In botany, a tree is a plant with an elongated stem Essay Example for Free

In botany, a tree is a plant with an elongated stem Essay In some usages, the definition of a tree may be narrower, including only woody plants, only plants that are usable as lumber, only plants above a specified height or only perennial species. At its broadest, trees include the taller palms, the tree ferns, bananas and bamboo. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into chemical energy by photosynthesis, providing the food needed by the tree for its growth and development. Flowers and fruit may also be present, but some trees such as conifers instead have pollen cones and seed cones, and others such as tree ferns produce spores instead. Trees tend to be long-lived,[1] some reaching several thousand years old. The tallest known specimen on Earth is 115.6 m (379 ft) and they have a theoretical maximum height of 130 m (426 ft).[2] Trees have been in existence on the Earth for 370 million years. Trees are not a taxonomic group but are a number of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants and make full use of the sunlight. Trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are one of the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture. Because of their longevity and usefulness, trees have always been revered and they play a role in many of the worlds mythologies.

Consider It Cured Essay Example for Free

Consider It Cured Essay Our caned, very anti-social doctor is in the house. He is not interested in simple medical cases. He loves to solve medical cases that are highly mysterious. He is not a people person. His talented, young medical staffs; his oncologist best friend; the hospital administrator; and even his patients do not escape our doctor’s â€Å"rudeness. † In spite of his not â€Å"very good behavior,† our doctor’s capability to treat mysterious medical cases prove to be indispensable. His expertise is highly respected by his colleagues. That even though our doctor is treating them (medical staffs, oncologist best friend, hospital administrator, and patients) â€Å"harshly,† they could not thank him enough for his great medical ideas. You know who I’m talking about. He is the famous Dr. Gregory House of the TV series Dr. House M. D. The â€Å"success† of the series is not only attributed to Dr. House but to everyone in the house. This medical drama is just one of the many medical dramas that are taking the limelight. These medical dramas expose us to what is happening inside hospital institutions. Or let me be more specific, these medical dramas more or less expose us to different hospital scenarios. Have you been hospitalized? If not, have you been in a hospital? Have you seen real â€Å"actions† in hospitals? Have you seen the commotions of the doctors, nurses, and other medical staffs? Or your ideas on hospital scenarios are based only on medical television dramas? Are these medical dramas happen in real life? Are all mysterious medical cases always solved? Is it true that most patients of mysterious medical cases always survived? What are the real scores in hospitals? What is the real situation in hospitals with actual patients, in hospitals not seen in the limelight? I had been in a hospital several times, visiting a sick member of my family. To be honest, I have never seen an actual breathtaking scenario during those visits. This is good news though. Remember Rescue 911? I used to watch this show because it’s informative. I learned some medical tips. I was able to see actual footages of rescue operations and first aid application. Rescue 911 was able to show the actual procedures on saving patients in cases of emergencies. No doubt, Dr. House is a â€Å"good† doctor in the series. Good† doctor because he has helped a lot of patients. Are all real-life doctors as good as Dr. House? Are all real-life doctors able to treat most of their patients? Do you think medical dramas have changed the image of real-life doctors? Are these changes advantageous or disadvantageous to real-life doctors? How have medical dramas influenced real-life medical cases? More often than not, viewers of medical dramas treat these as real events and situations. These medical dramas affect the way people think of medical cases. Another fact, these medical dramas have changed the image of real-life doctors and nurses. Some might find Dr. House’s qualities to real-life doctors. Others might think that all medical cases are treatable and that most patients can survive any life-threatening situations. Because doctors and nurses in medical dramas are really good (I’m not saying that real-life doctors are not good), some real-life patients expect that nothing is impossible to our real-life doctors. Too much expectation could fail them. Because in real-life, not all diseases are treatable and not all patients can survive. Again, I’m not saying that our real-life doctors are no good. There are many patients too that are treated and survive, and we can credit these successful medical cases in our real-life medical experts. Let me just remind you that the medical dramas we watch are fictional, meaning there is a deviation from the actual situation. These medical dramas are products of very creative and imaginative minds. Thus, these medical dramas