Multicultural Case Study

MCE Problem Solving Case Study Section 1: Problem Identification The problem identified is gender bias that male students have towards female teachers. The conflict is many male students do not respond to female teachers the same way they respond to male teachers. These students feel that they do not have to follow directions/instructions from female teachers and will not complete assignments given without constant reminders. Male students who show this type of bias to female teachers are either from a single parent home, one where the female role is not respected, socialization of the student, or even a more affluent home.These students are not held responsible for their actions at home and feel that they are not accountable at school for their behaviors. Male students who come from single parent homes usually carry more responsibility at home and will attempt to carry this role over into the classroom. He feels that he is the more dominant member of the household and that he is alw ays in control. This student will not always complete assignments taken home because of his responsibilities and may or may not do well on quizzes and tests.He may feel that these assignments have no bearing on his current situation because he is more focuses on survival for today and less worried about the future. The male students who come from a home where the female role is not respected will carry this attitude over into the classroom. When he is presented a classroom situation with a male teacher he is respectful, but when placed a classroom with a female teacher he acts out or refuses to give her the proper respect. He feels that he superior to her and does not have to listen to her.Socialization of the student could also play a role in gender bias against a female teacher. The loud male student will always catch the attention of the teacher where as the quite soft-spoken female student will be overlooked. This attention can cause the male student to continue to act out in th at teacher’s class. A male student who comes from a more affluent home, the parenting comes in the form of money or gift giving. These students will hold a sense of entitlement in all situations causing them to feel that they are not responsible for their actions or behaviors.Even if corrected or punished at school they know that they will receive no punishment at home. They also realize that this provides a way out of that specific teacher’s class for a day or more. Section 2: Perspectives The first group affected by this problem is female teachers. These teachers begin to feel less confident in their teaching and begin to second guess themselves. It threatens the teacher authority level in the classroom when one student continues to disrespect, because it shows other students that they too can get away with it.After continual defiance or disrespect from students, teachers can begin to over react to situations that could be prevented with patience. Also, this disrupti on can prevent the teacher from accomplishing that day’s lesson because she is constantly correcting behaviors. Along with threatening a teacher’s authority these students can also cause fear in teachers. The next group affected is the male students. One effect could be the over generalization of all male students being placed into the same category as the defiant male students.This creates tension between the teacher and the entire male classroom population. This can also create a hierarchy between the males in the class by allowing the loud, defiant male to become the defacto leader, while the others follow. This action causes the teacher to lose control of the classroom, allowing that male to take control. The third group affected is the female students. The quiet, soft-spoken female will often be overlooked, while the dominant male will receive all the attention in the class.When the female students do well, they still do not receive the positive reinforcement they are due. After being exposed to this type of behavior the female students may begin to act out or defy authority figures because they feel that would gain more attention from the teacher. Also, seeing female teachers treated this way in the classroom can cause the female students to view this behavior as acceptable in everyday society. This can carry over into their lives, present and future. The fourth group affected by this problem is the parents of the students in the classroom.As a parent, you expect your child to receive an adequate education while in school, but if your child’s class is constantly disrupted they are not receiving an adequate education. The teacher may not be able to cover all curriculum scheduled for that allotted time because of student(s) being disruptive in the classroom. Also, if your child sees this behavior on a daily basis, he or she may begin to think that it is appropriate and may begin to mimic the behaviors. The last group affected is the sc hool.First, if the teacher is unable to cover the necessary material or teach the material effectively the school’s test scores may begin to drop and will cause them to not reach their Adequate Yearly Progress. The administration will have to focus more on discipline issues rather than on the positive aspects of the school. The effect may also be seen with other teachers and their view of that specific teacher or classroom. Section 3: Challenges and Opportunities One challenge for the teacher, parents, and school is the agreed upon level of reinforcement given to that student, whether it be positive or negative.A challenge to the teacher is not allowing that student’s behavior to effect her attitude towards the rest of the male population in her current class and in future in classes. Another challenge to the teacher is attempting to make up lost instructional time that was given up when dealing with the disruptive/disrespectful student. This can put stress on her and the other students. A challenge presented to the male student, is that if allowed to continually disrespect female teachers in school it will negatively affect his relationship with all female authority figures, police officers, bosses, and significant other, in his adult life.One challenge presented to the female student is to be acknowledged and appreciated for doing the right thing in and out of class. This can also apply to male students who respect the female teacher and her authority. An opportunity for the teacher would be for her to learn how to effectively manage her classroom and diffuse hostile situations. It allows the teacher to grow professionally in both the science and the art of teaching. All students have the opportunity to learn what acceptable behavior is in the school setting and this behavior will hopefully carry over into their adult lives.The school has the opportunity to create a culture of acceptable behavior and to create a learning environment that provid es an adequate education to all students. It also allows the school to create a precedent for future problems that may arise because of similar behavior issues. Section 4: Strategies †¢ Teacher could collaborate with other female teachers in order to get ideas about how to handle these situations. †¢ Do not ignore the problem, even if it seems small at that time. †¢ Set rule and expectations from day one. Let the students know that you are in control of the classroom. Develop a rewards system to reward student for positive behaviors. Take notice of successes in school or extracurricular activities. †¢ Give the student a daily job, in which he feels that he is important and is relied on. †¢ Involve as many outside parties as possible to help correct or improve behaviors. These parties could be parents, other teachers or coaches. †¢ Create a mentoring style program to provide the student with a positive example from an older student. †¢ The teacher m ay have to get administration involved if the behavior(s) a level beyond that teacher’s control.Section 5: Solutions The solution can be divided into three separate and distinct stages: 1. Proactive 2. Constructive 3. Reactive In the proactive stage, the teacher must show that she is in control of the room from day one and assert this authority to insure that the students understand the rules, policies, and expectations. She must have confidence in her abilities as a teacher. In this stage, she must also have her approaches and tools needed to handle violations of rules, policies, and expectations clearly defined.She must be consistent in the enforcement of the rules, policies, and expectations in the classroom. In the constructive stage, the teacher must respond quickly to any demonstrations of rude or disrespectful behavior and must be consistent in recognizing these behaviors. The teacher should respond to the student with positive feedback, provide guidance or correction for more appropriate. In the reactive stage, the teacher could first collaborate with other teachers and determine methods to prevent the behavior from occurring. She needs to also reiterate the rules, policies, and expectations of the class.Next, she could develop a rewards system to acknowledge positive behaviors from that student in her class. One possible reward could be for the student to have a daily task. This task could be handing out papers or taking the attendance to the front office. The task should make the student feel important and noticed by that teacher. Once it reaches the level where the teacher is unable to handle discipline in class, she needs to involve as many outside parties as possible. These can include coaches, parents, other teachers, and/or administration. Section 6: ExpectedThe solution gives each party impacted by the problem a fair and equitable opportunity to learn, teach, and be successful. The students are provided a safe and consistent learning env ironment, while being provided the rules, policies, and expectations of the classroom. This also provides the teacher with less stressful atmosphere that facilitates student learning. Section 7: Reflections Section 8: References Jana Bernhardt (2012). Am I Buggin Ya Yet? Dealing With Difficult Student Behaviors. [ONLINE] Available at: HTTP://thisisjustforfun. com/uploads/5227_NADE%20presentation. ppt25 Feb. [Last Accessed 25 February].

