Human-Computer Interaction Research Paper Example | Topics and Well Written Essays - 2000 words

Human-Computer Interaction - Research Paper Example Back in the 80’s, when human-computer interfaces were born, the factors of ergonomics and user-friendly design were mostly ignored, which led to dissatisfied users and threatened the life of the interface. But as the computer software and hardware industry developed, so did the methods of evaluation of these products. The development and innovation in computer systems, may it be software or hardware, requires constant usability testing and interface modifications. This technique is used to evaluation a product by testing it on users. This is inarguably an irreplaceable testing practice since it gives a direct input on how users use the system (Nielsen, J.,1994). These modifications need to take place constantly thorough the development cycle of a particular software or hardware. Various methods can be employed in order to test and evaluate a particular computer interface in development. . A. USER-BASED TECHNIQUES An array of techniques is available for evaluating the usability of a particular interface. Overall, these techniques can be classified in the following categories: 1. User-Based The user-based method, as the name implies, takes real users as a testing medium. This method yields the most reliable and valid results as it directly analysis the feedback from the user. In this technique, a group of users are provided with the test interface in a defined environment or out in the field. They interaction with the interface is closely observed with emphasis on how they use that particular software or hardware to complete their task. Speed is also one of the primary gauges. After the task is complete, users are then interviewed and are asked to describe their own experience and perception of the interface. Thus, using this data and feedback, the interface can be further improved which will eventually improve the satisfaction level of the user. The user-based evaluation procedure is usually video recorded and analyzed later. However, this evaluation can also be in the form of a joint interaction between the user, the evaluator and the interface under evaluation. This enables the evaluator to get a more hands-on feedback from the user. Ideally, a large group of users would provide a more concrete feedback, but this is not always logistically possible. As a result, there is a considerable interest among HCI professionals in how to get the best feedback from the smallest focus group. While popular myths exist about being able to determine a majority of problems with only 2 or 3 users, it is believed that a sample size requirement is largely dependent on the type of errors one seeks to identify and their relative probability of occurrence. Whereas 3 users might identify many problems in a new application, substantially more users will be required to tease out the remaining problems in a mature or revised product (Lewis 1994). 2. Expert-Based Once again, as the name suggests, an expert-based evaluation is when an HCI expert evaluates th e application in order to determine and forecast its usability in the hands of the user. Obviously, this method is far more cost efficient and quick as compared to the user-based evaluation as it does not involve hiring a focus group and then analyzing their feedback. In HCI, two common expert-based usability evaluation methods are Heuristic evaluation (e.g., Nielsen, 1994), and Cognitive Walkthrough (Wharton et al, 1994). In the Heuristic method, the evaluator is provided with a simple checklist made according to a set guideline which he uses to evaluate the application step by step. Any incompliancy of the application with respect to the list is treated as a problem. In the Cognitive Walkthr

Essay on school uniforms Essay Example for Free

Essay on school uniforms Essay Imagine being able to wake up every morning, roll out of bed, put on the same thing you wore the day before, and head off to school. Not only would you be able to do such a thing, but all of your friends were doing it, too! Sound too good to be true? Well, its becoming more common in our society as school uniforms have gone beyond private schools to public schools. Uniforms have a positive effect on students self-esteem, attendance, discipline, and test scores. They have also been proven to decrease the rate of crime and violence in public schools. Most students and even parents will argue that SCHOOL UNIFORMS stifle individualism. The teenage years are a time when adolescents try out different personas, often experimenting with different styles of clothing during this phase. Opponents argue that uniforms take away an individuals freedom of expression. However, the clothes that people wear, or can afford to wear, often define the group by which they are accepted. As a result, many teens are outcast due to the fact that they cannot afford the top-of-the-line, name-brand clothing. This rejection can lead to several problems for the outcast teen: depression, inability to concentrate on schoolwork, or just a general feeling of inferiority. School uniforms put everyone on the same level because no outfit is more stylish or expensive than another. Linda Moore, principal at Will Rogers Middle School in Long Beach, California, states, Uniforms reduce the differences between the haves and have-nots (Ritter, 1). Uniforms allow students to interact with one another without experiencing the socioeconomic barrier that non-uniform schools create. More importantly, children