Here are some interesting new stories from McGill University Media Relations:
Environment
Lower-income populations will be hardest hit by heat waves | Global environmental risks and treated wastewater | Higher levels of air pollution in snowbound cities | Projecting climate change more accurately | Herbicide Roundup disturbing freshwater biodiversity | Mapping the genome of lake trout to ensure its survival | Why do species live where they do? | Invasive insects will kill 1.4 million US street trees by 2050 | Sustainable strategies to treat urban runoff | Unlocking the secrets of killer whale diets and their role in climate change
Unlocking the secrets of killer whale diets and their role in climate change
Killer whale populations are invading the Arctic, causing significant disruptions to an ecosystem already deeply affected by climate change. A team of McGill researchers has discovered new clues to understand how killer whales impact their environment - by reconstructing their diets using the lipids in their blubber.
"Using this analysis, we will better understand how their diets change and how they may potentially disrupt Arctic food webs," said Anaïs Remili, a PhD candidate at McGill's Department of Natural Resource Sciences and lead author on the study.
To reconstruct the whales' diets, the researchers used a model called Quantitative Fatty Acid Signature Analysis (QFASA) using samples from captive killer whales. They then measured the fatty acid composition of the wild Greenland killer whales and potential prey species the whales may feed on. Finally, they applied the modeling approach to estimate that the whales mainly feed on harp and hooded seals, species that researchers found in some of the whales' stomachs.
This new tool has the potential to improve understanding of diets of killer whales around the world, and how killer whales might impact Arctic food webs in the future.
Validation of quantitative fatty acid signature analysis for estimating the diet composition 2 of free-ranging killer whales by Anaïs Remili et al., was published in Nature.
Sustainable strategies to treat urban runoff
As urban areas increase, so does urban runoff, directly impacting surface water quality and storage. We know the lakes and rivers in and around urban environments contain plastic debris, detergents, pesticides, heavy metals, and other contaminants. This can cause acute toxicity to aquatic organisms, or even present a chronic risk to ecosystems and to humans via seafood and drinking water. For example, urban runoff mortality syndrome is a phenomenon that describes mass die-offs in salmon in the Pacific Northwest due to untreated stormwater.
New research is showing that urban runoff toxicity is ill-defined and potentially underestimated globally. Researchers including Mathieu Lapointe, postdoctoral researcher at McGill University, and Nathalie Tufenkji, Professor of Chemical Engineering at McGill University and Canada Research Chair in Biocolloids and Surfaces, are calling for cities to better manage and treat urban runoff to protect sources of drinking water and reduce the impacts on aquatic ecosystems.
The researchers argue that international actions and policies should be implemented to control pollutant release and prevent adverse ecological impacts. "Densely populated cities need sustainable solutions such as retention ponds and settling tanks to simultaneously treat and store runoff," said Lapointe and Tufenkji. "Such retention processes could act as on-site surge tanks while also removing several contaminants from runoff before discharge into natural waters."
"Sustainable strategies to treat urban runoff needed" by Nathalie Tufenkji, Mathieu Lapointe, and Chelsea M. Rochman was published in Nature Sustainability.
Invasive insects will kill 1.4 million US street trees by 2050: study
A new study by researchers from McGill University, the USDA Forest Service Southern Research Station and North Carolina State University estimates that over the next 30 years, 1.4 million street trees will be killed by invasive insects, costing over $900 million USD to replace. The findings are published in the British Ecological Society's Journal of Applied Ecology.
McGill PhD graduate Emma J. Hudgins , the study's lead author, created the first nationwide spatial forecast of street tree mortality from invasive insects, building models to extrapolate to roughly 30,000 urban areas across the United States. Now a post-doctoral fellow at Carleton University, Hudgins puts forth that 90 per cent of the 1.4 million tree deaths forecasted in the study are predicted to be caused by the emerald ash borer (Agrilus planipennis), which is expected to kill virtually all ash trees in more than 6,000 urban areas. The researchers predict that the impact of invasive insects will not be evenly spread across the country, with less than a quarter of US communities set to experience 95 per cent of all street tree mortality resulting from invasive insects.
The team says that their findings can help urban tree managers to know which tree species, in which areas, will be at the greatest risk from invasive insects. Their findings can be used to prioritize management efforts such as quarantining wood products. "These results can hopefully provide a cautionary tale against planting a single species of tree throughout entire cities, as has been done with ash trees in North America. Increasing urban tree diversity provides resilience against pest infestations," Hudgins said.
"Hotspots of pest-induced US urban tree death, 2020-2050" by Emma J. Hudgins et al. was published in the Journal of Applied Ecology.
Lower-income populations will be hardest hit by heat waves
The poorest parts of the world are likely to be two to five times more exposed to heat waves than richer countries by the 2060s, according to a new study led by Professor Jan Adamowski and Mohammad Reza Alizadeh from the Department of Bioresource Engineering. By the end of the century, the heat exposure of the poorest quarter of the global population will match that of the entire rest of the world.
To assess how heat wave exposure is changing, the researchers analyzed heat waves around the world over the past 40 years and then used climate models to project ahead. They also incorporated estimates of countries' ability to adapt to rising temperatures and lower their heat exposure risk. The researchers found that while wealthy countries can buffer their risk by rapidly investing in measures to adapt to climate change, the poorest quarter of the world will face escalating heat risk. Compared to the wealthiest quarter of the world, the poorest quarter lags in adapting to rising temperatures by about 15 years on average. The results provide more evidence that investing in adaptation worldwide will be crucial to avoid climate-driven human disasters, the researchers say.
