27 research outputs found

    Processing tools refinement for the JIRAM arrival to Jupiter

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    The JUNO mission, launched on August 2011 with the goal of investigating the origin and evolution of Jupiter, reached Jupiter in July 2016. The months preceding the JUNO orbit insertion have been crucial for all the instrument teams to check the status and working abilities of the respective experiments. JIRAM (Jupiter Infrared Auroral Mapper), with its imager and slit spectrometer operating over the 2-5μm spectral range will attempt to reveal the deep atmospheric composition -3 to 7 bars- in hot spots, to analyze the infrared auroral emissions of the H3 + molecules ionized by the Jovian magnetosphere currents and to detect the morphology and vertical structure of the clouds. Many different processing tools are in preparation to exploit the incoming JIRAM data. Here some results pertaining to the image quality optimization and the visualizations that can be obtained from the spectrometer data management are reported. <P /

    Morphology of the Auroral Tail of Io, Europa, and Ganymede From JIRAM L-Band Imager

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    Jupiter hosts intense auroral activity associated with charged particles precipitating into the planet's atmosphere. The Galilean moons orbiting within the magnetosphere are swept by the magnetic field: the resulting perturbation travels along field lines as Alfven waves, which are able to accelerate electrons toward the planet, producing satellite-induced auroral emissions. These emissions due to the moons, known as footprints, can be detected in various wavelengths (UV, visible, IR) outside the main auroral emission as multiple bright spots followed by footprint tails. Since 2016 the Juno spacecraft orbiting Jupiter has surveyed the polar regions more than 30 times at close distances. Onboard the spacecraft, the Jovian InfraRed Auroral Mapper (JIRAM) is an imager and spectrometer with an L-band imaging filter suited to observe auroral features at unprecedented spatial resolution. JIRAM revealed a rich substructure in the footprint tails of Io, Europa, and Ganymede, which appear as a trail of quasi-regularly spaced bright sub-dots whose intensity fades away along the emission trail as the spatial separation from the footprint increases. The fine structure of the Europa and Ganymede footprint tails is reported in this work for the first time. We will also show that the typical distance between subsequent sub-dots is the same for all three moons at JIRAM resolution in both hemispheres. In addition, the sub-dots observed by JIRAM are static in a frame corotating with Jupiter. A feedback mechanism between the ionosphere and the magnetosphere is suggested as a potential candidate to explain the morphology of the footprint tails

    Impact of neuraminidase inhibitors on influenza A(H1N1)pdm09‐related pneumonia: an individual participant data meta‐analysis

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    BACKGROUND: The impact of neuraminidase inhibitors (NAIs) on influenza‐related pneumonia (IRP) is not established. Our objective was to investigate the association between NAI treatment and IRP incidence and outcomes in patients hospitalised with A(H1N1)pdm09 virus infection. METHODS: A worldwide meta‐analysis of individual participant data from 20 634 hospitalised patients with laboratory‐confirmed A(H1N1)pdm09 (n = 20 021) or clinically diagnosed (n = 613) ‘pandemic influenza’. The primary outcome was radiologically confirmed IRP. Odds ratios (OR) were estimated using generalised linear mixed modelling, adjusting for NAI treatment propensity, antibiotics and corticosteroids. RESULTS: Of 20 634 included participants, 5978 (29·0%) had IRP; conversely, 3349 (16·2%) had confirmed the absence of radiographic pneumonia (the comparator). Early NAI treatment (within 2 days of symptom onset) versus no NAI was not significantly associated with IRP [adj. OR 0·83 (95% CI 0·64–1·06; P = 0·136)]. Among the 5978 patients with IRP, early NAI treatment versus none did not impact on mortality [adj. OR = 0·72 (0·44–1·17; P = 0·180)] or likelihood of requiring ventilatory support [adj. OR = 1·17 (0·71–1·92; P = 0·537)], but early treatment versus later significantly reduced mortality [adj. OR = 0·70 (0·55–0·88; P = 0·003)] and likelihood of requiring ventilatory support [adj. OR = 0·68 (0·54–0·85; P = 0·001)]. CONCLUSIONS: Early NAI treatment of patients hospitalised with A(H1N1)pdm09 virus infection versus no treatment did not reduce the likelihood of IRP. However, in patients who developed IRP, early NAI treatment versus later reduced the likelihood of mortality and needing ventilatory support

    Spectral ultraviolet measurements by a multichannel monitor and a Brewer spectroradiometer: A field study

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    Two different instruments for measuring, the spectral UV irradiance were used in a field comparison study in July 2000 in Rome, Italy: a Brewer spectrophotometer and a moderate-bandwidth idler radiometer (GUV-511C). The Brewer is designed to measure file solar spectral irradiances in the region from 290 nm to 325 nm with a spectral resolution of 0.5 nm. The GUV-511C measures band-averaged spectral irradiance at four wavelengths: 305. 320. 340 and 380 nm with a bandwidth depending oil the filter type for each channel (about 10 nm full width half maximum, FWHM). Comparisons between the two instruments Were made for 5 days for the two wavelengths 305 and 320 nm under different meteorological conditions with the Brewer taken as the reference

    Imidazoline receptors: Qualitative structure-activity relationships and discovery of tracizoline and benazoline. Two ligands with high affinity and unprecedented selectivity

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    The observation that all the attempts to characterize imidazoline (I) receptors have been carried out with non-selective or poorly selective ligands prompted us to undertake research aimed at developing selective ligand(s). In previous work using, as a starting point, cirazoline 1, a potent alpha1-adrenergic receptor agonist that also binds to I receptors, we showed that removal of the cyclopropyl ring (2) retains high affinity for 12 receptors while reducing alpha1-adrenergic agonist activity. However, it was felt that this residual, albeit modest, alpha1-adrenergic agonist activity might diminish the usefulness of compound 2, and we now report on our continuing efforts in this field. Starting from compound 2, we first eliminated the alpha1-agonist component by isosteric replacement and then, by means of conformational restrictions on compound 7, succeeded in discovering tracizoline (9) and benazoline (12). These two new ligands with high affinity (pKi value 8.74 and 9.07, respectively) and unprecedented selectivity with respect to both alpha2- (I2/alpha2 7,762 and 18,621) and alpha1- (I2/alpha1 2,344 and 2,691) adrenergic receptors, are valuable tools in the study of I receptor structure and function. In addition, the large number of derivatives studied has allowed us to establish congruent qualitative structure-activity relationships and identify some structural elements governing affinity and selectivity
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