Thursday, November 29, 2012

6th Period - Case Study Summary

Respond to this with a comment that contains your summary paragraph.  Do not duplicate a case study that someone else in your class has already done.  Make sure to comment on one other person's summary. 

44 comments:

  1. A Devil of a Disease
    I said i would be first. A major reason that the Devil Facial Tumor Disease has been so successful in eradicating 70% of the Tasmanian Devil population is the generations of inbreeding resulting from the species being protected. The inbreeding does not allow for a great deal of genetic diversity and this makes them less capable of evolving resistant to the disease. The karyotyping of the Devils made it clear that the problem was related to an inversion of a chromosome. Scientists hypothesized that it was a naturally transmissible cancer because it primarily occurred on the face and that is where Devils have the most contact with others. Seeing the similarity of this to cancer in dogs solidified the scientists belief.The scientists could test whether it was truly a venereal disease by placing infected and healthy Devils together and seeing if after contact the cancer transferred. If it did it could be concluded that it was a venereal disease. It can be concluded from this experiment that the Devils can be saved from extinction if a healthy population is isolated because the disease transfers through contact with an infected devil.

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    1. Interesting topic Abhi. It was very thorough. I've never heard of the Devil Facial Tumor Disease until now....It's saddening that DFTD threatens the extinction of Tasmanian devils. I was so intrigued that I decided to read the DFTD case study. As i was skimming through the notes, I found certain statements to be fascinating.For example, "Although Tasmanian devils appear to be genetically similar, it is possible that the cancerous tissues are not recognized as foreign tissues and therefore are not eliminated." For some reason, i found that statement fascinating..Anyways, naturally transmissible cancer is rare and only having been reported to occur in dogs. As you stated above, the similarity between the cancer found in dogs and Tasmanian devils lead the scientists to solidify their belief. It is unfortunate that there is no cure for this disease.

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    2. Abhi this is mindblowing and earth shattering. I had no idea that the Tasmanian Devils were under such duress. We need to inform PETA. But in all seriousness, this was a very interesting topic and I had never even heard of DFTG beofre today. Also they fact that the body of a Tasmanian devil can't recognize foreign tissue as cancer is scary, what if DFTD made a mutation and jumped over to humans?

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    3. I made a promise to use my reply on the first comment and surprisingly it just happened to be you, Abhi. Anyways, the topic is very interesting because 1) I have never heard of Devil Facial Tumor Disease and 2) the species have not grown resistant to the disease. Since the hypothesis has been deemed true, it would not be surprising to actually see a migration of the Tasmanian Devils to a safer environment. Sameer, stop predicting such terrible mutations. lol

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    4. This isn't my real comment, but wasn't this mentioned in some of our summer reading?

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  2. I read “A Case Study of Memory Loss in Mice” by Michael S. Hudecki.
    Research has revealed that about 50 percent of Alzheimer’s disease is caused by a faulty gene. This apparently affects the expression of beta-amyloid, a specific brain protein. Alzheimer disease causes the gradual deterioration of cognitive function, including severe memory loss. The accumulation of amyloid protein within the brain is likely a contributing cause of Alzheimer’s disease. This case investigates the scientific process involved in implementing an animal model in the study of Alzheimer’s disease. The brains of “trained” mice were injected with beta-amyloid fragments. This caused them to forget their tasks. The “trained” mice are thought to be appropriate test subjects for the amyloid protein injections. These mice would be tested again using the maze/reward configuration. The ability of the injected mice to navigate the maze successfully will determine the effect of amyloid on memory. “Initially, Mice are trained in a box with an electrified floor that delivers a shock if the mice do not actuate a “reward lever” in a specified time. With repeated training sessions, the mice quickly “learn” to travel the length of the box and avoid getting shocked. Subsequently, the “trained” mice are subjected to injections of amyloid protein fragments and then re-tested to determine if they are able against time to navigate the box without being shocked.” If amyloid is one of the causes of Alzheimer’s, then why can’t the accumulation of it be diminished through a vaccine? Currently, vaccines are being tested for effectiveness and safety on experimental mice. However, there is uncertainty as to exactly which form or forms of the protein are toxic to neurons.

