bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further application of hybrid solution to another form of Boussinesq equations and comparisons
Authors: Erduran K. S. 
Published: August 2006

AbstractRecently, a new hybrid scheme is introduced for the solution of the Boussinesq equations. In this study, the hybrid scheme is used to solve another form of the Boussinesq equations. The hybrid solution is composed of finite‐volume and finite difference method. The finite‐volume method is applied to conservative part of the governing equations, whereas the higher order Boussinesq terms are discretized using the finite‐difference scheme. Fourth‐order accuracy is provided in both time and space. The solution is then applied to several test cases, which are taken from the previous studies. The results of this study are compared with experimental and theoretical results as well as those of the previous ones. The comparisons indicate that the Boussinesq equations solved here and in the previous study produce quite similar results. Copyright © 2006 John Wiley & Sons, Ltd.
Integrated radial basis functions‐based differential quadrature method and its performance
Authors: Shu C. , Wu Y. L. 
Published: August 2006

AbstractIn this paper, indirect radial basis function networks (IRBFN) proposed by Nam and Tranh (Neural Networks 2001; 14(2):185–199; Appl. Math. Modelling 2003; 27:197–220) are incorporated into the differential quadrature (DQ) approximation of derivatives. For simplicity, this new variant of RBF‐DQ approach is named as iRBF‐DQ method. The proposed approach is validated by its application to solve the one‐dimensional Burger's equation, and simulate natural convection in a concentric annulus by solving Navier–Stokes equations. It was found that as compared to the benchmark data, the iRBF‐DQ approach can provide more accurate results than the original RBF‐DQ method. Copyright © 2006 John Wiley & Sons, Ltd.
Roles of two types of anion channels in glutamate release from mouse astrocytes under ischemic or osmotic stress
Authors: Liu Hong‐Tao , Tashmukhamedov Bekjan A. , Inoue Hana , Okada Yasunobu , Sabirov Ravshan Z. 
Published: August 2006

AbstractAstrocytes release glutamate upon hyperexcitation in the normal brain, and in response to pathologic insults such as ischemia and trauma. In our experiments, both hypotonic and ischemic stimuli caused the release of glutamate from cultured mouse astrocytes, which occurred with little or no contribution of gap junction hemichannels, vesicle‐mediated exocytosis, or reversed operation of the Na‐dependent glutamate transporter. Cell swelling and chemical ischemia activated, in cell‐attached membrane patches, anionic channels with large unitary conductance (∼400 pS) and inactivation kinetics at potentials more positive than +20 mV or more negative than −20 mV. These properties are different from those of volume‐sensitive outwardly rectifying (VSOR) Cl− channels, which were also expressed in these cells and exhibited intermediate unitary conductance (∼80 pS) and inactivation kinetics at large positive potentials of more than +40 mV. Both maxi‐anion channels and VSOR Cl− channels were permeable to glutamate with permeability ratios of glutamate to chloride of 0.21 ± 0.07 and 0.15 ± 0.01, respectively. However, the release of glutamate was significantly more sensitive to Gd3+, a blocker of maxi‐anion channels, than to phloretin, a blocker of VSOR Cl− channels. We conclude that these two channels jointly represent a major conductive pathway for the release of glutamate from swollen and ischemia‐challenged astrocytes, with the contribution of maxi‐anion channels being predominant. © 2006 Wiley‐Liss, Inc.
Prudence and optimal prevention for health risks
Authors: Courbage Christophe , Rey Béatrice 
Published: August 2006

AbstractEmpirical evidence suggests the existence of a positive relationship between fear of sickness (FS) – as measured by the level of future utility lost when sickness occurs – and the level of effort to prevent the occurrence of sickness. By looking theoretically at this issue, we develop new results on the determinants of optimal prevention for health risks. In particular, we show that a sufficient condition to pursue more prevention for an individual with a higher FS than another is to have lower prudence in Kimball's (1990) sense, whatever the distribution of risk. These findings reinforce the role of prudence as a main determinant of the optimal level of prevention. Copyright © 2006 John Wiley & Sons, Ltd.
Decellularized placental matrices for adipose tissue engineering
Authors: Flynn Lauren , Semple John L. , Woodhouse Kimberly A. 
Published: August 2006

