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In JoVE (1)
Other Publications (5)
- IEEE Transactions on Image Processing : a Publication of the IEEE Signal Processing Society
- IEEE Transactions on Image Processing : a Publication of the IEEE Signal Processing Society
- Toxicological Sciences : an Official Journal of the Society of Toxicology
- Methods in Molecular Biology (Clifton, N.J.)
- Current Topics in Medicinal Chemistry
Articles by Sabrina Lin in JoVE
JoVE General
Video Bioinformatics Analysis of Human Embryonic Stem Cell Colony Growth
1UCR Stem Cell Center, University of California, 2Department of Cell Biology and Neuroscience, University of California, 3Cell, Molecular, and Developmental Biology Graduate Program, University of California, 4Center for Research in Intelligent Systems, University of California
Video bioinformatics is the automated processing, analysis, understanding, and data mining of biological spatio-temporal data extracted from microscopic videos. The purpose of this article is to demonstrate a method for measuring human embryonic stem cell colony growth using a video bioinformatics method.
Other articles by Sabrina Lin on PubMed
Cooperation Stimulation Strategies for Peer-to-peer Wireless Live Video-sharing Social Networks
Human behavior analysis in video sharing social networks is an emerging research area, which analyzes the behavior of users who share multimedia content and investigates the impact of human dynamics on video sharing systems. Users watching live streaming in the same wireless network share the same limited bandwidth of backbone connection to the Internet, thus, they might want to cooperate with each other to obtain better video quality. These users form a wireless live-streaming social network. Every user wishes to watch video with high quality while paying as little as possible cost to help others. This paper focuses on providing incentives for user cooperation. We propose a game-theoretic framework to model user behavior and to analyze the optimal strategies for user cooperation simulation in wireless live streaming. We first analyze the Pareto optimality and the time-sensitive bargaining equilibrium of the two-person game. We then extend the solution to the multiuser scenario. We also consider potential selfish users' cheating behavior and malicious users' attacking behavior and analyze the performance of the proposed strategies with the existence of cheating users and malicious attackers. Both our analytical and simulation results show that the proposed strategies can effectively stimulate user cooperation, achieve cheat free and attack resistance, and help provide reliable services for wireless live streaming applications.
Risk-distortion Analysis for Video Collusion Attacks: a Mouse-and-cat Game
Copyright protection is a key issue for video sharing over public networks. To protect the video content from unauthorized redistribution, digital fingerprinting is commonly used. To develop an efficient collusion-resistant fingerprinting scheme, it is very important for the system designer to understand how the behavior dynamics of colluders affect the performance of collusion attack. In the literature, little effort has been made to explicitly study the relationship between risk, e.g., the probability of the colluders to be detected, and the distortion of the colluded signal. In this paper, we investigate the risk-distortion relationship for the linear video collusion attack with Gaussian fingerprint. We formulate the optimal linear collusion attack as an optimization problem of finding the optimal collusion parameters to minimize the distortion subject to a risk constraint. By varying the risk constraint and solving the corresponding optimization problem, we can derive the optimal risk-distortion curve. Moreover, based upon the observation that the detector/attacker can each improve the detection/attack performance with the knowledge of his/her opponent's strategy, we formulate the attack and detection problem as a dynamic mouse and cat game and study the optimal strategies for both the attacker and detector. We show that if the detector uses a fixed detection strategy, the attacker can estimate the detector's strategy and choose the corresponding optimal strategy to attack the fingerprinted video with a small distortion. However, if the detector is powerful, i.e., the detector can always estimate the attacker's strategy, the best strategy for the attacker is the min-max strategy. Finally, we conduct several experiments to verify the proposed risk-distortion model using real video data.
