bluuebunny/crossref_metadata_2025 huggingface dataset:
Free vibrations of shear‐flexible and compressible arches by FEM
Authors: Litewka Przemyslaw , Rakowski Jerzy
Published: August 2002

The purpose of this paper is to analyse free vibrations of arches with influence of shear and axial forces taken into account. Arches with various depth of cross‐section and various types of supports are considered. In the calculations, the curved finite element elaborated by the authors is adopted. It is the plane two‐node, six‐degree‐of‐freedom arch element with constant curvature. Its application to the static analysis yields the exact results, coinciding with the analytical ones. This feature results from the use of the exact shape functions in derivation of the element stiffness matrix. In the free vibration analysis the consistent mass matrix is used. It is obtained on the base of the same functions. Their coefficients contain the influences of shear flexibility and compressibility of the arch. The numerical results are compared with the results obtained for the simple diagonal mass matrix representing the lumped mass model. The natural frequencies are also compared with the ones for the continuous arches for which the analytically determined frequencies are known. The advantage of the paper is a thorough analysis of selected examples, where the influences of shear forces, axial forces as well as the rotary and tangential inertia on the natural frequencies are examined. Copyright © 2001 John Wiley & Sons, Ltd.
Toward large scale F.E. computation of hot forging process using iterative solvers, parallel computation and multigrid algorithms
Authors: Mocellin K. , Fourment L. , Coupez T. , Chenot J. L.
Published: August 2002

The industrial simulation code Forge3® is devoted to three‐dimensional metal forming applications. This finite element software is based on an implicit approach. It is able to carry out the large deformations of viscoplastic incompressible materials with unilateral contact conditions. The finite element discretization is based on a stable mixed velocity–pressure formulation and tetrahedral unstructured meshes. Central to the Newton iterations dealing with the non‐linearities, a preconditioned conjugate residual method (PCR) is used. The parallel version of the code uses an SPMD programming model and several results on complex applications have been published. In order to reduce the CPU time computation, a new solver has been developed which is based on multigrid theory. A detailed presentation of the different elements of the method is given: the geometrical approach based on embedded meshes, the direct resolution of the velocity–pressure system, the use of PCR method as an original smoother and for solving the coarse problem, the full multigrid method and the required preconditioning by an incomplete Cholesky factorization for problems with complex contact conditions. By considering different forging cases, the theoretical properties of the multigrid method are numerically verified, optimizations of the solver are presented and finally, the results obtained on several industrial problems are given, showing the efficiency of the new solver that provides speed‐up larger than 5. Copyright © 2001 John Wiley & Sons, Ltd.
Development of an instrument to measure patient perception of the quality of nursing care
Authors: Dozier Ann M. , Kitzman Harriet J. , Ingersoll Gail L. , Holmberg Sharon , Schultz Alison W.
Published: August 2002

Although patient satisfaction has been given considerable attention in health care, analysis of the conceptual and measurement limitations of existing measures indicates that a more elemental approach to obtaining patients' perspectives is warranted. In this investigation we developed and evaluated the psychometric properties of an instrument designed to measure patients' perceptions of the degree to which their needs were met while hospitalized. This 15‐item instrument, Patient Perception of Hospital Experience with Nursing (PPHEN), based on Swanson‐Kauffman's framework of caring, is internally consistent and represents a single construct best described as feeling cared for. The relationship of PPHEN to other measures demonstrates concurrent validity; moreover, the scale is responsive to differences in care provided, as shown by differences in means for different hospitals. PPHEN offers a brief, theoretically oriented, internally consistent, and valid patient self‐report measure of nursing care. It does not require patients to compare their expectations of care with the care received but only to evaluate whether their needs were met. It promises to be useful to clinical and health services researchers. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24:506–517, 2001
Popular participation and local government reform
Authors: Charlick Robert B.
Published: August 2002

Does decentralization, and particularly the creation of democratically elected local government, broaden mass political participation and make local government more effective and responsive? Evidence from two African Countries that have ‘democratized’ to varying degrees and through different approaches, this study makes two major points. First, although many of the hypotheses and initial findings of the Cornell Participation Project regarding the role of local organizations may still be valid, they remain largely untested in much of Africa because local government reform has been so limited and so recent. Second, in the limited number of cases where reform of local government has occurred in Africa, popular participation directed toward these governments can make them more responsive. This is only true, however, under particular circumstances, notably where projects with strong local and international non‐governmental organizational support chose to link to local government as well as to exert influence over policy at other levels of the political system. The fear expressed by some ‘civil society’ actors that the focus on local government may be narrowing the opportunities of non‐governmental associations to influence development policies is not confirmed in these cases. Copyright © 2001 John Wiley & Sons, Ltd.
Part 3. Copolymers of 1H,1H,2H,2H‐perfluorodecyl acrylate and 2,2,2‐trifluoroethyl methacrylate with butyl methacrylate
Authors: Lazzari Massimo , Chiantore Oscar , Castelvetro Valter
Published: August 2002

Copolymers of 2,2,2‐trifluoroethyl methacrylate, or 1H,1H,2H,2H‐perfluorodecyl acrylate (XFDA) and butyl methacrylate (BMA) have been irradiated in air under artificial solar light and their photo‐oxidative stability has been investigated. Molecular and chemical changes occurring during the treatments have been monitored by weight loss and gel content determination, size exclusion chromatography and FTIR spectroscopy. It has been determined that the overall behaviour of both copolymers is controlled by the BMA units, independently of the total fluorine content. The photo‐ageing takes place mainly via the mechanism of oxidation of methacrylic polymers containing long side ester groups, whose flexibility favours macroradical coupling reactions. The tendency to crosslink is balanced only in the case of the initial stages of degradation of XFDA/BMA by the scission reactions derived from the direct attack of oxygen on the fluorinated acrylic units.

