2,701 research outputs found

    The Real Time Display Builder (RTDB)

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    The Real Time Display Builder (RTDB) is a prototype interactive graphics tool that builds logic-driven displays. These displays reflect current system status, implement fault detection algorithms in real time, and incorporate the operational knowledge of experienced flight controllers. RTDB utilizes an object-oriented approach that integrates the display symbols with the underlying operational logic. This approach allows the user to specify the screen layout and the driving logic as the display is being built. RTDB is being developed under UNIX in C utilizing the MASSCOMP graphics environment with appropriate functional separation to ease portability to other graphics environments. RTDB grew from the need to develop customized real-time data-driven Space Shuttle systems displays. One display, using initial functionality of the tool, was operational during the orbit phase of STS-26 Discovery. RTDB is being used to produce subsequent displays for the Real Time Data System project currently under development within the Mission Operations Directorate at NASA/JSC. The features of the tool, its current state of development, and its applications are discussed

    pQuattro vectors allow one-step multigene metabolic engineering and auto-selection of quattrocistronic artificial mammalian operons

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    Based on internal ribosomal entry sites (IRES) of picornaviral origin we constructed a novel family of mammalian expression vectors. pQuattro vectors contain quattrocistronic artificial eukaryotic operons which link, in a single transcript, the simultaneous and coordinated as well as adjustable expression of up to three independent genes of interest to a terminal neomycin (neo) resistance marker. Due to the strict genetic linkage of the transgenes and the terminal selection marker, this genetic configuration enables, by the selection on neomycin, multigene metabolic engineering of mammalian cells in a single step (one-step metabolic engineering). Furthermore, selection on the terminal cistron of multicistronic expression units enforces cocistronic expression of all upstream encoded genes and maximises genetic integrity of the eukaryotic operon in stable mammalian cell lines, since clones harbouring damaged multicistronic expression units become neomycin-sensitive and are automatically counterselected (auto-selection). The modular set-up and the abundance of restriction sites in pQuattro vectors facilitate the movement of individual genes between multicistronic expression vectors and guarantees high compatibility with genetic elements of a wide variety of existing mammalian expression vector

    Land Grant Application- Bailey, Samuel (Lincoln)

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    Land grant application submitted to the Maine Land Office on behalf of Samuel Bailey for service in the Revolutionary War, by their widow Elenor.https://digitalmaine.com/revolutionary_war_me_land_office/1044/thumbnail.jp

    Engineered polyketides: Synergy between protein and host level engineering

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    Metabolic engineering efforts toward rewiring metabolism of cells to produce new compounds often require the utilization of non-native enzymatic machinery that is capable of producing a broad range of chemical functionalities. Polyketides encompass one of the largest classes of chemically diverse natural products. With thousands of known polyketides, modular polyketide synthases (PKSs) share a particularly attractive biosynthetic logic for generating chemical diversity. The engineering of modular PKSs could open access to the deliberate production of both existing and novel compounds. In this review, we discuss PKS engineering efforts applied at both the protein and cellular level for the generation of a diverse range of chemical structures, and we examine future applications of PKSs in the production of medicines, fuels and other industrially relevant chemicals

    Planet Hunters. VI: An Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data

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    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI-351, making it the only seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting 1\lesssim 1 AU from their host star. A Hill stability test and an orbital integration of the system shows that the system is stable. Furthermore, we significantly add to the population of long period transiting planets; periods range from 124-904 days, eight of them more than one Earth year long. Seven of these 14 candidates reside in their host star's habitable zone.Comment: 27 pages, 6 figures, 5 tables, Accepted to AJ (in press) (updated title from original astro-ph submission
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