一个具有扩散和时滞的捕食模型的持久性与周期解的存在性

对一类在斑块环境下具有Beddington型功能性反应和时滞现象的非自治捕食系统进行了研究,证明系统在适当的条件下是永久持续生存的;利用重合度理论,得到了一组保证该系统存在正周期解的充分条件．     

具有脉冲效应的时滞捕食系统的正周期解

提出了一个具有脉冲效应的周期时滞捕食系统,运用叠合的方法研究了该系统的周期解的存在性．结论表明在一定的条件下捕食者和食饵周期变化．     

基于比率的三种群捕食系统的持续生存

研究一类具有时滞和基于比率的三种群捕食系统,证明该系统在一定条件下是持续生存的;给出无时滞情况下非零平均点的稳定性的充分条件。     

正弦调制光诱发脑电响应特性的研究

本文介绍了我们研制的正弦调制光诱发脑电系统,该系统由多功能刺激控制器、换能器、脑电信号的采集放大、系统控制部份组成,具有智能化、微机化的特点.我们应用该系统进行了人脑在正弦调制光刺激下诱发电位响应特性的研究,实验结果进行了处理和分析.     

具有时滞的一捕食者-两食饵比率型生态系统的持久性与稳定性

研究一个具有时滞的一捕食者－两食饵比率型生态系统,证明了该系统在适当条件下的一致持久性。通过构造Lyapunov泛函,得到了该系统正平衡点局部渐近稳定的充分条件。     

基于遥感数据源的景观分析系统的设计与实现

在Ｖｉｓｕａｌ Ｃ＋＋环境下,设计并实现了一个景观分析系统。该系统采用提取斑块边界象素集的方法,提高了斑块搜索的速度,而且提供了斑块间距离计算、相邻斑块间边界长度计算等景观分析功能。该系统被应用到北京西北郊同分析中。通过分析表明,该系统不仅能计算面积、周长、中心坐标和最近同类型斑块的距离等单个斑块指数,而且能在此基础上计算景观类型和整个景观层次上的各种指数,从而弥补了目前多数地理信息系统在分析应用     

带存放率的周期竞争扩散系统的稳定共存

应用上、下解方法和抛物型方程的极值原理,研究了带存放率的周期竞争系统ut-D1Δu=u（α-bu-cv）＋h,vt-D2Δv=v）d-eu-fv）＋k 在齐次Neumann边界条件下解的渐近性态,得到了该系统的全局渐近性．     

一类非自治捕食-被捕食系统的全局渐近稳定性

本文研究了一类非自治捕食-被捕食的周期系统．当周期为ω＞0时,在某些条件下证明了该系统正周期解的存在唯一性和全局渐近稳定性．     

Fitz-Hugh Nagumo系统的渐近稳定性

用无穷维动力系统的方法研究了Fitz-Hugh Nagumo神经系统中沿神经细胞轴突信号传递的长时间行为.在齐次边界条件与非齐次边界条件下证明了系统在其不变流形上的全局吸引子为系统在该不变流形内的唯一平衡点,从而证明了该系统的渐近稳定性.     

具有时滞和反馈控制的Logistic增长模型的正周期解

首次研究同时具有状态依赖时滞和连续时滞的反馈控制Logistic增长模型,利用重合度理论研究其正周期解的存在性问题,得到了该系统周期正解存在的充分性条件,同时通过构造适当地Lyapunov泛函得到保证该系统（在适当限制下）存在全局稳定周期解的充分性条件,得到一些新结果,所得结果推广和改进了相关文献的主要结果。     

A two-stage minibioreactor system for continuous toxicity monitoring.

A two-stage minibioreactor system was successfully developed for continuous toxicity monitoring. This system consists of two minibioreactors in series. Recombinant Escherichia coli DPD2794 containing a RecA::luxCDABE fusion as a model strain was utilized to monitor environmental insults to DNA, with mitomycin C as a model toxicant. Pulse type exposures were used to evaluate the system's reproducibility and reliability. Step inputs of mitomycin C have been adopted to show the system's stability. The system's ability to monitor the possible upsets or accidental discharges of toxic chemicals was also evaluated with these step insults. All the data demonstrated that this two-stage minibioreactor system using recombinant bacteria containing stress promoters fused with lux genes is quite appropriate for continuous toxicity monitoring. Long-term operation and minimized media-usage have been investigated. Thus application to many different areas, including an early warning system of wastewater biotreatment plant upsets and the monitoring and tracking of accidental spills, discharges or failures in plant operation are plausible.     

