Support teaching and learning activities Essay Example

Bolster instructing and learning exercises Essay Example Bolster educating and learning exercises Essay Bolster instructing and learning exercises Essay The instructor will get ready for the long and medium term arranging, they may set time aside during the week to examine the learning destinations for the exercises with the goal that the help professional will have an away from of what Is normal of the exercise and how to enable the youngsters to accomplish this. Working with Special Needs Children inside the study hall setting they will have distinctive learning goals and will need additional help. During the arranging a help specialist ought to have the chances to give any information and proposals into the exercise plan/learning objective with regards to any troubles which may thwart the learning procedure. During a movement bolster professionals ought to be watching and checking to give the instructor effective input. Youngsters ought to likewise be commended and given a lot of consolation to help develop confidence and certainty. Toward the finish of the exercise the help expert and the educator ought to talk about whether the learning goals for the exercise was effectively accomplished and examine any issues that emerged. 03 Support Learning Castles Evaluate own qualities and shortcomings corresponding to help learning 1. 2 and how these may affect on the help that can be given. Exercises be straightforward with yourself as well as other people, ensure you assess accomplishments just as disappointments, incorporate all parts of your work, and afterward consistently approac h a partner for help and guidance if necessary. Thinking about your work will assist with improving your own aptitudes and furthermore extend information. Qualities Easily agreeable Being versatile Team work Willing to take a stab at anything new Working alone Patience Relational abilities (great) Using assets to profit getting the hang of Knowing your jobs and obligations Asking for assist Display with working Weaknesses Sometimes can require a significant stretch of time to process data (reiteration required) in subjects not solid in Dont consistently comprehend exercise plans Use of workstations, note pads and PCs on programs Im inexperienced with Communication with right wording (here and there get stirred up).

ECO203 Final Essay Example | Topics and Well Written Essays - 1250 words

ECO203 Final - Essay Example These would influence the other financial factors which incorporate Aggregate interest, Gross Domestic Product and Employment of a nation. The Government would go for an Expansionary Fiscal arrangement in the midst of downturn in which U.S. Government would spend more than they would gather charges from the individuals. That is government spending would surpass charges. The inverse would occur if there should arise an occurrence of a Contractionary Fiscal Policy where the legislature would build the assessments more than it means to spend. Presently government spending may represent an assortment of exercises which incorporate streets, training, human services, government assistance exercises and protection. This administration spending is financed primarily by tax assessment (Blanchard, 2010). There are other elective methods of financing like printing cash, outer borrowings from outside nations and so on. The administration may likewise get from the open which is called open obliga tion. However, this would be finished by the legislature just when on the event of a shortfall in the administration spending plan. The U.S. Government uses the Fiscal approach in the undertaking to influence the total interest alongside full business. When there is insufficient total interest in the economy, the legislature would diminish the pace of tax assessment and increment the uses by utilizing inactive assets. This would prompt increment in the development pace of the economy and would tend towards full work by diminishing the pace of joblessness. Accordingly the yield would increment. This sort of government spending has a multiplier impact since when an administration begins another task, alongside the yield of the venture it creates work for the laborers and henceforth the utilization and investment funds. Anyway Fiscal Policy may likewise be compelled by a swarming out impact which would occur if there is an ascent in loan costs which would check speculation. In any case , in the event that the economy is experiencing a downturn, at that point effectively a great deal of assets are unused and subsequently this would not represent an issue for the economy unequivocally (Froyen, 2005). Fiscal Policy The financial arrangement is actualized by the Central Bank with a control on target gracefully with is attempted with the assistance of a few strategies. This can be controlled primarily by buy or sell of securities which increments or diminishes the flexibly of the cash in the economy. Presently bonds are obligation instruments that ensure the purchaser the arrival of the