bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of H5N1 Influenza Viruses That Continue To Circulate in Geese in Southeastern China
Authors: Webster Robert G. , Guan Yi , Peiris Malik , Walker David , Krauss Scott , Zhou Nan Nan , Govorkova Elena A. , Ellis Trevor M. , Dyrting K. C. , Sit Thomas , Perez Daniel R. , Shortridge Kennedy F.
Published: July 2002

The H5N1 influenza virus, which killed humans and poultry in 1997, was a reassortant that possibly arose in one type of domestic poultry present in the live-poultry markets of Hong Kong. Given that all the precursors of H5N1/97 are still circulating in poultry in southern China, the reassortment event that generated H5N1 could be repeated. Because A/goose/Guangdong/1/96-like (H5N1; Go/Gd) viruses are the proposed donors of the hemagglutinin gene of the H5N1 virus, we investigated the continued circulation, host range, and transmissibility of Go/Gd-like viruses in poultry. The Go/Gd-like viruses caused weight loss and death in some mice inoculated with high virus doses. Transmission of Go/Gd-like H5N1 viruses to geese by contact with infected geese resulted in infection of all birds but limited signs of overt disease. In contrast, oral inoculation with high doses of Go/Gd-like viruses resulted in the deaths of up to 50% of infected geese. Transmission from infected geese to chickens occurred only by fecal contact, whereas transmission to quail occurred by either aerosol or fecal spread. This difference is probably explained by the higher susceptibility of quail to Go/Gd-like virus. The high degree of susceptibility of quail to Go/Gd (H5N1)-like viruses and the continued circulation of H6N1 and H9N2 viruses in quail support the hypothesis that quail were the host of origin of the H5N1/97 virus. The ease of transmission of Go/Gd (H5N1)-like viruses to land-based birds, especially quail, supports the wisdom of separating aquatic and land-based poultry in the markets in Hong Kong and the need for continued surveillance in the field and live-bird markets in which different types of poultry are in contact with one another.
Molecular and Immunological Significance of Chimpanzee Major Histocompatibility Complex Haplotypes for Hepatitis C Virus Immune Response and Vaccination Studies
Authors: Mizukoshi Eishiro , Nascimbeni Michelina , Blaustein Joshua B. , Mihalik Kathleen , Rice Charles M. , Liang T. Jake , Feinstone Stephen M. , Rehermann Barbara
Published: July 2002

The chimpanzee is a critical animal model for studying cellular immune responses to infectious pathogens such as hepatitis B and C viruses, human immunodeficiency virus, and malaria. Several candidate vaccines and immunotherapies for these infections aim at the induction or enhancement of cellular immune responses against viral epitopes presented by common human major histocompatibility complex (MHC) alleles. To identify and characterize chimpanzee MHC class I molecules that are functionally related to human alleles, we sequenced 18 differentPan troglodytes(Patr) alleles of 14 chimpanzees, 2 of them previously unknown and 3 with only partially reported sequences. Comparative analysis of Patr binding pockets and binding assays with biotinylated peptides demonstrated a molecular homology between the binding grooves of individual Patr alleles and the common human alleles HLA-A1, -A2, -A3, and -B7. Using cytotoxic T cells isolated from the blood of hepatitis C virus (HCV)-infected chimpanzees, we then mapped the Patr restriction of these HCV peptides and demonstrated functional homology between the Patr-HLA orthologues in cytotoxicity and gamma interferon (IFN-γ) release assays. Based on these results, 21 HCV epitopes were selected to characterize the chimpanzees' cellular immune response to HCV. In each case, IFN-γ-producing T cells were detectable in the blood after but not prior to HCV infection and were specifically targeted against those HCV peptides predicted by Patr-HLA homology. This study demonstrates a close functional homology between individual Patr and HLA alleles and shows that HCV infection generates HCV peptides that are recognized by both chimpanzees and humans with Patr and HLA orthologues. These results are relevant for the design and evaluation of vaccines in chimpanzees that can now be selected according to the most frequent human MHC haplotypes.
The Phosphoprotein (P) Binding Site Resides in the N Terminus of the L Polymerase Subunit of Sendai Virus
Authors: Holmes David E. , Moyer Sue A.
Published: July 2002

Sendai virus encodes an RNA-dependent RNA polymerase which is composed of the L and P proteins. Site-directed mutagenesis of the N terminus of L has identified amino acids important for binding P. Seven of nine mutants in amino acids 1 to 350 of Sendai L lost the ability to bind to Sendai P, although they were still able to bind the viral C protein. Loss of P binding correlated with the loss of all RNA synthesis activities. Two L mutants gave limited P-L complex formation and limited viral transcription and replication.
Interaction between Parvovirus NS2 Protein and Nuclear Export Factor Crm1 Is Important for Viral Egress from the Nucleus of Murine Cells
Authors: Miller Cathy L. , Pintel David J.
Published: July 2002

A mutation that disrupts the interaction between the NS2 protein of minute virus of mice and the nuclear export factor Crm1 results in a block to egress of mutant-generated full virions from the nucleus of infected murine cells. These mutants produce wild-type levels of monomer and dimer replicative DNA forms but are impaired in their ability to generate progeny single-stranded DNA in restrictive murine cells in the first round of infection. The NS2-Crm1 interaction mutant can be distinguished phenotypically from an NS2-null mutant and reveals a role for the Crm1-mediated export pathway at a late step in viral infection.
Trace Analysis of Ultrapure Arsenic and Selenium by Graphite Furnace Atomic Absorption Spectrometry
Authors: Korečková Jiřina , Musil Josef
Published: July 2002

