RIP Abdul-Aziz Yakubu (1958–2022)

A couple of weeks ago, I heard the very sad and unexpected news that Abdul-Aziz Yakubu had died. Aziz was great.

Like others, I also have some Aziz stories (but the one that I wanted to tell seemed a bit too light-hearted to tell immediately on social media): I know Aziz from my days helping out with MTBI as a PhD student. On one occasion, when somebody — one of the students? — was being a bit formal with my name as I entered a room and was also using my last name or something, I made the mistake of loudly proclaiming "I'm like Madonna. I only need one name." With a quietly wicked sense of humor (and with the knowledge that we'd all be amused by this, including me), Aziz proceeded to jokingly call me "Mason Madonna" for the next several years.

You can read more about Aziz in his 2020 Mathematically Gifted & Black profile.

RIP Vin Scully (1927–2022)

I'm watching the game, and the Dodger broadcasters announced about 20 or so minutes ago that broadcasting legend Vin Scully died today. (Scully's death was announced by the Dodgers in the tweet to which I just linked, along with other simultaneous social-media posts.) Vin was the greatest broadcaster who ever lived. I listened to Vin broadcast literally thousands of games across four decades. Vin was one of the key voices of my childhood (and much of my adulthood). For so long, Vin was not only the voice of the Dodgers, but was also (along with Tommy Lasorda) the pulse of the Dodgers.

Here is Vin's Wikipedia page.

Update: ESPN has now posted an article about Vin Scully's death.

RIP James Lovelock (1919–2022)

James Lovelock, who proposed the Gaia hypothesis (which postulates that the Earth functions as a self-regulating system) died today. You can read more about him on his Wikipedia page.

When I was in high school, I did a report on the Gaia hypothesis. I suppose that that was my start in complex systems?

(Tip of the cap to Alun Lloyd.)

What Happens at Santa Fe Institute Stays at Santa Fe Institute

I am heading off to Santa Fe Institute (SFI) for a bit.

RIP Pogo (1998–2022)

Pogo, the infamous cat of Somerville College, died on 26 June at the wizened age of 23 years and 10 months. Pogo's ashes will be scattered in his favorite spot in College just after the memorial for Dame Fiona Caldicott (who, of course, was Pogo's alter ego). That is immensely fitting.

RIP Mike Brito (1934–2022)

Longtime Dodger scout Mike Brito died today. For many years, Brito was a familiar sight behind the dugout with his cigar.

Retirement Conference for Colin Please

Unfortunately, I just checked and I am still COVID positive, so regrettably I will be missing the retirement conference and party for my Oxford colleague Colin Please. (Alhough I am far from perfect, I feel well enough to have attended if I weren't still testing positive. I may chat with some people during a break outside and from a safe distance.)

A more general thing to point out, and it relates to the fact that I already interacted with Colin several years before he joined the Oxford faculty — I wonder if he remembers my antics during the 'mock tutorial' part of his Oxford interview? — is that I have always admired and enjoyed just how tightly know the British applied-mathematics community is. People across some many of the institutions know each other really well and often "randomly" show up at events in nearby cities even when their affiliations are different. I miss that.

Congratulations to Colin on his retirement!

"Networks of Necessity: Simulating COVID-19 Mitigation Strategies for Disabled People and Their Caregivers"

One of my papers just came out in final form. Here are some details.

Title: Networks of Necessity: Simulating COVID-19 Mitigation Strategies for Disabled People and Their Caregivers

Authors: Thomas E. Valles, Hannah Shoenhard, Joseph Zinski, Sarah Trick, Mason A. Porter, and Michael R. Lindstrom

Abstract: A major strategy to prevent the spread of COVID-19 is the limiting of in-person contacts. However, limiting contacts is impractical or impossible for the many disabled people who do not live in care facilities but still require caregivers to assist them with activities of daily living. We seek to determine which interventions can best prevent infections of disabled people and their caregivers. To accomplish this, we simulate COVID-19 transmission with a compartmental model that includes susceptible, exposed, asymptomatic, symptomatically ill, hospitalized, and removed/recovered individuals. The networks on which we simulate disease spread incorporate heterogeneity in the risk levels of different types of interactions, time-dependent lockdown and reopening measures, and interaction distributions for four different groups (caregivers, disabled people, essential workers, and the general population). Of these groups, we find that the probability of becoming infected is largest for caregivers and second largest for disabled people. Consistent with this finding, our analysis of network structure illustrates that caregivers have the largest modal eigenvector centrality of the four groups. We find that two interventions—contact-limiting by all groups and mask-wearing by disabled people and caregivers—most reduce the number of infections in disabled and caregiver populations. We also test which group of people spreads COVID-19 most readily by seeding infections in a subset of each group and comparing the total number of infections as the disease spreads. We find that caregivers are the most potent spreaders of COVID-19, particularly to other caregivers and to disabled people. We test where to use limited infection-blocking vaccine doses most effectively and find that (1) vaccinating caregivers better protects disabled people from infection than vaccinating the general population or essential workers and that (2) vaccinating caregivers protects disabled people from infection about as effectively as vaccinating disabled people themselves. Our results highlight the potential effectiveness of mask-wearing, contact-limiting throughout society, and strategic vaccination for limiting the exposure of disabled people and their caregivers to COVID-19.

