38 research outputs found
The Impact of Parenthetical Phrases on Interviewers’ and Respondents’ Processing of Survey Questions
Many surveys contain sets of questions (e.g., batteries), in which the same phrase, such as a reference period or a set of response categories, applies across the set. When formatting questions for interviewer administration, question writers often enclose these repeated phrases in parentheses to signal that interviewers have the option of reading the phrase. Little research, however, examines what impact this practice has on data quality. We explore whether the presence and use of parenthetical statements is associated with indicators of processing problems for both interviewers and respondents, including the interviewer’s ability to read the question exactly as worded, and the respondent’s ability to answer the question without displaying problems answering (e.g., expressing uncertainty). Data are from questions about physical and mental health from 355 digitally recorded, transcribed, and interaction-coded telephone interviews. We implement a mixed-effects model with crossed random effects and nested and crossed fixed effects. The models also control for some respondent and interviewer characteristics. Findings indicate respondents are less likely to exhibit a problem when parentheticals are read, but reading the parentheticals increase the odds(marginally significant) that interviewers will make a reading
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High-power microwave radiation as an alternative insect control method for stored products.
ABSTRACT Insect mortality studies were performed with a high-power microwave source operating at a frequency of 10.6 GHz at power levels of 9-20 kW to irradiate samples of soft wite wheat, Triticum aestivum (L.), infested with maize weevil, Sitophilus zeamais Motschul-sky, and ground wheat infested with red flour beetle, Tribolium castaneum (Herbst). These pests are common internal and external feeders in stored products, respectively. Samples at various age intervals from egg to adult were exposed. The results support the hypothesis that the insect-to-host dissipation ratio increases at frequencies >2.45 GHz. Mean mortalities 93% occurred for all ages of S. zeamais and 94% for adults and larvae of T. castaneum for mean specific input energies of 51 J/g and 53 J/g, respectively, indicating that S. zeamais is more susceptible. Extrapolating the results to the cost of treating the product in bulk volume at a busbar electric energy cost of 0.056 per bushel of wheat infested with S. zeamais to $0.139 per hundred weight of ground wheat infested with T. castuneum
Life History of Innnature \u3ci\u3eLyctocoris campestris\u3c/i\u3e (Hemiptera: Anthocoridae): Effects of Constant Temperatures and Relative Humidities
Life history of immature Lyctocoris campestris (F.), a predator of stored-product insects, was investigated at 17, 21, 25, and 29°C and =43, =58, and =75% RH in the laboratory. Most life history traits of L. campestris were influenced by temperature, but none of the traits was influenced by relative humidity. The egg incubation period was =7 d at 25- 29°C, but increased sharply at temperatures \u3c25°C. An equation was developed to predict egg incubation period over a range of temperatures. Egg hatch rate did not vary with temperatures nor with the relative humidities. The mean hatch rate ranged from 78 to 86% across different temperatures summed across 3 relative humidities. The instar-specific nymphal development also varied with temperature. The 2nd stadium was the shortest followed by the 3rd, 1st, and the 4th, and the 5th stadium was the longest across all 4 temperatures. However, the ratios of duration of nymphal stadia remained constant across all 4 temperatures tested. Total nymphal durations were 20.5, 27.6, 40.1, and 66.2 d at 29,25,21, and 1~C, respectively; all 4 were significantly different from one another. The relationships between temperature and instar-specific nymphal durations and total nymphal durations were described by the same equation for both females and males; total nymphal durations did not vary with sex. Nymphal survival rates ranged from 0.60 to 1.00 and did not vary significantly with temperature or relative humidity. Sex ratio (proportion of males) of emerging adults ranged from 0.40 to 0.70, but did not differ from 1:1. These life history data are reported in a manner useful for developing a computer model for simulating L. campestris population dynamics