bluuebunny/crossref_metadata_2025 huggingface dataset:
Regressive threshold model for familial analysis of complex diseases with variable age of onset
Authors: Briollais L. , Demenais F.
Published: November 2002

Few models for segregation (or combined segregation‐linkage) analysis have been developed to account for variable age of onset. The unified model (UM) can only take into account age at examination. In the logistic hazard model (LHM), Abel and Bonney ([1990] Genet. Epidemiol. 7:391–407) incorporated survival analysis concepts into the regressive logistic model of Bonney ([1986] Am. J. Med. Genet. 18:731–749), but interpretation of familial dependence parameters is difficult. In this article, we extended the regressive threshold model (RTM) proposed by Demenais ([1991] Am. J. Hum. Genet. 49:773–785) to account for a variable age of onset of complex diseases. This model assumes an underlying liability to disease and is more general than the original logistic formulation, since the phenotypes of each individual's antecedents can be adjusted for their own genotypes and covariate effects. The variation of risk with age can be expressed as a general step function, and variants of the model have been proposed by imposing different types of constraints among the time‐dependent thresholds. The performances of the three models (UM, LHM, and RTM) were compared in the context of segregation analysis of family data generated with variable age of onset. All analysis models were robust with respect to false conclusion of a major gene, and the best results were obtained under RTM. The power to detect the major gene was higher under LHM than RTM, but the best fit of the estimated cumulative age‐dependent penetrance with respect to the true value was obtained under RTM. This new model may thus prove helpful in contributing to identification of genes underlying complex diseases, since it can easily include linked marker loci and linkage disequilibrium. Genet. Epidemiol. 23:375–397, 2002. © 2002 Wiley‐Liss, Inc.
Score test for mapping quantitative‐trait loci with sibships of arbitrary size when the dominance effect is not negligible
Authors: Wang Kai , Huang Jian
Published: November 2002

In the linakge analysis of quantitative traits, an additive model that assumes no dominance effect is often adopted. Intuitively, when the no‐dominance‐effect assumption does not hold, such a practice does not make efficient use of the data, and its power to detect linkage can be improved. Here we introduce a score statistic for detecting quantitative trait loci when the dominance effect is not neglible or the dominance effect is a concern. This statistic is derived from a normal likelihood function for sibships of arbitrary size. In the derivation, the inherent genetic constraints on model parameters are fully taken into consideration. This score statistic is asymptotically equivalent to the corresponding likelihood ratio statistic, but it is much easier to compute. The asymptotic distribution of this statistic is derived, which is a mixture of χ02, χ12, and χ22. Weights for distribution components are functions of the informativeness of the marker data. The type I error rate and the power of the proposed statistic in finite sample are evaluated via simulations. Genet. Epidemiol. 23:398–412, 2002. © 2002 Wiley‐Liss, Inc.
Palaeomagnetic evidence for the Gondwanian origin of the Taurides and rotation of the Isparta Angle, southern Turkey
Authors: Piper John D. A. , Gürsoy Hali̇l , Tatar Orhan , İşseven Turgay , Koçyi̇ği̇t Ali̇
Published: November 2002

The Taurides, the southernmost of the three major tectonic domains that constitute present‐day Turkey, were emplaced following consumption of the Tethyan Ocean in Late Mesozoic to mid‐Tertiary times. They are generally assigned an origin at the northern perimeter of Gondwana. To refine palaeogeographic control we have investigated the palaeomagnetism of a range of Jurassic rocks. Forty‐nine samples of Upper Jurassic limestones preserve a dual polarity remanence (D/I=303/−9°, α95=6°) interpreted as a primary magnetization acquired close to the equator and rotated during emplacement of the Taurides. Result from mid‐Jurassic dolerites confirm a low palaeolatitude for the Tauride Platform during Jurassic times at the Afro–Arabian sector of Gondwana. Approximately 4000 km of Tethyan closure subsequently occurred between Late Jurassic and Eocene times. Although related Upper Jurassic limestones and Liassic redbeds preserve a sporadic record of similar remanence, the dominant signature in these latter rocks is an overprint of probable mid‐Miocene age, probably acquired during a single polarity chron and imparted by migration of a fluid front during nappe loading. This is now rotated consistently anticlockwise by c. 30° and conforms to results of previous studies recording bulk Neogene rotation of the Isparta region following Lycian nappe emplacement. The regional distribution of this overprint implies that the Isparta Angle (IA) has been subject to only small additional closure (<10°) since Late Miocene time. A smaller amount (c. 6°) of clockwise rotation within the IA since Early Pliocene times is associated with an ongoing extensional regime and reflects an expanding curvature of the Tauride arc produced by southwestward extrusion of the Anatolian collage as a result of continuing northward motion of Afro–Arabia. Copyright © 2002 John Wiley & Sons, Ltd.
The green tea polyphenol, epigallocatechin‐3‐gallate, protects against the oxidative cellular and genotoxic damage of UVA radiation
Authors: Tobi Simon E. , Gilbert Mileka , Paul Nigel , McMillan Trevor J.
Published: November 2002

