Biological Control Systems Research Articles

Integral World Economic Structure and Global Security — Key Problems of Modern Science

Aim. To identify the key problems of the formation of the Integral world economic order in the context of mastering the achievements of the sixth technological order and regulating global security.Tasks. To identify the theoretical status of the Integral world economic order, the prospects for Russia to enter its rhythm of development and its inherent architectonics of global security.Methods. Based on the calculated data of economic statistics, their theoretical understanding, a conceptual apparatus for studying the relationship between technological and world economic processes with the monitoring of global risks has been formed.Results. The main characteristics of states corresponding to the Integral world economic order have been identified. An assessment of the dynamics of its development and the strategy of advanced development has been given. The need to include in the new scientific and technological picture of the world the ideas about the fundamental belonging of any complex systems of functions and structures that ensure not only their self-development, stability and reliability, but also ideas about the security of their existence, development and functioning has been substantiated.Conclusions. The system of global and Eurasian security should be considered as an integral part of the international architecture of the Integral WES and its basis. Global — because it involves the creation of mechanisms that prevent the widespread spread of the “octopus” of hybrid war, and Eurasian — because the core of the Integral WES is being formed in the space of Greater Eurasia, or more precisely, in its eastern part. The Integral WES should be considered not only as a prototype of the polycentric world order, which was discussed above, but also as the created architectonics of its global security. In the new scientific and technological picture of the world, ideas are being formed about the fundamental belonging of any complexly organized systems of functions and structures that ensure not only their self-development, stability and reliability, but also ideas about the security of their existence, development and functioning. Thus, we inevitably approach the need to develop asfatronics as a theory of global security. The object of asfatronics is safety, defined in the ultimate sense as the absence of danger, unacceptable risk, and the subject is energy-information processes of safety, covering all levels of organization of biological, social and technical control systems (from nano- to macrolevel). The field of research of asfatronics is ecological, military, geopolitical, technogenic, economic, social, information-psychological, cognitive and other types of safety. Global safety should be considered not limited to environmental issues and international relations. It covers the whole variety of functions and structures of self-development, sustainability, reliability, safety of existence of bio-, socio-, cogno- and technosphere. In the context of the problems considered above, the structural sections of asfatronics should be global safety, ensuring the prevention of geopolitical, ecological, economic, social and technological risks arising in the process of formation of the Integral world economic structure based on nano-, bio-, info-, cogno- and social technologies.

Collective oscillatory signaling in Dictyosteliumdiscoideum acts as a developmental timer initiated by weak coupling of a noisy pulsatile signal.

Oscillatory phenomena play widespread roles in the control of biological systems. In D.discoideum, oscillatory cyclic adenosine monophosphate (cAMP) signaling drives collective behavior and induces a temporal developmental gene expression program. How collective cAMP oscillations emerge or how they encode temporal transcriptional information is still poorly understood. To address this, we identified a transcription factor required for the initiation of collective behavior. Hbx5 activity is cAMP dependent and provides a sensitive single-cell readout for cAMP signaling. Extensive stochastic pulsatile cAMP signaling is found to precede collective oscillations. Stochastic signaling induces Hbx5-dependent transcriptional feedback, which enhances signal sensitivity and cell-cell coupling. This results in the emergence of synchronized collective oscillations, which subsequently activates the GtaC transcription factor and triggers shifts in developmental gene expression. Our results suggest this temporal coordination is encoded by changes in the amplitude of cAMP oscillations and differential sensitivity of these transcription factors to the cAMP-regulated kinase ErkB.

EVALUATION OF THE EFFECTIVENESS OF BIOLOGICAL PREPARATIONS FOR THE PROTECTION OF TOMATOES FROM LATE BLIGHT IN PROTECTED GROUND UNDER DRIP IRRIGATION

