Oceanus.

v. 38, no.1 (1995

Remote refocusing light-sheet fluorescence microscopy for high-speed 2D and 3D imaging of calcium dynamics in cardiomyocytes

The high prevalence and poor prognosis of heart failure are two key drivers for research into cardiac electrophysiology and regeneration. Dyssynchrony in calcium release and loss of structural organization within individual cardiomyocytes (CM) has been linked to reduced contractile strength and arrhythmia. Correlating calcium dynamics and cell microstructure requires multidimensional imaging with high spatiotemporal resolution. In light-sheet fluorescence microscopy (LSFM), selective plane illumination enables fast optically sectioned imaging with lower phototoxicity, making it suitable for imaging subcellular dynamics. In this work, a custom remote refocusing LSFM system is applied to studying calcium dynamics in isolated CM, cardiac cell cultures and tissue slices. The spatial resolution of the LSFM system was modelled and experimentally characterized. Simulation of the illumination path in Zemax was used to estimate the light-sheet beam waist and confocal parameter. Automated MATLAB-based image analysis was used to quantify the optical sectioning and the 3D point spread function using Gaussian fitting of bead image intensity distributions. The results demonstrated improved and more uniform axial resolution and optical sectioning with the tighter focused beam used for axially swept light-sheet microscopy. High-speed dual-channel LSFM was used for 2D imaging of calcium dynamics in correlation with the t-tubule structure in left and right ventricle cardiomyocytes at 395 fps. The high spatio-temporal resolution enabled the characterization of calcium sparks. The use of para-nitro-blebbistatin (NBleb), a non-phototoxic, low fluorescence contraction uncoupler, allowed 2D-mapping of the spatial dyssynchrony of calcium transient development across the cell. Finally, aberration-free remote refocusing was used for high-speed volumetric imaging of calcium dynamics in human induced pluripotent stem-cell derived cardiomyocytes (hiPSC-CM) and their co-culture with adult-CM. 3D-imaging at up to 8 Hz demonstrated the synchronization of calcium transients in co-culture, with increased coupling with longer co-culture duration, uninhibited by motion uncoupling with NBleb.Open Acces

KOLAM : human computer interfaces fro visual analytics in big data imagery

In the present day, we are faced with a deluge of disparate and dynamic information from multiple heterogeneous sources. Among these are the big data imagery datasets that are rapidly being generated via mature acquisition methods in the geospatial, surveillance (specifically, Wide Area Motion Imagery or WAMI) and biomedical domains. The need to interactively visualize these imagery datasets by using multiple types of views (as needed) into the data is common to these domains. Furthermore, researchers in each domain have additional needs: users of WAMI datasets also need to interactively track objects of interest using algorithms of their choice, visualize the resulting object trajectories and interactively edit these results as needed. While software tools that fulfill each of these requirements individually are available and well-used at present, there is still a need for tools that can combine the desired aspects of visualization, human computer interaction (HCI), data analysis, data management, and (geo-)spatial and temporal data processing into a single flexible and extensible system. KOLAM is an open, cross-platform, interoperable, scalable and extensible framework for visualization and analysis that we have developed to fulfil the above needs. The novel contributions in this thesis are the following: 1) Spatio-temporal caching for animating both giga-pixel and Full Motion Video (FMV) imagery, 2) Human computer interfaces purposefully designed to accommodate big data visualization, 3) Human-in-the-loop interactive video object tracking - ground-truthing of moving objects in wide area imagery using algorithm assisted human-in-the-loop coupled tracking, 4) Coordinated visualization using stacked layers, side-by-side layers/video sub-windows and embedded imagery, 5) Efficient one-click manual tracking, editing and data management of trajectories, 6) Efficient labeling of image segmentation regions and passing these results to desired modules, 7) Visualization of image processing results generated by non-interactive operators using layers, 8) Extension of interactive imagery and trajectory visualization to multi-monitor wall display environments, 9) Geospatial applications: Providing rapid roam, zoom and hyper-jump spatial operations, interactive blending, colormap and histogram enhancement, spherical projection and terrain maps, 10) Biomedical applications: Visualization and target tracking of cell motility in time-lapse cell imagery, collecting ground-truth from experts on whole-slide imagery (WSI) for developing histopathology analytic algorithms and computer-aided diagnosis for cancer grading, and easy-to-use tissue annotation features.Includes bibliographical reference

Air Force Institute of Technology Research Report 2016

This Research Report presents the FY16 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs)

Effectiveness of time-lapse videos as a method to teach rates of surface geological processes

