Featured Author

John Hayward

I am a Visiting Research Fellow in Mathematics at the University of South Wales. Before my retirement, I was a senior lecturer at the university, teaching specialist courses in system dynamics, mathematical modelling and agent-based methods. I was awarded a BSc in astrophysics, and a PhD in applied mathematics, from the University of London, and then spent my career as a lecturer in mathematics. My research is in mathematical sociology with applications to the spread of social phenomena, such as ... Read more

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We found 40 items
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#1

Cellular Respiration Accounting Model

The purpose of the model is to understand how glucose is metabolized, and how the energy stored in i ... Read more
The purpose of the model is to understand how glucose is metabolized, and how the energy stored in its chemical bonds is transfered.
sim839,721 runs
cellular respiration aerobic respiration ATP biology
814826.2
#2

Enzyme Diversity

sim550,472 runs
enzyme biology substrate pepsin indicators
739463.2
#3

Lactase with Variable Sample Sizes

Arrayed Lactase Model
sim976,233 runs
Lactase array sample size biology
587883.4
#4

Information Processing and Neurophysiology Model

The main dependent variable measured in the model is the membrane potential (millivolts) of two diff ... Read more
The main dependent variable measured in the model is the membrane potential (millivolts) of two different neurons in a series. You will be able to add excitatory and inhibitory neurotransmitters, and compare how these modulate electrical impulses of the two neurons. Additionally, you will be able to compare the effects of three neurotoxins: Tetrodotoxin, botulinum toxin, and sarin nerve gas. While extremely lethal, these toxins are very instructive in understanding neurons because of the specific way the toxins act. Each toxin modifies or inhibits a specific molecule in neurons that help process and transmit information.
sim390,658 runs
infromation processing neurophysiology biology
453955.44
#5

COVID-19 Simulator

This simulator looks at the spread of COVID-19 (Coronavirus) through a city. You can implement poli ... Read more
This simulator looks at the spread of COVID-19 (Coronavirus) through a city. You can implement policies, change assumptions about the disease and see the impacts in realtime.
sim133,646 runs
Biology Science Education COVID-19 Coronavirus
295806.3
#6

Evolution of Antibiotic Resistance Simulation

Evolution of Antibiotic Resistance Simulation. This model tracks the accumulation of 40 colonies of ... Read more
Evolution of Antibiotic Resistance Simulation. This model tracks the accumulation of 40 colonies of bacteria. The main purpose of the model is to show that new adaptations are not caused by an environmental factor, like antibiotics. Rather, new adaptations are the selection of available variations. In this model you can increase variations by increasing the UV dose. The UV dose increases the mutation rate with a Monte Carlo function.
sim270,612 runs
Biology Science Ecology Education
211153.06
#7

Lactose Operon: An Inducible System

In this simulation users explore the negative feedback system of the Lactose Operon found in bacteri ... Read more
In this simulation users explore the negative feedback system of the Lactose Operon found in bacteria. Lactose induces the system by inhibiting and inhibitor.
sim159,976 runs
Inhibition negative feedback biology lactose operon
169403.22
#8

Limiting Nutrients in Aquatic Ecosystems

Experiment with a variety of nutrients that are limited by different degrees in four different ecosy ... Read more
Experiment with a variety of nutrients that are limited by different degrees in four different ecosystems.
sim158,009 runs
limiting nutrients ecosystem biology logistic growth
141999.88
#9

Transformation Simulation

Simulation allows students to test the transformation principle. Two major goals of the experiment a ... Read more
Simulation allows students to test the transformation principle. Two major goals of the experiment are: 1. Allow users to see that supernatant from heat-killed bacteria can transform the genes of another bacterium. 2. What transforms the inheritance of the bacteria is DNA, not RNA or proteins.
sim150,904 runs
transformation DNA biology
109729.13
#10

Cellular Respiration Inquiry

Model of the dynamics of the metabolism of one mole of glucose. Randomness is built into the computa ... Read more
Model of the dynamics of the metabolism of one mole of glucose. Randomness is built into the computations.
sim129,663 runs
metabolism respriation ATP biology
89551.28
#11

Guppy Evolution

sim217,764 runs
evolution biology genes
86349.36
#12

Thyroid Hormone - Negative Feedback

sim92,498 runs
negative feedback thyroid hormone metabolism biology
79402.14
#13

The dynamics of photosynthesis - variable sample size

The dynamics of photosynthesis - variable sample size
sim95,176 runs
photosynthesis sample size biology
65991.375
#14

