33 research outputs found

    Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

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    On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 ±\pm 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 ±\pm 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.Comment: Accepted by Natur

    Cytokine-associated neutrophil extracellular traps and antinuclear antibodies in Plasmodium falciparum infected children under six years of age

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    <p>Abstract</p> <p>Background</p> <p>In <it>Plasmodium falciparum</it>-infected children, the relationships between blood cell histopathology, blood plasma components, development of immunocompetence and disease severity remain poorly understood. Blood from Nigerian children with uncomplicated malaria was analysed to gain insight into these relationships. This investigation presents evidence for circulating neutrophil extracellular traps (NETs) and antinuclear IgG antibodies (ANA). The presence of NETs and ANA to double-stranded DNA along with the cytokine profiles found suggests autoimmune mechanisms that could produce pathogenesis in children, but immunoprotection in adults.</p> <p>Methods</p> <p>Peripheral blood smear slides and blood samples obtained from 21 Nigerian children under six years of age, presenting with uncomplicated malaria before and seven days after initiation of sulphadoxine-pyrimethamine (SP) treatment were analysed. The slides were stained with Giemsa and with DAPI. Levels of the pro-inflammatory cytokines IFN-γ, IL-2, TNF, CRP, and IL-6, select anti-inflammatory cytokines TGF-β and IL-10, and ANA were determined by immunoassay.</p> <p>Results</p> <p>The children exhibited circulating NETs with adherent parasites and erythrocytes, elevated ANA levels, a Th2 dominated cytokine profile, and left-shifted leukocyte differential counts. Nonspecific ANA levels were significant in 86% of the children pretreatment and in 100% of the children seven days after SP treatment, but in only 33% of age-matched control samples collected during the season of low parasite transmission. Levels of ANA specific for dsDNA were significant in 81% of the children both pre-treatment and post treatment.</p> <p>Conclusion</p> <p>The results of this investigation suggest that NET formation and ANA to dsDNA may induce pathology in falciparum-infected children, but activate a protective mechanism against falciparum malaria in adults. The significance of in vivo circulating chromatin in NETs and dsDNA ANA as a causative factor in the hyporesponsiveness of CpG oligonucleotide-based malaria vaccines is discussed.</p

    Health-Related Quality of Life for Persons Affected by Leber's Optic Neuropathy

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    Leber's hereditary optic neuropathy (LHON) is a maternally inherited eye disease that produces varying levels of visual impairment usually in the second or third decade of life. Research has focused on the genetics of the mitrochondrial mutations that underlie the disease, however little attention has been paid to the human costs exacted by LHON

    Gay Community Periodic Survey: Queensland 2017

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    The Queensland Community Periodic Survey is a cross-sectional survey of gay and homosexually active men recruited at a range of gay community sites around Queensland and online. The major aim of the survey is to provide data on sexual, drug use and testing practices related to the transmission of HIV and other sexually transmissible infections (STIs) among gay men. The most recent survey, the nineteenth in Queensland, was conducted in September-October 2017 to coincide with Brisbane Pride and Cairns Tropical Pride

    Gay Community Periodic Survey: Queensland 2017

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    The Queensland Community Periodic Survey is a cross-sectional survey of gay and homosexually active men recruited at a range of gay community sites around Queensland and online. From its start in 1997, the project has been funded by the Queensland Department of Health. The major aim of the survey is to provide data on sexual, drug use and testing practices related to the transmission of HIV and other sexually transmissible infections (STIs) among gay men. The data presented in this report are from the period 2013 to 2017

    Sea trials

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    A set of trials in an uncontrolled ocean environment that build confidence in the functionality, maintenance, operation and performance of the device and its ability to survive extreme conditions
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