Physical Sciences and Mathematics Commons^™

Compartmentalization Of Prion Isoforms Within The Reproductive Tract Of The Ram, Heath W. Ecroyd, Pierre Sarradin, Jean-Louis Dacheux, Jean-Luc Gatti

Heath Ecroyd

Cellular prion protein (Prp(C)) is a glycoprotein usually associated with membranes via its glycosylphosphatidylinositol (GPI) anchor. The trans-conformational form of this protein (Prp(SC)) is the suggested agent responsible for transmissible neurodegenerative spongiform encephalopathies. This protein has been shown on sperm and in the reproductive fluids of males. Antibodies directed against the C-terminal sequence near the GPI-anchor site, an N-terminal sequence, and against the whole protein showed that the Prp isoforms were compartmentalized within the reproductive tract of the ram. Immunoblotting with the three antibodies showed that the complete protein and both N- and C-terminally truncated and glycosylated isoforms are present …

Post-Testicular Sperm Environment And Fertility, Jean-Luc Gatti, Sandrine Castella, Francoise Dacheux, Heath Ecroyd, S Metayer, Veronique Thimon, Jean-Louis Dacheux

Heath Ecroyd

When mammalian spermatozoa exit the testis, they show a highly specialized morphology; however, they are not yet able to carry out their task: to fertilize an oocyte. This property, that includes the acquisition of motility and the ability to recognize and to fuse with the oocyte investments, is gained only after a transit through the epididymis during which the spermatozoa from the testis travel to the vas deferens. The exact molecular mechanisms that turn these cells into fertile gametes still remain mysterious, but surface-modifying events occurring in response to the external media are key steps in this process. Our laboratory …

Protective Interactions Of Dairy Peptides With Fibril Structures And Relevance To Alzheimer's Disease, Louise Bennett, Williams Roderick, Heath Ecroyd, Yanqin Liu, Sunanda Sudharmarajan, John Carver

Heath Ecroyd

Selected dairy caseins have been shown to have capacity for chaperone-like regulation of folding pathways of other caseins, specifically in preventing development of fibrillar aggregates of beta sheet structure. An assay based on fibril formation by reduced and carboxymethylated-kappa casein (RCM-kCn) was thus used to screen for anti-fibril activity among a selection of dairy protein hydrolysates, in order to discover peptides with possible anti-fibril, chaperone activity. From the selection of eight dairy hydrolysates based on different dairy protein fractions, two of the hydrolysates of whey protein exhibited superior anti-fibril bioactivity against RCM-kCn and amyloid beta (Aβ), the peptide associated with …

Small Heat-Shock Proteins Interact With A Flanking Domain To Suppress Polyglutamine Aggregation, Amy L. Roberston, Stephen J. Headey, Helen M. Saunders, Heath Ecroyd, Martin J. Scanlon, John A. Carver, Stephen P. Bottomley

Heath Ecroyd

Small heat-shock proteins (sHsps) are molecular chaperones that play an important protective role against cellular protein misfolding by interacting with partially unfolded proteins on their off-folding pathway, preventing their aggregation. Polyglutamine (polyQ) repeat expansion leads to the formation of fibrillar protein aggregates and neuronal cell death in nine diseases, including Huntington disease and the spinocerebellar ataxias (SCAs). There is evidence that sHsps have a role in suppression of polyQ-induced neurodegeneration; for example, the sHsp alphaB-crystallin (αB-c) has been identified as a suppressor of SCA3 toxicity in a Drosophila model. However, the molecular mechanism for this suppression is unknown. In this …

Testicular Descent, Sperm Maturation And Capacitation. Lessons From Our Most Distant Relatives, The Monotremes, Russell Jones, Heath Ecroyd, Jean-Louis Dacheux, Brett Nixon

Heath Ecroyd

The present review examines whether monotremes may help to resolve three questions relating to sperm production in mammals: why the testes descend into a scrotum in most mammals, why spermatozoa are infertile when they leave the testes and require a period of maturation in the specific milieu provided by the epididymides, and why ejaculated spermatozoa cannot immediately fertilise an ovum until they undergo capacitation within the female reproductive tract. Comparisons of monotremes with other mammals indicate that there is a need for considerable work on monotremes. It is hypothesised that testicular descent should be related to epididymal differentiation. Spermatozoa and …

The Development Of Signal Transduction Pathways During Epididymal Maturation Is Calcium Dependent, Heath W. Ecroyd, Kelly Asquith, Russell C. Jones, Robert J. Aitken

