scholarly journals Of mitogens and morphogens: modelling Sonic Hedgehog mechanisms in vertebrate development

2020 ◽  
Vol 375 (1809) ◽  
pp. 20190660 ◽  
Author(s):  
Ian Groves ◽  
Marysia Placzek ◽  
Alexander G. Fletcher
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Sonic Hedgehog ◽  
Mechanism Of Action ◽  
Concentration Gradient ◽  
Experimental Studies ◽  
Theoretical Framework ◽  
Vertebrate Development ◽  
Complex Mechanism ◽  
Proliferation And Differentiation

Sonic Hedgehog (Shh) Is a critical protein in vertebrate development, orchestrating patterning and growth in many developing systems. First described as a classic morphogen that patterns tissues through a spatial concentration gradient, subsequent studies have revealed a more complex mechanism, in which Shh can also regulate proliferation and differentiation. While the mechanism of action of Shh as a morphogen is well understood, it remains less clear how Shh might integrate patterning, proliferation and differentiation in a given tissue, to ultimately direct its morphogenesis. In tandem with experimental studies, mathematical modelling can help gain mechanistic insights into these processes and bridge the gap between Shh-regulated patterning and growth, by integrating these processes into a common theoretical framework. Here, we briefly review the roles of Shh in vertebrate development, focusing on its functions as a morphogen, mitogen and regulator of differentiation. We then discuss the contributions that modelling has made to our understanding of the action of Shh and highlight current challenges in using mathematical models in a quantitative and predictive way. This article is part of a discussion meeting issue ‘Contemporary morphogenesis’.

Factor VIIa: on its own and loving it

Blood ◽  
2012 ◽  
Vol 120 (4) ◽  
pp. 705-707 ◽  
Author(s):  
Dougald M. Monroe
Keyword(s):  
Mathematical Models ◽  
Mechanism Of Action ◽  
Factor Viia ◽  
Experimental Studies ◽  
High Dose ◽  
Dose Factor

In this issue of Blood, Shibeko et al have used a variety of experimental studies and mathematical models to investigate the mechanism of action of high-dose factor VIIa as a bypassing agent in hemophilia.1

scholarly journals MODIFYING MATHEMATICAL MODELS FOR CALCULATING OPERATIONAL CHARACTERISTICS OF DIESEL ENGINES BURNING RME BIOFUELS / MATEMATINIŲ MODELIŲ PRITAIKYMAS DYZELIŲ, DIRBANČIŲ RME BIODEGALAIS, DARBO PROCESUI IR EKSPLOATACINIAMS RODIKLIAMS SKAIČIUOTI / ДОРАБОТКА МАТЕМАТИЧЕСКИХ МОДЕЛЕЙ РАСЧЕТА ПОКАЗАТЕЛЕЙ РАБОТЫ ДИЗЕЛЯ НА БИОДИЗЕЛИНАХ РРМЭ

Transport ◽  
2011 ◽  
Vol 26 (1) ◽  
pp. 50-60 ◽  
Author(s):  
Sergejus Lebedevas ◽  
Galina Lebedeva ◽  
Kristina Bereišienė
Keyword(s):  
Diesel Engine ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Internal Heat ◽  
Computer Programs ◽  
Toxic Substances ◽  
Load Range ◽  
Operational Characteristics

