bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformation mechanisms of nanoclay‐reinforced maleic anhydride‐modified polypropylene
Authors: Chen Ling , Wong Shing‐Chung , Liu Tianxi , Lu Xuehong , He Chaobin
Published: June 2004

Fracture properties and deformation mechanisms of nanoclay‐reinforced maleic anhydride‐modified polypropylene (MAPP) were investigated. Elastic–plastic fracture mechanics was employed to characterize the toughness in light of substantial postyield deformation for the reinforced MAPP. Upon introduction of 2.5 wt % clay loading in maleated MAPP, it was observed that tensile strength, modulus, and fracture initiation toughness concomitantly increased substantially. Continued increase in clay loading thereafter only led to stiffening and strengthening effects to the detriment of fracture toughness. A plot of the J‐integral initiation fracture toughness versus the plastic zone size demonstrated that toughening arose from plastic deformation in the reinforced matrix. Careful examination of deformed tensile specimens using small angle X‐ray scattering (SAXS) showed 2.5 wt % clay gave rise to the highest equatorial scattering, which indicates the presence of microvoids in the matrix. The SAXS results were consistent with that shown in subcritically loaded crack‐tip deformation zone using transmission electron microscopy. Thus, both macroscale three‐point bend fracture data and SAXS results led us to consistent findings and conclusions. Further increase in clay loading above 2.5 wt % reduced the scattering the matrix plasticity and thus the fracture toughness. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2759–2768, 2004
Nonlocal potentials for short‐range electronic correlation in atoms, molecules, and solids
Authors: Nesbet R. K.
Published: June 2004

Extending density functional theory (DFT) to an ab initio orbital functional theory (OFT) requires new methodology for nonlocal exchange and correlation potentials. This article describes such modifications to a standard Dirac–Slater atomic program. Unrestricted Hartree–Fock (UHF) theory is extended by a modified Colle–Salvetti ansatz for short‐range electronic correlation. Results are reported for atoms He–Ne. Values of parameters needed for similar calculations on molecules and solids are reported. Implementation of nonlocal exchange and correlation for such extended systems, using multiple scattering theory to connect independent calculations in space‐filling atomic cells, is discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Die Elbebrücke Blaues Wunder in Dresden – Tragwerk und Maßnahmen zur weiteren sicheren Nutzung
Authors: Geißler Karsten
Published: June 2004

Die Elbebrücke “Blaues Wunder” in Dresden wird dieses Jahr 111 Jahre alt und soll als ein Wahrzeichen der Stadt Dresden noch möglichst lange genutzt werden. Im folgenden Beitrag werden nach einem Überblick zum System der Brücke mit seinen zahlreichen Besonderheiten insbesondere die Fragen der Nachrechnung, Restnutzungsdauerermittlung und weiteren sicheren Nutzung des Stahltragwerks sowie der Ankerkammern beschrieben.
Zur Rotationssteifigkeit standardisierter geschraubter Stirnplattenverbindungen nach Eurocode
Authors: Unterweger Harald , Greiner Richard
Published: June 2004

Der Beitrag behandelt die im Stahlhochbau häufig verwendeten standardisierten Träger‐Stützen‐Verbindungen nach dem deutschen DSTV/ DASt‐Ringbuch [1] und dem österreichisch‐schweizerischen ÖSTV/SZS‐Katalog [2]. Die rechnerischen Rotationssteifigkeiten des Gesamtknotens – ermittelt nach dem aktuellen Eurocode 3, Teil 1.8 [3] – werden mit den Tabellenwerten in [4] verglichen. Weiterhin werden die Verbindungen in Abhängigkeit der Ausführungsform klassifiziert, so daß erkennbar wird, ob der Knoten als starr oder nachgiebig in der Systemberechnung anzusehen ist.

Um generelle Tendenzen für die Praxis hinsichtlich der Rotationssteifigkeit der Knoten ableiten zu können, wird der Einfluß der Knotengeometrie (Trägerhöhe, Stützenhöhe, Schraubendurchmesser, Profilart) und der Verstärkung des Stützenstegs dargestellt. Ergänzend werden die Anteile der einzelnen Komponenten an der Gesamtsteifigkeit der Verbindung bzw. des Knotens für repräsentative Ausführungsformen gegenübergestellt.
Untersuchung der Anrißlebensdauer von Betondübeln mit Hilfe des Örtlichen Konzepts
Authors: Lange Jörg , Song Jaejoon
Published: June 2004

Die Herstellung eines guten Verbunds zwischen Betonplatte und Stahlträger ist für die Tragfähigkeit, Wirtschaftlichkeit und Gebrauchstauglichkeit eines Verbundträgers von grundlegender Bedeutung. Betondübel stellen hierbei eine neue Möglichkeit dar. Sie bestehen aus gelochten, auf den Stahlträger aufgeschweißten Stahlblechen. Ihr besonderer Vorteil gegenüber den bisher verwendeten Verbundmitteln liegt in dem konstruktionsbedingten guten Verhalten gegenüber wechselnden Beanspruchungen. Im vorliegenden Aufsatz wird dies mit Hilfe des Örtlichen Konzepts untersucht und bestätigt.
Untersuchungen und theoretische Modelle von druckbeanspruchten Stahlstützen in Verbundbauweise
Authors: Żółtowski Wojciech , Szmigiera Elżbieta , Kosmalski Sławomir
Published: June 2004

Im Aufsatz wird über den Verlauf und die Ergebnisse zu Untersuchungen von Verbundstützen berichtet. Dies ist der erste Abschnitt einer Untersuchungsreihe zu ausgewählten Problemen mit Stützen unter axial wirkenden Belastung.

