The Striking Issues that Gave Light to Richard Wright’s

Issues on rebellion, racial discrimination, and social hierarchy have been considered as the finest works in the field of literature and history.   Stories that portray the truth behind the raging diversion between the whites and the blacks have always been a topic of speculation that writers and scholars considerably digest inside the situation.   It does not only come in handy—especially in narrative anecdotes—but it also serves as a â€Å"by hook or by crook† schema in the aide of social and political instances in the contemporary society. Numerous scholars even reprimanded Wright’s works as to be a mere social document rather than that of a novel in the catalogs of literature.   Debates have sprouted and critics commenced deliberative studies on the credibility of the author’s works (Kinnamon). Personal experience and observation—these are the customary perceptions regarded by a milieu of academia; and that   no matter how rigid Wright’s arguments are on introducing his work as a â€Å"fiction,† the social circumstances which have been brought upon by the readers tingled the minds of skeptics all the more. Charles I. Glickberg even theoretically stresses that the representation of Bigger Thomas is the author himself, and that the experiences and the events which occurred on the story are in point of fact the author’s own lifespan familiarity. As James Baldwin articulates, â€Å"no American Negro exists who does not have his private Bigger Thomas living in the skull,† crazed to be logically the same from one another, the audience have spotted the similarities.   From geographical representation, to familial connection—mother in the most awful slums of the Black Belt of such locale—characteristics with regard to motivation in overcoming fear and detestation, the temperament of being rebellious and the explosion of violence as triggered by the environmental and societal experiences diverged on to. Further, in the Southern custom, the portrayals in Bigger’s role all proved several connotations of the realistic sense in the crowd where the author actually lives.   Supplementary to that, all of them were mutinous colleagues of the Jim Crow order, â€Å"they were shot, hanged, maimed, lynched, and generally hounded until they were either dead or their spirits broken,† all these were the exact depiction of Chicago’s timid, twitchy, glum disturbed, estranged, vicious youths besieged for survival individuals.   The reality, which has been established in the story dwells on the analogy that Richard Wright’s intentions in producing the book follows the idea of â€Å"telling the truth.† (Kinnamon) The climax of the story is apparently seen on the last part, where he stood and expressed what has been boggling on his mind.   As Bigger stated, â€Å". . .I speak for my own people, but I speak for America too,† such striking phrase makes the readers realize that the story does not only tackle the negative descriptions of the discrimination that Negroes are experiencing, but rather the events came in a domino effect with pious misunderstandings between both sides of the coin. â€Å"Bigger† can be considered as a hero and as a model to the Americans (Kinnamon).   In a broader perspective, it implies that change has to be done for the betterment of all.   Hence if the act has been a second later, the predicament of the whole situation never would have been saved, or redeemed. Undeniably, the twists of the story complete its whole package.   It does not only take readers into a whole new dimension in the arena of fictional stories, but because of Wright’s indirect representation of its characters, it has captivated the hearts of the masses.  Ã‚   Others make be cynical on the relevance of reading the book—looking on the inconsiderate part of course—but those who well understood the theme and the manifestations which has been introduced by the author even until the very end of the story, it mystifies one’s thoughts and belligerently makes a certain bookworm think, â€Å"have I been a good citizen?†Ã‚   That then make be deemed as a perfect mixture of thrill and admiration.   It may be ideological in the immediate time, but no one knows where the Native Son shall settle next. Work Cited Kinnamon, Keneth. â€Å"Native Son: The Personal, Social, and Political Background.† Phylon (1960-) 30.1 (1969): 66-72.      

Digital Fortress Chapter 16

â€Å"A ring?† Susan looked doubtful. â€Å"Tankado's missing a ring?† â€Å"Yes. We're lucky David caught it. It was a real heads-up play.† â€Å"But you're after a pass-key, not jewelry.† â€Å"I know,† Strathmore said, â€Å"but I think they might be one and the same.† Susan looked lost. â€Å"It's a long story.† She motioned to the tracer on her screen. â€Å"I'm not going anywhere.† Strathmore sighed heavily and began pacing. â€Å"Apparently, there were witnesses to Tankado's death. According to the officer at the morgue, a Canadian tourist called the Guardia this morning in a panic-he said a Japanese man was having a heart attack in the park. When the officer arrived, he found Tankado dead and the Canadian there with him, so he radioed the paramedics. While the paramedics took Tankado's body to the morgue, the officer tried to get the Canadian to tell him what happened. All the old guy did was babble about some ring Tankado had given away right before he died.† Susan eyed him skeptically. â€Å"Tankado gave away a ring?† â€Å"Yeah. Apparently he forced it in this old guy's face-like he was begging him to take it. Sounds like the old guy got a close look at it.† Strathmore stopped pacing and turned. â€Å"He said the ring was engraved-with some sort of lettering.† â€Å"Lettering?† â€Å"Yes, and according to him, it wasn't English.† Strathmore raised his eyebrows expectantly. â€Å"Japanese?† Strathmore shook his head. â€Å"My first thought too. But get this-the Canadian complained that the letters didn't spell anything. Japanese characters could never be confused with our Roman lettering. He said the engraving looked like a cat had gotten loose on a typewriter.† Susan laughed. â€Å"Commander, you don't really think-â€Å" Strathmore cut her off. â€Å"Susan, it's crystal clear. Tankado engraved the Digital Fortress pass-key on his ring. Gold is durable. Whether he's sleeping, showering, eating-the pass-key would always be with him, ready at a moment's notice for instant publication.† Susan looked dubious. â€Å"On his finger? In the open like that?† â€Å"Why not? Spain isn't exactly the encryption capital of the world. Nobody would have any idea what the letters meant. Besides, if the key is a standard sixty-four-bit-even in broad daylight, nobody could possibly read and memorize all sixty-four characters.† Susan looked perplexed. â€Å"And Tankado gave this ring to a total stranger moments before he died? Why?† Strathmore's gaze narrowed. â€Å"Why do you think?† It took Susan only a moment before it clicked. Her eyes widened. Strathmore nodded. â€Å"Tankado was trying to get rid of it. He thought we'd killed him. He felt himself dying and logically assumed we were responsible. The timing was too coincidental. He figured we'd gotten to him, poison or something, a slow-acting cardiac arrestor. He knew the only way we'd dare kill him is if we'd found North Dakota.† Susan felt a chill. â€Å"Of course,† she whispered. â€Å"Tankado thought that we neutralized his insurance policy so we could remove him too.† It was all coming clear to Susan. The timing of the heart attack was so fortunate for the NSA that Tankado had assumed the NSA was responsible. His final instinct was revenge. Ensei gave away his ring as a last-ditch effort to publish the pass-key. Now, incredibly, some unsuspecting Canadian tourist held the key to the most powerful encryption algorithm in history. Susan sucked in a deep breath and asked the inevitable question. â€Å"So where is the Canadian now?† Strathmore frowned. â€Å"That's the problem.† â€Å"The officer doesn't know where he is?† â€Å"No. The Canadian's story was so absurd that the officer figured he was either in shock or senile. So he put the old guy on the back of his motorcycle to take him back to his hotel. But the Canadian didn't know enough to hang on; he fell off before they'd gone three feet-cracked his head and broke his wrist.† â€Å"What!† Susan choked. â€Å"The officer wanted to take him to a hospital, but the Canadian was furious-said he'd walk back to Canada before he'd get on the motorcycle again. So all the officer could do was walk him to a small public clinic near the park. He left him there to get checked out.† Susan frowned. â€Å"I assume there's no need to ask where David is headed.†

A Raisin in the Sun Essay -- Character Analysis, Walter

Big Walter had lots of values for his race and worked very hard for those values to ensure happiness for his family. The American dream was a dim reality because of the harsh working conditions of Chicago blacks in the 1920’s (M’baye 175). This is how mama sees Big Walter, as a courageous man who fought all his life to secure a happy future for his family. As M’baye states, â€Å"Big Walter’s life was a constant struggle against a personal sorrow and a hostile economic and social world that discriminated against him† (175). Big Walter has the most dignity for his family and his actual dream is the happiness of his family. Mama always mentions Big Walter in the story every time Walter or Beneatha does something that she thinks is wrong. Mama says that Big Walter hated domestic jobs and that farming and sick people—then go be a nurse like other women—or just get married and be quiet† (Hansberry 38). The value of every dream is crucial to every member of the Younger family because of the effect it has them, but it is the family dream to own a house that hold them together. At the end of the story, Mama convinced Walter that buying the house was important for the family because the thought of living in the apartment for the rest of their lives was unbearable. Big Walter had to fight and was struggling to achieve his dream of buying a house, which ended up becoming the families dream. Walter’s dream interfered with Beneatha’s dream, and the families dream. This had a major impact on everyone’s life, especially after Walter lost the money. In the end, the Younger family was all happy about Walter’s decision. That is the Younger family American dream.

Paraphrasing Essay Example | Topics and Well Written Essays - 500 words - 3

Paraphrasing - Essay Example The pumping station will be self-sufficient and require no external power to pump the water to the reservoir tank. Fuel Cell is a system that can transfer the chemical energy to electrical energy. That means to convert the reaction between hydrogen and oxygen to get electricity. These processes do not produce any air pollution. Hydrogen gas helps a lot in the pump station, because it can produce energy by reacting in fuel cell with oxygen to produce electricity. It acts as a basic material in this Remote Pumping Station System Project because it can generate power. The context diagram (Figure 3 in Attachment) gives the necessary information that we need to calculate to redesign the project. This diagram makes it easier to find out which formula we are going to use in calculations. Experiment 1 (Table1 in Attachment) was to determine the angle of the solar panel. We used the load measurement box of the rotary switch. We set the protractor handout at angel 0. Then we adjusted the solar to the lamp. We had to consider the distance between the solar and the lamp like 50 cm. After that, we wrote down the current (A) in CW (+) and CCW (-) in different angles between 0 and 90 by turning the solar. Experiment 2 (Table 2 in Attachment) we were able to measure the amount of hydrogen created by the electrolyte. We observed the level of hydrogen created, after each 2 ml increment on the cylinder; we wrote down the time it took to reach this increment with the current and voltage. We continued writing down the time until 10 ml of hydrogen was produced. Experiment 3(Table 3 in Attachment) was to determine the fuel cell consumption efficiency. This experiment looked like experiment 2, both of them done by creating hydrogen. When hydrogen had reached 10 ml, the light source turned off. In this time, their would be the electrolyzer storage gas in the storage cylinder. We used several formulas to get the right data for this project. The first calculation was

Compare and Contrast the reigns of Kangxi and Yongzheng Essay

Compare and Contrast the reigns of Kangxi and Yongzheng - Essay Example Yongzheng Emperor was born Yinzhen between December 1678 and October 1735 was an emperor of Manchu Qing Dynasty and ruled China between 1722 and 1735.2 He was nurtured by his father Kangxi in his childhood. This document explores similarities and different challenges Kangxi and Yongzheng emperors faced during their reign and their responses to the differences. Both emperors were religious and followers of Confucianism. They dedicated their lives to serve their people. They were careful to practice virtues because they believed such practices could bring good luck. For example, Kangxi believed that all present issues should be resolved in the present time to avoid the piling up of issues that may turn onto impediments in the future. He avoided being reckless with the public resources and ensured he spend the public wealth carefully.3 They both emphasized on morality and set the moral standards for their people to ensure they lived morally upright. For example, Kangxi established a version of moral standards known as Shengyu guangxun based on sixteen maxims. Later, his son Yongzheng expanded the sixteen maxims in another version known as Shengyu guangxun zhijie in literary Chinese order to make it easier for the people to follow. Kangxi and Yongzheng viewed well-organized clans and families as the prototypes of orderly states.4 Both emperor s experienced resistances from the central government and the followers of other regions such as Daoism, Buddhism, Catholicism and the folk religion. In his practices Kangxi promoted discrimination by abolishing â€Å"musical households of Yangzhou during his reign.† However, Yongzheng brought reforms that eliminated legal discrimination which gradually diminished the harsh social discrepancies of the former regime he considered evil. For example, he eradicated the â€Å"hereditary status of household slave and retainers in Nigguo and Huizhou prefectures in Anhui in 1727.†5 During the reign of

