bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of elongation factor‐1α as a Ca2+/calmodulin‐binding protein in Tetrahymena cilia
Authors: Ueno Hironori , Gonda Kohsuke , Takeda Tetsuya , Numata Osamu
Published: April 2003

Calmodulin (CaM) is known to be a ciliary component. However, the function of CaM in cilia or flagella has not been well understood. Immunoelectron microscopy using anti‐CaM antibody showed that CaM was localized on the axonemal microtubules (MTs) and matrix of Tetrahymena cilia. To investigate the signal transduction of Ca2+/CaM in cilia, we performed Ca2+/CaM‐affinity column chromatography in the membrane and matrix fraction. Elongation factor‐1α (EF‐1α) was identified as a Ca2+/CaM‐binding protein in cilia. EF‐1α is a highly conserved protein and functions in protein translation. In addition, EF‐1α has been reported to interact with MTs and F‐actin in several organisms. Immunoelectron microscopy showed that EF‐1α was localized on the axonemal MTs. However, in immunoblot analysis, EF‐1α was mainly extracted in the membrane and matrix fraction from the axonemal MTs by 1% Triton X‐100 extraction. These results suggest that interaction between EF‐1α and axonemal MTs is weak and sensitive to treatment with 1% Triton X‐100 and that EF‐1α mediates between axonemal MTs and CaM in the presence of Ca2+. Moreover, EF‐1α was also localized in cilia of Paramecium, suggesting that EF‐1α functions as a target protein of Ca2+/CaM in ciliate cilia. Cell Motil. Cytoskeleton 55:51–60, 2003. © 2003 Wiley‐Liss, Inc.
Skeletal muscle myosin cross‐bridge cycling is necessary for myofibrillogenesis
Authors: Ramachandran Indu , Terry Monica , Ferrari Michael B.
Published: April 2003

A major stimulus affecting myofibrillogenesis in both embryonic and mature striated muscle is contractile activity. There are two major signals associated with contractile activity: a physiological signal, the transient increase in intracellular calcium, and a physical signal, the transient increase in tension production. However, dissociating these two signals to examine their relative contributions to myofibrillogenesis has proven difficult. In this study, we have used two different myosin inhibitors to determine the importance of myosin cross‐bridge cycling in sarcomere assembly. We find that the small‐molecule inhibitor 2,3‐butanedione monoxime (BDM), which inhibits myosin ATPase, disrupts myofibrillogenesis in amphibian myocytes, consistent with results from avian studies. However, BDM is a weak myosin inhibitor and it is non‐specific; concentrations that inhibit contraction and disrupt myofibrillogenesis also disrupt calcium signaling. Therefore, we also used the recently identified skeletal muscle myosin II inhibitor, N‐benzyl‐p‐toluenesulphonamide (BTS), which has high affinity and specificity for skeletal muscle fast myosin. BTS inhibits contraction and results in myofibrillar disruption that phenocopies our results with BDM. However, BTS does not affect either spontaneous or induced calcium transients. Furthermore, BTS is reversible and does not significantly affect the expression levels of myosin or actin. Thus, our convergent results with BDM and BTS suggest that sarcomere assembly depends on active regulation of tension in the forming myofibril. Cell Motil. Cytoskeleton 55:61–72, 2003. © 2003 Wiley‐Liss, Inc.
How do you write “yes”?: A study on the effectiveness of online dispute resolution
Authors: Hammond Anne‐Marie G.
Published: April 2003

This article is derived from original research into the applicability and effectiveness of online dispute
resolution, particularly mediation, for resolving disputes in the real and virtual worlds. It records the
experience of a variety of mediators and disputants in fifteen online mediation simulations, using eight
different dispute scenarios, some of them multiparty, in consumer transactions, insurance claims, and workplace
and family cases. The objective of the study was to seek answers to the questions: How can online communications
be organized and managed so that parties have the greatest possible opportunity to achieve a mutually beneficial
agreement? What behaviors, skills, strategies, and techniques will most enhance effective
communications? What is required in an online process to effectively facilitate communications and enable
the resolution of disputes?
Mediation, power, and cultural difference
Authors: Brigg Morgan
Published: April 2003

In Western mediation practice, conflict and violence are typically seen as destructive and unhelpful ways of
being, and this does not allow for the constitutive and productive role of conflict in many non‐Western
traditions. The playing out of these assumptions in mediation practice effects an operation of power that is
particularly significant in intercultural mediations. Explicit and implicit mediator techniques lead disputants
in intercultural mediations to behave in ways consistent with the goals of mediation and Western norms around
conflict and selfhood. The specificity of this analysis means that the findings are indicative and explorative
rather than comprehensive. Nevertheless, the results highlight the need to consider ways in which researchers
and mediators can begin to mitigate this operation of power and respond to cultural difference in ethical
ways.
Victims, targets, protectors, and destroyers: Using disputant accounts to develop a grounded taxonomy of disputant orientations
Authors: Harrison Tyler R.
Published: April 2003

