bluuebunny/crossref_metadata_2025 huggingface dataset:
A Stable HeLa Cell Line That Inducibly Expresses Poliovirus 2A
pro
: Effects on Cellular and Viral Gene Expression
Authors: Barco Angel , Feduchi Elena , Carrasco Luis
Published: July 2002

A HeLa cell clone (2A7d) that inducibly expresses the gene for poliovirus protease 2A (2A
pro
) under the control of tetracycline has been obtained. Synthesis of 2A
pro
induces severe morphological changes in 2A7d cells. One day after tetracycline removal, cells round up and a few hours later die. Poliovirus 2A
pro
cleaves both forms of initiation factor eIF4G, causing extensive inhibition of capped-mRNA translation a few hours after protease induction. Methoxysuccinyl-Ala-Ala-Pro-Val-chloromethylketone, a selective inhibitor of 2A
pro
, prevents both eIF4G cleavage and inhibition of translation but not cellular death. Expression of 2A
pro
still allows both the replication of poliovirus and the translation of mRNAs containing a picornavirus leader sequence, while vaccinia virus replication is drastically inhibited. Translation of transfected capped mRNA is blocked in 2A7d-On cells, while luciferase synthesis from a mRNA bearing a picornavirus internal ribosome entry site (IRES) sequence is enhanced by the presence of 2A
pro
. Moreover, synthesis of 2A
pro
in 2A7d cells complements the translational defect of a poliovirus 2A
pro
-defective variant. These results show that poliovirus 2A
pro
expression mimics some phenotypical characteristics of poliovirus-infected cells, such as cell rounding, inhibition of protein synthesis and enhancement of IRES-driven translation. This cell line constitutes a useful tool to further analyze 2A
pro
functions, to complement poliovirus 2A
pro
mutants, and to test antiviral compounds.
Frameshift Signal Transplantation and the Unambiguous Analysis of Mutations in the Yeast Retrotransposon Ty1 Gag-Pol Overlap Region
Authors: Lawler Joseph F. , Merkulov Gennady V. , Boeke Jef D.
Published: July 2002

The yeast retrotransposon Ty1 encodes a 7-nucleotide RNA sequence that directs a programmed, +1 ribosomal frameshifting event required for Gag-Pol translation and retrotransposition. We report mutations that block frameshifting, which can be suppressed in
cis
by “transplanting” the frameshift signal to a position upstream of its native location. These “frameshift transplant” mutants transpose with only a modest decrease in efficiency, suggesting that the location of the frameshift signal in a functional Ty1 element may vary. The genomic architecture of Ty1 is such that Gag, Ty1 PR (PR), and the Gag-derived p4 peptide share a common sequence. The functional independence of the movement of the frameshift signal to a new location within the Ty1 element is used to unambiguously attribute the effect of mutations deleterious to transposition in this region of overlapping coding sequences to effects on the Ty1 (PR). This work defines the amino terminus of the Ty1 PR and introduces a new technique for studying viral genome organization.
Identification of Shared Populations of Human Immunodeficiency Virus Type 1 Infecting Microglia and Tissue Macrophages outside the Central Nervous System
Authors: Wang T. H. , Donaldson Y. K. , Brettle R. P. , Bell J. E. , Simmonds P.
Published: July 2002

Infection of microglia and other cells of the macrophage/monocyte lineage in the central nervous system (CNS) by human immunodeficiency virus type I (HIV-1) underlies the development of giant cell encephalitis (GCE). It is currently unknown whether GCE depends on the emergence of virus populations specifically adapted to replicate in cells of the monocyte/macrophage lineage and whether this also leads to the specific targeting of macrophages in other nonlymphoid tissues. Autopsy samples from lymph node, brain (frontal region), lung, and full-thickness colon sections were obtained from nine study subjects with GCE and from nine without. The two groups showed no significant differences in CD4 counts, disease progression, or treatment history before death. Genetic relatedness between variants recovered from lymph node and nonlymphoid tissues was assessed by sequence comparison of V3 and p17gagregions using a newly developed method that scores the sample composition at successive nodes in a neighbor-joining tree. The association index enabled objective, numerical comparisons on the degree of tissue compartmentalization to be made. High proviral loads and p24 antigen expression in the brain were confined to the nine individuals with GCE. GCE was also associated with significantly higher proviral loads in colon samples (median of the GCE+group: 1,010 copies/106cells; median of GCE−group, 10/106cells;P= 0.006). In contrast, there were no significant differences in proviral load between the GCE+and GCE−groups in lymph node or lung samples, where HIV infection was manifested predominantly by infiltrates of lymphoid cells. V3 sequences from brain samples of individuals with GCE showed the greatest compartmentalization from those of lymph node, although samples from other tissues, particularly the colon, frequently contained variants phylogenetically related to those found in brain. The existence of shared, distinct populations of HIV specifically distributed in cells of the monocyte/macrophage lineage was further indicated by immunocytochemical detection of CD68+, multinucleated giant cells expressing p24 antigen in samples of lung and colon in two individuals with GCE. This study provides the basis for future investigation of possible phenotypic similarities that underline the shared distributions of HIV variants infecting microglia and tissue macrophages outside the CNS.
Construction and Manipulation of an Infectious Clone of the Bovine Herpesvirus 1 Genome Maintained as a Bacterial Artificial Chromosome
Authors: Mahony Timothy J. , McCarthy Fiona M. , Gravel Jennifer L. , West Lani , Young Peter L.
Published: July 2002