"Increasing Heat-Stress Inequality in a Warming Climate" by Mohammad Reza Alizadeh et al. was published in Earth's Future.
Global environmental risks and treated wastewater
Surprisingly, wastewater, even when treated, can represent sources of concentrated pollution, including from household pharmaceuticals. To investigate the impact of wastewater effluents on the water quality of receiving waterbodies, scientists need to know where and how much wastewater is being released from treatment plants. McGill University scientists have compiled a new global database showing the locations and characteristics of 58,502 wastewater treatment plants around the world. Using this new information, Heloisa Ehalt Macedo, a PhD student in the Department of Geography at McGill, and the research team identified 1.2 million km of rivers that receive treated wastewater discharge from these plants. This may pose a contamination risk if the wastewater is not treated adequately as some of the rivers that were investigated exceed a common threshold for environmental concern linked to wastewater dilution. This research is a first step towards identifying hotspots that are at greatest risk for water pollution from emerging contaminants such as household pharmaceuticals. It is also a step along the way to pinpointing individual treatment plants where improvements in treatment capability is critical to mitigate environmental risks.
"Distribution and characteristics of wastewater treatment plants within the global river network" by Ehalt Macedo et al was published in Earth System Science Data.
Higher levels of air pollution in snowbound cities
Snowbound cities such as Montreal have higher concentrations of black carbon, a powerful air pollutant, than cities in warmer climates according to researchers Houjie Li and Professor Parisa Ariya of the Department of Atmospheric and Oceanic Sciences and the Department of Chemistry. This is because particles of black carbon produced by diesel and other fossil fuels are transferred to surfaces through snow and then re-emitted to the atmosphere. Consequently, the same carbon emission rates in a warmer city can produce a much higher concentration of pollutants in a colder city. In comparing two pollution hotspots in Montreal, the researchers also found that concentrations of black carbon were 400% higher at the Montreal airport than in downtown Montreal. The study also points out that air quality norms around the world do not take into account the fact that cold climate conditions pose a particular threat to public health. Interestingly, the research also shows that during the COVID-19 lockdown period which started in March 2020, concentrations of black carbon in downtown Montreal decreased up to 72%, revealing that human activities accounted for most air pollutants.
"Black Carbon Particles Physicochemical Real-Time Data Set in a Cold City: Trends of Fall-Winter BC Accumulation and COVID-19" by Houjie Li et al. was published in the Journal of Geophysical Research-Atmospheres.
Projecting climate change more accurately
Scientists have been making projections of future global warming using powerful supercomputers for decades. But how accurate are these predictions? Modern climate models consider complicated interactions between millions of variables. They do this by solving a system of equations that attempt to capture the effects of the atmosphere, ocean, ice, land surface and the sun on the Earth's climate. While the projections all agree that the Earth is approaching key thresholds for dangerous warming, the details of when and how this will happen differ greatly depending on the model used. Now, researchers from McGill University, including Professor Shaun Lovejoy and Roman Procyk of the Department of Physics hope to change all that. Building on an approach pioneered by Nobel prize winner Klaus Hasselmann, they have developed a new way to measure climate change more accurately and precisely. Their new projections are based on equations that combine the planet's energy balance and slow and fast atmospheric processes called "scaling". This breakthrough opens new avenues of research on future and past climates on Earth, including ice ages. The new model can even be used to make precise regional temperature projections. By comparing their projections to the conventional ones used by Intergovernmental Panel on Climate Change, the researchers found that the new model gives overall support to the IPCC projections but with some significant differences. While the new model projects a crossing of the key thresholds for dangerous warming a bit later, the time frame for crossing it is much narrower. According to the researchers, there is a 50% chance of exceeding the 1.5C threshold by 2040.
"The Fractional Energy Balance Equation for Climate projections through 2100" by Roman Procyk et al. was published in Earth System Dynamics.
Herbicide Roundup disturbing freshwater biodiversity
As Health Canada extends the deadline on public consultation on higher herbicide concentrations in certain foods, research from McGill University shows that the herbicide Roundup, at concentrations commonly measured in agricultural runoff, can have dramatic effects on natural bacterial communities. "Bacteria are the foundation of the food chain in freshwater ecosystems. How the effects of Roundup cascade through freshwater ecosystems to affect their health in the long-term deserves much more study," say the researchers.
"Resistance, resilience, and functional redundancy of freshwater bacterioplankton communities facing a gradient of agricultural stressors in a mesocosm experiment" was published in Molecular Ecology.
Mapping the genome of lake trout to ensure its survival
An international team of researchers from the U.S. and Canada, including researchers from McGill University, have managed to create a reference genome for lake trout to support U.S. state and federal agencies with reintroduction and conservation efforts. Lake trout, once the top predator fish across the Great Lakes, reached near extinction between the 1940s and 1960s due to pollution, overfishing, and predation by the invasive lamprey eel. Once showing striking levels of diversity in terms of size, appearance, and ability to adapt to varied environments, now the only lake trout populations to have survived are to be found in Lake Superior and Lake Huron. Genomes of salmonids, a family that includes lake trout, are harder to compile than those of many other animals, the research team said. "Between 80-100 million years ago, the ancestor of all salmonid species that lake trout belong to went through a whole genome duplication event. As a result, salmonid genomes are difficult to assemble due to their highly repetitive nature and an abundance of duplicated genomic regions with similar sequences," explains Ioannis Ragoussis, the Head of Genome Sciences at the McGill Genome Centre, where the sequencing took place.
