Erythropoietin Essay Essays - Hematopoiesis, Growth Factors

Erythropoietin Essay Introduction. Erythropoietin is a glycoprotein that is produced primarily in the kidneys in adults and, to a lesser extent, in the liver. It behaves like a hormone, regulating the level of erythropoiesis, and keeping the RBC count within a narrow range It is used widely in medicine as a treatment for a number of serious illnesses, ranging from types of anaemia, to the treatment of certain types of cancer, and also in the battle against AIDS. Unfortunately certain athletes, who will do anything to win, have realised its ergogenic benefits, and also the severity of its misuse. Regulation of Erythropoietin Production. In the kidneys, erythropoietin is produced in fibroblastoid interstitial cells in the inner renal cortex, while in the liver, the hormone is produced by both hepatocytes and interstitial fibroblastoid cells. Although a variety of growth factors influence erythroid progenitor cell proliferation, erythropoietin is the most important, and erythropoiesis cannot continue in its absence. Among the haematopoietic growth factors, erythropoietin is one of few that behaves like a hormone. It is unique because its production, under normal circumstances, is controlled solely at the level of its gene, by tissue hypoxia and not by the absolute number of circulating erythrocytes. Hypoxia is the sole physiologic stimulus for erythropoietin production, and an excess of oxygen suppresses its production but never completely. Some facts about EPO. (Birchard K, Lancet 1998; 352: 42.) ? Neither age nor gender influences the plasma erythropoietin level, ? Plasma erythropoietin is constant in a given individual, ? Erythropoietin production is regulated at the level of its gene, ? Hypoxia is the only physiologic stimulus for erythropoietin production, ? There are no pre-formed stores of erythropoietin, ? There is only one form of circulating erythropoietin Following production in the kidneys and liver, erythropoietin travels to the bone marrow to interact with specific haematopoietic progenitor cells where it maintains RBC production. What evidence is there that people take erythropoietin? There are two current tests for EPO abuse. Prior to these however was a Haematocrit count. If the count was too high then the athlete in question would not be allowed to compete, but there would be no ban, as the test didnt actually prove that they were taking an illegal substance. The first of the current tests is to check the urine for recombinant EPO (an artificial type made by drug companies). This can easily be overcome by stopping the administration of EPO two or three weeks prior to competition. This way, the high levels of EPO will be out of the system, yet the large benefits of it will last for a number of months. The other test is a blood test. EPO injections produce high quantities of immature RBCs in the blood, but again this can be over come by knowing how long it takes the immature cells to mature and stopping the injections enough in advance of the competition. The way around this is obviously random testing out with the events, but this is not always viable. What is the rationale that leads people to take it? Athletes use erythropoietin to stimulate erythropoiesis, Until now, detection was a problem because erythropoietin is normally found in urine, and blood-sample analyses indicate only that erythropoiesis had been stimulated, not that drug use is to blame. EPO regulates erythropoiesis, keeping the packed-cell volume within a narrow range. Muscles of elite athletes need a lot of oxygen. A higher packed-cell volume can be achieved by injecting EPO. A higher packed-cell volume increases delivery of oxygen to tissues and enhances performance during competitions that require stamina, such as long-distance cycling and cross-country skiing. Theoretically, a person could continue indefinitely to increase his/her work rate and remain in an aerobic state as long as the blood can continue to supply sufficient oxygen to the increasingly worked muscles. A greater blood volume increases the amount of blood returning to the heart and therefore will allow a greater amount to be pumped out each heart beat, allowing the heart to pump more blood without increasing the heart rate. This is known as the Frank-Starling mechanism. Red blood cells are an important acid buffer as well. With more blood cells you should be able to buffer more lactic acid. This means that EPO use may boost both the aerobic