The complete genome of bovine herpesvirus 1 (BoHV-1) strain V155 has been cloned as a bacterial artificial chromosome (BAC). Following electroporation into
Escherichia coli
strain DH10B, the BoHV-1 BAC was stably propagated over multiple generations of its host. BAC DNA recovered from DH10B cells and transfected into bovine cells produced a cytopathic effect which was indistinguishable from that of the parent virus. Analysis of the replication kinetics of the viral progeny indicated that insertion of the BAC vector into the thymidine kinase gene did not affect viral replication. Specific manipulation of the BAC was demonstrated by deleting the gene encoding glycoprotein E by homologous recombination in DH10B cells facilitated by GET recombination. These studies illustrate that the propagation and manipulation of herpesviruses in bacterial systems will allow for rapid and accurate characterization of BoHV-1 genes. In turn, this will allow for the full utilization of BoHV-1 as a vaccine vector.
Role of Recycling Endosomes and Lysosomes in Dynein-Dependent Entry of Canine Parvovirus
Authors: Suikkanen Sanna , Sääjärvi Katja , Hirsimäki Jonna , Välilehto Outi , Reunanen Hilkka , Vihinen-Ranta Maija , Vuento Matti
Published: July 2002

Canine parvovirus (CPV) is a nonenveloped virus with a 5-kb single-stranded DNA genome. Lysosomotropic agents and low temperature are known to prevent CPV infection, indicating that the virus enters its host cells by endocytosis and requires an acidic intracellular compartment for penetration into the cytoplasm. After escape from the endocytotic vesicles, CPV is transported to the nucleus for replication. In the present study the intracellular entry pathway of the canine parvovirus in NLFK (Nordisk Laboratory feline kidney) cells was studied. After clustering in clathrin-coated pits and being taken up in coated vesicles, CPV colocalized with coendocytosed transferrin in endosomes resembling recycling endosomes. Later, CPV was found to enter, via late endosomes, a perinuclear vesicular compartment, where it colocalized with lysosomal markers. There was no indication of CPV entry into the trans-Golgi or the endoplasmic reticulum. Similar results were obtained both with full and with empty capsids. The data thus suggest that CPV or its DNA was released from the lysosomal compartment to the cytoplasm to be then transported to the nucleus. Electron microscopy analysis revealed endosomal vesicles containing CPV to be associated with microtubules. In the presence of nocodazole, a microtubule-disrupting drug, CPV entry was blocked and the virus was found in peripheral vesicles. Thus, some step(s) of the entry process were dependent on microtubules. Microinjection of antibodies to dynein caused CPV to remain in pericellular vesicles. This suggests an important role for the motor protein dynein in transporting vesicles containing CPV along the microtubule network.
Effect of Addition of KX Type Electrolytes and Temperature on the Critical Micellar Concentrations of 1-Cetylpyridinium and Carbethopendecinium Bromides
Authors: Vojteková Mária , Kopecký František , Greksáková Olga , Oremusová Jarmila
Published: July 2002

The critical micellar concentrations (cmc) of the title cationic surfactants were measured in aqueous solutions at 25 °C in the presence of KBr, KF, KCl, KI, KSCN, KNO3, KAc and HCOOK. The conductometric and, in part, potentiometric methods employing ion selective electrodes were used. For 1-cetylpyridinium bromide in the absence of any of the electrolytes, the decreasing temperature dependence of cmc was measured conductometrically over the region of 12 - 40 °C and the association degree of the micelles with Br- anions was calculated. The decrease in cmc of the two surfactants due to the presence of electrolytes (in concentrations up to tenfold cmc) was expressed by means of a semiempirical equation. There are indications that I- and SCN- anions enter into specific interactions with micelles.
Porous Structure and Transport Properties of a Carbonized Phenolic Resin
Authors: Fott Pavel , Kolář František , Weishauptová Zuzana
Published: July 2002

On carbonizing phenolic resins, the development of porous structure takes place which influences the transport properties of carbonized materials. To give a true picture of this effect, specimens in the shape of plates were prepared and carbonized at various temperatures. The carbonizates obtained were studied by adsorption methods, electron microscopy, and mercury porosimetry. Diffusivities were evaluated in terms of measuring the kinetics of wetting and drying. It was found out that the porous structure of specimens in different stages of carbonization is formed mostly by micropores whose volumes were within 0.06 to 0.22 cm3/g. The maximum micropore volume is reached at the temperature of 750 °C. The dependence of diffusivity on the carbonization temperature is nearly constant at first, begins to increase in the vicinity of 400 °C, and at 600 °C attains its maximum. The experimental results reached are in agreement with the conception of the development and gradual closing of the microporous structure in the course of carbonization. The dependence of diffusivity on temperature can be expressed by the Arrhenius equation. In this connection, two possible models of mass transport were discussed.
Synthesis of Some Derivatives of 8-Aminomethyl- and 8-Azolylmethyl-2-phenyl-3H-quinazoline-4-thiones
Authors: Stankovský Štefan , Špirková Katarína
Published: July 2002

