bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibiting effect of minocycline on the regeneration of peripheral nerves
Authors: Keilhoff Gerburg , Langnaese Kristina , Wolf Gerald , Fansa Hisham
Published: March 2007

The effect of minocycline on nerve regeneration was studied in a rat model of acute sciatic nerve injury, in which the injury was caused by resection and reimplantation of the right sciatic nerve. Immunohistochemical and molecular biological methods, as well as morphometric and electron microscopic techniques, were used. Compared with uninjured and PBS‐treated injured nerves, the minocycline‐treated injured nerve showed: (i) a decrease in macrophage recruitment and activation, probably resulting from inhibition of blood‐brain‐barrier break‐down via reduced MMP2 and MMP9 induction, inhibition of revascularization via additional reduction of VEGF induction, and inhibition of inducible NO synthase (iNOS) induction; (ii) reduced activation of phagocytic Schwann cells, probably by inhibition of iNOS, MMP2 and MMP9 expression; (iii) a slowed Wallerian degeneration; and subsequently, (iv) a diminished nerve regeneration. Macrophages, especially their function in the removal of cellular debris and formation of a microenvironment beneficial for nerve regeneration, are strongly implicated in constructive events after nerve injuries. Therefore, we suggest that additional research into optimizing minocycline intervention for treatment of neurodegenerative diseases is needed before further clinical trials are performed. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Anti‐Müllerian hormone and 11 β‐hydroxylase show reciprocal expression to that of aromatase in the transforming gonad of zebrafish males
Authors: Wang X.G. , Orban L.
Published: March 2007

During development all zebrafish males first develop a “juvenile ovary” that later degenerates and transforms into a testis. In this study, individuals undergoing gonadal transformation were identified from a vas::egfp transgenic line and used for gene expression analysis of anti‐Müllerian hormone (amh), ovarian aromatase (cyp19a1a) and 11β‐hydroxylase (cyp11b, also known as P45011β) by real‐time polymerase chain reaction and in situ hybridization. In the “normal (i.e., nontransforming) juvenile ovary” cyp19a1a was expressed around the oocytes, but cyp11b and amh could not be detected. During gonadal transformation cyp19a1a was down‐regulated and could not be detected anymore; in contrast amh was up‐regulated and highly expressed at similar regions where cyp19a1a had been expressed earlier. Furthermore, the normalized transcript levels of cyp19a1a and amh showed a reciprocal picture, i.e., the higher was the level of amh, the lower was that of cyp19a1a. Expression of cyp11b was also up‐regulated but later than amh, and its localization was not related to the position of degenerating oocytes. These data indicate that amh is a candidate gene down‐regulating cyp19a1a, leading to “juvenile ovary‐to‐testis” transformation. Whereas, cyp11b or its product, 11‐ketotestosterone, is unlikely to be the inducer of zebrafish gonad transformation, as proposed earlier for some protogynous hermaphroditic fish species. Developmental Dynamics 236:1329–1338, 2007. © 2007 Wiley‐Liss, Inc.
Cloning and spatial and temporal expression of the zebrafish dopamine D1 receptor
Authors: Li Ping , Shah Sitar , Huang Luoxiu , Carr Aprell L. , Gao Yan , Thisse Christine , Thisse Bernard , Li Lei
Published: March 2007

Dopamine plays important roles in the regulation of central nervous system (CNS) development and functions. In vertebrates, two families of dopamine receptors, collectively known as dopamine D1 and D2 receptors, have been identified. Recently, dopamine receptors have been targeted by pharmacological and therapeutic studies of neurological disorders, such as Parkinson's disease. Here, we report a study on the molecular characterization of dopamine D1 receptor in zebrafish (Danio rerio). We cloned the full‐length cDNA of a zebrafish dopamine D1 receptor, designated as drd1. The sequence of drd1 shares high homology to the sequences of dopamine D1 receptors in mammalian, amphibian, and other fish species. drd1 is expressed in the CNS. The first drd1 expression was observed at approximately 30 hours postfertilization, at which time the expression was seen in the developing diencephalon and hindbrain. In developing retinas, the expression of drd1 was detected in the inner nuclear layer with the exception of the marginal zones. In adult retinas, drd1 expression was detected in most cell types in the inner and outer nuclear layers as well as ganglion cell layer. Differential expression of drd1 in developing and adult retinas may play various roles in regulating visual system functions. Developmental Dynamics 236:1339–1346, 2007. © 2007 Wiley‐Liss, Inc.
whitesnake/sfpq is required for cell survival and neuronal development in the zebrafish
Authors: Lowery Laura Anne , Rubin Jamie , Sive Hazel
Published: March 2007