Im ersten Schritt konzentrierte man sich auf die Untersuchung von Faktoren, die die Tragfähigkeit und die Verformbarkeit der Verbundstützen wesentlich beeinflussen können. Besonders wurde auf die Art der Lasteintragung und die Abstützung der Verbundstütze eingegangen. Dies ergab, daß bei Lasteintrag über ein auskragendes Stahlprofil der Grenzzustand der Nutzung dieser Stütze durch Risse früher erreicht wird als deren mögliche maximale Tragfähigkeit.

Die genannte Belastungart erzeugt hohe Dehnungen im Stahlprofil. Eine steife Einspannung der Stütze verursacht eine Minderung der Tragfähigkeit durch Spannungskonzentration in den Auflagerzonen.

Es wurde festgestellt, daß über das Versagen einer Verbundstütze der Spannungszustand in der Betondeckung entscheidet.

Die Ergebnisse sind besonders angesichts der im Eurocode 4 enthaltenen Festlegungen und auch der polnischen Normen von Bedeutung. Beide Normen berücksichtigen bei der Tragfähigkeitsberechnung von Verbundstützen die Art der Lasteinwirkung nicht.

Nach Meinung der Autoren ist auch die Einspannung der Stützen im Auflager ungenügend berücksichtigt.

In der vereinfachten Berechnungsmethode in EC 4 kann man die Knicklänge einer unverschiebbar gehaltenen Verbundstütze gleich deren Axiallänge nehmen. Somit muß die Art der Lagerung der Verbundstütze nicht analysiert werden.

Die Ergebnisse zeigen jedoch, daß die Tragwerksplaner die untersuchten Faktoren beachten müssen, auch wenn sie nicht in den Normen enthalten sind, da sie die Tragfähigkeit und somit die Statik wesentlich beeinflussen.

Die Untersuchungen zeigen die Möglichkeit, die Tragfähigkeit einer eingespannten Verbundstütze durch ein mit Faserbeton verstärktes Kopfstück zu erhöhen.
Untersuchungen zur Längssteifigkeit von Stahlstützen mit kastenförmigem Querschnitt
Authors: Kubica Ernest , Ignatowicz Rajmund
Published: June 2004

In Konstruktionssystemen aus dünnwandigen Elementen ist es wichtig festzustellen, wie die gedrückten Elemente ihre Steifigkeit mit der steigenden Belastung verändern. Eine ungleichmäßige nderung der Längssteifigkeit hat eine nderung der Kräfte‐ und Spannungsverteilung zur Folge. Nachgiebigere Konstruktionselemente übernehmen den kleineren Teil der Belastung, wobei die steiferen, gezogenen Elemente, überbelastet sind. Bei Stahlelementen, bei denen sich die Längssteifigkeiten mit der Lastzunahme verringern, unterscheidet man versteifte Bleche und Stahlstützen mit geschlossenem kasten‐ und rohrförmigem Querschnitt.

Eine Kürzung des Stabs im elastisch‐plastischen Bereich ist auf Materialdruck, Wellung der Querschnittswände und stärkere Biegung des ganzen Stabs zurückzuführen. Einen bedeutenden Einfluß auf die nderung der Stabsteifigkeit haben Imperfektionen, deren Werte von der Querschnittsgestaltung abhängig sind. Dies läßt sich zusammen mit anderen Faktoren aufgrund der Formen der Lastdehnungs‐ und Lastverformungskurven der untersuchten Elemente bestimmen. Bis zum Erreichen der Traglast wurden diese Kurven mittels numerischer Inkrementalmethode der Integration von Gleichgewichtsgleichungen für angenommene Vorverformungen und Eigenspannungen in den Stützenwänden sowie Vorverformungen der Stützenachsen ermittelt. Für die gewählten numerischen Lösungen wurde das Programm LUSAS genutzt. Die theoretischen Analysen wurden an Elementen in Originalgröße durchgeführt: Stützen mit kastenförmigen Querschnitten mit einer Länge von 5280 mm und Stützen mit einem Querschnitt aus kaltgeformten Profilen und einer Länge von 2000 mm. Es wurden ebenfalls die Untersuchungsergebnisse anderer Forschungseinrichtungen genutzt.
Traglastberechnung von Durchlaufträgern nach der Fließgelenktheorie II. Ordnung
Authors: Wostrack Dieter
Published: June 2004

Es wird ein einfaches Näherungsverfahren zur Ermittlung der Traglasten in den Feldern starr gestützter Durchlaufträger und anderer unverschieblicher Systeme nach der Fließgelenktheorie II. Ordnung vorgestellt. Die Genauigkeit des Verfahrens ist durch manuelle Vergleichsrechnungen nach der Deformationsmethode II. Ordnung und iterativ über computergestützte Stabwerksprogramme kontrolliert.
Chromosome translocation induced by the insertion of the URA blaster into the major repeat sequence (MRS) in Candida albicans
Authors: Iwaguchi Shin‐Ichi , Suzuki Mina , Sakai Naomi , Nakagawa Yoshiyuki , Magee Paul T. , Suzuki Takahito
Published: June 2004

