Marine Biology Essays (428 words) - Aquatic Ecology, Ocean Pollution

Marine Biology A major source of coastal pollutants, human sewage fouls bays and beaches with both toxic and nontoxic pollutants. Although billions of dollars have been invested in sewage treatment plants to treat wastewater, new and growing coastal communities have increased the amount of discharge into oceans and estuaries. The United States Office of Technology Assessment has identified thirteen hundred major industries and six hundred municipal wastewater treatment plants that discharge into coastal waters of the United States. Many toxic substances enter the sea through the sewer systems, but others originate as industrial discharges. For many toxic substances, we do not yet know how to determine their extent or fate in the marine environment or to evaluate their effects on marine life. Some of the better-known trace metals and toxic chemicals include mercury, copper, lead, and chlorinated hydrocarbons. Chlorinated hydrocarbons, synthetic chlorine-containing compounds, are created for use as pesticides or are by-products of the manufacture of plastics. Oil is a very dangerous thing when it comes to oil spills into the ocean. These catastrophic oil spills engender a concern for the marine environment as no invisible containment can. Spilled oil floats on seawater and provides a constant reminder of its presence until it is washed ashore, sinks, or evaporates. Large volumes of oil suffocate benthic organisms by clogging their gills and filtering structures or fouling their digestive tracts. Marine birds and mammals suffer heavily as their feathers or fur become oil soaked and matter, and they lose insulation and buoyancy. Until recently, marine debris was considered to be of minor importance when compared to other pollutants. Problems caused by marine debris, however may rival or exceed those resulting from some better known pollutants, including oil. By definition, marine debris is any manufactured object discarded in the marine environment. When dumped, it may sink to the sea floor, remain suspended at mid-depths, or float at the surface and eventually be carried ashore by winds and waves. Plastics constitute as great an environmental threat as all the other kinds of debris, combined. Although plastics may break up into smaller pieces, they degrade much more slowly than most other kinds of debris, and most plastics float. Concentrations of plastics tend to be highest in the Northern Hemisphere, where vessel traffic is the heaviest, where most plastics manufacturers and fabricators are located, and where more intensive recreational use is made of beaches and coastal waters. Hopefully, as we approach the twenty-first century, we can learn to leave some old and wasteful habits behind. It will not be easy or simple, but each one of us must develop a sense of stewardship toward the world ocean and its resources that is reflected in our personal as well as our political decisions.

SeaWorld The Truth about Tilikum Professor Ramos Blog

SeaWorld The Truth about Tilikum Blackfish is a documentary about a very special Orca named Tilikum. The film shows the story starting with his capture and goes up to his transfer to SeaWorld Florida. The film shows some world defining events that unfolded in his presence. Blackfish was first shown at the 2013 Sundance film festival, it was such a great film that it was backed by Magnolia Pictures and CNN films for DVD release. The documentary consists of interviews from real life SeaWorld trainers who worked with and around Tilikum. It also includes interviews with scientist from different backgrounds to help show the dangers of keeping Orcas (AKA Killer Whales) in captivity and used for show. Blackfish sought to show the world the truth behind SeaWorld’s treatment and misuse of Orcas, by using the story of Tilikum. Tilikum’s story begins in 1983. In his remorseful interview, John Crowe tells the story of capturing Tilikum and other Orcas. He states, â€Å"it’s like kidnapping a little kid from his mother† (Blackfish, John Crowe). Tilikum was one of the largest Orcas ever captured at two years old he was roughly 12 feet long. He was sold to a park named Sealand of the Pacific. Tilikum remained at this park for about 7 years. According to an article on the PETA2 website by Kim Johnson â€Å"on February 21st, 1991 Sealand trainer Keltie Byrne fell into the pool containing Tilikum, he dragged her to the bottom and she drowned.