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2001

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Articles 481 - 510 of 2477

Full-Text Articles in Life Sciences

Factors Influencing Oviposition Among Pond-Breeding Amphibians: Exotic Vegetation, Oviposition Braces, And Cover, Catherine Mary Callison Jul 2001

Factors Influencing Oviposition Among Pond-Breeding Amphibians: Exotic Vegetation, Oviposition Braces, And Cover, Catherine Mary Callison

Dissertations and Theses

I examined oviposition in four pond-breeding amphibians (northwestern salamander [Ambystoma gracile], long-toed salamander [Ambystoma macrodactylum], Pacific treefrog [Hyla regilla], northern red-legged frog [Rana aurora aurora]), at Burlington Bottoms, a lowland riverine site in northwestern Oregon, to determine whether differential use of native versus exotic plant substrates occurs. I found differential use in all four species, but use was inconsistent with the hypothesis that selection for native plants (or selection against exotic plants) was occurring. If selection was occurring, the pattern implied that reed canarygrass (Phalaris arundinacea), a widespread exotic in this lowland system, was sometimes favored. However, inconsistent use of …


Sir3-Dependent Assembly Of Supramolecular Chromatin Structures In Vitro, Philippe T. Georgel, Madeleine A. Palacios Debeer, Gregory Pietz, Catherine A. Fox, Jeffrey C. Hansen Jul 2001

Sir3-Dependent Assembly Of Supramolecular Chromatin Structures In Vitro, Philippe T. Georgel, Madeleine A. Palacios Debeer, Gregory Pietz, Catherine A. Fox, Jeffrey C. Hansen

Biological Sciences Faculty Research

Baculovirus-expressed recombinant Sir3p (rSir3p) has been purified to near homogeneity, and its binding to naked DNA, mononucleosomes, and nucleosomal arrays has been characterized in vitro. At stoichiometric levels rSir3p interacts with intact nucleosomal arrays, mononucleosomes, and naked DNA, as evidenced by formation of supershifted species on native agarose gels. Proteolytic removal of the core histone tail domains inhibits but does not completely abolish rSir3p binding to nucleosomal arrays. The linker DNA in the supershifted complexes remains freely accessible to restriction endonuclease digestion, suggesting that both the tail domains and nucleosomal DNA contribute to rSir3p–chromatin interactions. Together these data indicate …


Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger Jul 2001

Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger

Specimens by Name

No abstract provided.


Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger Jul 2001

Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger

Specimens by Name

No abstract provided.


The Neuropeptide Y Y5 Receptor Mediates The Blockade Of "Photic-Like" Nmda-Induced Phase Shifts In The Golden Hamster, P. C. Yannielli, Mary E. Harrington Jul 2001

The Neuropeptide Y Y5 Receptor Mediates The Blockade Of "Photic-Like" Nmda-Induced Phase Shifts In The Golden Hamster, P. C. Yannielli, Mary E. Harrington

Psychology: Faculty Publications

Circadian or daily rhythms generated from the mammalian suprachiasmatic nuclei (SCN) of the hypothalamus can be synchronized by light and nonphotic stimuli. Whereas glutamate mediates photic information, nonphotic information can in some cases be mediated by neuropeptide Y (NPY) or serotonin. NPY or serotonin can reduce the phase-resetting effect of light or glutamate; however, the mechanisms and level of interaction of these two kinds of stimuli are unknown. Here we investigate the effect of NPY on the NMDA-induced phase shift of the hamster SCN circadian neural activity rhythm by means of single-unit recording techniques. NMDA (10-100 μM) applied in the …


Vitis Cinerea Noronha, John E. Ebinger Jul 2001

Vitis Cinerea Noronha, John E. Ebinger

Specimens by Name

No abstract provided.


Lysimachia Lanceolata Walter, Bob Edgin Jul 2001

Lysimachia Lanceolata Walter, Bob Edgin

Specimens by Name

No abstract provided.


Verbena Urticifolia L., Bob Edgin Jul 2001

Verbena Urticifolia L., Bob Edgin

Specimens by Name

No abstract provided.


