David C. Blouin

Memory bias for fatness stimuli in the eating disorders.

This investigation studied the presence of a memory bias for words connoting fatness in persons diagnosed with an eating disorder. Eating disorder subjects were compared to a nonsymptomatic control group and to a symptomatic (weight-preoccupied) control group. A memory bias for fatness words in eating disorder patients was found. There was no evidence for a memory bias in either group of control subjects, i.e., those who were preoccupied with body size and shape nor those without extreme preoccupation. The three groups did not differ in the recall of nonfat or neutral words. These results were interpreted as evidence in support of the hypothesis that activating self-schemata in eating disorder patients results in a recall bias for fat-related stimuli.

Body-image disturbances in bulimia nervosa: Influences of actual body size.

This study evaluated body-image distortion and ideal body-size preferences in 423 nonbulimic women and 108 bulimics. Analyses of covariance were utilized to compare the bulimic and nonbulimic groups on measures of current and ideal body size. Weight was used as a covariate to evaluate the influence of actual body size on perception of current body size and selection of ideal body size. Bulimics chose current body sizes that were significantly larger than those picked by nonbulimics regardless of actual body size. Bulimics also chose thinner ideal body sizes than did nonbulimics, regardless of actual body size. These results suggest that body-image distortion and extreme preference for thinness are a fundamental characteristic of bulimia nervosa. These results were discussed in terms of how perception of a large body size and preference for a very thin body size might interact to produce a high degree of dissatisfaction and overconcern with body size in bulimia nervosa.

On the Analysis of Combined Experiments

Abstract The replication of experiments over multiple environments such as locations and years is a common practice in field research. A major reason for the practice is to estimate the effects of treatments over a variety of environments. Environments are frequently classed as random effects in the model for statistical analysis, while treatments are almost always classed as fixed effects. Where environments are random and treatments are fixed, it is not always necessary to include all possible interactions between treatments and environments as random effects in the model. The rationale for decisions about the inclusion or exclusion of fixed by random effects in a mixed model is presented. Where the effects of treatments over broad populations of environments are to be estimated, it is often most appropriate to include only those fixed by random effects that reference experimental units.

Fenoxaprop Interactions for Barnyardgrass (Echinochloa crus-galli) Control in Rice1

A study was conducted in 2000 and 2001 to evaluate interaction of fenoxaprop with other herbicides for barnyardgrass control in rice. Changes in herbicide interaction over time were also evaluated, and herbicide combinations were ranked on the basis of compatibility. Fenoxaprop at 0.075 kg/ha plus bentazon or propanil plus molinate resulted in an additive response for barnyardgrass control at 10, 20, and 30 d after treatment (DAT); however, when the rate of fenoxaprop increased to 0.089 kg/ha, an antagonistic effect was found. Carfentrazone and halosulfuron consistently antagonized the activity of fenoxaprop at both rates on barnyardgrass. Bensulfuron at 10 and 20 DAT and triclopyr at 20 DAT were antagonistic to fenoxaprop. An increase in interaction over time was detected when fenoxaprop at 0.089 kg/ha was applied in mixture with carfentrazone at 0.04 kg/ha or halosulfuron at 0.05 kg/ha. These results indicate that propanil plus molinate and bentazon are more compatible with fenoxaprop at 0.075 kg/ha for barnyardgrass control, whereas bensulfuron, carfentrazone, halosulfuron, and triclopyr can antagonize fenoxaprop activity on barnyardgrass. Nomenclature: Bensulfuron; bentazon; carfentrazone; fenoxaprop; halosulfuron; molinate; propanil; triclopyr; barnyardgrass, Echinochloa crus-galli (L.) Beauv. #3 ECHCG; rice, Oryza sativa L. ‘Cocodrie’. Additional index words: Antagonism, synergism. Abbreviations: DAT, days after treatment; NLMIXED, nonlinear mixed procedure; POST, postemergence.

Temporal stability of psychophysiological responding: a comparative analysis of mental and physical stressors.

Although extensive research has been conducted on psychophysiological reactivity, there is a paucity of data concerning the temporal stability of such procedures. Test-retest reliability of experimental stressors from both mental and physical modalities were assessed using a wide range of psychophysiological measures. Absolute baseline and test values demonstrated adequate test-retest reliability for skin temperature, skin resistance, vasomotor response, heart rate, systolic and diastolic blood pressure, while forearm EMG had low reliability. Difference scores, which represent change from baseline to test conditions, did not have adequate reliability. These data represent a necessary step towards standardization of psychophysiological assessment techniques and thus may guide further use of more reliable methods.

Analysis of Synergistic and Antagonistic Effects of Herbicides Using Nonlinear Mixed-Model Methodology1

When herbicides are applied in mixture, and infestation by weeds is less than expected compared with when herbicides are applied alone, a synergistic effect is said to exist. The inverse response is described as being antagonistic. However, if the expected response is defined as a multiplicative, nonlinear function of the means for the herbicides when applied alone, then standard linear model methodology for tests of hypotheses does not apply directly. Consequently, nonlinear mixed-model methodology was explored using the nonlinear mixed-model procedure (PROC NLMIXED) of SAS System®. Generality of the methodology is illustrated using data from a randomized block design with repeated measures in time. Nonlinear mixed-model estimates and tests of synergistic and antagonistic effects were more sensitive in detecting significance, and PROC NLMIXED was a versatile tool for implementation. Additional index words: Least significant difference, linear mixed models, repeated measures, tank mixture. Abbreviations: DAT, days after treatment; GH, glufosinate plus mixture herbicide; GHD, glufosinate plus mixture herbicide by DAT; ML, maximum likelihood; MSE, mean square error; Rep, replication.

