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1.
J Geophys Res Planets ; 127(5): e2021JE007083, 2022 May.
Article in English | MEDLINE | ID: mdl-35865508

ABSTRACT

The Nadir and Occultation for MArs Discovery (NOMAD) instrument suite aboard ExoMars/Trace Gas Orbiter spacecraft is mainly conceived for the study of minor atmospheric species, but it also offers the opportunity to investigate surface composition and aerosols properties. We investigate the information content of the Limb, Nadir, and Occultation (LNO) infrared channel of NOMAD and demonstrate how spectral orders 169, 189, and 190 can be exploited to detect surface CO2 ice. We study the strong CO2 ice absorption band at 2.7 µm and the shallower band at 2.35 µm taking advantage of observations across Martian Years 34 and 35 (March 2018 to February 2020), straddling a global dust storm. We obtain latitudinal-seasonal maps for CO2 ice in both polar regions, in overall agreement with predictions by a general climate model and with the Mars Express/OMEGA spectrometer Martian Years 27 and 28 observations. We find that the narrow 2.35 µm absorption band, spectrally well covered by LNO order 189, offers the most promising potential for the retrieval of CO2 ice microphysical properties. Occurrences of CO2 ice spectra are also detected at low latitudes and we discuss about their interpretation as daytime high altitude CO2 ice clouds as opposed to surface frost. We find that the clouds hypothesis is preferable on the basis of surface temperature, local time and grain size considerations, resulting in the first detection of CO2 ice clouds through the study of this spectral range. Through radiative transfer considerations on these detections we find that the 2.35 µm absorption feature of CO2 ice clouds is possibly sensitive to nm-sized ice grains.

2.
Astron J ; 156(2)2018 Aug.
Article in English | MEDLINE | ID: mdl-30510303

ABSTRACT

We characterize the origin and evolution of a mesoscale wave pattern in Jupiter's North Equatorial Belt (NEB), detected for the first time at 5 µm using a 2016-17 campaign of "lucky imaging" from the VISIR instrument on the Very Large Telescope and the NIRI instrument on the Gemini observatory, coupled with M-band imaging from Juno's JIRAM instrument during the first seven Juno orbits. The wave is compact, with a 1°.1-1°.4 longitude wavelength (wavelength 1300-1600 km, wavenumber 260-330) that is stable over time, with wave crests aligned largely north-south between 14°N and 17°N (planetographic). The waves were initially identified in small (10° longitude) packets immediately west of cyclones in the NEB at 16°N but extended to span wider longitude ranges over time. The waves exhibit a 7-10 K brightness temperature amplitude on top of an ∼210 K background at 5 µm. The thermal structure of the NEB allows for both inertio-gravity waves and gravity waves. Despite detection at 5 µm, this does not necessarily imply a deep location for the waves, and an upper tropospheric aerosol layer near 400-800 mbar could feature a gravity wave pattern modulating the visible-light reflectivity and attenuating the 5-µm radiance originating from deeper levels. Strong rifting activity appears to obliterate the pattern, which can change on timescales of weeks. The NEB underwent a new expansion and contraction episode in 2016-17 with associated cyclone-anticyclone formation, which could explain why the mesoscale wave pattern was more vivid in 2017 than ever before.

3.
Science ; 361(6404): 774-777, 2018 08 24.
Article in English | MEDLINE | ID: mdl-29976795

ABSTRACT

Jupiter's aurorae are produced in its upper atmosphere when incoming high-energy electrons precipitate along the planet's magnetic field lines. A northern and a southern main auroral oval are visible, surrounded by small emission features associated with the Galilean moons. We present infrared observations, obtained with the Juno spacecraft, showing that in the case of Io, this emission exhibits a swirling pattern that is similar in appearance to a von Kármán vortex street. Well downstream of the main auroral spots, the extended tail is split in two. Both of Ganymede's footprints also appear as a pair of emission features, which may provide a remote measure of Ganymede's magnetosphere. These features suggest that the magnetohydrodynamic interaction between Jupiter and its moon is more complex than previously anticipated.