Free Essays on Tests

What is at Stake? When students graduate from high school, the public expects that each student will possess the skills to be successful at either work or secondary education. We know however, that not all students meet this expectation. A 2000 report from the Employment Policy Forum reported, â€Å"that is many as 70% of students entering the workforce do not have simple writing skills† (Workforce Preparation 1). In an effort to improve student achievement, (State Law 2, statutes of 1999), authorized the development of the California High School Exit Exam (CHSEE). Seniors in the class of 2004 will be the first California public school students who must pass the CHSEE in order to receive their high school diploma (Rubin, par. 5) Advocates say exit exams will motivate students and teachers to reach higher standards, therefore improving student achievement. Critics contend, however, that exit exams have no educational value and do not answer the question of how to best measure student learning. Furthermore, they argue that these high stakes tests will lead to higher dropout rates and do not ensure that students have an opportunity to learn the material being tested (Hicks 1-2). Graduation decisions should be based on many factors; one test should not be the sole determinant of any major decision. Proponents argue that high school exit exams are a crucial key to educational reform. A statewide exam will set uniform expectations and use the same evaluation instruments for all students. The CHSEE will hold all students accountable to the same with graduation requirements and hold schools accountable for student performance. Supporters of the CHSEE make strong arguments for the use of exit exams. However, whether these exams are accurate indicators of a student's abilities, is highly debatable. Stanford University's Linda Darling-Hammond writes, â€Å"there is no evidence high stakes testing improves school quality. Indeed, th... Free Essays on Tests Free Essays on Tests What is at Stake? When students graduate from high school, the public expects that each student will possess the skills to be successful at either work or secondary education. We know however, that not all students meet this expectation. A 2000 report from the Employment Policy Forum reported, â€Å"that is many as 70% of students entering the workforce do not have simple writing skills† (Workforce Preparation 1). In an effort to improve student achievement, (State Law 2, statutes of 1999), authorized the development of the California High School Exit Exam (CHSEE). Seniors in the class of 2004 will be the first California public school students who must pass the CHSEE in order to receive their high school diploma (Rubin, par. 5) Advocates say exit exams will motivate students and teachers to reach higher standards, therefore improving student achievement. Critics contend, however, that exit exams have no educational value and do not answer the question of how to best measure student learning. Furthermore, they argue that these high stakes tests will lead to higher dropout rates and do not ensure that students have an opportunity to learn the material being tested (Hicks 1-2). Graduation decisions should be based on many factors; one test should not be the sole determinant of any major decision. Proponents argue that high school exit exams are a crucial key to educational reform. A statewide exam will set uniform expectations and use the same evaluation instruments for all students. The CHSEE will hold all students accountable to the same with graduation requirements and hold schools accountable for student performance. Supporters of the CHSEE make strong arguments for the use of exit exams. However, whether these exams are accurate indicators of a student's abilities, is highly debatable. Stanford University's Linda Darling-Hammond writes, â€Å"there is no evidence high stakes testing improves school quality. Indeed, th...

Symbolic Interaction Essay Example | Topics and Well Written Essays - 500 words

Symbolic Interaction - Essay Example The specific events where the meanings are applied could only be clearly visualized by the researcher by immersing himself in the situation. It would be extremely difficult to determine the meaning of things to people and their interpretation of it if the symbolic interactionist has not observed how the meaning came about. The researcher would have a better view of the person’s application of the meaning if he sees the circumstance where it is applied. 2. The classes that I like are Speech, and Geography. Using the â€Å"Looking Glass Theory of Cooley, I can say that one reason that I like Speech is because when I was young, my parents and some of my relatives often told me that I can be a very good speaker. They viewed me as someone who is very confident when speaking in front of a lot of people. Even during my elementary and high school days, I was often chosen by my teacher to represent the class in declamation contests because of how well I am able to express myself. This perception of other people towards me during my younger days somehow became instilled in me. I came to believe that I have a talent in speaking in front of a crowd and that I can express myself well verbally. I also like Geography class.

Reflective log on communication Essay Example | Topics and Well Written Essays - 6000 words

Reflective log on communication - Essay Example In his writing The Reflective Practitioner, How Professionals Think In Action, Basic Books, Schon highlight the significance of building a reflective dialog in all the environments. As cited by a number of authors, reflective practices are very important tool in today’s world especially in communication and interaction. Managers, leaders and team members encounter a number of challenges while dealing with their customers, clients, staff, and competitors. Besides, the environments of operation usually pose another great threat to the success of managers. For instance managers in the insurance industry embattles with reflective challenges in handling the claims of their clients. Internal staff control is another big shoe for managers as they try to bring together unity and profitability within the working environment. For a corporation to remain profitable and competitive, sales volume is a critical tool. However, achieving the company’s sales target entails conducting an d evaluating the potential customer base, satisfaction and customizing individual needs of the potential clients. Reflective practice is therefore an essential tool in achieving the above mentioned goals. Reflective log practice helps in analyzing clients’ needs and demands. ... A number of models have been proposed to explain the concepts of reflective practices. Schon (1974, p.56) Double Loop Learning) identified single loop and double loop as the most common forms of reflective learning. The theory was founded on amendments and recognition of perceived errors or faults. In the single loop reflective learning, in a more error prone period, companies only embarks on depends on their current strategies to tackle the company crisis and challenges. Double loop learning covers for personalized objectives, goals and strategies which are very comprehensive. It entails problem solving techniques, outsourcing the cause of the problem, advancing prevention mechanism, and making recommendations on possible future strategies for the company prospect. Adaptation of the single and double loop learning model by Argyris and Schon Schon introduced the concept of Reflection-in-action and Reflection-on-action in later time. Reflection-in-action can be explain as the ability of a practitioner to ‘think on their feet’, when there are the problem, thinking ahead, making analyzing, base on my experiencing to getting the point of view in it, after all process to making critically responding. Reflection-on-action on the other hand is the idea that after the experience a practitioner analyses their reaction to the situation and explores the reasons around, and the consequences of, their actions. This is usually conducted though a documented reflection of the situation. Adaptation of the reflective model by Schon Learning log table: (Case Study) Communication Breakdown in an Organization Title Sep 2012 conflict with claims department Meeting with my subordinate -The client apply a medical claims when who is out of

