74 research outputs found

    Trials & Tribulations Encountered During the Development & Teaching of a Dual-Delivery Format Research Methods Course

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    This paper focuses on developmental and pedagogical/sociological issues related to a doctoral level research methodology course. This course is delivered in two formats, resident (face-to-face) and distance (web-based on Blackboard). Pedagogical, sociological, course development, course delivery, issues and challenges for both formats are discussed. An annotated bibliography is also included

    Genetic engineering of vaccine manufacturing cell lines enhances poliovirus and enterovirus 71 production

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    Vaccine manufacturing costs and production limitations represent two fundamental challenges facing researchers, public health officials and vaccine manufacturers committed to global health solutions. To address these issues, we have investigated whether the cell lines employed by vaccine manufacturers can be engineered to enhance vaccine virus production. As a first step in a proof-of-principle study, a genome-wide RNA Interference (RNAi) screen was conducted to identify host gene modulation events that increased Sabin 2 poliovirus (PV) replication. Primary screen hits were validated in a Vero vaccine manufacturing cell line using both attenuated and wild type poliovirus strains. This approach identified multiple single and dual gene knockdown events that increased PV titers \u3e20-fold and \u3e50-fold, respectively. Top candidate genes did not affect virus antigenicity, cell viability, or cell doubling times. Moreover, CRISPR/Cas9-mediated knockout (KO) of the top three targets created stable cell substrates with improved viral vaccine strain production. Please click Additional Files below to see the full abstract

    New verified nonindigenous amphibians and reptiles in Florida, 1976 through 2015, with a summary of over 152 years of introductions

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    More nonindigenous species occur in Florida, USA, than any other region worldwide and may threaten many of Florida’s natural resources. The frequency of new reports mandates the need for regular updates. Herein, we use photographic and specimen vouchers in addition to literature records to provide updated information on verified nonindigenous amphibians and reptiles in Florida. Between our most recent summary in 2012 and the end of 2015, 38 additional species are known to have been intercepted (n = 2) or introduced (n = 36). We also update the invasion stage of seven species previously reported from Florida and report that five additional taxa are now established. In total, 191 independent known introductions of 180 herpetofaunal taxa led to the establishment of 63 taxa. This suggests that one in three introduced herpetofaunal species becomes established in Florida. The pet trade represents the most  common introduction pathway among these species animal importer in Hollywood, Broward County, is the probable source for introduction of a quarter of all herpetofauna introduced to Florida

    New Verified Nonindigenous Amphibians and Reptiles in Florida through 2015, with a Summary of More Than 152 Years of Introductions.

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    More nonindigenous species occur in Florida, USA, than any other region worldwide and may threaten many of Florida’s natural resources. The frequency of new reports mandates the need for regular updates. Herein, we use photographic and specimen vouchers in addition to literature records to provide updated information on verified nonindigenous amphibians and reptiles in Florida. Between our most recent summary in 2012 and the end of 2015, 38 additional species are known to have been intercepted (n = 2) or introduced (n = 36). We also update the invasion stage of seven species previously reported from Florida and report that five additional taxa are now established. In total, 191 independent known introductions of 180 herpetofaunal taxa led to the establishment of 63 taxa. This suggests that one in three introduced herpetofaunal species becomes established in Florida. The pet trade represents the most common introduction pathway among these species and a single animal importer in Hollywood, Broward County, is the probable source for introduction of a quarter of all herpetofauna introduced to Florida

    The Large UV/Optical/Infrared Surveyor (LUVOIR): Decadal Mission Concept Design Update

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    In preparation for the 2020 Astrophysics Decadal Survey, NASA has commissioned the study of four large mission concepts, including the Large Ultraviolet / Optical / Infrared (LUVOIR) Surveyor. The LUVOIR Science and Technology Definition Team (STDT) has identified a broad range of science objectives including the direct imaging and spectral characterization of habitable exoplanets around sun-like stars, the study of galaxy formation and evolution, the epoch of reionization, star and planet formation, and the remote sensing of Solar System bodies. NASAs Goddard Space Flight Center (GSFC) is providing the design and engineering support to develop executable and feasible mission concepts that are capable of the identified science objectives. We present an update on the first of two architectures being studied: a 15-meter-diameter segmented-aperture telescope with a suite of serviceable instruments operating over a range of wavelengths between 100 nm to 2.5 microns. Four instruments are being developed for this architecture: an optical / near-infrared coronagraph capable of 10(exp -10) contrast at inner working angles as small as 2 lambda/D; the LUVOIR UV Multi-object Spectrograph (LUMOS), which will provide low- and medium-resolution UV (100 400 nm) multi-object imaging spectroscopy in addition to far-UV imaging; the High Definition Imager (HDI), a high-resolution wide-field-of-view NUV-Optical-IR imager; and a UV spectro-polarimeter being contributed by Centre National dEtudes Spatiales (CNES). A fifth instrument, a multi-resolution optical-NIR spectrograph, is planned as part of a second architecture to be studied in late 2017

