Management of volunteer horseradish is a major challenge in fields when horseradish is included in the crop rotation. Three field studies were conducted: 1) to evaluate the growth habit and density of volunteer horseradish, 2) to evaluate the efficacy of fall herbicide applications for control of volunteer horseradish, 3) to evaluate the tolerance of subsequent horseradish crops to persisting soil residues of halosulfuron. One year following horseradish production, field infestations of volunteer horseradish ranged from 0.08 to 6.60 plants/m2 with the majority of plants emerging from established roots left below the depth of horseradish harvest and tillage. Fall herbicide applications provided effective control of volunteer horseradish compared to the nontreated control. Combinations of 2,4–D tank–mixed with glyphosate, iodosulfuron, halosulfuron, or rimsulfuron:thifensulfuron achieved the greatest control of volunteer horseradish and reduced volunteer horseradish densities to less than 1 plant /m2, while glyphosate alone provided the least control and density reduction. In addition to volunteer horseradish control, combinations of 2,4–D with glyphosate, iodosulfuron, halosulfuron, or rimsulfuron:thifensulfuron also provided 97% or greater control of winter annual weeds (henbit, common chickweed, and Carolina foxtail). Although the herbicide halosulfuron is very effective at controlling volunteer horseradish, it has the potential to injure future horseradish crops due to soil persistence. Field studies showed that after 4 months following a June halosulfuron application, horseradish can be replanted with no visual injury or reduction in root biomass. Tillage may provide temporary removal of volunteer horseradish plants, however, herbicide applications (e.g., 2,4–D with halosulfuron, iodosulfuron or rimsulfuron:thifensulfuron) provide the most consistent, complete control of volunteer horseradish.

Falling is a significant risk for older adults in Canada. Suffering a fall can result in injury and reduced quality of life which may include loss of autonomy. Additionally, injuries and rehabilitation from falls are a significant resource burden on the healthcare system. With the increasing proportion of older adults in Canada, there will be an increase in incidence of falls. Early identification of fall-risk is an essential step for the prevention of falls, and will provide the opportunity for fall-prevention interventions for at-risk older adults. This research is comprised of four projects that investigate and enhance current methods of fall risk detection which has potential to improve the quality of life of older adults. The first study was a scoping review that identified tools for self-assessment of fall-risk. Seven distinct fall-risk self-assessments were identified; of which most were survey based. The most effective self-assessment tools were those that included physical assessments, with interactive technology-based assessments showing exceptional promise in preliminary studies. While self-assessment is an important first-line defense for fall-risk identification and monitoring, more sensitive measures that require administration by trained professionals are likely required for accurate prediction of fall risk. The second project concurrently investigated a battery of clinical, physiological, and biomechanical assessments, to determine which measures, alone or in combination, best retrospectively classified fall risk. Ten clinical balance and mobility tests, comprising 40 unique measures, 5 physiological assessments, and 45 gait measures were included. From this extensive battery, only 5 measures were required to classify fallers with 92% sensitivity and consisted only of gait measures. A practical clinical fall risk detection tool must be both time efficient and accurate. Thus it is essential to determine the minimum amount of reliable data that is required to maintain accuracy. To this end, based on the value of walking gait assessment for fall risk detection, it is essential to determine the minimum number of strides required to accurately classify fallers. To determine the number of strides required to identify fallers, subsets of a large sample of gait data measured with a GAITRite™ pressure sensing walkway were created and compared for internal consistency and variance between the reduced and complete data sets. For measures of mean values for dual-task and difference scores of walking gait it was determined that a minimum of 10 strides are required, while for measures of variability between 30-50 strides, are required. It is encouraged to acquire as much gait data as possible, however, reasonable limits may be set to reduce the strain on older adults. This will allow for studies to include additional measures, such as clinical tests which prolong the experiment duration, to produce a clinically viable tool. Emerging technologies allow research to remain at the cutting edge and provide opportunities to expand into new markets. The use of Microsoft Kinect V2 for measurement of walking gait will allow for long term monitoring of fall status in the homes of older adults. To this end, we developed a walking stride detection algorithm that can be utilized for measurement of gait. The proven measurement accuracy of the Microsoft Kinect depth sensing capability coupled with an accurate and reliable stride detection algorithm provides the opportunity for affordable and portable gait analysis. This algorithm can be utilized with any 3D depth sensing technology, and future investigations will assess the accuracy across devices and clinical populations. / Graduate / 2019-09-14

