bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of hydatid cyst from cysticercus cyst by proton MR spectroscopy
Authors: Garg Monika , Chawla Sanjeev , Prasad Kashi N. , Roy Raja , Sikora Sadiq S. , Kumar Rajesh , Husain Mazhar , Khetrapal C. L. , Gupta Rakesh K.
Published: August 2002

The metabolite patterns obtained by ex vivo proton MR spectroscopy of fluid from different locations of hydatid cysts of sheep and humans (n = 16) and cysticercus cysts of swine and humans (n = 25) were compared with an objective of differentiating the two parasites on the basis of their metabolite pattern. The spectra from hydatid fluid differed from cysticercus cyst by the absence of creatine in the former. When the hydatid cyst was fertile, malate and/or fumarate was also observed, which was absent in cysticercus cyst. The most likely explanation for the presence of creatine only in the cysticercus fluid is its active diffusion from the surrounding host tissue along with a contribution from the musculature present in the bladder wall of the cyst. Copyright © 2002 John Wiley & Sons, Ltd.
In vivo brain 31P‐MRS: measuring the phospholipid resonances at 4 Tesla from small voxels
Authors: Jensen J. Eric , Drost Dick J. , Menon Ravi S. , Williamson Peter C.
Published: August 2002

An optimized phosphorous (31P) three‐dimensional chemical‐shift imaging (3D‐CSI) protocol was developed at 4 T to study the phospholipid metabolism from discrete regions in the human brain without the need for 1H‐decoupling or nuclear Overhauser enhancement (NOE). In this study, a spherically bound, weighted average, random point omission 3D‐CSI technique was developed and tested, based on methods proposed in the literature. The technique yields a significant (p < 0.001, two‐tailed, 5% confidence level) increase in signal‐to‐noise (SNR) efficiency over conventional 3D‐CSI (phantom 32%), without an increase in voxel bleedthrough. An automated time‐domain fitting procedure utilizing prior spectral knowledge quantified the individual brain phospholipid metabolites from 15 cm3 effective (8.0 cm3 nominal) volumes from the left/right‐parieto‐occipital cortex and left/right thalamus in 10 normal volunteers. Individual constituents from the phosphomonoester (PME) region; phosphoethanolamine (PEth), phosphocholine (PCh) and the phosphodiester (PDE) region; glycerophosphoethanolamine (GPEth), glycerophosphocholine (GPCh) and membrane phospholipids (MP) were separately quantified to assess the precision of our method at 4 T against previous 1H‐decoupled 31P‐MRS brain studies at lower fields and much larger voxels. Derived concentrations (mM/l tissue) for PEth, PCh, GPEth, GPCh and MP in the left‐parieto‐occipital cortex were 0.81 ± 0.21, 0.46 ± 0.14, 0.74 ± 0.30, 1.15 ± 0.43 and 1.54 ± 0.95 mM, respectively, and 0.94 ± 0.16, 0.46 ± 0.17, 0.83 ± 0.22, 1.14 ± 0.40 and 1.26 ± 0.78 mM for the right parieto‐occipital cortex. Derived concentrations (mM/l tissue) for PEth, PCh, GPEth, GPCh and MP in the left‐thalamus were 0.69 ± 0.18, 0.42 ± 0.16, 0.63 ± 0.20, 1.05 ± 0.42 and 0.93 ± 0.56 mM, respectively, and 0.68 ± 0.24, 0.34 ± 0.18, 0.60 ± 0.23, 1.09 ± 0.36 and 0.74 ± 0.48 mM for the right‐thalamus. This is the first study to our knowledge that has been able to quantify each of these individual phospholipid metabolites from such small voxels in the brain within a clinically reasonable scan time and without 1H‐decoupling or NOE. Copyright © 2002 John Wiley & Sons, Ltd.
Changes in phosphate metabolism in thymoma cells suggest mechanisms for resistance to dexamethasone‐induced apoptosis. A 31P NMR spectroscopic study of cell extracts
Authors: Lutz N. W. , Tome M. E. , Aiken N. R. , Briehl M. M.
Published: August 2002

Treatment of the mouse thymoma‐derived WEHI7.2 cell line with dexamethasone, a synthetic glucocorticoid, causes the cells to undergo apoptosis. Previous studies have shown that WEHI7.2 cell variants with an increased antioxidant defense exhibit increased resistance to dexamethasone‐induced apoptosis, suggesting that oxidative stress may play a role in glucocorticoid‐induced apoptosis. In this work we compared metabolic profiles of WEHI7.2 parental cells with those of WEHI7.2 variants with an increased antioxidant defense or overexpressing bcl‐2, to determine whether bolstering the antioxidant defense results in altered metabolic parameters that could translate into increased resistance to dexamethasone‐induced apoptosis. WEHI7.2 parental cells and cells overexpressing catalase, thioredoxin or bcl‐2, or selected for resistance to 200 µM H2O2 were cultured in low‐glucose DMEM medium supplemented with 10% calf serum, and extracted using chloroform–methanol–water (1:1:1). Metabolites contained in the aqueous and organic phases of the extracts were processed separately and subjected to high‐resolution 31P NMR spectroscopy. In most of the steroid‐resistant variants, ATP levels and energetic status were decreased compared with the steroid‐sensitive parental cell line, while the concentrations of hexose and triose phosphates were increased. Furthermore, the ratio of choline‐containing phospholipids to ethanolamine‐containing phospholipids was generally reduced in steroid‐resistant cells. Phosphatidylethanolamine and its derivatives contain a higher amount of polyunsaturated fatty acids (PUFA) than the choline‐containing analogs, and PUFA are readily oxidized by reactive oxygen species. Therefore, an increased initial amount of phosphatidylethanolamine may increase the ‘buffering capacity’ of this antioxidant and may thus contribute to the steroid resistance of WEHI7.2 variants. Copyright © 2002 John Wiley & Sons, Ltd.
Study of delay patterns of weighted voice traffic of end‐to‐end users on the VoIP network
Authors: Han Jeong‐Soo , Ahn Seong‐Jin , Chung Jin‐Wook
Published: August 2002

