bluuebunny/crossref_metadata_2025 huggingface dataset:
Phonon dispersion in poly(L‐tryptophan)
Authors: Pande Sapna , Tandon Poonam , Gupta V.D.
Published: December 2003

The normal modes and their dispersions for poly(L‐tryptophan) (PLTR) in the α‐helical form have been obtained in a reduced zone scheme with Wilson's GF matrix method as modified by Higgs. Dynamic studies of the α form are of special significance as it is the predominant secondary structure for protein molecules. X‐ray and circular dichroism (CD) studies by Peggion et al. have confirmed the α‐helical conformation of PLTR. The side group of PLTR is more complicated than that of other natural polypeptides. It consists of both a pyrrole and a benzene ring along with a CH2 group. Optically active frequencies corresponding to the zone center and zone boundary are identified and discussed. Some of the characteristic features of the dispersion curves are repulsion accompanied by an exchange of character and von Hove singularities. The heat capacity has been calculated via densities of state with Debye's equation in the temperature range of 220–390 K and has been compared with experimental measurements. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 316–332, 2004
Influence of additives on the crystal structure and melting behavior of poly(ethylene‐2,6‐naphthalene dicarboxylate)
Authors: Gao Xia , Liu Ruigang , Yu Yin , Jin Manna , Bu Haishan
Published: December 2003

The influence of additives on the crystal modification and melting behavior of poly(ethylene‐2,6‐naphthalene dicarboxylate) (PEN) was investigated with wide‐angle X‐ray diffraction and differential scanning calorimetry (DSC). The addition of a nucleating promoter, Ceraflour 993, had no effect on the crystal modification and melting behavior of PEN crystallized under all chosen experimental conditions. However, the addition of a nucleating agent, sodium benzoate (SB), did affect the crystal modification and melting behavior of PEN when PEN/SB was crystallized at a higher temperature, but not at a lower temperature. A mixture of α and β modifications of PEN was obtained, and an overlapped dual melting peak was observed in DSC curves when PEN was crystallized at a higher temperature in the presence of SB, instead of a single crystal form and a single melting peak for the crystallization of pure PEN. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 296–301, 2004
Structural changes of silver polymer electrolytes: Comparison between poly(2‐ethyl‐2‐oxazoline) and poly(N‐vinyl pyrrolidone) complexes with silver salt
Authors: Hak Kim Jong , Ryul Min Byoung , Kon Kim Chang , Won Jongok , Soo Kang Yong
Published: December 2003

The difference between the polymer matrices of poly(2‐ethyl‐2‐oxazoline) (POZ) and poly(N‐vinyl pyrrolidone) (PVP) does not have a significant effect on the facilitated propylene transport and propylene solubility in 1:1 polymer/silver salt complex membranes, according to our previous work. In this article, its origin is investigated in terms of both microstructures of silver polymer electrolytes and the coordinative interaction of silver ion with polymer and with the counteranion. Initially different microstructures of POZ and PVP become similar to each other upon dissolving a large amount of silver salt, as evidenced by propane transport properties, specific volume, and Bragg d‐spacing. The dissolution of the silver salt in the polymer solvent strongly depends on the coordinative interaction between silver ion and carbonyl oxygen of POZ and PVP. Thus, the structural similarity upon dissolving silver salts in POZ and PVP is primarily determined by the coordinative interaction between silver ion and carbonyl oxygen, which was confirmed by theoretical structure calculation based on density functional theory and by IR and Raman spectroscopy. Therefore, facilitated olefin transport for silver polymer electrolyte membranes does not strongly depend on the polymeric matrix at high silver concentrations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 232–237, 2004
Polymorphism in nylon‐11/montmorillonite nanocomposite
Authors: Zhang Guosheng , Li Yongjin , Yan Deyue
Published: December 2003

The polymorphism behavior in nylon‐11/montmorillonite (MMT) nanocomposite was investigated by wide‐angle X‐ray diffraction (WAXD) and variable‐temperature infrared spectroscopy. The results of WAXD and IR confirmed the presence of the γ‐crystalline form of nylon‐11, which is induced and stabilized by MMT. However, the hydrogen bond in the nanocomposite and its temperature dependence also exhibited some differences from neat nylon‐11. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 253–259, 2004
Syntheses and permselectivity properties of polysulfones based on bisphenol A and 1, 1 bi‐2 naphthol
Authors: Lagunas‐Fuentes C. , Ruiz‐Treviño F. A.
Published: December 2003

Polysulfone copolymers based on mixtures of bisphenol A, BPA, and 1,1 bi‐2 naphthol, BN, diols have been synthesized and their gas permeability coefficients and selectivity separation factors for O2/N2 and CO2/CH4, at 5 atm and 35 °C, have been measured in a standard permeation cell. The polysulfone copolymers can form flexible thin films suitable for gas separation membranes. The gas selectivity for O2/N2 measured for the polysulfone copolymers synthesized with 50 and 70 mol % of BN, with the rest being BPA, in the initial mixture of diols are 6.4 and 6.8, respectively. The corresponding gas permeability coefficients for O2 are 1.24 and 1.09 Barrers. Compared to the corresponding selectivity and permeability balance reported for polysulfones based on pure BPA, BPA–PSF, the copolymers show a balance that moves in the direction of higher selectivity with small losses in the permeability of the fastest gas. From the glass transition temperature determinations, it is observed that the incorporation of BN in the repeating unit of BPA–PSF inhibits large‐scale segmental motions that are reflected in reductions in the diffusivity coefficients for all gases. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 226–231, 2004
Synthesis, structure, and properties of polyimide and polyurethane‐urea‐imide copolymers
Authors: Liu Jin , Li Zhen , Luo Xiaolie , Ma Dezhu
Published: December 2003

