Wired and Wireless Networks

Wired and Wireless, What’s the Difference? The main difference between a wired and wireless data communication infrastructure is the existence of physical cabling. The same or similar techniques are employed for both types of data communication infrastructure in terms of the core elements of essential network services. The basic difference between a wired and a wireless network is self-explanatory. A wired network uses wires to communicate whereas a wireless network uses radio waves. Another difference and how one technology gets an edge over the other. Wired networks are easy to set up and troubleshoot where wireless networks are comparatively difficult to set up, maintain, and troubleshoot. Wired networks make you immobile while wireless ones provide you with convenience of movement. A third difference, wired networks prove expensive when covering a large area because of the wiring and cabling while wireless networks do not involve this cost. Wired networks have better transmission speeds than wireless ones. In a wired network, user does not have to share space with other users and thus gets dedicated speeds while in wireless networks, the same connection may be shared by multiple users. One of the most common questions we have to answer on a daily basis is the difference between wired and wireless networks. Wired is the communication between two devices via cables. Wireless is the communication between two devices without cables. Now, is it that simple? Each method of networking has its own pros and cons. Wireless networks do not use any form of cable. The transmission of data occurs over radio waves just like cordless phones or the Bluetooth headset that came with that phone you purchased . There are many advantages, but the major advantage of having a wireless device is the mobility and freedom that comes with it. There is less clutter and fewer wires to worry about. But, you sacrifice in most cases on speed and security. Wired networks on the other hand have been around for some time now. Officially known today as the Ethernet, the cables usually connect these devices using CAT5 cables. The speed and security in this scenario are greatly enhanced. The latest Ethernet routers can support up to 1000Mb/s or a Gigabit/second, that’s ten times faster than the widely used 100 Mb/s router. However the overall cost of a wired network is lower and provides high performance and better security than wireless networks. As home users, wireless networks have become the choice. A wireless network saves your time and efforts in installing a lot of cables. Also, if you need to relocate a client machine in your office, you only need to move the computer with wireless network. Wireless networking is very useful in the public places, libraries, hotels, schools, airports, train stations. A drawback in the wireless internet is that quality of service, it is not guaranteed if there is any interference. Then the connection may be dropped. Wireless local area networks allow users in local area, such as in a university or a library to join a network and gain wireless access to the internet. A temporary network can be formed by a small number of users without the need of access points. Service Set Identifier acts a simple password by allowing WLAN network to be split up into different networks and each having a unique identifier. These identifiers are configured in multiple access points. To access any of the networks, a computer is configured in such a way that each is having a corresponding identifier for that network. If they match between the two computers or networks then access is granted. This is a good security method but it is mainly involved in the small wireless networks because there is more manual work is involved, entering the MAC address into the Access point. Wireless networking is very popular in home networking and more than 20 percent of homes with broadband internet are using wireless networks and this number is increasing. In a general estimate worldwide hotspots have now reached more than 30,000 and will grow about 210,000 in the next few years. Most large hotels already offer Wi-Fi and the business travelers are willing to pay for the wireless access. 802. 11 is the next Wi-Fi speed standard. It is set to offer bandwidth around 108Mbps and is still under development. With the speed of 70 Mbps and a range up to 30 miles, the 802. 1 standard, known as Wimax is sure to give a boost to wireless networking. The term wireless networking refers to technology that enables two or more computers to communicate using standard network protocols, but without network cabling. Any technology that does this could be called wireless networking. This technology, fueled by the emergence of cross-vendor industry standards such as IEEE 802. 11, has pro duced a number of affordable wireless solutions that are growing in popularity with business and schools as well as sophisticated applications where network wiring is impossible, such as in warehousing or point-of-sale handheld equipment. An ad-hoc, or peer-to-peer wireless network consists of a number of computers each equipped with a wireless networking interface card. Each computer can communicate directly with all of the other wireless enabled computers. They can share files and printers this way, but may not be able to access wired LAN resources, unless one of the computers acts as a bridge to the wired LAN using special software. Each computer with a wireless interface can communicate directly with all of the others. A wireless network can also use an access point, or base station. In this type of network the access point acts like a hub, providing connectivity for the wireless computers. It can connect (or â€Å"bridge†) the wireless LAN to a wired LAN, allowing wireless computer access to LAN resources, such as file servers or existing Internet Connectivity. That’s the different between wired and wireless network. BIBLIOGRAPHY 1. http://computer. howstuffworks. com/home-network2. htm 2. http://en. wikipedia. org/wiki/Wireless_network 3. http://www. broadbandbuddy. com. au/wireless-broadband/wireless-networks-vs-wired-networks

Computers and Education Essay

Nowadays, it is generally believed that computers are essential for our modern education. They are indispensable studying tool that makes it easier for many people to learn subjects from mathematics to language skills. However, there are some aspects of a good education that cannot be taught using computers. Computers play a significant role in all fields of modern society. They are widely used by banks for account management and by stores for keeping records of sales and inventory. Computers are also necessary for interpreting data from a patient’s history and determining diagnosis. Moreover, computers make an important contribution to the education. They are widely used by school and university students and by students who study at home. Computers may be very helpful for learning most subjects. Some of those subjects are mathematics, languages, information technology that cannot be taught without computer, and so on. Computers are capable of storing and combining information in a way that makes is very simple to access and use. Computers simplify students studying by providing them with easy typing software, many useful exercises. In addition, they can make it easier for teachers to assess the students and mark their work. However, there are some features that cannot be taught by using computers. For example, it seems obvious that the subject like singing would be virtually impossible to learn without teacher’s involvement. Furthermore, while computers can be used by students for learning languages, they cannot provide them with an adequate feedback on their pronunciation or writing skills. Learning such subjects like chemistry and physics would be extremely difficult or sometimes even dangerous without teacher’s supervision while having done various experiments. In conclusion, it is important to point out that computers can be beneficial  for educational purposes and they can help students with learning most of the subjects. Despite this in some cases, it is also necessary to engage teacher to make the education more effective and complete. Teacher would also be helpful for pupils as he or she could answer their questions, provide them with a wide range of examples and give them more exercises on particular matters students have difficulties with.

Journey artical Article Example | Topics and Well Written Essays - 3500 words

Journey artical - Article Example as a company. It is an American multi-national communications company which is based in Illinois. It was known initially in 1928 as Galvin Manufacturing. By 1947, the company changed its name to Motorola though that name had been used as the company's trademark since the 1930’s. The company's first product was, at the time, radio car. Numerous Motorola’s products were radio-related, starting from battery eliminator for radios, and then to the world's first walkie-talkie. Nowadays, the company is known well for cellular phones of high quality and at the same time as the leading provider for the microprocessor which is used in Commodore Amiga, Apple Macintosh and Power Macintosh personal computers. It is at the same time offering different lines of communication products like satellite systems, digital cable boxes and modems (2007). China Laws Law in the People's Republic of China attracted very little attention a decade ago. But it is now attracting quite a good deal of attention from the business industry. Communicative interest on this subject are everywhere. Commercial services are even now keeping close tracks of Chinese legal developments, while publishing just about all foreign-related laws and regulations as they are being issued from Beijing together with English translations. There even exists a number of Chinese law discussion lists which can be found on the Internet, talking about broad policy issues and technical legal points which are the main topic of more and more spirited dealings by specialists around the world. (Corne, 1997) There are good explanations for this flourishing interest in Chinese law. Nowadays, foreign businesses that are involved in or thinking about doing business with China have an evident need to get a better understanding of the developing legal situation within which they will have to run. Foreign governments, in view of China's increasing value in the world trade and investment, are concerned with protecting th eir nations' interests by assuring the compatibility of China's legitimate scheme with those of the world's economy. For China itself, its "open door" policy of promoting foreign trade and foreign investment has been the booster of its economic improvement. It is at the same time the main motivational force behind its fast economic growth since 1978. Modification in foreign business laws has led into a broadening improvement of the entire legal system to meet the needs of a industry economy. Both its people and their leaders knows that continuing development in this aspect relies on the continuing efforts to take their legal system into agreement with world standards. (Robinson, 1995) China's legal regime for the approval and standard of foreign direct investment was an important focus of discussions. It is on this topic that the National People's Congress has been most productive in passing legislation. It is at the same time in this area that the laws passed have had such momentou s outcomes. China played its introductory law concerning foreign direct investment in 1979 which was known as the Equity Joint Venture Law. This activity authorized the creation, though was dependent to state approval, of joint Sino-foreign business undertakings. Participants in these ventures are liable for the firm's financial obligations, at the same time, entitling them to its profits to the point of capital that was brought in. They are approved to exist for up to 30 years and are accepted under Chinese law as legal persons. Equity joint ventures are ruled

Hedging Strategy Essay Example | Topics and Well Written Essays - 500 words

Hedging Strategy - Essay Example By considering the Treasury bond futures hedging strategy, he can minimise his risk as it is an effective instrument of risk control and can also enhance his returns. As Treasury bond futures cover up a broad range of maturities from the bonds of long term to short term notes, so it will help Clark to construct trades depending on the disparities in the movements of interest rates alongside the yield curve. There is negative connection between the fluctuations in interest rates and the bond prices. The increase in the interest rates is bad for bonds because when the rate of interest rises, the shareholders or investors in the bond fund prefer to liquidate or settle their shares. Due to this, the finance manager might be compelled to sell its bonds prematurely to raise sufficient cash in order to meet its requests of redemption. This could have a pessimistic effect on the regular price of bond fund (Forbes, 2013). Conversely, a fall in the interest rates results in the increase in the bond prices. This happens because, if rates of interest fall after the purchase of bond, the worth of bond will rise as investors will not be able to purchase a new bond with a high coupon rate. In this situation, the value of bond will be more than the actual value. Consequently, it will be traded at a premium (Bodie et al, 2009). Clark should consider the short term hedging strategy. Investment in the short term bonds is recommended because long term maturities bond would be hit tremendously when there is an increase in the rates of interest. Along with this, he should consider the individual bonds but require being cautious with the issuer’s credit quality. Clark also needs to be sure that the company is monetarily strong and proficient to repay his principle on the maturity of bond. A short term bond is suggested because this will facilitate Clark not to become locked in a low interest rate for an extended period (Forbes, 2013). The reason behind suggesting the

Case Study Analysis Assignment Example | Topics and Well Written Essays - 1000 words

