Plant Layout

LAYOUT Facility layout is an arrangement of different aspects of manufacturing in an appropriate manner as to achieve desired production results. Facility layout considers available space, final product, safety of users and facility and convenience of operations. An effective facility layout ensures that there is a smooth and steady flow of production material, equipment and manpower at minimum cost. Facility layout looks at physical allocation of space for economic activity in the plant. Therefore, main objective of the facility layout planning is to design effective workflow as to make equipment and workers more productive. Facility Layout Objective A model facility layout should be able to provide an ideal relationship between raw material, equipment, manpower and final product at minimal cost under safe and comfortable environment. An efficient and effective facility layout can cover following objectives: * To provide optimum space to organize equipment and facilitate movement of goods and to create safe and comfortable work environment. * To promote order in production towards a single objective * To reduce movement of workers, raw material and equipment * To promote safety of plant as well as its workers To facilitate extension or change in the layout to accommodate new product line or technology upgradation * To increase production capacity of the organization An organization can achieve the above-mentioned objective by ensuring the following: * Better training of the workers and supervisors. * Creating awareness about of health hazard and safety standards * Optimum utilization of workforce and equipment * Encouraging empowerment and reducing administrative and other indirect work Factors affecting Facility Layout Facility layout designing and implementation is influenced by various factors.These factors vary from industry to industry but influence facility layout. These factors are as follows: * The design of the facility layout should consider overall objectives set by the organization. * Optimum space needs to be allocated for process and technology. * A proper safety measure as to avoid mishaps. * Overall management policies and future direction of the organization Design of Facility Layout Principles which drive design of the facility layout need to take into the consideration objective of facility layout, factors influencing facility layout and constraints of facility layout.These principles are as follows: * Flexibility: Facility layout should provide flexibility for expansion or modification. * Space Utilization: Optimum space utilization reduces the time in material and people movement and promotes safety. * Capital: Capital investment should be minimal when finalizing different models of facility layout. Design Layout Techniques There are three techniques of design layout, and they are as follows: 1. Two or Three Dimensional Templates: This technique utilizes development of a scaled-down model based on approved drawings. . Sequence Analysis: This technique utilizes computer technology in designing the facility layout by sequencing out all activities and then arranging them in circular or in a straight line. 3. Line Balancing: This kind of technique is used for assembly line. Types of Facility Layout There are six types of facility layout, and they are as follows: * Line Layout * Functional Layout * Fixed Position Layout * Cellular Technology Layout * Combined Layout, and * Computerized Relative Allocation of Facility Technique

Cardinal & Ordinal Approach in Economics

Cardinal utility analysisHuman wants are unlimited and they are of different strength. The means at the disposal of a man are not only scarce but they have alternative uses. As a result of scarcity of resources, the consumer cannot satisfy all his wants. He has to choose as to which want is to be satisfied first and which afterward if the resources permit. The consumer is confronted in making a choice. For example, a man’ is thirsty. He goes to the market and satisfies his thirst by purchasing coca’-cola instead of tea. We are here to examine the economic forces which. Make him purchase a particular commodity. The answer is simple. The consumer buys a commodity because it gives him satisfaction. In technical term, a consumer purchases a commodity because it has utility† for him. We now examine the tools which are used in the analysis of. Consumer behavior.Concept of utilityJevons (1835-1882) was the first economist who introduced the concept of utility in economic s. According to him ‘utility’ is the basis on which the demand of an individual for a commodity depends ‘Utility’ is defined as the power of a commodity or service to satisfy human want. Utility thus is the satisfaction which is derived by the consumer by consuming the goods. For example, cloth has a utility for us because we can wear it. Pen has a utility for a person who can write with it. The utility is subjective in nature. It differs from person to person. The utility of a bottle of wine is zero for a person who is non-drinker while it has a very high utility for a drinker.Here it may be noted that the term ‘utility’ may not be confused with pleasure or awfulness which a commodity gives to an individual. Utility is a subjective satisfaction which consumer gets from .consuming any good or service. For example,Poison is injurious to health but it gives subjective satisfaction to a person who wishes to die. We can say that utility is value ne utral.

Ethics of Engineering Essay

Risk can be defined in many different versions basing on the specified use and situational context. It can simply means the future negative circumstances that can be prevented or mitigated, rather than day to day that calls for immediate attention. When it comes to risk management, the word hazard can be used to define a situation that would lead to harm while the word risk would mean a probability of anything occurring. This concept was applied at planning of delta works in the nineteenth century, which is a flood preventing project in western country. The type of risk analysis is now common in sites like chemical industry and nuclear power. Determining engineering risk is somewhere hard especially in industries where there is production of toxic materials. The way forward to measure individual life cost caused by the loss differs basing on the aim or purpose. Most measures entail what individuals are able to give to insure against death (National Academy of Engineering & National Academies Press (US), 2004). Categories of risk -financial risk; is mostly termed as the unplanned variability of returns which covers bad-than-unplanned as well as good-than-desired returns. Basing on statistics risk is always placed to the probability of a number of outcomes that are mostly undesirable (Morse & Babcock, 2009). Often the probability of the event and various assessment of its perceived harm need to be joined into a believable outcome, which joins a group of risk, regret and pay probabilities in a desired value for that same outcome. Risk is therefore assessed as a task of three variables namely – the probability that there might be a negative warning, the presence of vulnerability and finally potential improvement in business. The first two probabilities are joined together and sometimes called likelihood, if any of the named variables above almost results to zero, the whole risk results to zero. Risk can further be defined as a state of lacking complete certainty where a number of possibilities entail a loss or various unexpected outcome. Measurement of risk; a group of possibilities with which each has a quantified probability and quantified losses From the text above it is vital for one to have uncertainty with no risk but not have risk without uncertainty. People can be uncertain concerning who will be the winner in a contest but unless they hold individuals stake in it, they hold no risk (Martin & Schinzinger, 2005). If people bet some finances on the results of the contest, then it is true they have a risk. In this similar occurrences there are different outcome. The value of uncertainty only defines the probabilities kept for outcomes, as the calculation of risk calls for the two outcomes that is probability and quantified (National Academy of Engineering & National Academies Press (US), 2004). Insurance and heath risk – insurance is a type of risk lowering investment whereby the customer gives some agreed amount to be safer incase a negative issue arises. In this way, the customer will be so sure a loss has not occurred. Buying a lottery ticket is a high-risk investment with a possibility of minimal reward but with a high chance of getting a loss (Moriarty, 2008). Banking some funds at a specific rate of interest is also taking a risk although the return is less but guaranteed. Some risks like in individual’s health could be minimized through primary prevention habits that lowers early occurrence of diseases or by secondary avoidance habits once an individual has been exposed to early symptoms and signs that could be a risk factor. Tertiary avoidance lowers the negative outcome of a disease that is already established by minimizing illness- associated complication and restoring the functions. Every medical professional needs clear discussions about risk factors with an individual client to acquire informed consent concerning tertiary and secondary avoidance efforts however the entire medical health efforts in primary avoidance needs education of the public group at risk (Martin & Schinzinger, 2005). In each circumstance, excellent communication concerning any risk factors, predicted results and certainty should differentiate between causal circumstances that need to be reduced and associated circumstances which might be consequences rather than causes (Baura, 2006). Safety It can be defined as a situation of being secure, out of danger injury or risk or in other terms, it means events that call to lower or do away with hazardous situations that can lead to injury of the body. Categories of safety †¢ Occupational safety – it is mainly based with risks in locations where individuals work that is in building and construction, business industries and organizations. †¢ public safety – it deals with hazards in premises, journeys, touring and recreation, and in other various circumstances which is not within the category of occupational safety †¢ Marketing safety – this entails security in purchasing of goods and even in producing. One must be sure the services offered will not lead to a negative outcome (Baura, 2006). On the other hand, the producers themselves should not risk in making a loss for this can cause the closure of a business. †¢ Insurance risk – this avoids a great loss in business or in individuals investment incase an accident or an injury arises, that means the owner is secured. In case of an accident, it is always advisable to analyze the employees’ status of safety measures, which could be affected by outward working environment, attitudes directed to security and accident avoidance work and also leaders’ commitment in security promotion. Such kind of factors could be linked to work stress and risk behavior (Moriarty, 2008). The perceived risk behavior affects negative outcomes like accidents and near misses, while the possibility that discourages improvement in transforming a person’s risk perception towards embracing safety is still not yet clear (Martin & Schinzinger, 2005). Competent verses incompetent A competent engineer is one whose work is recommendable and excellent; he evaluates, assesses and organizes the employees to work with an aim of meeting the company’s goals and objectives. He works under minimal supervision from the seniors, seeks for advice in times of difficulty and consults other professionals to add skills and knowledge (Harris et al 2008). Unlike incompetent engineer who might have no knowledge of his work and his end results after working are disgusting. Maintaining a competent engineer could be challenging unlike the incompetent one. A good engineer has most of the qualification required in his area of assignment; works well to produce excellent results while a good person is generally pleasing and manifests good characters but may be lacking qualifications in his work (National Academy of Engineering & National Academies Press (US), 2004). A person may be competent but lacks good morals this can be evidenced by most of the employers who employ workers on condition to get ‘something’ in return. This is mostly happening in the modern world where most competent individuals have no integrity or character. In conclusion, it is better to risk taking an action despite of the unknown results rather than being safe in a condition whose guaranteed results are negative for example banking money to gain small interest instead of keeping it with you. Reference Baura, G. (2006). Engineering ethics: an industrial perspective. New York: Academic Press. Harris, C. , Pritchard, M. & Rabins, M. (2008). Engineering Ethics: Concepts and Cases, 4th Ed. New York: Cengage Learning. Martin, M. & Schinzinger, R. (2005). Ethics in engineering, 4th Ed. New York: McGraw-Hill Publishers. Moriarty, G. (2008). The engineering project: its nature, ethics, and promise. New York: Penn State Press. Morse, L. & Babcock, D. (2009). Managing Engineering and Technology: An Introduction to Management for Engineers, 5th Ed. New York: Prentice Hall Publishers. National Academy of Engineering & National Academies Press (US). (2004). Emerging technologies and ethical issues in engineering: papers from a workshop, October 14-15, 2003. New York: National Academies Press.

