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Burning Numbers of Barbells

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 526-538页

作者： Hui-qing LIU Rui-ting ZHANG Xiao-lan HU hubei key laboratory of Applied Mathematics&Faculty of Mathematics and Statistic Hubei UniversityWuhan 430062China hubei key laboratory of mathematical sciences&School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China

Motivated by a discrete-time process intended to measure the speed of the spread of contagion in a graph,the burning number b(G)of a graph G,is defined as the smallest integer k for which there are vertices x1,…xk su... 详细信息

关键词： burning number short/long barbell isometric subtree cycle

Polynomial-Time key-Recovery Attacks Against NTRURe Encrypt from ASIACCS'15

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Journal of Systems Science & Complexity 2024年第3期37卷 1308-1325页

作者： LIU Zhen PAN Yanbin ZHENG Jinwei School of Cyber Science and Technology Hubei Key Laboratory of Applied MathematicsHubei UniversityWuhan 430062China key laboratory of Mathematics Mechanization Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of mathematical sciences University of Chinese Academy of SciencesBeijing 100190China

In ASIACCS 2015, Nu nez, et al. proposed a proxy re-encryption scheme, named NTRURe Encrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a re-encrypted ciphertext that can be decrypted correctly by delegatee’s private key. Because of the potential resistance to quantum algorithm, high efficiency and various applications in real life,NTRURe Encrypt has drawn lots of attention and its security has been widely discussed and *** PQCrypto2019, Liu, et al. proposed two key recovery attacks against it. However, their first attack heavily relies on a weaken decryption oracle, and the second attack needs to collect about 260ciphertexts from the same message by theoretical analysis, which makes both of the attacks unrealistic. In this paper, inspired by the broadcast attack against NTRU, the authors find out that for NTRURe Encrypt the delegator and the delegatee can efficiently recover each other’s private key in polynomial time without any unrealistic assumptions. In addition, the authors also show how to fix NTRURe Encrypt to resist the proposed attacks. As a by-product, the authors also show how to commit broadcast attacks against NTRU 2001 with even dg, which was thought infeasible before.

关键词： Broadcast attack key recovery NTRU NTRUReEncrypt

An accurate and efficient space-time Galerkin spectral method for the subdiffusion equation

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Science China Mathematics 2024年第10期67卷 2387-2408页

作者： Wei Zeng Chuanju Xu School of mathematical sciences and Fujian Provincial key laboratory of mathematical Modeling and High Performance Scientific Computing Xiamen University

In this paper, we design and analyze a space-time spectral method for the subdiffusion ***, we are facing two difficulties. The first is that the solutions of this equation are usually singular near the initial time. Consequently, traditional high-order numerical methods in time are inefficient. The second obstacle is that the resulting system of the space-time spectral approach is usually large and time-consuming to solve. We aim at overcoming the first difficulty by proposing a novel approach in time, which is based on variable transformation techniques. Suitable ψ-fractional Sobolev spaces and a new variational framework are introduced to establish the well-posedness of the associated variational problem. This allows us to construct our space-time spectral method using a combination of temporal generalized Jacobi polynomials(GJPs) and spatial Legendre polynomials. For the second difficulty, we propose a fast algorithm to effectively solve the resulting linear system. The fast algorithm makes use of a matrix diagonalization in space and QZ decomposition in time. Our analysis and numerical experiments show that the proposed method is exponentially convergent with respect to the polynomial degrees in both space and time directions, even though the exact solution has very limited regularity.

关键词： subdiffusion equations variable transformation $\psi$-Sobolev spaces well-posedness space-time Galerkin spectral method error estimate fast algorithm

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Data-Driven Direct Adaptive Risk-Sensitive Control of Stochastic Systems

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Journal of Systems Science & Complexity 2024年第4期37卷 1446-1469页

作者： QIAO Nan LI Tao School of mathematical sciences East China Normal UniversityShanghai 200241China Shanghai key laboratory of Pure Mathematics and mathematical Practice School of Mathematical SciencesEast China Normal UniversityShanghai 200241China

The authors propose a data-driven direct adaptive control law based on the adaptive dynamic programming(ADP) algorithm for continuous-time stochastic linear systems with partially unknown system dynamics and infinite horizon quadratic risk-sensitive *** authors use online data of the system to iteratively solve the generalized algebraic Riccati equation(GARE) and to learn the optimal control law *** the case with measurable system noises,the authors show that the adaptive control law approximates the optimal control law as time goes *** the case with unmeasurable system noises,the authors use the least-square solution calculated only from the measurable data instead of the real solution of the regression equation to iteratively solve the *** authors also study the influences of the intensity of the system noises,the intensity of the exploration noises,the initial iterative matrix,and the sampling period on the convergence of the ADP ***,the authors present two numerical simulation examples to demonstrate the effectiveness of the proposed algorithms.