© 2001 Society of Chemical Industry
Bending behaviour of electroresponsive poly(vinyl alcohol)/poly(acrylic acid) semi‐interpenetrating network hydrogel fibres under an electric stimulus
Authors: Fei Jiainqi , Zhang Zipeng , Gu Lixia
Published: August 2002

Poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) composite fibres were prepared via solution spinning and subsequently, semi‐interpenetrating networks (SIPN) were obtained by crosslinking the fibres with glutaraldehyde. The hydrogel fibres exhibited bending behaviour under DC electric stimulation. The effects of a number of factors have been systematically studied, including the PAA content within the network, electric voltage imposed across the fibre, the fibre diameter, concentration of the crosslinking agent, pH and ionic strength of the bath solution. Our experimental results show a stable reversibility of bending behaviour under the applied electric field. The degree of bending at equilibrium and the bending speed of the hydrogel fibre increased with the intensity of the applied electric voltage and the PAA content having negatively charged ionic groups within the SIPN. The electroresponsive behaviour of the present SIPN hydrogel fibre was also affected by the aforementioned extrinsic factors. These observations are interpreted in terms of fibre stiffness, fixed charge density and swelling pressure, which depend on the hydrogel equilibrium states in different pH and ionic environments together with the electrochemical reactions under DC electric field.

© 2002 Society of Chemical Industry
Acid‐catalyzed hydrolysis of bridged bi‐ and tricyclic compounds. XXXVIII—Kinetics and mechanisms of 1‐ and 3‐nortricyclanols
Authors: Lajunen Martti , Lahti Veli
Published: August 2002

The disappearance of 1‐ and 3‐nortricyclanols (1‐OH and 2‐OH) in aqueous perchloric acid was followed by capillary GC at different temperatures and acid concentrations. 1‐OH is ca 1000 times more reactive than 2‐OH. The activation parameters, solvent deuterium isotope effects and parameters of excess acidity equations were measured and the products were studied. Both isomeric nortricyclanols react according to the AdE2 mechanism, i.e. the cyclopropane ring is protonated at the rate‐determining stage of the reaction. The protonation causes, in the case of 1‐OH, an isomerization called homoketonization with 2‐norbornanone as the only product and, in the case of 2‐OH, hydration, i.e. the formation of hydroxyl‐substituted norbornyl cations, the fast attack of which by water produces several norbornanediols. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of hydroxy‐terminated, oligomeric poly(silarylene disiloxane)s via rhodium‐catalyzed dehydrogenative coupling and their use in the aminosilane–disilanol polymerization reaction
Authors: Homrighausen Craig L. , Keller Teddy M.
Published: August 2002

A series of oligomeric, hydroxy‐terminated silarylene–siloxane prepolymers of various lengths were prepared via dehydrogenative coupling between 1,4‐bis(dimethylsilyl)benzene [H(CH3)2SiC6H4Si(CH3)2H] and excess 1,4‐bis(hydroxydimethylsilyl)benzene [HO(CH3)2SiC6H4Si(CH3)2OH] in the presence of a catalytic amount of Wilkinson's catalyst [(Ph3P)3RhCl]. Attempts to incorporate the diacetylene units via dehydrogenative coupling polymerization between 1,4‐bis(dimethylsilyl)butadiyne [H(CH3)2SiCCCCSi(CH3)2H] and the hydroxy‐terminated prepolymers were unsuccessful. The diacetylene units were incorporated into the polymer main chain via aminosilane–disilanol polycondensation between 1,4‐bis(dimethylaminodimethylsilyl)butadiyne [(CH3)2NSi(CH3)2CCCC(CH3)2SiN(CH3)2] and the hydroxy‐terminated prepolymers. Linear polymers were characterized by Fourier transform infrared, 1H and 13C NMR, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis, and they were thermally crosslinked through the diacetylene units, producing networked polymeric systems. The thermooxidative stability of the networked polymers is discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1334–1341, 2002
FTIR, 13C NMR, and GPC analysis of high‐propylene content co‐ and terpolymers with ethylene and higher α‐olefins synthesized with EtInd2ZrCl2/MAO
Authors: Ferreira M. L. , Galland G. B. , Damiani D. E. , Villar M. A.
Published: August 2002