Several, novel polyimide–polyurethane‐urea‐imide (PI‐PUI) copolymers with different polyimide (PI) contents were prepared by an in situ interpenetrating reaction between polyurethane‐urea‐imide (PUI) precursor and poly(amide acid). Changing the ratio of the PUI precursor and poly(amide acid) resulted in a change of the properties of the PI‐PUI copolymers from plastic to elastomer. Fourier transform infrared spectra revealed the characteristic absorption bands of PI‐PUI copolymers; differential scanning calorimetry (DSC) analyses revealed that the glass‐transition temperature of the soft‐segment‐rich phase decreased as the PI content increased in PI‐PUIs, meaning that the soft segments (i.e., PEG) were more incompatible and had better crystallizability with a high‐PI‐segment content in PI‐PUI. Wide‐angle X‐ray diffraction curves exhibited more ordered structure within the disordered PI‐PUI copolymer's state with an increasing PI content, which further agreed with the DSC results. Scanning electron micrographs clearly showed that the molecular chains in PI‐PUI with a high‐PI‐content packed, ordered lamellar structure. Thermogravimetric curves indicated that the heat resistance of PI‐PUI was better than pure PUI. The introduction of the PI component into PUI by an in situ interpenetrating reaction method is an effective way to improve the thermal stability and solvent resistance of PUI. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 216–225, 2004
Including 4‐Hydroxyquinoline Derivatives into β‐Cyclodextrin to Form Complexes Affects Their Antioxidative Effect on Free‐Radical‐Induced Hemolysis of Human Erythrocytes
Authors: Liu Zai‐Qun , Luo Xu‐Yang , Liu Guo‐Zong , Liu Qing‐Wen
Published: December 2003

A series of β‐cyclodextrin inclusion complexes of 4‐hydroxyquinoline derivatives was designed and their activities on free‐radical‐induced hemolysis were studied. The hemolysis of human erythrocytes was initiated by 2,2′‐azobis(2‐amidinopropane hydrochloride) (AAPH). A novel distributive status was designed: 7‐chloro‐4‐hydroxyquinoline‐3‐carboxylic acid (CA), 7‐fluoro‐4‐hydroxyquinoline‐3‐carboxylic acid (FA), 7‐chloro‐4‐hydroxyquinoline (CQ) and 7‐fluoro‐4‐hydroxy quinoline (FQ) were included into β‐cyclodextrin to form host‐guest complexes, CACD, FACD, CQCD and FQCD, respectively. The hemolysis process was expressed mathematically by Boltzmann equation. Three complexes acted as concentration‐dependent antioxidants, and the order of concentration‐sensitivity was CQCD>FACD>FQCD. CACD did not show activity. The order of 50% inhibitory concentration (IC50) was FQCD<FACD<CQCD, which was different from that dissolved in dimethyl sulfoxide (DMSO) remarkably. FQCD may be a candidate for a novel antitumor drug.
Molecular Modeling of Interaction of the Vasopressin Analogs with Vasopressin and Oxytocin Receptors
Authors: Ślusarz Rafał , Ślusarz Magdalena J. , Kaźmierkiewicz Rajmund , Lammek Bernard
Published: December 2003

In this study the interaction of seven new analogs of arginine vasopressin (AVP) substituted in position 2 or 3 with 1‐aminocyclohexanecarboxylic acid (Acc) with the vasopressin (VP) and oxytocin (OT) receptors (V1aR, V2R and OTR) is described. All peptides were synthesized and tested in bioassays for pressor and antidiuretic activities. Also their uterotonic activity in vitro has been measured. This work was aimed at checking the applicability of computational methods for predicting receptor‐ligand interactions and makes a good basis for selecting the receptor amino acid residues involved in ligand binding. The results of this study suggest preferred geometries of new, potentially active AVP analogs.
Study of interfacial chemistry on direct curing adhesion between Ni–P plating and rubber using 1,3,5‐triazine‐2,4,6‐trithiol monosodium salt
Authors: Hirahara Hidetoshi , Aisawa Sumio , Mori Kunio , Narita Eiichi , Oishi Yoshiyuki
Published: December 2003

Direct adhesion between Ni–P‐plated iron and acrylonitrile–butadiene rubber, hydrogenated acrylonitrile–butadiene rubber and ethylene–propylene rubber was successful using 1,3,5‐triazine‐2,4,6‐trithiol monosodium salt (TTN) without any adhesive. Peel strength in the adherends was influenced by the amount of TTN employed. The interfacial structure between Ni–P‐plated iron and curing rubbers has been investigated with x‐ray microanalysis, x‐ray photoelectron spectroscopy and scanning electron microscopy. The TTN derivatives gathered locally at the interface between the Ni–P‐plated iron and curing rubber adherends. The TTN layer located near the interface is referred to as a reinforcement layer. This layer was in general ∼70 nm thick and consisted of composites of the Ni salt of TTN. The TTN is thought to work as a binder that bonds between Ni–P‐plated iron and rubber chains. The single bonds between both Ni–P‐plated iron and rubber TTN was confirmed from Kraus plots and model experiments using TTN. Copyright © 2003 John Wiley & Sons, Ltd.
Si 2p XPS spectrum of the hydrogen‐terminated (100) surface of device‐quality silicon
Authors: Cerofolini G. F. , Galati C. , Renna L.
Published: December 2003