AbstractA tissue‐engineered adipose substitute would be invaluable to plastic surgeons for reconstructive, corrective, and cosmetic procedures. This work involves the design of a scaffold for soft tissue augmentation incorporating the decellularized extracellular matrix (ECM) of human placenta. We have developed a protocol to decellularize an intact, large segment (8 cm by 8 cm) of the human placenta. To facilitate the complete decellularization of the dense matrix, a system was designed to perfuse the required chemicals into the placenta via the existing vasculature. Following processing, the original architecture of the placental ECM was preserved, including an intact vascular network. Histological, immunohistochemical, and scanning electron microscopic analyses confirmed the removal of the cells and cellular debris and characterized the composition and structure of the matrix. In vitro cell culture experimentation showed that the placental decellular matrix (PDM) could facilitate the adhesion of primary human adipose precursor cells at early time points. The PDM has great potential for use as a scaffold for adipose tissue engineering, as the placenta is a rich source of human ECM components that can be readily harvested without harm to the donor. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Apoptosis induced by troglitazone is both peroxisome proliferator‐activated receptor‐γ‐ and ERK‐dependent in human non‐small lung cancer cells
Authors: Li Mingyue , Lee Tak W. , Yim Anthony P.C. , Mok Tony S.K. , Chen George G. 
Published: August 2006

AbstractThe role of the peroxisome proliferator‐activated receptor‐gamma (PPARγ) in cell differentiation, cell‐cycle arrest, and apoptosis has attracted increasing attention. We have recently demonstrated that PPARγ ligands‐troglitazone (TGZ) induced apoptosis in lung cancer cells. In this report, we further studied the role of ERK1/2 in lung cancer cells treated by TGZ. The result demonstrated that TGZ induced PPARγ and ERK1/2 accumulation in the nucleus, in which the co‐localization of both proteins was found. The activation of ERK1/2 resulted in apoptosis via a mitochondrial pathway. Both PPARγ siRNA and U0126, a specific inhibitor of ERK1/2, were able to block these effects of TGZ, suggesting that apoptosis induced by TGZ was PPARγ and ERK1/2 dependent. Inhibition of ERK1/2 by U0126 also led to a significant decrease in the level of PPARγ, indicating a positive cross‐talk between PPARγ and ERK1/2 or an auto‐regulatory feedback mechanism to amplify the effect of ERK1/2 on cell growth arrest and apoptosis. In addition to ERK1/2, TGZ also activated Akt. Interestingly, inhibition of ERK1/2 prevented the activation of Akt whereas the suppression of Akt had no effect on ERK1/2, suggesting that Akt was not necessary for TGZ‐PPARγ‐ERK pathway. However, the inhibition of Akt promoted the release of cytochrome c, suggesting the activation of Akt may have a negative effect on apoptosis induced by TGZ. In conclusion, our study has demonstrated that TGZ, a synthetic PPARγ ligand, induced apoptosis in NCI‐H23 lung cancer cells via a mitochondrial pathway and this pathway was PPARγ and ERK1/2 dependent. J. Cell. Physiol. 209: 428–438, 2006. © 2006 Wiley‐Liss, Inc.
Transforming growth factor‐β1 and bone morphogenetic protein‐2 downregulate CaV3.1 channel expression in mouse C2C12 myoblasts
Authors: Avila Traudy , Andrade Arturo , Felix Ricardo 
Published: August 2006

AbstractIn the developing skeletal muscle, fusion of myoblasts and myotube formation is a process that involves Ca2+ influx through T‐type (CaV3) channels. Treatment of myoblasts with transforming growth factor‐β1 (TGF‐β1) and bone morphogenetic protein‐2 (BMP‐2) decreases the number of CaV3 channels in the plasma membrane and reduces myotube formation. In the current report, we examined whether the inhibitory actions of TGF‐β1 and BMP‐2 involve alterations in CaV3 mRNA expression in the myoblast C2C12 cell line. Using RT‐PCR, we found that CaV3.1 but not CaV3.2 and CaV3.3 transcripts are present in either undifferentiated or fusion competent C2C12 myoblasts. Semi‐quantitative analysis revealed a significant decrease of CaV3.1 mRNA expression in cells treated with TGF‐β1 and BMP‐2. In contrast, patch‐clamp recordings on HEK‐293 cells stably expressing recombinant CaV3.1 channels showed that T‐type currents were not affected by chronic exposure to the growth factors. These results suggest that muscle T‐channel downregulation by TGF‐β1 and BMP‐2 may be mediated by reduced transcription rather than through post‐transcriptional modifications of CaV3.1 channels. J. Cell. Physiol. 209: 448–456, 2006. © 2006 Wiley‐Liss, Inc.
Cyclic compression of chondrocytes modulates a purinergic calcium signalling pathway in a strain rate‐ and frequency‐dependent manner
Authors: Pingguan‐Murphy B. , El‐Azzeh M. , Bader D.L. , Knight M.M. 
Published: August 2006