This article reports the results of propylene/α‐olefin copolymerization and propylene/ethylene/α‐olefin terpolymerization using low concentrations (less than 5 mol %) of long α‐olefins such as 1‐octene, 1‐decene, and 1‐dodecene. Kinetics data are presented and discussed. The highest activity was found with the longest α‐olefin studied (1‐dodecene). A possible explanation is proposed for this and other characteristics of the polymers obtained. The effect of low‐ethylene contents (4 mol % in the gas phase) on the copolymerization of propylene/α‐olefins was also examined. The polymers synthesized were characterized by 13C NMR, gel permeation chromatography, DSC, Fourier transform infrared spectroscopy, and wide‐angle X‐ray scattering. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2005–2018, 2001
Syndiospecific polymerization of styrene with BzCpTiCl3 and methylaluminoxane as cocatalysts
Authors: Schwecke Constantin , Kaminsky Walter
Published: August 2002

Benzyl cyclopentadienyl titanium trichloride (BzCpTiCl3) was synthesized from benzyl bromide, cyclopentadienyl lithium, and titanium tetrachloride and used in combination with methylaluminoxane (MAO) for the syndiospecific polymerization of styrene. Kinetic measurements of the polymerization were carried out at different temperatures. The polymerization with BzCpTiCl3/MAO differs from the polymerization with cyclopentadienyl titanium trichloride in its behavior toward the Al/Ti ratio. In addition, high activities are observed at high Al/Ti ratios. By analyzing the polymerization runs and the physical properties of the polymers with differential scanning calorimetry, 13C NMR spectroscopy, wide‐angle X‐ray scattering measurements, and gel permeation chromatography, we found that the phenyl ring coordinates to the titanium atom during polymerization. Other known substitutions of the cyclopentadienyl ring (V. Scholz, Dissertation, University of Hamburg, 1998) in principle influence the polymerization activity. The physical properties of the polymers produced by the catalysts already known are nearly identical. BzCpTiCl3 is the first catalyst that leads to polystyrene obviously different from the polystyrene produced by other highly active catalysts. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2805–2812, 2001
Two mechanisms of the fragmentation of thin coatings on rubber substrates
Authors: Bazhenov S. L. , Volynskii A. L. , Alexandrov V. M. , Bakeev N. F.
Published: August 2002

The fragmentation of thin platinum films, nanometers thick, deposited on isoprene rubber and poly(ethylene terephthalate) substrates was studied. Light and scanning electron microscopy was used. The length of a fragment depends on the thickness of the coating film and the tensile stress applied to the specimen. An equation describing the tensile stress in an elastic coating fragment is derived. The equation is used to analyze the fragmentation of a coating film under tension. Two stages of fragmentation are distinguished. At low strains, when the length of the fragments is lower than the ineffective length, fragmentation is occasional, as determined by defects in the coating. At high strains, the mechanism of fragmentation changes to the division of the fragments into halves. The division repeats when the load is doubled. During this stage of fragmentation, the crack density is proportional to the applied stress and reversibly proportional to the thickness of the coating. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 10–18, 2002
Network formation studied by temperature scanning brillouin scattering and differential scanning calorimetry techniques. II.
Authors: Castiglia S. R. V. , Fioretto D. , Verdini L. , Samios D.
Published: August 2002

The reaction of 1,4‐butanediol diglycidyl ether (EP) with cis‐1,2‐cyclohexanedicarboxylic anhydride (CH) and triethylamine (TEA) as an initiator was studied with temperature scanning Brillouin spectroscopy (TSBS) and differential scanning calorimetry (DSC). The evolution of the reaction process (liquid–gel–solid) was investigated as a function of the epoxy molar fraction (xEP), for sample compositions varying from an epoxy excess to an anhydride excess. The dependence of the final conversion factors αrDSC and αrTSBS and the kinetic parameters EDSC and ETSBS on xEP is presented. A comparison of the experimental gelation point (Pgel) behavior and the expected theoretical one, described by the Flory theory, is also reported. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1326–1336, 2001
Unexpectedly high young's moduli recorded for iPP/HDPE blends
Authors: Finlay J. , Sheppard S. , Tookey S. , Hill M. J. , Barham P. J.
Published: August 2002

Young's moduli of a series of quenched isotactic polypropylene/high‐density polyethylene blends were measured. The moduli of many of the blends exceeded the upper bound, calculated from the parallel model with the moduli of the two quenched homopolymers as those of the two components. In fact, both components crystallized at higher temperatures in the blends than they did on their own. It is argued that the higher crystallization temperatures of the components lead to higher component moduli and that this can explain the observation that the measured moduli of the blends apparently exceeded the upper bound. The implications of this work are discussed in light of other studies concerning the measurement and calculation of blend moduli. © 2001 John Wiley & Sons, Inc. J Polym Sci B Part B: Polym Phys 39: 1404–1414, 2001
Specific interaction governing the melt intercalation of clay with poly(styrene‐co‐acrylonitrile) copolymers
Authors: Lee Sang‐Soo , Lee Choon Soo , Kim Myong‐Hoon , Kwak Seung Yup , Park Min , Lim Soonho , Choe Chul Rim , Kim Junkyung
Published: August 2002