head alongside an intrigue or the coupon at some predefined date. This pace of premium or the coupon rate is controlled by the Central Bank and one of the instruments by which the Central Bank controls the flexibly of cash in the economy (Mankiw, 2012). Presently, when the bank needs to lessen the cash flexibly of the economy or diminishing the liquidity, it would go for a Contractionar y Monetary approach wherein it would begin expanding the loan fees. Subsequently, the coupon paces of the securities would expand which would constrain individuals to stop their cash with the banks, having less cash in their grasp. This would prompt a decrease in liquidity in the whole monetary framework. In opposition to this by an Expansionary Monetary strategy, the Federal Reserve Bank would diminish th

Student Group Spotlight UN Studies Working Group COLUMBIA UNIVERSITY - SIPA Admissions Blog

Student Group Spotlight UN Studies Working Group COLUMBIA UNIVERSITY - SIPA Admissions Blog Life at SIPA is more than just a rigorous and exciting curriculum. The SIPA community is greatly enriched by the numerous student organizations on campus. We thought it would be useful to spotlight some of these organizations to give you a more holistic view of the SIPA experience. The UN Studies Program Working Group (UNSWG) is a student organization that works in close relation with the UN Studies Program at SIPA. It aims to connect students and the entire SIPA community to the United Nations, to its issues and agenda, and to the UN System as a whole. UNSWG members are dedicated to the UN’s main goals, including principles of worldwide cooperation for peace and prosperity. ?The UNSWG serves as a platform for delivery and exchange of knowledge, ideas, thoughts and reflection, debates and discussion on issues related to the United Nations and the UN system. ?The UNSWG works to foster a close relation between SIPA and the UN: to prepare conferences, seminars, discussion panels and groups; invite speakers and prepare presentations; organize student debates around relevant and current issues related to the UN. ?The UNSWG aims to maximize opportunities for SIPA students to be involved with the UN and the greater UN family through meetings with officials; visits to the UN Secretariat and UN agency headquarters; inviting speakers to SIPA; organizing internships, career panels, and support for individual initiatives related to the UN. Within the first month of the semester, the UNSWG has coordinated the following events: “How to get a job at the UN” panel with a representative from the UN’s Human Resources department UN Studies Retreat, “70 Years Later: The United Nations at a Crossroad in a Changing World”, which featured speakers from the UN Secretary-General, the UN Development Programme (UNDP), the International Peace Institute, the UN Secretary-General in Africa, and the United Nations Foundation Participation in an upcoming talk given by former UN Secretary-General Kofi Annan on challenges for the UN in the 21st Century Check out the UNSWG’s blog for a list of past events and its general page for more information.

Diagnosis And Diagnosis Of Cancer - 1485 Words

â€Å"The aim of screening a population for cancer is to make the diagnosis early and thereby increase the cure rate.† (Tobias and Hochhauser,. Cancer and its Management, 2010 p21) Cancer is a worldwide problem that attributed to 12% of total worldwide deaths in 2000 (Symonds et al. 2012). From such a statistic, one can conclude that the issue of cancer is one that needs addressing and that diagnosis and treatment services must be readily available if the mortality rate from cancer is to fall. In the United Kingdom it has been stated (Tobias and Hochhauser, 2010) that more than one in three people will develop this disease at some point throughout their lives again highlighting the need for adequate services. There are several screening techniques which can aid in the early detection and diagnosis of, cancers. The screening of cancer often works hand in hand with epidemiological research in order to establish the most high risk members of the population. Screening is actively carried out in diagnosis of breast, prostate, cervical and colorectal cancer. Breast cancer is the world’s second most common cancer (Symonds et al., 2012). Breast cancer is screened for through mammography which involves producing a radiograph of the breasts to allow tissue study. According to a recent survey carried out in the United Kingdom (National Health Service Breast Screening Programme. 