Heath Ecroyd

Capacitation has been correlated with the activation of a cAMP-PKA-dependent signaling pathway leading to protein tyrosine phosphorylation. The ability to exhibit this response to cAMP matures during epididymal maturation in concert with the ability of the sperrnatozoa to capacitate. In this study, we have addressed the mechanisms by which spermatozoa gain the potential to activate this signaling pathway during epididymal maturation. In a modified Tyrode's medium containing 1.7 mM calcium, caput spermatozoa had significantly higher [Ca2+](i) than caudal cells and could not tyrosine phosphorylate in response to cAMP. However, in calcium-depleted medium both caput and caudal cells could exhibit a …

The Interaction Of Alphab-Crystallin With Mature Alpha-Synuclein Amyloid Fibrils Inhibits Their Elongation, Christopher A. Waudby, Tuomas P. J Knowles, Glyn L. Devlin, Jeremy N. Skepper, Heath Ecroyd, John A. Carver, Mark E. Welland, John Christodoulou, Christopher M. Dobson, Sarah Meehan

Heath Ecroyd

alphaB-Crystallin is a small heat-shock protein (sHsp) that is colocalized with alpha-synuclein (alphaSyn) in Lewy bodies—the pathological hallmarks of Parkinson's disease—and is an inhibitor of alphaSyn amyloid fibril formation in an ATP-independent manner in vitro. We have investigated the mechanism underlying the inhibitory action of sHsps, and here we establish, by means of a variety of biophysical techniques including immunogold labeling and nuclear magnetic resonance spectroscopy, that alphaB-crystallin interacts with alphaSyn, binding along the length of mature amyloid fibrils. By measurement of seeded fibril elongation kinetics, both in solution and on a surface using a quartz crystal microbalance, this binding …

Global Effects Of Climate Change On Wildfire: Causal Relationships Of Fire, The Natural Environment And Human Activities, Lindon N. Pronto

Lindon N Pronto

Climate change and human activity is significantly impacting the frequency and severity of wildfires across the globe. Although climate change and human population are the overarching factors affecting wildfires in the current dialogue, the issues are more complex and often not fully understood. These issues range from global temperature increases and severe drought cycles to the relatively new phenomenon of the wildland urban interface (WUI). This is the area where structures are integrated with or immediately surrounded by areas of moderate to high fire risk and are directly linked to fuel types and topographic features. Because climate change is such …

Global Change, Global Trade, And The Next Wave Of Plant Invasions, Bethany A. Bradley, Dana M. Blumenthal, Regan Early, Edwin D. Grosholz, Joshua J. Lawler, Luke P. Miller, Cascade J.B. Sorte, Carla M. D'Antonio, Jeffrey M. Diez, Jeffrey S. Dukes, Ines Ibanez, Julian D. Olden

Faculty Publications, Biological Sciences

Many non-native plants in the US have become problematic invaders of native and managed ecosystems, but a new generation of invasive species may be at our doorstep. Here, we review trends in the horticultural trade and invasion patterns of previously introduced species and show that novel species introductions from emerging horticultural trade partners are likely to rapidly increase invasion risk. At the same time, climate change and water restrictions are increasing demand for new types of species adapted to warm and dry environments. This confluence of forces could expose the US to a range of new invasive species, including many …

A Study Of Correlations Between The Definition And Application Of The Gene Ontology, Yuji Mo

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

When using the Gene Ontology (GO), nucleotide and amino acid sequences are annotated by terms in a structured and controlled vocabulary organized into relational graphs. The usage of the vocabulary (GO terms) in the annotation of these sequences may diverge from the relations defined in the ontology. We measure the consistency of the use of GO terms by comparing GO's defined structure to the terms' application. To do this, we first use synthetic data with different characteristics to understand how these characteristics influence the correlation values determined by various similarity measures. Using these results as a baseline, we found that …

Abiotic Stress Responses In Photosynthetic Organisms, Joseph Msanne

School of Natural Resources: Dissertations, Theses, and Student Research

Cellular and molecular aspects of abiotic stress responses in Arabidopsis thaliana subjected to cold, drought, and high salinity and in two photosynthetic green alga, Chlamydomonas reinhardtii and Coccomyxa sp. C-169, subjected to nitrogen deprivation were investigated. Cold, drought, and high salinity can negatively affect plant growth and crop production. The first research aimed at determining the physiological functions of the stress-responsive Arabidopsis thaliana RD29A and RD29B genes. Cold, drought, and salt induced both genes; the promoter of RD29Awas found to be more responsive to drought and cold stresses, whereas the promoter of RD29B was highly responsive to salt stress. …

