Dawn M. VanLeeuwen

Sufficient conditions for orthogonal designs in mixed linear models

This paper revisits the concepts of orthogonal block structure and orthogonal design in mixed linear models. The primary tool used in investigating these concepts is that of a commutative quadratic subspace. The idea of an error orthogonal design is introduced. These designs are less restrictive than orthogonal designs, but retain almost all of the nice properties. Easy-to-check conditions are given that insure a model has an orthogonal or error orthogonal design. The results given are most useful for those mixed models with a nested covariance structure or those whose covariance structure comes from random main effects.

The effectiveness of culinary curricula: a case study

Purpose – The purpose of this paper is to examine and compare current culinary student, graduated culinary student, and industry responses to educational skills attained.Design/methodology/approach – This paper uses a survey methodology to examine perceptions of what and how institutions might best prepare culinary students for success in the workplace.Findings – Students enter culinary education institutions with expectations of the experience they will gain and the skills/knowledge they will master. After graduation, they discover how prepared they are for a culinary career. Similarly, employers expect students to enter the work place with specific skills and abilities. Findings provide both similarities and differences among the respondent groups.Research limitations/implications – The study was conducted in only one country using graduates from one culinary school and industry needs of Eastern Canada. Based on an analysis of the findings, educators and industry should address key skills of the culinar...

Growth characteristics, reproductive performance, and evaluation of their associative relationships in Brangus cattle managed in a Chihuahuan Desert production system.

Balancing growth and reproductive performance in beef cattle managed in desert environments is challenging. Our objectives were to 1) evaluate trends in growth and reproductive traits, and 2) assess associative relationships between growth characteristics and reproductive performance in a Brangus herd managed in a Chihuahuan Desert production system from 1972 to 2006. Data were from bull (n = 597) and heifer calves (n = 585; 1988 to 2006) and cows (n = 525; repeated records of cows, n = 2,611; 1972 to 2006). Variables describing the growth curve of each cow were estimated using a nonlinear logistic function (each cow needed 6 yr of data). Mixed-effect models and logistic regression were used to analyze trends across years in growth and reproductive traits (both continuous and categorical). For continuous traits of calves, a slight cubic response (P < 0.01) described the dynamics of birth weight, 205-d BW, and 365-d BW across years. For categorical traits of females, positive linear trends (P < 0.05) across years were observed in percent pregnant as yearlings, calved at 2 yr of age, and first-calf heifer rebreeding (slopes ranged from 0.007 to 0.014%/yr). Autumn cow BW increased gradually until 1997 (509 kg +/- 8.8) and then decreased gradually by 0.6 kg/yr, whereas pregnancy percentage decreased gradually until 1995 (78.4% +/- 1.0) and then increased slightly by 0.2%/yr. A quadratic effect best described the dynamics of these 2 variables across years (P < 0.01) as well as estimates describing the growth curve of each cow. Specifically, asymptotic BW and age increased (P < 0.05) from 1972 to 1983 and 1990, respectively. Asymptotic age then decreased by 27% from 1983 to 1996 (P < 0.05). The maturing rate index was negatively correlated with age at first calving and calving interval (r = -0.42 and -0.18, P < 0.01), which suggested that early-maturing cows had enhanced fertility in this environment and production system. In summary, minimal changes were observed in measures of growth in bulls and heifers in a Brangus herd managed in the Chihuahuan Desert. Opposing relationships were observed among measures of cow size and fertility; as growth curves shifted toward earlier maturity, measures of reproductive performance suggested that fertility improved.

Cooking Schools Improve Nutrient Intake Patterns of People with Type 2 Diabetes

OBJECTIVE To determine whether cooking classes offered by the Cooperative Extension Service improved nutrient intake patterns in people with type 2 diabetes. DESIGN Quasi-experimental using pretest, posttest comparisons. SETTING Community locations including schools, churches, and senior centers. PARTICIPANTS One hundred seventeen people with type 2 diabetes, from diverse ethnic and socioeconomic backgrounds. INTERVENTION Series of classes for people with type 2 diabetes and their family members that incorporated Social Cognitive Theory tenets. The classes featured current nutrition recommendations for people with type 2 diabetes and hands-on cooking, where participants prepared and ate a meal together. MAIN OUTCOME MEASURES Three-day food records, completed prior to attending cooking schools and 1 month after, were used to measure changes in energy intake and selected nutrients. ANALYSIS Program efficacy was assessed using the Wilcoxon signed-rank test to compare differences between pre-training and post-training variables. ANCOVA was used to determine whether program efficacy was affected by sociodemographics. RESULTS Participants decreased (P < .05) intakes of energy, fat grams, percentage of calories from fat, saturated fat grams, cholesterol (mg), sodium (mg), and carbohydrate grams. CONCLUSIONS AND IMPLICATIONS Nutrition education incorporating hands-on cooking can improve nutrient intake in people with type 2 diabetes from diverse ethnic and socioeconomic backgrounds.

