bluuebunny/crossref_metadata_2025_split huggingface dataset:
An adaptive displacement/pressure finite element scheme for treating incompressibility effects in elasto‐plastic materials
Authors: Suttmeier Franz–Theo 
Published: August 2002

AbstractIn this article, a mixed finite element formulation is described for coping with (nearly) incompressible behavior in elasto‐plastic problems. In addition to the displacements, an auxiliary variable, playing the role of a pressure, is introduced resulting in Stokes‐like problems. The discretization is done by a stabilized conforming Q1/Q1‐element, and the corresponding algebraic systems are solved by an adaptive multigrid scheme using a smoother of block Gauss–Seidel type. The adaptive algorithm is based on the general concept of using duality arguments to obtain weighted a posteriori error bounds. This procedure is carried out here for the described discretization of elasto‐plastic problems. Efficiency and reliability of the proposed adaptive method is demonstrated at (plane strain) model problems. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17:369–382, 2001
An optimal‐order error estimate for MMOC and MMOCAA schemes for multidimensional advection‐reaction equations
Authors: Wang Hong 
Published: August 2002

AbstractIn this article, we analyze the modified method of characteristics (MMOC) and an improved version of the MMOC, named the modified method of characteristics with adjusted advection (MMOCAA), for multidimensional advection‐reaction transport equations in a uniform manner. We derive an optimal‐order error estimate for these schemes. Numerical results are presented to verify the theoretical estimates. © 2002 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 18: 69–84, 2002
Clinical trials in the 21st century: The case for participant‐centered research¶
Authors: Gross Deborah , Fogg Louis 
Published: August 2002

AbstractInformed consumers of the 21st century increasingly will be hesitant to enroll in randomized clinical trials (RCTs) because they will be unwilling to (a) submit to random assignment; (b) complete assessments that are too lengthy, intrusive, or irrelevant; or (c) comply with protocols that do not meet their needs. Research centered on the needs and interests of participants is likely to engender greater participation and commitment than are traditional RCTs. Recommendations for making clinical trials more participant centered include: (a) expanding our conceptualizations of study validity, (b) involving consumers as advisers in the development and execution of clinical trials, and (c) offering participants reasonable alternatives to random assignment. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:530–539, 2001
Occipital perforations in a late neolithic probable aurochs (Bos primigenius bojanus) cranium from Letchworth, Hertfordshire, UK
Authors: Baxter Ian L. 
Published: August 2002

AbstractAn example of ante‐mortem occipital perforations in the cranium of a probable aurochs (Bos primigenius) cow from a late Neolithic archaeological site at Letchworth, Hertfordshire is presented. This is the second reported occurrence thus far of cranial perforations in a wild bovid and lends support to a congenital cause of the condition in archaeological domestic cattle skulls. Copyright © 2002 John Wiley & Sons, Ltd.
The role of cetacea in prehistoric and historic Atlantic Scotland
Authors: Mulville Jacqui 
Published: August 2002

AbstractWhalebone has been recovered from many archaeological sites in Atlantic Scotland. Through an examination of material excavated from the Western Isles (Outer Hebrides) this paper explores the methods by which whales and whalebone were procured. Using historical and ethnographic data the possibility that cetaceans were naturally stranded or actively hunted is considered, and for the latter the methods of capture are discussed. The ways in which whale carcasses were utilized: as meat, blubber, skins, artefacts and as an architectural material, is examined through the analysis of archaeozoological material. Using these data the value of whales and whale bone in the islands can be determined. The potential for further study is discussed in the light of the growing volume of material available for study and advances in scientific techniques such as DNA analysis. Copyright © 2002 John Wiley & Sons, Ltd.
Unified approach to linear quadratic regulator with time‐scale property
Authors: Singh Hardev , Brown Ronald H. , Subbaram Naidu D. 
Published: August 2002

AbstractA method for decomposition of unified (continuous/discrete) linear quadratic regulator with two‐time‐scale property is presented. The composite and the reduced‐order controls are formulated in standard unified domain. By appropriate transformations, it is shown that the results of continuous‐time (CT) and discrete‐ time (DT) obtained previously using two separate techniques, can be obtained by this single unified technique. With this method, there is no need to consider two‐time scale systems in continuous and the discrete domains separately. This paper also presents some numerical examples to illustrate the theoretical results. Copyright © 2001 John Wiley & Sons, Ltd.
Optimal weighting design for distributed parameter systems estimation
Authors: Ouarit Mostafa , Yvon Jean‐Pierre , Henry Jacques 
Published: August 2002

