bluuebunny/crossref_metadata_2025_split huggingface dataset:
Etoposide and merbarone are clastogenic and aneugenic in the mouse bone marrow micronucleus test complemented by fluorescence in situ hybridization with the mouse minor satellite DNA probe
Authors: Attia S.M. , Kliesch U. , Schriever‐Schwemmer G. , Badary O.A. , Hamada F.M. , Adler I.‐D. 
Published: March 2003

AbstractThe topoisomerase II (topo II) inhibitors etoposide (VP‐16) and merbarone (MER) were investigated with the in vivo micronucleus test (MN test) combined with fluorescence in situ hybridization (FISH) using the mouse minor satellite DNA probe to discriminate MN of clastogenic and aneugenic origin. All experiments were performed with male (102/ElxC3H/El) F1 mice bred in the mouse colony of the GSF Research Center. The sample size per experimental group was five animals and 2,000 polychromatic erythrocytes (PCE) were scored per animal from coded slides in the conventional MN test. A separate set of coded slides was used for the FISH analysis. All treatments consisted of single intraperitoneal injections. Colchicine (COL, 3 mg/kg) and mitomycin (MMC, 1 mg/kg) were used as a positive control aneugen and clastogen, respectively, and these compounds produced the expected responses. A dose of 1 mg/kg VP‐16 induced 3.44% MNPCE (compared to the concurrent solvent control of 0.37%, P < 0.001) and of these 39.9% (1.4% MNPCE) showed one or more fluorescent signals. MER (7.5–60 mg/kg) increased the MNPCE frequencies in a dose‐dependent manner, with 15 mg/kg being the lowest positive dose. At the highest dose of 60 mg/kg of MER, a total of 4.26% MNPCE were found (compared to 0.31% in the concurrent solvent control, P < 0.001) and of these 46.2% (2.0% MNPCE) contained one or more fluorescent signals. The data demonstrate that VP‐16 and MER induced both clastogenic and aneugenic events despite their different modes of topo II inhibition. Environ. Mol. Mutagen. 41:99–103, 2003. © 2003 Wiley‐Liss, Inc.
Photomutagenicity of thiabendazole, a postharvest fungicide, in bacterial assays
Authors: Watanabe‐Akanuma Mie , Ohta Toshihiro , Yamagata Hideo 
Published: March 2003

AbstractWe investigated the photomutagenicity of thiabendazole (TBZ), a postharvest fungicide commonly used on imported citrus fruits. Using UVA light (320–400 nm), we irradiated bacterial cultures with or without TBZ in a 24‐well multiplate. UVA‐irradiation without TBZ was not mutagenic to the tester strains, nor was unirradiated TBZ. TBZ was strongly photomutagenic in Escherichia coli WP2uvrA and WP2uvrA/pKM101 strains, weakly photomutagenic in Salmonella typhimurium TA100 and TA98, and not photomutagenic in S. typhimurium TA1535 and TA1538. The photomutagenicity of TBZ was more evident in WP2uvrA/pKM101, which carries the trpE65 ochre mutation (TAA), than in TA100, which carries the hisG46 missense mutation (CCC). In E. coli WP3101–WP3106 and the corresponding pKM101‐containing strains, photoactivated TBZ induced predominantly G:C→A:T transitions and A:T→T:A transversions. In the plasmid‐containing strains only, TBZ induced a moderate number of A:T→G:C transitions and a few A:T→C:G and G:C→T:A transversions. The observation that UVA‐irradiated TBZ mutated both G:C and A:T basepairs may explain why WP2uvrA/pKM101 was more sensitive to its mutagenicity than TA100. TBZ that was irradiated before it was added to the WP2uvrA/pKM101 cells was not photomutagenic, which suggests that the photomutagenic products of TBZ were unstable or rapidly reacted with other molecules before being incorporated into cells. Environ. Mol. Mutagen. 41:92–98, 2003. © 2003 Wiley‐Liss, Inc.
Mouse bone marrow micronucleus test results do not predict the germ cell mutagenicity of N‐hydroxymethylacrylamide in the mouse dominant lethal assay
Authors: Witt Kristine L. , Hughes Lori A. , Burka Leo T. , McFee Alfred F. , Mathews James M. , Black Sherry L. , Bishop Jack B. 
Published: March 2003

