514 research outputs found
Automated recognition of cell phenotypes in histology images based on membrane- and nuclei-targeting biomarkers
<p>Abstract</p> <p>Background</p> <p>Three-dimensional <it>in vitro </it>culture of cancer cells are used to predict the effects of prospective anti-cancer drugs <it>in vivo</it>. In this study, we present an automated image analysis protocol for detailed morphological protein marker profiling of tumoroid cross section images.</p> <p>Methods</p> <p>Histologic cross sections of breast tumoroids developed in co-culture suspensions of breast cancer cell lines, stained for E-cadherin and progesterone receptor, were digitized and pixels in these images were classified into five categories using <it>k</it>-means clustering. Automated segmentation was used to identify image regions composed of cells expressing a given biomarker. Synthesized images were created to check the accuracy of the image processing system.</p> <p>Results</p> <p>Accuracy of automated segmentation was over 95% in identifying regions of interest in synthesized images. Image analysis of adjacent histology slides stained, respectively, for Ecad and PR, accurately predicted regions of different cell phenotypes. Image analysis of tumoroid cross sections from different tumoroids obtained under the same co-culture conditions indicated the variation of cellular composition from one tumoroid to another. Variations in the compositions of cross sections obtained from the same tumoroid were established by parallel analysis of Ecad and PR-stained cross section images.</p> <p>Conclusion</p> <p>Proposed image analysis methods offer standardized high throughput profiling of molecular anatomy of tumoroids based on both membrane and nuclei markers that is suitable to rapid large scale investigations of anti-cancer compounds for drug development.</p
Understanding Large-Language Model (LLM)-powered Human-Robot Interaction
Large-language models (LLMs) hold significant promise in improving
human-robot interaction, offering advanced conversational skills and
versatility in managing diverse, open-ended user requests in various tasks and
domains. Despite the potential to transform human-robot interaction, very
little is known about the distinctive design requirements for utilizing LLMs in
robots, which may differ from text and voice interaction and vary by task and
context. To better understand these requirements, we conducted a user study (n
= 32) comparing an LLM-powered social robot against text- and voice-based
agents, analyzing task-based requirements in conversational tasks, including
choose, generate, execute, and negotiate. Our findings show that LLM-powered
robots elevate expectations for sophisticated non-verbal cues and excel in
connection-building and deliberation, but fall short in logical communication
and may induce anxiety. We provide design implications both for robots
integrating LLMs and for fine-tuning LLMs for use with robots.Comment: 10 pages, 4 figures. Callie Y. Kim and Christine P. Lee contributed
equally to the work. To be published in Proceedings of the 2024 ACM/IEEE
International Conference on Human-Robot Interaction (HRI '24), March 11--14,
2024, Boulder, CO, US
Gravitational Collapse of Inhomogeneous Dust in (2+1) Dimensions
We examine the gravitational collapse of spherically symmetric inhomogeneous
dust in (2+1) dimensions, with cosmological constant. We obtain the analytical
expressions for the interior metric. We match the solution to a vacuum
exterior. We discuss the nature of the singularity formed by analyzing the
outgoing radial null geodesics. We examine the formation of trapped surfaces
during the collapse.Comment: Accepted for publication in CQ
Journey to the Center of the Cookie Ecosystem: Unraveling Actors' Roles and Relationships
Web pages have been steadily increasing in complexity over time, including code snippets from several distinct origins and organizations. While this may be a known phenomenon, its implications on the panorama of cookie tracking received little attention until now. Our study focuses on filling this gap, through the analysis of crawl results that are both large-scale and fine-grained, encompassing the whole set of events that lead to the creation and sharing of around 138 million cookies from crawling more than 6 million webpages. Our analysis lets us paint a highly detailed picture of the cookie ecosystem, discovering an intricate network of connections between players that reciprocally exchange information and include each other's content in web pages whose owners may not even be aware. We discover that, in most webpages, tracking cookies are set and shared by organizations at the end of complex chains that involve several middlemen. We also study the impact of cookie ghostwriting, i.e., a common practice where an entity creates cookies in the name of another party, or the webpage. We attribute and define a set of roles in the cookie ecosystem, related to cookie creation and sharing. We see that organizations can and do follow different patterns, including behaviors that previous studies could not uncover: for example, many cookie ghostwriters send cookies they create to themselves, which makes them able to perform cross-site tracking even for users that deleted third-party cookies in their browsers. While some organizations concentrate the flow of information on themselves, others behave as dispatchers, allowing other organizations to perform tracking on the pages that include their content
A CASE STUDY: MATERIAL FLOW SIMULATION BASED ANALYSIS FOR MAINTENANCE NETWORK IMPROVEMENT
The competitiveness of enterprises operating in complex environments depends on how well their value creation factors can adapt to disruptions caused by unanticipated events. Building this resilience requires the ability to identify uncertainties and to model their impact on operations, which is difficult to achieve. Thus, increasing adaptability in maintenance and repair networks calls for an adequate approach to address uncertainties. It is necessary to consider the maintenance activities within and outside the company as well as those affecting all equipment supplier partners. Enhancement in simulation technique has opened the opportunity to analyse this complex system. This paper presents a comprehensive analysis introducing a potential approach using material flow simulation that models and simulates the impact of existing maintenance and repair activities to identify the uncertainties to increase the flexibility of the network while ensuring profitability and continuity
The collision and snapping of cosmic strings generating spherical impulsive gravitational waves
The Penrose method for constructing spherical impulsive gravitational waves
is investigated in detail, including alternative spatial sections and an
arbitrary cosmological constant. The resulting waves include those that are
generated by a snapping cosmic string. The method is used to construct an
explicit exact solution of Einstein's equations describing the collision of two
nonaligned cosmic strings in a Minkowski background which snap at their point
of collision.Comment: 10 pages, 6 figures, To appear in Class. Quantum Gra
Analytical Solution of a Stochastic Content Based Network Model
We define and completely solve a content-based directed network whose nodes
consist of random words and an adjacency rule involving perfect or approximate
matches, for an alphabet with an arbitrary number of letters. The analytic
expression for the out-degree distribution shows a crossover from a leading
power law behavior to a log-periodic regime bounded by a different power law
decay. The leading exponents in the two regions have a weak dependence on the
mean word length, and an even weaker dependence on the alphabet size. The
in-degree distribution, on the other hand, is much narrower and does not show
scaling behavior. The results might be of interest for understanding the
emergence of genomic interaction networks, which rely, to a large extent, on
mechanisms based on sequence matching, and exhibit similar global features to
those found here.Comment: 13 pages, 5 figures. Rewrote conclusions regarding the relevance to
gene regulation networks, fixed minor errors and replaced fig. 4. Main body
of paper (model and calculations) remains unchanged. Submitted for
publicatio
Can a Unruh Detector Feel a Cosmic String?
Unruh's detector calculation is used to study the effect of the defect angle
in a space-time with a cosmic string for both the excitation and
deexcitation cases. It is found that a rotating detector results in a non-zero
effect for both finite (small) and infinite (large) time
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