Why some students cheats Essay Example | Topics and Well Written Essays - 500 words

Why some students cheats - Essay Example Similarly, students who cheat on academic work do so because they feel the pressures of such an environment, and, lacking the means to pass the grade by their own skills and knowledge alone, they depend upon an unfair advantage to help them. Because of this, the rationale behind cheating is deeply embedded in human and animal nature, and the operations of the education system. The education system does not exist to â€Å"enlighten† its students. Ideally, however, it does offer students what they will need in life, and the opportunity to seek those goals. Post-secondary education institutions market their product instead by stressing class differences and distinctions between those who have a degree and those who do not. The requirements of a typical University often make personal success contingent upon one’s ability to conform to the expectations and needs of the department. It is the expectations of the college department which move students to try their hand at cheating. They do so in an effort to avoid falling behind and potentially losing their chance to move further into the course of study they found themselves on. This fear is based on economics and personal expectations (those of the student, his parents, and faculty). Ubiquitous access to the internet is often cited as the cause of a large volume of academic dishonesty. But although the internet is a necessary cause, it is not sufficient. While the internet has made cheating a more efficient process for students, it has not made irrelevant the more fundamental reasons for students to decide to cheat. The root cause of most cheating is, as I have already identified, unrealistic expectations on the part of parents, teachers, and faculty. These individuals provide the selection pressures on the cheater and make it such that if he or she does not cheat, he or she will be selected against and not allowed to move on. This cheating is seen as â€Å"natural† precisely because it is: all

Addiction for Plastic Surgeries Essay Example for Free

Addiction for Plastic Surgeries Essay Plastic surgery is a medical field that deals with reshaping some body deformities that may have occurred due to birth defects or accidents. It is also used for other purposes such as treating diseases and beauty purposes. An example of a disease which can be treated through plastic surgery is melanoma. If plastic surgery is carried out for younger looks or beauty purposes, it is referred to as cosmetic surgery. This paper will directly address the issue of cosmetic surgery since it is what has caused plastic surgeries addiction all over the world. See more: Recruitment and selection process essay Cosmetic surgeries are never related to any medical condition and are normally done to enhance the physical appearance of an individual. Cosmetic surgery addicts are easily identifiable due to the numerous surgeries they undergo each time claiming that they are not happy with their looks. Many victims of cosmetic surgery suffer from a medical condition known as Body Dimorphic Disorder (BDD). This mental disorder has made people imagine that they look different from others and there is a need for surgery so that they can improve their looks. Discussion Cosmetic surgery is a major problem today as a number of people who are addicted to it are doing it repeatedly in order to achieve their imaginary beauty. This practice is becoming frequent and in many instances it is affecting women as they try to change and improve their physical appearances. The problem with such kind of people only exists in their mind because it is hard to view yourself as being ugly from others, it is only a perception. If you view yourself as being ugly from others, the problem will never end even if you undergo so many plastic surgeries. This perception will directly influence the level of your happiness and accepting yourself the way you are. The practices of undergoing plastic surgery repeatedly in order to feel happy and look like the ones you view as more beautiful than yourself is what doctors refer to as BDD. This condition normally affects both male and females under the age of 18 equally (Gorbis, 2003). People suffering from BDD use plastic surgery as a solution to their unending dissatisfaction with their body physical appearance (Gorbis, 2003). Almost all people who suffer from BDD seek solution to cosmetic surgery. As a surgeon, you should be able to discover someone suffering from this medical condition and recommend him/her to a psychologist. Any invention has both positive and negative sides but plastic surgery addiction would cause more harm to the body compared to the benefits associated with it. For instance, it can damage the skin and muscle tissue of an individual permanently. Another well-known harm caused by plastic surgery addiction is the permanent nerve damage. This may result to permanent loss of feeling and sensation in all the affected areas of an individual who have undergone plastic surgery repeatedly. Many individuals who undergo plastic surgery repeatedly to perfect their physical appearances in most cases end up with irreversible damage that make them look awful compared to their original appearances. Plastic surgery addiction cause more harm to the physical appearance of people with BDD instead of enhancing it. People suffering from BDD undergo plastic surgery so that they can attract attention from the public. They later regret when things go wrong. This is an indication that it should be discouraged and people suffering from BDD should be referred to a Psychiatrist or psychologist instead of a surgeon. Plastic surgery is not cost friendly at all. The operation is very expensive and its outcomes are sometimes not worth the price. What the addicted victims fail to understand is that, plastic surgery operation can only result to two things. That is, a great success or a failure. This means that, the more operations you undergo, the higher the risk of failure (Pruitt, 2009). Many individuals who are addicted to plastic surgery are attracted by what they see in the media. They watch successful surgeries of famous celebrities and think that it might as well work on. This is not usually the case and the individuals we watch on the media having successful surgeries sometimes develop problems at a later date. Plastic surgery addiction is very different from drugs and other things addiction in that it fulfills people physiological needs. Therefore, it is normally difficult for individuals who are not satisfied with their physical appearance to stop plastic surgery. This is something they are viewing in the mirror now and then. If they are not satisfied with what they see, they will definitely run to a surgeon so that the body part they feel is not well placed can be rectified. The problem with such an individual is that he/she is likely not to be satisfied with many body parts. Thus, resulting to a series of plastic surgeries so as to be satisfied with his/her physical appearance. In my opinion, I would only recommend plastic surgery to individuals who have a medical problem. I would never encourage cosmetic surgery because it is doing more harm than enhancing appearance of individuals who are undertaking it. Most people who are addicted to cosmetic surgeries perceive themselves in the wrong manner. They normally have their imaginary images on their minds which they think they can turn to after the operation. This normally does not happen and that is why they undergo so many operations before they realize they are destroying their images. Plastic surgery should only be carried out under medical conditions not for pleasure. Pictures are all over the internet showing how plastic surgery addiction has caused a number of celebrities to lose their good looks. Cosmetic surgery is not good at all because it has not worked well for people who have done it. They are suffering from negative impacts of plastic surgery addiction. It should be therefore be discouraged unless under medical conditions. Conclusion Plastic surgery is not bad if it is used for solving a medical condition. However, having a plastic surgery for beauty purposes or look young should be discouraged by all means. It should be discouraged because it might possibly lead to addiction. Physicians as well as public awareness concerning BDD should be increased to control the unnecessary plastic surgeries. Doctors should also try their best to identify troubled patients so that they can direct them to psychologist or psychiatrist who can advise them. There are other treatments other than surgeries which can help people who have problems with their physical appearance. Psychologist and psychiatrists can really assist individuals with plastic surgeries addiction. The only problem to the control of this addiction is that cosmetic and plastic surgery is so accessible and doctors have not provided a regulation on the number of surgeries an individual should undergo in a given period.

Presentation on Anti-Malaria Mosquitoes Essay -- Powerpoint Presentatio

The Malaria Protozoan parasite, of the genus Plasmodium. There are two main types of Plasmodiumthat infect humans Plasmodium Falciparum Plasmodium Vivax Transmitted by female mosquitoes Develops in mosquito gut Migrates to salivary glands Transfers to other organisms through the saliva of the mosquito. The Mosquito A mosquito is an organism of the family Culicidae. The females require a blood meal to develop eggs. The mosquito vector for malaria is the mosquito genus Anopheles. Transfers Plasmodiumthrough saliva while feeding on blood. http://www.aaenvironment.com/Pictures/Mosquito.jpg Malaria, mosquitoes, and humans http://www.clongen.com/Plasmodium%20falciparum%20life%20cycle.gif A Mosquito-borne disease Malaria is widespread, and very common in parts of the Americas, Asia, and most of Africa. No vaccine available Only medicine is preventative drugs that must be taken continuously. If infected, there is some antimalarial medication available, most notably quinine. Some other preventative measures can be taken Mosquito netting Insecticides Draining standing water So, what is this â€Å"Anti-malaria mosquito?† An anti-malaria mosquito is a mosquito that is immune to malaria. This is good because The malaria will die inside the mosquito instead of continuing its life cycle. The mosquito will not be able to transmit the malaria to other organisms. There are multiple ideas of how to create such a mosquito. Transgenic mosquito Modified symbiont The transgenic mosquito A transgenic anti-malaria mosquito is a mosquito that has had a gene inserted to make it kill the malaria while it develops in the mosquito. There have been many genes tested, including ... ... the genus Asaia stably associate with Anopheles stephensi, an Asian malarial mosquito vector." Proceedings of the National Academy of Sciences 104(2007): 9047-9051. Li, Chaoyang, Mauro Marrelli, Guiyan Yan, Marcelo Jacobs-Lorena. "Fitness of Transgenic Anopheles stephensi." Journal of Heredity 99(2008): 275-282. Favia, G. â€Å"Bacteria of the Genus Asaia: A Potential Paratransgenic Weapon Against Malaria† Transgenesis and the Management of Vector-Borne Disease 627(2008):49-59. Yoshida, S. "Bacteria expressing single-chain immunotoxin inhibit malaria parasite development in mosquitoes." Molecular and biochemical parasitology 113.1 (2001):89-96. Bibliography Ctd. Knols, B. "Transgenic mosquitoes and the fight against malaria: Managing technology push in a turbulent GMO world." The American journal of tropical medicine and hygiene 77.6, Suppl. S (2007):232-242.

