bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antimicrobial activity of some Pacific Northwest woods against anaerobic bacteria and yeast
Authors: Johnston W. H. , Karchesy J. J. , Constantine G. H. , Craig A. M. 
Published: August 2002

AbstractExtracts of woods commonly used for animal bedding were tested for antimicrobial activity. Essential oils from Alaska cedar (Chamaecyparis nootkatensis), western juniper (Juniperus occidentalis) and old growth Douglas fir (Pseudotsuga menziesii) as well as methanol extracts of wood from these trees plus western red cedar (Thuja plicata) and ponderosa pine (Pinus ponderosa) were tested for antimicrobial activity against anaerobic bacteria and yeast. The test microbes included Fusobacterium necrophorum, Clostridium perfringens, Actinomyces bovis and Candida albicans which are common to foot diseases and other infections in animals. The essential oils and methanol extracts were tested using a standardized broth assay. Only extracts of Alaska cedar and western juniper showed significant antimicrobial activity against each of the microbes tested. The essential oil of Douglas fir did show antimicrobial activity against A. bovis at the concentrations tested. The methanol extracts of the heartwood of Douglas fir and the sapwood of ponderosa pine showed no antimicrobial activity. The major chemical components of western juniper (cedrol and α‐ and β‐cedrene) and Alaska cedar (nootkatin) were also tested. In western juniper, α‐ and β‐cedrene were found to be active components. Nootkatin showed activity only against C. albicans. The inhibitory activity in Alaska cedar oil was high enough to justify further efforts to define the other chemical components responsible for the antimicrobial activity. Copyright © 2001 John Wiley & Sons, Ltd.
Antiviral activities of extracts isolated from Terminalis chebula retz., Sanguisorba officinalis L., Rubus coreanus miq. and Rheum palmatum L. against hepatitis B virus
Authors: Kim Tae Gyun , Kang Seog Youn , Jung Ki Kyung , Kang Ju Hye , Lee Euna , Han Hyung Mee , Kim Seung Hee 
Published: August 2002

AbstractThe antiviral effects of aqueous extracts of Terminalis chebula Retz., Sanguisorba officinalis L., Rubus coreanus Miq. and Rheum palmatum L. were examined by a cell culture system using a hepatitis B virus (HBV) producing cell line, HepG2 2.2.15. The extracts were assayed for the inhibition of HBV multiplication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells after an 8‐day treatment. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to 128 μg/mL and inhibited the secretion of HBsAg dose dependently. Of the four tested plants, Terminalis chebula exhibited the most prominent anti‐HBV activities. Copyright © 2001 John Wiley & Sons, Ltd.
Promising hypotensive effect of hawthorn extract: A randomized double‐blind pilot study of mild, essential hypertension
Authors: Walker Ann F. , Marakis Georgios , Morris Andrew P. , Robinson Paul A. 
Published: August 2002

AbstractThis pilot study was aimed at investigating the hypotensive potential of hawthorn extract and magnesium dietary supplements individually and in combination, compared with a placebo. Thirty‐six mildly hypertensive subjects completed the study. At baseline, anthropometric and dietary assessment, as well as blood pressure measurements were taken at rest, after exercise and after a computer ‘stress’ test. Volunteers were then randomly assigned to a daily supplement for 10 weeks of either: (a) 600 mg Mg, (b) 500 mg hawthorn extract, (c) a combination of (a) and (b), (d) placebo. Measurements were repeated at 5 and 10 weeks of intervention. There was a decline in both systolic and diastolic blood pressure in all treatment groups, including placebo, but ANOVA provided no evidence of difference between treatments. However, factorial contrast analysis in ANOVA showed a promising reduction (p = 0.081) in the resting diastolic blood pressure at week 10 in the 19 subjects who were assigned to the hawthorn extract, compared with the other groups. Furthermore, a trend towards a reduction in anxiety (p = 0.094) was also observed in those taking hawthorn compared with the other groups. These findings warrant further study, particularly in view of the low dose of hawthorn extract used. Copyright © 2002 John Wiley & Sons, Ltd.
Reliability evaluation for linear consecutively‐connected systems with multistate elements and retransmission delays
Authors: Levitin Gregory 
Published: August 2002

