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Engineer Cantonment, Missouri Territory, 1819-1820: America's First Biodiversity Ineventory, Hugh H. Genoways, Brett C. Ratcliffe

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

It is our thesis that members of the Stephen Long Expedition of 1819-20 completed the first biodiversity inventory undertaken in the United States at their winter quarters, Engineer Cantonment, Missouri Territory, in the modern state of Nebraska. This accomplishment has been overlooked both by biologists and historians, but it should rank among the most significant accomplishments of the expedition. The results of this inventory allow us to evaluate the environmental, faunal, and floral changes along the Missouri River in the intervening nearly 190 years. The historical records form a visual image of a dynamic riverine system in which a highly …

Superior Adaptation To Drought In Rubus Armeniacus (Himalayan Blackberry) In Northwest Oregon, J. Alan Yeakley, Joshua S. Caplan

Environmental Science and Management Faculty Publications and Presentations

Despite the status Rubus armeniacus (Himalayan blackberry) has as one of the most prolific and damaging plant invaders in the Pacific Northwest, we know little about the role of water relations in its success. The information available on invasive blackberry water relations (Fotelli et al. 2001; McDowell and Turner 2002) suggests that an ability to avoid water stress has been critically important to their proliferation in regions with Mediterranean climates (Amor et al. 1998). We had two objectives regarding the role of water relations in the invasive success of R. armeniacus:

Objective 1. Determine if R. armeniacus is better adapted …

Ethylene Production As An Indicator Of Stress Conditions In Hydroponically-Grown Strawberries, Justin Donald Hogan

Theses, Dissertations and Capstones

With the worldwide phaseout of methyl bromide, the use of hydroponic systems has increased as an economic alternative for the growth of many horticulturally-important crops, including strawberries. In this study, the effect of hydroponics on strawberry plant physiology was examined by first measuring ethylene levels, a plant hormone known to increase due to stressful conditions, and plant growth and yield. Using a gas chromatograph, ethylene was measured from plants which showed that light and temperature have minimal effects, but placement of plants could have an effect on plant growth and yield. Next, the mechanism of ethylene production was examined by …

Packing Factors Of Feed Products In Storage Structures, Samuel G. Mcneill, Michael D. Montross, Sidney A. Thompson, I. Joseph Ross, Thomas C. Bridges

Biosystems and Agricultural Engineering Faculty Publications

Experiments were conducted to measure the changes in bulk density of cracked corn, corn meal, soybean meal, cotton seed meal, and distillers dried grain (without solubles) when subjected to simulated overburden pressures. All materials were tested at two moisture content levels (approximately 8% and 12% w.b.) and seven pressures between 0 and 69 kPa (0 and 10 psi). A mathematical model was fitted to the data to predict the bulk density of each feed ingredient as a function of pressure and moisture content. These relationships were inserted into a previously developed computer model to predict ingredient packing within conventional storage …

Arkansas Endemic Biota: An Update With Additions And Deletions, H. Robison, C. Mcallister, C. Carlton, G. Tucker

Journal of the Arkansas Academy of Science

It has been over a decade since the publication of Robison and Allen (1995) that provided the definitive list of endemic flora and fauna of Arkansas. The present study brings up-to-date the endemic biota of the state. Since 1995, several new species have been described and new discoveries have been made, adding species to the state biota. Other species are deleted and new distributional information on other state endemics is presented. Specifically, 3 new plant species are added to the state list while 4 plant species are deleted. Sixteen new animal species/subspecies are added to the state list while numerous …

In Planta Distribution Of ‘Candidatus Liberibacter Asiaticus’ As Revealed By Polymerase Chain Reaction (Pcr) And Real-Time Pcr, Satyanarayana Tatineni, Uma Shankar Sagaram, Siddarame Gowda, Cecile J. Robertson, William O. Dawson, Toru Iwanami, Nian Wang

