bluuebunny/crossref_metadata_2025 huggingface dataset:
The exonuclease ISG20 mainly localizes in the nucleolus and the Cajal (Coiled) bodies and is associated with nuclear SMN protein‐containing complexes
Authors: Espert Lucile , Eldin Patrick , Gongora Céline , Bayard Bernard , Harper Francis , Chelbi‐Alix Mounira K. , Bertrand Edouard , Degols Geneviève , Mechti Nadir
Published: March 2006

We have previously shown that ISG20, an interferon (IFN)‐induced gene, encodes a 3′ to 5′ exoribonuclease member of the DEDD superfamily of exonucleases. ISG20 specifically degrades single‐stranded RNA. In this report, using immunofluorescence analysis, we demonstrate that in addition to a diffuse cytoplasmic and nucleoplasmic localization, the endogenous ISG20 protein was present in the nucleus both in the nucleolus and in the Cajal bodies (CBs). In addition, we show that the ectopic expression of the CBs signature protein, coilin, fused to the red fluorescent protein (coilin‐dsRed) increased the number of nuclear dots containing both ISG20 and coilin‐dsRed. Using electron microcopy analysis, ISG20 appeared principally concentrated in the dense fibrillar component of the nucleolus, the major site for rRNA processing. We also present evidences that ISG20 was associated with survival of motor neuron (SMN)‐containing macromolecular nuclear complexes required for the biogenesis of various small nuclear ribonucleoproteins. Finally, we demonstrate that ISG20 was associated with U1 and U2 snRNAs, and U3 snoRNA. The accumulation of ISG20 in the CBs after IFN treatment strongly suggests its involvement in a new route for IFN‐mediated inhibition of protein synthesis by modulating snRNA and rRNA maturation. J. Cell. Biochem. 98: 1320–1333, 2006. © 2006 Wiley‐Liss, Inc.
Orthogonal group divisible designs of type hn for h ≤ 6
Authors: Zhang Xuebin
Published: March 2006

For the existence problem of OGDDs of type gu, Colbourn and Gibbons settled it with few possible exceptions for each group size g. In this article, we will completely settle it for g ≤ 6. © 2006 Wiley Periodicals, Inc. J Combin Designs
Self‐aggregated nanoparticles composed of periodate‐oxidized dextran and cholic acid: preparation, stabilization and in‐vitro drug release
Authors: Yuan Xu‐Bo , Li Hong , Zhu Xiao‐Xia , Woo Hee‐Gweon
Published: March 2006

A novel method was used to synthesize cholic acid hydrophobic‐modified dextrans (CAH–Dex) which form nanoparticles in aqueous solution. The stabilization and drug‐loading of the formed nanoparticles were investigated. Dextran was oxidized by sodium periodate to dextran dialdehyde which was then conjugated with cholic acid hydrazide through an acyl hydrazone linkage. The self‐aggregation behavior of the resulting conjugates was investigated using nuclear magnetic resonance, fluorescence and photo correlation spectrometry. The conjugates were found to have low critical aggregate concentrations (CAC) (0.46–0.96 × 10−2 mg mL−1) which is characteristic, depending on both the oxidization and substitution degrees. Above the CAC the conjugates tend to form nanoparticle aggregates with inner hydrophobic environment. The diameters of the nanoparticles rely on the pH of the medium due to the aldo–enol transition of the dextran dialdehyde. By crosslinking the aldehyde groups located on the surface using adipic dihydrazide, the nanoparticles were obviously stabilized. The drug‐loading and release behavior of the nanoparticles was investigated using indomethacin as a hydrophobic model drug. Copyright © 2006 Society of Chemical Industry
Raman spectrum of thiosaccharin
Authors: Baran Enrique J. , Zinczuk Juan
Published: March 2006

The Raman spectrum of crystalline thiosaccharin was recorded and assigned by comparison with known IR spectroscopic data derived from experimental as well as theoretical studies. Copyright © 2006 John Wiley & Sons, Ltd.
Cover Picture: Macromol. Biosci. 2/2006
Authors: Reibetanz Uta , Claus Claudia , Typlt Elke , Hofmann Jörg , Donath Edwin
Published: March 2006

Cover: Silica particles can be coated layerwise with polyelectrolytes. Using the plasmid encoding the green fluorescent protein (pEGFP‐C1) as a layer constituent particle uptake, release of particles into cytoplasm and defoliation of the polyelectrolyte multilayer are demonstrated by GFP expression in HEK 293T cells. Further details can be found in the Full Paper by U. Reibetanz, C. Claus, E. Typlt, J. Hofmann, and E. Donath* on page 153.
Atom Transfer Radical Polymerization of Styrene and Methyl Methacrylate from Mesoporous Ordered Silica Particles
Authors: Save Maud , Granvorka Gwenaëlle , Bernard Julien , Charleux Bernadette , Boissière Cédric , Grosso David , Sanchez Clément
Published: March 2006

Summary: Mesoporous silica was used as substrate for the grafting of alkyl halides initiators. The control over the surface‐initiated polymerization of styrene and MMA, in terms of molar mass and molar mass distribution, was successfully achieved using an ATRP mechanism. The occurrence of the polymerization inside the mesopores was confirmed by thermogravimetric analysis.