† (Kim Johnson) Shortly after this event Sealand closed and Tilikum was sold to SeaWorld. At SeaWorld Tilikum was kept in a pool with 2 other Orcas. The problem was that Tilikum was from a different family then the other two. Blackfish interviews Eric Walters a former SeaWorld Trainer who states â€Å"during certain times of the year he would be co vered with rakes, these are teeth to teeth scratches on the skin †¦ his entire body would be covered with them† (Blackfish) This shows that the animals really did not get a long the 2 females would gang up on Tilikum and attack him throughout the night while they were in storage. This would cause Tilikum to be more aggressive. The film goes on to explain that although Tilikum showed aggressive behavior at times, he was still used in shows and trainer were still allowed to enter the pool with him. This resulted in two more deaths, first Daniel P. Dukes in 1999 and Dawn Brancheau in 2010. SeaWorld played off Daniel Dukes death as an accidental drowning due to his own discourse. They claimed he was a mentally ill person who had gotten into the park afterhours and slipped into the pool and drown. In multiple interviews with former SeaWorld trainers conducted in the Blackfish film they contradicted the official SeaWorld statement. They said that there was evidence that Tilikum had drowned him just as he done to Keltie Byrne at Sealand. SeaWorld also blamed Dawn’s death on herself. Saying that it was her fault and she wasn’t supposed to be in the pool. This event lead to Tilikum being kept in a small pool in isolation for nearly a year. After that Tilikum was allowed to be used in shows again, but he was transferred to SeaWorld Florida. This is where the story of Tilikum ends in Blackfish, in January 2017 Tilikum died. Blackfish does an extremely good job at telling us how SeaWorld treats their animals and, even after multiple incidents allowed people to interact with the dangerous animals. Blackfish uses the story of Tilikum to show us multiple wrong doings and lies that come from SeaWorld. The film did have a large effect on SeaWorld after it was released to DVD and became widely popular. This was known as the â€Å"Blackfish effect† SeaWorlds stock dropped drastically as did park attendance. The film did a very good job at teaching us a little bit about whales. It teaches us about Orcas families known as Pods, their lifespans in the wild, dorsal collapse and shows us how they are aggressive in the wild as well. For about 3 years after the film was released SeaWorld had no response to it. Eventually SeaWorld created a website as response to Blackfish, this site is named â€Å"SeaWorld Cares† on the website they state, â€Å"The film relies on animal rights activists masquerading as scientists.† (SeaWorld Cares) and â€Å"The film spins an entirely fictitious account of Dawn Brancheau’s death in order to advance its anti-captivity narrative.† (SeaWorld Cares) SeaWorld felt that, because they scientist loved animals and testified against SeaWorld in a court case with OSHA, they were not real scientist. One of the most important scientists interviewed was Kenneth C. BALCOMB who is the founder and lead investigator at the Center for Whale Research. According to the Center for Whale Research website â€Å"Kenneth C. Balcomb spent 12 years sailing around the Atlantic Ocean following whales and studying them† (Center for Whale Research) This already shows that the SeaWorld Cares website is lying to try to brush the Blackfish film under the rug. In Blackfish they show us multiple lies that SeaWorld has their employees tell visitors such as, Dorsal fin collapse happens in about 50% of all male Orcas and they have a much lower mortality rate in captivity. In the article The Truth about ‘The Truth about Blackfish’ it states that â€Å"in the wild, only 1-5% of male orcas in populations have fully collapsed dorsal fins.† (David Neiwert). The article also states that â€Å"Their annual mortality rate was more than two and a half times higher in captivity than in the wild† (David Neiwert). In conclusion Blackfish does a fantastic job showing the truth about SeaWorld and Tilikum’s life story. It uses multiple scenes which prey on emotions and gets the viewer to feel sympathetic to the animals and how they are traded. The film employs reputable scientist to prove every statement it makes. The previous trainers interviewed in the film are all based on personal and first-hand experiences with Tilikum and other Orca’s at SeaWorld. Remember that next time you are thinking of going to SeaWorld, think of this review and the truth behind SeaWorld and the story of Tilikum Barrett-Lennard, Lance G., et al. â€Å"Predation on Gray Whales and Prolonged Feeding on Submerged Carcasses by Transient Killer Whales at Unimak Island, Alaska.† Marine Ecology Progress Series, vol. 421, 2011, pp. 229–241. JSTOR, JSTOR, jstor.org/stable/24874414. Blackfish. Directed by Gabriela Cowperthwaite. Magnolia Pictures, 2013. â€Å"Truth about Blackfish.