Every year, U of T faculty members generate hundreds, maybe thousands, of ideas. Sometimes, as with James Till and Ernest McCulloch’s discovery of stem cells in the early 1960s, they change how we think about the world.
The sparks of ingenuity you’ll read about here are new. They could one day affect our health or the environment, or cast new light on concepts such as honesty, justice and privacy. And although it’s still unclear how far they’ll reach, they show that the spirit of inquiry burns brightly at U of T. We hope you enjoy.
Computers that Understand Speech
New software can condense long spoken-word recordings into a few key highlights
Ever since Star Trek first aired, we’ve imagined a world where we could simply talk to our computers and listen to their replies, without the clunky diversion of typing and reading. Suppose, for example, that you missed an important meeting: wouldn’t it be great if a computer could just tell you what the highlights were?
Gerald Penn, a professor of computer science, has been working toward this goal. His specialty is “speech summarization” – not by the traditional method, which would require a human to transcribe every word spoken, but rather an automated process that uses audio recordings of the events themselves, bypassing text altogether.
Penn is developing software that can listen to an audio file (an MP3 of a recorded speech, for example) and keep track of pauses, emphasis and repeated words – what he calls “recurring acoustic patterns.” The software then uses those indicators to condense the audio recording into a new, shorter file that contains the most salient points of the original. And it can do it quickly, too, processing a one-hour recording in just a few minutes.
Until now, Penn says, you would have had to make do with a textual summary. But a text-based summary requires a transcript, and these are time-consuming if done manually and typically error-riddled when done by a computer program. Even if speech-recognition programs were error-free, a perfect transcript would hold little appeal, given that human speech is full of “ums” and “ahs,” sentences that seem to change gear in the middle, and strings of words and phrases that generally flout the rules of grammar. A condensed audio file, in contrast, still conveys the key message of a given speech, Penn says, without sounding jarring to the ear.
Potential demand for the software could come from any field where short summaries of spoken-word content are required – such as businesses that need brief accounts of speeches or news broadcasts; students who need summaries of lectures at exam time; or even government security agencies on the lookout for signs of criminal activity in phone conversations.
The next step, Penn says, will be to compare computer-generated summaries with those generated by humans, to see how well they match up – bearing in mind that human listeners might not agree with each other about what the most important points in a given speech were. Collaborations with colleagues in psychology are a possibility. “We need to consider what artificial intelligence is all about,” he says.
– Dan Falk
DNA and Diet
Why can some people drink all the coffee they want and others can’t? The answer may be genetic
Reducing your salt intake could save your life – or imperil it. It depends on your genes. Same thing with coffee: four cups a day could be divine for me but dangerous for you. How can we know? At the moment, it isn’t easy. But that’s something Dr. Ahmed El-Sohemy, a professor in the Faculty of Medicine, is working to change.
El-Sohemy holds the Canada Research Chair in Nutrigenomics, which is a branch of nutritional science that explores how the nutrients we consume interact with our genes to affect our health. His research has bolstered the idea that our genetic makeup determines in part how we react to certain foods. In 2006, for instance, El-Sohemy and his colleagues published a startling paper in the Journal of the American Medical Association about coffee drinkers. People with a particular gene variant metabolize caffeine slowly. So whereas genetically “fast” metabolizers can drink all the coffee they want with impunity, slowpokes under the age of 50 have a four-fold increased risk of heart attack when they imbibe four or more cups per day. And, lest you think you can tell your genotype by whether the dark stuff keeps you up at night, that effect is totally unrelated, he says.
This is the sort of useful genetic detail we’d all like to know about ourselves. Luckily, El-Sohemy and others are at work on a personalized nutrigenomics test kit. In addition to pinpointing our caffeine risk, the test will reveal whether we will be deficient in vitamin C if we don’t take the recommended daily allowance of 75 to 90 milligrams and whether we should curb our salt habit. Guidelines tend to focus on the upper and lower limits, he points out, but not the individual: “You are just one point in the range,” he says.
– Alison Motluk
Restoring a Way of Life
Did the settlers take more than land from North America’s indigenous peoples?
When one person is wronged by another, our sense of fairness demands that the injustice be corrected. If someone steals your car, at the very least you deserve to get your car back. But when it comes to historical injustices committed by one group against another – say, European settlers against indigenous North Americans – there’s little agreement about what to do.
One influential argument is that historical injustices can’t really be redressed. Jeremy Waldron, a professor of law and philosophy at the New York University School of Law, has argued that historic claims from past injustices weaken as time passes. In the case of indigenous peoples, Waldron contends that the descendants of the European settlers have gradually built a legitimate claim to the land that their ancestors took.
Douglas Sanderson, a U of T law professor studying the issue of justice for groups that have suffered historical wrongs, disagrees. He says claims to justice don’t fade because of the passing of time, in part because today’s indigenous people are still suffering – the injustice is ongoing. Nor can the injustice be corrected simply by restoring stolen land.