AbstractMechanical loading modulates cartilage homeostasis through the control of matrix synthesis and catabolism. However, the mechanotransduction pathways through which chondrocytes detect different loading conditions remain unclear. The present study investigated the influence of cyclic compression on intracellular Ca2+signalling using the well‐characterised chondrocyte‐agarose model. Cells labelled with Fluo4 were visualised using confocal microscopy following a period of 10 cycles of compression between 0% and 10% strain. In unstrained agarose constructs, not subjected to cyclic compression, a subpopulation of approximately 45% of chondrocytes exhibited spontaneous global Ca2+transients with mean transient rise and fall times of 19.4 and 29.4 sec, respectively. Cyclic compression modulated global Ca2+signalling by increasing the percentage of cells exhibiting Ca2+transients (population modulation) and/or reducing the rise and fall times of these transients (transient shape modulation). The frequency and strain rate of compression differentially modulated these Ca2+signalling characteristics providing a potential mechanism through which chondrocytes may distinguish between different loading conditions. Treatment with apyrase, gadolinium and the P2 receptor blockers, suramin and basilen blue, significantly reduced the percentage of cells exhibiting Ca2+transients following cyclic compression, such that the mechanically induced upregulation of Ca2+signalling was completely abolished. Thus cyclic compression appears to activate a purinergic pathway involving the release of ATP followed by the activation of P2 receptors causing a combination of extracellular Ca2+influx and intracellular Ca2+release. Knowledge of this fundamental cartilage mechanotransduction pathway may lead to improved therapeutic strategies for the treatment of cartilage damage and disease. J. Cell. Physiol. 209: 389–397, 2006. © 2006 Wiley‐Liss, Inc.
Immortalized cell lines from mouse xiphisternum preserve chondrocyte phenotype
Authors: Majumdar Manas K. , Chockalingam Priya S. , Bhat Ramesh A. , Sheldon Richard , Keohan Cristin , Blanchet Tracey , Glasson Sonya , Morris Elisabeth A. 
Published: August 2006

AbstractChondrocytes are unique to cartilage and the study of these cells in vitro is important for advancing our understanding of the role of these cells in normal homeostasis and disease including osteoarthritis (OA). As there are limitations to the culture of primary chondrocytes, cell lines have been developed to overcome some of these obstacles. In this study, we developed a procedure to immortalize and characterize chondrocyte cell lines from mouse xiphisternum. The cells displayed a polygonal to fibroblastic morphology in monolayer culture. Gene expression studies using quantitative PCR showed that the cell lines responded to bone morphogenetic protein 2 (BMP‐2) by increased expression of matrix molecules, aggrecan, and type II collagen together with transcriptional factor, Sox9. Stimulation by IL‐1 results in the increased expression of catabolic effectors including MMP‐13, nitric oxide synthase, ADAMTS4, and ADAMTS5. Cells cultured in alginate responded to BMP‐2 by increased synthesis of proteoglycan (PG), a major matrix molecule of cartilage. IL‐1 treatment of cells in alginate results in increased release of PG into the conditioned media. Further analysis of the media showed the presence of Aggrecanase‐cleaved aggrecan fragments, a signature of matrix degradation. These results show that the xiphisternum chondrocyte cell lines preserve their chondrocyte phenotype cultured in either monolayer or 3‐dimensional alginate bead culture systems. In summary, this study describes the establishment of chondrocyte cell lines from the mouse xiphisternum that may be useful as a surrogate model system to understand chondrocyte biology and to shed light on the underlying mechanism of pathogenesis in OA. J. Cell. Physiol. 209: 551–559, 2006. © 2006 Wiley‐Liss, Inc.
Coloring quasi‐line graphs
Authors: Chudnovsky Maria , Ovetsky Alexandra 
Published: August 2006

