Doctor of Philosophy

dissertationThe purpose of this study was to determine differences in mathematics performance and cognition between acute bouts of resistance exercise, aerobic exercise, and a nonexercise control in 5th-, 8th-, and 10th-grade students. Aerobic exercise has consistently shown small, positive changes in youth cognition and academic achievement. However, no research exists documenting the effects of resistance exercise on similar outcomes in youth. This study utilized a randomized crossover design. Participants performed 30 minutes of aerobic exercise, resistance exercise, and nonexercise in a randomized order, separated by 7 days each. Immediately following each exercise intervention, participants were assessed using separate 10-question math tests created from the New York state standardized mathematics exams. Additionally, cognition was assessed in 8th- and 10th-graders after each exercise intervention using the Stroop Test (Victoria version). Data were analyzed using repeated measures ANOVA. Results indicated that for both 5th- and 8th-grade students, math performance increased significantly following resistance exercise over the nonexercise control. Practically significant increases were seen in math performance following aerobic exercise in 5th-, 8th-, and 10th-graders, and following resistance exercise in 10th-graders as compared to the nonexercise control. Amongst 8th-graders, significant differences were found in Stroop test performance following both aerobic and resistance exercise as compared to the nonexercise control. Tenth-grade students performed significantly better on the Stroop Dot and Color test following aerobic exercise, and better on the Stroop Dot test following resistance exercise as compared to the nonexercise control. Findings from this study are novel in that they mark the first instance of resistance exercise demonstrating increases in academic achievement and cognition in youth. Importantly, it appears that both resistance and aerobic exercise exhibit similarly positive effects on academic outcomes in three different youth age groups. Findings could influence the use of acute resistance exercise as an alternative or complement to aerobic activity for educators aiming to increase pupils' physical activity and academic performance concurrently

G07-1678 The Relationship of Dry Bean and Sugar Beet Pathogens with Common Weeds in Nebraska Production Fields

Certain weeds in the Nebraska Panhandle can serve as hosts for pathogens that cause disease in dry edible beans and sugar beets. Properly managing weed populations and rotating with nonhost crops can help control the spread of disease. This 2007 NebGuide discusses the symptoms, results and control of these pathogens

Management of Montezuma Quail in Texas: Barriers to Establishing a Hunting Season

Montezuma quail (Cyrtonyx montezumae) occur throughout the desert southwest, ranging from Vera Cruz, Mexico to southern Arizona, New Mexico, and western Texas. In Mexico, Montezuma quail are a protected species and in New Mexico and Arizona they are a harvested gamebird. The distribution of Montezuma quail has changed significantly during the past century. Currently Montezuma quail are limited in Texas to the Trans-Pecos with remnant populations in the Edwards Plateau. Although Montezuma quail are classified as a gamebird in Texas, seasons are currently closed. Recently, Texas Parks and Wildlife Department has expressed interest in opening the season on Montezuma Quail. In this manuscript I review and chronicle the sociological and biological barriers associated with opening a hunting season for Montezuma quail in Texas. Sociological barriers include landowner competency and trust in state agencies, a growing voice among nonconsumptive users in Texas, a localized ecotourism industry centered on Montezuma quail, and other cultural factors. Biological barriers include lack of data on Montezuma quail population distribution, trends, and abundance; lack of scientific data relative to habitat management for Montezuma quail; or studies simulating the effects of harvest on Montezuma quail. Prior to implementing a hunting season on Montezuma quail in Texas, resource agencies will need to address the biological and sociological challenges outlined in the manuscript

G07-1678 The Relationship of Dry Bean and Sugar Beet Pathogens with Common Weeds in Nebraska Production Fields

Certain weeds in the Nebraska Panhandle can serve as hosts for pathogens that cause disease in dry edible beans and sugar beets. Properly managing weed populations and rotating with nonhost crops can help control the spread of disease. This 2007 NebGuide discusses the symptoms, results and control of these pathogens

G07-1753 Cercospora Leaf Spot of Sugar Beet

The symptoms, factors favoring infection, prediction and control measures for Cercospora leaf spot of sugar beet is described in this 2007 NebGuide

NF00-426 Rhizopus Head Rot of Sunflower

This NebFact discusses the increase in sunflower production and the potential for diseases

G07-1753 Cercospora Leaf Spot of Sugar Beet

The symptoms, factors favoring infection, prediction and control measures for Cercospora leaf spot of sugar beet is described in this 2007 NebGuide

