bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry and high‐performance liquid chromatography study of quantitative and qualitative variation in tarantula spider venoms
Authors: Escoubas Pierre , Corzo Gerardo , Whiteley Brian J. , Célérier Marie‐Louise , Nakajima Terumi 
Published: September 2002

AbstractAnimal venoms are important sources of novel pharmacological tools, useful in biochemical characterization of their receptors. Venom quality control, batch‐to‐batch homogeneity and high reproducibility of venom fractionation and toxin purification are crucial issues for biochemical and pharmacological studies. To address these issues, a study of the variability of tarantula spider venom samples was undertaken. Venom profiles of samples collected from individuals of different age and sex, and from sibling spiders of the same species, were generated by high‐performance liquid chromatography (HPLC) and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and analyzed to assess venom variability and method accuracy. Sex‐linked venom variation was studied on eight species. Clear qualitative differences were observed for six out of eight species, as well as quantitative differences. Age‐related variation studied in Poecilotheria rufilata showed essentially age‐related quantitative differences between adults of both sexes and immature juveniles. The venoms of nine siblings and three wild‐collected Pterinochilus murinus were studied for individual variation, showing only very minor quantitative differences. On the same samples, the quality of MALDI‐TOFMS venom fingerprinting was demonstrated to be highly reproducible. Our results show that tarantula venom peptide fingerprinting is a highly reliable identification method, that pooled batches of venom from several animals can be used for venom purification, that venom composition does not appear to be qualitatively related to ontogenesis in the spiders studied, and that qualitative sex‐linked variation occurs across most species and may be important in activity studies. Copyright © 2002 John Wiley & Sons, Ltd.
Measurements by gas chromatography/pyrolysis/mass spectrometry: fundamental conditions in 2H/1H isotope ratio analysis
Authors: Bilke Steffi , Mosandl Armin 
Published: September 2002

AbstractGas chromatography/pyrolysis/isotope ratio mass spectrometry (GC/P/IRMS) is a relatively new method for on‐line determination of 2H/1H isotope ratios. The influence of different parameters on the 2H/1H isotope ratios obtained in GC/P/IRMS has been thoroughly studied using several flavor compounds, such as 5‐nonanone, linalool, menthol, linalyl acetate and 4‐decanolide. The requirement of ‘conditioning’ the pyrolysis reactor to obtain reliable δ2HV−SMOW values is discussed. Furthermore, the influence of the carrier gas flow of the gas chromatograph on the completeness of pyrolysis and subsequently on the δ2HV−SMOW values is investigated in detail. The linear range of the compounds investigated is determined. The results show that calibrating the GC/P/IRMS system with secondary standard substances is absolutely necessary in order to obtain reliable δ2HV−SMOW values. In view of interlaboratory comparability, validation procedures are recommended. Copyright © 2002 John Wiley & Sons, Ltd.
Identification of omega hydroxy fatty acids in biological samples as their pentafluoropropyl derivatives by gas chromatography/mass spectrometry with positive and negative ion detection
Authors: Zemaitis Michael , Poloyac Samuel , Frye Reginald 
Published: September 2002

AbstractA simple one‐step procedure for derivatization of the omega hydroxy fatty acids 20‐hydroxyeico‐tetraeonic acid and 12‐hydroxylauric acid is presented. The procedure involves acylation of the terminal hydroxy group and esterification of the carboxylic acid with a mixture of pentafluoropropionic anhydride and pentafluoropropanol. Positive and negative ion spectra for the derivatives are presented. The procedure was used to demonstrate conversion of arachidonic acid to 20‐hydroxyeicosatetraeonic acid and lauric acid to 12‐hydroxylauric acid in kidney microsomal incubations. The reaction appears to be specific, since derivatives of subterminal fatty acids (secondary alcohols) could not be detected. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative analysis of diclazuril in animal plasma by liquid chromatography/electrospray ionization mass spectrometry
Authors: Croubels Siska , Cherlet Marc , Backer Patrick De 
Published: September 2002

