Breaking Research

department of mechanical and industrial engineering

Artificial Intelligence

Cities

Sustainability

Subheadline

“If you optimize for equity, you get a map that is more spread out and less concentrated in the downtown areas"

A team of researchers from the department of civil and mineral engineering in the University of Toronto’s Faculty of Applied Science & Engineering are wielding machine learning to understand where cycling infrastructure should be located in order to benefit the most people.

In a paper published in the Journal of Transport Geography, researchers used novel computing approaches to compare two strategies for expansion of protected bike lanes – using Toronto as a model.

“Right now, some people have really good access to protected biking infrastructure: they can bike to work, to the grocery store or to entertainment venues,” says post-doctoral fellow and lead author Madeleine Bonsma-Fisher, who previously researched interactions between bacteria and viruses before applying her data analysis skills to active transportation. “More lanes could increase the number of destinations they can reach, and previous work shows that will increase the number of cycle trips taken.

“However, many people have little or no access to protected cycling infrastructure at all, limiting their ability to get around. This raises a question: is it better to maximize the number of connected destinations and potential trips overall, or is it more important to focus on maximizing the number of people who can benefit from access to the network?”

To delve into the question, Bonsma-Fisher and co-authors used machine learning and optimization, a challenge that required them to explore new computational approaches.

“This kind of optimization problem is what’s called an ‘NP-hard’ problem, which means that the computing power needed to solve it scales very quickly along with the size of the network,” says Shoshanna Saxe¸ associate professor in the department of civil and mineral engineering and one of Bonsma-Fisher’s two co-supervisors alongside Professor Timothy Chan of the department of mechanical and industrial engineering. “If you used a traditional optimization algorithm on a city the size of Toronto, everything would just crash.”

To get around the problem, PhD student Bo Lin invented a machine learning model capable of considering millions of combinations of over a thousand different infrastructure projects in order to test where the most impactful places are to build new cycling infrastructure.

Using Toronto as a stand-in for any large, automobile-oriented North American city, the team generated maps of future bike lane networks along major streets, optimized according to two broad types of strategies.

The first strategy, dubbed the utilitarian approach, focused on maximizing the number of trips that could be taken using only routes with protected bike lanes in under 30 minutes – without regard for who those trips were taken by.

The second, an equity-based strategy, sought to maximize the number of people who had at least some connection to the network.

“If you optimize for equity, you get a map that is more spread out and less concentrated in the downtown areas,” says Bonsma-Fisher. “You do get more parts of the city that have a minimum of accessibility by bike, but you also get a somewhat smaller overall gain in average accessibility.”

This results in a trade-off, says Saxe. “This trade-off is temporary, assuming we will eventually have a full cycling network across the city, but it is meaningful for how we do things in the meantime and could last a long time given ongoing challenges to building cycling infrastructure.”

Another key finding was that certain routes appeared to be essential no matter what strategy was pursued – for example, protected bike lanes along Bloor Street West.

“Those bike lanes benefit even people who don’t live near them and are a critical trunk to maximizing both the equity and utility of the bike network. Their impact is so consistent across models that it challenges the idea that bike lanes are a local issue, affecting only the people close by,” Saxe says. “Optimized infrastructure repeatedly turns out in our model to serve neighbourhoods quite a distance away.”

The team is already sharing their data with Toronto’s city planners to help inform ongoing decisions about infrastructure investments. Going forward, the researchers hope to apply their analysis to other cities as well.

“No matter what your local issues or what choices you end up making, it’s really important to have a clear understanding of what goals you are aiming for and check if you are meeting them,” says Bonsma-Fisher.

“This kind of analysis can provide an evidence-based, data-driven approach to answering these tough questions.”

Researchers uncover new role for cell’s waste disposal system in spread of pancreatic cancer

Christopher.Sorensen — Tue, 22 Oct 2024 14:02:57 +0000

Researchers uncover new role for cell’s waste disposal system in spread of pancreatic cancer

Christopher.Sorensen Tue, 10/22/2024 - 10:02

Cutline

Associate Professor Leonardo Salmena, post-doctoral researcher Golam Saffi and former master’s student Lydio To investigated the role of a gene called INPP4B in pancreatic cancer’s ability to spread (supplied images)

Betty Zou

Topic

Princess Margaret Cancer Centre

Cancer

University Health Network

A preclinical study is revealing new insights into the molecular machinery that drives the aggressiveness of pancreatic cancer.

The ability of pancreatic cancer to invade and spread to other parts of the body is a major factor in its poor prognosis, with an overall five-year survival rate of less than 10 per cent.

“Pancreatic cancer cells are known to be very metastatic and that’s a big problem,” says Leonardo Salmena, an associate professor of pharmacology and toxicology in the University of Toronto’s Temerty Faculty of Medicine.

