bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of environmental fluctuation on an eco‐epidemiological model of the Salton sea
Authors: Sarkar RamRup , Chattopadhayay J. , Bairagi N. 
Published: August 2002

AbstractElevated salinity, accelerated eutrophication, blooms of Avian botulism and dramatic water quality fluctuation are the key factors for massive die‐offs of Tilapias and pelicans in the Salton Sea. A stochastic model for infected Tilapias and their predator pelicans is proposed. The environmental parameters are perturbed by color noise characterized by Ornstein–Uhlenbeck process. The dynamical behavior of the system is studied by using the spectral density analysis and the solutions of the stochastic differential equations (SDE). A simple and transparent technique is given for finding the safe region in which the chance of pelican extinction is minimized. To substantiate the analytical results computer simulation is also performed for a hypothetical set of parameter values. Copyright © 2001 John Wiley & Sons, Ltd.
Measurement error reduction using weighted average method for repeated measurements from heterogeneous instruments
Authors: Xie Sharon X. , Liao Duanping , Chinchilli Vernon M. 
Published: August 2002

AbstractConsidering a situation in which observations are made by several instruments over time, researchers are interested in estimating the true quantity at a particular time point. Assuming observations made by different instruments at the same time point have the same time‐dependent mean but different variances, one approach is to estimate the true quantity or the time‐dependent mean by simply averaging the observations at a time point. However, since the variability of each instrument may be very different, the unweighted average can be improved by a weighted average with weights estimated from the longitudinal measurements produced by those instruments. Such a weighted average estimator is studied in this article. It is shown to be unbiased for the true quantity. Its variance is asymptotically smaller than that of any observation and also achieves the minimum variance among all the weighted estimates with known weights. The proposed method is illustrated by a real data example. The method is not restricted to the time‐dependent situation. The general setting where this method can be applied is described at the end of the article. Copyright © 2001 John Wiley & Sons, Ltd.
A modal pushover analysis procedure for estimating seismic demands for buildings
Authors: Chopra Anil K. , Goel Rakesh K. 
Published: August 2002

AbstractDeveloped herein is an improved pushover analysis procedure based on structural dynamics theory, which retains the conceptual simplicity and computational attractiveness of current procedures with invariant force distribution. In this modal pushover analysis (MPA), the seismic demand due to individual terms in the modal expansion of the effective earthquake forces is determined by a pushover analysis using the inertia force distribution for each mode. Combining these ‘modal’ demands due to the first two or three terms of the expansion provides an estimate of the total seismic demand on inelastic systems. When applied to elastic systems, the MPA procedure is shown to be equivalent to standard response spectrum analysis (RSA). When the peak inelastic response of a 9‐storey steel building determined by the approximate MPA procedure is compared with rigorous non‐linear response history analysis, it is demonstrated that MPA estimates the response of buildings responding well into the inelastic range to a similar degree of accuracy as RSA in estimating peak response of elastic systems. Thus, the MPA procedure is accurate enough for practical application in building evaluation and design. Copyright © 2001 John Wiley & Sons, Ltd.
An estimation of displacement limits for ductile systems
Authors: Paulay Tom 
Published: August 2002

AbstractTo enable acceptable seismic displacement demands to be specified, the displacement capacity of a structural system needs to be known. This is controlled by selected performance criteria. It is postulated that the assignment of fractions of the required strength of the system to its components may be arbitrary. This then enables the displacement capacity of buildings to be evaluated without the knowledge of its seismic strength. A redefinition of some traditionally used structural properties is a prerequisite to applications. The study of a reinforced concrete wall–frame dual system illustrates rationale and extreme simplicity of application. Copyright © 2001 John Wiley & Sons, Ltd.
Systematic assessment of irregular building–soil interaction using efficient modal analysis
Authors: Wu Wen‐Hwa , Wang Jer‐Fu , Lin Chi‐Chang 
Published: August 2002