Alkylation of cyclic amines and imides by 8-chloromethyl-2-phenyl-3H-quinazoline-4-thione, prepared by intramolecular cyclization of N-(2-chloromethylphenyl)benzimidoyl isothiocyanate, afforded ten N,N-disubstituted 8-aminomethyl-2-phenyl-3H-quinazoline-4-thiones.
Epimerization During Coupling to the Unnatural Amino Acid in Solid Phase Peptide Synthesis
Authors: Zhang Zhenyu , Van Aerschot Arthur , Chaltin Patrick , Busson Roger , Herdewijn Piet
Published: July 2002

Extensive epimerization was observed during the coupling of Fmoc-L-Trp(Boc) and Fmoc-L-Pro to D-Ual, a synthetic α-amino acid with a nucleobase in the side chain. This unnatural amino acid was used extensively in the construction of nucleic acids recognition libraries. Reaction protocols based on the use of DIC-HOAt-DIEA mixture without preactivation of the coupling mixture has been proven to suppress the epimerization reaction significantly.
Occupational asthma caused by bacillary amylase used in the detergent industry
Authors: Hole A M , Draper A , Jolliffe G , Cullinan P , Jones M , Taylor A J Newman
Published: July 2002

Four cases are reported of occupational asthma due to amylase derived fromBacillus licheniformis, used in detergent washing powders. It is thought that these are the first reported cases of asthma due to this enzyme in the detergent industry. All four employees (men) were from the same factory and none had a history of asthma or atopy. All developed symptoms of wheeze at work after an initial symptom free period. Symptoms improved during periods away from work. All undertook serial peak flow recordings (not diagnostic) and underwent skin prick tests, radio allergosorbent test (RAST) measurement, and specific bronchial provocation testing. The bronchial provocation testing was performed by a dust tipping method in a single blind manner, with lactose as an inert control and powdered amylase, provided by the employer, as an active agent. Serial measurements of forced expiratory volume in 1 second (FEV1) were recorded and histamine provocative concentration causing a 20% fall in FEV1(PC20) tests were determined before and 24 hours after each challenge. Patient 1 developed an isolated early reaction, patient 2 an isolated late reaction, and patients 3 and 4 developed dual reactions. All showed an increased non-specific bronchial responsiveness after active challenge. The introduction of encapsulated enzymes in the detergent industry was followed by a reduction in the incidence of respiratory sensitisation. These patients developed occupational asthma despite working only with encapsulated enzymes. This highlights the importance of careful surveillance after the introduction of new agents in the workplace.
Occupational exposure to solvents and male infertility
Authors: Cherry N , Labrèche F , Collins J , Tulandi T
Published: July 2002

OBJECTIVES

To determine whether, in a case-referent study of infertility patients, cases with low motile sperm count were more likely than referents to have had exposure to organic solvents.

METHODS

Occupations of men attending fertility clinics in Canada were assigned codes reflecting probable exposure to organic solvents, at four grades of intensity, using a job exposure matrix previously developed. A case referent design was used, with cases being defined as men with <12×106/ml motile sperm. Information from 656 men in manual work attending a single clinic in Montreal in 1972–91 was used for the main study. A separate analysis was conducted with information for 574 men in manual work attending 10 further clinics across Canada in 1984–7.

RESULTS

In the Montreal series a significant association was found between intensity of exposure to solvents and clinical findings of <12×106/ml motile sperm. Odds ratios (ORs), after allowing for confounding, were 2.07 (95% confidence interval (95% CI) 1.24 to 3.44) for moderate exposure to solvents and 3.83 (95% CI 1.37 to 10.65) for high exposure. In the second series of 568 men, the effect was confirmed at high exposure to solvents (OR 2.90, 95% CI 1.01 to 8.34) but not at moderate exposure (OR 1.01, 95% CI 0.53 to 1.92).

CONCLUSIONS

Exposure to organic solvents is common both at work and in recreational pursuits. The results of this study suggest that efforts should be made to identify the compounds hazardous to male fertility, and if the risk is confirmed, to regulate their use.
Lymphoma in an ileostomy
Authors: Pranesh N
Published: July 2002

Lymphoma developing in an ileostomy is an extremely rare complication. The presentation is similar to the commoner, yet still rare, adenocarcinoma but the staging and management of the condition differs.
SPECTRAL CONCENTRATION AND RESONANCES FOR UNITARY OPERATORS: APPLICATIONS TO SELF-ADJOINT PROBLEMS
Authors: WATANABE KAZUO
Published: July 2002

We shall treat the spectral concentration for unitary operators operator-theoretically and apply to the problem of the resonance of self-adjoint operator family. We shall calculate the decay rate of the resonance state of two concrete models.
AN ALGEBRAIC APPROACH TO THE KOLMOGOROV-SINAI ENTROPY
Authors: ALICKI R. , ANDRIES J. , FANNES M. , TUYLS P.
Published: July 2002

We revisit the notion of Kolmogorov-Sinai entropy for classical dynamical systems in terms of an algebraic formalism. This is the starting point for defining the entropy for general non-commutative systems. Hereby typical quantum tools are introduced in the statistical description of classical dynamical systems. We illustrate the power of these techniques by providing a simple, self-contained proof of the entropy formula for general automorphisms of n-dimensional tori.
Quasivectors and Tomita–Takesaki Theory for Operator Algebras on Π1-Spaces
Authors: Shulman Victor S.
Published: July 2002

We consider operator algebras, which are symmetric with respect to an indefinite scalar product. It is shown, that in the case when the rank of indefiniteness is equal to 1 there exists a working modular theory, and in particular a precise analogue of the Fundamental Tomita's Theorem holds:

For any weakly closed J-symmetric operator algebra [Formula: see text] with identity on a Π1-space H which has a cyclic and separating vector, there is an antilinear J-involution j : H→H such that [Formula: see text].