"A chromosome-anchored genome assembly for Lake Trout (Salvelinus namaycush)" was published in Molecular Ecology Resources.
Why do species live where they do?
As the climate changes, what factors will decide where species can survive and thrive? Scientists try to answer this question by studying what governs where species live today. Harsh and cold environmental conditions play a role, especially toward the poles like in Canada. But researchers Anna Hargreaves, an Assistant Professor in the Department of Biology and Alexandra Paquette show that interactions with other species - like competition and predation - are also major driving factors in determining where species can live, especially in warmer conditions toward the equator.
"Biotic interactions are more often important at species' warm versus cool range edges" was published in Ecology Letters.
Health
Food insecurity and long-term impacts on children's mental health | A dimmer switch for human brain cell growth | Freezable printed human tissue for implants | Predicting coma recovery with 100% accuracy | Enhancing fertility by targeting little-known protein | Mimicking the human aorta | Parkinson's pain and dopamine | Tackling a rare disease identified in Quebec | Rhythms of music and heartbeats | Stress affects our motivation to do difficult tasks | More cost-effective and accessible COVID-19 vaccines
Food insecurity and long-term impacts on children's mental health
Food insecurity in childhood is closely associated with various mental health issues and problems in school at adolescence according to research led by McGill University. A new study found that children who had experienced food insecurity before the age of 13 faced greater academic struggles by age 15, including more bullying and being at higher risk of dropping out. They also were more likely than their peers to use cannabis.
"It is important for healthcare workers and policymakers to be able to better identify at-risk children and their needs, particularly in a context where the COVID-19 pandemic has pushed many households into situations of precarity," says lead author Dr. Vincent Paquin, a psychiatry resident in the Faculty of Medical and Health Sciences. The research was based on comparing the trajectories of 2,032 individuals who were part of the cohort of the Québec Longitudinal Study of Child Development, of whom about 4% of children were at risk of recurrent exposure to food insecurity between infancy and adolescence.
"Longitudinal Trajectories of Food Insecurity in Childhood and their Associations with Mental Health and Functioning in Adolescence" by Vincent Paquin et al published in JAMA Network Open.
A dimmer switch for human brain cell growth
Controlling how cells grow is fundamental to ensuring proper brain development and stopping aggressive brain tumors. The network of molecules that control brain cell growth is thought to be complex and vast, but now McGill University researchers provide striking evidence of a single gene that can, by itself, control brain cell growth in humans.
In a paper published recently in Stem Cell reports, Carl Ernst, an Associate Professor in the Department of Psychiatry at McGill University, and his team have shown that the loss of the FOXG1 gene in brain cells from patients with severe microcephaly - a disease where the brain does not grow large enough - reduces brain cell growth. Using genetic engineering, they turned on FOXG1 in cells from a microcephaly patient to different levels and showed corresponding increases in brain cell growth. They have uncovered a remarkable dimmer switch to turn brain cell growth up or down.
Their research indicates that a single gene could potentially be targeted to stop brain tumour cells from growing. Or that future gene therapy might allow this same gene to be turned up in patients with microcephaly or other neurodevelopmental disorders.
"FOXG1 dose tunes cell proliferation dynamics in human forebrain progenitor cells" by Nuwan C. Hettige et al. was published in Stem Cell Reports.
Freezable printed human tissue for implants
Soft tissue implants are used in everything from vocal folds and breast reconstruction to abdominal wall repair. Scientists have used bioprinted artificial tissues made up of hydrogels, living cells, and other biomaterials to create these implants for over a decade. But bioprinted tissues fabricated via conventional methods must be used immediately after they are printed, limiting their translation into clinical settings. To address this problem, an international team of researchers has developed a new "cryobioprinting" technique by adding a combination of cryoprotective agents to the bioink. The research was led by Hossein Ravanbakhsh, a former PhD student at McGill University, under the supervision of Professors Luc Mongeau (Department of Mechanical Engineering, McGill University) and Yu Shrike Zhang (Harvard Medical School, Brigham and Women's Hospital.) To fabricate the frozen tissue, they printed the bioink onto a freezing plate, which was kept at a constant temperature of -20 °C throughout the printing. The samples were then stored at -196 °C before revival for use as soft implants. Intriguingly, cell viability and cell differentiation experiments after reviving the tissues showed that the cryobioprinted cells remain both alive and functional after 3 months of storage. The "cryobioprinted" cells have not yet been used in clinical applications, but future collaborations are envisioned between researchers and end-users such as clinicians to pave the way for using shelf-ready "cryobioprinted" tissue in clinical applications.
"Freeform cell-laden cryobioprinting for shelf-ready tissue fabrication and storage" by Hossein Ravanbakhsh et al. was published in Matter.
Predicting coma recovery with 100% accuracy: A preliminary study
A McGill-led team has developed a new tool that can predict with 100% accuracy whether patients in a vegetative or coma state will recover consciousness. Traumatic brain injuries and other events where the brain is deprived of oxygen, such as stroke or overdose, may result in a vegetative or coma state. Until now, families and healthcare professionals had little feedback on a person's level of consciousness and chance of recovery. In a preliminary study, the newly developed Adaptive Reconfiguration Index was able to predict in each case whether a patient would recover from an unresponsive state within three months. These results provide families and healthcare professionals with vital information for the difficult clinical decisions that need to be made for the patient. The team of researchers, including Assistant Professor Stefanie Blain-Moraes of the School of Physical and Occupational Therapy, is now preparing for the next phase of studies which will include patients from across the country with newly diagnosed disorders of consciousness.
