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Full-Text Articles in Life Sciences

Response Of Breeding Birds To Forest Disturbance In The Arkansas Ozarks: Impacts Of Uneven-Aged Management, Ice Damage, And Woodland Restoration, Maureen Mcclung May 2013

Response Of Breeding Birds To Forest Disturbance In The Arkansas Ozarks: Impacts Of Uneven-Aged Management, Ice Damage, And Woodland Restoration, Maureen Mcclung

Graduate Theses and Dissertations

Forests of the Ozarks are important breeding grounds for many bird species, each with specific habitat requirements. Natural and anthropogenic disturbance events can alter vegetational structure of forests, thereby influencing communities of breeding birds. The objectives of my study were to examine the response of breeding birds and their habitat to three types of forest disturbance: (1) uneven-aged management, (2) ice damage, and (3) woodland restoration. Avian and vegetation surveys were conducted during the 2008, 2009, and 2010 breeding seasons (May-June) in the Ozark National Forest, Arkansas. Each site was surveyed for birds four times a season using fixed-radius point …


Local Food And Agriculture Awareness: The Literacy Of Local Produce And Agriculture In Northwest Arkansas, Kyle Colton Flynn May 2013

Local Food And Agriculture Awareness: The Literacy Of Local Produce And Agriculture In Northwest Arkansas, Kyle Colton Flynn

Graduate Theses and Dissertations

The Center for Disease Control and Prevention (CDC) suggests that adolescents and children, both male and female, are failing to meet the daily fruit and vegetable consumption requirements (Kim et al., 2011; Upton et al., 2012; Harris et al., 2012). Other studies have shown that with increased exposure and availability of produce, students (K-5) tend to consume more fruits and vegetables (Cullen et al., 2009; Evans et al., 2012). The purpose of this study is to identify whether Northwest Arkansas eleventh grade high school students possess experience and knowledge of local produce and agriculture. Out of 1054 students enrolled at …


Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays May 2013

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Graduate Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …


An Analysis Of Firearms Training Performance Among Active Law Enforcement Officers, John Thomasson May 2013

An Analysis Of Firearms Training Performance Among Active Law Enforcement Officers, John Thomasson

Graduate Theses and Dissertations

Firearms proficiency is an implicit expectation, held by the public of police officers, due to presumption that the required firearm training is an adequate preparation for a deadly force encounter. However, anecdotal evidence and available data on police shootings suggest that conventional, unrealistic training methods are wholly inadequate. To present stress into firearms training, some departments have opted for exercises such as physical exertion and shoot-house training as a substitute for realistic simulation of force-on-force confrontations.

To determine whether such exercises are comparable, an observation of performance and heart rate levels was conducted on a group of eight police officers, …


Dynamics And Model Of The Pore-Forming Protein Lysenin, Eric Krueger May 2013

Dynamics And Model Of The Pore-Forming Protein Lysenin, Eric Krueger

Graduate Theses and Dissertations

Membrane transporters are a class of membrane proteins that function to provide a pathway across a cell membrane for the movement of ions and biomolecules. Investigations into the regulatory mechanism of these systems are hindered by their extensive preparation requirements compounded by their fragility and instability. However, lysenin, a pore-forming protein extracted from the earthworm Eisenia foetida, provided a unique opportunity to study a protein which is stable in both a soluble and membrane phase. Lysenin channels possess several important properties characteristic of ion channels without the inherent difficulties that plague investigations with biologically vital membrane transporters like voltage-gated ion …


Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott May 2013

Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott

Graduate Theses and Dissertations

Anthropogenic enrichment of nitrogen and phosphorus is one of the most pervasive and detrimental threats to aquatic ecosystems worldwide. In streams that rely on allochthonous basal food resources, such as leaves, nutrient pollution can result in altered food quality and decreased carbon (C) standing stocks. However, the magnitude and mechanisms of this change in quality are poorly understood. Laboratory microcosm studies were conducted to 1) quantify the response of litter C:P to a gradient of phosphorus (P) enrichment (0, 0.05, and 0.5 mg SRP/L) across leaf species with variable levels of degradability (sugar maple and oak), and 2) quantify the …


Effects Of Using Canola Meal As A Protein Source In Broiler Diets, Charles Danny Bradley Jr May 2013

Effects Of Using Canola Meal As A Protein Source In Broiler Diets, Charles Danny Bradley Jr

Graduate Theses and Dissertations

Six experiments were conducted to evaluate the response of broilers fed canola meal. Experiment 1 assessed performance and carcass yields when broilers were fed various combinations of canola and soybean meal in nutritionally balanced diets based on digestible amino acid values. The results suggested that canola meal can be used in isocaloric diets as a partial replacement for Soybean meal.