Case Study Analysis - Assignment Example of the greatest ironies surrounding the release of the drug into the public domain was that some of the major personnel in FDA such as Merk were aware of the possible threats that were associated with the use of the drug were quite adamant to make it known (Richwine, 2004, November 18). They knew the drug increased risks of heart attack that made it pose as a great threat to public use. However, Charles Grassley one of the primary leaders in FDA initiated research to investigate the risks associated with the use of Rofecobix drug (Topol, 2004). In the course of this research, Dr. David Graham an FDA reviewer discovered the risks associated with the use of the drug, and made a publication without obtaining any clearance from the FDA committee (PhamaLot, 2011, August 28). The primary leadership of FDA has a number of shortcomings most of which contributed to the clearing the drug for public use. The chairperson of the FDA committee Charles Grassley equally raised concern that the relationship that existed between the drug companies and FDA was cozy and, therefore, could not provide room for the establishment of proper control over the drugs cleared (Topol, 2004). Some committee members have also been faulted for knowingly allowing the clearance of the drug and not warning people of the impending risks associated with the use of rofecobix. In addition, when David Graham published his findings, he was faulted by the acting commissioner of FDA, Lester Crawford, stating that Graham did not follow the correct procedures in making publication of his findings report (Richwine, 2004, November 18). Grassley, on the other hand, is on the opinion that Lester Crawford wanted to intimidate, Graham the reviewer and, therefore, his statements were purely meant to i ntimidate the witness before hearing (PhamaLot, 2011, August 28). The above crisis represents a management dilemma, which results into confusion and inconsistency in the nature of research provided. The primary leaders

The Inadequacy of US Counterinsurgency in Afghanistan Literature review

The Inadequacy of US Counterinsurgency in Afghanistan - Literature review Example 1). This research work aims at assessing the effectiveness of the counterinsurgency measures adopted by the U.S. in Afghanistan. Background of the Problem The principal argument of this study is that the US should deploy its resources in a manner that promote capabilities, which improve the competence of the Afghan government and its security forces, in conducting counterinsurgency operations. There have been several instances, wherein the US forces have enraged the Afghan villagers. This has been attributed to the ignorance among these soldiers, regarding the cultural and social traditions of the Afghans. It has been suggested that the US forces should abstain from interacting with the people and permit the Afghan authorities to take the necessary steps (Jones, 2008, p. 93). A major feature of counterinsurgency (COIN) warfare is the battle to win over the hearts and minds of the target population. This has been attempted even with the most seemingly isolated members of the populatio n, in remote villages and rural regions. For this purpose shortwave radio has been employed. This initiative would further alienate the Afghans towards the Karzai government, which is detested in the extreme; local politicians; governors; tribal chiefs; warlords and militia commanders, who are supporters of the highly unpopular Karzai administration (Kilcullen, 2009, pp. 50 – 51). Assistance has been scanty if not totally absent, in the rural areas. These areas had been at the greatest risk from the Taliban, and had been totally dissatisfied with the almost non – existent change. The fate of counterinsurgency in Afghanistan will be determined by what happens in rural Afghanistan. The developments in the urban regions will have little if any bearing on the success of failure of counterinsurgency (Jones, 2008, p. 4). Consequently, counterinsurgency has to reach such people. Rationale How effective was the U.S. Counterinsurgency in Afghanistan? I have examined the relevan t literature pertaining to the present topic, by eminent scholars, like Jones, Kilcullen, Ganesh Sitaraman, Mark, Johnson, Schreer, for answering the question. I have examined strategies, such as the traditional social hierarchies and the different forms of legitimacy, local, specialised knowledge trumps doctrine and theory. I have obtained information regarding the actual state of affairs with regard to fair elections, rule of law, and economic development in Afghanistan. The opinion of the authorities in this area, has contributed to the assessment of the situation. Issues, such as the exercise of power by the government, harmonisation of development, governance and security were provided by Mark. Positive elements in the extant literature, with respect to counterinsurgency are the unbiased opinion of eminent scholars and the provision of the true picture regarding the present situation, regarding the governance of Afghanistan. I will further investigate these issues, after applyi ng the relevant theories and strategies, pertaining to the counterinsurgency measures. As such, I can expand my research on the issues discussed in the literature, and arrive at better conclusions regarding the current problem. Hypothesis The counterinsurgency measures adopted by the US in Afghanistan have proved to be inadequate. This synopsis of insurgency in Afghanistan, brings to the fore the factors that had ensured the success of insurgencies in the past; external support, variations in the quality of the security forces, and challenges to governance. Research Questions What is insurgence?

Case 1 Study Example | Topics and Well Written Essays - 250 words - 2

1 - Case Study Example is accident, Bertha as an employee of The Happy hour sports bar is liable and needs to compensate the young man for injury caused (Duplessis, Enman & O’Bryne, 2010). However, Bertha as the defendant in this litigation can defend her actions on the basis of duty of care and the young being incapacitated to making an informed decision at the time. As an employee at the bar, Bertha owed duty of care to her employees and this is evidenced in her refusal to sell the young man a beer since he was already drunk. The man having come back again after being thrown out the first time; was reason enough to believe that his reasoning was compromised. The young man even attempted to assault Bertha but she handled him and gave him a â€Å"heavy† push that led to his head injury. The heavy push needs to be described and will serve as a basis in which a decision will be made. It has to be ascertained if Bertha pushed the young man with an intention of hurting him or it was a mere accident. The decision of the court would be based on the motive of the â€Å"heavy push† which with enough evidence would lead to the bar owner compensating the young man for injuries. However, if the â€Å"heavy† push is disapproved by the court, Bertha will have no case to answer since the young man’s mental capacity was compromised and as an employee, Bertha owed the young man duty of care hence did not sell him a beer. His injury was merely an unforeseen circumstance (Duplessis, Enman & O’Bryne,

Researching a decay (1990's movies) Essay Example | Topics and Well Written Essays - 500 words

Researching a decay (1990's movies) - Essay Example As pointed out, the popular culture during 1990s was entirely different from the past decade because the unexpected end of Cold War, the collapse of Soviet Union and the collapse of Berlin wall deeply influence the political/cultural scenario of the world. To be specific, the wartime sentiment and nationalistic mood transformed into cultural amalgamation and acceptance. But Chris states that â€Å"The accelerating integration of information and entertainment media meant that movies and television shows had become news themselves† (139). The popular culture reflects the aspirations and feelings of the mass and acts as a safety valve which reflects the cultural characteristics of a society. Within this context, the popular culture during 1990s set itself free from political stance and transformed into multiculturalism. In short, popular culture during 1990s reflected the change in international politics and reflected the same within culture. The most important characteristic of movies during 1990s was hyperrealism. Within this context, the main characteristics of hyperrealism can be broadly classified into three: intervention, identity, and space and time. Hyperrealism in 1990s can be simply defined as the dilemma which leads to virtual real illusion. To be specific, the films in 1990s are interconnected with hyperrealism. Martin opines that â€Å"The use of terms such as ‘simulation’, virtual reality’ and ‘hyperrealism’ in the criticism of news media is often confused and imprecise† (141). The individual (say, the hero) who is able to experience hyperrealism can act the role of a channel between virtual and real worlds. This is the most important characteristic of hyperrealism, which influenced the scenario of cinema in 1990s. The other characteristics of hyperrealism in 1990s include: Within this context, the film The Matrix (1999) is one of the best examples of hyperrealism

The Ancient Art Analysis Essay Example | Topics and Well Written Essays - 500 words

The Ancient Art Analysis - Essay Example The Indra and Surya are engravings as depicted in this picture. Nonetheless, the two sculptures are a depiction of the final existence and the past lives the Buddhism founder, Siddhartha Gautama. The size of the sculptures is also similar as it ranges from 50 to 200 feet in height. The four-ram Fangzum is a bronze cast sculpture while the Reliquary Buddhist Stupa is cast in gold. The two sculptures have a great significance in the culture of the Chinese and the Indians respectively. These two sculptures depict the respect given to the dead, and especially to sages and religious teachers. However, there is a great difference in the age of their molding with the four-ram fan zun cast in the second Millennium BCE, during the era of the Shang dynasty with the Reliquary Buddhist Stupa cast in the 3rd century CE, which was during the Kushan dynasty. The two sculptures are also a symbol of commemorating significant occurrences in the Chinese and Indian religion. Hence, their main subject or significance is more of spiritual beliefs than political. Their complexity and evident in the way that the bronze is carved into the four-ram Fangzum and the way the pillars erect the Reliquary Buddhist Stupa. This artistic feature is a clear evidence of the prowess and the passion of Chinese and Ancient Indian sculptures of the time. The sculptures also have a gloss finish that clearly distinguishes them from the past sculptures that had a dull finish. The bowl is red and made of earth. The bowl also has designs  of a human head that are  black  in  color  and  imposing  fish designs. The bowl was made for worshiping the ancestors in Ancient China during the Neolithic Period, which was crucial in the Chinese history. Despite the non-development of the potter’s wheel during the time of making the bowl, the bowl is perfectly round with highly polished surfaces. In

What are the differences between managing people in a small marketing Essay

What are the differences between managing people in a small marketing consultancy and in a family run shoe factory - Essay Example But, the crucial fact is, most of the organization will be managed differently, based on the characteristics of the workers who work in it, among other reasons. Likewise, there is a difference between managing people in a small marketing consultancy and in a family run shoe factory. Firstly, inside a family run shoe factory, there will be an inbuilt or rooted organizational culture, built by the founder or the leader. That is, in any organization, the workers like the five different fingers in one’s hand, will be different from one another, as they will come from different backgrounds. The unison of these different humans under a single organization to reach a target is, and will always be a difficult proposition. As these different humans could only create a different working culture, the success rate will be minimal. Inside the shoe factory, this organizational culture could be easily established because being a family run factory, the founder or owner would have recruited or posted his/her family members from the same background in important positions. Also, as there will a close relationship between the employees, it will reflect in the work. Another vital element is, culture â€Å"coevolves† with the organization, when it achieves success (Sc hein). So, managing them will be an easy affair because of the presence of a common organizational culture. But, in the case of the marketing consultancy, the workers could be from different background having different educational qualifications, ethnicity, etc, etc. In those environments, the workers will only exhibit different mindset, and so formation of a common organizational culture is a difficult task or it will take time. So, managing a small marketing consultancy firm with different workers would also be a difficult task. Inside the family run shoe factory, on the flip side, even if the workers are found to be inept, they will not be fired easily. That is, when the employee becomes too lazy, self-seeking,

