28 | April | 2010 | MU Science Blog

A Different Kind of Canary April 28, 2010

Posted by ecogeeko10 in Ecology, Environment/Conservation, Genetics.
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timber rattlesnake

What’s the difference between a canary and a timber rattlesnake? Not much if you’re a conservation biologist who is examining the effects of habitat fragm entation on bi odi ver sity.

A recent study by a group of Cornell University researchers shows that even some of the simplest forms of human disturbances are having large impacts on biodiversity. Timber rattlesnakes in particular, have been a major focus in the northeastern region of the U.S. because these scientists have been able to utilize fine-scale molecular genetics and micr osatell ite markers to track the rattlesnake populations. They are finding that fragmentation caused by small scale road development is having a more than noticeable effect on the genetic diversity of these snakes. For this reason, one could compare the rattlesnakes in this study to canaries in a coal mine.

Of the 500 individual snakes taken from four separate regions and 19 hibernacula, none of the genetic clusters spanned either major or minor roads. This greatly proves to the non-believers that roads are indeed significant barriers that limit the dispersal and other natural processes necessary for species survival. Don’t assume, though, that this is only affecting the timber rattlesnake populations. Countless other studies show that habitat fragmentation is causing the demise of many of our planet’s species. Nevertheless, this study is unique because it only deals with roads. When people think of habitat fragmentation, they usually think of rainforest deforestation or mountaintop removal—they don’t always realize that something as common as a road can be quite detrimental to a species. Hopefully this study will help us to learn to notice the “smaller things” that can hurt the environment and maybe we can be inspired to do something about it.

The Song of the Dodo

Before I end this blog, I just wanted to mention that there are a few books that I hope to read this summer, including a book called The Song of the Dodo: Island Biogeography in the Age of Extinction, by David Quamm en. This greatly relates to this recent study that was done with timber rattlesnakes because it talks about habitat fragmentation and its implications on biodiversity. I am hoping to learn something from this book and I was also thinking that it would be cool if others read it too. Perhaps we could even discuss our thought of the book at the end of the summer (via the MU Blog)! I am also willing to take other book suggestions—it could be like an “online summer book club” or something. Let me know what you think!

Pollution is Good? April 28, 2010

Posted by Colleen in Climate Change, Environment/Conservation, Health, Policy.
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Marian University celebrated Earth Week last week (April 19th-22nd). We even hosted an outdoor movie and taught everyone the importance of recycling! That same week the EPA put out a report saying that air pollution has dramatically reduced over the past twenty years. To me, that seems like a really good thing, but according to a recent NPR story, clean air could actually be intensifying global warming.

Shocked? Me too.

But, according to science writer Eli Kintisch, this could be the case.

Why is this so?

Well, there are two kinds of air pollutants: aerosols and greenhouse gases. Greenhouse gases warm the planet, which we are well aware of, but recently scientists have discovered that aerosols actually have a temperature maintaining effect for the earth. Apparently if all man-made air pollution was stopped, global warming could be sped up by as much as a degree Fahrenheit. While greenhouse gases absorb heat, adding to global warming, aerosols actually reflect sunlight away from the earth causing the earth to cool down rather than heat up. By cleaning the air, we’re taking away this stuff away, perhaps adding to the increase in the global temperature. These pollutants still cause health problems, like asthma and respiratory disease, so letting them stay in the atmosphere isn’t necessarily the answer. The scary thing is that we don’t know how much these cooling effects have slowed down global warming. If it’s a lot, then taking the aerosols away could cause a huge problem. This would mean that we’ve been causing a larger warming effect than we originally thought. If not, then it may not be as much of a concern.

One idea that has come about from this knowledge is to use geothermal engineering to fix the problem caused by removing these cooling pollutants. What we would do is inject new pollutants into the clouds, allowing for the cooling to occur. Theses sulfur aerosols are distributed naturally during volcanic eruptions, such as the one we’ve been seeing in Iceland. Volcanoes, when they erupt, put out a lot of sulfur aerosols into the stratosphere and can cause cooling to happen. The idea is that if there is a natural emergency in the future caused by the warming, it might be possible to slow or stop the warming by mimicking the volcanoes and injecting these aerosols into the stratosphere.

