bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spindle structure of the stress tensor of chemical bond
Authors: Tachibana Akitomo 
Published: September 2004

AbstractCovalent bond describes electron pairing in between a pair of atoms and molecules. In the current paper, the space is partitioned in mutually disjoint regions by using new concept of the electronic drop region RD, atmosphere region RA, and the interface S [Tachibana, A. J Chem Phys 2001, 115, 3497]. The covalent bond formation is then characterized by a new concept of the spindle structure. The spindle structure is a geometrical object of a region where principal electronic stress is positive along a line of principal axis of the electronic stress that connects a pair of the RDs of atoms and molecules. Using virial theorem of the rigged quantum electrodynamics (QED), a new energy density partitioning scheme is obtained using the kinetic energy densities. In the current paper, a concise judgment condition to identify the given unknown locality as a spindle structure of a covalent bond is formulated in the frame of the nonrelativistic limit of QED. A physical interpretation of the local dynamics of the chosen spindle structure is also guaranteed at the same time as the judgment of the generalized chemical reactivity in terms of the physical quantum mechanical law that is hierarchic and localized. A general frame to elucidate a feature structure and the character of the classification concerning the expression of the internal symmetry of chemical reaction to the chosen spindle structure class is given in a unified way. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
The detection of piroxicam, tenoxicam and their metabolites in equine urine by electrospray ionisation ion trap mass spectrometry
Authors: McKinney Andrew R. , Suann Craig J. , Stenhouse Allen M. 
Published: September 2004

AbstractAn investigation has been conducted into the metabolism and urinary excretion of orally administered piroxicam and tenoxicam in the horse. The major component detected in urine after the administration of piroxicam was 5′‐hydroxypiroxicam, which was detectable up to 24 h post‐administration. Unchanged piroxicam was present only as a minor component. In contrast, unchanged tenoxicam was the major component observed after the administration of tenoxicam, being detectable for 72 h post‐administration, while 5′‐hydroxytenoxicam was a minor component. Phase II β‐glucuronide conjugation in each case was found to be negligible. The ion trap mass spectral characteristics of piroxicam, tenoxicam, 5′‐hydroxypiroxicam and 5′‐hydroxytenoxicam under electrospray ionisation conditions were examined in some detail. Copyright © 2004 John Wiley & Sons, Ltd.
Development of a methodology for XPS curve‐fitting of the Si 2p core level of siloxane materials
Authors: O'Hare Lesley‐Ann , Parbhoo Bhukan , Leadley Stuart R. 
Published: September 2004

AbstractA procedure for obtaining reliable binding energies in XPS for the various chemical states of silicon has been described in the literature for some organosilicon compounds. This manuscript describes further development of this work by the analysis of siloxane compounds that model complex polysiloxane systems. The use of accurate and restrained binding energies will allow greater confidence in the curve‐fitting of the Si 2p core level of industrially relevant coatings, which are typically featureless. The binding energy of a siloxy unit is known to increase when an oxygen atom replaces an alkyl group attached to the silicon atom. However, whereas previous work had estimated the binding energy shift between the M [(CH3)3SiO1/2], D [(CH3)2SiO2/2], T [(CH3)SiO3/2] and Q [SiO4/2] environments of silicon to be equal, or decreasing, this work has demonstrated a non‐linear increase in binding energy with increasing oxygen substitution. Copyright © 2004 John Wiley & Sons, Ltd.
GM Football – Eingangspavillon des Headquarters von General Motors in Detroit
Authors: Dinort Ralf , Lemke Stefan 
Published: September 2004

