Students receive summer research conference awards

woman presenting

At the Faculty of Science’s annual undergraduate summer research conference, students received awards in recognition of oral and poster presentations they gave on summer projects they worked on.

More than 60 students from the Faculties of Science, Health, and Environmental & Urban Change attended the Faculty of Science Summer 2023 Undergraduate Research Conference to present their projects, reflecting work ranging from bee conservation and biochemical innovations to quantum computing and more.

The conference was an opportunity for recipients of other summer undergraduate research awards (including the Natural Sciences and Engineering Research Council of Canada Undergraduate Summer Research Awards, the Dean’s Undergraduate Research Awards, the Earle Nestmann Undergraduate Research Awards and the York Science Scholars Awards) to share projects they have worked on. Students’ presentations were judged by faculty members as well as postdoctoral and graduate students, and the winners for best presentations were announced at the end of the event. Health students were announced in a separate category.

First place winners, from left to right: Hannah Le, Jessica Latimer, Patrick Hewan

The following science students received awards for their oral presentations:

  • Hannah Le, a third-year chemistry student, won first place for the project “Value-Added Vat Orange 3 Dyes for Functional Materials Development,” supervised by Thomas Baumgartner, professor of chemistry;
  • Chiara Di Scipio, a third-year biology student, won second place for the project “Investigating the signaling cascade of a CAPA neuropeptide in the Malpighian tubules of the fruit fly, Drosophila melanogaster,” supervised by Jean-Paul Paluzzi, professor of biology; and
  • Isaac Kogan, a first-year biology student, won third place for the project “Using Machine Learning to Interpret LFIA Results,” supervised by Sergey Krylov, professor of chemistry.

The following science students received awards for their poster presentations:

  • Jessica Latimer, a fourth-year chemistry student, won first place for the project “Practical Accuracy Assessment of Equilibrium Dissociation Constants,” supervised by Sergey Krylov, professor of chemistry;
  • Sarah Powell, a fourth-year physics student, won second place for the project “Theoretical particle physics on quantum computers,” supervised by Randy Lewis, professor of physics and astronomy; and
  • Yash Shrestha, a second-year biology student, won third place for the project “Exploration of altered synaptic pruning in an autism model mouse,” supervised by Steven Connor, professor of biology.

Within the Faculty of Health, the following students received awards:

  • Patrick Hewan, a psychology student, won best oral presentation for the project “Microstructural integrity of the Locus Coeruleus is related to decision-making in older adults,” supervised by Professor Gary Turner; and
  • Mira Bhattacharya, a second-year cognitive science student, won best poster presentation for the project “Neuronal Correlates of Flexible Decision Making,” supervised by Professor Liya Ma.

Read more about the students and their projects in the conference program booklet.

Professor receives $780,000 in CIHR funding

Global health

Professor and York University Research Chair Chun Peng received $780,000 from the Canadian Institutes of Health Research (CIHR) to fund a new project associated with her ongoing research into pre-eclampsia, a pregnancy disorder with a profound impact on maternal and fetal health.

York biology Professor Chun Peng working in her laboratory
Chun Peng

The grant funds a project titled “NLRC5 isoforms in placental development and pathogenesis of pre-eclampsia,” part of Peng’s long-term research goal to better understand pre-eclampsia, which usually develops after 20 weeks of gestation and is characterized by high blood pressure, as well as damage to liver, kidneys or other organs. It is the leading direct cause of maternal and fetal death in the world, with over 75,000 pregnant women and 500,000 infants dying from it each year, according to the Centers for Disease Control and Prevention.

Even if someone survives the disease, it can lead to negative effects on the mother and fetus health during pregnancy, and can have lifelong negative impacts on cardiovascular health for both. The causes of pre-eclampsia are not fully understood, but it is known that abnormal placental development – in particular, the insufficient invasion of placental cells into the uterus to carry out the remodelling of the uterine blood vessels – is a major contributing factor.

The new study builds upon findings from a previous project where Peng and colleagues identified two truncated isoforms of a protein called NLRC5 in human placenta. Preliminary results suggest that these NLRC5 isoforms play important roles in regulating placental development, and they may contribute to the pathogenesis of pre-eclampsia. In this study, her lab will collaborate with researchers from Mount Sinai Hospital and Toronto General Hospital to further examine how NLRC5 exert their functions in the placenta and to determine if their over-expression will lead to the development of pre-eclampsia-like symptoms.

