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  1. Book ; Thesis: Fall-Kontrollstudie zur genetischen Prädisposition von Strumen unter Berücksichtigung exogener Faktoren

    Wicht, Juliane

    2009  

    Author's details Juliane Wicht
    Language German
    Size 111 Bl., graph. Darst.
    Publishing country Germany
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Leipzig, Univ., Diss., 2009
    HBZ-ID HT016281473
    Database Catalogue ZB MED Medicine, Health

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    In stock of ZB MED Cologne/Königswinter

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  2. Conference proceedings ; Online: Modelling the magnetic fields of Uranus and Neptune

    Meyer, C. / Wicht, J.

    XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG)

    2023  

    Abstract: The ice giants Uranus and Neptune are the only observed planets of the solar system which harbour multipolar magnetic fields. Therefore, the question arises why their magnetic fields are not dipolar, as it is the case for the other planets. The only ... ...

    Abstract The ice giants Uranus and Neptune are the only observed planets of the solar system which harbour multipolar magnetic fields. Therefore, the question arises why their magnetic fields are not dipolar, as it is the case for the other planets. The only spacecraft which measured the magnetic fields of Uranus and Neptune was Voyager II in 1986 and 1989. We analyse to which degree the trajectory of Voyager II allows us to determine their fields. In the second step we analyse different multipolar dominated magnetic field simulations with MagIC. We quantify how close these models come to replicate the fields of Uranus or Neptune using two measures. The first measure is a misfit along the Voyager II orbit around the models. The second measure is a comparison of only the well determined Gauss coefficients.
    Language English
    Publishing date 2023-07-11
    Publishing country de
    Document type Conference proceedings ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Conference proceedings ; Online: Dynamo Action of the Zonal Winds in Jupiter and Saturn

    Wicht, J. / Christensen, U. / Preising, M.

    XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG)

    2023  

    Abstract: Gravity measurements by the Juno and Cassini spacecrafts provide valuable information about the depth dependence of the zonal winds observed in the cloud decks. However, the inversion based on gravity data alone is non-unique and magnetic measurements ... ...

    Abstract Gravity measurements by the Juno and Cassini spacecrafts provide valuable information about the depth dependence of the zonal winds observed in the cloud decks. However, the inversion based on gravity data alone is non-unique and magnetic measurements can provide important additional constraints. We simulate the dynamo action of the zonal winds in Jupiter and Saturn, concentrating on the outer layers where they provide the dominant dynamics. Zonal wind induction provides an efficient means to dampen non-axisymmetric field contributions produced deeper in the planet. The effect increases with the maximum magnetic Reynolds number Rm reached along the zonal wind depth profile. Rm increases with electrical conductivity and with zonal wind speed. Since Jupiter’s field is highly non-axisymmetric, Rm has to remain below one to guarantee only a mild damping. For a given conductivity profile, this provides an independent constraint on the depth dependence of the zonal winds. Saturn’s field, however, seems to be perfectly axisymmetric. Using a new conductivity profile, base on ab initio calculations, in combination with zonal winds profiles suggested by gravity data yields Rm values significantly larger than one. This means that the zonal winds could contribute to making Saturn’s field axisymmetric. For both gas giants, the secular variation caused by zonal winds tends to be very small. We also discuss energy and entropy constraints for the depth of the zonal winds.
    Subject code 551
    Language English
    Publishing date 2023-07-11
    Publishing country de
    Document type Conference proceedings ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Book ; Online: Stable stratification promotes multiple zonal jets in a turbulent Jovian dynamo model

    Gastine, T. / Wicht, J.

    2020  

    Abstract: The ongoing NASA's Juno mission puts new constraints on the internal dynamics of Jupiter. Data gathered by its onboard magnetometer reveal a dipole-dominated surface magnetic field accompanied by strong localised magnetic flux patches. The gravity ... ...

