Capital Market Efficiency and Its Implication for Financial Reporting

Capital market efficiency has been a widely debated topic since the term was introduced. The efficient market hypothesis was introduced by Eugene Fama in 1970 and is one of the most important topics that is covered in financial accounting theory. There have been many papers and studies that have backed the efficiency market hypothesis. There have also been many others that have tried to show that the markets are inefficient. Are securities markets efficient or not? I believe that they are, and because they are efficient, there are multiple implications of efficient securities markets for financial reporting. In 1970, Eugene Fama introduced the efficient market hypothesis. Since there are many definitions and forms of an efficient securities market, I will focus my attention on the semi-strong form. In the semi-strong form, a market is considered efficient when security prices traded on that market at all times fully reflect all information that is publicly known about those securities. This hypothesis or theory has had many proponents for and many against it in recent years. These people have done their own studies and research on the market trying to either prove or disprove that the markets are efficient. An important statement in the definition of an efficient securities market is publically known. It focuses on the theory that the market prices are efficient and include all publicly known information. It does not rule out that some people will have inside information, and they will know more about the company than the market. Since these people know more than the market, they may be able to earn excess profits on their investments if they choose to take advantage of their inside information. While most insider trading is legal, it is illegal for insiders to trade when they trade with information that is not publicly known to further their own profits. By enacting trading laws, like insider trading, it just further solidifies that the markets are efficient. Market efficiency is a relative concept. This means that the market is efficient relative to the quality and quantity of the publicly known information. Nothing in the definition suggests that the current market prices reflect the real firm value. Due to the possible presence of inside information, for example, the market prices may be incorrect. What the definition does imply is that once new or corrected information comes along the market will adjust the prices quickly. This adjustment happens because rational investors will revise their beliefs. They will start buying and selling securities due to their new beliefs which in turn will change prices. Another important point of the theory is that investing is fair game if the market is efficient. In an efficient market there is an expected return on that security, and one way to establish the expected or normal return is by using the capital asset pricing model. In an efficient market, the investors cannot expect to earn excess returns on a security over and above the expected return of the capital asset pricing model. Under the efficient market hypothesis, a security’s market price should fluctuate randomly over time. The reason that prices will fluctuate is that anything about the firm that can be expected will be properly reflected in the price by the efficient market as soon as the expectation is formed. The only reason that prices in an efficient market will change is if some unexpected and relevant information comes along. By examining a time series form by the sequence of price changes, the time series should fluctuate randomly. A random walk is a time series of price movements that will not follow any patterns or trends and that these past movements cannot be used to predict future price movements. There seems to be an increasing number of people against the theory of market efficiency including Professor Charles Lee (2010). He states that the market efficiency has its limitations. He uses the United States housing market as an example of a market that seems to have been dominated by greed. He believes that emotions now dominate the markets and assist in setting the prices in the securities market. The other emotion that he points out is that of fear. The unwillingness to grant credit and to take risks are direct results of fear. Since these emotions dominate people’s actions, the markets are not as efficient as originally thought. Shiller (1984) created a model which featured two types of agents. The two types of agents are â€Å"smart-money† investors and noise traders (ordinary investors). The smart-money investors focus on fundamental information and react quickly to news about fundamental information in an unbiased manner. Noise traders are vulnerable to fads and may also overreact to news. Noise traders may also trade for consumption-based or liquidity reasons. Since there are noise traders in the market that assist in driving prices, the markets are not completely efficient. Critics of market efficiency also point out that there are several recent instances where the market prices must have been set by psychological considerations instead of by rational investors. The first example is the stock market crash of October 1987. During this crash, the general economic environment stayed the same, but the stock market lost about one-third of its value. A second example is the Internet â€Å"bubble† of the late 1990s. The values assigned to high-tech and Internet related companies were inconsistent with rational valuation. In looking at market efficiency, any large swings upwards or crashes downward that do not have related unexpected information can be signs that the market is not efficient. Despite these cases and examples of reasons that the market is inefficient, I believe that for the most part the market is efficient. It is not completely efficient, nor will it ever be, but for the most part the securities are properly priced. I believe that if the market was not efficient, there would be more professional investors that would be able to beat the market as a whole. I believe that with the information and the speed with which it is available today it is more efficient than in 1970 when Fama first introduced market efficiency. I do agree with the notion that there are some people who invest with emotions. When you talk to people about a company such as Apple, you will find just as many people who â€Å"love† the company as you will who dislike it. My feeling is that most of the emotion trading will for the most part cancel out and will not represent enough trading to dramatically adjust market securities prices. There are many fund managers who believe that they can outperform the market. Efficient markets depend on these participants who think that the market is inefficient and trade in the market in an attempt to outperform the market. Jensen (1968) performed the first study of mutual fund performance. He found that active fund managers underperformed the market and were unable to add value. In my personal research, I have found that when looking at â€Å"professional† analysts opinions, they are all over the board. My belief is that fund managers should focus more on correctly diversifying people’s portfolios than suggesting and trying to get them to invest in securities that they feel are undervalued. In order for the market to be efficient, the arket must be able to quickly analyze and adjust prices for new information. Nowadays with the Internet, investment journals that come out daily, and television shows and channels related to securities markets, the markets are more efficient than in the past. An example of the market being able to react quickly was in the article â€Å"The Stock Price Reaction to the Challenger Crash: Information Disclosure in an Efficient Market. â€Å" Maloney and Mulherin found that â€Å"the market pinpointed the guilty party within minutes. Regardless of whether you agree with the efficient securities markets theory or not, there are many implications of efficient securities markets for financial reporting. In W. H. Beaver’s article â€Å"What Should Be the FASB’s Objectives†, he outlines four implications. The first implication is accounting policies adopted by firms do not affect their security prices, as long as policies are disclosed. The accounting policies have no differential cash flow effects, and the information is given so readers can ea sily convert across different policies. The policy that is chosen will affect the reported net income, but it will not directly affect future cash flows and dividends. The efficient market is not fooled by different accounting policies when securities of firms are compared. The second implication is that efficient securities markets go hand in hand with full disclosure. Management should report firm information if the benefits are greater than the costs. Investors use information that is available to them to improve decisions in market efficiency. Confidence in the securities market will increase because of the information available. An important standard of full disclosure is Management Discussion and Analysis. The objective of MD&A is to enhance investor understanding of the issuer’s business by providing supplemental analysis and background material to allow a fuller understanding of the nature of an issuer, its operation, and known prospects for the future. The third implication is that market efficiency implies that financial statement information does not need to be presented in such a form that everyone is able to understand. The majority of investors are educated and will understand the information as presented. They are the ones who buy and sell and will move market prices to an efficient level. Naive investors are then price-protected since they can trust the efficient market to price securities. The final implication is that accountants are in competition with other information providers. With new pertinent information investors will change their beliefs. This revision of beliefs is a continuous process. If accountants did not provide useful, cost-effective information, the usefulness of this function would decline to other information sources. Accounting information is generally useful to investors. The theory of efficient securities markets has been around for more than forty years. The concept should be around for many years to come. As in all theories, there are people that will continue to try to further prove the theory and people that will work to disprove the theory. From all available information and from my experience, I believe that securities markets are efficient. Due to the efficient securities markets, there are many implications for financial reporting.

