An AI tool developed by U of T Engineering professor Nicole Weckman (ISTEP, ChemE) can quickly diagnose infections caused by Candida auris (C. auris) — a pathogenic fungus that has risen to the top of global threat lists for hospital-acquired infections. The organism has been behind many deadly disease outbreaks in hospitals and has developed resistance to multiple common antifungal drugs, making it difficult to diagnose and treat.
The new diagnostic platform is called digital SHERLOCK (dSHERLOCK) and was introduced in a study published recently in Nature Biomedical Engineering. It was developed by Weckman and her collaborators while she was a postdoctoral fellow at Harvard University’s Wyss Institute.
The tool builds on an earlier technology known as Specific High-sensitivity Enzymatic Reporter unlocking (SHERLOCK), which was created by Professor James Collins, the Termeer Professor of Medical Engineering & Science at MIT and a founding member of the Wyss Institute. It uses CRISPR-Cas proteins to detect unique DNA sequences that can help identify which pathogen is causing an infection.
dSHERLOCK takes this system to the next level by bringing in the power of AI. Machine learning algorithms are used to measure and analyze the fluorescence produced by thousands of tiny CRISPR reactions at once, which allows quantitative measurements of how much of a pathogen is in a sample in less than 20 minutes.
The international research team — co-led by Collins and Professor David Walt of the Wyss Institute’s Diagnostics for Human and Planetary Health platform — was assembled in response to several outbreaks of C. auris infections in hospitals around the world.
These outbreaks highlight the need for enhanced diagnostic tools to help prevent the spread of infections in our healthcare systems. The appearance of treatment resistant C. auris strains also poses major health risks to immune-compromised individuals, such as patientsreceiving chemotherapy or nursing home residents.
“There are two challenges to dealing with C. auris outbreaks,” says Weckman.
“The first challenge is diagnosing that the infection is caused by C. auris and the second challenge is determining which antifungal treatment will be most effective.”
Currently, determining if C. auris is resistant to a particular antifungal treatment can take up to a week, whereas patients suffering from the infection require immediate treatment.
Weckman joined the team at the Wyss Institute in 2020 to help dive deeper into SHERLOCK’s CRISPR-mediated detection mechanism to speed up the diagnosis process.
“My postdoctoral work with Professor Collins was focused on developing streamlined, one-step CRISPR diagnostics that detected C. auris genes and single base mutations in C. auris DNA that are associated with resistance to antifungals,” says Weckman.
“We found that CRISPR reactions detecting DNA with a mutation generated fluorescence at a different rate than DNA without the mutation. We then used machine learning to analyze the fluorescence signals allowing us to quantify how much of a particular mutation was in the sample in only 40 minutes,” she says.
“The capabilities that we are introducing with dSHERLOCK satisfy the major clinical requirements for a next-generation assay to rapidly identify and quantify the C. auris burden in easily obtained patient samples,” says Collins, who is co-senior author of the study.
“This has not been possible using previous diagnostic methods and is a technological feat that, in addition to CRISPR engineering, required us to deeply integrate the SHERLOCK technology with the Walt group’s cutting-edge single molecule detection technology and a tailored machine learning approach.”
Since establishing her research group at the University of Toronto in January 2023, Weckman has carried on her research into detecting antimicrobial resistant Candida infections.
She received a New Connections Grant from the Emerging & Pandemic Infections Consortium to collaborate on this project with Dr. Robert Kozak, clinical microbiologist at Shared Hospital Laboratory located at Sunnybrook Health Sciences Centre and Professor in the Department of Laboratory Medicine & Pathobiology at the University of Toronto..
Weckman Lab member Amy Heathcote (ChemE MASc, 2T5) recently completed her MASc designing CRISPR diagnostics for three other Candida species that can cause severe invasive infections: Candida albicans, Candida parapsilosis and Candida glabrata.
Heathcote also investigated how to engineer CRISPR systems to reliably detect antimicrobial resistance mutations, even for particularly hard to detect DNA sequences of interest.
Researchers are optimistic about the potential future applications of dSHERLOCK against other infections and viruses.
“The dSHERLOCK platform has much broader utility beyond the C. auris threat: by allowing us to refit the specifics of the CRISPR-based detection machinery it can be relatively easily adopted to detect, quantify and characterize multiple other pathogens that pose serious health problems,” says Walt.
Weckman — who is also the Paul Cadario Chair in Global Engineering and a Core Research Faculty member with the Centre for Global Engineering (GGEN) at the University of Toronto —is encouraged by the ability to deploy this platform in international healthcare settings.
