bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Pot Synthesis of Sialo‐Containing Glycosyl Amino Acids by Use of an N‐Trichloroethoxycarbonyl‐β‐thiophenyl Sialoside
Authors: Tanaka Hiroshi , Adachi Masaatsu , Takahashi Takashi
Published: December 2004

We describe an efficient synthesis of 2,6‐ and 2,3‐sialyl T antigens linked to serine in a one‐pot glycosylation. We first investigated the glycosidation of thiosialosides by varying the N‐protecting group. Modification of the C‐5 amino group of β‐thiosialosides into the N‐9‐fluorenylmethoxycarbonyl, N‐2,2,2‐trichloroethoxycarbonyl (N‐Troc), and N‐trichloroacetyl derivatives enhanced the reactivity of these compounds towards glycosidation. Addition of a minimum amount of 3 Å molecular sieves was also effective in improving the yield of α‐linked sialosides. Next, we conducted one‐pot syntheses of the glycosyl amino acids by using the N‐Troc sialyl donor. The N‐Troc derivative can be converted into the N‐acetyl derivative without racemization of the amino acids. Branched‐type one‐pot glycosylation, initiated by regioselective glycosylation of the 3,6‐dihydroxy galactoside with the N‐Troc‐β‐thiophenyl sialoside, provided the protected 2,6‐sialyl T antigen in good yield. Linear‐type one‐pot glycosylation, initiated by chemoselective glycosylation of galactosyl fluoride with the N‐Troc‐β‐thiophenyl sialoside, afforded the protected 2,3‐sialyl T antigen in excellent yield. Both protected glycosyl amino acids were converted into the fully deprotected 2,6‐ and 2,3‐sialyl T antigens linked to serine in good yields.
Fine‐needle aspiration cytology of a liver metastasis of follicular dendritic cell sarcoma
Authors: Ren Rulong , Sun Xiaoping , Staerkel Gregg , Sneige Nour , Gong Yun
Published: December 2004

Follicular dendritic cell sarcoma (FDCS) is an uncommon neoplasm derived from FDCs in lymphoid tissue. Metastatic FDCS to the liver is rare. We present a case of a 65‐yr‐old woman who was referred to our institution 1 mo after splenectomy for FDCS of the spleen. An abdominal CT scan revealed a 2.0‐cm liver lesion, which led to fine‐needle aspiration (FNA) biopsy. Smears of the aspiration obtained were hypercellular showing a pleomorphic population of large oval to spindle‐shaped tumor cells against a background of small mature lymphocytes, plasma cells, and necrotic debris. Tumor cells were arranged singly, in syncytial or fascicular patterns, and had a moderate amount of cytoplasm and indistinct cell borders. Nuclei had irregular nuclear membranes, finely granular to vesicular chromatin, and prominent nucleoli. Multinucleated and binucleated cells resembling Reed‐Sternberg cells were noted occasionally. Mitotic figures, including atypical forms, were frequently identified. The diagnosis of “pleomorphic malignant spindle‐cell neoplasm consistent with metastatic FDCS” was rendered and later confirmed by histological review and immunohistochemical staining of the subsequent liver resection specimen. Although cytological features of FDCS are characteristic, they are overlapping with those of many other tumors. We review the literature on this entity with emphasis on FNA cytomorphology, differential diagnosis, and immunohistochemical findings. Diagn. Cytopathol. 2005;32:38–43. © 2005 Wiley‐Liss, Inc.
Chromatin pattern alteration in malignant cells: An enigma
Authors: Dey Pranab
Published: December 2004

Alteration of chromatin pattern is one of the most important clues to detect the malignant cell. However, the exact cause of change of chromatin pattern still is not clearly known. Recently, in last 20 yr, modern advanced technologies, such as fluorescent in situ hybridization (FISH), chromosome painting, green fluorescent protein (GFP) fusion technology, fluorescent recovery after photobleaching (FRAP), confocal microscopy, and multicolor four‐dimensional imaging of living cell, have unfolded the mystery of the chromatin structure and dynamics. In this study, I have discussed the possible causes of chromatin change in malignant cells based on available recent information. Multiple factors are responsible for alteration of chromatin pattern in malignant cells. The important factors in this respect are chromatin relocation, DNA aneuploidy, change of nuclear matrix protein (NMP), histone protein alteration, abnormal nuclear lamin‐chromatin interaction, and nuclear pore dysfunction. It is not impossible that the chromatin pattern alteration may be just a secondary change due to the interaction of fixative with chromatin and nonchromatinic substances in the nucleus. Diagn. Cytopathol. 2005;32:25–30. © 2005 Wiley‐Liss, Inc.
Basidiomycetes and larger Ascomycetes from Yemen
Authors: Kreisel H. , Al‐Fatimi M.
Published: December 2004

From the territory of Yemen 39 taxa of larger fungi (macromycetes: 36 Basidiomycetes and three Ascomycetes), including former records in literature, are enumerated and annotated. 22 taxa have been collected in recent times; 16 of them are first records from Yemen.