AbstractDer Artikel beschreibt Konstruktion, Herstellung und Montageplanung eines gläsernen Pavillons über einem elliptischen d. h. footballförmigen Grundriß von 30 m Länge und 10 m Breite. Die punktgehaltene Verglasung wird dabei in den 14 m hohen Fassaden von einem Seilnetz gestützt, welches in vertikaler Richtung vom Rand des räumlichen fischbauchförmigen Hauptträgers zum Boden spannt. In horizontaler Richtung verlaufen die Seile zwischen den seilumspannten Stützen des Hauptträgers. Von besonderer Bedeutung war bei der Planung dieses biaxial gekrümmten Seiltragwerkes die Detaillierung nicht nur im Hinblick auf sthetik, sondern insbesondere auf Montierbarkeit und Toleranzausgleich, sowie die Entwicklung eines schlüssigen Montagekonzeptes und der dazugehörigen Berechnungen.
Stabwerke auf Freiformflächen
Authors: Stephan Sören , Sánchez‐Alvarez Jaime , Knebel Klaus 
Published: September 2004

AbstractBei einigen bekannten Bauwerken der letzten Jahre, beispielsweise bei der DG‐Bank in Berlin (Architekt: Frank Gehry), dem Arts Center in Singapur (Architekt: Vikas Gore), dem Britischen Museum in London (Architekt: Norman Foster) oder kürzlich den Glasdächern über der Zentralachse und dem Servicezentrum der Neuen Messe in Mailand (Architekt: Massimiliano Fuksas), sind Freiformflächen zunehmend für Gebäudehüllen eingesetzt worden. Der folgende Aufsatz befaßt sich mit den geometrischen Aspekten und den mit der praktischen Umsetzung dieser Bauarten verbundenen Problemen. Es werden insbesondere eine Vielzahl verschiedener Knotenkonstruktionen vorgestellt, ohne die Stabstrukturen für Freiformflächen nicht realisierbar wären.
Preamble computation in automated test case generation using constraint logic programming
Authors: Colin Séverine , Legeard Bruno , Peureux Fabien 
Published: September 2004

AbstractBZ‐Testing‐Tools (BZ‐TT) is a tool‐set for automated model‐based test case generation from B abstract machines and Z specifications. BZ‐TT uses boundary testing as well as cause–effect testing on the basis of the formal model. It has been used and validated on several industrial case studies in the domain of critical software: in particular for smart card applications and automotive embedded systems. The main idea of BZ‐TT is to compute a boundary goal for each effect of the operations of the model and then to compute a preamble sequence of operations to place the system under test in such a state that satisfies the goal.In this paper, the preamble computation search strategies used in BZ‐TT are presented. More precisely, two algorithms based respectively on forward chaining and backward chaining are compared. These algorithms both use a customized set constraint solver, which is able to animate the formal model. These algorithms differ, however, in their capacity to reach the boundary goals efficiently. The results of applying the tools to an industrial windscreen wiper controller application are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Discursive identity: Assimilation into the culture of science and its implications for minority students
Authors: Brown Bryan A. 
Published: September 2004

AbstractThis study examined how, in some instances, participation in the cultural practices of high school science classrooms created intrapersonal conflict for ethnic minority students. Discourse analysis of videotaped science classroom activities, lectures, and laboratories was the primary methodology employed for analyzing students' discursive identity development. This analysis demonstrated differential appropriation of science discourse as four significant domains of discursive identities emerged: Opposition status, Maintenance status, Incorporation status, and Proficiency status. Students characterized as Opposition Status avoided use of science discourse. Students who exhibited Maintenance Status illustrated a commitment to maintaining their normative discourse behavior, despite a demonstrated ability to appropriate science discourse. Students characterized as Incorporation Status made active attempts to incorporate science discourse into their normative speech patterns, while Proficiency Status students demonstrated a fluency in applying scientific discursive. Implications for science education emerging from the study include the illumination of the need to make the use of specific scientific discourse an explicit component of classroom curriculum. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 810–834, 2004
Interaction between halogenated aromatic compounds in the Ah receptor signal transduction pathway
Authors: Chen Guosheng , Bunce Nigel J. 
Published: September 2004

