bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantization on curved surfaces
Authors: Mladenov Ivaïlo M. 
Published: October 2002

AbstractAfter a short review of the existing methods for quantization of curved manifolds, the free particle motions or the so‐called geodesic flows on axisymmetrical prolate and oblate ellipsoids are quantized using the isomorphism established by Neumann of these systems and the harmonic oscillator restricted to the unit sphere. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Mechanism of the oxidation reaction of Cu with N2O via nonadiabatic electron transfer
Authors: Kryachko Eugene S. , Tishchenko Oksana , Nguyen Minh Tho 
Published: October 2002

AbstractWe treat the present work as an attempt to elucidate the mechanism of the oxidation reaction of the Cu atom by nitrous oxide based on our recent work (Kryachko, E. S.; Vinckier, C.; Nguyen, M. T. J Chem Phys 2001, 114, 7911) on the electron attachment to this molecule. We suggest that the title reaction in its Arrhenius regime occurs via the nonadiabatic electron transfer from Cu to the oxygen atom at the crossing of the potential energy surfaces Cu(4s 2S1/2) + N2O(X 1Σ+) and Cu+ + N2O−, where the latter is linked to the complex N2O− originated from the higher‐energy T‐shape N2O molecule and discovered in the aforementioned work. The calculations performed in the present work using a variety of quantum chemical methods support the proposed model. We also show the existence of other reaction pathways of the title reaction that, we believe, contribute to its non‐Arrhenius behavior observed experimentally at T > 1190 K. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Inverse 15N‐metabolic labeling/mass spectrometry for comparative proteomics and rapid identification of protein markers/targets
Authors: Wang Y. Karen , Ma Zhixiang , Quinn Douglas F. , Fu Emil W. 
Published: October 2002

AbstractThe inverse labeling/mass spectrometry strategy has been applied to protein metabolic 15N labeling for gel‐free proteomics to achieve the rapid identification of protein markers/targets. Inverse labeling involves culturing both the perturbed (by disease or by a drug treatment) and control samples each in two separate pools of normal and 15N‐enriched culture media such that four pools are produced as opposed to two in a conventional labeling approach. The inverse labeling is then achieved by combining the normal 14N‐control with the 15N‐perturbed sample, and the 15N‐control with the 14N‐perturbed sample. Both mixtures are then proteolyzed and analyzed by mass spectrometry (coupled with on‐line or off‐line separation). Inverse labeling overcomes difficulties associated with protein metabolic labeling with regard to isotopic peak correlation and data interpretation in the single‐experiment approach (due to the non‐predictable/variable mass difference). When two data sets from inverse labeling are compared, proteins of differential expression are readily recognized by a characteristic inverse labeling pattern or apparent qualitative mass shifts between the two inverse labeling analyses. MS/MS fragmentation data provide further confirmation and are subsequently used to search protein databases for protein identification. The methodology has been applied successfully to two model systems in this study. Utilizing the inverse labeling strategy, one can use any mass spectrometer of standard unit resolution, and acquire only the minimum, essential data to achieve the rapid and unambiguous identification of differentially expressed protein markers/targets. The strategy permits quick focus on the signals of differentially expressed proteins. It eliminates the detection ambiguities caused by the dynamic range of detection. Finally, inverse labeling enables the detection of covalent changes of proteins responding to a perturbation that one might fail to distinguish with a conventional labeling experiment. Copyright © 2002 John Wiley & Sons, Ltd.
Quantification of clenbuterol in equine plasma, urine and tissue by liquid chromatography coupled on‐line with quadrupole time‐of‐flight mass spectrometry
Authors: Guan Fuyu , Uboh Cornelius E. , Soma Lawrence R. , Luo Yi , Li Runbo , Birks Eric K. , Teleis Donna , Rudy Jeffrey A. , Tsang Deborah S. 
Published: October 2002