In the melt intercalation of cation‐exchange clay, mixtures of montmorillonite and poly(styrene‐co‐acrylonitrile) (SAN) with various acrylonitrile contents were studied to examine the effect of specific interaction. When organic molecules with hydroxyl groups were used as intercalants for the clay, the amount of SAN penetrating the gallery of the layered structure of the clay and the corresponding increase in the gallery height occurred at a much higher rate because of the attractive specific interaction between acrylonitrile groups and polar groups on the clay surface. However, there was a limit to the increase in the gallery height, and the tendency for the gallery height to increase with the acrylonitrile group content disappeared when the acrylonitrile content was greater than 30 wt %, implying that excessive attractive interaction on the clay surfaces and polymer molecules glued the two adjacent silicate layers together; consequently, the increase in the gallery height could not be accomplished. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2430–2435, 2001
The flare in alkaline phosphatase activity post‐orchidectomy predicts which patient may benefit from early chemotherapy in metastatic prostate cancer
Authors: Pelger Rob C.M. , Lycklama À Nijeholt Guus A.B. , Zwinderman Aielko H. , Hamdy Neveen A.T.
Published: August 2002

BACKGROUND

A flare in serum alkaline phosphatase (ALP) activity post‐orchidectomy has been shown to be of negative prognostic value for progression‐free survival (PFS) in patients with prostate cancer. The aim of this study was to investigate whether a flare in ALP may help identify patients in whom prognosis could be positively influenced by early chemotherapy.

METHODS

A retrospective analysis of the database of a Dutch multicenter study was conducted to evaluate the prognostic value of the flare in ALP post‐orchidectomy for survival and PFS in 112 patients treated with orchidectomy (previously reported) compared to 121 age‐ and stage‐matched patients additionally treated with estramustine‐phosphate (EMP) as first line therapy.

RESULTS

There was no overall difference in PFS and survival between the two treatment regimen. Subgroup analysis of patients demonstrating a greater than 50% increase in ALP post‐orchidectomy showed, however, a significant increase in PFS in patients additionally treated with EMP.

CONCLUSIONS

Our data suggest that the simple measurement of ALP activity within 4 weeks of castration represents a useful adjunct in assessing which patients with prostate cancer undergoing androgen ablation may benefit from additional early chemotherapy. Prostate 50: 119–124, 2002. © 2002 Wiley‐Liss, Inc.
Study of the conformational profile of the norbornane analogues of phenylalanine
Authors: Cordomí Arnau , Gomez‐Catalan Jesus , Jimenez Ana I. , Cativiela Carlos , Perez Juan J.
Published: August 2002

The conformational profile of the eight stereoisomeric 2‐amino‐3‐phenylnorbornane‐2‐carboxylic acids (2‐amino‐3‐phenylbicyclo[2.2.1]heptane‐2‐carboxylic acids) has been assessed by computational methods. These molecules constitute a series of four enantiomeric pairs that can be considered as rigid analogues of either L‐ or D‐phenylalanine. The conformational space of their N‐acetyl methylamide derivatives has been explored within the molecular mechanics framework, using the parm94 set of parameters of the AMBER force field. Local minimum energy conformations have been further investigated at the ab initio level by means of the Hartree‐Fock and second order Moller‐Plesset perturbation energy calculations using a 6–31G(d) basis set.

The results of the present work suggest that the bulky norbornane structure induces two kinds of conformational constraints on the residues. On one hand, those of a steric nature directly imposed by the bicycle on the peptide backbone and, on the other hand, those that limit the orientations attainable by the phenyl ring which, in turn, reduces further the flexibility of the peptide backbone. A comparative analysis of the conformational profile of the phenylnorbornane amino acids with that of the norbornane amino acids devoid of the β‐phenyl substituent suggests that the norbornane system hampers the residue to adopt extended conformations in favour of C7‐like structures. However, the bicycle itself does not impart a clear preference for any of the two possible C7 minima. It is the aromatic side chain, which is forced to adopt an almost eclipsed orientation, that breaks this symmetry introducing a marked preference for a single region of the (ϕ, ψ) conformational space in each of the phenylalanine norbornane analogues investigated. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Rydberg electron transitions of the atmospherically important molecule N2O
Authors: Velasco A. M. , Bustos E. , Martín I. , Lavín C.
Published: August 2002

Transition intensity data on Rydberg electronic transitions of N2O, which are relevant to atmospheric and astrophysical studies, are reported. The calculations have been performed with the molecular‐adapted quantum defect orbital method, which has proven to be an adequate theoretical tool in the context of Rydberg spectra. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 84: 70–77, 2001
An effective hopping model for weakly interacting π systems: Electronic structure of stacked polyaromatic hydrocarbons
Authors: Lázár Armand , Surján Péter R. , Paulsson Magnus , Stafström Sven
Published: August 2002

Parameters for effective hopping integrals are extracted from ab initio Hartree–Fock calculations on model systems. These effective hoppings can be used to describe the attractive part of the interaction of loosely bonded π‐electron systems of various orientations, such as interchain hoppings in conjugated polymers or those between two‐dimensional graphitic sheets. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 216–225, 2001
Fast characterization of intact proteins using a high‐throughput eight‐channel parallel liquid chromatography/mass spectrometry system
Authors: Feng Bingbing , Patel Arun H. , Keller Paul M. , Slemmon J. Randall
Published: August 2002

