Graduation date: 1978

Short-term changes in the distribution, surface to 10 meters, of phytoplankton-associated trace metals (Fe, Mn, Cr, Zn, Co, Ni, and Cu) were studied in the near-shore waters off Humboldt Bay, California, through the summer of 1971. The depth distribution of phytoplankton-associated trace metals was related to local hydrography. During periods of upwelling higher concentrations of phytoplankton-associated Fe, Mn, Cr, and Zn were found at depth (10 meters) than at the surface. During periods of non-upwelling there was less stratification in their distribution. Phytoplankton-associated Cu, Go, and Ni showed no significant increase with depth during either period. The rate of change in trace metal distribution patterns of Fe, Mn, Cr, and Zn were regulated by surface wind patterns and hydrographic regimes. Again, Cu, Co, and Ni did not fluctuate in a significant fashion. The elements studied tended to fall into three ordered groups based on their behavior with respect to 1) depth distribution, 2) correlation with other metals studied, and 3) correlation with biomass indicators. The groupings were Fe, Mn, and Cr; Zn, Co, and Ni; and finally Cu. This ordering is similar to the Irving- Williams series and to the elements relative 'hardness" as a Lewis acid where Fe(III), Cr(III), and Mn(II) are considered hard Lewis acids while Zn(II), Co(II), Ni(II) and finally Cu(II) are considered borderline hard to soft Lewis acids. These properties are related to the relative affinities and selectivities of the elements for organic ligands. There also appears to be some relation between the physical (dissolved versus particulate form) and the chemical (oxidation state and ionic potential) behavior of the elements in sea water and their behavior in the phytoplankton. There was a negative correlation between most phytoplankton-associated trace metal concentrations (Fe, Mn, Cr, Zn, Co, and Ni) and biomass during non-upwelling periods and a positive correlation during upwelling periods. Copper, on the other hand, showed a positive correlation during both periods. This aberrant behavior of copper may be related to its high affinity for organic ligands and its relative softness as a Lewis acid. Since no simple negative correlation was found between phytoplankton biomass and phytoplankton-associated trace metal concentrations, biological dilution does not appear to be as important as the hydrographic regime and the chemical activities of the element in determining the concentrations of trace metals in near shore phytoplankton populations. / Graduation date: 1975

Graduation date: 1971

1S801 is a transposable element isolated from Pseudomonas syringae pathovar (pv.) phaseolicola, the causal agent of halo blight of bean. Fragments of the element are present in multiple copies on an indigenous plasmid, pMMC7105, of strain LR781, and have been implicated as sites of homologous recombination leading to imprecise excision of the chromosomally integrated form of the plasmid. The element, which has been completely sequenced, is 1512 base pairs in length and is unusual among transposable elements in that it does not have direct or inverted repeats in its termini. The terminal regions of the element were uncoupled from the two major open reading frames, and trans-acting activity of the putative transposase was demonstrated in Escherichia coli (recA). An alignment of the sequences of thirteen insertions defined the precise borders of the element, and demonstrated that it does not duplicate its targets upon insertion. The target specificity of IS801 is similar to, but more degenerate than, the target specificity of two transposable elements to which it is closely related, IS91 and IS1294. The consensus derived from the aligned target sequences is G/C-A/G-A-C/G, and the target tetramer is found immediately adjacent to the right terminus of the element upon transposition. IS91 was demonstrated to mobilize 1S801, but not with the specificity characteristic of 1S801. The structure of 1S801 and the characteristics of IS91-activated transposition of 1S801 are discussed in light of a proposed model for IS91 transposition, and it is suggested that 1S801 could have been derived from IS91 by a modification of its left end. Remnants of IS801 are present near avirulence genes of various P. syringae pathovars, suggesting that the element has been involved in genetic rearrangements in the vicinity of these loci. / Graduation date: 1996

Thesis (M.S.)--Oregon Graduate Center, 1980.

Thesis (Ph. D.)--Oregon Graduate Center, 1979.

Techniques for a posteriori error estimation for finite element approximations of an elliptic partial differential equation are studied.This extends previous work on localized error control in finite element methods for linear elasticity.The methods are then applied to the problem of homogenization of periodic structures. In particular, error estimates for the effective elastic properties are obtained. The usefulness of these estimates is twofold.First, adaptive methods using mesh refinements based on the estimates can be constructed.Secondly, one of the estimates can give reasonable measure of the magnitude ofthe error. Numerical examples of this are given.