Studies of dispute resolution have generally neglected the perspective of the disputant in favor of the
perspective of the dispute handler. Exit, voice, loyalty, and neglect studies have addressed some of the
circumstances under which individuals give voice to their grievances, but these have generally neglected the
area of voice beyond offering predictions of when it will be used. This paper examines how forty‐five
disputants express voice as they pursue grievances through an ombud's office. The data yielded a grounded
taxonomy of disputant motivations with placement of blame and desired outcome as underlying dimensions. Seven
categories of disputants emerged from the data: information seekers, exception seekers, victims, enforcers,
protectors, targets, and destroyers. In addition to expanding our understanding of voice, the focus of this
research on disputant accounts, motives, and desired courses of action has implications for the strategies
dispute handlers choose in managing grievances and may lead to the development of better organizational
disputing systems.
Balancing on words: Human change processes in mediation
Authors: Hoskins Marie L. , Stoltz Jo‐Anne M.
Published: April 2003

Mediation literature has been devoted to developing strategies to help people resolve differences. But within
this prolific body of knowledge, few studies explore the subjective experience that people engage in while
trying to bridge differences. This article reports the findings of a study conducted to understand the processes
of change from the perspective of those who experienced significant changes following formal mediation. All of
the participants had experienced long‐term conflict in the workplace. Three to six months after the
mediation, the participants were asked to describe how the process has affected their beliefs, values,
expectations, and behaviors within the conflicted relationships and to reflect on how they had changed since the
mediation. Implications for mediators are included.
Type I and Type II errors in culturally sensitive conflict resolution practice
Authors: Avruch Kevin
Published: April 2003

Drawing on recent, critical work dealing with culture theory, ethnicity, and multiculturalism, this article seeks to address the nexus between conflict resolution theory and practice and aims primarily to contribute to the work of practitioners functioning as third parties and intervenors in intercultural and interethnic conflicts and disputes. Two conceptions of culture are proposed and analyzed: a technical, “experience‐distant” sense of the term, crucial for conflict analysis (and for education and training); and an affectively laden, often politicized, “experience‐near” sense of the term, at the root of so much intergroup conflict and thus implicated in effective and ethical intercultural practice.
DOA estimation using recursive 2D unitary ESPRIT
Authors: Kuroda Tadaaki , Kikuma Nobuyoshi , Inagaki Naoki
Published: April 2003

In mobile communications, it is important to have a knowledge of the multipath wave propagation environment. It is a very effective means of analysis for this purpose to estimate the signal parameters (such as the direction of arrival) of the individual arriving waves. ESPRIT is considered an interesting parameter estimation method. It is an algorithm in which eigenvalue expansion is iteratively applied to the correlation matrix of the input data, and the parameters are estimated. The method works effectively when the number of array elements is small, but a long time is required to arrive at the estimate when the number of elements is increased. Consequently, this paper extends recursive ESPRIT based on QR decomposition, in which recursive calculation is performed, to 2D estimation. Furthermore, in order to improve computation efficiency and to make estimation pairing easy, recursive 2D unitary ESPRIT is proposed. The complex representation is used as the simplest method of pairing for the estimated signal parameters. Spatial averaging is also introduced. Computer simulations of direction angle and azimuth angle estimation for arriving waves with high correlation are performed. The features of the proposed method are thereby demonstrated from the viewpoints of accuracy of estimation, computation time, and tracking performance. Important results are obtained, which will provide a path to future development. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 67–77, 2003; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/ecja.10036
A polarization diversity antenna using a printed dipole and patch with a hole
Authors: Michishita Naobumi , Arai Hiroyuki
Published: April 2003

This paper proposes a polarization diversity antenna that has a half beam width of 60° in the horizontal plane for use in wireless telephony base stations. Specifically, a printed dipole antenna is used as a vertical polarization element and a patch antenna with a hole is used as a horizontal polarization element. With these two combined, a small diversity antenna is constructed. Also, this antenna is analyzed by means of FDTD, confirming the experimental characteristics and elucidating the effect of the antenna parameters on the half beam width in the horizontal plane. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 57–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10072
Local SAR estimation system using solid phantom and fixed E‐field probe
Authors: Iyama Takahiro , Tarusawa Yoshiaki , Uebayashi Shinji , Nojima Toshio , Fujiwara Osamu
Published: April 2003