Review Of Teaching Children Science: Hands-On Nature Study In North America, 1890-1930 By Sally Kohlstedt, Meena M. Balgopal

The Prairie Naturalist

Many scientists and educators agree that the goal of science education is to prepare students "to know, use and interpret scientific explanations of the natural world," as cited in the National Research Council publication, Taking Science to School: Learning and Teaching Science in Grades K-8 (DuschI et al. 2007). Yet, many science instructors of K-12 and post-secondary students often rely on teacher-telling modes of pedagogy and neglect to engage their students in natural inquiry and scientific study that model the research methods used by scientists. As a result, many young people are not aware of how scientists make discoveries about …

Genetic Structure Of Grass Carp Populations In The Missouri And Mississippi River Basins, Usa, Bobbi M. Adams, Katie N. Bertrand, Michael L. Brown, Donald Auger

The Prairie Naturalist

We provided an early characterization of the genetic structure of the grass carp (Ctenopharyngodon idella) population as it expands its distribution in both the Missouri and Mississippi River basins. Further, we provided initial comparisons of allelic richness at 17 polymorphic microsatellite markers between 56 grass carp from the USA, and six from the Yangtze River in China. The number of alleles per locus ranged from two to eight and size ranges of alleles for fish collected from the invaded and native ranges were similar (P ≤ 0.001; 107–226 bp) to those previously reported in the literature. Distance-based clustering …

Late Seasonal Captures Of The Plains Pocket Mouse (Perognathus Flavescens) In Iowa, Hans W. Otto, Jeremy A. White

The Prairie Naturalist

The plains pocket mouse, Perognathus flavescens, is a nocturnal granivore that inhabits friable soils in sparsely vegetated areas (Monk and Jones 1996). In the United States, the distribution of the plains pocket mouse extends from Arizona, New Mexico, and Texas through the Great Plains to North Dakota and Minnesota (Hall 1981). This species reaches its easternmost limits in Iowa, where it has been documented from a limited number of grassland sites in eastern, central, and western parts of the state (Bowles 1975, Wilson et al. 1996). Due to loss of grassland habitat, the plains pocket mouse is currently listed …

Modeling Parental Provisioning By Red-Winged Blackbirds In North Dakota, George M. Linz, Richard S. Sawin, Mark W. Lutman, William J. Bleier

The Prairie Naturalist

Male red-winged blackbirds (Agelaius phoeniceus) exhibit a difference in nest provisioning rates along an east-west gradient in North America. North Dakota is located in the center of North America and harbors a large population of breeding red-winged blackbirds (RWBL). This location provided an opportunity to compare provisioning rates in the central U.S. with those reported for the eastern and western populations. We placed video cameras at RWBL nests to record male and female feeding trips. Thirty-four nests were located on territories with original males and 30 were on territories where a replacement (floater) male had taken over a …

Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands\ By Paul Johnsgard, Jane Austin

The Prairie Naturalist

Paul Johnsgard has long been captivated by wild cranes and their unique vocalizations, courtship dances, and wide-ranging migrations. As a scientist and an admirer, Johnsgard has watched their migrations and behaviors for decades as hundreds of thousands of cranes staged each spring by the central Platte River, not far from his home in Lincoln, Nebraska. As an artist, he has skillfully captured their courtship dances and other behaviors in his exceptional line drawings. And, as an author, he has written extensively on their ecology in three earlier books: Cranes of the World (1983), Those of the Gray Wind: The Sandhill …

Massasauga Repatriation On A Restored Wet Prairie, Francis E. Durbian, Brian N. Lomas, Jeff Briggler, Paul Mckenzie, Tom Nagel

The Prairie Naturalist

The massasauga (Sistrurus catenatus) is a small rattlesnake that occurs from Texas to New York (Schmidt and Davis 1941, Conant and Collins 1991, Szymanski 1998). In Missouri, the Eastern massasauga rattlesnake (EMR; S. c. catenatus), a subspecies of the massasauga, occurs north and east of the Missouri River, is a former candidate for listing under the United States Endangered Species Act (Code of Federal Regulations 64 FR 57534; Szymanski 1998), and is listed as a state endangered species (Missouri Natural Heritage Program 2011). Missouri currently harbors five extant EMR populations (Johnson 2000, Durbian et al., unpublished report, …

Book Review Of Encyclopedia Of Biological Invasions, Edited By Daniel Simberloff And Marcel Rejmanek, Qinfeng Guo

The Prairie Naturalist

Book review of Encyclopedia of Biological Invasions, edited by Daniel Simberloff and Marcel Rejmanek.

