bluuebunny/crossref_metadata_2025_split huggingface dataset:
A 3D RF radiation‐immunity test method using rotating AM‐EM fields
Authors: Murano Kimitoshi , Kami Yoshio 
Published: April 2004

AbstractThis paper discusses a radiation‐immunity test method using an amplitude‐modulated low‐speed rotating‐polarization electromagnetic field (rotating electromagnetic field). By using the amplitude‐modulated electromagnetic field as the applied electromagnetic field in the radiation‐immunity test, it is possible to simulate the phenomenon of unintentional detection in an electronic device under applied interference, with noise appearing in the final stage of the device (such as the voice output). This paper describes a method for generation of an amplitude‐modulated rotating electromagnetic field and its fundamental characteristics with a view to application as the applied electromagnetic field in the radiation‐immunity test. Further, a radiation‐immunity test of a low‐frequency amplifier using the present electromagnetic field is performed as an example. The effectiveness of the radiation‐immunity test method using the amplitude‐modulated rotating electromagnetic field is demonstrated. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(9): 45–53, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10196
Jitter characteristics of timing recovery scheme using a prefilter
Authors: Wakabayashi Isamu , Miyauchi Kazuhiro 
Published: April 2004

AbstractAnalysis of timing jitter is presented for a baseband polar system, BPSK and QPSK with AWGN. A cosine roll‐off bandlimiting scheme is assumed. The timing recovery circuit is composed of a prefilter, a square‐law device, and a timing tank. Normalized jitter spectral densities and rms jitter are defined and calculated in order to examine jitter characteristics in various systems in common. The normalized jitter spectral density for the S × S component becomes negligibly small for every roll‐off factor. Therefore, the rms jitter is determined only with the S × N and N × N components. The S × N component is predominant for large Eb/N0 and the total rms jitter is almost inversely proportional to the square root of Eb/N0. Numerical calculation in QPSK for a tank Q of 100 shows that a jitter reduction effect of a prefilter exists when Eb/N0 is greater than 10 dB and that the rms jitter decreases with increasing Eb/N0 and increasing roll‐off factor. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(9): 28–35, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10206
Traffic performance of a large‐zone mobile network overlaid with spot macrocells
Authors: Yamamoto Minoru , Tomaru Kenya , Moriyama Eimatsu 
Published: April 2004

AbstractUsually, private mobile communications networks are operated with a large‐zone configuration having a radius of several tens of kilometers. However, the available frequency band is limited, and a technique must be developed in order to satisfy the increasing demand for channels. This paper considers an improvement of the traffic characteristics in which multiple macrocells are arranged spotwise in the high‐traffic‐density areas in a large zone, and the frequency is reused among the macrocells. It is shown by theoretical investigation and by simulation that traffic characteristics can be improved by sharing channels among the large zone and macrocells. The concept of logical cell is introduced in order to realize flexible placement of macrocells, and the effectiveness of the approach is demonstrated. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(9): 18–27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10207
A novel design method on low cross polarization for dual‐polarized patch antennas
Authors: Takahashi Toru , Iwase Ichirou , Nakaguro Hiromasa , Miyashita Hiroaki , Konishi Yoshihiko 
Published: April 2004

AbstractIn this paper, a design method by a feed point perturbation is proposed to obtain a low cross polarization characteristic in dual‐polarized patch antennas. In the present design method, the cross polarization generated by the mutual coupling between the orthogonal feed points is canceled by the cross polarization newly generated by the feed point perturbation. This design method is simple and does not require any special feed circuit. Hence, the method is effective for array antenna elements with a limited mounting area. Also, the optimum design conditions under the proposed design method are analytically derived. From the numerical results by the FDTD method and the experimental results, the effectiveness of the proposed design method and its optimum design condition is confirmed. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(9): 9–17, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10217
A linear tapered slot antenna electromagnetically coupled with perturbed coplanar waveguide
Authors: Matsui Akinori 
Published: April 2004