The preparation of protein substrates requires that a large number of chromatographic fractions be analyzed for the presence of reactants, products and by‐products. Analyses using linear matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) or single column liquid chromatography/mass spectrometry (LC/MS) have been inadequate because of mass resolution or throughput. Therefore, a high‐throughput method employing an eight‐channel parallel reverse‐phase LC/MS system was developed. This system is capable of screening fractions from preparative ion‐exchange chromatography with the required mass accuracy and throughput so that the protein purification process can be monitored in a relatively short period of time. As an example, the purification and analysis of an acylated protein with a molecular weight of 8.9 kDa is described and the detection of a contaminating by‐product that differs in size by less than 20 Da is demonstrated. Using the current instrumentation and approach, it is practical to analyze 50 protein‐containing fractions from column chromatography in less than 1 hour using parallel LC/MS. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of pyridoquinoline derivatives by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry
Authors: Picó Y. , Font G. , Balaña‐Fouce R. , Ordóñez C. , Abbas D. , Barbe J.
Published: August 2002

A method using liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI‐MS) has been developed for the characterization and determination of pyridoquinoline derivatives 4,6‐bis(dimethylaminoethylamino)‐2,8,10‐trimethylpyrido[3,2‐g]quinoline, 4,6‐bis(dimethylaminoethoxy)‐2,8,10‐trimethylpyrido[3,2‐g]quinoline and 4,6‐bis[(dimethylaminoethyl)thio]‐2,8,10‐trimethylpyrido[3,2‐g] quinoline, all with potential antitumor properties. LC separation was performed on a conventional C18 column using a binary mobile phase composed of acetonitrile and 50 mM aqueous ammonium formate at pH 3. The APCI mass spectra obtained showed that proton addition giving [M + H]+ was the common mode of ionization to the amino‐ and thiopyridoquinolines, whereas the alkoxypyridoquinoline was identified by the main formation of the [M − (C2H3)N(CH3)2 + H]+, followed by the [M + H]+ ion. The LC separation conditions and MS detection parameters were optimized for the determination. The analytical method was also applied to the determination of these pyridoquinoline derivatives in fetal calf serum using liquid‐liquid extraction with dichloromethane. Acceptable recovery values were obtained, ranging between 45 and 98%. Copyright © 2001 John Wiley & Sons, Ltd.
Electrospray ionization detection of inherently nonresponsive epoxides by peptide binding
Authors: Cech Nadja B. , Krone Jennifer R. , Enke Christie G.
Published: August 2002

A small organic molecule that is inherently nonresponsive to electrospray analysis, 1,3‐butadiene diepoxide, was analyzed via electrospray ionization (ESI) by binding it to various peptides and observing the product at the characteristic mass shift. The epoxide reacted only with peptides with arginines in their sequence, most likely through a base‐catalyzed ring opening to form a covalently bound product. A calibration curve linear over 3 orders of magnitude was generated for the butadiene diepoxide/peptide adduct. Several other epoxides were also reacted with the peptide of choice (angiotensin II), and adducts of these epoxides with the peptide were observed as well, demonstrating the versatility of this method for the analysis of small epoxides. This study demonstrates the possibility of assaying epoxides bound to peptides or proteins in biological samples. Furthermore, it demonstrates an important concept that could be applied to other analytical problems in electrospray: the ability to react an analyte that is nonresponsive to electrospray analysis with an analyte well suited for the technique, and accomplish quantitation based on the adduct formed between the two. Copyright © 2001 John Wiley & Sons, Ltd.
Quantitative estimates of precision for molecular isotopic measurements
Authors: Jasper John P.
Published: August 2002

At least three methods of calculating the random errors or variance of molecular isotopic data are presently in use. The major components of variance are differentiated and quantified here into least three to four individual components. The measurement of error of the analyte relative to a working (whether an internal or an external) standard is quantified via the statistical pooled estimate of error. A statistical method for calculating the total variance associated with the difference of two individual isotopic compositions from two isotope laboratories is given, including the variances of the laboratory (secondary) and working standards, as well as those of the analytes. An abbreviated method for estimation of of error typical for chromatographic/isotope mass spectrometric methods is also presented. Copyright © 2001 John Wiley & Sons, Ltd.
From passive to active dynamic walking
Authors: Ohta Hiroki , Yamakita Masaki , Furuta Katsuhisa
Published: August 2002

This paper is concerned with a walking robot with knees on level ground imitating the passive walking on a given slope. Basic principle of a proposed control method is that dynamics of the active walking robot is matched to that of the passive walking one. However, since it is hard for the knee‐jointed walking robot to successively or robustly realize a stable passive walking on the downhill slope, the passive walking robot is first actively controlled to continue to walk with an actuator at the hip. Then the dynamics of the walking robot on the level grand is matched to that of the stabilized passive walking robot on the slope by implementing actuators at the ankles as well as at the hip. Copyright © 2001 John Wiley & Sons, Ltd.
Factors contributing to attitude exchange amongst preservice elementary teachers
Authors: Palmer David H.
Published: August 2002

