Black Holes Essays (3493 words) - Black Holes, Star Types

Black Holes Black holes are objects so dense that not even light can escape their gravity, and since nothing can travel faster than light, nothing can escape from inside a black hole . Loosely speaking, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. Since our best theory of gravity at the moment is Einstein's general theory of relativity, we have to delve into some results of this theory to understand black holes in detail, by thinking about gravity under fairly simple circumstances. Suppose that you are standing on the surface of a planet. You throw a rock straight up into the air. Assuming you don't throw it too hard, it will rise for a while, but eventually the acceleration due to the planet's gravity will make it start to fall down again. If you threw the rock hard enough, though, you could make it escape the planet's gravity entirely. It would keep on rising forever. The speed with which you need to throw the rock in order that it just barely escapes the planet's gravity is called the "escape velocity." As you would expect, the escape velocity depends on the mass of the planet: if the planet is extremely massive, then its gravity is very strong, and the escape velocity is high. A lighter planet would have a smaller escape velocity. The escape velocity also depends on how far you are from the planet's center: the closer you are, the higher the escape velocity. The Earth's escape velocity is 11.2 kilometers per second (about 25,000 M.P.H.), while the Moon's is only 2.4 kilometers per second (about 5300 M.P.H.).We cannot see it, but radiation is emitted by any matter that gets swallowed by black hole in the form of X-rays. Matter usually orbits a black hole before being swallowed. The matter spins very fast and with other matter forms an accretion disk of rapidly spinning matter. This accretion disk heats up through friction to such high temperatures that it emits X-rays. And also there is some X-ray sources which have all the properties described above. Unfortunately it is impossible to distinguish between a black hole and a neutron star unless we can prove that the mass of the unseen component is too great for a neutron star. Strong evidence was found by Royal Greenwich Observatory astronomers that one of these sources called Cyg X-1 (which means the first X-ray source discovered in the constellation of Cygnus) does indeed contain a black hole. It is possible there for a star to be swallowed by the black hole. The pull of gravity on such a star will be so strong as to break it up into its component atoms, and throw them out at high speed in all directions. Astronomers have found a half-dozen or so binary star systems (two stars orbiting each other) where one of the stars is invisible, yet must be there since it pulls with enough gravitational force on the other visible star to make that star orbit around their common center of gravity and the mass of the invisible star is considerably greater than 3 to 5 solar masses. Therefore these invisible stars are thought to be good candidate black holes. There is also evidence that super-massive black holes (about 1 billion solar masses) exist at the centers of many galaxies and quasars. In this latter case other explanations of the output of energy by quasars are not as good as the explanation using a super-massive black hole. A black hole is formed when a star of more than 5 solar masses runs out of energy fuel, and the outer layers of gas is thrown out in a supernova explosion. The core of the star collapses to a super dense neutron star or a Black Hole where even the atomic nuclei are squeezed together. The energy density goes to infinity. For a Black Hole, the radius becomes smaller than the Schwarzschild radius, which defines the horizon of the Black Hole: The death explosion of a massive star, resulting in a sharp increase in brightness followed by a gradual fading. At peak light output, supernova explosions can outshine a galaxy. The outer layers of the exploding star are blasted out in a radioactive cloud. This expanding cloud, visible long after the initial explosion fades from view, forms a supernova remnant. So, a black hole is an object, which is so compact that the