An experimental study of the Si 2p XPS spectrum at different take‐off angles of atomically flat, hydrogen‐terminated 1 × 1 Si(100) is reported. The observed spectrum can be described accurately by considering three additional contributions to the spectrum of elemental silicon. Each contribution is attributed to a chemical state of silicon on the basis of its chemical shift with respect to elemental silicon and the depth of the region where it was originated. Copyright © 2003 John Wiley & Sons, Ltd.
Investigation of glow discharge plasma for surface modification of polypropylene
Authors: Yousefi H. R. , Ghoranneviss M. , Tehrani A. R. , Khamseh S.
Published: December 2003

Material surface properties of polymers, plastics, ceramics and textiles can be modified by atmospheric or low‐pressure glow discharge plasma. The aim of the present work is to study the surface modification of biaxially oriented polypropylene (BOPP) film in order to improve its hydrophilic and wetting properties. In this article we used low‐pressure, low‐temperature oxygen plasma for the surface treatment of BOPP. Scanning electron microscopy indicates that plasma treatment causes mainly physical changes by creating microcraters and roughness on the surface and increasing surface friction. Attenuated total reflectance infrared spectra show oxygen‐containing groups such as OH at 3513 cm−1 and CO at 1695 cm−1. Microscopic investigations of water droplets on BOPP (treated, untreated) show that the interfacial adhesion of treated surfaces is increased. Copyright © 2003 John Wiley & Sons, Ltd.
Electropolymerization of DBSA‐doped polypyrrole films on PTFE via an electroless copper interlayer
Authors: Prissanaroon W. , Brack N. , Pigram P. J. , Liesegang J.
Published: December 2003

We report on the electroless deposition of thin films of copper on poly(tetrafluoroethylene) (PTFE) and their use as substrates for electropolymerization of polypyrrole. Argon plasma‐treated PTFE films were modified by silanization using N‐[3(trimethoxysilyl)propyl]diethylenetriamine (TMS). The TMS‐modified PTFE films were subsequently activated by PdCl2 for the electroless deposition of copper. The omission of the commonly used SnCl2 sensitization step represents a significant process enhancement with environmental and cost benefits. The surface composition of the substrate (before and after surface treatments) and overlayer films was studied using high‐resolution x‐ray photoelectron spectroscopy. A combination of time‐of‐flight secondary ion mass spectrometry and water contact‐angle measurements was also used to study the PTFE surface after argon plasma treatment. The Cu/PTFE films were used as substrates for subsequent pyrrole electropolymerization in aqueous dodecylbenzene sulphonic acid (DBSA) solution. The DBSA‐doped polypyrrole overlayers were successfully deposited on the Cu/PTFE surface using a constant applied potential of 1.5 V. The resulting material exhibited a doping level of 39%, determined using chemical component analysis of the N 1s photoelectron peak. Copyright © 2003 John Wiley & Sons, Ltd.
Are measured values of the Auger parameter always independent of charging effects?
Authors: Oswald S. , González‐Elipe A. R. , Reiche R. , Espinos J. P. , Martín A.
Published: December 2003

In x‐ray photoelectron spectroscopy (XPS) the Auger parameter is often used to study the electronic properties of elements, particularly in insulator materials, because this parameter is assumed to be independent of charging effects. In this paper we report on subtle differences in sample structure and experimental conditions for which the sample potential may not remain constant during the measurements for some spectrometers or experimental arrangements; for such conditions the Auger parameter is not independent of charging. We compare a series of measurements with insulating plate substrates of Al2O3 on which different amounts of SnO2 and Au were deposited. X‐ray photoelectron spectra were collected for different conditions of the sample that was placed either grounded or left floating on a metallic sample holder during measurement. It is found that the Auger parameter is independent of the experimental conditions for Au but substantial differences were found for deposited SnO2. Surprisingly, measurement artifacts due to charging appeared in the Auger parameter for Sn when the sample holder was grounded but not when it was left floating. In the grounded samples differences up to 0.6 eV in the Auger parameter for Sn were found with respect to the actual value of this parameter measured with substrates where charging effects were not significant. Because no differences in peak broadening have been observed under different measurement conditions, it has been assumed that the shift was not caused by a conventional differential charging phenomenon. Considering the different response of the substrate and the deposited layer on stabilizing the charge when the sample is grounded, we have worked out a possible explanation to account for the observed artifacts. Instrumental specifications should be optimized very carefully, especially if (as here) relatively high charging shifts point to a non‐optimum self‐biasing of the surface potential at the insulating samples. Copyright © 2003 John Wiley & Sons, Ltd.
Study of the electronic and atomic structure of thermally treated SrTiO3(110) surfaces
Authors: Gunhold A. , Beuermann L. , Gömann K. , Borchardt G. , Kempter V. , Maus‐Friedrichs W. , Piskunov S. , Kotomin E. A. , Dorfman S.
Published: December 2003