    Abstract The ongoing NASA's Juno mission puts new constraints on the internal dynamics of Jupiter. Data gathered by its onboard magnetometer reveal a dipole-dominated surface magnetic field accompanied by strong localised magnetic flux patches. The gravity measurements indicate that the fierce surface zonal jets extend several thousands of kilometers below the cloud level before rapidly decaying below $0.94-0.96\,R_J$, $R_J$ being the mean Jovian radius at the one bar level. Several internal models suggest an intricate internal structure with a thin intermediate region in which helium would segregate from hydrogen, forming a compositionally-stratified layer. Here, we develop the first global Jovian dynamo which incorporates an intermediate stably-stratified layer between $0.82\,R_J$ and $0.86\,R_J$. Analysing the energy balance reveals that the magnetic energy is almost one order of magnitude larger than kinetic energy in the metallic region, while most of the kinetic energy is pumped into zonal motions in the molecular envelope. Those result from the different underlying force hierarchy with a triple balance between Lorentz, Archimedean and ageostrophic Coriolis forces in the metallic core and inertia, buoyancy and ageostrophic Coriolis forces controlling the external layers. The simulation presented here is the first to demonstrate that multiple zonal jets and dipole-dominated dynamo action can be consolidated in a global simulation. The inclusion of an stable layer is a necessary ingredient that allows zonal jets to develop in the outer envelope without contributing to the dynamo action in the deeper metallic region. Stable stratification however also smooths out the small-scale features of the magnetic field by skin effect. These constraints suggest that possible stable layers in Jupiter should be located much closer to the surface ($0.9-0.95\,R_J$).

    Comment: 22 pages, 16 figures, 2 tables, accepted for publication in Icarus
    Keywords Astrophysics - Earth and Planetary Astrophysics ; Physics - Fluid Dynamics ; Physics - Geophysics
    Subject code 551
    Publishing date 2020-12-11
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Numerical simulations help revealing the dynamics underneath the clouds of Jupiter.

    Wicht, Johannes / Gastine, Thomas

    Nature communications

    2020  Volume 11, Issue 1, Page(s) 2886

    Language English
    Publishing date 2020-06-08
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-020-16680-0
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  6. Book ; Online: The Effects of a Stably Stratified Region with radially varying Electrical Conductivity on the Formation of Zonal Winds on Gas Planets

    Wulff, Paula N. / Christensen, Ulrich R. / Dietrich, Wieland / Wicht, Johannes

    2024  

    Abstract: The outer areas of Jupiter and Saturn have multiple zonal winds, reaching the high latitudes, that penetrate deep into the planets' interiors, as suggested by gravity measurements. These characteristics are replicable in numerical simulations by ... ...

    Abstract The outer areas of Jupiter and Saturn have multiple zonal winds, reaching the high latitudes, that penetrate deep into the planets' interiors, as suggested by gravity measurements. These characteristics are replicable in numerical simulations by including both a shallow stably stratified layer, below a convecting envelope, and increasing electrical conductivity. A dipolar magnetic field, assumed to be generated by a dynamo below our model, is imposed. We find that the winds' depth into the stratified layer depends on the local product of the squared magnetic field strength and electrical conductivity. The key for the drop-off of the zonal winds is a meridional circulation which perturbs the density structure in the stable layer. In the stable region its dynamics is governed by a balance between Coriolis and electromagnetic forces. Our models suggest that a stable layer extending into weakly conducting regions could account for the observed deep zonal wind structures.

    Comment: Accepted by JGR - Planets
    Keywords Astrophysics - Earth and Planetary Astrophysics
    Subject code 551
    Publishing date 2024-01-30
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article: Feasibility, acceptability, and outcome responsiveness of the SYMPERHEART intervention to support symptom perception in persons with heart failure and their informal caregivers: a feasibility quasi-experimental study.

    Santos, Gabrielle Cécile / Liljeroos, Maria / Tschann, Kelly / Denhaerynck, Kris / Wicht, Justine / Jurgens, Corrine Y / Hullin, Roger / Schäfer-Keller, Petra

    Pilot and feasibility studies

    2023  Volume 9, Issue 1, Page(s) 168

    Abstract: Background: Symptom perception is an important process of heart failure (HF) self-care that persons with HF need in order to master self-care management. It also leads to better patient outcomes. Symptom perception consists of body observation and ... ...

