Collaborations

Humans today demonstrate sleep patterns inherited from their hunter-gatherer ancestors, says new research by David Samson, an assistant professor of anthropology at the University of Toronto Mississauga.

In their paper, published in the latest issue of Proceedings B, Samson and his colleagues from Duke University, the University of Nevada Las Vegas and the University of Dar es Salaam, Tanzania, are the first researchers to confirm that the 1966 “sentinel theory” is applicable to humans. The theory suggests that among group-dwelling animals, there should be mechanisms that ensure various members of the group are awake at almost all times, in order to protect others who are in more vulnerable states (such as being asleep).

In other words, due to natural variation in sleep timing, members of the group serve as sentinels, alert to potential dangers, such as attacks from other hostile groups or animals.

“This hypothesis has never been tested in humans before,” says Samson.

Researchers travelled to rural Tanzania to study the sleep patterns of the hunter-gatherer Hadza tribe (photo courtesy of David Samson)

The research is making headlines around the world.

Read The Guardian

Although most human sleep research to date has taken place in laboratories under artificial conditions, Samson and his colleagues took their equipment and tests to rural Tanzania, where the hunter-gatherer Hadza tribe “lives in the same savannah grasslands that our ancestors had to overcome to adapt,” Samson says. With very little – if any – aid from industrially-produced equipment or tools, the Hadza hunt and gather on foot using bows, digging sticks and axes.

“It’s the best current window into our evolution,” says Samson (pictured below).

Using actigraphs, which are Fitbit-like, wrist-worn devices that measure light and activity, the researchers discovered that among the 33 men and women studied, there were only 18 minutes out of 13,000 total minutes that everyone in the group was asleep. In addition, they found that 40 per cent of the group was awake at any given time.

The researchers also determined that variation in chronotype – defined as the individual propensity to sleep at a particular time during a 24-hour period – was driven by age. While the younger Hadza tended to be “owls” who stayed up late – relatively standard during the courtship and mating years – the elders tended toward “lark” behavior, waking early and perhaps sleeping poorly.

“Researchers have theorized that one of the reasons grandparents live so long past their reproductive years is that their function is to take care of grandchildren,” Samson says. “Our hypothesis is that their lark behaviour and shorter sleep times serve a function: the elders serve as sentinels at the times of day when others are sleeping. Therefore, it’s important to have people of all ages in any population.”

Additionally, the researchers have discovered the Hadza to be characterized by flexible sleep patterns, demonstrated by their ability to respond to different ecological, social and technological factors influencing sleep throughout a 24-hour period. This behaviour is similar to that found in Western populations. For example, people in North America adjust sleeping in a new environment, such as a hotel room, by shifting to a greater reliance on sleep in one brain hemisphere and increasing the other hemisphere’s sensitivity to deviant stimuli such as noise or light.

Samson also notes that it may not be as necessary to view sleep variation with the concern it receives in Western societies.

“While we tend to look at every deviation from the normal sleep pattern as a problem, it may just be part of human variation,” he says. “We are seeking to fill in a piece of the evolutionary puzzle.”

Global Health Summit: improving health through innovative city design

sgupta — Thu, 30 Oct 2014 12:21:35 +0000

Global Health Summit: improving health through innovative city design sgupta Thu, 10/30/2014 - 08:21

Elaine Smith

Author legacy

Elaine Smith

Topic

Global Lens

Top Stories

Health

Dalla Lana School of Public Health

Collaborations

Global

As more and more of the world’s population migrates to cities to seek employment, health-care professionals are thinking about ways to ensure that those cities provide healthy environments for large numbers of people.

The Global Health Summit, slated for November 3 to 5 at the University of Toronto’s Dalla Lana School of Public Health, will bring together experts from diverse fields, including architecture, business, medicine, engineering and public health, to explore ways to design, build or change cities to provide residents with the most equitable opportunities for good health.

“A healthy city is one in that promotes health equity for all citizens,” said Patricia O’Campo, a professor at the Dalla Lana School and director of the Centre for Research on Inner City Health at St. Michael’s Hospital.

“Achieving health equity goes beyond equitable access to health care,” continued O’Campo, who co-leads the School’s healthier cities and communities hub with Professor Blake Poland. “We also need healthy urban infrastructure, safe recreation, access to good jobs, and an end to violence, racism, isolation and community disenfranchisement.”

Anita McGahan, associate dean of research at the Rotman School of Management and a contributor to Innovating for the Global South (U of T Press), said, “We still deliver health care at the county or city level, but inequality and human suffering are not city- or country-specific; they can have implications all over the world.”

