bluuebunny/crossref_metadata_2025_split huggingface dataset:
From commodity computers to high‐performance environments: scalability analysis using self‐similarity, large deviations and heavy‐tails
Authors: Ramirez‐Velarde Raul V. , Rodríguez‐Dagnino Ramón M. 
Published: September 2009

AbstractWe derive two scalability models for high‐performance distributed environments using low‐cost, low‐performance components. On the first model, we approximate the tail of the probability distribution by using the Pareto probability distribution and then build a stochastic model to determine the maximum user‐load per server according to certain quality of service parameters. On the second model, we use a probabilistic measure to determine the ratio of computing servers to storage servers and thus complete the performance model. The data of execution traces obtained from the testbed is analyzed. Hurst parameter is estimated using the Abry–Veitch estimator and distribution parameters are estimated for different probability distributions. Models based on the Pareto and Gamma probability distributions are developed and used with the data that was analyzed. There seems to be a good agreement between our models, the experimental execution traces, and simulations of HP computing environments. Specifically, thePareto Fractal Flowmodel is compared with other models based on the Gamma and Gaussian distributions, such as the FGN andM/G/∞, and it seems to make better predictions under our experimental conditions. Results are presented comparing analytical models with simulation results. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of Bi‐content on hardness and micro‐creep behavior of Sn‐3.5Ag rapidly solidified alloy
Authors: Kamal M. , Gouda El Said , Marei L. K. 
Published: September 2009

AbstractIn the present paper, the influence of 1, 3, 5 and 10 % Bi (weight %) as ternary additions on structure, melting and mechanical properties of rapidly solidified Sn‐3.5Ag alloy has been investigated. The effect of Bi was discussed based on the experimental results. The experimental results showed that the alloys of Sn‐3.5Ag, Sn‐3.5Ag‐1Bi and Sn‐3.5Ag‐3Bi are composed of two phases; Ag3Sn IMC embedded in Sn matrix phase, which indicated that the solubility of Bi phase in Sn‐matrix was extended to 3 % as a result of rapid solidification. Bi precipitation in Sn matrix was only observed in Sn‐3.5Ag‐5Bi and Sn‐3.5Ag‐10Bi alloys. Also, addition of Bi decreased continuously the melting point of the eutectic Sn‐3.5Ag alloy to 202.6 °C at 10 % Bi. Vickers hardness of Sn‐3.5Ag rapidly solidified alloy increased with increasing Bi content up to 3 % due to supersaturated solid solution strengthening hardening mechanism of Bi phase in Sn matrix, while the alloys contain 5 and 10 % Bi exhibited lower values of Vickers hardness. The lower values can be attributed to the precipitation of Bi as a secondary phase which may form strained regions due to the embrittlement of Bi atom. In addition, the effect of Bi addition on the micro‐creep behavior of Sn‐3.5Ag alloy as well as the creep rate have been described and has been calculated at room temperature. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid flow cytometric method for measuring senescence associated β‐galactosidase activity in human fibroblasts
Authors: Noppe Gerard , Dekker Pim , de Koning‐Treurniet Corine , Blom Joke , van Heemst Diana , Dirks Roeland W. , Tanke Hans J. , Westendorp Rudi G. J. , Maier Andrea B. 
Published: September 2009

