Overexpression of beta-carotene hydroxylase enhances stress tolerance in Arabidopsis

Plant stress caused by extreme environmental conditions is already a principal reason for yield reduction in crops. The threat of global environment change makes it increasingly important to generate crop plants that will withstand such conditions. Stress, particularly stress caused by increased sunlight, leads to the production of reactive oxygen species that cause photo-oxidative cell damage. Carotenoids, which are present in the membranes of all photosynthetic organisms, help protect against such light-dependent oxidative damage. In plants, the xanthophyll cycle (the reversible interconversion of two carotenoids, violaxanthin and zeaxanthin) has a key photoprotective role and is therefore a promising target for genetic engineering to enhance stress tolerance. Here we show that in Arabidopsis thaliana overexpression of the chyB gene that encodes -carotene hydroxylase—an enzyme in the zeaxanthin biosynthetic pathway—causes a specific twofold increase in the size of the xanthophyll cycle pool. The plants are more tolerant to conditions of high light and high temperature, as shown by reduced leaf necrosis, reduced production of the stress indicator anthocyanin and reduced lipid peroxidation. Stress protection is probably due to the function of zeaxanthin in preventing oxidative damage of membranes

As-built specification for CLASSY conversion

There are no author-identified significant results in this report

The why's the limit: curtailing self-enhancement with explanatory introspection

Self-enhancement is linked to psychological gains (e.g., subjective well-being, persistence in adversity) but also to intrapersonal and interpersonal costs (e.g., excessive risk taking, antisocial behavior). Thus, constraints on self-enhancement may sometimes afford intrapersonal and interpersonal advantages. We tested whether explanatory introspection (i.e., generating reasons for why one might or might not possess personality traits) constitutes one such constraint. Experiment 1 demonstrated that explanatory introspection curtails self-enhancement. Experiment 2 clarified that the underlying mechanism must (a) involve explanatory questioning rather than descriptive imagining, (b) invoke the self rather than another person, and (c) feature written expression rather than unaided contemplation. Finally, Experiment 3 obtained evidence that an increase in uncertainty about oneself mediates the effect

JSU Writing Project Anthology | Summer 2005

Theme: Stepping into the Spotlight as Teachers, as Writers, as Leadershttps://digitalcommons.jsu.edu/eng_writ_proj_anth/1017/thumbnail.jp

JSU Writing Project Anthology | Summer 1997

https://digitalcommons.jsu.edu/eng_writ_proj_anth/1009/thumbnail.jp

A Study to Determine whether the Advantages Gained in the Eight Week Summer Head Start Program in Carter County Continued through Second Grade

A thesis presented to the faculty of the School of Education at Morehead State University In partial fulfillment of the requirements for the Degree of Master of Arts in Education by Madeline P. Horton in May of 1968

JSU Writing Project Anthology | Summer 2005

Theme: Stepping into the Spotlight as Teachers, as Writers, as Leadershttps://digitalcommons.jsu.edu/eng_writ_proj_anth/1017/thumbnail.jp

Laminar separation bubbles in two and three dimensional incompressible flow.

PhDA theoretical and experimental study is made of the closed 'bubbles` of separated flow formed when a laminar boundary layer separates from an aerofoil surface and, after undergoing transition to turbulence, subsequently re-attaches. Attention is mainly confined to the so-called 'short' type of bubble, which is distinguished from the 'long' type by its relatively slight overall effect upon the pressure distribution. In Part I, a semi-empirical theory for the prediction of the growth and bursting of two-dimensional short bubbles is developed. The existing data concerning short bubbles are re-examined, with particular emphasis upon the conditions governing re-attachment. A criterion for the determination of turbulent re-attachment is proposed, and approximate quadrature methods developed for the calculation of the momentum thickness in the separated region. These results, together with am empirical formula for the determination of the position of transition, are combined with a simplified model of the pressure distritbution in the bubble region to predict the re-attachment position. It is found that, for a given imposed pressure distribution, there exists a Reynolds number at separation below which re-attachment is impossible. This is associated with the phenomenon of short bubble bursting. The predictions of the theory are in reasonable quantitative agreement with experiment. Part II deals with bubbles in three-dimensional flow. Experiments are described in which separation bubbles were produced using an apparatus closely simulating conditions near the leading-edge of a swept wing of infinite span. Measurements of surface pressure, mean velocity and turbulence level are presented, from which it is deduced that the bubble structure is similar to that of two-dimensional bubbles, apart from the existence of cross-flows in the shear-layer and a strong spanwise flow in the reverse-flow vortex. An extension of the two-dimensional bursting theory by means of the independence principle is in reasonable agreement with measured bursting parameters.Ministry of Technolog

Alien Registration- Hayes, Horton P. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/24531/thumbnail.jp