† SeaWorld Cares, 2015, https://seaworldcares.com/the-facts/truth-about-blackfish/. Center for Whale Research. The Center for Whale Research Non-Profit Organization, 1976, https://www.whaleresearch.com/about-orcas Accessed 11 Nov. 2018. David Neiwert. â€Å"The Truth about ‘The Truth about Blackfish’ † The dodo, 7 May 2014, https://www.thedodo.com/the-truth-about-the-truth-abou-540025703.html Johnson Kim. â€Å"Tilikum’s Life Story Will Bring You to Tears† PETA2, 06 Jan. 2017, https://www.peta2.com/news/tilly-seaworld/ Accessed 2 Dec. 2018. Zaveri Mihir. â€Å"SeaWorld Agrees to Pay $5 Million in ‘Blackfish Effect’ Case† The New York Times, 19 Sept. 2018, https://www.nytimes.com/2018/09/19/business/seaworld-blackfish-fine.html Accessed 25 Nov. 2018.

Writing College Papers Under Pressure How-Tos

Writing College Papers Under Pressure How-Tos Writing College Papers Under Pressure: How-To’s Any student knows how important it is to be able to properly manage time. With the ever-increasing amount of homework, academic assignments, projects, and other tasks routine for colleges and universities, 24 hours a day just isn’t enough for school and life. Besides, students aren’t robots, so huge workloads often lead to excessive stress. As a result, a typical student – a person most likely unable to manage stress (and even less likely to manage time) becomes a person with a chronic lack of time who’s constantly worried, disturbed, or stressed out. Therefore, to make students’ lives less stressful, we’ve prepared a short guide on the most popular time and stress management techniques. Using these techniques, you’ll be able to conquer your workload without straining your nervous system. So, first are the time management techniques: Use all kinds of lists and schedules. It might be a good idea to keep a record of things you need to do in separate lists, categorizing them by different criteria. For example, you could have lists titled â€Å"Things to do for biology class;† â€Å"To-do list for the next week;† â€Å"Most urgent stuff;† and so on. You can also estimate the approximate time needed to accomplish each of the tasks that you write down in these lists. Keep these lists where you can see them; this way you’ll never forget to do something important, and having them in front of your eyes all the time will help you allocate time more effectively. Don’t multitask. Focus your efforts! This may sound like unpopular advice, since the modern world values multitasking. However, it’s been proven that multitasking hinders performance. So, when starting to work on a task, you might want to focus all your efforts on it for a short period of time. Paraphrasing the famous saying: 80% of results are achieved during 20% of time spent working on a task. Eliminate distractions. It’s surprising how many things can actually distract us right at the moment when we need to focus on an important task. Students know that sometimes even cleaning up can be a huge distraction, especially when you need to prepare for an exam. So, make sure you block access to social networks for the time you’ll be studying (there are plenty of programs designed to do exactly that); turn your phone off; isolate yourself in a quiet room with no TV; and have only the needed textbooks and materials in your proximity. You’ll be astonished at how much time you have for actually studying when you eliminate all distractions! Maintaining a cheerful and healthy spirit is as important as being able to do everything on time. So, here are some relaxation and stress management techniques for you. Conscious breath. This is the basis of a huge number of meditation techniques, and for a good reason: breathing in such a way can significantly improve your overall psychological condition, help you relax and refresh. The technique is simple: you need to start breathing, paying full attention to the very process; feel how the air flows through your nose, how it fills your lungs. Notice a small pause between every inhale and exhale. It’s recommended that you breathe slowly, while being perfectly still. You must also do this exercise in silence. Physical exercises. It’s well-known that physical exercise after mental activity is a great way to relax. You don‘t necessarily need to go to a gym; instead, you can visit the nearest swimming pool. Swimming there for 45-50 minutes at least twice a week will positively affect not just your body, but your mind as well. Slowing down. Western society is fascinated with the idea that a person is worth something only when he/she is active, and has achieved something outstanding. This is the particular factor