bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiretroviral drug resistance among HIV‐1 infected children failing treatment
Authors: Mullen Jane , Leech Susan , O'Shea Siobhan , Chrystie Ian L. , du Mont Gillian , Ball Colin , Sharland Michael , Cottam Fiona , Zuckerman Mark , Rice Philip , Easterbrook Philippa
Published: October 2002

High levels of HIV‐1 replication occur following perinatal infection and antiretroviral drugs may not fully suppress viral load during the early years of childhood. Adherence to treatment may also be difficult among children. These two factors will contribute to development of drug resistance but limited paediatric data are available. This study has, therefore, evaluated the prevalence of drug resistance among children and assessed the contribution of adherence to failing therapy. Samples from 26 children who had experienced virological failure to antiretroviral therapy were tested for drug resistance using the Visible Genetics TRUGENE™ HIV‐1 genotyping assay. HIV‐1 subtype was determined using a peptide‐based EIA and drug adherence determined by physician assessment. Twenty‐four children were black African, 23 of whom were infected with a non‐B subtype. HIV RNA sequence data was obtained for 21 of the 26 children; at treatment failure resistance mutations were detected in the protease gene of 7 (33%) and the reverse transcriptase gene of 19 (90%). A lower proportion of children had evidence of drug resistance at nadir and no resistance mutations were detected prior to treatment. Genotypic resistance was common in those treated with lamivudine (10/11, 91%), nevirapine (6/8, 75%), and zidovudine (7/11, 64%). The prevalence of mutations was lower among those receiving other nucleoside reverse transcriptase inhibitors and protease inhibitors. In 50% of children, drug adherence was >90%. Antiretroviral drug resistance was common among this group of children failing therapy, the majority of whom were infected with non‐B subtypes of HIV‐1. As adherence to treatment was low in 50%, this was likely to be an important contributory factor. J. Med. Virol. 68:299–304, 2002. © 2002 Wiley‐Liss, Inc.
Antibody responses to Epstein‐Barr virus‐encoded latent membrane protein‐1 (LMP1) and expression of LMP1 in juvenile Hodgkin's disease
Authors: Meij Pauline , Vervoort Marcel B.H.J. , Bloemena Elisabeth , Schouten Tabitha E. , Schwartz Cindy , Grufferman Seymour , Ambinder Richard F. , Middeldorp Jaap M.
Published: October 2002

A large group of juvenile Hodgkin's disease patients (n = 242, mean age 11.7 years, 75% [n = 181] seropositive) was evaluated for anti‐Epstein‐Barr virus (EBV) antibody responses and the presence of EBV‐encoded EBER‐RNA and latent membrane protein‐1 (LMP1)‐protein expression in the tumor. The molecular diversity of anti‐EBV antibody responses in Hodgkin's disease patients with EBV‐positive and‐negative tumors was studied by enzyme‐linked immunosorbent assay (ELISA) and immunoblot. Using purified recombinant LMP1 protein as antigen, the presence of antibodies to LMP1 was related to expression of LMP1 in the tumor cells and specific EBV‐serological patterns. Antibodies to LMP1 were detected in 30% of the EBV‐seropositive Hodgkin's disease patients. The presence of antibodies to LMP1 was not associated with a distinct anti‐EBV antibody diversity profile (ELISA), but a significantly higher percentage of patients with antibodies to LMP1 had antibodies to ZEBRA and viral capsid antigen (VCA)‐p18 (Immunoblot). Significantly more patients with an EBV‐positive tumor had detectable antibody responses to LMP1, but the presence of antibodies to LMP1 did not reflect the expression of LMP1 protein in the tumor cells. Interestingly, all patients with the strongest antibody responses to LMP1 had EBV‐negative tumors, suggesting immunological selection in vivo. J. Med. Virol. 68:370–377, 2002. © 2002 Wiley‐Liss, Inc.
Enhancing the antitumoral effect of hypericin‐mediated photodynamic therapy by hyperthermia
Authors: Chen Bin , Roskams Tania , de Witte Peter A.M.
Published: October 2002

Background and Objectives

In the previous study, we have found a synergistic effect on the RIF‐1 tumor cell killing when hypericin‐mediated photodynamic therapy (PDT) was combined with hyperthermia. The purpose of the present study was to investigate the antitumoral effect of hypericin‐PDT in combination with hyperthermia in the RIF‐1 mouse tumor model.

Study Design/Materials and Methods

Tumor response to PDT in combination with hyperthermia was compared to the response to PDT or hyperthermia alone. To explore the possible mechanism involved in the interaction of PDT and hyperthermia, we determined the tumor cell survival by in vivo/in vitro cell survival assay and analyzed the functional blood vessels by Hoechst 33342 staining. The mode of cell death was examined by TUNEL assay.

Results

Enhanced tumor response was obtained by PDT immediately followed by hyperthermia. Tumor cell survival assay revealed that indirect vascular effect contributed greatly to the overall tumor cell death induced by PDT with hypericin, whereas direct tumor cytotoxicity played a major role in hyperthermia‐induced tumor cell killing. Combining PDT with hyperthermia brought about a synergistic interaction on direct tumor cell killing. Even though PDT or hyperthermia alone induced severe blood vessel shutdown and the combined treatments led to significant potentiation of the vascular damage as examined by Hoechst staining, the gain in tumor cell death as a result of this secondary vascular effect was limited after the combined treatments. Following the cellular damage by PDT in combination with hyperthermia, tumor cells were triggered to undergo apoptosis.

