In a strategy game, players engineer and evolve an imaginary pathogen with the ultimate goal of infecting and overpowering a simulated world. As the disease begins to spread, global organizations respond with defense strategies and medical interventions. Players can enhance or modify the pathogen’s abilities, including how it transmits, what effects it causes, and how well it survives in different environments. This fictional game uses a simulated global network with factors like population clusters, travel connections, and mobility patterns to portray the rapid and adaptive spread of the disease.

In the game, a player chooses to begin their disease in a densely populated country that also contains a major international airport. Surprisingly, even without evolving any new transmission traits, the disease rapidly appears on multiple continents soon after the first few infections. Which option best explains this rapid early-game global expansion?

             

A) The rapid spread occurs because global populations behave according to a perfect homogeneous mixing model, allowing infected individuals to interact uniformly with anyone in the world.

B) The disease spreads quickly because international air travel forms a high-mobility global transportation network.

C) The spread happens because the initial infected individuals automatically behave as biological superspreaders, independently of human mobility or transportation patterns.

D) Geographic spread is slow at first because limited human mobility keeps early infections confined to the region where the disease originated.

E) None of the above

Original idea by Carolina Albuquerque

You are the team leader in your firm’s Cybersecurity Department, responsible for maintaining four critical corporate networks: AegisNet, MercuryGrid, HeliosCloud and VanguardLink 

Early one morning, you notice that several nodes across all four networks have been unexpectedly shut down. A quick inspection of the system logs reveals the exact sequence in which each node went offline. Your mission is to determine whether this incident represents a coordinated cyberattack targeting multiple systems simultaneously, or if it is merely the result of random hardware failures in aging equipment.

Time 0 : 

Time 1:  

Time 2: 

A) Was a attach in all networks

B) Was a attack only in VanguardLink

C) Was a attach only in AegisNet and VanguardLink

D) Was a attack only in AegisNet, MercuryGrid and VanguardLink

E) None of the above.

Original idea by: Carolina Albuquerque

You decided to do something different for Halloween this year and designed a cornfield maze using your knowledge of network science. Each section of the maze is a node, and the paths between them are edges. You get to decide how to connect them.

To make your maze truly spooky, you aim to create an uneven structure, the kind that confuses and scatters explorers through narrow paths and unexpected turns, rather than keeping them clustered together. Every path should remain connected to the network, ensuring no one gets completely lost… just delightfully disoriented.

A. Assortative design - hubs show a tendency to link to each other.

B. Disassortative design - Hubs tend to avoid linking to each other.

C. Neutral design - Nodes connect to each other with the expected random probabilities.

D. Perfectly assortative design - Every hub only connect to another hub.

E. None of the above

Considering the Barabási–Albert model, mark the correct alternative regarding growth and preferential attachment. The probability values are rounded to two decimal places.

A) Node M is the node with the highest probability of receiving a link from a new node, of 0.13.

B) Node D is the node with the second highest probability of receiving a link from a new node, of 0.10.

C) Nodes A, C, L, P, and I have the same probability of receiving a new link, of 0.02.

D) Nodes N and E have the same probability of receiving a new link, of 0.08.

E) Nodes H and D have different probabilities of receiving a new link, of 0.08 and 0.09 respectively.

A) F F T T F

B) T F T T F

C) T T F F T

D) T F T F T

E) None of the above

Original idea by: Carolina Albuquerque

Consider a real scale-free network of cellular signaling where the nodes are proteins and the links are interactions between them. Mark the INCORRECT alternative about this network.

a) This network is finite.

b) This network has a degree distribution with a power-law tail.

c) This network will likely exhibit scale-free behaviour, meaning there is no characteristic scale for fluctuations.

d) In this network, most proteins will show high connectivity and can be considered hubs.

e) None of the above.

Based on what has been presented about random graphs in class, correctly identify whether each statement is True (T) or False (F).

1. There is no network in nature that we know of that would be described by the random network model.

2. Edges are independent and have the same probability p. 

3. The clustering coefficient of random graphs is small.

4. The study of random graphs is NOT useful to understand real systems. 

5. Random graphs can develop a giant connected component once the edge probability passes a critical threshold.

a) F  V  V  F  V 

b) V  V  V  F  F

c) V  V  V  F  V

d) V  F  F  V  F

e) None of the above

The Health Department of the imaginary region Scarlet is preparing contingency plans for a potential pandemic. To ensure efficient allocation of resources, they want to determine:

1. Which city would serve as the most effective distribution center for medication, guaranteeing accessibility to the largest number of other cities in the shortest time.

2. Which city would serve as the most strategic location for establishing a blockade, in order to minimize the potential spread of infection to other cities within the network?

Considering the graph below, where each node represents a city and the only means of connection between them is via roads represented by the edges, which cities represent the best candidates for these roles?

A) City 5 as the distribution center and City 4 as the blockade

B) City 3 as the distribution center and City 3 as the blockade

C) City 5 as the distribution center and City 3 as the blockade

D) City 3 as the distribution center and City 4 as the blockade

E) None of the above 

Original idea by: Carolina Albuquerque