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University of Massachusetts Amherst

2000

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Acetate Oxidation Coupled To Fe(Iii) Reduction In Hyperthermophilic Microorganisms, Jason M. Tor, Kazem Kashefi, Derek Lovley Dec 2000

Acetate Oxidation Coupled To Fe(Iii) Reduction In Hyperthermophilic Microorganisms, Jason M. Tor, Kazem Kashefi, Derek Lovley

Derek Lovley

No hyperthermophilic microorganisms have previously been shown to anaerobically oxidize acetate, the key extracellular intermediate in the anaerobic oxidation of organic matter. Here we report that two hyperthermophiles, Ferroglobus placidus and “Geoglobus ahangari,” grow at 85°C by oxidizing acetate to carbon dioxide, with Fe(III) serving as the electron acceptor. These results demonstrate that acetate could potentially be metabolized within the hot microbial ecosystems in which hyperthermophiles predominate, rather than diffusing to cooler environments prior to degradation as has been previously proposed.

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Constant Mean Curvature Surfaces With Three Ends, Karsten Grosse-Brauckmann, Robert Kusner, John M. Sullivan Dec 2000

Constant Mean Curvature Surfaces With Three Ends, Karsten Grosse-Brauckmann, Robert Kusner, John M. Sullivan

Robert Kusner

We announce the classification of complete almost embedded surfaces of constant mean curvature, with three ends and genus zero. They are classified by triples of points on the sphere whose distances are the asymptotic necksizes of the three ends.

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Temporal Changes In The Observed Relationship Between Cloud Cover And Surface Air Temperature, Bomin Sun, Pavel Ya. Groisman, Raymond S. Bradley, Frank T. Keimig Dec 2000

Temporal Changes In The Observed Relationship Between Cloud Cover And Surface Air Temperature, Bomin Sun, Pavel Ya. Groisman, Raymond S. Bradley, Frank T. Keimig

Raymond S Bradley

The relationship between cloud cover and near-surface air temperature and its decadal changes are examined using the hourly synoptic data for the past four to six decades from five regions of the Northern Hemisphere: Canada, the United States, the former Soviet Union, China, and tropical islands of the western Pacific. The authors define the normalized cloud cover–surface air temperature relationship, NOCET or dT/dCL, as a temperature anomaly with a unit (one-tenth) deviation of total cloud cover from its average value. Then mean monthly NOCET time series (night- and daytime, separately) are area-averaged and parameterized as functions of surface air humidity …

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5. Burton Carl Anderson, Otto Vogl Dec 2000

5. Burton Carl Anderson, Otto Vogl

Otto Vogl

No abstract provided.

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Mean Annual Temperature Trends And Their Vertical Structure In The Tropical Andes, Mathias Yuille, Raymond S. Bradley Dec 2000

Mean Annual Temperature Trends And Their Vertical Structure In The Tropical Andes, Mathias Yuille, Raymond S. Bradley

Raymond S Bradley

Mean annual temperature trends in the tropical Andes were determined over the last six decades ( 1939-1998), to investigate the apparent inconsistency between the observed glacier retreat and the reported slight cooling trend in the lower tropical troposphere after 1979. Our results indicate that temperature in the tropical Andes has increased by 0. 10° - 0. I l °C/decade since 1939. The rate of warming has more than tripled over the last 25 years (0.32° - 0.34 °C/decade) and the last two years of the series, associated with the 1997/98 El Nino, were the warmest of the last six decades. …

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6. Ichitaro Uematsu, Otto Vogl, Teiji Tsuruta, Yoshiko Uematsu Nov 2000

6. Ichitaro Uematsu, Otto Vogl, Teiji Tsuruta, Yoshiko Uematsu

Otto Vogl

No abstract provided.

