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RUDOLPH BROWN PHOTOGRAPHER

Medical students Kerry-Ann Banett (left) and Robyn Beckles look through a StereoMaster compound microscope at the RADA booth at the UWI Annual Career Expo, Assembly Hall, UWI, on Friday, February 24. YOUTHLINK MAGAZINE |

MARCH 6, 2012 MARCH 6-12, 2012

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Vectors

yl:mathematics

AST WEEK you were given solutions to select past-paper questions. I hope that you found the entire exercise beneficial. You are expected, of course, to continue to do other examples on your own. Past papers are available in the bookshops and you should endeavour to make use of these, along with the examples you will find in your textbooks.

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This week we will begin the review of vectors. Please review the following description: (a) A motor car travels with velocity 45 km per hour due north. (b) A force of 25 N due East. Could you say what both statements have in common? You are correct that in both cases their sizes and directions are given. These are examples of vector quantities representing velocity of a car and force, respectively. A vector quantity is one which identifies both the magnitude (size) and direction, for example, velocity given above. A speed of 20 metres per second is a scalar quantity. (No direction is given). Vector quantities are usually represented in the form:

Clement Radcliffe is an independent contributor. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

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YOUTHLINK MAGAZINE | MARCH 6-12, 2012

Enzyme knowledge yl:biology

MONACIA WILLIAMS Contributor

OW ARE you this week? I don’t know why I am asking you this because I should know by now that you are always good and feeling on top of the world, shouldn’t I? It is a nice feeling, isn’t it?

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This week our topic differs from the usual but it suits what we are currently studying. Why is this so? The study of enzymes occupies a very small portion of the syllabus but the questions it can generate are far-reaching! A considerable portion of your time should be spent doing the laboratory work that will help you to understand the different concepts that you need to master. Fortunately for you, there are experiments that you can do at home by yourself even if your teacher does not do them with you. You do not have to buy expensive enzymes; there is one enzyme which will allow you to carry out experiments, the results of which can be quite spectacular. This enzyme is catalase. Catalase is found in living organisms, both plants and animals. It is used to break down hydrogen peroxide, a substance that is formed as a result of reactions taking place in the cells. Unfortunately, hydrogen peroxide is toxic to the body and, hence, it must be removed as soon as it is formed. Catalase converts hydrogen peroxide to water and oxygen, substances which are harmless and can be used by the body. Good sources of catalase are liver, Irish potato and leaves. The liver can be from any animal including chickens; chicken liver can be obtained easily so it is a good source. For these experiments, the substrate is the hydrogen peroxide, the enzyme; catalase and the end products are, as stated previously, water and oxygen. What are the things that can affect the activity of enzymes? m Substrate concentration m Enzyme concentrate m Extremes of temperature, with high temperatures being more harmful than cold m pH Grinding the liver, potato or the leaves and mixing the ground product with water will provide an extract of the enzyme. It also increases the number of enzyme particles available for the

reaction so the rate of the reaction increases. Circles of filter paper made using a paper punch can be soaked in the extract to provide enzyme for the experiment. Using the punch to make the circles ensures that all the circles are identical in size, thus making the results more reliable. The rate of the reaction can be measured by the rate at which soaked circles rise from the bottom of the solution to the top. Five circles are used and the time taken for them to rise is averaged to get the mean rate. How is this done? The extract is prepared by grinding the plant material in a mortar using a pestle. What happens next depends on the type of experiment that will be done. Let us see how we could carry out an experiment to determine how pH affects the activity of catalase. We will need for our experiment:

APPARATUS/MATERIALS 5 beakers, forceps, stopwatch or watch with second hand, hydrogen peroxide solution, potato extract, 30 circles of filter paper, measuring cylinder, buffer solutions of pH 3, 4, 5, 6, 7 and 8.

METHOD

m Label 5 small beakers (50cm3), pH3, 4, 5, 6, 7 and 8. m Measure 5cm3 of the peroxide solution into each beaker. m Add 10cm3 of the specific buffer to the correctly labelled beaker. m Pick up a filter paper circle with the forceps; drop it in the pH3 beaker. Start the stopwatch as soon as the paper is dropped. m As soon as the paper gets to the surface, stop the timing. m Record the time and repeat the two previous steps with four other paper circles. m Record the times then find the average time taken for the five circles to rise. m Repeat the steps with the other solutions. m Use the results to create a table. m Draw a graph to show the results.

In writing up the experiment, the table created and the graph drawn would form the results. The graph is going to show a pH at which the rate is fastest. How would we use the information to

