bluuebunny/crossref_metadata_2025 huggingface dataset:
Imatinib mesylate induces apoptosis in human cholangiocarcinoma cells
Authors: Chiorean Mihnea V. , Guicciardi Maria Eugenia , Yoon Jung‐Hwan , Bronk Steven F. , Kaufmanns Scott H. , Gores Gregory J.
Published: November 2004

Abstract: Background: Cholangiocarcinoma is a highly malignant, usually fatal cancer with limited therapeutic options. Receptor tyrosine kinases contribute to the development and progression of this cancer. The relatively selective tyrosine kinase inhibitor imatinib mesylate (STI‐571 or Gleevec®) has recently been licensed. However, the ability of this drug to inhibit signal transduction and induce apoptosis in human cholangiocarcinoma cells is incompletely studied. Thus, our goal was to examine the ability of STI‐571 to induce apoptosis in KMCH‐1 cells, a human cholangiocarcinoma cell line.

Methods: Apoptosis was assessed morphologically and also biochemically by measuring caspase activity and the mitochondrial membrane potential. STI‐571 induced apoptosis and inhibited growth of KMCH‐1 cells in a time‐ and concentration‐dependent manner. The induction of apoptosis was accompanied by mitochondrial depolarization followed by a 4.5‐fold increase in caspase activation and was abrogated by the pancaspase inhibitor z‐VAD(OMe)‐fmk. Interestingly, cholangiocarcinoma cells do not express detectable PDGFR, c‐Abl or c‐Kit, which are protein kinases known to be directly inhibited by STI‐571. However, a significant decrease in epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK) phosphorylation was observed following treatment with STI‐571. This decrease in EGFR and FAK phosphorylation was associated with a reduction in Akt activity resulting in loss of Mcl‐1, a potent anti‐apoptotic Bcl‐2 family protein.

Conclusions: these results indicate that STI‐571 induces caspase‐dependent apoptosis in a human cholangiocarcinoma cell line and suggest that STI‐571 might warrant further investigation as a possible agent for treatment of human cholangiocarcinoma.
Ca2+‐independent hypoxic vasorelaxation in porcine coronary artery
Authors: Gu Min , Thorne George D. , Wardle Robert L. , Ishida Yukisato , Paul Richard J.
Published: November 2004

To demonstrate a Ca2+‐independent component of hypoxic vasorelaxation and to investigate its mechanism, we utilized permeabilized porcine coronary arteries, in which [Ca2+] could be clamped. Arteries permeabilized with β‐escin developed maximum force in response to free Ca2+ (6.6 μm), concomitant with a parallel increase in myosin regulatory light chain phosphorylation (MRLC‐Pi), from 0.183 ± 0.023 to 0.353 ± 0.019 MRLC‐Pi (total light chain)−1. Hypoxia resulted in a significant decrease in both force (–31.9 ± 4.1% prior developed force) and MRLC‐Pi (from 0.353 to 0.280 ± 0.023), despite constant [Ca2+] buffered by EGTA (4 mm). Forces developed in response to Ca2+ (6.6 μm), Ca2+ (0.2 μm) + GTPγS (1 mm), or in the absence of Ca2+ after treatment with ATPγS (1 mm), were of similar magnitude. Hypoxia also relaxed GTPγS contractures but importantly, arteries could not be relaxed after treatment with ATPγS. Permeabilization with Triton X‐100 for 60 min also abolished hypoxic relaxation. The blocking of hypoxic relaxation after ATPγS suggests that this Ca2+‐independent mechanism(s) may operate through alteration of MRLC‐Pi or of phosphorylation of the myosin binding subunit of myosin light chain phosphatase. Treatment with the Rho kinase inhibitor Y27632 (1 μm) relaxed GTPγS and Ca2+ contractures; but the latter required a higher concentration (10 μm) for consistent relaxation. Relaxations to N2 and/or Y27632 averaged 35% and were not additive or dependent on order. Our data suggest that the GTP‐mediated, Rho kinase‐coupled pathway merits further investigation as a potential site of this novel, Ca2+‐independent O2‐sensing mechanism. Importantly, these results unambiguously show that hypoxia‐induced vasorelaxation can occur in permeabilized arteries where the Ca2+ is clamped at a constant value.
The effects of intracellular Ca2+ on cardiac K+ channel expression and activity: novel insights from genetically altered mice
Authors: Xu Yanfang , Zhang Zhao , Timofeyev Valeriy , Sharma Dipika , Xu Danyan , Tuteja Dipika , Dong Pei Hong , Ahmmed Gias Uddin , Ji Yong , Shull Gary E. , Periasamy Muthu , Chiamvimonvat Nipavan
Published: November 2004

We tested the hypothesis that chronic changes in intracellular Ca2+ (Ca2+i) can result in changes in ion channel expression; this represents a novel mechanism of crosstalk between changes in Ca2+ cycling proteins and the cardiac action potential (AP) profile. We used a transgenic mouse with cardiac‐specific overexpression of sarcoplasmic reticulum Ca2+ ATPase (SERCA) isoform 1a (SERCA1a OE) with a significant alteration of SERCA protein levels without cardiac hypertrophy or failure. Here, we report significant changes in the expression of a transient outward K+ current (Ito,f), a slowly inactivating K+ current (IK,slow) and the steady state current (ISS) in the transgenic mice with resultant prolongation in cardiac action potential duration (APD) compared with the wild‐type littermates. In addition, there was a significant prolongation of the QT interval on surface electrocardiograms in SERCA1a OE mice. The electrophysiological changes, which correlated with changes in Ca2+i, were further corroborated by measuring the levels of ion channel protein expression. To recapitulate the in vivo experiments, the effects of changes in Ca2+i on ion channel expression were further tested in cultured adult and neonatal mouse cardiac myocytes. We conclude that a primary defect in Ca2+ handling proteins without cardiac hypertrophy or failure may produce profound changes in K+ channel expression and activity as well as cardiac AP.
Requirement of JNK2 for Scavenger Receptor A-Mediated Foam Cell Formation in Atherogenesis
Authors: Ricci Romeo , Sumara Grzegorz , Sumara Izabela , Rozenberg Izabela , Kurrer Michael , Akhmedov Alexander , Hersberger Martin , Eriksson Urs , Eberli Franz R. , Becher Burkhard , Borén Jan , Chen Mian , Cybulsky Myron I. , Moore Kathryn J. , Freeman Mason W. , Wagner Erwin F. , Matter Christian M. , Lüscher Thomas F.
Published: November 2004

