Friday, April 24, 2015

Brainy Amoeba

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What is an Amoeba?


Amoebas are microscopic organisms.

Many amoebas eat bacteria and other small organisms. They ingest food and nutrients by a process called endocytosis. Amoebas eat by stretching their plasma membrane around food particles and enclosing the material in a vesicle. They usually reside in warm water and in other aqueous environments.

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Amoeba are single-celled, animal-like protists. They are very large compared to other microscopic organisms. Some species are large enough to see with the naked eye. They are referred to as animal-like protists because they take in particles in order to obtain nutrients. There are also plant-like protists which obtain their energy from photosynthesis.

Amoebas reproduce asexually by a process called binary fission. When reproducing the amoeba divides itself into two new organisms.

Most amoebas are equipped with something called pseudopods. The pseudopods allow the amoeba to move around and capture food particles.
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According to a study of Northern Virginia ecology by the Island Creek Elementary School, “amoebas eat algae, bacteria, other protozoans, and tiny particles of dead plant or animal matter.”

Amoebas are an essential part of life. They provide a source of food for filter feeders and also control algae and bacteria populations. However, some of these creatures don’t just feast on small organisms.


Brain Eating


A few years ago there was an outbreak of an infection called PAM or primary amoebic meningoencephalitis in the southern United States. This infection is actually caused by a type of amoeba. The amoeba feeds on the cells in the brain, sucking the nutrients out of them.
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The culprit is Naegleria fowleri, a species of amoeba that lives in warm, fresh bodies of water. According to WebMD, they are found in warm lakes, ponds, muddy pools, warm shallow rivers and streams, poorly treated swimming pools, hot springs, and runoff waste water used for cooling in power plants.

N. fowleri thrives in heat. The creatures are most active in high temperature water, ranging up to 115 degrees Fahrenheit. If the temperature gets too low, or conditions become unfavorable in some other way, the amoeba will curl up into a cyst, a small mass with a hard protective layer, and only emerge when the environment is suitable.

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According to the Stanford University website, these creatures were officially discovered in 1965 by Dr. Fowler and Dr. Carter in Australia. Of course it came from Australia. Everything deadly lives in Australia.
It is believed that the first documented occurrence of PAM was in 1909. However, the condition is very rare. From 1962 to 2013 only 132 cases have been attributed to Naegleria fowleri. However, the mortality rate is over 98%.

In the past few years, several people died from amoeba infection. There was a 9 year old girl in Kansas who passed away after swimming in a lake near her home.
Symptoms of this amoeba’s presence in the body are caused by destruction of brain tissue.

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According to the Centers for Disease Control and Prevention, symptoms begin to appear about 5 days after an individual has been contaminated and include “headache, fever, nausea, or vomiting.” Following this the condition of the individual declines and he may experience “stiff neck, confusion, lack of attention, loss of balance, seizures, and hallucinations.” After symptoms first reveal themselves the infected individual usually dies in around 5 days, meaning after infection a person has about 10 days to live.

How Amoeba get in the Brain


These amoeba rarely infect humans. However, several cases have been reported in the southern United States.

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Naegleria fowleri usually only get into the brain if water is forced into the nose. This can happen during water sports, such as water skiing and diving. However according to the Centers for Disease Control and Prevention, if water containing the amoeba is consumed, it will not enter the brain and you will be perfectly fine. The conditions have to be just right for the amoeba to cause PAM.

Prevention


If you’re really worried about getting a tiny protist up your nose, the simplest solution is to wear nose plugs while swimming or participating in water sports.

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It is also best to use boiled water and sterile instruments if you need to use a neti pot.


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Friday, April 17, 2015

Ultimate Survivors

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Water Bears


When you think of animals that can survive anything, even a nuclear apocalypse, you probably think of cockroaches. However, there is an animal that can survive even greater extremes.

The tardigrade is a microscopic organism that can survive radiation, freezing and boiling temperatures, extreme pressure, and even extreme dehydration.

According to BBC, “Tardigrades were discovered in 1773 by a German pastor named Johann August Ephraim Goeze.” They are invertebrates.

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Tardigrades are also called moss piglets and water bears. They have eight legs, tiny claws, and small chubby bodies.

They live in aqueous environments and feed on plant material. Many water bears are found in the ocean and other bodies of water. They live on land but to thrive they need a little bit of water.

Moss, lichen, and algae are common food sources. Some eat other small organisms. They feed by sucking the juices out of other life forms.
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According to National Geographic, water bears have sharp little spears in their mouths which they use to eat algae and other tiny creatures.

 It’s common to find water bears crawling around on moss. However, water bears have even been found in deserts.

There are over 900 known species of tardigrade. They have been found in the Himalayas, hot springs, and even in Antarctica.


Extremes

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Tardigrades can survive temperatures ranging from near absolute zero to above the boiling point of water. They can survive pressures at the bottom of the ocean and even in vacuums. Water bears can also survive extreme radiation.


Tardigrades need water to eat, reproduce, and thrive. However, they can live without water for over a decade and some types of tardigrades may be able to live without it for a century.

