Saturday, October 5, 2019

Law and mangement Essay Example | Topics and Well Written Essays - 3000 words

Law and mangement - Essay Example e individual/ parties to an agreement identify the formation and termination terms of contract incorporating in as well as the privileges plus tasks of the participating groups under that contract (David, 2009). The acceptance of a contract of a suggestion takes place while there is an untrained recognition of the entire accessible terms. Despite the fact that, this is extraordinary as well as there will usually be a time of collaboration. New terms as well as conditions presented in the course of cooperation in consequence quantity to a succession of responses to present the unique offer, cancelling the conditions and terms of the unusual offer (Contract). If an agreement is prepared, and for any cause it afterward turns out to be unworkable to for one party to act upon their obligations, then we need to think about frustration. Be cautious to note that frustration is about following impossibility; if an agreement was impossible to carry out right from the beginning, then the matter is one of error and not frustration (Smithies, 2007). Frustration of contract is a fake declaration of contracting details prepared through one participating contract party to another participating party as well as has the outcome of suggest that contacting group party into the agreement. For instance, beneath definite state of affairs, frustration of contract makes a statements or promise prepared through a retailer of goods concerning the excellence or feature of the manufactured goods that the vendor has may encompass the developed standards or misrepresentation. A conclusion of falsification permits for a conduct of rescission as well as irregularly gu arantee depending on the kind of distortion (Smithies, 2007). In this situation Harry offer his Motor Cycle for sale to Ian at $ 500. The main mistake done here is the establishment of any detailed document for regarding the offer. Here no time limit is defined no prices is established. In this situation Harry is free to sale his

Friday, October 4, 2019

In what ways has transatlantic slavery impacted on British society Essay

In what ways has transatlantic slavery impacted on British society (SOCIOLOGY) - Essay Example The early 17th century witnessed the dawn for the British to be considerably one of the most successful slavers in the Atlantic region. During these years, the kingdom emerged a key player in a commercial undertaking which â€Å"linked the economies of three continents, often called as the Triangular Trade† (UNESCO, 2010). Until the time arrived when the British could no longer stand the horrendous practice of slavery and decided then for its abolition. Economic Motives The main players in the triangular trade, England, Spain, Portugal, France, the Netherlands and the United States, among others, were not able to resist the commercial attractiveness of slavery and were drawn to do their best to benefit from it. Mainly driven by economic and political reasons, these fierce maritime and colonial powers ventured in the abduction and selling of African peoples, to enslave in their homes and plantations (Walvin, 2007). Sir John Hawkins, under the blessing of Queen Elizabeth 1, foll owed in the footprints of the Portuguese in navigating the western coastlines of Africa and enslaving people in the 1560s (Rodriguez, 1997). The Britons thought it was risky business, but they could not refuse the immense economic gains that awaited them. By fair and foul means, Britain outplayed its European rivals and became the premier slave trader until 1807. Major trading ports that dealt with this business were established in Bristol, Liverpool, Glasgow and London. Some other smaller British ports also followed suit. The number of vessels for slave trading were built in the nation’s several shipyards and sailed through the ‘Slave Coast’ carrying goods such as guns and other ammunition, textile and metals in exchange for human beings. For certain, the trade was an extremely lucrative business. The immense degree of consumption and productivity of the people is said to be its point of departure (Inikori & Engerman, 1992). Rise of Industrial Revolution As the ports in Bristol and Liverpool became prosperous and generated more jobs, so are the residents of both cities who invested their financial resources into developing several industries. This gargantuan industrial progress began in 1750 and continued for many decades. Some who obtained adequate sums of money sourced from the production of tobacco, sugar and cotton poured in their capital into warehouses, quaysides, factories, trading houses and banking institutions. Factories sprouted in the metropolis, particularly in textile and mills. Coal mines burgeoned in the rural areas, as well (Packer, 2007). Thus, the positive economic reverberations of the time were felt everywhere. This is in harmony with John Maynard Keynes economic theory which upholds the view that the â€Å"balance between supply and demand would ensure full employment† (Keynes, 2006: xvii). â€Å"The systemic operations instituted in slave trading, accordingly, were adapted and applied during this period† (Rice & Poulter, 2007). Thus, it is safe to infer that the workings in plantation slavery were the engines which drove the creation of the Industrial Revolution in Britain that influenced other countries of the Western hemisphere and the whole world to move along. The Modernisation Theory and the Theory of Social Development which uphold that progress and evolution of societies are irrepressible bear truth on this fact. Sugar and the British Cuisine The African