AbstractSenescence associated‐β‐galactosidase (SA‐β‐gal) activity is a widely used marker for cellular senenescence. SA‐β‐gal activity is routinely detected cytochemically, manually discriminating negative from positive cells. This method is time‐consuming, subjective and therefore prone to operator‐error. We aimed to optimize a flow cytometric method described by other workers using endothelial cells to better differentiate between populations of fibroblasts in degrees of SA‐β‐gal activity. Skin fibroblasts were isolated from young (mean age ± SD: 25.5 ± 1.8) and very old (age 90.2 ± 0.3) subjects. Different pH modulators were tested for toxicity. To induce stress‐induced senescence, fibroblasts were exposed to rotenone. Senescence was assessed measuring SA‐β‐gal activity by cytochemistry (X‐gal) and by flow cytometry (C12FDG). The pH modulator Bafilomycin A1 (Baf A1) was found to be least toxic for fibroblasts and to differentiate best between nonstressed and stressed fibroblast populations. Under nonstressed conditions, fibroblasts from very old subjects showed higher SA‐β‐gal activity than fibroblasts from young subjects. This difference was found for both the flow cytometric and cytochemical methods (P = 0.013 and P = 0.056 respectively). Under stress‐induced conditions the flow cytometric method but not the cytochemical method revealed significant higher SA‐β‐gal activity in fibroblasts from very old compared to young subjects (P = 0.004 and P = 0.635 respectively). We found the modified flow cytometric method measuring SA‐β‐gal activity superior in discriminating between degrees of senescence in different populations of fibroblasts. © 2009 International Society for Advancement of Cytometry
Regioselective Domino Metathesis of Unsymmetrical 7‐Oxanorbornenes with Electron‐Rich Vinyl Acetate toward Biologically Active Glutamate Analogues
Authors: Oikawa Masato , Ikoma Minoru , Sasaki Makoto , Gill Martin B. , Swanson Geoffrey T. , Shimamoto Keiko , Sakai Ryuichi 
Published: September 2009

AbstractIn this article a regioselective domino metathesis reaction of unsymmetrical 7‐oxanorbornenes, readily available by a tandem Ugi/Diels–Alder reaction as a key step, promoted by the Hoveyda–Grubbs second‐generation catalyst in the presence of electron‐rich vinyl acetate as a cross metathesis (CM) substrate is reported. The mechanism for the unusually high regioselectivity observed in the CM reaction was investigated, and a reaction course where a Fischer‐type carbene [“Ru”=CH(OAc)] generates a steric interaction is proposed. Themetathesis products were further converted to four artificial glutamate analogues whose structures were inspired by naturally derived excitatory glutamate analogues, dysiherbaine and neodysiherbaine. Interestingly, one of the synthetic analogues (28a) induced a cataleptic state in mice. Further electrophysiological studies suggest that28amight inhibit excitatory synaptic transmission by a yet unknown indirect pathway.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Label‐Free and Ultra‐Low Level Detection of Salmonella enterica Serovar Typhimurium Using Electrochemical Impedance Spectroscopy
Authors: La Belle Jeffrey T. , Shah Miti , Reed Justin , Nandakumar Vivek , Alford T. L. , Wilson James W. , Nickerson Cheryl A. , Joshi Lokesh 
Published: September 2009

AbstractAn immunosensor for rapid and low level detection of the bacterial pathogen Salmonella enterica Serovar Typhimurium was designed and developed based upon label‐free electrochemical impedance spectroscopy and correlated to viable cell counts. The immunosensor was fabricated by electroplating gold onto a disposable printed circuit board (PCB) electrode by immobilizing monoclonal antibody (MAb) specific against Salmonella typhimurium cell surface lipopolysaccharide (LPS) onto the surface of the electrode. Use of mass‐fabricated and electroplated PCB electrodes allowed for disposable, highly sensitive, and rapid detection of Salmonella in an aqueous environment. Results demonstrate that in purified solution, Salmonella can be detected as low as 10 CFU in a 100 μL volume and label‐free and rapid manner in fewer than 90 s. The cost effective approach described here can be used for detection of pathogens with relevance for healthcare, food, and environmental applications.
The neural response to changing semantic and perceptual complexity during language processing
Authors: Sharp David J. , Awad Malaka , Warren Jane E. , Wise Richard J.S. , Vigliocco Gabriella , Scott Sophie K. 
Published: September 2009

AbstractSpeech comprehension involves processing at different levels of analysis, such as acoustic, phonetic, and lexical. We investigated neural responses to manipulating the difficulty of processing at two of these levels. Twelve subjects underwent positron emission tomographic scanning while making decisions based upon the semantic relatedness between heard nouns. We manipulated perceptual difficulty by presenting either clear or acoustically degraded speech, and semantic difficulty by varying the degree of semantic relatedness between words. Increasing perceptual difficulty was associated with greater activation of the left superior temporal gyrus, an auditory‐perceptual region involved in speech processing. Increasing semantic difficulty was associated with reduced activity in both superior temporal gyri and increased activity within the left angular gyrus, a heteromodal region involved in accessing word meaning. Comparing across all the conditions, we also observed increased activation within the left inferior prefrontal cortex as the complexity of language processing increased. These results demonstrate a flexible system for language processing, where activity within distinct parts of the network is modulated as processing demands change. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Evaluation of the immunogenicity and cell compatibility of avian collagen for biomedical applications
Authors: Peng Yong Y. , Glattauer Veronica , Ramshaw John A. M. , Werkmeister Jerome A. 
Published: September 2009

