Category Archives: Uncategorized

How is your brain able to focus on what is important ?

Posted on February 26, 2012 by | 2 comments

Do you ever wonder how your brain is able to selectively focus on certain things and not on others?  At Carnegie Mellon University, the neuroscientists discovered what drives such process. Through various brain imaging techniques, the researchers were able to see how pariental cortex and visual cortex communicate with each other through white matter by sending neural signals and help the brain certain  visual information. For example, if one was looking for keys in a purse full of stuff, the brain would have to selectively work to locate the specific item.

Neuroscientists conducted two experiments with five adults. In order to first identify brain regions responsible for visual processing and selective attention, they made a couple of different brain scans while the participants were doing selective attention exercises. Then, while the participants were not performing any tasks, the researchers  collected anatomical data of the white matter that serves as a connection between visual cortex and pariental cortex.

The results indicated that there are direct connections in corresponding visual field locations between pariental and visual cortex, while the white matter connections are mapped in systematic, direct way. It is known that training can alter white matter activity. This brings out a new idea, that through careful training, it would be possible to help the brain filter out unwanted information and focus on important one, easier.  This could be helpful for University students, by helping them study more efficiently. Also people having a high stressful job, such as emergency room doctors and surgeons, would have an easier time thinking on how to react in certain situations.

For more information on the big picture of neuroscience, watch this video:

 

References:

Carnegie Mellon University (2012, February 21). Neuroscientists identify how the brain works to select what we (want to) see. ScienceDaily.

Youtube video: https://www.youtube.com/watch?v=RREoQJUHSYE

 

 

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Posted in Uncategorized

The ozone hole is NOT a hole!

Posted on February 25, 2012 by | 2 comments

What exactly is the ozone hole? The ozone hole is not actually a hole. It is where the ozone layer is depleted with ozone, O3.  

There are different layers of the atmosphere around the Earth. Troposphere is 0 to about 8 to 18 km in altitude above the surface of the earth. Stratosphere is from troposphere to 50 km in altitude. Stratosphere is the region of high ozone concentration.

Picture from: http://en.wikipedia.org/wiki/File:Atmosphere_layers-en.svg

Where are ozone holes? Ozone holes are at the stratosphere over the Antarctic and the Arctic. The hole is found much bigger over the Antarctic, the region around the South Pole.  Ozone concentrations over these regions are decreasing annually.

File:160658main2 OZONE large 350.png

picture from : http://en.wikipedia.org/wiki/File:160658main2_OZONE_large_350.png

This is a figure of the Earth. The blue part is the ozone hole with low ozone concentation.

How do ozone holes form over the Antarctic and Arctic? Due to very low temperature in these regions, polar vortex forms. This isolates the atmosphere from the rest of the stratosphere and causes no air movement. Polar Stratospheric Clouds or PCS form that amplify ozone depletion by the catalytic cycle of atomic halogen. They do not happen over other area in the stratosphere because the weather is not as cold as the poles.

Why do we care about the zone hole or the ozone layer? Sun emits harmful UV radiation such as UV-B and UV-C which threatens all lives on Earth. The ozone layer absorbs all UV-C and most UV-B and blocking them from reaching the Earth. The ozone hole is getting bigger every year and this means that more UV radiation can reach to all lives on Earth. Two percent increase in UV correlates with 3.5% increase in basal cell cancer (Wheeler 2012).  UV-B causes 90% of human skin cancer (Wheeler 2012).

We should use sunscreen every morning! Sunscreen decreases the amount of UV-B that can reach to our skin and blocks out UV-A.

YouTube Preview Image

Sources:

Wheeler, M. 2012. UBC  chemistry 302 notes.

Wikipedia. Ozone Depletion. http://en.wikipedia.org/wiki/Ozone_hole (accessed 2/ 24/ 2012)

Wikipedia. Ultraviolet. http://en.wikipedia.org/wiki/Uv (accessed 2/ 24/ 2012)

Wikipedia. Polar Stratospheric Clouds.  http://en.wikipedia.org/wiki/Polar_stratospheric_clouds(accessed 2/ 24/ 2012)

 Youtube. Sunscreens: SPF50 protects five times better than SPF10. https://www.youtube.com/watch?v=8cc8qRr7oMQ&feature=related (accessed 2/ 24/ 2012)

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Posted in Uncategorized

Who is Our Ancestor?

Posted on February 13, 2012 by | 6 comments
This is Our Ancestor. Image by Prave.

Scientist belive they have found our oldest ancestor, the creature, Otavia antiqua, was found in 760-million-year-old rock in Nambia. This multicellular being spawned every living organism in this world through billions of mutation, from fish to amphibians to reptiles to birds to animals to you.