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    1. Megan, it seems as though we only connect memory loss with humans and fail to realize that other mammals contain the potential to have this disease. Beta-amyloid accumulation is said to be one of the main causes of Alzheimer's disease. My question is, what causes this gene to be expressed more frequently as age increases? Is there any direct relationship between neuron activity and the expression of this gene?

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  3. Megan this was very educational to me. I did not even know that memory loss could affect mice. The maze test on mice seems like the perfect way to test memory loss in mice. The expression of beta-amyloid fragments seems like the cause of Alzheimer's. The fact that merely introducing beta-amyloid fragments to mice without any sort of change to mice shows that beta-amyloid fragments can affect organisms at any time during the course of its life. Maybe if there can be a vaccine that just destroys beta-amyloid fragments or prevents their expression that could cure a great deal of Alzheimer's.

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  4. Immunological Malfunction
    My case study was on the immunological malfunction and their respective therapies. Specifically this case study related to X-linked agammaglobulinemia with hyper-IgM syndrome. This is an X-linked hereditary disease that causes the inability to switch from the IgM monomer to other monomers due to a lack in the CD40 Ligand of T cells. This mutation causes T cells to undergo immunoglobin switching. The current therapy for this is immunoglobin infusions every 3/4 weeks for the rest of the patients life or a bone marrow transplant with an HLA matching sibiling could potentially cure the patient. Also this disease can lead to HIV like conditions with frequent infections and overall death at a young age. Because it is X-linked trait there is a greater chance for men to get it. They only need one allele for the CD40 mutation

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    1. Sameer, when I first read this post I was kind of lost. Maybe it was the name of the disease or the fact that I forgot a lot of information from our last unit. Binding of CD40 ligand on T cells to the CD40 of APCs leads to a chain of immunological events. This hereditary disease sounds very interesting and should be studied more.

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  5. Chimpanzee Droppings Lead Scientists to Evolutionary Discovery
    Chimpanzee families separate into subgroups during the day to forage for food and return to the main group to sleep in the trees at night. Dr. Hahn and a team of scientists followed multiple groups of chimpanzees and collected their droppings to be used to check for SIV (simian immunodeficiency virus). Retroviruses are known for their ability to mutate constantly which creates different strains of the viruses and making it harder for the immune system to detect the antigen. It is believed that SIV was able to jump from monkeys to humans (a process known as zoonosis) by mutating qualities that allow it to be infectious to humans. Dr. Hahn followed groups of monkeys from three different countries. By finding which groups of chimpanzees have SIV, Dr. Hahn can possibly pinpoint the site of zoonosis. Hahn conducted the test for antibodies (using droppings) and placing the SIV antigen into the DNA to see if any anti-SIV antibodies bind to the antigen. To test this, a second antibody attached to an enzyme that enters the plastic plate which ultimately determines if the retrovirus is present (alteration in color of the plate after interaction).

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    1. It is amazing to see how a virus can evolve and be able to go from organism to organism. This shows how complicated the process is even though the virus is in chimpanzees it still cool to see how it can have similar effects within humans. Zoonosis also shows the qualities of a virus that can cause infections within other orgaisms.

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    2. I agree with Shivam, it is amazing to see how a virus can evolve and be able to go from organism to organism. That’s what makes it so hard for scientists to know more about viruses. They evolve so quickly! And it’s also hard to find cures. For example, AIDs is a virus that, so far, has no treatments. There are ways to slow down the effect of AIDs (such as the treatment that Magic Johnson is on), but there is not a true cure.

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  6. I read the article called "Why Sex is Good" to refresh the significance of asexual and sexual reproduction. This article, however, emphasized the use of each method especially in organisms that reproduce in both ways. Not only did this article consist of information about each method of reproduction, it also talked about an experiment involving yeast and allowing for it to separately reproduce both ways. The results proved that the harsh and stressful environment was a major factor in making sexual reproduction more necessary. This was also proven through observing a certain type of snail. This snail showed researchers that the stressful environment led to higher number of sexual reproduction so that the genetic variation would allow offspring to live through the environment. There are a few drawbacks to sex as stated in the article. It explained that sometimes changing the genetic code of an offspring could potentially cause a great, previous gene combination to break. It also said that asexual can greatly increase the number of individuals in a population, two times as efficient as sexual reproduction.

