Performance Appraisals Influence Of Employee Attitudes - Free Essay Example

Sample details Pages: 13 Words: 3957 Downloads: 2 Date added: 2017/06/26 Category Management Essay Type Analytical essay Did you like this example? If people read a limited number of articles on Performance Appraisal (PA), they will end up discovering that, huge arguments are kept with regard to PA. People may end up with conclusions that vary from, PA being so intrinsically defective that it could almost be impossible to perfect it. This as a result this could end up being the reason for an organization to end up in bad conditions that may eventually be the cause of its demise. Don’t waste time! Our writers will create an original "Performance Appraisals Influence Of Employee Attitudes" essay for you Create order This research takes a deeper look at PA as a whole, a few current as well as previous views on the process of giving feedback(appraising) will be revealed, which include the defining of traditional and developmental approaches. The most frequently used PA techniques will be taken into account as well. Later on, the author discusses the attitudes of employees and their behavior and existence, how they are formed and which of the particular attitudes and behaviors tend to be desirable ones that can, raise company performance. The effect of job related attitudes, satisfaction or dissatisfaction of jobs, will also be covered to perceive what are the pros and cons of a PA system, so as to make it easier to, understand the basic necessity of PA. In the final stages, the paper shall focus on, the effects of PA on different attitudes and at what time it would be appropriate to make use of which PA procedure to arrive at an anticipated target (attitude or behavior). Deliberations wit h regard to PA application will be taken into consideration to reduce any amount of ambiguity that may be in the minds of the reader. PA Although PA as a unique management system dates back from the 1940s, in a broader sense, the application of appraisal is a very antique art, appraisals come in the category of really old and long lasting professions.3 Through it citizens/society or the labor force are inclined to evaluate themselves along with others too. Describing PA In an organizational setting, PA could be described as a formally planned communication linking a employee and employer, which generally take the form of a sporadic interview once a year or more often, in which the performance of the concerned staff/employee with regard to their work is examined and discussed, along with a vision to identify the pros and cons including the likelihood for improvement and skill advancement. PA has been portrayed by Moorhead and Griffin (1992) as the process of evaluating work behaviors by measurement and comparison to previously established standards, recording the results, and communicating them back to the employee. It is an activity between an organizations manager and his/her employee.4 Performance Appraisal Systems (PAS) started in various companies as simplistic methods to decide whether an employees salary was justified or not. With the passage of time, different studies exposed with the purpose of pay rates as presumed before, were not the only factor that could have an influence on employee performance.3 Time proved that additional issues, like self-esteem and morale, may well also have a key impact. This ended up with the progressive rejection of importance of PA on the outcomes of rewards, and in the mid 90s, the prospective of PA as a means for motivation and development started to get acknowledged as another aspect with time. Appraisals within a company cause severe problems when they are carried out without any set of laws. If carried out in such a manner it can end up damaging the companys working environment and be the cause for the reduction in the proper output level, it may also can up being the cause of both legal and ethical troubles.3 Managers need to be conscious all the time of their doings and which consequences could it bring about when appraising performance. Within a large number of organizations, the link of the results of appraisal, have an impact on remuneration in some way. To be precise , the more finer the employee performs the more chances of him/her getting pay increments, bonuses or even promotions. On the other hand the employee whose performance is low might end up getting some advice on how to improve himself or herself or in more severe cases may end up in trouble by being demoted, getting a reduction in monthly/annual pay or even being dismissed from the company.3 Oberg has listed goals of PA programs, which are as follows: to assist supervisors to perform a coaching job in a more improved manner; to inspire the concerned employees by providing appraisal (feedback) on their performance; to make available the necessary data to help in administrative decisions like, increases or decreases in salary, removal from duty or even changing of working areas; to help pick up an organizations improvement by identifying the staff with promotion prospective; and finally to set up a study and indication base for human resources decisions.5 PA is an ingredient of a performance management that needs to be taken into consideration that includes activities to ensure that goals are consistently being met in an effective and efficient manner.6 When looked at carefully a variety of practices are involved in performance management besides those of PA. For example, performance management is involved in, performance improvement of employees, training and cross training, performance development, career development/coaching.7 AdoptedfromSource:https://images.google.com.pk/images?hl=enHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiq=performance%20appraisalHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wium=1HYPERLINK https://images.google.com.pk/images?hl=enq=performan ce appraisalum=1ie=UTF-8sa=Ntab=wiHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiie=UTF-8HYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wisa=NHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=wiHYPERLINK https://images.google.com.pk/images?hl=enq=performance appraisalum=1ie=UTF-8sa=Ntab=witab=wi There are researchers as mentioned earlier, who believe that Performance Appraisals (PAs) have never shown to be a reason for performance improvement. Rather they believe that PAs are used in organizations today only for the documentation of poor performance (a step that leads to the terminating process).8 Traditional vs. Developmental PA Methods Scholars have mentioned that, there have been two methods to PA. These include the traditional and the developmental methods. Traditional methods basic concern was in general with the organization as a whole, which is involved with the past performance. On the other side the developmental method, considers the staff as individuals along with being a bit more constructive by looking forward through the use of setting goals.9 The traditional method of PA used for various purposes, such as promotion, feedback to employees, reward decisions etc On the other hand the developmental method to PA brings about additional purposes, like providing the organization or company staff the chance to officially specify their direction and ambition, presenting the concerned organizational interest in staff/employee improvement, and to provide the employees who are literally trying to perform well, with satisfaction and encouragement.9 PA Methods There are various methods of Performance Appraisals (PAs), such as Annual Confidential reports (ACRs), essay methods, Management By Objectives (MBO), etc 5 Every PA procedure has, its own mixture of strengths and weaknesses, thus they ought to be used in relevance to the desired goals to make the procedure used more effective. PA software has been used in different parts of the world. It is also referred to as electronic performance monitoring.11 It tends to reduce the time to get through the appraisal process, which eventually helps management of organizations save time and money.12 But this method has also come under a lot of argument that it is not correct as, it stops the communication link between the employer and employee, due to which many term this process as ineffective and a waste of money and time.13 Employee Attitudes and Behaviors What is an attitude? An attitude may be described as a learned predisposition to respond in consistently favorable or unfavorable manner with respect to a given object (Kreitner and Kinicki, 1992).14 Moorhead and Griffin (1992) suggest two views of attitudes: Dispositional view implies that attitudes are steady dispositions toward an object. Putting this in mind, attitudes have three fundamental components: influence (affecting sense toward the object), cognition (the opinion of the information about the object) along with the purpose (an planned behavior toward the object). Situational vision contends that attitudes develop from publicly constructed realities.4 Attitudes on the whole are formed through the passage of time that could, be changed and might be influenced through an administrator/manager. A tool that is used for the initiation of attitude change is PA. However, there is an important finding that states: a result of research of 5,000 middle-aged male employees portrays that their job attitudes as a whole seem to be very stable over a period of five years.14 Job-associated attitudes The way Employees interact or their attitude that they depict is very essential for an organization, as employee interaction and attitude tends to show the way to the preferred behaviors. Moorhead and Griffin (1992) talk about two main job-related attitudes, that are, the level of job satisfaction and dissatisfaction. They describe this with following in mind, a persons attitude toward his/ her job. If the attitude is positive, the employees under the spot light are said to be satisfied. Dissatisfaction on the other hand comes into being, when the attitude is negative.4 These attitudes tend to take place due to the following three factors. The first factor being, organizational factors, for example, promotion opportunities, the work itself, working conditions and pay, the second factor involves grouping factors that comprise of, coworkers and supervisor; while the third factor focuses on personal factors for example, contributory benefits, needs, and ambitions.4 The attitudes of job satisfaction and dissatisfaction are extremely crucial, as both have the tendency to persuade how good employees, and therefore as a result an organization perform. In general the attitude of Job satisfaction tends to lead towards the desired course of action like, low absenteeism rate of the staff. Whereas if employee attitude leads to job dissatisfaction, that infers to the fact that, the rate of employee absenteeism, increases.4 Moorhead and Griffin (1992), mention additional attitudes that are essential and work related. These comprise of Involvement and Commitment. Involvement describes a persons willingness as an organizational citizen to go beyond the standard demands of the job. On the other hand Commitment may be said to be the concerned individuals feelings of identification with and dedication to the organization,4 The Influence Performance Appraisals can have on Employees Attitudes Previously the author has mentioned several types and techniques of PA, along with the attitudes that an employee may possess. This portion of the paper tends to focus on presenting how appraising performance can have, an influential effect on both the employees attitudes and behavior. Archer North offer suggestions that state that just individual recognition (appraising performance) alone, could end up leading to a higher rate of job satisfaction and reduce the absenteeism. People the whole tend to prefer negative feedback rather than no feedback/recognition at all.3 With the help of traditional methods of appraisals, managers/supervisors rate the performance of the concerned employee annually. This usually tends to reflect the recent events, which turn out to be a huge disadvantage.15 As managers lack communication with the concerned employees during the year, and this tends to mess things up. This usually causes the concerned employee being faced with the complete list of the flaws he/she made during the year, which also creates an uncomfortable situation for the concerned employee.13 With the due passage of time the 360-degree feedback system was introduced. Dezenzo and Robbins (2002) describe the 360-degree process as an appraisal devise that seeks performance feedback from such sources as oneself, bosses, peers, team members, customers, and suppliers has become very popular amongst contemporary organizations.15 The consequences of specific PA procedures may have on employee attitudes The correct or appropriate decision on what PA method is to be used is vital for the rest of the procedure. For the sake of employee motivation through the use of giving them feedback with regard to their work, work-standards or the MBO approach could be superior quality picks. But this is possible only with the involvement of real participation, as only then would it be able to lead towards internal commitment to improved performance.5 The MBO method of PA could, defeat a few of the problems that arise after supposing that the employees traits needed for the job at hands achievement can be dependably known and calculated. The MBO technique tends to center its focus on actual outcomes. As a result this method might provide a sense of autonomy, satisfaction and achievement for the employees. On the contrary this method could also be counterproductive by leading to impractical hope concerning what can and cant be rationally done.3 Time has revealed that through the setting of g oals we can achieve a major milestone in employee motivation. Goals are able to inspire employees effort, center attention, boost determination, and encourage them to figure out enhanced ways to work.18 To show what effects PA may have on employee attitudes, a study which concentrated on Matthew effect is to be used. Matthew effect is supposed to take place where the concerned staff tends to keep getting the same appraisal results, year after year. Meaning that, their appraisal results tend to become self-fulfilling: if they have performed well, they will carry on to do well; if they have done poorly, they will carry on to do poorly. This study that concentrated on the Mathew Effect discovered, a degree of frustration escalating due to biased PA. If we apply the Matthew effect to the workforce then we would be able to observe that a majority of good performers would end up happy with the appraisal system, while a majority of low performers would feel the system corrupt. When e mployees get a good appraisal or who themselves are high performers, the answer that you are likely to get to a question like does your supervisor listen to you and does he/she support you?, would be yes. On the other hand if the same question is asked from low performers a majority would answer no to the same question. When looked at carefully its very vital to give the low performers a chance to improve their appraisal results. If this chance of improvement isnt allowed then there is a very severe defect in the appraisal system as a whole.19 Many authors have the opinion, out of which Heathfield is one, that, employees usually turn defensive when their performance is under assessment. Differences about involvement and performance ratings can produce a argument ridden condition that can go on for months to come.16 Through studies conducted by the author, negative feedback from PAs can be a cause of the employees motivational level to stand at zero which may cause the employee s to perform worse. It is usually that staff which tend to comprise a level of high self-esteem to be able to get inspired through criticisms that, they take positively to develop their overall performance.5 A study conducted by Baron states that, harsh condemnation, that tends to be inexplicit, unjust or sternly presented will tend to lead to troubles like rage, bitterness, strain and conflict within the workplace, along with an eventual rise in the resistance for betterment, refutation of difficulties, and inferior performance.20 With the view above mentioned implications it needs to curtain these implications very seriously. Here it could be said that the appraising personality delegate his/her powers to a person who uses the process of appraisal as an opportunity of how things can be done in a better manner which would also eventually improve the overall working style or performance of the whole company or organization at hand. According to Levy, Cawley and Foti The tradi tional top-down approach to PA has been targeted time and again for not being able to hold a steady/satisfactory pace with the progress toward more participative companies or organizations of the last decade. The impact of this is that many organizations have had to adopt newer PAS which end up utilizing numerous feedback sources, the 360-degree feedback systems is a good example. Therefore the author believes its essential that the appraiser/appraisers need to be well-informed and dependable. When this happens, only then we can end up with better chances that the employees tend to overall visualize the concerned appraisal process as accurate and fair. If this ends up being the case then, there is a chance that employees will tend to acknowledge and even confirm their acceptance with regard to the evaluators appraisal and as a result will increase their readiness to improve for the better.21 Different research studies have shown the likelihood of employees to feeling more gratifi ed with their feedback result which we often term as the appraisal result if the concerned staff discussed here is provided with the opportunity to freely express and tends to even present their performance with the concerned party. When done, the chances of the concerned employees improving their performance for the better increases along with their potential to meet future performance, as the discussion with the concerned parties also increases the chances of the workers know what is required from them.22 Standards of comparison need to be present. As employees consider it essential to find out the performance of their duties and the area that asks for improvement or in other words the areas in which improvement is required. Essentially at this point we need to place the thought in mind that appraisals are not associated with condemnation (criticism). On the whole the fact could prove vital, which is to make clear the significance of finishing responsibilities inside the sugges ted timelines or even through the change in procedure if required of doing a task, to get the work done correctly. Regrettably, many PAs end up frustrating the concerned employees by the accumulation of additional responsibilities to what seems to be an already overloaded program.23 Anyone who is involved in giving PAS needs to be conscious of those staff that are always in the hunt of feedback. This declaration as revealed by Larson, whilst low performing employees pursue to get feedback from his/her immediate boss or even the superior at unusual times, when the concerned party to give feedback is not really ready to give an accurate or frank assessment. At the time when such a situation arises a manager tends to provide encouragement. The problem tends to arise at the appraisal time when the employee tends to recall all the encouragement given by the appraiser before the appraisal. As if the appraisal is negative the employee, considers the appraiser untrustworthy and therefore could consider his/her appraisal as being out of track. This in turn could get the appraisers in a fix that, might then force them to defend themselves, and could give a false appraisal that makes the employee satisfied. This incident could be simply avoided if, the appraiser informs the, feedback-seeker appraise to appear at another time when the appraiser is free.24 Considerations that could provide a link of performance appraisal with regard to compensation Those scholars, who believe in PA, as bring about big considerations that ask whether PA ought to be linked to compensation. The main blow against the linking of PA from reward decisions is the thought that this link might end up building a frightening and a theoretically disciplinary system.3 Another confrontation as described by Archer North, is that the linkage of compensation tends to dissolve the essence progressive appraisals. This can be proved through the fact that a majority of employees/workers would not admit their work. Specifically when, their contract renewal date is just around the corner.3 One should never forgo the fact that the rater feels a sense of tension or nervousness when they have to do an appraisal. Specially, if both the appraiser and appraise have good terms with each other outside work. As both the appraiser and appraises relation can be destroyed in the event of a negative appraisal being given. This itself could create enough damage to the workp lace environment that the productivity of the organization as a whole could be hampered.3 Although all this portrays is that appraisals should not be linked to compensation, there are scholars who believe that the link should be there. Their thought follows the motion that there is a need to have a smooth system where one can fairly link compensation. They tend to believe that PA is a unique and one of its kind system, through which they can end up giving compensations to all in a fair and just manner. Many employees/workers who tend to get compensations properly, consider PA as a trustworthy way to get their due compensations.3 This has further been acknowledged through a research by both Bannister an Balkin where they found out that appraisees feel more comfortable when appraisals have a direct link to compensation.25 While a study conducted by some scholars had the following finding; Using a sample of more than 15,000 employees, we found that pay satisfaction is the highest wh en performance pay is tied to the employees performance and the lowest when there are no performance appraisals in organizations, even if there is performance pay.26 Conclusion Recommendations PAS are useful rather than useless as some scholars mention. Though with proper care and time given to understand the system which, involves, proper planning and using the adequate techniques to, get the system (PA) to bear fruit, by maintaining a proper long term understanding of the organizational environment and the organization as a whole. While in the process of this research the author was faced with vast views upon PA and its different aspects. There was vast material that was in contrary to giving PA a good image. This as a whole tends to prove that PA is very complex process and is also very difficult to do correctly. Special care should be taken when applying the Performance Appraisal System. As, different/relevant techniques can, differentiate between the system becoming a success or failure, special care has to be taken on how to approach the situation at hand. On the other hand, to enhance the usual lack of communication the PA process should take place more freq uently rather than the frequently used Annual system. The more frequent the appraisals, the better chances of the performance becoming better. The PA system should also be considered as a way to enhance worker performance and motivation rather than only being a tool being used as a guideline with regard to compensation along with promotions or demotions.

