An Interdisciplinary Approach to Brain Tumor Growth Dynamics

2000 ◽  
Author(s):  
Salvatore Torquato ◽  
Thomas S. Deisboeck
Keyword(s):  
Brain Tumors ◽  
Tumor Growth ◽  
Computational Models ◽  
Growth Dynamics ◽  
Interdisciplinary Approach ◽  
Clinical Prognosis ◽  
Macroscopic Tumor ◽  
New Perspective ◽  
Clonal Composition

Abstract Intensive medical research over the last fifty years has left the prognosis for patients diagnosed with malignant brain tumors nearly unchanged. This suggests that a new perspective on the problem may offer important insight. We have undertaken an interdisciplinary research program, seeking to study brain tumors as complex systems. This research aims to develop computational models coupled with experimental assays to investigate the hypothesis of self-organizing behavior in tumor systems. Preliminary assays have revealed behavior consistent with this hypothesis. A cellular-automaton model to study the growth of the tumor core has been developed. This model has proven successful in reproducing macroscopic tumor growth from a limited parameter set. Further, it has been applied to investigate the importance of heterogeneity to determination of a clinical prognosis and has demonstrated the importance of understanding clonal composition in making an accurate prognosis.

scholarly journals Insight into Glutamatergic Involvement in Rewarding Effects of Mephedrone in Rats: In Vivo and Ex Vivo Study

2021 ◽  
Author(s):  
Olga Wronikowska ◽  
Maria Zykubek ◽  
Agnieszka Michalak ◽  
Anna Pankowska ◽  
Paulina Kozioł ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Interdisciplinary Approach ◽  
Nmda Antagonist ◽  
Exchange Chromatography ◽  
Resonance Spectroscopy ◽  
Monoamine Transporters ◽  
Ex Vivo Study ◽  
Insight Into

AbstractMephedrone is a widely used drug of abuse, exerting its effects by interacting with monoamine transporters. Although this mechanism has been widely studied heretofore, little is known about the involvement of glutamatergic transmission in mephedrone effects. In this study, we comprehensively evaluated glutamatergic involvement in rewarding effects of mephedrone using an interdisciplinary approach including (1) behavioural study on effects of memantine (non-selective NMDA antagonist) on expression of mephedrone-induced conditioned place preference (CPP) in rats; (2) evaluation of glutamate concentrations in the hippocampus of rats following 6 days of mephedrone administration, using in vivo magnetic resonance spectroscopy (MRS); and (3) determination of glutamate levels in the hippocampus of rats treated with mephedrone and subjected to MRS, using ion-exchange chromatography. In the presented research, we confirmed priorly reported mephedrone-induced rewarding effects in the CPP paradigm and showed that memantine (5 mg/kg) was able to reverse the expression of this effect. MRS study showed that subchronic mephedrone administration increased glutamate level in the hippocampus when measured in vivo 24 h (5 mg/kg, 10 mg/kg and 20 mg/kg) and 2 weeks (5 mg/kg and 20 mg/kg) after last injection. Ex vivo chromatographic analysis did not show significant changes in hippocampal glutamate concentrations; however, it showed similar results as obtained in the MRS study proving its validity. Taken together, the presented study provides new insight into glutamatergic involvement in rewarding properties of mephedrone.

scholarly journals On the modeling of the interaction between tumor growth and the immune system using some new fractional and fractional-fractal operators

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Behzad Ghanbari
Keyword(s):  
Immune System ◽  
Infectious Diseases ◽  
Tumor Growth ◽  
Computational Models ◽  
Recent Literature ◽  
Approximate Solutions ◽  
Biological Phenomena ◽  
Uniqueness Of The Solution ◽  
Biological Concepts ◽  
New Research

Abstract Humans are always exposed to the threat of infectious diseases. It has been proven that there is a direct link between the strength or weakness of the immune system and the spread of infectious diseases such as tuberculosis, hepatitis, AIDS, and Covid-19 as soon as the immune system has no the power to fight infections and infectious diseases. Moreover, it has been proven that mathematical modeling is a great tool to accurately describe complex biological phenomena. In the recent literature, we can easily find that these effective tools provide important contributions to our understanding and analysis of such problems such as tumor growth. This is indeed one of the main reasons for the need to study computational models of how the immune system interacts with other factors involved. To this end, in this paper, we present some new approximate solutions to a computational formulation that models the interaction between tumor growth and the immune system with several fractional and fractal operators. The operators used in this model are the Liouville–Caputo, Caputo–Fabrizio, and Atangana–Baleanu–Caputo in both fractional and fractal-fractional senses. The existence and uniqueness of the solution in each of these cases is also verified. To complete our analysis, we include numerous numerical simulations to show the behavior of tumors. These diagrams help us explain mathematical results and better describe related biological concepts. In many cases the approximate results obtained have a chaotic structure, which justifies the complexity of unpredictable and uncontrollable behavior of cancerous tumors. As a result, the newly implemented operators certainly open new research windows in further computational models arising in the modeling of different diseases. It is confirmed that similar problems in the field can be also be modeled by the approaches employed in this paper.