Avian And Mammalian Use Of Three Small Urban Wetlands Invaded By A Pest Species, Reed Canarygrass (Phalaris Arundinacea L.), Laurie Dizney Jul 2001

Avian And Mammalian Use Of Three Small Urban Wetlands Invaded By A Pest Species, Reed Canarygrass (Phalaris Arundinacea L.), Laurie Dizney

Dissertations and Theses

Small urban wetlands are being destroyed and degraded at an alarming rate. One result of degradation is invasion by pest species, such as reed canarygrass (Phalaris arundinacea L. ). Reed canarygrass forms virtual monocultures in a wide range of wetland types. Wetlands normally have high plant species richness and abundance, which is widely believed to lead to faunal diversity. The purpose of the present study was to determine to what extent birds and mammals use a wetland dominated by reed canarygrass. The research was conducted at Tualatin Hills Nature Park in Beaverton, Washington County, Oregon. I examined three sites …


The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner Jul 2001

The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH2-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is …


Performance Of A Grid-Connected Photovoltaic System Using Actual And Kriged Hourly Solar Radiation, G. G. Merino, David Jones, Laverne E. Stetson Jul 2001

Performance Of A Grid-Connected Photovoltaic System Using Actual And Kriged Hourly Solar Radiation, G. G. Merino, David Jones, Laverne E. Stetson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In this article the performance of a grid-connected PV system supplying a farmstead was evaluated using a commercially available energy balance simulation model, Hybrid2. By performing annual hourly simulations, the influence of system size, actual radiation data, and estimated radiation data on economic and energy production were assessed. The estimated radiation data were developed from kriging actual radiation data from 16 weather stations in western Nebraska. The results indicated that the capital costs associated with a PV system dictate the economic performance of the overall system. The energy costs associated with the grid-connected PV system were six times the retail …


Parthenocissus Quinquefolia (L.) Planch., Loy R. Phillippe, John E. Ebinger Jul 2001

Parthenocissus Quinquefolia (L.) Planch., Loy R. Phillippe, John E. Ebinger

Specimens by Name

No abstract provided.


Cypripedium Calceolus Var. Pubescens (Willd.) Correll, John E. Ebinger Jul 2001

Cypripedium Calceolus Var. Pubescens (Willd.) Correll, John E. Ebinger

Specimens by Name

No abstract provided.


Verbena Stricta Vent., John E. Ebinger Jul 2001

Verbena Stricta Vent., John E. Ebinger

Specimens by Name

No abstract provided.


Maclura Pomifera (Raf.) Schneid., John E. Ebinger Jul 2001

Maclura Pomifera (Raf.) Schneid., John E. Ebinger

Specimens by Name

No abstract provided.


Acer Negundo L., John E. Ebinger Jul 2001

Acer Negundo L., John E. Ebinger

Specimens by Name

No abstract provided.


Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger Jul 2001

Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger

Specimens by Name

No abstract provided.


Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger Jul 2001

Parthenocissus Quinquefolia (L.) Planch., John E. Ebinger

Specimens by Name

No abstract provided.


Vitis Aestivalis F.Michx., John E. Ebinger Jul 2001

Vitis Aestivalis F.Michx., John E. Ebinger

Specimens by Name

No abstract provided.


Acer Negundo L., John E. Ebinger Jul 2001

Acer Negundo L., John E. Ebinger

Specimens by Name

No abstract provided.


The Foraging Ecology Of The Juvenile Gopher Tortoise, Gopheruspol Yphemus, Terri Anne Stilson Jul 2001

The Foraging Ecology Of The Juvenile Gopher Tortoise, Gopheruspol Yphemus, Terri Anne Stilson

USF Tampa Graduate Theses and Dissertations

Food plant preferences of juvenile gopher tortoises, Gopherus polyphemus, were investigated in a west central Florida population. The juvenile gopher tortoises were free-ranging and were located in a sandhill habitat subject to yearly prescribed burns. Diet was determined by foraging observations, in which the number of bites taken per taxon, the number of plants sampled per taxon, and the amount of each taxon available along the foraging path were recorded. Preference was determined with Manly's alpha index of preference and Jacob's D electivity index. Selected plants in the habitat were analyzed for relative nitrogen content to investigate whether preferred …


Sustaining Biological Diversity In Early Successional Communities: The Challenge Of Managing Unpopular Habitats, Robert A. Askins Jul 2001

Sustaining Biological Diversity In Early Successional Communities: The Challenge Of Managing Unpopular Habitats, Robert A. Askins

Biology Faculty Publications

No abstract provided.