The views and perceptions of students and mentors regarding mentorship Dissertation

The views and perceptions of students and mentors regarding mentorship role - Dissertation Example The shortage of nursing staff has simultaneously reduced the faculty available for mentoring. However as peer mentoring has been found to be a feasible solution to the many challenges by several researchers there is no other option but to enforce practical solutions. The promotion of the concept of peer mentoring provides an overall answer. The stress on education and the burden on the limited number of faculty could be lessened through increasing the opportunity for peer mentoring. Mentorship or preceptorship has become an essential strategy of nursing education for the preparation of nursing students for the profession (Smedley, 2008). Researchers have made suggestions to overcome hurdles and promote peer mentoring. Nurses could mentor other nurses and students could mentor their juniors apart from the usual concept where lecturers and nurse educators mentored nursing students (Dennison, 2007). The mentors were to be supported by other staff and clinical colleagues. Exceptional aca demic and clinical skills determined whether a nurse or nursing student could be a mentor. The vast literature on the subject of mentorship, which kept changing its features, has opened my eyes to this problem of mentorship in nursing needing speedy resolution. The future of nursing, quality care and client satisfaction depended on the ethical practices for assessment of the clinical abilities or skills of a nursing student (Gopee, 2008). The general trend highlights the vital role of the clinical staff nurses in the mentoring of students into competent leaders of the future and custodians of safe and efficient patient care. However the problem that nurses have not fully grasped the significance of their roles... The paper tells that a significant requirement of nurse education was the presence and support of a preceptor who played a key role in the integration and growth of nursing students towards the profession. The benefits of the learning experiences were mutual for both the preceptor and the student nurse. The hospital, the community and mental health centers were the different settings where the guidance of the preceptor had a role in shaping the student nurse for further experiences in the profession. Her observation and supervision enhanced the abilities of the student and equipped them with problem-solving habits. Socialization was the technique that the preceptor used to help the nurse student to notice the link between theory and practice, a great responsibility. The preceptor meanwhile has her own experience of being a successful preceptor adding a new feather in her cap. The preceptor’s selfless attitude in nursing would be emulated by her students and this further instil led in her the power of her additional responsibility and prowess in her profession. The preceptor planned the time management, prioritization of care and delegation of work. Smedley and Penney had advocated a preceptor’s course for registered nurses which improved their skills for preceptorship to produce a learning relationship in their work setting. The mentored nursing students would advance in professional skills, elevating their knowledge and gradually changing their attitudes to the profession through an action-learning process.

Critically evaluate and apply how management and leadership within Essay

Critically evaluate and apply how management and leadership within inter-professional working can improve the quality of care in the healthcare environment - Essay Example Favourable conditions are also being created for the emergence of new occupational groups and for the configuration of new types of nursing techniques and care team. (Department of Health, 2009) In the UK the formal system of mental health nursing work began in the late 18th century with the large-scale construction of institutions dedicated to the segregation of madness (Rogers and Pilgrim, 2001), in which psychiatric nursing emerged as the lead profession. As Scull notes, psychiatrys dominance was linked to the professions successful leadership and management in advancement of claims to possess knowledge of lunacy as a disease with biophysical origins. Echoing the claims made by other branches of medicine at this time, the jurisdiction asserted by mad doctors during the 19th century came to be a wide-ranging one, encompassing the identification of mental disorder and proper management of its cause, natural history and cure (Rogers and Pilgrim, 2001). The social organisation of psychiatry and its autonomy and power were consolidated in the 1840s with the founding of both a professional association and a journal. Particularly long-lasting claims to control areas of work can be secured in the legal arena, and in the same decade psychiatry secured an advancement of its jurisdiction in this sphere with the passing of the 1845 Lunatics Act. This saw the establishment of a medically dominated Lunacy Commission, which, Scull observes, exerted a powerful influence against the running of asylums by lay people. Psychiatry thus secured occupational closure over the work of managing mental illness through effective nursing techniques. A decade later, as Rogers and Pilgrim note, the jurisdiction of British psychiatry was sufficiently secure for an editorial in the Journal of Mental Science (now the British Journal of Psychiatry ) to declare that: insanity is entirely an ailment of the brain. The

Involvement of the Volkswagen Group in Chinese Market Dissertation

Involvement of the Volkswagen Group in Chinese Market - Dissertation Example Industries such as information and technology, automobile, fast food, manufacturing, information technology enables services, etc have been majorly influenced by the globalisation. The companies today have realised the fact that sustained growth is only possible when the company focuses not only on the national market but also international market. The major industry that has been influenced by globalisation is the automobile industry. Automobile industry today is a global industry with the demand for automobiles increasing like never before. There are various reasons for this increase in the demand for automobiles. One reason is the increase in demand for automobiles in the developing countries and countries like China. Chinese and Indian automobile markets have now become the major attraction to many European and American automobile companies. In response to this global demand and also to sustain the growth, major automobile companies have now been concentrating on the emerging markets such as China and India. This research is aimed at analysing the internationalisation of automobile manufacturers. In order to do so Volkswagen and the Chinese market is taken as an example. Volkswagen’s operations in China have increased rapidly since its first interest in it in the 80’s. This research aims to analyse the involvement of Volkswagen in the Chinese market and how it has affected the sales and in-turn the growth of the company globally. The research analyses the various strategies adopted by Volkswagen and how it has been implemented. It also looks into the result of these strategies on the overall success of the company. Also the Chinese market will be analysed in detail. That is, the reason behind the attractiveness of the Chinese market to the global companies and the advantages and disadvantages of doing business in China. This is a research proposal outlining the aims, objectives, methodology of the research. It addresses the important aspects such as relevance of the researc h, recipients of the research, rationale, etc. Research Aim, Questions and Objectives Research Aim Aim of any research is to find measurable and testable data or information that adds to the existing human knowledge. Any research must have a specific aim that needs to be accomplished at the end. The primary aim of current research is to analyse the involvement of the Volkswagen group in the Chinese market and relate it to the overall internationalisation of Automobile manufacturers in general. A secondary aim of this research is to understand the Chinese market with respect to automobile manufacturers. In order to accomplish the above aims of the research, there is a need to formulate specific research questions and research objectives that address the various aspects of the research topic. Research Question Research question is the most important aspect of a research proposal as it addresses the core of what the researcher intends to do. Research questions are vital not only for th e current research but also for further research as it leads to the formulation of new questions this leads to further investigation and research in the topic (Lester & Lester, 2009). A research question directly indicates if the researcher is on the right track to accomplish the aims of the research. A research question needs to be well formulated keeping the aims of the research. A research question should not be too elaborative or too restrictive. The reason for this is that an elaborative question might not be intriguing as it might turn out to be a explanation rather than a question. On the other hand, if the research question i

The establishment of America was long and controversial, but the Research Paper

The establishment of America was long and controversial, but the nation thrived in justice and liberty - Research Paper Example It discusses in detail the urge and the constant struggle of the nation to attain liberty and justice extracting ideas and information from the Voice of Freedom by Eric Foner. The majority of the individuals living in the United States were mainly the farmers and Native Americans (Indians). However, during the time of the exploration most of the European nations migrated to America for trade. The war of the independence initially begins when the different colonies that established in the south and North America because of the migration caused cultural diversity. The demands of the diverse group living in America transformed the meaning of freedom. These groups on their own strived to attain justice and fought for their rights. The peasants fought for their lands and rights, gender discriminations and religious freedom. It is evident during the American Revolution that the demands of equality among the people of America were often question. The peasant and slaves in America were recognized as inferior and had lower socio-economic status in the society. The difference between the privilege of the servants and peasants was embarked to be one of the major iss ues due to which the people of America strived for justice and independence. Hence, â€Å"The liberating Indentured Servant (1784)† was enacted that provided status for the slaves and servants in American Society. Eric states, "a group of respectable New Yorkers proposed to liberate the ship of the African slaves that were brought to America" (Foner 104). These free slaves were provided with a respectable and social status in the society so that they can enjoy their freedom to practice their rights. Previously, Virginia did not have a stable family structure because of the strict rules for the servants in the tobacco field. Browne (1644) States that Virginia remained to be a society with the high number of single men, widows and orphans rather than

Project Portfolio Management Case Study Example | Topics and Well Written Essays - 1500 words

Project Portfolio Management - Case Study Example The constraints of external environmental factors, changes in customer requirements and demographics and the financial and operational constraints would also be considered for the same. The project selection criteria would mainly be based on the continuously shifting needs of the customer groups in this industry in Florida, where the company is mainly located. Also, the strategic objectives of the company like the expansion of the business into new markets like Europe and Alaska, the increase in revenues by 10%, the expansion of customer services and the improvement of the customer satisfaction levels by 15% every year, would also be considered as the main project selection criteria. Apart from these, the cost control objectives of the company including the reduction of operating costs by at least 10% per year and the reduction of warehouse and overhead costs by at least 5% per year would be taken up as key selection criteria for the project portfolio management process. Thus, to ens ure that all these goals are met with, the Enterprise Project Portfolio Management (EPPM) method is selected. The Enterprise Project Portfolio Management (EPPM) method of portfolio management is selected for the company because this technique involves taking up a top down approach that helps to manage all the project intensive resources and activities across the company. This would help to streamline the different business decision units of the company by ensuring better integration of the operational, financial, human resources and corporate strategies of the company. Since, this method is an automated system and does not require manual work; therefore, it would be time and cost effective as well. The EPPM takes up a centralized top down approach of managing the project portfolios which ensures that all levels of employees are actively engaged in the project