In this paper we study delay patterns of weighted voice traffic of end‐to‐end users on the Voice over Internet Protocol (VoIP) network. We compare the delay performance of voice traffic which varies with queue management techniques such as First‐In First‐Out (FIFO) and Weighted Fair Queuing (WFQ) and voice codec algorithms such as G.723 and G.729 and select an optimal algorithm. Copyright © 2002 John Wiley & Sons, Ltd.
Reducing signaling traffic in wireless ATM networks through handoff scheme improvement
Authors: Hać Anna , Zhang Yongcan
Published: August 2002

We propose a new handoff call management scheme which reduces signaling traffic in wireless ATM networks and improves the efficiency of the virtual channel. Chaining followed by a make‐break algorithm is a suitable handoff scheme for various situations. In the chaining part of the scheme, a chain routing algorithm is studied and compared with the hop‐limiting scheme. When the algorithm is implemented in our scheme, it improves the performance of the existing scheme in call drop rates so as to reduce the signaling traffic in wireless ATM networks. Copyright © 2002 John Wiley & Sons, Ltd.
Network management abroad
Authors: Hendriks J. C. W. , Spruit M. E. M. , Looijen M.
Published: August 2002

This paper presents a number of interim results of a survey that, on the basis of a case study, establishes links between conditions in various countries and steering the management of an international network. It shows that the impact of factors in other countries on the network can largely be controlled from within an organization. Copyright © 2002 John Wiley & Sons, Ltd.
Traffic behavior analysis and modeling of sub‐networks
Authors: Chen Yen‐Wen
Published: August 2002

In this paper, the characteristics of sub‐network traffic is analyzed from the correlation point of view. It is easy to see that the traffic histogram of a sub‐network has a 24‐hour seasonal variation due to daily usage behavior. The auto correlation factor (ACF) and partial auto correlation factor (PACF) tests are applied first to examine the correlation of the traffic among consecutive hours and the correlation with a specific hour. The seasonal auto‐regressive integrated moving average (ARIMA) model is applied to characterize the above properties of the network traffic. Modeling performance is evaluated by examining the coincidence of the histogram and the moving average of traffic volume between the actual traffic collected from the network and the traffic generated by the proposed model. The experimental results illustrate that the proposed model can effectively capture traffic behaviors of the sub‐network and can then be used as a suitable traffic model for analysis of Internet performance. Copyright © 2002 John Wiley & Sons, Ltd.
Relaxation iterative algorithms for solving cathodic protection systems with non‐linear polarization curves
Authors: Sun W.
Published: August 2002

This paper discusses the calculation of potential distribution of impressed cathodic protection (CP) models with non‐linear polarization curves. We propose a relaxation iterative algorithm for the non‐linear problem and prove both theoretically and numerically that this iterative sequence is convergent for any physical polarization curves. This feature is of significant importance in developing a computer code for the design of CP systems. Copyright © 2002 John Wiley & Sons, Ltd.
Semi‐discretization method for delayed systems
Authors: Insperger Tamás , Stépán Gábor
Published: August 2002

The paper presents an efficient numerical method for the stability analysis of linear delayed systems. The method is based on a special kind of discretization technique with respect to the past effect only. The resulting approximate system is delayed and also time periodic, but still, it can be transformed analytically into a high‐dimensional linear discrete system. The method is applied to determine the stability charts of the Mathieu equation with continuous time delay. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluation of three unstructured multigrid methods on 3D finite element problems in solid mechanics
Authors: Adams Mark
Published: August 2002

Multigrid has been a popular solver method for finite element and finite difference problems with regular grids for over 20 years. The application of multigrid to unstructured grid problems, in which it is often difficult or impossible for the application to provide coarse grids, is not as well understood. In particular, methods that are designed to require only data that are easily available in most finite element applications (i.e. fine grid data), constructing the grid transfer operators and coarse grid operators internally, are of practical interest. We investigate three unstructured multigrid methods that show promise for challenging problems in 3D elasticity: (1) non‐nested geometric multigrid, (2) smoothed aggregation, and (3) plain aggregation algebraic multigrid. This paper evaluates the effectiveness of these three methods on several unstructured grid problems in 3D elasticity with up to 76 million degrees of freedom. Published in 2002 by John Wiley & Sons, Ltd.
Material state remapping in computational solid mechanics
Authors: Rashid M. M.
Published: August 2002

