CSB #8: Blood Pressure and Pulse Rate Experiment by Madhu and Angie

Authors: Angeline Pan and Madhu Nori

While exercising, the heart needs to pump blood faster and in larger amounts to all of your body because you are using up your oxygenated blood quickly. After exercising, have you ever felt a fast throbbing sensation throughout your body and a higher pulse? This is because your heart has been doing its job. However, when sleeping or resting, your body does not have to work as hard to get blood to the rest of your body.

In this experiment, Madhu and Angeline tested what would happen to our blood pressure and pulse if our physical position/state was altered. We tried 3 different positions and one state of exercise: lying down, sitting on a chair, standing, and after doing 40 jumping jacks.We wanted to see how blood pressure changes with each position/state and determine why this happens. We hypothesized that if a person were to lie down, sit, stand, and do 40 jumping jacks, then the blood pressure would be lowest while lying down and gradually increase to the highest blood pressure after exercising.

During this experiment, we used the logger pro application on our laptop to connect the blood pressure sensor to collect the data. First, the test subject, Angeline, lay down for five minutes and while Madhu wrapped the blood pressure sensor around her arm and recorded the blood pressure and pulse. We then proceeded to repeat this process three more times, but for sitting down, standing, and right after exercising.

Awkwardly lying down on the ground

Sitting

Standing up!

Working hard, AKA doing jumping jacks ;D

We found that our hypothesis was correct: run 1 (lying down) resulted in 109/63 & a pulse of 67, run 2 (sitting) resulted in 112/71 & a pulse of 70, run 3 (standing) resulted in 124/78 & a pulse of 83, and lastly, run 4 (after 40 jumping jacks) resulted in 136/85 & a pulse of 108. There is not that large of a difference in the blood pressure, however there is a slightly larger difference between the pulse rates.

Overall, our experimental hypothesis was supported by our data. We think this ordering is correct because lying down requires the least energy, sitting requires a little more, standing requires even more, and doing jumping jacks is the most tiring. Because the muscles of the body must function more as the body requires more energy, blood must flow faster. Thus, due to the lack of adequate amount of blood, the heart is signaled to pump more and support the muscles. Furthermore, as the heart pulse rate increased, pressure would increase likewise because more liquid is forced through the vessels at a higher speed.

CSB #7: Densest Planet Discovered by Madhu Nori

The Canadian Space Telescope, MOST, has discovered "the densest solid planet known anywhere," as well as "the hottest known rocky world." The "hot super-Earth," which orbits a distant star called the 55 Cancri A, is part of a four-planet system 42 light-years away. Researchers say that the planet, 55 Cancri e, orbits its star in an amazingly short 17 hours and 41 minutes, which means that it is actually 20 times closer to its sun than we thought when we discovered the planet in 2005. We also measured the planet wrong: the diameter is only 60% larger than Earth's, yet it is 8.3 times more massive.

"With a year that lasts less than 18 hours, surface temperatures reaching 2,700 degrees Celsius [4,892 degrees Fahrenheit], and having the density of lead, this is hands down the most exotic world we have ever seen," said Jaymie Matthews, an astronomer at the University of British Columbia in Canada. Also, their sun would appear 60 times bigger and shine 3600 times brighter when standing on 55 Cancri e. Given its size and mass, Matthews said, "You can liken 55 Cancri e to a Sumo wrestler in a supermodel body."

Because the planet is not that far from Earth (it's star is visible to the naked eye on Earth), 55 Cancri e could prove to be a "unique laboratory to investigate the story of how planets form and evolve," researchers at the University of British Columbia said. What might we learn from this strange and exotic planet? Because there has been confusion on multiple occasions of the measurements of this planet, is there a possibility that we could be wrong again? Could the discoveries made from this planet support or contradict the Big Bang Theory?

Citations:

"Densest 'super Earth' planet discovered." Science Online. Facts On File, Inc. Web. 9 May 2011. .

CSB #6: Algae Can Be Used to Clean Up Nuclear Waste by Madhu Nori

Researchers claim that common fresh water algae can be used to isolate radioactive strontium from water and can therefore help to clean up nuclear waste. Scientists at Northwestern University and Argonne National Laboratory have been working to find out how this may be done.