Theory of Knowledge Essay Example | Topics and Well Written Essays - 2000 words

Theory of Knowledge - Essay Example This, therefore, leads to justification of our beliefs. Justification is established by the distinction between believing that something is true and between knowing that something is what it is. For instance, for a belief to be justified, it has to be endorsed by some other idea so that it can be dependable or relied upon. More so, the concept supporting it must be believed to be true and lastly, it is significant that we have a substantive or credible and viable reason for us to believe that the idea endorsing our belief is actually real. When all these ideas are put together, it constitutes true and credible knowledge. Additionally, it is important that our knowledge that we acquire be true or real. Truth is the capability of the information acquired being consistent with evident presented and truths about it. Thus, all information is believed to be true and it is known to be true, which in turn makes up credible, reliable knowledge. Rationality is the ability to act using reason i n relation to the facts of reality of certain scenario or situation (Allen 31). Thus, if one is having false knowledge, they are not in a position to act rationally but on the other hand, if they have true and credible knowledge, they will be in a position to act or behave rationally. It is vital to note that it is possible for people to act reasonably or rationality without their knowledge since they posses wrong knowledge. The only way to avoid such kind of situation is that individuals need to reason cautiously about any scenario before they act on it. Immanuel Kant formulated his principles regarding what is right and wrong. He developed a system of three questions he referred to as formulations which an individual need to ask before undertaking any action in order to decide upon ethicality of the action. It is significant for a person to ask himself if the action they are about to partake corresponds to a rule, which should be used universally. It is good to view other people a s our end objective rather than the means to gain personal goals. For Kant, the driving force is a determining factor to what extent can an action be regarded as ethical. This driving force is known as motive. Kant’s objective morality can be well understood from a more precise philosophical vocabulary (Allen 36-7). Although, it is natural that everything in the universe acts in accordance with the law, Kant argues that only rational beings in obedience and respect to the objective principle influenced by practical reason can influence their actions. Human beings have got subjective impulses such as desires and inclinations that may contradict how they reason. According to Kant, human beings hold a significant place in creation and morality can be said to be ultimate commandment of imperative or reason. For instance, objective principle includes acting in accordance with the law and ignoring other agents such as inclinations and desires in making moral judgments. Moral action is not justified if it is done out

Joel Patrick Courtney Essay Example | Topics and Well Written Essays - 1000 words

Joel Patrick Courtney - Essay Example One of four children of working class parents, Courtney grew up in Beaverton, Oregon, near Portland. According to his older sister Dina McBride, he had an â€Å"idyllic† childhood (Tilkin 2009). By the time Courtney was eleven years old, he became involved with drugs and was sent to juvenile detention at 15. His sister also testified, during his trial for the Wilberger murder, that he had sexually assaulted her at least once. A cousin told investigators of four occasions when Courtney had attempted to sexually assault her when they were both teenagers. (He was between fourteen and nineteen years old, and she was twelve to seventeen years old.) The cousin never reported the attacks because she was afraid of him (Gazette Times, 2009). When Courtney was 19, he was convicted of sex abuse and attempted rape for attacking a teenager female friend while under the influence of alcohol and drugs. His sister reported that on the encouragement of his parents, he â€Å"settled down† (Tilkin, 2009) to the point that he was able to receive counseling. He got married in the early 1990s and had three children. He lived with his family near Albuquerque, New Mexico until April 2004, when they moved in with his brother- and sister-in-law in Portland. Courtney’s brother-in-law got him a job with his employer, a maintenance company. Courtney used a van owned by his employer to abduct Wilberger in Corvallis, Oregon, 85 miles south of Portland, at the end of May. In June, Courtney’s wife left him and returned to New Mexico; he followed her and he was arrested for a domestic disturbance. He was never charged, so after his release, he reconciled with his wife and moved in with his family in Rio Rancho, New Mexico (Gazette Times, 2009). In November, he kidnapped and raped a 22-year old University of New Mexico student, but she escaped and was able to identify Courtney as her attacker. He pleaded guilty and in 2007, was sentenced to 18 years of prison. Eventua lly, police was able to link Courtney to the Wilberger case and in spite of the lack of the body of the alleged victim, charged him with 19 counts of aggregated murder, kidnapping, sexual abuse, rape, and sodomy. In exchange for providing information about the location of Wilberger’s body, a plea bargain was made, and Courtney was sentenced to life in prison without the possibility of parole, sparing him from the death penalty. The deal also provided for Courtney to serve his sentence in his home state of New Mexico (Scrabner & Netter, 2009). Wilberger’s disappearance in 2004 was covered in the national media and was one of the most highly publicized murder trials in Oregon history (Moran, 2009). Wilberger, a devout Mormon whose boyfriend was serving as a missionary in Venezuela at the time, had completed her first year at Brigham Young University She was visiting and working for her sister in Corvallis at the time of her abduction. On the morning of May 24, 2004, she was last seen cleaning lamp posts in the parking lot of the apartment building her sister and brother-in-law managed, located on the edge of Oregon State University campus. Earlier that same day, Courtney had attempted to abduct two other young college students, but failed because they were able to get away (Schrabner & Netter, 2009). According to a reporter from a local television station in Corvallis, Courtney’

Counter Culture Essay Example for Free

Counter Culture Essay Introduction From a moral standpoint, social problems harm people and from a democratic standpoint, social problems harm the well-being of citizens. In addition to that, from a societal standpoint, social problems threaten the productive functioning of society. A social problem is said to exist to the extent that some malfunction is observed in society. This malfunction might be an inequality (e.g:with the same education and experience women earn only about 80% of what men earn in the labor force), a poor allocation of resources (e. g: poor environmental stewardship), violence (e.g: domestic violence, rape, violent crime), or an inefficient organizational system (e.g: too much or too little being spent on social services). The social evils that are plaguing our society today could hardly be catalogued, they are uncountable in the true sense of the assertion. Among the prominent social problems are the escalating crime waves , religious intolerance , disrespect for elders , laziness and lateness of duty , widespread of diseases , ostentatious spending, abortion, pre marital pregnancy, elope (run off secretly to be married and usually without the consent or knowledge of one’s parent), disciplinary problem, psychological problem, slow down development of the country, and alcohol consumption . These are the effects of our social problem among Malaysian youth. Sociologists can identify many aspects of society that might be considered to be social problems. It is the values held by the majority of citizens (in a democracy) that define what is a social problem (e.g:Is denial of same-sex marriages a problem?). Social problems are identified as such partly with respect to their perceived effect on the productive functioning of society. Social problems can be difficult to identify (e.g:What is the scientific evidence that same-sex marriages or the prohibition of them will harm society?). Sociologists use the consensus, conflict, and interactionist perspectives to examine these conditions of potential social problems. Risk Factors for Social Problems Risk factor is defined as a factor which increases the chances of social  problems beyond control. There are different risk factors for social problems among youth such as biological, psychological and social. Social risk factors include unemployment, disturbed family environment, unavailability of educational opportunities, availability of drugs in locality, law and order situation. Environmental/social risk factors are increasing the chances of using drugs among youth. A youngster who is disturbed because of his family environment will spend time out side of his home, sitting with friends who can offer him drugs. Handling peer pressure will be difficult for him, as a result, he will be ready to use drug. A youngster deprived of educational opportunities and economic resources may be at great risk of using drugs. His disappointment from social problems will produce images of drugs in his mind as the suitable source of getting rid of his problems. Easy availability of drugs/substance in his locality will further serve to increase his craving for drugs. Also the principal and behavioural factors linked with youth violence are hypersensitivity, impulsiveness, poor behavioural control, attention problems, history of early aggressive behaviour and low educational achievement. Associating with delinquent peers has also been linked to violence in young people. Gangs and a local supply of guns and drugs are a potent mixture, increasing the likelihood of youth violence. Low level of social cohesion within community has been linked to higher rates social problems. Cultures that do not provide non-violent alternatives for resolving conflicts appear to have higher rates of social problems too. For most young people, the offending behaviour is part of growing up, of testing the limits, of taking risks, of asserting their independence. It may also be an indication of boredom and the absence of anything useful or meaningful to do. It may be a reflection of that awkward stage of life where one feels grown up but not able to participate fully in the world of adults. Generally, the offenses that they commit are relatively minor and decrease in frequency as they grow older, mature and find a way to participate in and contribute to society. Ways to overcome social problems The role of parents is crucial in giving serious attention to their children. Parents must consider the movements of their children. Parents should always know and identify the problems faced by their children and are willing to take the time to solve the problem. Parents also should know their child’s friends and always make sure their children make friends and socialize with those who have well in morally. In addition parents must spend part of daily time with children by giving them confidence, courage, creating positive attitudes towards issues, emotions and decisions. Another common set of prevention strategies addressing youth violence focuses on early intervention with children and families. Such programmes provide parents with information about child development and teach them how to effectively discipline, monitor and supervise children, as well as how to manage family conflict and improve communication. Parent and family -based interventions are among the most promis ing strategies for producing long-term reductions in youth violence. 2. Academic approach. This can be done by adding activities based on academic and semi-academics activities such as extra-curricular in schools. Similarly, the changes in teaching techniques such as use of computer, video, audio-visual aid equipment and techniques of teaching outside the classroom should be implemented. 3. Establishing legal system in the school. Provisions in the law school could create fear among students, in addition to reducing the burden and responsibility of the school and the parents in monitoring discipline. 4. Law enforcement authorities like the police. Jurisdiction of the existing police should be used by school administrators in the discipline of students. The administrator shall take the opportunity to refer their student’s problems to police. 5. Preventive measures should be held as appropriate counselling at school level. Counselling at school level is important in helping teenagers overcome their problems. This program will be more meaningful i f the counsellors are qualified and experienced elected. 6. Parents and Teachers Association (PTA) should play an important role more frequent meetings between parents, guardians and teachers should be held  especially for students that influenced in social problems. Parents should discuss student’s problem with teacher and get ready to receive and advice from a teacher with an open and positive attitude. If one considers that ultimately we are concerned with the healthy development of adolescents in transition to adulthood, we must be concerned with the issues that impede or impact on such transitions. Transition to adulthood includes simultaneous transitions across several domains including post-secondary education or other work preparation training, labour force participation (or unemployment) independent living, marriage or cohabitation, and community living. Transition success is affected by many factors including personal characteristics, gender, family influences, exposure to role models, economic status, cultural influence s, and the economic viability of the community in which the person functions. We also be mindful of the fact that adolescence occurs in a context with such factors as race, ethnicity, cultural customs, language, social views and practices, sexual orientation and physical or learning disabilities all combining to make the transition experiences of some adolescents very different from others. While there has been a fair amount of work done on identifying risk factors that, if present, may increase the likelihood of a young persons involvement in crime or other negative behaviour problems, there has also been some work done on the development of programs that build on the enhancement of protective factors which may reduce the effects of exposure to risk factors and thus lower the chances a youth will develop serious anti-social or other behaviour problems or become a victim.. Protective factors may also divide into: (1) Individual characteristics (i.e. high IQ, high level of resilience and flexibility and a positive social attitude); (2) Social bonds ( notably warm, supportive and affective   relationships with parents and other adults); and (3) Social support including positive social skills and socially acceptable pattern of behavioural norms. Possession of problem-solving, Life and communication skills. Sociability, Resilient personality or temperament A sense of belonging, secure attachments to positive parent(s) or family Positive relations with â€Å"pro social† peers Access to other caring supportive adults Appropriate discipline Limit-setting and structure from parents, Opportunities to experience success and build self esteem In the context of transitions from adolescence to healthy adulthood, it is important to consider the notion of resilience as a young persons ability to cope in the presence of major stress or risk factors. They go on to suggest that resilience is a source of strength in young people created or nurtured by caring and effective parents or other adult caregivers, positive learning environments in schools and access to community resources. What is the value of having an assessment to identify potential risks and needs of young offenders? By objectively identifying young persons who pose a higher risk of re-offending and the program interventions that are needed Assessments allow for a potentially more efficient and effective use of resources More objective and consistent decision making Establishing a baseline for monitoring a young offender’s progress Periodic reassessment of rehabilitative effectiveness Appropriate targeting of program intervention to address the social problems factors associated with offending (risk-needs assessment) such as: Use of appropriate modes of intervention based on social learning principles A multiplicity of available interventions to address differing individual needs Consistent application of interventions to ensure program integrity Quality assurance of program design and delivery including training and recruiting appropriate staff Strong theoretical base or mission for the program We should be careful not to suggest that a program has not been successful if a young person re-offends. While rehabilitative programs are designed with a goal of reducing recidivism, it is essential that other forms of program success are included in the mix and not totally rely on measures of recidivism to determine success. We can reduce occasional or temporary  offending by young people by helping them deal with the stress associated with the turbulence of adolescence and finding ways of involving young people in useful and meaningful activities. Educational and recreational activities to which all have equal access and which are designed on the basis of the varied needs and interests of young people are important. Access to social services can help some young people and their families deal with problems which may underlie the offending behaviour. Given what we know about the correlation between poverty, mental health and opportunities, the economic security of young people and their families should also be a priority. These measures are all primary prevention strategies ways of creating healthier and ultimately safer communities. Conclusion Though social problems are recurrent issues in many societies all over the world, they can be predetermined and controlled by use of social studies. When we think of the many settings that have evolved over time, it becomes apparent that there can never be a permanent solution to these social problems. Governments in affected regions try to curb socially unacceptable behaviour by regulating wealth and economy for citizens, thereby ensuring that money distribution is constant and fluent enough to avoid situations where some feel exploited. More measures can be taken to avoid socially unacceptable behaviour like crime and drug use, thereby maintaining law and order in society. Society is the place where young generations are brought up and nurtured for future. If social problems are left to come up and establish themselves, the upcoming generations would grow up to become savage and barbaric citizen, destroying civilization that was once prosperous.

