Digital Commons Network^™

Leader-Member Exchange And Supervisor Career Mentoring As Complementary Constructs In Leadership Research, Terri Scandura

Terri A. Scandura

No abstract provided.

The Forms And Limits Of Medical Ethics, Barry Hoffmaster

C. Barry Hoffmaster

As medical ethics has evolved over the past several decades, it has come to be regarded as a domain of applied ethics, that is, the application of a rationally based, philosophical theory to moral problems in health care. But an array of difficulties arise in the attempt to apply general moral theories or norms to concrete problems, difficulties that expose the incompleteness and indeterminacy of philosophical moral theory. The doubtful ability of applied ethics to be practically helpful has led to the development of two main competitors. One is the attempt to reprise and rehabilitate the tradition of moral casuistry, …

Molecular Genetic Analysis Of Terminal Steps In Bacteriochlorophyll A Biosynthesis: Characterization Of A Rhodobacter Capsulatus Strain That Synthesizes Geranylgeranoil-Esterified Bacteriochlorophyll A, David Bollivar, Shaojie Wang, James P. Allen, Carl E. Bauer

David Bollivar

Site-directed mutational analysis of the Rhodobacter capsulatus photosynthesis gene cluster was undertaken in order to identify and characterize genetic loci involved in bacteriochlorophyll a biosynthesis. A mutant in orf304 was shown to accumulate the tetrapyrrole intermediate "bacteriochlorophyllide a" which is a tetrapyrrole that has a bacteriochlorophyll a ring structure without the presence of an esterifying alcohol. A mutant in orf391 is shown to synthesize acteriochlorophyll a that is esterified with geranylgeraniol rather than the normal phytol. This latter result provides the first genetic confirmation that esterification of bacteriochlorophyllide a initially involves the addition of a geranylgeraniol group followed by sequential …

Biomedical Ethics In A Canadian Context, Charles Weijer

Charles Weijer

No abstract provided.

Factors Affecting The Abundance Of Juvenile Fish Species On A Temperate Artificial Reef, Daniel Pondella, John Stephens

Daniel Pondella

In contrast to most artificial reefs which are placed at relatively deep depths so as not to interfere with shipping, rocky breakwaters provide important habitat in the intertidal-shallow subtidal zone. This zone is especially preferred for recruitment by many rocky shore fishes. The breakwaters of King Harbor, Redondo Beach, California enhance this zone. Further, the lee of the outer breakwater provides a stable, quiet water area for numerous Young-of-Year (YOY) fishes. By means of SCUBA we monitored YOY abundance from 1986-1990. During these five years there were dramatic natural and anthropogenic disturbances of the habitat. With little inter-annual variation of …

Heterologous Expression Of The Bchm Gene Product From Rhodobacter Capsulatus And Demonstration That It Encodes S-Adenosyl-L-Methionine: Mg-Protoporhyrin Ix Methyltransferase, David Bollivar, Ze-Yu Jiang, Carl E. Bauer, Samuel I. Beale

David Bollivar

The bacteriochlorophyll biosynthesis gene, bchM, from Rlodobacter capsulatus was previously believed to code for a polypeptide involved in formation of the cyclopentone ring of protochlorophyllide from Mg-protoporphyrin IX monomethyl ester. In this study, R. capsulatus bchM was expressed in Escherichia coli and the gene product was subsequently demonstrated by enzymatic analysis to catalyze methylation of Mg-protoporphyrin IX to form Mg-protoporphyrin IX monomethyl ester. Activity required the substrates Mg-protoporphyrin IX and S-adenosyl-L-methionine. 14C-labeled product was formed in incubations containing 14C-methyl-labeled S-adenosyl-L-methionine. On the basis of these and previous results, we also conclude that the bchH gene, which was previously reported to …

Investigation Of The Charge Transfer Properties Of Electrodes Modified By The Spontaneous Adsorption Of Unsymmetrical Dialkyl Sulfides, Minhui Zhang, Mark Anderson