Organogenesis involves both the development of specific cell types and their organization into a functional three‐dimensional structure. We are using the zebrafish to assess the genetic basis for brain organogenesis. We show that the whitesnake mutant corresponds to the sfpq (splicing factor, proline/glutamine rich) gene, encoding the PSF protein (polypyrimidine tract‐binding protein‐associated splicing factor). In vitro studies have shown that PSF is important for RNA splicing and transcription and is a candidate brain‐specific splicing factor, however, the in vivo function of this gene is unclear. sfpq is expressed throughout development and in the adult zebrafish, with strong expression in the developing brain, particularly in regions enriched for neuronal progenitors. In the whitesnake mutant, a brain phenotype is visible by 28 hr after fertilization, when it becomes apparent that the midbrain and hindbrain are abnormally shaped. Neural crest, heart, and muscle development or function is also abnormal. sfpq function appears to be required in two distinct phases during development. First, loss of sfpq gene function leads to increased cell death throughout the early embryo, suggesting that cell survival requires functional PSF protein. Second, sfpq function is required for differentiation, but not for determination, of specific classes of brain neurons. These data indicate that, in vertebrates, sfpq plays a key role in neuronal development and is essential for normal brain development. Developmental Dynamics 236:1347–1357, 2007. © 2007 Wiley‐Liss, Inc.
Characteristics of a buck converter with new control scheme using a triangle waveform modulated by output voltage
Authors: Zhao Jinbin , Sato Terukazu , Nabeshima Takashi , Nakano Tadao
Published: March 2007

In this paper, the authors propose a new control scheme in which the output voltage is fed back into a triangle waveform of a control circuit to improve the transient response of a switching converter. The circuit structure of the proposed system is very simple and will therefore reduce the size and weight of the apparatus and have reduced production costs. Also, because an error amplifier is not used, the circuit is not affected by switching noise or the like and the circuit is easy to design. In this paper, the proposed system is applied to a synchronous rectifying buck converter; the basic properties are analyzed and the system is verified experimentally. As a result, it was confirmed that the proposed scheme has superior regulation properties and transient response characteristics. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 52–59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20256
A delta representation scheme for updating between versions of mobile phone software
Authors: Kiyohara Ryozo , Kurihara Mariko , Mii Satoshi , Kino Shigenori
Published: March 2007

In recent years the amount of software running on mobile phones has increased dramatically due to the start of data network connection services for mobile phones. As a result it has sometimes become necessary to repair defects in such products after they have been shipped to market. In this context, services have been launched that enable software to be updated after a terminal has been sold. The time taken for software to be updated is made up of the time taken to transmit the data to the handset via a mobile network or from a PC (which in turn depends on the amount of data being transmitted) and the time taken to overwrite the data on flash memory. A standard method for making the amount of data that needs to be transmitted to the handset small, is to only send delta data corresponding to those parts of the new version of the software that differ from the old version; it is generally necessary to make this delta as small as possible. Following a description of existing techniques for extracting deltas, in this paper we make multiple proposals regarding delta extraction schemes that are designed with the structure of mobile phone software particularly in mind with a view to making the delta data transmitted to the handset when updating software as small as possible; we then describe results of evaluations with actual mobile phones immediately prior to shipping. Both of the schemes that we propose are shown to allow a reduction of approximately 30 percent in the size of the delta when compared with standard delta representation mechanisms. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 26–37, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20348
Stability design for on‐board distributed power system
Authors: Abe Seiya , Hirokawa Masahiko , Zaitsu Toshiyuki , Ninomiya Tamotsu
Published: March 2007

Recently, on‐board distributed power systems consisting of bus converter and POL have usually been used for IT infrastructure equipment. However, even if each converter has stable operation, the bus voltage may oscillate and the system may be unstable, depending on the bus converter design; this has been a serious problem in recent years. Solution of the issue is highly desirable, and in order to improve the system stability various techniques have been discussed. This paper investigates the improvement of the system stability by the control method. The availability of full‐regulated bus converter is especially examined. It is determined that the full‐regulated method is the optimal control method for the bus converter because a full‐regulated bus converter can reduce bus voltage oscillation and adjust to input voltage variations flexibly by regulation. A stability design process is proposed for an on‐board distributed power system using a full‐regulated bus converter. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 18–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20356
A study of the application of mobile IP to IP‐VPN and the development of mobile foreign agent
Authors: Hata Hiraki
Published: March 2007

Mobile IP is a protocol which provides a function by which a mobile node (MN) continuously retains a single IP address and continues to use the same IP address, even if the MN moves from the network to which it originally connected (Home Network) to another network. This paper is a study of the advantages of IPsec for MIP applied to IP‐VPN, with a small number of terminals per node and where the subject devices are integrated devices such as non‐personal computer terminals. In order to apply MIP to such an IP‐VPN, a new MFA mode is proposed, in addition to the FA mode and CoA mode which have previously been provided to Mobile IP. In the MFA mode, both the MN and MFA move together. Furthermore, it is proposed to include an autoconfiguration function as well. This can be expected to result in reduced terminal shipping costs. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(7): 9–17, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20385
Injection signal controlled active phased arrays without mode jumps
Authors: Sanagi Minoru , Fujimori Kazuhiro , Nogi Shigeji
Published: March 2007

