On Designs of Decentralized Reputation Management for Permissioned Blockchain Networks

In permissioned blockchain networks,the Proof of Authority(PoA)consensus,which uses the election of authorized nodes to validate transactions and blocks,has beenwidely advocated thanks to its high transaction throughput and fault tolerance.However,PoA suffers from the drawback of centralization dominated by a limited number of authorized nodes and the lack of anonymity due to the round-robin block proposal mechanism.As a result,traditional PoA is vulnerable to a single point of failure that compromises the security of the blockchain network.To address these issues,we propose a novel decentralized reputation management mechanism for permissioned blockchain networks to enhance security,promote liveness,and mitigate centralization while retaining the same throughput as traditional PoA.This paper aims to design an off-chain reputation evaluation and an on-chain reputation-aided consensus.First,we evaluate the nodes’reputation in the context of the blockchain networks and make the reputation globally verifiable through smart contracts.Second,building upon traditional PoA,we propose a reputation-aided PoA(rPoA)consensus to enhance securitywithout sacrificing throughput.In particular,rPoA can incentivize nodes to autonomously form committees based on reputation authority,which prevents block generation from being tracked through the randomness of reputation variation.Moreover,we develop a reputation-aided fork-choice rule for rPoA to promote the network’s liveness.Finally,experimental results show that the proposed rPoA achieves higher security performance while retaining transaction throughput compared to traditional PoA.

互花米草NAC转录因子家族的鉴定与表达分析

互花米草(Spartina alterniflora)作为一种海岸带盐生植物,高度耐盐胁迫,但因为缺少参考基因组,其耐盐的分子机制却尚未见报道。NAC家族蛋白是植物特有的转录因子,调控植物的生长发育和胁迫应答。为了鉴定互花米草NAC蛋白(SaNAC)并探究它们与互花米草生长发育及胁迫响应之间的关系,本研究以互花米草三代全长转录组数据为参考,通过与水稻(Oryza sativa)、拟南芥(Arabidopsis thaliana)和玉米(Zea mays)NAC蛋白序列进行比对,并结合保守功能域进一步筛选,最终找到62个SaNAC蛋白。从蛋白序列比对、进化、motif预测、同源性比较、亚细胞定位、组织表达以及非生物胁迫下的基因差异表达等方面分别对互花米草NAC家族成员进行分析,结果发现SaNAC蛋白均含有保守的NAM结构域,且在进化上与水稻NAC家族具有一定的相似性;SaNAC家族中的两个蛋白SaNAC9和SaNAC49在细胞核表达;另外,本研究还发现互花米草SaNAC基因表达具有高度组织和胁迫应答差异性。这些结果表明互花米草NAC转录因子家族不仅具有保守的功能域,而且在调控互花米草的生长发育和非生物胁迫响应过程中具有重要的作用。

NiFeCoAlOOH纳米颗粒修饰钛掺杂纳米多孔赤铁矿光阳极用于高效光电化学水分解

本文利用一种简单的化学配体控制氧化方法,将NiFeCoAlOOH纳米颗粒负载在钛掺杂的纳米多孔赤铁矿光阳极上(Ti-PH),并将其用于光电催化水分解、由于NiFeCoAlOOH能够帮助提升Ti-PH光阳极的析氧反应动力学并且降低表面电荷转移电阻,修饰后的光阳极相对于1.23 V us.RHE时具有2.46 mA/cm^(2)的光电流密度,并且与Ti-PH或空白赤铁矿光阳极相比具有更好的稳定性.此外,对比钛掺杂的纳米多孔赤铁矿光阳极,NiFeCoAlOOH修饰后的光电流的起始电位负移了~60 mV.这项工作为设计高性能、稳定、廉价的光电化学电池提供了一种具有潜力的催化剂修饰方法.

