674 research outputs found
Berberine Improves Glucose Homeostasis in Streptozotocin-Induced Diabetic Rats in Association with Multiple Factors of Insulin Resistance
The present study was carried out to determine the effect of berberine on glucose homeostasis and several biomarkers associated with insulin sensitivity in male Wistar rats with intraperitoneal injection of streptozotocin (STZ)-induced diabetes. Rats with fasting blood glucose 16.7 mmol/L after 2 weeks of STZ injection were divided into two groups. One group was used as the diabetic control and another treated by gavage feeding with 100 mg/kg/d of berberine in water containing 0.5% carboxymethyl cellulose. A group of rats without receiving STZ was used as the normal control. After 7 weeks, berberine supplementation moderately but significantly lowered fasting blood glucose levels and improved oral glucose tolerance. Berberine lowered plasma free fatty acids and C-reactive protein levels without affecting plasma insulin levels. Diabetic rats treated with berberine showed significantly lower plasma triacylglycerol and cholesterol levels. Furthermore, berberine inhibited dipeptidyl peptidase-4 and protein tyrosine phosphatase-1B activities. In conclusion, berberine showed a dramatic effect of lowering blood cholesterol and triacylglycerols and improved moderately glucose homeostasis in STZ-induced diabetic rats in association with multiple factors related to insulin resistance
Liuwei Dihuang Lowers Body Weight and Improves Insulin and Leptin Sensitivity in Obese Rats
The present study was aimed at investigating the efficacy and mechanism(s) of action of a Chinese herbal formulation, Liuwei Dihuang (LWDH), as a prospective natural weight-lowering product. Following a 2-week acclimation period, 48 obesity-prone (OP-CD) rats were divided into 4 groups (n = 12 each). One group served as a positive control for obesity (OP), while the other 3 were challenged twice daily by oral gavage with total daily dosages of 500, 1500, or 3500 mg/kg BW LWDH, respectively, for 10 weeks. One group (n = 12) of obesity-resistant (OR-CD) rats served as the normal control group. All rats were fed the same AIN-93G diet modified to contain 60% energy from fat. The highest LWDH dose significantly reduced body weight during the last 4 weeks of treatment. Food intake was reduced beginning in week 2. The high LWDH dose lowered serum triglyceride (TG) and nonesterified fatty acid (NEFA) levels and body fat. Both the high and medium doses also lowered serum leptin and insulin levels. Liver function testing revealed no adverse side effects under the current experimental conditions. The results of the present study suggest that LWDH has potential as a preventive or therapeutic natural product against overweight and obesity
Key Frame Mechanism For Efficient Conformer Based End-to-end Speech Recognition
Recently, Conformer as a backbone network for end-to-end automatic speech
recognition achieved state-of-the-art performance. The Conformer block
leverages a self-attention mechanism to capture global information, along with
a convolutional neural network to capture local information, resulting in
improved performance. However, the Conformer-based model encounters an issue
with the self-attention mechanism, as computational complexity grows
quadratically with the length of the input sequence. Inspired by previous
Connectionist Temporal Classification (CTC) guided blank skipping during
decoding, we introduce intermediate CTC outputs as guidance into the
downsampling procedure of the Conformer encoder. We define the frame with
non-blank output as key frame. Specifically, we introduce the key frame-based
self-attention (KFSA) mechanism, a novel method to reduce the computation of
the self-attention mechanism using key frames. The structure of our proposed
approach comprises two encoders. Following the initial encoder, we introduce an
intermediate CTC loss function to compute the label frame, enabling us to
extract the key frames and blank frames for KFSA. Furthermore, we introduce the
key frame-based downsampling (KFDS) mechanism to operate on high-dimensional
acoustic features directly and drop the frames corresponding to blank labels,
which results in new acoustic feature sequences as input to the second encoder.
By using the proposed method, which achieves comparable or higher performance
than vanilla Conformer and other similar work such as Efficient Conformer.
