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Improving the Odds of Completing High School on Time

SED-based Center for Promise studies what it will take to help more students

America’s on-time graduation rate is at an all-time high, with more than 80 percent of students walking across that coveted stage. But not everyone gets an equal share in the joy: African American, Hispanic, and low-income students graduate at rates significantly below the national average. For one group in particular, the chances of collecting a diploma are miserable. In five states, fewer than 50 percent of English-language learners (ELLs) graduate in four years; in two-thirds of states, the number is below 70 percent.

At the School of Education–based Center for Promise, researchers are studying what it would take to get more students graduating on time; the goal is to get the national rate above 90 percent by 2020. One way to help many states, including Massachusetts, step over that threshold is to increase the number of ELLs earning the right to wear a cap and gown. The Bay State graduated 87.3 percent of its class of 2015; the rate for ELL youth, who make up roughly a tenth of students, was 64 percent.

“When we look at the data around ELL students in this country, the graduation rates are some of the worst among any subgroup; it’s not that they can’t succeed, but clearly something’s not going right,” says Jonathan F. Zaff, founder and executive director of the Center for Promise. The center studies the academic and social factors that help young Americans succeed—or not. “All young people have potential, and what we as a society need to do is align the strengths and resources of our community with what the young person needs.”

In 2017, the Center for Promise partnered with the Massachusetts Department of Elementary and Secondary Education (DESE) on a study to “really get into the lives of youth whose first language is not English,” says Zaff, and to understand what it will take to improve their chances of prospering.

The researchers, funded by Pearson Education, a company that provides education publishing and assessment services, conducted a statistical analysis of statewide data, such as free lunch eligibility and grades, on more than 13,000 students whose first language is not English (FLNE)—a group that includes English language learners, plus those who’d previously mastered English, but at some point did not speak it. They also interviewed 24 Latinx (the center uses this gender-inclusive alternative to Latina or Latino) youth from across the state.

“When we look at the data around ELL students in this country, the graduation rates are some of the worst among any subgroup; it’s not that they can’t succeed, but clearly something’s not going right.”
—Jonathan F. Zaff

After compiling results, the team found many FLNE students were performing well—sometimes better than their native peers—and that the language spoken at home didn’t always dictate outcomes. For instance, among low-income Spanish-speaking students, those who were longtime residents of the United States had strong graduation rates; their peers who’d been in the country for fewer than two years struggled. Researchers found that one year might make all the difference for those stragglers—their graduation rates jumped significantly when five-year, rather than four-year, graduation figures were considered.

In their report, the researchers conclude that regardless of whether schools are constrained by laws or resources, educational programs don’t tend to reflect the diversity of FLNE students’ needs. Zaff, also an SED research associate professor in applied human development, says tailoring interventions for specific groups—internships and flexible schedules for older youth who may already be part of the workforce, language-learning programs for students’ parents—could “provide the support and opportunities that FLNE youth need to succeed academically.” He adds that the DESE is now working with a coalition of school districts to implement strategies designed to keep FLNE youth in school.

It’s typical that the center, which is the research arm of America’s Promise Alliance—a coalition of more than 400 corporations, nonprofits, and professional associations—produced recommendations not solely focused on the classroom. Its research projects frequently cover health, well-being, and other factors impacting a young person’s chances of success.

Zaff gives the example of “Don’t Call Them Dropouts,” the center’s nationwide study of 18-to-25-year-olds that was supported by Target and published in 2014. Researchers found most dropouts didn’t deserve that label, concluding that toxic circumstances—violence at home, serious health issues, homelessness—“made schooling less salient to their lives, preventing them from finishing school,” he says. Many students found help hard to come by. When one of them, Antonio, tried to tell adults at school about his difficulties at home—including absent parents and an experience with homelessness—“they didn’t care,” he said in the report. “You know from the way that they come at me on a regular basis…they don’t try to talk to me.”

The center recommended starting community navigator programs—adults mentoring youth through traumatic life events—and school-based early-warning systems to flag students facing issues that could push them out of education. In a national follow-up study, Zaff says, the center concluded “it’s a ‘web of supports’ that youth need in order to stay on track in school or to reengage if they have disengaged.”

