bluuebunny/crossref_metadata_2025 huggingface dataset:
Using the shape recovery method to evaluate indexing techniques
Authors: Oyarce Guillermo
Published: May 2008

Text representation, central to information processing, must be descriptive and discriminative. Although some of the many techniques to construct document representations may outperform others for certain tasks, no one is consistently better than others. Representations are still problematic. Evaluation techniques are needed to penetrate foundational questions about term behavior in representation. A study that applies the shape recovery analysis method is reported here as an evaluative tool to compare different indexing schemes. Three weight coefficients are used to rank indexing terms and are compared to the documents' full text. Two of the weight coefficients are novel and the third relies on the chi‐squared distribution. Multidimensional scaling reduces the dimensional space of the document surrogates into a two‐dimensional Cartesian space. Ten concentric circles evenly separated at 10% intervals of relevant data points starting at the centroid are used to construct a precision–recall curve. ANOVA is used for a straightforward computation of the 4 × 11 matrix of test data to see whether the four treatments yield the same P‐R result. A post hoc HSD Tukey multiple comparisons test among pairwise treatments is also used to discover homogeneous groups. The findings show the value of the methodology to study term weighting schemes, and their descriptiveness and discriminative power, as well as the potential strength of the novel coefficients introduced.
Variations of the low‐degree solar p‐mode frequencies for 10 years of GOLF observations
Authors: Grec G. , Renaud C.
Published: May 2008

We experiment with a method of measuring the frequency of solar p modes, intended to extend the passband for the variations of the frequency spectrum as high as possible. So far this passband is limited to a fraction of μ Hz for the classical analysis based on numerical fits of a theoretical line profile to a power spectrum averaged over periods lasting at least several weeks. This limit for the present analysis can be shifted to the mHz range, corresponding to some of the “5 min” oscillations, but in this range we use a lower resolution which allows us to separate odd and even p modes. We show an example of the results for long term variations and apply this analysis to search for a modulation of the p‐mode frequency spectrum by asymptotic series of solar g modes. A faint signal is found in the analysis of 10 years of GOLF data. This very preliminary result possibly indicates the detection of a small number of g modes of degree l = 1. A tentative determination of an observational value of the parameter P0 follows. P0 is the scaling factor of the asymptotic series of g modes and is a key data for solar core physics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Helioseismology program for the PICARD satellite
Authors: Corbard T. , Boumier P. , Appourchaux T. , Jiménez‐Reyes S.J. , Gelly B. , the PICARD team
Published: May 2008

The PICARD mission is a CNES micro‐satellite to be launched in 2009. Its goal is to better understand the Sun and the potential impact of its activity on earth climate by measuring simultaneously the solar total and spectral irradiance, diameter, shape and oscillations. We present the scientific objectives, instrumental requirements and data products of the helioseismology program of PICARD which aims to observe the low to mediumlp‐mode oscillations in intensity and search for g‐mode oscillation signatures at the limb. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Monitoring the scale factor of the PICARD SODISM instrument
Authors: Assus P. , Irbah A. , Bourget P. , Corbard T. , the PICARD team
Published: May 2008

The SODISM Telescope of the PICARD Space mission will perform diameter measurements by directly imaging the Sun on a CCD camera. An internal calibration system allows us to follow scale factor variations induced by instrument deformations resulting from temperature fluctuations on orbit or from others causes. We present this calibration system in this paper as well as some simulations on how to correct observations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection and temporal coherence of p‐modes below 1.4 mHz
Authors: Eff‐Darwich A. , Régulo C. , Korzennik S.G. , Hernández F. Pérez , Cortés T. Roca
Published: May 2008

Data collected recently by the helioseismic experiments aboard the SOHO spacecraft have allowed the detection of low degree p‐modes with increasingly lower order n. In particular, the GOLF experiment is currently able to unambiguously identify low degree modes with frequencies as low as 1.3 mHz. The detection of p‐modes with very low frequency (i.e., low n), is difficult due to the low signal‐to‐noise ratio in this spectral region and its contamination by solar signals that are not of acoustic origin. To address this problem without using any theoretical a priory, we propose a methodology that relies only on the inversion of observed values to define a spectral window for the expected locations of these low frequency modes. The application of this method to 2920‐day‐long GOLF observations is presented and its results discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fluorescent probes to evaluate the physiological state and activity of microbial biocatalysts: A guide for prokaryotic and eukaryotic investigation
Authors: Cao‐Hoang Lan , Marechal Pierre‐André , Lê‐Thanh Mai , Gervais Patrick , Waché Yves
Published: May 2008

Many fluorescent techniques are employed to evaluate the viability and activity of microbial cells used in biotechnology. These techniques are sometimes complex and the interpretation of results opened to misunderstanding. Moreover, new developments are constantly proposed especially concerning a more accurate evaluation of the state of the cells including eukaryotic microorganisms. This paper aims at presenting to biotechnologists unfamiliar with fluorescence the principles of these methods and the related possible pitfalls. It focuses on probes of the physical (integrity and fluidity) and energetical (intracellular pH and membrane potential) state of the cell membrane (bacterial and yeast cells) and presents also other probes (nucleic acids, respiration...) and new technical trends. The specificities of Gram‐negative bacterial cells are also discussed.
Transcriptional profiling of phenotypically different Epo‐Fc expressing CHO clones by cross‐species microarray analysis
Authors: Trummer Evelyn , Ernst Wolfgang , Hesse Friedemann , Schriebl Kornelia , Lattenmayer Christine , Kunert Renate , Vorauer‐Uhl Karola , Katinger Hermann , Müller Dethardt
Published: May 2008