Journal Entry

Wing evolution has been a highly debated topic in insects. Wings play a crucial role for insects since they are used to assist with collecting food, migration, fleeing from predators, and many other activities. There are three main theories that have been thoroughly researched to help explain the evolution of wings. These theories include the parental origin of wings, the tracheal gill theory, and the exit-endive theory. The parental origin of wings hypothesis states that wings developed from parental lobes.When insects fell on the ground, nobles first acted like a racquet so the insect can land swiftly on its feet and scurry away from predators. As nobles grew larger they developed from gliders into wings. The main evidence behind this theory is the presence of broad thoracic onto and wing like pornographic lobes on fossils Of Ephemerals, Plenipotentiary and Appropriate that show venation and articulation (Whitfield 324).The tracheal gill hypothesis postulates that wings developed f rom tracheae gills since both were thin, membranous and mobile. Gills first started off for being used for breathing in oxygen, then used as fins to promote locomotion, ND finally modified the spiracles which reduced water loss to permit gliding which eventually turned into flying. Wigglers supported this theory by stating that wings and legs could be found in the thorax if it was originated by exits (Whitfield 325).The exit-endive hypothesis proposes Koala-Peck's theory about wings developed from exits that were found on many leg bases of early insects. Later, it was found that those insects also had endives. This theory was us ported by the fact that wings are originated from a structural feature that already had the necessary muscles, tendons and appendages of insects. This was later proven by the dismissal of Montana's theory that insect's legs are different than other arthropods legs (Whitfield 326). Live that the exit-endive theory seems the most plausible since it is most lik ely that wings emerged from endives and exits since those features were already present in insects. Also this theory has the most support compared to the other two theories and there are not many who oppose this theory. For the tracheal gill hypothesis to be true, the invasion of land would have to happen twice to accommodate for both insects with wings and without wings, Journal Entry On the news there was a story about a new museum being opened up in the American South that depicts the belief in creationism instead of evolution. Basically, this museum depicts human beings being created by God alongside dinosaurs and does not recognize that the Earth is older than 10,000 years old. Many people are protesting the museum because they feel that it perpetuates a religious belief as science and that it cannot be considered truthful and shouldn’t be viewed as a museum. I feel that this article is important because it shows how different religions and cultures can clash and different viewpoints can cause conflict amongst people. This news story, that I saw on CNN, has a central theme revolving around the fact that religion and science can cause conflict in a community. This was very interesting because of the fact this is the first museum to depict creationism as a science and because it is making such an impact in the community, with so many people protesting it because they feel it shouldn’t be marketed as science but as religion. This is important because both religious and non-religious people need to live side by side in our communities and it raises questions about how this can happen in terms of their beliefs about creation versus evolution, and how this aspect can help shape each of us depending on our upbringing and personal beliefs. Journal Entry # 2 The article â€Å"Trial set to begin in Mississippi civil rights-era case† by Jerry Mitchell appeared the USA Today on May 24, 2007 and deals with the case of a man who is facing charges for killing two African-American teenagers in 1964. This is an interesting article because it shows how much different our culture is today from the culture of the civil rights-era United States. Back then, white men were not punished for killing blacks, but today our culture and society have changed enough that we can look to make the past right to make a better foundation for the future. In the past few years there has been a push in Mississippi to bring to justice former klansmen and other racists who killed civil rights workers and African-Americans during a time and in a place where discrimination was so abundant that no one would convict them. This case is one of these, and is an interesting look at how the justice system can be corrupt and yet, today, we can try to make things right. This is so important today because of the issue of racism that is still there below the surface in many instances. Journal Entry # 3 The article â€Å"Gold Star wives help a new generation of war widows† that appeared on CNN.com on May 26, 2007 is an interesting look at the way that our own suffering can be a basis for helping others in similar situations. The article deals with the social issue of war and how it affects not only the people in the midst of the war but the wives, husbands, and children that are left behind by the men and women who die in the war in Iraq. This article is about a woman named Marie Speer who lost her husband in WWII and how she founded this organization called Gold Star Wives, which was established to help war widows in many various ways, from friendship and compassion, to helping lobby for benefits for the wives and husbands of those lost in the war. This story is applicable to the real world because of how our culture has been affected by the war in Iraq and how society looks at this conflict and the people affected by it. This is interesting because it shows how Americans are coming together and using their own experiences to help others and try to bring them through the pain of loss and