Mergers and Acquisition Essay Example for Free

Mergers and Acquisition Essay Why are there mergers and acquisitions? Mergers and acquisitions take place for a number of reasons, such as refinancing for a better price, amplifying expansion, and submerging risk through diversification. New entities may drag behind after a merger takes place due to the higher cost of matching different and unconnected economic activities. Diversification by business groups may also reduce technical effectiveness. When a merger takes place, a bigger business groups emerges from the two which usually will have more economic and political influence In this paper, we will assess the impact of mergers and acquisitions on firms, including sensible and dubious reasons for, and benefits and costs of, cash and stock transactions. We will also be sure to examine the financial risks of merging with or acquiring an organization in another country and how those risks could be mitigated. First we will we will assess the impact of mergers and acquisitions on firms while also touching on the benefits and costs of, cash and stock transactions. Who gains from mergers? Typically, the selling firm tends to be impacted favorably by the merge and/or acquisition rather than the firm acquiring the selling firm. Studies demonstrate that most of the benefits from mergers and acquisitions were earned by the selling firm, not the acquiring company. For example, recent research found that holders in the acquiring firm earned an estimated 4% return on their investment with the completed acquisition in contrast to the holders of the target firm whom typically received a 30% return on their investment. So, to imply that mergers and acquisitions do not create benefits would not be correct because the acquiring firms are paying too much money for their acquisitions. There are many sensible and dubious reasons for mergers and acquisitions. Many times the reason for acquisitions is for expansion. Expansion that is not limited by internal resources means there is no reduction of working capital which crates many benefits such as; stocks can be exchanged faster, assets can be purchased more quickly rather than building, better technology can be gained as well as resources and skills, and the tax benefits can sometimes give the new company better operating leverage in their particular market. Smaller firms will usually always gain from merging with larger firms because larger firms have better equipment, resources, and technology. The aforementioned reasons make the merged firms more effective in daily operations, which in turn, make the merged firms more alluring to their current and potential clients. Mergers and acquisitions also help reduce the merged firms risk by diffusing their debt and risk among the various companies with the firm. Oftentimes firms will merge in order to gain a larger market share within their perspective fields. For example, ATT recently merged with Cingular Wireless to become the nations largest telephone network and gain the highest market share of customers in telecommunications, thus trying to eliminate competition. Now, we will discuss the financial risks of merging with or acquiring companies in another country. There are many financial risks of merging or acquiring companies in another country. One, oftentimes there are culture clashes between the foreign firm and the home firm. These cultural clashes sometimes lead to losing valuable managers and workers to other firms because they do not desire to live in another country. Two, there may be a conflict of intentions in two different countries which could spell disaster for all firms involved. Other financial risks can include; foreign exchange rates, lawyer, banker, and brokers fees. Firms must know foreign banking and business laws such as the proper filings they must report with the SEC and foreign officials. Many consideration must be taken when considering merging /and or acquiring a foreign firm. In this paper, we assessed the impact of mergers and acquisitions on firms which we found to be more beneficial to the smaller of the merging firms due to their gaining of better equipment and resources. We found that there are indeed many sensible and dubious reasons for, and benefits and costs of, cash and stock transactions which include risk diversification among the merged firms. We examined the financial risks of merging with or acquiring an organization in another country and conclude that mitigation can be done by ensuring that the proper laws and culture differences are overcome before merging. References Brealey, R., Myers, S., Marcus, A. (2004). Fundamentals of Corporate Finance. Chapter 22: Mergers, Acquisitions, and Corporate Control. Retrieved from the internet on April 22, 2007 from https://ecampus.phoenix.edu/content/eBookLibrary/content/eReader.h#Investopedia.com.(2007). Retrieved from the internet on April 22, 2007 from www.investopedia.com/university/mergers/mergers4.asp 36k

Effects of Depression on Brain Function

Effects of Depression on Brain Function Depression The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnose children and adolescents with major depression with signs that include loss of interest and sadness for two weeks straight. Psychologists usually will also look for at least five more symptoms on top of the other two symptoms. These include â€Å"changes in sleeping or eating habits (weight and energy), psychomotor agitation or retardation, feelings of worthlessness and guilt, trouble thinking or paying attention, recurrent thoughts of death, or suicidal ideation and attempts† (Bujoreanu, Benhayon, and Szigethy, 2011, p. 548). This paper will focus on comparison of normal brain function and the brain function of an individual with depression, negative effects of daily functioning living with depression, assessments that are used for diagnoses and treatment, and appropriate treatment options and coping mechanism for individuals with depression. Comparison between Normal Brain Function and Depressed Brain Function Neuropsychological research has shown that emotion is controlled by the right cerebrum which means that the â€Å"right-posterior region of the cerebrum is specialized for the perception of emotional information, regardless of valence† (Shenal, Harrison, Demaree, 2003, p. 34). In normal brain functioning, the right cerebrum also controls arousal and attention. Other research has shown that there is a balance of positive and negative emotions between the left and right cerebrum. The left cerebrum processes positive emotions while the right cerebrum processes negative emotions (Shenal et al., 2003). EEG asymmetries have been examined with individuals that have depression and have found there is an increased activation in the right-frontal lobe that is relative to left-hemisphere activation (Shenal et al., 2003). Other studies have shown individuals with depression have different hemisphere activation by increased right-hemisphere activation or decreased left-hemisphere activation. Individuals with depression from left-frontal dysfunction will have problems planning and arranging information. Depression from right-frontal dysfunction may have impaired nonverbal fluency. Negative Effects of Daily Functioning Living with Depression Major depression can have a big effect on children or adolescent’s ability to function on a day to day manner. There are a lot of negative effects to depression that are important to recognize right away for help. Some of the effects of depression include â€Å"change of eating habits, change in sleeping habits (sleeping too much, not sleeping very much), irritability, social withdrawal, trouble paying attention, and feelings of sadness† (Bujoreanu et al., 2011, p. 548). If depression is not treated, this can lead to â€Å"family dysfunction, academic impairment, and psychosocial difficulties† (Bujoreanu et al., 2011, p. 548). There is also the chance that the depression can continue into adulthood if the family is not aware or informed of the symptoms the child is displaying. Assessments that are Used for Diagnoses and Treatment Neuropsychologists are now starting to find new ways to accurately diagnose depression in individuals as well as finding out if depression treatments are actually helping individuals with the disorder. Depression is now being diagnosed by a blood test and neuroimaging (fMRI) is being used to examine neural circuitry in adolescents with depression. The blood test is a new technique to psychiatry that was approved in 2011. This diagnostic tool is one way to find out if an individual has major depressive disorder without the medical professional being biased or not able to get a lot of information from the individual. The diagnostic tool looks at the levels of ethanolamine phosphate in the patient’s blood to give an indication that the patient has the disorder. Studies have shown that people with depression have low levels of ethanolamine phosphate (Verma, Kaur, David, 2012). At this point, the blood test is very expensive or is slow to get the results back to see if an individual has depression. Neuropsychologists as well as health physicians can use this assessment as the first step in determining if the patient has major depressive disorder. Once the blood tests indicate the disorder, the neuropsychologist and health professional can refer the patient to a medical professional that specializes in depression. The blood test can be used to help the medical professionals in making a diagnosis and to find the best treatment for the patient (Verma et al., 2012). The second assessment that is being used by neuropsychologist for depression is neuroimaging (fMRI). One study in particular used an fMRI to compare adolescents with depression and healthy adolescents on â€Å"neural responses to fearful facial expressions† before treatment (Cullen, 2012, p. 348). The study was repeated again after eight weeks with the depressed adolescents on fluxetine (antidepressant). Research showed that adolescents with depression increase the activation in the amygdala looking at fearful faces (Cullen, 2012). After the treatment, there was no difference between adolescents with depression and healthy adolescents. This study has opened new doors to further study other depression treatments. The fMRI was able to show the difference the fluxetine had on the brain to help adolescents with negative effectives that interfere with daily living. The next steps would need to look at what can affect before and after treatment findings. Some of these include â€Å"age at assessment, illness status, treatment history, and type of treatment† (Cullen, 2012, p. 350). When these effects are looked at with more research, this will bring clinical advancements to the neuropsychological field. Appropriate Treatment Options When it comes to appropriate treatment options for children and adolescents with depression, there are two different kinds that have been the most effective. These two different kinds of treatments are psychotherapeutic treatments and psychopharmacological treatments. The psychotherapeutic treatments are therapy treatments to work with children and adolescents to help them function normally in their daily lives. Evidence-based treatments (EBT) are â€Å"interventions or techniques that have produced therapeutic change in controlled trials† (Bujoreanu et al., 2011, p. 549). Common evidence-based treatments used with depressed children and adolescents include cognitive-behavioral therapy (CBT) and interpersonal therapy-adolescent (IPT-A). Cognitive-behavioral therapy has been found out to be the most effective psychotherapeutic treatment with children and adolescents with depression. Aaron Beck created cognitive-behavioral therapy and focused on how â€Å"thoughts, feelings, and behaviors are inter-related and individuals can make positive changes in how someone feels by changing what they do or think† (Bujoreanu et al., 2011, p. 549). Children and adolescents work with a therapist to learn new skills and explore different ideas that are discussed during sessions. Interpersonal Therapy-Adolescent (IPT-A) is a treatment that does takes place for a short period of time. The therapy focuses on the clients’ depressive symptoms and the interpersonal context in which they occur (Bujoreanu et al., 2011, p. 550). To help with the depressive symptoms when they occur, the therapist helps the child or adolescent learn problem-solving and communication skills. Psychopharmacological treatments involve the medications that are appropriate for children and adolescents with depression. These include selective serotonin reuptake inhibitors (SSRIs), norepinephrine-dopamine reupatake inhibitor (NDRI), and serotonin-norepinephrine reuptake inhibitor (SNRI). SSRIs are the most common and first kind of drugs that will be used to treat child and adolescent depression. Fluoxetine and escitalopram are FDA approved for children with depression, but there are also other medications that are not intended for depression that have been successful (Bujoreanu et al., 2011). When picking an SSRI, it is important to look at family history and how the drug affects the child or adolescent. When SSRI’s do not work with the children and adolescents, there are other drugs that can be taken into consideration. Adolescents that have depression with bupropion would use a NDRI to help with the symptoms. Another drug category that can help with depression is SNRIs that include taking duloxetine and venlafaxine that are sedating. When one kind of treatment does not fully treat the patient, combined therapy of medication and therapy are used. Therapy is usually the first step taken in treatment before medication is considered. Alternative Treatments There are a lot of adolescents that are experiencing depression symptoms that are not able to receive the standard treatments. This can be from the adolescent’s family not having insurance or the families insurance does not cover certain treatment options. These alternative treatments that could help these individuals with depression include interpersonal therapy and attachment-based family therapy, the artistically creative approaches, and existential therapy (McGlasson, 2012). The interpersonal therapy focuses on the different relationships that are in the adolescent’s life. If there is not a healthy relationship, this can lead to depression. This therapy focuses on personal issues that cause the different relationships to not be healthy and finds skills the adolescent can work on to improve those relationships. The attachment-based family therapy is where the family, the adolescent, and a trained counselor work together to build a healthy relationship. This also includes skills that that will be learned in sessions that will help in the long run (McGlasson, 2012). The artistically creative approaches include art therapy and music to help adolescents express themselves in a creative way. Art therapy allows the youth to communicate on a deeper level than just talking about the issues with a counselor. This form of therapy might feel less threatening to the adolescent and a way they can control (McGlasson, 2012). Music is something that adolescents are familiar with and feel safe with being used in therapy. Music lowers stress and can help the therapist in understanding different moods that the client is experiencing (McGlasson, 2012, p. 19). Existential therapy has four themes to the treatment. These themes are â€Å"the uniqueness and freedom of the individual, the recognition of suffering as part of the human experience, an emphasis on the here-and-now to discover one’s meaning and identity, and a commitment to discover and develop one’s talent† (McGlasson, 2012, p. 19). The themes all focus on the individual and how he or she is becoming. Therapists would focus on existential concerns that go on in the adolescent’s life and find ways to explore the issues. Coping Mechanism for Individuals with Depression There are healthy and unhealthy coping strategies that children and adolescents do to deal with depression. The healthy and unhealthy coping strategies both involve the same three core categories (emotion-focused coping, problem-focused coping, and avoidant coping). It all depends on what the children and adolescents have picked up from others and what they have learned on their own to determine if it is healthy or unhealthy. Unhealthy coping strategies usually fall under the emotion-focused coping and avoidant coping. Emotion-focused coping is â€Å"any response aimed at reducing or managing the negative feelings that arise in response to the threat or loss† (Hayat, 2013, p. 153). Research has shown that common emotion-focused coping strategies that can develop depression and suicidal ideation more are self blame and emotional support (Horwitz, Hill, King, 2011). Avoidant coping involves a strategy that avoids the depression symptoms and suicidal ideation. Common avoidant coping strategies that are unhealthy and can develop the disorder more are behavioral disengagement and denial (Horwitz et al., 2011). Avoidant coping is usually avoided when learning new strategies that can help with depression. When children and adolescents learn healthy ways to cope with depression, most of the strategies fall under the category problem-focused coping. This category of coping strategies is defined as â€Å"attempting to deal constructively with the stressor or circumstances itself† (Hayat, 2013, p. 153). A medical professional can help the child or adolescent learn active coping strategies, plan different coping strategies that fit with the stressor or circumstance, and use instrumental support (Horwitz et al., 2011). For emotion-focused coping healthy alternatives would learning wishful thinking and seeking emotional support from family and friends that will not make the individual feel worse about themselves. These coping strategies can be learned by a medical professional that can work with the child or adolescent with depression. While there was only a few coping strategies mentioned, other coping strategies might be used depending on the situation of the individual. Preventive Measures for Individuals at Risk of Depression It is important that society is aware of what factors will identify high-risk adolescents for depression. When factors that can lead to depression are understood, steps can be taken to help reduce the risk of the disorder developing. At this point, research has shown that biological, psychological and social risk factors can trigger depression. Newer research has also found that neuroticism (N) (personality trait) is associated with mood disorders that can risk adolescents is developing depression (Kuyken, Watkins, Holden, Cook, 2006). High neuroticism individuals will show more mood changes and will need to respond adaptively (Kuyken et al., 2006). Kuyken’s et al., (2006) study included four different hypotheses to find out what risk factors would determine if adolescents will develop depression. They hypotheses are (1) â€Å"Adolescents at risk for depression (as indicated by high N) will report greater rumination than adolescents at low risk but lower rumination than currently depressed adolescents, (2) among currently depressed adolescents, elevated levels of rumination will be associated with higher levels of depressive symptoms, (3) the relationship between N and depressive symptoms will be partially mediated by rumination in cross-sectional analyses, with higher rumination associated with more depressive symptoms, and (4) the effect of rumination on depression will be moderated by gender, being greater for female compared to male adolescents† (Kuyken, et al., 2006, p. 42). The results indicated that at risk adolescents for depression have more ruminated than healthy adolescents. At risk adolescents and current depressed adolescents were comparable with high neuroticism personal trait. Adolescents that found out they had depression show rumination was connected to severe depressive symptoms. This study found that rumination and depression symptoms were the same for females and males. Conclusion Depression is a complex disorder that is now fully starting to be understood. Neuropsychologists are able to see what parts of the brain are impaired from the disorder as well as assessments that help to diagnose and treat depression accurately. With this information medical professionals find the best treatment options for the individual and help with coping strategies that are not unhealthy to use. This information has also made it easier to determine if adolescents are at risk of developing the disorder. Determining if adolescents have depression is still new, but with more research, medical professionals will hopefully be able to reduce the amount of youth with the disorder. References Bujoreanu, S., Benhayon, D., Szigethy, E. (2011). Treatment of depression in children and adolescents. Pediatric Annals, 40(11), 548. doi:10.3928/00904481-20111007-05 Cullen, K. R. (2012). Imaging adolescent depression treatment. The American Journal of Psychiatry, 169(4), 348. Hayat, I. (2013). Stressful life events, depression and coping strategies. Journal of Research in Social Sciences, 1(2), 148. Horwitz, A. G., Hill, R. M., King, C. A. (2011). Specific coping behaviors in relation to adolescent depression and suicidal ideation. Journal of Adolescence, 34(5), 1077-1085. doi:10.1016/j.adolescence.2010.10.004 Kuyken, W., Watkins, E., Holden, E., Cook, W. (2006). Rumination in adolescents at risk for depression. Journal of Affective Disorders, 96(1), 39-47. doi:10.1016/j.jad.2006.05.017 McGlasson, T. D. (2012). Listening clearly: Alternative treatments for adolescent depression. The Prevention Researcher, 19(4), 18. Shenal, B. V., Harrison, D. W., Demaree, H. A. (2003). The neuropsychology of depression: A literature review and preliminary model. Neuropsychology Review, 13(1), 33-42. doi:10.1023/A:1022300622902 Verma, R. K., Kaur, S., David, S. R. (2012). An instant diagnosis for depression by blood test. Journal of Clinical and Diagnostic Research : JCDR, 6(9), 1612. doi:10.7860/JCDR/2012/4758.2579