The paper also contains a full proof of the Double Commutant Theorem for J-symmetric operator algebras on Π1-spaces.
CHARACTERS OF STRONGLY GENERIC IRREDUCIBLE LIE SUPERALGEBRA REPRESENTATIONS
Authors: PENKOV IVAN
Published: July 2002

An explicit character formula is established for any strongly generic finite-dimensional irreducible [Formula: see text]-module, [Formula: see text] being an arbitrary finite-dimensional complex Lie superalgebra. This character formula had been conjectured earlier by Vera Serganova and the author for any generic irreducible finite-dimensional [Formula: see text]-module, i.e. such that its highest weight is far enough from the walls of the Weyl chambers. The condition of strong genericity, under which the conjecture is proved in this paper, is slightly stronger than genericity, but if in particular no simple component of [Formula: see text] is isomorphic to psq(n) for n ≥ 3 or to H(2k + 1) for k ≥ 2, strong genericity is equivalent to genericity.
WHAT IS QUANTUM COMPUTATION?
Authors: EKERT ARTUR , HAYDEN PATRICK , INAMORI HITOSHI , OI DANIEL KUAN LI
Published: July 2002

"Information is physical and any processing of information is always performed by physical means," an innocent-sounding statement, but its consequences are profound. When quantum effects become important, for example, at the level of single atoms and photons, the classical theory of computation becomes fundamentally inadequate. Entirely new modes of computation and information processing become possible. In the last few years there has been an explosion of theoretical and experimental research in quantum computation. In this brief review we describe some of these developments.
AdS/CFT DUALITY AND THE GLUEBALL SPECTRUM
Authors: BROWER RICHARD C.
Published: July 2002

The complete glueball spectrum for the AdS7 black hole supergravity dual of QCD is shown to bare a striking resemblance to the known lattice results despite the limitations of the strong coupling approximation. Further extensions of duality to couple hadronic matter to gravity in the Randall-Sundram brane world scenario are suggested.
LOW DIRAC EIGENMODES AND THE TOPOLOGICAL AND CHIRAL STRUCTURE OF THE QCD VACUUM
Authors: THACKER H. B.
Published: July 2002

Several lattice calculations which probe the chiral and topological structure of QCD are discussed. The results focus attention on the low-lying eigenmodes of the Dirac operator in typical gauge field configurations.
SSB OF SCALE SYMMETRY, FERMION FAMILIES AND QUINTESSENCE WITHOUT THE LONG-RANGE FORCE PROBLEM
Authors: GUENDELMAN E. I. , KAGANOVICH A. B.
Published: July 2002

We study a scale-invariant two measures theory where a dilaton field ϕ has no explicit potentials. The scale transformations include the translation of a dilaton ϕ→ϕ+ const . The theory demonstrates a new mechanism for generation of the exponential potential: in the conformal Einstein frame (CEF), after SSB of scale invariance, the theory develops the exponential potential and, in general, the nonlinear kinetic term is generated as well. The scale symmetry does not allow the appearance of terms breaking the exponential shape of the potential that solves the problem of the flatness of the scalar field potential in the context of quintessential scenarios. As examples, two different possibilities for the choice of the dimensionless parameters are presented where the theory permits to get interesting cosmological results. For the first choice, the theory has standard scaling solutions for ϕ usually used in the context of the quintessential scenario. For the second choice, the theory allows three different solutions, one of which is a scaling solution with equation of state pϕ=wρϕ where w is predicted to be restricted by -1<w<-0.82. The regime where the fermionic matter dominates (as compared to the dilatonic contribution) is analyzed. There it is found that starting from a single fermionic field we obtain exactly three different types of spin 1/2 particles in CEF that appears to suggest a new approach to the family problem of particle physics. It is automatically achieved that for two of them, fermion masses are constants, the energy–momentum tensor is canonical and the "fifth force" is absent. For the third type of particles, a fermionic self-interaction appears as a result of SSB of scale invariance.
THE AFFINE $A_{n-1}^{(1)}$ TODA FIELDS WITH BOUNDARY REFLECTION
Authors: KOJIMA TAKEO
Published: July 2002

We study the affine [Formula: see text] Toda fields with boundary reflection. Our approach is based on the free field approach. We construct free field realizations of the boundary state and its dual. For an application of these realizations, we present integral representations for the form factors of the local operators. In a limiting case ρ→ ∞, our integral representations reproduce those of form factors for the SU (n)-invariant massive Thirring model with boundary reflection.1
TOPOLOGICAL LATTICE MODEL OF ELECTRONS COUPLED TO A CLASSICAL POLARIZATION FIELD
Authors: Schwalm W. , Crockett S. , Moritz B.
Published: July 2002