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    1. Sahil man you took the article I was going to do. Anyways it's pretty interesting how different organisms reproduce and why they do it that way. For example with both the yeast and the snail, the environment plays a major role in telling it when reproduction is necessary. It's crazy how animals pick up on these kinds of things. Also it's very hard to decide whether asexual reproduction or sexual reproduction is better because both have pros and cons to them.

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    2. It's quite interesting that the animal (in this case a snail) becomes sexually active when the environment becomes stressful. Such a characteristic is great for natural selection because the snail is able to pass on its genes to offspring even in dire situations. Also, asexual reproduction makes sense in its efficiency since some organisms (like plants and polyploidy) use asexual reproduction when mating partners are scarce.

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  7. Abracadabra: Magic Johnson and Anti-HIV Treatments
    For those of you that don't know, Earvin "Magic" Johnson is one of the greatest basketball players to have ever played the game of basketball. Throughout his career, Magic was apart of many NBA All-star Games and the famous 1992 Dream Team. Back in 1991, Magic told the world that he was HIV positive and since then his life has changed. Although he is HIV positive, he is a non-progressor. Meaning he lives with HIV without major health
    complications and his immune system seems to keep the virus under control. The article goes on to say that Magic used this therapy called HAART to try to keep the virus under control using a combination of antiretroviral drugs. HAART therapy has prolonged many peoples lives, but the bad news is that HIV is a very smart virus that has developed mechanisms to overcome the blocks imposed by drug treatments. Pretty much over time the presence of a drug may cause random mutations to develop. So now there is a therapy that alternates time spent on antiretroviral drugs with time spent off drugs. This way will hopefully help the immune system with control of HIV.

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    1. It is amazing what Magic Johnson has and is enduring. HAART is like "a cocktail" of antiretroviral drugs. However, the medicine cost a lot, around $ 1000 per month. Also the HIV virus mutates fast. For example one mutation in the RNA of the virus and the medicine could become ineffective. We need to figure out how to get free of HIV instead of slowing it down. The mutation rate for the virus is faster than the rate of the new medicine produced.

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  8. Each Polychlorinated biphenyls or a PCB differs in its quantity
    and location of the chlorine atoms. PCBs were once an insulator in electrical components but where halted because they were toxic. Scientist have many theories about PCB. For example, PCB has been found out to be made by atmospheric transport entering the atmosphere by burning organic material and evaporation. Another Theory is that humans produce PCB and pass it on through the environmental. Atmospheric Transport helps to explain how the PCB travels from Humans to the enviorments and lakes that are untouched by humans. According to scientists the Sockeye Salmon coming to reproduce in Alaskan lakes contain higher level of PCB and match the same PCB found in oceans. Even though PCB has been halted in production it is still in production within enviorments and will be for a long time.

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  9. I read the case study involving Influenza and the Influenza Vaccine. It was about two coworkers Mary and Karen at the grocery store. Mary suggested Karen to spend the $15 for the vaccine to stingy Karen. Karen says it's pointless to get vaccinated because you are going to get sick anyway. The influenza virus causes fever, aches and malaise. Karen was affected by a sinus infection caused by bacteria. The vaccine protects you from the most current influenza strain and not other viruses. Influenza evolves, so it is harder for your immune system to counteract. New versions of the influenza vaccine are designed to protect against the most frequently recognized strains of influenza. After reading this article, I am going to get my shot. I have never been to Kroger, Walgreen, or CVS to get a flu shot. I always believed that I was stronger than the viruses, and I do not want to be one of the 36,000 people that die from the influenza.