The electronic structure of heated SrTiO3(110) surfaces was investigated with metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy (He(I)). Scanning tunnelling microscopy and atomic force microscopy (AFM) were used to study the topology of the surface. The crystals were heated up to 1000°C under reducing conditions in ultrahigh vacuum or under oxidizing conditions in synthetic air for 1 h, respectively. Under both conditions microfacetting of the surface is observed. The experimental results are compared with ab initio Hartree–Fock calculations, also presented here, carried out for both ideal and reconstructed SrTiO3(110) surfaces. The results give direct evidence for Ti termination of the faceted TiO2 rows. Copyright © 2003 John Wiley & Sons, Ltd.
Investigation into the surface selective oxidation of dual‐phase steels by XPS, SAM and SIMS
Authors: Vanden Eynde X. , Servais J. P. , Lamberigts M.
Published: December 2003

Surface selective oxides created during continuous annealing (MnO, SiO2, etc.) can have a deleterious effect on coating adhesion after hot‐dip galvanizing. Earlier research works have made it clear that increasing the annealing atmosphere oxidizing potential can alleviate the problem by reducing external surface selective oxidation. In the present study, increasing the water vapour content of the nitrogen–hydrogen protective gas mixture was used to raise its oxidizing potential. The technique was applied to a classical dual‐phase steel (0.15% C, 1.5% Mn, 0.45% Si, 0.05% Al…) that was annealed for 60 s at 800–810°C in protective atmospheres of nitrogen and 5% hydrogen with water vapour contents ranging from 10 to 6000 ppm.

Post‐annealing surfaces were characterized by x‐ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS) and scanning Auger microscopy (SAM). In situ XPS analyses were carried out right after simulation annealing in the preparation chamber connected to the spectrometer, never returning the specimens to air. This made it possible to identify in a reliable way the elements that segregated to the surface during the treatment, and to determine their corresponding oxidation states. On the other hand, the high sensitivity of SIMS was taken advantage of to assess oxide in‐depth concentration profiles (SiO2, Al2O3, FeO) as a function of the annealing conditions, and SAM was used to characterize the corresponding oxide particle morphology.

External selective oxidation was thus shown to decrease with increasing water vapour contents in the atmosphere (from 80 to 6000 ppm), whereas internal oxidation increases drastically to ∼4 μm below the free surface. At 10 ppm of H2O the oxygen partial pressure is very low and the external selective oxidation results in a thin, but almost complete, coverage of the steel surface. Consequently, metallic iron cannot be observed at the surface, thus hampering hot‐dip galvanizability, unless the water vapour content is raised to 6000 ppm. Various surface morphologies were observed and discussed.

In the authors' opinion, basic investigations of this type are an indispensable first step to improving the response of highly alloyed steels (dual‐phase, TRIP) to hot‐dip galvanizing. Copyright © 2003 John Wiley & Sons, Ltd.
CONSIT: a fully automated conditioned program slicer
Authors: Fox Chris , Danicic Sebastian , Harman Mark , Hierons Robert M.
Published: December 2003

Conditioned slicing is a source code extraction technique. The extraction is performed with respect to a slicing criterion which contains a set of variables and conditions of interest. Conditioned slicing removes the parts of the original program which cannot affect the variables at the point of interest, when the conditions are satisfied. This produces a conditioned slice, which preserves the behaviour of the original with respect to the slicing criterion.

Conditioned slicing has applications in source code comprehension, reuse, restructuring and testing. Unfortunately, implementation is not straightforward because the full exploitation of conditions requires the combination of symbolic execution, theorem proving and traditional static slicing. Hitherto, this difficultly has hindered development of fully automated conditioning slicing tools.

This paper describes the first fully automated conditioned slicing system, CONSIT, detailing the theory that underlies it, its architecture and the way it combines symbolic execution, theorem proving and slicing technologies. The use of CONSIT is illustrated with respect to the applications of testing and comprehension. Copyright © 2003 John Wiley & Sons, Ltd.
Influence of Delayed Harvest Time on Physico‐chemical Properties of Sweetpotato Starch
Authors: Toyama Jun , Ishiguro Koji , Noda Takahiro , Kumagai Toru , Yamakawa Osamu
Published: December 2003

Eight varieties of sweetpotato [Ipomoea batatas (L.) Lam] were transplanted in June, and harvested in October, November, December 1999 and January 2000. Starch content and starch properties of the tuberous roots were compared on delaying the harvest date. The shoot tops got blighted in early December and chilling injury rate of roots (average of eight varieties) increased up to 76.7% in January with decrease in temperature. Starch contents in October (24.0 g/100 g fresh weight, fw) and November (25.0 g/100 g fw) were almost the same, but the content decreased remarkably in December (21.2 g/100 g fw) and January (15.5 g/100 g fw). In December and January, the sucrose content of the roots had higher values. Hardness and leaked water percentage (LWP) of the starch gels remarkably increased from November to December (hardness: 76.4 to 112.3 g, LWP: 6.6 to 10.9%). On the contrary, the changes in amylose content and pasting properties of the starches were not consistent with decrease in temperature. This suggests that the effect of low temperature on these properties is insignificant after the growth period of sweetpotato. There were significant differences among the varieties in terms of starch retrogradation. The selection of varieties such as Kyushu 123 with the lowest percentage of retrogradation and Kyukei90142‐8 with the lowest chilling injury rate will help to lengthen the storage time in the field at least until December.
Effect of Cultivation Conditions on Retrogradation of Sweetpotato Starch
Authors: Ishiguro Koji , Noda Takahiro , Yamakawa Osamu
Published: December 2003