Human Computer Interaction Essays

Human Computer Interaction Essays Human Computer Interaction Essay Human Computer Interaction Essay The study of how people interact with computers and to what extent computers are or are not developed for successful interaction with human beings. What is HCI? â€Å"Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them† (ACM SIGCHI definition of HCI). Creating usable systems (1) HCI investigates interaction between Human (1 user, a group, sequence of users) Computer (any computer big or small, process control, embedded, etc) used to perform various tasks in particular environments. Creating usable systems (2) The human factors †¦ different users different conceptions or mental models about their interactions different ways of learning, keeping knowledge and skills cultural and national differences user preferences change as they gradually master new interfaces Creating usable systems (3) The com puter factor †¦ different devices Smart phones, Touch Screen Kiosks, †¦ different capabilities and limitations Computing power, Input/output devices, †¦ different operating systems user interface technology is changing rapidly it offers new interaction possibilities to which previous research findings may not apply Visual, Tactile, Gesture based, †¦Also read about  Knowledge of PC boot processCreating usable systems (4) What about the interaction? Communication between user and computer Direct interaction Dialogue with feedback Control throughout performance of the task Indirect interaction Batch processing Intelligent sensors controlling the environment Creating usable systems (5) It aims to achieve 1. Usability (Useful, Usable, Used) 2. Safe 3. Effective 4. Efficient 5. Enjoyable system Creating usable systems (6) User compatibility Product compatibility `Task compatibility Work flow compatibility Consistency Familiarity Simplicity Control Creating usa ble systems (7)HCI focuses on user needs by assessing interface design amp; implementation according to usability criteria. ? Makes use of new, novel techniques amp; technologies. It applies usability design principles to achieve more productive amp; usable systems and more satisfied users. Creating usable systems (8) EC Directive 90/270/EEC Requires employers to ensure the following when designing, selecting, commissioning or modifying software: suitable for the task easy to use where appropriate, adaptable to user’s knowledge amp; experiences Creating usable systems (9) provides feedback on performance displays information in a format amp; at a pace that is adapted to the user It must conform to the principles of software ergonomics (Ergonomics is the science that deals with the interaction between people/work/environment/psychology.It considers the functions of the human body in the design of tools, equipment, etc. ) Designers amp; employers can no longer afford to ign ore the user!! Question †¦ Have you ever used a system that exhibit good HCI with the users? Give a few examples †¦ What systems have you used that exhibit bad HCI with the users? Name a few †¦ and why do you think they were bad? Historical basis of HCI (1) Second World War †¦ Study of interaction between humans amp; machines in order to produce more effective weapons (Bletchley Park, Enigma, Colossus) Ergonomic Research Society formed (1949) Research in Man-Machine Interaction began to spread Historical basis of HCI (2) Historical basis of HCI (3) Historical basis of HCI (4) Basic Interaction (1) Graphical Objects 1963 (MIT) Graphical Objects manipulated by a pointing device (light pen) Objects could be selected, moved, resized, etc. 1966 (Imperial College, London) Icons, Gesture Recognition, Dynamic Menus, etc. 1970 (XEROX PARC) Object selection and manipulation WYSIWYG Basic Interaction (2) Mouse 1965 (Stanford Research Lab [SRI]) Created to be a cheap re placement for light pens 1970 Adopted at Xerox PARC First appeared commercially as part of The Xerox Star (1981), The Apple Lisa (1982), The Apple Macintosh (1984). Basic Interaction (3) Windows 1968 (Stanford Research Lab [SRI]) 1969 1974 (Xerox PARC) Smalltalk System 1974 (MIT) EMACS Text Editor 1981 (Xerox PARC) The Cedar Window Manager 1981 Xerox Star 1982 Apple Lisa 1983 (Carnegie Mellon University funded by IBM)) Andrew window manager 1984 Apple Macintosh The early versions of the Star and Microsoft Windows were tiled, but eventually they supported overlapping windows like the Lisa and Macintosh. Applications (1)Drawing programs uses a mouse for graphics (1965) uses a tablet (1971) handling of lines and curves (1975) Text Editing first word processor with automatic word wrap, search amp; replace, user-definable macros, scrolling text, amp; commands to move, copy, and delete characters, words, or blocks of text (1962) screen editing amp; formatting of arbitrary-sized strin gs with a lightpen (1967) mouse-based editing (1968) first WYSIWYG editor-formatter (1974) Applications (2) Spreadsheets initial spreadsheet was VisiCalc (1977-8) for the Apple II HyperText the idea where documents are linked to related documents (1945) Ted Nelson coined the term hypertext (1965) NLS system was one of the first on-line journals, and it included full linking of articles (1970) HyperCard from Apple (1988) significantly helped to bring the idea to a wide audienceTim Berners-Lee used the hypertext idea to create the World Wide Web in 1990 at the government-funded European Particle Physics Laboratory (CERN) Mosaic, the first popular hypertext browser for the World-Wide Web Eg: Cosmic Book Applications (3) Computer Aided Design (CAD) first CAD systems similar to drawing programs (1963) pioneering work on interactive 3D CAD system (1963) first CAD/CAM (manufacture) system in industry was probably General Motors DAC-1 (about 1963) Video Games first graphical video game was probably SpaceWar (1962) the first computer joysticks (1962) early computer adventure game was created (1966) first popular commercial game was Pong (about 1976). Up ;amp; Coming Areas (1) Gesture Recognition first pen-based input device used light-pen gestures (1963) first trainable gesture recognizer (1964) a gesture-based text editor using proof-reading symbols (1969) gesture recognition has been used in commercial CAD systems since the 1970s came to universal notice with the Apple Newton (1992)Multi-Media multiple windows with integrated text and graphics (1968) Interactive Graphical Documents project was the first hypermedia system which used raster graphics and text (1979-1983) Diamond project explored combining multimedia (text, spreadsheets, graphics, speech) (1982) Up ;amp; Coming Areas (2) 3-D first system 3-D CAD system (1963) first interactive 3-D system used for molecular modelling (1966) the late 60s and early 70s saw the flowering of 3D raster graphics funded by the government the military-industrial flight simulation work of the 60s 70s led the way to making 3-D real-time Virtual Reality original work on VR funded by Air Force (1965-1968) study of force feedback, early research on head-mounted displays and on the DataGlove (1971) Up ;amp; Coming Areas (3) Computer Supported Cooperative Work remote participation of multiple people at various sites (1968)Electronic mail, still the most widespread multi-user software, was enabled by the ARPAnet (1969) and by the Ethernet from Xerox PARC (1973) an early computer conferencing system (1975) Natural language and speech Speech synthesis Speech recognition HCI as a business necessity Can the users be ignored? (Linux, Windows,†¦) NO HCI + Usability engineering are a crucial business necessity Good Interface ;amp; Interaction Design should not Be added after system is built Supporting users is an integral part of the design. To do this one must consider †¦ International Standards in HCI and Er gonomics User population is growing (size, diversity, etc. ) Expanding awareness amongst users of what can be achieved Case Study (1) A mechanical syringe was once being developed. An input device had to be created in order to enter the injected dose. Design such a device †¦ Case Study (2) A prototype was developed by the manufacturing company and demonstrated to the hospital staff.Happily they quickly noticed the potentially fatal flaw in its interface. Case Study (3) The doses were entered by a numeric keypad: an accidental keypress and the dose could be out by a factor of 10! The production version had individual increment/decrement buttons for each digit . Safety-critical systems (1) Poor designs Very common in Safety Life-critical Which all depend on computer-control We need to understand why Disasters Accidents Frustrations happen? Can you mention some examples? Safety-critical systems (2) Computer failure hits post office Lancashire,  UK   Sep 5, 2006 A VILLAGE post office has been struck by a technical glitch, leaving customers unable to pay bills and collect benefits. Edgworth 999 Ambulance Computer Failure Putting Lives at Risk International News Service,  Australia   Aug 23, 2006 LIVES are being put at risk because of a crisis with London Ambulance Services computer-controlled 999 system. US Department of Energy sponsors storage research CTR,  CA   20 hours ago The data storage institute will focus its efforts in three areas: collecting field data about computer failure rates and application behaviors, disseminating Temporary failure hits Houston 911 center abc13. com,  TX   Sep 8, 2006 system. This past July, the Houston Emergency Center experienced a computer failure which knocked out the automated dispatch system. Warning on need for super reserves The Australian,  Australia   Sep 10, 2006 must maintain 4 per cent of assets in liquid form to meet any immediate needs, rising from banking and operational risks, such as computer failure or staff Book on IT debacles urges caution Stuff. co. nz,  New Zealand   Aug 27, 2006 That is the central theme of Dangerous Enthusiasms – E-Government, Computer Failure and Information System Development, a 160-page book just published by Search is on for escaped McMinn inmates Chattanooga Times Free Press,   USA   Sep 8, 2006 A computer failure that left 225 inmates under supervision of just four corrections officers may have contributed to the 4:59 pm | Computers delay Charlotte flights Charlotte Observer,  NC   Sep 6, 2006 two dozen US Airways Express flights going in and out of Charlotte were canceled Wednesday after a thunderstorm in Ohio led to a computer failure that affected Homes facing night without water BBC News,  UK   Aug 20, 2006 and Powys. The Pant storage tank ran dry after the water firm was not alerted to the problem because of a computer failure. She Safety-critical systems (3)Air-traffic control Aircraft crash due to problems pilot had to interpret information on cockpit display Manned spacecraft On June 4, 1996, the maiden flight of the European Ariane 5 launcher crashed about 40 seconds after takeoff. Media reports indicated that the amount lost was half a billion dollars. The error came from a piece of the software that was not needed during the crash!! Safety-critical systems (4) Nuclear power plant (The Meltdown at Three Mile Island 1979) â€Å"As alarms rang and warning lights flashed, the operators did not realize that the plant was experiencing a loss-of-coolant accident. They took a series of actions that made conditions worse by simply reducing the flow of coolant through the core. Medical Institutions Break down in the scheduling system led to delays in reaching seriously ill patients. (UK) Disaster examples 1988 USS Vincennes shot down an Iran Air A300 Airbus with 290 people aboardAegis weapon system had Sophisticated software to identify potential threats BUT Was una ble to provide up-to-date altitude information on its large display (this could be read from other screens) In the confusion, the Airbus which leveled off at 12,500 feet was taken to be an F-14 fighter descending to attack! ‘User Hostile’ example Poor HCI can lead to User Hostile systems rather than User Friendly ones †¦ John has a stereo system with a matched set of components made by the same manufacturer: a receiver, a CD player, and a cassette deck, stacked in that order. They all have the on/off button on the left side. Every time John goes to turn off all three components, he presses the top left button on the receiver, which turns it off; then he presses the top left button on the CD player, which turns it off; then, naturally, he presses the top left button on the cassette deck which pops open the cassette door. It’s obvious †¦It seems obvious that the manufacturer could have improved the interface putting all three buttons in the same locatio n But it clearly wasnt obvious to the systems designers!! Most actions used to accomplish tasks with an interface are quite obvious to people who know them, including, of course, the software designer. But the actions are often not obvious to the first-time user. Another example †¦ Imagine a first-time user of a computer 1. he has been shown how to login to the system 2. has done some work 3. is now finished with the computer for the day ? Experienced computer users will find it obvious that a logout command is needed. But it may not occur to first-time users that a special action is required to end the session. People dont log out of typewriters or televisions or video games, so why should they log out of computers? Learning to predict problems like these by taking the users point of view is a skill that requires practice. Who studies HCI? (1) Multi-discipline field †¦ Who studies HCI? (2) Conclusion (1) HCI studies Interaction between users amp; computer systems In order to build systems which are: Usable Safe Efficient Effective Enjoyable Conclusion (2) Important points to keep in mind †¦ 1. You need a lot of common sense 2. You must be ready to accept criticism 3. Think ‘user’ 4. Try it out (They know what they want! ) 5. Involve the users 6. Iterate Exercise If we take a toaster Describe: the users the machine seems to be designed for; the tasks and subtasks the machine was evidently designed to support; the interface part of the machine; the part of the machine that is NOT the interface. What about an electric drill