“This project will allow us to understand more of how placenta development is regulated during pregnancy and how the abnormal levels of NLRC5 isoforms may contribute to the development of pre-eclampsia,” says Peng. “We really hope that this can give us some clues on whether a new strategy could be developed to either prevent or treat pre-eclampsia.”

Peng, who had her York Research Chair in Women’s Reproductive Health renewed in 2021, has been conducting research to better understand pre-eclampsia since 1998, and has received several previous CIHR grants – collectively amounting to nearly $3.5 million – to study the disorder.

Passings: William Frisken

Candle light vigil memorial passing

William Frisken, a professor emeritus in York University’s Faculty of Science, passed away at the age of 90 on Aug. 8, after a major stroke.

Frisken, beloved husband, father, grandfather and colleague, was born in Hamilton, Ont., in 1933, and embarked on a life as an experimental high-energy particle physicist, environmental writer and researcher, university professor, amateur musician, maker of fine cherry bookshelves, home handyman and more.

William Frisken
William Frisken

Frisken began his career path towards becoming a prestigious particle physicist when he enrolled at Queen’s University in engineering physics in 1951, graduating in 1956. Shortly after, he worked for the Canadian General Electric Company on the prototype of the CANDU reactor, a heavy-water nuclear reactor used to generate electric power, before returning to Queen’s to work on a master’s degree, which he did by building an apparatus using two scintillation counters to study the angular correlation of nuclear gamma rays.

A graduate scholarship took him to Birmingham, England in the fall of 1957, where he and several colleagues built a bubble chamber (a recently designed piece of experimental equipment) and a “scattering table” using scintillation counters to study the mesons created by proton-proton scattering. After receiving his PhD in the summer of 1960, he and his wife, Frances Frisken, travelled back to Canada where he spent four years teaching physics at McGill University.

Next, Frisken moved to Long Island, N.Y., to work as an associate scientist at Brookhaven National Laboratory, then Cleveland, where he was appointed associate professor at Case Institute of Technology (soon to be amalgamated with Western Reserve University). During these years, he collaborated with physicists from several American universities on experiments that involved scattering short-lived elementary particles like pions and kaons from protons. The aim of these experiments was to help build a better understanding of the fundamental structure of the proton.

Upon returning to Canada again in 1971, Frisken was hired as a professor of physics at York University and went on to join the Institute of Particle Physics (IPP) to promote collaboration in particle physics research among Canadian universities. He became heavily involved in an IPP proposal to build a circular accelerator in which to collide high-energy electrons and protons. While the IPP first planned to develop this collider at the Fermilab in Chicago, the proposal eventually came to fruition as the Hadron-Electron Ring Accelerator (HERA) at the Deutsches Electronen-Synchrotron laboratory in Hamburg, Germany, making Frisken a key player in Canada becoming the first country in the world to support and contribute to HERA.

The IPP was also a major collaborator in the ZEUS experiment, carried out in the HERA collider, which began operation in 1995 and collected data until 2007. He was well known internationally by then for his expertise in designing and constructing unique particle detectors. For ZEUS, he spearheaded the development of a huge laboratory in Markham, Ont., where he and colleagues from McGill and the University of Toronto designed and built several tonnes of specialized calorimeters to measure the energies of particles scattered from HERA electron-proton collisions. These experiments contributed enormously to the understanding of the internal quark and gluon structure of the proton.

Frisken retired from York University in 1996 alongside his wife, Frances, a York professor emerita, who had been at the University as long as he had.

Frisken continued to pursue more physics after he retired, investigating superconducting radio frequency accelerator cavities, and gave his last scientific presentation in 2005. Many undergraduates, graduate students and postdoctoral fellows benefited from Frisken’s knowledge, and all of his colleagues greatly enjoyed the infectious wit with which he communicated his ideas. He is remembered by former colleagues as the designer and builder of state-of-the-art scientific equipment used to conduct experiments at the forefront of the field of elementary particle physics. He subscribed to the idea that “if you can buy the equipment you need for the experiment you plan, someone has probably already done it.”

Frisken wrote a biography of his life in physics, which can be found for free here:

In lieu of flowers, donations can be made in Frisken’s memory to the Bruce Trail Conservancy or a charity of your choice.