NCAA Drug Testing - 707 Words

The use of illegal substances is rapidly increasing in the college sports due to the expansion of supplements used by athletes that are being banned. In a study done, athletes were asked if illicit drugs would negatively impact their performance. Majority of them responded â€Å"yes†, their main reasoning being; the effects of illicit drugs were both mental and physically damaging. Illicit drugs come in many forms, but the testing procedures are all the same for any substance. There is almost always a consequence with the use of prohibited substances. Drug testing is appropriate to help ensure the safety of student athletes while they participate in intercollegiate contests. (Krotee, M 555). Before a contestant participates in the sport that he or she is anticipating, they first, must sign consent to participate in drug testing. This is a document that they must sign, which states that they are subject to random drug test, they must comply or suffer the consequences of not par ticipating. There are many categorizes of drugs, such as; stimulants, which can induce temporary improvements in both mental and physical function. Anabolic agents, which scored a 1.1% usagea at the college level,in the Study of Substance Use and Abuse habits(Green). Steroids are mostly taken by men, because they act as a testosterone. Caffeine, which is both a diuretic and a stimulant. caffeine is illegal in excessive amounts of 3-13 mg/kg of body weight(Maria). This much caffeine may improve ones resultsShow MoreRelatedPerformance Enhancing Drugs in Sports1207 Words   |  5 PagesThe growth and use of performance enhancing drugs makes them no longer a taboo subject among professional athletes, and is starting to become in fact rampant among athletes. 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Mobile Phone and Children Free Essays