Hyten Corporation Essay

Abstract: The structure of this assignment is such that the questions are not just answered directly but that there is a discussion of general premises by the author prior to confronting the complexities of systems re-engineering. The reader is given a few short philosophical insights into the author’s assumption in the â€Å"preferred method† of such organisational change. It is the focus of this assignment to impart how the organisational change will lead to the organisations culture changing. In the second question which is what is to be done to solve the problems and priority I have referred to the problem statements in the first question per number in the first question and then rated them in priority. The author has chosen this method of answering for the sake of continuity and ease of reading. General Discussion:Prior to answering the questions posed in this case study the point of departure will be discussed. Change is ongoing in any organisation and this is to be a managed process. The need for change should be clarified and has to be analysed, the new goal clearly laid out, the change effected and then the whole change measured against the goals initially stated. Then one can see if a new change or further change is necessary. These processes are laid out in Dr. E. Goldratt’s book the Critical Chain as The Theory of constraints. Harvard Professor J.Cotter outlines 8 steps to bridge the change gap. These steps as shown in the following illustration bridge the gap between the current state and the desired state. As in Cotters first step the managers of the company under discussion in the case study are indeed ready to be convinced that current methods are not working effectively and efficiently. The critical mass has been achieved within HYTEN to effect the necessary change. Within HYTEN the emphasis in leading the change should be on the premise that  humans have natural in born strengths and will execute and implement things in a fashion that allows them to express this natural style. The best that managers can do is to take cognisance of this strength and play on those strengths in the individual. To take this assumption a step further in proposing the hypothesis that certain environments and cultural backgrounds assist individuals to develop certain skills. HYTEN has already shown the ability in its past to adapt to changing macro economic climate when it re-tooled and changed production after the first Gulf war. This was very successful in the longer term. This is a positive indication that human resources will change without too much disruption to productivityQuestion 1:Problems1.The company uses an informal project management model and the manner in which new projects are tackled is not as orderly as it could be. (In the complex environment of tight schedules and multi-disciplinary teams the carefully documented and well managed project will mean that ambiguities and duplications will be greatly reduced. The project manager must provided the adhesive force for this team.)†¢This is an architectural problem2.The company has been very successful and managers have been promoted swiftly hence, this relatively young company grew up around the managers. (This has had a positive effect in as much as the managers have become senior manag ers relatively quickly but has also meant that the managers have become complacent and secure in their environment. There also has been no introduction of new blood into the senior management and thus this inbreeding has the effect that cross-pollination with other companies is not happening.)†¢This is a behavioural problem3.The managers for their part are relatively well educated but seem to have become complacent, they have stagnated and failed to study further and thus have not been exposed to some of the newer methods of business structuring/management. The focus of these managers seems to be on technology. (The focus on technology for technology’s sake is not a good thing. In this type of industry it is understandable that managers get caught up in the core function of the business. But the managers can not neglect studies in other fields or fail to focus on neglected areas)†¢This is a behavioural problem4.The business development unit is seemingly ineffectual. The comment that they appear to  be fixing the areas which are not broken seems indicative of the errors they are making. (The business development unit is seemingly not focusing on their core function and is neglecting key performance areas. They are not promoting the efficient running of projects and internal policies. In fact they are having the worst possible effect on the company image by making promises that are unachievable and unrealistic.)†¢This is a behavioural problem5.†The customer has little control over funding, manpower or work done.† This on its own is an over sight as the customer is king. He is the sponsor and as such should demand that the resources and work should follow the projects need as both resource demand and funding are provided by him. This will mean that the production will be a push type and not a pull type.(No further comment or explanation needed here) This is a behavioural problem (Perhaps stemming from the fact that HYTEN was used to â€Å"bit work† for the military.)6.Marketing and sales do not have a say as to what projects will fly and what won’t. (This seems strange as these are the very persons that have front line contact with customers and potential customers and they may see the demand for a particular product.) †¢This is both an architectural and a behavioural problem7.The fact that the authority, role and function of the business development department has gradually expanded means that there are no clear definitions or mandates given to these important project managers. That a charter has not been set up is an indication that senior managers lack the will to tackle functional managers. †¢This is an architectural problem8.No design freeze on products. (This can be very trying for production)†¢This will cause operational problems but the cause is behavioural9.Production items not 100% are being reworked and there seem to be many no-go products being reworked to the determent of products in the system for the first time. (Dr. E Goldratt’s Theory of constraints)†¢This is an operational problem10.There seems to be a big emphasis on the project manager being technically competent and having intrinsic knowledge of technical detail. The other characteristics that are high on the agenda are work assessments of individuals taking part in the project. †¢This is a behavioural problem11.The HR manager is very concerned that the  performance of individuals is correctly captured between the functional manager and the project manager. Sometimes a manager can get a gut feeling about an employee and not be able to document the actual capacity of that individual fully. †¢This is an architectural problem12.The cited problem of an employee at another company not gettting an increase in line with work carried out or that this employee was functioning at a higher level than for which he was employed initially are smoke screens for a basically unsound opportunity and promotion policy at that company and can be avoided by installing proper policies. (Dearth of promotion and training policies) (Quite poignant that the one vocalising these words is the very person who should have the answers. )†¢This is a behavioural problem13.Harold Grimes the plant manager vocalises that internal personnel should be promote to the position of project manager for this new big project as they will have insider knowledge, this is not an on going item like production and as such is a once off situation. His assertions may lead to great unhappiness of the individual placed in such positions. †¢This is not a problem yet as this has not happened but predictions are that this will become a problem in a few years time should this course of action be followed. 14.Herman Hall the I.S. Manager thinks only in terms of what computer package is needed for reporting.( The throwing of software solutions at system problems is very common as the managers attempt to avoid real issues and substitute/relegate control to software.)†¢This is a behavioural problem15.The adaptability of the IS department is very poor as they don’t even consider â€Å"of the shelf solutions† or outsourcing assistance. †¢This is a behavioural problem16.Bub Gustwell Scheduling director for all his good sentiments sees the project management way of managing purely as a vehicle to better schedules. †¢This is a behavioural problemSummaryThe tally of current problems is 15 (One  is a potential future problem) this is not the full tally of all the problems or permutations of problems but the major problems have been highlighted. The score is as follows:Behavioural problems10 1/2Architectural problems 3  ½Operational problems1As is evident from the graphic above the overwhelming problems of HYTEN are behavioural. Having said this the corporation is very successful in a competitive environment. The number of changes are relatively few if one considers the size and extent of the organisation. Question 21-The company not formalising the project management approach is one of the root causes for many of the other ailments, this needs to be addressed as follows:†¢Project charter established for each project†¢Standing of both project managers and functional managers to be clearly laid out†¢All staff working on projects should be briefed on the role that they are to play and duration of their service on that project†¢An exit strategy defined up fount2-The successes of the company and the long serving senior managers: Remedial action to the stagnation of the senior managers could be as follows:†¢Training of existing managers in up-to-date business methods †¢The implementation of a succession policy†¢The introduction of some new managers from other companies†¢Employment of consultants/specialists to re-engineer the corporation3-The failure of managers to keep up to date with studies: This was given a passing mention in bullet point 2†¢Studies in relevant fields other than technology could be arranged by the corporation†¢ Workshops on emergent business methods should be held†¢Subscriptions to relevant business and technology periodicals should be procured for all senior managers and a rotational roster of such periodicals for more junior manages and staff. †¢Establishment of a news server in house where matters can be discussed e.g. troubleshooting, innovations etc.. 4-Ineffectual business unit:†¢The whole business unit needs to scrutinised as to function, this may be outsourced†¢This unit needs to revert to the core function as it has drifted5-The control that customer has over funding and  resources: This needs evaluation and through consultation with stake holders a new level of customer involvement can be reached. The recommendation is that a customer evaluation program be started and that the areas indicated by the customer as high priority be addressed. Not to pre-empt such a program the corporation needs to open communications channels with the client and actively market a positive image to off set the negative one. 6-Marketing and sales not having a say: This ties in with bullet 5 and the marketing and sales should be found to be repeating what the customer is saying. It is not so much a matter that the sales or marketing is not being hear but that the customer is not been heard. Once the customer evaluation of the company is complete the results must be implemented. There after the evaluation forms should be issued with each customer transaction. 7-Expansion of the business development unit:†¢This matter was touched on in bullet 4 with a recommendation that this function be outsourced once it is clearly defined within the corporate structure†¢The right sizing of this department is a second option to outsourcing†¢The outsourced business development unit should be given measurable objectives and clear brief8-Design freeze of products: The fact that there are constant changes in design is a clear indicator that the customer and stake holders are not involved and are not articulating their needs †¢Once better lines of communication have been established with stakeholders design will be reached by consensus, expensive re-tooling for design change will be greatly reduced9-Rework of unsatisfactory items:†¢This can be reduced by continuous quality control. In other words the point of manufacture must be the quality controller thus work pieces would not have to counter-flow to the production line and rework would be immediate†¢Dr. E. Goldratt proposed the critical chain theory where the weakest segment of the chain is targeted and improved this is then repeated till the system is running optimally10-The emphasis on the technically competent project manager: This is just plane nonsense as the team is made up of multi-disciplinary specialists. The only step needed here is to clarify this in the project charter. 11-Concern that staff are to be graded by two managers: On the whole a poor  employee will be seen as such by both managers. The converse being true as well. Having stated this it should be easy enough for each manager to rate the employee and an aggregate be awarded between the two managers on the Key performance areas and the various related weighting for those areas12- Employees not getting equitable increases between plants:†¢This is as described in bullet 11 – The job evaluations and job weighting systems must be overhauled then the system of KPS and weighing need to be put into practice to assess which team is the most productive. It is flawed to award employees differing increases within a work unit. Best practice is the fixed bonus system were there is no separation between rank or individual13-The promotion of only internal staff due to insider knowledge: This is not a problem as yet but may become a problem in future as it may cause a situation of inbreeding. This situation can be remedied easy by correcting the perception early14-The computer package which is the universal panacea:†¢This is yet again a perception that must be corrected early. As any package must follow the real world model and as such the real world model must work first. †¢The systems approach is governed by policies and methods these must be implemented fully and not be sitting on a disused shelf. 15-The adaptability of the IS department:†¢The IS department must be told to evaluate off-the-shelf solutions before considering other alternatives†¢The IS department must ensure that options for roll out of new solutions consider the possibility of out-sourcing16-The perception of persons that project management is only schedules:†¢The only way to change this perception is through educationPrioritization of remedial action and problemsThe first priority is to change the current state of the senior manager studies, once these key persons change their outlook and approach bullet point 3, 2, 5, 6 and 16 will be resolved. The education of managers to a new business approach can not be under stated as they will see the need for customer involvement and even community involvement, the balanced score card will become an intrigue business tool. The changing of the business culture will be then a natural and easy process. The managers will be secure in their positions and will not feel threatened by the change, in fact they will see  the rewards and start to implement the change from within. Second priority is formalisation and implementation of the various company policies which impact on the individuals and structures within the corporation. This must be done in conjunction with the shared vision of HYTEN corp. and thus the corporate strategy will be defined in the process. These are the policies which affect:1-Staffing pay progression and bonuses2-Formalisation and introduction of project management and project charters3-The scope and powers of the business unitsThe systems approach to the documentation and formalisation of the policies and strategic goals will remediate the ills in bullet points 1, 4, 11, 12 and 14Third priority is the resolution of the functional issues such as reworked items, design freeze and others. These issues are of minor concern in relation to the other items which cut right to the core of the problems. The bullet points 8 and 9 are addressed in this priority. The remaining bullet points not dealt with are not preserved to be priority issues but never the less should be dealt with as a matter of course in the manner laid out in the bullet points above. Some are misconceptions others are a lack of insight thus need to be quickly remedied. 4-ConclusionThe over view of this company is that it is in good condition currently but will not stay in that shape if it doesn’t continue to evolve. Many of the points raised as problems are inter-related; this is highlighted throughout the bulleted points. Intervention in some areas will have to be great will in others it is minimal. The one overarching factor needing change is the ongoing education of senior managers. This company is ripe for change and has many eager young individuals who need development. The Policies are basically sound but need to be revisited both for updating content and implementation. If the changes are implemented HYTEN Corp. will go from strength to strength. Bibliography: †¢15th March 2006, The Eight-stage Management Process of Major Changehttp://www.freequality.org/sites/www_freequality_org/Documents/knowledge/ManageChange_MiniTutorial_MT%20_2_.pdf. †¢Program Managing Organizational Transformation, Change and Performance Improvement. Prof. Pieter Steyn and Erik Schmikl†¢The Critical Chain, Dr. E. Goldratt 2nd edition

