bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subdomains in the F and G helices of bacteriorhodopsin regulate the conformational transitions of the reprotonation mechanism
Authors: Martinez Lynell C. , Thurmond Robin L. , Jones Philip G. , Turner George J. 
Published: October 2002

AbstractWe have performed cysteine scanning mutagenesis of the bacteriorhodopsin mutant D85N to explore the role of individual amino acids in the conformational transitions of the reprotonation mechanism. We have used whole‐cell reflectance spectroscopy to evaluate the spectral properties of the 59 mutants generated during a scan of the entire F and G helices and the intervening loop region. Cys mutants were grouped into one of six phenotypes based on the spectral changes associated with their M ↔ N ↔ O intermediate‐state transitions. Mutations that produced similar phenotypes were found to cluster in discrete molecular domains and indicate that M, N, and O possess distinct structures and that unique molecular interactions regulate the transitions between them. The distribution of these domains suggests that 1) the extramembranous loop region is involved in the stabilization of the N and M intermediates, 2) lipid‐protein interactions play a key role in the accumulation of N, and 3) the amino acid side‐chain interactions in the extracellular portion of the interface between helices G and A participate in the accumulation of M. Proteins 2002;48:269–282. © 2002 Wiley‐Liss, Inc.
Protein domain identification and improved sequence similarity searching using PSI‐BLAST
Authors: George Richard A. , Heringa Jaap 
Published: October 2002

AbstractProtein sequences containing more than one structural domain are problematic when used in homology searches where they can either stop an iterative database search prematurely or cause an explosion of a search to common domains. We describe a method, DOMAINATION, that infers domains and their boundaries in a query sequence from local gapped alignments generated using PSI‐BLAST. Through a new technique to recognize domain insertions and permutations, DOMAINATION submits delineated domains as successive database queries in further iterative steps. Assessed over a set of 452 multidomain proteins, the method predicts structural domain boundaries with an overall accuracy of 50% and improves finding distant homologies by 14% compared with PSI‐BLAST. DOMAINATION is available as a web based tool at http://mathbio.nimr.mrc.ac.uk, and the source code is available from the authors upon request. Proteins 2002;48:672–681. © 2002 Wiley‐Liss, Inc.
Numerical simulation of permeation through vacuum‐coated laminate films
Authors: Mueller K. , Weisser H. 
Published: October 2002

AbstractThe material usage in the packaging market of Germany has decreased over the last few years. This trend results from the substitution of heavy packages with light‐weight, flexible materials. In this context, aluminium foil‐based multilayer films have been partly replaced by metallized laminates in food packaging technology. Other coating materials, such as Al2O3 or SiOx, are used where transparent films are desired. The disadvantage of these vacuum‐coated layers is the existence of pinholes which allow diffusion processes, in contrast to aluminium foil‐based multilayer films. In this study the barrier behaviour of vacuum coated laminate films was predicted by numerical simulation. The results are presented in terms of dimensionless parameters so that they may be transferred to analogous problems. This model provides a method to calculate the oxygen permeation through coated laminates. However, it is invalid for condensable gases such as water vapour. The simulation is suited for characterizing the influence of the compound structure on the barrier properties of vacuum coated laminate films. The results are verified by comparing the calculated with measured values. Copyright © 2002 John Wiley & Sons, Ltd.
First‐order versus high‐order stochastic models for computer intrusion detection
Authors: Ye Nong , Ehiabor Timothy , Zhang Yebin 
Published: October 2002

AbstractThis paper presents two different methods of applying stochastic models to computer intrusion detection. One method is based on a first‐order stochastic model, specifically a Markov chain model. The other method is based on a partial high‐order stochastic model. Stochastic models are used to build a profile of normal activities on a computer from the training data of normal activities on the computer. The norm profile is then used to detect anomalous activities from testing data of both normal and intrusive activities on the computer for intrusion detection. Audit data of computer activities contain a sequence of computer events that is represented as a series of event transitions in stochastic models. The comparison of detection performance between the Markov chain model application and the partial high‐order stochastic model application reveals the better detection performance of the Markov chain model application to computer intrusion detection. Copyright © 2002 John Wiley & Sons, Ltd.
Is the Pauli exclusive principle an independent quantum mechanical postulate?
Authors: Kaplan I. G. 
Published: October 2002

AbstractFoundation of the Pauli exclusive principle is discussed. It is demonstrated that the indistinguishability principle is insensitive to the permutation symmetry of the wave function and cannot be used as a criterion for the verification of the Pauli exclusive principle. The heuristic arguments are given in favor that the existence in nature of only the nondegenerate permutation representations (symmetrical and antisymmetrical) is not occasional. As follows from our analysis of possible scenarios, the permission of degenerate permutation representations leads to contradictions with the concept of particle identity and their independence. Thus, the prohibition of degenerate permutation states by the Pauli exclusive principle follows from the general physical assumptions inside quantum theory, but the problem of spin–statistics connection is still open. It is pointed out that the Pauli exclusive principle and the Jahn–Teller effect have some similar features. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Calculated geometries and charge distributions of 4n and 4n + 2 π‐ring systems linked with −CH: An asymmetric versus symmetric π‐delocalization
Authors: Buck Henk 
Published: October 2002