"Brain Responses to Propofol in Advance of Recovery From Coma and Disorders of Consciousness: A Preliminary Study" by Catherine Duclos et al. was published in the American Journal of Respiratory and Critical Care Medicine.
Enhancing fertility by targeting little-known protein
A team of researchers led by Professor Daniel Bernard of the Department of Pharmacology and Therapeutics has discovered that fertility can be enhanced by knocking out a novel protein. The researchers found that when a protein called TGFBR3L was removed in female mice, the animals ovulated more eggs per cycle and gave birth to increased numbers of pups. This discovery could help identify new drugs to treat infertility in humans. By removing this specific protein, the researchers reduced the effects of a hormone called inhibin B, which normally works to inhibit the production of FSH or follicle-stimulating hormone, a major driver of egg and sperm development. The researchers contend that if inhibin B is impaired from binding to the same protein in humans, it should lead to selective increases in FSH, which could be effective in treating infertility in women and hypogonadism in men.
"TGFBR3L is an inhibin B co-receptor that regulates female fertility" by E. Brule et al. was published in Science Advances.
Micro image of aortic cross-section. Credit: Marco Amabili et al
Mimicking the human aorta
Researchers from McGill University are laying the foundation to develop artificial aortas, capable of mimicking the behaviour of the human body's largest artery. While the aorta is responsible for transporting oxygen rich blood from the heart to the rest of the body, until now scientists knew very little about the effect of smooth muscle activation in these tissues. A new study led by Professor Marco Amabili of the Department of Mechanical Engineering is the first to map out the effects. Their findings will provide crucial information needed to design better aortic grafts, more compatible with the aortas' natural movements, and improve the lives of patients recovering from aneurysms and cardiovascular diseases.
"Role of smooth muscle activation in the static and dynamic mechanical characterization of human aortas" by Marco Amabili et al. was published in Proceedings of the National Academy of Sciences.
Parkinson's pain and dopamine
Millions of people worldwide suffer from chronic pain associated with Parkinson's Disease, yet treating it with opiates comes with serious side effects. A new study reveals a possible alternative. Research from the lab of Philippe Séguéla at The Neuro and McGill University shows that dopamine controls pain perception in rodents. The researchers have shown that dopamine can reduce activity of neurons via a specific receptor, called D1, in an area of the brain known to play an important role in chronic pain, the anterior cingulate cortex. This finding may lead to better analgesic treatments without the side effects of opiates. The novel mechanism may also explain why people with Parkinson's often experience chronic pain, as this neurodegenerative disease destroys cells critical to the production of cortical dopamine.
"Decreased dopaminergic inhibition of pyramidal neurons in anterior cingulate cortex maintains chronic neuropathic pain" by Kevin Lançon et al. was published in Cell Reports.
Tackling a rare disease identified in Quebec
In 2006, Sonia Gobeil and Jean Groleau, learned that their eldest son, who was then three years old, had a rare disease called autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). At the time, there was little research into the disease, which affects coordination and balance from early childhood. Most patients require a wheelchair once they reach their 30s or 40s. Current treatments provide only limited symptomatic relief and there is no known cure.
Although the disease was first identified in Quebec, despite its name, it is seen in patients around the world. Over the past 15 years, thanks to Gobeil and Groleau's determined efforts, the Montreal-based Ataxia Charlevoix-Saguenay Foundation has raised money to support ARSACS research and the growing body of experts who work in the field, including at the Montreal Neurological Institute and McGill. Now, two McGill researchers working in the field have made an important step forward in our understanding of the disease. The research, led by Anne McKinney and Alanna Watt, provides insight into patterns of vulnerability in brain cells in ARSACS patients and suggests that there are disease pathways that are common to ARSACS and other forms of ataxia. Seeing a commonality of mechanisms across multiple diseases is especially important when dealing with rare diseases, according to the researchers. It then becomes possible to explore repurposing drugs and testing from pharmaceutical libraries to see if a particular mechanism helps in all of these disorders.
"Molecular Identity and Location Influence Purkinje Cell Vulnerability in Autosomal-Recessive Spastic Ataxia of Charlevoix-Saguenay Mice" by Brenda Toscano Márquez et al. was published in Frontiers in Neuroscience.
Rhythms of music and heartbeats
When you listen to or perform music, you may notice that you move your body in time with the music. You may also synchronise to music in ways that you are not aware of, such as your heartbeats. Scientists from McGill, led by Caroline Palmer, the Canada Research Chair in Cognitive Neuroscience of Performance, investigated how musicians' heart rhythms change when they perform familiar and unfamiliar piano melodies at different times of day. Contrary to some predictions, they found that musicians' heart rhythms were more predictable and rigidly patterned when they performed unfamiliar melodies, and when they performed early in the morning. These findings suggest that musicians' heart rhythms may be influenced by time of day as well as by how novel or how difficult a performance is. Ultimately, this research can inform us about how to best apply music in therapeutic settings such as in interventions that target abnormal cardiovascular patterns.
"Physiological and behavioural factors in musicians' performance tempo" was published in Frontiers in Human Neuroscience.