Salmena is the senior author of a study, published in the Journal of Cell Biology, that investigates the role of a gene called INPP4B in pancreatic cancer’s ability to spread. Led by post-doctoral researcher Golam Saffi and former master’s student Lydia To, the team found that INPP4B exerts its tumour-promoting effects via a cellular organ called the lysosome.

“Classically, the lysosome is a garbage disposal organelle where old and tired proteins and other organelles get degraded to be used for energy and other building blocks for the cell,” says Salmena.

In most cells, lysosomes typically cluster around the nucleus. But in pancreatic cancer cells, the researchers found that INPP4B drove the lysosomes from the cell interior to the periphery, where these organelles fuse with the cell’s outer membrane. In doing so, the enzymes and other lysosomal factors responsible for breaking down cellular waste are dumped into the space surrounding the tumour cells.

This space contains a network of proteins and molecules that provides crucial structural support to cells and tissues while also restricting a cell’s ability to move. The release of the lysosome’s protein-degrading contents into this extracellular space causes the stabilizing network to fall apart, thus making it easier for pancreatic cancer cells to migrate and invade other tissues.

Crucially, Salmena and his team also identified the signalling pathway by which INPP4B drives the movement of lysosomes to the cell edge. INPP4B works with two other proteins – PIKfyve and TRPML-1 – to modify the lysosome’s surface structure and alter local calcium levels so that the organelle is propelled to the cell periphery.

Based on these findings, the researchers are testing two experimental drugs that target TRPML-1 and PIKfyve in a preclinical model of pancreatic cancer. They are also studying how the release of lysosomal contents can change the immunological environment of the cancer cells, and what effects that might have on the immune system’s ability to respond to the tumour.

Salmena first became interested in INPP4B when, during his post-doctoral research, he found that it was involved in breast cancer. Since then, he and his team have shown that the effects of INPP4B vary depending on the context.

For example, in some breast cancer types, INPP4B behaves as a tumour suppressor whereas it has an activating role in other aggressive cancers like pancreatic cancer – which the Canadian Cancer Society expects to be the third leading cause of cancer death in Canada in 2024, with an estimated 6,100 people dying from the disease.

Salmena and his colleagues later showed that among all cancers, INPP4B levels are highest in pancreatic tumours, and that high levels of the protein are associated with decreased overall survival in people with pancreatic cancer.

The study was a collaboration between Salmena’s group, Roberto Botelho, a professor of chemistry and biology at Toronto Metropolitan University, and Steven Gallinger, a hepatobiliary and pancreatic surgical oncologist and clinician-scientist at Princess Margaret Cancer Centre, University Health Network and a professor of surgery and laboratory medicine and pathobiology in Temerty Medicine. He is also director of the PanCuRx Translational Research Initiative at the Ontario Institute for Cancer Research.

The study was supported by the Cancer Research Society and the Canadian Institutes of Health Research.

Large-scale adoption of electric vehicles can lead to human health benefits: Study

Christopher.Sorensen — Mon, 21 Oct 2024 14:05:14 +0000

Large-scale adoption of electric vehicles can lead to human health benefits: Study

Christopher.Sorensen Mon, 10/21/2024 - 10:05

Cutline

Researchers from �鶹��Ƶ's Faculty of Applied Science & Engineering used computer models to simulate the impact of large-scale adoption of electric vehicles in the U.S. (photo by: Plexi Images/Glasshouse Images/UCG/Universal Images Group via Getty Images)

Tyler Irving

Topic

Sustainability

Subheadline

"Our simulation shows that the cumulative public health benefits of large-scale EV adoption between now and 2050 could run into the hundreds of billions of dollars"

Large-scale adoption of electric vehicles (EVs) could lead to significant health benefits for populations, according to a new study from the department of civil and mineral engineering in the University of Toronto’s Faculty of Applied Science & Engineering.

Researchers used computer simulations to show that aggressive electrification of the U.S. vehicle fleet, coupled with an ambitious roll-out of renewable electricity generation, could result in health benefits worth between US$84 billion and 188 billion by 2050.

Even scenarios with less aggressive grid decarbonization mostly predicted health benefits running into the tens of billions of dollars.

“When researchers examine the impacts of EVs, they typically focus on climate change in the form of mitigating CO2 emissions,” says Professor Marianne Hatzopoulou, one of the co-authors of the study, which was published in PNAS.

“But CO2 is not the only thing that comes out of the tailpipe of an internal combustion vehicle. They produce many air pollutants that have a significant, quantifiable impact on public health. Furthermore, evidence shows that those impacts are disproportionately felt by populations that are low-income, racialized or marginalized.”

The research team previously used their expertise in life-cycle assessment to build computer models that simulated the impact of large-scale EV adoption in the U.S. market.

Among other things, they showed that while EV adoption will have a positive impact on climate change, it is not sufficient on its own to meet the Paris Agreement targets. They recommended that EV adoption be used in combination with other strategies, such as investments in public transit, active transportation and higher housing density.

