39 research outputs found

    Incorporating Redundant Systems to Capture the Kentucky Money Shot

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    The Kentucky Eclipse Ballooning Project began in early 2015 when students and faculty from The University of Kentucky attended the NASA Marshall Space Flight Center BalloonSat Workshop in Huntsville, Alabama. These students then accelerated after the Eclipse Ballooning Project Workshop hosted in Bozeman, Montana where they built and learned systems designed by Montana Space Grant. In 2015-2016, the students began a sequence of 10 balloon launches in preparation for the total solar eclipse on August 21, 2017. In the early stages of this project, University of Kentucky students set the goal to capture footage of a separate high-altitude weather balloon in front of the solar eclipse, an image dubbed “The Kentucky Money Shot”. After establishing that goal, students began working on approaches and designs to capture this picture with one overarching theme: redundancy. Every aspect of the project from the number of balloons and imaging systems to tracking systems and launch procedures were designed with redundant aspects and through collaboration among the payload, ground station, launch, and mission control teams. The short time window of eclipse totality, 2 minutes 28 seconds, motivated design iterations throughout the progressive practice launches and ground tests including launching two balloons simultaneously, streaming and storing footage of the flight from multiple cameras, and using SPOT Trackers and Iridium systems as multiple tracking approaches. All of these practices and tests led to flying the final redundant designs on August 21st, 2017 to successfully capture “The Kentucky Money Shot”

    Scantegrity II Municipal Election at Takoma Park: The First E2E Binding Governmental Election with Ballot Privacy

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    On November 3, 2009, voters in Takoma Park, Maryland, cast ballots for the mayor and city council members using the Scantegrity II voting system—the first time any end-to-end (E2E) voting system with ballot privacy has been used in a binding governmental election. This case study describes the various efforts that went into the election—including the improved design and implementation of the voting system, streamlined procedures, agreements with the city, and assessments of the experiences of voters and poll workers. The election, with 1728 voters from six wards, involved paper ballots with invisible-ink confirmation codes, instant-runoff voting with write-ins, early and absentee (mail-in) voting, dual-language ballots, provisional ballots, privacy sleeves, any-which-way scanning with parallel conventional desktop scanners, end-to-end verifiability based on optional web-based voter verification of votes cast, a full hand recount, thresholded authorities, three independent outside auditors, fully-disclosed software, and exit surveys for voters and pollworkers. Despite some glitches, the use of Scantegrity II was a success, demonstrating that E2E cryptographic voting systems can be effectively used and accepted by the general public.United States. Dept. of Defense (IASP grant H98230-08-1-0334)United States. Dept. of Defense (IASP grant H98230-09-1-0404)National Science Foundation (U.S.) (Grant no. CNS 0831149

    Scantegrity Responds to Rice Study on Usability of the Scantegrity II Voting System

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    This note is a response to, and critique of, recent work by Acemyan, Kortum, Bryne, and Wallach regarding the usability of end-to-end verifiable voting systems, and in particular, to their analysis of the usability of the Scantegrity II voting system. Their work is given in a JETS paper [Ace14] and was presented at EVT/WOTE 2014; it was also described in an associated press release [Rut14]. We find that their study lacked an appropriate control voting system with which to compare effectiveness, and thus their conclusions regarding Scantegrity II are unsupported by the evidence they present. Furthermore, their conclusions are contradicted by the successful deployment experiences of Scantegrity II at Takoma Park

    Age- and sex-dependent role of osteocytic pannexin1 on bone and muscle mass and strength

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    Pannexins (Panxs), glycoproteins that oligomerize to form hemichannels on the cell membrane, are topologically similar to connexins, but do not form cell-to-cell gap junction channels. There are 3 members of the family, 1-3, with Panx1 being the most abundant. All Panxs are expressed in bone, but their role in bone cell biology is not completely understood. We now report that osteocytic Panx1 deletion (Panx1Δot) alters bone mass and strength in female mice. Bone mineral density after reaching skeletal maturity is higher in female Panx1Δot mice than in control Panx1fl/fl mice. Further, osteocytic Panx1 deletion partially prevented aging effects on cortical bone structure and mechanical properties. Young 4-month-old female Panx1Δot mice exhibited increased lean body mass, even though pannexin levels in skeletal muscle were not affected; whereas no difference in lean body mass was detected in male mice. Furthermore, female Panx1-deficient mice exhibited increased muscle mass without changes in strength, whereas Panx1Δot males showed unchanged muscle mass and decreased in vivo maximum plantarflexion torque, indicating reduced muscle strength. Our results suggest that osteocytic Panx1 deletion increases bone mass in young and old female mice and muscle mass in young female mice, but has deleterious effects on muscle strength only in males

    Osteocytic miR21 deficiency improves bone strength independent of sex despite having sex divergent effects on osteocyte viability and bone turnover

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    Osteocytes play a critical role in mediating cell–cell communication and regulating bone homeostasis, and osteocyte apoptosis is associated with increased bone resorption. miR21, an oncogenic microRNA, regulates bone metabolism by acting directly on osteoblasts and osteoclasts, but its role in osteocytes is not clear. Here, we show that osteocytic miR21 deletion has sex‐divergent effects in bone. In females, miR21 deletion reduces osteocyte viability, but suppresses bone turnover. Conversely, in males, miR21 deletion increases osteocyte viability, but stimulates bone turnover and enhances bone structure. Further, miR21 deletion differentially alters osteocyte cytokine production in the two sexes. Interestingly, despite these changes, miR21 deletion increases bone mechanical properties in both sexes, albeit to a greater extent in males. Collectively, our findings suggest that miR21 exerts both sex‐divergent and sex‐equivalent roles in osteocytes, regulating osteocyte viability and altering bone metabolism through paracrine actions on osteoblasts and osteoclasts differentially in males vs females, whereas, influencing bone mechanical properties independent of sex

    Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

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    Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant

    Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes

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    Background The first epidemic wave of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over one-third of care homes reported an outbreak, while there was limited testing of hospital patients discharged to care homes. Aim To investigate patients discharged from hospitals as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave. Methods A clinical review was performed for all patients discharges from hospitals to care homes from 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease 2019 (COVID-19) test history, clinical assessment at discharge, whole-genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis using Cluster Investigation and Virus Epidemiological Tool software. Patient timelines were obtained using electronic hospital records. Findings In total, 787 patients discharged from hospitals to care homes were identified. Of these, 776 (99%) were ruled out for subsequent introduction of SARS-CoV-2 into care homes. However, for 10 episodes, the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data were available. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission, leading to 10 positive cases in their care home. Conclusion The majority of patients discharged from hospitals were ruled out for introduction of SARS-CoV-2 into care homes, highlighting the importance of screening all new admissions when faced with a novel emerging virus and no available vaccine

    SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

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    Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

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    Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity

    Get PDF
    Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
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