A computational procedure for remapping material state information from one finite element mesh to another is described. The procedure is useful in connection with evolving meshes for inelastic problems, as for example occur in the context of fracture simulation and adaptive mesh refinement. The proposed method is based on weak enforcement of equality between corresponding fields on the two meshes, where piecewise‐constant fields on both meshes are generalized from the quadrature‐point values. The essential algorithmic problem is that of calculating the volume partition of an arbitrary convex region with respect to a covering set of disjoint convex regions. Instead of geometrically resolving the associated intersections, the problem is herein approximated by a constrained optimization problem, which may be readily and efficiently solved computationally. This formulation is a main contribution of the paper. Computational examples are given that illustrate the effectiveness of the proposed procedure. Copyright © 2002 John Wiley & Sons, Ltd.
Mesh data structure selection for mesh generation and FEA applications
Authors: Garimella Rao V.
Published: August 2002

The data structure representing a mesh and the operators to create and query such a database play a crucial role in the performance of mesh generation and FE analysis applications. The design of such a database must balance the conflicting requirements of compactness and computational efficiency. In this article, 10 different mesh representations are reviewed for linear tetrahedral and hexahedral meshes. A methodology for calculating the storage and computational costs of mesh representations is presented and the 10 data structures are analysed. Also, a system for ranking different data structures based on their computational and storage costs is devised and the various mesh representations are ranked according to this measure. Copyright © 2002 John Wiley & Sons, Ltd.
Application of proper orthogonal decomposition to the discrete Euler equations
Authors: Pettit C. L. , Beran P. S.
Published: August 2002

The response of a fluid moving above a panel to localized oscillation of the panel is predicted using reduced‐order modelling (ROM) with the proper orthogonal decomposition technique. The flow is assumed to be inviscid and is modelled with the Euler equations. These non‐linear equations are discretized with a total‐variation diminishing algorithm and are projected onto an energy‐optimal subspace defined by an energy‐threshold criterion applied to a modal representation of time series data. Results are obtained for a bump oscillating in a Mach 1.2 flow. ROM is found to reduce the degrees of freedom necessary to simulate the flowfield by three orders of magnitude while preserving solution accuracy. Other observed benefits of ROM include increased allowable time step and robustness to variation of oscillation amplitude. Published in 2002 by John Wiley & Sons, Ltd.
Lower bound limit analysis using non‐linear programming
Authors: Lyamin A. V. , Sloan S. W.
Published: August 2002

This paper describes a new formulation, based on linear finite elements and non‐linear programming, for computing rigorous lower bounds in 1, 2 and 3 dimensions. The resulting optimization problem is typically very large and highly sparse and is solved using a fast quasi‐Newton method whose iteration count is largely independent of the mesh refinement. For two‐dimensional applications, the new formulation is shown to be vastly superior to an equivalent formulation that is based on a linearized yield surface and linear programming. Although it has been developed primarily for geotechnical applications, the method can be used for a wide range of plasticity problems including those with inhomogeneous materials, complex loading, and complicated geometry. Copyright © 2002 John Wiley & Sons, Ltd.
Flow‐induced vibrations of non‐linear cables. Part 1: Models and algorithms
Authors: Evangelinos C. , Lucor D. , Su C.‐H. , Karniadakis G. E.
Published: August 2002

In this paper, we develop governing equations for non‐linear cables as well as a formulation for the coupled flow‐structure problem. The structure is discretized with second‐order accuracy while the flow is discretized using spectral/hp elements in the context of the arbitrary Lagrangian–Eulerian formulation (ALE). Several benchmark problems are considered and the computational implementation is detailed. In the second part of this work large‐scale simulation examples are presented. Copyright © 2002 John Wiley & Sons, Ltd.
A bipartite patella in a juvenile from a medieval context
Authors: Anderson T.
Published: August 2002

One hundred and thirty six well‐preserved medieval skeletons were excavated in advance of re‐development in Norwich. The right patella of a 13–15 year old skeleton (SK 65) displays a ‘fracture line’ running through the supero‐lateral pole. This represents the fusion of a secondary ossification centre, a condition known as bipartite patella. It should not be confused with other anatomical variants or with pathological processes. Copyright © 2002 John Wiley & Sons, Ltd.
Microscopic evidence for Paget's disease in two osteoarchaeological samples from early northern France
Authors: Roches Elisabeth , Blondiaux Joël , Cotten Anne , Chastanet Patrick , Flipo René‐Marc
Published: August 2002

Paget's disease is a chronic condition of unknown cause localized to one or more bones of the human skeleton. It is basically an abnormal and excessive remodelling of bone, alternating phases of active bone resorption and formation and quiescent phases of diminished bone turnover. This combination produces a diagnostic pathologic appearance characterized by irregular bony fragments with a thickened and disorganized trabecular pattern (mosaic). To date, only two histological confirmations, although disputable, have been reported in medieval and 16th century samples from England (Aaron et al. 1992, Bell & Jones, 1991). This paper presents evidence of the disease from two sites in Normandy. The first one, Lisieux 413, dates from 300–350 AD and the second one, Saint Pierre‐sur‐Dives 16, dates from 1000–1100 AD. The remains were examined macroscopically, radiologically and microscopically. [Paget's disease was suspected in Lisieux 413 based on…] Paget's disease was suspected in Lisieux based on gross morphology of the calvarium. In the case of Saint Pierre‐sur‐Dives 16 Paget's was suspected based on the pelvis, the left femur proximal thickening and a fragmented vertebra. Radiographs showed in both cases osteolytic and osteosclerotic stages of the disease. Thick sections (70 µ) from both skeletal lesions (calvarium of Lisieux 413 and femur of Saint Pierre‐sur‐Dives 16) demonstrated the earliest observations of the mosaic pattern of cement lines joining areas of lamellar bone in thickened trabeculae. Paget's evidence in palaeopathology ought to be based on the association of macroscopic, radiographic and microscopic features. Copyright © 2002 John Wiley & Sons, Ltd.
A probable case of metastatic carcinoma from the late prehistoric eastern Tennessee River Valley
Authors: Smith Maria Ostendorf
Published: August 2002