McGahan believes that resilience, “the ability to adapt to whatever circumstances you’re in and the cards you’re dealt, has more of an impact on health than almost any other factor.”

Poland, another proponent of resilience, noted that “we tend to assume that ‘vulnerable groups’ are most lacking in resilience, but it is also true that marginalized groups deal with stress, hardship and loss on a more regular basis,” often in terms of inadequate funds for shelter or food, for example.

He said equity still gets short shrift in the resilience literature.

“Inequity dwarfs diabetes or smoking as a determinant of health,” he said. “We tend to look at ameliorative programming, rather than asking what is producing and reproducing these inequities in the first place.”

Poland noted that it is also important to look at the emerging threats to health equity, such as the ecosystem and resource depletion.

“The ecological determinants of health are poised to succeed the social determinants in relative importance in the coming decades,” he said. “We need to pay more attention to environmental degradation and climate change. With more uncertainty, we will be hit with surprises – like hurricanes or flooding – and we need to think about our systems’ responses.”

Stephen Verderber, a professor at the Daniels Faculty of Architecture who lived through Hurricane Katrina in New Orleans, is looking at what cities can do to heal themselves when they absorb blows dealt by environmental events, such as earthquakes, hurricanes or floods.

“After the Christmas ice storm in Toronto, it took longer than expected for the city to bounce back,” he said. “We need to consider how the built environment can provide prosthetic support, for instance with hospitals, clinics and other portable facilities brought into the disaster zone.”

McGahan said she hopes the discussion of these issues at the Global Health Summit and their implications will “affect how we teach about health and develop public policy.”

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U of T researchers shed new light on biology underlying schizophrenia

sgupta — Wed, 23 Jul 2014 09:10:42 +0000

U of T researchers shed new light on biology underlying schizophrenia sgupta Wed, 07/23/2014 - 05:10

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This study is "a major advance in understanding the genetic basis of brain functioning in schizophrenia,” says Professor Jo Knight (photo courtesy CAMH)

Heidi Singer

Author legacy

Heidi Singer

Topic

Subheadline

Genes, pathways identified by international team could inform new approaches to treatment

It's the largest genomic study published on any psychiatric disorder to date.

As part of a multinational, collaborative effort, researchers from the University of Toronto and the Centre for Addiction and Mental Health (CAMH) have helped identify more than 100 locations in the human genome associated with the risk of developing schizophrenia.

The findings, published online in Nature, point to biological mechanisms and pathways that may underlie schizophrenia, and could lead to new approaches to treating the disorder, which has seen little innovation in drug development in more than 60 years.

“Large collaborative efforts such as this one are needed to identify genes that influence complex disorders,” said Jo Knight, professor of Psychiatry at U of T’s Faculty of Medicine, CAMH senior scientist and the Joanne Murphy Professor in Behavioural Science.

“The result is a major advance in understanding the genetic basis of brain functioning in schizophrenia,” said Knight, who spearheaded CAMH’s involvement in the project.

Schizophrenia, a debilitating mental illness that affects approximately one out of every 100 people worldwide, is characterized by hallucinations, delusions, and disordered thinking, and often emerges in the teens and early 20s. Its lifetime impact on individuals and society is high, both in terms of direct health-care and other costs, as well as lost productivity and unemployment, which costs an estimated $6.85 billion a year in Canada.

Medications now on the market treat only one of the symptoms of the illness (psychosis), and there are no effective treatments for the debilitating cognitive symptoms of schizophrenia. In part, treatment options are limited because the biological mechanisms underlying schizophrenia have not been understood.

Recent research focusing on the genetic underpinnings of schizophrenia has revealed the complexity of the illness. Evidence suggests that it is caused by the combined effects of many genes, and roughly two dozen genomic regions have been found to be associated with schizophrenia.

The new study confirms those earlier findings, and expands our understanding of the genetic basis of schizophrenia and its underlying biology. In the genome-wide association study (GWAS) published in Nature, the authors looked at 36,989 genetic samples from schizophrenia patients and 113,075 healthy volunteers and found 108 specific locations in the human genome associated with risk for schizophrenia. Eighty-three of those loci had not previously been linked to the illness.

The study was conducted within CAMH’s Campbell Family Mental Health Research Institute. Dr. James Kennedy, a professor in the Department of Psychiatry, and alumnus Clement Zai, a CAMH postdoctoral fellow, were also on the study team.

