bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of
Helicobacter pylori
in Gastric Mucosa of Patients with Gastroduodenal Diseases by PCR-Restriction Analysis Using the RNA Polymerase Gene (
rpoB
)
Authors: Lim Chang-Young , Lee Keun-Hwa , Cho Myung-Je , Chang Myung-Woong , Kim Seok-Yong , Myong Na-Hye , Lee Woo-Kon , Rhee Kwang-Ho , Kook Yoon-Hoh
Published: July 2003

A novel PCR restriction analysis method using the RNA polymerase β-subunit- coding gene (
rpoB
) was employed to both detect and identify
Helicobacter pylori
in biopsy specimens and culture isolates. The
rpoB
DNAs (458 bp) were specifically amplified by PCR with the
Helicobacter
-specific primers (HF and HR). Based on the determined
rpoB
sequences of the culture isolates, an
H. pylori
-specific restriction site,
Tru
9I, was found.
H. pylori
can be identified by observing two discernible DNA fragments (288 and 138 bp) after
Tru
9I digestion and agarose gel electrophoresis. The
rpoB
PCR and subsequent restriction analysis (PRA) enabled the specific detection and identification of
H. pylori
in biopsy specimens from patients with gastroduodenal diseases. The
rpoB
PRA conferred a compatible or a slightly higher positive rate (53.7%) than did the
Campylobacter
-like organism (CLO) test (50.4%) and
glmM
PCR (48.8%), suggesting that it is useful for diagnosing an
H. pylori
infection without culture in the clinical laboratory.
Analysis of Genetic Identity of North AmericanAnaplasma phagocytophilumStrains by Pulsed-Field Gel Electrophoresis
Authors: Dumler J. S. , Asanovich K. M. , Bakken J. S.
Published: July 2003

Biological and geographic heterogeneity of anthropozoonosis caused byAnaplasma phagocytophilumis poorly understood. Seven North AmericanA. phagocytophilumstrains were compared by PFGE. The average genome size was 1.58 Mbp, and restriction patterns were identical. New World strains ofA. phagocytophilumhave a large genome and a high degree of genetic uniformity.
Cross-Reactivity of the PLATELIACANDIDAAntigen Detection Enzyme Immunoassay with Fungal Antigen Extracts
Authors: Rimek Dagmar , Singh Jagpal , Kappe Reinhard
Published: July 2003

We studied the specificity of the PLATELIACANDIDAAg enzyme immunoassay by using 130 isolates of 63 clinically relevant fungal species. Antigen extracts of sevenCandidaspp. (Candida albicans,C. dubliniensis,C. famata,C. glabrata,C. guilliermondii,C. lusitaniae, andC. tropicalis) repeatedly yielded positive reactions (>0.5 ng/ml).Geotrichum candidumandFusarium verticillioideswere found to yield borderline-positive reactions (0.25 to 0.50 ng/ml). Antigen preparations from the other 54 fungal species, including yeasts, molds, dermatophytes, and dimorphic fungi, did not cross-react in the assay.
Surveillance of Rotavirus Strains in Rio de Janeiro, Brazil, from 1997 to 1999
Authors: Santos Norma , Soares Caroline C. , Volotão Eduardo M. , Albuquerque Maria Carolina M. , Hoshino Yasutaka
Published: July 2003

One hundred fifty-seven (23%;n= 678) rotavirus-positive stool samples were collected between March 1997 and December 1999 in the cites of Rio de Janeiro and Niterói. Rotaviruses in 143 (91%) samples were genotyped by reverse transcription-PCR for G and/or P specificity. Rotaviruses in the majority of G-P-typeable samples (73.3%; 74 of 101) were identified as having globally common genotypes G1P[8], G2P[4], G3P[8], and G4P[8]. Unusual strains such as G1P[9], G2[P8], G3P[9], and G9P[4] strains were detected in 8.9% (9 of 101) of the samples. Genotypes G9P[8], G9P[6], and a mixture of G9 and other G or P types represented 15.9% (25 of 157) of the isolates. Mixed infections were detected in 25 (15.9%) samples, and rotaviruses in 15 samples (9.6%) were not typed.
Outbreak of Carbapenem-Resistant
Acinetobacter baumannii
Producing the OXA-23 Enzyme in Curitiba, Brazil
Authors: Dalla-Costa Libera M. , Coelho Juliana M. , Souza Helena A. P. H. M. , Castro Maria E. S. , Stier Christiane J. N. , Bragagnolo Karin L. , Rea-Neto Alvaro , Penteado-Filho Sergio R. , Livermore David M. , Woodford Neil
Published: July 2003

Carbapenem-resistant
Acinetobacter baumannii
isolates were obtained from eight patients in two hospitals in Curitiba, Brazil. The isolates were multiresistant, belonged to a single strain, and produced the OXA-23 carbapenemase. Treatment options were limited, although the isolates were susceptible to polymyxin B in vitro. The strain contributed to the deaths of five patients.
Suboptimal Detection of Influenza Virus in Adults by the Directigen Flu A+B Enzyme Immunoassay and Correlation of Results with the Number of Antigen-Positive Cells Detected by Cytospin Immunofluorescence
Authors: Landry Marie L. , Ferguson David
Published: July 2003

