bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnitude assessment of northwestern european earthquakes
Authors: Ambraseys N. N.
Published: March 2007

A homogeneous and internally consistent body of regional magnitudes is needed not only for the statistical study of seismicity but also for the modelling of seismic sources and for the hazard assessment of engineering sites. Also the assessment of the design ground motions for engineering projects requires homogeneous magnitude estimates. The nature of the available data for U.K. and Northwestern European earthquakes, and of the events themselves, is such that we are concerned with the assessment of magnitudes at the lower end of the scale, and thus great importance focuses on the uniform calculation of magnitudes within a relatively narrow range of M values. The purpose of this study is to present the uniform re‐assessment of magnitudes for British and Northwestern European earthquakes for the period 1900 to 1984. It is shown that, for the larger events, surface‐wave magnitudes can be estimated uniformly and that neither a period constraint at 20 seconds nor distance effects for the regional conditions considered appear to play an important role. For smaller events, crustal phases at short distances have been used to derive calibration curves for a magnitude which, at larger distances and longer periods would fit the magnitude scale of surface waves.
Dynamic response of bilinear asymmetric structures
Authors: Syamal Pradip K. , Pekau O. A.
Published: March 2007

The inelastic behaviour of eccentric single‐storey building structures subjected to sinusoidal ground excitation is examined. The Kryloff‐Bogoliuboff method is employed to provide approximate solutions in the amplitude‐frequency domain. Structural resisting elements are assumed to exhibit bilinear hysteretic behaviour and coupled response is investigated in terms of both system response as well as individual element ductility requirements. In addition to demonstrating the well‐known softening property inherent in yielding systems, the importance of the principal parameters governing coupled response is evaluated in a consistent parametric fashion. Within the context of earthquake resistant building design, the results indicate the absence of amplified response when torsional and translational frequencies are close, in contrast to the much emphasized observation of internal resonance for linear elastic structures. Equally important, structural elements located on the stiff edge of eccentric buildings are found to be only marginally affected by the magnitude of the eccentricity, thus indicating that seismic building codes which reduce design requirements for these elements underestimate actual behaviour substantially.
Intensity‐attenuation and magnitude‐intensity relationships for northwest european earthquakes
Authors: Ambraseys N.
Published: March 2007

This study shows that, for Northwest Europe, an intraplate region of subdued seismicity, a comparatively simple attenuation model is adequate to predict quite accurately the fall‐off of intensity with distance. The analysis shows that focal depths determined from macroseismic data are confined in the upper 25 km, and that shallow shocks attenuate far more rapidly than deeper events. There is no evidence for a regional variation of the absorption coefficient, which, together with the coefficient of geometric spreading, is a function of depth. Also, the intensity factor b, which is usually taken to be equal to 3, is a variable and a function of the energy absorption at the epicentre. It is shown that magnitudes can be predicted accurately by use of one or preferably by more isoseismal radii calibrated against re‐assessed instrumental magnitudes.
Response of jointed arches to earthquake excitation
Authors: Hall John F. , Dowling Michael J.
Published: March 2007

An efficient method for accurately modelling the gradual opening and closing of joints in two‐dimensional slabs and arches has been devised. The method is used in computing the earthquake response of an arch which is a representative horizontal cross‐section of a concrete arch dam. Responses of the arch with and without joints are compared to assess the effect of joint opening. An extension to three‐dimensional arch dams is proposed.
Determination of parameters for a model for the cyclic behaviour of interfaces
Authors: Drumm E. C. , Desai C. S.
Published: March 2007

The cyclic shear stress‐deformation response of dry sand‐concrete interfaces is described using a modified form of a Ramberg–Osgood (R‐O) model. The model permits the description of the interface secant stiffness as a function of the normal stress, shear stress, sand density and number of loading cycles. Stiffening behaviour, or an increase in secant shear stiffness with number of cycles, may be represented, as well as degradation behaviour.

Typical results from a series of cyclic direct shear tests are presented. A methodology is described by which the parameters for the (R‐O) model can be determined from the laboratory shear tests, and the functional forms of the parameters for the sand‐concrete interface are provided.

The model is verified by predicting the response of two displacement controlled laboratory tests that were used for the determination of the model parameters. An additional verification is presented in which the response is predicted for a test not used in the parameter determination. The model is shown to simulate satisfactorily the cyclic response, including the effect of number of loading cycles.
Limiting performance of shock isolation systems by a modal approach
Authors: Pilkey Walter D. , Kitis Levent
Published: March 2007

The problem of determining the limiting performance of vibrating systems under shock loading is solved by replacing portions of the system by control forces which can represent any design. For the class of problems treated here, the performance index and the constraints are linear combinations of system response variables such as displacements, velocities and accelerations. Furthermore, the equations of motion are linear, so that it is possible to formulate the optimization procedure as a linear programming problem. In expressing the performance index and the constraints as linear functions of the unknown control forces, a modal approach is used to simplify and improve previous treatments of this problem. In spite of these linearity requirements, the control forces are not required to be linear functions of the response variables.
Attenuation of modified mercalli intensity in New Zealand earthquakes
Authors: Dowrick David J.
Published: April 2007