The study implicates genes expressed in brain tissue, particularly those related to the functioning of brain cells (neurons) and of the channels enabling chemical and electrical signaling between neurons (synapses). These include genes that are active in pathways controlling synaptic plasticity – a function essential to learning and memory – and pathways governing activity in the target cell receiving signals.

Additionally, the researchers found a smaller number of genes associated with schizophrenia that are active in the immune system. This discovery offers some support for a previously hypothesized link between schizophrenia and immunological processes. The study also found an association between the illness and the region of the genome that holds DRD2 – the gene that produces the dopamine receptor targeted by all approved medications for schizophrenia – suggesting that other loci uncovered in the study may point to additional therapeutic targets.

“The fact that we were able to detect genetic risk factors on this massive scale shows that schizophrenia can be tackled by the same approaches that have already transformed our understanding of other diseases,” said senior author Michael O’Donovan, deputy director of the MRC Centre for Neuropsychiatric Genetics and Genomics at Cardiff University School of Medicine.

“The wealth of new findings has the potential to kick-start the development of new treatments in schizophrenia, a process which has stalled for the last 60 years.”

The study is the result of several years of work by the Schizophrenia Working Group of the Psychiatric Genomics Consortium (PGC), an international, multi-institutional collaboration founded in 2007 to conduct broad-scale analyses of genetic data for psychiatric disease. A total of 55 datasets from more than 40 different contributors, including CAMH, was needed to conduct the analysis.

The samples used in this study represent all of the genotyped datasets for schizophrenia that the consortium has amassed to date. The PGC is currently genotyping new samples to further study schizophrenia and additional psychiatric diseases, including autism and bipolar disorder.

Core funding for the Psychiatric Genomics Consortium comes from the U.S. National Institute of Mental Health (NIMH), along with numerous grants from governmental and charitable organizations, as well as philanthropic donations.The Canadian contribution was funded in part by the Canadian Institutes of Health Research grant MOP-115097.

Heidi Singer is a writer with the Faculty of Medicine at the University of Toronto.

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Helping Botswana doctors build surgical capacity

sgupta — Mon, 21 Jul 2014 11:39:15 +0000

Helping Botswana doctors build surgical capacity sgupta Mon, 07/21/2014 - 07:39

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Surgeons at the Princess Marina Hospital in Gaborone, Botswana, perform a laparoscopic procedure (photo courtesy Faculty of Medicine)

Vitaly Kazakov

Author legacy

Vitaly Kazakov

Topic

Subheadline

"Our results are now equal to, and in some areas, even better than those of our North American partners”

When Georges Azzie first arrived in Gaborone, Botswana, he was the only paediatric surgeon in that country. Not anymore.

Over the last decade, the University of Toronto associate professor has been spending three months a year in Gaborone performing surgeries and working with colleagues to address Botswana’s surgical care and education needs.

Azzie, who is an associate professor in the Department of Surgery and a surgeon at the Hospital for Sick Children, explains that a lack of surgeons, nurses and technical staff is a major health care challenge in Botswana. There are just a few general surgeons serving the country’s two million people, which means training Botswana’s next generation of health care providers is critical.

In 2005, two of the country’s hospitals had equipment for minimal access surgery, but lacked qualified surgeons who could use it. At the request of local officials, Azzie and his U of T partners helped develop a training program to increase the number of specialists in this area. Assistant Professor Allan Okrainec, also of the Department of Surgery, came up with the idea for cost-effective mentorship and improving skills. Using telesimulation, they taught 20 Botswana doctors the fundamentals of a minimally invasive surgical technique called laparoscopy.

Dr. Alemayehu Ginbo Bedada is one of the physicians who received that training. He works at the Princess Marina Hospital in Gaborone and teaches at the University of Botswana’s School of Medicine. He was recently in Toronto to present a study that describes a model for establishing a contextually appropriate laparoscopic program in resource-restricted environments.

Bedada’s paper will be published in the Annals of Surgery this year. The study, co-authored with Azzie and a group of local researchers, highlights the success of the Botswana’s program: improved patient outcomes, increased confidence among local surgeons and the fact that it is fully financed by their Ministry of Health.

“The beauty of our program is that we do not rely on external funding,” says Bedada. “Our ability to use only the government’s budget ensures its sustainability. We learned to improvise with the resources we have to achieve the best outcome for our patients. Our results are now equal to, and in some areas, even better than those of our North American partners.”

Bedada and Azzie also focus on the future: they hope to help train a new generation of Batswana surgeons. Two postgraduate students are already training in Cape Town, South Africa, while Dr. Balisi Bakanisi will be completing his general surgical training at U of T in 2015. Four other local medical care specialists are preparing for international training in surgery soon.

