bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue inhibitor of metalloproteinase 1 regulates matrix metalloproteinase activity during newt limb regeneration
Authors: Stevenson Tamara J. , Vinarsky Vladimir , Atkinson Donald L. , Keating Mark T. , Odelberg Shannon J.
Published: December 2005

Matrix metalloproteinase (MMP) activity is important for newt limb regeneration. In most biological processes that require MMP function, MMP activity is tightly controlled by a variety of mechanisms, including the coexpression of natural inhibitors. Here, we show that gene expression of one such inhibitor, tissue inhibitor of metalloproteinase 1 (NvTIMP1), is upregulated during the wound healing and dedifferentiation stages of regeneration when several MMPs are at their maximal expression levels. Newt MMPs and NvTIMP1 also exhibit similar spatial expression patterns during the early stages of limb regeneration. NvTIMP1 inhibits the proteolytic activity of regeneration‐related newt MMPs and, like human TIMP1, can induce a weak mitogenic response in certain cell types. These results suggest that NvTIMP1 may be functioning primarily to maintain optimal levels of MMP activity during the early stages of limb regeneration, while possibly serving a secondary role as a mitogen. Developmental Dynamics 235:606–616, 2006. © 2005 Wiley‐Liss, Inc.
Dpp signaling down‐regulates the expression of VM32E eggshell gene during Drosophila oogenesis
Authors: Bernardi Fabio , Cavaliere Valeria , Andrenacci Davide , Gargiulo Giuseppe
Published: December 2005

Among the members of the Drosophila melanogaster vitelline membrane protein gene family, VM32E has the unique feature of being a component of both the vitelline and the endochorion layers. The VM32E gene is expressed at stage 10 of egg chamber development in the main body follicle cells, and it is repressed in the anterior and posterior follicle cells. Here, we show that this spatial restriction of VM32E gene expression is conserved in the D. pseudoobscura orthologous gene, suggestive of a conserved function of VM32E protein. The VM32E gene is not expressed in the centripetal migrating follicle cells, where the Decapentaplegic (Dpp) pathway is active in patterning the anterior eggshell structures. By analyzing the native VM32E gene and the activity of specific VM32E regulatory regions, in genetic backgrounds altering the Dpp pathway, we show that VM32E gene is negatively regulated by the Dpp signaling. Therefore, it appears that the Dpp signaling pathway executes its control on eggshell morphogenesis also by controlling the expression of eggshell structural genes. Developmental Dynamics 235:768–775, 2006. © 2005 Wiley‐Liss, Inc.
Novel Carbonyliridium and ‐rhodium Complexes Containing 2,6‐Bis[(4′S)‐4′‐isopropyloxazolin‐2′‐yl]pyridine (iPr‐pybox) and 2,6‐Bis[(4′R)‐4′‐phenyloxazolin‐2′‐yl]pyridine (Ph‐pybox) Ligands
Authors: Cuervo Darío , Díez Josefina , Gamasa M. Pilar , Gimeno José , Paredes Paloma
Published: December 2005

The iridium(I) complexes [Ir(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [R‐pybox = (S,S)‐iPr‐pybox (1), (R,R)‐Ph‐pybox (2)] have been prepared by reaction of their precursor complexes [Ir(η2‐C2H4)2(κ3‐N,N,N‐R‐pybox)][PF6] (R = iPr or Ph) with carbon monoxide. The analogous carbonylrhodium(I) complexes [Rh(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [R‐pybox = (S,S)‐iPr‐pybox (3), (R,R)‐Ph‐pybox (4)] have been synthesised by reaction of [Rh(μ‐Cl)(η2‐C2H4)2]2, carbon monoxide, R‐pybox and NaPF6. Complexes 1–4 undergo oxidative addition reactions with iodine and CH3I leading, with high stereoselectivity, to the complexes [MI(X)(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [M = Ir, R = iPr, X = I (5); M = Rh, R = iPr, X = I (6); M = Rh, R = Ph, X = I (7); M = Ir, R = iPr, X = CH3 (8); M = Ir, R = Ph, X = CH3 (9); M = Rh, R = iPr, X = CH3 (10); M = Rh, R = Ph, X = CH3 (11)]. The treatment of complexes 1 and 2 with HCl, allyl chloride or acyl chloride results, in most cases, in the stereoselective formation of the iridium(III) complexes [IrHCl(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [R = iPr (12), Ph (13)], [IrCl(η1‐CH2CH=CH2)(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [R = iPr (14), Ph (15)] or [IrCl{η1‐C(O)CH3}(CO)(κ3‐N,N,N‐R‐pybox)][PF6] [R = iPr (16), Ph (17)], respectively. The structures of derivatives 10 and 15 have been determined by single‐crystal X‐ray diffraction analysis. The catalytic activity of monocarbonylrhodium(I) and ‐iridium(I) complexes 1 and 3 in the hydrosilylation and dehydrosilylation of acetophenone with diphenylsilane has also been examined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Pyrophosphate and ATP as Stabilizing Ligands for High‐Valent Nickel Complexes
Authors: Shamir Dror , Zilbermann Israel , Maimon Eric , Shames Alexander I. , Cohen Haim , Meyerstein Dan
Published: December 2005

ATP stabilizes trivalent nickel complexes which suggests that another plausible role of ATP in biological systems is the stabilization of high‐valent transition metal complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Gram‐Scale Preparation of a p‐(C‐Glucopyranosyl)‐L‐phenylalanine Derivative by a Negishi Cross‐Coupling Reaction
Authors: Ousmer Malika , Boucard Valérie , Lubin‐Germain Nadège , Uziel Jacques , Augé Jacques
Published: December 2005

