Effect of Prescribed Burning in the Forests of Buffalo National River, Arkansas

Onduso, Francis Ndar University of Arkansas 2013 해외박사(DDOD)

Prescribed burning (also referred to as controlled or hazard reduction burning) refers to the use of fire under controlled conditions to achieve a desired end product or goal. However, the nature and magnitude of the changes that result from prescribed burning are still incompletely known, and this is especially true for the forests of the Ozarks of northern Arkansas. The overall objective of the research project described herein was to obtain the data necessary to develop a better understanding of these changes, particularly as they relate to the use of prescribed burning as a management technique in the Buffalo National River of north central Arkansas. Twenty 10 by 10 m plots (10 in burned areas and 10 in unburned areas) were established in each of five different study sites (for as total of 100 plots) strategically located to represent different sections of the Buffalo River (lower, middle and upper). Data on the composition and structure of all strata of vegetation, plant debris and various soil parameters were collected from these plots or smaller subplots nested within the 10 by 10 m plots. Statistically significant differences occurred between burned and unburned plots for the values obtained for such variables as the cover of grasses, mean tree height, tree volume, surface litter biomass, and numbers of forbs, seedlings, saplings, shrubs/vines, and trees as well a number of soil parameters. These differences affect such things as species diversity, species composition and the availability of nutrients/minerals to the plants present at a given site. There is need to assess both the quantity and quality of post-fire vegetation, the amounts of litter and coarse woody debris, and the changes in the chemical and physical properties of soil that result from prescribed burning. Developing a prescribed burning model for a particular site depends upon a number of factors, the most important of which are the differences in vegetation, slope, aspect, soil and micro-climate that exist from one locality to another.

Emergence phenology and nematode associates of the woodwasp, Sirex nigricornis F. (Hymenoptera: Siricidae), in Arkansas and Mississippi forests

Hartshorn, Jessica Ann University of Arkansas 2016 해외박사(DDOD)

Sirex nigricornis F. (Hymenoptera: Siricidae) is a native woodwasp in eastern North America that inhabits dead and dying pine trees during its univoltine development. Sirex noctilio is native to Eurasia and North Africa and was discovered in the northeastern United States in 2004 after a century of accidental introductions across the Southern Hemisphere. Since then, it has spread to seven states and southern Ontario. There is concern about its potential to negatively affect the multi-billion dollar pine timber industry of the southeastern United States. Effective monitoring tools are necessary to track the spread and establishment of S. noctilio. Deladenus siricidicola Bedding (Tylenchida: Neotylenchidae) is a parasitic nematode associated with S. noctilio in its native range and has been accidentally introduced along with the woodwasp. While these nematodes have been successfully used in biological control in much of the Southern Hemisphere, the strain introduced into North America appears to be non-sterilizing and is not providing natural control. Deladenus proximus Bedding is a native nematode that infects S. nigricornis and has added S. noctilio to its host range in the northeastern U.S., implicating it as a potential control agent for S. noctilio in North America, circumventing potential issues associated with classical biological control using generalists. My objectives were to 1) examine the effect of temperature on emergence patterns of S. nigricornis and S. noctilio, 2) use molecular techniques to identify the native nematode parasitizing southeastern S. nigricornis, and 3) examine the effects of nematode infection on southeastern S. nigricornis female body size and fecundity. Trapping data from Arkansas, Mississippi, Louisiana, and Ontario were examined to determine the effect of temperature on emergence of adult female siricids. Over 1,200 native female woodwasps were collected, measured, and dissected in the fall of 2011-2015 from Arkansas and Mississippi. Nematode prevalence and virulence were higher in Arkansas than Mississippi. A 750 base pair region of the cytochrome c oxidase subunit I gene extracted from southeastern nematodes was sequenced. Nematode sequences from New York and Illinois were obtained from GenBank to examine genetic diversity across the eastern United States. Genetic distance among all nematode sequences collected was less than 0.5% indicating a single species, and continuous genetic flow, of nematodes across the eastern United States. Nematodes significantly negatively impacted woodwasp size and fecundity; infested females were smaller and produced fewer eggs than uninfested females. We believe these impacts demonstrated on S. nigricornis will translate to S. noctilio. Future directions should include inoculating S. noctilio-infested trees using virulent populations of Arkansas-collected D. proximus to test these predictions in the field.