Free College Essay

I personally don’t believe that college should be free. Making it free would only serve to limit the value of the education while filling colleges with students that have no business/need there. College would become nothing more than a 4 year extension of high school if it were free. As things are now, society needs about 25% of the population to have a college degree for the jobs that require one and about 30% of the population has a degree. As a result, you hear from a lot of people that believe that they wasted time getting the degree because it’s not serving them as an employment enhancer. Further, nothing is truly free. Were college free to all students, someone would still have to pay those bills. Public education is already the single largest expense of non-federal governments and a huge part of the federal expense. Increasing the scope of free public education would also significantly increase the costs involved – those costs must be borne by someone. So, you either pay for it now as tuition or you pay for it for the rest of your life in the form of taxes but either way, you’ll pay for it. And then there’s the very valid point that all people aren’t really â€Å"above average† in intellect and therefor all people aren’t capable of attending and graduating from college. Our society would like to pretend that everyone is equal in motivation and intelligence but we know that’s not really true. Don’t we? What would be the result in terms of quality if we made college completely free to anyone? Add to that problem – costs keep some people from attending. This is only bad in-as-much as it limits those individuals personally. But it’s just that barrier that makes it possible for others to attend – college seats are not an unlimited resource of which we have plenty. There are only so many colleges with so many seats and more people would like to have those seats than can. If we removed the cost barrier then the competition for seats would be even greater and we’d still not have solved the problem of universal higher education. We’d need to have as many colleges as we have high schools to truly solve that problem. Then we’d need as many professors to teach in them in. Just a few of the arguments against your position that you might want to prepare to counter in your essay. There are many people that believe the compulsory secondary school education movement (‘create 100% HS graduates†) was a mistake too. While being well educated is very good at the individual level – society still needs people to do jobs that those who keep gaining more education simply don’t want to do.

Mental Workload Assessment

We all feel stressed out and strained when we have work to do. Not only that, we experience situations like this even if we are just studying. More often, we feel pressured just by thinking the amount of exams to be prepared for, or for that next project that is necessary for a good promotion in the company. Mental workload is the right term for the stress and strain we experience, especially with regards to studying and working.   The Hanover College defines mental workload as â€Å"the feeling of mental effort or the level of use of the human operators limited resources† (n.d.).   In short, mental workload is a demand placed upon humans (Xiaoli, n.d.). When there is too much mental workload, it might lead to errors. Preventing this makes mental workload important to be understood. However, due to the many factors that must be considered in discussing mental workload, defining it becomes difficult. Mental workload is important in driving and aviation and design. In fact, most of the studies conducted about mental workload were about driving and aviation and task demands. This is perhaps due to the fact that a driver is required to do not just one but many tasks. Moreover, even though a driver is experienced, accidents still occur. De Waard (1996) conducted a study on mental workload among drivers. He said that driving a car looks like a pretty simple task for everyone. Driving schools provide comprehensive lessons and manuals on how to drive safely. But no matter how good a driver can be, accidents cannot be avoided. Moreover, these accidents are attributed to human failure. Human failure is still increased due to several factors. First is the increasing number of vehicles on the road. There is a demand on the human information processing system, and also increase in the likelihood of vehicles colliding. Second, people drive well into old age. However, older people tend to suffer from problems in terms of divided attention performance. It all started with the car radio, and then car phones and other technological devices. The driver must divide his attention to all these systems besides controlling the vehicle. Lastly, those drivers in a diminished state may endanger him. Most of the time, drivers set out at night for the longer journeys to avoid traffic. Driving at night can cause him sleepiness and fatigue. Aside from this, the driver can also be intoxicated (de Waard, 1996). Xiaoli (n.d.) presented the factors which affect driver workload, including the following: fatigue, monotony, sedative drugs and alcohol. Environmental factors also affect drivers, such as traffic demands, automation and road environment demands. There are different techniques in assessing mental workload, including the following: performance measures, physiological measures, and subjective task measures (or self-report measures) (Luximon & Goonetilleke, 2001). Primary and secondary task measures comprise the performance, or system output measures. An overview of each assessment technique will be discussed in the context of traffic research (driving or aviation). Performance Measures In Xiaoli’s (n.d.) slide presentation, he said that the measures usually belonging to this category are speed of performance, number of errors made and reaction time measures. Outside the laboratory, these become task-specific. De Waard (1996) said that most of primary-task measures include speed or accuracy measures. Aside from this, De Waard (1996) explained that primary-task performance establishes the efficiency of man-machine interaction. Not just the primary-task performance but also other workload measures must work together so that valid conclusions can be drawn about man-machine interaction. There are several approaches in the measurement of performance measures. First is the analytical approach (Meshkati, Hancock, Rahimi and Dawes, 1995). According to Welford (1978, cited in Meshkati, Hancock, Rahimi and Dawes, 1995), the analytical approach considers the detail at the actual performance of the task that will be assessed. Not only the overall achievement is examined but also the manner in which it is achieved. Another assessment technique is the synthetic methods. These start with a task analysis of the system. Task analytic procedures are then used to identify the specific performance demands placed on the operator. The third approach is the multiple measurement of primary task performance. This approach is very useful when individual measures of primary task performance do not show enough sensitivity to operator workload. On the other hand, Xiaoli (n.d.) indicated that secondary-task performance are about factors such as time estimation or time-interval production and memory-search tasks. The assumption associated with secondary task measure says that an upper limit exists on the ability of a human operator to gather and process information (Meshkati, Hancock, Rahimi & Dawes, 1995). The way to measure secondary-task performance is through another task included to the primary one. De Waard (1996) mentioned about the multiple-resource theory. The theory says that â€Å"the largest sensitivity in secondary-task measures can be achieved if the overlap in resources is high† (De Waard, 1996). According to Hancock, Vercruyssen and Rodenburg (1992), a person must have the ability to synchronize their actions with the dynamics of differing environmental demands so that he can survive and prosper in uncertain conditions. This means that the person must have some degree of autonomy with respect to space and time. However, secondary-task measures have disadvantages to consider. According to De Waard (1996), time sharing is not very efficient if the same resources are utilized. Moreover, additional instrumentation is required in secondary-task measures. Not only that, but there is lack of operator acceptance. There are also possible compromises to system safety. Subjective Task Measures There is much talk about the self-report measures, which is also called subjective measures. In fact, for De Waard (1996), self-report measures are advantageous because they can better show the real meaning of mental workload. These measures’ subjectivity is what makes self-report measures strong. Muckler and Seven (1992, as cited in De Waard, 1996) explained that self-report measures are strong because the awareness of the operator about the increasing effort used must give subjective measures an important role to play. Moreover, performance and effort are incorporated in self-report measures. Additionally, individual differences, operator state and attitude are also considered. Xiaoli (n.d.) said that the primary advantages of subjective task measures are high face validity, ease of application and low costs. However, there are also limitations in these measures. First is that there might be confusion of mental and physical load in rating. There might also be an exhibition of the operator’s inability to differentiate between external demands and actual effort or workload experienced. Second, limitations can be seen in the operator’s ability to introspect and rate expenditure correctly. Hancock, Brill, Mouloua and Gilson (2002) added that another disadvantage of self-report measures is that they cannot be used for online workload assessment. Physiological Measures According to De Waard (1996), physiological measures showed sensitivity to global arousal or activation level and in some stages in information processing. One advantage of this is that physiological responses do not need an obvious response by the operator. Additionally, most cognitive tasks do not need overt behavior. Moreover, some of the measures can be collected continuously. Kramer (1991, cited in De Waard, 1996) showed some of the disadvantages of these measures. First is that there must be specialized equipment and technical expertise to be able to utilize these measures. Second is the presence of signal-to-noise ratios. Kramer furthered that in operator-system performance, the operator’s physiology is not directly involved, unlike in primary-task performance. Other physiological measures involved in driving are pupil diameter, endogenous eye blinks, blood pressure, respiration, electrodermal activity, hormone levels, event related potentials, and electromyogram. De Waard (1996) furthered that not all measures are sensitive to workload when it comes to performance. There are instances when dissociation between these measures of different categories was reported. He said that dissociation occurs between measures when they do not correspond to changes in the workload, or if there is an increase in one measure and a decrease in another. Performance is thus affected by the amount of resources invested and the demands on working memory. Hancock, Brill, Mouloua and Gilson (2002) said that although physiological measures present global assessments of workload, they do little to balance the demands of tasks on sensory systems. In addition, physiological measures provide little or no information about what sensory systems are most taxed. To measure mental workload, two groups must be considered (Gopher & Donchin, 1986, cited in De Waard, 1996). Self-report measures, physiological measures and performance measures are included in the first group. This group supposes that it is probable to achieve a global measure of mental workload. The second group includes secondary-task measures and some of the physiological measures. This group is concerned about those diagnostic procedures and has something to do with the theories of multiple resources. References De Waard, Dick. (1996). The measurement of drivers’ mental workload. The Netherlands: The Traffic Research Center VSC. Hancock, P.A., Brill, J.C., Mouloua, M., & Gilson, R.D. (2002). M-SWAP: On-line workload assessment in aviation. Paper presented at the 12th International Symposium on Aviation Psychology. Dayton, OH. Hancock, P.A., Vercruyssen, M., & Rodenburg, G.J. (1992). The effect of gender and time-of-day on time perception and mental workload. Current Psychology: Research and Review,. 11, 203-225. Hanover College. (n.d.). Mental Workload. Retrieved October 27, 2007 from http://psych.hanover.edu/classes/hfnotes3/tsld022.html Luximon, A. & Goonetilleke, R. (2001). Simplified subjective workload assessment technique. Ergonometrics, 44, 229-243. Meshkati, N., Hancock, P.A., Rahimi, M., & Dawes, S.M. (1995). Techniques of mental workload assessment. In J. Wilson and E.N. Corlett, (Eds.). Evaluation of human work: A practical ergonomics methodology. (Second Edition), London: Taylor and Francis. Xiaoli, Yi. (n.d.). Measurements of mental workload. [Slide presentation]. Available on http://www.slideshare.net/ESS/measurement-of-mental-workload/            