4.
Nature ; 555(7695): 216-219, 2018 03 07.
Article in English | MEDLINE | ID: mdl-29516997

ABSTRACT

The familiar axisymmetric zones and belts that characterize Jupiter's weather system at lower latitudes give way to pervasive cyclonic activity at higher latitudes. Two-dimensional turbulence in combination with the Coriolis ß-effect (that is, the large meridionally varying Coriolis force on the giant planets of the Solar System) produces alternating zonal flows. The zonal flows weaken with rising latitude so that a transition between equatorial jets and polar turbulence on Jupiter can occur. Simulations with shallow-water models of giant planets support this transition by producing both alternating flows near the equator and circumpolar cyclones near the poles. Jovian polar regions are not visible from Earth owing to Jupiter's low axial tilt, and were poorly characterized by previous missions because the trajectories of these missions did not venture far from Jupiter's equatorial plane. Here we report that visible and infrared images obtained from above each pole by the Juno spacecraft during its first five orbits reveal persistent polygonal patterns of large cyclones. In the north, eight circumpolar cyclones are observed about a single polar cyclone; in the south, one polar cyclone is encircled by five circumpolar cyclones. Cyclonic circulation is established via time-lapse imagery obtained over intervals ranging from 20 minutes to 4 hours. Although migration of cyclones towards the pole might be expected as a consequence of the Coriolis ß-effect, by which cyclonic vortices naturally drift towards the rotational pole, the configuration of the cyclones is without precedent on other planets (including Saturn's polar hexagonal features). The manner in which the cyclones persist without merging and the process by which they evolve to their current configuration are unknown.

5.
Stud Health Technol Inform ; 43 Pt A: 305-8, 1997.
Article in English | MEDLINE | ID: mdl-10179560

ABSTRACT

In this work we present FENARETE, a software tool to design and distribute clinical protocols in an Inter/IntraNet framework. We consider a medical protocol as a clinical behaviour scheme, formally and clearly defined with sufficient details. Our work allows the knowledge content of any clinical protocol to be fully represented in a symbolic style. A computer based support tool that works as an interface between clinicians and the protocol knowledge base is regarded by the authors as a basic building block developing an integrated environment for medical protocols design and management. The FENARETE application has been developed in Java and it is available for any Internet-linked machine with a Java-compatible browser.


Subject(s)
Clinical Protocols , Computer Communication Networks , Practice Guidelines as Topic , Software , Humans , Rome , Software Design , User-Computer Interface
6.
Stud Health Technol Inform ; 43 Pt A: 401-5, 1997.
Article in English | MEDLINE | ID: mdl-10179582

ABSTRACT

In this paper a system and new methodologies that enable efficient exploration of distributed collections of multimedia reports are described. A conceptual model for the report and a method to semi-automatically create a hypermedia report network have been defined. The main issues addressed in this project were to exploit the textual component of a report to give a more evident semantic meaning to the data produced during the relative exam and to provide users with new interaction paradigms based on Internet technologies.


Subject(s)
Computer Communication Networks , Information Storage and Retrieval , Multimedia , Humans , Models, Theoretical , Semantics
7.
Comput Biomed Res ; 30(5): 379-402, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9457439

ABSTRACT

In this paper the health resource allocation problem is discussed. An object-oriented system is proposed and its implemented prototype is illustrated. It consists of two parts: a Geographical Information System, which is able to acquire and store both geographical and social-epidemiological information (including the resource distribution on that territory), and a Decision Support System, able to decide, using optimization algorithms, the new resource allocation in order to obtain a quasi-optimal solution for the cost/benefit ratio minimization problem, after having fixed the goal (e.g., the decrease of the incidence of a given disease) and constraints (e.g., a fixed budget, a given set of available resources, etc.). The object-oriented database which is part of the system can simulate and store different scenarios, depending on the different goals and constraints defined in input, by means of a user friendly interface.


Subject(s)
Developing Countries , Health Care Rationing/organization & administration , Management Information Systems , Quality of Life , Algorithms , Cholera/epidemiology , Data Display , Decision Support Techniques , Decision Trees , Diagnosis, Computer-Assisted , Disease Outbreaks/economics , Disease Outbreaks/prevention & control , Epidemiologic Methods , Health Care Costs , Humans , Models, Statistical , Nicaragua , Population Dynamics , Therapy, Computer-Assisted
8.
Comput Methods Programs Biomed ; 48(1-2): 163-8, 1995.
Article in English | MEDLINE | ID: mdl-8846703

ABSTRACT

The health resource allocation problem is discussed in this paper. An object-oriented system, which consists of two parts is proposed and its implemented prototype is illustrated. The first part consists of a Geographical Information System which is able to acquire and store both geographical information regarding the territory under investigation and the socio-epidemiological information and the resource distribution in that moment on the same territory. The second part refers to the strategies and the relative algorithms carried out (using a Decision Support System) to obtain the best solution (allocation of new resources optimizing the cost/benefit ratio) after that the user has fixed a goal (e.g., the decrease of the incidence of a given disease) and has defined some constraints (e.g., a fixed budget, a given set of available resources, etc.). The object-oriented database stores different scenarios, depending on the different goals and constraints defined in input. A user friendly interface was also implemented.


Subject(s)
Decision Support Systems, Management , Geography , Health Care Rationing , Information Systems , Decision Making, Computer-Assisted , Decision Support Techniques , Health Planning , Humans , Malaria/therapy , Systems Integration
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