A method for the determination of trace and ultratrace impurities like Co, Cu, Cr, Fe and Ni in pure arsenic and selenium by graphite furnace atomic absorption spectrometry has been developed. The sample preparation and the measurement was performed in a clean laboratory with HEPA filtrated air providing a class 100 working environment. For correction on the blank the expected values estimated from a set of blanks were used respecting the distribution (normal or lognormal) tested by Shapiro Wilk test. Detection limits for the whole procedure estimated according to the IUPAC 3 σ definition are somewhat higher for the Se matrix, but still allow the analysis of As and Se samples of 5N5 purity as required.
Preparation of (20E)-21-Ethoxycarbonyl-14β,17α-pregna-5,20-dien-3β-yl Hydrogen Butanedioate
Authors: Pouzar Vladimír , Černý Ivan
Published: July 2002

The title compound X was prepared according to the recently published procedure for preparation of analogous derivatives in the 5β-pregnane series, using the reaction sequence I -> II -> III -> IV -> V -> VI -> VII -> VII -> IX -> X (total yield 18%). The configuration at ring D centers (14β,17α) follows from the structure of the starting ketone I and was also checked by comparing diol IV with the sample prepared by an independent route. The epimeric purity at C-17 was carefully monitored during the whole synthesis by 1H NMR spectra (singlet of 18-H3).
Preparation of 1'-C Deuterated Synthons for RNA Synthesis by H-Phosphonate Method Aiming at Two-Dimensional NMR Secondary Structure Studies
Authors: Arnold Luboš , Pressová Martina , Šaman David , Vogtherr Martin , Limmer Stefan
Published: July 2002

1'-C Deuterated H-phosphonate synthons were prepared via a 12-step procedure starting from [1'-2H]ribose. The procedure included nucleosidation of 1'-O-acetyl-2',3',5'-O-tribenzoyl[1'-2H]ribose with appropriately protected nucleobases and preparation of nucleoside-H-phosphonates by slightly modified described procedures. The automated RNA synthesis of 5'-G*C*U*A*U*UUAU-3' and 3'-AC*G*A*U*A*AAGU-5' was performed on a Gene Assembler Plus DNA-synthesizer. These specifically deuterated oligoribonucleotides were subsequently compared with the corresponding non-deuterated sequences using 2D-NMR NOESY spectra. Specific deuterium incorporation resulted in the expected simplification of spectral pattern.
1H, 13C and 15N NMR Spectra of Coupling Products of Benzenediazonium Salts with Aliphatic Nitro Compounds and Study of Their E/Z Isomerism
Authors: Lyčka Antonín
Published: July 2002

The 1H, 13C and 15N NMR spectra have been measured of coupling products of benzenediazonium salts with nitromethane, nitroethane, 1-nitropropane, 2-nitroethanol and of their sodium salts, and the chemical shifts have been unambiguously assigned. The coupling products have been found to exist only in their hydrazone tautomeric forms. Stereospecific behaviour of the coupling constants 2J(15N,1H) and 2J(15N,13C) in the 15N isotopomers and NOESY have been used to differentiate between the E and Z geometrical isomers. The above-mentioned compounds exist as Z isomers in deuteriochloroform and predominantly (>95%) as E isomers in dimethyl sulfoxide, while the sodium salts are present only as E isomers in dimethyl sulfoxide.
Comparison of the Reactivity of Different Sodium Compounds and Ca(OH)2 Towards SO2 and Mixtures of SO2 and NOx
Authors: Mocek Karel , Stejskalová Květoslava , Bach Pavel , Lippert Erich , Bastl Zdeněk , Spirovová Ilona , Erdös Emerich
Published: July 2002

The reactivity of solid substances towards acid gases (SO2, NOx) was studied with a view to finding the best conditions for an efficient removal of the gases. The solids included various sodium compounds (sodium bicarbonate, active soda, sodium carbonate monohydrate, dense soda ash) and Ca(OH)2, and the reaction with sulfur dioxide was examined over a broad range of experimental variables (temperature, gas composition). The reactivity of selected samples was also investigated in reactions with gaseous mixtures containing SO2 and NOx in the dependence on temperature, the SO2/NOx and NO/NO2 ratios and the hydrodynamic conditions of the fixed bed flow reactor. The ESCA and SEM techniques were employed to identify the solid reaction products and to study their evolution as a function of reaction parameters. It was found that with the NaHCO3 precursor, a simultaneous removal of 90% SO2 and nearly 50% NOx is feasible. The results indicate that NaHCO3 shows promise particularly for the purification of waste gases from incinerators and power plants.
Activities of Components in the Ca2MgSi2O7-CaSiO3Molten System
Authors: Kosa Ladislav , Nerád Ivan , Adamkovičová Katarína , Strečko Jozef , Proks Ivo
Published: July 2002

Activities of the components, the Gibbs energy of mixing, and the excess entropy of mixing have been calculated for the Ca2MgSi2O7-CaSiO3 system. The mole fractions of the components were calculated assuming that in the point of the formal component Ca2MgSi2O7, the molar mass of the quasi-real particle in the melt corresponds to its formula molar mass, whereas in the point of the formal component CaSiO3 the molar mass of the quasi-real particle in the melt is 8.5 times higher than as corresponds to its formula. The fact that the enthalpy of mixing is zero whereas the excess entropy of mixing is non-zero suggests that Ca2MgSi2O7-CaSiO3 melts behave as athermal solutions.
The Impact of IMEBORON Conferences on the Development of Boron Chemistry
Authors: Greenwood Norman N.
Published: July 2002

