3,703 research outputs found

    USL/DBMS NASA/PC R and D project system testing standards

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    A set of system testing standards to be used in the development of all C software within the NASA/PC Research and Development Project is established. Testing will be considered in two phases: the program testing phase and the system testing phase. The objective of these standards is to provide guidelines for the planning and conduct of program and software system testing

    Synthesis of a Molecular Charm Bracelet via Click Cyclization and Olefin Metathesis Clipping

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    We describe the synthesis of a polycatenated cyclic polymer, a structure that resembles a molecular charm bracelet. Ruthenium-catalyzed ring-opening metathesis polymerization of an aminocontaining cyclic olefin monomer in the presence of a chain transfer agent generated an α,ω-diazide functionalized polyamine. Cyclization of the resulting linear polyamine using pseudo-high-dilution coppercatalyzed click cyclization produced a cyclic polymer in 19% yield. The click reaction was then further employed to remove linear contaminants from the cyclic polymer using azide- and alkyne-functionalized scavenging resins, and the purified cyclic polymer product was characterized by gel permeation chromatography, ^1H NMR spectroscopy, and IR spectroscopy. Polymer hydrogenation and conversion to the corresponding polyammonium species enabled coordination and interlocking of diolefin polyether fragments around the cyclic polymer backbone using ruthenium-catalyzed ring-closing olefin metathesis to afford a molecular charm bracelet structure. This charm bracelet complex was characterized by ^1H NMR spectroscopy, and the catenated nature of the small rings was confirmed using two-dimensional diffusion-ordered NMR spectroscopy

    T-cadherin deficiency increases vascular vulnerability in T2DM through impaired NO bioactivity.

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    BACKGROUND: Endothelial dysfunction plays a critical role in the development of type 2 diabetes (T2DM). T-cadherin (T-cad) has gained recognition as a regulator of endothelial cell (EC) function. The present study examined whether T-cad deficiency increases vascular vulnerability in T2DM. METHODS: Vascular segments were isolated from WT or T-cad knockout mice. Endothelial function, total NO accumulation, and the expression of T-cad related proteins were determined. RESULTS: Ach and acidified NaNO2 induced similar vasorelaxation in WT groups. T-cad KO mice exhibited normal response to acidified NaNO2, but manifested markedly reduced response to Ach. NO accumulation was also decreased in T-cad KO group. T-cad expression was reduced in WT mice fed 8 weeks of high fat diet (HFD). Furthermore, exacerbated reduction of vasorelaxation was observed in T-cad KO mice fed 8 weeks of HFD. CONCLUSIONS: In the current study, we provide the first in vivo evidence that T-cadherin deficiency causes endothelial dysfunction in T2DM vascular segments, suggesting the involvement of T-cad deficiency in T2DM pathogenesis

    Many Rooms: Mixed Use Reimagining Church Redevelopments in Vancouver

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    In recent decades, Christian congregations in Canada have seen a significant decrease in affiliation and attendance. As congregations dwindled, many of the aging church buildings across the country have been sold, converted, or demolished. This has resulted in the loss of community-serving spaces in both rural and urban communities across the country. While existing research focuses on the adaptive reuse of churches, the recently emerging phenomenon of the mixed-use church building brings a new opportunity to reconsider how church buildings may evolve in response to the changing needs of contemporary society. A mixed-use church building is a typology which integrates the religious and communal functions of a church within the fabric of a multi-story residential building. Redeveloping presents congregations with the opportunity to continue their ministry in the community, while preserving or expanding their spatial capacity. In addition, these projects also allow congregations to provide new amenities in the form of below-market housing. The research examines the contextual conditions which lead to the mixed-use option, and critically evaluates two recently completed case studies in terms of their architectural qualities. The thesis is an experimental design proposal of this typology in the city of Vancouver, which explores the architectural opportunities in combining religious, public, and residential functions. Based on the diverse range of ways that places of worship are utilized, as well as the demand for community serving spaces, the thesis proposes three public rooms set within a residential fabric: a hall, a theatre, and a chapel. Each explores a different relationship between sacred space in the urban context, one that opens onto the street, one below the ground, and one open to the sky, respectively. In doing so, the thesis explores how the mixed-use church building can create spaces which serve both church congregations, and the city at large

    New Insight into Metformin Mechanism of Action and Clinical Application

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    Metformin is the first-line medication for Type 2 diabetes (T2D) treatment, and it is the only US FDA approved oral antidiabetic medication for pediatric patients with T2D 10 years and older. Metformin is also used to treat polycystic ovary syndrome (PCOS), another condition with underlying insulin resistance. The clinical applications of metformin are continuing to expand into other fields including cancer, aging, cardiovascular diseases, and neurodegenerative diseases. Metformin modulates multiple biological pathways. Its novel properties and effects continue to evolve; however, its molecular mechanism of action remains incompletely understood. In this chapter, we focus on the recent translational research and clinical data on the molecular action of metformin and the evidence linking the effects of metformin on insulin resistance, prediabetes, diabetes, aging, cancer, PCOS, cardiovascular diseases, and neurodegenerative diseases

    Assessing the Relevancy of National Culture in Predicting the Efficacy of Constraints in the Information Systems Consulting Domain

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    Opportunism is present in professional services and, as a result, organizations adopt mechanisms to constrain it. Despite the work on constraining opportunistic consultants, researchers have generally ignored the potential impact of national culture on the efficacy of constraint mechanisms. Using the theory of relationship constraints (TRC), this study examines the effectiveness of different constraint mechanisms for information systems (IS) consultants in the United States and China based on different levels of information asymmetry, tacit and explicit knowledge. While we found support in both cultures for the salience of these dimensions, we also found important distinctions for the effectiveness of different constraints between the cultures. Legal constraints are more effective in China while social constraints are more effective in the United States. While TRC is relevant in both cultures, national culture moderates the effectiveness of various constraint mechanisms and highlights the need for additional study
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