Thursday, November 28, 2019

Student Role in Politics Essay Example

Student Role in Politics Essay Subject: Research By: Making a Difference, Not a Statement: College Students and Politics, Volunteering, and an Agenda for America Peter D. Hart Research Associates 1724 Connecticut Avenue, NW Washington, DC 20009 April 2001 Date: From February 24 to March 2, Hart Research surveyed a national representative sample of 809 students in four-year colleges and universities; this research, conducted on behalf of the Panetta Institute, gauges students’ views of and involvement in civics and politics. This report summarizes our key findings. The margin of error is  ± 3. 5% for the overall sample and higher for specific subgroups. Forty years ago, something began to stir on the nation’s campuses. In March 1961, President John F. Kennedy, sensing the potential idealism of the nation’s youth, signed an executive order creating the Peace Corps, and a few months later, the first cohort of Peace Corps volunteers embarked for Africa. That same year, college students traveled south to join the Freedom Rides, risking life and limb for the civil rights cause. It was the beginning of a youth movement that ultimately changed the face of America, as it touched everything from race relations to women’s rights to war and peace. We will write a custom essay sample on Student Role in Politics specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Student Role in Politics specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Student Role in Politics specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Four decades later, could students once again provide the energy and idealism that drive social and political change? The results of our national survey among college students suggest that the potential is indeed there. Indeed, the civil rights and women’s movements are now a source of inspiration. And if this potential is realized, this generation is clearly poised to move the country in a progressive direction. In their issue preferences and political leanings, the youth of Generation Y embrace a progressive agenda while rejecting the anti-government cynicism of their Generation X forerunners. Yet, only a fraction of this great potential has been realized so far. Unlike their predecessors four decades ago, today’s college students enjoy the legal right to vote, but only a small minority of Americans age 18 to 21 exercised that right in 2000. These young people care about the issues of the day, yet few believe that working on a political campaign or contacting their congressional representative, for example, can help make society better. They say they want to contribute to their society and make a difference, but most spurn government service as a career option. Their values and priorities seem disconnected from their level of political engagement. Certainly, neither presidential candidate managed to connect with this generation. Today’s students are simultaneously progressive and apolitical; they embrace many government solutions, but evince little interest in government itself. Nevertheless, the survey results indicate that it is possible to get college students involved in the nation’s political life. Indeed, today’s generation of students is like tinder awaiting a spark. New political leadership, making the right kind of appeal and challenging young people to get involved as President Kennedy did in 1961, could once again awaken a powerful response on the nation’s campuses. I. College Students’ Current Outlook 1. Today’s college students are progressive in their views. College students’ agenda for the nation is strongly progressive. Among all the policy priorities tested in the survey, the top three are improving schools by hiring teachers and reducing class size (85% very top or high priority), strengthening and preserving Social Security (76%), and providing assistance to low-income families (73%). The three lowest priorities are strengthening the military (34%), reducing the size of government (23%), and allowing oil exploration in the Alaskan Arctic Wildlife Refuge (21%). Looking back at our history, today’s college students identify with progressive social movements. Overwhelming majorities feel that the civil rights (89%) and women’s rights (78%) movements did a great deal or quite a bit to make American society better. Smaller majorities say the same about the environmental movement (58%), human rights organizations (56%), and the Democratic Party (57%). In contrast, far fewer believe that the Republican Party (45%), the war on drugs (40%), the campaign for teen abstinence (29%), or the anti-tax movement (23%) has changed things for the better. In anticipating the future, many college students look far afield and point to progressive solutions to both international and domestic problems. A majority (59%) believe that most problems facing their generation will be domestic in nature (e. g. , Social Security), but a significant proportion, 37%, think that most will be international in scope. This outlook is reflected in the majorities of students who believe that the following global issues should be either the top priority or a high priority for Congress and President Bush to address: dealing with the worldwide AIDS epidemic (70%), promoting human rights abroad (64%), and cracking down on imported goods made in sweatshops or with child labor (59%). College students’ political affiliations provide further evidence of the progressive environment on most campuses; by a considerable 48%-to-33% margin, students identify more with the Democratic Party than with the GOP. To a lesser extent, this progressive viewpoint is evident in their vote—Gore edged out Bush by 46% to 42% among those who reported voting (another 9% supported Nader). And had they voted, non-voters with a preference among the candidates would have supported Gore by an even larger margin: Half (52%) would have voted for him over Bush (38%); 7% would have voted for Nader. Nevertheless, their votes make clear that neither of the major party candidates managed to connect with these younger voters. Gore, in particular, had the most to gain from the political disposition of the majority students and the issues they believe are important. Yet, while Democrats enjoy a 15-percentage-point advantage over Republicans on campuses nationwide, Gore held only a 4-point lead over Bush in the college vote. 2. Students do not see politics as a primary means of bringing about positive change. Young people are political voyeurs—they watch, but they don’t participate. Students clearly question the efficacy of getting more deeply involved in the political process. Only 12% believe that volunteering on a campaign is a way to bring about a lot of change (40% say some change). Only half that proportion, 6%, actually participated in a federal, state, or local political campaign during the 2000 election cycle. Students also question the effectiveness of other forms of political action. Only 17% say that attending a demonstration can bring about a lot of change (46% say some change). And as far as contacting an elected official about an issue, only 13% to 17% (depending on whether they are e-mailing or writing) say that this is a way to bring about a lot of change. Because students are not sure that their individual involvement will make much of a difference, most students choose not to get involved other than in the easiest, most convenient ways. Although 56% tell us that they have signed a petition, only 19% have participated in a demonstration, and only 18% have written to a member of Congress. 3. The 2000 presidential election may have sparked an interest in politics and an appreciation of the importance of voting. If the election had a single legacy, it would be arousing this generation’s interest in the political process. Students took an active interest in last year’s presidential election: The vast majority (88%) reports checking the latest news at least once a week during the election. Two in five (42%) say they kept up on the news every day, whereas only 6% say they checked the news no more than once a month. One of the most compelling findings from this research is the respect that students say they have for the vote, which perhaps is a result of the historically close election and the equally historic controversy surrounding the Florida recount. A strong majority (84%) believe that voting in a presidential election is a way to make a difference: 47% say that it can bring about a lot of change, and 37% say that it can effect some change. For most students, voting is far more effective in bringing about change than is volunteering on an election campaign, as only 12% say that the latter can bring about a lot of change. The power of one’s vote is recognized particularly among freshmen (88% a lot/some change), women (87%), and students affiliated with one of the major parties (84% Democrats, 85% Republicans). 4. Students believe in and prefer the direct benefits of volunteering. What’s the alternative to politics? An overwhelming majority (86%) of students tell us that doing volunteer work for groups that help the needy is a way to bring about needed change (50% a lot of change, 36% some change). Most students believe that volunteer programs—more so than the two political parties—have made society better. Solid majorities say that youth-mentoring programs, such as Big Brother/Big Sister (68%); private charities (66%); and groups like AmeriCorps (59%) make a great deal or fair amount of difference toward the betterment of society. Because they believe that getting involved in volunteer programs is a way to help their local communities, most students volunteer during their time in college. A large majority (68%) say that they have been involved in volunteer or other types of charitable activities. Sixty-three percent have volunteered at a local school, hospital, or neighborhood center; 38% have been tutors or mentors; and 27% have helped raise funds for a local cause. Volunteering has become part of the college experience. Among students who have gotten involved in their communities, two in five (39%) have volunteered through a program offered by their college or university. Alternatively, they have worked with an organization (13%) or a religious group (12%) with which they are affiliated. The value that students find in volunteerism is evident in their willingness to consider a longer-term commitment to an organization. Nearly three in four (73%) students would consider volunteering for either Habitat for Humanity (42%), the Peace Corps (21%), AmeriCorps (7%), or VISTA (3%) after they finish college or during a break. The vast majority (83%) of students also says that working for an issue organization is an effective way to make a difference. Most students admire progressive issue organizations for their contributions to society: 59% believe that Mothers Against Drunk Driving (MADD) and other groups promoting alcohol awareness have made a great deal or fair amount of difference; 56% say the same of international human rights’ groups such as Amnesty International. 