642 research outputs found

    Full-Coupled Channel Approach to Doubly Strange ss-Shell Hypernuclei

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    We describe {\it ab initio} calculations of doubly strange, S=2S=-2, ss-shell hypernuclei (ΛΛ4^4_{\Lambda\Lambda}H, ΛΛ5^5_{\Lambda\Lambda}H, ΛΛ5^5_{\Lambda\Lambda}He and ΛΛ6^6_{\Lambda\Lambda}He) as a first attempt to explore the few-body problem of the {\it full}-coupled channel scheme for these systems. The wave function includes ΛΛ\Lambda\Lambda, ΛΣ\Lambda\Sigma, NΞN\Xi and ΣΣ\Sigma\Sigma channels. Minnesota NNNN, D2^\prime YNYN, and simulated YYYY potentials based on the Nijmegen hard-core model, are used. Bound state solutions of these systems are obtained. We find that a set of phenomenological B8B8B_8B_8 interactions among the octet baryons in S=0,1S=0, -1 and -2 sectors, which is consistent with all of the available experimental binding energies of S=0,1S=0, -1 and -2 ss-shell (hyper-)nuclei, can predict a particle stable bound state of ΛΛ4^4_{\Lambda\Lambda}H. For ΛΛ5^5_{\Lambda\Lambda}H and ΛΛ5^5_{\Lambda\Lambda}He, ΛNΣN\Lambda N-\Sigma N and ΞNΛΣ\Xi N-\Lambda\Sigma potentials enhance the net ΛΛNΞ\Lambda\Lambda-N\Xi coupling, and a large Ξ\Xi probability is obtained even for a weaker ΛΛNΞ\Lambda\Lambda-N\Xi potential.Comment: 4 pages, 1 figur

    Examining the Product Quality Attributes that influences customer satisfaction most when the price was discounted: A case study in Kuching Sarawak

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    The study is about customer satisfaction towards the product quality. The effect of low pricing product with the product quality plays the same result of low price products produces low quality product and vice-versa. Data instrument that is used in obtaining data is by distributing survey questionnaire. The main purpose of this research is to classify whether the eight dimension of product quality after price discounting is satisfying towards customer. The respondent of the research was chosen through sampling method by using the non-probability sampling. The results infer that that the customer’s satisfaction towards the discounted product quality is based on the three attributes most namely perceived quality, performance and reliability. The Perceived quality- on image, brand name, and advertising is positively related to the level of satisfaction towards the quality of discounted product; were all supported as the relationships between the variables were statistically significant. This study does also provide useful guidelines for future researcher to be more rigorous and also in-depth to empirical and theoretical processes. In future study, customer satisfaction towards discounted product quality of the product to be specified to a product only determine by one gender (female) and also a perception towards a certain discounted price level of a product and its quality with extension of product design and customer requirements

    Lambda Lambda-XiN Coupling Effects in Light Hypernuclei

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    The significance of ΛΛ\Lambda\Lambda-Ξ\XiN coupling in double-Λ\Lambda hypernuclei has been studied. The Pauli suppression effect due to this coupling in ΛΛ6^6_{\Lambda\Lambda}He has been found to be 0.43 MeV for the coupling strength of the NSC97e potential. This indicates that the free-space ΛΛ\Lambda\Lambda interaction is stronger by about 55^{\circ} phase shift than that deduced from the empirical data of ΛΛ6^6_{\Lambda\Lambda}He without including the Pauli suppression effect. In ΛΛ5^5_{\Lambda\Lambda}He and ΛΛ5^5_{\Lambda\Lambda}H, an attractive term arising from ΛΛ\Lambda\Lambda-Ξ\XiN conversion is enhanced by the formation of an alpha particle in intermediate Ξ\Xi states. According to this enhancement, we have found that the ΛΛ\Lambda\Lambda binding energy (ΔBΛΛ\Delta B_{\Lambda\Lambda}) of ΛΛ5^5_{\Lambda\Lambda}He is about 0.27 MeV larger than that of ΛΛ6^6_{\Lambda\Lambda}He for the NSC97e coupling strength. This finding deviates from a general picture that the heavier is the core nucleus, the larger is ΔBΛΛ\Delta B_{\Lambda\Lambda}.Comment: 16 pages with 2 figure