Sweetpotatoes were grown under four cultivation conditions, i. e. early planting and early harvesting (I, E‐E), standard (II, STD), early planting and late harvesting (III, E‐L), and late planting and late harvesting (IV, L‐L). Retrogradation of the starch isolated from fresh roots was estimated by the hardness and syneresis rate after two weeks of storage at 5 °C. A significant difference in retrogradation among the cultivation conditions and cultivars was observed. The starch tended to exhibit slower retrogradation in late harvesting, where the temperature was low. The differences in amylose content and the proportion of short unit‐chains (DP 9‐11) of amylopectin among cultivation conditions were also significant. Starch retrogradation was positively correlated with the proportion of chains with DP 12‐14 but negatively correlated with the proportion of DP 9‐11. Moreover, there was no significant correlation between amylose content and retrogradation. These results indicate that the main factor for retrogradation under any cultivation condition is the proportion of short unit‐chains of amylopectin. The best performance of sweetpotato starch as a food ingredient would be achieved by selecting both the proper cultivar and cultivation conditions.
Reliability of a model based on a short fishery statistics survey: application to the Northeast Atlantic monkfish fishery
Authors: Rocha Francisco , Gracia Joaquín , González Ángel F , Jardón Carlos M , Guerra Ángel
Published: December 2003

A model based on a short fishery statistics survey was applied to estimate catch and catch per unit effort (cpue) of the Galician monkfish (Lophius spp.) trawl fleet during 1998. In all, 35 interviews were conducted with fisheries personnel in ICES Divisions IXa, VIIIc, VIIId, and VIIIe (coastal offshore fishing grounds) and 44 in VIIb, VIIc, VIIj, and VIIk (Grand Sole fishing ground). Reliability of the model estimates was tested using: (i) registered fish market landings at 38 ports; (ii) landings data from sale invoices at six of these ports (93.8% of total landings of the species); (iii) 29 observers' trips made on board coastal offshore trawlers and the logbook of one Grand Sole trawler. Estimated mean total catch from the model was 5110 t (602 t coastal offshore, 4508 t in Grand Sole) and cpue values were 36.2 kg haul−1 vessel−1 coastal offshore and 104.4 kg haul−1 vessel−1 Grand Sole. Differences between the values of cpue estimated by the model and those determined directly in both fisheries were not significant. However, there were differences between the total catch estimated by the model and the total landings deduced from sale invoices and Galician fish market information.
Gene expression of periostin in the early stage of fracture healing detected by cDNA microarray analysis
Authors: Nakazawa Tetsuro , Nakajima Arata , Seki Naohiko , Okawa Akihiko , Kato Masaki , Moriya Hidesige , Amizuka Norio , Einhorn Thomas A. , Yamazaki Masashi
Published: December 2003

To comprehensively evaluate gene expression in the early stage of fracture healing, we used a cDNA microarray with 2304 cDNA clones derived from an oligo‐capped mouse embryo library. Closed mid‐diaphyseal fractures were created in mouse tibiae and expression profiles were analyzed 3 days after fracture. Six genes were up‐regulated in comparison to those in unfractured bones and these included three genes previously identified but never shown to be present in fractures, periostin, calumenin, and FHL‐1. Cloning of these genes has been completed but their expression pattern and function during fracture healing and bone formation remain to be elucidated. Up‐regulation of the six genes was reconfirmed by semi‐quantitative RT‐PCR analysis. Spatial and temporal expression of one of the newly identified fracture‐induced genes, periostin, was analyzed using in situ hybridization, because it displayed the highest up‐regulation ratio. A signal for periostin was detected in undifferentiated mesenchymal cells and immature preosteoblastic cells in the periosteal tissues between days 3 and 14 after fracture. Northern analysis showed that periostin gene expression rapidly increased by day 3, reached a peak on day 7, and declined by day 14. These findings suggest that periostin is a specific marker for preosteoblasts and may play an important role in periosteal callus formation during the early stage of fracture healing. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Monetary secrecy and selective disclosure: The emerging market case of Mexico's monetary reporting
Authors: Wilson Berry , Saunders Anthony
Published: December 2003

The International Monetary Fund (IMF) adopted a code of good conduct to increase the transparency of official operations in emerging markets, in part prompted by the 1994 peso and other emerging market crises. In the case of Mexico, its central bank increased monetary reporting from thrice a year to weekly monetary disclosures following the peso crisis. However, increasing evidence has established that emerging financial markets are strong form efficient with respect to public disclosures, implying substantial insider trading. This conclusion raises an important selective disclosure issue. If emerging market insiders can frontrun outside investors, asymmetric information costs increase, lessening the transactional and economic efficiency in the economy. This study's results suggest that the selective disclosure issue should be more widely discussed and addressed.
Agency theory and the House bank affair
Authors: Preece Dianna C , Mullineaux Donald J , Filbeck Greg , Dennis Steven A
Published: December 2003