In their latest study, the team sought to account for the non-climate benefits of EV adoption. They adapted their models to simulate the production of air pollutants that are common in fossil fuel combustion, such as nitrogen oxides, sulphur oxides and small particles known as PM2.5.

“Modelling these pollutants is very different from modelling CO2, which lasts for decades and ends up well-mixed throughout the atmosphere,” says study co-author Daniel Posen, an associate professor in the department of civil and mineral engineering.

“In contrast, these pollutants, and their associated health impacts, are more localized. It matters not only how much we are emitting, but also where we emit them.”

While EVs do not produce tailpipe emissions, they can still be responsible for air pollution if the power plants that supply them run on fossil fuels. This also has the effect of displacing air pollution from busy highways to the communities that live near those power plants.

Another complication is that neither the air pollution from the power grid nor that from internal combustion vehicles is expected to stay constant over time.

“Today’s gasoline-powered cars produce a lot less pollution than those that were built 20 years ago, many of which are still on the road,” says Jean Schmitt, post-doctoral fellow and lead author of the study.

“So, if we want to fairly compare EVs to internal combustion vehicles, we have to account for the fact that air pollution will still go down as these older vehicles get replaced. We can also see that the power grid is getting greener over time, as more renewable generation gets installed.”

The team, which also included Professor Heather MacLean of the department of civil and mineral engineering and Amir F. N. Abdul-Manan of Saudi Aramco’s Strategic Transport Analysis Team, chose two primary scenarios to simulate to the year 2050. In the first, they assumed that no more EVs will be built, but that older internal combustion vehicles will continue to be replaced with newer, more efficient ones.

In the second scenario, they assumed that by 2035, all new vehicles sold will be electric. The researchers described this as “aggressive,” but it is in line with the stated intentions of many countries. For example, Norway plans to eliminate sales of non-electric vehicles next year, and Canada plans to follow suit by 2035.

For each of these scenarios, they also considered various rates for the transition of the electric grid to low-emitting and renewable energy sources.

Under each set of conditions, the team simulated air pollution levels across the U.S. and used calculations commonly used by epidemiologists, actuaries and policy analysts to correlate pollution levels with statistical estimates of the number of years of life lost, as well as with estimates of economic value.

“Our simulation shows that the cumulative public health benefits of large-scale EV adoption between now and 2050 could run into the hundreds of billions of dollars,” says Posen.

“That’s significant, but another thing we found is that we only get these benefits if the grid continues to get greener. We are already transitioning away from fossil fuel power generation, and it’s likely to continue in the future. But for the sake of argument, we modelled what would happen if we artificially freeze the grid in its current state.

“In that case, we’d actually be better off simply replacing our old internal combustion vehicles with new ones – but again, this is not a very realistic scenario.”

This finding raises the question of whether it’s more important to decarbonize the transportation sector through EV adoption, or to first decarbonize the power generation sector that’s the ultimate source of pollution associated with EVs.

To that, Hatzopoulou notes that vehicles sold today will continue to be used for decades. “If we buy more internal combustion vehicles now, however efficient they may be, we will be locking ourselves into those tailpipe emissions for years to come, and they will spread that pollution everywhere there are roads,” she says. “We still need to decarbonize the power generation system – and we are – but we should not wait until that process is complete to get more EVs on the road.

“We need to start on the path to a healthier future today.”

Growing up with a dog may be good for your gut health: Study

rahul.kalvapalle — Thu, 26 Sep 2024 14:44:39 +0000

Growing up with a dog may be good for your gut health: Study

rahul.kalvapalle Thu, 09/26/2024 - 10:44

Cutline

Living with a dog between ages five and 15 is associated with reduced risk of developing Crohn’s disease, according to new research from Sinai Health and �鶹��Ƶ (photo by Kseniya Starkova/Getty Images)

Jovana Drinjakovic

Topic

Department of Immunology

Department of Medicine

Sinai Health

Lunenfeld-Tanenbaum Research Institute

Mount Sinai Hospital

Subheadline

Research from Sinai Health and �鶹��Ƶ found early exposure to dogs is linked to a healthier gut and reduced risk of developing Crohn's disease

Dog lovers can attest to the range of benefits that come with having a canine companion, but improved gut health likely isn’t one of them.

That may be about to change following research from Sinai Health and the University of Toronto that shows exposure to dogs during childhood is linked to beneficial changes in gut bacteria, gut permeability and blood biomarkers.

The study, published in Clinical Gastroenterology and Hepatology, found living with a dog between ages five and 15 is associated with a healthier gut microbiome and reduced risk of developing Crohn’s disease.

The research shines new light on how environmental factors influence the onset of Crohn’s – an inflammatory bowel condition – and could inform future prevention strategies.