AbstractClenbuterol (CBL) is a potent β2‐adrenoceptor agonist used for the management of respiratory disorders in the horse. The detection and quantification of CBL can pose a problem due to its potency, the relatively low dose administered to the horse, its slow clearance and low plasma concentrations. Thus, a sensitive method for the quantification and confirmation of CBL in racehorses is required to study its distribution and elimination. A sensitive and fast method was developed for quantification and confirmation of the presence of CBL in equine plasma, urine and tissue samples. The method involved liquid‐liquid extraction (LLE), separation by liquid chromatography (LC) on a short cyano column, and pseudo multiple reaction monitoring (pseudo‐MRM) by electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (ESI‐QTOF‐MS/MS). At very low concentrations (picograms of CBL/mL), LLE produced better extraction efficiency and calibration curves than solid‐phase extraction (SPE). The operating parameters for electrospray QTOF and yield of the product ion in MRM were optimized to enhance sensitivity for the detection and quantification of CBL. The quantification range of the method was 0.013–10 ng of CBL/mL plasma, 0.05–20 ng/0.1 mL of urine, and 0.025–10 ng/g tissue. The detection limit of the method was 13 pg/mL of plasma, 50 pg/0.1 mL of urine, and 25 pg/g of tissue. The method was successfully applied to the analysis of CBL in plasma, urine and various tissue samples, and in pharmacokinetic (PK) studies of CBL in the horse. CBL was quantified for 96 h in plasma and 288 h in urine post‐administration of CLB (1.6 µg/kg, 2 × daily × 7 days). This method is useful for the detection and quantification of very low concentrations of CBL in urine, plasma and tissue samples. Copyright © 2002 John Wiley & Sons, Ltd.
Metal ion migration model for cationization of low‐molecular‐weight oligomers of poly(ethylene glycol) dodecyl ether in matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Togashi Hisashi , Kobayashi Yoshinori 
Published: October 2002

AbstractThe process by which cationized oligomers of poly(ethylene glycol) dodecyl ether [CH3(CH2)11(OCH2CH2)nOH, n = 1–8] are formed in matrix‐assisted laser desorption/ionization mass spectrometry was investigated. The observed relative intensities of molecules cationized by Li+,Na+, or K+ were analyzed using a one‐dimensional random walk model, assuming metal ion migration in the ethylene glycol chain of the oligomer and loss from the chain as the result of lack of sufficient coordination sites at the chain ends. Copyright © 2002 John Wiley & Sons, Ltd.
Speciation of Fe(III)–chelate complexes by electrospray ionization ion trap and laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry
Authors: Neubert Hendrik , Hider Robert C. , Cowan David A. 
Published: October 2002

AbstractElectrospray ionization mass spectrometry (ESI‐MS) was employed as a relatively simple technique to investigate the speciation of complexes formed between Fe(III), the iron chelator 3‐hydroxy‐2‐methyl‐1‐propyl‐1H‐pyridin‐4‐one (L) and citrate. The major species in aqueous solution at pH 6.0 of a 1:2:10 molar mixture Fe(III)/L/citrate is the Fe(III)L2 complex. No evidence for a mixed citrate complex was observed. Furthermore, evidence for the existence of a number of dimeric iron species is presented. All observed species in ESI were singly charged as evidenced by the isotopic envelopes. Laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (LDI‐FTICRMS) provided data that complemented and confirmed the ESI findings. We also demonstrate the possibility of chelated Fe(III) being converted to Fe(II) under ESI and LDI conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Mass spectrometric studies of benzoxazine resorcarenes
Authors: Hakala Kati , Nuutinen Jari M. J. , Straub Thomas , Rissanen Kari , Vainiotalo Pirjo 
Published: October 2002