The article considers and solves the problems of adapting the mathematical models, used in calculating operational characteristics of diesel engines burning mineral diesel oil, to engines converted to RME biofuels. The analysis of mathematical models of calculating the main technical and economic characteristics of diesel engines as well as the parameters of the in-cylinder process and the concentration of toxic substances in the exhaust gases is performed. The need for adjusting the calculation algorithms is also demonstrated. The computer programs based on single-zone thermodynamic models are used in the research. The programs of mathematical modelling are modified, i.e. supplemented with the algorithm for calculating energy characteristics of the combustion products (e.g. specific heat capacity, internal heat, the lower calorific value, etc.). Based on the computer programs, modified for examining diesel engines burning biofuels, the computer-aided mathematical modelling experiment is carried out. The results of modelling are compared with the data obtained in testing the diesel engine 1A41. The mathematical modelling performed demonstrates the accuracy acceptable for solving practical problems: the difference between the obtained calculation results and diesel engine testing data for the load range of (1.0÷0.5) Pi nom does not exceed ± 5÷7%. Higher accuracy of modelling the characteristics of diesel engines, operating in the low- and medium-load modes, may be accounted for by the adjustment of the algorithm for calculating the induction period and the on-set phase of fuel injection. Santrauka Publikacijoje pateikti dyzelio darbo proceso ir eksploatacinių rodiklių skaičiavimo matematinių modelių tobulinimo rezultatai, siekiant matematinius modelius pritaikyti dyzeliui dirbant riebiųjų rūgščių metilesterių, taip pat RME, biodegalais. Atlikta skaičiavimo algoritmų analizė ir pagrįsti pagrindiniai jų tobulinimo aspektai. Sukurtas kompiuterinis programinis modelis, skirtas darbinio kūno dyzelio cilindre energiniams parametrams skaičiuoti (specifinei šilumai, vidinei energijai), dyzeliui dirbant plačiąja elementinės cheminės sudėties biodegalų gama. Atliktas 1A41 dyzelio techninių ir ekonominių bei ekologinių rodiklių modeliavimas kompiuteriu, naudojant patobulintus matematinius modelius. Parodytas gautų rezultatų, pakankamų praktiniams uždaviniams spręsti, tikslumas: dyzeliui dirbant artimos nominaliosios apkrovos režimais (1,0÷0,5) Pi nom skirtumas tarp skaičiavimo ir dyzelio motorinių tyrimų rezultatų neviršija ±5÷7%. Dyzeliui dirbant mažos apkrovos režimu, matematinio modeliavimo rezultatų adekvatumo didinimas susijęs su kuro įpurškimo fazės bei savaiminio užsiliepsnojimo indukcijos periodo skaičiavimo algoritmo tobulinimu. Резюме Рассмотрены и решены задачи адаптации математических моделей расчета показателей дизеля при переводе их работы с минерального дизелина на биодизелины метилового эфира рапсового масла (МЭРМ). Выполнен анализ и дано обоснование направлений доработки расчетных алгоритмов ряда однозонных термодинамических математических моделей, используемых в практике исследования эксплуатационных показателей, параметров индикаторного процесса и эмиссии токсичных компонентов в выхлопных газах дизелей. В форме программного модуля составлен алгоритм расчета энергетических параметров рабочего тела в цилиндре (удельной теплоемкости, теплоты сгорания, внутренней энергии) для топлив с широким элементарным химическим составом. С использованием доработанных компьютерных программ выполнен широкий расчетный эксперимент и сопоставлены его результаты с данными моторных стендовых испытаний одноцилиндрового отсека дизеля 1А41. Показана приемлемая для решения практических задач точность математического моделирования: для нагрузочных режимов (1÷0,5) Pmi расхождения расчетных и экспериментальных значений параметров работы дизеля не превышают ±5÷7%. Повышение качества моделирования показателей дизеля на режимах средних и малых нагрузок связано с уточнением алгоритма расчета периода индукции и фазы начала видимого горения топлива в цилиндре.

Mathematical modelling.

2021 ◽  
Author(s):  
Ed Rutgers Durner
Keyword(s):  
Mathematical Model ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Growth And Development ◽  
Fertilizer Recommendations ◽  
Mathematical Equations

Abstract Plants are studied to understand their growth and development so that their quality and productivity can be optimised. Models are developed that can be simple and descriptive, or quite complex with numerous mathematical equations; their level of complexity is linked to their purpose. This summary serves as an introduction to mathematical models in horticulture. It is not a manual for modelling itself, but rather an overview of how important mathematical models are in horticultural production. Mathematical models are used extensively in horticulture both extrinsically, i.e. when calculating chilling hour accumulations and intrinsically, i.e. when applying fertilizer to a crop. In chilling calculations, developed models are used directly. Fertilizer recommendations were probably developed using a mathematical model. The first part of this article discusses models in general and reviews general characteristics of mathematical models. The second part outlines the major uses of mathematical modelling in modern horticultural production. Presentations of specific models are limited in order to present a general discussion of models with examples that will interest most horticulturists.

scholarly journals Air Temperature Control System in a Building on the Basis of Mathematical Modelling