For the study, researchers led by Kenneth Croitoru and Williams Turpin of Mount Sinai Hospital’s Centre for Inflammatory Bowel Disease (IBD) investigated how dozens of environmental factors impact the likelihood of developing Crohn’s as part of their overarching effort to be able to predict those at risk and potentially intervene early.

“The idea behind predicting someone's risk of disease is that you can then also begin to understand who you might want to do something to try and prevent disease,” says Croitoru, a clinician-scientist at the Lunenfeld-Tanenbaum Research Institute (LTRI), part of Sinai Health, and a professor of medicine and immunology at �鶹��Ƶ’s Temerty Faculty of Medicine.

Croitoru notes the study doesn’t reveal why living with a dog makes someone less prone to Crohn’s disease. “We have established associations between environmental factors and Crohn’s and are now trying to understand how these environmental factors affect the triggering of the disease,” says Croitoru, who is also a gastroenterologist at Mount Sinai Hospital.

The study also found living with a large-sized family in the first year of life to reduce the likelihood of getting Crohn’s. It also found people who lived with a bird at the time of study were more likely to develop the disease.

Caused by inflammation in the gastrointestinal tract, Crohn’s disease can have far-reaching consequences on overall health and well-being. Its incidence among children under 10 has doubled since 1995, while the annual cost of inflammatory bowel disease to Canada is estimated at $5.4 billion per year, according to Crohn’s and Colitis Canada, a national non-profit.

The likelihood of getting Crohn’s is strongly influenced by genetics, but the environment also plays a role, says Croitoru, who holds the Canada Research Chair in Inflammatory Bowel Diseases. While we can’t change our genes, we can modify our surroundings and diet, for example, to potentially prevent the disease from occurring.

These findings come from the Genetic, Environmental and Microbial (GEM) Project, the largest study of its kind that seeks to identify potential triggers of Crohn’s disease.

Coordinated at Mount Sinai Hospital since 2008, the GEM Project has been collecting comprehensive medical and lifestyle data from over 5,000 healthy first-degree relatives of people who have Crohn’s and come from all over the world, including Australia, Canada, Israel, New Zealand, the U.K. and the U.S.

The project is funded by Crohn’s and Colitis Canada, the Canadian Institutes of Health Research and the Helmsley Charitable Foundation.

In the 15 years since the study began, over 120 people have developed the disease. “By understanding what is different about those who develop the disease, we should be able to predict who is at risk,” says Croitoru.

Previously, the group identified differences in the microbiome and other biomarkers in people who go on to develop Crohn’s and those who don’t.

In another recent report published in Gastroenterology, Sun-Ho Lee, a clinician-scientist at Mount Sinai Hospital’s IBD Centre and an assistant professor at the Institute of Medical Science at Temerty Medicine, used available data and machine learning to develop an “integrative risk score” that predicts the risk of Crohn’s with a high degree of accuracy.

But risk prediction is only the first step, says Croitoru, whose ultimate goal is to be able to intervene and prevent the disease from starting.

He and his team are now conducting research that seeks to devise and test strategies for prevention by, for example, adding supplements to the diet to promote a healthy microbiome.

“Sinai Health is committed to groundbreaking research and bringing those discoveries to patients," said Anne-Claude Gingras, director of LTRI and vice-president of research at Sinai Health.

“By integrating genetic, environmental, and microbial data, Dr. Croitoru and colleagues are paving the way towards personalized intervention strategies that could significantly reduce the incidence of Crohn’s disease.”

Battery-powered EV chargers – co-developed at �鶹��Ƶ – installed on St. George campus

rahul.kalvapalle — Fri, 20 Sep 2024 14:34:25 +0000

Battery-powered EV chargers – co-developed at �鶹��Ƶ – installed on St. George campus

rahul.kalvapalle Fri, 09/20/2024 - 10:34

Cutline

The Level 3+ battery-powered EV charging stations are available in �鶹��Ƶ's Landmark Garage, located beneath King's College Circle on the St. George campus (photo by Safa Jinje)

Safa Jinje

Topic

department of mechanical and industrial engineering

Facilities and Services

Landmark

Sustainability

Subheadline

The rapid-charging stations were developed by Canadian EV tech company Jule in collaboration with experts at the Faculty of Applied Science & Engineering

The historic core of the University of Toronto’s St. George campus is now home to a pair of next-generation electric vehicle (EV) charging stations that utilize technology co-developed at the university.

The two new stations use direct current (DC)-sourced EV chargers boasting integrated battery energy storage systems – novel technology that minimizes strain on the electrical grid.

Located in the Landmark Garage beneath King’s College Circle, the chargers are rated Level 3+, meaning they can charge EVs in under 30 minutes, and bring the total number of EV charging stations in the garage to 50.

The technology underpinning the new charges was developed by Jule, an energy storage and EV solutions company co-founded by Faculty of Applied Science & Engineering alumnus Carmine Pizzurro, in collaboration with �鶹��Ƶ faculty members.

