Movie Analysis North Country Essay Example

Movie Analysis : North Country Paper The movie North Country was based on the book †Class Action: The Landmark Case That Changed Sexual Harassment Law† which tells the story of Lois Jenson, who filed the first class action lawsuit for sexual harassment in American history. In the film, Theron plays the daughter of an iron miner (Richard Jenkins) working in a mine in Northern Minnesota Mesabi Iron Range. When Josey leaves an abusive husband and moves back to her hometown into her parents’ house, she was not welcomed. Her father assumes, without even interrogating his daughter, that it was her infidelity to her husband that had created the situation. Even her own son thinks that she is a whore. What this shows is the tendency to assume that it’s the woman’s fault in any conflict with men. Such biases were more prevalent in the chronological setting of the film, which covers the last few decades of the 20th century (Rosen). All Josey wants is to own a house, eat decent meals and be able to buy her son hockey skates once in a while, which are completely reasonable. But even her father Hank expresses his displeasure to women working in the mines, because it’s not â€Å"women’s work†. He also blames Josey of taking away a job from a man on whom a whole family is dependent. But Hank fails to notice that his daughter too has a family to support. Even the women in the community believe there’s something wrong if she can’t find a man to take care of her. It points to the common acceptance in society, which is women’s dependency and subordination to men (Ebert). We will write a custom essay sample on Movie Analysis : North Country specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Movie Analysis : North Country specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Movie Analysis : North Country specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The most gripping scene in Niki Caro’s off-the-beaten-track drama â€Å"North Country† comes when the lead character, Josey Aimes (played by Charlize Theron) addresses her hostile co-workers at the union meeting to make clear that she does not want the mine closed down, but only the sexual harassment of women to stop (Ebert). Women were as much complicit to such abuses as is evident from the fact that the other female co-workers of Josey choose to bear the humiliation rather than risk losing their jobs. Women felt helpless, in spite of the protection provided by law. This goes to show that the rights granted to citizens of the country as a result of the civil rights movement had still not managed to uproot the patriarchal nature of the society. This is as truer in the 21st century as it was true during the century before. What had decreased is the prevalence and institutionalization of such attitudes and beliefs. Like the court’s decisions on civil rights, it didn’t change everything overnight. Affirmative action was enforced in the Iron Range as late as 1974, when the government finally ordered the steel companies to reserve 20% of their jobs to women and minorities. (Ronning) When Josie takes up a traditional women’s job of a hairdresser, she could earn only a sixth of what she will eventually earn as a miner. This shows the disparity in wages between the two sexes. Women generally don’t get paid as much as men for the same amount of work they do. Another disparity is in the composition of the work force in the mines. Men outnumber women 29 to 1, which is highly disproportionate to the actual population figures. Yet, the ones who do make it through and got the job cannot consider themselves lucky as they were subject to all kinds of sexual harassment by their male co-workers for no fault of theirs. The other women miners are hard-working survivors who tolerate the obscenity and worse, and keep silent because they cannot afford to lose their jobs in trying to make a point (Rosen). During the period when the movie was set, Anita Hill was shown testifying against Clarence Thomas for sexual harassment. What this signifies is the permeation of such beliefs and practices across all layers of the society, including the political offices. The movie showcases the approach and expansion of a legal frontier (Rosen). In the male dominated work environment of the mine, picking on women is all in a day’s work. A woman operates a piece of heavy machinery unaware that a sign is painted on it advertising sex for sale. They find obscenities written in excrement on the walls of their locker room. When finally the union decides to ask for portable toilets for the women, one of the first women to use one has it turned over while she’s inside. Add to that other sorts of touching and fondling, but if a woman is going to insist on having breasts, how can a guy be blamed for copping a feel, goes the logic. It is assumed and widely gossiped that Josey is a tramp, and she is advised to â€Å"spend less time stirring up your female co-workers and less time in the beds of your male coworkers.† (Ronning) The patriarchal nature of the American society in the 20th century is evident from the fact that the retired judge named special master to oversee the trial and to decide the compensation amount to the women, had his own biases. He held traditional beliefs and had a history of sexual misconduct. It was also reported that he frequently fell asleep during the testimony and seemed to enjoy the narrations of harassment when awake. Eveleth Mines’ lead counsel during this phase was a woman, and yet she verbally assaulted the plaintiffs to get the damages reduced. Her strategy involved proving that the harassment was the making of the women themselves due to their provocative behavior towards male coworkers and the plaintiffs were dishonest about the severity and the psychological effects. What this shows is the degree to which women themselves were inculcated to believe in their unquestioning subordination to men (Mishkind 147). Overall, Lois and the other women went through three humiliating trials where their character and personal lives were assaulted over and over again by Eveleth’s lawyers. In addition, they endured the torturous process of litigation, and further torment of the federal court system. The appeals court Judge Donald Lay wrote, â€Å"It should be obvious that the callous pattern and practice of sexual harassment engaged in by Eveleth Mines inevitably destroyed the self-esteem of the working women exposed to it. The emotional harm, brought about by this record of human indecency, sought to destroy the human psyche as well as the human spirit of each plaintiff. The humiliation and degradation suffered by these women is irreparable. Although money damage cannot make these women whole or even begin to repair the injury done, it can serve to set a precedent that in the environment of the working place such hostility will not be tolerated.