The article is devoted to the study of the peculiarities of biological protection of tomatoes against late blight in protected ground. The article summarises the peculiarities of the phytopathogenic situation in tomato agrocenoses in greenhouses under artificial climate control. A brief literature review was conducted from the point of view of modern strategies for controlling late blight in closed, artificially regulated tomato agrocenoses. The level of damage caused by late blight over a multi-year period was assessed from the point of view of both the reduction of tomato yields and pathogen resistance to new active substances and their combination. In the course of the study, the variants of application of classical fungicides in the composition of modern active substances (Kurzat M 68% wdg, 0,2–0,3 g/m2; Zorvek Incantia, 33% s.e. – 0,05 ml/m2; Banjo Forte KS, 0,1 ml/m2) with the use in the phenological stage period from intensive branching to fruit formation (VVSN 42-73), as well as the option of single sequential application of recommended biological products of fungicidal nature (Trichodermin (VIRIDIN), 20 g, 20 g/5 l of water/1 hundred square metres; Phytocide-p, 5 ml / 5 l of water / 1 hectare; Biological fungicide for tomatoes Effect, 5 g / 5 l of water / 1 hectare) and the option of their maximum combination in the same phenological period as the use of classical fungicides. It was found that the degree of damage to the bush by late blight (Ph. infestans de Bary) during the period of research in the farm conditions was noticeable (8,3%) and medium (12,7%) according to the standard scale of accounting. It has been determined that the system of purely biological variant with a single use of alternative fungicides is inferior to the variant of using the classical line of fungicides available on the Ukrainian market - on average, during the research period, the effectiveness of the classical scheme of fungicide application against tomato late blight at the enterprise was 86.45%, and the alternative biological –76.80%, which is 9.65% lower. For the variant with the intensification of the use of biological protection preparations against late blight, the average protection efficiency for two years of research was up to 85,1%. It was proved that the economic efficiency of the variant of classical pesticides application was maximum and provided an increase in tomato yield to the control on average at the level of 6,2 kg/m2 during the research period. Of the variants of biological protection systems, the most effective was the variant of combined use of biological preparations of fungicidal nature at the level of 5,5 kg/m2. It has been established that the variants of biological control systems of late blight of tomatoes in protected ground have quite significant prospects in comparison with the use of popular active ingredients of classical fungicides. In particular, for the conditions of the region, in order to maintain the high efficiency of the protection system and guarantee a high level of yield and quality of tomatoes, we recommend a variant that provides for the maximum combination of such biological fungicides of complex action as Fitotsid-r, Effect, Trichodermin during the vegetation of tomatoes.

Synergistic and antagonistic interactions between plant defences and biological pest control

Plants have evolved various defence mechanisms against herbivorous pests, ranging from physical barriers (constitutive defences) to the release of toxins (induced defences) in response to an attack. Plant defences are not always target-specific and can also act against natural enemies of these pests. This could potentially become problematic when considering both plant defences and predators as part of an Integrated Pest Management (IPM) scheme. Here we used a predator-prey model to capture the population dynamics of a biological control system to investigate the conditions where both plant defences and biological control act synergistically, leading to better pest control, and under what condition antagonistic outcomes could be expected. Our results demonstrate that both antagonistic and synergistic interactions are observable under small changes in key parameters, such as predation and growth rates. We then compared the qualitative model predictions against a set of population dynamic experiments using the Orius laevigatus (Hemiptera: Anthocoridae) - Frankliniella occidentalis (Thysanoptera: Thripidae) predator-pest system on tomato plants. In particular, we investigated the effect of plant defence-induced changes in pest growth rates and predation rates. For this we compared wild-type tomato with a mutant unable to synthesise jasmonic acid, an induced defence mechanism against pest attack, whereas changes to predation rates were realised by using O. laevigatus predator strains that are, due to differences in size, differentially affected by the plant's trichome-based constitutive defences. In agreement with model predictions, the qualitative dynamics confirmed the existence of both antagonistic and synergistic outcomes. Our results highlight the importance of considering multi-trophic interactions for the development of effective IPMs.

The interplay of intercropping, wildflower strips and weeds in conservation biological control and productivity