Organic Foods Pdf Essay Example for Free

Organic Foods Pdf Essay Abstract: During the last decade, consumers’ trust in food quality has decreased drastically, mainly because of growing ecological awareness and several food scandals (e. g. BSE, dioxins, bacterial contamination). It has been found that intensive conventional agriculture can introduce contaminants into the food chain. Consumers have started to look for safer and better controlled foods produced in more environmentally friendly, authentic and local systems. Organically produced foods are widely believed to satisfy the above demands, leading to lower environmental impacts and higher nutritive values. So far, studies have partly con? rmed this opinion. Organic crops contain fewer nitrates, nitrites and pesticide residues but, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars than conventional crops. Organic crops also contain statistically more mineral compounds and usually have better sensory and long-term storage qualities. However, there are also some negatives: plants cultivated in organic systems generally have 20% lower yields than conventionally produced crops. Several important problems need to be addressed in the coming years: environmental, bacterial and fungal contamination of organic crops and, the most essential issue, the impact of organic food consumption on animal and human health.  © 2007 Society of Chemical Industry Keywords: organic plant crops; quality; yield; composition; nutrition; vitamins; phenolics; sugars; nitrates; nitrites; pesticides; dry matter; health; sensory qualities. FACTORS INFLUENCING THE QUALITY OF ORGANIC PLANT FOOD PRODUCTS There are several important factors in?uencing the quality of food products that also are relevant to organically produced plant products. As illustrated in Fig. 1, the basic factors are the quality of the environment (abiotic factors) and the levels of pest and pathogen damage (biotic factors) to which plants are subjected. The main components of the environment (air, water, soil) have to be unpolluted if the crops obtained are expected to be of high nutritive quality. Many environmental contaminants enter the food production chain (soil–plant–animal–human organism), causing signi? cant problems in human health. 1 These contaminants include heavy metals, pesticide residues, nitrogen compounds, mycotoxins, chlorinated biphenyls (PCBs), aromatic hydrocarbons (e. g. benzo[a]pyrene), plant growth stimulators (e. g. choline chloride), antibiotics, hormones, radioactive isotopes and plastic substances (monomers). Climate and weather are also important factors, as well as soil type and pH, soil cultivation, fertilisation and conditions of crop storage after harvest. ? Biotic factors can have also a signi? cant impact on crop quality. The main biotic factors are cultivar choice, bacterial and fungal contamination (disease) and pest damage. Cultivars of the same crop species can differ signi? cantly in nutritive quality. For example, the content of ? carotene in carrots (Daucus carota L. ) can vary between 7. 19 and 13. 84 mg g? 1 depending on the cultivar. 2 The main potential source of bacterial contamination in plant crops is animal manure used in organic farming. Contamination can take place via the roots or by water splashing onto the leaf surfaces. The most important organisms are several species of facultative anaerobic bacteria (Salmonella enterica, Escherichia coli O157:H7, Campylobacter spp., Listeria monocytogenes, Clostridium botulinum, Mycobacterium paratuberculosis), protozoa (Toxoplasma gondii), tapeworms, viruses and prions. The results obtained so far are contradictory. Some studies indicate higher bacterial contamination in organic crops, while others show the opposite. 3 Mycotoxins (produced by fungi) originate mostly in the ? eld but can also develop during storage. Owing to the fact that fungicides are not used Correspondence to: Ewa Rembialkowska, Organic Foodstuffs Division, Faculty of Human Nutrition and Consumer Sciences, Warsaw Agricultural University, Nowoursynowska 159 C, PL-02-776 Warszawa, Poland E-mail: ewa [emailprotected] pl (Received 24 October 2006; revised version received 29 January 2007; accepted 8 February 2007). Figure 1. Factors in? uencing the quality of organic food products. in organic agriculture, some authors believe that organically produced foods will contain higher concentrations of mycotoxins. However, literature reviews show that mycotoxin concentrations are usually similar or reduced in organic compared with conventional products. 4 The most notorious mycotoxins are those produced by Fusarium species on cereal crops and maize. One of the reasons for lower Fusarium infections in organic grains could be the lower nitrogen concentrations in the tissues. 5 Insect pests also exert an in? uence on crop quality. Because of the ban on synthetic pesticides in organic agriculture, insects often damage fruits and vegetables, thereby diminishing their yield and harming their appearance. However, it is not clear whether they also reduce their nutritive quality. In contrast, there is evidence that organically grown plants contain more phytochemicals (which are natural insecticides) and are therefore more resistant to insect damage. 6 They can also play a positive role in human health, because several phytochemicals, being plant defence compounds, are connected with possible health bene? ts (Brandt K, oral presentation at QLIF Congress, Newcastle, 2005). Regulations on organic plant production allow actions that avoid many negative features of crop quality if they are consistently performed by producers. In order to ful? l these demands and to offer highquality products to consumers, an ef? cient and airtight certi? cation and control system must be implemented. In most countries such systems are quite ef?cient, though a rapid increase in the number of organic farms could lead to problems with a subsequent loosening of regulatory control. Therefore the main rule should be ‘trust is good, but control is better’. Moreover, the ? nal quality of organic food products is in? uenced by the effective implementation of 2758 the regulations on animal production and organic food processing. Only precise ful? lment of all these regulations can guarantee the best organic food quality (Fig. 1). IMPACT OF REGULATION ON ORGANIC PLANT PRODUCTION The regulations for organic plant production are clear and detailed. 7 The European Union (EU) regulation published in 19918 contains parts that relate directly to the composition of organic plant products. The most important aspects of this regulation include:7 †¢ a ban on genetic engineering and genetically modi? ed organisms (GMOs); †¢ lower nitrogen levels – a maximum limit for manure application of 170 kg N ha? 1 year? 1 ; †¢ a ban on synthetic pesticides; †¢ a ban on synthetic mineral fertilisers; †¢ a ban on growth promoters. Organic farmers must follow the above regulations if they want to pass the inspection procedure every year and receive a certi? cation document. If all requirements are complied with, several qualitative results can be expected. The most important conclusions from scienti? c comparisons are given below. CONTAMINANTS Nitrates and nitrites A large amount of data shows that the content of nitrates and nitrites is distinctly higher in conventionally cultivated than in organic crops. This is important, because nitrates can easily be converted into nitrites, which can cause a dangerous illness called methaemoglobinaemia in babies, infants and elderly people. 9 J Sci Food Agric 87:2757–2762 (2007) DOI: 10. 1002/jsfa Quality of organic plant products. Moreover, nitrites can react with amines to create nitrosamines, which are carcinogenic and mutagenic substances causing cancer of the digestive tract and leukaemia. 10 This process is dangerous not only for young children but also for adults of any age. Based on a large amount of data, the nitrate content of organic and conventional crops has been compared. On average, the nitrate content of organic crops was 49% that of conventional crops. 11 These and other data provide a basis for stating that organic methods lead to an approximately 50% reduction in the intake of nitrates and nitrites by humans. Pesticides Governments place legal limits, known as the Maximum Residue Level (MRL), on the level of pesticides that can be present in food. The MRL is usually estimated by testing individual pesticides on rats. Governments maintain that consumption of pesticides below the MRL is not a health risk. However, at lower levels, pesticides are known or suspected to cause many diseases and health problems, including cancer. 12 The main problem is that the MRL for pesticides is usually estimated by testing individual pesticides on rats for a relatively short period. Virtually nothing is known about the effects of consuming combinations of potentially hundreds of different pesticides over the course of a lifetime. We do not and cannot know explicitly what is causing what, so precaution is the main tool available to us (Howard V, oral presentation at QLIF Congress, Newcastle, 2005). The levels of pesticide residues found in organic crops are de? nitely lower than those present in conventional crops (Howard V, oral presentation at QLIF Congress, Newcastle, 2005). It can be expected that eating organic foods will result in lower pesticide levels in human milk and body tissues. There is some evidence con? rming this hypothesis. Researchers in France found that the level of pesticide residues in the milk of breast-feeding women decreased signi? cantly with an increase in the proportion of organic food in the daily diet (from 25 to 80%). 13 All available results show that the content of pesticide residues is signi? cantly lower in organic crops, which creates safer health conditions for consumers eating organically. Heavy metals Heavy metals such as cadmium, lead, arsenic, mercury and zinc are introduced into the food chain from various sources, including industry, transportation, communal wastes and agriculture. For example, mineral phosphoric fertilisers used in conventional agriculture can introduce cadmium into crops, but the metal industry and transportation also cause cadmium contamination of soils and crops. Therefore there are no clear results in studies comparing the levels of J Sci Food Agric 87:2757–2762 (2007) DOI: 10. 1002/jsfa heavy metals in organic and conventional crops. Some data point to higher levels in conventional crops, while others show the opposite. 11 A problem to be solved is whether organic farming (composting, increasing the organic matter in soil, pH, etc. ) can diminish the intake of heavy metals by cultivated plants. DESIRABLE COMPOUNDS IN PLANTS Vitamins, phenolic compounds and mineral compounds The nutritive value of foods depends mainly on them having the appropriate content of compounds indispensable for proper functioning of the human organism. The content of phyto-compounds in plant foods is a topic of great interest in food science nowadays. A growing body of evidence indicates that secondary plant metabolites (phytochemicals) play a critical role in human health and may be nutritionally important. 14 There are two main theories explaining the factors in? uencing the levels of compounds in plants. 15 The carbon/nitrogen (C/N) balance theory states that, when nitrogen is easily available, the plant will ? rst make compounds with high nitrogen content, e. g. proteins for growth and nitrogen-containing secondary metabolites such as alkaloids, glucosinolates and non-protein amino acids such as the Allium ? avour precursors. When nitrogen availability is limiting for growth, the metabolism changes more towards carboncontaining compounds, e. g. starch, cellulose and non-nitrogen-containing secondary metabolites such as phenolics and terpenoids. The second, newer theory is the growth/ differentiation balance hypothesis (GDBH). 15 It states that the plant will always assess the resources available to it and optimise its investment in processes directed towards growth or differentiation. The term ‘differentiation’ encompasseses increased formation of defence compounds as well as accelerated maturation and seed development. The C/N balance theory is a special and typical case of the GBDH theory, since low nitrogen availability is the most common growth-limiting condition in natural ecosystems. 15 To verify the above theories, several authors investigated the content of some vitamins and phyto-compounds in organically and conventionally produced crops. In order to summarise different data, for each organic–conventional comparison a % difference was calculated: [(organic ? conventional)/conventional] ? 100 The collected data for several desirable components are presented in Table 1. The role of vitamin C (ascorbic acid) in the human organism is basic for several metabolic functions, mainly because it is one of the major cellular direct antioxidants (along with glutathione) and is a 2759 E Rembialkowska Table 1. Contents of desirable components in organic crops relative to those in conventional crops Component Vitamin C Phenolic compounds Iron Magnesium Phosphorus Mean % difference +28. 