We propose a local Specific Absorption Rate (SAR) estimation system using solid phantom and fixed E‐field probe for application to portable wireless devices such as cell phones. This system is constructed from a solid phantom molded from a lossy dielectric and an electric field (E‐field) probe inserted into the phantom. The advantage of this system is the ability to easily measure in a relatively short time the local SAR with measurement deviations of about ±30% compared to the measurements made by the conventional technique using a liquid phantom. First, we perform numerical analysis using the finite‐difference time‐domain (FDTD) method in the basic parameter design to clearly show the effects of the size of the insertion hole for the E‐field probe in the solid phantom and the complex dielectric permittivity on the antenna input impedance and local SAR. Next, we develop a local SAR estimation system using solid phantom and fixed E‐field probe, and measure and evaluate the antenna input impedance and local SAR of two solid phantoms having different complex dielectric permittivities. We confirmed that their properties tend to nearly agree with the calculated results. Finally, we measure the local SARs of 32 portable phones using this system. We confirmed that compared to the measurements by the E‐field probe scanning method, the measurements of about 77% of the phones have deviations within 30%, and the target measurement accuracy during development could almost be achieved. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 46–56, 2003; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/ecja.10082
Analysis of built‐in antennas for handset using human (head, hand, and finger) model
Authors: Morishita Hisashi , Hayashida Syogo , Ito Jun , Fujimoto Kyohei
Published: April 2003

With increasing size reduction and performance enhancement of portable handsets, there is an increasing requirement to conceal the antenna inside the handset package. When a smaller portable handset is actually used, most users hold the handset with the index finger straight. In this paper, the characteristics of the built‐in antennas for the handset are analyzed by an electromagnetic field simulator with the human body (head, hands, and fingers) taken into account so that the effect presented to the antenna by the human body is clarified. The analysis model consists of a human model made of a head and a hand and fingers holding the handset with an antenna attached to a metal box. The built‐in antenna is either the planar inverted F antenna used in practice or the folded loop antenna proposed as a balanced‐feed antenna. The numerical results by the present analysis model agree well with the experimental values and hence the characteristics of the handset antenna including the effect of the human model can be analyzed accurately. By means of this model, the characteristics of the planar inverted F antenna attached to the handset for operation at the frequency of W‐CDMA are computed in comparison with those of the 5/8‐wavelength monopole antenna frequently used in actual handsets. It is found that the radiation efficiency of the planar inverted F antenna is degraded to near 20% due to the effect of the human model including the fingers. In the case of the folded loop antenna, the radiation efficiency is improved by about 10% in comparison with the planar inverted F antenna since no current flows on the metal box. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 35–45, 2003; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/ecja.10085
Modal polarization current model method and its application to scattering by dielectric bodies
Authors: Inoue Takashi , Inagaki Naoki , Kikuma Nobuyoshi
Published: April 2003

The polarization current model method (PCMM), one of the volume integral equation methods, is used for the analysis of antennas involving dielectric materials and of electromagnetic scattering by dielectric bodies. In the conventional PCMM, the subdomain method of moments is often used. Since the number of unknowns needed is proportional to the number of segmentations of the dielectric body, the computation time is long. In this paper, the M‐PCMM method is proposed in which the polarization current density is mode‐expanded in common spherical wave functions in the dielectric body, and its coefficients are used as the unknowns. The number of unknowns is unrelated to the number of segmentations of the dielectric body and is of the same order as that in the modal expansion method. Hence, the computation time can be reduced. In order to study the validity of this method, scattering by a cubic dielectric body is carried out. The analysis results of the M‐PCMM are compared with those of the conventional PCMM. The results of the scattering directivity and the internal electromagnetic fields obtained by the two methods are in agreement, while the M‐PCMM is found to reduce the computation time substantially. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 25–34, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecja.10088
Dual‐mode horn antennas suppressing higher‐order modes
Authors: Deguchi Hiroyuki , Tsuji Mikio , Shigesawa Hiroshi
Published: April 2003

In the dual‐mode conical horn antennas proposed to date, the wave front on the aperture plane becomes spherical, so that the efficiency is degraded due to phase error in the aperture plane. In the present paper, a configuration method is proposed for a new dual‐mode conical horn antenna with an aperture distribution which improves efficiency and at the same time reduces the cross‐polarization components. In the present method, the entire antenna is segmented into many sections by recognizing the cutoff characteristics of a circular waveguide. The shape of each section is successively designed in such a way that only the higher‐order mode newly generated in such a section is controlled. In this way, only the cylindrical mode needed to obtain a low cross‐polarization characteristic is excited, and the higher‐order modes generating spherical wave fronts can be suppressed. The effectiveness of this method is verified by numerical results as well as measurement of the radiation pattern of a test antenna in the X band. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 17–24, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10089
Observations and suppression of sea ice clutter by means of millimeter wave radar
Authors: Sayama Shuji , Sekine Matsuo
Published: April 2003