Windows Vs Linux Comparison

Windows Vs Linux Comparison Linux and windows operating systems are software with programs and information needed to run and monitor the computer programs. An operating system is one of the most important computer programs which a computer can not run without them. Even though they are both important for computer programs, Linux and windows are two different operating systems and they have different features which basically differentiates them. (Web msdn.microsoft.com, online)[26th September 2010] This project will basically focus on the difference between Linux and windows, the importance of Linux and widows operating systems, the top 6 most important difference between Linux and windows and a summary table of the difference and similarities of the two and it will also cover the background of the two operating systems. OBJECTIVES This major of this project are; To discuss the difference between Linux and windows To discuss the importance of the two operating systems To discuss the top 6 most important difference between Linux and windows BACKGROUND STUDY Windows was introduced in 1983 by Microsoft and it has been there most success as it has been dominating other computer operating systems and it is the most preferred operating system by many people. .Ever since 1983 Microsoft has been improving windows operating system with the growth of technology. (Micheal, 2004, online) [26th September 2010] Linux operating system was introduced in 1991 by a student of Helsinki University (Linus Torvalds). The Linux operating system was derived from UNIX operating system. It was called the GNU/Linux because it is a combination of the Linux as the kernel and GUN system. The Linux operating was made free to everyone and also Linus Torvalds made the source codes available in the internet for educational purposes and also for improvements. Ever since Linux operating system was introduced 1991 the internet has been promoting the development of the Linux operating system, nowadays many companies are giving Linux operating system there support through the internet and this shows how successful Linux is growing. (Micheal, 2004, online) [26th September 2010] FINDINGS Key words; OPARATING SYSTEM: It manages and controls the hardware components for a computer. RAM: Random Access Memory. THE DIFFERENCE BETWEEN LINUX AND WINDOWS OPARATING SYSTEMS This two operating systems where developed to achieve the same important aim being to provide computers with a software that has different programs to help run a computer. Considering the two main aspects of Information Technology being Hardware example Device Driver, Software example Software Applications, this two are different. . (Web msdn.microsoft.com, online)[26th September 2010] DEVICE DRIVER Most of Linux operating systems are built-in support for a device and it is not easy for one to add it in if they are using other distributions without the built in devices but for windows users is much easy for one to do it. THE SOFTWARE APPLICATIONS Windows and Linux operating systems both have similar softwareà ¢Ã¢â€š ¬Ã¢â€ž ¢s like the internet browser, email client etc but looking at the important ones like the video mixing and others windows provides better than Linux. PORTABILITY The feature of portability is the one which boosts the Linux operating system to be better than windows as one can store an operating system to a CD and use it to boot from it with all features and softwareà ¢Ã¢â€š ¬Ã¢â€ž ¢s needed and this CD is called a liveCD where as windows does not have this feature as they are trying to avoid sharing of illegal copies of there operating system. SECURITY Linux has an excellent security feature which is free from viruses and it is not easy to be hacked unlike windows which has many viruses and is easily hacked The most important top 6 difference between the two are; The Linux operating system provide its source code to the community through internet for them to improve it or even add more features to it, to make your computer work better where as windows does not provide ay source code to any one. All versions of Windows are provided by one company being Microsoft where as Linux is distributed by different companies like REDHAT, SLAKWARE etc. Linux operating system is very cheap for server uses and free for home users and one can use it as many as they want where as windows is very expensive and it also limits one to use the operating system with activations Linux operating system has an important feature called multitasking which enables one to run many process at ones where windows will limit one. The Linux operating system a symbol of a penguin for identification where as windows use a flag of four colures which are red, green, blue and yellow. Windows needs lot of memory(RAM) to run compared to the Linux operating system SIMILARITIES Linux and windows both hide operating system files in the directory which are not to be used by the user. They both support one scripting language which is the PHP and it can be used in windows and Linux Both Linux and Windows are multi operating systems They both support the use of device ports like; USB, parallel and serials They both allow user to choose there file security, which means they can share files in both operating systems with the use of networks. (Web odetocode.com,online)[26 September 2010] Windows and Linux operating systems are different as shown in the document and there many more different features of this two which are not listed above. The difference between the two operating systems The table below shows the difference between the two operating systems being the Linux and Windows (Web techrepublic.com) [26th September 2010] FEATURES LINUX WINDOWS Variants Red Hat, caldera, linuxPPC, SuSE Windows 2000, windows XP ,Windows vista, windows 7 Licensing FREE EXPENSIVE Performance Uses less memory so ità ¢Ã¢â€š ¬Ã¢â€ž ¢s faster. Uses less memory but more that Linux does so ità ¢Ã¢â€š ¬Ã¢â€ž ¢s a bit slow Security It is much save as it provides a every excellent security It easily hacked as does not have a very tough security Safety It is much safe as they are no known viruses for it. There are millions of viruses for windows operating system maybe it because it worldly used. CONCLUSION This report has compared Linux and windows by providing the difference and the similarities between the two. The two operating systems are both important to computer users and none of them is different to another, but we can say they are just fundamentally different to each other. (Web ibm.com) [26th September 2010] They are both operating systems and an operating system is one of the most important computer applications as it manages data in it, provides the users with the interface to use the computer and it also makes the computer to run which is one of the most important point of having an operating system on your computer.

