Tag Archives: Science

Don’t Forget Your Chocolate!

Memory loss has long since been correlated with age, due to a common deficiency of a certain protein in the dentate gyrus (region of the brain involved in memory) observed in elderly patients. Previously, this was just accepted as a hard truth; as you age, you’re destined to have to deal with various parts of your body slowly starting to become less functional, including your brain, which shrinks over time.


The dentate gyrus is a subregion of the hippocampus, shown in red. This part of the brain is involved in memory functions. Source: Wikimedia Commons

The dentate gyrus is a subregion of the hippocampus, shown in red. This part of the brain is involved in memory functions. Source: Wikimedia Commons

However, a recent study at the Columbia University Medical Centre has found that age-related memory loss, at least, is one thing that doesn’t necessarily have to impact you in your old age any longer.

Not only were the effects of age-related memory loss reduced in the study, they were actually reversed! How?

A group of otherwise healthy adults aged 50-69 were divided into two groups with different diets, which they followed for 3 months. The key difference was the level of flavanols (plant-based antioxidants) each group was consuming. The participants who followed a high-flavanol diet performed better on memory tests than those who followed a low-flavanol diet, and brain imaging showed that flavanols improved function in the dentate gyrus.

So what? Well, flavanols aren’t just a mysterious chemical reserved for scientific experiments…they are already readily available to us, and have been for a long time. Flavanols are found in tea leaves, blueberries, grapes and broccoli, so while it’s important that you do as you’ve been told and eat your fruits and veggies, flavanols are also found naturally in cocoa, which is present in chocolate.

Cocoa beans are used to make chocolate, and they are natural sources of flavanols. Source: Flickr Commons User Tom Hart

Cocoa beans are used to make chocolate, and they are natural sources of flavanols. Source: Flickr Commons User Tom Hart

A similar study in 2012 showed that drinking cocoa-containing beverages daily helped to indirectly improve blood flow in the brain, resulting in increased cognitive function, including improved memory.

However, this isn’t an excuse for everyone to just turn to a chocolate-only diet and claim that it’s in their best interests to eat as much of it as they can. Research shows that the cocoa-flavanol works best when paired with regular exercise, so it is important that a healthy lifestyle is maintained, while including flavanol-containing foods as part of a balanced diet.

That being said, chocolate can provide many other health benefits if eaten in moderation, as described in the video below.

YouTube Preview ImageVideo Source: YouTube user WLWT

So what are you waiting for? Go grab some tea, blueberries…what was the other thing? I can’t remember…


– Mikaela

Who said you can’t see bright stars in the deep ocean?


Euprymna scolopes by MattiasOrmestad

A photo of a Bobtail squid,  Euprymna scolopes, performing bioluminescence. It’s underside is brightly lit by its symbiotic bacteria V.fischeri. Photo by Mattias Ornestad on kahikai.org

Euprymna scolopes, commonly known as the Bobtail squids, are found around the Hawaiian Islands. Additionally, they’re about 4.5cm and has one other amazing fact: they have an indirect ability to perform bioluminescence, which is the production or emission of light by living organisms.  To be exact, the Bobtail squids don’t produce this phenomenon, it is the bacteria residing in these squids that produce this light. Together they can perform the largest symphony of dancing blue stars in the ocean.

The bacteria, Vibrio fischeri, is a symbiont that lives in the mantle of the Bobtail squids. The squids acquire this bacteria after they are hatched. These symbionts live in the deepest tract of the mantle and they produce the light source depending on the seawater environment, sensed through the squids’ pores. Furthermore, the Bobtail squids expel around 90-95% of these bacteria every dawn. At dusk, the bacteria increase in population and emit light again from the mantle. Since Euprymna scolopes is a nocturnal species, it hunts for prey at night time. With the bacteria, the squids are able to perform counterillumination. This effect allows them to camouflage themselves by looking like the sky above or deep abyss to divert their predators’ attention.

Here’s a video from the United Kingdom Society for Applied Microbiology uploaded by Siouxsie Wiles on YouTube. It explains how the Bobtail squids and the bacteria interact.

YouTube Preview Image


But here is the most astonishing hypothesis about the symbiotic relationship: the squids themselves can adjust the intensity of the light produced by their dependents.

Research tested this hypothesis and found two possible theories. Firstly, the squids may be controlling their oxygen intake to restrict the bacteria’s production of energy, thus resulting in dimmer or brighter illumination.  Secondly, the squids control light emission by using their ink sac as an iris to restrict light. Both processes cannot kill the bacteria but only limit its emission. Unfortunately, biologists couldn’t explain the mechanism behind light intensity control since they could not visually see inside the mantle.

Aliivibrio fischeri (toxita.cz)

A photo of the bacteria, Vibrio fischeri, which provides the Bobtail squid bioluminescence, in a petri dish. Photo from toxita.cz.

Biologists are trying to find out how these bacteria communicate with its host. There still remain many unanswered questions. For example, how do the squids know how much V. fischeri to expel? What happens if we remove these symbiotic bacteria from their hosts? How do the squids know when to stop before killing the bacteria?

With further research, they hope to understand how bacterial cells communicate with human cells using Bobtail squids as their model. Scientists wish to find ways to distinguish harmful bacteria versus those that help regulate our body. By understanding how V.fischeri functions inside the squids, we could produce antibiotics that only pinpoint the harmful bacteria in our body and find ways to disrupt these bacteria from causing us sicknesses.

– Alison Fung





Biomechanics and Human Mobility

The biomechanical operations of the human body can be largely attributed to the classes of lever systems composing the human musculoskeletal system. The human body is predominantly composed of first class lever systems and third class lever systems with high distance advantages. A first class lever system consists of an exertion of effort on one side of a fulcrum and an acting force on the other side of the fulcrum. A third class lever system consists of an exertion of effort close to a fulcrum and an acting force further from the same fulcrum. A Wikipedia image of lever classes with first class at the top (load and effort reversed from most human muscle systems) and third class at the bottom can be found here: http://en.wikipedia.org/wiki/Lever#mediaviewer/File:Lever_%28PSF%29.png

By applying a large amount of effort, humans are able to move limbs in relatively wide arcs with appreciable speed, but humans are not relatively well equipped to exert large amounts of force in comparison to other animals. In other words, humans are more capable of greater feats of mobility than they are of feats of great power and generally can’t carry much more than their own body weight. Muscles operate by contracting and pulling, not by pushing. The biceps, for instance, attach to the forearm near the elbow and pull to lift the load of the arm all the way out to the hand at the same angle corresponding to a larger arc around the elbow joint. If a human were to extend their arm and pushed on an object with the back of their hand, the triceps attached to the forearm would contract and pull the hand in the opposite direction around the elbow joint.

Further clarification of human muscle lever system biomechanics can be found here: YouTube Preview Image

– Jared Martin