Valuation of Futures Contracts Assignment Example | Topics and Well Written Essays - 750 words

Valuation of Futures Contracts - Assignment Example The future looks gloomy for this stock Factors affecting perfomance of cooprate bond Prevailing interest rates Idealy corprate bonds offer better yield prospects than government bonds but that’s because of the risk involved. This is happens so as to entice the investors to turn their attention away from the treaeury bonds and securities. Since most often than not, the performance of corprate bonds are pegged against that of treasury bonds. The prices at which the later are quoted really maters, the amount of yield they produce also matters a lot. When the yield of a bonds future is less than that of prevailing treasury bonds, such a bond is considered to be under performing. When the Government issues bonds at better prices than that of the corporate bonds the demand shifts to the government bonds thus the laws of demand and supply come into play hence forcing the corporate bond’s price to dip. The opposite happens when the government bonds are not that attractive which is very rare. Overal perception of the investor Whenever global news headlines are positive and encouraging, investors tend to be more open minded and open to opportunities across the globe. At such times they are willing to put out their money because they are confident of a good return on investment thanks to a good business climate moving forward. The opposite happens when there is turmoil and conflict; most investors tend to hold on to their money during such periods. Some investor even consider divesting from markets they consider to be to risky or adversely affected by the negative news. They focus more into secure investments such as treasury bonds and securities. If a company is trading in an environment considered being risky at a particular time by portential investor, those investors may choose to shy away from the corporate bonds issued by that compnay and such an action may affect the price of the bond negatively. Political developments or natural disasters in an econo my half way across the world can greatly affect the performance of a stock locally. A good case in point is the earth quakes and Tsunamis. Political activities also do influence price flactuations in a corprate bond. Usually investors shy away from ecomonies that have unstable political environments, especially when such a countries are having elections or revolutions. Overall finacial health of a company The overall financial health of a company is of paramount importance. A company’s ability to maintain high profits increase investor apetite and confidence therefore a corprate bond issues by that company at such a time would fetch very high prices. This is because investors like being assoiated with performing companies thus making them more reluctant to sell the bonds they hold with such companies which results into low yields but rising prices. The opposite happens when a company reports losses. Such reports really vex investor confidence to the extent that some start to doubt weather that Particullar Company will be able to pays their debts to the investors. Such doubts can prompt investors to damp the bonds of that campany into the market thus increasing the yield but reducing prices. Credit rating agencies such as Standards & Poors also do affect the perfomance of a corprate bond. These credit rating agenc

Aberdour Coursework Example | Topics and Well Written Essays - 250 words

Aberdour - Coursework Example In the first two figures (provided that those two were from the same shore) the zonation pattern of the species varies a lot in the same species. So it is an interesting point to note as well as to research. Comparison between the Zonation Pattern of transects from Site A and B:- Transects from site A and Site B were from the same shore, although they have a lot of difference in their zonation pattern. Looking at both the figures given, Ascophyllum nodosum has totally different represented structure in the second figure as compared to first. Max scale level in the first figure is in C group, but in the second figure, it is only included in F group. Limpets also have different represented structure in the second figure as compared to first. Max scale level in the first figure is in C group, but in the second figure, it is only included in O group. Difference between Exposed Shore and Sheltered Shore Sheltered rocky shore is one where on earth the tide/waves cannot crash onto it; such as one where within a bay offering is some protection. Exposed rocky shore is a short time ago the opposite, nil to stop waves crashing onto it. Exposed can be worse for deep-sea life as the pounding of the top can damage some organisms e.g. could construct them lose their grip on the rocks. Further, organisms that can withstand the exposed shore are prone to less predatory effects and as a consequence can survive longer.

JPMorgan Chase Research Paper Example | Topics and Well Written Essays - 750 words

JPMorgan Chase - Research Paper Example 1. Discussion on How Administrative Agencies Like The Securities And Exchange Commission (SEC) Or The Commodities Futures Trading Commission (CFTC) Take Action In Order To Be effective in preventing high-risk gambles in securities / banking, a foundation of the economy In the modern day context, financial sector forms a major part in the economic system of any country, irrespective of its global positioning. The fact can also be observed evidently even in the case of the US, which faced massive turmoil due to the downfall of JPMorgan Chase, a large financial services firm supposedly considered to a pillar of the US economy. In order to maintain legitimacy in these firms, the US government has been making attempts to regulate the financial dealings and the transparency of these organizations through the imposition of various policy measures. Correspondingly, many governmental bodies have been set-up, which are solely responsible to monitor the activities of the US financial system. For instance, the administrate agency, Commodities Futures Trading Commission (CFTC) helps in regulating the trading of options and futures as well as the banking sector. The CFTC, in order to prevent the high risks in securities or banking sectors, has been involved in implementing effective programs to trace and take actions against unethical behavior in the business process. Therefore, it protects the economy from many types of frauds related to commodity market, foreign currency trading, commodity pool participants and brokers activities (U.S. Commodity Futures Trading Commission, n.d). The important elements, which are required to form a valid contract, usually involve an offer with a legal purpose by the offeror, free consent of the offeree, acceptance, consideration, competent parties, mutuality of obligation (Texas.gov, n.d.). Today, in the US, the customers are considered as a valuable asset for the banks

