bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of capsaicin on blood glucose, plasma insulin levels and insulin binding in dog models
Authors: Tolan I. , Ragoobirsingh D. , Morrison E. Y. St. A.
Published: August 2002

Capsicum frutescens has been used to treat diabetes mellitus by traditional healers in Jamaica. This study was designed to identify any hypoglycaemic principle(s) and to determine the mechanism of action. Purification experiments employing thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) led to the extraction of the active principle, capsaicin. Capsaicin caused a decrease in blood glucose levels of 4.91 ± 0.52 (n = 6) mmol/dL versus 6.40 ± 0.13 mmol/dL (n = 6) for the control (p < 0.05) at the 2.5 h time interval when the oral glucose tolerance test (OGTT) was performed on dogs treated with capsaicin and compared with the control. Plasma insulin levels measured at the 2.5 h time interval showed that there was an increase in plasma insulin levels of 5.78 ± 0.76 µIU/mL (n = 6) for the capsaicin treated dogs versus 3.70 ± 0.43 µIU/mL (n = 10) for the control (p < 0.05). Insulin receptor studies, using a modification of the method of Gambhir et al. done on monocytes obtained from blood at the 2.5 h time interval showed that there was a decrease in the percentage receptor binding for the capsaicin treated dogs when compared with the control. Insulin affinity results showed that there was a decrease of 2.4 × 10−4 in monocytes for the capsaicin treated dogs versus 8.77 × 10−4 for the control (p < 0.05). Also, insulin receptor calculations showed a decrease in number, 2.63 × 108 ± 5.73 × 107, compared with 8.77 × 108 ± 1.47 × 108 for the control. In conclusion it can be stated that capsaicin is responsible for the hypoglycaemic episodes seen in the dogs and that it also causes an increase in insulin secretion which leads to a reduction of insulin binding on the insulin receptors. Copyright © 2001 John Wiley & Sons, Ltd.
Antimicrobial activity of seed extracts and bondenolide from Caesalpinia bonduc (L.) Roxb.
Authors: Simin K. , Khaliq‐uz‐Zaman S. M. , Ahmad V. U.
Published: August 2002

The antibacterial and antifungal activities, along with a phytotoxicity test of the newly isolated diterpene bondenolide (1), of a methanol extract, ethylacetate fraction and water soluble part of the methanol extract of Caesalpinia bonduc (L.) Roxb. were assayed. Copyright © 2001 John Wiley & Sons, Ltd.
LDH profiles of male and female rats treated with Vepacide
Authors: Rahman M. F. , Siddiqui M. K. J. , Jamil Kaiser
Published: August 2002

In the present study we investigated the effect of vepacide, a neem‐based compound, on the biochemical target enzyme lactate dehydrogenase (LDH) in different tissues of male and female albino Wistar rats treated orally with 80, 160 and 320 mg/kg (low, medium and high doses, respectively) for a period of 90 days. Prolonged administration of vepacide caused a significant increase of LDH activity in serum and lung tissues and a decrease in liver and kidney in both male and female rats when measured after 45 and 90 days of daily treatment. Females were more susceptible than males with regard to serum and kidney LDH showing sexual dimorphism in the treated rats. Recovery was observed in the affected enzyme after 28 days post treatment (withdrawal study). A positive correlation was observed with regard to this enzyme between serum and lung tissues, whereas for serum versus liver and kidney there was a negative correlation. The effect of vepacide was more pronounced in the lung tissue followed by liver and kidney tissues. Necrosis of the liver and kidney tissues was observed but in the lung tissue an increase in the LDH enzyme was seen. Therefore, it was concluded that the increase in LDH could be indicative of a stress adaptive response to the toxicant. Copyright © 2002 John Wiley & Sons, Ltd.
The antiulcer activity of Garcinia cambogia extract against indomethacin‐induced gastric ulcer in rats
Authors: Mahendran P. , Vanisree A. J. , Shyamala Devi C. S.
Published: August 2002

Garcinia cambogia extract is a herbal preparation that has been suggested as useful in the treatment of gastrointestinal disorders. In the present study this drug was tested for its antiulcerogenic effect. Oral pretreatment with Garcinia cambogia fruit extract (1 g/kg body wt/day) for 5, 10 or 15 days protected the gastric mucosa against the damage induced by indomethacin (20 mg/kg body wt). The volume and acidity of the gastric juice decreased in the pretreated rats. The glycoprotein levels of the gastric contents which were decreased in the untreated rats, maintained near normal levels in the pretreated rats. Protein which was elevated in the gastric juice of untreated rats, showed near normal levels in the pretreated rats. Garcinia cambogia was able to decrease the acidity and to increase the mucosal defence in the gastric areas, thereby justifying its use as an antiulcerogenic agent. Copyright © 2002 John Wiley & Sons, Ltd.
ISO 9002 certification – expectations of the sponsor's auditor
Authors: Widler Beat
Published: August 2002

The value of ISO standards or rather the reliability of their application by clinical laboratories and CROs must be questioned. Results from audits performed by auditors overseeing ISO certification and maintenance do not necessarily provide full confidence in the ISO certification process to sponsors. Based on our sponsor‐audits, we concluded that an ISO certification cannot substitute a systems' audit conducted by our own auditors against GCP and, where appropriate, GLP standards. Copyright © 2002 John Wiley & Sons, Ltd.
GLPs and medical devices
Authors: Lynn Linda Palagi
Published: August 2002

