scholarly journals Interkinetic nuclear movements promote apical expansion in pseudostratified epithelia at the expense of apicobasal elongation

2019 ◽  
Author(s):  
Marina A. Ferreira ◽  
Evangeline Despin-Guitard ◽  
Fernando Duarte ◽  
Pierre Degond ◽  
Eric Theveneau
Keyword(s):  
Mathematical Model ◽  
Tissue Expansion ◽  
Tissue Growth ◽  
Common Type ◽  
Congenital Diseases ◽  
Agent Based ◽  
Apical Domain ◽  
Cell Processes ◽  
Specific Elongation ◽  
Cytoskeleton Dynamics

AbstractPseudostratified epithelia (PSE) are a common type of columnar epithelia found in a wealth of embryonic and adult tissues such as ectodermal placodes, the trachea, the ureter, the gut and the neuroepithelium. PSE are characterized by the choreographed displacement of cells’ nuclei along the apicobasal axis according to phases of their cell cycle. Such movements, called interkinetic movements (INM) have been proposed to influence tissue expansion and shape and suggested as culprit in several congenital diseases such as CAKUT and esophageal atresia. INM rely on cytoskeleton dynamics just as adhesion, contractility and mitosis do. Therefore, longer term impairment of INM without affecting proliferation and adhesion is currently technically unachievable. Here we bypassed this hurdle by generating a 2D agent-based model of a proliferating PSE and compared its output to the growth of the chick neuroepithelium to assess the interplay between INM and these other important cell processes during growth of a PSE. We found that INM directly generates apical expansion and apical nuclear crowding. In addition, our data strongly suggest that apicobasal elongation of cells is not an emerging property of a proliferative PSE but rather requires a specific elongation program. We then discuss how such program might functionally link INM, tissue growth and differentiation.Authors SummaryPseudostratified epithelia (PSE) are a common type of epithelia characterized by the choreographed displacement of cells’ nuclei along the apicobasal axis during proliferation. These so-called interkinetic movements (INM) were proposed to influence tissue expansion and suggested as culprit in several congenital diseases. INM rely on cytoskeleton dynamics. Therefore, longer term impairment of INM without affecting proliferation and adhesion is currently technically unachievable. We bypassed this hurdle by generating a mathematical model of PSE and compared it to the growth of an epithelium of reference. Our data show that INM drive expansion of the apical domain of the epithelium and suggest that apicobasal elongation of cells is not an emerging property of a proliferative PSE but might rather requires a specific elongation program.

scholarly journals Mathematical Model of Muscle Wasting in Cancer Cachexia

2020 ◽  
Author(s):  
Suzan Farhang-Sardroodi ◽  
Kathleen P. Wilkie
Keyword(s):  
Mathematical Model ◽  
Satellite Cell ◽  
Muscle Tissue ◽  
Cancer Cachexia ◽  
Muscle Wasting ◽  
Tissue Growth ◽  
Colon 26 ◽  
Treatment Conditions ◽  
Risk Of Mortality ◽  
Pharmacological Blockade

Cancer cachexia is a debilitating condition characterized by an extreme loss of skeletal muscle mass which negatively impacts patient’s quality of life, reduces their ability to sustain anticancer therapies, and increases the risk of mortality. Recent discoveries have identified the myostatin/activin-ActRIIB pathway as critical to muscle wasting by inducing satellite cell quiescence and increasing muscle-specific ubiquitin ligases responsible for atrophy. Remarkably, pharmacological blockade of the ActRIIB pathway has shown to reverse muscle wasting and prolong the survival time of tumor-bearing animals. To explore the implications of this signaling pathway and potential therapeutic targets in cachexia, we construct a novel mathematical model of muscle tissue subjected to tumor-derived cachexic factors. The model formulation tracks the intercellular interactions between cancer, satellite cell, and muscle cell populations. The model is parameterized by fitting to colon-26 mouse model data, and analysis provides insight into tissue growth in healthy, cancerous, and post-treatment conditions. Model predictions suggest that cachexia fundamentally alters muscle tissue health, as measured by the stem cell ratio, and this is only partially recovered by anti-cachexia treatment. Our mathematical findings suggest that the activation and proliferation of satellite cells, after blocking the myostatin/activin B pathway, is required to partially recover cancer-induced muscle loss.

scholarly journals Reflection of documents in the digital twin of the company and calculation of their impact on human behavior in the simulation model

E-Management ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 50-60
Author(s):  
M. V. Samosudov
Keyword(s):  
Mathematical Model ◽  
Social System ◽  
Social Systems ◽  
Control Effect ◽  
Economic Space ◽  
Agent Based ◽  
Digital Twin ◽  
The Social ◽  
The Impact ◽  
System Operating