Chinese hamster ovary (CHO) cells exhibit large variabilities regarding growth, recombinant protein production and post‐translational processing during cell line development and clone selection. To accelerate the development of stable high quality cell factories, new efficient strategies for cell screening and clone selection are required. In our work, we combined phenotypic characterisation of recombinant CHO clones during early cell line development with transcription profile analysis using cross‐species microarrays. The objective was to identify genes or gene patterns that correlate with clone specific alterations in terms of productivity, sialylation capacity and stress resistance. In all high producer clones transcriptional profiling revealed a common enrichment of gene ontology categories related to protein metabolism, transcription, nucleus and nucleolus, whereas no common genes were differentially regulated in clones showing higher sialylation capacities. Furthermore, we identified predictive stress‐related marker genes that were up‐regulated in one clone without showing the corresponding phenotype at an early stage of development. Thus, we successfully applied gene expression profiling to allocate transcriptomal differences to specific phenotypes that changed during cell line development. These promising results will further increase our efforts to develop CHO specific microarrays that deliver information about the suitability of a clone candidate for industrial production.
MP2 and DFT Calculations on Circulenes and an Attempt to Prepare the Second Lowest Benzolog, [4]Circulene
Authors: Christoph Hilmar , Grunenberg Jörg , Hopf Henning , Dix Ina , Jones Peter G. , Scholtissek Martin , Maier Günther
Published: May 2008

MP2 and DFT calculations have been carried out for [n]circulenes for n=3 to 20 in order to predict the strain energy and topology of these cyclically condensed aromatic systems. To synthesise [4]circulene (2), 1,5,7,8‐tetrakis(bromomethyl)biphenylene (14) was prepared from the corresponding tetramethyl derivative (8) and subjected to various dehalogenation reactions; all attempts to obtain [2.2]biphenylenophane (7) as a precursor for 2 by this route failed. Treatment of 14 with sodium sulfide furnished the thiaphanes 16 and 17, thermal and photochemical desulfurization of which also failed to provide 7. In a second approach [2.2]paracyclophane was converted to the pseudo‐geminal dithiol 23, which was subsequently bridged to the thiaphanes 22 and 24. On flash vacuum pyrolysis at 800 °C these were converted exclusively into phenanthrene (30). An approach to dehydrochlorinate the commercial product PARYLENE C® to the tetrahydro[4]circulene 7 led only to polymerisation. The X‐ray structures of the intermediates 8, 14, 17, 23, 24, 26, and 35 are reported.
Inverse relationship between adult hippocampal cell proliferation and synaptic rewiring in the dentate gyrus
Authors: Butz Markus , Teuchert‐Noodt Gertraud , Grafen Keren , van Ooyen Arjen
Published: May 2008

Adult neurogenesis is a key feature of the hippocampal dentate gyrus (DG). Neurogenesis is accompanied by synaptogenesis as new cells become integrated into the circuitry of the hippocampus. However, little is known to what extent the embedding of new neurons rewires the pre‐existing network. Here we investigate synaptic rewiring in the DG of gerbils (Meriones unguiculatus) under different rates of adult cell proliferation caused by different rearing conditions as well as juvenile methamphetamine treatment. Surprisingly, we found that an increased cell proliferation reduced the amount of synaptic rewiring. To help explain this unexpected finding, we developed a novel model of dentate network formation incorporating neurogenesis and activity‐dependent synapse formation and remodelling. In the model, we show that homeostasis of neuronal activity can account for the inverse relationship between cell proliferation and synaptic rewiring. © 2008 Wiley‐Liss, Inc.
Efficacy and tolerability of duloxetine in elderly patients with generalized anxiety disorder: a pooled analysis of four randomized, double‐blind, placebo‐controlled studies
Authors: Davidson Jonathan , Allgulander Christer , Pollack Mark H. , Hartford James , Erickson Janelle S. , Russell James M. , Perahia David , Wohlreich Madalaine M. , Carlson Janice , Raskin Joel
Published: May 2008

Objective

To assess the efficacy and tolerability of duloxetine in elderly patients with generalized anxiety disorder (GAD).

Methods

Acute‐phase data from a subset of patients (≥65 years) with GAD were pooled from four randomized, double‐blind, placebo‐controlled trials of duloxetine (3 flexible, 1 fixed dosing). Patients were treated with duloxetine 60–120 mg once daily or placebo for 9–10 weeks. The primary outcome measure was the mean baseline‐to‐endpoint change in Hamilton anxiety scale (HAMA) total score. Secondary measures included the HAMA psychic and somatic anxiety subscales and the Hospital Anxiety Depression Scale (HADS).

Results

Of 1491 patients randomly assigned to treatment, 4.9% (duloxetine, n = 45; placebo, n = 28) were ≥ 65 years old. Compared with placebo‐treated patients, duloxetine‐treated patients experienced significantly greater improvements on the HAMA‐total (p = 0.029), the HAMA‐psychic anxiety factor (p = 0.034), HADS‐anxiety (p = 0.049) and ‐depression scales (p = 0.026), but not the HAMA somatic anxiety factor (p = 0.074). Nausea was reported significantly more often in duloxetine‐treated patients (30.0% vs. 7.1%, p = 0.023); duloxetine‐treated patients experienced greater weight loss (p = 0.018). More duloxetine‐treated patients discontinued treatment due to an adverse event (22.2% vs. 0%; p = 0.006).