There are few described cases of metastatic carcinoma from the prehistoric eastern United States and none primarily differentially diagnosed from the southeast. A mature adult female exhibiting several large lytic cranial lesions suggestive of neoplastic disease was identified in a late prehistoric Mississippian Period (AD 1200–1600) context. Burial 371 is from Ledford Island, a Mouse Creek phase (AD 1400–1500) site from the Chickamauga Reservoir of southeastern Tennessee. It is the only case in this reservoir (total adult n = 843). The radiographs of the otherwise asymptomatic postcranium yielded radiolucencies in both proximal femora, both medial clavicles, the sternum, the surviving humeral metaphysis and fragmentary innominate. The locations are all consistent with metastasized carcinoma. The identity of the possible primary lesion is argumentative. Age, sex and the mixed nature of the osseous response are consistent with carcinoma of the breast but not to the exclusion of bronchogenic, thyroid, or kidney cancers. Copyright © 2002 John Wiley & Sons, Ltd.
Analysis of interobserver scoring patterns in porotic hyperostosis and cribra orbitalia
Authors: Jacobi Keith P. , Danforth Marie Elaine
Published: August 2002

The role of scoring standards has become increasingly important during the last ten years because of issues such as reburial and comparability of data among researchers. The present study considered the efficacy of a proposed standard for porotic hyperostosis and cribra orbitalia, two of the most commonly evaluated pathologies in skeletal analysis. Twenty scorers with varying experience in bioarchaeology and five scorers with no experience in bioarchaeology evaluated 21 partial skulls for three characteristics: presence of pathology, appearance of porosities, and degree of healing. Participants showed good levels of agreement (>80%) when a lesion was considered present, but most scorers never agreed that a specimen was free of pathology when, in fact, it was. Greater variation was seen in evaluation of porosity size among those cranial fragments with lesions. Determination of degree of healing showed even more diversity with 19 of 21 cases having all scoring options given. Level of experience did not appear to make a difference with respect to level of agreement. Virtually the same pattern of results was seen among the five individuals with no familiarity with porotic hyperostosis or cribra orbitalia but with some biological training. These findings suggest that further refinement, especially in the area of photographs and descriptions illustrating minimum and maximum representations of various scoring levels, are necessary to produce scoring standards for porotic hyperostosis and cribra orbitalia that are effective and reliable. Copyright © 2002 John Wiley & Sons, Ltd.
Hydrodynamic sorting in a coastal marine skeletal assemblage
Authors: Stojanowski Christopher M.
Published: August 2002

In this paper I evaluate the effects of wave and tidal erosion on element‐specific measures of phenotypic variability. Previous research has found a high correlation between skeletal weight, shape, and density and the transport potential of an element exposed to hydrodynamic forces. However, no previous studies have attempted to address the issue of within‐element sorting based on selective removal of only the smallest members of a given element class. I evaluate this hypothesis using a human skeletal sample from Bird Island (8DI52) located in Dixie County, Florida. This sample comprises two components, an eroded sample that was exposed during severe storm and tidal activity, and an uneroded sample excavated from primary context. The measurement‐specific means for the subcomponents were compared using Student's t and Wilcoxon tests and variability differences were evaluated based on standard deviations, coefficients of variation, and maximum/minimum indices. The data included maxillary and mandibular tooth dimensions and postcranial metrics. No evidence for selective winnowing based on within‐element size was found in this data set. Copyright © 2002 John Wiley & Sons, Ltd.
Spondylolysis in Inuit skeletons from Arctic Canada
Authors: Merbs Charles F.
Published: August 2002

Inuit skeletons from archaeological sites in Arctic Canada were examined for the presence of spondylolysis. The largest series represent the Thule culture and historic Inuit from northwest Hudson Bay and Labrador, and Sadlermiut from Southampton Island. The condition was found in 90 individuals, with a total of 120 affected vertebrae producing 198 hemi‐arch defect sites. As in other studies, L5 is affected most frequently, followed by L4 and L3, but examples of L1, L2, L6, and S1 involvement are represented. Incomplete separations account for 20% (40) of the 198 defects, and 5% (10) occur at sites other than interarticularis. Affected males outnumber females at a ratio of 2.4 to 1. The condition was found to increase in frequency from adolescence to young adulthood, and then decrease to middle adulthood and decrease again to old adulthood, but the drop in frequency with age in the adult categories is significant only at the .20 level. Where comparisons could be made, the data obtained from the Canadian Inuit closely resemble those obtained from Alaskan Eskimos and Aleuts, especially their closest linguistic relatives, Inupiat speakers in northern Alaska. Copyright © 2002 John Wiley & Sons, Ltd.
Large fontanelles in an early 20th century rural population from South Africa
Authors: Steyn M. , Meiring J. H. , Nienaber W. C. , Loots M.
Published: August 2002