Writer's choice Essay Example | Topics and Well Written Essays - 500 words - 10

Writer's choice - Essay Example Women have for long suffered the effects of such atrocities since it is almost acceptable that they deserve the demeaning treat. You are then left to wonder what driving force must have marshaled such devastating thought (Quisar, Hameed & Aamar, 174-175). Much is already known that has been done to discriminate against the woman, however the question stays; that what is this that has consequentially led to such a looming crisis which unfortunately doesn’t seem to go soon? This leaves us with this inevitable task of crisscrossing the fundamentals amounting to gender biases. This underlying conception turns out to be a belief system set by the society. It is by the societal branding that women play such a demeaning role of subjects to all mannerisms. This in effect lowers their esteem which eventually makes them live in a sense of denial. It is kind of a bias that acts like an undue punishment that a negative yet lasting results. I may liken this to a classroom scenario that involves a teacher and a student. The teacher who keeps on giving negative remarks when the student answers a question, would make this student believe that they aren’t good enough to race on with the rest (Quisar, Hameed & Aamar 174). Few examples in real life situation back up this topic. One, it is evident that men play most leading roles in formal organizations and structures. In top management hierarchies, there is male domination on a global scale based on detailed observation of their profiles. The converse is unfortunately true that the female sex dominates the lower level ladders of such hierarchies. This overwhelming population at the lower ranks is to compensate for their biasness in the top hierarchy; which again gives a misconception of gender balance (Quisar, Hameed & Aamar 176). Unfortunately this undoing also is also reported in most of the cases in homes. Couples have yet more often confirmed that gender biasness and

In each industry, technology determines industrial structure, which Essay

In each industry, technology determines industrial structure, which determines the conduct of firms, which in turn determines the performance of firms. Explain and critically evaluate this statement - Essay Example However the reflection of this relationship would be quite clearly evident in relation with the entity’s market performance. In a larger macroeconomic context, such technological changes are in a broader sense expected to make impacts in the economy my as well. The level to which technology would affect the performance of an industry is however heterogeneous. This would mean that the micro level response of various firms to technological innovations and policy changes would vary to a larger extent (Smith K ,1999). However while analysing the macro level relationship, an evident sign of linkage can be found between the industry’s performance in the global scenario and the technology. This linkage has been found in the history of any industry. To understand the relevance of this statement the replacement of many traditional hand driven industries with automated technologies would be an ideal example. Ranging from agriculture to oil mining, technology always has changed the face and structure of the specific industry as per the standards of the age. However it is true that there are many other factors which drive the technological innovations specific to each industry. From the experiences in the history, it is quite evident that technology would bring massive change in the industrial structure both generic and specific to individual firms. Along with the relation of the structural changes with the performance of individual firms, it also important to understand the integration of these individual changes into complex social and economic relationships with their environments (Smith K ,1999). There are number of theories explaining the macro effect of the structural changes in the industry in relation with technology. This theory is based on the disequlibrium growth model based on creative destruction. It clearly proves the relationship of performance and growth of the industry with the introduction of substantial changes in

The Rising Costs of the Iraq War Essay Example for Free

The Rising Costs of the Iraq War Essay In the 2003 Budget the government set aside ? 3 billion to cover â€Å"the full costs of the UK’s military obligations† in Iraq [1]. In the past four years the amount allocated to this ‘Special Reserve’ has steadily increased, and with an extra ? 400 million in this year’s Budget the total is now over ? 7. 4 billion. This is in addition to recent increases in general military spending. This briefing investigates the financial costs of the Iraq conflict to the UK taxpayer. It notes a significant opaqueness in the budgeting process as well as the potential for costs to continue to escalate. The financial costs of a war may not be the first consideration. War brings many costs, foremost in lives lost and damaged. However, the decision to involve the UK in the invasion of Iraq had substantial implications for UK public spending. Money spent on the Iraq war and wider ‘war on terror’ represents significant diversions from other government budgets. The lack of transparency in the UK finances is in contrast to the US, where all budgetary proposals must be scrutinised by Congress. Comprehensive information about US military spending is available and has contributed to considerable public debate. The sums spent by the US government are many times those of the UK, and there are a number of projects aimed at publicising the scale of US war spending (e. g. http://costofwar. com). The Special Reserve The 2002 Pre-Budget Report set aside ? 1 billion to enable the armed forces to prepare for the coming invasion of Iraq[2]. By the time of the Budget in March 2003, UK forces were in Iraq. The Chancellor increased the amount to ? 