Eigenvectors of block circulant and alternating circulant matrices

The eigenvectors and eigenvalues of block circulant matrices had been found for real symmetric matrices with symmetric submatrices, and for block circulant matrices with circulant submatrices. The eigenvectors are now found for general block circulant matrices, including the Jordan Canonical Form for defective eigenvectors. That analysis is applied to Stephen J. Watson’s alternating circulant matrices, which reduce to block circulant matrices with square submatrices of order 2

The lender of last resort in the european single financial market

The paper examines challenges in effectively implementing the lender-of-last-resort function in the EU single financial market. Briefly highlighted are features of the EU financial landscape that could increase EU systemic financial risk. Briefly described are the complexities of the EU’s financial-stability architecture for preventing and resolving financial problems, including lender-of-last-resort operations. The paper examines how the lender-of-last-resort function might materialize during a systemic financial disturbance affecting more than one EU Member State. The paper identifies challenges and possible ways of enhancing the effectiveness of the existing architecture

Sonar behaviour in non-terrestrial ocean exploration

A goal for a future Europan payload is to determine the extent of the postulated sea, aspects of acoustic remote sensing are discussed with a view to operating a sonar in such an subsurface ocean

Portfolio Diversification, Leverage, and Financial Contagion

This paper studies the extent to which basic principles of portfolio diversification explain "contagious selling" of financial assets when there are purely local shocks (e.g., a financial crisis in one country). The paper demonstrates that elementary portfolio theory offers key insights into "contagion." Most important, portfolio diversification and leverage are sufficient to explain why an investor will find it optimal to significantly reduce all risky asset positions when an adverse shock impacts just one asset. This result does not depend on margin calls: it applies to portfolios and institutions that rely on borrowed funds. The paper also shows that Value-at-Risk portfolio management rules do not have significantly different consequences for portfolio rebalancing than a variety of other rules. Copyright 2000, International Monetary Fund

Cost effectiveness analysis of laparoscopic hysterectomy compared with standard hysterectomy: results from a randomised trial

Objective: To assess the cost effectiveness of laparoscopic hysterectomy compared with conventional hysterectomy (abdominal or vaginal). Design: Cost effectiveness analysis based on two parallel trials: laparoscopic (n = 324) compared with vaginal hysterectomy (n = 163); and laparoscopic (n = 573) compared with abdominal hysterectomy (n = 286). Participants: 1346 women requiring a hysterectomy for reasons other than malignancy. Main outcome measure: One year costs estimated from NHS perspective. Health outcomes expressed in terms of QALYs based on women's responses to the EQ-5D at baseline and at three points during up to 52 weeks' follow up. Results: Laparoscopic hysterectomy cost an average of pound401 ($708; C571) more (95$471789; E380 437). The, probability that laparoscopic hysterectomy is cost effective was below 50% for a large range of values of willingness to pay for an additional QALY. Laparoscopic hysterectomy cost an average of pound186 ($328; E265) more than abdominal hysterectomy, although 95$46 893; E37 813). If the NHS is willing to pay pound30 0 00 for an additional QALY, the probability that laparoscopic hysterectomy is cost effective is 56%. Conclusions: Laparoscopic hysterectomy is not cost effective relative to vaginal hysterectomy. Its cost effectiveness relative to the abdominal procedure is finely balanced