Unusually large fontanelles were found in four skeletons of children from a cemetery in the North West Province of South Africa. These remains date from the last decade of the 19th and first half of the 20th century. Three small infants (two of about nine months, and one of about six months) and one child (of about three years) were affected. In the case of the three‐year‐old child pathologic changes were evident on the rest of the skeleton, which probably resulted in the delayed closure. The cause of the unusually large fontanelles in the other three individuals is less clear. Some possibilities are discussed, but it seems as though general hardship and malnutrition, congenital syphilis or other infectious diseases like rubella syndrome may be involved. Copyright © 2002 John Wiley & Sons, Ltd.
Optimal control of an HIV immunology model
Authors: Joshi Hem Raj
Published: August 2002

A system of ordinary differential equations, which describes the interaction of HIV and T‐cells in the immune system is utilized, and optimal controls representing drug treatment strategies of this model are explored. Two types of treatments are used, and existence and uniqueness results for the optimal control pair are established. The optimality system is derived and then solved numerically using an iterative method with a Runge–Kutta fourth order scheme. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical optimization study of multiple‐pass aeroassisted orbital transfer
Authors: Rao Anil V. , Tang Sean , Hallman Wayne P.
Published: August 2002

A direct transcription method is applied to the problem of multiple‐pass aeroassisted orbital transfer from geostationary orbit to low Earth orbit with a large inclination change. The objective is to provide minimum‐impulse requirements and corresponding optimal trajectories for a gliding vehicle with a high lift‐to‐drag ratio subject to constraints on heating rate, angle of attack, and transfer time. The multiple‐pass aeroassisted orbital transfer problem is set up as a multi‐phase optimal control problem. All relevant parameters, including de‐orbiting, intermediate, and circularizing impulses, are optimized. Copyright © 2002 John Wiley & Sons, Ltd.
Policy of decentralization and changing governance of higher education in post‐Mao China
Authors: Mok Ka‐Ho
Published: August 2002

Unlike the Mao era when educational development was entirely directed by the central government, there has been a strong trend to diversification and decentralization of education in the post‐Mao period. This article, being set in this context, examines how the policy of decentralization has affected the governance modes of higher education in Mainland China. More specifically, the article focuses on three major aspects of education governance, namely, financing, provision and regulation in education, with special attention given to examining the changing relations between the state, local governments and other agents in education delivery. One very significant consequence of the change is that the public‐good functions of education, of which the state has taken the primary role of a reliable guarantor, have diminished. Nonetheless, the state's role as a regulator and overall service coordinator has been strengthened rather than weakened under the policy of decentralization. These recent developments in China's higher education also reflect the global trend of decentralization in educational governance. Copyright © 2002 John Wiley & Sons, Ltd.
Fostering subnational autonomy and accountability in decentralized developing countries: lessons from the Papua New Guinea experience
Authors: Edmiston Kelly D.
Published: August 2002

Using the experience of Papua New Guinea as a case study, this article examines the importance of political and administrative organization, electoral politics and revenue assignments for fostering subnational autonomy and accountability in decentralized developing countries, and hence the success of fiscal decentralization programmes. Copyright © 2002 John Wiley & Sons, Ltd.
Ethics revisited in a society in transition: the case of the former East Germany
Authors: Garcia‐Zamor Jean‐Claude
Published: August 2002

Since 1990, the German government has been demanding from the civil servants of the former East Germany a new adaptability and creativity that was never promoted in the GDR bureaucracy. The article analyses the change of ethics in the former East Germany after 1990. It looks at the development of the German civil service, discusses the economic disparity between East and West, and examines the ethical tradition in the former socialist country. It uses the case of the selection in 2001 of the city of Leipzig by BMW as the location of a new manufacturing plant as an illustration of the new goal‐oriented activities of the present Eastern bureaucracy. More than 250 European cities were competing for the new plant, which will create over 10,000 jobs. The level of performance of the Leipzig bureaucracy in the BMW case reveals the new efficiency and professionalism of the former Eastern civil service. In addition to Leipzig, virtually all the local and state administrations from the former East Germany have developed a sense of the necessities of the time, including globalization. Copyright © 2002 John Wiley & Sons, Ltd.
Conditionality, coercion and other forms of ‘Power’: international financial institutions in the Pacific
Authors: Larmour Peter
Published: August 2002

Research on conditionality has cast doubt on its effectiveness. Nevertheless, international financial institutions have continued to apply policy conditions to loans to developing country governments. The article aims to contribute to the current debate about conditionality in two ways. Empirically, it introduces recent evidence from countries and institutions not included in earlier studies (the World Bank and the International Monetary Fund in Papua New Guinea, and the Asian Development Bank in the South Pacific). Conceptually, it introduces arguments from political science to extend our understanding of the power relationships involved. Some conditions have clearly been applied coercively, particularly on ‘Green’ issues. Donors have also controlled the agenda of negotiations. But more productive and disciplinary forms of power are shown to be at work in conditionality, as in other forms of aid. Copyright © 2002 John Wiley & Sons, Ltd.
Executive agencies in Tanzania: liberalization and Third World debt
Authors: Caulfield Janice
Published: August 2002

