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Showing papers by "University of Maine published in 2000"


Journal ArticleDOI
12 Oct 2000-Nature
TL;DR: It is demonstrated that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.
Abstract: Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis' For this reason, it is important to understand the response of pelagic biota to increased iron supply Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days This drawdown was mostly due to the proliferation of diatom stocks But downward export of biogenic carbon was not increased Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction

1,412 citations


Journal ArticleDOI
TL;DR: The authors examines many explanations for why women have not risen to the top, including lack of line experience, inadequate career opportunities, gender differences in linguistic styles and socialization, gender-based stereotypes, the old boy network at the top and tokenism.
Abstract: Although the number of women in middle management has grown quite rapidly in the last two decades, the number of female CEOs in large corporations remains extremely low. This article examines many explanations for why women have not risen to the top, including lack of line experience, inadequate career opportunities, gender differences in linguistic styles and socialization, gender-based stereotypes, the old boy network at the top, and tokenism. Alternative explanations are also presented and analyzed, such as differences between female leadership styles and the type of leadership style expected at the top of organizations, feminist explanations for the underrepresentation of women in top management positions, and the possibility that the most talented women in business often avoid corporate life in favor of entrepreneurial careers.

912 citations


Journal ArticleDOI
TL;DR: This paper explored relationships among environmental attitudes, nonuse values for endangered species, and underlying motivations for contingent valuation (CV) responses and found that those with stronger pro-environmental attitudes were more likely to provide legitimate yes/no responses, while those with weaker attitudes were less likely to protest hypothetical CV scenarios.

631 citations


Journal ArticleDOI
01 Sep 2000-Geology
TL;DR: The human population has been increasing exponentially. as discussed by the authors states that the ability and motivation to modify the landscape by moving earth in construction and mining activities has also increased dramatically, and we have now become arguably the premier geomorphic agent sculpting the landscape, and the rate at which we are moving earth is increasing exponentially, and this constitutes an unintended additional human impact on the landscape.
Abstract: The human population has been increasing exponentially. Simultaneously, as digging sticks and antlers have given way to wooden plows, iron spades, steam shovels, and today’s huge excavators, our ability and motivation to modify the landscape by moving earth in construction and mining activities have also increased dramatically. As a consequence, we have now become arguably the premier geomorphic agent sculpting the landscape, and the rate at which we are moving earth is increasing exponentially. As hunter-gatherer cultures were replaced by agrarian societies to feed this expanding population, erosion from agricultural fields also, until recently, increased steadily. This constitutes an unintended additional human impact on the landscape.

456 citations


Journal ArticleDOI
TL;DR: In this paper, a general framework within which previously isolated results can now be properly understood was provided, and several previously conjectured evaluations, including an intriguing conjecture of Don Zagier were proved.
Abstract: Historically, the polylogarithm has attracted specialists and non-specialists alike with its lovely evaluations. Much the same can be said for Euler sums (or multiple harmonic sums), which, within the past decade, have arisen in combinatorics, knot theory and high-energy physics. More recently, we have been forced to consider multidimensional extensions encompassing the classical polylogarithm, Euler sums, and the Riemann zeta function. Here, we provide a general framework within which previously isolated results can now be properly understood. Applying the theory developed herein, we prove several previously conjectured evaluations, including an intriguing conjecture of Don Zagier.

403 citations


Journal ArticleDOI
15 Dec 2000
TL;DR: The gas-phase reaction of (3-aminopropyl)dimethylethoxysilane (APDMES) with silica with and without amine catalysts has been studied using infrared spectroscopy and evidence is provided that shows that the aminosilane initially adsorbs via hydrogen bonding of both ethoxy and aminopropy moieties of the silane with the surface hydroxyl groups.
Abstract: The gas-phase reaction of (3-aminopropyl)dimethylethoxysilane (APDMES) with silica with and without amine catalysts has been studied using infrared spectroscopy. Evidence is provided that shows that the aminosilane initially adsorbs via hydrogen bonding of both ethoxy and aminopropyl moieties of the silane with the surface hydroxyl groups. As the reaction proceeds, the number of silane molecules attached to the surface via a Si-O-Si linkage increases primarily at the expense of the number of H-bonded ethoxy groups. The conversion is due to a catalytic process involving the aminopropyl end of gaseous APDMES molecules. On the other hand, the H-bonded aminopropyl groups are less reactive and only a small portion of these groups participates in Si-O-Si bond formation. At the end of the reaction there remain about 50% of the adsorbed APDMES attached by the H-bonded aminopropyl group. Attempts to block the adsorption of the aminopropyl end through the use of the more strongly H-bonded triethylamine proved unsuccessful. The use of preadsorbed triethylamine or 1 : 10 mixtures of triethylamine/APDMES accelerates the reaction but in the end leads to the same final distribution of products on the surface. Copyright 2000 Academic Press.