Jule embarked on its first research collaboration with �鶹��Ƶ shortly after its founding in 2009, teaming up with the Centre for Applied Power Electronics led by Professor Reza Iravani at the Edward S. Rogers Sr. department of electrical and computer engineering.

It also worked closely with the city's electric utility.

“One of our first collaborations was with Toronto Hydro, which led to us being the first company in the world to put lithium-ion batteries on the distribution grid to provide backup power during outages and reduce stress on the grid during peak periods,” says Pizzurro, who earned his bachelor’s and master’s degrees in mechanical engineering at �鶹��Ƶ.

Cristina Amon and Carlos Da Silva (fourth and fifth from left, respectively, in the front row) pose with students and staff in the Thermal Management Systems lab (photo by Aaron Demeter)

Pizzurro went on to install Jule’s first battery-powered fast chargers in northern Canada as part of a collaboration with Natural Resources Canada.

But the company needed to address a longstanding challenge with lithium-ion batteries: they’re temperature-sensitive and must be able to operate reliably in both hot and cold environments if they are to help power a net-zero future.

To tackle this issue, Jule in 2018 expanded its partnership with the Faculty of Applied Science & Engineering to include University Professor Cristina Amon and senior research associate Carlos Da Silva of the Advanced Thermofluids Optimization, Modelling and Simulation (ATOMS) laboratory in the department of mechanical and industrial engineering.

The ATOMS experts have been developing computational models and experimental characterization to optimize Jule’s battery thermal management systems – work that is being carried out in a state-of-the-art battery testing facility that received funding from the Canada Foundation for Innovation and Ontario Research Fund.

“Thermal management is an issue that impacts both aspects of Jule’s EV fast charging technology: the power electronics to enable the charging, as well as their unique integrated battery storage system,” says Da Silva, who is also executive director of the �鶹��Ƶ Electrification Hub. “Thermal management is critical for mitigating battery degradation. It requires regulating the temperature in such a way that you keep the battery within an optimal range that will extend its life span.”

Jule’s fast chargers use energy stored in batteries, rather than drawing it directly from the electrical grid in the manner of traditional fast chargers. That means they don’t cause grid overloading during peak usage times and can be charged during off-peak hours when electricity is less costly; they also don’t require significant investments in electricity upgrades.

“The battery storage system is charged using current from the electrical grid, which is alternating current (AC); and then this larger battery, which uses direct current (DC), charges the smaller battery in the electric vehicle,” says Amon. “It is more efficient to fast-charge from a stationary battery to an EV – DC to DC – than it is to fast-charge an EV from the electrical grid, which requires converting AC to DC power.”

Jule’s Level 3+ charging station can provide up to 200 kilowatts of power output, yet only needs 45 kilowatts of input power. Amon says this rapid charging speed can help alleviate range anxiety among EV users: “Some drivers fear that EV batteries may not have enough energy to reach a desired destination. But if charging time is much closer to the time required to fill up a tank of a gas-powered car, that can reduce this worry.”

L-R: Professor Reza Iravani, Jule co-founder Carmine Pizzurro, �鶹��Ƶ Electrification Hub Executive Director Carlos Da Silva, University Professor Cristina Amon and �鶹��Ƶ Engineering Dean Christopher Yip (photo by Safa Jinje)

The Level 3+ stations are joining 48 Level 2 chargers that are already available for public use at the Landmark Garage.

This increases the campus’s charging capacity to over 25,000 charges per year, which can eliminate over 700 tons of greenhouse gas emissions, according to �鶹��Ƶ’s Sustainability Office.

“Hosting these first-of-their-kind EV chargers right here on campus extends beyond providing a new and exciting sustainability service to our community,” says Ron Saporta, �鶹��Ƶ’s chief operating officer, property services and sustainability. “It represents just one example of how we are supporting the intersection of research, learning and commercialization of sustainable innovations developed by members of our very own �鶹��Ƶ community.”

The charging stations will also serve as a living lab to test future thermal innovations jointly developed by �鶹��Ƶ Engineering researchers and Jule.

“Having these chargers on campus enables us to have a greater capacity to test the system in ways we are limited by doing in a lab setting,” says Da Silva.

Geoscientists confirm 'dripping' of Earth’s crust beneath Türkiye's Central Anatolian Plateau

Christopher.Sorensen — Wed, 18 Sep 2024 10:35:54 +0000

Geoscientists confirm 'dripping' of Earth’s crust beneath Türkiye's Central Anatolian Plateau

Christopher.Sorensen Wed, 09/18/2024 - 06:35

Cutline

Earth scientists have identified active sinking at the Konya Basin in Türkiye due to the dripping of lithospheric material beneath the planet’s surface over millions of years (photo by temizyurek/Getty Images)

Sean Bettam

Topic

Faculty of Arts & Science

Earth Sciences

Global

Recent satellite data reveal that the Konya Basin in the Central Anatolian Plateau of Türkiye is continually being reshaped over millions of years, according to a new analysis led by Earth scientists at the University of Toronto.