Meantime, our proposed method can discard more than 60\% useless frames during
model training and inference, which will accelerate the inference speed
significantly. This work code is available in
{https://github.com/scufan1990/Key-Frame-Mechanism-For-Efficient-Conformer}Comment: This manuscript has been accepted by IEEE Signal Processing Letters
for publicatio
Skipformer: A Skip-and-Recover Strategy for Efficient Speech Recognition
Conformer-based attention models have become the de facto backbone model for
Automatic Speech Recognition tasks. A blank symbol is usually introduced to
align the input and output sequences for CTC or RNN-T models. Unfortunately,
the long input length overloads computational budget and memory consumption
quadratically by attention mechanism. In this work, we propose a
"Skip-and-Recover" Conformer architecture, named Skipformer, to squeeze
sequence input length dynamically and inhomogeneously. Skipformer uses an
intermediate CTC output as criteria to split frames into three groups: crucial,
skipping and ignoring. The crucial group feeds into next conformer blocks and
its output joint with skipping group by original temporal order as the final
encoder output. Experiments show that our model reduces the input sequence
length by 31 times on Aishell-1 and 22 times on Librispeech corpus. Meanwhile,
the model can achieve better recognition accuracy and faster inference speed
than recent baseline models. Our code is open-sourced and available online.Comment: Accepted by ICME202
Streaming Decoder-Only Automatic Speech Recognition with Discrete Speech Units: A Pilot Study
Unified speech-text models like SpeechGPT, VioLA, and AudioPaLM have shown
impressive performance across various speech-related tasks, especially in
Automatic Speech Recognition (ASR). These models typically adopt a unified
method to model discrete speech and text tokens, followed by training a
decoder-only transformer. However, they are all designed for non-streaming ASR
tasks, where the entire speech utterance is needed during decoding. Hence, we
introduce a decoder-only model exclusively designed for streaming recognition,
incorporating a dedicated boundary token to facilitate streaming recognition
and employing causal attention masking during the training phase. Furthermore,
we introduce right-chunk attention and various data augmentation techniques to
improve the model's contextual modeling abilities. While achieving streaming
speech recognition, experiments on the AISHELL-1 and -2 datasets demonstrate
the competitive performance of our streaming approach with non-streaming
decoder-only counterparts.Comment: Accepted for Interspeech 202
Benefits and risks of the hormetic effects of dietary isothiocyanates on cancer prevention
The isothiocyanate (ITC) sulforaphane (SFN) was shown at low levels (1-5 µM) to promote cell proliferation to 120-143% of the controls in a number of human cell lines, whilst at high levels (10-40 µM) it inhibited such cell proliferation. Similar dose responses were observed for cell migration, i.e. SFN at 2.5 µM increased cell migration in bladder cancer T24 cells to 128% whilst high levels inhibited cell migration. This hormetic action was also found in an angiogenesis assay where SFN at 2.5 µM promoted endothelial tube formation (118% of the control), whereas at 10-20 µM it caused significant inhibition. The precise mechanism by which SFN influences promotion of cell growth and migration is not known, but probably involves activation of autophagy since an autophagy inhibitor, 3-methyladenine, abolished the effect of SFN on cell migration. Moreover, low doses of SFN offered a protective effect against free-radical mediated cell death, an effect that was enhanced by co-treatment with selenium. These results suggest that SFN may either prevent or promote tumour cell growth depending on the dose and the nature of the target cells. In normal cells, the promotion of cell growth may be of benefit, but in transformed or cancer cells it may be an undesirable risk factor. In summary, ITCs have a biphasic effect on cell growth and migration. The benefits and risks of ITCs are not only determined by the doses, but are affected by interactions with Se and the measured endpoint
Global selfsimilarity of dense granular flow in hopper: the role of hopper width
The influence of hopper width on dense granular flow in a twodimensional
hopper is investigated through experiments and simulations. Though the flow
rate remains stable for larger hopper widths, a slight reduction in hopper
width results in a significant increase in flow rate for smaller hopper widths.
Both Beverloos and Jandas formula accurately capture the relationship
between the flow rate and outlet size. Flow characteristics in the regions near
the outlet exhibit local selfsimilarity, supporting Beverloo and Janda's
principles. Moreover, global selfsimilarity is analysed, indicated by the
transition in flow state from mass flow in regions far from the outlet to
funnel flow near the outlet. The earlier occurrence of this transition favors
to enhance the grain velocity and consequently increases the dense flow rate.