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Submillimeter Wave Astronomy Satellite Observations Of Extended Water Emission In Orion, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Oct 2000

Submillimeter Wave Astronomy Satellite Observations Of Extended Water Emission In Orion, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We have used the Submillimeter Wave Astronomy Satellite to map the ground-state 1_{10}-1_{01} transition of ortho-water at 557 GHz in the Orion molecular cloud. Water emission was detected in Orion over an angular extent of about 20 arcmin, or nearly 3 pc. The water emission is relatively weak, with line widths (3-6 km s^{-1}) and V_{LSR} velocities (9-11 km s^{-1}) consistent with an origin in the cold gas of the molecular ridge. We find that the ortho-water abundance relative to H_2 in the extended gas in Orion varies between 1 and 8x10^{-8}, with an average of 3x10^{-8}. The absence of …

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7. Richard S. Stein, Otto Vogl, Judith Balise Stein Oct 2000

7. Richard S. Stein, Otto Vogl, Judith Balise Stein

Otto Vogl

No abstract provided.

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Canaleparolina Darwiniensis, Gen. Nov., Sp. Nov., And Other Pillotinaceae Spirochetes From Insects, Andrew Wier, Jon Ashen, Lynn Margulis Sep 2000

Canaleparolina Darwiniensis, Gen. Nov., Sp. Nov., And Other Pillotinaceae Spirochetes From Insects, Andrew Wier, Jon Ashen, Lynn Margulis

Lynn Margulis (1938 - 2011)

We describe two new pillotinaceous spirochetes (Canaleparolina darwiniensis, Diplocalyx cryptotermitidis) and identify for the first time Hollandina pterotermitidisfrom both the subterranean termite Cryptotermes cavifrons and the wood-eating cockroach Cryptocercus punctulatus based on morphometric analysis of transmission electron micrographic thin sections. C. darwiniensis, gen. nov., sp. nov., limited to near Darwin, Australia, invariably is present on the surface of the treponeme-studded trichomonad Mixotricha paradoxa, a consistent inhabitant of the hindgut of healthy termite Mastotermes darwiniensis. The spirochete both attached to the surface of protists and free-swimming in the paunch (hindgut) lumen of the insect has 16 periplasmic flagella (16:32:16) and imbricated …

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8. Paolo Corradini, Otto Vogl, Brigitta Griesbeck Corradini Sep 2000

8. Paolo Corradini, Otto Vogl, Brigitta Griesbeck Corradini

Otto Vogl

No abstract provided.

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The Distribution Of Water Emission In M17sw, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Aug 2000

The Distribution Of Water Emission In M17sw, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We present a 17-point map of the M17SW cloud core in the 1_{10}-1_{01} transition of ortho-water at 557 GHz obtained with the Submillimeter Wave Astronomy Satellite. Water emission was detected in 11 of the 17 observed positions. The line widths of the water emission vary between 4 and 9 km s^{-1}, and are similar to other emission lines that arise in the M17SW core. A direct comparison is made between the spatial extent of the water emission and the ^{13}CO J = 5\to4 emission; the good agreement suggests that the water emission arises in the same warm, dense gas as …

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Water Abundance In Molecular Cloud Cores, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Aug 2000

Water Abundance In Molecular Cloud Cores, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We present Submillimeter Wave Astronomy Satellite (SWAS) observations of the 1_{10}-1_{01} transition of ortho-water at 557 GHz toward 12 molecular cloud cores. The water emission was detected in NGC 7538, Rho Oph A, NGC 2024, CRL 2591, W3, W3(OH), Mon R2, and W33, and was not detected in TMC-1, L134N, and B335. We also present a small map of the water emission in S140. Observations of the H_2^{18}O line were obtained toward S140 and NGC 7538, but no emission was detected. The abundance of ortho-water relative to H_2 in the giant molecular cloud cores was found to vary between 6x10^{-10} …

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A Model Of The Implementation Of Quality Management Systems For Credence Attributes, Corinna Noelke, Julie Caswell Aug 2000

A Model Of The Implementation Of Quality Management Systems For Credence Attributes, Corinna Noelke, Julie Caswell

Julie Caswell

We develop a model of the impact of food quality management systems (QMS) on competitiveness and markets. QMS seek to control the quality of a product as determined by the array of individual attributes it possesses. To date only a few studies have attempted to better understand the effect of the introduction of quality management systems. No model has been introduced which captures the interactions within the supply chain and at the interface with consumers when these systems are introduced.