A p‐(C‐glucopyranosyl)‐L‐phenylalanine derivative protected to be directly incorporated into a peptidic chain is prepared in 37 % yield from glucose on a gram scale, with a Negishi cross‐coupling reaction as the key step. Zincated glucal and p‐iodo‐L‐phenylalanine are involved in this organometallic coupling, which gives rise to a link between the sugar and amino acid moieties in 90 % yield; the β‐gluco configuration of the C‐glycopyranosyl amino acid is ascertained by a stereoselective hydroboration of the double bond of the glucal. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Liquid Crystals Based on Hypervalent Sulfur Fluorides: The trans‐(Trifluoromethyl)tetrafluorosulfuranyl Group
Authors: Kirsch Peer , Hahn Alexander
Published: December 2005

Selective direct fluorination provides a convenient access to new classes of liquid crystals and dyes carrying a trans‐(trifluoromethyl)tetrafluorosulfuranyl group, a building block in organic chemistry with highly unusual and interesting properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Preparation and Chiroptical Studies of Dendritic Alkaloid Derivatives
Authors: Hahn Uwe , Kaufmann Astrid , Nieger Martin , Julínek Ondřej , Urbanova Marie , Vögtle Fritz
Published: December 2005

A series of dendritic substituted alkaloids, deriving from quinine or atropine and Fréchet‐type dendrons up to generation three, have been prepared. Enantioseparation of the dendronized atropine ammonium salts was achieved by HPLC on chiral stationary phases. Investigation of the chiroptical properties of the series of dendrimers by circular dichroism spectroscopy revealed an influence of the chiral core on the dendritic part with regard to the intensities of the Cotton bands. The chirality was found to be dependent on its chiral elements and the generation of the formally achiral dendritic branch attached to the chiral core (“dendritic effect”). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Hierarchic multigrid iteration strategy for the discontinuous Galerkin solution of the steady Euler equations
Authors: Hillewaert Koen , Chevaugeon Nicolas , Geuzaine Philippe , Remacle Jean‐François
Published: December 2005

We study the efficient use of the discontinuous Galerkin finite element method for the computation of steady solutions of the Euler equations. In particular, we look into a few methods to enhance computational efficiency. In this context we discuss the applicability of two algorithmical simplifications that decrease the computation time associated to quadrature. A simplified version of the quadrature free implementation applicable to general equations of state, and a simplified curved boundary treatment are investigated. We as well investigate two efficient iteration techniques, namely the classical Newton–Krylov method used in computational fluid dynamics codes, and a variant of the multigrid method which uses interpolation orders rather than coarser tesselations to define the auxiliary coarser levels. Copyright © 2005 John Wiley & Sons, Ltd.
Detailed methylation analysis of CpG islands on human chromosome region 9p21
Authors: Weeks Robert J. , Morison Ian M.
Published: December 2005

Deletion of 9p21 is the most commonly reported chromosomal abnormality in pediatric acute lymphoblastic leukemia, and published data suggest that the maternal chromosome is preferentially deleted. Preferential maternal deletion of 9p21 and reports of a differentially methylated region (DMR) and of parental effects in mice with lymphoma suggest there may be an unrecognized imprinted locus in this region. To screen for DMRs, we used the mcrBC/HpaII screening method and peripheral‐blood DNA. Of 36 CpG islands within an 8.5‐Mb region of 9p21, seven were identified as putative DMRs and were further analyzed by bisulfite sequencing. Neither any of the CpG islands nor a previously published putative DMR nearby showed evidence of differential parental methylation; however, the published DMR did demonstrate sequence‐dependent differential methylation. Our data, which showed heterogeneous and low‐level methylation of CpG islands, have obvious implications for methylation studies. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. © 2005 Wiley‐Liss, Inc.
Functional expression of Kir4.1 channels in spinal cord astrocytes
Authors: Olsen M.L. , Higashimori H. , Campbell S.L. , Hablitz J.J. , Sontheimer H.
Published: December 2005

Spinal cord astrocytes (SCA) have a high permeability to K+ and hence have hyperpolarized resting membrane potentials. The underlying K+ channels are believed to participate in the uptake of neuronally released K+. These K+ channels have been studied extensively with regard to their biophysics and pharmacology, but their molecular identity in spinal cord is currently unknown. Using a combination of approaches, we demonstrate that channels composed of the Kir4.1 subunit are responsible for mediating the resting K+ conductance in SCA. Biophysical analysis demonstrates astrocytic Kir currents as weakly rectifying, potentiated by increasing [K+]o, and inhibited by micromolar concentrations of Ba2+. These currents were insensitive to tolbutemide, a selective blocker of Kir6.x channels, and to tertiapin, a blocker for Kir1.1 and Kir3.1/3.4 channels. PCR and Western blot analysis show prominent expression of Kir4.1 in SCA, and immunocytochemistry shows localization Kir4.1 channels to the plasma membrane. Kir4.1 protein levels show a developmental upregulation in vivo that parallels an increase in currents recorded over the same time period. Kir4.1 is highly expressed throughout most areas of the gray matter in spinal cord in vivo and recordings from spinal cord slices show prominent Kir currents. Electrophysiological recordings comparing SCA of wild‐type mice with those of homozygote Kir4.1 knockout mice confirm a complete and selective absence of Kir channels in the knockout mice, suggesting that Kir4.1 is the principle channel mediating the resting K+ conductance in SCA in vitro and in situ. © 2005 Wiley‐Liss, Inc.
Affective judgment and beneficial decision making: Ventromedial prefrontal activity correlates with performance in the Iowa Gambling Task
Authors: Northoff Georg , Grimm Simone , Boeker Heinz , Schmidt Conny , Bermpohl Felix , Heinzel Alexander , Hell Daniel , Boesiger Peter
Published: December 2005