An examination is made of phased array operation, by injecting signals with different phases into both ends of a coupled microwave oscillator system and controlling that phase, as a system for an active phased array antenna using frequency locking. This system has multiple operating modes, but by causing a slight deviation of only the free‐running frequency of the end oscillator from the frequency of the injection signal, mode jumps can be suppressed and the phase difference between the oscillators made large. The effectiveness of this method can be numerically confirmed by finding the conditions for single mode operation with an approximation analysis of the governing equation. Using an active integrated antenna constructed of a patch antenna and serial‐feedback FET oscillators, an experiment was performed by scanning the radiation beams of two‐, three‐, and five‐element antenna arrays to demonstrate that the scan range in the radiation direction was extended with single mode operation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 34–45, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20293
A novel waveguide bandpass filter with multiple attenuation poles using four‐armed square‐loop FSSs
Authors: Ohira Masataka , Deguchi Hiroyuki , Tsuji Mikio , Shigesawa Hiroshi
Published: March 2007

This paper presents a waveguide filter loaded with frequency selective surfaces (FSS) that can realize multiple attenuation poles. As the FSS resonant element, a square‐loop FSS with arms is proposed. The authors have studied the design of the shape of the resonant element for the FSS by using the genetic algorithm (GA). There have been problems, namely, that the shape obtained by GA is complex and that the optimization design by GA requires a considerable amount of time. In this paper, these problems are eliminated by means of a square‐loop FSS with arms. The proposed resonant element has a resonance (full transmission) at the center frequency while it has antiresonances (full reflection) on both sides. By means of these antiresonances, attenuation poles can be created. The resonant frequencies can easily be controlled by adjusting the element shape. As an example, a three‐stage waveguide filter loaded with FSSs with a total of six attenuation poles in the X band is designed. By comparison of the numerical results and the experimental results, effectiveness of the proposed shape is verified. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 26–33, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20305
An expression of high‐frequency characteristics on a high‐density multilayer wiring board using an LC ladder network as a unit segment
Authors: Ishikawa Ryo , Imai Norio , Honjo Kazuhiko
Published: March 2007

This paper presents a method of expressing a high‐speed signal transmission line connecting the LSIs in a high‐density multilayer wiring board in terms of cascaded connections of LC ladder networks. For signal transmission with a fundamental frequency beyond 1 GHz, the signal transmission lines in a multilayer board are treated as distributed transmission lines. However, there exist many scattering elements such as vias for interlayer connection in the multilayer board that disturb the transmission characteristic. Transmission characteristics affected by these elements are analyzed by electromagnetic field simulation in general. However, the simulation requires a lot of simulation time and computer resources. In order to simplify the simulation, the signal line structures in the board are constructed with combinations of several segments. Moreover, each unit segment is expressed in terms of an LC ladder network so that an analysis based on the lumped elements can be carried out within a short time. This paper describes a technique for deriving the L and C values of the ladder equivalent circuits for various unit segments such as passive components and transmission lines. By comparison with the electromagnetic field analysis and measurement, the usefulness of the method is demonstrated. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 18–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20317
Highly reliable InP‐based HBTs with a ledge structure operating at high current density
Authors: Fukai Yoshino K. , Kurishima Kenji , Ida Minoru , Yamahata Shoji , Enoki Takatomo
Published: March 2007

For the InP HBT being developed for 40 Gbit/s optical communication system realization, the effectiveness of the ledge structure for enhancement of device lifetime due to suppressing generation of the surface recombination current is confirmed. An accelerated life test for this structure shows that the activation energy of the mode in which the current gain decreases gradually is 1.7 eV, that the device life extrapolated at 125°C is more than 1×108hours, and that this degradation does not depend on the operating current density up to 2 mA/µm2. Thus, high reliability at a high current density allowing high‐speed design is realized. Also, the degradation mechanism of the current gain is analyzed. It is found that sudden degradation can be controlled by increasing the layer thickness of the emitter and can consequently be eliminated. The above results confirm that the authors' InP HBT has sufficient reliability for practical implementation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 1– 8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20320
A fingernail‐mounted tactile display for augmented reality systems
Authors: Ando Hideyuki , Watanabe Junji , Inami Masahiko , Sugimito Maki , Maeda Taro
Published: March 2007

There have been many efforts to present skin tactile information to the fingertips. In these studies, however, the tactile stimulus has been presented to the pad side of the finger. In that approach, it is difficult to superimpose virtual tactile information on the tactile information of the real world. Consequently, this paper proposes a tactile display device in which vibration is applied to the fingernail side, not to the pad side of the finger, so that a virtual undulating sensation can be superimposed on the real‐world sensations obtained during the scanning action of the finger. The proposed device is based on the phenomenon that when a vibration is applied while the finger is scanning an object, a perception of undulation rather than of vibration is produced. This study measures the pressure change produced on the pad side of the finger in such a scanning operation and investigates the mechanism that causes the perception. The vibration timing required to present an arbitrary virtual convex width is determined by a psychophysical experiment. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(4): 56–65, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20355
Signed power‐of‐two expression for multipliers of lifting wavelet for image compression
Authors: Tonomura Yoshihide , Iwahashi Masahiro , Tsubone Tadashi , Kambayashi Noriyoshi
Published: March 2007