7 +119. 3 +21. 1 +29. 3 +13. 6 Range (%) ? 38 to +135. 5 ? 56. 6 to +734. 2 ? 73 to +240 ? 35 to +1206 ? 44 to +240 Number of studies 21 15 16 17 18 production and reduces carbohydrate production. Moreover, the increased protein produced in response to high nitrogen levels contains lower amounts of certain essential amino acids such as lysine and therefore has a lower quality with respect to human nutrition. Source: Ref. 17 and author’s own calculations. cofactor for certain enzymes. Vitamin C also supports detoxication and resistance of the human organism. The higher content of vitamin C in organic crops is bene? cial to health, because vitamin C inhibits the in situ formation of carcinogenic nitrosamines, thus diminishing the negative impact of nitrates on the human organism. 10 Therefore organic vegetables can play an important anticarcinogenic role. Plant-based phenolic metabolites are particularly interesting because of their potential antioxidant activity and medical properties, including anticarcinogenic activity. 15 According to Benbrook,16 organic farming has elevated antioxidant levels in about 85% of the cases studied to date and, on average, levels are about 30% higher compared with foods grown conventionally. Mineral compounds containing iron, magnesium and phosphorus are fundamental for human health. According to Worthington,17 the higher mineral content in organic crops may be connected with the higher abundance of micro-organisms in organically managed soil. These micro-organisms produce many compounds that help plants to combine with soil minerals and make them more available to plant roots. Unfortunately, there have been only a few studies on other vitamins such as ? -carotene, B1 and B2 and the results are contradictory. Therefore no general conclusions can be drawn about these compounds. Total sugars A higher total sugar content in plant crops not only improves their taste but is also an important component of their technological quality, e. g. in the case of sugar beet. Studies clearly indicate a higher content of total sugars, mainly sucrose, in organically produced vegetables and fruits such as carrots, sugar beet, red beetroot, potatoes, spinach, Savoy cabbage, cherries, redcurrants and apples. 11,18 Proteins Several studies analysed in review papers11 show that the quantity of crude protein is lower in organic than in conventional crops but that the quality is better as measured by essential amino acid content. According to Worthington,17 nitrogen from any kind of fertiliser affects the quantity and quality of protein produced by plants. Provision of a large amount of nitrogen to a plant increases protein 2760 SENSORY QUALITY OF ORGANIC FOODS Many studies have proved quite unequivocally that vegetables and fruits from organic farms have a better taste and smell. This was found for carrots and potatoes, celery and red beetroot, head cabbage and tomatoes as well as for apples, cherries and redcurrants. 11 Organic fruits contained more total sugars, which probably in?uenced the better taste perception by consumers. Better taste and smell have also been found for bread made from organic grain, which also had better crumb elasticity. 6 Interesting studies have been conducted on animal food preference in which animals were given organic or conventional fodder. Most studies have proved a clear animal preference for foods produced organically; such studies have been conducted on rats, mice, hens and rabbits. 19 Preference for organic fodder was also observed in cases where, according to chemical analyses, both organic and conventional fodder ful? lled all physiological needs of the animals tested. 20 The reason for this was probably the difference in taste between organic and conventional fodder. STORAGE QUALITY OF ORGANIC PLANT CROPS Transpiration losses and decay processes, as well as changes in nutritive value, normally take place during the storage period of potatoes and other vegetables. However, these changes can proceed at different rates and to differing degrees. Most of the available data indicate that the decay process is slower in organic crops, which therefore show better storage quality after the winter period. A review study based on many sources21 concluded that the storage quality of vegetables and fruits was better in the case of plants grown on organic farms (Table 2). The better storage quality of organic crops Table 2. Storage losses of carrots, potatoes and various fruits and vegetables from organic (ORG) and conventional (CONV) farmsa Carrots Potatoes Fruits and vegetables ORG CONV ORG CONV ORG CONV Number of quoted studies Storage loss (% of initial mass) a 15 33 15 40 22 22 22 30 53 28 53 38 Average data based on literature review. 21 J Sci Food Agric 87:2757–2762 (2007) DOI: 10. 1002/jsfa Quality of organic plant products Table 3. Positive nutritive attributes of organic plant products No. 1 2 3 4 5 Attribute Organic crops contain fewer nitrates, nitrites and pesticide residues than conventional crops. There is no clear difference in the content of heavy metals between organic and conventional crops Organic plant products contain, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars. However, the level of ? -carotene is often higher in conventional plant products Organic plant products contain statistically more iron, magnesium and phosphorus. They also tend to contain more chromium, iodine, molybdenum, selenium, calcium, boron, manganese, copper, potassium, sodium, vanadium and zinc Organic plant products usually have better sensory quality. They have a clearer smell and taste and are sweeter and more compact because of their higher dry matter content Preference for organic products is typical not only for humans but also for animals such as rats, rabbits and hens. This preference was also observed in cases where, according to chemical analyses, both organic and conventional fodder ful? lled all physiological needs of the animals tested Vegetables and fruits from organic production maintain better quality during winter storage, showing lower mass losses due to transpiration, decay and decomposition processes. A possible reason for this is their higher content of dry matter, minerals, sugars and other bioactive compounds 6 Table 4. Negative and unclear aspects of organic plant products No. 1 Negative aspect Plants cultivated in organic systems have, as a rule, signi?cantly (on average 20%) lower yields than conventionally produced crops. This increases their price and creates for many consumers a barrier to buying organic foods Unclear aspect Environmental contamination (heavy metals, PCBs, dioxins, aromatic hydrocarbons) can be similar in organic and conventional crops, because the impact of industrial, transport and communal sources is similar on organic and conventional farms located in the same area Bacterial (mainly Salmonella and Campylobacter) Contamination can sometimes be higher in organic produce, but scienti?c evidence of this is still not clear Mycotoxins can contaminate both organic and conventional foods, but scienti? c data are contradictory The impact of organic food consumption on human health and wellbeing remains essentially unknown in spite of some positive indications, so the subject needs further study 2 3 4 was probably associated with a higher content of dry matter in their ? esh, resulting in less extensive decay and decomposition. Lower losses in organic production have not only nutritive but also economic bene? ts. In conventional systems, high yields are produced but signi?cant losses during storage reduce the economic bene? ts. CONCLUSIONS Recent food crises (BSE, foot and mouth disease, food contamination by dioxins, toxic fungi, Salmonella and Campylobacter bacteria) have caused consumers to look for more authentic and safer foods. Organic food production is widely recognised as being more friendly to the environment, more controlled and better for animal welfare. On the other hand, many data indicate that a lot of food contaminants have their source in conventional methods of agriculture, animal production and food processing. The negative effect of the continuing enthusiastic use of chemical fertilisers and pesticides in agriculture is potentially huge. Therefore safer methods of agricultural production, mostly organic methods, are very important. Studies conducted in various countries have indicated several positive attributes of organic plant J Sci Food Agric 87:2757–2762 (2007) DOI: 10. 1002/jsfa products (Table 3) but also a few negative and unclear aspects (Table 4). To summarise the positives, organic food should be recommended for all, but especially for young babies, pregnant and breast-feeding women, elderly and chronically ill people and vegetarians. The last group obviously consumes a lot of vegetables, which can contain too high levels of carcinogenic substances when produced conventionally. The lower content of nitrates and higher content of phenolic compounds and vitamin C in organic crops are especially important for health. Nitrates are easily converted in the digestive tract into poisonous nitrites, which are the precursors of carcinogenic nitrosamines. This process is hampered by vitamin C, and carcinogenesis is retarded by phenolic compounds and other dietary phytochemicals present at higher levels in organically produced crops. Therefore organic vegetables can play an important anticarcinogenic role. REFERENCES 1 Rembialkowska E, Organic agriculture and food quality, in Ecological Agriculture and Rural Development in Central and Eastern European Countries, Vol. 44 of NATO Science Series, ed. by Filho WL. IOS Press, Amsterdam, pp. 185–204 (2004). 2761 E Rembialkowska ? ? 2 Schuphan W, Biochemische Sortenprufung an Gartenmohren ? ? als neuzeitliche Grundlage fur planvolle Zuchtungsarbeit. Z? chter 2:25–43 (1942). U 3 Franz E, van Bruggen AHC and Semenov AM, Risk-analysis of human pathogen spread in the vegetable industry: a comparison between organic and conventional production chains, in Bayesian Statistics and Quality Modelling in the AgroFood Production Chain, ed. by van Boekel MAJS, Stein A and van Bruggen AHC. Kluwer Academic, Dordrecht, pp. 81–94 (2004). 4 FAO, Food Safety as Affected by Organic Farming (Twentysecond FAO Regional Conference for Europe). [Online]. (2000). Available: www. fao. org/docrep/meeting/x4983. htm. 5 Van Bruggen AHC and Termorshuizen AJ, Integrated approaches to root disease management in organic farming systems. Aust Plant Pathol 32:141–156 (2003). 6 Bjorn G and Fruekilde AM, Cepa onions (Allium cepa L) grown conventionally and organically – similarities and differences. Gron Viden 153:1–6 (2003). (in Danish). 7 Hansen B, Alroe HF, Kristensen ES and Wier M, Assessment of food safety in organic farming. DARCOF Working Paper 52 (2002). 8 EU, Council Regulation No. 2092/91 of 24 June 1991 on organic production of agricultural products and indications referring thereto on agricultural products and foodstuffs. OJL 198, 22. 7 P. 1 (1991). ? 9 Szponar L and Kierzkowska E, Azotany i azotyny w srodowisku oraz ich wplyw na zdrowie czlowieka. Post Hig Med Do? w s 44:327–350 (1990). 10 Mirvish SS, Vitamin C inhibition of N-nitroso compounds formation. Am J Clin Nutr 57:598–599 (1993). 11 Rembialkowska E, Wholesomeness and Sensory Quality of Potatoes and Selected Vegetables from the Organic Farms. Fundacja ? Rozwoj SGGW, Warszawa (2000). 12 BMA, The BMA Guide to Pesticides, Chemicals and Health. Report of Science and Education. British Medical Association, London (1992). 13 Aubert C, Pollution du lait maternel, une enquete de terre vivante. Quatre Saisons Jardinage 42:33–39 (1987). 14 Lundeg? rdh B and M?rtensson A, Organically produced plant a a foods – evidence of health bene? ts. Acta Agric Scand B 53:3–15 (2003). 15 Brandt K and Molgaard JP, Organic agriculture: does it enhance or reduce the nutritional value of plant foods? J Sci Food Agric 81:924–931 (2001). 16 Benbrook CM, Elevating Antioxidant Levels in Food through Organic Farming and Food Processing. An Organic Center of Science Review. Organic Center for Education and Promotion (2005). 17 Worthington V, Nutritional quality of organic versus conventional fruits, vegetables, and grains. J Alternative Compl Med 7:161–173 (2001). 18 Zadoks JC, Development of Farming Systems. Pudoc, Wageningen (1989). 19 Williams CM, Nutritional quality of organic food: shades of grey or shades of green? Proc Nutr Soc 61:19–24 (2002). ? 20 Woese K, Lange D, Boess Ch and Bogl KW, A comparison of organically and conventionally grown foods – results of a review of the relevant literature. J Sci Food Agric 74:281–293 (1997). 21 Bulling W, Qualit? tsvergleich von ‘biologisch’ und ‘konventionell’ a erzeugten Feldfruchten. Regierungsprasidium, Stuttgart (1987). 2762 J Sci Food Agric 87:2757–2762 (2007) DOI: 10. 1002/jsfa.