392 citations


Journal ArticleDOI
TL;DR: For the first time, a data analysis recognizes a clade of acoelomates, the Platyzoa, which is expanded to include the enigmatic phylum Cycliophora, as sister group to Syndermata.
Abstract: Triploblastic relationships were examined in the light of molecular and morphological evidence. Representatives for all triploblastic "phyla" (except Loricifera) were represented by both sources of phylogenetic data. The 18S ribosomal (rDNA) sequence data for 145 terminal taxa and 276 morphological characters coded for 36 supraspecific taxa were combined in a total evidence regime to determine the most consistent picture of triploblastic relationships for these data. Only triploblastic taxa are used to avoid rooting with distant outgroups, which seems to happen be? cause of the extreme distance tl tat separates diploblastic from triploblastic taxa according to the 18S rDNA data. Multiple phylogenetic analyses performed with variable analysis parameters yield largely inconsistent results for certain groups such as Chaetognatha, Acoela, and Nemertodermatida. A normalized incongruence length metric is used to assay the relative merit of the multiple analy? ses. The combined analysis having the least character incongruence yields the following scheme of relationships of four main clades: (1) Deuterostomia (((Echinodermata + Enteropneusta) (Cephalo? chordata (Urochordata + Vertebrata)))); (2) Ecdysozoa ((((Priapulida + Kinorhyncha) (Nematoda + Nematomorpha)) ((Onychophora + Tardigrada) Arthropoda))); (3) Trochozoa (((Phoronida + Bra? chiopoda) (Entoprocta (Nemertea (Sipuncula (Mollusca (Pogonophora (Echiura + Annelida)))))))); and (4) Platyzoa (((Gnathostomulida (Cycliophora + Syndermata)) (Gastrotricha + Plathelminthes))). Chaetognatha, Nemertodermatida, and Bryozoa cannot be assigned to any one of these four groups. For the first time, a data analysis recognizes a clade of acoelomates, the Platyzoa (sensu Cavalier-Smith, Biol. Rev. 73:203-266, 1998). Other relationships that corroborate some morphological analyses are the existence of a clade that groups Gnathostomulida + Syndermata (= Gnathifera), which is ex? panded to include the enigmatic phylum Cycliophora, as sister group to Syndermata. (Ecdysozoa; Metazoa; morphology; phylogeny; Platyzoa; 18S rRNA; Triploblastica.)

349 citations


Journal ArticleDOI
TL;DR: This review focuses on how life-history attributes influence the production dynamics of stream insects and other macroinvertebrates, and limits current understanding of mechanisms controlling stream productivity.
Abstract: ▪ Abstract Studies of the production of stream insects are now numerous, and general factors controlling the secondary production of stream communities are becoming evident. In this review we focus on how life-history attributes influence the production dynamics of stream insects and other macroinvertebrates. Annual production of macroinvertebrate communities in streams world-wide ranges from approximately 100 to 103 g dry mass m−2. High levels are reported for communities dominated by filter feeders in temperate streams. Filter feeding enables the accrual and support of high biomass, which drives the very highest production. Frequently disturbed communities in warm-temperate streams are also highly productive. Biomass accrual by macroinvertebrates is limited in these streams, and production is driven by rapid growth rates rather than high biomass. The lowest production, reported for macroinvertebrate communities of cool-temperate and arctic streams, is due to the constraints of low seasonal temperatures ...