Airport Body Scanners and Personal Privacy Essays

Airport Body Scanners and Personal Privacy Essays Airport Body Scanners and Personal Privacy Essay Airport Body Scanners and Personal Privacy Essay SecurityAdministrationAirport Body Scanners and Personal Privacy Believe it or not, there was a time when passengers showed up an hour before their flights and walked directly to their assigned gates without taking off their shoes at a security screening station or throwing away their bottles of water. There was even a time when friends and family met passengers at the gate and watch their flights take off or land without having a ticket or identification†¦and that was only ten years ago. Air travel safety precautions changed dramatically after the September 11, 2001 terrorist attacks that targeted passenger planes in the United States and killed well over 1,000 people. Precautions continue to evolve as new threats are detected and passengers are now concerned about where to draw the line with invasion of privacy versus national security, particularly with the introduction of the body scanners at security checkpoints. Flight passengers must accept the use of body scanners to ensure safe air travel for all. In 2007, the Transportation Security Administration (TSA) began distributing body scanners to use at security checkpoints in airports. There was an instant outrage when people were told that the scanners produced images of passengers without clothing. As of September 2010, there were 200 body scanners at 50 airports in the United States with hundreds more to come (Stellin 2010). Disgruntled passengers have vehemently protested the invasion of privacy resulting from the body scan images. Passengers are equally angry with the alternative to the body scan: an intrusive, full-body pat-down that is more intimate than pat-downs of the past. According to the American Civil Liberties Union, â€Å"The TSA has recently changed its guidelines and these pat-downs are now much more invasive. Screeners are now authorized to use the front of their hands and to touch areas around breasts and groins. † (2010). Women and men both liken the new pat-down regulations to sexual molestation and claim that it is not an acceptable option over having a naked body image scanned and viewed by a TSA agent. Holiday travelers were recently advised by independent groups to protest the body scanners’ invasion of privacy by insisting on having the pat-down alternative in public view so fellow travelers could see the invasive nature of the new procedures. There are also concerns over the safety of the body scanners. There are currently two types of scanners: millimeter wave body scanners and backscatter scanners. The millimeter wave scanners use electromagnetic waves to create images, while the backscatter scanners emit low-levels of radiation that reflects off the skin to create the naked body image. Frank 2010). Passengers are demanding to know the long-term effects of the radiation exposure required to capture the body images when using the backscatter scanners. Pilots are also up in arms over the new scanners and claim that the small amounts of radiation exposure increase the already high risk level of cancer seen in airline pilots. Knox claims that the U. S. Airline Pilots Associ ation and the Allied Pilots Association are recommending that pilots refuse the body scanners and request a pat-down (2010). Passengers are arguing that the privacy violations and increased radiation exposure that the body scanners are creating are not even relevant in the fight against terrorism, as most of the current security measures are reactionary. For example, in 2002, Richard Reid attempted to blow up a passenger plane by using a bomb in his shoe. Ever since then, passengers flying out of domestic airports are required to remove their shoes for scanning before clearing security. Security has not uncovered another shoe bombing since the incident. Another example is the 2006 terror plot discovered by British authorities. The plot involved a man who planned to detonate a bomb with liquid explosives and a MP3 player. In response to this threat, passengers were banned from bringing liquids or gels onboard, with the exception of those purchased in the terminal after clearing security†¦bad news for travelers who want to bring a thermos of coffee from home, but good news for the airport vendors. In 2009, a man on a flight from the Netherlands to Detroit attempted to blow up a plane with explosives in his underwear. Although the body scanners were in the United States at the time, they were not in the Netherlands. Passengers argue that no matter how many security measures are put in place, terrorists will find a new and innovative way to cause destruction. They claim that the only guarantee the body scanners can make is violation of privacy for innocent people. Privacy issues often become a heated debate in a country like the United States of America, which was founded on the basic principle of freedom. Passengers are outraged that officials are viewing nude images of their bodies. They are rebelling against intrusive pat-downs and demanding better solutions. The TSA takes all of these concerns under consideration and has made admirable efforts to ensure privacy, as well as to clarify points used in arguments against the new screenings. For example, the TSA has established strict guidelines regarding the images received by the body scanners. Images of women are only viewed by female agents and images of men are only viewed by male agents. The agents viewing the images are in a separate, secure room and never see the passengers they are viewing on screen. According to TSA’s privacy policy, â€Å"The two officers communicate via wireless headset. Once the remotely located officer determines threat items are not present, that officer communicates wirelessly to the officer assisting the passenger. The passenger may then continue through the security process. † (2010). The images are not stored; they are deleted after being viewed. â€Å"Advanced imaging technology cannot store, print, transmit or save the image, and the image is automatically deleted from the system after it is cleared by the remotely located security officer. Officers evaluating images are not permitted to take cameras, cell phones or photo-enabled devices into the resolution room. † (Privacy 2010). Also, in many cases, the scanners have a special feature that blurs faces so distinguishing facial characteristics are not seen. â€Å"To further protect passenger privacy, millimeter wave technology blurs all facial features and backscatter technology has an algorithm applied to the entire image,† (Privacy 2010). Privacy measures have also been taken with the pat-downs. Passengers have the right to request a private area for the pat-downs, out of view from other passengers. The TSA Pat-Down procedure states, â€Å"You have the right to request the pat-down be conducted in a private room and you have the right to have the pat-down witnessed by a person of your choice. All pat-downs are only conducted by same-gender officers. The officer will explain the pat-down process before and during the pat-down. † (2010). While officials are unable to do anything about the intrusive nature of the pat-down, the TSA says, â€Å"Pat-downs are one important tool to help TSA detect hidden and dangerous items such as explosives. Passengers should continue to expect an unpredictable mix of security layers that include explosives trace detection, advanced imaging technology, canine teams, among others. (TSA Statement 2010). According to government officials and researchers, the concerns about increased radiation from the body scanners are unfounded. Consumer Health News quotes physics professor Peter Rez as saying, â€Å"The probability of getting a fatal cancer [from the body scanner] is about one in 30 million, which puts it lower than the probability of being killed by being struck by lightning in any year in the United States, which is about one in 5 million. (Reinberg 2010). While passengers are exposed to very small amounts of radiation from the backscatter body scanner, the millimeter wave scanner’s electromagnetic waves are harmless. Frank states, â€Å"Millimeter-wave machines are entirely safe. Backscatter machines, which emit low levels of radiation, have been studied and declared safe by groups including the Food and Drug Administration, the American College of Radiology and the Johns Hopkins University Applied Physics Laboratory. The FDA says backscatter machines emit less radiation in each scan than a passenger receives during two minutes of a flight. † (2010). The biggest criticism of security measures, including the body scanners, is that they are reactionary methods of keeping flights safe. That statement is true; however, it does not invalidate the fact that the measures have successfully kept domestic flights safe since they were implemented. There hasn’t been another instance of a shoe bomber because terrorists know they will be detected through security. There hasn’t been a liquid explosive or explosives in underwear on domestic flights for the same reason. Without a doubt, the security measures slow travel down, and offend passengers- but they are done in the name of safety and they are the best options currently available for safe travel. Reactionary methods are necessary to prevent the same tragedy from happening over and over again. It is crucial to learn from past weaknesses and build stronger security protocols based on previous attack methods. The new body scanners in airports across the country upset many travelers. It is true that the scanners do produce graphic images; however, there are TSA precautions in place to ensure the utmost level of privacy and respect possible for travelers while protecting the safety of everyone traveling on passenger planes. Health concerns over the scanners are not merited and numerous studies have found that the levels of radiation emitted are negligible. TSA offers a body pat-down for those who remain unconvinced of the scanners’ safety or are unwilling to have an image taken. While the pat-downs are intrusive, like the scanners, they are necessary to ensure the safety of everyone. The reality of the world is that there is danger. There are people all over the world and within the United States who want to do harm to others. An invasion of privacy is preferable over death, particularly when the body scans are conducted with the highest amount of discretion possible while still being effective. Passengers must not think of the new security measures as insulting and degrading; they are, in fact, an insurance policy that makes air travel one step closer to being safe. Reference List Frank, T. (2010, November 24). Answers to questions on new measure. USA Today. Knox, R. (2010). Protests mount over safety and privacy of airport scanners. National Public Radio. Retrieved from npr. org Privacy. (2010). Transportation Security Administration. Retrieved from www. tsa. org. Reinberg, S. (2010, November 23). Airport body scanners safe, experts say. Consumer health news. Stellin, S. (2010, September 12). Are scanners worth the risk? New York Times. TSA pat-down search abuse. (2010). American Civil Liberties Union. Retrieved from aclu. org/technology-and-liberty/tsa-pat-down-search-abuse TSA statement. (2010). Transportation Security Administration. Retrieved from www. tsa. org.

Free Essays on Time Capsule

We are a society that is on the go, we try to do more in less time, and we want it â€Å"now.† The 21st century has been labeled by some as the century of â€Å"Instant Gratification.† As a result, technology has developed by leaps and bounds, to satisfy our growing need for wanting what we want, when we want it. If I were asked to name three items to place in a time capsule that would best represent the 21st century I would select a microwave, a computer, and a VCR (Video Cassette Recorder). I feel a microwave best represents the 21st century because it fits perfectly into our â€Å"on the go† lifestyles. It is easy to use, takes less time, and is safer than conventional cooking. With a few basic rules and directions, even our children can use a microwave. All it takes is a couple of minutes, and a few taps on the keys, and then anyone can have a hot meal. The microwave has become the new kitchen marvel. I would also include a computer because a computer gives us the opportunity to do more in less time. For example, computers can figure out simple and complex math problems, quickly and effectively. Computers can also point out our mistakes in writing, so that we can make corrections quicker and with less mess. Our children enjoy learning through games available in learning software. This frees up adults’ time to accomplish other tasks, and the children seem to learn quicker when they are enjoying themselves. Without computers we would not be able to tap into the wealth of knowledge available on the Internet. We enjoy sharing our knowledge with one another, and we can communicate in a flash with the use of instant messaging and e-mail. Lastly, I would include a VCR because humans love stories and the VCR reinforces our desires of â€Å"Instant Gratification.† The human race has always been storytellers, whether the stories are real, make believe, new or old. In the 21st Century, we have many ways to convey our stor... Free Essays on Time Capsule Free Essays on Time Capsule We are a society that is on the go, we try to do more in less time, and we want it â€Å"now.† The 21st century has been labeled by some as the century of â€Å"Instant Gratification.† As a result, technology has developed by leaps and bounds, to satisfy our growing need for wanting what we want, when we want it. If I were asked to name three items to place in a time capsule that would best represent the 21st century I would select a microwave, a computer, and a VCR (Video Cassette Recorder). I feel a microwave best represents the 21st century because it fits perfectly into our â€Å"on the go† lifestyles. It is easy to use, takes less time, and is safer than conventional cooking. With a few basic rules and directions, even our children can use a microwave. All it takes is a couple of minutes, and a few taps on the keys, and then anyone can have a hot meal. The microwave has become the new kitchen marvel. I would also include a computer because a computer gives us the opportunity to do more in less time. For example, computers can figure out simple and complex math problems, quickly and effectively. Computers can also point out our mistakes in writing, so that we can make corrections quicker and with less mess. Our children enjoy learning through games available in learning software. This frees up adults’ time to accomplish other tasks, and the children seem to learn quicker when they are enjoying themselves. Without computers we would not be able to tap into the wealth of knowledge available on the Internet. We enjoy sharing our knowledge with one another, and we can communicate in a flash with the use of instant messaging and e-mail. Lastly, I would include a VCR because humans love stories and the VCR reinforces our desires of â€Å"Instant Gratification.† The human race has always been storytellers, whether the stories are real, make believe, new or old. In the 21st Century, we have many ways to convey our stor...

