Does the weight of riparian trees destabilize riverbanks?

In contrast to the generally accepted stabilizing effects of riparian vegetation, the surcharge of trees on riverbanks has been widely implicated as a source of bank instability. Fieldwork conducted along the Latrobe River in Victoria, Australia shows that the bank‐destabilizing effects of surcharge, due to silver wattle (Acacia dealbata), are minimal. Field observations indicate that it is unlikely that the weight of silver wattles growing on an otherwise stable bank section will directly cause mass failure. Observations of deep‐seated failures and silver wattle stands on the Latrobe River indicate that where average‐sized slump‐blocks support an average number of average‐sized silver wattles, the trees represent only 4.1% of the total saturated slump mass. Infinite slope stability analysis indicates a threshold of around 48° where banks become prone to shallow‐planar slide failures as they steepen. Where bank sections are inherently unstable and prone to shallow‐planar slide failure, the additional weight of the trees may contribute to overall instability. However, manipulation of other stability parameters within reasonable constraints negates the effect of surcharge so it is not possible to demonstrate conclusively a destabilizing influence of silver wattles. Copyright © 2000 John Wiley & Sons, Ltd.     

Vladimirskaya hydroelectric pumped storage power plant as the first pilot power project of the 21st century

The authors describe the Vladimirskaya hydroelectric pumped storage power plant that is currently being designed as the pilot Russian power project for the 21st century.Translated from Gidrotekhnicheskoe Stroitelstvo, No. 8, August 2004, pp. 15 – 20.     

A note on diversification and the reduction of dispersion

The purpose of this paper is to note that the question of optimal diversification cannot be answered simply by determining the average variability of equally allocated investment. Empirical results are presented which show that it is possible to obtain the same level of average variation with far greater average portfolio returns and fewer securities in the portfolio by using an alternative allocation scheme.     

Capital Structure Theory and REIT Security Offerings

In this paper, we examine the stock price reactions to announcements of new security offerings by Real Estate Investment Trusts (REITs). REITs offer a unique setting in which to study these events because they do not pay taxes at the firm level. Theory suggests that the net tax gain to corporate borrowing is unambiguously negative for a REIT. Contrary to some recent studies, however, we find a positive stock price reaction to debt offerings, while the negative equity-issuance effect is preserved. Further empirical evidence lends support to signalling as the explanation for the positive significant debt-issuance effect.     

Nonsynchronous Security Trading and Market Index Autocorrelation

The theoretical portfolio autocorrelation due solely to nonsynchronous trading is estimated from a derived model. This estimated level is found to be substantially less than that observed empirically. The theoretical and empirical relationship between portfolio size and autocorrelation also is investigated. The results of this study suggest that other price-adjustment delay factors in addition to nonsynchronous trading cause the high autocorrelations present in daily returns on stock index portfolios.     

The Exploitation of Inside Information at the Wall Street Journal: A Test of Strong Form Efficiency

The study examines if tradings on stocks based on the inside information about the “Heard on the Street” column of the Wall Street Journal could generate abnormal returns. We found significant abnormal returns on days t =?1 and t= 0 (publication date) for the stocks related to insider trading. For a comparable control group of noninsider traded stocks, the abnormal returns were not significant on day t=?1 but were significant on day t= 0. The abnormal returns for the insider trade group on days t=?1 and t= 0 were greater than the returns for the control group. The results indicate that the inside information was the cause for the differences.