are not judged on how much they spent on clothes or how stylish they look, but rather for their talents and personalities. School uniforms not only break down socioeconomic barriers, but they also increase the safety of the students. In 1996, President Bill Clinton encouraged the use of school uniforms as part of an education program that sought to improve safety and discipline (Hoffman, 1). If students are all wearing the same type of outfit, it becomes much easier to spot outsiders  who may wander onto the campus. In addition, uniforms decrease the number of incidences of students being attacked or beaten for items of clothing such as shoes and jackets. Also, members of gangs frequently have a color or style of clothing used to identify themselves. Unsuspecting students who wear gang colors or gang-related attire might be threatened or intimidated by members of opposing gangs, students wearing expensive or fashionable clothes might become victims of theft, or certain fashion accessories or attire may be used as a means of concealing weapons, or even as weapons (Paliokas, 1). At a school in Long Beach, California, after only the first year that uniforms were implemented, overall school crime decreased 36 percent, fights decreased 51 percent, sex offenses decreased 74 percent, weapons offenses decreased 50 percent, assault and battery offenses decreased 34 percent, and vandalism decreased 18 percent (Manual, 3). Schools with uniform-clad students are also proven to have fewer disciplinary problems and increased attendance than non-uniform schools. Dr. John German, principal of South Shore, located in Seattle, Washington, reports, This year the demeanor in the school has improved 98 percent, truancy and tardies are down, and we have not had one reported incident of theft (Manual,4). Ruffner Middle School, located in Norfolk, Virginia, reports a 47 percent decrease in students leaving class without permission (Manual,5). With the implementation of uniforms, students no longer spend hours deciding what they are going to wear to school. This fear of looking uncool will often cause kids to decide that they do not feel well enough to go to school because they cant find anything to wear. Uniforms allow students to focus more on their academics, and less on what everyone else is wearing. According to Long Beach police chief William Ellis, Students concentrate more on education, not on whos wearing $100 shoes or gang attire (Manual, 3). Elementary Guidance Counselor Sharon Carter of Memphis, Tennessee states, The tone of the school is different. Theres not the competitiveness†¦about whos wearing what (Manual, 5). Many families worry about not having enough money to buy uniforms. Due to the fact that no child can be denied an education because of economic  disadvantage, all schools requiring uniforms must include provisions to assist low-income families. For example, the Long Beach School District solved this problem by setting up a boutique shop, funded by private donors, where needy students can shop (Paliokas, 5). In addition, community and business leaders provide or contribute financial support for uniforms, and students who have graduated often donate their used uniforms to incoming students (Manual, 3). However, uniforms are considerably cheaper to buy than non-uniform clothes, and the students can wear them every day and it isnt considered unusual. Parents can buy a few pairs of pants, shirts, or other variations of a uniform for under $100, while parents of non-uniform-wearing students can spend from several hundred up to $1,000 a year on clothing. Parents find that buying two or three uniforms is ultimately cheaper than buying clothes to follow the fads, and it stops arguments at home in the mornings about what to wear (Oland, 1). Pop culture increasingly sends young girls the message that the smaller and tighter the clothes, the more readily they will be accepted. These outfits, which flaunt navels and bra straps, are not only distracting, but detract from teaching time as teachers argue with students about what is considered acceptable attire. With uniforms, there are only a few acceptable variations of the outfit, no questions asked. A less well-known theory concerning the pros of school uniforms is the halo effect. According to researcher Marc Posner, the halo effect refers to the idea that while uniforms may not change student behavior, the uniforms may change the way teachers and other adults perceive the students who wear them. In a study of the correlation of student clothing and teacher and student perceptions, Dorothy Behling of Bowling Green University found that students and teachers alike believe that uniform-clad students not only behave better, but also do better academically than those who dont wear uniforms. While this may be an illusion, these positive perceptions can help create a self-fulfilling prophecy that teachers and administrators raise their discipline and grading standards to reflect their more positive image of students, who, in turn, behave better. (School Discipline, 1). While research on the effectiveness of uniforms is still ongoing, they have been proven to raise test scores, boost self-esteem, reduce violence and crime, and create a sense of newfound pride in students. They help children to focus on learning and schoolwork, not on what everyone else is wearing or whether or not they fit in. Uniforms are not the solution to all of the problems that teens, teachers, and schools face today, but research and statistics suggest that they may be a step in the right direction.