2011), 73% of women invited for a breast screening mammography test accepted the invitation and were screenedShow MoreRelatedCancer Diagnosis And Treatment Of Cancer Essay1480 Words   |  6 PagesCancer is characterized by abnormal, uncontrolled cell growth, and it disrupts normal body function, as it increases energ y demands and alters body systems. There are many factors that can lead to the development of cancers, including genetic, behavioral, and environmental influences. The presence of disease is not always obvious; therefore, it is imperative for individuals to participate in screening interventions to promote early detection. Cancer diagnosis and treatment requires a patient-centeredRead MoreSymptoms And Diagnosis Of Cancer3436 Words   |  14 PagesTERMINOLOGY CLINICAL CLARIFICATION †¢ Cancer that develops in the cells of the breast 12 †¢ Diagnosis requires a tissue biopsy for microscopic examination to determine pathology CLASSIFICATION †¢ The TNM classification is used for clinical staging of breast tumors. The American Joint Committee on Cancer (AJCQ 7th edition stages breast cancer as follows: 12 o TX: primary tumor cannot be assessed o TO: no evidence of primary tumor o Tis: cancer in situ - Tis (DCIS): ductal carcinoma in situ - Tis (LCIS):Read MoreDiagnosis And Treatment Of Cancer Essay1844 Words   |  8 Pages Cancer is very large throughout the U.S. and Canada, it is said that one and a half million people will receive a new diagnosis of cancer each year (Ignatavicius Workman, 2013).Many years back a diagnosis of cancer had a very poor outcome and you were basically considered dead. Technology and research have been focusing on cancer, and how to prevent it. This paper will review the diagnosis of cancer as well as the staging of cancer, as well as possible treatment options and side effects relatedRead MoreThe Treatment Of A Cancer Diagnosis951 Words   |  4 PagesA Cancer diagnosis may bring on many negative emotions, questions and uncertainties in a patient. Even though we now have different types of treatments for cancer, there are still numerous deaths annually attributed to the diagnosis. The World Health Organization has described the number of mortalities to be greater than 8.2 million annually around the world (World Health Organization [WHO], 2015). As nurses, we must se rve as the patient’s advocate and empower them throughout the course of theirRead MoreDiagnosis And Treatment Of Cancer1954 Words   |  8 PagesIntroduction When it comes to the topic of cancer, most people readily agree that we have made leaps and bounds in diagnosis and treatment mechanisms. Where this disagreement usually begins, is on the question if finding a â€Å"cure† for cancer can be a reality. While some are convinced that a cure will come with time, others believe that a single cure is just not logical. The US waged a war on cancer when Nixon was in office, 1971, yet we haven’t overcome it yet (Gorski). After research, I believeRead MoreEssay On Automatic Diagnosis For Cancer1155 Words   |  5 PagesAutomatic diagnosis for cancer is a ongoing topic of research. Previous research have been conducted on breast cancer diagnosis. Doyle et al. [9] investigated the classification of breast cancer histopathology from textual, nuclear architectural features and images. Classification of benign and malignant histopathological im- ages based on 10 syntactic structure features, extracted after the Gabor filter had been applied was used by van Diest et al.[10]. The usage of Support Vector Ma- chines (SVMs)Read MoreThe Diagnosis And Treatment Of Breast Cancer1947 Words   |  8 Pages3D Mammography The diagnosis and treatment of breast cancer and other non-cancerous diseases are very important in improving the quality of life for many women. The early diagnosis of the non-cancerous disease can reduce the incidence of breast cancer through effective treatment of mastopathy (fibrocystic of the breasts tissue). In the area of study, a variety of imaging modalities is implemented to assist with the diagnosis. These imaging modalities includes multi-frequency electrical impedanceRead MoreEffects Of The Diagnosis Of Bowel Cancer915 Words   |  4 PagesGoldwasser (2009) accepted that being diagnosed with cancer comes as a terrible shock for most people and those affected may look back on the experience and remember it as all being a bit of a dream. Often they are given information that they are only able to take in part of what they are told. As the news sinks in and they are ready to talk about what is going to happen, the most important thing to remember is that it is their body they are discussing. People must be allowed to make decisionsRead MoreDiagnosis And Treatment Of Prostate Cancer1681 Words   |  7 Pageshard-to-cure disease like cancer. Prostate Cancer is a known cancer that happens to men only and a lot of men in the U.S are diagnosed with it, and happens to male’s reproductive system. Specifically speaking, it is a gland found in the most private area of a man. In the following paragraphs, I will be explaining why we need to find a way to combat prostate cancer, how to detect this cancer at early stages, and the risks associated with prostate cancer. Prostate cancer is the second leading causeRead MoreCancer : Etiology, Symptoms, Diagnosis, And Treatment1718 Words   |  7 Pages Colon Cancer: Etiology, Symptoms, Diagnosis, and Treatment Harold Scott Delaware Technical Community College Biology Professor Riggio November 18, 2014 Abstract A well-known fact is that cancer plays a major role in the area of health science in the United States. Cancer touches many individuals and many families across the nation. With a variety of types of cancer as well as causes, symptoms, and treatments cancer is a very broad topic of research. In particular my research focuses on