To provide 24-h influenza diagnosis for adults presenting to the emergency department, the Directigen Flu A+B enzyme immunoassay (EIA) was performed in the chemistry laboratory during the night shift. Nasopharyngeal swabs were retested by cytospin-enhanced direct immunofluorescence (DFA; SimulFluor respiratory screen) when the virology laboratory opened. The influenza EIA detected 16 influenza A virus infections, whereas cytospin-enhanced DFA detected 31 influenza A virus infections as well as 3 respiratory syncytial virus, 2 adenovirus, and 1 parainfluenza virus infections. A positive EIA result usually correlated with 50 or more influenza virus cells positive by DFA.
Quality Control Limits for Fluconazole Disk Susceptibility Tests on Mueller-Hinton Agar with Glucose and Methylene Blue
Authors: Barry A. , Bille J. , Brown S. , Ellis D. , Meis J. , Pfaller M. , Rennie R. , Rinaldi M. , Rogers T. , Traczewski M.
Published: July 2003

An international collaborative study was performed in order to propose quality control limits for fluconazole disk diffusion susceptibility tests on Mueller-Hinton agar with 2% glucose and 0.5 μg of methylene blue per ml. The supplements may be added before autoclaving the agar, or Mueller-Hinton agar plates may be flooded with a glucose-methylene blue solution. Replicate tests on both types of agar plates generated data to propose zone size limits for tests of
Candida parapsilosis
ATCC 22019 (22 to 33 mm),
C. tropicalis
ATCC 750 (26 to 37 mm), and
C. albicans
ATCC 90028 (28 to 39 mm).
C. krusei
ATCC 6258 was not useful for this purpose.
Molecular Analysis of
Clostridium difficile
Strains Isolated from 18 Cases of Recurrent
Clostridium difficile
-Associated Diarrhea
Authors: Tang-Feldman Yajarayma , Mayo Susan , Silva, Joseph , Cohen Stuart H.
Published: July 2003

Recurrence of
Clostridium difficile
-associated diarrhea (CDAD) occurs in 15 to 20% of patients after discontinuation of treatment. Arbitrarily primed PCR was used to investigate the epidemiology of recurrent CDAD in 18 patients. Reinfection with a new strain occurred in 6 of 18 patients (33.3%), while 12 patients relapsed with the original strain shortly after discontinuation of treatment. These data suggest that reinfection with exogenous
C. difficile
is a common problem and that not all recurrences are due to relapse.
Use of Amplified Ribosomal DNA Restriction Analysis for Identification of
Ralstonia
and
Pandoraea
Species: Interest in Determination of the Respiratory Bacterial Flora in Patients with Cystic Fibrosis
Authors: Segonds Christine , Paute Sandrine , Chabanon Gérard
Published: July 2003

The recovery of
Ralstonia
and
Pandoraea
species from respiratory tract cultures of patients with cystic fibrosis has recently been reported. These species are difficult to identify, and especially to differentiate from
Burkholderia cepacia
complex organisms, with classical methods. The discriminatory power of amplified ribosomal DNA restriction analysis (ARDRA) within the two genera was assessed by comparing the restriction profiles of reference strains of each species by using a panel of six enzymes already proven suitable for the identification of
Burkholderia
species. ARDRA provided differentiation of all the
Ralstonia
species tested and of
Pandoraea norimbergensis
.
Pandoraea
species
P. pnomenusa
,
P. sputorum
,
P. pulmonicola
, and
P. apista
were not discriminated to the species level. This method allowed the identification of five clinical isolates recovered from French cystic fibrosis patients as
Ralstonia mannitolilytica
.
Evaluation of Fungal Burden in Experimental Paracoccidioidomycosis by Using the Fluorescent Dye Blankophor
Authors: Nishikaku Angela Satie , Burger Eva
Published: July 2003

The fungal load in organs and blood of susceptible and resistant mice infected withParacoccidioides brasiliensiswas quantitated by using the optical brightener Blankophor and compared with CFU counts. Fluorescent staining of fungal cells proved to be a quick and easy procedure, suitable for evaluation of paracoccidioidomycotic infection.
Isolation of
Candida dubliniensis
in an Aboriginal Community in Ontario, Canada
Authors: Montour Laura , Tey Rovena , Xu Jianping
Published: July 2003

This study reports the first isolation of
Candida dubliniensis
from North American Indians. Of 39 healthy human hosts sampled, two had
C. dubliniensis
. Genotypic analysis identified polymorphisms in these strains and differences from two reference strains. Our results suggest that yeast populations from indigenous communities in North America may be unique.
Necrotizing Fasciitis Due to
Vibrio alginolyticus
in an Immunocompetent Patient
Authors: Gomez Juan M. , Fajardo Roosevelt , Patiño Jose F. , Arias Cesar A.
Published: July 2003

We describe a patient with a history of asthma and remote use of steroids the development of necrotizing fascitis due to
Vibrio alginolyticus
after an injury from a coral reef during bathing in the Caribbean Sea off Colombia. The patient recovered with aggressive surgical debridement and antibiotics.
Osteomyelitis Caused by
Bartonella henselae
Genotype I in an Immunocompetent Adult Woman
Authors: Woestyn Sophie , Moreau Michel , Munting Everard , Bigaignon Geoffroy , Delmée Michel
Published: July 2003

We report the first description of osteomyelitis due to
Bartonella henselae
genotype I in an immunocompetent middle-aged woman. The diagnosis was established by serology, histopathology, and PCR analysis of osseous and lymph node tissues. The mycobacteria growth indicator tube inoculated with the lymph node aspirate was used for PCR analysis.
Neonatal Sepsis Caused by
Streptococcus bovis
Variant (Biotype II/2): Report of a Case and Review
Authors: Gavin Patrick J. , Thomson, Richard B. , Horng Show-Jen , Yogev Ram
Published: July 2003