In one of the worst political scandals of the 1990s, a large number of members of the U.S. House of Representatives wrote checks on nonexistent balances in what has become known as the House bank scandal. Agency theory tells us that the most entrenched members of the House should be more likely to consume excessive perquisites in the form of writing more bad checks. In this paper, we employ a Tobit model to test whether more entrenched members of the House engaged in excessive writing of bad checks. Our results support the agency‐theoretic interpretation and confirm that entrenched members were more likely to write a greater number of bad checks.
The role of calponin in the gene profile of metastatic cells: inhibition of metastatic cell motility by multiple calponin repeats
Authors: Lener Thomas , Burgstaller Gerald , Gimona Mario
Published: December 2003

Metastasis of diseased cells is the basic event leading to death in individuals with cancer. Establishment of metastasis requires that tumour cells migrate from the site of the primary tumour into the circulation system, escape from the vasculature and form secondary tumours at novel sites. These processes depend to a large degree on cytoskeletal remodeling. We show here that multiple copies of the short actin‐binding module CLIK23 from human or Caenorhabditis elegans calponin proteins effectively inhibit cell motility on two dimensional matrices and suppress soft agar colony formation of metastatic melanoma and adenocarcinoma cells of murine and human origin. Ectopic expression of CLIK23 modules for 30 days results in the formation of multinucleated cells. The repeat displays true modular behaviour, resulting in increased cytoskeletal effects in direct correlation with the increase in number of modules. Our results demonstrate that the role of calponin in the signature profile of metastasising cells is that of a mechanical stabiliser of the actin cytoskeleton, which interferes with actin turnover by binding at a unique interface along the actin filament.
Critical residues for RNA discrimination of the histone hairpin binding protein (HBP) investigated by the yeast three‐hybrid system
Authors: Jaeger Sophie , Eriani Gilbert , Martin Franck
Published: December 2003

The histone hairpin binding protein (HBP, also called SLBP, which stands for stem‐loop binding protein) binds specifically to a highly conserved hairpin structure located in the 3′ UTR of the cell‐cycle‐dependent histone mRNAs. HBP consists of a minimal central RNA binding domain (RBD) flanked by an N‐ and C‐terminal domain. The yeast three‐hybrid system has been used to investigate the critical residues of the human HBP involved in the binding of its target hairpin structure. By means of negative selections followed by positive selections, we isolated mutant HBP species. Our results indicate tight relationships between the RBD and the N‐ and C‐terminal domains.
Results and prospects of the yeast three‐hybrid system
Authors: Jaeger Sophie , Eriani Gilbert , Martin Franck
Published: December 2003

In 1996, a new method, termed the yeast three‐hybrid system, dedicated to selection of RNA binding proteins using a hybrid RNA molecule as bait was described. In this minireview, we summarize the results that have been obtained using this method. Indeed, ∼20 unknown proteins have been characterized so far. The three‐hybrid strategy has also been used as a tool to dissect RNA–protein interactions. The example of such a study on human histone HBP interaction with its target mRNA is described. Problems that can be encountered are addressed in a troubleshooting section. Especially, our results with tRNA binding proteins are discussed.
Cabinet Instability and the Accumulation of Experience: The French Fourth and Fifth Republics in Comparative Perspective
Authors: HUBER JOHN D. , MARTINEZ-GALLARDO CECILIA
Published: December 2003

Drawing on arguments about politics during the French Fourth Republic, the concept of cabinet instability is reconsidered. Rather than studying cabinet duration, the article examines the accumulation of experience by individual cabinet ministers. Two variables are measured in nineteen parliamentary democracies: portfolio experience the experience of cabinet ministers in the specific portfolios that they hold) and political experience (the experience of cabinet ministers in any significant portfolio). The results cast doubt on existing claims about cabinet government in the Fourth and Fifth Republics. They also uncover substantial cabinet turnover in majoritarian systems, suggesting that existing claims about stability in such systems may be overstated.
Minority Voices and Citizen Attitudes about Government Responsiveness in the American States: Do Social and Institutional Context Matter?
Authors: HERO RODNEY E. , TOLBERT CAROLINE J.
Published: December 2003

Previous research has shown that institutional factors, particularly ‘direct democracy’, along with racial context, shape policy outcomes in the fifty American states. But less is understood about the impact of such factors on attitudes towards government of racial and ethnic minorities. The passage of ballot initiatives targeting minority interests might be expected to have a negative effect on these groups. This study considers the impact of institutional and social context on attitudes about government responsiveness (external efficacy), drawing on pooled NES survey data from 1988–98 merged with state level data. Consistent with previous research, which was based on a single year, there is strong evidence that citizens in states with frequent exposure to direct democracy are more likely to perceive that government is responsive to their needs. At the same time, direct democracy did not have the hypothesized detrimental impact on racial and ethnic group attitudes towards government in general. State racial context also did not have a measurable impact on individual-level attitudes. Regardless of state environmental contexts, however, racial and ethnic minorities (with the exception of Latinos) reported less confidence in government than whites. The findings have broader implications, particularly given the growing racial and ethnic diversity and the ongoing politics of democratic inclusion in America.
ON $M$-STRUCTURE AND WEAKLY COMPACTLY GENERATED BANACH SPACES
Authors: Nieto Eduardo
Published: December 2003

It is well known that every non-reflexive $M$-ideal is weakly compactly generated (in short, WCG). We present a family of Banach spaces $\{V_{s}:0 \lt s \lt 1\}$ which are not WCG and such that every $V_{s}$ satisfies the inequality

$$ \|\f\|\geq\|\pi\f\|+s\|\f-\pi\f\|\quad\forall\f\in V_{s}^{\ast\ast\ast}, $$

where $\pi$ is the canonical projection from $V_{s}^{\ast\ast\ast}$ onto $V_{s}^{\ast}$. In particular, no $V_{s}$ can be renormed to be an $M$-ideal.