“My view is that what settler people took from indigenous people was the capacity to live lives that are meaningful to indigenous people as indigenous people,” says Sanderson, who is a member of the Opaskwayak Cree Nation.
He imagines what life would be like for modern indigenous people who had maintained their independence even as settler society grew up around them. They would drive cars, use roads, live in houses and work for wages. But their institutions – government, schools, health care – would affirm their traditional cultures. For example, a Cree child-welfare system would place neglected children in the extended family context of the clan system, rather than in foster homes with strangers. Leaders might be elected through public consensus, rather than secret ballot. A right to vote might be tied to a traditional coming-of-age ceremony, rather than simply a birthday.
Justice means allowing modern indigenous people to live in the way they would have if the injustices had never been done in the first place. Sanderson’s vision would require a change in Canadian laws to give indigenous people more legal, political and cultural autonomy.
“I have to believe that at some point down the road there’s some set of policies where in the end settler people and indigenous people can look at each other across the table and say, ‘OK, we’re even,’” says Sanderson. “There just has to be a way of getting there.”
– Kurt Kleiner
Plants and bacteria do a pretty good job of cleaning up our noxious messes. But which of these organisms are most effective? And under what conditions?
Humans have been releasing chemicals into the environment for years, and the Earth does a fairly good job of breaking these down over time. But what if we could speed up the natural process? What if we could determine precisely which bacteria and plants eliminated toxins such as PCBs and pesticides from the environment the fastest?
That’s the ultimate goal of Roberta Fulthorpe, a professor in the department of physical and environmental science at U of T Scarborough. So far, researchers have only studied the way bacteria take apart toxins in contaminated areas. But Fulthorpe says there are possibly hundreds of species of bacteria living in uncontaminated soil that scientists have never encountered. Her research aims to uncover some of these.
Fulthorpe has previously studied the genetic diversity of bacteria in areas contaminated by pulp-and-paper waste-treatment systems. She also hopes to study plant tissues, which contain bacteria that can aid in breaking down toxins. “We know it’s common for plant tissue to have non-harmful bacteria, but we don’t know what they do,” she says.
At the moment, it takes many years for natural processes to break down organic pollutants. So when contaminated land is being considered for residential or commercial uses, developers are often unwilling to wait. They simply scoop up the toxic soil and ship it somewhere else, or use other chemicals to scrub the more toxic ones away. Finding a faster way to clean up the soil naturally would have plenty of practical uses, says Fulthorpe, and lead to a cleaner habitat for all.
– Sarah Boesveld
Solid oxide fuel cells are more reliable than wind and more efficient than solar. Now if only they were cheaper . . .
As countries around the world try to cut their greenhouse gas emissions while still satisfying a growing demand for electricity, interest in wind and solar energy has soared. But each has its challenges: energy from the wind is unreliable and solar energy is inefficient. Most photovoltaic cells convert only 15 per cent of the light energy that falls on them to electricity, which limits the amount of power that can be produced within a small space, such as a rooftop.
Olivera Kesler, a professor of mechanical and industrial engineering, is conducting research into solid oxide fuel cells – an alternative energy source that produces electricity using a variety of naturally occurring gases, such as methane and propane. Solid oxide fuel cells do not make sulphur dioxide or nitrogen oxide – common air pollutants – and are four times as efficient as photovoltaic cells at converting energy to electricity. They also use half as much fuel and create half as much carbon dioxide as coal-fired generators (to produce the same amount of electricity).
But some technical challenges must be solved before solid oxide fuel cells will be adopted widely. The cells must be made cheaper to produce and more durable. To accomplish this, Kesler and her students are creating supports for the cells made from stainless steel and fabricating new fuel cell structures with the aim of maximizing electricity production while lowering cost.
The lab is working with a Canadian industrial partner to see if the fuel cell structures can be developed and marketed to companies that buy equipment to make electricity. Eventually, they may be used in homes, industrial sites – and even cars.
– Sarah Boesveld
Making Drugs Safer
By identifying all the proteins a drug acts on in yeast, researchers may be able to better predict unwanted side-effects in humans
Most drugs on the market were discovered serendipitously. And even ones we use every day aren’t well understood. Pharmaceutical companies tend to know a lot about how a drug affects the particular protein it targets. But the human body has some 20,000 genes, each encoding its own protein. They may know little about what other proteins the drug affects.
Guri Giaever, a chemical geneticist at the Donnelly Centre for Cellular and Biomolecular Research, has devised a way to figure that out – using yeast. The yeast genome was sequenced in 1996. It was the first organism to have every letter of its DNA instruction manual spelled out. Scientists immediately realized, though, that it wasn’t enough to know what the genes were: they had to know what they did. So 16 labs around the world (Giaever worked in the lead one) collaborated to systematically knock out each of the 6,000 genes one at a time, to understand their functions.