This paper describes a comprehensive study of the attenuation of Modified Mercalli intensity in New Zealand earthquakes, which has resulted in significantly different and new findings when compared with those of earlier work. The current study used recently revised magnitudes for the 30 events in the carefully selected data set. Magnitudes ranged from ML = 5.0 to Ms = 7.8. Special effort was also put into establishing the depths of the events, which ranged from very shallow to 65 km. An expression of a form also used in peak ground acceleration attenuation studies was adopted, I = a + bM + cr + dlog10r with r being taken as the mean distance from the centre of the fault rupture surface to each isoseismal. A two‐step stratified regression analysis was used because it results in more realistic estimates of standard errors, although its mean curves were virtually the same as those derived from the standard one‐step method. It was found possible to model accurately the attenuation of the deepest events from regressions of the data of the shallowest events, but the inverse was not true. In a study of the influence of source mechanisms it was found that the attenuation was the same for events with normal and strike‐slip faulting. In contrast, events with reverse fault mechanisms were found to have higher intensities (for the same M and r) than normal and strike‐slip events, by a factor corresponding to that found by Campbell in a study of peak ground accelerations, although the statistical test was narrowly short of the conventional significance level.
The seismic behaviour of cross‐braced steel frames
Authors: Wijanto L. S. , Moss P. J. , Carr A. J.
Published: April 2007

Analytical studies on the inelastic behaviour of concentrically braced steel frames for low‐rise buildings are described in this paper. The bracing members which provide energy dissipation were used to provide information on the ductility levels that are likely to occur under differing levels of earthquake excitation.

An indication of the relative performance of cross bracing is provided in terms of suitable SM values for use in the seismic provisions of New Zealand loadings code NZS 4203.
Response spectral ratios
Authors: Rosenblueth Emilio , Arciniega Alejandra
Published: April 2007

At many sites on soft ground, spectral ratios (ratios of smoothed Fourier amplitude spectral ordinates at the site to those at a station on firm ground) for distant earthquakes are little sensitive to focal mechanism and coordinates and to magnitude. Spectral ratios furnish directly expected Fourier amplitude spectral ordinates at the site of interest. The corresponding response spectra can be estimated through the use of random vibration theory. This step is obviated by resorting directly to ratios of response spectral ordinates. Through comparisons for several sites on the Valley of Mexico we find that these ratios are as stable as those of Fourier amplitude spectral ordinates.
Attenuation of peak ground acceleration in central california from observations of the 17 october, 1989 Loma Prieta earthquake
Authors: Niazi M. , Mortgat C. P. , Schneider J. F.
Published: April 2007

The strong ground motion produced by the 17 October, 1989 Loma Prieta earthquake in northern California was recorded at over 100 stations. Accelerograms were generated at sites with significantly different geology, including land fill and soft sedimentary soil sites. In this study, the attenuation characteristics of the peak vertical and horizontal ground accelerations are studied for freefield recording conditions within 100 km of the source by the application of a non‐linear multi‐regression procedure. Two sets of attenuation models for weighted and unweighted observations are compared with those reported by other investigators for this earthquake and for regional and worldwide data. The peak ground acceleration (PGA) observations for this earthquake exceed previous predictions of standard attenuation models, particularly beyond 30 km (approximately 60 percent at 50 km). Higher attenuation of the vertical component compared to the horizontal is confirmed.

The regression considers site geology as an independent parameter. Soil sites display as much as 23 per cent amplification relative to rock sites for horizontal PGA and as much as 40 per cent for vertical PGA. Amplification of the ground motion at sites characterized by soft soil geology is examined by comparing the recorded PGA with the corresponding prediction at sites underlain by stiff soil. Eight of ten of the soft soil sites display significant amplification relative to stiff soil sites (as much as 300 per cent for horizontal and 200 per cent for vertical components). Particular attention is paid to the so‐called anomalous observations at distances beyond 50 km. The anomalous observations between 50 and 80 km may be attributed to various factors such as geology, basic geometry, azimuthal dependence, source mechanism and normal scatter of observations.
Inclusion of higher modes in the analysis of non‐classically damped systems
Authors: Kulkarni Shrikrishna M. , Ng S. F.
Published: April 2007

A time‐integration procedure for dynamic analysis of non‐classically damped systems, in which high‐frequency modes play a significant role, is suggested. This procedure is an extension of Clough and Mojtahedi's1 method. Clough and Mojtahedi suggested integration of the transformed coupled equations of motion where the transformation is done using a truncated set of undamped mode‐shapes. The proposed extension consists in adding the response of all the higher modes through a quasistatic analysis. Approximations involved in using such a procedure are examined. Numerical results presented indicate that the proposed extension leads to a significant improvement over Clough and Mojtahedi's method.
Assessment of the accuracy of the newmark method in transient analysis of wave propagation problems
Authors: Wang Yue‐Cong , Murti Viriyawan , Valliappan Somasundaram
Published: April 2007