responsible for our crazy pace of life. Although it’s always good to accomplish something worthwhile, even more crucial is to maintain a balance between your mental health and your activities. At least once a week allow yourself to be slow. Don’t rush anywhere; don’t strain to do as much as you possibly can. You can afford being inactive. Take a slow walk in the park; ignore incoming messages, or at least do not reply them immediately; turn off your reminders and alarms; move slowly, think slowly. After a period of practicing this exercise, you’ll notice that you’ve become calmer. These are just some of the most popular techniques among hundreds of others. Feel free to find those that suit you the most, as there are no universal methods only those that work or don’t work personally for you. Good luck with writing! Additionally you may use professional custom writing service to buy college papers online.

Big Ideas Assignment Essay Example | Topics and Well Written Essays - 1000 words

Big Ideas Assignment - Essay Example Through this activity, the partners would be able to learn about each other. Later on the students would exchange partners and do the same thing. Each student would at least have four partners during the activity consuming at least 4o minutes. Then after which, each student shall be required to present to class who they have known and tell what they know about the said partners. So for each student, there would at least be three presentations each. The partners would then confirm the information relayed about them by their partner. Expectations on the Application of the Activity: It is expected by the proctor of the activity that the understanding of the students on themselves and how they see themselves with others or from others view point should increase. Besides that, it is also hoped that each student be given the chance to see through the situation thus making it easier for them to establish camaraderie with the whole class as part of their social development. To instill aesthetic procedures in the activity is one of the main aims of the educator herein. To do so, several ice breakers in the middle of each division of the process is expected thus giving ample motivation to the students to pursue with the activity. Through bodily activities, the educator believes that the students would have greater sense of grasping the lessons that they are undergoing hence giving them the chance to refuel their minds so as to be able to accept the different points that are presented to them in class. Education has always been an important aspect in the course of personal and societal development as a whole. Every individual has an urge and personal willingness to learn valuable information that varies from either practical knowledge o scientific ones. However, all of these relevant informations are very much needed by every individual to be able to develop their own self and become self-sufficient and

1968 Democratic Convention Research Paper Example | Topics and Well Written Essays - 1500 words

1968 Democratic Convention - Research Paper Example Despite of its rich legacy, there have been some events related to the history of this party, which still haunt the stakeholders (Campbell, 2008). One of these events is the â€Å"Democratic National Convention of 1968 at the International Amphitheatre in Chicago, Illinois† (Campbell, 2008). This paper is an attempt to present a brief account of the events that led to this convention, the happenings during the convention and events that took place in the aftermath. Discussion Before light is shed on the convention, it is important to draw a rough and succinct sketch of the events leading to Democratic Convention of 1968 that would help in better understanding of the entire event and its happenings. Events leading to 1968 Democratic Convention Assassination of Martin Luther King, Jr. Without any doubts, the man who saw the dream, Martin Luther King, Jr. remains as one of the most influential personalities in the American history (Hoffman, Leary & Mailer, 2008). During the late 1950s and 1960s, he had become the icon of American liberalism, anti Vietnam War advocate, civil right activist and leader of the peace movement (Dautrich & Yalof, 2009). It was on April 4, 1968 when he was assassinated at the Lorraine Motel in Memphis, Tennessee. This created widespread anger, frustration and rage in the public and riots spread in major United States, such as â€Å"Washington D.C., Kansas City, Baltimore, Louisville, Chicago, and various 100 other major cities causing damage of more than 50 million US dollars† (Farber, 1988). In fact, Chicago has not witnessed such magnitude of riots since 1968. During