The researchers say experimental simulations – combined with geological, geophysical and geodetic data – explain the enigmatic sinking of the basin within the rising plateau interior and further suggests a new class of plate tectonics that has implications for other planets that do not have Earth-like plates such as Mars and Venus.

The study, published in Nature Communications, shows the sinking in the region is due to multi-stage lithospheric dripping – a phenomenon named for the instability of rocky material that makes up Earth’s crust and upper mantle. As dense rock fragments beneath the surface detach and sink into the more fluid layer of the planet’s mantle, major landforms such as basins and mountainous folding of the crust form at the surface.

“Looking at the satellite data, we observed a circular feature at the Konya Basin where the crust is subsiding or the basin is deepening,” says lead author Julia Andersen, a PhD candidate in �鶹��Ƶ’s department of Earth sciences in the Faculty of Arts & Science.

“This prompted us to look at other geophysical data beneath the surface where we saw a seismic anomaly in the upper mantle and a thickened crust, telling us there is high-density material there and indicating a likely mantle lithospheric drip.”

Artist’s impression of the multi-stage lithospheric dripping process in Central Anatolia (illustration by Nevena Niagolova)

The results echo a similar investigation by the researchers into the formation of the Arizaro Basin in the Andes Mountains of South America, suggesting the phenomenon can occur anywhere on the planet and explains tectonic processes typically found within mountain plateau regions.

Past studies show the Central Anatolian Plateau has risen by as much as one kilometre over the past 10 million years because of the lithospheric dripping phenomenon.

“As the lithosphere thickened and dripped below the region, it formed a basin at the surface that later sprang up when the weight below broke off and sank into the deeper depths of the mantle,” says Russell Pysklywec, a professor in the department of Earth sciences and a co-author of the study.

“We now see the process is not a one-time tectonic event and that the initial drip seems to have spawned subsequent daughter events elsewhere in the region, resulting in the curious rapid subsidence of the Konya Basin within the continuously rising plateau of Türkiye.”

Andersen adds that the new findings suggest a connection between plateau uplift and basin formation events through the evolution of primary and secondary lithospheric removal. “Essentially, subsidence is occurring alongside the ongoing uplifting of the plateau.”

Andersen and study co-authors, including colleagues at Istanbul Technical University and Çanakkale Onsekiz Mart University in Türkiye, arrived at their findings after recreating the dripping process in laboratory experiments and analyzing their observations.

They built laboratory analogue models to establish how the process may have unfolded based on the data provided by the new measurements, filling a plexiglass tank with polydimethylsiloxane (PDMS) – a silicone polymer fluid approximately 1,000 times thicker than table syrup – to serve as Earth’s fluid lower mantle, adding a mixture of PDMS and modelling clay to replicate the upper-most solid section of the mantle, finishing with a sand-like layer on top made from ceramic and silica spheres to serve as Earth’s crust.

Artist’s impression of two types of lithospheric drip: one produces thickening and uplift of Earth’s crust, while the other results in the formation of a basin at the surface without horizontal deformation (illustration by Julia Andersen/University of Toronto)

The researchers activated the model by inserting a high-density seed into the PDMS and modelling clay layer to initiate a drip that was subsequently pulled downward by gravity. A set of cameras were positioned above and beside the tank to record any changes over time, capturing a high-resolution image roughly every minute.

“Within 10 hours, we observed an initial phase of dripping, which we call a primary drip. After that primary drip touched the bottom of the box, we saw a second drip had begun to sink to the bottom after 50 hours,” says Andersen. “Both the primary and secondary drip were not causing any horizontal deformation in our artificial crust, which we expect is typically associated with a mantle lithospheric drip.”

The researchers already knew that the primary drip had caused changes in surface topography of the experiment, and wanted to know if the secondary drip would have any effect on the surface since it was a smaller sized drip than the primary drip. “What we noticed was that over time, this secondary drip did pull the crust downward and started to create a basin, despite no horizontal movements in the crust at the surface,” Andersen says. “The findings show these major tectonic events are linked, with one lithospheric drip potentially triggering a host of further activity deep in the planetary interior.”

'Narrative reversal' is key to telling a great story in books, films and TV shows: Study

Christopher.Sorensen — Tue, 17 Sep 2024 14:59:38 +0000

'Narrative reversal' is key to telling a great story in books, films and TV shows: Study

Christopher.Sorensen Tue, 09/17/2024 - 10:59

Cutline

(photo by Klaus Vedfelt/Getty Images)

Topic

Rotman School of Management

Subheadline

Researchers found that works featuring changes of fortune, or turning points, were more popular and received better audience reviews

Writers and scholars have long debated what makes for a great story, but Samsun Knight wanted to see whether there was a way to empirically determine which stories will be snore fests and which will leave audiences hungry for more.

