bluuebunny/crossref_metadata_2025 huggingface dataset:
A MULTIPHASE MODEL OF TUMOR AND TISSUE GROWTH INCLUDING CELL ADHESION AND PLASTIC REORGANIZATION
Authors: PREZIOSI LUIGI , VITALE GUIDO
Published: March 2011

The main aim of the paper is to embed the experimental results recently obtained studying the detachment force of single adhesion bonds in a multiphase model developed in the framework of mixture theory. In order to do that the microscopic information is upscaled to the macroscopic level to describe the dependence of some crucial terms appearing in the PDE model on the sub-cellular dynamics involving, for instance, the density of bonds on the membrane, the probability of bond rupture and the rate of bond formation. In fact, adhesion phenomena influence both the interaction forces among the constituents of the mixtures and the constitutive equation for the stress of the cellular components. Studying the former terms a relationship between interaction forces and relative velocity is found. The dynamics presents a behavior resembling the transition from epithelial to mesenchymal cells or from mesenchymal to ameboid motion, though the chemical cues triggering such transitions are not considered here. The latter terms are dealt with using the concept of evolving natural configurations consisting in decomposing in a multiplicative way the deformation gradient of the cellular constituent distinguishing the contributions due to growth, to cell rearrangement and to elastic deformation. This allows the description of situations in which if in some points the ensemble of cells is subject to a stress above a threshold, then locally some bonds may break and some others may form, giving rise to an internal reorganization of the tissue that allows to relax exceedingly high stresses.
ON THE CAUCHY PROBLEM FOR THE GYRO-WATER-BAG MODEL
Authors: BESSE NICOLAS
Published: March 2011

In this paper we prove the existence and uniqueness of classical solution for a system of PDEs recently developed in Refs. 60, 8, 10 and 11 to modelize the nonlinear gyrokinetic turbulence in magnetized plasma. From the analytical and numerical point of view this model is very promising because it allows to recover kinetic features (wave–particle interaction, Landau resonance) of the dynamic flow with the complexity of a multi-fluid model. This model, called the gyro-water-bag model, is derived from two-phase space variable reductions of the Vlasov equation through the existence of two underlying invariants. The first one, the magnetic moment, is adiabatic and the second, a geometric invariant named "water-bag", is exact and is just the direct consequence of the Liouville theorem.
ON THE ALEXANDER POLYNOMIAL OF PERIODIC LINKS
Authors: BAE YONGJU , LEE IN SOOK
Published: March 2011

In this paper, we express the Seifert matrix of a periodic link which is presented as the closure of a 4-tangle with some extra restrictions, in terms of the Seifert matrix of the quotient link. As a result, we give formulae for the Alexander polynomial and the determinant of such a periodic link.
BRIDGE PRESENTATIONS OF VIRTUAL KNOTS
Authors: HIRASAWA MIKAMI , KAMADA NAOKO , KAMADA SEIICHI
Published: March 2011

We study bridge presentations of virtual knots, and determine the virtual bridge numbers of pseudo-prime virtual knots with real crossing numbers less than 5, except two virtual knots.
BIQUANDLES OF SMALL SIZE AND SOME INVARIANTS OF VIRTUAL AND WELDED KNOTS
Authors: BARTHOLOMEW ANDREW , FENN ROGER
Published: March 2011

In this paper we give the results of a computer search for biracks of small size and we give various interpretations of these findings. The list includes biquandles, racks and quandles together with new invariants of welded knots and examples of welded knots which are shown to be non-trivial by the new invariants. These can be used to answer various questions concerning virtual and welded knots. As an application we reprove the result that the Burau map from braids to matrices is non-injective and give an example of a non-trivial virtual (welded) knot which cannot be distinguished from the unknot by any linear biquandles.
THE THIRD COHOMOLOGY GROUPS OF DIHEDRAL QUANDLES
Authors: MOCHIZUKI TAKURO
Published: March 2011

We compute the third cohomology group of a dihedral quandle of odd order with finite field coefficient, generalizing our previous work. In particular, we obtain many new examples of non-trivial 3-cocycles. We check non-triviality of the associated invariant for knots.
EXTENDING VAN COTT'S BOUNDS FOR THE τ AND s-INVARIANTS OF A SATELLITE KNOT
Authors: ROBERTS LAWRENCE
Published: March 2011

This paper generalizes Van Cott's bounds on the Heegaard–Floer τ-invariant and Rasmussen's s-invariant of cabled knots to apply to all satellite knots.
ON QUASI-MORPHISMS FROM KNOT AND BRAID INVARIANTS
Authors: BRANDENBURSKY MICHAEL
Published: March 2011

We study quasi-morphisms on the groups Pnof pure braids on n strings and on the group [Formula: see text] of compactly supported area-preserving diffeomorphisms of an open two-dimensional disk. We show that it is possible to build quasi-morphisms on Pnby using knot invariants which satisfy some special properties. In particular, we study quasi-morphisms which come from knot Floer homology and Khovanov-type homology. We then discuss possible variations of the Gambaudo–Ghys construction, using the above quasi-morphisms on Pnto build quasi-morphisms on the group [Formula: see text] of diffeomorphisms of a 2-disk.
AN INFINITE FAMILY OF CASSON HANDLES AND THE RASMUSSEN INVARIANT OF A KNOT
Authors: TANAKA TOSHIFUMI
Published: March 2011

By using Rasmussen's s-invariant derived from Khovanov homology, we give a combinatorial proof for the existence of countably many Casson handles.
AN IMPROVED MODEL FOR THE DIFFUSION OF OXYGEN INTO RESPIRING WOOD
Authors: NOWAK WERNER GEORG , HIETZ PETER
Published: March 2011