grief. This is so important today because of the loss of connection many of us have in relation to each other. For example, many people cannot connect with people of other generations but in this article it shows how a WWII war widow has so much in common with a widow of a soldier in Iraq. It shows how we can all connect with each other on some level, and this is important in a country that lacks that. Journal Entry # 4 On Glenn Beck there was a story about how Rev. Al Sharpton, who had just finished recently lobbying to get Don Imus fired for his racial remarks regarding the Rutgers basketball team, had said something discriminatory about Mitt Romney’s Mormon religion. This is an important issue because so many people can look at this and see that so many people have underlying racism or discrimination about other people’s race, ethnicity, or religion. This is an aspect of our culture that has shaped each of us, depending on where we grew up and who raised us, as well as what our own experiences have shown or taught us. The central theme of this news story is that sometimes we can see discrimination within others more than we can within ourselves and that this needs to be an issue that is raised to each of us when it comes to light. This is very interesting in one aspect because those who thought that the media made too much out of the comments by Imus could say that Sharpton had no right to complain because he then becomes embroiled in his own scandal, but others can look at it from a different perspective and say that comments about race and religion are completely different and shouldn’t be equally compared. This is so important in our politically correct society because it begs an answer to the question about what is discrimination and when does free speech cross the line, and how has society viewed free speech and political correctness. Journal Entry # 5 The article â€Å"The First Steps† by Alex Tresniowski, et al, appears in the May 7, 2007 issue of People Magazine and is a look at the healing process that is happening at the Virginia Tech campus in Blacksburg, Virginia following the massacre that killed 33 students in Norris Hall on April 16th. This article is unlike many of the others because instead of dealing with the dark, brooding gunman or all of the mistakes and issues that led up to the shooting, it deals with how the students affected will take steps to heal and help create a better environment for all students on campus. This article was interesting to me because it was not just another doom and gloom article about the tragedy but point out what was being done right by the Virginia Tech students, faculty, and campus administrators to help the college heal. It was interesting to read the stories about these heroes and the terrible trauma that they went through during the massacre. It was also interesting to learn about how the community and society has come together to help create a safer environment at colleges and to help these students through the tragedy. Violence has become such a huge social problem in our society and this issue was made even more glaring by this particular school shooting. The article’s look at the counseling being offered, the changes in the college, and most especially the way that the community, parents, and students are all reaching out to each other as a means of healing is incredible. It also shows how they are hoping to eliminate loners and outcasts like the shooter by reaching out to their fellow classmates in need. Instead of dwelling on the bad, they are looking for something positive to come out of the tragedy.                Journal Entry Wing evolution has been a highly debated topic in insects. Wings play a crucial role for insects since they are used to assist with collecting food, migration, fleeing from predators, and many other activities. There are three main theories that have been thoroughly researched to help explain the evolution of wings. These theories include the parental origin of wings, the tracheal gill theory, and the exit-endive theory. The parental origin of wings hypothesis states that wings developed from parental lobes.When insects fell on the ground, nobles first acted like a racquet so the insect can land swiftly on its feet and scurry away from predators. As nobles grew larger they developed from gliders into wings. The main evidence behind this theory is the presence of broad thoracic onto and wing like pornographic lobes on fossils Of Ephemerals, Plenipotentiary and Appropriate that show venation and articulation (Whitfield 324).The tracheal gill hypothesis postulates that wings developed f rom tracheae gills since both were thin, membranous and mobile. Gills first started off for being used for breathing in oxygen, then used as fins to promote locomotion, ND finally modified the spiracles which reduced water loss to permit gliding which eventually turned into flying. Wigglers supported this theory by stating that wings and legs could be found in the thorax if it was originated by exits (Whitfield 325).The exit-endive hypothesis proposes Koala-Peck's theory about wings developed from exits that were found on many leg bases of early insects. Later, it was found that those insects also had endives. This theory was us ported by the fact that wings are originated from a structural feature that already had the necessary muscles, tendons and appendages of insects. This was later proven by the dismissal of Montana's theory that insect's legs are different than other arthropods legs (Whitfield 326). Live that the exit-endive theory seems the most plausible since it is most lik ely that wings emerged from endives and exits since those features were already present in insects. Also this theory has the most support compared to the other two theories and there are not many who oppose this theory. For the tracheal gill hypothesis to be true, the invasion of land would have to happen twice to accommodate for both insects with wings and without wings,

