Class blog for sharing and commenting on current events in biology.

Thursday, December 19, 2013

"The Big Squeeze"


Chang, Kenneth. "The Big Squeeze." NYTimes.com. The New York Times, 16 Dec. 2013. Web. 18 Dec. 2013.

                  The article “The Big Squeeze” from the science section of the New York Times describes research that is taking place at the Carnegie Institution for Science. Russell J. Hemley and his colleagues are conducting the research on pressure and its affect on the behavior of molecules. In these experiments, they hope to discover new ways of controlling and honing in on pressure, similar to the pressure exerted in the Earth’s core. They do this by using a very highly technological machine called a diamond anvil. This anvil is composed of two cylinder plates, which press together the tips of two small diamonds. Each of these diamonds is about a quarter to a half of a carat. On the tip of one diamond, there is a notch carved for the purpose of trapping any material that is to be pressurized, or “squeezed” as the article coins it. The purpose of the other diamond tip is to press down on the material being squeezed. To pressurize gases, a box is used around the apparatus to try to squeeze as much gas as possible. The diamond anvil is quite remarkable since it has the ability to pressurize 50 million pounds per square inch of material. It can do this because pressure is simply force divided by area, and since the diamond tips are so small, the force exerted on the materials are immense. The article makes a comparison to elephants, and how the pressure the diamond makes is like taking one hundred elephants and having all of their weight push down on the point of a pencil. Needless to say, these diamond anvils are very powerful. The scientists at Carnegie have been using this machine to study different elements’ reactions to this high pressure. For example, the scientists predicted that the atoms making up these elements would remain in organized stacks, and just become closer together when pressurized. However, when they performed this experiment, they found to their surprise that the atoms lost their organization and shifted into jumbled, complex arrangements. For instance, when nitrogen was squeezed, it changed from “dumbbell-shaped pairs” to a web-like structure. Dr. Hemley describes this discovery as “a new and different periodic table.” Hydrogen turns to flat, hexagonal sheets of metal, and red oxygen when squeezed, creates red crystals. This newfound knowledge raises questions about elements not just on the Earth, but also in the entire galaxy. Scientists may have an explanation as to what Jupiter’s core is made of based off of the reactions taking place in the diamond anvil. If with enough pressure elements are completely changed, scientists have a better way of describing how planets are formed since pressure is very high in space. Ultimately, the research that is taking place at Carnegie Institution of Science is very noteworthy and could greatly progress high-pressure science.
                  Although this type of science may not seem like it affects the everyday lives of people, it in fact does. One goal of these experiments is to discover and produce new materials that will capture sunlight more effectively. By doing so, this could dramatically help the efficiency of solar cells that produce electricity or become the fuel tanks in hydrogen-powered cars. If this were to be accomplished, it would benefit the automotive industry and could convince people to switch to solar powered energy. I found this to be very interesting, how a complex machine like a diamond anvil can be used to help everyday life. Also, experiments are being conducted to see what happens when silicon and sodium are squeezed. It was found that it formed a tube-like structure and when the sodium was extracted using chemicals, it was found to absorb more photons. It may seem that this is insignificant to humanity as a whole, but by discovering this, it allows researchers to explore how to create this type of material without the diamond anvil. If they accomplish this, it could be used commercially in photovoltaic cells (cells which generate current or voltage when illuminated). In addition, testing carbon at high-pressures could offer some explanation to certain aspects of life. For example, by getting a better understanding of what happens to carbon at high-pressure levels, scientists could discover just how much carbon exists on Earth and if the formation of life could be possible in extreme environments. All in all, these discoveries could lead to a very technologically advanced world in the future.