The idea of IMEBORON, a regular series of international meetings on boron chemistry was conceived in Czechoslovakia some 30 years ago and has had a profound and entirely beneficial effect on the development of boron chemistry. The nine conferences which have been held so far (in seven different countries) have nurtured a sense of coherence within the widely differing aspects of the subject and have been particularly important in fostering international respect and collaboration. The high quality of the papers presented, and the friendly atmosphere of the meetings was already firmly established at the first IMEBORON at Castle Liblice near Prague in 1971; this has done much to inspire young research workers, and to encourage their active participation.
Water Photolysis in Rare Gas Environment: The CASPT2 Excited State H2O(A)-Ar Potential
Authors: Nachtigallová Dana , Slavíček Petr , Nachtigall Petr , Jungwirth Pavel
Published: July 2002

The potential energy surface of the first excited state of the water-argon complex is explored at a multireference perturbation theory level as an initial step of the project aimed at the study and control of photodissociation in H2O-Arn (n = 1, 2, ..., 12) clusters. Ab initio calculations, which will serve as a basis for the construction of an analytical force field for dynamical simulations, reveal the anisotropy of the excited state surface and weak potential coupling between intermolecular and intramolecular degrees of freedom. The importance of the "cage effect" is demonstrated.
Ab initio Molecular Dynamics for Determination of Structures of Alkali Metal Clusters and Their Temperatures Behavior; An Example of Li9+
Authors: Bonačič-Koutecký Vlasta , Reichardt Detlef , Pittner Jiří , Fantucci Piercarlo , Koutecký Jaroslav
Published: July 2002

It will be shown that an ab initio molecular dynamics procedure based on gradient corrected density functionals for exchange and correlation and using a Gaussian atomic basis (AIMD-GDF) implemented for parallel processing represents a suitable tool for detailed and accurate investigation of structural and dynamical properties of small systems. Gradients of the Born-Oppenheimer ground state energy, obtained by iterative solution of the Kohn-Sham equations, are used to calculate the forces acting on atoms at each instantaneous configuration along trajectories generated by solving classical equations of motion. Dynamics of different isomers of the Li9+ cluster have been investigated as a function of excess energy. It is shown that different isomers, even those similar in energy, can exhibit different structural and dynamical behavior. The analysis of the simulations leads to the conclusion that structures with a central atom, in particular the centered antiprism of Li9+ exhibit concerted mobility of the peripheral atoms at relatively low excess energy. In contrast, compact tetrahedral type structures show much more rigid behavior at low excess energy. However, the former ones need larger excess of internal energy to undergo isomerizations to geometrically different structures than the latter ones. At the time scale of our simulations we found that for the intermediate excess energies it is "easier" to carry the cluster in the basin of the lowest energy isomer than in the reverse direction. It has been found that the liquid-like behavior in small Li clusters becomes apparent at relatively high temperature in spite of large mobility of their atoms.
Synthesis of 17β-Isoxazolyl Steroids and Spiro[steroid-17,2'-furanone]s
Authors: Baranovsky Alexander V. , Groen Marinus B. , Groot Aede de , Litvinovskaya Raissa P. , Khripach Vladimir A.
Published: July 2002

Synthesis of 17β-isoxazolyl steroids and their transformations into the corresponding spiro[steroid-17,2'-furanone]s are described. The reaction sequence consists of the 1,3-dipolar cycloaddition of a nitrile oxide to mestrenol, dehydration, epoxidation or dihydroxylation, cleavage of the isoxazole moiety and cyclization of intermediate enamino ketones.
Reaction of Nitric Oxide Adsorbed on Platinum Clusters in X Zeolites. Effect of Cluster Size and Nature of Alkali Cations
Authors: Brabec Libor
Published: July 2002

Adsorption and temperature-programmed desorption of NO was studied over Pt/alkali zeolites. Platinum clusters of three different sizes were prepared by different decomposition routes of [Pt(NH3)4]2+ partially ion-exchanged in NaX zeolite. The effect of various alkali ions (Li, Na and K) was also examined. Similarly to platinum supported by alumina, the conversion of adsorbed NO to nitrogen increases with increasing Pt particle size. Increasing electropositivity of the alkali cations shifts the desorption to lower temperatures.
Substituent Effects on Conformational Equilibria: Substituted Thiobenzanilides
Authors: Waisser Karel , Palát Karel , Exner Otto
Published: July 2002

Infrared absorption spectra of 38 thiobenzanilides in tetrachloromethane solutions were recorded in the ν(N-H) region. From the integrated absorption intensity of the computer-resolved N-H bands, the abundance of the Z and E conformations was calculated. The values of pertinent log KC depend on substitution in an unexpected way which cannot be described by the Hammett equation or by any other known type of modified constants σ. The only regularity observed is that the substituent effects from the two benzene rings of thioanilide are additive with a remarkable precision. The ν(N-H) frequencies are not much sensitive to substitution and the dependence is not simple: only ν(N-H) of the E conformer depend on substitution in a regular way.
Synthesis of (20S)-2α,3α-Dihydroxy-6-oxo-7-oxa-7a-homo-5α-pregnane-20-carboxylic Acid as a Brassinosteroid Part of Ligands for Binding to Affinity Chromatography Carriers
Authors: Kohout Ladislav , Chodounská Hana , Macek Tomáš , Strnad Miroslav
Published: July 2002

