Particulate organic matter transport in the lower Colorado river,South-Western USA

The lower Colorado River from Laughlin, Nevada, to the border with Mexico is one of the most regulated rivers in North America. An analysis of particulate organic matter (POM) transport through the system was made to determine POM concentrations, composition and point of origin, as well as to determine the effect dams had on this transport. Particulate organic matter concentrations generally increased from upstream to downstream, and were dominated by very fine organic detritus (< 25μm size fraction). Reservoirs released more POM than they received during spring and summer, but less during autumn and winter. Reservoirs recycled POM, taking in organic detritus and discharging small limnoplankton. Backwater complexes functioned as filters during storm events, trapping coarse material and releasing fine material. Agricultural drains made only minor contributions of POM, but provided important nutrients for in-channel production of POM. Water diversions forced POM off-channel, whereas sluicing operations reduced inorganic loads in the canals. Despite the presence of six mainstem dams, the lower reaches support a diverse assemblage of detritivorous fishes, similar to that found in the lowermost reaches of natural, unregulated rivers. The food base for this fishery stems from autochthonous production of POM.     

Directly measuring early exercise premiums using American and European S&P 500 Index options

The Chicago Board Options Exchange concurrently listed European‐style and American‐style options on the Standard and Poor's 500 Index from April 2, 1986 through June 20, 1986. This unique time period allows for a direct measurement of the early exercise premium in American‐style index options. In this study, using ask quotes, we find average early exercise premiums ranging from 5.04 to 5.90% for calls, and from 7.97 to 10.86% for puts. Additionally, we are able to depict a potentially useful functional form of the early exercise premium. As in previous studies, we find some instances of negative early exercise premiums. However, a trading simulation shows that traders must be able to trade within the bid–ask spread to profit from these apparent arbitrage opportunities. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:287–313, 2003     

THE LAST MILE: AN EXAMINATION OF EFFECTS OF ONLINE RETAIL DELIVERY STRATEGIES ON CONSUMERS

The Internet has increased the level of importance of the end‐consumer market to transportation carriers. In two between subject experiments, carrier disclosure on retail merchant websites is examined as a strategic differentiation strategy. Predictions are offered concerning effects of carrier disclosure strategies on product delivery‐related expectations, consumer attitudes, and intentions to purchase a product online. Results from Study 1 reveal significant differences between disclosure and nondisclosure of the carrier for numerous product delivery‐related variables, as well as many differences between the six carriers examined in this first study. Study 2 extends these findings by showing that providing consumers with a choice of carrier leads to increased levels of satisfaction with the online experience and greater willingness to buy, relative to nondisclosure and disclosure strategies.     

LOGISTICS OUTSOURCING RELATIONSHIPS: CUSTOMER PERSPECTIVES

This study attempts to infuse relationship marketing theory into the study of logistics outsourcing relationships. In particular, the study demonstrates that not all of the partnerships between customers and providers of third‐party logistics services are the same in terms of their level of development. The existence of distinct levels of partnership established previously in the logistics literature is partially supported and a relationship between level of partnership development and the customer perceptions of key relationship marketing elements and outcomes is established. While exploratory in nature, these findings suggest there are benefits for the increased costs of developing closer partnerships.     

Distribution and Fate of Escherichia coli in Lake Michigan Following Contamination with Urban Stormwater and Combined Sewer Overflows

Escherichia coli distribution and persistence in nearshore Lake Michigan were assessed following heavy rains and sanitary sewer overflow (SSO) and combined sewer overflow (CSO) events over a 5-year period, including an 18-day period following 25.4 cm of rainfall in which intensive studies were conducted following multiple CSO and SSO events. E. coli levels in the Milwaukee estuary and harbor following SSO and CSO events ranged from 10⁴ to nearly 10⁵ CFU/100 mL, which were significantly higher (p ≤ 0.05) than levels following rainfall alone. Sites outside of the breakwall but within the contamination plume (e.g., within 2 km of the harbor) were an order of magnitude lower. Locations 2–5 km from the harbor ranged from below detection limits, of < 1 to 5 CFU/100 mL. E. coli levels corrected for dilution based on specific conductivity measurements were lower than what would be expected for loss due to dilution alone, suggesting a combination of die-off and dilution, were responsible for the rapid disappearance of these organisms outside of the harbor. E. coli and fecal coliforms measured concurrently demonstrated that fecal coliforms could be recovered longer than E. coli in the open waters of the lake. E. coli isolated directly from sewage treatment plant influent were found to have a marked increase in antibiotic resistance traits for ten antibiotics commonly used in the human population compared with isolates from two animal sources of fecal pollution. However, E. coli obtained from sewage impacted water (n = 2,513) and from stormwater impacted water (n = 1,465) collected the previous year when there were no sewage overflows, were found to have no significant difference (p < 0.05) in the frequency of resistance when comparing the two conditions. E. coli survival characteristics and population dynamics are most likely influenced by multiple factors in complex systems such as the watershed/estuarine/lake environments of the Great Lakes.     

Corporate moral agency: A case from literature

I analyze a well-known and moving passage from John Steinbeck's novelThe Grapes of Wrath. This passage provides an excellent illustration of one of the central questions about corporate moral agency: Is corporate moral agency anything over and above the agency of individual human beings? The passage in question is a debate about whether or not the actions of a particular company are anything over and above the actions of individual human beings.     

Nea presidential address, 1991: Sixteenth-century European expansion and the economic decline of Africa (in honor of Walter Rodney)

Prior to the sixteenth century, the Indian Ocean trading network was one of the wealthiest commercial regions in the world. It included states of East Africa, the Arabian peninsula, the Indian subcontinent, Southeast Asia, China and Japan. By circumnavigating Africa, Portugal was the first European nation to gain access to the region. Through the exercise of naval superiority, blockading of strategic shipping lanes, imposition of duties and expulsion of Swahili and Muslim merchants, Portugal exercised a mercantile monopoly which ultimately led to the region’s rapid economic decline. Using rare historical documents from Po rtugal and Africa, this study traces the effects of Portuguese expansion on the economies of East Africa and trade in the Indian Ocean.     

The Robustness of the APT to Alternative Estimators

We test the robustness of the APT to two alternative estimation procedures: the Fama and MacBeth (1973) two-step methodology; and the one-step procedure due to Burmeister and McElroy (1988). We find that the APT is indeed sensitive to the chosen estimator and assumptions about the factor structure of stock returns. We believe that our findings have implications for the estimation of asset pricing models in general.