Transmission electron microscopy and schematic representation of mesoporous silica functionalized by the anchored iniator (left) and the grafted polymer (right).

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Transmission electron microscopy and schematic representation of mesoporous silica functionalized by the anchored iniator (left) and the grafted polymer (right).
Batch Emulsion Polymerization of Styrene Stabilized by a Hydrophilic Macro‐RAFT Agent
Authors: Manguian Maggy , Save Maud , Charleux Bernadette
Published: March 2006

Summary: A well‐defined homopolymer of 2‐(diethylamino)ethyl methacrylate has been synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization using (4‐cyanopentanoic acid)‐4‐dithiobenzoate as a chain transfer agent. The corresponding protonated homopolymer with a very reactive dithiobenzoate end group has been used as a water‐soluble macromolecular chain transfer agent in the batch emulsion polymerization of styrene without any surfactant. The reaction leads to a stable latex, as a result of the in‐situ formation of an amphiphilic block copolymer stabilizer, via transfer reaction to the dithioester functions during the nucleation step. The work does not intend to apply controlled free‐radical polymerization in an aqueous dispersed system but takes advantage of the RAFT technique to create a well‐defined polyelectrolyte, with a high chain‐end reactivity.

Schematic of the formation of the stabilized latex by the in situ formation of an amphiphilic block copolymer stabilizer.

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Schematic of the formation of the stabilized latex by the in situ formation of an amphiphilic block copolymer stabilizer.
Novel Hierarchic Structures in Polymer Blends
Authors: Buxton Gavin A. , Clarke Nigel
Published: March 2006

We use computer simulations to investigate the dissolution and phase separation process in polymer blends. In particular, we take initial cylindrical and spherical structures and allow them to dissolve in the one phase region. Before the structure can completely dissolve, however, we thrust the system into the two‐phase region. Phase separation then occurs such that hierarchic structures are formed both inside and outside the confines of the original structure. These novel hierarchic structures can be of significant technological importance.
Recent Developments for EPDM‐Based Thermoplastic Vulcanisates
Authors: van Duin Martin
Published: March 2006

An overview will be given on thermoplastic vulcanisates (TPVs). Like other thermoplastic elastomers, TPVs combine the elastic and mechanical properties of thermoset cross‐linked rubbers with the melt processability of thermoplastics. Emphasis will be on general‐purpose TPVs, based on resol‐cross‐linked EPDM/PP/oil blends. The following recent scientific developments will be discussed in detail: resol cross‐linking chemistry, extruder dynamic vulcanisation, TPV morphology, oil distribution, TPV elasticity model and TPV rheology. A series of scientific questions and technological problems, which are challenging future TPV developments, will be put forward at the end.
Waxy Maize Starch Nanocrystals as Filler in Natural Rubber
Authors: Angellier Hélène , Molina‐Boisseau Sonia , Dufresne Alain
Published: March 2006

Starch nanocrystals obtained from acid hydrolysis of waxy maize starch granules consist in crystalline nanoplatelets about 6–8 nm thick with a length of 20–40 nm and a width of 15–30 nm. New nanocomposite materials, i.e. natural rubber (NR) filled with waxy maize starch nanocrystals were processed by casting. Dynamic mechanical analysis has shown that starch nanocrystals were a good reinforcing agent for NR at temperatures higher than the glass transition temperature of NR. Tensile tests have shown that until a weight fraction of 20 wt%, this new filler presented the advantage to reinforce natural rubber without decreasing significantly the strain at break of the material. These properties may be due to both the morphological nature of starch nanocrystals, and the formation of a percolating starch nanocrystals network within the NR matrix, resulting from hydrogen bonding forces between starch aggregates.
Role of Polyelectrolytes in Crystallogenesis of Calcium Carbonate
Authors: Jada Amane , Jradi Khalil
Published: March 2006

The effects anionic polyelectrolytes, having various molecular weights and repeating unit structures, on the crystallization of calcium carbonate in supersaturated solutions are studied. The induction times of the crystals grown in the presence of the polymers were optically evaluated; X‐ray diffraction and Scanning Electronic Microscopy (SEM) analyses were performed to determine, respectively, their crystalline structures and morphologies. The polyelectrolyte is found to lengthen the induction time and to reduce the size of CaCO3 nanocrystallites, to an extent depending on the interaction efficiency between the polymer anionic repeating units and the calcium ions. Further, depending on their sizes and their crystalline structures (calcite, vaterite) the nanocrystallites aggregate and yield final calcium carbonate particles having various sizes and morphologies. The data indicate that nanocrystals having vaterite structure, as determined by X‐ray analysis, give spherical CaCO3 final particles, while nanocrystals having calcite structure lead to either acicular or flower shapes of CaCO3 final particles.
Microstructure of Nanocomposites of Styrenic Polymers
Authors: Carastan Danilo Justino , Demarquette Nicole Raymonde
Published: March 2006