Should children be allowed to own and use mobile phones? Mobile phones keep children safe Mobile phones keep children safer, as it is easier for parents to stay in touch with their children and for children to contact someone in an emergency. Through calls and texts, parents can know where their child is and be reassured that he or she is safe; all the while their children know they are never more than a phone call away from help. As Leslie Sharpe argues, ‘I wanted to ensure that they had a way of contacting me in an emergency’. We will write a custom essay sample on Mobile Phone and Children or any similar topic only for you Order Now It is, however, true that some children carrying the most sophisticated or ‘Smart’ phones are more susceptible to being robbed, but thieves are always after something new. Phones now are both much more widespread and security coded, so the benefits to thieves are no longer as great or immediate. Traffic accidents that are the result of children being distracted by their phones while walking across roads should be blamed on bad safety education rather than on the actual phones. Ultimately, mobile phones provide parents and young people with peace of mind and children with a safety net in emergencies, whether calling parents or the emergency services. Children should be comfortable with modern technology Information and Communication Technology (ICT) is now a normal part of modern life, used by everyone from toddlers to pensioners. So children need to grow up making use of technology such as mobile phones if they are to be able to fully participate in contemporary society. The average age at which children get their first mobile phone is eight according to a recent study. To prevent a child from having a mobile phone at that age is to put them at a clear social disadvantage compared with their peers. Mobile phone use develops skills for the modern workplace with its need for tech-savvy employees with communication skills and the ability to work flexibly. In any case, children often have better phone manners than adults – they are less likely to shout into the phone, more likely to text discreetly, and more aware of text and phone etiquette. Such manners are the direct consequence of familiarity with the device and an understanding of appropriate use in certain contexts. Mobile phones encourage the development of independence and interpersonal skills Education is as much about the growth in character and dealing with risks as it is the accumulation of knowledge; mobile phones provide for children a means to converse with peers, develop friendships and resolve disputes, all within minutes of each other, night and day. For them, ‘getting a cell phone is a step towards independence and a status symbol among their friends’. The confidence and self-esteem derived from having a mobile phone cannot be underappreciated, as proven by the corresponding negative impact of losing one’s phone. An Independent study in 2004 found that 55 per cent of people cited ‘keeping in touch with friends or family as the main reason for being wedded to their handsets’. Furthermore, the increasing potential of smart phones facilitates the accessing of information in real-time and on the move; a determined child with a grasp of the potential of their mobile phone can illuminate themselves on matters like directions to destinations, opening times for activities and immediate weather forecasts. With such information, children can begin to reason with each other and make decisions without resort to more mature advice. Schools can implement programs to encourage responsible and considerate mobile phone use All technological platforms have the potential to be abused or act as a negative medium, what is important is that children are taught to use their mobile phones responsibly. Schools should introduce programs and classes that teach children not only how important the devices are to their personal safety, but also how to exploit the advantages of the software. All children with sufficiently smart mobile phones should know how to find out where they are at any given time using map functions, and how to use the internet to find information on the go but to be vary of revealing their location to others and possible commercial exploitation of certain location based services. This advice should be taught alongside warnings about the limits of mobile phone technology, ensuring that the children don’t trust them blindly but use them as verification tools or means of starting enquiries. What should emerge is an environment where phones can be used as teaching tools and facilitating social cohesion rather than simply being a distraction in class. There are long-term health risks to mobile phone use Mobile phones are medically safe for children to use – we should ignore scare stories in the media. The latest research has not proved that mobile phones damage brain cells. Ed Yong, head of health information at Cancer Research UK, has been quoted as saying ‘the risk of brain cancer is similar in people ho use mobile phones compared to those who don’t, and rates of this cancer (glioma) have not gone up in recent years despite a dramatic rise in phone use during the 1980s’. Furthermore, the European Union’s public health body concluded in 2008 that ‘mobile phone use for less than ten years is not associated with cancer incidence. Regarding longer use, it was deemed difficult to make an estimate’. Even those earlier studies tha t suggested there might be a problem thought that people would have to use a cell phone for hours a day for there to be an effect. It is true that there is no 100% proof that mobile phones are safe to use, but that is true of any scientific study. Further investigation should be encouraged, but without conclusive proof, the benefits of mobile phone use will continue to far outweigh the costs. Mobile phones are too expensive for children Mobile phones are not too expensive for children – children use pocket money to buy credit and often inherit ‘hand-me-down’ handsets initially. As noted by the opposition, basic models are cheap and the subscription itself is at the mercy of the buyer. Parents can always say â€Å"no† or set limits on what the children can spend. With modern payment plans children can be given a set amount of credit for calls and texts. Learning to work within financial limits is an important part of growing up. In any case, many young people have part-time jobs so they are spending their own money, not their parents and learning to control use and financially managing phone use is a very good skill to learn. Nevertheless, even if it were the case that mobile phones are too expensive, that does not render their ability to keep children safe negligible, for one cannot place a price on a child’s safety. Mobile phones are inappropriate distractions in school Mobile phones are now a valuable part of student life. They can be used for ‘creating short movies, setting homework reminders, recording a teacher reading a poem and timing science experiments’. Moreover, because parents feel their children are safer carrying a phone, they are more likely to allow them to travel to school on their own rather than driving them. This promotes greater independence for the children, while taking traffic off the roads which is environmentally-friendly. Like many other things, mobiles can be distracting in class but this doesn’t mean they should be banned. Many chools allow – some actively encourage – phones to be carried providing they are turned off in lesson. Mobile phones are open to abuse Anything can be abused or used to harm other person, including pencils and paper. New technology carries some risks but we should not be rushed into panic measures. Children got hold of pornography, gambled and bullied each other lo ng before mobile phones were invented. The relationship between childhood and new mobile technologies is complex. These problems won’t go away if we ban phone use – they can only be dealt with through good parenting and moral education. In the meantime, parents can get phones which block inappropriate content, and ensure that their children do not have credit cards to pay for it. They should make sure that children know how to report abuse or what to do if they receive inappropriate material on the phone. An American company Disney Mobile is also one of an increasing number of phone makers who ‘provides families with mobile phones specifically designed for tweens, young teens and parents who want to keep an eye on them’. The potential for the abuse of mobile phones is low if parents are informed and vigilant and ensure they buy their children the right phone and right plan. How to cite Mobile Phone and Children, Papers

Showing cardiovascular and ventilatory responses at rest and during exercise free essay sample