Actually eight taxa are known from the highlands, 16 taxa from the coastal lowland, and 15 taxa (only very old records) from the island Socotra. Constituents of the macromycete flora of Yemen are species of south‐temperate to mediterranean distribution (mainly represented in the highlands), species of subtropical to tropical distribution (mainly represented in the lowlands) and nearly cosmopolitic elements. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vegetation pattern within a thermokarst landscape in the central Altay Mountains (West Siberia)
Authors: König P. , Rilke S.
Published: December 2004

In a mountain basin landscape influenced by a semi‐desert climate in the South Siberian Altay, a geobotanical study was conducted by placing a transect through a run‐off runnel and creating a vegetation map for the wet mire and meadow regions of the study area. The close proximity of semi‐desert and mire associations, formed by thermokarst phenomena, is noteworthy. The associations are presented in terms of their locations, and a phytogeographic classification of species is given. Comparisons with the conditions in NW Mongolia demonstrate the close relationships of dry slopes in the Chuya Basin with the typical Central Asian semi‐desert flora, which extends from the Great Lakes Basin into the southern desert zone of Mongolia. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phytosociological affinities and habitat preferences ofJuniperus sabinaL. andArtemisia santolinifoliaTurcz. exBess. in mountain sites of the south‐eastern Gobi Altay, Mongolia
Authors: Wesche K. , Ronnenberg K.
Published: December 2004

Plant community composition was analysed for 145 relevés, randomly sampled on steep slopes in the Gobi Gurvan Sayhan National Park, southern Mongolia. Cluster analysis designated seven communities into three main groups, namely mountain steppes, dominance stands of the dwarf shrubArtemisia santolinifolia, and scrub composed ofJuniperus sabina. Multivariate classifications corresponded well to available phytosociological classification schemes. Dense mountain steppes on northern exposures, as well as juniper stands on south‐ and east‐facing scree slopes, had high contents of organic matter and cations in the soil, while stands with disturbance‐tolerant species such asCarex stenophylla, annuals, orA. santolinifoliagrew on less favourable soils. Stands of the latter species showed some overlap withJ. sabinawith respect to species composition and site conditions, and specimens ofA. santolinifoliawere present in most relevés of juniper stands. The complete absence of juniper seedlings suggested an apparent potential replacing of ageing specimens ofJ. sabinabyA. santolinifolia.However, both species were distinct in cluster, ordination and correlation analyses, so this process seems to be still in its infancy. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduced‐size polarized basis sets for calculations of molecular electric properties. I. The basis set generation
Authors: Benkova Zuzana , Sadlej Andrzej J. , Oakes Roma E. , Bell Steven E. J.
Published: December 2004

Following the recent studies of basis sets explicitly dependent on oscillatory external electric field we have investigated the possibility of some further truncation of the so‐called polarized basis sets without any major deterioration of the computed data for molecular dipole moments, dipole polarizabilities, and related electric properties of molecules. It has been found that basis sets of contracted Gaussian functions of the form [3s1p] for H and [4s3p1d] for the first‐row atoms can satisfy this requirement with particular choice of contractions in their polarization part. With m denoting the number of primitive GTOs in the contracted polarization function, the basis sets devised in this article will be referred to as the ZmPol sets. In comparison with earlier, medium‐size polarized basis sets (PolX), these new ZmPol basis sets are reduced by 2/3 in their size and lead to the order of magnitude computing time savings for large molecules. Simultaneously, the dipole moment and polarizability data remain at almost the same level of accuracy as in the case of the PolX sets. Among a variety of possible applications in computational chemistry, the ZmPolX are also to be used for calculations of frequencies and intensities in the Raman spectra of large organic molecules (see Part II, this issue). © 2004 Wiley Periodicals, Inc. J Comput Chem 26: 145–153, 2005
MoCalc: A new graphical user interface for molecular calculations
Authors: Depizzol Daniela Bertolini , Paiva Marcia Helena Moreira , Dos Santos Thiago Oliveira , Gaudio Anderson Coser
Published: December 2004

A new computer program called MoCalc (Molecular Calculations) has been designed to help the computational chemistry practitioner in the task of performing and analyzing molecular calculations. MoCalc is a graphical user interface for the MO calculation programs Gamess and Mopac, and uses Rasmol and Babel for molecule display and file conversion, respectively. In its initial version, MoCalc can execute the following operations: (a) create and handle Gamess and Mopac input files; (b) import any kind of molecular geometry supported by Babel and paste it as Cartesian, internal, or Gaussian‐type coordinates on the input file; (c) convert Gamess and Mopac output files to inputs of both programs; (d) edit and validate the keywords that control the Gamess and Mopac calculation procedure; (e) display the input (Mopac) and output (Gamess and Mopac) molecular geometries; (f) run single or multiple (batch) calculations, either interactively or in background; (g) automatically open the output files as soon as the calculation finishes; (h) extract results from the output files, such as energy, charges, dipole, population analysis, wave function, bond orders, and valence analysis, and display them in spreadsheets; (i) calculate reactivity indices derived from the frontier orbital theory and the root‐mean‐square (rms) deviation of input and output geometries. All the results generated by MoCalc can be promptly transferred to text editors and electronic spreadsheets, which facilitate a detailed subsequent analysis and the publication of the results. MoCalc can also perform graphical and numerical comparative analysis of the some results when more than one output file is loaded. The program was coded in Visual Basic and runs in Windows 95/98/NT4/ME/2000/XP environments. © 2004 Wiley Periodicals, Inc. J Comput Chem 26: 142–144, 2005
Incorporating the effect of ionic strength in free energy calculations using explicit ions
Authors: Donnini Serena , Mark Alan E. , Juffer André H. , Villa Alessandra
Published: December 2004