Nanocomposites of three different styrenic polymers (polystyrene – PS, styrene‐butadiene‐styrene triblock copolymer – SBS, and styrene‐ethylene/butylene‐styrene triblock copolymer – SEBS) containing organophilic silicates have been prepared using three different techniques. The materials were prepared by melt mixing, solution casting and a process in which a highly filled masterbatch prepared by solution is mixed in the melt with the pure polymer. These composites were characterized by X‐ray diffraction (XRD), optical microscopy (OM), transmission electron microscopy (TEM) and small amplitude oscillatory shear analysis (SAOS). The results obtained showed that the nanocomposites of PS formed an intercalated microstructure, while those of SBS and especially SEBS are more easily exfoliated. To achieve this better silicate dispersion it was shown that it is necessary to use solution casting as one of the stages in the nanocomposite preparation. The masterbatch process showed to be an effective method to disperse the clay because it combines the advantages of the solution casting technique, which is good to dissolve coarse clay aggregates, and the shear provided by melt mixing.
Synthesis, Characterization and Properties of (Vinyl Triethoxy Silane‐grafted PP)/Silica Nanocomposites
Authors: Jain S. , Goossens J.G.P. , van Duin M.
Published: March 2006

A new route has been developed to produce PP/silica nanocomposites starting from porous PP reactor powder and making use of sol‐gel chemistry. Silica‐like, nano‐sized particles were prepared in the pores of the PP reactor powder with a controlled degree of adhesion between PP and silica. Magic‐angle spinning (MAS) 29Si NMR spectra showed that the chemical building blocks of the silica‐like clusters are of Q3 and Q4‐type. For (vinyl triethoxy silane (VTES)‐grafted PP)/silica nanocomposites, VTES was grafted via solid‐state modification (SSM) in porous PP particles. Subsequently, silica particles were prepared by sol‐gel technology in the VTES‐grafted PP. MAS 29Si NMR and FT‐IR spectroscopy showed that the grafted VTES becomes part of the in‐situ formed silica particles. The study on the mechanical properties of (VTES‐grafted PP)/silica nanocomposites showed that the silica particles improved the impact toughness of PP by a factor of 2, when there is no chemical interaction between the particles and the matrix, while for (VTES‐grafted PP)/silica nanocomposites the impact toughness decreased. This indicates that chemical bonding between the filler particles and the PP‐matrix results in brittle failure and supports the hypothesis that debonding is necessary for improving the impact toughness of PP with inorganic fillers.
Nanocomposites from Untreated Clay : A Myth ?
Authors: Fedullo Nicolas , Sclavons Michel , Bailly Christian , Lefebvre Jean‐Marc , Devaux Jacques
Published: March 2006

Polyamide 6 and pristine montmorillonite have been melt blended in an extruder and water was injected into the melt in order to produce nanocomposites. The pristine clay was found to be exfoliated and dispersed homogenously in the nanocomposites. A mechanism explaining the formation of such nanocomposites is presented.
Influence of Morphology on PTC in Conducting Polypropylene‐Silver Composites
Authors: Boiteux Gisèle , Boullanger Christophe , Cassagnau Philippe , Fulchiron René , Seytre Gérard
Published: March 2006

Blends of polypropylene with silver particles of controlled morphology are performed to elaborate polymer‐metal conductive composites which can present a PTC effect to be used for a specific current limited function. The samples present quite low percolation threshold around 22% in volume of Ag and a resistivity at room temperature around 100 ohm.cm. Looking at the results of the analysis of the PTC effect, it can be observed that the electrical behaviour of the samples is depending of the crystalline morphology of the systems which is governed by the specific nucleation effect of the silver filler on the polypropylene matrix.
Kinetics of Temperature‐induced and Reaction‐induced Phase Separation Studied by Modulated Temperature DSC
Authors: Pieters Ronny , Miltner Hans E. , Van Assche Guy , Van Mele Bruno
Published: March 2006

Temperature‐induced phase separation of P(EO75‐ran‐PO25)/PES and reaction‐induced phase separation of DGEBA/MDA modified with PVME are studied using MTDSC as an in‐situ tool. Phase separation can be probed by the onset of an ‘excess’ contribution in the MTDSC heat capacity signal, in good correspondence with the cloud point temperature. This feature enables the complete construction of the state diagram of P(EO75‐ran‐PO25)/PES. The detection of phase separation‐induced partial vitrification of the high‐Tg phase (PES‐rich phase) enables to sub‐divide the LCST‐type heterogeneous region in a zone 1 (no interference of partial vitrification) and a zone 2 (interference of partial vitrification of the PES‐rich phase). This sub‐division of the heterogeneous region has drastic implications on the remixing behavior of demixed blends. In DGEBA/MDA modified with PVME, reaction‐induced phase separation accompanied by an increase in reaction rate, followed by a vitrification step of the epoxy‐amine phase can be detected in‐situ. In non‐isothermal conditions, a diffusion‐controlled reaction after vitrification and a final devitrification of the system is also observed.
Mechanical and Rheological Behavior of Unvulcanized and Dynamically Vulcanized i‐PP/EPDM Blends
Authors: Prut Eduard , Medintseva Tatiana , Dreval Vadim
Published: March 2006