Special Greetings in English for ESL Learners

Special Greetings in English for ESL Learners It is common to use a special greeting used just for that occasion on special days, holidays and other special occasions. Here are some of the most common: Birthdays Happy birthday!Best wishes/Good luck on your thirtieth (age - use an ordinal number) birthday!Many happy returns! Wedding/Anniversary Congratulations!Best wishes / good luck on your tenth (number - use an ordinal number) anniversary!Heres to many more happy years together (used when making a toast) Special Holidays Merry Christmas!Happy New Year/Easter/Hanukkah/Ramadan etc.All the best for a happy New Year/Easter/Hanukkah/Ramadan etc. When making special greetings to children on their birthday and at Christmas, it is also common to ask them what they received: Merry Christmas! What did you get from Santa Claus?Happy Birthday! What did your Daddy get for you? Special Occasions Congratulations on your promotion!All the best for your ...Im so proud of you! More Social Language Key Phrases IntroductionsGreetingsSpeaking to StrangersTraveling phrases

MSc Subsea Engineering and Management Personal Statement

MSc Subsea Engineering and Management - Personal Statement Example My discipline is Civil Engineering and with appreciable grades (Grade standing 2:2). I intend to continue my education in engineering even after my B Engineering. For that purpose, I considered many fields for further education, but seeing the plethora of opportunities and better professional prospect in the field, I decided to pursue further education in Subsea Engineering. Subsea engineering is an emerging field in the 21st century, when demands for energy resources and the concerns for environmental issues have been of the top of the list. As subsea engineering deals with both of the realms, it has seen a substantial surge in the sector. The realm of subsea and subsequently its application is growing day by day. Humans’ curiosity of exploration as well as the thirst for energy resources, both have led to intensive exploration of resources of the sea globally. Booming search for Oil and Gas reservoirs under seabed has open new opportunities for Subsea engineering. Such a rapid expansion in offshore oil and gas exploration has emulated robust demand of engineers specialized in subsea operations. However, there are other sectors also, where Subsea Engineering is applied. Some of these sectors are marine biology, undersea-geology, undersea mining, and offshore wind power industries. Subsea Engineering today is mainly focused on oil and gas sector. With the passage of time, many big names of international repute are now turning their focus on energy reserves in deep beds of the sea. Similarly, research explorations on the environment and geology have also opened new avenues for the discipline of Subsea Engineering. Its high market demand and future prospects have garnered my attention. As an Engineer, I am truly fascinated about the work and life of a subsea engineer that is full of adventures and thrills peculiar to the field of engineering (Harris, 2011). As I was intended to continue my

Enzymatic Analysis of Yeast Alcohol Dehydrogenase Lab Report

Enzymatic Analysis of Yeast Alcohol Dehydrogenase - Lab Report Example A similar experimental design was used to analyze the effect of prior presence of varying concentrations of ethanol in the reaction mixture to evaluate its effect on the recovery of MTT formazan, thereby indicating the effect of alcohol on aldehyde dehydrogenase activity. Ethanol presence enhanced the alcohol dehydrogenase activity at all concentrations. A Vmax value of 0.0224Â µmol/min and Km value of 1.171 M were obtained. Alcohol dehydrogenase is the main enzyme involved in fermentation of carbohydrates for the commercial and industrial production of alcohol. It is derived from yeast, which is added to carbohydrates to induce anaerobic fermentation. Chemically, Alcohol dehydrogenase is a homotetrameric enzyme of approximately 150 kDA size which catalyses the reversible oxidation of alcohols. It is responsible for converting ethanal to ethanol and other alcohols during fermentation. Fermentation is the process in which glucose, a major constituent of all carbohydrates, undergoes glycolysis under anaerobic conditions with the resultant production of alcohol. The reaction is characterized by the regeneration of oxidized nicotinamide dinucleotide (NAD+), which is essential for maintenance of glycolysis under anaerobic conditions with resultant seizure of mitochondrial respiration. Estimation of NAD+ spectrophotometrically can therefore serve as an important method of estimating and monitoring the oxidati on of ethanol. Two experiments were designed for the purpose. In the first experiment, the optimal conditions necessary for the catalytic activity of yeast dehydrogenase (yADH) were studied by first preparing yeast extract under identical conditions and then subjecting these extracts to variable factors like dilution, time, pH and temperature. The production of NADH was measured indirectly by following the reduction of 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide

Kraft Essay Example | Topics and Well Written Essays - 500 words

Kraft - Essay Example Kraft Foods Inc. has a reputable financial history as depicted from the previous year’s revenues. For instance, in the year 2013 ending, the company registered net revenue of $4595 million and in 2012 ending it reported net revenue of $4492 million (Kraft Foods Inc., 1). The firm’s key profitability drivers include the diverse category of products, a superior brand assortment, significant coverage in the Northern America, a wide-spread reputation for the most quality products in the food industry and a strong foundation in innovation and use of the latest technology in its operations, a deep knowledge about consumer’s interests, a long-lasting relationship with its major retailers and suppliers and an experienced team of managers who are solely driven by the firm’s core goals or rather aims in achieving the best (Kraft Foods Inc., 1). The substitute products in this industry are hot drinks such as tea, all the beverages and beverages that have caffeine, Cola. Thus, all the firms in this industry are good producers of the above mentioned products. This is due to the high number of nations which are chief coffee exporters, alternative products as a result of different types of coffee beans and insufficient money supply due to the impossible forward integration for suppliers. Thus, the farmers can combine forces but the wealthier will always influence the market. This industry or rather market has an oligopoly structure whereby there are a few globe competitors such as Nestle, Kraft Foods and Sara Lee. In addition, the industry has a relatively smaller regional roasters and intense competition from the final products of these firms. This is due to product differentiation that results to a number of flavors in coffee

Comparison of IFRS and US GAAP Essay Example | Topics and Well Written Essays - 2500 words

Comparison of IFRS and US GAAP - Essay Example A financial statement must provide details with regard to financial position, changes in position and operations of an enterprise which may be useful for decision making. International Accounting Standards Board is development of International Accounting Standards Committee (IASC) created in 1973 with the objective of developing the uniform standards of accounting. IASB and US Financial Accounting Standards Board (FASB) congregated the IFRS and US GAAP in 2002 as part of the Norwalk agreement making their existing financial reporting standards compatible and practicable and coordinating their future work programme to ensure compatibility. The IASB provided two accounting standards for financial reporting frame works like International Financial Reporting Standards (IFRS) developed by The International Accounting Standards Board (IASB) and Generally Accepted Accounting Principles (US GAAP). The US GAAP was acknowledged extensively as the international set of standards to make certain best quality financial statements. This standard was mostly used in the US and also elsewhere, but with the entry of IFRS a debate on the virtual class of both authoritie s has taken place. GAAP is exceptionally comprehensive on what is acceptable and unacceptable. IFRS is used by more than hundred countries as their standard set of guidelines and principles. Still more countries, like Canada and India are projecting to follow IFRS from 2011. This paper is intended for providing some explorative information on the IFRS / US GAAP and also some demarcation and comparison of the two standards of financial reporting. More specifically, the purpose of the current study is to investigate the properties of IFRS versus US GAAP standards of accounting using the accounts of National Grid Plc that is listed both in EU and US Stock Exchange. And most importantly, the paper identifies the difference between the rules and principles of two accounting standards through the accounts of National Grid Plc and its usefulness to various stakeholders of the organization. IFRS and US GAAP - Significant differences in National Grid Plc National Grid is an energy production organization which owns and operates the electricity transmission system in England and US. National Grid distributes gas to 11 million homes and businesses in UK. The company is also engaged in business of wireless infrastructure along with other businesses like National Grid Metering, Onstream, National Grid Grain, property, etc. The main areas of operation of the company are UK and US which was created by the restructuring of UK gas industry in 1986 and electricity industry in 1990 and entered the US market in the year 2000. (www.nationalgrid.com) According to annual report for the year 2005/06, it is revealed that the group has achieved 25% increase in the revenue from 7382m to 9193m. And according to the same reports, operating profits have also increased from 2142m to 2439m (2005/06) which is 14% higher. National Grid has also entered into acquisition and merger with some companies like Keyspan Corporation. The company with its base in US and UK, the countries which adopt two different standards of accounting principles, has to prepare accounts conforming to the rules and regulations of that particular nation. However,

Analytic and critical thinking essay Example | Topics and Well Written Essays - 750 words

Analytic and critical thinking - Essay Example Nevertheless, through the enlightenment he acquired through the teachings of Buddha, he was able to acquire wisdom and understanding and therefore was able to live an exemplary life. This paper then looks deeper into the perceptions of Thich Nhat Hanh and why he claims that death is non-existent, reflecting Buddhist philosophies. In his journey to understanding what death is all about, Hanh experienced illumination during one of his meditative states. He saw a japonica bush that blossomed one winter when warmer days came quite early. However, when winter conditions took its natural course, the blossoms fell to the ground. When the weather got warm again, another set of flowers blossomed and the wonderment whether those were the same blossoms that fell to the ground or whether they are different was asked by the hermit. The answer of the blossoms gave a new understanding to the seeker of truth and there begun his freedom from grief regarding death. He observes that the blossoms  "were not the same and not different† (Hanh). When the day became warm during winter, it was a condition that allowed the flowers to blossom and they manifested themselves. However, when the conditions changed, bringing the cold gloomy days which are not a convenient for the flowers to thrive, they fell from the bush instead but showed themselves again when the circumstances permitted their existence. Nevertheless, that is not considered the dying of the flowers. This perfectly exemplifies the belief of the Buddha that â€Å"when conditions are sufficient, something manifests and we say it exists† (8). The blossoming and falling of the flowers are considered in Buddhism, as a condition wherein they have hidden themselves because the weather condition is not well-suited or convenient for them. Another insightful example the Hanh presents in trying to explain his perspective is that, death only brings a person to another level of being. To expound further, he likens peopl e to radio waves which, â€Å"without a radio, we do not manifest† (12). This means that there is a tangible and an intangible part of us. The tangible part, which is the body, may die and eventually decay. However, there is an intangible part which becomes ever present to his loved ones. A loved one whose body has gone is not actually gone forever but is always present evidenced by the ground their feet once trod, an abode or even a person’s very self. Buddhists believe just because one is not physically seen does not mean he is not present. Rather, it is only the body wherein a person once manifested himself that is gone. Coming from a family whose parents are divorced, this notion is a great help for my coping. Although I live with my mother only, I do not see myself as without my father. Distance is not what defines his existence but it is who he is in me. I am his son, his blood runs through my veins and somehow, I know that he is there with me even if I do not se e him. Similarly, when death comes, it only separates me from my loved ones physically but their presence is always felt even though I do not see them. Death and grief are difficult to overcome. Some people even violate their own lives because they are not able to cope with the emotions brought about by this incident.