AbstractN‐Hydroxymethylacrylamide (NHMA), a mouse carcinogen inactive in the Salmonella assay and mouse micronucleus (MN) assay, was tested for reproductive effects in a mouse continuous breeding study. In that study, increased embryonic deaths were observed after 13 weeks exposure of parental animals to NHMA via drinking water (highest dose, 360 ppm); the results indicated the possible induction of chromosome damage in germ cells of treated males. An additional mouse MN test was conducted using a 31‐day treatment period to better match the dosing regimen used in the breeding study; the results were negative. Additional studies were conducted to explore the germ cell activity of NHMA. A male mouse dominant lethal study was conducted using a single intraperitoneal injection of 150 mg/kg NHMA; the results were negative. A follow‐up study was conducted using fractionated dosing, 50 mg/kg/day for 5 days; again, no increase in dominant lethal mutations was observed. NHMA (180–720 ppm) was then administered to male mice in drinking water for 13 weeks, during which three sets of matings occurred. Two weeks after mating, females were killed and the uterine contents were analyzed. Large, dose‐related increases in dominant lethal mutations were observed with increasing length of exposure. The magnitude of the increases stabilized after 8 weeks of treatment. However, the frequency of micronucleated peripheral blood erythrocytes was not elevated in mice treated for 13 weeks with NHMA in drinking water. Thus, NHMA appears to be unique in inducing genetic damage in germ cells but not somatic cells of male mice. Environ. Mol. Mutagen. 41:111–120, 2003. Published 2003 Wiley‐Liss, Inc.
Biomonitoring with the comet assay of Greek greenhouse workers exposed to pesticides
Authors: Piperakis S.M. , Petrakou E. , Tsilimigaki S. , Sagnou M. , Monogiudis E. , Haniotakis G. , Karkaseli H. , Sarikaki E. 
Published: March 2003

AbstractThe pesticides in use in Greek greenhouses include a number of agents known to be mutagens and carcinogens. In the present study, we evaluated whether occupational exposure of agricultural workers to a complex mixture of pesticides resulted in a significant increase in DNA damage in human peripheral blood lymphocytes (PBLs). A total of 116 healthy individuals were divided into groups based on exposure to pesticides, smoking status, and gender. Alkaline comet assays performed on PBLs from these individuals indicated no statistically significant differences in basal DNA damage between the study groups. In addition, exposure of PBLs to a dose of hydrogen peroxide led to a similar degree of DNA damage and subsequent repair for all the study populations. The results of the study indicate that the agricultural workers who participated in this study had no detectable increase in DNA damage or alteration in the cellular response to DNA damage. Environ. Mol. Mutagen. Environ. Mol. Mutagen. 41:104–110, 2003. © 2003 Wiley‐Liss, Inc.
Experimental and theoretical simulations of seismic poundings between two adjacent structures
Authors: Chau K. T. , Wei X. X. , Guo X. , Shen C. Y. 
Published: March 2003

AbstractShaking table tests have been carried out to investigate the pounding phenomenon between two steel towers of different natural frequencies and damping ratios, subject to different combinations of stand‐off distance and seismic excitations. Both harmonic waves and ground motions of the 1940 El Centro earthquake are used as input. Subjected to sinusoidal excitations, poundings between the two towers could appear as either periodic or chaotic. For periodic poundings, impact normally occurs once within each excitation cycle or within every other excitation cycle. A type of periodic group poundings was also observed for the first time (i.e. a group of non‐periodic poundings repeating themselves periodically). Chaotic motions develop when the difference of the natural frequency of the two towers become larger. Under sinusoidal excitations, the maximum relative impact velocity always develops at an excitation frequency between the natural frequencies of the two towers. Both analytical and numerical predictions of the relative impact velocity, the maximum stand‐off distance, and the excitation frequency range for pounding occurrences were made and found to be comparable with the experimental observations in most of the cases. The stand‐off distance attains a maximum when the excitation frequency is close to that of the more flexible tower. Pounding appears to amplify the response of the stiffer structure but suppress that of the more flexible structure; and this agrees qualitatively with previous shaking table tests and theoretical studies. Copyright © 2003 John Wiley & Sons, Ltd.
Scattering of elastic waves by a general anisotropic basin. Part 2: a 3D model
Authors: Dravinski Marijan 
Published: March 2003