A simple model for an electron in two dimensions interacting with an elastic distortion field shows interesting polaron-like behaviors. The model consists of a single tight-binding electron in a classical polarization field. The distortion potential ϕ and electron amplitude ψ evolve by coupled dynamical equations derived from a Lagrangian with cross term gϕ|ψ|2. The equations of motion for ψ and ϕ are integrated together in time. For large enough g, the electron self-traps and a bound polaron-like object exists with time independent ϕ in the shape of a well and ψ a stationary state in the well. There is a critical value gmin below which the polaron well disappears. Spectral densities obtained by transforming double-time Green functions into [Formula: see text] show mass enhancement and lifetime broadening effects. The model, such as it is, can be extended easily to arbitrary, confined geometries in two or three dimensions.
SPHERULITIC GROWTH IN PROTEIN SOLUTIONS
Authors: CHOW PUI SHAN , ZHANG JING , LIU XIANG YANG , TAN REGINALD BENG HEE
Published: July 2002

Lysozyme was chosen as a model system for investigation of spherulitic growth in protein solution. Solutions of various concentrations of lysozyme and sodium chloride were studied under an optical microscope using polarized light. Spherulites were observed in the liquid-liquid separation regime. Images at various stages during the crystal growth process are presented. In a separate set of experiments, it was demonstrated that the presence of foreign particles could promote spherulitic growth even without liquid-liquid separation.
OPTICAL PROPERTIES OF TRIMETHYLBORON AND NITROGEN CODOPED AMORPHOUS CARBON FILMS
Authors: HAYASHI Y. , ISHIKAWA S. , SOGA T. , JIMBO T. , ADACHI M. , UMENO M.
Published: July 2002

We report on the efficient photoluminescence (PL) and optical properties of hydrogenated amorphous carbon thin films codoped with nitrogen and trimethylboron (TMB) grown by rf plasma-enhanced chemical vapor deposition at room temperature. The study clearly shows the observation of discrete PL emission peaks. The PL intensity of the film deposited with 20 sccm TMB is more than 103 times than that of the film deposited without TMB. The change of optical bandgap and PL emission energy with TMB flow rate are discussed based on sp3 and sp2 C networks. Angular dependence of the PL spectra revealed that the origin of multiple sharp peaks is due to Fabry-Perot cavity interference effect.
MAGNETIC SUSCEPTIBILITY OF LIQUID METALS
Authors: KHAJIL T. M. A.
Published: July 2002

The magnetic susceptibility of a liquid metals is calculated using the first principle Bachelet–Hamann–Schlüter (BHS) model potential and Timbie–White approach. The simple model potential has been used also in this calculations. The results obtained by the using of (BHS) potential are in good agreement with the experiment.
ON THE STICKING MECHANISM IN PRESENCE OF INELASTIC SCATTERING AND SELECTIVE ADSORPTION RESONANCES
Authors: DUTTAMUDI G. , ROY S. K.
Published: July 2002

The sticking coefficients of He 4 on graphite and solid argon surfaces are calculated in presence of bound state resonances. It is observed that the over-counting of the scattering events which make the sticking coefficients greater than unity in these systems under usual distorted wave Born approximation (DWBA), can be removed by considering the exact T-matrix in presence of bound state resonances. This also gives rise to interesting results on temperature variation of sticking coefficients.
A+B→0 AND A+A→0 CHEMICAL REACTIONS UNDER ENHANCED DIFFUSION CONDITIONS THROUGH THOMPSON'S METHOD
Authors: NASSIF CLÁUDIO , SILVA P. R.
Published: July 2002

In this work we use Thompson's method to study both A+B→0 and A+A→0 reactions under anomalous diffusion regimes. We consider a general action encompassing the two kinds of reactions, by including a non-brownian (γ<2) superdiffusion mechanism, for instance, Levy-mixing. Such a kind of mechanism leads to a continuous mixing of the reactants, which homogenizes the system, thereby partially suppressing the fluctuations. We show that for [Formula: see text], the segregation disappears in d=3 in the A+B→0 reaction in agreement with previous results of Zumofen, Klafter and Shlesinger. This last result can be interpreted as the erosion of the segregation in d=3. In the A+A→0 reaction, the superdiffusion mechanism leads to the decreasing of the upper critical dimension (d c ). We also show that, at d c , we always obtain logarithmic corrections both for the reactant concentrate decays (<∊>) and for the reaction rates ().
VIEW SYNTHESIS UNDER PERSPECTIVE PROJECTION
Authors: FENG G. C. , LAI J. H. , YUEN P. C.
Published: July 2002

This paper addresses the issue of generating a 2D view of a 3D object from its other 2D views. Linear Combination method is the typical approach to this problem. However, a 2D view cannot be represented by a linear combination of other 2D views under perspective projection. Instead, we have presented a solution under perspective projection. The proposed method also applies to the construction of virtual frontal view face image and the results are encouraging.
USING CONTROL OF CHAOS TO REFINE APPROXIMATIONS TO PERIODIC POINTS
Authors: ASTON P. J. , BIRD C. M.
Published: July 2002

The OGY method for controlling chaos using parameter perturbations is analyzed assuming that the regression approximation to the fixed point is not exact. This leads to a method for obtaining a new approximation to the fixed point which can be applied iteratively and which gives a fixed point of high accuracy. The method is extended to systems with noise and so is appropriate for use in experimental systems.
DELIBERATIVE EVOLUTION IN MULTI-AGENT SYSTEMS
Authors: BRAZIER F. M. T. , JONKER C. M. , TREUR J. , WIJNGAARDS N. J. E.
Published: July 2002