Department of Plant Pathology: Faculty Publications

Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide, and is caused by a phloem-limited fastidious prokaryotic α- proteobacterium that is yet to be cultured. In this study, a combination of traditional polymerase chain reaction (PCR) and real-time PCR targeting the putative DNA polymerase and 16S rDNA sequence of ‘Candidatus Liberibacter asiaticus,’ respectively, were used to examine the distribution and movement of the HLB pathogen in the infected citrus tree. We found that ‘Ca. Liberibacter asiaticus’ was distributed in bark tissue, leaf midrib, roots, and different floral and fruit parts, but not in endosperm and …

Three Genes Of Citrus Tristeza Virus Are Dispensable For Infection And Movement Throughout Some Varieties Of Citrus Trees, Satyanarayana Tatineni, Cecile J. Robertson, Stephen M. Garnsey, Moshe Bar-Joseph, Siddarame Gowda, William O. Dawson

Department of Plant Pathology: Faculty Publications

Citrus tristeza virus (CTV), a member of the Closteroviridae, possesses a 19.3-kb positive-stranded RNA genome that is organized into twelve open reading frames (ORFs). The CTV genome contains two sets of conserved genes, which are characteristic of this virus group, the replication gene block (ORF 1a and 1b) and the quintuple gene block (p6, HSP70 h, p61, CPm, and CP). With the exception of the p6 gene, they are required for replication and virion assembly. CTV contains five additional genes, p33, p18, p13, p20 and p23, in the 3′ half of the genome, some of which (p33, p18 and …

Regulation Of Apical Dominance In Aspergillus Nidulans Hyphae By Reactive Oxygen Species, Camile P. Semighini, Steven D. Harris

Department of Plant Pathology: Faculty Publications

In fungal hyphae, apical dominance refers to the suppression of secondary polarity axes in the general vicinity of a growing hyphal tip. The mechanisms underlying apical dominance remain largely undefined, although calcium signaling may play a role. Here, we describe the localized accumulation of reactive oxygen species (ROS) in the apical region of Aspergillus nidulans hyphae. Our analysis of atmA (ATM) and prpA (PARP) mutants reveals a correlation between localized production of ROS and enforcement of apical dominance. We also provide evidence that NADPH oxidase (Nox) or related flavoproteins are responsible for the generation of ROS at hyphal tips and …

Myron Kendall Brakke: 1921 To 2007, Karen-Beth G. Scholthof, Andrew O. Jackson, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Plant pathology lost a distinguished pioneer in plant virology with the death of Dr. Myron K. Brakke on 15 June 2007. Those who were his close colleagues also lost a valued mentor, an irreplaceable friend, and a trusted adviser. Brakke’s most notable accomplishment was the development of sucrose density gradient centrifugation for the purification and characterization of viruses and macromolecules, which led to major advances in biochemistry and molecular biology. He also was responsible for introducing numerous techniques and equipment for fractionation of macromolecules that were crucial for the development of virology, biochemistry, and molecular biology. In the early stages …

An Immunofluorescence Assay To Detect Urediniospores Of Phakopsora Pachyrhizi, Fulya Baysal-Gurel, Melanie L. Lewis Ivey, Anne E. Dorrance, Douglas Luster, Reid Frederick, Jill Czarnecki, Michael J. Boehm, Sally A. Miller

Department of Plant Pathology: Faculty Publications

An indirect immunofluorescence spore assay (IFSA) was developed to detect urediniospores of Phakopsora pachyrhizi, utilizing rabbit polyclonal antisera produced in response to intact nongerminated (SBR1A) or germinated (SBR2) urediniospores of P. pachyrhizi. Both antisera were specific to Phakopsora spp. and did not react with other common soybean pathogens or healthy soybean leaf tissue in enzyme-linked immunosorbent assay (ELISA). SBR1A and SBR2 bound to P. pachyrhizi and P. meibomiae urediniospores were detected with goat anti-rabbit Alexa Fluor 488-tagged antiserum using a Leica DM IRB epifluorescent microscope with an I3 blue filter (excitation 450 to 490 nm, emission 515 nm). The …

The Effect Of Orientation To Growing Season Sunlight On Stomatal Parameters Of Q. Rubra In The Belgrade Lakes Region, Central Maine, Rachel G. Daly