(20S)-2α,3α-Dihydroxy-6-oxo-7-oxa-7a-homo-5α-pregnane-20-carboxylic acid (12) as a brassinosteroid ligand for affinity chromatography carriers was synthesized from bisnorcholenic acid. The brassinolide activity in the bean second internode bioassay of the synthesized (20S)-5α-pregnane-20-carboxylic acid derivatives is also described.
Intussusception associated with bacterial meningitis
Authors: Crushell E , Flanagan O , Devins M , Dunne K , Gleeson J
Published: July 2002

Despite its common association with viral illnesses, intussusception has only rarely been found in the presence of bacterial infections. Two infants are described, both of whom were admitted to hospital with bilious vomiting, drowsiness, and dehydration. Both infants required urgent intravenous volume expansion. Intussusception was confirmed, and reduction was achieved by enema in both cases. Recovery was slow, and one infant developed a seizure. Evidence of meningococcal meningitis was found in both, with septicaemia in one. Neurological outcome is normal to date, and there has been no recurrence of intussusception in either case.
Physiological and anthropometric characteristics of amateur rugby league players
Authors: Gabbett Tim J
Published: July 2002

Objectives—To investigate the physiological and anthropometric characteristics of amateur rugby league players.

Methods—Thirty five amateur rugby league players (19 forwards and 16 backs) were measured for height, body mass, percentage body fat (sum of four skinfolds), muscular power (vertical jump), speed (10 m and 40 m sprint), and maximal aerobic power (multistage fitness test). Data were also collected on match frequency, training status, playing experience, and employment related physical activity levels.

Results—The 10 m and 40 m sprint, vertical jump, percentage body fat, and multistage fitness test results were 20–42% poorer than previously reported for professional rugby league players. Compared with forwards, backs had significantly (p<0.01) lower body mass (79.7 (74.7–84.7) kgv90.8 (86.2–95.4) kg) and significantly (p<0.01) greater speed during the 40 m sprint (6.45 (6.35–6.55)v6.79 (6.69–6.89) seconds). Values for percentage body fat, vertical jump, 10 m sprint, and maximal aerobic power were not significantly different (p>0.05) between forwards and backs. When compared with professional rugby league players, the training status of amateur rugby league players was 30–53% lower, with players devoting less than three hours a week to team training sessions and about 30 minutes a week to individual training sessions. The training time devoted to the development of muscular power (about 13 minutes a week), speed (about eight minutes a week), and aerobic fitness (about 34 minutes a week) did not differ significantly (p>0.05) between forwards and backs. At the time of the field testing, players had participated, on average, in one 60 minute match every eight days.

Conclusions—The physiological and anthropometric characteristics of amateur rugby league players are poorly developed. These findings suggest that position specific training does not occur in amateur rugby league. The poor fitness of non-elite players may be due to a low playing intensity, infrequent matches of short duration, and/or an inappropriate training stimulus.
Examining consent within the patient-doctor relationship
Authors: Habiba Marwan A
Published: July 2002

The notion of consent which rose to the forefront in biomedical ethics as an attempt to safeguard patients' autonomy, is relatively new. The notion itself requires qualification, for it precludes neither duress nor ignorance. More seriously, I argue here that consent is redundant except in situations where paternalism prevails. Paradoxically, these are the very situations where it may be difficult to uphold or to verify voluntary consent. I suggest that a request-based relationship has the potential to overcome these difficulties. It enhances patients' participation in decision making, requires that the patients remain in command and avoids their subordination. Request is also more conducive to treatments that are representative of patients' own values and perceptions. In practice, what one wants and what one agrees to, often concur. But these are not conceptually identical issues, and they carry important differences of emphasis.
Fatal work related injuries in agricultural production and services to agriculture sectors of New Zealand, 1985–94
Authors: Horsburgh S , Feyer A-M , Langley J D
Published: July 2002

OBJECTIVES

To describe work related fatal injuries to agricultural workers in New Zealand to identify priority areas for further research and injury control measures.

METHODS

Injury deaths in New Zealanders aged 15–84 inclusive for the period 1985–94 were identified and the coroner's files for these obtained. These files were then reviewed to determine whether the death arose as a result of work activities. Those deaths considered to be work related were coded for information relating to decedent demographics and the circumstances of the fatal injury. Work related deaths from injury occurring in the agricultural production and services to agriculture sectors were analysed.

RESULTS

The rate of fatal injuries to male agricultural workers over the study period was 21.2/100 000, with injury deaths in the agricultural sectors accounting for nearly a quarter of all work related fatal injuries in New Zealand in that time. There was no significant decline in fatal injuries to agricultural workers in the study decade. Workers in the 65–84 age bracket were at substantially higher risk of fatal injury than other age groups. Machinery and motor vehicles were commonly associated with fatal injury, with overturns on or next to embankments and slopes being the most frequent scenario.