                  Overall, I thought this article did a very good job at explaining what high-pressure science meant and the experiments involved in this type of science. It gave a lot of examples as to what happens to certain elements when pressurized and how these discoveries were significant. I also thought that by taking the time to explain what the diamond anvil was, what it was made of, and comparing it to the real world, made it easier to understand the significance of such a complex machine. However, the article became a little hard to follow once it started discussing Jupiter and the Earth’s core. If it gave a little more background on how the anvil related to this, it would have made it easier to follow. In addition, although describing the reactions of different elements was interesting, the article got a little too technical. It started going into great detail on the experiments, which was not really necessary. However, the article was written about a very interesting topic that I had never heard of before and made me realize how these new discoveries could impact our world for the better.

Toe Fossil Provides Complete Neanderthal Genome


Freddie Reichel
Core Biology Honors
Block D Odd
            Zimmer, Carl. "Toe Fossil Provides Complete Neanderthal Genome." Nytimes.com. N.p., 18 Dec. 2013. Web. 19 Dec. 2013. <http://www.nytimes.com/2013/12/19/science/toe-fossil-provides-complete-neanderthal-genome.html?ref=science>.
            From a single toe bone in a Siberian cave, scientists have sequenced the entire genome of a 130,000–year-old Neanderthal, a feat that surpasses any previous work on Neanderthal genes.  The preciseness of the newly characterized genome is equal quality to what scientists would accomplish if they were sequencing the DNA of a living person.  Now published in Nature, the new Neanderthal genome provides new novel insights and information on ancient human ancestor DNA.  Earlier in December, scientists reconstructed a small segment of genes from a fossil from Spain that was 400,000 years old, setting a record for the oldest human DNA ever discovered.  However, the Spanish DNA only demonstrated vague clues about human evolution whereas the new Neanderthal genome offers more information about previously unanswered questions.  For example, the bones of the Neanderthal were highly inbred, suggesting more interbreeding between ancient human populations than prior knowledge.  The authors of the study offered comparisons between the Neanderthal genome to modern human DNA to clearly see the lineage of the human species and what makes it so unique.  As a result, the authors of the study compiled a list of mutations that have evolved in humans over the course of 600,000 years.  The first fossils of Neanderthals were found in 1856 and scientists have been intrigued about Neanderthals ever since.  An ongoing debate has been whether Neanderthals interbred with humans or if they are completely separate species.  The fossil record of Neanderthals is mostly found in Spain and Central Asia with fossil dating back to between 200,000 years ago to about 30,000 years ago.  The scientists were able to build the genome from another sample of DNA from an 80,000-year-old finger bone from a cave called Denisova and were able to reach the surprising conclusion that the genome belonged to a separate lineage of humans that had not been discovered from the fossil record before.  The scientists named deemed these people the Denisovans.  In a comparison of the Denisovan and Neanderthal genomes to modern human DNA, Dr. Paabo concluded modern men, Neanderthals and Denisovan are all descended from a common ancestor that lived several hundred thousand years ago. The ancestors of modern humans split away to create their own lineage.  The researchers also discovered the DNA of Neanderthal and Denisovan in the genomes of modern day living humans.  It was concluded that modern humans interbred with both Neanderthals and Denisovans, which resulted in the two lineages becoming extinct.
            This is groundbreaking research.  The article helped to summarize the hundreds of thousands of years of human lineage, what we derived from and how our DNA has evolved.  Formally, there was a separate lineage of humans and the interbreeding of a Neanderthal and Denisovan is what lead to the two lineages becoming extinct.  This research helps to better understand where man came from.
            This article was written very clearly and none of the vocabulary was too sophisticated or medically oriented.  The author could have included more background information on the discoveries made prior to the completion of the Neanderthal genome and included more photographs of the fossils.

How Mosquitoes Are Drawn to Human Skin and Breath


Brennan O'Toole
Core Biology H/D Even
Current Event #2-Ms. Davies

Pittalwala, Iqbal. "How Mosquitoes Are Drawn to Human Skin and Breath." UCR Today. N.p., 5 Dec. 2013. Web. 19 Dec. 2013.

