scholarly journals Light sheet based volume flow cytometry (VFC) for rapid volume reconstruction and parameter estimation on the go

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Prashant Kumar ◽  
Prakash Joshi ◽  
Jigmi Basumatary ◽  
Partha Pratim Mondal

AbstractOptical imaging is paramount for disease diagnosis and to access its progression over time. The proposed optical flow imaging (VFC/iLIFE) is a powerful technique that adds new capabilities (3D volume visualization, organelle-level resolution, and multi-organelle screening) to the existing system. Unlike state-of-the-art point-illumination-based biomedical imaging techniques, the sheet-based VFC technique is capable of single-shot sectional visualization, high throughput interrogation, real-time parameter estimation, and instant volume reconstruction with organelle-level resolution of live specimens. The specimen flow system was realized on a multichannel (Y-type) microfluidic chip that enables visualization of organelle distribution in several cells in-parallel at a relatively high flow-rate (2000 nl/min). The calibration of VFC system requires the study of point emitters (fluorescent beads) at physiologically relevant flow-rates (500–2000 nl/min) for determining flow-induced optical aberration in the system point spread function (PSF). Subsequently, the recorded raw images and volumes were computationally deconvolved with flow-variant PSF to reconstruct the cell volume. High throughput investigation of the mitochondrial network in HeLa cancer cell was carried out at sub-cellular resolution in real-time and critical parameters (mitochondria count and size distribution, morphology, entropy, and cell strain statistics) were determined on-the-go. These parameters determine the physiological state of cells, and the changes over-time, revealing the metastatic progression of diseases. Overall, the developed VFC system enables real-time monitoring of sub-cellular organelle organization at a high-throughput with high-content capacity.

2020 ◽  
Author(s):  
Prashant Kumar ◽  
Prakash Joshi ◽  
Jigmi Basumatary ◽  
Partha Pratim Mondal

Cell screening and viability studies are paramount to access cell morphology and intracellular molecular variations within large heterogeneous populations of cells. This forms the basis for diagnosis of infections, evaluating immunohistochemistry and routine histopathology. The proposed volume flow cytometry (also termed as, parallel Integrated Light-sheet imaging and flow-based enquiry (parallel-iLIFE)) is a powerful method that adds new capabilities (3D volume visualization, organelle-level resolution and multi-organelle screening) powered by light sheet based illumination. Unlike state-of-the-art point-illumination based imaging cytometry techniques, light sheet based parallel-iLIFE technique is capable of screening species with high throughput and near diffraction-limited resolution. The flow system was realized on a multichannel (Y-type) microfluidic chip that enables visualization of mitochondrial network of several cells in-parallel at a relatively high flow-rate of 2000 nl/min. The calibration of system requires study of point emitters (fluorescent beads) at physiologically relevant flow-rates (50−2000 nl/min) for determining flow-induced optical aberration in the system point spread function (PSF). Subsequently, recorded raw images and volumes were deconvolved with flow-variant PSF to reconstruct cellular mitochondrial network. High throughput investigation of HeLa cells were carried out at sub-cellular resolution in real-time and critical parameters (mitochondria count and size distribution, morphology and cell strain statistics) are determined on-the-go. These parameters determine the physiological state of cells and the changes in mitochondrial distribution over-time that may have consequences in disease diagnosis. The development of volume flow cytometry system (parallel-iLIFE) and its suitability to study sub-cellular components at high-throughput high-content capacity with organelle-level resolution may enable disease diagnosis on a single microfluidic chip.


2021 ◽  
Author(s):  
Carolina Nunes ◽  
Jasper Anckaert ◽  
Fanny De Vloed ◽  
Jolien De Wyn ◽  
Kaat Durinck ◽  
...  