Why is the conviction rate for rape so low in the United Kingdom Dissertation

Why is the conviction rate for rape so low in the United Kingdom - Dissertation Example More often than not, the prosecution and defence parties know each other, making the witness accounts more likely to involve some bias. Despite this, it is suggested that the United Kingdom has some of the best training in the world for officers dealing with rape cases, with a huge number of restrictions and guidelines in relation to these cases. However, the conviction rate for rape still remains extremely low, especially when compared with that of other physical crimes. The Association of Chief Police Officers lead for rape has suggested that this might be because the training is often ignored, perhaps due to the personal nature of rape cases. The purpose of this investigation is to critically review the available literature on the topic to ascertain further reasons why this conviction rate is still so low for cases of rape. This will provide material to evaluate the situation for rape victims (and those falsely accused of rape) in the U.K. and perform a critical reflection on the subject. This material will be used to show that it is the very nature of rape that ensures the conviction rate remains at this low percentage, although changes in procedure may help the proceedings in some cases. Definitions and Types of Rape Perhaps something that makes cases of rape more likely to go unprosecuted is that the definition of rape changes between individuals and between organizational bodies. This could have a number of consequences, not least being that jurors may have differing opinions that make prosecution difficult. The United Nations (UN) definition of rape is ‘sexual intercourse without valid consent’6, which in the United Kingdom includes minors under 16 years of age who are not legally able to give ‘valid consent’. The World Health Organization (WHO) suggests that rape is ‘physically forced or otherwise coerced penetration – even if slight – of the vulva or anus, using a penis, other body parts or an objectâ€⠄¢7, again focusing on penetration being the definitive act. Some feel that this is exclusive of those who experience sexual misconduct without penetration. Within the United Kingdom, the Sexual Offences Act 2003 defines rape as an act which can only be carried out by a man, must involve penetration and this man must not reasonably believe that there is consent.8 This is the definition that will be used throughout this essay, as it is useful from a legal context, despite the social issues that it may provoke. Rape & Prosecution Rates in the United Kingdom The Home Office publishes statistics on rape cases, which provide a useful basis for any research on rape in the United Kingdom. The following figures do not include statutory rape; all the cases reported here are by male and female victims aged between 16 and 59. This gives the rate of rape and attempted rate for 2006 as about 0.5% of women in the 16-59 age group, or one in every 200 women9. When cases of attempted rate are exclud ed, the rate remains high at 0.3%. Overall, the best estimate for sexual assault crimes was that it affected It was reported that 53% of cases of serious sexual assault against women were caused by a partner (a complicating factor that will be discussed below), whilst in men the most common

Management of Design and Innovation Essay Example | Topics and Well Written Essays - 6000 words

Management of Design and Innovation - Essay Example The scope of design management extends to the internal and external interfaces of the firms. Design management usually is a long and continuous activity which influence the performance of the firms at all levels. Design management processes are practiced by people having different levels of authorities and trainings. Such people function with multiple orientations covering various kinds of organisations of different sizes and nature. Koppelmann and Spies (1993) opine that design management is having multifarious facets and there are different opinions about design management. This paper details the design management process and the application of design management in the case of Zara clothing Spain as a case study. Technology is said to be at the heart of any manufacturing company. The technology helps in designing the products or the processes required to manufacture the products. It is critically important for the companies, that the existing technologies are assimilated into the business, and also anticipate the impact of the emerging technologies on the designs, products, and processes. This is considered critical as the companies are always under constant pressure to bring new products to the market as quickly as possible. Thus the purpose of any organization is to provide the customers products or services with the best possible quality and at affordable price which is greatly facilitated by the design management. An organization is sure to gain a competitive advantage through designs that bring new ideas to the market quickly, do a better job of satisfying the customer needs, or are easier to manufacture, use, and repair than existing products and services. Design can be understood as a critical process for a firm. Strategically design defines a firm's customers as well as its competitors. It capitalizes on the core competencies of a

BUSINESS ETHICS Dissertation Example | Topics and Well Written Essays - 6500 words

BUSINESS ETHICS - Dissertation Example This may be further represented in class biases and alienation. This definition would seem to not prohibit the use of humour to make jest of any ideological, political, or moral concern, but also positions these judgments outside of the specialization of business management. This definition represents the pragmatic way businesses have operated throughout the history of capitalism on the basis of humour and morale in social operations. This represents a slight change in my perception of what is ‘good’ Business and Management Research (BMR), but is not really a main aspect of ethical concern. Tutorial 2: Introduction to Interpreting and Evaluating Research (27 October 2010 and 3 November) In the essay â€Å"Product development: Past research, present findings, and future directions† by S.L. & Eisenhardt, K.M. ... It is unfair, unrealistic, and possibly morally wrong to expect people to be less than fully human when acting as employees as a company, by requiring them to â€Å"turn off† their moral, political, and ideological concerns in the organization of commercial activity. This represents a major change in my perception of what is ‘good’ Business and Management Research (BMR), because to do so leads to injustice, poor practices, and social harm in the greater population through valuing only the bottom line of business against the environment and collective heritage of humanity. Tutorial 3: The Context of Management Research (8 December 2010 and 15 December 2010) In the articles from â€Å"Looking at ourselves as we look at others: An exploration of the publication system for organization research† by Nord (1985), I learned to apply the principles of Business and Management Research (BMR) to the recent financial crisis where banks in America were donating to polit icians that wrote the legislation for their industry, and the relaxed standards of the Bush administration that allowed banks to take on excessive risk. The absence of both political regulation and business ethics in Wall St. financial banks largely contributed to the crisis. This represents a significant change in my perception of what is ‘good’ Business and Management Research (BMR), because of the importance of public relations, brand identity, and advertising in modern business. Tutorial 4: Evaluating Quantitative Research (24 November 2010 and 1 December 2010) I used the information received from Miller& Shamsie (1996) in their essay â€Å"The resource-based view

Turning Fear Into and Everyday Relevance Term Paper

Turning Fear Into and Everyday Relevance - Term Paper Example Even more revealing were the results found by the 2000 Decorte, Verschaffel and Green study which stated, â€Å"when middle school students were prompted to ask their parents about their use of the Pythagorean Theorem, an overwhelming 78% answered that they could not recall ever using the Pythagorean Theorem in their day to day lives† (Decorte, Verschaffel and Green). In response, many modern day teachers have begun to explore new ways to teach the Pythagorean Theorem in an attempt to help students see the relevance it can have in their everyday lives. For many students, the words â€Å"Pythagorean Theorem† can sound incredibly daunting and intimidating. It is the teacher's job to show them how the process of this theorem are performed in various daily situations, and that they have probably already experienced it without realizing it. By introducing students to real-life examples, teachers can help take the fear out of the equation. â€Å"Some mathematicians and teachers have attempted to produce textbooks that use a bare minimum of sentential representation and argument† (Lindsay). These books often proved useless without further explanation from the teacher. They proved that students needed real-life examples of how the Pythagorean Theorem worked in order to understand the process. The diagrams in these textbooks are often referred to as â€Å"diagrammatic demonstrations†. â€Å"A diagram that illustrates a mathematical relation by showing in essence that it is an accurate reflection of the behavior of obje cts in space and provides an understanding because it grounds the abstraction in our customary experience† (Lindsay). The problem with these diagrams was that they often reflected shaped that were unrealistic and never seen in real life. One approach that many teachers are currently pursuing is to use pictures of real buildings, baseball fields, and other such relevant structures.

Education in Barbados Essay Example for Free

Education in Barbados Essay Barbados had one of the oldest and most advanced education systems in the Eastern Caribbean in the late 1980s. Education dated back to 1686, when private funds were used to build the first school. Throughout the eighteenth and nineteenth centuries, education was controlled by the Anglicans, who were later joined by other religious groups. By 1962 education was free for all nationals and administered primarily by the state. This trend continued, so that by 1984 only 4 percent of the primary and secondary schools were managed by churches. Barbados longstanding emphasis on education was evident in the values and goals of contemporary society. Education has traditionally been associated with success and upward mobility. In 1970 Barbados officially claimed to have achieved a 99-percent literacy rate, a figure that was questioned by some observers. Despite these doubts, observers generally agreed that in the 1980s literacy in Barbados exceeded the rates of other Caribbean societies. In 1984 Barbados had 126 primary schools, 110 of which were administered by the state. Approximately 1,350 teachers were available to instruct the 35,000 students. There were sixty-four secondary schools, five of which prepared students for technical careers. A total of 6,000 students attended secondary-school programs. Postsecondary education consisted of seven institutions that awarded degrees or certificates. Four schools offered specific vocational training: the Barbados Institute of Management and Productivity, the Erdiston Teachers Training College, the Tercentenary School of Nursing, and the Samuel Jackman Prescod Polytecnic. Academic programs at the university level were conducted at the Cave Hill Campus of the University of the West Indies (UWI) and the Barbados Community College, which offered vocational and technical classes as well. The UWI also included Codrington College, a local theological seminary. In 1979 the government created the Skills Training Programme to augment existing education programs. It was designed to fulfill the need for short but intensive training in vocational subjects and to prepare students for careers in mechanics, electronics, horticulture, masonry, plumbing, and other technical and vocational occupations. Although the educational infrastructure was designed to meet both the nations academic and vocational needs, observers seriously questioned Barbados ability to provide quality instruction in fields related to tourism,  agriculture, and manufacturing, the major economic undertakings in the 1980s. Few courses were actually offered in agricultural science and commerce; as a result, an inadequate number of Barbadians were being prepared to take on the responsibilities inherent in a growing economy. The education system was also criticized for being stratified along socioeconomic lines. In general, upper-class Barbadians prepared for university studies at the best primary and secondary schools, received a disproportionate number of scholarships, and had the best records for entering the professional disciplines. On balance, however, most Barbadians felt that the education system still afforded opportunities to achieve at least limited upward mobility. The government appeared to be attempting to address specific criticisms of its educational policy; its goals for Barbadian education in the 1980s included the promotion of equal educational opportunity and enhanced technical and vocational programs in all schools. In spite of its shortcomings, the Barbadian education system remained the best in the Eastern Caribbean in the 1980s.