For image compression, frequency conversions such as the discrete cosine transform (DCT) and the wavelet transform (DWT) have been widely used. The multiplier coefficients used in these conversions are in general defined as real numbers, but they are approximated by a finite word length in the hardware configuration. This causes degradation of the reconstructed images due to mismatch of the coefficient values for the forward and backward transforms. In order to reduce the degradation of the reconstructed images caused by coefficient mismatch, a sufficiently long word length can be provided in setting the finite word length. However, since the compressed image data undergo quantization processing prior to entropy encoding in general, a word length greater than a certain length causes redundancy. Hence, this paper proposes a method in which the coefficient values of each multiplier are provided by the signed power‐of‐two (SPT) representation, using a sum of powers of 2 with as small a (finite) number of terms as possible, so that the error caused by coefficient mismatch is smaller than the error caused by quantization. In this way, a minimum‐size wavelet circuit can be constructed in which the effect of coefficient mismatch between the forward and backward transformations cannot be visually recognized. It was experimentally confirmed by an experiment using the HDL language that the size of the circuit configuration used in the proposed method could be reduced by about 50% in comparison with the circuit in which the sum of the same number of powers of 2 is assigned to each multiplier coefficient. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 47– 57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20272
A data hiding method for JPEG 2000 coded images using modulo arithmetic
Authors: Jin Hong Lin , Fujiyoshi Masaaki , Seki Yusuke , Kiya Hitoshi
Published: March 2007

This paper proposes a novel data hiding method for JPEG 2000 coded images that embed multi‐level information into quantized discrete wavelet transformed coefficients. Since the proposed method hides information represented as an integer to a transformed coefficient rounded to an integer, a JPEG 2000 code‐stream conveying data keeps its standard JPEG 2000 code‐stream structure. The proposed method is able to extract hidden data without memorizing embedding positions; it thus chooses transformed coefficients to which data is hidden freely. This characteristic makes the proposed method suitable for hiding data to a JPEG 2000 coded image with consideration of Region of Interest (ROI) coding that is a major feature. Simulation results show the effectiveness of the proposed method. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 37– 46, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20286
FFT‐based fast conjugate gradient method for real‐time dereverberation system
Authors: Furuya Ken'ichi , Kataoka Akitoshi
Published: March 2007

When speech at a location away from a microphone is received, the received speech is degraded by reverberation in a room. To deal with this problem, a semiblind dereverberation method has been proposed in which no prior measurement of the room impulse response is used. However, the fast computation was required because an enormous amount of computation is needed for inverse filter calculation. In this paper, an acceleration method for the inverse filter calculation in the semiblind dereverberation method is proposed. For speed enhancement, the similarity of the correlation matrix to the convolution matrix is considered. By using fast convolution by the FFT in the conjugate gradient method, a dramatic increase in computation speed is achieved. A real‐time dereverberation system was constructed on a personal computer by installing the proposed method and was tested in an actual environment. It was confirmed that the proposed method can achieve high‐speed operation without degradation of dereverberation performance. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 25–36, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20292
Noise removal for degraded images by IBS shrink method in multiwavelet domain
Authors: Lu Jianming , Wang Ling , Li Yeqiu , Yahagi Takashi
Published: March 2007

The wavelet transform has been used for image compression, image restoration, signal processing, and pattern recognition. In most cases, processing is performed with a scalar wavelet using one scaling function. However, the scalar wavelet has the deficiency that the properties of shortness of support, regularity, orthogonality, and high vanishing moment are not shared at the same time. Recently, the multiwavelet, consisting of several scaling functions and several wavelet functions, has been proposed. Since several input data are obtained by preprocessing in the multiwavelet transform, many studies of applications of the multiwavelet in the fields of signal processing and image processing are being carried out. Many engineering achievements have been reported. However, little has been reported on the use of multiwavelets for restoration of degraded images. This is a research field with prospects for future growth. In the present research, a threshold shrinking method is proposed in which different threshold values are used for the horizontal, vertical, and diagonal directions at each level and also within the same level in the multiwavelet domain for degraded images with superimposed Gaussian noise. The effectiveness of the proposed method is demonstrated by a computer simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 15– 24, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20295
Performance analysis of UWB impulse radar receiver using parallel IPCP
Authors: Hatano Hiroyuki , Yamazato Takaya , Okada Hiraku , Katayama Masaaki
Published: March 2007