Streptococcus bovis
is an uncommon cause of infection in neonates. However,
S
.
bovis
is capable of causing fulminant neonatal sepsis or meningitis that is indistinguishable clinically from that caused by group B streptococcus.
S
.
bovis
and
S
.
bovis
variant (sometimes referred to as
S
.
bovis
biotypes I and II, respectively) are phenotypically similar but may be differentiated by expanded testing. In adults, specific associations between disease states and different biotypes of
S
.
bovis
are apparent. No data exist on possible differences or clinical relevance of neonatal infection caused by different biotypes or newer species of
S
.
bovis
. We report a 3-day-old neonate with bacteremia and meningitis caused by
S
.
bovis
variant (
S
.
bovis
biotype II/2) and review the literature.
Utilization of 16S Ribosomal DNA Sequencing for Diagnosis of Septicemia Due to
Neisseria elongata
subsp.
glycolytica
in a Neutropenic Patient
Authors: Hombrouck-Alet Cecile , Poilane Isabelle , Janoir-Jouveshomme Claire , Fain Olivier , Cruaud Philippe , Thomas Michel , Collignon Anne
Published: July 2003

Septicemia due to
Neisseria elongata
subsp.
glycolytica
occurs infrequently. We report a case of septicemia in a patient undergoing antimitotic chemotherapy. Gram-negative coccobacilli were isolated from blood cultures. The identity of the isolate by phenotypic methods was uncertain. In contrast, identity was confirmed by 16S ribosomal DNA sequencing, which appeared to be very useful for correct identification.
Shiga Toxin-Producing
Escherichia coli
-Associated Kidney Failure in a 40-Year-Old Patient and Late Diagnosis by Novel Bacteriologic and Toxin Detection Methods
Authors: Teel Louise D. , Steinberg Brett R. , Aronson Naomi E. , O'Brien Alison D.
Published: July 2003

Infection with Shiga toxin-producing
Escherichia coli
(STEC) is the most common cause of kidney failure in children. High morbidity is also associated with infections in the elderly. We describe STEC-associated kidney failure in a 40-year-old patient, including the methods used to identify STEC a month after disease onset.
Bacillus cereusBacteremia in a Preterm Neonate
Authors: Hilliard Nicholaus J. , Schelonka Robert L. , Waites Ken B.
Published: July 2003

Bacillus cereusis an uncommon but potentially serious bacterial pathogen causing infections of the bloodstream, lungs, and central nervous system of preterm neonates. A case of bacteremia caused byB. cereusin a 19-day-old preterm neonate who was successfully treated with vancomycin, tobramycin, meropenem, and clindamycin is described. Implications for the diagnostic laboratory and clinicians whenBacillusspecies are detected in normally sterile sites are discussed, and the small numbers of infant infections proven to be due to this organism that have been described previously are reviewed.
Unusual Presentation of Lemierre's Syndrome Due to
Fusobacterium nucleatum
Authors: Williams Michael D. , Kerber Caroline A. , Tergin Helen F.
Published: July 2003

We report a case of Lemierre's syndrome due to
Fusobacterium nucleatum
in a previously healthy 19-year-old male. This is the first case report of Lemierre's syndrome due to thrombophlebitis of the external jugular vein. The patient had a rapid clinical response to anticoagulation and antibiotics, as supported by anecdotal evidence.
Impossibility of Spin Polarized States for Neutron Star/Proto-Neutron Star Matter in β-Equilibrium Condition
Authors: Ghosh Sutapa , Mandal Soma , Chakrabarty Somenath
Published: July 2003

It is shown explicitly that a ferromagnetic transition of neutron star (NS)/proto-neutron star (PNS) matter in the β-equilibrium condition with σ-ω-ρ exchange type of mean field approximation can actually occur if and only if the neutrinos remain trapped within the system, and perhaps it is also necessary for the neutrinos/anti-neutrinos to carry some finite nonzero mass. It is further shown that the electrons also play a significant role in this transition process. It is therefore, very much unlikely that such a transition of spin polarization can really take place in old neutron stars of very low temperature, whereas, the possibility of spontaneous ferromagnetic transition cannot be ruled out in a newly born PNS.
S-Matrices for Spinor Particles on Reissner–Nordström Black Holes
Authors: Firsova N. E.
Published: July 2003

The scattering problems arising when considering the contribution of the topologically inequivalent configurations of the spinors on Reissner–Nordström black holes to the Hawking radiation is correctly stated. The corresponding S-matrices are described and presented in the form convenient to numerical computations.
Bosonic and Fermionic Behavior in Gravitational Configurations
Authors: Patiño Leonardo , Quevedo Hernando
Published: July 2003

We extend Dirac's approach about the quantization of the electric charge to the case of gravitational configurations. The spacetime curvature is used to define a phase-like object which allows us to extract information about the behavior of the corresponding spacetime. We show that all spacetimes that satisfy certain simple symmetry condition and for which the Petrov type is the same within a specific region, quantization conditions can be derived that impose constraints on the possible values of the parameters entering the respective metrics. As a general result we obtain that for the gravitational configurations described by those metrics, the phase-like object resembles the behavior of bosons and fermions under rotations.
The Dynamical Casimir Effect and Energetic Sources for Gamma Ray Bursts
Authors: Xue She-Sheng
Published: July 2003