Conclusion

Duloxetine was effective in an elderly patient subset with GAD, although there was a high rate of discontinuations due to adverse events. Copyright © 2008 John Wiley & Sons, Ltd.
Microtubule assembly dynamics: An attractive target for anticancer drugs
Authors: Singh Parminder , Rathinasamy Krishnan , Mohan Renu , Panda Dulal
Published: May 2008

Microtubules, composed of αβ tubulin dimers, are dynamic polymers of eukaryotic cells. They play important roles in various cellular functions including mitosis. Microtubules exhibit differential dynamic behaviors during different phases of the cell cycle. Inhibition of the microtubule assembly dynamics causes cell cycle arrest leading to apoptosis; thus, qualifying them as important drug targets for treating several diseases including cancer, neuronal, fungal, and parasitic diseases. Although several microtubule‐targeted drugs are successfully being used in cancer chemotherapy, the development of resistance against these drugs and their inherent toxicities warrant the development of new agents with improved efficacy. Several antimicrotubule agents are currently being evaluated for their possible uses in cancer chemotherapy. Benomyl, griseofulvin, and sulfonamides have been used as antifungal and antibacterial drugs. Recent reports have shown that these drugs have potent antitumor potential. These agents are shown to inhibit proliferation of different types of tumor cells and induce apoptosis by targeting microtubule assembly dynamics. However, unlike vincas and taxanes, which inhibit cancer cell proliferation in nanomolar concentration range, these agents act in micromolar range and are considered to have limited toxicities. Here, we suggest that these drugs may have a significant use in cancer chemotherapy when used in combination with other anticancer drugs. © 2008 IUBMB IUBMB Life, 60(6): 368–375, 2008
Tumor lymphangiogenesis and melanoma metastasis
Authors: Rinderknecht Matthias , Detmar Michael
Published: May 2008

Malignant melanomas of the skin primarily metastasize to lymph nodes, and the detection of sentinel lymph node metastases serves as an important prognostic parameter. There is now compelling evidence that melanomas can induce lymphangiogenesis (growth of lymphatic vessels), mainly at the tumor–stroma interface, and that the level of tumor lymphangiogenesis is correlated with the incidence of sentinel lymph node metastases and with disease‐free survival. Thus, tumor lymphangiogenesis can serve as a novel prognostic predictor in melanoma. Vascular endothelial growth factor (VEGF)‐C, released by melanoma cells and by tumor‐associated macrophages, likely represents the major lymphangiogenic factor in melanoma, although other members of the VEGF family might also be involved. The recent discovery that tumors can induce a premetastatic niche, by inducing lymphatic vessel growth in sentinel lymph nodes even before metastasis, and that lymph node lymphangiogenesis enhances metastatic spread, indicates that activated lymphatic vessels represent novel targets for the detection and/or therapy of melanoma metastases. J. Cell. Physiol. 216: 347–354, 2008. © 2008 Wiley‐Liss, Inc.
iNOS expression requires NADPH oxidase‐dependent redox signaling in microvascular endothelial cells
Authors: Wu Feng , Tyml Karel , Wilson John X.
Published: May 2008

Redox regulation of inducible nitric oxide synthase (iNOS) expression was investigated in lipopolysaccharide and interferon‐γ (LPS + IFNγ)‐stimulated microvascular endothelial cells from mouse skeletal muscle. Unstimulated endothelial cells produced reactive oxygen species (ROS) sensitive to inhibition of NADPH oxidase (apocynin and DPI), mitochondrial respiration (rotenone) and NOS (L‐NAME). LPS + IFNγ caused a marked increase in ROS production; this increase was abolished by inhibition of NADPH oxidase (apocynin, DPI and p47phox deficiency). LPS + IFNγ induced substantial expression of iNOS protein. iNOS expression was prevented by the antioxidant ascorbate and by NADPH oxidase inhibition (apocynin, DPI and p47phox deficiency), but not by inhibition of mitochondrial respiration (rotenone) and xanthine oxidase (allopurinol). iNOS expression also was prevented by selective antagonists of ERK, JNK, Jak2, and NFκB activation. LPS + IFNγ stimulated activation/phosphorylation of ERK, JNK, and Jak2 and activation/degradation of IκB, but only the activation of JNK and Jak2 was sensitive to ascorbate, apocynin and p47phox deficiency. Ascorbate, apocynin and p47phox deficiency also inhibited the LPS + IFNγ‐induced DNA binding activity of transcription factors IRF1 and AP1 but not NFκB. In conclusion, LPS + IFNγ‐induced NFκB activation is necessary for iNOS induction but is not dependent on ROS signaling. LPS + IFNγ‐stimulated NADPH oxidase activity produces ROS that activate the JNK‐AP1 and Jak2‐IRF1 signaling pathways required for iNOS induction. Since blocking either NFκB activation or NADPH oxidase activity is sufficient to prevent iNOS expression, they are separate targets for therapeutic interventions that aim to modulate iNOS expression in sepsis. J. Cell. Physiol. 217: 207–214, 2008. © 2008 Wiley‐Liss, Inc.
Effect of Different Aluminum Alkyls on the Metallocene/Methylaluminoxane Catalyzed Polymerization of Higher α‐Olefins and Styrene
Authors: Vasilenko Irina V. , Kostjuk Sergei V. , Kaputsky Fyodor N. , Nedorezova Polina M. , Aladyshev Alexander M.
Published: May 2008

The replacement of MAO by different aluminum alkyls in the polymerization of higher α‐olefins catalyzed by rac‐EtInd2ZrCl2 and rac‐(CH3)2CInd2ZrCl2 and in the syndiospecific polymerization of styrene with CpTiCl3 as a catalyst was studied. An activating effect for all catalysts investigated was found when adding TIBA, while TEA and THA have a deactivating effect. It was found that more than half of the expensive methylaluminoxane can be successfully replaced by TIBA without deleterious effects on the catalyst activity and the properties of the polymers synthesized during higher α‐olefin polymerization catalyzed by rac‐EtInd2ZrCl2 and rac‐(CH3)2CInd2ZrCl2.

