123 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 CUORE Cryostat: A 1-Ton Scale Setup for Bolometric Detectors

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    The cryogenic underground observatory for rare events (CUORE) is a 1-ton scale bolometric experiment whose detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. This will be the largest bolometric mass ever operated. The experiment will work at a temperature around or below 10 mK. CUORE cryostat consists of a cryogen-free system based on pulse tubes and a custom high power dilution refrigerator, designed to match these specifications. The cryostat has been commissioned in 2014 at the Gran Sasso National Laboratories and reached a record temperature of 6 mK on a cubic meter scale. In this paper, we present results of CUORE commissioning runs. Details on the thermal characteristics and cryogenic performances of the system will be also given.Comment: 7 pages, 2 figures, LTD16 conference proceedin

    Long-term outcomes for children with disability and severe acute malnutrition in Malawi

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    INTRODUCTION: Severe acute malnutrition (SAM) and disability are major global health issues. Although they can cause and influence each other, data on their co-existence are sparse. We aimed to describe the prevalence and patterns of disability among a cohort of children with SAM. METHODS: A longitudinal cohort study in Malawi followed SAM survivors up to 7 years postdischarge. Clinical and anthropometric profiles were compared with sibling and community controls. Disability at original admission was identified clinically; at 7-year follow-up a standardised screening tool called 'the Washington Group Questionnaire' was used. RESULTS: 60/938 (6.4%) of admissions to SAM treatment had clinically obvious disability at admission. Post-treatment mortality was high, with only 11/60 (18%) surviving till 7-year follow-up. SAM children with a disability at admission had 6.99 (95% CI 3.49 to 14.02; p<0.001) greater risk of dying compared with children without disability. They were also older, less likely to be HIV positive or have oedema and more severely malnourished. Long-term survivors were more stunted, had less catch-up growth, smaller head circumference, weaker hand grip strength and poorer school achievement than non-disabled survivors.The Washington Group Questionnaire confirmed disability in all who had been identified clinically, and identified many who had not been previously flagged. CONCLUSION: Disability is common among children affected by SAM. Those with disability-associated SAM have greatly increased risk of dying even if they survive the initial episode of malnutrition. Survivors have poorer growth, physical strength and school achievement. To enable all children to survive and thrive post-SAM, it is vital to focus more on those with disabilities. SAM treatment programmes should consider using not just clinical assessment but structured assessments to better identify at-risk individuals as well as understand the population of children for which they are developing services

    The Toronto Concussion Study: a prospective investigation of characteristics in a cohort of adults from the general population seeking care following acute concussion, 2016–2020

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    PurposeThere is limited research regarding the characteristics of those from the general population who seek care following acute concussion.MethodsTo address this gap, a large cohort of 473 adults diagnosed with an acute concussion (female participants = 287; male participants = 186) was followed using objective measures prospectively over 16 weeks beginning at a mean of 5.1 days post-injury.ResultsFalls were the most common mechanism of injury (MOI) (n = 137, 29.0%), followed by sports-related recreation (n = 119, 25.2%). Male participants were more likely to be injured playing recreational sports or in a violence-related incident; female participants were more likely to be injured by falling. Post-traumatic amnesia (PTA) was reported by 80 participants (16.9 %), and loss of consciousness (LOC) was reported by 110 (23.3%). In total, 54 participants (11.4%) reported both PTA and LOC. Male participants had significantly higher rates of PTA and LOC after their injury compared to their female counterparts. Higher initial symptom burden was associated with a longer duration of recovery for both male and female participants. Female participants had more symptoms and higher severity of symptoms at presentation compared to male participants. Female participants were identified to have a longer recovery duration, with a mean survival time of 6.50 weeks compared to 5.45 weeks in male participants (p &lt; 0.0001). A relatively high proportion of female and male participants in this study reported premorbid diagnoses of depression and anxiety compared to general population characteristics.ConclusionAlthough premorbid diagnoses of depression and/or anxiety were associated with higher symptom burden at the initial visit, the duration of symptoms was not directly associated with a pre-injury history of psychological/psychiatric disturbance. This cohort of adults, from the general population, seeking care for their acute concussion attained clinical and functional recovery over a period of 4–12 weeks

    Impact of model physics on estimating the surface mass balance of the Greenland ice sheet