309 citations


Journal ArticleDOI
12 Oct 2000-Nature
TL;DR: It is argued that the ribbon-like bloom was produced from the fertilized patch through stirring, growth and diffusion, and an estimate of the stirring rate is derived, which may have prevented the onset of silicate limitation, and so allowed the bloom to continue for as long as there was sufficient iron.
Abstract: The growth of populations is known to be influenced by dispersal, which has often been described as purely diffusive. In the open ocean, however, the tendrils and filaments of phytoplankton populations provide evidence for dispersal by stirring. Despite the apparent importance of horizontal stirring for plankton ecology, this process remains poorly characterized. Here we investigate the development of a discrete phytoplankton bloom, which was initiated by the iron fertilization of a patch of water (7 km in diameter) in the Southern Ocean. Satellite images show a striking, 150-km-long bloom near the experimental site, six weeks after the initial fertilization. We argue that the ribbon-like bloom was produced from the fertilized patch through stirring, growth and diffusion, and we derive an estimate of the stirring rate. In this case, stirring acts as an important control on bloom development, mixing phytoplankton and iron out of the patch, but also entraining silicate. This may have prevented the onset of silicate limitation, and so allowed the bloom to continue for as long as there was sufficient iron. Stirring in the ocean is likely to be variable, so blooms that are initially similar may develop very differently.

264 citations


Journal ArticleDOI
17 Feb 2000-Nature
TL;DR: This paper showed that mytilid taxa are closely related to vent and seep taxa, and that this entire group is divergent from other Mytilidae, and suggested that decomposing wood and bone may have served as "steps" for the introduction of mytilids to vents and seeps.
Abstract: Symbiont-containing mussels (Mytilidae) are found at hydrothermal vents and cold seeps on the ocean floor, but it is not known whether these taxa represent an ancient lineage endemic to these surroundings or are more recent invaders Here we show that several small and poorly known mussels, commonly found on sunken wood and whale bones in the deep sea, are closely related to vent and seep taxa, and that this entire group is divergent from other Mytilidae Our results indicate that vents and seeps were recently invaded by modern mytilid taxa and suggest that decomposing wood and bone may have served as ‘steps’ for the introduction of mytilid taxa to vents and seeps

254 citations


Journal ArticleDOI
TL;DR: Most taxa show indications of the evolutionary consequences of sperm limitation even when population level, ecological effects are minimal, and recent surveys of naturally spawning populations indicate fairly high fertilization levels in many taxa.
Abstract: Successful fertilization in marine organisms that release sperm into seawater is potentially limited by the rapid dilution of gametes; cases of severe sperm limitation have been demonstrated in nature. However, recent surveys of naturally spawning populations indicate fairly high fertilization levels in many taxa. The extreme selection exerted by sperm limitation has resulted in numerous adaptations to reduce sperm limitation and enhance fertilization. Thus, most taxa show indications of the evolutionary consequences of sperm limitation even when population level, ecological effects are minimal.

Journal ArticleDOI
TL;DR: In this article, the authors show that the absorption edges of K[Au(CN)2] and K[Ag(CN2] solutions undergo progressive red shifts with an increase in concentration up to near the saturation limits, whereupon total red shifts of 13.4 × 103 and 11.9 × 103 cm-1 are obtained from the respective maxima of the corresponding lowest energy monomer bands.
Abstract: Dicyanoaurate(I) and dicyanoargentate(I) ions undergo significant oligomerization in aqueous and methanolic solutions. The absorption edges of K[Au(CN)2] and K[Ag(CN)2] solutions undergo progressive red shifts with an increase in concentration up to near the saturation limits, whereupon total red shifts of 13.4 × 103 and 11.9 × 103 cm-1 are obtained from the respective maxima of the corresponding lowest energy monomer bands. Two types of deviations from Beer's law are observed: a negative deviation for the monomers' MLCT bands and a positive deviation for the oligomers' bands. Increasing the concentration within a given concentration range leads to red shifts in the oligomers' absorption and/or excitation bands dominant in that range, while further increases in concentration lead to the appearance of new lower energy bands. Electronic structure calculations suggest that this behavior is attributed to metal−metal interactions between neighboring Au(CN)2- or Ag(CN)2- ions. Formation constants of 1.50 ± 0.0...