Student wins prestigious crystallographic award

Award stock image banner from pexels

Nicholas Bragagnolo, a PhD student in the Department of Chemistry’s Audette Lab at York University, won the 2023 Etter Student Lecturer Award from the American Crystallographic Association (ACA), which represents those working in the branch of science concerned with the structure and properties of crystals.

Nicholas Bragagnolo
Nicholas Bragagnolo

The ACA houses 14 scientific interest groups (SIG), each representing a specific crystallographic discipline or area of interest. Among them is the Canadian Division SIG, which had the opportunity to – along with all other groups – invite one student to present a lecture at an ACA conference and receive an award.

Bragagnolo was selected and – after receiving transportation funding from the ACA Travel Award and the Canadian National Committee for Crystallography’s Larry Calvert Award – attended an ACA meeting in Baltimore in July.

There, he presented a 20-minute lecture titled “Solution characterization of the dynamic conjugative entry exclusion protein TraG,” as part of a session about the future of light sources, and won the Etter Student Lecturer Award. He also received honourable mentions for a three-minute thesis presentation.

The event, and the award, are part of the ACA’s initiative to provide young students and scientists with opportunitues to demonstrate their research achievements and work.

“Overall it was a very successful conference and I’m grateful to my lab members Arnold Apostol and Christina Rodriguez and my supervisor Gerald Audette for their support,” Bragagnolo wrote in a LinkedIn post following the event. “I made many valuable connections as well as new friends and gained a lot of insight into new techniques to help complete my thesis.”

Earlier this year, Bragagnolo was recognized by York University’s Association for Graduate Students in the Biological Sciences (AGSBS) with the People’s Choice Student Talk Award (Session 2) during the AGSBS 49th Annual Biology Symposium. Bragagnoloa presented a talk titled “Structural Studies of the Conjugative Entry Exclusion Protein TraG.”

In 2021, he was awarded a York Graduate Scholarship by the Faculty of Science.

Faculty of Science sees record growth in experiential education

Diverse students working together

Over 2022-23, the Faculty of Science’s experiential education (EE) program has seen record growth, with co-op applications increasing by 180 per cent and internship applications increasing nearly 140 per cent over the previous year. As well, this summer, 110 student opportunities were posted by 21 employers.

“Much of the growth has been due to the efforts of our EE staff and faculty members in establishing connections and proper channels for support and feedback, such as creating our EE Advisory Committee and connecting with the YU Experience Hub, Career Centre and YSpace. We also built a partnership with BioTalent,” said Michael Scheid, associate dean of students in the Faculty of Science.

EE opportunities through the Faculty allow students to deepen their learning and apply theories learned in the classroom to hands-on, paid work experiences. These opportunities consist of co-ops, which allow students to alternate between periods of work experiences and periods of study, and internships, which offer students, who have completed their third year, to start a work placement for four to 16 months before returning to school to finish their degree.

Three students share highlights of the program’s ability to provide a positive and excellent way to learn new technical and collaboration skills, to gain work experience and to expand professional networks.

Wania Khan

Wania Khan
Wania Khan

Biomedical science student Wania Khan is participating in a one-year internship at Sanofi, a health-care and pharmaceutical company, on the Bioprocess Research and Development team, where she is assisting with experiments as part of a vaccine research project.

“The most important learning skill I gained is dexterity, where I was able to take samples directly from fermenters using a syringe while also focusing on clamping and unclamping various tubes without contaminating the culture inside the fermenter promptly,” she said. “This experiential education opportunity has helped me gain new networks and friendships, i.e. working closely with scientists, technicians and other co-ops from different universities and educational backgrounds.”

Alexandria Nelson

Alexandria Nelson
Alexandria Nelson

Biomedical science student Alexandria Nelson is participating in a one-year co-op placement in the quality control stability department at Sanofi. Her responsibilities include handling and managing vaccine inventory and assisting with data analysis.

“So far, my placement has been helpful in understanding what the vaccine manufacturing process is like, which has been even more insightful considering the demand for vaccines throughout the pandemic,” said Nelson. “I’ve also enjoyed getting to know my co-workers and how their career paths have unfolded. I’ve learned that my journey may not be linear, but there will always be opportunities for growth in whatever I choose to pursue.”