In vitro studies suggest a role for c-Jun N-terminal kinases (JNKs) in proatherogenic cellular processes. We show that atherosclerosis-prone
ApoE
–/–
mice simultaneously lacking JNK2 (
ApoE
–/–
JNK2
–/–
mice), but not
ApoE
–/–
JNK1
–/–
mice, developed less atherosclerosis than do
ApoE
–/–
mice. Pharmacological inhibition of JNK activity efficiently reduced plaque formation. Macrophages lacking JNK2 displayed suppressed foam cell formation caused by defective uptake and degradation of modified lipoproteins and showed increased amounts of the modified lipoprotein-binding and -internalizing scavenger receptor A (SR-A), whose phosphorylation was markedly decreased. Macrophage-restricted deletion of JNK2 was sufficient to decrease atherogenesis. Thus, JNK2-dependent phosphorylation of SR-A promotes uptake of lipids in macrophages, thereby regulating foam cell formation, a critical step in atherogenesis.
Periodical Cicadas as Resource Pulses in North American Forests
Authors: Yang Louie H.
Published: November 2004

Resource pulses are occasional events of ephemeral resource superabundance that occur in many ecosystems. Aboveground consumers in diverse communities often respond strongly to resource pulses, but few studies have investigated the belowground consequences of resource pulses in natural ecosystems. This study shows that resource pulses of 17-year periodical cicadas (
Magicicada
spp.) directly increase microbial biomass and nitrogen availability in forest soils, with indirect effects on growth and reproduction in forest plants. These findings suggest that pulses of periodical cicadas create “bottom-up cascades,” resulting in strong and reciprocal links between the aboveground and belowground components of a North American forest ecosystem.
Natural Killer Cell Signaling Pathways
Authors: Vivier Eric , Nunès Jacques A. , Vély Frédéric
Published: November 2004

Natural killer (NK) cells are lymphocytes of the innate immune system that are involved in the early defenses against foreign cells, as well as autologous cells undergoing various forms of stress, such as microbial infection or tumor transformation. NK cell activation is controlled by a dynamic balance between complementary and antagonistic pathways that are initiated upon interaction with potential target cells. NK cells express an array of activating cell surface receptors that can trigger cytolytic programs, as well as cytokine or chemokine secretion. Some of these activating cell surface receptors initiate protein tyrosine kinase (PTK)–dependent pathways through noncovalent associations with transmembrane signaling adaptors that harbor intracytoplasmic ITAMs (immunoreceptor tyrosine-based activation motifs). Additional cell surface receptors that are not directly coupled to ITAMs also participate in NK cell activation. These include NKG2D, which is noncovalently associated to the DAP10 transmembrane signaling adaptor, as well as integrins and cytokine receptors. NK cells also express cell surface inhibitory receptors that antagonize activating pathways through protein tyrosine phosphatases (PTPs). These inhibitory cell surface receptors are characterized by intracytoplasmic ITIMs (immunoreceptor tyrosine-based inhibition motifs). The tyrosine-phosphorylation status of several signaling components that are substrates for both PTKs and PTPs is thus key to the propagation of the NK cell effector pathways. Understanding the integration of these multiple signals is central to the understanding and manipulation of NK cell effector signaling pathways.
Keeping the Leaves Green Above Us
Authors: Gfeller Aurélie , Farmer Edward E.
Published: November 2004

The plant immune system relies to a great extent on the highly regulated expression of hundreds of defense genes encoding antimicrobial proteins, such as defensins, and antiherbivore proteins, such as lectins. The expression of many of these genes is controlled by a family of mediators known as jasmonates; these cyclic oxygenated fatty acid derivatives are reminiscent of prostaglandins. The roles of jasmonates also extend to the control of reproductive development. How are these complex events regulated? Nearly 20 members of the jasmonate family have been characterized. Some, like jasmonic acid, exist in unmodified forms, whereas others are conjugated to other lipids or to hydrophobic amino acids. Why do so many chemically different forms of these mediators exist, and do individual jasmonates have unique signaling properties or are they made to facilitate transport within and between cells? Key features of the jasmonate signal pathway have been identified and include the specific activation of E3-type ubiquitin ligases thought to target as-yet-undescribed transcriptional repressors for modification or destruction. Several classes of transcription factor are known to function in the jasmonate pathway, and, in some cases, these proteins provide nodes that integrate this network with other important defensive and developmental pathways. Progress in jasmonate research is now rapid, but large gaps in our knowledge exist. Aimed to keep pace with progress, the ensemble of jasmonate Connections Maps at the Signal Transduction Knowledge Environment describe (i) the canonical signaling pathway, (ii) the
Arabidopsis
signaling pathway, and (iii) the biogenesis and structures of the jasmonates themselves.
Impact-Induced Seismic Activity on Asteroid 433 Eros: A Surface Modification Process
Authors: Richardson James E. , Melosh H. Jay , Greenberg Richard
Published: November 2004

High-resolution images of the surface of asteroid 433 Eros revealed evidence of downslope movement of a loose regolith layer, as well as the degradation and erasure of small impact craters (less than ∼100 meters in diameter). One hypothesis to explain these observations is seismic reverberation after impact events. We used a combination of seismic and geomorphic modeling to analyze the response of regolith-covered topography, particularly craters, to impact-induced seismic shaking. Applying these results to a stochastic cratering model for the surface of Eros produced good agreement with the observed size-frequency distribution of craters, including the paucity of small craters.
When the Stress of Your Environment Makes You Go HOG Wild
Authors: Westfall Patrick J. , Ballon Daniel R. , Thorner Jeremy
Published: November 2004