Stress affects our motivation to do difficult tasks
Stress increases people's tendency to avoid cognitively demanding tasks, without necessarily altering their ability to perform those tasks according to new research from McGill University. "People are demand-averse," says Ross Otto, an Assistant Professor in the Department of Psychology. "We found that stress increases that aversion." Study participants had to choose between repeating a single task over and over, or the more cognitively demanding process of frequently switching from one kind of task to another. They then compared the choices made by individuals under acute stress against those of a control group. "The interesting thing is - the stress effects didn't come out in performance," Otto explains. "So, it's not that the study participants were worse at either the more demanding or the less demanding task - their performance was no different; it's just that when you give them the choice of whether they want to do one or the other, stress increases their unwillingness to invest effort."
"Acute Psychosocial Stress Increases Cognitive-Effort Avoidance" was published in Psychological Science.
More cost-effective and accessible COVID-19 vaccines
New possibilities for producing more efficient, globally accessible, and pandemic-ready vaccines may exist thanks to the work of a McGill-led research team headed by Amine A. Kamen, a Professor in the Department of Bioengineering. The Vero cell line is considered one of the most effective viral vaccines manufacturing platform for infectious diseases such as MERS-CoV, SARS-CoV and more recently SARS-CoV-2. Over the course of the pandemic, it has emerged as an important discovery and screening tool to support SARS-CoV-2 isolation and replication, viral vaccine production and identification of potential drug targets. However, the productivity of Vero cells has been limited by the lack of a reference genome. With restricted understanding of host-virus interactions, the full characterization of the Vero cell line has remained incomplete until now. The researchers believe that it may be possible to speed up the production of new vaccines against emerging and reemerging infectious diseases, by advanced de novo sequencing and further decoding prior published genomic data highlighting the mechanisms at play during virus growth inside the cells.
"Haplotype-resolved de novo assembly of the Vero cell line genome" was published in npj Vaccines.
Science
Improved maize yields in Tanzania | New type of earthquakes discovered | Uncovering the chemistry of bleach | What shaking a container can teach us about touch | Using origami and kirigami to inspire reconfigurable yet structural materials | Why are male mice afraid of bananas?
Why are male mice afraid of bananas?
Researchers from McGill University have identified a form of chemical signaling in mice to defend their offspring. The researchers found that proximity to pregnant and lactating female mice increased stress hormones in males and even decreased their sensitivity to pain. "The findings have important implications for improving the reliability and reproducibility of experiments involving mice. This is yet another example of a previously unknown factor in the lab environment that can affect the results of scientific studies," says Jeffrey Mogil, a Professor in the Department of Psychology at McGill University and E. P. Taylor Chair in Pain Studies.
According to co-author Sarah Rosen, "what is likely happening is that female mice are signaling to males who might be considering attacking their babies that they will defend them vigorously. It's the threat of the possible upcoming fight that causes the stress."
"Mice have richer communication with one another than we think; it's just that a lot of it's through smell," says Mogil. The researchers started looking for the olfactory chemical responsible. Several odorants were identified, but one, n-pentyl acetate, which is released in the urine of pregnant and lactating female mice, was especially effective at producing stress in male mice. "Curiously, n-pentyl acetate is also responsible for the unique smell of bananas. After a quick trip to the supermarket for some banana oil, we were able to confirm that the smell of banana extract stressed the male mice just as much as the pregnant females," says co-author Lucas Lima.
The finding represents a breakthrough in the science of mammalian social signaling. "There are a number of examples of male-to-female olfactory signaling in rodents, but far fewer examples of female-to-male signaling, especially outside of the realm of sexual behavior," says Mogil.
"Olfactory exposure to late-pregnant and lactating mice causes stress-induced analgesia in male mice" by Sarah Rosen et al. was published in Science Advances.
Caption: Reconfigurable metamaterial that can either fold flat (AO2) in a pattern other than the original (O3), or deploy into two distinct configurations (A2O and A3) that are rigid and load-bearing.
Using origami and kirigami to inspire reconfigurable yet structural materials
Origami, the Japanese art of folding paper into decorative shapes and figures, has long served as inspiration for industrial design. The concept of folding has been used to build reconfigurable structures, which change their function by changing their shape. These structures are promising for applications such as nanorobots for drug delivery, foldable solar panels for aerospace, and morphable cladding and shading for architecture. However, most of these designs cannot bear heavy loads. Those that can are only able to do so in a certain direction, collapsing along the direction in which they fold. This limits their use as structural materials.
A study by a group of McGill University researchers may provide a solution to this limitation. By merging concepts from origami and kirigami, the practice of folding and cutting paper, researchers developed a class of cellular metamaterials that can flat-fold and lock into several positions that remain stiff across multiple directions.
"Their load-bearing capacity, flat-foldability, and reprogrammability can be harnessed for deployable structures including certain submarines, reconfigurable robots, and low-volume packaging," said Damiano Pasini, Professor in the Department of Mechanical Engineering and lead researcher on the study. "Our metamaterials remain stiff in several directions, yet rigidly flat-foldable metamaterials, attributes unprecedented in the current literature."
"Rigidly flat-foldable class of lockable origami-inspired metamaterials with topological stiff states" by Damiano Pasini et al. was published in Nature Communications.