write the discussion? Do you remember the hints I gave you the last time we discussed experiments? Of course, you do! You would begin with an introduction based on the following pattern: Enzymes are biological catalysts. Catalysts are substances which alter the rate of reactions without becoming changed during the reaction. Enzymes are affected by changes in the pH of solutions and they have specific pHs at which they operate best. Catalase is an enzyme found in living organisms. This enzyme is responsible for the conversion of hydrogen peroxide to oxygen and water. What would you write next? The next paragraphs should be used for discussing the results of the experiment, for example, at what pH did the paper take the shortest time to rise? At what pH did it take the longest time? What did you see happening while the experiment was taking place? If you were looking carefully, and you should have been, you would have seen bubbles forming on the surface of the paper and as they formed the paper rose from the bottom of the beaker to the top. Let us see how we could use this information to continue. The reaction appears to take place on the paper as bubbles appear on the surface of the paper and nowhere else in the solution. The bubbles cause the paper to become lighter, so it rises. The rate at which the bubbles are formed, causing the paper to rise, is an indication of how fast the gas is being produced and, hence, how fast the reaction is taking place. At pH x, the reaction is slowest. The rate increases as the pH increases up to pH y, after which the rate begins to decrease again. This indicates that pH y is the optimum pH for the reaction. This means that catalase requires an acid/neutral/alkaline medium. Of course, the pH x and y would be replaced in your discussion by the actual numbers for the appropriate pH. Have fun doing the experiment and use your knowledge to write up the experiment. See you next week!

Monacia Williams teaches at Glenmuir High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

Organic chemistry yl:chemistry

revision

FRANCINE TAYLOR-CAMPBELL Contributor

E WILL attempt a few questions that covers the basic concepts in organic chemistry.

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Question 1. (a) Soaps are the sodium or potassium salts of long chain organic acids. A soap can be represented by the formula HH X—C = C —- COONa where X represents a long hydrocarbon chain. (i) Describe in detail how you would prepare a sample of soap. (ii) Identify one way in which a soap is different from a soapless detergent. (b) When H H reacts with hydrochloric acid X—C = C —- COO Na acid is formed. Write a balanced equation to show what happens in this reaction. (c) Describe what you would expect to observe if H H reacts with (i) bromine X—C = C —- COONa (ii) acidified potassium manganate VII (iii) Write an equation to represent the reaction that should take place if H H reacts with (1) bromine X—C = C —- COONa (2) hydrogen using a nickel catalyst (d) Compounds with formulae like H H X—C = C —- COOCH3 can bond together under appropriate conditions to form a ‘polymer’. (i) Define the term polymer (ii) What type of polymerisation do you expect to occur with compounds in (d) above. (iii) Use two molecules to show how the units are bonded together. (iv) Suggest a possible general name for this polymer based on the functional group present in its formula.

ANSWERS 1. A soap sample can be prepared by

YOUTHLINK MAGAZINE | MARCH 6-12, 2012

boiling fats and oils with concentrated sodium hydroxide solution. (ii) Soaps are formed from vegetable oils and animal fats which are esters. When these are hydrolysed soaps are produced. Soapless detergents are synthetic detergents which are made from the reaction of hydrocarbons with concentrated sulphuric acid then neutralizing with sodium hydroxide to form the sodium salt. One major difference is that soaps do not lather in hard water, that is they form scum readily, while soapless detergents do not form scum in hard water. (b) H H X—C = C — COONa + H H HCl ===X-C = C-COOH + NaCl (c) If H H X— C = C —- COONa reacts with acidified potassium permanganate VII then one would expect it to be changed from purple to colourless that is, it is decolourised. When it reacts with bromine it is also decolourised. (iii) H H X—C = C —- COONa + H H Br2 == X—-C—C—-COONa Br Br The bromine adds across the double bond; an addition reaction. A similar situation occurs with hydrogen. H H X—C = C —- COONa + H2 == H H X—-C—C—-COONa H H (d) Polymer is a macromolecule formed from the linking of small molecules called monomers. The compound is expected to exhibit addition polymerisation and form polymers called polyalkenes. H H H H H H H H C = C C = C = C — C — C — CX Y X Y X Y X Y Let Y = COOCH3 Francine Taylor-Campbell teaches at Jamaica College. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

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MAUREEN CAMPBELL Contributor

AGE-DEPENDENCY RATIO This is the ratio of persons in the ages defined as dependent (under 15 and over 64 years) to persons in the ages defined as economically productive (1564) years in a population.

AGE-SEX STRUCTURE This is the composition of a population as determined by the number or proportion of males and females in each age category. This is usually represented in a population pyramid.

AGEING POPULATION People are living longer as the proportions of adults and the elderly increase in a population, while the proportions of children and adolescents decrease, resulting in a rise in the median age of the population. Ageing occurs when fertility rates decline and life expectancy remains constant or improves at the older ages.

BIRTH CONTROL An accepted practice employed that permits sexual intercourse with reduced likelihood of conception.

BIRTH RATE (OR CRUDE BIRTH RATE) The number of live births per 1,000 in a given year.

BRAIN DRAIN This occurs when a significant proportion of a country’s highly skilled, highly educated professional population emigrates, usually to other countries offering better economic and social opportunities.

DEPENDENCY RATIO

This is the ratio of the economically dependent part of the population to the productive part. It is arbitrarily defined as the ratio of the elderly (ages 65 and older) plus the young (under age 15) to the population of the working ages (ages 15-64).

EMIGRATION This is the process of leaving one country to take up residence in another.

Defined as the average number of years a person could expect to live if current mortality trends were to continue for the rest of that person’s life.

LIFESPAN

This is the cultural practices, language, cuisine, and traditions – not biological or physical differences – used to distinguish groups of people.