3 billion and it became known as ‘the Special Reserve’[3]. In the 2003 Pre-Budget Report another ? 500 million was added for financial year 2003-04 and a further ? 300 million for 2004-05; bringing the total up to ? 3. 8 billion[4]. While there was no increase in the 2004 Budget Report, another ? 520 million for 2004-05 was announced in the Pre-Budget Report of December that year[5]. The 2005 Budget Report included a further ? 340 million added for 2004-05 and ? 400 million for 2005-06[6], whilst the 2005 Pre-Budget Report included another ? 580 million . The 2006 Budget report allocated ? 800 million for operations in 2006-07 and this was followed by ? 600 million in the 2006 Pre-Budget Report. Most recently, the 2007 Budget allocated a further 400million for 2007-08. Thus, to date, the total amount allocated to the Special Reserve is ? 7. 44 billion. The Special Reserve is not only set aside for costs in Iraq, but also for â€Å"the UK’s other international obligations†[7]. However, nowhere in the public domain has the Treasury published how much of the Special Reserve has been spent, nor how much of it has been spent on Iraq. Table 2 (please see pdf file above). , which gives a breakdown of the spending of the Special Reserve, was obtained through a Freedom of Information request solicited by the Iraq Analysis Group. Of the ? 6. 44bn set aside at various times to the Special reserve by March 2006, at least ? 6. 3bn had been allocated to departments, almost the total amount possible. About ? 4. 4bn of the Reserve had been spent by the Ministry of Defence in Iraq[8] between 2002 and 2006, with at least an additional ? 156 million allocated to the Foreign and Commonwealth Office and the Department for International Development. Furthermore, the forecasted outturn for the financial year 2005-06 is larger than that of 2004-05, suggesting that costs in Iraq are still far from settling down to something approaching the spending in Afghanistan. How Much is ? 4. 4 Billion? The ? 4. 4 billion already allocated to operations in Iraq has been raised through the pre-existing tax structure, borrowing and other government revenue and consequently there exists some trade-off between the additional defence spending and other public spending options. ?3. 2 billion spent on education, for example, would be sufficient to fund the recruitment and retention of over 10,300 new teachers for ten years. In health, it would allow the building of around 44 new hospitals. The ? 6. 44 billion Special Reserve represents the entire annual budget of the Department of International Development and would allow a five-fold increase in bilateral aid to Africa[9]. According to UNICEF estimates, ? 5 billion would fund two years of full immunization for every child in the developing world[10]. Oil Prices Any sort of uncertainty in the Middle East is serious because of the possible effects on oil prices and, in turn, the possible effects on the economies of the rest of the world. Iraq is particularly significant because its proven oil reserves are 112 billion barrels or about 10 per cent of the worlds total. Iraqs reserves are second only to its neighbour Saudi Arabia. Further exploration is likely to significantly increase Iraqs proven reserves. Iraqs oil is also said to be very attractive because it is easy to recover and so production costs are among the lowest in the world. (2) Iraqs sustainable production is around 2. 8 2. 9 million barrels per day, with a net export potential of around 2. 3 2. 5 million barrels per day. Those figures compare with total world oil production of 68 million barrels per day and the Organisation of Petroleum Exporting Countries (OPEC) production of 29 million barrels per day, or 42 per cent of the total. (3) The US is by far the biggest consumer of petroleum consuming 19. 6 million barrels per day of which net imports are 10. 9 million barrels per day. (4) Iraqs production potential is limited by aging infrastructure in poor repair. UN sanctions prevent the importation of spare parts and other necessary equipment. The volume of Iraqi exports permitted under UN sanctions (the oil-for-food program) is much lower at around 1. 6 million barrels per day; however, some additional oil is smuggled out of Iraq. According to the US Energy Information Agency some oil experts think that Iraqs oil production could double in the next few years provided sufficient investment were to be made and the UN sanctions lifted. (5) The prospect of continued and possibly expanded Iraqi production is behind some of the optimistic scenarios examined below. Also important have been statements by the OPEC to the effect that they would be able to cover any reduction in supplies from Iraq, despite suggestions that OPEC is producing near full capacity. (6) Any increase in non-OPEC production would also help moderate oil prices. In the longer term supplies from non-traditional sources, including Central Asian members of the former Soviet Union, could put downward pressure on prices. Oil prices have increased throughout most of 2002 and into 2003 from about US$20 per barrel in mid 2002 to around US$35 per barrel in early March 2003. There have been many commentators willing to suggest that oil prices may peak at much higher values. Bad case scenarios have been published that estimate oil prices increasing to US$75 per barrel by George Perry from the Brookings Institute and US$80 per barrel by the Centre for Strategic and International Studies. (7) While such figures tend to be reported by the press, it needs to be kept in mind that these are only worst case scenarios. Large sudden price increases cannot be ruled out. However, it is important to note that war with Iraq has been widely anticipated and we would expect that the effects of war would be anticipated in the markets and already be reflected in prices. Against that, some observers suggest that a quick war without damage to Iraqs oil wells would eliminate the war premium and reduce prices to figures around US$20 per barrel. (8) Effects of Higher Oil Prices Oil price increases act like a tax on fuel that is collected by oil producers and transfers income from users to producers. It increases the burdens on users, and when the users are businesses, it increases the costs that they are likely to pass on to the consumer. The oil tax also involves major changes to international trade and investment flows. The 1970s oil price increases were associated with major disruptions to economic activity sparking international recession as well as inflation. The term stagflation was introduced to refer to the unusual combination of both higher inflation and unemployment that began during this period. The International Monetary Fund (IMF) has done some work on the specific effects of higher world oil prices. Modelling the effect of a permanent US$5 per barrel increase in oil prices the IMF finds that world GDP would fall by 0. 