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1. A Comparison of Scan Speedup Strategies and Their Effect on Rapid-Scan Weather Radar Data Quality

   https://doi.org/10.1175/JTECH-D-19-0216.1  

   Mahre, Andrew ; Yu, Tian-You ; Bodine, David J. ( November 2020 , Journal of Atmospheric and Oceanic Technology)

   null (Ed.)

   Abstract As the existing NEXRAD network nears the end of its life cycle, intense study and planning are underway to design a viable replacement system. Ideally, such a system would offer improved temporal resolution compared to NEXRAD, without a loss in data quality. In this study, scan speedup techniques—such as beam multiplexing (BMX) and radar imaging—are tested to assess their viability in obtaining high-quality rapid updates for a simulated long-range weather radar. The results of this study—which uses a Weather Research and Forecasting (WRF) Model–simulated supercell case—show that BMX generally improves data quality for a given scan time or can provide a speedup factor of 1.69–2.85 compared to NEXRAD while maintaining the same level of data quality. Additionally, radar imaging is shown to improve data quality and/or decrease scan time when selectively used; however, deleterious effects are observed when imaging is used in regions with sharp reflectivity gradients parallel to the beam spoiling direction. Consideration must be given to the subsequent loss of sensitivity and beam broadening. Finally, imaging is shown to have an effect on the radar-derived mesocyclone strength (Δ V ) of a simulated supercell. Because BMX and radar imaging are most easily achieved with an all-digital phased array radar (PAR), these results make a strong argument for the use of all-digital PAR for high-resolution weather observations. It is believed that the results from this study can inform decisions about possible scanning strategies and design of a NEXRAD replacement system for high-resolution weather radar data. 

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2. Real‐time parallel 3D multiple particle tracking with single molecule centrifugal force microscopy

   https://doi.org/10.1111/jmi.12773  

   KOU, L. ; JIN, L. ; LEI, H. ; HU, C. ; LI, H. ; HU, X. ; HU, X. ( November 2018 , Journal of Microscopy)

   Real‐time tracking of multiple particles is key for quantitative analysis of dynamic biophysical processes and materials science via time‐lapse microscopy image data, especially for single molecule biophysical techniques, such as magnetic tweezers and centrifugal force microscopy. However, real‐time multiple particle tracking with high resolution is limited by the current imaging processes or tracking algorithms. Here, we demonstrate 1 nm resolution in three dimensions in real‐time with a graphics‐processing unit (GPU) based on a compute unified device architecture (CUDA) parallel computing framework instead of only a central processing unit (CPU). We also explore the trade‐offs between processing speed and size of the utilized regions of interest and a maximum speedup of 137 is achieved with the GPU compared with the CPU. Moreover, we utilize this method with our recently self‐built centrifugal force microscope (CFM) in experiments that track multiple DNA‐tethered particles. Our approach paves the way for high‐throughput single molecule techniques with high resolution and efficiency.

   Particles are widely used as probes in life sciences through their motions. In single molecule techniques such as optical tweezers and magnetic tweezers, microbeads are used to study intermolecular or intramolecular interactions via beads tracking. Also tracking multiple beads’ motions could study cell–cell or cell–ECM interactions in traction force microscopy. Therefore, particle tracking is of key important during these researches. However, parallel 3D multiple particle tracking in real‐time with high resolution is a challenge either due to the algorithm or the program. Here, we combine the performance of CPU and CUDA‐based GPU to make a hybrid implementation for particle tracking. In this way, a speedup of 137 is obtained compared the program before only with CPU without loss of accuracy. Moreover, we improve and build a new centrifugal force microscope for multiple single molecule force spectroscopy research in parallel. Then we employed our program into centrifugal force microscope for DNA stretching study. Our results not only demonstrate the application of this program in single molecule techniques, also indicate the capability of multiple single molecule study with centrifugal force microscopy.