5. Young people are committed to making a difference, but not through government service. Half (49%) of all college students say that in choosing a career, it is very important (a 9 or 10 on a 10-point scale) that it contribute to society. Yet, only about half as many (26%) tell us that they are very or fairly interested in government service; two in five (42%) say that they have no interest whatsoever in working for the government. In part, students question the government’s ability to make changes for the better. While 50% believe that doing volunteer work to assist the needy can bring about a lot of change, only 20% say the same about choosing a career in government. As a result, even those who put a premium on a career’s potential for making a difference are unwilling to consider government service; among this group, only 26% say that they would be interested in working for the government. Sixty-four percent of students say that providing financial aid or forgiving student loans might be an incentive to participate in public service. Three in ten say that it might help to have a parent or professor encourage them to participate. 6. Today’s students don’t hate the government, but they feel disconnected from it. Generation Y is not hostile toward government. Only 23% say that smaller government should be a top or high priority for the nation; 68% say that they are satisfied with the country’s political leadership; and only 38% feel that a candidate’s working to change the way things are done in Washington is a very important quality. If anything, Generation Y would like to see more from government: 85% say that hiring more teachers and reducing class sizes should be a top or high priority for Congress and President Bush; 76% believe that government should be strengthening and preserving Social Security; 73% want government to assist low-income families with children; and 69% say that the President and Congress should put prescription-drug coverage for seniors on the national agenda. Students don’t know what to make of government. When asked whether they think about government as the government or our government, 60% say the government and 39% say our government. Of course, the degree to which students (and presumably most Americans) feel any ownership of government may depend on who is in power—47% of Bush voters and 46% of Republicans say our government, compared with only 36% of Gore voters and 35% of Democrats. II. How Can We Engage Young Adults in Politics? tudents’ concern about and willingness to help the vulnerable and disadvantaged demonstrate that they can be engaged. But this is not the 1960s—they are concerned more with the impact they will have and less with the ideal they will serve. If candidates, political parties, and social-change organizations hope to involve young people, they should understand the following: 1. Young people want to make a difference, not just a statement. While today’s generation is drawn to ideals, whether in voting or volunteering, it also wants tangible results. Asked what they would most like to see in a political candidate, half (50%) of college students say that it is very important that they be idealistic and stand up for principles, but more (63%) say that it is very important that candidates be practical and realistic. This pragmatic orientation is reflected in the 50% who believe that volunteering in one’s community can bring about a lot of change; only 17% say the same about participating in demonstrations. Three in four students say that people can make a difference just by living their lives in a way that is consistent with their social and political values. Thus, to inspire college students, political leaders must offer a vision and back it up with concrete action. 2. Students are looking for honest leaders who understand young people’s concerns. This generation has tremendous respect for the gains made by the civil rights and women’s movements. Hence, today’s students want candidates who can address similar challenges as well as be forthright in face of great adversity. They want candidates who are honest (65% say this quality is very important) and who say what they think, even if their positions are unpopular (51%). Nearly half (46%) of students feel that a candidate’s understanding of their values is very important. 3. Provide avenues for individual empowerment and celebrate the power of voting. Today’s students are empowered by volunteering because they believe their individual efforts contribute to a larger cause that makes a difference. Students do not feel the same way about volunteering for a political campaign, however. But the 2000 election left a legacy, a legacy whose effects may be felt for quite some time to come: Students now believe strongly that their individual votes truly count. We must build on this belief by giving young people ways to participate in the political process (e. . , aggressive voter registration and GOTV). 4. Build a bridge between direct service, and politics and public service. Many have already volunteered in their communities, and even more are open to working with Habitat for Humanity or the Peace Corps after graduation. Cultivate their willingness to act on their beliefs, not as an alternative to political engagement, but as an additional reason to either participate in the political process or make a career of public service. The challenge for political leaders and parties is to show young people who are willing to help Jimmy Carter build affordable housing, for example, that public policy and government can accomplish even more, or show Peace Corps volunteers that only the world’s governments have the resources to tackle global problems such as AIDS or exploitative child labor. The potential is already there—students want a government that does more, whether it is hiring more teachers and reducing class sizes or providing assistance to low-income families. 5. Support and encourage young women. Female students (59%) are much more likely than male students (39%) to say that making a difference is a key consideration in choosing a career, and they are more likely than male students to believe that volunteering for a campaign can make a big difference (59% vs. 43%). Moreover, female students already are more involved than their male counterparts—by 35% to 23%, women are more likely to have boycotted a product because of a manufacturer’s wrongdoing, and by 72% to 64%, women are more likely to have volunteered in their community. Yet, women are much less likely than men to say that they would seek elected office: Only 24% of women, compared with 39% of men, report any interest in running for a federal office, and just 24%, versus 43% of men, are interested in running on the state or local level. And while 31% of men say that they are very or fairly interested in a government career, the same can be said of only 21% of women. Young women’s commitment and idealism is there, but it has not yet been linked to politics or public service. They need role models and support. . To reach this generation, go on-line. The attention that many students paid to the election may have been facilitated by the Internet. While television was almost certainly their chief news source about the election (51% say they get most of their political information from TV) a significant proportion also looked to the Internet. Three in ten (29%) say they follow the latest news about politics and civic affairs on-line. Of those studen ts who followed the presidential election each day, 35% say they rely on the Internet for their news. Of those who checked the news once a week or less during the election, only 23% say that most of their news comes from an on-line source. In fact, the Internet has surpassed the newspaper as a chief news source on most college campuses—just one in five (21%) students say that they get most of their news from a city or national newspaper. 7. Parents must lay the groundwork. Ideally, college is a place where young people are on their own for the first time; it’s a place where they can begin to express themselves politically or choose whether to volunteer in their community. On many if not most campuses, students will have the opportunity to see speakers or authors address political issues; they will be asked to sign petitions for a range of causes; they will witness or even participate in demonstrations; or they may become a volunteer through a program offered by their school or an on-campus organization. Whether students take advantage of these new freedoms depends in large part on their parents. When children grow up discussing politics with their parents, they grow up to be far more interested and involved, both in the political process and in their community. Half of all students say that while they were growing up, they discussed politics with their parents very or fairly often; 39% indicate that they rarely did so; and 11% say that they never discussed politics at home. Of those college students who regularly discussed politics with their parents, 50% report checking the latest political news every day during the 2000 election, compared with only 34% of those who grew up in households where politics was not a topic of conversation; 10% of those reared on politics have volunteered on a political campaign, compared with only 2% of students from apolitical households. In addition, young people raised on politics are more likely to believe that a career in government or public service leads to change (24% major change, 47% some change); among students in non-political households, only 16% believe it would make a major change, and 50% say it would bring about some change.