MIGRATION

FAMILY PLANNING This term is defined as the conscious effort of couples to regulate the number and spacing of births through artificial and natural methods of contraception. Family planning connotes conception control to avoid pregnancy and abortion.

FECUNDITY

This is the enumeration of the entire population resulting in the compilation of demographic, social and economic information pertaining to that population at a specific time.

FERTILITY

DEATH RATE (OR CRUDE DEATH RATE)

LIFE EXPECTANCY

This is the maximum age that human beings could reach under optimum conditions.

CENSUS

The term is used to describe the reproductive age span of women, usually between 15-44 or 15-49 years of age.

This is viewed as the number of deaths of infants under age one per 1,000 live births in a given year.

ETHNICITY

This is the physiological capacity of a woman to produce a child.

CHILDBEARING YEARS

INFANT MORTALITY RATE

This is the actual reproductive performance of an individual, a couple, a group or a population.

This is the movement of people across a specified boundary for the purpose of establishing a new or semi-permanent residence. It has been divided into international migration and internal migration.

MOBILITY This is the movement of people between different geographical locations.

This is the number of people added to or subtracted from a population in a year. It is due to natural increase and net migration expressed as a percentage of the population at the beginning of the time period.

POPULATION DENSITY A concept used to refer to population per unit of land area. For example, people per square mile or people per square kilometer of arable land.

POPULATION DISTRIBUTION This refers to the patterns of settlement and dispersal of a population in a country due to several man-made or natural causes.

POPULATION INCREASE The total population increase resulting from the interaction of births, deaths and migration in a population in a given period of time.

POPULATION PYRAMID This is a bar chart, arranged vertically, that shows the distribution of a population by age and sex. The younger ages are at the bottom, with males on the left and females on the right.

‘PUSH-PULL’ HYPOTHESIS

SEX RATIO

NATURAL INCREASE (OR DECREASE)

This is the number of males per 100 females in a population at a given time.

URBANIZATION

This is looked on as the surplus or decline of births over deaths in a population in a given time period.

This is the proportion of a population living in urban areas.

NET MIGRATION

‘ YOUNG’ POPULATION

DEMOGRAPHY

This is the process of entering one country from another to take up permanent or semi-permanent residence.

This is the net effect of immigration and emigration on an area’s population in a given time period, expressed as an increase or decrease in the total population.

IMMIGRATION RATE

‘OLD’ POPULATION

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This is viewed as a broad concept that addresses the relationship between fertility, mortality and migration, but is most commonly used to refer to efforts to slow population growth through action to lower fertility.

MORTALITY

IMMIGRATION

This is defined as the number of immigrants arriving at a destination per 1,000 at that destination in a given year.

POPULATION CONTROL

This is defined as the frequency of disease, illness, injuries and disabilities that occurs in a population.

MORBIDITY

This is the number of deaths per 1,000 in a given year.

The term is used to identify scientific study of human populations, including their sizes, compositions, distributions, densities, growth, and other characteristics, as well as the causes and consequences of changes in these factors.

This defined as the process of leaving one location in a country to take up residence in another.

This is a migration theory that posits that circumstances at the place of origin, such as poverty and unemployment, tend to repel or push people out of that place to other places that exert a positive attraction or pull, such as a high standard of living or job opportunities.

Deaths as a constituent of population change.

GROWTH RATE

yl:social studies

OUT-MIGRATION

This is a population with a relatively high proportion of middle-age and elderly persons; a high median age.

YOUTHLINK MAGAZINE | MARCH 6-12, 2012

A term used to describe a population with a relatively high proportion of children, adolescents and young adults. There is a low median age, high fertility and, therefore, a high growth potential. Maureen Campbell teaches at St Hugh’s High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

Persuasive writing yl:english language

part 4

NATASHA THOMAS- FRANCIS

Contributor

c. Quote two words or phrases which indicate that the writer is distressed? (2 marks)

ELLO, ALL. This week we are continuing our discussion on persuasive writing. Over the last few weeks we have looked at techniques/devices which you should employ in your writing, as well as the steps involved in producing a persuasive piece.

Any two - doomed to disappointment, standing for an eternity, fellow-sufferer, humiliation, disgruntled.

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In this week’s lesson, I wish to give you a checklist for evaluating your arguments then focus on the instructions specific to presenting them. Before we go into that aspect of the lesson, however, I want to share with you the possible answers for the questions set on the letter to the editor which I gave you in last week’s lesson. a. What is the writer’s main purpose in this letter? (2 marks) The writer’s main purpose is to complain about and criticise the poor customer service he received at the newly renovated tax building. b. State what is suggested by the writer’s use of each of the following words: (i) ‘waltzed’ (line 1) (2 marks) This word suggests that the writer walked into the tax building with a high level of expectation that his experience would have been a positive one; he was excited to enter the building. (ii) ‘extorts’ (line 14) (2 marks) This word suggests that the government forcefully and unfairly takes exorbitant amounts of money from taxpayers.

d. What did the writer mean by “Thank you for being so kind”? (line 12) (2 marks)

m Have you used appropriate language structures to connect your ideas? m Have you summarised your main arguments in a conclusion? m Have you checked carefully for errors in grammar, usage and mechanics?

He is being sarcastic. He is not at all grateful for the rude response he got from the lady at the Information Desk.

