4,267 research outputs found

    Data management study, volume 5. Appendix J - Contractor data package procurement and contracting /PC/ Final report

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    Contractor data package for administration of procurement and contracting of Voyager spacecraft system

    Radiative Corrections to K^0_{l3} Decays

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    We calculate the long-distance radiative corrections \delta^e_{LD} and \delta^{\mu}_{LD} to the K^0 -> \pi^- e^+ \nu_e and the K^0 -> pi^- \mu^+ \nu_{\mu} decay rates. This analysis includes contributions to the long-distance radiative corrections from outside the kinematically-allowed three-body Dalitz region and tests the sensitivity of the radiative corrections to the hadronic K-pi form factors. A program, KLOR, was written to numerically evaluate the radiative corrections and to generate Monte Carlo events for experimental acceptance studies. The K^0_{e3} and the K^0_{\mu 3} long-distance radiative correction parameters are determined to be (1.3 +/- 0.3)% and (1.9 +/- 0.3)%, respectively. We also present predictions for the fraction of radiative K^0_{l3} events satisfying various requirements on final-state photon kinematics.Comment: Accepted in Annals of Physics; 16 pages, 8 figures; v3 contains minor text change

    Building Trust and Visibility Through Community-Based Participatory Research at Rural Minority-Serving Institutions

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    Universities and colleges are producers of knowledge and play an important role in shaping culture, policy, political agendas, and in many ways, the flow of resources to communities. To increase the potential for those living in rural communities, as well as the vibrancy of these communities, researchers can and should center rural voices, ground the production of knowledge in these voices, and address power imbalances in research and practice. Minority Serving Institutions (MSIs) play a crucial role in this strategy for empowering rural communities. In our latest research brief, the authors explore how rural MSIs and approaches to community based participatory research can be used to better understand MSIs' nature and practices

    Enhanced Integrin α4β1-Mediated Adhesion Contributes to a Mobilization Defect of Endothelial Progenitor Cells in Diabetes.

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    Diabetes is associated with a deficit of circulating endothelial progenitor cells (EPCs), which has been attributed to their defective mobilization from the bone marrow. The basis for this mobilization defect is not completely understood, and we sought to determine if hyperglycemic conditions enhanced EPC adhesion. We found that culturing EPCs in high glucose media increased adhesion to bone marrow stromal cells. This enhanced adhesion was associated with decreased expression of protein kinase A regulatory subunit 1β (PRKAR1β), activation of protein kinase A (PKA), and phosphorylation of α4-integrin on serine 988. This potentiated adhesion was reversed by treatment with a PKA inhibitor, overexpression of PRKAR1β, or expression of a phosphorylation-defective α4-integrin variant (α4[S988A]). Using a model of type 1 diabetes, we showed that α4(S988A)-expressing mice have more circulating EPCs than their wild-type counterparts. Moreover, diabetic α4(S988A) mice demonstrate enhanced revascularization after hind limb ischemia. Thus, we have identified a novel signaling mechanism activating PKA in diabetes (downregulation of an inhibitory regulatory subunit) that leads to deficits of circulating EPCs and impaired vascular repair, which could be reversed by α4-integrin mutation

    Superconducting properties of ultrathin Bi2Sr2CaCu2O8+x single crystals

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    We use Ar-ion milling to thin Bi2212 single crystals down to a few nanometers or one-to-two (CuO2)2 layers. With decreasing the thickness, superconducting transition temperature gradually decreases to zero and the in-plane resistivity increases to large values indicating the existence of a superconductor-insulator transition in ultrathin Bi2212 single crystals.Comment: 17 pages, 6 figures, to appear in J. Appl. Phys. 98(3) 200

    Updating DL-Lite ontologies through first-order queries

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    In this paper we study instance-level update in DL-LiteA, the description logic underlying the OWL 2 QL standard. In particular we focus on formula-based approaches to ABox insertion and deletion. We show that DL-LiteA, which is well-known for enjoying first-order rewritability of query answering, enjoys a first-order rewritability property also for updates. That is, every update can be reformulated into a set of insertion and deletion instructions computable through a nonrecursive datalog program. Such a program is readily translatable into a first-order query over the ABox considered as a database, and hence into SQL. By exploiting this result, we implement an update component for DLLiteA-based systems and perform some experiments showing that the approach works in practice.Peer ReviewedPostprint (author's final draft
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