Comparison of the Toxicity of Smoke from Conventional and Harm Reduction Cigarettes Using Human Embryonic Stem Cells
This study evaluated the hypothesis that smoke from harm reduction cigarettes impedes attachment and proliferation of H9 human embryonic stem cells (hESCs). Smoke from three harm reduction brands was compared with smoke from a conventional brand. Doses of smoke were measured in puff equivalents (PE) (1 PE = the amount of smoke in one puff that dissolves in 1 ml of medium). Cytotoxic doses were determined using morphological criteria and trypan blue staining, and apoptosis was confirmed using Magic Red staining. Attachment and proliferation of hESC were followed at a noncytotoxic dose in time-lapse videos collected using BioStation technology. Data were mined from videos either manually or using video bioinformatics subroutines developed with CL-Quant software. Mainstream (MS) and sidestream (SS) smoke from conventional and harm reduction cigarettes induced apoptosis in hESC colonies at 1 PE. At 0.1 PE (noncytotoxic), SS smoke from all brands inhibited attachment of hESC colonies to Matrigel with the strongest inhibition occurring in harm reduction brands. At 0.1 PE, SS smoke, but not MS smoke, from all brands inhibited hESC growth, and two harm reduction brands were more potent than the conventional brand. In general, hESC appeared more sensitive to smoke than their mouse ESC counterparts. Although harm reduction cigarettes are often marketed as safer than conventional brands, our assays show that SS smoke from harm reduction cigarettes was at least as potent or in some cases more potent than smoke from a conventional brand and that SS smoke was more inhibitory than MS smoke in all assays.
Methods for Culturing Mouse and Human Embryonic Stem Cells
Mouse embryonic stem cells (mESCs) were first derived and cultured almost 30 years ago and ever since have been valuable tools for creating knockout mice and for studying early mammalian development. More recently (1998), human embryonic stem cells (hESCs) have been derived from blastocysts, and numerous methods have evolved to culture hESCs in vitro in both complex and defined media. hESCs are especially important at this time as they could potentially be used to treat degenerative diseases and to access the toxicity of new drugs and environmental chemicals. For both human and mouse ESCs, fibroblast feeder layers are often used at some phase in the culturing protocol. The feeders - often mouse embryonic fibroblasts (mEFs) - provide a substrate that increases plating efficiency, helps maintain pluripotency, and facilitates survival and growth of the stem cells. Various protocols for culturing embryonic stem cells from both species are available with newer trends moving toward feeder-free and serum-free culture. The purpose of this chapter is to provide basic protocol information on the isolation of mouse embryonic fibroblasts and establishment of feeder layers, the culture of mESCs on both mEFs and on gelatin in serum-containing medium, and the culture of hESCs in defined media on both mEFs (hESC culture medium) and Matrigel (mTeSR). These basic protocols are intended for researchers wanting to develop stem cell research in their labs. These protocols have been tested in our laboratory and work well. They can be modified and adapted for any relevant user's particular purpose.
Mouse and Human Embryonic Stem Cells: Can They Improve Human Health by Preventing Disease?
Given the vast number of chemicals that are released into the environment each year, it is imperative that we develop new predictive models to identify toxicants before unavoidable exposure harms the health of humans and other organisms. In vitro models are especially attractive in predictive toxicology as they can greatly reduce assay costs and animal usage while identifying those chemicals that may require further in vivo evaluation. With the derivation of both mouse and human embryonic stem cells, new opportunities have developed that could revolutionize the field of predictive toxicology. Stem cells themselves can be used to model earliest stages of development, or they can be differentiated to study later aspects of development and thereby model post-implantation. Because embryos and fetuses are usually more sensitive to environmental toxicants than adults, stem cells provide an unique tool for studying the prenatal phase in our life cycle. The embryonic stem cell test (EST), which has been validated for use with mouse ESC (mESC), is an accurate predictor of embryotoxic compounds, particularly those that are highly embryotoxic. Human embryonic stem cells (hESCs), although not yet incorporated into a validated test, are a particularly attractive platform for toxicological testing as they can give us direct information on humans and avoid concerns about species variation in response. This review discusses toxicological studies and strategies that have been used with embryonic stem cells during the past five years and possible directions that could lead to improvements in the development of predictive assays in the future.