Management Assignment Example | Topics and Well Written Essays - 2000 words

Management - Assignment Example For example, the sales department had pointed out that there was inadequate support from the marketing department and for this reason, poor sales had resulted. On the other hand, according to the Director of the marketing department, the design and quality of the product were the major causes of the problem. In order to deal with the problems, a restructure plan was required to be formulated which would best suit the company. The following restructure model can be used: Source: 1 Chinese Apparel Industry Facts From the year 2003, there has been an increase in the market size of the Chinese apparel sector from USD 47,194 million to USD 78,459 million in the year 2009 at a CAGR of 8.8%. In the year 2009, there was a sharp decline in growth rate, where the market slumped due to economic chaos. From USD 95,540 million in the year 2008, the market declined to USD 78,459 million in the year 2009, which was estimated to be a decline of 17.9% of growth2. Diagnosis Internal Analysis of the Sp ortswear Company in China There were multifarious reasons that led the sportswear company in China to suffer losses such as lack of support from the marketing department and poor design and quality of the products. ... They should be aware of different rules and regulations imposed by the government including the taxation policy. Since the Sportswear Company in China is itself manufacturing the products, there is possibility of unfavorable changes in political and trade relations between Singapore and China. The political instability in China, increase in labor costs, or unfavorable weather conditions could considerably get in the way of the production and the shipment of the products of the company, which would in turn affect their operations and financial results. Economic: The sportswear company is also affected by the economy of the country. The stability of interest rate in the country is also a significant factor which can have an impact. A high rate of interest will result in the fall of demand of the product making the borrowings expensive and savings attractive. On the other hand, a low rate of interest leads to increase in the inflation. The company should also take the tax into considera tion. Mainly the taxes are of two types namely direct and indirect. Direct tax cannot be avoided and it affects the personal disposable income. People can avoid Indirect tax such as VAT by not purchasing the products. The high rate of interest in China has led to the fall in the demand of the products in the last two years thereby resulting in the losses for the company. But with the improvement in the living standards of the people of China and also changes in their consumption level, sportswear companies are becoming popular among the people, thereby enhancing the businesses of sportswear manufacturing companies in China. Social: The company should also take into consideration the

Economic and Political Motives for European Expansion into Africa Essay

Economic and Political Motives for European Expansion into Africa - Essay Example Missionaries persuaded their respective European governments to colonize Africa and thereby provide a supportive environment for the expansion of commerce. European powers used mineral exploitation, large-scale agricultural production, mixed economies as well as the supply of labor as modes of economic activity to generate revenue in colonial Africa. The major political reason that led to European expansion in Africa was political rivalries between the countries. England and France loathed one another for a considerable length of time due to the infamous hundred year’s war, and they both wanted to outdo each other in Africa. Nonetheless, the race for power was not limited to France and Britain. Other European nations wanted to benefit as well. Nationalism was popular among most western European nations as each nation wanted to be strongest. Nationalism is a strong identification with and pride in one's nation.This resulted in competition between European powers leading to wars . This competition made most nations to acquire more territories to uphold the spirit of nationalism in order to be seen superior than other nations. The strategy was another political reason for colonization of Africa. Most European countries were keen to maintain control of specific territories for strategic reasons. The British considered that South Africa offered a useful stop for ships on their way to India. Besides, the Suez Canal in Egypt significantly created a much shorter route between the UK and her colonies further east.

