5 research outputs found
Understanding the context of providing HIV prevention and treatment in Papua New Guinea
The HIV epidemic in Papua New Guinea is now described as a generalized epidemic; that is, more than 1% of people aged 15 to 49 years are infected with HIV. The individual behavior of people is not the single most important factor that places them at risk of infection and drives the spread of the epidemic. Rather, a diverse range of factors—biological, sociocultural, and political—makes people vulnerable to infection and dictates their access to care and treatment services. This article examines these biological, sociocultural, and political influences on the HIV epidemic and on prevention and treatment strategies in Papua New Guinea
Simultaneous Observation of an Auroral Dawn Storm with the Hubble Space Telescope and Juno
On July 13, 2016, the Hubble Space Telescope observed the onset of a dawn storm in Jupiter's northern ultraviolet aurora, while the NASA Juno spacecraft simultaneously traversed the dawnside outer magnetosphere. This represents the first concurrent auroral and in situ magnetospheric observations of the onset of a dawn storm at Jupiter. Mapping the auroral emission to the magnetosphere reveals the dawn storm corresponds to a source region at ∼60 Jupiter radii, and the eastward edge propagates toward local noon at speeds exceeding corotation. Particle observations from Jovian Auroral Distributions Experiment (JADE) and Jupiter Energetic particle Detector Instrument (JEDI) reveal the presence of enhanced hot plasma density in the outer magnetosphere during this interval, and pitch angle distributions measured with JEDI reveal pronounced field-aligned proton and heavy ion motion. Juno magnetometer (MAG) signatures reveal a reversal in the azimuthal magnetic field at the time of storm onset, suggesting acceleration of the hot plasma population above typical sub-corotational speeds. JEDI also detects a region of energetic particles which persists throughout the day following the storm, a feature which is not observed during subsequent perijoves. We interpret this dawn storm as the result of reconnection at earlier local times, possibly associated with a disruption of the azimuthal magnetodisk current
Neptune odyssey: A flagship concept for the exploration of the neptune-triton system
The Neptune Odyssey mission concept is a Flagship-class orbiter and atmospheric probe to the Neptune-Triton system. This bold mission of exploration would orbit an ice-giant planet to study the planet, its rings, small satellites, space environment, and the planet-sized moon Triton. Triton is a captured dwarf planet from the Kuiper Belt, twin of Pluto, and likely ocean world. Odyssey addresses Neptune system-level science, with equal priorities placed on Neptune, its rings, moons, space environment, and Triton. Between Uranus and Neptune, the latter is unique in providing simultaneous access to both an ice giant and a Kuiper Belt dwarf planet. The spacecraft - in a class equivalent to the NASA/ESA/ASI Cassini spacecraft - would launch by 2031 on a Space Launch System or equivalent launch vehicle and utilize a Jupiter gravity assist for a 12 yr cruise to Neptune and a 4 yr prime orbital mission; alternatively a launch after 2031 would have a 16 yr direct-to-Neptune cruise phase. Our solution provides annual launch opportunities and allows for an easy upgrade to the shorter (12 yr) cruise. Odyssey would orbit Neptune retrograde (prograde with respect to Triton), using the moon's gravity to shape the orbital tour and allow coverage of Triton, Neptune, and the space environment. The atmospheric entry probe would descend in ~37 minutes to the 10 bar pressure level in Neptune's atmosphere just before Odyssey's orbit-insertion engine burn. Odyssey's mission would end by conducting a Cassini-like "Grand Finale,"passing inside the rings and ultimately taking a final great plunge into Neptune's atmosphere
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Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity
Analysis of the spread and frequency of SARS-CoV-2 D614G in the United Kingdom suggests a selective advantage for this strain that is associated with higher viral loads in younger patients but not higher COVID-19 clinical severity or mortality
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Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study
Background: The SARS-CoV-2 variant B.1.1.7 was first identified in December, 2020, in England. We aimed to investigate whether increases in the proportion of infections with this variant are associated with differences in symptoms or disease course, reinfection rates, or transmissibility. Methods: We did an ecological study to examine the association between the regional proportion of infections with the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility. Data on types and duration of symptoms were obtained from longitudinal reports from users of the COVID Symptom Study app who reported a positive test for COVID-19 between Sept 28 and Dec 27, 2020 (during which the prevalence of B.1.1.7 increased most notably in parts of the UK). From this dataset, we also estimated the frequency of possible reinfection, defined as the presence of two reported positive tests separated by more than 90 days with a period of reporting no symptoms for more than 7 days before the second positive test. The proportion of SARS-CoV-2 infections with the B.1.1.7 variant across the UK was estimated with use of genomic data from the COVID-19 Genomics UK Consortium and data from Public Health England on spike-gene target failure (a non-specific indicator of the B.1.1.7 variant) in community cases in England. We used linear regression to examine the association between reported symptoms and proportion of B.1.1.7. We assessed the Spearman correlation between the proportion of B.1.1.7 cases and number of reinfections over time, and between the number of positive tests and reinfections. We estimated incidence for B.1.1.7 and previous variants, and compared the effective reproduction number, Rt, for the two incidence estimates. Findings: From Sept 28 to Dec 27, 2020, positive COVID-19 tests were reported by 36 920 COVID Symptom Study app users whose region was known and who reported as healthy on app sign-up. We found no changes in reported symptoms or disease duration associated with B.1.1.7. For the same period, possible reinfections were identified in 249 (0·7% [95% CI 0·6–0·8]) of 36 509 app users who reported a positive swab test before Oct 1, 2020, but there was no evidence that the frequency of reinfections was higher for the B.1.1.7 variant than for pre-existing variants. Reinfection occurrences were more positively correlated with the overall regional rise in cases (Spearman correlation 0·56–0·69 for South East, London, and East of England) than with the regional increase in the proportion of infections with the B.1.1.7 variant (Spearman correlation 0·38–0·56 in the same regions), suggesting B.1.1.7 does not substantially alter the risk of reinfection. We found a multiplicative increase in the Rt of B.1.1.7 by a factor of 1·35 (95% CI 1·02–1·69) relative to pre-existing variants. However, Rt fell below 1 during regional and national lockdowns, even in regions with high proportions of infections with the B.1.1.7 variant. Interpretation: The lack of change in symptoms identified in this study indicates that existing testing and surveillance infrastructure do not need to change specifically for the B.1.1.7 variant. In addition, given that there was no apparent increase in the reinfection rate, vaccines are likely to remain effective against the B.1.1.7 variant. Funding: Zoe Global, Department of Health (UK), Wellcome Trust, Engineering and Physical Sciences Research Council (UK), National Institute for Health Research (UK), Medical Research Council (UK), Alzheimer's Society.</p