Thursday, October 3, 2019

Purchasing Power Parity; Does It Exist Essay Example for Free

Purchasing Power Parity; Does It Exist Essay Introduction   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The Purchasing Power Parity doctrine is perhaps one of the most controversial financial theories. Over the years, it has had its ebbs and flows, with proponents expositing several mathematical and statistical formula to strengthen the theory, while critics have severally condemned the utility of the theory; however, according to Belassa1 the doctrine has managed to survive nevertheless. Belassa argues that, though in somewhat ambiguous terms, the doctrine has been invoked as early as during the Napoleonic wars, the christening and explanation of the doctrine came from Prof. Gustav Cassel during the First World War and was popularized after the Second World War. The author further posits that interests in the theory tend to be invoked when existing exchanges rates were thought to be unrealistic and there was, therefore, a search for what is considered equilibrium rates2.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Perhaps one of the controversies that have built up around the Purchasing Power Parity starts with the issue of definition. Different authors tend to come up with their own definition (version) of the theory, and as a result, the theory has come to mean different things to different authors3. Before looking at some of the conceptualizations of the theory that has generated over time, it is pertinent, to first examine the theory as was professed by its author Prof. Gustav Cassel.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Bunting4   presents the first exposition of the theory in Cassels’s Money and Foreign Exchange after 1914, which he said was one of the earliest and best explanation of the theory by the author.   Bunting explains that the concept of purchasing power parity was borne out of the need to establish what determined exchange rates in Europe after the era of gold standard was gone, that is, when national currencies were on inconvertible basis. On this basis, Cassel explains that considering the fact that the primary reason a country’s currency is in demand in a foreign country is the need to purchase goods produced in that country. Thus, when normal, unrestricted trade between [two] countries have been established over time, the exchange rates become fixed relative to the purchasing power of each currency domestically, and as long as this domestic purchasing power of the currencies do not change, nothing will happen to the exch ange rates5. Further, the theory states that when the currencies of these countries undergo inflation, the â€Å"the normal rate of exchange will be equal to the old rate multiplied by the quotient of the degree of inflation in the one country and in the other†6. While this explanation describes the basic skeleton of the theory, there have been several adjustments and modifications of the meanings and concept of the theory as several authors tend to strengthen or criticize it. Some of these adjustments to the meaning of the theory will suffice to buttress this point.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Everett and his colleagues7   attempting to measure currency strengths and weakness with the purchasing power parity concept, posited that as long as there is unrestricted trades, exchange rates of currencies tend to obey the purchasing power of the currencies. In this regard, they succinctly conceive the theory to mean thus regardless of how currencies are denominated, when adjusted for units; all currencies tend to command the same basket of goods8. This definition is similar to that adopted by Klein et al.9, who likened the purchasing power parity doctrine to the law of One Price with the explanation that an identical good (or service) would command the same price, measured in a given numeraire system, all over the trading world10.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Belassa, however, gave a more elaborate explanation of the purchasing power doctrine, differentiating between the relative and absolute interpretations of the theory. According to him, the absolute version of purchasing power parity theory argues that when purchasing power parities are calculated as a ratio of consumer goods prices for any pair of countries, the result reflects the equilibrium rates of exchange. On the other hand, the relative version of the theory asserts that, when compared to a period when equilibrium rates prevailed, changes in the relative prices of goods would indicate the necessary adjustments in exchange rates11. In a sense, one can infer from these definitions that the absolute version of the theory seeks to establish ‘equilibrium’ exchanges rates between any pair of countries based on purchasing power of their currencies, while the relative version intends to measure the over and undervaluation of currencies at any period in time12.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Despite the controversies surrounding the validity and utility of this theory, recently, authors have sought to clothe the doctrine in â€Å"the garments of respectability† and in this regard, several statistical materials have been presented that more accurately reflects the relationship between power of currencies and exchange rates, as conceived in the theory 13. The purpose of this paper is, therefore, to examine some of the literatures regarding the theory and perhaps to infer from these, the implications and future research possibilities of the theory. Literature Review   Balassa, Bela (1964). The Purchasing-Power Parity Doctrine: A Reappraisal.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Belassa14 apparently belongs to the group of authors that intend to strengthen the validity and utility of the purchasing power parity doctrine. He begins by first differentiating between absolute and relative versions of the theory, as explained above. He, however, asserted that the doctrine as postulated by Cassel tends towards the absolute version when he states that the rate of exchange between two countries will be determined by the quotient between the general levels of prices in the two countries15. Further, he explains that theory as invoked by another author indicates that the German mark was undervalued against the dollar, while the mark too was overvalued, and the Austrian shilling, Danish crown and Dutch guilder all undervalued, by extending the theory to the currencies of less developed countries, their currencies appears to be undervalued against the dollar. The author contends that the deviation from the calculated exchanges were too much to be caused by errors.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the bid to correct the perceived weakness in the theory, Belassa created a new model for the theory by introducing non-traded goods (services) into the traditional two-country, two-commodity model of the theory. This model of the theory is strengthened by the following assumptions; that there is only one limiting factor – labor, and constant input coefficient. Also, under the assumption of constant marginal rates of transformation, countries with relative higher productivity levels will experience higher relative price of non-traded commodity compared to another. From these propositions, the author posit that income levels play a significant level in the calculation of purchase powers and that purchasing power parities will be more closely related to exchange rates when prices are expressed in terms of wage units.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   From this equation, the author posit that if we were to assume production of traded goods relative to non-traded goods constitutes the major difference in international productivity, currencies of country with higher productivity will appear to be overvalued using purchasing power parity calculations. However, if per capita income was to be used as a representative of levels of productivity, the ratio of purchasing power parity to exchange rate will be an increasing reflection of income levels   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In providing empirical confirmation the proposed relationship between purchasing power parity, exchange rates and income levels, the author argues thus: â€Å"if differences in tastes do not counterbalance differences in productive endowments, there will be a tendency in each country to consume commodities with lower relative prices in larger quantities†16 . The result is that the purchasing power of country II’s currency will be undervalued if country I’s consumption pattern is used as weights and overestimated if country II’s consumption is used. This is shown in the tables below.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The second table above shows the comparison of the cost of household services in the United States and Italy for 1950. The author argue that after conversion at exchange rates, domestic services in Italy seem to cost about one-fifth of their United states’ price, barber and beauty shops cost one-fourth, laundry and dry cleaning the same cost. In the same vein, purchasing power equivalents for household services was 391 lira at US weights and 165lira at Italian weights. These figures confirm, the author argues, that services (non-traded goods) cost more, relatively, in countries with higher income levels. Thus, it buttresses the relationship between purchasing power parity, exchange rates and income levels. Bunting, H.   Frederick (1939). The Purchasing Power Parity Theory Reexamined.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Bunting18, while conceding that the purchase power parity doctrine has been severally criticized, further adds his criticism by, according to him, submitting the theory to an improved statistical test. The basis of the argument set forth in this paper is that though the author of the doctrine of purchasing power parity discussed some likely exceptions to the theory, which could account for the differences observed between actual exchanges rates and parity calculated rates, several other exceptions that render the theory impracticable exists.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The author proffered an elaborate definition (explanation) of the theory, as conceived by Cassel and the proposed relationship between purchasing power of currencies and their exchange rates. Further, he went on to summarize the major exceptions to the general rule into seven main points, as discussed by Cassel in his book; Money and Foreign Exchange After 1914. Accordingly, he explained that exchange rates are expected to deviate from the calculated rates if, domestic prices fluctuate in relation to one another, due to any series of factors; tariffs and/or shipping costs change in relation to those prevalent in the base year used for the calculation; obstructions to trade other tariffs and shipping costs becomes operational during the year under consideration; sudden devaluation of currency occurs during the transition period; the activities of speculators affect exchange rates; governments are in need of foreign exchange, for example to pay international debts; and the base year or general price index is not properly selected, as defects in the price index used or the base year could cause predictive error in calculated rates. In sum, Bunting posits that though these exceptions are many and powerful, they do not fully subsume factors/reasons responsible for differences in actual rates and calculated rates.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In this regard, the author asserts that the critique of the theory can be simplified by considering problems of price levels and direction of change. On the issue of price level, he argues that, problems with choice of base year and the commodities that should make up the price indices to be used in the calculation shows ambiguity in the theory. First, with base year determination, the author argues that Cassel’s contention that it is only if we know the exchange rate which represents a certain equilibrium that we can calculate the rate which represents the same equilibrium at an altered value of the monetary units of the two countries19 i.e. we can only calculate the equilibrium rate now if we know the rate at a particular ‘base’ year; is faulty because there is no such thing in international trades. He argues that the fact that international economic conditions do not persist for long means that a given base year can only be reasonably used to measure relative price changes for only a short period of time.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   On the commodity prices to be included in the price index, Bunting also faults Cassel’s insistence that ‘general’ price index should be used, arguing that not all goods are traded internationally. Thus changes in commodities not traded internationally can, therefore, have no effect on foreign country’s evaluation of a country’s currency. Further, on the direction of change, the author argues that Cassel’s contention that â€Å"when currencies are not on a convertible specie standard it is parities which determine exchange rates†20   tend to overlook the possibility that the direction of change could be the reverse i.e. price levels may be caused by changes in exchange rates. Thus, while Cassel concedes that the actions of speculators could cause changes in exchange rates without necessary price changes; there are several other factors that are capable of inducing change in exchange rates. Bunting mentions the following factors; Government monetary policies – alterations of central bank rates, stabilization funds, international government loans; Private international loans and special considerations such as large corporations transferring their capital holdings from one country to the other to protect their profits, or tourist expenditures and immigration remittances, which both involve the purchase of foreign currencies with no regard for the purchasing power of the currencies involved.