Author Archives: Stephanie An An Lam

The Unique Features of Coral

Corals are eukaryotic animals that have existed for more than 500 million years. They are found in abundance in shallow tropical waters, where sedimentation rates are low, nutrients are scarce, and water temperatures are warm. They also have a wide variation in morphology which allows them to better adapt to the different environments in the ocean. The base of a coral is called the corallite. The corallite is made of calcium carbonate and contains the polyp. The polyp is the softer portion of the coral that surrounds its mouth. The polyp further extends to tentacles that contain cnidocytes. Cnidocytes enclose structures called nematocysts that help the coral capture its prey. Each nematocyst is attached to a thread on one end, and the other end of the thread can be barbed. When a prey is detected, the thread is ejected from the nematocyst to either trap or inject toxin into the prey. The prey will then be devoured in the stomach of the coral and any waste will be expelled back out from the mouth.

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Coral Polyp. Credit: Wikipedia

Corals come in a variety of shapes due to the differences in wave strength and sunlight of their location in the shallow ocean waters. For example, corals that live deeper on the reef tend to be flat to better capture sunlight and food, whereas corals that live closer to the shore branch out so the strong ocean waves don’t break them. Perhaps all these factors combined is what helped corals exist for such a long time.

Coral outcrop on Flynn Reef

Coral outcrop on Flynn Reef. Credit: Wikipedia

Above all, corals display an interesting symbiotic relationship with a dinoflagellate called zooxanthellae. These zooxanthellae are photosynthetic algae that live in the polyps of corals. One advantage of their relationship is that through photosynthesis, zooxanthellae supply high amounts of oxygen for coral. A second advantage is that zooxanthellae provide as much as 95% of the coral’s energy source.In addition, zooxanthellae help increase calcium concentrations for the corals to use for corallite formation. It was found that corals with zooxanthellae can grow three times faster than corals who don’t have zooxanthellae. In a research done by Pearse and Muscatine, they also found that “corals with symbiotic algae calcify many times faster in light than in darkness, while corals which have lost their zooxanthellae calcify at rates which are slower and unaffected by light”. Pearse and Muscatine also looked at the relationship between the uptake of phosphate by zooxanthellae and growth of corals. It is hypothesized that the uptake of phosphate by the algae can assist calcification in corals. However, the results found under their conditions were not significant, otherwise there would be a fourth advantage to the symbiotic relationship between coral and zooxanthellae. As for zooxanthellae, the coral provides them a place to live, a supply of carbon dioxide to use in photosynthesis, and protection.

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Coral and Zooxanthellae. Credit: Ocean Portal

I believe that these are the unique features of corals that helped them exist since the late Cambrian period. Their symbiotic relationship with zooxanthellae is even more fascinating. Corals and their algae friends are still being researched to find more advantages in their symbiotic relationship. Without these algae, corals certainly have a decreased chance of survival.

Here is a short video on Coral:

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Stephanie Lam

The Benefits of Fad Diets: The Ketogenic Diet

Dieting is one of the hottest topics of the 21st Century, as many different diet plans surface the internet each day. According to the summary by Medical News Today, the most talked about diets include the Atkins Diet,  Zone Diet, Vegetarian Diet, Vegan Diet, Weight Watchers Diet, South Beach Diet, Raw Food Diet, and Mediterranean Diet. Different types of diets are chosen depending on the lifestyle people aim for. However, there is one type of diet that has been raved about in the medical field. The Ketogenic Diet, first developed in the 1920’s to treat epilepsy, has now become a recommended diet for tumor patients.

The Ketogenic Diet and a normal diet differ in the amount of macronutrients eaten. In a normal diet, people eat large amounts of carbohydrates, which is then broken down into glucose by insulin. These glucose molecules are used by cells as an energy source. However, when glucose sources become depleted, normal cells can gain energy through other sources like stored fats. Tumor cells cannot find any other way to gain energy and heavily rely on glucose as the only energy source. Therefore, by restricting the intake level of carbohydrates, the glucose levels become depleted and tumor cells die from a lack of energy source.

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Structures of glucose and carbohydrates. Credit: Blend Space

The Ketogenic Diet works by restricting the intake of carbohydrates to the lowest amount while increasing the intake of fats and proteins to maintain sufficient energy levels.

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Credit: Meta Ketosis

The diet typically consists of high fat consumption (70-75% of total calories), moderate protein consumption (20-25% of total calories), and low carbohydrate consumption (5-10% of total calories).

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More bacon please! Credit: Vanity Buzz

The high fat consumption compensates for the low carbohydrate intake. Thus, normal cells begin to breakdown fats for energy. The moderate protein consumption controls the amount of insulin, which further prevents the breakdown of glucose. In addition, high insulin levels restrict ketosis from occurring.

As humans’ main source of fuel, diets play an important role in every individual’s health. As healthy individuals we should follow a regular diet instead of pursuing fad diets. However, special diet plans such as the Atkins Diet is still useful in the medical field for improving the health of tumor patients, and should not be easily overlooked. If you’re interested, please take a look at this video to see how this man beat cancer with the Ketogenic Diet:

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Stephanie Lam

It’s All in Your Head-Men and Women Wired Differently for Emotions

Joy, Sadness, Fear, Anger, Disgust- these five characters from Inside Out are emotions that we know all too well. Sometimes, we experience them more often than we would like to. However, have you noticed how emotions affect each person differently, especially between men and women? I came across this question while I watched this video, which is part of a project called “The And”. A couple sat down for the first time in two years after their break up and asked each other a series of intimate and emotional questions.

As my friend and I watched this couple revisit their past relationship I experienced a roller coaster of emotions. I found myself fluctuating from being on the brink of tears to hysterical laughter. As for my friend, he seemed amused yet unaffected by the emotions. In fact, he was very concerned that the girl had not moved on since the break up. Seeing this difference made me think: is it possible that men and women simply process emotions differently?

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Credit: http://www.mybraintest.org/

We already know that the human brain consists of a left and right hemisphere. The left hemisphere is considered the logical side, whereas the right hemisphere is the creative side. We also have parts of the brain that help respond externally, and others that respond internally. So how might this affect the processing of emotions between men and women?

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Picture of the brain. Credit: The Thinking Business

In Robin Lloyd’s article, he states that scientists have found evidence that men and women were wired differently for emotions. Studies have found that when overwhelmed by fear, men tend to respond physically while women respond more emotionally. This difference is the effect of the communication between different regions of the brain and the cluster of neurons, which are found in both men and women.

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Picture of a network of neutrons. Credit: http://wespeakscience.com/scientist-transform-blood-cells-into-neurons/

If that’s not interesting enough, Larry Cahill and his team from University of California Irvine did a study on a particular group of neurons, called amygdala.This team of researches found that while the more energetic group of amygdala neurons in men are located in the right hemisphere, the more active group of amygdala neurons for women are located in their left hemisphere.

So females aren’t just more emotional, they are also wired differently from men to begin with. It’s fascinating how the same group of neurons in human beings can affect them in completely different ways, making each of them a unique individual. Inside Out illustrates this interesting scientific theory in an unique standpoint, making it easier to visualize and understand. The short trailer from Inside Out gives a quick glance into the differences between the emotional wiring of men and women. If you haven’t watched it, I strongly recommend that you do:

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-Stephanie Lam