Category Archives: Science communication

Is Obesity Caused By Pollutants Around Us?

If you are trying earnestly to maintain your weight, you may have the phrase “watch what you eat” in mind.  Junk food and sweets are out, but the question you forgot to ask is: should you be wary of other foods on your plate as well? The answer is yes.  

Studies have revealed that Persistent Organic Pollutants (POPs) play an indirect role in adding fat mass to the body.  People are affected by the environment because all our needs ultimately come from the surroundings and these very pollutants are able to enter your diet to alter the endocrine system, organ function, tissues, as well as fat cells.

Where Persistent Organic Pollutants (POPs) Come From

Predominantly used as pesticides, Persistent Organic Pollutants (POPs) are now under restricted usageThese chemicals were created for industrial processes and were also released as by-products. 

Smog filled with pollutants created from factories easily reach neighbouring crop fields.
Source: Gustavo Madico, Flickr

Once exposed to the environment, POPs travel far and wide, made possible by its resistance to most chemical and biological processes in normal degradation.  Naturally, animals consume available POPs, leading to its bioaccumulation  in tissues.  The problem is then amplified with biomagnification in food webs, and humans are, of course, at the top of the food chain.

This video by Sustainable Consumption and Production Regional Activity Centre summarizes the impact of POPs:

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The Link to Obesity

Since POPs accumulate in fatty tissues of animals, we consume them when our meal includes fatty fish, meat, and dairy products.

Fatty fish are victims of POP bioaccumulation.
Source: Ivan Walsh, Flickr

An increasing number of studies are finding a strong link between POPs and body weight.  POPs have been shown to affect key endocrine pathways in the human fatty tissue and there is a strong correlation between the expression of obesity marker genes (determinants of obesity) and POP concentrations.  In another study, a group of mice tested with a high-fat diet containing high POP levels gained more visceral body fat then the group of mice with a low-fat diet.   This indicated that metabolic processes were altered, leading to obesity and insulin resistance, which can progress to Type 2 Diabetes.  In fact, diabetes poses a possibly even more harmful health problem than obesity itself!

Possible Solutions

Despite the fact that POPs are highly regulated to limit its toxic effects, they can still be found in many environments because of the movement within food chains.  Does this mean you should lose all faith in the foods you eat? Hopefully not! As further research gives more evidence to support the causal role of POPs, awareness will increase and perhaps POPs will no longer be put in use.

It may be helpful to eat food grown with fewer pesticides, but a normal, balanced diet without excessive amounts of fatty fish and meat should be fine.

Post by Madeleine Tsoi

The Black-Tailed Antechinus: The Definition of Fatal Attraction

You may think a teenage boy is sex crazed, but this marsupial takes it to a whole other level. Scientists have recently discovered a new species, whose sexual preferences rival those of even the horniest of teenagers.

Agile Antechinus. Courtesy of: Wikimedia Commons (user: Richard001)

Map of Australia. Courtesy of: Wikimedia Commons (User: Martyman)

Meet the Black-Tailed Antechinus, a carnivorous marsupial found in the humid and forested region of southeastern Queensland and northeastern New South Wales, Australia. Although it is an extremely rare and exciting event to discover a new species of mammal, this particular creature piqued the interest of researchers further due the male’s “sex marathons” that ultimately result in their death.

The species, Antechinus arktos, commonly called the Black-Tailed Antechinus, was first discovered in May 2013 by a team of scientists out of Queensland University of Technology. The team, led by mammologist Andrew Baker, published their discovery in the journal Zootaxa.

The Black-Tailed Antechinus is slightly larger than a mouse and looks very similar to the Agile Antechinus (Antechinus agilis), being distinguishable by its larger skull, as well as its black feet and tail. Male Black-Tailed Antechinuses are semelparous, meaning they reproduce only once in their lives.