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Subjecting the purchasing power parity theory to statistical tests, the author presents his result in the graphical form shown below. In the charts below, Franco-American exchange rates were compared for 1920s and 1930s. The solid line represents calculated rates while the broken line labeled no lag represents actual rates. The differences exhibited between the actual and calculated rates for the statistical test constitute discrepancy in the theory. The 1month, 2months and 3months lag periods were allowed in the assumption that time should be allowed for changes in purchasing power parities to effect a change in exchange rate, thus the 1-3months lag should show more correlation with the actual rates, however, this was not the case. The author concludes that proponents of the theory should simply recognize the fact that the theory as it stand is defective and needs to be refined. The authors of this paper proffered answers to criticisms of the validity and utility of the purchasing power parity theory, and especially to the claims that though the theory worked relatively in the 1920s, it failed in the 1970s by some other authors. Davutyan and John21 contend that possible reasons for the apparent failure of the purchasing power theory to predict exchange rates accurately when figures from the 1970s are used could include the fact that relatively to 1920; monetary policies were more coordinated in the 1970s. They therefore, assert that it is the coordination of monetary policies, not the failure of the purchasing power parity theory that causes conventional statistical tests to reject the validity of purchasing power parity for the 1970s. Providing evidence to support their claims, the authors posit that if we are to assume that there are no obstructions to trade, i.e. all goods are tradable and effective arbitrage refers to the relative version of the purchasing power theory, as explained by Bellassa22 above. In consolidating their argument, the authors contend that purchasing power parity tend to fail under two instances: when arbitragers fail to respond to profitable opportunities or when transaction costs and other impediments inhibit trades. However, they contend that the first factor might not be feasible, so the latter appears to be more important. Elucidating on the second factor, Davutyan and John   posit that under the assumption of zero transaction costs all goods are tradable, when this assumption is listed, goods could be divided into two categories, tradables with zero transaction costs and non-tradables with high transaction costs. Thus, in the absence of transaction costs, arbitrage keeps relative prices of tradable goods across countries equal, but this is not the case between non-tradables as well as between tradables and non-tradables. Therefore, when there are economic shocks, the equation above holds tradables but not for non-tradables. Furthermore, the authors contend that even with tradables, while the zero transaction costs is convenient in theory, it is not always so in reality. The fact is that relative transaction cost differs between countries and this too, tends to introduce errors into the purchasing power parity calculation, as with the non-tradables.   Another source of error in purchasing power calculation, according to the authors, is unequal weights used for calculation. They argue that in the second equation above, the weights in the price index are the same for both countries; however, using CPI or wholesale price index or GNP deflators would violate the requirement for similar weights and could introduce error into the measurement. To support their claims, the authors present the data in the table below, where R2 and estimate of the regression coefficient supports the argument that purchasing power parity works.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Everett24 and his colleagues presented a practical and working model of the purchasing power parity theory and argued that by using this model of the theory to calculate exchange rates, currency strengths and weakness can be measured. Defining purchasing power parity, the authors contend that the primary concept of the theory is that when the forces of price mechanism are unrestricted, exchange rates tend to conform to the purchasing power of currencies. Thus, instead of price levels adjusting to exchange rates, the reverse is the case. In this regard, the authors assert that while this general idea of the theory applies to a world of floating exchange rates, their model of the purchasing power theory can be adapted to a variety of exchange rate regimes, such as managed floats, crawling pegs and fixed exchange rates.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In explaining this model of the purchasing power parity, the authors refer to what they called the parity chart. As shown below, the chart is derived thus: the horizontal axis measures time from a chosen time of origin – the base year; while the vertical axis measures two things, one, the difference in the percentage of the purchasing power of currencies and two, the percentage change in the actual exchange rate from the base year. While the dotted line represents the actual/observed exchange rates, the parity (solid) line represents parity (calculated) exchange rates over time.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Using the two country model to explain the ‘parity chart’, the authors explain that if we assume that there are no restrictions to trade, and the perfect base time, under this scenario, if the change in the purchasing power of country A’s currency differs from that of country B, the parity line in the chart above will have a positive or negative slope, depending on the sign of the difference between the purchasing power of the currencies under consideration. Further, if actual exchange rates were to be plotted on the same chart, the slope should conform closely to that of the parity line. What can be inferred from this explanation is that the parity line in the chart closely reflects the expected change in exchange rates that should follow changes in the purchasing power of country currencies.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   To support their claims that the parity chart can be used to measure changes in exchange rates under any type of exchange rate regime, the authors presented empirical results of several currencies with different exchange rate regimes, these included the German mark-a more or less freely floating exchange rate; Spanish peseta-a strictly managed exchange rate; Colombian peso-a crawling peg currency; and South African rand-a fixed exchange rate25. The result for the German mark is presented below:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The authors explain that the vertical axis measures the percentage deviation from the calculated rate. While the line representing the inflation factor shows a fairly steady rise, in line with the well known fact of relatively lower rates of increases in the West German price level compared with most other countries, the line representing the exchange rate, on the other hand, shows no apparent trend, reflecting the fact that the exchange rates of West Germanys trading partners vis-à  -vis the dollar on a trade-weighted basis may have moved in opposite directions. These two factors when compounded, yields the parity line.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   After presenting empirical results for all the four representative countries listed above, the authors concluded that an indepth examination of the parity chart and line indicates that the parity line provides an effective and informed judgment about future currency movements. Further, that if â€Å"the parity rate diverges from the actual rate, this indicates that the currency is presently either over- or undervalued, and will therefore have to adjust, the longer the persistence of such a divergence, the more likely that an adjustment will occur soon†26.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   This is another study that attempted to strengthen the validity and utility of the purchasing power parity doctrine. These authors, in this study, posited that purchasing power parity could be used to derive a more effective simulation or projection of world economy. Admitting that the theory has come to mean different thing to different writers, the authors adopted the law of ‘one price’ definition of the theory, which explains that an â€Å"identical good or service would command the same price, measured in a given numeraire system, all over the trading world†27.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The authors further state that though there are several controversial issues about the theory, such as what category of goods should be included in the calculation or what time should be used as origin/base in the calculation, they assert that any detailed exchange rate modeling system should obey the purchasing power parity rule, in the long run. Statistically estimating the movement of exchange rates in relation to the purchasing power parity principle for the 1970s, the authors presented the following formula:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   According to the authors, this formula states that the â€Å"U.S. dollar terms, should have a common rate of change across all countries, namely, the U.S. rate of change of export prices†28. Thus, if the exchange rates during this time, had moved in accordance with the principle of purchasing power parity, then the estimates of: would be consistent with the hypothesis of purchasing power parity. Where a =O; b = -1.0; c = +1.0; eit =additive random error. Scatter diagrams of the data points of the two equations above are shown below. Conclusively, the authors assert that judging by these statistics, all the regression estimates in the charts above passed significance tests. Thus, it could be deduced that the relationship between purchasing power of currencies and the actual exchange rates was tightest for members of the EMS, but slightly less tight when the UK is included. Based on this evidence, the authors believe that their contention that, on average, purchasing power parity movements approximately reflects actual exchange rates in the 1970s has been adequately justified, and as a result, it could be generalized that calculations of purchasing power parity could be used in predicting movements of exchange rates.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   John29 proffered answers to criticisms concerning the predictive errors observed with exchange rates calculated from purchasing power parity. They observed that studies carried out by several authors indicate that for several countries, the predictive error of purchasing power parity during the 1970s followed what they referred to as ‘random walk’ i.e. whatever the deviation between the parity rate and actual rates observed this month, next month it is likely to increase as decrease.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In this regard, the author argued that the basic idea behind the purchasing power parity doctrine is that in the long run, the differences between the parity rates and the actual exchange rates tend to disappear and the tow rates are equated. They argue that, though economic shocks, in whatever guise, could, in the short term, drive the actual rate from the parity rates, but in the absence of new shocks, the price mechanism tend to equate the tow rates, in the long run. Based on this argument, the author contend that predictive errors for purchasing power parity should not perform a random walk, instead there should be a gradual decline or increase towards the actual rate.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Supporting their claims that predictive errors in purchasing power parity does not perform random walk in the long run; the authors presented the results of empirical studies of several countries using data for over seventy years.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Following the same path with paper reviewed above, Yeager30 also sought to strengthen the validity and utility of the purchasing power parity theory. He started off his argument with the basic assumption that people primarily value currencies for what could be bought with it, based on this assumption, he argues, it is safe to presume that in an unrestricted market, people will tend to exchange such currencies for their relative purchasing powers. The author admits that the theory, in its basic form, as stated above, is loose and ambiguous, he posits, however, that the theory performs tow main functions. First, the theory gives an expression of what the equilibrium exchange rates should be for currencies, however crude this rate appears. And two, the theory act like a stabilizing force for exchange rates. Explaining this second function, he assert that when for any reason, actual exchange rates deviate from the equilibrium rates, the theory describes pressures at work tending to check and reverse this random departures from the range of equilibrium rates.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The author provides this example to buttress the point made above about the stabilizing powers of the parity theory:   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Let us suppose, for example, that prevailing exchange rates unmistakably   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   undervalue the British pound in relation to the purchasing powers of the pound   Ã‚  Ã‚   and of foreign currencies.   