AMS 2000 Mathematics subject classification: Primary 46B20
RIGHT SEMIDEFINITE EIGENVALUE PROBLEMS
Authors: Binding Paul , Volkmer Hans
Published: December 2003

The relationships between various notions of completeness of eigenvectors and root vectors of the eigenvalue problem $Af=\lambda Bf$ are investigated. Here $A$ and $B$ are self-adjoint operators in Hilbert space with $B$ bounded and positive semidefinite, and with $A$ having compact resolvent.

AMS 2000 Mathematics subject classification: Primary 47A75. Secondary 34B24; 35P10
MULTIPLE POSITIVE SOLUTIONS AND BIFURCATION FOR AN EQUATION RELATED TO CHOQUARD’S EQUATION
Authors: Küpper Tassilo , Zhang Zhengjie , Xia Hongqiang
Published: December 2003

In this paper we study the existence of multiple positive solutions and the bifurcation problem for the following equation:

$$ -\Delta u+u=\biggl(\int_{\mathbb{R}^3}\frac{|u(y)|^2}{|x-y|}\,\mathrm{d}y\biggr)u+\mu f(x),\quad x\in\mathbb{R}^3, $$

where $f(x)\in H^{-1}(\mathbb{R}^3)$, $f(x)\geq0$, $f(x)\not\equiv0$. We show that there are positive constants $\mu^{*}$ and $\mu^{**}$ such that the above equation possesses at least two positive solutions for $\mu\in(0,\mu^{*})$, and no positive solution for $\mu>\mu^{**}$. Furthermore, we prove that $\mu=\mu^{*}$ is a bifurcation point for the equation under study.

AMS 2000 Mathematics subject classification: Primary 35J60; 35J70
POSITIVE SEMIDEFINITENESS OF DISCRETE QUADRATIC FUNCTIONALS
Authors: Bohner Martin , Došlý Ondřej , Kratz Werner
Published: December 2003

We consider symplectic difference systems, which contain as special cases linear Hamiltonian difference systems and Sturm–Liouville difference equations of any even order. An associated discrete quadratic functional is important in discrete variational analysis, and while its positive definiteness has been characterized and is well understood, a characterization of its positive semidefiniteness remained an open problem. In this paper we present the solution to this problem and offer necessary and sufficient conditions for such discrete quadratic functionals to be non-negative definite.

AMS 2000 Mathematics subject classification: Primary 39A12; 39A13. Secondary 34B24; 49K99
How does Trypanosoma equiperdum fit into the Trypanozoon group? A cluster analysis by RAPD and Multiplex-endonuclease genotyping approach
Authors: CLAES F. , AGBO E. C. , RADWANSKA M. , TE PAS M. F. W. , BALTZ T. , DE WAAL D. T. , GODDEERIS B. M. , CLAASSEN E. , BÜSCHER P.
Published: December 2003

The pathogenic trypanosomes Trypanosoma equiperdum, T. evansi as well as T. brucei are morphologically identical. In horses, these parasites are considered to cause respectively dourine, surra and nagana. Previous molecular attempts to differentiate these species were not successful for T. evansi and T. equiperdum; only T. b. brucei could be differentiated to a certain extent. In this study we analysed 10 T. equiperdum, 8 T. evansi and 4 T. b. brucei using Random Amplified Polymorphic DNA (RAPD) and multiplex-endonuclease fingerprinting, a modified AFLP technique. The results obtained confirm the homogeneity of the T. evansi group tested. The T. b. brucei clustered out in a heterogenous group. For T. equiperdum the situation is more complex: 8 out of 10 T. equiperdum clustered together with the T. evansi group, while 2 T. equiperdum strains were more related to T. b. brucei. Hence, 2 hypotheses can be formulated: (1) only 2 T. equiperdum strains are genuine T. equiperdum causing dourine; all other T. equiperdum strains actually are T. evansi causing surra or (2) T. equiperdum does not exist at all. In that case, the different clinical outcome of horse infections with T. evansi or T. b. brucei is primarily related to the host immune response.
Parasite specialization from a phylogenetic perspective: a new index of host specificity
Authors: POULIN R. , MOUILLOT D.
Published: December 2003