Understanding the wide range of rates at which geological processes operate can be challenging for introductory geology students, and yet is crucial to understanding how the Earth’s landscapes evolve over time. Research has shown that student misconceptions in this area are common. Time-lapse videos can capture processes that cannot be observed by students in the field and offer promise as a way to improves student understanding of rates of landscape evolution on certain timescales. This thesis explores the effectiveness of using time-lapse videos to teach intro geology students about the rates of surficial geological processes compared to before/after photo pairs depicting the same processes. The effect of interactivity on the effectiveness of time-lapse is also explored. One hundred and thirty students enrolled in introductory geology classes at Western Washington University during Winter and Spring quarter 2014 participated in the study. Subjects took a pre-test where they made qualitative and quantitative predictions about how various landscapes would change over time before completing a series of computer based activities containing before/after photos or time-lapse videos and then a post-test allowing them to revisit their predictions. The performance of three treatment groups, one using before/after photo pairs, one using pre-made time-lapse videos, and one where students made their own custom time-lapse videos using an interactive online program, was compared. All three groups exhibited large and statistically significant gains in understanding of geologic rates as measured by score gain from pre-test to post-test although differences in gains between groups were small and not significant. A number of steps were taken during study design and data analysis to ensure construct and internal validity. Lack of significant differences in the performance of the three treatment groups on the assessments suggests that there may be cognitive barriers to processing the complex and rapid landscape changes presented in a time-lapse video. This may limit how much students, in particular novice geology students, can learn from time-lapse videos, even though they inherently present more information and a more complete picture of a given geological process as compared to before/after photo pairs. The results of the study suggest various ways to improve the implementation and effectiveness of time-lapse videos in the geology classroom, including decreasing frame rates, more guidance on what to focus on when viewing time-lapse videos, inclusion of annotation and/or narration in the videos themselves, more time to look at the videos, and better integration of the videos and assessment questions. Extra care is also needed to ensure that videos explicitly address pre-existing misconceptions held by viewers in order for them to be effective with a wide range of students

The Decision to Evacuate a Passenger Ship - An Assessment of the Normative View of the Shipmaster

The shipmaster is the centralised focal point of power on a passenger ship, and upon him/her rests the decision to evacuate the ship if it is deemed to be in a situation that is non-survivable. This thesis set out to explore a societal normative view of the shipmaster in this decision space; a view that can be observed in accident reports and maritime legislation. A case study, of a government accident report about the foundering of a large passenger ship and data collected by interviews with active passenger ship shipmasters, has shed light on the validity of that societal view. It was found that the owner’s mercantile interests and control of risk, and the society’s demand for safety for the citizens, which is exerted through the SMS and legislation, necessitates a view of the shipmaster as a rational autonomous agent with legitimized power to secure positive outcomes. In contrast, it was also found that different applications of power co-exist and are not excluding each other, but are on the contrary supplementary and co-dependent for constituting the shipmaster’s position of power, while at the same time subverting the shipmaster hierarchal position of power. In a reluctance to dissolve his power the shipmaster is not facing a go or no-go situation. Instead, the shipmaster is applying a decision strategy of gradually collecting enough information to make an informed decision, while seeking alternative solutions to the emergency situation, which challenges his ableness to secure a positive outcome. These findings supported a hypothesis that assumed that the shipmaster’s place in an authoritarian hierarchy brings about a view of the shipmaster as person with rational decision-making capability and power to secure certain outcomes. Furthermore, the findings indicate that the validity of the normative view of the shipmaster can be brought into question

ORYX 2.0: A Planetary Exploration Mobility Platform

This project involved the design, manufacturing, integration, and testing of ORYX 2.0, a modular mobility platform. ORYX 2.0 is a rover designed for operation on rough terrain to facilitate space related technology research and Earth exploration missions. Currently there are no low-cost rovers available to academia or industry, making it difficult to conduct research related to surface exploration. ORYX 2.0 fills this gap by serving as a ruggedized highly mobile research platform with many features aimed at simplifying payload integration. Multiple teleoperated field testing trials on a variety of terrains validated the rover’s ruggedness and ability to operate soundly. Lastly, a deployable pan-tilt camera was designed, built, and tested, as an example payload

ORYX 2.0: A Planetary Exploration Mobility Platform

This project involved the design, manufacturing, integration, and testing of ORYX 2.0, a modular mobility platform. ORYX 2.0 is a rover designed for operation on rough terrain to facilitate space related technology research and Earth exploration missions. Currently there are no low-cost rovers available to academia or industry, making it difficult to conduct research related to surface exploration. ORYX 2.0 fills this gap by serving as a ruggedized highly mobile research platform with many features aimed at simplifying payload integration. Multiple teleoperated field testing trials on a variety of terrains validated the rover\u27s ruggedness and ability to operate soundly. Lastly, a deployable pan-tilt camera was designed, built, and tested, as an example payload

Control, guidance, and navigation for advanced manned missions. Volume 3 - Radiation sensor systems Final report

Development of radiation sensor subsystems for advanced manned space mission