The Newmark average acceleration method is non‐dissipative and unconditionally stable, but its accuracy in transient analysis of wave propagation problems depends not only on the spatial discretization but also on the temporal discretization. It has been found that the effects of spatial and temporal discretization when considered separately as commonly done, are far from adequate for most transient analysis. A better criterion manipulating the interdependent relationship between mesh size and time‐step magnitude is imperative to achieve sufficiently accurate results of analysis. In this paper, the accuracy of the Newmark method is investigated by considering the two basic sources of errors, namely, numerical amplitude dissipation and velocity dispersion. The effects of both spatial and temporal discretizations are considered. A new technique to describe the characteristics of various frequency spectra is established. A criterion for mesh design and the selection of time‐step magnitude is also proposed based on the combined effects of the amplitude dissipation and velocity dispersion. The efficiency and effectiveness of the proposed criterion are demonstrated using two one‐dimensional wave propagation problems. A two‐dimensional application shows that this criterion is equally applicable to multidimensional problems.
Stochastic earthquake response of secondary systems in base‐isolated structures
Authors: Chen Yu , Ahmadi Goodarz
Published: April 2007

This paper studies the stochastic responses of secondary systems in base‐isolated shear beam structures. A number of base isolation systems such as the laminated rubber bearing (LRB), the resilient‐friction base isolator (R‐FBI) with or without sliding upper plate, and the EDF system are considered. The stochastic models for the El Centro 1940 and the Mexico City 1985 earthquakes which preserve the non‐stationary evolutions of amplitude and frequency content of ground accelerations are used as earthquake excitations. The technique of equivalent linearization is utilized and the mean‐square response statistics of secondary systems and primary structure are evaluated. The accuracy of the linearization scheme is verified by comparison with the Monte Carlo simulation results. Statistically estimated peak responses of the secondary system are evaluated and the results are compared with the response spectra for actual earthquake accelerograms. It is shown that the use of base isolation systems, generally, provides considerable protection for structural contents. In particular, the LRB system is remarkably effective in reducing responses of secondary systems. Results for the Mexico City earthquake show that the base‐isolated structures are sensitive to long period ground excitations.
A modified static procedure for the design of torsionally unbalanced multistorey frame buildings
Authors: Chandler A. M. , Duan X. N.
Published: April 2007

Seismic building codes include design provisions to account for the torsional effects arising in torsionally unbalanced (asymmetric) buildings. These provisions are based on two alternative analytical procedures for determining the design load for the individual resisting structural elements. A previous study has shown that the linear elastic modal analysis procedure may not lead to conservative designs, even for multistorey buildings with regular asymmetry, when such structures are excited well into the inelastic range of response. The equivalent static force procedure as recommended by codes may also be deficient in accounting for additional ductility demand in the critical stiff‐edge elements. This paper addresses the non‐conservatism of existing static torsional provisions and examines aspects of element strength distribution and its influence on inelastic torsional effects. A recommendation is made for improving the effectiveness of the code‐type static force procedure for torsionally unbalanced multistorey frame buildings with regular asymmetry, leading to a design approach which estimates conservatively the peak ductility demand of edge elements on both sides of the building. The modified approach also retains the simplicity of existing code provisions and results in acceptable levels of additional lateral design strength. It has recently been adopted by the new Australian earthquake code, which is due to be implemented early in 1993.
Cone models for nearly incompressible soil
Authors: Meek Jethro W. , Wolf John P.
Published: April 2007

Cones can be used to model soil in a unified strength‐of‐materials approach. For the vertical and rocking motions involving predominantly compressional‐extensional deformation, the corresponding dilatational wave velocity tends to infinity for Poisson's ratio approaching 1/2. Based on the rigorous solution for the dynamic stiffness of a rigid disk for all frequencies, whereby the partition of the power among P‐, S‐ and Rayleigh waves is also discussed, two special features are necessary for the vertical and rocking motions for nearly incompressible soil with Poisson's ratio between 1/3 and 1/2: (1) The appropriate wave velocity is selected as twice the shear wave velocity and not as the dilatational wave velocity; (2) A trapped mass which increases linearly with Poisson's ratio is introduced. The trapped mass can be assigned to the base mat, allowing the cone model to be constructed in the same way for all Poisson's ratios. The realization of cone models for surface foundations on a homogeneous half‐space and on a layer on a flexible half‐space and for embedded and pile foundations is addressed.
Why cone models can represent the elastic half‐space
Authors: Meek Jethro W. , Wolf John P.
Published: April 2007

In lieu of the rigorous elastodynamical approach, many problems in foundation dynamics may be solved quite accurately via simple cone models of the soil. Although these cone models are amenable to very simple analysis, they have not yet been widely accepted in engineering practice. The reservations against their use are possibly due to the fact that cones are based on non‐rigorous strength‐of‐materials assumptions, they neglect large portions of the half‐space, and cannot represent Rayleigh surface waves. These potential objections are investigated step by step and proven to be unfounded. It turns out that cone models indeed incorporate and provide valuable insight into all the salient features of rigorous solutions; the aspects omitted by cones are revealed to be of minor physical importance.
Damage costs for commercial and industrial property as a function of intensity in the 1987 Edgecumbe earthquake
Authors: Dowrick David J. , Rhoades David A.
Published: April 2007

This paper describes an analysis of damage costs to commercial and industrial property, including buildings (all low‐rise), their contents, equipment and stock, in the Ms = 6.6 Edgecumbe New Zealand earthquake of 2 March 1987. The damage costs were converted to damage ratios by dividing by the value of the relevant property item. For the MM7 and MM9 intensity zones, the mean values and statistical distributions of these damage ratios were then found, the lognormal distribution fitting well.