The Awakening and A Dolls House | Analysis

The Awakening and A Dolls House | Analysis Everyone if faced with making decisions in their life. In the Awakening by Kate Chopin, and A Dolls house, by Henrick Ibsen, it is evident to the reader that the decisions made by the two characters, Edna and Nora, are made by the way they view themselves. More or less by the end of each story self perception is what leads both protagonist characters to make a life changing or even life ending decision. Throughout the story Edna takes many risks. While at grand Isle, she risks the dangers of the sea so that she might learn to swim. Furthermore, Edna risks impropriety by spending so much time alone with Robert. Upon returning home, Edna continues to be the risk taker. One must ask himself, however, what exactly is Edna risking with her, at times, juvenile behavior? In truth, she is risking nothing more than humiliation. Edna knows that her husband will never leave her nor will he allow her to leave him. While Edna may be considered a risk taker, it is easy to see that the risk Nora, in A Dolls House takes far greater risks. While it is clear that Noras husband does not see her as a person with a mind for anything beyond decoration, the reader quickly sees that Nora knows far more than maybe she should know. Torvald constantly shows his superiority over his wife with the use of pet names such as: my little dove or chipmunk. Torvald views Nora as one might view a pet, cute and fun to play with as long as shes obedient. Just as Edna in The Awakening, Nora is a risk taker. In the beginning, the reader sees a juvenile rebellion on Noras part. However, the reader laughs along with Nora as she enjoys the forbidden macaroon. This rebellious secret of Noras proves to be just the tip of the iceberg. The iceberg itself comes in the form of Kronstad, a banker. The reader learns of Noras secret shortly after his appearance. It appears that Nora has borrowed money in her fathers name that Torvald is not aware of. At the time this story is set, it is unheard of that women should handle any money in this manner without her husbands knowledge. What is Nora risking in keeping his to herself? In essence, she is risking everything: her familys financial security, her security, and imprisonment. Also like Edna, Nora is not the mother-type. Nora treats her children as Torvald treat heras playthings. Nora is on the outside very flighty and unconventional, and on the inside she is thrilled at what she thinks of as the successful deception of her husband Torvald. Clearly that which she views as a success now, will later be viewed as a failure. The difference being with Edna and Nora, is that Nora doesnt want or need her husbands forgiveness. While the female protagonists in Chopins The Awakening and Isbens A Dolls House share many similarities of situation, it is the image of self that sets them apart. Both Edna and Nora prove throughout their respective stories to be risk takers. It is Nora who in the end takes the ultimate riskthe risk to live alone. Edna, however, in the end remains trapped by society and her circumstance. Rather than spend the rest of her life in that trap she chooses death. Death has many meanings, of which Chopin and Isben have explored two. Chopin chooses an irony filled death for Edna. Ednas death is ironic in that the ocean, a tool for her awakening, becomes the tool of her death. In Isbens story, while Noras death is not literal, it is a death to all that she has known thus far. Given the choices that each character has made leads one to believe that Noras death was ultimately a far more painful death than that of Edna.

Savant Syndrome Essay -- Health, Diseases, Splinter Skills,

Savant Syndrome is an extremely rare condition in which a person with a severe mental handicap has extraordinary abilities in a certain area, such as memorization, mathematics, or the playing of instruments. The first known case of savant syndrome was documented in a German scientific journal, Gnothi Sauton, in 1783. This article described the case of a man named Jedediah Buxton, who was talented in memorization and mathematics (Treffert 2009). Ever since this first account of Savant Syndrome was recorded, scientists and physicians alike have tried to understand this unusual disorder. The most well known case of Savant Syndrome is the fictional character; however, Raymond Babbitt, played by Dustin Hoffman in the 1988 movie Rain Man, was inspired by a real person. The now fifty-seven year old has memorized over six-thousand books and has an encyclopedic knowledge of over fourteen subjects, including geography, history, literature, and sports. He can name all the US area codes and the zip codes of major US cities, has memorized the maps in the front of the telephone books and can tell you exactly how to get from one city to another has calendar-calculating abilities and is a rather advanced musician (Treffert 2009). This man, however, cannot comprehend simple tasks and cannot even dress himself. One of the earliest reports of Savant Syndrome is that of the amazing calculating ability of Thomas Fuller. Thomas â€Å"who could comprehend scarcely anything, either theoretical or practical, more complex than counting† was asked how many seconds a man who wa s seventy years, seventeen days, and twelve hours old and replied the correct number of 2210500800 in less than ninety seconds. He even accounted for the seventeen leap year... ...hat causes autism by labeling autism a â€Å"signal-processing† disorder with information reduction through compression (Fabricius 2010). Basically, compression is where the brain takes an image and remembers the basics of the image but not the fine details. Fabricius explained Savant Syndrome using the compression theory: that normal people work with a compressed image while Savants retain one hundred percent of the original details. This is known as the â€Å"Savant Hypothesis (Fabricius 2010).† For cognitively normal individuals, fine details are often lost in a process known as â€Å"prototyping.† When a cognitively normal individual sees an image, unimportant details-like, in Fabricius’ example, an embedded triangle- are lost. To the autistic Savant, those details stand out, and the Savant has trouble seeing the big picture. Below is the example from Fabricius’ work:

