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Regulation Of Sup Expression Identifies Multiple Regulators Involved In Arabidopsis Floral Meristem Development, Hajime Sakai, Beth A. Krizek, Steven E. Jacobsen, Elliot M. Meyerowitz Sep 2000

Regulation Of Sup Expression Identifies Multiple Regulators Involved In Arabidopsis Floral Meristem Development, Hajime Sakai, Beth A. Krizek, Steven E. Jacobsen, Elliot M. Meyerowitz

Faculty Publications

During the course of flower development, floral homeotic genes are expressed in defined concentric regions of floral meristems called whorls. The SUPERMAN ( SUP, also called FLO10 ) gene, which encodes a C2H2-type zinc finger protein, is involved in maintenance of the stamen/carpel whorl boundary (the boundary between whorl 3 and whorl 4) in Arabidopsis. Here, we show that the regulation of SUP expression in floral meristems is complex, consisting of two distinct phases, initiation and maintenance. The floral meristem identity gene LEAFY ( LFY ) plays a role in the initiation phase through at least two pathways, which …

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On The Assignment Of Gender To Chicano Anglicisms: Processes And Results, Robert N. Smead Sep 2000

On The Assignment Of Gender To Chicano Anglicisms: Processes And Results, Robert N. Smead

Faculty Publications

The creation of neologisms through linguistic borrowing is a complex process. For donor language models to be transformed into host language replicas, phonological and morphological adaptation must take place. Part and parcel of that adaptation is the assignment of gender to loanwords in a host language like Spanish. The present article examines gender assignment in two corpora of loanwords (New Mexican and Southern Colorado Spanish: N=212 and General Chicano Spanish: N=595). Through the application of variable rule methodology (GoldVarb 2), five factors are posited as significant. Two of these categorically determine gender assignment when present: (1) the biological sex of …

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A Balanced Nitrogen Budget Of The Surface Layer Of The Southern Ross Sea, Antarctica, Walker O. Smith Jr., Vernon L. Asper Sep 2000

A Balanced Nitrogen Budget Of The Surface Layer Of The Southern Ross Sea, Antarctica, Walker O. Smith Jr., Vernon L. Asper

Faculty Publications

To understand marine biogeochemical cycles, it is critical to quantitatively balance organic matter transformations within the euphotic zone. Such an assessment for nitrogen is difficult because of lateral advection, uncertainties in individual measurements, the complexity of elemental transformations (including nitrification and denitrification), and the difficulty of collecting data on appropriate space and time scales. Two cruises were conducted to the southern Ross Sea, Antarctica, to understand the time-varying fluxes of nitrogen into its various pools. From these data a balanced inventory was constructed. Nitrate removal in the upper 200 m was balanced by particulate and dissolved organic nitrogen production, ammonification, …

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Using Hydrothermal Time Concepts To Model Seed Germination Response To Temperature Dormancy Loss And Priming Effects In Elymus Elymoides, Phil S. Allen, Susan E. Meyer, Susan B. Debaene-Gill Sep 2000

Using Hydrothermal Time Concepts To Model Seed Germination Response To Temperature Dormancy Loss And Priming Effects In Elymus Elymoides, Phil S. Allen, Susan E. Meyer, Susan B. Debaene-Gill

Faculty Publications

Hydrothermal time (HTT) describes progress toward seed germination under various combinations of incubation water potential (Ψ) and temperature (T). To examine changes in HTT parameters during dormancy loss, seeds from two populations of the bunchgrass Elymus elymoides were incubated under seven temperature regimes following dry storage at 10, 20 and 30 °C for intervals from 0 to 16 weeks. Fully after-ripened seeds were primed for 1 week at a range of s. Data on germination rate during priming were used to obtain a HTT equation for each seed population, while data obtained following transfer to water were used to calculate …

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New Insights Into The Size And Stoichiometry Of The Plasminogen Activator Inhibitor Type-1·Vitronectin Complex, T. J. Podor, S. G. Shaughnessy, M. N. Blackburn, C. B. Peterson Aug 2000