Using a scientist’s tools, the novelist and economist found that “narrative reversals,” or peripeteias, were the key factor – lots of them and the bigger the better.

Samsun Knight (supplied image)

Commonly known as changes of fortune or turning points, where characters’ fortunes swing from good to bad and vice versa, Knight and his colleagues found that stories rich in these mechanisms boosted popularity and engagement with audiences through a range of media, from television to crowdfunding pitches.

“The best-written stories were always either ‘building up’ a current reversal, or introducing a new plot point,” says Knight, an assistant professor of marketing at the University of Toronto’s Rotman School of Management.

“In our analysis, the best writers were those that were able to maintain both many plot points and strong build-up for each plot point across the course of the narrative.”

The research, co-authored with Matthew D. Rocklage and Yakov Bart of Boston’s Northeastern University, was recently published in the journal Science Advances.

For the study, the researchers analyzed nearly 30,000 television shows, movies, novels, and crowdfunding pitches using computational linguistics, a blend of computer science and language analysis. The approach allowed them to quantify not only the number of a reversals in a text but also their degree or intensity by assigning numerical values to words based on how positive or negative they were.

Movies and television shows with more and bigger reversals were better rated on the popular ratings site IMDb. Books with the most and biggest reversals were downloaded more than twice as often as books with the fewest reversals from the free online library Project Gutenberg. And GoFundMe pitches with more and larger reversals were as much as 39 per cent more likely to hit their fundraising goals.

The Greek philosopher Aristotle was the first to identify peripeteia as a key feature of a good story, with Oedipus Rex serving as a classic example. Other thinkers have since added their ideas, including American playwright and dramaturg Leon Katz, whose scholarship particularly inspired Knight’s research.

“[Katz] described the reversal as the basic unit of narrative – just as a sentence is the basic unit of a paragraph, or the syllogism is the basic unit of a logical proof,” Knight says.

In addition to helping psychologists understand how narrative works to educate, inform and inspire people, the findings may also benefit storytellers of all kinds.

“Hopefully our research can help build a pedagogy for writers that allows them to rely on the accumulated knowledge of Aristotle et al. without having to reinvent the wheel on their own every time,” says Knight.

That includes himself. With another novel on the way, he was recently working on a chapter with a big reveal.

“I realized that this drop might hit harder if I gave the character more positive moments before pulling the rug out from under them.”

Researchers' lab technique could speed forensic analysis in sexual assault cases

Christopher.Sorensen — Tue, 17 Sep 2024 14:43:28 +0000

Researchers' lab technique could speed forensic analysis in sexual assault cases

Christopher.Sorensen Tue, 09/17/2024 - 10:43

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(photo by Science Photo Library/Getty Images)

Chris Sasaki

Topic

Centre for Research and Applications in Fluidic Technologies

Institute of Biomedical Engineering

Donnelly Centre for Cellular & Biomolecular Research

Chemistry

Faculty of Arts & Science

�鶹��Ƶ Mississauga

A team of researchers has developed a new approach to analyzing DNA evidence in sexual assault cases – one that could reduce lengthy delays in the processing of evidence.

While there are almost half a million sexual assaults in Canada every year, many more go unreported because victims are reluctant to come forward.

One of the reasons cited by victims is that analysis of forensic evidence is too slow.

Mohamed Elsayed (supplied image)

“For this research, we read reports and surveys that asked victims why they weren’t reporting assaults,” says the study’s lead author Mohamed Elsayed, who worked on the project as part of his PhD in biomedical engineering at the University of Toronto. “And the most common answer was that they didn't have confidence in the justice system – and that lack of confidence was partly because of how long the process takes.”

Elsayed, now a post-doctoral researcher in the department of chemistry in the Faculty of Arts & Science, co-authored the study with, among others, Leticia Bodo, a master’s student in the department of chemistry, and Aaron Wheeler, a professor in the department of chemistry, the Institute of Biomedical Engineering and the Centre for Research and Applications in Fluidic Technologies, a �鶹��Ƶ institutional strategic initiative.

All three researchers are also affiliated with the Donnelly Centre for Cellular and Biomolecular Research.

Processing forensic evidence in sexual assault cases is a technical, multi-step process that involves collecting DNA evidence and sending it to a well-equipped forensic laboratory for analysis by a skilled technician. Once there, the sample is first processed to isolate the assailant’s DNA from the victim’s so the assailant’s DNA can then be analyzed and used to identify a suspect.

The entire process can take days, weeks or longer. Most of that time is taken up with transporting the evidence to the lab, where its analysis can be further delayed depending on how many other cases are being investigated.

To speed things up, researchers focused on the first step: separating two individuals’ DNA from a single sample. At present, this is usually done manually by trained and experienced experts.

Elsayed and his collaborators, by contrast, developed a process called ’differential digestion” using digital microfluidics that helped simplify the overall process and reduce the number of manual steps needed to isolate the assailant’s DNA from 13 to five. “Also, because micro-fluidic processes tend to be faster, we expect that one of the eventual benefits will be shortening the overall time needed,” says Elsayed.