MAF202 Money and Capital Markets Assignment T1 2012 Essay

MAF202 Money and Capital Markets Assignment T1 2012 - Essay Example Hence, there has been widening of spread between cash rate and the interest rates set by the major banks. Banks have argued to such anomaly by mentioning that the rising costs of funds have led them to take such decisions. Since the Global Financial Crisis (GFC), banks have relied more on debt funding which are expensive sources of fund than equity and others. If we look at the recent global economic scenario, it can be found that the euro-zone crisis situation is still unresolved, and economic growth rate is expected to slowdown in 2012. There have been no rate cuts by the central bank of UK since 2009. In India recently there have been rate cuts by Reserve Bank of India and banks have started responding to it positively. Central bank of China follows a tightly regulated monetary policy and is expected to have rate cuts in 2012. Reserve Bank of Australia (RBA) is the central bank of Australia established in the year 2006. Its principal task is to control and regulate the monetary policy of Australia (Reserve Bank of Australia, 2012a). RBA uses cash rate as a tool to control the pressure of inflation in Australia. RBA targets to keep the inflation rate in and around 2% to 3%. This refers to the monetary policy followed by RBA. RBA’s monetary policy also includes curbing unemployment rate and assuring a stable economic growth of the country as its other objectives. When the inflation rate goes beyond the target of RBA, the cash rate is enhanced. Otherwise RBA tries to reduce the cash rate when it feels that inflation is not posing a great threat and Australia can have a faster economic growth. RBA regulates the monetary policy of Australia by setting up the lending rates on loans available in the money market on an overnight basis. These rates of interest set by RBA have an influence on the rest of the interest rates in Australian economy. Subsequently it has an effect on how the

The components of a firms image Essay Example | Topics and Well Written Essays - 500 words

The components of a firms image - Essay Example The goal is to manufacture product differentiation where no inherent distinctions exist. Retail positioning creates a value of "who you are" in the market. Store Image is the positioning of a store in terms of its branding, product selection, interior and exterior design, fixtures and fittings, lighting and other elements affecting the visual outlook of a retail store. Store atmosphere affects merchandise quality inferences, in turn affecting store image. Often, a consumer's first impression of a store is based on what can be seen or heard from outside the store. This may include the displays, the lighting, the music, the color scheme, and the arrangement of space. Merchandise Assortment is necessary to increase profitability which is the key driver for any business. Effective merchandising assortment and planning results in maximising sales potential and minimising losses from mark-downs and stock-outs. Effective merchandise planning and assortment effectively controls the two major areas of profit leakage in retail, which are the loss of sales due to stock shortage, and the forced margin reductions due to excess stock. The essence of computer aided direct marketing is that it aids in telemarketing; that is, selling over the telephone.

David Dabydeens Rewriting of Turners Painting Essay

David Dabydeens Rewriting of Turners Painting - Essay Example st enjoys the self-acclaimed freedom of distorting the reality in order to work out another reality that is greater and that lies beyond the capability of plain eyesight. J. M. Turner’s (who was an abolitionist) primary purpose was to draw the viewers’ sympathy for the slaves. But either because the limitation of visual art or simply because he is not one of the slaved society, he has failed to delve deep into the core of a slave’s existence that is his cultural identity. But Dabydeen has to focus primarily on this particular but relative truth or meaning of the art, rather than simply rewriting it, while overcoming Turner’s limitation. Yet since a visual art is often subjected to multiple interpretations depending on the multiplicities of individuals’ viewpoints, throughout the whole rewriting the painting Dabydeen has to maintain a poetic abstraction of the visual imagery of the his poem. Indeed, for Dabydeen Turner’s art is not more than an objective reality, of the 19th Century, and a part of history that he interprets from his own viewpoint. Hence what Dabydeen deals more with the reality of Turner’s art is his subjective interpolation that evokes picture and imagination of a civilization out of an instantaneous portrayal of a singular reality that might have evaded Turner’s eye, that is, J. M. Turner as well as his society fails to perceive the cultural identity of the slaves. Dabydeen has tried to evoke a cult ural identity out of the forgotten past. Dabydeen views that the slave thrown into the sea is floating for â€Å"centuries†, and his memory of his origin has faded away, though not completely.