2 pp. / Alfalfa varieties differ in fall dormancy, defined as growth during the fall. Nondormant alfalfa varieties are usually planted in mild winter areas for their ability to grow in the late fall, winter, and early spring. Select alfalfa varieties that have resistance to potential pest problems. Alfalfa varieties are available that have salt tolerance or are Roundup Ready. Ratings are provided in this publication. Many of the varieties listed in this publication have been tested for yield and final stand by the University of Arizona in small plot trials. Revised 10/2016. Most recent version 09/2015

Class of 2014 Abstract / Specific Aims: To assess older adults’ knowledge of medications associated with an increased risk of falls and to evaluate the impact of pharmacist counseling on knowledge of medication-related fall risk. Subjects: Community-dwelling adults 60 and older. Methods: Data were collected using an online questionnaire consisting of 15 knowledge-based items to determine awareness of medication-related fall risk, four items to determine pharmacist counseling experience, fall history, and number of medications taken, and two items to collect demographic information (age and gender). Main Results: Two hundred and six community-dwelling older adults (mean age = 69.07 years, SD = 5.59) participated in the study by completing all or part of the questionnaire. The number of older adults who reported having fallen within the last five years was 90 (43.7%). The knowledge-based portion of the questionnaire was completed in its entirety by 162 older adults (80 males, 81 females, one unreported gender; mean age = 68.7 years, SD = 5.12). One hundred and nineteen of 162 (73.5%) questionnaire respondents scored below 70% on the knowledge assessment (mean score 49.3%, SD = 26.8). The 12 respondents (7.6%) who reported having received counseling from a pharmacist regarding medication-related fall risk scored significantly higher on the knowledge assessment compared to the 145 respondents who did not (mean score 61.66% versus 48.09%, p = 0.01). Conclusion: A majority of community-dwelling older adults lacked knowledge of medications associated with an increased risk of falling. However, those who had been counseled by a pharmacist demonstrated greater awareness of medication-related fall risk. Thus, pharmacist counseling of older adults regarding medications and fall risk should be promoted.

Fall accidents are one of the most serious problems leading to unintentional injuries and fatalities among older adults. However, it is difficult to assess individuals' fall risk and to determine who are at risk of falls and in need of fall interventions. Therefore, this study was motivated by a need to provide a cogent fall risk assessment strategy that may be conducive to various wireless platforms. It aimed at developing a fall risk assessment method for evaluating individuals' fall risk by providing diagnostic modalities associated with gait. In this study, a "determinants of gait" model was adopted to analyze gait characteristics and associate them with fall risk. As a proof of concept, this study concentrated on slip-induced falls and the slip initiation risks. Two important parameters of determinants of gait, i.e. the pelvic rotation and the knee flexion, were found to be associated with slip initiation severity. This relationship appeared to be capable of differentiating fallers and non-fallers within older adults, as well as differentiating normal walking conditions and constrained walking conditions. Furthermore, this study also leveraged portable wireless sensor techniques and investigated if miniature inertial measurement units could effectively measure the important parameters of determinants of gait, and therefore assess slip and fall risk. Results in this study suggested that pelvic rotation and knee flexion measured by the inertial measurement units can be used as a substitution of the traditional motion capture system and can assess slip and fall risk with fairly good accuracy. As a summary, findings of this study filled the knowledge gap about how critical gait characteristics can influence slip and fall risk, and demonstrated a new solution to assess slip and fall risk with low cost and high efficiency. / Ph. D.