these disturbances, â€Å"11 citizens lost their lives, 48 injured, 90 police officers were wounded, and more than 2156 were taken into police custody† (Kusch, 2004). Despite the fact that the city appeared to be getting back to the normal after a week or so but this event installed the first wave of anger and frustration within the hearts of minds, par ts of which became evident during the convention as well (Edy, 2006). Assassination of Robert F. Kennedy After the death of Luther King, Jr. Robert F. Kennedy was the first political leader, who was also running for the Democratic Party nomination for President. Kennedy had lost his brother John F. Kennedy earlier in the decade (Farber, 1988). Shortly after addressing his supporters at midnight in a ballroom at The Ambassador Hotel in Los Angeles, he left for addressing a press conference (Kusch, 2004). On his way to the conference, he took the route that went through the kitchen and a Palestinian immigrant, Sirhan Bishara Sirhan, who shoot Kennedy in the chest three times. He died after 26 hours, thus depriving the democratic party of a charismatic and influential leader who would have gone on to win the Democratic convention (Campbell, 2008; Hoffman, Leary & Mailer, 2008). Decision of Lyndon B. Johnson not to contest for the second term Lyndon B. Johnson, one of the four political personalities in the history of United States to serve as the President, Vice President, Representative, and Senator during his career, was the 36th president of the United States who served during the 1963-1969 era. He served as the vice president during the Kennedy era and took over the job as the president of the country after his assassination. He ran for the office after completing that term and won with an overwhelming majority. Johnson is still praised by critics and observers for his domestic policies such as â€Å"Great Society legislations† (McGowen, 2003). However, he paid the price for increasing American involvement in Vietnam War in form of his sharply declining popularity, both in the American

Protection Against Elderly Mistreatment

Protection Against Elderly Mistreatment Elder Mistreatment Laws Carolyn M. Hay Elder mistreatment is an issue that receives more recognition every year, but what many may not know on the subject are the laws and actions taken against elder mistreatment. In the United States, they take this issue quite seriously and have several acts that contribute to the research and prevention of elder mistreatment. They also provide services to help those who are victims of elder abuse and give justice to those who have been hurt. These laws include the Older Americans Act, the Omnibus Budget Reconciliation Act, and the Elder Justice Act. Each of these acts have their own personal mission and provide services to the elders who have been abused or mistreated, whether at home or in a healthcare setting. What is very concerning is that not many people, adults and elders alike, know about these laws and do not reach out for help when it is there for them. Older Americans should be aware of these laws and what each of them provides in terms of protection from abuse and also justi ce for the abuse done unto them. The first act is the Older Americans Act (OAA) that was passed in 1965. This act is what created the Administration on Community Living (ACL) whose mission is to, â€Å"develop a comprehensive, coordinated, cost effective system of home and community-based services that helps elderly individuals maintain their health and independence in their homes and communities† (Dong, 2012, p. 2152). But what does this entail exactly? Well the OAA gives grants to the states and local agencies for research and community planning programs for aging and elder abuse. The act has four parts to it that relate to elder mistreatment including Titles II, III, IV, and VII. Title II of the OAA states that the ACL must select someone to be in charge of the research, planning, and developing of elder abuse programs. Title III says that states must have a plan for the grants before they can receive them and then provides them with the grant. Title IV allows the ACL to give grant money for outreach progr ams and projects that relate to elder abuse. Lastly, Title VII makes the ACL give grants to state agencies to educate the community on elder abuse, including caregivers and other professionals. This title also makes the state have someone to take care of the legal services associated with elder abuse and protection. Overall, what the OAA act does is mandates these elder abuse programs in the states and provides the funding for them (Dong, 2012, p. 2152-2153). The second act is the Omnibus Budget