bluuebunny/crossref_metadata_2025 huggingface dataset:
Pure exchange markets for resource sharing in federated clouds
Authors: Gomes Eduardo R. , Vo Quoc Bao , Kowalczyk Ryszard
Published: November 2010

Cloud Computing is the latest paradigm proposed toward fulfilling the vision of computing being delivered as an utility such as phone, electricity, gas and water services. It enables users to have access to computing infrastructure, platform and software as services over the Internet. The services can be accessed on demand and from anywhere in the world in a quick and flexible manner, and charged for based on their usage, making the rapid and often unpredictable expansion demanded by nowadays' business environment affordable also for small spin‐off and start‐up companies. In order to be competitive, however, Cloud providers need to be able to adapt to the dynamic loads from users, not only optimizing the local usage and costs but also engaging into agreements with other Clouds so as to complement local capacity. The infrastructure in which competing Clouds are able to cooperate to maximize their benefits is called a Federated Cloud. Just as Clouds enable users to cope with unexpected demand loads, a Federated Cloud will enable individual Clouds to cope with unforeseen variations of demand. The definition of the mechanism to ensure mutual benefits for the individual Clouds composing the federation, however, is one of its main challenges. This paper proposes and investigates the application of market‐oriented mechanisms based on the General Equilibrium Theory of Microeconomics to coordinate the sharing of resources between the Clouds in the Federated Cloud. Copyright © 2010 John Wiley & Sons, Ltd.
A decentralized coordination method for optimal load redistribution in heterogeneous service grids
Authors: Chen Ying‐Ying , Wu Tie‐Jun
Published: November 2010

The optimal load redistribution problem is solved in this paper for heterogeneous non‐dedicated service grids in a decentralized way. A coordination policy is proposed to make networked servers reach their optimal generic task acceptance rates in order to minimize the average service time of all the generic tasks in a grid. Autonomous servers networked in the grid only need to coordinate with their neighbors iteratively, and their optimal generic acceptance rates are reached by task migration among them. The design scheme of the policy is introduced, and the convergence properties and the implementation aspects of the coordination system are discussed in detail in this paper. A set of computer simulations have been conducted, validating the effectiveness of the proposed approach. Copyright © 2010 John Wiley & Sons, Ltd.
Utility functions for adaptively executing concurrent workflows
Authors: Lee Kevin , Paton Norman W. , Sakellariou Rizos , Fernandes Alvaro A. A.
Published: November 2010

Workflows are widely used in applications that require coordinated use of computational resources. Workflow definition languages typically abstract over some aspects of the way in which a workflow is to be executed, such as the level of parallelism to be used or the physical resources to be deployed. As a result, a workflow management system has the responsibility of establishing how best to map tasks within a workflow to the available resources. As workflows are typically run over shared resources, and thus face unpredictable and changing resource capabilities, there may be benefit to be derived from adapting the task‐to‐resource mapping while a workflow is executing. This paper describes the use of utility functions to express the relative merits of alternative mappings; in essence, a utility function can be used to give a score to a candidate mapping, and the exploration of alternative mappings can be cast as an optimization problem. In this approach, changing the utility function allows adaptations to be carried out with a view to meeting different objectives. The contributions of this paper include: (i) a description of how adaptive workflow execution can be expressed as an optimization problem where the objective of the adaptation is to maximize a utility function; (ii) a description of how the approach has been applied to support adaptive workflow execution in execution environments consisting of multiple resources, such as grids or clouds, in which adaptations are coordinated across multiple workflows; and (iii) an experimental evaluation of the approach with utility measures based on response time and profit using the Pegasus workflow system. Copyright © 2010 John Wiley & Sons, Ltd.
Photoreduction of Water by using Modified CuInS2 Electrodes
Authors: Ikeda Shigeru , Nakamura Takayuki , Lee Sun Min , Yagi Tetsuro , Harada Takashi , Minegishi Tsutomu , Matsumura Michio
Published: November 2010

Polycrystalline CuInS2 films were fabricated by sulfurization of electrodeposited Cu and In metallic precursor films. Structural analyses revealed that the CuInS2 film formed compact agglomerates of crystallites with grain sizes of ca. 0.5–1.5 μm. Photoelectrochemical characterization revealed that the film was p‐type with a flat band potential of 0.3–0.4 V (vs Ag/AgCl at pH 4), which is suitable for water reduction but cannot be for water oxidation. Upon loading Pt deposits, the film worked as a hydrogen (H2) liberation electrode under cathodic polarization. Moreover, by introduction of n‐type thin layers such as CdS and ZnS on the CuInS2 surface before the Pt loading, appreciable improvements of H2 liberation efficiency were achieved: for the CdS modified sample, spectral response data showed incident photon to current efficiency as high as 20 % at wavelengths ranging from ca. 500 to 750 nm. Appreciable H2 evolution on this sample under potentials of power‐producing regions was also confirmed.
IC‐constrained optimization of continuous‐time Gm–C filters
Authors: Fernández‐Bootello Juan F. , Delgado‐Restituto Manuel , Rodríguez‐Vázquez Ángel
Published: November 2010

