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Echocardiography to Cardiac MRI View Transformation for Real-Time Blind Restoration

Adalioglu, Ilke, Kiranyaz, Serkan, Ahishali, Mete, Degerli, Aysen, Hamid, Tahir, Ghaffar, Rahmat, Hamila, Ridha, Gabbouj, Moncef

arXiv.org Artificial Intelligence

Echocardiography is the most widely used imaging to monitor cardiac functions, serving as the first line in early detection of myocardial ischemia and infarction. However, echocardiography often suffers from several artifacts including sensor noise, lack of contrast, severe saturation, and missing myocardial segments which severely limit its usage in clinical diagnosis. In recent years, several machine learning methods have been proposed to improve echocardiography views. Yet, these methods usually address only a specific problem (e.g. denoising) and thus cannot provide a robust and reliable restoration in general. On the other hand, cardiac MRI provides a clean view of the heart without suffering such severe issues. However, due to its significantly higher cost, it is often only afforded by a few major hospitals, hence hindering its use and accessibility. In this pilot study, we propose a novel approach to transform echocardiography into the cardiac MRI view. For this purpose, Echo2MRI dataset, consisting of echocardiography and real cardiac MRI image pairs, is composed and will be shared publicly. A dedicated Cycle-consistent Generative Adversarial Network (Cycle-GAN) is trained to learn the transformation from echocardiography frames to cardiac MRI views. An extensive set of qualitative evaluations shows that the proposed transformer can synthesize high-quality artifact-free synthetic cardiac MRI views from a given sequence of echocardiography frames. Medical evaluations performed by a group of cardiologists further demonstrate that synthetic MRI views are indistinguishable from their original counterparts and are preferred over their initial sequence of echocardiography frames for diagnosis in 78.9% of the cases.


BOrg: A Brain Organoid-Based Mitosis Dataset for Automatic Analysis of Brain Diseases

Awais, Muhammad, Hameed, Mehaboobathunnisa Sahul, Bhattacharya, Bidisha, Reiner, Orly, Anwer, Rao Muhammad

arXiv.org Artificial Intelligence

Recent advances have enabled the study of human brain development using brain organoids derived from stem cells. Quantifying cellular processes like mitosis in these organoids offers insights into neurodevelopmental disorders, but the manual analysis is time-consuming, and existing datasets lack specific details for brain organoid studies. We introduce BOrg, a dataset designed to study mitotic events in the embryonic development of the brain using confocal microscopy images of brain organoids. BOrg utilizes an efficient annotation pipeline with sparse point annotations and techniques that minimize expert effort, overcoming limitations of standard deep learning approaches on sparse data. We adapt and benchmark state-of-the-art object detection and cell counting models on BOrg for detecting and analyzing mitotic cells across prophase, metaphase, anaphase, and telophase stages. Our results demonstrate these adapted models significantly improve mitosis analysis efficiency and accuracy for brain organoid research compared to existing methods. BOrg facilitates the development of automated tools to quantify statistics like mitosis rates, aiding mechanistic studies of neurodevelopmental processes and disorders. Data and code are available at https://github.com/awaisrauf/borg.


Structural Balance and Random Walks on Complex Networks with Complex Weights

Tian, Yu, Lambiotte, Renaud

arXiv.org Artificial Intelligence

Complex numbers define the relationship between entities in many situations. A canonical example would be the off-diagonal terms in a Hamiltonian matrix in quantum physics. Recent years have seen an increasing interest to extend the tools of network science when the weight of edges are complex numbers. Here, we focus on the case when the weight matrix is Hermitian, a reasonable assumption in many applications, and investigate both structural and dynamical properties of the complex-weighted networks. Building on concepts from signed graphs, we introduce a classification of complex-weighted networks based on the notion of structural balance, and illustrate the shared spectral properties within each type. We then apply the results to characterise the dynamics of random walks on complex-weighted networks, where local consensus can be achieved asymptotically when the graph is structurally balanced, while global consensus will be obtained when it is strictly unbalanced. Finally, we explore potential applications of our findings by generalising the notion of cut, and propose an associated spectral clustering algorithm. We also provide further characteristics of the magnetic Laplacian, associating directed networks to complex-weighted ones. The performance of the algorithm is verified on both synthetic and real networks.


