The vegetative development of juvenile and mature Dumontia contorta (S. G. Gmelin) Ruprecht is characterized. New patterns of red algal thallus development are described. Dumontia contorta has an isomorphic life history with similarly branched erect gametophytes and tetrasporophytes. Erect plants are winter‐spring annuals that develop from a perennating crustose stage. Vegetative development of D. contorta includes both multiaxial and uniaxial systems. Juvenile thalli emerging from crustose bases are unbranched and entirely multiaxial; the main axis of a mature thallus is also multiaxial with the number of axial filaments decreasing acropetally as branches are initiated. Most lateral branches are uniaxial and do not rebranch. Thus, mature D. contorta is characterized by multiaxiality in the lower main axis and by uniaxiality in its branches and in the tip region of the main axis. Our study corrects a number of inaccuracies in the literature and reinterprets the pattern of thallus development in D. contorta in relation to stages of its vegetative growth. Development of D. contorta is compared with that of other higher red algae. Our results suggest an evolutionary derivation of D. contorta from the uniaxial, unbranched D. simplex.
Resource Equivalency Analysis (“REA”) is often used to “right-size” (scale) or calibrate compensatory restoration projects implemented as part of Natural Resource Damage Assessments (“NRDAs”) conducted pursuant to the Oil Pollution Act of 1990 (“OPA”). The basic premise underlying REA is that, if a spill results in the loss of individual members of a population, the public can be compensated via a restoration project which creates individuals that otherwise would not exist. This is because the ecological services provided by a population are proportional to the number of individuals in the population. For example, one could compensate the public for spill-related mortality among shrimp by creating wetland terraces which, the literature suggests, would increase the number of shrimp in the population. REA answers the question, “How many wetland terraces need to be created?” Implicit in the REA construct is the dynamic nature of the population projections. Even with density dependence, population levels fluctuate according to both biological and anthropogenic factors that combine to influence survival, reproductive and growth rates. Thus, if NRDA practitioners are to reliably identify compensatory restoration requirements using REA, it is necessary to: characterize baseline demographic rates; develop a model that uses those baseline demographic rates to project future population levels; and identify the mechanisms that cause post-spill rates to change relative to baseline expectations. One factor that can cause post-spill demographic rates to vary is a spill-related change in human behavior. For example, if a spill-related fishing closure results in the cancelation of 15,000 recreational shrimping trips, shrimp mortality due to fishing will decrease. In this paper we use prior OPA NRDA cases to: review the historical treatment of spill-related closures in REA models used by both DOI/USFWS and NOAA; and illustrate that the REA practitioners’ approach to these spill-related changes in human behavior can (and should) change the NRDA liability construct, particularly with respect to species which are commercially and recreationally harvested.
The purpose of this article is to assess the adequacy of disclosure requirements for environmental information. Beginning with listing rules and market disclosures, it then analyses disclosure from the viewpoint of accountancy standards, corporate governance and requirements for pension fund trustees, and finally, voluntary standards of disclosure and de facto or ad hoc disclosures occurring in different sectors of industry. It is argued that it is beyond doubt that environmental information is an important source of financial information. As such, it should be disclosed in a uniform manner and on a regular basis because of its potential impact on investment decision-making, company value and the viability and profitability of businesses. It follows that there should be an end to the uncertainty concerning the question of the "materiality" of environmental information, its disclosure and an acceptance of the need to disclose it. The failure to require specific disclosure of environmental information, and the general failure by corporations to accept the materiality of environmental information in light of other legislative developments in the field of investor protection, is viewed as a major weakness. Providing such important information to investors ought to be an obligation on listed companies. To overcome this significant weakness, specific and if possible, uniform disclosure rules for environmental information must be adopted generally.
Thanks to its precision, its reproducibility and its stability, Electron Microprobe is a well suited technique for accurately analyze nearly all chemical element to concentration level down to few 10's ppm with a spatial resolution of about 1 µm, which is relevant to microstructures in a wide variety of materials and mineral specimens.With the development of the Schottky emitter and its implementation as electron source in Electron Microprobe, small features are commonly analyzed own to sub-micrometer scale. Thanks to the high brightness of the Schottky emitter, fine focused electron beam can be achieved with both high and stable beam currents even low accelerating voltages (≤10 keV).Since X-rays are generated from a much larger diameter than the diameter of the incident electron beam, it is necessary to optimize the two interdependent parameters, accelerating voltage and beam diameter, in order to take full advantage of the FEG electron source for X-ray analysis. The electron beam diameter increases with decreasing the electron beam energy as shown on figure 1. The interaction volume -within which scattered electrons generate X-rays -decreases with the electron energy as shown on Monte Carlo simulation run with the program CASINO [1] on figure 2 . Thus a small beam diameter is not always synonym of a small interaction volume and optimized conditions are obtained when the analytical spatial resolution is primarily limited to the diameter of the X-ray emission volume in a specific material.The ability to accurately quantify precipitate phases on the micrometer and sub-micrometer scale when working at low beam energy with high spatial resolution will be illustrated in examples as Dunite, igneous rock locally enriched in Platinum acquired on the CAMECA SXFiveFE. The analytical resolution determined from X-ray maps will be presented.
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