2 per cent in year one and 0. 3 per cent in years two and three. There would be a roughly equal transfer of GDP (also around 0. 2 per cent) to oil producing countries from oil importing countries with additional transfers within countries. Other Macroeconomic Implications Oil prices will play a large part in the eventual outcomes of the war with Iraq. However, there are more than just the direct effects of oil prices involved. The world economy is going through a period of volatility and uncertainty partly associated with geo-political concerns. All economic commentators refer to the present uncertainty and its effects on both investors and consumers. In the case of Iraq, political uncertainty also has a direct impact on the rest of the world through oil prices. A common view seems to be that the uncertainty relates to the immediate future and that, once the Iraq problem is out of the way, everything will be clearer. For example, in his testimony to the US Congress, the chair of the Federal Reserve Board, Alan Greenspan, anticipates the removal of the Iraq-related uncertainties'(17) that seem to be complicating the present view of the world economy. Another observer has said: The common, hopeful view on Wall Street is that a short, decisive victory in a war with Iraq wouldnt cost much and would lead to a big stock market rally, which would be good for investor and consumer confidence. (18) While a war would obviously put pressure on the budget balance that in turn can have other implications for the economy as a whole. War is not necessarily bad for the economy. It is now well known that the rearmament of the major powers in the late 1930s and 1940s, before and during the Second World War, was associated with the end of the great depression of the 1930s. As one student of this period puts it: The Second World War brought the era of the Depression to a sudden and dramatic end, as the entire resources of the major countries were absorbed in the military struggle. With the outbreak of hostilities, full employment was fairly swiftly achieved everywhere. (19) Obviously there is nothing on the horizon that looks anything like the Second World War, but there is likely to be some fiscal stimulus nevertheless. The 200203 budget papers note that fiscal stimulus generally has the effect of supporting the aggregate level of economic activity. As the 200203 budget papers put it: Expansionary fiscal policy settings in 200001 and 200102 helped Australia maintain solid economic growth relative to other developed countries during a period of weakness in the international economy A large part of the stimulus in 200102 was unavoidable given the impact of high priority defence and domestic security expenditure. This outcome is appropriate given Australias recent economic circumstances and international developments. (20) To the extent that there are under-utilised resources in Australia, government spending can lead to an increase economic activity and employment. However, the fiscal stimulus must be put in the context of the damaging effects of the uncertainty facing the world economy. The uncertainty surrounding the war is undoubtably having a negative effect on investment and consumption decisions all around the world. Given that the fiscal stimulus is rather small even in the US, it might be expected that the uncertainty will more than offset any stimulus. However, a short quick war would remove uncertainty allowing the fiscal stimulus to dominate. In this context there are some forecasts that suggest the outcome could be positive for the UK economy, for example. Oxford Economic Forecasting made such a forecast showing modest GDP increases of around 0. 2 per cent in the UK as a result of the stimulus from military spending. (21) Newsletter Economic Scenarios has attempted to model the economic effects of a hypothetical Iraqi war on the Australian economy. (22) The outcome of the Economic Scenarios modelling is that, over the period 200310, Australia would experience a loss in GDP equivalent to US$18 billion in the short war scenario (war is over in 2003 and rebuilding takes two years) or US$69 billion in the long war scenario (conflict and occupation of five years and five years of rebuilding). Using exchange rates at close of business 26 February 2003 puts the loss in GDP at $30 billion (short) to $114 billion (long). These results suggest a very significant adverse impact on Australia. However, those results reflect the nature of the economic model and some possibly extreme assumptions, including that: * Australian government defence outlays increase by one per cent of GDP in 2003 and either 1 or 0. 5 per cent for the next few years depending on the scenario * oil prices jump immediately to US$80 per barrel and then either slowly return to near normal or return quickly depending on the scenario, and * uncertainty has an effect equivalent to investors demanding 5 per cent in greater returns on their investments causing investment outlays to fall. That premium on investments fades away either slowly or quickly depending on the scenario. The first assumption is just a guess based on Congressional Budget Office estimates that the US will spend something of that order and that small countries involved will likely spend similar amounts as a share of GDP. One percent of Australias GDP is around $7 billion. Access Economics puts the likely costs of war at around $700 million for a three month engagementa tenth of the Economic Scenarios assumption. Access Economics also estimates that over $200 million has already been spent in pre-deployment. (23) Even then, reallocating resources within the Defence Department could absorb a good deal of the $700 million. The Economic Scenarios study received headlines because it purported to show a massive cost to the Australian economy as a result of war in Iraq. However, those models are only as good as the assumptions on which they rest, and if the assumptions are extreme then results will be unrealistic.