New Insights Into The Size And Stoichiometry Of The Plasminogen Activator Inhibitor Type-1·Vitronectin Complex, T. J. Podor, S. G. Shaughnessy, M. N. Blackburn, C. B. Peterson

Faculty Publications

Plasminogen activator inhibitor-type 1 (PAI-1) is the primary inhibitor of endogenous plasminogen activators that generate plasmin in the vicinity of a thrombus to initiate thrombolysis, or in the pericellular region of cells to facilitate migration and/or tissue remodeling. It has been shown that the physiologically relevant form of PAI-1 is in a complex with the abundant plasma glyco-protein, vitronectin. The interaction between vitronectin and PAI-1 is important for stabilizing the inhibitor in a reactive conformation. Although the complex is clearly significant, information is vague regarding the composition of the complex and consequences of its formation on the distribution and activity …

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Biological Implications Of A Discrete Mathematical Model For Collagen Deposition And Alignment In Dermal Wound Repair, J. C. Dallon, J. A. Sherratt, P. K. Maini, M. W. Ferguson Aug 2000

Biological Implications Of A Discrete Mathematical Model For Collagen Deposition And Alignment In Dermal Wound Repair, J. C. Dallon, J. A. Sherratt, P. K. Maini, M. W. Ferguson

Faculty Publications

We develop a novel mathematical model for collagen deposition and alignment during dermal wound healing. We focus on the interactions between fibroblasts, modelled as discrete entities, and a continuous extracellular matrix composed of collagen and a fibrin based blood clot. There are four basic interactions assumed in the model: fibroblasts orient the collagen matrix, fibroblasts produce and degrade collagen and fibrin and the matrix directs the fibroblasts and determines the speed of the cells. Several factors which influence the alignment of collagen are examined and related to current anti-scarring therapies using transforming growth factor " The most influential of these …

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Mutational Analysis Of The Tra Locus Of The Broad-Host-Range Streptomyces Plasmid Pij101, Gregg S. Pettis, Stanley N. Cohen Aug 2000

Mutational Analysis Of The Tra Locus Of The Broad-Host-Range Streptomyces Plasmid Pij101, Gregg S. Pettis, Stanley N. Cohen

Faculty Publications

The tra gene of Streptomyces lividans plasmid pIJ101 encodes a 621- amino-acid protein that can mediate both plasmid transfer and the interbacterial transfer of chromosomal genes (i.e., chromosome-mobilizing ability [Cma]) during mating. Here we report the results of in-frame insertional mutagenesis studies aimed at defining regions of Tra required for these functions. While hexameric linker insertions throughout the tra gene affected plasmid and chromosomal gene transfer, insertions in a 200-amino- acid region of the Tra protein that contains presumed nucleotide-binding motifs and that is widely conserved among a functionally diverse family of bacterial and plasmid proteins (K. J. Begg, S. …

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Aintegumenta Promotes Petal Identity And Acts As A Negative Regulator Of Agamous, Beth A. Krizek, Valerie Prost, Anthony Macias Aug 2000

Aintegumenta Promotes Petal Identity And Acts As A Negative Regulator Of Agamous, Beth A. Krizek, Valerie Prost, Anthony Macias

Faculty Publications

The Arabidopsis AINTEGUMENTA (ANT) gene has been shown previously to be involved in ovule development and in the initiation and growth of floral organs. Here, we show that ANT acts in additional processes during flower development, including repression of AGAMOUS (AG) in second whorl cells, promotion of petal epidermal cell identity, and gynoecium development. Analyses of ap2-1 ant-6 double mutants reveal that ANT acts redundantly with AP2 to repress AG in second whorl cells. The abaxial surface of ant petals contains features such as stomata and elongated, interdigitated cells that are not present on wild-type petals. …

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The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon Aug 2000

The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon

Faculty Publications

A high resolution, regional, non-linear, barotropic ocean model (2D POM) was used to show that a pressure difference between the Pacific and Indian Ocean does not significantly influence the total transport of the Indonesian throughflow.

