20 h, suggesting that the expression of PR isoforms was shifted from PR‐B to PR‐A in cumulus cells. The reduction of PR‐B was also induced by addition of progesterone to FSH‐containing medium. The addition of LH or progesterone to FSH‐containing medium stimulated cumulus expansion of COC as compared with that of COC cultured with FSH. In the expanded COC, ADAMTS‐1 which is expressed in granulosa cells and cumulus cells in rodent follicles through LH‐induced progesterone‐ and PR‐dependent pathway, was more accumulated within the COC matrix. These results suggest that the addition of LH or progesterone to FSH‐containing medium is required for the differentiation of cumulus cells, such as cumulus expansion, mediated by the shift from PR‐B to PR‐A in them.
Comparison of feed intake, digestibility and fattening performance of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)
Authors: LAPITAN Rosalina M. , DEL BARRIO Arnel N. , KATSUBE Osamu , TOKUDA Tomomi , ORDEN Edgar A. , ROBLES Alberto Y. , FUJIHARA Tsutomu , CRUZ Libertado C. , KANAI Yukio
Published: November 2004

Twenty growing crossbred cattle and crossbred water buffalo (carabao) with an average age of 22 (18–24 months) months were equally distributed into two treatment groups according to species. The animals were fed with the same ration made up of corn silage (50%) + wet brewer's spent grain (30%) + concentrate mixture (20%), and their fattening performance was monitored. The digestibilities of the different nutrients were likewise determined. The economics of raising the animals under intensive production system was calculated. Species differences did not influence total dry matter intake of the animals, when expressed as percentage of the bodyweight and per metabolic body size. There were no significant differences in digestion coefficients of the different nutrients, except for crude protein in crossbred water buffalo and crossbred cattle, although the digestibility of dry matter, organic matter and nitrogen free extract tended to be high in the former than in the latter. Likewise, average daily gain (ADG) was similar, although crossbred water buffalo had numerically higher ADG (828.6 vs 785.5 g) than crossbred cattle during the 6 months feeding. During the first 3 months of feeding (1–90 days), the ADG of crossbred water buffalo was 1066.1 g compared to 940.1 g for crossbred cattle. From 91 to 180 days, the crossbred cattle had slightly higher ADG (630.1 vs 591.1 g) but also the difference was not significant. The return above feed cost was comparable for crossbred cattle and crossbred water buffalo during the first 90 days of feeding. However, extending the feeding period from 91 to 180 days, income over feed cost was higher (P < 0.05) for crossbred cattle by PhP 5.3/kg gain than crossbred water buffalo. Results showed that crossbred water buffalo could attain similar growth rate with that of crossbred cattle under intensive system, when fed with high quality feed materials.
CONFORMAL TRANSFORMATIONS OF COMPACT SELF-DUAL MANIFOLDS
Authors: POON Y. S.
Published: November 2004

We prove that when the dimension of the group of conformal transformations of a compact self-dual manifold is at least three, the conformal class contains either a metric with positive constant scalar curvature or a metric with zero scalar curvature. This result is combined with a topological classification of 4-manifolds to provide a complete geometrical classification of the compact self-dual manifolds whose symmetry group is at least three-dimensional.
TOPOLOGICAL ENTROPY VERSUS GEODESIC ENTROPY
Authors: PATERNAIN GABRIEL P. , PATERNAIN MIGUEL
Published: November 2004

Using Yomdin's Theorem [8], we show that for a compact Riemannian manifold M, the geodesic entropy — defined as the exponential growth rate of the average number of geodesic segments between two points — is ≤ the topological entropy of the geodesic flow of M. We also show that if M is simply connected and N ⊂ M is a compact simply connected submanifold, then the exponential growth rate of the sequence given by the Betti numbers of the space of paths starting in N and ending in a fixed point of M, is bounded above by the topological entropy of the geodesic flow on the normal sphere bundle of N.
CLASSIFICATION OF GENERIC INTEGRAL DIAGRAMS AND FIRST ORDER ORDINARY DIFFERENTIAL EQUATIONS
Authors: HAYAKAWA A. , ISHIKAWA G. , IZUMIYA S. , YAMAGUCHI K.
Published: November 2004

In this paper we give local normal forms of generic implicit first order ordinary differential equations with independent first integrals. The classification problem in this case is reduced to classifying a certain class of divergent diagrams of map-germs; integral diagrams. The main tools are Legendre singularity theory and differential analysis. We also discuss the relation between previous works and the results obtained in this paper.
GROUPS WITH BOUNDED TRACE AND THE TRIVIAL CORTEX PROBLEM
Authors: SUND TERJE
Published: November 2004

It will be shown that a connected Lie group has bounded trace if and only if its component with no semisimple factors has a cocompact radical which is a direct product E × R where E denotes a finite direct product of groups of motion of the real plane (including covering groups) and R is a semidirect product of a torus and a nilpotent group with continuous trace. This leads to a complete description of the class of all connected Lie groups whose identity representation constitutes a separated point in the unitary dual ( Cor (G) = {1G}).
CHARACTERIZATION OF MODELS IN C2 BY THEIR AUTOMORPHISM GROUPS
Authors: BERTELOOT FRANÇOIS
Published: November 2004

