bluuebunny/crossref_metadata_2025 huggingface dataset:
A radiation-driven model for crown fire spread
Authors: Butler B W , Finney M A , Andrews P L , Albini F A
Published: September 2004

A numerical model for the prediction of the spread rate and intensity of forest crown fires has been developed. The model is the culmination of over 20 years of previously reported fire modeling research and experiments; however, it is only recently that it has been formulated in a closed form that permits a priori prediction of crown fire spread rates. This study presents a brief review of the development and structure of the model followed by a discussion of recent modifications made to formulate a fully predictive model. The model is based on the assumption that radiant energy transfer dominates energy exchange between the fire and unignited fuel with provisions for convective cooling of the fuels ahead of the fire front. Model predictions are compared against measured spread rates of selected experimental fires conducted during the International Crown Fire Modelling Experiment. Results of the comparison indicate that the closed form of the model accurately predicts the relative response of fire spread rate to fuel and environment variables but overpredicts the magnitude of fire spread rates.
Evaluating fire shelter performance in experimental crown fires
Authors: Putnam T , Butler B W
Published: September 2004

Fire shelters are critical safety items required for use by most wildland firefighters in the United States. Most testing of fire shelters, clothing and other personal protective equipment (PPE) has been limited to prescribed fires or laboratory based studies. This study reports results from experiments where lined and unlined stainless steel or aluminum and glass fabric shelters were tested under high intensity crown fire conditions in and adjacent to experimental burn plots. Firefighter clothing and standard (pre-2003) fire shelters were also tested. Measured shelter surface and air temperatures and thermal impact on firefighter personal protective equipment were used to deduce the survivability of shelter designs and deployment location. Multiple glass and aluminum layered shelters show more promise than stainless steel shelters for improving overall fire shelter survivability. Data collected outside the burn plots generally indicate decreased heating as distance from forest edge increases, supporting the importance of maximizing distance from vegetation for survivability. It is recommended that common experiment protocols be adopted so that future research into fire shelter and PPE performance builds on work-to-date and provides a common basis from which analyses can be completed.
Variation in wind and crown fire behaviour in a northern jack pine  black spruce forest
Authors: Taylor S W , Wotton B M , Alexander M E , Dalrymple G N
Published: September 2004

Fire spread and flame temperature were examined in a series of nine experimental crown fires conducted in the Northwest Territories, Canada. Average rates of spread were 17.866.8 m·min1 (0.31.1 m·s1) over burning periods from about 1.510 min across 75 m × 75 m to 150 m × 150 m plots. Detailed maps of fire front progression revealed areas with higher rates of spread in the order of tens of metres in horizontal dimension and tens of seconds in duration in several of the fires, which is consistent with the influence of coherent wind gusts. Comparison of open and in-stand wind speed before and after burning suggests that defoliation in the canopy layer during burning would result in the flaming zone having greater exposure to the ambient wind. Estimates of flame front residence from video observations at the surface averaged 34 s; estimates from temperature measurements decreased significantly with height from 74 s at the surface to 31 s below the canopy.
Severe red spruce winter injury in 2003 creates unusual ecological event in the northeastern United States
Authors: Lazarus Brynne E , Schaberg Paul G , DeHayes Donald H , Hawley Gary J
Published: September 2004

Abundant winter injury to the current-year (2002) foliage of red spruce (Picea rubens Sarg.) became apparent in the northeastern United States in late winter of 2003. To assess the severity and extent of this damage, we measured foliar winter injury at 28 locations in Vermont and surrounding states and bud mortality at a subset of these sites. Ninety percent of all trees assessed showed some winter injury, and trees lost an average of 46% of all current-year foliage. An average of 32% of buds formed in 2002 were killed in association with winter injury. Both foliar and bud mortality increased with elevation and with crown dominance, and bud mortality increased with greater foliar injury. Foliar injury in 2003 at a plantation near Colebrook, New Hampshire, was more than five times the typical levels for 9 previous years of measurement and more than twice that measured for another high-injury year. Plantation data also indicated that bud mortality in 2003 was greater than previously documented and that persistent winter injury was associated with increased tree mortality. Comparisons of our data with past studies for two sites with native red spruce also indicated that damage in 2003 was greater than other recently reported, high-injury years. Because heavy foliar and bud losses can severely disrupt the carbon economies of trees, the 2003 winter injury event could lead to further spruce decline and mortality, particularly among dominant trees at higher elevations.
Overview of the International Crown Fire Modelling Experiment (ICFME)
Authors: Stocks B J , Alexander M E , Lanoville R A
Published: September 2004

The International Crown Fire Modelling Experiment (ICFME), carried out between 1995 and 2001 in Canada's Northwest Territories, involved 18 experimental high-intensity crown fires, with more than 100 participants representing 30 organizations from 14 countries. ICFME has provided valuable new data and insights into the nature and characteristics of crowning forest fires, which will assist in addressing fire management problems and opportunities affecting both people and ecosystems in future decades. ICFME evolved as the result of a number of converging issues: the recognition that the US and Canada could not continue separate approaches to fire behaviour model development, the opening of Russia to the western world, increased communication, and the formation of international associations to facilitate collaboration. While the initial impetus for ICFME was the desire to improve the physical modeling of crown fire propagation and spread, the project also created the opportunity to examine many other aspects and impacts of crown fires. This special issue of the Canadian Journal of Forest Research devoted to ICFME is intended to summarize most of the major research results from the project.
ARTIFICIAL NEURAL NETWORK BASED SOFT ESTIMATOR FOR ESTIMATION OF TRANSDUCER STATIC NONLINEARITY
Authors: SINGH AMAR PARTAP , KAMAL TARA SINGH , KUMAR SHAKTI
Published: September 2004