Previous research has shown that elementary education majors often dislike science and lack confidence in their ability to teach it. This is an important problem because students who hold these attitudes are likely to avoid teaching science, or teach it poorly, when they become teachers. It is therefore necessary to identify preservice elementary teachers who hold negative attitudes towards science, and attempt to convert these attitudes to positive before they become teachers. This study was designed to identify students whose attitudes had changed from negative to positive (i.e., attitude exchange had occurred) after participating in a one‐semester elementary science education course, and to identify the course factors that were responsible. Four participants were individually interviewed. The transcripts indicated that attitude exchange had occurred for each of the four students. Each student described several features of the course that had a positive influence. These were of three main types: personal attributes of the tutor, specific teaching strategies, and external validation. It was proposed that many of the individual factors were effective because they represented either “performance accomplishments” or “vicarious experience” as defined by Bandura (Psychological Review, 84, 1977, 191–215). © 2001 John Wiley & Sons, Inc. Sci Ed 86:122–138, 2001.
A wizard source of expertise in XPS
Authors: Castle James E.
Published: August 2002

X‐ray photoelectron spectroscopy has been in use for the study of materials for 30 years and with considerable success. In retrospect, however, it is clear that the many insights arising from work undertaken in the initial decade (the 1970s) are not well known to new users of the technique. Many of the simpler aids to interpretation, e.g. the use of shake‐up satellites, have stood the test of time and of more recent theoretical explanation and could easily be made available through help routines incorporated into the data system. Examples are given of the manner in which the help could be accessed by way of a screen ‘wizard’, which might also provide a stepping stone to the development of a full expert system. Copyright © 2002 John Wiley & Sons, Ltd.
Some statistical issues in modelling pharmacokinetic data
Authors: Lindsey J. K. , Jones B. , Jarvis P.
Published: August 2002

A fundamental assumption underlying pharmacokinetic compartment modelling is that each subject has a different individual curve. To some extent this runs counter to the statistical principle that similar individuals will have similar curves, thus making inferences to a wider population possible. In population pharmacokinetics, the compromise is to use random effects. We recommend that such models also be used in data rich situations instead of independently fitting individual curves. However, the additional information available in such studies shows that random effects are often not sufficient; generally, an autoregressive process is also required. This has the added advantage that it provides a means of tracking each individual, yielding predictions for the next observation. The compartment model curve being fitted may also be distorted in other ways. A widely held assumption is that most, if not all, pharmacokinetic concentration data follow a log‐normal distribution. By examples, we show that this is not generally true, with the gamma distribution often being more suitable. When extreme individuals are present, a heavy‐tailed distribution, such as the log Cauchy, can often provide more robust results. Finally, other assumptions that can distort the results include a direct dependence of the variance, or other dispersion parameter, on the mean and setting non‐detectable values to some arbitrarily small value instead of treating them as censored. By pointing out these problems with standard methods of statistical modelling of pharmacokinetic data, we hope that commercial software will soon make more flexible and suitable models available. Copyright © 2001 John Wiley & Sons, Ltd.
Software Maintenance: Concepts and Practice
Authors: Seaman Carolyn B.
Published: August 2002

Software Maintenance: Concepts and Practice is an excellent paperback book that comprehensively covers a breadth of software maintenance issues. It is more than adequate as a textbook for a university‐level course about software maintenance, although it has a few drawbacks in this respect (in particular a lack of technical guidance on key maintenance concerns such as impact analysis). In addition, it can be a useful reference for software researchers and, to a lesser extent, practitioners. Copyright © 2001 John Wiley & Sons, Ltd.
An empirical study of the influence of departmentalization and organizational position on software maintenance
Authors: Yeh Dowming , Jeng Jing‐Hwa
Published: August 2002

Differences between software development and maintenance imply that software maintenance work should be measured and managed somewhat differently from software development. On the other hand, maintenance programmers frequently perform the same tasks as development programmers do. How to departmentalize maintenance and development is thus becoming an issue. Departmentalization in software development and maintenance can be classified into two categories, maintenance separated from development and maintenance jointly with development. Departmentalization has its strengths and weaknesses. In this work, quantitative empirical methods are applied to investigate the influence of departmentalization on fulfillment opportunity, time allocations of activities, problem occurrences, and management process in software maintenance. Seven hypotheses are formed and tested by statistical methods. The result shows that separate organizations demonstrate specialization in software maintenance, but managerial attitudes also aggravate the potential status difference for such organizations. Other major pitfalls for departmentalization are also identified. Copyright © 2002 John Wiley & Sons, Ltd.
Post‐formal design conversation: designing just and caring educational systemsa
Authors: Horn Raymond A.
Published: August 2002

In the USA, efforts to improve education continue to be poorly designed and disregard the necessity of centering these efforts on paradigms of justice and caring. Change efforts, such as vouchers, standards, rebuilding educational infrastructure, funding and privatization, are systematic at best, and are promoted by ideological and economic special interests who have no concern for the establishment of egalitarian systems. Because of the lack of design and critical concern, the change efforts invariably fail in their attempt to improve the quality of education, and merely sustain existing inequitable situations. Currently, outside of the academic arena, design theory and critical theory have little impact on the contentious debates about the purpose, form, and function of education. Therefore, how can the process of design and the promotion of justice and caring be included in the actual planning and practice of educational change? The argument will be made that processes of design and criticality can become part of the practice of education, and that the quality of education can be equitably improved through the synthesis of idealized systems design and post‐formal thinking. This synthesis, post‐formal design conversation, will be explored by first identifying the aspects of systems design and post‐formal thinking that are related to this synthesis. A discussion of the similarities and differences of post‐formal design conversation and design conversation will further explicate the nature of post‐formal design conversation. Finally, the potential of Opportunity‐Initiated Systems design to become an interventionist strategy, which will promote the inclusion of post‐formal design conversation in educational change initiatives, will by explored. Copyright © 2001 John Wiley & Sons, Ltd.
Doing the right thing: the problems of…Gerard de Zeeuw, academic guerilla
Authors: Glanville Ranulph
Published: August 2002