AbstractWith the assistance of quantum chemical calculations we discussed the geometrical and charge density differences between [4n]CH and [4n + 2]CH cations for [4n] and [4n + 2] π cyclic‐membered rings substituted with a CH group. In the case of [4n] and [4n + 2] membered rings we are dealing with antiaromaticity and aromaticity, respectively, in the ring systems. The calculations were performed with the Hückel molecular orbital (HMO) description including a variable bond‐length–dependent resonance integral. Furthermore, the HMO method was used with (limited) configuration interaction (CI) in combination with a valence bond (VB) formalism. We focused on the symmetry of π delocalization with respect to the different kind of cations. A symmetrical π delocalization was found for the [4n + 2] CH cations and an asymmetrical π delocalization for the [4n]CH cations. Via introduction of top symmetry cations as, for example, in [4n](CH)4n then the degeneracy of the highest‐occupied molecular orbitals (HOMOs) leads to symmetry lowering from D4nh into D2nh accompanied by alternating symmetrically localized π structures. As an example, the [4](CH)4 cation is given. In both cases, as the result of a Jahn–Teller distortion, the original geometry (D2h) and π contribution of the four‐membered ring is maintained. Several cations derived from the [4n] and [4n + 2] membered rings obtained by specific regio substitution of CH groups have been studied. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Spiking structure of amplitude characteristics for ion trajectories in hyperboloidal mass spectrometers: the theory
Authors: Sheretov Ernst P. , Philippov Igor V. , Karnav Tatiana B. , Kolotilin Boris I. , Ivanov Vladimir W. 
Published: October 2002

AbstractWe present a theory that describes a ‘spiking’ structure of the amplitude characteristics for trajectories of ions within a hyperboloidal mass spectrometer (HMS) discovered and reported recently. This effect, as well as modulation parametric resonance, relates directly to a fine structure of the stability diagram for a HMS. A method of extremum characteristic solutions of the Hill equation (developed in our laboratory earlier) has been used in this work. Simple expressions determined the shape of narrow dips (or reversed peaks) in the amplitude of ion oscillation versus stability parameter curves and conditions of their appearance are presented. The results that were calculated from analytical expressions are compared with those obtained from direct computations of ion trajectories in a HMS. This effect with respect to a nature of ‘black holes’ or ‘black canyons’ observed earlier in investigations of trapping efficiency and ion trapping within ion traps is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
The Use of Natural Systems to Remediate Groundwater: Department of Energy Experience at the Savannah River Site
Authors: Blount Gerald C. , Caldwell Cathleen C. , Cardoso‐Neto Joao E. , Conner Karen R. , Jannik G. T. , Murphy Charles E. , Noffsinger David C. , Ross Jeff A. 
Published: October 2002

AbstractNatural remediation is moving toward the forefront as engineers clean groundwater at the Savannah River Site
(SRS), a major Department of Energy (DOE) installation near Aiken, South Carolina. This
article reviews two successful, innovative remediation methods currently being deployed: biosparging to treat
chlorinated solvents and phytoremediation to address tritium in groundwater. The biosparging system reintroduces
oxygen into the groundwater and injects nutrient compounds for in‐situ remediation. The system has
greatly reduced the concentrations of trichloroethylene (TCE) and vinyl chloride in wells downgradient
from a sanitary landfill (SLF). Phytoremediation is an emerging technology that promises effective and
inexpensive cleanup of certain hazardous wastes. Using natural processes, plants can break down, trap and hold,
or transpire contaminants. This article discusses the use of phytoremediation to reduce the discharge of tritium
to an on‐site stream at SRS. © 2002 Wiley Periodicals Inc.*
OptimalH∞scaling for sensitivity optimization of detection filters
Authors: Edelmayer A. , Bokor J. 
Published: October 2002

AbstractThe paper deals with the sensitivity optimization of detection filters in linear time‐varying (LTV) systems which are subject to multiple simultaneous faults and disturbances. The robust fault detection filter design problem as ascaledH∞filtering problem is considered. The effect of two different input scaling approaches to the optimization process is investigated. The objective is to provide the smallest scaledL2gain of the unknown input of the system that is guaranteed to be less than a prespecified level, i.e., to produce a filter with optimal disturbance suppression capability in such a way that sufficient sensitivity to failure modes should still be maintained. It is shown how to obtain bounds on the scaledL2gain by transforming the standardH∞filtering problem into a convex feasibility problem, specifically, a structured, linear matrix inequality (LMI). Numerical examples demonstrating the effect of the scaled optimization with respect to conventionalH∞filtering is presented. Copyright © 2002 John Wiley & Sons, Ltd.
Dexterous manipulation of an object by means of multi‐DOF robotic fingers with soft tips
Authors: Nguyen Pham Thuc Anh , Arimoto Suguru 
Published: October 2002