Biomedical researchers are moving towards high-throughput screening, as this allows for automatization, better reproducibility and more and faster results. High-throughput screening experiments encompass drug, drug combination, genetic perturbagen or a combination of genetic and chemical perturbagen screens. These experiments are conducted in real-time assays over time or in an endpoint assay. The data analysis consists of data cleaning and structuring, as well as further data processing and visualisation, which, due to the amount of data, can easily become laborious, time consuming, and error-prone. Therefore, several tools have been developed to aid researchers in this data analysis, but they focus on specific experimental set-ups and are unable to process data of several time points and genetic-chemical perturbagen screens together. To meet these needs, we developed HTSplotter, available as web tool and Python module, that performs automatic data analysis and visualisation of either endpoint or real-time assays from different high-throughput screening experiments: drug, drug combination, genetic perturbagen and genetic-chemical perturbagen screens. HTSplotter implements an algorithm based on conditional statements in order to identify experiment type and controls. After appropriate data normalization, HTSplotter executes downstream analyses such as dose-response relationship and drug synergism by the Bliss independence method. All results are exported as a text file and plots are saved in a PDF file. The main advantage of HTSplotter over other available tools is the automatic analysis of genetic-chemical perturbagen screens and real-time assays where results are plotted over time. In conclusion, HTSplotter allows for the automatic end-to-end data processing, analysis and visualisation of various high-throughput in vitro cell culture screens, offering major improvements in terms of versatility, convenience and time over existing tools.


Author(s):  
Balaji G V

Object Detection using SSD (Single Shot Detector) and MobileNets are efficient because this technique detects objects quickly with less resourses without sacrificing performance. In this every class of item for which the classification algorithm has been trained generates a bounding box and an annotation describing that class of object. This provides the foundation for creating several types of analytical features such as the volume of traffic in a certain area over time or the entire population in an area is real-time detection and categorization of objects from video data.


Author(s):  
Jenni Myllykoski ◽  
Anniina Rantakari

This chapter focuses on temporality in managerial strategy making. It adopts an ‘in-time’ view to examine strategy making as the fluidity of the present experience and draws on a longitudinal, real-time study in a small Finnish software company. It shows five manifestations of ‘in-time’ processuality in strategy making, and identifies a temporality paradox that arises from the engagement of managers with two contradictory times: constructed linear ‘over time’ and experienced, becoming ‘in time’. These findings lead to the re-evaluation of the nature of intention in strategy making, and the authors elaborate the constitutive relation between time as ‘the passage of nature’ and human agency. Consequently, they argue that temporality should not be treated merely as an objective background or a subjective managerial orientation, but as a fundamental characteristic of processuality that defines the dynamics of strategy making.


Author(s):  
Xiaojia Jiang ◽  
Mingsong Zang ◽  
Fei Li ◽  
Chunxi Hou ◽  
Quan Luo ◽  
...  

Biological nanopore-based techniques have attracted more and more attention recently in the field of single-molecule detection, because they allow the real-time, sensitive, high-throughput analysis. Herein, we report an engineered biological...


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrew T. Meek ◽  
Nils M. Kronenberg ◽  
Andrew Morton ◽  
Philipp Liehm ◽  
Jan Murawski ◽  
...  

AbstractImportant dynamic processes in mechanobiology remain elusive due to a lack of tools to image the small cellular forces at play with sufficient speed and throughput. Here, we introduce a fast, interference-based force imaging method that uses the illumination of an elastic deformable microcavity with two rapidly alternating wavelengths to map forces. We show real-time acquisition and processing of data, obtain images of mechanical activity while scanning across a cell culture, and investigate sub-second fluctuations of the piconewton forces exerted by macrophage podosomes. We also demonstrate force imaging of beating neonatal cardiomyocytes at 100 fps which reveals mechanical aspects of spontaneous oscillatory contraction waves in between the main contraction cycles. These examples illustrate the wider potential of our technique for monitoring cellular forces with high throughput and excellent temporal resolution.


2021 ◽  
pp. 216770262096629
Author(s):  
Grace M. Brennan ◽  
Arielle Baskin-Sommers

Physically aggressive individuals are more likely to decide that others are threatening. Yet no research has examined how physically aggressive individuals’ social decisions unfold in real time. Seventy-five incarcerated men completed a task in which they identified the emotions in faces displaying anger (i.e., threat) and happiness (i.e., nonthreat) at low, moderate, or high ambiguity. Participants then rated their confidence in their decisions either immediately or after a delay, and changes in confidence provided an index of postdecisional processing. Physical aggression was associated with stronger differentiation of threatening and nonthreatening faces under moderate ambiguity. Moreover, physical aggression was associated with steeper decreases in confidence over time following decisions that threatening faces were nonthreatening, indicating more extensive postdecisional processing. This pattern of postdecisional processing mediated the association between physical aggression and angry rumination. Findings suggest a role for postdecisional processing in the maintenance of threat-based social decisions in physical aggression.


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