679 research outputs found

    Quantum Annealing Based Difficulty Adjustable Maze Generation

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    In this paper, the maze generation using quantum annealing is proposed. We reformulate a standard algorithm to generate a maze into a specific form of a quadratic unconstrained binary optimization problem suitable for the input of the quantum annealer. To generate more difficult mazes, we introduce an additional cost function QupdateQ_{update} to increase the difficulty. The difficulty is evaluated by the time to solve the maze. To check the efficiency of our scheme to create the maze, we investigated the time-to-solution of a quantum processing unit, classical computer, and hybrid solver.Comment: 14pages, 12figure

    Isolation of a Mutant ofArabidopsis thalianaCarrying Two Simultaneous Mutations Affecting Tobacco Mosaic Virus Multiplication within a Single Cell

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    AbstractTobacco mosaic virus strain Cg (TMV-Cg) infectsA. thalianasystemically. In order to identify host factors involved in the multiplication of TMV-Cg, we isolated a mutant ofA. thalianafrom an M2 population mutagenized by fast neutron irradiation, in which the accumulation of the coat protein in upper systemic leaves was reduced to low levels. The phenotype of the mutant, YS241, was controlled primarily by a single nuclear recessive mutation namedtom2-1,which was distinct fromtom1, a separate mutation which also affects TMV-Cg multiplication. Thetom2-1mutation affected the accumulation of TMV-related RNAs in protoplasts in a tobamovirus-specific manner, suggesting that the wild-typeTOM2gene product is necessary for efficient amplification of TMV-related RNAs within a single cell, through specific interaction with virus-coded factors. Furthermore, we found that YS241 contained a single dominant modifier namedttm1,which increased the efficiency of multiplication of TMV-Cg and a tomato strain of TMV in atom2-1genetic background, both in plants and in protoplasts. We propose that thettm1element might be a translocated form of theTOM2gene

    Interconversion of Two GDP-Bound Conformations and Their Selection in an Arf-Family Small G Protein

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    SummaryADP-ribosylation factor (Arf) and other Arf-family small G proteins participate in many cellular functions via their characteristic GTP/GDP conformational cycles, during which a nucleotide∗Mg2+-binding site communicates with a remote N-terminal helix. However, the conformational interplay between the nucleotides, the helix, the protein core, and Mg2+ has not been fully delineated. Herein, we report a study of the dynamics of an Arf-family protein, Arl8, under various conditions by means of NMR relaxation spectroscopy. The data indicated that, when GDP is bound, the protein core, which does not include the N-terminal helix, reversibly transition between an Arf-family GDP form and another conformation that resembles the Arf-family GTP form. Additionally, we found that the N-terminal helix and Mg2+, respectively, stabilize the aforementioned former and latter conformations in a population-shift manner. Given the dynamics of the conformational changes, we can describe the Arl8 GTP/GDP cycle in terms of an energy diagram

    Efficacy of Bidens pilosa Extract against Herpes Simplex Virus Infection In Vitro and In Vivo

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    The development of strains of herpes simplex virus (HSV) resistant to drugs has been reported among the immunocompromised patients. Thus, there is a need to develop new therapeutic agents for HSV infections. We evaluated the anti-HSV activity of Bidens pilosa (B. pilosa), a tropical weed, in tissue culture cells and a mouse model. B. pilosa extract showed potent virucidal activity. It inhibited plaque formation and suppressed virus yield in Vero and RAW 264.7 cells infected with HSV-1 and HSV-2. Both the binding of virus to host cells and penetration of virus into cells were also blocked by B. pilosa. Furthermore, B. pilosa was effective against thymidine kinase-deficient and phosphonoacetate-resistant HSV-1 strains. B. pilosa treatment increased the survival rate of HSV-infected mice and limited the development of skin lesions. Our results indicate that B. pilosa has anti-HSV activity and is thus a potentially useful medical plant for treatment of HSV infection

    Multi-Objective Bayesian Optimization with Active Preference Learning

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    There are a lot of real-world black-box optimization problems that need to optimize multiple criteria simultaneously. However, in a multi-objective optimization (MOO) problem, identifying the whole Pareto front requires the prohibitive search cost, while in many practical scenarios, the decision maker (DM) only needs a specific solution among the set of the Pareto optimal solutions. We propose a Bayesian optimization (BO) approach to identifying the most preferred solution in the MOO with expensive objective functions, in which a Bayesian preference model of the DM is adaptively estimated by an interactive manner based on the two types of supervisions called the pairwise preference and improvement request. To explore the most preferred solution, we define an acquisition function in which the uncertainty both in the objective functions and the DM preference is incorporated. Further, to minimize the interaction cost with the DM, we also propose an active learning strategy for the preference estimation. We empirically demonstrate the effectiveness of our proposed method through the benchmark function optimization and the hyper-parameter optimization problems for machine learning models
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