Conclusions

Our study demonstrated the possibility of using hyperthermia to potentiate the antitumoral effect of hypericin‐mediated PDT. Lasers Surg. Med. 31:158–163, 2002. © 2002 Wiley‐Liss, Inc.
The body consumed: Reflexivity and cosmetic surgery
Authors: Askegaard Søren , Gertsen Martine Cardel , Langer Roy
Published: October 2002

We live in a time with increasing focus on the body and its perfection. The marketing environment is replete with products and services catering to the health, well‐being, and beauty of bodies and, it is implied, of our souls. One of the more drastic and consequently also much debated and, at times, tabooed type of service and consumption within this field is cosmetic surgery. This article is based on interviews with 15 women who have had cosmetic operations. It examines what motivated their decision to have surgery; some of their thoughts and feelings before, during and after the process; and the ways in which the operation has influenced their life and self‐identity subsequently. The material is analysed within a theoretical framework resting mainly on Anthony Giddens' work on self‐identity in late modernity. This implies that cosmetic surgery is understood to be part of the individual's reflexive construction of self‐identity, and leads to a focus on issues such as self‐determination, self‐esteem, and the relationship between body and identity. Finally, some relations between self‐identity and the marketing institution are discussed. © 2002 Wiley Periodicals, Inc.
Customer familiarity and its effects on satisfaction and behavioral intentions
Authors: Söderlund Magnus
Published: October 2002

When customer familiarity increases, customer expertise is likely to increase. Although expertise is known to affect information processing in several ways, few studies have examined the effects of familiarity on customers' evaluations and behavioral intentions. In this study, it was found that a high level of prepurchase familiarity was associated with more extreme (i.e., more polarized) postpurchase responses in customer satisfaction, repurchase intentions, and word‐of‐mouth intentions compared to a low prepurchase level of familiarity. More specifically, when service performance was high, high‐familiarity customers expressed a higher level of satisfaction and behavioral intentions than did less familiar customers. On the other hand, when performance was low, high‐familiarity customers expressed lower levels of satisfaction and behavioral intentions than did low‐familiarity customers. © 2002 Wiley Periodicals, Inc.
Structure and expression of the follicle‐stimulating hormone receptor gene in a marsupial, Macropus eugenii
Authors: Mattiske D. , Pask A.J. , Shaw J.M. , Shaw G.
Published: October 2002

Follicle stimulating hormone (FSH) is essential for folliculogenesis. The function of FSH is mediated through its receptor (FSHr) and modulation of the receptor is thought to be the mechanism by which the responsiveness of follicles to gonadotrophins is regulated. FSHr is alternatively spliced to produce several transcripts in all eutherian species studied. However, controversy exists over the significance of alternatively spliced transcripts. In this study, we cloned and characterised the tammar wallaby (Macropus eugenii) FSHr gene and examined its expression. Comparison of gene structure and function between marsupials and eutherians enables identification of conserved features that are likely to be of functional significance. Tammar FSHr shares 94% amino acid similarity with human FSHr and is expressed in both the adult testis and ovary suggesting a similar function for this gene in both marsupials and eutherians. Tammar FSHr undergoes alternate splicing to produce four transcripts consistent with the splice variants seen in eutherians. These results strongly suggest that alternate splicing is of functional significance in the ovary since it has remained a highly conserved character of this gene for over 100 million years of divergent evolution.Mol. Reprod. Dev. 63: 24–31, 2002. © 2002 Wiley‐Liss, Inc.
The epidemiology of developmental disabilities in low‐income countries
Authors: Durkin Maureen
Published: October 2002

Although most of the world's children live in developing countries and may be at high risk for disability, very little is known about the prevalence and causes of developmental disabilities in these countries. This paper discusses methodological difficulties contributing to this lack of knowledge, and provides an overview of what is known about the epidemiology of developmental disabilities in low‐income countries. At least some forms of developmental disability appear to be more common in low‐income countries than in wealthier countries, despite the probability of higher mortality among children with disabilities in low‐income countries. For example, most studies of severe mental retardation in low‐income countries report prevalences greater than 5 per 1,000 children, while prevalence estimates from industrialized countries are consistently below this. Major risk factors for developmental disabilities in some low‐income countries include specific genetic diseases, a higher frequency of births to older mothers, consanguinity, and specific micronutrient deficiencies and infections. Trauma and toxic exposures are also important risk factors, but their contributions to the etiology of developmental disabilities in low‐income countries are not well documented. Though many of the causes of developmental disabilities are understood and preventable, proven methods of prevention are not being fully implemented in developing countries. Epidemiologic studies are needed to raise awareness of the public health impacts of developmental disabilities in low‐income countries and to provide a basis for setting priorities and designing efficient interventions. MRDD Research Reviews 2002;8:206–211. © 2002 Wiley‐Liss, Inc.
Psychometric characteristics of dyspnea descriptor ratings in emergency department patients with exacerbated chronic obstructive pulmonary disease
Authors: Parshall Mark B.
Published: October 2002