AbstractA graph G is a quasi‐line graph if for every vertex v, the set of neighbors of v can be expressed as the union of two cliques. The class of quasi‐line graphs is a proper superset of the class of line graphs. A theorem of Shannon's implies that if G is a line graph, then it can be properly colored using no more than 3/2 ω(G) colors, where ω(G) is the size of the largest clique in G. In this article, we extend this result to all quasi‐line graphs. We also show that this bound is tight. © 2006 Wiley Periodicals, Inc. J Graph Theory
Synthesis of Three Types of Amphiphilic Poly(ethylene glycol)‐block‐Poly(sebacic anhydride) Copolymers and Studies of their Micellar Solutions
Authors: Zhang Na , Guo Sheng Rong , Li Hui Qin , Liu Li , Li Zong Hai , Gu Jian Ren 
Published: August 2006

AbstractSummary: Linear, three‐ and four‐armed block copolymers based on PEG and PSA were synthesized by melt polycondensation reactions. The CMC of the copolymer was measured using the dye solubilization method. The copolymers were found to self‐aggregate in water to form micelles above the CMC. The micellar solutions were prepared with different methods and investigated by DLS and AFM. The DLS method was used to measure the mean hydrodynamic diameters of the micelles. It was found that preparation method and condition of the micellar solution, as well as the structure and composition of the copolymer had effects on the hydrodynamic diameter of the copolymer micelles. AFM studies showed that the morphology of the micelle was spherical.Synthesis of 3‐armed stars based on poly(ethylene glycol) and poly(sebacic anhydride).magnified imageSynthesis of 3‐armed stars based on poly(ethylene glycol) and poly(sebacic anhydride).
Use of PP Grafted with Itaconic Acid as a New Compatibilizer for PP/Clay Nanocomposites
Authors: Moncada Edwin , Quijada Raúl , Lieberwirth Ingo , Yazdani‐Pedram Mehrdad 
Published: August 2006

AbstractSummary: Functionalized PP samples with different percentages of grafted IA, i.e., 0.7, 1 or 1.8 wt.‐%, with similar molecular weights were used as compatibilizers in PP/clay nanocomposites. PP nanocomposites containing 1 wt.‐% of organically modified clays, i.e., montmorillonite, natural hectorite and synthetic hectorite and 3 wt.‐% of grafted PP with three different percentages of grafted IA as compatibilizers and two commercial PP samples of different molecular weights were prepared by melt blending. The nanocomposites were characterized by XRD, TEM and tensile mechanical measurements. It was found that the molecular weight of PP used as matrix as well as the percentage of grafted IA of the compatibilizer affected the degree of intercalation/exfoliation of the clay and consequently the mechanical properties of the nanocomposites. Values of 2 137 MPa for the modulus and 51 MPa for the tensile strength were obtained when natural hectorite was used and 2 117 and 40 MPa were obtained when montmorillonite was used. A comparative study was carried out, where PP grafted with maleic anhydride was used as the compatibilizer. Inferior mechanical properties were obtained for nanocomposites prepared by using this compatibilizer, where values of 1 607 MPa for the tensile modulus and 43 MPa for tensile strength were obtained. This result indicated that IA‐grafted PP was far more efficient as compatibilizer for the formation of nanocomposites than commercially available maleic anhydride‐grafted PP.Model showing interaction of the organically modified clay with grafted PP used as compatibilizer.magnified imageModel showing interaction of the organically modified clay with grafted PP used as compatibilizer.
New DEFT sequences for the acquisition of one‐dimensional carbon NMR spectra of small unlabelled molecules
Authors: Piotto Martial , Bourdonneau Maryse , Elbayed Karim , Wieruszeski Jean‐Michel , Lippens Guy 
Published: August 2006

AbstractThe acquisition time and quality of 1D 13C{1H} spectra can be improved substantially by using a modified driven equilibrium Fourier transform (DEFT) sequence, which is specifically designed to compensate for the effects of B1 inhomogeneity, pulse miscalibration and frequency offsets. The new sequence, called uniform driven equilibrium Fourier transform (UDEFT), returns the carbon magnetization with a high accuracy along its equilibrium position after each transient is complete. Thus, the sequence allows the use of relaxation delays (RD), which are much shorter than the carbon T1 of the molecule, thereby speeding up the acquisition process of 1D 13C{1H} spectra. To achieve this level of performance, UDEFT employs a refocusing element constituted by a composite adiabatic carbon pulse surrounded by two 90° carbon pulses whose phases are designed to compensate for 90° pulse miscalibrations in an MLEV manner (90° +x − τ(FID)− 180+y(Adia)− τ− 90° +x − 180° +x(Adia)). A version of the UDEFT sequence allows recording 1D 13C{1H} spectra devoid of heteronuclear NOE by using a matched adiabatic 1H decoupling scheme where an even number of 180° adiabatic pulses is applied during the UDEFT module. Spectra of a solution of 300 mM camphor that contains some carbon nuclei with very long T1 relaxation times (90 s and 78 s) were acquired with 128 scans in 10 min using a 5 s relaxation delay. Copyright © 2006 John Wiley & Sons, Ltd.
Institutional influences on business power: how ‘privileged’ is the Business Council of Australia?
Authors: Bell Stephen 
Published: August 2006