What Happens in the United Kingdom Stays in the United Kingdom

I arrived in Oxford a bit over a week ago, but I forgot to blog about it. I then visited friends in Newcastle during the weekend and returned to Oxford on Monday. Unfortunately, I caught COVID and have thus delayed my return flight to the US. I am currently in a room in Somerville College (in Oxford) struggling through COVID and gradually (but bumpily) improving.

What Happens in Stockholm Stays in Stockholm

I am about to head to Stockholm for a networks conference that we were supposed to have in 2020. Only a bit late!

This is my first international flight during the COVID era. Meanwhile, I'll also be desperately trying to grade my final projects and finally finish the academic year.

RIP Roger Angell (1920–2022)

Famed writer and editor Roger Angell has died at age 101. Take a look at this article. I hadn't realized it before reading this article, but Angell is from quite a famous family.

Here is Angell's Wikipedia entry.

"How Do Our Brains Support Our Friendships?"

One of my articles just came out in final published form. Here are some details.

Title: How Do Our Brains Support Our Friendships?

Authors: Elisa C. Baek, Ryan Hyon, Mason A. Porter, and Carolyn Parkinson

Abstract: Have you ever wondered how your friends impact how you see the world? Or how you are able to keep track of the many different people in your life? To study these questions, scientists have begun to look at people’s social networks and their brains at the same time. In this article, we introduce this area of study and discuss how scientists use ideas from both neuroscience and mathematics to examine these questions. We also highlight some recent discoveries that reveal both how our brains support our ability to socialize with others and how our relationships with other people are related to how we use our brains.

What Happens in Davis Stays in Davis.

I am off to a short workshop at UC Davis.

However, I just almost accidentally boarded a flight to Hawaii.

I am flying to Sacramento for the workshop at UC Davis.

[I also just noticed: One of the PhD students in my class is actually here and probably on the same flight.]

A Great Visual Illusion: Radiating the Same Luminance

This is a great visual illusion.

The top and bottom chess pieces radiate the same luminance. (I did some sampling to check, and it seems to check out.)

(Tip of the cap to Luiz Pessoa.)

2022 Rock & Roll Hall of Fame Inductees

The Rock & Roll Hall of Fame has announced its 2022 inductees! They include Duran Duran, Eurythmics, Pat Benatar, and Harry Belafonte.

"Topological Data Analysis of Spatial Systems"

A book chapter of ours was just published in final form. It is Chapter 16 in this book. Here are some other details about it.

Title: Topological Data Analysis of Spatial Systems

Authors: Michelle Feng, Abigail Hickok, and Mason A. Porter

Abstract: In this chapter, we discuss applications of topological data analysis (TDA) to spatial systems. We briefly review a recently proposed level-set construction of filtered simplicial complexes, and we then examine persistent homology in two cases studies: street networks in Shanghai and anomalies in the spread of COVID-19 infections. We then summarize our results and provide an outlook on TDA in spatial systems.

"Role Detection in Bicycle-Sharing Networks Using Multilayer Stochastic Block Models"

A new paper of mine was published in final form today. The project started in January 2017 as a group project by students in the first course that I ever taught at UCLA. It's taken awhile, but we're finally done!

Title: Role Detection in Bicycle-Sharing Networks Using Multilayer Stochastic Block Models

Authors: Jane Carlen†, Jaume de Dios Pont, CassidyMentus, Shyr-Shea Chang, Stephanie Wang, and Mason A. Porter

Abstract: In urban systems, there is an interdependency between neighborhood roles and transportation patterns between neighborhoods. In this paper, we classify docking stations in bicycle-sharing networks to gain insight into the human mobility patterns of three major cities in the United States. We propose novel time-dependent stochastic block models, with degree-heterogeneous blocks and either mixed or discrete block membership, which classify nodes based on their time-dependent activity patterns. We apply these models to (1) detect the roles of bicycle-sharing stations and (2) describe the traffic within and between blocks of stations over the course of a day. Ourmodels successfully uncover work blocks, home blocks, and other blocks; they also reveal activity patterns that are specific to each city. Our work gives insights for the design and maintenance of bicycle-sharing systems, and it contributes new methodology for community detection in temporal and multilayer networks with heterogeneous degrees.

A Gallery of Ancience d20 Dice

Here is a gallery of ancient d20 dice. I love it! (It includes the one that I discussed in this post. Also see this post and this post. The second of these also showed up in a previous post.

Also, this reminds me: I need more dice.

(Tip of the cap to Chris Klausmeier.)

Hence is the Relief Pitcher

Tink Hence, a relief pitcher, is a prospect in the Cardinal's farm system.

I hope that he makes the Majors, so that we can bring back more of these jokes. My favorite one was when Chin Lung Hu came up with the Dodgers; I always wanted him to reach first base.

And Hence's first name is also great. "Tink Hence" is such a great baseball name. Because.

Dodgers Sign Freddie Freeman!

The Dodgers have reached a deal with free agent Freddie Freeman. As usual with the Dodgers, it'a Moneyball with money.