This story was originally published on May 23, 2016.

UPDATE: Since this story first aired, Yuriana Aguilar is now a postdoc in Chicago, continuing her cardiovascular research. She says she’s currently feeling very insecure about the fate of undocumented students like her once President-elect Trump takes office.

Have you ever seen a beating heart, pulsing on its own for hours, outside of the body? I got to see one last week, after it had been removed from a mouse.

“You can see that it’s still beating,” says 26-year-old Yuriana Aguilar, a newly minted Ph.D. in a white lab coat. “It’s a very impressive organ.”

Aguilar is injecting a special dye into the heart, so she can look at the electrical signaling going on in the membrane of each cell. She's a researcher in a biomedical lab at UC Merced, the University of California’s newest campus. She’s also the first undocumented student to get her doctorate at UC Merced.

Aguilar is looking at mouse hearts to figure out what happens in the human heart just before sudden cardiac death, which kills hundreds of thousands of people each year.

Professor Ariel Escobar, who runs the lab, says Aguilar is the best student he’s ever taught.

"She presented her work at the Biophysical Society meeting. She was the only student in that session. They were all full professors and chairmen of departments, and her!” he exclaims. “She’s superb, superb!"

But Aguilar’s future is uncertain. She came to California from Mexico with her farmworker parents when she was 5. None of them have immigration papers.

"Everybody has the American dream," Aguilar says. “They think, ‘We’re going to strive, we’re going to have our own homes, our own businesses.' My parents have not been better off economically. But they see the American dream fulfilling in me. That keeps me going."

Aguilar has worked her way through school picking watermelons, cleaning hotels and selling produce at flea markets.

"There are fears. I fear that if I’m in the flea market, and they're doing deportations or something, nobody's going to care that I have a title," she says.

As an undergraduate, Aguilar wasn’t eligible for many grants and scholarships. Her parents sold enchiladas and vegetables to help pay her costs. Once she got her bachelor's degree, she was working as an unpaid volunteer in the lab when the Obama administration announced Deferred Action for Childhood Arrivals, or DACA.

"I remember, I was here in the lab when I was watching the news about DACA. I cried," she says. "I was here with the heart, so that was very emotional. To see that I could actually do this, that it would allow me to continue to work here."

DACA allowed Aguilar to get a temporary work permit. She has to renew it every two years, but has no path to permanent legal status. Without that, she can't apply for a lot of government grants and fellowships. She also can't travel to visit the scientists she’s collaborated with in Brazil, Spain and Argentina.

"When you don’t have papers, you are very limited. But science just doesn’t have borders. That's very impressive to me. They don’t exist because that would limit the advancement of technologies and how much progress we’re making in the field," Aguilar says.

An article about her in the local Merced Sun-Star newspaper prompted a number of readers to write in, saying she shouldn't be at the university taking the space of a U.S. citizen, or that she should be deported. I asked her how she felt about that.

"You know, you get discouraged, but I am used to hearing those comments. There are shortages of researchers and physicians. Definitely, if somebody's more qualified, go for it," says Aguilar. "We all compete for the same spots."

"She hasn’t taken anybody’s spot. She earned that," says Alex Delgadillo, who runs a special office at UC Merced  to help undocumented students, and to train faculty and staff about how to assist them.

"Yuriana came here as an undergraduate, distinguished herself at her high school, she continued and excelled, did research here," says Delgadillo. "She was up against competitive candidates, and she distinguished herself in that regard, just like any competitive candidate has to meet the rigorous requirements of a UC."

Serving low-income immigrant students is core to UC Merced’s mission. About two-thirds of its students are the first in their family to go to college, and many are immigrants, like Aguilar. UC President Janet Napolitano recently earmarked $8.4 million to expand support for undocumented students across the UC system.

How Did Two Farmworkers Put Five Kids Through College?

After working at the lab, Aguilar drives with her husband and 1-year-old daughter, Victoria, to visit her parents on their farm in West Fresno. It’s right in the heart of one the most impoverished ZIP codes in the state.

Her parents rent a plot of land to raise goats and grow squash and cucumbers they sell at markets in San Jose.

Yuriana's mother, Ana Torres, is a tough lady. She climbs a tall metal fence and leaps down into the goat pen to help a 3-day-old goat nurse on the mama goat she calls Bambi.

"I have to be tough," she tells me in Spanish. "I raised five kids, and they’re all getting their degrees."

Tending the goats and picking zucchini has destroyed Torres' fancy manicure. She normally doesn't get her nails done, she tells me, but two of her children graduated this week -- Yuriana with her doctorate, and a son as a pilot.

I ask Torres and her husband, Arturo Aguilar, what their secret is. How did two farmworker parents who didn’t finish elementary school put five kids through college?

"We'd talk to them a lot, tell them they're smart," says Arturo. "And we would pay them $20 for every A and B they got. They had to pay us $25 or $30 if they got an F. We had to work harder to earn more money if they got A's, but it was worth it."

And if they didn't do a good job in school, they had to do longer shifts on the farm, picking spiny cactus. Ana and Arturo say they were tough on their kids, but loving, present, involved.

Arturo says a lot of immigrants come from Mexico wanting to buy fancy trucks or cars. "But the best investment you can make is your children’s education," he says. "A car or truck only stays new and shiny for a while. But a child’s education lasts their whole life."

Ana Torres starts to cry as she tells me how proud she is of her daughter getting her Ph.D. She walks over to hug her.

"I am crying, but they're happy tears," says Torres. "Before, I was crying tears of sadness. Especially when Yuriana would call me to tell me that people cared more about her documents than about her intelligence or her perseverance in getting ahead."

"Thank you for believing in me," says Yuriana, "even though there were so many obstacles in our way. I remember you always told me that no one can take away your education. The government may not give you papers, but they can’t take away your learning."

"That's right," says Torres. "I always told you that learning lasts you your whole life. It's the only inheritance you're going to get from us, and as long as we have feet to stand on and hands to work, we’re going to support you."

Yuriana Aguilar says she hopes to open her own medical research lab. She’s got faith that somehow she’ll find a path to citizenship. But even then, she won’t mind working in the fields sometimes -- or even buying a lot of land to farm someday. You have to do every job with dignity, she says, and with your heart.