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Dynamics Of Lattice Kinks, Panos Kevrekidis, M. I. Weinstein Aug 2000

Dynamics Of Lattice Kinks, Panos Kevrekidis, M. I. Weinstein

Panos Kevrekidis

In this paper we consider two models of soliton dynamics (the sine Gordon and the \phi^4 equations) on a 1-dimensional lattice. We are interested in particular in the behavior of their kink-like solutions inside the Peierls- Nabarro barrier and its variation as a function of the discreteness parameter. We find explicitly the asymptotic states of the system for any value of the discreteness parameter and the rates of decay of the initial data to these asymptotic states. We show that genuinely periodic solutions are possible and we identify the regimes of the discreteness parameter for which they are expected to …

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9. Oskar Friedrich Olaj, Otto Vogl Aug 2000

9. Oskar Friedrich Olaj, Otto Vogl

Otto Vogl

No abstract provided.

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Outdoor Allergens, H A. Burge, Christine A. Rogers Aug 2000

Outdoor Allergens, H A. Burge, Christine A. Rogers

Christine A. Rogers

Outdoor allergens are an important part of the exposures that lead to allergic disease. Understanding the role of outdoor allergens requires a knowledge of the nature of outdoor allergen-bearing particles, the distributions of their source, and the nature of the aerosols (particle types, sizes, dynamics of concentrations). Primary sources for outdoor allergens include vascular plants (pollen, fern spores, soy dust), and fungi (spores, hyphae). Nonvascular plants, algae, and arthropods contribute small numbers of allergen-bearing particles. Particles are released from sources into the air by wind, rain, mechanical disturbance, or active discharge mechanisms. Once airborne, they follow the physical laws that …

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10. Dietrich Braun, Otto Vogl Jul 2000

10. Dietrich Braun, Otto Vogl

Otto Vogl

No abstract provided.

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Modular Symbols And Hecke Operators, Paul E. Gunnells Jun 2000

Modular Symbols And Hecke Operators, Paul E. Gunnells

Paul Gunnells

We survey techniques to compute the action of the Hecke operators on the cohomology of arithmetic groups. These techniques can be seen as generalizations in different directions of the classical modular symbol algorithm, due to Manin and Ash-Rudolph. Most of the work is contained in papers of the author and the author with Mark McConnell. Some results are unpublished work of Mark McConnell and Robert MacPherson.

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Can We Protect Agricultural Land And The Scenic Rural Landscape? The Spatial Effects Of Three Land Protection Strategies In The Eastern United States, Elizabeth Brabec, Chip Smith Jun 2000

Can We Protect Agricultural Land And The Scenic Rural Landscape? The Spatial Effects Of Three Land Protection Strategies In The Eastern United States, Elizabeth Brabec, Chip Smith

Elizabeth Brabec

In order to assess the efficacy of the three most common types of agricultural land conservation in the United States, this study analyzes the spatial and visual quality of a purchase of development rights program and two regulatory programs — cluster and the transfer of development rights. The study compares the effectiveness of programs that have been in place for periods of 6 to 18 years, surveying three different communities in the urban fringe: 1. the transfer of development rights program in Montgomery County, Maryland, in effect since 1981, 2. Riverhead, New York’s farmland development rights acquisition program, administered by …

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Fragmentation, Impervious Surfaces And Water Quality: Quantifying The Effects Of Density And Spatial Arrangement, Elizabeth Brabec, Paul Richards, Stacey Schulte Jun 2000

Fragmentation, Impervious Surfaces And Water Quality: Quantifying The Effects Of Density And Spatial Arrangement, Elizabeth Brabec, Paul Richards, Stacey Schulte