CAN COMPASSION BE TAUGHT An exploration of the concept of teaching Literature review

CAN COMPASSION BE TAUGHT An exploration of the concept of teaching compassion to nursing staff within the field of dementia - Literature review Example In this regard, a framework was developed using the guide for critiquing quantitative research suggested by Coughlan, Cronin and Ryan (2007) and the guide for critiquing qualitative research suggested by Ryan, Coughlan and Cronin (2007). Ten journal articles were selected using an exclusion and inclusion criteria based on relevance, appropriateness and the most recent research on the subject under investigation. A Fishbone analysis was conducted to determine the challenges for implementing and using compassion in the delivery of care to patients with dementia for determining the extent to which compassion can be taught as revealed in the literature. Results: The results of the study indicate that nursing staff delivering care to dementia patients and dealing with families and carers are at an increased risk of compassion fatigue. The results indicate that compassion can be taught directly and indirectly provided the welfare and wellbeing of nurses are safeguarded and promoted. Discus sion: Implications for practice and directions for further research are discussed. The limitations and strengths of the research are also discussed. Conclusion: It is concluded that in order to successfully teach and maintain compassion in the context of nursing staff in the field of dementia, three approaches have to be taken. ... dementia are at an increased risk of suffering compassion fatigue, efforts must be made to safeguard the welfare and well-being of nursing staff to ensure that they are retained and nurses do not become over-burdened with an imbalance in demand and supply. Table of Contents Abstract 2 Chapter One: Introduction and Background 4 1.1.Introduction 4 1.2.Background 5 1.3.Aim of the Study 7 1.3.1.Objectives of the Study 7 1.3. Research Methods 8 Chapter Two: A Critical Review of Literature 11 2.1. Compassion: Definition and Concepts 12 2.2. The Role of Compassion in the Care of Dementia Patients 15 2.3. Teaching Compassion to Nursing Staff in the Field of Dementia 20 Chapter Three: Findings and Conclusion 28 3.1. Findings and Conclusion 29 3.2. Implications for Practice 34 3.3. Suggestions for Further Research 36 3.4. Limitations of the Study 36 3.5. Strengths of the Study 37 Bibliography 37 Chapter One: Introduction and Background 1.1. Introduction Compassion is described as a significant quality in nursing that has an impact on the care delivered to patients (Kret, 2011). With respect to patients suffering from dementia, care science theorises that core competence and skills among nursing staff includes patience, consideration and compassion (Rundqvist & Severinsson, 1999). However, studies have shown that caregivers administering care to patients suffering from dementia are at a heightened risk of suffering from ‘compassion fatigue† (Day & Anderson, 2011, p. 2). Compassion fatigue is associated with a lack of nursing staff juxtaposed against increasing patient demands and the physical and mental burdens nursing staff confront in meeting increased patient care demands (Bush, 2009). Effective nursing care for patients with dementia is accomplished by the ability to look

Analytic and critical thinking essay Example | Topics and Well Written Essays - 750 words

Analytic and critical thinking - Essay Example Nevertheless, through the enlightenment he acquired through the teachings of Buddha, he was able to acquire wisdom and understanding and therefore was able to live an exemplary life. This paper then looks deeper into the perceptions of Thich Nhat Hanh and why he claims that death is non-existent, reflecting Buddhist philosophies. In his journey to understanding what death is all about, Hanh experienced illumination during one of his meditative states. He saw a japonica bush that blossomed one winter when warmer days came quite early. However, when winter conditions took its natural course, the blossoms fell to the ground. When the weather got warm again, another set of flowers blossomed and the wonderment whether those were the same blossoms that fell to the ground or whether they are different was asked by the hermit. The answer of the blossoms gave a new understanding to the seeker of truth and there begun his freedom from grief regarding death. He observes that the blossoms  "were not the same and not different† (Hanh). When the day became warm during winter, it was a condition that allowed the flowers to blossom and they manifested themselves. However, when the conditions changed, bringing the cold gloomy days which are not a convenient for the flowers to thrive, they fell from the bush instead but showed themselves again when the circumstances permitted their existence. Nevertheless, that is not considered the dying of the flowers. This perfectly exemplifies the belief of the Buddha that â€Å"when conditions are sufficient, something manifests and we say it exists† (8). The blossoming and falling of the flowers are considered in Buddhism, as a condition wherein they have hidden themselves because the weather condition is not well-suited or convenient for them. Another insightful example the Hanh presents in trying to explain his perspective is that, death only brings a person to another level of being. To expound further, he likens peopl e to radio waves which, â€Å"without a radio, we do not manifest† (12). This means that there is a tangible and an intangible part of us. The tangible part, which is the body, may die and eventually decay. However, there is an intangible part which becomes ever present to his loved ones. A loved one whose body has gone is not actually gone forever but is always present evidenced by the ground their feet once trod, an abode or even a person’s very self. Buddhists believe just because one is not physically seen does not mean he is not present. Rather, it is only the body wherein a person once manifested himself that is gone. Coming from a family whose parents are divorced, this notion is a great help for my coping. Although I live with my mother only, I do not see myself as without my father. Distance is not what defines his existence but it is who he is in me. I am his son, his blood runs through my veins and somehow, I know that he is there with me even if I do not se e him. Similarly, when death comes, it only separates me from my loved ones physically but their presence is always felt even though I do not see them. Death and grief are difficult to overcome. Some people even violate their own lives because they are not able to cope with the emotions brought about by this incident.

Influence of the development of low carbon infrastructure in future Essay - 1

Influence of the development of low carbon infrastructure in future - Essay Example s carbon emissions would mean that certain tradeoffs must be made between meeting the societal needs the way they were traditionally met, and achieving the new objective. In this respect, the Civil engineering profession has a role to play in developing structures that will be productive at the same rate as the traditional and current structures, may it be in terms of energy, safety or economic production, but which reduces the carbon emission to the lowest level possible. Carbon emission is an occurrence that is associated with every stage of the civil engineers project development work, starting from the design face, all the way to the construction, usage, maintenance and the dismantling of the infrastructure (ICE, 2011:7). Thus, the role of the civil engineers in the development of low carbon infrastructure must start right from the design face, until the structure is completed and put in use. Thus, these are the several ways through which the civil engineers can influence the dev elopment of low carbon infrastructure: The application of more carbon intensive technology during the construction face is one of the ways through which the civil engineers can contribute to the reduction of carbon emissions by the structure in its lifetime. This is because; the use of more carbon intensive means that there will be significantly reduced usage of carbon during the phase of usage of the infrastructure that has been developed (ICE, 2011:3). Therefore, considering the fact that the time span utilized in the development of an infrastructure is too short compared to the life time use of the infrastructure, it follows that the use of more carbon intensive during construction will help to reduce the overall future emission of the structure during its prolonged lifetime (ICE, 2011:4). Therefore, the greatest influence of the civil engineers in the development of the low carbon infrastructure can be realized at the project appraisal stage, which will help the civil engineer

Significant Nutrition Problems Essay Example for Free

Significant Nutrition Problems Essay 1. List 3 significant nutrition problems associated with obesity in young children and adolescents. Cite references.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Three significant nutrition problems associated with childhood and adolescent obesity are hypothyroidism, type II diabetes, and dyslipidemia (Centers for Disease Control and Prevention, 2007). Hypothyroidism is the failure of the thyroid to produce thyroid hormones which is caused by certain nutrition problems such as increased cholesterol levels and low serum sodium. Type II diabetes is a condition wherein the body fails to properly utilize insulin due to the increase in glucose. Finally, dyslipidemia is a condition characterized by high blood cholesterol and increased triglycerides mainly due to consumption of foods high in fat (United States National Library of Medicine and National Institutes of Health, 2008). Factors that increase iron deficiency in older adults.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Among older adults, there are several factors that increase the occurrence of iron deficiency. These include the diet, age, and physical condition. Basically as people age, their physical abilities wear down, such as losing their teeth, and they tend to consume less food. As a result, the amount of iron in their body goes down. Another major factor is internal bleeding which is usually caused by tumors and ulcers among old people (KomoTV, 2008). When old people bleed, they lose iron and this eventually leads to iron deficiency. Food and Nutrition Information Center   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Basically, the difference between the food pyramid of old people and the food pyramid of children is that in the former there is more emphasis on the intake of foods that have more fiber and vitamins and less calories such as fruits and vegetables while the latter focuses more on whole grain foods and also fruits and vegetables. I believe that any older adult or child can adhere to the guidelines set by the pyramid because it is basically easy to follow. The only thing that hinders children from following the pyramid is the lack of guidance from parents while in older adults, there is lack of discipline. Otherwise, I believe that any person, no matter how young or old he or she is can follow these guidelines and be able to live a healthy life.   References Centers for Disease Control and Prevention. (2007). Obesity and Overweight. Retrieved April 24, 2008 from http://www.cdc.gov/nccdphp/dnpa/obesity/faq.htm. KotoTV.com. (2008). Iron Deficiency. Retrieved April 24, 2008 from http://ww3.komotv.com/global/story.asp?s=1230142. United States Department of Agriculture. (2008). Dietary Guidance: Food Guide Pyramid. Food and Nutrition Information Center. Retrieved April 24, 2008 from http://fnic.nal.usda.gov/nal_display/index.php?info_center=4tax_level=2tax_subject=256topic_id=1348. United States National Library of Medicine and National Institutes of Health. (2008). High blood cholesterol and triglycerides. MedlinePlus. Retrieved April 24, 2008 from http://www.nlm.nih.gov/medlineplus/ency/article/000403.htm. United States National Library of Medicine and National Institutes of Health. (2007). Hypothyroidism. MedlinePlus. Retrieved April 24, 2008 from http://www.nlm.nih.gov/medlineplus/ency/article/000353.htm. United States National Library of Medicine and National Institutes of Health. (2007). Type 2 diabetes. MedlinePlus. Retrieved April 24, 2008 from http://www.nlm.nih.gov/medlineplus/ency/article/000313.htm.

