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Biology subjects

Yadohisa, H.

Publications and source records attributed to Yadohisa, H..

3 recordsLinked to original sources

Trajectory Inference for Multi-Omics Data Using Ordered Labels

Trajectory inference (TI) has emerged as a crucial approach for understanding cellular development and differentiation processes. By reconstructing the temporal ordering of individual cells, TI can analyze the mechanisms underlying development and disease progression. Various TI methods have been proposed and applied across diverse fields, including cancer research and immunology. However, most existing methods rely solely on gene expression data and do not incorporate other omics information such as DNA methylation, chromatin accessibility, and protein expression. To address this limitation, approaches that integrate multiple omics datasets for TI have been proposed. Nevertheless, these methods typically assume the use of only common variables across datasets, making it difficult to align heterogeneous data with differing measurement targets across omics layers. This limitation can lead to information loss and challenges in capturing interactions between different omics datasets, which may reduce integration accuracy. In this study, we propose a novel TI method that captures interactions among variables across different omics layers and accommodates unpaired datasets with non-overlapping measurement targets. By effectively capturing relationships between different omics layers, our approach enables a more comprehensive multi-omics TI framework, thus providing deeper insights into cellular development.

bioinformatics↗

How neural network structure alters the brain's self-organized criticality

The brain criticality hypothesis has been a central research topic in theoretical neuroscience for two decades. This hypothesis suggests that the brain operates near the critical point at the boundary between order and disorder, where it acquires its information-processing capabilities. The mechanism that maintains this critical state has been proposed as a feedback system known as self-organized criticality (SOC); brain parameters, such as synaptic plasticity, are regulated internally without external adjustment. Therefore, clarifying how SOC occurs can help us to understand the mechanisms that maintain brain function and cause brain disorders. From the standpoint of neural network structures, the topology of neural circuits also plays a crucial role in information processing, with healthy neural networks exhibiting small-world, scale-free, and modular characteristics. However, how these network structures affect SOC remains poorly understood. In this study, we numerically investigated the possibility that the structure of neural networks contributes to the brains critical state and dysfunction using a mathematical model. Our results reveal that the time scales at which synaptic plasticity operates to achieve a critical state differ depending on the network structure. Additionally, we observed Dragon king phenomena associated with abnormal neural activity, depending on the network structure and synaptic plasticity time scales. Notably, Dragon king was observed over a wide range of synaptic plasticity time scales in scale-free networks with high-degree hub nodes. This study emphasizes the importance of neural network topology in neuroscience from the perspective of SOC.

neuroscience↗

Short-term effects on brain functional network caused by focused-attention meditation revealed by Tucker3 clustering on graph theoretical metrics

This study examines the short-term effects of focused-attention meditation on functional brain state in novice meditators. There are a number of feature metrics for functional brain states, such as functional connectivity, graph theoretical metrics, and amplitude of low frequency fluctuation (ALFF). It is necessary to choose appropriate metrics and also to specify the region of interests (ROIs) from a number of brain regions. Here, we use a Tucker3 clustering method, which simultaneously selects the feature vectors (graph theoretical metrics and fractional ALFF) and the ROIs that can discriminate between resting and meditative states based on the characteristics of the given data. In this study, breath-counting meditation, one of the most popular forms of focused-attention meditation, was used and brain activities during resting and meditation states were measured by functional magnetic resonance imaging. The results indicated that the clustering coefficients of eight brain regions tended to increase through the meditation. Our results reveal that short-term effects of breath-counting meditation can be explained by network density changes in these eight brain regions.

neuroscience↗