Use the checklist as a guide, especially when developing your writing skills, and keep the checklist in mind when you are writing the exam.

e. ‘The more things change, the more they remain the same.’ How is this view presented in the letter? (2 marks)

Let us now focus on the kind of instructions which CXC will give you in the exam.

Although the tax building is new, the poor service from the agents has not changed.

QUESTION INSTRUCTIONS

Were your answers similar to mine? I’m sure they were! Let us turn our attention now to the following: Below is a checklist for evaluating and revising your arguments. Pay close attention to these points when writing your argument:

CHECKLIST

m Does your essay clearly express your position on the topic or issue? m Is your position supported by reasons? m Have you used supporting evidence for each reason? m Are your reasons arranged in an effective order?

You will need to thoroughly discuss your position on a specific topic/issue. CXC may ask you to do one of a number of things: Write an argument either supporting or opposing an issue. example 1: “The right contacts and a large amount of luck are all you need to succeed in life.” Write an argument either supporting or opposing this view. example 2: Speaker A: I am going to start eating more local food because that is what makes our Caribbean Olympic athletes stars. Speaker B: Nobody is going to get me to eat yams and sweet potatoes. That is backwardness. Write an essay supporting the views of either Speaker A or Speaker B and justify the kind of food that you prefer to eat. Please note that in the example above, you are required to choose one side. You must decide on the side for which you can present the stronger arguments. Write an argument in which you present your views. With this kind of question you are permitted to present both sides of the issue. example 1: Write a letter to the editor expressing your views on the following. “Adults who smoke cigarettes and drink alcohol are hypocrites when they condemn young people for using marijuana and cocaine.” example 2: “School is not the place for bullies. They should be put into special institutions.” Write an essay giving your views on this statement.

BARRINGTON FLEMMING PHOTO

Now that you are armed with the necessary tools to build your

The Universitry of the West Indies Open Campus Events Management Group recently hosted a party for charity. arguments, attempt at least one of the essays listed above for Here Event Manager Yvonne Thomas (right), a member of the class, makes the presentation of a cheque valued at homework. Until next week, blessings! \$285,000.00 representing the amount raised by the group to Mrs Adama Blagrove, founder of The Montego Bay Autism Centre which was chosen as the beneficiary. Sharing in the special moment are Valerie Cooper (left) and Lori- Natasha Thomas-Francis teachers at Glenmuir High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com Ann Bingham, teachers at the centre. YOUTHLINK MAGAZINE | MARCH 6-12, 2012

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SAY

BERYL CLARKE Contributor

N PAPER 02 of your external examination, you will be writing three responses to questions and I think that it is time for us to look at some of the terms which are frequently used in questions. In fact, I regret that you were not given these before.

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COMMENT This means that you should give a judgement or opinion about something. You could be asked to comment on the importance of dreams in Shakespeare’s A Midsummer Night’s Dream.

COMPARE Tells you to examine (look closely at) or judge one thing against another to show how they are the same. For instance, you may be asked to - Choose TWO books and compare how a major character in EACH is affected by his upbringing.

FYI

EXPLAIN

This means to make something clear and easy to understand. In explaining you must organise your ‘facts’ logically.

GIVE

CONSIDER

This is simply asking you to supply or share information as required.

This advises you to think about a situation carefully; that is, to examine all the facts of a situation before coming to conclusions.

HOW

CONTRAST

This is used when you are stating the way in which something happens.

Here the question requires that you examine or judge two people or things in such a way that their differences are made clear.

DESCRIBE You are asked to say what someone or something is like. You would explain and give illustrations. Describe the opening scene of the play would demand that you say what the setting is, what is on the stage, how the characters dress, how they relate to each other, what is their physical appearance and so on.

DISCUSS This is to talk or write about details of something with someone else, that is, to share your ideas about something/anything in an organised manner. A question such as discuss what these difficulties reveal about the characters involved in the relationship requires you to align the action/reaction of the one facing the difficulty with the difficulty in order to see whether the person panics or deals calmly with the situation. This is how you can decide on the person’s character.

IDENTIFY This asks you to recognize and name someone or something.

OUTLINE Share the main ideas or facts of something with no details.

REFER This requires that you give an example or make a remark mentioning or giving information about someone or something. You must, in other words, supply direct and precise information. If you are asked to make close references or refer closely, you are to give examples directly from the text.

PRESENT Give information or show someone’s character to people in a formal way.

yl:english literature

To express something about someone or something.

SHOW To allow or cause something to be seen.

STATE To say or express.

Beryl Clarke is an independent contributor. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

RUDOLPH BROWN/PHOTOGRAPHER

Chairman of Continental Baking Company Gary Hendrickson (centre), National Baking Company’s Director of Operations Steven Sykes (right) and Sharon Ffolkes-Abrahams (second left), state minister for Industry, Investment and Commerce, join representatives of companies selected as the Bold Ones for 2012 in front of a trailer advertising Crayons Count. Crayons Count is an early-childhood education project endorsed by Hendrickson. Looking on are (from left) Denese Palmer of Southside Distributors; Heneka Watkis-Porter of Patwa Apparel; Suzette Thomas of Sue Tru; Deika Morrison, founder of Crayons Count; Cinderella Anderson of Visionaries; Robin Lumsden of Belcour Preserves and Dehand Kelly of Visionaries (partially hidden).