AbstractA linear consecutively‐connected system consists of N linear ordered positions at which statistically‐independent multistate elements with different characteristics are allocated. Each element can provide propagation of a signal it receives from the previous positions to the next few positions. Each element can have different states determined by a number of adjacent nodes receiving the signal directly from this element. The signal retransmission process is associated with delays. The system fails if the signal generated at the first position (source) cannot reach the Nth position (receiver) within a specified time. An algorithm based on the universal generating function method is presented in this paper for determination of reliability of the linear consecutively‐connected system with delays. Copyright © 2001 John Wiley & Sons, Ltd.
Weighted least‐squares estimation of the shape parameter of the Weibull distribution
Authors: Hung Wen‐Liang 
Published: August 2002

AbstractThe purpose of this paper is to propose the weighted least‐squares procedure for estimating the shape parameter of the Weibull distribution. Results from simulation studies illustrate the mean‐squared error of the weighted least‐squares estimator is smaller than competing procedures in all cases considered. Copyright © 2001 John Wiley & Sons, Ltd.
Liquid chromatography ion trap mass spectrometric analysis of oligosaccharides using permethylated derivatives
Authors: Delaney Jeannine , Vouros Paul 
Published: August 2002

AbstractReversed phase liquid chromatography was combined with the multiple stage mass analysis capability of an ion trap mass spectrometer for the characterization of permethylated oligosaccharide mixtures. The new method was used to separate the components of an unlabeled permethylated maltooligomer ladder, a 2‐aminobenzamide‐labeled (2‐AB) maltooligomer ladder, a complex mixture of 2AB‐labeled bi‐ (B), tri‐ (T), and tetraantennary (Q) standards, and a mixture of recombinant glycoprotein carbohydrates from soluble CD4 with varying sialic acid (S) content. Using reversed phase HPLC, permethylated mixture components including α and β anomers were separated based on their structures. Fluorescent labeling with 2‐aminobenzamide prior to permethylation was employed for off‐line method development, but was not necessarily required for mass spectral analysis, as permethylation alone improved the ionization and fragmentation characteristics of the molecules. Antennae composition of permethylated derivatives was determined in MS2 where the fragmentation patterns of the Y‐ and B‐ion series predominated, and then further evaluated in MS3, which provided additional information on branching obtained from A and X cross‐ring fragmentation. Copyright © 2001 John Wiley & Sons, Ltd.
m/z‐Selective infrared multiphoton dissociation in a Penning trap using sidekick trapping and an rf‐tickle pulse
Authors: Hofstadler Steven A. , Sannes‐Lowery Kristin A. , Griffey Richard H. 
Published: August 2002

AbstractWe present a novel scheme for performing m/z‐selective infrared multiphoton dissociation (IRMPD) in a Penning trap. Ions are injected into the trapped ion cell of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer and trapped using the ‘sidekick’ approach. Because this mode of ion trapping can result in an ion cloud precessing about the central axis of the cell with a significant magnetron radius, the effectiveness of conventional on‐axis IRMPD schemes can be adversely affected. Here we demonstrate that the non‐zero magnetron radius of the ion ensemble can be exploited with rf‐tickle pulses which excite, either in an m/z‐selective or broadband mode, the cyclotron frequency of the orbiting ions such that their flight path intercepts the on‐axis laser beam resulting in effective IRMPD. This approach has potential utility in the tandem mass spectrometric characterization of complex mixtures, suggests new approaches for two‐dimensional FTICR studies and, most importantly, represents a straightforward approach to improve the effectiveness of IRMPD for ions captured using sidekick trapping protocols. Copyright © 2001 John Wiley & Sons, Ltd.
Improved thermal decomposition of sulfates to SO2 and mass spectrometric determination of δ34S of IAEA SO‐5, IAEA SO‐6 and NBS‐127 sulfate standards
Authors: Halas Stanislaw , Szaran Janina 
Published: August 2002