Electrophoretic karyotype studies have shown that clinical isolates of Candida albicans have extensive chromosome length polymorphisms. Chromosome translocation is one of the causes of karyotypic variation. Chromosome translocation events have been shown to occur very frequently at or near the major repeat sequence (MRS) on chromosomes. The MRS consists of the repeated sequences RB2, RPS and HOK, and the repeated sequences are considered to be the template for recombination. To investigate which element of the MRS is important for chromosome translocation, we constructed three cassettes, each containing a URA blaster and sequences homologous to one of the repeats, for insertion into the MRS region on the chromosomes. The ura3 strain STN22u2, which shows a stable, standard karyotype, was transformed with each construct. Insertion events with each cassette occurred at almost all chromosomes. Insertion into the RB2 repeat, but not into the RPS repeat, was accompanied by chromosome translocation in some transformants: chromosome translocations between chromosomes R and 7 and chromosomes 1 and 7 were found, as well as deletions of 7A and 7C from chromosome 7. We conclude that the insertion at the RB2 region may initiate chromosome translocation in C. albicans. Copyright © 2004 John Wiley & Sons, Ltd.
Transcriptional profiling of extracellular amino acid sensing in Saccharomyces cerevisiae and the role of Stp1p and Stp2p
Authors: Eckert‐Boulet Nadine , Nielsen Peter Stein , Friis Carsten , dos Santos Margarida Moreira , Nielsen Jens , Kielland‐Brandt Morten C. , Regenberg Birgitte
Published: June 2004

S. cerevisiae responds to the presence of amino acids in the environment through the membrane‐bound complex SPS, by altering transcription of several genes. Global transcription analysis shows that 46 genes are induced by L‐citrulline. Under the given conditions there appears to be only one pathway for induction with L‐citrulline, and this pathway is completely dependent on the SPS component, Ssy1p, and either of the transcription factors, Stp1p and Stp2p. Besides the effects on amino acid permease genes, an ssy1 and an stp1 stp2 mutant exhibit a number of other transcriptional phenotypes, such as increased expression of genes subject to nitrogen catabolite repression and genes involved in stress response. A group of genes involved in the upper part of the glycolysis, including those encoding hexose transporters Hxt4p, Hxt5p, Hxt6p, Hxt7p, hexokinase Hxk1p, glyceraldehyde 3‐phosphate dehydrogenase Tdh1p and glucokinase (Glk1p), shows increased transcription levels in either or both of the mutants. Also, most of the structural genes involved in trehalose and glycogen synthesis and a few genes in the glyoxylate cycle and the pentose phosphate pathway are derepressed in the ssy1 and stp1 stp2 strains. Copyright © 2004 John Wiley & Sons, Ltd.
Relationship between physical leaf characteristics and growth and survival of polyphagous grasshopper nymphs, Parapodisma subastris (Orthoptera: Catantopidae)
Authors: Miura Kazumi , Ohsaki Naota
Published: June 2004

Common types of plant defense mechanisms are thought to affect the host ranges of polyphagous herbivorous insects, yet few studies have examined the relationship between host plant suitability for polyphagous insects and defense against them. We investigated the suitability of the 19 plant species growing in the habitat of the polyphagous grasshopper, Parapodisma subastris, to determine the relationship between the physical characteristics of leaves and the growth and survival of grasshopper nymphs. We examined leaf toughness, trichome density, and length. Nymph survival was greater on plants with characteristics ranging from soft leaves and dense trichomes to tough leaves and few trichomes than on plants with soft leaves and few trichomes. The exception was Rorippa indica, a plant with soft leaves and few trichomes that uses biotic defense, on which nymph survival was maximal. Higher‐quality plants that share common physical characteristics over families may favor polyphagy by grasshoppers that possess ability to overcome the physical defense easily with their robust mandibles.
Use of the Rydel—Seiffer graduated tuning fork in the assessment of vibration threshold in postherpetic neuralgia patients and healthy controls
Authors: Whitton Tessa L. , Johnson Robert W. , Lovell A.Timothy.
Published: June 2004

Background and aims: Afferent large fibre impairment has been reported as a useful predictor of postherpetic neuralgia (PHN) in patients with acute herpes zoster infection, using an electromechanical device to provide quantitative vibrametry. We aimed to demonstrate a clinically significant increase in vibration threshold in individuals with PHN compared to age‐matched controls, using the portable and affordable Rydel—Seiffer graduated tuning fork.

Methods: We studied 45 PHN subjects aged over 55 years, and 45 age‐matched controls with no history of herpes zoster infection. We excluded subjects with a history of disorders associated with neuropathy or immunocompromise. Measurements were performed at the ulnar styloid process and the head of the first metatarsal on the right side, in a warm room with the subject seated. Readings were taken in triplicate and the data analysed by a repeated measures design.

Results: We observed a significant difference in vibration threshold at both wrist and toe between the PHN and control groups (p<0.001). Age‐stratification of subjects produced an increased and clinically useful difference between the two groups at both sites in subjects between 55 and 70 years (p<0.0001).

Conclusions: We have shown a statistically significant decrease in vibration sensitivity in individuals with PHN aged 55–70 years compared to age‐matched healthy controls, using the Rydel—Seiffer graduated tuning fork. A prospective study of patients with acute zoster infection is needed to determine the sensitivity and specificity of the graduated tuning fork in predicting PHN in patients with acute zoster infection.
Health care providers' orientations towards common low back pain predict perceived harmfulness of physical activities and recommendations regarding return to normal activity
Authors: Houben Ruud M.A. , Ostelo Raymond W.J.G. , Vlaeyen Johan W.S. , Wolters Pieter M.J.C. , Peters Madelon , den Berg Suzanne G.M. Stomp‐van
Published: June 2004