AbstractIn this paper an efficient methodology applying modal analysis is developed to assess systematically the combined soil–structure interaction and torsional coupling effects on asymmetric buildings. This method is implemented in the frequency domain to accurately incorporate the frequency‐dependent foundation impedance functions. For extensively extracting the soil–structure interaction effects, a diagonal transfer matrix in the modal space is derived. A comprehensive investigation of asymmetric building–soil interaction can then be conveniently conducted by examining various types of response quantities. Results of parametric study show that the increasing height‐to‐base ratio of a structure generally amplifies its translational and torsional responses. Moreover, both the translational and torsional responses are reduced for the case where the two resonant frequencies are well separated and this reduction is enhanced with the decreasing values of the relative soil stiffness and the height‐to‐base ratio. The most noteworthy phenomenon may be the fact that the SSI effects can enlarge the translational response if the structure is slender and the two resonant frequencies are very close. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of response and energy in actively controlled structures
Authors: Wong Kevin K. F. , Yang Rong 
Published: August 2002

AbstractA computational method of energy evaluation is derived to study the elastic responses and energy distribution of actively controlled single‐degree‐of‐freedom (SDOF) structures during earthquakes. Contrary to the common perception that applying active control force pumps energy into the structure, the applied control force can actually reduce the energy in the structure by reducing the input energy from earthquakes to the structure. In addition, applying control force can dissipate a large amount of energy in the structure when this control force is applied in the direction opposite to the displacement and velocity responses. To demonstrate this energy mechanism in active controlled structures, the two most popular control algorithms, optimal linear control (OLC) and instantaneous optimal control (IOC) algorithms, are used to calculate the control response and energy spectra. One‐step time delay is incorporated into the algorithms to take into consideration the practical aspect of active control. The effects of different earthquakes and damping ratios on control energy and response spectra are studied. These studies show that both OLC and IOC are very effective in reducing the structural displacement and velocity responses by reducing the input earthquake energy as well as dissipating a large amount of energy in the structure. Copyright © 2001 John Wiley & Sons, Ltd.
Bomb‐fallout 137Cs as a marker of geomorphic stability in dune sands and soils, Pinery Provincial Park, Ontario, Canada
Authors: Vanden Bygaart A. J. , Protz R. 
Published: August 2002

AbstractThe anthropogenic radionuclide 137Cs has been extensively utilized as a tracer of geomorphic processes in the northern hemisphere since its deposition during atmospheric testing of nuclear devices in the 1950s and 1960s. The distribution of bomb‐fallout 137Cs was measured on a sequence of coastal dune sands and soils at Pinery Provincial Park, on the coast of Lake Huron in southern Ontario, Canada. The depth distribution within the stabilized, developed soils inland reflected the relationship between clay content and the adsorption and immobilization of the radionuclide. However, the influence of soil organic matter, silt‐sized particles and vegetation cycling on the profile distribution could not be discounted. Within the geomorphically dynamic dune sands near the coast, there was a significant activity of 137Cs even though the sands were lacking in clay‐sized particles. Within a buried soil on the inland side of a large active dune blowout, the distribution of 137Cs with depth was useful as a stratigraphic marker of the rates of accumulation of sands at that position. Therefore 137Cs may be a useful alternative to erosion pins, sequential air photos and sediment traps in the monitoring of dune destabilization in coastal environments. Copyright © 2001 John Wiley & Sons, Ltd.
A simple model for the formation of vegetated dunes
Authors: Nishimori Hiraku , Tanaka Hirohisa 
Published: August 2002

AbstractA simple model for the dynamics of dunes associated with vegetation is proposed. Using the model, the formation processes of transverse dunes, parabolic dunes and elongated parabolic dunes are simulated according to two environmental factors: (i) the amount of sand at the source; (ii) the wind force. The results have qualitative correspondence to the real counterpart, and the simplicity of the algorithm and the consequent ease of handling this model provide us with wide applicability for the investigation of the complex interplay between vegetation and dunes. Copyright © 2001 John Wiley & Sons, Ltd.
Characteristics of an isomenthone‐rich somaclonal mutant isolated in a geraniol‐rich rose‐scented geranium accession of Pelargonium graveolens
Authors: Gupta Ritika , Mallavarapu G. R. , Banerjee S. , Kumar Sushil 
Published: August 2002