2018 ◽  
Vol 155 ◽  
pp. 01041 ◽  
Author(s):  
Aleksandr Pilipenko ◽  
Sergei Petrov
Keyword(s):  
Computer Simulation ◽  
Control System ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Air Temperature ◽  
Temperature Control ◽  
Automated System ◽  
Temperature Control System ◽  
Heating Systems ◽  
The Cost

In the article the authors solve a crucial objective of reducing the cost of heating services through the introduction of a system, controlling boilers and heating devices, based on modelling of the building and predicting heating systems functioning and operation. The authors describe the method of mathematical modelling of heating systems of the building and represent the developed mathematical models, pledged and installed into the developed automated system. The authors have offered an automated system of dispatch control of the boilers with the elements of computer simulation and modelling.

scholarly journals AUTOMATED MODELING AND FORECASTING SYSTEM OF ENTERPRISE ACTIVITIES

2021 ◽  
Vol 23 ◽  
pp. 20-26
Author(s):  
A. Khariv ◽  
A. Lagun
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Computer Technology ◽  
Rapid Development ◽  
Computing Methods ◽  
Automated System ◽  
Enterprise Management ◽  
Mathematical Methods ◽  
The Future ◽  
Modelling And Forecasting

Introduction. Mathematical methods and models are an effective tool for studying complex economic systems at different levels of enterprise management. Economic mathematical modelling is actively developing not only as a scien-tific field but also as a means of substantiating management decisions in business, in the analysis and forecasting of socio-economic processes and phenomena. In the arsenal of economic and mathematical modelling now are using- modern computing methods and computer technology. Libraries of economic and mathematical models are an integral part of the architecture of decision support systems in specific areas of the economy. The rapid development of computer technology stimulates the emergence and formation of new theoretical volumes and applied areas of modelling.Purpose. Like any large and complex field of knowledge, mathematical modelling is evolving in different direc-tions, acquiring new flexible research methods. Therefore, based on new hardware, technology and software platforms it is necessary to create new information systems using economic and mathematical models in particular for forecasting of enterprise activities.Results. The article analyses the methods of modelling and forecasting the enterprise, considers the principles of software design. Using systems analysis, the design problem was analytically divided into parts. Also were investigated the connections and relationships between these parts, in particular, were implemented the problem tree and the goal tree. Implemented business process modelling performs based on created structural-logical diagrams, namely the IDEF0 dia-gram, which helps to visually display data and information that affect software development, a server part, input data and users. Using the results of research, the authors developed an automated information system for modelling and forecasting the activities of the enterprise, which uses models of Holt, Brown, exponential smoothing and Box-Jenkins for modelling. Part of the developed system is a designed software product that implements the objectives of the research. The obtained program results allow creating a clear forecast of the future activities of the enterprise.Conclusions. Based on the built graphs of modelling and forecasting of the Cisco Systems company financial activity with using of the developed automated system, we established that the Brown model is the best for providing educational sampling and a forecast of activity. The development of the automated system in the future involves the expansion of functionality, improvement and increasing of quality, as well as the creation of powerful analytics for more detailed forecasting.

scholarly journals MATHEMATICAL MODELLING AND STATISTICAL ANALYSIS IN POST - COVID-19 TOURISM RECOVERY

2021 ◽  
Author(s):  
Marija Paunovic ◽  
Keyword(s):  
Statistical Analysis ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Mitigation Measures ◽  
Impact Factors ◽  
Widespread Application ◽  
Recovery Programs ◽  
Tourism Sector ◽  
Travel Restrictions

The COVID-19 pandemic, along with responses to pandemic control in the form of a national blockade with widespread application of travel restrictions, has made tourism one of the most vulnerable sectors. With increasing mitigation measures in many countries regarding tourism and travel restrictions in some segments, different tourism recovery programs are being launched according to the specifics of each country. The paper will consider various proposed measures through different impact factors set in order to accelerate the recovery of the tourism sector. Selected mathematical models will be presented and discussed.

scholarly journals Learning Mathematics Through Mathematical Modelling Processes Within Sports Day Activity