AbstractThis paper presents a method which aims at improving parameter estimation in dynamical systems. The general principle of the method is based on a modification of the least‐squares objective function by means of a weighting operator, in view to improve the conditioning of the identification problem. First we recall a previous work using variational calculus in order to obtain the weighting operators through a linear equation. Then we propose a new approach which consists of determining the weights by formulating an optimization problem including positive semidefinite constraints (linear matrix inequalities, LMI). Copyright © 2001 John Wiley & Sons, Ltd.
Restricted structure control of multiple model systems with Series 2 DOF tracking and feedforward action
Authors: Grimble M. J. 
Published: August 2002

AbstractThe solution of a scalar optimal control problem is discussed where the feedback, series tracking and feedforward controllers are chosen to have a very simple. Each controller term may be chosen to be of reduced order, lead/lag, or PID forms, and the controller is required to minimize an LQG cost‐index. The optimization is based upon a cost‐function which also allows separate costing of the terms due to the feedback, tracking and feedforward controllers. The system model can be uncertain and can be represented by a set of models over which the optimization is performed. This provides a form of robust optimal control that might even be applied to non‐linear systems that can be approximated by a set of linearized models.The theoretical problem considered is to obtain the causal, stabilizing, feedback, series‐tracking and feedforward controllers, of a prespecified form, that minimize an LQG criterion over the set of possible linear plant models. The underlying practical problem of importance is to obtain a simple method of tuning low‐order controllers, given only an approximate model of the process. The results are illustrated in a power generation control problem for a system represented by 12 different linearized plant models. The single feedback controller that is obtained has a simple form and stabilizes the full set of models. Copyright © 2001 John Wiley & Sons, Ltd.
Seeing eye to eye: organizational behaviour, brokering and building trust in Tanzania
Authors: Hewitt Tom , Wangwe Sam , Wield David 
Published: August 2002

AbstractThe focus of this article is organizational behaviour in and around the private sector in Tanzania at a time of transition through liberalization and the promotion of private sector activity; how the private sector has re‐emerged in the very recent past; how it operates as a group or, more accurately, as a set of groups, and the relationships between its component parts and with other development organizations (notably public actors: the state and aid donors). Within this framework our interest is in how organizational behaviour is mediated and trust is built through the brokering of relations between different organizations which intersect the public and private (and what this means for the public sphere). The article assesses the usefulness of a three‐level framework for analysing organizational and institutional transformation, shows that some tentative but modest change is occurring, and that a range of incomplete but positive political processes are happening. We show that institutional development is the weak link in these processes. Copyright © 2002 John Wiley & Sons, Ltd.
School vouchers and academic performance: results from three randomized field trials
Authors: Howell William G. , Wolf Patrick J. , Campbell David E. , Peterson Paul E. 
Published: August 2002

AbstractThis article examines the effects of school vouchers on student test scores in New York, New York, Dayton,
Ohio, and Washington, DC. The evaluations in all three cities are designed as randomized field trials. The
findings, therefore, are not confounded by the self‐selection problems that pervade most observational
data. After 2 years, African Americans who switched from public to private school gained, relative to their
public‐school peers, an average of 6.3 National Percentile Ranking points in the three cities on the Iowa
Test of Basic Skills. The gains by city were 4.2 points in New York, 6.5 points in Dayton, and 9.2 points in
Washington. Effects for African Americans are statistically significant in all three cities. In no city are
statistically significant effects observed for other ethnic groups, after either 1 or 2 years. © 2002 by
the Association for Policy Analysis and Management.
Synthesis and magnetic properties of poly(p‐phthaloyl‐disacetylaceton‐ethylenediimine) metal complexes
Authors: Wang Yun‐Pu , Chai Chun‐Peng , Wang Rong‐Min 
Published: August 2002