Sunday, November 24, 2019

Free Essays on Leighton - Voctiorian

Frederic, Lord Leighton was - and still is - an important and influential Victorian artist. During the Nineteenth century, Leighton reigned as one of the most fashionable and significant painters of his time. Indeed, he was so well regarded as a painter that he was made President of the Royal Academy in 1878. And the reason that Lord Leighton was so successful during his lifetime is simple - his paintings brilliantly captured the Victorian nostalgia and longing for the glorious "Golden Age" of ancient Greece and Rome. In classically inspired works such as Clytie, Idyll, and Greek Girls Picking up Pebbles by the Sea, Leighton depicted an idealized vision of the past that perfectly appealed to the sensibilities of the time. Combining a flawless painting technique with a keen sense for color and composition, the artist created some of the most beautiful - and memorable - images made during the Nineteenth century. See for yourself, and learn more about this remarkable painter by selecting one of the links to his works above.... Free Essays on Leighton - Voctiorian Free Essays on Leighton - Voctiorian Frederic, Lord Leighton was - and still is - an important and influential Victorian artist. During the Nineteenth century, Leighton reigned as one of the most fashionable and significant painters of his time. Indeed, he was so well regarded as a painter that he was made President of the Royal Academy in 1878. And the reason that Lord Leighton was so successful during his lifetime is simple - his paintings brilliantly captured the Victorian nostalgia and longing for the glorious "Golden Age" of ancient Greece and Rome. In classically inspired works such as Clytie, Idyll, and Greek Girls Picking up Pebbles by the Sea, Leighton depicted an idealized vision of the past that perfectly appealed to the sensibilities of the time. Combining a flawless painting technique with a keen sense for color and composition, the artist created some of the most beautiful - and memorable - images made during the Nineteenth century. See for yourself, and learn more about this remarkable painter by selecting one of the links to his works above....