Applying Good Laboratory Practice (GLP) regulations to studies of medical devices and combination products (drug/device products) presents some unique challenges. The complexity of medical devices – which may be internal, external, or composed of many intricate parts including software, hardware, or drugs to perform their intended task – requires interpretation of the regulations. Further, the dynamics of the conduct of non‐clinical laboratory studies for medical devices can be quite complex often involving a team of scientists, engineers, computer specialists, technicians, veterinarians, physicians, pathologists and equipment from both the test facility and sponsor. This article highlights areas of the GLP regulations and provides information and suggestions for GLP compliance for medical device studies. Copyright © 2002 John Wiley & Sons, Ltd.
Dynamics of primary charge separation in bacterial photosynthesis using the multilevel Redfield–Davies secular approach
Authors: Sadygov Rovshan G. , Neuhauser Daniel
Published: August 2002

We use Redfield's relaxation theory in the Davies formulation to study primary charge separation reactions in bacterial photosynthesis. The specific model studied is the standard one (spin‐boson), with three states for the system, harmonic oscillators for the bath, and linear ohmic system–bath coupling. The Redfield–Davies formulation, which is equivalent to the secular approximation, is Markovian, of second order in system–bath coupling, and is written for the system's density matrix. The approximation does not suffer from any negative probabilities (which appear in the original Redfield approach) and can therefore be used for long‐time processes (20 ps or more here). Our results are in line with previous studies, especially to high bath frequencies. They confirm the usefulness of the Redfield–Davies secular approach as a convenient and simple tool for studying system–bath processes. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Mechanism of action of zinc proteinases: A MNDO/d/H study of alternative general‐acid general‐base catalytic pathways for carboxypeptidase‐A
Authors: Kilshtain‐Vardi Alexandra , Shoham Gil , Goldblum Amiram
Published: August 2002

Two alternative pathways for peptide cleavage by water, both of the general‐acid general‐base type, have been followed by semiempirical theoretical calculations on a model of the active site. The system of 120 atoms has been carved out of high resolution X‐ray coordinates of a carboxypeptidase A (CPA) complex with a ketomethylene inhibitor, pyroglutamic‐N‐Phe‐(CH2CO)‐Phe‐OH. The method employed was a combination of MNDO/d and MNDO/H which, together, enable one to deal with the effect of zinc and of multiple hydrogen bond interactions, respectively. The first step in both pathways is nucleophilic attack by a hydroxide on the peptide carbonyl, and the second is proton transfer to the nitrogen of the peptide. This second step presents the highest energy barrier for the reaction. Peptide bond cleavage is spontaneous subsequent to proton transfer. The two alternative paths differ little in barrier heights, but the thermodynamic enthalpy difference for the path of one mechanism is some 20 kcal/mol more stable than for the other. The first mechanism is the one proposed by Lipscomb (Acc Chem Res 1989, 22, 62–69) and the second, less stabilizing mechanism was proposed by Mock (J Biol Chem 1991, 266, 6369–6400). Under kinetic control, both reactions are feasible, and new experiments should be designed in order to clarify if only one of the two is operating under most of the relevant conditions. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 88: 87–98, 2002
Why does 5‐methylchrysene interact with DNA as both a planar and a nonplanar polycyclic aromatic hydrocarbon? Quantum mechanical studies
Authors: Rabinowitz James , Little Stephen , Brown Katrina
Published: August 2002

Polycyclic aromatic hydrocarbons are a large class of anthropogenic chemicals found in the environment. Some class members are potent animal carcinogens while other similar class members show little carcinogenic activity. When considering a series of in vitro studies of the interaction of polycyclic aromatic hydrocarbon bay region diol‐epoxides with deoxyribonucleic acid (DNA), it was found that molecules with a crowded bay region behaved differently than molecules with a more open bay region. Molecules with a crowded bay region are nonplanar while in general polycyclic aromatic hydrocarbons are planar molecules. This dichotomy between planar and nonplanar subclasses proved useful, but when the experimental data was considered, 5‐methylchrysene did not fit well into either class. In this study quantum mechanical calculations are reported that show 5‐methyl chrysene and its diol‐epoxides are nonplanar molecules, but the energy required to force them to be planar is considerably smaller than for most other nonplanar polycyclic aromatic hydrocarbons. The relationship to the experimental results that indicated 5‐methylchrysene may behave like both a planar polycyclic aromatic hydrocarbon in some experiments and a nonplanar polycyclic aromatic hydrocarbon in others is discussed. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Photoabsorption processes in nitrous oxide and formaldehyde
Authors: Martín I. , Velasco A. M. , Lavín C. , Olalla E. , Bustos E.
Published: August 2002