AbstractThis article analyzes the dynamics of motion of various setups of two multiple degree‐of‐freedom (DOF) fingers that have soft tips, in fine manipulation of an object, and shows performances of their motions via computer simulation. A mathematical model of these dynamics is described as a system of nonlinear differential equations expressing motion of the overall fingers‐object system together with algebraic constraints due to tight area contacts between the finger‐tips and surfaces of the object. First, problems of (1) dynamic, stable grasping and (2) regulation of the object rotational angle by means of a setup of dual two‐DOF fingers, are treated. Second, the problem of regulating the position of the object mass center by means of a pair of two‐DOF and three‐DOF fingers is considered. Third, a set of dual three‐DOF fingers is treated, in order to let it perform a sophisticated task, which is specified by a periodic pattern of the object posture and a constant internal force. In any case, there exist sensory‐motor coordinations, which are described by analytic feedback connections from sensing to actions at finger joints. In the cases of setpoint control problems, convergences of motion to secure grasping together with the specified object rotational angle and/or the specified object mass center position, are proved theoretically. A constraint stabilization method (CSM) is used for solving numerically the differential algebraic equations to show performances of the proposed sensory‐feedback schemes. © 2002 Wiley Periodicals, Inc.
Super high definition image (WHD: Wide/Double HD) transmission system
Authors: Tanaka Kenji , Suzuki Kenji , Sato Masahito , Arakawa Yoshiki 
Published: October 2002

AbstractThis paper describes a WHD image transmission system constructed from a display projector, CODECs, and a camera system imaging a super high definition image (WHD: Wide/Double HD) corresponding to two screen portions of common high‐vision images. This system was developed as a transmission system to communicate with or transmit information giving a reality‐enhanced feeling to a remote location by using images of super high definition. In addition, the correction processing for the distortions of images occurring due to the structure of the camera system, an outline of the transmission experiments using the proposed system, and subjective evaluation experiments using WHD images are presented. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(9): 41–49, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10063
Optimization of requantization parameter for MPEG transcoding
Authors: Kadono Shinya , Etoh Minoru , Yokoya Naokazu 
Published: October 2002

AbstractThis paper considers transcoding in which an MPEG stream is converted to a low‐bit‐rate MPEG stream, and proposes a method in which the transcoding error can be reduced by optimally selecting the quantization parameter for each macroblock. In transcoding with a low compression ratio, it is crucial to prohibit transcoding with a requantization parameter which is 1 to 2 times the quantization parameter of the input stream. Consequently, as the first step, an optimization method for the requantization parameter is proposed which cares for the error propagation effect by interframe prediction. Then, the proposed optimization method is extended so that the method can also be applied to the case of a high compression ratio in which the rate—distortion curve is approximated for each macroblock in the range of requantization parameters larger than 2 times the quantization parameter. It is verified by a simulation experiment that the PSNR is improved by 0.5 to 0.8 dB compared to the case in which a 6 Mbit/s MPEG stream is not optimized by twofold recompression. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(9): 21–30, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10096
An intelligent information gathering method for dynamic information mediators
Authors: Kitamura Yasuhiko , Noda Tomoya , Tatsumi Shoji 
Published: October 2002

AbstractThe Internet is spreading into our society rapidly and is becoming one of the information infrastructures that are indispensable for our daily life. In particular, the WWW is widely used for various purposes such as sharing personal information, academic research, business work, and electronic commerce, and the amount of available information is increasing rapidly. We usually utilize information sources on the Internet as individual stand‐alone sources, but if we can integrate them, we can add more value to each of them. Hence, information mediators, which integrate information distributed on the Internet, are drawing attention. In this paper, under the assumption that the information sources to be integrated are updated frequently and asynchronously, we propose an information gathering method that constructs an answer to a query from a user, accessing information sources to be integrated properly within an allowable time period. The proposed method considers the reliability of data in the cache and the quality of answer in order to efficiently access information sources and to provide appropriate answers to the user. As evaluation, we show the effectiveness of the proposed method by using an artificial information integration problem, in which some parameters can be modified, and a real‐world flight information service compared with a conventional FIFO information gathering method. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(9): 11–20, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10119
Composition and decomposition learning of reaching movements under altered environments: An examination of the multiplicity of internal models
Authors: Nakano Eri , Flanagan John R. , Imamizu Hiroshi , Osu Rieko , Yoshioka Toshinori , Kawato Mitsuo 
Published: October 2002