The purchase of an expensive, debt‐financed aircraft tracking system by one of Tanzania's newly created executive agencies suggests that recent bureaucratic restructuring and liberalization in Tanzania could possibly undermine the good use of international debt management schemes for poverty alleviation. Moreover, it raises a question about the uses (and misuses), in countries where governance capacities are weak, of new public management models of organization. This article explores Tanzania's donor‐funded executive agency programme, as one part of its wider civil service reforms. Drawing on empirical research, it examines the power structures and interdependencies between Ministers, departments and NPM style semi‐autonomous agencies and the potential for rent‐seeking behaviour and perverse outcomes. Copyright © 2002 John Wiley & Sons, Ltd.
Capacity building for policy management through twinning: lessons from a Dutch–Namibian case
Authors: Olowu Dele
Published: August 2002

Three previous articles of Public Administration and Development carried a debate on the contribution of twinning to capacity building in developing countries. Evidence was adduced to show that twinning could be a reliable vehicle for building and sustaining relevant capacity. On the other hand, some other sources contend that twinning is more of a metaphor than an actual strategy for building capacity. As an actual strategy it may be costly and unsustainable. These cases were part of Swedish, Norwegian and Canadian aid programmes. This article adds insights from a project which was instituted at the instance of the government of Namibia with a Dutch development institution. The focus is in‐country training in policy management for senior public officials and is complemented by off‐the‐job training and programmed visits by both northern and southern partners. The project has four 20‐month cycles and is currently into its second cycle as plans for the third cycle are being finalised. It is generally regarded as successful although this article takes a critical look at the potential of this project to fulfil its original mission of building two types of institutional capacities: high‐quality policy managers within the government and the capacity for policy management training at the country's only national university. It highlights the importance of demand‐drivenness, ownership and partnership, effective integration of theory with practice, mutual respect among partners without jeopardising quality. It also suggests possible strategies for tackling some of the emerging problems. Copyright © 2002 John Wiley & Sons, Ltd.
Emulsion and miniemulsion polymerizations with an oil‐soluble initiator in the presence and absence of an aqueous‐phase radical scavenger
Authors: Luo Yingwu , Schork F. Joseph
Published: August 2002

Butyl acrylate conventional emulsion (macroemulsion) and miniemulsion polymerizations were carried out with an oil‐soluble initiator (azobisisobutyronitrile) in the presence or absence of an aqueous‐phase radical scavenger. For macroemulsion polymerization, in the presence of an aqueous‐phase radical scavenger, no particle nucleation occurred, whereas in the absence of an aqueous‐phase radical scavenger, particle nucleation proceeded as expected. For miniemulsion polymerization, the rate of polymerization was much higher in the absence of an aqueous‐phase radical scavenger than in its presence. Furthermore, in the absence of an aqueous‐phase radical scavenger, the miniemulsion polymerization rate increased with reduced droplet size, whereas in the presence of an aqueous‐phase radical scavenger, the trend was reversed. It is concluded that (1) for macroemulsion polymerization, the contribution from free radicals originating in the aqueous‐phase is predominant in the micellar nucleation of particles; (2) free radicals originating in the particle phase contribute to the rate of polymerization and the contribution increases with an increase in the particle size; and (3) for polymer particles with diameters of up to approximately 100 nm, polymerization is initiated from free radicals originating in the aqueous phase. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3200–3211, 2002
Spectroscopic study of the penetration depth of grafted polystyrene onto poly(tetrafluoroethylene‐co‐perfluoropropylvinylether) substrates. 1. Effect of grafting conditions
Authors: Cardona F. , George G. A. , Hill D. J. T. , Perera Seneka
Published: August 2002

This study concerns the radiation grafting of styrene onto poly(tetrafluoroethylene‐co‐perfluoropropylvinylether) (PFA) substrates and the penetration depth of the graft. Grafting was obtained by the simultaneous irradiation method, and the spectroscopic analysis was made with the micro‐Raman technique. Effects of grafting conditions such as the type of solvent, dose rate, and irradiation dose on the grafting yield were investigated. Of the different solvents used, the most efficient in terms of increasing grafting yield were dichloromethane, benzene, and methanol, respectively. A mixture of methanol and dichloromethane used as a solvent for styrene achieved a higher degree of grafting and concentration of grafted polystyrene onto the surface of PFA substrates than solutions of the monomer in the separate solvents. The degree of grafting increased with increasing radiation dose up to 500 kGy, stabilizing above this dose. However, the grafting yield decreased with an increase in the dose rate. The increase in the overall grafting yield was accompanied by a proportional increase in the penetration depth of the grafts into the substrate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3191–3199, 2002
Methylaluminoxane‐free ethylene polymerization with in situ activated zirconocene triisobutylaluminum catalysts and silica‐supported stabilized borate cocatalysts
Authors: Charoenchaidet Sumate , Chavadej Sumaeth , Gulari Erdogan
Published: August 2002