An exponential scaling law is proposed to describe the dependencies of flow
rate, grain velocity, and transition height between the mass flow pattern and
the funnel flow pattern on silo width.Comment: 17 papges, 9 figure
The Structure and Morphology of Galaxies during the Epoch of Reionization Revealed by JWST
We analyze 347 galaxies at redshift using JWST observations from
the CEERS program by fitting a two-dimensional parametric model simultaneously
to the seven-filter NIRCam images to measure the overall structural parameters
and quantify the global properties of the galaxies in the rest-frame optical
band. Particular attention is devoted to deriving robust uncertainties that
include, among other factors, the influence of cosmological surface brightness
dimming and resolution effects. Using the global S\'ersic index () and
observed axial ratio () as a guide, we place a conservative lower
limit of on the incidence of galactic disks. Galaxies follow a
relation between rest-frame optical luminosity and effective radius in the
redshift range , as well as separately over the intervals
and , with a very similar slope but a marginally lower zero
point in the higher redshift bin ( kpc) compared to the
lower redshift bin ( kpc). Within the limitations of the
current sample size, we find no significant redshift evolution of or
at these early epochs.Comment: 23 pages, 17 figures, 2 tables, accepted for publication in The
Astrophysical Journa
Effects of acute administration of different doses of methylphenidate on cognition in healthy young
Os chamados ampliadores cognitivos têm sido ampla e crescentemente utilizados por indivíduos saudáveis, que apesar de não apresentarem nenhum tipo de patologia, buscam por melhoras no desempenho cognitivo. Um fármaco utilizado para este fim é o metilfenidato, droga de primeira escolha para tratamento do transtorno de déficit de atenção e hiperatividade (TDAH). O presente estudo visou verificar o efeito da administração aguda de diferentes doses de metilfenidato (10, 20 e 40 mg e placebo) sobre uma ampla gama de funções cognitivas em jovens saudáveis. Participaram do estudo 36 jovens universitários ou graduados, tendo sido realizados testes de atenção, memória operacional, episódica e semântica. Não foram observadas diferenças no desempenho dos sujeitos em nenhum dos testes. Houve efeito na auto-avaliação de bem estar, sendo este efeito dose dependente – 40 mg > placebo. De acordo com a literatura recente, medicações psicoestimulantes, como o metilfenidato, produzem melhoras no desempenho quando os processos cognitivos estão abaixo de um nível ótimo o que não era o caso dos sujeitos do presente estudo. Sendo assim, a impressão que o metilfenidato melhora o desempenho cognitivo em pessoas jovens e saudáveis se deve provavelmente ao efeito subjetivo de bem estar.The so called cognitive enhancers have been widely and increasingly used by healthy individuals, who despite not having any kind of pathology, seek improvements in cognitive performance. A drug used for this purpose is methylphenidate, a first choice drug for the treatment of the attention deficit and hyperactivity disorder (ADHD). This study aimed to evaluate the effect of acute administration of different doses of methylphenidate (10, 20 and 40 mg and placebo) in a wide range of cognitive functions in healthy young subjects. Participated in the study 36 university students or graduates, and were applied tests of attention, working memory, episodic and semantic memory. There were no differences among the groups in any of the tests. Significant effect on self-assessment of well being was observed, and this effect was dose dependent - 40 mg> placebo. According to recent literature, psychostimulant medications such as methylphenidate, produce improvements in performance when cognitive processes are below an optimal level which was not the case of the subjects of this study. Thus, the impression that methylphenidate improves cognitive performance in healthy young people is probably due to the effect of subjective well-being.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Associação Fundo de Incentivo à Psicofarmacologia (AFIP)BV UNIFESP: Teses e dissertaçõe
CoNav: A Benchmark for Human-Centered Collaborative Navigation
Human-robot collaboration, in which the robot intelligently assists the human
with the upcoming task, is an appealing objective. To achieve this goal, the
agent needs to be equipped with a fundamental collaborative navigation ability,
where the agent should reason human intention by observing human activities and
then navigate to the human's intended destination in advance of the human.
However, this vital ability has not been well studied in previous literature.
To fill this gap, we propose a collaborative navigation (CoNav) benchmark. Our
CoNav tackles the critical challenge of constructing a 3D navigation
environment with realistic and diverse human activities. To achieve this, we
design a novel LLM-based humanoid animation generation framework, which is
conditioned on both text descriptions and environmental context. The generated
humanoid trajectory obeys the environmental context and can be easily
integrated into popular simulators. We empirically find that the existing
navigation methods struggle in CoNav task since they neglect the perception of
human intention. To solve this problem, we propose an intention-aware agent for
reasoning both long-term and short-term human intention. The agent predicts
navigation action based on the predicted intention and panoramic observation.
The emergent agent behavior including observing humans, avoiding human
collision, and navigation reveals the efficiency of the proposed datasets and
agents
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