Fixed and random effects of panel data analysis

Fixed and random effects of panel data analysis Panel data (also known as longitudinal or cross-sectional time-series data) is a dataset in which the behavior of entities are observed across time. With panel data you can include variables at different levels of analysis (i.e. students, schools, districts, states) suitable for multilevel or hierarchical modeling. In this document we focus on two techniques use to analyze panel data:_DONE_ Fixed effects Random effects FE explore the relationship between predictor and outcome variables within an entity (country, person, company, etc.). Each entity has its own individual characteristics that may or may not influence the predictor variables (for example being a male or female could influence the opinion toward certain issue or the political system of a particular country could have some effect on trade or GDP or the business practices of a company may influence its stock price). When using FE we assume that something within the individual may impact or bias the predictor or outcome variables and we need to control for this. This is the rationale behind the assumption of the correlation between entitys error term and predictor variables. FE remove the effect of those time-invariant characteristics from the predictor variables so we can assess the predictors net effect. _DONE_ Another important assumption of the FE model is that those time-invariant characteristics are unique to the individual and should not be correlated with other individual characteristics. Each entity is different therefore the entitys error term and the constant (which captures individual characteristics) should not be correlated with the others. If the error terms are correlated then FE is no suitable since inferences may not be correct and you need to model that relationship (probably using random-effects), this is the main rationale for the Hausmantest (presented later on in this document). The equation for the fixed effects model becomes: Yit= ÃŽÂ ²1Xit+ ÃŽÂ ±i+ uit[eq.1] Where ÃŽÂ ±i(i=1à ¢Ã¢â€š ¬Ã‚ ¦.n) is the unknown intercept for each entity (nentity-specific intercepts). Yitis the dependent variable (DV) where i= entity and t= time. Xitrepresents one independent variable (IV), ÃŽÂ ²1 is the coefficient for that IV, uitis the error term _DONE_ Random effects assume that the entitys error term is not correlated with the predictors which allows for time-invariant variables to play a role as explanatory variables. In random-effects you need to specify those individual characteristics that may or may not influence the predictor variables. The problem with this is that some variables may not be available therefore leading to omitted variable bias in the model. RE allows to generalize the inferences beyond the sample used in the model. To decide between fixed or random effects you can run a Hausman test where the null hypothesis is that the preferred model is random effects vs. the alternative the fixed effects (see Green, 2008, chapter 9). It basically tests whether the unique errors (ui) are correlated with the regressors, the null hypothesis is they are not. Testing for random effects: Breusch-Pagan Lagrange multiplier (LM)The LM test helps you decide between a random effects regression and a simple OLS regression. The null hypothesis in the LM test is that variances across entities is zero. This is, no significant difference across units (i.e. no panel effect). Here we failed to reject the null and conclude that random effects is not appropriate. This is, no evidence of significant differences across countries, therefore you can run a simple OLS regression. EC968 Panel Data Analysis Steve Pudney ISER University of Essex 2007 Panel data are a form of longitudinal data, involving regularly repeated observations on the same individuals Individuals may be people, households, firms, areas, etc Repeat observations may be different time periods or units within clusters (e.g. workers within firms; siblings within twin pairs)+DONE_ Some terminology A balanced panel has the same number of time observations (T) on each of the n individuals An unbalanced panel has different numbers of time observations (Ti) on each individual A compact panel covers only consecutive time periods for each individual there are no gaps Attrition is the process of drop-out of individuals from the panel, leading to an unbalanced and possibly non-compact panel A short panel has a large number of individuals but few time observations on each, (e.g. BHPS has 5,500 households and 13 waves) A long panel has a long run of time observations on each individual, permitting separate time-series analysis for each_DONE_ Advantages of panel data With panel data: à ¢Ã¢â€š ¬Ã‚ ¢ We can study dynamics à ¢Ã¢â€š ¬Ã‚ ¢ The sequence of events in time helps to reveal causation à ¢Ã¢â€š ¬Ã‚ ¢ We can allow for time-invariant unobservable variables BUTà ¢Ã¢â€š ¬Ã‚ ¦ à ¢Ã¢â€š ¬Ã‚ ¢ Variation between people usually far exceeds variation over time for an individual à ¢Ã¢â‚¬ ¡Ã¢â‚¬â„¢ a panel with T waves doesnt give T times the information of a cross-section à ¢Ã¢â€š ¬Ã‚ ¢ Variation over time may not exist or may be inflated by measurement error à ¢Ã¢â€š ¬Ã‚ ¢ Panel data imposes a fixed timing structure; continuoustime survival analysis may be more informative Panel Data Analysis Advantages and Challenges Cheng Hsiao May 2006 IEPR WORKING PAPER 06.49 Panel data or longitudinal data typically refer to data containing time series observations of a number of individuals. Therefore, observations in panel data involve at least two dimensions; a cross-sectional dimension, indicated by subscript i, and a time series dimension, indicated by subscript t. However, panel data could have a more complicated clustering or hierarchical structure. For instance, variable y may be the measurement of the level of air pollution at station _ in city j of country i at time t (e.g. Antweiler (2001), Davis (1999)). For ease of exposition, I shall confine my presentation to a balanced panel involving N cross-sectional units, i = 1, . . .,N, over T time periods, t = 1, . . ., T._DONE_ There are at least three factors contributing to the geometric growth of panel data studies. (i) data availability, (ii) greater capacity for modeling the complexity of human behavior than a single cross-section or time series data, and (iii) challenging methodology. Advantages of Panel Data Panel data, by blending the inter-individual differences and intra-individual dynamics have several advantages over cross-sectional or time-series data: (i) More accurate inference of model parameters. Panel data usually contain more degrees of freedom and more sample variability than cross-sectional data which may be viewed as a panel with T = 1, or time series data which is a panel with N = 1, hence improving the efficiency of econometric estimates (e.g. Hsiao, Mountain and Ho-Illman (1995)._DONE_ (ii) Greater capacity for capturing the complexity of human behavior than a single cross-section or time series data. These include: (ii.a) Constructing and testing more complicated behavioral hypotheses. For instance, consider the example of Ben-Porath (1973) that a cross-sectional sample of married women was found to have an average yearly labor-force participation rate of 50 percent. These could be the outcome of random draws from a homogeneous population or could be draws from heterogeneous populations in which 50% were from the population who always work and 50% never work. If the sample was from the former, each woman would be expected to spend half of her married life in the labor force and half out of the labor force. The job turnover rate would be expected to be frequent and 3 the average job duration would be about two years. If the sample was from the latter, there is no turnover. The current information about a womans work status is a perfect predictor of her future work status. A cross-sectional data is not able to distinguish between these two possibilities, but panel data can because the sequential observations for a number of women contain information about their labor participation in different subintervals of their life cycle. Another example is the evaluation of the effectiveness of social programs (e.g. Heckman, Ichimura, Smith and Toda (1998), Hsiao, Shen, Wang and Wang (2005), Rosenbaum and Rubin (1985). Evaluating the effectiveness of certain programs using cross-sectional sample typically suffers from the fact that those receiving treatment are different from those without. In other words, one does not simultaneously observe what happens to an individual when she receives the treatment or when she does not. An individual is observed as either receiving treatment or not receiving treatment. Using the difference between the treatment group and control group could suffer from two sources of biases, selection bias due to differences in observable factors between the treatment and control groups and selection bias due to endogeneity of participation in treatment. For instance, Northern Territory (NT) in Australia decriminalized possession of small amount of marijuana in 1996. Evaluating the effects of decriminalization on marijuana smoking behavior by comparing the differences between NT and other states that were still non-decriminalized could suffer from either or both sorts of bias. If panel data over this time period are available, it would allow the possibility of observing the before- and affect-effects on individuals of decriminalization as well as providing the possibility of isolating the effects of treatment from other factors affecting the outcome. 4 (ii.b) Controlling the impact of omitted variables. It is frequently argued that the real reason one finds (or does not find) certain effects is due to ignoring the effects of certain variables in ones model specification which are correlated with the included explanatory variables. Panel data contain information on both the intertemporal dynamics and the individuality of the entities may allow one to control the effects of missing or unobserved variables. For instance, MaCurdys (1981) life-cycle labor supply model under certainty implies that because the logarithm of a workers hours worked is a linear function of the logarithm of her wage rate and the logarithm of workers marginal utility of initial wealth, leaving out the logarithm of the workers marginal utility of initial wealth from the regression of hours worked on wage rate because it is unobserved can lead to seriously biased inference on the wage elasticity on hours worked since initial wealth is likely to be correlated with wage rate. However, since a workers marginal utility of initial wealth stays constant over time, if time series observations of an individual are available, one can take the difference of a workers labor supply equation over time to eliminate the effect of marginal utility of initial wealth on hours worked. The rate of change of an individuals hours worked now depends only on the rate of change of her wage rate. It no longer depends on her marginal utility of initial wealth._DONE_ (ii.c) Uncovering dynamic relationships. Economic behavior is inherently dynamic so that most econometrically interesting relationship are explicitly or implicitly dynamic. (Nerlove (2002)). However, the estimation of time-adjustment pattern using time series data often has to rely on arbitrary prior restrictions such as Koyck or Almon distributed lag models because time series observations of current and lagged variables are likely to be highly collinear (e.g. Griliches (1967)). With panel 5 data, we can rely on the inter-individual differences to reduce the collinearity between current and lag variables to estimate unrestricted time-adjustment patterns (e.g. Pakes and Griliches (1984))._DONE_ (ii.d) Generating more accurate predictions for individual outcomes by pooling the data rather than generating predictions of individual outcomes using the data on the individual in question. If individual behaviors are similar conditional on certain variables, panel data provide the possibility of learning an individuals behavior by observing the behavior of others. Thus, it is possible to obtain a more accurate description of an individuals behavior by supplementing observations of the individual in question with data on other individuals (e.g. Hsiao, Appelbe and Dineen (1993), Hsiao, Chan, Mountain and Tsui (1989)). (ii.e) Providing micro foundations for aggregate data analysis. Aggregate data analysis often invokes the representative agent assumption. However, if micro units are heterogeneous, not only can the time series properties of aggregate data be very different from those of disaggregate data (e.g., Granger (1990); Lewbel (1992); Pesaran (2003)), but policy evaluation based on aggregate data may be grossly misleading. Furthermore, the prediction of aggregate outcomes using aggregate data can be less accurate than the prediction based on micro-equations (e.g., Hsiao, Shen and Fujiki (2005)). Panel data containing time series observations for a number of individuals is ideal for investigating the homogeneity versus heterogeneity issue. (iii) Simplifying computation and statistical inference. Panel data involve at least two dimensions, a cross-sectional dimension and a time series dimension. Under normal circumstances one would expect that the 6 computation of panel data estimator or inference would be more complicated than cross-sectional or time series data. However, in certain cases, the availability of panel data actually simplifies computation and inference. For instance: (iii.a) Analysis of nonstationary time series. When time series data are not stationary, the large sample approximation of the distributions of the least-squares or maximum likelihood estimators are no longer normally distributed, (e.g. Anderson (1959), Dickey and Fuller (1979,81), Phillips and Durlauf (1986)). But if panel data are available, and observations among cross-sectional units