Heterogenization of tris(pentafluorophenyl)borane [B(C6F5)3] on a silica support stabilized with chlorotriphenylmethane (CICPh3) and N,N‐dimethylaniline (HNMe2Ph) creates the following supported borane cocatalysts: [HNMe2Ph]+[B(C6F5)3‐SiO2]− and [CPh3]+[B(C6F5)3‐SiO2]−. These supported catalysts were reacted with Cp2ZrCl2 TIBA in situ to generate active metallocene species in the reactor. Triisobutylaluminum (TIBA) was a good coactivator for dichloro‐zirconocene, acting as the prealkylating agent to generate cationic zirconocene (Cp2ZrC4H9+). The catalytic performances were determined from the kinetics of ethylene‐consumption profiles that were independent of the time dedicated to the activation of the catalysts. The scanning electron microscopy‐energy dispersive X‐ray measurements showed that B(C6F5)3 dispersed uniformly on the silica support. Under our reaction conditions, the [CPh3]+[B(C6F5)3‐SiO2]− system had higher productivity and weight‐average molecular weight than the [HNMe2Ph]+[B(C6F5)3‐SiO2]− system. For the [CPh3]+[B(C6F5)3‐SiO2]− system, the productivity increased with the amount catalyst; however, the polydispersity index of polyethylene synthesized did not change. The final shape of polymer particles was a larger‐diameter version of the original support particle. The polymer particles synthesized with supported [CPh3]+[B(C6F5)3‐SiO2]− catalysts had larger diameters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3240–3248, 2002
Decomposition of model alkoxyamines in simple and polymerizing systems. II. Diastereomeric N‐(2‐methylpropyl)‐N‐(1‐diethyl‐phosphono‐2,2‐dimethyl‐propyl)‐aminoxyl‐based compounds
Authors: Ananchenko Gennady S. , Souaille Marc , Fischer Hanns , Le Mercier Christophe , Tordo Paul
Published: August 2002

Thermal reactions of the alkoxyamine diastereomers DEPN‐R′ [DEPN: N‐(2‐methylpropyl)‐N‐(1‐diethylphosphophono‐2,2‐dimethyl‐propyl)‐aminoxyl; R′: methoxy‐carbonylethyl and phenylethyl] with (R,R) + (S,S) and (R,S) + (S,R) configurations have been investigated by 1H NMR at 100 °C. During the overall decay the diastereomers interconvert, and an analytical treatment of the combined processes is presented. Rate constants are obtained for the cleavage and reformation of DEPN‐R′ from NMR, electron spin resonance, and chemically induced dynamic nuclear polarization experiments also using 2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl (TEMPO) as a radical scavenger. The rate constants depend on the diastereomer configuration and the residues R′. Simulations of the kinetics observed with styrene and methyl methacrylate containing solutions yielded rate constants for unimeric and polymeric alkoxyamines DEPN‐(M)n‐R′. The results were compatible with the known DEPN mediation of living styrene and acrylate polymerizations. For methyl methacrylate the equilibrium constant of the reversible cleavage of the dormant chains DEPN‐(M)n‐R′ is very large and renders successful living polymerizations unlikely. Mechanistic and kinetic differences of DEPN‐ and TEMPO‐mediated polymerizations are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3264–3283, 2002
Synthesis and polymerization of phosphorus‐containing acrylates
Authors: Avci Duygu , Mathias Lon J.
Published: August 2002

Novel phosphorus‐containing acrylate monomers were synthesized by two different routes. The first involved the reaction of ethyl α‐chloromethyl acrylate and t‐butyl α‐bromomethyl acrylate with diethylphosphonoacetic acid. The monomers were bulk‐ and solution‐polymerized at 56–64 °C with 2,2′‐azobisisobutyronitrile. The ethyl ester monomer showed a high crosslinking tendency under these conditions. The selective hydrolysis of the ethyl ester phosphonic ester compound was carried out with trimethylsilyl bromide, producing a phosphonic acid monomer. In the second route, ethyl α‐hydroxymethyl acrylate and t‐butyl α‐hydroxymethyl acrylate were reacted with diethylchlorophosphate. The bulk homopolymerization and copolymerization of these monomers with methyl methacrylate and 2,2′‐azobisisobutyronitrile gave soluble polymers. The attempted hydrolysis of the monomers was unsuccessful because of the loss of the diethylphosphate group. The relative reactivities of the monomers in the photopolymerizations were also compared. The ethyl α‐hydroxymethyl acrylate/diethylphosphonic acid monomer showed higher reactivity than the other monomers, which may explain the crosslinking during the polymerization of this monomer. The reactivities of other derivatives were similar, but the rates of polymerization were slow in comparison with those of methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3221–3231, 2002
Diels–Alder modification of poly(ethylene terephthalate‐co‐anthracene‐2,6‐carboxylate) with N‐substituted maleimides
Authors: Vargas Marian , Kriegel Robert M. , Collard David M. , Schiraldi David A.
Published: August 2002

Dimethyl 2,6‐anthracene dicarboxylate is used as a comonomer in the synthesis of functional copolymers that are subject to modification with Diels–Alder reactions. The formation of poly(ethylene terephthalate‐co‐2,6‐anthracenate), containing less than 20 mol % of the anthracene‐2,6‐dicarboxylate structural units, provides materials that are tractable and soluble. The anthracene units of the copolymers undergo Diels–Alder reactions with N‐substituted maleimides. The grafting of N‐alkylmaleimides affords soluble, hydrophobic polymers, whereas grafting with maleimide‐terminated poly(ethylene glycol) affords hydrophilic polymers. Because this reaction proceeds below the melting point of the copolymers, the procedure can be applied to thin films, whereby the surface properties are modified. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3256–3263, 2002
Isobutene polymerization initiated by [CP*TiMe2]+ in the presence of a series of novel, weakly coordinating counteranions
Authors: Kumar K. Rajesh , Hall Chernoff , Penciu Anca , Drewitt Mark J. , McInenly Paula J. , Baird Michael C.
Published: August 2002