AbstractThis paper considers a linear tapered slot antenna element with electromagnetically coupled feed and discusses the matching and the radiation characteristics. In the proposed antenna element, the coplanar line with perturbed feeder, that is, the coplanar waveguide, is considered as a coupled slot line. Each line is short‐circuited to the ground conductor with different length. By electromagnetic coupling on the single‐sided coplanar dielectric substrate, feed to the linear tapered slot antenna element is realized. The following results are obtained. (1) It is possible to control the coupling magnitude and the matching frequency between the antenna element and the feeder. (2) An equivalent circuit is proposed for the matching characteristics, and the circuit parameters are determined. (3) The characteristics obtained by experiment and with an electromagnetic simulator are compared to the characteristics derived from the equivalent circuit. (4) The radiation directivity is of the single‐direction end‐fire type. A gain of 8.1 dBi and a cross polarization of −16 dB in the front direction are realized. On the basis of these results, it is demonstrated that the proposed antenna element is useful as a planar antenna element. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(8): 13–23, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10218
Multivariate Gamma distributions and their numerical evaluations for M‐branch selection diversity study
Authors: Nomoto Shinichi , Kishi Yoji , Nanba Shinobu 
Published: April 2004

AbstractIn radio wave propagation and wireless communication fields, it is known that rainfall attenuation (or rainfall intensity) in an area with small reception power or time ratio under a fading environment can be well approximated by a Gamma distribution (Nakagami‐m distribution). To investigate the selection diversity method, a joint probability function that takes correlation into consideration for multiple random variables must be used to quantitatively evaluate its results. In this paper, the authors derive an exact representation according to an infinite series for a general multivariate (M‐dimensional) Gamma distribution function with correlation. In addition, besides investigating the numerical behavior of the exact representation, they obtain an extremely effective approximate representation for practical use. That approximation, which is a revision of the probability distribution with no correlation according to the determinant of a matrix having the square roots of the correlation coefficients as its elements, not only is easy to handle, but also provides an excellent physical interpretation. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(8): 1–12, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10224
Perspectives in Inorganic Structural Genomics: A Trafficking Route for Copper
Authors: Arnesano Fabio , Banci Lucia , Bertini Ivano , Ciofi‐Baffoni Simone 
Published: April 2004

AbstractMetal ions are essential for living organisms because they are involved in many fundamental biological processes. Increasing evidence indicates that there are no free copper ions in the cell; however, a recently discovered category of proteins (metallochaperones) is responsible for copper ion trafficking and delivery to either specific target enzymes or to membrane ATPases for metal translocation. A search in the available genomes for copper chaperones and soluble domains of the ATPases reveals a large variety of systems. In this Microreview, the example of copper transfer from outside a yeast cell into the Golgi organelle is considered, as well as related processes in other eukaryotes and in prokaryotes. The investigation of the structure and metal‐binding properties of these proteins is crucial for understanding the process of copper trafficking at the molecular level and how coordination chemistry may contribute to the interpretation of the energetics of the metal environment. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Reaction of [In(NEt2)3]2 with N(CH2CH2NSiMe3H)3: Synthesis and Characterization of New Azaindatranes and Azaindocane
Authors: Shutov Pavel L. , Karlov Sergey S. , Harms Klaus , Churakov Andrei V. , Lorberth Jörg , Zaitseva Galina S. 
Published: April 2004

Abstract[In(NEt2)3]2 and N(CH2CH2NSiMe3H)3 react to yield monomeric azaindatrane 1, N(CH2CH2NSiMe3)3In, which is unstable without additional donor (e.g. pyridine), turning into dimeric azaindatrane 2, [N(CH2CH2NSiMe3)2(CH2CH2NH)In]2. An intermediate product of this transformation is oligomeric azaindocane 3, [N(CH2CH2NSiMe3)2In(CH2CH2NSiMe3)]3. The composition and structures of new compounds have been established by 1H and 13C NMR spectroscopy. The crystal structures of 1·Py, trans‐2, and 3 have been determined by X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Modeling transport effects on ground‐level ozone using a non‐stationary space–time model
Authors: Huang Hsin‐Cheng , Hsu Nan‐Jung 
Published: April 2004