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    1. It is amazing that the influenza virus is always evolving and there is no way to completely stop the spread of the flu. The vaccinations keep becoming obsolete as the influenza virus. Hopefully, we will be able to make a vaccination that will be able to stop the spread of the flu

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    2. It is interesting that the flu vaccine only protects you from the most current strain of the virus, leaving you vulnerable to the many other viruses. Karen is justified in saying she could get sick anyways if the virus is always evolving. It is scary that the flu can evolve, and that it becomes harder for your immune system to defend itself and for scientists to treat the virus.

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    3. Thomas "Shakespeare" WalkerDecember 2, 2012 at 7:43 PM

      I think that this only proves that there will be an apocalypse.
      Not really, but seriously, this shows the complexity and beauty of the struggle between living organisms to win the game of life. The minds of millions of scientists are working out ways to combat viruses and bacteria as are everyone's bodies. But, no matter how many we kill, there will always be more, waiting to survive and reproduce. To evolve, to make history, and change it. We can be the most technologically advanced organisms in the world, yet we will all be able to be infected by a single cold virus. The world of science never ceases to amaze me. From the incomparable size of everything in the universe, to the seeming simplicity of an influenza virus.

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    4. Rishib, you smart guy.... i would definitely have to agree. I have gotten my flu shot ever year and i have not experienced this horrid disease, and hopefully i will never have to. Our bodies need to adapt to these viruses so we can overcome them when the time is necessary (adaptive immunity).

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  10. The Case of Eric, Lou Gehrig’s Disease, and Stem Cell Research
    Lou Gehrig’s Disease is difficult to diagnose and is a neuromuscular disease. It affects 11 out of every 100,000 people and there are 13 new cases diagnosed every day. The cause is usually unknown and the onset of the disease is rapid. 80% of people diagnosed with the disease die within 5 years and 50% die within 18 months. The disease destroys motor neurons, which control the muscles and as the muscle receives fewer and fewer signals, the muscles weaken. Embryonic stem cell therapy could be a possible cure for Lou Gehrig’s Disease because it isolates stem cells from human embryos. When the stem cells have matured and developed in a normal population of cells, the stem cells could help repair the damaged neurons and muscles. Embryonic stem cell therapy has political and legal issues that could get rid of the research program.

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    1. I have never heard of this disease before. According to the statistics you gave, I assume it is because it is extremely rare and does not call for as much medical attention and funding as many other pressing topics of our day. However, it seems very lethal and more research should definitely be done to understand the nature of Lou Gehrig's Disease. Stem cell therapy can be used for a plethora of diseases and conditions, but there is so much controversy about it because of legal, ethic and legal issues. I am sure there are other possible ways to aid recovering from this disease other than stem cell therapy.

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    2. This is very interesting I honestly myself have not heard about Lou Gehrig's disease. It is very sad how many people have been affected by this and how fast it can potentially kill them. I believe that they should fund stem cell research more, because not only just this disease but stem cells can resolve or cure many diseases. The government needs to get involved into this, and fix the political and legal issues of this program.

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  11. Case of Seasonal Affective Disorder (SAD) Written by David Dean
    This case study takes a look at how a change in exposure to Ultra-Violet light can cause depression-like symptoms. The pineal gland excretes the hormone melatonin, which correlates with the amount of time spent in UV light (diurnal pattern). However, during the winter months, there often are less UV rays, hence creating an increase of melatonin. Without the production of melatonin, several processes cannot occur, such as regulation of body temperature and blood pressure. With this increase of melatonin, you would think that the body would function more efficiently, right? No. In fact, the increase of melatonin due to less UV exposure can cause depression, excessive sleep, and overall lethargy, and is called SAD. To make a connection to World History, this could explain why so many festivals of lights are held during the winter months (Christmas, Hannukah). An explanation for the depression is the SCN, a cluster of nerve cells in the brain, fully named the suprachiasmatic nucleus. These cells expect a certain timing for the body; when the season changes, this clock is thrown off when its connection to the eyes detects less light. This induces the increase of melatonin, which has not been fully figured out at this time. SAD is a very serious disorder, and affects millions, including my father. There are paths along which some progress has been made for treatment, but not much other than to feed the body more light.