    N plus 3 Advanced Concept Studies for Supersonic Commercial Transport Aircraft Entering Service in the 2030-2035 Period

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    Boeing, with Pratt & Whitney, General Electric, Rolls-Royce, M4 Engineering, Wyle Laboratories and Georgia Institute of Technology, conducted a study of supersonic commercial aircraft concepts and enabling technologies for the year 2030-2035 timeframe. The work defined the market and environmental/regulatory conditions that could evolve by the 2030/35 time period, from which vehicle performance goals were derived. Relevant vehicle concepts and technologies are identified that are anticipated to meet these performance and environmental goals. A series of multidisciplinary analyses trade studies considering vehicle sizing, mission performance and environmental conformity determined the appropriate concepts. Combinations of enabling technologies and the required technology performance levels needed to meet the desired goals were identified. Several high priority technologies are described in detail, including roadmaps with risk assessments that outline objectives, key technology challenges, detailed tasks and schedules and demonstrations that need to be performed. A representative configuration is provided for reference purposes, along with associated performance estimates based on these key technologies

    The JWST Discovery of the Triply-imaged Type Ia "Supernova H0pe" and Observations of the Galaxy Cluster PLCK G165.7+67.0

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    A Type Ia supernova (SN) at z=1.78z=1.78 was discovered in James Webb Space Telescope Near Infrared Camera imaging of the galaxy cluster PLCK G165.7+67.0 (G165; z=0.35z = 0.35). The SN is situated 1.5-2kpc from its host galaxy Arc 2 and appears in three different locations as a result of gravitational lensing by G165. These data can yield a value for Hubble's constant using time delays from this multiply-imaged SN Ia that we call "SN H0pe." Over the entire field we identified 21 image multiplicities, confirmed five of them using Near-Infrared Spectrograph (NIRspec), and constructed a new lens model that gives a total mass within 600kpc of (2.6±0.3)×10142.6 \pm 0.3) \times 10^{14} M_{\odot}. The photometry uncovered a galaxy overdensity at Arc 2's redshift. NIRSpec confirmed six member galaxies, four of which surround Arc 2 with relative velocity \lesssim900 km s1^{-1} and projected physical extent \lesssim33 kpc. Arc 2 dominates the stellar mass ((5.0±0.1)×1011(5.0 \pm 0.1) \times 10^{11} M_{\odot}), which is a factor of ten higher than other members of this compact galaxy group. These other group members have specific star formation rates (sSFR) of 2-260Gyr1^{-1} derived from the Hα\alpha-line flux corrected for stellar absorption, dust extinction, and slit losses. Another group centered on the dusty star forming galaxy Arc 1 is at z=2.24z=2.24. The total SFR for the Arc 1 group (gtrsimgtrsim M_{\odot} yr1^{-1}) translates to a supernova rate of \sim1 SNe yr1^{-1}, suggesting that regular monitoring of this cluster may yield additional SNe.Comment: 27 pages, submitted to Ap

    Paper 1: The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies

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    The massive galaxy cluster El Gordo (z=0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope (JWST) Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the ``Prime Extragalactic Areas for Reionization and Lensing Science'' (``PEARLS'') program. PSF-matched photometry across Hubble Space Telescope (HST) and NIRCam filters supplies new photometric redshifts. A new light-traces-mass lens model based on 56 image multiplicities identifies the two mass peaks and yields a mass estimate within 500 kpc of ~(7.0 +/- 0.30) x 10^14 Msun. A search for substructure in the 140 cluster members with spectroscopic redshifts confirms the two main mass components. The southeastern mass peak that contains the BCG is more tightly bound than the northwestern one. The virial mass within 1.7 Mpc is (5.1 +/- 0.60) x 10^14 Msun, lower than the lensing mass. A significant transverse velocity component could mean the virial mass is underestimated. We contribute one new member to the previously known z=4.32 galaxy group. Intrinsic (delensed) positions of the five secure group members span a physical extent of ~60 kpc. Thirteen additional candidates selected by spectroscopic/photometric constraints are small and faint with a mean intrinsic luminosity ~2.2 mag fainter than L*. NIRCam imaging admits a fairly wide range of brightnesses and morphologies for the group members, suggesting a more diverse galaxy population in this galaxy overdensity.Comment: 24 pages, accepted by Ap
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