Honors Theses

Stomatal frequencies of fossil-plant species are used to estimate past pCO2 levels based on the physiological functions of living taxa. Numerous studies have shown that there is an inverse relationship between pCO2 and stomatal frequency parameters. As levels of pCO2 increase, the Stomatal Density (SD) and Stomatal Index (SI) decrease. However, pCO2 is not the only factor affecting SD and SI values, which are a product of leaf growth and expansion. Stomatal characteristics differ between genera, and studies also have shown that SD and light intensity have a positive correlation. The present study hypothesizes that SD and SI are not …

The Pollination Biology And Mating System Of A Peripheral Population Of Witheringia Solanacea (Solanaceae), Timothy Miller

Honors Theses

Pollinator visitation rates over the life of a flower are determined by pollinator abundance and floral longevity. If flowers are not visited frequently enough, pollen limitation may occur, favoring the evolution of self-compatibility (SC). In plant species with varying SC levels, central populations often are self-incompatible (SI) and peripheral populations are SC. Witheringia solanacea (Solanaceae) is a species that follows this trend with the exception of one population in the Monteverde Cloud Forest Reserve, which is peripheral yet SI. I investigated this population using multiple techniques including floral bagging, pollinator observations, microsatellite analysis, and floral longevity manipulations. My results confirmed …

Spatial Structure And Inbreeding Depression In Slickspot Peppergrass, Lepidium Papilliferum (Brassicaceae), Stephanie A. Billinge, Ian C. Robertson

Biology Faculty Publications and Presentations

In plants with limited pollen and seed dispersal, populations are often spatially structured such that neighboring individuals are more closely related to one another than to distant individuals. Mating among close relatives, including selfing, may lead to a reduction in reproductive performance through the effects of prezygotic mating barriers and inbreeding depression. Studying 11 populations of slickspot peppergrass, Lepidium papilliferum (L.F. Hend.) A. Nels. and J.F. Macbr (Brassicaceae), a rare mustard endemic to southwestern Idaho, we investigated whether small populations (16–746 flowering individuals) exhibit spatial structure as previously reported for large populations (>3000 flowering individuals). Through hand-pollination experiments we …

Insertion Of The Enzyme Cyclopropane Fatty Acid Synthase Into Plastids Through Agrobacterium Mediated Transformation, Jason L. Rush

Undergraduate Honors Thesis Collection

Under natural conditions, Agrobacterium is a plant pathogen that infects plants by inserting genes into the plant's genome that are desirable to the bacterium itself. A tumor is then formed and the infected plant tissue makes molecules that the bacterium uses as food.

Investigation Of Kalanchoe Homeobox 1 (Kh1) Gene In Apical Meristems Of Kalanchoe Pinnatum, Jessica Lynn Kirkpatrick

Undergraduate Honors Thesis Collection

Kalanchoe pinnatum (syn. Bryophyllum pinnatum) is a succulent plant that is notable for developing small plantlets on the outer edges of its leaves, when its leaves are detached (Kulka 2006). These plantlets eventually drop off and root, which is a unique way for the plant to asexually reproduce. In most other plants, leaves exhibit determinate growth, meaning once they reach their maturity, they do not continue to grow.

Validation Case Study : Treatment Effectiveness In Aspen Vegetation Type : A Comparison Of Two Types Of Treatments On The Manti-La Sal National Forest, Diane M. Cote

Aspen Bibliography

No abstract provided.