Abstract Objective: The objective of this experiment is to analyse how the cardiovascular and respiratory parameters are affected by steady state exercise. Method: The experiment was split into two stages, rest and exercise. A spirometer, an ECG, a Douglas bag and a blood pressure monitor were used at rest on the subject. In the exercise phase a Douglas bag and the blood pressure monitor were used to measure the subject’s volume of air and blood pressure respectively. Results: A positive correlation was calculated for the heart rate, total volume, oxygen consumption, CO2 production, pCO2, and % of CO2, minute volume, ventilation rate, mean arterial pressure and the number of breaths when the subject was exercising. The pO2, the %O2 and the respiratory quotient showed a negative correlation in the exercise phase. There was no significant change in the diastolic pressure in the exercise phase. The change in tidal volume, the systolic pressure and the pulse pressure during the exercise phase showed to vary against theoretical values and would require further studies to explain these readings. Conclusion: In conclusion many of the parameters that were calculated supported previous experiments; however the tidal volume, the systolic, diastolic and the pulse pressure were not conclusive enough to observe any significant trend. Introduction The human body is a complex machine with many mysteries yet to discover. When the human genome project finished we had learnt much about our DNA and how complex the structure is. We had just scratched the service of our true potential. Our DNA plays a major role in whether we have a good or poor cardiovascular system. This is also the same for our respiratory system. Environmental factors also contribute to how effective our cardiovascular and respiratory system can be. Every so often people from different ethnic backgrounds complete against each other in events such as the Olympics and World athletic championship. Studies have shown that when exercise begins there is a rise in the cardiac output that is a consequence of an increase in the stroke volume and heart rate due to the increase in blood circulation, there is a redistribution of the blood to the working muscle by vasodilation and vasoconstriction of the arterioles (coote, 1995). With this the body adapts to changes during steady state exercise to optimise the performance and to prevent any injuries than can occur. Steady state exercise is when the body is performing at a moderate level of exercise producing a balance between production of lactic acid and the removal of lactic acid through oxidation (Thompson, 2008) Exercising on a daily basis results in an individual maintaining a healthy and balance lifestyle. A study in North America showed a group of elderly individuals between the ages of 55 to 70 performed aerobic exercises for four months. The results showed that the experimental group improved their maximal oxygen consumption by 27% (Steinhaus, 1983). This study shows that even at senior age, exercises improves the resting heart rate, systolic blood pressure at rest, sleep habits, well being, hemodynamic and overall lifestyle changes. This study also included anaerobic exercises which too showed an improvement of the individual’s health. On some occasions the production of lactic acid exceeds the removal of lactic acid. This usually occurs when the VO2max is between 55% and 65% in healthy and untrained athlete, however in highly trained endurance athletes this value can reach at 80% (McArdle, Katch Katch, 2006). This is known as the onset of blood lactate accumulation (OBLA), which refers to the level of lactate in the blood reaching around 4mM. L-1. Exercise physiologist traditionally used VO2max as the main benchmark to measure endurance exercise. This however does not fully explain all aspect of the athlete’s ability to do well in a race. An experienced long distance athlete commonly trains slightly above the point of OBLA (McArdle et al. , 2006). Currently measuring exercise intensity by the OBLA has been a more effective and accurate way in indicating the individual’s level of fitness (McArdle et al. , 2006) The causes for OBLA have not been conclusively proven; as many believe it represent the point of muscle hypoxia which is when there is an inadequate supply of oxygen that is being sent to the muscles (McArdle et al. , 2006, p 320). However the muscle lactate accumulation does not necessarily coincides with hypoxia, because the lactate in the blood can be formed even when there is a sufficient supply of oxygen. Nevertheless the imbalance between the production and elimination of lactate in the blood can cause OBLA (McArdle et al. , 2006). In this experiment the aims were to use different equipment to measure a range of cardiovascular and respiratory parameters and to investigate the ways in how the body of a healthy young individual responds to the changes when undertaking aerobic exercise at a stead state level at different intensities. The cardiovascular parameters were the heart rate, mean arterial pressure, systolic and diastolic blood pressure, pulse pressure and the subject cardiac rhythm using an electrocardiogram. The respiratory parameters were the tidal volume, vital capacity, oxygen and CO2 percentage, the number of breath in each minute, ventilation rate, oxygen consumption, CO2 production, the respiratory quotient and to analyse how the aerobic response changes at different intensities. Material and method This experiment was performed by using the guideline set in the University of Hertfordshire ‘Level 1 Human Physiology Practical Booklet’ code number 1LFS003. The following changes were made and these amendments were about the level of resistance. At level two the exercise power was changed from 80W to 75W and the same went for level three from 110W to 100W. And instead of using only two levels that were indicated in the practical booklet at page 20, a third level was initiated which had a workload of 75W. When using the spirometry, instead of using a counter-balance gas holder with a writing pen attached to the counterweight, all spirometry parameters were recorded using the computer and the subject just has to inspire and expire through a tube that is connected to the computer. Results The subject’s BMI was calculated using his height and weight measured before the start of the experiment. The total practical time was three hours in which the first hour was used to measure the control variables and ECG. The remaining two hours were used to test the different physical levels and write down the data. The %O2 was measured in the Douglas bag decreased as the intensity of the exercise increased; while the %CO2 was increasing resulting in the pCO2 and the pO2 to increase and decrease respectively. Both the O2 consumption and the CO2 production increased with each level; however the rate of CO2 production was greater than the rate of O2 consumption causing the respiratory quotient to be higher than one. The number of breaths where increasing as the intensity of the exercise increased, but the value for the control was higher than each level. This caused the total volume of air in the Douglas bag to increase but the total volume of the control was higher than level one but not for level two or three. As the volume of air increased so did the ventilation rate and the minute volume. However the tidal volume did not have a linear pattern. Between the control and level one there was a sharp increase in the tidal volume, but during level two and three the tidal volume started to decrease. Figure 1 shows the CO2 production and the O2 consumption at the different exercise intensity. There was a large increase in the subject’s heart rate from the control to level one and from level one to level two, but from level two to level three the heart rate started the plateau. Figure 2 show how each exercise power affected the heart rate of the subject. The systolic pressure increased dramatically from the control to level one. But there was a decrease in the systolic blood pressure from level one to level two and eventually a rise in the systolic blood pressure from level two to level three. The diastolic pressure decreased from the control to level one and from level one to level two the diastolic blood pressure increased. At level two to level three the diastolic pressure decreased. Both the diastolic blood pressure at level one and three was lower than the control value, which caused the pulse pressure to be similar during level one and three but the pulse pressure during level two was very different. With the changes of the blood pressure that occurred during each level the mean arterial pressure increased gradually from the control to level three. Figure 3 shows how the blood pressures were affected by the change in the exercise intensity Before the exercise we tested the subject’s lung function by using a spirometer. Figure 4 shows the respiratory parameters of the spirograph. The ratio of the force vital capacity (FVC) and the force vital capacity expired in one second (FEV1. 0) was above the normal value of 85% (McArdle et al. , 2006, p 298). An electrocardiogram was also carried out to determine the subject’s heart rate and to analyse each wave of a single cardiac cycle. Figure 5 shows the ECG of the subject showing the different waves in a single cardiac cycle. The T wave represents the repolarisation of the ventricles, the P wave represents the depolarisation of the atria, the QRS complex is the depolarisation of both ventricles, as the ventricles is larger in size than the atria; the QRS complex has a larger peak and trough. The RR interval is the time taken for the R wave to appear again on the ECG (Fox, 2011). The ECG shows that the subject has a normal heart rate subjected to his age. Discussion Our major findings is that there is a decreasing trend in pO2, %O2, the respiratory quotient, and the diastolic blood pressure while there is an increasing trend in pCO2, %CO2, heart rate, systolic and mean arterial pressure, all respiratory parameters except for the O2 levels. As the exercise power increased the %O2 and the pO2 decreased which causes the working muscles to require more oxygen to keep up with the demands of the aerobic intensity. However the level of expired CO ­2 that is collected in the Douglas bag increased as the intensity increased. This is due to the increase production of CO2 in the working muscles during respiration. In all, the level of oxygen consumed and CO2 produced caused the respiratory quotient to be slightly above one. The respiratory quotient is the ratio between the total amounts of CO2 that is being produced to the amount of oxygen needed (McArdle et al. , 2006, p 240). During the exercise phase, the subject was catabolising the carbohydrates that he consumed prior to the experiment. As the values are very close to one, all the calories were derived from the carbohydrates that the subject consumed (McArdle et al. , 2006) The subject’s tidal volume increased from the control to level 1 where there was a peak at level one. The increase in the tidal volume from the control to level one was when the ‘demand for energy increases, the tidal volume increases by expanding into both the inspiratory reserve and the expiratory reserve’ (Smith Plowman, 2008). However during level two and three the tidal volume started to decrease. This cannot be explained as sources say that exercising actually increases the tidal volume (Garrett Kirkendall, 2000) and so further investigation is needed to be performed at different exercise power. The spirometer was used to measure the subject’s lung function and this instrument would have indicated if there are any obstructions present in the airways. By using the ratio between the FVC and FEV1. 0, the subject can be identified in having any lung obstruction or none at all (McArdle et al. , 2006). The spirometer produced an accurate value of the tidal volume at rest, while using the Douglas bag breathing forcefully can overinflate the bag which can produce an overestimation of the tidal volume. Also determining the number of breaths was difficult as the non returning breathing valve was moving very quickly to accurately count it. The parameters that were measured were the total lung capacity, inspiratory reserve volume, expiratory reserve volume, residual volume, vital capacity, functional residual capacity and tidal volume. The value of the subject’s tidal volume using the spirometer was 1. 5L. This value exceeds the average value of 500ml which has been given in many different studies of a young adult male (Normal breathing, 2010). This shows that the subject has a large lung capacity, indicating that the subject has maintained a good level of fitness. During exercise the heart rate increased due to the CO2 levels stimulating the chemoreceptors in the aortic arch which overall results in an individual inspiring more O ­Ã‚ ­2 and expiring CO2 quickly (McArdle et al. , 2006). With an increase in the heart rate the systolic pressure of the blood vessels also increased. Systolic pressure is the pressure in the aorta when the ventricles are contracting’ (McArdle et al. , 2006, p334), and due to the heart rate increasing at each level the systolic pressure correlates to the change in the heart rate. The diastolic pressure is the filling of blood to the arteries when the muscles are contracting. The trend, with the value at level two ignored, see that as the exercise power increases the diastolic pressure decreases. This is because the blood vessels dilate which in turn reduced the diastolic pressure (R. Noah, personal communication, June 7, 2000). The mean arterial pressure is the average blood pressure of an individual during a cardiac cycle. The value of the mean arterial pressure increased gradually when the exercise intensity increased because of the systolic pressure increasing at a greater rate than the diastolic pressure, which deceased relatively slow. The ECG and the blood pressure monitor were used to measure the subject’s heart rate and blood pressure respectively. Both ECG and the blood pressure monitor measured the heart rate as similar values when the subject was not exercising. While the blood pressure monitor only measures the heart rate, the ECG is used to detect if the patient’s heart is beating normally. The results from the ECG indicate the subject’s heart is beating at a normal rate and rhythm. However during the practical the value of the blood pressure during level 2 did not match with the other levels and the control. The systolic pressure was lower than the systolic pressure of the control. This is due to an error that was occurring with the machine when the subject’s blood pressure was being measured and the fact that the subject was perspiring which caused the machine to slip, making it difficult to acquire an appropriate reading. With the error present at level two the value for the mean arterial pressure was also an anomaly. To make sure how results were reliable a second reading for each level was planned however, there was a time constraint which prevented the use of calculating an average. During the beginning of the practical, the subject found it difficult to maintain the speed of 50 rpm which was prescribed in the practical booklet, which could have made the value inaccurate. Some other areas where this experiment can go further is the difference in the respiratory and cardiovascular parameters between different gender groups. They have been a few studies with regards to male and female such Leddy, Horvath, Rowland Pendergest (1997) which mentions the effects of a high or low fat diet on the cardiovascular factor between female and male runners. Another factor to consider is the use of age and how that affects the cardiovascular and respiratory parameters. Introducing subjects who have illnesses such as asthma, chronic obstructive pulmonary disease or other cardiovascular co-morbidities would show how the heart is working when it is damaged. The one problem is that the subjects would need careful monitoring by healthcare professional. As this experiment was focussing on the aerobic exercise, an anaerobic experiment can be implemented with subjects that are trained athletes and untrained athletes to see the difference in their cardiovascular and respiratory parameters. You could also include male and female subjects with the similar athletic background to perform some anaerobic experiments to see if there are any significant differences between the two. You could also introduce different ethnic groups and see if there is any significant difference in the results. Reference Coote, J. H. (1995): Cardiovascular responses to exercise: central and reflex contributions in JORDAN, D. , and MARSHALL, J. (Eds): Cardiovascular regulation (Portland, London, 1995), Garrett, W. E. , Kirkendall, D. T. (2000). Exercise and sport science. Philadelphia, Lippincott Williams Wilkins Leddy, J Horvath, P. , Rowland, J. Pendergast D. (1997) Effect of a high or a low fat diet on cardiovascular risk factors in male and female runners. . Medicine and Science in Sports and Exercise, 29(1), 17-25 Normal breathing (2010) Amazing DIY breathing device. [online] Available at: http://www. normalbreathing. com/nb-word/DIY-device-short-2010. pdf [Accessed: 5 Jan 2013]. McArdle, W. D. , Katch, F. I. , Katch, V. L. (2006). Essential of Exercise Physiology. (3rd ed. ). Santa Barbara: Fitness Technology, Inc. McArdle, W. D. , Katch, F. I. , Katch, V. L. (2001). Exercise physiology: energy, nutrition, and human performance. Philadelphia, Lippincott Williams Wilkins. Smith, D. L. Plowman, S. A. (2008) Exercise physiology for Health, Fitness and Performance. (2nd ed . ). Baltimore: Lippincott Williams Wilkins. Steinhaus, L. A. (1983). Cardiovascular Response to Exercise Training in the Elderly. Unpublished thesis, University of Utah, Utah Thompson, G. , James, N. W. James, R. (2008). OCR PE for AS. Oxon: Bookpoint Ltd. Raizwan. N. (June 7, 2000). Blood pressure. Message posted on MadSci Network, archived at http://www. madsci. org/posts/archives/jun2000/960410763. Me. r. html. Appendix All the results that were made were placed into a table with each level indicated and the control as well. The table below shows the respiratory and cardiovascular parameters of the subject during rest and exercise. Table shows the cardiovascular and respiratory parameters of the subject at each level and the baseline of the O2  ­and the CO2 in the classroom. To calculate the mean arterial pressure you: As the mean arterial pressure indicates the average blood pressure of a human, the diastolic phase is longer than the systolic phase, hence the reason to multiply the diastolic pressure by two. By using the values of the blood pressure the mean arterial pressure can be calculated: The ventilation rate is the rate at which the air move into the lungs and out of the lungs. This can easily be calculated by the following equation: This is the value at the control level: When calculated the ventialtion rate it is more effective to calculate the mintue ventilation instead as this corresponds to the amount of air that enters and leaves the lung in one minute. This is also a pretty sraight forwards equation: The minute volmume is used to indicate a quantitive value to the minute ventilation as the minute volume is about the amount of air inspired and expired in one minute. The minute volume is the product of the tidal volume and the minute ventilation as shown in this equation: The partial pressure of the two gases, oxygen and CO2 are used to measuere the amount of oxygen and CO2 that are being expired by the body. The equations for the two gases are shown below: The oxygen consumption is the amount of oxygen that the person inspires and transported to the cells by haemoglobin. This is to measure the efficiency of the subject; how much oxygen is that person actually using? The equation is: The CO2 production is the amount of CO2 that is expired from the lungs by the process of gases exchange between oxygen and CO2. Through the process of respiration, the cells produce CO2 as a waste product, and with the help of diffusion, the pCO2 in the cells is higher than in the blood stream so diffusion takes place. The equation is: The respiratory quotient is used to measure what type of fuel the individual is consuming (McArdle et al. , 2006) and the equation is shown below. The peak expiratory flow is used to determine how fast the person is able to expire and is used to test the function of the lungs and to see if there are any obstructions are present. The equation and example are: The equation for the FEV1: FVC and example that was used during the experiment: To calculate the BMI: The value of the subject’s BMI was:

Investigate the Energy Change during Neutralisation Reactions Essay Example

Investigate the Energy Change during Neutralisation Reactions Essay * Calorimeter This polystyrene device will hold the acids in the neutralisation reaction. This has been used, as it is a very good insulator of heat so as little as possible will be lost.* Burette This glass device can hold 50 cm3 of liquid and will be used to pour the acid in 1cm3 amounts into the alkali. This device has been used, as it is very accurate and easy to use.* Thermometer This will be used to measure the temperature of the reaction after each 1cm3 of acid has been added.* Clamp Stand and Burette Holder These will be used to keep the burette in place so it does not fall over and break or spill acid.* Strong and Weak Acid Hydrochloric acid or sulphuric acid will be used for the strong acid and ethanoic acid will be used for the weak acid. 40 cm3 will be used to neutralise the alkali.* Strong and Weak Alkali: Sodium hydroxide will be used for the strong alkali and ammonia will be used for the weak. We will use 15cm3 of alkali at 1 mole per decimetre cube concentration. Preliminary WorkPreviously I performed a thermotitration with a strong acid and a strong alkali and I found that the following quantities would be suitable for my experiment: 15cm3 of alkali would neutralise well within 15% accuracy compared to the theoretical energy output. We also decided to use a 1-mole/dm3 concentration as we found 0.5 mole/dm3 was too little for a good result, and 2 moles/dm3 was too violent. The preliminary work also showed that it was necessary to use a good insulating material to house the reaction in and we also needed to use very accurate equipment.SafetyAs with any experiment there are safety issues that need to be followed. Many of the acids or alkalis used in this experiment are corrosives or irritants therefore safety goggles must be worn at all times. Also any spilt acids or alkalis need to be cleaned up immediately and any got onto skin or clothing needs to be washed up immediately. All equipment must be out of the way of walkways to avoid spillage a nd accidents. Smashed glass must be swept up immediately.Fair TestTo ensure this experiment is a fair test it is imperative that all tests are done in the same way. Any equipment to be used again after a test has been completed must be cleaned thoroughly to prevent any contamination in the next experiment that could affect the accuracy of the results.PlanWe will set up the equipment as shown below:As shown in the preliminary write up above I will be using 15cm3 of 1 mole/dm3 alkali and 40cm3 of acid at 1 mole/dm3. I will then use the burette to add 1cm3 at a time of acid to neutralise the strong alkali. After adding the strong acid I will then stir the solutions together to let them react and quickly take the temperature. I will then repeat this 40 times until all the acid has gone. I will then repeat this experiment for a strong acid against a strong alkali; a strong acid against a weak alkali; a weak acid against a weak alkali. Therefore I will be doing four experiments. To analys e the results I will be using the equation (mass x heat capacity of water (4.2) x change in temperature). This will give me the answer for the energy change in joules for however many moles there were in the concentration on acid. I will then need to find out the energy change for 1 mole so I will then work out the number of moles of acid there was using:Number of moles = volume (cm3) x concentration (mol/dm3)1000I will then divide the answer I got from the energy equation and divide this by the result of the above equation. Thus giving me the energy change for 1 mole of acid neutralising the alkali.PredictionFrom preliminary work and acid theory I can determine that in this experiment the reaction with the greatest energy change will be the strong acid reacting with the strong alkali. When an acid reacts with a base it dissociates to form ions. In the case of hydrochloric acid it will form H+ ions and Cl- ions. For this example almost all of the HCl will dissociate into ions howev er with a weak acid such as ethanoic acid only about 0.3% of the acid is dissociated into ions. The action of acids disassociating creates energy and therefore the stronger the acid the more energy. This rule also applies for the alkali bases. After doing some further preliminary work I found the theoretical values for energy produced in a neutralisation reaction. These values were as follows:Strength of acid/alkali (respectively)Energy (Joules per mole)Strong and StrongWeak and StrongStrong and WeakWeak and Weak-57,900-56,100-53,400-50,400As you can see this table proves my prediction to be right. I can use this table in my evaluation to see how accurate my experiment has been by working out the percentage error of my results.Prediction GraphsResultsSodium Hydroxide and Hydrochloric Acid (Strong and Strong) Start Temperature 19à ¯Ã‚ ¿Ã‚ ½CVolume of Acid (cm3)Temperature (à ¯Ã‚ ¿Ã‚ ½C)Cumulative Temperature Change (à ¯Ã‚ ¿Ã‚ ½C)1.020.01.00.920.51.51.221.52.51.222.03.01.022.53.51. 123.04.01.023.54.51.024.05.01.124.55.50.925.06.01.025.06.01.025.56.51.126.07.00.826.07.01.025.56.51.025.56.51.025.06.01.025.06.01.025.06.01.024.55.51.024.55.51.024.55.51.124.05.01.124.05.00.924.05.00.924.05.01.024.05.01.024.05.01.023.54.51.023.54.51.123.54.51.023.54.50.923.54.51.023.04.01.023.04.0Ammonia and Ethanoic Acid (weak and weak) Start Temperature 19.5à ¯Ã‚ ¿Ã‚ ½CVolume of Acid (cm3)Temperature (à ¯Ã‚ ¿Ã‚ ½C)Cumulative Temperature Change (à ¯Ã‚ ¿Ã‚ ½C)1.020.51.01.121.01.50.921.52.01.022.02.51.022.53.01.023.03.51.023.03.51.023.54.01.224.04.51.024.04.51.024.55.01.024.55.01.025.05.51.025.05.51.025.56.01.125.56.00.925.56.01.025.56.01.025.05.51.025.05.51.225.05.51.025.05.51.025.05.51.024.55.01.024.55.01.024.55.01.024.55.01.024.55.01.024.55.00.924.55.01.124.04.51.024.04.51.124.04.51.024.04.51.024.04.51.024.04.51.024.04.51.024.04.51.023.54.0Ethanoic Acid and Sodium Hydroxide (weak and strong) Start temperature 19.5à ¯Ã‚ ¿Ã‚ ½CVolume of Acid (cm3)Temperature (à ¯Ã‚ ¿Ã‚ ½C)Cumul ative Temperature Change (à ¯Ã‚ ¿Ã‚ ½C)1.019.50.01.019.50.00.919.50.01.020.00.50.920.00.51.220.51.01.020.51.00.921.01.50.921.52.01.022.02.51.222.02.50.822.53.01.023.03.51.023.54.01.124.04.51.224.04.50.724.55.01.025.05.51.025.05.51.025.05.51.025.05.50.925.56.01.125.56.01.025.56.01.026.06.51.126.06.50.926.06.51.026.06.51.325.56.00.625.56.00.825.56.01.025.56.01.425.05.51.025.05.51.025.05.51.025.05.51.125.05.50.925.05.51.025.05.51.025.05.5Hydrochloric Acid and Sodium Hydroxide (strong and strong) Start Temperature 19.5à ¯Ã‚ ¿Ã‚ ½CVolume of Acid (cm3)Temperature (à ¯Ã‚ ¿Ã‚ ½C)Cumulative Temperature Change (à ¯Ã‚ ¿Ã‚ ½C)1.020.00.50.922.02.51.224.04.51.225.56.01.026.06.51.127.07.51.028.08.51.029.09.51.128.59.00.928.59.01.028.08.51.028.08.51.127.58.00.827.07.51.027.07.51.026.57.01.026.57.01.026.06.51.026.06.51.026.06.51.025.56.01.025.56.01.125.56.01.125.56.00.925.56.00.925.06.01.025.06.01.025.06.01.025.06.01.025.06.01.125.06.01.024.55.50.924.55.51.024.55.51.024.55.50.924.55.51.224.55.51 .024.55.51.024.05.0AnalysisFor the first test (sodium hydroxide and hydrochloric acid) I will analyse the results using the equation:- (mass x heat capacity of water (4.2) x change in temperature)Therefore the amount of energy produced is:- (15 + 11.2) x 4.2 x 6.7 = -737.3 joulesHowever the number of moles of alkali was only 0.015 moles worked out by the equation: Number of moles = volume (cm3) x concentration (mol/dm3)1000So the amount of energy produced for 1 mole is -737.30.015This equals -49153.3 joules of energy.For the second test (ammonia and ethanoic acid) the results are as follows:Mass (from graph) = 15.8Change in temperature = 5.9- (15 + 15.8) x 4.2 x 5.9 = -763.2 joulesThis answer, then divided by 0.015 to give the answer for 1 mole of alkali gives an answer of -50,880.0 joules of energyFor the Third test (ethanoic acid and sodium hydroxide) the results are as follows:Mass (from graph) = 22.8Change in temperature = 6.9- (15 + 22.8) x 4.2 x 6.9 = -1095.4 joulesThis answe r, then divided by 0.015 to give the answer for 1 mole of alkali gives an answer of -73,026.7 joules of energyThe fourth test is a repeat of the first test (hydrochloric acid and sodium hydroxide) the results are as follows:Mass (from graph) = 7.8Change in temperature = 9.2- (15 + 7.8) x 4.2 x 9.2 = -881.0 joulesThis answer, then divided by 0.015 to give the answer for 1 mole of alkali gives an answer of -58,733.0 joules of energyI would normally average the two results (for the first and last experiment) because they are repeats however the last result is very close to the theoretical value and if they were averaged this would not be the case so I will take the 1st result to be anomalous.For ease of reading and analysis I will put these results into a table and calculate the accuracy of my results from the theoretical results found in my preliminary workStrength of acid/alkali (respectively)Result from ExperimentTheoretical ResultPercentage Error:my answer true answertrue answerSt rong and StrongStrong and StrongWeak and StrongWeak and Weak-49153.3-58,733.0-73,026.7-50,880.0-57,900-57,900-56,100-50,40018%1%30%1%Average Error13%On the whole my results do support my prediction as for the reactions between both strong and both weak solutions the results only have a 1% error margin. Therefore my results show me that there is positive correlation between the strength of acid and the energy given off as heat in the neutralisation reaction.I believe this has happened because as stated in my prediction when an acid reacts with a base it dissociates to form ions. In the case of hydrochloric acid it will form H+ ions and Cl- ions. For this example almost all of the HCl will dissociate into ions however with a weak acid such as ethanoic acid only about 0.3% of the acid is dissociated into ions. The action of acids disassociating creates energy and therefore the stronger the acid the more energy.EvaluationIf it was possible for me to repeat this experiment again I would use a much more accurate measuring device. I would use a computer to measure the amount of acid added to the mixture so that the correct amount is used. I would also have the calorimeter on a machine that would constantly shake it so that when the acid is added it is thoroughly mixed with the alkali. For the temperature I would use a computer to continuously record the temperature so any change is noted and I would conduct the experiment in a temperature controlled environment so factors like wind or humidity could not affect the temperature. Because of the equipment available it was not possible to use a lid effectively so if the experiment was repeated I would also use one of these. To keep the insulation of the heat to a maximum I would use a more effective insulating material than the one the calorimeter was made of to make the results more accurate.The method I used did not include any repetition of experiments due to the time restrictions. To improve the accuracy I would do ea ch experiment 5 times then take an average leading to more accurate results.There were many problems encountered in this experiment and it is reflected in some of our results. One of our results had an error of 30%. This could be due to many reasons. On the graphs it shows the acid being added in 1cm3 amounts yet this was for ease of presentation. The amounts added were not always the specified amount and this resulted in the time for the acid to be added was increased or decreased. This could lead to the results being anomalous.Another reason for anomalous results occurring could be human error in the measurement of temperature or amounts of liquid. This could lead to the accuracy of results being affected. Due to the nature of the school laboratory it is possible for the solutions used to become contaminated and the pH to become changed. This could also have altered the results for my experiment. Apart from these possibilities I believe that the test I conducted was a fair one and complied with the statements I made in my plan.I believe that if I carried out the work stated above I would be more confidant of my conclusions. This is because the results ascertained from the above procedures would be a great deal more accurate than the method I used in my experiment.