Evolution of automated systems, in particular evolution of automated agents based on agent deliberation, is the topic of this paper. Evolution is not a merely material process, it requires interaction within and between individuals, their environments and societies of agents. An architecture for an individual agent capable of (1) deliberation about the creation of new agents, and (2) (run-time) creation of a new agent on the basis of this, is presented. The agent architecture is based on an existing generic agent model, and includes explicit formal conceptual representations of both design structures of agents and (behavioural) properties of agents. The process of deliberation is based on an existing generic reasoning model of design. The architecture has been designed using the compositional development method DESIRE, and has been tested in a prototype implementation.
MEMBRANOUS TISSUE UNDER THE FLEXOR CARPI ULNARIS MUSCLE AS A CAUSE OF CUBITAL TUNNEL SYNDROME
Authors: Matsuzaki Akio
Published: July 2002

Membranous tissue under the flexor carpi ulnaris (FCU), hypertrophy and fascia of the FCU were examined in 90 patients with cubital tunnel syndrome; it (submuscular membrane) was found in all patients, excluding five whose data were incomplete. Impressions on the nerve under the FCU were noted in 75 patients. In 43 patients, the submuscular membrane was judged to be the cause of neural compression. These 75 patients included 60 and 15 cases whose fascia of the FCU were judged to the thick and thin, respectively. Among the 58 with a thick submuscular membrane, 56 patients had an impression under the membrane. Fifteen patients had a flat impression on the nerve in the proximal compartment of the FCU, which was formed by ligamentous and bony floor and thick fascia of the FCU. It is believed that increased presure in the compartment is the cause of a flat impression. Slight compression of the nerve under the FCU with compressions in proximal and distal part of the nerve can cause symptoms of the nerve compression by multiple crush effect.
Congenital Unilateral Synostosis of Elbow Associated with Multiple Hand Anomalies (Case Report)
Authors: Togrul Emre , Sarpel Yaman , Bayram Huseyin
Published: July 2002

Congenital synostosis of the elbow is a very rare malformation of the upper limb. We present two similar cases with congenital humeroradial synostosis in association with absence of the ulnar carpals, fourth and fifth metacarpals and phalanges, and syndactily between the second and third fingers. Both cases were male and their anomalies were on the right side. In the second case, an Aitken type-2 proximal focal deficiency of femur was also present.
LEARNING, COMPETITION AND COOPERATION IN SIMPLE GAMES
Authors: DE CARA M. ÁNGELES R. , PLA ÓSCAR , GUINEA FRANCISCO
Published: July 2002

The Minority Game was introduced to study the competition between agents with bounded rationality. As the amount of information available decreases, agents manage to arbitrage away all the information, and collective gain is then reduced. This crowd effect arises from the fact that only a minority can profit at each moment, while all agents make their choices using the same input. The properties of the model change drastically if agents make choices based on their individual histories, keeping all remaining rules unaltered. This variation reduces the intrinsic frustration of the model, and improves the tendency towards cooperation and self organization. Finally, we study the stable mixing of individual and cooperative behavior.
The Year-End Anomaly of Taiwanese Family-Controlled Groupings
Authors: Yeh Yin-Hua , Shu Pei-Gi , Huang Wen-Yi
Published: July 2002

The average abnormal return of Taiwanese family-controlled grouping (1.60 percent) is significantly higher than that of individually listed companies (0.03 percent) in December. Within the same family-controlled grouping, the average abnormal return in December is also higher than that of the rest of the months (-0.13 percent) in the sampling periods 1992 through 1997. We cautiously set five joint criteria to define the anomaly in December that pertains only to the family-controlled grouping. The empirical results supported our argument by which the ornamenting motive of the family-controlled grouping is to account for the anomaly. For illustration, we further identify company size, losses from currency translation and bad debt, cash flow, and the gain from selling long-term investment which can effectively contrast the willingness and capability of family-controlled grouping to engage in the year-end earning management.
PERIODIC VORTEX LATTICES FOR THE LAWRENCE–DONIACH MODEL OF LAYERED SUPERCONDUCTORS IN A PARALLEL FIELD
Authors: ALAMA S. , BRONSARD L. , BERLINSKY A. J.
Published: July 2002

We consider the Lawrence–Doniach model for layered superconductors, in which stacks of parallel superconducting planes are coupled via the Josephson effect. We assume that the superconductor is placed in an external magnetic field oriented parallel to the superconducting planes and study periodic lattice configurations in the limit as the Josephson coupling parameter r→0. This limit leads to the "transparent state" discussed in the physics literature, which is observed in very anisotropic high-Tc superconductors at sufficiently high applied fields and below a critical temperature. We use a Lyapunov–Schmidt reduction to prove that energy minimization uniquely determines the geometry of the optimal vortex lattice: a period-2 (in the layers) array proposed by Bulaevskiĭ & Clem. Finally, we discuss the apparent conflict with previous results for finite-width samples, in which the minimizer in the small coupling regime takes the form of "vortex planes" (introduced by Theodorakis and Kuplevakhsky).
CLASSIFYING DESIGN AND DESIGN MANAGEMENT IN SEASONAL INDUSTRIES
Authors: ECKERT CLAUDIA , DEMAID ADRIAN
Published: July 2002

This paper classifies design processes in seasonal industries, where designs of consumer products have to be delivered to tight deadlines, from the viewpoint of the relationship between the design company, the retailer and the final customers. The paper looks specifically at the risk that designers and retailers carry, the design rework required by the retailer and the communication between the retailer and the designer. We employ a motoring metaphor to show six models of design.
The pagenumber of genus
g
graphs is O(
g
)
Authors: Heath Lenwood S. , Istrail Sorin
Published: July 2002