Response of breeding birds to forest disturbance in the Arkansas Ozarks: Impacts of uneven-aged management, ice damage, and woodland restoration

McClung, Maureen Rose University of Arkansas 2013 해외박사(DDOD)

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 counts. For objective (1), I compared control and thinned plots (n=32 total) immediately after treatment (1994, data from a previous study) and fifteen years post-treatment (2008). Although vegetation differed between treatments in 1994, avian species richness, community composition, and occupancy for three of four populations (representing different nesting guilds) were similar among treatments. Fifteen years later, original differences in habitat had diminished and bird communities were still similar between treatments. For objective (2), I compared sites with high and low ice damage (n=32 total) one year before and two years after a 2009 ice storm. High damage sites had more open canopy and woody debris ground cover, but avian species richness, community composition, and occupancy of three populations (representing different nesting guilds) did not differ between years for either treatment. For objective (3), I compared recently restored woodland and mature forest sites (n=16 total) for three years following restoration (burning and thinning). Restored sites resembled woodland, with open canopy and herbaceous ground cover. They also had higher avian species diversity and more early successional species, cavity-nesters, and some canopy-nesters. These differences diminished with time since fire. Overall, forest bird communities demonstrated resilience to small-scale canopy openings created by uneven-aged management and ice damage. However, when fire was introduced along with thinning, avian communities shifted towards those more typical of open woodland. To maximize habitat availability for the most number of species, managers should plan for areas of both closed-canopy forest and woodland ecosystems.

Abiotic and Biotic Factors Affecting the Japanese Beetle in Arkansas

Petty, Bryan Mathew University of Arkansas 2013 해외박사(DDOD)

Japanese beetles are a relatively new pest to Arkansas. During my Ph.D. research I investigated the pathogens and environmental factors influencing Japanese beetle populations in the state. The prevalence of various pathogens and parasitoids attacking Popillia japonica were recorded annually from wild populations. Of specific interest was the microsporidian pathogen Ovavesicula popilliae, which I introduced as a biological control agent in the state. Details of the relationship between this pathogen and the Japanese beetle were investigated, including dose response, host range, and spore production. Additionally, annual abundance of the beetle in the region was recorded and tracked over the course of 4 years using soil sampling for larvae and pheromone traps for adults. Outdoor and indoor rearing methods were developed, and the density of these populations were recorded and compared to wild populations and temperature data, allowing us to model climate impact on the beetle. Results from these studies showed that, naturally occurring pathogens, such as Stictospora villani, Ovavesicula popilliae and Adelina sp., and parasitoids appeared to have minimal influence on the beetle populations in this region. In the case of O. popilliae, low levels of the pathogen appeared in the area naturally. This pathogen also has a narrow physiological host range outside of the Japanese beetle, primarily in other scarab larvae. O. popilliae also appears to primarily infect Japanese beetle larvae and was incapable of infecting adult beetles. Infected larvae which survived to adulthood remained infected, with the adults capable of producing on average 25 million spores. In comparison, high summer temperatures and lack of rain reduced late summer populations of larvae. In 2010, O. popilliae was released at four locations in Northwest Arkansas. In 2011 it was detected at one of those locations. A second introduction of O. popilliae was made in 2012. The results from this classical biological control effort involving the release of O. popilliae require further monitoring to confirm establishment. This information can be used to help establish long term control of this new pest in the Southern United States. This information will be of use to fruit growers, horticulturalists, turf managers, nursery operators, and homeowners.