are independent, then one can invoke the central limit theorem across cross-sectional units to show that the limiting distributions of many estimators remain asymptotically normal (e.g. Binder, Hsiao and Pesaran (2005), Levin, Lin and Chu (2002), Im, Pesaran and Shin (2004), Phillips and Moon (1999)). (iii.b) Measurement errors. Measurement errors can lead to under-identification of an econometric model (e.g. Aigner, Hsiao, Kapteyn and Wansbeek (1985)). The availability of multiple observations for a given individual or at a given time may allow a researcher to make different transformations to induce different and deducible changes in the estimators, hence to identify an otherwise unidentified model (e.g. Biorn (1992), Griliches and Hausman (1986), Wansbeek and Koning (1989)). (iii.c) Dynamic Tobit models. When a variable is truncated or censored, the actual realized value is unobserved. If an outcome variable depends on previous realized value and the previous realized value are unobserved, one has to take integration over the truncated range to obtain the likelihood of observables. In a dynamic framework with multiple missing values, the multiple 7 integration is computationally unfeasible. With panel data, the problem can be simplified by only focusing on the subsample in which previous realized values are observed (e.g. Arellano, Bover, and Labeager (1999)). The advantages of random effects (RE) specification are: (a) The number of parameters stay constant when sample size increases. (b) It allows the derivation of efficient 10 estimators that make use of both within and between (group) variation. (c) It allows the estimation of the impact of time-invariant variables. The disadvantage is that one has to specify a conditional density of ÃŽÂ ±i given x Ëœ _ i = (x Ëœ it, . . ., x ËœiT ), f(ÃŽÂ ±i | x Ëœ i), while ÃŽÂ ±i are unobservable. A common assumption is that f(ÃŽÂ ±i | x Ëœi) is identical to the marginal density f(ÃŽÂ ±i). However, if the effects are correlated with x Ëœit or if there is a fundamental difference among individual units, i.e., conditional on x Ëœit, yit cannot be viewed as a random draw from a common distribution, common RE model is misspecified and the resulting estimator is biased. The advantages of fixed effects (FE) specification are that it can allow the individualand/ or time specific effects to be correlated with explanatory variables x Ëœ it. Neither does it require an investigator to model their correlation patterns. The disadvantages of the FE specification are: (a) The number of unknown parameters increases with the number of sample observations. In the case when T (or N for ÃŽÂ »t) is finite, it introduces the classical incidental parameter problem (e.g. Neyman and Scott (1948)). (b) The FE estimator does not allow the estimation of the coefficients that are time-invariant. In order words, the advantages of RE specification are the disadvantages of FE specification and the disadvantages of RE specification are the advantages of FE specification. To choose between the two specifications, Hausman (1978) notes that if the FE estimator (or GMM), ˆ ÃƒÅ½Ã‚ ¸_DONE_ ËœFE, is consistent whether ÃŽÂ ±i is fixed or random and the commonly used RE estimator (or GLS), ˆ ÃƒÅ½Ã‚ ¸ ËœRE, is consistent and efficient only when ÃŽÂ ±i is indeed uncorrelated with x Ëœit and is inconsistent if ÃŽÂ ±i is correlated with x Ëœit. The advantage of RE specification is that there is no incidental parameter problem. The problem is that f(ÃŽÂ ±i | x Ëœ i) is in general unknown. If a wrong f(ÃŽÂ ±i | x Ëœi) is postulated, maximizing the wrong likelihood function will not yield consistent estimator of ÃŽÂ ² Ëœ . Moreover, the derivation of the marginal likelihood through multiple integration may be computationally infeasible. The advantage of FE specification is that there is no need to specify f(ÃŽÂ ±i | x Ëœ i). The likelihood function will be the product of individual likelihood (e.g. (4.28)) if the errors are i.i.d. The disadvantage is that it introduces incidental parameters. Longitudinal (Panel and Time Series Cross-Section) Data Nathaniel Beck Department of Politics NYU New York, NY 10012 [emailprotected] http://www.nyu.edu/gsas/dept/politics/faculty/beck/beck home.html Jan. 2004 What is longitudinal data? Observed over time as well as over space. Pure cross-section data has many limitations (Kramer, 1983). Problem is that only have one historical context. (Single) time series allows for multiple historical context, but for only one spatial location. Longitudinal data repeated observations on units observed over time Subset of hierarchical data observations that are correlated because there is some tie to same unit. E.g. in educational studies, where we observe student i in school u. Presumably there is some tie between the observations in the same school. In such data, observe yj,u where u indicates a unit and j indicates the jth observation drawn from that unit. Thus no relationship between yj,u and yj,u0 even though they have the same first subscript. In true longitudinal data, t represents comparable time. Generalized Least Squares An alternative is GLS. If is known (up to a scale factor), GLS is fully efficient and yields consistent estimates of the standard errors. The GLS estimates of _ are given by (X0à ¢Ã‹â€ Ã¢â‚¬â„¢1X) à ¢Ã‹â€ Ã¢â‚¬â„¢1X0à ¢Ã‹â€ Ã¢â‚¬â„¢1Y (14) with estimated covariance matrix (X0à ¢Ã‹â€ Ã¢â‚¬â„¢1X) à ¢Ã‹â€ Ã¢â‚¬â„¢1 . (15) (Usually we simplify by finding some trick to just do a simple transform on the observations to make the resulting variance-covariance matrix of the errors satisfy the Gauss-Markov assumptions. Thus, the common Cochrane-Orcutt transformation to eliminate serial correlation of the errors is almost GLS, as is weighted regression to eliminate heteroskedasticity.) The problem is that is never known in practice (even up to a scale factor). Thus an estimate of , ˆ , is used in Equations 14 and 15. This procedure, FGLS, provides consistent estimates of _ if ˆ  is estimated by residuals computed from consistent estimates of _; OLS provides such consistent estimates. We denote the FGLS estimates of _ by Ëœ_. In finite samples FGLS underestimates sampling variability (for normal errors). The basic insight used by Freedman and Peters is that X0à ¢Ã‹â€ Ã¢â‚¬â„¢1X is a (weakly) concave function of . FGLS uses an estimate of , ˆ , in place of the true . As a consequence, the expectation of the FGLS variance, over possible realizations of ˆ , will be less than the variance, computed with the . This holds even if ˆ  is a consistent estimator of . The greater the variance of ˆ , the greater the downward bias. This problem is not severe if there are only a small number of parameters in the variance-covariance matrix to be estimated (as in Cochrane-Orcutt) but is severe if there are a lot of parameters relative to the amount of data. Beck TSCS Winter 2004 Class 1 8 ASIDE: Maximum likelihood would get this right, since we would estimate all parameters and take those into account. But with a large number of parameters in the error process, we would just see that ML is impossible. That would have been good. PANEL DATA ANALYSIS USING SAS ABU HASSAN SHAARI MOHD NOR Faculty of Economics and Business Universiti Kebangsaan Malaysia [emailprotected] FAUZIAH MAAROF Faculty of Science Universiti Putra Malaysia [emailprotected] 2007 Advantages of panel data According to Baltagi (2001) there are several advantages of using panel data as compared to running the models using separate time series and cross section data. They are as follows: Large number of data points 2)Increase degrees of freedom reduce collinearity 3) Improve efficiency of estimates and 4) Broaden the scope of inference The Econometrics of Panel Data Michel Mouchart 1 Institut de statistique Università © catholique de Louvain (B) 3rd March 2004 1 text book Statistical modelling : benefits and limita- tions of panel data 1.5.1 Some characteristic features of P.D. Object of this subsection : features to bear in mind when modelling P.D. à ¢Ã¢â€š ¬Ã‚ ¢ Size : often N (] of individual(s)) is large Ti (size of individual time series) is small thus:N >> Ti BUT this is not always the case ] of variables is large (often: multi-purpose survey) à ¢Ã¢â€š ¬Ã‚ ¢Ãƒ ¢Ã¢â€š ¬Ã‚ ¢ Sampling : often individuals are selected randomly Time is not rotating panels split panels _ : individuals are partly renewed at each period à ¢Ã¢â€š ¬Ã‚ ¢ à ¢Ã¢â€š ¬Ã‚ ¢ à ¢Ã¢â€š ¬Ã‚ ¢ non independent data among data relative to a same individual: because of unobservable characteristics of each individual among individuals : because of unobservable characteristics common to several individuals between time periods : because of dynamic behaviour CHAPTER 1. INTRODUCTION 10 1.5.2 Some benefits from using P.D. a) Controlling for individual heterogeneity Example : state cigarette demand (Baltagi and Levin 1992) à ¢Ã¢â€š ¬Ã‚ ¢ Unit : 46 american states à ¢Ã¢â€š ¬Ã‚ ¢ Time period : 1963-1988 à ¢Ã¢â€š ¬Ã‚ ¢ endogenous variable : cigarette demand à ¢Ã¢â€š ¬Ã‚ ¢ explanatory variables : lagged endogenous, price, income à ¢Ã¢â€š ¬Ã‚ ¢ consider other explanatory variables : Zi : time invariant religion ( ± stable over time) education etc. Wt state invariant TV and radio advertising (national campaign) Problem : many of these variables are not available This is HETEROGENEITY (also known as frailty) (remember !) omitted variable ) bias (unless very specific hypotheses) Solutions with P.D. à ¢Ã¢â€š ¬Ã‚ ¢ dummies (specific to i and/or to t) WITHOUT killing the data à ¢Ã¢â€š ¬Ã‚ ¢Ãƒ ¢Ã¢â€š ¬Ã‚ ¢ differences w.r.t. to i-averages i.e. : yit 7! (yit à ¢Ã‹â€ Ã¢â‚¬â„¢  ¯yi.)_DONE_ CHAPTER 1. INTRODUCTION 11 b) more information data sets à ¢Ã¢â€š ¬Ã‚ ¢ larger sample size due to pooling _ individual time dimension In the balanced case: NT observations In the unbalanced case: P1_i_N Ti observations à ¢Ã¢â€š ¬Ã‚ ¢Ãƒ ¢Ã¢â€š ¬Ã‚ ¢ more variability ! less collinearity (as is often the case in time series) often : variation between units is much larger than variation within units_DONE_ c) better to study the dynamics of adjustment à ¢Ã¢â€š ¬Ã‚ ¢ distinguish repeated cross-sections : different individuals in different periods panel data : SAME individuals in different periods à ¢Ã¢â€š ¬Ã‚ ¢Ãƒ ¢Ã¢â€š ¬Ã‚ ¢ cross-section : photograph at one period repeated cross-sections : different photographs at different periods only panel data to model HOW individuals ajust over time . This is crucial for: policy evaluation life-cycle models intergenerational models_DONE_ CHAPTER 1. INTRODUCTION 12 d) Identification of parameters that would not be identified with pure cross-sections or pure time-series: example 1 : does union membership increase wage ? P.D. allows to model BOTH union membership and individual characteristics for the individuals who enter the union during the sample period. example 2 : identifying the turn-over in the female participation to the labour market. Notice: the female, or any other segment ! i.e. P.D. allows for more sophisticated behavioural models e) à ¢Ã¢â€š ¬Ã‚ ¢ estimation of aggregation bias à ¢Ã¢â€š ¬Ã‚ ¢Ãƒ ¢Ã¢â€š ¬Ã‚ ¢ often : more precise measurements at the micro level Comparing the Fixed Effect and the Ran- dom Effect Models 2.4.1 Comparing the hypotheses of the two Models The RE model and the FE model may be viewed within a hierarchical specification of a unique encompassing model. From this point of view, the two models are not fundamentally different, they rather correspond to different levels of analysis within a unique hierarchical framework. More specifically, from a Bayesian point of view, where all the variables (latent or manifest) and parameters are jointly endowed with a (unique) probability measure, one CHAPTER 2. ONE-WAY COMPONENT REGRESSION MODEL 37 may consider the complete specification of the law of (y, ÃŽÂ ¼, _ | Z, ZÃŽÂ ¼) as follows: (y | ÃŽÂ ¼, _, Z, ZÃŽÂ ¼) _ N( Z_ _ + ZÃŽÂ ¼ÃƒÅ½Ã‚ ¼, _2 I(NT)) (2.64) (ÃŽÂ ¼ | _, Z, ZÃŽÂ ¼) _ N(0, _2 ÃŽÂ ¼ I(N)) (2.65) (_ | Z, ZÃŽÂ ¼) _ Q (2.66) where Q is an arbitrary prior probability on _ = (_, _2 , _2 ÃŽÂ ¼). Parenthetically, note that this complete specification assumes: y _2 ÃŽÂ ¼ | ÃŽÂ ¼, _, _2 , Z, ZÃŽÂ ¼ ÃŽÂ ¼(_, Z, ZÃŽÂ ¼) | _2 ÃŽÂ ¼ The above specification implies: (y | _, Z, ZÃŽÂ ¼) _ N( Z_ _ , _2 ÃŽÂ ¼ ZÃŽÂ ¼ Z0ÃŽÂ ¼ + _2 I(NT)) (2.67) Thus the FE model, i.e. (2.64), considers the distribution of (y | ÃŽÂ ¼, _, Z, ZÃŽÂ ¼) as the sampling distribution and the distributions of (ÃŽÂ ¼ | _, Z, ZÃŽÂ ¼) and (_ | Z, ZÃŽÂ ¼) as prior specification. The RE model, i.e. (2.67), considers the distribution of (y | _, Z, ZÃŽÂ ¼) as the sampling distribution and the distribution of (_ | Z, ZÃŽÂ ¼) as prior specification. Said differently, in the RE model, ÃŽÂ ¼ is treated as a latent (i.e. not obervable) variable whereas in the FE model ÃŽÂ ¼ is treated as an incidental parameter. Moreover, the RE model is obtained from the FE model through a marginalization with respect to ÃŽÂ ¼. These remarks make clear that the FE model and the RE model should be expected to display different sampling properties. Also, the inference on ÃŽÂ ¼ is an estimation problem in the FE model whereas it is a prediction problem in the RE model: the difference between these two problems regards the difference in the relevant sampling properties, i.e. w.r.t. the distribution of (y | ÃŽÂ ¼, _, Z, ZÃŽÂ ¼) or of (y | _, Z, ZÃŽÂ ¼), and eventually of the relevant risk functions, i.e. the sampling expectation of a loss due to an error between an estimated value and a (fixed) parameter or between a predicted value and the realization of a (latent) random variable. This fact does however not imply that both levels might be used indifferently. Indeed, from a sampling point of view: (i) the dimensions of the parameter spaces are drastically different. In the FE model, when N , the number of individuals, increases, the ÃŽÂ ¼i s being CHAPTER 2. ONE-WAY COMPONENT REGRESSION MODEL 38 incidental parameters also increases in number: each new individual introduces a new parameter.