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Effect of Processing Parameters on the Mechanical Properties of Injection Molded Thermoplastic Polyolefin (TPO) Cellular Foams
Authors: Wong Steven , Lee John W. S. , Naguib Hani E. , Park Chul B.
Published: May 2008

In this study, the effects of processing parameters on the mechanical properties of injection molded thermoplastic polyolefin (TPO) foams are investigated. Closed cell TPO foams were prepared by injection molding process. The microstructure of these foamed samples was controlled by carefully altering the processing parameters on the injection molding machine. The foam morphologies were characterized in terms of skin thickness, surface roughness, and relative foam density. Tensile properties and impact resistance of various injection molded TPO samples were correlated with various foam morphologies. The findings show that the mechanical properties are significantly affected by foam morphologies. The experimental results obtained from this study can be used to predict the microstructure and mechanical properties of cellular injection molded TPO foams prepared with different processing parameters.

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Diethoxy‐azobis(pyridinium) Salt as Photoinitiator for Cationic Polymerization: Towards Wavelength Tunability by Cis–Trans Isomerization
Authors: Durmaz Yasemin Yuksel , Zaim Ömer , Yagci Yusuf
Published: May 2008

N,N′‐diethoxy‐4,4′‐azobis(pyridinium) hexafluorophosphate (DEAP) has been synthesized by alkylation of the corresponding N‐oxide and characterized. DEAP exhibits UV induced cis–trans isomerization with absorptions at around λ = 459 and 360 nm, respectively. The ability of the DEAP ion to act as a photoinitiator for the cationic polymerization of cyclohexene oxide and N‐vinylcarbazole is demonstrated. The initiation step involves the decay of the excited state of the trans form of the salt with homolytic bond rupture of the nitrogen–oxygen bond. Its potential use as a photoinitiator for free radical polymerization is also demonstrated using methyl methacrylate monomer as the example.

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Post‐Synthesis Functionalization of (Meth)acrylate Based Monoliths via Electron Beam Triggered Graft Polymerization
Authors: Beier Matthias J. , Knolle Wolfgang , Prager‐Duschke Andrea , Buchmeiser Michael R.
Published: May 2008

Porous polymeric monoliths were prepared via electron beam triggered free radical polymerization of (meth)acrylates. Post‐synthesis functionalization of these supports was accomplished via electron beam initiated free radical graft polymerization of methacryloyl‐substituted NHC precursors. The grafted precursors were converted into the corresponding copper complexes. Cu‐loadings were between 1.3 mg · g−1 and 1.5 mg · g−1. These supported catalysts were used in selected CO hydrosilylation and cyanosilylation reactions using a continuous flow setup.

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Synthesis, characterization, and self‐assembly of comb‐dendronized amphiphilic block copolymers
Authors: Yi Zhuo , Liu Xuanbo , Jiao Qing , Chen Erqiang , Chen Yongming , Xi Fu
Published: May 2008

Novel amphiphilic comb‐dendronized diblock copolymers composed of hydrophobic Percec‐type dendronized polystyrene block and hydrophilic comb‐like poly(ethylene oxide) grafted polymethacrylate P(PEOMA) block were designed and synthesized via two steps of atom transfer radical polymerization (ATRP). The comb‐like P(PEOMA) prepared by ATRP of macromonomers (PEOMA) with two different molecular weights (Mn = 300 and 475) were used to initiate the sequent ATRP of dendritic styrene macromonomer (DS). The molecular weights and compositions of the obtained block copolymers were determined by 1H NMR analysis. The copolymers with relatively narrow polydispersities (1.27–1.38) were thus obtained. The bulk properties of comb‐dendronized block copolymers were studied by using differential scanning calorimetry, polarized optical microscopy and wide‐angle X‐ray diffraction (WAXD). Similar to dendronized homopolymers, the block copolymers exhibited hexagonal columnar liquid‐crystalline phase structure. By using such amphiphilic comb‐dendronized block copolymers as building blocks, the rich self‐assembly morphologies, such as twisted string, vesicle, and large compound micelle (LCM), were obtained in a mixture of CH3OH and THF. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4205–4217, 2008
Optically absorbing trilayer films fabricated using a Filtered Cathodic Vacuum Arc
Authors: Abaffy N. Biluš , Partridge J. G. , Plessis J. du , McCulloch D. G.
Published: May 2008

A Filtered Cathodic Vacuum Arc (FCVA) deposition system has been used to produce Al2O3/Al/Al2O3 trilayers for use as optically absorbing coatings. Ellipsometry was used to measure the optical constants of the AlOx films and X‐ray photoelectron spectroscopy (XPS) was used to measure their stoichiometry. It was found that a wide range of Ar/O2 inlet flow‐rates could be used to produce stoichiometric Al2O3 in the FCVA system. Several Al2O3/Al/Al2O3 tri‐layers have been produced with different Al layer thicknesses and the simulated and experimental reflection characteristics have been compared. An average reflectance of 4% was achieved over the visible spectrum for the optimised trilayer coating deposited on silicon. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis, stability and electrocatalytic activity of polymer‐stabilized monometallic Pt and bimetallic Pt/Cu core–shell nanoparticles
Authors: Muraviev D. N. , Macanás J. , Ruiz P. , Muñoz M.
Published: May 2008