The effects of role-play as a method in classroom management courses on preservice teachers' attitudes and effectiveness

Rudolph, Amanda M University of Arkansas 2002 해외박사(DDOD)

The purpose of the study was to investigate attitudes toward classroom management and effectiveness of classroom management practices based on a traditional classroom management course compared to a role-playing approach for preservice teachers. The majority of the research on role-play as a methodology has been qualitative and has not addressed the use of role-play in classroom management classes. The research has investigated the use of drama as a methodology in science, reading, social studies, special education classes as well as graduate school classes. The study included the two secondary education cohorts for the 2001–2002 school year. The 35 participants were enrolled in the Master of Arts in Teaching (MAT) program at the University of Arkansas. The design of the study was a repeated measure design measuring two dependent variables, attitudes of the interns toward classroom management and the effectiveness of the interns' classroom management skills. Data were collected by having the participants respond to an attitudes survey and by having a panel rate a five-minute video of each intern teaching. Each variable was measured three times, pretest, posttest and follow-up, from August to February. The data were analyzed using repeated measure ANOVAs. The study found no differences between groups over time. The analysis did reveal differences over time for the whole sample. The interns' attitudes became more positive over time while the effectiveness scores for the interns decreased over time. The attitudes of the interns may have become more positive over time due to the acquisition and mastery of their classroom management skills. Also the interns had experience using these new skills in the internship. The decrease in effectiveness scores over time may be due to the implementation and experimentation of the new classroom management skills. As the interns tried new classroom management techniques, the effectiveness score could have decreased. This could represent a dip in effectiveness rather than a sustained decrease. Unfortunately, the follow-up measure was unavailable for this variable. Further research is needed. Future research could investigate the development of classroom management skill throughout the internship. Also, more quantitative research is needed on role-play as a methodology.

Sampling Terrestrial Arthropod Biodiversity: A Case Study in Arkansas

Skvarla, Michael Joseph University of Arkansas 2015 해외박사(DDOD)

The Interior Highlands is a biodiversity hotspot, with at least 200 known endemic species, but is understudied compared to hotspots, such as the Southern Appalachians. In order to begin to rectify this issue, a nine month study was conducted from mid-March through early December at a 4 ha site at Steel Creek, Buffalo National River, in Newton County, Arkansas. Thirteen collecting methods were employed, including three colors of Lindgren funnel trap, five colors of pan trap, Malaise traps, canopy traps with upper and lower collectors, pitfall traps, and Berlese-Tullgren extraction of leaf litter, which resulted in the collection of 1311 samples during 17 collection events. Target groups, including Formicidae, Carabidae, Cerambycidae, Curculionoidea, Araneae, Isopoda, Mecoptera, Phasmida, Vespidae, Ixodidae, Phalangodidae, and select Diplopoda and Orthoptera were identified. This resulted in 47,481 specimens representing 706 species that were curated and identified, including 18 putatively undescribed species, 56 species that represented new state records, 15 non-native species, and three species of Carabidae endemic to the Interior Highlands, two of which (Rhadine ozarkensis and Scaphinotus infletus) were previously known only from the original type series. Collection data for four beetle taxa -- Buprestidae, Carabidae, Cerambycidae, and Curculionoidea excluding Scolytinae -- as well as all taxa combined were analyzed. Pitfall and Malaise traps were the most effective (define here as collecting the most species with fewest samples) combination of collection methods for Carabidae, Curculionoidea, and the combined taxa, while Malaise traps alone and Malaise or canopy traps and green Lindgren funnel traps were the most effective collection methods for Cerambycidae and Buprestidae, respectively. Color of Lindgren funnel traps was important when targeting Buprestidae and some Curculionoidea, but not Carabidae or Cerambycidae. Extrapolated rarefaction curves indicated that 300--600 samples were required per trap type (1000+ for pitfall traps) before species accumulation is saturated. Finally, four rarely collected specimens or species -- a Temnothorax curvispinosus gynandromorph, Orussus minutus, Eudociminus mannerheimii, and Merope tuber -- are treated individually in detail.