Mark R. Anderson

Electrodes modified by the spontaneous adsorption of unsymmetrical dialkyl sulfides are used to investigate two monolayer properties, structural disorder and solvent compatibility, that may be of importance in determining the ability for faradaic charge transport to occur in the presence of the monolayer. Two groups of dialkyl sulfides are prepared and studied: a purely hydrocarbon dialkyl sulfide with the structure CH3(CH2)17S(CH2)nCH3, where n, = 7,9, and 17, and an acid containing dialkyl sulfide with the structure CH3(CH2)17S(CH2)mCOOH, where m = 7, 10, and 15. Reflection infrared spectroscopy of the hydrocarbon dialkyl sulfide reveals that the monolayer structure is disordered, when …

Redistribution Of Insoluble Interphotoreceptor Matrix Components During Photoreceptor Differentiation In The Mouse Retina, Kristina Mieziewska, Agoston Szel, Theo Van Veen, Gustavo D. Aguirre, Nancy Philp

Gustavo D. Aguirre, VMD, PhD

Effect Of Applied Potential Upon The In Situ Structure Of Self-Assembled Monolayers On Gold Electrodes, Mark Anderson, Marilyn Gatin

Mark R. Anderson

Polarization modulation Fourier transform infrared reflection absorption spectroscopy (PM-FTIRRAS) has been utilized to study the in situ structure of octadecanethiol when adsorbed to gold electrode surfaces and with the application of potential to the substrate. It is found that applied potential has little effect upon the spectrum of the monolayer in the presence of D2O solutions containing 0.10 M NaClO4. The presence of an acetonitrile solution contacting the monolayer leads to small changes in the infrared spectrum relative to that seen in D2O solutions, suggestive of some small disordering of the monolayer caused by the presence of the acetonitrile. With …

Application Of The Quartz Crystal Microbalance To Characterize The Interaction Of Solutes With Modified Interfaces, John Roush, David Thacker, Mark Anderson

Mark R. Anderson

Piezoelectric quartz crystals, modified by the spontaneous adsorption of either 4-aminothiophenol or octadecanethiol, were utilized to investigate the selective interactions that exist between solutes and the surface modification layer. It is found that the exposed amine functionality of the 4-aminothiophenol monolayer increases the sensitivity of the quartz crystal microbalance to phenols relative to the response found at either a crystal modified with an octadecanethiol monolayer or an unmodified quartz crystal. Protonation of the amino group decreases the sensitivity of the 4-aminothiophenol modified crystal toward the phenol solutes, to a level approximately the same as seen for the octadecanethiol monolayer and …

Momento Mori, Charles Weijer

Charles Weijer

No abstract provided.

S-Thiolation Of Individual Human Neutrophil Proteins Including Actin By Stimulation Of The Respiratory Burst: Evidence Against A Role For Glutathione Disulfide, Yuh-Cherng Chai, S. Ashraf, R. Johnson, James Thomas

Yuh-Cherng Chai

Protein S-thiolation, a reversible modification of protein sulfhydryls resulting in formation of mixed-disulfides, was studied in human neutrophils stimulated with phorbol diester to produce superoxide anion. Rapid S-thiolation of several proteins was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Glutathione was identified as the primary protein-bound thiol by HPLC chromatography, contributing considerably more than 85% of the total. Minor amounts of homocysteine and/or cysteine were also detected as protein-bound thiols. During the first 30 min after stimulation, 10% of the cellular glutathione became protein bound (2 nmol/mg of protein). There was no increase in glutathione disulfide suggesting that S-thiolation of …

Heterochronic Genes And The Temporal Control Of C. Elegans Development, Victor Ambros, Eric Moss

Victor R. Ambros

The heterochronic genes of Caenorhabditis elegans encode part of a regulatory system that controls the temporal component of cell fates in development. The genes have been characterized genetically and molecularly, and their study has so far revealed a genetic hierarchy that specifies sequences of developmental events, a novel RNA-mediated mechanism of gene regulation and a reprogramming phenomenon associated with arrested development.