Crazy huh?

To hear the whole story, click here.

Is it a good or bad time for students who dream of going to medical school? April 28, 2010

Posted by Jill in Health, Medicine, Policy.
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With the passing of the 2010 healthcare bill, many more Americans will have access to healthcare. Prior to the bill many people were unable to afford the astronomical costs of seeing a doctor regularly, not to mention paying for surgery or major medical procedures without insurance.

For many aspiring medical students, this is great!

There will be a need for more physicians to accommodate the number of patients that will be receiving this affordable healthcare. The need for primary care physicians is expected to skyrocket based off of the sheer number of physicians needed to meet the demand of a growing number of potential patients.

Where do we get these primary care physicians?

The problem that arises with the growing need of primary care physicians is that so many medical school students want to specialize in a particular field of medicine such as surgery or cardiology because they have a particular passion for their interest. Also, physicians that specialize have a significantly higher income than those who are primary care physicians. Today, the United States is already shorthanded when it comes to primary care physicians and it will be difficult to meet the needs of the growing number of patients as they receive greater healthcare benefits.

There are some medical schools in the United States such as the University of Colorado School of Medicine and Rocky Vista University College of Osteopathic Medicine that are responding to this call for primary care physicians by encouraging their students to get into primary-care medicine, such as pediatrics, OB-GYN, internal medicine, and family practice. With the annually increasing cost of medical school, it is difficult to steer students away from high-paying specialties. The University of Colorado, along with other medical schools, has started a “pipeline” program which allows promising high school students direct admission to medical school following college and help them with their debt, so as to encourage students to defer the cost of medical school. Also, increasing the size of medical school classes has helped in graduating more physicians per year, which will help in meeting the soon high demands of patient care.

How do we encourage students to be primary care physicians?

Because the cost of medical school is so high, more programs need to be implemented to help medical students pay for their medical school and not have to rely on specializing in order to repay med school loans. The benefit of going to medical school at this point is that the job market isn’t saturated in the field for primary care physicians, but the question remains, who is willing to take the pay cut and potentially lengthen the amount of time it will take to pay off the debts of medical school?

If our government is willing to provide insurance to those who could not before afford it, should our government also be responsible for helping medical students with their tuition costs in order to provide these new patients with the proper healthcare that our country is known for as well as the manpower to manage the number of new insured patients?

A Second “Lab Rat” has its Genome Mapped April 28, 2010

Posted by ecogeeko10 in Behavior, Biology, Evolution, Genetics, Health, Neuroscience, Physiology.
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Many behavioral ecologists, geneticists, physiologists, etc. are familiar with the zebra finch (Taeniopygia guttata). In fact, many have considered it to be the avian version of the white lab rat. Because of this, these researchers should be excited to hear that scientists have just recently decoded the zebra finch’s genome.

A genome to explore behavior

The zebra finch isn’t the only bird to have its genome mapped (the chicken was completed first) and it’s only about one-third the size of the human genome. However, this was a unique find because it will greatly help behavioral ecologists to understand the underlying mechanisms that help baby songbirds learn how to sing from their parents. This isn’t something that could have been done with the chicken genome because chickens don’t learn how to “cluck” from their parents—they just do it. Zebra finches, on the other hand, are similar to humans because human children also learn how to speak from their parents.

The zebra finch genome gives us the opportunity to explore the influence of genetics on language development.

Researchers are already analyzing the genome and they are finding that a good portion of the bird’s DNA is actively participating in the hearing and singing of songs. What’s more, these short simple songs are rooted in a great deal of genetic complexity. To date, it has been understood that the very act of singing and hearing songs activates large, complex gene networks in the bird’s brain. However, the current genomic research is revealing there to be many more participating genes than once thought. Right now it seems that there may be approximately 800 total genes that are active in this process!

