Adaptive networks

  • 文章类型: Journal Article
    这里,我们提出了自适应合作网络的有效应用,即在大流行或紧急情况下协助残疾人在人群中导航。为了实现这一点,我们对人群运动进行建模,并引入合作学习方法,使健康受损或坐在轮椅上的人群成员能够合作和自我组织,以确保他们在人群中的安全运动。这里,假设每个agent可以估计其他人群成员的移动路径和变化位置。因此,网络节点(代理)应该通过改变它们之间的速度和距离来不断地重组自己,从周围的墙壁,以及在预定义范围内的障碍物。还演示了如何将诸如AirTags之类的可用无线跟踪器用于此目的。针对环境参数的实时变化检查了模型的有效性,并验证了其有效性。
    Here, we present an effective application of adaptive cooperative networks, namely assisting disables in navigating in a crowd in a pandemic or emergency situation. To achieve this, we model crowd movement and introduce a cooperative learning approach to enable cooperation and self-organization of the crowd members with impaired health or on wheelchairs to ensure their safe movement in the crowd. Here, it is assumed that the movement path and the varying locations of the other crowd members can be estimated by each agent. Therefore, the network nodes (agents) should continuously reorganize themselves by varying their speeds and distances from each other, from the surrounding walls, and from obstacles within a predefined limit. It is also demonstrated how the available wireless trackers such as AirTags can be used for this purpose. The model effectiveness is examined with respect to the real-time changes in environmental parameters and its efficacy is verified.
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  • 文章类型: Journal Article
    自适应交互是许多实词网络系统的重要属性。这种网络的一个特征是其连通性的变化取决于交互元件的当前状态。在这项工作中,我们研究了自适应耦合的异构特性如何影响网络集体行为中新场景的出现的问题。在耦合相位振荡器的双种群网络的框架内,我们分析了异质相互作用的各种因素的作用,如耦合适应的规则和它们的变化率在网络的各种类型的相干行为的形成。我们证明了各种异构自适应方案会导致形成各种类型的瞬态相位簇。
    Adaptive interactions are an important property of many real-word network systems. A feature of such networks is the change in their connectivity depending on the current states of the interacting elements. In this work, we study the question of how the heterogeneous character of adaptive couplings influences the emergence of new scenarios in the collective behavior of networks. Within the framework of a two-population network of coupled phase oscillators, we analyze the role of various factors of heterogeneous interaction, such as the rules of coupling adaptation and the rate of their change in the formation of various types of coherent behavior of the network. We show that various schemes of heterogeneous adaptation lead to the formation of transient phase clusters of various types.
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  • 文章类型: Journal Article
    疾病传播与个人风险感知之间的相互作用对于模拟传染病的传播至关重要。我们提出了一个常微分方程(ODE)的平面系统,以描述个人接触网络中的传播现象和平均链接密度的共同演化。与标准流行病模型相反,我们假设接触网络根据当前人群中疾病的患病率而变化,即网络适应当前的流行状态。我们假设使用两种功能响应来描述个人风险感知:一种用于链接中断,一种用于链接创建。重点是将该模型应用于流行病,但我们也强调了其他可能的应用领域。我们推导了基本复制数的显式形式,并保证至少存在一个地方性均衡,所有可能的功能性反应。此外,我们表明,对于所有功能响应,极限循环不存在。这意味着我们的最小模型无法重现随之而来的流行病浪潮,需要更复杂的疾病或行为动力学来重现流行病。
    The interplay between disease spreading and personal risk perception is of key importance for modelling the spread of infectious diseases. We propose a planar system of ordinary differential equations (ODEs) to describe the co-evolution of a spreading phenomenon and the average link density in the personal contact network. Contrary to standard epidemic models, we assume that the contact network changes based on the current prevalence of the disease in the population, i.e. the network adapts to the current state of the epidemic. We assume that personal risk perception is described using two functional responses: one for link-breaking and one for link-creation. The focus is on applying the model to epidemics, but we also highlight other possible fields of application. We derive an explicit form for the basic reproduction number and guarantee the existence of at least one endemic equilibrium, for all possible functional responses. Moreover, we show that for all functional responses, limit cycles do not exist. This means that our minimal model is not able to reproduce consequent waves of an epidemic, and more complex disease or behavioural dynamics are required to reproduce epidemic waves.