The incorporation of explicit ions to mimic the effect of ionic strength or to neutralize the overall charge on a system in free energy calculations using molecular dynamics simulations is investigated. The difference in the free energy of hydration between two triosephosphate isomerase inhibitors calculated at five different ion concentrations is used as an example. We show that the free energy difference can be highly sensitive to the presence of explicit ions even in cases where the mutation itself does not involve a change in the overall charge. The effect is most significant if the molecule carries a net charge close to the site mutated. Furthermore, it is shown that the introduction of a small number of ions can lead to very severe sampling problems suggesting that in practical calculations convergence can best be achieved by incorporating either no counterions or by simulating at high ionic strength to ensure sufficient sampling of the ion distribution. © 2004 Wiley Periodicals, Inc. J Comput Chem 26: 115–122, 2005
Influence of C18 long chain fatty acids on butyrate degradation by a mixed culture
Authors: Mykhaylovin Oleksandr , Roy Jennifer M , Jing Nin , Lalman Jerald A
Published: December 2004

Butyrate degradation in the presence of C18 long chain fatty acids (LCFAs) was examined under anaerobic conditions at 21 °C. Butyrate degradation rates were a function of linoleic acid (LA) and oleic acid (OA) concentration but independent of the amount of stearic acid (SA) added. Within 2–4 h, butyrate reached undetectable levels in the control cultures. However, in cultures fed with LA, butyrate was removed within between 12 and 25 h and within 2–12 h for cultures inoculated with OA or SA. Propionate was detected in cultures fed with 50 mg dm−3 LA and in cultures inoculated with OA and SA. LA exerted a greater inhibitory effect on butyrate‐degrading organisms than OA and SA with longer removal times observed in cultures fed with LA. The propionate and acetate removal times and quantity produced were not related to the type and concentration of LCFA. Copyright © 2004 Society of Chemical Industry
Increased utility in the CNS of a powerful neuron‐specific tetracycline‐regulatable adenoviral system developed using a post‐transcriptional enhancer
Authors: Lee Youn‐Bok , Cosgrave A. Siobhan , Glover Colin P. J. , Bienemann Alison , Heywood Darren , Hobson Russell J. , Uney James B.
Published: December 2004

Background

In previous studies we have found that the tetracycline (Tet)‐regulatable system functions best in recombinant adenoviral (Ad) vectors when the Tet transactivators and the Tet‐regulatable element (TRE) are incorporated into separate viral vectors. However, such a dual vector system is disadvantaged by the need to use relatively high titres that may elicit an immune response. Therefore, to develop a system that could be used at low titres while mediating strong, tightly regulatable gene expression in the central nervous system (CNS), we incorporated the woodchuck hepatitis virus post‐transcriptional enhancer (WPRE) into a neuron‐specific Tet‐regulatable Ad system.

Methods

The WPRE was incorporated into Ad vectors encoding the Tet‐Off (tTA) transactivator driven by the synapsin‐1 and CMV promoters and encoding the TRE driving EGFP expression (TRE)‐EGFP.

Results

The addition of the WPRE to the neuron‐specific Tet‐regulatable system mediated a greater than three‐fold increase in transgene expression in primary hippocampal neurons with no loss of gene regulation. The results also showed that the addition of the WPRE enhanced transgene expression in the CNS without the loss of neuron specificity and without affecting the ability to regulate transgene expression.

Conclusions

We have further developed a tetracycline‐regulatable neuron‐specific expression system such that it can now be used at low titres with no loss of transgene expression or ability to regulate transgene expression. It should therefore be of significant value to studies investigating neuronal gene function and to those seeking to develop effective neuronal gene therapy strategies. Copyright © 2004 John Wiley & Sons, Ltd.
Block Copolymers of Vinyl Ethers as Thermo‐Responsive Colloidal Stabilizers of Organic Pigments in Aqueous Media
Authors: Bulychev Nikolay A. , Arutunov Igor A. , Zubov Vitali P. , Verdonck Beatrice , Zhang Tianzhu , Goethals Eric J. , Du Prez Filip E.
Published: December 2004

Summary: The colloidal stability of the aqueous dispersions of hydrophobic organic pigments, CuPc and carbon black, stabilized by a wide range of polymer structures based on alkyl vinyl ethers was studied. It was shown that, unlike the homopolymers and the random copolymers, the amphiphilic AB, ABA and BAB block copolymers of MVE with IBVE or ODVE show stabilizing activities that depend on their hydrophilic/hydrophobic balance and polymer architecture. After optimization, the colloidal stabilization is competitive with commercial PEO‐PPO block copolymers (Pluronic®). It was found that the sedimentation of the dispersions was much faster at a higher temperature, above the LCST of the PMVE‐blocks. The loss of the stabilizing activity of the block copolymers correlates with an increase of the hydrophobicity of the treated pigment surface. These properties enable the creation of colloidal dispersions with stabilities that can be tuned as a function of temperature.