Damasio proposes in his somatic marker theory that not only cognitive but also affective components are critical for decision making. Since affective judgment requires an interplay between affective and cognitive components, it might be considered a key process in decision making that has been linked to neural activity in ventromedial prefrontal cortex (VMPFC). Using functional magnetic resonance imaging (fMRI), we examined the relationship between VMPFC, emotionally (unexpected)‐ and cognitively (expected)‐accentuated affective judgment, and beneficial decision making (Iowa Gambling Task; IGT) in healthy subjects. Neuronal activity in the VMPFC during unexpected affective judgment significantly correlated with both global and final performance in the IGT task. These findings suggest that the degree to which subjects recruit the VMPFC during affective judgment is related to beneficial performance in decision making in gambling. Hum Brain Mapp 2006. © 2005 Wiley‐Liss, Inc.
Subcellular localization, modification and protein complex formation of the cdk‐inhibitor p16 in Rb‐functional and Rb‐inactivated tumor cells
Authors: Nilsson Kristina , Landberg Göran
Published: December 2005

The cdk‐inhibitor p16 is a tumor suppressor gene that is inactivated in many forms of cancer. Despite numerous studies, the exact mechanism of regulation of p16 has not been clarified, although the status of retinoblastoma (Rb) seems to be one important factor that influences the p16 expression. The specificity and validity of cytoplasmic localization of p16 observed in some tumors has further been questioned. Here, by subcellular fractionation of Rb‐functional and Rb‐inactivated cell lines, we show that p16 indeed is expressed in the cytoplasm as well as in the nucleus. Post translational modifications of p16 in different subcellular compartments as well as its capacity to form protein complexes were further delineated. Two dimensional gel electrophoresis showed that two forms of p16 appeared in the cytoplasm, while only one form was detected in the nucleus. Samples of basal cell carcinoma and squamous cell carcinoma of the skin with either functional or non‐functional Rb also exhibited at least two forms of p16. In addition, cytoplasmic p16 bound cyclin dependent kinase (cdk)4/6, potentially indicating that p16 could have a function in the cytoplasm. © 2005 Wiley‐Liss, Inc.
Institutional research and new program development
Authors: Voorhees Richard A.
Published: December 2005

This chapter offers techniques that can help institutional researchers play a more active role in the process of creating and modifying instructional programs to meet workforce needs.
Graduate attributes and their development
Authors: Yorke Mantz , Harvey Lee
Published: December 2005

In this chapter, the authors argue that alignment of higher education with workforce needs should be based on careful action by institutions to embed skills and attributes within instructional programs.
Working with business and industry to enhance curriculum development and student employability
Authors: Junghagen Sven
Published: December 2005

Institutions benefit from working directly with employers to adjust their curricula and qualification frameworks to ensure student success in labor markets.
Kinetics and mechanism of the reduction of monochloramine by hydroxylamine and hydroxylammonium ion
Authors: Robinson David M. , Hoppe Todd J. , Paslay Timothy J. , Purser Gordon H.
Published: December 2005

The kinetics and mechanism by which monochloramine is reduced by hydroxylamine in aqueous solution over the pH range of 5–8 are reported. The reaction proceeds via two different mechanisms depending upon whether the hydroxylamine is protonated or unprotonated. When the hydroxylamine is protonated, the reaction stoichiometry is 1:1. The reaction stoichiometry becomes 3:1 (hydroxylamine:monochloramine) when the hydroxylamine is unprotonated. The principle products under both conditions are Cl–, NH+4, and N2O. The rate law is given by −[d[NH2Cl]/dt] = k+[NH3OH+][NH2Cl] + k0[NH2OH][NH2Cl]. At an ionic strength of 1.2 M, at 25°C, and under pseudo‐first‐order conditions, k+= (1.03 ± 0.06) ×103 L · mol−1 · s−1 and k0=91 ± 15 L · mol−1 · s−1. Isotopic studies demonstrate that both nitrogen atoms in the N2O come from the NH2OH/NH3OH+. Activation parameters for the reaction determined at pH 5.1 and 8.0 at an ionic strength of 1.2 M were found to be ΔH‡ = 36 ± 3 kJ · mol–1 and Δ S‡ = −66 ± 9 J · K−1 · mol−1, and Δ H‡ = 12 ± 2 kJ · mol−1 and Δ S‡ = −168 ± 6 J · K−1 · mol−1, respectively, and confirm that the transition states are significantly different for the two reaction pathways. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 124–135, 2006
Kinetics of Fe(II) reduction of cis‐halogeno(dodecylamine) bis(ethylenediamine)‐ cobalt(III) complex ion in aqueous solutions
Authors: Santhakumar K. , Kumaraguru N. , Arunachalam S. , Arumugham M. N.
Published: December 2005