“One of the unique things Dr. Azzie did here is pushing for opportunities for local doctors to get advanced surgical training. Young doctors like Balisi are going to come back here and take over from us,” says Bedada.

Azzie’s international experience is extensive. His recipe for building productive, long-term international partnerships is the same wherever he goes: understanding, respecting and empowering your colleagues.

Another key to the success of Botswana surgical care and education initiatives is the team’s ability to work towards the same goal despite different backgrounds. Bedada, an Ethiopian, and his colleagues, who come from Egypt, Uganda, India, Canada, Botswana and other countries, all learn from each other and share the same dedication to their patients in Botswana.

“Longevity of the partnership, and the respect and thoughtfulness of everyone involved in it are the reasons the laparoscopic surgery program succeeded,” says Azzie. “We at the University of Toronto can now speak with significant authority on what it takes to establish a long-term relationship, how to sustain it and grow it further.”

The partnership also helped a number of U of T medical students learn about global surgery and international health in Botswana. In spring 2014, Dr. Stephanie Dreckmann spent six weeks in Gaborone doing a general surgery selective under the supervision of Azzie and Bedada. This experience helped Dreckmann hone her skills, expanded her medical expertise and gave her the chance to serve in management and health advocacy roles within a resource limited setting.

“I’ve been lucky to come along at a time where there is a ground swell of interest in global surgery and international health,” says Azzie. “I have benefitted from the guidance and the expertise of people who are ‘giants’ in this field, and I would like to pass my experience to others. There is a huge potential to expand our collaboration in Botswana to other kinds of surgical care and education.”

Vitaly Kazakov is a writer with the Faculty of Medicine at the University of Toronto.

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The benefit of prolonged heart monitoring after unexplained strokes: New England Journal of Medicine

sgupta — Thu, 26 Jun 2014 12:45:00 +0000

The benefit of prolonged heart monitoring after unexplained strokes: New England Journal of Medicine sgupta Thu, 06/26/2014 - 08:45

Cutline

Dr. David Gladstone led the EMBRACE trial (photo by Doug Nicholson/Media Source)

Topic

St. Michael's Hospital

Subheadline

Prevention of stroke due to atrial fibrillation “global health issue”

A major 16-centre Canadian study, published June 26 in the prestigious New England Journal of Medicine, shows the benefit of prolonged heart monitoring to diagnose silent, but dangerous, irregular heart rhythms in people who have unexplained strokes.

Findings of the three-year EMBRACE trial represent “an important advance” in determining the cause of up to a third of ischemic strokes, which result from blood clots to the brain, writes Cornell University neurologist Dr. Hooman Kamel in an editorial accompanying the study.

“The results . . . indicate that prolonged monitoring of heart rhythm should now become part of the standard care of patients with cryptogenic (unexplained) stroke,” Dr. Kamel writes.

Led by Dr. David Gladstone, an associate professor in the Department of Medicine at the University of Toronto and clinician-scientist at Sunnybrook Research Institute, the EMBRACE trial followed 572 patients ages 55 and older with a recent stroke or TIA (transient ischemic attack) and in whom standard diagnostic tests (including conventional heart monitoring for at least 24 hours) failed to detect the cause.

The study found that, by monitoring patients at home with a new chest electrode belt for 30 consecutive days, atrial fibrillation (irregular heart rhythm) was detected in 16 per cent of patients, as compared with the standard 24-hour monitoring which found the arrhythmia in only three per cent of patients.

Prevention of stroke due to atrial fibrillation is “a global public health issue,” according to the Canadian Stroke Network-funded study, the largest clinical trial of heart monitoring in stroke patients. Atrial fibrillation is known to cause some of the most disabling, deadliest, and most costly types of strokes.

However, the challenge has been that atrial fibrillation is often hard to diagnose because the irregular heartbeat may last for just a few minutes at a time, after which the heart reverts back to its normal rhythm. Unless an individual is wearing a heart monitor at the time it occurs, the diagnosis is usually missed. In practice, stroke patients have traditionally received only short-duration heart monitoring (e.g. for 24 hours) to screen for atrial fibrillation – a strategy that now appears inadequate according to the study’s findings.

“The harder we look with more intensive heart monitoring, the greater the chance of finding this hidden risk factor – it’s like medical detective work,” said Gladstone, whose research was supported by the Heart and Stroke Foundation (HSF) and the HSF Canadian Partnership for Stroke Recovery.