 
Otavia was a very small sponge “about the size of a grain” according to Anthony Prave, a geologist at the University of St. Andrews in the U.K. According to Prave, “certain samples would “yie thousands of specimens. Thus, it is possible that the organisms were very abundant.”
 
Based on where the fossils were discovered, Prave and his colleagues claims that it used to live in calm, nice, shallow waters, munching on algae and bacteria through pores and into its small tube body.
A scanning electron microscope view of Otavia antiqua.
A scanning electron microscope view of Otavia antiqua. Image by Prave.

 Our Ancestor is also very reslient. According to the South African Journal of Science, it survived atleast two “snowball Earth”  events, when the entire planet was almsot entirely covered with ice.

Despite the wild enviornmental swings, this creature remained almost unchanged, resisiting along with algae and bacteria for “roughly 200 million years of existence.” Prave suggested.

Paleontologist Dr. Bob Brain – who is an expert in predation- belives that Otavia was the Earth’s first predator. During the early days, it was at the top of the food chain, consuming its food while it had no means to hunt. According to Brain, this was the first evolutionary arms race, which “led to humans dominating the planet.”

References

  1. Oldest Animal – Earliest Ancestor of Us All? http://news.nationalgeographic.com/news/2012/120207-oldest-animals-sponges-earliest-science-evolution/ (accessed 02/12, 2012).
  2. Sponge-like creaure may be oldest animal ever found. http://www.iol.co.za/the-star/sponge-like-creature-may-be-oldest-animal-ever-found-1.1227656  (accessed 02/12, 2012).
  3. The oldest animal fossils. http://www.sajs.co.za/index.php/SAJS/article/view/1064/1048 (accessed 02/12, 2012).
 

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Posted in Biological Sciences, Fun!, Science in the News, Uncategorized

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A Lovely Indecision

Posted on February 13, 2012 by | 5 comments

There’s hardly anything as conflicting as tastes, especially subconscious tastes that vary on a monthly cycle and alternate with circumstance. In honour of Valentine’s Day, we shall explore the theme of indecision in female mate selection, featuring the wonders of the pill.

To begin, attraction in females shifts between when she’s ovulating and not.

While in the fertile throws of follicle phase, females generally prefer a male with manly features and high testosterone levels, as well as a dissimilar Major Histocompatibility Complex (MHC). MHCs are linked to immunity, so humans naturally seek to diversify for maximum heterozygosity and variation. A fun fact, while fertile, girls in relationships are also known to develop a taste for dominant smelling men.

YouTube Preview Image (A little More on MHC)

Most of the time though, women are not in fertile mode, and in these circumstances tend to fall back on men who have a similar MHC to themselves. They also favour men who are less masculine and more nurturing and supportive, especially if they live in a healthy environment.

Based on these natural cycles, we can see how there might be some conflict of interest depending on what day it is.

"I don't know what I want!" Image:ehow.com

Sometimes, one doesn’t even need cycles to complicate things. While single, girls have an increased preference for MHC similar men, but then have dissimilar MHC preference when they’re already with someone. If that’s not enough, these changing preferences of MHC make a huge impact as scent is much more emphasized in importance with women rather than men. Occasionally, scent can even be at odds in importance with visuals though it varies on the population and culture.

That said, a person’s heterozygosity of their MHC can be sensed through the inspection of facial features. While females favour as much heterozygosity as possible, they seem to be attracted to those with similar MHC as well.

So, visuals conflict with olfactory cues? Awesome.

Now what about the pill? Surely this fabulous contraption of contraception must simplify things no? Well, sort of.

”The Pill adds some consistency, whereby everyday is non-fertile day. It’s more or less a fake pregnancy that replaces the possibility of a real one, and this causes women to go into “find a nurturing, similar man phase.” It’s without any surprise then that women on the pill have a marked preference for MHC similar men that totally overrides any ambition for seeking a dissimilar partner.

Consistency? Fabulous! What’s the catch?

Women who find their man on the pill tend to have less sexual attraction to their partners as well as decreasing sexual satisfaction over time. They become very jealous at a rate proportional to estradiol intake, and also have an increased desire to cheat, meanwhile having much more severe “affective responses” to partner infidelity, and having an increased frequency of “mate retention behaviour.” And you put on a few :3

But don’t worry, there are some positives. Those that meet their partner on the pill have more satisfaction with their partner in non-sexual ways, have happier relationships with more emotional satisfaction, and have relationships that last 2 years longer on average.

So really no matter what, it’s a mess of matter of preference. Just have a preference for the mess that you prefer.

"Use Both Instead!" Image:ehow.com

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Posted in Biological Sciences, Fun!, Science Communication, Uncategorized

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Black Stripes White Body or White Stripes Black Body

Posted on February 13, 2012 by | 7 comments

Zebras are the cute animals living on grasslands. Have you been wondering if they have black stripes with white body or white striples with black body? And, what are the stripes for anyway?