The formation and formation of the Industry 4.0 concept stimulated the discussion of the use of computer technology in various areas of economic activity and, in particular, in the automation of social systems management. The basis of the concept is the inclusion of a virtual image of the social system in the form of a mathematical model or a digital twin of the enterprise in the production and management system. At the same time, it should be noted that today digital twin are created mainly only for technical objects used in the activities of enterprises. The purpose of the article is to demonstrate the possibility of fixing organizational documents as one of the system-forming factors in the digital twin of an enterprise. This circumstance makes it possible, firstly, to more accurately calculate the managerial effects of managers by taking into account the impact of organizational documents on the activities of employees of the enterprise; secondly, to identify conflicts of documents developed by various departments of the company; thirdly, to calculate the content of documents during their development (design), based on the requirements of the situation or a given control effect. This possibility arises due to the use of a comprehensive mathematical model of the social system operating in an active environment. The model is a simulation agent-based model and allows you to calculate the dynamics of the social system in the socio-economic space, which allows its use in decision support systems by managers of any scale and activities to calculate the expected effect of management decisions – the specifics of a particular social system are taken into account by combining the values of the phase variables describing the state of the enterprise. The novelty of the research paper lies in the fact that it shows: the possibility to calculate the influence of organizational documents on the behavior of participants and, consequently, on the result of the social system, as well as the mechanism for converting messages, which are invariants of socio-economic space into information that affects the behavior of participants of relations.

scholarly journals Mathematical Model of Muscle Wasting in Cancer Cachexia

2020 ◽  
Vol 9 (7) ◽  
pp. 2029 ◽  
Author(s):  
Suzan Farhang-Sardroodi ◽  
Kathleen P. Wilkie
Keyword(s):  
Mathematical Model ◽  
Satellite Cell ◽  
Muscle Tissue ◽  
Cancer Cachexia ◽  
Muscle Wasting ◽  
Functional Differentiation ◽  
Activin A ◽  
Tissue Growth ◽  
Partial Recovery ◽  
Colon 26

Cancer cachexia is a debilitating condition characterized by an extreme loss of skeletal muscle mass, which negatively impacts patients’ quality of life, reduces their ability to sustain anti-cancer therapies, and increases the risk of mortality. Recent discoveries have identified the myostatin/activin A/ActRIIB pathway as critical to muscle wasting by inducing satellite cell quiescence and increasing muscle-specific ubiquitin ligases responsible for atrophy. Remarkably, pharmacological blockade of the ActRIIB pathway has been shown to reverse muscle wasting and prolong the survival time of tumor-bearing animals. To explore the implications of this signaling pathway and potential therapeutic targets in cachexia, we construct a novel mathematical model of muscle tissue subjected to tumor-derived cachectic factors. The model formulation tracks the intercellular interactions between cancer cell, satellite cell, and muscle cell populations. The model is parameterized by fitting to colon-26 mouse model data, and the analysis provides insight into tissue growth in healthy, cancerous, and post-cachexia treatment conditions. Model predictions suggest that cachexia fundamentally alters muscle tissue health, as measured by the stem cell ratio, and this is only partially recovered by anti-cachexia treatment. Our mathematical findings suggest that after blocking the myostatin/activin A pathway, partial recovery of cancer-induced muscle loss requires the activation and proliferation of the satellite cell compartment with a functional differentiation program.

Instability and Mitotic Patterns in Tissue Growth

1973 ◽  
Vol 95 (3) ◽  
pp. 324-327 ◽  
Author(s):  
Leon Glass
Keyword(s):  
Mathematical Model ◽  
Tumor Growth ◽  
Mitotic Activity ◽  
Model System ◽  
Tissue Growth ◽  
Dimensionless Number

A mathematical model which reproduces several qualitative features of cancerous tumor growth is proposed. The onset of unstable growth is characterized by a dimensionless number, which is defined in terms of the parameters describing the system. Patterns of mitotic activity of the model system are compared with experimentally observed patterns of mitotic activity in cancerous tissues.

DIVERSITY AND KNOWLEDGE SHARING IN CONSTRUCTION: A MATHEMATICAL MODEL

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Daoud Kiomjian ◽  
F. Jordan Srour ◽  
Issam Srour
Keyword(s):  
Mathematical Model ◽  
Knowledge Sharing ◽  
Five Dimensions ◽  
Agent Based ◽  
Language And Education ◽  
And Performance ◽  
Demographic Attributes ◽  
Future Work ◽  
The Impact ◽  
The Mathematical Model

Conventional wisdom in the management literature holds that diversity is positively correlated with performance. Yet, the findings from the construction field indicate that this is not always the case. In an effort to study the interaction between diversity and performance in the construction industry, this paper presents the elements of a theoretical mathematical model to explore the relationship between diversity and knowledge sharing which is a precursor of performance. This model includes five dimensions of diversity: ethnicity, age, experience, language and education. At the heart of the mathematical model is a fuzzy based system that generates the probability of knowledge sharing among members with different demographic attributes. The presented fuzzy system will, in future work, become the foundation of an agent based model used to study the impact of worker interactions on productivity.