Thoreau and Transcendentalism Essays - 778 Words

Followers of the Transcendentalist movement stressed the religious, philosophical and ideological importance of life. Henry David Thoreau was a staunch supporter of the movement. Thoreau felt that a person lived a good life by following his conscience and instincts. He also felt that materialism was a sure way to distract a person from leading a good and moral life. Thoreau proposed for the government to be involved in as little of a citizens life as possible; he felt too much government control just complicated a persons life. Like most Transcendentalists, Thoreau believed there was a direct connection to God through nature. If a person appreciated nature he would gain a higher understanding of God. Finally, Thoreau encouraged†¦show more content†¦Instead, Thoreau built a simple but efficient cabin and furnished it with the basic necessity of a bed, table, chairs and desk. He also didnt waste his time and energy trying to keep up with the latest fashions; he wore co mfortable and long lasting clothes. Thoreau explained to his readers that this simplistic way of life decreased the dreariness of every day life and left more time to explore ones meaning of life and his role in the world. Freeing oneself from the economic race, Thoreau argued, allowed for individual to be inspired by nature and focus on the genuine concerns of life. In Thoreaus Civil Disobedience, he argues that when civil laws conflict with an individuals morality, the individual should follows his conscience. Thoreau like many Transcendentalists felt a less involved government was best. Thoreau wrote, That government is best which governs not at all. Obviously, Thoreau realized that he could afford to take this open opinion on government because of the American government. But he felt that governments authority should be limited to physical matters of the country, such as infrastructure and orderliness. He felt a government that become involved in moral matters such as sobriety and slavery was a government over-stepping its boundaries. Ultimately, Thoreau and other transcendentalists felt a utopian society would be the best.Show MoreRelatedThoreau And Transcendentalism1518 Words   |  7 Pagesmust be slaves† is a political statement that never lost its topicality during the Romantic era. Thoreau served as an important contributo r to the philosophical and American literary movement known as New England Transcendentalism. Nature and the conduct of life are two central themes that are often weaved together in his essays and books that were published in the Romantic era of literature. Thoreau brought these two themes together to write on how people ought to live a simplistic life throughRead MoreThoreau And Transcendentalism Analysis828 Words   |  4 PagesThoreau’s views on Transcendentalism and how he practiced it. If it has not become apparent thus far Emerson and Thoreau were close friends and lived with each other on occasion. Naturally because of their close friendship they influence each other’s work, but in most cases you can see Emerson’s influence in Thoreau’s works clearly. His is the main difference between the two writers however in their belief and writing patterns Thoreau loved nature. Thoreau’s love of nature can e explained here inRead MoreThe Ideas Of Tran scendentalism By Emerson And Thoreau1264 Words   |  6 PagesTranscendentalism, in response to enlightenment, was the redefinition and introduction of the ideas of self-dependence and spiritual guidance. Alongside these points, the complexity of our relationship with nature was explicitly explained, and the importance of stable morals was expounded. Transcendentalists, mainly led by Emerson and Thoreau, who were the literary leaders of that time, introduced a new way of thinking that implored the world around them to get in touch with their core and theirRead MoreEmerson And Thoreau : The Ideas Of Transcendentalism960 Words   |  4 PagesTranscendentalism started long before people can most likely remember. Transcendentalism is â€Å"a philosophy which says that thought and spiritual things are more real than ordinary human experience and material things,† (Webster). In this it explains that life is more than just physical needs. Life is about a whole other mental or conc eptual area. Not what you can touch or feel or even think, but what is behind all of the ideas. In the world, there are two boxes, there is the idea box, then there isRead MoreHenry David Thoreau And Transcendentalism1346 Words   |  6 PagesHenry David Thoreau was born and lived his life in Concord, Massachusetts. Thoreau had always been an intelligent student and eventually began his study at Harvard University and graduated at the top of his class despite having to drop out on several occasions due to his financial struggles. Around