Diffusion is an essential component of gas exchange at the cellular and tissue level, and a mathematical analysis of diffusion is therefore important to model biological processes in many systems. When several factors affect diffusion, finding an explicit non-steady-state equation can be difficult or impossible. In an earlier work (J Biol Systems15:63–72), we described such a function for a system where oxygen diffuses from the air into a body that consumes oxygen, assuming that the exchange surface is flat. Here, an explicit solution is limited to the case where tissue oxygen consumption decreases linearly with oxygen concentration and reaches 0 only when all oxygen has been consumed. The objective of this article is the analysis of gas diffusion into a respiring tissue that is cylindrical, which applies to tree stems and is a more realistic approximation for many other organs. This approach differs from diffusion along a flat surface, resulting in formally completely different explicit solutions, and is more flexible allowing for different relationships between oxygen concentration and tissue oxygen consumption.
Alternatives to Traditional Repricing of Executive Stock Options
Authors: Yang Jerry T.
Published: March 2011

The main purpose of this paper is to examine two commonly used alternatives to traditional repricing (TR) of executive stock options (ESOs) in a dynamic agency model. TR practices have become obsolete since new accounting rules took effect in July 2000. To avoid associated variable accounting charges that cause uncertainty in future reported earnings, companies have tried several TR alternatives as solutions to rescuing underwater options. We justify the occurrence of TR alternatives and quantify the impact of the marking-to-market feature imbedded in the new accounting rules. We also propose an incentive measure which is comparable to the subjective value of ESOs claimed by Ingersoll, J (2006) to rank TR alternatives in terms of agent's incentive.
Transfer Pricing of Taiwan's Listing/OTC Enterprises Between Mainland China and Taiwan: Quantile Regression Analysis
Authors: Huang Chung-Jian , Kao Chau-Jung , Shyu So-De , Yu Chao-Hung
Published: March 2011

The main purpose of this paper is to explore the issue of enterprise's transfer pricing which has been noticed by tax administrations of many nations in recent years. The academia has also striven to develop models for interpreting transfer pricing and assessing transfer pricing profit of enterprises. A precise model is applied in this study to interpret enterprise's transfer pricing in practice. Furthermore, this model is also used to assess the transfer pricing profit of listing/OTC electronics companies in Taiwan and study the factors affecting transfer pricing profit. The empirical results show that material expense ratio significantly impacts transfer pricing profit. Corporate income tax expenses are positively and significantly correlated with net incomes of corporate transfer pricing transactions.

This study also finds that regardless of whether the net income of corporate transfer pricing transactions is high, medium, or low, the proportion of material costs is positively and significantly correlated with the net income of corporate transfer pricing transactions in all scenarios. Higher profit will be affected by exchange rate. This suggests that companies involved in wafer fabrication, IC packaging and testing, and DRAM packaging and testing (subcontractors with relatively low material costs) are less likely to be involved in transfer pricing decisions.
A NOTE ON B-COSEPARABLE GROUPS
Authors: ALBRECHT ULRICH , FRIEDENBERG STEFAN
Published: March 2011

Let B be a torsion-free finitely faithful S-group. This paper investigates the class of all torsion-free Abelian groups A with the property that Ext (A, B) is torsion-free. Our discussion is based on a natural extension of the concept of coseparability.
ASSOCIATION OF FEATURE GENE EXPRESSION WITH STRUCTURAL FINGERPRINTS OF CHEMICAL COMPOUNDS
Authors: LI YUN , TU KANG , ZHENG SIYUAN , WANG JINGFANG , LI YIXUE , HAO PEI , LI XUAN
Published: March 2011

Exploring the relationship between a chemical structure and its biological function is of great importance for drug discovery. For understanding the mechanisms of drug action, researchers traditionally focused on the molecular structures in the context of interactions with targets. The newly emerged high-throughput "omics" technology opened a new dimension to study the structure–function relationship of chemicals. Previous studies made attempts to introduce transcriptomics data into chemical function investigation. But little effort has been made to link structural fingerprints of compounds with defined intracellular functions, i.e. expression of particular genes and altered pathways. By integrating the chemical structural information with the gene expression profiles of chemical-treated cells, we developed a novel method to associate the structural difference between compounds with the expression of a definite set of genes, which were called feature genes. A subtraction protocol was designed to extract a minimum gene set related to chemical structural features, which can be utilized in practice as markers for drug screening. Case studies demonstrated that our approach is capable of finding feature genes associated with chemical structural fingerprints.
THE RELATION BETWEEN LOCAL UNITARY TRANSFORMATION INVARIANT AND PERFECT QUANTUM TELEPORTATION
Authors: ZHA XIN-WEI , SONG HAI-YANG , REN KUAN-FANG
Published: March 2011

We introduce a concept of local unitary (LU) transformation invariant operators which permits us to easily obtain arbitrary multi-qubit states LU transformation invariant. The general relation between the LU transformation invariant and perfect quantum teleportation is examined. The optimal match of measurement basis is given.
NON-COMMUTATIVE KERR BLACK HOLE
Authors: GREZIA ELISABETTA DI , ESPOSITO GIAMPIERO
Published: March 2011

This paper applies the first-order Seiberg–Witten map to evaluate the first-order non-commutative Kerr tetrad. The classical tetrad is taken to follow the locally non-rotating frame prescription. We also evaluate the tiny effect of non-commutativity on the efficiency of the Penrose process of rotational energy extraction from a black hole.
A RELATIVE TRACE FORMULA FOR A COMPACT RIEMANN SURFACE
Authors: MARTIN KIMBALL , MCKEE MARK , WAMBACH ERIC
Published: March 2011

