1,298 research outputs found
One new cucurbitane triterpenoid from the fruits of Momordica charantia
One new cucurbitane triterpenoid commonly named neokuguaglucoside, together with three known compounds momordicoside M, momordicoside N, and momordicoside A were isolated from the fresh fruits of Momordica charantia. The new one's structure with an interesting sugar-like groups attached to the side chain was elucidated by spectroscopic analysis and semiepirical (AM1) quantum chemical method
Mechanisms Of Intrinsic Epileptogenesis In Human Gelastic Seizures With Hypothalamic Hamartoma
Human hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are refractory to medical therapy. Ictal EEG recordings from the HH have demonstrated that the epileptic source of gelastic seizures lies within the HH lesion itself. Recent advances in surgical techniques targeting HH have led to dramatic improvements in seizure control, which further supports the hypothesis that gelastic seizures originate within the HH. However, the basic cellular and molecular mechanisms of epileptogenesis in this subcortical lesion are poorly understood. Since 2003, Barrow Neurological Institute has maintained a multidisciplinary clinical program to evaluate and treat patients with HH. This program has provided a unique opportunity to investigate the basic mechanisms of epileptogenesis using surgically resected HH tissue. The first report on the electrophysiological properties of HH neurons was published in 2005. Since then, ongoing research has provided additional insights into the mechanisms by which HH generate seizure activity. In this review, we summarize this progress and propose a cellular model that suggests that GABA-mediated excitation contributes to epileptogenesis in HH lesions
Gated Attention Coding for Training High-performance and Efficient Spiking Neural Networks
Spiking neural networks (SNNs) are emerging as an energy-efficient
alternative to traditional artificial neural networks (ANNs) due to their
unique spike-based event-driven nature. Coding is crucial in SNNs as it
converts external input stimuli into spatio-temporal feature sequences.
However, most existing deep SNNs rely on direct coding that generates powerless
spike representation and lacks the temporal dynamics inherent in human vision.
Hence, we introduce Gated Attention Coding (GAC), a plug-and-play module that
leverages the multi-dimensional gated attention unit to efficiently encode
inputs into powerful representations before feeding them into the SNN
architecture. GAC functions as a preprocessing layer that does not disrupt the
spike-driven nature of the SNN, making it amenable to efficient neuromorphic
hardware implementation with minimal modifications. Through an observer model
theoretical analysis, we demonstrate GAC's attention mechanism improves
temporal dynamics and coding efficiency. Experiments on CIFAR10/100 and
ImageNet datasets demonstrate that GAC achieves state-of-the-art accuracy with
remarkable efficiency. Notably, we improve top-1 accuracy by 3.10\% on CIFAR100
with only 6-time steps and 1.07\% on ImageNet while reducing energy usage to
66.9\% of the previous works. To our best knowledge, it is the first time to
explore the attention-based dynamic coding scheme in deep SNNs, with
exceptional effectiveness and efficiency on large-scale datasets.Comment: 12 pages, 7 figure
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