In the study, enhanced detection of atrial fibrillation led to significantly more patients being prescribed stronger anti-clotting medications to prevent recurrent strokes. Atrial fibrillation is a risk factor for stroke because it can promote the formation of blood clots in the heart that can travel to the brain. It is important to detect because it can be effectively treated with certain anti-clotting medications, which cut the risk of clots and strokes by two-thirds or more.

Gladstone has already begun implementing the study’s findings in practice by offering prolonged heart monitoring to patients at Sunnybrook Health Sciences Centre, where he directs the Regional Stroke Prevention Clinic.

“With improved detection and treatment of atrial fibrillation, the hope is that many more strokes and deaths will be prevented,” Gladstone said. The New England Journal of Medicine published a second U.S-based study on prolonged monitoring this month, called CRYSTAL AF, which further supported the practice change.

The EMBRACE trial was conducted by investigators of the Canadian Stroke Consortium and coordinated at the Li Ka Shing Knowledge Institute of St. Michael’s Hospital in Toronto.

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New fossil find shows how jaws evolved in tiny, ancient fish ancestor

sgupta — Thu, 12 Jun 2014 16:57:25 +0000

New fossil find shows how jaws evolved in tiny, ancient fish ancestor sgupta Thu, 06/12/2014 - 12:57

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Metaspriggina walcotti as it might have looked in its environment. (Reconstruction by Marianne Collins. © Conway Morris and Caron.)

Sean Bettam

Author legacy

Sean Bettam

Topic

Faculty of Arts & Science

Research

Global

Top Stories

Subheadline

Metaspriggina discovery pinpoints the origin of jaws in vertebrates

Jean-Bernard Caron of the Departments of Earth Sciences and Ecology & Evolutionary Biology at the University of Toronto, has uncovered a remarkable piece in the puzzle of the evolution of vertebrates.

The fossilised fish, known as Metaspriggina, dates back to the Cambrian period (about 505 million years ago). It shows pairs of exceptionally well-preserved arches near the front of its body. The first of these pairs, closest to the head, eventually led to the evolution of jaws in vertebrates, the first time this feature has been seen so early in the fossil record.

“Fish fossils from the Cambrian period are very rare and usually poorly preserved," said Caron, leader of the 2012 expeditions that recovered the specimens.

“This new discovery shows in unprecedented detail how some of the earliest vertebrates developed – the starting point of a story which led to animals such as later fish species, but also dinosaurs and mammals such as horses and even humans,” said Caron, who is also curator of invertebrate palaeontology at the Royal Ontario Museum.

The findings are published in the June 11 edition of the journal Nature.

Fossils of Metaspriggina were recovered from several locations by Caron (pictured at left) and his team including the Burgess Shale site in Canada’s Rocky Mountains, one of the richest Cambrian fossil deposits in the world. These fossils shed new light on the Cambrian ‘explosion’, a period of rapid evolution starting around 540 million years ago, when most major animal phyla originated. (photo by Jean-Bernard Caron © ROM)

Previously, only two incomplete specimens of Metaspriggina had been identified. In 2012, Caron’s group collected 44 new Burgess Shale fossils near Marble Canyon in Kootenay National Park in British Columbia. Caron along with palaeontologist Simon Conway Morris of the University of Cambridge’s Department of Earth Sciences used these fossils, as well as several more specimens from the eastern United States, to reclassify Metaspriggina as one of the first vertebrates.

The fossils also show how a series of rod-like structures, known as the gill or branchial arches, were arranged in the earliest vertebrates. These arches have long been known to have played a key role in the evolution of vertebrates, including the origin of jaws, and some of the tiny bones in the ear which transmit sound in mammals. Until now, however, a lack of quality fossils has meant that the arrangement of these arches in the first vertebrates had been hypothetical.

“Vertebrates first appear in the fossil record slightly earlier than these finds, but pinpointing exactly how they developed is difficult,” said Caron. “This is because fossils of such animals are rare, incomplete and open to varying interpretations, as they show soft tissues which are difficult to identify with complete certainty.”

The new fossils of Metaspriggina are remarkably well-preserved. The arrangement of the muscles shows these fish were active swimmers, not unlike a trout, and the animals saw the world through a pair of large eyes and sensed their surrounding environment with nasal structures.

“The detail in this Metaspriggina fossil is stunning,” said Conway Morris, lead author of the Nature study. “Even the eyes are beautifully preserved and clearly evident.”

But it is the branchial arches which makes this discovery so important. Previously, they were thought to exist as a series of single arches, but Metaspriggina now shows that they in fact existed in pairs. The anterior-most pair of arches is also slightly thicker than the remainder, and this subtle distinction may be the very first step in an evolutionary transformation that in due course led to the appearance of the jaw.