AbstractEleven differently substituted 3,4‐dihydro‐2H‐1,3‐benzoxazine resorcarenes were studied by electrospray ionisation (ESI) and matrix‐assisted laser desorption/ionisation (MALDI) mass spectrometry, using Fourier transform ion cyclotron resonance (FT‐ICR) and time‐of‐flight (TOF) mass spectrometers, respectively. Under ESI conditions it was possible to transfer the intact resorcarenes from solution to the gas phase, yielding [M + H]+ and [M + 2H]+ ions as the main ions observed. Energy increase of the ions induced ready decomposition through successive eliminations of four CH2NR groups. Ion‐molecule reactions showed that the ionising proton was situated somewhere inside the molecule and could not be reached with neutral reagent gases. In the host‐guest complexation experiments, the benzoxazine resorcarenes studied turned out to be poor hosts for alkali metal and ammonium ions. In MALDI experiments, 2,5‐dihydroxybenzoic acid proved to be the best matrix for these compounds. However, the intensity of the [M + H]+ ions was low for all compounds, and extensive fragmentation with consecutive elimination of CH2NR groups was observed. Copyright © 2002 John Wiley & Sons, Ltd.
Reproductive success of the interior least tern (Sterna antillarum) in relation to hydrology on the Lower Mississippi River
Authors: Dugger Katie M. , Ryan Mark R. , Galat David L. , Renken Rochelle B. , Smith John W. 
Published: October 2002

AbstractThe annual hydrograph of large rivers, including flood pulses and low‐flow periods, is believed to play a primary role in the productivity of biota associated with these ecosystems. We investigated the relationship between river hydrology and Interior least tern (Sterna antillarum) reproductive success on the Lower Mississippi River from April to July 1986–1993. The number of fledglings produced per adult pair was negatively correlated with July mean (r=−0.95, p=0.0004) and July maximum river elevation (r=−0.97, p=0.0001), but no other aspects of river hydrology were related to tern reproduction. Low‐water elevations in July may benefit least tern reproductive success by increasing sand island area or the area of shallow‐water habitat that surrounds islands. Loss of deep‐water habitats in conjunction with an increase in shallow habitat during stage decreases may concentrate fish prey in shallow‐water habitats and backwater areas, thereby increasing food availability during chick‐rearing. Copyright © 2002 John Wiley & Sons, Ltd.
Dynamic fade restoration in Ka‐band satellite systems
Authors: Paraboni A. , Capsoni C. , Masini G. , Poiares Baptista J. P. V. , Riva C. 
Published: October 2002

AbstractAtmospheric precipitation can seriously affect the propagation of centimeter and millimeter electromagnetic waves. As a consequence, in some applications, it is necessary to make use of a fade countermeasure technique in order to satisfy the system availability and quality requirements. This study analyses the performance of a satellite‐based system in geo‐stationary orbit operating at 20 GHz, dynamically assigning the antenna directivity pattern to counteract tropospheric attenuation. The on‐board power is spatially distributed over the covered region to minimize, at any time, the number of users undergoing outage because of the tropospheric attenuation. Both the aspects of broadcasting and telecommunication services are addressed. The reflector antenna of the system is supposed to be illuminated by a cluster of feeds driven by a set of excitation coefficients, continuously modified and optimized according to the meteorological information derived by processing METEOSAT satellite data and ECMWF (European Centre for Medium‐Range Weather Forecasts) data. Copyright © 2002 John Wiley & Sons, Ltd.
A mechanism for inferring approximate solutions under incomplete knowledge based on rule similarity
Authors: Nguyen Viet Ha , Ishikawa Tsutomu , Abe Akinori 
Published: October 2002

AbstractThis paper proposes an inference method which can obtain an approximate solution even if the knowledge stored in the problem‐solving system is incomplete. When a rule needed for solving the problem does not exist, the problem can be solved by using rules similar to the existing rules. In an implementation using SLD procedure, a resolution is executed between a subgoal and a rule if an atom of the subgoal is similar to the consequence atom of the rule. Similarities between atoms are calculated using a knowledge base of words with account of the reasoning situation, and the reliability of the derived solution is calculated based on these similarities. If many solutions are obtained, they are grouped into classes of similar solutions and a representative solution is then selected for each class. The proposed method was verified experimentally by solving simple problems. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(9): 78–89, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1154
A three‐dimensional model for the tooth‐loss patterns by multi‐plane regression analysis
Authors: Sasahara Hisako , Sasahara Hideo , Kawamura Makoto 
Published: October 2002

