2,310 research outputs found

    Unfair competition governs the interaction of pCPI-17 with myosin phosphatase (PP1-MYPT1).

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    The small phosphoprotein pCPI-17 inhibits myosin light-chain phosphatase (MLCP). Current models postulate that during muscle relaxation, phosphatases other than MLCP dephosphorylate and inactivate pCPI-17 to restore MLCP activity. We show here that such hypotheses are insufficient to account for the observed rapidity of pCPI-17 inactivation in mammalian smooth muscles. Instead, MLCP itself is the critical enzyme for pCPI-17 dephosphorylation. We call the mutual sequestration mechanism through which pCPI-17 and MLCP interact inhibition by unfair competition: MLCP protects pCPI-17 from other phosphatases, while pCPI-17 blocks other substrates from MLCP\u27s active site. MLCP dephosphorylates pCPI-17 at a slow rate that is, nonetheless, both sufficient and necessary to explain the speed of pCPI-17 dephosphorylation and the consequent MLCP activation during muscle relaxation

    Alternative Broadcasting Arrangements after NCAA

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    SYMPOSIUM: Antitrust Issues In Amateur Sports Held at Indiana University School of Law - March 198

    Alternative Broadcasting Arrangements after NCAA

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    SYMPOSIUM: Antitrust Issues In Amateur Sports Held at Indiana University School of Law - March 198

    Paired atom laser beams created via four-wave mixing

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    A method to create paired atom laser beams from a metastable helium atom laser via four-wave mixing is demonstrated. Radio frequency outcoupling is used to extract atoms from a Bose Einstein condensate near the center of the condensate and initiate scattering between trapped and untrapped atoms. The unequal strengths of the interactions for different internal states allows an energy-momentum resonance which leads to the creation of pairs of atoms scattered from the zero-velocity condensate. The resulting scattered beams are well separated from the main atom laser in the 2-dimensional transverse atom laser profile. Numerical simulations of the system are in good agreement with the observed atom laser spatial profiles, and indicate that the scattered beams are generated by a four-wave mixing process, suggesting that the beams are correlated.Comment: 5 pages, 3 figure

    Legume Re-Establishment in Pastures after the Application of Residual Herbicides

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    Integrated management of pastures and hayfields sometimes require the application of broadleaf herbicides to manage weeds. Weed infestations are usually caused by a variety of factors including but not limited to drought, poor grazing management, and feeding weed infested hay in pastures. Weeds can adversely affect livestock access to forage as well as reduce forage quantity and quality. Producers are often hesitant to apply herbicides to manage weeds because of the effect the herbicides will have on forage legumes present in the pasture

    Co- variation in soil biodiversity and biogeochemistry in northern and southern Victoria Land, Antarctica

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    Data from six sites in Victoria Land (72–77°S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties showthe influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific sites in northern and southern Victoria Land, as was the distribution of nematode and tardigrade species. Variation in soil metazoan communities was related to differences in soil organic matter, while bacterial diversity and community structure were not strongly correlated with any single soil property. There were no apparent correlations between metazoan and bacterial diversity, suggesting that controls over distribution and habitat suitability are different for bacterial and metazoan communities. Our results imply that top-down controls over bacterial diversity mediated by their metazoan consumers are not significant determinants of bacterial community structure and biomass in these ecosystems

    Contextual Influences and Strategies for Dissemination and Implementation in Mental Health

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    Implementation science has emerged to bridge the gap between research and practice. A number of conceptual frameworks have been developed to advance implementation research and illuminate the contextual influences that can facilitate or impede the implementation of evidence-based practices. Contextual factors that may be important in the dissemination and implementation of evidence-based practice may occur at the system-, organizational-, and provider-levels. System-level barriers may include external policies, incentives, and peer pressure. Organizational-level factors that are important in implementation include organizational culture and climate and implementation climate. At the individual provider-level, barriers may occur around provider attitudes, knowledge, and self-efficacy. Finally, additional barriers such as client-level that can be used to overcome contextual barriers when attempting to implement evidence-based practices into new settings. Several exemplar implementation strategies are discussed, including the Availability, Responsiveness, and Continuity intervention, Community Development Team model, and Interagency Collaborative Team Model

    Efficient, Low Pressure Ratio Propulsor for Gas Turbine Engines

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    A gas turbine engine includes a gear assembly and a bypass flow passage that includes an inlet and an outlet that define a design pressure ratio between 1.3 and 1.55. A fan is arranged at the inlet. A first turbine is coupled with a first shaft such that rotation of the first turbine will drive the fan, through the first shaft and the gear assembly, at a lower speed than the first shaft. The fan includes a row of fan blades. The row includes 12-16 (N) fan blades, a solidity value (R) that is from 1.0 to 1.3, and a ratio of N/R that is from 10.0 to 16

    Context-Bounded Analysis For Concurrent Programs With Dynamic Creation of Threads

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    Context-bounded analysis has been shown to be both efficient and effective at finding bugs in concurrent programs. According to its original definition, context-bounded analysis explores all behaviors of a concurrent program up to some fixed number of context switches between threads. This definition is inadequate for programs that create threads dynamically because bounding the number of context switches in a computation also bounds the number of threads involved in the computation. In this paper, we propose a more general definition of context-bounded analysis useful for programs with dynamic thread creation. The idea is to bound the number of context switches for each thread instead of bounding the number of switches of all threads. We consider several variants based on this new definition, and we establish decidability and complexity results for the analysis induced by them

    Efficient, Low Pressure Ratio Propulsor for Gas Turbine Engines

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    A gas turbine engine includes a core flow passage, a bypass flow passage, and a propulsor arranged at an inlet of the bypass flow passage and the core flow passage. The propulsor includes a row of propulsor blades. The row includes no more than 20 of the propulsor blades. The propulsor has a pressure ratio between about 1.2 and about 1.7 across the propulsor blades
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