AbstractMacrocyclic Schiff‐base ligand, bisacetylaceton‐ethylenediimine (BAE) and its transition metal complexes M(BAE) (M = Cu2+, Ni2+) were synthesized. The complexes having characteristics of aromatic systems and well‐defined one‐dimensional structures, reacted with p‐phthaloyl chloride, to obtain polymer complexes. The complexes were characterized by elemental analysis, inductively coupled plasma (ICP), FT‐IR, and thermal analysis and show good thermal stability. ESR spectra analysis discovered that there are free radicals in the chain of polymers, indicating that a weak magnetic spin‐exchange interaction operates between the metal ions and free radicals. It is found that, as the bridging p‐phthaloyl group is able to propagate the magnetic exchange interaction, the polymer complexes show paramagnetic properties by measurement of temperature dependence of the magnetic property, and obey Curie–Weiss law. Copyright © 2001 John Wiley & Sons, Ltd.
Monodispersed polystyrene latex particles functionalized by the macromonomer technique. II. Application in immunodiagnosis
Authors: Gibanel Sebastien , Heroguez Valerie , Gnanou Yves , Aramendia Esteban , Bucsi Alexander , Forcada Jacqueline 
Published: August 2002

AbstractMonodispersed polymer colloids with aldehyde and acetal functionalities, introduced by the macromonomer technique, were synthesized by a two‐step emulsion polymerization process. The latex samples so formed were chosen as the polymeric support to carry out covalent coupling with the antibody IgG anti‐C reactive protein, to test the utility of the latex–protein complexes formed in immunoassays. More than the 45% of the initially linked protein was covalently coupled in the acetal latex samples. Copyright © 2001 John Wiley & Sons, Ltd.
Controlled, micro‐scale film formation of waterborne dispersions
Authors: Krupers Maarten J. , Fischer Hartmut R. , Schuurman Arjan G.A. , Vercauteren Frank F. 
Published: August 2002

AbstractThe film formation on a micro‐scale of latex material is described. Waterborne polymer dispersions dried below their Tg are treated by laser or direct heat treatment by means of a tip (diameter 5 µ m) of a micro thermal analysis apparatus (µ ‐TA). Both methods give a linewidth, line thickness and dot‐sizes in the micron range. The layer thickness decreases during fusion of the particles because of the loss of voids during film formation. Non treated areas can be washed away selectively. Laser treatment gives a more smooth surface than direct thermal treatment with a µ‐TA tip. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of fuel cell performance of selected fluoropolymer and hydrocarbon based grafted copolymers incorporating acrylic acid and styrene sulfonic acid
Authors: Horsfall J. A. , Lovell K. V. 
Published: August 2002

AbstractFuel cell tests have been carried out on ion exchange membranes produced by the radiation grafting of either acrylic acid or styrene monomers (followed by a sulphonation reaction) onto selected hydrocarbon and fluoropolymer films. Relationships between the membranes' intrinsic properties, composition, ion exchange capacity and equilibrium water content and their respective fuel cell performance have been established. Copyright © 2002 John Wiley & Sons, Ltd.
Charge carrier transport in poly[methyl(phenyl)silylene]: the effect of additives
Authors: Nešpůrek S. , Valerián H. , Eckhardt A. , Herden V. , Schnabel W. 
Published: August 2002

AbstractPoly[methyl(phenyl)silylene], PMPSi, was doped with compounds of the electron acceptor type. The charge carrier mobility increases with increasing electron affinity of the acceptors having zero dipole moments. At the same time the energy distribution of hopping states narrows. On the other hand, the hole drift mobility is influenced by the dipole moment of the dopand. The electrostatic charge carrier‐dipole interaction causes a broadening of the energy distribution of transport states which results in a decrease in the charge carrier mobility. The charge carrier transport can be explained by the disordered polaronic theory, according to which the activation energy of charge carrier mobility has contributions based on the dynamic disorder, i.e. the polaronic barrier, and on the static disorder, i.e. the variation of the energy of transport states as a result of the environment. Copyright © 2001 John Wiley & Sons, Ltd.
Direct analysis of single leaf disks for chemopreventive glucosinolates
Authors: Wang Qiaomei , Grubb C. Douglas , Abel Steffen 
Published: August 2002

