Possibility of Life in Mars

Posted on October 26, 2015 by | Leave a comment

Mumma, Michael J. in the article “The Search for Life on Mars” states that because of considerable similarities of earth and mars, it may be possible that life exists in some forms in Mars. Although, up to now, there has been no evidence to prove the idea of existence of life in Mars, recent discoveries propose that Mars was once habitable.

https://upload.wikimedia.org/wikipedia/commons/3/36/Mars_Valles_Marineris_EDIT.jpg

https://upload.wikimedia.org/wikipedia/commons/3/36/Mars_Valles_Marineris_EDIT.jpg

           Mars
Credit: Wikimedia

Scientists have conducted several investigations and researches in order to prove the possibility of life in Mars. Finding factors that are vital for the possibility of life, has been the most important goal for NASA. For example, NASA has done many studies by “Mars curiosity rover” and “Mars opportunity rover”.
For this purpose, scientists use an approach that includes 19 or 20 abiotic factors, with an emphasis of availability of liquid water, presence of nutrients, temperature, sources of energy and protection from cosmic radiation.

https://upload.wikimedia.org/wikipedia/commons/7/77/Mars_Rover_Curiosity_in_Artist's_Concept,_Wide.jpg

https://upload.wikimedia.org/wikipedia/commons/7/77/Mars_Rover_Curiosity_in_Artist’s_Concept,_Wide.jpg

                      Curiosity Rover
                    Credit: Wikimedia

Some liquid water may flow on Mars surface, this can happen only under very specific conditions. Due to the atmospheric pressure of Mars water evaporates or freezes quickly. Therefore, it is very hard to find liquid water on Mars.

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                          Water Flowing on Present-day Mars
                                                 Credit: NASA

As we know existence of elements including: carbon, nitrogen, oxygen, hydrogen, phosphorus and sulfur are necessary for life. Many. Studies have shown that these elements are present in surface of Mars in some rocks. In turn , this can lead to an increase in possibility of life.

Another parameter that contributes to the possibility of life Mars is energy needed for metabolism. This can either be met by solar energy or geochemical energy.

Temperature also plays an important role in possibility of life. Because of loss of atmosphere in Mars, temperature has decreased significantly during the time.

Finally, because there is no global magnetic field in Mars to protect the planet from the life-threatening cosmic radiation, existence of life may not be probable.

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                                      Wind and radiation on Mars
                                                     Credit: NASA

To sum up, because there is lack of factors that are essential for existence of life in Mars, the idea of existence of life in Mars has a long way to go. However, with advancements in technology, we can hope to discover more evidence needed for life in Mars.

Kamyar Kazemiashtiani

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New AIDS vaccine trials to be performed on Humans for the first time in history

Posted on October 19, 2015 by | 1 comment

In 1984, Human immunodeficiency virus (HIV) was discovered by a team led by Dr. Roberto Gallo, which opened the gates for mankind in order to gain more knowledge about this deadly incurable disease which was the reason for the deaths of millions of people. As the director of the Institute of Human Virology (IHV), Dr. Roberto Gallo is now launching the institute’s first clinical trial of a vaccine for AIDS – a project that has been 15 years in the making.

HIV is one of a group of atypical viruses called retroviruses that maintain their genetic information in the form of ribonucleic acid (RNA). HIV virus has an enzyme known as reverse transcriptase, which makes it capable of producing deoxyribonucleic acid (DNA) from RNA, whereas most cells carry out the opposite process, transcribing RNA from DNA. The activity of the enzyme enables the genetic information of HIV to become integrated permanently into the genome (chromosomes) of a host cell. Since HIV virus controls the genetic information of the cell, it makes the cell produce more HIV virus using the host machinery, thus replicating at a fast rate. With HIV’s inherent ability to rapidly mutate and escape the immune system, conceiving an effective vaccine against it has been a seemingly difficult challenge.
Mechanism of HIV virus invading a human cell

Mechanism of HIV virus invading a human cell

It is found that when HIV infects a person, its surface protein called gp120 attached itself to another protein called the CD4 receptor, which is found in the white blood cells. When it binds to CD4 cell, it can change shape to avoid recognition from neutralizing antibodies which is the usual immune response form the body. This conformational change allows it to bind to a second receptor called a co-receptor, on CD4 cell surface. Once it has a grip on both HIV envelope protein fuses with the cell membrane, thus once within the cell, HIV is safe from attacks from antibodies. 
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The experimental AIDS vaccine, called as “Full length single chain” vaccine contains an HIV surface protein gp120, engineered to link to a few portions of the CD4 receptor. The main aim is to trigger antibodies against gp120 surface protein when it’s already attached to CD4 and the transitional state in which the protein envelope is present is vulnerable to be attacked, thus effectively stopping it from attaching to the second site of co-factor attachment.
According to World Health Organization (WHO), AIDS has been held responsible for over 1.2 million people in the year 2014, if this vaccine turns out to be effective, it could change the world.
-Rikul Thapar
 

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The Benefits of Fad Diets: The Ketogenic Diet

Posted on October 19, 2015 by | 2 comments

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.

carbohydrate-diagram

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.

ketogenic_diet_flowchart

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).

dockers-diner

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

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Science in the Kitchen

Posted on October 19, 2015 by | 2 comments

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

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Sweet Addiction

Posted on October 18, 2015 by | 1 comment

European_honey_bee_extracts_nectar

Early mornings and long hours call for a nice cup of coffee, and it seems that honey-bees agree. Dr. Margret Couvillon of the University of Sussex led a team of researchers testing bees’ response to a sucrose solution with and without a dose of caffeine, the study was published in the Cell Press journal Currrent Biology Thursday October 15. The caffeine present was in concentrations that are naturally found in nectar, and the bees found this to be a higher reward than the decaffeinated version.