AbstractThere have been concerns regarding the suitability of bovine collagen as a biomaterial since the emergence of bovine spongiform encephalopathy. Consequently, collagens from other species may be used if they can meet appropriate standards, including negligible or lack of immunogenicity. In this study, the potential immunogenicity of both monomeric and pepsin‐solubilized chicken collagens have been compared with a commercial, pepsin‐solubilized bovine collagen that is approved for biomedical implantation. All collagens were poor immunogens compared with ovalbumin. No IgE responses were detected in sera of three strains of mice, and no hypersensitivity reactions were found in guinea pigs in maximization and Buehler tests. IgG1 antibodies were found although the titre was substantially lower than against ovalbumin. All responses in mice and rabbits were found only when immunizations were performed with adjuvant, and after multiple injections over a long period of time. The response from the monomeric chicken collagen was less than for pepsin‐solubilized collagens. Collagen sponges prepared from the two chicken collagen preparations both supported the attachment and growth of mouse fibroblasts. These data indicate that chicken collagen, particularly when monomeric, may be useful in certain biomedical applications. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
The notch‐responsive transcription factor Hes‐1 attenuates osteocalcin promoter activity in osteoblastic cells
Authors: Zhang Ying , Lian Jane B. , Stein Janet L. , van Wijnen Andre J. , Stein Gary S. 
Published: September 2009

AbstractNotch signaling plays a key role in osteoblast differentiation. A major transcriptional downstream regulator of this pathway is the helix–loop–helix (HLH) transcription factor Hairy/Enhancer of Split 1 (Hes‐1). Here we investigated the function of Hes‐1 in osteoblastic cells. Endogenous Hes‐1 gene expression decreases during progression of bone cell phenotype development in MC3T3‐E1 osteoblasts suggesting that it is a negative regulator of osteoblast differentiation. Forced expression of Hes‐1 inhibits osteocalcin (OC) mRNA levels, and luciferase assays indicate that Hes‐1 directly represses OC promoter activity. In vitro and in vivo protein/DNA interaction assays reveal that recombinant Hes‐1 binds specifically to an E‐box in the proximal promoter of the OC gene. Deletion of the Hes‐1 WRPW domain (MHes‐1) that recruits the co‐repressor Groucho abrogates repression of OC promoter activity by Hes‐1, but also blocks Hes‐1 binding to the promoter. The latter result suggests that exogenous Hes‐1 may be recruited to the OC promoter by both protein/DNA and protein/protein interactions. We conclude that the Notch‐responsive Hes‐1 protein is capable of repressing OC gene transcription in osteoblastic cells through an E‐box in the proximal promoter. Hes‐1 may contribute to osteoblast growth and differentiation by controlling basal bone‐specific transcription directly through interactions with transcriptional regulators that are known to bind to the OC gene promoter. J. Cell. Biochem. 108: 651–659, 2009. © 2009 Wiley‐Liss, Inc.
An information‐theoretic approach to the prediction of protein structural class
Authors: Zheng Xiaoqi , Li Chun , Wang Jun 
Published: September 2009

AbstractAn information‐theoretical approach, which combines a sequence decomposition technique and a fuzzy clustering algorithm, is proposed for prediction of protein structural class. This approach could bypass the process of selecting and comparing sequence features as done previously. First, distances between each pair of protein sequences are estimated using a conditional decomposition technique in information theory. Then, the fuzzy k‐nearest neighbor algorithm is used to identify the structural class of a protein given as set of sample sequences. To verify the strength of our method, we choose three widely used datasets constructed by Chou and Zhou. It is shown by the Jackknife test that our approach represents an improvement in the prediction of accuracy over existing methods. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Mathematical modelling of the impact of haematopoietic stem cell‐delivered gene therapy for HIV
Authors: Murray John M. , Fanning Greg C. , Macpherson Janet L. , Evans Louise A. , Pond Susan M. , Symonds Geoff P. 
Published: September 2009