are designed to entertain us, not to change the way we think about our real-life doctors. Aside from the entertainment we get in watching a medical drama, the end of each episode often gives us a relief because, our Dr. House did it again. He made the patient, and his or her family, happy. The happy endings make the viewers happy also. Medical dramas could be informative, but we should not get carried away. Best to consult real-life doctors than our medical dramas’ doctors. Here is another should be avoided situation. Medical dramas might influence some patients to rely on the medical dramas’ diagnosis on certain diseases. Again, this is a big NO, NO. Should we find ourselves sick, better visit our doctor and have him/her examine you. Our real-life doctors are the ones authorized to give diagnosis and to give the prescribed medication. Though medical dramas are products of fiction, they are not totally wrong. Directors of these medical dramas consult the expertise of medical practitioners to make the episodes more realistic. Since the lead actors and actresses are not really medical practitioners, to whom are we going to put our confidence if our health condition is at risk? Real-life doctors have undergone lots and lots of training before they could earn their first patient. Medicine is not the normal four-year college course. Sick persons entrust their lives to real-life doctors. A sick person who is admitted in hospitals is hoping that doctors could ease his or her pain, that doctors could cure his or her illness, that doctors could add more years to his or her lives. A doctor has great responsibilities to his or her patients. The experiences of real-life doctors are countless. Each experience has taught them how to become effective and efficient doctors. Survival of the fittest could very much explain how a doctor earned his or her title. Many say that to become a doctor, one has to be very brilliant and very knowledgeable. The truth is, brilliance and knowledge are not enough. Aspiring doctors need a lot of courage, patience, and a very healthy body to withstand pressure and long hours of study. Compare the long hours of medical trainings or real-life doctors to our medical dramas’ â€Å"doctors. † We all know that good actors perform and act well. Good actors should portray their roles effectively for the success of the show. We can prove the effectiveness of an actor’s portrayal when the audience believe and trust him. Same is true for the actors-playing doctors in medical dramas. In fact, they are very good actors. I have no doubt for that. Why? Because some viewers believe in them. Because their portrayal is good, some viewers think of medical dramas as fiction. How long are these actors trained to become â€Å"good† doctors in their medical dramas? Are these long hours of training justifiable enough to trust their diagnosis? With the long years of medical trainings, how come that there are still mortality? How come real-life doctors could not cure all their patients? Recall that Dr. House loves to handle mysterious medical cases. In the event of these mysterious medical cases, not all doctors are successful in finding the correct diagnosis. Like in medical dramas, real-life doctors are also doing their best to save their patients. Like in medical dramas, real-life doctors are also frustrated when their patients die. Like in medical dramas, real-life doctors share with their patients’ happiness after a successful operations or treatments. The day to day events in most city hospitals are not boring. Real-life doctors and nurses are very busy. They could be handling two or more medical cases at the same time. Real-life doctors treat real-life patients. Real-life doctors encounter real-life illnesses. Real-life doctors are always on the move. Since they are in the real-world, they are portraying the role of real-life doctors. The real-life doctors are not the cast of a fiction medical drama. With real-life doctors, we are talking about real or non-fiction medical dramas. These medical dramas are the real ones––the stories of patients who survived and those who do not; and the stories of doctors who continuously serve the needs of sick people. Medical dramas on television have affected the viewers’ point of view in terms of medical issues. This is true to some viewers. There are still viewers who know the difference between fiction and non-fiction; viewers who know what to believe; and viewers who live on reality. But we should bear in mind that when in comes to one’s health, the best person to consult to are medical practitioners. Also bear in mind that fiction can never become non-fiction. Medical dramas can never be applied to real-life situations. There is a big difference between those medical dramas and the real-life situations in hospital. There are no points for comparison because giving entertainment (like what medical dramas do) is totally different from giving treatment and taking good care of humanity’s health (like what doctors do). The main goal of medical dramas, like any other television shows, is to entertain. If they want to educate the viewers, that is another story. But still, we have to choose who to believe. Remember, life is at stake here. We are not doctors to take a risk. Real-life doctors know best.