We study a relative trace formula for a compact Riemann surface with respect to a closed geodesic C. This can be expressed as a relation between the period spectrum and the ortholength spectrum of C. This provides a new proof of asymptotic results for both the periods of Laplacian eigenforms along C as well estimates on the lengths of geodesic segments which start and end orthogonally on C. Variant trace formulas also lead to several simultaneous nonvanishing results for different periods.
CENTRAL VALUES OF DERIVATIVES OF DIRICHLET L-FUNCTIONS
Authors: BUI H. M. , MILINOVICH MICAH B.
Published: March 2011

Let [Formula: see text] be the set of even, primitive Dirichlet characters ( mod q). Using the mollifier method, we show that L(k)(½, χ) ≠ 0 for almost all the characters [Formula: see text] when k and q are large. Here L(s, χ) is the Dirichlet L-function associated to the character χ.
GOWERS UNIFORMITY NORM AND PSEUDORANDOM MEASURES OF THE PSEUDORANDOM BINARY SEQUENCES
Authors: LIU HUANING
Published: March 2011

Recently there has been much progress in the study of arithmetic progressions. An important tool in these developments is the Gowers uniformity norm. In this paper we study the Gowers norm for pseudorandom binary sequences, and establish some connections between these two subjects. Some examples are given to show that the "good" pseudorandom sequences have small Gowers norm. Furthermore, we introduce two large families of pseudorandom binary sequences constructed by the multiplicative inverse and additive character, and study the pseudorandom measures and the Gowers norm of these sequences by using the estimates of exponential sums and properties of the Vandermonde determinant. Our constructions are superior to the previous ones from some points of view.
A REFINEMENT OF KOBLITZ'S CONJECTURE
Authors: ZYWINA DAVID
Published: March 2011

Let E be an elliptic curve over the rationals. In 1988, Koblitz conjectured an asymptotic for the number of primes p for which the cardinality of the group of 𝔽p-points of E is prime. However, the constant occurring in his asymptotic does not take into account that the distributions of the |E(𝔽p)| need not be independent modulo distinct primes. We shall describe a corrected constant. We also take the opportunity to extend the scope of the original conjecture to ask how often |E(𝔽p)|/t is an integer and prime for a fixed positive integer t, and to consider elliptic curves over arbitrary number fields. Several worked out examples are provided to supply numerical evidence for the new conjecture.
ON PRIME-PERFECT NUMBERS
Authors: KNOPFMACHER ARNOLD , LUCA FLORIAN
Published: March 2011

We prove that the Diophantine equation [Formula: see text] has only finitely many positive integer solutions k, p1, …, pk, r1, …, rk, where p1, …, pk are distinct primes. If a positive integer n has prime factorization [Formula: see text], then [Formula: see text] represents the number of ordered factorizations of n into prime parts. Hence, solutions to the above Diophantine equation are designated as prime-perfect numbers.
THE DIGRAPH OF THE SQUARE MAPPING ON QUOTIENT RINGS OVER THE GAUSSIAN INTEGERS
Authors: MEEMARK YOTSANAN , MAINGAM NAWAPHON
Published: March 2011

In this work, we investigate the structure of the digraph [Formula: see text] associated with the square mapping on the ring of Gaussian integers by using the exponent of the unit group modulo γ. The formula for the fixed points of [Formula: see text] is established. Some connections of the lengths of cycles with the exponent of the unit group modulo γ are presented. Furthermore, we study the maximum distance from the cycle on each component.
CRITÈRES D'IRRÉDUCTIBILITÉ POUR LES REPRÉSENTATIONS DES COURBES ELLIPTIQUES
Authors: BILLEREY NICOLAS
Published: March 2011

Soit E une courbe elliptique définie sur un corps de nombres K. On dit qu'un nombre premier p est réductible pour le couple (E, K) si E admet une p-isogénie définie sur K. L'ensemble de tous ces nombres premiers est fini si et seulement si E n'a pas de multiplication complexe définie sur K. Dans cet article, on montre que l'ensemble des nombres premiers réductibles pour le couple (E, K) est contenu dans l'ensemble des diviseurs premiers d'une liste explicite d'entiers (dépendant de E et de K) dont une infinité d'entre eux est non nulle. Cela fournit un algorithme efficace de calcul dans le cas fini. D'autres critères moins généraux, mais néanmoins utiles sont donnés ainsi que de nombreux exemples numériques.

Let E be an elliptic curve defined over a number field K. We say that a prime number p is reducible for (E, K) if E admits a p-isogeny defined over K. The so-called reducible set of all such prime numbers is finite if and only if E does not have complex multiplication over K. In this paper, we prove that the reducible set is included in the set of prime divisors of an explicit list of integers (depending on E and K), infinitely many of them being non-zero. It provides an efficient algorithm for computing it in the finite case. Other less general but rather useful criteria are given, as well as many numerical examples.
ANALOGUES OF A TRANSFORMATION FORMULA OF RAMANUJAN
Authors: DIXIT ATUL
Published: March 2011

We derive two new analogues of a transformation formula of Ramanujan involving the Gamma function and Riemann zeta function present in his Lost Notebook. Both involve infinite series consisting of Hurwitz zeta functions and yield modular-type relations. As a special case of the first formula, we obtain an identity involving polygamma functions given by A. P. Guinand and as a limiting case of the second formula, we derive the transformation formula of Ramanujan.
TWO CONDITIONAL RESULTS ABOUT PRIMES IN SHORT INTERVALS
Authors: BAZZANELLA DANILO
Published: March 2011

