Are stock prices too volatile to be justified by the dividend discount model?

This study investigates excess stock price volatility using the variance bound framework of LeRoy and Porter [The present-value relation: tests based on implied variance bounds, Econometrica 49 (1981) 555-574] and of Shiller [Do stock prices move too much to be justified by subsequent changes in dividends? Am. Econ. Rev. 71 (1981) 421-436.]. The conditional variance bound relationship is examined using cross-sectional data simulated from the general equilibrium asset pricing model of Brock [Asset prices in a production economy, in: J.J. McCall (Ed.), The Economics of Information and Uncertainty, University of Chicago Press, Chicago (for N.B.E.R.), 1982]. Results show that the conditional variance bounds hold, hence, our hypothesis of the validity of the dividend discount model cannot be rejected. Moreover, in our setting, markets are efficient and stock prices are neither affected by herd psychology nor by the outcome of noise trading by naive investors; thus, we are able to control for market efficiency. Consequently, we show that one cannot infer any conclusions about market efficiency from the unconditional variance bounds tests. © 2006 Elsevier B.V. All rights reserved

Length-weight relationships of 28 fish species caught from demersal trawl survey in the Middle Black Sea, Turkey

This study provides updated the length-weight relationships and Fulton's condition factor of 28 fish species belonging to 23 families from the Black Sea. Samples were collected along the depths between 0-100 meters by demersal trawl surveys conducted seasonally from May 2017 to September 2019. A total of 83,885 specimens were collected. The length-weight relationships and Fulton's condition factor, minimum, maximum and mean lengths, total weights, descriptive statistics, and growth type were provided for all the species. The results indicate that LWR parameters of b varied from 2.2039 to 3.737 and Fulton's condition factor varied between 0.004 and 1.18. These findings could be useful for monitoring and management of sustainable fisheries and habitat health

Management and Outcome of Cardiac and Endovascular Cystic Echinococcosis

Cardiac and vascular involvement are infrequent in classical cystic echinococcosis (CE), but when they occur they tend to present earlier and are associated with complications that may be life threatening. Cardiovascular CE usually requires complex surgery, so in low-income countries the outcome is frequently fatal. This case series describes the characteristics of cardiovascular CE in patients diagnosed and treated at a Tropical Medicine & Clinical Parasitology Center in Spain. A retrospective case series of 11 patients with cardiac and/or endovascular CE, followed-up over a period of 15 years (1995–2009) is reported. The main clinical manifestations included thoracic pain or dyspnea, although 2 patients were asymptomatic. The clinical picture and complications vary according to cyst location. Isolated cardiac CE may be cured after surgery, while endovascular extracardiac involvement is associated with severe chronic complications. CE should be included in the differential diagnosis of cardiovascular disease in patients from endemic areas. CE is a neglected disease and further studies are necessary in order to make more definite management recommendations for this rare and severe form of the disease. The authors propose a general approach based on cyst location: exclusively cardiac, endovascular or both

Aorto left atrial fistula with bicuspid aortic valve and coronary artery origin anomaly

WOS: A1997WM32600063PubMed ID: 9066423Published reports of aorto-left atrial fistula are very rare. We report a 20-year-old man who had an aorto-left atrial fistula with bicuspid aortic valve and coronary artery origin anomaly. Because acquired etiologic factors were not detected, we believe that the lesions were structural defects of congenital origin. (C) 1997 by The Society of Thoracic Surgeons