AbstractDifferent diversification practices have the potential to reduce pests and therefore pesticide use. Yet, their integration at the agroecosystem level and the evaluation of their multifunctional effects remain limited. Through a two-year field experiment conducted in Germany, we tested whether associating intercropping (faba bean-wheat, followed by breadseed poppy-barley) with pluriannual wildflower strips strengthens the biological regulation of aphid pests and weeds, and enhances cropping system productivity. The contribution of flowering weeds to conservation biological control was also analysed. Aphid but also predator colonization and predation rates on bean and poppy were consistently lower in intercropping compared to sole cropping. Wildflower strips enhanced aphid predation in bean-wheat intercropping, and further reduced aphid colonization at 10 m distance but not at 20 m in poppy-barley intercropping. Weed biomass was consistently reduced in intercropping compared to sole cropping bean and poppy, and did not significantly affect bean and poppy yields in intercropping. The cover of one flowering weed species, Matricaria recutita, was negatively correlated to aphid colonization and positively correlated to predation rate. Matricaria recutita flowers were also visited more often by predatory hoverflies in plots adjacent to wildflower strips. Finally, land equivalent ratio was consistently higher than 1, and the highest in bean-wheat intercropping associated to wildflower strips. The study demonstrates the benefits of associating wildflower strips to intercropping to strengthen biological control and cropping system productivity. Flowering weeds, maintained at an acceptable level through intercropping, turn out to be relevant functional biodiversity in interacting with wildflower strips for conservation biological control.

Compliant control of biomimetic parallel torso based on musculoskeletal control

Compliant movement and stress buffering of the torso are particularly important for state transition during high-speed locomotion in quadrupedal mammals. Currently, passive compliant control is commonly used in bionic torsos of quadruped robots, while active compliant control remains rare and immature. In previous research, we developed an active six-Degree-of-Freedom (DoF) bionic parallel torso. In this paper, we establish a muscle model that includes four biomechanical elements representing muscle characteristics (muscle force-fiber length and muscle velocity relationships) from the perspective of biology and physiology. We propose a musculoskeletal model that simulates the biological motion control system to control the compliant movement of each joint of the parallel mechanism. This model includes: 1) a neural equilibrium point controller that represents the transmission of motion commands, 2) activation dynamics that describe the activation of stimulated muscles, 3) contraction dynamics that emphasize the biomechanical characteristics of muscle tendons, 4) skeletal dynamics that describe bone movement. The effects of flexor and extensor stimulation on muscle activation, force, length, and velocity were analyzed. The results showed that both the flexor and extensor muscles will contract after corresponding stimulation. Furthermore, adjusting muscle stimulation through the musculoskeletal model can drive the parallel mechanism to reach the desired position. The musculoskeletal control method based on external force feedback can establish new torque balance in joints and drive the parallel torso to achieve compliant movements. Simulation and experiments have demonstrated the feasibility of the musculoskeletal control method. This method enhances the compliance and environmental adaptability of the parallel torso in practical applications.

Impact of PET/CT Imaging with FDG in Locally Advanced Cervical Carcinoma-A Literature Review.

Positron emission tomography (PET) and computed tomography (CT) have evolved as a pivotal diagnostic modality in the field of oncology. With its increasing application in staging and ready availability, it becomes imperative for committed radiation oncologists to possess a complete analysis and understanding of integration of molecular imaging, which can be helpful for radiation planning, while also acknowledging its possible limitations and challenges. A significant obstacle lies in the synthesis and design of tumor-specific bmolecules for diagnosing and treating cancer. The utilization of radiation in medical biochemistry and biotechnology, encompassing diagnosis, therapy, and control of biological systems, is encapsulated under the umbrella term "nuclear medicine". Notably, the application of various radioisotopes in pharmaceutics has garnered significant attention, particularly in the realm of delivery systems for drugs, DNA, and imaging agents. The present article provides a comprehensive review of use of novel techniques PET and CT with major positron-emitting radiopharmaceuticals currently in progress or utilized in clinical practice with their integration into imaging and radiation therapy.

Altered biological control species interactions despite phenological synchrony along an urban–rural temperature gradient

Biological control programs provide simplified systems in which to investigate the influence of temperature on trophic interactions. We investigated the interaction between the invasive thistle Carduus nutans and its specialist herbivore, the biological control agent weevil Rhinocyllus conicus, along a temperature gradient spanning an urban-to-rural urbanization gradient in central Pennsylvania. As expected, more urbanized sites were warmer than rural sites. Nevertheless, C. nutans phenology was only slightly earlier at warmer sites, and the timing of observations of adult R. conicus on thistles did not shift earlier, leaving synchrony apparently unchanged. Despite unchanged phenological matching, seasonal patterns in weevil damage varied with temperature: early-appearing capitula at warmer sites were more heavily damaged than early capitula at cooler sites, yet overall a lower proportion of capitula was damaged at warmer sites. Rising temperatures may therefore reduce effectiveness of R. conicus for C. nutans control, as more capitula escape damage. Biological control systems and naturally occurring temperature gradients are useful systems in which to investigate climate change impacts, but a focus on the phenology of organisms’ presence or absence may not be sufficient; our study demonstrates that consideration of the interaction itself may be necessary.

