Experimental Study of Adaptation to the Edge of Chaos and Critical Scaling in the Self-adjusting Peroxidase-Oxidase Reaction

自调节过氧化物酶-氧化酶反应中适应混沌边缘和临界尺度的实验研究

• 批准号: 0140179
• 负责人: Alfred Hubler
• 金额: $ 16.79万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140179&HistoricalAwards=false
• 关键词: Experimental; Study; Adaptation; Edge; Chaos

0140179Hubler One aspect of biocomplexity is the ability of biota to self-adjust to theirenvironment. Previous studies of adaptive behavior have shown thatadaptive systems will evolve over time to states that are weakly chaotic, acondition known as the edge of chaos. These studies typically use agenetic algorithm (computer-based evolution) to implement adaptation. Itis conjectured that most self-adjusting dynamical systems that initiallyhave chaotic behavior will also adapt toward the edge of chaos. A modelfor self-adjusting dynamical systems is introduced which treats the controlparameters as slowly varying, rather than constant. The dynamics of theseparameters is assumed to be governed by some low-pass filtered feedbackfrom the dynamical variables of the system. Under the influence of noise,at least in numerical models, the probability of chaotic breakout shows auniversal scaling with the duration of the breakouts.Applications of the model to biochemical oscillators as the simplestpossible adaptive system relevent to environmental dynamics will beinvestigated. A high degree of interdisciplinarity is required, as theresearch involves expertise in dynamical systems, plant biology,instrumental measurements, cybernetics, enzymology, chemistry, and physics. The system is chosen to be "biocomplex," yet simple enough that meaningfulmeasurements can be made and quantitative models can be evaluated.We intend to experimentally demonstrate adaptation using theperoxidase-oxidase oscillator as an example. This system is known toexhibit non-linear, complex, and even chaotic behavior. We will explore ifthe in situ behavior of this enzyme provides the first experimentalevidence for adaptation to the edge of chaos in a naturally occurringsystem. Detailed chemical models are available to guide our experiments.We will experimentally implement low-pass filtered feedback from thedynamical variables to the control parameters through:1. a computer based probe-actuator system, and 2. the comparatively slow response of the metabolism of a thin section of horseradish root tissues suspended in a reactor, and check for adaptation to the edge of chaos, and critical scaling of chaotic outbreaks of chemical oscillations.Outreach activities to local secondary schools will be incorporated intoour existing collaborations with high school science teachers. If ourinitial experiments on plant peroxidases show the anticipated complexity,we will then explore the related complexity in the behavior of peroxidasesand oxidases in human neutrophils, cells associated with anti-bacterialactivity and response to systemic afronts.

0140179 HUBLER生物复杂性的一个方面是生物群体自我调整对环境的能力。 先前对适应性行为的研究表明，自适应系统会随着时间的流逝而演变为弱混乱的，被称为混乱边缘的州。 这些研究通常使用赋予算法（基于计算机的进化）来实施适应。 ITI猜想，最初使混乱行为最初的自我调整动力系统也将适应混乱的边缘。 引入了Modelfor自调整的动力学系统，该系统将控制参数视为缓慢变化而不是恒定。 假定theeparameters的动力学由系统的动态变量进行一些低通滤波的反馈来控制。 在噪声的影响下，至少在数值模型中，混沌突破的概率显示了临时尺度随临时的持续时间。对生物化学振荡器的应用程序将与环境动力学相关的简单可靠的适应系统，将被访问。 需要高度的跨学科性，因为搜索涉及动态系统，植物生物学，工具测量，控制论，酶学，化学和物理学方面的专业知识。选择该系统是“生物复合物”，但很简单，可以进行有意义的测量，并可以评估定量模型。我们打算使用percoxidase-氧化酶 - 氧化酶振荡剂作为示例来实验证明适应性。 该系统已知可以证明非线性，复杂甚至混乱的行为。 我们将探讨该酶的原位行为是否为适应自然出现的系统中的混乱边缘提供了第一个实验策略。 详细的化学模型可用于指导我们的实验。我们将通过以下方式实验实验，从THEDENANICAL变量到控制参数的低通滤波反馈：1。一个基于计算机的探针传动系统和2。悬挂在反应堆中的辣根根组织的代谢反应相对较慢，并检查适应混乱的边缘，而对中学振荡的混乱局面的关键缩放将与中学的合作融合到现有的中学科学教师中。 如果我们对植物过氧化物酶进行的我们的初始实验表明了预期的复杂性，我们将探讨过氧化物酶和氧化酶在人类嗜中性粒细胞中的行为中的相关复杂性，与抗细菌性的细胞和对系统性AFRONT的反应相关的细胞。