When exposed to increased dissolved solute in their environment (hyperosmotic stress), all eukaryotic cells respond by rapidly activating a conserved mitogen-activated protein kinase cascade, known in budding yeast
Saccharomyces cerevisiae
as the high osmolarity glycerol (HOG) pathway. Intensive genetic and biochemical analysis in this organism has revealed the presumptive osmosensors, downstream signaling components, and metabolic and transcriptional changes that allow cells to cope with this stressful condition. These findings have had direct application to understanding stress sensing and control of transcription by stress-activated mitogen-activated protein kinases in mammalian cells.
Nota Bene: Tricking Our Vision
Authors: Fahrenkamp-Uppenbrink Julia
Published: November 2004

Eyes, Lies and Illusions
. Werner Nekes and Marina Warner, curators. Hayward Gallery, South Bank Centre, London. Through 2 January 2005.
www.hayward.org.uk

Eyes, Lies and Illusions
Drawn from the Werner Nekes Collection. by Laurent Mannoni, Werner Nekes, and Marina Warner. Hayward Gallery, London, 2004. Paper, 240 pp. £24.95. ISBN 1-85332-244-X.

The exhibition combines images and devices drawn from the collection of the German experimental filmmaker Nekes with works by contemporary artists to explore visual deception and perception.
RESOLUTION IN PIXE THIN FILM THICKNESS DETERMINATION
Authors: MIRANDA J. , OLIVER A. , RUIZ F.J. , SANTANA J.M.
Published: November 2004

The resolution of several methods for thin film thickness measurement using PIXE, based on the variation of the proton beam incident energy, is discussed. In order to evaluate the resolution, sputtering of copper films, deposited on aluminum and titanium substrates by argon ions is used. Sputtering yields are obtained through thickness changes, and then compared to other experimental and theoretical values. Good agreement is found, thus confirming the accuracy of PIXE as a method for film thickness determination.
LATTICE SPIN MODELS AND NEW ALGORITHMS — A REVIEW OF MONTE CARLO COMPUTER SIMULATIONS
Authors: BAILLIE CLIVE F.
Published: November 2004

We review Monte Carlo computer simulations of spin models — both discrete and continuous. We explain the phenomenon of critical slowing which seriously degrades the efficiency of standard local Monte Carlo algorithms such as the Metropolis algorithm near phase transitions. We then go onto describe in detail the new algorithms which ameliorate the problem of critical slowing down, and give their dynamical critical exponent values.
PRECISE NUMERICAL DETERMINATION OF THE SUPERCONDUCTING EXPONENT OF PERCOLATION IN THREE DIMENSIONS
Authors: NORMAND J. M. , HERRMANN H. J.
Published: November 2004

We present data obtained on the special purpose computer "Percola" determining the exponent [Formula: see text] of the random mixture of superconducting and normal conducting elements at the percolation threshold. The extrapolation is done for bond and site percolation and gives [Formula: see text] with a correction exponent ω = 1.85 ± 0.20.
LARGE SCALE NEURAL NETWORK SIMULATIONS
Authors: KOHRING G. A.
Published: November 2004

The current state of large scale, numerical simulations of neural networks is reviewed. Hardware and software improvements make it likely that biological size networks, i.e., networks with more than 1010 couplings, can be simulated in the near future. Sample programs for the efficient simulation of a few simple models are presented as an aid to researchers just entering the field.
FEIGIN-FUCHS REPRESENTATIONS OF $A ^{(1)} _n$ AFFINE LIE ALGEBRA AND THE ASSOCIATED PARAFERMIONIC ALGEBRA
Authors: ITO KATSUSHI , KAZAMA YOICHI
Published: November 2004

Feigin-Fuchs representations of [Formula: see text] affine Lie algebra and the associated parafermionic algebra are obtained. The screening charges, essential for analyzing the structure of irreducible modules, are also discussed.
DOUBLE HIGGS BOSON PRODUCTION VIA WW FUSION IN TeV e+e− COLLISIONS
Authors: BARGER V. , HAN T.
Published: November 2004

The production of two standard model Higgs bosons via the WW fusion process e+e− →[Formula: see text] would test the predicted HHH, HWW and HHWW couplings. At TeV energies this fusion cross section dominates over that from e+e− →ZHH and would give significant event rates for mH ≲ 1/2 MZ at high luminosity e+e− colliders. We evaluate the rates and present the dynamical distributions.
THE ROLE OF QUANTIZED 2-DIM. GRAVITY IN STRING THEORY
Authors: DHAR AVINASH , JAYARAMAN T. , NARAIN K. S. , WADIA SPENTA R.
Published: November 2004

We present a formulation of string theory in which the 2-dim. metric is exactly quantized in the framework of SL (2, R) current algebra. In this way we replace the conformal invariance prescription by the principle of reparametrization invariance. The theory is formulated in arbitrary number of dimensions since the usual restriction of fixed matter central charge is not present. As a concrete illustration of our approach, we show that in 25 Euclidean dimensions the usual amplitudes of the 26-dimensional bosonic string theory arise. The extra time-like dimension emerges as a mode of the 2-dim. metric and the gravitational dressing of vertex operators gives rise to their time dependence.
THE MASS OF H-DIBARYON IN AN SU(3) SKYRME MODEL
Authors: LEE HYUN KYU , KIM JOON HA
Published: November 2004

The mass of H-dibaryon is estimated in an SU(3) Skyrme model using the exact diagonalization method. With the parameters determined from the best fit to the B = 1 baryon spectrum, the mass of H-dibaryon is obtained as 1818 MeV.
FINITE TEMPERATURE NÉEL TRANSITION IN CPN−1 MODEL
Authors: ICHINOSE IKUO , YAMAMOTO HISASHI
Published: November 2004