Relationship between body condition score at calving and reproductive performance in young postpartum cows grazing native range

Body condition score is used as a management tool to predict competency of reproduction in beef cows. Therefore, a retrospective study was performed to evaluate association of BCS at calving with subsequent pregnancy rate, days to first postpartum ovulation, nutrient status (assessed by blood metabolites), and calf BW change in 2- and 3-yr-old cows (n = 351) managed and selected to fit their environment of grazing native range over 6 yr at the Corona Range and Livestock Research Center, Corona, NM. Cows were managed similarly before calving, without manipulation of management, to achieve predetermined BCS at parturition. Palpable BCS (scale of 1 to 9) were determined by 2 experienced technicians before calving. Cows were classified to 1 of 3 BCS groups prior calving: BCS 4 (mean BCS = 4.3 ± 0.02), 5 (mean BCS = 5.0 ± 0.03), or 6 (mean BCS = 5.8 ± 0.06). Cows were weighed weekly after calving and serum was collected once weekly (1 yr) or twice weekly (5 yr) for progesterone analysis to estimate first postpartum ovulation beginning 35 d postpartum. Year effects also were evaluated, with years identified as either above or below average precipitation. Days to first postpartum ovulation did not differ among calving BCS groups (P = 0.93). Pregnancy rates were not influenced by calving BCS (P = 0.83; 92%, 91%, 90% for BCS 4, 5, and 6, respectively). Days to BW nadir was not influenced by BCS at calving (P = 0.95). Cow BW was different at all measuring points (P < 0.01) with BCS 6 cows having the heaviest BW and cows with BCS 4 the lightest. Cows with calving BCS 4 and 5 lost more (P = 0.06) BW from the initiation of the study to the end of breeding than cows with BCS 6. However, cow BW change at all other measurement periods was not different (P ≥ 0.49) among calving BCS groups. Serum glucose and NEFA concentrations were not influenced by calving BCS (P ≥ 0.51). Calf BW at birth (P = 0.60), branding (55-d BW; P = 0.76), and weaning (205-d BW; P = 0.60) were not impacted by cow calving BCS. Body condition score did not influence overall pregnancy rates, indicating that young cows can have a reduced BCS and still be reproductively punctual. Therefore, these results indicate that reproductive performance of young cows with reduced BCS may not be affected when managed in extensive range conditions.

A Note on the Reliability of Ranked Items

Instruments may be designed to use either Likert-type items (ratings) or ranks to obtain priority rankings of items. Models commonly used in generalizability theory (GT) provide a basis for assessing the reliability of item measurements based on ratings. However, these commonly used models do not apply when respondents are required to rank a set of items. Unlike ratings, ranks force subject effects to zero. Furthermore, ranks violate independence assumptions, and the dependence between ranks assigned to different items affects the standard error of item mean differences and, consequently, the reliability of the item comparisons. A GT analysis for ranked items is presented and used to derive standard errors for differences between item means as well as an item measurement reliability coefficient. This analysis uses a linear model that is not typically used in GT analyses but that models those features unique to ranks.

The effect of increasing amount of glucogenic precursors on reproductive performance in young postpartum range cows.