Accuracy of Rectal Water Contrast Transvaginal Ultrasound

Accuracy of Rectal Water Contrast Transvaginal Ultrasound Abstract Objectives:  To compare the accuracy of rectal water contrast transvaginal ultrasound (RWC-TVS) and double-contrast barium enema (DCBE) in assessing the presence and extent of bowel endometriosis. Methods:  This prospective study included 198 patients of reproductive age with suspicion of bowel endometriosis. RWC-TVS and DCBE were performed before operative laparoscopy by two groups of physicians specialized in endometriosis, each blinded to the results of the other groups. Findings of RWC-TVS and DCBE were compared with histological results. The severity of pain experienced during RWC-TVS and DCBE was measured by a 10 cm visual analog scale. Results:  In total, 110 of the 198 women had bowel endometriosis nodules confirmed at laparoscopy and histopathology patients. For the diagnosis of bowel endometriosis DCBE and RWC-TVS had a sensitivity of 96.4% and 88.2%, specificity of 100% and 97.3%, positive predictive value of 100% and 98.0%, negative predictive value of 98.0% and 88.0% and accuracy of 98.0% and 92.4% respectively. DCBE was associated with more intense pain than was RWC-TVS. Conclusions: RWC-TVS and DCBE have similar accuracy in the diagnosis of bowel endometriosis, but patients tolerate RWC-TVS better than they do DCBE. Keywords: double-contrast barium enema; rectal water contrast transvaginal ultrasound; bowel endometriosis; diagnosis Introduction Bowel endometriosis affects between 4-37% of patients with endometriosis1. Intestinal endometriosis lesions may have variable size2. Small endometriosis nodules located on the serosal surface of the bowel rarely cause symptoms and, therefore, do not require treatment2. Larger endometriosis nodules infiltrate the bowel wall and may cause various gastrointestinal complaints such as dyschezia, diarrhea, constipation, abdominal bloating and intestinal cramping1, 3. These symptoms may mimic irritable bowel syndrome. Symptoms caused by bowel endometriosis are nonspecific, often resulting in misdiagnosis or delay in diagnosis4. Physical examination may suggest the presence of rectovaginal endometriosis; however, it has poor accuracy in diagnosing rectosigmoid nodules5, 6. Until recently, the ultrasonic diagnosis of endometriosis was limited to patients with ovarian endometriomas and other imaging techniques were used for the assessment of bowel endometriosis including rectal endoscopic ultrasound, transvaginal ultrasound (TVS), double-contrast barium enema (DCBE), magnetic resonance imaging (MRI), multidetector computerized tomography enema (MDCT-e) and virtual colonoscopy7-10. TVS is a reliable non-invasive method to assess the presence and the extent of bowel endometriosis11. Injecting saline through a catheter into the rectum during TVS (rectal-water contrast TVS, RWC-TVS) may facilitate the identification of rectosigmoid nodules, the assessment of the depth of infiltration of endometriosis in the intestinal wall and estimation of the degree of stenosis of the bowel lumen. However, no previous study compared the accuracy of DCBE and RWC-TVS in the diagnosis of rectosigmoid endometriosis4, 12, 13. A preoperative diagnosis of the presence and extent of bowel endometriosis is necessary to determine whether surgery is required and to plan the surgical procedure with the colorectal surgeon14. Knowing before surgery the size and number of intestinal endometriosis nodules, the depth of infiltration of the nodules in the intestinal wall and the degree of stenosis of the bowel lumen allows determining whether surgery is required and may allow the surgeons to choose between nodulectomy and bowel segmental resection15, 16. In addition, determining before surgery the extent of bowel endometriosis allows the surgeon to inform the patient about the potential benefits and complications of the surgical procedure that will be performed. In fact, postoperative complications and evolution of digestive symptoms after surgery may differ between patients undergoing nodulectomy and those undergoing segmental resection, with a higher incidence of bladder-voiding dysfunction and postoperative constipation in patients undergoing the latter procedure. In this study, we compared the accuracy of DCBE and RWC-TVS in assessing the presence and extent of bowel endometriosis. Methods Study population This prospective study was performed between May 2012 and Aug 2016. Participants were recruited among patients of reproductive age scheduled for laparoscopy with strong suspicion of intestinal endometriosis based on symptoms and clinical examination. During this period, the imaging workup required that both DCBE and RWC-TVS were performed in patients with suspicion of bowel endometriosis. Institutional review board approval was obtained before initiating the study. Patients participating in the study signed a written consent form. Inclusion criteria for the study were: reproductive age and suspicion of deep pelvic endometriosis; presence of gastrointestinal symptoms that might be caused by bowel endometriosis; and desire to undergo complete surgical excision of the endometriosis. Patients were excluded from the study if they had previous bilateral ovariectomy; previous barium radiological examination or radiological diagnosis of bowel endometriosis; previous colorectal surgery; previ ous episodes suggestive of intolerance to iodinated contrast medium; renal or hepatic failure; refusal to undergo DCBE and psychiatric disorders. Symptoms were systematically investigated during the study period and they were recorded in a database. The presence of dysmenorrheal, deep dyspareunia, non-menstrual pelvic pain and dyschezia was investigated and the intensity of their symptoms was assessed in all patients on a 10 cm visual analog scale (VAS), on which the left extremity represented absence of pain and the right extremity indicated maximum intensity of pain. The presence of the following gastrointestinal symptoms was assessed: diarrhea-predominant irritable bowel syndrome; constipation-predominant irritable bowel syndrome; passage of mucus in the stools; rectal bleeding; intestinal cramping; and abdominal bloating. A symptom analogue scale questionnaire was used to estimate the severity of each gastrointestinal symptom. DCBE and RWC-TVS results were compared with surgical and pathologic findings. The radiologists performing DCBE