For all commercial and industrial buildings in the MM intensity IX zone (centroid MM9‐4) the mean damage ratio was 0.076. The mean damage ratios were generally much smaller than estimated in previous studies. The buildings were all low‐rise. There was no correlation between building and equipment damage ratios on a building by building basis. Considering dates of construction, it appears that mean damage levels at MM9 have not changed significantly for postcode buildings through changes in design standards up to the 1980s.
An internal variable approach applied to the dynamic analysis of elastic–plastic structural systems
Authors: Rajgelj S. , Amadio C. , Nappi A.
Published: April 2007

Discrete elastic–plastic systems subjected to dynamic load conditions are considered and properties related to an implicit time‐integration scheme are discussed on the basis of an internal variable formulation. The material models accounted for are quite general: elastic–perfectly plastic and elastic–plastic (subjected to linear or non‐linear, kinematic or isotropic hardening). The internal variable approach adopted in the paper leads easily to extremum theorems from which convergence properties of convenient time‐integration schemes immediately follow. Next, taking account of the stabilising effect due to inertial and damping forces, it is shown how the above results can be extended to the case of softening (again linear or non‐linear, kinematic or isotropic). Finally, some numerical examples are given and an extension to damage models is envisaged.
Dynamic impedances of a weakly anelastic medium
Authors: Sienkiewicz Zbigniew
Published: April 2007

Approximate formulas are derived to evaluate in the frequency domain the dynamic impedances of a weakly anelastic medium based on its pure elastic behaviour. The correspondence principle is applied to the elastic solution of a boundary‐value problem followed by the expansion of the anelastic solution in a Taylor series about the elastic state. Taking the magnitude of material damping into account (small damping) only the first two terms of the Taylor series have been used. The derivatives of first order in the expansion can be determined by the central difference approximation; this requires only the evaluation of differences between neighbouring elastic solutions.
An analytical solution for the probabilistic response of sdof non‐linear random systems subjected to variable amplitude cyclic loading
Authors: Manzocchi G. M. E. , Chryssanthopoulos M. , Elnashai A. S.
Published: April 2007

Design for a specific ductile failure mode is assuming a rǒle of increasing importance for earthquake‐resistant structures. This necessitates an accurate assessment of the distribution of overstrength in the structure, in order that the predefined failure mode can be realized. Consequently, the variability of the response for a given variability in the salient material properties, such as yield strength for steel structures, should be assessed and accounted for. In this paper an analytical method is proposed for the evaluation of the probability density function of the response of a single‐degree‐of‐freedom hysteretic system with random parameters subject to a variable amplitude cyclic load history. A simple algorithm is derived which may be used to obtain the system response as a function of the system parameters. This response function may then be used to evaluate the displacement response probability density function when given the probability density function of the system parameters. Results derived from this procedure are verified against Monte Carlo simulation. It is shown that accurate response statistics are obtained at a fraction of the computing cost of simulation techniques.
Duration of strong ground motion in terms of earthquake magnitude, epicentral distance, site conditions and site geometry
Authors: Novikova E. I. , Trifunac M. D.
Published: April 2007

The physical bases and empirical equations for modelling the duration of strong earthquake ground motion in terms of the earthquake magnitude, the epicentral distance and the geological and local soil site conditions are investigated. At 12 narrow frequency bands, the duration of a function of motion f(t), where f(t) is acceleration, velocity or displacement, is defined as the sum of time intervals during which the integral S f2 (τ) dτ gains a significant portion of its final value. All the records are band‐pass filtered through 12 narrow filters and the duration of strong ground motion is studied separately in these frequency bands. It is shown that the duration of strong motion can be modelled as a sum of the source duration, the prolongation due to propagation effects and the prolongation due to the presence of the sediments and local soils. It is shown how the influence of the magnitude on the duration of strong ground motion becomes progressively stronger, in going from low to moderate frequencies, and that the duration is longer for ‘soft’ than for ‘hard’ propagation paths, at low and at moderate frequencies. At high frequencies, the nature of the broadening of the strong motion portion of the record with increasing distance is different, and is most likely related to the diffraction and scattering of the short waves by the velocity inhomogeneities along the wave path. It is also shown that the geological and local soil conditions should both be included in the model. The duration can be prolonged by 3–5 sec at a site on a deep sedimentary layer at frequencies near 0.5 Hz, and by as much as 5–6 sec by the presence of soft soil underneath the station, at a frequency of about 1 Hz. An empirical equation for a probabilistic estimate of the discrepancies of the predictions by our models relative to the observed data (distribution function of the residuals) is presented.
A microslip model for the seismic response analysis of drained cohesionless soil deposits
Authors: Gambarotta Luigi , Lagomarsino Sergio
Published: April 2007