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According to Microbial Life: Educational Resources, water bears can survive temperatures as low as -328 degrees Fahrenheit and as high as 304 degrees Fahrenheit. They can withstand 1,000 times the deadly human dosage of X-ray radiation and pressures as much as 6 times that of the deepest parts of the ocean.

Pretty tough for an animal only 0.05 to 1.2 millimeters long.

How is this Possible?


Tardigrade can survive extreme conditions. They have evolved the ability to dehydrate themselves and slow their metabolism, forcing themselves into a kind of suspended animation. This allows them to survive all sorts of environments.

The kings of survival.
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According to Popular Mechanics, tardigrades can survive with as little as 3% their total water mass and can slow their metabolism down to 0.01%.

When faced with harsh conditions, the bears curl up inside themselves and shrivel up.

It’s uncertain how long tardigrades can survive in this state, anywhere from a decade to a century. However if not in suspended animation water bears typically only live a few months.

An Italian scientist found a tardigrade in an old, dry piece of moss in 1948. The moss was over 120 years old. When rehydrated the water bear was found to be alive!
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Space


Scientists have been studying water bears for some time in an attempt to determine if their survivability could help humans. Many space agencies have sent water bears into space.  

In 2007, scientists in Europe sent tardigrades on a journey on the outside of a FOTON-M3 rocket, leaving them in space for ten days, and then brought them home. It was found that 68% of the water bears survived the trip. Some had even laid eggs, producing healthy offspring.

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Studying these creatures has huge implications for human space travel. If scientists can figure out how to apply some of this creatures' natural responses to humans, we could travel to the stars in suspended animation.

If a species can survive in space the same way the water bear can then this also increases the likelihood that other planets have life. Microorganisms like the tardigrade could easily hitch a ride on an asteroid to another planet and if conditions were hospitable enough, populate the surface with life.

*wriggle, wriggle*
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I find these creatures extremely adorable. Look at his cute little legs!

Thanks for reading!


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Friday, April 10, 2015

There Mite be Something on Your Face

Demodex folliculorum
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Life within the Body


The human body is filled with organisms. You’re host to millions of microorganisms of all different shapes and sizes, such as bacteria, viruses, and fungi. However, some of these organisms aren’t as well known.

Scientists have found that nearly all humans have mites living on their faces.

What are mites?


Mites are small creatures that are closely related to spiders and ticks. According to the University of Florida’s Entomology site, ticks and mites fall in the Arachnida class and Acarina order. A common mite that many of us are familiar with is the chigger. Mites live in a vast number of ecosystems and can be found living on nearly all mammal species.

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Your pores and hair follicles are home to some of these mites. Yes, there are tiny spider like things living in your skin. They have their own little ecosystem right on your face. Living, eating, sleeping, producing waste when they die, laying eggs, and reproducing.

Human Skin Mites


Scientists have found two types of mites living on human faces, specifically in the pores. Demodex folliculorum and Demodex brevis. The mites are microscopic and are usually located head down in the pore.
Demodex brevis
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Demodex folliculorum lives in pores near the surface of the skin. It has a “bigger, round-body” compared to D. brevis and has eight legs located on one end of its body. These mites are easily transferred between different people and have been found to be almost genetically identical in people from all over the world. They often come out of the pore and crawl around on your face at night.

Demodex brevis is a “smaller, short-bottomed” mite. These mites live in deeper pores and rarely leave their homes. They have evolved differently with different groups of people. D. brevis from someone in China can be distinguished from someone from the United States because of the genetic difference.

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These mites aren’t found all over the face. They are often found in patches around the face, such as in the eyelids, cheeks, nose, chin, and forehead. Little colonies of happy mites living peacefully in your skin.

Scientist believe the mites eat oils secreted from your pores. However, they could just as well be eating your cells. They’re just kind of chillin’ on your face. These creatures don’t like light so they become more active at night. Although this might be kind of freaky D. folliculorum and D. brevis don’t cause harm to most people.
Depiction of skin affected by Rosacea
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Can I get rid of them..?


It is thought that the presence of these mites might be the cause of Rosacea and Blepharitis. Rosacea is a “common skin disease characterized by red blotches on one’s face,” according to National Geographic. Blepharitis is inflammation of the eyelid according to Brian Chou, OD from Allaboutvision.com.

To get rid of these organisms at home Medscape.com suggests using products that contain tea tree oil, such as shampoo, face soap, and ointment. The site also recommends buying new makeup and changing sheets and getting new pillows.

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However, these mites are present in nearly all people. Scientists do not know a lot about these organisms but they believe they may be able to track human migration and divergence based on the genetic differences between mites found on different people.

Both D. folliculorum and D. brevis are found on most people. They are found in nearly all adults, in around 70% of teens, and are much less common in young children. Scientists believe we pick up these organisms from our surroundings and from other people. As we get older the more common they are. The mites are detected by isolating their DNA from oil and skin from the face.