What shaking a container can teach us about touch
We shake cereal boxes and milk cartons to figure out if there is enough for breakfast. We can easily tell if there is enough toothpaste left in the tube, or if we have enough vitamin tablets left in a bottle. For these actions, we rely on our sense of touch (and hearing). New research led by Ilja Frissen, Associate Professor in McGill's School of Information Studies, with Professor Catherine Guastavino, demonstrates a natural human ability to understand how an object moves inside a container, providing new insights into the different kinds of information that can be conveyed through the sense of touch.
In the future, Frissen said, understanding how people can decipher the hidden contents of a container could help create a more natural and comprehensive communication between humans and machines, such as smart devices, as well as educational simulation tools and accessibility technologies for those with visual impairments.
Researchers created a set of five fiberglass tubes that contained a metal ball that could move between two internal walls. Seventeen people participated in this perceptual study. They were asked to figure out how far the ball had rolled inside the tube. In a second experiment, researchers used virtual reality technology to simulate and isolate the various physical cues that occur, such as the ball rolling along a surface or bouncing off an internal wall. "We found that our participants, who received no particular training, were surprisingly accurate in doing this curious task. And thanks to the virtual reality technology we were able to start piecing together how the various physical cues played a role," Frissen said.
Humans sense by touch the location of objects that roll in handheld containers by Ilja Frissen et al., was published in the Quarterly Journal of Experimental Psychology.
Improved maize yields in Tanzania
Given the extra cost, it's understandable that Tanzanian farmers living below the poverty level may be both unable and unwilling to invest in chemical fertilizers to address soil deficiencies. But research from a multidisciplinary team shows that low-cost soil tests and the targeted use of small amounts of the right fertilizers can have a noteworthy impact on farm productivity and profit and significantly improve the yield of maize, the staple food for most Tanzanians.
The researchers, including Aurélie Harou, Assistant Professor in McGill University's Department of Natural Resources Sciences, tested the soil of more than 1,000 plots of land in 50 villages in the Morogoro region, an area with good agricultural potential but low yields of maize. They found that nearly every plot in the study was deficient in sulfur, which is critical for achieving the highest maize yields. The fertilizers the farmers use are, in general, not the ones that are needed to get the best crop response and sulfur is not included in current regional or national fertilizer recommendations from the Government of Tanzania.
The study found that plot-specific fertilizer recommendations based on on-site soil tests, paired with subsidies to purchase fertilizer, can improve farm productivity and profits. Farmers who only received a subsidy but no fertilizer recommendations increased their use of fertilizer, but did not see improved maize yields, since the fertilizer they used did not address soil deficiencies. Farmers who received fertilizer recommendations but no subsidy used no fertilizer because they were unable to cover the cost. There was no increase in greenhouse gas emissions or leaching during the study, and the risk of any environmental damage going forward is extremely low, according to the researchers.
"The joint effects of information and financing constraints on technology adoption: Evidence from a field experiment in rural Tanzania" by Aurélie P. Harou et al in the Journal of Development Economics.
New type of earthquakes discovered
A research team from Canada and Germany have discovered a new type of injection-induced earthquakes. Unlike conventional earthquakes of the same magnitude, they are slower and last longer. These seismic events are triggered by hydraulic fracturing, a method used in western Canada for oil and gas extraction. The team of researchers - including Yajing Liu, an Associate Professor in the Department of Earth and Planetary Sciences - recorded seismic data of nearly 350 earthquakes and found that around ten percent of the seismic events turned out to exhibit unique features suggesting that they rupture more slowly, similar to what has been mainly observed in volcanic areas. Their existence supports a scientific theory on the origins of injection-induced earthquakes that until now had not been sufficiently substantiated by measurements.
"Fluid-injection-induced earthquakes characterized by hybrid-frequency waveforms manifest the transition from aseismic to seismic slip" was published in Nature Communications.
Uncovering the chemistry of bleach
Chlorine bleach has been used for almost 250 years since Claude-Louis Berthollet first discovered it in the 1780s. But until now, no one has ever described the structure of the active chemical component of liquid bleach - known to chemists as sodium hypochlorite. Research from McGill has now elucidated the structure of sodium hypochlorite, a very simple and a very unstable compound (making it difficult to isolate). This compound is also a member of the broader family of hypohalites, simple but also highly reactive compounds that are of fundamental importance in chemistry, and which have a dedicated spot in every textbook of general or inorganic chemistry. The recent paper, which is the first to provide a structural characterization of a hypochlorite and a hypobromite (also a well-known pool sanitizer) salt, fills an outstanding gap in structural chemistry.
"After 200 years: the structure of bleach and characterization of hypohalite ions by single-crystal X-ray diffraction" was published in Angewandte Chimie.
Society
How stereotypes influence first impressions | Perfectionists did not adapt as well to the pandemic | Misinformation, conspiracies, and the Canadian election | How to break up with your phone
How to break up with your phone
Do you spend more time on your smartphone than you would like and have trouble cutting back your screen time? You are not alone. McGill University researchers may have found a solution based on nudges, small changes to phone settings or behaviour that can help curb smartphone addiction. The intervention includes various components such as changing the phone display to greyscale and keeping the phone out of the bedroom when sleeping. The researchers found that participants following the intervention reduced their screen time, reported feeling less addicted to their phones, and had better sleep quality.
"Most of the participants spent four to five hours per day on their phones. The intervention reduced this by about an hour per day, sometimes freeing up the equivalent of an entire full-time work week per month," said Jay Olson, a postdoctoral scholar at McGill University who led the study.