Assignment On Aircraft Power Systems

Assignment On Aircraft Power Systems In this assignment, I intend to provide a brief presentation about the principle of operation of the aircraft electrical power systems, specifically, Integrated Drive Generators (IDG) in a modern aircraft. I will compare and contrast the fluid and electrical methods of power generation and give a brief on the safety precautions to be followed when handling aircraft electrical power supplies and during a functional test. There are various kinds of power generation on an aircraft, namely electrical (generators batteries), fluid (hydraulics pneumatics). Depending upon the application, the power sources may vary. AIRCRAFT ELECTRICAL SYSTEM The main function of any aircraft electrical system is to generate, regulate and distribute the electrical power in the aircraft. Modern aircrafts use more electrical power as they are equipped with more Electronic Flight Instrument System (EFIS). This is done so as to reduce pollution in the environment, for a clean and safe flight. Electrical power is used to operate: Aircraft Flight Instrument- Electronic Centralized Aircraft Monitoring (ECAM) Essential Systems- Primary Flight Display (PFD), Navigation Display (ND) Passenger Services- In-Flight Entertainment (IFE) Most of the aircraft systems use a power standard of 115 [emailprotected] 400Hz; 28VDC. There are various electrical power sources on the aircraft: Engine Driven AC Generators (EDG) Auxiliary Power Units (APU) Ram Air Turbine (RAT) Battery Supply External/Ground Supply (Spoor, 2012) Components in an electrical system include: AC Generator/Alternator produces AC power. Constant Speed Drive Unit (CSDU) regulates the rotating speed (input) to deliver a constant output from the engine to the generator. Integrated Drive Generator (IDG), Generator and CSDU connected either coaxially or side-by-side. Mostly coaxial connection. Transformer Rectifier Unit (TRU) converts the AC power to DC power Generator Control Unit (GCU) monitors and controls the generator output. Each engine powers up one or more generators. Airbus A380 has four engines and four generators. Whereas, Boeing 777 has two engines and two generators. The power produced by these generators is used to power up the entire aircraft. (Boeing, 2012) All the other power sources, except external supply, are used in case of emergencies only. External power supply is used on ground when the engines and the APU are not running. It is supplied via Ground Power Unit (GPU). GPU can be portable or stationary and they provide AC power through the external plug on the nose of the aircraft. They can be used to power up an entire aircraft or a specific area in the aircraft. (Spoor, 2012) Figure : Aircraft Electrical System (Classic Jet Sims, 2012) AIRCRAFT HYDRAULIC SYSTEM The principle of a hydraulic system is to convert fluid power into mechanical power and then use it for various applications on the aircraft, such as extension/retraction of landing gears, flaps, and speed and wheel brakes. The power source here is the hydraulic fluid. The pressure for generating the hydraulic power is supplied by the Engine Driven Pump (EDP) and the Electric Motor Driven Pump (EMDP). They are both mounted on the engines. Commonly used hydraulic fluids on the aircraft are: MIL-H-5606 (Mineral Based Fluid) MIL-H-83282 (Synthetic Hydrocarbon Based Fluid) MIL-H-87257 (Same as MIL-H-83282, but it has been improved in its low temperature viscosity) MIL-H-8446 (Phosphate-Ester Based Fluid) (Wikipedia, 2012) Special care must be taken when handling the hydraulic fluid. Some of the hydraulic fluids are skin/eye irritant. Also it is extremely important for the fluid to be free from any contamination for flight safety. Advantages of the hydraulic system as a power source includes: Lightweight Easy installation Simplified Inspection Minimum Maintenance Approximately 100% system efficiency, with only negligible loss due to friction. (EAC, 2012) Figure : Basic Hydraulic System (Free Online Private Pilot Ground School, 2006) COMPARISON OF AIRCRAFT ELECTRICAL AND HYDRAULIC SYSTEM FEATURE ELECTRONIC HYDRAULIC Construction Power is generated by the engine, by rotation of turbine shaft. Power is generated by incompressible hydraulic fluid. Pressure for hydraulic actuation is supplied by EMDP and EDP. Similar to that of an electric circuit. Components include: Generators/Alternators, Batteries, Switches, Bus bars, Fuses, Circuit Breakers, Voltage Regulators, Ammeters, and Wires. (Free Online Private Pilot Ground School, 2006) Components include: Reservoir, Pump, Hydraulic Fluid, Accumulators, Actuators, Filters, Hydraulic Fuses, Tubing, Pipes, Valves, and Seals. Uses Lights, Radio Equipment, Indicators, Warning Systems, Heaters, Starting motor. (FlightLearnings, 2012) Extension/retraction of landing gears, flaps, and speed and wheel brakes. Principle of Operation Generate, Regulate and Distribute electrical power generated. Work is done by moving an incompressible fluid, Pascals Law. (EAC, 2012) EMERGENCY DEPLOYMENTS IN EVENT OF GENERATOR(S) FAILURE In case of main engine driven generator (EDP) failure, there are various methods to ensure continued power supply for safe landing: Auxiliary Power Unit (APU) Ram Air Turbine (RAT) Battery When the main engine generators fail, APU or RAT is deployed. When the secondary methods fail, batteries are used as the last resort for a safe landing and evacuation. AUXILIARY POWER UNIT (APU) Auxiliary Power Units (APUs) is a small gas turbine engine which provides electrical, hydraulic and pneumatic power (depending on the design) for ground or in-flight operations. It is also used as a backup source in emergency situations. It is commonly found on large aircrafts. It is usually located in the tail end of the aircraft. When started, it normally runs on 100% speed. It produces 115VAC @ 400Hz. Some can also generate 28VDC. The main purpose of the APU is to start the engines in the aircraft. This is because the engine requires high rotational speed for its self-sustaining operation. In this case, APU is started by battery or hydraulic accumulator and then used to generate the necessary rotational speed. It is also used to run the equipment when the engines are shutdown. This is used for air conditioning for the passengers prior to engine start. However, it can also be connected to a hydraulic pump to power up hydraulic equipment (flaps and flight controls). (Wikipedia 2012) RAM AIR TURBINE (RAT) Ram Air Turbine is a small airflow driven turbine that is connected to either a hydraulic pump or an emergency alternator or a main generator. In normal flight, it is stowed away in closed compartment in wing or fuselage. It is deployed only when there is total power loss due to engine failures. It provides enough power to run the critical systems, such as, flight controls. The power generated by the RAT depends on the airspeed. More the speed, more the power generated will be. Some aircrafts use RAT in normal operation. For example, in crop dusting RAT is used to power up the chemical sprayer. (Wikipedia, 2012) BATTERY Aircraft batteries are used to start the engines or the APU. But they are also used in emergency situations as a last resort for safe landing. There have been cases where it has been used to restart the engines even after engine flame-out. They also act as a buffer for the DC connections. It regulates the voltage to ensure the power quality for the equipment connected to it. Two types of batteries are used in aircrafts today, Lead-acid and Nickel Cadmium (Ni-Cd). Lead-acid batteries are either valve regulated or vented. They are used in light and general aircrafts. Ni-Cd batteries are used in larger aircrafts. Lead-acid batteries are generally heavier and have less capacity than the Ni-Cd ones. (Dr. Thomas, 2010) Figure : Lead-Acid Battery (Chief Aircraft, 2012) Figure 4: Nickel-Cadmium Battery (Surplustraders.net, 2012) AIRCRAFT ELECTRICAL SYSTEM USING FREQUENCY WILD AC GENERATOR From 1950s to early 1960s some turboprop aircrafts used frequency wild, now Variable Frequency (VF) system. Airbus A380 and Boeing 787 Dreamliner are some of the modern civil aviation aircrafts that have adopted the VF system again. Figure : Simplified Frequency Wild System (Scribd, 2012) CONSTRUCTION As shown in Fig.4, the Variable Frequency Generator (VFG) is directly connected to the engine gear box. (Langlois, 2004) states: VFG is a conventional wound rotor synchronous alternator. There is no CSD or IDG in this system. This is done so as to improve the reliability of the system and also to reduce the weight of the aircraft. Airbus A380 uses aluminium cables instead of copper for weight reduction. The system is also fully computerized. Contactors and Breakers have been replaced by solid-state devices for increased reliability and performance (Global Aircraft, 2012). OPERATION Frequency Wild AC power can only be supplied to the resistive circuits such as the electrical heater, engine de-icing heaters, windshield heating, etc. as shown in Fig. 4. The AC power generated is sent to the TRU where the voltage is stepped down from 360Hz-760Hz (Langlois, 2004) to 28V and then rectified to DC voltage. Then it is used by the DC components. CONTROL PROTECTION A traditional Constant Frequency unit has only a constant frequency of 400Hz voltage supply. A constant speed drive unit drives the generator. It is also expensive and not easy to maintain. A VFG is flexible as it can handle a range of frequencies rather than a constant one. In this unit, there is no CSD or IDG. It is more advantageous over Constant Frequency Unit because: It has low maintenance Long lifespan Cheaper Process temperature is controlled within VFG itself. Equipment protection from excess torque damage The variable frequency generator (VFG) is used on applications with a high percentage of resistive AC or DC loads and provides power to many of the next generation aircraft. Hamilton Sundstrands variable frequency starter generator (VFSG) and motor controller system provides main engine start and control. The voltage is controlled around the generator. This is done by controlling field strength of the AC generator by feedback signal from the voltage regulator, which keeps the voltage constant irrespective of the speed and load variations. VFGs are preferred over DC systems because they were much less affected by poor brush performance at higher altitudes and they had better power to weight ratio. AC/DC ELECTRIC MOTORS AND ACTUATORS PERFORMANCE DC actuators are typically high-speed reversible series-wound motors. Their output is converted to driving torque using step-down gearbox. These motor actuators are self-contained units, as they combine both electrical and mechanical devices. They can exert linear thrust over a short distance. AC MOTOR DC MOTOR

Database Management Essay -- Technology, Computer Softwares, Data

What is a database management system? Discuss each of the five important software components of a database management system. Data Base Managements System (DBMS) is a computer software program installed on a system hard drive that catalog, retrieve, and run queries on data. It provides ways for data to be altered or removed by users or other programs. There are several different types of database management systems that exist that were created for the proper control of databases for specific purposes. The five software components of a database managements system are DBMS engine, data definition subsystem, data manipulation subsystem, applications generation subsystem, and data administration subsystem (Cummings, 2010). Database management systems engine is the central component of the DBMS it stores and retrieves data it accepts logical request from multiple other subsystems and transform them into its physical equivalent. The DBMS engine collects logical requests for data users and issues physical input/output requests to the computer operating system. The data requested is gathered from physical storage and while the data remains in memory, it is managed by the DBMS engine. Data definition subsystems create and maintain data dictionary. Define structure of the files within the Data Base. Its logical structure must be defined prior to entering information and any time information is entered or deleted the data definition subsystem must be used. Field name, type, form, default value, validation rule, is an entry required, and can there be duplicates are examples of logical properties (Cummings, 2010). Data Manipulation Subsystem is used to add, change and delete information in a database. There is software in the ... ... performance products. Some examples is nanotube which is have been added to the frames of tennis racquets and gulf clubs. Nanotubes are some of the toughest materials known to exist to man. Since these tubes are microscopic, millions can be added to the tennis racquet to make it strong in order to give tennis players more control and power. Medicine is another area in which nanotechnology transforming. With the medical field dealing with things on the smallest level, the small nano devices are being developed to enter the body. An example is Nano robot which is a computer-controlled robotic device used to treat and eradicate diseases. Nanotechnology differ from traditional manufacturing in which traditional manufacture take a large item and break it down to its smallest form, nanotechnology starts at the smallest form and build up (Cummings, 2010).

naturalism :: essays research papers

Naturalism in THE HURRICANE   Ã‚  Ã‚  Ã‚  Ã‚  Naturalism is the theory that one's surroundings and background determines their fate. THE HURRICNE has many naturalistic elements. Rubin Carter's background and surroundings are what determined his fate.   Ã‚  Ã‚  Ã‚  Ã‚  Trouble started very young for Rubin Carter. When he was just a boy he was sent to a juvenile home. Rubid didn nothing wrong, but because he was black it made it easier for him to get accused. As Carter got older, he grew stonger and wiser. He became a boxer. Soon, hte name stayed with him, Rubin the Hurricane Carter. He was an excellent boxer and had many things going for him. In a bar one night two men were shot and killed. But because Carter was black it was very easy for him to be accused. Rubin lost his case and went to prison.   Ã‚  Ã‚  Ã‚  Ã‚  The Hurricane has many naturalistic elements. The fate of Rubin Carter was determined by his background and surroundings. Because Carter was black, it made it easier for him to be accused of crimes wheterher he committed them or not. Therefore, based upon Carter's surroundings and background, his fate of being accused of a crime he did not committ and going to prison for it showes that THE HURRICANE has naturalistic elements. Naturalism is the theory that one's fate is determined by their surroundings. Antying that happnes to someone is due to everything around them. Such things as thier family, where they live, where they work, and so on. THE JUNGLE is an excellent example of a naturalistic piece of literature. Many of the characters fateswere determined by their surroundings.   Ã‚  Ã‚  Ã‚  Ã‚  THE JUNGLE is a very good example of a naturalistic piece of literature. The characters in the novel all have a fate which is determined by their surroundgins. One example is Jurgis. His fate of becoming an addict to alcohol was caused by everything surrounding him. Things that happened to his family and at his work caused him to start drinking. Many things went wrong at work. It was a very bad environment for him to work in. His injury kept him away from work which motivated him to drink. The death of his wife, Ona, and his child, Little Antanas also motivated Jurgis to start drinking.   Ã‚  Ã‚  Ã‚  Ã‚  Another example is Little Antanas. His fate, which was death, was caused due to the poor living conditions that surrounded him. Everything that surrounded him was filthey.

L.A. Confidential :: essays research papers

L.A. Confidential   Ã‚  Ã‚  Ã‚  Ã‚  L.A. Confidential is a movie of cops that are more corrupt than the criminals they arrest. Throughout the movie Bud White is portrayed to have a personal hatred for women abusers despite becoming enraged and hitting Lynn Bracken. At the beginning of the movie, Bud and two other officers are seen sitting in a car, observing a man beating his wife. Officer White gets out of the car, approaches the house, and then pulls the family’s Christmas decorations from the roof. When the man comes outside to see what is making all the noise is about, Bud White immediately begins to beat him. Afterwards, Bud handcuffs the man to a rail.   Ã‚  Ã‚  Ã‚  Ã‚  In another scene from the movie Bud White is seen leaving a bar. When Bud exits the bar, he notices a woman, with bandages on her nose, sitting in a car with two men. Bud approaches the car to investigate. In the process, the driver jumps out of the car and tells him to get lost. Then Bud White beats him up. Bud is thinking that someone has abused the woman, when in actuality the woman had been hit in the face with a tennis racket. Throughout the movie Bud is seen beating the information out of suspects. Such as when he is seen at a bar squeezing a man’s testicles until the man told him the information that he wanted to hear. During an interrogation at the precinct, Bud White hears a suspect confessing to have raped a girl. The officer in the room is having trouble getting the criminal to tell him where the girl is, so Bud storms into the room, and pins the guy against the wall and puts a gun in his mouth until the guy tells him where the girl can be found. He became enraged and lost control when he found out Exley and Lynn had slept together. He went to Lynn’s house and overcome by anger hit her. After hitting her he realized that he had done something he never wanted to do which was hit a woman. Bud White’s hate toward women beaters seems to have come from seeing his mother beat to death by his father.   Ã‚  Ã‚  Ã‚  Ã‚  Although White is portrayed as being brainless in the beginning of the movie, by the end of the movie he had proven himself to be intelligent. He is seen as being a tough cop with no brains.