Debate on School Uniform Essay

Today we are seeing that the younger generations are becoming more preoccupied with fitting into the latest fashion trends. School administrations have noticed that dress code violations could be an attribute to the lack of performance in the classrooms. Public schools across America are searching for answers to enhance a better learning environment for the students. Taking all this into consideration, school uniforms would be a great idea to alleviate some of the negativity kids face due to societies apparel obsessions. In addition to what has been mentioned, studies have shown positive results with the use of public school uniforms. If it means that the schoolrooms will be more orderly, more disciplined,† Mr. Clinton said, â€Å"and that our young people will learn to evaluate themselves by what they are on the inside instead of what they’re wearing on the outside, then our public schools should be able to require their students to wear school uniforms (Mitchell, 1996). I believe a requirement of school uniforms should be implemented in all public elementary and middle schools. Read more: Should uniforms be mandatory essay In the name of putting â€Å"discipline and learning back in our schools† President Clinton instructed the Federal Education Department today to distribute manuals to the nation’s sixteen thousand school districts advising them how they can legally enforce a school uniform policy. If it means that the schoolrooms will be more orderly, more disciplined,† Mr. Clinton said, â€Å"and that our young people will learn to evaluate themselves by what they are on the inside instead of what they’re wearing on the outside, then our public schools should be able to require their students to wear school uniforms† (Mitchell, 1996). â€Å"It’s a fashion trend that’s spreading from Los Angeles to Louisiana, from Maryland to Miami, public schools are discussing, and in many cases adopting, the old private school idea. School uniforms are designed to help kids focus on algebra instead of high-tops; to make students compete for grades rather than jackets (www. pbs. org). In 1987, the first public school Cherry Hill Elementary in Baltimore, MD instituted a school uniform policy. Later in 1994, the Long Beach Unified School District in California adopted a mandatory uniform policy in some of its schools, making it the first urban district to do so. Before long there was a considerable increase in the use of uniform. For example, ninety-five percent of New Orleans’ public schools require uniforms, eighty-five percent of Cleveland, eighty percent of Chicago, sixty-five percent of Boston, sixty percent of Miami, and fifty percent of Cincinnati’s public School changed to uniforms (www. education. org). New York City, which is the largest school district in the US, has adopted the school uniform policy. The largest school district in the U. S. has adopted school uniforms. Over a half-million elementary-school students in New York City will have to adhere to a dress code by the fall of 1999. The president of the school board said the policy is â€Å"important to diminish peer pressure and promote school pride,† but that it’s not â€Å"an act of magic to transform schools overnight†¦ It isn’t going to replace a good teaching, good principals, and small classrooms. †(www. pbs. org). The National Association of Elementary School Principals (NAESP) conducted a phone survey of seven hundred and fifty five principals in 2000, which revealed that twenty one percent of all public schools had a uniform policy (www. education. org). Another reason that schools have decided to conform to uniform policy is because some students arrive at school in T-shirts that bear slogans or graphics promoting drugs and alcohol, or that display a variety of messages that conflict with values the schools are trying to promote. Others may swagger around the halls in gang-related garb. Also, others may show up in sexually provocative clothing. These issues, as well as a desire to minimize socioeconomic tensions between the â€Å"haves† and â€Å"have not’s†, have spurred some schools to adopt more stringent dress codes or to require students to wear uniforms. As the Department of Education’s Manual on School Uniform notes, â€Å"Uniforms by themselves cannot solve all of the problems of school discipline, but they can be one positive contributing factor to discipline and safety† (Lumsden, Miller, 2002). Some authors contend that uniforms lessen emphasis on fashion, reduce the financial burden of low-income families, and promote peer acceptance, school pride, and learning. In a ten-state survey of elementary and middle school principals conducted two years ago by the National Association of Elementary School Principals and the clothing company Lands’ End, eleven percent of respondents said that their schools mandate uniforms, and another fifteen percent were considering such a policy. Others recent survey indicated that support for uniforms are growing among parents as well. In one survey, fifty-six percent of parents said they would support a school uniform policy (Lumsden, Miller, 2002). School uniforms also take the pressure off students to pay top dollar for clothes, according to Reginald Wilson, a senior scholar at the American Council on Education in Washington, D. C. â€Å"I think it does lower the cost of clothes, and kids don’t emphasize clothes as much when they’re all wearing the same thing,† Wilson said. â€Å"Certainly the competition to wear the best shoes or the best sweaters and so forth has been prevalent in school ever since I was in school, and the poor kids felt inferior† (www. pbs. org). Deborah L. Elder wrote about an evaluation of school uniform policy at John Adams and Truman Middle Schools for Albuquerque public schools. In the beginning in the fall of 1998 under a policy started by parent’s students at John Adams and Truman Middle Schools in Albuquerque were required to wear tuck-in polo shirts and khaki pants or skirts. Elder reports on an evaluation of this policy that used interviews, focus groups, and surveys, along with data on discipline referrals and numbers of students achieving honor-roll status. During the first semester of the 1998-1999 school year, both schools experienced a clear improvement in student conduct from the previous year. At John Adams Middle School, discipline referrals fell from one thousand five hundred and sixty-five during the first semester of the previous year to four hundred and five. At Truman, referrals dropped from one thousand one hundred and thirty-nine to eight hundred and fifty. Students, teachers, and parents stated in interviews â€Å"uniforms place all students on an equal level,† Elder writes, â€Å"Students who may be immediately labeled by peers and staff no longer stand out. † Survey data showed that seventy-five percent of parents and eighty-nine percent of staff supported uniforms and believed they decreased violence, theft, and gang activity, Although only fifteen percent of students supported uniforms, fifty-nine percent agreed that â€Å"school uniforms help school officials identify trespassers on campus. † Concerns about school violence have led to increased interest in and acceptance of uniform policies. In the wake of school shootings, communities and schools are much more willing to embrace uniforms as well as a number of other strategies to enhance student safety. Curbing gang-related violence was the primary goal of the Long Beach (CA) Unified School District when, in 1994, it began requiring students in all its elementary and middle schools to wear uniforms, In the Dysart Unified School District outside Phoenix, Arizona, eliminating some of the stigma associated with clothes was the main motivation behind the adoption of uniforms. Even before the recent series of school shootings, a survey of principals conducted by the National Association of Secondary School Principals found strong support for uniforms. In addition to having a sense that uniform may aid in violence prevention, many administrators believe that uniforms will reduce discipline referrals, while improving attendance, achievement, self-esteem, and school climate. A study of middle school students in the Charleston (SC) School District fount that school uniforms did appear to alter students’ perceptions of school climate. Students attending district schools that required uniforms viewed their school climates more positively than did students enrolled in schools where uniforms were not mandatory. Additional benefits credited to school uniforms include improved discipline, increased respect for teachers, increased school attendance, fewer distractions, improved academic performance, increased self-esteem and confidence, lower overall clothing costs, promotion of group spirit, reduction in social stratification and fashion statements, improved classroom behavior, lower rates of school crime and violence, and easy identification of nonstudents (Lumsden, 2001). Many opponents believe that dictating what students wear to school violates their constitutional right to freedom of expression (Lumsden,Miller, 2002). People oppose uniforms point to unnecessary violations of students First Amendment rights, authoritarian regimentation, extraordinary expenditures on special clothing, an environmental tone that is harmful to education and learning, and cosmetic solution to deeper societal problems. Students First Amendment right to freedom of expression, and whether it is being abridged, is one of the fundamental issues raised, Several legal challenges have asserted that students freedom to select what to wear to school is a form of self-expression that schools are not entitled to interfere with (Lumsden, 2001). In a recent case, Littlefield v. Forney, parents challenged a school uniform policy adopted by the Forney, Texas school board. The policy required students to wear polo shirts, oxford shirts, or blouses in any of four specified solid colors, with blue or khaki pants, shorts, skirts, or jumpers. Denim, leather, suede, vinyl, and spandex were off-limits, as were baggy clothes and specific types of shoes. The parents claimed that the district’s policy violated â€Å"the right of parents to control the upbringing and education of their own children. † The plaintiff also argued that the policy interfered with students’ freedom of expression and forced them to express ideas with which they might disagree. In addition, they also declared that the procedures for opting out of the policy violated their religious freedom by allowing school officials to assess the sincerity of people’s religious belief. The federal district court dismissed the suit without a trial, but the plaintiffs then appealed to the 5th Circuit Court, where the ruling of the lower court was upheld. In its decision, the 5th Circuit Court indicated that students’ free-speech right to select their own clothes is â€Å"not absolute,† and that this right must be balanced against a school board’s stated interests in adopting a dress code or uniform policy. To decide whether a specific uniform or dress code policy is permissible under the Constitution’s free-speech clause, the court used a four-pronged test it had previously applied in another school uniform case, Canady v. Bossier Parish School Board. The court looked at four criteria: the school board must have the power to make a policy, the policy must promote a substantial interest of the board, the adoption of the policy must not be an attempt to censor student expression, and the policy’s â€Å"incidental† restrictions on student expression must not be greater than necessary to promote the board’s interest. In this case, the 5th Circuit found that all four criteria were satisfied and that the district’s school uniform policy therefore did not violate students’ right to free expression. The court also ruled that parents’ rights to control their children’s upbringing, including their education, cannot override school rules that are considered â€Å"reasonable† to maintain an appropriate educational environment. In this case, the court concluded that the uniform policy was â€Å"rationally related† to the interests of the school board in â€Å"promoting education, improving student safety, increasing attendance, decreasing dropout rates, and reducing socioeconomic tensions among students. † The parents’ argument that the opt-out procedure violated religious freedom because if gave school officials the authority to judge the sincerity and content of families’ religious beliefs was also rejected by the court. Their decision was based on the policy not containing any religious goals; they did not have the effect of advancing or hindering any particular faith over any other; and did not excessively â€Å"entangle† school officials in religious beliefs (Lumsden, and Miller, 2002). Public schools that have already put uniform into place have seen improvement. Kids are less focus on what they are wearing, and more focus on schoolwork. Kids are not focused on what they should wear the next day for school and you won’t have kids up early looking for clothes to wear to school. Elementary and Middle Schools will see significant change once uniforms are put into place. School uniforms are a great way to preserve the level of social equality amongst the students. The thought of knowing the social background is prevented. It makes kids treat each other equally; not judging by what clothes they wear. Students will learn to respect each other on the foundation of how they get along and not how sexy they look. Humiliating or bullying other kids will decrease or stop altogether. The level of distraction is considerably reduced. Since students will be dressing in similar clothing, which will be distinctive to the school, the students will build up a sense of belonging and loyalty to the school. School uniforms will help avoid incidents of complicated situations (inferiority and superiority). Students will not be known by what they wear, but by how they perform. Kids can build team spirit. When you wear specific colors, a sense of unity can be developed. Similar clothing promotes team spirit. School uniforms encourage a sense of ownership and discipline. Therefore, I strongly believe school uniforms should be a requirement for public school students in the elementary and middle schools. Overall, implementing school uniform in elementary and middle public school will be beneficial, as I have mentioned above. Kids may not be happy about it at first, but they will eventually catch on. I personally work with middle school kids who go to public school and wear uniforms. They did not like it at first, but what they all agree on is how they don’t have to decide on what to wear. References Lumsden, Linda and Gabriel Miller. â€Å"Dress Codes and Uniforms. † 2002. National Association of Elementary School Principals, Alexandria, VA. 19 6 2012 . Lumsden, Linda. Uniforms and Dress-Code Policies. Eugene, May 2001. Mitchell, Alison. New York Times: Clinton Will Advise Schools on Uniforms. 25 February 1996. 23 June 2012 . Public School Uniform Statistics. 2012. 19 6 2012 . School Uniforms. 21 6 2012 .

Neoliberal Transition in Latin America Essay Example | Topics and Well Written Essays - 3000 words

Neoliberal Transition in Latin America - Essay Example Economic integration between countries will be examined to see if any neo-liberalism is taking place within the regions of Latin American countries. Discussion includes analysis of manufacturing products and those based on renewable resources mainly in relation to regional development in Chile and the growth of non-traditional exports and labor markets. The paper first examines the origins and thought processes of neo-liberalism. Neo-liberalism maintains people act according to self-interest and that markets yield the most efficient outcome by free trade balances within liberalized capital markets with minimal government intervention in the economy. Karl Marx developed the theory that under capitalism, technical and distributional changes tend to follow specific patterns of evolution. This course of changes coalesces the expansion of output, capital, and employment. (Other mitigating factors include the rise of labor productivity, the real wage, and the capital-to-labor ratio.) Further in the evolution lies difficulty to sustain the progress of labor productivity without resorting to increased amounts of capital investment. The decline of the profit rate creates the conditions for large crises resulting in recessions and unemployment. (These movements and tendencies occur at declining rates of variation (Dumenil & Levy, 2004). Marxist economics is deeply rooted in many Latin countries  and enjoy a strong historical foundation; however, â€Å"with the rise of the Cold War and the increasing United States’ hostility toward  anything remotely progressive, the left in Latin America was first, mildly, and then severely repressed. The list of casualties includes The Arbenz regime in Guatemala; Goulart in Brazil; Allende in Chile and democracy in Uruguay and Argentina† (Noble & Weinstein, 2005).   