“Once the jaws have developed, the whole world opens,” said Conway Morris. “Having a hypothetical model swim into the fossil record like this is incredibly gratifying.”

“Obviously jawed fish came later, but this is like a starting post – everything is there and ready to go,” said Caron. “This is a major discovery that will play a key role in understanding our own origins.

"We also believe that Marble Canyon, the new Burgess Shale locality where many of the fossils were found, has fantastic potential for revealing key insights into the early evolution of many other animal groups during this crucial time in the history of life.”

Sean Bettam is a writer with the Faculty of Arts & Science at the University of Toronto.

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How to build great cities, great universities at home and abroad

sgupta — Thu, 12 Jun 2014 11:30:57 +0000

How to build great cities, great universities at home and abroad sgupta Thu, 06/12/2014 - 07:30

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The Role of Universities in Building Sustainable Cities (photo by Terry Lavender)

Terry Lavender

Author legacy

Terry Lavender

Topic

Global Lens

International Relations

International

India

Engineering

Dalla Lana School of Public Health

Subheadline

Using expertise in infrastructure, public health, environment, innovation and entrepreneurship to make livable cities

Great universities need great cities, and great cities need great universities.

That’s the message that University of Toronto president Meric Gertler brought first to the U of T community during his inauguration speech and then to the broader Toronto community when he spoke to the Toronto Region Board of Trade last month.

And now he’s taking that message internationally. In October, Gertler will participate in a Brazil-Canada Cities Summit in Sao Paulo. And this past week he shared the message with Devang Khakhar, director of the Bombay Indian Institute of Technology (IIT Bombay) when Khakhar and his colleagues visited U of T for a round table on the University and the City: The Role of Universities in Building Sustainable Cities.

The round table brought together U of T academics from a variety of disciplines involved in urban studies, including public health, engineering, business and global affairs, to discuss their research in a 60-minute dialogue with the IIT Bombay delegation.

Gertler told Khakhar that U of T and IIT Bombay share a common interest in making cities as livable as possible. U of T, he said, needs to partner “with other great universities in other great cities around the world, learning from you about the ways that you are engaging with your local partners and applying those lessons to our own circumstances.”

In turn, Khakhar said that his institution’s Centre for Urban Science and Engineering welcomes collaboration with U of T. He noted that the new Indian government led by Narendra Modi has pledged to plan 100 new cities. IIT Bombay will be expected to play a major role in those plans, and collaboration with other urban experts around the world will be essential.

The U of T researchers at the round table – including Howard Hu, the dean of the Dalla Lana Faculty of Public Health, IMPACT Centre director Cynthia Goh, the Munk School of Global Affairs’ David Wolfe and Edward S. Rogers Sr. Department of Electrical & Computer Engineering Chair Farid Najm – all said they were eager to take Khakhar up on his invitation to collaborate.

For example, civil engineering professor Constantin Christopolous said it was important that India take into consideration how buildings are constructed when planning the new cities, citing the experience of Christchurch, New Zealand, which will have to demolish many of its buildings damaged in the 2011 earthquake. Asian Institute director Joseph Wong said he would like to discuss how IIT Bombay and U of T can collaborate on solving social inequality. Engineering professor and IC-IMPACTS associate director Stewart Aitchison noted that IC-IMPACTS (the India-Canada Centre for Innovative Multidisciplinary Partnerships to Accelerate Community Transformation and Sustainability) already has a successful record of research collaboration and would be happy to continue and expand those efforts.

Gertler said the variety of disciplines present at the table showed both U of T’s depth and breadth of expertise and the need for a multidiscipline approach to urban issues. Infrastructure, public health, environment, innovation and entrepreneurship are all needed in order to make livable cities.

“We need to embrace our role as a city builder more enthusiastically than we have perhaps done in the past. The better we make Toronto, the better we make the University of Toronto.”

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Bringing cheaper, lighter solar cells outdoors

sgupta — Mon, 09 Jun 2014 12:40:26 +0000

Bringing cheaper, lighter solar cells outdoors sgupta Mon, 06/09/2014 - 08:40

Cutline

Co-authors Zhijun Ning (left) and Oleksandr Voznyy (right) examine a film coated with colloidal quantum dots (photo by Roberta Baker)

Marit Mitchell

Author legacy

Marit Mitchell

Topic

Subheadline

“The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels”

Think those flat, glassy solar panels on your neighbour’s roof are the pinnacle of solar technology? Think again.

