8,143 research outputs found

    Total Factor Productivity and R&D Capital in Manufacturing Industries

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    This study analyzes total factor productivity in manufacturing industries for a sample of OECD countries. The estimates of Malmquist indexes clearly indicate that research and development (R&D) capital is an important determinant of productivity growth in manufacturing industries. The empirical results also show that it is the pace, not the intensity, of R&D investment that is significantly related to the extent to which R&D capital formation contributes to output growth. Furthermore, this study finds that productivity gains in manufacturing industries depend importantly on R&D spillovers as well.

    Classification of the BPS states in Bagger-Lambert Theory

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    We classify, in a group theoretical manner, the BPS configurations in the multiple M2-brane theory recently proposed by Bagger and Lambert. We present three types of BPS equations preserving various fractions of supersymmetries: in the first type we have constant fields and the interactions are purely algebraic in nature; in the second type the equations are invariant under spatial rotation SO(2), and the fields can be time-dependent; in the third class the equations are invariant under boost SO(1,1) and provide the eleven-dimensional generalizations of the Nahm equations. The BPS equations for different number of supersymmetries exhibit the division algebra structures: octonion, quarternion or complex.Comment: 28+1 pages, No figure; v2 Sec.3.3 slightly expanded, typos fixed; v3 some comments added, to appear in JHE

    Determinants of Mid-scale Hotel Brand Equity

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    The traditional brand management in the hotel industry is facing a great challenge as numerous brands provide many choices to hotel guests. In such competitive environments, hotel firms realize that capitalizing on one of the most important assests they own- the brand- is critical to achieve a premier growth goal not only rapidly but also in a cost- effective way. THe purpose of this study is to examine the determinants of cutsomer-based hotel brand equity for the mid-priced U.S. lodging segment by assessing the impacts of four-widely accepted brand equity dimensions: brand awareness, brand associations, percieved quality and customer loyalty. 277 travelers participated in this study at the airport in a Midwestern city. Perceived quality, brand loyalty, brand associations were found to be the core components of brand equity, while brand awareness, a seemingly important source of brand equity, did not exert a significant influence on building brand equity of mid-priced hotels. The result of this study sheds insight about how to create, manage, and evaluate a distinctive and successful hotel brand

    Principal factors that determine the extension of detection range in molecular beacon aptamer/conjugated polyelectrolyte bioassays.

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    A strategy to extend the detection range of weakly-binding targets is reported that takes advantage of fluorescence resonance energy transfer (FRET)-based bioassays based on molecular beacon aptamers (MBAs) and cationic conjugated polyelectrolytes (CPEs). In comparison to other aptamer-target pairs, the aptamer-based adenosine triphosphate (ATP) detection assays are limited by the relatively weak binding between the two partners. In response, a series of MBAs were designed that have different stem stabilities while keeping the constant ATP-specific aptamer sequence in the loop part. The MBAs are labeled with a fluorophore and a quencher at both termini. In the absence of ATP, the hairpin MBAs can be opened by CPEs via a combination of electrostatic and hydrophobic interactions, showing a FRET-sensitized fluorophore signal. In the presence of ATP, the aptamer forms a G-quadruplex and the FRET signal decreases due to tighter contact between the fluorophore and quencher in the ATP/MBA/CPE triplex structure. The FRET-sensitized signal is inversely proportional to [ATP]. The extension of the detection range is determined by the competition between opening of the ATP/MBA G-quadruplex by CPEs and the composite influence by ATP/aptamer binding and the stem interactions. With increasing stem stability, the weak binding of ATP and its aptamer is successfully compensated to show the resistance to disruption by CPEs, resulting in a substantially broadened detection range (from millimolar up to nanomolar concentrations) and a remarkably improved limit of detection. From a general perspective, this strategy has the potential to be extended to other chemical- and biological-assays with low target binding affinity

    Microspinning: Local Surface Mixing via Rotation of Magnetic Microparticles for Efficient Small-Volume Bioassays

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    The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy
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