292 research outputs found

    Analysis of diving behavior of Adelie penguins using acceleration data logger

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    Acceleration data loggers were attached to five adult Adelie penguins at Hukuro Cove, Lutzow-Holm Bay in austral summer 1997/1998. The loggers recorded time series data of speed, depth, surging acceleration and swaying acceleration in flush memories inside. From time series analyses, the frequency of 2- to 3-Hz was found in the surging acceleration during descent in a straight line. The cycle seemed to correspond to wingbeat frequency of the Adelie penguin. The relation between wingbeat frequency and diving depth was that the frequency ranged from 1.5-Hz to 3.0-Hz when the penguins dive in water shallower than 30-m and was over 2.5-Hz in water deeper than 50-m. The acceleration data logger is a powerful tool to estimate kinematic parameters of free-range marine animals

    Low-rank constrained multichannel signal denoising considering channel-dependent sensitivity inspired by self-supervised learning for optical fiber sensing

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    Optical fiber sensing is a technology wherein audio, vibrations, and temperature are detected using an optical fiber; especially the audio/vibrations-aware sensing is called distributed acoustic sensing (DAS). In DAS, observed data, which is comprised of multichannel data, has suffered from severe noise levels because of the optical noise or the installation methods. In conventional methods for denoising DAS data, signal-processing- or deep-neural-network (DNN)-based models have been studied. The signal-processing-based methods have the interpretability, i.e., non-black box. The DNN-based methods are good at flexibility designing network architectures and objective functions, that is, priors. However, there is no balance between the interpretability and the flexibility of priors in the DAS studies. The DNN-based methods also require a large amount of training data in general. To address the problems, we propose a DNN-structure signal-processing-based denoising method in this paper. As the priors of DAS, we employ spatial knowledge; low rank and channel-dependent sensitivity using the DNN-based structure. The result of fiber-acoustic sensing shows that the proposed method outperforms the conventional methods and the robustness to the number of the spatial ranks. Moreover, the optimized parameters of the proposed method indicate the relationship with the channel sensitivity; the interpretability.Comment: Accepted for ICASSP202

    Chemical labelling for visualizing native AMPA receptors in live neurons

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    The location and number of neurotransmitter receptors are dynamically regulated at postsynaptic sites. However, currently available methods for visualizing receptor trafficking require the introduction of genetically engineered receptors into neurons, which can disrupt the normal functioning and processing of the original receptor. Here we report a powerful method for visualizing native α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors (AMPARs) which are essential for cognitive functions without any genetic manipulation. This is based on a covalent chemical labelling strategy driven by selective ligand-protein recognition to tether small fluorophores to AMPARs using chemical AMPAR modification (CAM) reagents. The high penetrability of CAM reagents enables visualization of native AMPARs deep in brain tissues without affecting receptor function. Moreover, CAM reagents are used to characterize the diffusion dynamics of endogenous AMPARs in both cultured neurons and hippocampal slices. This method will help clarify the involvement of AMPAR trafficking in various neuropsychiatric and neurodevelopmental disorders

    THE ULTRASONIC TRACKING OF MEKONG GIANT CATFISH PANGASLANODON GIGAS IN MEKONG RIVER

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    Southeast Asia Sea Turtle Associative ResearchBangkok, Thailand, 16-19 December 2002The Mekong giant catfish Pangasianodon gigas is endemic to the Mekong River, measuring up to 3 m in length and weighing in excess of 300 kg. The number of the wild catfish in the Mekong River has decreased due to the development of the Mekong River these days. Therefore, ecological researches are urgently needed to conserve the catfish. However, there was no method to monitor the movement of the catfish continuously in the Mekong River. The objective of this study was to test a feasibility of coded ultrasonic tracking system to monitor the contineous movement of the catfish in such a large river, the Mekong River. We released ten cultured catfish in the Mekong River. The catfish tended to move downstream or stayed around the release point just after the release. Four of ten catfish moved upstream for 60 km in 2-3 days although one fish moved downstream for 40 km. This tracking system that we tested could be a feasible system to monitor the continuous movement of the catfish in such a large river, the Mekong River

    Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital-based Cancer Registry

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    Background: Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type. Methods: From a Hospital-based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow-up periods of less than 1 month. SPSS 25 was used for statistical analysis. Results: The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793-12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782-10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275-9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280-9.231). The 2-year survival rate after hepatic metastasis was 21.7%. Conclusions: The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow-up after treatment.ArticleCancer medicine 17(17) : 6159-6165(2020)journal articl

    Bioorthogonal chemical labeling of endogenous neurotransmitter receptors in living mouse brains

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    生きた動物脳内で発現する神経伝達物質受容体に目印を付ける新手法を開発 --遺伝子操作を伴わず、生体内でたんぱく質の機能解析が可能に--. 京都大学プレスリリース. 2024-02-05.Neurotransmitter receptors are essential components of synapses for communication between neurons in the brain. Because the spatiotemporal expression profiles and dynamics of neurotransmitter receptors involved in many functions are delicately governed in the brain, in vivo research tools with high spatiotemporal resolution for receptors in intact brains are highly desirable. Covalent labeling by chemical reaction (chemical labeling) of proteins without genetic manipulation is now a powerful method for analyzing receptors in vitro. However, selective target receptor labeling in the brain has not yet been achieved. This study shows that ligand-directed alkoxyacylimidazole (LDAI) chemistry can be used to selectively tether synthetic probes to target endogenous receptors in living mouse brains. The reactive LDAI reagents with negative charges were found to diffuse well over the whole brain and could selectively label target endogenous receptors, including AMPAR, NMDAR, mGlu1, and GABAAR. This simple and robust labeling protocol was then used for various applications: three-dimensional spatial mapping of endogenous receptors in the brains of healthy and disease-model mice; multi-color receptor imaging; and pulse–chase analysis of the receptor dynamics in postnatal mouse brains. Here, results demonstrated that bioorthogonal receptor modification in living animal brains may provide innovative molecular tools that contribute to the in-depth understanding of complicated brain functions
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