The purpose of this study was to evaluate the reliability, content validity, and factor structure of dyspnea sensory quality descriptor ratings in emergency department (ED) patients with exacerbated chronic obstructive pulmonary disease (COPD). During an ED visit 104 patients with COPD rated the intensity of 16 dyspnea sensory quality descriptors (numerical ratings of 0–10) in relation to how they felt when they decided to come to the ED (Decision) and 1 week before the visit. Content validity of 15 descriptors was supported. Factor analysis of Decision ratings resulted in seven descriptors and three factors (α=.88; 74% common variance): Smothering/Suffocating/Hunger for air (α=.87); Effort/Work (α=.87); and Tight/Constricted (α=.74). Results indicate that the intensity of sensory quality descriptors can be measured reliably in COPD patients during an exacerbation of COPD. The initial descriptor list of descriptors could be cut by more than half while retaining satisfactory psychometric properties. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:331–344, 2002
Spine length measurement in the first trimester of pregnancy
Authors: De Biasio P. , Ginocchio G. , Vignolo M. , Ravera G. , Venturini P. L. , Aicardi G.
Published: October 2002

Objectives

The aim of the study was to evaluate spine length as an indicator of skeletal growth in the first trimester of pregnancy and to provide a nomogram of spine length at the end of the first trimester of pregnancy.

Methods

The study was carried out on 420 single pregnancies, at gestational ages ranging from 11 to 14 weeks, using high‐resolution transabdominal echography. Biparietal diameter and crown–rump length (CRL) were measured to date the pregnancy. Using the same scanning plane used to measure CRL, the whole spine length in antero‐dorsal position can be visualized as a double hyperechoic line from 10 weeks of gestation onwards. Spine length was measured three times by one observer and the mean of the three measurements was considered as definitive. Forty fetuses had multiple measurements for interobserver and intraobserver error analysis.

Results

Linear relationship between spine length, and gestational age, biparietal diameter and CRL were demonstrated. Spine length (millimetres) as a function of gestational age (days) was expressed by the regression equation: spine length = 1.09 × (gestational age in days) −60.56, with a determination coefficient of R2 = 0.744. Spine length ranged from 21.5 mm at 11 weeks to 41.9 mm at 14 weeks.

Conclusion

The data obtained showed that spine length increased progressively from the end of the first trimester to the beginning of the second. A high correlation between spine length, gestational age, biparietal diameter, and CRL was observed. Spine length measurement could therefore be considered a good indicator of fetal growth. Copyright © 2002 John Wiley & Sons, Ltd.
Rapid and controlled deswelling of porous poly(N‐isopropylacrylamide) hydrogels prepared by the templating of interpenetrated nanoporous silica particles
Authors: Serizawa Takeshi , Uemura Masami , Kaneko Tatsuo , Akashi Mitsuru
Published: October 2002

Free radical polymerization of N‐isopropylacrylamide (NIPAAm) and crosslinker solutions, which were fulfilled in silica particles with an interpenetrated and nanometer‐sized porous structure (a diameter of 3 mm and mean pore sizes of 15, 30, and 50 nm), fabricated hybrids of organic hydrogels and inorganic silica. Differential scanning calorimetric analyses of the hybrids revealed that silica components affected the thermoresponsive properties of polyNIPAAm hydrogels. Porous polyNIPAAm hydrogels were prepared by the subsequent acid treatment of the hybrids to remove silica. Transmission Fourier transformed infrared spectra indicated the selective extraction of silica. Scanning electron microscopic observation of the hydrogels confirmed the porous structure. The deswelling rate of porous hydrogels was 7 times larger than that of conventional hydrogels and increased with increasing the pore size of silica used. However, the swelling was not affected by the pore formation. The thermoresponsiveness of porous polyNIPAAm hydrogels could be regulated by the pore size. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3542–3547, 2002
Poly(aryl ether ketone)s with (3‐methyl)phenyl and (3‐trifluoromethyl)phenyl side groups
Authors: Liu Baijun , Wang Guibin , Hu Wei , Jin Yuhui , Chen Chunhai , Jiang Zhenhua , Zhang Wanjin , Wu Zhongwen , Wei Yen
Published: October 2002

New bisphenol monomers, (3‐methyl)phenylhydroquinone and (3‐trifluoromethyl)phenylhydroquinone, were prepared in a two‐step synthesis. A series of poly(aryl ether ketone)s were derived from these bisphenols via a nucleophilic aromatic substitution polycondensation with various bisfluoro compounds. The polycondensation proceeded quantitatively in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the polymers with inherent viscosities of 0.63–0.91 dL/g. The fluorinated polymers showed lower glass‐transition temperatures and higher thermal‐decomposition temperatures than the corresponding nonfluorinated polymers. The solubility of the polymers was improved by the introduction of bulky pendant groups. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 86.4–102.0 MPa, Young's moduli of 2.28–3.03 GPa, and elongations at break of 14–42%. All the polymers had low dielectric constants of 2.70–2.83 at 1 MHz. Compared with the methylated polymers, the trifluoromethylated polymers exhibited lower water sorption, which was attributed to the stronger hydrophobicity of the fluorine‐containing groups. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3392–3398, 2002
Bimodal molecular weight distribution formed in the emulsion polymerization of ethylene
Authors: Tobita Hidetaka
Published: October 2002