Yibin Zheng

Yibin Zheng
Yibin Zheng

Statistics student Yibin Zheng is participating in a research internship in the Department of Applied Mathematics at Hong Kong Polytechnic University. As a research intern, he is responsible for using the Bayesian statistics theory to work with R, a programming language, and help solve statistical problems.

“During this internship, I have enhanced my ability to collaborate with others as a team, such as organizing and distributing research chapters, and conducting discussions,” he said. “I believe this will be very helpful for my future career.”

Students can learn more about the Faculty of Science’s EE opportunities at

Recognizing student influence: Robert J. Tiffin Student Leadership Award winners

a man holding a trophy

Ariana Mah first knew she was going to attend York University’s Glendon College during a tour in high school. 

“I looked around and I decided, ‘This one is my first choice. This is what I’m going to do; this is where I’m going to be,’ ” says Mah, a fifth-year political science major. “It was that moment when I found out that I could have a community here. It’s like a second home.”  

Ariana Mah
Ariana Mah

Despite feeling apprehensive when starting at Glendon, Mah quickly became involved. She entered her first year as a Top Scholar and has since sat on several committees, including serving as the Chair of Glendon’s Student Caucus and as a member of the Faculty Council’s Committee on Academic Standards, Teaching and Learning, where she actively discusses policy planning and academic expectations with her professors and peers.

She has been an undergraduate representative for the Board of Governors since 2022, where she dedicates her time to a multitude of issues, including improving student well-being and advocating for increased diversity at York. Mah also progressed from a section editor of Glendon’s bilingual student newspaper, Pro Tem, to editor-in-chief. 

Her impact has not gone unnoticed. Mah, who also has a certificate in law and social thought, is one of 11 recipients of the Robert J. Tiffin Student Leadership Award, which annually recognizes students whose leadership has contributed to the growth, development and vitality of the University. 

Now in its 11th year, the award was created in honour of Robert J. Tiffin, who served as York University’s vice-president, students, from 2005 to 2012. University members nominate individuals who demonstrate leadership and make valuable contributions to the York community. 

“I’m always impressed by the diversity of ways in which student leadership occurs at York,” says Tiffin. “The importance of active participation in the University, inside and outside the classroom, cannot be overstated. It is through this engagement that student leaders unlock their own potential and empower others to do the same, creating a ripple effect that extends beyond their time at York.” 

Mah is honoured by the nomination and recognition. 

“As a student leader, we don’t necessarily do the work we do for these awards, but it is always nice to be acknowledged for what we put forward,” she says. “Winning this award will encourage me in the coming year to continue to strive for the betterment of student life on campus and for better representation of students, especially undergraduate students.” 

This award recognizes students who have a wide impact on the York community. “We are all grateful for your pride in the institution and desire to be ambassadors for York,” says Yvette Munro, assistant vice-provost, student success. “Your work makes a difference and makes our institution – and, more importantly, the student experience – better.” 

Mah says her involvement at York has helped her find her voice and she is motivated to help other students find theirs as well. 

“The idea of the student voice inspires me and my work,” she says. “I know a lot of my peers are unsure about navigating student leadership or student governance – it’s kind of a scary thing to sit in rooms full of professors or University staff. I want to continue representing those that may not feel comfortable voicing their opinions, but also encourage others to try these things out, too.” 

When thinking ahead to the future, Mah has a few ideas. She says she is interested in eventually pursuing a master’s in journalism, focusing on learning more languages or working within legislature and policy. 

This year’s Robert J. Tiffin Student Leadership Award recipients also include: 

Alita Gideon, master of science, kinesiology and health science: Gideon has served as a class representative and has mentored underrepresented students in science, technology, engineering and math (STEM). She has also served on the York Federation of Students, most recently as the vice-president, equity, commissioner, and her contributions as an undergraduate student mentor have had an impact on individual students, both within the Faculty of Health and across the University. 

Amireza Nikzadfar Goli, honours bachelor of science, kinesiology and health science: Goli was a founder of the Undergraduate Health Research Exploration Program (UHRE) and also helped to found and co-ordinate York University’s first-ever Conference of Undergraduate Health Research. He has also supported students as the Chair of the Student Advisory Committee and served as a student senator with the Faculty of Health. 

Ana Kraljević, bilingual honours bachelor of arts and bachelor of education: Kraljević has served as the president of Glendon’s Student Union. She has also represented the York community as a president’s ambassador and played a key role in the Glendon Tournament, a web-based initiative to help increase student engagement during the COVID-19 pandemic. 