Foreigners -say Americans- will offer dollars for   Ã‚  Ã‚  Ã‚  Ã‚   pounds to buy British goods at bargain prices. Britons will offer relatively few pounds for dollars to buy, American goods at their apparently high prices.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Unmatched attempts to sell dollars and buy pounds will bid the exchange rate toward the equilibrium level.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the same light, the author evaluates some of the numerous objections raised about the theory and posits that in most of these objections, the stabilizing pressures aspect of the theory has been mostly ignored. In sum, the author concludes that most of the discrepancies observed in purchasing power parity rates are due to â€Å"inappropriate base periods; disequilibrium exchange rates (including base-period rates), often imposed by official pegging; tariffs, quotas, and other interferences with trade, payments, and exchange rates.31†   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Wyman32   extends the utility of the purchasing power parity further, by applying the concept of the doctrine to calculating gains or losses incurred by holding foreign items, such as foreign currencies or goods. Relating purchasing power parity to currency changes, the author explain that purchasing power is related to the exchange rates of currencies, in that, differential rates of inflation between, say the United States and a foreign country, influences the exchange rates between the monetary units if each country. Putting this definition into an equation, he states that the calculation of the purchasing power parity can be illustrated thus: If the exchange rate between the United States and a foreign country is 20FC = $1 where FC denotes a unit of ‘foreign currency’, if during the year, the US price level index changed from 100 to 110 and that of the foreign country changed from 100 to 120, the purchasing power parity rate can be calculated by determining an adjustment factor that would be applied to the exchange rate. The adjustment factor is calculated as:   ÃË†t à · Øt = the adjustment factor for period t or (120,100t 110,100) = 1.0909 where ψt =   the price-level ratio in the United States defined as the general price-level index at   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   the end of period t divided by the general price-level index at the beginning of   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   period t Øt = the price-level ratio in the foreign country defined as the general price-level index at   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   the end of period t divided by the general price-level index at the beginning of   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   period t   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Explaining this formula, the author assert that when the adjustment factor is applied to the exchange rate, for the example above, result is FC 20x 1.0909 = FC 21.8182=$1. So, if the actual exchange rate at the end of the time t is at the calculated rate of FC 21.8182 to $1, investors in either country will maintain their purchasing power relative to each other, however, if for example, the exchange rate was to be at FC 22 to $1, FC would have depreciated more than is necessary to maintain the purchasing power parity, and so US investors in need of the foreign currency would have exchanged the currency at a loss. The author went on to establish a multiequation system that can be employed in analyzing potential gains and losses in foreign exchange, based on the purchasing power parity concept. Ruble, L. William (1961). A Comparison of the Parity Ratio with Agricultural Net Income Measures: 1910-1958. Journal of Farm Economics, 43(1):101-112. And Stine O. C. (1946). Parity Prices. Journal of Farm Economics, 28(1):301-305.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   These two works covered a slight different aspect of purchasing power parity. They were focused on the purchasing power of farmers, comparing prices changes in farm and non-farm products, and thus, what farmers are paid for their farm products and what they have to pay to buy non-farm products.   Stine33   explains that in the years after the first World War, when the purchasing power parity concept was birthed and first applied as measurement in of changes in purchasing power, marked changes in general price levels was observed, as expected, however, it was also observed that farm products declined more rapidly and farther compared to non farm products. As a result, what farmers had to pay for products they buy was considerably different from what they earn from the sells of farm products.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Ruble34   supporting this line of argument, argues that since the prices received by farmers and prices paid by farmers affect the livelihood and wellbeing of the farming family, the parity ratio provides a good indicator of the standard of living of farmers. Further, contends that the level of the parity ratio is expected to give   good indication of the following methods of estimating the standard of living of farmers: Net money income per capita, per farm, or per worker. Net real income per capita, per farm, or per worker. Income of farmers compared to income of non-farmers on a per   Ã‚  Ã‚  Ã‚  Ã‚   capita or per worker basis (the parity income concept)   Ã‚  Ã‚  Ã‚  Ã‚   However, data and result of empirical studies was presented to measure the relation between the parity ratio and the well being of farmers suggests that the parity ratio might not indeed properly reflects the general well being of farmers, if the well-being of farmers in general is expressed by the per capita, per farm, or per worker net income, real or money. In arriving at the figures in the table, the parity ratio was correlated separately with the per capita net agricultural income of the farm population, the net income of farm operators from farming per farm, and the net income of farm workers from farming per worker, income from all sources, and deflated by the index of prices paid by farmers for family-living items (1917-19 = 100) Summary   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   There is no denying the fact that the Purchasing Power Parity doctrine is an important theory in the financial world. It is true that a lot of controversies have been generated about its validity and utility, but it is also true that several authors have been able to categorically prove its validity, and more importantly, utility, in an array of fields. Just as the theory has come to mean different thing to different authors, it has also carved for itself, different functions, depending on the perspective one adopts. It is not surprising, therefore, that authors have been able to apply the doctrine to a number of endeavors, as seen in the reviews above.   Ã‚  Ã‚  Ã‚  Ã‚   In its most basic form, the concept argues that people primarily need currencies of other countries for the purpose of buying goods/commodities of that country. Therefore, people will only be prepared to exchange currencies for its relative worth. Here lies the relationship between purchasing power parity and the exchange rates of currencies i.e. when it is suspected that a currency is under or over valued, market forces will tend to force the rate back to the equilibrium level. Equilibrium here describes the rate achieved after trades have occurred between two countries, uninterrupted, for a certain period of time and a common exchange rate has been established, as a result.   Ã‚  Ã‚  Ã‚  Ã‚   From this very basic understanding of the theory, as proposed by the author Prof. Gustav Cassel, several modifications, adjustments, and extension of the theory have been proposed and proved. For example, Bellasa fine tuned the predictive value of the theory by modifying the basic two-country, two-commodity model, to include considerations for non-traded goods (services) and the per capita income of each country, which, he argues, play crucial role in the purchasing power of currencies. Klein and his colleagues   modified the theory and employed it in simulating/projecting changes in world economy; Everett and others , also modified the theory and proved it to be useful in appraising strengths and weaknesses of countries’ currencies; while John   showed that the predictive errors in rates calculated with the purchasing power parity concept could be as a result of  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   faults inherent in the calculation methods and data.   Ã‚  Ã‚  Ã‚  Ã‚   From the foregoing, one can only infer that purchasing power parity is still an important financial concept. Although, further academic and research efforts should be geared towards resolving some of the objections raised against the theory. It is obvious that criticism of the theory will further help to strengthen it, in the future, as we have seen it done in the past. Most of the objections raised have been somehow addressed, even if not completely resolved. One can, thus conveniently conclude that with time, the theory might be better fine tuned and become more effective at explaining and predicting exchange rates of currencies. Endnotes Balassa, Bela (1964). The Purchasing-Power Parity Doctrine: A Reappraisal. Ibid p.584 Klein, R. Lawrence, Shahrokh Fardoust and Victor Filatov (1981). Purchasing Power Parity in Medium Term Simulation of the World Economy; Balassa, Bela (1964) Bunting, H. Frederick (1939). The Purchasing Power Parity Theory Reexamined Bunting (1939) provided almost a word-for-word definition and explanation of the theory as postulated by Cassell. The author gives a better idea of the original theory Ibid p.283 Everett, M. Robert, Abraham M. George and Aryeh Blumberg (1980). Appraising Currency Strengths and Weaknesses: An Operational Model for Calculating Parity Exchange Rates. Ibid p.80 Klein et al., 1981 Ibid   p.486 Belassa, 1964 p.584-585 This is personal opinion based on the definition of the absolute and relative PPP proffered by Bellasa, 1964 Ibid Ibid Belassa, 1964 p.585 quoting Cassel in his book Money and Foreign Exchange After 1914. Ibid   Ibid p.587 Bunting,   H. Frederick (1939). The Purchasing Power Parity Theory Reexamined. Bunting, 1939 p.285 quoting Cassel in his book Money and Foreign Exchange After 1914. Bunting, 1939 p.288 Davutyan, Nurhan and John Pippenger (1985). Purchasing Power Parity Did Not Collapse During the 1970s Balassa, 1964 Davutyan and John, 1985 p.1151 Everett, M. Robert, Abraham M. George and Aryeh Blumberg (1980). Appraising Currency Strengths and Weaknesses: An Operational Model for Calculating Parity Exchange Rates. Ibid p.84 Ibid p.90 Klein, R. Lawrence, Shahrokh Fardoust and Victor Filatov (1981). Purchasing Power Parity in Medium Term Simulation of the World Economy. p.486 Ibid p.487 John, Pippenger (1982). Purchasing Power Parity: An Analysis of Predictive Error Yeager, B. Leland   (1958). A Rehabilitation of Purchasing-Power Parity Ibid p.529 Wyman E. Harold (1976). Analysis of Gains or Losses from Foreign Monetary Items: An Application of Purchasing Power Parity Concepts. Stine O. C. (1946). Parity Prices Ruble, L. William (1961). A Comparison of the Parity Ratio with Agricultural Net Income Measures Bibliography Balassa, Bela (1964). The Purchasing-Power Parity Doctrine: A Reappraisal. The Journal   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   of Political Economy, Vol. 72:6 pp. 584-596. Bunting,   H. Frederick (1939). The Purchasing Power Parity Theory Reexamined.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Southern Economic Journal, Vol. 5:3. pp. 282-301. Davutyan, Nurhan and John Pippenger (1985). Purchasing Power Parity Did Not   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Collapse During the 1970s. The American Economic Review, Vol. 75:5.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   pp.1151-1158. Everett, M. Robert, Abraham M. George and Aryeh Blumberg (1980). Appraising   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Currency Strengths and Weaknesses: An Operational Model for Calculating   Ã‚  Ã‚   Parity Exchange Rates. Journal of International Business Studies, Vol. 11:2. pp.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   80-91. John, Pippenger (1982). Purchasing Power Parity: An Analysis of Predictive Error. The Canadian Journal of Economics, Vol. 15:2, pp. 335-346. Klein, R. Lawrence, Shahrokh Fardoust and Victor Filatov (1981). Purchasing Power   Ã‚  Ã‚   Parity in Medium Term Simulation of the World Economy. The Scandinavian   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Journal of Economics, Vol. 83: 4 pp. 479-496. Ruble, L. William (1961). A Comparison of the Parity Ratio with Agricultural Net   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Income Measures: 1910-1958. Journal of Farm Economics, Vol. 43:1. pp. 101-  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   112. Stine O. C. (1946). Parity Prices. Journal of Farm Economics, Vol.28:1. pp.301-305. Wyman E. Harold (1976). Analysis of Gains or Losses from Foreign Monetary Items: An   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Application of Purchasing Power Parity Concepts. The Accounting Review, Vol.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   51: 3. pp. 545-558. Yeager, B. Leland   (1958). A Rehabilitation of Purchasing-Power Parity. The Journal of   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Political Economy, Vol. 66:6, pp. 516-530.