It is known that the molecular weight distribution (MWD) formed in an emulsion polymerization of ethylene can be bimodal. However, the origin of the bimodality has not been elucidated. In this article, a Monte Carlo simulation is conducted, mostly with parameters reported in the literature. The simulated MWDs are bimodal because of the limited volume effect; that is, the high molecular weight profiles are distorted by the small particle size, which is comparable to the size of the largest branched polymer molecule in a particle. The simulated MWDs agree reasonably well with the experimentally obtained MWDs. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3426–3433, 2002
Synthesis of comb‐shaped poly(methyl methacrylate)‐b‐poly(polytetrahydrofuran acrylate) under 60Co γ‐ray irradiation
Authors: He Tao , Zou Ying‐Fang , Pan Cai‐Yuan
Published: October 2002

Comb‐shaped graft copolymers with poly(methyl methacrylate) as a handle were synthesized by the macromonomer technique in two steps. First, polytetrahydrofuran acrylate (A‐PTHF), prepared by the living cationic ring‐opening polymerization of tetrahydrofuran, underwent homopolymerization with 1‐(ethoxycarbonyl)prop‐1‐yl dithiobenzoate as an initiator under 60Co γ irradiation at room temperature; Second, the handle of the comb‐shaped copolymers was prepared by the block copolymerization of methyl methacrylate with P(A‐PTHF) as a macroinitiator under 60Co γ irradiation. The two‐step polymerizations were proved to be controlled with the following evidence: the straight line of ln[M]0/[M] versus the polymerization time, the linear increase in the number‐average molecular weight with the conversion, and the relatively narrow molecular weight distribution. The structures of the P(A‐PTHF) and final comb‐shaped copolymers were characterized by 1H NMR spectroscopy and gel permeation chromatography. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3367–3378, 2002
Synthesis and characterization of soluble copoly(ether ketone)s containing double bonds
Authors: Gao Yan , Jian Xigao , Xuan Yingnan , Xiang Sheng , Liang Ping , Guiver Michael D.
Published: October 2002

A series of copoly(ether ketone)s containing double bonds along the polymer chains were synthesized from the condensation polymerization of hydroquinone with 4,4′‐difluorobenzophenone and 4,5‐bis(4‐fluorobenzoyl)‐1‐methylcyclohexene in sulfolane containing anhydrous potassium carbonate. The presence of methylcyclohexene in the polymer chains resulted in an improvement in the solubility of poly(ether ketone)s in organic solvents such as chloroform, chlorobenzene, and sulfolane. As a result, the conditions for synthesizing these polymers were much milder than those for poly(ether ether ketone). The new copoly(ether ketone)s also showed good tensile properties and reasonable thermal stability. New polyethers containing pyrazine unites were obtained from the cyclization reaction of these copoly(ether ketone)s with hydrazine. The hydrazine cycloderivatives led to an increase in the glass‐transition temperatures and a decrease in solubility in organic solvents. © 2002 Government of Canada. Exclusive world‐wide publication rights in the article have been transferred to Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3449–3454, 2002
Reactions and structural changes during thermal annealing in a semicrystalline, aromatic diacetylene‐containing polyester
Authors: Hu Xiao , Li Xiqiang
Published: October 2002

Thermally induced solid‐state reactions and microstructure changes in a high molar mass, semicrystalline, aromatic diacetylene‐containing polyester, poly[2,4‐hexadiyn‐1,6‐ylene terephthalate], were investigated with a combination of laser Raman spectroscopy, differential scanning calorimetry, and wide‐angle X‐ray diffraction analysis. The study has provided some new insights into the rather complex solid‐state reactions in the semicrystalline diacetylene‐containing polyester. Results suggest that, in addition to the usual desired solid‐state topochemical crosspolymerization in the crystalline region, a certain degree of random crosslinking reaction occurs in the amorphous region, especially when the annealing is carried out above the glass transition. After prolonged annealing or annealing at a higher temperature, a further reaction involving the formed polydiacetylene chains may occur, as evident from the reduction in crystallinity and even complete loss of crystallinity. An attempt has been made to separate the contribution of the topochemical reaction from the overlapping exothermic activities in the differential scanning calorimetry curves via subtraction. This allows the monitoring of the crystalline‐phase solid‐state topochemical crosspolymerization. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2354–2363, 2002
Molecular motions and conformational changes of HPPK
Authors: Keskin O. , Ji X. , Blaszcyk J. , Covell D.G.
Published: October 2002

6‐Hydroxymethyl‐7,8‐dihydropterin pyrophosphokinase (HPPK) belongs to a class of catalytic enzymes involved in phosphoryl transfer and is a new target for the development of novel antimicrobial agents. In the present study, the fundamental consideration is to view the overall structure of HPPK as a network of interacting residues and to extract the most cooperative collective motions that define its global dynamics. A coarse‐grained model, harmonically constrained according to HPPK's crystal structure is used. Four crystal structures of HPPK (one apo and three holo forms with different nucleotide and pterin analogs) are studied with the goal of providing insights about the function‐dynamic correlation and ligand induced conformational changes. The dynamic differences are examined between HPPK's apo‐ and holo‐forms, because they are involved in the catalytic reaction steps. Our results indicate that the palm‐like structure of HPPK is nearly rigid, whereas the two flexible loops: L2 (residues 43–53) and L3 (residues 82–92) exhibit the most concerted motions for ligand recognition and presumably, catalysis. These two flexible loops are involved in the recognition of HPPKs nucleotide and pterin ligands, whereas the rigid palm region is associated with binding of these cognate ligands. Six domains of collective motions are identified, comprised of structurally close but not necessarily sequential residues. Two of these domains correspond to the flexible loops (L2 and L3), whereas the remaining domains correspond to the rigid part of the molecule. Proteins 2002;49:191–205. Published 2002 Wiley‐Liss, Inc.
Evaluating CASP4 predictions with physical energy functions
Authors: Feig Michael , Brooks Charles L.
Published: October 2002