In 1937, Ingham proved that ψ(x + xθ) - ψ(x) ~ xθ for x → ∞, under the assumption of the Lindelöf hypothesis for θ > 1/2. In this paper we examine how the above asymptotic formula holds by assuming in turn two different heuristic hypotheses. It must be stressed that both the hypotheses are implied by the Lindelöf hypothesis.
DIVISIBILITY PROPERTIES OF COEFFICIENTS OF WEIGHT 0 WEAKLY HOLOMORPHIC MODULAR FORMS
Authors: GRIFFIN MICHAEL
Published: March 2011

In 1949, Lehner showed that certain coefficients of the modular invariant j(τ) are divisible by high powers of small primes. Kolberg refined Lehner's results and proved congruences for these coefficients modulo high powers of these primes. We extend Lehner's and Kolberg's work to the elements of a canonical basis for the space of weight 0 weakly holomorphic modular forms.
PRIME DENSITY RESULTS FOR HECKE EIGENVALUES OF A SIEGEL CUSP FORM
Authors: SAHA ABHISHEK
Published: March 2011

Let F ∈ Sk( Sp (2g, ℤ)) be a cuspidal Siegel eigenform of genus g with normalized Hecke eigenvalues μF(n). Suppose that the associated automorphic representation πF is locally tempered everywhere. For each c > 0, we consider the set of primes p for which |μF(p)| ≥ c and we provide an explicit upper bound on the density of this set. In the case g = 2, we also provide an explicit upper bound on the density of the set of primes p for which μF(p) ≥ c.
ON ORDERS OF M(2, K) OVER A NON-ARCHIMEDEAN LOCAL FIELD
Authors: TU FANG-TING
Published: March 2011

Let K be a non-Archimedean local field. In this paper, we first show that if an order in M(2, K) is the intersection of (finitely many) maximal orders in M(2, K), then it is the intersection of at most three maximal orders. Using this result, we obtain a complete classification of orders in M(2, K) that are intersections of maximal orders.
THE 8-DISSECTION OF THE RAMANUJAN–GÖLLNITZ–GORDON CONTINUED FRACTION BY AN ITERATIVE METHOD
Authors: XIA ERNEST X. W. , YAO X. M.
Published: March 2011

In this paper, we present an iterative method to derive the 8-dissections of the Ramanujan–Göllnitz–Gordon continued fraction and its reciprocal which were first discovered by Hirschhorn.
DIFFERENTIAL EQUATIONS FOR CUBIC THETA FUNCTIONS
Authors: HUBER TIM
Published: March 2011

We show that the cubic theta functions satisfy two distinct coupled systems of nonlinear differential equations. The resulting relations are analogous to Ramanujan's differential equations for Eisenstein series on the full modular group. We deduce the cubic analogs presented here from trigonometric series identities arising in Ramanujan's original paper on Eisenstein series. Several consequences of these differential equations are established, including a short proof of a famous cubic theta function identity derived by J. M. Borwein and P. B. Borwein.
STRUCTURAL PARAMETERS AND OPTICAL CONSTANTS OF CdS NANOCRYSTALLINE THIN FILMS
Authors: VISWANATHAN B. , DHARMARAJA J. , BALAMURUGAN J.
Published: March 2011

Optical constants of cadmium sulfide (CdS) thin films were determined in the spectral range of 400–1200 nm from optical absorption and transmittance measurements for different bath temperatures. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) were the techniques used to determine the crystallite structure and morphology of the films. EDX images showed that a sample had a stoichiometric composition. The crystallite size and microstrain were calculated using the Williamson–Hall method. The optical band gap values of the films varied from 2.35 eV to 2.5 eV, depending on the bath temperature. Optical study was performed to calculate the refractive index (n), extinction coefficient (k), optical conductivity (σ), dielectric constant (real and imaginary), and optical band gap using transmission spectra. It has been observed that the conductivity of the synthesized films has a close relationship with the size of the crystallites. The optical conductivity and the crystallite size increase at a temperature of up to 70°C and then start decreasing when the temperature is still increased due to the change in phase from hexagonal to cubic in nature. Moreover, we observed that beyond this temperature the XRD peak shifts toward the nanoregion. The values of microstructure parameters change drastically, whereas the trend of optical constants remains the same.
SYNTHESIS OF CATALYST-FREE AND TEMPERATURE CONTROLLED MORPHOLOGIES OF CARBON NANOSTRUCTURES USING BOTANICAL HYDROCARBON: CASTOR OIL
Authors: KUMAR RAJESH , TIWARI R. S. , SRIVASTAVA O. N.
Published: March 2011

Castor oil (combination of fatty acids) precursor containing hydrocarbon with less amount of oxygen is used first time for synthesis of different carbon nanostructures (i.e., agglomerated carbon nanoparticles, carbon nanobeads and carbon tubular structure). The agglomerated carbon nanoparticles, carbon nanobeads and carbon tubular structure were synthesized by applying CVD method at different temperature using castor oil as new carbon precursor without any catalyst. The synthesis of carbon nanostructure is free from additional catalyst as this hydrocarbon (castor oil) is cheap with abundant sources of carbon. The effect of pyrolysis temperatures on the size, quality and quantity of the synthesized carbon shape were investigated. Interestingly, the morphology of the carbon nanostructures can be controlled in shape from agglomerated carbon nanoparticle to nanobeads to carbon tubular structure just by increasing the temperature from 750°C to 800°C to 850°C, respectively. These nanobeads are chains of uniform size of graphitized carbon spheres. These chains comprised individual carbon particles size of ~ 450 nm. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR).
Polysilane/Acenaphthylene Blends Toward Si–O–C Composite Anodes for Rechargeable Lithium-Ion Batteries
Authors: Fukui Hiroshi , Ohsuka Hisashi , Hino Takakazu , Kanamura Kiyoshi
Published: March 2011