"Smartphones and social media have become an integral part of daily life, but many people still struggle to use them in a way they consider healthy," said Samuel Veissière, McGill professor of Psychiatry who supervised the research. "Our intervention offers a small part of the solution."
The team recently launched the website Healthy Screens for the public to assess their smartphone addiction by completing a short questionnaire. The site also shows the intervention strategies used to reduce smartphone use..
A nudge-based intervention to reduce problematic smartphone use: Randomised controlled trial by Olson, J. A., Sandra, D. A., Chmoulevitch, D., Raz, A., & Veissière S. P. L. was published in International Journal of Mental Health and Addiction.
Misinformation, conspiracies, and the Canadian election
Misinformation was rampant during the past federal election, spread in part by well-organized and growing conspiracy-minded communities, according to a new report by researcher from McGill University's Max Bell School of Public Policy. While the results of the election were only minimally influenced by the misinformation, there are reasons to worry, warn the researchers.
The team, led by Professor Taylor Owen and Media Ecosystem Observatory Director Aengus Bridgman, analyzed information flows across social and broadcast media along with data collected from a national survey on attitudes, perceptions, and exposure to misinformation. The researchers found that claims of widespread voter fraud circulated on social media platforms among certain communities. They also found that COVID-19 misinformation played an important role in the election campaign. Protesters opposing pandemic health measures and vaccination policies - in many cases fuelled by misinformation - hounded several candidates and were able to push COVID-19 related concerns to the top of the campaign agenda.
What the researchers found most troubling were indications of the emergence of a digitally literate misinforming community that is deeply distrustful of governments, experts, and large media outlets in Canada. "The threat to democracy may lie more in the slow and steady erosion of factual agreement, institutional trust, and social cohesion than in a flurry of election activity," says Aengus Bridgman. "Governments, media, social media companies, and the public each have a role to play to limit the pernicious impacts of misinformation during and beyond elections." In their report, the researchers provide recommendations to address these challenges and build Canada's resilience to misinformation.
"Mis- and disinformation during the 2021 Canadian federal election" was published by the Media Ecosystem Observatory, a research initiative of the McGill University Max Bell School of Public Policy and the University of Toronto Munk School of Global Affairs and Public Policy.
Perfectionists did not adapt as well to the pandemic
The pandemic affected people in different ways, with some using it as an opportunity to find new experiences to help them cope, while others dwelled on what could have been, if only things had gone according to plan.
Students with higher levels of self-critical perfectionism experienced more depression and were more likely to focus on missed experiences during the pandemic than gained ones, a new study led by McGill Psychology PhD Candidate Shelby Levine has found. Perfectionists did not adapt as well, researchers say, because they were fixated on how things did not go according to their plan, and because they were not as effective at coping or finding experiences to help them feel more autonomous, competent, and connected with others during this difficult time. The study shows why perfectionism is a vulnerability factor for depression, because individuals higher in perfectionism were less able to adapt, and change their mindset.
The study is one of the first to examine lost events in the context of the pandemic, a time when many unexpectedly missed out on important life events. Interestingly, it also found that most people were able to find gained experiences - such as spending time with family or engaging in self-care - during the pandemic to cope with the loss of autonomy, competence, and relatedness during this stressful time. "Trying to contrast losses and gains could help to identify what a person has taken from a difficult experience, or further how to increase their autonomy, competence and relatedness when going through a difficult time," said Levine, who was inspired to pursue this research after having to postpone her wedding three times due to the COVID-19 pandemic. The study also shows how thinking in a very "black and white" manner can be detrimental in perfectionists. "Many university students are perfectionists, and this paper identifies how this can be harmful," Levine said.
"A not so perfect plan: An examination of the differential influence of multidimensional perfectionism on missed and gained events during the COVID-19 pandemic" by Shelby Levine et al. was published in Personality and Individual Differences.
How stereotypes influence first impressions
Snap judgments based on appearances can have far reaching consequences, from election results to sentencing decisions in the criminal-justice system. People are quick to use facial characteristics to form judgments about others, like whether a stranger is trustworthy or competent. The prevailing view is that first impressions are sparked by physical features of the face - like an upturned mouth, or downturned eyebrows - and that this process is the same for everyone. However, new research finds that people form impressions differently depending on the target's race and gender. In the study led by PhD Candidate Sally Xie, working with Professors Eric Hehman and Jessica Flake of the Department of Psychology, participants were asked to rate White, Black, and East Asian faces on 14 traits, including competence, trustworthiness, warmth, and strength. Their research shows that our own learned stereotypes about each group influence the way we form impressions of people. In other words, individuals have expectations about members of social categories and use this information as a template when forming impressions. The study is the first to formally test the role of stereotypes in structuring people's first impressions of faces.
"Facial Impressions Are Predicted by the Structure of Group Stereotypes" by Sally Y. Xie et al. was published in Psychological Science.
Technology
Self-assembly as easy as playing music | Cheaper batteries for electric vehicles? | Smartphone addiction on the rise | Dining in space: crickets with a side order of microalgae | Can mobile phones help promote gender equality in politics? | Using mobile phones to curb domestic violence
Using mobile phones to curb domestic violence
Are women who own mobile phones safer from domestic violence? Luca Maria Pesando, an Assistant Professor in the Department of Sociology, set out to answer this question by analyzing data from 10 low- and middle-income countries. In seven of the 10 countries, he found that women who owned a mobile phone were nine to 12 per cent less likely to experience emotional, physical, and sexual violence over the last 12 months - even after accounting for socioeconomic factors and local development within communities.