In 1979, Bernhart and Kainen conjectured that graphs of fixed genus
g
≥ 1 have unbounded pagenumber. In this paper, it is proven that genus
g
graphs can be embedded in
O
(
g
) pages, thus disproving the conjecture. An Ω(
g
1/2
) lower bound is also derived. The first algorithm in the literature for embedding an arbitrary graph in a book with a non-trivial upper bound on the number of pages is presented. First, the algorithm computes the genus
g
of a graph using the algorithm of Filotti, Miller, Reif (1979), which is polynomial-time for fixed genus. Second, it applies an optimal-time algorithm for obtaining an
O
(
g
)-page book embedding. Separate book embedding algorithms are given for the cases of graphs embedded in orientable and nonorientable surfaces. An important aspect of the construction is a new decomposition theorem, of independent interest, for a graph embedded on a surface. Book embedding has application in several areas, two of which are directly related to the results obtained: fault-tolerant VLSI and complexity theory.
Evaluating models of memory allocation
Authors: Zorn Benjamin , Grunwald Dirk
Published: July 2002

Because dynamic memory management is an important part of a large class of computer programs, high-performance algorithms for dynamic memory management have been and will continue to be of considerable interest. The goal of this research is to explore the size and accuracy of synthetic models of program allocation behavior. These models, if accurate enough, proved an attractive alternative to algorithm evaluation based on trace-driven simulation using actual traces. Based on our analysis, we conclude that even relatively simple synthetic models can effectively emulate the allocation behavior of well-behaved programs. However, even the most complex models we investigate can only roughly approximate the behavior of more complex programs and/or allocation policies. While synthetic models have been used to evaluate the performance of dynamic memory management algorithms, our results show that these models can be inaccurate and must be used with care. Given current trends toward more complex applications and allocation algorithms, the synthetic models we investigate are likely to be even less accurate in the future.
Mixed integer programming methods for computing nonmonotonic deductive databases
Authors: Bell Colin , Nerode Anil , Ng Raymond T. , Subrahmanian V. S.
Published: July 2002

Though the declarative semantics of both explicit and nonmonotonic negation in logic programs has been studied extensively, relatively little work has been done on computation and implementation of these semantics. In this paper, we study three different approaches to computing stable models of logic programs based on mixed integer linear programming methods for automated deduction introduced by R. Jeroslow. We subsequently discuss the relative efficiency of these algorithms. The results of experiments with a prototype compiler implemented by us tend to confirm our theoretical discussion. In contrast to resolution, the mixed integer programming methodology is both fully declarative and handles reuse of old computations gracefully.

We also introduce, compare, implement, and experiment with linear constraints corresponding to four semantics for “explicit” negation in logic programs: the four-valued annotated semantics [Blair and Subrahmanian 1989], the Gelfond-Lifschitz semantics [1990], the over-determined models [Grant and Subrahmanian 1989], the Gelfond-Lifschitz semantics [1990], the over-determined models [Grant and Subrahmanian 1990], and the classical logic semantics. Gelfond and Lifschitz[1990] argue for simultaneous use of two modes of negation in logic programs, “classical” and “nonmonotonic,” so we give algorithms for computing “answer sets” for such logic programs too.
A survey of Boolean matching techniques for library binding
Authors: Benini Luca , De Micheli Giovanni
Published: July 2002

When binding a logic network to a set of cells, a fundamental problem is recognizing whether a cell can implement a portion of the network. Boolean matching means solving this task using a formalism based on Boolean algebra. In its simplest form, Boolean matching can be posed as a tautology check. We review several approaches to Boolean matching as well as to its generalization to cases involving
don't care
conditions and its restriction to specific libraries such as those typical of anti-fuse based FPGAs. We then present a general formulation of Boolean matching supporting multiple-output logic cells.
Fast and accurate hierarchical radiosity using global visibility
Authors: Durand Frédo , Drettakis George , Puech Claude
Published: July 2002

Recent hierarchical global illumination algorithms permit the
generation of images with a high degree of realism. Nonetheless, appropriate refinement of light transfers, high quality meshing, and accurate visibility calculation can be challenging tasks. This is particularly true for scenes containing multiple light sources and scenes lit mainly by indirect light. We present solutions to these problems by extending a global visibility data structure, the Visibility Skeleton. This extension allows us to calculate exact point-to-polygon form-factors at vertices created by subdivision. The structures also provides visibility information for all light interactions, allowing intelligent refinement strategies. High-quality meshing is effected based on a perceptualy based ranking strategy which results in appropriate insertions of discontinuity curves into the meshes representing illumination. We introduce a hierarchy of triangulations that allows the generation of a hierarchical radiosity solution using accurate visibility and meshing. Results of our implementation show that our new algorithm produces high quality view-independent lighting solutions for direct illumination, for scenes with multiple lights and also scenes lit mainly by indirect illumination.
Security of statistical databases
Authors: Schlöer Jan
Published: July 2002