the time when Thoreau was graduating,   America had been experiencing an economic depression resulting in the loss of jobs of many and work became harder to find. But because Henry Thoreau was a HarvardRead MoreThe Effect Of Transcendentalism : Henry David Thoreau1654 Words   |  7 PagesThe Effect of Transcendentalism: Henry David Thoreau Transcendentalism is the American literary, political, and philosophical movement of the early nineteenth century that was rooted in the pure Romanticism of the English and the German (Goodman). Ralph Waldo Emerson is considered the father of Transcendentalism because his literature is the first to praise the notable spirituality of nature. The basic belief of the movement is to live authentically; being true to oneself (Day). The movement itselfRead MoreTranscendentalism: Henry David Thoreau Essay1096 Words   |  5 PagesHenry David Thoreau was born on July 12, 1817 in Concord, Massachusetts. Thoreau grew up in poverty; his dad was unsuccessful and had trouble maintaining a steady job. Thoreau followed in his father’s footsteps, ultimately bouncing from job to job, scorned by society for his unconventional way of living and lack of income (Henry David Thoreau, Discovering Biography). Thoreau began to write with the guidance of Ralph Waldo Emerson who became one of the mos t important influences in his life. LivingRead MoreHenry David Thoreau : The Philosophy Of Transcendentalism1055 Words   |  5 PagesThe philosophy of Transcendentalism, according to the article â€Å"Transcendentalism, An American Philosophy† is believed to have been created and led by Ralph Waldo Emerson, which is why he is considered by many literary scholars and historians to be the father of Transcendentalism. Throughout the years, this philosophy attracted other artists and thinkers such as the American Romantic novelist Henry David Thoreau. These prominent and poetic individuals created an insight for this movement, believingRead MoreHenry David Thoreau And Chris Mccandless Transcendentalism1618 Words   |  7 Pagesadvised by people to start engaging in the concept of solitude. Henry David Thoreau and Chris McCandless were both transcendentalism that believes in the key fundamental idea that the human body should partake in such as solitude. Henry Thoreau was a tra nscendentalist that practiced the form of solitude throughout his life. He left society and moved into the woods to be removed from the confines of society. Along with Thoreau, a more modern-day transcendentalist was known as Chris McCandless. McCandlessRead MoreTranscendentalism : Henry David Thoreau And Ralph Waldo Emerson847 Words   |  4 PagesTranscendentalism relates to freedom in several ways. Freedom is the power or right to act, speak, or think as one wants without hindrance or restraint. Ralph Waldo Emerson and Henry David Thoreau are two transcendentalists that have different views on freedom. Our project, representing freedom, shows a person how to live his or her life in a way of freedom shown by Emerson and Thoreau. Together, we did research on the transcendentalists: Henry David Thoreau and Ralph Waldo Emerson. We studied

Inft Adult Learning Theory Free Essays

inft Adult Learning Theory Dustin Stamey Adult Learning Theory Summary Non Traditional college students make up a large percent of the total population. There are a few categories that they fall into. The first category is workers. We will write a custom essay sample on Inft Adult Learning Theory or any similar topic only for you Order Now Non-traditional students might have either lost their job or are doing training to move up the ladder from their current position. The second category is military veterans. After years in the service, their professional education took a back seat. All they know is military service. For them, it will be really hard to acclimate into civilian life. The third category is adults that just received their GED and are now pursuing a life in higher education. It is important to provide for the adult learners so that they can thrive. M. S. Knowles said that there are four principles that characterize adult learners. â€Å"1. They are self directed, take responsibility for their own actions, and resist having information arbitrarily imposed on them. 2. They have an extensive depth of experience, which serves as a critical component in the foundation of their self identity. 3. They are ready to learn. As most adult learners return to college voluntarily, they are likely to actively engage in the learning process. 