This paper presents an automated synthesis procedure for integrated continuous‐time fully‐differential Gm−C filters. Such procedure builds up on a general extended state‐space system representation which provides simple matrix algebra mechanisms to evaluate the noise and distortion performances of filters, as well as, the effect of amplitude and impedance scaling operations. The proposed technique not only addresses the dynamic range optimization under power dissipation constraints, but also accounts for other relevant integrated circuit related features, such as transconductor decomposition in unitary instances, spread of capacitances and estimated area occupation, among other characteristics. The proposed approach, implemented in the MATLAB® framework, can be also used as an exploratory tool to compare different circuit implementations for a given set of filter specifications. Copyright © 2010 John Wiley & Sons, Ltd.
Analytical synthesis and comparison of voltage‐modeNth‐order OTA‐C universal filter structures
Authors: Chang Chun‐Ming , Swamy M. N. S.
Published: November 2010

Complementary single‐ended‐input operational transconductance amplifier (OTA)‐based filter structures are introduced in this paper. Through two analytical synthesis methods and two transformations, one of which is to convert a differential‐input OTA to two complementary single‐ended‐input OTAs, and the other to convert a single‐ended‐input OTA and grounded capacitor‐based one to a fully differential OTA‐based one, four distinct kinds of voltage‐modenth‐order OTA‐C universal filter structures are proposed. TSMC H‐Spice simulations with 0.35µm process validate that the new complementary single‐ended‐input OTA‐based one holds the superiority in output precision, dynamic and linear ranges than other kinds of filter structures. Moreover, the new voltage‐mode band‐pass, band‐reject and all‐pass (except the fully differential one) biquad structures, all enjoy very low sensitivities. Both direct sixth‐order universal filter structures and their equivalent three biquad stage ones are also simulated and validated that the former is not absolutely larger in sensitivity than the latter. Finally, a very sharp increment of the transconductance of an OTA is discovered as the operating frequency is very high and leads to a modified frequency‐dependent transconductance. Copyright © 2010 John Wiley & Sons, Ltd.
Companding schemes based on transforming signal statistics into trigonal distributions for PAPR reduction in OFDM systems
Authors: Wu Xinchun , Wang Jinxiang , Zhou Bin , Mao Zhigang , Gao Zhiqiang
Published: November 2010

This paper proposes four companding transforms to reduce the peak‐to‐average power ratio in orthogonal frequency division multiplexing systems. The four companding transforms are obtained by transforming signal statistics into four trigonal distributions. Computer simulations show that the proposed schemes can effectively improve the PAPR performance and bit error rate performance of OFDM systems. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of SER of MIMO‐MRC systems with imperfect channel estimation in the presence of non‐Rayleigh CCIs
Authors: Zhang Wei‐jiong , Guan Zhang‐jun , Zhou Xi‐lang
Published: November 2010

In this paper, we study the average symbol error rate (SER) for a multiple input multiple output (MIMO) maximal ratio combining (MRC) system with Rayleigh fading desired signal in the presence of non‐Rayleigh fading co‐channel interferers (CCIs) and additive white Gaussian noise (AWGN). To simulate the actual environments of wireless transmission, we assume that the transceiver only obtains imperfect channel estimation (ICE). For the cases of Nakagami and Rician fading CCIs, analytic expressions for the SER have been derived approximately by introducing the modified signal‐to‐interference and noise power ratio (SINR) that can be obtained by averaging the CCI term in the original SINR over the distribution of ICE of intended user. These formulas can provide important reference of design of MIMO diversity systems. Numerical simulations verify the effectiveness of these formulas. Copyright © 2010 John Wiley & Sons, Ltd.
Transmission control in multilateral system for teletraining
Authors: Katsura Seiichiro , Suzuyama Toshiyuki , Ohishi Kiyoshi
Published: November 2010

Recently, preservation of the skills of experts has become a serious problem in the medical and production fields. It is difficult to acquire human motion, including touching motion, by means of a conventional visual‐based system. Touching motion is inherently bilateral, since an action is always accompanied by a reaction. Bilateral force feedback control is necessary to acquire another person's skill. This paper proposes a haptic teletraining system using multilateral force feedback control. Since the multilateral control transmits haptic information among three or more remote systems, it is possible to train multiple remote trainees simultaneously using one skilled trainer. In the proposed haptic teletraining system, each local system consists of a master‐slave system. Since a touching motion is subject to the law of action and reaction, it is possible to decompose the force information into an action force and a reaction force by using bilateral control. Thus, the skilled motion of a trainer is acquired and saved as a digital database integrated with his haptic information. The proposed system is applied to a one‐trainer/two‐trainee system. As a result, motion including contact with the environment is transmitted and trained with vivid force feedback. The experimental results show the viability of the proposed method. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(12): 26–34, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10237
Low‐Nuclearity MnII Complexes Based on Pyrimidine‐4,6‐dicarboxylato Bridging Ligand: Crystal Structure, Ion Exchange and Magnetic Properties
Authors: Beobide Garikoitz , Castillo Oscar , Cepeda Javier , Luque Antonio , Pérez‐Yáñez Sonia , Román Pascual , Vallejo‐Sánchez Daniel
Published: November 2010