In this work, the development of an Artificial Neural Network (ANN) based soft estimator is reported for the estimation of static-nonlinearity associated with the transducers. Under the realm of ANN based transducer modeling, only two neural models have been suggested to estimate the static-nonlinearity associated with the transducers with quite successful results. The first existing model is based on the concept of a functional link artificial neural network (FLANN) trained with μ-LMS (Least Mean Squares) learning algorithm. The second one is based on the architecture of a single layer linear ANN trained with α-LMS learning algorithm. However, both these models suffer from the problem of slow convergence (learning). In order to circumvent this problem, it is proposed to synthesize the direct model of transducers using the concept of a Polynomial-ANN (polynomial artificial neural network) trained with Levenberg-Marquardt (LM) learning algorithm. The proposed Polynomial-ANN oriented transducer model is implemented based on the topology of a single-layer feed-forward back-propagation-ANN. The proposed neural modeling technique provided an extremely fast convergence speed with increased accuracy for the estimation of transducer static nonlinearity. The results of convergence are very stimulating with the LM learning algorithm.
GLOBAL ROBUST STABILITY FOR SHUNTING INHIBITORY CNNs WITH DELAYS
Authors: WANG LINGNA , LIN YIPING
Published: September 2004

In this paper, the problem of global robust stability for shunting inhibitory cellular neural networks (SICNNs) is studied. A sufficient condition guaranteeing the network's global robust stability is established. The result can easily be used to verify globally robust stable networks. An example is given to illustrate that the conditions of our results are feasible.
MODEL-FREE FUNCTIONAL MRI ANALYSIS USING TOPOGRAPHIC INDEPENDENT COMPONENT ANALYSIS
Authors: MEYER-BÄSE ANKE , LANGE OLIVER , WISMÜLLER AXEL , RITTER HELGE
Published: September 2004

Data-driven fMRI analysis techniques include independent component analysis (ICA) and different types of clustering in the temporal domain. Since each of these methods has its particular strengths, it is natural to look for an approach that unifies Kohonen's self-organizing map and ICA. This is given by the topographic independent component analysis. While achieved by a slight modification of the ICA model, it can be at the same time used to define a topographic order (clusters) between the components, and thus has the usual computational advantages associated with topographic maps. In this contribution, we can show that when applied to fMRI analysis it outperforms FastICA.
OPTIMAL COMPETITIVE HOPFIELD NETWORK WITH STOCHASTIC DYNAMICS FOR MAXIMUM CUT PROBLEM
Authors: WANG JIAHAI , TANG ZHENG , CAO QIPING , WANG RONGLONG
Published: September 2004

In this paper, introducing stochastic dynamics into an optimal competitive Hopfield network model (OCHOM), we propose a new algorithm that permits temporary energy increases which helps the OCHOM escape from local minima. The goal of the maximum cut problem, which is an NP-complete problem, is to partition the node set of an undirected graph into two parts in order to maximize the cardinality of the set of edges cut by the partition. The problem has many important applications including the design of VLSI circuits and design of communication networks. Recently, Galán-Marín et al. proposed the OCHOM, which can guarantee convergence to a global/local minimum of the energy function, and performs better than the other competitive neural approaches. However, the OCHOM has no mechanism to escape from local minima. The proposed algorithm introduces stochastic dynamics which helps the OCHOM escape from local minima, and it is applied to the maximum cut problem. A number of instances have been simulated to verify the proposed algorithm.
TEMPLATE LEARNING OF CELLULAR NEURAL NETWORK USING GENETIC PROGRAMMING
Authors: RADWAN ELSAYED , TAZAKI EIICHIRO
Published: September 2004

A new learning algorithm for space invariant Uncoupled Cellular Neural Network is introduced. Learning is formulated as an optimization problem. Genetic Programming has been selected for creating new knowledge because they allow the system to find new rules both near to good ones and far from them, looking for unknown good control actions. According to the lattice Cellular Neural Network architecture, Genetic Programming will be used in deriving the Cloning Template. Exploration of any stable domain is possible by the current approach. Details of the algorithm are discussed and several application results are shown.
A SYSTEMATIC STUDY OF Zr AND Sn ISOTOPES IN THE RELATIVISTIC MEAN FIELD THEORY
Authors: GENG L. S. , TOKI H. , MENG J.
Published: September 2004

The ground-state properties of Zr and Sn isotopes are studied within the relativistic mean field theory. Zr and Sn isotopes have received tremendous attention due to various reasons, including the predicted giant halos in the neutron-rich Zr isotopes, the unique feature of being robustly spherical in the region of 100 Sn ~132 Sn and the particular interest of Sn isotopes to nuclear astrophysics. Furthermore, four (semi-) magic neutron numbers, 40, 50, 82 and 126, make these two isotopic chains particularly important to test the pairing correlations and the deformations in a microscopic model. In the present work, we carry out a systematic study of Zr and Sn isotopes from the proton drip line to the neutron drip line with deformation effects, pairing correlations and blocking effects for nuclei with odd number of neutrons properly treated. A constrained calculation with quadrupole deformations is performed to find the absolute minimum for each nucleus on the deformation surface. All ground-state properties, including the separation energies, the odd–even staggerings, the nuclear radii, the deformations and the single-particle spectra are analyzed and discussed in detail.
FREE-FERMION ENERGIES IN THE SU(N) PERK-SCHULTZ MODEL
Authors: ALCARAZ F. C. , STROGANOV YU. G.
Published: September 2004