4. They are task motivated. Adult students returning to college attend for a specific goal and the primary component of their motivational drive tends to be internal† (Knowles, 1984) According to Schraw and Moshman there are three â€Å"Metacognitive Frameworks† that help people build their own learning theories. These would include Tacit, Informal, and Formal. Some of the metacognitive skills are built over time, such is the case with tacit and informal theory. These are made from educators and very repetitive jobs that do not require critical thinking. One of the biggest problems with adult learners is their gap in education. The adult has learned practical education instead of learning academic knowledge. Practical knowledge can be used in everyday tasks like at work. Academic knowledge is not. There are ways to help the individual bridge the gap and make connections between the two. For example, an introductory writing class might show differences in practical and academic. The adult learners will also need a detailed syllabus. A set of instructions are very important. Adult learners are very goal oriented and need to see a light at the end of the tunnel. Educators need to use strategies to invite the adult learner to want to learn. Using these strategies make it easier to adapt to a cognitive and critical thinking mindset. Article 2 Adult learning Theory for the Twenty-First Century Educators want to help facilitate learning. They must learn more about their students in order to do this through â€Å"embodied learning, spirituality, and narrative†. (Merriam, pg 93) Adult learning is a very complex problem and cannot be boiled down to something simple. It is forever changing. There have been many advances since Mezirows idea of transformational learning. (Merriam, pg 94) A bigger value has been placed on exactly where the education is taking place like work, home, and school. There are numerous factors that can affect each place like size, lighting, and background activities. There has been an increased attention to learning context. There finally has been an acknowledgment that learning is a â€Å"multidimensional Phenomenon†. (Merriam, pg 95) It used to be that learning was taking in facts and converting it to knowledge. Now it is said that learning involves the body, mind, spirit, and emotions. The mind (brain) changes when it is in learning mode. There is a mind body connection. There is also a connection between life experiences and mental capacity. Reflection I have read both articles completely. For the most part, I feel that they adequately describe the adult learner. There are many options that one could use to apply this to their own lives. Personally, the article Adult Learning Theory: Applications to Non-Traditional College Students really hit home. I fall into almost all of their categories. I have a full time job and even though I haven’t lost my job yet, I feel that a college education can help me further my career. From the working standpoint, repetitiveness of my daily tasks does not contribute to a higher standard of learning. I also fall into the category for veterans. I was in the Air force for 7 years. I can relate to military veterans. Most of them are deployed a long time and school is not an option. Most of them choose to wait till they get out to start school. I had to wait from 2003 till now to get started in school and the gap in education is killing me. Liberty University has a fantastic grasp on what I need personally to succeed in school. The articles touch base on starting school with the right mind set and environment. With the gap in education that I have it was important to see the correlation between beginning (starter) classes and making the connection between practical knowledge and academic knowledge. This will really help me. A detailed syllabus helps me keep track of what’s due and when I need to turn it in. I took it a step further and made a calendar of assignments and turn in dates. My wife has also been enlisted in keeping me on the right path and on time. One of the articles spoke about adults being goal oriented. This is absolutely right in my case, and is a product of my own design. I need to see an end to a means. There has to be a light at the end of the tunnel for me. The article gives the impression that goal orientation is a downside to learning and I do not agree. The second article honestly was a bad choice. There was not a lot of information on how I can improve on my adult learning. It was more of a generalization about another publication than actual facts. Having said that, we will see if there is anything that I can use The article states that adult learning is very complex. I could not agree with them more. In an average day, I work 9 hours at my job, come home, start dinner, run errands, and spend quality time with my son. It is hard to find time for studying and course work. The thing that it is not just the time constraints that get me. My environment does not help in any way. It’s dimly lit and has a loud surrounding. This makes it a little hard to concentrate. If I had a bad day at work then I probably won’t be in the right mood to study. Over all, both articles were helpful in understanding the dilemmas that an adult learner faces. Institutions of higher learning have a grasp on how to cater to these individuals. Although each person is different, instituting the best practices works well for adult learners. Dustin Stamey References Kenner, C Weinerman J, (Spring 2011). Adult Learning Theory: Applications to Non-Traditional College Students. (41. 2), pp. 87-96 Merriam B, S. , (2008). Adult Learning Theory for the Twenty-First Century. . 2008 (Issue 119), pp. 93-98 How to cite Inft Adult Learning Theory, Essay examples