and the gynecologists performing TVS were each blinded to the others results. They were blinded to the clinical data and knew only that the presence of intestinal endometriosis was suspected. All patients underwent laparoscopy within 1 month from the completion of the diagnostic investigations. Intestinal endometriosis was defined as the disease infiltrating at least the muscularis propria. Endometriosis foci located on the bowel serosa were considered peritoneal and not bowel endometriosis. The present study determined the accuracy of DCBE and RWC-TVS in assessing the presence of bowel endometriosis, estimating the size and the number of bowel endometriosis nodules and determining the presence of peritoneal endometriosis infiltrating only the intestinal serosa. Rectal water contrast transvaginal ultrasound technique Two physicians performed all the examinations according to a standardized procedure. RWC-TVS was performed by using a Voluson E6 machine connected to a transvaginal transducer. After the transducer had been introduced into the vagina, an assistant inserted a 6-mm flexible catheter through the anus into the rectal lumen up to a 15 cm distance from the anus. A gel infused with lidocaine was used to facilitate passage of the catheter. A 50 mL syringe was connected to the catheter and warm sterile saline solution was injected inside the rectum and the sigmoid under ultrasonic control. The amount of saline solution needed to show the rectosigmoid ranged between 100 and 350 mL, depending on the distensibility of the intestinal wall. One hundred milliliters of saline solution were continuously and slowly infused at the beginning of the procedure; the rest of the solution was infused when requested by the ultrasound. During ultrasound, when saline solution was not being infused, backflow through the catheter was prevented by placing a Klemmer forceps on the catheter. There w as no significant leakage of saline solution into the space between the catheter and the anus. Images were obtained before, during and after saline injection. Bowel endometriosis appears ultrasonographically as a nodular, solid, hypoechoic lesion, adjacent to and/or penetrating the intestinal wall. Hyperechoic foci may sometimes be present within the lesion. Intestinal distension allows defining the limits of the intestinal nodules and in particular the various layers of the rectal wall in order to estimate the depth of infiltration. The intestinal serosa is hyperechoic; the two layers of the muscularis propria appear as hypoechoic strips separated by a fine hyperechoic line; the submucosa is hyperechoic; the muscularis mucosa is hypoechoic and the interface between the lumen and the mucosal layer is hyperechoic. Rectal endometriosis infiltration is demonstrated by the fact that the hypoechoic nodule penetrates the intestinal wall and, in general, it thickens the muscularis mucosa. Two different ultrasonic signs are commonly used to describe this condition. Double-contrast barium enema All DCBE procedures were carried out using a motorized tilting table for fluoroscopic and radiological examination. In preparation, patients maintained a low-residue diet for 1 day prior to the examination in order to keep the enteric content fluid. The examination was performed after intramuscular administration of 20 mg (1 ampoule) Scopolamine in order to induce colonic hypotonia. The presence of bowel endometriosis was diagnosed on DCBE when the bowel lumen was narrowed at any level from the sigmoid to the anus in association with crenulation of the mucosa and/or speculation of contour. Tolerability of the examinations Immediately after each examination patients were asked to rate the discomfort encountered during DCBE and RWC-TVS by means of a 10 cm visual analogue scale (VAS), mild pain was defined as a VAS score of 5. Surgery and histological evaluation The surgeons examined the reports and the images of DCBE and RWC-TVS prior to laparoscopy. Although the diagnosis of recto-sigmoid endometriosis and its treatment were based on laparoscopic findings. All surgical procedures were performed laparoscope by a team of gynecological and colorectal surgeons with extensive experience in the treatment of pelvic and bowel endometriosis. In all cases, after adequate adhesiolysis, the sigmoid colon and rectum were systematically examined to verify the presence of endometriosis lesions. Bowel endometriosis lesions were removed by intestinal resection in cases of a single lesion >3 cm in diameter, a single lesion infiltrating at least 50% of the circumference of the intestinal wall or three or more lesions infiltrating the muscular layer. In all other cases of bowel endometriosis partial- or full-thickness disk resection was performed. Intestinal lesions infiltrating only the serosal layer of the bowel wall were excised by shaving. All visible les ions suspected to be endometriosis were excised and sent for histological examination in agreement with our clinical protocol. The surgical specimens were evaluated by histological; the depth of infiltration of the endometriosis nodules in the bowel wall was assessed. In cases of nodulectomy the specimens were macroscopically oriented along the intestinal wall (from the serosa towards the mucosa) and cut into macro sections of 2 mm thickness. From each macrosection tissue blocks of 1.5 cm length were obtained in variable numbers according to the size of the lesion, and from each tissue block a 5  µm section was obtained for microscopically evaluation. In cases of bowel resection the specimen was opened longitudinally through its entire length and 2mm longitudinal bands of bowel wall, reaching the two resection margins and passing through all macroscopically visible lesions, were cut. These bands were sampled in tissue blocks and 5  µm sections were obtained for microscopic evaluation. Statistical analysis Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both DCBE and RWC-TVS. The diagnostic value of each test was also assessed using positive likelihood ratio (LR+) and negative likelihood ratio (LR-). Efficacy parameters were calculated with 95% confidence intervals (CIs). McNemars test with the Yates continuity correction was used to compare the accuracy of DCBE and RWC-TVS in the diagnosis of intestinal endometriosis. McNemars test was used to compare the number of patients in which the number of rectosigmoid nodules was correctly identified by DCBE and RWC-TVS. The