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YOUTHLINK MAGAZINE | MARCH 6-12, 2012

Effects of industrialisation on British Caribbean women yl:history

DEBBION HYMAN Contributor

AT THE end of the lesson, you should be able to: 1. Assess the economic effects of industrialisation on women. 2. Evaluate the social effects of industrialisation on women. Women, like men, were caught up in the economic changes that took place in the British Caribbean in the 20th century, but at times their experiences were different because of their gender. One immediate difference was that women’s participation in the wage labour force as estate labourers declined. It remained significant in places like Barbados where, in 1911, 77 per cent of the women were in the estate labour force. However, by 1960 this had declined to 37 per cent. In some cases, this decline in women’s participation in the plantation labour force was because of new gender ideologies which favoured men as workers in the ‘public domain’ because women wanted to be full-time housewives, and because of immigration. In other cases, women

chose to withdraw from estate labour to explore other occupations.

Most of these women remained in agriculture, but as peasant farmers and small farmers who participated in the local export markets. Many who remained as wage labourers shifted from sugar estates to cultivate other crops like coffee, cocoa, banana, rice, etc. Some left rural areas for urban centres where they were involved in domestic service and petting trading, or they found jobs as wharf/port workers, coal carriers, laundresses and seamstresses. Women dominated the domesticservice sector because employers preferred them in an occupation which was seen as ‘women’s work’. According to Rhoda Reddock, women made up 89 per cent of a total of 24,274 domestic workers in Trinidad and Tobago in 1931. As educational opportunities expanded for women, some qualified themselves to enter the professions and the civil service. However, their numbers in the professions always lagged behind the number of men in such areas.

In World Wars I and II, women broke out of gender confines and worked in jobs traditionally seen as being for men, who had gone off to fight. The new thrust towards industrialisation and manufacturing after World War II gave women yet another outlet for their work skills. Indeed, during the latter decades of the 19th century and the start of the 20th, the industrial and manufacturing sectors were the second-largest employers of women. They employed some 80 per cent of the female working population. In 1946 in Barbados, 7,400 or 18 per cent of the total female working population were employed in the manufacturing sectors, though by 1960 this had declined to 12 per cent. Women were important in the textile and garment-manufacturing industries. In the late 19th and early 20th centuries, garment production was totally controlled by small producers. In Trinidad, dressmaking engaged 95 per cent of women, and in 1911 there were 13,000 seamstresses who worked in their homes. Girls in the early 20th-century Caribbean were trained at home in needlecraft. As a result, a pool of skilled and semi-skilled labour was available for these industries.

CORRECTION

PHOTO NOEL THOMPSON

Marlene Burrowes (centre), managing director of Dolphin Cove Attractions, is tickled pink with her conversation with Damion Crawford, state minister in the Ministry of Tourism and Entertainment and Carole Guntley, the director general. Occasion was a tourism stakeholders’ meeting held at the Sandals Grande Ocho Rios Beach and Villa Resort in St Ann on Thursday, February 16. YOUTHLINK MAGAZINE | MARCH 6, 2012 MARCH 6-12, 2012

1. Immigration of labour to the British colonies resulted in all of the following except a) A constant labour shortage b) The continuation of monoculture c) The continuation of slavery conditions d) A greater racial mixture of the population Debbion Hyman teaches at St Hugh’s High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

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Market structures

YVONNE HARVEY Contributor

HIS IS the last section in our lesson on market structures. As promised, it will cover monopolistic competition and oligopoly.

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MONOPOLISTIC COMPETITION This describes an imperfect market structure in which there are relatively large numbers of producers offering slightly differentiated products.

CHARACTERISTICS/FEATURES OF MONOPOLISTIC COMPETITION 1. A relatively large number of sellers This makes the market highly competitive. In addition, each firm’s market share is small and collusion (coming together to act as a monopoly in order to gain more profits) is difficult. 2. Independence Each firm acts independently of the other. That is, no firm takes into account the reaction of its rival firms. 3. Freedom of entry into the market and exit out of the market In the long run, firms will enter and leave the industry due to the lack of significant barriers to entry.

more obvious. Through entry of new firms and exit of some existing ones, profit will tend towards normal in the long run for all the firms in the industry. We will now move on to yet another market structure.

OLIGOPOLY Oligopoly refers to a market structure in which a few firms dominate the industry, in the sense that between them they share a large proportion of the industry’s output. Some oligopoly firms produce virtually identical products, for example, metals, chemicals, sugar. These are known as perfect oligopolies. Likewise, some produce differentiated products, for example, cars, soap powder, cigarettes, electrical appliances. These are known as imperfect oligopolies. Duopoly is a special form of oligopoly in which there are only two firms in the industry.

CHARACTERISTICS/FEATURES OF OLIGOPOLY 1. There are only a few firms in the industry. With

only a few firms in the industry, each is big enough to influence price. Firms are, therefore, price makers/price fixers. 2. Interdependence of firms. Since there are only a few firms in the industry, each firm will have to take into account the actions of rival firms in the industry. For example, if one airline announces discount fares, generally, all the other airlines will try to match the lower prices.