Poly(methyl vinyl ether) ABA and BAB block copolymers as colloidal stabilizers of organic pigments.

magnified image

Poly(methyl vinyl ether) ABA and BAB block copolymers as colloidal stabilizers of organic pigments.
Interactions Between Polymer Brushes: Varying the Number of End‐Attaching Groups
Authors: Dunlop Iain E. , Briscoe Wuge H. , Titmuss Simon , Sakellariou Giorgos , Hadjichristidis Nikos , Klein Jacob
Published: December 2004

Summary: We use a surface force balance (SFB) to study the normal interactions between polymer brushes, which are self‐assembled from solution. They consist of polystyrene (PS) chains in toluene (neutral chains in a good solvent) anchored on the interacting mica surfaces via sulfozwitterionic end groups. The properties of the brush depend on the length, N, of the chain, and the energy, αkBT, with which the end group adsorbs on the surface. In contrast to earlier studies where N was varied, we attempt to vary the sticking energy by using polymer chains with one, two, and three zwitterions attached to their ends. We use the theory of Alexander and de Gennes to predict how the normal force profile should vary with α and N, finding, for example, that the brush height L0 obeys $L_0 = a \cdot N^{3/5} \cdot \alpha ^{2/5}$. Surprisingly, our measurements show that the grafting density does not vary significantly between polymers with 1, 2, and 3 end groups. This could be attributed to dipole‐dipole interactions between the zwitterions themselves. It is also possible that the effect could be kinetic: that the brush is unable to reach its equilibrium state because successive polymer chains are hindered from attaching to the surface by those already in the brush. Measurements on longer time scales will be necessary to determine whether kinetic effects are important.

magnified image
Tunable Microcellular Morphologies from Poly(ferrocenylsilane) Ceramic Precursors Foamed in Supercritical CO2
Authors: Frankowski David J. , Fournier‐Bidoz Sébastien , Manners Ian , Ozin Geoffrey A. , Khan Saad A. , Spontak Richard J.
Published: December 2004

Summary:Poly(ferrocenylmethylphenylsilane) (PFMPS) and poly[ferrocenylmethyl(phenylacetylido)silane] (PFMPAS) homopolymers are organometallic polymers that can serve as precursors to magnetically‐active ceramics. In this work, PFMPS and PFMPAS films ranging in thickness from 30 to 220 μm have been exposed to scCO2over a broad range of saturation pressures, temperatures and times to produce surface‐constrained microcellular polymeric foams. Electron microscopy identifies viable foaming windows and reveals that foams with submicron cell sizes can be generated by judicious selection of exposure conditions. Cell shape anisotropy can likewise be varied from being nearly spherical to vertically elongated. Curvature in the films and non‐negligible surface roughness create paths that facilitate CO2diffusion, resulting in the formation of “V‐directional” cells oriented at approximately 30° to the film surface. The development of bimodal cell size distributions is attributed to temperature variation during depressurization and/or stepwise homogeneous and heterogeneous nucleation. These results are prerequisite for the production of magnetically‐active porous ceramics from pyrolyzed PFS foams.

SEM image of a PFMPS foam generated in scCO2illustrating considerable cell anisotropy: the cells are tilted with respect to the film surface.

magnified image

SEM image of a PFMPS foam generated in scCO2illustrating considerable cell anisotropy: the cells are tilted with respect to the film surface.
Interrater agreement in the assessment of motor manifestations of Huntington's disease
Authors: Hogarth Penelope , Kayson Elise , Kieburtz Karl , Marder Karen , Oakes David , Rosas Diana , Shoulson Ira , Wexler Nancy S. , Young Anne B. , Zhao Hongwei ,   the United States–Venezuela Huntington's Disease Collaborative Research Group,   the Huntington Study Group
Published: December 2004

With prospects improving for experimental therapeutics aimed at postponing the onset of illness in preclinical carriers of the Huntington's disease (HD) gene, we assessed agreement among experienced clinicians with respect to the motor manifestations of HD, a relevant outcome measure for preventive trials in this population. Seventy‐five clinicians experienced in the evaluation of patients with early HD and six non‐clinicians were shown a videotape compiled from the film archives of the United States–Venezuela Collaborative HD Research Project. Observers were asked to rate a 2–3‐minute segment of the motor examination for each of 17 at‐risk subjects. The rating scale ranged from 0 (normal) to 4 (unequivocal extrapyramidal movement disorder characteristic of HD). As measured by a weighted κ statistic, there was substantial agreement among the 75 clinicians in the judgment of unequivocal motor abnormalities comparing scale ratings of 4 with ratings that were not 4 (weighted κ = 0.67; standard error (SE) = 0.09). Agreement among the non‐clinicians was only fair (weighted κ = 0.28; SE = 0.10). Even under the artificial conditions of a videotape study, experienced clinicians show substantial agreement about the signs that constitute the motor manifestations of illness in subjects at risk for HD. We expect these findings to translate to a similar level of interobserver agreement in the clinical trial setting involving experienced investigators examining live patients. © 2005 Movement Disorder Society
Trigeminally induced startle in children with hyperekplexia
Authors: Oguro Katsuhiko , Hirano Keiko , Aiba Hideo
Published: December 2004