Pressure of Teenagers Going to College

Pressure of Teenagers Going to College While adolescents are attempting to focus on graduating secondary school, they are being forced into focusing on school too. A developing heap of school applications, handouts and homework expend the space on a youthful teenagers work area, he or she is guaranteed that school is the most ideal approach to keep up an existence and have a decent profession. As this may be true, but what about the teens personal life or the financially situation they or the family may be facing. Most secondary school understudies have that vitality say something regarding them amid late night thinks about. Verifiably the endeavor to keep up fabulous evaluations and pass secondary school to make it in school puts a great deal of weight on any single individual. The more one ponders this subject, the more insane the procedure of school applications gets to be, which makes one wonder of if American culture is putting excessively to much weight on students to even attend college. The answer to this question , of course, is yes. Americas desires to contend in a worldwide economy is setting superfluous weight on secondary school children, and this is taking an impossible enthusiastic toll on the youthful. Because of such demand for high school graduates to attend college, they do the best to strive to make the grades and give there all to go to the best college usually find themselves in a huge pile of debit by the time the graduate college. Most understudies who can scarcely hold up or dont get a full ride offer, need to take out credits to manage the cost of a semester. Costs for classes and course books are at an untouched high, and with the ultimate objective for understudies to deal with the cost of a living while going to class full time is by having a fulltime work too. This tip top passes on more worry to the lively adolescent who was told life would be better subsequently. It is basic to see how this impacts a young person on all levels of their juvenile life. A youth can wind up being genuinely, soundly and physically insecure as they may feel less on themselves. Thus it can demolish the connections they have with family as well as the social connections they attempt to keep up, which can figure musings of suicide or real damage as the juvenile probably cant accept the obligation at the same time. It may not be that gigantic in the U.S, yet rather in various countries around the world it is in every way an ordinary thing to do, like Japan. Regardless of a juvenile preparing to join school, there are many blended emotions they may understanding. School classes accompany a more work and request than secondary school. It makes you wonder if youre ever fully prepared for college. There is that energy of knowing you will be far from home, making new companions, and joining school societies and sororities, in spite of the fact that a normal young person will as often as possible fight with fixation issues in the respects of having the capacity to stay aware of their reviews and social life in school. For a few young people, basically being set up for advancement may be a test. As coming up short with respect to time organization and begin they will get the opportunity to be particularly delicate and feel the heaviness of falling behind. Hence the fear of finally crashing and burning can startle the hellfire out of any understudy. The noteworthy fear of failing begins from being ones own specific extreme analyst. Consistently the beginning start of any mentoring will be outrageous at to begin with, and when you feel you endeavor your best and still come up short, you then begin to denounce yourself. From this time forward an understudy begins to that if they crash and burn not solely are they letting themselves down, feels that they may have perplexing everyone around them. Deplorably the weight that most gatekeepers and educators put on understudies causes the come up short with respect to themselves. As a result to this, an understudy will create loss of enthusiasm for specific matters of life, will create dietary problems, and lack of sleep. So then begin to stress a great deal, withdrawal themselves from family and companions, separate from individual connections and wind up creating tension, which thus can make them decline to backpedal to class. Brought about by placated push an understudy will start to feel a need in self-regard. They begin to feel the hugeness of making new accomplices or endeav oring to move past cooperations they double-crossed for school. They observe the workload to overpower and sense of self shattering. With these new difficulties comes low self-regard. When one has been less effective in the past might begin to feel that are not school material. (CB Staff 1) With so much pulling on them, they become particularly susceptible to social pressure. Adolescents make a legit imagine to space in a chose social condition which may push fundamentally inside the occasion that they dont opening in. They should be famous and have paying little heed to range mates and supporters as may well be typical underneath the conditions. Occasionally theyll discover yourself in hazardous instances wherever they need to decide on extreme selection. College can be a breeding ground for psychiatric problems. Poor eating habits, irregular sleeping patterns and experimentation with drugs and alcoholespecially combined with the academic stress of college lifemay all play roles in triggering mental problems. Such selection is distressing. Guardians, educators and even school guides feel that every youthful should instantly go to class straightforwardly after auxiliary school. The likelihood of our present people was always seen as a place of graduation movement, which is no longer an open entryway or advantage, yet in a perfect world a