Silicon oxycarbide (Si–O–C) composite materials have been prepared by pyrolysis of polysilane–acenaphthylene powdery blends to 1000°C under an inert gas atmosphere. Two branched polysilanes, (Ph2Si)0.85(PhSi)0.15 and (MePhSi)0.70(Ph2Si)0.15(MeSi)0.15, were used in this study. Our thermal analyses confirm a high possibility that acenaphthylene significantly affects the microstructure of the Si–O–C composite materials that can be represented as SiC
x
O2(1–x) + yC (free carbon). The powdery blends in a weight ratio of 1:1 produced the Si–O–C composite materials with a high lithium storage capacity (ca. 500 mA h g−1 or higher) and excellent cyclability. These composite materials clearly showed a pseudo-voltage plateau upon electrochemical delithiation, as seen in the case of hard carbon. 7Li NMR analyses showed the presence of at least two electrochemically active sites for lithium storage in the Si–O–C composite materials. Structural and electrochemical analyses support the idea that the Si–O–C composite materials have micropores where less-ionic lithium species can be formed. Increasing the ratio of acenaphthylene in the powdery blends resulted in low electrochemical performance because the free carbon contributed greatly to the microstructure of the resulting composite materials.
NHERF2 is necessary for basal activity, second messenger inhibition, and LPA stimulation of NHE3 in mouse distal ileum
Authors: Murtazina Rakhilya , Kovbasnjuk Olga , Chen Tian-E , Zachos Nicholas C. , Chen Yeuping , Kocinsky Hetal S. , Hogema Boris M. , Seidler Ursula , de Jonge Hugo R. , Donowitz Mark
Published: March 2011

To test the hypothesis that Na+/H+ exchanger (NHE) regulatory factor 2 (NHERF2) is necessary for multiple aspects of acute regulation of NHE3 in intact mouse small intestine, distal ileal NHE3 activity was determined using two-photon microscopy/SNARF-4F in a NHERF2-null mouse model. The NHERF2-null mouse ileum had shorter villi, deeper crypts, and decreased epithelial cell number. Basal rates of NHE3 activity were reduced in NHERF2-null mice, which was associated with a reduced percentage of NHE3 in the apical domain and an increase in intracellular NHE3 amount but no change in total level of NHE3 protein. cAMP, cGMP, and elevated Ca2+ due to apical exposure to UTP all inhibited NHE3 activity in wild-type mouse ileum but not in NHERF2-null mice, while inhibition by hyperosmolarity occurred normally. The cAMP-increased phosphorylation of NHE3 at aa 552; levels of PKAIIα and cGMP-dependent protein kinase II (cGKII); and elevation of Ca2+ were similar in wild-type and NHERF2-null mouse ileum. Luminal lysophosphatidic acid (LPA) stimulated NHE3 in wild-type but not in NHERF2-null ileum. In conclusion, 1) there are subtle structural abnormalities in the small intestine of NHERF2-null mouse which include fewer villus epithelial cells; 2) the decreased basal NHE3 activity and reduced brush border NHE3 amount in NHERF2-null mice show that NHERF2 is necessary for normal basal trafficking or retention of NHE3 in the apical domain; 3) hyperosmolar inhibition of NHE3 occurs similarly in wild-type and NHERF2-null ileum, demonstrating that some inhibitory mechanisms of NHE3 are not NHERF2 dependent; 4) cAMP inhibition of NHE3 is NHERF2 dependent at a step downstream of cAMP/PKAII phosphorylation of NHE3 at aa 552; 5) cGMP- and UTP-induced inhibition of NHE3 are NHERF2 dependent at steps beyond cGKII and the UTP-induced increase of intracellular Ca2+; and 6) LPA stimulation of NHE3 is also NHERF2 dependent.
Obligatory role of heat shock protein 90 in iNOS induction
Authors: Luo Suxin , Wang Tingting , Qin Honghua , Lei Han , Xia Yong
Published: March 2011

Inducible nitric oxide (NO) synthase (iNOS) plays an important role in cell injury and host defense. While undetectable in normal tissues, iNOS expression is induced by endotoxins and inflammatory cytokines primarily via the IκB kinase/nuclear factor-κB (IKK-NF-κB) and Janus kinase (JAK)-signal transducers and activators of transcription 1 (STAT1) pathways. Our previous studies found that heat shock protein 90 (Hsp90) associates with iNOS, and this association enhances iNOS activity. Here we show that Hsp90 is also essential for iNOS induction. With mouse macrophages, Hsp90 inhibition by geldanamycin or knockdown with small interfering RNA (siRNA) prevented lipopolysaccharide (LPS) or interferon-γ (IFN-γ)-stimulated iNOS protein expression. RT-PCR experiments showed that iNOS mRNA transcription was blocked by Hsp90 inhibition. Radicicol, another Hsp90 inhibitor whose structure is different from that of geldanamycin, also blocked iNOS mRNA transcription. These cell biology findings were confirmed in infarcted myocardium where iNOS expression was markedly attenuated by Hsp90 inhibition in vivo. Intriguingly, further analyses showed that inhibiting Hsp90 had no significant effect on the activation of either IKK-NF-κB or JAK-STAT1 in LPS/IFN-γ-stimulated cells. Neither was the nuclear transport of active NF-κB or STAT1 affected by Hsp90 inhibition. But Hsp90 inhibition markedly reduced the binding of active NF-κB and STAT1 to their DNA elements. Chromatin immunoprecipitation assays confirmed that Hsp90 was essential for NF-κB and STAT1 bindings to iNOS promoters inside cells. These studies reveal that besides acting as an allosteric enhancer, Hsp90 is also required for transcriptional factor binding amid iNOS mRNA transcription. In view of the essential role of Hsp90 in iNOS gene transactivation, targeting Hsp90 may represent a new approach to intervene iNOS expression in diseases.
Temporal expression profiles indicate a primary function for microRNA during the peak of DNA replication after rat partial hepatectomy
Authors: Raschzok Nathanael , Werner Wiebke , Sallmon Hannes , Billecke Nils , Dame Christof , Neuhaus Peter , Sauer Igor M.
Published: March 2011