To determine the physiological features of startle reactions in children with hereditary hyperekplexia, motor responses to auditory and trigeminal stimulation were investigated in 2 patients and 3 control subjects by means of multiple surface electromyographic recordings. The pattern of motor activation in auditory startle was similar in the two groups, although the responses in the patients were increased in terms of the extent of the responses. In the patients, nose taps elicited two separate responses in various muscles. The initial, short‐latency response was often elicited in all the muscles examined. This reflex was similar to the R1 component of the electrical blink reflex. In addition, the early reflex was immediately followed by the second response, which also appeared widely and was similar to R2 of the blink reflex. Taps on the supraorbital nerve elicited multiple startle patterns consisting of these two responses, although generalization was infrequent. In the control subjects, these responses were elicited in a few muscles. In the hyperekplectic children, both the early and second responses to trigeminal stimulation were increased, in addition to the audiogenic reflex. It was suggested that enhancement of these responses occurred due to hyperexcitability in the brainstem reticular formation in our patients. © 2004 Movement Disorder Society
Optimal power control in a wireless network using a model with stochastic link coefficients
Authors: Heikkinen T. , Prékopa A.
Published: December 2004

This paper addresses optimal power allocation in a wireless communication network under uncertainty. The paper introduces a framework for optimal transmit power allocation in a wireless network where both the useful and interference coefficients are random. The new approach to power control is based on a stochastic programming formulation with probabilisticSIRconstraints. This allows to state the power allocation problem as a convex optimization problem assuming normally or log‐normally distributed communication link coefficients. Numerical examples illustrate the performance of the optimal stochastic power allocation. A distributed algorithm for the decentralized solution of the stochastic power allocation problem is discussed. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005
On the minimum number of wavelengths in multicast trees in WDM networks
Authors: Wan Yingyu , Liang Weifa
Published: December 2004

We consider the problem of minimizing the number of wavelengths needed to connect a given multicast set in a multihop WDM optical network. This problem was introduced and studied by Li et al. (Networks, 35(4), 260–265, 2000) who showed that it is NP‐complete. They also presented an approximation algorithm for which they claimed an approximation ratio ofc(1 + 2 log Δ), wherecis the maximum number of connected components in the subgraph induced by any wavelength and Δ is the maximum number of nodes in any connected component induced by any wavelength. In this article we present an example demonstrating that their claim cannot be correct—the approximation ratio is Ω(n), even though the subgraph induced by every wavelength is connected, wherenis the number of nodes in the network. In fact, we show that the problem cannot be approximated withinO(2) unlessNP⊆DTIME(npoly log n) for any constant ε > 0, wheremis the number of edges in the network. We complement this hardness result by presenting a polynomial–time algorithm with an approximation ratio of (1 + ln 3 + 2 log Δ) when the subgraph induced by every wavelength is connected, and an approximation ratio of$O(\sqrt{(n \, {\rm log} \, \Delta)/{\rm opt})}$in the general case, whereoptis the number of wavelengths used in an optimal solution and 1 ≤opt≤n− 1. © 2004 Wiley Periodicals, Inc. NETWORKS, Vol. 45(1), 42–48 2005
Optimization of double‐layer absorbers on constrained sound absorption system by using genetic algorithm
Authors: Chang Ying‐Chun , Yeh Long‐Jyi , Chiu Min‐Chie
Published: December 2004

As investigated by the Occupational Safety and Health Act (OSHA) in 1970, noise is highly responsible for the psychological and physiological ills to workers. Therefore, the noise control for an enclosed system with high echo effect becomes essential. Besides, the thickness of adopted sound absorber is occasionally constrained for maintenance, the interest in minimizing the noise under space constraint is then arising. In this paper, the shape optimization of double‐layer absorber together with genetic algorithm (GA) is presented. Before optimization, one example is tested and compared with the experimental data for accuracy check of mathematical model. Thereafter, a simple optimal program in dealing with pure tone noise of 350 Hz has been pre‐run to verify the correctness of genetic algorithm before the design in full band noise being performed. Results show that both the accuracy of mathematical model and the correctness of GA method are acceptable. Consequently, this study may provide a novel scheme with GA in solving the shape optimization of sound absorber on the constrained sound absorption system. Copyright © 2004 John Wiley & Sons, Ltd.
Design of a composite beam using the failure probability‐safety factor method
Authors: Castillo E. , Mínguez R. , Ruiz‐Terán A. , Fernández‐Canteli A.
Published: December 2004

The paper shows the practical importance of the failure probability‐safety factor method for designing engineering works. The method provides an automatic design tool by optimizing an objective function subject to the standard geometric and code constraints, and two more sets of constraints, that guarantee some given safety factors and failure probability bounds, associated with a given set of failure modes. Since a direct solution of the optimization problem is not possible, the method proceeds as a sequence of three steps: (a) an optimal classical design, based on given safety factors, is done, (b) failure probabilities or bounds of all failure modes are calculated, and (c) safety factors bounds are adjusted. This implies a double safety check that leads to safer structures and designs less prone to wrong or unrealistic probability assumptions, and to excessively small (unsafe) or large (costly) safety factors. Finally, the actual global or combined probabilities of the different failure modes and their correlation are calculated using a Monte Carlo simulation. In addition, a sensitivity analysis is performed. To this end, the optimization problems are transformed into another equivalent ones, in which the data parameters are converted into artificial variables. In this way, some variables of the dual associated problems become the desired sensitivities. The method is illustrated by its application to the design of a composite beam. Copyright 2004 © John Wiley & Sons, Ltd.
Limiting aspects of contracting out in transitional countries: the case of Estonian prisons
Authors: Lember Veiko
Published: December 2004