Basing on the numerical observations of the eigenspectra of the SU(N) Perk-Schultz model at the special value of the anisotropy q= exp (iπ(N-1)/N), we formulate a set of conjectures concerning the existence of the free-fermion like eigenenergies. We prove analytically a part of these conjectures.
INTEGRABLE N-LEG LADDER MODELS
Authors: ARNAUDON D. , SEDRAKYAN A. , SEDRAKYAN T.
Published: September 2004

We construct integrable spin chains with the inhomogeneous periodic disposition of the anisotropy parameter. The periodicity holds for both auxiliary (space) and quantum (time) directions. The integrability of the model is based on a set of coupled Yang–Baxter equations. This construction yields the P-leg integrable ladder Hamiltonians. We analyse the corresponding quantum group symmetry.
TOWARDS THE CONSTRUCTION OF WIGHTMAN FUNCTIONS OF INTEGRABLE QUANTUM FIELD THEORIES
Authors: BABUJIAN H. , KAROWSKI M.
Published: September 2004

The purpose of the "bootstrap program" for integrable quantum field theories in 1+1 dimensions is to construct a model in terms of its Wightman functions explicitly. In this article, the program is mainly illustrated in terms of the sine-Gordon and the sinh-Gordon model and (as an exercise) the scaling Ising model. We review some previous results on sine-Gordon breather form factors and quantum operator equations. The problem to sum over intermediate states is attacked in the short distance limit of the two point Wightman function for the sinh-Gordon and the scaling Ising model.
CENTRAL ELEMENTS OF THE ELLIPTIC YANG–BAXTER ALGEBRA IN ROOTS OF UNITY
Authors: BELAVIN A. , JIMBO M.
Published: September 2004

We describe the center of the algebra of monodromy matrices connected with the R-matrix of the eight-vertex model in the case where the crossing parameter has rational values.
EMPTINESS FORMATION PROBABILITY AND QUANTUM KNIZHNIK-ZAMOLODCHIKOV EQUATION
Authors: BOOS H. E. , KOREPIN V. E. , SMIRNOV F. A.
Published: September 2004

We consider the one-dimensional XXX spin 1/2 Heisenberg antiferromagnet at zero temperature and zero magnetic field. We are interested in a probability of a formation of a ferromagnetic string P(n) in the antiferromagnetic ground-state. We call it emptiness formation probability [EFP]. We suggest a new technique for computation of the EFP in the inhomogeneous case. It is based on the quantum Knizhnik-Zamolodchikov equation [qKZ]. We calculate EFP for n≤6 for the inhomogeneous case. The homogeneous limit confirms our hypothesis about the relation of quantum correlations and number theory. We also make a conjecture about a structure of EFP for arbrary n.
CLASSICALLY INTEGRABLE FIELD THEORIES WITH DEFECTS
Authors: BOWCOCK P. , CORRIGAN E. , ZAMBON C.
Published: September 2004

Some ideas and remarks are presented concerning a possible Lagrangian approach to the study of internal boundary conditions relating integrable fields at the junction of two domains. The main example given in the article concerns single real scalar fields in each domain and it is found that these may be free, of Liouville type, or of sinh-Gordon type.
APPLICATIONS OF QUANTUM INTEGRABLE SYSTEMS
Authors: CASTRO-ALVAREDO O. A. , FRING A.
Published: September 2004

We present two applications of quantum integrable systems. First, we predict that it is possible to generate high harmonics from solid state devices by demonstrating that the emission spectrum of a minimally coupled laser field of frequency ω to an impurity system of a quantum wire, contains multiples of the incoming frequency. Second, by evaluating expressions for the conductance in the high temperature regime we show that multiples of the characteristic filling fractions of the Jain sequence, which occur in the fractional quantum Hall effect, can be obtained from quantum wires which are described by minimal affine Toda field theories.
FERMIONIC SUBSPACES OF THE BOSONIC STRING
Authors: CHATTARAPUTI A. , ENGLERT F. , HOUART L. , TAORMINA A.
Published: September 2004

A universal symmetric truncation of the bosonic string Hilbert space yields all known closed fermionic string theories in ten dimensions, their D-branes and their open descendants. We highlight the crucial role played by group theory and two-dimensional conformal field theory in the construction and emphasize the predictive power of the truncation. Such circumstantial evidence points towards the existence of a mechanism which generates space-time fermions out of bosons dynamically within the framework of bosonic string theory.
CORRELATION FUNCTIONS OF DISORDER OPERATORS IN MASSIVE FREE THEORIES
Authors: DELFINO G. , GRINZA P. , MOSCONI P. , MUSSARDO G.
Published: September 2004

A unified analysis of the disorder operators for ghosts, complex boson and fermion fields is presented. Matrix elements on the asymptotic states of these operators can be exactly computed by solving the Form Factor functional equations. The two–point correlation functions of the disorder operators depend only on the statistics and can be expressed in terms of a solution of a non–linear differential equation of Painleve' type.
TWO CHARACTER FORMULAS FOR $\widehat{\mathfrak{sl}}_2$ SPACES OF COINVARIANTS
Authors: FEIGIN B. , JIMBO M. , LOKTEV S. , MIWA T.
Published: September 2004