A number of biological activities have been ascribed to the major green tea polyphenol epigallocatechin‐3‐gallate (EGCG) to explain its chemopreventive properties. Its antioxidant properties emerge as a potentially important mode of action. We have examined the effect of EGCG treatment on the damaging oxidative effects of UVA radiation in a human keratinocyte line (HaCaT). Using the ROS‐sensitive probes dihydrorhodamine 123 (DHR) and 2′,7′‐dichlorodihydrofluorescein diacetate (DCFH‐DA), we detected a reduction in fluorescence in UVA‐irradiated (100 kJ/m2) cells in the case of the former but not the latter probe after a 24‐hr treatment with EGCG (e.g., 14%, [p < 0.05] after 10 μM EGCG). In the absence of UVA, however, both DHR and DCFH detected a pro‐oxidant effect of EGCG at the highest concentration used of 50 μM. Measurements of DNA damage in UVA‐exposed cells using the single cell gel electrophoresis assay (comet assay) also showed the protective effects of EGCG. A concentration of 10 μM EGCG decreased the level of DNA single strand breaks and alkali‐labile sites to 62% of the level observed in non‐EGCG, irradiated cells (p < 0.001) with a 5‐fold higher concentration producing little further effect. Correspondingly, EGCG ablated the mutagenic effects of UVA (500 kJ/m2) reducing an induced hypoxanthine‐guanine phosphoribosyl transferase (HPRT) mutant frequency of (3.39 ± 0.73) × 10−6 to spontaneous levels (1.09 ± 0.19) × 10−6. Despite having an antiproliferative effect in the absence of UVA, EGCG also served to protect against the cytotoxic effects of UVA radiation. Our data demonstrate the ability of EGCG to modify endpoints directly relevant to the carcinogenic process in skin. © 2002 Wiley‐Liss, Inc.
HER2 overexpression in muscle‐invasive urothelial carcinoma of the bladder: Prognostic implications
Authors: Krüger Stefan , Weitsch Georg , Büttner Hartwig , Matthiensen Arne , Böhmer Torsten , Marquardt Tim , Sayk Friedhelm , Feller Alfred C. , Böhle Andreas
Published: November 2002

The HER2 (c‐erbB‐2) receptor is overexpressed in a variety of human malignant tumors and, in breast carcinoma, has been identified as a target for anti‐HER2–directed therapy with the monoclonal antibody (MAb) trastuzumab. The aim of this retrospective study was to evaluate immunohistochemic HER2 expression in a large cohort of muscle‐invasive urothelial cell carcinomas of the urinary bladder and to compare the results to pathologic characteristics and survival. Paraffin‐embedded tumor specimens from 138 patients undergoing radical cystectomy for muscle‐invasive bladder carcinoma were studied immunohistochemically with the Food and Drug Administration (FDA)‐approved HercepTest (Dako, Glostrup, Denmark). HER2 overexpression was observed in 57 of 138 tumors (41%) and occurred more frequently in high‐grade carcinomas than in low‐grade carcinomas (p = 0.036). No significant relationship with HER2 overexpression was registered for tumor staging and lymph node status. Kaplan‐Meier curves showed a significantly worse disease‐related survival (p = 0.034) in patients with HER2‐overexpressing tumors compared to those without HER2 overexpression. In addition to lymph node status (p = 0.0001; relative risk [RR] = 2.93), HER2 status (p = 0.020; RR = 2.22) was identified as an independent predictor for disease‐related survival in a multivariate analysis. These results suggest that HER2 expression might provide additional prognostic information in patients with muscle‐invasive bladder carcinomas. Because many of these patients harbor HER2‐overexpressing tumors, clinical trials evaluating the efficacy of trastuzumab in bladder carcinoma are warranted. © 2002 Wiley‐Liss, Inc.
Recurrent human papillomavirus infection detected with the hybrid capture II assay selects women with normal cervical smears at risk for developing high grade cervical lesions: A longitudinal study of 3,091 women
Authors: Bory Jean‐Paul , Cucherousset Joël , Lorenzato Marianne , Gabriel René , Quereux Christian , Birembaut Philippe , Clavel Christine
Published: November 2002

To test the reliability of the Hybrid Capture II (HC‐II) assay detecting 13 high‐risk human papillomavirus (HR‐HPV) types for the screening of cervical lesions, we monitored by cytology, HR‐HPV testing, colposcopy and biopsy, 3,091 women with normal smears at the first entry. Our primary endpoint was clinical progression defined as the presence of a high‐grade lesion (HGSIL) at the biopsy. In our population of 659 HR‐HPV‐infected women, 241 (36.6%) had a positive HR‐HPV test at 2 to 4 examinations with a final histological diagnosis of HGSIL in 51 cases (21.2%) within 4 to 36 months, while women with regressive HPV infection did not develop any lesion during the same period. In the cohort of 2,432 women testing negative for HR‐HPV infection, only 2 women (0.08%) developed a HGSIL. Both were HR‐HPV positive 18 and 24 months after the first entry, at the time of diagnosis of disease. The RR of incident HGSIL when a HR‐HPV was detected at enrollment in women with normal smears was 96.7 (95% CI, 95.8–97.7). The RR increased to 237.3 (95% CI, 222.8–251.8) when the HR‐HPV test remained positive at 2 controls, and to 314.3 (95% CI, 260.7–367.9) when the HR‐HPV test was positive at 3 controls. The evaluation of the viral load of HR‐HPV by the HC‐II did not represent a sensitive approach to predict the recurrence of HR‐HPV infection and/or the apparition of HGSIL. Nevertheless, a recurrent HR‐HPV infection detected with HC‐II represents a reliable tool to select populations at risk for the development of HGSIL. © 2002 Wiley‐Liss, Inc.
Nuclear factor‐κB, induced in human carcinoma cell line A2780 by the new anthracycline men 10755, is devoid of transcriptional activity
Authors: Camarda Grazia , Binaschi Monica , Maggi Carlo A. , Goso Cristina
Published: November 2002

