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Three-dimensional markerless motion capture of multiple freely behaving monkeys toward automated characterization of social behavior
Full text linkGiven their high sociality and close evolutionary distance to humans, monkeys are an essential animal model for unraveling the biological mechanisms underlying human social behavior and elucidating the pathogenesis of diseases exhibiting abnormal social behavior. However, behavioral analysis of naturally behaving monkeys requires manual counting of various behaviors, which has been a bottleneck due to problems in throughput and objectivity. Here, we developed a three-dimensional markerless motion capture system that used multi-view data for robust tracking of individual monkeys and accurate reconstruction of the three-dimensional poses of multiple monkeys living in groups. Validation analysis in two monkey groups revealed that the system enabled the characterization of individual social dispositions and relationships through automated detection of eight basic social events. Analyses of social looking demonstrated its potential for investigating adaptive behaviors in a social group. These results suggest that this motion capture system will greatly enhance our ability to analyze primate social behavior.journal articl
Dynamical Network Biomarker Analysis of Biomolecular PID Control Systems Exhibiting Saddle-Node Bifurcation
Full text linkDiabetes progression is increasingly hypothesized to involve the breakdown of homeostasis—a biological feedback regulation—which may be associated with a bifurcation phenomenon. The dynamical network biomarker (DNB) theory aims to detect qualitative state transitions associated with bifurcation phenomena by identifying DNB nodes whose fluctuations increase near critical points. However, identifying DNB nodes is challenging under high-dimensional and low-samplesize conditions. In this study, we focused on a biomolecular PID feedback control system—referred to as aPID—that exhibits saddle-node bifurcation, assuming that it underlies homeostatic regulation. We analytically show that the aPID controller state inherently satisfies DNB conditions at the bifurcation onset, enabling the a priori identification of DNB nodes without the need for exhaustive data-driven analysis.journal articl
Uncertainty-aware Motion Planning based on Stochastic Forward/Inverse Kinematics Models for Tensegrity Manipulators
Full text linkRobots whose shape and stiffness are determined by internal forces generally have complex shape-stiffness relationships that depend on their structure. As a result, there are difficulties such as a decrease in shape reproducibility when the robot is not stiff, and a decrease in the range of motion when the robot is stiff. In this study, we propose a motion planning method that balances shape and stiffness by learning forward and inverse kinematics using a stochastic neural network (NN) and using the uncertainty that can be evaluated by the NN. Through experiments using a tensegrity manipulator with 40 actuators and 20 degrees of freedom in bending posture, we verify the validity of the proposed method.journal articl
Partial gathering of mobile agents in dynamic tori
Full text linkIn this paper, we consider the partial gathering problem of mobile agents in dynamic tori. This problem requires k agents distributed in the network to reach a configuration such that either at least g agents or no agent exists at each node. Thus far, in dynamic graphs, partial gathering is considered in 1-interval connected rings, where one of the links in the ring may be missing at each time step. In this paper, we consider another dynamic topology. Concretely, we consider partial gathering in n×n dynamic tori such that each of the row and column rings is represented as a 1-interval connected ring. In such networks, when k=O(gn), focusing on the relationship between the values of k,n, and g, we characterize the solvability of the problem and analyze the move complexity. First, we show that agents cannot solve the problem when k=o(gn). Second, we show that agents can achieve partial gathering with a total number of O(gn3) moves when 2gn+2n−1≤k≤2gn+6n+16g−12. Finally, we show that agents can achieve partial gathering with a total number of θ(gn2) moves when k≥2gn+6n+16g−11.journal articl
Centrifuge Model Tests on Overtopping Resistance of Levees Reinforced with High-Water Content Excavated Soil and Geotextiles
Full text link本研究では，河道掘削により発生する高含水比状態にある低品質土とジオテキスタイル補強材を組み合わせ，川表法面を補強することで越水時の堤防侵食を抑制する工法の有効性を検討した．遠心模型実験により，補強材の有無および掘削土の含水比が堤防の耐越水性能に与える影響を評価した結果，掘削土と補強材を併用することで越水に対する「粘り強さ」が発揮され，特に高含水比条件で河川水位の保持時間が長くなった．さらに，斜面安定解析によって補強材の補強効果が力学的に裏付けられた．In this study, the effectiveness of a method for mitigating levee erosion during flood overtopping by reinforcing riverside slope surfaces with a combination of low-quality soil with high water content generated by river channel excavation and geotextile reinforcement materials was investigated. Centrifugal model tests were conducted to evaluate the effects of the reinforcement material and the water content of the excavated soil on the flood resistance of the levee. The results showed that the combination of excavated soil and reinforcement material increased resilience against flooding, and the river water level was maintained for a longer period, especially under high water content conditions. Furthermore, the reinforcement effect of the reinforcement material was mechanically verified by slope stability analysis.journal articl
