967 research outputs found

    A Stalk-Clearing Attachment for Combine Corn Heads

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    The Positive Impact of Negative Feedback

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    While feedback is an essential element of performance, there is little theory explaining the effects of negative feedback. Disagreement exists as to whether negative feedback is good or bad and this impacts its use. Fortunately, control theory provides scholars with an opportunity to better understand negative feedback and the conditions necessary to support its intended function. This study examined the relationship between negative feedback and task performance in a leadership development environment. This work asserts that performance is contingent on perceived feedback usefulness, such that the relationship is stronger when feedback usefulness is high and weaker when it is low. In addition, this research led to the creation of a new instrument to measure perceptions of feedback usefulness as an antecedent of effective feedback. Results indicate positive effects of negative feedback on performance, with moderating effects of feedback usefulness on four post-feedback tasks. Analysis also demonstrated that the newly developed feedback usefulness scale demonstrates good model fit (evaluated by confirmatory factor analysis) and strong internal consistency reliability (Cronbach’s α)

    Effect of Hormodin A, a growth substance, on the rooting of cuttings

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    Florists, nurserymen and gardeners are deeply interested in recent discoveries that certain chemical compounds, when absorbed into the appropriate living plant tissues, induce or stimulate the initiation of roots. Depending on species, point of application of the chemical and various environmental conditions, roots appear on stems or leaves at points where roots do not ordinarily arise. The chemicals used have been variously designated by different investigators as growth substances (6), hormones (3), phytohormones (28) and auxins (28). When applied to the rootage of cuttings, these substances may have a wide practical use. Some of the most effective growth substances are offered to the trade under proprietary names. This bulletin deals with a series of experiments designed to test, under Iowa conditions, the efficacy of Hormodin A, a widely distributed trade product known to contain an effective growth-promoting chemical, indolebutyric acid, for the rooting of cuttings of many species and varieties of horticultural plants. The project was sponsored by the Boyce Thompson Institute for Plant Research, located at Yonkers, N. Y., under a cooperative agreement with the Iowa Agricultural Experiment Station. The study covered a period of 2 years and included tests with approximately 50 species and varieties. The immediate objectives of the research were: 1. To discover the most effective concentration of Hormodin A for the rooting of each species or variety; ~. to determine the effect of the treatment on cuttings taken at different stages of maturity; 3. to determine the reaction of cuttings taken at different seasons of the year to the treatments

    Objectively Measured Physical Activity Is Negatively Associated with Plasma Adiponectin Levels in Minority Female Youth

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    Objective. To evaluate the relationship between adiponectin and physical activity (PA) in minority female youth. Methods. Plasma adiponectin was measured in 39 females (mean age 9.2 ± 0.9 years; 30 Latina, 9 African-American; 56% overweight). PA was assessed by accelerometry. Mean minutes per day spent in daily PA (DPA) (≥3 metabolic equivalents (METs)), moderate PA (MPA)(4–7 METs), vigorous PA (VPA)(≥7 METs), and moderate-to-vigorous PA (MVPA)(≥4 METs) were calculated. The association between adiponectin and PA, controlling for age, fat weight, lean weight, and insulin sensitivity (SI) was analyzed using linear regression. Results. Adiponectin correlated with fat weight (r = −0.43, P < .01) and SI (r = 0.52, P < .01). Minutes spent in DPA (β = −0.40, P = .02), MPA (β = −0.36, P = .04), or MVPA (β = −0.37, P = .03) were predictors of adiponectin in the adjusted model. Conclusions. Higher PA levels were related to lower adiponectin levels. Potential mechanisms include upregulation of adiponectin receptors or an increase in high-molecular weight adiponectin with increasing PA

    ZnZ_n elliptic Gaudin model with open boundaries

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    The ZnZ_n elliptic Gaudin model with integrable boundaries specified by generic non-diagonal K-matrices with n+1n+1 free boundary parameters is studied. The commuting families of Gaudin operators are diagonalized by the algebraic Bethe ansatz method. The eigenvalues and the corresponding Bethe ansatz equations are obtained.Comment: 21 pages, Latex fil

    The recruitment experience of a randomized clinical trial to aid young adult smokers to stop smoking without weight gain with interactive technology

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    AbstractMultiple recruitment strategies are often needed to recruit an adequate number of participants, especially hard to reach groups. Technology-based recruitment methods hold promise as a more robust form of reaching and enrolling historically hard to reach young adults. The TARGIT study is a randomized two-arm clinical trial in young adults using interactive technology testing an efficacious proactive telephone Quitline versus the Quitline plus a behavioral weight management intervention focusing on smoking cessation and weight change. All randomized participants in the TARGIT study were required to be a young adult smoker (18–35 years), who reported smoking at least 10 cigarettes per day, had a BMI < 40 kg/m2, and were willing to stop smoking and not gain weight. Traditional recruitment methods were compared to technology-based strategies using standard descriptive statistics based on counts and proportions to describe the recruitment process from initial pre-screening (PS) to randomization into TARGIT. Participants at PS were majority Black (59.80%), female (52.66%), normal or over weight (combined 62.42%), 29.5 years old, and smoked 18.4 cigarettes per day. There were differences in men and women with respect to reasons for ineligibility during PS (p < 0.001; ignoring gender specific pregnancy-related ineligibility). TARGIT experienced a disproportionate loss of minorities during recruitment as well as a prolonged recruitment period due to either study ineligibility or not completing screening activities. Recruitment into longer term behavioral change intervention trials can be challenging and multiple methods are often required to recruit hard to reach groups.ClinicalTrials.gov Identifier NCT01199185The NHLBI funded TARGIT as part of a U01 Cooperative Agreement and as such the study design was approved. They did not have input into the data collection, analysis, or the interpretation of the data or in the writing of this report
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