need. We are once in a while raised and pre-demonstrated that we ought to accept an exceptional prerequisites for a propelled educational activity with the ultimate objective for us to manage a more invaluable money related condition additionally not far off. Times of Americans have used school as an agreement to a predominant inconceivability, not infrequently in doubt of money under the table, yet by a comparable token in stipulation of a higher pickle of life. That could display work guarantee, ideally social portability, or the benefit to manage the cost of vital things welcome a house. Getting a specialist guideline gives you that vital tranquility that you can have adaptability in side your occupation, or when the economy transforms you can progress and change with it. While making money, which thusly can help you keep up a home and family life when youre prepared. One essential indicate this question is more noteworthy open door. As abutting stop of the stallion and Surrey day, an unreasonably high value school day alumna today are weakened to make the zone of lucrative jobs that were a significant long time prior open. The U.S. has been changed from an assembling situated in embellishment to an exposed state in view of way of life, and the force of a position of graduation headway today slice back be contrasted with that of an important school training forty a very long time prior. It constitute the net get right of entry to supplier to upward thrust above selections and greater noteworthy open door. The oppositions point may be valid as it is the standpoint of our economy and the difficulty of good job positions increasing. Completion for a higher job is a huge growth in nowadays society. Regardless, there is developing uneasiness in America about advanced education. A degree has dependably been regarded as the way to a great employment. Nonetheless, growing prices and extending understudy commitment, joined with contracting cash associated and educational returns, are undermining at any rate the perception that school is a not too horrific speculation. (Chicago 1) Snice 2008 the economy has been fluctuating at an all-time low. Jobs are tougher to get, and are also limiting how many employees they need to hire, which means less jobs. They look more at your accolades than experiences and most require a type of degree such as a bachelors or PHD. The reality here is that adolescents are in their most defenseless stage in life when they complete secondary school and need to settle on an existence adjusting choice. Choosing whether they ought to proceed with their instruction or begin searching for a vocation is a to a great degree troubl esome and upsetting choice all alone. On top of it, the overall population, their people and teachers persistently push them to enhance, compelling them to enroll in school and achieve simply high results. This, solidified with the fear of the dark make understudies focused and decimates their dauntlessness. Teenagers are an energetic social occasion of people who stay before the most basic decision in their lives. Regardless of the way that guardians need the best for their youngsters, interfering in such choices can just damage the adolescents. Things being what they may be, younger human beings are really pressured to attend a university. A growing number of colleges nationwide are scrambling to fill classes, a trend analysts say is driven by a decline in the number of students graduating from high school and widespread concern among families about the price of higher education. The admissions upheaval at schools ranging from lower-tier colleges to esteemed regional ones, includi ng St. Marys College of Maryland, contrasts with the extraordinary demand for the most elite colleges and universities.Nationwide, college enrollment fell about 2 percent this past school year [2012-2013].The decline in prospective students and the enormous costs associated with running a college create a challenge for schools that rely on tuition to pay the bills. (Washington Post) Too much pressure on students to go to college even though Americas expectations to compete in a global economy is placing unnecessary pressure on high school kids. While young people are endeavoring to concentrate on graduating optional school, they are being constrained into concentrating on school as well. A creating load of school applications, presents and homework consume the space on an energetic youngsters work zone, he or she is ensured that school is the best way to deal with keep up a presence and have a fair calling. As this might be valid, yet shouldnt something be said about the youngsters close to home life or the monetarily circumstance they or the family might confront. Most secondary school understudies have that essentialness say something regarding them amid late night thinks about. Undeniably the attempt to keep up spectacular assessments and pass auxiliary school to make it in school puts a lot of weight on any single person. The more one considers this subject, the more insane the procedure of school applications gets to be, which makes one ponder of climate American culture is putting unnecessarily to much weight on understudies to try and go to school. Works Cited CB Staff Self-Esteem and the College Student College Bound Networkhttp://www.collegebound.net/content/article/self-esteem-and-the-college-student/19583/ Kelly, Kate. Lost on the Campus. Time, Jan, 2001, pp. 51-53, SIRS Issues Researcher, https://sks-sirs-com.db16.linccweb.org. Chicago Not what it used to be The Economist http://www.economist.com/news/united-states/21567373-american-universities-represent-declining-value-money-their-students-not-what-it Anderson, Nick. Freshmen Seats Going Unfilled at More Colleges. Washington Post, 23 Nov, 2013, pp. A.1, SIRS Issues Researcher, https://sks-sirs-com.db16.linccweb.org.