Evaluation Of Different Insecticides And Fabric Types For Development Of Treated Targets For Stable Fly (Diptera: Muscidae) Control, Jerome Hogsette, Alyce Nalli, Lane Foil

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

Stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), once only a pest of pastured cattle, has become a serious pest of range cattle in the United States. Because of the difficulties associated with stable fly management under range conditions, a pesticide-impregnated cloth target is being developed as a management tool. We conducted studies to determine the influence of weather, time, fabric type, insecticide type, and insecticide concentration on the mortality of stable flies from a susceptible laboratory colony exposed for 30 s to treated cloth targets. We found that 100% of the flies exposed to trigger (Trigger-Royal Box, 65% polyester and …

Effect Of Lures And Trap Placement On Sand Fly And Mosquito Traps, Ulrich R. Bernier, David F. Hoel, Jerome Hogsette, Hanafi A. Hanafi, Daniel Kline

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

Catches of mosquitoes and sand flies in CO₂ traps baited with three different lures and an unbaited control were compared. The lures examined were carbon dioxide, carbon dioxide plus l-octen-3-ol, and carbon dioxide plus human hair in ethanol. Studies using a 4 x 4 Latin square design, with 3 sets of 4 consecutive trap nights, were conducted between August 6 and September 10, 2007. The study site was the Bahrif Village, Aswan, Egypt. This location had high percentage of Phlebotomus papatasi in sand fly populations, and the low incidence of human cases of leishmaniasis. There were 2,152 sand flies …

Managing And Enhancing Switchgrass As A Bioenergy Feedstock, Robert B. Mitchell, Kenneth Vogel

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

The United States Department of Energy (DOE) has identified switchgrass (Panicum virgatum L.) as a viable perennial herbaceous feedstock for cellulosic ethanol production. Although switchgrass bioenergy research was initiated by USDA-ARS, Lincoln, NE, USA in 1990, switchgrass research has been conducted at this location since the 1930s. Consequently, a significant amount of genetic and agronomic research on switchgrass has been conducted for the Corn Belt and Central Great Plains of the USA that is directly applicable to its use as a biomass energy crop. Similar research must be conducted in other major agroecoregions to verify or modify switchgrass management …

Effects Of Agricultural Conservation Practices On Fish And Wildlife Volume 2, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

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

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the United States Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

Interannual Variability In Carbon Dioxide Fluxes And Flux–Climate Relationships On Grazed And Ungrazed Northern Mixed-Grass Prairie, H. Wayne Polley, Albert B. Frank, Joaquin Sanabria, Rebecca L. Phillips

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

The annual carbon (C) budget of grasslands is highly dynamic, dependent on grazing history and on effects of interannual variability (IAV) in climate on carbon dioxide (CO₂) fluxes. Variability in climatic drivers may directly affect fluxes, but also may indirectly affect fluxes by altering the response of the biota to the environment, an effect termed ‘functional change’.

Effects Of Agricultural Conservation Practices On Fish And Wildlife, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

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

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

Environmental Management Of Grazing Lands Final Report, Kevin Wagner, Larry Redmon, Terry Gentry, Darren Harmel, Allan Jones

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

Bacteria levels are the number one cause of water quality impairment in Texas. Several recent Total Maximum Daily Loads (TMDLs) in Texas, such as those implemented in the Peach Creek and Leon River watersheds, have identified grazing cattle as a contributor to bacterial water quality impairments in those watersheds through both direct deposition and runoff of their fecal matter to streams. To address this issue, the Texas State Soil and Water Conservation Board (TSSWCB) and the Natural Resources Conservation Service (NRCS) funded this project to assist with development and delivery of technical information and support to ranchers on protection and …

Tillage Effects On Soil Quality Indicators And Nematode Abundance In Loessial Soil Under Long- Term No-Till Production, R. B. Mendoza, T. G. Franti, John W. Doran, Thomas O. Powers, C. W. Zanner

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

Soil quality indicators and nematode abundance were characterized in a loessial soil under long-term conservation tillage to evaluate the effects of no-till, double-disk, chisel, and moldboard plow treatments. Indicators included soil electrical conductivity (EC), soil texture, soil organic matter (SOM), and total particulate organic matter (tPOM). Nematode abundance was positively correlated with EC, silt content, and total POM and negatively correlated with clay content. Clay content was the main source of variation among soil quality indicators and was negatively correlated with nematode abundance and most indicators. The gain in SOM in the no-till system amounted to 10887 kg over the …

Characterization Of Biological Types Of Cattle: Indicator Traits Offertility In Beef Cows, R. A. Cushman, M. F. Allan, L. A. Kuehn