The use of 1,10‐phenanthroline (phen) has allowed the polymerisation process commonly occurring in manganese(II)/pyrimidine‐4,6‐dicarboxylate (pmdc) systems to be blocked off giving the first examples of low‐nuclearity coordination compounds containing the pmdc dianion, namely, the dimeric [Mn2(μ‐pmdc)2(H2O)2(phen)2]·8H2O compound (1) and the tetrameric [Mn4(μ‐pmdc)3(phen)4(H2O)4](X)2·11H2O[X = BF4– (2), ClO4– (3), NO3– (4)] complexes. X‐ray analyses show that the hexacoordinate MnII atoms are bridged by pmdc dianions that exhibit an asymmetric κ2N,O:κO′ coordination mode in compound 1 and adopt a bis‐bidentate κ2N,O:κ2N′,O′ binding pattern in the tetrameric units of compounds 2–4. The distorted octahedral O3N3 donor set of the metal centres in 1 is completed by two nitrogen atoms from a phenanthroline ligand and one water molecule. In the linear zigzag shaped tetrameric cations of compounds 2–4, the two inner manganese centres with a O2N4 donor set are, in addition, coordinated to two nitrogen atoms from a phenanthroline ligand, whereas the outer ones complete their O3N3 coordination environment with a bidentated phenanthroline ligand and two cis coordinated water molecules. The crystal packing of the complex units generates voids filled by hydrogen‐bonded C3‐like water chains in compound 1, whereas compounds 2–4 resemble a 3D open‐framework in which the channels are occupied by the counterions and the water molecules of crystallisation. Ion exchange tests were carried out showing that compound 4 exhibits a high capacity to capture other inorganic anions by releasing nitrates. Cryomagnetic susceptibility measurements have shown the occurrence of weak antiferromagnetic interactions (J = –0.06, –0.21, –0.26 and –0.25 cm–1 for compounds 1–4, respectively). The magneto‐structural analysis indicates that the magnetic interaction taking place through the μ‐pyrimidine ring, although being weak, predominates over the longer exchange pathway involving the two carboxylate groups of the pmdc ligand.
Chemistry of Group IV Metal Ion‐Containing Polyoxometalates
Authors: Nomiya Kenji , Sakai Yoshitaka , Matsunaga Satoshi
Published: November 2010

The chemistry of Group IV metal ion (TiIV, ZrIV and HfIV)‐containing polyoxometalates (POMs) is presented as a sharply focused microreview, introducing an aspect of our own research. The synthesis, structure, and solid/solution state behavior of the POMs, which are prepared by the reactions of various lacunary species of POMs with TiIV, ZrIV and HfIV atoms, are described in several sections, classified with Keggin and Dawson POM families. Because of the ionic radius of TiIV (0.75 Å), close to that of WVI (0.74 Å), the TiIV atom can fit nicely into the mono‐lacunary site of the POM, but ZrIV and HfIV atoms (0.85–0.86 Å), larger than TiIV atom, do not fit into the mono‐lacunary site of the POM. Thus, the mono‐lacunary site of the POM acts as the oxygen‐donor pentadentate ligand to the TiIV atom, whereas it acts as the tetradentate ligand to ZrIV and HfIV atoms. The TiIV atom in the POM takes on six‐coordinate geometry, whereas the ZrIV and HfIV atoms have higher coordination numbers (6, 7 and 8) due to their larger ionic radii. Consequently, most Ti‐substituted Keggin POMs are isolated as oligomers formed by corner‐sharing Ti–O–Ti bonds, whereas Zr/Hf‐containing Keggin/Dawson POMs are usually isolated as di‐, tri‐, tetra‐Zr/Hf cluster cations sandwiched between two lacunary POMs, the cluster cations of which are formed by edge‐sharing M(OH)2M (M = Zr, Hf) bonds. These compounds show quite different behavior under pH‐dependent conditions. The pH‐dependent interconversion between the dimeric and monomeric species of Ti‐substituted Dawson POMs is quite an opposite tendency from those of Zr/Hf‐containing Dawson POMs. The Ti‐substituted Dawson POM oligomers have a tendency to undergo base hydrolysis to give monomers, whereas the Zr/Hf‐containing Dawson POM oligomers have a tendency to undergo acid hydrolysis to provide monomers. In the Group IV metal ion‐containing POMs, the Zr/Hf atoms function very similarly to each other, but show quite different behavior from the Ti atom.
Development of a Novel Electrochemical Biosensor for Detection and Discrimination of DNA Sequence and Single Base Mutation in dsDNA Samples Based on PNA‐dsDNA Hybridization – a new Platform Technology
Authors: Hejazi Mohammad Saeid , Pournaghi‐Azar Mohammad Hossein , Alipour Esmaeel , Abdolahinia Elaheh Dalir , Arami Sanam , Navvah Hosnieh
Published: November 2010

In spite of the extensive attention paid on the development of various DNA detection strategies, very few studies have been reported regarding direct detection of DNA sequence and mutation in dsDNA. Here, we describe the feasibility of detection and discrimination of target DNA sequences and single base mutations (SBM) directly in double‐stranded oligonucleotides and PCR products without the need for denaturation of the target dsDNA samples. This goal was achieved by employing a peptide nucleic acid (PNA) chain, self‐assembled on the gold electrode as a probe, which binds to dsDNA and forms PNA‐dsDNA hybrid.
Effect of nanofillers on the flame retardant properties of a polyethylene–calcium carbonate–silicone elastomer system
Authors: Karlsson Linus , Lundgren Anna , Jungqvist Jonas , Hjertberg Thomas
Published: November 2010

This study shows the effects of three different nanofillers on the viscosity properties and fire behavior of a halogen‐free flame retardant system. The original system, based on ethylene‐acrylate copolymer, calcium carbonate, and a silicone elastomer, shows good flame retardant properties. One of the nanofillers, montmorillonite (MMT), significantly increases the viscosity above 250∘C, resulting in reduced dripping and decreased heat release rate. The ash residue, however, is very brittle, indicating poor interactions between the MMT and other components of the system. The second nanofiller, sepiolite, shows no improvement on the flame retardant properties of the system. Reduced dripping is observed when a small amount of the third nanofiller, polyhedral oligomeric silsesquioxane, POSS, is incorporated into the system. In this case, high silica content on the surface indicates char formation originating from the POSS. However, an increased heat release is observed when POSS is used in the system. Copyright © 2010 John Wiley & Sons, Ltd.
Legitimacy, trustee incentives, and board processes: the case of public and private non‐profit nursing homes
Authors: Dewaelheyns Nico , Eeckloo Kristof , Van Hulle Cynthia
Published: November 2010