Physical energy scoring functions based on implicit solvation models are tested by evaluating predictions from the most recent CASP4 competition. The best performing scoring functions are identified along with the best protocol for preparing structures before energies are evaluated. Ranking of structures with the best scoring functions is compared across CASP4 targets to establish when physical scoring functions can be expected to reliably distinguish structures that are most similar to the native fold in a set of misfolded or unfolded protein conformations. The results are used to interpret previous studies where scoring functions were tested on the standard decoy sets by Park, Levitt, and Baker. We show that the best physical scoring functions can be applied successfully in automated consensus scoring applications where a single best conformation has to be selected from a set of structures from different sources. Finally, the potential for better protein structure scoring functions is discussed with a suggestion for an empirically parameterized linear combination of energy components. Proteins 2002;49:232–245. © 2002 Wiley‐Liss, Inc.
Susceptibility of field‐collected populations of the Southwestern corn borer, Diatraea grandiosella, to Bacillus thuringiensis
Authors: Trisyono Y Andi , Chippendale G Michael
Published: October 2002

The susceptibility of newly hatched larvae of laboratory‐adapted and field‐collected populations of the Southwestern corn borer, Diatraea grandiosella (Dyar) (Lepidoptera: Crambidae), to a Bacillus thuringiensis protein (Cry1Ab) was examined using a larval feeding bioassay. D grandiosella populations were collected from five states: Missouri, Kansas, Texas, Tennessee and Kentucky. Using larval mortality as the end‐point of the bioassay, the magnitude of differences in the susceptibility of the laboratory‐adapted and the field‐collected populations to Cry1Ab protein varied from one to 46 times depending on the time of observation and the standard of comparison (LC50 or LC95). However, significant differences in susceptibility to Cry1Ab protein among these populations were not detected when the comparisons were based on growth inhibition (EC50 or EC95); the magnitude of differences was less than fourfold. Either using larval mortality or larval growth inhibition, the results indicated that the field‐collected populations of D grandiosella were susceptible to Cry1Ac, and differences in susceptibility may reflect natural variation among populations. The bioassay using larval growth inhibition offers advantages over that using larval mortality, including giving more accurate representation of the toxicological effects of the toxin.

© 2002 Society of Chemical Industry
Experimental and numerical study of sorption/diffusion of esters into polypropylene packaging films
Authors: Safa Laurent , Abbes Boussad
Published: October 2002

The sorption and diffusion of four esters into polypropylene packaging films immersed in four different solutions have been studied by the FTIR method at 45°C. Kinetic curves have been generated for these systems to compute diffusion coefficients. The calculated results are discussed in terms of size and shape of diffusing molecules into a polymer film. Isovalues and profiles of liquid concentrations have been calculated by solving Fick's diffusion equation using a numerical method based on a two‐dimensional finite element method. Copyright © 2002 John Wiley & Sons, Ltd.
Statistical modelling of predicted non‐stationary vehicle vibrations
Authors: Rouillard V. , Sek M. A.
Published: October 2002

This paper describes a method to predict the vertical vibrations of road vehicles from measured pavement profiles. It discusses the limitations of current methods used for analysing and simulating vehicle vibrations and shows that more accurate characterization and simulation of the transport environment must take into account the non‐stationary nature of road vehicle vibrations. Vertical vibrations for typical transport vehicles under various operating conditions and pavement profiles are predicted using a computer model of the vehicle characteristics and analysed to produce the spectral and statistical characteristics. The paper also presents an improved method to compute the vibration intensity by using a dynamic segmentation data reduction technique. The effectiveness of the procedure to characterize the non‐stationarity of random vehicle vibrations is demonstrated. Finally, the paper deals with the statistical distribution of the vibration intensity and demonstrates how it can be adapted to a technique for the simulation the non‐stationary nature of random vehicle vibrations. Copyright © 2002 John Wiley & Sons, Ltd.
Mechanistic investigation of the interaction between bisquaternary antimicrobial agents and phospholipids by liquid secondary ion mass spectrometry and differential scanning calorimetry
Authors: Pashynskaya V. A. , Kosevich M. V. , Gömöry A. , Vashchenko O. V. , Lisetski L. N.
Published: October 2002