The liver has the unique capacity to regenerate after surgical resection. However, the regulation of liver regeneration is not completely understood. Recent reports indicate an essential role for small noncoding microRNAs (miRNAs) in the regulation of hepatic development, carcinogenesis, and early regeneration. We hypothesized that miRNAs are critically involved in all phases of liver regeneration after partial hepatectomy. We performed miRNA microarray analyses after 70% partial hepatectomy in rats under isoflurane anesthesia at different time points (0 h to 5 days) and after sham laparotomy. Putative targets of differentially expressed miRNAs were determined using a bioinformatic approach. Two-dimensional (2D)-PAGE proteomic analyses and protein identification were performed on specimens at 0 and 24 h after resection. The temporal dynamics of liver regeneration were characterized by 5-bromo- 2-deoxyuridine, proliferating cell nuclear antigen, IL-6, and hepatocyte growth factor. We demonstrate that miRNA expression patterns changed during liver regeneration and that these changes were most evident during the peak of DNA replication at 24 h after resection. Expression of 13 miRNAs was significantly reduced 12–48 h after resection (>25% change), out of which downreguation was confirmed in isolated hepatocytes for 6 miRNAs at 24 h, whereas three miRNAs were significantly upregulated. Proteomic analysis revealed 65 upregulated proteins; among them, 23 represent putative targets of the differentially expressed miRNAs. We provide a temporal miRNA expression and proteomic dataset of the regenerating rat liver, which indicates a primary function for miRNA during the peak of DNA replication. These data will assist further functional studies on the role of miRNAs during liver regeneration.
Intragastric administration of allyl isothiocyanate increases carbohydrate oxidation via TRPV1 but not TRPA1 in mice
Authors: Mori Noriyuki , Kawabata Fuminori , Matsumura Shigenobu , Hosokawa Hiroshi , Kobayashi Shigeo , Inoue Kazuo , Fushiki Tohru
Published: March 2011

The transient receptor potential (TRP) channel family is composed of a wide variety of cation-permeable channels activated polymodally by various stimuli and is implicated in a variety of cellular functions. Recent investigations have revealed that activation of TRP channels is involved not only in nociception and thermosensation but also in thermoregulation and energy metabolism. We investigated the effect of intragastric administration of TRP channel agonists on changes in energy substrate utilization of mice. Intragastric administration of allyl isothiocyanate (AITC; a typical TRPA1 agonist) markedly increased carbohydrate oxidation but did not affect oxygen consumption. To examine whether TRP channels mediate this increase in carbohydrate oxidation, we used TRPA1 and TRPV1 knockout (KO) mice. Intragastric administration of AITC increased carbohydrate oxidation in TRPA1 KO mice but not in TRPV1 KO mice. Furthermore, AITC dose-dependently increased intracellular calcium ion concentration in cells expressing TRPV1. These findings suggest that AITC might activate TRPV1 and that AITC increased carbohydrate oxidation via TRPV1.
Avian renal proximal tubule urate secretion is inhibited by cellular stress-induced AMP-activated protein kinase
Authors: Bataille Amy M. , Maffeo Carla L. , Renfro J. Larry
Published: March 2011

Urate is a potent antioxidant at high concentrations but it has also been associated with a wide variety of health risks. Plasma urate concentration is determined by ingestion, production, and urinary excretion; however, factors that regulate urate excretion remain uncertain. The objective of this study was to determine whether cellular stress, which has been shown to affect other renal transport properties, modulates urate secretion in the avian renal proximal tubule. Chick kidney proximal tubule epithelial cell primary culture monolayers were used to study the transepithelial transport of radiolabeled urate. This model allowed examination of the processes, such as multidrug resistance protein 4 (Mrp4, Abcc4), which subserve urate secretion in a functional, intact, homologous system. Our results show that the recently implicated urate efflux transporter, breast cancer resistance protein ( ABCG2), does not significantly contribute to urate secretion in this system. Exposure to a high concentration of zinc for 6 h induced a cellular stress response and a striking decrease in transepithelial urate secretion. Acute exposure to zinc had no effect on transepithelial urate secretion or isolated membrane vesicle urate transport, suggesting involvement of a cellular stress adaptation. Activation of AMP-activated protein kinase (AMPK), a candidate modulator of ATP-dependent urate efflux, by 5′-aminoimidazole-4-carboxamide 1-β-d-ribo-furanoside caused a decrease in urate secretion similar to that seen with zinc-induced cellular stress. This effect was prevented with the AMPK inhibitor compound C. Notably, the decrease in urate secretion seen with zinc-induced cellular stress was also prevented by compound C, implicating AMPK in regulation of renal uric acid excretion.
Effects of exercise on endothelium and endothelium/smooth muscle cross talk: role of exercise-induced hemodynamics
Authors: Newcomer S. C. , Thijssen Dick H. J. , Green D. J.
Published: March 2011

