Note: This story is part of an ongoing series profiling graduate students in the School of Life Sciences. See March’s featured students here.  

The research that goes on in the School of Life Sciences spans a huge and fascinating variety of subjects. The graduate students who make up SOLS are no less diverse or interesting, arriving at their respective research from different places and with different passions. Here, we recognize a handful of these graduate students, their work and what motivates them to pursue it. 

Allison Hays – Neuroscience 

Our childhood experiences have a huge impact on the rest of our lives; they shape our beliefs about the world, the relationships we form, and our physical and mental health well into adulthood. Allison Hays, a second-year neuroscience PhD student in the BEAR Lab, is diving deeper into understanding how our experiences are so impactful by exploring their interaction with genetics. 

Hays specifically thinks about how childhood experiences affect certain cognitive functions, like the ability to remember things, pay attention, and switch easily from one task to another. But rather than looking at the brain to figure this out, she looks at our spit––the easiest way for her to get samples of DNA. When she looks at spit samples, she doesn’t just try to read the DNA they contain; she’s more interested in seeing how the DNA within them is being regulated. Specifically, she looks for occurrences of DNA methylation, which is a modification that prevents gene expression.  

“We don't have all of our DNA being expressed at one time. There are things that turn gene expression on and off, or up and down.. So, what we look at is not necessarily what genes you are given, but what genes are on, off, up, down, etcetera. So that's then going to affect... your biology, your health, and cognition. I specifically think about how stressful experiences can be associated with poorer health and different rates of development and aging- which may ultimately go on to impact a variety of things.” 

So, Hays measures the cognitive performance of her research subjects, assesses how stressful their early childhood experiences were and looks at what genes are turned on or off in the DNA in their spit samples. With all that information together, Hays can start to understand how early childhood stress can change gene expression and affect cognitive performance. 

This holistic look at stress, genetics and brain function altogether excited Hays, who conducted related research with the Arizona Twin Project and the Memory Attention Control lab at ASU as an undergraduate. Now, she’s conducting novel work that she hopes will one day improve how scientists assess and improve humans’ health and wellbeing.  

“I think it will be extremely important for assessing people's level of health risks depending on their childhood stress levels, and monitoring whether any types of treatments or interventions are working... By looking at the gene expression, we’ll finally be able to see on a genetic level which treatments are working and which are not.” 

Isabel Torres – Environmental Life Sciences 

Arizonans might think they’re well-acquainted with the desert, having lived among its summer monsoons, soaring temperatures, and temperamental dust storms. But most Arizonans have no idea why the desert is important. 

Not Isabel Torres. The second year PhD student in the Throop lab is dedicating her research to better understanding deserts and other dryland ecosystems, which most people have overlooked.  

“Deserts are amazing. People think that there's nothing living or going on there. But there's so much activity.” 

A third of the world’s human population already lives on drylands, or ecosystems like deserts defined by water scarcity, and that number will only increase: by the end of the century, drylands will likely make up 56% of Earth’s land cover, Torres explains. To protect the people who depend on drylands, scientists must understand how to best manage and care for that land. But that’s not something they currently understand. 

Torres plans to help correct that. She’s spending her PhD doing field work to study how carbon cycles through dryland ecosystems, which is important for scientists who make models that predict what the climate will look like in the future. Current climate models for dryland ecosystems rely on data collected from other ecosystem types, which is troubling –– it means that those models are inaccurate. Torres aims to generate data that can be used to make accurate climate models, which will help land managers take care of the land. 

That goal, Torres shares, is inspired by her hometown: “I grew up in El Paso, Texas. It’s a desert. But it wasn’t always a desert. Back in the 1800s, it was a grassland. It was pretty and beautiful. But then they overgrazed the landscape, leading to desertification... So, I’m really interested in land management practices and how we can take care of the land.” 

Torres recognizes that living on drylands is tough: water and other resources are scarce, so people must work to prevent desertification where they can. At the same time, she loves the desert, and though she knows life there is tough, she doesn’t want that to stop people from seeing how much the land still gives us. She hopes her work can help people protect the land in return. 

Note: This story is part of an ongoing series profiling graduate students in the School of Life Sciences. See February’s featured students here.  

The research that goes on in the School of Life Sciences spans a huge and fascinating variety of subjects. The graduate students who make up SOLS are no less diverse or interesting, arriving at their respective research from different places and with different passions. Here, we recognize a handful of these graduate students, their work, and what motivates them to pursue it. 

Jules Petty – Environmental Life Sciences Program 

You might think that climate scientists mostly think about what’s around and above us, in our atmosphere. But Jules Petty, a second year PhD student, studies climate by going underground and looking at our soil. 

“I choose to study soil because I think it’s a pretty strong way of interpreting how an ecosystem is functioning... Being able to identify the processes [occurring in the soil] and understand them... can give us a picture of what is happening more broadly.”  

Petty will be collaborating with Yiqi Luo’s Eco Lab at Cornell University in Ithaca, New York, to help create accurate computer-generated models of how carbon cycles through an ecosystem.  

“Modeling is just how to simplify the snapshots of data that we get into one cohesive story. We can look at the old theories of what people thought [about] how carbon cycled in the past and improve upon those stories with new data.” 

Petty specifically looks at ways to model how carbon cycles through the soil in dryland ecosystems, or ecosystems characterized by a lack of water, like much of Arizona. Drylands make up a huge portion of the Earth’s surface –– about 40 percent –– but are very understudied as far as how carbon cycles through the ecosystem, according to Petty.  

As the species living in dryland ecosystems shift along with climate change, it’s important for scientists to understand how those changes will affect the way carbon cycles in drylands, Petty says: “We know humans can’t exist without the natural resources our world’s ecosystems provide. Now that we are seeing important ecosystems changing, it’s critical to understand where they are going and how they can still support our communities sustainably.” 

Petty hopes that their research will help land-use managers in drylands make decisions about how to protect their land in the future. 

Jarrett Joubert – Biology and Society Program, History and Philosophy of Science track 

The HIV/AIDS epidemic in the 1980s changed the medical field and the social status of queer people forever. Jarrett Joubert, a third year PhD student, hopes to learn more about the decisions that scientists had to make when trying to treat the deadly epidemic –– decisions that have affected the lives of tens of thousands of people. 

“My research will be telling the story of how [HIV] drugs were developed, specifically why scientists chose to pursue one class of drugs over another.” 

Joubert has a personal stake in this subject: “I’m a queer Black man... [belonging to] a group that has some of the highest risk factors for HIV. I always think about HIV –– even if I don’t want to –– because it's a script that’s been put on my body. That’s why I’m so interested in researching this.” 

Joubert was recently accepted into Knowledge of AIDS, an NSF-funded research community development project creating a network amongst scholars who study HIV/AIDS. As part of the network, Joubert will have the chance to attend yearly workshops around the US with interdisciplinary HIV/AIDS researchers.  

“I’m excited because as a graduate student... you’re [working] by yourself so much. This [opportunity] will enable me to talk to a lot of other people who care about the same stuff, but study it in a different way.” 

As Joubert learns more about how scientists made decisions when developing HIV treatments, being part of the network will help him connect that history to its broader social impacts, which still affect people like him today.