walden two Essay -- essays research papers

Walden Two   Ã‚  Ã‚  Ã‚  Ã‚  In B.F. Skinner’s Walden Two, Skinner presents many positive changes to society in his utopia, such as: division of labor, encouragement of perusing your own interests in education, and absolute equality.   Ã‚  Ã‚  Ã‚  Ã‚  In Walden Two, a member is paid in credits that are required by the society. Each person earns a certain amount of credits per hour for every job they do. Everyone is expected to work to receive 4-6 credits for one day. The amount of credits-per-hour depends on the job. A more physically demanding or unpleasant job would receive more points then something less taxing. This is an effective way or contracting society because it has people work enough to get the necessary work done to drive the society without overworking and tapping out the worker. When Castle and Frazier discuss whether a community can survive on such little work, we understand that the people who are working are working with intent and without distractions and not under distracting supervision. It is also useful because it allows people to choose how to spend their time. If they would like to get their work down quickly by doing a more challenging job, that is their choice and they are not being m ade to do so. This also allows people to freely move around with jobs. They are not locked into one job for the rest of their life. If they do not like it, they can sign up for a new job tomorrow. This allows you to pursue your interests wit...

Origins of Cold War Essay

The Cold War was one of the most important historical events in the world, which had created a great impact that is still felt within the international community. The United States and the Soviet Union became the two most influential and powerful forces during this era. The relationship between the two former allies was anchored on political, ideological and economic interests, which at the end of the Second World War came as threats wherein developed bitterness and rivalry for power over the years (Hoesel, 1992). The Cold War which has been referred to as the period of â€Å"elusive peace† dictated that the United States of America as the world’s leading hegemonic power, with the defeat and disintegration of the Soviet Union at the end of the war. The Cold War indeed has been a conflict involving former allies, United States of America and the Soviet Union due to the difference in political ideologies held by the two superpowers (Nosotro, n.d).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The difference in political ideologies caused the development of animosity and hostility between United States and the Soviet bloc. The United States having been supportive of capitalism clashed with the communist Soviet Union (Nosotro, n.d). Although there had been no direct confrontation between the two world superpowers, indirect confrontations among the United States and Soviet allies were enough to assess the impact of the Cold War. Economic, political and military affairs of the two states and their allies underwent massive policy changes in order to keep abreast with the happenings during the Cold War. The â€Å"arms race† was one of the most important indirect military offensives that took place between United States and Soviet Union, both states trying to produce more sophisticated weapons ahead of the other. This in turn created a great impact on the two states’ economic and social services sectors (Kishlansky, 2005).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   As such, the political allies of both United States and Soviet Union were also affected as both governments of the two states worked towards spreading influences in less developed countries. The series of decolonization became rampant and emphasized in regions such as Asia, Latin America, Africa and Middle East. And as such, the conflicts brought by the Cold War were instantly shifted and transmitted within these areas (â€Å"The Elusive Peace The Cold War,† 1992). References Hoesel, F.V. (1992). The Soviet Union and the United States. Soviet Archives Exhibit. Retrieved August 23, 2008, from http://www.ibiblio.org/expo/soviet.exhibit/intro2.htmls Kishlansky, M. (2005) Civilization in the West, Volume C (since 1789), 7th edition. Nosotro, R. (n.d). The cold war. Hyperhistory. Retrieved August 23, 2008, from http://www.hyperhistory.net/apwh/essays/big/w30coldwar.htm The elusive peace the cold war. (1992). History World International. Retrieved August 9, 2008, from http://history-world.org/coldwar.htm