Mechanisms of interaction between the antimicrobial drugs decamethoxinum and aethonium, which are based on bisquaternary ammonium compounds, and a phospholipid component of biological membranes, dipalmitoylphosphatidylcholine, were studied by means of liquid secondary ion mass spectrometry (LSIMS) and differential scanning calorimetry (DSC). Supramolecular complexes of the drugs with this phospholipid were recorded under secondary ion mass spectrometric conditions. The dependence of the structures of these complexes on structural parameters of the dications of the bisquaternary ammonium compounds was demonstrated. Tandem mass spectrometric investigations of the metastable decay of doubly charged ions of decamethoxinum and aethonium complexes with dipalmitoylphosphatidylcholine allowed estimation of structural parameters of these complexes in the gas phase. Interactions of decamethoxinum and aethonium with model membrane assemblies built from hydrated dipalmitoylphosphatidylcholine were studied using DSC. It was shown that while both drugs can interact with model membranes, the mechanisms of such interactions for decamethoxinum and aethonium differ. The correlation between the nature of these interactions and structural and electronic parameters of the dications of the two bisquaternary agents is discussed. Interpretation of combined mass spectrometric and calorimetric experimental data led to proposals that the molecular mechanisms of antimicrobial action of bisquaternary ammonium compounds are related to their effect on the membrane phospholipid components of microbial cells. Copyright © 2002 John Wiley & Sons, Ltd.
Goodness‐of‐fit processes for logistic regression: simulation results
Authors: Hosmer David W. , Hjort Nils Lid
Published: October 2002

In this paper we use simulations to compare the performance of new goodness‐of‐fit tests based on weighted statistical processes to three currently available tests: the Hosmer–Lemeshow decile‐of‐risk test; the Pearson chi‐square, and the unweighted sum‐of‐squares tests. The simulations demonstrate that all tests have the correct size. The power for all tests to detect lack‐of‐fit due to an omitted quadratic term with a sample of size 100 is close to or exceeds 50 per cent to detect moderate departures from linearity and is over 90 per cent for these same alternatives for sample size 500. All tests have low power with sample size 100 to detect lack‐of‐fit due to an omitted interaction between a dichotomous and continuous covariate, while the power exceeds 80 per cent to detect extreme interaction with a sample size of 500. The power is low to detect any alternative link function with sample size 100 and for most alternative links for sample size 500. Only in the case of sample size 500 and an extremely asymmetric link function is the power over 80 per cent. The results from these simulations show that no single test, new or current, performs best in detecting lack‐of‐fit due to an omitted covariate or incorrect link function. However, one of the new weighted tests has power comparable to other tests in all settings simulated and had the highest power in the difficult case of an omitted interaction term. We illustrate the tests within the context of a model for factors associated with abstinence from drug use in a randomized trial of residential treatment programmes. We conclude the paper with a summary and specific recommendations for practice. Copyright © 2002 John Wiley & Sons, Ltd.
Native states of adenylate kinase are two active sub‐ensembles
Authors: Han Yang , Li Xia , Pan Xianming
Published: October 2002

There are two kinds of conformational forms of adenylate kinase (AK) in equilibrium in solution with different ANS‐binding properties. Furthermore, the nature of AP5A inhibition suggests also that the native forms of AK for binding with different substrates pre‐exist in the absence of substrates. In the present study, a kinetics approach was used to explore the native forms distinguished by ANS‐binding properties and by the nature of AP5A inhibition. The results revealed that the native forms distinguished by ANS probe are two conformational sub‐ensembles. Both sub‐ensembles are active and consist of a series of forms, which pre‐exist in solution and can bind with different substrates. The K
m values of N1 for AMP, ADP and MgATP are larger than that of N2, indicating that the N2 sub‐ensemble is more specific for binding substrates. This is consistent with the previous observation that the activity of N2 is about 1.8‐fold of that of N1.
Spectroscopic characterisation of a tetrameric subunit form of the core antenna protein from Rhodospirillum rubrum
Authors: Végh Attila P , Robert Bruno
Published: October 2002

The core light‐harvesting complex (LH1) of Rhodospirillum rubrum is constituted of multiple heterodimeric subunits, each containing two transmembrane polypeptides, α and β. The detergent octylglucoside induces the stepwise dissociation of LH1 into B820 (an αβ dimer) and B777 (monomeric polypeptides), both of which still retain their bound bacteriochlorophyll molecules. We have investigated the absorption properties of B820 as a function of temperature, whereby a spectral population called ‘B851’ has been characterised. We show evidence that it is a dimer of the B820 complex. This may represent an intermediate oligomeric form in the process of the LH1 ring formation, as its existence was predicted from global analysis of the absorption spectra of the LH1/B820 equilibrium [Pandit et al. (2001) Biochemistry 40, 12913–12924]. Stabilisation of this dissociated form of LH1 may help in understanding both the electronic properties and the association process of these integral membrane proteins.
Fluorescence of native and carotenoid‐depleted LH2 from Chromatium minutissimum, originating from simultaneous two‐photon absorption in the spectral range of the presumed (optically ‘dark’) S1 state of carotenoids
Authors: Krikunova M , Kummrow A , Voigt B , Rini M , Lokstein H , Moskalenko A , Scheer H , Razjivin A , Leupold D
Published: October 2002

Native and carotenoid‐depleted peripheral purple bacterial light‐harvesting complex (LH2) were investigated by simultaneous two‐photon excited (between 1300–1500 nm) fluorescence (TPF). TPF results from direct bacteriochlorophyll excitation in both samples. The spectral position of the 2Ag
− state of rhodopsin is indicated by a diminuition of the bacteriochlorophyll TPF in native LH2. In conclusion, comparison to carotenoid‐depleted samples is a conditio sine qua non for unambiguous interpretation of similar experiments.
Effect of cholesterol on the interaction of seminal plasma protein, PDC‐109 with phosphatidylcholine membranes
Authors: Swamy Musti J , Marsh D , Anbazhagan V , Ramakrishnan M
Published: October 2002