Northwestern reported that Strontium 90 is a dangerous fission material that is created within a nuclear reactor and is so common in nuclear waste, that it is present in all the 80 million gallons of radioactive waste-sludge stored in the United States. Strontium 90, which has a half-life of 30 years, is very similar to calcium chemically, and in this way, it is drawn to bone, creating a high cancer risk from exposure. One of the bright green algae often seen in ponds called Closterium moniliferum can isolate and then form a compound with strontium in the form of barium-strontium-sulfate crystals.

This knowledge could lead to direct bioremediation (the use of naturally occurring or deliberately introduced organisms to consume or break down environmental pollutants so as to clean up a polluted site) of waste or accidental spills. "Nuclear waste cleanup is a problem we have to solve," senior researcher Derk Joester, who experienced Chernobyl's radioactive fallout when he was a teenager living in southern Germany, said.

How is it possible for a simple and common plant to sequester strontium in the form of barium-strontium-sulfate crystals? How exactly will the clean-up of nuclear waste by algae be implemented? Are there any problems with this method?

Source:

"Scientists eye algae for nuclear cleanup." Science Online. Facts On File, Inc. Web. 7 Apr. 2011. .

CSB #5: Breakthroughs in Tissue Regeneration by Madhu Nori

At companies such as Organogenesis Inc. and ReNeuron, researchers are looking into the field of regenerative medicine, which is the science of growing new human body parts. The typical strategy for regeneration would be through stem cells, because, as they are not set/destined to become one type of cell yet, they have the ability to set apart and mature into many different cell types, including cell types that the adult body cannot normally regenerate. It's a simple enough idea, but it's difficult to implement because it is politically opposed, as it could require the use of embryonic stem cells, which may strike some people as unethical. Also, there would be countless technical challenges. However, so far, stem cells have only been used for bone marrow transplant patients, and more widespread stem cell therapies seem to be possible in the far future. With stem cell therapy, doctors would prescribe a potion that lets patients grow their own stem cells instead of giving a patient a sprinkling of stem cells.

Kostandin V. Pajcini and Jason H. Pomerantz in the Blau lab at Stanford University are examining how certain fish and amphibians can regrow tissue in their muscles, eyes, and hearts, while mammals cannot. Pajcini's team began by noticing an evolutionary pattern: basic organisms are good at growing new muscles, but complex vertebrates are bad at it. The human body cannot grow new skeletal muscles for two reasons. First, skeletal muscles are stuck in interphase, so mitosis does not start. Second, skeletal muscle cells have a strange characteristic that makes mitosis impossible. Pajcini and colleagues hypothesized that the key to regeneration is still carried within the mammalian genome, it's just being blocked by genes that mammals have, and amphibians do not. The ability to regenerate muscle tissue is obviously a great survival skill, so it is perplexing that evolution has subdued it.Studies on newts provide the answer: research shows that genes involved in newt tissue regeneration are also genes involved with how human cancer is caused. An example is the retinoblastoma gene, or Rb. The gene named because of the retinal cancer that results if it is mutated in humans. But in newts, deactivating Rb's protein product gives the signal that it is time to sprout a new muscle.

Pajcini's team looked to nature to try to produce a mammalian version of the newt's awesome limb-sprouting capability. But looking for inspiration in nature is not the only way to get results. Many other methods are being researched currently, such as "reprogramming" mature cells that didn't come from embryos or immature tissue to become stem cells, adopt a different job/function, and "turn off" certain genes that may prove to be harmful or unnecessary in that cell. By the time these methods are safely applied to humans, our stem cell therapies may be advanced enough to safely help people with a variety of conditions, and growing our own cells may no longer be necessary.What are some of the hurdles that need to be overcome before such research findings can be translated into workable therapies? Isn't it always good to have alternative methods if one method proves intractable? In the far future, will we be growing new cells and muscle tissues on our own?

Citations:

Tanenbaum, Jessica. "Breakthroughs in Tissue Regeneration." Science Online. Facts On File, Inc. Web. 7 Mar. 2011. .