Revealing the mystery, zebras have black body and white stripes. According to Wendy Zukerman, the zebras are completely black in their early embryo stages, while the white stripes appear later on.

Also, Lisa Smith has reported that the black color is the pigment activation and the white color is the inhibition, meaning that the color of fur is orginally black while the white fur simply lacks the pigment.

Although scientists are not sure why zebras have the alternating stripes, there are some theories

Having a higher albedo, the alternating pattern of fur can deflect up to seventy percent of heat during daytime. Since a lot of zebras live in high temperature enviroment, the fur can reduce a lot of heat from the sun.

Moreover, one theory says that the alternating pattern can act as a camouflage to confuse the predators. The Stripes can form some kind of illusions to intimidate the predators like lions or hyenas. The illusion is especially effective when the zebras are in a great number, so the pattern may make them look like a giant creasure.

While there is little evidence for camouflage, a new finding Justin Marshall points out is that the pattern can get rid of horseflies becasue it “provides an unattractive surfaces” for horseflies to land on. In africa, there are a lot of horseflies, so a pattern that prevents horseflies would result in less disease and healthier zebras.

A short video about horsefly theroy.

YouTube Preview Image

So the black zebras with white furs stills have their alternating pattern remained mystery. More studies are need to to support the theories such as camouflage and horsefly.

 Source

Buzzle.com.

How Stuff Works.

New Scientists.

 

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Posted in Biological Sciences, Fun!, Uncategorized

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Doing It The Old Fashioned Way

Posted on February 12, 2012 by | 2 comments

It’s a nightmare scenario to modern science students: facing a physics midterm with a dead calculator. We have all used these miniature computers so extensively in learning math that most of us don’t trust ourselves to do it any other way.

We are all aware that there must have been some stygian era before these wonderful devices came into existence. Calculations must all have been carried out manually. This is not the case. Before there were digital computers, there were analog computers.

The first known analog computer was manufactured around 100 BC. This device, known as the Antikythera mechanism, was used by ancient Greek astronomers to predict the movement of celestial bodies.

A fragment of the Antikythera mechanism. Source: computus.org

Analog computers reached their most advanced forms in the 1950s, when they were used in to aim the weapons of naval vessels. This may seem counter-intuitive; artillery problems are used to teach some of the simplest concepts in first-year physics, surely this could be done by hand. Bear in mind, these simple artillery problems have only two dimensions and involve stationary targets and stationary firing platforms all operating in a frictionless vacuum.

The real world is so much more complex than these problems that fire-control computers accepted as many as 25 variables. For comparison, the simplest kinematics problems have 5 variables. A mathematician could do the same calculation in minutes, at best, and only then for one selected instant. Fire-control required continuous output under constantly changing conditions.

While the history of these devices is interesting, how do they work? To illustrate the basic principle, we’ll construct a very simple analog computer.

For illustrative purposes, our goal will be simple, to divide by two. We will call our known, or input, variable y and our unknown, or output, x. The function calculated is:

 y=2x

To start we have two wheels, which could just as easily be gears, designated A and B.

Public domain

Wheel A has a diameter of 1, wheel B has a diameter of 2. Since circumference is the diameter multiplied by pi, if the outside edge of A were flattened out, it would be half the length of the similarly flattened edge of B. When A turns once, it will roll along half the edge of B, driving a half revolution of B.

Public domain

The revolutions of A represent the input and the revolutions of B represent the output. Six turns of A will produce three turns of B, just as 6/2=3.

To make input and the reading of output easier, we can label the inputs and outputs on the wheels. For simplicity, only a few outputs are labelled, but high resolution can be achieved with the same principle.

Public domain

Here, we see that the input and, consequently, the output, are zero. Rotating A 90 degrees, rotates B 45, so that the input of 2, gives an output of 1.

Public domain

Analog computers have many more complex mechanisms, but the guiding principle is the same; displacement or rotation of components used to model variable values.

This 6 part training film outlines this and many more mechanisms used in mechanical computers.

YouTube Preview Image

References

(1) The Antikythera Mechanism Project The Antikythera Mechanism Project. http://www.antikythera-mechanism.gr/ (accessed 02/12, 2012).

(2) Navy Dept. Bureau of Ordnance In Basic Fire Control Mechanisms; Ford Instrument Co. Inc.: Long Island City, NY, 1944; , pp 425.

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Does Acupuncture Work?

Posted on January 29, 2012 by | 2 comments

Acupuncture was a complementary and alternative medicine (CAM) which introduced into Europe in the 17th century. It is very popular in Asia nowadays, especially in China. However, the use of acupuncture still remains controversial and is not widely accepted.