Physical activity, exercise training, and fitness are associated with decreased cardiovascular risk. In the context that a risk factor “gap” exists in the explanation for the beneficial effects of exercise on cardiovascular disease, it has recently been proposed that exercise generates hemodynamic stimuli which exert direct effects on the vasculature that are antiatherogenic. In this review we briefly introduce some of the in vitro and in vivo evidence relating exercise hemodynamic modulation and vascular adaptation. In vitro data clearly demonstrate the importance of shear stress as a potential mechanism underlying vascular adaptations associated with exercise. Supporting this is in vivo human data demonstrating that exercise-mediated shear stress induces localized impacts on arterial function and diameter. Emerging evidence suggests that exercise-related changes in hemodynamic stimuli other than shear stress may also be associated with arterial remodeling. Taken together, in vitro and in vivo data strongly imply that hemodynamic influences combine to orchestrate a response to exercise and training that regulates wall stress and peripheral vascular resistance and contributes to the antiatherogenic impacts of physical activity, fitness, and training.
Reactive oxygen species (ROS) from NADPH and xanthine oxidase modulate the cutaneous local heating response in healthy humans
Authors: Medow Marvin S. , Bamji Natasha , Clarke Debbie , Ocon Anthony J. , Stewart Julian M.
Published: March 2011

Local cutaneous heating produces vasodilation that is largely nitric oxide (NO) dependent. We showed that angiotensin II (ANG II) attenuates this by an ANG II receptor, type 1 (AT1R)-dependent mechanism that is reversible with the antioxidant ascorbate, indicating oxidative stress. Reactive oxygen species (ROS) produced by ANG II employ NADPH and xanthine oxidase pathways. To determine whether these mechanisms pertain to skin, we measured cutaneous local heating with 10 μM ANG II, using apocynin to inhibit NADPH oxidase and allopurinol to inhibit xanthine oxidase. We also inhibited superoxide with tempol, and H2O2 with ebselen. We heated the skin of the calf in 8 healthy volunteers (24.5–29.9 yr old) to 42°C and measured local blood flow to assess the percentage of maximum cutaneous vascular conductance. We remeasured while perfusing allopurinol, apocynin, ebselen, and tempol through individual microdialysis catheters. This was then repeated with ANG II combined with antioxidant drugs. tempol and apocynin alone had no effect on the heat response. Allopurinol enhanced the entire response (125% of heat alone), while ebselen suppressed the heat plateau (76% of heat alone). ANG II alone caused significant attenuation of the entire heat response (52%). When added to ANG II, Allopurinol partially reversed the ANG II attenuation. Heat with ebselen and ANG II were similar to heat and ANG II; ebselen only partially reversed the ANG II attenuation. Apocynin and tempol each partially reversed the attenuation caused by ANG II. This suggests that ROS, produced by ANG II via NADPH and xanthine oxidase pathways, modulates the response of skin to the application of heat, and thus contributes to the control of local cutaneous blood flow.
Riluzole decreases flexion withdrawal reflex but not voluntary ankle torque in human chronic spinal cord injury
Authors: Theiss Renée D. , Hornby T. George , Rymer W. Zev , Schmit Brian D.
Published: March 2011

The objectives of this study were to probe the contribution of spinal neuron persistent sodium conductances to reflex hyperexcitability in human chronic spinal cord injury. The intrinsic excitability of spinal neurons provides a novel target for medical intervention. Studies in animal models have shown that persistent inward currents, such as persistent sodium currents, profoundly influence neuronal excitability, and recovery of persistent inward currents in spinal neurons of animals with spinal cord injury routinely coincides with the appearance of spastic reflexes. Pharmacologically, this neuronal excitability can be decreased by agents that reduce persistent inward currents, such as the selective persistent sodium current inhibitor riluzole. We were able to recruit seven subjects with chronic incomplete spinal cord injury who were not concurrently taking antispasticity medications into the study. Reflex responses (flexion withdrawal and H-reflexes) and volitional strength (isometric maximum voluntary contractions) were tested at the ankle before and after placebo-controlled, double-blinded oral administration of riluzole (50 mg). Riluzole significantly decreased the peak ankle dorsiflexion torque component of the flexion withdrawal reflex. Peak maximum voluntary torque in both dorsiflexion and plantarflexion directions was not significantly changed. Average dorsiflexion torque sustained during the 5-s isometric maximum voluntary contraction, however, increased significantly. There was no effect, however, on the monosynaptic plantar and dorsiflexor H-reflex responses. Overall, these results demonstrate a contribution of persistent sodium conductances to polysynaptic reflex excitability in human chronic spinal cord injury without a significant role in maximum strength production. These results suggest that intrinsic spinal cellular excitability could be a target for managing chronic spinal cord injury hyperreflexia impairments without causing a significant loss in volitional strength.
Does Cytomegalovirus Develop Resistance following Antiviral Prophylaxis and Treatment in Renal Transplant Patients in Kuwait?
Authors: Madi Nada , Al-Nakib Widad , Pacsa Alexander
Published: March 2011