The new disaccharide anthracycline MEN 10755 induces activation of both NF‐κB and p53 transcription factors in A2780 cells. Nevertheless, pharmacologic inhibition of NF‐κB activation does not modify the sensitivity of A2780 cells to MEN 10755 treatment. To better characterize the role of NF‐κB in MEN 10755–induced cytotoxicity, we analyzed the expression of a number of genes that are known to be regulated by NF‐κB. None of these genes is modified by MEN 10755 treatment. On the contrary, our results suggest that the p53 DNA damage‐responsive pathway is fully activated in A2780 cells, several genes controlled by p53 being up‐ or downregulated according to the described action of p53 on their promoters. Thus, in the A2780 cell line, the role of p53 in transducing the DNA‐damage signal appears to be relevant, whereas NF‐κB, although activated, appears to be nonfunctional. Other human carcinoma cell lines besides A2780 activate NF‐κB DNA binding in response to MEN 10755 treatment, but again, this binding does not always lead to target gene activation. These results suggest that other factors, tumor type‐specific and different from mere activation, could influence NF‐κB transcriptional activity. Therefore, care should be taken when considering the pharmacologic inhibition of NF‐κB as a means to improve anticancer therapy efficacy. © 2002 Wiley‐Liss, Inc.
Expression of mitogen‐activated protein kinase phosphatase‐1 (MKP‐1) in primary human ovarian carcinoma
Authors: Denkert Carsten , Schmitt Wolfgang D. , Berger Stefan , Reles Angela , Pest Sören , Siegert Antje , Lichtenegger Werner , Dietel Manfred , Hauptmann Steffen
Published: November 2002

The mitogen‐activated protein kinase phosphatase‐1, MKP‐1 (CL100) is involved in inactivation of MAP‐kinase pathways, regulation of stress‐responses and suppression of apoptosis. We investigated expression of MKP‐1 in 90 cases of primary ovarian tumors, 11 normal ovaries as well as 4 ovarian carcinoma cell lines. Immunohistochemical expression of MKP‐1 protein was reduced in tissue from LMP tumors and invasive ovarian carcinomas compared to normal ovaries and cystadenomas. A moderate to strong expression of MKP‐1 was detected in 57.6% of invasive ovarian carcinomas. In a descriptive univariate survival analysis, MKP‐1 expression was a prognostic marker for shorter progression‐free survival of patients with invasive ovarian carcinomas. Patients with carcinomas positive for MKP‐1 had a median progression‐free survival of only 18.3 months compared to 40.6 months for patients with carcinomas negative for MKP‐1 (log‐rank test, p = 0.019). Other prognostic parameters for progression‐free survival were FIGO stage, grade and pT stage. In an exploratory multivariate analysis, we found that MKP‐1 expression as well as FIGO stage and grade were independent prognostic factors for progression‐free survival. In contrast to progression‐free survival, we did not find any influence of MKP‐1 expression on patient overall survival. We investigated expression and regulation of MKP‐1 mRNA by Northern Blot in vitro using 4 ovarian carcinoma cell lines (SKOV‐3, OVCAR‐3, CAOV‐3, OAW‐42). MKP‐1 mRNA was inducible by interleukin‐1β and tumor necrosis factor‐α in SKOV‐3 and OVCAR‐3 cells, whereas CAOV‐3 and OAW‐42 expressed MKP‐1 mRNA constitutively. In OVCAR‐3 cells MKP‐1 mRNA levels were strongly inducible upon treatment of cells with cisplatin. Our data indicate that MKP‐1 is expressed in a subset of ovarian carcinomas and regulated by inflammatory mediators. Expression of MKP‐1 may be associated with shorter progression‐free survival times. Further studies are needed to determine whether MKP‐1 expression is a clinically useful marker to estimate patient prognosis as well as the response to chemotherapy. © 2002 Wiley‐Liss, Inc.
Protein arginine methyltransferase I: Substrate specificity and role in hnRNP assembly
Authors: Pawlak Maciej R. , Banik‐Maiti Sarbani , Pietenpol Jennifer A. , Ruley H. Earl
Published: November 2002

Prmt1, the major protein arginine methyltransferase in mammalian cells, has been implicated in signal transduction, transcriptional control, and protein trafficking. In the present study, mouse embryonic stem cells homozygous for an essentially null mutation in the Prmt1 gene were used to examine Prmt1 activity and substrate specificity, which by several criteria appeared to be highly specific. First, other methyltransferases did not substitute for the loss of Prmt1 activity. Second, almost all proteins modified by recombinant Prmt1 in vitro were authentic substrates, i.e., proteins rendered hypomethylated by Prmt1 gene disruption. Finally, Prmt1 did not modify the substrates of other methyltransferases from cells treated with methyltransferase inhibitors. Recombinant proteins corresponding to two splice‐variants, Prmt1353 and Prmt1371, methylated different, proteins in vitro, providing the first evidence for functional differences between the two isoforms. However, the differences in substrate specificity were lost by the addition of an N‐terminal His6 tag. Loss of Prmt1 activity (and hypomethylation of hnRNPs) has no obvious effect on the formation or composition of hnRNP complexes. Finally, methylation of the most abundant Prmt1 substrates appeared to be extensive and constitutive throughout the cell cycle, suggesting the modification does not modulate protein function under normal growth conditions. J. Cell. Biochem. 87: 394–407, 2002. © 2002 Wiley‐Liss, Inc.
Expression pattern of alternatively spliced PECAM‐1 isoforms in hematopoietic cells and platelets
Authors: Wang Yongji , Sheibani Nader
Published: November 2002