The Pain Attitudes and Beliefs Scale for Physiotherapists (PABS‐PT) differentiates between a biomedical versus a biopsychosocial treatment orientation with regard to common low back pain. This study re‐examined the factor structure and psychometric properties of the PABS‐PT, along with the relationship between PABS‐PT scores and the perceived harmfulness of physical activities and treatment recommendations for common low back pain. Two hundred and ninety‐seven paramedical therapists completed the PABS‐PT and questionnaires measuring related concepts, rated the perceived harmfulness of 41 daily physical activities depicted in photographs and gave recommendations for return to normal activity for three patients with low back pain. Analysis revealed two factors labelled ‘biomedical’ and ‘biopsychosocial treatment orientation’. Furthermore, scores on both factors of the PABS‐PT were related to measures of related concepts (statistically significant Pearson correlation coefficients between 0.30 and 0.65) such as the HC‐PAIRS and a therapist version of the TSK. Regression analyses revealed that both factors were consistent predictors of judgements of the harmfulness of physical activities (PHODA) and of recommendations for return to work and normal activity.
Determination of a high‐precision NMR structure of the minicollagen cysteine rich domain from Hydra and characterization of its disulfide bond formation
Authors: Meier Sebastian , Häussinger Daniel , Pokidysheva Elena , Bächinger Hans Peter , Grzesiek Stephan
Published: June 2004

A high‐precision solution structure of the C‐terminal minicollagen cysteine rich domain of Hydra has been determined using modern heteronuclear and weak alignment NMR techniques at natural isotope abundance. The domain consists of only 24 amino acids, six of which are prolines and six are cysteines bonded in disulfide bridges that constrain the structure into a new fold. The redox equilibrium of the structure has been characterized from a titration with glutathione. No local native structures are detectable in the reduced form. Thus, oxidation and folding are tightly coupled.
A novel CPx‐ATPase from the cadmium hyperaccumulator Thlaspi caerulescens
Authors: Bernard Catherine , Roosens Nancy , Czernic Pierre , Lebrun Michel , Verbruggen Nathalie
Published: June 2004

Thlaspi caerulescens exhibits a unique capacity for cadmium tolerance and accumulation. We investigated the molecular basis of this exceptional Cd2+ tolerance by screening for T. caerulescens genes, which alleviate Cd2+ toxicity upon expression in Saccharomyces cerevisiae. This allowed for the isolation of a cDNA encoding a peptide with homology to the C‐terminal part of a heavy metal ATPase. The corresponding TcHMA4 full‐length sequence was isolated from T. caerulescens and compared to its homolog from Arabidopsis thaliana (AtHMA4). Expression of TcHMA4 and AtHMA4 cDNAs conferred Cd sensitivity in yeast, while expression of TcHMA4‐C and AtHMA4‐C cDNAs encoding the C‐termini of, respectively, TcHMA4 and AtHMA4 conferred Cd tolerance. Moreover, heterologous expression in yeast suggested a higher Cd binding capacity of TcHMA4‐C compared to AtHMA4‐C. In planta, both HMA4 genes were expressed at a higher level in roots than in shoots. However, TcHMA4 shows a much higher constitutive expression than AtHMA4. Our data indicate that HMA4 could be involved in Cd2+ transport and possibly in the Cd hyperaccumulation character.
Identification of a glutamine residue essential for catalytic activity of aspergilloglutamic peptidase by site‐directed mutagenesis
Authors: Yabuki Yutaka , Kubota Keiko , Kojima Masaki , Inoue Hideshi , Takahashi Kenji
Published: June 2004

Aspergilloglutamic peptidase (AGP, formerly called aspergillopepsin II) from Aspergillus niger var. macrosporus is a unique acid protease recently classified to the peptidase family G1. Our previous study using site‐directed mutagenesis on the glutamic and aspartic acid residues of AGP conserved among the G1 family suggested that Glu219 and Asp123 (numbering in the preproform) are important for catalytic activity. However, the Asn mutant of Asp123 retained weak but significant activity and therefore it was unclear whether it is an active site residue. In this study, we performed site‐directed mutagenesis on all the other hydrophilic residues including Gln, Asn, Ser, Thr, and Tyr, conserved in this family to screen other residues that might be essential for catalytic function, and found that mutations of only Gln133 resulted in almost complete loss of enzymatic activity without change in the native conformation of the enzyme. Meanwhile, the 3D structure of scytalidoglutamic peptidase, a homologue from Scytalidium lignicolum, has been reported, indicating that Glu136 and Gln53 (the counterparts of Glu219 and Gln133 in AGP) form a catalytic dyad. Therefore, the results obtained in this and our previous studies provide with complementary evidence for the definitive conclusion on the catalytic function of the Glu/Gln dyad in glutamic peptidases.
The effect of growth at low temperature on the activity and expression of the uncoupling protein in Acanthamoeba castellanii mitochondria
Authors: Jarmuszkiewicz Wieslawa , Antos Nina , Swida Aleksandra , Czarna Malgorzata , Sluse Francis E
Published: June 2004

Mitochondria of amoeba Acanthamoeba castellanii, a non‐photosynthetic soil amoeboid protozoon, possess an uncoupling protein (AcUCP) that mediates free fatty acid‐activated proton re‐uptake dissipating the proton electrochemical gradient built up by respiration. The present study provides the first evidence that UCP could be a cold response protein in unicellulars. In mitochondria isolated from an amoeba batch culture grown temporarily at low temperature (6 °C), the content of AcUCP was increased and correlated with an increase in the linoleic acid (LA)‐stimulated UCP‐mediated carboxyatractyloside‐resistant state 4 respiration, as compared to a control culture (routinely grown at 28 °C). Moreover, the cytochrome pathway activity was found to be insensitive to the cold exposure of amoeba cells, as indicated by respiration and membrane potential measurements as well as by an absence of change in the adenine nucleotide translocator and cytochrome oxidase expression levels. Furthermore, in mitochondria from the low‐temperature‐grown cells, at fixed LA concentration, the increased contribution of AcUCP activity to total mitochondrial phosphorylating respiration accompanied by lower coupling parameters was found, as was confirmed by calculation of this contribution using ADP/O measurements.
Polymerization of nucleotide‐free, GDP‐ and GTP‐bound cell division protein FtsZ: GDP makes the difference
Authors: Huecas Sonia , Andreu José Manuel
Published: June 2004