History of Anesthesia Essay -- Biology Medicine

  Ã‚  Ã‚  Ã‚  Ã‚  I will be telling you my short little paper on the History of Anesthesia. I will be telling what some terms mean that will be used in anesthesia history. Also I will be telling a some dates from years before our time on how anesthesia came from and who was there, and what drugs came out.   Ã‚  Ã‚  Ã‚  Ã‚  First I will be starting out with several definition of the term anesthesia. The absence of normal sensitiation, especially to pain, as induced by an anesthetic substance or by hypnosis or as occurs with traumatic or pathophysiologic damage to nerve tissue. Anesthesia induced for medical or surgical purposes may be topical, local, regional, or general and is named for the anesthetic agent used, the method of the procedure followed, or the area or organ anesthetized. The people who are permitted to give anesthesia to a patient is an anesthesiologist or a Certified Registered Nurse Anesthetist (CRNA). (Mosby’s Pocket Dictionary of Medicine, Nursing, and Allied Health) There is also two different ways of describing Anesthesia you could either call it anesthesia or analgesic. In the next couple paragraphs I will be going over ways on how anesthesia would be given to a patient who will be going under a surgery.   Ã‚  Ã‚  Ã‚  Ã‚  General anesthesia is the most common way that anesthesia is given to a patient. The absence of sensation and consciousness as induced by various anesthetic agents, given by inhalation or intravenous injection. Most of the time a general anesthesia is given to the patient through an IV to the patient.   Ã‚  Ã‚  Ã‚  Ã‚  Local anesthesia is another common way of inducing a patient. The administration of a local anesthetic agent into tissues to induce the absence of sensation in a small area of the body. Topical anesthesia is a surface analgesia produced by application of a topical anesthetic in the form of a solution, gel, or ointment to the skin, mucous membrane, or cornea. Regional anesthesia is an anesthesia of an area of the body by injecting a local anesthetic to block a group of sensory nerve fibers. Next one would be a caudal anesthesia which would an injection of an agent into the caudal part of the epidural space through the sacral hiatus to anesthetize sacral and lower lumbar nerve roots. An epidural anesthesia is an injection A type of regional block in which a local  Ã‚  Ã‚  Ã‚  Ã‚  anesthetic is injected into the epidural... ...imetry added to the standards for basic monitoring when it comes to an anesthestized patient. 1992 Desflurane was finally made that it could be used clinically. Desflurane is one the anesthesia drugs that must be heated because it is unsable in room temperature. 1994 Sevoflurane also was passed to be used in a clinically stable medical field. 1995 House of Delegates of the ASA approves Practice Guidelines for Preoperative Transesphageal Echocardiography. 1996 End trial carbon dioxide monitoring added to the standards for basic monitoring. End trial carbon dioxide can also be used as EtCO2. Also in this year the Bispectral Index Monitoring System approved for Clinical use. House of the ASA approves Practice Guidelines for Office Based Anesthesia. Last thing in this year Rapacuronium used clinically and it is also always known as a IV drug. WORK CITIED The American Heritage Dictionary of the English Language, 3rd. Edition. 21 November 1846 Longnecker, David E., Murphy, Frank L. Introduction to Anesthesia. Copyright 1997 Dorsch, Jerry A., Susan E. Understanding Anesthesia Equipment Construction, Care, and Complications (3rd. Edition). Copyright 1993

Essay on Identity in Huckleberry Finn -- Adventures Huckleberry Huck F

The Development of Identity in Huckleberry Finn In the novel The Adventures of Huckleberry , by Mark Twain, the main character enters into a transitional period of his life. This character, Huck Finn, faces many situations in which he is forced to deal with decisions that foster with in them the ability to bring about change. Since transition is the process of entering change, Huck is searching for an identity which is truly his own. In determining his self image, Huck deals with conformity and freedom, trying on different identities that do not belong to him, and enveloping and shaping these new found attributes into an identity which best suits his "deformed conscience." The Adventures of Huckleberry Finn begins with Huck under the care of Widow Douglas. Since Huck is so used to being unencumbered, "He sees the widow Douglas' protection solely in terms of confinement"(WHIT 156). This is unacceptable to Huck because he, "loses his freedom amid 'the bars and shackles of civilization"(WHIT 156). According to Susan Harris, "the sensory world exists beyond the narrow conventions of the human community and it is the place for the regeneration of the soul"(78). To put it in simpler terms Huck belongs out under the stars where he will not be bound by the community. The next impedance in which Huck is faced with is the untimely return of his drunkard father. His father was merely stopping through to steal money from his son. So since he did not care for his son much, Pap did not feel the least bit inclined to treat his son with any respect. So Huck once again faces confinement, except this time it is in a log cabin. This time, "the only release is escape, flight and effacement of the identity through which bot... ...s own, and enveloping and forming these new found attributes in to a an identity which best suits his "deformed conscience." III Body Huck versus Conformity-Freedom * 1.Huck's stay with Widow Douglas * 2.The flight from Pap * 3.The Raft Trying on Different Identities * 1.Huck's "Death" * 2.The beginning of Huck's quest for himself * 3.Other examples of characters from the novel Deformed Conscience(Good vs. Bad) * 1.Huck's religion * 2.Huck and Jim * 3.Huck needs a family IV Conclusion Huck encounters various situations in which he learns to adapt and react to each situation in a way he feels suitable. Through these experiences Huck learns and overcomes boundaries. Huck combines his learned knowledge into an identity which suits him and thus creates a conscience with which he is comfortable.

Dbq: French and Indian War

DBQ the French and Indian War The French and Indian War is known as an unintentional war sparked by a young George Washington’s actions towards the French ambassador. Both the English and French wanted to obtain control of the Ohio Valley. Each group desired to show their superiority and gain the benefits of the new world. The English and French could not solve their disagreement peacefully, and war was inevitable. The war not only changed the new world forever, but also, Britains relationship between its American colonies.The relationship between Britain and its American colonies was transformed through the political, economic, and ideological relations, due to the French and Indian War. Britain’s political relations with its American colonies were effected as a result of the French and Indian War. America today, as we know it, would not be the same if the English had not been victorious over the French. The war determined who would gain control of the new world. The m aps in Document A show that before the war, the French controlled most of the new land, but after the war, the English had secured the new world as its territory.It is easy to see that Britains victory over the French helped Britain politically, however; it produced tension with its American colonies. Shortly after the war, England realized what the war had really cost them tons of money they did not have. Britain expected the colonies to help pay the debt from the war, but the colonists felt it was not their responsibility. This controversy contributed to the political strain between Britain and its American colonies.The French and Indian War altered Britains relationship with its American colonies drastically, as Britain imposed its political authority on the colonists. Britains relationship with its American colonies was not only altered politically due to the French and Indian War, but also through its economy. The British began placing taxes upon the colonists and essentially t elling them what they could and could not do and who they could and could not trade with. The colonists were infuriated and felt that the taxation was unjust. Document F states the reason that taxes were placed upon the colonists. TheBritish Order in Council clearly states that, â€Å"we find that the revenue arising there from is very small and inconsiderable,†¦and is not yet sufficient to defray a fourth part of the expense necessary for collecting it. † The commissioners said that all the money it took to make the war happen was not paid back through the land acquired; so, as a result, taxes were placed upon the colonists. Another document that supported this claim about financial troubles was Document H. The picture in Document H was meant to show that after the war, Britain faced extremely rough times economically. Some colonists were depressed, sorrowful, and penniless.The outcome of the French and Indian War damaged Britains economic relations with its American co lonies. The American colonies ideological relations with Britain changed after the French and Indian War. All colonists did not view Britain the same way. In documents D and E, two very distinct views of Britain were displayed. The solider in Document D writes. â€Å"Therefore we now see what it is to be under martial law and to be with [British] regulars, who are but little better than slaves to their officers. † The Massachusetts soldier in this document hated Britain and felt they were treated no better than the slaves.Although, Document E stated, â€Å"Here shall our indulgent Mother, who has protected us, be served and honored by growing Numbers, with the Duty, Love and Gratitude, till Time shall be no more. † Reverend Thomas Barnard said in his sermon that Britain protected them. He felt the colonists should love, honor, and serve Britain forever to show their appreciation. Reverend Barnard viewed Britain as a blessing from God and he loved Britain. The colonists ’ views of Britain were not all the same, while some loved and appreciated Britain, but others hated and criticized them.The French and Indian War completely changed the ideological relations between Britain and its American colonies. As can be seen, Britains relationship with its American colonies was undoubtedly altered due to the results of the French and Indian War. Britains victory over the French came at a cost, as Britain’s grasp on its American colonies began to slip away, and the results of the war changed America as it is known today. The relationship between Britain and its American colonies was altered through the political, economic, and ideological relations, as a result, of the French and Indian War.

