scholarly journals Modelling the Phosphorylation of Glucose by Human hexokinase I

Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2315
Author(s):  
Vinh Q. Mai ◽  
Martin Meere
Keyword(s):  
Mathematical Model ◽  
Sensitivity Analysis ◽  
Inorganic Phosphate ◽  
Global Sensitivity Analysis ◽  
Experimental Studies ◽  
Inhibitory Process ◽  
Cellular Regulation ◽  
Inhibitory Processes ◽  
Glucose Phosphorylation ◽  
Phosphorylation Rate

In this paper, we develop a comprehensive mathematical model to describe the phosphorylation of glucose by the enzyme hexokinase I. Glucose phosphorylation is the first step of the glycolytic pathway, and as such, it is carefully regulated in cells. Hexokinase I phosphorylates glucose to produce glucose-6-phosphate, and the cell regulates the phosphorylation rate by inhibiting the action of this enzyme. The cell uses three inhibitory processes to regulate the enzyme: an allosteric product inhibitory process, a competitive product inhibitory process, and a competitive inhibitory process. Surprisingly, the cellular regulation of hexokinase I is not yet fully resolved, and so, in this study, we developed a detailed mathematical model to help unpack the behaviour. Numerical simulations of the model produced results that were consistent with the experimentally determined behaviour of hexokinase I. In addition, the simulations provided biological insights into the abstruse enzymatic behaviour, such as the dependence of the phosphorylation rate on the concentration of inorganic phosphate or the concentration of the product glucose-6-phosphate. A global sensitivity analysis of the model was implemented to help identify the key mechanisms of hexokinase I regulation. The sensitivity analysis also enabled the development of a simpler model that produced an output that was very close to that of the full model. Finally, the potential utility of the model in assisting experimental studies is briefly indicated.

Global sensitivity analysis in a mathematical model of the renal insterstitium

2017 ◽  
Vol 10 (4) ◽  
pp. 625-649
Author(s):  
Mariel Bedell ◽  
Yilin Lin ◽  
Emmie Román-Meléndez ◽  
Ioannis Sgouralis
Keyword(s):  
Mathematical Model ◽  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Global Sensitivity

scholarly journals Uncertainty and sensitivity analysis applied to a rammed earth wall: evaluation of the discrepancies between experimental and numerical data

2020 ◽  
Vol 172 ◽  
pp. 17004
Author(s):  
Rudy Bui ◽  
Jeanne Goffart ◽  
Fionn McGregor ◽  
Monika Woloszyn ◽  
Antonin Fabbri ◽  
...  
Keyword(s):  
Experimental Data ◽  
Sensitivity Analysis ◽  
Relative Humidity ◽  
Vapour Pressure ◽  
Building Materials ◽  
Global Sensitivity Analysis ◽  
Experimental Studies ◽  
Rammed Earth ◽  
Global Sensitivity ◽  
Rammed Earth Wall

Due to the environmental impact of building materials, researches on sustainable materials, such as bio-based and earth materials, are now widespread. These materials offer numerous qualities such as their availability, recyclability and their ability to dampen the indoor relative humidity variations due to their hygroscopicity. As these materials can absorb large amount of humidity, numerical and experimental studies of their hygrothermal behaviour are crucial to assess their durability. To validate a hygrothermal model, numerical and experimental data have to be confronted. Such confrontation must take into consideration the uncertainties related to the experimental protocol, but also to the model. Statistical tools such as uncertainty and global sensitivity analysis are essential for this task. The uncertainty analysis estimates the robustness of the model, while the global sensitivity analysis identifies the most influential input(s) responsible for this robustness. However, these methods are not commonly used because of the complexity of hygrothermal models, and therefore the prohibitive simulation cost. This study presents a methodology for comparing the numerical and experimental data of a rammed earth wall subjected to varying temperature and relative humidity conditions. The main objectives are the investigation of the uncertainties impact, the estimation of the model robustness, and finally the identification of the input(s) responsible for the discrepancies between numerical and experimental data. To do so, a recent and low-cost global variance-based sensitivity method, named RBD-FAST, is applied. First, the uncertainty propagation through the model is calculated, then the sensitivity indices are estimated. They represent the part of the output variability related to each input variability. The output of interest is the vapour pressure in the middle of the wall to confront it to the experimental measurement. Good agreement is obtained between the experimental and numerical results. It is also highlighted that the sorption isotherm is the main factor influencing the vapour pressure in the material.

scholarly journals A local and global sensitivity analysis of a mathematical model of coagulation and platelet deposition under flow

PLoS ONE ◽  
2018 ◽  
Vol 13 (7) ◽  
pp. e0200917 ◽  
Author(s):  
Kathryn G. Link ◽  
Michael T. Stobb ◽  
Jorge Di Paola ◽  
Keith B. Neeves ◽  
Aaron L. Fogelson ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Global Sensitivity ◽  
Platelet Deposition

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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