Stable, more than 98% nucleotide‐free apo‐FtsZ was prepared from purified Methanococcus jannaschhi FtsZ. This facilitates the study of the functional mechanisms of this FtsZ, an assembling GTPase, which shares a common fold with eukaryotic tubulin. Apo‐FtsZ underwent cooperative magnesium‐induced polymerization with a similar critical concentration and morphology related to that of reconstituted GTP‐bound FtsZ, suggesting that the binding of GTP contributes insignificantly to the stability of the FtsZ polymers. On the other hand, reconstituted GDP‐FtsZ polymerized with a larger critical concentration than GTP‐FtsZ, indicating that GDP binding destabilizes FtsZ polymers. Upon GTP hydrolysis by FtsZ polymers, in the absence of a continued GTP supply and under macromolecular crowding conditions enhancing FtsZ polymerization, the straight GTP polymers disappeared and were replaced by characteristic helically curved GDP‐bound polymers. These results suggest that the roles of GTP binding and hydrolysis by this archaeal FtsZ are simply to facilitate disassembly. In a physiological situation in GTP excess, GDP‐bound FtsZ subunits could again bind GTP, or trigger disassembly, or be recognized by FtsZ filament depolymerizing proteins, allowing the Z‐ring dynamics during prokaryotic cell division.
Cell type‐specific regulation of calmodulin 2 expression by mutant p53
Authors: Knaup K.X , Roemer K
Published: June 2004

To identify genes that are stimulated by oncogenic forms of mutant p53, we studied, by microarray analysis and PCR‐select subtractive hybridization, gene expression changes in human wild‐type (wt) p53‐negative immortal 041 fibroblasts infected to stably express p53 mutant 175H. In contrast to the wt p53 transactivator, 175H induced only few and weak, gene expression changes. We report here the stimulation of calmodulin 2 (CaM 2), but not CaM 1 or 3, gene expression specifically in 041 cells. The stimulation of the CaM 2 promoter required the 5′ untranslated sequences as well as the integrity of the transactivation domain of 175H. However, direct binding of 175H to the 5′UT in vitro could not be demonstrated.
A P53 target gene, PIG11, contributes to chemosensitivity of cells to arsenic trioxide
Authors: Liang Xiao-Qiu , Cao En-Hua , Zhang Yan , Qin Jing-Fen
Published: June 2004

The tumor suppressor p53 regulates the expression of various genes that promote apoptosis. PIG11 (P53‐induced gene 11), also referred to as TP53I11 (tumor protein p53 inducible protein 11), is a direct p53 target gene. Recent data demonstrated that PIG11 was up‐regulated markedly in arsenic trioxide induced apoptosis by DDRT‐PCR, suggesting a new class of p53 target genes that sensitize cells to the effects of chemotherapeutic agents. In this study, through the construction of a recombinant GFP‐PIG11 expression vector and transfection of HEK293 cells with GFP or GFP‐PIG11, the role of PIG11 in apoptosis was analyzed. Results demonstrated that the percentage (11.38%) of apoptotic cells with GFP‐PIG11 transfection was higher than that (7.28%) of with only GFP transfection (P<0.05). At 24 h after 1 μM of arsenic trioxide treatment, apoptotic cells exhibited a significant increase in the expression of GFP‐PIG11 (36.67% ± 2.78), in contrast, 10.50% ± 2.03 only GFP and 5.25% ± 0.96 vehicle control (P<0.01). In addition, we showed that intracellular content of reactive oxygen species (ROS) was 9.66 ± 0.52 in GFP‐PIG11 transfection, higher than 5.21 ± 0.08 in GFP only and 5.99 ± 0.45 in vehicle control (P<0.01). The above results suggest that overexpression of PIG11 could induce cell apoptosis in the low levels and enhanced the apoptotic effects of arsenic trioxide. The process could be involved in intracellular generation of ROS.
Stem/progenitor cells in the postnatal inner ear of the GFP‐nestin transgenic mouse
Authors: Lopez Ivan A. , Zhao Paul M. , Yamaguchi Masahiro , de Vellis Jean , Espinosa‐Jeffrey Araceli
Published: June 2004

Nestin promoter‐GFP (green fluorescent protein) transgenic mice were used to determine the presence of stem/progenitor cells in the mouse inner ear. We examined the inner ear of mice at the following postnatal days (P): P0, P4, P5, P15 and P60. Hair cells stereocilia were identified with the use of the histochemical marker phalloidin. Whole endorgans or cryosections were analyzed under epi‐fluorescent or confocal microscopy. From P0 to P5, GFP expressing cells were found in the vestibular sensory epithelia of the macula utricle, but not in the crista ampullaris. Cells within the stroma (tissue underneath the sensory epithelia), utricle, and crista were also GFP‐positive. Satellite cells in the vestibular ganglia were GFP‐positive, while vestibular ganglia neurons were not. In the organ of Corti, GFP signal was found in inner border and inner phalangeal cells that surround the inner hair cells (GFP‐negative), Dieters cells and cells in the great epithelial ridge. Outer hair cells were mildly positive for GFP. Satellite cells in the spiral ganglia were GFP‐positive, while spiral ganglia neurons were not. Similar GFP expression was found in the vestibule and cochlea of animals at P15, however, outer hair cells showed no GFP expression. The inner ear of P60 animals contained moderate GFP expression in the stroma of the crista ampullaris and utricle, but not within the sensory epithelia. In the organ of Corti, moderate GFP expression was found in a few Deiters cells. The present data indicates that the expression of nestin in the mouse inner ear is developmentally regulated; yet in the adult inner ear there are some nestin expressing cells, suggesting an intrinsic repair potential, although to a more limited extent than during early post‐natal life.
Effect of Wrist Position on Power Grip and Key Pinch Strength Following Carpal Tunnel Decompression
Authors: MATHUR K. , PYNSENT P. B. , VOHRA S. B. , THOMAS B. , DESHMUKH S. C.
Published: June 2004

