Probing neutral top-pion via a flavor-changing process γγ→tcˉΠt0\gamma\gamma\to t\bar{c}\Pi_{t}^{0}

In the framework of topcolor-assisted-technicolor model(TC2), we study a flavor-changing neutral top-pion production process $\gamma\gamma\to t\bar{c}\Pi_{t}^{0}$. The study shows that there exists a resonance effect which can enhance the cross section up to a few fb even tens fb. For a yearly luminosity 100 $fb^{-1}$ at future linear colliders, there might be hundreds even thousands events to be produced. On the other hand, the background of such flavor-changing process is very clean due to the GIM mechanism in SM . With such sufficient events and clean background, neutral toppion could be detected at future linear colliders with high center of energy and luminosity. Our study provides a possible way to test TC2 model.Comment: 10 pages, 4 figures,has been accepted by Phys.Rev.

Detecting the neutral top-pion at e+e−e^{+}e^{-} colliders

We investigate some processes of the associated production of a neutral top-pion $\Pi^{0}_{t}$ with a pair of fermions($e^{+}e^{-}\to f\bar{f}\Pi^{0}_{t}$) in the context of top-color-assisted technicolor(TC2) theory at future $e^{+}e^{-}$ colliders. The studies show that the largest cross sections of the processes $e^{+}e^{-}\to f'\bar{f'}\Pi^{0}_{t}(f'=u,d,c,s,\mu,\tau)$ could only reach the level of 0.01fb, we can hardly detect a neutral top-pion through these processes. For the processes $e^{+}e^{-}\to e^{+}e^{-}\Pi^{0}_{t}$, $e^{+}e^{-}\to t\bar{t}\Pi^{0}_{t}$ and $e^{+}e^{-}\to b\bar{b}\Pi^{0}_{t}$, the cross sections of these processes are at the level of a few fb for the favorable parameters and a few tens, even hundreds, of neutral top-pion events can be produced at future $e^{+}e^{-}$ colliders each year through these processes. With the clean background of the flavor-changing $t\bar{c}$ channel, the top-pion events can possibly be detected at the planned high luminosity $e^{+}e^{-}$ colliders. Therefore, such neutral top-pion production processes provide a useful way to detect a neutral top-pion and test the TC2 model directly.Comment: 13 pages, 4 figure

Evaluation of COMPASS ionospheric grid

As an important component of the augmentation service, the ionospheric grid contributes to improving single-frequency positioning accuracy. The ionospheric delay corrections are broadcast as vertical delay estimates at specified ionospheric grid points (IGPs) for most satellite-based augmentation system, where the IGPs are predefined with a resolution of 5A degrees and 5A degrees in latitude and longitude. Different from the general strategy, the COMPASS IGPs are predefined with a resolution of 2.5A degrees and 5A degrees in latitude and longitude. The need for this special IGPs distribution is investigated with experiments using real data. The performance of the COMPASS ionospheric grid is analyzed in terms of accuracy and availability. Comparing the performance of the special IGPs distribution with that of 5A degrees A xA 5A degrees IGPs, the results show that the ionospheric correction improves by 0.2 m and the 3D positioning accuracy improves by 1 m in middle-low latitude regions. The RMS of the COMPASS grid ionospheric correction accuracy is better than 0.5 m in most regions of the China mainland, and the availability is better than 95 % except in the northeast, northwest and outside China. In addition, we investigated the performance of the method that combined the inverse distance weighted and spherical harmonics grid modeling algorithm. Simulations show that the new method clearly improves grid availability. The mean availability in the mainland is better than 99 %

Research on Construction and SWRL Reasoning of Ontology of Maize Diseases

International audienceIn this paper, according to the characteristics of maize disease knowledge, OWL DL language was used to build maize diseases ontology, and the reasoning rule of maize diseases was defined by using the expressive ability of SWRL rule language.The author introduced several realizable reasoning functions,and achieved the diagnostic reasoning of maize disease knowledge by Jess inference engine.The results indicated that constructing the maize diseases ontology,and introducing SWRL rule into maize disease ontology provided an effective way for the construction of high-intelligent, shareable and reused maize disease knowledge database and diagnostic rule database

Transcriptome and metabolome responses of Shewanella oneidensis MR-1 to methyl orange under microaerophilic and aerobic conditions