Journal ArticleDOI
TL;DR: In this article, the dominant rocks are basalts with geochemical characteristics distinct from those of mid-ocean ridge basalts and the presence of wood fragments, charcoal, pollen, spores and seeds in the shallow water sediments overlying the igneous basement show that the growth rate of the plateau was sufficient to form subaerial landmasses.

Journal ArticleDOI
TL;DR: Emotional management skills were examined in 21 sexually maltreated girls and their nonmaltreated peers to determine how the experience of sexual maltreatment may interfere with normative emotional development and indicated that sexually malt treated girls demonstrate lower emotional understanding and decreased ability to regulate their emotions.
Abstract: Research has demonstrated that children who experience familial sexual maltreatment are at risk for developing psychological difficulties characterized by emotional and behavioral dysregulation. Surprisingly, however, little attention has been directed toward identifying processes in emotional development that differ in maltreated and nonmaltreated children. From a developmental psychopathology perspective, the present study examined emotion management skills (i.e., emotional understanding, emotion regulation) in 21 sexually maltreated girls and their nonmaltreated peers to determine how the experience of sexual maltreatment may interfere with normative emotional development. Findings indicated that sexually maltreated girls, in comparison to their nonmaltreated peers, demonstrate lower emotional understanding and decreased ability to regulate their emotions in accordance with cultural expectations. Further, maltreated girls expected less emotional support and more relational conflict from parents in response to sadness displays and from parents and peers in response to anger displays. These findings will be discussed from the functionalist approach to emotional development, emphasizing the importance of social context (e.g., maltreating, nonmaltreating) in the development of children's emotion management skills.

Journal ArticleDOI
TL;DR: Data indicate that southern hemisphere mussels arose from a migration event from the northern hemisphere during the Pleistocene via an Atlantic route, suggesting a second, more recent migration to the southern hemisphere.
Abstract: Many marine species, including mussels in the Mytilus edulis species group (i.e. M. edulis L., M. galloprovincialis Lamarck, and M. trossulus Gould), have an antitropical distribution pattern, with closely related taxa occurring in high latitudes of the northern and southern hemispheres but being absent from the tropics. We tested four hypotheses to explain the timing and route of transequatorial migration by species with antitropical distributions. These hypotheses yield different predictions for the phylogenetic relationship of southern hemisphere taxa relative to their northern counter-parts. The three Mytilus species were used to test these hypotheses since they exhibit a typical antitropical distribution and representative taxa occur in both the Pacific and Atlantic. Two types of mtDNA lineages were found among populations of mussels collected from the southern hemisphere between 1988 and 1996; over 90% of the mtDNA lineages formed a distinct subclade which, on average, had 1.4% divergence from haplotypes found exclusively in northern Atlantic populations of M. galloprovincialis. These data indicate that southern hemisphere mussels arose from a migration event from the northern hemisphere during the Pleistocene via an Atlantic route. The remainder of the southern hemisphere lineages (<10%) were very closely related to mtDNA haplotypes found in both M. edulis and M. galloprovincialis in the northern hemisphere, suggesting a second, more recent migration to the southern hemisphere. There was no evidence that southern hemisphere mussels arose from Pacific populations of mussels.

Journal ArticleDOI
TL;DR: The results from the second phase of the European Ice sheet Modelling Initiative (EISMINT) as discussed by the authors showed that radial symmetry implied in the experimental design can, under certain circumstances, break down with the formation of distinct, regularly spaced spokes of cold ice which extended from the interior of the ice sheet outward to the surrounding zone of basal melt.
Abstract: This paper discusses results from the second phase of the European Ice sheet Modelling Initiative (EISMINT). It reports the intercompartison of ten operational ice-sheet models and uses a series of experiments to examine the implications of thermomechanical coupling for model behaviour. A schematic, circular ice sheet is used in the work which investigates both steady states and the response to stepped changes in climate. The major finding is that radial symmetry implied in the experimental design can, under certain circumstances, break down with the formation of distinct, regularly spaced spokes of cold ice which extended from the interior of the ice sheet outward to the surrounding zone of basal melt. These features also manifest themselves in the thickness and velocity distributions predicted by the models. They appear to be a common feature to all of the models which took part in the intercomparison, and may stem from interactions between ice temperature, flow and surface form. The exact nature of these features varies between models, and their existence appears to be controlled by the overall thermal regimne of the ice sheet. A second result is that there is considerable agreement between the models in their predictions of global-scale response to imposed climate change.