AbstractThe construction of dental condition models is one of the useful methods for analysis of epidemiological surveys. The purpose of this investigation was to make a simple model with clear turning points for the longitudinal tooth‐loss patterns of Japanese adults by means of multi‐plane regression analysis. Since 1957, the Japanese Ministry of Health and Welfare has carried out national surveys of dental conditions every six years.The data of present tooth numbers by age (24–79 years) and sex from these surveys were used for this study. When there are turning points between two variables, intersecting straight lines regression is a valid means. However, a new method was developed so that the data of this study had three variables. The new three‐dimensional model by multi‐plane regression analysis seemed to fit tooth‐loss patterns of Japanese adults within three phases. Younger subjects are represented in the first phase followed by the third phase of elders, where tooth loss was rather slow. However, in the second phase, middle‐aged subjects, people lost their teeth rapidly. Thus, prolongation of the first phase could be an important factor to improve overall dental health. Copyright © 2002 John Wiley & Sons, Ltd.
The predictive value of microbiologic diagnostic tests if asymptomatic carriers are present
Authors: Gunnarsson Ronny K. , Lanke Jan 
Published: October 2002

AbstractIf a proper gold standard is not available, then the predictive value of a test cannot be estimated. In this paper the concept of etiologic predictive value (EPV) is introduced. It is a quantity that will yield the predictive value of a test to predict presence of a specified disease in situations for which no proper gold standard is available. This is achieved by using information obtained from a healthy control population. This quantity requires that the marker in our test is present in all individuals having the specified disease, as in the case where the marker is the aetiologic factor for the specified disease. Furthermore this quantity requires that asymptomatic carriers are present. This means that not all individuals with the marker has the specified disease. EPV is developed with special reference to the evaluation of bacterial cultures, or rapid tests to detect a bacterium, but the quantity might be used in other circumstances as well. EPV is applied to an example in which conventional throat culture is evaluated. Further information concerning EPV can be found at http://www.infovice.se/fou/epv. Copyright © 2002 John Wiley & Sons, Ltd.
Receiver operating characteristic (ROC) analysis for diagnostic examinations with uninterpretable cases
Authors: Lu Ying , Heller Daniel N. , Zhao Shoujun 
Published: October 2002

AbstractReceiver operating characteristic (ROC) analysis plots true positive rates over false positive rates to describe the discriminatory power of a test to differentiate between two specifiable populations (that is ‘normal’ from ‘abnormal’) using a continuous dichotomous threshold. This assumes that the test separates cases into observed ‘normal’ or ‘abnormal’. However, in practice many tests have some uninterpretable results as an inherent feature of the test itself, whether independent or dependent on the sample populations. This paper defines a method to describe the ability of tests to discriminate between specifiable populations when uninterpretable results occur non‐informatively about disease status. A mixed model modified ROC curve is developed. Formulae to estimate the area under the modified ROC curve are given. Comparisons of conventional with the mixed model ROC analysis are shown in mathematical formulae as well as simulated experiments. An example of diagnosis of spinal fracture in renal transplant patients is presented. Copyright © 2002 John Wiley & Sons, Ltd.
Robustness of choice of number of doses for maximum likelihood estimation of the ED50 in bioassay
Authors: Huang Yangxin 
Published: October 2002

AbstractA number of studies have looked at the choice of number of doses for estimating the median effective dose (ED50) when the form of a dose–response curve is correctly assumed (see, for example, Müller and Schmitt, 1990). Here we address the question of the robustness of number of doses chosen using Müller and Schmitt's method when a logistic dose–response curve is incorrectly assumed. The underlying true dose–response curves considered include the probit, cubic‐logistic and Aranda‐Ordaz asymmetric models. The simulation results show that, for the above true dose–response curves and the uniform design density with doses spaced symmetrically or slightly asymmetrically around the assumed ED50, choosing as many doses as possible either minimizes the mean squared error (MSE) or produces a MSE chosen to the minimum. Copyright © 2002 John Wiley & Sons, Ltd.
A Bayesian approach to parameter estimation in HIV dynamical models
Authors: Putter H. , Heisterkamp S. H. , Lange J. M. A. , de Wolf F. 
Published: October 2002