Essay on the Difference Between Chiefdoms and Tribes

Essay on the Difference Between Chiefdoms and Tribes Introduction The Swazi of Southern Africa and the Mayogo of Northern Democratic Republic of Congo represent two different chiefdoms that live in Africa. The two chiefdoms share more with states than with tribes, a reason which explains its existence within the boundary of many states in Africa. The Swazi chiefdom is situated in the southern Africa in a landlocked country that was rule according to the chiefdom rules even with the coming of the white man and obtaining independence 1968. The chiefdom share many aspects with the state, a reason which explains the absence of conflict that inflicts the two institutions in comparison with the state and the tribe. The research paper will analyze the two chiefdoms of Mayogo and Swazi through the use of comparison with the state and the tribe by focusing on such points as kinship, marriage, citizenship. The Mayogo The Mayogo are people who live in the Northeast of the Democratic Republic of Congo, they used to live independently as chiefdom until the 19th century when the country was invaded by the Mangbetu who formed the state under which the Mayogo were governed. However, the internal affairs of the chiefdom were in control by the chiefs. The Mayogo speak a language that belongs to the same family of Swazi which is Bantu, most of them have converted from animism to Christianity mainly Catholicism. The areas in which the Mayogo live have certain autonomy as the people pay allegiance to the Chiefdom. Although the flag was apparent in the documentary but no allegiance is paid to the national anthem. One of the reason, why the state of Democratic Republic of Congo, formerly known as Zaire is not bother by the presence of the chiefdom of Mayogo in its territory is because it is not menaced by it in addition to the fact that the chiefdom provides protection to its population which the state cannot afford to due to the vast surface of the territory and its vicinity to war zones exemplified by the refuges that live in the country in addition to a civil war that it is undergoing. The Swazi The Swazi took their name from their king, Mswati, Swaziland is a chiefdom that is organized into dual monarchy with the king and the queen at its head, the king is refereed to by the Swazi as Ngwenyama (Lion) while the queen is known as Ndlovukazi (Lady Elephant).[1] The chiefdom is based on common ancestry and fictive kinship, like the state the chiefdom is based on a social contract between the population of Swaziland who accept top pay allegiance to the king by obeying his orders, providing goods and services, and paying taxes in return for protection from outsiders mainly Zulu and Shaka. For instance, King Sobhuza maintained the loyalty of his population by protecting them from Shaka to the extent that he sent his daughters to be married by Shaka knowing that they will be killed once they are pregnant.[2] The successor of king Sobhuza, Mswati, was left with a strong Kingdom, respected and feared by neighboring tribes, with a centralized political system controlling several thous ands of people scattered over areas reaching far beyond the boundaries of modern Swaziland.[3] The interest of Europeans to colonize the area came from two parties the Dutch Boers and the British, in 1865 the two parties are going to find an excuse to enter the country which to provide peace and end civil war. The year coincided with the death of King Mswati which entered the country into a civil war due the rivalry of who is going to become the new king. Eventually Mdandzeni was the king and even during his reign instability was present.[4] A Comparison between Chiefdom and Tribe The tribe and chiefdom have a similar aspect in terms of their value of raiding while the Swazi during the reign of king Mswati acquired a reputation of terror and fear many of their warriors were indulging in raids with neighboring chiefdoms and the looting was distributed by the King.[5] Likewise, the Famous tribe chief Auda abu Tayi the leader of the Howeitat tribe who said that he is like a river to his people meaning that all what he obtain from raids is going to be redistribute to his tribe.[6] Moreover, Hospitality is another characteristic that shared between tribes and chiefdom. Regarding chiefdom, the headman is expected to be magnanimous.[7] Kinship is an important factor that distinguishes chiefdom from the state and put on equal footing with the tribe, it used to define who is going to be married from a particular person and other issue as it is stated by Hilda Kuper kinship by descent and ties by marriage influence behavior in a great number of situations; they determine where and with whom a person lives, his range of friends and enemies, whom he may or may not marry, the positions to which he is entitled.[8] Regarding tribes the preference is being given to first cousins but instances of incest are not absent though rare, both among Tribes Swazi, especially the king who is allowed as he is the only man permitted to marry a clan sister.[9] This network of kinship was kept even when the British administration was in the country, it was only a current move to incorporate the dual monarchy as a single government for the whole country of Swaziland.[10] The importance given to law seems to be a feature shared by both the tribe and chiefdom as the tribe regulates its problems according to its tribal law while the Swazi have a highly developed legal system and a graded hierarchy of courts that coincide roughly with the political structure. In case of the Swazi seems to be working with the introduction of the state while it is the opposite for tribes as in some instances revenge requires killing a person as compensation. While the Swazi differentiate between private matters such as theft and cases that require death penalty such as murder. In The former the guilty party pays compensation directly to the ill-treated person while on the latter the compensation is given to the king as he the representative of the state.