What’s more, the new approach could lead to a mobile solution that no longer requires a lab. For example, testing could be done at a hospital, circumventing the lab’s queue.

The new technique, described in a paper published in the journal Advanced Science, is compatible with the technology known as Rapid DNA analysis that is already in use for the second step of identifying an individual from their DNA. The study’s authors, which included researchers from �鶹��Ƶ Mississauga’s forensic science program, say the long-term goal is to integrate the two technologies to make the process even more streamlined.

While there remain several challenges to deploying the new technique, Elsayed says he is confident they can be overcome and has turned his efforts toward making it widely accessible and commercially viable.

“Our plan is to develop an instrument that will do in five minutes what currently takes 45,” says Elsayed. “And to run many more samples than previously. Once we do that, the next step would be to introduce the technology to forensic labs and hospitals.

“It will take years, but the potential is very exciting.”

The research was supported by the ANDE Corporation and NSERC Alliance Society.

"I’m grateful to NSERC for having the foresight to establish the ‘Alliance Society’ program which has a mission to ‘address a societal challenge that will result in new natural sciences and engineering knowledge and societal impact,” Wheeler says.

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Forensic Science

Researchers develop new method for delivering RNA and drugs into cells

Christopher.Sorensen — Mon, 16 Sep 2024 15:02:15 +0000

Researchers develop new method for delivering RNA and drugs into cells

Christopher.Sorensen Mon, 09/16/2024 - 11:02

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PhD candidate Kai Slaughter, left, and University Professor Molly Shoichet are exploring how ionizable drugs can be used to co-formulate small interfering RNA (siRNA) for more effective intracellular delivery (supplied images)

Qin Dai

Topic

Institute of Biomedical Engineering

Princess Margaret Cancer Centre

Donnelly Centre for Cellular & Biomolecular Research

University Health Network

Subheadline

"This could be a game-changer for treating complex conditions where targeting multiple pathways is beneficial, such as cancer and viral infections"

Researchers at the University of Toronto and its hospital partners have developed a method for co-delivering therapeutic RNA and potent drugs directly into cells, potentially leading to a more effective treatment of diseases.

The research, published recently in the journal Advanced Materials, explores how ionizable drugs can be used to co-formulate small interfering RNA (siRNA) for more effective intracellular delivery.

The team – including Molly Shoichet, the study’s corresponding author and a University Professor in �鶹��Ƶ’s department of chemical engineering and applied chemistry in the Faculty of Applied Science & Engineering – specifically targeted drug-resistant cells with the delivery of a relevant siRNA. The siRNA was discovered study co-author and collaborator David Cescon, a clinician scientist at the Princess Margaret Cancer Centre, University Health Network, and an associate professor in �鶹��Ƶ’s Temerty Faculty of Medicine.

“We found that our co-formulation method not only potently delivered siRNA to cells but also simultaneously delivered active ionizable drugs,” said research lead author Kai Slaughter, a PhD candidate in Shoichet’s lab.

“This could be a game-changer for treating complex conditions where targeting multiple pathways is beneficial, such as cancer and viral infections.”

siRNA is a powerful tool in medicine, capable of silencing specific genes responsible for disease, but delivering these molecules into cells without degradation remains a significant challenge. While recent innovations in ionizable lipid design have led to efficiency improvements, traditional nanoparticle formulations are limited in the amount of small molecule drugs they can carry.

When therapeutic formulations are absorbed by cells, small molecule drugs and siRNA are often trapped in small compartments called endosomes, preventing them from reaching their target destination and reducing their effectiveness.

The research team discovered that combining siRNA with ionizable drugs – compounds that change their charge based on pH levels – enhances the stability and delivery efficiency of siRNA inside cells, helping both the siRNA and drug escape the endosome and more effectively reach their destination. This novel method utilizes the protective properties of lipids to safeguard siRNA during its journey through the body and ensure the release of RNA and the drug together within the target cells.

“One of the biggest hurdles in siRNA therapy has been getting these molecules to where they need to go without losing their potency,” Shoichet says.

“Our approach using ionizable drugs as carriers marks a significant step forward in overcoming this barrier, while also showing how drugs and RNA can be delivered together in the same nanoparticle formulation.”

Caution needed when drawing links between improving symptoms and unproven remedies: Study

Christopher.Sorensen — Fri, 06 Sep 2024 16:03:17 +0000

Caution needed when drawing links between improving symptoms and unproven remedies: Study

Christopher.Sorensen Fri, 09/06/2024 - 12:03

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(photo by Oleksandra Yagello/Getty Images)

Sunnybrook Staff

Topic

Sunnybrook Health Sciences Centre

Institute of Health Policy Management and Evaluation

Dalla Lana School of Public Health