The highly electrophilic borane B(C6F5)3 reacts with n‐octadecanol (n‐C18H37OH) and n‐octadecanethiol (n‐C18H37SH) to form the 1:1 adducts (n‐C18H37EH)B(C6F5)3 (E = O or S). The latter are acidic and react with Cp*TiMe3 in methylene chloride and toluene to give methane and the complexes [Cp*TiMe2][(n‐C18H37E)B(C6F5)3], which are very good initiators for the carbocationic polymerization of isobutene (IB) from −40 to −20 °C. High conversions to high molecular weight polyisobutene (PIB) in methylene chloride and moderate conversions to high molecular weight PIB in toluene are observed and are consistent with the anions [(n‐C18H37E)B(C6F5)3]− being very weakly coordinating. Although polymerization in methylene chloride is too rapid for the temperature to be controlled, polymerization in toluene is slower, and the temperatures can be controlled so that Arrhenius‐type plots of the logarithm of the number‐average molecular weight versus T−1 = 1/T may be obtained. Activation energies for the degree of polymerization in these polymerization reactions and similar polymerizations carried out with n‐C18H37EH:borane ratios of 1:2 and with the activators [Ph3C][B(C6F5)4] and Al(C6F5)3 range from −11 to −27 kJ mol−1, values comparable to those for most conventional IB polymerization initiators. However, the values of the weight‐average and number‐average molecular weights are unusually high for the temperatures used, and this is consistent with current theories of the role of weakly coordinating anions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3302–3311, 2002
Synthesis and characterization of functional aliphatic copolyesters
Authors: Mani Ramaswamy , Bhattacharya Mrinal , Leriche Christian , Nie Li , Bassi Sukh
Published: August 2002

Functional aliphatic copolyesters of succinic acid (SA) and citric acid (CA) were synthesized via direct copolycondensation in the presence of 1,4‐butanediol, with titanium(IV) butoxide as a catalyst. The effects of the comonomer and comonomer ratio on the polycondensation and the melting and glass‐transition temperatures were investigated. The melting temperature was very sensitive to the molar ratio of the SA–CA comonomer units. The chain extension of this poly(butylene succinate citrate) was carried out with hexamethylene diisocyanate. The intrinsic viscosity, crystallinity percentage, and rheological properties of these copolyesters were also studied. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3232–3239, 2002
Photoinitiated polymerization of styrene from self‐assembled monolayers on gold. II. Grafting rates and extraction
Authors: Paul Rituparna , Schmidt Rolf , Feng Jianxin , Dyer Daniel J.
Published: August 2002

Ultrathin films of polystyrene (PS) were grown from self‐assembled monolayers by the “grafting‐from” technique. The initiating system consisted of a dithiol azobisisobutyronitrile‐type free‐radical initiator that was activated by irradiation at 300 nm. The thickness of the PS films ranged from 7 to 190 nm and could be controlled by varying the reaction time or the monomer concentration. The films were characterized by ellipsometry and Fourier transform‐reflection absorption infrared spectroscopy after Soxhlet extraction of residual physisorbed polymer. These films were unstable above 60 °C, and a water‐jacketed Soxhlet extractor was designed to maintain solvent temperatures below 45 °C during extraction. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3284–3291, 2002
Chemiluminescence of polyethylene: The comparative antioxidant effectiveness of phenolic stabilizers in low‐density polyethylene
Authors: Catalina Fernando , Peinado Carmen , Allen Norman S. , Corrales Teresa
Published: August 2002

The thermal stabilizing efficiency of a range of phenolic antioxidants (Lowinox CA22, Lowinox WSP, Lowinox TBP6, Irganox 3114, Irganox 1330, and Cyanox 1790) was determined in polyethylene films with chemiluminescence and hydroperoxide analysis and compared with standard systems based on Irganox 1010 and 1076. Under both nitrogen and oxygen conditions, good correlations were obtained between the two methods, confirming the importance and role of the hydroperoxide functionality and its stability in the oxidative process. Chemiluminescence decay rates correlated well with the initial corresponding hydroperoxide contents, which were measures of the antioxidant efficiencies in the polymer. The antioxidant structure and volatility (melting points) were important parameters to consider in any such correlations and related very much to the methodology and conditions of analysis (i.e., the temperature and atmosphere). Some of the antioxidants themselves under nitrogen exhibited strong chemiluminescence, which appeared to be a legacy associated with their manufacturing history and the partial oxidation of their structures, which gave peroxide functionalities. This was more notable for the complex antioxidant structures. Under oxygen, higher levels of chemiluminescence were observed, and this was indicative of some level of oxidation associated with the antioxidant structures. With temperature‐ramping experiments, the chemiluminescence emission was significant and only observed at temperatures close to the melting points of the additives and/or polymer. Mobility was clearly an essential feature of this reaction emission because chemiluminescence was well observed when the molten state was reached. Under normal practical conditions, such levels of chemiluminescence, because of employed stabilizers, do not contribute significantly to the chemiluminescence emissions of stabilized polymer materials. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3312–3326, 2002