This paper considers a vehicle‐borne target detection system for short range in which an UWB (Ultra Wideband) impulse radar is used. The UWB impulse radar uses a pulse with widths of less than nanosecond order. Therefore, many multipath returns are observed on the receiving side. An IPCP (Inter‐Period Correction Processing) receiver that resolves complexity of the receiver caused by multiple paths has been proposed. However, the integration time of the correlator in the IPCP receiver is limited by the period of the transmission signal (code length) and affects the range measurement accuracy. This paper considers vehicle mounting for applications. In order to assure safety, a receiver is constructed with several IPCP receivers in parallel, so that the range measurement accuracy is improved. In addition, a receiver which reduces the complexity of threshold setting in the conventional IPCP receiver when several targets are detected is proposed. The outputs of these receivers are derived analytically and improvement of the range measurement accuracy is confirmed. Further, based on the analytical results, the output of each receiver is characterized and the relationship of the threshold, detection probability, and false error probability is derived. Finally, the characteristics of use of the receiver as a vehicle‐mounted radar are evaluated by simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(7): 1–14, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20303
A new method for transient stability analysis
Authors: Yorino Naoto , Saito Takeshi , Kamei Yoshifumi , Sasaki Hiroshi
Published: March 2007

This paper proposes a brand‐new method for transient stability analysis in power systems. The proposed method directly computes the critical trajectory for a given contingency to obtain the critical condition of the studied system. Although the method may be useful for general nonlinear dynamic systems, it is applied to the problem of obtaining a controlling UEP, unstable equilibrium point, which provides inevitable information for the energy function methods to assess transient stability. Namely, the proposed method effectively yields a critical trajectory on PEBS together with the controlling UEP, thus improving the conventional BCU method. The effectiveness of the proposed method is demonstrated in 3‐machine 9‐bus and 6‐machine 30‐bus systems. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 26–33, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20245
Magnetic suspension force in an induction bearingless motor with a squirrel cage rotor
Authors: Katou Tatsuya , Chiba Akira , Fukao Tadashi
Published: March 2007

Theoretical equations of magnetic force in an induction bearingless motor have been reported. In the bearing‐less motor, both 4‐pole and 2‐pole windings are stored in stator slots for torque and suspension force generation. In the analysis, squirrel cage rotor currents are considered. These currents are induced by both torque and suspension winding currents. Inductance matrix is represented by four sets of three‐phase windings, thus a 12×12 matrix is constructed. A simplification and reasonable assumptions are introduced to obtain understandable expressions for suspension force and torque representation. The rotor flux linkages in an induction bearingless motor are derived, and a simulation model of suspension force is then constructed. It is shown that the response and the phase of suspension force are delayed in the case of cage rotors. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 77–87, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20340
Stability analysis methods for delta operator polytopic polynomials
Authors: Matsuda Tadasuke , Kawabata Keishi , Mori Takehiro
Published: March 2007

Stability analysis of a linear uncertain polynomial system in parameter space is one of the central themes of recent control theory. It often requires an enormous number of stability checks with conventional stability test methods. A delta operator polytopic polynomial, a convex combination of some delta operator vertex polynomials, is one of such cases. In this paper, robust stability is addressed for polytopic delta operator polynomials and several necessary and sufficient stability conditions are derived. The delta operator, an operator used to express discrete time systems, is known to have significant features: numerical advantage in implementation and ability to smoothly connect the z‐operator with the Laplace operator. Based on this last feature and on the celebrated Edge theorem, we first derive three kinds of exact stability conditions for the uncertain delta operator polynomials. We then extend the directional stability radius method, which was developed for diamond polynomials, so that it can also be applied to polytopic polynomials. This extension gives rise to the fourth stability test. Furthermore, it is shown from the result of the numerical experiments with these stability analysis methods that one of these four methods, which uses eigenvalues of matrices, turns out to be most efficient for stability analysis of the polytope. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 56– 64, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20433
R‐learning with multiple state‐action value tables
Authors: Ishikawa Koichiro , Sakurai Akito , Fujinami Tsutomu , Kunifuji Susumu
Published: March 2007

We propose a method to improve the performance of R‐learning, a reinforcement learning algorithm, by using multiple state‐action value tables. Unlike Q‐ or Sarsa learning, R‐learning learns a policy to maximize undiscounted rewards. Multiple state‐action value tables cause substantial explorations as needed and make R‐learning work well. Efficiency of the proposed method is verified through experiments in a simulated environment. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 34– 47, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20473
Proposal of permanent magnet repulsive maglev transportation system: possibility of automobile with magnetic levitation
Authors: Moriyama Shin‐Ichi
Published: March 2007

This paper describes a maglev transportation system for automobiles. The track is an array of permanent magnet blocks, and the levitating body is the bedplate which consists of permanent magnet plates, propulsion coils, levitation coils, and guidance coils. The feature of this system is that an automobile equipped with the bedplate is free to approach into the track or to swerve from the track by using four wheels with the lift. The force acting on the levitating body is calculated on the assumption that each permanent magnet can be expressed as a surface current. From the calculation results, it is proven that an automobile of 4.35 m length, 1.8 m width, and 1700 kg weight can run at a speed of 500 km/h against the air resistance force of 3704 N on the condition that the battery has an output of 337.5 V and a capacity of 190 Ah. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 65– 76, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20491
Relationship between grain boundaries and electrical degradation of ZnO varistors
Authors: Takada Masayuki , Yoshino Hiroyuki , Yoshikado Shinzo
Published: March 2007