Questions3 Assignment Example | Topics and Well Written Essays - 750 words

Questions3 - Assignment Example s a competitive advantage over others in the industry, the managers should carefully keep track of all the actions that have occurred and those which are anticipated too. The marketing calendars therefore come in handy to provide the managers with the opportunity to keep track of what it is expected to be done for the firm to attain a competitive advantage. Indeed, many organizations in the apparel or fashion industry use the marketing calendar to enable them to be able to network all the components existing in the company’s program. For instance, the companies use the marketing calendars to enable them plan their budgets thus helping them to avoid unforeseen expenditures. Moreover, the calendar prevents managers from engaging in â€Å"miss marketing,† prevents marketing lapses, and helps in staffing, planning and buying. The marketing calendar has three key components that should be put into consideration in order to make the company successful. The first component, Environmental Assessment, is the study of both the internal and external environment of the company so as to identify the various opportunities and threats which. Accessing the enables the company to establish the needs of the customers thereby enabling them to make necessary adjustments and improvements to meet these needs. The second component is Strategic Planning which is a continuous process of decision making that is based on methodical assessment of the environment in order to determine the action that the organization ought to do so as to attain a particular set of goals or objectives. In addition, since strategic planning is a blueprint for the company’s decision making, this component enables the staff to meet the various fashion needs of the customers. The last component is Implementation, which aims at clarifying the c ontribution of each department towards meeting the identified needs of customers. This component therefore integrates the marketing elements throughout the organization

Executive Diploma in Management Essay Example | Topics and Well Written Essays - 2000 words

Executive Diploma in Management - Essay Example In the following case the seven part model is applied to Southwest Airlines Strategy: Southwest Airlines has been in a business of low cost carriers operating .Their mission is to â€Å"To operate in a cost-effective and environmentally beneficial way while conserving environmental resources.†The mission of Southwest Airlines is dedication to the highest quality of Customer Service delivered with a sense of warmth, friendliness, individual pride, and Company Spirit. The competition included United Airlines and Continental Airlines. Although, railway and buses can be a substitute too. The strategy of Southwest thus revolves around this mission. It follows a low cost niche strategy with frequent flights in underutilized places and close in to a metropolitan. Southwest has simpler and cheap travel plans. The low cost strategy is followed by flying just one type of plane, the Boeing 737 series. That saves Southwest millions in maintenance costs, which includes spare-parts inventories, mechanic training and other nuts-and-bolts airline issues. SWA follows point-to-point flying. Most of the time it flies nonstop between two points. Costs are cut by less time that planes sits on the ground and also allows the average Southwest aircraft to be in the air for more than an hour longer each day. Southwests avoid-the-hubs strategy also pays dividends in the case of on-time operations. SWA has simple on-flight service. There is just one class of service on flight with no assigned seats. There are no meals just beverages and snacks SWA also follows a no frills, no fees. The airline only sells one-way fares and only in a few ranges of price. It keeps costs down and saves cost as complex fare structures are expensive to manage. Structure: The HR dept forms the bridge between all department ensuring cooperation and coordination between them. The department does an amazing job in continually feeding back information to employees

Price Analysis Essay Example | Topics and Well Written Essays - 500 words

Price Analysis - Essay Example The basis of certain agreed conditions such as the quality and the time taken to perform the contract determines the price. Some government contracting characteristics affect fair and competitive pricing. The characteristics are usually statutory and regulatory limitations. Decision to contract: This entails determination of need. Fulfillment of the standard of competition must be achieved when the contractor can conclude that the submission of the proposal adhered to expectation of competition. In order to predict the expected price of an acquisition we consider two components, the Purchase consideration and other costs directly associated with the acquisition (Drury, 2008). Purchase consideration includes assets exchanged, liabilities assumed, and Shares issued. Other costs include accounting fees, consultancy fees and legal fees incurred. Direct costs are production costs that can be directly identified and assigned to the final product. Indirect costs are general expenditures incurred for various or shared projects, activities and thus cannot be specifically identified with the final product. Direct costs can be allocated on the usage basis, time basis, effort basis, square footage basis and clients served allocation basis (Drury, 2008). Indirect costs maybe identified as fixed costs, and their allocation is usually easy. This includes salaries and wages allocation to managers and other personnel not directly engaged in the production process. Rent and office supplies are charged to each department. In this department, machines and other fixed assets undergo depreciation. Cost analysis is the examination of distinct elements e.g., labor that constitute a contractors total cost proposal or the price to determine if they are appropriate (Murphy, 2009). Whenever one is, comparing lump sum prices the use of the cost and price analysis becomes essential.