In this paper we report the results obtained for inter‐matrix synthesis (IMS) and characterization of monometallic and bimetallic polymer‐stabilized metal nanoparticles (PSMNPs). The IMS procedure is based on the use of appropriately functionalized polymeric membranes as nanoreactors, which allows both synthesis and characterization of the composition and morphology of PSMNPs inside the membranes. The membranes were prepared by using noncrosslinked sulfonated poly(etherether ketone) (SPEEK) of desired degree of sulfonation, which provided insolubility of the polymer in water and solubility in some organic solvents (e.g. dimethylformamide). The IMS of PSMNPs involved loading of the membrane with metal ions or complexes followed by metal reduction inside the membrane resulting in the formation of either monometallic (Cu or Pt) or bimetallic (Pt/Cu) PSMNPs with core–shell structure. The electrocatalytic activity of the PSMNPs was estimated by measuring the electrochemical response of amperometric sensors prepared by using SPEEK‐Pt‐PSMNP and SPEEK‐Pt/Cu‐PSMNP nanocomposite membranes as sensing elements to detect H2O2. At the same values of Pt loading the response of Pt/Cu‐PSMNP‐based sensors appeared to be far higher than that of sensors modified with Pt‐PSMNP membranes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polymerization‐direction‐controlled growth of polydiacetylene on artificial silicon oxide templates
Authors: Akai‐Kasaya Megumi , Higuchi Yuichi , Yura Kayo , Yoshida Akihito , Saito Akira , Aono Masakazu , Kuwahara Yuji
Published: May 2008

The control of anisotropic polydiacetylene film formation has been demonstrated on a silicon oxide surface with artificial periodic grooves. A diacetylene monomer film was grown by molecular deposition on the grooves, and polymerization was induced by ultraviolet light irradiation. Anisotropic polymer chain formation was successfully investigated on grooves with a depth larger than 40 nm and a pitch narrower than 2 µm. The interplay between molecular kinetic growth parameters and preferential interaction with a patterned surface has been discussed considering the calculated dimerization energy of monomers. Copyright © 2008 John Wiley & Sons, Ltd.
Mounting a hydrogenase analog on calixarenes—designing a nature‐inspired solid state catalyst for fuel cells by density functional theory
Authors: Sy Dy Eben , Kasai Hideaki , Redshaw Carl , Pickett Christopher J.
Published: May 2008

The hydrogen‐fuel PEFC (polymer electrolyte fuel cell) is among the most promising alternative power generators of the future. But for it to become widely used, an alternative catalyst to platinum must be developed. While there have been previous attempts to synthesize hydrogenase mimics for this purpose, the current state of artificial hydrogenases can be summarized into two groups: sufficiently active but not in a stable solid state; and in the solid state but not sufficiently active.

We model a modified active site of Fe‐only hydrogenases deposited on a variety of calixarenes for solid‐state support by density functional calculations. Among the calixarenes considered, our calculations have shown that calix[5]arene is so far the most viable macrocycle to hold the di‐iron site. Our calculations also show that the crucial hydrogenase active site characteristics are maintained in this material: having an FeFe bond and anti‐bond at the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) respectively; and the bonding orbitals on the Fe centers connected to the sulfur of the electron chain at the HOMO. Copyright © 2008 John Wiley & Sons, Ltd.
Mechanism of adhesion promotion between aluminium sheet and polypropylene with maleic anhydride‐grafted polypropylene by γ‐aminopropyltriethoxy silane
Authors: Chen Ming‐An , Zhang Xin‐Ming , Huang Rong , Lu Xue‐Bin
Published: May 2008

The effect of concentration of γ‐aminopropyltriethoxy (γ‐APS) solution on shear strength of adhesive bonding between aluminium sheet and polypropylene (PP) with addition of a certain amount of maleic anhydride‐grafted polypropylene (PP‐g‐MAH) has been investigated. It is shown that the lap shear strength is promoted obviously with pre‐treatment of aluminium sheet by γ‐APS. The maximum strength is obtained at a concentration of 3% γ‐APS solution. With further high concentration of γ‐APS, the lap shear strength decreases. The examination of the separated surfaces by X‐ray photoelectron spectroscopy (XPS) shows that (CO)2OAl and C(O)OAl are formed for adhesive bonding between PP with the addition of 20 wt% PP‐g‐MAH and aluminium sheet without pre‐treatment by γ‐APS, and that the area ratio of C related to oxygen on the separated aluminium side is 33.28%, which is obviously higher than 14% on the polymer side. As for adhesive bonding between PP with the addition of 20% PP‐g‐MAH and 3% γ‐APS pre‐treated aluminium sheet, C(O)NC(O) and C(O)NH are formed. The area ratio of C related to oxygen on the separated polymer side increases to 24.99%. It is proposed that γ‐APS pre‐treatment improves the distribution and shape of PP‐g‐MAH chains in the region adsorbed on the substrate and the region adjacent to this region. The chemical interactions at the interface are also proposed. Copyright © 2008 John Wiley & Sons, Ltd.
Soil removal as a rate process
Authors: Loeb L. , Sanford P. B. , Cochran S. D.
Published: May 2008