Let Ω be a domain in C2. Assume that there exists a point z0 in Ω and a sequence (φp) of holomorphic automorphisms of Ω such that (φp (z0)) is accumulating at some point ζ0 where bΩ is pseudoconvex and finite type. We show that Ω is biholomorphically equivalent to its model at ζ0.
EXTENSION ALGEBRAS OF II1 FACTORS VIA *-ENDOMORPHISMS
Authors: CHODA MARIE
Published: November 2004

From the view of Jones index theory, we construct a III factor , for a pair {A, γ} of a II 1 factor A and a trace preserving *-endomorphism γ, through the method of the crossed product by a *-endomorphism. The AFD III λ factor M is isomorphic to  for a basic *-endomorphism σ of the hyperfinite II 1 factor A if and only if λ−1 ∈ {4 cos 2(π/n : n ≥ 3} ⋃ [4, ∞). Ocneanu's canonical shift Γ for an inclusion N ⊂ M of II 1-factors with [M: N] < ∞ is extended to a *-endomorphism [Formula: see text] of  for A = M′ ∩ M∞. The extended *-endomorphism [Formula: see text] is Longo's canonical *-endomorphism.
THE EMU MESSAGES DISPLAY FOR THE DELPHI EXPERIMENT AT LEP
Authors: ROVELLI TIZIANO
Published: November 2004

The DELPHI Data Acquisition and Control System uses the Error and Message handling Utility (EMU) as a standard distributed system which deals with messages generated by the controlling and monitoring processes. A tool which allows one to look at EMU messages as they are produced and to retrieve past messages is described. This utility, being based on a configuration file, can be used both by the central and individual detector operators. Versions exist with both MOTIF (X-windows) and MHI (“VT100”) user interfaces.
A TRANSIENT DYNAMIC CONTACT PROBLEM IN THREE DIMENSIONS
Authors: Fan T.Y. , Hahn H.G. , Voigt A.
Published: November 2004

In this study a three-dimensional transient dynamic contact problem is solved, and a theorem relating the contact stress and displacement over an elliptic region is proved. Numerical results for the contact displacement-time variation clearly demonstrate the effect of inertia induced by the dynamic stress.
A DETAILED DESCRIPTION OF CHEMICAL AND THERMAL NONEQUILIBRIUM IN HYPERSONIC FLOWS BASED ON ELEMENTARY PROCESSES
Authors: RIEDEL U. , MAAS U. , WARNATZ J.
Published: November 2004

The renewed interest in hypersonic flows has created a large demand for physicochemical models for air flow computations around reentry bodies. It is obvious, that besides the improvement of mathematical algorithms for solving the Euler or Navier-Stokes equations detailed physico-chemical models for air in chemical and thermal nonequilibrium are needed for a realistic prediction of hypersonic flowfields. In this paper we present a model, based on elementary physico-chemical processes, for a detailed description of the chemical nonequilibrium together with the excitation of internal degrees of freedom. Results show the strong influence of thermal nonequilibrium on the flowfields.
HEISENBERG ANTIFERROMAGNETIC CHAIN of SPIN S=1
Authors: GOLINELLI O. , JOLICOEUR Th. , LACAZE R.
Published: November 2004

The Heisenberg antiferromagnetic chain of spin 1 with the most general single ion anisotropy is numerically analyzed. Chains of length up to 22 sites are studied by a Lanczös method and up to 32 sites with a quantum Monte Carlo. Gaps, magnetic excitations, dynamical properties and magnetic field behaviour are obtained. The recent neutron scattering experiments on the quasi one-dimensional antiferromagnet NENP are fully explained by our results.
MOLECULAR DYNAMICS AND QUANTUM MOLECULAR DYNAMICS SIMULATIONS ON PARALLEL ARCHITECTURES
Authors: VASHISHTA PRIYA , KALIA RAJIV K. , NAKANO AIICHIRO , YU JIN
Published: November 2004

Efficient parallel molecular dynamics (MD) algorithm based on the multiple-time-step (MTS) approach is developed. The MTS-MD algorithm is used to study structural correlations in porous silica at densities 2.2 g/cm3 to 1.6 g/cm3. Nature of phonons and effects of hydrostatic pressure in solid C60 is studied using the tight-binding MD method within a unified interaction model which includes intermolecular and intra-molecular interactions.
COMPUTATION OF THE NORMAL AND ANOMALOUS TERMS IN THE LOWEST ORDER ANHARMONIC CONTRIBUTIONS TO THE DEBYE-WALLER FACTOR FOR SODIUM METAL
Authors: Dey Sajalendu
Published: November 2004

It has been shown by Maradudin and Flinn1 (1963) that, in weak anharmonic crystals, the lowest order anharmonic contributions to the Debye-Waller factor are of 0(λ2), where λ is the Van Hove2 (1961) ordering parameter. There are four such terms, two of them are of [Formula: see text] (where [Formula: see text] is the scattering wave-vector) and are known as the normal terms. Other two terms are of [Formula: see text] and are known as the anomalous terms. These four terms are of significant complexity. In this present work, a computation of these four terms will be reported for sodium metal and the results will be compared with experimentally determined values.
NONLINEAR MODELING OF THE AIDS VIRUS GENETIC SEQUENCE EVOLUTION
Authors: COCHO G. , GELOVER-SANTIAGO A. , MARTINEZ-MEKLER G. , RODIN A.
Published: November 2004