CSB #4: Dark Worlds

Definitions:

Anomaly: Something that deviates from the norm

Dark Matter: Matter that is thought to exist based on gravitational effects on visible objects and radiation. It is hypothesized to account for discrepancies between measurements of galaxies and the universe.

Summary:

Just as Neptune was discovered by Johann Gottfried Galle after receiving a letter from Urbain le Verrier suggesting an unknown object whose gravitational pull was affecting Uranus' orbit, astronomers observe anomalous cosmic motions, which lead them to search for the new matter that is the cause. Once Neptune was discovered, we found that stars and galaxies do not move in ways they should. From the anomalies we see, we can come up with some theories. For one, we can deduce the existence of dark matter, which seems to be a sea of invisible particles that fill space unevenly, and dark energy, which is spread out though space uniformly and "acts as if it is woven into the fabric of space itself." Dark matter outweighs normal matter by 6 to 1. Scientists are increasingly considering the possibility that another universe is hidden by dark matter, in which there are identical hidden galaxies, planets, people, etc. Because of the large amount of dark matter compared to ordinary matter, astronomers assume that hidden galaxies are embedded in giant balls or "halos" of dark matter, and that for this dark matter to be unseen and undetectable, it must consist of particle that rarely interact with ordinary matter or even with one another. Force-carrying particles, known as W and Z particles that were discovered in the 1980s, display properties that hint at the existence of dark matter. For example, they have a very high mass, which suggests that some matter is acting on them. Other particles that closely resemble our thoughts of dark matter particles are WIMPs (weakly interacting massive particles), which have a high mass and only interact by means of a weak nuclear force, just as dark matter particles do. Scientists have come to think that dark matter is made up of WIMPs, which do not interact with the visible world. However, scientists also ponder: "might dark matter in fact have a rich inner life?" Dark matter could be interacting through many different forces, including a form of light to which our eyes are completely blind.

Discussion:

I think it's fascinating how our universe is filled unevenly with dark matter. It causes discrepancies between measurements of galaxies and the universe, while dark energy is a permanent part of the universe. It's truly intriguing how there could be other "hidden" galaxies and planets. There can even be the possibility of a hidden planet that is identical to ours, in which there are similar forms of life. Reading this article really made me want to find out what exactly dark matter is, and what role it plays in our universe.

Questions:

• Due to the discrepancies between measurements of galaxies and the universe, could it be possible that our universe is truly not as big or small as we think it to be?
• Could there really be other "hidden" planets with forms of life on them? How would they thrive?
• How did dark matter really come to be, and what is it made of?

Sources:

Feng, Jonathan, and Mark Trodden. "Dark Worlds." Science Reference Center. EBSCO
Host, Nov. 2010. Web. 8 Jan. 2011. .

CSB #3 - Controlling the Brain with Light (Madhu Nori)

Definitions:

• Optogenetics: A combination of optical and genetic techniques to probe neural circuits and brain cells with, or a research procedure that inserts opsin genes into brain cells and uses flashing light to stimulate responses in specific neurons
• Neuroscience: The scientific study of the nervous system

Summary:

Because of our limited insight into the causes of psychiatric diseases, we cannot search for cures easily. The mammalian brain is very complex, and therefore it is difficult to really grasp what the brain is doing: “It is an intricate system in which tens of billions of intertwined neurons--with multitudinous distinct characteristics and wiring patterns--exchange precisely timed, millisecond-scale electrical signals and a rich diversity of biochemical messengers.” Optogenetics allows researchers to probe the brain and observe how the nervous system works in great detail. In 1979, Nobel laureate Francis Crick suggested that the major challenge facing neuroscience was the need to control one type of cell in the brain while leaving others unaltered. He speculated that that certain cells could be made to respond to light. Biologists found that in response to light, some microorganisms directed a flow of electric charge across their membranes. These proteins used in the microorganisms, produced by a set of "opsin" genes, help extract energy and information from light in the microbes' environments. So, by inserting opsin genes into the cells of the brain, scientists can now use flashes of light to trigger firing by specific neurons on command. This new technology allows researchers to conduct extremely precise, specific-cell-type targeted experiments in the brains of living animals, which other methods do not allow. And although optogenetics is relatively new, it is already yielding useful insights into neuroscience involving some psychiatric conditions.