Wednesday, October 2, 2019

Emerging Threat of Invasive Fungal Infections

Emerging Threat of Invasive Fungal Infections Introduction Emerging threat of Invasive Fungal Infections Invasive fungal infection continues to be a major problem associated with high morbidity and mortality mainly to immunocompromised patients as well as to immunocomptent patients but to a much lower extent. (1) Invasive fungal infection and fungemia are caused by a variety of fungal pathogens. The most commonly isolated yeasts are Candida species (spp.) and Cryptococcus spp. Aspergillus species remains the most common mould however, Fusarium spp., Scedosporium spp., Penicillium spp. and Zygomycetes are increasingly isolated.(2) Patients mostly become colonized during hospitalization however, very few patients who become colonized develop sever infection. Nosocomial fungal infections can represent up to 15% of all nosocomial infections.(3) The spectrum of opportunistic invasive fungal infections has increased substantially owing to the rapidly growing population of immunocompromised patients.(4) Due to lack of specificity of symptoms diagnosis of fungal infections can be challenging.(3 ) Candida infections are mostly prevalent in critically ill patients in intensive care units (ICUs) and very low birth weight infants. Candidaemia is highly fatal with a reported mortality in the range from 36% to 63%.(5) In the recent years, mortality rates in ICU patients have decreased substantially probably due to earlier initiation of antifungal therapy.(6) Conversely, aspergillosis is the most common fungal infection in immunocompromised most specifically in haematological malignancy and haematopoietic stem cell transplantation (HSCT) patients. Incidence of aspergillosis has increased considerably but mortality has decreased owing to better diagnosis and treatment.(7) Treatment of Invasive Fungal Infections Treatment and prophylaxis of invasive fungal infections involves systemic antifungal therapy. Historically amphotericin B and Flucytosine have been the only available antifungals; these were followed by the development of the older triazole antifungals; fluconazole and itraconazole in the late 1980s. More recent advances have led to the release of amphotericin lipid formulas, newer broad spectrum triazoles (voriconazole, posaconazole) and the newest class of echinocandins.(8) Amphotericin B either as a deoxycholate or in lipid formulations has been the backbone of antifungal therapy for many years. The triazole antifungals have also emerged as front-line treatment and prophylaxis for many systemic fungal infections. Triazole antifungals used systemically include fluconazole, itraconazole, posaconazole and voriconazole. Fluconazole has a major role in prophylaxis and treatment of both invasive and superficial fungal infection. Voriconazole is the drug of choice in invasive aspergillosis of the lung. Posaconazole is used as a salvage therapy for invasive aspergillosis as well as a prophylaxis in HSCT and neutropenic patients.(9) Itraconazole is active against most fungi except for Zygomycetes.(10) Terbinafine which is widely used in skin infections is also effective against systemic candidiasis including vulvovaginal candidiasis although less effective than fluconazole and itraconazole.(11,12) Flucytosine is used in combination with amphotericin B for treat ment of severe systemic mycoses and has also in combination with other antifungals for treatment of colorectal carcinoma.(13) Echinocandins Introduced Despite the advantages in medical practice and introduction of newer agents, mortality due to fungal infections remained high with mortality due to Aspergillus approaching 100% in HSCT patients.(14,15) There has also been a change in epidemiology of fungal infections with non-albicans species reaching up to 50% with no significant change in mortality in spite of these newer agents in two studies conducted 15 years apart.(16,17) Echinocandins is a newer class of systemic antifungals introduced after almost 15 years of no new agents. They work by inhibiting ÃŽ ²-D glucan in fungal cell wall. Echinocandins have favourable kinetics which allows their once daily dosing. (18) The first echinocandin product to be licensed is caspofungin (FDA approved in 2001), that was followed by micafungin (FDA approved in 2005), and anidulafungin (FDA approved in 2006). (19)The discovery of the echinocandin antifungals has provided a new alternative for patients with equal if not higher efficacy relative to older agents and apparently lower toxicity.(20,21) Echinocandins are extensively used in the treatment of invasive fungal infections mainly invasive candidiasis in neutropenic and critically ill patients.(22)They are also approved as a salvage treatment for invasive aspergillosis.(23) The major advantage of the echinocandins members is their higher efficacy against many candida species including C. glabrata and C. krusei res istant to fluconazole added to their lower toxicity rates compared to older antifungals.(20,21,24) The Infectious Diseases Society of America (IDSA) recommends echinocandins as first line treatment of Candidaemia while caspofungin is offered as an alternative to voriconazole for treatment of invasive aspergillosis.(22,23) Echinocandins showed equal efficacy to triazole antifungals and even superior efficacy in subgroup analysis since it demonstrates superior efficacy for prophylaxis in patients with hematologic malignancies and undergoing HSCT.(25) Echinocandins Safety Treatment of fungal infections is challenging and riddled with adverse events. (26,27) Echinocandins showed no difference in drug related adverse events and all-cause mortality as compared to triazole antifungals where both groups have shown to be generally well tolerated, nevertheless, echinocandins has significantly decreased adverse event related mortality compared to triazole antifungals.(25) Echinocandins have revealed hepatic toxicity in clinical trials yet the incidence is considered low.(28) The most commonly reported toxicities associated with echinocandins in clinical trials are rash, phlebitis, and nausea. The renal profile of this class appears to be superior to that of older agents.(29,30) Serious adverse events reported with echinocandins in the context of clinical trials are very few with atrial fibrillation and seizures in two cases treated with anidulafungin and disseminated intravascular coagulation in another one treated with micafungin.(31,32) Unfortunately, till now there is insufficient data on the frequency of hepatic and renal toxicities in normal clinical settings although they have already been reported in context of clinical trials. Moreover, as these agents became more widely used outside clinical trials, new adverse reactions are surfacing. Anidulafungin has been reported to be associated with alopecia in a female patient after several months of treatment.(33) Anidulafungin has also been associated with life-threatening haemodynamic stability in another patient during administration.(34) Three cases has shown a considerable drop in their cardiac index or a worsening of the mean arterial pressure, one following caspofungin administration and the other two post anidulafungin administration.(35) Echinocandins has also been associated with a decrease in cardiac contractility in few case reports and in vitro studies which warrant further investigations.(36,37) Further studies seem to be mandatory to investigate this po tential risk. Limitations on Detecting Risk Pre-marketing studies are incapable of detecting rare events. In addition due to their short duration they are also unable to detect delayed toxicities. It’s worth noting that to detect doubling of a 0.1% event with 80% power; more than 50,000 subjects need to be studied. This leads to drugs being authorized without serious rare events are adequately studied. One cannot also be sure that the safety profile demonstrated in the pre-marketing clinical trials with limited number of subjects remains unchanged when used by millions of patients in normal settings. This difference in safety profile demonstrated is not only attributed to difference in number of users but may also be due to choosing of healthier subjects to participate in clinical trials, providing better care to clinical trials participants in addition to shorter duration of exposure in clinical trials as compared to normal settings. This difference in safety profile may as well be attributed to the fact that participa nts in clinical trials are rarely representative to the general patient population. (38,39) Post Marketing Risk Detection Pharmacovigilance is defined as the continuous process of detecting, evaluating, communicating and improving safety of medicines under normal conditions.(40) Post marketing data on adverse events include spontaneous case reports, medical record databases, and data collected in prospective postmarketing studies.(41) Spontaneous reports are unsolicited reports of clinical observations originating outside of a formal clinical trial and that are submitted to regulatory agencies or drug manufacturers.(42) The report is considered important if it involves an ADR that is new, rare, serious or occurring at a higher frequency than expected.(43) Spontaneous reporting systems have a potential for detecting or ‘signalling’ new ADRS that have not been previously recognized in clinical trials.(38) The most crucial factor that determines the value of spontaneous reports is the quality of submitted reports and whether it has a complete description of the ADR, patient demographics, baseline characteristics other confounding factors or medication and temporal relation.(42) Signal detection using large postmarketing ADRs databases is the first step in detecting unknown and unexpected associations between drug exposure and adverse events which has to be followed by qualitative case-by-case analysis to identify signals that may be of value or warrant further investigation.