A molecular cobaloxime cocatalyst and ultrathin FeOOH nanolayers co-modifiedBiVO_(4) photoanode for efficient photoelectrochemical water oxidation

BiVO_(4) has been attracting a lot of interest in photoelectrochemical (PEC) water oxidation due to its efficient solar absorption and appropriate band positions.So far,sluggish water oxidation kinetics and fast photogenerated charge recombination still hinder the PEC performance ofBiVO_(4) .In this study,a novel PEC photoanode was designed by depositing ultrathin FeOOH nanolayers on the surface of nanoporousBiVO_(4) electrode,followed by modification with a cobaloxime (Co(dmgH)_(2)(4-COOH-py)Cl) molecular cocatalyst.Under irradiation of a 100 mW cm^(-2)(AM 1.5G) Xe lamp,the photocurrent density of the cobaloxime/FeOOH/BiVO_(4) composite photoanode reached 5.1 mA cm^(-2)at 1.23 V vs.RHE in 1.0 M potassium borate buffer solution (pH=9.0).The onset potential of the optimal cobaloxime/FeOOH/BiVO_(4) photoanode exhibited a 460 m V cathodic shift relative to bareBiVO_(4) .In addition,the surface charge injection efficiency of the composite photoanode reached~80%at 1.23 V vs.RHE and the incident photon-to-current efficiency (IPCE) reached~88%at 420 nm.

Self-supported Ni2P nanosheets on low-cost three-dimensional Fe foam as a novel electrocatalyst for efficient water oxidation

Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction(OER)is considered as the bottleneck reaction in an overall water splitting system because it involves 4e- and 4H+ transfer processes.Currently,it is highly desirable to explore low-cost alternative catalysts for OER at ambient conditions.Herein,we report for the first time that nickel phosphide(Ni2P)nanosheets can be facilely grown on Fe foam(FF)as an efficient electrocatalyst for OER with excellent durability and catalytic activity under alkaline conditions.To reach a current density of 10 m A/cm2,the Ni2P-FF catalyst required a low overpotential of only 198 mV for OER.The catalyst’s high OER activity and durability were well maintained at a high current density.The required overpotentials were only 267 and 313 mV to achieve the current densities of 100 and 300 m A/cm2,respectively.The combination of low-cost Fe foam with Ni2P provides a promising low-cost catalyst for large-scale application of electrocatalytic water splitting.

SlBBX20 interacts with the COP9 signalosome subunit SlCSN5-2 to regulate anthocyanin biosynthesis by activating SlDFR expression in tomato

Anthocyanins play vital roles in plant stress tolerance and growth regulation.Previously,we reported that the photomorphogenesis-related transcription factor SlBBX20 regulates anthocyanin accumulation in tomato.However,the underlying mechanism remains unclear.Here,we showed that SlBBX20 promotes anthocyanin biosynthesis by binding the promoter of the anthocyanin biosynthesis gene SlDFR,suggesting that SlBBX20 directly activates anthocyanin biosynthesis genes.Furthermore,we found by yeast two-hybrid screening that SlBBX20 interacts with the COP9 signalosome subunit SlCSN5-2,and the interaction was confirmed by bimolecular fluorescence complementation and coimmunoprecipitation assays.SlCSN5 gene silencing led to anthocyanin hyperaccumulation in the transgenic tomato calli and shoots,and SlCSN5-2 overexpression decreased anthocyanin accumulation,suggesting thSlCSN5-2 enhanced the ubiquitination of SlBBX20 and promoted the degradation of SlBBX20 in vivo.Consistently,silencing the SlCSN5-2 homolog in tobacco significantly increased the accumulation of the SlBBX20 protein.Since SlBBX20 is a vital regulator of photomorphogenesis,the SlBBX20-SlCSN5-2 module may represent a novel regulatory pathway in light-induced anthocyanin biosynthesis.

The loss of function of HEL,which encodes a cellulose synthase interactive protein,causes helical and vine-like growth of tomato

Helical growth is an economical way for plant to obtain resources.The classic microtubule–microfibril alignment model of Arabidopsis helical growth involves restriction of the appropriate orientation of cellulose microfibrils appropriately in the cell walls.However,the molecular mechanism underlying tomato helical growth remains unknown.Here,we identified a spontaneous tomato helical(hel)mutant with right-handed helical cotyledons and petals but left-handed helical stems and true leaves.Genetic analysis revealed that the hel phenotype was controlled by a single recessive gene.Using map-based cloning,we cloned the HEL gene,which encodes a cellulose interacting protein homologous to CSI1 of Arabidopsis.We identified a 27 bp fragment replacement that generated a premature stop codon.Transgenic experiments showed that the helical growth phenotype could be restored by the allele of this gene from wild-type Pyriforme.In contrast,the knockout mutation of HEL in Pyriforme via CRISPR/Cas9 resulted in helical growth.These findings shed light on the molecular control of the helical growth of tomato.

