Hearing on Non-point Source Pollution: The Impacts of Agriculture on Water Quality

Congressional testimony by Robert W. Howarth, before the U.S. House of Representatives subcommittee on Water Resources & the Environment - The Impact of Agriculture on Water Quality. April 19, 2007

Sovereign Immunity - An Argument Pro

The Ohio Doctrine of Sovereign Immunity vis-a-vis the United States Constitution, fourteenth amendment, will hereinafter be considered. Before delving into the constitutional realities, however, the substance of this narrow discussion should be placed in perspective with the multifarious civil actions arising out of the Kent State tragedy, May 4, 1970

Influential publications in ecological economics revisited

We revisit the analysis of Costanza et al. (2004, Ecological Economics) of influential publications in ecological economics to discover what has changed a decade on. We examine which sources have been influential on the field of ecological economics in the past decade, which articles in the journal Ecological Economics have had the most influence on the field and on the rest of science, and on which areas of science the journal is having the most in- fluence.We find that the field has matured over this period, with articles published in the journal having a greater influence than before, an increase in citation links to environmental studies journals, a reduction in citation links to mainstream economics journals, and possibly a shift in themes to a more applied and empirical direction.Copyright Information: © 2016 Elsevier B.V. http://www.sherpa.ac.uk/romeo/issn/0921-8009/..."Authors pre-print on any website, including arXiv and RePEC" from SHERPA/RoMEO site (as at 3/02/16)

Simplifying and improving the extraction of nitrate from freshwater for stable isotope analyses

Determining the isotopic composition of nitrate (NO3_) in water can prove useful to identify NO3_ sources and to understand its dynamics in aquatic systems. Among the procedures available, the ‘ionexchange resin method’ involves extracting NO3_ from freshwater and converting it into solid silver nitrate (AgNO3), which is then analysed for 15N/14N and 18O/16O ratios. This study describes a simplified methodology where water was not pre-treated to remove dissolved organic carbon (DOC) or barium cations (added to precipitate O-bearing contaminants), which suited samples with high NO3_ ($400 mM or 25 mg L_1 NO3_) and low DOC (typically <417 mM of C or 5 mg L_1 C) levels. % N analysis revealed that a few AgNO3 samples were of low purity (compared with expected % N of 8.2), highlighting the necessity to introduce quality control/quality assurance procedures for silver nitrate prepared from field water samples. Recommendations are then made to monitor % N together with % O (expected at 28.6, i.e. 3.5 fold % N) in AgNO3 in order to better assess the type and gravity of the contamination as well as to identify potentially unreliable data

Controls of benthic nitrogen fixation and primary production from nutrient enrichment of oligotrophic, Arctic lakes

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosystems 16 (2013): 1550-1564, doi:10.1007/s10021-013-9701-0.We examined controls of benthic dinitrogen (N2) fixation and primary production in oligotrophic lakes in Arctic Alaska, Toolik Field Station (Arctic Long-Term Ecological Research Site). Primary production in many oligotrophic lakes is limited by nitrogen (N), and benthic processes are important for whole-lake function. Oligotrophic lakes are increasingly susceptible to low-level, non-point source nutrient inputs, yet the effects on benthic processes are not well understood. This study examines the results from a whole-lake fertilization experiment in which N and P were added at a relatively low level (4 times natural loading) in Redfield ratio to a shallow (3 m) and a deep (20 m) oligotrophic lake. The two lakes showed similar responses to fertilization: benthic primary production and respiration (each 50–150 mg C m−2 day−1) remained the same, and benthic N2 fixation declined by a factor of three- to fourfold by the second year of treatment (from ~0.35 to 0.1 mg N m−2 day−1). This showed that the response of benthic N2 fixation was de-coupled from the nutrient limitation status of benthic primary producers and raised questions about the mechanisms, which were examined in separate laboratory experiments. Bioassay experiments in intact cores also showed no response of benthic primary production to added N and P, but contrasted with the whole-lake experiment in that N2 fixation did not respond to added N, either alone or in conjunction with P. This inconsistency was likely a result of nitrogenase activity of existing N2 fixers during the relative short duration (9 days) of the bioassay experiment. N2 fixation showed a positive saturating response when light was increased in the laboratory, but was not statistically related to ambient light level in the field, leading us to conclude that light limitation of the benthos from increasing water-column production was not important. Thus, increased N availability in the sediments through direct uptake likely caused a reduction in N2 fixation. These results show the capacity of the benthos in oligotrophic systems to buffer the whole-system response to nutrient addition by the apparent ability for significant nutrient uptake and the rapid decline in N2 fixation in response to added nutrients. Reduced benthic N2 fixation may be an early indicator of a eutrophication response of lakes which precedes the transition from benthic to water-column-dominated systems.This project was supported by NSF-OPP 9732281, NSF-DEB 9810222, NSF-DEB 0423385, and by a Doctoral Dissertation Improvement Grant NSF-DEB 0206173. Additional funding was provided by the Small Grants Program through the NSF-IGERT Program in Biogeochemistry and Environmental Change at Cornell University