AbstractScattering of plane harmonic waves by a three‐dimensional basin of arbitrary shape embedded within elastic half‐space is investigated by using an indirect boundary integral equation approach. The materials of the basin and the half‐space are assumed to be the most general anisotropic, homogeneous, linearly elastic solids without any material symmetry (i.e. triclinic).The unknown scattered waves are expressed in terms of three‐dimensional triclinic time harmonic full‐space Green's functions. The results have been tested by comparing the surface response of semi spherical isotropic and transversely isotropic basins for which the numerical solutions are available.Surface displacements are presented for a semicircular basin subjected to a vertical incident plane harmonic pseudo‐P‐, SV‐, or SH‐wave. These results are compared with the motion obtained for the corresponding equivalent isotropic models. The results show that presence of the basin may cause significant amplification of ground motion when compared to the free‐field displacements. The peak amplitude of the predominant component of surface motion is smaller for the anisotropic basin than for the corresponding isotropic one. Anisotropic response may be asymmetric even for symmetric geometry and incidence. Anisotropic surface displacement generally includes all three components of motion which may not be the case for the isotropic results. Furthermore, anisotropic response strongly depends upon the nature of the incident wave, degree of material anisotropy and the azimuthal orientation of the observation station.These results clearly demonstrate the importance of anisotropy in amplification of surface ground motion. Copyright © 2003 John Wiley & Sons, Ltd.
The effects of torsion and motion coupling in site response estimation
Authors: Ghayamghamian Mohammad R. , Motosaka Masato 
Published: March 2003

AbstractSoil amplification characteristics are investigated using data from the Chibaken‐Toho‐Oki earthquake and its aftershocks recorded at Chiba dense array in Japan. The frequency‐dependent amplification function of soil is calculated using uphole‐to‐downhole spectral ratio analysis, considering the horizontal components of shear wave. The identified spectral ratios consistently demonstrate the splitting of peaks in their resonance frequencies and low amplification values in comparison with a 1D model. The torsional behaviour and horizontal ground motion coupling are clarified as the reasons for these phenomena at the site. To prove the hypothesis, the torsional motion is directly evaluated using the data of the horizontal dense array in different depths at the site. The comparison between Fourier spectra of torsional motion and identified transfer functions reveals the peaks at the same frequencies. The wave equation including torsion and horizontal motion coupling is introduced and solved for the layered media by applying wave propagation theory. Using the developed model, the effects of torsional motion with horizontal motion coupling on soil transfer function are numerically examined. Splitting and low amplification at resonance frequencies are confirmed by the results of numerical analysis. Furthermore, the ground motion in two horizontal directions at the site is simulated using site geotechnical specification and optimizing the model parameters. The simulated and recorded motions demonstrate good agreement that is used to validate the hypothesis. In addition, the spectral density of torsional ground motions are compared with the calculated one and found to be well predicted by the model. Finally, the results are used to explain the overestimation of damping in back‐calculation of dynamic soil properties using vertical array data in small strain level. Copyright © 2003 John Wiley & Sons, Ltd.
Optimum seismic zoning for multiple types of structures
Authors: García‐Pérez Jaime , Castellanos Francisco , Díaz Orlando 
Published: March 2003

AbstractWe consider zoning for the design criterion that minimizes the expected present value of the total cost, including the initial cost as well as losses due to damage and failure. The problem consists of the following: given the number of zones, their boundaries and design coefficients must be such that they minimize the expected present value of all structures built in the region. We will refer to solutions in one or more dimensions, depending on the number of the types of structures built in the region to be zoned. Two methods are proposed to solve the problems. The first method is based on the different combinations performed in order to attain optimum zoning. The second method uses an analogy to the evolution of biological systems. The work ends by applying the methods developed to a region of known seismicity. Copyright © 2003 John Wiley & Sons, Ltd.
Reliability‐based robust control for uncertain dynamical systems using feedback of incomplete noisy response measurements
Authors: Yuen Ka‐Veng , Beck James L. 
Published: March 2003