† (Belton) The status and rights of women during the last century was largely only in paper. Only when Anita Hill testified against Clarence Thomas in October l991, did the United States finally wake up to the reality of sexual harassment. Before that landmark event, few people knew what to call such persistent predatory behavior as it was accepted the norm. If women needed to earn a living, they were expected to grit it out and take it. The idea that sexual harassment could be viewed as a violation of a woman’s civil rights and her ability to earn a living was very slow to catch up with the public (Mishkind 142). The much more fair and balanced sexual harassment policies that we see in corporations and educational institutions today owe in large part, to Lori Benson’s determination to put an end to some of the most shameful sexual harassment ever described in print. Although she had to wait for another 10 years to achieve justice, the suit eventually became the cornerstone of modern sexual harassment law. The much liberated women of the 21st century enjoy their freedom and security due to the perseverance and patience of these women (Belton). Works Cited: Belton, John., American Cinema/American Culture (second edition), McGraw-Hill New York. Ebert, Roger., North Country Review, October 21, 2005. Mishkind, Charles S. â€Å"Sexual harassment hostile work environment class actions: is there cause for concern?.† Employee Relations Law Journal 18.n1 (Summer 1992): 141-147. Rosen, Ruth., Behind â€Å"North Country†, Ronning, G., â€Å"Jackpine Savages: Discourses of Conquest in the 1916 Mesabi Iron Range Strike†, Labor History, Vol. 44, No. 3, 2003

Great Gatsby - Summary of Chapter V essays

Great Gatsby - Summary of Chapter V essays In the night Nick comes home from the meeting with Jordan. Gatsby passes by and asks Nick if he wants to go swimming in his pool. But Nick refuses the offering because he is too tired. In their short conversation they talk also about the invitation of Daisy. They agree on the day after tomorrow. Nick invites Daisy for tea the following day and asks her to come alone. At the day of the meeting Gatsbys gardener cuts Nicks lawn and a greenhouse delivers flowers. At three oclock Gatsby comes over looking exhausted and pale. Nick and Gatsby talk a bit and Gatsby is about to go home as Daisy arrives at four oclock. Entering the living room with Daisy Nick notices that Gatsby is gone. Gatsby knocks a few moments later on the front door and is lead in the room by Nick. Daisy and Gatsby are embarrassed by the presence of each other and they dont really start a conversation. After a tea in a tense atmosphere Nick leaves them alone. When he comes back both are in a happy mood but Daisy seems to have been in a sad mood before. They decide to go over to Gatsbys house, because Gatsby wants to show her his enormous house. Ending up in the bed room Gatsby tells them that he has got a man in England who buys him clothes. Daisy is very fascinated by his great collection of shirts. Gatsby urges Klipspringer to play the piano. According to Nick Gatsby finds out that Daisy does not come up to his dreams. ...

International business MOVIE REVIEW Example | Topics and Well Written Essays - 750 words

International business - Movie Review Example The American population has a record of making quite a huge size of garbage every year that amounts to about 250 million tonnes. The garbage is made up of fruit peels, bald tires, soda cans, frozen food container, etc. The size of the garbage produced is quite big and shocking. Whatever happens with the garbage produce is a subject that ‘Trash Inc: the secret Life of Garbage’ mainly undertakes. This documentary runs for one hour and is aired by CNBC on Wednesday. Carl Quintanilla is the documentary’s host and also known to be an Emmy award winning reporter. A big part of Quintanilla summer is seen through the documentary to be spent wading through garbage from Nevada, Pennsylvania to New York. Quintanilla also visits Beijing and Hawaii in the search of knowledge on garbage handling. Quintanilla tries to find out who handles garbage and what environmentally and economically is at stake. From the documentary, Quintanilla report indicates that garbage is both an oppo rtunity and an epidemic. The garbage industry is estimated to worth $52 billion in a yearly basis. This industry is also considered not be a one-size fit all. Most of America’s garbage is picked and transported to 2300 landfill within America. These landfills at the end make some huge profits towards their operators as some also capitalize on the landfill by piping out trash gas. The trash gas is mainly used within factories in the generation of electricity. Apex within Las Vegas is considered to be the largest landfill within the United States, and ‘Trash Inc.’ makes a visit there to know the operations of landfills. From Apex, the next trip is to Beijing which gives an opposite side of the story. Within Beijing, there are hundreds of dumps which are all illegal cropping up on the outskirts of the city. This dump sites are used to handle the high number of garbage that is produced by the

Sustainability Assignment Example | Topics and Well Written Essays - 750 words