We study in d space-dimensions the finite temperature Néel order transition in CPN−1 model as a low energy effective field theory of the antiferromagnetic Heisenberg model. For d=1 at any temperature and d=2 at any nonzero temperature, long range Néel order (LRNO) disappears, in agreement with the Mermin-Wagner-Coleman theorem. For d=3 in the weak coupling region, LRNO exists below the critical temperature T N (Néel temperature). T N decreases as the interlayer coupling becomes relatively weak compared with that within Cu-O layers.
THE SEARCH FOR DARK MATTER
Authors: CALDWELL DAVID O.
Published: November 2004

The particle constituting probably more than 90% of the mass of the universe is unknown in the Standard Model of particle physics. Non-accelerator experiments, particularly those using Ge and Si detectors, and accelerator experiments, especially at SLC and LEP, have eliminated as dark matter wide classes of candidate particles. Examples are weak isodoublet neutrinos of mass ≳30 eV/c 2, sneutrinos, technibaryons, microcharged shadow matter, and probably Cosmions, which could both be dark matter and solve the solar neutrino problem.
ACTION PRINCIPLE FOR STRINGS IN LESS THAN ONE DIMENSION
Authors: JEVICKI ANTAL , YONEYA TAMIAKI
Published: November 2004

We present a simple action principle for the non-perturbative string theory in less than one dimension. It generates the continuum String equations and the associated KdV flows. Our approach is based on the operator method developed for studying the KP hierarchy.
MIXING EFFECTS OF MIRROR LEPTONS IN e+e− → W+W− AT LEP II
Authors: SINGH SARDAR , NAGAWAT A. K. , SHARMA N. K.
Published: November 2004

The deviations from standard model predictions for the process e+e− → W+W− due to the inclusion of mixing between ordinary and mirror leptons are evaluated for (i) total cross section, (ii) forward-backward asymmetry and (iii) differential cross sections for the production of unpolarized/polarized W's at LEP II [Formula: see text] energy. For the presently known limits on mirror lepton mixings ( sin 2 ψ ≈ 0.02 to 0.06) and heavy mirror neutrinos (m N ≈ 100–300 GeV ), the relative deviations are large (∆ ≈ −2% to −20%). These could possibly allow discerning of mirror lepton mixing effects at LEP II.
CLASSIFICATION OF 2- AND 3-FIELD RATIONAL CONFORMAL FIELD THEORIES
Authors: RIVLIS GIL
Published: November 2004

Using the fact that the fusion algebra of a rational conformal field theory is specified in terms of integers that are related to modular transformation properties, we completely classify 2-field chiral RCFT's. We show that the only possibilities for the non-trivial fusion rule are ϕ × ϕ = 1 or ϕ × ϕ = 1 + ϕ. We reduce the 3-field classification to a set of algebraic equations and solve them in a few cases.
LEADING NON-LOGARITHMIC CONTRIBUTION TO THE ELECTROPENGUIN DIAGRAM AND PHENOMENOLOGY OF KAON DECAYS
Authors: CIUCHINI M. , FRANCO E. , ONOFRIO R.
Published: November 2004

The leading non-logarithmic contribution which arises in the real part of the Wilson coefficient for the electropenguin operator is re-analyzed within the four-flavor effective Hamiltonian. The ratio Γ(K+ → π+e+e−)/Γ(K+ → π0e+νe), the KL → π0e+e− decay rate and the ∆I = 1/2 rule in non-leptonic kaon decays are reconsidered by taking into account both the leading non-logarithmic contribution and the strong corrections in log (Mw/μ)2 up to the next-to-leading order. Their dependence on the QCD parameters is studied and we argue that the inclusion of the strong corrections of order log (mg/μ)2 cannot be neglected.
ULTRAVIOLET BEHAVIOR OF THE INTEGRABLE OFF-CRITICAL NON-UNITARY SERIES M3/q
Authors: CHRISTE P. , MARTINS M. J.
Published: November 2004

We discuss the ultraviolet behavior of the non-unitary M3/q (q = 5, 7) minimal models perturbed by the operator ϕ13. The Thermodynamic Bethe Ansatz is used to compute the central charge and the next higher order corrections in the high temperature expansion of the finite volume ground state energy. The results are in perfect agreement with perturbative calculations. Generalizations of these results are commented on.
ELECTROWEAK INTERACTIONS WITH CHIRAL HYPERCHARGES
Authors: RAJPOOT SUBHASH
Published: November 2004

We consider an extension of the electroweak gauge interactions from SU (2) L × U (1)Y to SU (2) L × U (1) L × U (1) R . This extension is motivated by the observed structure of the quarks and leptons, i.e., they form left-handed doublets and right-handed singlets eigenstates of electroweak interactions. In this new extension, the U (1) R serves only the right-handed singlet fermions. Consistent with the measurements of the mass of the standard massive neutral boson Z0 at the SLAC and CERN colliders and the neutral current couplings involving neutrinos and electrons, the additional massive neutral gauge boson can be as light as a few hundred GeV. The model employs the generalized see-saw mechanism to give masses to all the fermions of the theory.
GAUGE SINGLETS AND THE DIPOLE MOMENT OF THE ELECTRON
Authors: MUKHOPADHYAYA BISWARUP , NANDI SATYANANAYAN
Published: November 2004

It is shown that models containing both SU(2) singlet fermions and a singlet Higgs have interesting effects on the electric dipole moment of the electron. Unlike the neutron dipole moment, there is no QCD suppression in this case. It is thus possible to find useful constraints on models that include both these kinds of singlets.
ON THE QUANTUM R-MATRIX ON A $U_q ({\rm sl} (2, {\mathbb C}))$-MODULE
Authors: YOU HAN-QIN , ZHOU SHANYOU
Published: November 2004