AbstractThis article presents a novel autoregressive space–time model for ground‐level ozone data, which models not only spatio–temporal dynamics of hourly ozone concentrations, but also relationships between ozone concentrations and meteorological variables. The proposed model has a non‐separable spatio–temporal covariance function that depends on wind speed and wind direction, and hence is non‐stationary in both time and space. Ozone concentration for a given location and time is assumed to be directly influenced by ozone concentrations at neighboring locations at the previous time, via a weight function of space–time dynamics caused by wind speed and wind direction.To our knowledge, the proposed method is the first one to incorporate the transport effect of ozone into the spatio–temporal covariance structure. Moreover, it uses a computationally efficient space–time Kalman filter and can compute optimal spatio–temporal prediction at any location and at anytime very fast for given meteorological conditions. Ozone data from Taipei are used for illustration, in which the model parameters are estimated by maximum likelihood. Copyright © 2004 John Wiley & Sons, Ltd.
Rare terpenoid esters from Hyparrhenia rufa (Nees) Stapf. growing wild in Nigeria
Authors: Ogunwande Isiaka A. , Olawore Nureni O. , Adeleke Kasali A. , Ekundayo Olusegun , König Wilfried A. 
Published: April 2004

AbstractThe volatile oil of Hyparrhenia rufa (Nees) Stapf. grown in Nigeria was obtained by hydrodistillation and analysed by GC, GC–MS, 1H‐ and 13C‐NMR. The main components found were τ‐cadinol (17.43%) and β‐selinene (11.64%). The most interesting characteristic of the oil was the presence of four unusual and rarely occurring terpenoid esters: (E,E)‐methyl farnesoate (1.01%), (E,E)‐methyl‐10,11‐epoxyfarnesoate (12.17%), methyl (2E,6E)‐10‐hydroxy‐3,7,11‐trimethyldodeca‐2,6,11‐trienoate (4.3%) and methyl (2E,6E)‐3,7,11‐trimethyl‐10‐oxododecadienoate (2.25%). Copyright © 2004 John Wiley & Sons, Ltd.
Yellowing and crinkling disease and its impact on the yield and composition of the essential oil of citronella (Cymbopogon winterianus Jowitt.)
Authors: Rajeswara Rao B. R. , Bhattacharya A. K. , Mallavarapu G. R. , Ramesh S. 
Published: April 2004

AbstractA ﬁeld experiment conducted for 2 consecutive years in a semi‐arid tropical region of South India investigated the inﬂuence of yellowing and crinkling disease, caused by leaf‐sucking insects, on the yield and composition of the essential oil of Cymbopogon winterianus Jowitt (citronella cv. Java 2). Infected leaves exhibited yellow specks or blotches which in later stages developed into yellow streaks running along the length of the leaves. Emerging young leaves were pale green or yellow coloured, twisted, crinkled and developed into whip‐like structures. Severely diseased plants died. The yellowing and crinkling disease decreased biomass yield in the ﬁrst and second years of harvesting by 62.8% and 82.7%, respectively. The corresponding decreases in essential oil yield per plant were 62.8% and 79.0%. The essential oil examined by GC and GC–MS from cultivated healthy plants contained citronellal (28.4%), geraniol (24.8%), citronellol (11.8%) and elemol (10.2%). The major components from diseased plants were geraniol (19.0–25.5%), elemol (15.3–20.4%), citronellal (13.4–19.1%) and citronellol (12.9–15.1%). Caryophyllene oxide (3.5–6.0%) was an important minor component. Copyright © 2004 John Wiley & Sons, Ltd.
Identiﬁcation of the components of the essential oil from wild Corsican Daucus carota L. using 13C‐NMR spectroscopy
Authors: Gonny Marcelle , Bradesi Pascale , Casanova Joseph 
Published: April 2004