AbstractA somaclonal essential oil mutant (IRPG) was identified among the regenerants induced in callus cultures initiated with the leaf explants of geranium Pelargonium graveolens cv. Kunti. While the shoot essential oil of the wild‐type parent was rich in geraniol, the oil of the IRPG had isomenthone as the major monoterpenoid component. The IRPG oil had about 71% isomenthone, 6% citronellol and 3% geraniol, as compared to the parental variety oil, in which isomenthone, citronellol and geraniol contents were about 8%, 13% and 40%, respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Chemical composition of the essential oils of Cinnamomum cordatum Kosterm
Authors: Jantan Ibrahim bin , Ayop Norsiha , Hiong Au Bee , Ahmad Abu Said 
Published: August 2002

AbstractThe essential oils of Cinnamomum cordatum Kosterm. were analysed by gas chromatography, by retention indices and GC–MS. Forty‐three compounds were identified in the leaf oil and the major constituents were linalool (17.3%), (E)‐methyl cinnamate (17.1%), β‐phellandrene (9.0%), benzyl benzoate (7.6%), terpinen‐4‐ol (7.0%), benzyl salicylate (4.7%) and methyl eugenol (4.4%). The bark oil was made up almost entirely of methyl eugenol (92.1%). Copyright © 2002 John Wiley & Sons, Ltd.
Numerical simulation of tidal bore in Hangzhou Gulf and Qiantangjiang
Authors: Su M. D. , Xu X. , Zhu J. L. , Hon Y. C. 
Published: August 2002

AbstractIn this paper, a new numerical model, based on a set of non‐linear shallow water equations is developed for the simulation of the formation and evolution of tidal bore in the Hangzhou Gulf and Qiantangjiang river of China. The numerical method and boundary conditions are described in detail. The method is validated against analytical solutions and experimental data. Simulation of the actual tidal bore in Hangzhou Gulf and its propagation in the Qiantangjiang river are performed. Numerical results show that this proposed method is effective for the prediction of tidal bore and current flow at the entrance of Qiantangjiang river. Copyright © 2001 John Wiley & Sons, Ltd.
A comparison of boundary element and finite element methods for modeling axisymmetric polymeric drop deformation
Authors: Hooper Russell , Toose Matthijs , Macosko Christopher W. , Derby Jeffrey J. 
Published: August 2002

AbstractA modified boundary element method (BEM) and the DEVSS‐G finite element method (FEM) are applied to model the deformation of a polymeric drop suspended in another fluid subjected to start‐up uniaxial extensional flow. The effects of viscoelasticity, via the Oldroyd‐B differential model, are considered for the drop phase using both FEM and BEM and for both the drop and matrix phases using FEM. Where possible, results are compared with the linear deformation theory. Consistent predictions are obtained among the BEM, FEM, and linear theory for purely Newtonian systems and between FEM and linear theory for fully viscoelastic systems. FEM and BEM predictions for viscoelastic drops in a Newtonian matrix agree very well at short times but differ at longer times, with worst agreement occurring as critical flow strength is approached. This suggests that the dominant computational advantages held by the BEM over the FEM for this and similar problems may diminish or even disappear when the issue of accuracy is appropriately considered. Fully viscoelastic problems, which are only feasible using the FEM formulation, shed new insight on the role of viscoelasticity of the matrix fluid in drop deformation. Copyright © 2001 John Wiley & Sons, Ltd.
An unconditionally stable, explicit Godunov scheme for systems of conservation laws
Authors: Guinot Vincent 
Published: August 2002