Researchers in the University of Toronto’s Edward S. Rogers Sr. Department of Electrical & Computer Engineering have designed and tested a new class of solar-sensitive nanoparticle that outshines the current state of the art employing this new class of technology.

This new form of solid, stable light-sensitive nanoparticles, called colloidal quantum dots, could lead to cheaper and more flexible solar cells, as well as better gas sensors, infrared lasers, infrared light emitting diodes and more. The work, led by post-doctoral researcher Zhijun Ning and Professor Ted Sargent, was published this week in Nature Materials.

Collecting sunlight using these tiny colloidal quantum dots depends on two types of semiconductors: n-type, which are rich in electrons; and p-type, which are poor in electrons. The problem? When exposed to the air, n-type materials bind to oxygen atoms, give up their electrons, and turn into p-type.

Ning and colleagues modelled and demonstrated a new colloidal quantum dot n-type material that does not bind to oxygen when exposed to air.

Maintaining stable n- and p-type layers simultaneously not only boosts the efficiency of light absorption, but also opens up a world of new optoelectronic devices that capitalize on the best properties of both light and electricity. For you and me, this means more sophisticated weather satellites, remote controllers, satellite communication or pollution detectors.

“This is a material innovation, that’s the first part, and with this new material we can build new device structures,” said Ning. “Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stability—no one has shown that before.”

Ning’s new hybrid n- and p-type material achieved solar power conversion efficiency up to eight per cent—among the best results reported to date.

But improved performance is just a start for this new quantum-dot-based solar cell architecture. The powerful little dots could be mixed into inks and painted or printed onto thin, flexible surfaces, such as roofing shingles, dramatically lowering the cost and accessibility of solar power for millions of people.

“The field of colloidal quantum dot photovoltaics requires continued improvement in absolute performance, or power conversion efficiency,” said Sargent. “The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels.”

This research was conducted in collaboration with Dalhousie University, King Abdullah University of Science and Technology and Huazhong University of Science and Technology.

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University of Toronto biologists pave the way for improved epilepsy treatments

sgupta — Mon, 09 Jun 2014 09:06:28 +0000

University of Toronto biologists pave the way for improved epilepsy treatments sgupta Mon, 06/09/2014 - 05:06

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(photo by Anthony Catalano via Flickr)

Sean Bettam

Author legacy

Sean Bettam

Topic

Faculty of Arts & Science

Research

Global

Subheadline

Discovery may lead to relief for victims of a range of neurological disorders

University of Toronto biologists leading an investigation into the cells that regulate proper brain function have identified and located the key players whose actions contribute to afflictions such as epilepsy and schizophrenia.

The discovery is a major step toward developing improved treatments for these and other neurological disorders.

“Neurons in the brain communicate with other neurons through synapses, communication that can either excite or inhibit other neurons,” said Professor Melanie Woodin in the Department of Cell and Systems Biology at U of T, lead investigator of a study published June 5 in Cell Reports.

“An imbalance among the levels of excitation and inhibition – a tip towards excitation, for example – causes improper brain function and can produce seizures. We identified a key complex of proteins that can regulate excitation-inhibition balance at the cellular level.”

This complex brings together three key proteins required for inhibitory and excitatory synaptic communication. The protein KCC2 is required for inhibitory impulses, while GluK2 is a receptor for the main excitatory transmitter glutamate, and Neto2 is an auxiliary protein that interacts with the other two proteins.

The discovery of the complex of three proteins is pathbreaking as it was previously believed that KCC2 and GluK2 were in separate compartments of the cell and acted independently of each other.

“Finding that they are all directly interacting and can co-regulate each other’s function reveals for the first time a system that can mediate excitation-inhibition balance among neurons themselves,” said Vivek Mahadevan, a PhD candidate in Woodin’s group and lead author of the study.

Mahadevan and fellow researchers made the discovery via biochemistry, fluorescence imaging and electrophysiology experiments on mice brains. The most fruitful technique was the application of an advanced sensitive gel system to determine native protein complexes in neurons, called Blue Native PAGE. The process provided the biochemical conditions necessary to preserve the protein complexes that normally exist in neurons. Blue Native PAGE is advantageous over standard gel electrophoresis, where proteins are separated from their normal protein complexes based on their molecular weights.

“The results reveal the proteins that can be targeted by drug manufacturers in order to reset imbalances that occur in neurological disorders such as epilepsy, autism spectrum disorder, schizophrenia and neuropathic pain,” said Woodin. “There is no cure for epilepsy; the best available treatments only control its effects, such as convulsions and seizures. We can now imagine preventing them from occurring in the first place.

