Intraear Compensation of Field Corn, Zea mays, from Simulated and Naturally Occurring Injury by Ear-Feeding Larvae.

Ear-feeding larvae, such as corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), can be important insect pests of field corn, Zea mays L., by feeding on kernels. Recently introduced, stacked Bacillus thuringiensis (Bt) traits provide improved protection from ear-feeding larvae. Thus, our objective was to evaluate how injury to kernels in the ear tip might affect yield when this injury was inflicted at the blister and milk stages. In 2010, simulated corn earworm injury reduced total kernel weight (i.e., yield) at both the blister and milk stage. In 2011, injury to ear tips at the milk stage affected total kernel weight. No differences in total kernel weight were found in 2013, regardless of when or how much injury was inflicted. Our data suggested that kernels within the same ear could compensate for injury to ear tips by increasing in size, but this increase was not always statistically significant or sufficient to overcome high levels of kernel injury. For naturally occurring injury observed on multiple corn hybrids during 2011 and 2012, our analyses showed either no or a minimal relationship between number of kernels injured by ear-feeding larvae and the total number of kernels per ear, total kernel weight, or the size of individual kernels. The results indicate that intraear compensation for kernel injury to ear tips can occur under at least some conditions.

Injury and interplant compensation for southwestern corn borer (Lepidoptera: Crambidae) infestations in field corn.

Growers that plant Bacillus thuringiensis (Bt) Berliner corn (Zea mays L.) hybrids are required to plant non-Bt corn for resistance management. Refuge in a bag (RIB) is an emerging approach for resistance management where, for some hybrids having multiple Bt traits for a target species, the refuge is planted as a blend of Bt and non-Bt corn. Studies were conducted to evaluate how southwestern corn borer (Diatraea grandiosella Dyar), when infested at different densities and growth stages, affected the yield of infested, non-Bt plants and neighboring Bt plants. Infesting non-Bt corn plants with southwestern corn borer larvae caused significant injury. Both the number of larvae infested on plants and the timing of these infestations affected the number of kernels per ear, total kernel weight, and the weight of individual kernels. Infestation timing was more important than the number of larvae inoculated onto plants, with pretassel infestations causing more yield loss. There was little compensation by Bt plants that were adjacent to infested plants. Thus, the risk of yield loss from stalk tunneling larvae in a refuge in a bag scenario should be directly proportional to the percentage of non-Bt plants and the level of yield loss observed in these non-Bt plants. Because current refuge in a bag systems have five or 10% non-Bt corn plants within the seed unit, the likelihood of substantial yield losses from infestations of corn boring larvae is remote given our results, especially for infestations that occur after silking has begun.

Effect of resin cure mode and fluoride content on bracket debonding.

Enamel decalcification around brackets is sometimes observed during and after orthodontic treatment. Reports in the literature suggest that the preventive advantage of fluoride-releasing adhesive resins may be compromised by an increased incidence of bond failure. The purpose of this study was to determine the effects on shear debonding of incorporating fluoride into the bracket bonding system. Another purpose was to determine the effect of polymerization mode on debonding. Orthodontic brackets were bonded to bovine enamel using one of three types of adhesive resin--no-mix, chemically cured, or light-cured--each formulated with and without fluoride. The teeth were stored in artificial saliva for 24 hours or 30 days and then debonded in shear. Data analysis was performed using ANOVA followed by post-hoc multiple comparison between group pairs. It was found that: (1) fluoride had either no effect or it increased the bond value; (2) the no-mix adhesive demonstrated the lowest bond value; (3) the duration of storage in artificial saliva had no effect on the bond value of the chemically cured and light-cured adhesives but did affect the no-mix adhesive; and (4) the no-mix adhesive released significantly less fluoride than the two other products. Thus, the presence of fluoride in the bonding adhesive does not reduce the force required to debond in shear, and chemically or light-cured adhesives provide consistently higher bond values over extended immersion times than the no-mix product.

Reliability, validity, and responsiveness of functional tests in patients with total joint replacement.

BACKGROUND AND PURPOSE: High-quality measurements are needed to develop meaningful clinical practice databases to assess the effectiveness of physical therapy. This study determined the reliability, validity, and responsiveness of measurements obtained with five functional tests graded with the newly developed Iowa Level of Assistance Scale. SUBJECTS AND METHODS: Eighty-six patients with total hip or knee replacements were tested at various time periods during their hospitalization. Patients were tested for five functional activities by four therapists to establish the reliability and test responsiveness. The Harris Hip Rating Scale was administered to assess the validity of the functional score. RESULTS: The weighted Kappa statistic supported good intratester (K = .79-.90) and moderate intertester (K = .48-.78) reliability. The correlation between the Harris Hip Rating Scale scores and the total functional scores was high (r = -.86). The total functional score was responsive to 4 days of therapy postoperatively. CONCLUSION AND DISCUSSION: The assessment of function using the Iowa Level of Assistance Scale was shown to be highly reliable, valid, and responsive in patients following total hip or knee replacements.

Influencing adherence among hypertensives.

In the treatment of hypertension, problems of nonadherence and consequent poor blood pressure control are particularly severe. Alternative intervention strategies were compared to explore means of improving adherence and lowering blood pressures. In a 3 x 4 repeated measures analysis of variance design, 115 patients were randomly selected and randomly assigned to one of three treatment modalities (routine clinic care, patient education, and contingency contracting) and were followed over four clinic visits. Subjects' knowledge about hypertension and its management, adherence to requests for regular medical follow-up, and blood pressure levels were measured. Patient education was not effective in lowering blood pressures; it produced an untoward outcome, a dropout rate higher than that for patients receiving only routine clinic care. However, contingency contracting was an effective intervention strategy for improving patient knowledge, F (1,59) = 51.32, p less than .0001; adherence to requests for regular medical care, Max L (2) = 25.9, p less than .0001; and decreasing diastolic blood pressures, F (2,49) = 3.39, p less than .05.

Utilization of reinforcement contracts to increase written evidence of the nursing assessment.

This study investigated if nursing personnel would increase written evidence of the nursing process if favorable consequences were arranged. The charting of 23 nurses was observed and tabulated for a three-week period. These base-line data were averaged and shared with each nurse, at which time each nurse set a goal (relative to increased charting) and chose a reward contingent upon achieving that goal. During the next three weeks the nurses were again observed, at the end of which results were tabulated and rewards given. The two periods were repeated. Results showed a sharp increase in charting during each reinforcement phase and a fall off during the second base-line period that was lower than the first base-line. The target behavior, therefore, was found to be increased by systematic reinforcement.