Power grip and thumb key pinch strength were measured pre- and immediately postoperatively in 30 patients with carpal tunnel syndrome while the wrist was in flexion and extension. The carpal tunnel decompression was performed under local infiltration with 1% lignocaine. Grip strength decreased more in wrist flexion than in wrist extension. No difference was found in thumb pinch strength. The authors conclude that some of the immediate postoperative loss of grip strength in wrist flexion can be attributed to prolapse of flexor tendons out of the carpal tunnel in this position.
Arthrodesis of Ring Finger and Little Finger Metacarpal Bases for Little Finger Carpometacarpal Joint Arthritis
Authors: BAIN GREGORY I. , UNNI P.M. RAGHAVAN , MEHTA JANAK A. , EAMES MICHAEL H.A.
Published: June 2004

Five patients with localized little finger carpometacarpal arthritis were treated by excision of the little finger metacarpal base and arthrodesis of the little and ring metacarpals. A dorsal periosteal/capsular flap was used as an interposition graft. All patients achieved significant pain relief, good cosmesis and satisfactory grip strength. All returned to activities of daily living. This procedure, the Dubert procedure, is indicated for localized pathology of the hamate-little finger metacarpal joint. It has theoretical advantages over arthrodesis and resection or interposition arthroplasty as it preserves little finger length, rotation and alignment and maintains some mobility of the transverse carpal arch and the little finger ray.
Instrumented measurement of in vivo anterior—posterior translation in the canine knee to assess anterior cruciate integrity
Authors: Lopez Mandi J. , Hagquist William , Jeffrey Susan L. , Gilbertson Sara , Markel Mark D.
Published: June 2004

This study was designed to objectively quantify in vivo anterior–posterior canine knee translation relative to anterior cruciate ligament (ACL) integrity. Tibial translation was determined in one knee of 43 crossbreed hounds from radiographs performed while a set anterior and then posterior force was applied to the tibia using a custom designed device. The total (TTT), anterior (ATT), and posterior (PTT) tibial translation were measured (absolute) and normalized to the width of the tibia (normalized). Absolute and normalized TTT was significantly greater in ruptured ACL knees than in partially disrupted (PD) ACL knees, which were significantly greater than in intact ACL knees. ATT and PTT was significantly greater in ruptured ACL knees than in PD or intact ACL knees, which were not significantly different. The sensitivity and specificity of normalized TTT to distinguish knees with intact from PD ACLs were both 100%. Normalized TTT to distinguish knees with PD from ruptured ACLs had a sensitivity and specificity of 100% and 92%, respectively. Intra‐ and inter‐observer intra‐class correlation coefficients were 0.84 or higher for all translations. This precise non‐invasive technique to assess canine knee translational stability and ACL integrity permits repetitive, objective measurements for diagnostic use and to assess therapeutic intervention efficacy. © 2004 Pulished by Elsevier Ltd. on behalf of Orthopaedic Research Society.
The Adverse Consequences of the Politics of Agency Design for Presidential Management in the United States: The Relative Durability of Insulated Agencies
Authors: LEWIS DAVID E.
Published: June 2004

The US Congress has often sought to limit presidential influence over certain public policies by designing agencies that are insulated from presidential control. Whether or not insulated agencies persist over time has important consequences for presidential management. If those agencies that persist over time are also those that are the most immune from presidential direction, this has potentially fatal consequences for the president's ability to manage the executive branch. Modern presidents will preside over a less and less manageable bureaucracy over time. This article explains why agencies insulated from presidential control are more durable than other agencies and shows that they have a significantly higher expected duration than other agencies. The conclusion is that modern American presidents preside over a bureaucracy that is increasingly insulated from their control.
The Shrinking Middle in the US Congress
Authors: FLEISHER RICHARD , BOND JOHN R.
Published: June 2004

The virtual disappearance of moderate and cross-pressured members from the US Congress is analysed in this article. There were substantial numbers of these partisan non-conformists in both parties and in both chambers until the early 1980s when the middle began to shrink. This trend continued and accelerated in the 1990s. Partisan non-conformists disappeared through replacement and conversion. When moderate and cross-pressured members left Congress, their replacements were much more likely to be mainstream partisans in the 1980s and 1990s than they had been in earlier decades. The occurrence of some type of conversion (a shift towards the party's ideological mainstream or a party switch) is also much more common in recent decades. We present evidence that the shrinking middle in Congress resulted from electoral changes.
Representing Diversity
Authors: GOODIN ROBERT E.
Published: June 2004

‘Mirror representation’ or a ‘politics of presence’ presupposes relatively modest levels of diversity among those being represented. If the groups to be represented are too numerous, internally too heterogeneous or too cross-cutting, too many representatives will be required for the assembly to remain a deliberative one where ‘presence’ can have the effects its advocates desire. In those circumstances, what is being represented ought be conceptualized as the ‘sheer fact of diversity’ rather than ‘all the particularities of the diversity among us’. The appropriate response to that is legislative reticence.
Civic Generation: Policy Feedback Effects of the GI Bill on Political Involvement over the Life Course
Authors: METTLER SUZANNE , WELCH ERIC
Published: June 2004