“How Mosquitoes Are Drawn to Human Skin and Breath”
In recent research published in the journal Cell, scientists pinpointed the part of the mosquito that makes them attracted to humans. Originally, these scientists from the University of California, Riverside knew that female mosquitoes are initially attracted to the exhale of CO2 by humans, but that once they get near enough to the humans, these mosquitoes change their path and travel to an area of the body exposed by skin. However, the scientists conducting this research experiment, namely Anandasankar Ray, wanted to understand why mosquitoes change their path and how they detect certain skin odors. The researchers hoped that they would be able to block these odor sensors in mosquitoes or reduce the attractiveness of human odor, effectively diminishing the presence of mosquito bites on humans. The scientists discovered that the receptor neurons in the maxillary palp of the mosquito, known as cpA, are responsible for mosquito attraction to both CO2 and skin odors, including smelly socks, worn clothes, and bedding. This was a significant and new finding because, previously, scientists had been focusing on the complex mosquito antennae rather than the simple maxillary palp organs. The fact that cpA is a receptor for both CO2 and skin odors is additionally ground-breaking because it offers understanding of this insect’s human attraction and preference, along with identifying this receptor as a target to be used to disrupt mosquito attraction behavior. The UC Riverside researchers then proceeded to chemically disrupt the activity of the cpA in the Aedes aegypti mosquito, and found that the mosquito’s attraction to foot odor in an experimental wind tunnel was significantly reduced, supporting the findings of the researchers. Next, the research team began testing chemical compounds that were a desirable scent to humans, such as mint and raspberry, safe, and inexpensive, as they would be used to either inhibit or further activate the cpA receptors in mosquitoes. They decided that ethyl pyruvate, a fruity-scented compound already approved as a flavor agent in food, could be used to reduce a mosquito’s attraction to human skin by inhibiting the cpA. Conversely, cyclopentanone, a minty-smelling fragrance agent, could be used to activate the cpA receptor and lure mosquitoes into a specific area away from humans.
The isolation of the skin and CO2 receptors in the maxillary palp and the discovery of two compounds that could both inhibit and activate cpA will have positive effects on many areas of the world. Female mosquitoes have the capability of transmitting deadly diseases, such as malaria, dengue fever, the West Nile virus, and filariasis to human populations, especially in South America, the Caribbean, Asia, and Africa. Compounds that block the cpA, such as ethyl pyruvate, will mask humans from mosquitoes and the harmful diseases they carry, and can be applied safely to human skin. On the other hand, compounds like cyclopentanone, which activates cpA, can be used to lure mosquitoes into traps and protect larger areas and a greater number of people at a time. This research was especially significant for people living in poorer countries because it offers more affordable solutions, in the form of compounds, rather than the former expensive solution of burning fuel to generate CO2 as a mosquito trap.
This article was able to concisely express the large significance that the discovery of the cpA receptor as a receptor for both CO2 and human skin odor will have on the human population, specifically for those living in continents where mosquitoes transmit deadly diseases. As a reader, this article, although it contained many scientific terms, was very easy to follow with the way that it went into thorough explanation on why the location of the dual CO2 and skin receptor will have large effects on future preventative action against mosquitoes. This article was also enjoyable to read because it included both the discovery of the cpA receptor, along with the two chemical compounds that were chosen as a result of this discovery to combat mosquitoes. Finally, this article was engaging because it addressed a very relatable issue, the presence of mosquitoes and the diseases they carry, which affects the global human population. If there was one thing to critique about this article, it would probably be the lack of explanation on how the researchers discovered that the cpA receptor was a dual-receptor for CO2 and skin odor, and how they located it within the maxillary palp. Other than that, the article succeeded in presenting a biological discovery that will potentially improve the lives of over 500 million people in an easily understood manner.