AbstractThe essential oil of wild Daucus carota L. from Corsica was investigated by GC and 13C‐NMR spectroscopy. In a ﬁrst part, a commercial sample was repeatedly chromatographed and the analysis of the fractions led to the identiﬁcation of 69 components. The oil consisted chieﬂy of phenylpropanoids (45.9%) and monoterpene hydrocarbons (38.6%), with (E)‐methylisoeugenol (33.0%), α‐pinene (24.9%) and elemicin (11.4%) as major components. The second part concerned the analysis of laboratory‐distilled oils obtained from different parts of the plant at three stages of development (prior ﬂowering, full ﬂowering and end of ﬂowering). The chemical composition of the Corsican wild carrot oil varies according to its stage of development. The oil yields, as well as the phenylpropanoid contents, particularly that of (E)‐methylisoeugenol, increase signiﬁcantly when the umbels ripen. Copyright © 2004 John Wiley & Sons, Ltd.
Do futures‐based strategies enhance dynamic portfolio insurance?
Authors: Do Binh Huu , Faff Robert W. 
Published: April 2004

AbstractIn this paper we investigate the relative performance of two approaches to dynamic portfolio insurance: the synthetic put and the Constant Proportion Portfolio Insurance (CPPI). The investigation is conducted on the Australian market, over a sample period of 59 non‐overlapping quarters from December 1987 to December 2002. Its main contribution is to provide a comprehensive assessment of the two approaches under different market conditions, and the testing of ex ante information as an input into the trading program. The major finding is that the futures‐based implementation of both synthetic put and the CPPI approach is robust to both tranquil and turbulent market conditions in preserving the desired floor. The fact that this conclusion includes the case of employing implied volatility (obtained from the options market) is highly encouraging as it suggests high implementability of the strategy. Notably, the risk‐return tradeoff shows that portfolio insurance using this volatility measure yields a return that is 64 basis points over the risk free investment. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:591–608, 2004
The performance of event study approaches using daily commodity futures returns
Authors: Mckenzie Andrew M. , Thomsen Michael R. , Dixon Bruce L. 
Published: April 2004

AbstractSimulations are conducted to assess the inferential accuracy of statistical event study approaches using daily futures returns. Methods examined include constant mean return models and several regression models—OLS, GARCH(1,1), and a GARCH(1,1) model having an error term with a Student'stdistribution. The simulations address four of the most commonly analyzed agricultural futures commodities—corn, soybeans, live cattle, and hogs. In terms of the size of the test statistics, constant mean return models with short normal periods perform poorly, leading to unacceptably high rejection rates of the null hypothesis. Test statistics from constant mean return models with longer normal periods, OLS, and GARCH specifications provide rejection rates largely consistent with those of a unit normal distribution. Test statistics from all models are powerful enough to detect abnormal performance levels below those that would trigger limit locks. At small levels of abnormal performance the GARCH(1,1) model with atdistribution was consistently the most powerful model. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:533–555, 2004
Peripapillary glial cells in the chick retina: A special glial cell type expressing astrocyte, radial glia, neuron, and oligodendrocyte markers throughout development
Authors: Quesada Adela , Prada Francisco A. , Aguilera Yolanda , Espinar Auxiliadora , Carmona Amparo , Prada Carmen 
Published: April 2004