Sea ice clutter was measured using a millimeter wave radar. To determine the sea ice clutter amplitude, we introduce the Akaike Information Criterion (AIC). It is found that the sea ice clutter amplitude obeys the log‐Weibull distribution which was newly proposed by us for both all data and data within the beam width of an antenna. To suppress such clutter, we have applied the log‐Weibull/CFAR procedure to the observed data. It is shown that radar target embedded in sea ice clutter is detected. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 9–16, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10101
A method of processing inbound IP packets with a routing table
Authors: Jinmei Tatuya , Onoe Atsushi , Yamamoto Kazuhiko , Hagino Jun‐ichiro itojun , Esaki Hiroshi , Murai Jun
Published: April 2003

As the Internet continues to spread and equipment performance improves, the typical operation has been to assign multiple Internet Protocol (IP) addresses to one node. At this type of node, whether the node is the destination of the received packet must be efficiently determined. Conventionally, a Berkeley Software Distribution (BSD) system used an algorithm that performs a linear search for the address of the node. As described in this paper, the Widely Integrated Distributed Environment (WIDE) Project conducted R&D on an improved method using a routing table algorithm. Later an original improvement using a hash table was introduced into Internet Protocol Version 4 (IPv4) implementation in NetBSD and BSD/OS. In this paper, we explain these three methods and evaluate their performances using actual equipment. From the evaluation results, a decision method based on the routing table or the hash table is clearly an improvement over the conventional technique based on a linear search. In addition, the performance of the decision method using the routing table algorithm does not degrade even if the number of addresses increases similar to a conventional routing lookup. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 1–8, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10110
A scalable packet switch with congestion‐reactive priority control
Authors: Shimojo Yoshimitsu , Nakakita Hideaki
Published: April 2003

This paper proposes a packet switch architecture with scalability suitable for handling Internet traffic. The basis of the architecture is a multistage switch consisting of a combination of bufferless unit switches. In the conventional multistage switches, one problem is resistance to hot spots. A hot spot is generated by the best‐effort traffic characteristic of the Internet. In this paper, a method of control of the multistage switch with resistance to hot spots is proposed. Further, mechanisms for facilitating the installation of multistage switches are also proposed, including prevention of out‐of‐sequence transmission of the packets and reduction of the speed‐up factor. The proposed switch architecture is evaluated by simulation and its effectiveness is confirmed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 78–89, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1175
Realization and performance evaluation of a failure‐resistant ATM transport (FRAT) method for high‐quality video transmission services
Authors: Fujihara Kazuhiro , Kanayama Yukihara , Tsuboi Toshinori
Published: April 2003

As video compression technology advances and hardware prices drop, real‐time applications using digital video such as video conferencing systems have been put to practical use. Some of these kinds of applications require extremely high transmission quality such as program distribution for digital TV broadcasting. Various compression methods with a variety of compression rates are used for digital video. Although ATM is suitable for efficiently transmitting these kinds of real‐time signals with a variety of speeds, the implementation of a transmission method that does not allow the video or audio to be interrupted or distorted even when a chance transmission channel failure or bit error occurs is becoming a key issue. Therefore, this paper proposes a method of implementing a “failure‐resistant ATM transport (FRAT) method” for the transmission of high‐quality real‐time applications, which can compensate for random errors without causing information loss even when a transmission channel failure occurs and can prevent buffer underflow at the receiving terminal by minimizing delay variation even if a failure occurs. In addition, this paper shows the effectiveness and characteristics of the proposed method. Specifically, this paper presents an overview of the proposed method and describes the method of implementing it in detail. Also, a trial transmission device based on this implementation method is used to verify the operation of the proposed method, and the characteristics of this device are shown by comparing theoretical values with experimental values for the amount of delay variation, which is considered the most important factor in the transmission of real‐time signals. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 86(9): 90–101, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecja.1176
European chemicals regulation and its effect on innovation: an assessment of the Eu's White Paper on the strategy for a future chemicals policy
Authors: Nordbeck Ralf , Faust Michael
Published: April 2003

In February 2001, the European Commission published its White Paper on a Strategy for a Future Chemicals Policy. The publication launched a heated debate on principles, aims, instruments, implementation and management of future chemicals control in the European Communities. The White Paper came in the wake of massive criticism of current chemicals legislation. Various parties involved repeatedly expressed their concern about a tremendous lack of effectiveness. Furthermore, comparisons with other industrialized countries outside the EU indicated that the current regulatory framework actually discourages innovation in the European chemicals industry. This paper examines current European chemicals policy and main elements of the White Paper strategy with a special focus on the impact of chemicals regulation on innovation towards sustainability. The claim that chemicals regulation tends to block innovation is rejected for lack of conclusive proofs. In contrast, the paper reinforces the view that the White Paper strategy is an important step forward towards sustainability in the chemicals sector. However, with the aim to make it pay for companies to pursue environmentally orientated innovation strategies, supporting measures and instruments need to be developed further. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
The value of Scotland's ecosystem services and natural capital
Authors: Williams Evan , Firn John R. , Kind Vanessa , Roberts Mark , McGlashan Derek
Published: April 2003