Tuesday, December 17, 2013

humanities poster


Emme Kerj
Poster was made by Nick Sutherland, year 10
                The humanities poster that Nick made was regarding whether a teacher’s ability of teaching affects the student or not. It also compared the different ways of teaching and the different types of teachers that are hired based on the school’s desired goals for the students. In his poster/presentation he discusses the different policies for controlling teaching methods and whether these policies have limitations or not. One teaching method that he explains is the “no child left behind”, which generally states that all students are tested by mandatory standardized tests and that the teacher is hired based on qualifications that is bachelors degree or supplemental teachers exam. The other method is “race to the top” which goal was that all students must be college ready by the end of high school and the teacher was hired based on qualifications and effectiveness regarding their performance in a classroom environment. It explains that statistics have proven that proof curriculums and standardized pedagogy are ineffective and that the education should be more individualized based on the student’s learning abilities. He explains what role a teacher has in a classroom and furthers the subject by saying that although a teacher is supposed to teach the class as a whole, they should be helping student’s on an individual level too in order to make sure that everyone learns the same knowledge but based on their own abilities.
                Overall, the presentation and poster did a great job explaining the subject and emphasizing the importance of individualized learning. One thing that he could have explained further was what affect teacher’s have on their students as a whole and in the long run. 

Monday, December 16, 2013

The Importance of Vitamins

Biology
Caroline Schetlick

Importance of Vitamins

            Our health depends significantly on vitamins. We can either intake vitamins, or produce them with our own bodies. Our ancestors used to be able to make their own vitamins, such as Vitamin C. However, we have evolved out of making our own vitamins. Our ancestors did not necessarily need to produce vitamins for themselves for they ate a good supply of fruit. On the other hand, the rise of agriculture led to the production of more starches like wheat and corn. These starches lack a sufficient supply of vitamins, which had put us in risk of disease. In the mid-1800s, processed rice, or white rice, became very popular with the usages of the new steam powered mills. The process took away the outer layer of the rice, which was rich in vitamins. The rise of white rice led to the rise of the disease called beriberi. This disease causes people to lose feeling in their legs and have trouble walking. A scientist named Christian Eijkman discovered that chickens could also develop this disease, and studied the disease in the 1880s. As a result, he found that once the birds stopped eating the processed rice, they quickly recovered. Researchers soon found that the vitamin in the outer layer of rice is Vitamin B1, or thiamine. On another note, in the United States alone, the annual sales of multivitamin and mineral supplements total in $12.5 billion. Although a balanced diet will provide a good supply of vitamins, extra vitamins don’t necessarily add to the benefits. In a 2013 review, a study proved that vitamin supplements do not prevent cardiovascular disease. Studies also showed that pregnant women benefit from Vitamin B9, or folic acid. Although vitamin supplements don’t do too well in countries that suffer from malnutrition, vitamin deficiency remains a threat. For instance, Vitamin A deficiency leads to blindness, causes the eye to lose its light sensing molecules, and it weakens the defense against infections. How can we prevent this? Simply intake a variety of foods in your diet.
            This is very relevant to our world, and the lives of many. Lots of people are affected negatively from vitamin deficiency. Scientists are now finding cures for certain diseases, such as malaria, using vitamins. Scientists are developing compounds that are essentially mimicking the functions of vitamins. When dealing with the disease malaria, single-celled parasites called Plasmodiums invade red blood cells. To prevent this from happening, the mimicked vitamins kill the Plasmodium through trickery, because these mimicked vitamins are actually incapable of carrying out the jobs of normal vitamins. This is relevant because it will save lives. It is still in the early process, however, it will be a major break through if this system continues to succeed. Vitamins are vitally important to our daily health, and we should be taking in fair amounts of Vitamin A, B (thiamine), C (fruit), and D (sunlight) in our diet daily in order to live a healthy life.
            This article was written very well, and was loaded with lots of good information. However, there tended to be a little too much information in some areas that were besides the point at hand. This made it a little more difficult to read. Overall, there is little criticism, for I have learned a lot about my health, and the health of others from reading this article.


Works Cited

Zimmer, Carl. "Learning From the History of Vitamins." The New York Times - Breaking News, World News & Multimedia. N.p., 12 Dec. 2013. Web. 14 Dec. 2013. <http://www.nytimes.com/2013/12/12/science/learning-from-the-history-of-vitamins.html?ref=science>.
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