AbstractA reliability‐based output feedback control methodology is presented for controlling the dynamic response of systems that are represented by linear state‐space models. The design criterion is based on a robust failure probability for the system. This criterion provides robustness for the controlled system by considering a probability distribution over a set of possible system models with a stochastic model of the excitation so that robust performance is expected. The control command signal can be calculated using incomplete response measurements at previous time steps without requiring state estimation. Examples of robust structural control using an active mass driver on a shear building model and on a benchmark structure are presented to illustrate the proposed method. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of parametric ground motion random fields from spatially recorded seismic data
Authors: Zerva A. , Beck J. L. 
Published: March 2003

AbstractA methodology for the identification of random field models for the description of seismic ground motions recorded over extended areas is presented. The approach (i) embeds seismic ground motion parameter estimation in a probabilistic framework, and (ii) identifies simultaneously point and spatial models for the seismic ground motion random field from either smoothed or unsmoothed non‐parametric spectral estimates. It is shown that parametric coherency estimates identified by means of this approach are stable and insensitive to the amount of smoothing performed on the empirical data. The approach and its findings have a significant impact on the evaluation of parametric ground motion models for the seismic response evaluation of lifelines. Copyright © 2003 John Wiley & Sons, Ltd.
Experimental study on multiple tuned mass dampers to reduce seismic responses of a three‐storey building structure
Authors: Chen Genda , Wu Jingning 
Published: March 2003

AbstractIn this study, several mass dampers were designed and fabricated to suppress the seismic responses of a ¼‐scale three‐storey building structure. The dynamic properties of the dampers and structure were identified from free and forced vibration tests. The building structure with or without the dampers was, respectively, tested on a shake table under the white noise excitation, the scaled 1940 El Centro earthquake and the scaled 1952 Taft earthquake. The dampers were placed on the building floors using the sequential procedure developed by the authors in previous studies. Experimental results indicated that the multiple damper system is substantially superior to a single tuned mass damper in mitigating the floor accelerations even though the multiple dampers are sub‐optimal in terms of tuning frequency, damping and placement. These results validated the sequential procedure for placement of the multiple dampers. The structure was also analysed numerically based on the shake table excitation and the identified structure and damper parameters for all test cases. Numerical and experimental results are in good agreement, validating the dynamic properties identified. Copyright © 2003 John Wiley & Sons, Ltd.
Steel frames with bracing mechanism and hysteretic dampers
Authors: Phocas M. C. , Pocanschi A. 
Published: March 2003

AbstractA new earthquake resistant structural system for multi‐storey frame structures, based on a dual function of its bracing components, is developed. This consists of a hysteretic damper device and a cross‐bracing mechanism with a kinetic closed circuit, working only in tension, so that cable members can be used for this purpose. Solutions are presented regarding the connections' design of three types of structural frame system, that are concerned throughout the study: braced moment free frame, braced moment resisting frame with moment free supports, and with moment resisting supports. The dynamic behaviour of the system is investigated on the basis of an SDOF model, and based on the response spectra method an approximate design approach of the controlled structures is shown. From the time history analysis of the structural systems for the El Centro earthquake the areas of appropriate stiffness relations of the frames to the hysteretic dampers and the cable braces are deduced, so that the energy dissipation of the system may be controlled by the damper‐cable bracing mechanism. Based on the results of these studies, a predesign approach is developed for the implementation of the control system in frame structures. Copyright © 2003 John Wiley & Sons, Ltd.
Changes in geometry and subglacial drainage of Midre Lovénbreen, Svalbard, determined from digital elevation models
Authors: Rippin David , Willis Ian , Arnold Neil , Hodson Andrew , Moore John , Kohler Jack , BjöRnsson Helgi 
Published: March 2003