AbstractNatural isothiocyanates, produced during plant tissue damage from methionine‐derived glucosinolates, are potent inducers of mammalian phase 2 detoxification enzymes such as quinone reductase (QR). A greatly simplified bioassay for glucosinolates based on induction and colorimetric detection of QR activity in murine hepatoma cells is described. It is demonstrated that excised leaf disks of Arabidopsis thaliana (ecotype Columbia) can directly and reproducibly substitute for cell‐free leaf extracts as inducers of murine QR, which reduces sample preparation to a minimum and maximizes throughput. A comparison of 1 and 3 mm diameter leaf disks indicated that QR inducer potency was proportional to disk circumference (extent of tissue damage) rather than to area. When compared to the QR inducer potency of the corresponding amount of extract, 1 mm leaf disks were equally effective, whereas 3 mm disks were 70% as potent. The QR inducer potency of leaf disks correlated positively with the content of methionine‐derived glucosinolates, as shown by the analysis of wild‐type plants and mutant lines with lower or higher glucosinolate content. Thus, the microtitre plate‐based assay of single leaf disks provides a robust and inexpensive visual method for rapidly screening large numbers of plants in mapping populations or mutant collections and may be applicable to other glucosinolate‐producing species. Copyright © 2002 John Wiley & Sons, Ltd.
Second‐trimester maternal serum alpha‐fetoprotein (MSAFP) iselevated in women with adverse pregnancy outcome associated with inherited thrombophilias
Authors: Ochshorn Yifat , Kupferminc Michael J. , Eldor Amiram , Wolman Igal , Lessing Joseph B. , Yaron Yuval 
Published: August 2002

AbstractObstetric complications, such as severe pre‐eclampsia, fetal growth restriction, abruptio placentae, or stillbirth are associated with abnormally elevated second‐trimester maternal serum alpha‐fetoprotein (MSAFP) and β subunit of human chorionic gonadotrophin (βhCG). This has been attributed to placental abnormalities. Women with thrombophilias have been shown to have abnormalities of the placenta resulting in adverse pregnancy outcome in these patients. The purpose of the present study was to evaluate whether women with pregnancy complications and inherited thrombophilias have abnormally elevated second‐trimester MSAFP or βhCG. Sixty‐two women with pregnancy complications were tested for inherited thrombophilias several months after delivery. The thrombophilia group included 29 women with pregnancy complications and an inherited thrombophilia and the control group included 33 other patients without thrombophilia. Patients in the thrombophilia group had a higher median MoM MSAFP compared to the controls (1.337 vs 1.086, p=0.0516). The incidence of abnormally elevated MSAFP (>2.5 MoM) was also significantly higher in the thrombophilia group compared to controls (21% vs 3%, p=0.04). Neither the median MoM βhCG nor the incidence of abnormally elevated βhCG were significantly different between the groups. We conclude that second trimester MSAFP, but not βhCG, is abnormally elevated in patients with thrombophilia and obstetric complications. Copyright © 2001 John Wiley & Sons, Ltd.
Measurement of inhibin A: a modification to an enzyme‐linked immunosorbent assay
Authors: Thirunavukarasu Prema P. , Wallace Euan M. 
Published: August 2002

AbstractInhibin A is a useful prenatal marker of Down syndrome. Currently, the available enzyme‐linked immunosorbent assays (ELISAs) for inhibin A are based upon the same paired monoclonal antibodies. In the present study we have confirmed for one of those ELISAs that short‐term sample storage as whole blood leads to a significant decline in detectable inhibin A and that this is most likely due to erythrocyte catalase interference with a critical oxidation step in the assay. While this interference can be eliminated by heating the samples pre‐assay, this process is labour intensive. In the present study we have demonstrated that the addition of 3‐amino‐1,2,4‐triazole (AT), a catalase ‘suicide’ inhibitor, also prevents the decline of inhibin A levels in samples stored as whole blood. We suggest that the addition of AT to samples prior to assay is a simple modification to the inhibin A ELISA that affords optimum performance. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal diagnosis of ATR‐X syndrome in a fetus with a new G>T splicing mutation in the XNP/ATR‐X gene
Authors: Fichera Marco , Silengo Margherita , Spalletta Angela , Lo Giudice Mariangela , Romano Corrado , Ragusa Angela 
Published: August 2002