Absorption oscillator strengths and photoionization cross sections for electronic transitions involving Rydberg states that are relevant to the photochemistry of N2O and H2CO are reported. These compounds have been found to play an important role in the evolution of Earth's upper atmosphere. However, the difficulties encoutered in both laboratory measurements and theoretical calculations on the photoabsorption of these compounds are responsible for the scarcity of data in the literature. The present calculations have been performed with the molecular‐adapted quantum defect orbital (MQDO) method, of which the adequacy for this type of studies has recently been assessed. A comparative analysis of the photoabsorption intensities in the molecules and their constituting atoms has enabled us to predict the variation of the extent of atomic character of the molecular Rydberg orbitals with the degree of excitation. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Rapid and sensitive quantitation of antibiotics in fermentations by electrospray mass spectrometry
Authors: Morgan Janine , Joyce‐Menekse Miranda E. , Rowlands Robert T. , Gilbert Ian H. , Lloyd David
Published: August 2002

Electrospray ionisation mass spectrometry (ESI‐MS) has been used for the determination and quantitation of a broad range of 24 antibiotics, from groups including aminoglycosides, β‐lactams, tetracyclines, antifungals and glycopeptides. Spectra have been acquired for all 24 antibiotics derived from pure samples dissolved in acetonitrile/water, along with samples extracted from complex fermentation liquor. Quantitation was carried out by the detection of the protonated molecules, using time‐scheduled single‐ion monitoring (SIM). ESI‐MS was used to detect and quantify to 5‐µM levels. A one‐step extraction of antibiotics with an organic solvent (methanol) was used for this rapid and simple procedure. Specificity is not matched by other methods and antibiotic analogues (e.g. the five forms of erythromycin) can be determined within minutes. Copyright © 2001 John Wiley & Sons, Ltd.
Characterisation of anthocyanidins by electrospray ionisation and collision‐induced dissociation tandem mass spectrometry
Authors: Oliveira M. C. , Esperança P. , Almoster Ferreira M. A.
Published: August 2002

The present study describes the use of electrospray ionisation mass spectrometry, in combination with collision‐induced dissociation (CID) and tandem mass spectrometry, for the structural characterisation of anthocyanidins and their O‐glycosides. The high‐energy CID spectra of [M−Cl]+ ions of the free aglycones show characteristic fragmentation pathways, which provide useful information about the substitution pattern in the A‐ and B‐rings of each compound. The major fragmentation observed in the high‐energy CID spectra of [M−Cl]+ ions of anthocyanins involves loss of the mono‐ or disaccharide units resulting in ions containing only the aglycone moiety. From the spectral data, the identity of the aglycone can be established as well as the number and the class of monosaccharide units in the O‐glycosides. Copyright © 2001 John Wiley & Sons, Ltd.
Automatic function switching and its usefulness in peptide and protein analysis using direct infusion microspray quadrupole time‐of‐flight mass spectrometry
Authors: Hoyes Emmy , Gaskell Simon J.
Published: August 2002

Automatic function switching has been investigated for high‐throughput protein identification and sequencing of peptides using direct infusion of tryptic digests on a quadrupole time‐of‐flight instrument. The increase in speed and the high quality of data make it a favourable technique for tandem mass spectrometry when compared to manual selection of each precursor ion; these advantages are not restricted to combined LC/MS/MS analyses for which the automatic function‐switching mode was originally developed. This mode was compared to analyses performed using a slow scan of the quadrupole analyzer with repeated recording of product ion spectra. For the specific purpose of generating product ion data for sequence determination (as opposed to surveying all precursors of a selected product ion), the automatic function‐switching mode was, as expected, markedly superior with respect to speed of analysis and quality of data. Furthermore, the automatic function‐switching mode provides greater versatility with respect to selection of optimal collision energies. Copyright © 2001 John Wiley & Sons, Ltd.
Study of excretion of ecdysterone in human urine
Authors: Tsitsimpikou Christina , Tsamis George D. , Siskos Panayotis A. , Spyridaki Maria‐Helen E. , Georgakopoulos Costas G.
Published: August 2002

A study of excretion in human urine of ecdysterone, which is the active component of several over‐the‐counter supplements such as ‘Ecdysten’, reportedly used by athletes, is presented. The study was performed after oral administration of 20 mg of ecdysterone. The collected urine samples were prepared using the standard screening extraction procedure for the free and conjugated fraction of anabolic steroids, and analyzed by gas chromatography (GC) coupled with quadrupole mass spectrometry (MS) and also with high‐resolution mass spectrometry (HRMS). Two ecdysterone metabolites were identified and detected along with unchanged ecdysterone. Accurate mass measurements were made for diagnostic ions, including the molecular ion of the main metabolite of ecdysterone, deoxyecdysone, which, to our knowledge, has not previously been reported in the literature. These accurate mass measurements support the proposed fragmentation scheme. Copyright © 2001 John Wiley & Sons, Ltd.
Detection of specific Bacillus anthracis spore biomarkers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Elhanany Eytan , Barak Ruth , Fisher Morly , Kobiler David , Altboum Zeev
Published: August 2002

Analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) was applied for the characterization of Bacillus anthracis spore biomarkers. B. anthracis spores were extracted under a simple procedure, followed by linear mode analysis, using sinapinic acid as the matrix. Several markers with a mass range of 4–7 kDa were detected in three B. anthracis strains: Vollum, Sterne and V770‐NP1‐R. Similar spectra were also obtained for spore extracts of two members of the B. cereus group: B. thuringiensis and B. cereus, but not for B. mycoides, B. subtilis or B. licheniformis, suggesting that these markers are specific to closely related members of the B. cereus group. When α‐cyano‐4‐hydroxycinnamic acid was used as the matrix, at least four additional new markers within a mass range of 2–4 kDa could be detected in all B. anthracis spore extracts. These markers, corresponding to a molecular weight of 2528.3, 2792.4, 3077.4, and 3590.7 Da, have not been observed in extracts of the three closely related Bacillus species – B. cereus, B. thuringiensis and B. mycoides. These unique B. anthracis biomarkers, which were isotopically resolved and reproducibly detected in the highly accurate MALDI‐TOFMS reflectron mode, may be useful as a basis for rapid and specific identification of B. anthracis strains. Copyright © 2001 John Wiley & Sons, Ltd.
Combined quantum chemical and RRKM modeling of the main fragmentation pathways of protonated GGG. I. Cis‐trans isomerization around protonated amide bonds
Authors: Paizs Béla , Suhai Sándor
Published: August 2002

Detailed analysis of the possible fragmentation channels of protonated GGG suggests that a pre‐dissociation cis‐trans isomerization of the N‐terminal amide bond has to take place when y1 ions are formed on the ‘diketopiperazine’ pathway. Quantum chemical calculations were performed in order to determine the effect of different isomerization states (trans‐trans, cis‐trans, trans‐cis, and cis‐cis) on the energetics of protonation of GGG at the most important protonation sites including the terminal amino group and amide oxygen and nitrogen atoms. These calculations indicate that cis‐trans isomerization is energetically feasible for protonated GGG and the relative energy of the most stable such species that contain a cis amide bond is at a few kcal/mol calculated with respect to the trans‐trans global minimum. Analysis of the possible pathways for the cis‐trans isomerization suggests that this process involves species protonated at the nitrogen of the N‐terminal amide bond. Detailed discussion of the fate of such species indicates that cis‐trans isomerization of the N‐terminal amide bond of protonated GGG is kinetically controlled while a low‐energy pathway connecting the most stable trans‐trans and cis‐trans species no doubt exists. Copyright © 2001 John Wiley & Sons, Ltd.
In vitro metabolite identification using fast gradient high performance liquid chromatography combined with tandem mass spectrometry
Authors: Hop Cornelis E. C. A. , Tiller Phillip R. , Romanyshyn Leslie
Published: August 2002

Metabolite identification can provide critical information for further synthesis during the lead optimization stage of drug discovery. Fast chromatographic gradient methodology was explored to reduce the analysis time for metabolite identification by liquid chromatography/tandem mass spectrometry while maintaining chromatographic separation of all components of interest. Short HPLC columns (2 cm) containing 3 µm particles were used and the chromatographic conditions involved elevated flow rates (1.0–2.5 mL/min) and fast, full range linear gradients (<2 min). Detection was accomplished by fast scanning triple quadrupole mass spectrometers or a quadrupole time‐of‐flight mass spectrometer. Analysis of liver microsomal incubations of several compounds indicates that separation of isomeric metabolites as well as the parent compound is feasible with analysis times not exceeding 2 minutes. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental validation of Gaussian‐3 lithium cation affinities of amides: implications for the gas‐phase lithium cation basicity scale
Authors: Tsang Yuet , Siu Fung Ming , Ma Ngai Ling , Tsang Chun Wai
Published: August 2002

Using a refined Gaussian‐3 (G3) protocol, the highest level of ab initio calculations reported so far, we have established the Li+ cation binding enthalpy (affinity) at 0 K (in kJ mol−1) for formamide (195.7), N‐methylformamide (209.2), N,N′‐dimethylformamide (220.0), acetamide (211.7), N‐methylacetamide (222.5), and N,N′‐dimethylacetamide (230.1), with an estimated maximum uncertainty of ±8 kJ mol−1. With these six theoretical lithium cation binding affinities as reference values, the absolute Li+ affinities of imidazole and dimethoxyethane were determined by the extended kinetic method, and by adopting the statistical data treatment protocol recently proposed by Armentrout. The Li+ affinities obtained for these two ligands are in good agreement (within 6 kJ mol−1) with recent values determined by the threshold collision‐induced dissociation method, and consistent with the Li+ basicity values first reported by Taft and co‐workers in 1990. Our study confirms that the previously suggested, and recently implemented, downward revision of Taft's original basicity scale by 10.9 kJ mol−1 is justified for ligands with revised basicities less than 151 kJ mol−1. However, for selected ligands with Li+ basicities greater than 151 kJ mol−1, including some of the six amides studied in this work, the reported discrepancy between theoretical and experimental estimates in the revised Li+ basicity scale of Burk et al. is likely to arise from experimental uncertainties. Copyright © 2002 John Wiley & Sons, Ltd.
Remediation of Trapped Free‐Phase LNAPL
Authors: Whitworth T. M. , Elmore Andrew Curtis
Published: August 2002