Kinetics of reduction of the surfactant complex ions, cis‐chloro/bromo (dodecylamine)bis(ethylenediamine)cobalt(III) by iron(II) in aqueous solution was studied at 303, 308, and 313 K by spectrophotometry method under pseudo‐first‐order conditions, using an excess of the reductant. The second‐order rate constant remains constant below critical micelle concentration (cmc), but increases with cobalt(III) concentration above cmc, and the presence of aggregation of the complex itself alters the reaction rate. The rate of reaction was not affected by the added [H+]. Variation of ionic strength (μ) influences the reaction rate. Activation and thermodynamic parameters have been computed. It is suggested that the reaction of Fe2+ (aq) with cobalt(III) complex proceeds by the inner‐sphere mechanism. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 98–105, 2006
The elimination kinetics and mechanisms of ethyl piperidine‐3‐carboxylate, ethyl 1‐methylpiperidine‐3‐carboxylate, and ethyl 3‐(piperidin‐1‐yl)propionate in the gas phase
Authors: Monsalve Angiebelk , Rosas Felix , Tosta María , Herize Armando , Domínguez Rosa M. , Brusco Doris , Chuchani Gabriel
Published: December 2005

The gas‐phase elimination kinetics of the above‐mentioned compounds were determined in a static reaction system over the temperature range of 369–450.3°C and pressure range of 29–103.5 Torr. The reactions are homogeneous, unimolecular, and obey a first‐order rate law. The rate coefficients are given by the following Arrhenius expressions: ethyl 3‐(piperidin‐1‐yl) propionate, log k1(s−1) = (12.79 ± 0.16) − (199.7 ± 2.0) kJ mol−1 (2.303 RT)−1; ethyl 1‐methylpiperidine‐3‐carboxylate, log k1(s−1) = (13.07 ± 0.12)–(212.8 ± 1.6) kJ mol−1 (2.303 RT)−1; ethyl piperidine‐3‐carboxylate, log k1(s−1) = (13.12 ± 0.13) − (210.4 ± 1.7) kJ mol−1 (2.303 RT)−1; and 3‐piperidine carboxylic acid, log k1(s−1) = (14.24 ± 0.17) − (234.4 ± 2.2) kJ mol−1 (2.303 RT)−1. The first step of decomposition of these esters is the formation of the corresponding carboxylic acids and ethylene through a concerted six‐membered cyclic transition state type of mechanism. The intermediate β‐amino acids decarboxylate as the α‐amino acids but in terms of a semipolar six‐membered cyclic transition state mechanism. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 106–114, 2006
Mn(III) oxidation of peptides: A mechanistic investigation of kinetic variations in hydrophobic‐induced oxidation of tetrapeptides of elastin sequences
Authors: Srinivasa G. R. , Abiraj K. , Baba A. Ramesha , Gowda D. Channe
Published: December 2005

Four tetrapeptide analogues of elastin sequences, glycyl‐glycyl‐alanyl‐proline (GGAP), glycyl‐glycyl‐valyl‐proline (GGVP), glycyl‐glycyl‐isoleucyl‐proline (GGIP), and glycyl‐glycyl‐phenylalanyl‐proline (GGFP) were synthesized, based on their increasing order of hydrophobicity, by a classical solution phase method and were characterized. These tetrapeptides (TETPs) were oxidized using Mn(OAc)3 in 25% acetic acid at 298 K, and the kinetics of the reaction was monitored spectrophotometrically at λmax = 400 nm. A first‐order dependence of rate on each of [Mn(OAc)3], [OAc−], and substrate [TETP], an inverse order dependence on [H+], has been observed. The rate is independent of [Mn(II)]. However, an inverse order dependence on varying the dielectric constant using various percentages (v/v) of acetic acid has also been observed, and but addition of anions such as Cl− and ClO4− has insignificant effect on the rate. Activation parameters have been evaluated using the Arrhenius and Erying plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving [Mn(OAc)4]− has been proposed. An apparent correlation was noted between the rate of oxidation of these TETPs by Mn(III) in the presence of sulfate ions in sulfuric acid medium and Mn(OAc)3 in the acetic acid medium. The rate of oxidation with Mn(OAc)3 was observed to be slower than with the former. The rate of oxidation of GGFP was found to be higher than GGIP, GGVP, and GGAP. This may be due to the presence of an aromatic side chain and/or because of the increased hydrophobicity. The overall order of rate of oxidation of TETPs is GGFP > GGIP > GGVP > GGAP, which also represents an increasing order of their hydrophobicity. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 115–123, 2006
Photoinduced phenomena in thin films of chalcogenide
system Ga-Ge-S: a role of oxidation
Authors: Povolotskiy A V , Borisov E N , Ivanova T Yu , Manshina A A
Published: December 2005

Thin films of the chalcogenide glassy system
15(Ga2S3) - 85(GeS2) were deposited by ultra violet (UV)
laser ablation method. Optical absorption edge and refractive
index of the films were studied. It was found that optical
properties of the as-deposited (fresh deposited) films exhibit
modification with time (ageing phenomenon). Photoinduced changes
of the optical properties of the films were studied after films
exposure to sub-bandgap, and independently super-bandgap
monochromatic radiation. Considerable change of the optical
parameters of the films - photobleaching (blue shift of the
optical absorption edge position) and decreasing of the refractive
index as a result of laser illumination was found in both cases.
The reason of photobleaching and ageing phenomena is supposed to
be the same. These phenomena can be associated with the films
oxidation.
Ionization of a model quantum system by a single mode
electromagnetic cavity field
Authors: Tikhonova O V , Popov A M
Published: December 2005

The ionization of a model atom in a strong single-mode
non-classical electromagnetic field is studied beyond the
perturbation approach using the model of ``one discrete level +
continuum'' for the atom. Explicit analytical expressions for the
time-dependent probability of atomic ionization are obtained for
different initial states of radiative field: Fock state, coherent
wave packet, squeezed vacuum state. The results are compared to
the ionization decay of discrete atomic level in a classical light
field, and are analyzed for different mean number of radiative
photons. The time-dependent distribution of the quantized field
over photon number states is examined.
Imaging of QDs-labeled tumors in small animals by fluorescence diffuse tomography
Authors: Turchin I V , Balalaeva I V , Vasil'ev R B , Zlomanov V P , Plehanov V I , Orlova A G , Zagaynova E V , Kamensky V A , Kleshnin M S , Shirmanova M V , Dorofeev S G , Dirin D N
Published: December 2005