All animals, including insect herbivores, eat to acquire nutrients that are essential for fueling physiological processes associated with growth, development, and reproduction. Protein and digestible carbohydrates are two nutrients required in large quantities by insect herbivores, but the amounts in which they occur in plants can be highly variable. In this thesis, I explore how the amounts and ratios of protein and digestible carbohydrate in an insect herbivore's food affect lifetime performance and body elemental composition. I do this by confining a generalist caterpillar, Heliothis virescens, to semi-synthetic foods with fixed protein-carbohydrate amounts and ratios. I show that foods with protein-carbohydrate ratios that match the self-selected protein-carbohydrate intake of final instar caterpillars correlate strongly with best performance, and that small deviations away from this optimal protein-carbohydrate ratio can result in large drop-offs in overall performance, particularly for males. I also show the importance of protein-carbohydrate balance over total macronutrient content. Finally, my results demonstrate that H. virescens caterpillars do not practice strict elemental homeostasis. My result, when contrasted with earlier work on caterpillars, suggests that hemimetabolous and holometabolous insect herbivores practice different degrees of elemental homeostasis.

Abstract: Alberto Ginastera is considered one of the most important composers in Argentina. His music reflects the ancient aboriginal primitivism and the nationalistic spirit of Argentine traditional music. Strong rhythm has played a significant role in his music. According to Ginastera¡¦s own criteria, his works can be divided into three periods, but only the first two periods are related to nationalistic music. The first period is called ¡§objective nationalism¡¨ (1937-1947), where folk elements are used directly in the works. The second period, called ¡§subjective nationalism¡¨ (1948-1953), is characterized by sublimated musical language. Ginastera uses new rhythmic and melodic materials that symbolize Argentine music. This thesis has four chapters besides the introduction. The time discussed in this thesis is until 1952, including Ginastera¡¦s early piano music up to his First Piano Sonata. All these compositions have the influence of the folk idiom of Argentina. The first chapter is a discussion of historical background, including the development and growth of art music in Argentine society and Ginastera¡¦s life as a composer. The second chapter focuses on the importance of the gaucho as a symbolic heritage of the indigenous folk music in Argentina and on how their music, such as malambo, gato, zamba, triste, vidala, and milonga were manifested in Ginastera¡¦s piano music. The third chapter studies Ginastera¡¦s compositional techniques and styles, including his treatment of form, phrasing, melody, harmony and tonality. This is followed by a comprehensive conclusion. Although Ginastera was not a prolific composer for the piano, his genius and creativity is shown by his outstanding skills in manipulating folkloric materials in his piano music. Ginastera¡¦s music has achieved widespread recognition and has also made a great contribution to the twentieth-century Latin-American music.

Student needs are ever changing within today??s classroom. Training elements for teachers must be adapted so that all students?? individual needs are being met. Training offered by school districts must incorporate specific social and emotional topics that deal with the gifted and talented students?? development. This research project investigated various training options that elementary teachers have received by attending a six-clock-hour workshop when compared to those teachers who received thirty hours of university course work at the university graduate level. The study then determined the specific elements of training received, the topics necessary for implementation that are of a positive nature for students, and finally, qualities that teachers must possess and implement within the classroom in order to effectively meet the needs of social and emotional development for gifted students. This study showed that training in the area of social and emotional development is crafted differently according to the trainer who is presenting the material. The respondents who were interviewed took various knowledge and applied it within the classroom based on student and professional needs. The notion that gifted students are perfect seems to be the norm of thinking in the group of teachers who were used in this case study. The strategies used for classroom implementation are ones that most likely meet the cognitive domain and can be used as a form of assessment for the teacher??s gradebook. The activities that will most likely benefit the emotional quality of a student??s psyche are viewed to be ones that are not beneficial or easily implemented within the constraints of the classroom. The need for social and emotional development is demonstrated by the vast amount of research and models as presented throughout this study. The study shows that much training is needed along with a classroom structure that is designed to help gifted students learn to deal with their intellect as well as with factors that seem to interrupt the intellectual label.