Psycho, The Movie Essay -- essays research papers

Psycho (1960) Perhaps no other film changed so drastically Hollywood's perception of the horror film as did PSYCHO. More surprising is the fact that this still unnerving horror classic was directed by Alfred Hitchcock, a filmmaker who never relied upon shock values until this film. Here Hitchcock indulged in nudity, bloodbaths, necrophilia, transvestism, schizophrenia, and a host of other taboos and got away with it, simply because he was Hitchcock. The great director clouded his intent and motives by reportedly stating that the entire film was nothing more than one huge joke. No one laughed. Instead they cringed in their seats, waiting for the next assault on their senses. The violence and bloodletting of PSYCHO may look tame to those who have grown up on Jason and Freddy Krueger, but no one had ever seen anything like it in 1960. Inspired by the life of the demented, cannibalistic Wisconsin killer Ed Gein (whose heinous acts would also inspire THE TEXAS CHAINSAW MASSACRE, 1974 and DERANGED, 1974), PSYCHO is probably Hitchcock's most gruesome and dark film. Its importance to its genre cannot be overestimated. PSYCHO's enduring influence comes not only from the Norman Bates character (who has since been reincarnated in a staggering variety of forms), but also from the psychological themes Hitchcock develops. Enhancing the sustained fright of this film are an excellent cast, from which the director coaxes extraordinary performances, and Bernard Herrmann's chilling score. Especially effective is the composer's so-called "murder music," high-pitched screeching sounds that flash across the viewer's consciousness as quickly as the killer's deadly knife. Bernard Herrmann achieved this effect by having a group of violinists frantically saw the same notes over and over again. Hitchcock really shocked Paramount when he demanded that he be allowed to film the sleazy, sensational novel that Robert Bloch based on the Gein killings. Bloch's subject matter and characters were a great departure from the sophisticated homicide and refined characters usually found in Hitchcock's films, but the filmmaker kept after the studio's front office until the executives relented. He was told, however, that he would have to shoot the film on an extremely limited budget—no more than $800,000. Surprisingly, Hitchcock accepted the budget restrictions and went a... ...ces, nor was it a great performance or their enjoyment of the novel. They were aroused by pure film. That's why I take pride in the fact that PSYCHO, more than any of my other pictures, is a film that belongs to filmmakers." This was no news to Hitchcock's fans. In a 1947 press conference the great director laid out his philosophy of the mystery-horror genre: "I am to provide the public with beneficial shocks. Civilization has become so protective that we're no longer able to get our goose bumps instinctively. The only way to remove the numbness and revive our moral equilibrium is to use artificial means to bring about the shock. The best way to achieve that, it seems to me, is through a movie." PSYCHO provided shocks heard around the world and became an instant smash, breaking all box-office records in its initial release. Hitchcock had a horselaugh on the Paramount executives who wanted no part of PSYCHO from the beginning. The film became one of Paramount's largest grossing pictures and it made Hitchcock not only a master of the modern horror film but also fabulously wealthy. He had outwitted everyone—the industry, the audience, and the critics.