Analysis Of Our Planet Earth

Analysis Of Our Planet Earth Explore The planet earth is one of the nine planets in the solar system and the only known planet to harbor life and the home of human beings. From the words of Neil Armstrong, one of the astronauts of the famous Apollo 11, the earth from space resembles a big blue marble with swirling white clouds floating above blue oceans. About 71 percent of the earths surface is covered with water and the rest is land, mostly in the form of continents that rise above the oceans. Origin of the Earth The earth has a unique characteristic that is suited to supporting life. It is neither too hot like planet Mercury, the closest planet to the Sun, nor too cold like planet Mars. For thousands of years, human being could only wonder about the earth and other observable planets in the solar system. Many ideas such as the earth was a sphere and that it travelled around the Sun were based on brilliant reasoning. It was on the development of scientific method especially in the 18th and 19th centuries, that human beings began to gather data that could be used to verify theories about the earth and the rest of the solar system. In the second half of the 20th century, more advances in the study of the earth and the solar system occurred because of the development of rockets that could send spacecrafts beyond Earth. Human beings were able to study and observe Earth from space and satellites equipped with scientific instruments. Scientists have studied the solar system and tried to explain how it was formed. Billions of people are wondering how the huge, lively planet came to be. There are many different theories trying to give explanation of how our home planet came to be. One of the most popular theories of the planets origin is that of Gods creation. Many religious group as well as scientists, embrace the belief that God created the universe and the different steps motivating material and natural development and that these steps then resulted in the formation of the galaxies, the solar system and existence of the earth. This theory is known as Theistic evolution or as evolutionary creationism. This theory h olds the belief that God exceeds common time and space, with nature having no survival self-sufficient of Gods will. The Theistic Evolution Theory poses many questions that can never be answered directly. The sources available are books written by humans. Most accepted belief is the theory of creation in the book of Genesis in the Old Testament. This popular theory states that God created the universe in six days .The Bible offers no evidence to prove the story; rather it relies on the faith of the believers to accept it as truth. Another popular belief is the Big Bang Theory. This theory supports the idea that the universe came about due to a colossal explosion. According to the theory, the universe goes through a tremendously high speed rise that expands within a fraction of a second. Then, the excessive heat of electrons and other particles mix. As atoms and particles charge, still extremely hot, they prevent light from shining, creating a sweltering hot fog. Eventually, the electrons merge with additional particles to structure atoms of hydrogen and helium, causing light to at last shine. Giant clouds are soon formed by the hydrogen and helium gases. Weighty elements that are not clustered together are thrown into space to form stars and planets. Another theory is developed by Immanuel Kant and given scientific form by Pierre Simon Laplace at the end of 18th century. It is known as the Nebular Theory. It was assumed that the solar system in its first state was a nebula, a hot, slowly rotating mass of rare matter, which gradually cooled and contracted, the rotation becoming more rapid, in turn giving nebula a flattened disk-like shape .In time, rings of gaseous matter became separated from the outer part of the disk, until the diminished nebula at the center was surrounded by a series of rings. Out of the material of each ring a great ball was formed, which by shrinking eventually became a planet. The mass at the center of the system condensed to form the sun. Encounter or collision theories, in which a star passes a close by or actually collides with the sun, try to explain the distribution of angular momentum. According to the Planetisimal theory, developed by Thomas Chamberlin and Forest Ray Moulton, in the early part of 20th century, a star passed close to the sun. Huge tides were raised on the surface; and some of these erupted matters were torn free, and by a cross pull from the star, were thrust bodies called planetesimals. As their orbits crossed, the larger bodies grew by absorbing the planetisimals, thus becoming planets. The Gaseous Tidal Theory, proposed by James Jeans and Harold Jeffreys in 1918, is a variation of the planetesimal concept. It suggests that a huge tidal wave, raised on the sun by a force of gravity of a passing star, was drawn into a long filament and became detached from the principal mass. As the stream of gaseous material condensed, it separated into masses of various sizes, which by further condensation took the form of a planet. The Dynamic Encounter Theory of Georges Buffon states that the world was formed out of molten materials from the sun that collided with other planets. According to the Solar Disruption Theory by Georges-Louis Leclerc, the sun and a big star almost collided in space, which made some parts of the sun burst. The pieces formed became planets. Composition and Structure of the Earth Geologists divided the earth into three main zones: hydrosphere, lithosphere, and atmosphere. Hydrosphere consists of the bodies of water that covers 71 percent of the earths surface. The largest of these are the oceans, which contain over 97 percent of all water on Earth. Glaciers and polar ice caps contain over 2 percent of earths water in the form of solid ice. Only about 0.6 is under the surface as groundwater. Groundwater is 36 times more plentiful than water found in lakes, inland seas rivers, and in the atmosphere as water vapor. Most of the water in glacier, lakes inland seas, rivers and groundwater is fresh and can be used for drinking and in agriculture. The atmosphere is the great blanket of gases that surrounds the earth. It is arranged in five layers: troposphere, stratosphere, mesosphere, and exosphere. Lithosphere refers to all of the earth, from its surface to its center. The earth contains three regions crust, mantle, and core. Crust is the outermost layer of the earth. The crust consists of the continents, and other land areas and the basins or floor of the oceans. It has an average thickness of 25 mile. Mantle is about 800 miles thick of solid silicate rock. Core contains iron and nickel whose outer core is liquid and the inner core is solid. Changes on the Earths Surface Think and Respond How forces inside the earth create and change landforms? Earths surface has been constantly changing ever since the planet was formed. Most of these changes have been taking place slowly over millions of years. These gradual changes resulted in modifications including the formation, erosion, re-formation of mountain ranges, the movement of continents, the creation of super continents and the break-up of smaller continents. There are factors responsible for the changes in the earths surface. These are: Weathering. Weathering is the breakdown of rock at and near the surface of the Earth. Most rocks originally formed in a hot, high pressure environment below the surface where there was little water. Once the rock reached earths surface they were subjected to temperature changes and expand to water. When rocks are subjected to these kinds of conditions, the minerals they contain tend to change. These changes constitute the process of weathering. There are two types of weathering; physical weathering and chemical weathering. Physical weathering includes a decrease in the size of rock materials. Freezing and thawing of water in rock countries for example, splits rocks into small pieces because water expands when it freezes. Chemical weathering involves a chemical change in the composition of rock. Chemical weathering is important to man because it creates the clay minerals that are important component of soil, which is the basis for agriculture. Erosion. Erosion is the process that removes loose and weathered rock and carries it to a new site. Water, wind, and glacial ice combined with the force of gravity can cause erosion. Soil erosion and gullying in the upper Panuco basin, Sierra Madre Oriental, eastern Mexico Think and Explain Why is erosion dangerous? Erosion by running water is the most common process of erosion. When water moves downhill, it can carry loose rocks or soil with it. The force of the running water removes loose particles formed by weathering. In the process, gullies and valleys are lengthened, widened, and deepen. The Grand Canyon of the Colorado River is an example of the eroding power of water. Over a million years the Colorado River has cut a canyon that is more than 1 mile deep. The Nile River of Egypt, for example, brings rich soil from the mountains and spreads it along its banks. Because of this, the Nile Valley is one of the most fertile areas in the world. It is the only part of Egypt where crops can grow, a reason why Egypt was known as The Gift of Nile. On the other hand, the Huang Ho or Yellow River in Northern China often overflows its banks and floods farms and homes. Over the years Huang Ho has done so much damage that people call this river Chinas Sorrow. Erosion can also occur as glacier, or large bodies of ice, move across the surface of the earth. As they move, glaciers change the land destroying forests, carving out valleys, altering the course of the rivers and wearing down mountaintops. Wind is an important cause of erosion only in arid or dry regions. Wind carries sand and dirt, which can scour even solid rock. Erosion caused by wind can either help or hurt people. The plains of Northern China for example, have a thick, rich type of soil that is carried by winds blowing from the deserts far to the west. This soil allows farmers in Northern China to raise great amount of wheat and other food crops. Think and Explain How do you account todays flash floods to soil erosion? Many factors determine