AbstractIn the context of a mathematical model describing HIV infection, we discuss a Bayesian modelling approach to a non‐linear random effects estimation problem. The model and the data exhibit a number of features that make the use of an ordinary non‐linear mixed effects model intractable: (i) the data are from two compartments fitted simultaneously against the implicit numerical solution of a system of ordinary differential equations; (ii) data from one compartment are subject to censoring; (iii) random effects for one variable are assumed to be from a beta distribution. We show how the Bayesian framework can be exploited by incorporating prior knowledge on some of the parameters, and by combining the posterior distributions of the parameters to obtain estimates of quantities of interest that follow from the postulated model. Copyright © 2002 John Wiley & Sons, Ltd.
Plasma isatin is increased in maternal anxiety and obstetrical stress
Authors: Manjari  , Pandey S. , Chakrabarti A. , Pandey L. K. , Bhattacharya S. K. 
Published: October 2002

AbstractIsatin (2,3‐dioxoindole) is a component of tribulin. Tribulin, an inhibitor of monoamine oxidase (MAO) and benzodiazepine (BDZ) receptor binding, has been identified as an endogenous marker of stress and anxiety. In animal experiments, isatin has been found to produce an anxiety‐like action and its level is increased during stress and anxiety. Maternal anxiety and obstetrical complications are two different stressors that can affect perinatal outcome. In this study we investigated plasma isatin levels in maternal anxiety and stress. The study was conducted in 279 pregnant and non‐pregnant women. The patients were stratified into five groups—A, B, C, D and E. Plasma cortisol was measured to assess the intensity of the stressor and plasma isatin was measured by a high‐performance liquid chromatography (HPLC) method. Perinatal outcome was measured by gestational weight and birth weight of the baby. Non‐pregnant women (group D) had a significantly lower plasma isatin level (P < 0.001) compared to women with normal pregnancies (group E), whose plasma isatin was monitored once in each trimester. Patients with anxiety and psychological stress (group B) and patients with obstetrical stress from obstetrical complications (group C) had significantly higher levels of plasma cortisol (P < 0.001) and plasma isatin (P < 0.001) compared to women with normal pregnancies (group A). Perinatal outcome data were significantly lower (P < 0.001) in both groups B and C. In conclusion, our data proved that maternal anxiety and obstetrical complications are two different stressors evidenced by higher plasma cortisol and isatin levels in patients of these two groups. The present study further validated the postulated role of isatin as a marker of anxiety and stress in a clinically relevant condition in humans. Copyright © 2002 John Wiley & Sons, Ltd.
Unix tools as visual programming components in a GUI‐builder environment
Authors: Spinellis Diomidis 
Published: October 2002

AbstractDevelopment environments based on ActiveX controls and JavaBeans are marketed as ‘visual programming’ platforms; in practice their visual dimension is limited to the design and implementation of an application's graphical user interface (GUI). The availability of sophisticated GUI development environments and visual component development frameworks is now providing viable platforms for implementing visual programming within general‐purpose platforms, i.e. for the specification of non‐GUI program functionality using visual representations. We describe how specially designed reflective components can be used in an industry‐standard visual programming environment to graphically specify sophisticated data transformation pipelines that interact with GUI elements. The components are based on Unix‐style filters repackaged as ActiveX controls. Their visual layout on the development environment canvas is used to specify the connection topology of the resultant pipeline. The process of converting filter‐style programs into visual controls is automated using a domain‐specific language. We demonstrate the approach through the design and the visual implementation of a GUI‐based spell‐checker. Copyright © 2001 John Wiley & Sons, Ltd.
Non‐intrusive object introspection in C++
Authors: Chuang Tyng‐Ruey , Kuo Y. S. , Wang Chien‐Min 
Published: October 2002

AbstractWe describe the design and implementation of system architecture to support object introspection in C++. In this system, information is collected by parsing class declarations, and is used to build a supporting environment for object introspection. Our approach is non‐intrusive because it requires no changes in the original class declarations and libraries; hence, binary compatibility between objects before and after the addition of introspective capability is ensured. This is critical if one wants to integrate third‐party class libraries, which are often supplied as black boxes and allow no modification, into highly dynamic applications. We present two applications: the first is automatic I/O support for C++ objects, and the other is interactive exercise of dynamically loaded C++ class libraries. Copyright © 2001 John Wiley & Sons, Ltd.