Reconciliation Act, or known as the Nursing Home Reform Act, and was passed in 1987. This law was made to ensure the highest quality care for the elderly living in nursing homes. â€Å"The law ‘provides federal statutory protection for residents in certified nursing facilities†¦Residents have the right to privacy, information on medical changes, the right to voice grievances without discrimination, and accommodation of physical, emotional, and social needs,†Ã¢â‚¬â„¢ (Watson, 2013, p. 41). Because of this protection, this law is considered to be the most important law that deals with elder abuse. This seems plausible, because many reported cases of elder abuse occur in long term care facilities and nursing homes. This law is substantial because it makes it okay for the elderly living in nursing homes to protect themselves and receive the highest quality care that they deserve (Watson, 2013, p.41). The most recent and last act is the Elder Justice Act, which was passed in 2010 as part of the Patient Protection and Affordable Care Act. This act allows a federal response to elder abuse through community services to help with the prevention, detection, and treatment of it. This act was the first time that Congress addressed elder mistreatment at the federal level. One of the several great parts of this act is the creation of a Nation Training Institute for Surveyors and the provision of grants to the state survey agencies. These surveys are conducted on long-term care facilities for their care of the patients and the health of the residents to make sure that the minimum standards are being met. This is great because these agencies could detect elder abuse in the facility and take necessary action to protect the residents living there. Hopefully this act will lead to bigger and better things in terms of justice for elder abuse in the United States (Colello, 2014, p. 2-9). Now we know what is being done in present time to prevent elder abuse and give justice to those who have been abused, but what needs to be done in the future? First of all, more research needs to be done on the population of the United States to look at the incidence of elder abuse and the risk factors associated with elder abuse. New research should focus on the risk factors associated with the elderly, like dementia, and also the risk factors associated with the abuser, like the work setting. Secondly, the United States must look at elder mistreatment across all cultures and minorities in the country. Again, this research needs to focus on the risk factors and the incidence of elder abuse within each minority. Another factor that needs to be looked at is the rates for which elder abuse is being reported in each minority. With this information we can hope to get a better understanding of elder abuse across the United States, including all of the different minorities and cultures tha t coincide there. With a better understanding, we can raise awareness in all cultures about elder abuse and what can be done to prevent it and give justice to the victims of abuse (Dong, 2012, p. 2153-2154). In conclusion, these three laws are there to protect and give justice to elders that have been abused, and our elderly population should be educated on each of these laws. Each act is associated with elder abuse, but has different actions. The Older Americans Act provides the funding and helps with the planning of elder abuse programs and research in every state. The Omnibus Budget Reconciliation Act, or Nursing Home Reform Act, gives elders the right to receive the highest care in nursing homes and helps to protect them with these rights. The Elder Justice Act allows the federal government to respond to elder abuse through community services that help prevent, detect, and treat elder abuse. With future research, the United States can also help to bridge the gap with elder abuse in the different minorities across the nation and get a better overall incidence rate of elder abuse. These laws help to create better protection for the elderly and with future research and understanding, th e United States may be able to significantly decrease the rates of elder abuse in the country. References Colello, K. (2014, September 3). The Elder Justice Act: Background and Issues for Congress. Retrieved June 28, 2015, from https://fas.org/sgp/crs/misc/R43707.pdf Dong, X. (2012). Advancing the Field of Elder Abuse: Future Directions and Policy Implications.Journal Of The American Geriatrics Society,60(11), 2151-2156. doi:10.1111/j.1532-5415.2012.04211.x Watson, E. (2013). Elder Abuse: Definition, Types and Statistics, and Elder Abuse (Mistreatment and Neglect) Laws.Journal Of Legal Nurse Consulting,24(2), 40-42.