Estonia, being one of the most diligent students of the neo‐liberal economic paradigm among the Central and Eastern European transitional countries, has declared that private organisations should be given the chance to operate public prisons. This article argues that in spite of the promising perspective of this idea, the transitional context mixed with the complex nature of incarceration services, sets serious limits for a successful application of the initiative. After identifying four key sources of limiting factors of contracting out, which concern political, legal, administrative and economic aspects, the article gives a brief overview of the development of the Estonian public administration and prison system. It is argued that although no political limits could be identified, there exists some legal and most importantly administrative and economic limits for contracting out prisons in Estonia. There is a need to understand that due to problems inherent in transitional countries such as a low administrative capacity and underdeveloped markets, the implementation of contracting out in cases of complex public services does not solve but transfer the essence of the problems. Copyright © 2004 John Wiley & Sons, Ltd.
Accounting and accountability: recent developments in government financial information systems
Authors: Torres Lourdes
Published: December 2004

In developed countries, governmental accounting is considered as an integral part and a successful aspect of public sector reforms. In developing countries, besides being a tool for government financial management modernisation, accounting is regarded as a weapon against fraud and waste in government. The aim of this article is to compare, taking the IPSAS No.1 as a benchmark, the information content of the financial statements submitted by the central governments of Anglo‐Saxon, Nordic, European Continental and Mercosur zone countries. The results give us a point of reference as to where the central governmental accounting of each country studied lies in the ‘spectrum’ from cash to full accrual accounting and to what extent the IPSASs are able to fit into diverse public administration styles in order to improve the transparency, accountability and reliability of the financial information disclosed. Copyright © 2004 John Wiley & Sons, Ltd.
The transformation of the postal services of Trinidad and Tobago
Authors: Baptiste Roland G.
Published: December 2004

This study examines the change management aspect of the corporatisation of the Trinidad and Tobago Post Office. Interviews were conducted with key actors and the major unclassified documents were examined. An analysis of the sequence of events revealed a model of change management, but there is no evidence that the actors in the process explicitly developed it. Its competent application may explain the low level of opposition to the corporatisation of the Post Office and its success to this point. It is suggested that the model may be used to guide researchers and administrators in the future. Copyright © 2004 John Wiley & Sons, Ltd.
Electrical conductivity and electromagnetic interference shielding effectiveness of polyaniline–ethylene vinyl acetate composites
Authors: Das Narayan Chandra , Yamazaki Shinichi , Hikosaka Masamichi , Chaki Tapan Kumar , Khastgir Dipak , Chakraborty Ajay
Published: December 2004

Electrical conductivity and electromagnetic interference (EMI) shielding effectiveness at microwave (200–2000 MHz) and X‐band (8–12 GHz) frequency range of polyaniline (PAni) composites were studied. It has been observed that EMI shielding of conductive polyaniline (PAni)–ethylene vinyl acetate composites increases with the increase in the loading levels of the conductive polymer doped with dodecylbenzene sulfonic acid. The result indicates that the composites having higher PAni loading (>23%) can be used for EMI shielding materials and those with lower PAni loading can be used for the dissipation of electrostatic charge. Copyright © 2004 Society of Chemical Industry
Mechanical properties of esterified tapioca starch–LDPE blends using LDPE‐co‐glycidyl methacrylate as compatibilizer
Authors: Sailaja RRN
Published: December 2004

Studies on the mechanical properties of acetylated and phthalated starch blends with low density polyethylene (LDPE) were performed with and without LDPE‐co‐glycidyl methacrylate copolymer as compatibilizer. Impact and tensile properties of the blend specimens were measured following standard ASTM methods. Thermogravimetric analysis of esterified starches and of the blends were also conducted. Scanning electron microscopy was used to analyze the fractured and unfractured blends. Results indicate a significant improvement in the mechanical properties by starch esterification, which is further enhanced by the addition of the compatibilizer. Copyright © 2004 Society of Chemical Industry
Compatibility of reactively compatibilized polyamide 11 (nylon 11)/polyethylene (PE) alloys
Authors: Hu Guosheng , Wang Biaobing , Zhou Xiumiao
Published: December 2004

The compatibility of nylon 11/polyethylene (PE) alloys on addition of reactive maleated ethylene‐propylene‐diene copolymer (EPDM‐graft‐MAH) was investigated by differential scanning calorimetry, morphological observations and rheology. The decrease in the differential volume of the melting temperature of nylon 11 and PE with increasing compatibilizer suggests that the addition of EPDM‐graft‐MAH affects the crystalline behavior of nylon 11 and PE. The decreased particle size of the dispersed phase also confirmed the improvement in the compatibility. The rheological behavior revealed that the addition of the compatibilizer enhanced the apparent viscosity of the melting blends, which resulted from the increasing interaction between the chains due to the improvement in compatibility of nylon 11 and PE. Copyright © 2004 Society of Chemical Industry
Synthesis and properties of novel aromatic poly(ester–amide)s derived from 1,5‐bis(3‐aminobenzoyloxy)naphthalene and aromatic dicarboxylic acids
Authors: Hsiao Sheng‐Huei , Leu Wen‐Tsuen
Published: December 2004