基于博弈论分析的数字创意平台投票机制

数字技术和互联网技术的新进展推动数字创意产业进入了新时代,数字创意产业也面临着一系列新的挑战。区块链作为一项颠覆性的技术,其技术特点能够给数字创意产业带来很多新的应用,尤其是区块链中的一种非同质化代币(Non-Fungible Token,NFT)技术融入到数字创意产业中能够给该产业带来新的变革。然而,数字创意作品平台系统因“零门槛”进入而面临低质量作品泛滥的问题。本文提出在作品被平台收纳之前应引入投票机制来解决该问题。我们首先为平台中的创作者建立基于博弈论的经济模型,并对比分析均分机制、比例机制以及投票机制在达到对称均衡时创作者产出作品质量的情况。通过博弈论理论分析与计算机仿真实验表明,在引入投票机制之后,系统可以通过改变总奖励的方式有效激励创作者上传更高质量的作品到平台中,从而自动过滤低质量作品。

Cyclin gene SlCycB1 alters plant architecture in association with histone H3.2 in tomato

Cell cycle regulation plays a critical role in plant growth and development.In this study,the role of a tomato cell cycle gene SlCycB1 has been characterized.Expression analysis revealed that SlCycB1 was mostly expressed in stem,root,and leaves,with relative lower expression in flower and fruit.Tomato plants overexpressing SlCycB1 exhibited a reduction in cell number and increased cell size leading to the growth retardation.Furthermore,yeast two-hybrid analysis and bimolecular fluorescence complementation revealed that SlCycB1 interacted with histone H3.2,an essential component of the nucleosome.Histone H3.2 was transcriptionally up-regulated in the SlCycB1 overexpressing tomato lines.Furthermore,the overexpression of histone H3.2 in transgenic plants showed similar phenotypes to SlCycB1 overexpressing lines.Based on these findings,we concluded that SlCycB1 overexpression altered tomato architecture in association with histone H3.2.

The pharmacological and toxicological action of strychnine on central nervous system

Strychnine is the main bioactive constituent responsible for the pharmacological and toxic properties of strychnos nux-vomica L.(Loganiaceae),which is known for severe neurotoxicity.Although its toxic threshold is easy to be reached and it is liable to cause poisoning,the effect of strychnine on the central nervous system(CNS)is crucial for its application in clinic.Therefore,the impacts of pharmacology and toxicology of strychnine on CNS have generated increasing interests.In this short review,we summarize the pharmacological activities,neurotoxicology,underlying mechanisms of the strychnine poisoning,and discuss the pharmacokinetics properties of strychnine.These findings could provide beneficial information for facilitating future mechanism research of neurotoxicity of strychnine and developing drugs to remedy neurotoxicity in the clinic.

High-quality assembled and annotated genomes of Nicotiana tabacum and Nicotiana benthamiana reveal chromosome evolution and changes in defense arsenals

Nicotiana tabacum and Nicotiana benthamiana are widely used models in plant biology research.However,genomic studies of these species have lagged.Here we report the chromosome-level reference genome assemblies for N.benthamiana and N.tabacum with an estimated 99.5%and 99.8%completeness,respec-tively.Sensitive transcription start and termination site sequencing methods were developed and used for accurate gene annotation in N.tabacum.Comparative analyses revealed evidence for the parental origins and chromosome structural changes,leading to hybrid genome formation of each species.Interestingly,theantiviral silencinggenesRDR1,RDR6,DCL2,DCL3,andAGO2were lost from one or both subgenomes in N.benthamiana,while both homeologs were kept in N.tabacum.Furthermore,the N.benthamiana genome encodes fewer immune receptors and signaling components than that of N.tabacum.These find-ings uncover possible reasons underlying the hypersusceptible nature of N.benthamiana.We developed the user-friendly Nicomics(http:/lifenglab.hzau.edu.cn/Nicomics/)web server to facilitate better use of Nicotiana genomic resources as well as gene structure and expression analyses.