We consider [Formula: see text] spaces of coinvariants with respect to two kinds of ideals of the enveloping algebra [Formula: see text]. The first one is generated by [Formula: see text], and the second one is generated by [Formula: see text], [Formula: see text] where P(t), [Formula: see text] are fixed generic polynomials. (We also treat a generalization of the latter.) Using a method developed in our previous paper, we give new fermionic formulas for their Hilbert polynomials in terms of the level-restricted Kostka polynomials and q-multinomial symbols. As a byproduct, we obtain a fermionic formula for the fusion product of [Formula: see text]-modules with rectangular highest weights, generalizing a known result for symmetric (or anti-symmetric) tensors.
EXCITED BOUNDARY TBA IN THE TRICRITICAL ISING MODEL
Authors: FEVERATI G. , PEARCE P. A. , RAVANINI F.
Published: September 2004

By considering the continuum scaling limit of the A4 RSOS lattice model of Andrews-Baxter-Forrester with integrable boundaries, we derive excited state TBA equations describing the boundary flows of the tricritical Ising model. Fixing the bulk weights to their critical values, the integrable boundary weights admit two parameters ξ and η which play the role of the perturbing boundary fields φ1,3 and φ1,2 and induce the renormalization group flow between boundary fixed points. The boundary TBA equations determining the RG flows are derived in the [Formula: see text] example. The induced map between distinct Virasoro characters of the theory are specified in terms of distribution of zeros of the double row transfer matrix.
INSTANTON CALCULATIONS IN N=2 SUPER YANG-MILLS THEORY
Authors: FLUME R. , POGHOSSIAN R.
Published: September 2004

We present a procedure, allowing to derive the coefficients of the Seiberg Witten prepotential of the N=2 Super Yang-Mills theory in the framework of the instanton calculations.
SOME ISSUES IN CONFORMAL FIELD THEORY WITH BOUNDARIES AND CROSSCAPS
Authors: GATO-RIVERA B.
Published: September 2004

This is a brief introduction to the subject of Conformal Field Theory on surfaces with boundaries and crosscaps, which describes the perturbative expansion of open string theory.
THE MODIFIED TETRAHEDRON EQUATION AND ITS SOLUTIONS
Authors: VON GEHLEN G. , PAKULIAK S. , SERGEEV S.
Published: September 2004

A large class of 3-dimensional integrable lattice spin models is constructed. The starting point is an invertible canonical mapping operator [Formula: see text] in the space of a triple Weyl algebra. [Formula: see text] is derived postulating a current branching principle together with a Baxter Z-invariance. The tetrahedron equation for [Formula: see text] follows without further calculation. If the Weyl parameter is taken to be a root of unity, [Formula: see text] decomposes into a matrix conjugation operator R1,2,3 and a c-number functional mapping [Formula: see text]. The operator R1,2,3 satisfies a modified tetrahedron equation (MTE) in which the "rapidities" are solutions of a classical integrable Hirota-type equations. R1,2,3 can be represented in terms of the Bazhanov-Baxter Fermat curve cyclic functions, or alternatively in terms of Gauss functions. The paper summarizes several recent publications on the subject.
ON A CLASS OF INTEGRABLE SYSTEMS CONNECTED WITH GL(N,ℝ)
Authors: GERASIMOV A. , KHARCHEV S. , LEBEDEV D.
Published: September 2004

In this paper we define a new class of the quantum integrable systems associated with the quantization of the cotangent bundle T*(GL(N)) to the Lie algebra [Formula: see text]. The construction is based on the Gelfand-Zetlin maximal commuting subalgebra in [Formula: see text]. We discuss the connection with the other known integrable systems based on T*GL(N). The construction of the spectral tower associated with the proposed integrable theory is given. This spectral tower appears as a generalization of the standard spectral curve for an integrable system.
A NOTE ON THE DYONIC D6-BRANE
Authors: GÓMEZ C. , MANJARÍN J. J.
Published: September 2004

We study the dyon electric charge of D6-branes as eleven dimensional KK-monopoles. We observe that the dyon charge is intimately related with the existence of gauge connections and antisymmetric fields on the brane world-volume.
ON THE QUANTUM RUIJSENAARS MODEL, SOME QUANTUM HOMOGENEOUS SPACES AND HECKE ALGEBRAS
Authors: IORGOV N.
Published: September 2004

The aim of the article is to derive in the explicit form the radial components of Casimir elements of Uq( gl n) corresponding to a quantum analogue of the homogeneous space GL (n)/ SO (n). They coincide with the Macdonald–Ruijsenaars difference operators (MRDOs), if one starts from a special set of Casimir elements from the center of Uq( gl n). The derivation is essentially based on Cherednik's approach to MRDOs by means of affine Hecke algebras. From the other side, MRDOs coincide with commuting Hamiltonians of quantum trigonometric n-particle Ruijsenaars model.
BRST OPERATOR FOR QUANTUM LIE ALGEBRAS: EXPLICIT FORMULA
Authors: ISAEV A. P. , OGIEVETSKY O.
Published: September 2004

We continue our study of quantum Lie algebras, an important class of quadratic algebras arising in the Woronowicz calculus on a quantum group. Quantum Lie algebras are generalizations of Lie (super)algebras. Many notions from the theory of Lie (super)algebras admit "quantum" analogues. In particular, there is a BRST operator Q(Q2=0) which generates the differential in the Woronowicz theory and gives information about (co)homologies of quantum Lie algebras. In our previous papers a recurrence relation for the operator Q for quantum Lie algebras was given. Here we solve this recurrence relation and obtain an explicit formula for the BRST operator.
CORRELATION FUNCTIONS OF THE XXZ SPIN-½ HEISENBERG CHAIN: RECENT ADVANCES (REVIEW)
Authors: KITANINE N. , MAILLET J. M. , SLAVNOV N. A. , TERRAS V.
Published: September 2004