(44,45) Safety evaluators usually look at common trends or patterns or and potential causal relations. (42) Advantages and Limitations of Spontaneous Reporting In all countries, the nation pharmacovigilance system relies on spontaneous reporting by healthcare practitioners, patients and manufacturers to the national coordinating center.(46) Spontaneous reporting is the only source of pharmacovigilance that provides the highest volume of data at the lowest cost.(47) The most important function of spontaneous reporting is early detection of signals which helps in hypothesis formulation that may lead to initiation of confirmatory investigations or regulatory actions that may end up with warnings, label changes or product withdrawal.(48,49) Large postmarketing databases are the most important source for mining of drug safety data, however, analysing data from these databases is very challenging owing to the limitations of these unsolicited reporting systems.(50) One of the most important limitations of spontaneous reporting is the quality of data since cases are mostly poorly documented with no follow up data which necessitates contacting the reporter for more data.(42) Another limitation is under-reporting whose extent is very hard to estimate and which depends on many factors including the severity of the reported ADR among many other factors.(51,52) Reporting rate also undergoes fluctuation along the drug life cycle with higher rates noticed when the drug is newly introduced to the market (weber effect). Higher reporting rates are also noticed for serious medical events or after negative publicity. (53) It’s estimated that FDA receives only 1% of ADRs in one study and 8% in another of all occurring ADRs which affects is reflected on the inability of spontaneous reporting system to estimate incidence of a specified ADR. (54,55) Role of Data mining in Pharmacovigilance The role of data mining in the field of pharmacovigilance is evolving. At the outset, it’s worth noting that data mining methods involve identifying the observed relation between a drug and a certain ADR. These relation identification methods are based totally on the frequency with which the drug and event are reported. The relations identified using these data mining techniques cannot be used to prove or negate a causal relation.(50) Data mining methods can elucidate complex drug issues such as concomitant medications or conditions that may not be investigated using traditional methods. However, this is usually confronted by the non-systematic attainment of background rates of adverse events and drug exposure data which hinder estimation of risk based on spontaneous reporting databases.(56,57) In the context of data mining, the term ‘signal’ is used to refer to a quantitative association between a drug and an event which exceeds a certain threshold set by the investigator that warrant further evaluation. The ‘signal score’ is the number reflecting the strength of the quantitative association which reflects how much the observed frequency differs from that expected.(50,56,58) The application of computational and statistical methods to large drug safety databases for identifying drug-event pairs disproportionately reported at higher frequency than expected by a statistical independence model is referred to as ‘Safety data mining’ and ‘disproportionality analysis’. Many data-mining methods are applied to pharmacovigilance; the ones that are most commonly reported in the literature are the proportional reporting ratio (PRR) and the reporting odds ratio (ROR) in addition to the Bayesian and empirical Bayesian methods.(59–62) Signal Detection Methods Disproportionality analysis is the main concept behind computerized pharmacovigilance methods. Disproportionality analysis is dependent on the construction of a 22 contingency table as shown in table (1). (63) Disproportionality methods differ in how they are calculated and how they account for low counts. They are generally classified into Frequentist and Bayesian approaches. Drug of interestOther drugs Event of interestab Other event cd Table 1: Statistical significance in spontaneous reporting is calculated using the frequencies in the table above Frequentist approaches Frequentist approach usually accompanied by hypothesis testing of independence using chi-square or Fisher’s exact test.(64) Proportional reporting rate (PRR) or Case/Non-case design PRR can be considered as an approximation of conditional probability and is calculated using the following equation: PRR= = a/(a+c) à · b/(b+d). Where a/(a+c) can be perceived as the probability of developing the event of interest given that the drug of interest is taken and an event in turn, b/(b+d) can also be perceived as the probability of developing the event of interest given that another drug is received given that any other drug is taken and an event occurred.(63) PRR is a valuable aid to signal generation which is easy to calculate and interpret with various refinements made possible.(59) Reporting Odds Ratio ROR is a ratio of two ratios and is calculated according to the equation: ROR= a/bà ·c/d where a/b is the ratio of the patients who had the event of interest a divided by the number of patients who had the event while taking other medications. This ratio in turn is divided by c/d which is calculated by dividing all patients who had the drug of interest but did not have the event of interest by all other patients who did not have the event of interest given that they took any other drugs. (63) ROR is not affected by general under reporting for a specific drug or as specific event.(65) It has been proposed that ROR may be less biased than other disproportionality methods being considered as the case-control studies analysis.(66) Nevertheless, others believe that in practice there is no difference in performance between ROR and PRR.(60,67) Bayesian approaches Bayesian approaches tries to account for uncertainty in disproportionality measure calculated from small samples by shrinking the disproportionality measure towards baseline case of no association. This shrinking is a reduction of spurious associations when there are not enough data to support it and is proportional to the variability in the disproportionality statistics.(64) The Bayesian approaches include Multi-item Gamma Poisson Shrinker (MGPS) which is currently used by the FDA.(68,69) MGPS is based on an empirical Bayes framework and its computed measure is called empirical Bayes geometric mean (EBGM) which is the Bayesian version of the Relative Reporting Ratio (RRR). RRR is the ratio of the incidence of the observed incidence rate of a drug-event pair to its expected rate under the assumption that the drug and event are independent.(70) Another Bayesian approach adopted by the WHO is called Bayesian Confidence Propagation Neural Network (BCPNN), which estimates a Bayesian version of the Information Component (IC). A positive IC indicates that based on all reports in the database the drug-event pair is reported more often than expected. (61) Postmarketing Safety Databases for Signal Detection Databases utilized in drug safety data mining are postmarketing databases maintained by manufactures, regulators and different consortia. These databases are different in their reporting guidelines, coding dictionaries and rules for data entry. These databases vary in size and may reach millions of reports. The analysis of these databases may yield different results and so a single database available to all stakeholders is needed. Ideally this database will not have duplicate reports or missing data and is consistently coded for drug and event name. A number of databases are commonly available for signal detection activities, however; they differ in accessibility. These include the database of the WHO International Drug Monitoring Programme and the FDA’s public release safety database (AERS).(50) WHO Safety Database The WHO safety database is a large database receiving AEs from the national collaborating centers participating in the WHO Drug monitoring program.(71) It has the advantage of having the drug names coded according to the Anatomical Therapeutic Chemical (ATC) classification and ADRS are coded using the WHO Adverse Reaction Terminology. However, data is accessible by subscription only.(68) European Medicines Agency EudraVigilance database The EMEA pharmacovigilance system is called the EudraVigilance. It has 2 modules one for clinical trials and another for post marketing surveillance. It has analytical capabilities and performs signal detection in terms of PRR and ROR. It has restricted access even to manufacturers who can only see reports that they have submitted to the EMEA.(72) US FDA Adverse Event Reporting System (AERS) AERS is the FDA’s postmarketing safety database. AERS database is intended to support the FDAs post-marketing safety surveillance program for drugs. It relies on unsolicited reports submitted by healthcare professionals and patients on adverse events and medication error reports as well as required reports by manufacturers and so represents a useful resource for investigating drug safety.(73) The public-release version of AERS is available beginning with January 2004 as quarterly data directly downloadable from the FDA website. The new FDA FAERS was launched in the 10th September, 2012, and replaced the Adverse Event Reporting System (also known as Legacy AERS).(74) The main aim of the current study is to: Map the safety profile of echinocandins antifungals.as compared to other drugs. Compare the safety profile of echinocandins to that of other systemic antifungals. Assess the effect of changing the reference group on the top signals identified. To achieve these aims data mining methods and disproportionality analysis will be employed to the FDA AERS to achieve these aims. This study will therefore add to the knowledge on the safety profile of this newer class of antifungals.