AbstractDigital elevation models (DEMs) of the bed and surface of the polythermal Midre Lovénbreen, Svalbard, are used to identify changes in glacier geometry between 1977 and 1995. The calculated mean annual mass balance (−0·61 m water equivalent (w.e.) a−1) is more negative than that derived from field measurements (−0·35 m w.e. a−1), although the error associated with this value (±0·7 m a−1) suggests that the difference may be accounted for by errors. However, similar discrepancies between DEM‐based and field‐based measurements of mass balance have been reported elsewhere in Svalbard. Although errors may be responsible, patterns of surface elevation change may also be explained in terms of patterns of ablation, accumulation, and dynamics. The theoretical structure of the subglacial drainage system is modelled using different assumptions about subglacial water pressure, in 1977 and 1995. These reconstructions are compared with the observed positions of proglacial outlet streams. Decreasing subglacial water pressure results in a decrease in the influence of surface morphology and an increase in the role of the bed topography on drainage routing, which generally leads to more dispersed drainage. Long‐term changes in the position of proglacial outlet streams occur as a result of changes in glacier geometry, but short‐term changes may also occur in response to early season water pressures, controlled by meteorological and hydrological conditions. Copyright © 2003 John Wiley & Sons, Ltd.
From forecasting to foresight processes—new participative foresight activities in Germany
Authors: Cuhls Kerstin 
Published: March 2003

AbstractThe definitions of forecasting vary to a certain extent, but they all have the view into the future in common. The future is unknown, but the broad, general directions can be guessed at and reasonably dealt with. Foresight goes further than forecasting, including aspects of networking and the preparation of decisions concerning the future. This is one reason why, in the 1990s, when foresight focused attention on a national scale in many countries, the wording also changed from forecasting to foresight. Foresight not only looks into the future by using all instruments of futures research, but includes utilizing implementations for the present. What does a result of a futures study mean for the present? Foresight is not planning, but foresight results provide ‘information’ about the future and are therefore one step in the planning and preparation of decisions. In this paper, some of the differences are described in a straightforward manner and demonstrated in the light of the German foresight process ‘Futur’. Copyright © 2003 John Wiley & Sons, Ltd.
Developing futures for agriculture in the Netherlands: a systematic exploration of the strategic value of foresight
Authors: van der Meulen Barend , de Wilt Jan , Rutten Hans 
Published: March 2003

AbstractScience and Technology Foresight (STF) is an interactive and systematic exploration of future dynamics of science, technology, the economy and society with the aim of identifying and supporting viable strategies and actions for stakeholders. In comparison to futures studies and forecasting, the literature on foresight has paid little attention to its actual strategic value. In this paper we review the 1995–1999 foresight programme of the Dutch National Council for Agricultural Research, and evaluate some key dimensions of the foresight process, including the selection and range of participants, the immediate impact of interactive tools such as workshops and the ultimate effect on the strategic thinking in the agricultural sector. The evaluation indicates that strategic thinking in the Dutch agricultural sector has improved. The paper concludes with suggestions for monitoring and evaluation of foresight that may increase the understanding of foresight's strategic value. Copyright © 2003 John Wiley & Sons, Ltd.
Foresight in a research institution: a critical review of two exercises
Authors: de Lattre‐Gasquet Marie , Petithuguenin Philippe , Sainte‐Beuve Jérôme 
Published: March 2003

AbstractForesight is a powerful tool for imagining possible futures, for raising public awareness, for helping decision‐making and addressing questions related to the relationship between science and society. In this article we make a critical analysis of two foresight exercises organized by a research institution. A precise description of the exercises conducted on the futures of the cocoa commodity chain and theheveacommodity chain helps to understand the possible processes of a foresight exercise, what foresight can achieve and what kinds of difficulties can occur. From these experiences, proposals are made to facilitate the development of strategic intelligence in a research institution and improve the linkages between foresight, evaluation and programme formulation. The role of foresight in transforming knowledge and in pushing a closed system into a political arena is also shown. Copyright © 2003 John Wiley & Sons, Ltd.