AbstractWe describe a significant improvement to our low‐temperature thermal decomposition of sulfates to SO2 for isotopic analysis (Halas S, Szaran J. Anal. Chem. 1999; 71: 3254) that has led to better reproducibility and efficiency of measurements. In the present approach we use a mixture of two reagents, NaPO3 + V2O5, mixed in a weight ratio of 3:5. The addition of V2O5 prevents overboiling of NaPO3 at temperatures, T, increased to 800 °C. Using this modified method we obtained the following δ34S values (in ‰): +21.17 ± 0.12 for NBS‐127, +0.15 ± 0.06 for IAEA SO‐5, and −34.12 ± 0.11 for IAEA SO‐6. Copyright © 2001 John Wiley & Sons, Ltd.
Phytoremediation of arsenic‐contaminated soil as affected by the chelating agent CDTA and different levels of soil pH
Authors: Bagga Davinderjit K. , Peterson Scott 
Published: August 2002

AbstractElevated levels of arsenic can pose a major threat to both human health and the environment. The
phytoremediation of heavy metals from soil is emerging as a cost‐effective technology for the
remediation of contaminated soils. The present greenhouse study was undertaken to identify plants capable of
tolerating and accumulating high concentrations of arsenic. Asparagus fern and rye grass were found to tolerate
and accumulate more than 1,100 ppm of arsenic in plant tissue. Arsenic uptake as affected by different levels
of the chelating agent trans‐1, 2‐ cyclohexylenedinitrilotetraacetic acid (CDTA) and
soil pH were also studied. The application of 5 mmol kg−1 of CDTA to
arsenic‐contaminated medium loam field soil enhanced the accumulation of arsenic by the test plants.
Under these conditions, plants accumulated up to 1,400 ppm of arsenic as compared to 950 ppm by the plants
grown in soil containing 1,200 ppm of arsenic but without any amendment of the chelating agent. Plants grown in
field soil of pH 5 containing 300 ppm of arsenic absorbed higher concentrations of arsenic than at other tested
pH levels. Corresponding reductions in arsenic content of soil after plant harvests were observed. © 2001
John Wiley & Sons, Inc.
Human herpesvirus‐6 and ‐7 in transplantation
Authors: Dockrell David H. , Paya Carlos V. 
Published: August 2002

AbstractInfections with the β‐herpesviruses human herpesvirus‐6 (HHV‐6) and human herpesvirus‐7 (HHV‐7) are ubiquitous in childhood. The immunosuppression secondary to organ or bone marrow transplantation together with posttransplantation management may favour viral replication and reactivation. HHV‐6 and ‐7 induce immunosuppression by targeting lymphocytes, natural killer cells and monocytes. HHV‐6 is commonly detected posttransplantation but variability in definitions of clinical syndromes related to this virus and detection methods have complicated understanding of the clinical relevance of HHV‐6 posttransplantation. Clinical symptoms associated with HHV‐6 include febrile illness, pneumonitis, hepatitis, encephalitis and bone marrow suppression. However, the majority of HHV‐6 infections are asymptomatic. The incidence of HHV‐7 infection and its clinical manifestations posttransplantation are even less well characterised. In addition, HHV‐6 and HHV‐7 are related to CMV disease or acute graft‐versus‐host disease and, indirectly, to increases in resource utilisation. Based on the potential relevance of these two β‐herpesviruses in transplant recipients, further studies are required to establish their real impact in transplantation. For this, sensitive and specific molecular diagnostic techniques allowing for the rapid detection and quantitation of virus and for the analysis of susceptibility to current antiviral agents are required. Copyright © 2001 John Wiley & Sons, Ltd.
RobustH∞control of phase‐locked loops with polytopic type uncertainties
Authors: Suplin V. , Shaked U. 
Published: August 2002

AbstractA robustH∞control method is applied in the design of loop filters for phase‐locked loop (PLL) carrier phase tracking. The proposed method successfully copes with large S‐curve slope uncertainty and with a significant decision delay in the closed loop that may stem from the decoder and/or the equalizer there. The design problem is transformed into a state‐feedback control problem where phase and gain margins should be guaranteed in spite of the uncertainty. Of all the loop filters that achieve the required margins the one that minimizes an upper bound on the effect of the phase and the measurement noise signals is derived. Copyright © 2001 John Wiley & Sons, Ltd.
H∞control for nonlinear affine systems: a chain‐scattering matrix description approach
Authors: Hong Jang‐Lee , Teng Ching‐Cheng 
Published: August 2002