Arman Sadr, bachelor of science, biomedical science: Sadr has been involved with Bethune College since his first year at York, most recently serving as the president of the Bethune College Council, where he represented and supported the growth of the community. Sadr has also served as the executive vice-president and vice-president, athletics, for the council. 

Christina Da Costa, honours specialized bachelor of arts, Indigenous studies: Da Costa has been actively involved with the Indigenous Student’s Association at York (ISAY). She has served as the president and has made various contributions to Indigenous life at York, including as an ISAY representative on the Indigenous Council of York and by planning and hosting the 20th and 21st All Nations Pow Wow.  

Kaye Trishia Canoy, honours bachelor of arts, psychology and linguistics: Canoy has served as both as the president of Calumet College Council and co-president of the Undergraduate Psychology Student Association. She is also the co-founder of Lingua Franca, an initiative that aims to support English as a second language students at York. 

Mohamed Elsayed Elghobashy, bachelor of science, kinesiology and health science: Elsayed Elghobashy has served as the president of the Kinesiology and Health Sciences Student Association and is a co-founder of the Undergraduate Health Research Exploration program. He has been involved in other leadership roles as a student senator, and has been equally active in supporting others in the community. 

Mustafa Abdulkadhim, honours bachelor of science, biomedical science: Abdulkadhim has served as a class representative for STEM courses and has been a member of the Science Student Caucus and volunteered as a research assistant for multiple labs. Abdulkadhim has also been a peer tutor with the Undergraduate Psychology Student Association and a member of the Committee on Examination and Academic Standards. 

Nathi Mbuso Zamisa, master of arts, social and political thought: Zamisa has served as the president of the York University Graduate Students’ Association. He has also served as the Chair of the York Community Housing Association and has been a representative on various committees, including the Advisory Council on Black Inclusion and the Student Representative Roundtable. 

Prabhjee Singh, honours bachelor of science, computer science: Singh has served as the Lassonde Student Government president, where he implemented new policies and organized multiple events. He has also actively participated in the Student Caucus and the Student Representative Roundtable, and has volunteered with York International. 

The recipients’ names will be added to the awards display wall in the Vari Hall Rotunda.

About the award

The Robert Tiffin Student Leadership Awards recognize students whose leadership has contributed to the growth, development and vitality of York University. Established in 2012, these awards are named after Robert Tiffin, who served as York University’s vice-president, students, for nine years. Through his strong leadership, dedication and integrity, Tiffin transformed his operation into one of the most professional student service organizations in the country, serving one of Canada’s largest student populations.

York leads atmospheric scientists in analyzing city’s air pollution 

Panorama of Toronto skyline at sunset in Ontario, Canada

As Toronto gets hotter, muggier and wildfire smoke increasingly wafts through the atmosphere, researchers at York University are leading a team of atmospheric scientists in testing the city’s air pollution from their rooftop Air Quality Research Station for six weeks this summer. 

Cora Young
Cora Young

The research project, Toronto Halogens, Emissions, Contaminants and Inorganics eXperiment (THE CIX), with science lead Associate Professor Cora Young and logistics lead Assistant Professor Trevor VandenBoer, both of York University’s Faculty of Science, is designed to analyze areas of uncertainty in the air we breathe, to better understand what is contributing to the city’s air pollution.  

Preliminary results show the negative impacts on Toronto’s air quality caused by wildfire smoke. Although Toronto’s air pollution has generally been improving over the past few decades, smoke in the city is reversing these improvements. 

Assistant Professor Trevor VandenBoer
Trevor VandenBoer

One of the things the team hopes to understand is how a soupy mix of trace chemicals will sometimes combine to create little-understood, new and changing threats that can contribute to worse air quality, including emissions from products we use every day, such as paint and pesticides and even perfume, greenhouse gases, perfluorocarboxylic acids (known as “forever chemicals”) and particulate matter – tiny particles of smoke, dust, pollen, emissions and fumes. 

“There is still so much we don’t know about what’s impacting the air we breathe and, until we do, it’s difficult to effectively target contaminants that are affecting our air quality now and into the future,” says Young. 

“This project is important, as it allows us to take a robust look at all the pollutants circulating in the air. The Montreal Protocol was successful in helping to fix the ozone layer above us because we knew what to target, but ground-level ozone and other contaminants can still be an issue, particularly spiking on hot summer days, creating poor air quality, which can impact people’s health.”  