A network of coupled maps is introduced to model the evolution of the genetic sequence of the HIV1 AIDS virus. Within a space of RNA chemical composition, short range interactions correspond to mutations. Ecological constraints generate long range couplings. The resulting equations are of a reaction-diffusion type. Quasi-species with an error threshold emerge from the model dynamics. Predictions relating chemical composition regularity properties with the variability of the HIV RNA sequence agree with a statistical analysis from gene data banks. The model suggests a clue for an alternative therapeutical treatment.
THE “SPIN” STRUCTURE OF THE NUCLEON — A LATTICE INVESTIGATION
Authors: ALTMEYER R. , SCHIERHOLZ G. , GÖCKELER M. , HORSLEY R. , LAERMANN E.
Published: November 2004

We will discuss here an indirect lattice evaluation of the baryon axial singlet current matrix element. This quantity may be related to the fraction of nucleon spin carried by the quarks. The appropriate structure function has recently been measured (EMC experiment). As in this experiment, we find that the quarks do not appear to carry a large component of the nucleon spin.
THE CHIRAL PHASE TRANSITION IN NON-COMPACT LATTICE QED
Authors: RAKOW P.E.L. , STÜBEN H. , GÖCKELER M. , HORSLEY R. , SCHIERHOLZ G.
Published: November 2004

We give a 1993 update of non-compact lattice QED, in particular the chiral condensate, finite size effects and meson mass ratios. We compare descriptions of the phase transition. Our previous conclusions remain valid.
LANGEVIN METHODS FOR SU(N) CHIRAL MODELS IN TWO DIMENSIONS
Authors: HORGAN R.R. , DRUMMOND I.T.
Published: November 2004

We apply improved Langevin methods with Fourier acceleration to SU(N)×SU(N)/SU(N) spin models in two dimensions for N=3, 4 & 6. We discuss the effect of fourier acceleration and operator improvement techniques, measure the fundamental correlation length on lattices upto 1282 and observe asymptotic scaling in a physical scheme. Bound state masses are also measured and evidence is found for excited states in all channels. Our results are found to be in good agreement with theory.
LATTICE SIMULATIONS OF THE VACUUM STRUCTURE OF QED AND QCD
Authors: BÜRGER W. , FABER M. , MARKUM H. , MÜLLER M. , SAKULER W. , SCHALER M.
Published: November 2004

The charge density around a static charge is investigated within finite temperature QCD and compact QED both in the chirally broken and symmetric phase. We display the functional behavior of the charge polarization for various masses of the sea particles and for static sources in higher representations. The total induced charge is found to be consistent with the results from the MILC Collaboration.
SPECTRUM OF TEXT INFORMATION CONTENT IN THE RNA SEQUENCE OF THE VESICULAR STOMATITIS VIRUS
Authors: FILYUKOV ALEXANDER A.
Published: November 2004

A new strategy to recognize patterns in the DNA sequences with functional significance is proposed. The strategy is based on the general definition of any individual organism as a Gibbsian ensemble of identical personal DNA molecules. This approach provides application of the methods of statistical thermodynamics of irreversible steady processes to genome informatics. The random processes theory and its Markov chains approximation lead in this approach directly to the definition of the generalized concept of evolution entropy and to the genuine measure of text information content in the sequences. Computer-assisted proofs of the existence of the nonequilibrium steady state conditions in genome molecule were obtained by investigation of the special type balance relations in the vesicular stomatitis virus (VSV) RNA sequence. The main maxima of the text information content were decoded and denominated. The established coding principles are connected with deviations from equilibrium conditions and from equipartition.
PROJECTOR APPROXIMATION AND QUANTUM MONTE CARLO
Authors: FYE R.M.
Published: November 2004

We derive a general approximation for performing quantum Monte Carlo simulations within a desired subspace of the full Hilbert space. We analytically determine the form of the resulting systematic error, allowing controlled extrapolation to exact results. We discuss some numerical applications, including fermion impurity and lattice models with infinite on-site Colulomb repulsion U and quantum spin systems. We demonstrate the use of the approximation in simulations with a test model.
APPLICATIONS OF COMPUTER ALGEBRA IN QUANTUM GROUPS
Authors: STEEB W.-H.
Published: November 2004

Quantum groups and quantum algebras play a central role in theoretical physics. We show that computer algebra is a helpful tool in the investigations of quantum groups. We give an implementation of the Kronecker product together with the Yang-Baxter equation. Furthermore the quantum algebra obtained from the Yang-Baxter equation is implemented. We apply the computer algebra package REDUCE.
A STEP TOWARDS LIGHT—LIFE CYCLE GLOBAL HYPERTEXT
Authors: BUNN JULIAN , PALAZZI PAOLO , ROUSSEAU BERTRAND , SMITH MATTHIEW
Published: November 2004