CONCLUSIONS

The results of this study highlight fatal injuries in older workers and machinery incidents (particularly tractors overturning) as priority areas for further research into contributing factors and injury control measures.
Mechanisms of bacterial pathogenicity
Authors: Wilson J W , Schurr M J , LeBlanc C L , Ramamurthy R , Buchanan K L , Nickerson C A
Published: July 2002

Pathogenic bacteria utilise a number of mechanisms to cause disease in human hosts. Bacterial pathogens express a wide range of molecules that bind host cell targets to facilitate a variety of different host responses. The molecular strategies used by bacteria to interact with the host can be unique to specific pathogens or conserved across several different species. A key to fighting bacterial disease is the identification and characterisation of all these different strategies. The availability of complete genome sequences for several bacterial pathogens coupled with bioinformatics will lead to significant advances toward this goal.
Troponin T elevation in lobar lung disease
Authors: Weinberg I , Cukierman T , Chajek-Shaul T
Published: July 2002

Two patients with a rise in cardiac troponin T (cTnT) concentrations during the course of lobar pneumonia, without any evidence of acute coronary syndrome or renal failure, are presented. The increase in cTnT concentration is considered a highly sensitive marker of cardiac injury, although it may also rise in other conditions and as a result of lobar pneumonia. Thus, this effect should be considered when the possibility of acute coronary syndrome in such patients is addressed.
Undermethylated DNA as a source of microsatellites from a conifer genome
Authors: Zhou Y , Bui T , Auckland L D , Williams C G
Published: July 2002

Developing microsatellites from the large, highly duplicated conifer genome requires special tools. To improve the efficiency of developing Pinus taeda L. microsatellites, undermethylated (UM) DNA fragments were used to construct a microsatellite-enriched copy library. A methylation-sensitive restriction enzyme, McrBC, was used to enrich for UM DNA before library construction. Digested DNA fragments larger than 9 kb were then excised and digested with RsaI and used to construct nine dinucleotide and trinucleotide libraries. A total of 1016 microsatellite-positive clones were detected among 11 904 clones and 620 of these were unique. Of 245 primer sets that produced a PCR product, 113 could be developed as UM microsatellite markers and 70 were polymorphic. Inheritance and marker informativeness were tested for a random sample of 36 polymorphic markers using a three-generation outbred pedigree. Thirty-one microsatellites (86%) had single-locus inheritance despite the highly duplicated nature of the P. taeda genome. Nineteen UM microsatellites had highly informative intercross mating type configurations. Allele number and frequency were estimated for eleven UM microsatellites using a population survey. Allele numbers for these UM microsatellites ranged from 3 to 12 with an average of 5.7 alleles/locus. Frequencies for the 63 alleles were mostly in the lowcommon range; only 14 of the 63 were in the rare allele (q < 0.05) class. Enriching for UM DNA was an efficient method for developing polymorphic microsatellites from a large plant genome.Key words: hypomethylation, simple-sequence repeats, repetitive DNA, Pinus taeda L., gymnosperms.
Velocity distribution in decelerating flow over rough surfaces
Authors: Balachandar R , Hagel K , Blakely D
Published: July 2002

An experimental program was undertaken to study turbulent boundary layers formed in decelerating open channel flows. The flows over a smooth surface and three rough surfaces were examined. Tests were conducted at a subcritical Froude number (~0.2) and varying depth Reynolds numbers (64 000 < Red < 88 000). The corresponding momentum thickness Reynolds numbers were small (1000 < Reθ < 2100). The velocity measurements were undertaken using a one-component laser-Doppler anemometer. Variables such as the shear velocity, the longitudinal mean velocity, Coles' wake parameter, and Clauser's shape parameter were examined. Three different methods for determining the friction velocity were investigated for use in sloping channels. The inner region of the boundary layer was found not to be influenced by the channel slope. The log-law slope and intercept were found to be the same as that noted for canonical boundary layers. The skin friction coefficient for the sloping smooth surface tests was found to be slightly higher than that noticed for flow over a horizontal surface. As indicated by the wake parameter, the free surface, the channel slope, and the roughness of the channel affected the outer region of the boundary layer.Key words: decelerating flow, open channel, log-law, friction velocity, power law.
Isentropic compressibility and viscosity of aqueous and methanolic lithium chloride solutions
Authors: Wahab Abdul , Mahiuddin Sekh
Published: July 2002

Densities, speeds of sound, and viscosities of aqueous and methanolic lithium chloride solutions were measured as functions of concentration, m (mol kg1) (0.3911 [Formula: see text] m [Formula: see text] 19.47) and temperature (273.15 [Formula: see text] T [Formula: see text] 323.15 K). Measured values of the density, speeds of sound, and viscosity agree well with previously reported data. The isentropic compressibility isotherms for the aqueous solutions converge at a particular concentration, in the temperature range of the study, providing crucial information regarding the solvation behaviour of the ions. However, for the methanol solutions, the isentropic compressibility isotherms decrease smoothly with concentration and converge on extrapolation. Anion solvation controls the viscosity processes at low temperatures whereas cation solvation controls the same at high temperatures. Total primary solvation numbers of lithium chloride in water and methanol were estimated to be 6.0 and 1.9, respectively.Key words: lithium chloride, speeds of sound, viscosity, isentropic compressibility, solvation number.
ON MESSAGE PACKAGING IN TASK SCHEDULING FOR DISTRIBUTED MEMORY PARALLEL MACHINES
Authors: FUJIMOTO NORIYUKI , BABA TOMOKI , HASHIMOTO TAKASHI , HAGIHARA KENICHI
Published: July 2002

In this paper, we report a performance gap betweeen a schedule with small makespan on the task scheduling model and the corresponding parallel program on distributed memory parallel machines. The main reason of the gap is the software overhead in the interprocessor communication. Therefore, speedup ratios of schedules on the model do not approximate well to those of parallel programs on the machines. The purpose of the paper is to get a task scheduling algorithm that generates a schedule with good approximation to the corresponding parallel program and with small makespan.

For this purpose, we propose algorithm BCSH that generates only bulk synchronous schedules. In those schedules, no-communication phases and communication phases appear alternately. All interprocessor communications are done only in the latter phases, and thus the corresponding parallel programs can make better use of the message packaging technique easily. It reduces many software overheads of messages form a source processor to the same destination processor to almost one software overhead, and improves the performance of a parallel program significantly.