Special Topics In Communications :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Communication is defined as creating symbol systems that can be used to exchange and express information and meanings. The different ways that individuals, groups and societies use these expressions to make sense of daily life is know as their culture. Culture itself can be divided into two classifications. Culture spelled with a capital C is usually associated with art such as classical music, opera, ballet and art museums. These examples can also be called â€Å"high culture†. Culture with a lowercase c represents the way people live through fashion, sports, religion, education and history.   Ã‚  Ã‚  Ã‚  Ã‚  Each culture is a different audience. Mass media takes the audience in consideration to provide information that is relevant to them. Media will target people based on age, gender and race to produce programming or text that each will relate to. When the popular teen drama Dawson’s Creek first aired in 1997, I was 17. The program was intended to reach out to my age group on issues that were important to us. For about a year and a half I was a Dawson’s Creek expert, knowing in detail about the characters and the storylines. Soon after high school I grew restless with the show. I realized it no longer appealed to me because I had grown out of the show. The same network has since come out with programs for the college age group that I now watch. Networks know that they must change just as fast as their audience to keep them. There are many types of mass media today that are available to a large number of people on a daily basis. Sources of mass media and mass communications include newspapers, movies, television programs, radio, books and magazines. Of these mediums, the Internet is the fast growing type of mass communication. I first began using America Online in 1999 for chat rooms. I would go in the rooms and talk to people my age that lived in my area. It was a new way to communicate with people about whatever I wanted. I then noticed people using the chat rooms for a source of spreading their ideas about racism, sexism and general malaise. I believe that most output from the Internet is positive. The Internet is a convenient tool for education, news, entertainment, business and personal communication. Although with a resource with large, hate groups are also going to try and spread their message to the masses. Special Topics In Communications :: essays research papers   Ã‚  Ã‚  Ã‚  Ã‚  Communication is defined as creating symbol systems that can be used to exchange and express information and meanings. The different ways that individuals, groups and societies use these expressions to make sense of daily life is know as their culture. Culture itself can be divided into two classifications. Culture spelled with a capital C is usually associated with art such as classical music, opera, ballet and art museums. These examples can also be called â€Å"high culture†. Culture with a lowercase c represents the way people live through fashion, sports, religion, education and history.   Ã‚  Ã‚  Ã‚  Ã‚  Each culture is a different audience. Mass media takes the audience in consideration to provide information that is relevant to them. Media will target people based on age, gender and race to produce programming or text that each will relate to. When the popular teen drama Dawson’s Creek first aired in 1997, I was 17. The program was intended to reach out to my age group on issues that were important to us. For about a year and a half I was a Dawson’s Creek expert, knowing in detail about the characters and the storylines. Soon after high school I grew restless with the show. I realized it no longer appealed to me because I had grown out of the show. The same network has since come out with programs for the college age group that I now watch. Networks know that they must change just as fast as their audience to keep them. There are many types of mass media today that are available to a large number of people on a daily basis. Sources of mass media and mass communications include newspapers, movies, television programs, radio, books and magazines. Of these mediums, the Internet is the fast growing type of mass communication. I first began using America Online in 1999 for chat rooms. I would go in the rooms and talk to people my age that lived in my area. It was a new way to communicate with people about whatever I wanted. I then noticed people using the chat rooms for a source of spreading their ideas about racism, sexism and general malaise. I believe that most output from the Internet is positive. The Internet is a convenient tool for education, news, entertainment, business and personal communication. Although with a resource with large, hate groups are also going to try and spread their message to the masses.

