A Jovian Magnetodisc Model for the Juno Era Connerney, J. E. P.; Timmins, S.; Herceg, M. ...
Journal of geophysical research. Space physics,
October 2020, Letnik:
125, Številka:
10
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The Jovian magnetosphere assumes a disc‐like geometrical configuration (“magnetodisc”) owing to the persistent presence of a system of azimuthal currents circulating in a washer‐shaped volume aligned ...with, or near, the magnetic equatorial plane. A Voyager era empirical model of the magnetodisc is fitted to vector magnetic field measurements obtained during the Juno spacecraft's first 24 orbits. The best fitting (within 30 Jovian radii) magnetodisc model is characterized by an inner and outer radius of 7.8 and 51.4 Jovian radii, a half‐thickness of 3.6 Jovian radii, with a surface normal at 9.3° from the Jovigraphic pole and 204.2° System 3 west longitude. We supplement the magnetodisc model with a second current system, also confined to the magnetic equatorial plane, consisting of outward radial currents that presumably effect the transfer of angular momentum to outward flowing plasma. Allowing for variation of the magnetodisc's azimuthal and radial current systems from one 53‐day orbit to the next, we develop an index of magnetospheric activity that may be useful in interpretation of variations in auroral observations.
Key Points
An empirical magnetodisc model is fitted to the Juno magnetic field observations
The magnetodisc model provides a more accurate representation of the magnetic field in the inner and middle magnetosphere of Jupiter
The model is independently tested via observations of charged particle interactions with the Jovian satellites
A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. ...Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter's magnetic field with a coarse longitudinal separation of ~45 deg between perijoves. The magnetic field is represented with a degree 20 spherical harmonic model for the planetary ("internal") field, combined with a simple model of the magnetodisc for the field ("external") due to distributed magnetospheric currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model ("Juno Reference Model through Perijove 9") of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed view of a planetary dynamo beyond Earth.
A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during 32 of its first 33 polar orbits. These Prime ...Mission orbits sample Jupiter's magnetic field nearly uniformly in longitude (∼11° separation) as measured at equator crossing. The planetary magnetic field is represented with a degree 30 spherical harmonic and the external field is approximated near the origin with a simple external spherical harmonic of degree 1. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“JRM33”) of the planetary magnetic field with spherical harmonic coefficients reasonably well determined through degree and order 13. Useful information regarding the field extends through degree 18, well fit by a Lowes' spectrum with a dynamo core radius of 0.81 Rj, presumably the outer radius of the convective metallic hydrogen region. This new model provides a most detailed view of a planetary dynamo and evidence of advection of the magnetic field by deep zonal winds in the vicinity of the Great Blue Spot (GBS), an isolated and intense patch of flux near Jupiter's equator. Comparison of the JRM33 and JRM09 models suggests secular variation of the field in the vicinity of the GBS during Juno's nearly 5 years of operation in orbit about Jupiter. The observed secular variation is consistent with the penetration of zonal winds to a depth of ∼3,500 km where a flow velocity of ∼0.04 ms−1 is required to match the observations.
Plain Language Summary
Characterizing the planetary magnetic field of Jupiter is one of the primary science objectives of the Juno Mission. Is the magnetic field generated within the outer envelope consisting mostly of molecular hydrogen, or is it generated at depth where hydrogen becomes metallic under great pressure? The Juno spacecraft, in polar orbit about Jupiter since July 2016, just completed its baseline mapping mission of 33 orbits, providing global coverage of Jupiter's magnetic field near the planet. A detailed representation of the field has emerged, suggesting that Jupiter's magnetic field is generated by dynamo action at depth (beneath 0.81 Rj) in convective metallic hydrogen. A change in Jupiter's magnetic field over time (“secular variation”) was identified by comparison of the model field with that of an earlier model. The secular variation appeared on the flanks of an isolated magnetic patch (the “Great Blue Spot” (GBS)) and can be explained by the eastward motion of the field of the GBS, carried by zonal winds at a depth (∼3,500 km) where molecular hydrogen is sufficiently electrically conductive to grip the magnetic field.