Ground-level ozone forms when nitrogen dioxide mixes with volatile organic compounds (VOCs) and sunlight. Although emissions of VOCs from fossil fuels have been declining, consumer and industrial volatile chemical products are an increasing, but understudied, source of VOCs. 

THE CIX project is part of an international field campaign – Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) – across North America, organized by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), with projects in New York City, Chicago, Los Angeles and Toronto. NOAA and NASA launched their massive air quality research summer campaign on Aug. 3, with scientists from NOAA, NASA and 21 universities from three countries. State-of-the-art instruments are being deployed in multiple, co-ordinated research campaigns this month, including at York University, to investigate how air pollution sources have shifted over recent decades.

At York University, researchers from York U, the University of Toronto, the University of York (U.K.), the University of British Columbia, and Environment and Climate Change Canada are already taking readings from a room packed with unique, sophisticated and highly sensitive equipment – some of which was shipped from the U.K. and B.C. – on the roof of the Petrie Science & Engineering Building on York’s Keele Campus. 

The goal of the campaign is to assess air quality across urban centres, to understand what is impacting air pollution and how it’s changing. THE CIX team hopes to better understand several areas that contribute to air pollution in the Greater Toronto Area. 

In addition to the rooftop measurements, the NASA DC-8 flying science laboratory will cruise over campus this month to take air quality readings from higher in the atmosphere to compare with the rooftop readings. 

Data collected by THE CIX will also be compared with key air pollution observations from the recently launched NASA TEMPO instrument, the first geostationary satellite dedicated to air quality over North America. 

Learn more at News @ York.

York researchers examine history of deep-water oxygen in Lake Erie

Boat and wooden house on the lake in Finland

Researchers at York University went searching for the fossilized remains of small insect larvae called chironomids, found in sediment in Lake Erie, to find a history of deep-water oxygen deprivation in the lake that continues today.

“Our results indicate that Lake Erie has suffered declines and depletion of bottom oxygen in the past, including prior to major Euro-American settlements; however, it wasn’t as bad as it is today,” says senior author and Associate Professor Roberto Quinlan of the Faculty of Science.

Retrieval of the box corer containing Lake Erie sediments, from which the sediment cores were retrieved for this study, aboard the Research Vessel (R/V) Lake Guardian, which is owned by the United States Environmental Protection Agency. The R/V Lake Guardian is the largest research vessel in its fleet and conducts environmental monitoring across all five Great Lakes. Photo courtesy of Euan Reavie

If oxygen continues to decrease, Lake Erie will likely see more algal blooms occurring in the future.

Until now, understanding the oxygen dynamics in Lake Erie was more speculative. The current research, led by former York grad student Dmitri Perlov, is novel in that it looked at how an organism, such as chironomid larvae, which is highly sensitive to changing oxygen levels, was affected over the past 150 years.

The researchers studied the presence of these tiny larvae, which metamorphosize into midges as adults, in lake sediment cores from today to before pre-industrial times. They found oxygen depletion rates ramped up as populations increased and agriculture intensified after industrialization in the 1950s, which was likely exacerbated by the development and increased use of phosphorus-rich chemical fertilizers and household detergents. It was particularly bad in the 1960s and ’70s. Water clarity started to improve in the ’80s and ’90s following phosphorus abatement programs initiated in the early 1970s, but oxygen levels have not recovered.

Poor water quality has a lot to do with the lack of deep-water oxygen, which can spur summer algal blooms that can affect the drinking water for millions of people around Lake Erie, and it also means that when there is a temperature inversion, which sends deep waters devoid of oxygen to the surface, it can cause a massive kill-off of fish that can have major effects on commercial fishing.

“Of all the Great Lakes, Lake Erie is the most stressed by human influence and has the poorest water quality, so it is of great interest to both the United States and Canadian federal governments, and all the state and provincial governments that border the Great Lakes,” says Quinlan.

Low oxygen levels at the bottom of the lake can produce a chemical environment where phosphorus, a primary nutrient for algae, is released from the sediments.

“A central pillar of water quality research is trying to control phosphorus. If you get a lake that loses its oxygen and all of this stored phosphorus is released from the sediments, all of these efforts by governments and society to control phosphorus, it’s all undone by this chemical process that releases a huge amount of phosphorus back into the water and fuels algal blooms,” says Quinlan.