AbstractCommon explicit, Godunov‐type schemes are subject to a stability constraint. The time‐line interpolation technique allows this constraint to be eliminated without having to make the scheme implicit or to linearize the equations. For 2×2 systems of conservation laws, a system of non‐linear equations has to be solved in the general case to determine the left and right states of the Riemann problems at the cell interfaces. However, if one cell in the domain is wide enough for the Courant number to be locally lower than unity, it is not necessary to solve a system anymore and the values at the next time step can be computed directly. The method is detailed for linear and non‐linear scalar advection, as well as for 2×2 systems of hyperbolic conservation laws. It is illustrated by an application to a simplified model for two‐phase flow in pipes, which is described using a 2×2 system of non‐linear hyperbolic equations. Copyright © 2002 John Wiley & Sons, Ltd.
A domain decomposition method for modelling Stokes flow in porous materials
Authors: Liu Guangli , Thompson Karsten E. 
Published: August 2002

AbstractAn algorithm is presented for solving the Stokes equation in large disordered two‐dimensional porous domains. In this work, it is applied to random packings of discs, but the geometry can be essentially arbitrary. The approach includes the subdivision of the domain and a subsequent application of boundary integral equations to the subdomains. This gives a block diagonal matrix with sparse off‐block components that arise from shared variables on internal subdomain boundaries. The global problem is solved using a biconjugate gradient routine with preconditioning. Results show that the effectiveness of the preconditioner is strongly affected by the subdomain structure, from which a methodology is proposed for the domain decomposition step. A minimum is observed in the solution time versus subdomain size, which is governed by the time required for preconditioning, the time for vector multiplications in the biconjugate gradient routine, the iterative convergence rate and issues related to memory allocation. The method is demonstrated on various domains including a random 1000‐particle domain. The solution can be used for efficient recovery of point velocities, which is discussed in the context of stochastic modelling of solute transport. Copyright © 2002 John Wiley & Sons, Ltd.
The pricing of stock index futures spreads at contract expiration
Authors: Frino Alex , McKenzie Michael D. 
Published: August 2002

AbstractThis paper conducts an empirical analysis of the mispricing of calendar spreads for stock index futures.
Using recent data drawn from the Sydney Futures Exchange, a sharp increase in the magnitude of spread mispricing
immediately prior to maturity of the near contract is documented. This pattern in mispricing is related to a
sharp decline in open interest in the near contract and an increase in open interest in the deferred contract.
Further, the direction of mispricing of the near and deferred contracts are more likely to move in opposite
directions as the near contract approaches maturity. These findings are consistent with the hypothesis that
traders seeking to roll‐over their positions from near to deferred futures contracts close to maturity
increase the magnitude of spread mispricing. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:451–469,
2002
The effect of net positions by type of trader on volatility in foreign currency futures markets
Authors: Wang Changyun 
Published: August 2002

AbstractWe investigate the effect of net positions by type of trader on return volatility in six foreign currency
futures markets using the weekly Commitments of Traders (COT) data. When net positions are decomposed
into expected and unexpected components, we find that expected net positions by type of trader generally do not
co‐vary with volatility. However, volatility is positively associated with shocks (in either
direction) in net positions of speculators and small traders, and negatively related to shocks (in
either direction) in net positions of hedgers. This evidence suggests that changes in speculative positions
destabilize the market. Consistent with dispersion of beliefs models and noise trading theories, hedgers appear to
possess private information, whereas speculators and small traders are less informed in these markets. © 2002
Wiley Periodicals, Inc. Jrl Fut Mark 22:427–450, 2002
A Study of Arbitrage Efficiency Between the FTSE‐100 Index Futures and Options Contracts
Authors: Draper Paul , Fung Joseph K. W. 
Published: August 2002

