389 research outputs found
A Numerical Analysis to the {} and {K} Coupled--Channel Scalar Form-factor
A numerical analysis to the scalar form-factor in the and KK
coupled--channel system is made by solving the coupled-channel dispersive
integral equations, using the iteration method. The solutions are found not
unique. Physical application to the central production in the process is discussed based upon the numerical solutions we found.Comment: 8 pages, Latex, 3 figures. Minor changes and one reference adde
Sharp estimates and non-degeneracy of low energy nodal solutions for the Lane-Emden equation in dimension two
We study the Lane-Emden problem where is a smooth bounded domain and
is sufficiently large. We obtain sharp estimates and non-degeneracy of
low energy nodal solutions (i.e. nodal solutions satisfying
). As applications, we
prove that the comparable condition
holds automatically for least
energy nodal solutions, which confirms a conjecture raised by
(Grossi-Grumiau-Pacella, Ann.I.H. Poincare-AN, 30 (2013), 121-140) and
(Grossi-Grumiau-Pacella, J.Math.Pures Appl. 101 (2014), 735-754)
StyleBART: Decorate Pretrained Model with Style Adapters for Unsupervised Stylistic Headline Generation
Stylistic headline generation is the task to generate a headline that not
only summarizes the content of an article, but also reflects a desired style
that attracts users. As style-specific article-headline pairs are scarce,
previous researches focus on unsupervised approaches with a standard headline
generation dataset and mono-style corpora. In this work, we follow this line
and propose StyleBART, an unsupervised approach for stylistic headline
generation. Our method decorates the pretrained BART model with adapters that
are responsible for different styles and allows the generation of headlines
with diverse styles by simply switching the adapters. Different from previous
works, StyleBART separates the task of style learning and headline generation,
making it possible to freely combine the base model and the style adapters
during inference. We further propose an inverse paraphrasing task to enhance
the style adapters. Extensive automatic and human evaluations show that
StyleBART achieves new state-of-the-art performance in the unsupervised
stylistic headline generation task, producing high-quality headlines with the
desired style.Comment: Findings of EMNLP 202
Flavonoids activate pregnane × receptor-mediated CYP3A4 gene expression by inhibiting cyclin-dependent kinases in HepG2 liver carcinoma cells
<p>Abstract</p> <p>Background</p> <p>The expression of the drug-metabolizing enzyme cytochrome P450 3A4 (CYP3A4) is regulated by the pregnane × receptor (PXR), which is modulated by numerous signaling pathways, including the cyclin-dependent kinase (Cdk) pathway. Flavonoids, commonly consumed by humans as dietary constituents, have been shown to modulate various signaling pathways (e.g., inhibiting Cdks). Flavonoids have also been shown to induce <it>CYPs </it>expression, but the underlying mechanism of action is unknown. Here, we report the mechanism responsible for flavonoid-mediated PXR activation and <it>CYP </it>expression.</p> <p>Results</p> <p>In a cell-based screen designed to identify compounds that activate PXR-mediated <it>CYP3A4 </it>gene expression in HepG2 human carcinoma cells, we identified several flavonoids, such as luteolin and apigenin, as PXR activators. The flavonoids did not directly bind to PXR, suggesting that an alternative mechanism may be responsible for flavonoid-mediated PXR activation. Consistent with the Cdk5-inhibitory effect of flavonoids, Cdk5 and p35 (a non-cyclin regulatory subunit required to activate Cdk5) were expressed in HepG2. The activation of Cdk5 attenuated PXR-mediated <it>CYP3A4 </it>expression whereas its downregulation enhanced it. The Cdk5-mediated downregulation of <it>CYP3A4 </it>promoter activity was restored by flavonoids, suggesting that flavonoids activate PXR by inactivating Cdk5. <it>In vitro </it>kinase assays showed that Cdk5 directly phosphorylates PXR. The Cdk kinase profiling assay showed that apigenin inhibits multiple Cdks, suggesting that several Cdks may be involved in activation of PXR by flavonoids.</p> <p>Conclusions</p> <p>Our results for the first time link the stimulatory effect of flavonoids on <it>CYP </it>expression to their inhibitory effect on Cdks, through a PXR-mediated mechanism. These results may have important implications on the pharmacokinetics of drugs co-administered with herbal remedy and herbal-drug interactions.</p
Note on off-shell relations in nonlinear sigma model
In this note, we investigate relations between tree-level off-shell currents
in nonlinear sigma model. Under Cayley parametrization, all odd-point currents
vanish. We propose and prove a generalized identity for even-point
currents. The off-shell identity given in [1] is a special case of the
generalized identity studied in this note. The on-shell limit of this identity
is equivalent with the on-shell KK relation. Thus this relation provides the
full off-shell correspondence of tree-level KK relation in nonlinear sigma
model.Comment: 28 pages, 1 table, 11 figures, improved versio
MASTERKEY: Practical Backdoor Attack Against Speaker Verification Systems
Speaker Verification (SV) is widely deployed in mobile systems to
authenticate legitimate users by using their voice traits. In this work, we
propose a backdoor attack MASTERKEY, to compromise the SV models. Different
from previous attacks, we focus on a real-world practical setting where the
attacker possesses no knowledge of the intended victim. To design MASTERKEY, we
investigate the limitation of existing poisoning attacks against unseen
targets. Then, we optimize a universal backdoor that is capable of attacking
arbitrary targets. Next, we embed the speaker's characteristics and semantics
information into the backdoor, making it imperceptible. Finally, we estimate
the channel distortion and integrate it into the backdoor. We validate our
attack on 6 popular SV models. Specifically, we poison a total of 53 models and
use our trigger to attack 16,430 enrolled speakers, composed of 310 target
speakers enrolled in 53 poisoned models. Our attack achieves 100% attack
success rate with a 15% poison rate. By decreasing the poison rate to 3%, the
attack success rate remains around 50%. We validate our attack in 3 real-world
scenarios and successfully demonstrate the attack through both over-the-air and
over-the-telephony-line scenarios.Comment: Accepted by Mobicom 202
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