Finally, we show some experimental results of performance gaps on BCSH, Kruatrachue's algorithm DSH, and Ahmad et al's algorithm ECPFD. The schedules by DSH and ECPFD are famous for their small makespans, but message packaging can not be effectively applied to the corresponding program. The results show that a bulk synchronous schedule with small makespan has advantages that the gap is small and the corresponding program is a high performance parallel one.
AN ALGORITHM FOR FINDING LONGEST CYCLES IN CERTAIN BIPARTITE GRAPHS
Authors: WONG PAK-KEN
Published: July 2002

Let G be a connected bipartite graph with with bipartition (X, Y) such that |X| ≥ |Y| (≥ 2). Put n = |X|, m = |Y| and l = m + n. Suppose that, for all vertices x ∈ X and y ∈ Y, dist(x,y) = 3 implies d(x) + d(y) ≥ n + 1. We show that G contains a cycle of length 2m. We also give an efficient algorithm to obtain such a cycle. The complexity of this algorithm is O(l3). In case m = n, we find a hamiltonian cycle of G. This generalizes a result given in [10].
THE MAXIMUM TRAVELING SALESMAN PROBLEM ON BANDED MATRICES
Authors: BLOKH DAVID , LEVNER EUGENE
Published: July 2002

We investigate the Maximum Traveling Salesman Problem on banded distance matrices. A (p, q)-banded matrix has all its non-zero elements contained within a band consisting of p diagonals above the principal diagonal and q diagonals below it. We investigate the properties of the problem and prove that the number K of different permutations which can be optimal solutions for different instances of the problem, is exponential in n where n is the problem size (= the number of cities). For the Maximum-TSP on the (2, 0)-banded matrices, K=O(λn) where 1.7548 <λ< 1.7549, whereas on the (1, 1)-banded matrices K=O(λn) where 1.6180 <λ< 1.6181. Using recursive equations, we derive a linear-time algorithm that exactly solves the Maximum-TSP on the (2, 0)-banded distance matrices.
A SELF-STABILIZING ALGORITHM FOR FINDING ARTICULATION POINTS
Authors: KARAATA MEHMET HAKAN
Published: July 2002

In this paper, a self-stabilizing algorithm is presented for finding the articulation points of a connected undirected graph on a distributed or network model of computation after O(n2|E|) moves. The algorithm is resilient to transient faults and does not require initialization. A correctness proof of the algorithm is also presented. The paper concludes with remarks on issues such as the time complexity of the algorithm and open problems.
UNIQUENESS IN MOMENT — PROBLEMS OVER NUCLEAR SPACES AND WEAK CONVERGENCE OF PROBABILITY MEASURES
Authors: BRÜNING ERWIN A. K.
Published: July 2002

Based on results from the theory of ordered (topological) vector spaces and on the theory of Fourier transforms of Radon probability measures (Bochner–Minlos–Schwartz) we present a solution of infinite dimensional moment problems over real nuclear spaces E. Both moment and truncated moment problems are treated simultaneously. In both cases uniqueness of the representing measure is characterized in terms of conditions on the set of moments directly. Concentration of the representing measures is expressed through continuity properties of the second moment. This is finally applied to characterize weak convergence of sequences of measures in terms of pointwise convergence of the associated sequence of moment functionals on the tensor algebra over E.
QUANTUM THEORY, HYPERBOLIC GEOMETRY AND RELATIVITY
Authors: LUNDBERG LARS-ERIK
Published: July 2002

We construct a Lorentz-invariant quantum theory on velocity hyperboloids, with Schrödinger theory as its Euclidean analogue and with the property that the scattering operator is Poincaré invariant. This allows us to introduce the classical space-time concept for a macroscopic description of some properties of the microscopic scattering operator.

This gives a completely novel approach to the relation between microscopic quantum theory and classical macroscopic sapce-time concepts. Hyperbolic integral geometry will be developed and used extensively in the construction of the theory, which might be called hyperbolic quantum theory.

We stress that this is a radically new kind of relativistic quantum theory, where the term, relativistic, has a new meaning, dictated by the quantum theory. Special relativity was extracted from Maxwell's classical theory and should be properly adapted to quantum theory.
GENERATIONS AND SUPER COHOMOLOGY
Authors: TAHIRI M.
Published: July 2002

We determine the number of generations in relation to super cohomology of the base supermanifold of the principal superfibre bundle describing gauge theories with ghosts.
APPLICATION OF THE RECOMMENDATION ARCHITECTURE TO TELECOMMUNICATIONS NETWORK MANAGEMENT
Authors: COWARD ANDREW , GEDEON TOM , KENWORTHY WILLIAM
Published: July 2002

The recommendation architecture has been proposed as a system architecture which can enable a system to learn to perform a complex combination of interrelated functions. The capability of a system with the recommendation architecture to learn to manage complex telecommunication backbone networks has been investigated. A network model with a number of nodes and links and carrying realistic but randomly generated traffic was used as the target for the management system. Traffic data taken from the model was used as input to the recommendation architecture system. The traffic data was organized into inputs once every 5 minutes, and the management system organized these inputs into a hierarchy of repetition similarity. It was demonstrated that the outputs of this hierarchy provided information on the condition of the network. This output information was a compressed version of the inputs which correlated with major network conditions.
INNER STRUCTURE OF GAUSS–BONNET–CHERN THEOREM AND THE MORSE THEORY
Authors: DUAN YI-SHI , ZHANG PENG-MING
Published: July 2002

