This month in science @ McGill

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Seashells inspire shatterproof glass:

The intricate patterns of waves on the surface of seashells serve more than a decorative purpose. These tiny cracks are actually the secret behind the incredible strength of the shell.

Thanks to a technique developed by Francois Barthelat­—a professor in the Department of Mechanical Engineering at McGill—and his team, the researchers modeled a type of glass similar to the structure of seashell and is 200 times more durable than normal.

The team derived its concept from nature. By looking at the mechanism of natural structures, such as seashells, the researchers came up with hypotheses to significantly increase the toughness of glass.

“Narcre, or mother-of-pearl, which coats the inner shells, is made up of microscopic tablets that are a bit like miniature LEGO building blocks, [and] is known to be extremely tough and strong, which is why people have been studying its structure for the past 20 years,” Barthelat said in an interview with the university.

The team studied the ‘weak’ edges found in natural, flexible materials, such as narcre. The researchers then used lasers to engrave three-dimensional networks of micro-cracks into the glass slides.

“What we know now is that we can toughen glass, or other materials, by using patterns of micro-cracks to guide larger cracks, and in the process, absorb the energy from an impact,” Barthelat said.

In the future, his team hopes to scale up this technique to any size of glass sheet, working towards the production of shatterproof glassware.

Nutritional costs of food-secure future:

Purchasing products of large-scale agriculture may save you a couple dollars; however, Timothy Johns, professor of Human Nutrition at McGill University in Montreal, cautions that these products have a cost in terms of nutritional health.

In his presentation at the annual meeting of the American Association for the Advance of Science in Chicago, Johns demonstrated how diets are becoming increasingly limited in biological and nutritional diversity as a result of large-scale farming.

“Products of biodiversity within culturally-based diets provide essential micronutrients and lower prevalence of diet-related chronic disease,” Johns said to the McGill Reporter. He is worried about the health consequences of single-crop farming, since it lacks the agrobiodiversity of smaller farms.

While large-scale farming efforts are directed towards feeding the globe’s increasing population, Johns explained how carbohydrates produced by such efforts, like cereal, sugars, and potatoes often result in malnutrition due to overconsumption of calories—a contributing factor to obesity and chronic diseases like diabetes and cardiovascular disorders.

Johns proposes that food-policy decisions should be directed towards supporting smaller scale agriculture. Brazil’s National School Feeding Law and Program is one example of such an approach. Since 2009, the law has required at least 30 per cent of food in the program come from family agriculture. By embracing smaller scale agriculture, this program is working towards better nutrition for the overall community.

Training  your brain:

Looking at a display screen, participants changed a coloured disk from dark red to bright yellow or white all by simply manipulating their own brain activity thanks to a non-invasive imaging technology magnetoencephalography (MEG).

The study, which was recently published in the journal NeuroImage, strongly suggests MEG can be used as a therapeutic tool to control and train targeted brain regions. While patients of epilepsy show the most promise, scientists suspect it could also be used to treat stroke, dementia, and chronic depression, among other neurological disorders.

MEG is a technology that measures magnetic fields generated by neuronal activity in the brain. These measurements allow scientists to localize the sources of activity and record these images. This helps people view their brain activity in real time—a millisecond time scale across the entire organ—and allows them to control and adjust a function of their brain in pre-determined regions.

MEG’s therapeutic advantages include its potential to reveal the dynamics of brain activity involved in perception, cognition, and behaviour. It could also provide unique insight on neural dysfunction, such as movement disorders and chronic pain.

Sharing is caring—even when it comes to diabetes:

Unlike the flu, you can’t catch diabetes from someone coughing next to you. However, a research team from the McGill University Health Centre (MUHC) has shown through combined analyses of several studies that you may be more susceptible to developing diabetes from living with someone with the disorder.

The findings were published in the journal BMC Medicine this February and were based on six selected studies conducted in different parts of the world. According to the McGill Reporter, the studies assessed outcomes such as age, socioeconomic status, and the way in which diabetes was diagnosed in a total of 75,498 couples.

“We found a 26 per cent increase in the risk of developing type II diabetes if your spouse also has type II diabetes,” Kaberi Dasgupta, senior author of the study and researcher at the Research Institute of the MUHC told the McGill Reporter.

One reason for this increase is that many of the risky behaviours that lead to diabetes are often shared within the household. These include poor eating habits and low physical activity.

Future studies will hopefully indicate how closely interwined the relationship is between living with someone with diabetes and developing the disorder yourself.