    Eikonal solutions to optical model coupled-channel equations

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    Methods of solution are presented for the Eikonal form of the nucleus-nucleus coupled-channel scattering amplitudes. Analytic solutions are obtained for the second-order optical potential for elastic scattering. A numerical comparison is made between the first and second order optical model solutions for elastic and inelastic scattering of H-1 and He-4 on C-12. The effects of bound-state excitations on total and reaction cross sections are also estimated

    An Econometric Analysis on the Co-Movement of Stock Market Volatility between China and ASEAN-5

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    This study aims to examine the co-movement of stock market volatility between China and ASEAN-5 countries from the year 2000 to 2009. This study applies the standard linear GARCH (1, 1) model where these models estimate using monthly price data from year 2000 to 2009 for China, Malaysia, Singapore, Thailand, Indonesia and Philippines. The standard time series econometrics analysis is used which are ADF unit root test, JJ co-integration test, and Granger causality test. The results indicate the co movement of stock market volatility between China and ASEAN-5 have fairly relation among them. The result shows there are two way relations which are bidirectional causality between china and Indonesia; China and Thailand; and China and Singapore. Meanwhile, there have no causality relation between China and Malaysia; and also China and Philippines. Though, it can be concluded that there are relationship between regions in the stock market volatility

    Stochastic Variational Search for ΛΛ4^{4}_{\Lambda\Lambda}H

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    A four-body calculation of the pnΛΛpn\Lambda\Lambda bound state, $^{\ 4}_{\Lambda\Lambda}H,isperformedusingthestochasticvariationalmethodandphenomenologicalpotentials.TheH, is performed using the stochastic variational method and phenomenological potentials. The NN,, \Lambda N,and, and \Lambda\LambdapotentialsaretakenfromarecentLetterbyFilikhinandGal,PRL89,172502(2002).AlthoughtheirFaddeevYakubovskycalculationfoundnoboundstatesolutionoverawiderangeof potentials are taken from a recent Letter by Filikhin and Gal, PRL{\bf 89}, 172502 (2002). Although their Faddeev-Yakubovsky calculation found no bound-state solution over a wide range of \Lambda\Lambdainteractionstrengths,thepresentvariationalcalculationgivesaboundstateenergy,whichisclearlylowerthanthe interaction strengths, the present variational calculation gives a bound-state energy, which is clearly lower than the _\Lambda^3{H}+\Lambdathreshold,evenforaweak threshold, even for a weak \Lambda\Lambdainteractionstrengthdeducedfromarecentexperimental interaction strength deduced from a recent experimental B_{\Lambda\Lambda}(^{6}_{\Lambda\Lambda}{He})value.Thebindingenergiesobtainedarecloseto,andslightlylargerthan,thevaluesobtainedfromthethreebody value. The binding energies obtained are close to, and slightly larger than, the values obtained from the three-body d\Lambda\Lambda$ model in the Letter.Comment: Corrected typos, added addtional calculations regarding a truncated to l=0 interaction model, 4 pages, 3 figure

    Case Studies on the Exploitation of Crowd-Sourcing with Web 2.0 Functionalities

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    Crowd-sourcing appears more promising with Web 2.0 functionality and businesses have started using it for a wide range of activities, that would be better completed by a crowd rather than any specific pool of knowledge workers. However, relatively little is known about how a business can leverage on collective intelligence and capture the user- generated value for competitive advantage. This empirical study uses the principle of interpretive field research to validate the case findings with a descriptive multiple case study methodology. An extended theoretical framework to identify the important considerations at strategic and functional levels for the effective use of crowd-sourcing is proposed. The analytic framework uses five Business Strategy Components: Vision and Strategy, Human Capital, Infrastructure, Linkage and Trust, and External Environment. It also uses four Web 2.0 Functional Components: Social Networking, Interaction Orientation, Customization & Personalization, and User- added Value. By using these components as analytic lenses, the case research examines how successful e-commerce firms may deploy Web 2.0 functionalities for effective use of crowd-sourcing. Prioritization of these functional considerations might be favorable in some cases for the best fit of situations and limitations. In conclusion, it is important that the alignment between strategy and functional components is maintained

