IDENTIFICATION OF HYBRID DYNAMICAL SYSTEM IN GLYCEROL FERMENTATION: ESTIMATING THE INHIBITION RANGE OF 3-HPA ONTO TWO KEY ENZYMES BASED ON BIOLOGICAL ROBUSTNESS

2013 ◽  
Vol 06 (05) ◽  
pp. 1350032
Author(s):  
HONGLI WANG ◽  
LEI WANG ◽  
DANDAN DAI ◽  
ENMIN FENG ◽  
ZHILONG XIU
Keyword(s):  
Dynamical System ◽  
Inhibitory Action ◽  
Identification Problem ◽  
Specific Rate ◽  
Hybrid Dynamical System ◽  
Important Intermediate ◽  
Definition Of ◽  
Quantitative Definition ◽  
Biological Robustness ◽  
Intermediate Substance

As an important intermediate substance in the process of producing 1,3-propanediol (1,3-PD) by bio-dissimilation of glycerol, the concentration of 3-hydroxypropionaldehyde (3-HPA) has inhibitory action on glycerol dehydratase (GDHt) and 1,3-propanediol oxidoreductase (PDOR). Considering the transmission of glycerol and 1,3-PD across cell membrane by both passive diffusion and active transmission as well as the inhibitory action of 3-HPA on the specific rate of growth, this paper aims to establish and discuss a nonlinear hybrid dynamical system model to ascertain the concentration range of 3-HPA where it does exhibit an inhibitory action on GDHt and PDOR. A quantitative definition of biological robustness is presented and an identification model is established based on biological robustness. An algorithm procedure is constructed to solve the identification problem. Numerical results show that only within a proper concentration range 3-HPA can have inhibitory action on the two enzymes mentioned above.

scholarly journals Defining and Quantifying Intermittency in the Power Sector

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3366
Author(s):  
Daniel Suchet ◽  
Adrien Jeantet ◽  
Thomas Elghozi ◽  
Zacharie Jehl
Keyword(s):  
Power Source ◽  
Production Data ◽  
Power Sector ◽  
Predictive Capacity ◽  
The Public ◽  
Current State ◽  
Definition Of ◽  
Quantitative Definition ◽  
The Impact

The lack of a systematic definition of intermittency in the power sector blurs the use of this term in the public debate: the same power source can be described as stable or intermittent, depending on the standpoint of the authors. This work tackles a quantitative definition of intermittency adapted to the power sector, linked to the nature of the source, and not to the current state of the energy mix or the production predictive capacity. A quantitative indicator is devised, discussed and graphically depicted. A case study is illustrated by the analysis of the 2018 production data in France and then developed further to evaluate the impact of two methods often considered to reduce intermittency: aggregation and complementarity between wind and solar productions.

scholarly journals Mathematical Analysis of an Epidemic-Species Hybrid Dynamical System

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jing Hui ◽  
Jian-Hua Pang ◽  
Dong-Rong Lin
Keyword(s):  
Dynamical System ◽  
Hopf Bifurcation ◽  
Local Stability ◽  
Orbital Stability ◽  
Species Hybrid ◽  
Hybrid Dynamical System ◽  
Mathematical Analyses ◽  
Existence Of Equilibria ◽  
Impulsive Releasing ◽  
Infected Prey

We consider an epidemic-species hybrid dynamical system. The disease is spread among the prey only and the infected prey can reproduce virus. The predator only eats the infected prey. Mathematical analyses are given for the system with regard to the existence of equilibria, local stability, Hopf bifurcation, and the orbital stability of the Hopf bifurcating limit cycle. We further analyse the system under impulsive releasing of virus and predator.

scholarly journals Quantifying Legal Entropy

2021 ◽  
Vol 9 ◽  
Author(s):  
Ted Sichelman
Keyword(s):  
Information Theory ◽  
Information Content ◽  
Legal System ◽  
Legal Systems ◽  
Information Costs ◽  
Precise Quantification ◽  
The Law ◽  
Legal Contexts ◽  
Definition Of ◽  
Quantitative Definition