Elizabeth Brabec

Impervious surfaces have for many years been recognized as an indicator of the intensity of the urban environment and, with the advent of urban sprawl, they have become a key issue in habitat health. In addition to the direct impacts to water quality, impervious surfaces fragment open space and habitat and are therefore a primary land use indicator of both water quality and ecological degradation. This paper develops an understanding of the land use planning implications of the interaction of impervious surfaces, water quality and the spatial form those surfaces take in a watershed. In order to clarify these relationships, …

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Direct And Fe(Ii) Mediated Reduction Of Technetium By Fe(Iii)-Reducing Bacteria, Jon R. Lloyd, V. A. Sole, Catherine V. Van Praagh, Derek Lovley Jun 2000

Direct And Fe(Ii) Mediated Reduction Of Technetium By Fe(Iii)-Reducing Bacteria, Jon R. Lloyd, V. A. Sole, Catherine V. Van Praagh, Derek Lovley

Derek Lovley

The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of Tc(VII) to Tc(IV), leading to the precipitation of TcO(2) at the periphery of the cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently as an electron donor for direct cell-mediated reduction of technetium, supported the reduction of Fe(III), and the Fe(II) formed was able to transfer electrons abiotically to Tc(VII). Tc(VII) reduction was comparatively inefficient via this indirect mechanism when soluble Fe(III) citrate was supplied to the cultures but was enhanced …

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Orbifold Quantum Cohomology, Weimin Chen Chen, Yongbin Ruan Jun 2000

Orbifold Quantum Cohomology, Weimin Chen Chen, Yongbin Ruan

Weimin Chen

This is a research announcement on a theory of Gromov-Witten invariants and quantum cohomology of symplectic or projective orbifolds. Our project started in the summer of 98 where our original motivation was to study the quantum cohomology under singular flops in complex dimension three. In this setting, we allow our three-fold to have terminal singularities which can be deformed into a symplectic orbifold. We spent the second half of 98 and most of spring of 99 to develop the foundation of Gromov-Witten invariants over orbifolds, including the key conceptual ingredient — the notion of good map. In the April of …

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11. Binglin He, Otto Vogl, Frank C. Ho (He Zhenchi) Jun 2000

11. Binglin He, Otto Vogl, Frank C. Ho (He Zhenchi)

Otto Vogl

No abstract provided.

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Consumer Choice Of Food Products And The Implications For Price Competition And For An Analysis Of Government Policy, Julie Caswell May 2000

Consumer Choice Of Food Products And The Implications For Price Competition And For An Analysis Of Government Policy, Julie Caswell

Julie Caswell

In this paper we develop a random coefficients discrete choice model to investigate what affected consumer demand for prepared frozen meals from 1993 to 1998, when government regulation of nutrition labeling changed from voluntary to mandatory. The model links individual consumer characteristics (e.g., income, knowledge about nutrition, nutrition label use) to underlying product characteristics (e.g., price, nutritional attributes) and allows us to obtain preference parameters for each consumer as well as demand elasticities with regard to product characteristics for each product considered. We find that prices, advertising, price reductions, and consumer preferences for taste have a significant effect on the …

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Effects Of Synchrony With Host Plant On Population Of A Spring-Feeding Lepidopteran, Joseph Elkinton, A. F. Hunter May 2000

Effects Of Synchrony With Host Plant On Population Of A Spring-Feeding Lepidopteran, Joseph Elkinton, A. F. Hunter

Joseph Elkinton

Comparisons of traits of outbreaking and nonoutbreaking leaf-eating Lepidoptera and Symphyta have shown that spring-feeding species are more likely to have outbreaks than are summer-feeding species. It has been suggested that variable synchrony with host budburst causes the population sizes of spring-feeding species to be more variable primarily because of the negative effects of older leaves on insects. While much evidence exists that leaf age can directly affect survival and reproduction of insects, few studies have looked at the population-level effects of variable phenology, and especially the potential for complex direct and indirect interactions with natural-enemy effects. To examine the …