Agile Antechinus. Courtesy of: Wikimedia Commons (User: Richard001)

In August, at only 9 months of age the males reach sexual maturity. Once sexual maturity is achieved, sex becomes all these creatures think about. Does this sound familiar? Well, unlike teenage boys, the sexually mature, male, Black-Tailed Antechinuses cease to participate in anything unrelated to finding sexual partners. When a female is found, they engage in unrelenting sex lasting up to 14 hours. The males then move on to find mate after mate for approximately 2 weeks. Andrew Baker describes it as,

“frenetic, there’s no courtship; the males will just grab the females and both will mate promiscuously,”

Unfortunately, during this 2 week orgy the males rid themselves of vital proteins and suppress their immune system. In addition, an overload of stress hormones further damage the body, ultimately resulting in infection and likely death.

“Their fur falls off. The look very sick and stagger around and sometimes they get gangrene infections because their immune system stops working.”

This is how Dr. Diana Fisher of the University of Queensland describes the males unpleasant end. 

Female Agile Antechinus with Joeys. Courtesy of: Wikimedia Commons (User: Richard001)

It is not much better for the females unfortunately, who have to carry up to 14 joeys in their pouch. The female Black-Tailed Antechinuses store the sperm of every male they mate with and only ovulate at the end of the breeding season. This results in a large litter of joeys being born, who are likely from a wide variety of Fathers. Very few females survive raising even one litter. 

Although one may be able to say that they died doing what they loved, the phrase “Fatal Attraction” has never had a more literal meaning.

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Monica Leslie

A Grip on Reality: The Future of Prosthetics

The human body has five basic senses: sight, sound, taste, smell and touch. Now take a minute and imagine your life without one of them. It’s easy to realize that we as humans rely on our senses for almost everything we do. Yet there are many people in the world, such as amputees, that do not have one or multiple senses.

Dennis Aabo Sørensen, a man from Denmark, became an amputee almost nine years ago when he lost his left hand in an accident. Although he was using a prosthetic hand, he had permanently lost the ability to feel anything from his hand. That is until recently when he became the first human to try the new bionic hand that allows you to feel what you touch with a prosthetic.

Image from Google Images

The scientists at Swiss Federal Institute of Technology in Lausanne (EPFL) and the Sant’Anna School of Advanced Studies of Pisa (SSSA) designed the bionic hand prototype that will allow people like Dennis to feel objects in real-time using sensory feedback technology. The bionic hand works by measuring the force it takes for the tendons in the artificial hand to grasp an object. Once the measurement of force is identified, the tendons send electrical impulses through wires to the electrodes that have been surgically connected to the nerves of the actual arm. Although it seems like the impulse is not instantly sent to the brain, it actually happens in a matter of seconds to give the feeling of real-time. In the following video Silvestro Micera provides a more in-depth preview of the bionic hand and Dennis Aabo Sørensen describes his initial thoughts on this new technology.

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Although this technology is still years away from being commercially available, it is still a great achievement in the medical world. I believe the next steps in this project would be to figure out how to make this technology available in portable prosthetics and how much it would cost for the general public. Having said that, this technology holds great promises for people like Dennis who have been unable to experience their life fully due to their lost sense. Many individuals can now look forward to a brighter future in the world of prosthetics.

Vishav Gill


Electricity at the palm of your hands

Have you ever considered that your hands could be a source to produce electricity? With materials called Peltier tiles, you can actually create products that are powered by the energy from your hand. Peltier tiles rely on the thermoelectric effect. When one side of a material is hotter than the other, the temperature difference can be used to generate a voltage. With a temperature gradient produced, charge flows from the hot to the cold side.

The Peltier effect. Source: Wikimedia commons

Remarkably, Ann Makosinski from Victoria was able to use Peltier tiles to create a hand powered flashlight. In her design, she used a hollow aluminum tube and embedded Peltier tiles into the material as the base of her flashlight. She created a temperature difference by heating the outside of the material with the palm of her hand and cool the inside of the tube with an internal air system. Her flashlight was able to turn on in the absence of light just by placing her hand over the flashlight.

A flashlight courtesy of Mrmariokartguy from Wikimedia Commons

The importance of this technology is significant. We don’t always have a set of batteries lying around and in the event of an emergency, a hand powered flashlight would be extremely useful. Here is a video from Ann Makowsinski describing her flashlight:

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Video courtesy from the user: Queenie Andini

Pacemakers are now using this technology.  A chip is inserted into the body that requires a 2 degree difference in temperature difference to run. Dinesh Bhatia and her colleagues from the Journal of Pharmacy and Bioallied Sciences have found that areas just under the skin can cause a temperature difference by 5 degrees Celsius. With the use of the thermoelectric effect, we won’t have to perform surgeries just to replace the batteries of a pacemaker.