Using a unique data set, this study explores how type of ownership (government/private) is related to processes of governance. The findings suggest that the neo‐institutional perspective and the self‐interest rationale of the agency perspective are helpful in explaining processes of governance in both government‐ and privately owned non‐profit organizations. Due to adverse incentives and the quest for legitimacy, supervising governance bodies within local government‐owned non‐profit institutions pay relatively less attention to the development of high quality supervising bodies and delegate little to management. Our findings also indicate that governance processes in private institutions are more aligned with the business model and that this alignment is likely driven by a concern to improve decision making. By contrast, our data also suggest that in local government‐owned institutions re‐election concerns of politicians–trustees are an important force in the governance processes of these institutions. In view of these adverse incentives – in contrast to the case of private organizations – a governance code is unlikely to entail much improvement in government‐owned organizations. Copyright © 2010 John Wiley & Sons, Ltd.
Sleep patterns of 7‐week‐old infants at familial risk for attention deficit hyperactivity disorder
Authors: Landau Rivka , Sadeh Avi , Vassoly Paz , Berger Andrea , Atzaba‐Poria Naama , Auerbach Judith G.
Published: November 2010

Sleep patterns of 26 seven‐week‐old boys at familial risk for attention deficit hyperactivity disorder (ADHD) and 18 control infants were compared by objective (actigraph) and subjective (maternal sleep diary) measures, over five consecutive 24‐hr periods. Actigraph findings indicated that the groups differed on stability (SD) of quiet sleep only during the day. Reports in maternal sleep diaries indicated that they also differed on stability of waking and stability of sleep duration, again only during the day. No group differences were found in terms of average scores, whether calculated for the entire 24‐hr periods, for nights, or for days. Mothers in the risk group reported that fathers were less involved in infant care than did those in the control group. These findings suggest that as early as 7 weeks of age, infants at risk for ADHD differ from controls only on stability of their sleep patterns during the day, when environmental regulatory factors are more intensive.
Integrin beta1 over‐expression associates with resistance to tyrosine kinase inhibitor gefitinib in non‐small cell lung cancer
Authors: Ju Lixia , Zhou Caicun , Li Wei , Yan Linghua
Published: November 2010

The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) such as gefitinib and erlotinib have been widely used in treating patients with advanced non‐small cell lung cancer (NSCLC). However, acquired resistance to EGFR TKI almost occurs in every patient eventually. To identify its potential mechanism, we established a human NSCLC cell line PC9/AB2 which was 576‐fold decrease in gefitinib sensitivity compared with its parental PC9 cell lines. No EGFR‐T790M mutation or abnormal expression of c‐Met protein was found in PC9/AB2 cells. Over‐expression of integrin β1 was found, accompanied with increase of the cells' adhesion and migration. To further confirm the role of integrin β1 in gefitinib acquired resistance, we transferred its siRNA‐expressing plasmid and its whole cDNA expressing plasmid into PC9/AB2 and into PC9 cells, respectively. The sensitivity of NSCLC cells to gefitinib was negatively correlated with integrin β1 expression levels. All these data suggest that up‐regulation of integrin β1 might be an important factor for gefitinib resistance in NSCLC cell line PC9/AB2. J. Cell. Biochem. 111: 1565–1574, 2010. © 2010 Wiley‐Liss, Inc.
C‐terminal domain of p16INK4a is adequate in inducing cell cycle arrest, growth inhibition and CDK4/6 interaction similar to the full length protein in HT‐1080 fibrosarcoma cells
Authors: Fahham Najmeh , Sardari Soroush , Ostad Seyed Nasser , Vaziri Behrouz , Ghahremani Mohammad Hossein
Published: November 2010

The tumor suppressor p16INK4a has earned widespread attention in cancer studies since its discovery as an inhibitor of cyclin‐dependent kinases (CDKs) 4/6. Structurally, it consists of four complete ankyrin repeats, believed to be involved in CDK4 interaction. According to the previous disparities concerning the importance of domains and inactivating mutations in p16, we aimed to search for the domain possessing the functional properties of the full length protein. Upon our in silico screening analyses followed by experimental assessments, we have identified the novel minimum functional domain of p16 to be the C‐terminal half including ankyrin repeats III, IV and the C‐terminal flanking region accompanied by loops 2 and 3. Transfection of this truncated form into HT‐1080 human fibrosarcoma cells, lacking endogenous p16, revealed that it is able to inhibit cell growth and proliferation equivalent to p16INK4a. The functional analysis showed that this fragment like p16 can interact with CDK4/6, block the entry into S phase of the cell cycle and suppress growth as indicated by colony formation assay. Identification of p16 minimum functional domain can be of benefit to the future peptidomimetic drug design as well as gene transfer for cancer therapy. J. Cell. Biochem. 111: 1598–1606, 2010. © 2010 Wiley‐Liss, Inc.
Role of Bim in diallyl trisulfide‐induced cytotoxicity in human cancer cells
Authors: Lee Byeong‐Chel , Park Bae‐Hang , Kim Seog‐Young , Lee Yong J.
Published: November 2010