The Evolution of Electronic Court Coverage Essay -- Trial Justice Expo

The Evolution of Electronic Court Coverage A trial is a public event. What transpires in the court room is public property...There is no special perquisite of the judiciary which enables it, as distinguished from other institutions of democratic government, to suppress, edit, or censor events which transpire in proceedings before it.† Justice William O. Douglas, 19471 â€Å"Picture taking in the courtroom is more than disconcerting. It does not comport with the traditional notions of a fair trial. A man on trial for his life or liberty needs protection from the mob. Mobs are not interested in the administration of justice. They have base appetites to satisfy.† Justice William O. Douglas, 19602 These seemingly contradictory words from one of the most ardent First Amendment absolutists to ever serve on the United States Supreme Court stand as a testament to the central conflict which has for so long characterized the debate over press coverage in the nation’s courtrooms. In the battle for preeminence, which Amendment wins: the First or the Sixth? Does the freedom of the press and the public’s right for information outweigh the constitutional guarantee of a fair trial through due process? And in an era of mass communication, where the capabilities of technology are matched only by the pervasiveness of the message it delivers, how and where is the line ultimately drawn? Especially in the age of O.J. Simpson and Scott Peterson, of Michael... ...o the discovery of two additional court cases, Sheppard v. Maxwell 384 US 333 (1966) and Florida v. Zamora 422 So. 2d 325 (1982), as well the two major American Bar Association regulations relating to subject, Canons 35 and 3A(7). Information regarding current federal and state-by-state courtroom standards were found at the Radio-Television News Directors Association website (www.rtnda.org), the Indiana State Court website (www.in.gov/judiciary), and an archived statement made in 2000 by Third Circuit Court Justice Edward R. Becker to the Senate Committee on the Judiciary (judiciary.senate.gov/oldsite/962000_erb.htm). Also helpful were the American Bar Association website (www.abanet.org) and two sources for quotations from former Supreme Court Justice William O. Douglas: Craig v. Harney 331 U.S. 367 (1947) and 46 American Bar Association Journal 840 (1960). The Evolution of Electronic Court Coverage Essay -- Trial Justice Expo The Evolution of Electronic Court Coverage A trial is a public event. What transpires in the court room is public property...There is no special perquisite of the judiciary which enables it, as distinguished from other institutions of democratic government, to suppress, edit, or censor events which transpire in proceedings before it.† Justice William O. Douglas, 19471 â€Å"Picture taking in the courtroom is more than disconcerting. It does not comport with the traditional notions of a fair trial. A man on trial for his life or liberty needs protection from the mob. Mobs are not interested in the administration of justice. They have base appetites to satisfy.† Justice William O. Douglas, 19602 These seemingly contradictory words from one of the most ardent First Amendment absolutists to ever serve on the United States Supreme Court stand as a testament to the central conflict which has for so long characterized the debate over press coverage in the nation’s courtrooms. In the battle for preeminence, which Amendment wins: the First or the Sixth? Does the freedom of the press and the public’s right for information outweigh the constitutional guarantee of a fair trial through due process? And in an era of mass communication, where the capabilities of technology are matched only by the pervasiveness of the message it delivers, how and where is the line ultimately drawn? Especially in the age of O.J. Simpson and Scott Peterson, of Michael... ...o the discovery of two additional court cases, Sheppard v. Maxwell 384 US 333 (1966) and Florida v. Zamora 422 So. 2d 325 (1982), as well the two major American Bar Association regulations relating to subject, Canons 35 and 3A(7). Information regarding current federal and state-by-state courtroom standards were found at the Radio-Television News Directors Association website (www.rtnda.org), the Indiana State Court website (www.in.gov/judiciary), and an archived statement made in 2000 by Third Circuit Court Justice Edward R. Becker to the Senate Committee on the Judiciary (judiciary.senate.gov/oldsite/962000_erb.htm). Also helpful were the American Bar Association website (www.abanet.org) and two sources for quotations from former Supreme Court Justice William O. Douglas: Craig v. Harney 331 U.S. 367 (1947) and 46 American Bar Association Journal 840 (1960).

Cablevision Term Paper :: essays research papers

Introduction   Ã‚  Ã‚  Ã‚  Ã‚  For the past twenty years my family has been subscribed to Cablevision for cable services. I have enjoyed the eighty channels and special movie channels that they offer. The excellent service they have provided for many years only gets better. When Cablevision came out with IO digital cable my family upgraded. I no longer have to go out and rent movies. Instead I now order them from the television. Instead of eighty channels there are now hundreds of channels to choose from. The variety of things to watch on my television is unlimited. Many of neighbors that used to have satellite television were unhappy with the service. I recommended them to switch over to Cablevision. When they made the switch they were extremely pleased with the service. My family also uses their service of Optimum Online for our computer. We used to have a dial up service that took forever until we upgraded to Optimum Online. The internet is now extremely fast on my computer, and I have never had to wait for anything to load ever since. We also use Optimum voice which has so many options to use. There is enhanced voicemail, call waiting, and caller ID helps making phone calls better. I am a fan of the New York Rangers and the New York Knick’s in which Cablevision owns. Ever since I was a little kid I would wear jerseys of the Knick’s and Rangers and go to some of their games. Although I wish I had season tickets for both teams, I was still able to watch them play on television. Many people do not have the privilege of Cablevision’s services. Instead they have satellite television which they think is much better than Cablevision. However, they are extremely wrong in making that statement. My neighbor had satellite television for three years and was fed up with it after those years. The best time to watch a good movie is when it is raining outside and there is nothing to do. The only problem is that whenever it is raining or there is a storm outside, the satellite does not work properly. This causes everyone to be unable to watch television. With Cablevision you can watch you TV anytime you want without any interruptions. As you watch TV you can watch the Knick’s and Rangers play and call up your friends using Optimum Voice and tell them about the great service Cablevision offers.