Quantum dots (QD) are a new class of fluorescence labels with properties and biomedical applications that are not available with traditional organic dyes and fluorescent proteins. The unique optical properties of QDs (high absorption, quantum yield and emission spanning to near IR) make them attractive asin vivomarkers for deep-tissue imaging. Different types of optical tomography allow imaging of fluorescent-labeled tumors located deep in human or animal tissue. In this work, preliminary results of the fluorescent diffuse tomography (FDT) method in application to CdTe/CdSe-core/shell fluorescing nanocrystals are reported. In our experiments we utilized low-frequency amplitude modulation (1 kHz) of the second harmonic of Nd:YAG laser (532 nm). The transilluminative configuration was used in the setup. Results of post mortem experiments with capsules containing QDs placed into esophagus of small animals to simulate labeled tumor are shown. An algorithm of processing fluorescent image based on calculating zero of maximum curvature has been applied to detect fluorescent inclusions boundaries on the image. This work demonstrates potential capabilities of the FDT method for imaging of deep fluorescent tumors in human tissue or animal models of human cancer.
Four-photon laser spectroscopy of solids in 0–0.15 THz
Authors: Bunkin A F , Pershin S M , Nurmatov A A
Published: December 2005

Four-photon coherent spectroscopy of fused quartz,
crown glass K8 and NaCl crystal in 0–5 cm-1 have been done.
It was established that the spectra contain the Brillouin
resonances on longitudinal and transversal hypersound, as well as
distinct resonances at ∼1.6 cm-1, which can be
attributed to hydroxyl (OH) rotations. The fine structure of
Rayleigh wing scattering in fused quartz has been observed for the
first time. The detected lines 0.18 cm-1 and 0.37 cm-1
(5.4 and 11.1 GHz, respectively) are attributed to spheroidal
modes ν22 and ν32 of SiO2 spheres with the
diameter ∼760 nm.
Generalized Jacobian rings for open complete intersections
Authors: Asakura Masanori , Saito Shuji
Published: December 2005

In this paper, we develop the theory of Jacobian rings of open complete intersections, which are pairs (X, Z) whereXis a smooth complete intersection in the projective space andZis a simple normal crossing divisor inXwhose irreducible components are smooth hypersurface sections onX. Our Jacobian rings give an algebraic description of the cohomology of the open complementX – Zand it is a natural generalization of the Poincaré residue representation of the cohomology of a hypersurface originally invented by Griffiths. The main results generalize Macaulay's duality theorem and Donagi's symmetrizer lemma for usual Jacobian rings for hypersurfaces. A feature that distinguishes our generalized Jacobian rings from usual ones is that there are instances where duality fails to be perfect while the defect can be controlled explicitly by using the defining equations ofZinX. Two applications of the main results are given: One is the infinitesimal Torelli problem for open complete intersections. Another is an explicit bound for Nori's connectivity in case of complete intersections. The results have been applied also to study of algebraic cycles in several other works. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral analysis of fourth order differential operators I
Authors: Behncke Horst
Published: December 2005

We study the spectral theory of differential operators of the form

on ℒ2w (0, ∞). By means of asymptotic integration, estimates for the eigenfunctions andM ‐matrix are derived. Since the M ‐function is the Stieltjes transform of the spectral measure, spectral properties of τ are directly related to the asymptotics of the eigenfunctions. The method of asymptotic integration, however, excludes coefficients which are too oscillatory or whose derivatives decay too slowly. Consequently there is no singular continuous spectrum in all our cases. This was found earlier for Sturm–Liouville operators, for which theWKB method provides a good approximation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear approximation in α ‐modulation spaces
Authors: Borup Lasse , Nielsen Morten
Published: December 2005

The á ‐modulation spaces are a family of spaces that contain the Besov and modulation spaces as special cases. In this paper we prove that brushlet bases can be constructed to form unconditional and even greedy bases for the α ‐modulation spaces. We study m ‐term nonlinear approximation with brushlet bases, and give complete characterizations of the associated approximation spaces in terms of α ‐modulation spaces. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gleason's problem for harmonic mixed norm and Bloch spaces in convex domains
Authors: Hu Zhangjian
Published: December 2005

Let Ω ⊂ Rn be a bounded convex domain with C 2 boundary. Given 0 < p, q ≤ ∞ and a normal weight function φ (r ), let Hp,q,φ be the harmonic mixed norm space on Ω. In this paper we prove that Gleason's problem (Ω, a , Hp,q,φ ) is always solvable for any reference point a ∈ Ω. Also, Gleason's problem for the harmonic φ ‐Bloch (little φ ‐Bloch) space is solvable. The parallel results for the holomorphic functions on bounded convex domains in Cn are obtained. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence and asymptotic behavior of positive solutions of higher‐order quasilinear ordinary differential equations
Authors: Naito Manabu
Published: December 2005

The existence of non‐extreme positive solutions of n th‐order quasilinear ordinary differential equations is discussed. In particular, necessary and sufficient integral conditions for the existence of non‐extreme positive solutions are established for a certain class of equations. Basic results to a classical ordinary differential equation are generalized. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contribution of mass spectrometry to assess quality of milk‐based products
Authors: Guy Philippe A. , Fenaille François
Published: December 2005

