University of Missouri

About: University of Missouri is a education organization based out in Columbia, Missouri, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 41427 authors who have published 83598 publications receiving 2911437 citations. The organization is also known as: Mizzou & Missouri-Columbia.

Growth of the Maize Primary Root at Low Water Potentials : III. Role of Increased Proline Deposition in Osmotic Adjustment.

Abstract: Seedlings of maize (Zea mays L. cv WF9 × Mo 17) growing at low water potentials in vermiculite contained greatly increased proline concentrations in the primary root growth zone. Proline levels were particularly high toward the apex, where elongation rates have been shown to be completely maintained over a wide range of water potentials. Proline concentration increased even in quite mild treatments and reached 120 millimolal in the apical millimeter of roots growing at a water potential of −1.6 megapascal. This accounted for almost half of the osmotic adjustment in this region. Increases in concentration of other amino acids and glycinebetaine were comparatively small. We have assessed the relative contributions of increased rates of proline deposition and decreased tissue volume expansion to the increases in proline concentration. Proline content profiles were combined with published growth velocity distributions to calculate net proline deposition rate profiles using the continuity equation. At low water potential, proline deposition per unit length increased by up to 10-fold in the apical region of the growth zone compared to roots at high water potential. This response accounted for most of the increase in proline concentration in this region. The results suggest that osmotic adjustment due to increased proline deposition plays an important role in the maintenance of root elongation at low water potentials.

The Questionnaire for Eudaimonic Well-Being: Psychometric properties, demographic comparisons, and evidence of validity

Abstract: The Questionnaire for Eudaimonic Well-Being (QEWB) was developed to measure well-being in a manner consistent with how it is conceptualized in eudaimonist philosophy. Aspects of eudaimonic well-being assessed by the QEWB include self-discovery, perceived development of one's best potentials, a sense of purpose and meaning in life, intense involvement in activities, investment of significant effort, and enjoyment of activities as personally expressive. The QEWB was administered to two large, ethnically diverse samples of college students drawn from multiple sites across the United States. A three-part evaluation of the instrument was conducted: (1) evaluating psychometric properties, (2) comparing QEWB scores across gender, age, ethnicity, family income, and family structure, and (3) assessing the convergent, discriminant, construct, and incremental validity of the QEWB. Six hypotheses relating QEWB scores to identity formation, personality traits, and positive and negative psychological functioning were evaluated. The internal consistency of the scale was high and results of independent CFAs indicated that the QEWB items patterned onto a common factor. The distribution of scores approximated a normal curve. Demographic variables were found to predict only small proportions of QEWB score variability. Support for the hypotheses tested provides evidence for the validity of the QEWB as an instrument for assessing eudaimonic well-being. Implications for theory and future research directions are discussed.

Electronic structure and thermoelectric properties of bismuth telluride and bismuth selenide

Abstract: The electronic structures of the two thermoelectric materials and are studied using density-functional theory with the spin - orbit interaction included. The electron states in the gap region and the chemical bonding can be described in terms of interaction between the atomic p orbitals within the `quintuple' layer. For , we find both the valence-band maximum as well as the conduction-band minimum, each with a nearly isotropic effective mass, to occur at the zone centre in agreement with experimental results. For , we find that the six valleys for the valence-band maximum are located in the mirror planes of the Brillouin zone and they have a highly anisotropic effective mass, leading to an agreement between the de Haas - van Alphen data for the p-doped samples and the calculated Fermi surface. The calculated conduction band, however, has only two minima, instead of the six minima indicated from earlier experiments. The calculated Seebeck coefficients for both p-type and n-type materials are in agreement with the experiments.