The mechanical and rheological behavior of dynamically vulcanized PP/EPDM blends is examined and compared with those of unvulcanized blends. The effect of blend ratio and dynamic vulcanization of EPDM rubber on tensile properties and flow are investigated. The mechanical properties of the blends are strongly influenced by the blend ratio. With the increasing of EPDM content the value of yield stress in a solid state decreases with the elastomer volume fractions less than 0.45 for the unvulcanized blends. For the dynamically vulcanized blends the interval of EPDM content, at which the yield peak is seen, is rather limited below 0.25 elastomer volume fractions. It is shown that dynamic vulcanization changes the deformational behavior of PP/EPDM blends. The rheological properties of dynamically vulcanized blends depending on the ratio of the components may be similar to the properties of polymer composites containing the highly disperse structuring filler. The distinction between the rheological behavior of unvulcanized and dynamically vulcanized blends is related to differences of their structures and viscoelastic characteristics of unvulcanized and vulcanized EPDM phase.
Contracting for management: Assessing management capacity under alternative service delivery arrangements
Authors: Brown Trevor , Potoski Matt
Published: March 2006

Contracting critics suggest that when governments outsource, they reduce their capacity to produce services and manage service delivery. In this paper, we decompose the service delivery decision into service production and service management components. When governments contract for service production, they may also choose to contract for a portion of service delivery management. Studies that only compare the management activities of contracting and direct service delivery governments, without examining the management activities contracted to vendors, are likely to be incomplete and biased. Drawing on a unique survey of governmental refuse collection service directors, matched with a survey of refuse collection vendors operating under municipal contracts, we show that the vendors' management activities offset the decline in management capacity that occurs when governments contract for service delivery for this particular service. Governments can “buy” management activities when contracting for service production. © 2006 by the Association for Public Policy Analysis and Management
Utility of PET scans to predict disease relapse in pediatric patients with Hodgkin lymphoma
Authors: Meany Holly J. , Gidvani Vinod K. , Minniti Caterina P.
Published: March 2006

Background

Positron emission tomography (PET) differentiates normal from abnormal cells based on metabolic activity. Numerous studies report that PET scan offers increased sensitivity, specificity and predictive values as compared to computed tomography (CT) in adult lymphoma patients.

Procedure

Twenty‐three consecutive pediatric Hodgkin lymphoma (HL) patients were evaluated with PET scan either at diagnosis or during treatment, then at therapy completion and in follow‐up.

Results

Twenty two of the 23 patients had a negative PET scan at the end of therapy; however, ten later developed a positive scan for a total of 11 (47.8%) patients with a positive post treatment PET scan. Six tissue biopsies were performed in five patients; four specimens were negative for disease and two confirmed HL relapse. Six patients were monitored clinically and remained asymptomatic; four had resolution of abnormalities on repeat PET while two had persistently positive, but stable PET scan findings and continue to be in remission at 11 and 40 months following treatment. Twelve (52.2%) patients of the original cohort have had consistently negative PET scans and have not relapsed.

Conclusions

PET is a sensitive (100%), but not a specific (57.1%) method for evaluating post‐treatment pediatric HL patients with a strong negative predictive value (NPV; 100%), but poor positive predictive value (PPV; 18.2%). We do not recommend treatment decisions be based solely on PET scan results. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.
Neediness and connectedness and the five‐factor model of personality
Authors: Dunkley David M. , Blankstein Kirk R. , Zuroff David C. , Lecce Sandra , Hui Denise
Published: March 2006

This study examined maladaptive and relatively more adaptive forms of dependency, as measured by the neediness and connectedness factors of the Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976), within a comprehensive scheme of personality provided by the revised NEO Personality Inventory (NEO‐PI‐R; Costa & McCrae, 1992). University students (n = 475) completed the DEQ, NEO‐PI‐R, and a measure of depressive symptoms. Results indicated that neediness reflected anxiety, self‐consciousness, vulnerability, unassertiveness, and inactivity, whereas connectedness reflected anxiety, warmth, agreeableness, and valuing of relationships. Neediness demonstrated stronger relations than connectedness with depressive symptoms. These results support the validity of DEQ neediness and connectedness as measures of maladaptive and relatively more adaptive forms of dependency. Copyright © 2006 John Wiley & Sons, Ltd.
Anionic/nonionic mixed surfactants templates preparation of hollow polymer spheres via emulsion polymerization
Authors: Song Linyong , Ge Xuewu , Wang Mozhen , Zhang Zhicheng , Li Shicheng
Published: March 2006

We herein report a facile, convenient, and economical method to prepare hollow polymer spheres (HSs). By virtue of the phase transformation of nonionic surfactant at its cloud point, hollow spheres of polystyrene were prepared from vesicle templates formed by potassium oleate (KO) and alkyl‐phenol polyoxyethylene (n) ether (n = 10, OP) at 70–80 °C. The morphologies of the HSs were characterized by field‐emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The diameter of the HSs varies from 200 to 800 nm, and the shell thickness is uniformly c.a. 30–50 nm. The weight ratio of monomer/surfactant was as high as 7/1. The microstructure of the HSs was very stable and remained unchanged after drying or resuspension in water. The mechanism of the formation of HSs was explained on the theory of vesicles. Furthermore, the factors affecting the formation of the hollow structure were discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2533–2541, 2006
Synthesis and properties of polyacetylenes with directly attached bis(4‐alkoxyphenyl)terephthalate mesogens as pendants
Authors: Chen Lie , Chen Yiwang , Zha Daijun , Yang Yan
Published: March 2006