AbstractA novel, sensitive and specific method for the quantitative determination of diclazuril in animal plasma using liquid chromatography combined with electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) with negative ion detection is presented. Extraction of the samples was performed with a rapid deproteinization step using acetonitrile. Chromatography of diclazuril and the internal standard was achieved on a Nucleosil ODS 5‐µm column, using a gradient elution with 0.01 M ammonium acetate and acetonitrile. To obtain the highest sensitivity and specificity possible, the mass spectrometer was operated in the multiple reaction monitoring (MRM) mode. The method was validated according to the requirements defined by the European Community. Calibration curves using plasma fortified between 1–100 ng/mL and 100–2000 ng/mL showed good linear correlation (r ≥ 0.9991, goodness‐of‐fit coefficient ≤7.0%). The trueness and within‐run precision at 50 and 500 ng/mL did not exceed 8.8 and 10.5%, respectively. The between‐run precision for the analysis of quality control samples at 50 and 1000 ng/mL was within 11.7%. The most striking advantage of the proposed method was the high sensitivity and specificity achieved. A limit of quantification of 1 ng/mL was obtained, for which the trueness and precision also fell within acceptable limits. Using a signal‐to‐noise ratio of 3:1, the limit of detection was calculated to be 0.03 ng/mL. The method has been successfully used for the quantitative determination of diclazuril in plasma samples from treated sheep, demonstrating the usefulness of the developed method for application in the field of pharmacology and pharmacokinetics. Copyright © 2002 John Wiley & Sons, Ltd.
New example of proline‐induced fragmentation in electrospray ionization mass spectrometry of peptides
Authors: Maux Delphine , Enjalbal Christine , Martinez Jean , Aubagnac Jean‐Louis 
Published: September 2002

AbstractThe positive ion electrospray ionization (ESI+) mass spectra of peptides usually display only protonated molecules provided that soft ionization conditions are applied (low cone voltage to prevent in‐source dissociations). Such ions can be multiply charged depending on the molecular weight of the studied compounds. We have experienced an unexpected behavior during the ESI analysis of a modified peptide of relatively high mass (3079 Da). A specific fragmentation occurred even under soft energetic conditions, leading to a mass spectrum containing multiply charged molecular and fragment ions. The selective rupture involved the amide bond between the glutamic acid and proline residues (E‐P sequence). The successive replacement of each amino acid by an alanine residue (positional scanning study) was undertaken to assess which part of the sequence induced such selective and abundant fragmentation on multiply charged species. The succession P‐P was evidenced as the minimum unit giving rise to the first peptide bond rupture in the sequence X‐P‐P. Any acidic amino acid at the X position (X = D, E) favored the fragmentation by an intramolecular interaction. Such proline‐induced fragmentation occurring readily in the source differed from the literature data on the specific behavior of proline‐containing peptides where bond ruptures occur solely in dissociation conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Control of a thrust‐vectored flying wing: a receding horizon—LPV approach
Authors: Jadbabaie Ali , Hauser John 
Published: September 2002

AbstractThis paper deals with the application of receding horizon methods to hover and forward flight models of an experimental tethered flying wing developed at Caltech. The dynamics of the system are representative of a vertical landing and take off aircraft, such as a Harrier around hover, or a thrust‐vectored aircraft such as F18‐HARV or X‐31 in forward flight. The adopted control methodology is a hybrid of receding horizon techniques and control Lyapunov function (CLF)‐based ideas.First, a CLF is generated using quasi‐LPV methods and then, by using the CLF as the terminal cost in the receding horizon optimization, stability is guaranteed. The main advantage of this approach is that stability can be guaranteed without imposing constraints in the on‐line optimization, allowing the problem to be solved in a more efficient manner. Models of the experimental set‐up are obtained for the hover and forward flight modes. Numerical simulations for different time horizons are presented to illustrate the effectiveness of the discussed methods. Specifically, it is shown that a mere upper bound on the cost‐to‐go is not an appropriate choice for a terminal cost, when the horizon length is short. Simulation results are presented using experimentally verified model parameters. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical direct kinematic analysis of fully parallel linearly actuated platform type manipulators
Authors: Wang Li‐Chun T. , Oen Ka‐Tjun 
Published: September 2002

AbstractThis article presents a new numerical approach for solving the direct kinematics problem of fully parallel, linearly actuated platform manipulators. The solution procedure consists of two stages. The first stage transforms the direct kinematics problem into an equivalent nonlinear programming program, and a robust search algorithm is developed to bring the moving platform from arbitrary initial approximation to a feasible configuration that is near to the true solution. The second stage uses the Newton‐Raphson iterative method to converge the solution to the desired accuracy. This approach is numerically stable and computationally efficient. In addition, by randomly perturbing the initial approximations, it can be implemented successively to find multiple solutions to the direct kinematics problem. Two numerical examples are presented to demonstrate the stability and efficiency of this approach. © 2002 Wiley Periodicals, Inc.
Phase transition for Parking blocks, Brownian excursion and coalescence
Authors: Chassaing P. , Louchard G. 
Published: September 2002