Sustainability - Assignment Example Sustainability is about the balance between the humans and nature. It creates and maintains the conditions for the future generations. It is vital to ensure such resources as the water, materials to be preserved and protected for human health and at the same time, thinking about the environment. Rapid population and economic growth and the consumption of the natural resources created unintended conditions (social, environmental, and economic), under which there is no alternative to sustainable development (Sustainability information, n.d.). These are the main reasons why sustainable development is so important. It is the part of a bigger picture, which means preserving of biological diversity, development and stewardship of the  renewable resources and ecosystems. The absence of sustainable practices will lead the world to the peak of fuel production that will be in ten- twenty years. After that period, fuels reserves will be harder to discover and extract. Beside the possible ener gy crisis, the food provision also calls a certain concern, because sustainability in the face of growing population in the world, especially in the undeveloped countries, requires serious thinking. The majority of new births in such countries cannot support the enhanced population and the food production as well. Non-sustainable practices that concern the environment influence the soil erosion and pollution of the surrounding. Because of climate change, some areas become too wet or too dry, affecting the lifestyle of the whole populations. At the same time, the sustainable development practices, such as land and agriculture, aim to improve the effects of reducing land resources. When the unsustainable living practices cause energy crisis, pollute the surrounding causing the lack of water and land resources of proper quality, social decline enhances as well. In this case, sustainability is meant to preserve not only resources make the world a better

Managerial economics Essay Example for Free

Managerial economics Essay 1. If a firm raises its price for Product X, TR will increase. Uncertain, Total revenue = Price Ãâ€" Quantity Sold. The price elasticity of demand tells us there are two eï ¬â‚¬ects, first is price eï ¬â‚¬ect. If price increase, each unit sold sells for a higher price, which tends to raise revenue. Second is quantity eï ¬â‚¬ect. If price increase, fewer units are sold, which tends to lower revenue. This is determines by which price eï ¬â‚¬ect or the quantity eï ¬â‚¬ect is stronger 2. When MR MC, MP (marginal profit) will be positive.  True, for each unit sold, marginal profit equals marginal revenue (MR) minus marginal cost (MC). Then, if MR is greater than MC at some level of output, marginal profit is positive and thus a greater quantity should be produced. 3. If a 10% increase in price leads to a 5% increase in TR, demand must be elastic. False, if an increase in price causes an increase in total revenue, then demand can be said to be inelastic, since the increase in price does not have a large impact on quantity demanded. 4. If the cross price elasticity is positive for two goods X and Y, X and Y must be complements. False, if the goods are complements, the value will be negative because quantity demanded increases when the price of complement falls. Example, if the price of petrol decreases to RM2 a litre, sales of cars would increase. 5. Maximizing TR is never a desirable goal for a firm.  True, profit is the difference between a firms total revenue and its total opportunity cost. Total revenue is the amount of income earned by selling products. But it does not include the total opportunity costs of all inputs into the production process. Hence, it is never a desirable goal for a firm. Firm should consider maximizing Profit instead of TR. 6. The more inelastic the demand, the more likely it is that a firm can have regular price increases. True, if firm have regular increase in price (refer to Appendix 1) from P4 to P5, the decrease in the quantity demanded is relatively small (from Q4 to Q5). It means that, the more inelastic the  demand, the percentage change in quantity demanded is less than percentage change price. Hence, firm can have regular price increases. 7. If EP = -1.25 for Group A, and EP = -.375 for Group B, and a firm uses price discrimination, Group A should pay a higher price than Group B. False, Group A is elastic and Group B is inelastic. The consumers in the inelastic sub-market will be charged the higher price, and those in the elastic sub market will be charged the lower price. So Group B should pay higher price. Please refer to Appendix 2 for illustration. 8. A consumer spends 1% of her income on Good A and 25% on Good B. Price Elasticity of Demand should be greater for Good B. True, if the consumer spends less of her income, means that Good A is a necessity good and spends more of her income means that Good B is a luxury good. Luxuries tend to more elastic than necessities as there are more options for consumer. 9. Income elasticity for an inferior good is always negative. True, because quantity demand falls as income rises. Quantity demanded and income move opposite directions, inferior goods have negative elasticity. 10. The more inelastic the demand, the flatter the demand curve. False, inelastic demand have steeper curve because quantity demanded does not respond strongly to price changes. Please refer to Appendix 3 for illustration. For a inelastic demand product such as cigarettes, when price increase by 10%, the quantity demanded will fall by 3.8%. 