AbstractDespite the importance of the London markets and the significance of the relationship for market makers,
little published research is available on arbitrage between the FTSE‐100 Index futures and the
FTSE‐100 European index options contracts. This study uses the put–call–futures parity
condition to throw light on the relationship between options and futures written against the FTSE Index. The
arbitrage methodology adopted in this study avoids many of the problems that have affected prior research on the
relationship between options or futures prices and the underlying index. The problems that arise from
nonsynchroneity between options and futures prices are reduced by the matching of options and futures prices
within narrow time intervals with time‐stamped transaction data. This study allows for realistic trading
and market‐impact costs. The feasibility of strategies such as execute‐and‐hold and early
unwinding is examined with both ex‐post and ex‐ante simulation tests that take into consideration
possible execution time lags for the arbitrage trade. This study reveals that the occurrence of matched
put–call–futures trios exhibits a U‐shaped intraday pattern with a concentration at both open
and close, although the magnitude of observed mispricings has no discernible intraday pattern. Ex‐post
arbitrage profits for traders facing transaction costs are concentrated in at‐the‐money options.
As in other major markets, despite important microstructure differences, opportunities are generally rapidly
extinguished in less than 3 min. The results suggest that arbitrage opportunities for traders facing transaction
costs are small in number and confirm the efficiency of trading on the London International Financial Futures
and Options Exchange. © 2002 John Wiley & Sons, Inc. Jrl Fut Mark 22:31–58, 2002
Sequencing of intron 3 of HMGA2 uncovers the existence of a novel exon
Authors: Hauke Sven , Flohr Aljoscha M. , Rogalla Piere , Bullerdiek Jörn 
Published: August 2002

AbstractAberrations affecting the gene encoding the high mobility group protein HMGA2 (formerly HMGIC) have been found in a variety of human tumors, e.g., uterine leiomyomas, lipomas, and pulmonary chondroid hamartomas. These aberrations lead to fusion genes, transcriptional up‐regulation, or aberrant transcripts of HMGA2. In the latter case, truncated transcripts consisting of exons 1 to 3 of HMGA2, encoding the three DNA‐binding domains, and ectopic sequences derived from chromosome 12 are frequent. There are several lines of evidence indicating that the biological and tumorigenic features of truncated HMGA2 derivatives, i.e., those composed of the DNA‐binding domains and a shortened acidic tail, clearly differ from those of the normal protein consisting of three DNA‐binding domains and one large acidic tail. By sequencing the complete 112 kb third intron of HMGA2, we were able to detect several of the ectopic sequences, known as fused to HMGA2. Expression studies revealed co‐expression of one of these transcripts with the normal transcript in tumors with 12q14‐15 aberrations as well as in other tumors, and in normal tissues. Thus, this transcript (HMGA2b) is flanked by an alternative terminal exon of HMGA2. Due to the loss of the part encoding the acidic tail, the expression of the latter transcript may have more striking effects than the “wild type” HMGA2 (HMGA2a) in terms of tumorigenesis. This finding clearly indicates that functional studies also should address the role of the HMGA2b transcript. © 2002 Wiley‐Liss, Inc.
Mutations of the AML1 gene in acute myeloid leukemia of FAB types M0 and M7
Authors: Langabeer Stephen E. , Gale Rosemary E. , Rollinson Sara J. , Morgan Gareth J. , Linch David C. 
Published: August 2002

AbstractThe AML1 gene encodes a transcription factor that, together with its heterodimeric partner CBFB, regulates a number of target genes that are essential for normal hemopoiesis. In acute myeloid leukemia (AML), AML1 is disrupted not only by chromosomal translocations but also by mutations in the runt domain, which binds both DNA and CBFB. Acquired mutations have been described predominantly in the AML FAB type M0. To date, most patients appear to have biallelic disease, suggesting a complete lack of normal AML1 function. Inherited loss of function mutations thought to lead to haploinsufficiency also have been described in patients who have a familial disorder with predisposition to AML (FPD/AML), indicating the role of AML1 in megakaryopoiesis. Using single‐strand conformation polymorphism analysis, we studied the AML1 runt domain in 41 patients with M0 AML and identified potentially pathologic mutations in five (12%). Biallelic disease could be confirmed in only one patient, using loss of heterozygosity studies. At least three of the mutations would lead to truncated proteins similar to those reported in FPD/AML, suggesting that haploinsufficiency plays a role in the pathogenesis of this minimally differentiated type of leukemia. The incidence of acquired mutations in AML patients with acute megakaryoblastic leukemia (FAB type M7) was the same as that reported in other non‐M0 patients, with only one mutation detected in 20 (5%) patients studied. © 2002 Wiley‐Liss, Inc.