The effects of the electrical degradation characteristics and microstructure of Sb2O3‐added ZnO varistors were investigated by field emission scanning electron microscopy (FE‐SEM), energy dispersion X‐ray spectroscopy (EDX), optical microscopy, X‐ray diffraction (XRD), and voltage– current (V−I) characteristic measurement. The nonlinearity index α of the V−I characteristic for Bi‐Mn‐Co‐Sb2O3‐added ZnO varistors decreased with increasing amount of Sb2O3 after electrical degradation. Twin crystals of ZnO were formed by the addition of Sb2O3. The number of twin crystals with two c‐axes perpendicular to the twin plane increased and the number of twin crystals with two c‐axes parallel to the twin plane decreased with increasing addition of Sb2O3. It is suggested that electrical degradation is affected by a combination of orientations of ZnO grains containing twin planes and that a double Schottky barrier may not be formed in the twin plane. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 1– 9, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20493
Evaluation of audible noise from surface processing conductors for AC overhead transmission line
Authors: Miyajima Kiyotomi , Tanabe Kazuo
Published: March 2007

Corona discharge may cause audible noise, and it is frequently generated from wet conductors of high‐voltage AC overhead transmission lines. Audible noise arises more easily from new conductors that have lubricating oil on their surface than from aged conductors. In this paper, the corona characteristics, particularly the audible noise, of conductors having various wetting properties are presented for the purpose of developing a corona‐free conductor for AC overhead transmission lines. It was found that a conductor having a super‐hydrophobic surface exhibited a minimized audible noise level, but it does not have sufficient durability for practical applications. Furthermore, a conductor having a super‐hydrophilic surface made by thermal spraying of TiO2 showed good performance regarding the suppression of audible noise. The thermal spraying of TiO2 seems to be an effective processing technique that has sufficient durability for practical applications. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 19–25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20509
A novel Fcγ receptor ligand augments humoral responses by targeting antigen to Fcγ receptors
Authors: Jensen Mark A. , Arnason Barry G. W. , White David M.
Published: March 2007

Generating efficient antibody (Ab) responses against weak antigens remains challenging. Ab responses require antigen (Ag) uptake by antigen‐presenting cells (APC), followed by presentation of processed Ag to T cells. Limited uptake of antigenic peptides by APC constrains Ab responses. Here we improve vaccine efficacy by targeting Ag to Fcγ receptors (FcγR) using R4, a recombinant FcγR ligand. R4 has four repeats per chain of the hinge region and CH2 domain (HCH2) of human IgG1. HCH2 encompasses the FcγR binding site. The repeats are linked to the human IgG1 framework. To test R4 in augmenting Ag uptake, we expressed human serum albumin domain 1 (HSA1) at the N terminus of R4 to produce HSA1R4. HSA1R4 (50 μg) administered to mice in Ribi adjuvant induces up to 1100‐fold higher HSA1‐specific IgG titers than HSA1 (p<0.001). HSA1R4 (250 ng) induces up to 130 times more anti‐HSA1 Ab than HSA1Fc, a protein with HSA1 linked to the IgG1 framework (p<0.001). HSA‐reactive T cells proliferate more briskly to HSA1R4 than to HSA1Fc (p<0.008). Immunization with HSA1R4 yields greater T cell reactivity to HSA1 ex vivo than immunization with HSA1Fc (p<0.004). Linking antigenic peptides to linear HCH2 polymers may facilitate vaccine development.
CD8 exerts differential effects on the deployment of cytotoxic T lymphocyte effector functions
Authors: Laugel Bruno , Price David A. , Milicic Anita , Sewell Andrew K.
Published: March 2007

Cytotoxic T lymphocytes (CTL) are equipped with a range of effector functions that contribute both to the control of intracellular pathogens and dysregulated cellular proliferation and to the development of certain immunopathologies such as autoimmune disease. Qualitative analyses of various CTL responses have revealed substantial heterogeneity in the diversity of functions that are mobilized in response to antigen. Here, we studied the influence of the CD8 co‐receptor, which is known to enhance antigen recognition by CTL, on the secretion of eight different cytokines and chemokines by human CTL clones using flow cytometric bead array. Our results show that abrogation of MHC class I/CD8 interactions exerts a differential influence on the distinct individual effector functions that are elicited in response to agonist ligands. The magnitude of this co‐receptor blockade inhibitory effect was clearly related to the hierarchy of cytokine secretion in terms of activation threshold because those functions requiring the highest amounts of antigen were most affected. Thus, modulation of CD8 activity can effectively tune not only the sensitivity but also the qualitative profile of CTL responses.
Fcα receptor I activation induces leukocyte recruitment and promotes aggravation of glomerulonephritis through the FcRγ adaptor
Authors: Kanamaru Yutaka , Arcos‐Fajardo Michelle , Moura Ivan C. , Tsuge Toshinao , Cohen Hélène , Essig Marie , Vrtovsnik François , Loirat Chantal , Peuchmaur Michel , Beaudoin Lucie , Launay Pierre , Lehuen Agnès , Blank Ulrich , Monteiro Renato C.
Published: March 2007