The Effects of Computers to the Students Essays

The Effects of Computers to the Students Essays The Effects of Computers to the Students Essay The Effects of Computers to the Students Essay TABLE OF CONTENTS Chapter I Introduction . . . . . . . . . . . 1 Importance of the Problem . . . . . . . . . . 2 Statement of the problem . . . . . . . . . . 3 Hypothesis . . . . . . . . . . 4 Scope and Delimitation of the study . . . . . . . . . . 5 Definition of terms. . . . . . . . . . 6 Chapter II Review of Related Literature Chapter III Research Mythology Sources of Data Chapter IV Introduction, Analysis, Interpretation of Data Tabulation Chapter V Conclusion and recommendation Sample Questionnaire ABSTRACT This Paper Reviews Aims to introduce computer games and what This topic is all about. For parents, teachers and specially students who is Graduating to understand the reality effect of this in our daily life and to our Studies. There’s a review being conducted based on some sub question From a certain respondent and observation to determined the amount of Population being involved on computer games that will give us figure of 60-70 percent of the totally population in specific area of Habay bacoor has Been into computer games and some of them get engaged or addicted on it Those person can’t live a day without playing that certain games. In this Studies show as well the negative and positive side of this topic will Help us to know. Negative of this love games more than anything else, Like study forget about family, being so much engaged that end into a not So much good result. On the other hand of positive is giving more Information that will be really helpful in hand of knowledge. CHAPTER I INTRODUCTION Computer games in the information systems industry account for over seven billion dollars in sales in 2003 and are a pivotal component in driving both the software and hardware portions of the industry. Entertainment Software Association, 2003). Computer games are quickly taking a chuck of total dollars in the entertainment industry and some say will emerge with Hollywood to create a more interactive entertaining experience for the consumer. In this paper we will be discussion some brief history of games, how they are currently being developed in regards to software, where games are heading in the future, and how the y currently are being used today in other aspects of life. A History of Games The beginning According to many sources, the idea of the video game came about between 1949 and 951, From Space war to Tournament The history of computer games mistakenly termed videogames probably started in 1962. The early programmers and game designers came up with ideas which have been taken over by the industry and have nowadays become cultural stereotypes. Game types like combat games, strategy, simulation or dungeons and dragons were early 60ies inventions but they are still alive today and probably more vital than ever. Having a look at the old predecessors of todays Play station and Dreamcast games might explain why certain stereotypes are so persistent. Comparing early games with todays programmers also shows the technological progress achieved during the last 4 decades. It seems that the gaming industry and game technology nowadays challenges the complete computer industry in becoming the key industrial branch. Also check the webpages referring to computer games and computer games development: A Short Survey on the History of Computer Games Autumn 1961 Â   Â   Â   Digital Equipment Corp. delivers a PDP-1 computer to the MIT in Cambridge, Mass. This was the first computer equipped with a cathode ray tube monitor and a keyboard. DEC expected the MIT scientists to develop scientific programmes with the machine they donated, yet two scientists programmed an application which is said to have been the first computer game ever. 1962 Â   Â   Â   Â   Â   Stephen Russell, Peter Samson, Dan Edwards, and Martin Grates realized SPACEWAR, a shoot-up game with animated spaceship icons on a black and white monitor. Two users could shoot the other players spaceships in IMPORTANT OF THE STUDY Computer games is have a good benefits and effect to the Benefits of Computer Games Recently, in this modern world that we live in, through the course of the improvement of echnology, computer games became very popular among the youth. Whether we like it or not, computer games greatly influences our society today. Computer games become a part of peoples lives. Almost everyone has been exposed to some kind of computer game – be it role playing games, puzzle games, action games played on a console, a personal computer, or a h andheld device. Because of this sudden interest in computer games, concerns about its effects, may it be positive or negative, arise. Being in a modern world, we naturally question these things. Is it a safe practice to play these games? Will it bring any good? Although many people think that it is unhealthy to play computer games, I believe that, in moderation, computer games can be beneficial in many ways such as in leisure and experience, learning, as well as improving our cognitive, logical, and managerial skills. First of all, video games can be considered as naturally alluring because of its aesthetic images and the realistic experiences that comes with it. As Poole said, video games, especially in these modern times, have very detailed audio-visual effects, usually presenting a simulated fantasy orld that appears to be close to reality (qtd. in Mitchel and Savill-Smith 17). Truly, computer games improved visually and became more realistic these past few years. These fantasy worlds are commonly found in simulation games, which is very useful for learning because it allows players to experience things that might be impossible or too expensive (Mitchell and Seville-Smith 20). Because of this, video games can be l iberating by allowing people to do things they cannot normally do. Effects of Computer Games Experts fear computer consoles such as the Nintendo Way harm child development Children should be banned from playing computer games until the age of seven because the technology is rewiring their brains, it is claimed. Bombardment of the senses with fast-pace action games is said to be causing a shortening of attention span, harming the ability to learn. The concerns emerged as technology industry experts gathered at a special summit discussing the development of children, held yesterday at the Consumer Electronics Show in Las Vegas. Educational psychologist Jane Healy said research indicated that computer games fuelled he development of basic flight or fight instincts rather than considered reasoning. STATEMENT OF THE PROBLEM A. Reasons for undertaking Research. It is known that we are living in technological era. The computers became irreplaceable tool in everyday life of almost each person. The adult users generally use it for business purposes while youngsters for computer games. Computers became the part of our life and very important component in many sp heres of modern life. So it is somehow influences on people. One of the spheres of the life is leisure. And nowadays majority of young people pend their leisure playing computer games, surfing through the internet. Computer games have become one of the favorite time-spending of young people all ages, and even some adults. With permanent development of computer technology the quantity of people using computer either for working purposes or entertainment purposes is increasing speedily. One of the reasons of acquiring computers and computer games by busy parents for their children is providing playing leisure for them. But some parents don’t realize that computer games not only develop child’s mind, logic (what is positive influence) but has negative affects. Computer games industry is evaluated in two ways. On the one hand it is associated with admiration of computers abilities, on the other hand with dangerous influence on teenagers’ psychology and health. HYPOTHESIS In my opinion Computer games grows aggressively and somehow Good for some of people but Sometimes not good for some because if were looking on the Negative side of this topic it will be So addicting for some that will be really negative if you consider Our self / your self to be addiction This on the brighter side of this topic computer games can be Helpful and educational if you know ow to select the right computer games that you know it can help You there’s a lot of educational Games that has been established by a lot wonderful people who Really wants to make computer games Games a worth do can give pleasure and at the same time can Educate you somehow. SCOPE AND DELIMITION OF THE STUDY This study is directly for young individuals especially students like Us who has the priority too study extensively to finish our studies And yet getting pleasure from playing computer games especially On our lazy days specifically weekends. Most of us now days Knows a lot of computer games and we often play specifically In front of a computer, most of us have their computers at home But some of us don’t so it’s a tend to play outside what we usually Call it a computer shop admit it or not relieve us from some stress That we got from a 5 days studies of different subject 8 hours a day And doing homework and project as well I take day of observation On our own computer shop and most of our clients us really Spending a lot of time for games specially male client. CHAPTER II REVIEW OF RELATED LITERATURE This chapter discuss the result of the review of the prevents Literatures that has been written regarding the impact of computer games in graduating students. Various observation and theoretical activities has been done for this review which will be related to the main research of the topic. The Purpose of this review is for us to discover the conclusions were of prior to some effects of computer games to specific students. That falls on teenagers and adolescent category CHAPTER III RESEARCH AND METHOLOGY SOURCE OF DATA In this study I used my very own source in doing my research for my parents Have a computer shop where in can do my observation and ask some few Question with out regular clients which will be really helpful in making Helpful making this study and I also visit some other computer shop to also Observe population composition of that computer shop that visited and I can Say that we have the same population Males are most fond on computer Games there also females but it doesn’t reach to the count of males who Are really into computer games. And I also conduct a little survey to some Unrelated individuals make this study a worth to discuss and be realized By most of us specially were students in this way that did we can specially Determined the effects of computer games us where if it’s Negative or Positive CHAPTER IV INTRODUCTION, ANALYSIS, INTERPRETATION OF DATA TABULATION INTRODUCTION The research finding on computer games will discussed in the research Conclusion And recommendation for future research will also discussed In this section out of 40 male respondents, 80% ( 20 respondent) use the Computer for more 20 hours a week ( more than 4 hours per day ) this Percentage bigger compared to those who use the computer for least 2 hours Per day ( 15% of the respondents ) and at least 3 hours per day (30% of pic] Blue 80% more than 20 hrs Red 20% 7 hrs- 20 White 1 hrs – 7 hrs COMPUTER GAMES All The respondents use the computer for computer games . the Following Graph show the respondent distribution based on the hours The speed on using computer for games Graph 2. distribution of respondent on the computer use For games per week [pic] Blue 1 hrs – 7 Red 7 hrs – 14 hrs White more th an 20 hrs Now the larger faction of the respondents are inclined to Computer games and spend more than 20 hours of computer use per week ANALYSIS The research was conducted form two computer shop here Is bacoor under observation from those 2 different computer shop 60 to 70 % of the total population of those computer shop were Studies probably from school and most of them were males on the Same age as I have or earlier age [pic] Red 75 % Blue 60% CHAPTER V CONCLUSION AND RECOMMENDATION CONCLUSION Learners are among individual specifically graduating students Youngsters or teenagers who play computer games mostly on a daily Basis. This shows that the impact of computer games becomes more board Base on the studies and observation been conducted where in revealed Who are the most computer players how long do they speed to play Computer games the effect. In this study it also highlight the impact of the Computer game in life of each individual involved in this study RECOMMENDATION FOR FUTURE STUDY / RESEARCH This study been researched by means of question and observation For this topic. This research has has been limited in bacoor area (Habay) you Can also do further research and observation by visiting some other place and See if they also have the same situation. I recommend to the same Methology that I did for more effective realization of the topic