Modeling hairy root tissue growth in in vitro environments using an agent-based, structured growth model

2013 ◽  
Vol 37 (6) ◽  
pp. 1173-1184 ◽  
Author(s):  
Felix Lenk ◽  
Almuth Sürmann ◽  
Patrick Oberthür ◽  
Mandy Schneider ◽  
Juliane Steingroewer ◽  
...  
Keyword(s):  
Growth Model ◽  
Hairy Root ◽  
Tissue Growth ◽  
Root Tissue ◽  
Agent Based

Exploring Theories of Victimization Using a Mathematical Model of Burglary

2011 ◽  
Vol 48 (1) ◽  
pp. 83-109 ◽  
Author(s):  
Ashley B. Pitcher ◽  
Shane D. Johnson
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Qualitative Agreement ◽  
The Other ◽  
Residential Burglary ◽  
Foraging Activity ◽  
Good Qualitative Agreement ◽  
Agent Based ◽  
Stable Variation ◽  
Near Repeat

Research concerned with burglary indicates that it is clustered not only at places but also in time. Some homes are victimized repeatedly, and the risk to neighbors of victimized homes is temporarily elevated. The latter type of burglary is referred to as a near repeat. Two theories have been proposed to explain observed patterns. The boost hypothesis states that risk is elevated following an event reflecting offender foraging activity. The flag hypothesis, on the other hand, suggests that time-stable variation in risk provides an explanation where data for populations with different risks are analyzed in the aggregate. To examine this, the authors specify a series of discrete mathematical models of urban residential burglary and examine their outcomes using stochastic agent-based simulations. Results suggest that variation in risk alone cannot explain patterns of exact and near repeats, but that models which also include a boost component show good qualitative agreement with published findings.

scholarly journals An Integrated Mathematical Model of Microbial Fuel Cell Processes: Bioelectrochemical and Microbiologic Aspects

Processes ◽  
2017 ◽  
Vol 5 (4) ◽  
pp. 73 ◽  
Author(s):  
Andrea Capodaglio ◽  
Daniele Cecconet ◽  
Daniele Molognoni
Keyword(s):  
Mathematical Model ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Cell Processes

scholarly journals Modeling the Disorder of Closed System by Multi-Agent Based Simulation

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1105 ◽  
Author(s):  
Krzysztof Małecki ◽  
Tomasz M. Gwizdałła ◽  
Paweł Bieńko
Keyword(s):  
Mathematical Model ◽  
Decision Making ◽  
Computer Simulation ◽  
Real Life ◽  
Medical Sciences ◽  
Agent Based Simulation ◽  
Agent Based ◽  
Engineering Aspect ◽  
Multi Agent ◽  
The Cost

Mess (disorder)—there are many different meanings related to this problem. The explicit majority comes from the area of philosophical, social and medical sciences. In our paper, we try to present the engineering aspect of the concept of disorder. We propose a mathematical model which describes the effects and consequences concerning the process of making the mess. We use Multi-Agent Modeling, where there are several independent agents with decision-making ability. Each agent has the ability to communicate and perceive for achieving its own aim. We use square grid n × n with objects which can be moved by agents to another places. The degree of disorder of the system is examined by the value of entropy. Using computer simulation, we investigate the time needed to find the desired thing in an environment in which agents (in real life, people) co-exist and they have different tendencies to tidiness. The cost of mess is counted as the number of attempts to access the object in the analyzed system and the time needed to locate the object.

scholarly journals Rapid Recruitment of Symbiotic Algae into Developing Scleractinian Coral Tissues

2019 ◽  
Vol 7 (9) ◽  
pp. 306
Author(s):  
Bockel ◽  
Rinkevich
Keyword(s):  
Tissue Expansion ◽  
Outer Edge ◽  
Tissue Growth ◽  
Coral Tissue ◽  
Coral Host ◽  
Pocillopora Damicornis ◽  
Stylophora Pistillata ◽  
Symbiotic Algae ◽  
Glass Slides ◽  
Host Tissues

While the early acquisition of Symbiodiniaceae algae into coral host tissues has been extensively studied, the dynamics of the migration of algal cells into rapidly expanding coral tissues still lacks a systematic study. This work examined two Red Sea branching coral species, Pocillopora damicornis and Stylophora pistillata, as they were growing and expanding their tissue laterally on glass slides (January–June, 2014; 450 assays; five colonies/species). We measured lateral tissue expansion rates and intratissue dinoflagellate migration rates. Tissue growth rates significantly differed between the two species (with Stylophora faster than Pocillopora), but not between genotypes within a species. Using a “flow-through coral chamber” under the microscope, the migration of dinoflagellates towards the peripheral edges of the expanding coral tissue was quantified. On a five-day timescale, the density of the endosymbiotic dinoflagellate cells, presenting within a 90 µm region of expanding coral tissue (outer edge), increased by a factor of 23.6 for Pocillopora (from 1.2 × 104 cells cm‒² to 2.4 × 105 cells cm‒²) and by a factor of 6.8 for Stylophora (from 3.6 × 104 cells cm‒² to 2.4 × 105 cells cm‒²). The infection rates were fast (5.2 × 104 and 4.1 × 104 algal cells day-1 cm‒², respectively), further providing evidence of an as yet unknown pathway of algal movement within coral host tissues.

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