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  • 文章类型: Journal Article
    在这项工作中,我们提出了一个关于脓毒症及其器官损害后果建模的动力系统观点。我们基于实质细胞和免疫细胞通过细胞因子的相互作用,开发了脓毒症的功能性两层网络模型。和实质的共进化动力学,免疫细胞,和细胞因子。通过两层系统中相位振荡器的简单范式模型,我们分析了免疫系统失调和实质之间的器官威胁相互作用的出现。我们证明,在生理或病理情况下,薄壁组织和基质(免疫层)之间的复杂细胞合作可能与网络的动态模式有关。通过这种方式,我们通过健康体内平衡状态(频率同步)的失调来解释败血症,从而导致实质中的病理状态(去同步或多频率簇)。通过确定关键的相互作用参数,我们可以深入了解薄壁组织和基质的复杂稳定和不稳定相互作用。实质细胞(代谢)和非特异性免疫细胞(先天免疫系统的反应)的耦合动力学由双链层的节点表示。细胞因子相互作用通过代表免疫细胞(具有快速适应时间尺度)和实质细胞(缓慢适应时间尺度)的节点之间的自适应耦合权重来建模。以及双链网络中的实质和免疫细胞对之间(固定双向耦合)。所提出的模型可以对败血症中的器官功能障碍进行功能描述,并在合理的病理生理背景下对复发风险进行描述。
    In this work, we propose a dynamical systems perspective on the modeling of sepsis and its organ-damaging consequences. We develop a functional two-layer network model for sepsis based upon the interaction of parenchymal cells and immune cells via cytokines, and the coevolutionary dynamics of parenchymal, immune cells, and cytokines. By means of the simple paradigmatic model of phase oscillators in a two-layer system, we analyze the emergence of organ threatening interactions between the dysregulated immune system and the parenchyma. We demonstrate that the complex cellular cooperation between parenchyma and stroma (immune layer) either in the physiological or in the pathological case can be related to dynamical patterns of the network. In this way we explain sepsis by the dysregulation of the healthy homeostatic state (frequency synchronized) leading to a pathological state (desynchronized or multifrequency cluster) in the parenchyma. We provide insight into the complex stabilizing and destabilizing interplay of parenchyma and stroma by determining critical interaction parameters. The coupled dynamics of parenchymal cells (metabolism) and nonspecific immune cells (response of the innate immune system) is represented by nodes of a duplex layer. Cytokine interaction is modeled by adaptive coupling weights between nodes representing immune cells (with fast adaptation timescale) and parenchymal cells (slow adaptation timescale), and between pairs of parenchymal and immune cells in the duplex network (fixed bidirectional coupling). The proposed model allows for a functional description of organ dysfunction in sepsis and the recurrence risk in a plausible pathophysiological context.
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  • 文章类型: Editorial
    暂无摘要。
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  • 文章类型: Journal Article
    在这项研究中,我们为肿瘤或感染引起的病理状态的建模提供了动态系统的观点。以先天免疫系统为参照点,建立统一的疾病模型。我们基于实质细胞和免疫细胞通过细胞因子的相互作用,提出了一个用于癌变和败血症的两层网络模型。和实质的共同进化动力学,免疫细胞,和细胞因子。我们的目的是表明,在生理和病理情况下,薄壁组织和基质(免疫层)之间的复杂细胞合作可以通过简单的相位振荡器模型在质量和功能上进行描述。通过这个,我们解释致癌作用,肿瘤进展,和败血症通过健康体内平衡状态的不稳定(频率同步),和出现病理状态(去同步或多频率簇)。实质细胞(代谢)和非特异性免疫细胞(先天免疫系统的反应)的耦合动力学由双链层的节点表示。细胞因子相互作用通过表示免疫细胞(具有快速适应时间尺度)和实质细胞(缓慢适应时间尺度)的节点之间以及双链网络中的实质细胞和免疫细胞对之间的自适应耦合权重(固定双向耦合)来建模。因此,致癌作用,脓毒症的器官功能障碍,复发风险可以在正确的功能背景下描述。
    In this study, we provide a dynamical systems perspective to the modelling of pathological states induced by tumors or infection. A unified disease model is established using the innate immune system as the reference point. We propose a two-layer network model for carcinogenesis and sepsis based upon the interaction of parenchymal cells and immune cells via cytokines, and the co-evolutionary dynamics of parenchymal, immune cells, and cytokines. Our aim is to show that the complex cellular cooperation between parenchyma and stroma (immune layer) in the physiological and pathological case can be qualitatively and functionally described by a simple paradigmatic model of phase oscillators. By this, we explain carcinogenesis, tumor progression, and sepsis by destabilization of the healthy homeostatic state (frequency synchronized), and emergence of a pathological state (desynchronized or multifrequency cluster). The coupled dynamics of parenchymal cells (metabolism) and nonspecific immune cells (reaction of innate immune system) are represented by nodes of a duplex layer. The cytokine interaction is modeled by adaptive coupling weights between the nodes representing the immune cells (with fast adaptation time scale) and the parenchymal cells (slow adaptation time scale) and between the pairs of parenchymal and immune cells in the duplex network (fixed bidirectional coupling). Thereby, carcinogenesis, organ dysfunction in sepsis, and recurrence risk can be described in a correct functional context.