Zaff hopes that a greater appreciation for the adversities bombarding youth, especially those who might seem hard to reach or appear threatening to some adults, encourages more people—from teachers to school janitors—to make a connection with them. It can often be enough, he says, just to recognize the issues facing a young person and point them in the right direction for help.

“If we can start to change people’s understanding about who these young people are and about what they deal with on a daily basis, then we’ve made progress.”

Andrew Thurston can be reached at thurston@bu.edu.

Follow Your Ears

BU researchers study how people with hearing loss locate sounds

Virginia Best (above) and colleague Gerald Kidd are studying how people with hearing impairments locate sounds, a skill called spatial hearing. Photo by Jackie Ricciardi.

The next time you’re at a loud party, close your eyes and listen. At first, the sounds are just a fog of noise. But quickly you begin to pick out individual voices and locate them, even without looking. This ability to locate voices using sound alone is called spatial hearing, and it helps listeners follow conversations in noisy places, like cocktail parties and restaurants. For people with normal hearing, it happens almost effortlessly. But people with hearing loss often have trouble with spatial hearing, even when they have hearing aids on. Why?

“This is a problem that conventional hearing aids don’t solve,” says Gerald Kidd, a Sargent College of Health & Rehabilitation Sciences professor of speech, language, and hearing sciences, who heads BU’s Psychoacoustics Lab. “In a room full of people talking—a party, a social situation—sometimes people with hearing loss are lost and they disengage. It has a real human consequence.”

With the support of a five-year, $1.5 million National Institutes of Health grant, Virginia Best, a Sargent research associate professor of speech, language, and hearing sciences, will be examining how spatial hearing works differently in people with hearing impairments. The new research brings together Kidd and Best, the lead investigator, with experts in audiology, neuroscience, and biomedical engineering: neuroscientist Barbara Shinn-Cunningham, a College of Engineering professor of biomedical engineering, H. Steven Colburn, an ENG professor of biomedical engineering, who develops neural models of spatial hearing, and Jayaganesh Swaminathan, a Sargent research assistant professor and a hearing aid researcher at the Starkey Hearing Research Center in Berkeley, Calif. Their discoveries may one day guide the development of new hearing aids that give hearing-impaired listeners the location information they have been missing, potentially solving the cocktail party problem in a way not currently possible with traditional hearing aids.

Just as having two eyes helps us locate things in three dimensions, our two ears help us pick out the location of sounds. “A sound off to the right gets to your right ear a little bit before it gets to your left ear, and it also tends to be a little louder in the ear that’s closer,” says Best. The differences are so small that we don’t consciously notice them: the time delay is just a matter of microseconds, and the volume difference (that is, the difference in sound pressure on the ear) can be as little as a decibel. Yet the brain uses this tiny ear-to-ear discrepancy to draw up a remarkably precise mental sound map, accurate to about one degree, that it uses to locate and focus attention on a single voice.

For people with hearing loss, though, this process breaks down, and Best wants to find out why. One hypothesis is that people with hearing loss are not getting the full timing and volume information they need to locate sounds accurately. Another possibility is that they are getting all the right information, but the brain cannot decipher it properly, so the resulting mental sound map comes out fuzzy.

Before they can begin to test these ideas, Best and her colleagues must first figure out how to untangle spatial hearing from other functions that are undermined by impairments. This is tricky, because although we often think that people with hearing loss experience the world with the volume knob turned down, the reality is more complicated. For some listeners, low-pitched sounds are clear while high-pitched sounds are muffled, for others, it’s the other way around, while still others experience distortion all across the sound spectrum. “We want to estimate how much of the real-world difficulty experienced by a person with hearing loss can be attributed to the audibility of sounds, and how much can be attributed to spatial factors,” says Best. “These results could also help guide our colleagues in audiology and in the hearing-aid industry to focus their efforts in the appropriate places.”

Next, Best and her colleagues will bring volunteers into the lab to test their spatial hearing. Using headphones and arrays of loudspeakers, they will find out how well people with hearing impairments can locate the sources of computer-generated sounds. Similar experiments have been done before, but unlike those earlier studies, the new experiments will use speech-like sounds instead of electronic beeps. “Our sounds will still be computer-generated, but they will be more natural in their acoustical structure and their content,” says Best. By using realistic sounds, she hopes to more closely mimic the challenges hearing-impaired listeners face in the real world.