Life Cycle Global HyperText offers easier information access to all members of a software development project, with all documents resulting from the software life cycle being available through WWW hypertext. These documents are connected, via hypertext links, to the documents produced in other stages of the life cycle. To experiment with this concept we have developed converters that transform several kind of documents into the WWW format. Up to now we have focused on source code, but we are now concentrating on documents produced in earlier stages of the software life cycle, such as requirements specification, analysis and design.
HUBBLE SPACE TELESCOPE VIA THE WEB
Authors: O’DEA CHRISTOPHER P.
Published: November 2004

The Space Telescope Science Institute (STScI) makes available a wide variety of information concerning the Hubble Space Telescope (HST) via the Space Telescope Electronic Information Service (STEIS). STEIS is accessible via anonymous ftp, gopher, WAIS, and WWW. The information on STEIS includes how to propose for time on the HST, the current status of HST, reports on the scientific instruments, the observing schedule, data reduction software, calibration files, and a set of publicly available images in JPEG, GIF and TIFF format. STEIS serves both the astronomical community as well as the larger Internet community. WWW is currently the most widely used interface to STEIS. Future developments on STEIS are expected to include larger amounts of hypertext, especially HST images and educational material of interest to students, educators, and the general public, and the ability to query proposal status.
WWW ACCESS TO ASTRONOMICAL ARCHIVES AND DATABASES
Authors: PASIAN FABIO , SMAREGLIA RICCARDO
Published: November 2004

In this document, an approach to the development of WWW-accessible astronomical archives and databases is described, which can easily be extended also to other disciplines. The architecture is based on a set of servers running at the archive site, each performing a specialized task: accessing an SQL-based DBMS, retrieving and downlinking 1-D or 2-D data (measurements), displaying quicklook data, or plotting the results of a query to the database. All of the information on the user interface is dynamically stored in the database, allowing the pages to be prepared on-the-fly; no additional software needs to be run on the user’s computer. A WWW-accessible test astronomical archive, containing both 2-D (images) and 1-D (spectra) data, and having NCSA/Mosaic as an interface is described as an example of successful application of the above concepts.
METEOSAT IR IMAGE PROCESSING AND MPEG ANIMATION
Authors: FILIPPINI LUIGI
Published: November 2004

An HTML demo page, based on the results of a collaboration between CRS4 and CSP, is presented explaining some image processing of meteorogical data. Raw data, obtained every 30 minutes from the METEOSAT satellite, is processed to obtain colored high-contrast images, multiple images are then compressed using the MPEG video standard. The HTML page explains the details of the transformation process and contains links to sample images and the CRS4 MPEG wheather movies archive.
AN ON-LINE NON-LEPTONIC NEURAL TRIGGER APPLIED TO AN EXPERIMENT LOOKING FOR BEAUTY
Authors: BALDANZA C. , BISI F. , COTTA-RAMUSINO A. , D’ANTONE I. , MALFERRARI L. , MAZZANTI P. , ODORICI F. , ODORICO R. , ZUFFA M. , BRUSCHINI C. , MUSICO P. , NOVELLI P. , PASSASEO M.
Published: November 2004

Results from a non-leptonic neural-network trigger hosted by experiment WA92, looking for beauty particle production from 350 GeV π− on a Cu target, are presented. The neural trigger has been used to send on a special data stream (the Fast Stream) events to be analyzed with high priority. The non-leptonic signature uses microvertex detector data and was devised so as to enrich the fraction of events containing C3 secondary vertices (i.e, vertices having three tracks whith sum of electric charges equal to +1 or -1). The neural trigger module consists of a VME crate hosting two ETANN analog neural chips from Intel. The neural trigger operated for two continuous weeks during the WA92 1993 run. For an acceptance of 15% for C3 events, the neural trigger yields a C3 enrichment factor of 6.6–7.1 (depending on the event sample considered), which multiplied by that already provided by the standard non-leptonic trigger leads to a global C3 enrichment factor of ≈150. In the event sample selected by the neural trigger for the Fast Stream, 1 every ≈7 events contains a C3 vertex. The response time of the neural trigger module is 5.8 μs.
IMAGE REFERENCE DATABASE IN TELERADIOLOGY: MIGRATING TO WWW
Authors: PASQUI VALDO
Published: November 2004

The paper presents a multimedia Image Reference Data Base (IRDB) used in Teleradiology. The application was developed at the University of Florence in the framework of the European Community TELEMED Project. TELEMED overall goals and IRDB requirements are outlined and the resulting architecture is described. IRDB is a multisite database containing radiological images, selected because their scientific interest, and their related information. The architecture consists of a set of IRDB Installations which are accessed from Viewing Stations (VS) located at different medical sites. The interaction between VS and IRDB Installations follows the client-server paradigm and uses an OSI level-7 protocol, named Telemed Communication Language. After reviewing Florence prototype implementation and experimentation, IRDB migration to World Wide Web (WWW) is discussed. A possible scenery to implement IRDB on the basis of WWW model is depicted in order to exploit WWW servers and browsers capabilities. Finally, the advantages of this conversion are outlined.
MICROCANONICAL SIMULATIONS OF ELASTIC-DISK SYSTEMS
Authors: VERMÖHLEN WOLFGANG , ITO NOBUYASU
Published: November 2004