We define a new one-form HA based on the second fundamental tensor [Formula: see text], the Gauss–Bonnet–Chern form can be novelly expressed with this one-form. Using the ϕ-mapping theory we find that the Gauss–Bonnet–Chern density can be expressed in terms of the δ-function δ(ϕ) and the relationship between the Gauss–Bonnet–Chern theorem and Hopf–Poincaré theorem is given straightforwardly. The topological current of the Gauss–Bonnet–Chern theorem and its topological structure are discussed in details. At last, the Morse theory formula of the Euler characteristic is generalized.
ON SECTIONALLY-ELLIPTICAL CONICAL SPACE–TIMES
Authors: ROMERO C.
Published: July 2002

We consider sectionally-elliptical conical space–times and compute the energy–momentum tensor of the source generating such configurations. It turns out that the problem can be reduced to the calculation of the Gaussian curvature of the bidimensional elliptical cone defined by the foliation t = const. , z = const. We then employ the method of smoothing the conical singularity by taking a sequence of regular bidimensional manifolds in order to compute the curvature. Finally, we conclude that the gravitational effects produced by sectionally-elliptical and sectionally-circular conical space–times are completely equivalent.
ON THE MASS RELATION OF A MESON NONET
Authors: LI DE-MIN , YU HONG , SHEN QI-XING
Published: July 2002

It is pointed out that the omission of the effects of the transition between quarkonia or the assumption that the transition between quarkonia is flavor-independent would result in the inconsistent results for the pseudoscalar meson nonet. It is emphasized that the mass relation of the non-ideal mixing meson nonets should incorporate the effects of the flavor-dependent transition between quarkonia. The new mass relations of a meson nonet are presented.
OBTAINING A LIGHT-LIKE PLANAR GAUGE
Authors: SUZUKI ALFREDO T. , BENTÍN RICARDO
Published: July 2002

In the usual and current understanding of planar gauge choices for Abelian and non-Abelian gauge fields, the external defining vector nμ can either be space-like (n2 < 0) or time-like (n2>0) but not light-like (n2=0). In this work we propose a light-like planar gauge that consists of defining a modified gauge-fixing term, ℒ GF , whose main characteristic is a two-degree violation of Lorentz covariance arising from the fact that four-dimensional space–time spanned entirely by null vectors as basis necessitates two light-like vectors, namely nμ and its dual mμ, with n2=m2=0, n·m≠0, say, e.g. normalized to n·m=2.
θ-TERM AND COSMOLOGICAL CONSTANT FROM CJD ACTION
Authors: MAHATO PRASANTA
Published: July 2002

In the gravity without metric formalism of Capovilla, Jacobson and Dell, the topological θ-term appears through a canonical transformation. The origin of this canonical transformation is probed here. It is shown here that when θ-term appears cosmological, λ-term also appears simultaneously.
DIFFUSION OF SCALAR PARTICLES IN JANIS–NEWMAN–WINICOUR–WYMAN GRAVITATIONAL FIELD AND GRBs
Authors: LAMBIASE G. , CAPOZZIELLO S. , CARLONI S.
Published: July 2002

The propagation of a boson particle in the Janis–Newman–Winicour–Wyman (JNWW) gravitational field is analyzed. We derive the wave function of the scalar particle, and the effective potential experienced by quantum particles. Besides, we show that the probability to find the scalar particle near the region where the naked singularity is finite. Finally, these results are proposed as a model to study the gamma ray bursts (GRBs) physics.
CONFINEMENT AND SCREENING OF THE SCHWINGER MODEL ON THE POINCARÉ HALF PLANE
Authors: SADJADI H. MOHSENI , ALIMOHAMMADI M.
Published: July 2002

We discuss the confining features of the Schwinger model on the Poincaré half plane. We show that despite the fact that the expectation value of the large Wilson loop of massless Schwinger model displays perimeter behavior, the system can be in confining phase due to the singularity of the metric at horizontal axis. It is also shown that in the quenched Schwinger model, the area dependence of the Wilson loop, in contrast to the flat case, is a not a sign of confinement and the model has a finite energy even for large external charges separation. The presence of dynamical fermions cannot modify the screening or the confining behavior of the system. Finally we show that in the massive Schwinger model, the system is again in screening phase. The zero curvature limit of the solutions is also discussed.
LORENTZ COVARIANT FORMULATION IN CLASSICAL THEORY OF CANONICAL QCD
Authors: Ozaki Hiroshi
Published: July 2002

The canonical formalism in classical theory of QCD is developed on a space-like hypersurface. The Poisson bracket on the space-like hypersurface is defined and it plays an important role to describe every algebraic relation in the canonical formalism into Lorentz covariant form. By converting the Poisson bracket on the hypersurface to four-dimensional commutator, we can pass over to QCD in the Heisenberg picture without spoiling the Lorentz covariance.
SCALAR NONLUMINOUS MATTER IN GALAXIES
Authors: LEE BYUNG JOO , LEE TAE HOON
Published: July 2002

As a candidate for dark matter in galaxies, we study an SU(3) triplet of complex scalar fields which are nonminimally coupled to gravity. In the spherically symmetric static space–time where the flat rotational velocity curves of stars in galaxies can be explained, we find simple solutions of scalar fields with SU(3) global symmetry broken to U(1) × U(1), in an exponential scalar potential, which will be useful in a quintessence model of the late-time acceleration of the universe.
THE LOW-TEMPERATURE PHASE OF THE HEISENBERG ANTIFERROMAGNET IN A FERMIONIC REPRESENTATION
Authors: AZAKOV S. , DILAVER M. , ÖZTAŞ A. M.
Published: July 2002