Interdisciplinary Approach for Wellbore Stability During Slimhole Drilling at Volga-Urals Basin Oilfield

2021 ◽  
Author(s):  
Anna Vladimirovna Norkina ◽  
Sergey Mihailovich Karpukhin ◽  
Konstantin Urjevich Ruban ◽  
Yuriy Anatoljevich Petrakov ◽  
Alexey Evgenjevich Sobolev
Keyword(s):  
Drilling Fluid ◽  
Interdisciplinary Approach ◽  
Wellbore Stability ◽  
Vertical Wells ◽  
Wellbore Instability ◽  
Water Based ◽  
Chemical Studies ◽  
Fluid Rheology ◽  
Selection Of

Abstract The design features and the need to use a water-based solution make the task of ensuring trouble-free drilling of vertical wells non-trivial. This work is an example of an interdisciplinary approach to the analysis of the mechanisms of instability of the wellbore. Instability can be caused by a complex of reasons, in this case, standard geomechanical calculations are not enough to solve the problem. Engineering calculations and laboratory chemical studies are integrated into the process of geomechanical modeling. The recommendations developed in all three areas are interdependent and inseparable from each other. To achieve good results, it is necessary to comply with a set of measures at the same time. The key tasks of the project were: determination of drilling density, tripping the pipe conditions, parameters of the drilling fluid rheology, selection of a system for the best inhibition of clay swelling.

scholarly journals Determination of conditions for spontaneous combustion of combustible dust deposits on equipment, in ventilation systems, and aspiration systems of buildings and structures

2020 ◽  
Vol 29 (4) ◽  
pp. 32-41
Author(s):  
L. P. Vogman ◽  
D. A. Korolchenko ◽  
A. V. Khryukin
Keyword(s):  
Spontaneous Combustion ◽  
Growth Dynamics ◽  
Operating Conditions ◽  
Industrial Enterprises ◽  
Process Characteristics ◽  
Industrial Buildings ◽  
Dust Deposits ◽  
Production Facilities ◽  
Ventilation Systems

Introduction. Determination of the scientifi cally substantiated frequency of cleaning the ducts of local exhausts of industrial buildings and structures is one of the tasks in the fi eld of fi re safety of industrial enterprises. The paper describes design methods, in particular, a method for determination of the induction period during spontaneous combustion of dust deposits in air ducts of ventilation systems and equipment, which can be used in solving problems focused on the development of preventive measures to ensure their fi re and explosion safety.Methods. In order to solve the problem set in this paper and compare the indicators obtained in the calculation and analytical part of the studies with the growth dynamics of deposits in real facilities, fi eld tests have been accomplished in the production facilities of the fl our mill of OJSC MK “Voronezhsky” and JSC Concern “Sozvezdiye”.Results and discussion. The timeframes for cleaning of deposits on ventilation (aspiration) equipment of buildings and structures cannot be universal for various industries and must take into account the dynamics of the growth of deposits depending on the specifi cs of combustible deposits, the workload of the production facilities of the protected object in a given period of time, and the operating conditions of the equipment. As a result of the experiments, it was found that the places of maximum accumulations of deposits are most often formed on the surfaces of joints and on the bends of pipelines of ventilation systems. The conditions of spontaneous combustion of combustible dust are studied by calculation and analytical method, depending on such process characteristics as the speed of the dust-air mixture fl ow in the duct, as well as the diameter of the duct’s cross section.Conclusions. The nomograms built on the basis of the studies performed can be used to determine the multiplicity of cleaning of combustible dusts of equipment and air ducts of industrial ventilation systems. The paper provides a calculation of the period of induction of spontaneous combustion of combustible dust deposits using the example of rye fl our with asymmetric heat transfer. Its signifi cance is due to the process of accumulation of deposits of combustible dust to a critical thickness in terms of spontaneous combustion conditions.