    Hyperonic mixing in five-baryon double-strangeness hypernuclei in a two-channel treatment

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    Properties of hypernuclei ΛΛ5_{\Lambda \Lambda}^5H and ΛΛ5_{\Lambda \Lambda }^5He are studied in a two-channel approach with explicit treatment of coupling of channels ^3\text{Z}+\Lambda+\Lambda and \alpha+\Xi. Diagonal \Lambda\Lambda and coupling \Lambda\Lambda-\Xi N interactions are derived within G-matrix procedure from Nijmegen meson-exchange models. Bond energy \Delta B_{\Lambda\Lambda} in ΛΛ5_{\Lambda \Lambda}^5He exceeds significantly that in ΛΛ5_{\Lambda \Lambda}^5H due to the channel coupling. Diagonal \Xi\alpha attraction amplifies the effect, which is sensitive also to \Lambda-core interaction. The difference of the \Delta B_{\Lambda\Lambda} values can be an unambiguous signature of the \Lambda\Lambda-\Xi N coupling in \Lambda\Lambda hypernuclei. However, improved knowledge of the hyperon-nucleus potentials is needed for quantitative extraction of the coupling strength from future data on the \Lambda\Lambda hypernuclear binding energies.Comment: 11 pages with 3 figures; Phys. Rev. C, accepte

    Determination of quantitative and site-specific DNA methylation of perforin by pyrosequencing

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    <p>Abstract</p> <p>Background</p> <p>Differential expression of perforin (<it>PRF1</it>), a gene with a pivotal role in immune surveillance, can be attributed to differential methylation of CpG sites in its promoter region. A reproducible method for quantitative and CpG site-specific determination of perforin methylation is required for molecular epidemiologic studies of chronic diseases with immune dysfunction.</p> <p>Findings</p> <p>We developed a pyrosequencing based method to quantify site-specific methylation levels in 32 out of 34 CpG sites in the <it>PRF1 </it>promoter, and also compared methylation pattern in DNAs extracted from whole blood drawn into PAXgene blood DNA tubes (whole blood DNA) or DNA extracted from peripheral blood mononuclear cells (PBMC DNA) from the same normal subjects. Sodium bisulfite treatment of DNA and touchdown PCR were highly reproducible (coefficient of variation 1.63 to 2.18%) to preserve methylation information. Application of optimized pyrosequencing protocol to whole blood DNA revealed that methylation level varied along the promoter in normal subjects with extremely high methylation (mean 86%; range 82–92%) in the distal enhancer region (CpG sites 1–10), a variable methylation (range 49%–83%) in the methylation sensitive region (CpG sites 11–17), and a progressively declining methylation level (range 12%–80%) in the proximal promoter region (CpG sites 18–32) of <it>PRF1</it>. This pattern of methylation remained the same between whole blood and PBMC DNAs, but the absolute values of methylation in 30 out of 32 CpG sites differed significantly, with higher values for all CpG sites in the whole blood DNA.</p> <p>Conclusion</p> <p>This reproducible, site-specific and quantitative method for methylation determination of <it>PRF1 </it>based on pyrosequencing without cloning is well suited for large-scale molecular epidemiologic studies of diseases with immune dysfunction. PBMC DNA may be better suited than whole blood DNA for examining methylation levels in genes associated with immune function.</p

    Design and Validation of a Bifunctional Ligand Display System for Receptor Targeting

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    AbstractHere we developed a bacteriophage display particle designed to serve as a bifunctional entity that can target tumors while delivering an agent. We engineered a chimera phage vector containing a pIII-displayed αv integrins-targeting moiety and a pVIII-displayed streptavidin binding adaptor moiety. By using the chimeric phage particle, targeting of αv integrins on cells in culture and tumor-related blood vessels was shown through different applications, including luminescent quantum dots localization, surface plasmon resonance-based binding detection, and an in vivo tumor model. The strategy validated here will accelerate the discovery and characterization of receptor-ligand binding events in high throughput, and cell-specific delivery of diagnostics or therapeutics to organs of choice without the need for chemical conjugation
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