AbstractIn this paper, we consider hashing with linear probing for a hashing table with m places, n items (n < m), and ℓ = m − n empty places. For a noncomputer science‐minded reader, we shall use the metaphore of n cars parking on m places: each car ci chooses a place pi at random, and if pi is occupied, ci tries successively pi + 1, pi + 2, until it finds an empty place. Pittel [42] proves that when ℓ/m goes to some positive limit β < 1, the size B of the largest block of consecutive cars satisfies 2(β − 1 − log β)B = 2 log m − 3 log log m + Ξm, where Ξm converges weakly to an extreme‐value distribution. In this paper we examine at which level for n a phase transition occurs between B = o(m) and m − B = o(m). The intermediate case reveals an interesting behavior of sizes of blocks, related to the standard additive coalescent in the same way as the sizes of connected components of the random graph are related to the multiplicative coalescent. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 76–119, 2002
The diameter of a long‐range percolation graph
Authors: Coppersmith Don , Gamarnik David , Sviridenko Maxim 
Published: September 2002

AbstractWe consider the following long‐range percolation model: an undirected graph with the node set {0, 1, … , N}d, has edges (x, y) selected with probability ≈ β/∥x − y∥s if ∥x − y∥ > 1, and with probability 1 if ∥x − y∥ = 1, for some parameters β, s > 0. This model was introduced by Benjamini and Berger [2], who obtained bounds on the diameter of this graph for the one‐dimensional case d = 1 and for various values of s, but left cases s = 1, 2 open. We show that, with high probability, the diameter of this graph is Θ(log N/log log N) when s = d, and, for some constants 0 < η1 < η2 < 1, it is at most N when s = 2d, and is at least N when d = 1, s = 2, β < 1 or when s > 2d. We also provide a simple proof that the diameter is at most logO(1) N with high probability, when d < s < 2d, established previously in [2]. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 21: 1–13, 2002
Support system for user interests expression on searching web pages
Authors: Sunayama Wataru , Nomura Yuji , Ohsawa Yukio , Yachida Masahiko 
Published: September 2002

AbstractAn Internet user who wants to know about a certain topic uses a search engine to find pages related to that topic. However, there are so many pages on the World Wide Web that the user cannot access the pages directly, because most search engines output URLs matching the exact words entered by the user. In addition, even though users use intelligent search techniques, it is difficult to input proper keywords because of lack knowledge or lapse of memory. This paper presents a Support System for User Interest Expression which supplies users with keywords, combining the user's interests with information on the WWW, making it possible to input search keywords concretely and precisely. © 2001 Scripta Technica, Syst Comp Jpn, 32(13): 14–22, 2001
A dynamic synchronization protocol and scheduling method based on Timestamp Ordering for real‐time transactions
Authors: Adaka Masanori , Okubo Eiji 
Published: September 2002

AbstractIn this article, we propose a dynamic synchronization protocol and a scheduling method based on Timestamp Ordering for real‐time transactions. First, we describe a synchronization protocol that avoids transaction abort by reserving shared resources accessed by transactions. This protocol does not incur unnecessary wait for resources, so it shows excellent performance under time constraint, compared with the priority ceiling protocol used in static scheduling environment. Next, we describe a dynamic scheduling method that takes into account both Timestamp Ordering and priority of transactions. This method does not incur deadlock unlike two‐phase locking, for example, and it can decrease violation of time constraint due to resource waiting. We compare the two proposed methods and other methods by simulation, and discuss the effectiveness of the proposed methods. © 2001 Scripta Technica, Syst Comp Jpn, 32(13): 61–70, 2001
A feature of 2D and 3D images invariant to similarity transformations based on the bispectrum
Authors: Horikawa Yo 
Published: September 2002

AbstractA novel feature of 2D and 3D patterns invariant to similarity transformations is derived from the bispectrum. The invariant feature is a histogram of triple products of frequency components and is calculated with the Fourier transform of original images. Computer experiments on sinusoidal patterns, 2D texture images, and 3D brain images show that the invariant feature is applicable to the classification of images shifted and rotated arbitrarily, scaled up to double size, and including additive noise up to 0 dB. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 1–10, 2002
Real‐time production system shell supporting persistent data
Authors: Nishiyama Satoshi , Ono Chihiro , Obana Sadao , Suzuki Kenji 
Published: September 2002