PECAM‐1 (CD31) is a cell adhesion molecule that is highly expressed in the endothelium. Hematopoietic cells including platelets, monocytes, neutrophils, and some T cells also express moderate levels of PECAM‐1. PECAM‐1 undergoes alternative splicing generating a number of isoforms in the endothelium. However, the expression of PECAM‐1 isoforms in hematopoietic cells and platelets has not been determined. Here, we examined the expression pattern of PECAM‐1 isoforms in human and rodent hematopoietic cells and platelets by RT‐PCR and DNA sequencing analysis. Our results showed that multiple PECAM‐1 isoforms are expressed in a cell‐type and species‐specific pattern. We identified seven human PECAM‐1 isoforms, six murine PECAM‐1 isoforms, and four rat PECAM‐1 isoforms. The full‐length PECAM‐1 was the predominant isoform detected in human cells. The PECAM‐1 isoforms that lack exon 14 and 15 (Δ14&15) or Δ12,14&15 were the predominant isoform in rodent cells. In addition, we identified a novel PECAM‐1 isoform, Δ13&14, in human hematopoietic cells. Thus, hematopoietic cells express multiple isoforms of PECAM‐1 in a pattern similar to that observed in the endothelium of the same species. The regulated expression of these isoforms may be important during hematopoiesis and transendothelial migration. J. Cell. Biochem. 87: 424–438, 2002. © 2002 Wiley‐Liss, Inc.
Stress‐activated protein kinase/c‐Jun N‐terminal kinase (JNK) plays a part in endothelin‐1‐induced vascular endothelial growth factor synthesis in osteoblasts
Authors: Wang Xiaodan , Tokuda Haruhiko , Hirade Kouseki , Kozawa Osamu
Published: November 2002

We previously reported that endothelin‐1 (ET‐1) activates both p44/p42 mitogen‐activated protein (MAP) kinase and p38 MAP kinase in osteoblast‐like MC3T3‐E1 cells, and that not p44/p42 MAP kinase but p38 MAP kinase participates in the ET‐1‐induced vascular endothelial growth factor (VEGF) synthesis. In the present study, we investigated the involvement of stress‐activated protein kinase/c‐Jun N‐terminal kinase (JNK) in ET‐1‐induced VEGF synthesis in these cells. ET‐1 significantly induced the phosphorylation of JNK in a dose‐dependent manner in the range between 0.1 and 100 nM. SP600125, an inhibitor of JNK, markedly reduced the ET‐1‐induced VEGF synthesis. A combination of SP600125 and SB203580 additively reduced the ET‐1‐stimulated VEGF synthesis. SP600125 suppressed the ET‐1‐induced phosphorylation of JNK, while having no effect on the phosphorylation of p38 MAP kinase elicited by ET‐1. SB203580, an inhibitor of p38 MAP kinase, hardly affected the ET‐1‐induced phosphorylation of JNK. These results strongly suggest that JNK plays a role in ET‐1‐induced VEGF synthesis in addition to p38 MAP kinase in osteoblasts. J. Cell. Biochem. 87: 417–423, 2002. © 2002 Wiley‐Liss, Inc.
Cyclosporin A as a model antigen: immunochemical and structural studies
Authors: Altschuh Danièle
Published: November 2002

The immunosuppressant drug cyclosporin (Cs) A is a cyclic undecapeptide which has been used as a model antigen because structural information and a large number of analogs, modified at each of its 11 positions, were available. This review summarizes immunochemical and crystallographic studies of the interaction between the Fab of monoclonal antibody R45‐45‐11 and Cs. Three points are discussed: (1) the different conformations of CsA and the question of its biologically active form; (2) the Fab–CsA recognition mechanism; and (3) the relationship between structure and binding properties of CsA analogs. Copyright © 2002 John Wiley & Sons, Ltd.
Structural and functional comparisons between vanadium haloperoxidase and acid phosphatase enzymes
Authors: Littlechild Jennifer , Garcia‐Rodriguez Esther , Dalby Andrew , Isupov Misha
Published: November 2002

The crystallographic structures of both the vanadium chloroperoxidase and bromoperoxidase enzymes have been determined with either vanadium or phosphate bound at their active site. The amino acids that are involved in phosphate binding in the acid phosphatase enzymes and those that are coordinated to vanadium in the haloperoxidases appear to be conserved between the two classes of enzyme. The detailed active site architecture for enzymes that recognize and use either vanadium or phosphate will be discussed in relation to their proposed enzymatic mechanism. Copyright © 2002 John Wiley & Sons, Ltd.
A novel compact meandering stripline balun for balanced amplifiers with Bluetooth application
Authors: Lee Shu‐Chuen , Tsang Kim‐Fung
Published: November 2002