Life on earth depends on the ability of the environment to provide essential services. During the 1990s, attempts were made to quantify in monetary terms the benefits that the earth's ecosystem services provide. Costanza et al. (1997a) devised a methodology to assimilate the work of over 100 valuation studies to generate estimates of the monetary value of 17 ecosystem functions for 16 habitat (or biome) types. This work estimated the annual flow of global ecosystem services to be $33 × 1012. In this paper we apply the same methodology to Scotland to derive a current annual ecosystem service value of approximately £17 thousand million ($24 × 109). This is an initial estimate based on the available values. Some modifications to the model are suggested that could produce a more reliable value of Scotland's ecosystem services. Copyright © Crown Copyright 2003. Recorded with the permission of the Controller of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
The politics of recycling—a liberal democratic dilemma?
Authors: Lundmark Carina
Published: April 2003

Implementation of environmental sustainability, such as waste recycling policies, commonly requires people's active involvement. These ideas substantially challenge both established theoretical conceptions and people's daily habits. In this study, political recycling objectives are explored from two branches of political philosophy with different ideas about the proper relationships between individuals and the state—liberalism and communitarianism. Both perspectives are portrayed in traditional and ‘green’ versions, while Sweden provides empirical illustrations, as a liberal democracy with significant communitarian features. Analyses show that increased freedom in other areas (e.g. in the economic field) is used to justify the restrictions in individual freedom that recycling entails. However, the conflict between environmental responsibilities and individual freedom of action crucial to the theoretical debate has little correspondence as Swedish recycling policy is presently being implemented. One set of environmental norms prevails in official documents at national and local levels, and people are anticipated to behave accordingly. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Water pricing and irrigation water demand: economic efficiency versus environmental sustainability
Authors: Massarutto Antonio
Published: April 2003

Irrigation is by far the largest water user in Europe and this is a cause of increasing concern for European environmental policy makers. Insufficient water pricing as well as a subsidy policy that encouraged the development of irrigated crops have been blamed for having favoured an excessive development of water consumption. The policy background is now changing: the reform of the Common Agricultural Policy is gradually reducing the price bonus paid to agricultural commodities, while the Water Framework Directive requires full‐cost recovery to be adopted as the guiding rule for water price setting, thereby reducing or eliminating artificial incentives to develop irrigation. Will this reform achieve the desired effect of fostering sustainable irrigation water use? This paper, based on an original study developed in eight different test areas, suggests that this will not necessarily be the case: irrigation water use will become more efficient (in the sense that water use will be more concentrated on more valuable uses), but this does not necessarily have positive implications in terms of sustainability. Copyright © 2003 John Wiley & Sons, Ltd. and ERP Environment
Effect of earthquake energy input characteristics on hysteretic damper efficiency
Authors: Yamaguchi Hiroki , El‐Abd Ashraf
Published: April 2003

Robust performance of hysteretic dampers, used in controlling mid‐rise buildings, against change of earthquake characteristics is investigated in this paper. A shear type ten‐storey building incorporating hysteretic dampers is studied as a model under the assumption of elastic perfectly plastic behavior for inelastic frame and damper deformations. An energy‐based damper performance index is used to evaluate damper overall efficiency. Thirty‐five earthquake records are applied and the damper strength is optimized for each earthquake record to obtain the maximum performance index or the damper efficiency. Based on the obtained numerical results it is found that, besides the effect of maximum energy input on damper efficiency, other time‐dependant properties such as energy‐based effective duration and earthquake dominant period have great influence on the damper efficiency. A factor (α), which represents the combined effect of maximum energy input, effective duration and dominant earthquake period, is also derived for the prediction of damper efficiency. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of soil degradation during earthquake excitations by Bayesian inference
Authors: Ching Jianye , Glaser Steven D.
Published: April 2003

A Bayesian inference approach is introduced to identify soil degradation behaviours at four downhole array sites. The approach of inference is based on a parametric time‐varying infinite impulse response filter model. The approach is shown to be adaptive to the changes of filter parameters and noise amplitudes. Four sites, including the Lotung (Taiwan), Chiba (Japan), Garner Valley (California), and Treasure Island (California) sites with downhole seismic arrays are analysed. Our results show two major types of soil degradation behaviour: the well‐known strain‐dependent softening, and reduction in stiffness that is not instantaneously recoverable. It is also found that both types of soil degradation are more pronounced in sandy soils than in clayey soils. The mechanism for the second type of soil degradation is not yet clear to the authors and suggested to be further studied. Copyright © 2003 John Wiley & Sons, Ltd.
A unified formulation of the piecewise exact method for inelastic seismic demand analysis including the P‐delta effect
Authors: Aydınoğlu M. N. , Fahjan Y. M.
Published: April 2003