Final exam for history who built america Research Paper

Final exam for history who built america - Research Paper Example Each ad is an effort to influence and persuade voters that a certain candidate would be best for them and offer them the best chance not only for world peace but for personal success and fulfillment. The ads try to humanize the candidates and show them as authoritative and sincere. As the years pass, we see the ads and techniques becoming more sophisticated. We see how the candidates become smoother and more polished in their delivery. The public has become more knowledgeable about advertising and advertisers must be ahead of the game. The ads begin with President Eisenhower explaining that he will bring peace to the U.S. These ads are very simple and lacking in many modern techniques. Eisenhower appears to be reading obviously from a script. A decade later, Johnson's presidential ads are much better. They tell a story beginning in November 1963 in Dallas and continuing to 1964. The narrative describes how Johnson has risen to the occasion. It emphasizes continuity. Carter's ads are still more evolved. They feature music and lots of separate shots. They use keyword such as competence and change in order to underscore his appeal against the incumbent Ford. They explain a little bit about him and show him communicating with ordinary people. In the 1990s, political advertising really came into its own.

Critical Analysis Essay Example | Topics and Well Written Essays - 750 words - 2

Critical Analysis - Essay Example 3) and where characters encounter varied challenges due to power play and control. Likewise, there were presence of discreet or imposed relational partners that added drama and provided appropriate applications to interpersonal needs theory of inclusion, control, and intimacy. The mini-series was presented in the form of eight parts and was actually noted to be a sequel to another of Ken Follet’s novel, entitled â€Å"The Pillars of the Earth† (Lloyd, 2012). Due to the length and intricacies of relationships as portrayed by numerous characters, the current discourse would focus on relationships and interpersonal communication applications one of the main characters, Caris. As a wool merchant’s daughter, Caris went through exciting and challenging experiences ranging from witnessing the untimely demise of her mother, who unknowingly was secretly murdered by her aunt, Petranilla. Her interest in treating the sick was enhanced when she became the apprentice of a wom an, Mattie, who practiced alternative medicine. However, since Mattie’s talent apparently jeopardizes the town’s official healer and priest, she was charged with the crime of witchcraft and was sentenced to be hanged in public. Later, Caris suffered the same fate from the hands of her cousin, Godwyn, then Prior; and was just saved in due time by the town’s Prioress who testified that since she was to become a nun, she could not be subjected to the fate of hanging. Therefore, Caris had to sacrifice her love for Merthin until such time that her duty as a nun, eventual Prioress, and healer were all completed. In the process, she became a good healer, and was even assumed the role of a prioress in times when sickness and plague besieged their town. The applications of the interpersonal communication theory or social theory were exhibited in various situations in the series. As noted â€Å"as humans we have a range of social needs that we satisfy by communicating wi th others. The Social Needs theory points out that there are 3 basic social needs: (1) affection - to express and receive love; (2) inclusion - to be social, to be in the company of others; (3) control -to have influence† (Bergstrom, 2005, par. 1). The social need of inclusion was manifested through Caris’ being accepted in the convent as a nun, to save her from death. Likewise, this inclusion was also exemplified through the acceptance of the king, who disguised himself as a monk and was allegedly accepted warmly in the monastery and in the Kingsbridge community. Concurrently, the social need of control was clearly exemplified in the mini-series through the power that was vested upon the monarchy. It was apparent that if the ruler, in this situation, an evil queen, was most concerned of her selfish interests rather than the good of the people, the townsfolk suffered immensely through justice not being served equitably or fairly. It was during this time that it was exhi bited that autocratic power and authoritarian leadership through the order of the king, the queen, or their authorized cohorts could subject people to hanging and death without the need for a just trial. There was evidently much control through the power that was centralized on the monarchy and also from the priory, where the prior was vested with the authority to decide things on himself. For instance, the prior could charge people suspected of witchcraft and immediately, these haplessly

I must write a after action review (AAR) based off my deployment to Essay - 1

I must write a after action review (AAR) based off my deployment to Afghanistan - Essay Example My deputy and I often disagreed due to differing opinions concerning the point at which a product was supposed to enter sustainment phases. My deputy held that the personnel within the army unit would be ready to handle new equipment on their own soon after their training; however, this perspective did not consider other factors. For instance, this view overlooked the fact that we were fielding new equipment to soldiers with no experience in how they operation during wartime; similarly. This view was blind to the fact that Soldiers rotate to other FOBs (forward operation bases) or COPs and that they may get hurt or whatever the case me be, due to their inexperience with handling new equipment. Contrariwise, I believed in continuous retraining, which is why I had my contractors provide multiple training classes to different personnel of the same unit. I stressed the importance of the acquisition community taking responsibility to support the war fighter. I believed it was our obligati on as the acquisition community to support the war fighter regardless of the number of training events. Therefore, it would take for every unit, army or marines to be capable of handling the generators on their own. The soldiers had to be thoroughly trained to ensure they were equipped with the competence needed to operate the new equipment in the field, even if it meant doing it repeatedly with different personnel. In that case, I supported the training for the army personnel for as long as it was needed, to ensure the war fighters were well prepared to operate our new generators. The command and Control (C2) issue cropped up as well, in the course of my deployment in Afghanistan; as expected in combat zones, where orders are given to carry out missions, there was always a strict chain of command that had to be observed at all times. A chain of command does establish clear lines or boundaries for officers in the field, who must act in accordance