A new method to construct the quantum R-matrix on [Formula: see text] is given in this paper. Using it, the explicit formula of [Formula: see text] has been obtained in several cases.
VALIDITY OF NAKAMURA-KUDO SCALING OF CHARGED PARTICLE PSEUDORAPIDITY DISTRIBUTION IN RELATIVISTIC HEAVY ION INTERACTIONS
Authors: GHOSH DIPAK , MUKHOPADHYAY AMITABHA , SARKAR SHARMILA , SENGUPTA RANJAN , GHOSH ANIT , GHOSH PREMOMOY , ROY JAYA , BASU MADHUMITA
Published: November 2004

This letter reports an analysis of our own emulsion data in terms of charged particle pseudorapidity distribution in the cases of 12 C-Ag/Br , 24 Mg-Ag/Br at 4.5 A GeV/c, and 16 O-Ag/Br at 2.1 A GeV. The data are compared with the analyses using two scaling variables recently proposed by Kenju Mori et al. and Nakamura and Kudo. In all cases the data show a remarkable agreement with the scaling behavior of Nakamura and Kudo. The data obtained for 16 O + AgBr interactions at 14.6 A GeV, 60 A GeV, and 200 A GeV are also in favor of the Nakamura-Kudo scaling.
CANONICAL QUANTIZATION OF A RIGID PARTICLE
Authors: ISBERG J. , LINDSTRÖM U. , NORDSTRÖM H. , GRUNDBERG J.
Published: November 2004

We quantize a rigid particle with a rigidity term proportional to the square of the extrinsic curvature of the particle's world-line using the Dirac-Bergmann scheme. Problems concerning higher order derivatives and second class constraints are avoided by using an action with an auxiliary field and one extra gauge symmetry. We find a spectrum with integer spin states only.
SOLUTIONS FOR THE TWO-BODY DIRAC EQUATION WITH PHENOMENOLOGICAL INTERACTIONS
Authors: FERREIRA P. LEAL , GALEÃO A. P.
Published: November 2004

Solutions for the relativistic two-body Dirac equation with an enlarged class of phenomenological potentials including several Breit-type terms are investigated for the general case of unequal masses. The solutions corresponding to definite total angular momentum and parity are shown to fall into two classes, each being obtained by solving a system of four coupled first order differential equations. The reduction of this system to a pair of coupled Schrödinger-type equations and the particular case of equal masses are also discussed.
PARAFERMIONS AND SUPEROPERATOR-MEDIATED QUANTUM SYSTEM REDUCTION
Authors: MERKEL U.
Published: November 2004

In this letter we present a nonlinear version of the superoperator formalism and show that it takes an active part in the reduction of quantum-mechanical systems of a given size to other, in a specifiable sense, 'smaller' ones. The class of systems considered is the (para-) supersymmetric one.
HIGHER GENUS WAVEFUNCTION OF ANYON SYSTEM
Authors: MAHARANA JNANADEVA , PANDA SUDHAKAR
Published: November 2004

A method is proposed for constructing the wavefunction of anyons on Riemann surfaces of arbitrary genus. This has been carried out in the framework of computing the correlation function of the chiral vertex operators, involving free scalar fields, with appropriate external momenta. Our technique, as a check, reproduces the already known anyonic wavefunction on the sphere as well as that on the torus.
QUATERNIONIC SIX-DIMENSIONAL (SUPER)TWISTOR FORMALISM AND COMPOSITE (SUPER)SPACES
Authors: LUKIERSKI J. , NOWICKI A.
Published: November 2004

We extend by real quaternions the D=4 twistor and supertwistor formalism. The notion of quaternionic D=4 composite superspaces is considered. The construction of D=6 real composite space-time variables as well as D=6 real composite superspaces is shown.
MULTIPLICATIVE RENORMALIZABILITY AND SELF-CONSISTENT TREATMENTS OF THE SCHWINGER-DYSON EQUATIONS
Authors: BROWN N. , DOREY N.
Published: November 2004

Many approximations to the Schwinger-Dyson equations place constraints on the renormalization constants of a theory. The requirement that the solutions to the equations be multiplicatively renormalizable also places constraints on these constants. Demanding that these two sets of constraints be compatible is an important test of the self-consistency of the approximations made. We illustrate this idea by considering the equation for the fermion propagator in massless quenched QED, checking the consistency of various approximations.
VERTEX OPERATORS AND QUANTUM HALL EFFECT
Authors: FUBINI SERGIO
Published: November 2004

F.V. vertex operator which allows a consistent bosonization of fermions, bosons and anyons is shown. It thus plays an essential role in the general theory of Fractional Quantum Hall Effect (F.Q.H.E.).
SELF-DUALITY AND GENERALIZED KdV FLOWS
Authors: BAKAS IOANNIS , DEPIREUX DIDIER A.
Published: November 2004

We obtain the (N+1)-th flow of the generalized (N–1)-KdV hierarchy from self-dual Yang-Mills equations with gauge group SL(N) and space-time signature (2, 2). The dimensional reduction is performed by using a pair of orthogonal Killing vector fields (one time-like and one null) and we generalize previous results by Mason and Sparling to N≥2. We illustrate our method with explicit examples and determine the form of the self-dual solutions for N=2, 3, 4. Applications of this formalism and its possible generalizations are also discussed briefly.
ON T-VIOLATION IN MATTER NEUTRINO OSCILLATIONS
Authors: TOSHEV S.
Published: November 2004

We continue the investigation of possible T-violating effects in three-neutrino oscillations in matter. Intriguingly simple analytical expression for the experimentally measurable quantity [Formula: see text] (t) is derived.
EVALUATION OF A CLASS OF THE LAPLACE OPERATOR DETERMINANTS CONNECTED WITH QUANTUM GEOMETRY OF p-BRANES
Authors: BYTSENKO A.A. , GONCHAROV YU. P.
Published: November 2004

We evaluate the determinants of Laplacians acting in real line bundles over the manifolds Tp−1×H2/Γ, T=S1, H2/Γ is a compact Riemannian surface of genus g>1. Such determinants may be important in building quantum geometry of closed p-branes. The evaluation is based on the Selberg trace formula for compact Riemannian surfaces.
ELASTIC AND INELASTIC PROTON MULTIPLE SCATTERING ON 12C AND 16O NUCLEI
Authors: BEREZHNOY YU. A. , MIKHAILYUK V.P. , PILIPENKO V.V.
Published: November 2004