Elder abuse Essay Example | Topics and Well Written Essays - 750 words

Elder abuse - Essay Example Remember that perpetrators spend months, and sometimes years, to set up their victims for exploitation. Conclusion: By the time Patricia Murtaugh was finished with her two victims, she had emptied their bank accounts of almost half-a-million dollars and used the money to open up a business and purchase homes, cars, and a boat. Her victims were broke and although Murtaugh was arrested and convicted for her crimes, it is doubtful that they will ever see their money again. Murtaugh went to jail, but most victimizers get away with their crimes. Breton, T. (January 9, 2007). A Trust Betrayed: How Two Women in Their 90s Were Fleeced by a Helper. Rhode Island News. Retrieved from http://www.projo.com/news/content/Murtaugh_01-07-07_2034LD5.21a31c1.html. We’ve all heard, I’m sure, of severe cases of elder abuse, in which older people are physically abused by younger people, usually family members. There are some horrific cases of the elderly being victimized, sometimes to the point of death. I’d like to talk about another type of elder abuse—economic exploitation, which is often just as devastating. One of the most notorious cases of economic exploitation of the elderly happened in 2007 in New York. Patricia Murtaugh swindled hundreds of thousands of dollars from two women in their nineties, women who had spent fifty years wisely saving their money. Over a period of months, she gained their trust and then stole their life savings. At first, she was helpful, providing both women with the assistance so that they could keep their independence, in the form of bill paying and much-appreciated companionship. Eventually, she was able to gain access to their finances, a common approach of many a victimizer. This kind of elderly abuse is more common than you may think. One in five elderly Americans are victims of financial exploitation, and in some areas, that figure may be as high as 50%.

Neural Grafts for PD Symptoms

Neural Grafts for PD Symptoms New Neurons for Old The Swedish neuroscientist Patrik Brundin was twelve years old when his father was diagnosed with PD. He resolved to devote his life to finding a cure for the disease and elected to study medicine at Lund University in Sweden. In the late 1990s, he joined Anders Bjà ¶rklund, a pioneer of neural transplantation, to work on a series of neural grafts aimed at reversing the symptoms of PD. A neural graft is an experimental procedure for transplanting neural tissue into the brain. The operations were controversial because the transplanted neural tissue came from aborted fetuses. Research had shown that the optimal time to transplant human fetal-brain tissue from the substantia nigra was from six to eight weeks after fertilization. Because only 10 percent of the fetal cells are likely to survive the entire procedure, the neurosurgeon may need to implant cells from multiple fetuses in one operation. To prepare for the operation, the fetal tissue has to be dissected under the microscope so that only those cells whose destiny is to make dopamine would be transplanted. Attached to the substantia nigra tissue are cells that have different fates to become cartilage, skin, etc. If the surgeon isnt careful and grafts these cells into the brain, theyd grow into big bits of skin and cartilage. It is a delicate process. The entire fetus is only the size of a fingernail; the substantia nigra, the size of a pin. After hours of painstaking dissection, the fetal cells will be mixed with a chemical called trypsin to dissociate the cells into a liquid suspension. Researches with rats had shown that fetal cells grafted in the substantia nigra did not reverse PD-like symptoms, because the grafted nerve fibers could not grow long enough to reach their targets in the striatum. So the neurosurgeon will implant the fetal cells in the striatum. In the 1990s, 18 cases of neural grafting operations were conducted at Lund, and over 300 worldwide, with encouraging results. By 1999, many people believed this method is the only way to cure PD. But for others, the results were uncontrolled trials with a potential for a placebo effect. This led two teams in the United States to propose controlled blind trials of fetal tissue transplantation operations. Patients entering the trial would be assigned to one of two groups: a treatment group and a control group. Patients would not know which group they were in and would continue taking their regular dopaminergic medication. The first study performed the trial separately for people over and under sixty. The doctors held follow-up meetings with the patients for twelve months. In 2001, the team reported the results. The over-sixty treatment group experienced no measurable improvement compared to the control group. The under-sixty treatment group got some improvements, but the researchers found worrying evidence of adverse side effects: facial dystonias and dyskinesias. Unlike L-dopa-induced dyskinesias, which disappear as patients medication wears off, these dyskinesias were coming from the graft, and they were permanent. The second study assigned the patients randomly to two treatment groups one using material from a single fetus, the other using material from four fetuses and a control group. The groups were followed for two years and tested using UPDRS. There was no difference between the three groups, showing that fetal dose didnt matter, and again some patients developed graft-related dyskinesias. These two studies killed the field of neural transplantation. A decade after these studies, Brundin is still a strong supporter of neural grafting. He claims the studies had numerous flaws. Brundin may be correct about neural graftings efficacy. It worked in the cases of two patients in the Lund series. The two patients were diagnosed thirty years ago. Both responded well to L-dopa, but developed severe L-dopa-induced motor complications. In the 1990s, they went to Lund, where the surgeons transplanted dopaminergic fetal tissue into the striatum on both sides of their brains. After four years, both patients could drop all dopaminergic mediations. Their PET scans showed clear signs of new dopamine production in the striatum, and their motor states, as measured by the UPDRS, showed a sustained benefit. These cases showed that this bold strategy can work and serve as a caution against dismissing neural grafts prematurely. The early scientific trials of levodopa failed. But scientists like George Cotzias persisted and worked out the correct dosing regimen, and the failure turned into spectacular success. In Europe, a large trial called TRANSEURO is under way involving some 150 patients. The work might redeem neural grafting. In the last few years, a potential alternative to fetal cells and embryonic stem cells has become available. In 2006, Japanese researcher Shinya Yamanaka showed in mice that ordinary skin cells could be reprogrammed to become pluripotent capable of becoming any cell. Soon after, Yamanakas technique was achieved with human skin cells. Rather than using fetal cells, researchers can take a patients own skin cells, reprogram them to become so-called induced pluripotent stem cells (iPSCs), then let them develop into dopamine neurons. These neurons can be studied in the lab or grown for neural grafts. Such iPSCs not only bypass the ethical issues plaguing embryonic stem cells, but also have other advantages. Because iPSCs are derived from the patients own cells, there is no need for immunosuppressive drugs. But because there is a risk that such cells might turn cancerous, it may take decades to develop a safe and effective procedure. Key Takeaways In the late 1990s, Patrik Brundin worked on a series of neural grafts aimed at reversing the symptoms of PD. Two controlled blind trials of fetal tissue transplantation operations conducted in the United States in early 2000s showed that the treatment group experience no measurable improvement compared to the control group. It was also worrisome that some patients developed graft-related dyskinesias. In 2006, Shinya Yamanaka showed that ordinary skin cells could be reprogrammed to become pluripotent.