A Synopsis of the Movie, Ip Man 2: Legend of the Grandmaster

Period 4 – Films Literature 8/19/20 The movie that I find the best would be Ip Man 2 Legend of the Grandmaster directed by Wilson Yip. Ip Man 2 Legend of the Grandmaster is an action packed martial arts film, this movie being a semi-biographical cinema is based on a real person in history which makes the move even more interesting and exciting. Ip Man 2 Legend of the Grandmaster not only has an action packed side but also has a heartfelt side by putting in Yip Man's tough life after world war two.This movie also has spectacular fghting scenes choreographed by Sammo Hung a renowned in the martial arts department. Y Ip Man 2 Legend of the Grandmaster demonstrates what every martial arts movie needs, action! Yip Man is a martial arts teacher which basically says that his skills surpass all. A fight scene that stood out for me was a fight that was set in a fish market. Yip went to the fish market to save a pupil of his and the rescue turned into an all-out brawl, a huge one!The br awl was on a scaled of about two to sixty and Yip showing his skills defended himself throughout the entire fght unscathed! The fight scenes show the passion and dedication that Yip had for Wing Chun. Although this being a martial arts movie you wouldn't expect much of a storyline rather than Just a brawl fest to brawl fest, but that is what separates this movie form the rest. In the first movie Yip Man was a rich man but that change after the Japanese invaded China in world war two.Now in the sequel Yip Man tries to start a martial arts class but things do not turn out right, people didn't pay when he asked and he was unaware of a rule put down by the city. So Yip Man is yet to face another tribulation and he conquers it. Also his wife is a bigger part in this movie making her role bigger by showing the relationship her and Yip have and what a big impact she has on him. This movie also shows the tribulations that the Chinese race had to deal with. TheBritish were put as the antagon ist; they abused the Chinese and used them as dogs. This harass they receive requires the Chinese to band together and get their honor back in a brawl. This fght is very honorable and inspiring because it shows that you can overcome anything together. Ip Man 2 Legend of the Grandmaster is a movie that I will always love and a movie that I will watch over and over again and I will not tire of it. It has beautiful fghting scenes and story line is very touching. This movie is my favorite movie.

European Invasion

The European invasion of the New World from the 15th century to the 18th century altered the lives of the Native Americans that lived in eastern North America in more ways than they could’ve ever imagined. The New World provided raw materials, such as metal as soil. The massive invasion all begun in 1492 which was then known as the massive â€Å"white† invasion and Columbus’s discovery marked the beginning of this invasion which overtook all of North America over the next four centuries. The lives of the Native Americans would never be the same.European settlers introduced the Native American’s to new costumes but not all, if any, were good. Europeans brought Christianity into the New World and introduced the Native Americans to the religion. Europeans thought that Native Americans would be easy to convert into Christianity. â€Å"These people would be easy to convert to our holy faith† is famous quote by Jacques Cartier. Europeans didn’t con sider the Native Americans opinions or beliefs and frankly they didn’t care. Europeans also introduced the Native Americans with diseases that they weren’t use to, for example malaria and infections to smallpox and measles.Due to all of these diseases the population of North America decreased and continued to until about the 1700s. The Europeans were also armed with technology and the Native American cultures of their civilizations were lost. Europeans took over the New World between the 15th and 18th century, although that wasn’t their main objective. Their main objective was to settle and gain land in North America. With the arrival of the Europeans governments and laws were formed that didn’t benefit the Native Americans in anyway.Europeans claimed lands and Native Americans were forced to accept that the Europeans were now in charge. Europeans had all the authority in the New World. Native Americans were experiencing New World imperialism. Native Amer icans became frightened and started living in fear. Decrease in population and war resulted in the creation of new communities for instance the Choctaw. To trade a faster pace and consume more money was what the Europeans dreamed of and they didn’t want anything or anyone to get in the way of their dream. Native Americans were dragged into the expanding economy.Before the Europeans had invaded the New World, North America had a strong military force that began in the Mohawk Valley. They were known as the Iroquois and were merged by the Mohawks, the Oneidas, the Cayugas, and the Senecas, which was five Indian nations. The Native Americans were such powerful individuals but then the Europeans came along and stripped them of all their pride and altered the way they once looked at life. All and all, right before the Native Americans eyes change was happening and the way they lived was never how it once was before.The Native Americans had their land ripped from right underneath th em without any warning or any sign. Though the Native Americans of eastern North America may have had questions to why their lives were being altered. The Europeans invaded the New World during the 15th-18th century without any answers to why they were doing so. The Europeans had expectations and a plan. They didn’t stop at any means and they were determined to follow through with the success of their invasion.

Ancient Greeks Essay

Ancient Greeks made many influential contributions to western civilization such as in the areas of philosophy, art and architecture, and math and science. The Greeks were a remarkable civilization and contributed things people use in every day life then, and currently. Some very important people of Ancient Greece include Socrates, Aristotle, Pericles’, Hippocrates, Euclid, Sophocles, Plato and Galen. All of these people shaped western civilizations, while Greece was in two wars at the time. They pushed through hardships and still created innovations that contributed to the western civilization. In the area of Philosophy, Socrates, Aristotle and Plato had a belief system that was very powerful. The philosophers initiated an approached that was based on reason. Their theories were diverse and they tried to â€Å"identify underlying principles†. Socrates believed in the encouragement of question, saying that a life without examination is not worth living. Aristotle thought that people should to live for a reason, and strive for that reason. Plato was a philosopher, and student of Socrates. He laid the foundations for philosophy in western civilizations. These ideas of human reasoning had been a big part of Greece’s influence. As well as philosophy, art and architecture were a contribution to the western civilization. As far as the monuments made, columns were used and are well known today. Performances of music and dance were vital parts of religious festivals. Not very many forms of art have been saved or found from the time of Ancient Greece. But, dramas and plays took a central role in the culture. Sophocles had created plays, and the most common was tragedy. Greek literature contained a strong epic as well including the tales of Iliad and Odyssey, both written by Homer. All of the poems, literature, architecture and dramas were vital for the western civilizations. Math and science were the most important and well-known achievement in the Greeks history. They had achieved all kinds of things in the area of psychology, physics, astrology, math, and medicine. Euclid was a Greek mathematician and was known as the ‘father of geometry†. He impacted all of math due to his book of Elements. This book had provided many theorems, which had simple forms of geometry. Although the theorems may have not been very complex, they are extremely important. Not only did they influence western civilizations, but the whole world. Medicine was very important in this era. Hippocrates was an ancient Greek physician referred to as â€Å"the father of western medicine†. He adapted the Hippocratic oath stating that he would never supply someone with harmful medicine. As well as medicine, the field of astrology was key. They Greeks had studied the stars and the way things had worked in the atmosphere at night. All which were very important for the western civilization. In conclusion, Greeks were very studious and contributed things in the fields of philosophy, math, science and art. They created geometry, astrology, philosophical advancements and art advancement. All of which are used today.

The Nativist’s Response to Immigration

Immigrants have been seeking salvation or just new opportunities in America for hundreds of years. Even Americans originally started off as immigrants. They came to settle in this New World to seek opportunities. These types of immigrants were white, strong, leaders and felt they were superior. In the mid nineteenth century, the â€Å"new† immigrants were also welcomed. According to President Grant, these â€Å"new† immigrants were the weak, broken, and crippled people who had nowhere else to go. Grant thought these â€Å"new† immigrants would ruin the tone of the American life into a more vulgarized tone now that these immigrants are filling up the jails and asylums (Document 4). They mostly came from Southern and Eastern parts of Europe and were poor, ignorant, and illiterate. They were needed for working power and employers liked to use them because they were able to give them cheaper wages. Soon there was an economic boom when machines came to replace the workers. Resentment soon arose since job offers were scarce and immigrants received the jobs over the Americans. Certain groups of Americans opposed open immigration. Many of these people did not want new arrived immigrants to have the right to vote until they have lived in the United States for 21 years. These were often referred to as the Nativist groups. These Nativists were the old type of American immigrants who looked down on these new immigrants and wanted to shield America from them. Nativism did speak out against the Chinese immigration on the West Coast. Nativist arguments say that Chinese immigration would create race antagonism throughout the entire public. This means there will be hostility among the races so there would be separation among the country. In 1882, the Chinese Exclusion Act suspended Chinese immigration for ten years and prohibited the naturalization of the Chinese. The Chinese were once a great asset to America. They came over from China and helped build the railroads. After the railroads were finished, the Chinese were supposed to leave. Instead, they stayed in America for good. The Chinese immigrants now wished to assimilate their own culture and ideas with the American ideas. Americans, mostly Nativists, were extremely bothered by this because the Americans did not want the Chinese to bring their alien culture to America (Document 1). Other groups, who resented other races from assimilating, organized classes so the immigrants can learn the American language and way. They said immigrants should become citizens by learning the â€Å"American language. † They thought if the people that come to America and don’t learn the way of the Americans, then this country will soon be just like the old country, the country which they have already left (Document 3). Resentment over immigration still arose within the United States. Many writers began to blame immigrants for problems regularly occurring throughout time. E. A. Ross wrote that immigrants had a strong influence on American politics and government. He said that the simple minded foreigner is the tap-root to the main issue. The tap-root is the source of the problem. Ross said that once that simple minded foreigner unleashes his ideas, the foreigners get a stronger grip on the situation. They soon broaden and entrench their power by intimidation at the polls; they have ballot frauds, saloon influence, and much more. This will all start from one foreigner and will soon increase till the foreigners have a larger vote (Document 7). Other writers like Rev. Josiah Strong blamed certain â€Å"diseases† on immigrants. These were not actual diseases but more like problems in the country. He blamed immigrants on the lack of holiness in the Sabbath and how it is now a holiday. He also blames the liquor traffic on the immigrants too (Document 2). Whether the immigrants came to America or not, these problems would still be here. It’s human instinct to attack a different race or religion when a problem comes about. That is exactly what the Americans were doing to the immigrants. There was always a large amount of immigrants arriving into the United States. The greatest danger of unrestricted immigration is that the immigrants can overrun the master race and they can have more control then the Americans (Document 5). When a lower race mixes with a higher race in sufficient numbers, history proves that the lower race will prevail. If the Americans continue to let unrestricted amounts of immigrants enter the United States, their thoughts and believes would soon alienate the Americans and the Americans would soon become the strangers in their own country (Document 6). Once Americans began accepting that there is no way to completely stop the flow of immigrants into America, they began to find ways to limit the amount arriving. In 1921 the National Origins Act was put into effect. It looked at the immigration record to find a base year. They looked at the year that the fewest immigrants arrived and called that the base year. They used the base year as the quota for immigrant arrival. Illegal immigration continued and the immigration and Naturalization office spent a good deal of time tracking down and deporting illegal immigrants. Finally the immigration Act of 1985 was passed which said that an illegal immigrant who has been in America for at least five years, and who can prove it, can apply for citizenship and become an American citizen. As long as the flow of immigrants is carefully regulated then immigration should be no problem, maybe even beneficiary.

Greek Default of Sovereign debt Essay Example | Topics and Well Written Essays - 3500 words

Greek Default of Sovereign debt - Essay Example For some, such as the NAFTA (North American Free Trade Area), regional integration is based on establishing free trade zones. For others, such as the AU (African Union) and the EU (European Union), regional integration is based on political and economic cooperation (Sore, 2010). With the trend of regional and global integration, one of the emerging concepts is sovereign debt borrowing. Under this concept, a country can borrow a loan from another country or institutions. For example, a country that is experiencing financial problems such as growing budget deficits has the option of sovereign debt to address the problem. Some of these institutions include the World Bank, EU, and IMF (International Monetary Fund). Foreign debts are supposed to be paid as per the agreement. However, there have been cases of defaults in repayment. Usually, a country that is unable to repay its foreign debts on the agreed date can renegotiate the deal for an extension. The renegotiation option is not always a guarantee. A foreign debt default can cause adverse implications for the affected countries. In the past, such defaults have resulted in military invasions such as when the US occupied Haiti in 1915 (Huang, 2014). There have various foreign debt defaults since 2000. Some of these include: Apart from these cases, one of the largest and most recent foreign debt default occurred in 2012. Greece defaulted on its $138 billion foreign debt, which became the all-time biggest foreign debt default (Huang, 2014). The purpose of this paper is to present an in-depth analysis of the Greece sovereign default. The paper will present a detailed discussion of how the default came to be, what factors and actors contributed to it, the reactions of different stakeholders, the lessons drawn, and the way forward. The paper will present a background of the Greek debt crisis,

Creating a Climate of Ethical Behavior at Workplace Research Paper

Creating a Climate of Ethical Behavior at Workplace - Research Paper Example Knowledge sharing practices enable organizational members to share ideas and fully exploit knowledge-based sources. Personal commitment and trust is necessary because they help in knowledge management process. This paper will explore ethics in an organization as well as workplace safety-enhancing behaviors and qualities such as personal commitment and trust. Undoubtedly, ethical behavior significantly contributes to the success of many organizations. An ethical work climate is part of the organization and it is a representation of organizational practices that are viewed as right or wrong. Many individuals believe that an ethical work climate is indispensable for a good business. Notably, organizations striving for excellence and success in their business activities tend to focus on a strong ethical culture. Organizations need to effectively respond to both economic and non-economic surroundings in order to achieve their goals, but this requires members to be socially responsible and behave ethically. Truly, creating a working environment guided by ethics can be a very important move for an organization. In contrast, unethical behaviors negatively influence the organization. For instance, unethical behaviors are more likely to increase the organizations’ liability and financial risk. Secondly, consumers would not be attracted to the products and services of the organization with an unethical climate. More so, an unethical climate negatively affects the workers since it lowers job satisfaction and performance. In most cases, unethical behavior emerges from lack of knowledge and an inability to come up with ethical solutions (Patterson, 1989). Unethical behavior makes individuals become more sensitive to the likelihood of censure and this will in turn motivate them to avoid censure behaviors (Sinha, 1967). Therefore, it is very appropriate to institutionalize an ethical attitude in the organization. This paper provides a thoughtful