AbstractPeripapillary glial cells of the chick are a special type of glia, not only because of their position, forming a boundary between the retina on one side and the optic nerve head (ONH) and the pecten on the other, but also because although they have the same orientation and similar shape as the retinal Müller cell (a type of radial glia) and express common markers for these cells and astrocytes, they do not express glutamine synthetase (GS) or carbonic anhydrase C (CA‐C), enzymes intensely expressed by Müller cells and astrocytes. In this study, we present further molecular characterization of these cells, using immunohistochemistry techniques. We show that peripapillary glial cells express a novel neuron antigen, 3BA8, that in the adult retina is located only in one neuron type (the amacrine cell) and in the inner plexiform layer (IPL). They also express an antigen specific to myelin and oligodendrocytes, MOSP, and a glial antigen, 3CB2, expressed by radial glia and astrocytes throughout the CNS. The study of the developmental expression of these three antigens in the peripapillary glial cell territory shows different spatiotemporal labeling patterns: 3CB2 and 3BA8 are expressed much earlier (embryonic days E3 and E5, respectively) than MOSP (E12), and during a developmental window (E6–E10) 3BA8 labels the peripapillary glial cells intensely and does not label the ONH or the optic nerve (ON), which are labeled later. The expression of 3CB2 is much more intense in the peripapillary glial cells than in Müller cells from early stages of development up to E16, and the expression of MOSP starts earlier in the peripapillary glial cells than in the Müller cells and is maintained with much higher intensity in the peripapillary glial cells throughout development. These findings show that Müller and peripapillary glial cells follow independent courses of differentiation, which together with the fact that the peripapillary glial cells express molecules typical of neurons, oligodendrocytes, radial glia, and astrocytes are evidence that peripapillary glial cells are a unique type of glia in the CNS. © 2004 Wiley‐Liss, Inc.
Neuronal expression of CD22: Novel mechanism for inhibiting microglial proinflammatory cytokine production
Authors: Mott Ryan T. , Ait‐Ghezala Ghania , Town Terrence , Mori Takashi , Vendrame Martina , Zeng Jin , Ehrhart Jared , Mullan Michae , Tan Jun 
Published: April 2004

AbstractAlthough considered an immunologically privileged site, the central nervous system (CNS) can display significant inflammatory responses, which may play a pathogenic role in a number of neurological diseases. Microglia appear to be particularly important for initiating and sustaining CNS inflammation. These cells exist in a quiescent form in the normal CNS, but acquire macrophage‐like properties (including active phagocytosis, upregulation of proteins necessary for antigen presentation, and production of proinflammatory cytokines) after stimulation with inflammatory substances such as lipopolysaccharide (LPS). Recent studies have focused on elucidating the role of neurons in the regulation of microglial inflammatory responses. In the present study, we demonstrate, using neuron‐microglial cocultures, that neurons are capable of inhibiting LPS‐induced tumor necrosis factor‐α (TNF‐α) production by microglia. This inhibition appears to be dependent on secretion of substances at axon terminals, as treatment with the presynaptic calcium channel blocker ω‐conotoxin abolishes this inhibitory effect. Moreover, we show that conditioned medium from neuronal cultures similarly inhibits microglial TNF‐α production, which provides additional evidence that neurons secrete inhibitory substances. We previously demonstrated that the transmembrane protein‐tyrosine phosphatase CD45 plays an important role in negatively regulating microglial activation. The recent characterization of CD22 as an endogenous ligand of this receptor led us to investigate whether neurons express this protein. Indeed, we were able to demonstrate CD22 mRNA and protein expression in cultured neurons and mouse brain, using reverse transcriptase‐polymerase chain reaction and antibody‐based techniques. Furthermore, we show that neurons secrete CD22, which functions as an inhibitor of microglial proinflammatory cytokine production. © 2004 Wiley‐Liss, Inc.
Evidence of active microglia in substantia nigra pars compacta of parkinsonian monkeys 1 year after MPTP exposure
Authors: Barcia Carlos , Bahillo Angel Sánchez , Fernández‐Villalba Emiliano , Bautista Víctor , Poza Y Poza Máximo , Fernández‐Barreiro Andrés , Hirsch Etienne C. , Herrero María‐Trinidad 
Published: April 2004

AbstractInflammatory changes have been found in Parkinson's disease, in humans intoxicated with the parkinsonian toxin MPTP, and in animal models of the disease. However, it is still not known whether inflammatory changes are responsible for active nerve cell death or if they have a protective role against neurodegeneration. In this study, we analyzed the glial reaction in the substantia nigra pars compacta (SNpc) and the striatum of monkeys rendered parkinsosian by chronic MPTP injections. At postmortem examination 1 year after the last MPTP injection, the density of astroglial cells and activated microglial cells in the SNpc, but not in the striatum, of MPTP‐intoxicated animals was significantly higher than in the two control animals. These data suggest that neurodegeneration was still active despite the absence of the agent triggering cell death and that the glial reaction is associated with long‐term neurodegeneration. © 2004 Wiley‐Liss, Inc.