Importance of Trees Essay Example for Free

Importance of Trees Essay Trees are the largest and longest living organisms on earth. To grow tall the tree has become a miracle of engineering and a complex chemical factory. It is able to take water and salts out of the earth and lift them up to the leaves, sometimes over 400 ft above. By means of photosynthesis the leaves combine the water and salts with carbon dioxide from the air to produce the nutrients which feed the tree. In this process, as well as wood, trees create many chemicals, seeds and fruit of great utility to man. Trees also remove carbon dioxide, the main greenhouse gas, from the air. Trees are of continued importance to the environment. Tropical rain forests have of particular significance; although they now occupy less than 6 per cent of the land surface of the earth they probable sustain more than half of the biological species on the planet. Notwithstanding the debt we owe to trees, their emotive power, and their importance to other forms of life, the forested area of the earth is steadily being depleted. This is leading to the degradation of the environment and the extinction of many species. There is now a real danger that in the not very distant future man will destroy a large proportion of the present population of species on earth, create an uninhabitable environment, and then die out himself. If this happens it will not be the first time that a large proportion of the species on the earth have been extinguished. Trees are our best friends. They play a very important role in our life. We can not live without them. They give us timber, paper and firewood. Timber is used in making houses, train compartments, big boxes, tools etc. Without paper life may be difficult for us. Paper is necessary for study and writing. People in villages use firewood to cook meals. They use wood to build houses, huts, carts and agriculture tools. Trees also give us food, gum and medicine. They also add to the beauty of life. Gardens can not be charming without them. We need them for oxygen and good health. Trees also help to control pollution: They absorb carbon dioxide. They improve our environment. They cause rainfall and protect water resources under the ground. They prevent floods and droughts. Therefore, we should try our best to grow more trees. Govt. and social welfare societies should start a movement. There should be awards for those persons who grow more trees. The Importance of Your Trees Trees are natures air conditioners. In one year the average tree inhales 26 pounds of carbon dioxide, the amount emitted by a car on an 11,000 mile trip.

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1. Guided bone regeneration (GBR) The concept of GBR was described first in 1959 when cell-occlusive membranes were employed for spinal fusions 105.The terms ‘‘guided bone regeneration’’ and ‘‘guided tissue regeneration’’ (GTR) often are used synonymously and rather inappropriately. GTR deals with the regeneration of the supporting periodontal apparatus, including cementum, periodontal ligament, and alveolar bone, whereas GBR refers to the promotion of bone formation alone. GBR and GTR are based on the same principles that use barrier membranes for space maintenance over a defect, promoting the ingrowth of osteogenic cells and preventing migration of undesired cells from the overlying soft tissues into the wound. Protection of a blood clot in the defect and exclusion of gingival connective tissue and provision of a secluded space into which osteogenic cell from the bone can migrate are essential for a successful outcome. The sequence of bone healing is not only affe cted by invasion of non-osteogenic tissue, but more so by the defect size and morphology. A predictable intraoral GBR approach was developed in the late 1980s and early 1990s; 108-110 (bone augmentation techniques 2007) The survival rates of implants placed in augmented sites with GBR are reported in many publications, survival rates range from 91.7 to 100%. However, there are few data about the success rate of dental implants placed in those areas, according to universally established criteria. This may represent a limit in evaluating the reliability of the GBR technique, because a high implant survival rate may not correspond to a high GBR success rate bearing in mind that an implant can remain stable and osseointegrated even if the total amount of regenerated tissue ... ...nd limitations must also be being considered. Some authors have reported partial relapse of the gained bone. More studies are needed to assess the implant survival in the bone gained by DO versus other augmentation methods, including new bone substitutes and augmentation factors. (Alveolar ridge augmentation for implant fixation: status review zakhary 2012). Determination of what technique should be used, is largely surgeon preference and on the extent of the defect and specific procedures to be performed for the implant reconstruction. It is most appropriate to use an evidenced-based approach when a treatment plan is being developed for bone augmentation cases. (Bone augmentation techniques. 2007)(Clinical outcomes of vertical bone augmentation to enable dental implant placement: a systematic review.2008) (Bone Grafting the Mandible Patrick J. Louis, DDS, MD 2011)