The rate of soil removal during multiple cycle washing has been studied for three artificially soiled cotton test cloths. Results are considered in relation to a soil removal rate concept proposed some years ago by Vaughn, Vittone, and Smith. It is shown that the rate of removal for these soils, when washed in the Terg‐O‐Tometer with a built, anionic, synthetic detergent, does not correspond to a simple first order rate process as proposed by Vaughn et al. Rather, it was found that under a variety of washing situations the percentage soil removal increased linearly with the log of cumulative wash time. Further, it was shown that for those experiments involving detergent concentration or level of mechanical action, the slopes of these log time relationships, which reflect the rate of soil removal, vary in the expected manner.
Quantitative applications of high‐resolution proton magnetic resonance measurements in the characterization of detergent chemicals
Authors: Crutchfield M. M. , Irani R. R. , Yoder J. T.
Published: May 2008

Quantitative hydrogen nuclear magnetic resonance measurements are used for the determination of average structures of detergent chemicals. For alkylbenzenes, alkylphenols, and ethylene oxide (EO) adducts of alkylphenols, the following quantities can be measured: average lengths of alkyl chains, average molecular weights, degree and kind of branching in the alkyl chain, ortho‐para distribution of aryl substituents, and average lengths of BO chains. Accuracy is of the the order of ŷ 2% of the total hydrogen. The method is nondestructive, and sample volumes as small as 0.007 ml have been used.
Monoacylglycerols Activate Capsaicin Receptor, TRPV1
Authors: Iwasaki Yusaku , Saito Orine , Tanabe Manabu , Inayoshi Kimiko , Kobata Kenji , Uno Shuichi , Morita Akihito , Watanabe Tatsuo
Published: May 2008

Transient receptor potential vanilloid subtype 1 (TRPV1) is known as capsaicin (CAP) receptor and activated by CAP. Activation of TRPV1 by CAP increases energy expenditure and thermogenesis in rodents or human. Therefore, TRPV1 may be target for energy expenditure enhancement and thermogenesis. To search for novel TRPV1 agonist, we screened 19 types of foods by using TRPV1‐expressing HEK293 cells. TRPV1 was activated by hexane extract of wheat flour, and its functional compounds were 1‐monoacylglycerols containing oleic, linoleic, and α‐linolenic acids. Their potencies (EC50) were about 50 times larger than that of CAP and their efficacies (maximal response) were about half of that of CAP. TRPV1 was activated by 1‐monoacylglycerols (MGs) having C18 and C20 unsaturated and C8–C12 saturated fatty acid (FA). Moreover, 2‐MGs having C18 and C20 unsaturated FA acted on TRPV1 with the same potency. On the other hand, no activation of TRPV1 was induced by MGs having C16 and C18 saturated FA, di‐ or triacylglycerols of C18:1 FA. Pain‐relating aversive responses were induced when TRPV1‐activating 1‐monoacylglycerols (50 mM) was administered subcutaneously into rat hind paw. These effects were inhibited by the co‐injection of capsazepine (10 mM) which is a TRPV1 competitive antagonist. These results suggested that these 1‐monoacylglycerols activate TRPV1 in vitro and in vivo.
Response biases in preschool children's ratings of pain in hypothetical situations
Authors: von Baeyer Carl L. , Forsyth Sasha J. , Stanford Elizabeth A. , Watson Mark , Chambers Christine T.
Published: May 2008

Response biases are systematic biases in responding to test items that are unrelated to the content of the items. Examples often reported in young children include choosing only the lowest or highest anchors of a scale, or choosing a left‐to‐right sequence of responses. We investigated the presence of response biases in young children's ratings of pain in hypothetical situations, as a way of gauging their developing understanding of a pain scale over the preschool years. Children aged 3–5 years (N=185) rated items from the Charleston Pediatric Pain Pictures (CPPP) using the Faces Pain Scale‐Revised (FPS‐R). Response biases were identified objectively by computer pattern identification. Anchor biases (choosing the lowest and highest pain faces) occurred in 16% of children. Left–right or right–left sequences occurred in 35%. Monte Carlo simulation established that such patterns occur infrequently by chance (<3% for anchor biases; <6% for sequence biases). Response biases were identified more often in younger than older children. These results reveal that response biases are common in children under 5 years. Clinicians should consider self‐report pain ratings from preschoolers with caution, seek complementary observational assessment, and investigate discrepancies between self‐report and observational estimates of pain. Simplified forms, instructions, and methods of administration for self‐report scales should be developed and validated for use with 3‐ and 4‐year‐olds.
Overexpression of SnoN/SkiL, amplified at the 3q26.2 locus, in ovarian cancers: A role in ovarian pathogenesis
Authors: Nanjundan Meera , Cheng Kwai Wa , Zhang Fan , Lahad John , Kuo Wen-Lin , Schmandt Rosemarie , Smith-McCune Karen , Fishman David , Gray Joe W. , Mills Gordon B.
Published: May 2008