AbstractThe implementation and evaluation of a production system shell which can negotiate a large amount of data over a database and is capable of responding in real time to external changes such as alarms, from networks is discussed with the goal of applying it to expert systems in such fields as network management. The matching algorithm is obtained by extending the LEAPS matching algorithm, based on the highest priority search, by incorporating external changes into it in real time. In addition, data are stored persistently in a database and such persistent data can be used for inference by differentiating them from the nonpersistent data of the main memory. The evaluation results showed that external changes can be reflected in inference in real time, that inference with respect to the persistent data can be realized with a performance 1/10 to 1/50 of that in the case of nonpersistent data by matching, and that it is possible to achieve high‐speed processing, several times to several tens of times as fast as past inference methods which store data in widely used database management systems (DBMS) and perform inference by accessing the data by SQL and the like from the expert system. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 11–20, 2002
Evaluation of a data preload mechanism for a linked list structure
Authors: Yamamura Shuji , Kadota Tadafumi , Hirata Hiroaki , Niimi Haruo , Shibayama Kiyoshi 
Published: September 2002

AbstractThe authors have been developing a data preload/prefetch scheme for a linked list structure. In this paper, results of evaluating this preload scheme with benchmark programs requiring frequent pointer operations are reported. This scheme is characterized by the fact that the pointer value of a linked list is preloaded and stored, and a mechanism of providing the pointer value without delay for subsequent instructions is installed inside the processor. While dramatic performance improvement is expected by preloading/prefetching of a pointer value in this scheme, it is feared that a speculative execution using a preloaded pointer value before an update may fail if the linked list structure is modified, which may influence the performance negatively. However, it has been confirmed that in actual programs, such a failure of speculative execution does not occur, so that no performance problem arises. The evaluation results have confirmed a maximum performance improvement of 24.3% and the efficacy of the scheme. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 21–30, 2002
Styling and animating human hair
Authors: Kishi Keisuke , Morishima Shigeo 
Published: September 2002

AbstractSynthesizing facial images by computer graphics (CG) has attracted attention in connection with the current trends toward synthesizing virtual faces and realizing communication systems in cyberspace. In this paper, a method for representing human hair, which is known to be difficult to synthesize in computer graphics, is presented. In spite of the fact that hair is visually important in human facial imaging, it has frequently been replaced by simple curved surfaces or a part of the background. Although the methods of representing hair by mapping techniques have achieved results, such methods are inappropriate in representing motions of hair. Thus, spatial curves are used to represent hair, without using textures or polygons. In addition, hair style design is simplified by modeling hair in units of tufts, which are partially concentrated areas of hair. This paper describes the collision decisions and motion representations in this new hair style design system, the modeling of tufts, the rendering method, and the four‐branch (quadtree) method. In addition, hair design using this hair style design system and the animation of wind‐blown hair are illustrated. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 31–40, 2002
Response of a pacemaker neuron model to transient pulse trains
Authors: Yamanobe Takanobu , Nomura Taishin , Pakdaman Khashayar , Sato Shunsuke 
Published: September 2002

AbstractIn this study, the response of the pacemaker neuron model to transient pulse inputs (input sequence composed of a finite number of pulses with interval variations) is examined. The shift of the firing phase of the pacemaker neuron generated by a single pulse stimulus is represented by the phase transition curve. The dynamics of the pacemaker neuron receiving pacemaker pulse stimuli has been analyzed in terms of the one‐dimensional discrete dynamical system derived from the phase transition curve. This paper shows that the dynamics of the model for the transient pulse input can be described by a finite set of phase transition curves. The constructed pacemaker neuron model can reproduce the response of the slowly adapting stretch receptor organ (SAO) of the crayfish to the transient pulse inputs observed in the experiment. It is observed in the experiment that the qualitative property of the response pattern of the SAO to the transient pulse inputs changes suddenly while the input is applied. In order to analyze the generation mechanism underlying the response to the transient pulse inputs, the response of the model is analyzed in detail for inputs with increasing rate, that is, pulse input trains in which the inverse of the input pulse interval monotonically increases. In particular, the mechanism of generation of the paradoxical response, in which the output rate increases monotonously in response to the inhibitory input with increasing rate, is described. © 2002 Scripta Technica, Syst Comp Jpn, 33(3): 63–73, 2002
Meshing technology with quality assurance for curved surfaces defined by linear Lie algebra
Authors: Kawano Shin‐ichi , Makino Mitsunori , Ishii Shinya , Chao Jinhui 
Published: September 2002

AbstractA high‐quality triangular meshing is proposed for surfaces defined by linear Lie algebra. It is known that linear Lie algebra can define a variety of surfaces including a certain type of nonalgebraic surfaces as well as algebraic ones. Therefore, it is also applicable to the field of computer vision. However, in a case of visualizing efficiently such surfaces by computer graphics, an adaptive approximation of the surfaces is necessary. In this paper, by considering fluctuation of the normal vector in the neighborhood of an obtained point on the surface, an adaptive meshing algorithm is presented, which holds high‐quality approximation of the object. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(10): 64–73, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1158