We performed MD-simulation of two dimensional elastic disks in a microcanonical ensemble and observed the pressure versus the density for the different elastic moduli. As was found in Alder’s simulation, we reconfirmed a plateau in the (pred, ρ*) diagram as an indication for a phase transition with better statistics and observed its dependence on the elastic modulus. This dependence can be explained by the effective density reduction due to the elasticity of the disks. This suggests the universality of the Alder transition of the hard core potential for the contacting elastic potentials. A discussion of a geometrical order parameter |ɸ|2 is included.
MODELING IMMUNE NETWORK THROUGH CELLULAR AUTOMATA: A UNIFIED MECHANISM OF IMMUNOLOGICAL MEMORY
Authors: CHOWDHURY DEBASHISH , DESHPANDE VARSHA , STAUFFER DIETRICH
Published: November 2004

The populations of the various types of immunocompetent cells in the immune system are described as cellular automata and the population dynamics of these cells are formulated in terms of dynamical maps in discrete time. Both intra-clonal interactions (i.e., interactions among the cell types belonging to the same clone) and inter-clonal interactions (i.e., interactions among the cell types belonging to different clones) are included in the models proposed here. While the intra-clonal interactions are shown to play a crucial role in the primary response of some clones and in the formation of the immunological memory, the inter-clonal interactions are responsible for retaining the memory through a dynamical process driven by the mutual stimulation of the clones. We present the results for two different types of connectivity, namely, a “necklace” network and a network in “shape space”.
MEAN-FIELD THEORY OF ANYONS NEAR BOSE STATISTICS
Authors: MCCABE JOHN , MACKENZIE RICHARD
Published: November 2004

We argue the validity of a mean-field approximation for a free anyon gas near Bose statistics, and show that the anyon gas can exhibit a Meissner effect in the domain of validity of the approximation only due to a hard-core repulsion.
TWO ANYONS IN A CONSTANT MAGNETIC FIELD: A NONPERTURBATIVE APPROACH
Authors: ROY B. , ROY P. , VARSHNI Y.P.
Published: November 2004

Using two nonperturbative methods, namely, the shifted 1/N expansion and the SWKB techniques, we determine the energy levels of a system of two anyons in an external constant magnetic field and interacting via a Coulomb repulsion. Some exact results have also been found using the notion of supersymmetry.
SCALING OF RESISTANCE IN THE TWO-DIMENSIONAL ANDERSON TIGHT-BINDING MODEL OF DISORDERED SYSTEMS II
Authors: SAIN ANIRBAN , MOOKERJEE ABHIJIT
Published: November 2004

Several workers using different numerical methods have in recent times obtained algebraic decay of wave function amplitudes for localized states at the band center of a two-dimensional disordered system. These include vector recursion,1 direct diagonalization,2 and real space renormalization techniques.3 We modify a version of the combined real space renormalization and vector recursion techniques, including the effect of the random environment on the phase differences between the electronic incoming waves through the different incoming leads, to confirm the algebraic or weak localization at the band center of a random tight-binding Anderson model in two dimensions.
QUANTUM GROUP AND MAGNETIC TRANSLATIONS: BETHE ANSATZ SOLUTION FOR THE HARPER’S EQUATION
Authors: WIEGMANN P.B. , ZABRODIN A.V.
Published: November 2004

We present the Bethe ansatz solution for the problem of Bloch electrons in magnetic field described by the Harper’s equation [Formula: see text] We made explicit a natural relation between magnetic translations and the quantum group Uq(sl2) and express the midband spectrum and the Bloch function in terms of solutions of the Bethe ansatz equations. In this letter we present solution for the critical value λ=1.
DEFECT DYNAMICS IN PURE CeO2 STUDIED BY PERTURBED ANGULAR CORRELATIONS USING 181Hf
Authors: REQUEJO F.G. , BIBILONI A.G. , MASSOLO C.P. , FREITAG K.
Published: November 2004

Perturbed angular correlation (PAC) measurements were performed in pure cerium dioxide using 181 Hf as the probe. The activity was introduced by ionic implantation on pure CeO 2 pressed powder. The substitutional replacement of Ce by Hf and the removal of radiation damage due to the ion implantation were achieved through thermal treatments in air at increasing temperatures up to 1323 K. Once an unperturbed cubic environment for the hafnium probes was verified through PAC measurements at room temperature, thermal treatments in low O 2 pressure were performed in order to create oxygen vacancies in the sample. Subsequent PAC measurements in the temperature range 77 to 300 K revealed the presence of static defects at low temperatures that become mobile at room temperature. The defects were identified as oxygen vacancies probably at second neighbor sites. Our results are compatible with an activation energy for oxygen vacancy hopping in the order of 0.40 eV.
STATISTICS TRANSMUTATIONS IN TWO-DIMENSIONAL SYSTEMS AND THE FRACTIONAL QUANTUM HALL EFFECT
Authors: SITKO PIOTR
Published: November 2004