South Asian Sufism Research Paper Example | Topics and Well Written Essays - 750 words

South Asian Sufism - Research Paper Example This diversity has to a certain extent been created by the subcontinent?s numerous linguistic and cultural customs and its unique networks beyond the region. In terms of Islamic roots, Sufism has, in a way, played a key role in the spread of Islamic devotional and spiritual life in South Asia. At some stage in the eighth and ninth centuries A.D., a novel prominence began to grow within Islam. This prominence was a constructive response against the established uncongenial and ceremonial nature of Islam. The quest for deeper meaning started with a pietistic simplicity, which in turn led to the advance of the well-acknowledged mystical side of Islam - known as Tasawwuf or Sufism. Sufism is in essence a spiritual form of Islam focusing on the connection between the individual and divinity. The Sufis surfaced in South Asia around 800 years ago, and were initially stanch devotees, whose meager woolen attire signified their humility, hence the word â€Å"Sufi† that denotes Arabic wor d for wool. The Sufis sought the mysticism, divine realism or eventual truth that stands over all the fantasies and deceptions about the materialistic society. In order to attain ecstatic unification with God, Sufis integrated practices of sound and actions -- chanting and harmony, swaying and dance. Sufi followers joined in closed brotherhoods or tariqahs, each following a captivating leader (shaykh). They offered an Islam that fused South Asian customs and worship styles, including Christian saints and Hindu gods. Sufism highlights the importance of â€Å"Real†, as distinctive from a faint acceptance of what is considered to be real in everyday existence, by authentic comprehension of the self and the 'veils' which separate it from any understanding of the truth. (ELWELL-SUTTON). This also implies a quest for real existence. It also emphasized empathy from one soul to another, in spite of all other differences. The Sufi trend drew attraction throughout South Asia (as well a s Eurasia and Eastern Europe) can be recapitulated in Rafiq Zakaria?s book as: â€Å"Though unconcerned with affairs of state, the sufis had a profound influence on the Muslim polity. They humanized its rigours and reduced the area of conflict between religion and politics. They gave Islam a broader base. Non-Muslims flocked to sufi hospices in large numbers and in due course hundreds of thousands came into the fold of Islam. . . .† (Zakaria) Sufism: Spirituality or Libertarianism? Despite the fact that Sufism has been majorly identified as the spiritual and mystic extension of Islam, parts of literary research argues about the existence of Sufism as a political entity. For example, the way Sufis' tombs surfaced and grew as places of pilgrimage indicate that the ‘missionary’ agenda of the Islamic mystics was devised primarily for conversion and the establishment of Perso-Arabian cultural control in South Asia (R.Upadhyay). Despite of the cultural relevance of Suf ism, over the period of time, differences have also arisen from divergence of interests among Muslims over what should be the right standard for cultural and political life. As Sufism endorsed various forms of cultural articulation, it did not extend unilaterally as a response to orthodoxy and legalistic rigorism but from time to time it harmonized and engaged in these developments. In the same way, hostility between shari‘a (law) and tariqa (Sufi path) in Islam is an open topic of debate, although Sufi researchers emphasize that

British Airways Essay Example | Topics and Well Written Essays - 750 words

British Airways - Essay Example This is according to the chairman of British Airways from 1993 to 2004, lord Marshall of Knightsbridge. While the history of BA in its current structure and name began in 1976, its predecessors can be traced back to the late ‘10s. The first British Airlines, Aircraft Transport and Travel, was established in 1919, with the initial scheduled flight taking off on August the 25th from le Bourget to Honslow, its home. Two other airlines, Handley page and Instone, were established using modified bombers. The three companies underwent a period of great difficulty, especially competition from French airlines, which were cheaper. To solve these problems, they merged to be joined later by British Marine Air Navigation, forming Imperial Airways. Imperial Airways began local and overseas flights immediately, flying as far as Egypt and India with a crew of 250 and a fleet of 18 crafts (Gaskell, 2010). This paper is an essay on British Airways. Later, Imperial Airways was a Brisbane, Austral ia route, whose duration would take grueling 12 days. The new airline added new planes such as the short S.23 C-class model, which signified that the airline was growing, as was a new carrier British Airways limited (Gaskell, 2010). After the start of the 1st World War, these two merged to form British Overseas Airways Corporation, which re-started its transatlantic flights after the war ended. In addition, they created the BEA, a new airline to handle the European flights. At this point, the carriers needed to order new and more efficient aircraft. BOAC consequently ordered the Boeing Strato-cruiser, the Lockheed Constellation, and a Rolls-Royce engine equipped version of the DC-4. It did not take long before they ordered a jet plane, the De Havilland Comet, which dramatically reduced the length of trans-Atlantic flights (Marriott, 2010). The early 60’s saw BOAC order the Rolls-Royce Conway engine driven 707-436 to tide over until the VC-10s were ready. By 1970, with the fir st 747 and rapid growth, BOAC and BAL were ready to merge and work as one, establishing British Airways in 1976. BA’s most crucial year was 1976; it had a partnership with Concorde, coupled with big fleets of Lockheed TriStar and Boeing 747. The early 1980s saw the company face its second major threat, economic trouble, although measures were taken to privatize the company, which duly happened in 1987. Increasing competition from US based carriers also forced BAs hand in the merger with British Caledonian, which saw the A320 among other planes enter the fleet (Marriott, 2010). This merger further enabled BA to begin operations at Gatwick Airport. However, its base remained at Heathrow, where BA operates approximately forty percent of the total flights. In addition, the airline has created service stations in Birmingham, Glasgow and Manchester. British Airways has built its brand around fast travel, which has seen it at the forefront of jet travel. The first jets for short hau l flights were ordered in 1980, with forty four 737-200 planes delivered. New 737s were ordered in the late 80s, most of them being the 400-plane model with increased passenger capacity. Although not a choice of BA, the Airbus A320, entered the British Airways service after it merged with British Caledonian (Marriott, 2010). However, the planes proved quite efficient in their flights and duties. Medium haul flights were performed by the larger Boeing 757 fleet, as well as the 767, which were equipped with engines from Rolls-Royce. A number of Boeing 767-300ER in turn, performs long haul flights, which do not require huge passenger capacity. Most of these carry two hundred and fifty two passengers, with additional Boeing 777-200 and 747-400 complementing this segment. Recently, the company replaced all Boeing

How does globalization affect the environment Essay

How does globalization affect the environment - Essay Example One area of human life that has experienced heavy issues due to globalization is the environment in which human beings live. Policy makers, environmentalist and other stakeholders have attacked globalization for impacting human environment in a negative manner. Body Disadvantages One of the main impacts of globalization is that globalization has led to increase in the spending ability of all individuals and have led to elevation in the consumption levels of human beings and this has impacted the ecological system in a negative manner. Increase in income level have made people demand for more goods and services and this has led to decrease in the natural resources that are offered by the environment. With the increase in demand for goods and services, there has been an increase in the transfer of natural resources from one region to another. Before globalization started spreading, people used to be dependent on their local manufacturers and service providers for goods and services. No w due to decrease in boundaries, people have started demanding for goods and services that are developed in foreign regions. To transfer goods and services, heavy amount of fuel is consumed which has led to degradation of the environment due to increase in pollution. The fuel used in transportation of goods has led to increase in the amount of fossil fuels burned to produce fuel. ... s waste is being dumped in oceans and this dumping process has ruined the underwater life and has led to increase in chemicals being deposited to oceans. For example: during the period of 2010, oil spill from the containers of British Petroleum ended up damaging the ocean in a very negative manner and this happens to be one of the several harmful effects of globalization on the environment (Cook, 2010, p.214). Increase in industrialization along with globalization has led to an increase in the amount of chemicals that are dumped into soil and due to this several plants as well as weeds have been produced. The waste that is toxic in nature and is dumped in soil has severally damaged plant life and had interfered with the natural way of growth of plants. Throughout the world heavy cut down of forests are taking place as wood obtained from forests is used in production of several goods such as furniture and paper. Due to this, carbon dioxide in the environment has increased and release of oxygen by plants has decreased. Similarly, cut down of mountainous regions have even been conducted to create new roads and for real estate purposes and this has long term negative impacts on human health. Plastic is being heavily used throughout that world for several purposes such as packaging and this plastic is not renewable in nature. Plastic is used in then discarded in form of waste which is negatively impacting the environment. Plastic bags tend to enter water lines as well as beaches and as plastic waste is burned, it result in emission of fumes that are toxic in nature and these fumes tend to impact the environment in a negative manner. According to Savedge, more than 100,000 marine animals experience death or are murdered by animals as they dump plastic bags in oceans and

Professional Portfolio Assignment Example | Topics and Well Written Essays - 1500 words

Professional Portfolio - Assignment Example Correspondingly, I would provide a structured portfolio of mine, where I will include a brief description of my educational platform, learning theory along with curriculum map and the use of tools that I have initiated throughout the course of my learning as an educator. Professional Portfolio Educational Platform and Learning Theory Education is one of the most vital aspects of growth for any individual. Understanding the value of learning as the cornerstone of a successful life, individuals from various age groups and demographics have started taking participation in the educational sector. In this regard, the role of an educator has become quite prominent over the years owing to their significance in forming the educational career of an individual. As an educator, I feel esteemed to be rewarded with the opportunity to assist learners in developing their skills and abilities with regard to their competent areas. Correspondingly, in my professional experience, I was able to learn th at an ideal educator is of extreme need to develop the skills and capabilities that might be in need to provide a proper learning experience to the students. In consideration to all these facets, I desire myself to be in a professional career associated with education. ... Additionally, with reference to my desire of becoming an educator will always intend towards maintaining an atmosphere, which will encourage maximum concentration amid the learners and facilitate effective learning in-turn. It would also be vital to mention that I am quite appreciative towards adopting proper learning theories that would allow me to have proper control over the learning capabilities of the students. As per my experience, adoption of effective learning theory is quite important to facilitate learners’ effective performance. Out of the various principles of learning, I prefer Readiness, which depicts that a learner can be able to learn more when he/she is physically, mentally, as well as emotionally deciphers the yearning to learn. Correspondingly, adoption of such theory requires me to create interest among the students by presenting the value of a particular topic or a subject matter. In my professional career, I also emphasize posing continuous mental as well as physical challenges, with the intention to keep the learners’ interests intact for a longer period of time. Curriculum Map and Assessment Strategy Based on my personal and professional experiences, I was able to understand that setting efficient curriculum is among the major needs in the field of education. Educational institutions all over the world have well identified the needs to develop an effective curriculum where learners would be able to perform better. Correspondingly, the role of an educator is also vital in such cases. I, as an educator, understand this particular facet in my role and ensure best possible contribution towards the same. I was mainly engaged with the Master of Education

Substance use and mental health Essay Example | Topics and Well Written Essays - 1000 words

Substance use and mental health - Essay Example The list of substances that are abused is broad and the method and route of administration also vary. The problem with abusing substances however is not present only in young population but is more diffusely distributed in all ages and social groups. Most common substance abuse found in the same statistical analysis in the general population ranging between age of 16 and 74, that was reported by the participants themselves was cannabis (in 24 %), amphetamines were tried or used by 7 % of the cohort group, 5% ever in their life used magic mushrooms, about 4 % of the cohort population ever in their life used or are still using ecstasy, cocaine, LSD, tranquilizers were used by 3% of the population, other volatile substances and gases were used in 1% of the population and other substances like crack, heroin, steroids were also present in about 1%. There are also other substances that were used but are not listed in this text. Also we must have in mind that this study was based on the sel f-report of the participants so there is a possibility for even larger prevalence of these substances if we consider the population that didn’t report abuse of substances. ... iew Schedule CIS-R, where score above 12 is considered a sign of high probability for neurotic disorder in one person and in participants with score above 18 is considered that psychiatric treatment is necessary (Lewis et al, 1992). They also tested for disorders in the personality of the participants using the SCID-II (Semi-structured interview for making DSM-IV Axis II: Personality Disorder diagnoses). It is a set of questions that are completed by the participants in order to assess the personality disorder based on the Diagnostic and Statistical Manual of Mental  Disorders,  Fourth Edition (DSM-IV). They also used Schedules for Clinical Assessment in Neuropsychiatry manual to asses for psychosis or more severe psychiatric disorder in the participants. Based on these examinations it was found that abuse of substances was more common in participants who tested positive in some of the screening tests that were used. It was found that 12 % of the people who scored 12 or above on the CIS-R scale (some type of neurosis) had abused substances in the last month before the survey compared to 5% of the other population. Among the specific neuroses it was found that participants with suspicion for obsessive-compulsive disorder had the higher incidence of substance abuse in the previous month (15%). Most significantly it was found that 32% of the participants that were suspected for presence of anti-social personality disorder was found that were abusing some substance in the previous month before the survey. In the group of participants that were diagnosed with psychosis or other major psychiatric disorder no significance in incidence of abusing substances was found. Based on this study we can conclude that neurosis, antisocial personality disorder, obsessive-compulsive