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Flux Of Nutrients From Russian Rivers To The Arctic Ocean: Can We Establish A Baseline Against Which To Judge Future Changes?, R. M. Holmes, B. J. Peterson, V. V. Gordeev, A. V. Zhulidov, M. Meybeck, Richard B. Lammers, Charles J. Vorosmarty Aug 2000

Flux Of Nutrients From Russian Rivers To The Arctic Ocean: Can We Establish A Baseline Against Which To Judge Future Changes?, R. M. Holmes, B. J. Peterson, V. V. Gordeev, A. V. Zhulidov, M. Meybeck, Richard B. Lammers, Charles J. Vorosmarty

Faculty Publications

Climate models predict significant warming in the Arctic in the 21st century, which will impact the functioning of terrestrial and aquatic ecosystems as well as alter land‐ocean interactions in the Arctic. Because river discharge and nutrient flux integrate large‐scale processes, they should be sensitive indicators of change, but detection of future changes requires knowledge of current conditions. Our objective in this paper is to evaluate the current state of affairs with respect to estimating nutrient flux to the Arctic Ocean from Russian rivers. To this end we provide estimates of contemporary (1970s–1990s) nitrate, ammonium, and phosphate fluxes to the Arctic …

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Rescaling The Energy Function In Hopfield Networks, Tony R. Martinez, Xinchuan Zeng Jul 2000

Rescaling The Energy Function In Hopfield Networks, Tony R. Martinez, Xinchuan Zeng

Faculty Publications

In this paper we propose an approach that rescales the distance matrix of the energy function in the Hopfield network for solving optimization problems. We rescale the distance matrix by normalizing each row in the matrix and then adjusting the parameter for the distance term. This scheme has the capability of reducing the effects of clustering in data distributions, which is one of main reasons for the formation of invalid solutions. We evaluate this approach through a large number (20,000) simulations based on 200 randomly generated city distributions of the 10-city traveling salesman problem. The result shows that, compared to …

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Pyridoxamine, An Inhibitor Of Advanced Glycation Reactions, Also Inhibits Advanced Lipoxidation Reactions: Mechanism Of Action Of Pyridoxamine, Joelle M. Onorato, Alicia J. Jenkins, Suzanne R. Thorpe, John W. Baynes Jul 2000

Pyridoxamine, An Inhibitor Of Advanced Glycation Reactions, Also Inhibits Advanced Lipoxidation Reactions: Mechanism Of Action Of Pyridoxamine, Joelle M. Onorato, Alicia J. Jenkins, Suzanne R. Thorpe, John W. Baynes

Faculty Publications

Maillard or browning reactions lead to formation of advanced glycation end products (AGEs) on protein and contribute to the increase in chemical modification of proteins during aging and in diabetes. AGE inhibitors such as aminoguanidine and pyridoxamine (PM) have proven effective in animal model and clinical studies as inhibitors of AGE formation and development of diabetic complications. We report here that PM also inhibits the chemical modification of proteins during lipid peroxidation (lipoxidation) reactions in vitro, and we show that it traps reactive intermediates formed during lipid peroxidation. In reactions of arachidonate with the model protein RNase, PM prevented modification …

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Effects Of Fertilizer And Herbicide Application On Nantucket Pine Tip Moth Infestation (Lep., Tortricidae), David L. Kulhavy Jul 2000

Effects Of Fertilizer And Herbicide Application On Nantucket Pine Tip Moth Infestation (Lep., Tortricidae), David L. Kulhavy

Faculty Publications

A study of fertilizer and herbicide e}ects on Nantucket pine tip moth (NPTM), Rhyacionia frustrana (Comstock) infestations was conducted in loblolly pine (Pinus taeda L) plantations in Nacogdoches Co. Texas from 0877 to 0878. Both fertilizer and herbicide applications had effects on NPTM infestation level, pupal weight and host tree oleoresin production. Nitrogen fertilization increased infestation levels, whereas, phosphorus applications tends to decrease infestation rate. Herbicide treatment had a negative effect on NPTM infestations possibly because of decreased moisture stress and increased tree vigour. This is in contrast to general observations of increased NPTM infestations associated with reducing competing …