AbstractMany toxic and biochemical responses to halogenated aromatic compounds (HACs) such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo‐p‐dioxins (PCDDs) are mediated through the aryl hydrocarbon receptor (AhR), which is an intracellular cytosolic target for HACs. Environmental exposure to HACs almost always involves complex mixtures of congeners, some of which can antagonize the action of potent HACs such as 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD). In this work we studied TCDD and representative PCB congeners, alone and in mixture, for their effect on CYP1A gene transcription and protein levels in primary rat hepatocytes. Together with our previous work, our results suggest that formation of the Ah receptor‐ligand‐DRE (dioxin response element) complex is the principal point of divergence in the mechanism between an AhR agonist and an AhR antagonist. The coplanar PCBs 77 and 126 and the mono‐ortho PCB 156 were full agonists toward CYP1A1 gene transcription and CYP1A protein levels, showing typical additive behavior with TCDD to the target molecule AhR. In contrast, the nonplanar PCB 153 antagonized the action of TCDD, even at concentrations that occupied a significant fraction of AhR molecules. Competitive inhibition explains the commonly reported decrease of ethoxyresorufin‐O‐deethylase (EROD) activity when PCBs are present in high concentrations and the antagonism of PCBs to the EROD activity of TCDD. The result is that Western blotting offers a much more reliable measure of CYP1A protein concentration than does the EROD assay, despite the greater convenience of the latter. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 480–489, 2004.
Management of Pseudomeningocele Following Neurotologic Procedures
Authors: Mehendale Neelesh H. , Samy Ravi N. , Roland Peter S. 
Published: September 2004

OBJECTIVESA pseudomeningocele results from the escape of cerebrospinal fluid through a dural defect with trapping of subarachnold fluid in surrounding soft tissue. The present study evaluates the incidence of pseudomeningocele following neurotologic procedures and delineates an algorithm for management.METHODSA retrospective review of 375 consecutive patients undergoing neurotologic procedures at a single institution identified 17 patients with the postoperative complication of pseudomeningocele.RESULTSThe incidence of pseudomeningocele formation was 4.5% in the present study. Fourteen pseudomeningoceles resolved with nonoperative management including pressure dressing, bed rest, and lumbar spinal drainage. Three patients failed nonoperative management and required surgical procedures for resolution. All patients ultimately had resolution of their pseudomeningocele.CONCLUSIONSkull‐base pseudomeningoceles occur as a complication following neurotologic procedures and can cause complications as they enlarge. The majority of these cases can be dealt with in a nonsurgical manner, but those failing to respond to conservative management should be considered for surgical intervention.
Non‐immunostimulatory nonviral vectors
Authors: Liu Feng , Shollenberger Lisa M. , Huang Leaf 
Published: September 2004

ABSTRACTThe vectors for gene delivery are usually classified as viral and nonviral vectors. While the viral vectors are very efficient in transducing cells, safety concerns regarding their use in humans make nonviral vectors an attractive alternative. Among the nonviral vectors, the lipoplexes (complexes of cationic liposome/pDNA) are the most studied and represent the most promising approaches for human clinical trials. However, an inflammatory response is invariably associated with administration of the lipoplexes, which must be avoided in the clinical application. Here, we have successfully developed a nonimmunostimulatory vector for gene therapy. The vector possesses dual functions of: 1) efficiently delivering a gene to target cells and 2) codelivering DNA and inflammatory suppressors into the immune cells where the released suppressor can inhibit cytokine production. The inflammatory suppressors successfully delivered by the vector included glucocorticoids, a nonsteroidal anti‐inflammatory drug (NSAID), an NF‐κB inhibitor, and a natural compound from an herbal medicine. Intravenous injection of the vector dramatically suppressed the cytokine production induced by CpG motif pDNA, including TNF‐α, IL‐12 and IFN‐γ. This new gene vector has a great potential in clinical gene therapy. Another potential use of the vector is codelivery of an enhancer candidate, acting at the transcriptional and translational levels to improve the efficiency of gene transfer by the nonviral vector. Moreover, the unique feature of this vector is that it can be used as an easy and powerful tool for in vivo screening of anti‐inflammatory drugs.
Parasite infectivity and immunity to Plasmodium falciparum gametocytes in Gambian children
Authors: Drakeley C. J. , Eling W. , Teelen K. , Bousema J. T. , Sauerwein R. , Greenwood B. M. , Targett G. A. T. 
Published: September 2004