Evaluating chickpea lines for disease resistance in western Nebraska

Chickpeas (Cicer arietinum) are a newly emerging alternative crop for western Nebraska. Interest in this crop is increasing with approximately 4,000 hectares cropped per year over the last 5 seasons. Several disease problems have been identified that will limit optimal production success if left unchecked. These diseases include Ascochyta blight, caused by A. rabiei, and a root disease complex consisting of Rhizoctonia solani, Fusarium spp., and Pythium spp. Thus trials were conducted at multiple locations (2003–2004) throughout the Nebraska Panhandle for testing chickpea lines and cultivars for yield potential and tolerance to both types of diseases under both dryland and irrigated conditions. Differences were observed between entries and their yield response to the different irrigation systems. In general, those entries with better root disease tolerance tended to yield better from irrigated production, while those more susceptible to disease performed better under dryland conditions. Identification of better sources of resistance is encouraging for the new chickpea industry in Nebraska and this process will continue as interest and production expands

Identification of Sources of Bacterial Wilt Resistance in Common Bean (\u3ci\u3ePhaseolus vulgaris\u3c/i\u3e)

Over the last decade, bacterial wilt, caused by Curtobacterium flaccumfaciens pv. flaccumfaciens, has reemerged in the Central High Plains (Nebraska, Colorado, and Wyoming) and has been identified in almost 500 fields. Affected fields were planted with bean (Phaseolus vulgaris) from multiple market classes and seed sources, including yellow, great northern, pinto, kidney, cranberry, black, navy, pink, and small red, and incidence varied from trace levels to \u3e90%. One wiltresistant bean, ‘Emerson’, is available today but it is grown on a limited basis as a specialized cultivar for targeted markets in Europe and cannot be grown in all fields where the disease has recently been identified. Thus, we are faced with an emerging problem that must be addressed by utilizing newly developed resistant cultivars. This study was initiated to evaluate the Phaseolus National Plant Germplasm System (NPGS) bean collection for resistance to C. flaccumfaciens pv. flaccumfaciens in the ongoing effort to develop a new wilt-resistant cultivar adapted to this region. In total, 467 entries, including accessions from the NPGS, several commercial great northern and pinto cultivars, and University of Nebraska experimental lines, were screened with a highly virulent orange strain of C. flaccumfaciens pv. flaccumfaciens previously recovered from an infected great northern bean plant in Nebraska. Bacterial wilt severity ratings were 1.0 to 9.0 (0 to 90% incidence). Of the 427 accessions from the NPGS, only 1 showed resistance (0.23%), 19 showed intermediate resistances (4.45%), and the remainder were susceptible (95.34%). PI 325691 was identified as a source of bacterial wilt resistance. It was screened against six additional C. flaccumfaciens pv. flaccumfaciens strains and still produced resistant reactions. PI 325691 is a wild common bean (P. vulgaris) collected 8 miles South of Tzitzio, Michoacán, Mexico; however, it has a small seed size (5.3 g 100–1 seeds) that is commercially unacceptable. It will take several backcrosses to transfer this resistance to bacterial wilt and recover the seed size into a cultivated bean

Efficacy of Line Drives to Locate Montezuma Quail at Elephant Mountain Wildlife Management Area (Poster Abstract)

There is little information on the status of Montezuma quail (Cyrtonyx montezumae) in Texas. Most of the literature that does exist is either outdated or from out-of-state sources (i.e., New Mexico and Arizona). We initiated a pilot study to document and update general life history information of Montezuma quail at Elephant Mountain Wildlife Management Area, Brewster County, Texas in March 2000. To establish the study area, we used sign of recent Montezuma quail use (i.e., diggings) to document areas of use, resulting in a 114-ha area on top of Elephant Mountain proper. This study plot subsequently was sampled by the 3 line drives consisting of 17, 12, or 10 observers/line. The observers walked abreast of each other towards a designated point, covering the entire width (600 m) of the sample area. Two line drives were conducted in December 2000 (17- and 12-observer lines) and 1 in March 2001 (10-observer line). All line drives were conducted in the morning between 0900–1200 hrs. Average distances between observers for the 17-, 12-, and 10- observer lines were 35, 50, and 60 m, respectively. The average speed for all 3 line drives was 2.5 km/hr. Only the 17-observer line drive detected quail. Two coveys were flushed, 1 of 4 birds (1 M and 3 F) and 1 of 5 birds (2 M and 3 F). The birds only flushed if the observer was \u3c 1 m from them. One possible reason for the low detection of quail may be their defense strategy, which is to crouch down and lay motionless. Based on these limited data, we infer that to increase the probability of effectively locating Montezuma quail, the distance between observers must be \u3c 35 m and the number of observers increased. Line drives with few observers and large spacing between observers may not be a suitable technique to locate Montezuma quail