Evolution of The Catholic Church :: Essays Papers

Evolution of The Catholic Church Over the last thirty years, the Roman Catholic Church has undergone changes. These changes range from the position of the Alter to the language of the Mass. This paper will illustrate a broad overview of changes in the Catholic Church after the 1960s Before the 1960s, Mass was said in Latin. The priests and the parish both knew the prayers, songs, and Scriptures in Latin. Around 1965, the Catholic Church realized that the people did not understand all of what they were saying. They began to do the Mass in English. This increased active participation. Today, if a person would want hear a Mass in Latin, they would have to do some traveling. For instance, Our Lady of Mount Carmel offers Latin Masses. A parishioner may go Monday, Tuesday, Wednesday, and Friday at 7:15P.M. or on Thursdays at 10:10 A.M. There is also a Saturday Mass at eight O’clock A.M. The Sunday schedule is thus, eight o’clock and 10:30 A.M. For more information, check out their web site. Http://www.archden.org/archden/parishes/pp150.htm Catholic schools have undergone significant changes also. It use to be that it cost nothing to go to Catholic schools. Now there is a splendid idea of tuition. Tuition makes it difficult for some families who would want to send their children to Catholic schools. Many kids end up in public facilities, for that very reason. Another difference is that the schools use to be run almost completely by nun, brothers, and priests. The institutions enforced a very strict dress code. Students were to wear their uniform to class. There is still a dress code, some schools offer a dress-down Friday. On this day, the kids may wear whatever they would like, within reason. Kindergarten is a new luxury. Many older people never went to Kindergarten, it was not offered. Years later, you could send your children to a public school for it. Now it is part of the curriculum. It is a very exciting attribute. Catholic schools have also experienced a significant increase if enrollment. Sister Catherine T. McNamee states that "this years total Catholic School enrollment of 2.

What is Drug?

A drug is any animal, vegetable, or mineral substance used in the composition of medicines. It also refers to any stuff used in dyeing or in chemical operations. It is a substance that is used as a medicine or narcotic. A drug is capable of altering natural biological processes, with their manipulating nature used in medicine as a corrective measure against deviances from these normal biological processes. As described in the Webster Dictionary (1992), a drug, is a substance, other than food intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals.It is any narcotic; also any substance or chemical agent, exclusive of food, employed for other than medical reasons to obtain a given physiological effect or to satisfy a craving. The drug affects the mind or body. The effect depends on the type of drug, the amount taken, when and how it is used, and the person who takes it (Webster, 1992). Drugs may be classified as uppers, downers, narcotics, mind-affecting (hallucinogens), or volatile chemicals. Uppers are stimulants that affect the nervous system to excite the user.Downers are depressants that affect the central nervous system to relax the user. Narcotics affect the nervous system, and change many of the normal activities of the body, and often produce an intense state of excitement or distortion of the user’s senses. Volatile chemicals are depressants acting upon the central nervous system. It is important for the first aider to be able to detect possible drug abuse at the overdose level and to relate certain signs to certain types of drugs (Webster, 1992 p. FA-28). There are four levels of drug use.Abstinence means not taking any drugs or any particular drug. Experimentation means trying a drug for the first time. It could be a doctor prescribing medicine, or a young person sniffing glue. If a user likes the effects of a drug, he or she may move to casual, recreational or regular use. Casual use is taking a drug only when a person feels like it or when a it is offered. Recreational use is a drug use for enjoyment in social situations. Regular use means taking drugs almost everyday. Habitual or problem drug becomes dependent (needs to have some of the drug everyday).The user may have very little control over his or her problem drug use. The effects of this dependence can be serious, and sometimes fatal. With certain drugs, the user can develop a tolerance, or get used to the drug. He or she has to take very large amounts to feel the same effects. These drugs include alcohol, opiates, LSD, caffeine, amphetamines and tranquilisers. Psychological dependence can develop with any type of drug. The user believes that he or she will not be able to lead a normal life without taking the drug and becomes very upset if it is not available.Physical dependence, when the body cannot work without a regular supply of the drug may happen with long term use. This is common with depressants and a nalgesics. Depressants slow the nervous system and relax the body. Alcohol is the most