We review some recent advances in the computation of exact correlation functions of the XXZ-½ Heisenberg chain. We first give a general introduction to our method which is based on the algebraic Bethe ansatz and the resolution of the quantum inverse scattering problem, leading in particular to multiple integral representations for the correlation functions. Then we describe recently obtained compact formulas for the spin-spin correlation functions of the XXZ-½ Heisenberg chain. We outline how this leads to several explicit results including the known two point functions in the limit of free fermions, the so-called emptiness formation probability at anisotropy Δ=1/2 and its large distance asymptotic behaviour in the massless phase of the model.
PDEs FOR ISING CORRELATION FUNCTIONS ON THE CYLINDER
Authors: LISOVYY O.
Published: September 2004

In this note, I review some recent results concerning spin-spin Ising correlators on a cylinder: lattice form factor expansions, a scaling limit and nonlinear differential equations. In particular, the pair correlation function is shown to satisfy the same three PDEs of the fourth order in the paramagnetic and ferromagnetic phase. I derive determinant representations of these equations and their multilinear Hirota form. I also conjecture an overdetermined system of PDEs, related to the isomonodromy problem for the Dirac equation on the cylinder, for which n-point functions of the Ising model should give a solution.
NEW SOLVABLE MATRIX INTEGRALS
Authors: YU. ORLOV A.
Published: September 2004

We generalize the Harish-Chandra-Itzykson-Zuber and certain other integrals (the Gross-Witten integral, the integrals over complex matrices and the integrals over rectangle matrices) using a notion of the tau function of the matrix argument. In this case one can reduce multi-matrix integrals to integrals over eigenvalues, which in turn are certain tau functions. We also consider a generalization of the Kontsevich integral.
FREE FIELD APPROACH TO D-BRANES IN N=2 SUPERCONFORMAL MINIMAL MODELS
Authors: PARKHOMENKO S. E.
Published: September 2004

The approach to construction of D-branes in the N=2 superconformal minimal models based on a free-field realization of the N=2 super-Virasoro algebra unitary modules is represented.
RECENT PROGRESS IN LIOUVILLE FIELD THEORY (REVIEW)
Authors: PONSOT B.
Published: September 2004

An explicit construction for the monodromy of the Liouville conformal blocks in terms of Racah-Wigner coefficients of the quantum group [Formula: see text] is proposed. As a consequence, crossing-symmetry for four point functions is analytically proven, and the expression for the correlator of three boundary operators is obtained.
MONODROMY OF SOLUTIONS OF THE KNIZHNIK-ZAMOLODCHIKOV EQUATION: SL(2)k WZNW MODEL
Authors: PONSOT B.
Published: September 2004

Three explicit and equivalent representations for the monodromy of the conformal blocks in the non compact SL(2)k WZNW model are proposed in terms of the same quantity computed in Liouville field theory.
THERMAL BEHAVIOR INDUCED BY VACUUM POLARIZATION ON CAUSAL HORIZONS IN COMPARISON WITH THE STANDARD HEAT BATH FORMALISM
Authors: SCHROER B.
Published: September 2004

Modular theory of operator algebras and the associated KMS property are used to obtain a unified description for the thermal aspects of the standard heat bath situation and those caused by quantum vacuum fluctuations from localization. An algebraic variant of lightfront holography reveals that the vacuum polarization on wedge horizons is compressed into the lightray direction. Their absence in the transverse direction is the prerequisite to an area (generalized Bekenstein-) behaviour of entropy-like measures which reveal the loss of purity due to restrictions to wedges and their horizons. Besides the well-known fact that localization-induced (generalized Hawking-) temperature is fixed by the geometric aspects, this area behaviour (versus the standard volume dependence) constitutes the main difference between localization-caused and standard thermal behaviour.
THE ELEMENTARY EXCITATIONS OF THE BCS MODEL IN THE CANONICAL ENSEMBLE
Authors: SIERRA G. , ROMÁN J. M. , DUKELSKY J.
Published: September 2004

We summarize previous works on the exact ground state and the elementary excitations of the exactly solvable BCS model in the canonical ensemble. The BCS model is solved by Richardson equations, and, in the large coupling limit, by Gaudin equations. The relationship between this two kinds of solutions is used to classify the excitations.
BAXTER EQUATIONS AND DEFORMATION OF ABELIAN DIFFERENTIALS
Authors: SMIRNOV F. A.
Published: September 2004

In this paper the proofs are given of important properties of deformed Abelian differentials introduced earlier in connection with quantum integrable systems. The starting point of the construction is the Baxter equation. In particular, we prove the Riemann bilinear relation. The duality plays an important role in our consideration. The classical limit is considered in details.
TRIGONOMETRIC DEGENERATION AND ORBIFOLD WESS-ZUMINO-WITTEN MODEL I
Authors: TAKEBE T.
Published: September 2004

Trigonometric degeneration of the Baxter-Belavin elliptic r matrix is described by the degeneration of the twisted WZW model on elliptic curves. The spaces of conformal blocks and conformal coinvariants of the degenerate model are factorised into those of the orbifold WZW model.
A LECTURE ON THE LIOUVILLE VERTEX OPERATORS (REVIEW)
Authors: TESCHNER J.
Published: September 2004