Investigation in Microtubule Dynamic Instability

Title: Investigation in microtubule dynamic instability Introduction Microtubules are important for maintaining cell structure, intracellular transport, formation of mitotic spindle, as well as other cellular processes. Investigation of dynamics of microtubule assembly and disassembly allow us to understand the malfunction of mitotic spindle formation or other cellular processes. This experiment is divided into two parts; we are going to find out the critical parameters for achieving greatest average length of microtubules in part one and achieving the greatest number of microtubules in part two.Principle In this experiment, we used a simulation programme to explore how various factors change the way microtubules grow out from centrosome, and the shrink back. Growth rate, shrink rate, catastrophe rate, rescue rate, release rate, minus end end depolymerization rate, nucleation rate and nucleation site are the factors we can adjust to see how them affects the average length and number of microtubules. The simulation time acceleration is set to 5x real time. Each time a parameter is varied and others are controlled factors.The record is taken when the simulation has reached steady state and graphs are plotted. Results Part1 – How to achieving greatest average length of microtubules Fixed parameter| Shrink rate| Catastrope| Rescue Release| MED| Nuc rate| Nuc sites| Variable Growth rate| 0. 263| 0. 042| 0. 064 0. 024| 0. 8| 0. 02| 180| Result| 1| 2| 3| 4| 5| Mean| 0. 14| 32. 9| 21. 12| 23. 93| 23. 95| 27. 54| 25. 888| 0. 16| 33. 19| 36. 82| 32. 5| 28. 83| 30. 15| 32. 298| 0. 18| 29. 79| 39. 11| 41. 19| 40. 8| 31. 54| 36. 486| 0. 2| 40. 77| 41. 19| 45. 94| 38. 28| 47. 66| 42. 768| 0. 22| 38. 6| 47. 49| 48. 53| 48. 55| 47. 96| 46. 238| 0. 24| 42. 25| 45. 31| 45. 25| 46. 81| 40. 95| 44. 114| Table1 Figure1 Fixed parameter| Growth rate| Shrink rate| Catastrop/ Release| MED| Nuc rate| Nuc cites| Variable Rescue| 0. 12| 0. 263| 0. 042 0. 024| 0. 8| 0. 02| 180| Resu lt| 1| 2| 3| 4| 5| mean| 0. 084| 23. 76| 22. 77| 26. 56| 30. 78| 25. 12| 25. 798| 0. 104| 18. 88| 19. 07| 17. 82| 20. 08| 17. 55| 18. 68| 0. 124| 19. 96| 16. 69| 17. 37| 19. 37| 22. 38| 19. 154| 0. 144| 21. 34| 19. 53| 20. 54| 21. 44| 21. 95| 20. 96| 0. 164| 20. 65| 18. 76| 21. 76| 16. 33| 19. 73| 19. 446|Table2 Figure 2 Discussion Each free tubulin dimer contains one tightly bound GTP molecule that is hydrolyzed to GDP after the subunit is added to a growing microtubules. When polymerization is proceeding rapidly, tubulin molecules add to the end of the microtubule faster that the GTP they carry is hydrolyzed, and the microtubule growth. [1] Varied the growth rate and kept other factors constant, the average length of microtubules should always increase. However, the average length of microtubules rises as growth rate increase from 0. 14 to 0. 22Â µm/sec and stop increasing at 0. 2Â µm/sec. It tends to level off rather than increase at 0. 22Â µm/sec. It means the growth rate is no longer the limiting factor. Some factors other than growth rate, may be the rescue rate, limited the increase of the average length. Rescue rate is the rate at which a shrinking microtubule switches to growing state. We assume the greatest rescue rate, the more the microtubules undergo polymerization. So that the proportion of growing microtubules would increase and the average length rise. Instead of increase, the average length of microtubules drops from 0. 084 to 0. 104Â µm/sec.Increase the rescue rate may trigger the mechanism that lowers the average length of microtubules. It remains at around 20Â µm from 0. 104 to 0. 164Â µm/sec means that that there is no correlation between rescue rate and the average length beyond a point among 0. 084 and 0. 