One of the chief explanations for the decline of social capital in the United States is the passing of the ‘civic generation’, those who came of age during the Depression and the Second World War. These Americans experienced greater government largesse than previous generations, yet we know little about how public programmes influenced their subsequent involvement in public life. This article draws on policy feedback theory to examine how the educational benefits of the GI Bill, through which 7.8 million Second World War veterans attended college or gained vocational training, affected recipients' political participation across three time periods, from 1950 to 1998. We find that initially, interpretive effects of programme implementation produced increased levels of participation among users generally. Later on, resource effects enhanced participation rates selectively, with the strongest effects among those who had attained the highest levels of education. Overall, the study illustrates distinct mechanisms, timing and sequencing through which public policy can shape the interests and capacities of programme recipients to engage in democratic participation.
Turnout, Participation and Legitimacy in Post-Devolution Wales
Authors: SCULLY ROGER , JONES RICHARD WYN , TRYSTAN DAFYDD
Published: June 2004

Low levels of voter turnout in the first election to the National Assembly for Wales in May 1999 brought into question both the ability of devolution to revitalize representative democracy and the legitimacy of the Assembly itself. But drawing wider implications from turnout requires that we understand why electoral abstention was so widespread. We examine three hypotheses about voter turnout in 1999: that non-participation simply reflected a general apathy towards politics; that it was based on a specific apathy towards the new Assembly; or that low voter turnout reflected antipathy towards an unwanted political institution. We find support for the first two hypotheses, but little evidence for the third. Devolution has failed to engage the interest and support of many in Wales, but low turnout has not been prompted by fundamental antagonism to the devolved institution among the Welsh electorate.
Mistaken Identity: Testing the Clash of Civilizations Thesis in Light of Democratic Peace Claims
Authors: HENDERSON ERROL A.
Published: June 2004

Cultural identity has become prominent in studies of world politics in the post-Cold War era. First, a growing literature in world politics has emerged that focuses on the impact of social culture, broadly conceived as the shared religious, racial or ethnolinguistic characteristics of a society. The significance of this aspect of culture is epitomized in studies focusing on ‘ethnic conflicts’, ‘ethnic security dilemmas’, and most prominently in Huntington's ‘clash of civilizations’ thesis, which suggests, among other things, that shared civilization membership is the fulcrum upon which post-Cold War era world politics rests. Secondly, the impact of political culture, broadly conceived as the shared norms and institutions guiding political behaviour in a society, has become increasingly salient, as evidenced by the bourgeoning literature on the democratic peace thesis, which posits that the extent to which a state (or pair of states) is democratic is a major determinant of its war-proneness. Adherents of this view argue either that although democracies are just as war-prone as non-democracies they rarely fight other democracies, or that democracies are more peaceful than
non-democracies, in general.
Temporal markers of prosodic boundaries in children's speech production
Authors: Dankovičová Jana , Pigott Kathryn , Wells Bill , Peppé Sue
Published: June 2004

It is often thought that the ability to use prosodic features accurately is mastered in early childhood. However, research to date has produced conflicting evidence, notably about the development of children's ability to mark prosodic boundaries. This paper investigates (i) whether, by the age of eight, children use temporal boundary features in their speech in a systematic way, and (ii) to what extent adult listeners are able to interpret their production accurately and unambiguously. The material consists of minimal pairs of utterances: one utterance includes a compound noun, in which there is no prosodic boundary after the first noun, e.g. ‘coffee-cake and tea’, while the other utterance includes simple nouns, separated by a prosodic boundary, e.g. ‘coffee, cake and tea’. Ten eight-year-old children took part, and their productions were rated by 23 adult listeners. Two phonetic exponents of prosodic boundaries were analysed: pause duration and phrase-final lengthening. The results suggest that, at the age of 8, there is considerable variability among children in their ability to mark phrase boundaries of the kind analysed in the experiment, with some children failing to differentiate between the members of the minimal pairs reliably. The differences between the children in their use of boundary features were reflected in the adults' perceptual judgements. Both temporal cues to prosodic boundaries significantly affected the perceptual ratings, with pause being a more salient determinant of ratings than phrase-final lengthening.
Ibibio
Authors: Urua Eno-Abasi E.
Published: June 2004

Ibibio is a Lower Cross (Delta Cross, Cross River, New Benue-Congo, Niger-Congo) language spoken mainly in Akwa Ibom State and in parts of Cross River State, both located in the southeastern part of Nigeria. The number of speakers is estimated at about four million (Essien 1991). Previous work on Ibibio phonetics includes Connell (1992, 1994, 1995) and Urua (1996/97, 2000, 2002). The variety presented here is spoken in Uruan area and Uyo, the capital city of Akwa Ibom State and the recording is that of the author, a female university teacher from Uruan.
Lheidli intervocalic consonants: phonetic and morphological effects
Authors: Bird Sonya
Published: June 2004

Several researchers have noted that intervocalic consonants are unusually long in Navajo (Sapir & Hoijer 1967, Young & Morgan 1987, McDonough & Ladefoged 1993). This paper explores intervocalic consonant duration in the Lheidli dialect of Dakelh (Carrier) in order to determine whether the long intervocalic consonants found in Navajo are characteristic of other Athabaskan languages as well. It is shown that Lheidli intervocalic consonants are substantially longer overall than (a) consonants in other positions within Lheidli, (b) vowels within Lheidli, and (c) singletons and geminates in other non-Athabaskan languages. Furthermore, intervocalic consonant duration is at least in part a function of morphological structure, with intervocalic consonants lengthening to signal a stem morpheme boundary. The data presented here provide new evidence for the existence of a language-specific phonetic component of grammar as well as for the interaction between phonetics and morphology.
Italian
Authors: Rogers Derek , d'Arcangeli Luciana
Published: June 2004