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Long-Term Pyrene Exposure Of Grass Shrimp, Palaemonetes Pugio, Affects Molting And Reproduction Of Exposed Males And Offspring Of Exposed Females, Eva Oberdörster, Marius Brouwer, Thea Hoexum-Brouwer, Steve Manning, John A. Mclachlan Jul 2000

Long-Term Pyrene Exposure Of Grass Shrimp, Palaemonetes Pugio, Affects Molting And Reproduction Of Exposed Males And Offspring Of Exposed Females, Eva Oberdörster, Marius Brouwer, Thea Hoexum-Brouwer, Steve Manning, John A. Mclachlan

Faculty Publications

The objective of this study was to investigate the impact of long-term pyrene exposure on molting and reproduction in the model estuarine invertebrate, the grass shrimp (Palaemonetes pugio). Grass shrimp were exposed to measured concentrations of 5.1, 15.0, and 63.4 ppb (mu g/L) pyrene for 6 weeks, during which time we determined molting and survivorship. At the end of the exposure, we immediately sacrificed some of the shrimp for biomarker (CYP1A and vitellin) analyses. The remaining shrimp were used to analyze fecundity and embryo survivorship during an additional 6 weeks after termination of pyrene exposure. Male shrimp at the highest …

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Labor Markets, Rationality, And Workers With Disabilities, Michael Ashley Stein Jul 2000

Labor Markets, Rationality, And Workers With Disabilities, Michael Ashley Stein

Faculty Publications

No abstract provided.

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Questions And Answers About General Education At Andrews University, Delmer Davis Jul 2000

Questions And Answers About General Education At Andrews University, Delmer Davis

Faculty Publications

No abstract provided.

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Type 1 Plasminogen Activator Inhibitor Binds To Fibrin Via Vitronectin, Thomas J. Podor, Cynthia B. Peterson, Daniel A. Lawrence, Steingrimur Stefansson, Stephen G. Shaughnessy, Denise M. Foulon, Martin Butcher, Jeffrey I. Weitz Jun 2000

Type 1 Plasminogen Activator Inhibitor Binds To Fibrin Via Vitronectin, Thomas J. Podor, Cynthia B. Peterson, Daniel A. Lawrence, Steingrimur Stefansson, Stephen G. Shaughnessy, Denise M. Foulon, Martin Butcher, Jeffrey I. Weitz

Faculty Publications

Type 1 plasminogen activator inhibitor (PAI-1), the primary inhibitor of tissue-type plasminogen activator (t-PA), circulates as a complex with the abundant plasma glycoprotein, vitronectin. This interaction stabilizes the inhibitor in its active conformation. In this report, the effects of vitronectin on the interactions of PAI-1 with fibrin clots were studied. Confocal microscopic imaging of platelet-poor plasma clots reveals that essentially all fibrin-associated PAI-1 colocalizes with fibrin-bound vitronectin. Moreover, formation of platelet-poor plasma clots in the presence of polyclonal antibodies specific for vitronectin attenuated the inhibitory effects of PAI-1 on t-PA-mediated fibrinolysis. Addition of vitronectin during clot formation markedly potentiates PAI-1-mediated …

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Comparison Of Charged Sheets And Corrected 3-D Ewald Calculations Of Long-Range Forces In Slab Geometry Electrolyte Systems With Solvent Molecules, Richard L. Rowley, Paul S. Crozier, Eckhard Spoht, Douglas Henderson Jun 2000

Comparison Of Charged Sheets And Corrected 3-D Ewald Calculations Of Long-Range Forces In Slab Geometry Electrolyte Systems With Solvent Molecules, Richard L. Rowley, Paul S. Crozier, Eckhard Spoht, Douglas Henderson