We reconsider the construction of exponential fields in the quantized Liouville theory. It is based on a free-field construction of a continuous family or chiral vertex operators. We derive the fusion and braid relations of the chiral vertex operators. This allows us to simplify the verification of locality and crossing symmetry of the exponential fields considerably. The calculation of the matrix elements of the exponential fields leads to a constructive derivation of the formula proposed by Dorn/Otto and the brothers Zamolodchikov.
ON THE RELATION BETWEEN QUANTUM LIOUVILLE THEORY AND THE QUANTIZED TEICHMÜLLER SPACES
Authors: TESCHNER J.
Published: September 2004

We review both the construction of conformal blocks in quantum Liouville theory and the quantization of Teichmüller spaces as developed by Kashaev, Checkov and Fock. In both cases one assigns to a Riemann surface a Hilbert space acted on by a representation of the mapping class group. According to a conjecture of H. Verlinde, the two are equivalent. We describe some key steps in the verification of this conjecture.
A FAMILY OF FACE MODELS RELATED TOZN-SYMMETRIC VERTEX MODEL OF BELAVIN
Authors: YAMADA Y.
Published: September 2004

We present face-type elliptic solutions to the Yang-Baxter equation. They have 2N-2 real parameters. When specializing them to definite values, we recover the various models so far known. The intertwining relation between the face models above and the ZN-symmetric vertex model of Belavin is also given.
HIGHER EQUATIONS OF MOTION IN LIOUVILLE FIELD THEORY
Authors: ZAMOLODCHIKOV AL.
Published: September 2004

An infinite set of the operator-valued relations in the Liouville field theory is established. These relations are enumerated by a pair of positive integers (m, n), the first (1,1) representative being the usual Liouville equation of motion. The relations are proven in the framework of conformal field theory on a basis of the exact structure constants in the Liouville operator product expansions. Possible applications in 2D gravity are discussed.
BRST COHOMOLOGICAL RESULTS ON THE MASSLESS TENSOR FIELD WITH THE MIXED SYMMETRY OF THE RIEMANN TENSOR
Authors: BIZDADEA C. , CIOBÎRCĂ C. C. , CIOROIANU E. M. , SALIU S. O. , SĂRARU S. C.
Published: September 2004

The basic BRST cohomological properties of a free, massless tensor field with the mixed symmetry of the Riemann tensor are studied in detail. It is shown that any non-trivial co-cycle from the local BRST cohomology group can be taken to stop at antighost number three, its last component belonging to the cohomology of the exterior longitudinal derivative and containing non-trivial elements from the (invariant) characteristic cohomology.
SURFACE HOLONOMY AND GAUGE 2-GROUP
Authors: LAHIRI AMITABHA
Published: September 2004

Just as point objects are parallel transported along curves, giving holonomies, string-like objects are parallel transported along surfaces, giving surface holonomies. The composition of these surfaces correspond to products in a category theoretic generalization of the gauge group, called a 2-group. I consider two different ways of constructing surface holonomies, one by using a pair of one- and two-form connections, and another by using a pair of one-form connections. Both procedures result in the structure of a 2-group.
ON THE STRUCTURE OF THE SPACE OF GENERALIZED CONNECTIONS
Authors: VELHINHO J. M.
Published: September 2004

We give a modern account of the construction and structure of the space of generalized connections, an extension of the space of connections that plays a central role in loop quantum gravity.
SYMPLECTIC REDUCTION FOR YANG–MILLS ON A CYLINDER
Authors: SENGUPTA AMBAR N.
Published: September 2004

An account of the Lagrangian and Hamiltonian dynamics of the pure Yang–Mills system is presented. This framework is applied to the case of (1+1)-dimensional cylindrical spacetime. Hamiltonian dynamics on the space of connections over a circle is often identified with dynamics on the cotangent bundle of the gauge group by means of the holonomy. In support of this procedure we show that the symplectic structure for Hamiltonian dynamics for connections on a circle is identifiable with the natural symplectic structure on the cotangent bundle of the gauge group.
GRIBOV PROBLEM FOR GAUGE THEORIES: A PEDAGOGICAL INTRODUCTION
Authors: ESPOSITO GIAMPIERO , PELLICCIA DIEGO N. , ZACCARIA FRANCESCO
Published: September 2004

The functional-integral quantization of non-Abelian gauge theories is affected by the Gribov problem at non-perturbative level: the requirement of preserving the supplementary conditions under gauge transformations leads to a nonlinear differential equation, and the various solutions of such a nonlinear equation represent different gauge configurations known as Gribov copies. Their occurrence (lack of global cross-sections from the point of view of differential geometry) is called Gribov ambiguity, and is here presented within the framework of a global approach to quantum field theory. We first give a simple (standard) example for the SU(2) group and spherically symmetric potentials, then we discuss this phenomenon in general relativity, and recent developments, including lattice calculations.
A REPORT ON GAUGE INVARIANT FORMS AND VARIATIONAL PROBLEMS ON THE BUNDLE OF CONNECTIONS OF A PRINCIPAL U(1)-BUNDLE AND ON ASSOCIATED VECTOR BUNDLES
Authors: CASTRILLÓN LÓPEZ M. , MUÑOZ MASQUÉ J.
Published: September 2004

Basic results on gauge invariance of differential forms on the bundle of connections of an arbitrary principal U(1)-bundle and its associated bundles, are reviewed in terms of the underlying geometry to such bundles, within the framework of classical electromagnetism.
A BOUNDARY VALUE PROBLEM FOR MONOPOLES OVER A 3-DIMENSIONAL DISK
Authors: MARINI ANTONELLA
Published: September 2004

