501 research outputs found

    Channel strategy adaptation

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    Using transaction cost theory, considerable research in marketing has focused on the conditions under which firms would use direct or vertically integrated versus indirect or arms length channels of distribution. Data from the field, however, indicate that channel configurations are more varied and complex, with multiple channels and composite channels being just as common as direct and indirect channels. In an attempt to explain this variety, this paper revisits the influence on channel structure of another contending variable, namely environmental complexity. We explore the role and influence of its two components, namely volatility (stability) and heterogeneity (homogeneity). Our study of 139 firms in the healthcare industry reveals that firms facing highly volatile and customer concentrated environments tend to use direct channels, and firms facing highly stable and heterogeneous environments tend to use distribution channels. Intermediate forms such as composite channels and multiple channels were favored by firms facing combinations of the environment where the intensity of one component was high and the other low. In general, firms seem to first choose a business strategy to address their external environment, and then choose a channel strategy to support that business strategy. Firms did not always adapt by making structural changes. Under certain conditions, they simply reallocated channel functions within the same structure, thus virtually deriving all the benefits of a new structure without having to create one.marketing; channels of distribution;

    Channel strategy: Formulation and adaptation

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    Inspired by open systems theories like the structural contingency theory (Lawrence and Lorsch 1967), population ecology theory (Hannan and Freeman 1977), and resource dependence theory (Pfeffer and Salancik 1978), several marketing scholars have investigated how channels adapt and organize themselves to cope with their environments. Curiously, however, the implication of such adaptive behaviour (i.e., the better adapted firms are more profitable) has not been investigated in the marketing literature. This paper aims to probe that question. Moreover, unlike previous marketing studies, we articulate the manufacturer's rather than the distributor's point-of-view, because channel strategy decisions are usually in the manufacturer's domain. We scrutinize firms' adaptive responses from a channel structure and channel task perspective. Results show that the better adapted firms deliver superior performance, and that the adaptive responses often occur subtly at the specific channel task level even when the channel structure itself may appear seemingly unaltered.structural contingency theory; population ecology theory; resource dependence theory;

    Absolute Neutron Flux from a Raα+Be Source

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    Remote sensing technique- a tool for environmental studies

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    Environment belongs to all and is important to all. As per definition of the Environment Protection Act, environment includes all the physical and biological surroundings and their interactions. The study of environment or rather environmental studies is a multi-disciplinary which needs knowledge interest from physical sciences (physics, chemistry, mathematics), biological sciences (botany, zoology, microbiology, biochemistry), social sciences, economics, sociology, education, geography) etc

    High-Performance Silicon-Based Multiple Wavelength Source

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    We demonstrate a stable CMOS-compatible on-chip multiple-wavelength source by filtering and modulating individual lines from a frequency comb generated by a microring resonator optical parametric oscillator.. We show comb operation in a low-noise state that is stable and usable for many hours. Bit-error rate measurements demonstrate negligible power penalty from six independent frequencies when compared to a tunable diode laser baseline. Open eye diagrams confirm the fidelity of the 10 Gb/s data transmitted at the comb frequencies and the suitability of this device for use as a fully integrated silicon-based WDM source.Comment: 3 pages, 3 figure

    Enhanced Two-Photon Absorption in a Hollow-Core Photonic Bandgap Fiber

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    We show that two-photon absorption (TPA) in Rubidium atoms can be greatly enhanced by the use of a hollow-core photonic bandgap fiber. We investigate off-resonant, degenerate Doppler-free TPA on the 5S1/2 - 5D5/2 transition and observe 1% absorption of a pump beam with a total power of only 1 mW in the fiber. These results are verified by measuring the amount of emitted blue fluorescence and are consistent with the theoretical predictions which indicate that transit time effects play an important role in determining the two-photon absorption cross-section in a confined geometry.Comment: 5 pages, 6 figure

    A model-based approach for detection of objects in low resolution passive-millimeter wave images

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    We describe a model-based vision system to assist pilots in landing maneuvers under restricted visibility conditions. The system was designed to analyze image sequences obtained from a Passive Millimeter Wave (PMMW) imaging system mounted on the aircraft to delineate runways/taxiways, buildings, and other objects on or near runways. PMMW sensors have good response in a foggy atmosphere; but, their spatial resolution is very low. However, additional data such as airport model and approximate position and orientation of aircraft are available. We exploit these data to guide our model-based system to locate objects in the low resolution image and generate warning signals to alert the pilots. We also derive analytical expressions for the accuracy of the camera position estimate obtained by detecting the position of known objects in the image

    Identification of the Moving Junction Complex of Toxoplasma gondii: A Collaboration between Distinct Secretory Organelles

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    Apicomplexan parasites, including Toxoplasma gondii and Plasmodium sp., are obligate intracellular protozoa. They enter into a host cell by attaching to and then creating an invagination in the host cell plasma membrane. Contact between parasite and host plasma membranes occurs in the form of a ring-shaped moving junction that begins at the anterior end of the parasite and then migrates posteriorly. The resulting invagination of host plasma membrane creates a parasitophorous vacuole that completely envelops the now intracellular parasite. At the start of this process, apical membrane antigen 1 (AMA1) is released onto the parasite surface from specialized secretory organelles called micronemes. The T. gondii version of this protein, TgAMA1, has been shown to be essential for invasion but its exact role has not previously been determined. We identify here a trio of proteins that associate with TgAMA1, at least one of which associates with TgAMA1 at the moving junction. Surprisingly, these new proteins derive not from micronemes, but from the anterior secretory organelles known as rhoptries and specifically, for at least two, from the neck portion of these club-shaped structures. Homologues for these AMA1-associated proteins are found throughout the Apicomplexa strongly suggesting that this moving junction apparatus is a conserved feature of this important class of parasites. Differences between the contributing proteins in different species may, in part, be the result of selective pressure from the different niches occupied by these parasites

    Evidence for inhibitory interaction of hyaluronan-binding protein 1 (HABP1/p32/gC1qR) with Streptococcus pneumoniae hyaluronidase

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    Bacterial hyaluronan lyase enzymes are the major virulence factors that enable greater microbial ingress by cleaving hyaluronan (HA) polymers present predominantly in extracellular space of vertebrates. Based on the premise that effective inhibitors may bind to and stabilize HA thereby protecting it from degradation, here we investigated inhibitory activity of human hyaluronan-binding protein 1 (HABP1) on bacterial hyaluronidase because it is highly specific to HA and localized on the cell surface. Biochemical characterization revealed that HABP1 is a competitive inhibitor of Streptococcus pneumoniae hyaluronate lyase (SpnHL) with an IC50 value of 22 μm. This is thus the first report of an endogenous protein inhibitor that may be used during natural antibacterial defense. Our findings also support a novel multipronged mechanism for the high efficacy of HABP1-mediated inhibition based on structural modeling of enzyme, substrate, and inhibitor. Evidence from docking simulations and contact interface interactions showed that the inherent charge asymmetry of HABP1 plays a key role in the inhibitory activity. This novel role of HABP1 may pave the way for peptide inhibitors as alternatives to synthetic chemicals in antibacterial research
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