Liquid‐crystalline, monosubstituted polyacetylenes containing lateral pendants of bis(4‐alkoxyphenyl)terephthalate with no flexible spacers and alkoxy tails {RO, where R is CH3 [P(1)] or C6H13 [P(6)]} were synthesized, and the effects of the backbone structure and alkoxy tails on the properties of the polymers were investigated. The polymerizations of acetylene monomers were carried out with chloronorbornadiene rhodium(I) dimer as a 1,2‐insertion catalyst in toluene. The structures and properties of the monosubstituted polyacetylenes were characterized and evaluated with nuclear magnetic resonance, infrared spectroscopy, thermogravimetry, differential scanning calorimetry, polarized optical microscopy, ultraviolet spectroscopy, and photoluminescence analyses. The molecular weights of the polymers were measured by gel permeation chromatography. The polymer with long tails (p‐hexyloxy), that is, P(6), formed a smectic mesophase upon heating above the melting temperature, but the other one with short tails (p‐methoxy), that is, P(1), could not exhibit liquid crystallinity at elevated temperatures. The steric effect of bulky, liquid‐crystalline mesogens and a direct connection with the main chain prevented the planar conformation of the polyene backbone and, therefore, led to the lower absorption and emission wavelength of the polymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2499–2509, 2006
Polyglutamine repeats and β‐helix structure: Molecular dynamics study
Authors: Merlino Antonello , Esposito Luciana , Vitagliano Luigi
Published: March 2006

Neurodegenerative diseases are often associated with the formation of highly insoluble aggregates. Despite the efforts devoted to the characterization of these aggregates, their structure remains elusive. Several neurodegenerative diseases are characterized by the expansion of CAG repeats, which code for Gln. Among the structural models proposed for the aggregates observed in polyQ‐linked diseases, the nanotube β‐helix model proposed by Perutz and colleagues Proc Natl Acad Sci U S A 2002;99:5591–5595 has been influential. In the present study, the stability of this β‐helix model has been investigated by performing molecular dynamics simulations on polyQ fragments of different lengths. The results indicate that models shorter than two full β‐helix turns are unstable and collapse toward irregular structures. On the other hand, longer β‐helix models, containing more than 40 residues, achieve a dynamic regular structure. This finding is in line with the observed threshold of Gln repeats (≈ 40) correlated with the insurgence of the disease. Notably, the structure of the final state of the models longer than 40 residues strictly depends on their size. A compact stable ellipsoidal structure is formed by the model made of two full helical turns (41 residues), whereas water filled tubular structures emerge from simulation on longer polypeptides. These results have been interpreted taking into account the experimental data on polyQ aggregates. A structural interpretation of the literature data has been proposed by assuming that different β‐helical models are involved in the different stages of the aggregation process. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Carbon nanodots made on diamond surface by focused ion beam
Authors: Zaitsev Alexander M. , Dobrinets Inga A.
Published: March 2006

Carbon nanodots were made on the polished surface of a single crystal CVD diamond by a focused 30 keV Ga+ ion beam. The electrical conductance via the nanodots was measured in two types of structures: single nanodots embedded in the gaps of broken carbon nanowires and linear chains of nanodots. Changes of the conductance with annealing temperature allow to make the conclusion that the size of the electrically conductive area of the nanodots increases from a few nanometers to 20 nm after annealing from 500 to 1000 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development and validation of a technique to measure and compare the opening characteristics of tamper‐evident bottle closures
Authors: Carus D. A. , Grant C. , Wattie R. , Pridham M. S.
Published: March 2006

Large sections of the population encounter difficulty in opening consumer packaging of many kinds. Screw‐caps in particular can cause problems for a range of people with a variety of impairments. This paper describes the development and initial testing of a novel multi‐axial force and torque transducer, designed for the study of loading conditions when tamper‐evident bottle closures are opened manually. The transducer, which comprises seven beams that are sensitive to direct forces and torques in each of three axes, can provide comprehensive information on the loading conditions that occur when an instrumented bottle is opened. Importantly, the transducer has been designed to fit inside a typical 500 ml capacity plastic soft drinks bottle so that it does not interfere with the way in which the subject grips the bottle and cap, or applies forces and torques, in order to open the bottle. The method to obtain load data from the calibration matrix, along with initial opening force and torque test data from two user groups, elderly and young, is described. It is clear from the results of these tests that the elderly and young groups exhibit significantly different torque and force profiles to open bottles. It is anticipated that the transducer will be a valuable tool in future studies of opening strategies. Copyright © 2006 John Wiley & Sons, Ltd.
Sustainable natural resource use and economic development in small states: the tuna fisheries in Fiji and Samoa
Authors: Read Robert
Published: March 2006