关键词： Adaptive dynamic programming direct adaptive control generalized algebraic Riccati equation risk-sensitive control

Polyaspers A and B,the First Ergosterol-Polyether Adducts with Unprecedented 6/6/6/5/5/6/6/6/6 Nonacyclic Architecture from Aspergillus ***507

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Chinese Journal of Chemistry 2024年第7期42卷 743-751页

作者： Hong Hu Lanqin Li Zhengyi Shi Xueqi Lan Yeting Zhang Xinye Huang Xincai Hao Qun Zhou Weiguang Sun Changxing Qi Yonghui Zhang hubei key laboratory of Natural Medicinal Chemistry and Resource Evaluation Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430030China Institute of Organ Transplantation Tongji HospitalTongji Medical CollegeHuazhong University of Science and Technology Key Laboratory of Organ TransplantationMinistry of EducationNHC Key Laboratory of Organ TransplantationKey Laboratory of Organ TransplantationChinese Academy of Medical SciencesWuhanHubei 430030China hubei key laboratory of Wudang Local Chinese Medicine Research Hubei Engineering Technology Center for Comprehensive Utilization of Medicinal PlantsCollege of PharmacyHubei University of MedicineShiyanHubei 442000China

Psoriasis is a chronic immune-mediated inflammatory skin disease and the TNF-αis an important therapeutic target of this *** our continuous study of bioactive natural products from fungi,the first ergosterol-polyether adducts,polyaspers A(1)and B(2),along with two known ergosterols,(36,5α,6α,22E)-5,6-epoxy-3-hydroxyergosta-8,22-dien-7-one(3)and calvasterol B(4),were iso-lated from Aspergillus *** elucidation was accomplished by extensive spectroscopic analysis and single-crystal X-ray diffraction *** A and B possessing an unequalled 6/6/6/5/5/6/6/6/6 nonacyclic system,and their biosynthetic path-ways were proposed to include intermolecular cyclization and Diels-Alder *** screen of these isolates showed that 1-3 could improve the cell viability in an actinomycin D/TNF-αinduced L929 cells death model,with the EC50 values of 49.85,46.75 and 4.99μmol/L,respectively,and the activity of 3 was even comparable with that of the positive control *** bioactive investigations discovered 3 could suppress the inflammatory response simulated with TNF-αin HaCaT *** an imiquimod-induced psoriasis murine model,3 significantly restrained the development of psoriasis symptoms and reduced the expression of IL-17 and IL-23,presenting an anti-psoriatic *** such,those ergosterol derivatives,might serve as lead compounds for the development of novel TNF-αinhibitory agents in the clinical treatment of psoriasis.

关键词： Psoriasis Aspergillus sp.TJ507 TNF-α Ergosterol-polyether adducts Inflammatory skin disease

Distributed Least Squares Algorithm of Continuous-Time Stochastic Regression Model Based on Sampled Data

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Journal of Systems Science & Complexity 2024年第2期37卷 609-628页

作者： ZHU Xinghua GAN Die LIU Zhixin The key laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciencesand School of Mathematical SciencesUniversity of Chinese Academy of SciencesBeijing 100190China Zhongguancun laboratory Beijing 100094China

In this paper,the authors consider the distributed adaptive identification problem over sensor networks using sampled data,where the dynamics of each sensor is described by a stochastic differential *** minimizing a local objective function at sampling time instants,the authors propose an online distributed least squares algorithm based on sampled data.A cooperative non-persistent excitation condition is introduced,under which the convergence results of the proposed algorithm are established by properly choosing the sampling time *** upper bound on the accumulative regret of the adaptive predictor can also be ***,the authors demonstrate the cooperative effect of multiple sensors in the estimation of unknown parameters by computer simulations.