Thursday, November 21, 2019

Effect of lowering temperature in tissue and organ preservation Research Paper

Effect of lowering temperature in tissue and organ preservation - Research Paper Example Enzymes in tissues and organs dissociate through inactivation because of cold-related propensities. Some enzymes are intrinsically affected by cooling. Reducing the temperature increases trans-membrane diffusion of solutes from minute ions to expanded molecules (Fuller et al., 2014). Hypothermic Machine Perfusion Preservation This preservation method was developed to enhance the quality and time of preservation of kidneys. The method allows the movement of oxygen to the tissues to enable ATP synthesis. The perfusion of the fluids aids in the transportation of oxygen through the fluids to essential areas of the organ (In Kirk, 2014). The perfusion process is positively impacted when the temperatures are regulated to certain limits. Even though the reduction of temperatures can have certain side effects, the preservation viability is immensely enhanced. Oxygen Persufflation The method employs gaseous oxygen in improving the viability of an organ for transplant. For instance, oxygen is bubbled through a vasculature that is then released through minute proliferations at the organ's surface. The method is effective in liver preservation because of its homogenous distribution of oxygen. The method has incredible capabilities of recovering the DCD organs (In Kirk, 2014). The two methods are critical in reducing the metabolic and chemical reactions that can otherwise affect the normal establishment of an organ. The flow of oxygen within the organ is the principal foundation of employed by the methods of preserving organs and tissues.

Wednesday, November 20, 2019

Why people commit crimes Research Paper Example | Topics and Well Written Essays - 750 words

Why people commit crimes - Research Paper Example They decide to commit crime upon determination of potential risks such as getting caught as well as punishment, against rewards that could come with success in their acts (humans are rational with free will to choose to commit crime). Crime happens to be an immoral behavioral form which weakens the society (Steven, 2015). According to the social disorganized theory, the physical as well as the social surroundings of a person primarily determine the decisions and actions of such a person. Specifically, a neighborhood with fraying social structures more likely will have higher rates of crime. This kind of a neighborhood could have vacant as well as vandalized buildings, poor schools, a mix of commercial and residential property and high unemployment. With broken or weak bonds to religion, family, school happens to be a catalyst towards criminal behavior. Individuals fail to see the good in adherence to conventional societal values, hence commit crime believing that it is through crime that they can improve their private social conditions. Social learning explains that individuals are motivated to criminality and get criminal skills from persons they associate with. They learn from criminal friends. Lack of self-directions well as insufficient social roles happen to be the root causes for criminal behav ior (Aldunate, 2015). Biology, evolution as well as evolution – mental illness, poor diet, chemistry, bad brain or evolutionary rewards to violent criminal behavior could lead to crime. Genetics determine the behavior of an individual to a certain degree. This according the biological theory. From one generation to the other, human behavior basic determinants could be passed. This way, one can inherit criminal behavior. Psychobiological theory explains that reactions to foods, chromosomal anomalies deficiencies of vitamins or surrounding’s allergies, integrated with a specific genetic makeup could predispose

Monday, November 18, 2019

Health Organization Case Study Essay Example | Topics and Well Written Essays - 1000 words

Health Organization Case Study - Essay Example In the year 2011, UnitedHealth Group Incorporated showed total net earnings of $5.142 billion. UnitedHealth Group is the holding company of the UnitedHealthcare, and is the largest and chief health carrier all over the United States of America. The company was formed in the year 1977 and was initially called the United HealthCare Corporation. The name was changed again in the year 1998, but even the new name has its origin based in a firm that the UnitedHealth Group acquired back in the year 1977 which was called the Charter Med Incorporated and was formed in the year 1974. It was in 1979, that the UnitedHealth introduced their first network-based health plan targeting the seniors citizens in America the company became a publicly traded one in 1984. UnitedHealthcare was very recently given the highest rating in the area of employer satisfaction for all self-insured health plan companies by J.D. Power and Associates. The company also received top ratings in 2011 from the American Medi cal Association (AMA) in the National Health Insurance Report Card published by the AMA. This fourth annual report card published by the American Medical Association assessed seven different national health insurance companies on the criterion of both timeliness as well as the accuracy of their claims basing their evaluation on different metrics like the assortment of payment made to the companies, and some process metrics. UnitedHealthcare also moved to the top spot amongst all of its industry peers on the two metrics: concerning Contracted Fee Schedule Match Rate and Electronic Remittance Advice (ERA) Accuracy. Contracted Fee Schedule Match Rate basically is an indicator of how often the insurer's claim payment tallies the fee schedule put down in the initial contract. Electronic Remittance Advice (ERA) Accuracy is the measure of the rate at which the amount allowed by the insurer actually equals to the expected allowed payment of the physician’s services. In a more recent publication of the health insurance industry called the ‘Business Insurance’, UnitedHealthcare was called the "readers choice" winner for the year 2010 in the category of "Best health plan provider". In contrast to all these ratings, UnitedHealthcare was given a 65% unfavorable rating by a group of hospital executives who had on several occasions dealt with UnitedHealthcare on previous occasions. Though this number is quite good and up by about 33% from the rating in 2010, UnitedHealthcare still is at the bottom of all the companied included in the list. As already mentioned, UnitedHealthcare is a recognized leader in the health insurance claim business and it strives to constantly improve on the quality of the services they are offering to their customers and the overall effectiveness of the notion of healthcare for every American citizen. They want to enhance every individuals reach to health perks and benefits offered by the health insurance companies like theirs. Th ey are striving to constantly create new and innovative health products and services that will make the entire concept of healthcare more affordable to American citizens. They also tend to use technology to make the entire health care system easier to manage and navigate around. The different subsidiaries of the company are constantly coming up with a line up for innovative services and products for an approximate 70 million of its