Adolescent Sexual Behavior Essay

Introduction Adolescent sexual behavior refers to sexual feelings, behavior, and development in adolescents. It is a stage of human sexuality. The sexual behavior of adolescents is influenced by their culture’s norms and mores, their sexual orientation and the issues of social control. Sexuality is a cultural issue. For humans, sex is a matter of cultural meaning and personal choice than biological programming. Costs and Benefits of Sexual Behavior According to a 2004 study, the rates of adolescent sexual intercourse and birth rates to teenagers in the United States have declined, but a majority of adolescents have been engaging in sexual intercourse before completing high school. 42% of high school students did not use a condom during their last sexual encounter and 14% engaged in sexual activity with approximately four partners. Reducing adolescent sexual activity and the risk for sexually transmitted diseases is a priority under Healthy People 2010, a set of health objectives for the nation to achieve over the first decade of the new century. (Deptula, Shoeny, Slavick, 35) Studies show that there is a link between sexual attitudes and sexual behavior. Attitudes are related to condom use and sexual activity is for both younger and older adolescents. Not surprisingly, high school students reported that positive attitudes toward sex were related to engagement in sexual activity. It was particularly concerning sexual pleasure. Worries about pregnancy and sexually transmitted infections were related to condom use. Theories suggest that attitudes are a key part in the process of making behavioral decisions. The Health Belief Model, a psychological model that attempts to explain and predict health behaviors, is determined by focusing on the attitudes and beliefs of individual. The Decisional Balance model postulates that behavioral decisions are made by assessing and comparing relative gains or losses associated with behavioral engagement. The factors include: costs for the individual and  significant others as well as approval from oneself and significant others. In a study that examined the Costs and Benefits of condom use it was found that the ratings for perceived behavioral costs of protection remained constant over time while perceived benefits of birth control and condom use were associated with behavior change. (Deptula, Shoeny, Slavick, 35) The relation between attitudes and sexual decision-making may also be influenced by the impact of demographic factors such as age, gender, and religion, on attitudes. Boys had more positive attitudes towards sex than girls and girls had more positive views of abstinence. Males also had more liberal attitudes towards premarital casual sex and anxiety, fear and guilt concerning sexuality. They were also more likely to report greater benefits associated with sexual activities than females. Despite the gender differences in attitudes, the beliefs that each held are important predictors for both males and females. Attitudes towards sex become more positive with age and the gender differences in attitudes decreased with age. When an analyses conducted to determine is attitudes words sexual activity were majorly associated with engaging in sexual behavior, it was revealed that adolescents who had never engaged in sexual activity reported more cost associated with intercourse and fewer benefits compared to those who were sexually active. Engagement in sexual activity was linked to a perception of lower costs and greater benefits for intercourse. The primary purpose of the study was to determine which two aspects of attitudes, cost and benefits, predicted parallel and future sexual activity. The effects of costs were equivalent, if not stronger than benefits. The study also suggested that the perception of costs and benefits were both influential in adolescents’ decisions to engage in sexual activity. Based on the theory of Decisional Balance, it is expected that adolescents who decided to engage in sexual activity would report fewer costs and greater benefits associated with having sex, which is somewhat supported by the study. When the likelihood of intercourse was 50%, the awareness of costs was greater than the awareness of benefits. It appears that although  costs still outweigh benefits, adolescents still engage in sexual activity, suggesting that there are other factors that play a role in the decision to have sex. (Deptula, Shoeny, Slavick, 41) The results of the studies have important suggestions for prevention. The start of sexual activity was predicted by both costs and benefits attitudes. Perception of costs was slightly more influential than benefits in prediction later sexual initiation. It is suggested that both of those dimensions be targeted in order to successfully delay adolescent engagement in sexual activity. In studying the costs, it was revealed that its main focus was on teenage pregnancy. The benefits included social status, personal pleasure and interpersonal connection. The study also revealed that females with high cognitive abilities reports more benefits associated with sex while males with lower cognitive abilities reported fewer costs. The Way Teens Define Sex There is certainly a divide between the teenagers of today and generations before them. The divide has to do with what each generation considers to be sex. According to research done by the Centers for Disease Control and Prevention, more than half of 15- to 19-year olds are engaging in oral sex. Adults say that is a form of sex, but teenagers do not see it that way. A 19-year old sophomore in college stated, â€Å"For most teens, the only form of sex is penetration, and anything else doesn’t count. You can have oral sex and be a virgin,† while most adults consider oral sex as something that is extremely intimate. Sarah Brown, director of the National Campaign to Prevent Teen Pregnancy said, â€Å"What we’re learning here is that adolescents are redefining what is intimate.† Teenagers view oral sex as something that is quite casual so it doesn’t need to be done while in a relationship. (Jayson, 1) Psychologist David Walsh stated that the brain is wired to develop intense physical and emotional attraction during the teenage years as a part of the maturing process and he is disturbed by the way that the media portrays casual sex because it gives teenagers a false image on true intimacy. (Jayson, 2) When a parent discovers that their child in engaging in oral sex, they aren’t sure what to think because of the way that teens are so nonchalant about it and parents weren’t usually doing that as teenagers. This could also be due to the fact that many parents do not believe that their child is the one who engages in such things. The definition of abstinence is changing as well. Everyone has a different definition of sexual abstinence. The most common meaning of sexual abstinence is not having any type of sexual intercourse. Abstinence is often linked with how recently a sexual behavior has occurred. If a certain sexual activity did not occur recently, many teens would describe themselves as abstinent, regardless of their sexual history, while others still define it as not doing anything sexual. It just depends on who you are. The Media’s Influence on Sexual Behavior The mass media is becoming the easiest way for young people to learn about sexual behavior and see it as well. Perhaps it is so influential because the teenage years are when we develop our own sexual beliefs and behaviors and parents are very reluctant to talk about sexual issues. The average adolescent spends six to seven hours using media ranging from television to books. That number could be higher by now because most adolescents now have televisions, computers, DVD players and some sort of audio system in their rooms and other parts of their homes besides their living rooms. Much of the media that adolescents are exposed to include sexual imagery but rarely portray consequences of risky sexual encounters or healthy sexual messages. Many health professionals believe that mass media content showing casual sex with no consequences has resulted in a host of negative behaviors among teens who may be persuaded that teen sexual activity is something â€Å"everyone† does.(Hart, 4) Although data shows that adolescents use media very frequently, mass media influences are rarely included as important contexts for adolescents’ sexual socialization. Researchers suggest that media influences showed consistent and significant  association with early adolescent sexual intentions and behaviors. Being male was associated with greater sexual intentions and activity. No religious variable in the study was associated with sexual intentions of behaviors. Perceived sexual permission from the media was also associated with sexual intentions, light sexual activity, and heavy sexual activity. (L’Engle, Brown, Kenneavy, 191) The findings of the study also showed that adolescents who are exposed to more sexual content in their media diets are more likely to engage in sexual intercourse in the near future. The media serves as a â€Å"super peer† for adolescents who wish to seek information about sexuality because it is easily accessible. It has also been said that the information that they receive from the media is different from what they learn from other sexual socialization agents such as parents, school and religion. Media programming rarely shows negative consequences from sexual behavior and depictions of condom and contraception use are very rare, making media users more likely to act the way that they see characters acting because they are seen as realistic and they are not punished for their behavior, making these behaviors convincing to adolescents. (L’Engle, Brown, Kenneavy, 191) Trends and Estimates of Sexual Activity Before getting into the details we must distinguish between sexually experienced and sexually active. Sexually experienced is a teenager who has had sexual intercourse at least once in his/her lifetime. A sexually active teenager is one who has had sexual intercourse in the past three months. The earlier an adolescent has sex, the longer he or she is at risk of pregnancy and contracting an STI. In 2002, approximately one-quarter of never married teenagers has had sexual intercourse before the age of 16. The number increased as age did. Some adolescents who have not engaged in sexual intercourse have engaged in oral sex.(Terry-Humen, Manlove, Cottingham, 3) Since many teenagers do not consider oral sex to be sexual activity, they probably do not concern themselves with the risks of this behavior. Due to  the fact that not many teenage relationships are long term, not all sexually experienced teenagers remain sexually active or are consistently sexually active. Those who are consistently sexually active put themselves at risk for pregnancy and contracting an STI each time they have sex or have sex with a new partner. (Terry-Humen, Manlove, Cottingham, 3) Being in a relationship that teenagers view as romantic is associated with a greater likelihood of having sex. Teenagers with older sexual partners are more likely to engage in sexual intercourse than those with similar age partners. Females are more likely to be in a steady relationship when they have sex for the first time. (Terry-Humen, Manlove, Cottingham, 4) In order to continue with having declines in teen pregnancy and lower the rising rates of STIs, it is suggested that messages of abstinence be reinforced, encourage teenagers to reduce the frequency of sexual activity and partners, educate them about the risks of oral sex, and expand interventions to high-risk populations, such as minority groups. (Terry-Humen, Manlove, Cottingham, 7) Conclusion When it comes to predicting later sexual activity, both Costs and Benefits are important, although attitudes concerning the costs were a bit more influential in predicting sexual activity. It is suggested that both Costs and Benefits be included to hinder sexual activity. Due to the way that every different generation was raised, the way in which we define sex is different to everyone. Baby-boomers see oral sex as something that is very intimate while teenagers see oral sex as something that is casual. The way in which some teenagers behave can end up hurting them in the future because they will not know how to have a long-lasting, healthy relationship. Adolescents who are exposed to sexual content in the media and obtain greater support from the media that is related to sexual behavior have greater intentions to engage in sexual intercourse and other sexual activities. The most obvious ways for teenagers to avoid STIs and unintended teenage pregnancy and childbearing is by delaying sexual initiation or reducing the sexual activity and number of sexual partners as well as improving contraceptive use of those who are sexually active. My Take In my opinion, I think that it’s great that people are trying to reduce the number of teenage pregnancies and STIs in teenagers. I don’t believe that a person should have to be abstinent until marriage or anything like that and I believe that contraception should be used at all times. It is very alarming that kids are having sex at younger ages. I’m with a lot of teens that say that oral sex is not really sex and I think it is due to the time period I’m growing up in. We’re desensitized to these things. I think that it’s important for parents to talk to their kids about sex, even though we probably know more than they think. Many kids I know, as well as myself, surprise our parents with how much we know about sex already because things were different when they were younger. Everything was more hush, hush then. The media is definitely a huge influence on the way that we live our lives today because sex is everywhere and it’s what sells.