Key Points
The Juno spacecraft sampled Jupiter's vector magnetic field along 32 polar passes separated by ∼11° longitude at the equator
A degree 18 spherical harmonic model of Jupiter's magnetic field is obtained by partial solution of a degree 30 linear system
The new model is consistent with dynamo action in metallic hydrogen, advection of the field by deep zonal winds, and secular variation
The micro Advanced Stellar Compass is an attitude reference for the MAG investigation onboard Juno. The μASC camera head unit images the star field with a CCD that is also sensitive to particles with ...enough energy to pass through the camera shielding: >15 MeV electrons and >80 MeV protons. This provides the capability to monitor fluxes of high‐energy particles in Jupiter’s magnetosphere. A survey of energetic electron fluxes sampled during the first 47 Juno orbits reveals instances of variations observed when Juno is traversing the M‐shell of the Galilean moons. Juno's traversal of the Europa M‐shell often results in distinctly particle signatures. We present the μASC observations of increased electron flux during the crossing of Europa’s plasma wake, and depletion of energetic electron flux on the upstream side. The upstream/downstream differences indicate that the wake environment of Europa drives strong pitch angle scattering on relativistic electrons.
Plain Language Summary
The attitude reference (μASC) used for the MAG investigation onboard Juno is also sensitive to particles with enough energy to pass through the camera shielding. This provides the capability to monitor fluxes of high‐energy particles in Jupiter’s magnetosphere, as the Juno has done since orbit insertion. A μASC survey of electron fluxes reveals instances of variations observed when Juno is traversing the M‐shell of Jupiter’s moon Europa. We present particle signatures related to the interaction with Europa and discuss the implications.
Key Points
Europa’s wake affects the high‐energy electron driftshell by scattering electrons into the loss‐cone
Increase in e− flux is around x2.3 at distances ∼30 RE, and is gradually dissolved as far as 20° downstream
Europa will stop the energetic electron drift shells and will be mostly free from hard radiation on the leading side
Introduction
Despite a variety of pharmacological and psychotherapeutic interventions, treatment of schizophrenia can still be challenging, even more when certain comorbidities are present. ...Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junctions caused by antibodies against acetylcholine and tyrosine kinase. While co-occurrence of schizophrenia and MG is rare, treatment can be complicated as specific treatment of one condition can lead to worsening of other (e.g. anticholinergic side effects of psychopharmacotherapy, psychiatric side effects of corticosteroids).
Objectives
To discuss treatment difficulties in the case of a patient with schizophrenia and multiple somatic comorbidities, including MG.
Methods
A case report and a review of literature.
Results
We report a case of a 50-year-old female patient who was admitted to psychiatric hospital due to psychotic decompensation presented with dysphoria, paranoid delusions, agitation, verbal aggression and hostility. Clinical presentation and psychopharmacological treatment were complicated with her comorbid disorders, MG, which was recently treated because of a relapse, and hypothyroidism, which worsened as she neglected her regular check-ups. Multidisciplinary approach was needed to control the symptoms of her comorbid disorders, which, especially MG, limited psychopharmacological options. Combination of antipsychotics (aripiprazole, haloperidol) and mood stabilizer (sodium valproate) led to clinical improvement of psychotic symptoms. However, poor insight remained- the patient insisted on demission and was not interested in suggested psychotherapeutic and sociotherapeutic programs.
Conclusions
In complex cases like this, multidisciplinary approach is essential for adequate treatment of both psychiatric and comorbid somatic disorders. Conditions like MS can prolong treatment or even worsen the symptoms of a psychiatric disorder, especially since they limit the use of psychopharmacotherapy. Due to this, psychotherapeutic interventions could be even more important to keep a stable remission with a good insight and adherence to both psychiatric and somatic treatment.
Disclosure of Interest
None Declared
Ekbom syndrome: a case report Bosnjak Kuharic, D.; Cvitanic Mazuran, M.; Polšek, D. ...
European psychiatry,
06/2022, Letnik:
65, Številka:
S1
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Introduction
Ekbom syndrome is a clinical term for delusional parasitosis, a condition characterized by the belief that one’s skin is infested by invisible parasites. Despite having no medical ...evidence, patients strive to prove their illness and interpret different sensations and symptoms as infestation with parasites.
Objectives
Our objective was to present a case report of a patient with Ekbom syndrome with detailed clinical information and treatment complications.
Methods
We included patient’s history, psychiatric evaluation, complete diagnostic work-up, therapy and follow-up.
Results
A 60-years old female patient was admitted to her first hospital treatment in our psychiatric clinic. Upon admittance, she was extremely tense, preoccupied with the idea that bed bugs have infested her body. She showed extensive medical documentation, including numerous dermatologic reports regarding her condition, interpreting them in accordance with her delusions. In attempt to help herself and “release” the bugs, she harmed herself causing multiple skin lesions across her body and face. The treatment was complicated with secondary skin infections, ulcers, cellulitis and oedemas. Initial treatment with olanzapine was switched to risperidone due to side-effects (sedation, increase of appetite, weight gain). Gradually, with pharmacological treatment, psychoeducation and support, remission was achieved, but poor insight to her previous condition and psychiatric symptoms remained.