Icing following skeletal muscle injury alters fibro/adipogenic progenitor responses and results in excessive collagen deposition in male rats
Full text linkIcing is a common acute intervention following skeletal muscle injuries in sports medicine; however, previous studies in rodent models indicated that icing impairs muscle regeneration and promotes collagen deposition in regenerating muscles. As fibrosis decreases muscle function and increases the risk of reinjury, it poses a significant challenge for athletes. To address the fibrosis-related impairment of muscle function, we examined the mechanisms underlying icing-induced fibrosis. Specifically, we focused on the response of fibro/adipogenic progenitors (FAPs), key players in muscle fibrosis, during muscle regeneration. Using a crush-injury model in male rats, we investigated the effects of icing on the FAP response and fibrosis-related outcomes. Icing inhibited the early-phase increase in FAPs within injured muscles. Moreover, icing upregulated the expression of transforming growth factor-β1 (TGF-β1), which promotes the differentiation of FAPs into myofibroblasts, particularly 4 and 5 days postinjury, when FAP accumulation was abundant. Consequently, an increased number of α-smooth muscle actin (α-SMA)-positive myofibroblasts and an expanded collagen fiber area were observed during the later stages of icing-treated muscle regeneration, indicating excessive muscle fibrosis. Taken together, our results suggest that icing after muscle injury may promote fibrosis by altering FAP behavior and its surrounding environment, which warrants careful reevaluation of its clinical effectiveness.
NEW & NOTEWORTHY Previous studies have examined the effects of icing on macrophages and muscle stem cells during muscle regeneration. Here, we identified FAPs as another cell population affected by icing and involved in excessive fibrosis. Icing delayed FAP proliferation and increased their number when TGF-β1 was markedly elevated, resulting in excessive collagen deposition. These results reveal how icing contributes to muscle fibrosis by affecting FAP behavior and highlight the importance of FAP dynamics in muscle injury management.journal articl
Human Pose Estimatin From Egocentric Videos
Full text linkAccording to a survey conducted by the Ministry of Health, Labour and Welfare in 2019, about 30% of patients suffer from back pain and stiff shoulders. Although researches on pose estimation have been conducted for a long time, they cannot be used for daily pose estimation, because they need fixed cameras to capture target/subject motion. To solve this problem, the present paper, proposes a novel pose estimation method from egocentric videos using Epipolar Geometry. It computes three rotational angles, i.e., pitch, yaw and roll, from the egocentric motion videos to evaluate differences from his/her normal motion. In the experiment, three egocentric videos were used to verify the performance and effectiveness of the proposed method and reasonable/satisfactory results were obtained.conference pape
A hippocampal CA3 network model considering the contribution of multiple types of ion channels to frequency boost induced by carbachol
Full text linkラット海馬CA3スライスでは，抑制性シナプス伝達の阻害によっててんかん様の神経活動を発生するが，アセチルコリン作動薬であるカルバコールのかん流によってθ周波数帯，もしくはβ周波数帯の振動へと切り替わる．本研究では，この現象のメカニズムをイオンチャネルレベルで説明するため，カルバコールの作用を考慮した海馬CA3神経回路モデルを構築した．結果は，反回性シナプスの抑制とcalcium-activated non-selective cationic チャネルの活性化、およびAHPチャネルの抑制が振動周波数の上昇に寄与することを示唆した．In slice preparations of the rat hippocampal CA3 region, blockade of inhibitory synaptic transmission causes epileptiform oscillations in electric field potentials. However, perfusion with carbachol induces a transition to the theta or beta frequency band (carbachol-induced beta oscillations). To describe the mechanism of carbachol-induced beta oscillations at the ion channel level, we constructed a neural network model of the hippocampal CA3 that accounts for the effects of carbachol. The results suggest that suppression of excitatory synaptic connections, activation of calcium-activated non-selective cationic channels, and inhibition of AHP channels contribute to increased oscillation frequency.journal articl
A Practical Study Utilizing Longitudinal Data over Five Years in University Ice Hockey Teams: Exploring Team Concepts and Key Performance Indicators (KPIs)
Full text linkThis study reports on a practical research project that focused on practice data collected over five years from a university ice hockey team, where the author served as a coach. The paper begins with a brief overview of 'practical research,' followed by a summary of the five years of practice and an examination of the coaching practices evaluated through the accumulated data.departmental bulletin pape
