Simultaneous multiple-level magnification selective plane illumination microscopy (sMx-SPIM) imaging system

We report an optical-based (microscopy) imaging technology – Simultaneous Multiple-level Magnification Selective Plane Illumination Microscopy (sMx-SPIM) Imaging System – that addresses a longstanding (technological) challenge of obtaining images, specifically of the biological specimen non-destructively, at different fields of view (FOV) and spatial resolutions (or magnification powers) simultaneously in real-time. Thus, this imaging system provides not only 3D images but also time-resolved sequential images with temporal resolution msecs. Magnification powers (or FOVs) of the individual images can be controlled independently that can be achieved by housing two separate detection arms, in SPIM imaging system, fitted with objective lenses of different magnification powers. These unique features hold promises to observe and study of: (i) sub-microscopic details and entire structure of biological specimen side-by-side simultaneously and (ii) spatio-temporal dynamics of functional activities of biological specimen. For validation study of robustness of the proposed sMx-SPIM imaging system, experiments are conducted in various biological samples (zebrafish embryo, Drosophila melanogaster, and Allium cepa root). Experimental results demonstrate that the study is of significant impacts from two aspects (technological and biological applications).

Mapping Diurnal Variability of the Wintertime Pearl River Plume Front from Himawari-8 Geostationary Satellite Observations

the spatial pattern of the wintertime Pearl River plume front (PRPF), and its variability on diurnal and spring-neap time scales are characterized from the geostationary meteorological Himawari-8 satellite, taking advantage of the satellite’s unique 10-minutely sea surface temperature sequential images. Our findings suggest that the PRPF in winter consists of three subfronts: the northern one north of 22°N 20′, the southern one south of 21°N 40′, and the middle one between 22°N 20′ and 21°N 40′. The time-varying trend of the frontal intensity generally exhibits a strong-weak-strong pattern, with the weakest plume front occurring at about 06:00 UTC, which is closely associated with net surface heat flux over the region. The comparison in frontal variability between the spring and neap tides shows that the plume front during the spring tide generally tends to be more diffuse for the frontal probability, move further offshore for the frontal position, and be weaker for the frontal intensity than those found during the neap tide. These great differences largely depend on the tidally induced stronger turbulent mixing during the spring tide while the wind stress only plays a secondary role in the process. To best of our knowledge, the distinct diurnal variations in PRPF with wide coverage are observed for the first time. This study demonstrates that the Himawari-8 geostationary satellite has great potential in characterizing high-frequency surface thermal fronts in considerable detail.

Partial Shape Recognition for Sea Ice Motion Retrieval in the Marginal Ice Zone from Sentinel-1 and Sentinel-2

We present an algorithm for computing ice drift in the marginal ice zone (MIZ), based on partial shape recognition. With the high spatial resolution of Sentinel-1 and Sentinel-2 images, and the low sensitivity to atmospheric influences of Sentinel-1, a considerable quantity of ice floes is identified using a mathematical morphology method. Hausdorff distance is used to measure the similarity of segmented ice floes. It is tolerant to perturbations and deficiencies of floe shapes, which enhances the density of retrieved sea ice motion vectors. The PHD algorithm can be applied to sequential images from different sensors, and was tested on two combined image mosaics consisting of Sentinel-1 and Sentinel-2 data acquired over the Fram Strait; the PHD algorithm successfully produced pairs of matched ice floes. The matching result has been verified using shape and surface texture similarity of the ice floes. Moreover, the present method can naturally be extended to the problem of multi-source sea ice image registration.

Experimental Study of the Quantification of Indocyanine Green Fluorescence in Ischemic and Non-Ischemic Anastomoses, Using the Sergreen Software Program

Background: Tissue ischemia is a key risk factor for anastomotic leakage (AL). Indocyanine green (ICG) is widely used in colorectal surgery to define the segments with the best vascularization. In an experimental model, we present a new system for quantifying ICG saturation, SERGREEN software.Methods: This was a controlled experimental study with eight pigs. In the initial control stage, ICG saturation was analyzed at the level of two anastomoses in the right and left colon. Control images of the two segments were taken after ICG administration. The images were processed with the SERGREEN program. Then, in the experimental ischemia stage, the inferior mesenteric artery was sectioned at the level of the anastomosis of the left colon. Fifteen minutes after the section, sequential images of the two anastomoses were taken every 30’ for the following 2 h.Results: At the control stage, the mean scores were 134.2 (95% CI: 116.3-152.2) for the right colon and 147 (95% CI: 134.7-159.3) for the left colon (p = 0.174). The right colon remained stable throughout the experiment. In the left colon, saturation fell by 47.9 points with respect to the preischemia value (p <0.01). After the first postischemia determination, the values of the ischemic left colon remained stable throughout the experiment. The relative decrease in ICG saturation of the ischemic left colon was 32.6%.Conclusions: The SERGREEN program quantifies ICG saturation in normal and ischemic situations and detects differences between them. A reduction in ICG saturation of 32.6% or more was correlated with complete tissue ischemia.

Quantification of Brownian motion under presence of flow using particle diffusometry

Particle diffusometry (PD), a quantification method for the Brownian motion, is performed by recording temporally sequential images and using correlation analysis to obtain an ensemble diffusion coefficient for all particles captured in the imaging region (Clayton et al., 2017). PD is proven to be successful in the detection of the waterborne pathogen V. cholerae in environmental samples using different imaging techniques, including an inverted fluorescence microscope as well as a handheld hardware device operated with a smartphone (Clayton et al., 2019; Moehling et al., 2020). Although we intend to use PD to calculate diffusion coefficients in quiescent fluid, oftentimes unintentional fluid flows occur, creating measurement error when calculating the diffusion coefficient. In previous work, recordings under the presence of flow were discarded to avoid incorrect measurements of the sample.

Determination of the parameters of suspended particles using acoustic radiation

The flow of a gas or liquid can be visualized by detecting and analyzing sequential images of the particle distribution on the surface of the object under study through the determination of the motion parameters. However, this approach does not provide estimation of the mass and density of solid particles along with visualization of their distribution. We present the results of determining the mass and density of suspended particles using additional irradiation of the particle flux with acoustic radiation. The technique is based on the use of the method of visual processing of images of particle flows entrained by an acoustic field of a given frequency and amplitude for at least two periods of acoustic vibrations. Relaxation of the particles in the measuring plane «cut out» by the light «knife» was also taken into account. The basic mathematical expressions required for estimation of the mass, density, velocity field and shape of the particles using digital image processing and temperature measurement in the flow area are presented. The block diagram and design of the device used for the implementation of the proposed diagnostic method are presented. This technique can be used to determine the parameters of suspended particles in medicine, biology, ecology, powder metallurgy and other fields of science and technology.