ON MULTIVARIATE ANALYSES OF CROSSOVER DESIGNS

In crossover experiments, treatments are assigned to experimental units in successive periods. Traditional analyses of crossover designs with three or more periods assume that the observations in successive periods satisfy conditions similar to those utilized in the analysis of many repeated measures experiments. The successive measurements are assumed to satisfy conditions known as the Huynh-Feldt conditions. This paper gives a test for the Huynh-Feldt conditions and discusses possible analyses of crossover experiments, including tests for carryover, when the Huynh-Feldt conditions are not satisfied

ALTERNATIVE ANALYSES OF CROSSOVER DESIGNS WITH MORE THAN TWO PERIODS

A crossover experiment is a special form of a repeated measures experiment. An appropriate analysis of a repeated measures experiment depends on the form of the varian-cecovariance matrix of the repeated measures. Certain forms of this matrix yield valid analysis of variance F -tests while other forms invalidate these tests. In a crossover experiment where analysis of variance tests are invalid, two alternative tests of a linear contrast of the parameters are proposed. In addition to these approximate t-tests, three alternative methods for testing for equal treatment effects and equal carryover effects are proposed. A simulation study is conducted to evaluate these proposed alternative test procedures for power. Confidence levels and confidence interval lengths are also examined for those procedures from which an estimate of the linear contrast can be made

Response surface modeling to predict fluid loss from beef strip loins and steaks injected with salt and phosphate with or without a dehydrated beef protein water binding adjunct

This study was conducted using response surface methodology to predict fluid loss from injected beef strip steaks as influenced by levels of salt and sodium phosphates (SP) in the injection brine. Also, a beef-based dehydrated beef protein (DBP) water binding ingredient was evaluated. Paired U.S. select beef strip loins were quartered before being injected to 110% of initial weight with a brine containing salt and SP (CON) or salt, SP and 5% DBP. Steaks were sliced, overwrapped and stored in the dark for 4 d. Purge values ranged from 0.6% to 4.6% for CON and 0.3% to 2.1% for DBP. Purge loss values when accounting for the fluid lost from injection to slicing were as high as 6.8% for CON brines, but only 2.8% for DBP brines. The equations generated here and the DBP product could help producers achieve acceptable purge while reducing sodium use.Keywords: beef, response surface, phosphat

Use of Nondestructive Sensors to Assess Nitrogen Status in Potted Dianthus (Dianthus chinensis L.) Production

Optical sensors are a fast and nondestructive new technology used to estimate plant chlorophyll content by measuring leaf reflectance or absorbance of light. The objective of this study was to evaluate the reliability of normalized difference vegetative index (NDVI) values calculated by the GreenSeekerTM hand held sensor as an indirect indicator of dianthus (Dianthus chinensis L.) N status, and investigate nutrient supplementation on deficient ‘TelstarTM White’ and ‘TelstarTM Red Picotee’ plants. Pots were supplemented with 0, 5, 10, 15, and 20 g of 15N-9P-12K controlled release fertilizer (CRF). Soil and plant analysis development (SPAD) chlorophyll meter, GreenSeekerTM NDVI sensor, and atLEAF meter readings were recorded for four consecutive weeks. At 49 days after planting (DAP), the 0 g and 5 g treatments were found deficient and half of the pots were supplemented with extra fertilizer for treatment correction (C 0 and C 5, respectively). The SPAD and atLEAF readings showed stronger correlation to actual leaf N concentration compared to the GreenSeekerTM. The GreenSeekerTM readings were less correlated with leaf N concentration at early stages of establishment due to plants small size and background noise, as well as at later stages of establishment due to anthesis. Dianthus quality responses generally increased as fertilizer rates increased. The additional correction treatment showed a significant improvement in C 5 and no significant improvement on C 0, indicating that the correction treatment was beneficial for dianthus when initial amount of fertilizer was applied.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Seasonal Fires, Bison Grazing, and the Tallgrass Prairie Forb \u3ci\u3eArnoglossum plantagineum\u3c/i\u3e Raf.

Fire and grazing can interact to affect the structure and composition of vegetation communities in a manner that may differ from the effects of fire or grazing that occurs in isolation of the other. In order to better understand the effects of a fire-grazing interaction at the level of an individual plant species, we studied the response of a perennial tallgrass prairie forb, Arnoglossum plantagineum Raf., to the interaction of spring and summer fires with grazing by bison (Bison bison L.). During one field season (2006), we collected data in areas that had been treated with summer fires while in a subsequent field season (2007) we collected data in areas that had been treated with spring fires. Many measures of plant growth (plant height, vegetative biomass, and total biomass) and reproductive effort (reproductive biomass, indices of flowering plant density) suggested greater resource availability for individuals of A. plantagineum growing in areas that had been recently burned and were being heavily grazed by bison. However, the response of these variables to the fire-grazing interaction often varied among differing topographical positions. Our results demonstrate that the interaction of fire and bison grazing can further interact with topographical position in tallgrass prairie to affect the growth and reproductive effort of the perennial forb A. plantagineum

Effects of Body Armor and Load Carriage on Lower Limb Joint Movement

This study investigated the impact of body armor weight and load magnitude and distribution on the lower extremities during walking. Range of motion (ROM) was assessed while seven healthy, male, right-handed, military university students walked while wearing seven different garments of varying weights (0.06 kg, 9 kg, 18 kg, and 27 kg) and load distributions. Decreased pelvic rotation found with an increase in weight implies decreased mobility by restricting the leg’s swing to propel the body forward. Increased ROM for pelvic tilt found with increased weight results from increased forward inclination suggesting an increased possibility for fatigue and musculoskeletal pain in the lower back. This study substantiated that a balanced weight distribution can minimize risk of chronic lumbar pain by reducing forward lean of the trunk or pelvic tilt; a balanced weight distribution around the torso at a level of 27 kg showed less change in ROM for pelvic tilt than an unbalanced weight distribution