Constitutive equations for drained cohesionless soils under triaxial stress states, based on a microslip model with internal friction, are proposed and applied to the analysis of the seismic response of soil deposits. The microslips, assumed localized in the discontinuity surfaces passing through the particle‐to‐particle contacts, describe the effects of the sliding and rolling between grains of sand. Once the response of the model under cyclic shearing stresses and strains superimposed on the geostatic stress state has been analysed, the constitutive equations are applied to a one‐dimensional shear model for the dynamic analysis of the layered deposits. An application to an instrumented soil deposit is then developed, the experimental results of which refer to both strong and weak motion earthquakes; the comparisons between the experimental and theoretical results point out the peculiarities and validity limits of the model. The model here developed may be applied also to the analysis of two‐ and three‐dimensional sites.
Hybrid structural control using viscoelastic dampers and active control systems
Authors: Tzan Shyh‐Rong , Pantelides C. P.
Published: April 2007

Viscoelastic (VE) dampers and active control (AC) systems are studied together as a hybrid system for their effectiveness in reducing the response of seismic structures. VE dampers have properties which are both frequency and temperature‐dependent. On the other hand, AC systems for seismic structures require rather large control forces in order to be effective. The possibility of combining VE dampers and AC systems to improve the performance of both systems is examined. It is found that for the same response reduction, the addition of VE dampers to an AC system reduces the required control forces considerably, which reduces the cost of the AC system. The addition of the AC system helps improve the velocity performance of VE dampers and considerably reduces the possibility of shear failure of the viscoelastic material. Two procedures for evaluating the damping effect of the VE dampers are suggested which can be applied to either shear‐type or framed structures. Two control algorithms based on drift and velocity/acceleration feedback are compared to existing algorithms. A method of determining the weighting matrices of an AC system is presented which reduces the required control forces for certain control algorithms.
The essential oil composition of Bubonium graveolens (Forssk.) Maire from the Algerian Sahara
Authors: Cheriti Abdelkrim , Saad Amel , Belboukhari Nasser , Ghezali Said
Published: April 2007

The chemical compositions of the essential oils from the leaves and flowers of the endemic medicinal plant Bubonium graveolens, collected from south‐western Algeria, were established by GC–MS analysis. A total of 43 compounds were identified, representing, for leaves and flowers respectively, 97% and 97.6% of the total oil composition. 1,8‐Cineole (21.5% in leaves, 16.5% in flowers), δ‐cadinol (19.1% in leaves, 13.9% in flowers) were the major compounds identified. The flower oil was characterized by a high percentage of 2,6‐dimethyl‐1,6‐heptadien‐4‐yl acetate (19.4%) and trans‐chrysanthenyl acetate (18.7%). δ‐Cadinene (12.4%) was detected exclusively in the leaf oil. This is the first report on the chemical compounds of the oil of the B. graveolens. Copyright © 2007 John Wiley & Sons, Ltd.
Fusion gene‐mediated truncation of RUNX1 as a potential mechanism underlying disease progression in the 8p11 myeloproliferative syndrome
Authors: Ågerstam Helena , Lilljebjörn Henrik , Lassen Carin , Swedin Agneta , Richter Johan , Vandenberghe Peter , Johansson Bertil , Fioretos Thoas
Published: March 2007

The 8p11 myeloproliferative syndrome (EMS) is a chronic myeloproliferative disorder molecularly characterized by fusion of various 5′ partner genes to the 3′ part of the fibroblast growth factor receptor 1 (FGFR1) gene at 8p, resulting in constitutive activation of the tyrosine kinase activity contained within FGFR1. EMS is associated with a high risk of transformation to acute myeloid leukemia (AML), but the mechanisms underlying the disease progression are unknown. In the present study, we have investigated a case of EMS harboring a t(8;22)(p11;q11)/BCR‐FGFR1 rearrangement as well as a t(9;21)(q34;q22) at the time of AML transformation. FISH and RT‐PCR analyses revealed that the t(9;21) leads to a fusion gene consisting of the 5′ part of RUNX1 (exons 1–4) fused to repetitive sequences of a gene with unknown function on chromosome 9, adding 70 amino acids to RUNX1 exon 4. The t(9;21) hence results in a truncation of RUNX1. No point mutations were found in the other RUNX1 allele. The most likely functional outcome of the rearrangement was haploinsufficiency of RUNX1, which thus may be one mechanism by which EMS transforms to AML. © 2007 Wiley‐Liss, Inc.
The new approach to assignment of ASFA categories—Introduction to the fourth special issue: Clinical applications of therapeutic apheresis
Authors: Szczepiorkowski Zbigniew M. , Shaz Beth H. , Bandarenko Nicholas , Winters Jeffrey L.
Published: March 2007