Experiment 2 assessed broiler performance and carcass yields when using various levels of canola meal in broiler diets with a constant level of supplemental poultry oil. The resulting data suggested when diets are formulated with a constant level of supplemental …


Development Of A Predictive Modeling System For Validation Of The Cumulative Mirobial Inactivation Of The Salmonellae In Pepperoni Utilizing A Non-Pathogenic Surrogate Microorganism (Enterococcus Faecalis), Scott Donald Stillwell May 2013

Development Of A Predictive Modeling System For Validation Of The Cumulative Mirobial Inactivation Of The Salmonellae In Pepperoni Utilizing A Non-Pathogenic Surrogate Microorganism (Enterococcus Faecalis), Scott Donald Stillwell

Graduate Theses and Dissertations

Salmonellosis is the most frequently occurring bacterial foodborne illness in the United States and the human case rate has not improved for the past two decades. The federal agency responsible for oversight of meat and poultry processors has announced the intent to extend existing pathogen reduction performance standards for Salmonella spp. to cover all classes of products including fermented sausages that are currently produced under HACCP plans that are validated for control of Escherichia coli O157:H7. The proposed regulatory modifications will require processors to revalidate HACCP plan controls to achieve either a 6.5 or a 7.0 log10 inactivation of the …


Physiological Effects Of Low Mowing Heights, Rolling, And Foot Traffic On Creeping Bentgrass Putting Greens, Joseph Ronald Young May 2013

Physiological Effects Of Low Mowing Heights, Rolling, And Foot Traffic On Creeping Bentgrass Putting Greens, Joseph Ronald Young

Graduate Theses and Dissertations

Golf course superintendents are managing creeping bentgrass (Agrostis stolonifera L.) putting greens throughout the transition zone where temperatures can exceed optimum levels for consecutive days in the summer. The stress of creeping bentgrass associated with these supraoptimal temperatures has been well documented, but the management practices implemented on putting greens to increase green speeds may exacerbate these environmental stresses. To date, the physiological effects of these management practices in combination have not been evaluated for putting green turf. The objective of this dissertation project was to determine the effect of mowing heights, light-weight rolling, and foot traffic on performance and …


Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons May 2013

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …


Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith May 2013

Modeling Greenhouse Gas Emissions And Net Return Implications For Cow-Calf Producers In The Ozark Highlands, Stephen Aaron Smith

Graduate Theses and Dissertations

Cow-calf producers in the Ozark Highlands region are under continuous pressure to improve economic efficiency. Additionally, estimating greenhouse gas (GHG) emissions from cow-calf and forage production processes may become increasingly important as policy makers seek to mitigate or reduce agriculture's role in climate change. As such, this analysis had three objectives. Objective 1: Provide a model that could be used by cow-calf producers, extension agents, and researchers to evaluate GHG and net return (NR) repercussions when modifying site characteristics, production methods, and inputs. Objective 2: Develop a user guide such that the methodology for estimating cow-calf GHG emissions and NR …


Genetic Structure Of The Copperhead (Viperidae: Agkistrodon Contortrix Mokasen) At Its Most Northern Distribution, Brenna Aaren Levine May 2013

Genetic Structure Of The Copperhead (Viperidae: Agkistrodon Contortrix Mokasen) At Its Most Northern Distribution, Brenna Aaren Levine

Graduate Theses and Dissertations

The focus of molecular studies in North American pitvipers has been on species that warrant conservation concern, such as Timber (Crotalus horridus) and Massasauga rattlesnakes (Sistrurus catenatus). Scant effort has been directed towards the molecular ecology of the Copperhead (Agkistrodon contortrix), other than to evaluate male reproduction in a laboratory setting and phylogenetic history. Thus, employing DNA-based molecular techniques to study the natural history of A. contortrix will broaden our knowledge of molecular ecology in North American pitvipers, and particularly in a non-threatened species that can serve as a surrogate for threatened and endangered …