A set of central themes, constituting both a method and an approach, demonstrated in the ‘Problems of…’ conference series over the last quarter century, are extracted from the work of Gerard de Zeeuw. These themes are based in a consideration of and concern for improvement, and an attempt to reduce the frequently negative side effects of attempts at improvement, by creating ‘high‐quality observations’ and empowering those helped by making them actors. Copyright © 2002 John Wiley & Sons, Ltd.
Epilogue
Authors: Chew‐Ogi Charlene , Ogi Alan Yoshiharu
Published: August 2002

The authors identify challenges for student affairs professionals and suggest responses and questions for more effective work with Asian American students.
Self‐administration of cocaine and the cocaine analog RTI‐113: Relationship to dopamine transporter occupancy determined by PET neuroimaging in rhesus monkeys
Authors: Wilcox K.M. , Lindsey K.P. , Votaw J.R. , Goodman M.M. , Martarello L. , Carroll F.I. , Howell L.L.
Published: August 2002

Dopaminergic mechanisms are thought to play a central role in the reinforcing effects of cocaine. The present study examined the reinforcing effects of 3β‐(4‐chlorophenyl)tropane‐2β‐carboxylic acid phenyl ester (RTI‐113), a long‐acting, selective, high‐affinity dopamine uptake inhibitor. Additionally, the effects of RTI‐113 pretreatment on cocaine self‐administration were determined. Monkeys were trained to respond under a second‐order schedule for intravenous cocaine administration (0.10 or 0.17 mg/kg/infusion). When responding was stable, cocaine (0.0030–1.0 mg/kg/infusion) and RTI‐113 (0.010–0.30 mg/kg/infusion) were substituted for the cocaine training dose. Cocaine and RTI‐113 were equipotent for their reinforcing effects. However, cocaine maintained higher response rates in two of the three monkeys tested. When administered as a pretreatment, RTI‐113 (0.10–0.30 mg/kg) dose‐dependently reduced responding maintained by two doses of cocaine. Drug effects on behavior were related to dopamine transporter (DAT) occupancy in monkey striatum during neuroimaging with positron emission tomography. DAT occupancy was determined by displacement of 8‐(2‐[18F]fluroethyl)2β‐carbomethoxy‐3β‐(4‐chlorophenyl)nortropane (FECNT). DAT occupancy was between 65–76% and 94–99% for doses of cocaine and RTI‐113 that maintained maximum response rates, respectively. DAT occupancy did not differ markedly across RTI‐113 pretreatment doses and ranged between 72–84%. The results suggest that the pharmacokinetic profile of RTI‐113 (i.e., long‐acting) may influence its ability to maintain self‐administration, and therefore its abuse liability. Additionally, high DAT occupancy is required for RTI‐113 to reduce cocaine‐maintained responding. Synapse 43:78–85, 2002. © 2001 Wiley‐Liss, Inc.
Making Sense of Student Written Comments
Authors: Lewis Karron G.
Published: August 2002

Written comments from students frustrate most faculty who read them. There are ways to interpret the information and use it to improve teaching.
Mobility management: from GPRS to UMTS
Authors: Lin Yi‐Bing , Haung Yieh‐Ran , Chen Yuan‐Kai , Chlamtac Imrich
Published: August 2002

This paper describes mobility management for the third‐generation mobile networks. We focus on the evolution from General Packet Radio Service (GPRS) to Universal Mobile Telecommunication System (UMTS). In this evolution, the radio access network UTRAN has been introduced, and radio‐related management is moved from the core network to UTRAN. We elaborate on how this architecture change affects the mobility management functionality, including the attach and detach procedures, location update, serving radio network controller relocation and intersystem change between GPRS and UMTS. Copyright © 2001 John Wiley & Sons, Ltd.
Cooperative functions of the mannoprotein‐encoding genes in the biogenesis and maintenance of the cell wall in Saccharomyces cerevisiae
Authors: Horie Tetsuro , Isono Katsumi
Published: August 2002

To elucidate the roles of genes involved in the cell wall biogenesis and function in Saccharomyces cerevisiae, we isolated and characterized mutants that were lethal in a strain in which the SED1 gene encoding a cell wall mannoprotein was disrupted. Thus, double mutants of SED1 and either MNN9 or MNN10 were unable to grow and YOL155c on a multicopy plasmid could suppress their synthetic lethality. A Yol155cp–GFP fusion protein was found to localize to the cell wall, suggesting that it might also be a cell wall mannoprotein. Subsequently, we analysed the effects of the shut‐off of SED1 in a sed1 and mnn9 double mutant: cells after the shut‐off showed anomalous cellular morphology and died in the mitotic M phase. From these and other results, we postulate that these genes function cooperatively with each other and in a cell cycle‐dependent manner in the biogenesis and maintenance of cell wall in S. cerevisiae. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation and Treatment of Chemotherapy Extravasation Injuries
Authors: Kassner Elizabeth
Published: August 2002