Genotyping with Electrophoresis

sim50,297 runs
biology inheritance DNA restriction enzyme
38798.375
#15

Transformation Experiment with Controls

Simulation allows users to test the bacterial transformation principle discovered by Frederick Griff ... Read more
Simulation allows users to test the bacterial transformation principle discovered by Frederick Griffith.
sim32,476 runs
Biology Science Education transformation DNA
37834.348
#16

SIR COVID-19 Coronavirus Simulation

sim21,640 runs
Environment Biology Science Education SIR
28623.08
#17

Cell Cycle - Simpler 2020

sim66,918 runs
Biology Science Education
28445.02
#18

Neurophysiology and Information Processing 2022

sim23,660 runs
Biology information processing neuron neurotransmission neurophysiology
25742.98
#19

Phenology of the Karner Blue Butterfly

Karner Blue butterfly is an endangered species. Habitat loss and climate change are contributing fac ... Read more
Karner Blue butterfly is an endangered species. Habitat loss and climate change are contributing factors to the reduction in the butterflies' population sizes. Climate change can alter the timing of lifecycles. When climate change disproportionally affects the timing of life cycles of species in an ecosystem asynchrony within a food web occurs.
sim14,802 runs
asynchrony timing phenology climate change butterfly
21939.643
#20

COVID-19 Model

This simulator walks the user through a model showing the spread of the COVID, or Corona Virus throu ... Read more
This simulator walks the user through a model showing the spread of the COVID, or Corona Virus through a city. You can implement policies, change assumptions about the disease and see the impacts in realtime.
model16,824 downloads
Download Model
Biology Science Education COVID-19 Corona Virus
20819.307
#21

HPV with Influenza A Humoral Immunity

Immune response of HPV
sim30,002 runs
HPV antibodies biology Immunity
18466.504
#22

Route21

Administration routes
sim70,532 runs
Biology Science Education pharmacokinetics simulation
17955.232
#23

Surface Area per Volume Simulation

As you delve into the simulation, you will have the opportunity to manipulate different aspects of t ... Read more
As you delve into the simulation, you will have the opportunity to manipulate different aspects of the cellular structure: ΔSide Simulation: Here, you can adjust the lengths of the sides of a cube, directly influencing the surface area and volume of the cell. ΔVolume Simulation: In this scenario, you can modify the volume of a rectangular solid while keeping the surface area constant, showcasing how changes in volume impact diffusion. ΔSurface Area Simulation: Finally, you can alter the surface area of the rectangular solid while maintaining a constant volume, shedding light on the impact of surface area changes on diffusion rates.
sim17,458 runs
Environment Biology Science Education cell
14854.06
#24

H1N1 Flu Outbreak

What is most effective in controlling the outbreak of a flu virus in schools? Is it better to vaccin ... Read more
What is most effective in controlling the outbreak of a flu virus in schools? Is it better to vaccinate or stay home? Use this Learning Lab to understand how infectious disease spreads and why the World Health Organization signaled the 2009 H1N1 (also called “swine flu”) outbreak as a pandemic.
sim6,847 runs, 409 downloads
Download Model
Environment Biology Education Flu outbreak
12720.628
#25

Carbon Cycle Simulation

Simulation tracks the movement of carbon to and from the atmosphere in Gt C (and Gt CO2). Users can ... Read more
Simulation tracks the movement of carbon to and from the atmosphere in Gt C (and Gt CO2). Users can manipulate with graphical inputs the changes in fossil fuel emissions, land-use, and ocean sinks.
sim12,756 runs
Environment Biology Science Ecology Education
11845.566
#26

Dosing regimen for renal failure

Dosing regimen for renal failure
sim28,392 runs
Biology Science Education pharmacokinetics simulation
11675.799
#27

Evolution: Grants Finches

Models the effects on population sizes of ground finches with different beak sizes in response to di ... Read more
Models the effects on population sizes of ground finches with different beak sizes in response to different amounts of annual precipitation.
sim13,597 runs
evolution biology natural selection
10058.2
#28

FermOpt: the fermentation optimisation game

A semi-batch fermenter simulation, in which players must explore the effects of various operating pa ... Read more
A semi-batch fermenter simulation, in which players must explore the effects of various operating parameters to try to maximise the production of an imaginary product, "WonderMab", for the lowest possible cost.
sim3,828 runs
Biology Science Education fermenter fermentor
9822.613
#29

The Infection Simulation

Based on a kinesthetic game in "The Shape of Change," this simple simulation allows exploration of d ... Read more
Based on a kinesthetic game in "The Shape of Change," this simple simulation allows exploration of different scenarios for spread of an infection. Other similar contexts are also described, e.g., spread of ideas, rumors, and kindness.
sim8,096 runs, 8 downloads
Download Model
Biology Science Education infection disease
8296.597
#30

interval

dosing interval
sim22,239 runs
Biology Science Education pharmacokinetics simulation
6417.2085
#31