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

Genetic diversity among breeds of cattle allows producers to select animals for specific environments or market conditions. Reproductive efficiency is a multi-component trait that is largely influenced by environmental influences such as health and nutritional status; however, there are clearly genetic components to reproductive efficiency, and breed differences in a number of indicator traits associated with fertility and cow productivity have been identified. Historical indicators of fertility include scrotal circumference, age at puberty, and postpartum interval. Both age at puberty and postpartum interval are laborious traits to collect in heifers and cows because they require many days of detection of …

Chapter 8. The Importance And Role Of Watersheds In The Transport Of Nitrogen, T. J. Sauer, R. B. Alexander, J. V. Brahana, R. A. Smith

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

A recent report to Congress concerning water quality in the United States indicated that 35%, 45%,and 44'% of the assessed rivers and streams, lakes, and estuaries, respectively, were impaired by one or more pollutants (US Environmental Protection Agency, 1999). Nutrients, primarily nitrogen (N) and phosphorus (P), contributed to the impairment of 30% or 135,000 km of the nation's impaired rivers and streams. 44% of the impaired lakes, and 23% of the impaired estuaries. Excessive nutrient loads are implicated in the eutrophication of lakes and reservoirs in the United States and coastal ecosystems where N is most limiting to primary productivity …

Chapter 2. Transformation And Transport Processes Of Nitrogen In Agricultural Systems, Ronald Follett

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

This chapter discusses the transformation and transport processes of nitrogen (N) in agricultural systems and provides information on overall reservoir sizes for N. Nitrogen is ubiquitous in the environment and is required for the survival of all living things. It is also one of the most important essential nutrients and is central to the production of all crop plants. The most abundant form of N in the environment is elemental dinitrogen (N₂) gas that accounts for 78% of the atmosphere. N₂ gas is inert and is not directly available for plant uptake and metabolism. The atmospheric reservoir …

Chapter 7. Nitrogen In Groundwater Associated With Agricultural Systems, M. R. Burkartaus D, J. D. Stoner

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

Nitrogen, particularly in the form of nitrate, is the most common contaminant in aquifer systems (Freeze and Cherry, 1979). Hallberg (1989) points to agriculture as the most substantial anthropogenic source of nitrate, and Keeney (1986) suggests that this is caused by the intensive and extensive land-use activities associated with crops and animal production. The discussion of the occurrence of nitrogen in groundwater beneath agricultural systems is presented by examining the factors influencing aquifer vulnerability to nitrogen contamination, and by characterizing the geographic distribution of groundwater contamination by nitrogen. Factors that influence aquifer vulnerability are presented in the context of exposure …

Auditing And Assessing Air Quality In Concentrated Feeding Operations, N. A. Cole, R. Todd, B. Auvermann, D. B. Parker

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

The potential adverse effects of concentrated animal feeding operations (CAFO) on the environment are a growing concern. The air quality issues of most concern to CAFO vary but generally include ammonia, hydrogen sulfide, particulate matter, volatile organic compounds, greenhouse gases, and odors. Air pollutants may be regulated by federal and state laws or by nuisance complaints. The United States Environmental Protection Agency, and poultry, swine, and dairy industries recently agreed to the National Air Emissions Monitoring System to fund research on atmospheric emissions from production farms in the United States. Air quality regulations may be based on actual emissions, atmospheric …

Chapter 1. The Nitrogen Cycle, Historical Perspective, And Current And Potential Future Concerns, D. R. Keeney, J. L. Hatfield

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

Nitrogen (N) along with carbon and oxygen is the most complex and crucial of the elements essential for life. Supplementing grain and grass forage crops with organic and inorganic N fertilizers has long been recognized as a key to improving crop yields and economic returns. Globally. N fertilizer is largely used for cereal grain production and accounts for an estimated 40(1r of the increase in per capita food production in the past 50 years (Mosier et al.. 200 I). Smil (200 I) estimates that N fertilizer supplies up to 40% of the world's dietary protein and dependence on N from …