    Abstract Background: Symptom perception is an important process of heart failure (HF) self-care that persons with HF need in order to master self-care management. It also leads to better patient outcomes. Symptom perception consists of body observation and analysis, which are both challenging. We aimed to test the feasibility, acceptability, and outcome responsiveness of a novel intervention (SYMPERHEART) delivered to persons with HF with their informal caregiver.
    Methods: We designed SYMPERHEART as a complex evidence-informed education and support intervention targeting body observation and analysis. We conducted a feasibility quasi-experimental study with a single group pre-post-test design. We included three subsamples: persons with HF receiving home-based care, their informal caregivers exposed to SYMPERHEART, and home-care nurses who delivered SYMPERHEART during 1 month. We assessed feasibility by recruitment time, time to deliver SYMPERHEART, eligibility rate, and intervention fidelity. We assessed acceptability by consent rate, retention rate, persons with HF engagement in body observation, and treatment acceptability. Outcome responsiveness was informed by patient-reported (PRO) and clinical outcomes: HF self-care and the informal caregivers' contribution to HF self-care, perception of HF symptom burden, health status, caregivers' burden, and HF events. We performed descriptive analyses for quantitative data and calculated Cohen's d for PROs. A power analysis estimated the sample size for a future full-scale effectiveness study.
    Results: We included 18 persons with HF, 7 informal caregivers, and 9 nurses. Recruitment time was 112.6 h. The median time to deliver SYMPERHEART for each participant was 177.5 min. Eligibility rate was 55% in persons with HF. Intervention fidelity revealed that 16 persons with HF were exposed to body observation and analysis. Consent and retention rates in persons with HF were 37.5% and 100%, respectively. Participants engaged actively in symptom and weight monitoring. Treatment acceptability scores were high. Symptom perception and informal caregivers' contribution to symptom perception were found to be responsive to SYMPERHEART. We estimate that a sample size of 50 persons with HF would be needed for a full-scale effectiveness study.
    Conclusions: SYMPERHEART was found to be feasible and acceptable. This feasibility study provides information for a subsequent effectiveness study.
    Trial registration: ISRCTN. ISRCTN18151041 , retrospectively registered on 4 February 2021, ICTRP Search Portal.
    Language English
    Publishing date 2023-10-04
    Publishing country England
    Document type Journal Article
    ZDB-ID 2809935-7
    ISSN 2055-5784
    ISSN 2055-5784
    DOI 10.1186/s40814-023-01390-3
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  8. Article ; Online: Modeling and Predicting the Short‐Term Evolution of the Geomagnetic Field

    Baerenzung, J. / Holschneider, M. / Wicht, J. / Sanchez, S. / Lesur, V.

    Journal of Geophysical Research

    2018  

    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Conference proceedings ; Online: Diffusive processes and Earth’s magnetic field changes

    Wardinski, I. / Wicht, J.

    12th IAGA Scientific Assembly (Merida, Mexico 2013)

    2013  

    Keywords 550 - Earth sciences
    Publishing country de
    Document type Conference proceedings ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Müller matrix polarimetry for pancreatic tissue characterization.

    Sampaio, Paulo / Lopez-Antuña, Maria / Storni, Federico / Wicht, Jonatan / Sökeland, Greta / Wartenberg, Martin / Márquez-Neila, Pablo / Candinas, Daniel / Demory, Brice-Olivier / Perren, Aurel / Sznitman, Raphael

    Scientific reports

    2023  Volume 13, Issue 1, Page(s) 16417

    Abstract: Polarimetry is an optical characterization technique capable of analyzing the polarization state of light reflected by materials and biological samples. In this study, we investigate the potential of Müller matrix polarimetry (MMP) to analyze fresh ... ...

    Abstract Polarimetry is an optical characterization technique capable of analyzing the polarization state of light reflected by materials and biological samples. In this study, we investigate the potential of Müller matrix polarimetry (MMP) to analyze fresh pancreatic tissue samples. Due to its highly heterogeneous appearance, pancreatic tissue type differentiation is a complex task. Furthermore, its challenging location in the body makes creating direct imaging difficult. However, accurate and reliable methods for diagnosing pancreatic diseases are critical for improving patient outcomes. To this end, we measured the Müller matrices of ex-vivo unfixed human pancreatic tissue and leverage the feature-learning capabilities of a machine-learning model to derive an optimized data representation that minimizes normal-abnormal classification error. We show experimentally that our approach accurately differentiates between normal and abnormal pancreatic tissue. This is, to our knowledge, the first study to use ex-vivo unfixed human pancreatic tissue combined with feature-learning from raw Müller matrix readings for this purpose.
    MeSH term(s) Humans ; Diagnostic Imaging/methods ; Spectrum Analysis
    Language English
    Publishing date 2023-09-29
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-023-43195-7
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