This paper is concerned with the sustainable management of the Western Pacific tuna fishery given its critical contribution to the economies of many small island developing states in the region. The paper focuses on contrasting the operation, regulation and management of the tuna fisheries in two Pacific island states, Fiji and Samoa, in the light of progress in regional fishery co‐operation, and is based upon research undertaken in 2003. The analysis identifies critical shortcomings in implementation and enforcement of sustainable management policies in Fiji, which compare unfavourably with Samoa's attempts to ensure the long‐term sustainability of a crucial economic sector. The principal differences in the effectiveness of these policies can be ascribed to the quality of governance as well as the general coherence of national economic policies. The paper attempts to highlight some of the problems faced by small developing states in ensuring the long‐term sustainability of an important migratory marine resource. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Lehrter Bahnhof Berlin: Das Nord‐Süd‐Dach
Authors: Gugeler Jochen , Havemann Kathrin , Schober Hans
Published: March 2006

Seit Herbst 2002 überspannt eine gläserne Bahnsteighalle die oberirdische Trasse des neuen Hauptbahnhofs von Berlin. Das zweite filigrane Tonnendach – das Nord‐Süd‐Dach – wird gerade vollendet. Anstelle der Pfetten historischer Bahnsteighallen spannt eine effiziente Stabschale zwischen schlanken Seilbindern. Das gesamte Dach sowie die abschließenden Seilfassaden stellen höchste Anforderungen an Statik und Detailplanung. Zahlreiche Sonderkonstruktionen, umfangreiche Versuche und nicht zuletzt die Montage bei laufendem Bahnverkehr waren eine große Herausforderung für alle Beteiligten.
Bahnhofshallen im Osten Deutschlands
Authors: Weller Bernhard , Tasche Martin
Published: March 2006

Die Geschichte des Eisenbaus ist eng verbunden mit der Ausprägung des Konstruktiven Ingenieurbaus im 19. Jahrhundert [1]. An der Eisenbahn läßt sich die Entstehung des Neuen der mechanisierten Zivilisation exemplarisch ablesen [2]. Die großstädtischen Bahnhöfe, insbesondere die großen Hallenbauwerke, machen einen Abschnitt der Geschichte des Konstruierens unmittelbar erfahrbar. Die Beschreibung der Bahnhofshallen in Ostdeutschland ist Auftakt einer Reihe, die in loser Folge über die Konstruktionsgeschichte ausgewählter Bauformen berichten wird.
Teaching nature of science within a controversial topic: Integrated versus nonintegrated
Authors: Khishfe Rola , Lederman Norman
Published: March 2006

This study investigated the influence of two different explicit instructional approaches in promoting more informed understandings of nature of science (NOS) among students. Participants, a total of 42 students, comprised two groups in two intact sections of ninth grade. Participants in the two groups were taught environmental science by their regular classroom teacher, with the difference being the context in which NOS was explicitly taught. For the “integrated” group, NOS instruction was related to the science content about global warming. For the “nonintegrated” group, NOS was taught through a set of activities that specifically addressed NOS issues and were dispersed across the content about global warming. The treatment for both groups spanned 6 weeks and addressed a unit about global warming and NOS. An open‐ended questionnaire, in conjunction with semistructured interviews, was used to assess students' views before and after instruction. Results showed improvements in participants' views of NOS regardless of whether NOS was integrated within the regular content about global warming. Comparison of differences between the two groups showed “slightly” greater improvement in the informed views of the integrated group participants. On the other hand, there was greater improvement in the transitional views of the nonintegrated group participants. Therefore, the overall results did not provide any conclusive evidence in favor of one approach over the other. Implications on the teaching and learning of NOS are discussed. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 395–418, 2006
The conservative management of cervical ectopic pregnancies
Authors: Kirk E. , Condous G. , Haider Z. , Syed A. , Ojha K. , Bourne T.
Published: March 2006

Objective

To evaluate the role of conservative management in the treatment of cervical ectopic pregnancies.

Methods

This was a retrospective analysis of all cervical ectopic pregnancies diagnosed in women attending our early pregnancy unit between April 1997 and September 2004 inclusive. The diagnosis of cervical ectopic pregnancy was made using transvaginal ultrasound. Clinical and demographic data were recorded in all cases. Serum human chorionic gonadotropin levels were measured at presentation and monitored subsequently to determine the rate of successful resolution. Conservative management was in the form of medical or expectant management. Medical management involved administration of systemic or intra‐amniotic methotrexate, with or without intra‐amniotic potassium chloride. Systemic methotrexate was either a single dose of 50 mg/m2 or an alternate‐day regimen of methotrexate at 1 mg/kg (days 1,3,5) with folinic acid rescue (days 2,4,6). If intra‐amniotic treatment was required, this was either 50 mg methotrexate or 5 mmol/L potassium chloride.

Results

Seven cervical ectopic pregnancies were diagnosed during the study period. Three cases were managed successfully with a single dose of methotrexate. One case was managed successfully using a multiple‐dose methotrexate regimen. Another case failed medical management with both the single‐ and multiple‐dose regimens but was successfully treated after potassium chloride was given intra‐amniotically under ultrasound guidance. One case was successfully treated with intra‐amniotic methotrexate and another was managed expectantly. There was no associated morbidity or mortality during the study period. We also performed a review of the current literature.