The vast knowledge of milk chemistry has been extensively used by the dairy manufacturing industry to develop and optimize the modern technology required to produce high‐quality milk products to which we are accustomed. A thorough understanding of the chemistry of milk and its numerous components is essential for designing processing equipment and conditions needed for the manufacture and distribution of high‐quality dairy products. Knowledge and application of milk chemistry is also indispensable for fractionating milk into its principal components for use as functional and nutritional ingredients by the food industry. For all these reasons, powerful analytical methods are required. Because of the complexity of the milk matrix, mass spectrometry, coupled or not to separation techniques, constitutes a key tool in this area. In the present manuscript, we review the contribution and potentialities of mass spectrometry‐based techniques to assess quality of milk‐based products. © 2005 Wiley Periodicals, Inc. Mass Spec Rev 25:290–326, 2006
Phenotypic changes associated with DYNACTIN‐2 (DCTN2) over expression characterise SJSA‐1 osteosarcoma cells
Authors: Bransfield Kieran L. , Askham Jon M. , Leek Jack P. , Robinson Philip A. , Mighell Alan J.
Published: December 2005

DYNACTIN‐2 (DCTN2) localises to chromosome 12q13‐q15, a region prone to stable amplification in several cancers. Transient DCTN2 overexpression has a significant impact on cellular phenotype primarily due to disruption of the DYNEIN‐dynactin motor. Changes reported include alterations of microtubule‐directed movement of molecular (e.g. TP53) and organelle (e.g. Golgi) cargoes towards the nucleus, centrosome biology, cellular movement and mitosis with a potential predisposition to mitotic block and polyploidy. These changes would be expected to be of relevance to carcinogenesis. To investigate this, we report the first study of DCTN2 genomic amplification and sustained DCTN2 overexpression in cancer cells. QFMPCR was employed to characterise the extent of chromosome 12q13‐q15 amplicons in SJSA‐1, SJRH30, U373MG and CCF‐STTG1 cancer cells. DCTN2 amplification was present in SJSA‐1, U373MG and SJRH30 cells, yet was incomplete at the 5′‐end in SJRH30 cells. Only SJSA‐1 cells were characterised by DCTN2 overexpression on Western blot analyses. Microscopy studies distinguished SJSA‐1 cells by greater DCTN2 immunofluorescence and diminished centrosome and 58K protein Golgi‐marker focus compared to SJRH30 cells. Indirect evidence derived from the published work of others indicated that TP53 transport into the nucleus was unimpaired. Furthermore, we observed that SJSA‐1 cells were easy to propagate. In conclusion, persistent DCTN2 overexpression can be tolerated in SJSA‐1 cancer cells despite phenotypic abnormalities predicted from transient overexpression studies. This preliminary study does not support a major role for DCTN2 overexpression in carcinogenesis, although further studies would be necessary to confirm this. © 2005 Wiley‐Liss, Inc.
Apple flavonoids inhibit growth of HT29 human colon cancer cells and modulate expression of genes involved in the biotransformation of xenobiotics
Authors: Veeriah Selvaraju , Kautenburger Tanja , Habermann Nina , Sauer Julia , Dietrich Helmut , Will Frank , Pool‐Zobel Beatrice Louise
Published: December 2005

Flavonoids from fruits and vegetables probably reduce risks of diseases associated with oxidative stress, including cancer. Apples contain significant amounts of flavonoids with antioxidative potential. The objectives of this study were to investigate such compounds for properties associated with reduction of cancer risks. We report herein that apple flavonoids from an apple extract (AE) inhibit colon cancer cell growth and significantly modulate expression of genes related to xenobiotic metabolism. HT29 cells were treated with AE at concentrations delivering 5–50 µM of one of the major ingredients, phloridzin (“phloridzin‐equivalents,” Ph.E), to the cell culture medium, with a synthetic flavonoid mixture mimicking the composition of the AE or with 5–100 µM individual flavonoids. HT29 cell growth was inhibited by the complex extract and by the mixture. HT29 cells were treated with nontoxic doses of the AE (30 µM, Ph.E) and after 24 h total RNA was isolated to elucidate patterns of gene expression using a human cDNA‐microarray (SuperArray®) spotted with 96 genes of drug metabolism. Treatment with AE resulted in an upregulation of several genes (GSTP1, GSSTT2, MGST2, CYCP4F3, CHST5, CHST6, and CHST7) and downregulation of EPHX1, in comparison to the medium controls. The enhanced transcriptional activity of GSTP1 and GSTT2 genes was confirmed with real‐time qRT‐PCR. On the basis of the pattern of differential gene expression found here, we conclude that apple flavonoids modulate toxicological defense against colon cancer risk factors. In addition to the inhibition of tumor cell proliferation, this could be a mechanism of cancer risk reduction. © 2005 Wiley‐Liss, Inc.
Soy extract has different effects compared with the isolated isoflavones on the proteome of homocysteine‐stressed endothelial cells
Authors: Fuchs Dagmar , Dirscherl Barbara , Schroot Joyce H. , Daniel Hannelore , Wenzel Uwe
Published: December 2005