On the analogy of the Casimir effect, we present an effect of quantum-field fluctuations, attributed to gravitational field coupling to the zero-point energy of virtual particles in the vacuum. In the process of black hole's formation, such an effect could cause tremendous energy release, possibly describing a scenario of energetic sources for observed gamma ray bursts.
Recent Developments in Rare Kaon Decays
Authors: D'Ambrosio Giancarlo
Published: July 2003

We discuss theoretical issues in rare and radiative kaon decays. The interest is twofold: to extract useful short-distance information and understand the underlying dynamics. We emphasize channels where either we can understand nonperturbative aspects of QCD or there is a chance to test the Standard Model.
HQEFT as a Large Component QCD and Comments on the Incompleteness of HQET
Authors: Wu Y. L. , Yan Y. A. , Zhong M. , Zuo Y. B. , Wang W. Y.
Published: July 2003

The heavy quark effective field theory (HQEFT) is revisited in a more intuitive way. It is shown that HQEFT is a consistent large component QCD of heavy quarks. In the nonrelativistic limit, HQEFT recovers the nonrelativistic QCD (NRQCD). The resulting new effects in the HQEFT of QCD are carefully re-examined. It is then natural to give comments on the usual heavy quark effective theory (HQET). Consistent phenomenological applications of HQEFT exhibit its interesting features and completeness in comparison with HQET. It then becomes manifest why we shall base on the HQEFT of QCD rather than HQET which is incomplete for computing 1/mQcorrections. More precise extraction for ∣Vcb∣ and ∣Vub∣ in the HQEFT of QCD is emphasized.
A Representation of Symmetry Generators for Type IIB Superstring on a Plane Wave in the U(4) Formalism
Authors: Trivedi Gautam
Published: July 2003

We calculate the symmetry currents for type IIB superstring on a maximally supersymmetric plane wave background using the N = (2,2) superconformally covariant U(4) formulation developed by Berkovits, Maldacena and Maoz. An explicit realization of the U(4) generators together with 16 fermionic generators is obtained in terms of the N = (2,2) worldsheet fields. As the action is no longer quadratic, we use a light-cone version to display the currents in terms of the covariant worldsheet variables.
Structural and Magnetic Investigations of Fe2O3-B2O3-CaF2 Glass System
Authors: Ardelean I. , Pǎşcuţǎ P. , Ioncu V.
Published: July 2003

The structural and magnetic properties of a mixed oxide-fluoride vitreous matrix 3B 2 O 3· CaF 2 containing iron ions were investigated. Information concerning the structural units involving iron ions, their valence states and the type of interactions between them were obtained using EPR and magnetic susceptibility measurements.
Structural and Superconducting Properties of RE1 - 2xPrxCaxSr0.8Ba1.2Cu3O7 - δ (RE = Er and Gd) High Tc Superconductors
Authors: Charoenthai N. , Winotai P. , Suryanarayanan R. , Tang I. M.
Published: July 2003

We report here on the structural and superconducting properties of RE 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ (RE = Er and Gd, 0 ≤ x ≤ 0.2) high temperature superconductors. The transition temperature (Tc) of these compounds decreases when the Pr and Ca concentrations are increased. At constant Pr and Ca concentrations, the Tc of Er 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ superconductor system is higher than that observed for the Gd 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ system. For the Gd 0.8 Pr 0.1 Ca 0.1 Sr 0.8 Ba 1.2 Cu 3 O 7 - δ sample, after heating in argon followed by oxygen annealing, the orthorhombicity increases accompanied by 10 K increase in Tc. These results show that though our data indicate an ion-size effect, the Tc suppression rate dTc/dx depends very much on the heat treatment adopted to prepare the samples.
On the Extraction of On-Chip Inductance
Authors: Ismail Yehea I. , Friedman Eby G.
Published: July 2003

Inductance extraction has become an important issue in the design of high speed CMOS circuits. Two characteristics of on-chip inductance are discussed in this paper that can significantly simplify the extraction of on-chip inductance. The first characteristic is that the sensitivity of a signal waveform to errors in the inductance values is low, particularly the propagation delay and the rise time. It is quantitatively shown in this paper that the error in the propagation delay and rise time is below 9.4% and 5.9%, respectively, assuming a 30% relative error in the extracted inductance values. If an RC model is used for the same example, the corresponding errors are 51% and 71%, respectively. The second characteristic is that the magnitude of the on-chip inductance is a slow varying function of the width of a wire and the geometry of the surrounding wires. These two characteristics can be exploited by using simplified techniques that permit approximate and sufficiently accurate values of the on-chip inductance to be determined with high computational efficiency.
Space–Time Block Coding Iterative Multiuser Receiver
Authors: Jiang Hong Rui , Kwak Kyung Sup
Published: July 2003

We present a multiuser receiver for CDMA systems with the combination of turbo channel coding and space–time block coding. A turbo scheme based on multiuser detection, soft interference cancellation and decoding is provided, and the algorithms for space–time decoding and separately interference suppressing are derived in this paper. The multiuser detection consists of multiuser interference suppression and single-user space–time decoding. Then we develop the iterative multiuser receiver based on the soft estimates of the interfering users' symbols. Moreover, simulation is given to verify the effectiveness of the multiuser receiver.
Bus Optimization for Low Power in High-Level Synthesis
Authors: Hong Sungpack , Kim Taewhan
Published: July 2003