Center For Grassland Studies Newsletter, Summer 2001, Volume 7, No. 3 Jul 2001

Center For Grassland Studies Newsletter, Summer 2001, Volume 7, No. 3

Center for Grassland Studies: Newsletters

The Lesser Prairie-chickens of Kansas’ Sandsage Prairies by Paul Johnsgard, Regents Professor/Professor Emeritus, School of Biological Sciences, UNL

Revisiting Nebraska's Mammals by Patricia Freeman, University of Nebraska State Museum

CGS Citizens Advisory Council Tours Southeast Nebraska

Beef and Forage Specialists Tour Nebraska Sand Hills

Don’t Forget the Nebraska Grazing Conference!

Landscape Ecology Symposium in April 2002

Grazing Sudangrass, Pearl Millet, and Sorghum Hybrids by Bruce Anderson, Department of Agronomy and Horticulture, UNL

CGS 2001 Seminar Series


Statistical Inference For Simultaneous Clustering Of Gene Expression Data, Katherine S. Pollard, Mark J. Van Der Laan Jul 2001

Statistical Inference For Simultaneous Clustering Of Gene Expression Data, Katherine S. Pollard, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Current methods for analysis of gene expression data are mostly based on clustering and classification of either genes or samples. We offer support for the idea that more complex patterns can be identified in the data if genes and samples are considered simultaneously. We formalize the approach and propose a statistical framework for two-way clustering. A simultaneous clustering parameter is defined as a function of the true data generating distribution, and an estimate is obtained by applying this function to the empirical distribution. We illustrate that a wide range of clustering procedures, including generalized hierarchical methods, can be defined as …


Acer Saccharum Marshall, John E. Ebinger Jul 2001

Acer Saccharum Marshall, John E. Ebinger

Specimens by Name

No abstract provided.


Flowering Plants: Pokeweeds, Four-O’Clocks, Carpetweeds, Cacti, Purslanes, Goosefoots, Pigweeds, And Pinks, Robert H. Mohlenbrock Jul 2001

Flowering Plants: Pokeweeds, Four-O’Clocks, Carpetweeds, Cacti, Purslanes, Goosefoots, Pigweeds, And Pinks, Robert H. Mohlenbrock

Illustrated Flora of Illinois

Robert H. Mohlenbrock provides a definitive account of the pokeweed, four-o'clock, carpetweed, cactus, purslane, goosefoot, pigweed, and pink families in Illinois.

Flowering Plants: Pokeweeds, Four-o’clocks, Carpetweeds, Cacti, Purslanes, Goosefoots, Pigweeds, and Pinks is the fifteenth volume of the Illustrated Flora of Illinois series and the ninth devoted to dicots, or plants that have two seed-leaves, or cotyledons, upon germination. Each of the 141 plants is beautifully illustrated by Paul W. Nelson.

Nelson shows the full habitat of the plant and close-ups of various vegetative and reproductive structures that are crucial for the identification of individual species. Each illustration includes detailed …


Groundwater Study Of The Wagin Townsite, Edward K. Crossley Jul 2001

Groundwater Study Of The Wagin Townsite, Edward K. Crossley

Resource management technical reports

A groundwater study was carried out for the townsite of Wagin with the aim of accelerating the implementation of effective salinity management options.


Verbena Urticifolia L., John E. Ebinger Jul 2001

Verbena Urticifolia L., John E. Ebinger

Specimens by Name

No abstract provided.


Acer Saccharum Marshall, John E. Ebinger Jul 2001

Acer Saccharum Marshall, John E. Ebinger

Specimens by Name

No abstract provided.


Biological Control As A Tool For Ecosystem Management, David H. Headrick, Richard D. Goeden Jul 2001

Biological Control As A Tool For Ecosystem Management, David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

Biological control is proposed as a tool useful for ecosystem management and compatible with the goals of often competing interests regarding the restoration and maintenance of ecosystems. We summarize the effects of introduced species on ecosystems in three broad groups: insects, vertebrates, and weeds. We then discuss the role of biological control for each of these groups in the context of ecosystem management and realistic outcomes. Of the three groups, we show that biological control of weeds appears to have the best chance for success in ecosystem management. We provide two case studies to support our ideas and finally discuss …