2,247 research outputs found
Striking circadian neuron diversity and cycling of Drosophila alternative splicing.
Although alternative pre-mRNA splicing (AS) significantly diversifies the neuronal proteome, the extent of AS is still unknown due in part to the large number of diverse cell types in the brain. To address this complexity issue, we used an annotation-free computational method to analyze and compare the AS profiles between small specific groups of Drosophila circadian neurons. The method, the Junction Usage Model (JUM), allows the comprehensive profiling of both known and novel AS events from specific RNA-seq libraries. The results show that many diverse and novel pre-mRNA isoforms are preferentially expressed in one class of clock neuron and also absent from the more standard Drosophila head RNA preparation. These AS events are enriched in potassium channels important for neuronal firing, and there are also cycling isoforms with no detectable underlying transcriptional oscillations. The results suggest massive AS regulation in the brain that is also likely important for circadian regulation
Effects of Al doping on phase transition and thermoelectric properties of β–Zn4Sb3
AbstractIn this paper, Al-doped Zn4Sb3 compounds (Zn1-xAlx)4Sb3 (x=0,0.0025,0.005) were prepared by using the method consisting of high-temperature melting, rapid cooling and hot-pressing(300°C) under a high pressure. (Zn1-xAlx)4Sb3 has been investigated by low-temperature internal friction (IF) measurements and DSC respectively, the IF measurements show that there is internal friction-peak between 258K and 263K. The peak intensities become lower for higher frequencies but the peak positions are fixed with increasing frequency. It have the typical IF features of phase transition. DSC measurements show that the phase transition is reversible. With the increase of Al doping the phase transition enthalpy increased, the apparent activation energies increased from about 214KJ/mol to 238KJ/mol, prompted Al doping could partially inhibit the phase transition. In addition, high-temperature thermoelectric properties of (Zn1-xAlx)4Sb3 were investigated. The results indicated that resistively and thermo power of the doped compound (Zn1-xAlx)4Sb3 (x≠0) increased remarkably as compared to that of Zn4Sb3, the power factor of (Zn1-xAlx)4Sb3 increased between room temperature and 420K, but decreased in the hot parts
Stability Criteria for Neural Networks with Two Additive Time-varying Delay Components
This paper is concerned with the stability problem with two additive time-varying delay components. By choosing one augmented Lyapunov-Krasovskii functional, using some new zero equalities, and combining linear matrix inequalities (LMI) techniques, two new sufficient criteria ensuring the global stability asymptotic stability of DNNs is obtained. These stability criteria are present in terms of linear matrix inequalities and can be easily checked. Finally, some examples are showed to demonstrate the effectiveness and less conservatism of the proposed method
Stability Criteria for Neural Networks with Two Additive Time-varying Delay Components
This paper is concerned with the stability problem with two additive time-varying delay components. By choosing one augmented Lyapunov-Krasovskii functional, using some new zero equalities, and combining linear matrix inequalities (LMI) techniques, two new sufficient criteria ensuring the global stability asymptotic stability of DNNs is obtained. These stability criteria are present in terms of linear matrix inequalities and can be easily checked. Finally, some examples are showed to demonstrate the effectiveness and less conservatism of the proposed method
Oxygen-vacancy-mediated Negative Differential Resistance in La and Mg co-substituted BiFeO3 Thin Film
The conductive characteristics of Bi0.9La0.1Fe0.96Mg0.04O3(BLFM) thin film
are investigated at various temperatures and a negative differential resistance
(NDR) is observed in the thin film, where a leakage current peak occurs upon
application of a downward electric field above 80 oC. The origin of the NDR
behavior is shown to be related to the ionic defect of oxygen vacancies (VO..)
present in the film. On the basis of analyzing the leakage mechanism and
surface potential behavior, the NDR behavior can be understood by considering
the competition between the polarized distribution and neutralization of VO..
Online Schema Evolution is (Almost) Free for Snapshot Databases
Modern database applications often change their schemas to keep up with the
changing requirements. However, support for online and transactional schema
evolution remains challenging in existing database systems. Specifically, prior
work often takes ad hoc approaches to schema evolution with 'patches' applied
to existing systems, leading to many corner cases and often incomplete
functionality. Applications therefore often have to carefully schedule
downtimes for schema changes, sacrificing availability.
This paper presents Tesseract, a new approach to online and transactional
schema evolution without the aforementioned drawbacks. We design Tesseract
based on a key observation: in widely used multi-versioned database systems,
schema evolution can be modeled as data modification operations that change the
entire table, i.e., data-definition-as-modification (DDaM). This allows us to
support schema almost 'for free' by leveraging the concurrency control
protocol. By simple tweaks to existing snapshot isolation protocols, on a
40-core server we show that under a variety of workloads, Tesseract is able to
provide online, transactional schema evolution without service downtime, and
retain high application performance when schema evolution is in progress.Comment: To appear at Proceedings of the 2023 International Conference on Very
Large Data Bases (VLDB 2023
Adaptive Graph-Based Feature Normalization for Facial Expression Recognition
Facial Expression Recognition (FER) suffers from data uncertainties caused by
ambiguous facial images and annotators' subjectiveness, resulting in excursive
semantic and feature covariate shifting problem. Existing works usually correct
mislabeled data by estimating noise distribution, or guide network training
with knowledge learned from clean data, neglecting the associative relations of
expressions. In this work, we propose an Adaptive Graph-based Feature
Normalization (AGFN) method to protect FER models from data uncertainties by
normalizing feature distributions with the association of expressions.
Specifically, we propose a Poisson graph generator to adaptively construct
topological graphs for samples in each mini-batches via a sampling process, and
correspondingly design a coordinate descent strategy to optimize proposed
network. Our method outperforms state-of-the-art works with accuracies of
91.84% and 91.11% on the benchmark datasets FERPlus and RAF-DB, respectively,
and when the percentage of mislabeled data increases (e.g., to 20%), our
network surpasses existing works significantly by 3.38% and 4.52%
Movable Antenna Enabled Interference Network: Joint Antenna Position and Beamforming Design
This paper investigates the utility of movable antenna (MA) assistance for
the multiple-input single-output (MISO) interference channel. We exploit an
additional design degree of freedom provided by MA to enhance the desired
signal and suppress interference so as to reduce the total transmit power of
interference network. To this end, we jointly optimize the MA positions and
transmit beamforming, subject to the signal-to-interference-plus-noise ratio
constraints of users. To address the non-convex optimization problem, we
propose an efficient iterative algorithm to alternately optimize the MA
positions via successive convex approximation method and the transmit
beamforming via second-order cone program approach. Numerical results
demonstrate that the proposed MA-enabled MISO interference network outperforms
its conventional counterpart without MA, which significantly enhances the
capability of inter-cell frequency reuse and reduces the complexity of
transmitter design
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