[11] Hilda Kuper mentioned an example that would illustrate this dichotomy of law among the chiefdom. It involves the case of a woman called Velepi Hlatshwako who deserted her husband, Alpheus shongwe, after 20 years of mar riage because of his bad treatment of her and eloped with her lover, Isauk Mabuzo. In order for the lover to marry the Velepi he has to pay lobola (bride price) to her family which it refused. The matter is going to exacerbates when Velepi had a daughter and Alpheus asked for both of them as a he paid lobola. This time the two couple became convert to Wesleyan church therefore the matter was taken to different court and in the end the court stated that Velepi soiled the law.[12] The state and chiefdom law tend to overlap and contradict each other, however the likelihood of going against the states is less than the tribe where state rule is absent. For instance, the Swazi people who work in the administration or white-controlled bureaucracy[13] but their loyalty falls under their chiefdom. One of the major difference between chiefdom and tribe lies on the fact that the way the tribal chief chosen has nothing to do with his noble heritage or family instead what matter is his reputation for hospitability, honor and experience while for the Swazi as well as the Mayogo of Northern Democratic Republic of Congo the chief is hereditary position which is banqueted only by inheritance. Therefore, competition and rivalry is major aspect of chiefdom and this best seen during the death of Kind Mswati, that resulted in a civil war between his sons whereas tribal people tend to elect a chief of their tribe based on reputation, which means that once the chief is being seen as corrupt the tribal people outstrip of his leadership automatically by not listening to him. And even the way the tribe vie their chief is different from chiefdom whereby the Swazi regard their king as a father and not a dictator.[14] Marriage is an important institution upon which a the follower of the king is taken, polygamy is abundant among kings and in order to avoid conflict between kings` sons it is the child of the senor wife that is entitled to the throne however, seniority is not always decided by age but by other factors as it is pointed out by Hilda Kuper Among the Swazi aristocracy the first wife is never the main wife. Seniority in marriage brings certain advantages during the headman`s lifetime, but upon his death other factors are considered. The most important is pedigree, and the daughter of a king or leading chief generally takes precedence over all other wives.[15] The Swazi developed a sophisticated system of succession to protect the future king from the rivalry of his brothers to the extent that the first son of king is never going to take his place, Seniority and pedigree play an important role in selecting the future king.[16] Regarding tribal law, it is very different from state law and d oes not tend to be mixed as is the case with both Swazi and Mayogo as knowledge of the chiefdom law and court procedure are part of the daily life of chiefdom people.[17] A Comparison between the Chiefdom and the State Just like the state, the country of Swaziland is divided into different districts. The queen shares power with the king, however her realm is situated in the area of household and rituals. Unlike Western countries, religion in Swaziland is an important aspect of the country that is governed by the queen; it is one of the characteristics that differentiate an outsider from a Swazi. The Swaziland chiefdom maintains its political system and insures its survival by following a system of military fear based on executions so that any enemy would think twice before trying to invade the country. The second way is upgrading lineage through marriage, whereby women play a major role in succession mainly the queen mother, as the children of a senior wife are supervised and shunned from going outside to protect them from magic spills. In other words, the king rules outside while the queen rules inside the household. Even though the country is big, the king insure that it stays in order by dividin g into district and letting local chiefs (sikhulu) reign them and in cases of district that the king does not trust he appoints his brother or his half brother to rule them, a practice used during the reign of King Mswati, when the Kingdom of Swaziland rule over a large territory and have a reputation. According to Hilda Kuper power moves down through a chain of British-appointed officials on the one side and the traditional hierarchy on the other, with conflict centered in a few leading personalities. Educated Swazi, including some of the traditional system for reaching rapid and major decisions, but they are seeking to build on certain accepted foundations and do not want an imitation of constitutional techniques developed in alien context.[18] In a chiefdom both power can be shared with states with small incidents of conflicts compared to tribes, and most of the time when the chiefdom laws came to contradict laws of the states it is usually driven by personal interest. For instance, the reason for changing the Westminster constitution that the British brought to Swaziland has to do with the failure of a Prince Mfanasibili in elections against Ngwenya, therefore to get rid of his rival he found the loophole that since he is a South African he was deported to the border in may 25 1972 and because the conistution was in favour of Ngwenya regarding his deportation, it was also changed.