关键词： Cooperative excitation condition distributed least squares regret sampled data stochastic differential equation

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An oscillation-free Hermite WENO scheme for hyperbolic conservation laws

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Science China Mathematics 2024年第2期67卷 431-454页

作者： Zhuang Zhao Jianxian Qiu School of mathematical sciences and Institute of Natural sciences Shanghai Jiao Tong UniversityShanghai 200240China School of mathematical sciences and Fujian Provincial key laboratory of mathematical Modeling and High-Performance Scientific Computing Xiamen UniversityXiamen 361005China

In this paper, the sixth-order oscillation-free Hermite weighted essentially non-oscillatory (OFHWENO) scheme is proposed for hyperbolic conservation laws on structured meshes, where the zeroth- andfirst-order moments are the variables for the governing equations. The main difference from other HWENOschemes existing in the literature is that we add high-order numerical damping terms in the first-order momentequations to control spurious oscillations for the OF-HWENO scheme. The OF-HWENO scheme not only canachieve the designed optimal numerical order, but also can be easily implemented as we use only one set ofstencils in the reconstruction procedure and the same reconstructed polynomials are applied for the zeroth- andfirst-order moment equations. In order to obtain the adaptive order resolution when facing discontinuities, atransition polynomial is added in the reconstruction, where the associated linear weights can also be any positivenumbers as long as their summation equals one. In addition, the OF-HWENO scheme still keeps compactnessas only immediate neighbor values are needed in the space discretization. Some benchmark numerical tests areperformed to illustrate the high-order accuracy, high resolution and robustness of the proposed scheme.

关键词： Hermite WENO scheme hyperbolic conservation laws oscillation-free adaptive order discontinuous Galerkin method

Phosphorylation Promotes the Accumulation of PERIOD Protein Foci

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Research 2024年第1期2023卷 59-69页

作者： Mengna Li Shujing Li Luoying Zhang key laboratory of Molecular Biophysics of Ministry of Education College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanHubei 430074China Department of Life sciences Bengbu Medical CollegeBengbuAnhui 233030China hubei Province key laboratory of Oral and Maxillofacial Development and Regeneration WuhanHubei 430022China

Circadian clock drives the 24-h rhythm in our behavior and *** molecular clock consists of a series of transcriptional/translational feedback loops operated by a number of clock genes.A very recent study reported that the clock protein PERIOD(PER)is organized into discrete foci at the nuclear envelope in fly circadian neurons,which is believed to be important for controlling the subcellular localization of clock *** of inner nuclear membrane protein lamin B receptor(LBR)leads to disruption of these foci,but how they are regulated is yet ***,we found that PER foci are likely phase-separated condensates,the formation of which is mediated by intrinsically disordered region in *** promotes the accumulation of these *** phosphatase 2A,which is known to dephosphorylate PER,hampers the accumulation of the *** the other hand,the circadian kinase DOUBLETIME(DBT)which phosphorylates PER enhances the accumulation of the *** likely facilitates PER foci accumulation by destabilizing the catalytic subunit of protein phosphatase 2A,MICROTUBULE STAR(MTS).In conclusion,here,we demonstrate a key role for phosphorylation in promoting the accumulation of PER foci,while LBR modulates this process by impinging on the circadian phosphatase MTS.

关键词： conclusion separated translational

Endogenous biosynthesis of docosahexaenoic acid(DHA)regulates fish oocyte maturation by promoting pregnenolone production

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Zoological Research 2024年第1期45卷 176-188页

作者： Yi Li Xuehui Li Ding Ye Ru Zhang Chengjie Liu Mudan He Houpeng Wang Wei Hu Yonghua Sun State key laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyInnovation Academy for Seed DesignChinese Academy of SciencesWuhanHubei 430072China College of Advanced Agricultural sciences University of Chinese Academy of SciencesBeijing 100049China hubei Hongshan laboratory WuhanHubei 430070China

Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including ***,the underlying mechanism related to this phenomenon remains largely *** this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and *** show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype *** deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone *** study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during *** turn,the hypothalamic-pituitary-gonadal axis was enhanced by *** conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.

关键词： Docosahexaenoic acid Oocyte maturation Oocyte quality Pregnenolone Microtubule