Thermal properties of the ordered phase of the spin-1/2 isotropic Heisenberg Antiferromagnet on a d-dimensional hypercubical lattice are studied within the fermionic representation when the constraint of a single occupancy condition is taken into account by the method suggested by Popov and Fedotov. Using a saddle point approximation in the path integral approach we discuss not only the leading order but also the fluctuations around the saddle point at one-loop level. The influence of taking into account the single occupancy condition is discussed at all steps.
σ-MODEL ANALYSIS OF QUANTUM SPIN LADDERS
Authors: SYLJUÅSEN OLAV F.
Published: July 2002

The σ-model approach to quantum spin ladders, described here, allows one to analytically calculate correlation lengths and gaps for both even- and odd-legged ladders, at any temperature. Comparison with high precision quantum Monte Carlo simulations show that these analytic results are surprisingly accurate. A self-contained account of these analytic methods is presented.
THE EFFECT OF TIME DELAY ON SPATIOTEMPORAL DYNAMICS IN ONE-DIMENSIONAL DISCRETE EXCITABLE MEDIA
Authors: CHUNG TAE-HOON , KIM SEUNGWHAN
Published: July 2002

We investigate the effect of time delay on spatiotemporal dynamics in one-dimensional discrete excitable media with local delayed-interactions using coupled sine circle-maps. With the help of the stability analysis and numerical calculation of the pattern complexity entropy, we construct the phase diagram in the parameter space time delay and the nonlinear coupling. We find that the time delay affects the existence and stability of various regular states including homogeneously phase-locked and checkerboard states. In particular, the time delay induces the breakup of the homogeneously phase-locked state into spatiotemporal intermittency and the occurrence of multi-stability that depends on the winding number.
PROBING BOSE-EINSTEIN CONDENSATES WITH OPTICAL BRAGG SCATTERING
Authors: STAMPER-KURN D. M. , CHIKKATUR A. P. , GÖRLITZ A. , GUPTA S. , INOUYE S. , STENGER J. , PRITCHARD D. E. , KETTERLE W.
Published: July 2002

Gaseous Bose-Einstein condensates are a macroscopic condensed-matter system which can be understood from a microscopic, atomic basis. We present examples of how the optical tools of atomic physics can be used to probe properties of this system. In particular, we describe how stimulated light scattering can be used to measure the coherence length of a condensate, to measure its excitation spectrum, and to reveal the presence of pair excitations in the many-body condensate wavefunction.
THERMODYNAMIC CRITICAL FIELD OF La2-xSrxCuO4
Authors: HUH YUNG M. , FINNEMORE D. K.
Published: July 2002

Thermodynamic critical fields, Hc, have been measured for the La2-xSrxCuO4 family of superconductors in order to determine the changes in free energy of the system as the number of carriers is reduced. Magnetization vs. magnetic field curves are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. Magnetization vs. field data are then fit to theoretical models to determine the thermodynamic critical fields. As the Sr concentration is changed from x=0.10 to 0.23, the values of Hc(T=0) goes through a maximum at optimum doping in a manner similar to the Tc vs x curve. The ratio of Hc(T = 0)/Tc also peaks in the region of x somewhat larger than optimum doping. As the value of x increases from underdoped to optimum doping, the cross-over temperature in the Msc vs. T curve, T*, approaches the transition temperature. In the overdoped regime there is no crossing in these Msc vs. T curves.
MAGNETIZATION INHOMOGENEITIES GENERATED BY DEFECTS AT THE SURFACE OF A FERROMAGNET
Authors: SOBOLEV V. L. , IVANOVA S. V. , HUANG H. L.
Published: July 2002

Inhomogeneous magnetization generated by point defects situated at the surface of a ferromagnet is studied. We analyzed two cases with different boundary conditions for the magnetization at the crystal surface. The first case is when the magnetic moment is rigidly fixed at the surface and the second is when the magnetic moment is determined by the interactions in the bulk of the crystal.
EXPLORING THE ANTISTICKING PROPERTIES OF SOLID LUBRICANT THIN FILMS IN TRANSFER MOLDING
Authors: Zhang Sam , Zeng Xianting , Tang Zhenggui , Tan Ming Jen
Published: July 2002

In the plastic molding industry, plastic parts like pager and handphone cases, plastic containers, etc. are formed in a mold by applying temperature and pressure. The transfer molding is the standard workhorse for the electronics industry. Although the transfer molding is widely used, it is far from being optimized. Mold sticking is a serious practical problem in this industry. A solution to the problem is to apply mold-releasing agents on the mold to act as a lubricant layer between the plastic and the mold. This easily results in stains and degraded surface finish. This paper investigates the effectiveness of solid thin films on reducing the adhesion between polymer and mold steel of different surface roughness. WS2, MoS2, and DLC coatings are deposited on test surfaces via unbalanced magnetron sputtering before polymer blocks are molded on and pulled apart using an Instron Machine. The force required to separate the plastic part and the mold steel is used as an indication of the stickiness. After the separation, the coating surface is also examined under microscope for stains and polymer residues. The coatings are characterized using Raman spectroscopy and contact angle measurements. Generally, the stickiness increases with initial surface roughness for all coatings. Initial test indicates that the DLC coating has the highest contact angle with water (100°) and the best anti-sticking properties among the samples tested, and could reduce the stickiness by 80% as compared to bare steel.