The non‐linear analysis of single‐degree‐of‐freedom (SDOF) systems provides the essential background information for both strength‐based design and displacement‐based evaluation/design methodologies through the development of the inelastic response spectra. The recursive solution procedure called the piecewise exact method, which is efficiently used for the response analysis of linear SDOF systems, is re‐formulated in this paper in a unified format to analyse the non‐linear SDOF systems with multi‐linear hysteresis models. The unified formulation is also capable of handling the P‐delta effect, which generally involves the negative post‐yield stiffness of the hysteresis loops. The attractiveness of the method lies in the fact that it provides the exact solution when the loading time history is composed of piecewise linear segments, a condition that is perfectly satisfied for the earthquake excitation. Based on simple recursive relationships given for positive, negative and zero effective stiffnesses, the unified form of the piecewise exact method proves to be an extremely powerful and probably the best tool for the SDOF inelastic time‐history and response spectrum analysis including the P‐delta effect. A number of examples are presented to demonstrate the implementation of the method. Copyright © 2003 John Wiley & Sons, Ltd.
An experimental study of nominally symmetric and asymmetric structures isolated with the FPS
Authors: de la Llera Juan C. , Almazán José L.
Published: April 2003

This experimental investigation deals with the earthquake behaviour of a nominally symmetric and a mass‐asymmetric three‐storey structural model isolated with the frictional pendulum system (FPS). Both accidental and natural torsion are evaluated in the structure by using recorded accelerations in all building floors and measured deformations at the isolation level. A 3D‐shaking table was used to subject the model to five different ground motions, including impulsive as well as far‐field subduction‐zone type earthquakes. Results show that the analytical predictions of the earthquake behaviour of the isolated structure, as obtained from a physical model of the FPS, are in close agreement with the true complex inelastic measured behaviour of the FPS. Besides, experimental results also validate previous observations about the importance of accounting for the variability of the normal loads in modelling the earthquake behaviour of FPS isolators. Measured torsional deformation amplifications at the base of the building vary, in the mean, from 2.5% to 6% for the symmetric and asymmetric structural configurations, respectively. In relation to the fixed base structure, the reduction factors for the base shear of the isolated structure are, in the mean, about 3.9 for both configurations. Finally, it is concluded that the FPS is capable of controlling the lateral–torsional motions of mass‐asymmetric structures quite effectively by aligning the centre of mass of the superstructure with the centre of pendular and frictional resistance of the isolation system. Copyright © 2003 John Wiley & Sons, Ltd.
Accidental torsion due to overturning in nominally symmetric structures isolated with the FPS
Authors: Almazán José L. , de la Llera Juan C.
Published: April 2003

Overturning of a structure causes variations in the normal loads of the isolators supporting that structure. For frictional isolators, such variation leads to changes in the frictional forces developed and, hence, in the strength distribution in plan. For frictional pendulum system (FPS) isolators, it also causes changes in the pendular action, i.e. in the stiffness distribution of the isolation interface. Therefore, although the structure is nominally symmetric it develops lateral–torsional coupling when it is subjected to two horizontal components of ground motion. This coupling is denoted herein as accidental torsion due to overturning, and its effect in the earthquake response of nominally symmetric structures is evaluated. Several parameters are identified to control this coupling, but the most important are the slenderness of the structure and the aspect ratio of the building plan. Results are presented in terms of the torsional amplification of the deformations of the isolation base and the interstorey deformations of the superstructure. The FPS system is modelled accurately by including true large deformations and the potential uplift and impact of the isolators. Impulsive as well as subduction‐type ground motions are considered in the analysis, but results show small differences between them. An upper bound for the mean‐plus‐one standard deviation values of the torsional amplifications for the base due to this accidental torsion is 5%. This implies that for design purposes of the isolation system such increase in deformations could probably be neglected. However, the same amplification for the interstorey deformations may be as large as 50%, depending on the torsional stiffness and slenderness of the superstructure, and should be considered in design. In general, such amplification of deformations decreases for torsionally stiffer structures and smaller height‐to‐base aspect ratios. Copyright © 2003 John Wiley & Sons, Ltd.
Multiple active–passive tuned mass dampers for structures under the ground acceleration
Authors: Li Chunxiang
Published: April 2003

An Erratum has been published for this article in Earthquake Engineering and Structural Dynamics 2003; 32(15):2451.