Statistical evaluation of databases which contain personal records may entail risks for the confidentiality of the individual records. The risk has increased with the availability of flexible interactive evaluation programs which permit the use of trackers, the most dangerous class of snooping tools known. A class of trackers, called union trackers, is described. They permit reconstruction of the entire database without supplementary knowledge and include the general tracker recently described as a special case. For many real statistical databases the overwhelming majority of definable sets of records will form trackers. For such databases a random search for a tracker is likely to succeed rapidly. Individual trackers are redefined and counted and their cardinalities are investigated. If there are
n
records in the database, then most individual trackers employ innocent cardinalities near
n
/3, making them difficult to detect. Disclosure with trackers usually requires little effort per retrieved data element.
Necessary and Sufficient Conditions for Dynamic Programming of Combinatorial Type
Authors: Bonzon P.
Published: July 2002

A general formulation of discrete deterministic dynamic programming is given. This definition is obtained formally by derivation of a simplified algorithm from a general algorithm, and gives simultaneously the class of concurrent problems.
Iterated Limiting Recursion and the Program Minimization Problem
Authors: Schubert L. K.
Published: July 2002

The general problem of finding minimal programs realizing given “program descriptions” is considered, where program descriptions may be of finite or infinite length and may specify arbitrary program properties. The problem of finding minimal programs consistent with finite or infinite input-output lists is a special case (for infinite input-output lists, this is a variant of E. M. Gold's function identification problem). Although most program minimization problems are not recursively solvable, they are found to be no more difficult than the problem of deciding whether any given program realizes any given description, or the problem of enumerating programs in order of nondecreasing length (whichever is harder). This result is formulated in terms of
k
-limiting recursive predicates and functionals, defined by repeated application of Gold's limit operator. A simple consequence is that the program minimization problem is limiting recursively solvable for finite input-output lists and 2-limiting recursively solvable for infinite input-output lists, with weak assumptions about the measure of program size. Gold regarded limiting function identification (more generally, “black box” identification) as a model of inductive thought. Intuitively, iterated limiting identification might be regarded as higher-order inductive inference performed collectively by an ever-growing community of lower order inductive inference machines.
On the capabilities of while, repeat, and exit statements
Authors: Peterson W. W. , Kasami T. , Tokura N.
Published: July 2002

A well-formed program is defined as a program in which loops and if statements are properly nested and can be entered only at their beginning. A corresponding definition is given for a well-formed flowchart. It is shown that a program is well formed if and only if it can be written with if, repeat, and multi-level exit statements for sequence control. It is also shown that if, while, and repeat statements with single-level exit do not suffice. It is also shown that any flowchart can be converted to a well-formed flowchart by node splitting. Practical implications are discussed.
Generating gamma variates by a modified rejection technique
Authors: Ahrens J. H. , Dieter U.
Published: July 2002

A suitable square root transformation of a gamma random variable with mean
a
≥ 1 yields a probability density close to the standard normal density. A modification of the rejection technique then begins by sampling from the normal distribution, being able to accept and transform the initial normal observation quickly at least 85 percent of the time (95 percent if
a
≥ 4). When used with efficient subroutines for sampling from the normal and exponential distributions, the resulting accurate method is significantly faster than competing algorithms.
Syntax-directed least-errors analysis for context-free languages
Authors: Lyon Gordon
Published: July 2002

A least-errors recognizer is developed informally using the well-known recognizer of Earley, along with elements of Bellman's dynamic programming. The analyzer takes a general class of context-free grammars as drivers, and any finite string as input. Recognition consists of a least-errors count for a corrected version of the input relative to the driver grammar. The algorithm design emphasizes practical aspects which help in programming it.
Backtrack programming techniques
Authors: Bitner James R. , Reingold Edward M.
Published: July 2002

The purpose of this paper is twofold. First, a brief exposition of the general backtrack technique and its history is given. Second, it is shown how the use of macros can considerably shorten the computation time in many cases. In particular, this technique has allowed the solution of two previously open combinatorial problems, the computation of new terms in a well-known series, and the substantial reduction in computation time for the solution to another combinatorial problem.
Eigenvectors of a 2n × 2n matrix
Authors: Charmonman S.
Published: July 2002

It has been known that the eigenvalues of a certain 2
n
× 2
n
matrix can be obtained by use of two smaller matrices of order
n
which can be easily constructed. An algorithm is given to obtain the eigenvectors of the 2
n
× 2
n
matrix by use of the eigenvectors of the smaller matrices.
Calculating joint queue-length distributions in product-form queuing networks
Authors: de Souza e Silva Edmundo , Lavenberg S. S.
Published: July 2002

A new computational algorithm called distribution analysis by chain (DAC) is developed. This algorithm computes joint queue-length distributions for product-form queuing networks with single-server fixed rate, infinite server, and queue-dependent service centers. Joint distributions are essential in problems such as the calculation of availability measures using queuing network models. The algorithm is efficient since the cost to evaluate joint queue-length probabilities is of the same order as the number of these probabilities. This contrasts with the cost of evaluating these probabilities using previous algorithms. The DAC algorithm also computes mean queue lengths and throughputs more efficiently than the recently proposed RECAL and MVAC algorithms. Furthermore, the algorithm is numerically stable and its recursion is surprisingly simple.
Opportunities for research on numerical control machining
Authors: Grossman David D.
Published: July 2002

Numerical control (NC) machining could be reinvigorated by adapting robotic software technology. Regrettably, pressures are mounting in industry to constrain robots to NC standards, and the academic community views NC as an obsolete, solved problem, with little remaining scholarly challenge. Grossman examines the current status of APT, an NC language, and proposes the merging of APT with a modern robotics language.