[19] The independence of Swaziland brought the problem of who is entitled toser ve in an office with such factors as loyalty and family playing a major role in appointment the educated Swazi who are not from a royal kinship posed a problem to the royal group and raised their concern over education as a means to secure their positions. The opposite is apparent in the Mayogo of Northern Democratic Republic of Congo. Unlike the British colonies where education was emphasize, the French colonies relied on military people to rule on their colonies Citizenship is an important aspect of defining who is Swazi and who is not, in practice all those people entitled to be Swazi have the privileges of security, that is protection from enemies, they can acquire land; and most importantly they can have the national mark in order to wear Swazi consume which is a slit in the lobes of the ears.[20] The chiefdom shares with the state the concept of citizen and who is entitled to be a citizen? Such a question is going to raise problems in Swaziland due to its diversified population and the changing concept of allegiance, as it system by which Swazi express their loyalty to their king. However, the influx of many non-Swazi who were brought by the white settlers brought the issue of loyalty to the fore as they plead their allegiance to their employers instead of the king, in addition to their different traditions and culture which makes the Swazi feel threatened about their status to the extent of putting the blame on crime on the non-Swazi po pulation.[21] According the Swaziland law Citizenship was a privilege, not a right; a commitment, not a label,[22] which means that factors such as language, history, race and religion come to define who is a Swazi and who is not, therefore citizenship is exclusive and not inclusive. Another problem that is brought the issue of citizenship is the fact that South Africa is home to 700, 000 Swazi people which indicates the problem of the king to grant them citizenship without land support and most importantly the problem of dual citizenship as they are both citizens of South Africa and also entitled to the citizenship of Swaziland, while the non-Swazi who live in Swaziland are not regarded as citizens as they lack the features of a Swazi. Land is an important accepts in Swaziland in addition to pastorals rooted in its cattle complex[23] due to the importance of lobola which is usually expressed in cattles. The land posed to be a problem in 1907 as 45% of the land in Swaziland was owned by non-Swazi owing to the Land Proclamation of 1907.[24] Unlike, its neighboring country Zimbabwe, the Swaziland government response to reform the land by taking into consideration the local Swazi without alienating the white community A major component of the state in addition to sovereignty and territory is monopoly over the use of violence. The distinction between police and soldier does not exit in Swazi chiefdom it was only brought by the British. The Swazi rely on emabutfo to provide protection; they are a mix of soldier and police. However by the coming of the British they introduced police force which was viewed as a rival by Emabutfo.[25] However the role of Emabutfo is going to be underscored due to the regional incidents that occurred in Ethiopia where Haile Selassie was deposed and Mozambique where the socialist Samora Machel was recognized as the leader of the country. These events prompted Swaziland to develop an army by relying on emabutfo. [26] Conclusion To conclude, the chiefdom share many point with tribes and states. however, the fact it has many point to share with the state that the tribe make it adaptable to survive even within the boundary of the state because it does not threat the establishment of the state. It shares with the state the social contract under which the population pays loyalty through obedience and taxes in return for protection. And unlike the tribe the chiefdom does not have the problem of minority group. Because even in their meeting not everybody in the chiefdom is invited in the secret meetings save the elders, whereas in a tribal society every person who is an adult has a saying that the chief has to take into consideration as he has the power to influence decision making but to the extent of making an order. Bibliography Chief Anga Ganga Kangolo Lost Kingdoms. Discovery Channel, 1988. Kuper, Hilda. The Swazi: a South African Kingdom. Mason, Ohio: Cenage Learning, 2002. Lawrence of Arabia, DVD, Directed by David Lean. 1962.

Introduction To Microbial Genetics

Introduction To Microbial Genetics In this experiment, handling bacteria was learned and phenotypes of bacteria in microbial genetics are investigated. For the phenotypes, E. coli and its mutants are used. The second part was done to observe plate assays to see whether or not the ÃŽ ²-galactosidase was produced or not. The last part was to assay plaque forming units in E. coli medium infected with a sample of B. subtilus phage SPO1. Auxotrophic mutants require specific nutrient or compound to grow and express its phenotypes (Madoka). Bacterial growth involves lac operon. Therefore, it is crucial to understand the functionality of lac operon. There are three genes of lac operon which needs for lactose metabolism: lac Z, lac Y, and lac A. lac Z encodes ÃŽ ²-galactosidase enzyme, lac Y encodes ÃŽ ²-galactosidase permease and lac A encodes lactose transacetylase. (2)(1) This experiment introduces a few ways to test lac phenotypes. One way is to use minimal lactose medium. In this medium, Lac- will not grow whereas Lac+ will grow. Second way is to use MacConkey medium. MacConkey medium is a pH sensitive medium which would show red in the acidic medium. In this medium, both Lac+ and