Free‐phase light nonaqueous phase liquids (LNAPLs) may be trapped in certain stratigraphic and
structural features near or at contaminated sites due to seasonal or other variations in the water table
elevation. The purpose of this article is to point out particular subsurface conditions that are conducive to
trapping of free‐phase LNAPLs and to suggest approaches to remediating LNAPL‐contaminated sites
exhibiting similar subsurface geometry and stratigraphy. To trap free‐phase LNAPL, a structure must have,
in addition to closed contours, an upper boundary with pores small enough so that the LNAPL will not enter them.
This boundary usually consists of clay‐rich sediments. The Lower Mississippi River Valley contains
thousands of these potential traps associated with the geomorphic surfaces mapped as outwash or braided stream
terraces, which are covered with thin layers of backswamp clays. These traps may have closure heights ranging from
about 1 to 7.5 meters or more and have variable lateral extents. Based on surface geomorphic analysis, the
potential LNAPL traps in the Lower Mississippi River Valley range in size from about 0.06 by 0.02 km to 4.19 by
0.69 km. The apparent best remediation strategy for LNAPL sites located on these geomorphic surfaces, which
contain these trapping structures, is to first determine if free‐phase is present. If it is present, and is
contained in one of the stratigraphic traps, the free‐phase can be removed through an extraction well or
wells located at the trap apex. Geomorphic analysis and geophysical surveys may be necessary to accurately locate
the trap apex. The remaining residual hydrocarbons might best be remediated using an air sparging system, although
it may be necessary to install air vents through the clay cap by backfilling augured holes with washed sand. If it
is determined that, due to geometry, the dissolved LNAPL plume cannot be adequately remediated using an air
sparging system, then groundwater circulation wells or monitored natural attenuation may be alternative
technologies. © 2002 Wiley Periodicals, Inc.
Bioremediation of Dissolved and Free Phase Oil in Wastewater from Equipment Maintenance Activities
Authors: Guerin Turlough F.
Published: August 2002

Land treatment facilities can provide effective treatment of secondary oily wastewater from maintenance
operations, particularly in arid climates. Soil and underlying groundwater from a land treatment facility, which
has been operating for eight years, were analyzed to determine the effectiveness of using bioremediation for the
treatment of dissolved and free‐phase oil in maintenance wastewater. The study was conducted at a mining
site in Western Australia. The facility was capable of treating 140 kiloliters (kL) of oily wastewater
per day. The average petroleum hydrocarbon content of the wastewater was 2 percent weight per volume
(w/v) based on data available for the first five years. The soil data indicate that the land
treatment process has been operating efficiently even at high wastewater loadings with maximum degradation rates
of 10–242 mg/kg per day. Based on the soil data, there is no evidence of accumulation of any metal or
polycyclic aromatic hydrocarbon (PAH) compounds. The land treatment facility has led to only low
levels of TPH (total petroleum hydrocarbons) contamination (<4 ppm) in the underlying
groundwater. However, nitrate concentrations in the groundwater were shown to increase over the first five years
of the facility's operation. This article reports and discusses the operational data from the land
treatment process, illustrating its effectiveness in treating oily wastewater. © 2001 John Wiley &
Sons, Inc.
Advantages of finite‐structured environmental insurance policies
Authors: Murphy Michael J. , Renshaw Reynolds B.
Published: August 2002

Over the last five years, insurance products have been expanded to assist companies better manage environmental
liabilities. The most progressive of these products is a finite‐structured program whereby the convergence
of insurance and financial markets expand the meaning of “alternative risk transfer.” Finite programs
blend financial markets and banking concepts with risk transfer concepts to more effectively and efficiently allow
the insured to manage the financial implications of its environmental liabilities. This article presents the
advantages of using finite‐structured environmental insurance policies and discusses how potential insureds
can protect against several types of remediation project risks, including cleanup costs, inflation uncertainty,
and variability in investment returns. © 2001 John Wiley & Sons, Inc.
Robust and non‐linear control of marine system
Authors: Yamamoto Ikuo
Published: August 2002

Robust and non‐linear control theories useful for real marine system are developed and applied to a variety of marine vehicles and equipments. In the thesis, the basic principle of marine control system development is described and advanced robust control algorithm and non‐linear control algorithm applicable for real system are shown. It's effectiveness is confirmed by numerical simulations, tank tests, and sea trial tests. Copyright © 2001 John Wiley & Sons, Ltd.
Non‐diagonal controllers in MIMO quantitative feedback design
Authors: Boje Edward
Published: August 2002

This paper discusses multivariable quantitative feedback design through the use of controllers with off‐diagonal elements. Controller design for multivariable plants with significant uncertainty is simpler and potentially less conservative if some sort of dominance is achieved (by reducing the interaction effect of off‐diagonal plant elements) before a diagonal (decentralized) controller design is attempted. Traditional approaches for achieving dominance are not applicable when plant uncertainty must be considered. This paper discusses parallel and series implementations and for the latter, a pseudo‐Gauss elimination approach to the design has been developed. The interaction is measured using the Perron–Frobenius root of an interaction matrix. In some applications, it is possible to trade off individual plant cases against each other in order to reduce to the worst‐case interaction over the entire plant set. Copyright © 2002 John Wiley & Sons, Ltd.
Geared robot manipulators with a jointed unit: Kinematic analysis and its application
Authors: Chen Dar‐Zen , Huang Yu‐Chu
Published: August 2002