Many scholars have employed the term “entropy” in the context of law and legal systems to roughly refer to the amount of “uncertainty” present in a given law, doctrine, or legal system. Just a few of these scholars have attempted to formulate a quantitative definition of legal entropy, and none have provided a precise formula usable across a variety of legal contexts. Here, relying upon Claude Shannon's definition of entropy in the context of information theory, I provide a quantitative formalization of entropy in delineating, interpreting, and applying the law. In addition to offering a precise quantification of uncertainty and the information content of the law, the approach offered here provides other benefits. For example, it offers a more comprehensive account of the uses and limits of “modularity” in the law—namely, using the terminology of Henry Smith, the use of legal “boundaries” (be they spatial or intangible) that “economize on information costs” by “hiding” classes of information “behind” those boundaries. In general, much of the “work” performed by the legal system is to reduce legal entropy by delineating, interpreting, and applying the law, a process that can in principle be quantified.

scholarly journals A VARIATIONAL FORMULATION OF SYMPLECTIC NONCOMMUTATIVE MECHANICS

2007 ◽  
Vol 04 (05) ◽  
pp. 789-805 ◽  
Author(s):  
IGNACIO CORTESE ◽  
J. ANTONIO GARCÍA
Keyword(s):  
Dynamical System ◽  
Phase Space ◽  
Variational Principle ◽  
Configuration Space ◽  
Variational Formulation ◽  
Noncommutative Space ◽  
First Order ◽  
Dynamical Properties ◽  
Definition Of ◽  
Space Noncommutativity

The standard lore in noncommutative physics is the use of first order variational description of a dynamical system to probe the space noncommutativity and its consequences in the dynamics in phase space. As the ultimate goal is to understand the inherent space noncommutativity, we propose a variational principle for noncommutative dynamical systems in configuration space, based on results of our previous work [18]. We hope that this variational formulation in configuration space can be of help to elucidate the definition of some global and dynamical properties of classical and quantum noncommutative space.

scholarly journals Shape Analysis of the Patellar Bone Surface and Cutting Plane for Knee Replacement Surgery

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
E. L. Rex ◽  
J. Werle ◽  
B. C. Burkart ◽  
J. R. MacKenzie ◽  
K. D. Johnston ◽  
...  
Keyword(s):  
Knee Replacement ◽  
Shape Analysis ◽  
Cutting Plane ◽  
X Rays ◽  
Anterior Surface ◽  
Knee Replacement Surgery ◽  
Replacement Surgery ◽  
Contact Points ◽  
Definition Of ◽  
Quantitative Definition

Geometry of the patella (kneecap) remains poorly understood yet is highly relevant to performing the correct patellar cut to reduce pain and to improve function and satisfaction after knee replacement surgery. Although studies routinely refer to “parallel to the anterior surface” and “the patellar horizon,” a quantitative definition of these is lacking and significant variability exists between observers for this irregularly-shaped bone. A 2D-3D shape analysis technique was developed to determine the optimal device configuration for contacting the patellar surface. Axial and sagittal pseudo-X-rays were created from 18 computed tomography (CT) scans of cadaveric knees. Four expert surgeons reviewed three repetitions of the X-rays in randomized order, marking their desired cut plane and their estimate of the anterior surface. These 2D results were related back to the 3D model to create the desired plane. There was considerable variability in perceptions, with intra- and intersurgeon repeatability (standard deviations) ranging from 1.3° to 2.4°. The best configuration of contact points to achieve the desired cutting plane was three pegs centred on the patellar surface, two superior and one inferior, forming a 16 mm equilateral triangle. This configuration achieved predicted cut planes within 1° of the surgeon ranges on all 18 patellae. Implementing this, as was done in a subsequent prototype surgical device, should help improve the success and satisfaction of knee replacement surgery.

scholarly journals A substrate-independent framework to characterize reservoir computers

2019 ◽  
Vol 475 (2226) ◽  
pp. 20180723 ◽  
Author(s):  
Matthew Dale ◽  
Julian F. Miller ◽  
Susan Stepney ◽  
Martin A. Trefzer
Keyword(s):  
Dynamical System ◽  
Task Performance ◽  
Fading Memory ◽  
Reservoir Computing ◽  
Virtual Topology ◽  
Nonlinear Input ◽  
Definition Of ◽  
Substrate Independent ◽  
And Task