The resistance of cytomegalovirus (CMV) to ganciclovir or valganciclovir is a factor in therapeutic failure and disease progression. CMV strains resistant to ganciclovir or valganciclovir have been associated with specific mutations in the UL97 and UL54 genes. Sequencing of both CMV UL97 and UL54 genes was performed to detect the presence of CMV antiviral resistance in six patients who received ganciclovir (and/or valganciclovir) and had prolonged detectable CMV DNA in their blood during antiviral treatment. Sequencing results showed no specific mutations in either UL97 or UL54 gene of CMV and therefore the CMV strains in kidney transplant patients who received ganciclovir either prophylactically or therapeutically were from the wild type. Our results suggest that CMV management and immunosuppression protocols for kidney transplant patients followed in the Organ Transplant Centre, Kuwait, is very effective in reducing the opportunity of developing CMV antiviral resistance.
Utilizing Implicit User Feedback to Improve Interactive Video Retrieval
Authors: Vrochidis Stefanos , Kompatsiaris Ioannis , Patras Ioannis
Published: March 2011

This paper describes an approach to exploit the implicit user feedback gathered during interactive video retrieval tasks. We propose a framework, where the video is first indexed according to temporal, textual, and visual features and then implicit user feedback analysis is realized using a graph-based methodology. The generated graph encodes the semantic relations between video segments based on past user interaction and is subsequently used to generate recommendations. Moreover, we combine the visual features and implicit feedback information by training a support vector machine classifier with examples generated from the aforementioned graph in order to optimize the query by visual example search. The proposed framework is evaluated by conducting real-user experiments. The results demonstrate that significant improvement in terms of precision and recall is reported after the exploitation of implicit user feedback, while an improved ranking is presented in most of the evaluated queries by visual example.
Cloning and Expression of Highly Pathogenic Avian Influenza Virus Full‐Length Nonstructural Gene in Pichia pastoris
Authors: Abubakar M. B. , Aini I. , Omar A. R. , Hair-Bejo M.
Published: March 2011

Avian influenza (AI) is a highly contagious and rapidly evolving pathogen of major concern to the poultry industry and human health. Rapid and accurate detection of avian influenza virus is a necessary tool for control of outbreaks and surveillance. The AI virus A/Chicken/Malaysia/5858/2004 (H5N1) was used as a template to produce DNA clones of the full‐length NS1 genes via reverse transcriptase synthesis of cDNA by PCR amplification of the NS1 region. Products were cloned into pCR2.0 TOPO TA plasmid and subsequently subcloned into pPICZαA vector to construct a recombinant plasmid. Recombinant plasmid designated as pPICZαA‐NS1 gene was confirmed by PCR colony screening, restriction enzyme digestion, and nucleotide sequence analysis. The recombinant plasmid was transformed into Pichia pastoris GS115 strain by electroporation, and expressed protein was identified by SDS‐PAGE and western blotting. A recombinant protein of approximately ~28 kDa was produced. The expressed protein was able to bind a rabbit polyclonal antibody of nonstructural protein (NS1) avian influenza virus H5N1. The result of the western blotting and solid‐phase ELISA assay using H5N1 antibody indicated that the recombinant protein produced retained its antigenicity. This further indicates that Pichia pastoris could be an efficient expression system for a avian influenza virus nonstructural (NS1).
Laboratory and Field Testing of an Automated Atmospheric Particle-Bound Reactive Oxygen Species Sampling-Analysis System
Authors: Wang Yungang , Hopke Philip K. , Sun Liping , Chalupa David C. , Utell Mark J.
Published: March 2011

In this study, various laboratory and field tests were performed to develop an effective automated particle-bound ROS sampling-analysis system. The system uses 2′7′-dichlorofluorescin (DCFH) fluorescence method as a nonspecific, general indicator of the particle-bound ROS. A sharp-cut cyclone and a particle-into-liquid sampler (PILS) were used to collect PM2.5atmospheric particles into slurry produced by a DCFH-HRP solution. The laboratory results show that the DCFH and H2O2standard solutions could be kept at room temperature for at least three and eight days, respectively. The field test in Rochester, NY, shows that the average ROS concentration was8.3±2.2nmol of equivalent H2O2 m−3of air. The ROS concentrations were observed to be greater after foggy conditions. This study demonstrates the first practical automated sampling-analysis system to measure this ambient particle component.
Surgical Management of Temporomandibular Joint Ankylosis in Ankylosing Spondylitis
Authors: Felstead Andrew M. , Revington Peter J.
Published: March 2011

Relatively few patients develop such severe degenerative temporomandibular joint (TMJ) disease that they require total joint replacement. Current indications include those conditions involving condylar bone loss such as degenerative (osteoarthritis) or inflammatory joint disease (ankylosing spondylitis, rheumatoid, and psoriatic). Ankylosis of the temporomandibular joint (TMJ) secondary to ankylosing spondylitis remains an under investigated entity. We aim to provide an overview of treatment objectives, surgical procedures, and our experience with total TMJ replacement for this condition.
Hybrid Algorithms of Common Solutions of Generalized Mixed Equilibrium Problems and the Common Variational Inequality Problems with Applications
Authors: Jitpeera Thanyarat , Witthayarat Uamporn , Kumam Poom
Published: March 2011

We introduce new iterative algorithms by hybrid method for finding a common element of the set of solutions of fixed points of infinite family of nonexpansive mappings, the set of common solutions of generalized mixed equilibrium problems, and the set of common solutions of the variational inequality with inverse-strongly monotone mappings in a real Hilbert space. We prove the strong convergence of the proposed iterative method under some suitable conditions. Finally, we apply our results to complementarity problems and optimization problems. Our results improve and extend the results announced by many others.