common, but other legal depressants are abused for these effects. These include barbiturates (sleeping pills), tranquilisers and solvents (glue and gases). Analgesics reduce the user’s reaction to pain, discomfort and anxiety. Opium, heroin and codeine are obtained from opium poppies.Methadone and pethidine are synthetic (chemical rather than natural) analgesics. Many analgesics have medical uses. Withdrawal symptoms, which make the user feel unwell, can happen when a regular user stops taking a drug. When a person has an overdose, he or she takes more of the drug than the body can cope with, becomes very ill and may even die (Brown and King 1990). Mechanisms of Drug Action To describe the mechanism of drug action in the brain, whenever a person uses a drug and the effect it produces is somehow pleasant, this effect gets a rewarding quality for that person.As experimental research by behavi oural psychologists has demonstrated, all behaviours that are reinforced by a reward have a tendency to be repeated and learned. Successive repetitions, besides fixing the reward-producing behaviours, also fix all previously indifferent stimuli, sensations, and situations, eventually associated with those behaviours. Seeing particular places or persons, hearing specific music, etc, for instance, triggers in drug users the craving for their preferred drug. Using Positron Emission Tomography (PET), Dr.Edythe D. London and her colleagues at the Addiction Research Centre, in Baltimore, obtained images showing that in cocaine-users, cues associated with the use of the drug sparked an increase in the metabolism of glucose in brain areas that are associated with memory and learning (lateral pre-frontal cortex, amygdala, and cerebellum). Up to now, is far from complete our knowledge about the cerebral, chemical and structural changes that underlie reward and act as reinforcers for different behaviours, including that of drug use.Nevertheless, recent researches point to a chain of reactions, involving several neurotransmitters, leading to the release of the neurotransmitter dopamine in a brain region. Compare and contrast the Physical Dependence and Positive Incentive theories of drug addiction. Drug addiction has two components: physical dependency, and psychological dependency. Physical dependency occurs when a drug has been used habitually and the body has become accustomed to its effects. The person must then continue to use the drug in order to feel normal, or its absence will trigger the symptoms of withdrawal.Psychological dependency occurs when a drug has been used habitually and the mind has become emotionally reliant of its effects, either to elicit pleasure or relieve pain, and does not feel capable of functioning without it. Its absence produces intense cravings, which are often brought on or magnified by stress. A dependent person may have either aspects o f dependency, but often has both. â€Å"Chipping† is also a term used to describe a pattern of drug use in which the user is not physically dependent and sustains ‘controlled use' of a drug.This is done by avoiding influences that reinforce dependence, such that the drug is used for relaxation and not for escape. Physical Dependency Model After repeated exposure to certain drugs, withdrawal symptoms appear if the drug is discontinued. Withdrawal symptoms are compensatory reactions that oppose the primary effects of the drug. Therefore they are the opposite of the effects of the drug. Withdrawal effects are unpleasant and reduction in these effects would therefore constitute negative reinforcement.[Negative reinforcement is the reinforcement of behaviour that terminates an aversive stimulus] Negative reinforcement could explain why addicts continue to take the drug. However some addicts will endure withdrawal symptoms (go ‘cold-turkey') in order to reduce their tol erance so that they can recommence drug intake at a lower dose which costs less to purchase. Concentrating on the role of physical withdrawal effects at the expense of other psychological factors led to the failure to recognize the addictive properties of cocaine.Cocaine does not produce physical dependency (tolerance and withdrawal symptoms) but it is more addictive than heroin. This diagram (redrawn from Julien, 1995), shows the changing pattern in the major drug used by patients admitted to drug treatment programs in New York City during the 1980s. It is also important to emphasize that reduction in withdrawal symptoms does not explain why people take drugs in the first place. Negative reinforcement may account for initial drug taking in some situations. For example, someone who is suffering from unpleasant emotions may experience a reduction in these feelings (i.e. negative reinforcement) following drug administration. However the most likely reason for drug taking involves posi tive reinforcement. Positive Reinforcement Model The reinforcing properties of a drug are thought to be reason why most people become addicted to drugs. Addictive drugs are positive reinforcers (Carlson, 2001). As you know positive reinforcement can lead to learning a new response, and the maintenance of existing behaviours. It