Myeloid cells bear Fc receptors (FcR) that mediate inflammatory signaling through the ITAM‐containing FcRγ adaptor. They express FcRγ‐associated FcαRI, which modulate either activating or inhibitory signaling depending on the type of ligand interaction. The role of FcαRIγ in disease progression remains unknown, notably in IgA nephropathy (IgAN), one of major causes of end‐stage renal disease, in which large amounts of circulating IgA‐immune complexes (IC) may mediate receptor activation. To analyze the involvement of FcαRI activation in glomerulonephritis (GN), we generated Tg mice expressing a mutated, signaling‐incompetent, human FcαRIR209L that cannot associate with FcRγ. Like FcαRIwt‐Tg mice, they developed mesangial IgA deposits but not macrophage infiltration. FcαRI activation in FcαRIwt, but not in FcαRIR209L, Tg mice resulted in marked inflammation with severe proteinuria and leukocyte infiltration in spontaneous IgAN or anti‐glomerular basement membrane Ab‐induced GN models. Receptor triggering of syngenically transferred FcαRIwt Tg macrophages into non‐Tg animals induced their recruitment into injured kidneys during GN development. FcαRIwt cross‐linking on macrophages activated MAP kinases and production of TNF‐α and MCP‐1. Moreover, IgA‐IC from IgAN patients activated FcαRI and induced TNF‐α production. Thus, FcαRI activation mediates GN progression by initiating a cytokine/chemokine cascade that promotes leukocyte recruitment and kidney damage.
New insights into the subversion of the chemokine system by poxviruses
Authors: Alcami Antonio
Published: March 2007

Viruses encode immune evasion mechanisms to survive in the immunocompetent host. Chemokines mediate the migration of immune cells and their critical role in immunity is emphasized by the numerous virus‐encoded strategies to modulate their activity. Evidence published in this issue of the European Journal of Immunology uncovers novel mechanisms encoded by vaccinia virus to inhibit the chemokine‐mediated migration of DC, an important event in the initiation of the immune response to viral infections.

See accompanying article: http://dx.doi.org/10.1002/eji.200636230
Insight Into the Intermolecular Factors Responsible for theZ,ZConfiguration of Ar–X–N=S=N–X–Ar (X = S, Se) Derivatives in the Solid State
Authors: Tersago Karla , Bagryanskaya Irina Yu. , Gatilov Yuri V. , Gromilov Sergey A. , Makarov Alexander Yu. , Mandado Marcos , Van Alsenoy Christian , Zibarev Andrey V. , Blockhuys Frank
Published: March 2007

The molecular and crystal structures of three new derivatives of Ph–S–N=S=N–S–Ph (1), with 2,4,6‐(tert‐C4H9)3C6H2(4), C6F5(5) and 4‐CF3C6F4(6) as peripheral rings, respectively, and one new derivative of Ph–Se–N=S=N–Se–Ph (2), with C6F5(7) as peripheral rings, are reported and discussed in connection with those of the two parent structures1and2and those of the previously studied derivative of1containing 4‐ClC6H4(3) as peripheral rings. For these seven compounds theZ,Zconfiguration is the only one of the three theoretically possible configurations observed in the solid state and this configurational preference can not be explained by intramolecular stereoelectronic effects. Calculation of the packing energies and densities for the six most common space groups revealed that the crystal packing of the parent structure1in theZ,Zconfiguration has a systematic preference over the corresponding packing of1in theZ,Econfiguration by 0.3–4.9 kJ mol–1. As a result, packing forces are most likely responsible for the dominance of theZ,Zconfiguration of the title compounds in the crystal.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
An Unusual Carbonyl Chemical Shift in a Carbonylhexairidium Cluster: A Combined Solid‐State NMR and DFT Approach
Authors: Chierotti Michele R. , Garlaschelli Luigi , Gobetto Roberto , Nervi Carlo , Peli Giulia , Sironi Annalisa , Della Pergola Roberto
Published: March 2007

The 13C NMR spectrum of TMBA2[Ir6(CO)15] [TMBA =(CH3)3N(CH2C6H5)] shows, at low temperatures, an unprecedented μ2‐bridging carbonyl low‐frequency shift, with the resonances of the terminal μ1‐carbonyl ligands placed at higher frequencies. The chemical shift tensors and the shielding anisotropies of the carbonyl ligands, obtained from solid‐state NMR analysis, allow us to determine the nature of the M–CO interaction. The results have been compared with the 13C MAS data of Ir6(CO)16 where μ3‐CO ligands are present. Further evidence for the assignment and for the peculiar chemical shift value of bridging carbonyl ligands in TMBA2[Ir6(CO)15] has been obtained by the DFT calculation of the NMR parameters. The scalar and spin‐orbit (SO) relativistic two‐component zero‐order regular approximation (ZORA) methods were employed in the geometry optimization and NMR chemical shift calculations, respectively. The large SO contribution (δ = 26.6 ppm) to the μ2‐bridging CO ligand 13C chemical shifts accounts for the position of the experimentally observed resonance.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Relationship Between 27Al Quadrupolar Parameters and AlF63– Octahedron Connectivity in Crystalline and Glassy Fluoroaluminates
Authors: Body Monique , Legein Christophe , Buzaré Jean‐Yves , Silly Gilles
Published: March 2007