Nursing Career and its Advantages in doing Higher Education Essay

Abstract Nursing image is changing every day from ancient gown and cap to colored scrubs. People choose nursing for different reasons. I chose this profession because; I like to be a role model for the new nurses. After I graduated as a Registered Nurse (RN) in 1999 my first patient said, â€Å"If an Angel has dropped from heaven that is you nurse†. R.Mariam (personal communication, June, 1999). This sentence inspired me a lot and gave hope in my career. Job satisfaction is an essential part in any profession especially in this field since, we deal with life and death and it helps to raise patient’s safety, performance, quality of care, patient’s satisfaction and productivity of the organization. Like in any other field, this field also has some frustrations, but facing the problem and coping with frustrations is what helps us to reach the goal. This paper also explains the advantages of doing continuing education since, nursing profession is widely spreading and changing every day and it needs highly qualified knowledgeable and competent employees to serve. Keywords: Nursing profession, Career, Job satisfaction, patient’s safety, quality of care, performance, productivity, frustrations, and continuing education. Nursing Career and its Advantages in doing Higher Education Nursing is an art, science and profession by which we render care for the patients irrespective of all ages, religion, caste or gender who are acutely ill and in critical condition. Nurses around the world make the largest group of health professionals. They are the back bone of the healthcare system. Nurses are not only providing care for the patients, but they are also responsible for the emotional welfare of patients and their families too. Career as a Critical Care Nurse: When I was a kid, I always wanted to pursue a career in nursing or medical field. I have a sister who is a nurse. At the age of 19 years in India, I  decided to go for nursing degree and I graduated as a Registered Nurse in 1999. Nursing profession touched me a lot and it made my career interesting. I started my career as an Operating Room scrub nurse and circulating nurse. It was interesting everyday by not only taking care of the patients, but also managing the operating room activities, ensuring that the equipment’s are safe and sterilized, equipment’s are properly audited and consent forms were filled and signed by concerned members of the family. It is very crucial to be an operating room nurse, as the entire procedure depends on the efficiency and job knowledge. It is the responsibility of the nurse to be the mediator between the patients, families and the physicians. Being an operating room nurse I did not have much interaction with my patients. Almost all patients in operating room gets general anesthesia. As an OR nurse, I felt I am not interacting with the patients well and I am not fulfilling my job as a nurse completely. After few years, I decided to become an Intensive Care Unit (ICU) nurse. Transition from OR to ICU nurse was little hard for me initially, but I enjoy working with the patients and spending enough time with them and their families. At times, I have to be an advocate between the patients, families and doctors because we deal with critically ill patients. Reason for Motivation to continue in Nursing: According to Locke and Lantham (2002), Personal goals play an important part in direction and maintenance of behaviors which is needed to achieve rewards. People who are confident, believe in their ability to achieve goal and believe that the attainment of goal will lead to successful career are the ones able to complete their task effectively to reach their goals (Lent, Brown, & Hackett, 1994). Nursing profession is one of the widely expanding fields that call for passion according to (Raye, L. 2006). It is a good choice for people who find themselves more comfortable and satisfied in helping people who are in need to maintain and achieve normal health. Nursing offers wide variety of opportunities according to each individuals interests such as critical care unit, labor and delivery, pediatrics, geriatrics, telemetry, med-surg, oncology, infectious diseases, pain clinic, outpatient clinic etc. And also  it offers continuing education and competencies to keep the knowledge and skills up-to-date (Raye, L.2006). It offers flexible working hours such as three twelve hour shifts or four ten hour shifts (Blanche, J.2010). And due to the availability and shortage for nurses it offers incentive and bonuses for extra hours. It is a lifetime career which is flexible and rewarding. If we lose jobs in one position there are lots of available jobs in the market for talented individual s. It is also well-paying job with good benefits such as tuition reimbursement for higher education, medical benefits, life insurance and child care. Overall it is flexible. The reason why I have chosen nursing career was, a nurse who inspired me in my life and my interest towards, caring for human beings. The American Association of Colleges of Nursing (1998, 2008) and the National League for Nursing (2007) identified caring as the foundation for nursing. At the age of 15 years old, my dad had a massive heart attack and he was in Intensive care unit. He was intubated, on the ventilator, with so many drips infusing, with monitor alarming all the time. My whole family was very upset and hopeless. The nurse who took care of my dad was very dedicated , honest and very knowledgeable , she went above and beyond in helping us in that situation, keeping track of vital signs, maintaining his breathing, keeping him hemodinamically stable, giving back care, mouth care, sponge bath and giving emot ional support to the family and explaining what’s is going on with him. Few days later my dad died in the hospital but the nurse who took care of my dad stayed in my mind. Since then I always wanted to be a nurse who is caring, attentive to the emotional wellbeing of the patients and their families, providing emotional support because family place trust and self-respect in our hands. They want us to keep their loved ones comfortable, pain free and monitored all the time and not left alone. My passion for nursing grew when a patient or family member smiles at me and say â€Å"Thank you†, it enlightens me and lights up my day with more energy and spirit. Frustrations in Nursing Profession: The most important thing that frustrates me is the charting. Now most of the hospitals are computerized, but some hospitals still do paper charting and add more and more paper work every day. This means I have to spend more time doing paper charting than taking care of the patients. Sometimes we are short staffed and we have to do not only the registered nurse jobs, but we also have to be a house keeper doing accidental cleaning, secretary entering orders, patient care tech, Phlebotomist doing lab draws and also calling doctors with the patient’s lab and radiology results if we don’t see them on rounds. These are the thing which frustrates me, because it reduces the time which we spend for the patient care. Overall, Frustrations are common and it can happen in any other field but the nature of frustration may differ. Advantages due to addition Education in my Career: 1. Now most hospitals in New Jersey prefer Bachelor’s degree in nursing and there is a â€Å"global shortage for nurses, it gives us job security† (Blanche, J.2010). 2. It offers potential high income for well qualified employees. 3. More choice availability to go back to school to continue in higher education for nurse practitioners, nurse anesthetist and nurse educator. 4. It also helps us to interact with the other hospital nurses and health care professionals in classes which help me to improve patient care and make my job more enjoyable. 5. It gives knowledge and skills in critical thinking in assessment and problem solving in everyday practice. 6. It offers opportunity to be a mentor for the new nurses and to be a resource nurse. 7. By doing Bachelor’s degree in nursing, I am sure by the end of the course I will be well trained in areas such as effective communication, leadership and critical thinking which is very important in today’s nursing practi ce as well as it is necessary for administrative position, research and teaching. References American Association of Colleges of Nursing. (1998). The essentials of baccalaureate education for professional nursing practice. Washington, DC: Author. American Association of Colleges of Nursing. (2008). The essentials of baccalaureate education for professional nursing practice. Washington, DC: Author. Blanche, J. (2010). 10 reasons a nursing degree is a good best in education today. Retrieved from http://www.nurses-forum.com/blog/246/10-reasons-a-nursing-degree-is-a-good-bet-in-education-today/ Locke, E. A., & Latham, G. P. (2002).