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    Long-term predictions of sea level rise from increased Greenland ice sheet melting have been derived using Positive Degree Day models only. It is, however, unknown precisely what uncertainties are associated with applying this simple surface melt parameterization for future climate. We compare the behavior of a Positive Degree Day and Energy Balance/ Snowpack model for estimating the surface mass balance of the Greenland ice sheet under a warming climate. Both models were first tuned to give similar values for present-day mass balance using 10 years of ERA-40 climatology and were then run for 300 years, forced with the output of a GCM in which atmospheric CO2 increased to 4 times preindustrial levels. Results indicate that the Positive Degree Day model is more sensitive to climate warming than the Energy Balance model, generating annual runoff rates almost twice as large for a fixed ice sheet geometry. Roughly half of this difference was due to differences in the volume of melt generated and half was due to differences in refreezing rates in the snowpack. Our results indicate that the modeled snowpack properties evolve on a multidecadal timescale to changing climate, with a potentially large impact on the mass balance of the ice sheet; an evolution that was absent from the Positive Degree Day model. Copyright 2007 by the American Geophysical Union

    Jupiter's X-ray Emission 2007 Part 2:Comparisons with UV and Radio Emissions and In-Situ Solar Wind Measurements

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    We compare Chandra and XMM‐Newton X‐ray observations of Jupiter during 2007 with a rich multi‐instrument dataset including: upstream in‐situ solar wind measurements from the New Horizons spacecraft, radio emissions from the Nançay Decametric Array and Wind/Waves, and UV observations from the Hubble Space Telescope. New Horizons data revealed two corotating interaction regions (CIRs) impacted Jupiter during these observations. Non‐Io decametric bursts and UV emissions brightened together and varied in phase with the CIRs. We characterise 3 types of X‐ray aurorae: hard X‐ray bremsstrahlung main emission, pulsed/flared soft X‐ray emissions and a newly identified dim flickering (varying on short‐timescales, but quasi‐continuously present) aurora. For most observations, the X‐ray aurorae were dominated by pulsed/flaring emissions, with ion spectral lines that were best fit by Iogenic plasma. However, the brightest X‐ray aurora was coincident with a magnetosphere expansion. For this observation, the aurorae were produced by both flickering emission and erratic pulses/flares. Auroral spectral models for this observation required the addition of solar wind ions to attain good fits, suggesting solar wind entry into the outer magnetosphere or directly into the pole for this particularly bright observation. X‐ray bremsstrahlung from high energy electrons was only bright for one observation, which was during a forward shock. This bremsstrahlung was spatially coincident with bright UV main emission (power> 1TW) and X‐ray ion spectral line dusk emission, suggesting closening of upward and downward current systems during the shock. Otherwise, the bremsstrahlung was dim and UV main emission power was also lower(<700 GW), suggesting their power scaled together

    Jupiter’s auroras during the Juno approach phase as observed by the Hubble Space Telescope

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    We present movies of the Hubble Space Telescope (HST) observations of Jupiter’s FUV auroras observed during the Juno approach phase and first capture orbit, and compare with Juno observations of the interplanetary medium near Jupiter and inside the magnetosphere. Jupiter’s FUV auroras indicate the nature of the dynamic processes occurring in Jupiter’s magnetosphere, and the approach phase provided a unique opportunity to obtain a full set of interplanetary data near to Jupiter at the time of a program of HST observations, along with the first simultaneous with Juno observations inside the magnetosphere. The overall goal was to determine the nature of the solar wind effect on Jupiter’s magnetosphere. HST observations were obtained with typically 1 orbit per day over three intervals: 16 May – 7 June, 22-30 June and 11-18 July, i.e. while Juno was in the solar wind, around the bow shock and magnetosphere crossings, and in the mid-latitude middle-outer magnetospheres. We show that these intervals are characterised by particularly dynamic polar auroras, and significant variations in the auroral power output caused by e.g. dawn storms, intense main emission and poleward forms. We compare the variation of these features with Juno observations of interplanetary compression regions and the magnetospheric environment during the intervals of these observations