Friday, November 15, 2019

Aim of the Homogenisation Process

Aim of the Homogenisation Process Introduction: Eukaryotic cells such as liver cells enclose a variety of different types of membrane bound structures called organelles (nuclei, mitochondria) as well as macromolecules (ribosomes) (Padh, 1992). Subcellular fractionation is an invaluable technique allowing scientists and researchers alike to successfully isolate and separate specific subcellular components within the cell (Becker et al, 2009). This allows researchers to study the different organelles (using biochemical techniques) in a greater degree of detail therefore increasing our knowledge about the many different types of organelles and macromolecules, thus leading to new scientific advances in this ever advancing era of science and technology (Bonney, 1982; Berns, 1986). It is this very method which in the past allowed Christian de Duve to discover the lysosomes and peroxisomes for which he shared a Nobel Prize with Albert Claude and George Palade in 1974 (Becker et al, 2009). Subcellular fractionation can be safely divided under 3 major headings: Homogenisation proceeded by fractionation and finally purification. Homogenisation: The aim of the homogenisation process is to effectively and efficiently disrupt and break the cells outer membrane thereby releasing their subcellular components (nuclei, mitochondria). This disruption and breaking of the cells must be achieved in a manner that will leave the delicate organelles of interest undamaged and morphologically intact (Loewen, 2003). The cells to be homogenised are kept in an isotonic buffer (0.25M sucrose, 1mM EDTA and 1mM of Tris at pH 7.0). This is to protect the fragile organelles from osmotic damage due to osmotic unbalance as well as environmental instability such as pH interference (Guteriezze, 2010). Many different homogenisation techniques exist and are available, some such include mechanical grinding using Potter-Elvehjen glass homogeniser, cutting methods using warren blender, ultrasonic vibrations in a process called sonication and utilising high pressure such as in the French Press (Loewen, 2003). The Potter-Elvehjen glass homogenizer was used in this experiment. The Potter-Elvehjen glass homogeniser consists of a Teflon pestle which is closely fitted into a glass homogeniser. The homogenising machine moves the Teflon pestle in a verticle up-down motion while simultaneously rotating within the glass homogeniser containing the cells to be homogenised (Mangiapane, 2010). The space between the Teflon pestle and glass homogeniser is incredibly small (0.004-0.006). Therefore as the Teflon pestle moves throught the glass homogeniser a shear force is generated which causes disruption of the cells. The organelles which are released by this process pass undamaged, safetly through the gap between the pestle and glass homogeniser (Loewn, 2003; Mangipane, 2010). The shear forces produced can sometime be destructive to the organelles causing irreversible damage and therefore shear forces need to be controlled. This can be controlled by adjusting the gap width between the pestle and glass homogeniser. A bigger width can protect organelles from damage but the negative side effect of this is that the generated shear forces will not be strong enough to disrupt the cells and therefore few or none organelles will be present in the homogenate. Therefore a careful balance between cell disruption and organelle damage must be maintained. Chemical, physical and structural damage can be caused to organelles due to shear forces which can cause errors when purifying the organelle using biochemical techniques due to enzymes specific to the particular organelle being damage or rendered inactive and these problems must therefore be overcome. Some such precautions which when utilised can overcome or minimise unnecessary damage includes the use of different homogenisation techniques which are more suitable for the cells being homogenised (osmotic disruption, chemical disruption may be considered). Carefull usage of the homogenising equipment (Lowen, 2003). Fractionation: Once the homogenate has been formed, it is ready to be placed in a centrifuge and undergo centrifugation which will separate the different fractions/organelles. Centrifugation generates a centrifugal force which separates the different types of organelles based on their size and density as well as the density and viscousity of the solution the homogenate is in. Therefore the the higher the molecular weight of the organelle the greater the distance I will travel down the centrifuge tubes or the higher its sedimentation rate and consequently the smaller the molecular weight of the organelle the smaller the distance it will travel down the centrifuge tube or the lower its sedimentation rate (Becker et al,2008; Mangipane, 2010). The greater an organelles sedimentation rate is the greater the organelles sedimentation coefficient (in Svedberg units, named after Theodor Sveber who developed the ultracentrifuge) will also increase (Becker et al, 2009). Centrifugal forces can be calculated using For example, if a homogenate containing nuclei, mitochondria and ribosomes is subjected to a centrifugal force, logically the nuclei will be near the bottom of the tube, the ribosomes at the top part of the tube and the mitochondria somewhere in between the nuclei and ribosomes. There are 2 main type of centrifugation methods: Differential centrifugation and density gradient centrifugation. Differential centrifugation This type of centrifugation works on the principles that large dense molecules (nucei) will have a higher sedimentation rate compared to small and less dense molecules (ribosomes) (Becker et al, 2009). During low centrifuge speeds and short times the heavy and dense organelles sediment and can be collected, while as high centrifuge speeds and longer timer the lighter and less dense molecules will sediment and can also be collected (manipulative techniques). Therefore in the homogenate used in the experiment, by using appropriate centrifuge speeds and times the nuclei and mitochondria can be separated using 1500g for 10min and 20000g for 10min respectively. Density gradient centrifugation The method used in density gradient centrifugation, also known as rate-zonal centrifugation works on the principle of separating molecules based on their densities and is achieved by using a density gradient in the centrifuge tube (manipulative techniques; Becker et al, 2009). The density gradient is normally provided by a concentrated sucrose solution which increases in density towards the bottom of the centrifuge tube. The sample requiring fractionation is placed in a layer over the density gradient sucrose solution (Becker et al, 2009). As the centrigugation process proceeds, the different molecules or organelled of different densities are separated based on their densities and that of the increasing sucrose density. When the fractionation bands have been formed are are distinctive the fraction may be remover via a syringe or separation methods. This type of centrifugation can be used to further separate mitochondria from lysosomes and peroxisomes since each of them has a differen t density. Measurements of enzyme activity and macromolecular composition of fractions. purity of fractions. During the centrifugation processes, such as in the differential centrifugation the various types of organelles and macromolecules form gelatinous pellets at the end of each consecutive centrifuge (Dyson, 1979). The different pellets produced contain a variety of different fractions of