Thinking About Drinking

What happens WHEN someone you know drinks? That depends, on the amount of alcohol consumed, the time ... Read more
What happens WHEN someone you know drinks? That depends, on the amount of alcohol consumed, the timeframe, along with a number of personal characteristics. Indeed, the level of alcohol which builds up in a person's bloodstream can vary enormously.
sim4,398 runs, 60 downloads
Download Model
Biology Science Education alcohol teen drinking
6277.052
#32

COVID-19: Vertical Isolation in Brazil

Does the policy of vertical isolation allow a country to reopen its businesses and schools without i ... Read more
Does the policy of vertical isolation allow a country to reopen its businesses and schools without increasing COVID-19 cases or deaths? This simulator explores the outcomes of horizontal isolation (what we're doing now) and vertical isolation (only isolate the sick and the elderly).
sim4,598 runs
Biology Science Education COVID-19 coronavirus
5790.904
#33

COVID-19: Vaccinations in the USA

This model explores the vaccination program in the United States and its effort to control the COVID ... Read more
This model explores the vaccination program in the United States and its effort to control the COVID-19 pandemic. It includes vaccine hesitancy, people's behavior in response to perceived risk, and vaccine effectiveness.
sim3,909 runs
Biology Science Education COVID-19 Coronavirus
5456.5757
#34

COVID-19 Model By Age

This models the COVID-19 pandemic as an SEIR model disaggregated by age. DIfferent ages have differ ... Read more
This models the COVID-19 pandemic as an SEIR model disaggregated by age. DIfferent ages have different contact rates, death rates, and conformance to social distancing. A thrid-order material delay is used to create the distribution for the tie to become infected and the time to recover.
model4,486 downloads
Download Model
Biology Science Education COVID-19 Coronavirus
5118.6333
#35

Covid19-Epidemie-ModelEducationBase1B

This model was copied from Gigaroff: 1. French (in English in 2.) Modèles pour mieux comprendre la ... Read more
This model was copied from Gigaroff: 1. French (in English in 2.) Modèles pour mieux comprendre la dynamique d'une épidémie et comment les mesures prises permettent d'en atténuer les effets" - Projet interdisciplines Hervé Gigaroff, Lycée "Emile Combes" de Pons 17 (France)-
 • Ceci est le Modèle de base “1.B” pour commencer à mieux comprendre la dynamique d'une épidémie, type CoVid 19, , simplifiée mais tout à fait réaliste… …Avant de voir, avec des modèles suivants, comment les mesures prises permettent d'en atténuer les effets" Pour les “matheux”, fans d’équations différentielles, ce modèle n’est jamais que la mis en forme, selon les lois de le “SYSTÉMIQUE DYNAMIQUE” de ce qui est représenté , en équations différentielles dans cette excellente vidéo: https://www.youtube.com/watch?v=-2tI3MQFqkI&fbclid=IwAR3QdfrTCQPKNUogozNchAlpu0SwTlvQx_fPNaTDjZ1ijdk6wc0snzJc69k Donc ce modèle permet aux “non-matheux” d’aborder cette compréhension… 2 jeux “Épidémie Covid19 #1 et #2” , permettant de vivre (en”pour de semblant”) la dynamique d’une épidémie, vont accompagner ces modèles , qui ne sont que le débriefing de ce qui s’est passé dans ces “jeux”. • Websites récents sur "Epidémies & modélisation" : 1.https://www.youtube.com/watch?v=bM7AOBxqjnE, titré "Cette pandémie, vue depuis 2021" du site "Dirty Biology", 2.https://sciencetonnante.wordpress.com/2020/03/12/epidemie-nuage-radioactif-et-distanciation-sociale/ , titré "Épidémie, nuage radioactif et distanciation sociale", 3.https://medium.com/tomas-pueyo/coronavirus-le-marteau-et-la-danse-bce68d354c0c, titré "Coronavirus, le marteau et la danse". -------------------------------------------------------------------------------------------------------------------- • 2. English: Models for a better understanding of the dynamics of an epidemic and how protective measures make it possible to mitigate the effects "- Interdisciplinary project Hervé Gigaroff, High-school Emile Combes de Pons 17 (France) • Here is Basic model “1.B” to begin to better understand the dynamics of an epidemic, type CoVid 19, in asimplified but completely realistic way… … Before seeing, with the further models, how measures taken can mitigate the effects For the "math minded students”, fans of differential equations, this model is nothing else than the shaping, according to the laws of the "DYNAMIC SYSTEM" of what is represented, in differential equations in this excellent video : https://www.youtube.com/watch?v=-2tI3MQFqkI&fbclid=IwAR3QdfrTCQPKNUogozNchAlpu0SwTlvQx_fPNaTDjZ1ijdk6wc0snzJc69k So this model allows the "non-math minded students" to approach this understanding ... 2 games “Covid19 epidemic # 1 and # 2”, allowing to live (“for pretense”) the dynamics of an epidemic, will accompany these models, which are only the debriefing of what happened in these “games”. • Websites récents sur "Epidémies & modélisation" : 1.https://www.youtube.com/watch?v=bM7AOBxqjnE, titled "This pandemia, seen from 2021" from website "Dirty Biology", 2.https://sciencetonnante.wordpress.com/2020/03/12/epidemie-nuage-radioactif-et-distanciation-sociale/ , titled "Epidemic, nuage radioactive cloud and social distanciation", 3.https://medium.com/@tomaspueyo/coronavirus-the-hammer-and-the-dance-be9337092b56 , titled "Coronavirus, the hammer and the dance".
model1,007 downloads
Download Model
Environment Biology Science Ecology Education
4410.716
#36