AbstractThe molecular cause of the α‐thalassemia/mental retardation syndrome (ATR‐X) resides in mutations affecting the XNP/ATR‐X gene. Recently molecular defects in the gene have been found in singular cases of a discrete number of X‐linked mental retardation (XLMR). ATR‐X‐affected males are characterised by severe mental retardation, distinct facial dysmorphisms and genital abnormalities, besides a wide spectrum of pathological features and an extremely limited biological fitness. Given that molecular investigation of XNP/ATR‐X mutations is made onerous by the length of the gene transcript, we carried out a prenatal diagnosis in a fetus at risk for ATR‐X syndrome by initially determining the XNP/ATR‐X gene haplotype before considering gene sequencing. Disease‐associated haplotype analysis was performed selecting five genic (CA)n repeats that showed high heterozygosity (Het>0.7) in the general population. The fetus segregated an identical allelic pattern to that of the affected child of the family under investigation who shows features suggestive of the ATR‐X syndrome. Subsequent mutational analysis of the gene revealed a novel IVS3+1G>T splicing mutation confirming the diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.
Karyotype, phenotype and parental origin in 19 cases of triploidy
Authors: Daniel Art , Wu Zhanhe , Bennetts Bruce , Slater Howard , Osborn Robert , Jackson Julianne , Pupko Vladimir , Nelson John , Watson Geoff , Cooke‐Yarborough Claire , Loo Christine 
Published: August 2002

AbstractThe parental origin of triploidy in 19 cases was examined by inheritance of DNA microsatellites and by methylation patterns of SNRPN or PW71 (where parents' blood was unavailable). The fetal and placental morphology on these cases was reviewed. The phenotype of the fetuses with non‐mosaic triploidy was assessed in relation to the two types described by McFadden and Kalousek. Of the diandric fetuses three of the six showed mild‐to‐moderate symmetrical growth retardation and the other three had growth characteristics in accordance with their gestational ages. This study would suggest the fetal triploid ‘Type 1’ definition be modified to ‘well grown to moderate symmetrical IUGR’ to allow for such variation. In the digynic fetuses (McFadden/Kalousek Type 2) there were poor growth characteristics with IUGR being more severe and asymmetrical. The diandric fetuses were as common as digynic fetuses in this series. The ratio of diandric to digynic specimens was 11:8 but if only fetal specimens (not embryos or mosaic children) were included the ratio was 6:5. Many diandric conceptions end as partial moles but later in gestation diandric fetuses may be well grown. It is proposed that there may be a survival barrier for diandric fetuses early in gestation (possibly based on the proportion of vascularised placental villi), although once this is passed the diandric fetuses are comparatively more viable and better grown than digynic fetuses. In the XXY triploid fetuses, 5/6 had hypoplastic or ambiguous external genitalia (two were recorded as of female phenotype) as has been reported previously. In these, the gonadal histology was testicular in all the diandrics but in the single digynic XXY case, sex reversal was complete with normal uterus and Fallopian tubes and the gonads were histologically ovaries. Two triploid/diploid mosaics were proven to be due to digyny. The probable cause is delayed incorporation of the second polar body into a blastomere and there was evidence of identical alleles from the same sperm being present in both diploid and triploid cells. In one of these triploid/diploid mosaics in which there was a termination of pregnancy (TOP) after prenatal karyotyping the diploid cell line had trisomy 16 which was not evident in the triploid line. This trisomy was probably of post‐zygotic origin and we suggest the fetus was rescued by the prominence of the triploid line. Copyright © 2001 John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis of pericentric inversions
Authors: Escudero Tomás , Lee Michael , Stevens John , Sandalinas Mireia , Munné Santiago 
Published: August 2002

AbstractInversions are structural chromosome abnormalities that may be associated with infertility, multiple miscarriage and chromosomally unbalanced offspring. Preimplantation genetic diagnosis (PGD) with subtelomeric probes was used to select for transfer only those embryos that were normal or balanced for three pericentric inversions. In contrast to previous protocols the present procedure allows the detection of unbalanced embryos that might arise from U‐recombination in the inverted region. Additionally, aneuploidy screening was carried out in two cases by a second round of fluorescent in situ hybridization (FISH) with centromeric probes. Of the three couples that underwent the procedure one became pregnant twice. The first pregnancy delivered a healthy and chromosomally normal baby and the second pregnancy is ongoing with triplets. Copyright © 2001 John Wiley & Sons, Ltd.