An efficient and systematic methodology for the kinematic analysis of geared robot manipulators (GRMs) with a jointed unit is presented. It is shown that, by decomposing mechanical transmission lines of a GRM into serially connected jointed and disjointed units, kinematic relation between local inputs and local outputs of admissible jointed units can be systematically formulated. Accordingly, angular displacements of input links with respect to their associated primary links can be symbolically expressed in terms of joint angles by a unit‐by‐unit evaluation procedure. This unit‐by‐unit evaluation procedure provides better kinematic insights into how input torques are transmitted to various joints. It is also shown that an actuator in a GRM with a jointed unit can drive nonconsecutive joints by proper design of its gear train. A 3 degrees of freedom GRM with a jointed unit is used as an illustrative example. © 2001 John Wiley & Sons, Inc.
Hydrochemistry of the hyporheic zone in salmon spawning gravels: a preliminary assessment in a degraded agricultural stream
Authors: Soulsby C. , Malcolm I.A. , Youngson A.F.
Published: August 2002

Hydrochemical changes were monitored in a simulated, sea run salmon redd in a small agricultural stream in northeast Scotland following the 1998–1999 spawning season. Immediately after redd construction, the hydrochemical characteristics of hyporheic water, at depths of 0.1 m and 0.3 m, were very similar to stream water. These apparently well‐mixed waters were alkaline, well‐oxygenated and enriched in nutrients. In the weeks and months following redd construction, clear and statistically significant differences in the chemistry of stream and hyporheic waters were observed. Typically, hyporheic water had lower concentrations of dissolved oxygen (mean 7.35 mg L−1 at 0.3 m depth) than stream waters (mean=11.26 mg L−1). Alkalinity, calcium, sulphate and conductivity levels tended to be higher in hyporheic waters, with concentrations increasing with depth. These data implied an increasing influence of groundwater with depth in the hyporheic zone following redd construction; an inference supported by subsequent hydraulic head measurements, which revealed an upwards groundwater flux in the stream bed. However, groundwater–surface water interactions were dynamic and complex: road salts eluted into the stream during periods of snowmelt simulated tracer experiments that implied that a reversed hydraulic gradient may occur at high flows with deeper streamwater penetration and mixing in the hyporheic zone. High flows also result in the mobilization of fine sediments from the stream bed which subsequently infiltrated into spawning gravels. These appear to cause ‘capping’ of redds and probably reduce the hydraulic conductivity of the redd matrix. Infiltrating sediments also contain a small, but probably important organic component, the decomposition of which may contribute to oxygen consumption and nutrient mineralization in the hyporheic zone. Copyright © 2001 John Wiley & Sons, Ltd.
Very rapid mixing of the Glauber dynamics for proper colorings on bounded‐degree graphs
Authors: Dyer Martin , Greenhill Catherine , Molloy Mike
Published: August 2002

Recent results have shown that the Glauber dynamics for graph colorings has optimal mixing time when (i) the graph is triangle‐free and Δ‐regular and the number of colors k is a small constant fraction smaller than 2Δ, or (ii) the graph has maximum degree Δ and k=2Δ. We extend both these results to prove that the Glauber dynamics has optimal mixing time when the graph has maximum degree Δ and the number of colors is a small constant fraction smaller than 2Δ. © 2002 John Wiley & Sons, Inc. Random Struct. Alg., 20, 98–114, 2002
Randomized allocation processes
Authors: Czumaj Artur , Stemann Volker
Published: August 2002

Many dynamic resource allocation and on‐line load balancing problems can be modeled by processes that sequentially allocate balls into bins. The balls arrive one by one and are to be placed into bins on‐line without using a centralized controller. Ifnballs are sequentially placed intonbins by placing each ball in a randomly chosen bin, then it is widely known that the maximum load in bins is ln n /ln ln n⋅(1+o(1)) with high probability. Azar, Broder, Karlin, and Upfal extended this scheme, so that each ball is placed sequentially into the least full ofdrandomly chosen bins. They showed that the maximum load of the bins reduces exponentially and is ln ln n/In d+Θ(1) with high probability, providedd<2. In this paper we investigate various extensions of these schemes that arise in applications in dynamic resource allocation and on‐line load balancing. Traditionally, the main aim of allocation processes is to place balls into bins to minimize the maximum load in bins. However, in many applications it is equally important to minimize the number of choices performed (the allocation time). We study adaptive allocation schemes that achieve optimal tradeoffs between the maximum load, the maximum allocation time, and the average allocation time. We also investigate allocation processes that may reallocate the balls. We provide a tight analysis of a natural class of processes that each time a ball is placed in one ofdrandomly chosen bins may move balls among thesedbins arbitrarily. Finally, we provide a tight analysis of the maximum load of the off‐line process in which each ball may be placed into one ofdrandomly chosen bins. We apply this result to competitive analysis of on‐line load balancing processes. ©2001 John Wiley & Sons, Inc. Random Struct. Alg., 18: 297–331, 2001
Hamilton cycles containing randomly selected edges in random regular graphs
Authors: Robinson R.W. , Wormald N.C.
Published: August 2002