Applying Social Influence Theories Essay Example | Topics and Well Written Essays - 500 words

Applying Social Influence Theories - Essay Example The message chosen to advertise this product is based on people’s need to confirm to their self – assigned roles of conservationist, environment conscious person; green warrior; or providing care-giver. It would go something thus: â€Å"You are amongst those people who are attempting to help the environment in so many small and big ways. You love the planet; and so do we. You want to make the world a better place; and so do we. Our little contribution is this range of organic snacks; developed from sustainable products all through. These recipes draw inspiration from age old traditional snacks across ethnicities. Our snacks are healthier, more nutritious, while being just as tasty as other competing brands. And as a bonus; they will help you protect the environment as well. Even the wrapping is eco-friendly! Yes, they have a shorter shelf life; but that won’t matter sine they will be long gone before that date. So help us help you make this world a better place. Question 2 Social influence is the process of affecting the opinions, attitudes, behaviors and desires of a number of people through the use of persuasive messages. This influence need not always be exerted in the first person; and can be done through the media in order to reach a large number of people.

Performance and reward management Essay Example | Topics and Well Written Essays - 3000 words

Performance and reward management - Essay Example What is required in this day and age is a vision to set things right and that too in the long run scheme of things. The payroll costs are decreasing and so are the cuts within the performance rewards for the sake of the employees. This is because the payroll costs have meant an extra burden on the organizations and add to that the discussion of the performance rewards is something that is completely out of sync with the understanding that one reaches upon. Therefore, what is deemed as significant here is the reckoning that performance rewards will give in the best mileage if these are handled in a proper and adequate way, and when the organizations understand that the employees are their most prizes resources, and giving them incentives would only mean more and more success at the end of the day. This paper discusses why payroll costs are a burden on the shoulders of the organizations in the current times and how the performance rewards are discerned and measured in the same perspect ive. The payroll costs within the organizations could be brought down if there is a sense of purpose and collective responsibility within the top management domains to make the same as a possible initiative. What this suggests is the fact that organizations in this day and age are doing their utmost to make sure that the payroll costs are brought under the hammer but what they are forgetting all this while is the understanding that these elements need to be tackled in a proper perspective and with immense foresight. More than anything else, there is a need to set things right which unfortunately the payroll costs and deductions in the same might not fulfill. Therefore, one can deem the same comprehensions to be out of sync because the employees are looking to expand on their salaries through pay raises and the like but what the organizations are looking forward to offering them are totally opposite pay structures (Heyes, 1996). However balancing the two seems like a difficult exerci se, and more so when the talk goes out loud regarding the payroll costs being a massive burden on the organizational shoulders. Therefore, much consideration is indeed important towards the relevant domains because the organizations of today are banking direly on the positives that the employees can incorporate within their ranks. The payroll costs are important to have know-how about because these form the essence of an employee’s realms and he would never appreciate if these are cut down for no mistake of his (Poole, 1998). When the payroll costs are thought of as a burden, then the organizations cannot derive much sanity from the related ranks. Hence it is always a good practice to think of these payroll costs in the light of the money spent on the resources which are available at the disposal of the organizations, and it is this arsenal which forms the backbone under the related scenarios. The changing business environment circumstances usually implicate for the discussio n on payroll costs coming to the fore. What this suggests is the fact that the payroll costs would be seen as a burden on the shoulders of the organization and that the employees would view the entire ballgame of salaries and pays to be a difficult task for the sake of the organizational top heads. They would find it hard to arrange for their salaries which would eventually mean that the employees

Human Resource Information Systems Essay Example | Topics and Well Written Essays - 1750 words

Human Resource Information Systems - Essay Example The HR departments came under pressure with routine work trying to cope with administration and providing more services online, that they could not provide value-added services such as knowledge management, culture management, and strategic direction and renewal. Gradually the focus shifted from playing a purely technical administrative role to being actively involved in the strategic planning and management of an organization. It became essential to add value to enhance competitive advantage. The second perceived need was to incorporate IT in HRM practices. HR functions were transferred to digital formats and even though technology is underutilized, it is increasingly being used in functions such as recruitment, selection, training, promoting, terminating and in complying with legal requirements. IT systems led to the introduction of e-HRM which saves time and costs particularly with online recruitment and training systems. While HRIS can bring substantial savings to an organization , it is necessary that the managers and employees understand the benefits of the new system and are actually ready to use it. Getting the system to adapt to a new system is the greatest difficulty according to Beulen (2009). E-HRM can increase the amount of information provided to people as they obtain online access to HRM policy and practice handbooks. Online notification of holidays and other events facilitate strategic processes while people can even register for training courses online (Paauwe & Farndale, 2004, p11). E-HRM enables help people be constantly ready for change while encouraging online training and learning activities. It also facilitates collaboration between individuals through discussion groups and video-conferencing. It is also known to enhance employee interaction, work-life balance as they can deal with certain personal tasks while at work. In addition to improved accuracy, timely and

Coordinated management of meaning theory Essay Example | Topics and Well Written Essays - 500 words

Coordinated management of meaning theory - Essay Example It is but natural that the two cannot walk together, unless they are agreed. No coordinated action is possible when the viewpoints are divergent. No one is individually responsible to construct a social situation. A problem surfaces on account of friction and interaction of conglomeration of issues in a group situation. Proper response to such issues can only be through consensus. But social realities often hinder such a possibility. A symposium was held recently in the Community Hall at Houston(TX). Local politicians, police officers and some NGOs who represented the interests of women participated in the symposium. The issue for discussion in the symposium was â€Å"Women safety, how to challenge increasing rape cases.† Initiating the debate the women representative said, â€Å"The politicians and police are responsible for the present state of affairs. No woman feels safe in cities. Police have no control on the issue and the politicians are not serious about it. The judiciary is helpless and the cases in courts linger on for years.† Even as she continued with her angry outburst, the senior police officer intervened. â€Å"Our department is not responsible for increase in rape cases. The moral fabric of the society has been torn asunder. The available security force with us is totally inadequate. The above observations were immediately contested by a police official. â€Å"We are not corrupt. If we receive a complaint against any police personnel, we take action as per disciplinary proceedings rules governing the police department. We are only the investigating agency in rape cases. For delay in the cases and for awarding punishment, we alone are not responsible. Often political pressure stalls the speedy investigation.† Here is a situation that explains the manner in which social words are created. This juncture can be as the point of creating social words. Our social words are created as per the demand of the

Operations Strategy Of Samsung Group Essay Example | Topics and Well Written Essays - 2000 words

Operations Strategy Of Samsung Group - Essay Example To remain on a customer’s shortlist, a company has to qualify and re-qualify all through the customer decision making process. Failure to compete at any of these stages would render the firm unable to compete in the rat race. Order winners and qualifiers are both market specific as well as time specific and thus would vary from market to market and also change from time to time. Bozarth and Handfield have opined that order winners are those performance dimensions that differentiate a company’s products and services from its competitors’. Firms win the customer’s business by providing superior levels of performance on order winners. On the other hand, order qualifiers, as stated by Bozarth and Handfield are performance dimensions on which customers expect a minimum level of performance. Superior level of performance on an order is not likely to give the company any competitive advantage.Skinner has been of the opinion that the competitive criteria for a man ufacturing strategy may include the following:†¢ Quality: Manufacturing of products with high standards performance and conformance with high quality †¢ Delivery speed: Meeting of delivery schedules set by the management†¢ Delivery dependability: Responding promptly as well as efficiently to orders from incoming customers†¢ Flexibility: The ability to modify designs as per the needs of customer and react to changes in product and product mix of the firm

Strategic human resource management -2.2 Essay Example | Topics and Well Written Essays - 1000 words

Strategic human resource management -2.2 - Essay Example This orientation is important as it may be reflected in the training, socialization and attitude of the new employee affecting the performance of the organisation. The goal of Natural Knibbles is to create a company that provides attractive place to work, helps employees to fully utilise their potential  and  offer  secure,  long-term  employment  (Stone,  2008,  p.375).  The orientation program helps in portraying this image of the company. First, the orientation program provides a complete description of the environment and culture at Natural Knibbles. Second, important information related to the job such as responsibilities and duties is explained providing on-the-job training to the new employees under a process called ‘buddy system with experienced employees. Thus, the orientation program allows the new employees to explore their skills and abilities in a new environment which adds to the value and growth of the employees. What forms of training and devel opment do you believe would have been beneficial to (a) Kane (b) Lisa following their initial experiences at Natural Knibbles? According to Nankervis et al. (2011), the aim of training is to provide or maintain effective job level performance to achieve goals of organisation as well as personal. Given that Lisa and Kane were new entrants in the organisation, on-the-job training was a good decision but the way it was carried out was not at all progressive to them or the organisation. Continuous changing the roles was not beneficial for them as they could not adjust and fully understand any role or position. Since Lisa had TAFE training, she had a better understanding of the organisation’s processes which allowed her to excel in on-the-job training making it the best training and development option for her. On-the-job training as argued by Nankervis et al. (2011) develops practical work experiences and helps in building relations with the peers if the employee is a new entrant. In case of Kane, he did not possess any TAFE qualifications and worked in large company did not have any experience in working with a small family oriented company. Off-the-job training would have been a better option for him, which could have consisted of e-learning, simulation training or conference or classroom training (Nankervis et al. 2011). On-the-job training created confusion for him causing the peers to provide negative comments on his performance. What are the advantages and disadvantages of peer evaluation, and why would Natural Knibbles choose this approach as part of its performance management process? The performance management process needs to begin by taking in to consideration the strategic plan of organisation and penetrate every level of organisation to reach every employee (Nankervis et al. 2011). One such performance management process is peer evaluation. Peer evaluation has many advantages foremost being that the peers can relate well with the employee who is being evaluated. Peers, because work together, have the ability to evaluate the person whether he/she is doing well in the activity as others. Peers reviews can improve the quality of the work and performance of the employees as they can learn from each other. Because of the peer evaluation, company can also improve the performance management process if it seems that this performance measure is not providing a complete evaluation of the employee’

Euthanasia Research Paper Example | Topics and Well Written Essays - 500 words

Euthanasia - Research Paper Example From one perspective many people believe vehemently in only one side of the argument or the other. According to an article written by the Telegraph (2010) it is the case that the BBC has been accused of ‘promoting’ euthanasia insofar as the organization highlighted Sir Terry Pratchett’s speech regarding assisted suicide by using dramatic effects and allegedly ignored the rights of disabled individuals. Although these allegations have not resulted in any significant legal action it the article did indicate that at least in the British context a poll indicated that people’s opinions are split evenly on the matter. On the second section of this paper some examples of how this issue can be complicated will be highlighted. For example, Butler (2010) writing for the New York Times indicated that decisions made earlier in the care. The article made reference to the father of the author suffering a serious stroke at the age of 79. After developing a serious and pai nful heart condition the individual had a pacemaker installed because of a desire of his wife to see her husband relieved of his pain. Fast forward five years the father is bedridden with dementia and is kept alive only with the aide of a pacemaker that is expected to last another five years.