A novel compact meandering stripline balun for Bluetooth (2.4 GHz) application is reported. The proposed balun is an integral part of the printed circuit board (PCB). Such design reduces the cost and the manufacturing complexity. Analysis using Microwave Office showed that return loss was better than 15 dB and insertion loss was less than 0.6 dB for the full Bluetooth bandwidth. An integrated push–pull power amplifier (PA) of a Bluetooth transceiver that incorporates the balun at its output was designed and implemented. Measurement showed that the average output power of the PA using meandering stripline balun among the 79 channels was −0.86 dBm with a 2‐dB imbalance. Thus, performance was adequate for Bluetooth application and the design was feasible. In addition, a size reduction of 65% was obtained when compared to a half‐wavelength balun. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 423–425, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10627
A comparative study of light scattering from liquid crystal droplets
Authors: Kriezis Emmanouil E.
Published: November 2002

Light scattering from electrically small nematic liquid crystal droplets is routinely studied by methods based on the Rayleigh–Gans (RG) approximation. The error introduced by the Rayleigh–Gans approximation is critically assessed for radial, bipolar, and aligned spherical droplets. Comparisons are made with respect to the prediction of the finite‐difference time‐domain (FDTD) method for the above droplet configurations. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 437–441, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10632
A neural network approach to real‐time dielectric characterization of materials
Authors: Olmi R. , Pelosi G. , Riminesi C. , Tedesco M.
Published: November 2002

Artificial neural networks (ANNs) are proposed as an inversion approach in microwave measurement methods of the dielectric characteristics of materials. Reflection and transmission methods require a proper electromagnetic (EM) model of the measurement system, and solutions in terms of the material permittivity are usually in implicit form, requiring an inversion procedure that can be costly in terms of computing time. In such applications, the ANN approach is favorable in that the EM computations are performed during the off‐line training phase of the network. As an example of a real‐world application, the ANN approach is tested on a waveguide method for the measurement of permittivity in the X band for which a working solution is yet available, showing that the parameters of interest (permittivity and thickness of the material under measurement) can be obtained in real‐time with a negligible loss of accuracy. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 463–465, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10639
Systematic elaboration of trial function bases for the study of ridged circular waveguide discontinuities polarizer
Authors: Najid A. , Crampagne R. , Baudrand H. , Boukli‐Hacene N.
Published: November 2002

This paper presents a mixed method for the characterization of ridged circular waveguide discontinuities. The method is based on integral equations in combination with a scalar Green's function and a boundary element method for the calculation an arbitrary ridged circular waveguide's mode spectrum. The modes computed by this technique are used as trial function bases for the characterization of arbitrary ridged circular waveguide discontinuities. An improved variational multimodal formulation is used for the characterization of the step discontinuity. Coupling coefficients are evaluated by post processing of the matrices already used in the modes' determination, and the overall scattering matrix is obtained by cascading the impedance matrix of such a discontinuity. In order to validate this method, screws used in filter design and spectrum polarizer are modeled and the numerical results are verified by excellent agreement with published data. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 478–482, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10643
A bandpass filter using dielectric coaxial resonators with a temperature‐stable stepped‐impedance structure
Authors: Lim Sang‐Kyu , Kim Duck‐Whan , Lee Han‐Young , An Chul
Published: November 2002

In this paper, a bandpass filter using stepped‐impedance coaxial resonators is presented. Each stepped‐impedance resonator (SIR) is composed of ceramic/material to ensure temperature stability of the resonant frequency; one has a positive temperature coefficient of resonant frequency (τf), and the other has a negative τf. A capacitively coupled three‐pole bandpass filter is designed and fabricated to have a center frequency of 915 MHz and a passband bandwidth of 20 MHz. The improved temperature stability of this filter is demonstrated by experimental results. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 508–510, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10651
13C NMR and electron spin resonance analyses of the radical polymerization of diisopropyl itaconate
Authors: Hirano Tomohiro , Furuya Kazuhiro , Seno Makiko , Sato Tsuneyuki
Published: November 2002

Radical polymerizations of dialkyl itaconates were performed in benzene at 50 °C. The 13C NMR spectra of the obtained polymers indicated that intramolecular chain‐transfer reaction had taken place more frequently in the polymerizations of itaconates with bulkier ester groups as follows: isopropyl (i‐Pr) > n‐butyl (n‐Bu) ≈ ethyl (Et) > methyl (Me). In addition to the 13C NMR analysis, an electron spin resonance (ESR) analysis was conducted for polymerizations of diisopropyl itaconate, the ESR spectra of which consisted of two kinds of resonances due to the radicals with different conformations. It was assumed that the difference in conformation was attributable to the stereosequences near the propagating chain end because the relative intensity ratios of the resonances varied with the magnitude of the intramolecular chain‐transfer reaction, which was accompanied by a decrease in the syndiotacticity of the obtained poly(diisopropyl itaconate)s. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4513–4522, 2002
Ethylene/1‐octene copolymerization studies with in situ supported metallocene catalysts: Effect of polymerization parameters on the catalyst activity and polymer microstructure
Authors: Li Pi Shan Colin , Soares João B. P. , Penlidis Alexander
Published: November 2002