Using these “knockout” yeast strains, Giaever developed a unique platform for testing drugs in live yeast. “We can study a drug’s effects on all the proteins at the same time,” she says. True, it’s not a human, but roughly 70 per cent of the essential genes have a strong human homologue. “It’s humbling how many genes we share,” she says.
Giaever’s system works by growing all 6,000 knockout strains together, bathing them in the drug molecule of interest, then seeing which cells thrive and which do poorly. Each strain has a unique “bar code,” made of a 20-base-pair string of DNA, which makes it possible for the researchers to separate the flourishing cells from the floundering.
One way the system is used is to help drug companies better understand how their own drugs work. For a drug that requires regulatory approval, for instance, a company might need information on what is causing an unwanted side-effect. Giaever’s system can identify other yeast proteins affected by the drug and thus throw light on the mechanism behind the undesired effect.
Giaever and her collaborators are also screening drugs that have been approved for use to see if they can be “repurposed.” They identify all the proteins the drug acts on, and then make that information available to researchers who might see how that action could help combat disease. There’s a lot of potential. All the drugs out there, she says, only target about 300 proteins out of 20,000 or so produced in humans, leaving plenty more to be investigated.
– Alison Motluk
An Electronic Veil
We routinely give away more information about ourselves than we need to. Digital identification could help us keep personal details under our control
Showing identification to prove who we are – or that we have the credentials to engage in a particular activity – is something we do almost every day. But in showing our ID, we usually reveal more about ourselves than we need to, says Andrew Clement, a professor in the Faculty of Information. A liquor-store clerk might demand to see a driver’s license for proof of age, but all he really needs to know in most cases is the year of birth. Similarly, a health-club supervisor only needs to know that the person wanting to enter the facility is a member in good standing. She doesn’t need to know the member’s name.
So far, people generally have been willing to accept this kind of encroachment on their privacy in exchange for convenience. But Clement is concerned that as digital identification becomes more commonplace, the information we provide will be stored in databases and used in ways that we didn’t anticipate – or, worse, aren’t permitted by law. He is researching a way for people to identify themselves digitally that would reveal only the minimum amount of information required, without sacrificing convenience. This principle, called “data minimization,” is fundamental to Canada’s privacy laws, but is not broadly enforced, he says.
He holds up his smartphone and notes that he could display a credential on the screen. Ideally, two things would happen at this point, he says: the person showing the ID would wirelessly transmit only the minimum information that’s required to the organization; and the organization would be able to establish with a high degree of certainty that the credential is authentic.
Clement explains that authentic electronic credentials would be digitally “signed” by the agency that issues them. Someone wishing to create a fake ID would have to decode the agency’s digital signature – a challenge so mathematically complex as to be impossible, he says.
Under this system, organizations would have to make an electronic request for the specific information they need – year of birth, photo, address – and the basis for why they need it before a person’s smartphone or other digital device would send it. The request would be logged on the individual’s device and could be reviewed later to ensure that it complied with privacy legislation, Clement says.
Clement has no plan to set up this new digital ID system himself beyond developing educational prototypes. But he would like to see the idea gain traction in the marketplace. “People almost always provide organizations with the information they ask for because they don’t want to interrupt the transaction,” he says. “Digital credentials could help rebalance this in the public’s favour.”
– Scott Anderson
Education for All
Why do some immigrant groups fare better than others in school?
Canada has an official policy of multiculturalism, but the country’s largest school board might not be meeting the needs of children of newcomers – at least in the case of one significant ethnic group. The dropout rate for first-generation Latin American students and Spanish-speaking youth is 37 per cent, almost double the Toronto average.
That’s cause for concern. Why do children of some immigrant groups fare better than others in the Toronto school system? And how can the system be improved to meet the needs of newcomers from all parts of the world?
Conventional wisdom says cultures that place a low value on education are at least partly to blame for high dropout rates among some student groups. But in interviews with Latin American students, Professor Ruben Gaztambide-Fernandez of the Centre for Urban Schooling at OISE found precisely the opposite to be true: Spanish-speaking students are highly aware that getting a good education and mastering the English language are crucial for their future. “The situation that leads them to leave school really has nothing to do with how committed they are to school,” he says.
What administrators should be asking is what conditions are making it difficult for some groups, such as Latin American students, to stay in school. Gaztambide-Fernandez points to three significant issues. First, cutbacks in the 1990s left school boards with less money for ESL instruction. Students are now slotted into one of three ESL levels, meaning that many are placed in a class inappropriate to their skills. In some worst-case scenarios, advanced students are placed in beginner classes because the school doesn’t have the resources to offer more than one level of instruction.