AbstractWe have studied the learning processes of reaching movements under novel environments whose kinematic and dynamic properties are altered. In the experiments, we have used, as the kinematic transformation, a rotational transformation which is displayed by rotating a cursor indicating hand position in the orthogonal coordinate system on a CRT; a viscous transformation using viscous field as the dynamic transformation; and a combined transformation of these two transformations. It is observed that the hand trajectory approaches a straight line along with learning and accurately reaches the target. When the combined transformation is learned after the rotational transformation and viscous transformation are learned first, respectively, the final error becomes smaller and the path length also becomes shorter than the case when the combined transformation is learned first. Moreover, the final error and path length of the movement under rotational transformation and viscous transformation when the combined transformation is learned first also become smaller than the case when the rotational and viscous transformations are learned first. These results suggest that the central nervous system has learned separately the multiple internal models which compensate the respective transformations, and has composed or decomposed the respective internal models in accordance with the environmental changes. It may be considered that such multiplicity of internal models makes it possible for the living body to flexibly cope with the environments or tools having various dynamic and kinematic properties. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(11): 80–94, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1166
Prediction of the long‐term survival in breast cancer patients according to the present oncological status
Authors: Hatteville Laurence , Mahe Cédric , Hill Catherine 
Published: October 2002

AbstractAfter a breast cancer diagnosis, single or multiple events can occur during follow‐up (recurrence, metastasis, and death). An analysis of long‐term survival should take into account not only the initial characteristics of the patient, but also her oncological status (that is, her history) after surgery. For this purpose, we used a technique proposed by Klein, Keiding and Copelan (1994), to predict the probability of a patient being alive 20 years after surgery for a breast cancer, based on data concerning her oncological status at time t. The first step of the model was to estimate the hazard function for each event of interest (recurrence, metastasis, and death) in a Cox model including initial patient characteristics (age, tumour size, number of involved axillary lymph nodes and the Scarff, Bloom and Richardson (SBR) histo‐prognostic grade) and time‐dependent covariates representing the occurrence of intermediate events (recurrence and metastasis). The second step was to use these estimations to calculate the conditional probability of being alive 20‐tyears later for a patient, given her oncological status at timet(t<10 years). In this second step, the method presented by Klein, Keiding and Copelan was extended to include non‐proportional hazards. This model has been applied to a population of 3180 patients operated on for a breast cancer at the Institut Gustave Roussy between 1 January 1954 and 31 December 1983. At the time of surgery, the probability of survival at 20 years is 0.78 for all patients. Ten years after surgery, if no recurrence or metastasis are observed, the probability of survival at 20 years will rise to 0.89. If only a recurrence is observed, the probability of a patient being alive at 20 years will drop to 0.72. If a metastasis and no recurrence is observed, the probability of survival at 20 years will be only 0.18. If both recurrence and metastasis are observed the probability of survival at 20 years will be equal to 0.09. In conclusion, the model used dynamically appraises the prognosis and represents a new approach for studying the outcome of breast cancer patients having undergone surgery. Copyright © 2002 John Wiley & Sons, Ltd.
Periodograms and pulse detection methods for pulsatile hormone data
Authors: Grambsch Patricia , Meller William H. , Victor Grambsch P. 
Published: October 2002

AbstractPulse detection algorithms and spectral analysis are the two most common methods for analysing pulsatile hormone data. We compared a popular high quality pulse detection algorithm (CLUSTER) to spectral analysis on a data set comparing luteinizing hormone data in depressed and control women. For these data, periodogram analysis methods, in particular Fisher's periodicity test, were superior in distinguishing the groups. Extending the pulse detection method to include measures of intra‐individual variability improved its discriminatory performance. The two methods complement each other. Copyright © 2002 John Wiley & Sons, Ltd.
Using inverse weighting and predictive inference to estimate the effects of time‐varying treatments on the discrete‐time hazard
Authors: Dawson Ree , Lavori Philip W. 
Published: October 2002

AbstractWe estimate the effects of non‐randomized time‐varying treatments on the discrete‐time hazard, using inverse weighting. We consider the special monotone pattern of treatment that develops over time as subjects permanently discontinue an initial treatment, and assume that treatment selection is sequentially ignorable. We use a propensity score in the hazard model to reduce the potential for finite‐sample bias due to inverse weighting. When the number of subjects who discontinue treatment at any given time is small, we impose scientific restrictions on the potentially observable discontinuation hazards to improve efficiency. We use predictive inference to account for the correlation of the potential hazards, when comparing outcomes under different durations of initial treatment. Copyright © 2002 John Wiley & Sons, Ltd.