accuracy of the measurement of nodule size by imaging techniques was estimated by subtracting the size of the nodule as measured by the techniques from the size of the nodules measured at histology. The nonparametric Mann-Whitney test was used to compare the intensity of pain experienced by patients during DCBE and RWC-TVS, the chi-square test was used to co mpare the type of pain (mild, moderate or severe) and Spearmans rank correlation coefficient was used to determine whether there was a correlation between the intensity of pain experienced by patients during the two techniques. Data were analyzed using the SPSS software. p Results Study population A total of 198 patients were enrolled in the study and all underwent surgery were included in this study (Figure 1). The main demographic characteristics of the study are demonstrated in Table 1. The intensity of pain and gastrointestinal symptoms are presented in Table 2. Surgery and histology demonstrated that 110 patients (55.6%) had bowel endometriosis nodules. The endometriosis lesions infiltrating the intestinal serosa in 28 patients. The remaining 82 patients had only pelvic endometriosis with no evidence of intestinal lesions. The largest intestinal endometriosis nodule was found locate on the sigmoid colon in 53 patients, on the rectum in 30 patients, at the rectosigmoid junction in 20 patients, on the ileum in 5 patients and on the caecum in 2 patients. The endometriosis lesions infiltrating only the intestinal serosa were located on the sigmoid colon in 15 cases, on the rectum in 5cases and at the rectosigmoid junction in 3 cases. The mean ( ±SD) length of the resected bowel segment was 12.2  ± 3.6 cm. The diagnosis of endometriosis was confirmed in all the excised nodules by histological exam. Furthermore, it demonstrated that the deepest endometriosis nodule infiltrated the muscularis propria in 62 patients (56.4 %), the submucosa in 3 1 patients (28.2%) and the mucosa in 17 patients (15.5%). Accuracy of RWC-TVS and DCBE in the diagnosis of bowel endometriosis The accuracy, sensitivity, specificity, PPV, NPV, LR+ and LR- of DCBE and RWC-TVS in the diagnosis of bowel endometriosis are described in Table 3. DCBE identified 106 of 110 patients with bowel endometriosis (96.4%). In 4 patients endometriosis nodules infiltrating the muscularis propria of the rectum were not identified, which were excised by partial-thickness nodulectomy. RWC-TVS identified 97 of 110 patients with intestinal endometriosis (88.2%). RWC-TVS did not identify 4 ileal lesions, 2 cecal lesions, 4 sigmoid nodules and 3 rectal nodules infiltrating the muscularis propria. Furthermore, we identified 4 of these patients had large bilateral endometriosis ovarian cysts, which may have hampered the identification of intestinal nodules. There was 2 false positive on RWC-TVS-a rectovaginal endometriosis nodule that was judged to infiltrate the muscularis of the rectum. Surgery confirmed the presence of the rectovaginal nodule but did not reveal infiltration of the rectal muscularis. The sensitivity, specificity, PPV, NPV, LR+, LR- and accuracy of the two techniques in the diagnosis of intestinal endometriosis were shown in Table 3. McNemars test showed that there was no significant difference in the accuracy of the two techniques in the diagnosis of bowel endometriosis (P=0.109). Histology examination demonstrated that endometriosis infiltrated the submucosa or mucosa of the rectosigmoid colon in 53 patients. DCBE correctly identified the depth of infiltration in 27 of these patients (50.9%), while RWC-TVS correctly identified the depth of infiltration in 20 of them (37.7%) (P=0.126). All the other nodules that were seen to infiltrate the submucosa or mucosa at histology were judged to reach only the muscularis at DCBE and RWC-TVS. Both techniques had no cases of false-positive diagnosis of submucosal or mucosal infiltration. Both DCBE and RWC-TVS underestimated the size of the endometriosis nodules; however, the underestimation was greater for RWC-TVS than for DCBE (Table 4). In addition, in both imaging techniques the underestimation was greater for nodules with diameter≠¥30 mm. Tolerability of DCBE and RWC-TVS DCBE was safely performed in all the patients. During both the examinations all patients tolerated intestinal distension and in no patient was it necessary to interrupt the procedure. However, the intensity of pain experienced during DCBE was significantly higher than the intensity of pain experienced during RWC-TVS (Table 5). A positive correlation was observed between the intensity of pain experienced by the patients during the two examinations (Spearman correlation coefficient=0.575; p Discussion To the best of our knowledge, this is the first study demonstrated that DCBE and RWC-TVS have similar accuracy in the diagnosis of bowel endometriosis. Both RWC-TVS and DCBE underestimated the size of bowel endometriosis nodules, but under estimation was greater for RWC-TVS than for DCBE, particularly when the nodules had largest diameter ≠¥ 30 mm (Table 4). The choice of the ultrasonic technique is often based on the experience of the ultrasonographers rather than on evidence of superiority of one technique compared to the others. In fact, TVS must be performed by highly skilled, it has been recently estimated that the learning curve for an accurate diagnosis of deep pelvic endometriosis by TVS requires performing about 40 cases17. Therefore, it may be difficult to achieve such experience for ultrasonographers working in small hospital. The main advantage of DCBE could be that, with a retrograde distension of the entire colon, this technique may provide a complete overview of t he whole colon18. In the current study, the distension was targeted to the rectosigmoid because the aim of the study was the comparison with RWC-TVS and endometriosis lesions of the right colon are beyond the field of view of a transvaginal approach. Furthermore, we did not compare the accuracy of RWC-TVS with TVS alone, which was the objective of a previous study. RWC-TVS was chosen for the comparison with DCBE because of the personal experience of the authors and of the common criterion of bowel distension with fluid. The usefulness of this technique was subsequently confirmed by the same authors in larger series. Furthermore, other authors confirmed that intestinal distension and opacification using ultrasound gel helps to visualize rectosigmoid