The problem with this technology is that it may not be able to generate a lot of electricity. If we could find a way to overcome this, it would be a revolutionary change to the products we can produce.

Science behind the Morning Wood

It happens to grown men, little boys, and even male still in utero: the ability to pitch a tent in the morning in your pyjamas without any camping skills.

All jokes aside, nocturnal penile tumescence, otherwise known as morning wood, is a phenomenon that males experience on a daily basis without a full understanding of how and why it happens.

An experience we men are too familiar with

It is revealed by studies that morning wood occurs numerously during sleep, and is in direct correlation with the sleep cycle that alternates between levels of sleep.

One of the most important stages of sleep is the Rapid Eye Movement (REM) stage. An average male undergoes REM stage around 4-8 times over regular sleep, and at this stage of sleep certain neurotransmitters decrease.

Of the many neurotransmitters that decrease during REM sleep, Norepinephrine is one of them.

Norepinephrine structure

Norepinephrine acts as a vasoconstrictor that regulates erections. Metaphorically, it is used as a stop sign chemical that inhibits blood flow into penis muscles and thus inhibiting the erection.

In REM sleep, it is proved that norepinephrine levels drastically drop and allow vasodilation, increasing the blood flow into the penile muscles.

So why is morning wood important?

To answer the question, increased blood flow into the penis muscles, like any other tissue in the body, increases oxygenation. This increased blood flow and oxygenation is critical in repairing and maintaining functionality.

Another question one might bring up is why we always wake up to this phenomena. The answer is because we most usually wake up just out of REM sleep and thus observe the remnants of this sleep stage.

It is profound how such phenomena we face everyday without much thought can be the result of chemical reactions in the male body. Perhaps next time you wake up with morning wood you’ll be assured that you’re fully repaired and fully functional.




The Memory Game: Does Caffeine Help?

It is the night before that dreaded exam; the question surely revolving within your head is whether or not to chug down a cup of coffee.  If the goal is not to merely stay awake and finish reading those last few chapters but to keep your optimal level of memory up, then the following information is your key to success.

A variety of beverages contain caffeine, such as energy drinks.
Source: Daniel Jurena, Flickr

The Bad:

Caffeine has a half-life of approximately 6 hours which implies after a full 12 hour day, 25% of the original caffeine dose will still be present in your bloodstream.  Depending on dose, varying levels of sleep disruption or insomnia may follow.  In addition to not being able to sleep (which certainly will not aid your memory), the side of the coin people often overlook about caffeine is after its intake, as research has shown, the REM (Rapid Eye-Movement) phase and slow-wave deep sleep are affected.  REM sleep is believed to be the stage of the regular sleep cycle when memory is consolidated, thus it is critical that it remains undisturbed.

The Good:

Fortunately for coffee drinkers, there is new light shed on the beneficial effects of caffeine. Recently, a study conducted by undergraduate student Daniel Borota and a research team at John Hopkins University marked the first time direct results of caffeine stimulating the improvement of memory were recorded.  In the study, participants observed a series of simple everyday images including an office chair, a duck, and a saxophone.  To control for variances of individuals’ conditions, all participants viewed the images first, before half of the group was given a 200mg dose of caffeine while the other half was subject to a placebo.  The next day, the participants viewed another series of similar images and the group with caffeine intake the previous day was found to identify slight image differences with greater accuracy than the placebo group.  This differentiation is called pattern separation in neuroscience and leads to the conclusion that caffeine does indeed enhance memory consolidation in humans.

Dr. Michael Yassa from John Hopkins University further explains the study:

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There is a fine line between over-caffeinating yourself to cram for exams and taking a healthy dose of it to help with alertness.  This new research shows that perhaps, the recommended amount of caffeine to optimize memory may be 200mg- just about one strong cup of coffee.

Blog post by Madeleine Tsoi