Topological Insights into Nanostar Dendrimers by Computing the Augmented Zagreb Index.

The field of nanobiotechnology uses precise nanofabrication techniques to advance our understanding and control of biological systems. Due to their remarkable properties, dendrimers, which are hyperbranched macromolecular structures with distinct and well-defined architectures, have emerged as pivotal entities within this field. They are gaining increasing attention for their potential to catalyze a paradigm shift in medical therapeutics, biotechnological applications, and advanced material sciences. This paper focuses on a novel analytical expression and determines the precise value of the augmented Zagreb index, a topological descriptor, for eight classes of nanostar dendrimers. The Zagreb index is a topological invariant to predict molecular behaviour and reactivity. In this paper, we have explored its application in characterizing the branching of nanostar dendrimers through computational modelling and mathematical rigor. Our research has measured the augmented Zagreb index for nanostar dendrimers, which fall into eight distinct classes. The results better explain the relationship between the dendrimers' topology and chemical properties. This correlation has implications for their structural stability and reactivity, potentially leading to new applications. Developing the augmented Zagreb index for nanostar dendrimers is a significant breakthrough in nanobiotechnology. Based on the correlation between the calculated topological index and the corresponding molecular attributes, our analytical approach has opened up new possibilities for designing and synthesizing dendrimers tailored to specific functions in medical and material science applications. This precise topological quantification could significantly enhance the utility and functionalization of dendrimers in cutting-edge nanotechnological applications.

Do biological control agents adapt to local pest genotypes? A multiyear test across geographic scales.

Parasite local adaptation has been a major focus of (co)evolutionary research on host-parasite interactions. Studies of wild host-parasite systems frequently find that parasites paired with local, sympatric host genotypes perform better than parasites paired with allopatric host genotypes. In contrast, there are few such tests in biological control systems to establish whether biological control parasites commonly perform better on sympatric pest genotypes. This knowledge gap prevents the optimal design of biological control programs: strong local adaptation could argue for the use of sympatric parasites to achieve consistent pest control. To address this gap, we tested for local adaptation of the biological control bacterium Pasteuria penetrans to the root-knot nematode Meloidogyne arenaria, a global threat to a wide range of crops. We measured the probability and intensity of P. penetrans infection on sympatric and allopatric M. arenaria over the course of 4 years. Our design accounted for variation in adaptation across scales by conducting tests within and across fields, and we isolated the signature of parasite adaptation by comparing parasites collected over the course of the growing season. Our results are largely inconsistent with local adaptation of P. penetrans to M. arenaria: in 3 of 4 years, parasites performed similarly well in sympatric and allopatric combinations. In 1 year, however, infection probability was 28% higher for parasites paired with hosts from their sympatric plot, relative to parasites paired with hosts from other plots within the same field. These mixed results argue for population genetic data to characterize the scale of gene flow and genetic divergence in this system. Overall, our findings do not provide strong support for using P. penetrans from local fields to enhance biological control of Meloidogyne.

Bacterial chemotaxis control process analysis with SysML

AbstractThis paper looks at the bacteria chemotaxis control process utilizing the System Modeling Language (SysML) to leverage well‐defined and proven engineering tools for architecting, analyzing, and refining complex systems. It proposes a new methodology called reverse‐engineering object‐oriented systems engineering method (RE‐OOSEM) that converts descriptive biology research information into descriptive systems engineering information. It utilizes SysML and model‐based systems engineering (MBSE) to capture system architecture from biological system knowledge and inputs them into systems engineering tools. From an engineering point of view, this allows greater insight into how biological systems operate and suggests how much model detail is required to uncover a top‐down system understanding. RE‐OOSEM methodology guides the SysML chemotaxis control capture process. SysML syntax is used instead of biological syntax to facilitate biological chemotaxis control system analysis from an engineered system point of view. The model can act as a scaffolding to help uncover system function, the relationships of system components and processes, and bioinformatic phenotype and genotype correlation. An executable MathWorks Stateflow chemotaxis control process model based on the SysML architectural model is included. The results show the following engineering perspective observations. (1) Several control components are not dedicated but are available and utilized when needed. (2) Individual chemoreceptors act together as a sensor array. (3) Phosphate groups act as a signaling mechanism. (4) Methylation via CH3 groups of the chemoreceptor results in sensitivity adaptation. (5) Closed‐loop control collaboratively utilizes ligand bonding, phosphorylation, and methylation. (6) Timing relationships of the control subprocesses give insight into the system's architecture.