endometriosis nodules19, 20. Previous studies have suggested that TVS could reliably diagnose rectosigmoid endometriosis. The sensitivity of TVS for detecting rectosigmoid endometriosis is between 91 and 98%, the specificity between 97 and 100%, the PPV between 97 and 100% and the NPV between 87 and 98%21-24. Recently, RWC-TVS has been developed to facilitate identification of intestinal lesions in patients with rectovaginal endometriosis and to determine the depth of infiltration of endometriosis in the intestinal wall25. TVS has been extensively used in patients with bowel endometriosis; while only little data is available on the use of DCBE in these patients. This study demonstrated that DCBE and RWC-TVS have similar accuracy in the diagnosis of bowel endometriosis. Both techniques precisely estimated the length of the rectosigmoid nodules, but DCBE was more precise than RWC-TVS in assessing the distance between the endometriosis nodule and the anal verge9. Obviously, the extensive experience of the radiologi st and the gynecologist in DCBE and RWCTVS, respectively, may have influenced the accuracy of these techniques in diagnosing bowel endometriosis24, 26. The findings may be explained by the fact that when performing imaging techniques, particularly RWC-TVS, it might be difficult to choose the plane in which the irregular endometriosis nodule has the largest diameter. However, the difference between the estimated size of the nodule and the largest diameter as measured on histopathology was quite small and, in most cases, it seems unlikely that this difference would affect the choice of nodulectomy or bowel resection as treatment27. Importantly, patients tolerated RWC-TVS better than they did DCBE. These findings are in line with those of previous studies demonstrating the accuracy of TVS in the diagnosis of bowel endometriosis and comparing TVS with other techniques such as MRI and rectal endoscopic ultrasound11, 28-30. The potential benefits of introducing aqueous contrast medium into the rectum during TVS have been questioned. TVS is an operator-dependent procedure and it is possible that the differences observed in the accuracy of this technique are determined by the experience of the ultrasonographer carrying out the procedure31. However, adding intestinal aqueous contrast to TVS may facilitate the identification of rectosigmoid lesions. Other techniques have been proposed for improving the accuracy of TVS in the detection of deep endometriosis, such as sonovaginography or the use of large quantities of ultrasound transmission gel (12 mL) in the probe cover32. Up to now, no study has established whether any one of these ultrasonic techniques is superior to the others in the diagnosis of deep endometriosis. TVS should be considered the first-line investigation in patients with deep endometriosis, and allows the diagnosis of intestinal lesions24. Other investigations such as RWC-TVS, MDCT-e, MRI, rectal endoscopic ultrasound and DCBE may be used to determine the characteristics of intestinal endometriosis, such as the size and number of nodules, the depth of infiltration of the nodules in the intestinal wall and the degree of stenosis of the bowel lumen33-35. RWC-TVS has several advantages over the other techniques. It is less expensive than MDCT-e and MRI and the equipment required to perform the procedure is commonly available to gynecologists, who are usually involved in the management of patients with endometriosis. A recent study has shown that RWC-TVS allows estimation of the degree of stenosis of the intestinal lumen caused by endometriosis36. Unfortunately, this parameter was not examined in the current study- the major limitation of our investigation. Theoretically, RWC-TVS may also allow determination of the extent of the disease along the longitudinal intestinal axis. Obviously, RWC-TVS cannot determine the presence of intestinal nodules located proximally to the sigmoid because these lesions are beyond the field of TVS. This study had several limitations. First, the experience of the ultrasonographer in RWC-TVS may influence the accuracy of these techniques in diagnosing bowel endometriosis. Second, the surgeons were aware of the findings of DCBE and RWC-TVS. Although in an ideal prospective study the surgeons should be blinded to the findings of the preoperative investigations, this theoretical study design appears unethical in clinical practice because diagnostic imaging may facilitate the identification of intestinal endometriosis nodules during surgery. Furthermore, the knowledge of the findings of the preoperative investigations may only help the surgeons in identifying endometriosis nodules that were actually present. Third, RWC-TVS and DCBE did not estimate the percentage of the circumference of the intestinal wall infiltrated by endometriosis, a criterion used to choose between nodulectomy and bowel resection. Therefore, patients scheduled for nodulectomy on the basis of DCBE and RWC-TVS fin dings should be informed that bowel resection might be required for the complete excision of intestinal endometriosis. Future studies should examine whether DCBE and RWC-TVS can reliably estimate what percentage of intestinal circumference is infiltrated by endometriosis. DCBE may still have a role in the diagnostic workup of patients with suspected bowel endometriosis. When TVS or RWC-TVS demonstrates large intestinal nodules infiltrating the bowel muscularis, bowel resection can probably be performed without further investigation unless the surgeon wants to exclude intestinal lesions located proximally to the sigmoid. In contrast, when ultrasound demonstrates a single bowel nodule that may be excised by nodulectomy, DCBE should be used to exclude the presence of other intestinal nodules and, thus, to adequately plan the surgical procedure with the colorectal surgeon and the patient. Conclusions This study showed that RWC-TVS is a reliable technique for determining the presence and extent of bowel endometriosis and that it has an accuracy similar to that of DCBE. However, RWC-TVS may sometimes underestimate the presence of multiple bowel nodules and can be performed easily in an ambulatory setting and it is better tolerated by patients. It may be hypothesized to combine TVS and DCBE to achieve a complete preoperative assessment of the bowel in order to offer to the patients an adequate counseling and the most appropriate one-step surgical treatment.