Lac- will grow on the plate but Lac+ would be the only one that would turn red. The reason is because the fermentation of lactose by Lac+ produces acidic metabolite that lowers pH of the media. Third way is to use X-gal plate where the inducer is also introduced along with bacteria. X-gal cleaves the ÃŽ ²-galactosidase enzyme then it is shown as blue. (1)(2) There are four ways to test lac phenotype we perform in this experiment. One is to use minimal lactose medium, and Lac- will not grow on the plate while Lac+ will. Second is to use MacConkey medium. Both Lac+ and Lac- can grow on the plate but only Lac+ will be pink on the plate because the fermentation of lactose by Lac+ produces acidic metabolites which lower the pH of the media and the pH indicator turns the plate pink. Third is to use X-gal plate which has IPTG as an inducer in the plate. Both Lac+ and Lac- can grow on the plate but only Lac+ will be blue. The last method is to use ONPG which turns yellow with ÃŽ ²-galactosidase, and units of enzyme activities are calculated. (3)(1) Material and Methods: All procedures are performed according to the BIOL 368 lab manual (Concordia Biology Department 2013) except for the following modifications: After adding ONPG, forgot to verify the colors. Results Part A. Growth of E.coli Cultures of E. coli were grown in flask containing liquid medium and containing solid medium with agar. E. coli in the plate that contains liquid medium was yellowish. Those were circular in shape and flat. The surface was smooth and opaque. When the bacteria was introduced to liquid medium, bacterial lawn was observed. These were small and rough. Some were not opaque, more like flat. Part B. Phenotypes of WT and mutant strains I. Auxotrophic mutants To examine auxotrophic mutants, JF1754 was used. This strain requires methionine, histidine and leucine. Therefore, we predicted that it will not grow on the media where all three amino acids are not contained. As predicted, JF1754 only grew on the medium with all three M, H and L amino acids. Grown JF175 was seen as white. This is because auxotrophic mutant requires all of the required nutrients to carry out the biosynthetic pathway. On the other hand, CAG12033 requires only a minimal media to grow which means in the minimal media, it is able to carry out the biosynthetic pathway. II. Antibiotic resistance In this part, strain EC5827 was used. Along with CAG12033, it was introduced to LB medium and LB medium containing streptomycin. As a result, EC5827 grew in both of the plates whereas CAG12033 did not grew in the plate with streptomycin. This is due to the fact that the strain EC5827 is resistant to streptomycin whereas CAG12033 is not. CAG12033 does not have the resistance, and therefore, it eventually did not grow on plate with streptomycin. III. The many colours of lac In min+ lactose: Strain NK6042 growth was not observed. This is because the lac operon was deleted from the chromosome of strain NK6042 and therefore, it cannot metabolize the sugar which prevents it to grow. On the other hand the wild type grew eventually. MacConkey Lactose: Strain NK6042 and wild type grew on the plate because this medium contains complex carbon source. The wild type is able to metabolize lactose and peptone and NK6042 can metabolize peptone only. However, they differed in color. NK6042 was white and the wild type was pink. This is because MacConkey medium contains pH indicator that turns pink under acidic condition. In addition, Lac+ acidifies the medium by fermenting lactose and by excreting the mixture of organic acids whereas Lac- does not. The result makes sense because wild type contains lac operon to produce Lac+ cells and NK6042 does not have lac operon. X-gal plates: Strain NK6042 does not appear as blue, it is just transparent whereas the wild type is totally blue. This is due to what X-gal does. X-gal cleaves the ÃŽ ²-galactosidase enzyme. Then, it turns blue. Therefore, it indicates whether or not the ÃŽ ²-galactosidase enzyme is produced. NK6042 is not able to produce ÃŽ ²-galactosidase since it has its lac operon removed. However, the wild type is still able to produce ÃŽ ²-galactosidase in the minimal medium, and as a result, its color turns into blue. Part C. ÃŽ ²-galactosidase assay The objective of the lab was to practice handling bacteria and learn methods that investigate phenotypes of bacteria. Table 3 shows the anticipated activity and respective volume of culture and z-buffer. There are three strains involved, CAG12033, MH321 and ML 308. Each of the strains are examined with and without IPTG. IPTG is an inducer where it binds the repressor that prevents the transcription. Then, repressor is no more able to repress. Therefore, inducer stimulates the transcription, and allows the production of -galactosidase. Low activity is expected without IPTG and high activity is expected with IPTG. In addition, cAMP level is expected to be low in presence of glucose so the CAP protein would bind to the promoter minimally. ONPG is used for quantitative -galactosidase activity in the sense that it breaks it into o-nitrophenol and galactose. When it turns yellow, it comes from o-nitrophenol. Looking at table 2, MH321 always has no activity because, lac Z gene is mutated, s o it cannot produce ÃŽ ²-galactosidase no matter what medium. IPTG only binds repressor and prevents it from repressing, so the inducer has no effect. On the other hand, ML 308 has a mutation in repressor. Most probably, it is ID and it works constitutively. Also, IPTG will not be able to bind this repressor, but this repressor does not prevent the transcription. Therefore, high activity predicted in any cases. Table 5 shows that the prediction is eventually correct. We have highest value for the low activity with CAG12033 without