the rate and kind of erosion that occurs in a certain area. Then climate of a given area determines the distribution, amount, and kind of precipitation that the area receives, thus, the type and rate of weathering. An area with an arid climate erodes differently than the area with a humid climate. The elevation of an area also plays an important role by determining the potential energy of running water. The higher the elevation, the more water will flow due to the force of gravity. Plate Tectonics. Think and Explain How do scientists predict when and where earthquakes may occur?Opposite the leveling is a force responsible for raising mountains, and plateaus and for creating new landmasses. These changes on earth surface occur in the outermost solid portion of Earth, known as lithosphere. The lithosphere consists of the crust and another region known as the upper mantle. Scientists believe that the lithosphere is broken into a series of plates, or segments. According to the theory of plate tectonics, these plates move around on earths surface over long periods of time. These plates move in different ways in relation to each other. They pull apart or move away from each other, they collide or move against each other, or they slide past each other as they move sideways. These shaking movements of the earth called earthquakes explain geological occurrences such as volcanic eruptions, as well as mountain building and the formation of oceans and continents. Yale Peabody Museum/www.peabody.yale.edu/platetectonics/author Earths Physical Features Earths Features The natural features of the earths land surfaces are called landforms. These features are used to describe and help people to locate specific places. Landforms Think and Explain Why is the earth the only planet for man?Landforms are defined as the natural physical features found on the surface of the earth. Landforms are created as a result of the various forces of nature such as wind, water and ice and also by the movement of the earths tectonic plates. Due to these actions, the soil gets eroded and deposited somewhere far from the site of erosion, thus leads to the formation of different landforms. Some landforms are created in a matter of few hours; others take millions of years to appear. A group of landforms in a particular area is called its landscape. Geographers and geologists refer to four major landforms. Large flat mainly grassy areas are the plains. Lands with elevations more than 1,000 feet above the surrounding areas are called mountains. Hills are elevated land masses that are less than 1,000 feet above their surroundings. Plateaus are flat elevated areas perched between 300 to 3,000 feet high. Minor landforms include buttes, canyons, valleys and basins. Think and Respond How do forces inside the earth create and change landforms? These major landforms were formed as a result of tectonic activity, or earthquakes. Other landforms are the result of volcanic eruptions. In fact, mountains that were formed by tectonic activity are called fold mountains, while those formed by volcanic eruptions are called volcanic mountains. Still other landforms resulted from the effects of weathering, erosion and the movement of glaciers. Think and Respond How did bodies of water such as rivers and seas affect societies? Mountains are perhaps the most noticeable of the major landforms and are found on every continent, as well as beneath the ocean. The highest mountain is Mount Everest in the Himalayas at 29,028 feet. The largest mountain, by volume, is Hawaiis Maono Loa. The longest chain of mountains is the Mid Ocean Range. Both Easter Island in the Pacific Ocean and Iceland are member peaks of this range. More than half of the earths surface is covered by plains like the Central Plains of the United States and the plains in Eastern China. Some plains that continue to grow in surface area are the deltas that form by land carried in the current and deposited at the mouths of major rivers. The largest deltas are the Nile River Delta, Mississippi River Delta and Rhone River Delta. Plateaus account for about 30 percent of the earths surface. They are elevations that terminate in flat lands. Some people call them tablelands because of their shape. There are often layers of both hard and soft rock in a plateau. These landforms were caused when the earths crust was forced upward. Types and Characteristic Features of Landforms There are many types of landforms on the earths surface. Each landform is characterized by its slope, elevation, soil and rock type, stratification and orientation. Some of the common types of landforms and their characteristics are the following: Mountains: Mountains are areas, which are higher than the surrounding areas and are characterized by a peak, e.g. The Himalayas. Surprisingly, they are more frequently present in the oceans than in land. A mountain is steeper than a hill. Mountains are formed due the tectonic movement such as an earthquake or a volcanic eruption. A few are resulted due to erosion of the surrounding areas by the action of wind, water or ice. Plateaus: Plateaus are large highland flat areas separated from the surrounding areas by a steep slope, e.g. The Tibetan plateau. Plateaus are formed due to various actions such as collision of the earths tectonic plates, uplift of the earths crust by the action of magma; some are resulted due to the lava flow from the volcanic eruption. Islands: Islands are areas that are completely surrounded by water, e.g. The Hawaiian Islands. Islands are formed either as a result of the volcanic eruption or due to the presence of hot spots on the lithosphere. Plains: Plains are flat areas or low relief areas on the earths surface, e.g. prairies, steppes. Plains are formed due to the sedimentation of the eroded soil from the hills and mountains or due to the flowing lava deposited by the agents of wind, water and ice. Valleys: Valleys are flat areas of land between the hills or mountains, e.g. The California Central Valley. Mostly they are formed by the actions of rivers and glaciers. Depending upon the shape, valley forms are classified as U-shaped or V-shaped valley. V-shaped valleys are formed by flowing water or rivers, whereas U-shaped valleys are formed by glaciers. Deserts: Deserts are very dry lands with little or no rainfall, for example, The Sahara desert. Mostly deserts are formed in rain shadow areas, which are leeward of a mountain range with respect to the wind direction. Thus, the mountains block the passage of wind resulting in little or sometimes no rain. Loess: Loess are deposits of silt and with a little amount of sand and clay. Many a times wind action is responsible for formation of loess; however sometimes glacial activity can also form loess. Rivers: Rivers are natural flowing stream of freshwater, e.g. The Nile. They mostly flow towards lakes or oceans but sometimes they dried up without reaching another water body. River water is collected from the surface water runoffs, groundwater water recharge and sometimes from the water reservoirs such as glaciers. Landforms definitely play an important role in the formation of rivers. Oceans: Oceans are the biggest form of water and are saline, such as The Pacific Ocean. Oceans of the world covers around 71% of the earths surface and control the weather and climate of the earths surface. Think and Explain Are landforms still affecting todays development? Glaciers: Glaciers are huge slow moving body of ice. Glaciers are formed due to the compaction of snow layers and moves with respect to gravity and pressure. Mainly there are two types of glaciers- Alpine glaciers, which are formed in high mountains and Continental glaciers, which are formed in cold Polar Regions. Continents Land surface of the earth was divided into seven landmasses called continents. Land surface of the earth was divided into seven landmasses called continents. A continent is defined as a large unbroken land mass completely surrounded by water, although in some cases continents are (or were in part) connected by land bridges. The seven continents are North America, South America, Europe, Asia, Africa, Australia, and Antarctica. The islands in the Pacific are often called Oceania. Illus. 1. The seven continents of the world. Europe Geographically, Europe, including the British Isles, is a large western peninsula of the continent of Asia; and many geographers, refer to Europe and Asia, as the Eurasian continent. But traditionally, Europe is counted as a separate continent, with the Ural and the Caucasus mountains forming the line of demarcation between Europe and Asia. Europe is a large peninsula with a long irregular coastline with varied mountains, and islands. The continent of Europe is a relatively small part of the Eurasian landmass, encompassing 3,827,308 square miles. It is bounded on the west by the Atlantic Ocean, on the south by the Mediterranean Sea and the Black Sea, on the east by Asia, and on the north by the Arctic Ocean. Europes highest point is Mt. Elbrus in Russia, at 18,510 feet above sea level. Its lowest point is the Caspian Sea in Russia, at 90 feet below sea level. The longest river in Europe is the Volga, which runs through Russia for about 2,300 miles. Also in Russia is the continents largest lake, Lake Ladoga, which covers an area of 6,834 square miles. Europe consists of over 40 countries, with approximate total population of 803, 850, 858 in 2009. Its two major English-speaking countries, the United Kingdom and Ireland, are island nations. Germany and France are the two most populous nations of central Europe. Two of Europes southernmost countries, Greece and Italy are Mediterranean Sea peninsulas. Four of the continents northern countries Denmark, Finland, Norway, and Sweden comprise a region known as Scandinavia. Asia Think and Respond What physical features might have been a great help for the Europeans to explore and settle in the Philippines? Asia is the largest of the Earths seven continents, lying almost entirely in the Northern Hemisphere. With outlying islands, it covers an estimated 44,391,000 sq km (17,139,000 sq mi), or about 30 percent of the worlds total land area. Its peoples account for three-fifths of the worlds population; in 2009 Asia had an estimated 4.10 billion inhabitants. Most geographers regard Asia as