Here are some interesting new stories from McGill University Media Relations:
Science
Improved maize yields in Tanzania
Improved maize yields in TanzaniaGiven 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
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
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.
Read more from “Deep Space Dine” by Research and Innovation (R+I) at McGill University.
Can mobile phones help promote gender equality in politics?
Do people who use mobile phones hold more positive views towards gender equality in politics? A team of international researchers including Luca Maria Pesando, an Assistant Professor in the Department of Sociology, set out to investigate this question in 36 African countries. They found that regular use of mobile phones is associated with more positive attitudes towards women’s participation in politics; however, this was only observed among women and not men. The results strengthen the idea that technology adoption on the part of women – by improving connectivity, expanding access to information, and broadening one’s own physical and remote network – may be a promising lever to promote gender equality and societal well-being, and to address some of the United Nation’s Sustainable Development Goals. The researchers also point out an important yet often neglected issue: policies aimed at changing gender attitudes are often targeted at women, but men’s attitudes can be harder to shift than women’s, requiring different approaches.
“Mobile Phones and Attitudes toward Women’s Participation in Politics: Evidence from Africa” was published in Sociology of Development.