Upon returning to the beehive, a sheltered structure,  the bees appeared to be more hyperactive and were more than willing to share their new find, via the “waggle dance”. The waggle dance is a special behavioural technique used to communicate food sources to fellow hive members. The dance is modified based on how much sugar the food source has, the more frequent the waggle the sweeter the nectar. However, caffeine seemed to override this connection because the bees performed the waggle dance 4 times more often after enjoying some caffeinated-laced nectar, encouraging other bees to visit the site. As is appears, the dance is only performed for the very best sources, and the plants have the upper-hand when recruiting loyal customers. Talk about a caffeine buzz.

Coffee_bean_transparent

Plants may be masking their nectar as a high quality source, by lacing it with caffeine, and encouraging bees to visit more often. Dr Couvillon says, “Some plants, through the action of a secondary compound like caffeine that is present in nectar, may be tricking the honey bee by securing loyal and faithful foraging and recruitment behaviours, perhaps without providing the best quality forage.”

It was also observed that bees visited the caffeine laced feeders numerous times, well after the feeders were emptied, and were less inclined to search for a new site. The bees tended to overvalue a caffeinated nectar source, suggesting the possibility of plants lowering their nectar investment but still receiving high visitation from loyal customers.

Most are guilty of enjoying a hot cup of coffee for that little caffeine boost, but could bees be taking this a little too far? Seems like plants are being less mutualistic than we expected by taking advantage of our little worker bees. That must sting.

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Credit: BBC News

Danielle Marcotte

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Metal Can Sit on Dandelions?

Posted on October 18, 2015 by | 4 comments

Boeing, one of the world’s leading airplane manufacturers, along with the help of HRL laboratories, University of California, and Caltech has developed the lightest metal structure on earth. It is called the “ultralight metallic microlattice” and it composed of 99.99% air. So far, this structure can be made of any material, but it is easiest made with nickel.  Remarkably, this new material is 100 times lighter than Styrofoam and it is so light it can sit atop a dandelion without crushing the delicate seeds!

The delicate seed heads of the dandelion.

Delicate seeds of the dandelion. Credit: Greg Hume

How can this material be so light? It is all related to the structure of it. The architecture of the ultralight metallic microlattice is created by hollow-tubed microlattices that are arranged to resemble the honeycomb structure of the human bone. Is human bone not dense and rigid? The outer casing of bone (compact bone) may be dense and rigid; however, inside the bone (spongy bone) is mostly hollow with an open cellular structure, much like a kitchen sponge, which allows it to be airy and lightweight.

The cross-section of a bone. Notice the special structure of the spongy bone.

The cross-section of a bone. Notice the special structure of the spongy bone.

To create this product, researchers created thin, hollow struts with a diameter of only 100 to 500 micrometers and a wall thickness of only 100 to 500 nanometers to mimic the architecture of the spongy bone. To give a comparison, this wall would be 1,000 times thinner than a human hair.

As well as being lightweight, this material is also one of the strongest in the world. It can be designed to maximize energy absorption which makes it a useful insulator. As an insulator, it can dampen shock, vibrations, and acoustic energy and therefore this material can be widely used across many fields of technology. Furthermore, this material is able to completely recover from a compression of over 50% strain.

With this discovery, Boeing has been investigating possible ways to implement  this material in planes. This would create lighter airplanes which would create more fuel efficient flights. Boeing has created and sold many Boeing 787, Dreamliners, which already consume substantially less fuel and with this new material, optimistically there is a possibility that Boeing will soon be creating the world’s most fuel efficient flights!

Here’s a video from Boeing which summarizes the “world’s lightest material”:

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Lightest Metal Ever
Credit: Boeing

– Maureen Lai

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Meditation, is it a waste of time?