Analysing hierarchy in the organization of biological and physical systems

A structured approach is discussed for analysing hierarchy in the organization of biological and physical systems. The need for a structured approach follows from the observation that many hierarchies in the literature apply conflicting hierarchy rules and include ill-defined systems. As an alternative, we suggest a framework that is based on the following analytical steps: determination of the succession stage of the universe, identification of a specific system as part of the universe, specification of external influences on a system's creation and analysis of a system's internal organization. At the end, the paper discusses practical implications of the proposed method for the analysis of system organization and hierarchy in biology, ecology and physics.     

Biochemical oscillations and the development of organization

Systems of linear inhomogeneous rate equations for reaction-diffusion kinetics are solved utilizing a Green's integral operator technique. The general theory for the eigenvalues and eigenfunctions of n-component linear systems undergoing diffusion and reaction is derived. The time development of temporal oscillations of the system's reactants is studied. Systemic homogeneity is related to a quantity defined as redundancy. The latter is a function of the system's entropy and a correlation is made between redundancy and noise. It is hypothesized that this correlation may provide a tie between the time development of noise and the time development of pathology in living systems.     

Versatility in computer automation for biofeedback: the behavioral assessment and rehabilitative training system (BARTS)

User versatility in a system for computer-automated biofeedback training is the degree to which the assessment and training parameters may be altered by the user's employing English language or other simple code, that is, without altering the system's applications software. The Behavioral Assessment and Rehabilitative Training System (BARTS) includes a design and control program that allows for the specification of assessment and training protocols by persons who are entirely lacking in computer programming skills. This paper describes the logic for data acquisition and training that is incorporated in the BARTS, describes the parameters that must be specified in constituting unique assessment or training protocols, and illustrates the system's application in a research-oriented biofeedback clinic.     

价格成本变化的具有Smith增长和崔-L增长的生物种群的经济捕获模型

主要研究了具有Smith增长曲线和崔-L增长曲线的两类生物种群模型。建立了价格成本变化的数学生物经济捕获模型,讨论了模型的定性性质,证明了平衡解的存在性及其稳定性．     

A matter of life and death

Our ability to sustain some of the outward signs of life has rendered obsolete the legal system's definition of what it means to be alive.     

一类生物系统平衡点的稳定性

本文利用Logistic模型和稳定性理论,建立了一类生物系统竞争和排斥的数学模型,并且讨论了模型平衡点稳定的条件。     

SPICE: discovery of phenotype-determining component interplays

ABSTRACT: BACKGROUND: A latent behavior of a biological cell is complex. Deriving the underlying simplicity, or the fundamental rules governing this behavior has been the Holy Grail of systems biology. Data-driven prediction of the system components and their component interplays that are responsible for the target system's phenotype is a key and challenging step in this endeavor. RESULTS: The proposed approach, which we call System Phenotype-related Interplaying Components Enumerator (SPICE), iteratively enumerates statistically significant that are hypothesized (1) to play an important role in defining the specificity of the target system's phenotype(s); (2) to exhibit a functionally coherent behavior, namely, act in a coordinated manner to perform the phenotype-specific function; and (3) to improve the predictive skill of the system's phenotype(s) when used collectively in the ensemble of predictive models. When validated, SPICE effectively identified system components related to three target phenotypes: biohydrogen production, motility, and cancer. Manual results curation agreed with the known phenotype-related system components reported in literature. Additionally, using the identified system components as discriminatory features improved the prediction accuracy by 10% on the phenotype-classification task when compared to a number of state-of-the-art methods applied to eight benchmark microarray data sets. CONCLUSION: Conclusion: We formulate a problem--- enumeration of phenotype-determining system component interplays---and propose an effective methodology (SPICE) to address this problem. SPICE improved identification of cancer-related groups of genes from various microarray data sets and detected groups of genes associated with microbial biohydrogen production and motility, many of which were reported in literature. SPICE also improved the predictive skill of the system's phenotype determination compared to individual classifiers and/or other ensemble methods, such as bagging, boosting, random forest, nearest shrunken centroid, and random forest variable selection method. All the supporting data and software can be found in the supplemental files.     

Versatility in computer automation for biofeedback: The Behavioral Assessment and Rehabilitative Training System (BARTS)

User versatility in a system for computer-automated biofeedback training is the degree to which the assessment and training parameters may be altered by the user's employing English language or other simple code, that is, without altering the system's applications software. The Behavioral Assessment and Rehabilitative Training System (BARTS) includes a design and control program that allows for the specification of assessment and training protocols by persons who are entirely lacking in computer programming skills. This paper describes the logic for data acquisition and training that is incorporated in the BARTS, describes the parameters that must be specified in constituting unique assessment or training protocols, and illustrates the system's application in a research-oriented biofeedback clinic.This work was supported by NINCDS Grant 1 R01 N 15796 (C. S. Cleeland and G. K. Montgomery), and by a grant from the Charles E. Culpepper Foundation, Inc., New York.