While the researchers will compare hearing-impaired volunteers with volunteers who hear normally, they will also be looking for differences within the hearing-impaired group. The goal is to see if some subgroups—for instance, elderly people—have bigger spatial hearing losses than others. In the past, it has been difficult for them to isolate pure hearing loss from normal aging, because they so often go hand in hand. But Boston, with its large population of students and other young people, is an ideal place to study hearing loss clear of age-related confounds.

Best and her colleagues will also be taking a closer look at how listeners tune in to specific speakers in noisy environments. This process of zeroing in happens quickly and automatically for people with normal hearing, usually within just a few words or sentences. Best wants to find out whether listeners with hearing loss experience something similar and to discover more about how it happens.

Ultimately, the researchers hope that they can use what they learn to help build better hearing aids. Some new noise-reducing hearing aids send exactly the same sounds to both ears, blotting out potentially helpful spatial cues. But, says Best, “there are ways of maintaining some of that spatial information, and it might be that different listeners need that to different extents, depending on how sensitive they are to that spatial information.” Best and Kidd have already tried this on a version of their visually guided hearing aid, an experimental device that uses eye tracking to guide a beam of amplification toward sounds coming from a particular direction. Early results are promising, but, says Kidd, it will take more basic research to invent a hearing aid that can untangle the cocktail party problem. “The real essence of the problem, the ability to hear one talker in uncertain and difficult situations,” he says, “is something that hasn’t been solved yet.”

Author, Kate Becker can be reached at kate@spacecrafty.com.

Hearts, Minds, and Microbubbles

Sargent, ENG profs collaborate to prevent strokes that cause dementia

BU faculty Tyrone Porter and Kathleen Morgan are using a $2.5 million grant from the National Institute on Aging to develop a drug, and a delivery system, that may help prevent blood vessels from bursting and causing early-stage dementia. Photo by Jackie Ricciardi.

• Stiffened arteries can cause microbleeds in the brain, possibly leading to dementia
• A prototype drug might control artery stiffness
• Microscopic bubbles and ultrasound beams could deliver the drug straight into artery walls

Memory loss in old age starts small, with misplaced keys or wallets. In some people, it can be the sign of a far more serious disorder. Dementia can eventually set in, robbing people of the memories of faces, names, and important events. It’s devastating for both patients and family members—and it’s distressingly common. According to the World Health Organization, more than 47 million people currently suffer from dementia worldwide.

While Alzheimer’s disease is probably the most well-known form, dementia also comes in other, lesser-known varieties, like vascular dementia—caused when tiny blood vessels burst in the brain, leading to microstrokes and minute bleeds. The resulting condition is closely linked with other age-related memory disorders.

“I suspect that vascular dementia and Alzheimer’s are really just two different angles on the same disease,” says Kathleen Morgan, a Sargent College of Health & Rehabilitation Sciences professor of health sciences. “There are plaques in the brain tissue of Alzheimer’s patients that are visible at autopsy, but we know that if you have them, you’ll probably see evidence of microbleeds as well.”

And if burst blood vessels are implicated in early-stage dementia, Morgan says, it may be possible to stop that damage before it starts. With a $2.5 million grant from the National Institute on Aging (NIA), she is examining a synthetic prototype drug that could prevent microbleeds in mouse brains. She’s joining forces with Tyrone Porter, a College of Engineering associate professor of mechanical engineering, working across disciplines to develop a new delivery system for the drug. Their solution uses a novel system of microbubbles—tiny bubbles of inert gas smaller than capillaries—along with a focused ultrasound beam to help push the drug into a very specific part of the body: the large blood vessels next to the heart.

Most brain bleeds, Morgan says, actually start in the aorta, the body’s largest artery, which connects directly to the heart. With each beat, the heart exerts enormous amounts of pressure straight onto that conduit, which is made of smooth muscle cells that expand and contract like a rubber hose as blood flows past them. “Those smooth muscle cells are very important for controlling the pressure of your vascular system on a beat-to-beat basis,” she says.