In this paper we prove the existence of a smooth minimum for the Yang–Mills–Higgs functional over a disk in 3 dimensions among those configurations with monopoles with prescribed degree, which are covariant constant at the boundary. These boundary conditions come essentially from a 4-dimensional generalized Neumann problem for the pure Yang–Mills functional and dimensional reduction. This problem is well-posed only as a gauge theory in dimension 3. It extends analogous results on Ginzburg–Landau vortices in 2 dimensions.
GEOMETRICAL ASPECTS OF BRST COHOMOLOGY IN AUGMENTED SUPERFIELD FORMALISM
Authors: MALIK R. P.
Published: September 2004

In the framework of augmented superfield approach, we provide the geometrical origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST charges and a non-nilpotent bosonic charge. Together, these local and conserved charges turn out to be responsible for a clear and cogent definition of the Hodge decomposition theorem in the quantum Hilbert space of states. The above charges owe their origin to the de Rham cohomological operators of differential geometry which are found to be at the heart of some of the key concepts associated with the interacting gauge theories. For our present review, we choose the two (1+1)-dimensional (2D) quantum electrodynamics (QED) as a prototype field theoretical model to derive all the nilpotent symmetries for all the fields present in this interacting gauge theory in the framework of augmented superfield formulation and show that this theory is a unique example of an interacting gauge theory which provides a tractable field theoretical model for the Hodge theory.
ON THE GAUGE NATURAL STRUCTURE OF MODERN PHYSICS
Authors: FATIBENE L. , FERRARIS M. , FRANCAVIGLIA M.
Published: September 2004

We review the notion of a gauge natural theory and discuss in particular its role in implementing the very basic principles of any reasonable fundamental physical interaction. Conservation laws are investigated in this general framework by means of Nöther theorem together with the theory of superpotentials for conserved currents. Tetrad gravity and Wess–Zumino model interacting with a gravitational field are considered as pedagogical applications of the gauge natural framework.
GAUGE THEORY DEFORMATIONS AND NOVEL YANG–MILLS CHERN–SIMONS FIELD THEORIES WITH TORSION
Authors: ANCO STEPHEN C.
Published: September 2004

A basic problem of classical field theory, which has attracted growing attention over the past decade, is to find and classify all nonlinear deformations of linear abelian gauge theories. The physical interest in studying deformations is to address uniqueness of known nonlinear interactions of gauge fields and to look systematically for theoretical possibilities for new interactions. Mathematically, the study of deformations aims to understand the rigidity of the nonlinear structure of gauge field theories and to uncover new types of nonlinear geometrical structures.

The first part of this paper summarizes and significantly elaborates a field-theoretic deformation method developed in earlier work. Some key contributions presented here are, firstly, that the determining equations for deformation terms are shown to have an elegant formulation using Lie derivatives in the jet space associated with the gauge field variables. Secondly, the obstructions (integrability conditions) that must be satisfied by lowest-order deformations terms for existence of a deformation to higher orders are explicitly identified. Most importantly, a universal geometrical structure common to a large class of nonlinear gauge theory examples is uncovered. This structure is derived geometrically from the deformed gauge symmetry and is characterized by a covariant derivative operator plus a nonlinear field strength, related through the curvature of the covariant derivative. The scope of these results encompasses Yang–Mills theory, Freedman–Townsend theory, and Einstein gravity theory, in addition to their many interesting types of novel generalizations that have been found in the past several years.

The second part of the paper presents a new geometrical type of Yang–Mills generalization in three dimensions motivated from considering torsion in the context of nonlinear sigma models with Lie group targets (chiral theories). The generalization is derived by a deformation analysis of linear abelian Yang–Mills Chern–Simons gauge theory. Torsion is introduced geometrically through a duality with chiral models obtained from the chiral field form of self-dual (2+2) dimensional Yang–Mills theory under reduction to (2+1) dimensions. Field-theoretic and geometric features of the resulting nonlinear gauge theories with torsion are discussed.
TOPICS ON D-BRANE CHARGES WITH B-FIELDS
Authors: MANJARÍN JUAN JOSÉ
Published: September 2004

In this review we show how K-theory classifies RR-charges in type II string theory and how the inclusion of the B-field modifies the general structure leading to the twisted K-groups. Our main purpose is to give an expository account of the physical relevance of K-theory. To do that, we consider different points of view: processes of tachyon condensation, cancellation of global anomalies and gauge fixings. As a field to test the proposals of K-theory, we concentrate on the study of the D6-brane, now seen as a non-abelian monopole.
ROLE OF MARKET BASED INSTRUMENTS IN THE NEW BUSINESS PARADIGM
Authors: AZZOLINI LUCIANO , KHARE ANSHUMAN
Published: September 2004

This paper attempts to develop a prescriptive theory/model for the strategic application of market based policy instruments. The research paper documents the development of command and control regulatory instruments and provides a normative account of their use by businesses for competitive positioning. The paper then reports the development of Market Based Policy Instruments (MBI) and explains their prospective defensive and offensive strategic applications based on Porter's Five Forces model of industry analysis. Finally, a prescriptive model that describes the strategic application of MBI is provided based on the preceding analysis.