    

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3. Magnetic Relaxation Seen in a Rapidly Evolving Light Bridge in a Sunspot

   https://doi.org/10.3847/1538-4357/ad1ab0  

   Song, Donguk ; Lim, Eun-Kyung ; Chae, Jongchul ; Kim, Yeon-Han ; Katsukawa, Yukio ; Yurchyshyn, Vasyl ( February 2024 , The Astrophysical Journal)

   We report a magnetic relaxation process inside a sunspot associated with the evolution of a transient light bridge (LB). From high-resolution imaging and spectro-polarimetric data taken by the 1.6 m Goode Solar Telescope installed at Big Bear Solar Observatory, we observe the evolutionary process of a rapidly evolving LB. The LB is formed as a result of the strong intrusion of filamentary structures with relatively horizontal fields into the vertical umbral field region. A strong current density is detected along a localized region where the magnetic field topology changes rapidly in the sunspot, especially in the boundary region between the LB and the umbra, and bright jets are observed intermittently and repeatedly in the chromosphere along this region through magnetic reconnection. In the second half of our observation, the horizontal component of the magnetic field diminishes within the LB, and the typical convection structure within the sunspot, which manifests itself as umbral dots, is restored. Our findings provide a comprehensive perspective not only on the evolution of an LB itself but also on its impacts in the neighboring regions, including the chromospheric activity and the change of magnetic energy of a sunspot.

    

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4. Spectral illumination system utilizing spherical reflection optics

   https://doi.org/10.1117/12.2546395  

   Gunn Mayes, Samantha ; Browning, Craig M. ; Mayes, Samuel A. ; Parker, Marina ; Rich, Thomas C. ; Leavesley, Silas J. ; Farkas, Daniel L. ; Leary, James F. ; Tarnok, Attila ( February 2020 , Proc. SPIE 11243, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XVIII)

   Fluorescence imaging microscopy has traditionally been used because of the high specificity that is achievable through fluorescence labeling techniques and optical filtering. When combined with spectral imaging technologies, fluorescence microscopy can allow for quantitative identification of multiple fluorescent labels. We are working to develop a new approach for spectral imaging that samples the fluorescence excitation spectrum and may provide increased signal strength. The enhanced signal strength may be used to provide increased spectral sensitivity and spectral, spatial, and temporal sampling capabilities. A proof of concept excitation scanning system has shown over 10-fold increase in signal to noise ratio compared to emission scanning hyperspectral imaging. Traditional hyperspectral imaging fluorescence microscopy methods often require minutes of acquisition time. We are developing a new configuration that utilizes solid state LEDs to combine multiple illumination wavelengths in a 2-mirror assembly to overcome the temporal limitations of traditional hyperspectral imaging. We have previously reported on the theoretical performance of some of the aspects of this system by using optical ray trace modeling. Here, we present results from prototyping and benchtop testing of the system, including assembly, optical characterization, and data collection. This work required the assembly and characterization of a novel excitation scanning hyperspectral microscopy system, containing 12 LEDs ranging from 365- 425 nm, 12 lenses, a spherical mirror, and a flat mirror. This unique approach may reduce the long image acquisition times seen in traditional hyperspectral imaging while maintaining high specificity and sensitivity for multilabel identification and autofluorescence imaging in real time. 

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5. Life cycle based alternatives assessment (LCAA) for chemical substitution

   https://doi.org/10.1039/d0gc01544j  

   Fantke, Peter ; Huang, Lei ; Overcash, Michael ; Griffing, Evan ; Jolliet, Olivier ( September 2020 , Green Chemistry)

   null (Ed.)

   The world faces an increasing need to phase out harmful chemicals and design sustainable alternatives across various consumer products and industrial applications. Alternatives assessment is an emerging field with focus on identifying viable solutions to substitute harmful chemicals. However, current methods fail to consider trade-offs from human and ecosystem exposures, and from impacts associated with chemical supply chains and product life cycles. To close this gap, we propose a life cycle based alternatives assessment (LCAA) framework for consistently integrating quantitative exposure and life cycle impact performance in the substitution process. We start with a pre-screening based on function-related decision rules, followed by three progressive tiers from (1) rapid risk screening of various alternatives for the consumer use stage, to (2) an assessment of chemical supply chain impacts for selected alternatives with substantially different synthesis routes, and (3) an assessment of product life cycle impacts for alternatives with substantially different product life cycles. Each tier focuses on relevant impacts and uses streamlined assessment methods. While the initial risk screening will be sufficient for evaluating chemicals with similar supply chains, each additional tier helps further restricting the number of viable solutions, while avoiding unacceptable trade-offs. We test our LCAA framework in a proof-of-concept case study for identifying suitable alternatives to a harmful plasticizer in household flooring. Results show that the use stage dominates human health impacts across alternatives, supporting that a rapid risk screening is sufficient unless very different supply chains or a broader set of alternative materials or technologies are considered. Combined with currently used indicators for technical and economic performance, our LCAA framework is suitable for informing function-based substitution at the level of chemicals, materials and product applications to foster green and sustainable chemistry solutions. 

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