Species introductions and consequent biotic invasions and homogenization are major components of global change that are drawing increasing concern and various levels of actions and reactions around the world. Invasion ecology has advanced rapidly during the last few decades, and the discipline is now increasingly integrated with the social and economic sciences. A better understanding of the invasion process and its effects is thus clearly needed. For basic research, invasion biology offers fascinating and sometimes unique opportunities for testing certain ecological or evolutionary theories and …

Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen

The Prairie Naturalist

Book review of Effects of Climate Change on Birds, edited by Anders Pape Meller, Wolfgang Fiedler, and Peter Berthold.

Climate scientists from across the globe predict vast changes during the next century in the planet's temperatures, precipitation, storm intensities, fire regimes, hydrologic cycles, and atmospheric, water, and soil chemistries. The changes will be global, but their effects will be felt locally everywhere. To find a scientifically and socially engaging bellwether of these events, we need to look only through the lens of avian biology. Birds are found from pole to pole; their movements connect continents. They are loud, colorful …

Northern Harrier Hatches Mallard Nest, Jeffery W. Stackhouse, Benjamin A. Geaumont

The Prairie Naturalist

The northern harrier (Circus cyaneus) is a widespread raptor commonly found nesting throughout the Northern Great Plains. Northern harriers forage primarily on small mammals and passerines with the males providing the majority of prey to nestlings until 14–28 days of age (Redpath et al. 2006, Vukovich and Ritchison 2006). Although the genus Circus is known to predate eggs from nest of many nesting birds (Hiraldo et al. 1975, Donaszar et al. 1996, Opermanis et al. 2000), few have been recorded commandeering nests of different species (Laine 1928, Fleskes 1992). In June 2010, we observed a northern harrier that …

Comparison Of Fish Communities In Recently Constructed Side-Channel Chutes With The Main Stem Missouri River, Kasey Whiteman, Vincent H. Travnichek, Darrick L. Garner, Brandon Eder, Kirk Steffensen

The Prairie Naturalist

Two United States Army Corp of Engineers- (USACE) funded projects were conducted from 2006 to 2008 along the Missouri River to monitor fish communities in recently constructed side-channel chutes and to monitor pallid sturgeon (Scaphirhynchus albus) and the associated fish assemblage in the main stem Missouri River. Data from both monitoring projects were compared to evaluate fish assemblages among four mitigated habitats (e.g., constructed side-channel chutes) and the main-stem Missouri River. Chutes had a greater overall number of species (n = 59) and higher species richness (Margalef’s index = 5.81), but richness was not different (F1, 4 = …

Notes On The Distribution Of Eastern Woodrats And Hispid Cotton Rats In South-Central Nebraska, Heather D. Wills, Keith Geluso, Eric J. Smits, Joseph T. Springer, Wesley E. Newton

The Prairie Naturalist

The eastern woodrat (Neotoma floridana) and hispid cotton rat (Sigmodon hispidus) reach distributional limits in southern Nebraska (Jones 1964, Farney 1975). In the last half-century, both species have expanded their distributional ranges in the region (Kugler and Geluso 2009, Wright et al. 2010). Herein, we report new localities of occurrence for both species that extend known distributional boundaries in south-central Nebraska beyond those reported by Kugler and Geluso (2009) and Wright et al. (2010).

Associated with other studies, we captured small mammals in Sherman live-traps in south-central Nebraska. Voucher specimens were deposited in collections at the …

Climate Change And Climate Variability: El Salvador – Impacts On Productivity Of Grain Crops And Opportunities For Management And Improvement, P. V. Vara Prasad

INTSORMIL Presentations

1. Climate change and climate variability (past and future).

2. Climate change and variability in El Salvador (climate models).

3. Impact of temperature on grain yield of dry bean, maize and sorghum in El Salvador (crop simulation models).

4. Effects of temperature, drought and/or carbon dioxide: experimental evidence (response of grain sorghum, maize and dry bean).

5. Opportunities for crop management and genetic improvement.

An Evaluation Of Disturbance-Induced Nutrient Changes And Climate Responses Of Loblolly Pine Xylem, Rebecca Lynne Stratton

Doctoral Dissertations

Dendrochronological techniques are currently limited to the identification of visible fire scars. However, through the development of new dendrochemical techniques, the potential exists to provide insight into a broader array of pyric ecosystems. In addition, the ability to identify historic climate-growth responses provides a better understanding of the conditions under which historic fire regimes occurred.