In previous papers the authors showed that almost all d‐regular graphs for d≤3 are hamiltonian. In the present paper this result is generalized so that a set of j oriented root edges have been randomly specified for the cycle to contain. The Hamilton cycle must be orientable to agree with all of the orientations on the j root edges. It is shown that the requisite Hamilton cycle almost surely exists if $j=o(\sqrt{n}),$ and the limiting probability distribution at the threshold $j=c\sqrt{n}$ is determined when d=3. It is a corollary (in view of results elsewhere) that almost all claw‐free cubic graphs are hamiltonian. There is a variation in which an additional cyclic ordering on the root edges is imposed which must also agree with their ordering on the Hamilton cycle. In this case, the required Hamilton cycle almost surely exists if j=o(n2/5). The method of analysis is small subgraph conditioning. This gives results on contiguity and the distribution of the number of Hamilton cycles which imply the facts above. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 19: 128–147, 2001
Data collection from the Antarctic region through a W‐band low Earth orbit satellite
Authors: Ruggieri Marina , Falzini Stefano , Saggese Enrico , Corbelli Filippo , Bonifazi Carlo
Published: August 2002

The DAVID (DAta and Video Interactive Distribution) mission is being carried out in the framework of the Science Small Missions Program of the Italian Space Agency. The mission is aimed at the deployment of two scientific telecommunication experiments through a low Earth orbit (LEO) satellite. The paper will focus on one of these experiments, that will test a satellite system architecture for the exchange of a large amount of data and high definition images through a W‐band link and a Ka‐band inter‐satellite link between the LEO and the ARTEMIS satellite. The proposed architecture, that will explore various innovative aspects, will also allow for the first time the distribution of large volumes of scientific data collected from the Antarctic region and other extremely remote areas of the Earth. The availability of a return link in the envisaged system will also allow interactive control of the various laboratories located in the remote sites. Copyright © 2001 John Wiley & Sons, Ltd.
Neural network implementation of a fade countermeasure controller for a VSAT link
Authors: Malygin Andrei , Filip Miodrag , Vilar Enric
Published: August 2002

In this paper, an algorithm and its practical implementation to activate adaptive modulation as a fade countermeasure (FCM) is presented. Characteristics of the algorithm are derived from the propagation studies and the algorithm uses a simple four parameter model. A neural network architecture was used to implement the decision making block of the controller. The algorithm has been implemented on a fixed point DSP. An experimental set‐up with an emulated Ka‐band satellite link and a terrestrial return path connection has been used with previously recorded propagation data for experimental verification and performance analysis. Performance of the implemented FCM system is compared with that of fixed, non‐adaptive systems. Over concatenated rain events, the adaptive system yields better throughput at or below a given BER than any fixed mode system and only marginally worse BER availability than the most robust scheme in the system. The FCM is thus essential if throughput is of importance as well as availability. The added complexity of the FCM system is not great by contemporary technology standards and is, in authors' opinion, well worth the investment. Copyright © 2002 John Wiley & Sons, Ltd.
Efficient integration of isochronous and data bursty traffics in low earth orbit‐mobile satellite systems
Authors: Andreadis Alessandro , Angioloni Riccardo , Fantacci Romano , Giambene Giovanni
Published: August 2002

This paper focuses on the radio resource management in low earth orbit‐mobile satellite systems (LEO‐MSSs) based on a time division multiple access (TDMA) air interface. A novel demand–assignment medium access control (MAC) protocol, named DRAMA+ (dynamic resource assignment multiple access—enhanced version), is proposed, where voice and Web traffic sources obtain transmission slots through requests sent by means of a random access phase. The round‐trip propagation delay (RTD) of LEO‐MSSs prevents an immediate feedback for each transmission attempt. Therefore, the main concern of the DRAMA+ scheme is to realize an efficient access phase. All the transmission requests successfully received at the satellite are managed by an on board scheduler. We have shown that DRAMA+ outperforms other techniques appeared in the literature in terms of voice quality, transmission delays for bursty data traffics and resource utilization. Moreover, a performance analysis of an ideal version of the DRAMA+ scheme has permitted us to prove the potentialities of the proposed DRAMA+ technique. Stability issues have been addressed as well as the impact on the DRAMA+ performance of the LEO satellite constellation RTD value. Copyright © 2002 John Wiley & Sons, Ltd.
A science teacher's reflections and knowledge growth about STS instruction after actual implementation
Authors: Tsai Chin‐Chung
Published: August 2002

The major purpose of this study was to describe a science teacher's views of STS (Science–Technology–Society) instruction and what she acquired after implementing a two‐semester STS‐oriented science course in a high school of Taiwan. Upon analysis of the teacher's journals, interview data, concept maps, and relevant student questionnaire responses, this study revealed the following findings. The teacher believed that STS instruction was a potential way of practicing so‐called “constructivist” teaching and her pedagogical knowledge about STS showed a considerable growth. As a result of STS instruction, her epistemological views of science seemed to progress toward more constructivist‐oriented views of science. The heavy content load of Taiwan's national curriculum, regular cross‐class standard tests, the lack of peers' or administrative support, the resource limitations in Chinese language, and the cultural impacts were identified as major factors that inhibited her implementation of STS instruction. © 2001 John Wiley & Sons, Inc. Sci Ed 86:23–41, 2001.
A supporting system for verification among models of the UML
Authors: Ohnishi Atsushi
Published: August 2002

