33 research outputs found
Salt marsh nitrogen analysis : fertilization and the allocation of biological productivity
A five compartment schematic model of the flow of nitrogen
through Great Sippewissett Marsh is presented. Flows are described
in terms of annual inputs, outputs and intercompartmental transfers
of nitrogen. The nitrogen in all forms occurring in the
marsh is considered, though dissolved organic nitrogen is disaggregated
from the total flow.
A computer aided input - output analysis is performed on
the model to assess the degree to which nitrogen inputs to the
marsh surface are linked to nitrogen outputs in the form of net
growth in marsh shellfish. In this way the effects of both
direct and indirect flows linking the two compartments involved
are considered. The analysis is done to assess the likelihood
that a large scale application of fertilizer to the marsh surface
will signjficantly enhance shellfish growth in marsh tidal
creeks. While no definitive answer to this question can be
given, it is argued that the present level of understanding of
the marsh nitrogen cycle does not support an expectation that
shellfish growth will be enhanced. This argument is supported
by a comparative analysis which shows a strong likelihood that
Spartina growth is enhanced by fertilization, an effect which
has already been observed.Prepared with funds from the Pew Memorial Trust
and by the Department of Commerce, NOAA Office
of Sea Grant under Grant #04-8- M01-149 and the
Institution's Marine Policy and Ocean Management
Program
The importance of human dimensions research in managing harmful algal blooms
Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 8 (2010): 75–83, doi:10.1890/070181.Harmful algal blooms (HABs) are natural freshwater and marine hazards that impose substantial adverse impacts on the human use of coastal and marine resources. The socioeconomic and health impacts of HABs can be considerable, thereby making a case for “human dimensions” research to support HAB response. Human dimensions research is multidisciplinary, integrating social science, humanities, and other fields with natural science to enhance resource management by addressing human causes, consequences, and responses to coastal environmental problems. Case studies reported here illustrate the importance of human dimensions research. Incorporating such research into the scientific agenda – as well as into management decisions of public agencies concerned with natural resource management, environmental protection, and public health and welfare – requires the development of both strategic guidance and institutional capacity. The recent development of a multi-agency research strategy for HAB response and a strategic plan for human dimensions research represent two important steps in this direction.This paper was developed with partial support from
NOAA’s National Centers for Coastal and Ocean Science
Genome and Transcriptome of Clostridium phytofermentans, Catalyst for the Direct Conversion of Plant Feedstocks to Fuels
International audienceClostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of the present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C. phytofermentans is reflected in a diversity of genes encoding ATP-binding cassette sugar transporters and glycoside hydrolases, many of which may have been acquired through horizontal gene transfer. These genes are frequently organized as operons that may be controlled individually by the many transcriptional regulators identified in the genome. Preferential ethanol production may be due to high levels of expression of multiple ethanol dehydrogenases and additional pathways maximizing ethanol yield. The genome also encodes three different proteinaceous bacterial microcompartments with the capacity to compartmentalize pathways that divert fermentation intermediates to various products. These characteristics make C. phytofermentans an attractive resource for improving the efficiency and speed of biomass conversion to biofuels
A Procedural Evaluation of an Analytic-Deliberative Process: The Columbia River Comprehensive Impact Assessment
The U.S. Department of Energy\u27s Columbia River Comprehensive Impact Assessment (CRCIA) was an ambitious attempt to direct its cleanup of the Hanford Nuclear Reservation toward the most significant risks to the Columbia River resulting from past plutonium production. DOE\u27s approach was uncommonly open, including tribal, regulatory agency, and other Hanford interest group representatives on the board that was to develop the assessment approach. The CRCIA process had attributes of the ``analytic-deliberative\u27\u27 process for risk assessment recommended by the National Research Council. Nevertheless, differences between the DOE and other participants over what was meant by the term ``comprehensive\u27\u27 in the group\u27s charge, coupled with differing perceptions of the likely effectiveness of remediation efforts in reducing risks, were never resolved. The CRCIA effort became increasingly fragmented and the role its products were to play in influencing future clean-up decisions increasingly ambiguous. A procedural evaluation of the CRCIA process, based on Thomas Webler\u27s procedural normative model of public participation, reveals numerous instances in which theoretical-normative discourse disconnects occurred. These had negative implications for both the basic procedural dimensions of Webler\u27s model-fairness and competence. Tribal and other interest group representatives lacked the technical resources necessary to make or challenge what philosopher Jurgens Habermas terms cognitive validity claims, while DOE and its contractors did not challenge normative claims made by tribal representatives. The results are cautionary for implementation of the analytic-deliberative process. They highlight the importance of bringing rigor to the evaluation of the quality of the deliberation component of risk characterization via the analytic-deliberative process, as well as to the analytic component
Container terminal productivity: a perspective.
National Oceanic and Atmospheric Administration, Rockville, Md.Mode of access: Internet