Shewanella oneidensis MR-1 degrades various azo dyes under microaerophilic and anaerobic conditions, but this process is inhibited under aerobic conditions. The mechanisms underlying azo dye biodegradation and inhibition remain unknown. Therefore, we investigated metabolic and transcriptional changes in strain MR-1, which was cultured under different conditions, to elucidate these mechanisms. At the transcriptional level, genes involved in certain metabolic processes, particularly the tricarboxylic acid (TCA) cycle, amino acid biodegradation, and the electron transfer system, were significantly altered (M >= 2, p > 0.8 ) in the presence of methyl orange (MO). Moreover, a high concentration of dissolved oxygen heavily impacted the expression levels of genes involved in fatty acid biodegradation. Metabolome analysis revealed significant alteration (p < 0.05) in the concentrations of nine metabolites when strain MR-1 was cultured under aerobic conditions; the majority of these metabolites were closely associated with amino acid metabolism and DNA replication. Accordingly, we propose a possible pathway for MO biodegradation and discuss the most likely causes of biodegradation inhibition due to dissolved oxygen

Itaconate: A promising precursor for treatment of neuroinflammation associated depression

Neuroinflammation triggers the production of inflammatory factors, influences neuron generation and synaptic plasticity, thus playing an important role in the pathogenesis of depression and becoming an important direction of depression prevention and treatment. Itaconate is a metabolite secreted by macrophages in immunomodulatory responses, that has potent immunomodulatory effects and has been proven to exert anti-inflammatory effects in a variety of diseases. Microglia are mononuclear macrophages that reside in the central nervous system (CNS), and may be the source of endogenous itaconate in the brain. Itaconate can directly inhibit succinate dehydrogenase (SDH), reduce the production of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), activate nuclear factor erythroid-2 related factor 2 (Nrf2), and block glycolysis, and thereby improving the depressive symptoms associated with the above mechanisms. Notably, itaconate also indirectly ameliorates the depressive symptoms associated with some inflammatory diseases. With the optimization of the structure and the development of new delivery systems, the application value and therapeutic potential of itaconate have been significantly improved. Dimethyl itaconate (DI) and 4-octyl itaconate (4-OI), cell-permeable derivatives of itaconate, are more suitable for crossing the blood-brain barrier (BBB), exhibiting therapeutic effects in the research of multiple diseases. This article provides an overview of the immunomodulatory effects of itaconate and its potential therapeutic efficacy in inflammatory depression, focusing on the promising application of itaconate as a precursor of antidepressants

A highly reliable encoding and decoding communication framework based on semantic information

Increasing research has focused on semantic communication, the goal of which is to convey accurately the meaning instead of transmitting symbols from the sender to the receiver. In this paper, we design a novel encoding and decoding semantic communication framework, which adopts the semantic information and the contextual correlations between items to optimize the performance of a communication system over various channels. On the sender side, the average semantic loss caused by the wrong detection is defined, and a semantic source encoding strategy is developed to minimize the average semantic loss. To further improve communication reliability, a decoding strategy that utilizes the semantic and the context information to recover messages is proposed in the receiver. Extensive simulation results validate the superior performance of our strategies over state-of-the-art semantic coding and decoding policies on different communication channels

Fabricating Metal@N-Doped Carbon Catalysts via a Thermal Method

Nanoparticles (NPs) encapsulated with carbon material have been proven particularly successful for improving their stability; however, this carbon-coating strategy is a compromise between activity and stability because these carbon shells also reduce, even deactivate, the activity of the catalyst by blocking active sites. Herein, we report a procedure to effectively remove the carbon layer without affecting particle morphology, which enhances the surface exposure of the nanoparticles and their catalytic activity while retaining their stability. The heat treatment, such as reduction in hydrogen atmosphere or calcination in air atmosphere, could destroy the defective carbon-surrounded Ru NPs through making the methanation or oxidation reaction occur on the carbon material surface. More importantly, the heat treatment in air atmosphere at low temperature exhibited higher power to corrode the defective carbon-surrounded Ru NPs in comparison with the heat treatment in hydrogen atmosphere. We anticipate that this defective carbon removal approach has more general applicability to encapsulated metal NPs and should lead to improvements in fields as diverse as chemicals production and environmental protection