27Al SATRAS and MQ‐MAS spectra were recorded for eight crystalline compounds, from the CaF2–AlF3 and BaF2–AlF3 binary and BaF2–CaF2–AlF3 ternary systems, and four glass compositions with different CaF2/BaF2/AlF3 contents. For the crystalline phases, the reconstruction of the spectra leads to the precise determination of the NMR parameters. For the glassy phases, the 27Al SATRAS spectra have been reconstructed using quadrupolar parameter distributions. The main finding of this study is the dependence of the quadrupolar frequency on the type of AlF63– octahedron connectivity. For crystalline phases the experimental νQ values range between 75 kHz and 510 kHz for structures built up from isolated octahedra, and are between 560 kHz and 1250 kHz for structures built up from isolated chains of cis‐connected octahedra, and are between 1530 kHz and 1580 kHz for structures built up from isolated chains of trans‐connected octahedra. In the glassy phases the maximum of the quadrupolar frequency distribution shifts toward larger values and its width increases with increasing AlF3 content, and subsequently with the number of connected octahedra. The range of the νQ values seems to indicate that when the octahedra are connected, cis connections occur most frequently. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Bis(phenylethylamide) Derivatives of Gd‐DTPA as Potential Receptor‐Specific MRI Contrast Agents
Authors: Laurent Sophie , Parac‐Vogt Tatjana N. , Kimpe Kristof , Thirifays Coralie , Binnemans Koen , Muller Robert N. , Vander Elst Luce
Published: March 2007

DTPA‐bis(amide) derivatives bearing phenyl, phenol or catechol groups that mimic side chains of naturally occurring amino acids, such as phenylalanine, tyrosine or dopamine, were synthesized and characterized by elemental analysis, electrospray mass spectrometry, NMR spectroscopy and IR spectroscopy. The gadolinium(III) complexes of the ligands DTPA‐bis(tyramide) [DTPA‐(TA)2], DTPA‐bis(3‐hydroxytyramide) [DTPA‐(HTA)2] and DTPA‐bis(phenylalanine ethyl ester) [DTPA‐(PAE)2], were prepared and then studied in vitro by 17O NMR spectroscopy and by nuclear magnetic relaxation dispersion (NMRD) measurements. The residence time of the coordinated water in gadolinium(III) complexes was obtained from 17O NMR relaxometric T2 measurements. At 310 K, the following τM values were obtained: Gd‐DTPA‐(TA)2 582 ns, Gd‐DTPA‐(HTA)2 372 ns and Gd‐DTPA‐(PAE)2 809 ns. As shown by the analysis of the proton NMRD profiles, the larger proton relaxivities of the gadolinium(III) complexes at 310 K relative to that of the parent Gd‐DTPA complex are mainly because of the increase in the rotationalcorrelation time. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Succinimidyl Carbamate Derivatives from N‐Protected α‐Amino Acids and Dipeptides―Synthesis of Ureidopeptides and Oligourea/Peptide Hybrids
Authors: Fischer Lucile , Semetey Vincent , Lozano Jose‐Manuel , Schaffner Arnaud‐Pierre , Briand Jean‐Paul , Didierjean Claude , Guichard Gilles
Published: March 2007

The preparation of succinimidyl (1‐{[(alkyloxy)carbonyl]amino}‐1‐X‐methyl)carbamates (4) and succinimidyl [1‐(acylamino)‐1‐X‐methyl] carbamates (5) from a variety ofN‐Boc‐, ‐Z‐ or ‐Fmoc‐protected α‐amino acids and dipeptides as well as the carbamate structural characterization are described. We have previously shown that succinimidyl carbamates 5, derived from N‐Boc dipeptides, can serve as direct precursors of 1,3,5‐triazepan‐2,6‐diones, a novel class of conformationally constrained dipeptide mimetics. Herein, we have evaluated the use of these building blocks for the synthesis of ureido‐peptides (in solution and on solid support), peptidyl hydantoins, oligoureas and some oligo(urea/amide) hybrids. Conformational investigations by NMR of ureidotripeptide 6i and pentamer 10, consisting of alternating amides and ureas, suggested that folded conformations (i.e. a urea turn) characterized by a cis,trans (E,Z) geometry of the urea linkage are populated in both [D5]pyridine and [D6]DMSO solutions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Vinylic Halogenation in 4‐Alkylidenazetidin‐2‐ones
Authors: Cainelli Gianfranco , Galletti Paola , Giacomini Daria , Licciulli Sebastiano , Quintavalla Arianna
Published: March 2007

The synthesis of a new family of halogenated β‐lactams by oxidative substitution of vinylic hydrogen in conjugated double bonds of 4‐alkylidenazetidinones is reported. Optimised procedures give good to excellent yields of chloro, bromo, iodo and nitro derivatives. A mechanism to explain the direct vinylic substitution is proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)