Turbines Case Essay Example for Free

Turbines Case Essay Definition and historical background Claude Burdin (1788–1873) was the very first person to use the word turbine. The word came from the Latin term turbo/turbines, which means a â€Å"whirling† or a â€Å"vortex.† Burdin used the term to describe the subject matter of an engineering competition being held during that time for a water power source. It would be an oversimplification to describe turbine as a rotating machine that is used to derive power or electricity from the water; a common water wheel may not immediately or necessarily be a turbine, but it definitely is a rotating machine. A more precise definition of a turbine is that it is a machine â€Å"in which the water moves relatively to the surfaces of the machine, as distinguished from machines in which such motion is secondary, as with a cylinder and piston† (Daugherty and Franzini 1965, 213–214). More broadly, to include other types of turbine, it is one of those devices or machines that is being used to channel or convert energy from a stream of fluid (liquid or gas) into mechanical energy which would eventually be used to generate electrical energy, or to support or augment another utility/device. This is done as the stream passes through a system of fixed and moving fanlike blades which causes the latter to rotate. This device (turbine) looks like a large (and sometimes small) wheel with small radiating blades around its rim. The four general classes of turbines are water or hydraulic, wind, steam, and gas turbines. Water or hydraulic, wind, and steam turbines are generally used for the generation of electricity; while the remaining one, gas turbines, is mostly being used in aircrafts (Britannica Concise Encyclopedia 2006). The principal components of simple turbines are the rotor, which in most if not all cases has blades projecting radially from the center to its periphery; the nozzles, where the working jet of fluid is directed and expanded; and blades, where the conversion of kinetic to mechanical energy takes place. Theoretical and operating principles Potential and kinetic energy both exist in a working fluid, which could be compressible or incompressible. Turbines collect this available energy by utilizing any or both of these physical principles: impulse turbines and reaction turbines. Impulse turbines change the direction of flow of a given high velocity fluid jet. The impulse, as a result of this, causes the turbine to spin or rotate, diminishing the kinetic energy of the fluid flow as this is absorbed by the device. In the case of flowing water, it comes available in purely mechanical form (water in nature is one of the most useful and efficient sources of kinetic energy). Scientific calculations show that 1 cubic meter of water can actually produce 9.8 kilojoules of pure mechanical energy for every meter that the volume of water descends. In the same way, a flow of the same volume of water for every second in a fall of 1 meter can provide 9.8 kilowatts, or 13 horsepower. Hydraulic turbines efficiency is estimated at approximately 1, meaning, almost all energy is available or utilized. This kinetic/mechanical energy can be converted to electrical energy with an efficiency of more than 95.0% (Calvert 2004). To get this much power from water, it should be extracted as it is lowered in elevation. The current in a stream, of course, is obvious. This flow comes from the open-channel movement or flow of water as influenced by gravitational forces. Simply put, holding a paddle-wheel in the stream of water will result to the paddle-wheel being rotated and from this outcome, power can be extracted (mechanical energy or electrical energy). This is an example of elementary impulse turbine, a machine acted upon by the impulse or force of moving or flowing water (Calvert 2004). In the case of reaction turbines, torque is developed as a result of fluids pressure or weight. The fluids pressure changes as it goes through the rotor blades of the turbine. There should be a pressure casement so as to contain and maintain the energy of the working fluid as it acts on the turbine stage(s). If there would be no pressure casement, the turbine must be immersed in the fluid flow, such as in the case of wind turbines. It is the casing that directs and contains the working fluid. In the case of water turbines, it maintains the suction which is imparted by the draft tube (Calvert 2004). A simple but very good example for this principle is the lawn sprinkler. In contrast to the impulse turbine, where the pressure change took place in the nozzle, the pressure change in reaction turbines occurs in the runner itself. This happens at the time that the force is exerted, hence, a reaction. Looking at the example of sprinkler, its duty is to spread water coming from it; the resulting energy from the turbine serves to move (rotate) the sprinkler head. Water flows from the center of the sprinkler going radially outward. Water under pressure comes from the center, and then jets of water that can possibly cover the area go out to the ends of the arms of the sprinkler at zero gauge pressure. The significant decrease in pressure takes place in the sprinklers arms. The water is projected at a certain angle to the radius, but it should be noted that the water from a working sprinkler actually moves along a defined radius. The jets of water do not impinge on a runner; but rather, they leave the runner, and this momentum is not converted into force, as opposed to an impulse turbine. The force residing on the runner reacts to the creation of the momentum, hence, the principle itself, reaction turbine (Calvert 2004). In any case, there is no restriction, as far as laws of physics are concerned, for any machine to utilize both principles. Many machines or devices use both of these principles as it is more efficient for the machine to be that way. Different kinds of turbines There are different kinds of turbines used in modern period: the water or hydraulic, steam, gas, and wind turbines. There are other types but these four are the most common and are usually the bases of any other turbines. Hydroelectric power stations utilize water, or hydraulic, turbine to drive their electric generators. Wisconsin, in 