AbstractThis paper explores the institutional and political dynamics of the Business Council of Australia (BCA), a unique form of big business association which relies on the active involvement of its one hundred or so CEO members. The paper argues that associations such as the BCA confront a range of serious institutional problems in their attempts to wield political power, or more modestly perhaps, policy influence. First, they confront a disconnect between ‘structural’ and ‘instrumentalist’ articulations of business power. The key source of business power resides in business control over the economy and the investment process, a form of power wielded at the company level not at the level of business associations. When engaged in instrumentalist or overt forms of political activism, the BCA also confronts serious collective action problems. It is also argued that the influence of the BCA seems to have declined over time and that this can partly be traced back to declining CEO commitment rooted in changing institutional and structural dynamics in the corporate world.Copyright © 2006 John Wiley & Sons, Ltd.
Redox‐sensitive modulation of CD45 expression in pancreatic acinar cells during acute pancreatitis
Authors: de Dios I , Ramudo L , García‐Montero AC , Manso MA 
Published: August 2006

AbstractCD45, a transmembrane protein tyrosine phosphatase required for signal transduction in leukocytes, has recently been found in pancreatic acinar cells. We have investigated the relationship between kinetic expression of CD45 on acinar cells during acute pancreatitis (AP) and the ability of these cells to produce tumour necrosis factor‐α (TNF‐α) through mechanisms sensitive to the cellular redox state. Flow cytometric analysis showed a significant decrease in the constitutive expression of CD45 in acinar cells from six hours onwards after inducing AP by bile‐pancreatic duct obstruction (BPDO) in parallel with a significant increase in acinar TNF‐α production. Changes in protein expression on the acinar cell surface preceded CD45 mRNA down‐regulation, which was not found until 12 hours after BPDO. N‐Acetylcysteine treatment delayed and reduced the down‐regulation of CD45 expression induced by AP and prevented acinar cells from producing TNF‐α. Our results show that CD45 expression is down‐regulated in acinar cells during acute pancreatitis by redox‐sensitive mechanisms, and they support the notion that CD45 negatively controls the production of cytokines in pancreatic acinar cells. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Creating and probing long‐range order in atomic clouds
Authors: von Cube C. , Slama S. , Kohler M. , Zimmermann C. , Courteille Ph.W. 
Published: August 2006

AbstractUltracold atoms interacting with the optical modes of a high‐Q optical ring cavity can synchronize their motion. The collective behavior makes the system interesting for quantum computing applications. This paper is devoted to the study of the collective coupling. We report on the first observation of a collective dynamics and on the realization of a laser, the gain mechanism of which is based on collective atomic recoil. We show that, if the atoms are subject to a friction force, starting from an unordered distribution they spontaneously form a moving density grating. Furthermore, we demonstrate that a 1D atomic density grating can be probed via Bragg scattering. By heterodyning the Bragg‐reflected light with a reference beam, we obtain detailed information on phase shifts induced by the Bragg scattering process.
Quantum state engineering with spins
Authors: Heidebrecht A. , Mende J. , Mehring M. 
Published: August 2006

AbstractMagnetic resonance methods and in particular Nuclear Magnetic Resonance in the liquid state were the first experimental techniques to implement quantum computing algorithms. The main drawbacks of these methods sofar have been the highly mixed nature of the quantum states and scalability issues. Recently, efforts have been made to address these problems by applying magnetic resonance to solid state systems at lower temperatures. In this contribution, we give an overview of our results on accurately controlling and measuring the quantum state of spin systems in the liquid and in particular in the solid state at low temperatures using Nuclear Magnetic Resonance and Electron Spin Resonance.
Improving the purity of one‐ and two‐qubit gates
Authors: Kohler S. , Hänggi P. 
Published: August 2006

AbstractWe investigate the influence of AC driving fields on the coherence properties of one‐ and two‐qubit gate operations. In both cases, we find that for suitable driving parameters, the gate purity improves significantly. A mapping of the time‐dependent system‐bath model to an effective static model provides analytical results. The resulting purity loss compares favorably with numerical results.