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  12. I read the “Too Many Deer! A Case Study in Managing Urban Deer Herds” case study by Eric Ribbens. This study is about possible techniques of reducing the deer population at the Wesselman Woods Nature Preserve. Keeping a high population of deer would have a devastating effect on the plants on the preserve. These herbivorous deer would have no other option but to eat the plants for nutrients. Due to this, people suggested shooting deer, trapping and relocating them, or making it harder for them to reproduce. In my opinion, making it harder for the deer to reproduce would be the best option. There would need to be prezygotic or postzygotic barriers to prevent the deer from mating and having a successful fertilization. Prezygotic barriers such as behavioral isolation would prevent mating to some extent. Allopatric speciation would only lead to the creation of genetically similar species, so separating the deer into groups would not be beneficial, unless the deer are separated by gender. One person mentioned an albino deer, and said the deer was “just like everyone else.” This is true. The only difference between an albino deer and a non-albino deer is a single mutation that changed the albino deer’s phenotype. The case study basically listed options of how to reduce the deer population.

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  13. Studies conducted in Alaska show that Steller sea lions populations are drastically decreasing. However, the populations are decreasing only in certain areas, including the Prince William Sound region. Scientists are particularly concerned for sea lion pups because most are dying before they are three years old. They are vulnerable to changes in the environment, and they are reliant on their mothers for survival. Sea lions are predators and eat pollock and herring, which are undergoing their own population decreases. Fish populations are changing, which affects the ecosystem and thus sea lions. An experiment was conducted in Vancouver to analyze diets of pollock versus herring. Sea lions who ate herring gained weight, while those who ate only pollock lost weight. So, the environments and diets of sea lions most affect their survival, and bad conditions are causing the sea lion population in Alaska to decrease dramatically.

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    1. It's interestingthat sea lions are endangered and that it is in only certain areas. i see that it's not only the fact that they are being hunted but that their food supply is also the reason behind the decrease in population.

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  14. I read the case study on Global Climate Change: What does it look like? In this case study it talks about how a PhD- paleoclimatologist turned into a TV meteorologist. In which this young women Sara has found herself into a climate that reminds her of the early Eocene: it’s hot, humid, and seems tropical. Sara being a meteorologist has seen many things and after one day in a very bad weather system, standing a hundred feet away a house sliding down the ridge she thought in her head if the weather was part of a global climate change instead of a onetime occurrence. She started to research on average conditions and changes in different areas, for example she learned Southeastern US, has gotten much warmer since 1985 for average temperature. She started to realize that we might be one of the causes of this climate change. Realizing that carbon dioxide and other gases is a major cause of our climate change. We contribute 645 million tons of carbon dioxide emissions into the atmosphere every year as the number increases, also for every galloon burned, 19.4 lbs of carbon dioxide is distributed into the atmosphere. The average mile for a passenger car in the U.S is around 22. The global surface temperature of the planet has increased 0.6 degrees Celsius, because of this there has been increase in frequency of extinctions, higher temperatures, ocean levels, droughts, and extreme incidents. By doing this case study and learning about our world, it shows us how we can take action. By taking inventory of our own usage, and by doing this seeing how we can decrease our consumption and energy as individuals. As the case study said it all depends on the way all of us live as a whole. “Our future environmental stability of our planet is ours to support, or ours to lose.”

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  15. Ever since the outbreak in early July in the Congo, women began seeing Dr. Mombutubwa complaining of flu-like symptoms followed by diarrhea; but they also showed telltale red pinprick spots of blood on their arms and blood filled eyes. These women were harbingers of the Ebola virus and there was little to be done. Joe Mackey, who worked for the Epidemiology Intelligence Service of the CDC, was flown into the Congo to stop the spread of Ebola. On the way, he took time to organize his thoughts: Ebola must have a regular animal or plant host to proliferate in between human epidemics because humans die too quickly from the virus’ aggression. Women work primarily in the fields (around insects, rodents, and birds) and prepare bats for communal feast. Once Mackey arrived in the Congo, with the assistance of Mombutubwa, he began taking samples of local animal tissue to identify the probable host. His study was designed to test which animal was best able to support replication of Ebola as any virus binds to very specific cell receptors. Several animals, after incubation of 28, harbored the virus, but the most promising was the Wahlberg’s epauletted fruit bat. To add to the probability, Dr. Mombutubwa revealed there is usually a large bat migration in April, which the local hunters take advantage off; the women would then prepare the uncooked carcasses, a possible explanation for the exposure pattern. Furthermore, because the bats leave by mid-May, it would account why the Congo village frequently undergoes cycles of Ebola epidemic. Similar to Suzanne’s response, environmental phenomena can very rarely be summarized with a cursory glance. Numerous factors must be analyzed to account for why an event happens sometimes in some places, and other times in other place or not at all. The sea lions were decreasing only in certain areas because of the nature of the herring and polluck fish migration. Similarly, Ebola outbreaks were only occurring in the summer of the Congo presumably because of their migratory pattern. It is this close study which avoids paranoia and panic as to whether a catastrophic event is striking an area or if it is an environmental response.