“Two of the major advantages of the CRISPR diagnostic platform are that it can be easily redesigned to detect many different infectious pathogens and it can be run at room temperature without the need for costly equipment,” says Weckman.
“Our group is looking at how we can use this technology, beyond C. auris diagnosis, to help tackle global challenges in healthcare, water quality, and agriculture,” says Weckman.
Engineering talent tends to run in families — and for the Ying family, the engineering spirit also lies at the heart of a gift that will long outlast themselves.
Yvonne Ying (EngSci 9T6), Irene Ying (ChemE 0T4) and Ivan Ying (ChemE 0T5) all graduated from U of T Engineering before going on to complete medical degrees: Irene and Ivan studied medicine at U of T, while Yvonne went to the University of Calgary. Their older sister Ethel Ying is also a physician, having graduated from U of T Medicine in 1997.
Recently, all four siblings came together to create two new annual student awards in honour of their parents: the Pamela & Wei Ming Ying Engineering Award and the Pamela & Wei Ming Ying MD Award. Both awards are based on financial need, and both will be matched by funding from the university itself.
“Our father has a PhD in engineering, and he was a professor of mechanical engineering in Singapore and Hong Kong,” says Yvonne.
“Honestly, I think he’s a little disappointed that we all became doctors instead of engineers,” says Ivan.
“But I do think having an engineering background helps a lot in the work we do. If you think of a project like the fourth-year plant design course we take in chemical engineering, it’s all about teamwork and problem solving. That’s good preparation for the day-to-day work of medicine, and many other fields as well.”
Irene says that while she was always interested in using mathematics and science, her decision to choose U of T Engineering was in no small part influenced by the experience of her older sibling.
“I liked the practical aspects of it, the chance to use my knowledge to take on big challenges,” she says.
“But I also remembered the parties that Yvonne used to have at our house while I was still in elementary school: dozens of her friends from U of T Engineering would come over, and they’d stay all night. I was impressed by the camaraderie, by how tight-knit this group of people was. I knew it was a community I wanted to be part of.”
“It’s true, so many of them have become lifelong friends,” says Yvonne.
“We’re still getting together for dinner, even though we graduated decades ago. It’s those foundational bonding experiences, like the plant design course that Ivan mentioned, that keep you connected.”
All three alumni say that one of the purposes of the new awards is to help ensure that future generations will get to have the same formative experiences they did.
In creating them, they are honouring not only their father’s legacy as a professor of mechanical engineering, but also their mother’s beliefs about the importance of giving back.
“Our parents have always emphasized the importance of education and of being grateful for the opportunities we’ve had,” says Yvonne.
“We are very lucky to be from Toronto and to have a great educational institution in our back yard. It’s been the foundation for the careers we’ve had since.”
It’s not the first time the Ying family has donated to U of T: their names are also featured on a bench in the Myhal Centre, a chair in Convocation Hall, and even on the paving stones outside Front Campus.
But these awards are particularly special, so much so that they kept them secret from their parents — revealing them only as a Christmas gift this past winter.
“At this point in their lives, they already have everything they need, and they’ve been clear that they don’t want more things,” says Irene.
“A gift like this is far more meaningful, because it will keep on giving in perpetuity.”
Join the Ying siblings in fostering the next generation of engineering leaders — explore more ways to support U of T Engineering.
A new strategy for estimating how much rainwater finds its way into sanitary sewer systems could help prevent problems such as backups and floods, while reducing treatment costs.
The tool is particularly useful in areas where accurate data about sewer flow rates is difficult to find, such as in low and middle-income countries, where many new sewer systems are being built.
“In theory, storm sewers and sanitary sewers should be separated, but in many older systems, they are combined,” says Gabrielle Migliato Marega (CivMin PhD 2T6), lead author on a new paper published in Water Science & Technology.
“Even if they are theoretically separate, there’s always crossover: it’s unrealistic to think that no stormwater is getting to the system. That extra stormwater can overwhelm the plants designed to treat the wastewater, so you get raw sewage flowing into lakes and rivers. You can also get problems like sewer backups and basement flooding.”
In the past, several different methods have been used to estimate how much storm water is getting into sanitary sewers.
“One common approach is based on flow rates: you basically take an average flow at times when it’s not raining heavily, another average at times when it is raining heavily, and then subtract the two,” says Marega.