Ethylene and 1‐octene copolymerizations were carried out with an in situ supported rac‐[dimethylsilylbis(methylbenzoindenyl)] zirconium dichloride catalyst. In a previous study, it was found that some in situ supported metallocenes produced polyethylene/α‐olefin copolymers with broad and bimodal short chain branching distributions and narrow molecular weight distributions. The ability to produce polyolefins with multimodal microstructural distributions in a single metallocene and a single reactor is attractive for producing polymers with balanced properties with simpler reactor technology. In this study, a factorial experimental design was carried out to examine the effects of the polymerization temperature and ethylene pressure, the presence of hydrogen and an alkylaluminum activator, and the level of the comonomer in the feed on the catalyst activity, short chain branching distribution, and molecular weight distribution of the polymer. The temperature had the most remarkable effect on the polymer microstructure. At high 1‐octene levels, the short chain branching distribution of the copolymer broadened significantly with decreasing temperature. Several factor interactions, including the hydrogen and alkylaluminum concentrations, were also observed, demonstrating the sensitivity of the catalyst to the polymerization conditions. For this catalyst system, the responses to the polymerization conditions are not easily predicted from typical polymerization mechanisms, and several two‐factor interactions seem to play an important role. Given the multiple‐site nature of the catalyst, it has been shown that predicting the polymerization activity and the resulting microstructure of the polymer is a challenging task. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4426–4451, 2002
New fluorinated thermoplastic elastomers. I. The synthesis and thermal characteristics of α,ω‐dihydrosilane hybrid fluorinated polysiloxane precursors
Authors: Andre S. , Guida‐Pietrasanta F. , Rousseau A. , Boutevin B. , Caporiccio G.
Published: November 2002

The synthesis of new α,ω‐dihydrosilane hybrid fluorinated polysiloxanes is described via the polycondensation between a diallyl perfluorinated compound and tetramethyldisiloxane. Control over the size of the oligomers is possible when the reaction is performed in two steps. The length of the polysiloxane chains influences the glass‐transition temperature and the thermal stability of the fluorinated oligomers: the higher the length is, the higher the glass‐transition temperature and the thermal stability are. The synthesized compounds have been characterized with 1H, 19F, and 29Si NMR spectroscopy. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4485–4492, 2002
Facile synthesis of hyperbranched polyimides from A2 + BB′2 monomers
Authors: Liu Ye , Chung Tai‐Shung
Published: November 2002

Facile syntheses of hyperbranched polyimides were realized by the polymerization of A2 + BB′2 monomers, 2,2‐bis(3,4‐dicarboxylphenyl) hexafluoropropane dianhydride (6FDA) + 2,4,6‐triaminopyrimidine (TAP), performed by mixing the monomers together in N‐methylpyrrolidone at 17% w/v concentrations with molar ratios of 6FDA:TAP ranging from 1:1 to 2:1. The lower reactivity of 2‐amino as compared with 4‐/6‐amino in TAP, demonstrated by 1H NMR, was probably the main reason for no gelation formed during the polymerization although monomer conversions surpassed the theoretical gel points. Fourier transform infrared spectroscopy and NMR were used to verify the structures of the obtained polymers. 1H NMR analysis indicated the degrees of branching (DB) of the polymers increased from 36 to 83% with the molar ratios of 6FDA:TAP increasing from 1:1 to 2:1. Molecular weights were determined by gel permeation chromatography, and inherent viscosities were measured. Glass‐transition temperature values, determined by differential scanning calorimetry, decreased when DB increased, and thermogravimetric analysis reflected the excellent thermal stability of the obtained hyperbranched polyimides. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4563–4569, 2002
Ab initio investigation of the Young's modulus of polyamide‐6
Authors: Peeters Anik , Van Alsenoy C. , Bartha F. , Bogár F. , Zhang M.‐L. , Van Doren V.
Published: November 2002

The Young's modulus of the α form of polyamide‐6 has been calculated using the supermolecule model. The crystalline polymer was represented by a single‐chain molecule, divided into a head, body, and tail part. The body of the model contains an even number of polyamide‐6 units (4–16 units) and is representative for a polyamide‐6 chain. The periodicity of the system was not explicitly taken into account, but in a few tests the effect of a linear constraint has been evaluated. An n‐butyl and n‐pentyl group have been used as head and tail, respectively. In a number of additional calculations the length of the head and tail has been varied. For all supermolecule models the equilibrium and elongated structures have been optimized using ab initio Hartree–Fock calculations with a 6‐31G** basis set. From the energy values of the optimized structure a Young's modulus of 334 GPa has been extrapolated for both the unconstrained and linearly constrained models. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Advances in channel‐adaptive video streaming
Authors: Girod Bernd , Kalman Mark , Liang Yi J. , Zhang Rui
Published: November 2002

Despite the well‐known challenges of variations in throughput, delay, and packet loss over the Internet, video streaming has experienced phenomenal growth, owing to the extensive research in video coding and transmission. In this paper, we review several recent advances for channel‐adaptive video streaming that, we believe, will benefit the design of video streaming systems in the future. Employed in different components of the system, these techniques have the common objective of providing efficient, robust, scalable, and low‐latency streaming video. Firstly, by allowing the client to control the rate at which it consumes data, adaptive media playout can be used to reduce receiver buffering and therefore average latency, and provide limited rate scalability. Secondly, rate‐distortion optimized packet scheduling, a transport technique, provides a flexible framework to determine the best packet to send, given the channel behaviors, the packets' deadlines, their transmission histories, the distortion reduction associated with sending each packet, and the interpacket dependencies. Thirdly, at the source encoder, channel‐adaptive packet‐dependency control can greatly improve the error resilience of streaming video and reduce latency. Finally, we address the specific additional challenges for wireless video streaming. We consider three architectures for wireless video and discuss the utility of the reviewed techniques for each architecture. Copyright © 2002 John Wiley & Sons, Ltd.
Machiavellian Democracy: Controlling Elites with Ferocious Populism
Authors: McCormick John P.
Published: November 2002

