时变格兰杰因果分析揭示讨价还价游戏中的大脑控制机制

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"该研究揭示了在讨价还价游戏中,大脑的自上而下和自下而上控制机制的不同作用。通过时变Granger因果分析,作者探讨了大脑网络动态特性的影响力,特别是这种特性在功能磁共振成像(fMRI)时间序列数据的有效连接分析中的应用。" 讨价还价游戏是一种复杂的社会交互行为,涉及到决策、情感处理和沟通等多方面的大脑活动。本研究由罗强主导,关注的是大脑在进行此类活动时,从上到下的控制(如高级认知功能的指导)和从下到上的控制(如感官输入的反馈)如何相互作用。这些控制机制的动态变化对理解大脑的工作方式至关重要。 传统的Granger因果分析常用于fMRI数据中探究大脑区域之间的因果关系,但其假设静态的连接模式可能无法充分反映大脑的真实状态。由于大脑神经回路具有生物物理可塑性,其连接性会随时间和环境变化。因此,研究者提出了一种基于信号依赖噪声的新型时变Granger因果分析方法,旨在更准确地捕捉fMRI时间序列数据中的动态信息流。 通过数值模拟和验证,这项新方法展示了如何利用时变特性来改进对大脑有效连接的理解。它能够揭示在讨价还价等社会互动中,大脑区域间信息传递的实时变化,这对于解析复杂社会行为背后的神经机制具有重要意义。 此外,该研究还强调了在分析fMRI数据时考虑时间变异性的重要性。这不仅有助于科学家们更精确地描绘大脑网络的动态图景,而且可能对临床诊断和治疗策略的制定产生积极影响,例如在神经退行性疾病或精神障碍的研究中。 这篇首发论文揭示了在社会交互过程中大脑控制机制的动态性质,并提供了一种新的分析工具,以更好地理解大脑如何在不同情境中调整其功能连接。这一发现对于神经科学、心理学以及相关医学领域都具有深远的影响,为未来的研究提供了新的方向和方法。

Rab GTPases serve as master regulators of membrane trafficking. They can be activated by guanine nucleotide exchange factors (GEF) and be inactivated by GTPase-activating proteins (GAPs). The roles of some GAPs have been explored in Saccharomyces cerevisiae, but are largely unknown in filamentous fungi. Here, we investigated the role of GAP Gyp3 gene, an ortholog of S. cerevisiae Gyp3, in an entomopathogenic fungus, Metarhizium acridum. We found that MaGyp3 is mainly localized to the endoplasmic reticulum (ER) of vegetative hyphae, nuclei of mature conidia, and both ER and nuclei in invasive hyphae. Lack of MaGyp3 caused a decreased tolerance to hyperosmotic stress, heat-shock and UV-B radiation. Moreover, the ΔMaGyp3 mutant showed a significantly decreased pathogenicity owing to delayed germination, reduced appressorium-mediated penetration and impaired invasive growth. Loss of MaGyp3 also caused impaired fungal growth, advanced conidiation and defects in utilization of carbon and nitrogen sources, while overexpression of MaGyp3 exhibited delayed conidiation on nutrient-rich medium and conidiation pattern shift from microcycle conidiation to normal conidiation on nutrient-limited medium. Mavib-1, a tanscription factor invloved in conidiation by affecting nutrient utilizaiton, can directly bind to the promoter of MaGyp3. ΔMaGyp3 and ΔMavib-1 mutants shared similar phenotypes, and overexpression mutants of MaGyp3 and Mavib-1 (Mavib-1-OE) exhibited similar phenotypes in growth, conidiation and pathogenicity. Reintroduction of the Magyp3 driven by strong promoter gpd in ΔMavib-1 mutant recovered the defects in growth and conidiation for dysfunction of Mavib1. Taken together, our findings uncovered the role of GAP3 in a filamentous pathogenic fungus and and illustrated the upstream regulatory mechanism by direct interaction with Mavib-1.请用nature杂志的风格润色成学术论文的形式。

2023-02-10 上传

use java language ,In this project you need to write a book lending system for a Library. The system has different roles for registered users. There are two types of user roles: borrower and lender. Write an IUser interface for library users, with the following UML specification: +----------------------------------+ | <<interface>> | | IUser | +----------------------------------+ | + getName(): String | | + getBook(): int | | + moreBook(int number): void | +----------------------------------+ and a User class that implements IUser and has the following UML specification: +-----------------------------------+ | User | +-----------------------------------+ | - name: String | | - book: int | +-----------------------------------+ | + User(String name, int book) | | + getName(): String | | + getBook(): int | | # setBook(int book): void | | + moreBook(int number): void | | + testUser(): void | +-----------------------------------+ The name instance variable indicates the user name. The book instance variable indicates the number of books borrowed by the user. The setBook method changes the number of books borrowed by the user. The setBook method is protected, not public. This means that only subclasses of the User class can use the setBook method. All the other classes in the system cannot use the setBook method, so they cannot change the number of books borrowed by a user. The purpose of the moreBook method is to increase the number of books borrowed or lent by the user (depending on what kind of user it is) by the number given as argument to the method. The moreBook method of the User class is abstract, since we do not know what kind of role the user is (a borrower borrows books from other users and a lender lend books to other users). Also add to your program a Test class to test your User class. public class Test { public static void main(String[] args) { User.testUser(); } }

2023-05-25 上传