Epidemiological studies suggest that soy consumption may provide a protection in the development and progression of atherosclerosis. It is under debate, however, whether the soy isoflavones or other compounds are the “active principle”. As apoptosis is a driving force in the process of atherosclerosis, we tested whether a soy extract or a combination of the two predominant isoflavones genistein and daidzein, in concentrations as found in the extract, exert similar or different effects on apoptosis in EA.hy 926 endothelial cells after exposure to the endothelial stressor homocysteine. Plasma membrane disintegration and nuclear fragmentation served as relevant apoptosis markers. To assess whether the extract and the genistein/daidzein mixture differently affect cellular target proteins changed in amount by homocysteine treatment, proteome analysis was performed by two‐dimensional gel‐electrophoresis and peptide mass fingerprinting of regulated protein spots. Homocysteine induced apoptosis in the cells, and both extract and genistein/daidzein inhibited apoptosis to a comparable extent. Whereas the extract prevented for 10 proteins the changes in expression levels as caused by homocysteine, the genistein/daidzein mixture reversed the homocysteine effects on the proteome for 13 proteins. The cytoskeletal protein matrin 3 and a U5 snRNP‐specific 40‐kDa protein were the only protein entities where both extract and genistein/daidzein reversed the homocysteine‐induced changes in a common way. In conclusion, our studies provide evidence that an isoflavone containing soy extract and isolated isoflavones, despite similar effects on inhibition of homocysteine‐induced apoptosis in endothelial cells, affect a quite different spectrum of cellular target proteins.
Age‐related morphological changes in skeletal muscle cells of acid α‐glucosidase knockout mice
Authors: Hesselink Reinout P. , Schaart Gert , Wagenmakers Anton J.M. , Drost Maarten R. , van der Vusse Ger J.
Published: December 2005

Glycogen storage disease type II (GSDII), caused by a genetic defect in acid α‐glucosidase (AGLU), leads to a decline in muscle contractility caused by both muscle wasting and a decrease in muscle quality, i.e., force generated per unit muscle mass. A previous study has shown that loss of muscle mass can only explain one‐third of the decrease in contractile performance. Here we report on changes in the intramyocellular structural organization in a mouse knockout model (AGLU−/− mice) as a possible cause for the decline in muscle quality. Swollen, glycogen‐filled lysosomes and centrally localized cores with cellular debris partially contribute to the decline in muscle quality. Altered localization and deposition of cytoskeletal proteins desmin and titin may reflect adaptive mechanisms at the age of 13 months, but a decline in quality at 20 months of age. The early deposition of lipofuscin in AGLU‐deficient myocytes (13 months) is most likely a reflection of enhanced oxidative stress, which may also affect muscle quality. These collective findings, on the one hand, may explain the decrease in tissue quality and, on the other, may represent markers for efficacy of therapeutic interventions to restore muscle function in patients suffering from GSDII. Muscle Nerve, 2005
Mitochondrial dysfunction and amyotrophic lateral sclerosis
Authors: Hervias Isabel , Beal M. Flint , Manfredi Giovanni
Published: December 2005

The causes of motor neuron death in amyotrophic lateral sclerosis (ALS) are still unknown. Several lines of evidence suggest that mitochondrial dysfunction may be involved in the pathogenesis of ALS. Biochemical and morphological mitochondrial abnormalities have been demonstrated in postmortem spinal cords of ALS patients. Furthermore, in transgenic mice expressing mutant Cu,Zn‐superoxide dismutase (SOD1), the antioxidant enzyme associated with familial ALS (FALS), mitochondrial abnormalities precede the disease onset, suggesting that mitochondrial dysfunction is causally involved in the pathogenesis of SOD1‐FALS. Despite this evidence, it is not yet fully understood how mutant SOD1 damages mitochondria. Recent work has demonstrated that a portion of mutant SOD1 is localized in mitochondria, both in transgenic mice and in FALS patients, where it forms proteinaceous aggregates. These findings have opened new avenues of investigation addressing the hypothesis that mutant SOD1 may directly damage mitochondria. Major future challenges will be to better understand the mechanisms and the consequences of mitochondrial dysfunction in ALS. If mitochondrial dysfunction is convincingly involved in ALS pathogenesis, either as a primary cause or as contributing factor, it is likely to become a novel target for therapeutic intervention. Muscle Nerve, 2006
Systemic oxybutynin decreases afferent activity of the pelvic nerve of the rat: New insights into the working mechanism of antimuscarinics
Authors: De Laet Kevin , De Wachter Stefan , Wyndaele Jean‐Jacques
Published: December 2005

Aims

In a rat model, intravesical oxybutynin was recently shown to suppress pelvic afferent nerves. This study evaluates if a similar effect exists after systemic administration of oxybutynin.

Methods

Twenty‐four single afferent bladder nerves were identified in 15 rats. Based on their conduction velocities they were grouped as C or Aδ fibers. Bladder filling parameters and afferent nerve spike rate were simultaneously recorded 30 min before administration of saline (nine fibers) or oxybutynin (15 fibers, 1 mg/kg), and again 30, 60, 90, 120, and 150 min after systemic saline or drug administration.

Results

No change in C or Aδ afferent spike rate was observed after saline injection (P > 0.90). In the study group, a decrease in afferent activity was noted after systemic administration of oxybutynin for C fibers, which were statistically significant 90 (P < 0.004) and 120 min (P < 0.028) after drug delivery. After 150 min, the spike rate was still lower compared to the baseline filling, without reaching the level of significance (P > 0.09). For the Aδ fibers the decrease in afferent spike rate was already significant at 30 min (P < 0.005) and remained significant during all subsequent fillings (P < 0.012). To avoid a possible confounding influence of the bladder compliance, which increased significantly after injection of oxybutynin (P < 0.011), afferent activity during bladder filling was recalculated. Normalized afferent sensitivity of C and Aδ fibers decreased significantly after injection of oxybutynin. This means that the decrease in afferent spike rate is not the result of an increased compliance.