High‐resolution array comparative genomic hybridization of 235 serous epithelial ovarian cancers demonstrated a regional increase at 3q26.2 encompassing SnoN/SkiL, a coregulator of SMAD/TGFβ signaling. SnoN RNA transcripts were elevated in ∼80% of advanced stage serous epithelial ovarian cancers. In both immortalized normal (TIOSE) and ovarian carcinoma cell lines (OVCA), SnoN RNA levels were increased by TGFβ stimulation and altered by LY294002 and JNK II inhibitor treatment suggesting that the PI3K and JNK signaling pathways may regulate TGFβ‐induced increases in SnoN RNA. In TIOSE, SnoN protein levels were reduced 15min post TGFβ‐stimulation, likely by proteosome‐mediated degradation. In contrast, in OVCA, SnoN levels were elevated 3h post‐stimulation potentially as a result of inhibition of the proteosome. To elucidate the role of SnoN in ovarian tumorigenesis, we explored the effects of both increasing and decreasing SnoN levels. In both TIOSE and OVCA, SnoN siRNA decreased cell growth between 20 and 50% concurrent with increased p21 levels. In TIOSE, transient expression of SnoN repressed TGFβ induction of PAI‐1 promoters with little effect on the p21 promoter or resultant cell growth. In contrast to the effects of transient expression, stable expression of SnoN in TIOSE led to growth arrest through induction of senescence. Collectively, these results implicate SnoN levels in multiple roles during ovarian carcinogenesis: promoting cellular proliferation in ovarian cancer cells and as a positive mediator of cell cycle arrest and senescence in non‐transformed ovarian epithelial cells.
The Rocourt Tephra, a Widespread 90–74 ka stratigraphic marker in Belgium
Authors: Pouclet André , Juvigné Etienne , Pirson Stéphane
Published: May 2008

A new study of the stratigraphy and composition of the Rocourt Tephra is performed at five sites in Belgium and brackets the age of the tephra between 90.3 and 74 ka. The volcanic glass grains have a typical shape of phreatomagmatic eruption products. A large set of tephra minerals were analyzed, namely clinopyroxene, orthopyroxene, amphibole, and Cr-spinel. The compositions of these minerals have been compared with the lava xenocrysts, megacrysts, and phenocrysts of the proximate Eifel volcanic province for which the origin has been determined (mantle xenoliths, high-pressure cumulates, and middle- to low-pressure magmatic phases). This allowed us to determine the likely origin of the tephra minerals. The Rocourt Tephra source could be a West Eifel volcano that was fed by a deep-seated magma batch rich in high- to middle-pressure minerals.
Further counterexamples to a conjecture of Beilinson
Authors: de Jeu Rob
Published: May 2008

We give stronger counterexamples to a conjecture of Beilinson.
On K2 of varieties over number fields
Authors: González-Avilés Cristian D.
Published: May 2008

Let k be a number field and let X be a smooth, projective and geometrically integral k-variety. We show that, if the geometric Néron-Severi group of X is torsion-free, then the Galois cohomology group is finite. Previously this group was only known to have a finite exponent. We also obtain a vanishing theorem for this group, showing in particular that it is trivial if X belongs to a certain class of abelian varieties with complex multiplication. The interest in the above cohomology group stems from its connection to the torsion subgroup of the Chow group CH2(X) of codimension 2 cycles on X. In the last section of the paper we record certain results on curves which must be familiar to all specialists in this area but which we have not formerly seen in print.
Cohomologically triangulated categories I
Authors: Baues H.-J. , Muro F.
Published: May 2008

We introduce cohomologically triangulated categories as triples (A,t,▽) given by an additive categoryA, an additive equivalencet:AAand a cohomology class ▽ in the translation cohomologyH3(A,t). A stable homotopy theoryCwithA= HoCyields such a triple and the class of distinguished triangles inAis deduced from ▽.
HIGHER EPISTASIS IN GENETIC ALGORITHMS
Authors: IGLESIAS M. T. , PEÑARANDA V. S. , VIDAL C. , VERSCHOREN A.
Published: May 2008

We study thek-epistasis of a fitness function over a search space. This concept is a natural generalization of that of epistasis, previously considered by Davidor, Suys and Verschoren and Van Hove and Verschoren [Y. Davidor, in:Foundations of genetic algorithms, Vol. 1, (1991), pp. 23–25; D. Suys and A. Verschoren, ‘Proc Int. Conf. on Intelligent Technologies in Human-Related Sciences (ITHURS’96), Vol. II (1996), pp. 251–258; H. Van Hove and A. Verschoren,Comput. Artificial Intell.14(1994), 271–277], for example. We completely characterize fitness functions whosek-epistasis is minimal: these are exactly the functions of orderk. We also obtain an upper bound for thek-epistasis of nonnegative fitness functions.
NEIGHBOURHOODS OF INDEPENDENT SETS FOR (a,b,k)-CRITICAL GRAPHS
Authors: ZHOU SIZHONG , XU YANG
Published: May 2008

Let G be a graph of order n. Let a, b and k be nonnegative integers such that 1≤a≤b. A graph G is called an (a,b,k)-critical graph if after deleting any k vertices of G the remaining graph of G has an [a,b]-factor. We provide a sufficient condition for a graph to be (a,b,k)-critical that extends a well-known sufficient condition for the existence of a k-factor.
ON R-SECTORIAL DERIVATIVES ON BERGMAN SPACES
Authors: BÁRTA TOMÁŠ
Published: May 2008

In this paper we show boundedness of vector-valued Bergman projections on simple connected domains. With this result we show R-sectoriality of the derivative on the Bergman space onC+and maximalLp-regularity for an integrodifferential equation with a kernel in the Bergman space.
New dynamic subgrid-scale heat flux models for large-eddy simulation of thermal convection based on the general gradient diffusion hypothesis
Authors: WANG BING-CHEN , YEE EUGENE , BERGSTROM DONALD J. , IIDA OAKI
Published: May 2008