11. If demand goes from P = 1850 .05Q to P = 1700 .05Q, Demand has increased. False. If P = 1850 .05Q then Qd= 37000-20P and if P = 1700 .05Q, then Qd= 34000-20P. The demand curve shift to left and hence, the demand decreases. Please refer to Appendix 4 for illustration 12. If TC goes from TC = 1250 + .5Q to TC = 1200 + .6Q, FC have gone up and VC have gone down. False, because TC=TFC+TVC. From the equation above shows that, the FC decreases leads TFC to fall from 1250 to 1200 and the VC increases leads TVC to gone up from 0.5 to 0.6. Part B (Explain in a short Essay (not more than 1 page each)) 1) Define demand, discuss various determinants of demand. Demand is the quantities of good or service that consumers are willing to buy at various prices within some given period of time. Holding all other factors constant, the price of a good or service increases as its demand increases and vice versa. When factors other than price changes, demand  curve will shift. There are 5 determinants of the demand curve. First factor is price of related goods. A good or service can be related to another by being a substitute or complement. If price of a substitute changes, we expect the demand for the good under consideration to change in the same direction as the change in the substitute’s price. For instance, if the price of coffee rises, the demand for tea should increase. The complement goods are the goods that can be used together. Price of complement and demand for the other good are negatively related. Example, if the price of sugar increases, the demand for coffee will fall. Second factor is income, as people’s income rises, it is reasonable to expect their demand for a good to increase and vice versa, the demand curve will shift right. A fall in income will lead to a decrease in demand for normal goods. Goods whose demand varies inversely with income are called inferior goods. Third determinant is future expectation. If enough, buyers expect the price of a good rises in future, the current demand will increase. Also, if consumers’ current demand will increase, they expect higher future income. For example, in 2005 housing prices rose, but people bought more because they expected the price to continue to go up. This drove prices even further, until the bubble burst in 2006 (Stafffullcoll.edu. n.d.). Forth factor is tastes and preferences. This is the desire, emotion, or preference for a good or service. If consumer preference is favorable change will leads to an increase in demand. Likewise, unfavorable change leads to a decrease in demand. Example, companies spend thousands on advertising to make you feel strongly that you want a product. Last determinant is number of buyer. If the number of buyers in market rises, the demand increases. For example, the housing bubble case. Low-cost mortgages increased the number of people who were told they could afford a house. The number of buyers actually increased, driving up the demand for housing. When they found they really couldnt afford the mortgage, especially when housing prices started to fall, they foreclosed. This reduced the number of buyers, and demand also fell. 2) Briefly explain the concept of Law of diminishing returns? Discuss its assumption and importance? The law of diminishing marginal returns means that the productivity of a variable input declines as more is used  in short-run production, holding one or more inputs fixed. This law has a direct behavior on market supply, the supply price, and the law of supply. The main reasons the marginal product (MP) of this variable input declines is the fixed input. The fixed input imposes a capacity constraint on short-run production. For example, in a sandwich production, the size of the sandwich-producing kitchen and equipment is fixed. The company employs additional workers, the kitchen becomes increasingly crowded. Only so many workers can use the sandwich-preparation counter to prepare sandwich. While adding additional workers do increase total sandwich production, the extra production attributable to these workers is certain to fall as the capacity of the fixed input is limited. In fact, adding too many workers actually results in a negative marginal product, hence, total product falls. The law of diminishing marginal returns is reflected in the shapes and slopes of the total product, marginal product, and average product curves. The most important of these being the negative slope of the marginal product curve. Appendix 5 shows the graph three product curves. The total product (TP) curve shows that the total number of Sandwich Company produced per hour for a given amount of labor. The increasingly flatter slope of the TP is attributable to the law of diminishing marginal returns. Also, the marginal product curve indicates how the total production of Sandwich Company changes when an extra worker is hired. The negatively-sloped portion of the MP curve is a direct embodiment of the law of diminishing marginal returns. Further, the average product curve indicates the average number of Sandwich Company produced by workers. The negatively-sloped portion of the AP curve is indirectly caused by the law of diminishing marginal returns. As marginal product declines, due to the law of diminishing marginal returns, it also causes a decrease in average product. 3) Explain the various economies and diseconomies of scale? Economies of scale are the cost advantages that a business can exploit by expanding the scale of production. The effect is to reduce the long run average (unit) costs of production. Economies of scale have brought down the unit costs of production and feeding through to lower prices for consumers (appendix 6). It could be achieved by buying new machinery, and build a bigger factory. There are two types of economy of scale and depending on the particular characteristics of an industry, some are more important than others. Firstly, internal economies of scale are a  product of how efficient a firm is at producing, that is specific to individual firm. Example, advantages are enjoyed by expansion. Next, external economies of scale occur outside of a firm but within an industry. Example, industry’s scope of operations expand due to better transportation network, will result a decrease in cost for a company working within industry, , external economies of scale have been achieved. Diseconomies of scale are the forces that cause larger firms to produce goods and services at increased per unit costs. The concept is the opposite of economies of scale to a situation which economies of scale no longer function for a firm. Rather than experiencing continued decreasing costs per increase in output, firms see an increase in marginal cost when output is increased (appendix 6). When a firm expands its production scale beyond a certain