3 D Optical Storage

3-D OPTICAL DATA STORAGE TECHNOLOGY * *ABSTRACT 3D optical data storage is the term given to any form of optical data storage in which information can be recorded and/or read with three dimensional resolution (as opposed to the two dimensional resolution afforded, for example, by CD). Current optical data storage media, such as the CD and DVD store data as a series of reflective marks on an internal surface of a disc. In order to increase storage capacity, it is possible for discs to hold two or even more of these data layers, but their number is severely limited since the addressing laser interacts with every layer that it passes through on the way to and from the addressed layer. These interactions cause noise that limits the technology to approximately 10 layers. 3D optical data storage methods circumvent this issue by using addressing methods where only the specifically addressed voxel (volumetric pixel) interacts substantially with the addressing light. This necessarily involves nonlinear data reading and writing methods, in particular non linear optics. 3D optical data storage is related to (and competes with) holographic data storage. Traditional examples of holographic storage do not address in the third dimension, and are therefore not strictly â€Å"3D†, but more recently 3D holographic storage has been realized by the use of microholograms. Layer-selection multilayer technology (where a multilayer disc has layers that can be individually activated e. g. electrically) is also closely related. This innovation has the potential to provide terabyte-level mass storage on DVD-sized disks. Data recording and readback are achieved by focusing lasers within the medium. However, because of the volumetric nature of the data structure, the laser light must travel through other data points before it reaches the point where reading or recording is desired. Therefore, some kind of nonlinearity is required to ensure that these other data points do not interfere with the addressing of the desired point. 1. Overview: Current optical data storage media, such as the CD and DVD store data as a series of reflective marks on an internal surface of a disc. In order to increase storage capacity, it is possible for discs to hold two or even more f these data layers, but their number is severely limited since the addressing laser interacts with every layer that it passes through on the way to and from the addressed layer. These interactions cause noise that limits the technology to approximately 10 layers. 3D optical data storage methods circumvent this issue by using addressing methods w here only the specifically addressed voxel (volumetric pixel) interacts substantially with the addressing light. This necessarily involves nonlinear data reading and writing methods, in particular nonlinear optics. 3D optical data storage is related to (and competes with) holographic data storage. Traditional examples of holographic storage do not address in the third dimension, and are therefore not strictly â€Å"3D†, but more recently 3D holographic storage has been realized by the use of microholograms. Layer-selection multilayer technology (where a multilayer disc has layers that can be individually activated e. g. electrically) is also closely related. Schematic representation of a cross-section through a 3D optical storage disc (yellow) along a data track (orange marks). Four data layers are seen, with the laser currently addressing the third from the top. The laser passes through the first two layers and only interacts with the third, since here the light is at a high intensity. As an example, a prototypical 3D optical data storage system may use a disk that looks much like a transparent DVD. The disc contains many layers of information, each at a different depth in the media and each consisting of a DVD-like spiral track. In order to record information on the disc a laser is brought to a focus at a particular depth in the media that corresponds to a particular information layer. When the laser is turned on it causes a photochemical change in the media. As the disc spins and the read/write head moves along a radius, the layer is written just as a DVD-R is written. The depth of the focus may then be changed and another entirely different layer of information written. The distance between layers may be 5 to 100 micrometers, allowing >100 layers of information to be stored on a single disc. In order to read the data back (in this example), a similar procedure is used except this time instead of causing a photochemical change in the media the laser causes fluorescence. This is achieved e. g. by using a lower laser power or a different laser wavelength. The intensity or wavelength of the fluorescence is different depending on whether the media has been written at that point, and so by measuring the emitted light the data is read. It should be noted that the size of individual chromophore molecules or photoactive color centers is much smaller than the size of the laser focus (which is determined by the diffraction limit). The light therefore addresses a large number (possibly even 109) of molecules at any one time, so the medium acts as a homogeneous mass rather than a matrix structured by the positions of chromophores. 2. History: The origins of the field date back to the 1950s, when Yehuda Hirshberg developed the photochromic spiropyrans and suggested their use in data storage. [3] In the 1970s, Valeri Barachevskii demonstrated that this photochromism could be produced by two-photon excitation, and finally at the end of the 1980s Peter T. Rentzepis showed that this could lead to three-dimensional data storage. [5] This proof-of-concept system stimulated a great deal of research and development, and in the following decades many academic and commercial groups have worked on 3D optical data storage products and technologies. Most of the developed systems are based to some extent on the original ideas of Rentzepis. A wide range of physical phenomena for data reading and recording have been investigated, large numbers of chemical systems for the medium have been developed and evaluated, and extensive work has been carried out in solving the problems associated with the optical systems required for the reading and recording of data. Currently, several groups remain working on solutions with various levels of development and interest in commercialization. *3. Processes for creating written data*: Data recording in a 3D optical storage medium requires that a change take place in the medium upon excitation. This change is generally a photochemical reaction of some sort, although other possibilities exist. Chemical reactions that have been investigated include photoisomerizations, photodecompositions and photobleaching, and polymerization initiation. Most investigated have been photochromic compounds, which include azobenzenes, spiropyrans, stilbenes, fulgides and diarylethenes. If the photochemical change is reversible, then rewritable data storage may be achieved, at least n principle. Also, multilevel recording, where data is written in ‘grayscale’ rather than as ‘on’ and ‘off’ signals, is technically feasible. 3. 1 Writing by non*-*resonant multiphoton absorption Although there are many nonlinear optical phenomena, only multiphoton absorption is capable of injecting into the media the significant energy required to electronically excite molecular species and cause chemical reactions. Two-photon absorption is the strongest multiphoton absorbance by far, but still it is a very weak phenomenon, leading to low media sensitivity. Therefore, much research has been directed at providing chromophores with high two-photon absorption cross-sections. Two photon absorption (TPA) is the simultaneous absorption of two photons of identical or different frequencies in order to excite a molecule from one state (usually the ground state) to a higher energy electronic state. The energy difference between the involved lower and upper states of the molecule is equal to the sum of the energies of the two photons. Two-photon absorption is a second-order processes several orders of magnitude weaker than linear absorption. It differs from linear absorption in that the strength of absorption depends on the square of the light intensity, thus it is a nonlinear optical process Writing by 2-photon absorption can be achieved by focusing the writing laser on the point where the photochemical writing process is required. The wavelength of the writing laser is chosen such that it is not linearly absorbed by the medium, and therefore it does not interact with the medium except at the focal point. At the focal point 2-photon absorption becomes significant, because it is a nonlinear process dependent on the square of the laser fluence. Writing by 2-photon absorption can also be achieved by the action of two lasers in coincidence. This method is typically used to achieve the parallel writing of information at once. One laser passes through the media, defining a line or plane. The second laser is then directed at the points on that line or plane that writing is desired. The coincidence of the lasers at these points excited 2-photon absorption, leading to writing photochemistry. 3. 2 Writing by sequential multiphoton absorption Another approach to improving media sensitivity has been to employ resonant wo-photon absorption (also known as â€Å"1+1† or â€Å"sequential† 2-photon absorbance). Nonresonant two-photon absorption (as is generally used) is weak since in order for excitation to take place, the two exciting photons must arrive at the chromophore at almost exactly the same time. This is because the chromophore is unable to interact with a single photon alone. However, if the chromophore has an ene rgy level corresponding to the (weak) absorption of one photon then this may be used as a stepping stone, allowing more freedom in the arrival time of photons and therefore a much higher sensitivity. However, this approach results in a loss of nonlinearity compared to nonresonant 2-photon absorbance (since each 1-photon absorption step is essentially linear), and therefore risks compromising the 3D resolution of the system. 3. 3 Microholography In microholography, focused beams of light are used to record submicrometre-sized holograms in a photorefractive material, usually by the use of collinear beams. The writing process may use the same kinds of media that are used in other types of holographic data storage, and may use 2-photon processes to form the holograms. . 4 Data recording during manufacturing Data may also be created in the manufacturing of the media, as is the case with most optical disc formats for commercial data distribution. In this case, the user cannot write to the disc – it is a ROM format. Data may be written by a nonlinear optical method, but in this case the use of very high power lasers is acceptable so media sensitivity becomes less of an issue. The fabrication of discs containing data molded or printed into their 3D structure has also been demonstrated. For example, a disc containing data in 3D may be constructed by sandwiching together a large number of wafer-thin discs, each of which is molded or printed with a single layer of information. The resulting ROM disc can then be read using a 3D reading method. 3. 5 Other approaches to writing Other techniques for writing data in three-dimensions have also been examined, including: Persistent *spectral** **hole burning* (PSHB), which also allows the possibility of spectral multiplexing to increase data density. However, PSHB media currently requires extremely low temperatures to be maintained in order to avoid data loss. Void* formation, where microscopic bubbles are introduced into a media by high intensity laser irradiation. [7] Chromophore poling, where the laser-induced reorientation of chromophores in the media structure leads to readable changes. *4. Processes for reading data*: The reading of data from 3D optical memories has been carried out in many different ways. While some of these rely on the nonlinearity of the light-matter interaction to obtain 3D resolution, others use methods that spatially filter the media's linear response. Reading methods include: Two photon absorption (resulting in either absorption or fluorescence). This method is essentially two-photon-microscopy. Linear excitation of fluorescence with confocal detection. This method is essentially confocal laser scanning microscopy. It offers excitation with much lower laser powers than does two-photon absorbance, but has some potential problems because the addressing light interacts with many other data points in addition to the one being addressed. Measurement of small differences in the refractive index between the two data states. This method usually employs a phase contrast microscope or confocal reflection microscope. No absorption of light is necessary, so there is no risk of damaging data while reading, but the required refractive index mismatch in the disc may limit the thickness (i. e. number of data layers) that the media can reach due to the accumulated random wavefront errors that destroy the focused spot quality. Second harmonic generation has been demonstrated as a method to read data written into a poled polymer matrix. Optical coherence tomography has also been demonstrated as a parallel reading method. *5. Media *design: The active part of 3D optical storage media is usually an organic polymer either doped or grafted with the photochemically active species. Alternatively, crystalline and sol-gel materials have been used. 5. 1 Media form factor Media for 3D optical data storage have been suggested in several form factors: Disc. A disc media offers a progression from CD/DVD, and allows reading and writing to be carried out by the familiar spinning disc method. Card. A credit card form factor media is attractive from the point of view of portability and convenience, but would be of a lower capacity than a disc. Crystal, Cube or Sphere. Several science fiction writers have suggested small solids that store massive amounts of information, and at least in principle this could be achieved with 3D optical data storage. 5. 2 Media manufacturing The simplest method of manufacturing – the molding of a disk in one piece – is a possibility for some systems. A more complex method of media manufacturing is for the media to be constructed layer by layer. This is required if the data is to be physically created during manufacture. However, layer-by-layer construction need not mean the sandwiching of many layers together. Another alternative is to create the medium in a form analogous to a roll of adhesive tape. *6. Drive design*: A drive designed to read and write to 3D optical data storage media may have a lot in common with CD/DVD drives, particularly if the form factor and data structure of the media is similar to that of CD or DVD. However, there are a number of notable differences that must be taken into account when designing such a drive, including: Laser. Particularly when 2-photon absorption is utilized, high-powered lasers may be required that can be bulky, difficult to cool, and pose safety concerns. Existing optical drives utilize continuous wave diode lasers operating at 780 nm, 658 nm, or 405 nm. 3D optical storage drives may require solid-state lasers or pulsed lasers, and several examples use wavelengths easily available by these technologies, such as 532 nm (green). These larger lasers can be difficult to integrate into the read/write head of the optical drive. Variable spherical aberration correction. Because the system must address different depths in the medium, and at different depths the spherical aberration induced in the wavefront is different, a method is required to dynamically account for these differences. Many possible methods exist that include optical elements that swap in and out of the optical path, moving elements, adaptive optics, and immersion lenses. Optical system. In many examples of 3D optical data storage systems, several wavelengths (colors) of light are used (e. g. eading laser, writing laser, signal; sometimes even two lasers are required just for writing). Therefore, as well as coping with the high laser power and variable spherical aberration, the optical system must combine and separate these different colors of light as required. Detection. In DVD drives, the signal produced from the disc is a reflection of the addressing laser beam, and is therefore very intense. For 3D optical storage however, the signal mus t be generated within the tiny volume that is addressed, and therefore it is much weaker than the laser light. In addition, fluorescence is radiated in all directions from the addressed point, so special light collection optics must be used to maximize the signal. Data tracking. Once they are identified along the z-axis, individual layers of DVD-like data may be accessed and tracked in similar ways to DVD discs. The possibility of using parallel or page-based addressing has also been demonstrated. This allows much faster data transfer rates, but requires the additional complexity of spatial light modulators, signal imaging, more powerful lasers, and more complex data handling. *7. Development issues*: Despite the highly attractive nature of 3D optical data storage, the development of commercial products has taken a significant length of time. This results from limited financial backing in the field, as well as technical issues, including: Destructive reading. Since both the reading and the writing of data are carried out with laser beams, there is a potential for the reading process to cause a small amount of writing. In this case, the repeated reading of data may eventually serve to erase it (this also happens in phase change materials used in some DVDs). This issue has been addressed by many approaches, such as the use of different absorption bands for each process (reading and writing), or the use of a reading method that does not involve the absorption of energy. Thermodynamic stability. Many chemical reactions that appear not to take place in fact happen very slowly. In addition, many reactions that appear to have happened can slowly reverse themselves. Since most 3D media are based on chemical reactions, there is therefore a risk that either the unwritten points will slowly become written or that the written points will slowly revert to being unwritten. This issue is particularly serious for the spiropyrans, but extensive research was conducted to find more stable chromophores for 3D memories. Media sensitivity. 2-photon absorption is a weak phenomenon, and therefore high power lasers are usually required to produce it. Researchers typically use Ti-sapphire lasers or Nd:YAG lasers to achieve excitation, but these instruments are not suitable for use in consumer products. *8. Academic development*: Much of the development of 3D optical data storage has been carried out in universities. The groups that have provided valuable input include: Peter T. Rentzepis was the originator of this field, and has recently developed materials free from destructive readout. *Watt W. Webb* co developed the two-photon microscope in Bell Labs, and showed 3D recording on photorefractive media. Masahiro Irie developed the diarylethene family of photochromic materials. [13] Yoshimasa Kawata, *Satoshi Kawata* and Zouheir Sekkat have developed and worked on several optical data manipulation systems, in particular involving poled polymer systems. 14] Kevin C Belfield is developing photochemical systems for 3D optical data storage by the use of resonance energy transfer between molecules, and also develops high 2-photon cross-section materials. Seth Marder performed much of the early work developing logical approaches to the molecular design of high 2-photon cross-section chromophores. Tom Milster has made many contributions to the theory of 3D optical data storage. Robert McLeod has examine d the use of microholograms for 3D optical data storage. Min Gu has examined confocal readout and methods for its enhancement. 9 Commercial development*: In addition to the academic research, several companies have been set up to commercialize 3D optical data storage and some large corporations have also shown an interest in the technology. However, it is not yet clear whether the technology will ever come to market in the presence of competition from other quarters such as hard drives, flash storage, holographic storage and internet-based storage. Examples of 3D optical data storage media. Top row – Written Call/Recall media; Mempile media. Middle row – FMD; D-Data DMD and drive. Bottom row – Landauer media; Microholas media in action. Call/Recall was founded in 1987 on the basis of Peter Rentzepis' research. Using 2-photon recording (at 25 Mbit/s with 6. 5 ps, 7 nJ, 532 nm pulses), 1-photon readout (with 635 nm), and a high NA (1. 0) immersion lens, they have stored 1 TB as 200 layers in a 1. 2 mm thick disk. [23] They aim to improve capacity to >5 TB and data rates to up to 250 Mbit/s within a year, by developing new materials as well as high-powered pulsed blue laser diodes. Mempile are developing a commercial system with the name TeraDisc. In March 2007, they demonstrated the recording and readback of 100 layers of information on a 0. mm thick disc, as well as low crosstalk, high sensitivity, and thermodynamic stability. [25] They intend to release a red-laser 0. 6-1. 0 TB consumer product in 2010, and have a roadmap to a 5 TB blue-laser product. [26] *Constellation 3D* developed the Fluorescent Multilayer Disc at the end of the 1990s, which was a ROM disk, manufactured layer by layer. The company failed in 200 2, but the intellectual property (IP) was acquired by D-Data Inc. who are attempting to introduce it as the Digital Multilayer Disk (DMD). Storex Technologies has been set up to develop 3D media based on fluorescent photosensitive glasses and glass-ceramic materials. The technology derives from the patents of the Romanian scientist Eugen Pavel, who is also the founder and CEO of the company. First results, 40 nm marks recorded into 3D virtual layers separated by 700 nm, were presented in October 2009 at the ISOM2009 conference. Landauer inc. are developing a media based on resonant 2-photon absorption in a sapphire single crystal substrate. In May 2007, they showed the recording of 20 layers of data using 2 nJ of laser energy (405 nm) for each mark. The reading rate is limited to 10 Mbit/s because of the fluorescence lifetime. Colossal Storage aim to develop a 3D holographic optical storage technology based on photon induced electric field poling using a far UV laser to obtain large improvements over current data capacity and transfer rates, but as yet they have not presented any experimental research or feasibility study. Microholas operates out of the University of Berlin, under the leadership of Prof Susanna Orlic, and has achieved the recording of up to 75 layers of microholographic data, separated by 4. micrometres, and suggesting a data density of 10 GB per layer. [33] 3DCD Technology Pty. Ltd. is a university spin-off set up to develop 3D optical storage technology based on materials identified by Daniel Day and Min Gu. Several large technology companies such as Fuji, Ricoh and Matsushita have applied for patents on 2-photon-responsive materials for applications including 3D optical data storage, however they have not giv en any indication that they are developing full data storage solutions.