Baker and McKenzie Law Firm in Worldwide Markets Research Paper - 1

Baker and McKenzie Law Firm in Worldwide Markets - Research Paper Example Baker and McKenzie is an American law firm based in Chicago city. The firm has a total of 3774 attorneys, 1349 partners, and 2425 associates (Baker and McKenzie 1). Baker and McKenzie law firm tops the list of the most successful law firms in the United States. The firm is renowned to have redefined the worldwide law firm of the 20th century in order to meet the global economic challenges of the 21st century. The 3774 lawyers are located in over 70 offices worldwide. The firm has a unique way of working, thinking and behaving. The function across borders and they deal with a wide variety of issues as well as practices (Baker and McKenzie 1). Baker and McKenzie law firm understands the economic challenges facing the globe, and for that reason, it has been of the forefront of matters since the firm’s opening in 1949. Laws that work in Baker and McKenzie law firm include financial litigation, product liability, aviation law, capital markets, bankruptcy, business and industry, com mercial law, insolvency, intellectual property, international law, international trade, and investment law. The firm also deals with consumer law, contracts, copyright, corporate governance, and corporate law among others (Baker and McKenzie 1). The firm has advised leading companies on matters of today’s incorporated world market. Baker and McKenzie law firm has cultivated the tradition, commercial simplicity, and technical, as well as interpersonal skills, vital to offer world-class service tailored to the needs of world-class customers globally.

Management, Organisations and People Module Report Essay Example for Free

Management, Organisations and People Module Report Essay Introduction: The aim of this report is to provide an explanation to ‘Mimi Vasquez Hair and Beauty’ managers’ approach to leadership and go on to explore his relationship to his work group and how they have developed over time. It will first outline the methodology used to conduct this report and then go on to introduce the managers and workers and explain how their current work roles have developed over time. Subsequently, the report will provide an explanation to ‘Mimi Vasquez Hair and Beauty’ managers’ approach to leadership and go on to explore his relationship to his work group. To conclude the report, there will be a quick summary of what has already been mentioned and some limitations of the findings, methodology and related theories used in the report. The beauty salon which was named after its manager is privately owned and located in Chiswick in West London. In addition, it has two other branches located in Ealing and Hammersmith, both also within the West London area and owned by the same manager. All three of the beauty salons are relatively small in size making satisfactory profits and located just off the high streets in quieter areas. The first branch was opened in 1999 in Chiswick and the others followed on 5 years later, the Hammersmith branch being the newest. Method This report was conducted using both primary and secondary research. The primary research was collected directly from the manager and team members by interviewing them. By so doing, the research collected was new and wasn’t research that had already existed. Secondary research was collected through the use of books, the internet and articles and hence looking at existing data. Findings and discussion Behavioural theory As the manager, Mimi Vasquez, supervises and manages the overall performance of his staff and the business. His current work role is to analyse and recommend developing strategies on how to improve the quality of their services e.g. more speed and efficiency in cutting hair and accuracy with mixing colours of hair dye. These two examples are some of Mimi’s main targets and he wishes to have met these goals by July 2011. Mimi also examines ways to achieve his business goals of maximising profits and acknowledges that compensations and rewards have worked well in the past as they motivate and encourage staff to work better: Every year he elects 2 people as the most improved and most enthusiastic team members and rewards them in the form of bonuses and HMV vouchers. His work role also involves instructing his team members and allocating them to different parts of the salon when the day gets busy Moreover, this has played a great role in the development of Mimi’s leadership within the business. Yukl (2006, p5) defines leadership as- Leadership is the process wherein an individual member of a group or organization influences the interpretation of events, the choice of objectives and strategies, the organization of work activities, the motivation of people to achieve the objectives, the maintenance of cooperative relationships, the development of skills and confidence by member, and the enlistment of support and cooperation from people outside the group or organisation. Yukl’s definition very closely matches Mimi’s approach to leadership in the sense that it emphasizes the importance of ‘people skills’ and the social influence that leadership can have. One theory to provide evidence for this is the behaviour perspective. This theory claims that people become leaders because of what they do and this can be split into two different categories: task behaviour and relationship behaviour. Task behaviour places the main focus on the degree to which a leader emphasises productivity targets, goal accomplishments and maintaining standards. These behaviours can also be called ‘production-centred’ and it can be seen in Mimi’s leadership style when he uses HMV vouchers to motivate his staff to work harder and faster. Mimi has also said that rewards gave his staff an incentive to work and this played a crucial part in keeping them happy and full of energy, even towards the end of the day. Furthermore, relationship behaviour focuses on manager’s actions that show concern for their staff and their welfare as opposed to behaviours that concentrate on completing tasks. Although this contrasts to task behaviour, this can also be seen in Mimi’s leadership approach in the sense that he aims to improve his staff’s skills and help them gain more confidence in their job role. Trait perspective The controversy in defining leadership has enabled many different theories to be developed in an attempt to explain the meaning of a leader within a business or an organisation. Bratton (2010, p363) cited that ‘individuals who occupy leadership positions possess superior qualities or attributes compared with the traits possessed by non- leaders’. This view is known as the trait perspective and its’ theories such as the ‘great man theories’ focus mostly on positive characteristics such as stamina, intelligence and fluency in speech. Research in 1974 by Stogdill showed that socioeconomic factors also played a great role for example, very few corporate leaders had fathers who held a low class position or who were paid quite poorly. Stogdill also found that intelligence and fluency in speech were very closely related to leadership and used these traits to differentiate leaders from followers. He then concluded that there were ‘specific patterns’ of traits that occurred in some people which gave them an advantage when seeking a leadership position. Shabina and Mario also described their manager to hold very positive characteristics such as friendly, talkative, enthusiastic and organised and wasn’t like the other staff members at ‘Mimi Vasquez hair and beauty’ in the sense that he was much more determined. This therefore justifies why Mimi is a leader. In addition, research into ‘substitute’s for leadership’ claim that there should be a distinct difference between the leader and the followers in a business and there should be inflexible rules and formalized areas of responsibility in order to prevent the followers from being guided by their peers and replacing their existing leader. This would occur if the followers realized that their peers had the skills equivalent to their leader and they decided to follow them instead. Keith Grint (2005) also argues that successful leadership- Is not a list of innate skills and competences, or how much charisma you have, or whether you have a vision or a strategy for achieving that vision, but whether you have a capacity to learn from your followers. This again, provides evidence against the trait perspective stating that this is not what makes an effective leader. The shared/super leadership theory The founding of Mimi’s other branches, helped him gain experience which developed his role even further as he had to identify problems, make choices and provide alternatives actions to his initial plans. His role development throughout the years has been quite significant and his responsibilities have duplicated allowing him to improve his time management and organisation. Mario and Shabina are two team members of the salon who were also interviewed. Mario is a professional hair stylist whose work role involves restyling and cutting clients’ hair, dying, permanent hair straightening, Brazilian hair blow drying etc. His work role is crucial to the business as he has qualities and skills that require a lot of training and experience in order to gain. Mario’s work role has developed over the years as his experience has allowed him to move up the ladder in regards to the styles and haircuts he can confidently perform. The number of clients he reserves on a daily basis has also increased over the past 6 years of working at the salon showing an improvement in his abilities. He is now responsible for his own clients as before he would only deal with Mimi’s clients and help around. However, he is still in a lower position to Mimi and is usually responsible for making sure that Mimi’s clients are booked in for the dates and times they requested, making sure none of the time slots clash with one another. The Shared/super leadership theory suggests that excellent leaders are those who help their followers develop by acting as their teacher rather than keeping all of their knowledge to themselves. To add, Peter Senge(1990) also stated that ‘leaders are designers, stewards and teachers’ which supports the view. Mimi has constantly trained his team members, in particularly Mario and this also adds towards the statement that Mimi is an effective leadership. Fiedler’s leadership contingency theory Shabina is the only beautician at ‘Mimi Vasquez Hair and Beauty’ and her role involves taking care of her own customers and making her own bookings as well as offering all of the services; waxing, laser hair removal, threading, massages etc. Her role doesn’t involve anything to do with hair, and she works in her own room downstairs. However, Mimi is her manager also and so it is her responsibility to follow all of his guidelines and instructions. Her role has developed over the past 3 years as she first started out as an assistant, cleaning around and helping the beautician. She then worked her way up by gaining experience and qualifications and developed her role into a full-time professional beautician. Fiedler’s leadership contingency theory proposes that the effectiveness of the leader depends on whether the leadership style is matched with the followers and the environment. It is based on 3 main assumptions: 1) leader-member relations, which relate to whether the leader receives support, respect and trust of the followers; 2) task structure, which relates to how structured the tasks performed by followers are; 3) position power, which relates to the formal authority that the leader can exert through the use of punishment and rewards. This theory can explain Mimi’s leadership style as it explains why Mimi’s leadership is effective and hence how he has been able to successfully run the business for so many years. In relation to this theory, Mimi is placed to be known as a relationship-orientated leader and so it explains that his team members have been able to develop throughout the years because of his concern for them. The situational leadership theory Mimi’s relationship to his group is fairly hierarchical where he would force influence upon others to do something that they otherwise wouldn’t. This hair and beauty business is a good example as it shows how Mario takes responsibility for making bookings for both, his and Mimi’s clients. The group itself had developed over the years as they have slowly started to work as a team, helping each other and finishing each other’s jobs off when the salon gets busy. In 1999, manager Mimi’s Vasquez’s main roles were to simply open and close the salon, receive payments for the service provided and order raw materials such as; hair dye, scissors, wax etc. Now, with the growth of the business, all of the team members in the salon have developed their roles as they have had to cover for each other and enhance coordination skills. The situational leadership model is where the leaders’ leadership style depends on the maturity of the followers; it can explain that why Mimi trusts his staff to look after his salon whilst he is in a different branch. The friendly nature of the business also allows Mimi to be less formal and more flexible with rules and procedures. Bratton (2010, p.370) states that ‘Follower maturity is determined by the ability and willingness of the followers to accept responsibility for completing their work’. The fact that each team member has their own set of responsibilities proves that their levels of maturity are very high and hence can explain why Mimi’s rules are quite flexible, according to Mario and Shabina. Conclusion The report has explored Mimi’s approach to leadership using the behavioural, trait, shared/super leadership, contingency and situational theories and it can clearly be seen that leadership is not easily defined and its effectiveness isn’t easily measured. It has also outlined the work roles of the manager as well as the team members and explained how their roles have developed. To conclude, although the report gives a sense of idea of what Mimi’s leadership approach may be, in reality it is very hard to accurately describe using only one theory. Appendix Bratton, J. (2010) Work and organisational behaviour. 2nd edn, Hampshire: Palgrave Macmillan Grint,K.(2005) Leadership: limits and possibilities, Basingstoke: Palgrave Senge, P.M.(1990) The Fifth Discipline. New York: Currency/Doubleday Yukl, G.(2006) Leadership in organizations.6th edn, Englewood Cliffs, NJ: Prentice Hall