level, it suffers certain disadvantages. These disadvantages are called internal diseconomies of scale. The result of these diseconomies of scale is a fall run average cost. There are a number of factors that might give rise to inefficiencies as the size of the firm grows. As the size of the firm grows beyond a certain level, organization, control and planning is needed. This makes the managerial responsibilities more difficult. Delegation of the management functions to lower personnel becomes very common. Since the lower personnel lack the adequate experience to undertake the task, it may result in low output at higher cost. All these lead to an increase in the long-run average cost. Further, the external diseconomies of scale are beyond the control of a company increases its total costs, as output in the rest of the industry increases. The increase in costs can be associated with market prices increasing for some or all of the factors of production. For instance, high competition for labor, when there is more firms in industry, there will be increased demand for labor, making the best workers harder to keep (Keat and Young, 2009). References Stafffullcoll.edu. n.d. DETERMINANTS OF DEMAND. [online] Available at: http://staffwww.fullcoll.edu/fchan/macro/1determinants_of_demand.htm [Accessed: 28 Mar 2014]. Keat, P.G. and Young, P.K.Y., 2009 ‘Managerial Economics: 6th ed. Economic Tools for Today’s Decision Makers’. Pg. 266-268

Causes of The Great Depression Essay -- essays research papers

The Great Depression It is said that the cause of the catastrophic stock market crash known as the great depression was due mostly to uncontrolled political and industrial systems otherwise known as capitalism. However, the timeline leading up to the Great Depression proves that many other factors played a role in the stock market crash that occurred in the decade of the 1930's. So lets take a look at rather four, factors contributing to the great depression that we will further discuss in the following paragraphs. Four of the main causes that led up to the great depression were unequal distribution of wealth, uncontrolled political and industrial systems, high tariffs and war debts. Money was distributed mostly between the rich and the middle-class, in the United States, and between the U.S. and Europe. This imbalance of wealth created an unstable economy this type of the economy eventually lead up to large market crashes. These market crashes, caused the American economy to be overturned. The total income in the United States rose from $74.3 billion in 1923 to $89 billion in 1929 this rise in the economy was due to the Coolidge Prosperity(Business and Industry was flourishing and big business became bigger so the stock market went up greatly) even after this boost in the stock market the money wasn’t making its way around equally because most farmers were still poor. United States maintained high 1. tariffs on goods imported from other countries, at the same time that it was making foreign loans and trying to export products. This combination could not be sustained: If other nations could not sell their goods in the United States, they could not make enough money to buy American products or repay American loan... ... June 1939 7.2 10.4 + 7.9 17.2 1940 6.9 9.9 1941 7.7 12.1 1942 10.3 24.8 1943 13.7 44.8 1944 21.7 45.3 1945 21.3 43.7 As you can see, Roosevelt began to bring the people out of the depression and that resulted in some astonishing growth numbers. (Roosevelt's average growth of 5.2 percent during the Great Depression is even higher than Reagan's 3.7 percent growth during his Seven Fat Years ) When 1936 saw a phenomenal record of 14 percent growth, Roosevelt eased back on the deficit spending, overly worried about balancing the budget. Between 1940 and 1945, the Growth Deficit Product nearly doubled in size, from $832 billion to $1,559 billion in constant 87 dollars. And this occurred as deficit spending soared, to levels Keynes had earlier and unsuccessfully recommended to Roosevelt

A comparison between cardiac CT scanning and cardiac digital subtraction angiography (DSA)

Abstract Coronary artery disease affects nearly one tenth of the UK population and remains the leading cause of death in the western world. To investigate and provide interventions for coronary artery disease, imaging of the coronary arteries to enable visualisation of atheromatous plaque is required. This review looked at the techniques of cardiac computed tomography scanning and cardiac digital subtraction angiography, and their contribution to the investigation of coronary artery disease. Comparison of the procedures considered technique, radiation exposure, contrast agent, clinical indications and efficacy in diagnosis of coronary artery stenosis. On comparison of the effectiveness of the techniques, both were shown to have been effective non-invasive procedures that may be used to rule out diagnoses and avoid inappropriate use of invasive angiography. The research shows mixed evidence for cardiac computed tomography angiography as a test of high specificity, however sensitivity and speci ficity of cardiac digital subtraction angiography is high, and therefore suggest that the techniques may be useful in low risk patients. Introduction Coronary artery disease remains the main cause of death in the UK and western world (Hacker, 2013; Liu et al., 2002) and contributes a substantial disease burden, affecting 7% of men and 5% of women in the UK in 1999 (Liu et al., 2002). Coronary artery disease results from the build up of atherosclerotic plaque within the arteries supplying the myocardium. This plaque limits the flow of blood through the arteries, and can cause ischaemia of the heart muscle. If the plaque becomes unstable and ruptures, this may lead to thrombus formation and the complete occlusion of an artery, resulting in a myocardial infarction (McClure et al., 2009). Acute coronary syndrome (ACS) is a sub-classification of coronary artery disease and encompasses unstable angina, non-ST elevation myocardial infarction and ST elevation myocardial infarction. ACS represents a range