The American Society for Apheresis (ASFA) Apheresis Applications Committee is responsible for a review and categorization of indications for therapeutic apheresis. The results of the review process were previously published in 1986, 1993, and 2000 as the ASFA Special Issues. The ASFA categories consist of categories I through IV, and category P (pending). This article describes the novel methodology, based on structured systematic review of the published literature, used to assign categories for indications for therapeutic apheresis. This is the first time each entity is presented as a fact sheet, which summarizes the evidence for the use of therapeutic apheresis. A detailed description of the fact sheet format and the individual fact sheets for categories I through III and category P are presented in the main article of this Special Issue. The diseases assigned to category IV are discussed in a separate article in this issue. Information on how the Apheresis Applications Committee proposes to include new diseases for category assignment is also provided. J. Clin. Apheresis., 2007 © 2007 Wiley‐Liss, Inc.
Overexpression of integrin β1 inhibits proliferation of hepatocellular carcinoma cell SMMC‐7721 through preventing Skp2‐dependent degradation of p27 via PI3K pathway
Authors: Fu Yi , Fang Zhengyu , Liang Yulong , Zhu Xiaodong , Prins Peterbram , Li Zengxia , Wang Liying , Sun Lidong , Jin Jiawei , Yang Yong , Zha Xiliang
Published: April 2007

Integrins may play important roles in many cellular events, such as cell proliferation, differentiation, and apoptosis. We showed previously that overexpression of integrin β1 inhibits cell proliferation in SMMC‐7721 cells. Here we reported that one of the cyclin‐dependent kinase (CDK) inhibitors, p27Kip1 was involved in proliferation–inhibition induced by overexpression of integrin β1. Overexpression of integrin β1 upregulated p27Kip1 at the protein level, but not mRNA level. The knock‐down of p27Kip1 expression restored cell growth in integrin β1‐overexpressing cells. Cycloheximide (Chx) treatment and pulse‐chase experiments revealed that overexpression of integrin β1 prolonged the half‐life of p27Kip1 by inhibiting its degradation. Proteasome inhibitor (MG132) treatment of the cells indicated that proteasome mediated degradation of p27, and Skp2‐dependent degradation might be prevented. Overexpression of integrin β1 decreased Skp2 at mRNA level, which was regulated by cell adhesion and the subsequent adhesion‐dependent signaling. Overexpression of integrin β1 reduced cell adhesion, accordingly, inactivated the phosphoinositide 3‐kinase (PI3K) signaling. PI3K inhibitor LY294002 upregulated p27Kip1 at post‐translational level and downregulate Skp2 at mRNA level, which could mimic the effects of integrin β1 overexpression on p27Kip1 and Skp2. Together, these results suggested that overexpression of integrin β1 inhibited cell proliferation by preventing the Skp2‐dependent degradation of p27Kip1 via PI3K pathway. J. Cell. Biochem. 102: 704–718, 2007. © 2007 Wiley‐Liss, Inc.
Aerated and rotated mode decolorization of a textile dye solution by native and modified mycelial biomass of Trametes versicolor
Authors: Binupriya A R , Sathishkumar M , Kavitha D , Swaminathan K , Yun S E
Published: April 2007

Aerated and rotated mode adsorption experiments were carried out for the removal of a textile dye (reactive blue MR) from aqueous solution using native and pre‐treated biomass of Trametes versicolor. The effect of process parameters like contact time, dosage of adsorbent and adsorbate and pH on adsorption was investigated. The higher the dye concentration, the lower was the adsorption. Increase in biomass dosage increased the adsorption. Kinetic study showed that the adsorption of dye on fungal biomass was a gradual process, and a second‐order kinetic model fitted the present experimental data well. Experimental data were analyzed using Langmuir and Temkin et seq isotherms. Acidic pH was favorable for adsorption. Studies on pH effect and desorption show that chemisorption seems to play a major role in the adsorption process. Of the native and pre‐treated biomass studied, autoclaved biomass showed a better adsorption capacity. The adsorption capacity of autoclaved biomass in aerated mode was found to be 50.51 mg g−1. Aerated mode showed a better adsorption capacity than rotated mode. Copyright © 2007 Society of Chemical Industry
Early Posttransplantation Portal Vein Stenosis Following Living Donor Liver Transplantation
Authors: Ko Gi-Young , Sung Kyu-Bo , Yoon Hyun-Ki , Lee SungGyu
Published: March 2007