AbstractBackgroundGene therapy represents a new treatment paradigm for HIV that is potentially delivered by a safe, once‐only therapeutic intervention.MethodsUsing mathematical modelling, we assessed the possible impact of autologous haematopoietic stem cell (HSC) delivered, anti‐HIV gene therapy. The therapy comprises a ribozyme construct (OZ1) directed to a conserved region of HIV‐1 delivered by transduced HSC (OZ1+HSC). OZ1+HSC contributes to the CD4+ T lymphocyte and monocyte/macrophage cell pools that preferentially expand under the selective pressure of HIV infection. The model was used to predict the efficacy of OZ1 in a highly active antiretroviral therapy (HAART) naïve individual and a HAART‐experienced individual undergoing two structured treatment operations. In the standard scenario, OZ1+HSC was taken as 20% of total body HSC.ResultsFor a HAART‐naïve individual, modelling predicts a reduction of HIV RNA at 1 and 2 years post‐OZ1 therapy of 0.5 log10 and 1 log10, respectively. Eight years after OZ1 therapy, the CD4+ T‐lymphocyte count was 271 cells/mm3 compared to 96 cells/mm3 for an untreated individual. In a HAART‐experienced individual HIV RNA was reduced by 0.34 log10 and 0.86 log10 at 1 and 2 years. The OZ1 effect was maximal when both CD4+ T lymphocytes and monocytes/macrophages were protected from successful, productive infection by OZ1.ConclusionsThe modelling indicates a single infusion of HSC cell‐delivered gene therapy can impact on HIV viral load and CD4 T‐lymphocyte count. Given that gene therapy avoids the complications associated with HAART, there is significant potential for this approach in the treatment of HIV. Copyright © 2009 John Wiley & Sons, Ltd.
The impact of adsorption of bovine pancreatic trypsin inhibitor on CTAB‐protected gold nanoparticle arrays: a Raman spectroscopic comparison with solution denaturation
Authors: Kaminska Agnieszka , Forster Robert J. , Keyes Tia E. 
Published: September 2009

AbstractThe influence of an array of cetyltrimethylammonium bromide (CTAB)‐protected gold nanoparticles on the structure of a model protein, bovine pancreatic trypsin inhibitor (BPTI) at pH 7.4, was studied by Raman spectroscopy. The structural consequences of array adsorption were compared with the effects of deposition of the protein directly onto a roughened gold substrate and with thermal and reductive treatment of BPTI in solution. Both thermal and reductive denaturation in solution result in loss of α‐helix structure, with an increase in random conformations of the protein in the case of reductive denaturation and β‐sheet conformation and random coil on thermal denaturation. For reductive denaturation in particular, extensive loss of secondary structure is evident. Deposition of the protein onto the array resulted in increased β‐sheet conformation similar to that observed on thermal treatment of the protein. However, unlike denaturation, which for both thermal and reductive process resulted in changes in the disulfide stretching wavenumber, this remains largely unchanged on application of the protein to the array. Furthermore, deposition of the protein onto bare gold results in significant heterogeneity in the SS stretching signal with appearance of ggt and nonequilibrium geometry of the CCSSCC dihedral angles. Thermal denaturation results in a red shift of the SS mode, whereas dithiothreitol (DTT) treatment, as expected, induces significant loss of the SS stretching signal, although a signal at 517 cm−1 remains suggesting that the unreduced disulfide has changed to the ggt geometry. In addition, an SH mode is observed at 2570 cm−1 in solution. The response of BPTI to thermal and DTT treatment while on the array is very different to its solution behavior, and suggests that adhesion to the array increases the stability of the protein. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of oil type on the performance characteristics of a two‐axial groove journal bearing
Authors: McCarthy D. M. C. , Glavatskih S. B. , Byheden Å. 
Published: September 2009