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  16. First off, I apologize for posting so late as I was working on several other things today. The case study Helicobacter pylori and the Bacterial Theory of Ulcers caught my eye particularly because I have studied stomach ulcers and helicobacter pylori for the Anatomy event in Science Olympiad. This article traces back to the discovery of bacteria residing in the stomach. It was believed that a stomach was sterile and any bacteria found in the stomach was a result of a contaminant during an experiment. However, Dr. J. Robin Warren, a pathologist at the Royal Perth Hospital (RPH) in
    Western Australia, noticed how abundant bacteria is present in the lining of stomachs of patients with gastritis (inflammation of the stomach). This recurrence of this spiral bacteria among his many experiments convinced him that bacteria does indeed reside in the stomach, contrary to the mainstream belief of that time. Although the stomach is highly acidic, this bacteria can be found attatched to the mucosa out of the reach of ingestion. His findings were largely rejected by the community.

    Surprisingly, much research had been done about this spiral bacteria before. Italian pathologist Giulio Bizzozero found it in the stomach of dogs in the late 1800's. Fiber optic endoscopy in the 1970's made it possible to report gram-negative bacillus in 80% of gastic ulcer patients. All of these findings were rejected and assumed to be caused by an contaminant in the equipment. Determined, Warren and Marshall conducted an experiment and found bacteria to be convincingly abundant in the stomach linings of patients with diseases such as ulcers (gastic and duodenal, gastritis, duodenitis, and as well as in normal stomachs. Something that REALLY shocked was how Marshall himself drank 30 mLs of peptone broth containing Helicobacter pylori from one of his patients to prove how H. pylori causes gastritis! Sure enough, he started vomiting and developed the disease. After taking antibiotics that attack the gram negative bacteria, his symptoms disappeared. The medical community soon believed the studies by 1994, after many similar studies have been conducted. This shows how far science was gotten in the past 20 years- from accepting bacteria as a cause of stomach ulcers and inflammation to Science Daily's daily headlines.

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    1. Sorry for all the grammatical errors.. it's late and I'm tired -.-

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  17. The way to become a surrogate mother is a long line of paperwork to complete for the safety of them and the child. Many use birth control pills to regulate and match their menstrual cycle with the actual mother. An embryo is then placed within the woman’s body, that is having the child. Then regularly blood work and checkup have to be given to the woman carrying the child for both their safety. The process of having someone else’s baby could be viewed either as moral or unmoral. Some see it as a woman helping an incapable family have a child. While other find it wrong because after the birth has been given the child then is given up to the other family. The process is also legal because many participate if they don’t have anything against with the idea. Nothing in the end I illegally performed.

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    1. I believe that there is nothing "immoral" about the idea of surrogate mothers. It is a win-win situation when accomplished correctly. If a couple is unable to conceive their own children, adoption should not be the only other option. As for the surrogate mother, if each individual is willing to carry the physical and emotional burden that may come along with the process, then all is well. I also find it interesting that surrogate mothers must match up their menstrual cycles with the actual mothers. It is also amazing to know that science has advanced so far as to being able to give birth to another couple's baby.

