Author Archives: Peggy Hung

Sniffing out Parkinson’s

Even if you have not been personally affected by Parkinson’s, this terrible disease affects all Canadians. Parkinson’s is the second most common neurodegenerative disease (after Alzheimer’s disease), affecting voluntary movement and leading to common symptoms of tremor, slowed movements, and muscle rigidity. Nearly 100,000 Canadians have Parkinson’s and no cure. The economic burden of Parkinson’s in Canada is huge. The total cost of Parkinson’s is estimated to be $558.1 million, equating to an average cost per capita in Canada for the disease to be $23/year.

The onset of Parkinson’s may not be apparent at first, leading to a lengthy diagnosis, relying on the process developed by Dr. James Parkinson in 1817. Diagnosis depends on a complete neurological examination to confirm two out of the three common symptoms and to rule out any similar disorders. No tests, blood or diagnostic, exist to definitively confirm the disease. However, one woman has recently astounded researchers by her ability to detect the disease with shocking accuracy – through her sense of smell.

Joy Milne with her late husband. Credit: CBC News

Joy Milne with her late husband.
Credit: CBC News

Joy Milne of Perth, Scotland, noticed her husband’s scent changed six years before he was diagnosed with Parkinson’s. She describes it as a distinct, musky smell, but didn’t make the connection between the smell and the disease until she joined a charity for Parkinson’s and encountered other Parkinson’s patients emitting the same distinct smell. Intrigued, researchers at Edinburgh University tested her claim by subjecting her to a blind “smell” test. Researchers gathered six healthy people and six who were diagnosed with Parkinson’s and asked them to wear a t-shirt for a day, and collected the t-shirts for Joy to smell. Joy’s accuracy was remarkable, scoring 11 out of 12. However, she was adamant that one of the healthy subjects had Parkinson’s. Eight months later, she was proved correct – the subject informed researchers that he had been diagnosed with Parkinson’s, meaning Joy’s accuracy was actually 100%.

Scientists are thrilled by this phenomenon, and are trying to use Joy’s ability to develop a definitive test for diagnosing Parkinson’s. They believe that the disease causes a change in the skin of Parkinson’s patients early on, causing the distinct odour detected by Joy. A simple test, such as swabbing a subject’s skin to detect the change, would allow for much faster diagnosis and much earlier treatment. While this discovery may have been accidental, it definitely has many implications and consequences in the way this disease is treated.

– Peggy Hung

Science in the Kitchen

We are accustomed to thinking that science is conducted in a lab, but science is everywhere – even in your own home. Cooking is often viewed as a household skill, but it is actually a science, specifically, the science of ingredients and processes that change their tastes and forms to create a delicious product.

Eggs are a simple ingredient, and I’m sure many of us have experience cooking with it. Scrambled eggs, meringues, and Hollandaise sauce are all based on the humble egg, and yet yield such different results. How? It is all down to the science of the cooking methods!

Credit: Daniel Novta, Flickr

Credit: Daniel Novta, Flickr

Heat

Uncooked egg is composed of a clear, runny egg white and thick, yellow egg yolk. Egg whites are primarily water and protein, while yolks contain a higher percentage of proteins and considerably more lipids. Recall that proteins are composed of chains of amino acids. While the bonds linking individual amino acids are strong covalent bonds, the bonds holding the chains in its 3-dimensional structure are weaker hydrogen bonds. When the egg is heated, the heat denatures the proteins by breaking the weaker hydrogen bonds. This causes the proteins to unravel from their native configuration, leaving chains of unfolded protein. When these chains encounter one other, hydrogen bonds form between them at random, resulting in a network of interconnected proteins, which hardens the egg. Light can no longer penetrate through this mass of protein, and the egg white turns from clear to white. When the egg is heated for too long, the egg hardens too much and gives off a “rubbery” texture.

Sunny side up! Credit: truds09, Flickr

Sunny side up!
Credit: truds09, Flickr

On a tangent: scientists recently devised a way to “un-scramble” an egg while investigating cancer research techniques. When cancer-associated proteins are produced in a lab, they often come out as a jumbled protein network akin to heated egg whites. This method of reversing denatured proteins may make cancer research more time and cost efficient.

"Un-scrambling" an egg Credit: Draw Science

“Un-scrambling” an egg
Credit: Draw Science

Beating

Meringues, soufflés, and tiramisu – all these light and fluffy textures come from beating egg whites. Beating egg whites adds air into the mixture, but the physical action also denatures the proteins, exposing hydrophobic and hydrophilic areas. As with heating, the denatured proteins cross-link to form a protein network, but with hydrophobic areas facing towards the air bubbles and hydrophilic areas facing away. The air bubbles are “locked” and incorporated into the network.

Whisked egg whites Credit: Wilson Hui, Flickr

Whisked egg whites
Credit: Wilson Hui, Flickr

This does not work with yolks however, which contain lipids. The lipids interfere with the formation of the protein network, competing against proteins for a space to bind to. Recipes that call for egg foams will warn for careful separation of whites and yolks.