Discussion:

• I think that the brain is incredibly complex, and therefore, it’s amazing that we can do precise experiments on it and from that find the causes of psychiatric diseases.

• If this new technology advances even further and proves to be effective, then we can learn so much more about our nervous systems and how we process our thoughts so fast.

Questions:

• How exactly do they use this technology on humans if they are alive? Does it involve getting inside the body or just manipulating it from the outside?

• How long will it take to find more about the nervous system in order to speed up the process of finding cures for psychological diseases such as Alzheimer’s and schizophrenia.

Sources:

Deisseroth, Karl. "Controlling the Brain with Light." EBSCO Host. ESBCO, Nov.
2010. Web. 18 Nov. 2010.
detail?vid=6&hid=8&sid=2d7d9a4e-0ba0-4043-8e35-15373e97a119%40sessionmgr4&bdata=J
nNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=sch&AN=54477955>.

CSB#2: When the Sea Saved Humanity - Madhu Nori

Definitions:

• MIS6: Marine Isotope Stage 6 - A period 195,000 years ago when the earth's conditions began to deteriorate and the planet went into a glacial stage. This period lasted until about 123,000 years ago.
• Paleoanthropologist: Someone who studies a branch of anthropology, or human kind and their evolution, concerned with fossil hominids.
• Homo Sapiens: The primate species to which modern humans belong.

Summary:

• At some point between 195,000 and 123,000 years ago, the population size of Homo sapiens plummeted perilously-from more than 10,000 breeding individuals to just hundreds, thanks to cold, dry climate conditions that left much of our ancestors' African homeland uninhabitable. The harsh climate conditions nearly extinguished our species.
• Everyone alive today is descended from a group of people from a single region who survived this catastrophe.
• The southern coast of Africa would have been one of the few spots where humans could survive during this climate crisis, because it harbors an abundance of shellfish and edible plants.
• This region is called Pinnacle Point, a promontory near the town of Mossel Bay that juts into the Indian Ocean
• Shellfish, which are rich in protein, are thought to have aided survival of the Pinnacle Point population because they abound year-round in the rocky intertidal zone along the southern coast of Africa. Brown mussels have turned up in even the earliest levels of PP13B, dating to 164,000 years ago, revealing that humans began exploiting marine resources earlier than previously thought.
• Excavations of a series of sites in Pinnacle Point, Africa, such as PP13B and caves 5-6, have recovered items left behind by what may have been that progenitor population.
• Finding archaeological sites dating to glacial stage 6 required searching for shelters that were close enough to the sea to allow relatively easy access to shellfish yet elevated enough that their ancient remains would not have washed away when the sea level rose 123,000 years ago.
• The results from these excavations highly prove that the human population did, in fact have a major drop about 195,000 years ago.
• The discoveries confirm the idea that advanced cognitive thinking evolved earlier than previously thought, and may have played a key role in the survival of homo sapiens during tough times.

Discussion:

• I think that it's really cool how we are all descended from that tiny group of homo sapiens that survived the MIS6.
• Basically, this article is telling us that we all originated in Africa. This intrigues me as Africans have very different facial features compared to Europeans or Asians, for example.
• It's interesting that, even 195,000 years ago, our ancestors were actually smart enough to find new habitats in which they could survive. They also made stone tools and lived in caves.
• It's scary that the homo sapiens species almost completely died off because of the MIS6. if they had actually died off, then we wouldn't be here, dominating the earth. This just shows how bad the consequences of global warming could be for us humans.

Questions:

• How were they able to migrate and successfully find new habitable land in time before they died out?
• How is it possible that a global population approaching 7 billion is all descended from a group of only a few hundred people?

Sources:

• Marean, Curtis W. "When the Sea Saved Humanity." EBSCO Host. Scientific
  American, Aug. 2010. Web. 14 Oct. 2010. .