290 research outputs found

    The crucial role of HST during the NASA Juno mission: a "Juno initiative"

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    In 2016, the NASA Juno spacecraft will initiate its one-year mission around Jupiter and become the first probe to explore the polar regions of Jupiter. The HST UV instruments (STIS and ACS) can greatly contribute to the success of the Juno mission by providing key complementary views of Jupiter's UV aurora from Earth orbit. Juno carries an ultraviolet Spectrograph (UVS) and an infrared spectral mapper (JIRAM) that will obtain high-resolution spectral images providing the auroral counterpart to Juno's in situ particles and fields measurements with the plasma JADE and JEDI particle detectors. The Juno mission will be the first opportunity to measure simultaneously the energetic particles at high latitude and the auroral emissions they produce. Following programmatic and technical limitations, the amount of UVS data transmitted to Earth will be severely restricted. Therefore, it is of extreme importance that HST captures as much additional information as possible on Jupiter's UV aurora during the one-year life of the Juno mission. This white paper is a plea for a "Juno initiative" that will ensure that a sufficient number of orbits is allocated to this unique solar system mission.Comment: Paper submitted to the Space Telescope Science Institute in response to the call for HST White Papers for Hubble's 2020 Visio

    The Grizzly, November 18, 1988

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    Booze Ban - No Bomb - But No New Booze News • Hess Awarded Honorary Chair • Talent Show Dazzles Ursinus Community • Letters: Alumnus Voices Drug Concerns; Stuff it in Your Socks, Mr. Bill • Escape with Chiapparone • Meehan, U.C. Spoil Dickinson\u27s Party • Pack Takes 3rd; O\u27Donohue Makes Nationals • Matters Fare Well at LaSalle Tourney • Circle Up with Circle K • Hoopsters Open with Cautious Optimismhttps://digitalcommons.ursinus.edu/grizzlynews/1224/thumbnail.jp

    The Jovian ionospheric conductivity derived from a broadband precipitated electron distribution

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    The Pedersen ionospheric conductivity and conductance at Jupiter are computed assuming a broadband precipitating-electron flux and compared to values obtained when assuming a mono-energetic precipitating-electron flux. Among other results, it is found that the ratio between the broadband and the mono-energetic conductances depends on the electron mean energy of the precipitating-electron population. For a mono-energetic distribution, an optimal energy exists, around 30-40 keV, for which the conductance arising from the precipitation is maximal. If the mean electron energy is well below this optimal energy, the conductance calculated for a broadband distribution is enhanced compared to the mono-energetic case because part of the electron energy distribution reaches this optimal level. The conductance is also underestimated for a mono-energetic electron precipitation well above the optimal value. The opposite trend is observed around the optimal energy as most of the electrons of the broadband distribution have either lower or higher energies, while all electrons of the mono-energetic distribution have an energy close to the optimum

    SIMULTANEOUS OBSERVATIONS OF THE SATURNIAN AURORA AND POLAR HAZE WITH THE HST/FOC

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    peer reviewedNear simultaneous observations of the Saturnian H-2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the post-COSTAR Hubble Space Telescope. The auroral observations cover a complete rotation of the planet and, when co-added, they reveal the presence of an auroral emission near 80 degrees N with a brightness of about 150 kR of total H-2 emission. The maximum vertical optical depth at 210 nm is found to be located similar to 5 degrees equatorward of the auroral emission zone. The haze particles are presumably formed by hydrocarbon aerosols initiated by H2+ auroral production. In this case, the 3 x 10(^10) W of H2 emission observed with the FOG, combined with the deduced haze optical depth requires an efficiency of aerosol formation of about 7%. This result indicates that auroral production of hydrocarbon aerosols is a viable source of high-latitude haze

    Effects of improved complementary feeding and improved water, sanitation and hygiene on early child development among HIV-exposed children: substudy of a cluster randomised trial in rural Zimbabwe.

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    Introduction: HIV-exposed uninfected children may be at risk of poor neurodevelopment. We aimed to test the impact of improved infant and young child feeding (IYCF) and improved water, sanitation and hygiene (WASH) on early child development (ECD) outcomes. Methods: Sanitation Hygiene Infant Nutrition Efficacy was a cluster randomised 2×2 factorial trial in rural Zimbabwe ClinicalTrials.gov NCT01824940). Pregnant women were eligible if they lived in study clusters allocated to standard-of-care (SOC; 52 clusters); IYCF (20 g small-quantity lipid-based nutrient supplement/day from 6 to 18 months, complementary feeding counselling; 53 clusters); WASH (pit latrine, 2 hand-washing stations, liquid soap, chlorine, play space, hygiene counselling; 53 clusters) or IYCF +WASH (53 clusters). Participants and fieldworkers were not blinded. ECD was assessed at 24 months using the Malawi Developmental Assessment Tool (MDAT; assessing motor, cognitive, language and social skills); MacArthur Bates Communication Development Inventory (assessing vocabulary and grammar); A-not-B test (assessing object permanence) and a self-control task. Intention-to-treat analyses were stratified by maternal HIV status. Results: Compared with SOC, children randomised to combined IYCF +WASH had higher total MDAT scores (mean difference +4.6; 95% CI 1.9 to 7.2) and MacArthur Bates vocabulary scores (+8.5 words; 95% CI 3.7 to 13.3), but there was no evidence of effects from IYCF or WASH alone. There was no evidence that that any intervention impacted object permanence or self-control. Conclusions: Combining IYCF and WASH interventions significantly improved motor, language and cognitive development in HIV-exposed children. Trial registration number: NCT01824940