Conclusions
Ekbom syndrome presents a serious disorder that can be complicated with secondary somatic complications, often requiring involvement of different medical specialists. Moreover, lack of insight into the need for psychiatric treatment can lead to therapy discontinuation and relapse of symptoms.
Disclosure
No significant relationships.
An initial condition-index chaos shift keying modulation is proposed. This design aims to increase the spectral and energy efficiencies to unprecedented levels. The proposed scheme exploits the ...initial conditions to generate different chaotic sequences to convey extra bits per transmission. In the proposed design, the input data stream is formed in blocks of $p_{{\rm tot}} = n + 1$ptot=n+1 bits. In this architecture, n bits are mapped into $N = 2^n$N=2n predetermined initial conditions that are used to generate unique chaotic sequences at the transmitter. At the receiver side, the predetermined initial conditions are used to generate a set of N chaotic sequences that are correlated with the received signal. The index of the initial condition for which the chaotic sequence produces a maximum correlation with the received signal is selected to recover the mapped bits, and the corresponding sequence is used to despread the transmitted modulated bit. To validate the proposed scheme, the bit error rate over fading channels is analysed and formulated and the proposed system performance is compared with other conventional and index modulation schemes. In comparison to rival modulation schemes, the results obtained in the proposed work show a competitive performance.
IntroductionMany patients with schizophrenia are unable to achieve adequate levels of psychosocial functioning and quality of life despite of the remission of illness symptoms. According to previous ...reports, only one-third of patients with symptomatic remission reach functional remission. While current pharmacotherapy options seem to be relatively effective for different symptoms of schizophrenia (e.g. positive symptoms), more specific psychosocial interventions that could enable functional remission are yet to be developed.ObjectivesOur objective is to investigate differences in psychopathology, quality of life, functioning, and achieving functional remission before and after specific group treatments developed in our clinic.MethodsWe will conduct a prospective study including a consecutive cohort of female patients older than 18 years of age, which fulfilled the criteria for schizophrenia and schizoaffective disorder according to the International Classification of Disorders, 10th revision. Exclusion criteria are intellectual disabilities, mental disorders due to known physiological or neurological conditions, lactation or pregnancy, treatment with medications that can provoke psychosis, alcoholism, and other addictions. Patients will be recruited after finished hospital treatment or during individual outpatient controls. The Recovery Helm will be used at the beginning of the treatment, to make individual treatment plan and include patients in specific programs including day hospital treatment and/or outpatient group programs: psychoeducation, relaxation, metacognitive training, and social skills training. Besides collecting sociodemographic data, pre- and post-treatment assessment will include the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF), the Quality of Life Scale (QLS), and the “Functional Remission of General Schizophrenia” (FROGS) scale.ResultsWe will analyze the changes in psychopathology levels, quality of life, functioning, and achieving functional remission between the two assessment points, taking into account different treatment possibilities.ConclusionsEvaluation of current available programs can help with recognition of specific needs of patients with schizophrenia and provide guidelines for further development of treatment programs that could be helpful in achieving functional remission.Disclosure of InterestNone Declared
The ESA Swarm mission, launched on 22 November 2013, consists of three spacecraft each equipped with a Micro Advanced Stellar Compass (
μ
ASC) from the Technical University of Denmark (DTU). Each
μ
...ASC features three Camera Head Units (CHUs) orientated orthogonally to optimize system accuracy performance and avoid simultaneous blinding. The image sensors inside the CHUs are sensitive to ionizing radiation. When an energetic particle impacts the image sensor, electrons are liberated along the particle’s ionizing track and appear on the source image as white dots dubbed ‘energetic particle detection’ (EPD) events.
For star tracker applications EPDs are normally supressed to support nominal attitude operation. However, in early 2018 software was uploaded to the
μ
ASCs on-board Swarm, which on top of using the EPD measurements to improve the image for star tracking, is reporting the EPD count to the telemetry to ground. This added functionality enables detection and monitoring of high energy particles. By taking advantage of the sample rates (1-2 Hz), the orientation of the camera heads and simultaneous measurements from all three spacecraft spatial derivatives of the EDP aligned to electric and magnetic fields can be determined. Furthermore, since the Swarm spacecraft are in circular, near-polar orbits at an altitude of 450-510 km the spacecraft continuously monitor and map high energy particles at the South Atlantic Anomaly (SAA) of relevance for future mission planning as well as provide detailed time-radiation relations from charge injections processes from e.g. Coronal Mass Ejections (CMEs). In this work we present processes and analysis of four years of high energy radiation data obtained from the Micro Advanced Stellar Compass (
μ
ASC) on board ESA’s Swarm mission, from February 2018 to February 2022.
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