Faculty Publications

Two methods of calculating long-range intermolecular potentials are compared for an approximately 3 M aqueous electrolyte solution confined between two charged surfaces. We investigate the ionic density profiles using the charged-sheets method and the corrected three-dimensional (3D) Ewald method at two different system sizes and also compare the Coulomb forces directly. The corrected 3D Ewald method is recommended for the calculation of long-range potentials in systems of this nature because it is less system size dependent than the charged sheets method and the resultant forces are more consistent with periodic boundaries. However, the charged-sheets method for estimating long-range potentials in …

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A Comment On Coleoptera And Hymenoptera Diversity, Chris Carlton, Alfred Newfon, Margaret Thayer, George Ball, Eugene Hall, Andrew Smith, Maryliz Jameson, Brett Ratcliffe, Stewart Peck, Terry Seeno, Steven Lingafelter, Paul J. Johnson, William Warner, Paul Skelley Jun 2000

A Comment On Coleoptera And Hymenoptera Diversity, Chris Carlton, Alfred Newfon, Margaret Thayer, George Ball, Eugene Hall, Andrew Smith, Maryliz Jameson, Brett Ratcliffe, Stewart Peck, Terry Seeno, Steven Lingafelter, Paul J. Johnson, William Warner, Paul Skelley

Faculty Publications

No abstract provided.

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An Est-Enriched Comparative Map Of Brassica Oleracea And Arabidopsis Thaliana, Tien-Hung Lan, Terrye A. Delmonte, Kim P. Reischmann, Joel Hyman, Stanley P. Kowalski, Jim Mcferson, Stephen Kresovich, Andrew H. Paterson Jun 2000

An Est-Enriched Comparative Map Of Brassica Oleracea And Arabidopsis Thaliana, Tien-Hung Lan, Terrye A. Delmonte, Kim P. Reischmann, Joel Hyman, Stanley P. Kowalski, Jim Mcferson, Stephen Kresovich, Andrew H. Paterson

Faculty Publications

A detailed comparative map of Brassica oleracea and Arabidopsis thaliana has been established based largely on mapping of Arabidopsis ESTs in two Arabidopsis and four Brassica populations. Based on conservative criteria for inferring synteny, “one to one correspondence” between Brassica and Arabidopsis chromosomes accounted for 57% of comparative loci. Based on 186 corresponding loci detected in B. oleracea and A. thaliana, at least 19 chromosome structural rearrangements differentiate B. oleracea and A. thaliana orthologs. Chromosomal duplication in the B. oleracea genome was strongly suggested by parallel arrangements of duplicated loci on different chromosomes, which accounted for 41% of loci …

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Nitrogen Cycling In A Forest Stream Determined By A 15n Tracer Addition, Patrick J. Mulholland, Jennifer L. Tank, Diane M. Sanzone, Wilfred M. Wollheim, Bruce J. Peterson, Jackson R. Webster, Judy L. Meyer Jun 2000

Nitrogen Cycling In A Forest Stream Determined By A 15n Tracer Addition, Patrick J. Mulholland, Jennifer L. Tank, Diane M. Sanzone, Wilfred M. Wollheim, Bruce J. Peterson, Jackson R. Webster, Judy L. Meyer

Faculty Publications

Nitrogen uptake and cycling was examined using a six‐week tracer addition of 15N‐labeled ammonium in early spring in Walker Branch, a first‐order deciduous forest stream in eastern Tennessee. Prior to the 15N addition, standing stocks of N were determined for the major biomass compartments. During and after the addition, 15N was measured in water and in dominant biomass compartments upstream and at several locations downstream. Residence time of ammonium in stream water (5–6 min) and ammonium uptake lengths (23–27 m) were short and relatively constant during the addition. Uptake rates of NH4 were more variable, ranging from 22 to 37 …

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Movement Of The Biotin Carboxylase B-Domain As A Result Of Atp Binding, James B. Thoden, Carol Z. Blanchard, Hazel M. Holden, Grover L. Waldrop May 2000