This essay demonstrates that Niccolò Machiavelli’s political thought addresses the deficiencies of two opposite poles of contemporary democratic theory: As do formal or minimalist approaches, he specifies electoral mechanisms for elite control; and similar to substantive or civic culture approaches, he encourages more direct and robust modes of popular participation. On these grounds, I cull from Machiavelli’s Discourses a theory of democracy in which the populace selects the elites who will hold office but also constantly patrols them through extraelectoral institutions and practices, such as the tribunes of the people, public accusations, and popular appeals. Machiavelli adds to these institutional features of popular government an important cultural dimension: The people should despise and mistrust elites, and they should actively confront the injustice that elite governing inevitably entails. Finally, I explore the ramifications of this theory for debates over elite accountability in contemporary democratic theory.
Asymmetric Information and Legislative Rules: Some Amendments
Authors: Krishna Vijay
Published: November 2002

We reexamine the major tenets of the informational theory of legislative rules, focusing on the informational efficiency of rules with varying degrees of restrictiveness. When committees are heterogeneous, full efficiency is attainable under the unrestrictive open rule as well as the somewhat restrictive modified rule. In contrast, the restrictive closed rule always leads to inefficiencies. When committees are homogeneous, the situation is different. All equilibria are inefficient regardless of legislative rules, but the closed rule leads to greater informational efficiency than does the open rule. Furthermore, the efficiency gains under the closed rule more than offset distributional losses regardless of the degree of preference divergence. We also examine the incentives provided by the different rules for information acquisition and committee specialization.
The Sum of the Parts Can Violate the Whole
Authors: Saari Donald G.
Published: November 2002

We develop a geometric approach to identify all possible profiles that support specified votes for separate initiatives or for a bundled bill. This disaggregation allows us to compute the likelihood of different scenarios describing how voters split over the alternatives and to offer new interpretations for pairwise voting. The source of the problems—an unanticipated loss of available information—also explains a variety of other phenomena, such as Simpson’s paradox (a statistical paradox in which the behavior of the “parts” disagrees with that of the “whole”) and Arrow’s theorem from social choice.
Thucydides’ Theory of International Relations: A Lasting Possession. Edited by Lowell S. Gustafson. Baton Rouge: Louisiana State University Press, 2000. 262p. $55.00 cloth, $24.95 paper.
Authors: Bartlett Robert C.
Published: November 2002

Too often edited volumes are a farrago of barely related
essays that amount to the academic equivalent of the prover-
bial camel: a horse built by committee. Lowell S. Gustafson is
to be commended for compiling a coherent collection of
essays that are united not only by their common conviction
that Thucydides' great work does indeed possess a "theory of
international relations" but also by their common desire to
contrast this theory with current trends in the discipline.
According to the contributors, Thucydides is not the father of
"realism" or its variants because his understanding of inter-
national politics is essentially moral: Every approach to
international politics that studies power to the neglect of
justice, necessity to the neglect of freedom, will prove to be
an inadequate tool with which to understand the political
deeds of human beings. However much we may be impinged
upon by necessity, we remain fundamentally free, and how-
ever much we may seek brute power, we nonetheless also
strive to be just.
Truth v. Justice: The Morality of Truth Commissions. Edited by Robert I. Rotberg and Dennis Thompson. Princeton, NJ: Princeton University Press, 2000. 309p. $55.00 cloth, $18.05 paper.
Authors: Nobles Melissa
Published: November 2002

Scholarship is substantial and growing on "transitional jus-
tice," that is, the legal and political decisions devised by
incoming democratizing regimes to address the excesses of
outgoing repressive regimes and the harms endured by their
victims. Truth commissions are perhaps the most significant,
if controversial, innovations in a democratizing regime's
toolbox. Their significance is largely derived from their
peculiarity. Since the early 1970s, approximately 21 commis-
sions have been established in various countries. They have
been defined as "bodies set up to investigate a past history of
violations of human rights in a particular country-which can
include violations by the military or other government forces
or by armed opposition forces" (Priscilla Hayner, "Fifteen
Truth Commissions-1974 to 1994: A Comparative Study,"
Human Rights Quarterly 16 [November 1994]: 597-655).
Democracy, Justice, and the Welfare State: Reconstructing Public Care. By Julie Anne White. University Park: Pennsylvania State University Press, 2000. 173p. $35.00, cloth, $17.95 paper.
Authors: Hanson Russell L.
Published: November 2002

Modern welfare states offer cash payments, public housing,
medical assistance, food subsidies, and a wide range of social
services to needy individuals. The assistance is rendered by
professional social workers and administrators who have the
authority (and responsibility) to determine who is needy,
what their needs are, and how those needs can be met
equitably and efficiently. This top-down approach is both
ineffective and paternalistic, according to Julie Anne White,
who advocates a system of care based on democratic delib-
eration rather than bureaucratic rationality.
Stations of the Cross: Adorno and Christian Right Radio. By Paul Apostolidis. Durham, NC: Duke University Press, 2000. 273p. $54.95 cloth, $18.95 paper.
Authors: Olson Laura R.
Published: November 2002

By now most readers have a good deal of familiarity with the
Christian Right, the political movement of conservative
Protestants that began in the late 1970s and continues to
thrive today. The movement has undergone significant
changes over the past two decades. Interest groups have risen
and fallen, and presidential candidacies (namely, that of Pat
Robertson in 1988) have failed. Yet, the Christian Right is
still seen by scholars, pundits, and electioneers alike as a
political force with which to be reckoned.
Congress and the Foreign Policy Process: Modes of Legislative Behavior. By Cecil V. Crabb, Jr., Glenn J. Antizzo, and Leila E. Sarieddine. Baton Rouge: Louisiana State University Press, 2000. 280p. $39.95 cloth, $24.95 paper.
Authors: Michelson Melissa R.
Published: November 2002