Racism in Canada Essay Example for Free

Racism in Canada Essay Canada is known around the world as an international peacekeeper, a place of liberty, and a loving country that accepts everyone. This reputation is part of our image, and is honoured by many nations. But Canada is not perfect. Racism still exists, sometimes it maybe in the shadows, it does not take a investigative detective to notice the visible racism all around us. In some cases it is social phrases, in some it may be serious bullying, discrimination or even assault, racism is still a problem. Like the United States of America, Canada has a history with racism. In the 1900s to 1950s, there was discrimination against African-Canadians. From the time of settlement into North America, up until a few decades ago, there was serious mis-treatment of First Nation peoples, including genocide, sexual assault and child abuse. Also during WW2, Japanese-Canadians were looked upon as enemies, and treated poorly. Compared to the past, we are much more liberal, and have less racial prejudices. The improvement of civil liberties from the past to now is amazing. But still not enough. Every time I see something racist, it deeply saddens me. In my heart, Canada as a whole has left racism behind, but some people still carry the disgusting tradition. I once saw a bus driver speaking disrespectfully to an older Chinese woman, about how he couldnt understand her, and she should try to speak in English. I thought to my self how sad it is that an official city worker can be so intolerant of other cultures. I do not like racism, and see it a lot. I see racism when a group of African-Canadians attack a Caucasian man for coming to the wrong neighbourhood. I see racism when people say, White people cannot play cricket, when some of the best cricket players are Caucasian, like Alastair Cook, with over 8000 runs  scored. I see racism in stereotypes. It is clear that racism is a part of our society now, but we need to improve our selves and eradicate it for good. To abolish racism completely, we first need to put personal feelings aside, and agree on facts. Yes, we are all humans. But we need to accept our differences, we are not the exact same. Specific genotype gives athletes like Bolt a boost, dailymail reports scientific research done by University of Szczecin in Poland. Once we separate fact from fiction, we can live without delusion. Secondly, we must call out racism when ever we see it, for example if a bus driver does something wrong, he should be confronted, to avoid it from happening again. If we call out all racism when we see it, we can put an end to it. In conclusion Canada is one of the best countries to live in in the world. It is a leader in civil rights, peacekeeping, and equality. However some racism remains in our community from the past, which should be cleaned up. If we all aim towards a better future, the present could looked upon in future similarly to how the bloody 50s are seen today.

The Structure-Agency Debate

The Structure-Agency Debate I have been involved in football for as long as I can remember, with the application of Structural Functionalism I am going to attempt to understand my involvement in football. The Structure theory, Structural Functionalism can be applied to my position as a footballer and explain how football has affected my position in contemporary society. The main assumption of Structural Functionalism is that society is an organized system of interrelated parts that attempts to maintain a state of equilibrium (Williams Kolkka 1998 p.358). Williams Kolkka (1998) applied this assumption of Structural Functionalism within their research of Wheelchair Basketball, they conceptualised the activity as its own social system which comprised of its members (including players, coaches physiotherapists, supporters etc.) and the relationship between them. This can be applied to my position within football particularly at club level. I was a player at Wakefield Ladies F.C. therefore through interaction with other players and other forms of members including the coaches, physiotherapists and supporters, this lead to the maintaining the clubs state of equilibrium and the system working as a whole (Malcolm 2008). This highlights my contribution in maintaining a successful working system however Structural Functionalism only offers a positive view of sporting systems and experiences therefore offers no insight into how specific barriers and constraints challenged my position in football. Bourdieus theory deals with constraints through defining how different forms of Capital can affect a persons identity. Another aspect of Structural Functionalism is that, sport is seen as a vital tool in successfully maintaining the state of equilibrium, it is said to instil desired values and attitudes (Williams and Kolkka 1998; Malcolm 2008). Therefore a Structural Functionalist would argue that by playing football I learned the desired values and attitudes such as conformity to rules, respect and self-control which would contribute to maintaining a state of equilibrium. However, Structural Functionalism only takes into account the structure of society and not individual agency therefore provides no explanation in understanding how human beings make important decisions, such those which lead to me choosing to play football or how my current social world was created unlike Bourdieus Habitus and Capital which explains how class habitus confined me to the choice of football (Malcolm 2008; Williams 1994; Best 2003). In 2008 the FA rolled out the RESPECT campaign across all levels of football, in respon se to a range of behavioural problems surrounding the game. The campaign was designed to protect players and referees and create an environment in which sport can be enjoyed but also have wider benefits to society. I played under the RESPECT campaign when it was first introduced and on reflection, I found it reinforced the desired values and attitudes which are required not only on the football pitch but also in wider society (RESPECT: Four Years On. 2012; Malcolm 2008). A Structural Functionalist would view the RESPECT campaign as a positive step to creating a state of equilibrium (Williams Kolkka 1998). It is evident that Structural Functionalism highlights how I have been a part of maintaining a successful societal system and also the positive effect in which sport has had on my life however it offers no reasoning as to why I became involved in football. . The Agency theory, Symbolic Interactionism can be applied in attempt to gain an understanding of my involvement within football. George Herbert Mead is said to be the founding Father of Symbolic Interactionism. Hewitt (2000 in Armstrong 2007) defines Symbolic Interactionism as a theory which helps human beings define and give meaning to experiences, allowing them to create an individual and unique identity. The main assumption of Symbolic Interactionism is that society is created and maintained by social interaction: we are all actors on a stage who generate meaning through what we do and who we do it with (Craig Beedie 2010 p.61). This draws upon my decision to join a football club; it allowed social interaction to occur which consequently constructed my own social world. Malcolm (2008) furthers Craig and Beedies (2010) assumption by highlighting the focus upon the individual and the way in which they interpret and make sense of the world in which they live in. There are two widely researched areas within Symbolic Interactionism, Socialisation and Subcultures. Firstly, Socialisation focusses upon who becomes involved in sport and is developed through learning to read, understand and interpret symbols to aid individuals in becoming members of society (Best 2003). Cottingham (2012) states how interpreting symbols in the correct manner is a fundamental process, as it increases focus and wider understanding of an object, Gilbert (1994) furthers Cottinghams (2012) statement by adding, that the constructs are grounded within the minds of those who experience the perceived symbolic actions (p. 142). On reflection, throughout the years I have understood and interpreted symbols whilst playing football to aid my socialisation. For example when I first began to attend training sessions at Wakefield Ladies F.C, by interpreting and understanding the coaches I was able to demonstrate competence which led to being selected on a match day and also accepted by the rest of the team on a social level due to my ability to prescribe to the groups norm. It could be argued that my behaviour at Wakefield F.C. Ladies was due to previous experiences; specific symbols became grounded in my mind throughout my development from junior level to the open age therefore this would have led to improving my process of socialisation throughout the years (Best 2003; Gilbert 1994). This example can also be related to the second research area within the Agency debate, Subcultures. By prescribing to the groups norms in terms of beliefs and practices I was accepted and became part of a socially defined group, further creating myself a specific identity (Craig Beedie 2010). I confirmed this identity through not only Symbolic Interactionism but also symbolic consumption as I have specific Wakefield F.C. Ladies clothing which I am required to wear for training, matches and other events, these items of clothing have a specific meaning of being a part of the team therefore is an effective tool in creating my identity (Armstrong 2007). It is clear that by applying Symbolic Interactionism to my own position within contemporary society I can begin to understand why events occurred and why I was accepted into the team. However Symbolic Interactionism is often criticised for over emphasising individual agency and failing to take into account structural inequalities and constraints such as race, gender, class and ethnicity (Craig Beedie 2010). On reflection, this weakness can be applied to my example as, playing for Wakefield F.C; the mens section of club was deemed superior and was seen in a much more favourable perspective to the Womens section. This was a constraint which we had to regularly deal with and included reduced funding compared to the mens section and poor training facilities. Therefore we had a barrier to overcome whilst attempting to build a successful team. This weakness highlights how Agency theories do not take into account power systems as a Post-Dualist theory would. Bourdieu would argue that this barrier would not create a working system and would affect my interpretation of experiences, as any experiences related to this constraint are likely to be deemed negative (Best 2003). It could be argued that the Agency theory, Symbolic Interactionism helps explain my interpretation of my own social construct but still with some constraints. A third theory which can be drawn upon is the post-dualist theory, Bourdieus Habitus and Capital, which takes into account both structures in society and individual agency (Craig Beedie 2010). Bourdieus work was based upon empirical and theoretical investigations; his work was also in relation to sport, unlike Structural Functionalism and Symbolic Interactionism. They are theories that were not originally based around sport but were later applied and adapted to help offer a sociological explanation of sport. Bourdieu developed a social framework from his empirical and theoretical investigations which involved Habitus, Capital and Field; I will use Habitus and Capital in attempt to explain my involvement with football. Firstly, Capital can be defined as power and Habitus is defined by Elliott (2009) as a structuring feature with an infinite capacity for moulding individuals. Habitus is internalised as a second nature, as individuals we acquire habits, either knowingly or unknowingly, from a structural context and we use these practices to live out our everyday lives (Best 2003 p.204). Bourdieus work links class habitus and taste extremely closely; this can be applied to my position within society as it could be argued that both class habitus and taste led to my choice of football. It is clear that the subconscious decision to develop an interest in football is due to my class habitus and the confinement of my families working class background (Best 2003). The sport of football reflects class distinctions and represents the class I belong to; if I was born into an upper class family I may have developed an interest in other sports such as Rugby Union or Polo (Best 2003; Tomlinson 2004). Furthermore, my Fathers taste and class habitus will have affected my subconscious decision, as he had already developed specific practices; including supporting and playing football therefore this would have influenced the practices I developed whilst growing up (Best 2003). Bes t (2003) argues that despite us developing different practices to make a distinction between ourselves and others, people who live within the same social field are likely to share the same habitus, therefore people who I were brought up around all had a specific interest in football which is another reason why I may have been inclined towards football. Finally, it can be argued that Bourdieus class habitus can be applied best to explain my interest in football as it focusses upon where my interest originates from unlike the other Structural Functionalism and Symbolic Interaction. Another aspect of Bourdieus work which can be applied to my position within football is his work involving the body and the creation and reproduction of social differences that can be displayed by the body, one way it can be displayed is through accent (Craig Beedie 2010). A strong Yorkshire accent is often related to the working class therefore this is a form of cultural capital in the embodied state (Laberge 1995). Social differences in terms of cultural capital can be identified when I play football for University because part of my cultural capital is a Yorkshire accent therefore this is not the norm within the University team, as the majority of players are from the Middlesbrough area (Craig and Beedie 2010; Laberge 1995). This differs from when I played football for Wakefield F.C. Ladies, as the majority of players were from the same area therefore shared the same accent. This highlights a difference in individual agency and also the importance of cultural capital. Bourdieus w ork has been criticised over the years, Elliott (2009) argues that Bourdieus work takes the economy for granted and does not take into account the role of economic issues upon social life, Elliott (2009) furthers his argument by accusing Bourdieu of elevating cultural capital over economic capital. This can clearly be seen as despite Bourdieus work leading me to define how I came to develop an interest in football, however it has not taken into account the economic constraints which I faced such as cost of travel, kit and also subs after each match. It is evident that this is an economic force which was a barrier to me. In terms of my example economic capital is much more significant than Cultural Capital, economic capital was a barrier where as cultural capital just highlights a difference between team members. In conclusion, it is evident that all three theories can be applied to my position within contemporary society however after taking into consideration their strengths and weaknesses along with application, I believe Bourdieus post-dualist theory applies best as it takes into consideration the structures within society but also the agency of the individual (Craig Beedie 2010). Bourdieus Habitus and Capital allows an explanation of the origins of my interest in sport, Symbolic Interactionism and Structural Functionalism cannot do this. They only offer significant explanations of what sport has offered me and how it has contributed to the identity in which I hold today. Therefore it is clear that Bourdieus work is the most complex and offers a better understanding of my interest in sport and my position within contemporary society.