AbstractThe use of environmentally adapted lubricants (EALs) is a subject of growing interest to industry as legislation increasingly demands the replacement of mineral oil lubricants. Vegetable‐based fluids are widely seen as providing lubricants from a renewable source, as well as meeting demands for improved biodegradability. However, at present, utilization of such fluids is limited due to their rapid oxidation. EALs produced from other base stocks (i.e. synthetic esters) have been shown to provide performance benefits in hydrodynamic thrust bearings. In the present study, a hydrodynamic journal bearing test rig has been employed to compare the performance of three EALs (a VG32 saturated ester, rapeseed base fluid and a propylene glycol dioleate) relative to three mineral turbine oils (ISOVG32, ISOVG46 and ISOVG68) in the hydrodynamic regime. Results are given in terms of temperature, power loss and minimum film thickness. The impact of oil viscosity index is also discussed. Copyright © 2009 John Wiley & Sons, Ltd.
A planar CPW‐fed slot antenna on thin substrate for dual‐band operation of WLAN applications
Authors: Yoon Cheol , Lee Won‐Jong , Kang Sang‐Pil , Kang Suk‐Youb , Lee Hwa‐Choon , Park Hyo‐Dal 
Published: September 2009

AbstractThis article presents the design and fabrication of a coplanar waveguide (CPW)‐fed slot antenna on thin substrate for dual‐band operation of wireless local‐area network (WLAN) applications within 2.400–2.484 GHz and 5.150–5.350/5.725–5.825 GHz bandwidths. The prototype consists of a thin substrate and a CPW‐fed slot antenna. To obtain sufficient bandwidth with −10 dB return loss, a thin substrate layer is inserted under the ground plate and the radiator. A thin substrate CPW‐fed slot antenna that has a WLAN‐band is used. The important design parameters are the slot's construction, width, length, the substrate height, and the CPW‐fed gaps. From these optimized parameters, a CPW‐fed slot antenna is fabricated and measured. The measured results of the fabricated antenna are obtained individually, at 1.70 and 2.40 GHz bandwidths, with a −10 dB return loss referenced to the center frequency, and with the individual peak gains at 1.37 and 1.78 dBi. The experimental radiation efficiency in both the E‐ and H‐planes is shown to be a pass band total of 48–75%. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2799–2802, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24742
Simple small‐size coupled‐fed uniplanar PIFA for multiband clamshell mobile phone application
Authors: Kang Ting‐Wei , Wong Kin‐Lu 
Published: September 2009

AbstractIn this study, a simple uniplanar printed PIFA occupying a small area of 10 × 40 mm2for achieving multiband operation in the clamshell mobile phone is presented. The proposed PIFA is formed by a simple shorted radiating strip coupled‐fed by a simple feeding strip and is mounted at the hinge of the clamshell mobile phone; further, the upper ground plane is connected to the main ground plane using an extended connecting strip. With the coupling feed and the connection arrangement between the main and upper ground planes, the proposed PIFA itself is not only an efficient radiator, it can also excite the two ground planes of the clamshell mobile phone as an efficient radiator (dipole‐like resonant modes are excited). Thus, with a small occupying area and a simple structure for the proposed PIFA, two wide operating bands at lower and higher frequencies can be provided to cover GSM850/900/1800/1900/UMTS bands for WWAN operation. The antenna also meets the 1‐g SAR specification of 1.6 W/kg required for practical applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2805–2810, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24756
A compact seven‐section rat‐race hybrid coupler incorporating PBG cells
Authors: Opozda S. , Kurgan P. , Kitlinski M. 
Published: September 2009

AbstractA conventional rat‐race coupler has been doubly miniaturized: (i) characteristic impedances and electrical lengths of microstrip sections have been adequately modified as the first step of size reduction and (ii) T‐shaped PBG cells have been implemented to diminish strip section length as the second step of circuit miniaturization. The experimental results show good agreement with theoretical characteristics. Furthermore, the proposed seven‐section PBG coupler enabled the achievement of 85% scale of size reduction in the final design, which proves the attractiveness of presented miniaturization method. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2910–2913, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24789
Vertically meander‐folded, shorted‐patch antennas
Authors: Holub Alois , Polívka Milan 
Published: September 2009

AbstractIn this study, a novel miniaturized microstrip patch antenna based on meander‐folded, shorted‐patch (SP) structure is introduced. The technique enables a decrease of the original quarter‐wavelength patch length approximately by the factor 1/N, where N is the number of the vertically placed patch plates above the ground plane. The antenna operational principle is explained with the help of E‐field distribution and can be interpreted as SP with vertically meander‐folded cavity. Further modification of the top patch plate to ensure symmetrical radiation pattern is proposed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2938–2942, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24790