1882, witnessed the first of this kind of turbines. The processes taking place in a hydraulic turbine is simple: falling water hits a set of buckets or blades connected to a shaft. This impact will cause the shaft to rotate and move the rotors of the generator. The most common kinds of hydraulic turbine are the Francis turbine, Pelton wheel, and the Kaplan turbine. Two engineers, Sir Charles A. Parsons and Carl G. P. de Laval (of Great Britain and Sweden, respectively), pioneered the building of hydraulic turbines during the late 19th century. Continual developments and improvements of basic machines made hydraulic turbines to be the main power sources utilized to drive most large electric generators (Reynolds 1970). Another kind of turbine is the steam turbine. This is typically consist of conical steel shell that encloses a central shaft wherein a set of bladed disks are placed like washers. These blades are bent and extend outward (radially) from the edge of each disk. Some steam turbines have shafts that are surrounded by a drum wherein the rows of blades are attached. In between each pair of disks, there is a row of stationary vanes that are attached to the steel shell. These extend radially inward. Each set of vanes together with the bladed disk immediately situated/placed beside it constitutes one stage of the steam turbine. Most steam turbines have multistage engines (Columbia Electronic Encyclopedia [Online edition], 2007). Steam turbines are used mostly for electricity generation in thermal power plants, (i.e., plants using fuel oil or coal, or nuclear power). Steam turbines were once used to drive mechanical devices such as in the case of ships propellers. However, most such applications now utilize an intermediate electrical step or reduction gears. Gas turbines are now used mostly for aircraft engines. But there are still some gas turbines being used to drive electric generators (i.e., in an electric–gas turbine locomotive) as well as high-speed tools. The essential components of a gas turbine are (a) compressor, (b) combustion chamber, and (c) turbine that somehow resembles that of a steam turbine (refer to the description in the previous paragraph). The compressor is driven by the turbine, and then provides high-pressure air into the combustion chamber. In this chamber, the high-pressure air is mixed with a fuel and then burned. This makes the high-pressure gas(es) drive the turbine, with the same gas(es) expanding until their pressure decreases and reaches atmospheric pressure (Columbia Electronic Encyclopedia [Online edition], 2007). The last kind of turbine is the wind turbine, which as the name suggests converts the kinetic energy coming from the wind into mechanical and/or electrical energy. If the resulting mechanical energy is directly used by a nearby or even attached machinery (e.g., pump or grinding stones), the turbine device is usually referred to as a windmill. But if this mechanical energy is used to generate electricity, then, the device is called a wind turbine, wind generator, or wind energy converter (WEC; Reynolds 1970). Wind turbines can be three-bladed, two-bladed, or even one-bladed (counterbalanced). Computer-controlled motors point them to the direction of the winds. Danish turbine manufacturers have utilized the three-bladed turbine type. This type of wind turbine has high tip speeds (even reaching up to 6 times the speed of the wind), low torque ripple, and high efficiency, which contributes to the overall good reliability. This type of turbine is the one that is being commercially used to generate electricity. In many cases, the blades are colored in such a way that it blends with the clouds. The length of these blades usually ranges from 20 to 40 meters (or about 70 to 100 feet) or more, while the height is about 200 to 295 feet. Contemporary wind turbine models rotate at a speed of 16.6 rpm (revolution per minute). As a safety precaution to avoid overspeed damage, most wind turbines are equipped with automatic shutdown features during strong winds (Reynolds 1970; Wikipedia, The Free Encyclopedia 2007). There are other kinds of turbines, albeit fewer and smaller ones, in existence. These are the transonic turbines, contra-rotating turbines, statorless turbines, ceramic turbines, and shroudless turbine. Other uses of turbines Almost all electrical energy being used on Earth is generated with any one of the turbines discussed. Turbines with high efficiency can harness approximately 40% of the produced thermal energy, with the rest of the output exhausted as waste heat. Turbines are being utilized by most jet engines to provide mechanical energy from their fuel and working fluid as do most, if not all, power plants and nuclear ships. Reciprocating piston engines (like those found in aircraft engines) can utilize a turbine to drive an intake-air compressor. This configuration is known as the turbocharger (or turbine supercharger) or more colloquially known as â€Å"turbo.† Most turbines are capable of having very high power density the ratio of power to volume, or power to weight. This is due to their ability to function at extremely high speeds (Wikipedia, The Free Encyclopedia 2007). As of yet, no one has established any limitation for this invention of humankind. And with enough research and development, the present capability of these machines can even yield astonishing achievements. Woks Cited Calvert, J. B. â€Å"Turbines.† Date accessed: November 29, 2007 (http://mysite.du.edu/~jcalvert/tech/fluids/turbine.htm). Daugherty, R. L., and J. B. Franzini. Fluid Mechanics. 6th ed. New York: McGraw-Hill, 1965. Reynolds, J. Windmills and Watermills. New York: Praeger, 1970. Strandh, S. A History of the Machine. New York: AW Publishers, 1979. â€Å"Turbine.† Britannica Concise Encyclopedia. Encyclopedia Britannica, Inc., 2006. Date accessed: November 29, 2007 (http://www.answers.com/topic/turbine). â€Å"Turbine.† The Columbia Electronic Encyclopedia. 6th ed. Columbia University Press, 2003. Date accessed: November 29, 2007 (http://www.answers.com/topic/turbine). â€Å"Wind turbine.† Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. Date accessed: November 29, 2007 (http://en.wikipedia.org/w/index.php?title=Wind_turbineoldid=173495357).