3. The product is either identical or differentiated. Where the product is identical, there is no need for advertising or non-price competition. However, if the product is differentiated, advertising and nonprice competition will take place in order to make consumers believe that one brand is better than the other. 4. There are barriers to entry. These barriers may not be as strong as the barriers for the monopolist but the effect is still the same. Barriers will make it virtually impossible for others to enter in the long run. 5. Prices tend to be stable. This is because firms realise that decreases in price can lead to ‘price

PROFITS IN THE SHORT RUN Like the monopolist, many oligopolistic firms will earn supernormal profits in the short run.

LONG RUN If the barriers to entry are strong, supernormal profits will be maintained. Where a firm was earning less-than-normal profits in the short run, it will leave the industry in the long run. Now for your practice questions. (a) Define ‘monopolistic competition’ and ‘oligopoly’. (4 marks)

(c) Give two examples of oligopoly industries and two examples of monopolistic industries in the Caribbean. (4 marks) (d) “A monopolistic firm is earning supernormal profits in the short run.” What do you understand by this statement? (2 marks)

6. Firms are price makers/fixers Their demand curve is downward sloping and it is also fairly elastic because of the relatively large number of firms in the industry.

(e) Assume that firms under monopolistic competition and oligopoly are earning supernormal profits in the short run: (i) How will their long-run profits differ? (ii) Give reasons for the differences in their longrun profits. (4 marks) Total marks: 20

Examples of monopolistic competition in the Caribbean: hairdressers, restaurants, taxi drivers and gas (petrol-filling) stations.

SHORT-RUN PROFITS The short-run profits situation is similar to that of the perfect competitor. It is possible to earn supernormal profits. Subnormal and normal profits are also possible.

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7. Oligopolies may price discriminate in order to earn more profit.

(a) above, under the following headings: (i) the number of firms in the industry (ii) the existence or non-existence of barriers to entry (iii) type of product (6 marks)

5. Advertising takes place Each seller seeks to increase brand loyalty for his/her product and, thereby, increase profits.

In the long run, the similarity between perfect competition and monopolistic competition becomes

6. Firms may be collusive or non-collusive. When they are collusive they may, for example, formulate an agreement to set prices for everyone at a certain level.

(b) Compare the market structures named in

4. The product is differentiated Each individual seller has a product which is slightly different from that of the other producers. This product differentiation is mainly through brand names, but it can also be through physical and chemical differences.

LONG-RUN PROFITS

wars’ and they can end up losing so much profit that they are eventually driven out of the industry. They also know that raising prices will be of no advantage to them since others will not copy them.

This completes market structures. I urge you to do some reading on the topic. You will find some interesting facts if you consult texts in economics.

Minister of Youth and Culture Lisa Hanna (centre) poses with the the Under-20 Reggae Girlz and officials at the Jamaica Football Federation headquarters recently prior to the team’s departure to Panama for the Confederation of North, Central American and Caribbean Association Football stage of World Cup qualifiers. YOUTHLINK MAGAZINE | MARCH 6, 2012 MARCH 6-12, 2012

See you all next week. Bye for now. Yvonne Harvey teaches at Glenmuir High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

Top-down design & programming languages S yl:information technology

m Execution is faster than high-level languages.

NATALEE A. JOHNSON

Contributor

TUDENTS, THIS is lesson 25 in our series of Gleaner IT lessons. In this week’s lesson, we will look at modularity/top-down design and programming languages (the beginning of a new unit).

USE OF THE TOP-DOWN DESIGN APPROACH TO PROBLEM SOLVING

PROGRAMMING LANGUAGES

Programming languages fall into the following categories: m Machine Language/ 1st Generation m Assembly Language/2nd Generation m High-Level Language/3rd Generation m Fourth-Generation Language

You have learnt the way in which you solve a problem on the computer in previous lessons, and you have been learning thus far how to write your pseudocodes and how to construct your flow charts. Now you are going to learn about a technique that can be employed when you have a big program to code or problem to solve. This method is called the ‘Top-down Design Approach to Programming’.

These languages can be further categorized as either being low-level or high-level languages.

WHAT IS TOP-DOWN DESIGN?

LOW LEVEL

The Top-down Design Approach, or Modular Programming as it is sometimes called, involves breaking a problem into a set of smaller problems, called sub-problems or modules, followed by breaking each sub-problem into a set of tasks then breaking each task into a set of actions. This is called a ‘divide and conquer’ approach. When faced with a complex problem, it is easier to break the problem down into smaller, more manageable sections and tackle each section as a separate entity rather than trying to solve the large problem in one go.

m Machine Language m Assembly Language

HIGH LEVEL

m High-Level Language m Fourth-Generation Language

m Programming is slower and more tedious than high-level languages. Code is machine specific.