Binding of PDC‐109, the major protein of the bovine seminal plasma, to sperm plasma membrane results in an efflux of cholesterol and choline phospholipids, a necessary event before capacitation can occur. The selectivity of PDC‐109 for different spin‐labelled phospholipids and sterol probes in dimyristoylphosphatidylcholine (DMPC) host matrix has been characterized earlier by EPR spectroscopy [Ramakrishnan, M., Anbazhagan, V., Pratap, T.V., Marsh, D. and Swamy, M.J. (2001) Biophys. J. 81, 2215–2225]. In this report the effect of cholesterol on the interaction of PDC‐109 with DMPC membranes has been investigated by spin‐label EPR spectroscopy. The results indicate that the presence of cholesterol leads to an increased association of different phospholipid as well as sterol probes, thus modulating the interaction of PDC‐109 with phospholipid membranes.
Value creation through enriched marketing–operations interfaces: an empirical study in the printed circuit board industry
Authors: Sawhney Rajeev , Piper Chris
Published: October 2002

The paper examines the short‐term capacity interface between marketing and operations, i.e. marketing–operations interface (MOI) in relation to customer value. A field study involving 10 firms in the printed circuit board (PCB) manufacturing industry was used to develop a conceptual framework and measures of the constructs. Subsequently, a 180‐plant PCB industry survey was used to test the model, finding support for the proposed relationship between MOI effectiveness and customer value.
On the support of solutions to the generalized KdV equation
Authors: Vega Luis , Kenig Carlos E. , Ponce Gustavo
Published: October 2002

It is shown that if

u

is a solution of the initial value problem for the generalized Korteweg–de Vries equation such that there exists

b \in ℝ

with

\text{supp}u\left(.,t_{j}\right) \subseteq \left(b,\infty \right)

(or

(−∞,b)

), for

j*=1,2

(

t_1≠t_2), then

u≡0$.

On montre que si

u

est une solution du problème de Cauchy pour l'équation généralise de Korteweg–de Vries et

b \in ℝ

tel que

\text{supp}u\left(.,t_{j}\right) \subseteq \left(b,\infty \right)

(ou

(−∞,b)

), pour

j=1,2

(

t_1≠t_2

), alors

u

est nulle.
A functional analysis approach to Arnold diffusion
Authors: Berti Massimiliano , Bolle Philippe
Published: October 2002

We discuss in the context of nearly integrable Hamiltonian systems a functional analysis approach to the “splitting of separatrices” and to the “shadowing problem”. As an application we apply our method to the problem of Arnold Diffusion for nearly integrable partially isochronous systems improving known results.

Nous discutons dans le contexte des systèmes hamiltoniens presque intégrables une approche basée sur l'analyse fonctionnelle des problèmes de “splitting” des séparatrices et de “shadowing”. Nous appliquons notre méthode au problème de la diffusion d'Arnold pour des systèmes presque intégrables partiellement isochrones, améliorant des résultats connus.
Correctors and error estimates in the homogenization of a Mullins–Sekerka problem
Authors: Garroni Adriana , Niethammer Barbara
Published: October 2002

We study the homogenization of a Mullins–Sekerka free boundary problem which serves as a model for coarsening of nuclei in a first order phase transformation. We consider a regime where the volume fraction of the nuclei is small but screening effects are not negligible. The limit equation was recently derived in [12]. We improve this convergence result by constructing correctors and providing error estimates in terms of the volume fraction. This yields in particular an asymptotic expansion for the growth rate of the nuclei.

On étudie l'homogénéisation d'un problème de frontiere libre de Mullins–Sekerka, qui sert de modèle pour le “coarsening” des noyaux dans une transformation de phase du premièr ordre. On considére un régime où la fraction de volume des noyaux est petite mais où les effets de criblage ne sont pas négligeables. L'équation limite a récemment été dérivée dans [12]. Nous améliorons ce résultat de convergence en construisant des correcteurs et fournissant des evaluations d'erreur en termes de la fraction de volume. Ceci conduit en particulier á une expansion asymptotique pour le taux de croissance des noyaux.
5-HT2A gene promoter polymorphism as a modifying rather than a vulnerability factor in anorexia nervosa
Authors: Kipman A. , Bruins-Slot L. , Boni C. , Hanoun N. , Adès J. , Blot P. , Hamon M. , Mouren-Siméoni M.-C. , Gorwood P.
Published: October 2002

The A allele of the 5-HT2A gene (–1438A/G polymorphism) has been associated with anorexia nervosa in four studies, but not in three others. One possibility to explain such a discrepancy is that the A allele acts as a modifying rather than a vulnerability allele. To test this hypothesis, we increased our initial sample of 102 trios [Mol. Psychiatry 7 (2002) 90] with 43 new patients with anorexia nervosa and 98 healthy controls. In addition to confirming the absence of association on the global sample of 145 patients, we found that patients with the A allele had a significantly later age at onset of the disease (P = 0.032). Furthermore, the A allele was also transmitted with an older age at onset (P = 0.023) using a quantitative-trait TDT approach. The A allele may thus act as a modifying factor (delaying onset), potentially explaining variations of allele frequency across samples, in which differences in average age at onset are not only possible, but also expected. Taking into account vulnerability genes, but also genes modifying the expression of the disorder, will help to disentangle the complexity of the etiological factors involved in anorexia nervosa.
Efficacy of lithium treatment in Kleine–Levin syndrome
Authors: Muratori F. , Bertini N. , Masi G.
Published: October 2002