It is assumed that successful firms will not shy away or avoid future regulatory instruments but use them to their competitive advantage. That competitive advantage will come from core firm values that emphasize dramatic increases in resource productivity, the elimination of waste, the use of solution-based business models, and reinvestment in the natural capital. The strategies and tactics that will guide the evolution of "laggard" firms into "achiever" and "enviropreneurial" firms is not precisely mapped out, but there are a number of tools, tactics and strategies that firms can use. All of them are applicable depending on the managerial maturity of the firm and its capacity to extend its environmental management practices, strategy and vision throughout its organisation and to its constellation of relationships. Firms looking for unique competitive advantages should consider using market based regulatory instruments to differentiate their products and services to overcome seemingly impossible market entry barriers, reduce operating costs, and turn waste into profit.
Coordinating epidermal growth factor-induced motility promotes efficient wound closure
Authors: Kurten Richard C. , Chowdhury Parag , Sanders Ronald C. , Pittman Laura M. , Sessions Laura W. , Chambers Timothy C. , Lyle Christopher S. , Schnackenberg Bradley J. , Jones Stacie M.
Published: September 2004

Wound healing is a response to injury that is initiated to reconstruct damaged tissue. In skin, reepithelialization involves both epithelial cells and fibroblasts and contributes to the reformation of a barrier between the external environment and internal milieu. Growth factors including epidermal growth factor (EGF) play important roles in promoting this process. In the present studies we employed CV-1 fibroblasts in a tissue culture model of reepithelialization to develop strategies for optimizing wound closure stimulated by EGF. We found that EGF enhanced cell motility within 6–8 h of EGF treatment in serum-free medium but wounds failed to close within 24 h. However, if medium on these cultures was exchanged for medium containing serum, cells pretreated with EGF closed new scrape wounds more rapidly than did cells that were not pretreated. These results indicate that serum factors work in concert with EGF to coordinate cell motility for efficient wound closure. Indeed, EGF enhanced the rate of wound closure in the presence of serum, and this effect also persisted for at least 24 h after EGF was removed. This coordination of EGF-induced cell motility was accompanied by an increase in the transient phosphorylation of ERK1 and ERK2. The persistent effects of EGF were blocked by transient exposure to reversible inhibitors of transcription and translation, indicating that the expression of new proteins mediated this response. We propose that EGF-stimulated CV-1 fibroblast motility is coordinated by a serum component that induces cell-cell adhesive properties consistent with an epithelial phenotype, thereby enhancing the reepithelialization process.
RGD and YIGSR synthetic peptides facilitate cellular adhesion identical to that of laminin and fibronectin but alter the physiology of neonatal cardiac myocytes
Authors: Boateng Samuel Y. , Lateef Syed S. , Mosley William , Hartman Thomas J. , Hanley Luke , Russell Brenda
Published: September 2004

In the mammalian heart, the extracellular matrix plays an important role in regulating cell behavior and adaptation to mechanical stress. In cell culture, a significant number of cells detach in response to mechanical stimulation, limiting the scope of such studies. We describe a method to adhere the synthetic peptides RGD (fibronectin) and YIGSR (laminin) onto silicone for culturing primary cardiac cells and studying responses to mechanical stimulation. We first examined cardiac cells on stationary surfaces and observed the same degree of cellular adhesion to the synthetic peptides as their respective native proteins. However, the number of striated myocytes on the peptide surfaces was significantly reduced. Focal adhesion kinase (FAK) protein was reduced by 50% in cardiac cells cultured on YIGSR peptide compared with laminin, even though β1-integrin was unchanged. Connexin43 phosphorylation increased in cells adhered to RGD and YIGSR peptides. We then subjected the cardiac cells to cyclic strain at 20% maximum strain (1 Hz) for 48 h. After this period, cell attachment on laminin was reduced to ∼50% compared with the unstretched condition. However, in cells cultured on the synthetic peptides, there was no significant difference in cell adherence after stretch. On YIGSR peptide, myosin protein was decreased by 50% after mechanical stimulation. However, total myosin was unchanged in cells stretched on laminin. These results suggest that RGD and YIGSR peptides promote the same degree of cellular adhesion as their native proteins; however, they are unable to promote the signaling required for normal FAK expression and complete sarcomere formation in cardiac myocytes.
Estrogen receptor-β mediates male-female differences in the development of pressure overload hypertrophy
Authors: Skavdahl Maryanne , Steenbergen Charles , Clark James , Myers Page , Demianenko Tracy , Mao Lan , Rockman Howard A. , Korach Kenneth S. , Murphy Elizabeth
Published: September 2004

The goal of this study was to determine the role of estrogen receptor subtypes in the development of pressure overload hypertrophy in mice. Epidemiological studies have suggested gender differences in the development of hypertrophy and heart disease, but the mechanism and the role of estrogen receptor subtypes are not established. We performed transverse aortic constriction (TAC) and sham operations in male and female wild-type (WT) mice and mice lacking functional estrogen receptor-α [α-estrogen receptor knockout (α-ERKO)] and mice lacking estrogen receptor-β (β-ERKO). Body, heart, and lung weights were measured 2 wk postsurgery. WT male mice subjected to TAC showed a 64% increase in the heart weight-to-body weight ratio (HW/BW) compared with sham, and WT males have increased lung weight at 2 wk. WT female mice subjected to TAC showed a 31% increase in HW/BW compared with sham, which was significantly less than their male counterparts and with no evidence of heart failure. α-ERKO females developed HW/BW nearly identical to that seen in WT littermate females in response to TAC, indicating that estrogen receptor-α is not essential for the attenuation of hypertrophy observed in WT females. In contrast, β-ERKO females responded to TAC with a significantly greater increase in HW/BW than WT littermate females. β-ERKO females have lower expression of lipoprotein lipase at baseline than WT or α-ERKO females. These data suggest an important role for estrogen receptor-β in attenuating the hypertrophic response to pressure overload in females.