In younger bodies—both mouse and human—smooth muscle in the aorta expands with each beat, acting as a sort of shock absorber for the pressure coming out of the heart. In older bodies, though, it becomes gradually less elastic, meaning that the energy of each pulse travels farther through the vascular system. If the aorta becomes stiff enough, blood can surge at high pressure straight into tiny, sensitive blood vessels in the brain, which may burst under the strain.

Morgan is developing new ways to reverse the stiffening of arteries. If she can restore some of the aorta’s elasticity, she reasons, it may be possible to prevent new microbleeds. To test this idea, she’s concocted a new peptide—a small chain of amino acids—that can control smooth muscle stiffness.

Morgan and Porter’s drug delivery system. The scientists attach the drug to microbubbles smaller than capillaries and use a focused ultrasound beam to guide the bubbles and then burst them, delivering the drug directly into smooth muscle cells. Eventually, they hope their system may be used to deliver drugs to the large blood vessels next to the heart. Illustration by Tyrone Porter.

In smooth muscle tissue, she says, elasticity is determined in part by two types of long, stringy molecules called actin and myosin, which form a web inside each cell. As the two strands latch onto each other, they restrict the cell’s movement, stiffening its structure. “It’s a bit like a Chinese finger trap,” says Morgan. “The harder you tug on actin, the harder it clamps down.” The peptide her team has created, however, can effectively stop this process in its tracks by binding to the molecules, preventing them from grabbing onto their counterparts in the first place. As a result, the cell remains relaxed and supple. Morgan can control how stiff or loose the tissue gets by controlling the amount of peptide she administers.

The challenge is delivering those molecules directly to the smooth muscle inside a living aorta. Unlike other drugs, releasing this one system-wide—or even artery-wide—could be disastrous. “Smooth muscle tissue isn’t just in the aorta. It’s in your vascular system, urinary tract, uterus, lung tissue, and digestive system,” she notes. “If the peptides got into those tissues, it could cause incontinence, premature labor, all sorts of awful things.”

To get the drug exactly where it’s needed, however, you first have to dig into the artery itself.

“The cells we need to target don’t come in contact with flowing blood. They’re behind a layer or two of other cells and connective tissue in the blood vessel walls,” says Porter. To break through those layers and deliver the drug directly to smooth muscle cells, he’s attaching Morgan’s peptides directly to the outside of each microbubble. Focused ultrasound can be used to push the microbubbles toward the aortic wall and pop them to release the peptide. The popping process also subtly and reversibly disrupts the lining of the aorta, making the blood vessel wall temporarily permeable. “Once that happens, the peptide can flow directly into the spaces that open up in the vessel wall and go straight into the smooth muscle tissue,” he says.

These microbubbles themselves are simple to make, Porter adds, and the FDA has already approved them for use. “Microbubbles have been used for years as contrast agents for ultrasound. They scatter sound much better than tissue, so they’re used to distinguish blood from the chambers in heart and surrounding muscle,” he says. They’re also tiny enough to fit through the smallest blood vessels in the body and eventually disappear as the gas, which is harmless, escapes into the blood and is expelled out of the body through the lungs.

In addition to being relatively safe, the clinical advantage of this approach is that it can be done with a standard ultrasound probe commonly used in a cardiac echo test. Using a low-powered ultrasound beam, a technician can track where the bubbles are going, then pop them at a specific location by simply turning up the strength of the beam. Existing ultrasound tools “can focus the beam down to the millimeter, so it’s extremely accurate,” Porter says.

Until now, Morgan has been able to test her peptide and its new delivery system only on smooth muscle cells in a petri dish. With the new NIA grant, however, she and her collaborators are looking to scale up their research, and they will use their approach for the first time on a living animal.

“My earlier work was just on the fundamental mechanics of these peptides. Moving into a whole mouse is a big leap for someone used to sitting at a bench dealing with cells,” she says with a laugh. “The people I’ve connected with here at BU make it feasible, though. That’s how you get basic discoveries translated into practical ones—you have lots of scientists working in parallel. You need teams instead of a single investigator.

Author, David Levin can be reached at delevin@bu.edu.