Posted on October 17, 2015 by | 3 comments

For thousands of years’ people have practiced meditation for spiritual, emotional and physical well being, yet without much evidence of its effects. It is known that meditation can relieve stress, lower blood pressure and lift someone’s mood. But it is only in the last 15 years have neuroscientists taken a serious look at the changes in brain structure underlying some of meditations benefits.

https://www.bulletproofexec.com/benefits-of-meditation-how-to-meditate/

Image from: bulletproofexec.com

Like during everything we do, meditation rewires our neural circuits, pruning away the least used connections and strengthening the ones we exercise the most. Studies looking for signs of these changes focus on ‘mindfulness meditation’, which challenges people to keep their attentions fixed on their thoughts and sensations in the present moment. Earlier on, scientists acknowledge that many of these studies are small and not ideally designed. But now, researches have gathered enough evidence to be confident that their findings are not just a fluke. Experiments suggest that Buddhist monks have more robust connection between scattered regions of their brains, which allows for more synchronized communication. Expert meditators also seem to develop an especially wrinkly cortex (the brains outer layer), which we depend on for abstract thought and introspection. Several studies have confirmed that meditation can increase the volume and density of the hippocampus, which is crucial for memory.

Studies show that 10-20 minutes of meditation a day sharpens the mind. When scientists compared the brains of the monks to those of new meditators, they found the region of the brain associated with empathy to be much more pronounced in the monks. These studies also show that prolonged meditation can alter your brainwave frequencies, exhibiting higher levels of Alpha waves that help reduce feelings of negative mood, tension and sadness.

In an 8-week study meditators showed increase in the density of grey matter in brain regions involved in learning, memory processing and emotion regulation. While in the amygdala, which deals with stress blood pressure and fear, grey matter decreased. In these studies, meditators scored higher on tests of attention and working memory, which is the ability to store and manipulate information in one’s mind. Although areas of the brain involved in sustaining attention deteriorate as we age, meditation counteracts this decay.

Meditation not only affects the mind but the body as a whole. In a study where both meditators and non-meditators were given the flu virus, meditators had produced a greater number of anti-bodies and had increased immune function. Meditation also showed advantages on the cellular level where lower levels of stress increased the function of the enzyme telomerase that counteract the shortening of DNA telomeres, which are linked to cardiovascular diseases, diabetes, cancer and aging.

Of course meditation is not a substitute for other medical advice or a healthy life style, but much like hitting the gym can grow your muscles and increase your overall health, it seems like meditation is a way to workout your brain with extra health benefits.

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NeuroMythBusters – Breaking Down Issues in Science Literacy

Posted on October 17, 2015 by | 2 comments

As upper-level students at a renowned university, we often pride ourselves on an excess of scientific knowledge. So let me begin by testing that knowledge base.

True or False:

Children are less attentive after consuming sugary snacks or drinks.

There are distinct types of intelligences, and learners have a unique combination of each.

Left or right brain dominance can result in differences in learning ability.

You may be surprised to learn that the answer to each of these statements is false.

But how? These ideas have been taught by a plethora of teachers, science or otherwise. And based on a study by Paul A. Howard-Jones, many educators do believe that the above statements are scientifically accurate.

Teacher at Chalkboard, via Flickr (cybrarian77)

Teacher at Chalkboard, via Flickr (cybrarian77)

These commonly misunderstood notions, or neuromyths, can be attributed to issues in science literacy and science communication as a whole. I will address a few of these problems as they pertain to the neuromyths above.

1. The use of jargon in surveys and articles

57% of teachers in the UK believe that sugary products make students less attentive. However, studies have proven that there is no connection between sugar and hyperactivity. This idea may be propagated by a difference in understanding – teachers comprehend the word ‘attention’ in terms of behavior compared to neuroscience’s cognitive terminologies. As well, the unnecessarily complex and technical jargon in journals makes it difficult for non-specialists to understand the exact meaning, often leading to oversimplification.

2.  Difficulty in testing

Howard Gardner By Interaction-Design.org [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

The idea that intelligence cannot be quantified by a single general ability is a popular one. This theory, introduced by Howard Gardner in his book Frames of Mind: The Theory of Multiple Intelligences gained traction because everyone wanted to believe they were smart in some way. A critical review has argued that there is a lack of empirical evidence to support this theory; yet Gardner claims that it was misunderstood. Furthermore, the complexity of the brain makes it nearly impossible to test its legitimacy. When ideas cannot be definitively tested or counter-evidence is not clear, it is easy for the average reader to simply accept ideas.

3. Misinterpretation of graphs and images

H. Garavan, Proceedings of the National Academy of Sciences of the United States of America

Activation of right hemisphere during inhibition control via H. Garavan, Proceedings of the National Academy of Sciences of the United States of America (1999)

Educators are encouraged to determine the dominant side of a learner’s brain in order to teach better. While it is true that different brain regions are preferred for different tasks, the idea of hemispheric dominance has no scientific basis. This neuromyth has been aggressively promoted due to misreading of neuroimagery that shows ‘hot spots’ in the brain. Graphs and images are meant to present information in a straightforward manner; however, non-specialists can be easily led to believe there is a greater significance than what is presented.

So where does this leave us? It is obvious that scientists need to do a better job balancing simplicity and detail, whether it be in the form of words or graphs. Nevertheless, it is encouraging to know that while people may not know a lot about science, they still hold a positive view of scientists and consider scientific progress important. If we can continue to build understanding between science and the public, future generations will develop both skill in critical analysis as well as a fervor for scientific advancement.

Famed astrophysicist Neil deGrasse Tyson on scientific literacy:

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Tim Cheung

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