    The two faces of the Jovian UV aurorae

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    Being mostly connected via closed magnetic field lines, the aurorae at the two poles display two broadly similar signatures of the same magnetospheric processes. However, differences are sometimes observed, indicative of asymmetries either in the polar regions (e.g. different solar illumination, magnetic anomalies, etc.) or in the magnetosphere (e.g. twisting of the magnetotail), thus showing two complementary sides of the magnetosphere-ionosphere coupling.&lt;/p&gt;&lt;p&gt;Whatever the planet, seeing the aurorae on both poles at the same time is challenging. Either both polar regions can be seen at once, but then only from the side, with poor spatial coverage (especially close and beyond the limb), or we need (at least) two observatories. Here we use the latter option to observe the two faces of the UV aurorae on Jupiter. In the last years, several Hubble Space Telescope observations with the Space Telescope Imaging Spectrograph (STIS) have been planned during close-up perijove observations of the poles with the UV spectrograph (UVS) on board the Juno spacecraft. The aurorae at Jupiter can be divided into three main components, with the Main Emissions, a quasi-continuous, but sometimes irregular, ribbon of auroral emissions, delimitating the outer emissions outside of it and the polar emissions inside of it. We compare the global morphology and the relative power emitted by the different auroral features in these three regions. Former studies also indicated that synchronized quasi-periodic flares could be observed in both hemispheres and we will look after similar events in this new dataset. Finally, even if the observations are delayed by approximately one hour, we can still compare the mean emitted power before (north) and after (south) each Juno perijove to look for a global trend.&lt;/p&gt

    Early development in children with moderate acute malnutrition: A cross-sectional study in Burkina Faso

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    Malnutrition impairs cognitive, communication, and motor development, but it is not known how nutrition and health are associated with development in children with moderate acute malnutrition (MAM). We aimed to describe motor and language development of children with MAM and explore its nutrition and health-related correlates. This cross-sectional study used baseline data from a nutritional trial in children with MAM aged 6-23 months in Burkina Faso. Motor and language skills were assessed using the Malawi Development Assessment Tool (MDAT). Linear mixed models were used to explore potential correlates of MDAT including socio-economic status, anthropometry, body composition, whole-blood polyunsaturated fatty acids (PUFA), haemoglobin (Hb), iron status, and morbidity. We also assessed child and caregiver participation during MDAT procedures and their associations with correlates and development. MDAT data were available for 1.608 children. Mean (95% CI) MDAT z-scores were -0.39 (-0.45, -0.34) for gross motor, 0.54 (0.48, 0.59) for fine motor, and -0.91 (-0.96, -0.86) for language skills. Children with higher mid-upper arm circumference, weight-for-height, height-for-age, fat-free mass, n-3 PUFAs, Hb, and iron status had better MDAT z-scores, whereas children with more fat mass index, anaemia, illness, and inflammation had poorer z-scores. In addition, children living in larger households or with an unmarried mother had poorer MDAT z-scores. Associations between morbidity and z-scores were largely explained by children's poorer participation during MDAT assessment. The identified factors associated with child development may inform interventions needed to stimulate development during or after management of MAM

    Jupiter observations at infrared wavelengths by Juno

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    The Jovian InfraRed Auroral Mapper (JIRAM) [1] on board the Juno [2,3] spacecraft, is equipped with an infrared camera and a spectrometer working in the spectral range 2-5 _m. JIRAM was built to study the infrared aurora of Jupiter and to map the planet's atmosphere in the 5 μm spectral region. Its spectroscopic observations in the 2-5 μm range can be used for studying atmospheric dynamics, clouds and measuring the abundance of certain trace species that are important to atmospheric chemistry, microphysics and dynamics such as water, ammonia and phosphine and for the formation of the infrared aurora like the ion H3+.The instrument has operated during most of the Jupiter flybys since science mission started in August 2016 performing several observations of the of the planet from the equator to poles. Unprecedented views of the polar atmospheric structures and auroras have been observed for the first time thanks special nature of Juno's orbit. We present an overview of the most significant observations done by the instrument since the start of the mission.[1] Adriani A. et al., JIRAM, the Jovian Infrared Auroral Mapper. Space Sci. Rew., DOI 10.1007/s11214-014-0094-y, 2014.[2] Bolton S.J. et al., Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft. Science DOI: 10.1126/science.aal2108, 2017.[3] Connerney J. E.P. et al., Jupiter's magnetosphere and aurorae observed by the Juno spacecraft during its first polar orbits. Science, DOI: 10.1126/science.aam5928, 2017
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