Sub-micron feature sizes have resulted in a considerable portion of power to be dissipated on the buses, causing an increased attention on savings for power at the behavioral level and the RT level of design. This paper addresses the problem of minimizing power dissipated in the switching of the buses in the high-level synthesis of data-dominated behavioral descriptions. Unlike the previous approaches in which the minimization of the power consumed in buses has not been considered until operation scheduling is completed, our approach integrates the bus binding problem into scheduling to exploit the impact of scheduling on the reduction of power dissipated on the buses more fully and effectively. We accomplish this by formulating the problem into a flow problem in a network, and devising an efficient algorithm which iteratively finds the maximum flow of minimum cost solutions in the network. Experimental results on a number of benchmark problems show that given resource and global timing constraints our designs are 19.8% power-efficient over the designs produced by a random-move based solution, and 15.5% power-efficient over the designs by a clock-step based optimal solution.
Single DSP Implementation of Realtime 3D Sound Synthesis Algorithm
Authors: Sakamoto Noriaki , Kobayashi Wataru , Onoye Takao , Shirakawa Isao
Published: July 2003

This paper describes a single DSP implementation of a realtime 3D sound synthesis algorithm dedicatedly for mobile applications. This approach is distinctive in that the audible frequency band is divided into three subbands in such a way that, given a head-related transfer function (HRTF), the portion of the functional behavior in each subband can be realized efficiently by a distinct digital filtering structure. The whole digital filters are implemented on a commercially available 16-bit fixed-point DSP, taking account of three major design factors of memory size, calculation accuracy, and computational complexity. As a result, the realtime 3D sound synthesis is achieved by employing a single DSP with the low computational labor of 51.3 MIPS and the small memory space of 4.6 k words.
Residue Checker with Signed-Digit Arithmetic for Error Detection of Arithmetic Circuits
Authors: Wei Shugang , Shimizu Kensuke
Published: July 2003

This paper presents a fast residue checker for the error detection of arithmetic circuits. The residue checker consists of a number of residue arithmetic circuits such as adders, multipliers and binary-to-residue converters based on radix-two signed-digit (SD) number arithmetic. The proposed modulo m (m = 2p ± 1) adder is designed with a p-digit SD adder, so that the modulo m addition time is independent of the word length of operands. The modulo m multiplier and binary-to-residue number converter are constructed with a binary tree structure of the modulo m SD adders. Thus, the modulo m multiplication is performed in a time proportional to log 2 p and an n-bit binary number is converted into a p-digit SD residue number, n ≫ p, in a time proportional to log 2(n/p). By using the presented residue arithmetic circuits, the error detection can be performed in real-time for a large product-sum circuit.
A Methodology for Calculating the Undetectable Double-Faults in Self-Checking Circuits
Authors: Nikolaidis S. , Karaolis E. , Kakarountas A. , Papadomanolakis K. , Goutis C. E.
Published: July 2003

In this paper, a methodology for the calculation of the undetectable double-faults in self-checking circuits with bit-sliced architecture is introduced. This methodology is based on a systematic exploration of the combinations of nodes where undetectable double-faults can arise. The self-checking n-bit 2-to-1 multiplexer coded by parity is used as a test vehicle for the presentation of the methodology and the number of the undetectable double-faults is given in a parametric way. The proposed methodology can easily be applied to other bit-sliced circuits. Common self-checking circuits are implemented for different coding schemes and are using standard cell technology to verify the proposed methodology. The effectiveness of these implementations in fault detection as well as their requirements in hardware and power are also investigated.
Combined Huffman Code and Generalized Array Codes Employing Phase/Frequency Modulation
Authors: Soyjaudah K. M. S. , Hosany M. A.
Published: July 2003

The authors present a simple technique to combine source coding, channel coding and modulation. This technique employs the Huffman code for source coding, Generalized Array Codes (GAC) for channel coding and Phase/Frequency (BFSK/MPSK) for modulation. The combined scheme has the advantage of reducing the redundancy, providing error protection and simultaneously optimizing on channel bandwidth. It is shown the combined system gives the same performance as its separate counterparts but has lower complexity. The algorithm used to construct the combined trellis decoder employing phase/frequency for a given source text file is designed and implemented in software. The error performances for the combined schemes using BFSK/MPSK modulation are compared with those employing coded as well as Uncoded MPSK modulation. Such a Block Coded Modulation (BCM) scheme is suitable for both information storage and digital transmission systems.
A Fast QRNS-Based Algorithm for the DCT and Its Field-Programmable Logic Implementation
Authors: Ramírez Javier , García Antonio
Published: July 2003

This paper assesses the arithmetic benefits provided by the Residue Number System (RNS) for building Digital Signal Processing (DSP) systems with Field-Programmable Logic (FPL) technology. The quantifiable benefits of this approach are studied in the context of a new Fast Cosine Transform (FCT) architecture enhanced by using the Quadratic Residue Number System (QRNS). The system reduces the number of adders and multipliers required for the N-point Discrete Cosine Transform (DCT) and provides high throughput. For an FPL-based implementation, the proposed design gets significant improvements over an equivalent 2C structure. By using up to 6-bit moduli, an overall increase in the system performance of about 140% is achieved. If this speed increase is considered along with the penalty in device resources, the presented QRNS-based FCT system provides an improvement in the area-delay figure factor of about 20%. Finally, the conversion overhead was carefully studied and it was found that the quantifiable benefits of the proposed design are not affected when converters are included.
Knots with Braid Index Three Have Property-P
Authors: Menasco W. , Zhang X.
Published: July 2003

We prove that knots with braid index three in the 3-sphere satisfy the Property P conjecture.
Markov Moves Cannot be Replaced by Double Markov Moves
Authors: Fiedler T.
Published: July 2003