The reservoir computing (RC) framework states that any nonlinear, input-driven dynamical system (the reservoir ) exhibiting properties such as a fading memory and input separability can be trained to perform computational tasks. This broad inclusion of systems has led to many new physical substrates for RC. Properties essential for reservoirs to compute are tuned through reconfiguration of the substrate, such as change in virtual topology or physical morphology. As a result, each substrate possesses a unique ‘quality’—obtained through reconfiguration—to realize different reservoirs for different tasks. Here we describe an experimental framework to characterize the quality of potentially any substrate for RC. Our framework reveals that a definition of quality is not only useful to compare substrates, but can help map the non-trivial relationship between properties and task performance. In the wider context, the framework offers a greater understanding as to what makes a dynamical system compute, helping improve the design of future substrates for RC.

scholarly journals P1764 A unifying concept for the quantitative definition of functional mitral regurgitation

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
P Bartko ◽  
H Arfsten ◽  
G Heitzinger ◽  
N Pavo ◽  
A Toma ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Cox Regression ◽  
Expert Consensus ◽  
Functional Mitral Regurgitation ◽  
Complex Nature ◽  
P Value ◽  
Intermediate Risk ◽  
Cox Regression Analysis ◽  
Definition Of ◽  
Quantitative Definition

Abstract Background Diverging guideline definitions for the quantitative assessment of severe secondary mitral regurgitation (sMR) reflect the lacking link of the sMR spectrum to mortality and has introduced a source of uncertainty and continuing debate. Objectives The current study aimed to define improved risk-thresholds specifically tailored to the complex nature of sMR that provide a unifying solution to the ongoing guideline-controversy. Methods We enrolled 423 heart failure patients under guideline directed medical therapy and assessed sMR by effective regurgitant orifice area (EROA), regurgitant volume (RegVol) and regurgitant fraction (RegFrac). Results Measures of sMR severity were consistently associated with 5-year mortality with a HR for a 1-SD increase of 1.42 (95%CI 1.25-1.63, P < 0.001) for EROA, 1.37 (95%CI 1.20-1.56, P < 0.001) for RegVol and 1.50 (95%CI 1.30-1.73, P < 0.001) for RegFrac. Results remained statistically significant after bootstrap- or clinical confounder-based adjustment. Spline-curve analyses (Figure 1A-C) showed a linearly increasing risk enabling to stratify in low-risk (EROA < 20mm2 and RegVol < 30ml), intermediate-risk (EROA 20-30mm2 and RegVol 30-45ml) and, high-risk (EROA≥30mm2 and RegVol≥45ml). In the intermediate-risk group, a RegFrac ≥50% as indicator for hemodynamic severe sMR was associated with poor outcome (P = 0.017). A unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac (Figure 1D) showed a significantly better discrimination compared to the currently established algorithms (Table 1). Conclusions Risk-based thresholds tailored to the pathophysiological concept of sMR provide a unifying solution to the ongoing guideline controversy. An algorithm based on the combined assessment of the unifying cut-offs for EROA, RegVol and RegFrac improves risk prediction compared to currently established grading. Table 1 Definition of severe sMR Cox regression analysis ROC analysis IDI analysis HR (95%CI) P-Value ROC P-Value-for-comparison IDI P-Value Unifying concept 3.76 (2.71-5.23) <0.001 0.63 –- –- –- ACC/AHA definition 3.20 (2.14-4.78) <0.001 0.57 <0.001 0.06 <0.001 ESC/EACTS definition 1.52 (1.10-2.09) 0.01 0.55 <0.001 0.13 <0.001 ACC/ASE expert consensus 1.89 (1.40-2.56) <0.001 0.59 0.04 0.08 <0.001 Comparison of the unifying concept with the ACC/AHA, ESC/EACTS and ACC/ASE expert consensus definitions of sMR by Cox regression, ROC, and IDI demonstrated the most powerfull prediction by the unifying concept with significantly higher ROC area under the curve and better discriminatory power by IDI. Abstract P1764 Figure 1 A-D

Sign in / Sign up

Export Citation Format

Share Document