Conclusion

The conservative management of cervical ectopic pregnancy is effective and safe. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Adaptive polynomial predistorters for M‐QAM transmission using non‐linear power amplifiers
Authors: Vo Thai Hoa , Le‐Ngoc Tho , Besbes Hichem
Published: March 2006

In this paper, adaptive baseband polynomial predistortion techniques are introduced to counter‐balance the AM/AM and AM/PM non‐linear effects of the transmit power amplifier. The proposed polynomial predistortion scheme is based on polar coordinate representation. Both LMS and RLS concepts are used to derive the adaptive algorithms. An enhanced LMS‐based algorithm with fast convergence and low complexity is proposed. For very fast convergence, a cascaded RLS‐based adaptive polynomial predistorter structure is introduced. The performance of the proposed schemes in terms of intermodulation distortion, spectral regrowth, and convergence rate are examined. The obtained results show that the polynomial predistortion schemes can be used in M‐QAM transmitters with power amplifiers operating near saturation to achieve a highest power efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Adding sense of spatial locality to routing protocols for mobile ad hoc networks
Authors: Chang Ruay‐Shiung , Tsai Chang‐Zhou
Published: March 2006

Recently, there has been an increasing interest in mobile ad hoc networks. In a mobile ad hoc network, each mobile node can freely move around and the network is dynamically constructed by collections of mobile nodes without using any existing network infrastructure. Compared to static networks, it faces many problems such as the inefficiency of routing algorithms. Also, the number of control packets in any routing algorithm increases as the mobile speed or the number of mobile nodes increases. Most of the current routing protocols in ad hoc networks broadcast the control packets to the entire network. Therefore, by reducing the number of control packets, the efficiency of the network routing will be improved. If we know where the destination is, we can beam our search toward that direction. However, without using global positioning systems, how can we do this? Define the range nodes as the 1‐hop or 2‐hop neighbors of the destination node. In this paper, we propose using the range nodes to direct our searches for the destination. It can be combined with the existing routing protocols to reduce the control overhead. We show through simulations that AODV and DSR combined with the range node method outperforms the original AODV and DSR routing protocols in terms of control packets overhead. We also show that the delay introduced in find range nodes is insignificant. Copyright © 2006 John Wiley & Sons, Ltd.
Optimal decision strategies for paging in mobile cellular networks
Authors: Koukoutsidis I. Z. , Demestichas P. P. , Papaioannou P. I. , Theologou M. E.
Published: March 2006

A high‐level technical survey of paging in mobile cellular communication networks is presented in this paper. We view paging as an optimal decision problem and explore different strategies based on sequential decisions. The examined schemes concentrate on different perspectives of the problem, depending on the type of decisions and the amount of information available or exploitable by the system. This approach provides a useful categorization and an easy conceptual basis for their theoretical investigation, necessary for the deployment of advanced paging algorithms. Because of its suggested generality, the discussed framework is also laid as reference for further research. As modern networks evolve, more emphasis will be given towards optimization in all aspects of a network system. The schemes presented greatly reduce paging costs and can be used in cooperation with known location update strategies to make part of a real network location management system. Copyright © 2006 John Wiley & Sons, Ltd.
Attention bias to faces in Asperger Syndrome: a pictorial emotion Stroop study
Authors: ASHWIN CHRIS , WHEELWRIGHT SALLY , BARON-COHEN SIMON
Published: March 2006

Background. Emotional Stroop tasks have shown attention biases of clinical populations towards stimuli related to their condition. Asperger Syndrome (AS) is a neuropsychiatric condition with social and communication deficits, repetitive behaviours and narrow interests. Social deficits are particularly striking, including difficulties in understanding others.

Method. We investigated colour-naming latencies of adults with and without AS to name colours of pictures containing angry facial expressions, neutral expressions or non-social objects. We tested three hypotheses: whether (1) controls show longer colour-naming latencies for angry versus neutral facial expressions with male actors, (2) people with AS show differential latencies across picture types, and (3) differential response latencies persist when photographs contain females.

Results. Controls had longer latencies to pictures of male faces with angry compared to neutral expressions. The AS group did not show longer latencies to angry versus neutral expressions in male faces, instead showing slower latencies to pictures containing any facial expression compared to objects. When pictures contained females, controls no longer showed longer latencies for angry versus neutral expressions. However, the AS group still showed longer latencies to all facial picture types, compared to objects, providing further evidence that faces produce interference effects for this clinical group.

Conclusions. The pictorial emotional Stroop paradigm reveals normal attention biases towards threatening emotional faces. The AS group showed Stroop interference effects to all facial stimuli regardless of expression or sex, suggesting that faces cause disproportionate interference in AS.
No evidence for preferential involvement of medial temporal lobe structures in high-functioning autism
Authors: PALMEN SASKIA J. M. C. , DURSTON SARAH , NEDERVEEN HILDE , VAN ENGELAND HERMAN
Published: March 2006

Background. Autism is a neurodevelopmental disorder associated with slight increases in brain volume. There has been some suggestion that medial temporal lobe structures may be preferentially involved in this disorder, although results have not always been consistent. Here, we investigate amygdala and hippocampus volumes in medication-naive subjects with high-functioning autism.

Method. Whole-brain magnetic resonance imaging scans were acquired from 42 patients and 42 closely matched, healthy control subjects.

Results. Amygdala volume did not differ significantly between patients and controls. A significant increase in hippocampal volume was proportional to an increase in overall brain volume.