IPTG: 20.38 min-1 ml-1 Au-1. This is considered as low activity compared to high activity values we have and any other low activity predicted values have lower values than this. However, we earned low activity for MH321 where we predicted none. This is due to experimental error and this value is low enough to be considered as none. Therefore, our prediction for the low activity was precise. For the high activity, the highest value was found with the CAG12033 strain: 1506.4 min-1 ml-1 Au-1. With ML308, we have 570.4 and 767.4 min-1 ml-1 Au-1. These values are much bigger than the ones we have as low activities. They are enough high to be considered as high activity. For MH321, we got low activity because of the following reasons: mutation and contamination. One of the reasons that the mutant strains still have detectable activity is that the silent mutation might be occurred. That is, the mutation of a base does not change the amino acid sequence. Also, MH321 is the strain that has a mutation in lac Z and there may be some that still has lac Z activity. The other reason is the contamination, which is the most common source of error. The container might not have been washed enough, or microorganisms in the air may penetrated in the solution containing MH321. Speaking of the expected range, we expected the activity range from 1000 to 3000. However, our values are smaller: ML308 had 570.4 and 767.4 min-1 ml-1 Au-1.This is due to the fact that we did not have enough time for it to turn yellow, so, the values of the absorbance or optical density was lower than it is supposed to be. For part D, we have various mediums and various strains are used to predict which unknown is which strain. To figure out which is which, we made a table predicting in which medium the strain will grow or not. Looking at unknown 2, it only grows on Min M. We have the same with MH142 where it only grows with methionine plate. Also, both gives in MacConkey, white. Therefore, unknown 2 is supposed to be MH142. Because MH142 requires methionine to grow as an auxotrophic strain, it only grows in Min M. For unknown 3, the growth pattern matches MH807 and therefore, it should be MH807. With MacConkey plates, MH142 are lac- due to the white color presence of the plates. With the same principle, we figured that the unknown 5 is CAG8209 and 6 is CAG 18475. CAG8209 is tetracycline resistant and requires leucine and CAG 18475 has tetracycline resistance and requires methionine to grow. However, unknown 4 and 1 cannot be determined. They both have same growth pattern and also, both gives red color in MacConkey plate. They should be CAG12204 or D10. We need further test to identify which unknown is which strain. CAG12204 has kanamycin resistance whereas D10 does not. Thus, we can introduce this unknown to kanamycin+ minimal medium. If it grows, it is CAG12204 and if not, it should be D10. Finally, the result of unknown 7 strain matches none of the theoretically predicted result. It is due to the experimental error. We may have introduced some other unknown or solution in the medium that leaded to this error. Fortunately, it is the last unknown, and the last strain left is BW6165. So, it should be BW6165. BW6165 is only expected to grown in tetracycline and min R since it has tetracycline resistance and requires arginine to grow. However, it did not grow in our plate, therefore, if may have put something other than BW6165 by mistake such as CAG8209. In part E, SPO1 phage was introduced to E. coli and different concentration of B. subtilis cells. When B. subtilis was 10-folded and 100-folded, bacterial lawn was observed, so there were a lot of small and adjacent colonies. When it was diluted to 10-3 and 10-4, isolated colonies were found, 174 and 16 colonies respectively. We had 1.74*106 pfu titer. The section average was 1.75*106 and therefore, our value is very close to the section average. They are almost identical, and we can say that we successfully diluted and obtained proper colonies. In addition, when there was no phage and when 10-folded E. coli was plated in each plate, there was not a single colony found. This is because E. coli does not have the specific receptors for infection to occur by SPO1 whereas B. Subtilis does.

DHTML Lessons :: Technology, Informative

DHTML LESSONS Lesson 1 - Introduction What you should already know Before you continue you should have a basic understanding of the following: „X WWW, HTML and the basics of building Web pages „X Cascading Style Sheets „X JavaScript If you want to study these subjects first, go to our Home Page DHTML does not exist ! DHTML is an abbreviation for the term "Dynamic HTML". But DHTML is just a buzzword. DHTML does not exist. It is not a "thing" or a standard defined by the World Wide Web Consortium (W3C). It is not defined anywhere. It is just a fancy word. It is important that you know this (so you don't make a fool of yourself when you are talking with the pros). So what is DHTML? To most people DHTML means a combination of HTML 4.0, Style Sheets and JavaScript. W3C once said this: "Dynamic HTML is a term used by some vendors to describe the combination of HTML, style sheets and scripts that allows documents to be animated." The Elements of DHTML HTML 4.0 HTML 4.0 introduced two important things: Cascading Style Sheets (CSS), and the Document Object Model (DOM). Creating dynamic HTML documents would not be possible without these two additions. Cascading Style Sheets (CSS) With CSS we got a style and layout model for HTML documents. Creating dynamic HTML documents would not be possible without CSS. Document Object Model With the DOM we got a document content model for HTML documents. Creating dynamic HTML documents would not be possible without the DOM. JavaScript (and VBScript) With HTML 4.