We show that Markov moves cannot be replaced by double Markov moves.
Surface Structure and Growth Mode of Pd Deposited on Mo(110) Surface
Authors: Maehara Y. , Kawanowa H. , Gotoh Y.
Published: July 2003

The surface structure and growth mode of Pd/Mo(110) have been studied using reflection high energy electron diffraction (RHEED). The surface diagram of Pd on the Mo(110) substrate for deposition thickness versus substrate temperature was obtained. Four kinds of surface structures, namely α1, α2, β and γ, were observed. At less than 1 ML, α2 appeared in temperatures ranging from 400 to 1050°C and α1 appeared from RT to 400°C. α2 has a structure intermediate between those of Pd(111) and Mo(110), in which the dense direction of the layer is parallel to the [111]Mo orientation and their atomic row distances are coincident, resulting in formation of a long-period structure with a Mo surface, namely a coincident site lattice. The α1 structure is similar to the 1 × 1 structure. At more than 1.0 ML, β and γ structures appeared simultaneously in the temperature region from 500 to 950°C. However, at a high temperature region from 950 to 1050°C, the α2 structure was observed. β shows a one-dimensional ordered structure, in which Pd atoms line along [111]Mo. γ exhibits a 3 × 1 structure with the same atomic arrangement as the Mo(110) plane rotated at 70.5°. At greater than 2.0 ML, the Pd film grows in the Frank–van der Merwe growth mode at a low temperature with accumulation of a Pd(111) layer, and in the Stranski–Krastanov growth mode at a high temperature with two-dimensional growth of the γ structure followed by formation of flat crystallites.
Excited Surface Band Structures and Surface Barrier Features in VLEED
Authors: Read M. N.
Published: July 2003

We have tested a surface barrier model for Cu(001) for consistency with below vacuum level data from inverse photoemission and above vacuum level data from very low energy electron diffraction (VLEED). The model has an exponential-type saturation which extends to the center of the first row of atoms in the crystal. The barrier model can account for the limited data available for the surface barrier band structure below the vacuum level but not for the strong surface barrier features which occur in VLEED reflectivity spectra for θ = 80° and ϕ = 45°. This is the case even when allowance is made for dynamical variation of the key barrier structural features. It is concluded that this form of the barrier saturation is not correct for real crystals.
Structural Symmetry and Optical Properties of Dielectric Multilayers
Authors: Peng R. W. , Huang X. Q. , Qiu F. , Liu Y. M. , Hu A. , Jiang S. S.
Published: July 2003

We have investigated the structural symmetry and optical properties of the dielectric multilayers. By using the transfer-matrix method, the propagation of electromagnetic wave in the dielectric multilayer film is obtained. It is shown that if a mirror symmetry is induced to the structure, perfect transmissions will definitely happen. And the perfect transmission can be controlled at certain wavelengths if the special structure with symmetry is achieved. Experimental observations are in good agreement with the theoretical predictions. This finding will have potential applications to optoelectric devices, such as the wavelength division multiplexing (WDM) system.
Decohesion of Σ3(111) Grain Boundary in Tungsten with Boron Interstitial
Authors: Mundim Kleber , Dorfman Simon , Fuks David
Published: July 2003

We present the results of atomistic simulations of the decohesion process of the Σ3(111) GB with boron additives. On the basis of the generalized simulated annealing formalism we demonstrate that accounting for angle-dependent three-body interactions leads to the formation of a minimum in the energy profile in the decohesion process and to the enhancement of the boron-induced interatomic interaction across the GB. Our study of the detailed atomic configuration of the GB predicts the effect of the "grain boundary separation" that is induced by the interstitial impurity. The interatomic potentials used in these simulations were obtained from ab initio total energy calculations on the basis of a recursion procedure.
Structural and Electronic Properties of a Thin Metal-Silicide Film on Silicon Surface: A First-Principles Study
Authors: Kang Byung Sub , Kang Hee Jae , Oh Suhk Kun
Published: July 2003

The structural stability of metal (M) silicide (M = Co, Ni) phases and magnetic properties for the deposited one and two monolayers (ML) of M on the Si(001) surface was studied by the use of the ab initio full-potential linear muffin-tin orbital (FP-LMTO) method. The diffusion of M atoms on Si into the tetrahedral (fourfold M) sites was found to be energetically favorable. The deposited M atoms easily migrate into the bulk because the diffusion or interchange is energetically more favorable than the formation of cluster in a surface layer. The energetics for the structural stability of the "fourfold Si surface" model was compared with that of the sixfold structural model. Our results for the electronic properties of the MSi2/Si(001) surface and interface were compared with experimental and other theoretical results.
Bulk Homogeneous Uniaxial Stress Arising from Surface Damage of Crystalline Silicon and Germanium
Authors: Fisher P. , Vickers R. E. M. , Lau D. C.
Published: July 2003

Abrasion of two opposing surfaces of either crystalline Si or Ge produces a compressive, homogeneous, uniaxial stress extending throughout the bulk perpendicular to the surfaces. This is concluded by analyzing the splittings, intensities, and polarizations of the sharp Lyman absorption lines of bulk shallow impurities in the abraded materials. This effect so far has been observed for samples of thickness, t, from 0.4 to 5 mm for Si ground with water slurries of SiC or alumina with optical faces coplanar with {100} and {111} planes while {100}, {110}, {111}, and {112} planes of Ge have been abraded with SiC in water and examined over the range 0.8 ≤ t ≤ 3.0 mm. For both materials, the internal stress is found to be inversely proportional to t. Controlled etching indicates the damaged layers producing the bulk stress to be < 0.5 μm thick.
Development of a Novel Instrument for X-Ray Photoelectron Diffraction and Holography
Authors: Ishii Hideshi , Shiraki Susumu , Tamura Keiji , Chu Wei-Guo , Owari Masanori , Shimizu Ryuichi , Nihei Yoshimasa
Published: July 2003