Chemical process of egg foam Credit: A Dash of Science

Chemical process of egg foam
Credit: A Dash of Science

Emulsifier

Hollandaise sauce, a mixture of emulsified egg yolk and butter Credit: cyclonebill, Flickr

Hollandaise sauce, a mixture of emulsified egg yolk and butter
Credit: cyclonebill, Flickr

Egg yolks have their own use as an emulsifier, combining oil and water mixtures that would otherwise separate. The hydrophobic/hydrophilic nature of amino acids in many yolk proteins (e.g. lecithin) attract water in some areas and oil in others, creating a thorough mixture of the two substances within the protein chains. Beating the mixture with a whisk further helps incorporate the liquids. This allows us to enjoy delicious creamy mayonnaise and Hollandaise sauces without them separating first!

Food for thought next time you’re pondering the scientific reasoning behind the steps in your recipe book!

– Peggy Hung

The Quest for the Perfect Fuel

Recently, the Volkswagen scandal has taken the media by storm. What is it all about? The Environmental Protection Agency (EPA) of America discovered software dubbed “defeat devices” installed onto VW diesel engines, which sensed when the car was being tested for emissions, and would change the car’s performance to improve results. When being driven normally, the devices would switch back to “road” mode. This deception allowed VW to bypass strict emission regulations, selling cars with emissions up to 40 times more than allowed in the US. VW has now admitted to the use of these devices, which affect 11 million cars worldwide.

Former Volkswagen Group of America CEO Martin Winterkorn admitting to the use of defeat devices
Credit: BBC News YouTube

The effects of this mistrust have reached an international scale. VW has discredited itself from its customers, and now faces investigations from multiple countries. The European Union (EU) has come into fire for its lax testing regulations that allowed such devices to go unnoticed for so long, and carmakers felt their market prices plummet in the days after the news broke. But one question rises above all: what is the future of diesel?

Carmakers have long marketed diesel as the more fuel efficient alternative to gasoline, but historically, diesel always lost in favour to gasoline. Diesel engines generally provided less power, the exhausts produced smelled awful, and the characteristic “knocking” sound all added to its list of inconveniences. Recently, stricter emissions regulations worldwide triggered carmakers to pour large investments into the advancement of diesel technology. Better refinery processes eliminated the smell from diesel exhaust, and better engineering improved both the knocking and power. But diesel emissions still contain carbon dioxide and, more worryingly, nitrogen oxides and dioxides, all of which are potent greenhouse gases.

As our world becomes increasingly aware of the roles cars and emissions play in global warming, we find ourselves on the quest for newer and greener technology. When Toyota introduced the Prius to the world market in 2003, it became an instant hit. Celebrities endorsed the new wonder car, waxing lyrical about the new hybrid technology, and the car was touted as the responsible choice for anybody with a green conscious.

A 2010-2011 Toyota Prius Credit: Wikipedia Commons

A 2010-2011 Toyota Prius
Credit: Wikipedia Commons

But one paradox of hybrids always stood out – if the point was to reduce car pollution, surely this would not only include the pollution done by the end consumer, but also by the carmaker during production. Toyota admits that building the Prius produces more carbon dioxide than a typical gasoline model. Its nickel battery is mined in China, where the material is cheapest due to widespread disregard of environmental regulations. Despite this argument, many carmakers continue to support the electric engine: Tesla maintains its stance on electric cars, BMW continues to invest in its electric i division, and even luxury sports carmakers are demonstrating new ways in which hybrid technology can be used.

Left: McLaren P1 Right: Ferrari LaFerrari Credit: qiuyang923 on Flickr

Left: the McLaren P1, which uses a hybrid system of gas engine in tandem with an electric engine
Right: the Ferrari LaFerrari, which also uses a hybrid system
Credit: qiuyang923 on Flickr

Perhaps we should look at an alternate way. Hydrogen fuel cells is hailed as the true solution to our never-ending need for fuel. Fuel cells cars can fuelled in a similar fashion to gasoline, so they do not face the range challenges of electric cars. They are more efficient than gasoline or diesel engines, and they produce absolutely zero emissions – the only product reaction is water.

The Toyota Mirai Hydrogen Fuel Cell concept car revealed for the first time at the 2013 Tokyo Motor Show. Credit: Wikipedia Commons

The Toyota Mirai Hydrogen Fuel Cell concept car revealed for the first time at the 2013 Tokyo Motor Show.
Credit: Wikipedia Commons

However, the technology still needs to be perfected. The Canadian Hydrogen and Fuel Cell Association (CHFCA) reports that Honda, Toyota, and Mercedes-Benz have hydrogen fuel cell concept cars that will be revealed to the public soon. Perhaps soon, we will be able to rely on truly emissions-free energy sources. Until then, we can only continue on strict government regulations and the keen observances of scientists and government agencies like the EPA to monitor our emissions.

– Peggy Hung