The aim of this study was to investigate the effect of garlic constituent diallyl trisulfide (DATS) on the cell‐death signaling pathway in a human breast cell line (MDA‐MB‐231). We observed that DATS (10–100 µM) treatment resulted in dose‐ and time‐dependent cytotoxicity. Treatment of MDA‐MB‐231 cells with a cytotoxicity inducing concentration of DATS (50–80 µM) resulted in an increase in the intracellular level of reactive oxygen species (ROS). Data from assay with MitoSOXTM Red reagent suggest that mitochondria are the main source of ROS generation during DATS treatment. DATS‐induced oxidative stress was detected through glutaredoxin (GRX), a redox‐sensing molecule, and subsequently GRX was dissociated from apoptosis signal‐regulating kinase 1 (ASK1). Dissociation of GRX from ASK1 resulted in the activation of ASK1. ASK1 activated a downstream signal transduction JNK (c‐Jun N‐terminal kinase)‐Bim pathway. SP600125, a JNK inhibitor, inhibited DATS‐induced Bim phosphorylation and protected cells from DATS‐induced cytotoxicity. Our results indicate that the cytotoxicity caused by DATS is mediated by the generation of ROS and subsequent activation of the ASK1‐JNK‐Bim signal transduction pathway in human breast carcinoma MDA‐MB‐231 cells. J. Cell. Biochem. 112: 118–127, 2011. © 2010 Wiley‐Liss, Inc.
Activation of signal pathways and the resistance to anti‐EGFR treatment in colorectal cancer
Authors: Chen Jiezhong , Huang Xu‐Feng , Katsifis Andrew
Published: November 2010

Colorectal cancer is the third most common cancer with a 5‐year survival rate of less than 10%. It is caused by alterations of multiple signal pathways which are affected by both genetic and environmental factors. In some cases, EGFR is important in the carcinogenesis of colorectal cancer suggesting anti‐EGFR therapy may be a potential treatment option. However, in other cases it is not effective, which may be related to its down‐stream targeted gene mutations. KRAS is highly emphasized in the literature but other mutations like Src, PIK3CA, and BRAF may also be important. Furthermore, obesity may decrease the effectiveness of anti‐EGFR treatment as it increases the risk factors for colorectal cancer. Using next‐generation sequencing technology, it may be possible to identify all gene mutations in an individual with colorectal cancer. Therefore, gene mutations affecting anti‐EGFR therapy in colorectal cancer patients can be identified. J. Cell. Biochem. 111: 1082–1086, 2010. © 2010 Wiley‐Liss, Inc.
Anti‐inflammatory activity of Eugenia punicifolia extract on muscular lesion of mdx dystrophic mice
Authors: Leite Paulo Emílio Corrêa , de Almeida Kessiane Belshoff , Lagrota‐Candido Jussara , Trindade Pablo , da Silva Rafael Ferreira , Ribeiro Manuel Gustavo L. , Lima‐Araújo Katia G. , Santos Wilson C. , Quirico‐Santos Thereza
Published: November 2010

Eugenia punicifolia known as “pedra‐ume caá” is a shrub largely distributed in the Amazon region popularly used in decoctions or infusions as a natural therapeutic agent, which can interfere on cholinergic nicotinic neurotransmission. This work aimed to investigate a putative anti‐inflammatory effect of dichloromethane fraction of E. punicifolia extract (Ep‐CM) in the muscular lesion of mdx dystrophic mice, considering that activation of cholinergic mechanisms mitigates inflammation. A polymer containing the Ep‐CM was implanted in mdx gastrocnemius muscle before onset of myonecrosis for local slow and gradual release of bioactive compounds and mice sacrificed 7 days or 9 weeks after surgery. Comparing to control muscle, treatment did not alter choline acetyltransferase and acetylcholinesterase enzymatic activities, but decreased metaloproteases‐9 and ‐2 activities and levels of tumor necrosis factor α and NFκB transcription factor. In addition, treatment also reduced levels of bioactive IL‐1β form and cleaved caspase‐3, related to early events of cellular death and inflammatory activation and further increased myogenin expression without affecting collagen production which is associated with fibrosis. In vivo treatment of mdx dystrophic mice with Ep‐CM caused significant reduction of muscular inflammation and improved skeletal muscle regeneration without inducing fibrosis. J. Cell. Biochem. 111: 1652–1660, 2010. © 2010 Wiley‐Liss, Inc.
Identification of functional domains and novel binding partners of STIM proteins
Authors: Saitoh Norimitsu , Oritani Kenji , Saito Kazunobu , Yokota Takafumi , Ichii Michiko , Sudo Takao , Fujita Natsuko , Nakajima Koichi , Okada Masato , Kanakura Yuzuru
Published: November 2010