Multiple active–passive tuned mass dampers (MAPTMD) consisting of many active–passive tuned mass dampers (APTMDs) with a uniform distribution of natural frequencies have been, for the first time here, proposed for attenuating undesirable oscillations of structures under the ground acceleration. The MAPTMD is manufactured by keeping the stiffness and damping coefficient constant and varying the mass. The control forces in the MAPTMD are generated through keeping the identical displacement and velocity feedback gain and varying the acceleration feedback gain. The structure is represented by the mode‐generalized system corresponding to the specific vibration mode that needs to be controlled. Through minimization of the minimum values of the maximum dynamic magnification factors (DMF) of the structure with the MAPTMD (i.e. through implementation of Min.Min.Max.DMF), the optimum parameters of the MAPTMD are investigated to delineate the influence of the important parameters such as mass ratio, total number, normalized acceleration feedback gain coefficient and system parameter ratio on the effectiveness (i.e. Min.Min.Max.DMF) and robustness of the MAPTMD. The optimum parameters of the MAPTMD include the optimum frequency spacing, average damping ratio and tuning frequency ratio. Additionally, for the sake of comparison, the results for a single APTMD are also taken into account in the present paper. It is demonstrated that the proposed MAPTMD can be employed to significantly reduce the oscillations of structures under the ground acceleration. Also, it is shown that the MAPTMD can render high robustness and has better effectiveness than a single APTMD. In particularly, if and when requiring a large active control force, MAPTMD is more promising for practical implementations on seismically excited structures with respect to a single APTMD. Copyright © 2003 John Wiley & Sons, Ltd.
A rooftop tuned mass damper frame
Authors: Johnson Jerod G. , Reaveley Lawrence D. , Pantelides Chris
Published: April 2003

This article documents the analytical study and feasibility of placing a tuned mass damper in the form of a limber rooftop moment frame atop relatively stiff structures to reduce seismic acceleration response. Six existing structures were analytically studied using a suite of time history and response spectra records. The analyses indicate that adding mass in conjunction with a limber frame results in an increase in the fundamental period of each structure. The fundamental period increase generally results in a decrease in seismic acceleration response for the same time history and response spectra records. Owing to the limber nature of the rooftop frames, non‐linear analysis methods were required to evaluate the stability of the rooftop tuned mass damper frame. The results indicate the addition of a rooftop tuned mass damper frame reduces the seismic acceleration response for most cases although acceleration response can increase if the rooftop frame is not tuned to accommodate the specific structure's dynamic behaviour and localized soil conditions. Appropriate design of the rooftop tuned mass damper frame can result in decreased seismic acceleration response. This translates to safer structures if used as a retrofit measure or a more economical design if used for new construction. Copyright © 2003 John Wiley & Sons, Ltd.
Hematopoietic prostaglandin D synthase is expressed in microglia in the developing postnatal mouse brain
Authors: Mohri Ikuko , Eguchi Naomi , Suzuki Kinuko , Urade Yoshihiro , Taniike Masako
Published: March 2003

Hematopoietic prostaglandin D synthase (HPGDS) is a PGD2‐synthesizing enzyme and is expressed in antigen‐presenting cells, mast cells, and other immunocompetent cells. We here report the HPGDS expression in microglia and the migration pathway of microglia in the developing mouse brain as detected by HPGDS immunohistochemistry. Expression of HPGDS mRNA peaked at postnatal day (PND) 10, decreased gradually thereafter, and reached a plateau at PND 20. The mRNAs for target molecules of PGD2, i.e., DP receptor (DPR) and CRTH2 receptor, showed developmental profiles overlapped to that of HPGDS. Most of the HPGDS+ cells at PND 10 had morphological characteristics of ameboid microglia and gave positive immunostaining with microglia‐specific markers such as RCA‐1, F4/80, or ER‐MP12. These specific markers became less detectable later on, but HPGDS was still expressed even in resting microglia. Thus, HPGDS is a useful marker for investigation of microglial development. Spaciotemporal evaluation of microglial development and migration with HPGDS immunostaining revealed the following three major possible migration pathways of microglia in the postnatal brain: from the lateral ventricle via subventricular zones to brain parenchyma; from the leptomeninges around the cerebellopontine angle to the cerebellar white matter; and from the overlying leptomeninges to the hippocampus, basal forebrain, and brainstem. GLIA 42:263–274, 2003. © 2003 Wiley‐Liss, Inc.
Metallothionein‐I overexpression alters brain inflammation and stimulates brain repair in transgenic mice with astrocyte‐targeted interleukin‐6 expression
Authors: Penkowa Milena , Camats Jordi , Giralt Mercedes , Molinero Amalia , Hernández Joaquín , Carrasco Javier , Campbell Iain L. , Hidalgo Juan
Published: March 2003