Italian is spoken in Italy, in parts of Switzerland and Croatia, and in diaspora communities across the world. The standard language as spoken in Italy has three main regional varieties: Northern, Central and Southern. But contemporary ‘mainstream Italian’ – not following the standard in all respects – appears to be a variety under construction by speakers wishing to give themselves a national appeal, a process driven by the media and by workplace mobility. Our speaker is representative of this group. She is a woman in her thirties who was brought up in a middle-class household in Rome, and has travelled extensively in Italy and abroad. She aims at a cultivated accent with no strong regional features, sometimes called a ‘RAI’ accent (RAI /rai/ is the national broadcaster). The style she uses is a somewhat coloured ‘storytelling’ style.
Glaciological characteristics of Institute Ice Stream using remote sensing
Authors: SCAMBOS TED , BOHLANDER JENNIFER , RAUP BRUCE , HARAN TERRY
Published: June 2004

We assess the ice flow of Institute Ice Stream (IIS; 81.5°S, 75°W) and the adjacent Ronne Ice Shelf using satellite images and geophysical parameters from recent continent-wide compilations. Landsat image pairs from the 1980s and 1990s are used to determine ice velocity. Peak speed is 398 ± 10 m a−1. Several mappings using images spanning an eleven-year period indicate this speed and the pattern of ice flow throughout the mapped portion of the stream is constant to within ± 20 m a−1. Combining catchment extent (141 700 km2) with surface accumulation, mass input to IIS is 25.1 ± 2 Gt a−1. Mean ice thickness across the grounding line is 1177 m. Mass flux to the Ronne Ice Shelf, determined from these values and our velocity profile, is 22.7 ± 2 Gt a−1. Topographic mapping using photoclinometry, coupled with ice thickness and ice velocity, permits an assessment of driving force versus flow speed. This indicates wide variations in basal resistance. Despite evidence of present-day near-balance and constant speed in the ice stream trunk, a recent change in outflow is implied by folding of shelf streaklines near Korff Ice Rise. This may be a result of changing shelf thickness or erosion of Doake Ice Rumples.
Aliphatic and polycyclic aromatic hydrocarbons in surface sediments in Admiralty Bay, King George Island, Antarctica
Authors: MARTINS C.C. , BÍCEGO M.C. , TANIGUCHI S. , MONTONE R.C.
Published: June 2004

Aliphatic (AHs) and polycyclic aromatic hydrocarbons (PAHs) concentrations were measured in marine surface sediments around the Brazilian station in Admiralty Bay, during the summers of 1997/98 and 1999/2000 using GC-FID and GC-MS. Total aliphatic hydrocarbons ranged from 0.15 to 13.28 μg·g−1 (dry weight) while n-alkanes varied between 0.10 and 9.63 μg·g−1. The highest concentrations were obtained at the sewage outfall, with decreasing levels away from the outfall. The distribution of n-alkanes showed significant quantities of long chain n-alkanes (n-C22 to n-C34) at sites near the Brazilian station that may be attributed to the station activities. A short chain n-alkanes sequence (n-C12 to n-C21) associated with diesel fuel arctic (DFA) was present in all the samples. Total PAHs varied from 9.45 to 270.5 ng·g−1. The higher PAHs level and the presence of an unresolved complex mixture only in sediment from the sewage outfall is an indication of oil contamination at this location. A slight increase in PAHs near the Brazilian station since 1993 may be attributed to an increase in the number of staff over recent years. In general, the concentration of AHs and PAHs was similar to that found in other Antarctic areas.
Minimum area assessment and different sampling approaches for the study of vegetation communities in Antarctica
Authors: CANNONE NICOLETTA
Published: June 2004

Antarctic vegetation offers excellent opportunities for the study of dynamics and biodiversity of natural systems with high environmental sensitivity. This paper addresses the methodological and technical aspects for the minimum area (MA) assessment (the smallest area which adequately represents community composition) and compares three different sampling approaches for vegetation at Jubany, King George Island. Five target communities, among the most widespread and representative of a wide range of floristic richness and dynamism, were selected through the phytosociological study. The minimum area, determined from four methods, ranged between 2 and 24 m2. Similar values have been obtained for the polar desert vegetation of the Northern Hemisphere. Three sampling approaches were tested in the five communities: the phytosociological survey with 100 cm grid, the phytosociological survey with 5 cm grid, the point intercept with 10 cm grid. To achieve comparable data a standard plot, satisfying the MA requirements of all the communities, has been adopted for all the study sites. The results indicate that the integration of the three methods provides the highest level of information, especially in respect of limitations on field sampling and logistics.
Coupling mixing and photophysiological response of Antarctic plankton: a Lagrangian approach
Authors: CIANELLI DANIELA , D'ALCALÀ MAURIZIO RIBERA , SAGGIOMO VINCENZO , ZAMBIANCHI ENRICO
Published: June 2004

An individual-based model is presented which describes the spatial and temporal evolution of phytoplankton growth in terms of a Lagrangian ensemble of cells affected by various physical and biological forcing factors. The motion of cells develops according to a turbulent velocity field which simulates the Antarctic mixed layer during the summer. The cell growth is a function of the irradiance regime, nutrient availability and the vertical position of the individual with respect to the other cells (in order to evaluate the self-shading effect). The values of photosynthetic parameters used to simulate the photophysiological response of the organisms are derived from measurements collected in the Ross Sea. In contrast to previous individual-based descriptions, all the physical and biological processes involved are explicitly reproduced in their dynamical features. Coupling different mixing levels with photoacclimation strategies leads to a wide range of photophysiological responses which underline the role of individual physiological histories in determining the growth of the population as a whole. Simulated photosynthetic parameters, chlorophyll a concentrations and integrated primary production correspond closely to in situ data and confirm that photoacclimation to low irradiance and strong mixing regimes may be considered as crucial factors in the photosynthetic performance of Antarctic phytoplankton.