Marie Henehan presents a systematic study of every roll call
vote on foreign policy taken by the Senate between 1897 and
1984. She predicts an increase in Senate activity and disagree-
ment on foreign policy after "the emergence of imperialism
as a critical issue in 1897, the crisis over involvement in Europe
in 1917, the heightened importance of the response to commu-
nism in 1947, and the perceived failure of the containment
policy in Vietnam between the Tet Offensive in 1968 and the
bombing of Cambodia in 1970" (p. 83). She also predicts a
gradual decline in activity as the issue is resolved, but increases
following major policy failures related to each critical issue.
Uneasy Alliances: Race and Party Competition in America. By Paul Frymer. Princeton, NJ: Princeton University Press, 1999. 214p. $16.95 paper.
Authors: Reiter Howard L.
Published: November 2002

The multiracial extravaganza staged at the 2000 Republican
convention reminds us of the centrality of race in our
national politics. In a work that effectively challenges cher-
ished notions of how the political system functions, Paul
Frymer argues that through most of U.S. history the major
parties have lacked incentives to promote the interests of
African Americans.
Making Americans: Immigration, Race, and the Origins of a Diverse Democracy. By Desmond King. Cambridge, MA: Harvard University Press, 2000. 320p. $45.00.
Authors: Barvosa-Carter Edwina
Published: November 2002

Desmond King offers a richly researched, skillfully written
account of the development of a race-based U.S. immigration
policy during the 1920s. The shift to a "national origins"
immigration policy is linked to domestic racial and ethnic
politics and especially to racial segregation. Moreover, King
contends that a grasp of the immigration debates and policies
of the 1920s is instrumental to understanding contemporary
racial and ethnic politics, including the controversies sur-
rounding multiculturalism.
Representing Women: Sex, Gender, and Legislative Behavior in Arizona and California. By Beth Reingold. Chapel Hill: University of North Carolina Press, 2000. 338p. $55.00 cloth, $19.95 paper.
Authors: Palley Marian Lief
Published: November 2002

Beth Reingold questions some of the conventional wisdom
regarding women representing women and their interests.
She does this by comparing the legislative behavior of women
in the Arizona and California state legislatures in 1990, and
she provides an understanding of the consequences and
implications of electing women to public office. Reingold is
interested in what these trends mean for the political repre-
sentation of women in the United States, and it is this
concern that focuses the volume.
Does Business Learn?: Tax Breaks, Uncertainty, and Political Strategies. By Sandra L. Suarez. Ann Arbor: University of Michigan Press, 2000. 192p. $47.50.
Authors: Smith Mark A.
Published: November 2002

Sandra Suarez sets out to understand why corporations
choose certain political strategies rather than others. She
argues that firms want to maximize profits and recognize that
politics affects their ability to do so, but they cannot easily
translate their interests into concrete political strategies.
Building Democracy in South Asia: India, Nepal, Pakistan. By Maya Chadda. Boulder, CO: Lynne Rienner, 2000. 247p. $49.95 cloth, $19.95 paper.
Authors: Tepper Elliot L.
Published: November 2002

Democracy is in vogue it seems. Everywhere in the world, the
forces opposed to democracy seem to be in retreat, and the
number of states calling themselves democracies is increas-
ing. There are exceptions, of course: parts of Africa, tortured
Burma, all over the Middle East, some aging Communist
oligarchies, a few proud holdouts in sultanates and mountain
monarchies. But they are increasingly anachronisms in the
end-of-history world. Or are they? The literature is replete
with controversy on the definition, durability, inevitably, and
universality of democracy. Into this controversy comes a new
book that takes direct aim at the literature of the past
decades and provides a badly needed comparative analysis of
some of the states in South Asia. Maya Chadda's goals are
clear and ambitious: to bring the neglected experience of
South Asia to the attention of a wider audience, in the
context of the most central debates about the nature of
democracy.
State Legitimacy and Development in Africa. By Pierre Englebert. Boulder, CO: Lynne Rienner, 2000. 243p. $55.00.
Authors: Scarritt James R.
Published: November 2002

In this well-informed, theoretically and methodologically
sophisticated, and highly innovative book, and in related
articles that appeared recently in Political Research Quarterly
(53 [March 2000]: 7-36) and World Development (28 [Octo-
ber 2000]: 1821-35), Pierre Englebert proposes and tests the
hypothesis that variations in vertical and horizontal state
legitimacy account for variations in the developmental capac-
ity and economic growth of African states and of Africa in
comparison to other world regions. Developmental capacity,
which combines an index of specific economic policies (em-
phasizing a free market and human capital) and an index of
good governance, is the crucial intervening variable between
state legitimacy and growth.
Closing the Shop: Information Cartels and Japan’s Mass Media. By Laurie Anne Freeman. Princeton, NJ: Princeton University Press, 2000. 256p. $39.50.
Authors: Maclachlan Patricia L.
Published: November 2002

Although Japan scholars have long been aware that media
institutions facilitate state efforts to curtail the free flow of
information within Japanese society, Closing the Shop is the
first comprehensive treatment of this important topic. The
book was well worth the wait.