Genes not acting as genes

New evidence is also showing that many of the activated genes aren’t acting like genes in the traditional sense. Rather than coding for proteins, the DNA from these genes is transcribed into short stretches of non-coding RNA that control the expression of other genes involved in the zebra finch’s vocal communication. Since non-coding RNAs are very influential in the developmental processes in animals and since they are thought to be instrumental in the evolution of higher organisms, the vocal learning that is found in the higher organisms may use non-coding RNAs as their driving force.

The evolution of language

It is also worth noting that when comparing the newly mapped zebra finch genome with the chicken genome, there seems to be some obvious differences that may point towards the evolutionary pathway that gave rise to birds that are capable of vocal learning. For instance, the evolution of the ion channel genes—which are important players in behavior and neurological function—in the zebra finch brain were greatly accelerated; the expression of the male sex chromosome genes seems to have been modified; and the production of new variants of neurobiologically important genes have taken place. It is amazing to see how much has learned in such a short period of time!

From birds to humans

It took the combined effort of more than 20 institutions to map out the genome of this song bird and now everyone has the opportunity to reap the benefits from this work. The newly gathered information should prove to be instrumental in helping us to better understand how humans learn language and perhaps it will help neuroscientists to identify the genetic and molecular causes of certain speech disorders that are associated with various illnesses such as Parkinson’s disease, stroke, autism, etc. With the parrot genome scheduled to be completed by the end of this year, who knows what all we can learn about our little feathered friends and even ourselves!

Will fruits and vegetables really prevent disease? April 28, 2010

Posted by zach in Genetics, Health, Medicine, Nutrition.
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Has you mother ever told you,” You are what you eat?”

With new discoveries being made daily, there is emerging research showing the interaction between environmental and dietary influences in the development of diseases such as cancer.

A new study published in the Journal of the National Cancer Institute shows there is a weak relationship between high fruit and vegetable intake and your overall cancer risk. During the 1990’s it was widely thought that fruits and vegetables could prevent cancer and other diseases. To date there is a lack of studies that could conclusively prove the claim about fruits and vegetables preventing cancer on a large-scale. But just because they can’t prove it on a large-scale isn’t to say that you should stop eating your fruits and vegetables and go on an all fast food diet.

On a smaller scale it has been found that a substance found in vegetables can combat cancer epigenetically.

Epigenetics is the study of how gene expression can be altered without changing the underlying DNA sequence, this can be done with methyl and acetyl groups. Enzymes have been found that can effect how the chromatin is condensed. When the chromatin is in an extremely condensed state transcription is limited because the polymerases struggle to attach to the DNA template.

Histones acetyltransferaes (HATs) and histone deacetylases (HDACs) are used to add and remove an acetyl groups, these acetyl groups regulate the biochemical structure of the DNA that regulates gene expression. Three key dietary components that have been shown to affect HDAC and HAT activity 1) butyrate, which is formed by fermentation of dietary fiber in the colon, 2) diallyl disulfide is found in garlic and allium (onion family) vegetables, and 3) sulforaphane, which is found in coniferous vegetables. All three of these substances have been shown to prevent cancer in clinical and preclinical trails by inhibiting HDAC enzymes. Even though fruits and vegetable have yet been linked to preventing cancer on a large-scale, certain substances found in vegetables have been found to prevent cancer. Maybe it is not enough just to eat the fruits and vegetables, researchers may have to isolate these cancer fighting compounds in order to use all of natures cancer fighting power. Even though a strong positive correlation between cancer and fruits and vegetables is yet to be found, you may want to continue to eat healthy. From researching how diet can affect epigenetics there is a clear relationship between cancer, epigenetics, fruits, and vegetables. Researchers are just going to have to continue to look for ways to harness some of the anticancer properties of both fruits and vegetables.