of conditions that result from thrombus formation in coronary arteries, and if untreated has poor prognosis and high mortality (NICE, 2010). To investigate and provide information for interventions for coronary artery disease and ACS, visualization of the coronary arteries and any lesions caused by atherosclerotic plaque is required. Advances in technology have given rise to several sophisticated perfusion analysis techniques, which provide greater prognostic value than morphological imaging (Hacker, 2013). Perfusion analysis allows the blood flow through the coronary vessels to be observed and any abnormalities in the perfusion can be interpreted as a functional consequence of atherosclerotic changes within the vessels (Hacker, 2013). Currently, UK guidelines (NICE, 2010a) recommend coronary angiogram as first line management for patients presenting with ACS. This enables imaging of the coronary arteries to assess perfusion. It is important to assess the circulation as arteries can be affected from the earliest stages of endothelial dysfunction to high-grade coronary artery stenoses (Hacker et al., 2010; Bugiardini et al. 2004; Kaufmann et al., 2000), and this provides the information necessary for prognosis and intervention. With the advances in technology, there are now various diagnostic tests available to assess coronary artery disease, including coronary angiography and computed tomography (CT) scanning (Gorenoi, Schonermark & Hagen, 2012). This review aims to review the literature on coronary CT scanning and digital subtraction angiography, their clinical applications, techniques and comparative value in coronary artery assessment and diagnosis. Cardiac Digital subtraction angiography Coronary angiography is the conventional diagnostic procedure used in coronary artery disease. It is a minimally invasive technique, whereby a catheter is placed into the radial or femoral artery and is advanced through the arterial system to the coronary arteries. A contrast agent is then injected at the aortic root and allows visualization of the arteries using x-ray in real time at up to 30 frames per second. This allows a view of the extent, location and severity of coronary obstructive lesions such as atherosclerosis and enables prognostic indication (Miller et al., 2008). Coronary angiography also enables catheter placement either side of the lesion to assess pressure changes and determines the degree of flow obstruction (Miller et al., 2008). . Digital subtraction angiography (DSA) again works by introducing a contrast agent into the coronary arteries and taking x-rays in real time, however a pre image is taken by x-ray. This allows for the post images to be subtracted from the original mask image, eliminating bone and soft tissue images, which would otherwise overlie the artery under study (Hasegawa, 1987). Unlike conventional angiography, it is possible to conduct DSA via the venous system, through accessing the superior vena cava via the basillic vein (Myerowitz, 1982). This removes the risks associated with arterial cannulation (Mancini & Higgins, 1985). The procedure can also be performed with a lower dose of contrast agent and be done more quickly therefore eliminating constraints of using too much contrast during a procedure (Myerowitz, 1982). Whilst DSA is the gold standard in arterial imaging of carotid artery stenosis (Herzig et al., 2004), the application of DSA to the coronary arteries is limited due to motion artefacts associated with each heartbeat and respiration (Yamamoto et al., 2009). There are numerous cardiac clinical applications of DSA, it can be used to assess coronary blood flow (Molloi et al., 1996), valvular regurgitation (Booth, Nissen & DeMaria, 1985), cardiac phase (Katritsis et al., 1988), congenital heart shunts (Myerowitz, Swanson, & Turnipseed, 1985), coronary bypass grafts and percutaneous coronary intervention outcomes (Katritsis et al, 1988; Guthaner, Wexler & Bradley, 1985). However, others have suggested that the coronary arteries are not visualized well due to their small size, movement, their position overlying the opacified aorta and left ventricle, and confusion with other structures such as the pulmonary veins (Myerowitz, 1982). Cardiac CT Scanning Development of CT scanning in the 1990s enabled an increase in temporal resolution that was sufficient to view the beating heart, and they now provide a non-invasive technique for diagnostic and prognostic purposes. Cardiac CT scans have clinical applications that go beyond perfusion investigation, and can be used to assess structure and function of the heart (for example in electrophysiology disorders or congenital heart disease) due to its ability to provide anatomical detail (Achenbach & Raggi, 2010). CT scans can be used to assess coronary artery disease with and without injection of contrast agent (Achenbach & Raggi, 2010) by calcium scan or CT angiography. Coronary calcium CT scanning uses the evidence base that coronary artery calcium is a correlate of atherosclerosis (Burke et al., 2003) and is a strong prognostic predictor of the future development of coronary artery disease and cardiac events (Arad et al., 2000; Budoff et al., 2009; Achenbach & Raggi, 2010). Calcium is easily depicted on CT scan due to its high CT attenuation, and is classified according to the Agatson score, which considers the density and area of the calcification (Hoffman, Brady & Muller, 2003). Coronary CT angiography (CTA) allows visualization of the coronary artery lumen to identify any atherosclerosis or stenosis within the vessels. Patients are injected intravenously with a contrast agent and then undergo a CT scan. There are limitations regarding the suitability of patients for coronary CTA due to prerequisites of sinus rhythm, low heart rate and ability to follow breath-holding commands. Additionally, obesity presents a problem for patients that cannot fit into the scanner and affects the accuracy of the procedure. (Achenbach & Raggi, 2010). Comparison of cardiac DSA and cardiac CT scanning The technical differences between cardiac DSA and cardiac CT scanning give rise to differences