Exploring Traumatic Brain Injury in Children Essay -- Medicine

Traumatic brain injury (TBI) is a leading cause of death and disability among children and adolescents (Yeates, 2005). The Center for Disease and Control (2010) reported an estimated 1.7 million individuals sustaining TBI annually with 51% of these injuries occurring during periods of cerebral development. Children (0-4 years), older adolescents (15-19 years) and older adults (65+ years) are most likely to sustain TBI (CDC, 2010). Brain injuries often lead to severe, pervasive, and potentially irreversible impairments in one’s neurological, cognitive, emotional, and social functioning (e.g., Wilde et al, 2012; Yeates, 2005). This analysis will examine the etiology, prevalence, and impact of traumatic brain injury in the developing brain of children. Classifications & Diagnosis of TBI Brain injuries can be classified into three different categories: mild, moderate, and severe TBI. Classification is mostly done using the Glasgow coma scale (GCS) which has gained broad acceptance for the assessment of the severity of brain damage (Bauer & Fritz, 2004). This scale is based on a 15 point scale which measures individual’s level of consciousness based on verbal, motor, and eye responses to stimuli, as well as the overall social dependence on others. One study scrutinized the elements of the Glasgow coma scale (GCS) from 27,625 TBI cases in Taiwan. A correlation was found between the survival rate and certain eye (E), motor (M) and verbal (V) score combinations for GCS (scores of 6, 11, 12, ) that were discerned to be statistically significant. This illustrates that the fundamental elements comprising the Glasgow coma scale (E, M, & V) are predictive of the survival of TBI patients. The researchers assert that this observation is cli... ...sciencedirect.com/science/article/pii/S0020138309005609) Wilde, Merkley, Bigler, Max, Schmidt, Ayoub, McCauley, Hunter, Hanten, Li, Chu, Levin, Longitudinal changes in cortical thickness in children after traumatic brain injury and their relation to behavioral regulation and emotional control, International Journal of Developmental Neuroscience, Volume 30, Issue 3, May 2012, Pages 267-276, ISSN 0736-5748, 10.1016/j.ijdevneu.2012.01.003. (http://www.sciencedirect.com/science/article/pii/S0736574812000044) Yeates, Armstrong, Janusz, Taylor, Wade, Stancin, Drotar, Long-Term Attention Problems in Children With Traumatic Brain Injury, Journal of the American Academy of Child & Adolescent Psychiatry, Volume 44, Issue 6, June 2005, Pages 574-584, ISSN 0890-8567, 10.1097/01.chi.0000159947.50523.64. (http://www.sciencedirect.com/science/article/pii/S0890856709616336)

Prejudice and Discrimination Essay

What is social psychology? Social psychology is defined as the scientific study of how a person’s behavior, thoughts, and feelings are influenced by the actual, imagined or implied presence of other human beings. As we look back over the past few years, we see that some form of prejudice and discrimination still exist today in society. I want to elaborate on and define the types of prejudices and how people discriminate, how they are learned, and how to overcome prejudice. Prejudice is defined as a preconceived judgment or opinion that is usually based on limited information about a group or groups of people. Some people would commonly agree that prejudice is stereotyping. Discrimination is prejudicial attitudes that cause members of a particular social group to be treated differently than others in situations that call for equal treatment. There are many kinds of prejudices or attitudes, but discrimination is a result of prejudice. Several ways in which people are discriminated upon include age, race, and sex. People are often prejudice toward those form different ethnic groups, those form different religions, those from different economic levels, those who are overweight, and those who are too thin. Prejudice vary in two different types of groups called the in-groups and the out-groups or the â€Å"us† versus â€Å"them†. These groups are formed early in childhood. The in-groups are considered to be the particular person for whom they are identified with and the out-group is to be considered everyone else. Soon after the in-groups are established, the prejudice and discriminatory treatment of the out-group or groups soon follow. Then the out-groups are stereotyped based on the color of their skin or color of their hair and can be difficult. There are many laws that are in place to minimize or control the discriminatory behavior, but there is no law against having a certain attitude. The realistic conflict theory in prejudice is the increase of prejudice and discrimination by a degree of conflict between in-groups and the out-groups over limited resource, such as land or a job. A current example not related to land but religion would be, according to, â€Å"Neal Broverman, of The Advocate, Virginia’s lower house passed that would allow student groups at public universities to deny members because they conflict with the groups’ religious beliefs. This bill would prohibit discriminating against a student organization or group on the basis of the religious, political, philosophical or other content of the organization or group’s speech. † The bill also allows religious or political student organizations to determine who will not be allowed in their membership â€Å"in furtherance of the organization’s religious or political mission. â€Å"