With a signal trap method, we previously identified stromal interaction molecule (STIM: originally named as SIM) as a protein, which has a signal peptide in 1996. However, recent works have accumulated evidences that STIM1 and STIM2 reside in endoplasmic reticulum (ER) and that both mainly sense ER Ca2+ depletion, which plays an essential role in store operated calcium entry. In the present study, we extensively analyzed the domain functions and associated molecules of STIMs. A STIM1 mutant lacking the coiled‐coil domains was massively expressed on the cell surface while mutants with the coiled‐coil domains localized in ER. In addition, STIM1 mutants with the coiled‐coil domains showed a longer half‐life of proteins than those without them. These results are likely to indicate that the coiled‐coil domains of STIM1 are essential for its ER‐retention and its stability. Furthermore, we tried to comprehensively identify STIM1‐associated molecules with mass spectrometry analysis of co‐immunoprecipitated proteins for STIM1. This screening clarified that both STIM1 and STIM2 have a capacity to bind to a chaperone, calnexin as well as two protein‐transporters, exportin1 and transportin1. Of importance, our result that glycosylation on STIM1 was not required for the association between STIM1 and calnexin seems to indicate that calnexin might function on STIM1 beyond a chaperone protein. Further information concerning regulatory mechanisms for STIM proteins including the data shown here will provide a model of Ca2+ control as well as a useful strategy to develop therapeutic drugs for intracellular Ca2+‐related diseases including inflammation and allergy. J. Cell. Biochem. 112: 147–156, 2011. © 2010 Wiley‐Liss, Inc.
Adsorption and dissociation of NH3 on clean and hydroxylated TiO2 rutile (110) surfaces: A computational study
Authors: Chang Jee‐Gong , Chen Hsin‐Tsung , Ju Shin‐Pon , Chang Ching‐Sheng , Weng Meng‐Hsiung
Published: November 2010

The adsorption and dissociation of NH3 on the clean and hydroxylated TiO2 rutile (110) surfaces have been investigated by the first‐principles calculations. The monodentate adsorbates such as H3NTi(a), H2NTi(a), NTi(a), H2NO(a), HNO(a), NO(a) and HO(a), as well as the bidentate adsorbate, TiNTi(a) can be formed on the clean surface. It is found that the hydroxyl group enhances the adsorption of certain adsorbates on the five‐fold‐coordinated Ti atoms (5c‐Ti), namely H2NTi(a), HNTi(a), NTi(a) and TiNTi(a). In addition, the adsorption energy increases as the number of hydroxyl groups increases. On the contrary, the opposite effect is found for those on the two‐fold‐coordinated O atoms (2c‐O). The enhanced adsorption of NHx (x = 1 − 2) on the 5c‐Ti is due to the large electronegativity of the OH group, increasing the acidity of the Ti center. This also contributes to diminish the adsorption of NHx (x = 1 − 2) on the two‐fold‐coordinated O atoms (2c‐O) decreasing its basicity. According to potential energy profile, the NH3 dissociation on the TiO2 surface is endothermic and the hydroxyl group is found to lower the energetics of H2NTi(a)+HO(a) and HNTi(a)+2{HO(a)}, but slightly raise the energetic of TiNTi(a)+3{HO(a)} compare to those on the clean surface. However, the dissociation of NH3 is found to occur on the hydroxylated surface with an overall endothermic by 31.8 kcal/mol and requires a barrier of 37.5 kcal/mol. A comparison of NH3 on anatase surface has been discussed. The detailed electronic analysis is also carried out to gain insights into the interaction nature between adsorbate and surface. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011.
Mechanism of methylacetylene bisselenation catalyzed by palladium complex from density functional study
Authors: Wang Meiyan , Cheng Lin , Wang Jinping , Wu Zhijian
Published: November 2010

The reaction mechanism of Pd(0)‐catalyzed methylacetylene bisselenation reaction is investigated by using the density functional method. The overall reaction mechanism involves the oxidative addition, insertion, and reductive elimination steps. The regioselectivity has been investigated for the methylacetylene insertion into PdSe bond of both cis and trans palladium complexes. It is found that the methylacetylene insertion into PdSe bond of the trans palladium complex using the substituted carbon atom attached to selenyl group is preferred among the four pathways of methylacetylene insertion processes. The electronic mechanisms on the methylacetylene insertion into PdSe bond are discussed in terms of the Frontier molecular orbital interactions. In addition, the influence of carbon monoxide on methylacetylene bisselenation was studied and found that the methylacetylene coordination and insertion into PdSe bond take place first generating the PdC bond, followed by CO insertion into the PdC bond. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010.
Raman spectroscopic study of the uranyl titanate mineral euxenite (Y,Ca,U,Ce,Th) (Nb,Ta,Ti)2O6
Authors: Frost Ray L. , Palmer Sara J. , Reddy B. Jagannadha
Published: November 2010

Raman spectra of the uranyl titanate mineral euxenite were analysed and related to the mineral structure. A comparison is made with the Raman spectra of uranyl oxyhydroxide hydrates. The observed bands are attributed to the TiO and (UO2)2+ stretching and bending vibrations, as well as lattice vibrations of rare‐earth ions. The Raman bands of euxenite are in harmony with those of the uranyl oxyhydroxides. The mineral euxenite is metamict as is evidenced by the intensity of the UO stretching and bending modes, which are of lower intensity than expected, and with bands that are significantly broader. Copyright © 2010 John Wiley & Sons, Ltd.
Surface‐enhanced Raman spectra of dimethoate and omethoate
Authors: Guerrini Luca , Sanchez‐Cortes Santiago , Cruz Victor L. , Martinez Sonia , Ristori Sandra , Feis Alessandro
Published: November 2010

Surface‐enhanced Raman scattering (SERS) spectra are presented and analyzed for two important organophosphate pesticides, dimethoate (DMT) and omethoate (OMT). Very detailed SERS spectra were obtained by aggregated Ag hydrosols, both in aqueous suspension and dried on a glass substrate. The SERS and ordinary Raman spectra of DMT do not resemble each other, suggesting that a chemical reaction immediately occurs when DMT is adsorbed onto the metal surface. We propose that the reaction product is OMT, which is the oxygen analog of DMT, on the basis of the Raman and SERS spectra of OMT. Further support is derived from the calculated Raman spectra of DMT and OMT. Minor wavenumber and intensity differences that are observed between the SERS spectra of DMT reaction product and those of OMT could be related to different metal/adsorbate interaction modes. The results can be useful in the development of new analytical methods for the determination of pesticide residues in food. Copyright © 2010 John Wiley & Sons, Ltd.
Soil‐vegetation relationships of three arid land plant species and their use in rehabilitating degraded sites
Authors: Chigani H. Kargar , Khajeddin S. J. , Karimzadeh H. R.
Published: November 2010