subcellular organelles and macromolecules and is not specific for just a single type of organelle or macromolecule. As an example in the first centrifugation process to form the nuclei fraction at 1500g for 10mins, the nuclei is pelleted along with other molecules of similar size and molecular weight such as unbroken cells, cell debris and pieces of the cell membranes (Bonney, 1982). In the second centrifugation to form the mitochondrial fraction at 20000g for 10min the pellet contains mitochondria, lysosomes and peroxisomes due to their similar sizes and molecular weight. In the final centrifugation process at 20000g for 10min a supernatant fraction was formed containing many small and low molecular w eight molecules such as the endoplasmic reticulum, microsomes and ribosomes (Minorsky, 2009; Berns, 1986). As stated before fractions will not only require the organelles of interest but also other organelles and macromolecules. It is therefore necessary to be able to assess the purity of the fractions. This can be done in a variety of ways. Microscopic analysis via the light microscope or even electron microscope can be used to identify the different macromolecules present within the fraction, therefore giving an indication whether or not the fractionation procedure has been successful. A mitochondrian therefore can be differentiated from a peroxisome or lysosome basen on its structure (Bonney, 1982). Microscopic anaylsis can also be used in assessing the biochemistry of the fraction by using various cytochemical techniques. Biochemical techniques are a very good way of assessing the type of organelle present as well as the purity of a fraction. Measuring enzyme activity is an excellet method sine some enzymes are very specific and found in one particular organelle. Marker enzymes present in fractions and importance of the techniques involoved in the advancement of biochemistry and cell biology. Marker enzyems are routinely used in subcellular fractionation to differentiate between the many different types of organelles and macromolecules present within the cell. Mitochondria for example can be detected indirectly by the presence of succinate dehydrogenase while lysosomes can be detected by Acid Phosphatase (Bonner, 2007). The function of the mitochondria for example is to generate adenosine triphosphate (ATP) by a process called oxidative phosphorylation and an enzyme specific to the mitochondrion called succinate dehydrogenase can be used as a marker enzyme to differentiate between the presence of mitochondria and other organelles and macromolecules present in the fraction (Padh, 1992). Succinate dehydrogenase (SDH) is specific to the inner mitochondria membrane and is responsible for catalysing the oxidation reaction of Succinate, which is a component of the citric acid cycle, into fumarate which is another component of the citric acid cycle. Since flavin adenine dinucleotide (FAD) is reduced producing FADH2 (Guterize, 2010; Padh, 1992;Girolamo, 2010). Succinate is the electron doner while FAD is the electron acceptor. The products of the above reaction are then reacted with an artificial electron acceptor called INT(a tetrazolium salt) to form a red coloured compound called formazan. This reaction is required because both the fumarate and FADH2 produced in reaction are colourless and therefore there is no certain way of determining succinate dehydrogenase activity, therefore the intensity of the red coloured formazan produced during a specific timeframe in the second reaction can be measured using a spectrophotometer gives an indirect indication of succinate dehydrogenase activity and therefore an indication of the presence of mitochondria as well as its purity within the fraction (guterize, 2010; padh, 1992). Electron microscopy of the isolated organelles is generally the final step in assessing the purity of the fractions as well as studying their morphology (padh, 1992). It is these methods and techniques used in subcellular fractionation which has allowed researchers such as George Palade and Christian de Duve studying to understand and discover the structures, biochemistry and roles played by the various organelles. Results: Table 1 shows the volumes of the homogenate, nuclei fraction, mitochondrial fraction and supernatant fraction. The Homogenate volume was obtained after rat liver homogenisation; NF volume was obtained after 2 consecutive centrifugations at 1500g for 10min; MF volume was also obtained by 2 consecutive centrifugations at 20000g for 10min; SF volume was obtained from the supernatant of the MF centrifugation. Table 2 shows known amounts of bovine serum albumin (BSA) which underwent the biuret reaction; the absorbances were measure using a spectrophotometer at 550nm. As protein amount increases so do the absorbances. This data was used to plot a BSA standard curve. Figure 1 illustrates the BSA standard curve which is a line of best fit. From this graph, the protein amount is determined by using the absorbance values for the different fraction shown in table 3 below. H, NF, MF and SF correspond to homogenate, nuclei fraction, mitochondrial fraction and supernatant fraction respectively. The vertical and horizontal red, blue, green and black coloured lines represent H, NF, MF and SF respectively. From the above graphical data Protein concentration (mg/ml), total protein amount (mg) and protein recovery for each fraction relative to the homogenate can be calculated. Homogenate: Nuclei Fraction: Mitochondrial Fraction: Supernatant Fraction: From the above results the total percentage of protein recovery relative to the homogenate can be determined: The above calculated results are show together in table 3. Table 3 shows the absorbance values obtained from the spectrophotometer. Row B shows the amount of protein that was determined from the BSA standard curve. Row C showed the amount of protein present in 1ml of each fraction; the homogenate had the highest protein concentration, followed by the SF and MF and finally by the NF containing the lowest amount of protein concentration. Row D shows the total amount of protein in each of the fraction and therefore follows the same pattern as the values for Row C. Row E shows the amount of protein recovered relative to the homogenate; The percentage of protein recovery was as follows: SF>MF>NF. Table 4 shows the actual fraction concentrations used, obtained by diluting the original fractions (table 3) with phosphate buffer. The supernatant fraction was left undiluted. Table 5 shows absorbance of each of the fractions (0.2ml) which were diluted by the addition of 4ml of ethyl acetate within formazan. The average absorbance minus the control gives the corrected mean absorbance for each of the fractions. The control values for all 4 fractions were 0 because they were given as negative values by the spectrophotometer. The highest absorbance was recorded for the SF followed by the homogenate, MF and NF. By obtaining the data collected from the previously calculations in tables 1, 3 and 5 it is possible to calculate; the total activity of Succinate Dehydrogenase (SDH), the percentage recovery of SDH relative to the homogenate, the specific activity of SDH and the relative specific activity of SDH relative to the homogenate in all 4 fractions (H, NF, MF and SF). Below are the equations which will be used in the calculations: Beer-Lamberts Law: The calculations below will make (concentration) the subject of the formula as well as prove that the units for = or . à ¢Ã‹â€ Ã‚ ´ this can be rearranged to form, , since always equals to , the equation can now be represented