Applying Molecular and Phenotypic Tools to Characterize Flesh Texture and Acidity Traits in the Arkansas Peach Breeding Program and Understanding the Crispy Texture in the Arkansas Blackberry Breeding Program

Salgado Rojas, Alejandra University of Arkansas 2015 해외박사(DDOD)

Quantitative trait loci (QTL) utilizing a pedigree-based analysis (PBA) approach was performed in the peach breeding program for the first time. The pedigree consisted of seven-F1 populations, their parents, ancestors, and cultivars. Flesh firmness and titratable acidity (TA) were examined in 2011, 2012, and 2013. For TA, a consistent and strong QTL was identified on the proximal end of linkage group (LG) 5 of the peach genome. For flesh firmness, two QTLs were located on LG 4. The first QTL was located on the chromosomal region where the slow-melting flesh (SMF) DNA test was identified, and the second QTL was identified in the region of the endopolygalacturonase (endoPG) gene. However, the QTLs on LG 4 were not always consistent. These results indicate that PBA approach for QTL analysis can be applied with success in this mature and ongoing peach breeding program with the aim to find molecular markers associated with relevant quality traits, which is the first step to apply marker-assisted breeding (MAB). Also, DNA tests associated with TA and flesh firmness were analyzed with data taken in 2013 and 2014 on this pedigree and other seedlings, selections, and cultivars to predict acidity levels and flesh texture with the final goal to validate these DNA tests and apply MAB. These tests were able to predict correctly the expected acidity levels and flesh textures of the tested individuals. Firmness and texture are critical traits in blackberry for breeders, growers, and consumers. Crispy and extremely firm fruits were characterized for two blackberry selections which had been observed to have low color reversion (a postharvest disorder). Firmness of these selections and its seedlings were tested in 2013 and 2014. Results indicated that crispy selections had superior firmness and a higher postharvest storage potential compared to cultivars and other selections in the program. These results are important, because firmness will be increased and color reversion will be reduced by use of this germplasm. This research also contributed to better understanding of the physical aspects of crispy and non-crispy genotypes, providing more information about this aspect of blackberries.

The Effect of School and Neighborhood Environmental Factors on Childhood Obesity

Qian, Yiwei University of Arkansas 2014 해외박사(DDOD)

The dissertation consists of three chapters exploring the effect of school program and neighborhood environment on childhood obesity outcome using individual panel data set of Arkansas public schoolchildren. The first chapter (Section 2) investigates how the Fresh Fruit and Vegetable Program (FFVP), a program that provides funding for the distribution of free fresh fruits and vegetables to students in participating schools, affects childhood obesity. We combine matching methodology and difference-in-differences analysis to estimate the effect of the FFVP on childhood BMI outcomes. Estimates of the FFVP effect are sensitive to different matching methods. Methods that provide a good balance between treatment and control samples show that the FFVP program causes an economically meaningful reduction in the body mass index of participating children. Less strict matching methods yield insignificant results. The second chapter (Section 3) measures the effect of fast-food restaurant density around the residences of Arkansas public schoolchildren on BMI outcomes. We use the distance from the child's residence to the nearest US highway or interstate highway as an instrument for the density of fast food restaurants. The results show that the exposure of fast food restaurants around the home environment does have significant and positive effects on children's BMI z-scores. Our results also indicate that some subpopulations---children who are more affluent, rural, non-minority and female---are disproportionately affected by fast food proximity. Finally, the third chapter (Section 4) analyzes the effect of neighborhood parks around residences of northwestern Arkansas children on BMI outcomes. Our dataset covers the 2004 through 2007 period. To build comparative groups, we employ propensity score matching to measure the average treatment effect on the treatment group. The results indicate that proximity of neighborhood parks from the residence have a significant and negative effect on children's BMI z-scores in both the rural and urban areas, with some heterogeneity in the effects across gender. Specifically, our results show that girls in urban and rural areas are significantly influenced by neighborhood parks. The park effect is significant for boys in rural areas but not for boys in urban areas.