bounded on the north by the Arctic Ocean, on the east by the Bering Strait and the Pacific Ocean, on the south by the Indian Ocean, and on the southwest by the Red Sea and Mediterranean Sea. On the west, the Ural Mountain serves as boundary between Europe and Asia. Some geographers include Europe and Asia together in a larger Eurasian region, noting that western Asian countries, such as Turkey, merge almost imperceptibly into Europe. The continental mainland stretches from the southern end of the Malay Peninsula to Cape Chelyuskin in Siberia. The lowest and highest points on the Earths surface are in Asia, namely, the shore of the Dead Sea which is 408 m/1,340 ft. below sea level in 1996) and Mount Everest which is which is about 8,850 m/29,035 ft above sea level. Asia is divided into different regional groups namely; Southwest Asia, South Asia, East Asia, Southeast Asia and Central or North Asia. Southwest Asia spans a vast area that encompasses the following countries; Afghanistan, Bahrain, Cyprus, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Libya, Saudi Arabia, Syria, Turkey, and United Arab Emirates. South Asia is a large landmass that extends southward from the continent of Asia into the Indian Ocean its nearly 1,591,890 square mile or 2,561,351 sq km occupying about 10 percent of the land area of Asia. This region includes the following countries; Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri-Lanka. East Asia is separated from the rest of the Asian continent by rugged highlands and towering mountain ranges. It comprises the following countries; China, Japan, Mongolia, North Korea, South Korea, and Taiwan. Southeast Asia covers a land area of about 1.7 million square miles or 4.4 million sq km. It is bordered by the Pacific Ocean to the east and the Bay of Bengal and the Indian Ocean to the west and south. The following countries are included in the region; Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam. Central Asia/ North Asia is a region from the Caspian Sea in the west to Central China in the east, and from Southern Russia in the north to Afghanistan in the south. It has a varied geography. The region includes the following countries: Georgia, Armenia, Azerbaijan, Kazakhstan, Tajikistan, Turkmenistan, and Uzbekistan. North America The third-largest continent on Earth is North America. It lies mostly between the Arctic Circle and the Tropic of Cancer. It is almost completely surrounded by bodies of water, including the Pacific Ocean, the Bering Strait, the Arctic Ocean, the Atlantic Ocean, and the Caribbean Sea and Gulf of Mexico. Area: 9,361,791 sq mi (24,247,039 sq km). Population (2008 est.): 528, 720, 588. It is shaped like an inverted triangle .To the southeast are the Appalachian Mountains and to the west are the younger and much taller Cordilleras. These mountains extend the length of the continent and occupy about one-third of the total land area. The Rocky Mountains constitute the eastern Cordillera. The highest point is Mount McKinley. The Mississippi River basin, including its major tributaries, the Missouri and Ohio, occupies more than one-eighth of the continents total area. Generally temperate climatic conditions prevail. South America South America, fourth largest of the Earths seven continents after Asia, Africa, and North America occupying 17,820,900 sq km (6,880,700 sq mi), or 12 percent of the Earths land surface. It lies astride the equator and tropic of Capricorn and is joined by the Isthmus of Panama, on the north, to Central and North America. The continent extends 7,400 km (4,600 mi) from the Caribbean on the north to Cape Horn on the south, and its maximum width, between Ponta do Seixas, on Brazils Atlantic coast, and Punta Parià ±as on Perus Pacific coast, is 5,160 km (3,210 mi). South America has a 2009 estimated population of 394 million, or 6 percent of the worlds people. The continent comprises 12 nations. Ten of the countries are Latin: Argentina, Bolivia, Brazil, Chile, Columbia, Ecuador, Paraguay, Peru, Uruguay, and Venezuela. Two of the nations are former dependencies: Guyana, of the United Kingdom, and Suriname, of The Netherlands. South America also includes French Guiana, an overseas departm ent of France. The coastline of South America is relatively regular except in the extreme south and southwest, where it is indented by numerous inlet. The Andes Mountain, the second highest mountain range in the world is situated, in South America. The main lowland is the vast Amazon Basin in the equatorial part of the continent; it is drained by the Amazon River, the worlds second longest river. The Orinoco River drains a lowland in the north; to the south lies the Paraguay-Parana basin. The lowest point in South America (40 m/ 131 ft below sea level) is on Peninsula Valdà ©s in eastern Argentina, and the greatest elevation (6,960 m/22,834 ft) is atop Aconcagua in western Argentina, the highest peak in the Western Hemisphere. Africa Africa is the second largest of the earths seven continents, covering, with adjacent islands, about 30,300,000 sq km (about 11,699,000 sq mi), or about 20% of the worlds total land area. In the mid 2009, some 999 million people, or about 14.72% of the worlds population inhabited Africa. Straddling the equator, Africa stretches about 8000 km (about 4970 mi) from its northernmost point, Cape Blanc (ar-Ras al-Abyad) in Tunisia, to its southernmost tip, Cape Agulhas in South Africa. The maximum width of the continent, measured from the tip of Cape Verde in Senegal, in the West, to Ras Hafun in Somalia, in the East, is about 7560 km (about 4700 mi). The highest point on the continent is the perpetually snowcapped Mt. Kilimanjaro (5895 m/19,340 ft) in Tanzania, and the lowest is Lake Assal (153 m/502 ft below sea level) in Djibouti. Africa has a regular coastline characterized by few indentations. Its total length is only about 30,490 km (about 18,950 mi); the length of its coastline in proportion to its area is less than that of any other continent. Think and Respond Why are the people in the desert usually nomads? The chief islands of Africa include Madagascar, Zanzibar, Pemba, Mauritius, Rà ©union, the Seychelles, and the Comoro islands in the Indian Ocean; Sà £o Tomà ©, Prà ­ncipe, Annobà ³n, and Bioko in the Gulf of Guinea; Saint Helena, Ascension, and the Bijagà ³s islands in the Atlantic; and the Cape Verde, Canary, and Madeira Islands in the North Atlantic. Africa may be divided into three major regions: the Northern Plateau, the Central and Southern Plateau, and the Eastern Highlands. Low-lying coastal strips, with the exception of the Mediterranean coast and the Guinea coast, are generally narrow and rise sharply to the plateau. The outstanding feature of the Northern Plateau is the Sahara, the great desert that occupies more than one-quarter of Africa. At the border of the Northern Plateau are several mountainous regions. To the Northwest lies the Atlas Mountain, a chain of rugged peaks linked by high plateaus, which extend from Morocco into Tunisia. Other prominent uplands are the Futa Jallon, on the Southwest, and the Adamawa Massif and the Cameroon mountain range, on the South. The Lake Chad Basin is situated in the approximate center of the Northern Plateau. The Central and Southern Plateau is considerably higher than the Northern Plateau and includes west central and South Africa. It contains several major depressions, notably the Congo River Basin and the Kalahari Desert. Other feature South of this plateau is the Drakensberg Mountain. The Eastern Highlands, the highest portion of the continent, lie near the east coast, extending from the Red Sea South to the Zambezi River. South of the Ethiopian Plateau are a number of towering volcanic peaks, including Mt. Kilimanjaro, Mt. Kenya, and Mt. Elgon. West of the Great Rift Valley is the Ruwenzori Range. Australia/Oceania The continent of Australia/Oceania links together the continental landmass of Australia with the huge number of widely scattered islands across the Pacific Ocean. This continent includes New Guinea, Tasmania, New Zealand, Hawaii, and the countless islands of Melanesia, Micronesia, and Polynesia. The continent of Australia is such a relatively low and flat place. Although the Great Dividing Range has some interesting areas such as the Blue Mountains area, and there is some nice mountain scenery, the bulk of the continent is simply just not mountainous at all. The highest point on the Australian landmass is Mt. Kosciusko (7310/2228m), a peak with a road to the top. The continent of Australia/Oceania holds a respectable amount of serious mountains situated in the Oceania. In New Zealand and New Guinea are world-class mountain ranges: Puncak Java, which is 5,030 meter, and in New Guinea is the highest summit in this part of the world. There is also the Southern Alps of New Zealand, which is a craggy, snowy range that challenges the best climbers in the world. Many other islands of Oceania hold mountains that are either higher or more interesting that those of mainland Australia; highlights include the ranges of Tasmania, Tahiti, Fiji, the Solomon Islands, and the massive shield volcanoes of Hawaii. Antarctica is the fifth largest of Earths seven continents. Antarctica surrounds the South Pole and is a place of extremes. It is the southernmost, coldest, iciest, driest, windiest, most remote, and most recently discovered continent. Nearly the entire landmass lies within the Antarctic Circles. Air temperatures of the high inland regions fall below -80 °C (-110 °F) in winter and rise only to -30 °C (-20 °F) in summer. Massive ice sheets built up from snow over millions of years cover almost all of the continent and float in huge ice shelves on coastal waters. In winter, frozen seawater (sea ice) more than doubles the size of the Antarctic ice cap. Antarcticas vast areas of ice on land and on sea play a major role in Earths climate and could be strongly affected by global warming. The melting of Antarctic ice could dramatically raise global sea level. Antarctica means opposite to the Arctic, Earths northernmost region. Antarctica is completely encircled` by the Southern Ocean. The entire area south of the Antarctic Convergence is referred to as the Antarctic region. The Earth Ensure Changes in the Earths Surface Composition and Structure Origin Atmosphe