It is essential to consider soil characteristics when establishing vegetation in arid lands. In this study, the redundancy analysis (RDA) ordination method was used in this study to evaluate the habitats of Halocnemum strobilaceum, Limonium iranicum and Tamarix passerinoides growing in the Sejzy region, east of Isfahan. The study area was stratified into six ecologic‐floristic complexes. Stratified random sampling was then employed to collect soil and vegetation data from 1‐ha quadrats on nine sites. The soil samples were analysed to determine the characteristics of the soil in which the three species grew and to examine the soil profiles up to a depth of 2 m. Soil analyses revealed that high amounts of gypsum, silt, clay, saline, alkali and sulphate in the soil constituted a favourable habitat for Halocnemum strobilaceum. However, the per cent of silt and sulphate concentration in deep layers were negatively correlated with the growth of this species. Evaluation of the L. iranicum habitat revealed that the amounts of carbonate and CCE in the topsoil were positively correlated with the establishment and growth of the species but salinity and alkalinity were negatively correlated. The primary soil characteristics that positively influenced T. passerinoides included the presence of organic matter and bicarbonate ions in the soil layers and the total Ca and Mg content of the topsoil. However, Na was negatively correlated with Tamarix species. Determination of the soil characteristics that are associated with each of these xerophytic species can be used to determine which species is suitable for rehabilitating degraded sites in the study area. Copyright © 2010 John Wiley & Sons, Ltd.
An alternative approach to estimating parameters in creep models of high‐density polyethylene
Authors: Cheng Joy J. , Polak Maria Anna , Penlidis Alexander
Published: November 2010

Polyethylene (PE) is increasingly used in structural applications due to its light weight and rust‐resistant nature. With growing demand for the use of PE as a structural material, there is a need for mathematical models that describe the mechanical behavior of this material. Curve fitting using a linear time‐dependent model is a common approach for modeling creep of PE at the macrostructural level. However, besides the point estimates of the model parameters and the (visual) fit of the model to experimental data, little else is learnt from the curve‐fitting approach. This work presents a rigorous statistical approach for modeling creep compliance of PE. Four high‐density PE resins used over a wide range of applications are studied. Linear viscoelastic modeling using the multi‐Kelvin element theory is examined in two forms: model linear in parameters and model nonlinear in parameters. With the application of valid statistical techniques, complex relationships between model parameters, largely unstudied before, are observed, such as evidence of a high degree of correlation among material parameters of the creep model. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Photodegradation of plasticized poly(vinyl chloride) stabilized by different types of thermal stabilizers
Authors: Xiang Xiuqin , Chen Shuangjun , Zhang Jun , Chai Ruidan
Published: November 2010

Photodegradation of plasticized poly(vinyl chloride) (PVC) stabilized by different thermal stabilizers including organic calcium complex and mercaptide organotin was investigated. Plasticized PVC sheets prepared by an open twin‐roller mill and plate vulcanizing machine were exposed to xenon‐arc light with the irradiance of 0.51 W/(m2·nm) at 65°C. A much better color stability displayed by mercaptide organotin than organic calcium complex has been confirmed by digital photos and color difference. This can be explained that the more effective mercaptide organotin minimizes the amount of thermal damage from processing thus favours subsequent UV weathering. Carbonyl index and decomposition activation energy (Ea1) obtained from attenuated total refection‐Fourier transform infrared spectra (ATR‐FTIR) and thermogravimetric (TG) analysis, respectively, further indicate that plasticized PVC sheets containing mercaptide organotin have more excellent UV resistance. Mechanical tests reveal that photodegradation of PVC is accompanied by the predominant process of chain scission on the surface of samples. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
1/f noise in conducting channels of topological insulator materials
Authors: Hossain M. Zahid , Rumyantsev Sergey L. , Teweldebrhan Desalegne , Shahil Khan M. F. , Shur Michael , Balandin Alexander A.
Published: November 2010

We report results of investigation of the low‐frequency excess noise in device channels made from topological insulators – a new class of materials with a bulk insulating gap and conducting surface states. The thin‐film Bi2Se3 samples were prepared by the ‘graphene‐like’ mechanical exfoliation from bulk crystals. The fabricated four‐contact devices had linear current–voltage characteristics in the low‐bias regime |VSD| < 0.1 V. The current fluctuations had the noise spectral density SI ∼1/f for the frequency f < 10 kHz. The noise density SI followed the quadratic dependence on the drain–source current and changed from about ∼10−22 to 10−18 A2/Hz as the current increases from ∼10−7 to 10−5 A. The obtained data is important for planning transport experiments with topological insulators. We suggest that achieving the pure topological insulator phase with the current conduction through the ‘protected’ surface states can lead to noise reduction via suppression of certain scattering mechanisms. The latter has important implications for implementing the ultra‐low‐power and ultra‐low‐noise electronics.
Warping of triple line in the wetting of B4C by a Cu‐1 at.% Cr alloy
Authors: Lin Qiaoli , Shen Ping , Yang Longlong , Qiu Feng , Jiang Qichuan
Published: November 2010