HIGH-LEVEL LANGUAGE This differs from low-level languages in that it requires less coding details and makes programs easier to write. It is closer in appearance to natural language, for example English and French. Programs written in high-level language are called Source Code while the translated version is called Object Code. These programs must be translated to a form which can be accepted by the computer. This is achieved by means of special translator programs called compiler and interpreter. Here’s a diagram illustrating the relationship between the source code and the object code. In contrast to a compiler, an interpreter does not translate the whole program prior to execution. Rather, it translates the code, line by line during the execution of the program. With the compiler, all the translation is done and then the object program is executed. It is not machine dependent. Examples of High-level Language are Basic

Let us now examine each of these languages. Below is a diagram depicting a typical top-down design or modularity approach to programming.

MACHINE LANGUAGE This was the first language available for programming. At the machine level the instructions are written in ones and zeros (binary digits). This is the only language that the computer understands.

m Programs execute fast m Efficient use of memory

As you may observe with the diagram above, there is a major problem which has been broken down into two sub-problems. The sub-problems are then broken down into respective tasks for which specific action(s) will be carried out. A sub-problem is a set of related tasks. A task is a set of related actions. An action is a basic instruction that needs no further refinement. For example, an action might be a simple instruction such as subtract two numbers. The process of dividing the problem into sub-problems or modules and breaking them down into smaller units is called stepwise refinement. One advantage of modular programming is that when a problem has been decomposed into smaller sub-problems, each sub-problem can be solved as a single entity. However, the solution of each individual sub-problem does not necessarily solve the larger problem. There must be cohesion between the modules, meaning there must be a mechanism for communicating between the different sub-problems.

(Beginners All-Purpose Symbolic Instruction Code), Pascal (which is the programming language you will learn for CSEC), COBOL (Common Business Oriented Language), JAVA, C Programming and so on.

m Programming is faster and less tedious m Code is easier to learn, read, understand and correct m Language is more English and math like.

m Programming is slow and tedious m Code is difficult to learn, read, understand and correct m Code is machine specific, meaning it cannot be used in the same form on other computer models

ASSEMBLY LANGUAGE

FOURTH GENERATION

This was developed to replace the zeros and ones of machine language with symbols that are easier to understand and remember. It uses special codes called mnemonics (words that suggest meaning) to represent machine language instructions. For example: m MOV represents Move m Hlt represents Stop An assembly language is translated into a machine language by using a translator program called an assembler. However, both languages are machine dependent, that is, the way the program is written depends on the operation of the computer.

m Programming is faster and less tedious than for machine language m Code is easier to learn, read and understand, than for machine language YOUTHLINK MAGAZINE | MARCH 6-12, 2012

m Program executes slowly

These are often described as very high-level languages and referred to as 4GLs. They are easy-to-learn, easy-to-use languages that enable users or programmers to code applications much more quickly than they could with lower-level languages. Two examples of 4GLs are DBASE and FOXPRO.

m Useful for generating reports

m Can be very wordy

We have come to the end of lesson 25. See you next week when we will look at some key programming terms and the Pascal language. Remember, if you fail to prepare, prepare to fail. Natalee A. Johnson teaches at Ardenne High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

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Partnership

yl:principles of accounts

ROXANNE WRIGHT Contributor

ARL AND Cleon are in partnership. Their agreement provides that the partners are to receive interest on capital at 8% per annum. All remaining profits/losses are to be shared by Carl and Cleon in the ratio 3:2, respectively.

C

The following balances were taken from the books of the partnership on August 31, 2011.

ADDITIONAL INFORMATION 1. Stock on August 31, 2011, was valued at \$39,600. 2. Insurance amounting to \$440 had been paid in advance. 3. The selling expenses included an item of \$600 for carriage on purchases [>1] 4. It was decided to write \$4,000 off the Goodwill. [>2] 5. Rent amounted to \$4,800 per annum. No payment had been made for the month of August, 2011. 6. Furniture and fittings are to be depreciated at 20%.

YOU ARE REQUIRED TO: a. Prepare the partnership Trading Account, the Profit and Loss Account and an Appropriation Account for the year ended August 31, 2011. b. Prepare the Current Accounts of the partners, balances at August 31, 2011. c. Draw up the Balance Sheet as at August 31, 2011.

REASONING [>1] Carriage on purchases is added to purchases amount in the Trading Account. [>2] Goodwill written off is charged to the Profit and Loss Appropriation Account.

EXAMINATION PREPARATION TIP As you get closer to your examination, to assist with your preparation I encourage you to keep your parents and families updated on what you and your study team are doing. They worry about you, especially when they are not sure how you are coping and progressing. This is the best time to bond with them; they want to support you as much as they can.

Roxanne Wright teaches at Immaculate Academy. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

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YOUTHLINK MAGAZINE | MARCH 6-12, 2012

(b) - everyone has easy access to the cabinets - workers will have it easier to communicate 4.(a) (see form at bottom of page)

(b) Give the name of your school, address, telephone and email address. You may also include the principal and chairmanâ&#x20AC;&#x2122;s name. The school crest should be strategically placed so that the heading looks well-balanced on the page. 5.(a) - the organisation stands to lose business/clientele - the organisation will lose assets if money was borrowed from a financial institution

HYACINTH TUGMAN Contributor

AST WEEK I gave you an assignment. I hope that you were able to find the time to answer the questions. I will give you some possible answers to them now.