When this level of detail is not available, the amount of storm water can be estimated by comparing the long-term average sewer flow to the amount of sewage a city of a given size is expected to generate.
“Another approach is to use some sort of tracer for the presence of sewage. For example, a common water metric is called biological oxygen demand (BOD), which is proportional to the amount of organic material in the wastewater,” says Marega.
“When that wastewater gets diluted with storm water, the BOD will go down, so you can measure that difference to estimate the storm water inflow and infiltration.”
Marega says that previous studies in the field have mostly focused on comparing which of the various methods provided the most accurate estimate of storm water inflow and infiltration into sanitary sewers.
“What’s different about our paper is that we decided to combine two different methods: the long-term average flow rate and BOD methods,” she says.
“If each one is appropriately weighted, we get a much better estimate than would be possible using either method alone.”
To test this out, Marega, who was co-supervised by Professor David Meyer (CivMin) and Professor Jennifer Drake at Carleton University, built a mathematical model that she used to simulate the function of a hypothetical city’s sewer system.
Using what’s known as a Monte Carlo approach, she simulated thousands of scenarios, each with a different storm water inflow and infiltration rate. She then compared how accurately each of the three methods — BOD, average flow rate, or the combined approach — estimated the simulated inflow and infiltration rate.
“We found that our combined method improved accuracy by more than 10%,” says Marega.
Armed with the new strategy, Marega then analyzed data from 46 different cities in her home country of Brazil. In each of these cases, the true rate of storm water inflow and infiltration was not known, and in some, the available data was patchy: flow rates might only be measured on average every three months, rather than every hour as they would be under ideal conditions.
But despite the data-poor environment, there was enough data to estimate storm water inflow using two different methods. Marega’s new approach combined both these methods, creating more plausible estimates of storm water infiltration that could be used to benchmark potential improvements to the system.
“For example, one of the most common causes of storm water inflow and infiltration is from households that connect the drain spouts from their roofs directly into sanitation sewers,” says Marega.
“If you find out that’s happening, you can update the building codes to prevent it or increase inspections to improve compliance. And if you’re building a new system, you can size it larger to ensure it’s going to be better prepared to deal with the larger flows that come with rainstorms.”
Meyer says that the team’s hope is for urban designers around the world to adopt the new method in their planning and maintenance processes.
“The key insight here is that by combining methods, we’re shifting the target,” he says.
“The goal is no longer to answer: what’s the best method? Instead, we’re asking: how can we use existing methods, plural, to learn the most about the system? That should enable us to design better sewers, improve wastewater treatment, and prevent the backups and floods that cause so much damage.”
Since September 2025, graduate students from across U of T Engineering and beyond have been engaging with the potential of atomic energy in a whole new way.
The new MEng emphasis in Nuclear Engineering prepares graduates to meet the growing demand for highly trained professionals in this area, which is playing an expanded role in energy, human health and sustainability.
“There really is something of a nuclear renaissance happening, not only in Canada, which has a long and proud history in this area, but around the world,” says Professor Nazir Kherani (MSE, ECE), who helped lead the creation of the new emphasis.
“For decades, nuclear has provided abundant low-carbon electricity, which is now more important than ever, and has been used to enhance human health through radioisotopes and nuclear medicine. But today, there is a lot of excitement about new potential approaches, including small modular reactors, nuclear fusion and even the possibility of nuclear-powered hydrogen production.”
The Master of Engineering (MEng) program is a course-based, professional master’s program that can be completed in one year of full-time study. The new nuclear emphasis is one of more than a dozen different specializations that MEng students can choose to pursue; other emphases range from Data Analytics and Machine Learning to Semiconductor Fabrication and Inspection.
At present, the MEng emphasis in Nuclear Engineering is open to students from the Department of Materials Science & Engineering (MSE) and the Department of Civil & Mineral Engineering (CivMin). However, opportunities to study nuclear engineering will continue to grow across the faculty given demand within the field.
New programming builds on existing U of T Engineering offerings in the area of nuclear technology, such as the nuclear engineering certificate which can be taken by undergraduate students, as well as various graduate-level courses in nuclear studies which are available to students from across the Faculty.
Central to the new emphasis are two newly created graduate-level courses, MSE 1074: Atomic Energy Materials Systems & Sustainability – Fundamentals I and MSE 1075: Fundamentals of Atomic Energy Materials Systems and Sustainability II.