as, , the units of this new formula can be calculated as follows, the in the bottom fraction can be cancelled out with the at the top giving, Which à ¢Ã‹â€ Ã‚ ´ gives which is Molarity or concentration. The equation will be used throughout the rest of the calculations. The Formazan molar extinction coefficient= and the assay volume used will be 0.004L (4ml). Homogenate: The absorbance for the homogenate in table 5 was 1.1385 therefore, à ¢Ã‹â€ Ã‚ ´ since this can be arranged to give, The volume used was which gives therefore, Activity à ¢Ã‹â€ Ã‚ ´ à ¢Ã‹â€ Ã‚ ´ total activity of in -1 The answer is required in à ¢Ã‹â€ Ã‚ ´ since Therefore total activity for Homogenate = à ¢Ã‹â€ Ã‚ ´ Therefore specific activity for Homogenate Nuclei Fraction (NF): The absorbance for the nuclei fraction in table 5 was 0.117 therefore, à ¢Ã‹â€ Ã‚ ´ since this can be arranged to give, This gives, Activity à ¢Ã‹â€ Ã‚ ´ à ¢Ã‹â€ Ã‚ ´ total activity of in The answer is required in à ¢Ã‹â€ Ã‚ ´ since Therefore total activity for Nuclei Fraction = à ¢Ã‹â€ Ã‚ ´ Therefore specific activity for Nuclei Fraction Mitochondrial Fraction (MF): The absorbance for the mitochondrial fraction in table 5 was 0.398 therefore, à ¢Ã‹â€ Ã‚ ´ since this can be arranged to give, This gives, Activity à ¢Ã‹â€ Ã‚ ´ à ¢Ã‹â€ Ã‚ ´ total activity in in The answer is required in à ¢Ã‹â€ Ã‚ ´ since Therefore total activity for Mitochondrial Fraction = à ¢Ã‹â€ Ã‚ ´ Therefore specific activity for Mitochondrial Fraction Supernatant Fraction (SF): The absorbance for the supernatant fraction in table 5 was 1.485 therefore, à ¢Ã‹â€ Ã‚ ´ since this can be arranged to give, This gives, Activity à ¢Ã‹â€ Ã‚ ´ à ¢Ã‹â€ Ã‚ ´ total activity in in The answer is required in à ¢Ã‹â€ Ã‚ ´ since Therefore total activity for Supernatant Fraction = à ¢Ã‹â€ Ã‚ ´ Therefore specific activity Supernatant Fraction Calculations for the % SDH recovery and specific SDH activity relative to the homogenate; Since the % SDH recovery and specific SDH activity is to be calculated relative to the homogenate, therefore the homogenate percentage for them both will be 100% Nuclei Fraction: Mitochondrial Fraction: Supernatant Fraction: The main findings of these calculations can be summarized in the table below: Table 6 shows that SDH activity is highest in the SF, followed by the homogenate, MF and finally by NF. The %of SDH recovery (relative to the homogenate) was greatest in the SF, followed by the MF and the NF. The specific SDH activity was greatest in the SF followed by the MF, NF and lastly by the homogenate. The % of specific SDH activity (relative to the homogenate) was greatest in the SF, followed by the MF and NF. Figure 2 illustrates the main findings from table 6. It can be seen that % SDH recovery increases from the Nuclei fraction to the supernatant fraction. The % of specific SDH activity steadily falls from the supernatant fraction to the nuclei fraction. Discussion: According to the results obtained in table 3, it was seen that 99.25% of the protein relative to the homogenate was still present within all the fractions. This high percentage recovery indicates that very little protein was lost during the formations of the nuclei, mitochondrial and supernatant fractions by centrifugation. The 0.75% of protein that was lost is most likely to have been lost while homogenizing the pellets formed during each consecutive centrifugation process. During the usage of hand homogenizers small quantities of the pellet containing the proteins are stuck to the homogenizing vessel or the pestle. These small quantities of proteins being lost during each hand homogenizing process therefore contributes to the loss of proteins recovery. From this high protein recovery it can be said that the overall homogenisation process was very efficient. During each successive centrifugation at different speeds a distinct pellet was formed, thus indicating the separation of organelles. In table 3, different amounts of proteins were present within the pellets. Since these proteins are associated with the different organelles present, this indicates that since different amounts of proteins were found in the fractions therefore various different types of organelles must also be present. But this is not always the case since proteins from other fractions could have been damaged due to the homogenization and centrifugation processes. Therefore the calculations performed on Succinate Dehydrogenase activity, recovery and specificity (table 6, figure 2) showed that that the total SDH activity was highest in the supernatant fraction. Since SDH is a specific marker enzyme to the mitochondrion organelle as explained earlier, the data suggests that the separation of mitochondria during centrifugation to be present within the suspected mitochondr ial dfraction was not optimal. The supernatant also had a very high protein content of 885mg (table3) which indicated therefore that most of the organelles have separated into this freaction, thus indicating the hight amount of SDH activity within the supernatant fraction. In a differential centrifugation process the successive increases in the centrifugal forces applied should create a gradient of the presence of different organelles, with the heaviest molecules in the centrifuge tubes with lowed centrifugal forces, the mediam molecular weighted organelles such as mitochondria in a centriguge in the centrifuge with a medium centrifugal force is applied and small molecular weight organelles such as ribosomes in the centrigue tubes where the highest centrifugal forces are applies. Therefore the separation of organelles has occurred but not to a great extent as seen by the reults in table 3 and table 6. Seperation of organelles could have been greatly improved by possibly refining the lab protocol. To ahieve better mitochondrial separation and therefore more accurate SDH activity measurments the centrifugation process should be done at 20000g but for 20min and not 10min as stated by Loewen (2003) and Becker et al (2009). This will help separate the mitochondria out better. Different centrifugation methods such as density gradient centrifugation can be utilized after the intital differential centrifugation to better separate organelles of similar sizes such as mitochondria, lysosomes and peroxisomes. The new fractions produced can by the densiy gradient centrifugation can be recovered with the use of a syringe. Many other techniques such as the initail homogenisation stage could also have been changed and other techniques could have been used as described earlier. Conclusion: It was found by this experiment that subcellular fractionation is not a perfect method and therefore inaccuracies must be expected. But it is a process that has revolutionaised our understanding of cell structure and function. It was found in the experiment that differential centrifugation can separate organelles to an extent to form a nucleic fraction, mitochondrial fraction and supernatant fraction. Marker enzymes which are present in specific organelles can be used to help distinguish between different organelles as well as the fractions relative purity. SDH was used in this experiment and was found to be present higher in the supernatant, possibly due to experimental error. SDH was specific to the supernatant fraction therore again indicating the presence of mitochondria in the supernatant. The usage of such techniques in this ever advancing era of science and technology has set the stage for future studies and techniques involved in further studying the cells and increasing our knowledge of life as each day passes.