Additive Manufacturing of Medical Implants: A Review

Additive Manufacturing of Medical Implants: A Review E. Gordon Wayne State University College of Engineering Abstract Additive manufacturing has numerous applications and is gaining interest in the biomedical field. The quality of additively manufactured parts is constantly improving, which contributes to their increased use for medical implants in patients. This paper reviews the literature on surgical additive manufacturing applications used on patients, with a focus on the customization of 3D printed implants and the ability to incorporate scaffolds on the implant surface. Scholarly literature databases were used to find general information on the focus topics, as well as case studies of surgical applications of additive manufacturing implants in rodents and humans. The advantages of additive manufacturing medical implants include improved medical outcome, cost effectiveness, and reduced surgery time, as well as customization and incorporated scaffold. Overall, the most effective type of additive manufacturing for the medical implant application is electron beam melting using Ti-6Al-4V because it can produce a high quality, high purity biocompatible implant that has the required mechanical properties. Keywords: Additive Manufacturing, Customized implants, Scaffold, 3D Printing, Ti-6Al-4V Introduction In recent years, additive manufacturing technologies have improved significantly, thus expanding the fields and applications for which they can be used. These 3D printing technologies create physical models from digital models without the need for tool and die and process planning. Additive manufacturing can fabricate prototypes of complex shapes in a variety of materials such as metals, polymers, and nylon. Metal components, in particular, can be used for practical applications such as medical implants: devices manufactured to replace or support a biological structure. The biocompatibility of these metallic devices must be considered, creating rigorous requirements for the material selection and final material properties of the structure. Studies have shown that additive manufacturing successfully produces implants with biocompatible materials that meet the structural requirements [1-6]. 3D printing medical implants can provide many benefits such as the customization and personalization of the implants, cost-effectiveness, increased productivity, and the ability to incorporate scaffold. Using custom made implants, fixtures and surgical tools can help decrease surgery time and patient recovery time, while increasing the likelihood of a successful surgery [7]. Another benefit is the cost efficiency of 3D printing medial implants. Traditional manufacturing methods are cheaper for large quantities, but are more expensive for personalized designs and small production runs [8, 9]. 3D printing is especially cost effective for small-sized implants like spinal or dental implants. 3D printing is also faster than traditional manufacturing if a custom implant needs to be made; traditional methods require milling, forging, and a long delivery time while 3D printing may only take about a day [1]. Another notable benefit of additive manufacturing is the ability to share data files of designs. Files saved as an .STL can be downloaded and printed anywhere in the world. The National Institutes of Health established a 3D Print Exchange to promote open-source sharing of 3D print files for medical models [7]. The most significant benefits for the biomedical industry, however, are the ability to manufacture biocompatible materials, customize implants, and incorporate a porous scaffold surface. Types of Additive Manufacturing The additive manufacturing approach uses computer software to slice a complex 3D model into layers of 2D cross-sections with a minute thickness. The layers are then printed layer by layer depending on the particular method chosen for the application. There are dozens of types of additive manufacturing systems on the market, some of the most common being stereolithography (SLA), direct metal laser sintering (DMLS), selective laser sintering (SLS), selective laser melting (SLM), 3D printing (3DP), and electron beam melting (EBM). These systems are classified according to the form of the raw material, which can be powder, liquid, or solid form [8]. The two types of additive manufacturing that are most commonly used for medical implants are SLS and EBM. Figure 1: Process chain for SLM and EBM. The pre-processing before manufacturing includes 3D modeling, file preparation, and slicing of the 3D model into layers. Post-processing may include heat treatment and polishing of fabricated parts [10]. Selective Laser Sintering An SLS printer uses a powder form of material for printing objects. A laser fuses a single layer of powder by drawing the shape of the object according to the first 2D cross-section of the 3D model. Immediately, the build platform is lowered by the defined layer thickness and another layer of powder is rolled across [10]. The process repeats, fusing each layer one at a time to form the object. SLS can be used with metal, ceramic, and plastic powders. The precision of the laser and the diameter of the powder determines the degree of detail of the final object, so it is possible to create detailed structures with an SLS printer [11]. Figure 2: Schematic of SLS system. The key components of SLM include the laser system (a fiber laser, F-theta and galvanometer used to control the laser beam movement) and the mechanical system (movable build platform and powder roller) [10]. Electron Beam Melting An EBM printer uses a powder form of material for printing objects, similar to SLS. However, while SLS uses a laser to fuse each layer of the powder, EBM uses an electron beam. This energy is delivered through an electric circuit between a tungsten filament inside of the electron gun and the build platform [10]. An electric current heats the filament to emit a beam of electrons [1]. Electric energy is transformed to heat energy which melts the powder on the build platform. The process continues similarly to SLS, where powder is spread across the platform in a thin layer, the cross-section of the object is melted, and then the build platform lowers by the layer thickness. A key element of EBM is that the build chamber is kept under vacuum, which allows the object to be maintain great detail (70-100ÃŽÂ ¼m) [1]. Figure 3: Schematic of EBM system. The key components of EBM include an electron beam system (electron gun assembly, electron beam focusing lens and deflection coils used to control the electron beam) and the mechanical system (movable powder rake and fixed powder cassettes) [10]. Materials of Medical Implants The most common metals used for surgical implants are stainless steel 316L (ASTM F138), Cobalt based alloys (ASTM F75 and ASTM F799) and titanium alloy Ti-6Al-4V (ASTM F67 and F136) [12, 13]. However, these metals have disadvantages such as the potential release of toxic ions and particles due to corrosion that cause inflammation and allergic reactions, affecting biocompatibility [14]. Also, the materials that have an elastic modulus that is not similar to natural bone stimulate new bone growth poorly [12]. Despite this, the low Youngs modulus, high strength, and nonlinear elasticity of titanium-based alloys make it the least harmful choice [3]. The most commonly used titanium alloy is Ti-6Al-4V (Ti64) because it also has a better resistance to corrosion compared to stainless steels and cobalt-based alloys [15]. Additive manufacturing has also been done using Tantalum. Tantalum is biocompatible, hard, ductile, and chemically resistant, but it is expensive and difficult to machine [6] . Titanium based alloys are superior, thus Ti-6Al-V4 is the best material for additive manufacturing medical implants. Material Youngs modulus (GPa) Ultimate tensile strength (MPa) Yield strength (MPa) Elongation (%) TiTa 75.77  ± 4.04 924.64  ± 9.06 882.77  ± 19.60 11.72  ± 1.13 Ti6Al4V 131.51  ± 16.40 1165.69  ± 107.25 1055.59  ± 63.63 6.10  ± 2.57 cpTi 111.59  ± 2.65 703.05  ± 16.22 619.57  ± 20.25 5.19  ± 0.32 Table 1: Tensile properties of SLS produced TiTa, Ti6Al4V and commercially pure titanium samples (n = 5) [16]. Customized Implants Additive manufacturing allows for the design and fabrication of customized prosthetic implants that are created to meet the specific needs of a patient, such as the size, shape, and mechanical properties of the implant. Additive Manufacturing reduces design time as well as manufacturing time because the implant pattern is computer generated with CT and MRI scans, thus removing the need for a physical model [8]. The ability to produce custom implants quickly solves a common problem with orthopedics where standard implants do not always fit the needs of certain patients. Previously, surgeons had to manually modify implants to make them fit the patient [7]. These techniques can be used by professionals in a variety of specialties such as neurosurgery, orthopedics, craniofacial and plastic surgery, oncology, and implant dentistry [8]. One example of an application in which a customized implant is required is craniofacial reconstruction. Craniofacial abnormalities are a diverse group of congenital defects that affect a large number of people and can be acquired at birth or due to injuries or tumors [8]. Standard cranial implants rarely fit a patient precisely because skulls have irregular shapes [7]. The custom implant can be created by using a CT scan to create a 3D virtual model of the patients skull. Then the model can be used with CAD software to design an implant that would perfectly fit the patient [8]. Using custom implants has shown to improve the morphology for large and complex-shaped cranial abnormalities, and some researchers have observed a greater improvement in neurological functions than after similar surgeries using traditionally manufactured implants [17, 18]. Figure 4: Skull model and customized implant for craniofacial reconstruction surgery [8]. Scaffold Additive manufacturing medical implants allows the porosity of the surface to be designed, controlled, and interconnected, which provides better bone growth into implants, thus decreasing the chances of the body rejecting the implant. Additionally, the rough surface quality of 3D printed implants enhances bone-implant fixation [1]. Without scaffold, there is a risk of bone weakening and bone loss around the implant, which is a consequence of stress shielding due to high stiffness of materials [19]. The probability of this problem occurring is lessened when bone can grow into a porous surface of the implant [19]. Cellular lattice structures are classified by stochastic and non-stochastic geometries. The pores in stochastic structures have random variations in size and shape, while the pores in non-stochastic structures have repeating patterns of particular shapes and sizes [10]. The main challenge in additively manufacturing scaffolds is the difficulty to remove the loose powder from within the pores, but an advantage is that additive manufacturing technology allows for the manufacturing of different types of scaffolds if a design requires it; different regions of the implant could have different porosities [1, 10]. The procedure used to achieve the porous areas with traditional manufacturing methods includes coating a smooth surface with other materials such as plasma-sprayed titanium or a titanium wire mesh; however, combining different metals increases the risk of the body rejecting the implant. Additive manufacturing allows the smooth and porous surfaces to be fabricated with the same material, thus decreasing that risk. A variety of additive manufacturing techniques can be used to create the lattice structure, but scaffold can be fabricated by SLS or EBM without the need for support structures, thus making it the most effective method [5]. Figure 5: Acetabular cup with designedFigure 6: (a) Porous femoral stem on the building porous surface [10].platform, (b) post-processed femoral stem [5]. Conclusion There are many advantages to using additive manufacturing to fabricate surgical implants. These benefits include improved medical outcome, cost effectiveness, reduced surgery time, as well as customization and scaffold. Overall, the most effective type of additive manufacturing for the medical implant application is Electron Beam Melting because it can produce a high quality, high purity biocompatible implant that has the required mechanical properties. The recommended metal to use for most implants is the titanium-based alloy Ti-6Al-4V because of its low Youngs modulus, high strength, nonlinear elasticity, and corrosion resistance. Overall, additive manufacturing is an excellent production method for medical implants because it allows surgeons to customize implants and scaffold to the specific needs of the patient. References 1.Petrovic, V., et al., Additive manufacturing solutions for improved medical implants. 