Fusion of complementary 2D and 3D mesostructural datasets using generative adversarial networks

Dahari, Amir, Kench, Steve, Squires, Isaac, Cooper, Samuel J.

arXiv.org Artificial Intelligence

Modelling the impact of a material's mesostructure on device level performance typically requires access to 3D image data containing all the relevant information to define the geometry of the simulation domain. This image data must include sufficient contrast between phases to distinguish each material, be of high enough resolution to capture the key details, but also have a large enough field-of-view to be representative of the material in general. It is rarely possible to obtain data with all of these properties from a single imaging technique. In this paper, we present a method for combining information from pairs of distinct but complementary imaging techniques in order to accurately reconstruct the desired multi-phase, high resolution, representative, 3D images. Specifically, we use deep convolutional generative adversarial networks to implement super-resolution, style transfer and dimensionality expansion. To demonstrate the widespread applicability of this tool, two pairs of datasets are used to validate the quality of the volumes generated by fusing the information from paired imaging techniques. Three key mesostructural metrics are calculated in each case to show the accuracy of this method. Having confidence in the accuracy of our method, we then demonstrate its power by applying to a real data pair from a lithium ion battery electrode, where the required 3D high resolution image data is not available anywhere in the literature. We believe this approach is superior to previously reported statistical material reconstruction methods both in terms of its fidelity and ease of use. Furthermore, much of the data required to train this algorithm already exists in the literature, waiting to be combined. As such, our open-access code could precipitate a step change by generating the hard to obtain high quality image volumes necessary to simulate behaviour at the mesoscale.


Working of Neural Networks

#artificialintelligence

In my previous blog I discussed a type of network with Human Brain Analogy, how it functions and how it is similar to the Human Brain and also covered various features of Neural Networks- Weights, Sum and Non-Linearity and ended it by classifying some important types of networks. Now lets know the complete working of a Neural Network. These are the main root behind the working of a neural network. Now, lets see all one by one. As you all know, there are some particular inputs on left side which passes through some nodes in the network and gets on the output side, so this movement of information from left side towards the output on right side is called Forward Propagation.


Significant changes in EEG neural oscillations during different phases of three-dimensional multiple object tracking task (3D-MOT) imply different roles for attention and working memory

Roy, Yannick, Faubert, Jocelyn

arXiv.org Artificial Intelligence

Our ability to track multiple objects in a dynamic environment enables us to perform everyday tasks such as driving, playing team sports, and walking in a crowded mall. Despite more than three decades of literature on multiple object tracking (MOT) tasks, the underlying and intertwined neural mechanisms remain poorly understood. Here we looked at the electroencephalography (EEG) neural correlates and their changes across the three phases of a 3D-MOT task, namely identification, tracking and recall. We recorded the EEG activity of 24 participants while they were performing a 3D-MOT task with either 1, 2 or 3 targets where some trials were lateralized and some were not. We observed what seems to be a handoff between focused attention and working memory processes when going from tracking to recall. Our findings revealed a strong inhibition in delta and theta frequencies from the frontal region during tracking, followed by a strong (re)activation of these same frequencies during recall. Our results also showed contralateral delay activity (CDA) for the lateralized trials, in both the identification and recall phases but not during tracking.


NSF Funds Machine-Learning Research at UNO and UNL to Study Energy Requirements of Walking in Older Adults

#artificialintelligence

However, as we grow older, our bodies become less energy efficient, turning simple daily activities like walking around a block into a daunting effort. Although the effect of aging on the energetic costs of walking is well-documented, we do not yet have a complete understanding of what causes the progressive increase in energetic cost. One of the challenges to understanding this phenomenon is that current technologies for assessing metabolic energy consumption require measuring several minutes of breathing. These measurements are too slow to gain insight into the energetic cost of different phases of the gait cycle. The Disability and Rehabilitation Engineering program (DARE) and the Established Program to Stimulate Competitive Research (EPSCoR) from the National Science Foundation (NSF) are funding a collaborative project at the University of Nebraska at Omaha (UNO) and at the University of Nebraska at Lincoln (UNL) aimed at investigating the metabolic cost of different phases of the walking gait cycle. It is expected that this inter-campus collaboration between researchers from different disciplines will enable the development more creative solutions than single-discipline research.


Men and women's brains really do work differently

Daily Mail - Science & tech

It's often said that men and women's brains work so differently that one sex is from Venus and the other is from Mars. Well now a new study supports this hypothesis after finding 1,000 genes that are much more active in one gender than the other. It looked into how male and female mouse brains differ by probing areas that are known to program'rating, dating, mating and hating' behaviours. The behaviours -- for example, male mice's quick determination of a stranger's sex, females' receptivity to mating, and maternal protectiveness -- help the animals reproduce and their offspring survive. These differences are also likely reflected in the brains of men and women, the researchers from Stanford Medicine said.