The elastic and inelastic scattering polarization observables of the 800 MeV protons on 12C and 16O nuclei are calculated on the basis of the multiple diffraction scattering theory. It was shown that the results of the calculations for elastic p-12C and p-16O scattering by the α-cluster model with dispersion are in a better agreement with the experimental data than those with the single-particle nucleon density.
SCALING OF MULTIPLICITY DISTRIBUTIONS AND COLLISION DYNAMICS IN e+e− AND pp INTERACTIONS
Authors: GAŹDZICKI M. , SZWED R. , WROCHNA G. , WRÓBLEWSKI A.K.
Published: November 2004

The scaling properties of multiplicity distributions for e+e− and pp collisions are summarized. It is shown that in both cases the distributions have a lognormal shape.

Possible relations between e+e− and pp collision dynamics are discussed in a framework scaling properties of multiplicity distributions. The form of the energy dependence of mean multiplicity is obtained as a consequence of the multiplicity scaling.
ANOMALOUS DIMENSIONS IN TURBULENCE
Authors: MIGDAL ALEXANDER A.
Published: November 2004

A time-independent field theoretical framework for turbulence is suggested, based upon a variational principle for a stationary solution of the Fokker—Planck equation. We obtain a functional equation for the effective Action of this spatial field theory and investigate its general properties and some numerical solutions. The equation is completely universal, and allows for the scale invariant solutions in the inertial range. The critical indices are not fixed at the kinematical level, but rather should be found from certain eigenvalue conditions, as in the field theory of critical phenomena. Unlike the Wyld field theory, there are no divergences in our Feynman integrals, due to some magic cancellations. The simplest possible Gaussian approximation yields crude but still reasonable results (there are deviations from Kolmogorov scaling in 3 dimensions, but at 2.7544 dimensions it would be exact). Our approach allows us to study some new problems, such as spontaneous parity breaking in 3d turbulence. It turns out that with the appropriate helicity term added to the velocity correlation function, logarithmic infrared divergences arise in our field theory which effectively eliminates these terms. In order to build a quantitative theory of turbulence, one should consider more sophisticated Ansatz for the effective Action, which would require serious numerical work.
HYBRID-TYPE MODEL AND THE DIRECT SUM OF QUANTUM GROUPS
Authors: DEGUCHI TETSUO , FUJII AKIRA
Published: November 2004

We present the quantum formal group derived from the hybrid-type model. The quantum group structure is given by the direct sum of several quantum groups. We show that by applying the quantum inverse scattering method to the direct sum of the several quantum groups we can reconstruct the hybrid-type model.
THREE-DIMENSIONAL FOUR-FERMION (VECTOR) ⊗ (VECTOR) MODEL IS RENORMALIZABLE AND ULTRAVIOLET FINITE
Authors: KRASNIKOV N.V. , KYATKIN A.B.
Published: November 2004

We show that the four-fermion (vector) ⊗ (vector) model is renormalizable in the framework of the 1/N expansion and moreover it is ultraviolet finite.
INTERACTIONS AND SCATTERING IN d = 1 STRING THEORY
Authors: MANDAL GAUTAM , SENGUPTA ANIRVAN M. , WADIA SPENTA R.
Published: November 2004

We discuss two results: (i) we calculate the two-point function of the density fluctuations to [Formula: see text] in the fermonic formulation of the d = 1 string theory and compare with the [Formula: see text] result from the candidate collective field Hamiltonian. The latter result is divergent, showing the inequivalence of the two theories. We find out the corrections to the collective field Hamiltonian (both in the form of infinite counterterms and additional finite pieces) needed to match with the fermion theory. (ii) We study tree-level scattering processes between bosons due to the localized interaction near the boundary (in a region of order [Formula: see text]). The reflection problem at the boundary is treated by an analytic continuation of the time-of-flight variable.
THE MODULI SPACE OF SUPERCONFORMAL INSTANTONS IN SIGMA MODELS
Authors: MONASTYRSKY M. I. , NATANZON S. M.
Published: November 2004

A new approach to instantons in supersymmetrical 2-dimensional sigma models is discussed. In this approach superinstantons are characterized as the superconformal maps of a physical space into the isotopic (target) space. We consider a special case of the supersphere with punctures. New topological invariants as the number of the so-called fermionic points appear in this case. We also analyze the structure of the moduli space of superinstantons within this framework.
SUPERHEAVY TOPONIUM ψt(1−−) BOUND VIA HIGGS–BOSON EXCHANGE
Authors: INAZAWA H. , MORII T. , MORISHITA J. , MUKHERJEE S. N.
Published: November 2004

A possible existence of superheavy toponium ψt(1−−) bound via Higgs–boson exchange is discussed in the framework of two Higgs-doublet model. It is pointed out that the Drell ratio distribution is a very good measure of Higgs–boson exchange because of its special decay property of the ψt(1−−).
UPDATED BOUNDS ON HIGGS TRIPLET VACUUM EXPECTATION VALUES AND THE TREE-LEVEL ρ PARAMETER FROM RADIATIVE CORRECTIONS
Authors: RIZZO THOMAS G.
Published: November 2004

We obtain 95% C. L. upper limits on the ratio of triplet to doublet vacuum expectation values in two extended electroweak models from radiative corrections. We use as input data from LEP, the Tevatron, the CERN [Formula: see text] colliders, and various low-energy experiments such as atomic parity-violation and deep inelastic scattering. The analysis includes the incorporation of leading two-loop electroweak contributions to ∆r and ρ arising from heavy top quarks and Higgs bosons, the Consoli–Hollik–Jegerlehner resummation technique, and QCD corrections to the hadronic partial widths of the Z using the new value for the (αs/π)3 coefficient. Our limits are found to be only mildly sensitive to the top quark and Higgs boson masses and somewhat stronger than those obtained previously. Our results are then generalized to bounds on the allowed value of the tree-level ρ parameter.
CONSEQUENCES OF SOLITONIC VACUUM IN A TWO-HIGGS MODEL
Authors: VILJA I.
Published: November 2004