Surgical treatments have usually been preferred for early posttransplantation portal inflow abnormalities. However, these treatments are limited due to their technical difficulty and multiple complicating factors. The present study reports the efficacy and safety of percutaneous transhepatic primary stent placement to treat early posttransplantation (≤1 month) portal vein (PV) stenosis. A total of 9 patients who had undergone living donor liver transplantation underwent percutaneous stent placement to treat PV stenosis. The average interval between liver transplantation and stent placement was 13 ± 10 days. Technical and clinical success was obtained in 7 (77.8%) of the 9 patients. Of the 7 patients with clinical success, 1 died of cerebral hemorrhage within 1 month following stent placement. The remaining 6 patients have remained healthy and without recurrence of PV stenosis until the time this manuscript was completed, and follow-up Doppler ultrasound (US) or computed tomography (CT) obtained 66.6 ± 16.1 months after stent placement revealed patent portal inflow in all of these 6 patients. Major complications occurred in 3 patients, i.e., 2 cases of hemoperitoneum caused by blood oozing from a transhepatic tract of the liver grafts and 1 case of intrahepatic pseudoaneurysm. These complications were successfully treated using surgical ligation (n = 2) or transarterial coil embolization (n = 1). In conclusion, although we did experience some procedural complications, the percutaneous transhepatic primary stent placements in our study showed acceptable technical and clinical results for treating early posttransplantation PV stenosis. In addition, long-term PV patency following stent placement was excellent. However, additional experience and further studies will be needed to verify the usefulness of primary stent placement in the early posttransplantation period. Liver Transpl 13:530–536, 2007. © 2007 AASLD.
Distinct Effects of Surgical Denervation on Hepatic Perfusion, Bowel Ischemia, and Oxidative Stress in Brain Dead and Living Donor Porcine Models
Authors: Golling Markus , Jahnke Cosima , Fonouni Hamidreza , Ahmadi Rezvan , Urbaschek Renate , Breitkreutz Raoul , Schemmer Peter , Kraus Thomas W. , Gebhard Martha M. , Büchler Markus W. , Mehrabi Arianeb
Published: March 2007

The liver function and perfusion following brain death is mainly influenced by the sympathetic nerves and hormones. We examined the specific influence of surgical liver denervation on systemic and hepatic perfusion parameters, bowel ischemia and oxidative stress in hemodynamically stable BD and control (living donor [LD]) pigs. Brain death was induced in 8 pigs via saline infusion into the balloon of an epidural Tieman-catheter (1 mL/15 minutes) and compared to the control group (n = 6) over 4 hours. At 2 hours postoperatively, complete liver denervation was initiated. We analyzed systemic cardiocirculatory parameters (mean arterial pressure, aortic flow, bowel ischemia (endotoxin, and endotoxin-neutralizing capacity) and oxidative stress (total glutathione in erythrocytes [tGSHE]) and compared them to local/hepatic perfusion parameters (hepatic artery and portal venous flow, liver blood flow index, and microperfusion), local bowel ischemia (intramucosal pH [pHi] of stomach [pHiS]/colon[pHiC]), and liver oxidative stress (glutathione [rGSHL, GSSGL]). Following brain death, the parameters including mean arterial pressure, aortic flow, pHi, endotoxin, and tGSHE showed no significant changes at 2 hours. Portal venous flow and microperfusion were decreased significantly and hepatic arterial buffer response was ineffective. Hepatic oxidative stress was increased in BD animals (↓rGSHL, ↑GSSGL). Surgical denervation/manipulation increased portal venous flow significantly, hepatic arterial buffer response became effective, and stomach pHi decreased (BD and LD groups). Hepatic oxidative stress was reduced in the BD group (↑rGSHL/GSSGL; P < 0.001) while it was increased in the LD group (↓rGSHL/GSSGL; P < 0.001). In conclusion, denervation reduces hepatic oxidative stress in BD only in contrast to the LD. The reciprocal effect of denervation depends on the state of neural activation and postulates a potential benefit of surgical denervation before organ harvesting in brain death. Liver Transpl 13:607–617, 2007. © 2007 AASLD.
Anesthesia Care for Adult Live Donor Hepatectomy
Authors: Chhibber Ashwani , Dziak Jason , Kolano Jefferey , Norton Russell J. , Lustik Stewart
Published: March 2007

A total of 100 patients who underwent elective lobar donor hepatectomy from 2000 to 2002 at the University of Rochester Medical Center were reviewed. Assessed clinical data were estimated blood loss, intraoperative central venous pressure (CVP), blood product and fluid administration, perioperative arterial blood gas tension and acid-base state, metabolic status, perioperative serum levels of aspartate aminotransferase, alanine aminotransferase, prothrombin time, albumin, and lactate, procedure duration, and perioperative complications. All patients survived surgery, and the average duration of surgery (from skin incision to skin closure) was 615 ± 99.6 minutes. Mean blood loss was 549 ± 391 mL (range, 80-2,500 mL), and only 4 patients required homologous blood transfusion. The intraoperative blood loss did not correlate with CVP values. A total of 72 patients received isotonic sodium bicarbonate solution, and their metabolic variables were superior to those of normal saline group patients (arterial pH, 7.35 ± 0.03 vs. 7.29 ± 0.07; base excess, −4.3 ± 2.4 vs. 7.3 ± 3.4; and serum bicarbonate level, 20.6 ± 2.2 vs. 18.6 ± 2.9). However, the better control of metabolic acidosis was not associated with serum lactate levels or other outcome measures. Maintaining the CVP < 5 mmHg was not associated with blood loss. Clinically significant anesthetic complications were severe metabolic acidosis, pneumothorax and respiratory insufficiency immediately following extubation in the operating room. In conclusion, placement of a thoracic epidural catheter delivering a local anesthetic in addition to intravenous (IV) patient-controlled analgesia with opiates provided safe and effective pain control in most patients. Further prospective studies should shed a light on the optimal care of patients undergoing liver donor hepatic resection. Liver Transpl 13:537–542, 2007. © 2007 AASLD.
The solution of some integral equations
Authors: Lowndes J. S. , Meister E.
Published: March 2007