Genome-wide Analysis of Plant-specific Dof Transcription Factor Family in Tomato

The Dof （DNA binding with One Finger） family encoding single zinc finger proteins has been known as a family of plant-specific transcription factors. These transcription factors are involved in a variety of functions of importance for different biological processes in plants. In the current study, we identified 34 Dof family genes in tomato （Solanum lycopersicum L.）, distributed on 11 chromosomes. A complete overview of SlDof genes in tomato is presented, including the gene structures, chromosome locations, phylogeny, protein motifs and evolution pattern. Phylogenetic analysis of 34 SlDof proteins resulted in four classes constituting six clusters. In addition, a comparative analysis between these genes in tomato, Arabidopsis （Arabidopsis thaliana L.） and rice （Oryza sativa L.） was also performed. The tomato Dof family expansion has been dated to recent duplication events, and segmental duplication is predominant for the SlDof genes. Furthermore, the SlDof genes displayed differential expression either in their transcript abundance or in their expression patterns under normal growth conditions. This is the first step towards genome-wide analyses of the Dof genes in tomato. Our study provides a very useful reference for cloning and functional analysis of the members of this gene family in tomato and other species.

Modeling of gas porosity and microstructure formation during dendritic and eutectic solidification of ternary Al-Si-Mg alloys

A two-dimensional(2-D)multi-component and multi-phase cellular automaton(CA)model coupled with the Calphad method and finite difference method(FDM)is proposed to simulate the gas pore formation and microstructures in solidification process of hypoeutectic Al-Si-Mg alloys.In this model,the pore growth,and dendritic and eutectic solidification are simulated using a CA technique.To achieve the equilibrium among multiple phases during ternary Al-based alloy solidification,the phase transition thermodynamics and kinetics are evaluated by adopting the Calphad method.The diffusion equations of hydrogen and two solutes are solved by FDM.The developed CA-FDM coupled model can be used for simulating the evolution of gas microporosity and microstructures,involving dendrites and irregular binary and ternary eutectics,of ternary hypoeutectic Al-Si-Mg alloys.It has the capability of reproducing the interactions between the hydrogen microporosity formation and the growth of dendrites and eutectics,the competitive growth among the growing gas pores of different sizes,together with the time-evolving concentration fields of hydrogen and solutes.The simulated morphology of gas pore and microstructure has a good agreement with the experimental observation.The influences of the initial hydrogen concentration and cooling rate on the microporosity formation are investigated.It is found that the main portion of porosity formation occurs in the eutectic solidification stage through analyzing the profiles of porosity percentage and solid fraction varying with solidification time.The varying features of simulated porosity percentage,the maximum and average pores radii indicate that increasing initial hydrogen concentration promotes the formation of higher final porosity percentage and larger pores,while the size of gas pores will significantly reduce with increasing cooling rate,leading to a lower final porosity percentage.

FUNCTIONAL GAIN OF FRUIT NETTED-CRACKING IN AN INTROGRESSION LINE OF TOMATO WITH HIGHER EXPRESSION OF THE FNC GENE

Fruit cracking is a major disorder that affects the integrity of fruit and reduces the commercial value of tomato and other fleshy fruit.Here,we have found a novel fruit'netted-cracking'(FNC)phenotype in tomato introgression line IL4-4 which is present in neither the donor parent(LA0716)nor the receptor parent(M82).An F2 population was generated by crossing IL4-4 with M82 to genetically characterize the FNC gene and this showed that a single dominant gene determined fruit netted-cracking.Further map-based cloning narrowed down the FNC locus to a 230 kb region on chromosome 4.Sequencing and annotation analysis show that FNC(Solyc04 g082540)was the most likely candidate gene.Functional characterization of FNC by overexpressing FNC^c and FNC1^resulted in the fruit netted-cracking phenotype,suggesting that the FNC transcript level results in the functional gain of fruit netted-cracking.These findings were further confirmed by FNC ortholog in netted-cracking pepper and melon,indicating a common regulatory mechanism in different plant species.Furthermore,cytoplasm and nucleus-localized FNC indicates increased expression of genes involved in suberin,lignin,lipid transport and cell wall metabolism.These findings provide novel genetic insights into fruit netted-cracking and offer a way to promote molecular improvement toward cracking resistant cultivars.