Movement Of The Biotin Carboxylase B-Domain As A Result Of Atp Binding, James B. Thoden, Carol Z. Blanchard, Hazel M. Holden, Grover L. Waldrop

Faculty Publications

Acetyl-CoA carboxylase catalyzes the first committed step in fatty acid synthesis. In Escherichia coli, the enzyme is composed of three distinct protein components: biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase. The biotin carboxylase component has served for many years as a paradigm for mechanistic studies devoted toward understanding more complicated biotin-dependent carboxylases. The three-dimensional x-ray structure of an unliganded form of E. coli biotin carboxylase was originally solved in 1994 to 2.4-Å resolution. This study revealed the architecture of the enzyme and demonstrated that the protein belongs to the ATP-grasp superfamily. Here we describe the three-dimensional structure of the …

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Direct Nitric Oxide Signal Transduction Via Nitrosylation Of Iron-Sulfur Centers In The Soxr Transcription Activator, Huangen Ding, Bruce Demple May 2000

Direct Nitric Oxide Signal Transduction Via Nitrosylation Of Iron-Sulfur Centers In The Soxr Transcription Activator, Huangen Ding, Bruce Demple

Faculty Publications

Nitric oxide (NO) has diverse roles in intercellular communication and (at higher levels) in immune-mediated cell killing. NO reacts with many cellular targets, with cell-killing effects correlated to inactivation of key enzymes through nitrosylation of their iron-sulfur centers. SoxR protein, a redox-sensitive transcription activator dependent on the oxidation state of its binuclear iron-sulfur ([2Fe-2S]) centers, is also activated in Escherichia coli on exposure to macrophage-generated NO. We show here that SoxR activation by NO occurs through direct modification of the [2Fe-2S] centers to form protein-bound dinitrosyl-iron-dithiol adducts, which we have observed both in intact bacterial cells and in purified SoxR …

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Teaching The Ethics Of Biology, David Harris Phd, Carol K. Johansen May 2000

Teaching The Ethics Of Biology, David Harris Phd, Carol K. Johansen

Faculty Publications

Discusses the basic principles of ethics and ethical decision making as applied to biology. Ethical issues associated with biology; Theoretical basis of ethical decision-making; Models of ethical decision-making; Social implications of scientific experimentation and discovery.

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A Drosophila Esc-E(Z) Protein Complex Is Distinct From Other Polycomb Group Complexes And Contains Covalently Modified Esc, Joyce Ng, Craig M. Hart, Kelly Morgan, Jeffrey A. Simon May 2000

A Drosophila Esc-E(Z) Protein Complex Is Distinct From Other Polycomb Group Complexes And Contains Covalently Modified Esc, Joyce Ng, Craig M. Hart, Kelly Morgan, Jeffrey A. Simon

Faculty Publications

The extra sex combs (ESC) and Enhancer of zeste [E(Z)] proteins, members of the Polycomb group (PcG) of transcriptional repressors, interact directly and are coassociated in fly embryos. We report that these two proteins are components of a 600-kDa complex in embryos. Using gel filtration and affinity chromatography, we show that this complex is biochemically distinct from previously described complexes containing the PcG proteins Polyhomeotic, Polycomb, and Sex comb on midleg. In addition, we present evidence that ESC is phosphorylated in vivo and that this modified ESC is preferentially associated in the complex with E(Z). Modified ESC accumulates between 2 …

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Turbidite Megabeds In An Oceanic Rift Valley Recording Jokulhlaups Of Late Pleistocene Glacial Lakes Of The Western United States, G.G. Zuffa, W.R. Normark, F. Serra, Charlotte A. Brunner May 2000

Turbidite Megabeds In An Oceanic Rift Valley Recording Jokulhlaups Of Late Pleistocene Glacial Lakes Of The Western United States, G.G. Zuffa, W.R. Normark, F. Serra, Charlotte A. Brunner