Biological Viruses All Time Enemies Essay Example For Students

Biological Viruses: All Time Enemies Essay First came fever. Then Hamid Mansaray, a young nurses aide at a remote African hospital, began to hemorrhage. Blood erupted from his nose and mouth. It burst out of capillaries beneath his skin and eyes. By the time I reached the village of Panguma in Serria Leone, Mansaray lay isolated in a special ward. Doctors had diagnosed an obscure illness called Lassa fever. Its cause was a virus, an infective agent so small that 100,000 of them clumped together would still scarcely be visible. Viruses are little more than bundles of genes strands of DNA or RNA, the molecules that carry the blueprints for all life. Yet viruses are far from simple. They invade are cells, causing ailments such as the common wart, as irritating as a cold, or as deadly as this bloody African fever (Jaret, pp. 64). Viruses attack the body by taking over the cells of the body itself, some can be defeated by the bodys white blood cells alone, but for others a cure is yet to be found. Viruses:Viruses are obligate intercellular parasites, particles composed of genetic material (DNA or RNA, but not both) surrounded by a protective protein coat. Outside a host cell, they are inert; inside, they enter a dynamic phase in which they replicate, pirating the host cells enzymes, nucleic and amino acids, and machinery to accomplish what they are not equipped to do alone. Viral replication is often carried out at the expense of the host: diseases such as herpes, rabies, influenza, some cancers, poliomyelitis, and yellow fever are of viral origin. Of the estimated 1000 to 1500 types of viruses, approximately 250 cause disease in humans (over 100 of which cause the common cold), and 100 infect other animals (Microsoft Encarta 96 Encyclopedia).For these reasons and many more Virus, fittingly, is derived from the Latin word for poison. Viruses are very simple in structure, consisting only of genetic material surrounded by a protective coat. The name was originally used in the 18 90s to describe things that caused diseases but were smaller than bacteria. Viruses on their own are actually practically dead, but when associated with a living cell they can replicate many times, most of the time harming its host in the process. There are hundreds of known viruses that cause a very wide range of diseases not only in humans, but also in animals, insects, bacteria, and plants. The existence of viruses was established in 1892. A Russian scientist named Dimitry I. Ivanovsky discovered what was later to be known as the tobacco mosaic virus. However the name virus was not used to describe these infectious particles until 1898 by a Dutch botanist named Martinus W. Beijerinck. Shortly thereafter viruses were found growing in bacteria, and later named bacteriophages. (Microsoft Encarta 96 Encyclopedia)T4 Bacteriophage:This colored transmission electron micrograph shows a T4 bacteriophage, a virus that infects only bacteria (and in this case only Escherichia coli). Phages lack any reproductive machinery and rely on the apparatus of bacteria in order to replicate. They do so by attaching to the cell wall of the bacterium with the spidery tail fibers visible here. The tail is a sheath that contracts to inject the contents of the head, the genetic material (DNA), into its host. Within 25 minutes of infection, the bacterial apparatus successfully commandeered, viral p rogeny fill the cell. The overcrowded bacterium bursts, releasing approximately 100 new copies of the bacteriophage (Microsoft Encarta 96 Encyclopedia). Then, in 1935, an American biochemist by the name of Wendell Meredith Stanley crystallized the tobacco mosaic virus and discovered that it was actually composed of the genetic material ribonucleic acid, or RNA. By the 1940s viruses had still yet to be seen, but this was made an actuality with the development of the electron microscope. This was followed quickly by the development of high-speed centrifuges which were used to concentrate and purify viruses. The study of animal viruses reached a major point in the 1950s when methods were developed to culture cells that could support virus replication in test tubes. By this method numerous viruses were discovered, and in the 1960s and 1970s most were analyzed to determine their physical and chemical characteristics. Viruses undergo two different cycles of reproduction. The Lytic cycle and the Lysogenic cycle. (Microsoft Encarta 96 Encyclopedia)Lytic and Lysogenic Cycles of a BacteriophageAll bacteriophages (viruses that parasitize bacteria) have a Lytic or infectious cycle, in which the virus, incapable of replicating itself, injects its genetic material into a bacterium. By pirating its hosts enzymes and protein-building capacities, the virus can reproduce and repackage, making about 100 new copies before it bursts from and destroys the bacteria. Some