The Kleine–Levin syndrome (KLS) is characterized by periodic, sudden-onset episodes of hypersomnia, compulsive hyperphagia, and behavioral–emotional symptoms, lasting from a few days to a few weeks, with complete remission in the intercritical periods. We report on efficacy of lithium treatment in a highly recurring form of the disorder in a 17-year-old male adolescent. The decreasing severity of the disorder paralleled the progressive increase of lithium dosage, up to 0.9 mEq l–1. Implications regarding the pharmacological treatment of this neglected disorder are discussed.
Shareholder Wealth Effects of CalPERS' Activism
Authors: Crutehley Claire E. , Hudson Carl D. , Jensen Marlin R.H.
Published: October 2002

In the past decade, institutional investors have become more active in monitoring man- agement and voting the shares they control. The California Public Employees' Retirement System (CaIPERS) was a leader in this wave of activism. This study investi- gates the long-term returns an investor with public information could earn by buying a portfolio offirms targeted by CaIPERS and whether the success of CaIPERS' activism depends on the aggressiveness of the targeting. The evidence supports the idea that vis- ible and aggressive activism leads to substantial increases in shareholder wealth while a quieter activism does not.
Participation in higher education
Authors: Lauer Charlotte
Published: October 2002

This study applies to German data a model in which the decision to attend higher education depends on the ratio of marginal cost and marginal return expected from higher education. If this ratio is below a certain threshold, the individual will choose to participate in higher education. In a simulation exercise, the impact of selected variables on this threshold, and thus on the participation probability, is quantified. The results suggests the presence of financial constraints binding participation in higher education and that the participation decision responds to some extent to return expectations in terms of labour market outcome and to financial incentives such as student support.
Technical/professional versus general education, labor market networks and labor market outcomes
Authors: Margolis David N. , Simonnet Véronique
Published: October 2002

Does the choice between a general and a technical/professional education determine the quality of the labor market network that an individual will be able to exploit throughout his or her professional life? This paper examines the hypothesis that technical and professional tracks, because they involve fewer students who are in more regular contact with each other and focus on a common, relatively narrow subject, allow students to establish more effective networks to support them in their careers. We test whether the choice of educational track has an impact on the means by which jobs are obtained and on the time to the first job of at least six months, the percentage of time spent in employment later in the career and the earnings when employed later in the career in France. Our results suggest that the educational track determines the means of obtaining a job, but conditional on the manner in which the job was obtained, the track has no additional impact on the outcome variables for the first or later jobs. However, the link between technical/professional education and job obtainment via professional networks does not hold independent of the level of education. In particular, this effect seems pertinent only for students having obtained a professional or technical baccalauréat (relative to a general baccalauréat) or for students having obtained a degree from a “grande école” or engineering school (relative to graduate‐level university studies).
The dynamics of knowledge flows: human capital mobility, knowledge retention and change
Authors: Madsen Tammy L. , Mosakowski Elaine , Zaheer Srilata
Published: October 2002

This empirical paper investigates the relationships between the amount of human capital that flows into a firm and two activities underlying a firm’s knowledge production, variation or change and knowledge retention. We track the flow of human capital within and across organizational and geographic space for all multi‐unit banks operating in the world foreign exchange trade industry from 1973 to 1993. The findings indicate that an increased reliance on past experience reduces how much human capital a firm imports in the future. This effect is moderated by a self‐reinforcing cycle of human capital inflow. Inflows of human capital also decline when a firm has recently adopted novel changes in its operations. The paper uses evolutionary thinking to define a model for intrafirm knowledge production.
DAILY VARIATION IN COSMIC RAY INTENSITY ON DIFFERENT GEOMAGNETIC CONDITIONS
Authors: KUMAR SANTOSH , AGARWAL REKHA , MISHRA RAJESH , DUBEY S. K.
Published: October 2002

A new concept of data analysis has been attempted for studying the long/short term daily variations in cosmic ray (CR) intensity recorded with neutron monitors/meson telescopes. Fourier Technique has been applied on four different types of groups of days chosen according to their different geomagnetic conditions. The selected groups are 60 quietest days (60 QD), 120 quiet days (120 QD), continuous quiet days (CQD) and All Days (AD) in a year. CQD is a new set of days selected on the basis of Ap and Kp values. These are the days when transient magnetic variations are supposed to be regular and smooth continuously for a span of at least three days. The criteria of selection of CQD is based upon the mathematical manipulation with Ap index. The data of Deep River neutron monitoring station is used for the period 1985–1995, to investigate for a com-parative study of diurnal anisotropy in CR intensity on 60 QD, 120 QD, CQD and AD. It is observed that 60 QD are most suitable for the anisotropic studies on short/long term basis. The time/spatial variations in the amplitude and phase of the diurnal anisotropy become more pronounced for 60 QD for the period under investigation.