Extravasation of chemotherapeutic vesicant agents can result in significant tissue damage, alteration in limb function, and pain. Quality of life for long-term survivors can be severely impacted by negative sequelae from vesicant extrava sation. Currently, there is no known preventive therapy. Early detection and intervention are paramount to halt tissue damage and reduce the chance of permanent disability or disfigurement. This article provides an overview of known chemotherapeutic vesicants (mechlorethamine, mitomycin-C, doxorubi cin, daunomycin, vincristine and vinblastine), associated theories of tissue destruction, assessment techniques for peripheral intravenous sites, vascular access devices and central venous lines, current treatment strategies, and investigational therapies. A brief discussion of the legal implications of extrava sation injuries and recommended key points for medical record documentation are included.
Nitric Oxide, Mitochondria, and Cell Death
Authors: Brown Guy C. , Borutaite Vilmante
Published: August 2002

NO or its derivatives (reactive nitrogen species: RNS) have three types of actions on mitochondria: 1) reversible inhibition of mitochondrial respiration at cytochrome oxidase by NO, and irreversible inhibition at multiple sites by RNS; 2) stimulation of mitochondrial production of superoxide, hydrogen peroxide, and peroxynitrite by NO; and 3) induction of mitochondrial permeability transition (MPT) by RNS. Similarly there are three main roles of mitochondria in NO‐induced cell death: a) NO inhibition of respiration can induce necrosis (or excitotoxicity in neurons) and inhibit apoptosis if glycolysis is insufficient to compensate, b) RNS‐ or oxidant‐induced signal transduction or DNA damage may activate the mitochondrial pathway to apoptosis, and c) RNS‐induced MPT may induce apoptosis or necrosis.
Regulation of HIF by the von Hippel‐Lindau Tumour Suppressor: Implications for Cellular Oxygen Sensing
Authors: Mole D. R. , Maxwell P. H. , Pugh C. W. , Ratcliffe P. J.
Published: August 2002

Hypoxia‐inducible factor (HIF) is central in coordinating many of the transcriptional adaptations to hypoxia. Composed of a heterodimer of α and β subunits, the α subunit is rapidly degraded in normoxia, leading to inactivation of the hypoxic response. Many models for a molecular oxygen sensor regulating this system have been proposed, but an important finding has been the ability to mimic hypoxia by chelation or substitution of iron. A key insight has been the recognition that HIF‐ α is targeted for degradation by the ubiquitin‐proteasome pathway through binding to the von Hippel‐Lindau tumour suppressor protein (pVHL), which forms the recognition component of an E3 ubiquitin ligase complex leading to ubiquitylation of HIF‐ α. Importantly, the classical features of regulation by iron and oxygen availability are reflected in regulation of the HIF‐ α/p VHL interaction. It has recently been shown that HIF‐ α undergoes an iron‐ and oxygen‐dependent modification before it can interact with pVHL, and that this results in hydroxylation of at least one prolyl residue (HIF‐1 α, Pro 564). This modification is catalysed by an enzyme termed HIF‐prolyl hydroxylase (HIF‐PH), and compatible with all previously described prolyl‐4‐hydroxylases HIF‐PH also requires 2‐oxoglutarate as a cosubstrate. The key position of this hydroxylation in the degradation pathway of HIF‐ α, together with its requirement for molecular dioxygen as a co‐substrate, provides the potential for HIF‐PH to function directly as a cellular oxygen sensor. However, the ability of these enzyme(s) to account for the full range of physiological regulation displayed by the HIF system remains to be defined.
Integrated Electrochemical Carbon Capture and Utilization by Redox‐Active Amine Grafted Gold Nanoparticles
Authors: Yan Tao , Liu Shuo , Liu Zhikun , Sun Jie , Kang Peng
Published: January 2024

Electrochemical carbon capture and utilization (eCCU) from flue gas CO2 could avoid high energy consumption and capital input in conventional capture, storage, and utilization, which is a promising approach for achieving negative emissions and producing “e‐chemicals.” However, low CO2 concentration and leftover O2 in the flue gas presumably lowers the eCCU performance. Herein, redox‐active 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole (AMT) functionalized gold nanoparticles are synthesized to achieve integrated electrochemical capture and reduction of CO2 in simulated flue gas (SFG, 15% CO2, 4% O2, balanced with N2), achieving maximum CO Faradaic efficiency of 80.2% at −0.45 V versus RHE in H‐type cell, and 66.0% at voltage of 2.7 V in a full cell, respectively. The AMT ligand can capture CO2 by strong interaction with CO2 in the reduced state and serve as a selective layer to suppress O2 reduction, which provides the ability of electrochemical carbon capture from SFG and significantly decreases energy required for CO2 electro‐reduction.