Introduced Species in United States Coastal Waters

This pdf document commissioned by the Pew Ocean Commission describes the problem of invasive species along the United States coastline. The document provides information regarding how bioinvasions occur, the number of invasive species introduced, the effects of bioinvasions, prevention, reduction and control of marine bioinvasions and recommendations for action against invasive species invasion. The pdf also provides a glossary of bioinvasion terms. Educational levels: Graduate or professional, Undergraduate lower division, Undergraduate upper division

Product Variety and Demand Uncertainty

We show that demand uncertainty leads to vertical product differentiation even when consumers are homogeneous. When a firm anticipates that its inventory or capacity may not be fully utilized, product variety can reduce its expected costs of excess capacity. When the firm offers a continuum of product varieties, the highest quality product has the highest profit margins but the lowest percentage margin, while the lowest quality product has the highest percentage margin but the lowest absolute margin. We derive these results in both a monopoly model and a variety of different competitive models. We conclude with a discussion of empirical predictions together with a brief discussion of supporting evidence available from marketing studies.

Religious belief and social control, with special reference to patterns of stability and change in classical Athens and ancient Egypt

The social sciences are vitiated by the perennial problem of social order. Questions concerning the nature and possible determinants of social formations are often intriguing and necessarily conjectural, but the problem of how such structures are then kept in being constitutes one of the fundamental issues of sociology. Social order connotes social stability, and this is necessarily difficult to study in the modern world of dissolving and crystallizing social patterns. This thesis, therefore, sets out to examine the problem of order in the context of complex pre-industrial society which, whilst not completely., static, exhibits more clearly and comprehensively the persistent features of institutional life. The discussion rests upon a typification of Static and Dynamic societies. The Static society is characterised by retrospective orientations and eunomic (good order) stability, and the Dynamic society by qualified prospective orientations and anomic innovation. It hypotheses that these factors, in turn, can be related to the nature, form and implementation of the belief-systems concerned. The term 'pre-industrial society' is not a vague classification which can be stamped on an undifferentiated past. Certainly the ancient world' witnessed a great variety of systems. The main body, of this discussion is involved with a comparative analysis of two such systems, Egypt and Classical Athens, which may be typified as Static and Dynamic societies. Key institutional areas are-examined and related to the main themes of religion and social control

Industry Analysis on Domestic Petroleum Transportation Industry

Thesis (M.B.A.)--Boston Universit

Boundary-Layer Transition on Hollow Cylinders in Supersonic Free Flight as Affected by Mach Number and a Screwthread Type of Surface Roughness

The effects of Mach number and surface-roughness variation on boundary-layer transition were studied using fin-stabilized hollow-tube models in free flight. The tests were conducted over the Mach number range from 2.8 to 7 at a nominally constant unit Reynolds number of 3 million per inch, and with heat transfer to the model surface. A screwthread type of distributed two-dimensional roughness was used. Nominal thread heights varied from 100 microinches to 2100 microinches. Transition Reynolds number was found to increase with increasing Mach number at a rate depending simultaneously on Mach number and roughness height. The laminar boundary layer was found to tolerate increasing amounts of roughness as Mach number increased. For a given Mach number an optimum roughness height was found which gave a maximum laminar run greater than was obtained with a smooth surface

The Asian red seaweed Grateloupia turuturu (Rhodophyta) invades the Gulf of Maine

We report the invasion of the Gulf of Maine, in the northwest Atlantic Ocean, by the largest red seaweed in the world, the Asian Grateloupia turuturu. First detected in 1994 in Narragansett Bay, Rhode Island, south of Cape Cod, this alga had expanded its range in the following years only over to Long Island and into Long Island Sound. In July 2007 we found Grateloupia in the Cape Cod Canal and as far north (east) as Boston, Massachusetts, establishing its presence in the Gulf of Maine. Grateloupia can be invasive and may be capable of disrupting low intertidal and shallow subtidal seaweeds. The plant\u27s broad physiological tolerances suggest that it will be able to expand possibly as far north as the Bay of Fundy. We predict its continued spread in North America and around the world, noting that its arrival in the major international port of Boston may now launch G. turuturu on to new global shipping corridors

Product variety and demand uncertainty

We demonstrate that demand uncertainty alone can lead to equilibrium product variety. We consider a simple environment in which when demand is certain, a social planner, a competitive market, and a monopolist would all offer a single product, but when demand is uncertain, a social planner, a competitive market, and a monopolist will all offer vertically differentiated products. When a firm anticipates that its inventory or capacity may not be fully utilized, increasing product variety is efficient because it reduces the expected costs of excess capacity. We find that when the firm offers a continuum of product varieties, the highest quality product has the highest profit margins but the lowest percentage margin, while the lowest quality product has the highest percentage margin but the lowest absolute margin. We derive these results in both a monopoly model and a variety of different competitive models. We conclude with a discussion of empirical predictions together with a brief discussion of supporting evidence available from marketing studies