“It was the cellular mechanisms that determine the excitation-inhibition balance that needed to be identified. Now that we know the key role played by KCC2 in moderating excitatory activity, further research can be done into its occasional dysfunction and how it can also be regulated by excitatory impulses,” said Mahadevan.

Other investigators involved in the research included scientists at the Hospital for Sick Children Research Institute, Vanderbilt University School of Medicine, Jewish General Hospital at McGill University, and the Institute of Biomedicine/ Anatomy at the University of Helsinki.

The findings are reported in the article “Kainate Receptors Coexist in a Functional Complex with KCC2 and Regulate Chloride Homeostasis in Hippocampal Neurons” published online June 5 in Cell Reports. The research was supported by funding from the Canadian Institutes of Health Research, the National Institutes of Health, and the Academy of Finland.

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Transforming education: getting kids hooked on science, technology, engineering and math

sgupta — Tue, 13 May 2014 12:20:39 +0000

Transforming education: getting kids hooked on science, technology, engineering and math sgupta Tue, 05/13/2014 - 08:20

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U of T Engineering hosted the annual gathering of physics teachers from across Ontario (photo by Ryan Mallough)

Marit Mitchell

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Marit Mitchell

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Professors share tips on innovative approaches to STEM

Always dreamed of being a doctor, lawyer or business leader? Try taking physics, math and engineering.

Students who score highest on the MCAT – the standardized exam for entry to medical school – are those who didn’t take pre-med, physiology or even biology, said Damian Pope of the Perimeter Institute of Theoretical Physics. Instead, they took physics, math and electrical engineering.

The same holds true for the LSAT, the law school entrance exam, and GMAT, for business school, he told the 2014 conference of the Ontario Association of Physics Teachers (OAPT), hosted by The Edward S. Rogers Sr. Department of Electrical & Computer Engineering.

A solid education in science, technology, engineering and math, called “STEM disciplines”, is the best background a student could bring to any 21st-century career, Pope told physics teachers from across Ontario who had gathered to discuss novel approaches to STEM education, from high school through university.

“STEM for university is the wrong message – it’s STEM for life, it’s STEM from elementary school,” said Bonnie Schmidt, president of the science advocacy group Let's Talk Science. “STEM is driving the jobs…and kids are not making the connection, and parents are not making the connection.”

In her keynote address, Schmidt pointed out that only 27 per cent of 16 to 18-year-olds believe science has relevance in their everyday lives, and only 11 per cent of Ontario students take Grade 12 physics. Meanwhile, more than 50 per cent of undergraduate students in China are studying science or engineering. “Kids’ perception that science takes place in a laboratory is an impression we have to change,” she said.

The three-day conference featured talks from the Perimeter Institute for Theoretical Physics, Sir Wilfred Laurier University, University of Ontario Institute of Technology, Queen’s University, University of Guelph, Trent University and Ryerson University, as well as workshop sessions led by physics teachers from dozens of high schools across the province.

Students were the focus of every discussion – how can teachers engender fascination in science and technology, improve retention and lead their students to fulfilling careers? “I would leave you with a challenge,” said Dave Fish, a teacher at Sir John A. MacDonald Secondary School in Waterloo, Ont. who also works on outreach with the Perimeter Institute. “How are you preparing students for the world? For careers, yes, but what about as global citizens?”

Professor Micah Stickel, director of outreach for ECE and First Year Chair for the Faculty of Applied Science & Engineering, led a session on his experience teaching with an inverted classroom approach. An inverted classroom has students introducing themselves to new material in video tutorials at home, then coming to class prepared for discussion and problem-solving activities.

“It’s really the learner who creates their own meaning, and if they don’t create it, it won’t be with them in six months,” said Professor Stickel.

Professor George Eleftheriades led a session about his electromagnetics work, and Professors Nazir Kherani, Olivier Trescases and Zeb Tate gave an overview of their work within the context of energy research in ECE. Professor Stewart Aitchison and Willy Wong closed out the day with a session on their activities in photonics and biomedical engineering.

“For me, the beautiful thing about this conference is that it’s an opportunity for me to engage with a group that I don’t normally get to talk with and that I really love to,” said Stickel.

“Our primary goal is to provide teachers with opportunities to network, to build a community of physics educators,” said Lisa Lim-Cole, vice-president of the OAPT and conference organizer. “We need to recharge that motivation of why we teach, and in this environment we can inspire each other.”

The OAPT organizing committee received enormous support from the Engineering Outreach Office. Next year’s event aims to expand the scope even further to consider best approaches to STEM education in Grades 7 and 8.

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