L

1. Draw an organisation chart of your school. (See chart above) 2. Skills required for (a) A telephone operator must: - be pleasant and patience - maintain good working relationships with all persons he/she comes across - operate companyâ&#x20AC;&#x2122;s switchboard

(d) A records management clerk must: - be able to use computer software applications to maintain a database of records - be able to maintain good working relationships (e) A human resources clerk must: - use basic computer software applications - have knowledge of labour laws, health and safety requirements - maintain good working relationships 3.(a) - more difficult to communicate with other workers - managers and supervisors may not always be aware of what is happening in these offices

(b) - ring back the other party immediately and genuinely apologise for the disruption during your conversation. At the end of the conversation, make another short apology and thank the party for his/her time.

MULTIPLE CHOICE (1) A; (2) A; (3) B; (4) B; (5) C; (6) D; (7) B; (8) C; (9) C; (10) D; (11) B; (12) A; (13) D I hope you were able to maximise the marks on each question. Until then, see you next week. Hyacinth Tugman teaches at Glenmuir High School. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

(b) A data entry clerk must: - have the ability to type fast accurately - be able to format basic documents - be able to use specialised computer software application - maintain good working relationships (c) An administrative assistant must: - have skills in numeracy and literacy - use basic software application - maintain good working relationships - be able to type accurately - maintain office files

YOUTHLINK MAGAZINE | MARCH 6-12, 2012

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MARJORIE HENRY Contributor

REETINGS TO you all, my readers! For those of you who are sitting the external examinations this year, I do trust that your preparations have been going well. The examinations are but a few short weeks away and, as the saying goes,’If you fail to prepare, prepare to fail’. I feel certain that your goal is to be successful in the examinations and you are aiming at realising this. I hope you have done a study timetable as this will help you to manage your time. Spend extra time on your weaker subjects. Most, if not all, schoolbased assessments should be completed by now, giving you some time to complete the syllabus for the examinations. Work well and remain focused.

G

In an earlier lesson, I had indicated that I would share with you some information on selected topics taken from Section II, Natural Systems, of the geography syllabus. My source of information is the available textbooks. I have already shared with you on crustal plates, a topic from internal forces. This week I will move on to external forces – forces that are constantly affecting the surface rocks. By way of introduction to the topic, here is some information on graduation, taken from Geology Made Simple, written by William H. Matthews. The surface rocks of the Earth are constantly being affected by ‘gradational’ forces. For example, the atmosphere attacks the rocks, weathering them both physically and chemically. In addition, the rivers and oceans of the hydrosphere are continually wearing away rock fragments and transporting them to other areas where they are deposited. Gradation, then, includes two separate types of process: degradation, which is a wearing-down or destructive process, and aggradation, a building-up or constructive process.

External forces

Degradation, commonly referred to as erosion, results from the wearing down of the rocks by water, air and ice. It includes the work of atmospheric weathering, glacial abrasion, stream erosion, wind abrasion and so on. Aggradation, known also as deposition, results in the accumulation of sediments and the ultimate building up of rock strata. The principal agents depositing these sediments are wind, ice and water. In reference to the geography syllabus, the specific objectives relating to external forces are: m Define denudation, weathering, mass wasting and erosion m Explain the processes of weathering m Describe landslides and soil creep and the conditions which influence their occurrence.

I will now share some information on the first objective listed above. For these definitions, I will quote extensively from the text Geography for CSEC, written by Nelson Thornes.

yl:geography Denudation simply means the wearing away of the land by weathering and erosion. It includes all natural agencies, for example sun, rain, frost, wind, rivers, sea, ice, temperature change, and even the actions of plants and animals. This set of major processes is responsible for the creation of the Earth’s varied landscape. Weathering is the wearing away (disintegration and decomposition) of rocks by the effects of the weather and the atmosphere. No movement is involved in this so the breakdown of the rock is said to be in situ – in other words ‘in that place’. Sometimes, after the breakup of the rock, fragments are moved but only by gravity, for instance slipping down a slope. Mass wasting or mass movement follows weathering. It is the downhill movement of rock debris and soil due to the force of gravity. Water acts as a lubricant making the debris more slippery and easy to move. Erosion: Water, ice and wind also wear away the Earth’s surface. Water can mean either rivers or the sea. Ice is in the form of glaciers. Wind erodes, especially when it is carrying something to help it wear away rock, usually sand. May I encourage you to refer to other textbooks for additional information on these terms. Make sure you understand each of them. You are often asked for definitions in the examinations. In the next lesson, I will share information on the third objective listed above, referring to landslides and soil creep. Marjorie Henry is an independent contributor. Send questions and comments to kerry-ann.hepburn@gleanerjm.com

IAN ALLEN/PHOTOGRAPHER

Members of G2K Youth Group of East Kingston and Port Royal Chapter tried to rid the beaches of Port Royal of plastic bottles and other waste that wash up on the shores.The Youth Group was having a beach clean-up and fish fry to raise funds for their candidate in the Springfield division. 22

YOUTHLINK MAGAZINE | MARCH 6-12, 2012

CSEC Study Guide - March 6, 2012

RUDOLPH BROWN / PHOTOGRAPHER YOUTHLINK MAGAZINE | MARCH 6, 2012 MARCH 6-12, 2012 11