For X-ray photoelectron diffraction (XPED) and holography measurements we developed a novel laboratory instrument with the multienergy high power X-ray source and the high energy and high angular resolution photoelectron spectrometer system. The photon intensities of Al–Kα, Cr–Lα and Cu–Kα were estimated at 4.6 × 1011 cps, 7.5 × 1010 cps and 7.2 × 1010 cps, respectively. Ag3d XPS also revealed that the energy resolutions of Al–Kα and Cr–Lα sources were 0.9 eV and 3.1 eV, respectively. XPS and XPED of h-BN/Ni(111) excited by Al–Kα and Cr–Lα elucidated the potential and the validity of the XPED and holography analysis by using this novel instrument. Cu–Kα excitation XPS and Ti1s XPED measurements of the SrTiO3 (001) surface have also been performed.
Intra-Subnet Load Balancing in Distributed Workflow Management Systems
Authors: Bauer Thomas , Reichert Manfred , Dadam Peter
Published: July 2003

For enterprise-wide and cross-organizational process-oriented applications, the execution of workflows (WF) may generate a very high load. This load may affect WF servers as well as the underlying communication network. To improve system scalability, several approaches for distributed WF management have been proposed in the literature. They have in common that different partitions of a WF instance graph may be controlled by different WF servers from different subnets. The control over a particular WF instance, therefore, may be transferred from one WF server to another during run-time if this helps to reduce the overall communication load. Thus far, such distributed approaches assume that exactly one WF server resides in each subnet. A single server per subnet, however, may become overloaded. In this paper, we present and verify a novel approach for replicating WF servers in a distributed workflow management system. It enables an arbitrary and changeable distribution of the load to the WF servers of the same subnet, without requiring additional communication.
Universal Data Warehousing Based on a Meta-Data Modeling Approach
Authors: Fong Joseph , Li Qing , Huang Shi-Ming
Published: July 2003

Data warehouse contains vast amount of data to support complex queries of various Decision Support Systems (DSSs). It needs to store materialized views of data, which must be available consistently and instantaneously. Using a frame metadata model, this paper presents an architecture of a universal data warehousing with different data models. The frame metadata model represents the metadata of a data warehouse, which structures an application domain into classes, and integrates schemas of heterogeneous databases by capturing their semantics. A star schema is derived from user requirements based on the integrated schema, catalogued in the metadata, which stores the schema of relational database (RDB) and object-oriented database (OODB). Data materialization between RDB and OODB is achieved by unloading source database into sequential file and reloading into target database, through which an object relational view can be defined so as to allow the users to obtain the same warehouse view in different data models simultaneously. We describe our procedures of building the relational view of star schema by multidimensional SQL query, and the object oriented view of the data warehouse by Online Analytical Processing (OLAP) through method call, derived from the integrated schema. To validate our work, an application prototype system has been developed in a product sales data warehousing domain based on this approach.
The Case Handling Case
Authors: Reijers H. A. , Rigter J. H. M. , van der Aalst W. M. P.
Published: July 2003

On the Dutch workflow market, a new and interesting paradigm named "case handling" is emerging. The goal of case handling is to overcome the limitations of existing workflow management systems. By using a data-driven approach combined with implicit routing and carefully avoiding context tunneling, awareness and flexibility are improved. Currently, many organizations are considering case handling systems such as FLOWer (Pallas Athena) rather than the more traditional workflow management systems. This paper provides a critical assessment of this development. The goal is to show the pro's and con's of case handling. Moreover, based on this assessment, an alternative approach using slightly extended workflow management systems is proposed. This approach is being pursued by the Dutch government in a project involving the workflow management system Staffware. Based on our experiences thus far, we provide guidelines for selecting the proper technology.
Semantic Similarity of an Object as a Function of the Context (SSOFC) in a Heterogeneous Environment
Authors: Jameson Mbale , Fei Xu Xiao , Chun Deng Sheng
Published: July 2003

The relationship of Semantic Similarity of an Object as a Function of the Context (SSOFC) being the key factor in data integration is investigated. The SSOFC is a context-based system, which exploits the context of an object by utilizing the semantic similarity involved, in order to reconcile bottleneck conflicts (semantic) standing in the way of interoperability acquisition in heterogeneous systems. SSOFC is further re-enforced with the agents to equip architectural intelligence and facilitate the cooperative tasks, such as the versatility to pass, share, communicate, liaise, and negotiate the information among the architectural components in a human way. The SSOFC operates in semantic and schematic spaces that are linked with a projection facilitated by cooperative agents. In the Semantic Space, the semantic proximity (semPro) through its first component context captures the real world semantics from the local heterogeneous sources. Meanwhile, in Structural Space, the schema correspondences are paramount in order to capture structural similarities in an algebraic or mathematical formalism for reasoning and manipulation on the computer.
ChemSafe (HK) Ltd
Authors: Tsai Terence , Lee Jonathan , Siu Catina Pui Pui , Ma Michael Chun-Fu , Lam Christianne , Li Meg Sze Ming
Published: July 2003