The wetting of polycrystalline B4C by a molten Cu‐1 at.% Cr alloy was investigated at 1373 K using a modified sessile drop method. The triple line warped after the contact angle reached a certain degree. The mechanism for this unusual phenomenon was presumably ascribed to the large disparity in the wettability for the liquid on the CrB2 reaction layer and the precipitated graphite phase, as well as to their formation kinetics, rather than to the capillary flow driven by the surface tension gradient, as observed in the Cu/Si system. Copyright © 2010 John Wiley & Sons, Ltd.
Nonsimilar solutions of the viscous shallow water equations governing weak hydraulic jumps
Authors: Dasgupta Ratul , Govindarajan Rama
Published: November 2010

The steady viscous shallow water equations are often used for the study of hydraulic jumps. We cast these as a single parametric ordinary differential equation with global continuity as a constraint. The solution provides both the local velocity profile and the downstream evolution of the film height. Moreover this is an exact approach, in contrast with existing approaches which encounter a closure problem and need modeling. There is only one solution which is supercritical initially. This shows a jumplike behavior at a Froude number close to unity, in consonance with predictions of inviscid theory. At low Froude number, it is shown that two solutions are possible, one with a separated profile and one without. Flow downstream of a real hydraulic jump must switch to the second solution, calling into question the validity of the shallow water approach in resolving the region of the switch. A series solution of the velocity profile shows that the first correction to a streamwise-varying parabolic profile is a quartic term. Circular and planar solutions are qualitatively similar.
Superconducting transition width under magnetic field in MgB2 polycrystalline samples
Authors: Wang C. C. , Zeng R. , Xu X. , Dou S. X.
Published: November 2010

A systematic study on the superconducting transition width as a function of the applied magnetic field was performed in polycrystalline MgB2. A quantitative, yet universal relation between the two parameters was observed in all of the ceramics. It was found that the width decreases linearly with decreasing field in pure MgB2 samples. Whereas, samples with boron and/or Mg atoms partially replaced by other elements show this linear relation in the temperature range below 0.7–0.8 of the superconducting transition temperature (corresponding to a field of about 2 T), at temperatures higher than this range, an abnormal upturn in the width was found. This upturn is ascribed to multiple superconducting transitions. A core-shell model is proposed to describe the multiple transitions.
Analysis of passive scalar advection in parallel shear flows: Sorting of modes at intermediate time scales
Authors: Camassa Roberto , McLaughlin Richard M. , Viotti Claudio
Published: November 2010

The time evolution of a passive scalar advected by parallel shear flows is studied for a class of rapidly varying initial data. Such situations are of practical importance in a wide range of applications from microfluidics to geophysics. In these contexts, it is well-known that the long-time evolution of the tracer concentration is governed by Taylor’s asymptotic theory of dispersion. In contrast, we focus here on the evolution of the tracer at intermediate time scales. We show how intermediate regimes can be identified before Taylor’s, and in particular, how the Taylor regime can be delayed indefinitely by properly manufactured initial data. A complete characterization of the sorting of these time scales and their associated spatial structures is presented. These analytical predictions are compared with highly resolved numerical simulations. Specifically, this comparison is carried out for the case of periodic variations in the streamwise direction on the short scale with envelope modulations on the long scales, and show how this structure can lead to “anomalously” diffusive transients in the evolution of the scalar onto the ultimate regime governed by Taylor dispersion. Mathematically, the occurrence of these transients can be viewed as a competition in the asymptotic dominance between large Péclet (Pe) numbers and the long/short scale aspect ratios (LVel/LTracer≡k), two independent nondimensional parameters of the problem. We provide analytical predictions of the associated time scales by a modal analysis of the eigenvalue problem arising in the separation of variables of the governing advection-diffusion equation. The anomalous time scale in the asymptotic limit of large k Pe is derived for the short scale periodic structure of the scalar’s initial data, for both exactly solvable cases and in general with WKBJ analysis. In particular, the exactly solvable sawtooth flow is especially important in that it provides a short cut to the exact solution to the eigenvalue problem for the physically relevant vanishing Neumann boundary conditions in linear-shear channel flow. We show that the life of the corresponding modes at large Pe for this case is shorter than the ones arising from shear free zones in the fluid’s interior. A WKBJ study of the latter modes provides a longer intermediate time evolution. This part of the analysis is technical, as the corresponding spectrum is dominated by asymptotically coalescing turning points in the limit of large Pe numbers. When large scale initial data components are present, the transient regime of the WKBJ (anomalous) modes evolves into one governed by Taylor dispersion. This is studied by a regular perturbation expansion of the spectrum in the small wavenumber regimes.
Effective Floquet Hamiltonians for dipolar and quadrupolar coupled N-spin systems in solid state nuclear magnetic resonance under magic angle spinning
Authors: Pandey Manoj Kumar , Krishnan Mangala Sunder
Published: November 2010

Spin dynamics under magic angle spinning has been studied using different theoretical approaches and also by extensive numerical simulation programs. In this article we present a general theoretical approach that leads to analytic forms for effective Hamiltonians for an N-spin dipolar and quadrupolar coupled system under magic angle spinning (MAS) conditions, using a combination of Floquet theory and van Vleck (contact) transformation. The analytic forms presented are shown to be useful for the study of MAS spin dynamics in solids with the help of a number of simulations in two, three, and four coupled, spin-1/2 systems as well as spins in which quadrupolar interactions are also present.