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They aren’t hurting much. And everyone else has them so they must be cool. Love your mites. They’ve been with you forever <3

The human body is host to all sorts of organisms so you really shouldn’t be concerned with these little guys. If it makes you feel any better each mite only lives about two weeks but it does lay eggs…


I welcome my little face buddies openly. I’m totally not going to go scrub my face now…
Thanks for reading. Special thanks to all the people who keep coming back for more <3

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Friday, April 3, 2015

Coloring the World

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Basic Genes


More genetics, gotta love meiosis. As most of us know, parents pass along their genetic information to offspring. Both the mother and the father donate one set of chromosomes from a pair. We have different forms of genes, called alleles, that code for the same information. In simple cases there are only two alleles per gene and organisms usually only carry two, one from each parent. However there can be many forms of the same gene in a population.

The simplest example of allele differentiation is the famous pea plant height gene. Pea plants have two alleles for height, often denoted as “T” for the tall gene and “t” for the short gene. It was found that the tall allele covers, or obscures, the short allele whenever it is present in an organism. Alleles such as this are referred to as dominate. The short allele is only expressed when a tall allele is not present. These alleles are called recessive.

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Gregor Mendel conducted experiments with pea plants to determine this information. He created purebred plants by crossing pea plants with the tall trait many times through many generations to weed out the short alleles. He did the same process with plants that were short as he did not know the short alleles were recessive. After this he crossed pure plants with each trait.

Pea plants with two alleles for the dominate trait, TT, are called homozygous dominate and those with two recessive, tt, are called homozygous recessive. When these plants are crossed they produce offspring with Tt alleles, known as heterozygous. When two heterozygous pea plants were crossed it was found that three-fourths of the offspring were tall and one-fourth were short.

Different alleles are passed on from parent to offspring. However, there are conditions that affect the outcomes of crosses.

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Colorblindness


In humans you have to have at least one functioning color sight allele to have normal vision. The colorblindness gene is a sex linked gene, meaning it is carried on the sex chromosomes. In this case, specifically on the X. Females have two X chromosomes and males have an X and a Y. This makes males more susceptible to colorblindness. If a mother only has one good color gene, then there is a fifty-fifty shot that her son will have colorblindness.
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If a female has the gene for colorblindness it does not necessarily mean she will be colorblind. The colorblindness gene is recessive so if she has a good X without the gene, her vision will be perfectly normal. If a female is heterozygous for a sex linked gene, she is known as a carrier.

There’s the downside for males. They only have one X. So if they get a screwed up color gene, they’re going to have screwed up vision. It is not impossible for women to inherit the abnormality but it is much less common than occurrence among men.

Colorblindness has a range of severity. Cones in the eyes perceive colors. The genes in the cones contain instructions for creating different protein pigments. These pigments allow colors to be absorbed and interpreted by the brain. A variation in these genes can create different pigments, causing colors to be absorbed in an altered way.

You should see a 2 in the circle.
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Interestingly, the human eye has three color absorbing pigments in different cones. The L-cone contains pigments that absorb long wavelength light, yellows and reds. The M-cone detects midrange wavelengths, greens, and the S-cone has pigments that absorb blues.

Despite what some people think, many people who are colorblind don’t see in grey-scale. They can still see color, their eyes just have a difficult time differentiating between colors. I know a couple people who are colorblind and they often confuse shades of green and yellow, red and orange, and blue and purple. No matter how enjoyable it is to mess with people with colorblindness, you shouldn’t constantly ask them what color an object is.
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Injections in the Eye. It won’t hurt, I promise.


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Gene therapy is the future of medicine. Diseases like HIV and genetic disorders can be treated with gene therapy. Researchers have even cured colorblindness in monkeys.

According to Popular Science, Jay and Maureen Neitz of Washington University successfully cured the colorblindness of monkeys. Genes were artificially inserted into the retinas of the monkeys through surgery.

The two male squirrel monkeys that were treated had red-green colorblindness and had been colorblind since they were born, according to Nature.com. The procedure involved inserting the gene to correct the colorblindness into a virus. The virus was then “injected behind the retina” of the two monkeys. Using gene therapy, the monkeys gained the ability to create more color absorbing pigments. The monkeys were named Dalton and Sam.

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After the treatment, the monkeys could see color. Their ability to differentiate color was determined using a screen test. If the monkey touches the red colored dots, he was rewarded with grape juice.

However, researchers hope to find a way to enable this process using a noninvasive injection into the fluid in the eye. This is under development but scientists hope to carry out human trials in the next couple of years.
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Although colorblindness is not a seriously debilitating disease, finding ways to treat it could improve the lives of many people. According to the Washington University website, every 1 in 12 men and every 1 in 230 women is affected by colorblindness. Surprisingly as many as 1 in 4 women are carriers of the gene. This sort of treatment could eventually be used commonly in humans.

However, the effects of this therapy are not limited to people with colorblindness. Using this technology we could artificially end colorblindness. We would essentially be wiping out a genetic illness. The implications of this are incredible! With genetic therapy we could eventually end many genetic diseases and disorders.


Thanks for reading! I hope you see all the colors <3

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Want to find out if you’re colorblind? Take this test.