The Tao Of The Joy Luck Club :: essays research papers

Taoism has been a major influence in China throughout much of its history and The Joy Luck Club, by Amy Tan, reflects this influence through its infusion of Taoist principals. One of the fundamental concepts within Taoism is that of Wu-hsing. Wu-hsing is a way of understanding a matter by dividing it into five and is often represented by five phases, elements of directions. This is an unfamiliar concept to a western perspective, which tends to divide things into four. Understanding this fifth additional element, however, is essential to understanding The Joy Luck Club. This fifth component is most clearly represented in The Joy Luck Club through the directional aspect, which is clearly represented at the Mah Jong table, which the women gather around at the Joy Luck Club meetings. Each of the women represent the direction which they sir at on the table and the center of the Mah Jong table represents the fifth direction. In Taoism this fifth direction is the harmonious center where the traditional four directions meet and from which they originate, it is their beginning and their end. In the book the Joy Luck Club meetings serve as this fifth dimension. It is in this fifth direction, the center of the women and the Mah Jong table where the game and story of the Hoy Luck Club is played out. As the game begins the women first â€Å"wash† the tiles in a chaotic mixing motion and then work together to structure these game tiles into an orderly creation in the center of the board (Tan 22). This is the effect of the fifth direction in the women’s lives as well. As the members of the Joy Luck Club bring the chaos of their lives and find peace through the combined effect of their relationships with each other. This process of bringing peace from the midst of chaos is first seen when the first Joy Luck Club is created in Kweilin. In Kweilin Suyun finds herself in an extremely chaotic and violent environment, which is the result of the refugee-camp-like city, and the frequent bombings, which it comes under. Suyun creates the club here as a source of peace in the midst of their troubles. The meetings become a place where the women do not discuss the eminent danger that surrounds them or their relatives and lives, which they have lost. Instead they focus on food and happy stories.

Compulsory Education Essay

Many may argue education is at its finest since things seem to get better with time; but is this the case when speaking of compulsory education? Compulsory education in the United States today has come a long way from original ideas concerning education. There are some satisfied with the way schools are constructed; yet there are others who are not. Much like anything else, compulsory education can be improved. According to Paul Goodman, requiring students to attain two years for maturing between high school and college can improve compulsory education (Goodman 2012). The history of compulsory education dates back to before the medieval era. As one may guess, compulsory education has been changed drastically since it was introduced. By the year 1918 all of the United States and territories had laws governing compulsory school attendance. Executing compulsory schooling allowed a more productive means of solidifying national school attendance. At this time, compulsory education is a form of progress setting the stage for more jurisdictions in state legislation regarding these attendance policies (Richardson 1994). Compulsory education has significant advantages and disadvantages. Compulsory education has great effects on enforcing children to go to school. Sadly enough, not all families want their children to go to school or be educated beyond a certain point; or for that matter, some children do not desire to continue their education. Fortunately, these attendance policies make children attend school up to a certain point, which depends on the state. The major disadvantage of compulsory education is that not everyone is â€Å"classroom material†. Some people prefer a being employed and establishing a steady income at an early age rather than going to school. A prime example of this is about a teenage boy, Charlie, was bored with school so he started skipping class for weeks at a time. Even then, Charlie proved to be successful in the landscaping business despite the substantial amount of time he lost in school (Inson 2006). Whether the effects of compulsory education are essential to one’s success or not, it plays a key role in today’s schools. Like anything else, compulsory education can and should be refined and enriched. Some of these ideas of improvement are shared by many but have not yet been enforced. The government should be more responsible for setting goals within the system and providing the infrastructure to do so. Also, the government should be responsible for analyzing the outcomes from students once these provisions are set (Yasuhiko 2005). Going further as to say, raising the age of compulsory education, which is an idea shared by many. This enforces students to continue their education for longer periods of time, which in turn, would ultimately provide more productive citizens to the American society (NASSP 2010). Certainly, compulsory education is a significant part of the history and present day schools. Education is everything in today’s society. There are immense advantages as well as disadvantages concerning this subject. Compulsory education is essential to schools in the United States and will continue to be. Continuous reform and amendments will be made along with new laws and policies governing compulsory education and attendance. Learning is a ceaseless process. Works Cited National Education at the Beginning of 2001. â€Å"Innovations and Developments in Education System†. 2002. Richardson, John G. â€Å"Compulsory School Attendance†. 1994. Inson, Peter. â€Å"The Guardian†. November 2006. Yasuhiko, Torii. â€Å"Redesigning Compulsory Education†. October 2005. < http://www. mext. go. jp/b_menu/shingi/chukyo/chukyo0/toushin/06051511. pdf>