Synthetic Aperture Radar (SAR) is widely used in oceanic eddies research. High-resolution SAR images should be useful in revealing eddy features and investigating the eddy imaging mechanism. However, SAR imaging is affected by various radar parameters and environmental factors, which makes it quite difficult to learn directly from SAR eddy images. In order to interpret and evaluate eddy images, developing a proper simulation method is necessary. However, seldom has a SAR simulation method for oceanic eddies, especially for shear-wave-generated eddies, been established. As a step forward, we propose a simulation method for oceanic shear-wave-generated eddies. The Burgers-Rott vortex model is used to specify the surface current field of the simulated eddies. Images are then simulated for a range of different radar frequencies, radar look directions, wind speeds, and wind directions. The results show that the simulated images are consistent with actual SAR images. The effects of different radar parameters and wind fields on SAR eddy imaging are analyzed by qualitative and quantitative methods. Overall, the simulated images produce a surface pattern and brightness variations with characteristics resembling actual SAR images of oceanic eddies.
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http://dx.doi.org/10.3390/s19071529 | DOI Listing |
Extremophiles
January 2025
Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India.
To fish-out novel salt-tolerance genes, metagenomic DNA of moderately saline sediments of India's largest hypersaline Sambhar Lake was cloned in fosmid. Two functionally-picked clones helped the Escherichia coli host to tolerate 0.6 M NaCl.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemistry, Imperial College London Molecular Sciences Research Hub, 82 Wood Lane, White City Campus London W12 0BZ UK
The blood-brain-barrier prevents many imaging agents and therapeutics from being delivered to the brain that could fight central nervous system diseases such as Alzheimer's disease and strokes. However, techniques such as the use of stapled peptides or peptide shuttles may allow payloads through, with bioconjugation achieved bio-orthogonal tetrazine/norbornene click chemistry. A series of lanthanide-tetrazine probes have been synthesised herein which could be utilised in bio-orthogonal click chemistry with peptide-based delivery systems to deliver MRI agents through the blood-brain-barrier.
View Article and Find Full Text PDFSmall
January 2025
School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Fluorescent light-up aptamer/fluorogen pairs are powerful tools for tracking RNA in the cell, however limitations in thermostability and fluorescence intensity exist. Current in vitro selection techniques struggle to mimic complex intracellular environments, limiting in vivo biomolecule functionality. Taking inspiration from microenvironment-dependent RNA folding observed in cells and organelle-mimicking droplets, an efficient system is created that uses microscale heated water droplets to simulate intracellular conditions, effectively replicating the intracellular RNA folding landscape.
View Article and Find Full Text PDFSci Rep
January 2025
School of Transportation and Geometics Engineering, Yangling Vocational & Technical College, Yangling, 712100, Shaanxi, China.
This work aims to improve the accuracy and efficiency of flood disaster monitoring, including monitoring before, during, and after the flood, to achieve accurate extraction of flood disaster change information. A modified U-Net network model, incorporating the Transformer multi-head attention mechanism (TM), is developed specifically for the characteristics of Synthetic Aperture Radar (SAR) images. By integrating the TM, the model effectively prioritizes image regions relevant to flood disasters.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory for Extreme Photonics and Instrumentation, International Research Center for Advanced Photonics, Ningbo Innovation Center, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310058, China.
The frequency-modulated continuous-wave (FMCW) technology combined with optical phased array (OPA) is promising for the all-solid-state light detection and ranging (LiDAR). We propose and experimentally demonstrate a silicon integrated OPA combined with an optical frequency microcomb for parallel LiDAR system. For realizing the parallel wavelengths emission consistent with Rayleigh criterion, the wide waveguide beyond single mode region combined with the bound state in the continuum (BIC) effect is harnessed to obtain an ultra-long optical grating antenna array.
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