The role of sulfur in salt marsh metabolism

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1979The rate of sulfate reduction in stands of dwarf Spartina alterniflora in the Great Sippewissett Salt Marsh is approximately 75 moles S04 m2 year-1. This is the highest rate reported for any natural ecosystem. Sulfate reduction is the most important form of respiration in the marsh and results in the annual consumption of 1800 g C m-2, approximately equivalent to net primary production. Sulfate reduction rates in the peat are high for at least three reasons: 1) the below-ground production of Spartina alterniflora provides a large, annual input of organic substrates over a depth of some 20 cm, 2) sulfate is rapidly resupplied to the peat in infiltrating tidal waters, so low sulfate concentrations never limit the rate of sulfate reduction, and 3) sulfide concentrations remain below toxic levels. The stable mineral pyrite is a major end-product of sulfate reduction in salt marsh peat while iron mono-sulfides are not. This is unlike most anoxic marine sediments and apparently results because iron mono-sulfides are undersaturated. The iron mono-sulfides are undersaturated in part because of the relatively low concentration of total soluble sulfides and in part because of the fairly low pH of the peat. Both of these conditions probably result from the activity of the Spartina roots. If the incorporation of 35S into pyrite were not measured, the S3504 reduction measurements would greatly underestimate the true rate of sulfate reduction. Pyrite acts largely as a temporary store of reduced. sulfur. The pyrite concentration of the peat undergoes seasonal changes. On an annual basis, the reduced sulfur which results from sulfate reduction is either re-oxidized to sulfate within the peat or is exported, much of it as thiosulfate or a similar intermediately reduced compound. Most of the energy which is originally in organic matters is stored in reduced sulfur compounds when the organic matter is respired by sulfate reducing bacteria. Consequently, the export of reduced sulfur compounds from the peat represents an energy export. The export of energy as reduced inorganic sulfur compounds is probably larger than the net above-ground production by Spartina. This is an important vector for moving some of the energy trapped by the below-ground production of Spartina to zones where it is available for coastal food webs.Later support was from the National Science Foundation Grant DEB 78-03557

The tyranny of a kilogram : should we untie rather than cut the Gordian knot?