Blood clotting enzyme Essay Example for Free

Blood clotting enzyme Essay Serine protease proteins are important enzymes involved in the process of blood coagulation. Blood coagulation is an importance defense mechanism that prevents the host mammal organism from losing excess blood or from forming unwanted blood clot. The process of coagulation can be initiated by both intrinsic factors and extrinsic factors. A cascade of event is followed which activate these enzymes; normally the enzymes are inactive state a condition called zymogens. Zymogens by their virtual condition of being inactive prevent unwanted blood clotting which may have a far reaching consequence such as thrombosis. Blood clotting in a series of processes, in which the zymogens’ need to be activated by reacting with its glycoprotein co-factors. Among the serine protease is the thrombin enzyme factor five (v) responsible for clearing clot in the blood. The enzyme is usually present circulating in plasma which is made up of a single monomer chain, it life span can range from 12 to 36 hours. In human the main regulator in blood coagulation is erythrocytes leukemia cells which activate adenylate cyclase, the process is reversible by the interaction of Aalpa-thrombin with glycoprotein while b alpha enhance the platelets interaction which initiate the proteolytic process. Fibrin-bound thrombin is cleaved by thrombin at a very specific site at the extracellular N-terminal, PAR-1 regulates a number of endothelial cell biology, vascular development but more so is a mediator of thrombin signaling. The human thrombin consist of two gamma chains namely the gamma A and gamma’ the final stage of coagulation of mammalian blood involves the cleavage of the four arginine and glycine bond. Binding studies shows both fibrin 1 and fibrin 2 with low affinity to the E domain and high binding affinity at the extreme end of 408 to 425 on the gamma chain The mode of action involves conversion of fibrinogen to fibrin by breaking the bonds in the fibrinogen at a precise position of arginine and glycine where the fibrin peptides are released. The serine proteases require restructuring itself in order to fit the key and lock model. The glycine at the position five is highly conserved because it is the one which occupy the active site which is determine by the acryl group during the substrate conformation. Asparagines 189 help the enzyme to easily recognize the substrate. The active site is entirely made of histidine 57, asparagines 102, serine 195 and serine 214. The reaction on many a times prefers position 1 to position 4 during remodeling, therefore the type of protein presence to a large extend determine the kind protease and also the kind of cleavage to take place. Thrombin activation is regulated by pentapeptide of the COOH terminus of the factor (v) heavy chains. Thrombin and thrombin receptors is another regulatory point where they both posses strong protective barrier and at the same time cancerous cells were eliminated by apoptosis. A study carried out using mitochondrial membranes which were depolarized using attenuated Catalase lead to controlled cell death. Statistical finding indicate that 30% of the population carried world wide indicated that activated peptide segment at position 4 of factor eight caused a substitution in V34L after binding the structure and analyzing the interaction according to (Brenda 2010). The switching of receptor is PAR-1-dependent signaling specifically to thrombin resulting inhibition of adhesion cell surface which activate thrombin the ligand occupancy position switches the protease receptor by signaling specifically to the thrombin. Human cell in culture indicated low amount of thrombin and receptor PAR-1 agonist induced strong anti-inflammatory activities which was secondary effect of the low concentration of thrombin after activation by P13 kinase and PAR-1. Thrombin like other enzymes is very specific in the binding domain and the insertion loop which is determined by the residues involved in ligand binding as result of interaction glycoprotein and protease receptor on the platelet membrane. This uniqueness makes it very efficient in it task according to (Webert 2006). The enzyme play vital role in homeostasis, cell differentiation, thrombosis and activation of blood cell types, on exposure to phosphatidylserine on the outer surface the platelets were stimulated. A study done using heparin indicated an overlap of the active site, which was attributed to the interaction of thrombin and the gamma peptide chains to the external and the interaction to the active site in close proximity to the Na+ of the substrate. The role of the enzyme can be explained in terms of NA+ binding to thrombin on the basis of prothrombotic and procoagulant. The cascade is a continuous cycle of events that are activated by two factors ,factor (ix) and factor (viii) to form tenase complex which is discontinued by down regulation that occur in the following mechanism which include; serpin (serine protease inhibitors) which function to degrade thrombin and other activation factors, it can also be regulated by protein C where thromodulin bind to it and is inactivate in the presence of protein S, limiting the action of tissue factor by the tissue factor pathway inhibitors by inhibiting excessive TF mediated activation of factor (ix) and factor (x), plasmin help to degrade fibrin hence preventing more fibrin being formed and lastly but not the least regulation through adenylate cyclase pathway by inhibiting platelet activation by decreasing cytosol level of calcium which ultimately result to decreased release of granules which are responsible for the activation of more platelets and coagulation cascade. In conclusion the work play by thrombin enzyme is of paramount importance considering the complexity of the enzyme kinetics involved in the human body. References Brenda Enzyme database retrieved on 13 August 2010 from http://www. brenda-enzymes. org/php/result_flat. php4? ecno=3. 4. 21. 5 Furie B, Furie BC (2005). Thrombus formation in vivo. J. Clin. Invest. 115 (12): retrieved on 12 August 2010 from http://www. jci. org/cgi/content/full/115/12/3355. Webert KE, Cook RJ, Sigouin CS, (2006). The risk of bleeding in thrombocytopenic patients with acute myeloid leukemia. haematologica .