bacteriophages, however, behave differently when they infect a bacterium. The injected genetic material instead integrates itself into its host DNA, passively replicating with it to be inherited by bacterial daughter cells. In about 1 in 100,000 of these Lysogenic cells, the viral DNA spontaneously activates and starts a new Lytic cycle (Microsoft Encarta 96 Encyclopedia). Yemen: Developing a Country EssayHepatitis B, previously known as serum hepatitis, has only been recognized since World War II. It is epidemic in parts of Asia and Africa. Hepatitis B is transmitted by injections transporting a virus-bearing serum, most often during blood transfusion, and by contaminated needles and syringes. For a person who has been accidentally stuck by a needle contaminated with the virus, administration of gamma globulin containing antibodies to the virus greatly reduces the chance of contracting the illness. The virus is also present in other body fluids and can be transmitted by sexual contact. In 1965 B. Blumberg, an American physician, found a viral component called the Australia antigen that determines whether a sample of blood can transmit hepatitis B. All samples of blood intended for transfusion are now routinely tested for the antigen; this has greatly reduced post-transfusion hepatitis. Hepatitis C and D are considered Non-A, and Non-B Hepatitis. Hep atitis C, transmitted in blood or body fluids and caused by a virus which has now been cloned, is the most common cause of post-transfusion hepatitis. Hepatitis E is transmitted in impure drinking water and can cause an epidemic form of non-A, non-B hepatitis. Another common virus is rabies. (Microsoft Encarta 96 Encyclopedia)Rabies Virus:The rabies virus is usually transmitted to humans by a bite from an infected dog, but the bite of any animal (wild or domestic) is suspect in an area where rabies is present. In North America, skunks are the principal carriers of the disease, although the raccoon and bat populations are also affected. Symptoms of the disease appear after an incubation period of ten days to one year and include fever, breathing difficulties, muscle spasms, and in later stages, an irrational fear of water. Death almost invariably occurs within three days to three weeks of the onset of symptoms. For this reason, the emphasis of treatment is on prevention. In the Unite d States, domestic dogs are vaccinated yearly and stray dogs are killed (Microsoft Encarta 96 Encyclopedia). Rabies is an acute, contagious infection of the central nervous system, caused by a specific virus that enters the body through an animal bite. All warm-blooded animals are vulnerable, but in North America the disease is most common in skunks, foxes, bats, raccoons, dogs, and cats. Most of the cases of rabies in humans are caused by the bite of one or another of these animals. The infection period in humans varies from three weeks to 120 days, with an average of about four to six weeks. Rabies is almost always fatal when a vaccine is not given. There are even smaller infective agents than viruses called viroids. Viroids are tiny infectious particle that causes disease in higher plants. Viroids are less than one-tenth the size of the smallest known viruses. Unlike viruses, which can contain either RNA or DNA, viroids consist solely of RNA. Viroids are even more different then viruses by their lack of a capsid. Although viroids can be transmitted from one plant generation to the next and, by means of farm implements, from one plant to another, their method of replication inside the cells of a plant is not understood. Some of the symptoms are, infected plants show slowed or stopped growth and discoloration and may eventually die. As long as viruses are still attacking humans and other organisms, scientists will be constantly looking for cures. BibliographyEbola Virus Hemmorrhagic Fever: General Infection. . Available http://www.cdc.gov/ncidod/diseases/viralfvr/ebolainf.htm, Nov. 20,1996. Electron Micrograph Library: DNA, DNA protein complexes and Virus. .Available http://phage.bocklabs.wisc.edu/, Nov. 3, 1994. Genital Herpes. . Available http://web.bu.edu/COHIS/std/herpes.htm, Nov. 22,1996. Jaret, Peter and Kasmauski, Karen. National Geographic. Vol. 186, NO. 1. WashingtonD.C. National Geographic Society. July 1994. Levine, Arnold J. Diagram of Infection Cycle of Influenza Virus. . Availablehttp://www.cdc.gov/ncidod/diseases/flu/infect.htm, Nov. 20, 1996. Protists and Viruses. . Availablehttp://www.csuchicu.edu/~pmaslin/fbiol/prtsurs.html, Feb. 23, 1996. Rabies: Encephalitis. . Availablehttp://indy.raidology.uiowa.edu/Providers/TeachingFiles/CNSInfDisR2/text.html, Jul. 12,1995. Varicella / Chicken Pox Dew Drop on a Rose Petal. . Availablehttp://tray.dermatolgy.uiowa.edu/Varicel-02.htm, Sept. 1995. Viral Pneumonias. . Available http://www.cdc.gov/ncidod/diseases/hip/pneumonia/1_viral.htm, Nov. 20,1996. Viral Structure ; Classification. . Available http://virology.science.org/, Nov.20, 1996. Viruses. Microsoft Encarta 96 Encyclopedia. Redmond, WA. Microsoft Corporation.1995.