Techniques in Discrete and Continuous Robust Systems

1996 ◽  
Keyword(s):  
Robust Systems

scholarly journals Attenuated SIRT1 Activity Leads to PER2 Cytoplasmic Localization and Dampens the Amplitude of Bmal1 Promoter-Driven Circadian Oscillation

2021 ◽  
Vol 15 ◽  
Author(s):  
Atsushige Ashimori ◽  
Yasukazu Nakahata ◽  
Toshiya Sato ◽  
Yuichiro Fukamizu ◽  
Takaaki Matsui ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Circadian Clock ◽  
Posttranslational Modifications ◽  
Cultured Cells ◽  
Circadian Oscillation ◽  
Clock Proteins ◽  
Circadian Clock Proteins ◽  
Circadian Physiology ◽  
And Behavior ◽  
Robust Systems

The circadian clock possesses robust systems to maintain the rhythm approximately 24 h, from cellular to organismal levels, whereas aging is known to be one of the risk factors linked to the alternation of circadian physiology and behavior. The amount of many metabolites in the cells/body is altered with the aging process, and the most prominent metabolite among them is the oxidized form of nicotinamide adenine dinucleotide (NAD+), which is associated with posttranslational modifications of acetylation and poly-ADP-ribosylation status of circadian clock proteins and decreases with aging. However, how low NAD+ condition in cells, which mimics aged or pathophysiological conditions, affects the circadian clock is largely unknown. Here, we show that low NAD+ in cultured cells promotes PER2 to be retained in the cytoplasm through the NAD+/SIRT1 axis, which leads to the attenuated amplitude of Bmal1 promoter-driven luciferase oscillation. We found that, among the core clock proteins, PER2 is mainly affected in its subcellular localization by NAD+ amount, and a higher cytoplasmic PER2 localization was observed under low NAD+ condition. We further found that NAD+-dependent deacetylase SIRT1 is the regulator of PER2 subcellular localization. Thus, we anticipate that the altered PER2 subcellular localization by low NAD+ is one of the complex changes that occurs in the aged circadian clock.

scholarly journals Cell Line Platforms Support Research into Arthropod Immunity

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 738
Author(s):  
Cynthia L. Goodman ◽  
David S. Kang ◽  
David Stanley
Keyword(s):  
Immune Responses ◽  
Cell Line ◽  
Cell Lines ◽  
Cost Effective ◽  
Future Research ◽  
Innate Immune Responses ◽  
Pathogenic Viruses ◽  
Future Research Directions ◽  
Bacteria And Fungi ◽  
Robust Systems

Innate immune responses are essential to maintaining insect and tick health and are the primary defense against pathogenic viruses, bacteria, and fungi. Cell line research is a powerful method for understanding how invertebrates mount defenses against pathogenic organisms and testing hypotheses on how these responses occur. In particular, immortal arthropod cell lines are valuable tools, providing a tractable, high-throughput, cost-effective, and consistent platform to investigate the mechanisms underpinning insect and tick immune responses. The research results inform the controls of medically and agriculturally important insects and ticks. This review presents several examples of how cell lines have facilitated research into multiple aspects of the invertebrate immune response to pathogens and other foreign agents, as well as comments on possible future research directions in these robust systems.

scholarly journals Ecosystem antifragility: Beyond integrity and resilience

2019 ◽  
Author(s):  
Miguel Equihua Zamora ◽  
Mariana Espinosa ◽  
Carlos Gershenson ◽  
Oliver López-Corona ◽  
Mariana Munguia ◽  
...  
Keyword(s):  
Information Theory ◽  
Real World ◽  
Environmental Variability ◽  
Theory Approach ◽  
Ecosystem Resilience ◽  
Ecosystem Response ◽  
Ecosystem Integrity ◽  
Real World Applications ◽  
The Subject ◽  
Robust Systems

We review the concept of ecosystem resilience in its relation to ecosystem integrity from an information theory approach. We summarize the literature on the subject identifying three main narratives: ecosystem properties that enable them to be more resilient; ecosystem response to perturbations; and complexity. We also include original ideas with theoretical and quantitative developments with application examples. The main contribution is a new way to rethink resilience, that is mathematically formal and easy to evaluate heuristically in real-world applications: ecosystem antifragility. An ecosystem is antifragile if it benefits from environmental variability. Antifragility therefore goes beyond robustness or resilience because while resilient/robust systems are merely perturbation-resistant, antifragile structures not only withstand stress but also benefit from it.

scholarly journals Ingredients for robustness

2020 ◽  
Vol 139 (4) ◽  
pp. 309-318
Author(s):  
Nihat Ay
Keyword(s):  
Structural Components ◽  
Input Output ◽  
Core Property ◽  
Robust Systems

AbstractA core property of robust systems is given by the invariance of their function against the removal of some of their structural components. This intuition has been formalised in the context of input–output maps, thereby introducing the notion of exclusion independence. We review work on how this formalisation allows us to derive characterisation theorems that provide a basis for the design of robust systems.

Characterization of Antifragility in Cyber Systems Using a Susceptibility Metric

2016 ◽  
Author(s):  
Erich Devendorf ◽  
Kayla Zeliff ◽  
Kamal Jabbour
Keyword(s):  
Engineering Design ◽  
Impulse Response ◽  
Design Practice ◽  
Reliable Systems ◽  
Robust Systems ◽  
Minimum Performance

Traditional engineering design practice seeks to create reliable systems that maintain a desired minimum performance when subjected to a defined set of impulses. To manage impulses, designers implement techniques to specify systems that are resilient or robust to impulses. Resilient systems perform with degraded capacity when subjected to impulses while robust systems remain unaffected by impulses. In this paper we examine antifragility, a complement to resilience and robustness, to manage the impulse response of complex cyber systems. Where fragile systems fracture when subjected to impulses, antifragile systems become stronger. We discuss why this strengthening characteristic makes antifragility attractive for managing impulse response in complex cyber systems and develop a measure for antifragility that differentiates it from fragility, resiliency and robustness. We then discuss an antifragile cyber system to demonstrate the benefits of antifragility in an impulse-rich environment.

Optimizing Offshore Combat of Oil Spills – Development of New Booms and Helicopter Based Application of Dispersants

2003 ◽  
Vol 2003 (1) ◽  
pp. 1279-1284
Author(s):  
Tharald M. Brekne ◽  
Sigmund Holmemo ◽  
Geir M. Skeie
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
New Technology ◽  
Geographic Location ◽  
Chemical Dispersant ◽  
Offshore Installations ◽  
The Status ◽  
Oil Spill Response ◽  
Robust Systems ◽  
Norwegian Continental Shelf

ABSTRACT There is an increasing focus on offshore combat of oil spills on the Norwegian Continental Shelf (NCS). One result of this focus is a change from field specific to area specific contingency, moving from many medium sized oil spill combat vessels, to fewer and more robust systems and vessels. An important element in the emerging configuration is the use of helicopter based chemical dispersant systems, permanently located on offshore installations. An increasing diversity, of oil types being produced, configuration of installations, water depths and geographic location, are all factors that require a robust, mobile and flexible oil spill response. The Norwegian Clean Seas Association for Operating Companies (NOFO) has recently initiated development of new technology, as projects under NOFO's Research & Development Programme. Three of these projects address the development of improved heavy offshore booms, applying new principles for containment of oil, and a heavy duty skimmer optimized for mobility. A fourth project addresses the development of a system for helicopter based application of chemical dispersants, optimized for offshore storage and maintenance. This paper presents the status for and experience from these projects, as well as the plan for testing and verification of this new technology.

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