We propose a method for verifying the consistency among UML (Unified Modeling Language) models and for modifying errors of the models. We have been developing a system based on the proposed method. In this paper, the outline of the method will be described. The system configuration and its examples will be illustrated with a simple news system. We also show the usefulness of our method and the system through the example. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(4): 1–13, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10016
A translation aid system by retrieving bilingual news database
Authors: Kumano Tadashi , Goto Isao , Tanaka Hideki , Uratani Noriyoshi , Ehara Terumasa
Published: August 2002

Machine translation technology is currently incapable of producing translations of the high quality required for purposes such as broadcast news. Such translations still require skilled human translators. We have developed a translation aid system to support translators in such tasks. The system retrieves news articles by answering user queries, and shows the entire article together with the corresponding translated article. The system does not require manual alignment of each sentence with its translation when storing articles in a database. Thus, it is capable of handling flexible translations. Moreover, the system helps users learn not just the translations for queried expressions, but also the facts described in the articles, which can aid in producing good translations. The results of a user inquiry demonstrated the validity of the system. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(8): 19‐29, 2002; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/scj.10072
Design of medical teleconsultation support system using super‐high‐definition imaging system
Authors: Yamaguchi Takahiro , Sakano Toshikazu , Fujii Tatsuya , Ando Yutaka , Kitamura Masayuki
Published: August 2002

A medical teleconsultation is a service to connect a provincial clinic to a central hospital, and enable a central medical specialist to offer diagnosis support to a remote doctor. This research aims to clarify the features required to realize such services and such systems. We have constructed a telemedicine system by combining a high‐speed network, a medical image database, a super‐high‐definition imaging system, and an IP‐based video conferencing system. Based on this system, we developed the medical teleconsultation support system. Using the system, we performed experiments on medical teleconsultation in which two doctors in different places inspected the same image and discussed the appropriate radiation therapy. Through these experiments, we proved the usability of the collaborative work functions implemented on the system, such as the image preloading function to realize high‐speed image display switching regardless of network speed, the synchronized image‐display function, and the shared pointer display function. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(8): 9–18, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10075
Whisper: A wearable handset
Authors: Fukumoto Masaaki , Tonomura Yoshinobu
Published: August 2002

“Whisper,” a handset that can be worn on the wrist, transmits incoming sound via bone conduction through the insertion of a finger on the hand with the device into the ear. The position of a hand touching an ear resembles the way in which a conventional handset (telephone) is used, and even when the device is operated using voice commands, people nearby will regard this as “using a telephone” and experience little discomfort. In addition, the use of bone conduction to receive calls allows for calls in noisy environments without raising the volume [under 90 dB (A) of noise, –12 dB compared to a conventional handset]. Outgoing speech is achieved through a microphone attached to the inside of the wrist. By placing the finger in the ear, feedback of the speaking voice is created, and the voice does not need to be raised even under noisy conditions, virtually eliminating discomfort to anyone nearby [under 90 dB (A) of noise, –6 dB compared to a conventional handset]. In addition to its use in a voice interface for a PDA worn on the wrist, Whisper can also be used for cellular phones and other telephone applications. © 2001 Scripta Technica, Syst Comp Jpn, 32(4): 38–47, 2001
A method of inductive machine discovery based on experimental data acquisition
Authors: Murata Tsuyoshi , Shimura Masamichi
Published: August 2002

Acquisition of experimental data is very important in the discovery of theorems and rules. In most existing discovery systems, extensive subject knowledge is required to evaluate experimental results, or numerous experiment plans are prelearned. On the other hand, few if any reports explore methods of discovery based on experimental data acquisition, not relying heavily on subject knowledge. This paper presents a method of discovering theorems in the field of plane geometry experimentally. Generation and observation of planar figures corresponds to experiments in terms of preparation for data acquisition. The EXPEDITION discovery system based on experimental data acquisition was developed; this system performs inductive discovery of theorems using numerical data obtained by generation and observation of figures. Hypotheses are advanced using segment lengths and angle magnitudes, and then verified using similar figures. EXPEDITION was able not only to rediscover well‐known theorems such as Thales's theorem, but also to originate new theorems. © 2001 Scripta Technica, Syst Comp Jpn, 32(4): 69–75, 2001
Measurement of surface orientations of transparent objects using polarization in highlight
Authors: Saito Megumi , Sato Yoichi , Ikeuchi Katsushi , Kashiwagi Hiroshi
Published: August 2002

There are no simple noncontact methods available to measure a transparent object's shape. In this context, the authors suggest highlight polarization analysis as a method for noncontact measurement of the transparent object's shape. Highlight is the light observed as specular reflection component, which is the part of reflected light that remains nearly unchanged (that is, very much similar to source light). Highlight, however, is only observed near the direction of regular reflection, which normally covers just a small part of the object's surface. As a solution, use of spherical area light source is offered; with such a light source, normal direction can be found across the whole object's surface without any contact. © 2001 Scripta Technica, Syst Comp Jpn, 32(5): 64–71, 2001