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    2. I agree with Lily it shouldn't be thought of as "immoral", however, I do believe adoption should be highly considered before the thought of having an expensive and highly worrying situation like this. The surrogate mother is obviously going to have a bond with the child and thier are plenty of beautiful childern that need a home. People get to caught up in having a child that has their mother's eyes and their father's hands and things of that nature.

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  18. Rusty Cole
    Mystery in Alaska
    The film "Mystery in Alaska" by National Geographic showed us that there was a tremendous decrease in sea lion populations in Alaska. Many hypothesis were offered to the cause of this strange occurance. It is believed the main reason why sea lions population decreased was because of the augmenting fishing of the pollock, one of the sea lions main food sources. Due to the large amount of fishing, a ban of fishing the pollock was implemented. Later the pollock out numbered the herring, another one of the lions main food source. The pollock eat small fish like herring, which is believed to be why the sea lions population decreased. The herring are a much better food source than the pollock because they digest easier and faster in the lion. Pollock have less calories and they have a lot of fat.

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  19. Living With Her Genes: Early Onset Familial Alzheimer’s Disease

    I have always been interested in diseases affecting the brain such as Alzheimer's disease. After learning about genetic testing in biology, I was further intrigued by the subject. In this case, a woman named Suzanne experiences bother her dad and her sister falling ill to Alzheimer's disease. She is aware that the chances of carrying the autosomal dominant gene was a 50% chance. She and her husband decided it would be best to be genetically scanned to determine whether she carried the mutation called "APP" which results in Alzheimer’s disease. The results came back positive for the mutation which led to the next question of whether or not the couple should have kids knowing the chance of developing Alzheimer’s disease was a 50% probability. A process called pre-implantation genetic diagnosis involves in vitro fertilization and genetic testing of the embryo before being implanted into the uterus. Suzanne was able to give birth to a healthy girl in 2000.

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    1. This sounded like a great case! I am also interested in the brain and diseases that affect the nervous system. I find it amazing and courageous that these parents decided to go through with the birth even though "APP" was present. I honestly don't know if I would have been able to make that choice as a parent for my child's future, so I applaud Suzanne and her husband.

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  20. I'm Looking Over a White Stripped Clover

    The case study I read discussed the theory of Natural Selection and more specifically the abundance of certain species of clover in certain micro-habitats in the United States. What distinguishes these two species of clover is not only the obvious White Strip but also that the stripped clover contains small traces of cyanide. The presense of this toxic chemical makes it undesirible by many herbivores and thus promotes larger populations of the clover. The story, however, doesn't end there. Based on this information the stripped clover should absolutly dominate the gene pool on account of its ability to produce cyanide. However, certain places promote certain species of clover. In Long Island for instance, their are a series of small hills and below sea level depressions behind the island's dunes. These two micro-habitats differ in that the vegetation (clovers) in the depressions and on the hills have adapted to the conditions of their habitats. The different conditions of the surronding enviorment promote the well being of certain species and thus advances the passing down of genes. This is why their is a larger plain/ stripped clover ratio in minnesota than north carolina. In concluesion, surronding envirnmental factors as well as benefiting mutations cause natural selection to occur for the better suited species resulting in further evolution and species differentiation in accordance with habitual factors.

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  21. A Can of Bull?

    The name here really caught my eye, especially considering it is playing off the name of one of the four energy drinks that were compared in this case. This case discusses what energy drinks REALLY have to offer customers and if they actually do provide "energy" for the body. The four drinks compared were XS Citrus Blast, Red Bull, Sobe Adrenaline Rush, and Impulse (as well as Coca-Cola), and the first component that was broken down was calorie count because it is a simple factor of a drink's energy content. Due to the information given, XS Citrus Blast can boast to having almost no calories yet still having a lot of "energy" to give! This does not seem to make much sense because of the basics of biological energy... The other drinks have from 110-140 calories, but all the drinks have important energy boosting components like taurine and caffeine. These two ingredients are said to improve reaction time, concentration, memory, and reasoning, but there are also sugars in each drink that could prohibit these ingredients from working at their full potential. Overall, these drinks could be helpful to athletes in smaller amounts, but drinking them too much could be detrimental because of possible addiction and sugar overloads.

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