Effects of Physiological Reproductive Events on Ovary

Effects of Physiological Reproductive Events on Ovary Chapter one Introduction Background The two majors function of the ovary is the differentiation and release of female gametes (oocyte), which can then be successfully fertilised and ensure the survival of species. The ovary is also an endocrine organ that produces steroid hormones that allow the development of female secondary sexual characteristics and supports pregnancy. The mammalian ovary is covered by a single layer of epithelial cells (surface epithelium), which vary in type from simple squamous to cuboidal to low pseudostratified columnar (Anderson et al. 1976). Directly underneath the surface epithelium there is a layer of dense connective tissue known as the tunica albuginea. The mammalian ovary is a heterogeneous organ containing follicles and corpora lutea at various stages of development. The ovarian follicle is the fundamental unit of the ovary, each follicle consists of an oocyte, surrounded by granulosa cells and outer layer of theca cells ( 1.2 Folliculogenesis During embryogenesis, primordial germ cells (PGCS) migrate from the yolk sac through the dorsal mesentery of the hindgut, to the genital ridge. The germ cells then undergo extensive proliferation, and lose their motile characteristics, in addition, somatic cells derived from the mesenchyme of the genital ridge, proliferate as well (Hirshfield 1991). The germ cells cease mitotic division and form association with small numbers of pre-granulosa cells to form primordial follicle (Telfer et al. 1988). The germ cells undergo the first meiotic division and are now called primary oocytes. The oocytes then become arrested in the diplotene stage of prophase I of meiosis until the primordial follicles start to grow and finally reach the ovulatory stage. In the diplotene stage, the oocyte may prepare itself for rapid mitosis and implantation, by producing large amounts of mRNA and ribosomes (Picton et al. 1998). Primordial follicles may be observed from week 22 in the human (Faddy and Gosden 19 95) and week 13 in the cow (van den Hurk and Zhao 2005). The pool of primordial follicles develops during fetal life in some species (e.g primates, ruminants), but in others it develops during the early neonatal period (e.g rodents, rabbits) (Marion et al. 1971). The number of primordial follicles present at birth represents the total population of germ cells available to mammalian females during their entire reproductive life (Kezele et al. 2002), and is believed to serve as the source of developing follicles and oocytes (Eppig 2001). Although recent studies have suggested that postnatal oogenesis may also occur in female mammals (Johnson et al. 2004), they suggested that germline stem cells can repopulate the postnatal ovary and renew the primordial follicle pool. This group subsequently went on to suggest that these cells were derived from bone marrow (Johnson et al. 2005). This has attracted a great deal of attention as well as criticism (Gosden 2004; Byskov et al. 2005; Telfer et al. 2005). This is an ongoing debate but the balance of evidence suggests that renewal is not a major factor in ovarian development (Eggan et al. 2006). In mammals, the number of primordial follicles in the ovaries at birth varies enormously between species, ranging from tens of thousands in mice to millions in humans and domestic species (Gosden and Telfer 1987). These follicles must develop through primordial, primary and secondary stages before reaching the preovulatory stage, and subsequent ovulation (Figure 1.1). Proper follicle development involves maturation of the oocyte, which is surrounded by variable layers of granulosa cells, enveloped by theca cells (Drummond 2005). Granulosa cells provide physical support of the oocyte and mediate signals between the oocyte, outer theca cells and endocrine hormones. Once the pool of primordial follicles has been established, follicles gradually and continually leave the resting pool to begin growth. However, less than 1% of primordi al follicles present at the time of birth of an animal will ever proceed to ovulation (Erickson 1966), with the majority of follicles degenerating by atresia. 1.3 Regulation of early folliculogenesis A critical process in ovarian biology is the transition of the developmentally arrested primordial follicle to the developing primary follicle. Follicular growth may begin at any time during the females life. The primordial follicle contains an oocyte arrested in meiosis I surrounded by flattened somatic cells termed the pregranulosa (Kezele et al. 2002). During onset of primordial follicle growth, flattened pregranulosa cells become cuboidal and begin to proliferate. The enclosed oocyte begins to grow at the same time (Anderson et al. 2000; Clark and Eddy 1975). The growths of both the primordial follicles with oocytes characterize the initiation of the growing phase. The oocytes within the primordial follicles remain quiescent for months to years until they receive the appropriate signals to initiate folliculogenesis and primordial to primary follicle transition. So far, little is known about the molecular mechanisms and extracellular signalling factors that regulate this process. These processes directly affect the number of oocytes available to a female throughout her reproductive life. Once the pool of primordial follicles is depleted, ovarian steroidogenesis ends and the series of physiological changes called menopause begins (Richardson et al. 1987). It is unclear whether the signals originate from the oocyte, or/and from surrounding somatic cells, or from outside the ovary. It is also unknown if it is an inhibitory factor preventing resting primordial follicles from leaving the stock or a stimulus acting on the resting primordial follicles store that stimulates some follicle to leave it (Gougeon and Busso 2000). A multitude of factors may act locally to regulate early folliculogenesis by promoting growth (Bennett et al. 1996) or by inhibiting growth (Bukovsky et al. 1995). The initial growth signal appears to be independent of the pitui tary gonadotropins (Peters et al. 1975) (Figure 1.3). Primordial follicles do not possess receptors for FSH hormone (Oktay et al. 1997). Despite some studies suggesting that gonadotropins are involved in the initiation of follicular growth in immature rodents (Lintern-Moore 1977; Neal and Baker 1973), nevertheless, during natural hypopituitary conditions in both animal species and humans, the initiation process is not completely abolished (Howe et al. 1978; Halpin et al. 1986). Although follicles at early stages of development have been shown to express follicle stimulating hormone receptors (FSH-R) (Bao et al. 1998), in the absence of gonadotropins during the early stages of follicle growth, follicles can still develop to the early antral stage (Awotwi et al. 1984; Gong et al. 1996). Knockout mice who are null mutants for either FSH receptor or LH receptor are able to undergo the primordial to primary follicle transition (Zhang et al. 2001; Abel et al. 2000). Several local factors have been found that can regulate the primordial to primary follicle transition. Bone morphogenetic protein-7 (BMP-7) has been shown to promote the primordial to primary follicle transition and to increase granulosa cell proliferation (Lee et al. 2001). Leukemia inhibitory factor (LIF) has also been shown to promote the primordial to primary follicle transition and to up-regulate granulosa cell expression of kit ligand (KL) (Nilsson et al. 2002). Bone morphogenic protein-15 (BMP-15) is a growth factor expressed in the oocytes of developing follicles that plays a role in early follicle progression (Dube et al. 1998) and stimulates granulosa cell proliferation (Otsuka et al. 2000). Growth differentiation factor-9 (GDF-9) has been localized inthe oocytes of mouse (Dong et al. 1996) rat (Jaatinen et al. 1999) and human (Aaltonen et al. 1999) primary follicles. Nilsson and Skinner (2002) have shown that GDF-9 promotesthe development of primary follicles in neonatal r at ovaries,but it has no effect on the growth of primordial follicles (Nilsson and Skinner 2002).Studies by Wang and Roy (2004) have provided the first evidence that GDF-9 can promote the formation of primordialfollicles and their subsequent growth in neonatal hamster ovaries (Wang and Roy 2004) . Anti-Mullerian hormone (AMH) is a member of the transforming growth factor- ÃŽ ² (TGF-ÃŽ ²) is considered as a negative regulator of the early stages of follicular development. AMH is produced by the granulosa cells of developing preantral and small antral follicles which inhibits the primordial to primary follicle transition (Durlinger et al. 1999). AMH is never found in primordial follicles, theca cells or oocytes (Ueno et al. 1989; Hirobe et al. 1994; Baarends et al. 1995). Examination of ovarian follicles in AMH-deficient female mice revealed lower numbers of primordial follicles and more growing follicles compared with wild-type mice, these findings revealed that, in the absence of AMH, ovaries are depleted of their primordial follicles earlier than they are in control mice and these observations led to the propsal that AMH inhibits primordial follicle recruitment (Durlinger et al. 1999). Results were obtained from another in vitro experiments on the bovine ovarian cortex sugges ted that, at least in nonhuman species, the presence of AMH acts as a brake on the activation of primordial follicles and the growth of preantral follicles (Gigli et al. 2005). It has been demonstrated that oocytes from early preantral, late preantral and preovulatory follicles up-regulate AMH mRNA levels in granulosa cells, in a fashion that is dependent upon the developmental stage of the oocyte (Salmon et al. 2004). These findings suggest that oocyte regulation of AMH expression may play a role in intra- and interfollicular coordination of follicle development. ; kit ligand (KL) and basic fibroblast growth factor (bFGF) secreted by pre-granulosa cells and oocyte respectively, have mutual stimulatory effects on oocytes and granulosa cells; they also promote recruitment of theca cells from the surrounding stromal/interstitial cell population. Stromal/interstitial cells and theca cells secrete BMP-4 and BMP-7, which promote follicle activation and survival. GDF-9 and/or BMP-15 secreted by the oocyte of the activated follicle promote granulosa cell proliferation, KL expression and theca formation. Granulosa cells of growing follicles secrete AMH that appears to act as a ‘brake on primordial follicle recruitment (Knight and Glister 2006). Foxo3a (FKHRL1), a member of the FOXO subfamily of forkhead transcription factors, has been implicated in the regulation of follicle activation. It has been indicated that Foxo3a functions at the earliest stages of follicular growth as a suppressor of follicular activation (Castrillon et al. 2003). It was suggested that Foxo3a serves an essential role by suppressing the growth of primordial follicles, thereby preserving them until later in life (John et al. 2007). It was shown that Foxo3a -/-ovaries contained markedly elevated numbers of early growing follicles, and this extensive of follicular growth in Foxo3a -/- females resulted in the progression of increased numbers of follicles to more advanced stages of follicular development and this misregulation of this process can lead to premature ovarian failure (Castrillon et al. 2003). Kit ligand (KL) is produced by the granulosa cells of developing ovaries (Manova et al. 1993; Ismail et al. 1996) and KL receptors (c-kit) are present on oocytes and theca cells (Manova et al. 1990). C-kit is expressed at the surface of mammalian oocytes at all stages of follicular development in postnatal ovaries of the mouse, the rat and humans (Driancourt et al. 2000; Horie et al. 1991; Manova et al. 1990; Orr-Urtreger et al. 1990) and its only known ligand, Kit-ligand (KL), which is also referred to as stem cell factor (SCF). KL acts to recruit theca cells from surrounding ovarian stroma during folliculogenesis (Parrott and Skinner 2000). Therfore, KL is thought to act as a signal from the granulosa cells around primordial follicles to the oocyte and surrounding stroma to promote the events of the primordial to primary follicle transition (Parrott and Skinner 1999). In this study (Parrott and Skinner 1999), treatment of in vitro cultured follicles from postnatal ovaries from 4 da y old rats, with KL dramatically induced the development of primordial follicles, but was completely blocked by the Kit antibody ACK2. 1.4 Follicle development Follicular development is regulated by both endocrine and intraovarin mechanisms which co-ordinate the processes of somatic cell proliferation and differentiation (Moley and Schreiber 1995). The basic functional unit in the ovary is the ovarian follicle that is composed of somatic cells and developing oocyte. The two primary somatic cell types are the theca cells and granulosa cells. These two somatic cell types are the site of action and synthesis of a number of hormone that promote a complex regulation of follicular development. The prolifetation of these two cell types is in part responsible for the development of the antral ovarian follicle. At the same time, the oocyte is undergoing developmental changes necessary to allow the resumption of meiosis after the preovulatory surge of gonadotrophins (Montgomery et al. 2001). This regulation occurs according to endocrine principles, involving hormones such as pituitary gonadotropins , ovarian steroids and locally produced factors that act either on the cell that produces them (autocrine) or on neighbouring cells (paracrine) (Salha et al. 1998). Ovarian follicular development is a long process which can take around 6 months from the initiation of growth of primordial follicles until development of a preovulatory follicle in humans, cattle and sheep (Lussier et al. 1987; Cahill and Mauleon 1980) and around 4 months in pigs (Morbeck et al. 1992). The majority of this time is spent in the pre-antral stages of development. Already at this stage, a considerable proportion of growing follicles fail to survive and they degenerate through a process termed follicular atresia. Observations in humans and in animals suggest that apoptosis is the mechanism of follicular atresia (Tilly 1996; Kaipia and Hsueh 1997). In women, the dominant follicle orginates from primordial follicle that was recruited to grow almost 1 year earlier Folliculogenesis can be divided into two stages: the gonadotropin-independent (preantral) and gonadotropin-dependent (antral or Graafian) periods (Erickson and Shimasaki 2000). Locally produced growth factors are critically involved in controlling preantral follicle development during the gonadotropin-independent period. After antraum formation, the follicle becomes dependent on FSH stimulation for continued growth and development. Interestingly, it was discovered that the process of folliculogenesis is controled by growth factors secreted by the oocyte (Matzuk 2000). Five growth factors have been identified in mamalian oocytes: growth differentiation factor-9 (GDF-9) (McGrath et al. 1995), bone morphogenetic protein -15 (BMP-15) (Dube et al. 1998; Laitinen et al. 1998), bone morphogenetic protein -6 (BMP-6) (Knight and Glister 2006), transforming growth factor -ÃŽ ²2 ( TGF-ÃŽ ²2) (Schmid et al. 1994), and fibroblast growth factor-8 (FGF-8) (Valve et al. 1997). Experiments with knockout mice have demonstrated that in the absence of GDF-9, folliculogenesis is blocked at the primary to preantral stage (Dong et al. 1996). Consequently, there are no Graafian follicles, no ovulations, and no pregnancies. 