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  • 文章类型: Journal Article
    The concept of memory is traditionally associated with organisms possessing a nervous system. However, even very simple organisms store information about past experiences to thrive in a complex environment-successfully exploiting nutrient sources, avoiding danger, and warding off predators. How can simple organisms encode information about their environment? We here follow how the giant unicellular slime mold Physarum polycephalum responds to a nutrient source. We find that the network-like body plan of the organism itself serves to encode the location of a nutrient source. The organism entirely consists of interlaced tubes of varying diameters. Now, we observe that these tubes grow and shrink in diameter in response to a nutrient source, thereby imprinting the nutrient\'s location in the tube diameter hierarchy. Combining theoretical model and experimental data, we reveal how memory is encoded: a nutrient source locally releases a softening agent that gets transported by the cytoplasmic flows within the tubular network. Tubes receiving a lot of softening agent grow in diameter at the expense of other tubes shrinking. Thereby, the tubes\' capacities for flow-based transport get permanently upgraded toward the nutrient location, redirecting future decisions and migration. This demonstrates that nutrient location is stored in and retrieved from the networks\' tube diameter hierarchy. Our findings explain how network-forming organisms like slime molds and fungi thrive in complex environments. We here identify a flow networks\' version of associative memory-very likely of relevance for the plethora of living flow networks as well as for bioinspired design.
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  • 文章类型: Journal Article
    环状低硫族化合物(COC)正在成为渗透细胞的有希望的系统。明显优于和不同于所报道的二硒二烷和表硫二酮哌嗪,我们介绍了苯并多硫酸盐(BPS),这显示了高效的交付,对细胞内吞抑制剂不敏感,以及与蛋白质一样大的底物的兼容性。这种高活性与高反应性相吻合,选择性地朝向硫醇,在紧张的情况下超过二硫化物的汇率。结果是极端硫物种的动态共价网络,包括环状低聚物,从二聚体到七聚体,环中最多有19个硫。从该展开的自适应网络中进行选择,然后产生访问新摄取途径所需的反应性和选择性。与其他COCs相反,BPS在硫醇亲和柱上显示高保留。细胞穿透的新模式的识别是重要的,因为他们承诺新的解决方案,在交付和超越挑战。
    Cyclic oligochalcogenides (COCs) are emerging as promising systems to penetrate cells. Clearly better than and different to the reported diselenolanes and epidithiodiketopiperazines, we introduce the benzopolysulfanes (BPS), which show efficient delivery, insensitivity to inhibitors of endocytosis, and compatibility with substrates as large as proteins. This high activity coincides with high reactivity, selectively toward thiols, exceeding exchange rates of disulfides under tension. The result is a dynamic-covalent network of extreme sulfur species, including cyclic oligomers, from dimers to heptamers, with up to nineteen sulfurs in the ring. Selection from this unfolding adaptive network then yields the reactivities and selectivities needed to access new uptake pathways. Contrary to other COCs, BPS show high retention on thiol affinity columns. The identification of new modes of cell penetration is important because they promise new solutions to challenges in delivery and beyond.
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  • 文章类型: Journal Article
    We study a model for switching strategies in the Prisoner\'s Dilemma game on adaptive networks of player pairings that coevolve as players attempt to maximize their return. We use a node-based strategy model wherein each player follows one strategy at a time (cooperate or defect) across all of its neighbors, changing that strategy and possibly changing partners in response to local changes in the network of player pairing and in the strategies used by connected partners. We compare and contrast numerical simulations with existing pair approximation differential equations for describing this system, as well as more accurate equations developed here using the framework of approximate master equations. We explore the parameter space of the model, demonstrating the relatively high accuracy of the approximate master equations for describing the system observations made from simulations. We study two variations of this partner-switching model to investigate the system evolution, predict stationary states, and compare the total utilities and other qualitative differences between these two model variants.
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  • 文章类型: Journal Article
    Early warning signals of sudden regime shifts are a widely studied phenomenon for their ability to quantify a system\'s proximity to a tipping point to a new and contrasting dynamical regime. However, this effect has been little studied in the context of the complex interactions between disease dynamics and vaccinating behaviour. Our objective was to determine whether critical slowing down (CSD) occurs in a multiplex network that captures opinion propagation on one network layer and disease spread on a second network layer. We parameterized a network simulation model to represent a hypothetical self-limiting, acute, vaccine-preventable infection with short-lived natural immunity. We tested five different network types: random, lattice, small-world, scale-free, and an empirically derived network. For the first four network types, the model exhibits a regime shift as perceived vaccine risk moves beyond a tipping point from full vaccine acceptance and disease elimination to full vaccine refusal and disease endemicity. This regime shift is preceded by an increase in the spatial correlation in non-vaccinator opinions beginning well before the bifurcation point, indicating CSD. The early warning signals occur across a wide range of parameter values. However, the more gradual transition exhibited in the empirically-derived network underscores the need for further research before it can be determined whether trends in spatial correlation in real-world social networks represent critical slowing down. The potential upside of having this monitoring ability suggests that this is a worthwhile area for further research.
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