Three new dynamic tensor thermal diffusivity subgrid-scale (SGS) heat flux (HF) models are proposed for large-eddy simulation of thermal convection. The constitutive relations for the proposed modelling approaches represent the most general explicit algebraic formulations possible for the family of SGS HF models constructed using the resolved temperature gradient and SGS stress tensor. As a result, these three new models include a number of previously proposed dynamic SGS HF models as special cases. In contrast to the classical dynamic eddy thermal diffusivity SGS HF model, which strictly requires the SGS heat flux be aligned with the negative of the resolved temperature gradient, the three new models proposed here admit more degrees of freedom, and consequently provide a more realistic geometrical and physical representation of the SGS HF vector. To validate the proposed models, numerical simulations have been performed based on two benchmark test cases of neutrally and unstably stratified horizontal channel flows.
On the derivation of the Navier–Stokes–alpha equations from Hamilton's principle
Authors: SOWARD A. M. , ROBERTS P. H.
Published: May 2008

We investigate the derivation of Euler's equation from Hamilton's variational principle for flows decomposed into their mean and fluctuating parts. Our particular concern is with the flow decomposition used in the derivation of the Navier–Stokes–α equation which expresses the fluctuating velocity in terms of the mean flow and a small fluctuating displacement. In the past the derivation has retained terms up to second order in the Lagrangian which is then averaged. The variation is effected by incrementing the mean velocity, while holding the moments of the products of the displacements fixed. The process leads to a mean Euler equation for the mean velocity. The Navier–Stokes–α equation is only obtained after making a further closure approximation, which is not the concern of this paper. Instead attention is restricted here to the exact analysis of Euler's equation. We show that a proper implementation of Hamilton's principle, which concerns the virtual variation of particle paths, can only be achieved when the fluctuating displacement and mean velocity are varied in concert. This leads to an exact form of Euler's equation. If, on the other hand, the displacement is held fixed under the variation, a term in Euler's equation is lost. Averaging that erroneous form provides the basis of the Navier–Stokes–α equation. We explore the implications of the correct mean equation, particularly with regard to Kelvin's circulation theorem, comparing it with the so called GLM and glm-equations.
Numerical analysis of two-dimensional motion of a freely falling circular cylinder in an infinite fluid
Authors: NAMKOONG KAK , YOO JUNG YUL , CHOI HYOUNG G.
Published: May 2008

The two-dimensional motion of a circular cylinder freely falling or rising in an infinite fluid is investigated numerically for the range of Reynolds number Re, < 188 (Galileo number G < 163), where the wake behind the cylinder remains two-dimensional, using a combined formulation of the governing equations for the fluid and the dynamic equations for the cylinder. The effect of vortex shedding on the motion of the freely falling or rising cylinder is clearly shown. As the streamwise velocity of the cylinder increases due to gravity, the periodic vortex shedding induces a periodic motion of the cylinder, which is manifested by the generation of the angular velocity vector of the cylinder parallel to the cross-product of the gravitational acceleration vector and the transverse velocity vector of the cylinder. Correlations of the Strouhal–Reynolds-number and Strouhal–Galileo-number relationship are deduced from the results. The Strouhal number is found to be smaller than that for the corresponding fixed circular cylinder when the two Reynolds numbers based on the streamwise terminal velocity of the freely falling or rising circular cylinder and the free-stream velocity of the fixed one are the same. From numerical experiments, it is shown that the transverse motion of the cylinder plays a crucial role in reducing the Strouhal number. The effect of the transverse motion is similar to that of suction flow on the low-pressure side, where a vortex is generated and then separates, so that the pressure on this side recovers with the vortex separation retarded. The effects of the transverse motion on the lift, drag and moment coefficients are also discussed. Finally, the effect of the solid/fluid density ratio on Strouhal–Reynolds-number relationship is investigated and a plausible correlation is proposed.
High concentrations of a passive scalar in turbulent dispersion
Authors: MOLE NILS , SCHOPFLOCHER THOMAS P. , SULLIVAN PAUL J.
Published: May 2008

In problems involving the dispersion of hazardous gases in the atmosphere, the distribution of high concentrations is often of particular interest. We address the modelling of the distribution of high concentrations of a dispersing passive scalar at large Péclet number, concentrating on the case of steady releases. We argue, from the physical character of the small-scale processes, and from the statistical theory of extreme values, that the high concentrations can be fitted well by a Generalized Pareto Distribution (GPD). This is supported by evidence from a range of experiments. We show, furthermore, that if this is the case then the ratios of successive high-order absolute moments of the scalar concentration are linearly related to the reciprocal of the order. The linear fit thus obtained allows the GPD parameters to be determined from the moments. In this way the moments can be used to deduce the properties of the high concentrations, in particular the maximum possible concentration θmax = θmax(x). We argue, on general physical grounds, that θmax/C0 (where C0 = C0(X) is the centreline mean concentration, and X is the downstream distance from the source) decreases to zero very far from the centreline, but that the decrease takes place on a length scale much larger than the mean plume width (because it is controlled by the relatively slowly acting molecular diffusion, rather than the fast turbulent advection). Thus, over the distances for which accurate measurements can be made, we expect θmax/C0 to be approximately constant throughout the plume cross-section. On the centreline, we argue that θmax/C0 increases downstream from the source, reaches a maximum and then decreases, ultimately tending to 1 far downstream. In support of these deductions we present results for some high-quality data for a steady line source in wind tunnel grid turbulence. Finally, we apply to this problem some existing models for the relationships between moments. By considering the behaviour far from the centreline in these models, and linking the moments to the high concentrations, we derive relationships between the model parameters. This allows us to derive an expression for θmax/C0 which depends on a total of 5 parameters, and (weakly) on C/C0 (where C = C(x) is the local mean concentration). Comparison with the data is encouraging. We also discuss possible methods for modelling the spatial variation of these 5 parameters.