Thesis (MPhil) -- University of Stellenbosch, 1999.ENGLISH ABSTRACT: The number of babies requiring neonatal intensive care exceeds the facilities available. The assignment questions the perceived shortage of resources and investigates methods of resource allocation. The first chapter addresses the development of technology and reflects briefly on the romance between medicine and technology. The second chapter addresses the issue of prognosis of the small preterm neonate and reflects on how these data are derived and the assumptions that are often made based on prognostic data. Chapter three concentrates on how outcomes discussed in the second chapter may be quantified. Individual utility quantification plays a role in decision making for the individual neonate, while comparative utility quantification addresses some of the issues concerned with the macroallocation of resources. This leads into chapter four that addresses macroallocation and challenges some of the assumptions that resource allocation is based upon. Are resources scarce? Are there financial constraints? What is the role of medicine in health? Will redistribution of wealth necessarily improve the health of the population? Who should. make decisions for individual sick neonates regarding neonatal intensive care is addressed in the next chapter. The tension between sanctity-of-life and quality-of-life ideologies, created by life sustaining technology has been legally and ethically settled in favour of the patient's right to self-determination, based on the principle of respect for patient autonomy. It will however be argued that the traditional four principles cannot be utilised as the neonate is at best pre-autonomous. Moral obligations towards the neonate are dependent on the beneficence and non-maleficence obligations of the parents and the caregivers. Both these principles are prima facie and may have to be tempered by distributive justice. Plato's absolutist thinking and Descartes mathematician's perspective, have influenced medicine's romance with certainty. If knowledge and certainty are necessary for decision· making and it is shown that absolute certainty is elusive, should we be nihilistic about decision making in neonatal intensive care? Chapter 6 critically assesses three approaches to decision making in the presence of prognostic uncertainty. In contemporary medicine there is a constant tension between the traditional commitment to the patient on the one hand and the awareness that resources are finite on the other, this tension is an unfortunate reality of medicine. To constrain the growth of medical expenditure, doctors are now asked to serve simultaneously as society's agent of cost containment and as the patient's agent for maximum health. There is increasing pressure on doctors to serve two masters, society and the patient. Acting on behalf of society as a gatekeeper, while for the patient the doctor is expected to act as advocate. Chapter seven investigates both gate-keeping and advocacy and attempts to answer the question whether doctors can and indeed should try to serve two masters Simultaneously? The final chapter brings together the threads of the various extended arguments and attempts to give solutions to some of the conundrums.AFRIKAANSE OPSOMMING: Die hoeveelheid babas wat neonatale intensiewe sorg benodig oorskry die beskikbare fasiliteite. Die taak bevraagteken die waameming van 'n tekort aan hulpbronne en ondersoek dus metodes van hulpbronallokasie. Die eerste hoofstuk bespreek die ontwikkeling van tegnologie en reflekteer kortliks oor die romanse tussen medisyne en tegnologie. Die tweede hoofstuk handel oor die uitslag van die prognose van die klein voortydse neonaat en reflekteer hoe die data afgelei word en die veronderstellings wat dikwels gemaak word, gebaseer op prognostiese data. Hoofstuk drie konsentreer op die bespreekte uitkomste van hoofstuk twee en hoe dit bepaal kan word. Nuttige individuele bepaling speel 'n rol tydens besluitneming ten opsigte van die individuele neonaat, andersyds, vergelykende nuttige bepaling spreek sommige van die punte ten opsigte van die makro-allokasie van hulpbronne aan. Laasgenoemde gee inleiding tot hoofstuk vier, wat makro-allokasie aanspreek en sommige van die aannames waarop hulpbronallokasie gebaseer is uitdaag. Is hulpbronne skaars? Is daar finansiele beperking? Wat is die rol van medisyne in gesondheid? Sal herverspreiding van rykdom noodwendig die gesondheid van die populasie verbeter? Wie verantwoordelik is vir besluitneming ten opsigte van die siek neonaat in intensiewe sorg word in die volgende hoofstuk bespreek. Die spanning tussen onskendbaarheid-van-lewe en kwaliteitvan-lewe ideologie, moontlik gemaak met behulp van lewens-onderhoudende tegnologie is wettig sowel as eties vasgestel ten gunste van die pasient se reg tot selfbeskikking, gebaseer op die beginsel van respek vir die pasient se selfbeskikking. Dit sal egter betwis word dat die tradisionele vier beginsels nie aangevoer kan word nie omdat die neonaat pre-outonomies is. Morele verpligtinge teenoor die neonaat is afhanklik van die weldadigheid en onskadelike verpligtinge van die ouers en versorgers. Seide hierdie beginsels is prima facie en sal moontlik deur verdelende reg getemper moet word. Plato se absolutistiese denke en Descartes se wiskundige perspektief het die medisyne se romantiek met sekerheid beinvloed. Indien kennis en sekerheid nodig is vir besluitneming en dit is bewys dat absolute sekerheid misleidend is, moet ons nihilisties wees oor besluitneming in neonatale intensiewe sorg? In Hoofstuk 6 word die drie benaderings tot besluitneming in die teenwoordigheid van prognostiese onsekerheid krities beraam. In die hedendaagse medisyne is daar 'n konstante spanning tussen die tradisionele verpligting teenoor die pasient aan die een kant en die bewustheid dat hulpbronne beperk is aan die ander kant - hierdie spanning is 'n tragiese werklikheid in die medisyne. Om sodoende die mediese uitgawe te beperk, word medici versoek om gelyktydig te dien as die gemeenskap se agent om koste te beperk asook die pasient se agent vir maksimum gesondheid. Daaris toenemende druk op Medici om twee meesters te dien - die gemeenskap en die pasient. Om op te tree as hekwagter namens die gemeenskap, terwyl daar van die dolder verwag word om namens die pasient as sy advokaat op te tree. Hoofstuk sewe ondersoek, beide die hekwagter en advokaat en daar word gepoog om die vraag te beantwoord of dolders kan en inderdaad durf poog om twee meesters gelyktydig te dien? Die finale hoofstuk dien as samebindende faldor van die verskeie uitgebreide argumente en pogings om oplossings te bied tot sommige van die vraagstukke

Space Mechanisms Lessons Learned Study. Volume 1: Summary

Hundreds of satellites have been launched to date. Some have operated extremely well and others have not. In order to learn from past operating experiences, a study was conducted to determine the conditions under which space mechanisms (mechanically moving components) have previously worked or failed. The study consisted of: (1) an extensive literature review that included both government contractor reports and technical journals; (2) communication and visits (when necessary) to the various NASA and DOD centers and their designated contractors (this included contact with project managers of current and prior NASA satellite programs as well as their industry counterparts); (3) requests for unpublished information to NASA and industry; and (4) a mail survey designed to acquire specific mechanism experience. The information obtained has been organized into two volumes. Volume 1 provides a summary of the lessons learned, the results of a needs analysis, responses to the mail survey, a listing of experts, a description of some available facilities and a compilation of references. Volume 2 contains a compilation of the literature review synopsis

Space Mechanisms Lessons Learned Study. Volume 2: Literature Review

Hundreds of satellites have been launched to date. Some have operated extremely well and others have not. In order to learn from past operating experiences, a study was conducted to determine the conditions under which space mechanisms (mechanically moving components) have previously worked or failed. The study consisted of an extensive literature review that included both government contractor reports and technical journals, communication and visits (when necessary) to the various NASA and DOD centers and their designated contractors (this included contact with project managers of current and prior NASA satellite programs as well as their industry counterparts), requests for unpublished information to NASA and industry, and a mail survey designed to acquire specific mechanism experience. The information obtained has been organized into two volumes. Volume 1 provides a summary of the lesson learned, the results of a needs analysis, responses to the mail survey, a listing of experts, a description of some available facilities, and a compilation of references. Volume 2 contains a compilation of the literature review synopsis