104Â µm/sec. Part2 – How to achieve the greatest number of microtubules Fixed parameter| Growth rate| Catastrop| Rescue Release| MED| Nuc rate| Shrink rate| Variable #nuc site| 0. 12| 0. 042| 0. 064 0. 024| 0. 8| 0. 02| 0. 263| Result| 1| 2| 3| 4| 5| mean| 180| 47| 65| 42| 57| 68| 55. 8| 200| 70| 77| 66| 53| 68| 66. | 220| 71| 73| 86| 70| 68| 73. 6| 240| 82| 88| 85| 81| 84| 84| 260| 90| 93| 80| 81| 84| 85. 6| 280| 87| 107| 100| 97| 91| 96. 4| 300| 90| 101| 110| 92| 96| 97. 8| Figure3 Fixed parameter| Growth rate| Shrink rate| Catastrop| Rescue Release| MED| Nuc cites| Variable nuc rate| 0. 12| 0. 263| 0. 042| 0. 064 0. 024| 0. 8| 180| Result| 1| 2| 3| 4| 5| mean| 0. 02| 62| 57| 49| 54| 50| 54. 4| 0. 04| 95| 107| 85| 80| 86| 90. 6| 0. 06| 103| 110| 107| 113| 114| 109. 4| 0. 08| 120| 99| 112| 113| 115| 111. 8| 0. 1| 124| 134| 126| 116| 113| 122. 6| 0. 12| 120| 131| 130| 119| 136| 127. | 0. 14| 136| 128| 127| 130| 136| 131. 4| Table4 Figure4 Discussion Centrosomes contain ring-shaped structures formed from ? -tubulin, and each ? -tubulin ring serves as the starting point, the nucleation site, for the growth of one microtubule. The nucleation site acts as a preexisting microtubule structure for -tubulin dimers assembly. [1] We assume the more the nucleation site, the more the microtubules present. According to table3, the number of microtubules is always increasing with the number of nucleation site. There is no sign of level off or decline of the curve.It always is the limiting factor of the number of microtubules. The nucleation rate is the rate at which new microtubules are nucleated at the centrosome. The number of microtubules should be raised if the nucleation rate increase since new microtubules generated. Indeed, the number of microtubules is raised as the nucleation rate increased. From 0. 02 to 0. 06Â µm/sec, the increase of microtubules is sharp and starts to slow down afterward. The trend shows that the curve would level off at certain level eventually. It means there are some factors other than nucleation rate control the number of microtubules.The number of nucleation site may be the limiting factor as all nucleation sites are occupied by the microtubules, so that n o new microtubules generated. Limitations In actual cell, the number of tubulin dimer is limited. This factor is not shown in this simulation programme. The temperature and the pH may affect the configuration and polymerization of the microtubules. There are some microtubules not attached to the centrosome, but present in cilia and flagella. It is not clearly stated by the simulation programme whether these microtubules is counted. ConclusionsBesides the growth rate, there are other limiting factors controlling the average length of microtubules. We cannot achieve the greast average length of microtubules by consider growth rate is the only factor. We found that we should keep the rescue rate at 0. 084Â µm/sec or below. Also, more information about the rescue rate below 0. 084Â µm/sec should be obtained. Both nucleation site and nucleation rate are the factors controlling the number of microtubules. But the nucleation site is more critical than the nucleation site. The above show the nucleation rate is restricted by other factors but the nucleation sites does not.We should examine another set of data by varying the nucleation rate with more nucleation site. If the plateau of new obtain curve is above the original curve, nucleation site is limiting factor of the number of microtubules. Similar experiment should be established with different combination of parameters in order to obtain the best curve. In short, there is not enough information for us to draw conclusion for how to achieve the greatest average length and greatest number of microtubules unless we obtain more data. Reference 1. Alberts et al,. (2010) Essential Cell Biology, 3rd Garland Science, p. 579-580