The procedure of acupuncture is to insert a fine, sterile needle into acupuncture points. Acupuncturists believe we, human bodies, have 360 acupuncture points from head to toe.

    Many doctors and scientists do not truly understand the anatomy and physiology of the acupuncture point. Hundreds of research tried to prove and expand the knowledge of acupuncture. Some were successful but a lot did not.

 

One of the scientific research on acupuncture indicated that this alternative medicine managed to provide pain relief of patients with pain cancer. The use of acupuncture helped them relax their muscles which then improved the pain.  The use of acupuncture also helped treat disease such as obstructive pulmonary disease. Another article by Thomas, M. and Lundberg, T. had an experiment on acupuncture and claimed that it was a good treatment for chronic low back pain.

YouTube Preview Image

According to this video, Dr. Everett Heinze is a neurologist and suggests that putting a needle into acupuncture points causes a reflex relaxation in the muscle and endorphin release in order to provide pain relief.

Although there are many successful cases on this alternative medicine, many people do not accept it and think that is only a placebo effect. Acupuncture needs further investigations.  We hope this one day acupuncture will be proven all around the world and treat diseases alternatively.

 

Sources:

THOMAS, M., & LUNDBERG, T. (1994). Importance of modes of acupuncture in the treatment of chronic nociceptive low-back-pain. Acta Anaesthesiologica Scandinavica, 38(1), 63-69.

Pan, C., Morrison, R., Ness, J., Fugh-Berman, A., & Leipzig, R. (2000). Complementary and alternative medicine in the management of pain, dyspnea, and nausea and vomiting near the end of life: A systematic review. Journal of Pain and Symptom Management, 20(5), 374-387.

youtube video : https://www.youtube.com/watch?v=QM8Of_hpHwQ

images: http://www.indiatalkies.com/images/acupuncture17754e.jpg  ,  http://anaturalday.net/wp-content/uploads/2010/05/acupuncture.jpg

 

 

 

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Posted in Uncategorized

Natural vectors of supernatural bugs, seem to be from humans, naturally.

Posted on January 23, 2012 by | Leave a comment

There seems to be a rising fear of sickness around the world. With ever increasing populations in regions of poor hygiene, international access to transportation, and an abundance of antibiotic resistant outbreaks, its no wonder movies like Contagion can find an audience.

CC by SilentFrenzy

While people realize that restricting access to medical treatment or travel would be inconvenient, most promote awareness of proper antibiotic use and limiting the use of antibacterial soaps. Despite these interventions, the rise of the superbug still remains a problem on our horizon. It would seem pathogens are still developing immunity to our arsenal and that the vast majority are appearing out of nature. Or are they?

While Antibiotic Resistant Genes (ARG) have been evolving in an arms race with toxins and biocides for millenia, there is evidence that human activity may be partially responsible for selective pressures even when these ARGs seem to appear out of nature. Here are two human induced sources that have been until recently overlooked:

CC, by Karen V Bryan

Domestic rearing of animals has long had implications of giving rise to ARGs in bacteria, however the relationship between these pathogens and their aquatic vector to us remains largely unstudied. While practices like composting manure can help eliminate ARG carrying pathogens, bacteria can still survive through animal production wastewater and seep into surface and ground water. Such wastewater derived ARGs have been found making their way through sewage and treatment plants and to our local tap. If this is not enough to worry about, bacteriophages can transmit ARGs to bacteria without selective pressures, and they are even more robust than their hosts in aqueous environments.

NRCS photo gallery (Sarah Minor)

A way to diminish this vector may lie with riparian buffer zones and grassed waterways which reduce the turbidity of water, significantly reducing the viability of bacteria in treatment plants.

 

CC by Maria S

 

Another potential vector is metal. People have long known of the biocidic effects of various metals due to jewellery. The reaction, colloquially called metal allergy, can influence a person’s choice of earrings as much the look itself.

While many have taken advantage of this, think hospitals and plumbing, recent experiments suggest that metal concentration may have an impact on ARGs. Areas of past mining or industrial application have been cited as having higher ARG levels correlated with various metal concentrations. While some researchers maintain that metal resistance does not correlate with antibiotic resistance, proponents of metal derived resistance maintain that it is not the metal itself that creates the resistance but that it increases the frequency of gene transfer which may increase the incidence of ARGs over time. To add credence to their argument, a strong correlation of copper with ampicilin resistance was found in the wild, and further examination is currently underway.

Altogether, we are finding more vectors of ARGs everyday, and that they often have simple causes and occasionally practical solutions. And while we may still fear what we don’t know, it is science that enlightens us with what we do. There is no doubt that with time and the application of science, the rising fears of sickness will dissipate, and some thriller films will be a little less infectious.

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