Research on Immunology in Pregnancy

Research on Immunology in Pregnancy Investigative Review Nichole Gale The systems controlling the implantation and acceptance of the genetically and immunologically foreign fetus within the maternal body have often been likened to that of an organ transplant, or the growth of a cancerous tumour. The fetus is ‘like a transplanted kidney’, in the way that it is ‘genetically different from the host’ and ‘must evade immune defences to avoid rejection’ (Quinn 1999). The fetus inherits ‘foreign paternally derived histocompatibility genes’, meaning that ‘there is close contact between two genetically disparate individuals’ within the maternal body (Warshaw 1983, p63). Thus, the fetus is often referred to as an allograft, an allograft being a ‘graft transplanted by an individual that is not genetically identical, but of the same species’ (Marieb 1998, p789). The subject of fetus acceptance and tolerance within the maternal body has triggered great interest and controversy, and the sy stems that allow the acceptance of the fetus are complex and varying. Internal gestation has involved ‘a wide range of adaptations of animals for retention of young within the body of the parent’ (Warshaw 1983, p63). The human immune system includes many ‘cellular patterns that constantly exchange information’ to provide the body with the ability to ‘recognise foreignness or â€Å"non-self† in the form of antigens that enter our body’ (Warshaw 1983, p200). The recognition of antigens spark the inflammatory response, which must act with ‘minimum damage to the host’, in order to ‘eliminate the intruder’ (Warshaw 1983, p200). ‘Antigens are expressed by early human embryonic tissue’ (Loke 1978, p5), so it could be expected that the early human embryo would trigger an inflammatory response to rid the mother’s body of the ‘foreign body’. The exposure to non-self paternal antigens on the fetus ‘requires the adaptation of the maternal immune system to prevent the rejection of the allogeneic fetus without compromising the ability of the mother to fend off infection’ (Koch Platt 2003). The immune system consists of an innate (humoral) and an adaptive (cellular) component, in order to combat potential pathogens. It has been suggested that the main immune response triggered by the fetus is the adaptive response, where there is antigen representation, followed by response instruction by Helper T cells (Quinn 1999). In normal pregnancy, progesterone suppresses the humoral response. This has been used to explain why some autoimmune diseases, such as rheumatoid arthritis that are under humoral effect, often improve during pregnancy (Quinn 1999). Early work on immunological tolerance, conducted by Medawar, has been the foundation of further studies regarding the paradox of pregnancy. Medawar proposed three mechanisms that might together act to allow immune protection of the fetus. Two of Medawar’s earlier suggested mechanisms have since been proved to not actually ‘pertain during pregnancy’ (Aluvihare, Kallikourdis Betz 2004). The first hypothesis was that there was ‘segregation of the fetal and maternal circulations’, or that ‘a barrier might form between the mother and fetus, preventing exposure of the maternal immune system to allogeneic antigens expressed on fetal tissue’, leading to immunological ignorance (Koch Platt 2003). Medwar’s second hypothesis referred to the immunological immaturity of fetal tissue, and this allogenic immaturity acting to suppress the ‘expression of antigens that the maternal immune system might recognise as foreign and target for dest ruction’ (Koch Platt 2003). More recent research has tended to focus on Medwar’s third hypothesis, ‘that the maternal immune system somehow ignores potentially immunogenic fetal tissue’ (Aluvihare, Kallikourdis Betz 2004). Leading from this, there has also been much focus on ‘the means of inducing immune tolerance, the emergence of T cell suppression in mediating peripheral tolerance, the mechanisms mediating matererno-fetal tolerance and the role played by regulatory T cells in mouse and human pregnancy’ (Aluvihare, Kallikourdis Betz 2005). Koch and Platt (2003) suggest overlapping mechanisms such as ‘the formation of an anatomical barrier between mother and fetus, lack of maternal immune responsiveness, and a lack of expression of allogenic molecules by the fetus’ to account for the lack of fetal rejection. These mechanisms can help in beginning to understand how rejection is avoided, yet do not ‘completely explain how the fetus evades the maternal immune system’ (Koch Platt 2003). Harding and Bocking (2001, p238) state that it was originally proposed that the maternal-fetal interface was perhaps ‘an immunologically privileged site’, or that there was a ‘generalised suppression of maternal immune response’. Recent studies have challenged earlier theories such as these, and it has since been found that not only is there actual recognition of fetal alloantigens by the mother’s immune system, but that her body also responds to them. Fetal cells can be detected in maternal circulation, and ‘fetal tissue expresses MHC class I and class II and is antigenically mature’ (Aluvihare, Kallikourdis Betz 2004). MHC are major histocompatibility complex proteins coded for by genes. Class I are found on virtually all body cells, whereas class II displayed only by cells that act in immune response (Marieb 1998). The understanding of the immune events and mechanisms occurring at the maternal-fetal interface are likely to help in the understanding of the ability of the fetus to survive within the maternal body. Since Medawar’s proposed hypotheses, much focus has continued on fetal immune evasion mechanisms. As well as the three mechanisms above, suggested by Medawar, Koch and Platt (2003) explore a fourth mechanism, site-specific suppression. This refers to ‘local suppression of maternal immune responses at the maternal-fetal interface’ (Koch Platt 2003). ‘Localised suppression at the maternal-fetal interface during pregnancy negates the need for systemic immunosuppression which could threaten the well-being of the mother’ (Koch Platt 2003). Earlier studies suggested that trophoblast acted simply as a barrier between the mother and fetus, but it now seems that perhaps that it could have ‘diverse immunoregulatory properties controlling immune recognition, activation, and effector functions’ (Koch Platt 2003). It has been proposed by various studies that T cells play a major role in sustaining pregnancy. T cells are lymphocytes that mediate cellular immunity. ‘T cells with regulatory functions are potent suppressors of T cell responses and can protect tissues from T cell mediated destruction’ (Mellor Munn 2004). Observations in experimental pregnant mice have shown that while pregnant, they tend to ‘overproduce a kind of T cell that reins in other immune cells that might target the fetus’ (Seppa 2004). In one study, conducted by immunologist Betz (Seppa 2004) it was found that ‘pregnant mice have double to triple the number of CD4+ CD25+ T cells, also called regulatory T cells, in their blood, spleen, and lymph tissue as do female mice that are not pregnant’. It has also been shown that in humans, levels of circulating CD4+ and CD25+ cells ‘increases progressively at each stage in human pregnancy starting from the first trimester’ (Mello r Munn 2004). It has been ‘demonstrated that Tregs (T regulator cells) have a key role in regulating maternal effector T cell responses to fetal alloantigens’ as maternal effector T cells seem to ‘pose a potentially lethal threat to the developing fetus in the absence of regulatory function mediated by maternal Tregs’ (Mellor Munn 2004). It has also been speculated ‘that hormonal changes during pregnancy might provide one explanation for enhanced maternal Treg development during fetal gestation because pregnancy-associated hormones, such as progesterones, promote immunosuppression’ (Mellor Munn 2004). In regard to the suppression of maternal immunity, it is still ‘unclear if Tregs directly or indirectly inhibit effector T cell responses to fetal alloantigens’ (Mellor Munn 2004). To further test the cells’ effect on pregnancy, 30 female mice were mated with males. 15 out of the 30 mice had fully functioning immune systems, whilst the other 15 mice lacked the regulatory T cells. While a slightly higher than normal number of healthy female mice became pregnant, none of the mice lacking T cells were able to become pregnant. It seems that the role of T cells remains unclear, but that further understanding ‘of the role of regulatory T cells might also lead to new treatments for suppressing rejection of transplanted organs and inhibiting autoimmune reactions, in which a persons immune cells attack his or her own tissues’ (Seppa 2004). Mellor and Munn (2004) also suggest that the revelation that ‘maternal Tregs might help protect the developing fetus’ will have various implications, not only the possibility of offering alternative therapies to suppress immunity, but also possibilities for ‘improving pregnancy success rates in p atients with problematic pregnancies’. Again, the effect of T cells on autoimmune diseases is referred to by Mellor and Munn (2004), ‘increased systemic Treg function might explain why some autoimmune syndromes, such as rheumatoid arthritis, go into remission during pregnancy’. There has also been some discussion on the role of macrophages as immunoregulators of pregnancy. It has been claimed that most attention has focused on immune tolerance to the invading trophoblast and fetus, but Mor and Abrahams (2003) suggest that it is also important to ‘consider the function of the maternal immune system in the promotion of implantation and maintenance of pregnancy’. During implantation, apoptosis is necessary for ‘tissue remodelling of the maternal decidua and invasion of the developing embryo’ (Mor Abrahams 2003). It has been sited that apoptosis is active in the ‘trophoblast layer of placentas from uncomplicated pregnancies throughout gestation, suggesting that there is a constant cell turnover at the site of implantation necessary for the appropriate growth and function of the placenta’ (Mor Abrahams 2003). During implantation and invasion, it appears that a large number of macrophages are present in the maternal decidu a and in tissues close in proximity to the placenta. Originally it was thought the large numbers of macrophages were ‘to represent an immune response against the invading trophoblast’. Mor and Abrahams (2003) propose that this may not be the case, and that ‘macrophage engulfment of apoptotic cells prevents the release of potentially pro-inflammatory and pro-immunogenic intracellular contents’. Trophoblast cells carry proteins that are antigenically foreign to the maternal immune system. If these proteins are released as a result of cell death, it could initiate or accelerate immunological responses, ‘with lethal consequences for the fetus’ (Mor Abrahams 2003). Therefore, the appropriate removal of the intracellular components by macrophages may be critical for the prevention of fetal rejection. Mor and Abrahams (2003) conclude that the ‘field of apoptotic cell clearance is beginning to flourish, and many questions remain unanswered’. There is not just one mechanism involved in the immune regulation of pregnancy, but ‘multiple, diverse mechanisms that are likely sequential during gestation’ (Koch Platt 2003). As humans have a much longer gestation period, and a more invasive placental anatomy, it is sometimes difficult to test in laboratory animals and apply results to humans, as there may be different mechanisms. But it is believed that mechanisms involved with the fetus can be utilised in the studies of rejection following transplantation. As Koch and Platt (2003) suggest, ‘knowledge of the immunoregulatory mechanisms of both the fetus and stem cells will help immunologists understand general mechanisms of tolerance and immune evasion, and will prove invaluable in the fields of organ and cellular transplantation’. It has been suggested that both studies in stem cells and fetal rejection can benefit each other and help in understanding of systems involved. Pregnancy has also been said to have overall effects on the mother’s immune system and maternal defence against organisms. According to Creasy and Resnik (2004, p103) ‘numerous reports indicate that pregnant women have increased susceptibility to a variety of infections’. It is said that ‘there appears to be a trend toward increased susceptibility to viral infections, consistent with suppressed cell-mediated immunity and a relative decrease in Th1 (humoral/innate) responses during pregnancy’ (Creasy Resnik 2004, p103). However, it also added that ‘more recent carefully analysed data do not indicate that maternal immunity is substantially impaired, and most pregnant women are able to adequately respond to most infectious diseases’ (Creasy Resnik 2004, p103). Harding and Bocking (2001, p238) also claim that most studies tend to suggest that ‘maternal cell-mediated immunity is unchanged during pregnancy’. According to some experts, infertility, recurrent miscarriage, premature delivery and preeclampsia may all be linked to immunological abnormalities. It could be that some of these problems are due to ‘defective generation of Tregs during pregnancy’ (Mellor Munn 2004). It is possible that methods involving in vitro expansion of Tregs could help in treating spontaneous immune disease syndromes. Koch and Platt (2003) also suggest that both adult and embryonic stem cells might use mechanisms similar to the fetus in avoiding rejection. ‘Future discoveries in the field of reproductive immunology will help us understand not only immune regulation during pregnancy, but also how immune responses towards organ and cellular transplants might be controlled’ (Koch Platt 2003). References: Aluvihare, V., Kallikourdis, M., and Betz, A. 2004 ‘Tolerance, suppression and the fetal allograft’. Journal of Molecular Medicine. [Online], vol. 83, no. 2, pp 88-96. Available from: Medline. [11 October 2005]. Creasy R. Resnik R. (ed.) 2004. Maternal-Fetal Medicine, 5th edn., Saunders, Philadelphia. Harding, R., Bocking, A., (ed.) 2001. Fetal Growth and Development, Cambridge University Press, Cambridge. Koch, C. Platt, J. 2003 ‘Natural Mechanisms for evading graft rejection: the fetus as an allograft’, Springer Seminars in Immunopathology, [Online], vol. 25, no. 2, pp 95-117. Available from SpringerLink. [7 October 2005]. Loke, Y., 1978. Immunology and Immunopathology of the Human Fetal-Maternal Interaction, Elsevier Horth-Holland Biomedical Press, New York. Marieb. E., 1998. Human Anatomy and Physiology, 4th edn., Addison Wesley Longman, California. Mellor, A. Munn, D. 2004 ‘Policing pregnancy: Tregs help keep the peace’, Trends in Immunology. [Online], vol. 25, no.11, pp 563-565. Available from: Medline. [10 October 2005]. Mor, G. Abrahams, V. 2003 ‘Potential role of macrophages as immunoregulators of pregnancy’, Reproductive Biology and Endocrinology. [Online], vol. 119, no.1. Available from Medline. [11 October 2005]. Quinn, T. (1999), Immunology in Pregnancy; The Fetal Allograft, [Online], SIU Medical Library. Available from: http://www.siumed.edu/lib/ref/ppt/immunpreg/> [20 September 2005]. Seppa, N. 2004 ‘Some T cells may be a fetus’ best friend’, Science News, [Online], vol. 165, no. 8, p125. Available from: Proquest. [11 October 2005]. Warshaw, J. (ed.) 1983, The Biological Basis of Reproductive and Developmental Medicine, Elsevier Science Publishing Co., New York.