Exponential Growth

sim16,602 runs
Biology Ecology
4241.42
#37

COVID-19: Role of hospitals, soc. dist., and vaccines

sim3,877 runs
Environment Biology Business Technology Science
2508.72
#38

Preventing CVD deaths in Australia

This simulation has been produced by the Sax Institute and funded by Amgen Australia in 2019. It for ... Read more
This simulation has been produced by the Sax Institute and funded by Amgen Australia in 2019. It forecasts and compares different strategies to prevent health and economic burden from cardiovascular disease. 
sim2,326 runs
Biology Science Economics Education Health
2291.0413
#39

Differential Reproduction, Natural Selection Model

This is the fourth model in a sequence of models to show the logic of natural selection, formalized ... Read more
This is the fourth model in a sequence of models to show the logic of natural selection, formalized by Earnst Mayr. Mayr E. The growth of biological thought. Cambridge: Harvard University Press; 1982.
model1,301 downloads
Download Model
Biology Science Education natural selection evolution
2193.713
#40

Epinephrine Signal Transduction

model4,547 downloads
Download Model
Biology Science Education
2101.62
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Uploading a Bundle from Zip

Instead of creating bundles, categories, and assemblies one by one, you can upload a single zip file that contains all of your bundle's content. To create your zipped bundle, make a folder with your bundle's name and add subfolders with your categories' names. The folder tree should have the same structure that you want the categories to have in your bundle. Place your assembly .stmx files in the appropriate category folders, then zip your bundle folder and upload it using the Upload Bundle from Zip link above.

Assemblies, Bundles, and Categories

Assemblies are self contained models that demonstrate common ways to connect together building blocks and that can be used as parts of other models. This is analogous to using prefabricated wall and roof pieces to construct a house.

Bundles are groups of assemblies with a common use or theme. For example, a Health Care bundle might contain a variety of assemblies that aid in creating health care models. When you download assemblies from the isee Exchange™, you download an entire bundle, rather than individual assemblies.

Categories are subgroups of assemblies within a bundle. For example, a Health Care bundle might contain a Funding category for assemblies related to the management of hospital funds. All assemblies must be assigned to a category—they cannot be assigned to the root of a bundle.

Assemblies, bundles, and categories can be created and uploaded to the isee Exchange™ via the options on the Manage My Assemblies page. To learn more, visit our help pages, or take our assemblies tutorial.

Sim App (Sim)

An interface that allows users to interact with a model.

Image of a sim

Sim apps allow users to interact with a model using buttons, sliders, knobs, tables, graphs, and storytelling. These interactions help users understand how parts of a system interact.

Interfaces are created by model authors in the Stella desktop software and can be uploaded to the isee Exchange™.

Model

A diagram that represents how elements in a system influence one another.

Image of a model

Models are mathematical representations of how elements in a system are connected and interact (e.g., ecosystems, organizations, supply chains). When running models on the isee Exchange™, results can be viewed in output devices like graphs and tables.

Models appear in the isee Exchange™ directory when authors upload them from the Stella® desktop software or create them with Stella Online™.

Causal Loop Diagram (CLD)

A map that represents the feedback structure of a system.

Image of a CLD

CLDs are high-level maps that represents the feedback structure of a system and easily communicate the essence of a model. They appear in the isee Exchange™ when authors upload them from the Stella desktop software or create them with Stella Online™.