2012: INTECH Open Access Publisher. 2.Ahn, Y.K., et al., Mechanical and microstructural characteristics of commercial purity titanium implants fabricated by electron-beam additive manufacturing. Materials Letters, 2017. 187: p. 64-67. 3.Yan, L.M., et al., Improved mechanical properties of the new Ti-15Ta-xZr alloys fabricated by selective laser melting for biomedical application. Journal of Alloys and Compounds, 2016. 688: p. 156-162. 4.Caldarise, S., Hip joint prostheses and methods for manufacturing the same. 1996, Google Patents. 5.Simoneau, C., et al., Development of a porous metallic femoral stem: Design, manufacturing, simulation and mechanical testing. Materials Design, 2017. 114: p. 546-556. 6.Wauthle, R., et al., Additively manufactured porous tantalum implants. Acta Biomaterialia, 2015. 14: p. 217-225. 7.Ventola, C.L., Medical Applications for 3D Printing: Current and Projected Uses. Pharmacy and Therapeutics, 2014. 39(10): p. 704-711. 8.Jardini, A.L., et al., Cranial reconstruction: 3D biomodel and custom-built implant created using additive manufacturing. Journal of Cranio-Maxillofacial Surgery, 2014. 42(8): p. 1877-1884. 9.DUrso, P.S., et al., Custom cranioplasty using stereolithography and acrylic. British Journal of Plastic Surgery, 2000. 53(3): p. 200-204. 10.Sing, S.L., et al., Laser and electronà ¢Ã¢â€š ¬Ã‚ beam powderà ¢Ã¢â€š ¬Ã‚ bed additive manufacturing of metallic implants: A review on processes, materials and designs. Journal of Orthopaedic Research, 2016. 34(3): p. 369-385. 11.Hoy, M.B., 3D printing: making things at the library. Med Ref Serv Q, 2013. 32(1): p. 94-9. 12.Kokubo, T., et al., Bioactive metals: preparation and properties. J Mater Sci Mater Med, 2004. 15(2): p. 99-107. 13.Staiger, M.P., et al., Magnesium and its alloys as orthopedic biomaterials: A review. Biomaterials, 2006. 27(9): p. 1728-1734. 14.Polo-Corrales, L., M. Latorre-Esteves, and J.E. Ramirez-Vick, Scaffold Design for Bone Regeneration. Journal of nanoscience and nanotechnology, 2014. 14(1): p. 15-56. 15.Dinda, G.P., L. Song, and J. Mazumder, Fabrication of Ti-6Al-4V Scaffolds by Direct Metal Deposition. Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, 2008. 39A(12): p. 2914-2922. 16.Sing, S.L., W.Y. Yeong, and F.E. Wiria, Selective laser melting of titanium alloy with 50 wt% tantalum: Microstructure and mechanical properties. Journal of Alloys and Compounds, 2016. 660: p. 461-470. 17.Rotaru, H., et al., Cranioplasty With Custom-Made Implants: Analyzing the Cases of 10 Patients. Journal of Oral and Maxillofacial Surgery, 2012. 70(2): p. e169-e176. 18.Agner, C., M. Dujovny, and M. Gaviria, Neurocognitive Assessment Before and after Cranioplasty. Acta Neurochirurgica, 2002. 144(10): p. 1033-1040. 19.Shah, F.A., et al., Long-term osseointegration of 3D printed CoCr constructs with an interconnected open-pore architecture prepared by electron beam melting. Acta Biomaterialia, 2016. 36: p. 296-309. Bacillus Thuringiensis: Distribution and Habitat Bacillus Thuringiensis: Distribution and Habitat LITERATURE REVIEW For several decades since its discovery, formulations of Bacillus thuringiensis (B. t.) have been seen as the ideal means of controlling Lepidoteran pests in agriculture because of the many attributes that differentiate this microbial insecticide from the synthetic chemical formulations. No toxicity to mammals, environmental friendliness, apparent immunity to the pesticide resistance phenomenon (no longer true), good integration with other pest control methods and the possibility of being mass produced at farm level at low cost, all made B. thuringiensis the much-needed tool for IPM programmes in developing countries. Research of almost 85 years reveals that Bacillus spp., especially B. thuringiensis and Bacillus sphaericus are the most potent biopesticides (Boucias Pendland, 1998). B. thuringiensis is a species of bacteria that has insecticidal properties that affects a specific range of insect orders. There are at least 34 subspecies of  B. thuringiensis (also called serotypes o r varieties) and possibly over 800 strain isolates (Swadener, 1994). B. thuringiensis accounts for about 5-8% of Bacillus spp. population in the environment (Hastowo et al., 1992). Till date more than 130 species of lepidopteran, dipteran and coleopteran insects are found to be controlled by  B. thuringiensis (Dean, 1984). Historical Background of B. thuringiensis B. thuringiensis are interesting and important bacteria used in the biological control of insect pest which form toxic crystal proteins at the time of sporulation. Perhaps the most well known and widely used biopesticide comes from B. thuringiensis, a bacterium that produces insecticidal proteins during its sporulation. This common soil bacterium, most abundantly found in grain dust from soil and other grain storage facilities, was discovered first in Japan in 1901 by Ishawata and then in 1911 in Germany by Berliner (Baum et al., 1999). It was subsequently found that thousands of strains of B. thuringiensis exist (Lereclus, 1993). The bacterium was isolated from diseased larvae of Anagasta kuehniella, and this finding led to the establishment of B. thuringiensis as microbial insecticide. The first record of its application to control insects was in Hungary at the end of 1920, and in Yugoslavia at the beginning of 1930s, it was applied to control the European corn borer (Lords, 2005). Sporine which was the first commercial product of B. thuringiensis was available in 1938 in France (Waiser, 1986) for the control of flour moth (Jacobs, 1951). Unfortunately, the product was used only for a very short time, due to World War II (Nester et al., 2002). Formation of transgenic plant was also observed. The first reports of insertion of genes encoding for B. thuringiensis delta-endotoxins into plants came in 1987 and the first transgenic plants to express B. thuringiensis toxins were tobacco and tomato plants (van Frankenhuyzen, 1993). In 1957 pacific yeast products commercialized the first strain on B. thuringiensis, named as Thuricide due to the increasing concern of biopesticide over the use of chemical insecticides. B. thuringiensis is a gram-positive spore-forming bacterium that produces crystalline proteins called deltaendotoxins during its stationary phase of growth (Schnepf et al., 1998). The crystal is released to the environment after analysis of the cell wall at the end of sporulation, and it can account for 20 to 30% of the dry weight of the sporulated cells (Schnepf et al., 1998) Distribution Habitat of B. thuringiensis This bacterium is distributed worldwide (Martin Travers, 1989). The soil has been described as its main habitat; however it has also been isolated from foliage, water, storage grains, and dead insects, etc (Iriarte Caballero, 2001). Isolation of strains from dead insects has been the main source for commercially used varieties, which include kurstaki, isolated from A. kuehniella; israelensis, isolated from mosquitoes, and tenebrionis, isolated from Tenebrio monitor larvae (Ninfa Rosas, 2009; Iriarte Caballero, 2001).. The spores of B. thuringiensis persist in soil, and vegetative growth occurs when nutrients are available (DeLucca et al., 1981; Akiba, 1986; Ohba Aizawa, 1986; Travers et al., 1987; Martin Travers, 1989). DeLucca et al., (1981) found that B. thuringiensis represented between 0.5% and 0.005% of all Bacillus species isolated from soil samples in the USA. Martin Travers (1989) recovered B. thuringiensis from soils globally. Meadows (1993) isolated B. thuringiensis from 785 of 1115 soil samples, and the percentage of samples that contained  B. thuringiensis ranged from 56% in New Zealand to 94% in samples from Asia and central and southern Africa. Ohba Aizawa (1986) isolated B. thuringiensis from 136 out of 189 soil samples in Japan. There are several theories on the ecological niche filled by B. thuringiensis. Unlike most insect pathogenic microbes, B. thuringiensis generally recycle poorly and rarely cause natural epizootics in insects, leading to speculation that B. thuringiensis is essentially a soil micro-organism that possesses incidental insecticidal activity (Martin Travers 1989). Evidence to support this view is that B. thuringiensis are commonly reported in the environment independent of insects and there is a lack of association between occurrence and insect activity (van Frankenhuyzen 1993). Meadows (1993) suggested four possible explanations for the presence of B. thuringiensis in soil: 1) rarely grows in soil but is deposited there by insects; 2) may be infective to soil-dwelling insects (as yet undiscovered); 3) may grow in soil when nutrients are available; and 4) an affinity with B. cereus. B. thuringiensis has been found extensively in the phylloplane. Numerous  B. thuringiensis subspecies have been recovered from coniferous trees, deciduous trees and vegetables, as well as from other herbs (Smith Couche, 1991; Damgaard et al., 1997). B. thuringiensis deposited on the upper side of leaves (exposed to the sun) may remain effective for only 1-2 days, but B. thuringiensis on the underside of leaves (i.e. protected from the sun) may remain active for 7-10 days (Swadner, 1994). B. thuringiensis kurstaki has been recovered from rivers and public water distribution systems after an aerial application of Thuricide 16B (Ohana, 1987). Crystal Composition and Morphology The existence of parasporal inclusions in B. thuringiensis was first noted in 1915 (Berliner, 1915), but their protein composition was not delineated until the 1950s (Angus, 1954). Hannay (1953) detected the crystalline fine structure that is a property of most of the parasporal inclusions. B. thuringiensis subspecies can synthesize more than one inclusion, which may contain different ICPs (Hannay, 1953). Depending on their ICP composition, the crystals have various forms (bipyramidal, cuboidal, flat rhomboid, or a composite with two or more crystal types) (Bulla et al., 1977; Hà ¶fte Whiteley, 1989). A partial correlation between crystal morphology, ICP composition, and bioactivity against target insects has been established (Bulla et al., 1977; Hà ¶fte Whiteley, 1989; Lynch Baumann, 1985). Classification of B. thuringiensis subspecies The classification of B. thuringiensis subspecies based on the serological analysis of the flagella (H) antigens was introduced in the early 1960s (de Barjac Bonnefoi, 1962). This classification by serotype has been supplemented by morphological and biochemical criteria (de Barjac, 1981). Until 1977, only 13 B. thuringiensis subspecies had been described, and at that time all subspecies were toxic to Lepidopteran larvae only. The discovery of other subspecies toxic to Diptera (Goldberg Margalit, 1977) and Coleoptera (Krieg et al., 1983) enlarged the host range and markedly increased the number of subspecies. Up to the end of 1998, over 67 subspecies based on flagellar H-serovars had been identified. Genetics of ICP In the early 1980s, it was established that most genes coding for the ICPs reside on large transmissible plasmids, of which most are readily exchanged between strains by conjugation (Gonzà ¡lez Carlton, 1980; Gonzà ¡lez et al., 1981). Since these initial studies, numerous ICP genes have been cloned, sequenced and used to construct  B. thuringiensis strains with novel insecticidal spectra (Hà ¶fte Whiteley, 1989). The currently known crystal (cry) gene types encode ICPs that are specific to either Lepidoptera (cryI), Diptera and Lepidoptera (cryII), Coleoptera (cryIII), Diptera (cryIV), or Coleoptera and Lepidoptera (cryV) (Hà ¶fte Whiteley, 1989). All ICPs described to date attack the insect gut upon ingestion. To date, each of the proteolytically activated ICP molecules with insecticidal activity has a variable C-terminal domain, which is responsible for