AbstractThis paper combines an alternative chain‐scattering matrix description with (J,J′)‐lossless and a class of conjugate (−J, −J′)‐lossless systems to design a family of nonlinearH∞output feedback controllers. The present systems introduce a new chain‐scattering setting, which not only offers a clearer expression for the solving process of the nonlinearH∞control problem but also removes the fictitious signals introduced by the traditional chain‐scattering approach. The intricate nonlinear affine control problem thus can be transformed into a simple lossless network and is easy to deal with in a network‐theory context. The relationship among these (J,J′) systems,L2‐gain, and Hamilton–Jacobi equations is also given. Block diagrams are used to illustrate the central theme. Copyright © 2001 John Wiley & Sons, Ltd.
Linear matrix inequality conditions for robustness and control design
Authors: D'Andrea Raffaello 
Published: August 2002

AbstractIn this paper, well‐known stability conditions for linear, time‐invariant systems subject to structured uncertainty are extended to encompass matrix valued and affine integral constraints on the system inputs and outputs. Necessary and sufficient analysis conditions are derived in terms of linear matrix inequalities. For a large class of these problems, the synthesis question can also be expressed as a linear matrix inequality. Copyright © 2001 John Wiley & Sons, Ltd.
Discrete‐time low‐gain control of linear systems with input/output nonlinearities
Authors: Fliegner T. , Logemann H. , Ryan E. P. 
Published: August 2002

AbstractDiscrete‐time low‐gain control strategies are presented for tracking of constant reference signals for finite‐dimensional, discrete‐time, power‐stable, single‐input, single‐output, linear systems subject to a globally Lipschitz, non‐decreasing input nonlinearity and a locally Lipschitz, non‐decreasing, affinely sector‐bounded output nonlinearity (the conditions on the output nonlinearities may be relaxed if the input nonlinearity is bounded). Both non‐adaptive and adaptive gain sequences are considered. In particular, it is shown that applying error feedback using a discrete‐time ‘integral’ controller ensures asymptotic tracking of constant reference signals, provided that (a) the steady‐state gain of the linear part of the plant is positive, (b) the positive gain sequence is ultimately sufficiently small and (c) the reference value is feasible in a very natural sense. The classes of input and output nonlinearities under consideration contain standard nonlinearities important in control engineering such as saturation and deadzone. The discrete‐time results are applied in the development of sampled‐data low‐gain control strategies for finite‐dimensional, continuous‐ time, exponentially stable, linear systems with input and output nonlinearities. Copyright © 2001 John Wiley & Sons, Ltd.
Forward decomposition algorithms for optimal control of a class of hybrid systems
Authors: Cho Young C. , Cassandras Christos G. , Pepyne David L. 
Published: August 2002

AbstractThis paper considers optimal control problems for a class of hybrid systems motivated by the structure of manufacturing environments that integrate process and operations control. We derive new necessary and sufficient conditions that allow us to determine the structure of the optimal sample path and hence decompose a large non‐convex, non‐differentiable problem into a set of smaller convex, constrained optimization problems. Using these conditions, we develop two efficient, low‐complexity, scalable algorithms for explicitly determining the optimal controls. Several numerical examples are included to illustrate the efficacy of the proposed algorithms. Copyright © 2001 John Wiley & Sons, Ltd.
GuaranteedH∞robustness bounds for Wiener filtering and prediction
Authors: Bolzern P. , Colaneri P. , De Nicolao G. , Shaked U. 
Published: August 2002

AbstractThe paper deals with special classes ofH∞estimation problems, where the signal to be estimated coincides with the uncorrupted measured output. Explicit bounds on the difference between nominal and actualH∞performance are obtained by means of elementary algebraic manipulations. These bounds are new in continuous‐time filtering and discrete‐time one‐step ahead prediction. As for discrete‐time filtering, the paper provides new proofs that are alternative to existing derivations based on the Krein spaces formalism. In particular, some remarkableH∞robustness properties of Kalman filters and predictors are highlighted. The usefulness of these results for improving the estimator design under a mixedH2/H∞viewpoint is also discussed. The dualization of the analysis allows one to evaluate guaranteedH∞robustness bounds for state‐feedback regulators of systems affected by actuator disturbances. Copyright © 2001 John Wiley & Sons, Ltd.
An efficient algorithm for computing object poses in a modular fixture or gripper
Authors: Qian Wen‐Han , Qiao Hong 
Published: August 2002