Faculty Publications

Escanaba Trough is the southernmost segment of the Gorda Ridge and is filled by sandy turbidites locally exceeding 500 m in thickness. New results from Ocean Drilling Program (ODP) Sites 1037 and 1038 that include accelerator mass spectrometry (AMS) C-14 dates and revised petrographic evaluation of the sediment provenance, combined with high-resolution seismic-reflection profiles, provide a lithostratigraphic framework for the turbidite deposits. Three fining-upward units of sandy turbidites from the upper 365 m at ODP Site 1037 can be correlated with sediment recovered at ODP Site 1038 and Deep Sea Drilling Program (DSDP) Site 35. Six AMS C-14 ages in …

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Optical Properties Of The Kara Sea, Donald R. Johnson, Vernon L. Asper, Thomas Mcclimans, Alan D. Weidemann Apr 2000

Optical Properties Of The Kara Sea, Donald R. Johnson, Vernon L. Asper, Thomas Mcclimans, Alan D. Weidemann

Faculty Publications

This study was motivated by the need to understand dispersion processes which affect the redistribution of nuclear wastes in the Arctic from dump sites in the Kara Sea and in the rivers which flow into the Kara Sea. We focus on vertical profiles of light beam transmission and fluorometry made over the delta region fronting the Ob and Yenisey Rivers and over the East Novaya Zemlya Trough (ENZT). The delta region fronting the Ob River Estuary contains a large repository of particles in a dense bottom nepheloid layer with a maximum centered similar to 100 km in front of the …

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Researchers Explore Arctic Freshwater's Role In Ocean Circulation, Steven L. Forman, Wieslaw Maslowski, John T. Andrews, David Lubinski, Michael Steele, Jain Zhang, Richard B. Lammers, Bruce Peterson Apr 2000

Researchers Explore Arctic Freshwater's Role In Ocean Circulation, Steven L. Forman, Wieslaw Maslowski, John T. Andrews, David Lubinski, Michael Steele, Jain Zhang, Richard B. Lammers, Bruce Peterson

Faculty Publications

A critical, but insufficiently understood, component of global change is the influence of Arctic freshwater input on water mass exchange between the Arctic Ocean and Atlantic and Pacific Oceans. Four of the Earth's 10 largest river systems, the Mackenzie, Ob,Yenisei, and Lena, contribute water to the Arctic shore (Figure 1) from a vast watershed that drains continental interiors. This river discharge flows into the world's largest contiguous continental shelf and supplies over 50% (1823 km3 ) of the riverine input to the Arctic Ocean.

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Thermolysis Of Semicarbazones To The Corresponding Azines Through Reactive N-Substituted Isocyanate Intermediates, Shailesh N. Shah, N.K. Chudgar Apr 2000

Thermolysis Of Semicarbazones To The Corresponding Azines Through Reactive N-Substituted Isocyanate Intermediates, Shailesh N. Shah, N.K. Chudgar

Faculty Publications

Thermolysis of semicarbazones (I) to azines (II) occurs through reactive N-substituted isocyanate intermediates (Ia) which can be converted in situ to carbamates and N-substituted ureas.

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Effects Of Prolonged Soil Drought On Ch4 Oxidation In A Temperate Spruce Forest, W. Borken, R. Brumme, Y. J. Xu Mar 2000

Effects Of Prolonged Soil Drought On Ch4 Oxidation In A Temperate Spruce Forest, W. Borken, R. Brumme, Y. J. Xu

Faculty Publications

Our objective was to determine potential impacts of changes in rainfall amount and distribution on soil CH4 oxidation in a temperate forest ecosystem. We constructed a roof below the canopy of a 65-year-old Norway spruce forest (Picea abies (L.) Karst.) and simulated two climate change scenarios: (1) an extensively prolonged summer drought of 172 days followed by a rewetting period of 19 days in 1993 and (2) a less intensive summer drought of 108 days followed by a rewetting period of 33 days in 1994. CH4 oxidation, soil matric potential, and soil temperature were measured hourly to daily over a …

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