receptrecognition (host susceptibility), and a conserved  N-terminal domain, which induces pore formation (toxicity) (Li et al., 1991). Most naturally occurring B. thuringiensis strains contain ICPs active against a single order of insects. However, conjugative transfer between B. thuringiensis strains or related species can occur, resulting in new strains with various plasmid contents (Gonzà ¡lez Carlton, 1980). Thus the mobility of the cry genes and the exchange of plasmids may explain the diverse and complex activity spectra observed in B. thuringiensis (Gonzà ¡lez Carlton, 1980; Gonzà ¡lez et al., 1981; Gonzà ¡lez et al., 1982; Reddy et al., 1987; Jarrett Stephenson, 1990). New B. thuringiensis strains have been developed by conjugation that is toxic to two insect orders. Nutritional status of B. thuringiensis Since sporulation and germination in bacilli are dependent on the nutritional status of the organism (Hardwick Foster, 1952), a study of the nutritional requirement of  B. thuringiensis var. thuringiensis is important for delineating the control mechanisms which regulate spore and parasporal crystal formation. Certain amino acids support growth, sporulation and crystal formation of B. thuringiensis var. thuringiensis, while others inhibit the growth (Singer et al., 1966; Singer Rogoff, 1968; Bulla et al., 1975; Nickerson Bulla, 1975; Rajalakshmi Shethna, 1977). A lower concentration of cystine (Nickerson Bulla, 1975) or cysteine (Rajalakshmi Shethna, 1977) promotes growth, sporulation and crystal formation in Î’. thuringiensis, while at a higher concentration of cys/cysSH, only the vegetative growth was observed, (Rajalakshmi Shethna, 1977). Classification of B. thuringiensis The classification of B. thuringiensis subspecies based on the serological analysis of the flagella (H) antigens was introduced in the early 1960s (de Barjac Bonnefoi, 1962). This classification by serotype has been supplemented by morphological and biochemical criteria (de Barjac, 1981). Many strains of B. thuringiensis have been isolated and classified within more than 20 different varieties by serological techniques. On the basis of their potency for insect these varieties have been grouped into five pathotypes: Lepidopteran-Specific (e.g. B. thuringiensis .var Kurstaki) Dipteran-Specific (e.g. B. thuringiensis . var israelensis) Coleopteran-Specific (e.g. B. thuringiensis .var. tenebrionis) Those active against Lepidoptera and Dipter(e.g. B. thuringiensis . var. aizawai) Those with no toxicity recorded in insects (e.g. B. thuringiensis . var. Dakota) Mode of Action The ICP structure and function have been reviewed in detail by Schnepf et al., (1998). Binding of the ICP to putative receptors is a major determinant of ICP specificity and the formation of pores in the midgut epithelial cells is a major mechanism of toxicity (Van Frankenhuyzen, 1993). After ingestion of B. thuringiensis by insect the crystal is dissolved in the insects alkaline gut. Then the digestive enzymes that are present in insects body break down the crystal structure and activate B. thuringiensiss insecticidal component, called the delta-endotoxin (Swadner, 1994). The delta-endotoxin binds to the cells lining the midgut membrane and creates pores in the membrane, upsetting the guts ion balance. The insect soon stops feeding and starves to death (Gill et al., 1992). Target Organisms In the past decades, B. thuringiensis Cry toxins were classified according to the target pest they attacked (Hofte Whiteley, 1998); however, due to the dual toxic activity exhibited by some cry genes and the inconsistencies in the original classification proposed by Hà ¶fte and Whiteley(1998), Crickmore et al., (1998) proposed a revision of the nomenclature for insecticidal crystal proteins, based on the ability of a crystal protein to exhibit some experimentally verifiable toxic effect in a target organism (Crickmore et al., 1998; Hà ¶fte Whiteley, 1998). The diversity of B. thuringiensis is demonstrated in the almost 70 serotypes and the 92 subspecies described to date (Galan-Wong et al., 2006). It is well known that many insects are susceptible to the toxic activity of  B. thuringiensis; among them, lepidopterans have been exceptionally well studied, and many toxins have shown activity against them (Jarret Stephens., 1990; Sefinejad et al., 2008). Order Lepidoptera encompasses the majority of susceptible species belonging to agriculturally important families such as Cossidae, Gelechiidae, Lymantriidae, Noctuidae, Pieridae, Pyralidae, Thaumetopoetidae, Tortricidae, and Yponomeutidae (Iriarte Caballero, 2001). General patterns of use: Commercial applications of B. thuringiensis have been directed mainly against lepidopteran pests of agricultural and forest crops; however, in recent years strains active against coleopteran pests have also been marketed (Tomlin, 1997). Strains of B. thuringiensis kurstaki active against dipteran vectors of parasitic disease organisms have been used in public health programmes (Tomlin, 1997). Applications in agriculture and forestry Commercial use of B. thuringiensis on agricultural and forest crops dates back nearly  30 years, when it became available in France (Van Frankenhuyzen, 1993). Use of  B. thuringiensis has increased greatly in recent years and the number of companies with a commercial interest in B. thuringiensis products has increased from four in 1980 to at least 18 (Van Frankenhuyzen, 1993). Several commercial B. thuringiensis products with B. thuringiensis aizawai, B. thuringiensis kuehniella or B. thuringiensis tenebrionise have been applied to crops using conventional spraying technology. Various formulations have been used on major crops such as cotton, maize, soybeans, potatoes, tomatoes, various crop trees and stored grains. Formulations have ranged from ultralow-volume oil to high-volume, wettable powder and aqueous suspensions (Tomlin, 1997). In the main, naturally occurring B. thuringiensis strains have been used, but transgenic microorganisms expressing B. thuringiensis toxins have been developed by conjugation and by genetic manipulation, and in some cases, these have reached the commercial market (Carlton et al., 1990). These modified organisms have been developed in order to increase host range, prolong field activity or improve delivery of toxins to target organisms. For example, the coleopteran-active cryIIIA gene has been transferred to a lepidopteran-active B. thuringiensis kuehniella (Carlton et al., 1 990). A plasmid bearing an ICP gene has been transferred from B. thuringiensis to a non-pathogenic leaf-colonizing isolate of Pseudomonas fluorescens; fixation of the transgenic cells produces ICP contained within a membrane which prolongs persistence (Gelernter, 1990). Applications in vector control B. thuringiensis Kurstaki has been used to control both mosquitos and blackflies in large-scale programmes (Lacey et al., 1982; Chilcott et al., 1983; Car, 1984; Car de Moor, 1984; Cibulsky Fusco, 1987; Becker Margalit, 1993; Bernhard Utz, 1993). For example, in Germany 23 tonnes of B. thuringiensis Kurstaki wettable powder and 19 000 litres of liquid concentrate were used to control mosquitos (Anopheles and Culex species) between 1981 and 1991 in the Upper Rhine Valley (Becker Margalit, 1993). In China, approximately 10 tonnes of B. thuringiensis Kurstaki have been used in recent years to control the malarial vector, Anopheles sinensis. Resistance of Insect Populations A number of insect populations of several different species with different levels of resistance to B. thuringiensis have been obtained by laboratory selection experiments during the last 15 years (Schnepf et al., 1998). The species include Plodia interpunctella, Cadra cautella, Leptinotarsa decemlineata, Chrysomela scripta, Tricholplusia ni, Spodoptera littoralis, Spodoptera exigua, Heliothis virescens, Ostrinia nubilalis and Culex quinquefasciatus (Schnepf et al., 1998). The Indian meal moth, a pest of grain storage areas, was the first insect to develop resistance to B. thuringiensis. Kurstaki (Swadner, 1994). Resistance progresses more quickly in laboratory experiments than under field conditions due to higher selection pressure in the laboratory (Tabashnik, 1991). No indications of insect resistance to B .thuringiensis were observed in the field, until the development of resistance was ob-served in the diamondback moth in crops where B. thuringiensis had been used repeatedly. Since then, resistance has been observed in the laboratory in the tobacco budworm, the Colorado potato beetle and other insect species (McGaughey, 1992) B. thuringiensiss Ecological Impacts Some of the most serious concerns about widespread use of B. thuringiensis as a pest control technique come from the effects it can have on animals other than the pest targeted for control. All B. thuringiensis products can kill organisms other than their intended targets. In turn, the animals that depend on these organisms for food are also impacted (Swadner, 1994). Effect on Beneficial insects: Many insects are not pests, and any pest management technique needs to be especially concerned about those that are called beneficials, the insects that feed or prey on pest species (Swadner, 1994). B. thuringiensis has impacts on a number of beneficial species. For example, studies of a wasp that is a parasite of the meal moth (Plodia interpunctella) found that treatment with B. thuringiensis reduced the number of eggs produced by the parasitic wasp, and the percentage of those eggs that hatched (Salama, 1993). Production and hatchability of eggs of a predatory bug were also decreased (Salama, 1991). Other insects: Many insects that do not have as directly beneficial importance to agriculture are important in the function and structure of ecosystems. A variety of studies have shown that B. thuringiensis applications can disturb insect communities (Swadner, 1994). Research following large-scale B. thuringiensis applications to kill gypsy moth larvae in Lane County, Oregon, found that the number of oak-feeding caterpillar species was reduced for three years following spraying, and the number of caterpillars was reduced for two years (Miller, 1990). Birds: Because many birds feed on the caterpillars and other insects affected by B. thuringiensis applications, it is not surprising that impacts of B. thuringiensis spraying on birds have been documented (Swadner, 1994). In New Hampshire, when B. thuringiensis-treatment reduced caterpillar abundance, black-throated blue warblers made fewer nesting attempts and also brought fewer caterpillars to their nestlings (Rodenhouse, 1992). Effects on Humans Eight human volunteers ingested 1 gram of a B. thuringiensis kuehniella formulation  (3 ÃÆ'- 109 spores/g of powder) daily for 5 days. Of the eight volunteers, five also inhaled 100 mg of the B. thuringiensis kuehniella powder daily for five days. Comprehensive medical examinations immediately before, after, and 4 to 5 weeks later failed to demonstrate any adverse health effects, and all the blood chemistry and urinalysis tests were negative (Fisher Rosner, 1959). Pivovarov et al., (1977) reported that ingestion of foods contaminated with  B. thuringiensis gastroenteitis at concentrations of 105 to 109 cells/g caused nausea, vomiting, diarrhoea and tenesmus, colic-like pains in the abdomen, and fever in three of the four volunteers studied. The toxicity of the B. thuringiensis gastroenteritis strain may have been due to beta-exotoxin (Ray, 1990). In a purified form, some of the proteins produced by B. thuringiensis are acutely toxic to mammals. However, in their natural form, acute toxicity of commonly-used  B. thuringiensis varieties is limited to caterpillars, mosquito larvae, and beetle larvae (Swadner, 1994). Special Concerns about B. thuringiensis Toxicity The earliest tests done regarding B. thuringiensiss toxicity were conducted using B. thuringiensis var. thuringiensis, a B. thuringiensis strain known to contain a second toxin called beta-exotoxin (Swadner, 1994). The beta-exotoxin is toxic to vertebrates, with an LD 50 (median lethal dose; the dose that kills 50 percent of a population of test animals) of 13-18 milligrams per kilogram of body weight (mg/kg) in mice when injected into the abdomen. An oral dose of 200 mg/kg per day killed mice after eight days (swadner, 1994) Beta-exotoxin also causes genetic damage to human blood cells (Meretoja, 1977).