in the clinical indications for the procedures, their diagnostic efficacy and also different risks or relative benefits to the patients. Due to the nature of the images produced by coronary CTA and DSA, each lends itself to different indications for use. Whilst coronary DSA provides imaging of all aspects of perfusion, CTA used with contrast agent also provides this however has the additional advantage of being able to assess structure and function of the heart. Coronary CTA has been shown to have a high accuracy at detection and exclusion of coronary artery stenoses (Achenbach & Raggi, 2010). In a multicentre trial conducted by Miller et al. (2008), patients underwent coronary calcium scoring and CT angiography prior to conventional invasive coronary angiography. The diagnostic accuracy of coronary CTA at ruling out or detecting coronary stenoses of 50% was shown to have a sensitivity of 85% and a specificity of 90%. This showed that coronary CTA was particularly effective at ruling out non-significant stenoses. Additionally, coronary CTA was shown to be of equal efficacy as conventional coronary angiography at identifying the patients that subsequently went on to have revascularisation via percutaneous intervention. This was shown by an area under the curve (AUC), a measure of accuracy of 0.84 for coronary CTA and 0.82 for coronary angiography. Miller et al.’s (2008) study included a large number of patients at different study sites , and additionally represented a large variety of clinical patient characteristics. The author’s claim that these factors contribute to the strength and validity of the study findings, and suggest that in addition to using patients with clinical indications for anatomical coronary imaging, should be used as evidence that coronary CTA is accurate at identifying disease severity in coronary artery disease. Miller et al. (2008) did however,, find that positive predictive and negative predictive values of coronary CTA were 91% and 83% respectively and therefore suggested that coronary CTA should not be used in place of the more accurate conventional coronary angiography. A low positive predictive value (in relation to the prevalence of disease) was proposed to be due to a tendency to overestimate stenosis degree as well as the presence of artefacts leading to false positive interpretation (Achenbach & Raggi, 2010). Other research providing comparison between coronary CTA and conventional coronary angiogram has highlighted variability in results. A meta-analysis conducted by Gorenoi, Schonermark and Hagen (2012) investigated the diagnostic capabilities of coronary CTA and invasive coronary angiography using intracoronary pressure measurement as the reference standard. The authors found that CT coronary angiography had a greater sensitivity than invasive coronary angiography (80% vs 67%), meaning that coronary CTA was more likely to identify functionally relevant coronary artery stenoses in patients. Despite this,, specificity of coronary CTA was 67%, compared to 75% in invasive coronary angiography, meaning that the technique was less effective at correctly excluding non-diagnoses than invasive coronary angiogram. This research appears to contradict the power of cardiac CTA at excluding diagnoses of coronary artery stenosis as suggested by Miller et al. (2008), he study did combine evidence from over 44 studies to provide their results and therefore had a large statistical power. The authors interpret the results in light of the clinical relevance of cardiac imaging, suggesting that patients with a higher pretest possibility of coronary heart disease will likely require invasive coronary angiography for revascularisation indicating that coronary CTA may be a helpful technique in those patients with an intermediate pre-test probability of coronary heart disease that will therefore not require invasive angiography. Goldberg et al. (1986) investigated the efficacy of DSA in comparison to conventional coronary angiography in 77 patients. They found that the two angiograms agreed within one grade of severity in 84% of single cases and 90% of multiple cases, identifying both patent and lesioned arteries. The results led the authors to conclude that there was no significant difference between the two methods and that DSA could be used in selective coronary angiography to find results comparable to that of conventional angiography. In addition to being a small study into the efficacy of DSA, the study also had several sources of inherent variability that should be considered when interpreting the results. These included differing sizes of digital imaging screen and non-use of calipers, meaning that the interpretation of the images could vary throughout the study. The authors also suggest that whilst showing strong support for the use of DSA in coronary artery disease, the technique may not actually p ermit better prognostic determinations or clinical judgements that are better than conventional angiography, and therefore the further implementation of the techniques may not be founded or necessitated. More recently, there has been further research looking at the effectiveness of DSA as a way of measuring coronary blood flow. Whilst motion artefacts have proven a problem in lots of past research (Marinus, Buis & Benthem, 1990; Hangiandreou, 1990), recent research has developed methods to minimise these. Moilloi and colleaues (1996) showed that using a motion-immune dual-energy digital subtraction angiography, absolute volumetric coronary blood flow could be measured accurately and thus provide an indication of the severity of any arterial stenosis.This may provide further suggestion for clinical implementation of DSA. Although these studies provide evidence for the efficacy of cardiac DSA and CTA, they often make comparisons to conventional angiography. This is useful as a baseline comparison, however it is difficult to make comparisons between the two procedures directly due to less available evidence making direct comparisons. Lupon-Roses et al. (1985) conducted a study investigating both coronary CTA and venous DSA. The study