The properties and effects of a solitonic vacuum sector in the electroweak theory with two scalar doublets is studied. It is pointed out that the solitonic sector may give a considerable negative contribution to the cosmological constant. The soliton-fermion and soliton-gauge boson interactions are analyzed in a semiclassical level and it is argued that these interactions are usually very weak.
A METHOD TO CALCULATE $Q_{\rm BRST}^2$ IN THE PATH-INTEGRAL QUANTIZATION
Authors: IGARASHI Y. , KUBO J. , SAKAKIBARA S.
Published: November 2004

The BRST transformation of wave functional represented in a finite-time path-integral is analyzed in the generalized Hamiltonian formalism of Batalin, Fradkin, and Vilkovisky, and it is shown that the anomalous Schwinger terms that appear in the nilpotency condition and the time development of BRST charge Q BRST can be directly calculated in the path-integral quantization. We explicitly compute [Formula: see text] in a chiral Yang–Mills theory. The method is general in character, and can easily be applied to other theories.
PHOTOPRODUCTION OF GRAVITONS AND DILATONS IN AN EXTERNAL ELECTROMAGNETIC FIELD
Authors: LONG HOANG NGOC , HUONG LE KHAC
Published: November 2004

An attempt is made to present experimental predictions of the Kaluza-Klein based models. We consider the creation of gravitons and dilatons by photons in an external electromagnetic field, namely in the electric field of a flat condenser and in the static magnetic field. The relation between the cross-sections of these two processes is given. A numerical evaluation shows that in the present technical scenario the creation of high frequency gravitons and dilatons may be indirectly observable.
WHEELER WORMHOLES AND TOPOLOGY CHANGE: A MINISUPERSPACE ANALYSIS
Authors: VISSER MATT
Published: November 2004

Wheeler's wormholes are analyzed within the context of a particular minisuperspace approximation. In this approximation the Wheeler-DeWitt equation describing a wormhole is exactly solvable and the quantum mechanical wavefunction of a wormhole can be explicitly exhibited. Calculation shows that the throat of a minisuperspace Wheeler wormhole is stabilized against collapse by quantum mechanical effects: The radius of the throat has an expectation value of order the Planck length. Implications of this result with respect to the process of quantum gravitational topology change are discussed. In particular it is argued that the putative stability of minisuperspace Wheeler wormholes—if it persists beyond the minisuperspace approximation—might serve to suppress fluctuations in topology.
MACROSCOPIC BOUNDARIES AND THE WAVE FUNCTION OF THE UNIVERSE IN THE c=-2 MATRIX MODEL
Authors: EDWARDS JONATHAN D. , KLEBANOV IGOR R.
Published: November 2004

Using a matrix model, we calculate sums over surfaces with macroscopic boundaries of fixed lengths in two-dimensional gravity coupled to a pair of anti-commuting scalar fields with c=-2. For n boundaries, the answer depends only on the sum of their lengths and is given explicitly in terms of Bessel functions to all orders of the genus expansion. For n=1, this defines the Hartle-Hawking ground state wave function of the universe, which is shown to satisfy the minisuperspace Wheeler–De Witt equation with a boundary condition imposed at small geometries.
MATRIX MODELS AS INTEGRABLE SYSTEMS: FROM UNIVERSALITY TO GEOMETRODYNAMICAL PRINCIPLE OF STRING THEORY
Authors: GERASIMOV A. , MAKEENKO YU. , MARSHAKOV A. , MIRONOV A. , MOROZOV A. , ORLOV A.
Published: November 2004

Matrix models are equivalent to certain integrable theories, partition functions being equal to certain τ-functions, i.e., the section of determinant bundles over infinite-dimensional Grassmannian. These τ-functions are evaluated at the points of Grassmannian, where high symmetry arises. In the case of one-matrix models the symmetry is isomorphic to Borel subgroup of a Virasoro group. The orbits of the group are in one-to-one correspondence with the types of "multicritical" behavior in the continuum limit. Interrelation between τ-functions in different models and their continuum limit is discussed in some details. We also discuss the implications for dynamical interpolation between various string models (CFT's), to be described in terms of geometrical quantization of Fairlie-like [Formula: see text]-algebras.
STABILITY OF THE TOP QUARK MASS IN SUPERSYMMETRIC TOP CONDENSATE MODELS
Authors: CLARK T. E. , LOVE S. T. , TER VELDHUIS W. T. A.
Published: November 2004

The top quark mass prediction in supersymmetric top condensate models is found to be insensitive to the inclusion of the effects of higher dimensional operators. For associated coefficients of characteristically moderate strength, the supersymmetric renormalization group trajectories are strongly focused to the infrared quasi-fixed point of the top Yukawa coupling constant.
$B^0_d - \bar{B}^0_d$ MIXING, MIT BAG MODEL AND TOP QUARK
Authors: NAIK S. K. , Singh L. P.
Published: November 2004

We carry out hydronic matrix element computation in [Formula: see text] mixing using MIT bag model and find it to suggest the evidence for existence of top quark with mass mt ࣡ 225 GeV . The analog of "long lived" state is found to be massive than the "short lived" state in [Formula: see text] system.
INCLUSIVE AND SEMI-INCLUSIVE HADRON INTERACTIONS AT ISR AND COLLIDER ENERGIES
Authors: GIACOMELLI G.
Published: November 2004

A review is made of the experimental results obtained in low-pt particle production experiments at the CERN-ISR, in particular those obtained with the Split Field Magnet Detector. Selected low-pt results from the CERN and Fermilab [Formula: see text] colliders are also discussed. The data are interpreted with the help of a number of models.
HAUSDORFF DIMENSION OF CONTINUOUS POLYAKOV’S RANDOM SURFACES
Authors: DISTLER JACQUES , HLOUSEK ZVONIMIR , KAWAI HIKARU
Published: November 2004