This creates conditions for algal blooms, including harmful cyanobacterial blooms, which turns the water blue-green, makes it smell and taste bad, and can be toxic to humans, pets and livestock, making tap water unsafe to drink.

Microscope view of a subfossil chironomid head capsule. This specimen belongs to the Tanytarsini. Photo courtesy of Dmitri Perlov

“Our study’s results emphasize the vulnerability of Lake Erie to low oxygen because it naturally had periods of low oxygen prior to large-scale European settlement, urbanization, industrialization, agricultural fertilizers and all these additional stressors that make Lake Erie that much more vulnerable to low oxygen,” says Quinlan.

Climate change is what really concerns Quinlan. A warmer climate means warmer winters and shorter ice coverage as well as warmer summers, which causes a further loss of oxygen in the deep layers.

“Climate warming is already underway, and this is something that will take decades to reverse,” he says.

Some 13.2 million people live within the Lake Erie watershed, the most populated of the Great Lakes, representing about 34 per cent of the total population in the Great Lakes catchment area.

Lake Erie is a bellwether for other Great Lakes, as it has changed the most in response stress and remediation. The researchers say that wide-scale watershed actions are needed if Lake Erie’s water quality and deep-water oxygen levels are to improve.

The paper, “Anthropogenic stressor impacts on hypolimnetic dissolved oxygen in Lake Erie: a chironomid-based paleolimnological assessment,” was published in the Journal of Great Lakes Research.

Learn more at News @ York.

York astrophysicists take step forward in computer simulations of cosmology

York University and an international team of astrophysicists have made an ambitious attempt to simulate the formation of galaxies and the cosmic large-scale structure throughout staggeringly large swaths of space.

First results of their “MillenniumTNG” project are published in a series of 10 articles in the journal Monthly Notices of the Royal Astronomical Society. The new calculations help to subject the standard cosmological model to precision tests and to unravel the full power of upcoming new cosmological observations, say the researchers including York Assistant Professor Rahul Kannan of the Faculty of Science.

Over the past decades, cosmologists have gotten used to the perplexing conjecture that the universe’s matter content is dominated by enigmatic dark matter and that an even stranger dark energy field, that acts as some kind of anti-gravity, accelerates the expansion of today’s cosmos. Ordinary baryonic matter makes up less than five per cent of the cosmic mix, but this source material forms the basis for the stars and planets of galaxies like our own Milky Way.

This seemingly strange cosmological model is known under the name LCDM. It provides a stubbornly successful description of a large number of observational data, ranging from the cosmic microwave background radiation – the rest-heat left behind by the Big Bang – to the “cosmic web,” where galaxies are arranged along an intricate network of dark matter filaments. However, the real physical nature of dark matter and dark energy is still not understood, prompting astrophysicists to search for cracks in the LCDM theory. Identifying tensions to observational data could lead to a better understanding of these fundamental puzzles about the universe. Sensitive tests are required that need both: powerful new observational data as well as more detailed predictions about what the LCDM model actually implies.

MillenniumTNG is tracking the formation of about one hundred million galaxies in a region of the universe around 2400 million light-years across
Figure 1: Projections of gas (top left), dark matter (top right), and stellar light (bottom center) for a slice in the largest hydrodynamical simulation of MillenniumTNG at the present epoch. The slice is about 35 million light-years thick. The projections show the vast physical scales in the simulation from size, about 2400 million light-years across, to an individual spiral galaxy (final round inset) with a radius of ~150 000 light-years. The underlying calculation is presently the largest high-resolution hydrodynamical simulation of galaxy formation, containing more than 160 billion resolution elements © MPA

An international team of researchers led by the Max Planck Institute for Astrophysics (MPA) in Germany, Harvard University in the U.S., Durham University in the U.K., and the Donostia International Physics Center in Spain, along with York University, have now managed to take a decisive step forward on the latter challenge. Building up on their previous successes with the “Millennium” and “IllustrisTNG” projects, they developed a new suite of simulation models dubbed “MillenniumTNG,” which trace the physics of cosmic structure formation with considerably higher statistical accuracy than what was possible with previous calculations.