Statistics transmutations to superfermions in fractional quantum Hall effect systems are considered in the Hartree-Fock approximation and in the RPA. The Hartree-Fock ground state energy shows that the transmutations are not energetically preferable. Within the RPA it is found that the system exhibits a fractional quantum Hall effect.
ANOMALOUS LENGTH DEPENDENCE OF THE CONDUCTANCE OF A 2D CHANNEL NEAR THE THRESHOLD
Authors: RAIKH M. E. , PIKUS F. G.
Published: November 2004

The modification of the potential profile in the channel of metal oxide semiconductor field effect transistors, caused by electrons in n+ contacts attracted to the surface by the gate voltage, is considered. Effective narrowing of the channel region, in which the transport is due to the phonon-assisted tunneling, could be responsible for the dramatic increase of the conductance with channel length in the strongly localized regime, as observed by Popović, Fowler, and Washburn.1
BASIC FORMS OF CHAOTIC ATTRACTORS AND THEIR IMPLICATIONS
Authors: MOON HIE-TAE
Published: November 2004

We discuss here three basic forms of chaotic attractors and their implications in broad natural complex phenomena. In doing so, we outline recent new modes of thinking toward the understanding of such complex behavior.
CONTINUOUS UPPER BOUND ON THE GROUND-STATE ENERGY OF THE FRÖHLICH POLARON
Authors: SOLDATOV A. V.
Published: November 2004

The upper bound on the ground-state energy for the Fröhlich polaron is derived by means of a new version of variational principle based on the Wick symbols formalism and the coherent states theory. The bound is continuous in some respect, i.e. it is valid for all values of coupling parameter including the intermediate regions. Asymptotic behavior of the bound for the weak coupling limit and for the strong coupling limit provides, in general, lower values than well-known existing bounds. The bound can be readily generalized for the case of nonzero magnetic field.
EFFECT OF DOPING Zn ON THE ELECTRONIC STRUCTURE Of La1.85Sr0.15CuO4
Authors: HAO XUE-JUN , ZHOU YUN-SONG , ZHANG LI-YUAN , WANG HUAI-YU
Published: November 2004

The change of the electronic structure of La 1.85 Sr 0.15 CuO 4 caused by the local substitution of Zn for Cu has been calculated by the recursion method. The partial wave density of states, the intensity of bonds, and the atomic valence, etc. are obviously affected by Zn on the doped site and its neighbors. The 2D electronic structure and magnetic structure are destroyed locally. We think these, together with the local increase of Cu holes, decrease of O2 holes, and the inducement of a net magnetic moment of 1.3 µB are responsible for the rapid suppression of superconductivity in Zn-doped La 1.85 Sr 0.15 CuO 4 materials.
SOLVING AN INTERFACIAL STRUCTURE WITH MULTIPLE WAVELENGTH ANOMALOUS DISPERSION (MAD)
Authors: TWEET DOUGLAS J. , AKIMOTO KOICHI
Published: November 2004

Recently, we have modified the multiple wavelength anomalous dispersion (MAD), a powerful direct method, and applied it for the first time to an interface. This allows us to separate heavy and light atoms, and so deduce the structure. Here we give the details of that work, discussing the system studied, the experimental techniques, and the final model structure, especially focusing on the use of the MAD analysis method.
DIFFUSIVE AND FRUSTRATED TRANSLATIONAL MODES OF ADATOM DYNAMICS
Authors: CHEN L. Y. , YING S. C.
Published: November 2004

We briefly review recent developments in probing diffusion and frustrated translational modes of adatoms on solid surfaces. Helium scattering technique has been successfully employed to measure not only the diffusion but also the parallel vibration. A microscopic theoretical formulation enables us to evaluate the velocity autocorrelations and the dynamic structure factor which characterizes the Helium scattering spectrum. The quasielastic scattering peak in the dynamical structure factor is found to consist of mixed contributions from diffusive and vibrational modes. The vibrational peak indicates a shift and broadening from anharmonic effects and frictional damping. When the frictional coefficient is varied at low temperatures, the diffusion constant crosses over smoothly from multisite jumping regime at low friction via the transition state regime to the high friction overdamped regime.
SEPARATION OF THE INDUCED MAGNETIZATION IN THE ONE-DIMENSIONAL XY MODEL
Authors: DE LIMA J. P. , GONÇALVES L. L.
Published: November 2004

The one-dimensional (s = 1/2, open chain) isotropic ferromagnetic XY model in an inhomogeneous transverse field is considered. The exact profile of the induced magnetization is obtained by using the Green function technique. Results are presented for the magnetization profile at different finite temperatures and various strengths of the field. In the scaling region, from the analytical results obtained for the profile of the interface at T = 0, and by a suitable renormalization of the magnetization, it is shown that near the critical point it satisfies a scaling relation identical to the one obtained by van der Waals theory for fluids, provided the correlation length is adequately defined.
STRETCHED EXPONENTIAL RELAXATION ANALYSIS OF THE MOISTURE DIFFUSION IN CARBON FIBER SAMPLES
Authors: GIARETTO V. , RUSCICA G. , MIRALDI E.
Published: November 2004