Craig Lockhart Essay

Wilfred Owen was a soldier in the First World War; in 1917 he was admitted to Craig Lockhart hospital with shell shock. He had previously written poems pre 1917 but whilst in the hospital he met Siegfried Sassoon; Sassoon had a huge influence on the way Owen wrote his poems. Owen’s main message in his poems was ‘to warn’ the public about war, as well as dis-agree with other writers such as Jessie Pope and Rupert Brooke who presented war as noble; Owen was completely against this idea of war, especially the message these other writers tried to convey. In Owen’s poem ‘Exposure’ the readers’ expectation is reversed; we expect the poem to be about exposure to enemy fire but what the men in the poem are really exposed to is the weather; this weather will eventually kill them as they die from hypothermia. In the poem the men are suffering from psychological trauma; ‘projecting’ their own madness onto nature. The reader starts to sense Owen’s own questioning of his religion, Christianity, as he can no longer believe there is an after life and presents his theme of the futility of war. The opening of ‘Exposure’ establishes the theme of psychological trauma, which is a reversal of the reader’s expectation because we expect the men to be ‘exposed’ to enemy fire; this is the first thought the reader had when thinking about ‘Exposure’. The opening line of the poem is ‘Our brains ache’, which signals to the reader a new idea and a reversal of the original expectation we have and we sense the men are ‘worried by silence, sentries whisper, curious, nervous’. The word ‘Our’ shows that collectively their ‘brains ache’ and suggests the idea of the universality of war and the fact that on both sides, the British and Germans, many men suffered from psychological trauma. Another idea could be that the men are constantly worried (paranoia) about being heard or coming under attack, hence their ‘brains ache’ with worry. Also, the use of sibilance throughout the opening creates an uneasy atmosphere and we can sense that the men themselves are uneasy; the sibilance creates a whispering sound; this constant paranoia surrounds the men that if they talk too loud they will die, which in turn creates psychological problems. This conveys the, perhaps uneasy, horror of war because what if affecting the men the most is not the constant ‘Exposure’ to enemy fire but the constant fear that they are going to be shot at. ‘Spring Offensive’ confirms Owen’s sincere lack of faith in an ‘after life’ as he questions God’s existence throughout the poem. He suggests that the hundreds, perhaps thousands of men are not going to heaven as some would like to believe but simply just dying. The consolatory myth that many once used to believe is forgotten on the front line, as the men can no longer believe in the existence of such entity. Owen suggests that there is no Christian ‘Heaven’ or ‘Hell’ but that man have created a hell on earth; there is constant dying and murder yet these men do not go anywhere. This highlights that perhaps this is the most poignant horror of war, the futility of war. In ‘Spring Offensive’ the theme of psychological trauma is again established in the opening stanza; the idea of the futility of war is also introduced. ‘Many there stood still to face the stark blank sky beyond the ridge’, shows that the men are perhaps afraid of going ‘over the top’ for the fear that if they die they will go nowhere, no heaven or hell. Owen’s own fading belief in religion and an afterlife is introduced. The men in the poem are scared about what they are going to face when the go over the ridge (trench), as they have problems with what they are going to have to do when they go over the top of the ‘ridge’; they do not like the idea of killing over people. The use of sibilance is used in the poem, as in ‘Exposure’, to effectively create a sense of unease. This is a contrast to those who ‘carelessly slept’ as they do not mind killing others in order to save themselves and at the end of ‘Spring Offensive’ we learn that these were the ones who, eventually, survived. This perhaps suggests that they themselves have no social conscience in that they are quite happy to kill human beings like themselves and perhaps have psychological problems of a different kind. The ‘stark blank sky’ could also, perhaps, be a link to astrology, with the idea from the past that the sky could show you what was in store for you in the future. A sunny day would suggest something good would happen to you and you would be fine, for example. However, the fact that they ‘face the stark blank sky’ could be because they have no future, this is the end of their lives and that their own future is stark, blank; there is no hope of them going to the Christian ‘Heaven’ or ‘Hell’, as Owen is trying to suggest that neither of these places exists, which strengthens the reader’s idea that Owen has a lack of belief in Christianity. The idea that the men are ‘stood still’ is also a link to ‘Exposure’; the men are passive in the war in that they cannot affect what is going on, which also presents the theme of the futility of war. In the opening of ‘Spring Offensive’ Owen successfully presents the themes of the futility of war and of psychological trauma and starts to establish his own belief that there is no such thing as ‘Heaven’ or ‘Hell’ in a subtle but effective manner. In ‘Exposure’ the men ‘project’ their own madness onto the wind and have a strong belief that nature, especially the wind, is against them; this comes from their psychological problems. Owen personifies the wind when he says ‘winds that knive us’ and the men start to think of the wind as ‘mad gusts’, as well as suggesting that the bullets being fired at the men are ‘less deadly than the air’.

The Great Depression Was Caused By The Stock Market Crash

The Great Depression was the deepest and longest-lasting economic downturn in the history of the Western industrialized world. Many people believe that the great depression was caused by the stock market crash, this is not the case. The stock market crash revealed the structural flaws in the economy, but it did not cause the depression; it was merely one of its many symptoms. A healthy economy can recover from such a contraction. There were several other factors that contributed to the onset of the Depression Government policies throughout the twenties e.g. high tariffs, which discouraged foreign trade, lax enforcement of anti-trust laws, an absence of checks on speculation in real estate and the stock market, and adherence to the gold†¦show more content†¦For the U.S., people began to realize they were in a depression after several events. The first being the stock market crash, because their saving began to drop or disappeared completely with the closing banks, as a result defaults and bankruptcies fed deflation. For those who were still in the mindset of this won’t happen to me and ignoring what was right in front of their faces, the nation’s money shrunk by a third, which in turn, drove prices and production down, they began to open their eyes when their wages and hour were cut. It was the most catastrophic economic event in U.S. history. Those who were able to keep their jobs noticed a significant decrease in their hours and wages. The contraction of the economy squeezed debtor, especially farmers and laborers who made installment purchases or mortgages. By 1933, thousands of Americans lost their homes to foreclosures. Factories shut down, banks closed, farms went bankrupt, millions of people found themselves jobless, but homeless and destitute as well. Those who were desperate for food rummaged through trash cans behind restaurants. There were those who took up shelters in in vacant lots or slept on park benches and in alleys. Hobos and tramps snuck on empty railway cars going from town to town searching for jobs. During the winter to keep warm they would cover themselves with newspaper. For those who