Large simulations including new physical details

The team utilized the advanced cosmological code GADGET-4, custom-built for this purpose, to compute the largest high-resolution dark matter simulations to date, covering a region nearly 10 billion light-years across. In addition, they employed the moving-mesh hydrodynamical code AREPO to follow the processes of galaxy formation directly, throughout volumes still so large that they can be considered representative for the universe as a whole. Comparing both types of simulations allows a precise assessment of the impact of baryonic processes related to supernova explosions and supermassive black holes on the total matter distribution. An accurate knowledge of this distribution is key for interpreting upcoming observations correctly, such as so-called weak gravitational lensing effects, which respond to matter irrespective of whether it is of dark or baryonic type.

Furthermore, the team included massive neutrinos in their simulations, for the first time in simulations big enough to allow meaningful cosmological mock observations. Previous cosmological simulations had usually omitted them for simplicity, because they make up at most one to two per cent of the dark matter mass, and since their nearly relativistic velocities mostly prevent them from clumping together. Now, however, upcoming cosmological surveys (such as those of the recently launched Euclid satellite of the European Space Agency) will reach a precision allowing a detection of the associated per cent-level effects. This raises the tantalizing prospect to constrain the neutrino mass itself, a profound open question in particle physics, so the stakes are high.

For their groundbreaking MillenniumTNG simulations, the researchers made efficient use of two extremely powerful supercomputers, the SuperMUC-NG machine at the Leibniz Supercomputing Center in Garching, and the Cosma8 machine at Durham Universe. More than 120,000 computer cores toiled away for nearly two months at SuperMUC-NG, using computing time awarded by the German Gauss Centre for Supercomputing, to produce the most comprehensive hydrodynamical simulation model to date. MillenniumTNG is tracking the formation of about 100 million galaxies in a region of the universe around 2,400 million light-years across (see Figure 1). This calculation is about 15 times bigger than the previous best in this category, the TNG300 model of the IllustrisTNG project.

Using Cosma8, the team computed an even bigger volume of the universe, filled with more than a trillion dark matter particles and more than 10 billion particles for tracking massive neutrinos (see Figure 2). Even though this simulation did not follow the baryonic matter directly, its galaxy content can be accurately predicted in MillenniumTNG with a semi-analytic model that is calibrated against the full physical calculation of the project. This procedure leads to a detailed distribution of galaxies and matter in a volume that, for the first time, is large enough to be representative for the universe as a whole, putting comparisons to upcoming observational surveys on a sound statistical basis.

For more on the research results, and to see the published articles, visit the full story at News@York.

Research study by chemistry professor wins prestigious award

a man holding a trophy

A research study led by chemistry Professor Christine Le, titled “Synthesis of Carbamoyl Fluorides Using a Difluorophosgene Surrogate Derived from Difluorocarbene and Pyridine N-Oxides,” was honoured with the 2023 Outstanding Publication of the Year Award from The Journal of Organic Chemistry.

Christine Le
Christine Le

The award recognizes a paper from the previous year that demonstrates creativity and impact in the field of organic chemistry, with a focus on early-career researchers. “This publication was my first independent paper, so it feels incredibly rewarding to have our chemistry already recognized for its impact on the community,” said Le, who co-authored the study with York doctoral student Dusty Cadwallader, master of science alumni Tristan R. Tiburcio, and undergraduate student George A. Cieszynski. The paper was also among the top six most read articles in the journal in 2022.

Le’s research study presents an innovative approach to making molecules called carbamoyl fluorides in an efficient way that avoids the use of light-, moisture-, temperature-, and shock-sensitive reagents. Her findings expand the toolbox for chemists interested in making and using carbamoyl fluorides for research and drug development, including employing them in reactions to add fluorine to medicinal compounds, as demonstrated in a recently published study by Le and colleagues in the Journal of the American Chemical Society.

“Adding fluorine to a drug molecule can drastically improve its medicinal properties, by making it more potent and stable for instance,” said Le. “In fact some of the most widely prescribed medicines contain fluorine, and developing new ones is an area of pursuit for researchers in the pharmaceutical industry.”

By following the reactions outlined in Le’s paper, chemists can now easily create carbamoyl fluorides in a laboratory setting, which will allow researchers to further study their applications in organic synthesis, medicinal chemistry, and drug development.

The research team will be honoured in August during a symposium at the American Chemical Society National Meeting in San Francisco, California.

Read the journal’s award announcement here.