The ending part of the desorption of water molecules from carbon fiber composite plates is analyzed in terms of a stretched exponential decay function. The physical process of mass transport right to the fibers epoxy interfaces through the plastic material is discussed. Further, by analogy with the heat transfer mechanism, it is shown that the parameters useful to describe the mass variations in time are related to the mass diffusion coefficient and to the Biot number for the mass transport through a characteristic length of the sample, namely, the ratio between its volume and surface. The global average drift velocity of a water molecule through the sample has been introduced to describe the moisture transfer process. The experimental data fit very well to the theoretical curves and validate the global approach used.
ELECTROMAGNETIC WAVES IN A NONSUPERCONDUCTING ANYON MATTER
Authors: ARONOV IGOR E. , KRIVE ILYA V. , NAFTULIN SERGEY A. , WENDIN GÖRAN
Published: November 2004

Normal modes of free electromagnetic oscillations in a two-dimensional anyon gas above the critical temperature of the superconducting phase transition are considered. Making use of the average statistical field approximation we derive the long wave effective Lagrangian for the electromagnetic field in anyon medium and analyze the dependence of thermodynamic parameters entering into the Lagrangian (zero frequency dielectric and magnetic permeabilities, the "Hall conductivity" and the electrostatic screening length) on the temperature, particle density, and statistical parameter θ. It is shown that the only propagating electromagnetic excitation in a nonsuperconducting anyon medium is the chiral helicon wave analogous to the magnetic helicon found previously in the quantum Hall systems.
SHEAR-INDUCED MIXING IN POLYMER BLENDS
Authors: HOBBIE ERIK K. , NAKATANI ALAN I. , HAN CHARLES C.
Published: November 2004

The effect of shear flow on phase separation in critical polymer blends is reviewed. For a low-molecular-weight blend, the response is in good agreement with the theoretical predictions of Onuki and Kawasaki. The break-up of large-scale critical fluctuations by the flow leads to a drop in the temperature T c at which phase separation begins. For a high-molecular-weight blend, the data suggest that the mode-coupling contribution to the decay rate of composition fluctuations is significant in both the miscible and immiscible phases. No shear-induced shift in T c is apparent at any temperature in the one-phase region away from the equilibrium critical point, consistent with mean-field statics.
DIELECTRIC SCREENING IN CHARGED BOSE VERSUS FERMI LIQUIDS
Authors: CHIOFALO M.L. , CONTI S. , TOSI M.P.
Published: November 2004

We briefly review the available theoretical results on dielectric screening properties of a fluid of charged bosons at zero temperature in comparison with those of a fluid of charged fermions. The paper is intended to highlight for the nonspecialists the differences in behavior that arise from the difference in statistics. After a general introduction to the dielectric screening function and to the local field factor accounting for exchange and correlation in dielectric screening, we focus on (i) the dependence of the static dielectric function on wave number and the screening of a charged impurity, (ii) the structure factor, the pair distribution function, and the ground state energy, and (iii) the spectrum of collective excitations. The review is concluded with some remarks on open questions and possible further developments.
NONCHARGE TRANSFER, DIMERIZATION, AND ELECTRON LOCALIZATION EFFECTS IN ALKALI-DOPED C60
Authors: GARAVELLI S.L. , FERRAZ A.
Published: November 2004

In this work we argue that Na 3 C 60 is an insulator because the Na+ cations recapture their valence electrons forming one center electronic bound state in the fulleride medium. In the A 4 C 60 compounds the alkali atoms should approach each other in pairs forming alkali dimer states. A 4 C 60 is therefore a noncharge transfer insulator and is nonsuperconducting. Finally we conjecture that there may exist Na 2 states in Na 6 C 60.
NUMERICAL MODELING OF MORPHOLOGICAL CHANGES OF THE FRACTURE PROPAGATION IN THE QUENCHED GLASS PLATE
Authors: TAGUCHI Y.-H.
Published: November 2004

A model for crack propagation is proposed that reproduces, for the first time, the morphological transitions of cracks in the quenched glass plate recently observed by Yuse and Sano [Nature362, 329 (1993)].
ON THE K STATE EFFECT IN INTERSTITIAL ALLOYS: ANOMALOUS RESISTIVITY BEHAVIOR IN DAMAGED β-PdH(D)0.63
Authors: VAJDA P.
Published: November 2004

After a brief description of the K state phenomenon in short-range-ordered substitutional alloys, it is shown that this effect also exists in an interstitial alloy β- PdH(D) 0.63, whose low-temperature resistivity decreases after a quench across the order-disorder transition region around 50 K and/or after electron irradiation.
A “Jc EXPECTATION RULE” FOR YBCO THIN FILMS PREPARED BY MOCVD AND LASER ABLATION
Authors: ZHONG Q. , CHOU P.C. , LI Q.L. , IGNATIEV A.
Published: November 2004