A new naphthalene‐ring‐containing bis(ester–amine), 1,5‐bis(3‐aminobenzoyloxy)naphthalene, was prepared from the condensation of 1,5‐dihydroxynaphthalene with 3‐nitrobenzoyl chloride followed by catalytic hydrogenation. A series of novel naphthalene‐containing poly(ester–amide)s was synthesized by direct phosphorylation polyamidation from this bis(ester–amine) with various aromatic dicarboxylic acids. The polymers were produced in high yields and had moderate inherent viscosities of 0.47–0.81 dL g−1. The poly(ester–amide) derived from terephthalic acid was semicrystalline and showed less solubility. Other polymers derived from less rigid and symmetrical diacids were amorphous and readily soluble in most polar organic solvents and could be solution‐cast into transparent, flexible and tough films with good mechanical properties. The amorphous poly(ester–amide)s displayed well‐defined glass transition temperatures of between 179 and 225 °C from differential scanning calorimetry and softening temperatures of between 178 and 211 °C from thermomechanical analysis. These poly(ester–amide)s did not show significant decomposition below 400 °C in nitrogen or air. Copyright © 2004 Society of Chemical Industry
Copolymers of N‐isopropylacrylamide, HEMA‐lactate and acrylic acid with time‐dependent lower critical solution temperature as a bioresorbable carrier
Authors: Lee Bae Hoon , Vernon Brent
Published: December 2004

Copolymers of N‐isopropylacrylamide (NIPAAm), 2‐hydroxyethyl methacryl lactate (HEMA‐lactate) and acrylic acid (AAc) were prepared, with varying mole ratios of monomers, to develop a bioresorbable in‐situ‐gelling material with a time‐dependent lower critical solution temperature (LCST). The synthesized copolymers were characterized by nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry. In 0.1 M phosphate‐buffered saline solution of pH 7.4, these copolymers had an LCST below body temperature. The LCST decreased as the HEMA‐lactate content of the copolymers was increased. Furthermore, in these conditions, the LCST of the copolymers exhibited time‐dependent properties, due to hydrolysis of the HEMA‐lactate. As the HEMA‐lactate hydrolyzed, the copolymers became more hydrophilic, thereby leading to an increase in LCST. This hydrophilicity caused copolymers of approximately 6 mol% of AAc to exhibit an LCST above body temperature after hydrolysis. In neutral solution, copolymers with varying mol% of AAc saw their LCST rise above 37 °C within one to ten days, depending upon the HEMA‐lactate/NIPAAm ratio, due to the complete hydrolysis of the HEMA‐lactate. The above properties indicate that these copolymers would be useful for drug delivery because their variable LCST makes them bioresorbable. Copyright © 2004 Society of Chemical Industry
Morphology, thermal and mechanical properties of nylon 12/organoclay nanocomposites prepared by melt compounding
Authors: Phang In Yee , Liu Tianxi , Mohamed Ashiq , Pramoda Kumari Pallathadka , Chen Ling , Shen Lu , Chow Shue Yin , He Chaobin , Lu Xuehong , Hu Xiao
Published: December 2004

Nylon 12 (PA12) nanocomposites with different organoclay loadings were successfully prepared by melt compounding. X‐ray diffraction indicated the dominance of the exfoliated clay morphology throughout the matrix after mixing in a Brabender twin‐screw extruder, in accordance with transmission electron microscopy observations. Thermogravimetric analysis showed that the thermal stability of the PA12 matrix was improved by about 20 °C on incorporation of only 5 wt% clay. Tensile and nanoindentation tests indicated that the elastic modulus and the hardness steadily increased by about 52 % and 67 %, respectively, with a clay concentration up to 5 wt%, while improvements in tensile strength were limited. Impact strength decreased linearly by about 25 % as the clay loading increased (up to 5 wt%), indicating an embrittlement due to clay addition, as evidenced by SEM observation on the fracture surfaces. The embrittling effect may be due to the weak interfacial adhesion between the clay platelets and the polymer matrix. Copyright © 2004 Society of Chemical Industry
Gas barrier properties of poly(ε‐caprolactone)/clay nanocomposites: Influence of the morphology and polymer/clay interactions
Authors: Gain O. , Espuche E. , Pollet E. , Alexandre M. , Dubois Ph.
Published: December 2004

Poly(ε‐caprolactone)/montmorillonite nanocomposites were prepared maintaining a constant inorganic content with three means: melt blending of poly(ε‐caprolactone) with natural or organomodified clays, in situ polymerization of ε‐caprolactone in the presence of organomodified clays, and initiation of ε‐caprolactone polymerization from the silicate layer with appropriate organomodified montmorillonites and activator. In this last case, the polymer chains were grafted to the silicate layers and it was possible to tune up the grafting density. The presence of clays did not modify the polymer crystallinity. It was shown that the in situ polymerization process from the clay surface improved the clay dispersion. The gas barrier properties of the different composite systems were discussed both as a function of the clay dispersion and of the matrix/clay interactions. The highest barrier properties were obtained for an exfoliated morphology and the highest grafting density. Similar evolution of the permeability and the diffusion coefficients was observed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 205–214, 2005
Effect of cooling rate and plastic deformation under heat treatment on the structure of Sn–5wt% Bi alloy samples
Authors: Khalifa B. A. , Nagy M. R. , Afify R.
Published: December 2004