Tuesday, October 1, 2019

Illuminating The Path Of Progress :: essays research papers

Illuminating the Path of Progress Thomas Alva Edison is the most famous inventor in American History. Edison designed, built, and delivered the electrical age. He started a revolution that would refocus technology, change life patterns, and create millions of jobs. He became famous for his scientific inventions, even though he was not a scientist. His real talent was his ability to clearly judge a problem and be persistent in experimenting. He was the master of the trial and error method. Thomas Edison was born on February 11, 1847 in Milan, Ohio. He was the last of seven children born to Samuel and Nancy Edison. Edison's early life was spent in Ohio near the nation's busiest grain port. He spent time exploring the canal and played near his father's shingle business. When Alva was a child, he had scarlet fever. The fever damaged his hearing and delayed his entrance into school. Edison was curious about the world around him and always tried to teach himself through reading and experiments. Alva spent three years in home schooling. He was taught by his mother. He later returned to school but left at age twelve to get a job and help support his family. Edison got his first job selling newspapers and snacks to the passengers on the train between Port Huron and Detroit. Edison bought a used printing press in 1862 and published the Grand Trunk Herald for passengers. It was the first newspaper published on a train. When Edison was fifteen, he was taught Morse code and became a manager of a telegraph office. Edison got the idea for his first invention from working here. His first inventions were the transmitter and receiver for the automatic telegraph. At 21, Edison produced his first major invention, a stock ticker. In 1869, when Edison was twenty-two, he patented his first invention and advertised that he would devote his time to bringing out his inventions. The first patent received by Edison was for a vote recorder. Years later Edison's design was put in use by state legislatures for use by the public in general elections. By the age of twenty-three Edison owned two factories to manufacture telegraphic equipment and had money to pursue his research. On December 25, 1871, Edison married Mary Stilwell. They had three children. Two of his children were nicknamed Dot and Dash after the Morse code. In 1880 Edison made a discovery in science. He noticed that when a metal plate was inserted into a light bulb, the plate became a valve and the current could be controlled. This discovery is known as the "Edison Effect.

Antitrypsin Deficiency: The Genetic Disorder

Alpha-1 Antitrypsin Deficiency (AAD) was first described in 1963, and of the five patients identified, three were found to have severe emphysema at an early age. Subsequent studies that the deficiency was inherited, and in most of the early studies, emphysema and chronic bronchitis were common features.The deficiency was shown to be associated with a marked reduction in the ability of the plasma to inhibit the serine proteinase trypsin, and later studies showed that this also reflected an inability of the serum to inhibit the enzyme neutrophil elastase (Pauwels, Postma, and Weiss, 2004 p.446). Human neutrophil elastase was shown to produce both emphysema and chronic bronchial disease in animal models. Emphysema can be directly inherited via a single gene defect. The genetic disorder, known as alpha-1-antitrypsin deficiency, results from a defective gene transmitted by each parent equally to the affected offspring. This gene codes for the enzyme antitrypsin, which, when deficient, res ults in the loss of normal lung elasticity and in progressive overinflation and destruction of lung tissue.Antitrypsin deficiency is also the most common genetic cause of childhood liver disease (cirrhosis) and the most common reason for liver transplantation in children. A family history of early onset emphysema or childhood liver disease points toward this diagnosis, which can be confirmed by DNA analysis. DNA testing can be used to detect carriers of alpha-1-antitrypsin deficiency as well as to facilitate prenatal diagnosis for a couple found to be carriers, who face a 25 percent risk of having an affected child (Millunsky, 2001 p. 128-129). Scope and LimitationsAAD is one of the rarest diagnosed conditions in our current time; hence, focused study of such condition is essential. The case study involves the subject of pathological conditions linked with the condition of progression of defective genetic manifestations. Utilizing physiological and genetical approach, we shall cente r into the discussion of the disease causation, processes and manifestations involved. It is indeed essential to employ the principles of wellness and its components. The following shall be utilized in the overall study. A.To be able to determine and elaborate the actual disease processes involved, as well as the disease conditions manifested B. To be able to relate genetic causalities and factors in the aspects of disease progression utilizing the domains, components, and principles of wellness C. To be able to provide necessary health interventions, suggest enhancing lifestyle modifications and preventive behaviors related to the condition imposed Purpose of the Study The value significance of this study provides awareness to the public especially in terms of what can these contributing factors impregnate to the condition occurrence.Most likely, the degenerative character of AAD is very much rehabilitated if this awareness is enhanced through education. The study mainly expands he alth awareness on both AAD patients and non-patients who are greatly may or otherwise exposed in factors that contribute to its genetic occurrence. Moreover, the knowledge on this topic may further aid the patients and those involved in the reduction of anxiety and ignorance of the condition imposed. Discussion The Functions of ? 1-Antitrypsin and Involved MediatorsBlood and other body fluids contain a serum protein classified as an alpha-a globulin that is capable of neutralizing trypsin and many other proteolytic (protein digesting) enzymes such as fibrinolysis and thrombin (Bross and Gregersen, 2003 p. 39; Crowley, 2004 p. 399). This specialized protein is called alpha-1 antitrypsin, and its concentration in the blood is generally determined. Most individuals produce normal amounts of antitrypsin, others are severely deficient, and a third group have subnormal levels of this protein (Crowley, 2004 p. 399).?1-Antitrypsin (AA) is an inhibitor of serine protease in general but its m ost important targets are neutrophil elastase, cathepsin G, and proteinase 3, proteases released by activated neutrophils. Several line of evidence suggest that inhibition of these neutrophil proteases is the major physiologic function of AA (Bross and Gregersen, 2003 p. 39). †¢ First, individuals with AAD are susceptible to premature development of emphysema, a lesion that can be induced in experimental animals by instillation of excessive amounts of neutrophil elastase.These observations have led to the concept that destructive lung disease may result from the perturbation of the net balance of elastase and AA within the local environment of the lung. †¢ Second, the kinetics of association for AA and neutrophil elastase are more favorable, by several orders of magnitude, than those for AA and any other serine protease. †¢ Third, AA constitutes more than 90% of the neutrophil elastase inhibitory activity in one body fluid that has been examined, pulmonary alveolar la vage fluid (Suchy, Sokol, and Balistreri, p. 549).AA is the archetype of serine protease inhibitor (SERPIN) supergene family. Its primary function is inhibition during the host response to inflammation/tissue injury, for which it has been termed a hepatic acute-phase reactant (Suchy, Sokol, and Balistreri, p. 549; Bross and Gregersen, 2003 p. 39). AA acts competitively by allowing its target enzymes to bind directly to a subrate-like region within its reactive center loop. The reaction between enzyme and inhibitor is essentially second order, and the resulting complex contains one molecule of each of the reactants (Bross and Gregersen, 2003 p.39; Fessler, reiley and Sugarbaker, 2004 p. 155). A reactive-site peptide bond within the inhibitor is hydrolyzed during the formation of the enzyme-inhibitor complex. Hydrolysis of this bond; however, does not proceed to completion (Suchy, Sokol, and Balistreri, p. 549). The predominant site of synthesis of plasma AA is in located biologically in the liver wherein in most clearly shown by conversion of plasma AA to the donor phenotype after orthoptopic liver transplantation (Bross and Gregersen, 2003 p.39; Suchy, Sokol, and Balistreri, 2007 p. 551). It is synthesized in human hepatoma cells as a 52-kDa precursor; undergoes post translational, dolichol phosphate-linked glycosylation at three asparagines residues, and undergoes tyrosine sulfation. It is secreted as a 55-kDa native single-chain glycoprotein with a half time for secretion of 35 to 40 minutes (Suchy, Sokol, and Balistreri, 2007 p. 551). The absence or insufficiency of AA initiates genetic anomaly in terms of failure to suppress immunity response (Porth, 2007 p. 501).