Journal ArticleDOI
TL;DR: The authors provide a compendium of evaluation methods for the Riemann zeta function, presenting formulae ranging from historical attempts to recently found convergent series to curious oddities old and new.

Journal ArticleDOI
TL;DR: This paper discusses issues related to the use of ontologies in the development of urban geographic information systems and proposes the creation of software components from diverse ontologies as a way to share knowledge and data.

Journal ArticleDOI
TL;DR: The atypicalities in the vocal behavior of children with autism appeared to be independent of individual differences in joint attention skill, suggesting that a multiple process model may be needed to describe early social-communication impairments in children with Autism.
Abstract: This study was designed to evaluate the nature of early vocal behaviors in young children with autism. Recent methodological and conceptual advances in the study of infant preverbal vocalizations were used to provide a detailed examination of the vocal behavior of young preverbal children with autism and comparison children with developmental delays. Results revealed that children with autism did not have difficulty with the expression of well-formed syllables (i.e., canonical babbling). However, children with autism did display significant impairments in vocal quality (i.e., atypical phonation). Specifically, autistic children produced a greater proportion of syllables with atypical phonation than did comparison children. Consistent with prior reports, the children with autism also displayed a deficit in joint attention behaviors. Furthermore, the atypicalities in the vocal behavior of children with autism appeared to be independent of individual differences in joint attention skill, suggesting that a multiple process model may be needed to describe early social-communication impairments in children with autism. Data are discussed in terms of their implications for future theoretical and applied research, including efforts to enhance the specificity of early diagnostic procedures.

Journal ArticleDOI
TL;DR: In this article, the authors evaluate the importance of three parameters on vertical flow in peatlands: regional slope, permeability of the mineral soil underlying the peat, and peatland topography.

Journal ArticleDOI
TL;DR: A DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay is developed and basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.
Abstract: We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.

Journal ArticleDOI
TL;DR: More than 250 radiocarbon dates of lacustrine algae and marine shells afford a chronology for Ross Sea drift in eastern Taylor Valley dates of algae that lived in ice-dammed Glacial Lake Washburn as mentioned in this paper.
Abstract: More than 250 radiocarbon dates of lacustrine algae and marine shells afford a chronology for Ross Sea drift in eastern Taylor Valley Dates of algae that lived in ice‐dammed Glacial Lake Washburn

Journal ArticleDOI
TL;DR: In this article, four glacial drifts are exposed in eastern Taylor Valley and on Cape Bernacchi on the western side of McMurdo Sound, Ross Sea, Antarctica: Alpine I,Ross Sea, Wilson, and Bonney drifts.
Abstract: Four glacial drifts are exposed in eastern Taylor Valley and on Cape Bernacchi on the western side of McMurdo Sound, Ross Sea, Antarctica: Alpine I, Ross Sea, Wilson, and Bonney drifts. Bonney drif...

Journal ArticleDOI
15 Jun 2000-Vaccine
TL;DR: The efficacy of a DNA vaccine containing the glycoprotein gene of infectious hematopoietic necrosis virus, a rhabdovirus affecting trout and salmon, was investigated and induced protection in fish at a lower dose than is usually reported in mammalian DNA vaccine studies.

Journal ArticleDOI
TL;DR: The roles of temperature (T) and leaf-to-air vapor pressure deficit (VPD) in regulating net photosynthesis (A(net)) and stomatal conductance (G(s)) of red spruce were investigated in a field study and in a controlled environment experiment.
Abstract: The roles of temperature (T) and leaf-to-air vapor pressure deficit (VPD) in regulating net photosynthesis (A(net)) and stomatal conductance (G(s)) of red spruce (Picea rubens Sarg.) were investigated in a field study and in a controlled environment experiment. Both A(net) and G(s) exhibited a relatively flat response to temperatures between 16 and 32 degrees C. Temperatures between 32 and 36 degrees C markedly decreased both A(net) and G(s). Vapor pressure deficits above 2 kPa had significant effects of both A(net) and G(s). The influence of VPD on A(net) and G(s) fit a linear response model and did not interact significantly with T effects.

