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Articles 1 - 11 of 11

Full-Text Articles in Life Sciences

The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke Dec 2014

The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke

Theses and Dissertations

In cotton production, nitrogen (N) is the most limiting nutrient and the demand is substantial. Foliar-N fertilization is regarded as an effective and environmentally sound method of supplying cotton with N during times of deficiency and high demand. In response to the potential benefits of the foliar-N fertilization of cotton, a myriad of foliar-N based fertilizers have been created; each with their own individual chemical technology and constitution. Experiments were performed with the objectives of examining the effects of the slow-release foliar-N fertilizer, Nitamin® (1) on the growth and development of field-grown cotton, (2) on uptake under various environmental conditions ...


Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs Dec 2014

Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs

Theses and Dissertations

Switchgrass (Panicum virgatum L.) has been identified as a model bioenergy feedstock crop and is expected to become an important feedstock for future renewable fuel generation. Agronomic management combinations that maximize monoculture switchgrass yield are generally well understood; however, little is known about corresponding effects of differing switchgrass management combinations on near-surface soil properties. The objective of this research was to determine the residual near-surface soil property effects of three years (2008 to 2011) of consistent management combinations to maximize switchgrass biomass production, including cultivar (‘Alamo’ and ‘Cave-in-Rock’), harvest frequency (1-cut and 2-cut systems per year), fertilizer source (poultry litter ...


Effects Of Large Scale Growing Season Prescribed Burns On Movement, Habitat Use, Productivity, And Survival Of Female Wild Turkey On The White Rock Ecosystem Restoration Project Of The Ozark-St. Francis National Forest, Henry Tyler Pittman Aug 2014

Effects Of Large Scale Growing Season Prescribed Burns On Movement, Habitat Use, Productivity, And Survival Of Female Wild Turkey On The White Rock Ecosystem Restoration Project Of The Ozark-St. Francis National Forest, Henry Tyler Pittman

Theses and Dissertations

Restoration of woodland and savanna ecosystems has become a common management strategy in the Central Hardwoods region. Over the past two decades forest managers have implemented woodland and savanna restoration at the landscape level (≥10,000 ha), especially using early growing season prescribed fire. The implementation of the restoration strategy has coincided with declines of Eastern Wild Turkey (Meleagris gallopavo silvestris) in many treated areas causing concern that early growing season prescribed fire was impacting wild turkey. We initiated our study to examine the effect of woodland and savanna restoration on the ecology and habitat of wild turkey in the ...


Evaluation Of Alternative Culling Strategies For Maintenance Of Genetic Variaton In Bison (Bison Bison), Rachael Marie Toldness Aug 2014

Evaluation Of Alternative Culling Strategies For Maintenance Of Genetic Variaton In Bison (Bison Bison), Rachael Marie Toldness

Theses and Dissertations

Bison (Bison bison) once numbered in the millions and roamed across much of the lower 48 states. By the late 1800s, overhunting had reduced the population to around 1,000 individuals. Strong efforts to establish managed herds have resulted in a steady bison population increase. Currently, six herds are maintained by the U.S. Fish and Wildlife Service (FWS) at National Wildlife Refuges (NWRs) and are intensively managed through annual culling to keep herd size at targeted levels. Although various criteria have historically been used to select individuals for culling, the FWS currently employs an allele frequency based strategy that ...


A Mixed Methods Approach Of Communication Campaign Development And Assessment: Identifying The Needs Of An Audience And Determining The Value In Evaluation, Tara Johnson Aug 2014

A Mixed Methods Approach Of Communication Campaign Development And Assessment: Identifying The Needs Of An Audience And Determining The Value In Evaluation, Tara Johnson

Theses and Dissertations

The two articles presented in this thesis used both quantitative and qualitative research methods to examine two distinct stages of communication campaigns: research and evaluation. In the quantitative study, students (n = 440) at the University of Arkansas were surveyed to determine their perceptions of the Arkansas Water Resources Center (AWRC), water resources, and water issues. A questionnaire was developed from an existing instrument, reviewed by a panel of experts, pilot tested, and revised. The researchers found participants were most aware (M = 3.23, SD = 1.14), concerned (M = 4.07, SD = 0.86), and interested (M = 4.10, SD = 0 ...


Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park May 2014

Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park

Theses and Dissertations

This dissertation investigates three important topics related to flowering phenology throughout the United States. First, this work evaluates the utility of herbarium records for estimating historical variation in community-level flowering phenology, and evaluate the relationship of such estimates to satellite-derived greenup timing at regional scales. This dissertation then reconstructs historical variations in flowering phenology throughout the spring, summer, and autumn across South Carolina for the years 1951 through 2009. These estimates will then be compared to seasonal temperature variations throughout this period. Finally, this dissertation develops novel herbarium-based methods to separate intraspecific phenological variations over space from changes in flowering ...


A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel May 2014

A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel

Theses and Dissertations

Bacterial growth in sand is of concern in regard to the health of beaches. A mathematical model is presented that represents the movement of moisture and the growth of bacteria through a beach. Simulations were run by numerically solving Richards Equation using a Finite Volume Method in order to track moisture movement. A model of moisture-dependent bacterial growth was then implemented. These simulations show that elevated bacteria counts following rain events do not necessarily result from bacteria in the body of water, but can also be sourced from the sand. Additionally, four different moisture-dependent bacterial growth models are compared to ...


Effects Of Petroleum Distillates On Amphibian Development, Kate Walker May 2014

Effects Of Petroleum Distillates On Amphibian Development, Kate Walker

Theses and Dissertations

Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators but little research has examined effects of petroleum distillates on aquatic species. I evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing. I selected three petroleum distillates (kerosene, oil, and unleaded gasoline) that are known to have negative effects on aquatic organisms and are similar to the common constituents of mixtures used ...


Identifying, Monitoring, Quantifying And Converting Algae To Bio-Fuels In Bio-Reactors, Alice C. Jernigan May 2014

Identifying, Monitoring, Quantifying And Converting Algae To Bio-Fuels In Bio-Reactors, Alice C. Jernigan

Theses and Dissertations

Growing algae as a source for bio-fuels has become an area of interest due to concerns about global warming and the reliability and ecology of the production of fossil fuels. Dried algae harvested from a pilot water quality improvement technology at the Rockaway Wastewater Treatment Facility in New York were examined as a source of carbohydrates and lipids for the production of bio-fuels in bio-reactors. The length of storage time, storage conditions, sugar and lipid extraction processes, and fuel production were studied. The results show that if the algae is stored dry (0.015 g/g algae even after a ...


Using Deuterium And Garp To Estimate Geographic Extents Of Source Populations Of Hoary (Lasiurus Cinereus) And Eastern Red (Lasiurus Borealis) Bats Killed At A Central Illinois Wind Facility, Rachael Anne Van Essen Apr 2014

Using Deuterium And Garp To Estimate Geographic Extents Of Source Populations Of Hoary (Lasiurus Cinereus) And Eastern Red (Lasiurus Borealis) Bats Killed At A Central Illinois Wind Facility, Rachael Anne Van Essen

Theses and Dissertations

High bat mortality at wind energy facilities is a widely cited conservation issue, but the population-level impacts are not understood. In Illinois, the main species affected are migratory tree bats like the Hoary (Lasiurus cinereus) and Eastern Red (Lasiurus borealis).This research used deuterium isotope analysis of hair combined with ecological niche modeling (GARP: Genetic Algorithm for Rule-set Prediction) in a novel way to map the geographic extents of Hoary and Eastern Red bat specimens salvaged at a single central Illinois wind facility from 2008-2010. Hair was chosen after determining that the claw is currently a problematic tissue due to ...


"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch Jan 2014

"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch

Theses and Dissertations

Quarterly samples were used to estimate assemblage-level (all species combined) fish production within three minimally-impacted, southern West Virginia streams. The total annual fish production estimate was highest in Slaunch Fork (37.52 kg∙ha-1∙y-1), a tributary of the Tug Fork River, and lowest in Cabin Creek (10.59 kg∙ha-1∙y-1), a Guyandotte River tributary. Creek Chub Semotilus atromaculatus, Mottled Sculpin Cottus bairdii and Blacknose Dace Rhinicthys atratulus were the most abundant species among sites, accounting for >90% of all sampled individuals. Reference condition criteria were also selected and metrics calculated for each of the ...