looked at the efficacy of both techniques at diagnosing patency of coronary artery grafts compared to the control conventional angiography. CT was shown to diagnose 93% of the patent grafts and 67% of the occluded grafts whereas DSA correctly diagnosed 98% and 100% of patent and occluded grafts respectively. Interestingly, the DSA picked up the 11 grafts that were misdiagnosed by CTA and the CTA picked up the 2 grafts misdiagnosed by the DSA. This data may suggest that individually, DSA has a better profile for diagnosis of coronary artery occlusion, however if the two procedures are used in combination exclusion of patent arteries and diagnosis of occluded arteries would be effective (Lupon-Roses et al., 1985). Coronary DSA and CTA are both non-invasive procedures (unlike the conventional coronary angiography where a wire is placed in the coronary vasculature). With the only invasive part of the procedure being the injection of the contrast material into a vein. This presents a significant advantage to both procedures over that of conventional angiography, and may even permit investigation on an outpatient basis (Meaney et al., 1980). Similarly, both DSA and coronary CTA are favoured because of their intravenous approach, eliminating the risks of bleeding or arterial injury from an intra-arterial catheterization and being able to be used in those with limited arterial access. However, although the intravenous approach used in cardiac DSA makes it favourable, it does lead to difficulty with visualisation of the coronary arteries due to the overlying iodinated pulmonary and cardiac structures (Mancini & Higgins, 1985). Therefore,, intra-arterial DSA is also sometimes used (Yamamoto et al., 20 09). As with all CT scanning, coronary CTA carries with it a dose of ionizing radiation (Brenner & Hall, 2007). Studies have estimated that for diagnostic CT scanning, patients are on average exposed to 12mSv of radiation during the procedure, the equivalent of 600 x-rays (Hausleiter et al., 2009). Estimates of radiation doses associated with conventional coronary angiography are lower than that of coronary CTA at 7mSv (Einstein et al., 2007). Additionally, DSA technique reduces the radiation dose from that of conventional coronary angiography as the vessels are visualised more clearly (Yamamoto et al., 2008). The dangers of radiation exposure are increased risk of developing cancer, skin injuries and cateracts (Einstein et al., 2007). It is therefore important that the benefits of conducting the procedure greatly outweigh the risk of radiation exposure. CT calcium scanning provides a low radiation dose at around 1mSv (Hunold et al., 2003). Cardiac CT calcium scanning does not require administration of a contrast agent, unlike in coronary CTA and DSA that use iodine based contrast agents. The risks associated with contrast agent include nephrotoxicity and risks of hives, allergic reactions and anaphylaxis (Maddox, 2002). The amount of contrast agent used is partly dependent on the length of the procedure and how clearly the arteries can be visualised. For this reason, both cardiac CTA and DSA use less contrast agent that conventional coronary angiography (Brant-Zawadzki, et al., 1983). CT calcium scanning of the coronary arteries is therefore recommended in those with less likelihood of coronary artery disease (NICE, 2010). Both coronary CTA and DSA require interpretation by trained physicians, and the importance of training and achieving intra-rater reliability should not be underestimated (Pugliese et al., 2009). Conclusion Overall, both coronary CT and DSA have been demonstrated as effective procedures for the imaging of the coronary arteries in CAD (Achenbach & Raggi, 2010; Miller et al., 2008; Moilloi et al., 1996; Goldberg et al., 1986). Whilst cardiac CT scanning does provide a wider range of clinical applications, allowing assessment of perfusion as well as cardiac structure and function (Achenbach & Raggi, 2010), coronary DSA has many applications that allow assessment of coronary blood flow (Molloi et al., 1996; Katritsis et al, 1988; Booth, Nissen & DeMaria, 1985; Guthaner, Wexler & Bradley, 1985; Myerowitz, Swanson, & Turnipseed, 198). Both cardiac DSA and CTA procedures have their advantages. As non-invasive procedures, these techniques pose less risk to patients, and enable the possibility of outpatient investigation, to be used to rule out diagnoses and to avoid inappropriate invasive coronary angiogram (Gorenori et al., 2012). Additionally, intravenous access is preferential to arterial cannulation for the contrast infusion, removing the risks associated with bleeding or intra-arterial injury. Cardiac DSA exposes the patient to a lower dose of radiation that coronary CTA (Hausleiter et al., 2009; Yamamoto et al., 2008; Einstein et al., 2007), which is beneficial at reducing the risk of genetic mutations and cancer. Cardiac CTA and DSA also have their common disadvantages. The use of contrast agent may present side effects for the patient including kidney damage and risk of allergic reactions and anaphylaxis (Maddox, 2002). For this reason, calcium CT scanning can be useful in patients that are not at high likelihood of coronary artery disease (NICE, 2010b). Additionally, both cardiac DSA and CTA are subject to motion artefacts from respiration and heart beats, which can cause difficulties with interpretation (Achenbach & Raggi, 2010; Yamamoto et al., 2009). In the case of cardiac CTA, this excludes a subset of patients that are unable to follow commands and those who have high heart rates. Overall, cardiac CTA and cardiac DSA are effective, non-invasive imaging techniques for assessment of coronary artery disease. Whilst they are not the gold standards in cardiac monitoring, they can provide important diagnostic information without exposing patients to the risks of invasive angiography. Due to this, their use should be weighted against clinical need, the risks of the procedures, and the suitability of the patient. Interpretation of cardiac CTA and DSA imaging should be by trained individuals. 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