This study provides the groundwork for the identification of a dendrochemical nutrient fire signature in xylem and identifies the climate-radial growth responses of loblolly pine (Pinus taeda L.) on five sites in the Piedmont of South Carolina. Changes in N, P, K, Ca, Mg, …

Development And Application Of Liquid Chromatography-Tandem Mass Spectrometry Methods To The Understanding Of Metabolism And Cell-Cell Signaling In Several Biological Systems, Jessica Renee Gooding

Doctoral Dissertations

Liquid chromatography tandem mass spectrometry has become a powerful tool for investigating biological systems. Herein we describe the development of both isotope dilution mass spectrometry methods and targeted metabolomics methods for the study of metabolic and cell-cell signaling applications.

A putative yeast enzyme was characterized by discovery metabolite profiling, kinetic flux profiling, transcriptomics and structural biology. These experiments demonstrated that the enzyme shb17 was a sedoheptulose bisphosphatase that provides a thermodynamically dedicated step towards riboneogenesis, leading to the redefinition of the canonical pentose phosphate pathway.

An extension of metabolic profiling and kinetic flux profiling methods was developed for a set …

Synthesis Of An Antimicrobial Textile Coating, William M. Morris

Chemistry and Biochemistry

A titania nanosol was synthesized and coated onto nylon/cotton blended textile substrates. The substrates were characterized via SEM for adhesion and nanoparticle formation, then subjected to antimicrobial efficacy tests. The titania nanosol was successfully coated on to textiles samples. Particles were observed to be around 2 by 3 micrometers and formed between the interstitial space of textile fibers. Although larger than typical nanoparticles, the coatings exhibited what seemed to be antimicrobial activity. Titania nanosol coated textile samples were subjected to Kirby Bauer Assay in the presence of S. aureus. The coated textile sample exhibited an inhibition of growth around its …

Model Comparisons For Estimating Carbon Emissions From North American Wildland Fire, Nancy H. F. French, Willam J. De Groot, Liza K. Jenkins, Brendan M. Rogers, Ernesto Alvarado, Brian Amiro, Bernardus De Jong, Scott Goetz, Elizabeth Hoy, Edward Hyer, Robert Keane, B. E. Law, Donald Mckenzie, Steven G. Mcnulty, Roger Ottmar, Diego R. Perez-Salicrup, James Randerson, Kevin M. Robertson, Merritt Turetsky

Michigan Tech Research Institute Publications

Research activities focused on estimating the direct emissions of carbon from wildland fires across North America are reviewed as part of the North American Carbon Program disturbance synthesis. A comparison of methods to estimate the loss of carbon from the terrestrial biosphere to the atmosphere from wildland fires is presented. Published studies on emissions from recent and historic time periods and five specific cases are summarized, and new emissions estimates are made using contemporary methods for a set of specific fire events. Results from as many as six terrestrial models are compared. We find that methods generally produce similar results …

Emergent Behavior In A Coupled Economic And Coastline Model For Beach Nourishment, Eli D. Lazarus, D E. Mcnamara, M D. Smith, S Gopalakrishnan, A B. Murray

Publications

Developed coastal areas often exhibit a strong systemic coupling between shoreline dynamics and economic dynamics. "Beach nourishment", a common erosion-control practice, involves mechanically depositing sediment from outside the local littoral system onto an actively eroding shoreline to alter shoreline morphology. Natural sediment-transport processes quickly rework the newly engineered beach, causing further changes to the shoreline that in turn affect subsequent beach-nourishment decisions. To the limited extent that this landscape/economic coupling has been considered, evidence suggests that towns tend to employ spatially myopic economic strategies under which individual towns make isolated decisions that do not account for their neighbors. What happens …

Minerva 2011, The Honors College

Minerva

This issue of Minerva includes an article on four newly-hired Honors preceptors, Rob Glover, Sarah Harlan-Haughey, Jordan LaBouff, and Justin Martin; a feature on Honors award, scholarship, and fellowship winners; and an article on the Honors College collaboration with the IDeA Network of Biomedical Research Infrastructure (INBRE) National Genomics Research Initiative.

Groundwater Chemistry Of The Weaber Plain: Preliminary Results, Adam Lillicrap, Paul Raper, Richard J. George Dr, D L. Bennett

Resource management technical reports

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain. Construction of the M2 supply channel connecting the ORIA and the Weaber Plain, and the final period of irrigation design, environmental management and related approval processes, commenced later in 2009. This process followed a protracted period of public and private industry planning and environmental assessment (Kinhill 2000). This report summarises an analysis of groundwater salinity trends on the Ivanhoe and Weaber plains and the preliminary results of an intensive water-quality sampling program carried out in 2010 as part …