88 research outputs found
Pattern of cryospheric seismic events observed at Ekström ice shelf, Antarctica
Mobility of glaciers such as rapid retreat or disintegration of large ice volumes produces a large variety of different seismic signals. Thus, evaluating cryospheric seismic events (e.g. changes of their occurrence in space and time)allows to monitor glacier dynamics. We analyze a one year data span recorded
at the Neumayer seismic network in Antarctica. Events are automatically recognized using hidden Markov models. In this study we focused on a specifc event type occurring close to the grounding line of the Ekström ice shelf. Observed waveform characteristics are consistent with an initial fracturing followed by the resonance of a water filled cavity resulting in a so-called hybrid event. The number of events detected strongly correlates with dominant tide periods. We assume the cracking to be driven by existing glacier stresses through bending. Voids are then filled by sea water, exciting the observed resonance. In agreement with this model, events occur almost exclusively during rising tides where cavities are opened at the bottom of the glacier, i.e. at the sea/ice interface
Shape Tailored Magnetic Nanorings for Intracellular Hyperthermia Cancer Therapy
This work explores a new class of vortex/magnetite/iron oxide nanoparticles designed for magnetic hyperthermia applications. These nanoparticles, named Vortex Iron oxide Particles (VIPs), are an alternative to the traditional Superparamagnetic Iron Oxide Nanoparticles (SPIONs), since VIPs present superior heating power while fulfilling the main requirements for biomedical applications (low cytotoxicity and nonremanent state). In addition, the present work demonstrates that the synthesized VIPs also promote an internalization and aggregation of the particles inside the cell, resulting in a highly localized hyperthermia in the presence of an alternating magnetic field. Thereby, we demonstrate a new and efficient magnetic hyperthermia strategy in which a small, but well localized, concentration of VIPs can promote an intracellular hyperthermia process
Impurity temperatures measured via line shape analysis in the island scrape-off-layer of Wendelstein 7-X
Impurity temperatures have been determined by a spectroscopic line shape analysis for several species in the divertor scrape-off-layer of the stellarator Wendelstein 7-X (W7-X). Examples include spectral lines from intrinsic elements (C II and C III, He I) as well as from seeded impurities (Ar II, N II) through the divertor gas inlet system. Both Doppler broadening and Zeeman splitting are found to contribute significantly to the impurity line shapes. Zeeman splitting arises due to the confining magnetic field in W7-X and complicates the line shape appearance. By attributing Doppler widths to each of the various Zeeman components, however, we demonstrate that reliable ion temperature values can be derived provided that the presence of the magnetic field is properly accounted for. The spectrally highly resolved lines are analyzed by means of a multi-parameter, least-squares fit routine, which accounts for Doppler broadening, Zeeman splitting, as well as the instrumental broadening of the spectrometer used to measure the spectral line shapes. By spectral fitting of the Zeeman features, it is also found that the line shape analysis can yield values for the local magnetic field, which can be used to localize the impurity radiation approximately provided that the line emission is dominant in a small area intersected by the lines of sight of the spectrometer
Application of the elliptic approximation model for the edge turbulence rotation measurement via the poloidal correlation reflectometer in Wendelstein 7-X
Benchmark datasets for 3D MALDI- and DESI-imaging mass spectrometry
BACKGROUND: Three-dimensional (3D) imaging mass spectrometry (MS) is an analytical chemistry technique for the 3D molecular analysis of a tissue specimen, entire organ, or microbial colonies on an agar plate. 3D-imaging MS has unique advantages over existing 3D imaging techniques, offers novel perspectives for understanding the spatial organization of biological processes, and has growing potential to be introduced into routine use in both biology and medicine. Owing to the sheer quantity of data generated, the visualization, analysis, and interpretation of 3D imaging MS data remain a significant challenge. Bioinformatics research in this field is hampered by the lack of publicly available benchmark datasets needed to evaluate and compare algorithms. FINDINGS: High-quality 3D imaging MS datasets from different biological systems at several labs were acquired, supplied with overview images and scripts demonstrating how to read them, and deposited into MetaboLights, an open repository for metabolomics data. 3D imaging MS data were collected from five samples using two types of 3D imaging MS. 3D matrix-assisted laser desorption/ionization imaging (MALDI) MS data were collected from murine pancreas, murine kidney, human oral squamous cell carcinoma, and interacting microbial colonies cultured in Petri dishes. 3D desorption electrospray ionization (DESI) imaging MS data were collected from a human colorectal adenocarcinoma. CONCLUSIONS: With the aim to stimulate computational research in the field of computational 3D imaging MS, selected high-quality 3D imaging MS datasets are provided that could be used by algorithm developers as benchmark datasets
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