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Radio occultation observations of the solar corona over 1.60-1.86R⊙: Faraday rotation and frequency-shift analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-02)
The study of coronal energy transport, central to the solar wind acceleration problem, relies upon accurate representation of magnetic fields and plasma electron densities. This information is difficult to obtain in middle‐to‐lower coronal regions that may contain complex magnetic structures. Faraday rotation (FR) solar radio occultation observations, which reveal line‐of‐sight (LOS) integrated ...
Super-condenser enables labelfree nanoscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-22)
Labelfree nanoscopy encompasses optical imaging with resolution in the 100 nm range using visible wavelengths. Here, we present a labelfree nanoscopy method that combines coherent imaging techniques with waveguide microscopy to realize a <i>super-condenser</i> featuring maximally inclined coherent darkfield illumination with artificially stretched wave vectors due to large refractive indices of the ...
Four dimensional quantification of Kelvin-Helmholtz instabilities in the polar summer mesosphere using volumetric radar imaging
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-13)
We present and characterize in time and three spatial dimensions a Kelvin‐Helmholtz Instability (KHI) event from polar mesospheric summer echoes (PMSE) observed with the Middle Atmosphere Alomar Radar System. We use a newly developed radar imaging mode, which observed PMSE intensity and line of sight velocity with high temporal and angular resolution. The identified KHI event occurs in a narrow layer ...
Deep Reinforcement Learning for Query-Conditioned Video Summarization
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-21)
Query-conditioned video summarization requires to (1) find a diverse set of video shots/frames that are representative for the whole video, and that (2) the selected shots/frames are related to a given query. Thus it can be tailored to different user interests leading to a better personalized summary and differs from the generic video summarization which only focuses on video content. Our work targets ...
Dust trajectory simulations around Sun, Vega, and Fomalhaut
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-20)
<p><i>Context - </i>Vega and Fomalhaut display a thermal emission brightness that can possibly arise from hot dust near the stars, an inner extension of their planetary debris disks. There was brought up an idea that nm-sized dust particles are kept in the vicinity of the stars by electromagnetic forces. This resembles the trapping that model calculations show in the corotating magnetic field in the ...
Synthetic Aperture Radar Remote Sensing of Operational Platform Produced Water Releases
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-03)
Oil spill detection services based on satellite synthetic aperture radar (SAR) frequently detect oil slicks close to platforms due to legal releases of produced water. Separating these slicks from larger releases, e.g., due to accidental leakage is challenging. The aim of this work is to investigate the SAR characteristics of produced water, including the typical appearance in HH/VV data, possible ...
On-Site Ribosome Remodeling by Locally Synthesized Ribosomal Proteins in Axons
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-10)
Ribosome assembly occurs mainly in the nucleolus,
yet recent studies have revealed robust enrichment
and translation of mRNAs encoding many ribosomal
proteins (RPs) in axons, far away from neuronal cell
bodies. Here, we report a physical and functional
interaction between locally synthesized RPs and ribosomes in the axon. We show that axonal RP translation is regulated through a sequence motif, ...
Investigation of exceptionally radar-dark regions on the lunar nearside
(Conference object; Konferansebidrag, 2019-08)
Remote sensing of planetary surfaces is an effective method for gaining knowledge of the processes that
shape the planetary bodies in our solar system. This is useful for uncovering the environment of the primordial solar system and to study the current state of the upper crusts of the other planets in our neighborhood. A recent 6-meter wavelength polarimetric radar map of the Moon [?] showed ...
Super-condenser enables labelfree nanoscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-22)
Labelfree nanoscopy encompasses optical imaging with resolution in the 100 nm range using visible wavelengths. Here, we present a labelfree nanoscopy method that combines coherent imaging techniques with waveguide microscopy to realize a <i>super-condenser</i> featuring maximally inclined coherent darkfield illumination with artificially stretched wave vectors due to large refractive indices of the ...
Radar studies of ionospheric dusty plasma phenomena
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-17)
We discuss the influence of charged dust on radar observations in the Earth ionosphere. This region in the upper Earth atmosphere can be described as a partially ionized, low‐temperature plasma. Plasma parameters vary by orders of magnitude spatially and in time. Dust particles influence the charge balance, in some cases dusty plasma condition is met. The polar mesospheric echoes are an example of ...