The host specificity of a parasite is not merely a function of how many host species it can exploit, but also of how closely related these host species are to each other. Here, a new index of host specificity is proposed, one that takes into account the average taxonomic or phylogenetic distance between pairs of host species used by a parasite. The index is derived from measures of taxonomic distinctness used in biodiversity studies. It is easy to compute and interpret, ranging from a minimum value of 1 when all host species are members of the same genus, to a maximum of 5, when all host species belong to different classes. The variance of this measure can also be computed, and provides additional information on the taxonomic or phylogenetic structure of the host assemblage. Using data on helminth parasites of Canadian freshwater fishes, we show that the new index, unlike the mere number of known host species, is independent of study effort i.e. the number of published records of a parasite. Although the index and the number of known hosts are not entirely independent statistically, each captures a different aspect of host specificity. For instance, although acanthocephalans infect significantly more host species than trematodes, cestodes or nematodes, there is no difference in the average index value among these 4 helminth taxa, suggesting that the average taxonomic distances between the host species of a parasite do not vary among these higher taxa. We recommend the use of our new index in future comparative studies of host specificity, in particular when the focus is on the evolutionary history of parasites and of their past colonizations of host lineages.
The asset portfolio composition of British life insurance firms, 1900–1965
Authors: BAKER MAE , COLLINS MICHAEL
Published: December 2003

This article examines the investment practices of life assurance firms within the United Kingdom, through an analysis of the asset holdings of the sector over the period 1900 to 1965. The data are drawn from the detailed annual returns to the Board of Trade. Aggregate, sectional and individual company data are used in the study. Major trends in investment practice are identified and analysed; and cross-sectional comparisons are made. The main emphasis is on the contribution of the life assurance sector towards provision of financial support to the British industrial sector. From the beginning of the period a significant proportion of life firms' investments was held in corporate securities, although over time the composition moved away from fixed-interest stock towards share holdings. The study highlights the great variation in investment practice across individual life assurance firms, with no strong evidence of convergence over time excepting investments in equity holdings.
Civil commotion and riot insurance in fascist Europe, 1922–1941
Authors: FELDMAN GERALD D.
Published: December 2003

Insurance for damage caused by public unrest became popular in post-1918 Central Europe and proved to be a profitable business, but one that became increasingly problematic because of the role of fascist regimes in promoting civil commotion. This article addresses some of the experiences of insurance companies, especially the Munich Reinsurance Company, when trying to manage policies covering political unrest and riot in Italy, Germany and Spain between 1922 and 1941. In the case of Italy in 1922, the new fascist regime forced the insurers to pay for damages caused by the Squadri. In Germany, the insurers were forced to assume a fictitious liability for damages done to the Jews in the Pogrom of November 1938. In Spain, Franco forced the insurance companies to treat Civil War damages as a civil commotion and make payouts despite their strenuous objections. These experiences demonstrated that civil commotion insurance was most safely marketed in democracies that provided enough unrest but also law and order to make it worthwhile.
French insurance from the ancien régime to 1946: shifting frontiers between state and market
Authors: RUFFAT MICHÈLE
Published: December 2003

This article considers the changing regulatory environment in which French insurance operated between the ancien régime and the post-war years. At first treated with suspicion, the state came to recognise the social benefits of insurance during the industrial revolution. The extension of regulation over different products and companies – life, marine, general – needs to be understood as a historical process in which first the benefits and then the possibilities for access to substantial financial resources came to be understood. A dual tradition of mistrust and fascination has prevailed in the French attitudes towards insurance, and this paper explores this relationship in a variety of contexts. It is suggested that the eventual nationalisation of much of the industry in 1946 was a signal of both increasing respectability and of the state's desire to offer universal coverage. The opportunity to mobilise and direct investment flows was also attractive.
Whither the book?
Authors: WRIGHT BARBARA
Published: December 2003

The prophets of gloom and the champions of progress are never done trying to discourage or inspire us with their various prognostications. Surveys show that fewer books are being read and Libraries find their budgets are increasingly being eaten up by subscriptions to ever more expensive periodicals. With electronic publication, collective authorship may seem to replace the individual writer. Furthermore, there is not, as yet, any adequate control over the veracity and reliability of information put up on the Internet.
Music for saints’ historiae in the Middle Ages. Liturgical chant and the harmony of the universe
Authors: HILEY DAVID
Published: December 2003

The article draws attention to a number of research initiatives in the area of liturgical plainchant, which have brought together scholars of different countries and disciplines. The number of primary sources is so great that cooperation is essential. In the first phase of modern scientific research, monks of the Benedictine Abbey of Solesmes played a crucial role, their combined efforts being rivalled by very few individual scholars. In the last quarter of a century, databases and computerized projects have been developed to which scholars from different countries can contribute and from which they can draw information, and these have to some extent replaced earlier communal efforts. When the seemingly uniform facade of plainchant is inspected closely it resolves itself into a multitude of overlapping traditions and styles: how many and how widespread they are can only be determined through international cooperation. Later stylistic phases, especially from the eleventh century onward, are influenced by a preoccupation with music as an aural reflection of the harmony of the universe.
Globalization as a problem, as a solution, and as a part of the landscape
Authors: GENSCHEL PHILIPP
Published: December 2003

There are basically three stories about the globalization– welfare state nexus. The first story argues that globalization is the cause of the chronic crisis of the welfare state. The second maintains that whatever the cause of the welfare state crisis, globalization is not part of it. The third story holds that globalization, far from causing the welfare state’s troubles, is a consequence of these troubles and part of their solution. The paper reviews each of these stories and traces their intellectual origins.