This case study explores the unique challenges confronting a small-sized Hong Kong enterprise in the wake of the "Green Revolution". The founder Mr. Peter Chan, possessed of a zest to protect the natural environment, sought to combine profit for the company with environmental protection. The science and technology behind the development of PestControl®, an organic and environmentally friendly pesticide, was clearly superior to that of its closest competition. However, despite an impressive growth rate in the 1990s, Chan was concerned about his firm's ability to sustain growth. The case is a classic example of entrepreneurship fighting for survival in a rapidly changing society.
Revenue Management at Prego Italian Restaurant
Authors: Kimes Sheryl E. , Wirtz Jochen
Published: July 2003

After the busy lunch hours on a weekday afternoon, John, Prego's restaurant manager, was looking at the half-empty restaurant. He felt that it was in total contrast to the lunch and dinner hours, especially during the weekends, when they had to turn away customers. If seats were occupied during the off-peak hours, more revenue could be generated. During the peak periods, when customer demand exceeded the supply of tables and diners were unwilling to wait for long, Prego was losing revenue and, perhaps, even future business. John thought that there should be better strategies in which the revenue could be increased. John hired a consultant to help develop a revenue management strategy that would increase revenues without jeopardizing diner satisfaction. The case deals with the typical challenges in demand and supply in capacity management in the restaurant business and services management.
Competing or Complementing: AES Entry into the Chinese Power Generation Market
Authors: Croft Lena
Published: July 2003

This case study used longitudinal data to test the applicability of a western theory to a socialist market economy. Traditional theories assert that on entering a foreign market, firms must possess some ownership-specific advantages (e.g. access to sources of finance and advanced technology) in order to compete with indigenous firms (Hymer, 1976; Dunning, 1985; Buckley and Casson, 1991). The theories were subjected to debate when applied to the entry of the AES Corporation (AES), a United States power generation firm, into the People's Republic of China where socialist economic system is in practice. The case method was used to collect information rich qualitative data so as to analyse the firm behaviour of AES in China when the firm was exposed to the context of different fundamental values and institutional orders. Secondary data was collected from archives. In-depth interviews were conducted to gather data for later analysis.

The study concluded that access to finance was the major ownership advantage constituting the successful entry of AES into China. This advantage complemented the deficiencies of its Chinese partners. Yet, the complementary relationship may not extend to some quasi state-owned firms which are nurtured under the Chinese government policies to become the "National champion teams". With the emergence of the "National champion teams", AES would have to apply a new set of strategies to meet the challenge.
NoKalb Genetics (Pakistan) Limited: Supply Chain Management
Authors: Iqbal Rana Arif
Published: July 2003

This case is about the Supply Chain of a pesticides producer (disguised as a hybrid seeds producer) that imported the raw material for its pesticides from its mother company in Switzerland, formulated and packed it in Karachi, and sold it throughout Pakistan. The company had two large warehouses in the country, many regional ware-houses, and a chain of retail outlets throughout the country. The company had been steadily losing market share to cheaper "generics" in the last 15 years. The company had also changed hands a few times in the last ten years and had been under pressure to reduce working capital requirements. The case looks at the typical challenges in supply chain management.
Sales Compensation at Nirala
Authors: Khan Wasif M.
Published: July 2003

In 2000, Faisal Farooq, the young head of Nirala Sweets wanted to design a new reward system for his salesforce, as part of his effort to professionalise the firm. Nirala Sweets, a 52 year-old firm, founded by Faisal's grandfather was the leading purveyor of traditional sweetmeats in Lahore, Pakistan. The national culturn, the informal manner in which the firm had been run, weak management information systems, and the behavioural complexity of his growing firm are some of the challenges he faced. He needed to think carefully about how these would impact the design and implementation of an effective salesforce reward system.
Effectiveness of Hedging Strategies under Model Misspecification and Trading Restrictions
Authors: Mahayni Antje
Published: July 2003

The following paper focuses on the incompleteness arising from model misspecification combined with trading restrictions. While asset price dynamics are assumed to be continuous time processes, the hedging of contingent claims occurs in discrete time. The trading strategies under consideration are understood to be self-financing with respect to an assumed model which may deviate from the "true" model, thus associating duplication costs with respect to a contingent claim to be hedged. Based on the robustness result of Gaussian hedging strategies, which states that a superhedge is achieved for convex payoff-functions if the "true" asset price volatility is dominated by the assumed one, the error of time discretising these strategies is analysed. It turns out that the time discretisation of Gaussian hedges gives rise to a duplication bias caused by asset price trends, which can be avoided by discretising the hedging model instead of discretising the hedging strategies. Additionally it is shown, that on the one hand binomial strategies incorporate similar robustness features as Gaussian hedges. On the other hand, the distribution of the cost process associated with the binomial hedge coincides, in the limit, with the distribution of the cost process associated with the Gaussian hedge. Together, the last results yield a strong argument in favour of discretising the hedge model instead of time-discretising the strategies.
A Quantum Field Theory Term Structure Model Applied to Hedging
Authors: Baaquie Belal E. , Srikant Marakani , Warachka Mitch C.
Published: July 2003

A quantum field theory generalization, Baaquie [1], of the Heath, Jarrow and Morton (HJM) [10] term structure model parsimoniously describes the evolution of imperfectly correlated forward rates. Field theory also offers powerful computational tools to compute path integrals which naturally arise from all forward rate models. Specifically, incorporating field theory into the term structure facilitates hedge parameters that reduce to their finite factor HJM counterparts under special correlation structures. Although investors are unable to perfectly hedge against an infinite number of term structure perturbations in a field theory model, empirical evidence using market data reveals the effectiveness of a low dimensional hedge portfolio.