follows that the behaviours associated with taking an addictive drug (i. e. injecting or smoking it) will increase in probability.One way of testing this claim is to examine the reinforcing properties of drugs in animals. We already know that conventional reinforcers support bar-pressing in animals, therefore if a drug maintains a response such as bar-pressing in an animal, it is a reinforcing stimulus. At one time it was believed that animals could not be made addicted to drugs, but that view is now rejected because technical developments have shown that animals will learn new behaviours that cause injection of drugs into their body. Explain how the study of reward circuits has provided a potential explanation of drug addiction.The study of reward circuits has provided a potential explanation of drug addiction. The reinforcing effects of drugs during intoxication create an environment that, if perpetuated, triggers the neuronal adaptations that result in addiction. Imaging studies in drug abusers as well as non–drug abusers have shown that drugs of abuse increase the extra-cellular concentration of drug addiction in the striatum and that these increases were associated with their reinforcing effects. The subjects who had the greatest increases in drug addiction were the ones who experienced drug effects such as â€Å"high,† â€Å"rush,† or â€Å"euphoria† most intensely.These studies also showed that the reinforcing effects appeared to be associated not only with the magnitude but also with the abruptness of the drug addiction increase. Thus, for an equivalent increase in drug addiction, the drug was experie nced as reinforcing when it was injected intravenously, which leads to fast drug uptake in the brain and presumably very fast changes in drug addiction concentration, but not when it was given orally, which leads to a slow rate of brain uptake and presumably slow increases in drug addiction concentration.The dependency of the reinforcing effects of drugs on fast and large increases in drug addiction concentration is reminiscent of the changes in drug addiction concentration induced by phasic drug addiction cell firing (fast-burst firing > 30 Hz), which also leads to fast changes in drug addiction concentration and whose function is to highlight the saliency of stimuli. This contrasts with tonic drug addiction cell firing (slow firing at frequencies around 5 Hz), which maintains base-line steady-state drug addiction levels and whose function is to set the overall responsiveness of the drug addiction system.This led us to speculate that the ability of drugs of abuse to induce changes in drug addiction concentration that mimic but exceed those produced by phasic drug addiction cell firing results in over-activation of the neuronal processes that highlight saliency, and that this is one of the relevant variables underlying their high reinforcing value. However, studies show that increases in drug addiction concentration during intoxication occur in both addicted and non-addicted subjects, so this by itself cannot explain the process of addiction.Since drug addiction requires chronic drug administration, we suggest that addiction results from the repeated perturbation of reward circuits (marked drug addiction increases followed by drug addiction decreases) and the consequent disruption of the circuits that it regulates (motivation/drive, memory/learning, and control). Indeed, imaging studies in drug-addicted subjects have consistently shown long-lasting decreases in the numbers of drug addiction D2 receptors in drug abusers compared with controls.In addition, studi es have shown that cocaine abusers also have decreased drug addiction cell activity, as evidenced by reduced drug addiction release in response to a pharmacological challenge with a stimulant drug. We postulate that the decrease in the number of drug addiction D2 receptors, coupled with the decrease in drug addiction cell activity, in the drug abusers would result in a decreased sensitivity of reward circuits to stimulation by natural reinforcers.This decreased sensitivity would lead to decreased interest in ordinary (day-to-day) environmental stimuli, possibly predisposing subjects for seeking drug stimulation as a means to temporarily activate these reward circuits. Imaging studies provide evidence of disrupted sensitivity to natural reinforcers in addiction. For example, in a study by Martin-Solch and colleagues, the meso-striatal and meso-corticolimbic circuits of opiate addicts were not activated in response to natural reinforcers, whereas they were in controls subjects.Similar ly, in a second study by the same group, DA-regulated reward centres in tobacco smokers failed to activate in response to monetary reward. Interestingly, decreased sensitivity of reward circuits to acute alcohol administration has also been documented in cocaine abusers compared with control subjects. These findings suggest an overall reduction in the sensitivity of reward circuits in drug-addicted individuals to natural reinforcers, but also possibly to drugs besides the one to which they are addicted (extracted from the Journal of Clinical Investment May 15, 2003).