Mathematical modeling and parameter estimation of levodopa motor response in patients with parkinson disease

AbstractIn recent years, mathematical modeling approaches have played a central role to understand and to quantify mechanisms in different viral infectious diseases. In this approach, biological-based hypotheses are expressed via mathematical relations and then tested based on empirical data. The simulation results can be used to either identify underlying mechanisms, provide predictions on infection outcomes, or evaluate the efficacy of a treatment.Conducting parameter estimation for mathematical models is not an easy task. Here we detail an approach to conduct parameter estimation and to evaluate the results using the free software R. The method is applicable to influenza virus dynamics at different complexity levels, widening experimentalists capabilities in understanding their data. The parameter estimation approach presented here can be also applied to other viral infections or biological applications.

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Mathematical Modeling and Parameter Estimation of Battery Lifetime using a Combined Electrical Model and a Genetic Algorithm

TEMA (São Carlos) ◽

10.5540/tema.2019.020.01.149 ◽

2019 ◽

Vol 20 (1) ◽

pp. 149 ◽

Cited By ~ 1

Author(s):

Marcia De Fatima Brondani Binelo ◽

Airam Teresa Zago Romcy Sausen ◽

Paulo Sérgio Sausen ◽

Manuel Osório Binelo

Keyword(s):

Mathematical Modeling ◽

Genetic Algorithm ◽

Parameter Estimation ◽

Visual Analysis ◽

Lithium Ion ◽

Electrical Model ◽

Pulsed Discharge ◽

Battery Lifetime ◽

Agile Process ◽

Discharge Curves

In this paper, a parametrization methodology based on the Genetic Algorithm meta-heuristic is proposed for the Chen and Rincón-Mora model parameter estimation, this model is used for the mathematical modeling of the Lithium-ion Polymer batteries lifetime. The model is also parametrized using the conventional procedures, which is based on the visual analysis of pulsed discharge curves, as presented in the literature. For both parametrization procedures, and for the model validation, experimental data obtained from a platform test are used. The results show that the proposed Genetic Algorithm is able to parametrize the model with better efficacy, presenting lower mean error, and also is a more agile process than the conventional one, been less subject to subjective aspects.

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Disentangling the Role of Cortico-Basal Ganglia Loops in Top–Down and Bottom–Up Visual Attention: An Investigation of Attention Deficits in Parkinson Disease

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00770 ◽

2015 ◽

Vol 27 (6) ◽

pp. 1215-1237 ◽

Cited By ~ 15

Author(s):

Giorgio Tommasi ◽

Mirta Fiorio ◽

Jérôme Yelnik ◽

Paul Krack ◽

Francesca Sala ◽

...

Keyword(s):

Visual Attention ◽

Parkinson Disease ◽

Attentional Capture ◽

Motor Response ◽

Response Selection ◽

The Other ◽

Top Down ◽

Movement Initiation ◽

Bottom Up ◽

Brain Functions

It is solidly established that top–down (goal-driven) and bottom–up (stimulus-driven) attention mechanisms depend on distributed cortical networks, including prefrontal and frontoparietal regions. On the other hand, it is less clear whether the BG also contribute to one or the other of these mechanisms, or to both. The current study was principally undertaken to clarify this issue. Parkinson disease (PD), a neurodegenerative disorder primarily affecting the BG, has proven to be an effective model for investigating the contribution of the BG to different brain functions; therefore, we set out to investigate deficits of top–down and bottom–up attention in a selected cohort of PD patients. With this objective in mind, we compared the performance on three computerized tasks of two groups of 12 parkinsonian patients (assessed without any treatment), one otherwise pharmacologically treated and the other also surgically treated, with that of a group of controls. The main behavioral tool for our study was an attentional capture task, which enabled us to tap the competition between top–down and bottom–up mechanisms of visual attention. This task was suitably combined with a choice RT and a simple RT task to isolate any specific deficit of attention from deficits in motor response selection and initiation. In the two groups of patients, we found an equivalent increase of attentional capture but also comparable delays in target selection in the absence of any salient distractor (reflecting impaired top–down mechanisms) and movement initiation compared with controls. In contrast, motor response selection processes appeared to be prolonged only in the operated patients. Our results confirm that the BG are involved in both motor and cognitive domains. Specifically, damage to the BG, as it occurs in PD, leads to a distinct deficit of top–down control of visual attention, and this can account, albeit indirectly, for the enhancement of attentional capture, reflecting weakened ability of top–down mechanisms to antagonize bottom–up control.

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