Transgenic expression of IL‐6 in the CNS under the control of the GFAP gene promoter, glial fibrillary acidic protein‐interleukin‐6 (GFAP‐IL‐6) mice, raises an inflammatory response and causes significant brain damage. However, the results obtained in the GFAP‐IL‐6 mice after a traumatic brain injury, such as a cryolesion, demonstrate a neuroprotective role of IL‐6. Thus, the GFAP‐IL‐6 mice showed faster tissue repair and decreased oxidative stress and apoptosis compared with control litter‐mate mice. The neuroprotective factors metallothionein‐I+II (MT‐I+II) were upregulated by the cryolesion to a higher extent in the GFAP‐IL‐6 mice, suggesting that they could be related to the neuroprotection afforded by the transgenic expression of IL‐6. To examine this possibility, we have crossed GFAP‐IL‐6 mice with transgenic mice overexpressing MT‐I (TgMT), producing double transgenic GFAP‐IL‐6 TgMT mice. The results obtained after cryolesion in GFAP‐IL‐6 TgMT mice, as well as in TgMT mice, consistently supported the idea that the increased MT‐I+II levels observed in GFAP‐IL‐6 mice are a fundamental and important mechanism for coping with brain damage. Accordingly, MT‐I overexpression regulated the inflammatory response, decreased oxidative stress and apoptosis significantly, and increased brain tissue repair in comparison with either GFAP‐IL‐6 or control litter‐mate mice. Overall, the results demonstrate that brain MT‐I+II proteins are fundamental neuroprotective factors. GLIA 42:287–306, 2003. © 2003 Wiley‐Liss, Inc.
Differential proliferative response in the postischemic hippocampus, temporal cortex, and olfactory bulb of young adult macaque monkeys
Authors: Tonchev Anton B. , Yamashima Tetsumori , Zhao Liang , Okano Hideyuki
Published: March 2003

We investigated the fate of proliferating cells in the adult monkey brain after global ischemia. We used the thymidine analogue bromodeoxyuridine (BrdU) to label S‐phase cells and their progeny in Japanese macaques subjected to global cerebral ischemia for 20 min or to a sham operation. Subsequently, newly generated cells were identified by BrdU immunohistochemistry, and their immunophenotype was determined quantitatively, using specific markers. The ischemic insult significantly increased the number of proliferating cells in the hippocampus and temporal neocortex, where the majority BrdU‐labeled cells expressed markers for microglia (Iba1, CD68, and Ham56) or astrocytes (S‐100β and glial fibrillary acidic protein [GFAP]). In contrast, the proliferation level in the parahippocampal region remained unchanged. This discrepancy prompted us to investigate the postischemic response in the olfactory bulb, a well‐known site of adult cell generation that is anatomically distant from the above‐mentioned regions but that is also subjected to the global ischemic insult. The olfactory bulb contained clusters of proliferating cells expressing markers for neural (Musashi1 and Nestin) and/or neuronal (class III β‐tubulin) progenitors; these were immunophenotypically distinct from other cell types. Their number and distribution were unaltered by ischemia. Our results demonstrate that cell proliferation and differentiation in the adult macaque brain and olfactory bulb are differentially affected by a common insult. GLIA 42:209–224, 2003. © 2003 Wiley‐Liss, Inc.
Role of the Rap1 GTPase in astrocyte growth regulation
Authors: Apicelli Anthony J. , Uhlmann Erik J. , Baldwin Rebecca L. , Ding Hao , Nagy Andras , Guha Abhijit , Gutmann David H.
Published: March 2003

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome in which affected individuals develop nervous system abnormalities that might reflect astrocyte dysfunction. The TSC2 gene product, tuberin, encodes a GTPase‐activating protein (GAP) domain, which regulates the activity of Rap1 in vitro. To determine whether dysregulated Rap1, resulting from TSC2 inactivation, leads to increased astrocyte proliferation in vivo, we generated transgenic mice expressing activated Rap1G12V specifically in astrocytes. We observed no statistically significant difference in the number of astrocytes between wild‐type and GFAP‐Rap1G12V littermates in vivo; however, during log‐phase growth, we observed a 25% increase in GFAP‐Rap1G12V astrocyte doubling times compared to wild‐type controls. This decreased proliferation was associated with delayed MAP kinase, but not AKT, activation. Lastly, to determine whether constitutive Rap1 activation could reverse the increased astrocyte proliferation observed in transgenic mice expressing oncogenic RasG12V, we generated transgenic mice expressing both RasG12V and Rap1G12V in astrocytes. These double transgenic mice showed a striking reversion of the RasG12V astrocyte growth phenotype. Collectively, these results argue that the tumor suppressor properties of tuberin are unlikely to be related to Rap1 inactivation and that Rap1 inhibits mitogenic Ras pathway signaling in astrocytes. GLIA 42:225–234, 2003. © 2003 Wiley‐Liss, Inc.