Not only do these courses count toward the new MEng emphasis, they are also available as micro-credentials to students in disciplines and even other U of T faculties. More than a dozen MEng students from across U of T Engineering and several from other U of T faculties and departments have successfully completed the first (Fall term) course, and over twenty have already enrolled for the second (Winter term) course.
Sherry Esfahani (MSE MASc 1T0, PhD 1T6) External Relations Liaison & Communications Officer in the Department of Materials Science & Engineering, played a key role in developing the new courses.
“After I finished my PhD here at U of T Engineering, I spent a few years working in the nuclear field,” she says.
“I met a lot of new hires and interns, but not as many of them were from my alma mater as I would have expected. I wanted to make sure that our students have a pathway into this rapidly growing industry.”
Students taking the emphasis will receive a solid foundation in the fundamentals of atomic-nuclear physics, nuclear materials, nuclear reactor physics and radiation. They’ll also learn about radiation detection and safety, regulatory codes, nuclear thermal hydraulics, nuclear operations and AI, as well as nuclear medicine and next-generation reactors.
“Depending on their previous background, this emphasis could prepare students for all kinds of different careers,” says Kherani.
“Some might develop next-generation detector systems to monitor incipient failure mechanisms or advanced probes for non-destructive testing. Others might focus on maintenance or refurbishments of older plants, which has been carried out very successfully here in Canada.”
“And still others might be the ones to develop technologies that are not yet widely deployed, such as small modular reactors, or using AI to harvest useful information from the enormous amount of data that is generated by nuclear plants. They may be involved in researching fusion plasma physics, magnetic confinement and advanced superconductors. There are many interesting possibilities here.”
Esfahani agrees.
“The new emphasis opens strong career trajectories across the industry, healthcare and policy sectors,” she says.
“It will equip students with the skills needed to contribute to today’s nuclear energy generation, as well as the research, innovation and regulatory and safety leadership we will need for the future.”
Ayan Ahmed (Year 1 IndE) and Devan Morrison (Year 1 MechE) are more than halfway through their first year of engineering studies at U of T — but their paths to get here started in very different places.
Morrison says that his desire to pursue engineering developed at an early age.
“I’ve always had a fascination with engines — taking them apart, fixing and selling them. Around 10 years old, I was like, yeah, I should become a mechanical engineer,” he says.
But Ahmed says that engineering was not on her radar until much later.
“As a kid, I wanted to be a veterinarian, then thought I’d study law,” she says.
“It wasn’t until I was volunteering at a long-term care facility for older adults and people with disabilities that I realized the difference engineering innovations could make.”
What Ahmed and Morrison have in common is that in high school, they enrolled in the Blueprint summer program, an experience that both say profoundly changed how they looked at the engineering profession, as well as the University of Toronto itself.
“Before Blueprint, I didn’t want to apply to U of T,” says Ahmed.
“The program transformed my perspective not just of U of T engineering but also of myself. What once felt like an intimidating, prestigious place became a school where I realized I could thrive.”
Launched in 2020, Blueprint is an academic enrichment program designed for Black students interested in science and engineering. The program is open to Canadian students in Grades 10 and 11 who are interested in careers in STEM.
Blueprint consists of four weeks of summer programming featuring engineering-focused summer courses, fun and educational excursions, and community-building events. The summer component is followed by one or two year-long engagement streams involving regular meetups and monthly webinars.
“It was unlike any other STEM summer camp or program I’ve been to,” says Morrison.
“We got to look at topics in depth, and it was the closest thing I’d had at that point to an actual university engineering experience.”
In the summer program, Monday to Thursday is taken up with courses on topics such as engineering and human health, or mechatronics and automation. On Fridays, participants take STEM-focused field trips to places such as the University of Toronto Institute for Aerospace Studies (UTIAS), the Toronto Islands or Canada’s Wonderland.
“When we went to the aerospace facility, we got to walk around and see all the PhD students — what they were making and studying,” says Morrison.
“For me, it solidified the idea that I wanted to be an engineer and do this kind of stuff.”
Part of the program also involves weekly lectures from U of T professors from different departments and areas of research. Ahmed says she was inspired to pursue industrial engineering in part after hearing a talk from Professor Myrtede Alfred (MIE).
“She blew me away,” says Ahmed.
“One of my main goals in life is to create a more accessible world and I learned industrial engineering and human-centred design is all about that.”
In addition to its learning opportunities, both Morrison and Ahmed say that one of the most valuable aspects of Blueprint was how it offered them the chance to connect with other Black students interested in STEM.