Cold Sassy Tree essays

Cold Sassy Tree essays In the novel, Cold Sassy Tree, Olive Ann Burns explores timeless issues of love, death, and the ties that bind families and generations. The story also shows the modern age coming to a small southern town. Will Tweedy, a 14-year-old boy, who could always make a good story better in the telling, narrates this story. By the story being told in the first person point of view, the reader is able to experience the thoughts of the characters. The first person point of view brings the reader directly into the scene. Will looked up and saw T.R. raise his head to listen, but he thought, surely it wasnt near time for the train. He heard clickety-clack and screeched the train was coming. After reading this, the reader can share Wills feelings with him. Then, both the reader and Will, start to think how will is going to get off the trestle before the train gets there. Will could have gotten away easily, but as he scrambled to his feet, I stumbled and fell, he said, and I saw I couldnt possible make it off the trestle. In sudden shock, the reader takes a quick breath with Will. This makes the reader start to worry and wonder, even more, what Will is going to do to get away from the train. In conclusion, first person point of view helps the reader experience the thoughts of the characters. This novel is very rich with emotion, humor, and love. Olive Ann Burns does a good job in keeping the reader so interested in the book that they do not want to put it down. ...

A Gab of Sky by Anna Hope Essays

A Gab of Sky by Anna Hope Essays A Gab of Sky by Anna Hope Paper A Gab of Sky by Anna Hope Paper To be united with many, and still feel so alone In the vastness of great cities a feeling many can relate to. Every man and woman wakes up, steps out into world, making their way through the endless clutter of human beings, each one with a vast amount of goals, that must be achieved and destinations that must be reached. Part of growing up has, in stereotypical fashion, been said to be to accept this reality; the reality of having to check off the to-do-list every day. It might only be a luxury of youth that one can refrain from this, and let ones Instinctive ambition and desires ale. To be controlled by the Immediate wants and thoughts of ones mind and heart. This is exactly what Elli, the main character of A Gap of Sky, by Anna Hope, does. Engulfed by the city, and its pulsating, never-ending tempo the reader follows the young Elli in her simple goal of purchasing some computer ink. On her quest though, she is taken over by sudden urges and curiosity. She lets herself sway away from her path. Elli is a 19 year old girl, living the carefree and extreme life, in the buzzing city of London. One assumes she Is studying English at some sort of university, due to the fact her mall goal for the day Is to write an essay on Virginia Wolf. As she lies in her bed, the reader meets her waking up from a crazy night on the town, enriched with alcohol and drugs. She regrets nothing and seems to be living the life, where every moment is precious and must be enjoyed to the fullest. Suddenly she realizes it is Monday, and the harsh realities creep up upon her. She must write and hand In this essay the next day, but she has no printer Ink. So she sets herself the goal of buying the printer Ink, and thereafter writing the essay. It Is a bright, sunny, yet cold day, that wraps her body and hurts her lungs, as she scatters through the city in search for a computer store. She is overwhelmed by all the impressions, and seduced by her curiosity she wonders off her path. In an odd exhibition of some sort her head begins to throb. The pain brings about a sense fear, desperation and despair in her. The concept of death begins to dance in her consciousness. She seeks out a river, to relieve her from this agonizing pain. On her way she begins to feel better, and following a stranger she enters a store of some sort. There she picks up a little stone: a stone that brings about a melancholic sensation in her. She begins to reminisce about her mother, who the summer before had given Elli a stone like this one, for good luck. She repeats her mothers name to herself, picturing her in her head, which make her feel lighter, alive and beautiful. A feeling she hopes the world can see. She wants to share it with the world. Walking out onto the street again, she sees how, all around people are Interconnected by the bond of love, that she herself feels. Skirting away again, remembering her need for imputer-ink, she once again makes her way through the city. She has though, not forgotten the river, she searches a terrace from where she can admire it. The night above receives her, and she at the end notes to herself all her goals, and how all is good. The narrator is a third person-omniscient, using the narrative technique; stream of consciousness, a technique the writer and feminist Virginia Wolf used In many AT near works I Is . N stream casts ten reader In many alertness, Owe to Ell being very distracted and unfocused. This technical reference to Virginia Wolf could e considered an inter-textual element. It could be a result of ingesting drugs she changes her focus by the second, for example; Monday. It is Monday. Essay there is an essay due, important, due for Tuesday morning ( ) and so on. Her thoughts are hurriedly rushed through. The narration Jumps from subject to subject, as if one were inside the head of the young Elli. It is chaotic and frantic, much like the city of London, which is the setting of the story. It could be concluded that this is the authors purpose. Her mind is dark, and almost lacks a sense of structure, much like en could say about a big busy city, like London. Elli is constantly on the move, drawing parallels to the pulsating city. Her attitudes towards things seems rebellious, exemplified by her content and giggle when she sees a glove on a fence, flicking the world off. She does not feel accountable to anyone. The exhibition she stumbles upon has the theme Living and Dying, a theme is very precedent throughout the story. She does not feel ready to die; she is alive, and grateful to be so. The city does though have a power over her. It can both bring her down and up again. At one moment the city brings about fear, and sadness in her, making her feel nasty, brutish, and short (A. Hope, pig. 4 1. 8). As her headache passes, light is cast down onto the street, leaving her feeling rancid and worn. She realizes how short and precious life is. An epiphany described as a Gab in the sky. Making her way to the river, representing a crossroad in her life, she is faced with a choice. She can either drown herself in the cities murky river, like Virginia Wolf did, who is referred to earlier in the story. Or she can wash herself clean -clean from drugs.