"Overall, the findings are consistent with the idea of mobile phones serving as empowering devices for women, with biggest payoffs among the poorest countries and communities. Mobile phones can also serve a protective role for women by boosting communication, providing access to information, and expanding community outreach," says Professor Pesando.
While the data was collected prior to the pandemic, the findings from this study have important implications for household dynamics in the COVID-19 era. "During a pandemic that imposes lockdowns, women and their abusers are bound to share the same space for long periods of time, increasing women's risk of experiencing domestic violence. Mobiles phones may also help women overcome physical boundaries, especially those who are separated from support networks," says Professor Pesando. His research builds on the increasing evidence that mobile phones may serve as tools for attaining the United Nations Sustainable Development Goals by narrowing gender inequalities.
"Safer If Connected? Mobile Technology and Intimate Partner Violence" by Luca Maria Pesando was published in Demography.
Self-assembly as easy as playing music
The rise of robotics in manufacturing revolutionized the way goods were produced around the world through automation. But more versatile and sustainable solutions are on the horizon. Researchers from McGill University have pioneered a self-assembly technique driven by music vibrations. This technique could one day be used to produce a variety of materials for biomedical, aerospace, and other purposes. Applying principles of mechanics and physics, the team led by Aram Bahmani of the Department of Mechanical Engineering and Francois Barthelat from the University of Colorado Boulder, used vibrations in their experiments to successfully organize small building blocks into a pre-designed structure. Their findings pave the way for new methods to quickly assemble, disassemble, and repair more complex materials and structures, including within the human body. One potential medical application the researchers are exploring is to the blood clotting process, to stop the bleeding quickly after an injury. They are also looking to apply it to the healing process in bones.
"Vibration-driven fabrication of dense architectured panels" by Aram Bahmani et al. was published in Matter.
Cheaper batteries for electric vehicles?
Developing inexpensive, higher-energy, and sustainable rechargeable lithium-ion batteries (LIB) is a crucial part of making electric vehicles and renewable energy more widely accessible. A McGill research team, led by Prof. Jinhyuk Lee in the Department of Mining and Materials Engineering, has provided the first in-depth analysis of a promising new class of low cost, high-capacity LIB cathodes made of inexpensive and abundant Manganese-based disordered rock salt materials. Their research reveals four areas where improvements are critical to enabling the development and commercialization of cost-effective, energy-dense, and ultra-high-performing next-generation LIBs: minimizing the electrode porosity, maximizing the active material content, enhancing the electronic conductivity, and avoiding a pulverized-particle morphology. This research has the potential to increase the energy density and cost-effectiveness of LIBs to the point where electric vehicles (EV) could become highly economical. Indeed, because the work is so promising, Prof. Lee has been awarded several grants by the National Sciences and Engineering Research Council of Canada (NSERC) and is in the final stages of obtaining a major grant from an EV battery manufacturer, which will be officially announced shortly.
"Toward high-energy Mn-based disordered-rocksalt Li-ion cathodes" by H. Li & R. Fong et al. was published in Joule.
Smartphone addiction on the rise
The link between smartphones and mental health remains unclear, but data from nearly 34,000 participants in 24 countries suggests that smartphone addiction around the world increased significantly between 2014 and 2020 according to McGill researchers. China and Saudi Arabia had the highest rates of smartphone addiction, while Germany and France had the lowest rates. Canada (based on a sample taken at McGill University) was also quite high. The researchers suspect that a possible explanation for the differing national levels of smartphone addiction may be varying social norms and cultural expectations about the importance of staying in contact regularly through smartphones. They reached these conclusions about increasing smartphone addiction by looking at 81 studies of adolescents and young adults around the world which used the Smartphone Addiction Scale (SAS), the most widely used measure of smartphone addiction, to ask about smartphone use in relation to daily-life disturbances, loss of control, and withdrawal symptoms. The team also recently launched a website for the public to assess their own smartphone addiction compared to others around the world. The site also offers recommendations for people looking to reduce their screen time.
"Smartphone addiction is increasing across the world: A meta-analysis of 24 countries" by Jay Olson et al. was published in Computers in Human Behavior.
Dining in space: crickets with a side order of microalgae
Deep space travel may soon be within reach, but what will astronauts eat on missions that last for years, taking them far from Earth? Two student-led teams from McGill University were selected as semifinalists of the Deep Space Food Challenge, a joint initiative of NASA, the Canadian Space Agency (CSA), and Impact Canada.
Among the projects, is a first-of-its-kind technology to breed and harvest crickets suitable for human consumption. Starting with nothing but a few hundred eggs, the team anticipates that the Cricket Rearing, Collection, and Transformation System will quickly support the growth of tens of thousands of crickets every month. The technology produces a finely-ground powder that is stored safely within the system itself. When combined with water to form a paste, cricket powder is a versatile ingredient, packed with protein.
The second project, the InSpira Photobioreactor, is a highly automated system to grow, harvest, and package spirulina drink products. This type of blue-green algae packs a nutritional punch and is commonly available as a dietary supplement at health food stores. The proposed technology is a unique, cartridge-based photobioreactor, coupled with an in-house harvesting, dewatering, and processing unit to transform the culture into edible forms.
The teams will be building prototypes of their proposed solutions for deep space food production soon.