Conclusions

The findings of this study strongly suggest that oxybutynin directly or indirectly influences bladder sensory nerves, inhibiting the afferent part of the micturition reflex. Neurourol Urodynam. © 2005 Wiley‐Liss, Inc.
Efficient simulation of 3D fatigue crack growth based on boundary elements
Authors: Kolk K. , Kuhn G.
Published: December 2005

The three‐dimensional simulation of fatigue crack growth under the consideration of 3D effects is presented to follow complex crack paths as realistic as possible from the macroscopic point of view. This aim is mainly based on two aspects. Firstly, an accurate stress analysis is performed by the boundary element method in terms of the 3D Dual BEM. Secondly, a suitable 3D crack growth criterion based on experimental observations is utilized. Due to the non‐linearity of crack growth the whole procedure is embedded in an advanced incremental crack growth algorithm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of crack density due to fragmentation of brittle ellipsoidal inhomogeneities
Authors: Korobeinik M. , Le K. C. , Hackl K.
Published: December 2005

An estimation is found for the energy release due to fragmentation of a brittle inhomogeneity of ellipsoidal shape embedded in a ductile matrix under remote static loading.The energy release calculated for prolate spheroidal inhomogeneities is used in the balance of energy to determine the crack density. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Short Crack Propagation ‐ Transition from Stage I to Stage II
Authors: K?nkler B. , Fritzen C.‐P. , D?ber O. , Krupp U. , Christ H.‐J.
Published: December 2005

The life‐time of cyclically loaded components with smooth surfaces is mainly determined by the initiation and propagation of microstructurally short fatigue cracks. The phase of short crack propagation can be subdivided into crack growth along single slip bands (stage I, in the direction of maximum shear stress in front of the crack tip) and the growth along alternating slip bands (stage II, perpendicular to the direction of maximum normal stress). Hence, the propagation starts in a single grain and continues through several grains in stage I. Then, additional slip bands are activated and the crack grows on alternating glide planes perpendicular to the direction of maximum normal stress. During the whole propagation process of the still relatively short crack, the plastic deformation on slip bands is blocked by grain boundaries. Due to the strong interaction with the microstructure, a description of the short crack propagation based on linear elastic fracture mechanics is not possible. Thus, an extended two‐dimensional yield‐strip model [1] based on the ideas of Navarro and de los Rios [2] has been developed. The boundary‐element method is used to calculate the displacements along the crack, treating the plastic zones in front of the crack tip as yield strips. Each boundary element consists of a mathematical dislocation at its beginning and its end, describing a constant normal and tangential displacement in the element. Geometrical crack closure can be considered by constraints allowing only positive normal displacements within the crack elements. The model is extended to the transition of stage I crack growth on single slip systems to crack propagation on multiple slip systems, which is presented here. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Boundary Finite Element Method for the Efficient Computation of Orders and Modes of Three‐Dimensional Stress Singularities
Authors: Longeru Markus , Mittelstedt Christian , Becker Wilfried
Published: December 2005

In this contribution the Boundary Finite Element Method (BFEM) is employed for the computation of the orders of stress singularities for several three‐dimensional stress concentration problems in linear elastic fracture mechanics. The BFEM combines the advantages of both the FEM and the BEM: while only a discretization on a structural boundary is required, the actual surface mesh consists of standard displacement based finite elements. In contrast to the BEM, no fundamental solution is required. The BFEM is an ef.cient analysis tool which leads to highly accurate results with significantly lesser computational effort when compared to e.g. standard FEM procedures. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of Material Forces to Hyperelastodynamics
Authors: Timmel Mario , Kaliske Michael , Kolling Stefan , Mueller Ralf
Published: December 2005

In the framework of numerical simulation, the analysis of fracture and damage mechanisms play an increasing role. In this context, the configurational force method is an useful tool for investigating structures with the finite element method [1] to predict the material behaviour more precisely. In this paper, we discuss the configurational forces in the context of high strain rate loaded hyperelastic structures [6]. Balance of momentum in the material space and the weak formulation are shown with focus on the explicite finite element method. Finally, an application will be presented based on a detailed treatment of structures subjected to short time loading. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiscale Modelling Of Shape‐Memory Alloys
Authors: Bartel Thorsten , Hackl Klaus
Published: December 2005

This work is dealing with the modelling and simulation of shape‐memory alloys by taking into account the different scales which have a bearing on the material behaviour. Particularly we focus on the combination of all these scales in order to formulate one closed, physically well motivated model, which is capable to represent the characteristic phenomena of this kind of material. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aerated autoclaved concrete: Stochastic structure model and elastic properties
Authors: Kadaschewitsch Ilja , Stoyan Dietrich
Published: December 2005

Aerated autoclaved concrete (AAC) is a modern and important construction material, whose elastic properties are primarily defined by its porosity. The possibility to predict elastic properties of AAC based on the voids distribution is very important. The report describes simulations of the mechanical properties of AAC, based on a stochastic‐geometric model of its structure. The model is the well‐known “cherry‐pit” model, which presents a random system of partially overlapping spheres. In the mechanical analysis the solid phase is approximated by a network model with the help of the so‐called radical tessellation with respect to the hard spheres of the “cherry‐pit” model. The network edges are modelled in ANSYS as 3D beams. In this approach, the discretized elements (the edges) have in distinction to FE calculations with small polyhedral same dimension as the air voids and so the numerical costs can be drastically reduced. The FE simulations calculate the elastic constants and energy concentrations, which are responsible for the material failures, in large samples. Comparisons with fracture tests showed good matching between simulations and experiments. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)