Foreign Exchange Markets and Globalization Essay

Foreign Exchange Markets and Globalization - Essay Example For corporations the four main roles of the foreign exchange markets are: currency conversion, currency hedging, currency speculation and currency arbitrage (Madura, 1992). Currency conversion is one of the most used functions of the exchange for corporations trading or doing business internationally. Entities use the exchange to convert one currency to another. From the purchase of finished goods or raw materials from foreign suppliers to being able to sell your product or service internationally being converting one currency to another efficiently is paramount to global business. The foreign exchange quotes two rates the spot and forward rate prices. The current daily exchange rate between two currencies is called the spot exchange rate (Bodie & Kane & Marcus, 2002). It is used for immediate payments or financial transactions. The value of any currency is realized by the interaction between the demand and supply of a currency relative to the demand and supply of other currencies. I t is a dynamic market where rates are constantly changing based on the volume of activity for any given currency. Since a lot of business transactions do not require payment until a later date, the forward exchange rate provides a currency exchange rate for 30, 60 and 90 days.

The wrongs of Obama Care Research Paper Example | Topics and Well Written Essays - 4000 words

The wrongs of Obama Care - Research Paper Example es to develop as they tend to have a lesser margin of profit and does not have extra costs compared to large businesses.4 Under these conditions, it can be implied that such act as the Obamacare could only generate a negative impact towards the health care system and it even makes erroneous government programs towards the workers employed in small businesses that do not support health insurance. Similarly, Nina Bernstein of the New York Times reported that the Affordable Care Act establishes state exchanges in reducing the cost of commercial health insurance, however, it needs a proof of citizenship or legal immigration status by the immigrants in order to â€Å"take part and apply for Medicaid benefits† provided under the law.5 This essay seeks to discuss and analyze the essential components characterized by the Patient Protection and Affordable Care Act (PPACA), or Obamacare as recognized by most people. These features include funding, regulation, taxing, and individual mand ate, wherein President Obama himself considers such legislation to be favorable and beneficial to the US economy. 2.0 Funding In one of the latest news concerning Obamacare, John Fund reported that the plan to cut $200 billion from Medicare Advantage and use the money in subsidizing the coverage of expansion to millions of Americans uninsured in the government’s program for the poor, or Medicaid is one of the misleading falsehood or deceptions of Obamacare, wherein such deception remains to be concealed as the US presidential election is fast approaching.6 Accordingly, the administration also plans to direct an approximately $8.3 billion to the Medicare Advantage, which according to the news, is sufficient to compensate about 71 percent of the cuts intended for the program this year and until 2014. However, California Representative, Darrell Issa says that the attempt to direct $8.3 billion into the Medicare Advantage is the primary reason to hide the possible trouble of havi ng a $200-billion cut, and the so-called â€Å"demonstration project,† as Representative Issa noted, is a â€Å"political fiction† that can be used in buying the votes of the electorate in this year’s upcoming election.7 Unfortunately, the probabilities of implementing Obamacare and be legally enforced into the health care system will eventually compel the seniors to retract to the traditional system of Medicare at an expense greater than the current one, and in the long run, this could spur doubts on President Obama’s statement that under such law, anyone who supports his program on health insurance are capable of sustaining it.8 As provided under section 1311-1313 of the Act,9