Ideal adaptive control in biological systems: an analysis of P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {P}$$\\end{document}-invariance and dynamical compensation properties

BackgroundDynamical compensation (DC) provides robustness to parameter fluctuations. As an example, DC enables control of the functional mass of endocrine or neuronal tissue essential for controlling blood glucose by insulin through a nonlinear feedback loop. Researchers have shown that DC is related to the structural unidentifiability and the P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {P}$$\\end{document}-invariance property. The P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {P}$$\\end{document}-invariance property is a sufficient and necessary condition for the DC property. DC has been seen in systems with at least three dimensions. In this article, we discuss DC and P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {P}$$\\end{document}-invariance from an adaptive control perspective. An adaptive controller automatically adjusts its parameters to optimise performance, maintain stability, and deal with uncertainties in a system.ResultsWe initiate our analysis by introducing a simplified two-dimensional dynamical model with DC, fostering experimentation and understanding of the system’s behavior. We explore the system’s behavior with time-varying input and disturbance signals, with a focus on illustrating the system’s P\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {P}$$\\end{document}-invariance properties in phase portraits and step-like response graphs.ConclusionsWe show that DC can be seen as a case of ideal adaptive control since the system is invariant to the compensated parameter.

The Metabolic Syndrome, a Human Disease.

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Redox-enabled electronic interrogation and feedback control of hierarchical and networked biological systems

Microelectronic devices can directly communicate with biology, as electronic information can be transmitted via redox reactions within biological systems. By engineering biology’s native redox networks, we enable electronic interrogation and control of biological systems at several hierarchical levels: proteins, cells, and cell consortia. First, electro-biofabrication facilitates on-device biological component assembly. Then, electrode-actuated redox data transmission and redox-linked synthetic biology allows programming of enzyme activity and closed-loop electrogenetic control of cellular function. Specifically, horseradish peroxidase is assembled onto interdigitated electrodes where electrode-generated hydrogen peroxide controls its activity. E. coli’s stress response regulon, oxyRS, is rewired to enable algorithm-based feedback control of gene expression, including an eCRISPR module that switches cell-cell quorum sensing communication from one autoinducer to another—creating an electronically controlled ‘bilingual’ cell. Then, these disparate redox-guided devices are wirelessly connected, enabling real-time communication and user-based control. We suggest these methodologies will help us to better understand and develop sophisticated control for biology.

The strategy of optimal control for managing sugarcane shoot borer larvae

Pests and plant diseases pose significant challenges to Indonesia's agricultural development of sugar cane. The fall in national sugar productivity can be attributed, in part, to the presence of sugar cane shoot borer bugs. Managing sugar cane shoot borer pests is a crucial aspect of agriculture. The objective of this scientific study is to ascertain the optimal approach for the introduction of parasitoid larvae of sugarcane shoot borer pests. This will be done by looking at the Lotka-Volterra equation's stability and finding the best way to control it. This is a mathematical model used to show how biological control systems work. Specifically, the study focuses on the biological control of sugarcane shoot borer pests using their parasitic larvae, the Diatraeophaga striatalis Towns. The researchers opted for the qualitative descriptive approach, employing analytical tools derived from Miles and Huberman's four-stage framework. The equilibrium point and optimal control analyses show that the model presents various outcomes with distinct methods. These findings will be further examined in the subsequent sections of this paper.

Research progress in biological control of tomato bacterial wilt.