BACKGROUND: Age-related deterioration in the nervous system results in the decline of motor and cognitive abilities, which both have been identified as contributing to fall risk in older adults. Dual-task gait, which involves walking while performing a secondary cognitive task, is a common way to assess the interactions between cognitive and motor function. Previous work has established associations between the cost of the cognitive load on gait parameters (e.g., velocity) and fall risk in older adults. However, to date, no study has explored the potential value of combining a direct measure of performance on the cognitive component of the dual-task with the gait measures in fall risk prediction modeling. RESEARCH QUESTIONS: Does including measures of performance on the cognitive task in dual-task walking with the gait velocity measures enhance the capacity to predict fall risk. Is this predictive capacity different in models employing dual-task gait velocity versus models including the cost of the cognitive load on gait velocity? METHODS: Thirty-two community-dwelling older adults (76 years ± 3.44) were classified as fallers (n = 17) and non-fallers (n = 15) based on self-report of having at least one fall in the past 12 months. They completed single-task and dual-task walking on a pressure-sensing electronic walkway system. A progressively enhanced series of logistic regression models were performed commencing with gait velocity during the dual-task (Loaded Gait Velocity, LGV) as the covariate in predicting fall risk. This model was subsequently augmented by adding a measure of cognitive performance covariate and then further augmented with the addition of the interaction variable between the LGV and the cognitive performance variables. This stepped series of modelling was then repeated with the dual-task cost gait velocity (DTCGV, difference in gait velocity between single and dual-task). RESULTS: With the addition of the cognitive measures (CM) and the interaction variables between the GV and CM variables, in both the LGV and DTC_GV models, the Nagelkerke’s R square increased as did the models’ respective sensitivity. Notably, the model including the LGV, CM and the interaction variables achieved 88.2% sensitivity, 80% specificity, with an overall classification accuracy of 84.4%. DISCUSSION: This study is the first to show that the ability to identify fallers and non-fallers is enhanced by using both gait and cognition measures as well as interaction variables between gait and cognition measures. Further, our findings suggest that the added value of the cognitive measures is best realized with LGV rather than DTCGV. It reasons that because DTC already encompasses the cost of the cognitive load on the motor performance (gait velocity), combining it with cognitive metrics does not enhance its predictive capacity. This work suggests there is clinical utility of including cognitive performance measures in fall risk modeling as well as it provides further evidence of the interplay between cognitive and motor function in fall risk. / Graduate

The introduction of pyramided Bacillus thuringinesiss (Bt) in field corn, Zea mays L. has helped reduce kernel and foliar damage from caterpillar pests including fall armyworm, Spodoptera frugiperda (J.E. Smith) and corn earworm, Helicoverpa zea (Boddie). These pests can also be controlled with diamide insecticides. No compensation for manual kernel damage occurred at any section of the ear for Bt or Non-Bt corn. No consistent impacts on corn growth or yield were observed following foliar applications of diamide insecticides at various growth stages. The diamides exhibit longer residual efficacy than other insecticides available for fall armyworm management in field corn. Based on the level of mortality observed on young tissue developed after treatment with chlorantraniliprole, chlorantraniliprole translocated in corn and could therefore be more beneficial than other insecticides when applied during vegetative growth stages.

During 2016 and 2017, studies were conducted to determine the effects of Spodoptera frugiperda (J.E. Smith) on both damage and yield of Sorghum bicolor (L.) Moench and Zea mays (L.) when infested during the whorl stage. Results from damage ratings suggest that as the amount of overall plants infested increased, overall damage rating increased. However, yield results suggested that there was no yield loss as percent infested plants increased. Other studies were conducted to determine the most sensitive vegetative growth stages of grain sorghum and field corn. Manual damage studies suggests that extensive damage to field corn during growth stages V9 to V15 will cause significant yield loss. Also, damage to grain sorghum after growth stage V8 and prior to boot stage can cause significant yield loss.

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Tripping causes a significant number of falls in the elderly. These falls often result in medical costs, hospitalization, disability, decrease in quality of life, and sometimes death. Knowledge of why trips occur and the mechanics of successful recovery from a trip is critical to increasing knowledge of how to prevent falls due to trips. Two separate studies are reported in this thesis. The first study assessed if men recover from a trip equally well when stepping with their dominant or non-dominant lower limbs. An experimental model of tripping was used to determine each subject's trip recovery capability when stepping with the dominant or non-dominant lower limb. Although most subjects were able to recover better when stepping with one lower limb compared to the other, there was no recognizable trend across the subjects. Based on these results, there is insufficient data to recommend the preferential investigation of the dominant or non-dominant lower limb in future trip research. The second study investigated peak joint torques after stepping to recover from a simulated trip. The same protocol as the first study was used for simulating trips. Increasing trip severity resulted in increased ankle plantarflexor torque in young subjects and increased hip extensor torque in both young and older subjects. Older men used higher hip extensor torques and lower knee extensor torques compared to young men. Implications to falls from trips are discussed. / Master of Science