2020 ◽  
Vol 10 (2) ◽  
pp. 105-114
Author(s):  
Sakon Tangkawsakul ◽  
Nuttapat Mookda ◽  
Weerawat Thaikam
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Mathematics Teachers ◽  
Mathematical Knowledge ◽  
Real Life ◽  
Knowledge And Skills ◽  
School Sports ◽  
Learning Mathematics ◽  
The One ◽  
Modelling Task

In this study, we adapted the school sports day to provide opportunities to relate real-life situations with mathematical knowledge and skills. The purpose of this study was to describe the way that the teachers interact with their students and the students’ responses during mathematical modelling processes. The designing of the modelling task was inspired by the Realistic Fermi Problems about the bleacher in the school sports day. The modelling task was designed by a collaboration of mathematics teachers and educators and experimented with 10th-grade students. Each experiment lasted for 45 minutes and was conducted in the one-day camp with 45 students. The results showed that the students who had no previous experience of mathematical modelling engaged in mathematical modelling processes with their friends under the guidance and supporting of the teacher. Most of them were able to think, make assumptions, collect data, observe, make conjectures and create mathematical models to understand and solve the modelling task.   

scholarly journals Mathematical Modelling and Prediction in Infectious Disease Epidemiology

2019 ◽  
Vol 23 (3) ◽  
pp. 328-334
Author(s):  
E. Ya. Yanchevskaya ◽  
O. A. Mesnyankina
Keyword(s):  
Mathematical Modeling ◽  
Infectious Disease ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Modern World ◽  
Urgent Problem ◽  
Stages Of Development ◽  
Historical Aspects ◽  
Disease Epidemiology ◽  
Infectious Disease Epidemiology

Mathematical modeling of diseases is an urgent problem in the modern world. More and more researchers are turning to mathematical models to predict a particular disease, as they help the most correct and accurate study of changes in certain processes occurring in society. Mathematical modeling is indispensable in certain areas of medicine, where real experiments are impossible or difficult, for example, in epidemiology. The article is devoted to the historical aspects of studying the possibilities of mathematical modeling in medicine. The review demonstrates the main stages of development, achievements and prospects of this direction.

scholarly journals Categories as Mathematical Models

2018 ◽  
Author(s):  
David I. Spivak
Keyword(s):  
Dynamical Systems ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Category Theory ◽  
Vector Spaces ◽  
Mathematical Objects ◽  
Working Definition ◽  
Modelling Framework ◽  
Categorical Models ◽  
Definition Of

Category theory is presented as a mathematical modelling framework that highlights the relationships between objects, rather than the objects in themselves. A working definition of model is given, and several examples of mathematical objects, such as vector spaces, groups, and dynamical systems, are considered as categorical models.

scholarly journals Discovery of a Novel Non-Narcotic Analgesic Derived from the CL-20 Explosive: Synthesis, Pharmacology and Target Identification of Thio-wurtzine, a Potent Inhibitor of the Opioid Receptors and the Voltage-Dependent Calcium Channels

2021 ◽  
Author(s):  
Stephanie Aguero ◽  
Simon Megy ◽  
Raphael Terreux ◽  
Mailys Fournier ◽  
Daria Kulagina ◽  
...  
Keyword(s):  
Calcium Channels ◽  
Opioid Receptors ◽  
Mechanism Of Action ◽  
Pain Treatment ◽  
Target Identification ◽  
Animal Experiments ◽  
Complex Mechanism ◽  
Narcotic Analgesics ◽  
Voltage Dependent

The number of candidate molecules for new non-narcotic analgesics is extremely limited. Here we report the identification of thiowurtzine, a new potent analgesic molecule with promising application in chronic pain treatment. We describe the chemical synthesis of this unique compound derived from the hexaazaisowurtzitane (CL-20) explosive molecule. Then we use animal experiments to assess its analgesic activity in vivo upon chemical, thermal and mechanical exposures, compared to the effect of several reference drugs. Finally, we investigate the potential receptors of thiowurtzine in order to better understand its complex mechanism of action. We use docking, molecular modeling and molecular dynamics simula-tions to identify and characterize the potential targets of the drug and confirm the results of the animal experiments. Our findings finally indicate that thiowurtzine may have a complex mechanism of action, by targeting the mu, kappa, delta and ORL1 opioid receptors, and the voltage-gated calcium channels as well.

Sign in / Sign up

Export Citation Format

Share Document