Conclusions. These results argue against preferential involvement of medial temporal lobe structures in autism, at least in high-functioning medication-naive individuals.
Controlling a bipedal walking robot actuated by pleated pneumatic artificial muscles
Authors: Vanderborght Bram , Verrelst Björn , Van Ham Ronald , Lefeber Dirk
Published: March 2006

This paper reports on the control structure of the pneumatic biped Lucy. The robot is actuated with pleated pneumatic artificial muscles, which have interesting characteristics that can be exploited for legged locomotion. They have a high power to weight ratio, an adaptable compliance and they can absorb impact effects.

The discussion of the control architecture focuses on the joint trajectory generator and the joint trajectory tracking controller. The trajectory generator calculates trajectories represented by polynomials based on objective locomotion parameters, which are average forward speed, step length, step height and intermediate foot lift. The joint trajectory tracking controller is divided in three parts: a computed torque module, a delta-p unit and a bang-bang pressure controller. The control design is formulated for the single support and double support phase, where specifically the trajectory generator and the computed torque differs for these two phases.

The first results of the incorporation of this control architecture in the real biped Lucy are given. Several essential graphs, such as pressure courses, are discussed and the effectiveness of the proposed algorithm is shown by the small deviations between desired and actual attained objective locomotion parameters.
A Reference Architecture for Natural Language Generation Systems
Authors: MELLISH CHRIS , SCOTT DONIA , CAHILL LYNNE , PAIVA DANIEL , EVANS ROGER , REAPE MIKE
Published: March 2006

We present the RAGS (Reference Architecture for Generation Systems) framework: a specification of an abstract Natural Language Generation (NLG) system architecture to support sharing, re-use, comparison and evaluation of NLG technologies. We argue that the evidence from a survey of actual NLG systems calls for a different emphasis in a reference proposal from that seen in similar initiatives in information extraction and multimedia interfaces. We introduce the framework itself, in particular the two-level data model that allows us to support the complex data requirements of NLG systems in a flexible and coherent fashion, and describe our efforts to validate the framework through a range of implementations.
Gender Ratios in European Psychology
Authors: Olos Luiza , Hoff Ernst-H.
Published: March 2006

An international comparison of gender distribution in European psychology shows that the development of the profession is insufficiently documented in many countries, indicating that psychology is not yet very professionalized. Women outnumber men in all countries examined. In several countries, the ratio of women has remained so high over the past 20 years that psychology could be called a “female-dominated profession.” In other countries, the percentage of women has continuously increased, and psychology appears to be developing from an integrated profession to a female-dominated profession. However, we cannot refer to a female-dominated profession overall, as some occupational fields are dominated by men, while women work part-time more frequently and are less likely to gain permanent or higher positions.
The Connections Between Adulthood Transitions and the Self-Perception of Being Adult in the Changing Contexts of East and West Germany
Authors: Reitzle Matthias
Published: March 2006

Against the backdrop of young people's increasingly later role-transitions (discussed as postadolescence or emerging adulthood), the present study examined whether (1) young people of different cohorts decreasingly perceived themselves as adults, and (2) their self-perceptions of being adult were disconnected from role transitions. Young people were asked whether they felt themselves to be adults, adolescents, or something else. The study was based on two surveys conducted in 1991 and 1996 in East and West Germany. The present sample consisted of 20- to 27-year-olds (N = 3171). A complex pattern of findings was expected with regard to education, gender, and differential social change in East and West. Irrespective of time, college-bound youths' rates of subjective adulthood and transitions were lower than those of non-college-bound youth. Furthermore, their subjective adulthood was not connected to role transitions. Transition rates of non-college-bound youth remained stable among Westerners, but significantly declined among Easterners because of their financial insecurity during the restructuring phase of East Germany's economy. Among less-educated youth, subjective adulthood remained connected to role transitions. It was concluded that emerging adulthood applies primarily to well-educated youth whereas segments of noncollege-bound young people still adhere to conventional adulthood conceptions.
The Association of Interpersonal Stress with Psychological Distress in Romania
Authors: Bancila Delia , Mittelmark Maurice B. , Hetland Jørn
Published: March 2006

Data from a community sample in Romania are presented on how social support and stress in interpersonal relationships are related to psychological distress (depressive symptoms, anxiety, and loneliness). Other predictor variables in the study were stress from daily living, self-efficacy, age, and gender. An important feature was the inclusion of measures of positive and negative aspects of interpersonal relationships. Many studies emphasize either social support, or interpersonal stress, but rarely both. A random population-based sample of 1000 was drawn from age groups 25-29, 40-44 and 75-79. A study questionnaire was mailed to the sample. The analysis sample size was 581 (63 percent of the 922 persons located). The hypothesized relationships between the stressors, the resources, and psychological distress were examined using structural equation models. All the fit statistics indicated a good fit of the data to the model. The variance in psychological distress explained by the predictor variables was 0.83. There were no statistically significant age differences in the relationship between the predictors and psychological distress. Results confirm the study's basic premise, that social support influences psychological distress levels in a protective way, as does self-efficacy, while interpersonal stress and worries about daily living are significant predictors for elevated psychological distress. The study confirms the importance of including measures of positive and of negative social ties in studies of psychological distress in community samples.