1.4.1 Follicular cell types and follicle classification The two primary somatic cell types in the ovarian follicle are the theca cells and granulosa cells. These two somatic cell types are the site of action and synthesis of a number of hormones that are involved in the complete regulation of follicular development. 1.4.1.1 Granulosa cells Granulosa cells are the primary somatic cell type in the ovary that provides a physical support of the oocyte and mediated signals between the oocyte, outer theca cells and endocrine hormone. Regulation of granulosa cell differentiation during folliculogenesis requires the actions of a number of hormones and growth factors. Specific receptors have been demonstrated on granulosa cells for gonadotropins follicle stimulating hormone (FSH) and luteinizing hormone (LH) (Richards and Midgley, Jr. 1976). In addition, receptors have been found for factors such as insulin-like growth factor (IGF) (Adashi 1998) epidermal growth factor (EGF) (Vlodavsky et al. 1978) and anti-Mullerian hormone (AMH) (Josso et al. 2001). Actions of these hormones and growth factors on granulosa cells vary with the stage of differentiation. Follicular growth and steroidogenesis are dependent on the coordinated actions of FSH and LH with their receptors on granulosa cells and thecal cells of ovarian follicles. Both granulosal and thecal cells are involved in production of estradiol-17ÃŽ ² (two cell/two gonadotropin model which is well accepted for many species). 1.4.1.2 Theca cells Another important cell type in the ovary is the ovarian theca cell. These are differentiated stromal cells that surround the follicle and have also been termed theca interstitial cells (Erickson and Case 1983). The thecal cells can be distinguished as two distinct layers, the inner layer of cells, the theca interna has a basement membrane separating it from the outmost layer of granulosa cells. The theca interna is a highly vascular layer. One of the major functions of theca cells in species such as the cow, human and rodent is the secretion of androgens (Fortune and Armstrong 1977). At the primordial stage, no theca cells are present; however during the transition to the primary stage, theca cells at this stage of development are gonadotropin and steroid independent and non-steroidogenic (Braw-Tal and Roth 2005). Theca externa which is less vascularized layer and merges into the stromal tissue without clear boundaries. The ‘two-gonadotrophin, two-cell model of follicular estradiol biosynthesis According to the two-cell-two-gonadotrophin theory, the ovary has two cellular compartments that are driven independently by LH and FSH to produce ovarian steroids. Androgen production by theca cells is a function of LH, whereas aromatization of these androgens to oestradiol by granulosa cells is controlled by FSH (Gougeon 1996) (Figure 1.5). Androgen synthesis occurs in the theca interna regulated by LH, by expressing P450c17, the rate-limiting steroidogenic enzyme in androgen synthesis (Sasano et al. 1989). Theca interna are capable of synthesizing all the steroids from cholesterol to testosterone and are the major source of follicular androstenedione. In contrast, granulosa cells are the major source of follicular estradiol. Granulosa cells are intrafollicular sites of androgen metabolism (Ghersevich et al. 1994) and express aromatase P450arom (Whitelaw et al. 1992) this enzyme converts androgens to estrogens. FSH also induces granulosa cell LH receptors that are functionally coup led to aromatase. Thus, uniquely in the preovulatory follicle, both the synthesis of androgen (in theca cells) and its aromatization to estradiol (in granulosa cells) are directly regulated by LH (Fortune and Armstrong 1977). . In the theca, under the influence of LH, cholesterol is converted to pregnenolone and metabolised through a series of substrates ending in androgen production. The two-cell, two-gonadotrophin model comes into play with androgens produced by the theca cells transported to the granulosa cells where they are aromatised to oestrogens (Drummond 2006). 1.4.2 Classification of follicle stages In sheep, the stages of follicular development have been classified on the basis of the number of granulosa cells in the largest cross-section of follicles (McNatty et al. 1999), 1.4.3 Follicular development in primates 1.4.3.1 Oocyte growth and maturation Once follicles have been initiated to grow, the granulosa cells proliferate to form the different stages of follicular development (Telfer et al. 2000). During follicular activation and early development in mice, for example, the oocyte growth occurs rapidly with an approximatly 300-fold increase in volume during the 2-3 week growth phase (Wassarman and Albertini 1994), which is also accompanied by a 300-fold increase in RNA content (Sternlicht and Schultz 1981) and a 38-fold increase in absolute rate of protein synthesis (Schultz et al. 1979). These events are indicative of a period of cell growth with high metabolic activity (Wassarman and Albertini 1994). Oocytes complete most of their growth phase before the formation of a follicular antrum (Wassarman and Albertini 1994), and the increase in oocyte diameter and volume during antral follicular growth is relatively small (Eppig 2001; Wassarman and Albertini 1994). If the oocyte is to be capable of fertilization and subsequent embry onic development, it must acquire the ability to resume meiosis. Oocytes from immature follicles are unable to resume meiosis (Iwamatsu and Yanagimachi 1975) however, by the time the follicles have reached the antral stages the oocytes of most species have acquired the ability to resume meiosis (Mattioli and Barboni 2000; Telfer 1998). 1.4.3.2 Follicular growth Early in oocyte growth, a homogenous glycoprotein layer called the zona pellucida (ZP) is secreted shortly after initiation of follicular growth (Epifano and Dean 1994). It forms a translucent acellular layer separating the oocyte from the surrounding granulosa cells. However, contact between granulosa cells and the oocyte is maintained via cytoplasmic processes, which penetrate the zona and form gap junction at the oocyte surface. Progressively, follicles become secondary follicles. In addition to oocyte growth and granulosa cell proliferation, the preantral follicle also increases in size through formation and growth of ovarian stromal cells on the outer membrane of the follicle forming the theca layers of the follicle. The thecal cells can be distinguished as two distinct layers: highly vascular theca interna, surrounded by a fibrous capsule, the theca externa. The granulosa cells continue to proliferate, resulting in a further increase in follicular size. The formation of the follicular antrum marks the beginning of the antral phase of development. The appearance of an antral cavity starts with the development of small fluid-filled cavities that aggregate to form the antrum. As the follicular antrum grows, the oocyte, surrounded by a dense mass of granulosa cells called the cumulus oophorus which become suspended in fluid. It is connected to the rim of peripheral granulosa cells only by a thin stalk of cells. Attached to the zona pellucida, which surrounds the oocyte, is a small ring of granulosa cells called the corona radiata, these cells will be expelled with the oocyte during ovulation. In humans and monkeys, follicles pass from the preantral to the early antral stage at a follicular diameter between 180 and 250 ÃŽ ¼m (Koering 1983; Bomsel-Helmreich et al. 1979). Further, growth of the follicle is under the influence of follicle stimulating hormone (Gougeon 1996). The follicle is then termed a Graafian follicle. When the proper ho rmonal balance is present, normally one Graafian follicle in mono-ovulatory mammals (e.g. primates, ruminants, equine) and several ones in poly-ovulatory animals (e.g. rodent, porcine) fully develop and the oocyte matures and ovulate (Hafez 1993). 1.4.4 Regulation of follicular development 1.4.4.1 Oocytes somatic cell communication Oocyte growth is dependent on signals, growth factors and nutrients from granulosa cells; at the same time oocytes play an important role in the proliferation and differentiation of granulosa cells. Communication between oocytes and somatic cells have a crucial role in ovarian follicular development (Albertini and Barrett 2003; Eppig 2001). Several studies have shown the importance of oocyte-derived factors such as growth and differentiation factor-9 (GDF-9) and bone morphogenetic protein-15 (BMP-15) in female reproduction. GDF-9 and BMP-15 promote the proliferation of granulosa cells from small antral follicles (Hayashi et al. 1999; Vitt et al. 2000; Otsuka et al. 2000). Mutation of the GDF-9 gene in mice prevented the development of somatic cells beyond the primary follicle stages (Dong et al. 1996). C-kit receptor or (Kit) is expressed at the surface of mammalian oocytes at all stages of follicular development in postnatal ovaries of the mouse, the rat and humans (Driancourt et al . 2000b; Horie et al. 1991; Manova et al. 1993). An in vivo study by (Yoshida et al. 1997) has indicated the requirement for C-kit in development of the ovarian follicle in mice. In this study, postnatal mice were injected with Kit-blocking antibody ACK2, and the first wave of follicular development was studied. The blockade of Kit signalling was found to disturb the onset of primordial follicle development, primary follicle growth and follicular fluid formation of preantral follicles (Yoshida et al. 1997). On the other hand, primordial follicle formation, ovulation and luteinization of the ovulated follicle were not affected by ACK2 (Yoshida et al. 1997). 1.4.4.2 Gonadotropins Before the onset of puberty, the normal fate of growing follicles is atresia. After puberty, stimulation by cyclic gonadotropins allows the survival and continued growth with only a limited number of antral follicles that will reach the preovulatory stage. Activation and maintenance of normal follicular function is dependent on gonadotropins secreted by the pituitary. Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) are glycoprotein, secreted by gonadotrophs in the anterior pituitary under the influence of hypothalamic GnRH (Gonadotrophin releasing hormone) neurones, which regulate the synthesis and secretion of those hormones). Gonadotropins are probably not involved in the initiation of follicle growth (Wandji et al. 1992; Fortune et al. 2000; McNatty et al. 1999). Whilst there may not be an absolute requirement for FSH at these early stages the presence of FSH receptor (FSHr) in granulosa cells of immature follicles in cow (Wandji et al. 1992), human (Zheng et al. 1 996) and sheep (Eckery et al. 1997) suggests an involvement. A role for LH in the early stages of development has not been described, although expression of LH receptor (LHr) mRNA is first detected when the theca interna forms around the granulosa cells (Bao et al. 1998; Bao and Garverick 1998). FSH and LH are involved in endocrine control of follicle development, FSH stimulates granulosa cell division and the formation of glycosaminoglycans that are essential components of antral fluid (Hillier 1991). FSH is vital for the formation of the antral cavity (Nayudu and Osborn 1992) in mouse ovarian follicles cultured in vitro. Granulosa cells are the only cells in the female body possess FSH receptors, and binding of FSH to its receptor on the cell surface altered expression of multiple genes crucial to cytoproliferation and differentiation (Richards 1994). Granulosa cell genes that are responsive to FSH include: aromatase (P450arom) the steroidogenic cytochrome P450 crucial to estrogen synthesis (Simpson et al. 1994); cholesterol side-chain cleavage (P450scc) (Richards 1994) and LH receptors (Segaloff and Ascoli 1993). FSH and LH are important factors for the proliferation and survival of follicular somatic cells and the cyclic recruitment of antral follicles. Suppression of serum gonadotropins after hypophysectomy leads to atresia and apoptosis of developing follicles (Nahum et al. 1996). Whereas FSH treatment of cultured early antral follicles prevents the spontaneous onset of follicular apoptosis (Chun et al. 1996). Although FSH is the central regulator of dominant follicle survival and development, LH signalling pathways play fundamental physiological roles. LH-dependent signal pathways in the theca interstitial cells induce changes in gene expression that are critical for estrogen production (Erickson et al. 1985). Activation of the LH receptors in theca cells leads directly to the stimulation of high levels of androstenedione production. The major physiolog ical significance of this LH response is to provide aromatase substrate to the granulosa cells where it is metabolized by P450 aromatase to E2. Additionally, the preovulatory surge of LH is responsible for ovulation and corpus luteum formation. Also, LH is essential for P4 and E2 production by the CL during the early and midluteal phase of the menstrual cycle. The hypothalamus produces and secretes luteinizing hormone-releasing hormone (LHRH) into a system of blood vessels that link the hypothalamus and the pituitary gland. LHRH stimulates the pituitary gland by attaching to specific molecules (i.e., receptors). After the coupling of LHRH with these receptors, a cascade of biochemical events causes the pituitary gland to produce and secrete two hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH are two of a class of hormones commonly known as gonadotropins. They are secreted into the general circulation and attach to receptors on the ovary, where they trigger ovulation and stimulate ovarian production of the hormones estrogen and progesterone. Adapted from (Kanis 1994) 1.4.4.3 Growth factors A number of locally produced growth factors are known to be important for follicle development, they exert paracrine communication within follicles. During preantral follicle development, growth factors such as epidermal growth factor (EGF), transforming growth factors (TGF) may influence folliculogenesis (van den and Zhao 2005). Vascular endothelial growth factor (VEGF) (Danforth et al. 2003) and mullerian inhibitory substance (MIS) (McGee et al. 2001) have been reported to stimulate preantral follicle growth. It has been demonstrated that bone morphogenetic proteins (BMP) can alter bovine granulosa cell steroidogenesis and proliferation in vitro (Glister et al. 2004). Transforming growth factor-ÃŽ ² (TGF-ÃŽ ²) superfamily contains a range of proteins, including inhibins and activins. The precise roles of these factors are not known, but it is likely that they are involved in follicular differentiation by enhancing the action of gonadotropins (Campbell and Baird 2001; Knight and Gli ster 2001; Montgomery et al. 2001). Insulin growth factors (IGF) and their receptors play important role in follicle growth and development (Poretsky et al. 1999). The IGF family comprises of IGF peptides, IGF receptors which are family of proteins called insulin-like growth factor binding proteins (IGFBP) that regulate the availability of the IGF to their target cells, and IGFBP proteases (Giudice 1992). The IGFs affect biosynthetic processes in granulosa and theca cells and have an influence on mitotic activity in the granulosa cells (Giudice 1992; Poretsky et al. 1999). Additionally, a functional link between the IGF system and FSH action has been demonstrated by the finding that IGFBP-4 is a potent inhibitor of FSH