    The Grizzly, December 2, 1988

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    No Longer Stoned by Administration: Charges Dropped • 145 Chickens of Chadwick Chain Check In • Letter: Cross Country Earns Kudos • Lantern Thrives at Fifty-five • Peace Hosts a Challenge • Happy Hanukkah! • Happenin\u27 Holidays • Hallelujah to Handel\u27s Messiah Performance • Hermann and Murphy Take Grizzly Reins • Crossroads Debuts • Ursinus Hoopsters\u27 Clutch Plays Lift Bears\u27 to Fast Start • \u27Mers Sunk by W.C. • Ursinus\u27 Lady Bears Riding 4-Game Win Streak • Ursinus Gymnasts Open Season at Navy • Bravo! Bravo! • Speth Sets Better Limit • Dean Nace Leads MBA Race • Outstanding Alumnae Address Whitians • Maintenance Maintains Ursinus • Final Exam Schedulehttps://digitalcommons.ursinus.edu/grizzlynews/1225/thumbnail.jp

    Enhanced C2_2H2_2 absorption within Jupiter's southern auroral oval from Juno UVS observations

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    Reflected sunlight observations from the Ultraviolet Spectrograph (UVS) on the Juno spacecraft were used to study the distribution of acetylene (C2_2H2_2) at Jupiter's south pole. We find that the shape of the C2_2H2_2 absorption feature varies significantly across the polar region, and this can be used to infer spatial variability in the C2_2H2_2 abundance. There is a localized region of enhanced C2_2H2_2 absorption which coincides with the location of Jupiter's southern polar aurora; the C2_2H2_2 abundance poleward of the auroral oval is a factor of 3 higher than adjacent quiescent, non-auroral longitudes. This builds on previous infrared studies which found enhanced C2_2H2_2 abundances within the northern auroral oval. This suggests that Jupiter's upper-atmosphere chemistry is being strongly influenced by the influx of charged auroral particles and demonstrates the necessity of developing ion-neutral photochemical models of Jupiter's polar regions.Comment: Accepted in JGR: Planet

    The complex behavior of the satellite footprints at Jupiter: the result of universal processes?

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    At Jupiter, some auroral emissions are directly related to the electromagnetic interaction between the moons Io, Europa and Ganymede on one hand and the rapidly rotating magnetospheric plasma on the other hand. Out of the three, the Io footprint is the brightest and the most studied. Present in each hemisphere, it is made of at least three different spots and an extended trailing tail. The variability of the brightness of the spots as well as their relative location has been tentatively explained with a combination of Alfvén waves’ partial reflections on density gradients and bi-directional electron acceleration at high latitude. Should this scenario be correct, then the other footprints should also show the same behavior. Here we show that all footprints are, at least occasionally, made of several spots and they all display a tail. We also show that these spots share many characteristics with those of the Io footprint (i.e. some significant variability on timescales of 2-3 minutes). Additionally, we present some Monte-Carlo simulations indicating that the tails are also due to Alfvén waves electron acceleration rather than quasi-static electron acceleration. Even if some details still need clarification, these observations strengthen the scenario proposed for the Io footprint and thus indicate that these processes are universal. In addition, we will present some early results from Juno-UVS concerning the location and morphology of the footprints during the first low-altitude observations of the polar aurorae. These observations, carried out in previously unexplored longitude ranges, should either confirm or contradict our understanding of the footprints

    Clinical and Genetic Tumor Characteristics of Responding and Non-Responding Patients to PD-1 Inhibition in Hepatocellular Carcinoma.

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    Immune checkpoint inhibitors (ICIs) belong to the therapeutic armamentarium in advanced hepatocellular carcinoma (HCC). However, only a minority of patients benefit from immunotherapy. Therefore, we aimed to identify indicators of therapy response. This multicenter analysis included 99 HCC patients. Progression-free (PFS) and overall survival (OS) were studied by Kaplan-Meier analyses for clinical parameters using weighted log-rank testing. Next-generation sequencing (NGS) was performed in a subset of 15 patients. The objective response (OR) rate was 19% median OS (mOS)16.7 months. Forty-one percent reached a PFS > 6 months; these patients had a significantly longer mOS (32.0 vs. 8.5 months). Child-Pugh (CP) A and B patients showed a mOS of 22.1 and 12.1 months, respectively. Ten of thirty CP-B patients reached PFS > 6 months, including 3 patients with an OR. Tumor mutational burden (TMB) could not predict responders. Of note, antibiotic treatment within 30 days around ICI initiation was associated with significantly shorter mOS (8.5 vs. 17.4 months). Taken together, this study shows favorable outcomes for OS with low AFP, OR, and PFS > 6 months. No specific genetic pattern, including TMB, could identify responders. Antibiotics around treatment initiation were associated with worse outcome, suggesting an influence of the host microbiome on therapy success

    Possible Transient Luminous Events observed in Jupiter's upper atmosphere

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    11 transient bright flashes were detected in Jupiter's atmosphere using the UVS instrument on the Juno spacecraft. These bright flashes are only observed in a single spin of the spacecraft and their brightness decays exponentially with time, with a duration of ~1.4 ms. The spectra are dominated by H2 Lyman band emission and based on the level of atmospheric absorption, we estimate a source altitude of 260 km above the 1-bar level. Based on these characteristics, we suggest that these are observations of Transient Luminous Events (TLEs) in Jupiter's upper atmosphere. In particular, we suggest that these are elves, sprites or sprite halos, three types of TLEs that occur in the Earth's upper atmosphere in response to tropospheric lightning strikes. This is supported by visible light imaging, which shows cloud features typical of lightning source regions at the locations of several of the bright flashes. TLEs have previously only been observed on Earth, although theoretical and experimental work has predicted that they should also be present on Jupiter.Comment: Accepted in JGR: Planets. 28 pages, 8 figure
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