Bacterial wilt caused by the infection of Ralstonia solanacearum, is one of the most harmful diseases to tomatoes, one of the most important greenhouse vegetables in China. R. solanacearum can survive and remain active in the deep soil for a long time, and the chemical control of tomato bacterial wilt is consequently limited. In this study, we introduced the characteristics of tomato bacterial wilt disease and the types of R. solanacearum, and systematically reviewed the research progresses of biological control methods from the aspects of botanical insecticides, agricultural antibiotics, biocontrol bacteria. We emphatically introduced the principle and current status of these methods, discussed the limitations and the improvement strategies, and prospected a new environmental protection and efficient biological control system based on micro-ecological regulation would be the development direction of biological control of tomato bacterial wilt.

CYBERSECURITY ANALYSIS OF INDUSTRIAL CONTROL SYSTEMS

The current frontiers in the description and simulation of advanced physical and biological Industrial control systems (ICS) used to control various critical industrial and social systems. ICS integrates modern computing, communication, and Internet technologies. The integration of these technologies makes ICS open to the outside world, which makes it vulnerable to various cyber-attacks. ICS’s cybersecurity is becoming one of the most important issues due to the significant damage caused by cyberattacks to organizations and society. This article analyzes the cybersecurity issues of ICS. In particular, an analysis of the main components and architectures of the ICS, security aspects of the ICS, vulnerabilities, and threats to the cybersecurity of the ICS, as well as measures and means to ensure the cybersecurity of the ICS, is carried out. The analysis will help to give some insight into the cybersecurity issues of ICS and identify various research objectives necessary to ensure the cybersecurity of ICS.

Systems Engineering Approach to Modeling and Analysis of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by airflow limitation. This study develops a systems engineering framework for representing important mechanistic details of COPD in a model of the cardiorespiratory system. In this model, we present the cardiorespiratory system as an integrated biological control system responsible for regulating breathing. Four engineering control system components are considered: sensor, controller, actuator, and the process itself. Knowledge of human anatomy and physiology is used to develop appropriate mechanistic mathematical models for each component. Following a systematic analysis of the computational model, we identify three physiological parameters associated with reproducing clinical manifestations of COPD: changes in the forced expiratory volume, lung volumes, and pulmonary hypertension. We quantify the changes in these parameters (airway resistance, lung elastance, and pulmonary resistance) as the ones that result in a systemic response that is diagnostic of COPD. A multivariate analysis of the simulation results reveals that the changes in airway resistance have a broad impact on the human cardiorespiratory system and that the pulmonary circuit is stressed beyond normal under hypoxic environments in most COPD patients.

Dynamics of a delay-induced prey–predator system with interaction between immature prey and predators

In biological pest control systems, several pests (including insects, mites, weeds, etc.) are controlled by biocontrol agents that rely primarily on predation. Following this biocontrol management ecology, we have created a three-tier prey–predator model with prey phase structure and predator gestation delay. Several studies have demonstrated that predators with Holling type-II functional responses sometimes consume immature prey. A study of the well-posedness and local bifurcation (such as saddle-node and transcritical) near the trivial and planer equilibrium points is carried out. Without any time lag, the prey development coefficient has a stabilizing impact, while increasing attack rate accelerates instability. Energy transformation rate and handling time are shown to cause multiple stability switches in the system. Numerical results demonstrate time delay is the key destabilizer that destroys stability. Our model can replicate more realistic events by including time-dependent factors and exploring the dynamic behavior of nonautonomous systems. In the presence of time delay, sufficient conditions of permanence and global attractivity of the nonautonomous system are derived. Finally, MATLAB simulations are performed to validate the analytical findings.

A Dynamic Control Center Based on a DNA Reaction Network for Programmable Building of DNA Nanostructures.

DNA-based nanostructures allow for complex self-assembly with nanometer precision through the specificity of Watson-Crick base pairing, but network behavior-directed control of the kinetic process is less studied. Here we show how the DNA reaction network (DRN), which has emerged as a reliable and programmable way to implement artificial network dynamics, can be built as the control center of programmable nanostructures, allowing spatiotemporal control over the dynamic behavior of DNA nanotubes. We chose a common network motif in biological control systems, the feed-forward loop, as the model network and demonstrated that dynamic behaviors, such as self-tuning control and multilayer hierarchical assembly, could be programmed by constructing an inhibition network and an excitation network, separately, in buffer solution and inside protocells.