SUMMARY Immunity to the sexual stages of Plasmodium falciparum can be induced during natural infections. Characterization of this immunity may facilitate the design of a transmission‐blocking vaccine (TBV). This study aimed to assess the prevalence and serological correlates of functional transmission‐blocking immunity in Gambian children (aged 1–4 years old) who were P. falciparum gametocyte carriers. Serological assays showed 100% response to fixed, whole parasites but only 42% to live gametes. Responses to the antigens Pfs230 and Pfs48/45 were 54·1% and 37·3%, respectively, in an IgG1 ELISA. 14/55 sera were capable of reducing the infectivity of laboratory isolate NF54 in a standard membrane‐feeding assay (SMFA). This activity was strongly correlated with IgG1 responses to Pfs48/45 (r = 0·49, P < 0·001) and to a serological reaction with epitopes of the same molecule (r = 0·38, P = 0·003). A weaker correlation was observed with IgG1 to Pfs230 (r = 0·29, P = 0·03). In direct membrane feeding assays (DMFA) with autologous isolates, sera from 4/29 children showed transmission‐blocking activity. There was no correlation with serological assays and the DMFA or between the SMFA and DMFA. This may be caused by variation in sexual stage antigens and/or alternative modes of transmission‐blocking immunity, both of which have implications for vaccine implementation.
First observation of herpes‐like virus particles in northern pike, Esox lucius L., associated with bluespot‐like disease in Ireland
Authors: Graham D A , Curran W L , Geoghegan F , McKiernan F , Foyle K L 
Published: September 2004

AbstractCircular whitish granular lesions, 5–12 mm in diameter, were observed on the skin and fins of a wild northern pike, Esox lucius, caught in a lake in the Republic of Ireland. Histological examination of the lesions revealed hypertrophied cells in the epidermis with deeply basophilic enlarged nuclei and dark‐staining granular material in the cytoplasm. Transmission electron microscopy of these cells revealed naked hexagonal herpes‐like virus nucleocapsids (97 ± 7 nm) in their nuclei while the cytoplasm contained multiple aggregates of enveloped viral particles. This is the first report of herpes‐like virus particles in northern pike originating outside North America, where esocid herpesvirus‐1 (EsHV‐1) has previously been reported. Shared clinical, histological, morphological and epidemiological findings suggest that the observed particles in this report may also be EsHV‐1.
Phosphorylation State of the RNA Polymerase II C‐Terminal Domain (CTD) in Heat‐Shocked Cells
Authors: Venetianer Aniko , Dubois Marie‐Françoise , Nguyen Van Trung , Bellier Sylvain , Seo Sook‐Jae , Bensaude Olivier 
Published: September 2004