Journal ArticleDOI
TL;DR: At hatching, the oesophagus of haddock Melanogrammus aeglefinus lacks goblet cells, the intestine is a simple undifferentiated tube, the liver is present as a rounded mass caudal to the heart, and numerous zymogen granules are present in the pancreas.
Abstract: At hatching, the oesophagus of haddock Melanogrammus aeglefinus lacks goblet cells, the intestine is a simple undifferentiated tube, the liver is present as a rounded mass caudal to the heart, and numerous zymogen granules are present in the pancreas. The first intestinal convolution appears at day 2, at the posterior end of the digestive tract. The oesophagus displays alcian blue and PAS positive mucus secreting cells on day 12, which become numerous by day 15. By day 18, epithelial cells of the posterior intestine show evidence of protein absorption in the form of supranuclear vacuoles. The swimbladder inflates in 50% of the larvae by day 22, although inflation rate is highly variable. By day 35, or 10 mm, a pyloric caecal ridge appears which separates the presumptive stomach, which is now showing evidence of gastric gland formation, from the intestine. This marks the beginning of digestive features characteristic of the juvenile stage.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the mechanism by which a deposit feeder can solubilize PAH from contaminated sediments as well as the implications of these mechanisms for factors controlling PAH bioavailability.
Abstract: We studied the mechanism(s) by which a deposit feeder can solubilize PAH from contaminated sediments as well as the implications of these mechanisms for factors controlling PAH bioavailability. Arenicola marina digestive fluids solubilize 4.6 μg mL-1 phenanthrene and 2.0 μg mL-1 benzo[a]pyreneconcentrations greater than the PAH's seawater solubilitieswhen incubated with pure PAH solids. This enhanced solubilization is largely due to surfactant micelles in the digestive fluid. In experiments with contaminated sediments that repeat the incubation or vary the solid−fluid ratio, these and other PAHs saturate at much lower concentrations (often between 0.01 and 0.1 μg mL-1). Less solubilization is likely due to sorption of digestive surfactants by sedimentary organic matter and competition from other sedimentary hydrophobic solutes, such as aliphatic hydrocarbons, for remaining micellar space. Nevertheless, gut fluid concentrations of high molecular weight PAHs are greater than those predicted from equilibrium...

Journal ArticleDOI
TL;DR: In this paper, the bioactive metals Fe, Mn, Cu, Zn and Ni in Narragansett Bay, RI were partitioned into soluble, colloidal and particulate size fractions using a combination of conventional and cross-flow filtrations.

Journal ArticleDOI
TL;DR: The rationale, architecture, and implementation of a next generation information gathering system—a system that integrates several areas of Artificial Intelligence research under a single umbrella is described.

BookDOI
21 Dec 2000
TL;DR: In this paper, a framework for exploring the linkages between ecosystems and human systems is proposed, where the authors explore the relationship between ecosystems, humans, and human-ecological interactions.
Abstract: Introduction A Framework for Exploring the Linkages Between Ecosystems and Human Systems - Cleveland et al Dynamic Systems Modeling - Costanza and Ruth Models Human-Ecosystem Interactions: A Simple Dynamic Integrated Model - Low et al Scale Misperceptions and the Spatial Dynamics of Socio-Ecological Systems with Examples in Fisheries - Wilson et al Investing in Irrigation Infrastructure - Ostrom et al Integrated Ecological Economic Modeling of the Patuxent River Watershed in Maryland - Costanza et al Models for Scoping and Consensus Building - Costanza and Ruth Modeling Summary/Conclusions - Low et al Empirical Studies Empirical Studies of Fisheries - Wilson et al CIPEC Forest Comparisons - Ostrom et al Irrigation Institutions in the Diverse Ecosystems of Nepal - Ostrom et al Empirical Studies at the National Level - Turner Empirical Summary/Conclusions Conclusions Conclusions and Remaining Questions Glossary