9 research outputs found

    Interrogating Plant Cell Culture Library for Novel Antimicrobial Agents

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    The Plant Cell Culture Library (PCCL) at UMass Amherst contains more than 2,200 live plant cell cultures, representing diverse plant species from around the world. The availability of this collection offers a rich resource for us to discover bioactive phytochemicals and uncover their mechanisms of action. Using data-mining surveys of bioactive plant extracts, I have organized subsets of PCCL cell lines that are likely to possess antifungal, antibacterial, antiviral, anthelmintic, anti-trypanosomal, or anticancer properties, which prove to be useful when deciding which species to screen first against a specific pathogen. Another distinct advantage of using the live plant cells in this research is the ability to stimulate the biosynthesis of pathogen-specific phytochemicals upon simulation of an attack (elicitation) by the microorganism in question. This could be accomplished by pathogen homogenates or plant hormones responsible for mounting defenses to infection. Over the past six months, I have been working to optimize elicitation, lysis, and extraction conditions for obtaining high-throughput screening materials to be used against variable pathogens. Equipped with crude extracts from appropriately elicited cells, I am collaborating with a multidisciplinary team of UMass scientists to develop and implement high-throughput screening protocols for profiling a large number of plant-derived materials against various pathogens. Recently, I have screened a small pool (40) of extracts derived from cell lines with predicted anti-fungal properties against the highly resistant strain of fungus Fusarium oxysporum, one of the causal agents of an opportunistic infection often seen in immunocompromised patients known as fusariosis. Gratifyingly, I have found several plant species that produced specialized metabolites with better antifungal activity than the leading antibiotic against F. oxysporum, Amphotericin B, validating this line of antimicrobial research. We are also actively reaching out to other academic labs partners to form partnerships in diverse antimicrobial research venues

    Theia: Faint objects in motion or the new astrometry frontier

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    In the context of the ESA M5 (medium mission) call we proposed a new satellite mission, Theia, based on relative astrometry and extreme precision to study the motion of very faint objects in the Universe. Theia is primarily designed to study the local dark matter properties, the existence of Earth-like exoplanets in our nearest star systems and the physics of compact objects. Furthermore, about 15 %\% of the mission time was dedicated to an open observatory for the wider community to propose complementary science cases. With its unique metrology system and "point and stare" strategy, Theia's precision would have reached the sub micro-arcsecond level. This is about 1000 times better than ESA/Gaia's accuracy for the brightest objects and represents a factor 10-30 improvement for the faintest stars (depending on the exact observational program). In the version submitted to ESA, we proposed an optical (350-1000nm) on-axis TMA telescope. Due to ESA Technology readiness level, the camera's focal plane would have been made of CCD detectors but we anticipated an upgrade with CMOS detectors. Photometric measurements would have been performed during slew time and stabilisation phases needed for reaching the required astrometric precision

    Gaia DR2 sources in GC and dSph

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    VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'Gaia Data Release 2. Kinematics of globular clusters and dwarf galaxies around the Milky Way' (bibcode: 2018A&A...616A..12G

    Gaia DR2. Variable stars in CMD

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    VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'Gaia Data Release 2. Variable stars in the colour-absolute magnitude diagram.' (bibcode: 2019A&A...623A.110G

    46 open clusters GaiaDR2 HR diagrams

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    VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'Gaia Data Release 2: Observational Hertzsprung-Russell diagrams.' (bibcode: 2018A&A...616A..10G

    Theia: Faint objects in motion or the new astrometry frontier

    No full text
    In the context of the ESA M5 (medium mission) call we proposed a new satellite mission, Theia, based on relative astrometry and extreme precision to study the motion of very faint objects in the Universe. Theia is primarily designed to study the local dark matter properties, the existence of Earth-like exoplanets in our nearest star systems and the physics of compact objects. Furthermore, about 15 %\% of the mission time was dedicated to an open observatory for the wider community to propose complementary science cases. With its unique metrology system and "point and stare" strategy, Theia's precision would have reached the sub micro-arcsecond level. This is about 1000 times better than ESA/Gaia's accuracy for the brightest objects and represents a factor 10-30 improvement for the faintest stars (depending on the exact observational program). In the version submitted to ESA, we proposed an optical (350-1000nm) on-axis TMA telescope. Due to ESA Technology readiness level, the camera's focal plane would have been made of CCD detectors but we anticipated an upgrade with CMOS detectors. Photometric measurements would have been performed during slew time and stabilisation phases needed for reaching the required astrometric precision
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