Using some elementary generalisations of the Erdélyi‐Kober operators of fractional integration the solutions of some general integral equations are obtained in concise forms from which the solutions of several well known examples of the equations are easily found.
Picture reconstruction from projections in restricted range
Authors: Louis A. K. , Törnig W.
Published: March 2007

In order to reduce scanning time modern x‐ray scanners provide projections only in a restricted range [0, ϕ] with ϕ < π. We consider the reconstruction of pictures from p + 1 complete projections in [0, ϕ]. An extrapolation procedure is given to achieve approximations gp of the data in the whole range. We show that the L2‐error of the corresponding picture is of order p−α if the original belongs to the Sobolev space Hoα. The validity of our error estimate is investigated by numerical experiments.
A linear Uzawa‐algorithm for the steady‐state Navier‐Stokes problem
Authors: Hebeker F.‐K. , Martensen E.
Published: March 2007

An Uzawa algorithm of Temam is improved so that the Navier‐Stokes boundary value problem is reduced to a sequence of linear Poisson problems. A simple finite element method is shown to give a convergent sequence of approximate solutions. Finally a penalty variant is discussed.
Bifurcation problems for discrete variational inequalities
Authors: Mittelmann H. D. , Törnig W.
Published: March 2007

The buckling of a beam or a plate which is subject to obstacles is typical for the variational inequalities that are considered here. Birfurcation is known to occur from the first eigenvalue of the linearized problem. For a discretization the bifurcation point and the bifurcating branches may be obtained by solving a constrained optimization problem. An algorithm is proposed and its convergence is proved. The buckling of a clamped beam subject to point obstacles is considered in the continuous case and some numerical results for this problem are presented.
Reconfigurable antenna for wideband code division multiple access and Korean satellite digital multimedia broadcasting controlled by pin‐diodes
Authors: Lee Jeong‐An , Byun Seung‐Bok , Lim Jong‐Hyuk , Yun Tae‐Yeoul
Published: March 2007

A reconfigurable microstrip‐patch antenna with a frequency‐diversity function is presented. This antenna has a simple structure, consisting of a square radiating‐patch, PIN‐diodes, a parasitic patch, and a probe feed. The proposed antenna, using the PIN‐diode's on and off modes, can select either a band of wideband code division multiple access (WCDMA) over a range of 2110–2170 MHz or Korean satellite digital multimedia broadcasting (DMB) over a range of 2630–2655 MHz. By inserting a slot on an additional parasitic patch, the electrical length is increased and the size of antenna is reduced. The measured data agree very well with the simulation. Radiation patterns show a good shape and have an excellent cross polarization level of less than −20 dB. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1334–1337, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22413
Parallel computing efficiency analysis of BOR‐FDTD code on a Beowulf cluster
Authors: Lu Yongquan , Lu Rui , Che Qing , Su Zhiwu , Yu Wenhua , Mittra Raj
Published: March 2007

In this communication, we investigate the efficiency of a parallel BOR‐FDTD code on a commonly used Beowulf cluster which is connected via an Ethernet or Myrinet networking system. The efficiency of a parallel BOR‐FDTD code is relatively high since it only requires data exchanging between the processors on the subdomain boundary. A satellite reflector antenna is simulated by using the parallel BOR‐FDTD code in order to verify the parallel code we developed. Numerical experiments have demonstrated both software design and networking system play an important role in the efficiency of parallel processing. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1398–1401, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22423
Exponential time differencing FDTD formulation for plasma
Authors: Huang Sh. J.
Published: March 2007

The exponential time differencing (ETD) schemes are proposed for transient propagation in dynamic collision plasmas using finite‐difference time‐domain method. The formulation of ETD algorithms with the first order and second accuracy is presented. The ETD algorithms are validated by comparing the simulation results with analytical values. The numerical results indicate that the ETD schemes are accurate and efficient. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1363–1364, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22424
Periodic Green's function for skewed 3‐D lattices using the Ewald transformation
Authors: Stevanoviæ Ivica , Mosig Juan R.
Published: March 2007

We apply the Ewald acceleration technique to the efficient evaluation of periodic Green's functions (GFs) for 3‐D skewed lattices like those arising in electromagnetic/photonic band‐gap (EBG/PBG) structures and metamaterials (MTMs). We develop the expression for the optimal value of an associated splitting parameter, derive the gradient of the scalar potential GFs and address the extraction of singularity for both vector/scalar potential GF and their curl/gradient. Several numerical implementation issues are also discussed leading to further enhancement in computational speed, accuracy, and numerical stability. Finally, the accuracy of the developed GFs is verified against well established algorithms. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1353–1357, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22429