“I grew up in a predominantly white neighbourhood where I didn’t have a lot of Black classmates to talk to about academia, so going to Blueprint was really cool because there was a group of like-minded people who all kind of looked like me,” says Morrison.
Following completion of the program, Morrison was awarded a McAllister Foundation scholarship, while Ahmed was the recipient of the U of T Engineering Entrance Scholarship for Black Students, which she says she never would have known about if not for Blueprint.
“Blueprint has a program called My Academic Preparation Sessions, or MAPS, that helps you prepare to apply to U of T Engineering and that’s when I learned about the entrance scholarship,” says Ahmed.
“I’d already applied to so many scholarships and was turned down, so when I saw I got it, I was so excited.”
Now well into their first year of engineering study, Ahmed and Morrison are making the most of their time and planning for what’s next.
“I love the professors. They’re all really invested in their students succeeding. And they’re just so open and inviting,” says Ahmed.
“My friend and I are trying to start a coffee brewing business and having professors with industry experience has been so helpful,” says Morrison.
“It’s really nice to talk to people in the profession who know what they’re doing and can answer your questions. I’ve had questions my whole life that no one has been able to answer. And now there are finally people here to answer them.”
Applications for the 2026 Blueprint summer program are open until March 29.
Taller buildings get a bad rap. New research from U of T Engineering’s Centre for the Sustainable Built Environment (CSBE) has found that while adding height does slightly increase embodied emissions, other building and neighbourhood design factors are far more important.
The paper, recently published in Resources, Conservation and Recycling, looked at how building height affects embodied emissions for new five- to 20-storey reinforced concrete residential buildings.
“There’s a fairly loud narrative that taller buildings are bad buildings, but from a resource use perspective and an embodied carbon perspective, mathematically something seemed off,” says Professor Shoshanna Saxe (CivMin), director of the CSBE.
“Let’s say you need a certain amount of housing. If you planned to build a 20-storey building but instead you build a 10-storey one, you’re going to need to put those 10 extra floors somewhere else. That means more roads, more utilities, more elevators. Another building quickly swamps out the small increased emissions from height.”
Avery Hoffer (CivE 2T2 + PEY, MASc 2T5), lead author on the paper, says that right now, figuring out how to build more while using fewer materials is paramount.
“We’re currently facing two crises, not just in Toronto, but more broadly as a country,” says Hoffer.
“We have the housing crisis in Canada where we need 3.5 million additional units by 2030, and we also have the climate crisis where buildings account for 11% of our total embodied greenhouse gas emissions. We’re also not on track to limit global warming to 1.5°C above pre-industrial levels.”
For their study, researchers modeled 128 concrete apartment buildings, changing various key design features such as height and slab thickness. For each building version, they calculated the materials needed and the embodied emissions for the building.
When the study was complete, researchers found several design decisions have a much stronger impact on carbon emissions than height, with concrete slab size being the worst offender.
“Just the floor slabs alone can account for up to 75% of the total embodied emissions of the structure,” says Hoffer.
“What we see in Canada is that a lot of these buildings are built with slabs in the 200–225-millimetre thickness range, which is more than what we’ve found is needed. So just by changing a small amount of your floor slab, you can save very large amounts of emissions.”
While the amount of concrete is a major driver of emissions in taller buildings, the researchers found that other common design decisions can also significantly increase a structure’s carbon footprint.
“Often for ease of design and constructability, most of the floors in a building are designed to be the same,” says Professor Evan Bentz (CivMin), a CSBE investigator and co-author on the paper.
“A 15-storey building might just have two floor designs, where the top floor ends up being much stronger than it needs to be because it’s easier to just keep building the same way up.”
Saxe says that both city bylaws and norms in the industry are contributing to more polluting, expensive and resource intensive buildings.
“In Toronto, for example, there are requirements for things like step backs that require thick concrete transfer slabs, or garbage truck turn around space, which messes with floor plates.”
“There’s also an issue of construction and design culture and what we’re willing to pay for. We pay a lot to pour concrete. We don’t pay very much for top notch design.”
There is a limit to the building heights modelled in the study. Other research that has tested buildings above 20 storeys suggests the height premium does gets more pronounced at around 50 storeys and above.
“We’re not saying we should build 120-storey buildings everywhere, but we should certainly be allowing five- to 20-storeys in a lot more places and making it much easier for those heights to be built,” says Saxe.
“We need housing and we need to build it in a sustainable way. Every time we lop a unit out of a building and put it somewhere else, that second building is more polluting than having it all in one structure.”