Wednesday, November 13, 2019

Monster Hunters :: Essays Papers

Monster Hunters Monsters are hunted. The lore of their destruction is excessive, glowing, and dispersed. It is a crucial component of their mythology. There is no eluding the hunter, armed with the vampire stake and crosses and the werewolf’s silver bullet. But then it is the hunter whose tale it is to begin with. Beowulf cannot stay hidden forever, or he would not be Beowulf. Monstrosity relies, in this sense, on its exposition for its production, and it is in this superficial sense of vitality by revelation that two theorists of monstrosity concoct a fantastic world of ‘society’ to keep themselves at bay. Michael Uebel’s â€Å"Unthinking the Monster† and Mark Dorrian’s â€Å"On the Monstrous and Grotesque† represent similar though distinct theorizations of monstrosity in terms of otherness, difference, relation to self, and production in/by rhetoric. The articles consider the relation between monstrosity and the terms against which it is defi ned. Yet the pieces are also monsters, and the worlds they sing of are the ones they behold with rapt attention. It is their theorization of monstrosity that allows for the continuation of both insides and outsides in a way more immediate than their encapsulation of such a movement considers. Dorrian takes Uebel’s general form of abjection seriously as a description of aberrations of the body, the human body it even seems. â€Å"As a starting point we will assume the conventional understanding of the monster as a being whose existence runs against, or is contrary to, nature - with the proviso that for ‘nature’ we understand as ‘what has been naturalized’† (Dorrian 310). The article’s understanding of monsters departs little from the starting point, for the terms outlined here. What of the understanding itself? It seems accurate to require that monsters enact renditions of living bodies. However, this assumes monstrosity not only contrasts some pre-selected canon of bodies, but also is to correspond to a set body of monsters, which is of course never set, and thus monstrosity is to predict what might be called monstrous. But the term is not only part of an effort to describe some referent. Monstrosity is also to think t hrough or around the functioning of monster as agency - how does the idea of a monster matter. Or, how does the monstrous feeling fragment representations? In any case, it is to be a study of monstrosity, for both Dorrian and Uebel, that is aware of the impossibility of identifying a definition or set of definitions of monstrosity.