An empirical “J c expectation rule” has been devised for YBCO thin films (1000–8000 Å) deposited on various substrates by MOCVD and laser ablation techniques. The “rule” is based on a normal state parameter M defined as the ratio of ΔR/ΔT and R/T, and directly predicts J c from resistivity measurements. The parameter also serves to delineate three general regions of J c behavior that are proposed to be linked to film characteristics.
HYDROGENIC SLATER RADIAL INTEGRALS WITH DISCRETE PARAMETERS AND THEIR ASYMPTOTICS
Authors: TARASOV V.F.
Published: November 2004

Two-electronic matrix elements of the electrostatic interaction energy operator contain the hydrogenic radial integrals Rk(ab, cd) introduced by J.C. Slater. Their calculation and properties are widely used in the theory of atomic spectra. This paper deals with the study of these integrals by a new method, i.e. with the help of Appell hypergeometrical functions F2(x, y) and their new properties. The exact analytical expressions for Slater radial integrals Rk, Gk, and Fk by means of Appell’s functions F2(x, y) as well as the asymptotics of the general integral Rk, by one and two parameters in terms of Horn’s functions Ψ1(x, y) are obtained.
ELECTROSTATIC SCREENING IN FULLERENE COMPOUNDS
Authors: GONZÁLEZ J. , GUINEA F. , VOZMEDIANO M.A.H.
Published: November 2004

We study the Coulomb interactions in fullerene compounds within a continuum formalism. The model gives rise to a renormalizable field theory, which has many similarities to standard quantum electrodynamics. The effective electric charge at low energies is reduced by screening processes. The associated renormalization of the one-electron Green’s function leads to the vanishing of the quasiparticle pole. It implies the disappearance of coherent one-particle excitations, in close analogy to the one-dimensional Luttinger liquid. The relevance of these results for C 60 and related molecules is discussed.
THE MECHANICAL ACTION OF LASER LIGHT ON RYDBERG ATOMS
Authors: ALBER G. , STRUNZ W.T. , ZOBAY O.
Published: November 2004

The momentum exchange between a standing wave laser field and an atomic center-of-mass is dominated by the internal dynamics of an atomic electron in the exciting laser field. Rydberg atoms are one of the simplest physical systems where the dependence of this radiative force on the electronic dynamics can be investigated in detail. The characteristics of the momentum transfer between an atomic center-of-mass and a standing wave laser field strongly depend on whether the “particle” or the “wave” aspect of the electronic dynamics prevail. In this review recent theoretical advances in the description of the mechanical action of laser light on Rydberg atoms are discussed. These advances have become possible by the application of semiclassical path integral techniques with respect to the electronic dynamics which clearly exhibit the “particle” and “wave” aspects of this momentum transfer.
QUASIPERIODIC ROUTE TO SPATIOTEMPORAL CHAOS IN A NONLINEAR SCHRÖDINGER EQUATION WITH THE SATURABLE NONLINEARITY
Authors: ZHOU CANGTAO
Published: November 2004

The route from the coherent structures to the spatiotemporal complicated patterns is numerically investigated in terms of a continuum Hamiltonian system, that is, the non-linear Schrödinger equation with the self-focusing nonlinearity, where the quasiperiodic route is first observed.
WAVE FUNCTION OF THE PARTICLE TRAPPED BY OSCILLATING FIELDS
Authors: DANTAS CÉLIA M.A. , BAGNATO V.S. , BASEIA B.
Published: November 2004

In a previous paper [Quantum Opt.5, 155 (1993)] we have employed a recent model by Glauber for particle trapping by oscillating fields to investigate the occurrence of the squeezing effect for this system. Here we construct a linear time-dependent invariant which allows us to obtain the wave function of the system. The treatment is general for a class of time-dependent Hamiltonian, the application to our previous work being a particularization of the present procedure.
POPULATION TRAPPING IN A GENERALIZED JAYNES-CUMMINGS MODEL
Authors: DANTAS CÉLIA M.A. , BAGNATO V.S. , BASEIA B. , CHABA A.N.
Published: November 2004

In recent literature the expression for the population inversion in the Jaynes-Cummings model was obtained for the most general initial state of the field-atom system, allowing the investigation of the population trapping problem. Here we extend this study to the case of multiphoton interaction where coherent and incoherent trappings are investigated, the mentioned results of literature becoming a particularization of ours.
YIELD PROCESS OF ELECTRORHEOLOGICAL FLUID WITH POLYANILINE PARTICLE
Authors: KOYAMA KIYOHITO , MINAGAWA KEIJI , YOSHIDA TAMOTSU , KURAMOTO NORIYUKI , TANAKA KATSUFUMI
Published: November 2004

Electrorheological behaviors of polyaniline/silicone oil suspension were observed by using a modified Couette type rheometer with high resolution for shear stress. The yield behaviors were examined over a wide range of shear strain. The storage modulus and loss tangent were determined under a constant dc electric field. It was clarified that the polyaniline-based ER fluid yields two different strain amplitudes, i.e. about 1% and 50%. The stress-strain curves obtained from shear flow experiments also suggested the existence of two-step yield process. The yield process was found to be dependent on the electric field strength and the particle concentration in different manners. The yield behavior observed is discussed in relation to the structure of particle clusters which causes the ER effect.