A method for analyzing the financial viability of a rural geriatric provider-based outpatient clinic

McAtee, Robin E University of Arkansas for Medical Sciences 2005 해외박사(DDOD)

Older adults living in rural areas lack access to geriatric specialty care. A geriatric provider-based outpatient clinic is a unique primary care venue that meets this need for access. The specialized clinic assembles geriatric professional experts from multiple disciplines to work as a team to provide comprehensive care for the older adult. However, little is known about the financial viability of geriatric provider-based outpatient clinics, especially those associated with a rural hospital. Therefore, the purpose of this study was to develop a method for analyzing the financial viability of a geriatric provider-based outpatient clinic within the context of its owner hospital. The three research questions developed to address the purpose were: (1) What is the net profit or loss of the rural geriatric provider-based outpatient clinic? (2) What is the identifiable downstream net profit or loss resulting from business generated by geriatric provider-based outpatient clinic patients to the owner hospital? (3) What is the overall profit or loss of the geriatric provider-based outpatient clinic when combined with the related hospital downstream net profit or loss?. A descriptive case-study approach was used in which data were collected for a 12-month retrospective period regarding a geriatric provider-based outpatient clinic and the associated downstream revenue. The data were obtained from the hospital's financial management system using a unique clinic identifier to obtain specific clinic and financial data. Data revealed 5411 patient visits were made to the practitioners of the provider-based geriatric clinic, 2607 visits were made by the geriatric practitioners to inpatients and 1328 visits were made to nursing home residents. The results of the financial analysis revealed a $112,270 loss for the clinic itself and an overall loss of $326,871 when the downstream net impact was added. Although, the study was limited by the inability to track referrals through the rural healthcare system, the case study revealed valuable areas in which further refinement could improve areas of operations and financial accountability.

The relationship between patient trust of nursing staff, postoperative pain, and discharge functional outcomes following a total knee arthroplasty

Burge Bowren, Donna Mechelle University of Arkansas for Medical Sciences 2008 해외공개박사

One of the most common operative procedures undergone by an older adult is a total knee arthroplasty which is performed to reduce difficulty walking and performing activities of daily living. A fear of poorly controlled pain may discourage an individual from having a total knee arthroplasty, and unrelieved pain during hospitalization may result in failure to meet desired discharge functional outcomes and a prolonged length of stay. Nursing management of patient pain is a key component of postoperative patient care. Patient trust of the nursing staff may affect postoperative pain. However, the relationship between patient trust of nursing staff and pain has not been studied. Thus, the aims of this study were to describe patient trust of nursing staff and describe the relationships among patient trust of nursing staff, postoperative pain, and discharge functional outcomes in patients undergoing total knee arthroplasty. The study utilized a correlational study design. Study setting was an acute care, private, not-for-profit hospital. Participants completed the Trust Subscale of the Patient's Opinion of Nursing Care to assess trust of nursing staff. Numeric Analog Scale (NAS) measured level of pain. Functional outcome was obtained from knee flexion gain scores. Descriptive statistics were used to describe the sample. Correlation statistics, independent two-sample t-test, and linear regression were utilized to achieve study aims. Sixty-eight elders participated with a mean age of 66.4 years. The majority of the participants were female (79.4%) and Caucasian (100%). Average NAS pain score was 5.0. Average gain score was 26.8. Average trust score was 47.5, indicating a higher level of trust. There was no statistically significant association between trust and pain (rho = -0.116, p = 0.347), between trust and functional outcome (rho = 0.073, p = 0.552) and between pain and functional outcome (rho = 0.055, p = 0.657). In the regression model with age, gender and the number of hospitalizations as predictors, the number of hospitalizations was the only significant predictor of trust (p=0.04). As the number of hospitalizations increased, patient trust of the nursing staff decreased. Finally, trust and pain were not predictors of functional outcome in the regression model controlling for age and sex. This study suggests patients undergoing total knee arthroplasty may benefit from discussing with nursing staff to identify issues from prior hospital experiences. This discussion can identify potential problems which could occur following the total knee arthroplasty. Nursing interventions can be designed to build trust between patient and nursing staff to improve the hospital experience.