AbstractModular or reconfigurable fixtures (or grippers) can reduce manufacturing costs and time remarkably. Computing the poses of a given object in a modular fixture is a basic but tedious technique for designing and using such fixtures. This article presents an efficient algorithm for computing the poses. Starting from a unified expression of the outline of an object, this algorithm searches all matching poses automatically. If the outline consists of straight lines and circular arcs only, all the unknown variables can be calculated sequentially by substituting known (or tentative) data in respective expressions, without solving complicated simultaneous equations. When applied to arbitrary outlines, it involves nothing more than common interpolation. The search process is visualized through diagrams that clearly display the occurrence of matching poses. The computer programs are universally applicable. Only the data of the object outline and the fixture configuration need be input. Case studies show that the programs run fast and yield accurate results. © 2002 Wiley Periodicals, Inc.
Three‐dimensional localization of thin‐walled sheet metal parts for robotic assembly
Authors: Park Edward J. , Mills James K. 
Published: August 2002

AbstractThis article presents a technical demonstration of a system for determining the three‐dimensional spatial location of complexly shaped, thin‐walled sheet metal parts grasped by robots during assembly. For successful part assembly, the precise location of grasped parts (essential for successful mating of parts) must be achieved. A localization system is implemented to determine the accurate position and orientation of a sheet metal part that has been picked up by a robot from an arbitrary location. The proposed localization system employs a novel sensing method, utilizing laser‐based proximity and edge detectors, to extract the part feature data in real time. These geometrical feature data are incorporated into an existing localization algorithm, which is based on the singular value decomposition formulation of the part localization problem. The sensing method is particularly effective in measuring 3‐D feature geometry (i.e., thin edges) of sheet metal parts. An experimental single‐robot test bed has been developed to demonstrate the feasibility of the part localization concept for a single sheet metal part. The experimental results obtained from the test bed demonstrate that the system can be effectively used for the localization of thin‐walled sheet metal parts. © 2002 Wiley Periodicals, Inc.
On singular behaviors of impedance‐based repeatable control for redundant robots
Authors: Wang Chau‐Chang , Kumar Vijay 
Published: August 2002

AbstractThis article addresses the association between the unstiffening phenomena in structural mechanics and the algorithmic singularities encountered in the impedance‐based repeatable control algorithms used to command redundant manipulators. It is well known that velocity control schemes such as the pseudoinverse control schemes do not guarantee repeatability for redundant manipulators. In other words, for a closed end‐effector trajectory, the joints do not, in general, exhibit a closed trajectory. One way to overcome this problem is to model each joint with compliance and incorporate a second‐order correction term for the pseudoinverse. With this model, the joint configuration adopted by the manipulator at a given point in task space is one which minimizes the artificial potential energy of the system and is locally unique. In terms of statics, this is equivalent to saying that the elastic structure reaches its static equilibrium under external load. Keep this analogy in mind. We know that the impedance control commands the manipulator to mimic the behavior of an elastic articulated chain. For any phenomena observable on a real elastic structure, we should be able to find its counterpart embedded in the impedance control. In this article, we analyze the performance of such repeatable control algorithms from the point of view of structure mechanics. Singularities in the algorithm are examined and their significance in mechanics are also discussed. © 2001 John Wiley & Sons, Inc.
A discrete event approach to the command sequence replanning and control in a teleprogramming system
Authors: Cho Young‐Jo , Akella Prasad , Kotoku Tetsuo , Tanie Kazuo 
Published: August 2002

AbstractA command sequence replanning and control method, which enables the slave system to autonomously recover from error conditions, is proposed in a telerobot system. A task model described as a form of the controlled Petri net (CPN) is used as a prior knowledge for the slave system to carry out the given task successfully without the operator's aid even in unexpected error conditions. The CPN model incorporates the contact states and transitional motions between them that possibly exist in the task execution process. The motion command is automatically generated from the master system and transmitted to the slave whenever the contact state changes in the master model. Referring to the CPN model and the given motion commands, the slave system detects if the actual contact state is unexpected and then plans the recovery path from the unexpected state. The feasibility of the command sequence replanning and control algorithm is verified through an example to perform a simple part‐mating task. © 2001 John Wiley & Sons, Inc.