scholarly journals Optimal control of stochastic phase-field models related to tumor growth

2020 ◽  
Vol 26 ◽  
pp. 104
Author(s):  
Carlo Orrieri ◽  
Elisabetta Rocca ◽  
Luca Scarpa
Keyword(s):  
Optimal Control ◽  
Tumor Growth ◽  
Phase Field ◽  
Phase Field Model ◽  
Growth Dynamics ◽  
Necessary Optimality Conditions ◽  
Reaction Diffusion ◽  
Adjoint System ◽  
Reaction Diffusion Equation ◽  
Cahn Hilliard Equation

We study a stochastic phase-field model for tumor growth dynamics coupling a stochastic Cahn-Hilliard equation for the tumor phase parameter with a stochastic reaction-diffusion equation governing the nutrient proportion. We prove strong well-posedness of the system in a general framework through monotonicity and stochastic compactness arguments. We introduce then suitable controls representing the concentration of cytotoxic drugs administered in medical treatment and we analyze a related optimal control problem. We derive existence of an optimal strategy and deduce first-order necessary optimality conditions by studying the corresponding linearized system and the backward adjoint system.

scholarly journals Cellular cooperation shapes tumor growth: a statistical mechanics mathematical model

2018 ◽  
Author(s):  
Jeffrey West ◽  
Paul K. Newton
Keyword(s):  
Mathematical Model ◽  
Statistical Mechanics ◽  
Tumor Growth ◽  
Fitness Landscape ◽  
Cellular Level ◽  
Cellular Heterogeneity ◽  
Functional Coupling ◽  
Macroscopic Tumor ◽  
Growth Laws ◽  
Cellular Cooperation

AbstractA tumor is made up of a heterogeneous collection of cell types all competing on a fitness landscape mediated by micro-environmental conditions that dictate their interactions. Despite the fact that much is known about cell signaling and cellular cooperation, the specifics of how the cell-to-cell coupling and the range over which this coupling acts affect the macroscopic tumor growth laws that govern total volume, mass, and carrying capacity remain poorly understood. We develop a statistical mechanics approach that focuses on the total number of possible states each cell can occupy, and show how different assumptions on correlations of these states gives rise to the many different macroscopic tumor growth laws used in the literature. Although it is widely understood that molecular and cellular heterogeneity within a tumor is a driver of growth, here we emphasize that focusing on the functional coupling of these states at the cellular level is what determines macroscopic growth characteristics.Significance statementA mathematical model relating tumor heterogeneity at the cellular level to tumor growth at the macroscopic level is described based on a statistical mechanics framework. The model takes into account the number of accessible states available to each cell as well as their long-range coupling (population cooperation) to other cells. We show that the degree to which cell populations cooperate determine the number of independent cell states, which in turn dictates the macroscopic (volumetric) growth law. It follows that targeting cell-to-cell interactions could be a way of mitigating and controlling tumor growth.

scholarly journals The normalised Sentinel-1 Global Backscatter Model, mapping Earth’s land surface with C-band microwaves

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Bernhard Bauer-Marschallinger ◽  
Senmao Cao ◽  
Claudio Navacchi ◽  
Vahid Freeman ◽  
Felix Reuß ◽  
...  
Keyword(s):  
Land Surface ◽  
Radar Sensors ◽  
Model Mapping ◽  
The Mean ◽  
Noise Correction ◽  
New Perspective ◽  
Orbit Geometry ◽  
Microwave Backscatter ◽  
Global Surface

AbstractWe present a new perspective on Earth’s land surface, providing a normalised microwave backscatter map from spaceborne Synthetic Aperture Radar (SAR) observations. The Sentinel-1 Global Backscatter Model (S1GBM) describes Earth for the period 2016–17 by the mean C-band radar cross section in VV- and VH-polarisation at a 10 m sampling. We processed 0.5 million Sentinel-1 scenes totalling 1.1 PB and performed semi-automatic quality curation and backscatter harmonisation related to orbit geometry effects. The overall mosaic quality excels (the few) existing datasets, with minimised imprinting from orbit discontinuities and successful angle normalisation in large parts of the world. Regions covered by only one or two Sentinel-1 orbits remain challenging, owing to insufficient angular variation and not yet perfect sub-swath thermal noise correction. Supporting the design and verification of upcoming radar sensors, the obtained S1GBM data potentially also serve land cover classification and determination of vegetation and soil states. Here, we demonstrate, as an example of its potential use, the mapping of permanent water bodies and evaluate against the Global Surface Water benchmark.

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