INTRODUCTION McKittrick-Wheelock syndrome describes the condition of extreme electrolyte and fluid depletion caused by large distal colorectal tumours, usually the benign villous adenoma. Patients generally present critically unwell with severe hyponatraemia, hypokalaemia and/or acute kidney injury. METHODS A structured literature review was undertaken to discover what is known about this condition, which is almost universally described as rare. Important features of the syndrome were identified, including common presenting symptoms, blood results, tumour location and size. FINDINGS Our literature search identified 257 cases reported across all languages. The most remarkable features were the long duration of symptoms (median 24 months) and the significant electrolyte derangements (median sodium of 122mmol/l and median potassium of 2.7mmol/l at initial presentation). Five key recommendations are made to improve diagnosis, including aggressive fluid resuscitation to match rectal losses and surgical intervention on the index admission. The advantages and disadvantages of different treatment options are discussed, including minimally invasive alternatives to traditional resectional surgery. CONCLUSIONS McKittrick-Wheelock syndrome describes a normally benign condition that can cause patients to become critically unwell and so it behoves all clinicians to be aware of it. By publishing recommendations based on a comprehensive literature review, we aim to improve diagnosis and management of this life threatening condition.

Being inspired by the work of Imkeller et al., who first developed a measured-valued version of Malliavin calculus to study the enlargement of filtration by an 'exogenous' random variable on the Wiener space, in this article we consider the enlargement of filtration on the Poisson space. We construct a measure-valued Malliavin calculus on the Poisson space with the Malliavin type calculus defined by Mensi and Privault. Without resorting to the traditional Jacod's condition nor its local version, the measure-valued Poisson Malliavin calculus can be applied to compute the 'information drift'. Our result applies for a general L 2-integrable 'exogenous' random variable, while previous works require a more restrictive Malliavin differentiability. Finally, we illustrate a concrete application of our results with an example fromMensi and Privault.

In 2011 the local clinical commissioning group introduced a policy restricting funding for elective hernia repairs. Anecdotally, it was felt that this resulted in an increased number of emergency hernia repairs in our trust. Our primary objective was to assess whether this was actually the case. Our secondary objective was to quantify the risks of non-elective hernia repair.

This paper provides a test for the equality of multiple Sharpe ratios. First we extend the multivariate Sharpe ratio statistic of Leung and Wong for the case when excess returns are independently and identically distributed. We then provide a test that holds under the much more general assumption that the excess returns are stationary and ergodic, making use of the generalized method of moments and heteroscedasticity and autocorrelation consistent estimation of covariance matrixes. We repeat Leung and Wong's testing for equality of the Sharpe ratios of 18 iShares using our new tests and conclude that the hypothesis of equality cannot be rejected at the 1% level.

Purpose– The purpose of this study is to verify whether the trading strategy can beat the “buy-and-hold” strategy for the securitized real estate indices of six Asian economies: Hong Kong, China, Japan, Taiwan, Thailand and Malaysia.Design/methodology/approach– This paper constructs a trading strategy from the Shiryaev-Zhou index and tests the strategy on the securitized real estate indices of six emerging Asian economies: Hong Kong, China, Japan, Taiwan, Thailand and Malaysia. The authors compare the resulting profits from using the trading strategy with the resulting profits from using the “buy-and-hold” strategy. The authors consider three cases: no transaction costs, 0.1 percent transaction costs, and 0.2 percent transaction costs.Findings– The results show that the trading strategy the authors constructed generally outperforms the “buy-and-hold” strategy even in the presence of transaction costs. In particular, the authors have a new finding as follows: Thailand and Malaysia's securitized real estate indices fell drastically during the period of observation. However, applying the trading strategy to these two securitized real estate indices can still earn a profit.Practical implications– The trading strategy is particularly useful in protecting investors from huge loss in adverse market conditions. The results can be applied to the field of finance/investment that investors can construct a trading strategy similar to the authors to earn more profits.Originality/value– This study will consider cases where both buying and selling costs exist, so the scenario is more like stock transactions in real-life equity markets. Furthermore, in this paper, for each securitized real estate index, the authors plot a graph to show the holding and non-holding periods under the trading strategy. This would help the authors explain the resulting profit under the trading strategy. This kind of graphical analysis was neglected by Hui and Yam.

This paper examines twenty-seven international real estate securities indices from twenty countries and regions for calendar effects. Two methodologies are employed. The first is the standard approach which detects statistically significant anomalies via linear regression of returns. The second, new to the real estate securities literature, tests for economically significant effects through two tests specifically designed to compare multiple forecasts to a benchmark, White’s (Econometrica, 1097–1126, 2000) Reality Check and Hansen’s (J Bus Econ Stat 23(4):365–380, 2005) Superior Predictive Ability test. The standard approach tells us that while some effects have disappeared over time, statistically significant calendar anomalies persist. However, the tests of White and Hansen strongly suggest that they are not economically significant and thus should not be the basis of an investor’s trading strategy nor be considered as a challenge to market efficiency, as has been claimed previously.

This paper provides sufficient conditions for the enlargement of filtrations on Poisson space, making use of a calculus of variations whose gradient is with respect to jump times. It is found that the construction of a measure-valued Malliavin calculus in Imkeller at al. (2001) directly applies analogously to the Poisson space with the Malliavin type calculus defined in Mensi and Privault (2003). Some new, explicit calculations of enlargement of filtrations are provided, making use of the translation operator defined in Nualart and Vives (1990).

Recent results in optimal stopping theory have shown that a 'bang-bang' (buy or sell immediately) style of trading strategy is in some sense optimal provided the asset's price dynamics follow certain familiar stochastic processes. This paper construc

We consider a family of discrete multiperiod multinomial market models F n , each of which contains n − 1 stocks and one bond. All the securities are allowed to be risky and we assume that the number of states in each period is finite. We let the securities’ prices follow probability distributions that reflect the traders’ view of the market. Under mild restrictions on the probability structure of F n , we show that the probability that a market, chosen at random from F n , is complete tends to one as n approaches infinity.