Second, Latin American students report feeling subject to prejudice from teachers and their peers, and believe that the curriculum “ignores” their culture and history. Better teacher education can help, says Gaztambide-Fernandez, but so can asking students to share stories about their own history and culture with their class. This tells students that their culture is valued, and gives them responsibility for shaping their peers’ views, he says.
Finally, many immigrant students work in the evenings to help support their family. They have no choice but to sacrifice academic achievement for economic security. As well, some students might choose an academic path that is less appealing to them if it holds out the promise of being able to obtain a job sooner. The question for schools, says Gaztambide- Fernandez, is how to support students so their choices aren’t dictated solely by their social and economic circumstances.
Ultimately, ensuring that the education system is meeting the needs of new Canadians will ensure a brighter economic future for everyone. “If we want multiculturalism to be a strength of Canadian society, then we have to learn how to take advantage of the differences immigrants bring,” he says.
– Scott Anderson
What Keeps People Honest?
We seem to balance a desire for personal gain against a desire to see ourselves as basically good
The economic human – perfectly rational, perfectly informed and perfectly self-interested – is a useful fiction for studying how economies work. Our behaviour is rational, informed and self-interested enough that economic models based on those assumptions work pretty well.
But not perfectly. People make decisions for all sorts of reasons, including social and emotional ones. Some of the most interesting advances in economics are in a field called behavioural economics, which looks more closely at the psychology of actual humans making actual economic decisions. Inspired by fear, fairness, social pressure, and other not-entirely-rational factors, real people make decisions that economic humans would simply not understand.
Nina Mazar, a professor of marketing at the Rotman School of Management, is especially interested in dishonesty. Her work examines a seeming paradox – people cheat more than they would if they were strictly moral beings, but not nearly as much as if they were strictly economic ones.
In one study by Mazar, people were offered 50 cents for each arithmetic question they answered correctly. Given the chance to cheat (by reporting their own scores rather than handing in their papers) most goosed their scores by a few points. But almost no one cheated to the maximum level possible, even when they knew they wouldn’t be caught.
Mazar says that people seem to balance their desire for personal gain against their desire to continue to see themselves as basically good. They cheat as much as they can without being forced to revise their self-image as honest people. “You can be a little bit dishonest and benefit a little bit from these temptations, but you don’t have to change your view of yourself,” she says.
But in the same study, if she asked subjects to write down as many of the Ten Commandments as they could remember before completing the task, cheating disappeared. The same held true if she asked them to sign an honour code. Mazar says that simply calling people’s attention to their own standards – to their image of themselves as honest – helps reduce cheating.
Mazar has talked to the Canadian Revenue Agency about her research, which could lead to tax forms that are designed to minimize cheating. Eventually, she thinks, businesses might use insights from the work to deter employee and customer theft. But she warns that it’s still not clear how insights from the lab stand up in the real world. “The world outside is much more complex than the lab,” she says.
– Kurt Kleiner
Memory and Aging
Problems with the brain chemical acetylcholine could be partly responsible for cognitive decline
Age-related dementia isn’t just a personal tragedy. As the global population ages, increasing resources will have to go toward caring for people suffering from Alzheimer’s disease and other dementias. The number of sufferers worldwide is expected to surpass 65 million by 2030, and the associated annual cost will exceed $1 trillion.
In the case of Alzheimer’s disease, much attention has been paid to the formation of amyloid plaques and protein tangles in the brain that might interfere with cognitive function. But Eve De Rosa is exploring another possible cause. The psychology professor is investigating the key role that a brain chemical called acetylcholine plays in learning and attention, and how problems with the acetylcholine system might also contribute to cognitive decline.
Acetylcholine levels dwindle during normal aging, and are especially affected in Alzheimer’s patients. Brain receptors that respond to the neurochemical also stop doing their job. One of acetylcholine’s functions is to enhance perceptual attention – our ability to pay attention to important stimuli and tune out distracting ones without having to think about it. For example, we automatically filter out background noise while listening to someone speak.
“It’s been shown in the literature over and over again that elderly people are susceptible to distraction by things that are irrelevant to what they should be doing,” De Rosa says. She thinks the memory loss of dementia might be explained by a failure to filter out irrelevant information, which means important details never make it into memory in the first place. De Rosa has shown that in rats a lack of acetylcholine doesn’t interfere with the ability to access memories that are already established. Instead, it interferes with efficient formation of memories.
In a recent experiment with humans she put young people and older people in a functional MRI machine, and had them look at pictures of overlapping faces and places. She asked them to pay attention only to the faces. In young people, a brain region responsible for responding to faces was active during the task, while a brain region responsible for responding to places was not. But in older people, both regions were active; they couldn’t filter out the irrelevant information. De Rosa says that acetylcholine is unlikely to be the whole story of age-related dementia. But she thinks it’s an important component, and understanding it could lead to effective treatments.
– Kurt Kleiner