RNA polymerase (RNAP) II is a multisubunit enzyme composed of several different subunits. Phosphorylation of the C‐terminal domain (CTD) of the largest subunit is tightly regulated. In quiescent or in exponentially growing cells, both the unphosphorylated (IIa) and the multiphosphorylated (IIo) subunits of RNAP II are found in equivalent amounts as the result of the equilibrated antagonist action of protein kinases and phosphatases.In Drosophila and mammalian cells, heat shock markedly modifies the phosphorylation of the RNAP II CTD. Mild heat shocks result in dephosphorylation of the RNAP II CTD. This dephosphorylation is blocked in the presence of actinomycin D, as the CTD dephosphorylation observed in the presence of protein kinase inhibitors. Thus, heat shock might inactivate CTD kinases which are operative at normal growth temperatures, as some protein kinase inhibitors do. In contrast, severe heat shocks are found to increase the amount of phosphorylated subunit independently of the transcriptional activity of the cells.Mild and severe heat shocks activate protein kinases, which then phosphorylate, in vitro and in vivo, the CTD fused to β‐galactosidase. Most of the heat‐shock‐activated CTD kinases present in cytosolic lysates co‐purify with the activated mitogen‐activated protein (MAP) kinases, p42mapk and p44mapk. The weak CTD kinase activation occurring upon mild heat shock might be insufficient to compensate for the heat inactivation of the already existing CTD kinases. However, under severe stress, the MAP kinases are strongly heat activated and might prevail over the phosphatases. A survey of different cells and different heat‐shock conditions shows that the RNAP II CTD hyperphosphorylation rates follow the extent of MAP kinase activation.These observations lead to the proposal that the RNAP II CTD might be an in vivo target for the activated P42mapk and p44mapk MAP kinases.
Asters play only a dispensable role in the induction of the cleavage furrow in the blastomeres of early Xenopus embryos
Authors: Sakaida Tomoyuki , Inomata Shiho , Shinagawa Atsunori 
Published: September 2004

Kuroda et al. (2001) of our laboratory have previously revealed that exposure of early Xenopus embryos to 150 mm urethane results in complete suppression of formation of the asters and the cleavage furrow, as well as significant reduction of the size of the spindle in the blastomeres, allowing only 1 or 2 cycles of mitosis but not cytokinesis. In the course of closer examination of the effect of urethane on the cleavage of blastomeres of early Xenopus embryos, we unexpectedly discovered that exposure of early Xenopus embryos to 75 mm urethane did not prevent cell division at all, though asters were not detected in the blastomeres. Instead, they contained a spindle that appeared rather normal. They also formed the diastema, a thin yolk‐free structure, which is considered to play an essential role in the induction of the cleavage furrow. Essentially the same results were obtained in the exposure of embryos to vinblastine, a well‐known microtubule inhibitor: exposure of embryos to 20 µg/mL vinblastine resulted in complete suppression of cleavage of the blastomeres, where formation of both the spindle and asters were perfectly suppressed. By contrast, exposure of embryos to 5 µg/mL vinblastine did not prevent cleavage in the blastomeres though asters were not detected, whereas the rather normal spindle was formed. Thus, there was a close correlation between the formation of the normal spindle, not asters, and that of the cell division furrow and the diastema in the blastomeres of early Xenopus embryos. We suggest that while the spindle plays an essential role, asters are likely to play only a dispensable role in the induction of the cleavage furrow in even very large cells like the blastomeres of early Xenopus embryos.
Training in general paediatrics: Is it time for change?
Authors: Gunasekera H , Buckmaster A 
Published: September 2004

Objective:  To determine current Australian general paediatrician's perceptions regarding the adequacy of their training particularly in the new morbidity (NM) area (developmental, behavioural and psychosocial). To ascertain if there is a perceived need to change training in this area, the level of support for change and to canvass opinion on how to achieve change.Methods:  Australian general paediatricians were surveyed by mail in April 2002. The data obtained from those trained before and after the 1992 changes to training were compared by χ2 analysis.Results:  The response rate was 76%. More than one in five new referrals were for NM problems according to 62% of the respondents. The majority (67%) of respondents reported that they were poorly or very poorly trained for NM work in contrast to a majority (82%) who rated that they were well or very well trained for general paediatric work (P < 0.001). Respondents believed that they were poorly or very poorly trained in the use of stimulants (74%), selective serotonin reuptake inhibitors (SSRIs) (93%), tricyclic antidepressants (TCAs) (79%) and clonidine (86%), despite a third of scripts being for one of these medications. The majority of all general paediatricians (90%) want changes to advanced training. Seminars/tutorials, organized visits to general paediatricians’ rooms and a mandatory 12 month NM term were the most highly supported options for change.Conclusions:  In view of the prevalence of the NM problems, the perception of inadequate training and the overwhelming support for change it is time for new models of training to be developed and tested.