515 research outputs found
Mouse neuroblastoma cell-based model and the effect of epileptic events on calcium oscillations and neural spikes
Recently, mouse neuroblastoma cells have been considered as an attractive model for the study of human neurological and prion diseases, and they have been intensively used as a model system in different areas. For example, the differentiation of neuro2a (N2A) cells, receptor-mediated ion current, and glutamate-induced physiological responses have been actively investigated with these cells. These mouse neuroblastoma N2A cells are of interest because they grow faster than other cells of neural origin and have a number of other advantages. The calcium oscillations and neural spikes of mouse neuroblastoma N2A cells in epileptic conditions are evaluated. Based on our observations of neural spikes in these cells with our proposed imaging modality, we reported that they can be an important model in epileptic activity studies. We concluded that mouse neuroblastoma N2A cells produce epileptic spikes in vitro in the same way as those produced by neurons or astrocytes. This evidence suggests that increased levels of neurotransmitter release due to the enhancement of free calcium from 4-aminopyridine causes the mouse neuroblastoma N2A cells to produce epileptic spikes and calcium oscillations.open0
Performance of a Distributed Simultaneous Strain and Temperature Sensor Based on a Fabry-Perot Laser Diode and a Dual-Stage FBG Optical Demultiplexer
A simultaneous strain and temperature measurement method using a Fabry-Perot laser diode (FP-LD) and a dual-stage fiber Bragg grating (FBG) optical demultiplexer was applied to a distributed sensor system based on Brillouin optical time domain reflectometry (BOTDR). By using a Kalman filter, we improved the performance of the FP-LD based OTDR, and decreased the noise using the dual-stage FBG optical demultiplexer. Applying the two developed components to the BOTDR system and using a temperature compensating algorithm, we successfully demonstrated the simultaneous measurement of strain and temperature distributions under various experimental conditions. The observed errors in the temperature and strain measured using the developed sensing system were 0.6 °C and 50 με, and the spatial resolution was 1 m, respectively
Occluded Person Re-Identification via Relational Adaptive Feature Correction Learning
Occluded person re-identification (Re-ID) in images captured by multiple
cameras is challenging because the target person is occluded by pedestrians or
objects, especially in crowded scenes. In addition to the processes performed
during holistic person Re-ID, occluded person Re-ID involves the removal of
obstacles and the detection of partially visible body parts. Most existing
methods utilize the off-the-shelf pose or parsing networks as pseudo labels,
which are prone to error. To address these issues, we propose a novel Occlusion
Correction Network (OCNet) that corrects features through relational-weight
learning and obtains diverse and representative features without using external
networks. In addition, we present a simple concept of a center feature in order
to provide an intuitive solution to pedestrian occlusion scenarios.
Furthermore, we suggest the idea of Separation Loss (SL) for focusing on
different parts between global features and part features. We conduct extensive
experiments on five challenging benchmark datasets for occluded and holistic
Re-ID tasks to demonstrate that our method achieves superior performance to
state-of-the-art methods especially on occluded scene.Comment: ICASSP 202
Extending density functional theory with near chemical accuracy beyond pure water
Density functional simulations of condensed phase water are typically inaccurate, due to the inaccuracies of approximate functionals. A recent breakthrough showed that the SCAN approximation can yield chemical accuracy for pure water in all its phases, but only when its density is corrected. This is a crucial step toward first-principles biosimulations. However, weak dispersion forces are ubiquitous and play a key role in noncovalent interactions among biomolecules, but are not included in the new approach. Moreover, naïve inclusion of dispersion in HF-SCAN ruins its high accuracy for pure water. Here we show that systematic application of the principles of density-corrected DFT yields a functional (HF-r2SCAN-DC4) which recovers and not only improves over HF-SCAN for pure water, but also captures vital noncovalent interactions in biomolecules, making it suitable for simulations of solutions
A 1.35GHz All-Digital Fractional-N PLL with Adaptive Loop Gain Controller and Fractional Divider
A 1.35GHz all-digital phase-locked loop (ADPLL)
with an adaptively controlled loop filter and a 1/3rd-resolution
fractional divider is presented. The adaptive loop gain controller
(ALGC) effectively reduces the nonlinear characteristics of the
bang-bang phase-frequency detector (BBPFD). The fractional
divider partially compensates for the input phase error which is
caused by the fractional-N frequency synthesis operation. A
prototype ADPLL using a BBPFD with a dead zone free retimer,
an ALGC, and a fractional divider is fabricated in 0.13m
CMOS. The core occupies 0.19mm2 and consumes 13.7mW from
a 1.2V supply. The measured RMS jitter was 4.17ps at a
1.35GHz clock output
Synchronizing Vision and Language: Bidirectional Token-Masking AutoEncoder for Referring Image Segmentation
Referring Image Segmentation (RIS) aims to segment target objects expressed
in natural language within a scene at the pixel level. Various recent RIS
models have achieved state-of-the-art performance by generating contextual
tokens to model multimodal features from pretrained encoders and effectively
fusing them using transformer-based cross-modal attention. While these methods
match language features with image features to effectively identify likely
target objects, they often struggle to correctly understand contextual
information in complex and ambiguous sentences and scenes. To address this
issue, we propose a novel bidirectional token-masking autoencoder (BTMAE)
inspired by the masked autoencoder (MAE). The proposed model learns the context
of image-to-language and language-to-image by reconstructing missing features
in both image and language features at the token level. In other words, this
approach involves mutually complementing across the features of images and
language, with a focus on enabling the network to understand interconnected
deep contextual information between the two modalities. This learning method
enhances the robustness of RIS performance in complex sentences and scenes. Our
BTMAE achieves state-of-the-art performance on three popular datasets, and we
demonstrate the effectiveness of the proposed method through various ablation
studies
Pixel-Level Equalized Matching for Video Object Segmentation
Feature similarity matching, which transfers the information of the reference
frame to the query frame, is a key component in semi-supervised video object
segmentation. If surjective matching is adopted, background distractors can
easily occur and degrade the performance. Bijective matching mechanisms try to
prevent this by restricting the amount of information being transferred to the
query frame, but have two limitations: 1) surjective matching cannot be fully
leveraged as it is transformed to bijective matching at test time; and 2)
test-time manual tuning is required for searching the optimal hyper-parameters.
To overcome these limitations while ensuring reliable information transfer, we
introduce an equalized matching mechanism. To prevent the reference frame
information from being overly referenced, the potential contribution to the
query frame is equalized by simply applying a softmax operation along with the
query. On public benchmark datasets, our proposed approach achieves a
comparable performance to state-of-the-art methods
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