Supplementing CP and propionate salts (PS) may improve economic returns in young range beef cows by increasing the dietary supply of glucogenic precursors. A 3-yr study conducted at Corona Range and Livestock Research Center (Corona, NM) from February to mid-July in 2005 (n = 80), 2006 (n = 81), and 2007 (n = 80) evaluated days to first estrus, calf weaning weight, BW change, and metabolic responses in 2- and 3-yr-old postpartum cows grazing native range. Cows were individually fed one of three 36% CP supplement treatments after parturition, with increasing glucogenic potential (GP) supplied by RUP and PS. Supplements were isoenergetic and fed at a rate of 908 g/cow per day twice weekly. Supplementation was initiated 7 d after calving and continued for an average of 95 d. Supplement treatments provided 1) 328 g of CP, 110 g of RUP and 0 g of PS (PS0); 2) 328 g of CP, 157 g of RUP, and 40 g of PS (PS40); or 3) 329 g of CP, 158 g of RUP, and 80 g of PS (PS80). Ultimately, PS0, PS40, and PS80 provided 44, 93, and 124 g of GP, respectively. Body weight was recorded weekly and serum was collected twice weekly for progesterone analysis to estimate days to first estrus. Cows were exposed to bulls for 60 d or less beginning in mid-May. Days to first estrus exhibited a quadratic (P = 0.06) response to GP resulting from the fewest days to first estrus with the consumption of PS40. Pregnancy rates were 88, 96, and 94% for cows fed PS0, PS40, and PS80, respectively (P = 0.11). Total kilograms of calf weaned per cow exposed to bulls for the supplementation and following year increased quadratically (P = 0.09). However, supplement did not affect milk composition or yield (P ≥ 0.53). Serum acetate half-life decreased linearly (P = 0.08) with increasing GP in 2007. Predicted margins were the greatest (quadratic; P = 0.03) for cows fed PS40. Even though supplement costs were greater for PS40 and PS80, cows fed PS40 had increased profits (

Elk and Mule Deer Diets in North-Central New Mexico

33.47/cow) compared with cows fed PS0 and PS80. This study implies that young postpartum cows fed additional glucogenic precursors may have improved reproductive efficiency and may wean more calf weight per cow exposed to breeding.

Restaurant Viability: Operations Rating of Contributing Success Factors

Abstract Botanical composition of mule deer and elk diets in winter, spring, summer, and autumn was studied during 1998 and 1999 on woodland rangeland in north-central New Mexico using microhistological analysis of fecal samples. Our study area had no livestock grazing for 60 years but was moderately grazed by mule deer and elk. Elk and mule deer shared 3 of the top 5 key forage species when diets were pooled across seasons and years. These 3 species were oak (Quercus sp.), ponderosa pine (Pinus ponderosa Dougl.), and mullein (Verbascum thapsus L.). When data were pooled across seasons and years, overall dietary overlap between mule deer and elk was 64%. Diet overlaps of 50% or more occurred between mule deer and elk in all 4 seasons in both years of study. Throughout both years, mule deer and elk diets were dominated by browse. Mountain mahogany (Cercocarpus montanus Raf.) was the most abundant browse plant in mule deer diets; ponderosa pine was most abundant in elk diets. Both animals selected forbs, which were in low supply during the study. Scarlet globemallow (Sphaeralcea coccinea Pursh), a nutritious forb, was common in both mule deer and elk diets. Our study and others from woodland rangelands in New Mexico show high potential for forage competition between mule deer and elk. Elk are more dietarily adaptable to changing forage availability than are mule deer. Our study indicates that diets of mule deer and elk are not complementary on woodland rangelands in New Mexico. Therefore, grazing capacity is not increased by common-use grazing of the 2 animals. Both mule deer and elk herds have been increasing on our study area. Therefore, if use of common forage species is kept at moderate levels on southwestern woodland rangelands, mule deer herds can be maintained or increased when elk are present.

Protein and glucogenic precursor supplementation: A nutritional strategy to increase reproductive and economic output

The restaurant industry is the second largest employer in the United States, and restaurant demand is projected to increase in future years. In an age where more restaurants are coming into business rapidly and also going out of business steadily, there is a need to develop some operational strategies for running a restaurant successfully. This study, using quantitative survey methodology, reports responses to ratings of factors for success from current owners and operators of successful restaurants in southern New Mexico. The factors were categorized into the following domain and subdomains (a) external environment—general and specific, (b) internal environment—operational and personal, and (c) family life cycle. Means and frequencies were reported and results were grouped by means. Product served, customers, management of restaurant, as well as personal goals and philosophies had the highest overall mean response and corresponded to the most positive influence on restaurant viability. Labor market, retirement, and family issues had the lowest means corresponding to a neutral effect on restaurant success. A new hypothesized weighted model for variables leading to restaurant success is presented. This study can be repeated in other areas in the nation and can be redesigned to evaluate specific factors in detail. Another aspect that can be investigated is differences in opinion based on gender difference.