Physical Sciences and Mathematics Commons^™

Responses Of Problematic Cyanobacteria To Exposures Of Copper Containing Algaecides, O'Niell Tedrow

All Theses

Cyanobacteria (blue-green algae) are associated with production of potent hepatotoxins (Microcystis; microcystin) and dense surface and benthic mats (Lyngbya), which impede critical water resource usages. Water resource managers are in need of effective and efficient treatment techniques for these problematic algae in field situations. Applications of algaecides are considered in situations where algal problems become acute or when critical water usages are threatened. However, laboratory data are needed that accurately predict responses of algae prior to field-scale algaecide applications. Site water and algae were used in laboratory algal toxicity experiments to predict responses of the target alga following an algaecide …

The Future Of Mineral Development On Federal Lands In The United States, John D. Leshy

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

11 pages.

Includes bibliographical references

"Outline of presentation of John D. Leshy, Harry D. Sunderland Distinguished Professor, U.C. Hastings College of the Law, Natural Resources Law center, June 7, 2007" (pp. 3-5)

"Leshy draft 4.27.07 For Natural Resources Law Center" (pp. 6-13)

Doping Golden Buckyballs: Cu@Au16- And Cu@Au17- Cluster Anions, Lei-Ming Wang, Satya S. Bulusu, Hua-Jin Zhai, Xiao Cheng Zeng, Wang

Xiao Cheng Zeng Publications

The discovery of the unique catalytic effects of gold nanoparticles on oxide substrates[1] has stimulated a flurry of research into the structures and properties of free gold nanoclusters, which may hold the key to elucidating the catalytic mechanisms of supported gold clusters. One of the most remarkable results has been the discovery of planar gold cluster anions (Au_n^-) of up to twelve gold atoms and the 2D to 3D transition for clusters with n larger than 12.[2]– [4] Among larger gold clusters, Au₂₀ has been found to be a perfect tetrahedron.[5] A more recent study of …

Energy Pathways And Directionality In Deformation Twinning, S. Kibey, J. B. Liu, Duane D. Johnson, H. Sehitoglu

Duane D. Johnson

We present ab initiodensity functional theory calculations of twinning energy pathways for two opposite twinning modes, (111)[112¯] and (111)[1¯1¯2], in fcc materials to examine the directional nature of twinning which cannot be explained by classical twin nucleationmodels or the “twinnability” criterion. By accounting for these energy pathways in a multiscale model, we quantitatively predict the critical twinning stress for the (111)[1¯1¯2] mode to be substantially higher compared to the favorable (111)[112¯] mode (whose predicted stresses are in agreement with experiment), thus, ruling out twinning in the (111)[1¯1¯2] mode.

Copper And Zinc Tolerance Of Two Tropical Microalgae After Copper Acclimation, Hilary L. Johnson, Jenny L. Stauber, Merrin Adams S, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Current toxicity tests with microalgae are often criticized as being overly sensitive to metals because algae are cultured in metal-deficient media. If such bioassays overestimate copper toxicity in surface waters, the relevance of water quality guidelines derived from these tests is questionable. In this study, the effect of acclimation to copper at environmentally relevant concentrations, on the sensitivity of the marine diatom Nitzschia closterium and the freshwater green alga Chlorella sp. to copper and zinc was examined. N. closterium was acclimated in culture medium containing 5 or 25 g Cu L-1 for 200 days, while Chlorella sp. was acclimated in …

The Importance Of Slime: Does Living In A Community Matrix Save Algal Cells From The Toxic Effects Of Copper?, Jacqueline Levy, Dianne F. Jolley, Jenny L. Stauber

Faculty of Science - Papers (Archive)

Microscopic algae are often used to assess the toxic effects of chemicals to the environment. They are good indicators of ecosystem health because they form the basis of the aquatic food chain and many algal species are sensitive to metals, like copper, at concentrations which occur naturally in the environment. Most toxicity tests with algae use planktonic species, that is, alga that live in the water as free-living species. To date, little research has been done on the toxicity of metals to attached algal species living in a community matrix known as biofilms, because of the difficulties in quantifying changes …

Sensitivity Of Marine Microalgae To Copper: The Effect Of Biotic Factors On Copper Adsorption And Toxicity, Jacqueline Levy, Jenny L. Stauber, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Microalgae are sensitive indicators of environmental change and, as the basis of most freshwater and marine ecosystems, are widely used in the assessment of risk and development of environmental regulations for metals. However, interspecies differences in sensitivity to metals are not well understood. The relationship between metal-algal cell binding and copper sensitivity of marine microalgae was investigated using a series of 72-h growth-rate inhibition bioassays and short-term (1-h) uptake studies. A range of marine algae from different taxonomic groups were screened to determine whether copper adsorption to the cell membrane was influenced by biotic factors, such as the ultrastructure of …

Multifunctional Ligands For Supramolecular Chemistry, James Kakoullis

LSU Master's Theses

Metal-organic frameworks (MOFs) are the primary focus of the Maverick research group, almost exclusively with the acac moeity. Before such MOFs can be attempted, multifunctional ligands of the appropriate geometry for the desired MOFs first must be synthesized. In this thesis, the synthesis and characterization of two new β-diketone ligands, specifically, Re(CO)₃Cl(PyacH)₂, 2.2, Pphac₃H₃, 1.23, and its oxide 3.6, are described. Also in this thesis, attempts to synthesize other new MOFs will be discussed. The MOF for which Re(CO)₃Cl(PyacH)₂, 2.2 was designed was Re(CO)₃ClCu(pyac)₂] …