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Lack Of Production Of Electron-Shuttling Compounds Or Solubilization Of Fe(Iii) During Reduction Of Insoluble Fe(Iii) Oxide Of Geobacter Metallireducens, Derek Lovley, Kelly P. Nevin May 2000

Lack Of Production Of Electron-Shuttling Compounds Or Solubilization Of Fe(Iii) During Reduction Of Insoluble Fe(Iii) Oxide Of Geobacter Metallireducens, Derek Lovley, Kelly P. Nevin

Kelly Nevin

Studies with the dissimilatory Fe(III)-reducing microorganism Geobacter metallireducens demonstrated that the common technique of separating Fe(III)-reducing microorganisms and Fe(III) oxides with semipermeable membranes in order to determine whether the Fe(III) reducers release electron-shuttling compounds and/or Fe(III) chelators is invalid. This raised doubts about the mechanisms for Fe(III) oxide reduction by this organism. However, several experimental approaches indicated that G. metallireducens does not release electron-shuttling compounds and does not significantly solubilize Fe(III) during Fe(III) oxide reduction. These results suggest that G. metallireducens directly reduces insoluble Fe(III) oxide.

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The Promoter Of The Yeast Ino4 Regulatory Gene:A Model Of The Simplest Yeast Promoter, John Lopes, Kelly A. Robinson May 2000

The Promoter Of The Yeast Ino4 Regulatory Gene:A Model Of The Simplest Yeast Promoter, John Lopes, Kelly A. Robinson

John Lopes

In Saccharomyces cerevisiae, the phospholipid biosynthetic genes are transcriptionally regulated in response to inositol and choline. This regulation requires the transcriptional activator proteins Ino4p and Ino2p, which form a heterodimer that binds to the UASINO element. We have previously shown that the promoters of the INO4 and INO2 genes are among the weakest promoters characterized in yeast. Because little is known about the promoters of weakly expressed yeast genes, we report here the analysis of the constitutive INO4 promoter. Promoter deletion constructs scanning 1,000 bp upstream of theINO4 gene identified a small region (−58 to −46) that is absolutely required …

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Dust Emissions From High-Redshift Qsos, C L. Carilli, K M. Bertoldi, K M. Menten, M P. Rupen, E Kreysa, Xiaohui Fan, Michael A. Strauss, Donald P. Schneider, A Bertarini, Min S. Yun, R Zylka Apr 2000

Dust Emissions From High-Redshift Qsos, C L. Carilli, K M. Bertoldi, K M. Menten, M P. Rupen, E Kreysa, Xiaohui Fan, Michael A. Strauss, Donald P. Schneider, A Bertarini, Min S. Yun, R Zylka

Min S. Yun

We present detections of emission at 250 GHz (1.2 mm) from two high-redshift QSOs from the Sloan Digital Sky Survey sample using the bolometer array at the IRAM 30 m telescope. The sources are SDSSp 015048.831004126.2 at z = 3.7 and SDSSp J033829.311002156.3 at z = 5.0; the latter is the third highest redshift QSO known and the highest redshift millimeter-emitting source yet identified. We also present deep radio continuum imaging of these two sources at 1.4 GHz using the Very Large Array. The combination of centimeter and millimeter observations indicate that the 250 GHz emission is most likely thermal …

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Fingering Instabilities Of Confined Elastic Layers In Tension, Kenneth R. Shull, Cynthia M. Flanigan, Alfred Crosby Apr 2000

Fingering Instabilities Of Confined Elastic Layers In Tension, Kenneth R. Shull, Cynthia M. Flanigan, Alfred Crosby

Alfred Crosby

Fingering instabilities similar to those commonly observed in viscous systems have been observed in purely elastic layers that are strained in tension. The instability is driven by the release of lateral constraints within a confined elastic layer and is observed when the lateral confinement significantly exceeds the thickness of the elastic layer. Our results show convincingly that yielding or flow of a material is not required in order for fingering to be initiated in a confined material.

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State By State Groundwater Standards Survey Apr 2000

State By State Groundwater Standards Survey

Paul T. Kostecki

No abstract provided.

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