552 research outputs found
The structure and regulation of Cullin 2 based E3 ubiquitin ligases and their biological functions.
BACKGROUND: Cullin-RING E3 ubiquitin ligase complexes play a central role in targeting cellular proteins for ubiquitination-dependent protein turnover through 26S proteasome. Cullin-2 is a member of the Cullin family, and it serves as a scaffold protein for Elongin B and C, Rbx1 and various substrate recognition receptors to form E3 ubiquitin ligases.
MAIN BODY OF THE ABSTRACT: First, the composition, structure and the regulation of Cullin-2 based E3 ubiquitin ligases were introduced. Then the targets, the biological functions of complexes that use VHL, Lrr-1, Fem1b, Prame, Zyg-11, BAF250, Rack1 as substrate targeting subunits were described, and their involvement in diseases was discussed. A small molecule inhibitor of Cullins as a potential anti-cancer drug was introduced. Furthermore, proteins with VHL box that might bind to Cullin-2 were described. Finally, how different viral proteins form E3 ubiquitin ligase complexes with Cullin-2 to counter host viral defense were explained.
CONCLUSIONS: Cullin-2 based E3 ubiquitin ligases, using many different substrate recognition receptors, recognize a number of substrates and regulate their protein stability. These complexes play critical roles in biological processes and diseases such as cancer, germline differentiation and viral defense. Through the better understanding of their biology, we can devise and develop new therapeutic strategies to treat cancers, inherited diseases and viral infections
Herding Effect based Attention for Personalized Time-Sync Video Recommendation
Time-sync comment (TSC) is a new form of user-interaction review associated
with real-time video contents, which contains a user's preferences for videos
and therefore well suited as the data source for video recommendations.
However, existing review-based recommendation methods ignore the
context-dependent (generated by user-interaction), real-time, and
time-sensitive properties of TSC data. To bridge the above gaps, in this paper,
we use video images and users' TSCs to design an Image-Text Fusion model with a
novel Herding Effect Attention mechanism (called ITF-HEA), which can predict
users' favorite videos with model-based collaborative filtering. Specifically,
in the HEA mechanism, we weight the context information based on the semantic
similarities and time intervals between each TSC and its context, thereby
considering influences of the herding effect in the model. Experiments show
that ITF-HEA is on average 3.78\% higher than the state-of-the-art method upon
F1-score in baselines.Comment: ACCEPTED for ORAL presentation at IEEE ICME 201
Ultrashort-pulse laser calligraphy
Control of structural modifications inside silica glass by changing the front tilt of an ultrashort pulse is demonstrated, achieving a calligraphic style of laser writing. The phenomena of anisotropic bubble formation at the boundary of an irradiated region and modification transition from microscopic bubbles formation to self-assembled form birefringence are observed, and the physical mechanisms are discussed. The results provide the comprehensive evidence that the light beam with centrosymmetric intensity distribution can produce noncentrosymmetric material modifications
Extremal properties of the first eigenvalue and the fundamental gap of a sub-elliptic operator
We consider the problems of extreming the first eigenvalue and the
fundamental gap of a sub-elliptic operator with Dirichlet boundary condition,
when the potential is subjected to a -norm constraint. The existence
results for weak solutions, compact embedding theorem and spectral theory for
sub-elliptic equation are given. Moreover, we provide the specific
characteristics of the corresponding optimal potential function
Optimal Actuator Location of the Norm Optimal Controls for Degenerate Parabolic Equations
This paper focuses on investigating the optimal actuator location for
achieving minimum norm controls in the context of approximate controllability
for degenerate parabolic equations. We propose a formulation of the
optimization problem that encompasses both the actuator location and its
associated minimum norm control. Specifically, we transform the problem into a
two-person zero-sum game problem, resulting in the development of four
equivalent formulations. Finally, we establish the crucial result that the
solution to the relaxed optimization problem serves as an optimal actuator
location for the classical problem
Null controllability of two kinds of coupled parabolic systems with switching control
The focus of this paper is on the null controllability of two kinds of
coupled systems including both degenerate and non-degenerate equations with
switching control. We first establish the observability inequality for
measurable subsets in time for such coupled system, and then by the HUM method
to obtain the null controllability. Next, we investigate the null
controllability of such coupled system for segmented time intervals. Notably,
these results are obtained through spectral inequalities rather than using the
method of Carleman estimates. Such coupled systems with switching control, to
the best of our knowledge, are among the first to discuss
A Scope Sensitive and Result Attentive Model for Multi-Intent Spoken Language Understanding
Multi-Intent Spoken Language Understanding (SLU), a novel and more complex
scenario of SLU, is attracting increasing attention. Unlike traditional SLU,
each intent in this scenario has its specific scope. Semantic information
outside the scope even hinders the prediction, which tremendously increases the
difficulty of intent detection. More seriously, guiding slot filling with these
inaccurate intent labels suffers error propagation problems, resulting in
unsatisfied overall performance. To solve these challenges, in this paper, we
propose a novel Scope-Sensitive Result Attention Network (SSRAN) based on
Transformer, which contains a Scope Recognizer (SR) and a Result Attention
Network (RAN). Scope Recognizer assignments scope information to each token,
reducing the distraction of out-of-scope tokens. Result Attention Network
effectively utilizes the bidirectional interaction between results of slot
filling and intent detection, mitigating the error propagation problem.
Experiments on two public datasets indicate that our model significantly
improves SLU performance (5.4\% and 2.1\% on Overall accuracy) over the
state-of-the-art baseline
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