Potential Use of Imazethapyr Mixtures in Drill-Seeded Imidazolinone-Resistant Rice

The efficacy of imazethapyr in drill-seeded imidazolinone-resistant rice was evaluated in Louisiana in 2000 and 2001. Imazethapyr was applied preemergence (PRE), or no PRE, followed by a postemergence (POST) application of imazethapyr alone, or in a mixture with bensulfuron, bentazon plus aciflurofen, carfentrazone, halosulfuron, propanil plus molinate, triclopyr, or V-10029. Imazethapyr applied PRE followed by a POST application of imazethapyr controlled barnyardgrass equivalent to or higher than other treatments evaluated. Red rice control at 35 days after postemergence treatment (DAT) was 66 to 81% with imazethapyr applied PRE followed by any POST application, but a reduction in control was observed with a POST application of imazethapyr. Although alligatorweed control increased with POST applications, these treatments suggested only suppression. Hemp sesbania control never exceeded 10% with imazethapyr-only treatments and at 35 DAT, all POST applications, except bensulfuron, increased control above 84%. Rice yield increased with treatments receiving a PRE application of imazethapyr compared with no imazethapyr applied PRE. Nomenclature: Acifluorfen; bensulfuron; bentazon; carfentrazone; halosulfuron; imazethapyr; molinate; propanil; V-10029, sodium 2,6-bis[(4,6-dimethoxypyrimidin-2-yl)oxy]benzoate; alligatorweed, Alternanthera philoxeroides (Mart.) Griseb. #3 ALRPH; barnyardgrass, Echinochloa crus-galli (L.) Beauv. # ECHCG; hemp sesbania, Sesbania exaltata (Raf.) Rydb. ex A.W. Hill # SEBEX; red rice, Oryza sativa L. # ORYSA; rice, Oryza sativa L. imidazolinone-resistant ‘93 AS-3510’ and ‘CL 121’. Additional index words: Acetolactate synthase; Clearfield rice, herbicide mixtures. Abbreviations: ALS, acetolactate synthase (EC 4.1.3.18); DAT, days after postemergence treatment; IR, imidazolinone-resistant; POST, postemergence; PPI, preplant incorporated; PRE, preemergence.

Criterion-related validity of a role-play social skills test for children

The social skills/competence of 104 second- and sixth-grade students was assessed using a role-play test for social skill and four measures of social competence, i.e., two peer ratings, teacher ratings, and self-report. Simple correlational analyses replicated earlier findings of very low correlations between specific role-play behavior and measures of social competence. As a test of criterion-related validity, multivariate analyses using canonical correlations indicated significant, moderate magnitude canonical correlations between response profiles of the role-play test and the criterion variables. These data were discussed in terms of the complexity of assessing social skill and competence. In particular, it was concluded that the person evaluating social competency situational factors and age of the child were important considerations for evaluating the adequacy of social behavior.

Differential Tolerance of Rice (Oryza sativa) Varieties to Clomazone

Tolerance of nine rice varieties to clomazone at 1.12 kg ai/ha was evaluated from 2000 to 2002. Rice injury was 27 to 51% at 14 d after treatment (DAT) and reduced to 5 to 30% at 42 DAT with long-grain ‘Drew’ having less injury compared with all medium-grain varieties. Medium- grain ‘Earl’ and ‘LL-401’ were injured most compared with all other varieties at 42 DAT. Plant height was reduced by clomazone with all varieties except Drew at 34 DAT. Clomazone also reduced plant population of Earl, LL-401, and ‘Wells’, but other varieties were not affected at 34 DAT. However, rice grain yield reduction was only observed with LL-401. These results indicate that differential tolerance to clomazone exists among rice varieties. Nomenclature: Clomazone; rice, Oryza sativa L. ‘Bengal’, ‘Cocodrie’, ‘Cypress’, ‘Drew’, ‘Earl’, ‘CL-141’, ‘LL-401’, ‘LL-601’, ‘Wells’. Additional index words: Herbicide tolerance. Abbreviations: DAT, days after treatment; DPRE, delayed preemergence; PPI, preplant incorporated; PRE, preemergence.

The Roles of Labor and Profitability in Choosing a Grazing Strategy for Beef Production in the U.S. Gulf Coast Region

Comparisons are made concerning labor required and profitability associated with continuous grazing at three stocking rates and rotational grazing at a high stocking rate in the U.S. Gulf Coast region. A unique data set was collected using a time and motion study method to determine labor requirements. Profits are lowest for low stocking rate– continuous grazing and high stocking rate–rotational grazing. Total labor and labor in three specific categories are greater on per acre and/or per cow bases with rotational-grazing than with continuous-grazing strategies. These results help to explain relatively low adoption rates of rotational grazing in the region.