In this paper we compute exactly, using the scaling properties of the Liouville theory, the Hausdorff dimension of the continuous random surfaces of Polyakov for D≤1. We find that for D<1, the mean square size of the surface grows as a logarithm of the area of the surface as well as the area of the surface raised to a power, the power being minus the string susceptibility. For D=1 the behavior changes, as expected, because the model undergoes a phase transition. In that case we find that the mean square size of the surface behaves as a combination of terms that grow as a logarithm of the area as well as its square, in qualitative agreement with the results of numerical experiments in discrete models.
Λ0 POLARIZATION IN HADRON-NUCLEON, HADRON-NUCLEUS AND NUCLEUS-NUCLEUS INTERACTIONS
Authors: PANAGIOTOU APOSTOLOS D.
Published: November 2004

We discuss the experimental systematic characteristics of the Λ0 polarization observed in hadron-nucleon, hadron-nucleus, and nucleus-nucleus interactions. The current theoretical framework is reviewed and compared with the experimental data. We also discuss the effects of QCD deconfinement on the transverse and longitudinal polarization in nucleus-nucleus interactions and the possibility of using these effects as signals of quark matter formation.
GAUGE FIXING TOPOLOGICAL YANG-MILLS
Authors: MYERS ROBERT
Published: November 2004

We examine two methods of fixing the gauge symmetry in Witten’s topological Yang-Mills theory. We find that both procedures produce the same nontrivial correlation functions. Our results also apply to other topological field theories, such as topological gravity.
COSMIC STRINGS, HOT DARK MATTER AND THE LARGE-SCALE STRUCTURE OF THE UNIVERSE
Authors: BRANDENBERGER ROBERT H. , PERIVOLAROPOULOS LEANDROS , STEBBINS ALBERT
Published: November 2004

A review of recent results on large-scale structure and galaxy formation in a model with hot dark matter and cosmic strings is given. With cosmic strings seeding perturbations, many of the arguments against hot dark matter disappear. It is shown that spherical accretion about loops leads to dark matter haloes with flat velocity rotation curves. Velocity perturbations due to wakes behind long, moving strings lead to a network of planar overdensities with a distinguished scale of slightly less than 40×40 Mpc2. If the mass per unit length μ exceeds a certain bound, then the wakes become nonlinear by the present time. In this case, their thickness can be calculated.
AGAINST MANY-WORLDS INTERPRETATIONS
Authors: KENT ADRIAN
Published: November 2004

This is a critical review of the literature on many-worlds interpretations, MWI, with arguments drawn partly from earlier critiques by Bell and Stein. The essential postulates involved in various MWI are extracted, and their consistency with the evident physical world is examined. Arguments are presented against MWI proposed by Everett, Graham and DeWitt. The relevance of frequency operators to MWI is examined; it is argued that frequency operator theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves provide a probability interpretation for quantum mechanics, and thus neither support existing MWI nor would be useful in constructing new MWI. Comments are made on papers by Geroch and Deutsch that advocate MWI. It is concluded that no plausible set of axioms exists for an MWI that describes known physics.
QCD CORRECTIONS TO THE WEAK INTERACTIONS OF MESONS IN THE STATIC CAVITY
Authors: HOLLENBERG LLOYD C.L. , MCKELLAR BRUCE H.J.
Published: November 2004

The effect of QCD loop corrections to the weak interactions of hadrons is studied in a nonperturbative framework in which the matrix elements of the bare effective weak Hamiltonian between hadronic states are computed. The QCD renormalization is carried out in the static cavity, alleviating the scale matching problem of the standard short distance analysis. Specifically, we study the Δl=1/2 rule by computing the QCD corrected K-π matrix elements. The modified static cavity model used is characterized by four parameters; the effective quark-gluon coupling constant, the confinement pressure, the zero-point energy and a parameter governing the center-of-mass corrections. These parameters are fitted to the π and ρ masses and the charge radii of π and K. Results are given for the ultrarelativistic (mu=md=0) sector and for a region (mu=md≈140 MeV) where the ΔI=1/2 rule is uniquely reproduced.
QUANTUM SOLITON IN QED IN S1 × R2 SPACETIME
Authors: HIGUCHI ATSUSHI , PARKER LEONARD
Published: November 2004

We consider QED in S1 × R2 spacetime. We show that there exists a kink-like soliton. This soliton does not exist in the classical theory, but arises through competing quantum and classical effects. We also provide a calculation which supports the use of the effective potential in obtaining the soliton.
BRAID STATISTICS FOR THE SOURCES OF THE NONABELIAN CHERN-SIMONS TERM
Authors: BALACHANDRAN A. P. , BOURDEAU M. , JO S.
Published: November 2004

A Lagrangian consisting of an Abelian Chern-Simons term and N identical point particle sources is known to lead to fractional statistics for the sources. In this paper, we investigate the non-Abelian generalization of this system with special emphasis on source statistics. All solutions for the Yang-Mills potential in the presence of identical or nonidentical sources are found. For two or more sources, they fall in many gauge inequivalent classes whereas in the Abelian problem, there is only one such class. An effective Lagrangian for N sources is found for each of these solutions. The quantum mechanics and statistics of the sources are sensitive to the potential leading to the effective Lagrangian. There is for instance, a class of solutions for identical sources which are not invariant under exchange of sources. For these solutions, the identity of the sources obliges us to consider such a potential and all its exchange transforms at the same time, and to introduce a Hilbert space of states which is the direct sum of the Hilbert spaces associated with each of these potentials. There are also exchange invariant potentials for identical sources. For SU(3) and N = 3, all exchange invariant potentials are shown to lead to statistics defined by S3 representations. The nature of statistics for SU (M) for higher M as also the creation of intrinsic spin by self interaction are briefly considered.