The effect of plastic deformation on the microstructure of heat treated superplastic alloy samples (Sn–5wt% Bi) prepared at two different rates of cooling 1.77 × 10–3 K/s and 18.4 K/s, named as slowly cooled and quenched in liquid nitrogen samples, have been studied as a function of temperature in the range of 308–388 K. The work hardening parameters for the two alloy samples were found to be dependent on both temperature and cooling rate. These parameters indicate the transition temperature at 328 K. The slowly cooled samples are much harder than those quenched in liquid nitrogen. This is explained by precipitation of Bi‐atoms which segregate to form a non‐coherent cubic α‐phase in the slowly cooled samples. The activation energy for fracture of the Sn–5wt% Bi alloy is divided into three stages with values of 19.2 ± 1.6, 18.7 ± 1.4 and 10.9 ± 0.81 kJ/mol and 15.6 ± 1.9, 14.6 ± 1.8 and 7.9 ± 1.1 kJ/mol for the slowly cooled and quenched alloy samples, respectively. The lattice parameters (a, c), the ratio (c/a) and the residual lattice strains (Δa/a, Δc/c) are found to be dependent on the test temperature and the rate of cooling with either maximum or minimum values at the transition temperature. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of NH+: An ab initio study
Authors: Amero José M. , Vázquez Gabriel J.
Published: December 2004

We report ab initio self‐consistent field MRSD‐CI electronic structure calculations of the NH+ cation. A basis set of DZ + POL quality augmented with Rydberg and bond functions was employed together with an extensive treatment of electron correlation. More than 50 electronic states of NH+ are reported, including doublets, quartets, and sextets. Leading configurations, vertical ionization energies of NH, vertical excitation energies of NH+, and potential energy curves are reported. Spectroscopic properties calculated for the known bound electronic states of NH+ are found in good agreement with experiment. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Comparative study of kinetics and reactivity indices of free radical polymerization reactions
Authors: Van Cauter K. , Hemelsoet K. , Van Speybroeck V. , Reyniers M. F. , Waroquier M.
Published: December 2004

Density functional theory calculations are used to determine the kinetics and reactivity indices of the first propagation steps of the polyethylene and poly(vinyl chloride) polymerization. Transition state theory is applied to evaluate the rate coefficient from the microscopically determined energies and partition functions. A comparison with the experimental Arrhenius plots validates the level of theory. The ability of reactivity indices to predict certain aspects of the studied propagation reactions is tested. Global softnesses of the reactants give an indication of the relative energy barriers of subsequent monomer additions. The correlation between energy and hardness profiles along the reaction path confirm the principle of maximum hardness. Local indices predict the regioselectivity of the attack of the growing radical to vinyl chloride. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Ab initio EPR study of S and Se defects in alkali halides
Authors: Stevens F. , Vrielinck H. , Callens F. , Pauwels E. , Van Speybroeck V. , Waroquier M.
Published: December 2004

Calculations using density functional theory are performed to study the electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) properties of S and Se impurities in alkali halide lattices. Cluster in vacuo models are used to describe the defect and the lattice surroundings. The trivacancy defect model proposed in the literature is able to reproduce both the experimental principal values and directions of the g tensor for S and Se defects doped in alkali halides. The alternative monovacancy model gives rise to important discrepancies with experiment and can be discarded. For the KCl lattice, the hyperfine tensors of the S and Se molecular ions also agree well with the available experimental data, giving further evidence to the trivacancy model. In addition, for NaCl:S and KCl:S computational results for the 23Na and 35Cl superhyperfine and quadrupole tensors are compared with experimental ENDOR parameters. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The analysis of high explosives by liquid chromatography/electrospray ionization mass spectrometry: multiplexed detection of negative ion adducts
Authors: Mathis John A. , McCord Bruce R.
Published: December 2004

The negative ion electrospray ionization mass spectrometric (ESI‐MS) detection of adducts of high explosives with chloride, formate, acetate, and nitrate was used to demonstrate the gas‐phase interaction of neutral explosives with these anions. The relative intensities of the adduct species were determined to compare the competitive formation of the selected high explosives and anions. The relative stability of the adduct species varies, yielding preferential formation of certain anionic adducts with different high explosives. To exploit this effect, an isocratic high‐performance liquid chromatography (HPLC)/ESI‐MS method was developed and used for the simultaneous analysis of high explosives using two different techniques for the addition of the anionic additives; pre‐ and post‐column. The results show that the pre‐column approach provides similar results with improved selectivity for specific explosives. By detecting characteristic adduct species for each explosive, this method provides a qualitative and quantitative approach for the analysis and identification of high explosives. Copyright © 2004 John Wiley & Sons, Ltd.
Application of DNA pooling to large studies of disease
Authors: Law Graham R. , Rollinson Sara , Feltbower Richard , Allan James M. , Morgan Gareth J. , Roman Eve
Published: December 2004

Large collections of individuals are required to investigate the association of commonly occurring genetic variation with disease. The laboratory assessment of one form of variation, single nucleotide polymorphisms, is costly in time and DNA. Robust statistical approaches are developed to allow the successful implementation of a recently described laboratory method for rapidly estimating allele frequency using pools of DNA. A substantial reduction in Type I error is demonstrated using simulation, through the incorporation of measurement error into confidence limits for a case–control study, illustrated on a case–control study of acute leukaemia in adults. A method for creating multiple sub‐pools is described which will allow large studies, such as the proposed U.K. Biobank, to take advantage of this method. Furthermore, a set‐based logistic regression is presented which allows the investigation of joint effects and interactions with other genes or environmental factors. Copyright © 2004 John Wiley & Sons, Ltd.