Irreversible Steps In The Ferritin Synthesis Induction Pathway.., L. Linggoess, David Mascotti, M. Bhattacharyya-Pakrasi, H. Gang, R. Thach

David P. Mascotti

The ability of cells to re-repress ferritin synthesis after removal of an inducing agent (iron or heme) was investigated. Re-repression was found to be a slow process, requiring approximately 4 (after iron removal) to 10 h (after heme removal) for completion. Desferrioxamine mesylate (Desferal) had only a slight effect on the rate of re-repression, whereas cycloheximide was strongly inhibitory, indicating that new protein synthesis is required for re-repression. Re-repression occurred at a slow but significant rate in the presence of both Desferal and cycloheximide. These results indicate that, in the absence of an iron chelator, the induction of ferritin synthesis …

6li And 15n Nuclear Magnetic Resonance Studies Of Mixed Alkali Metal Cation Hexamethyldisilazide Bases, Michael Nichols, Delia Waldmüller, Paul Williard

Michael A Nichols

No abstract provided.

Plasma Lipid Changes In Prcd-Affected And Normal Miniature Poodles Given Oral Supplements Of Linseed Oil. Indications For The Involvement Of N-3 Fatty Acids In Inherited Retinal Degenerations, Robert E. Anderson, Maureen B. Maude, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Water Potentials For Developing Cladodes And Fruits Of A Succulent Plant, Including Xylem-Versus-Phloem Implications For Water Movement, P. Nobel, J. Andrade, N. Wang, Gretchen North

Gretchen North

Developing cladodes had lower water potentials and developing fruits had higher water potentials than the underlying cladodes of the widely cultivated prickly pear cactus, Opuntia ficus-indica. The 0.06 MPa lower value in 4-week-old daughter cladodes indicated a typical water potential gradient from the underlying clad-ode along the xylem of −0.2 MPa m−1; the 0.17 MPa higher value in 4-week-old fruits, which decreased to 0.07 MPa by 10 weeks, implicated the phloem as their supplier of water. The phloem sap of the underlying cladodes had an osmotic pressure of only 0.90 to 0.98 MPa, so the phloem could supply a relatively …

S-Thiolation And Irreversible Oxidation Of Sulfhydryls On Carbonic Anhydrase Iii During Oxidative Stress: A Method For Studying Protein Modification In Intact Cells And Tissues, C. Lii, Yuh-Cherng Chai, W. Zhao, James Thomas, S. Hendrich

Yuh-Cherng Chai

No abstract provided.

The Effects Of Metropolitan Job Growth On The Size Distribution Of Family Income, Timothy Bartik

Timothy J. Bartik

No abstract provided.

Changes In Root Hydraulic Conductivity For Two Tropical Epiphytic Cacti As Soil Moisture Varies, Gretchen North, P. Nobel

Gretchen North

The tropical epiphytic cacti Epiphyllum phyllanthus and Rhipsalis baccifera experience extreme variations in soil moisture due to limited soil volumes and episodic rainfalls. To examine possible root rectification, whereby water uptake from a wet soil occurs readily but water loss to a dry soil is minimal, responses of root hydraulic conductivity (Lp) to soil drying and rewetting were investigated along with the underlying anatomical changes. After 30 d of soil drying, Lp decreased 50%-70% for roots of both species, primarily because increased suberization of the periderm reduced radial conductivity. Sheaths composed of soil particles, root hairs, and mucilage covered young …

Hexagons And Squares In A Passive Nonlinear Optical System, John Geddes, R.A. Indik, J.V. Moloney, Willie Firth

John B. Geddes

Pattern formation is analyzed and simulated in a nonlinear optical system involving all three space dimensions as well as time in an essential way. This system, counterpropagation in a Kerr medium, is shown to lose stability, for sufficient pump intensity, to a nonuniform spatial pattern. We observe hexagonal patterns in a self-focusing medium, and squares in a self-defocusing one, in good agreement with analysis based on symmetry and asymptotic expansions.

Change In Eastern Europe, Robert Weiner

Robert Weiner

An up-to-date examination of the causes and consequences of the East European Revolutions of 1989.

Cladode Development For Opuntia Ficus-Indica (Cactaceae) Under Current And Doubled Co2 Concentrations, Gretchen North, T.L. Moore, P.S. Nobel

Gretchen North

Morphological and anatomical changes for first-order daughter cladodes (flattened stem segments) of a prickly pear cactus, Opuntia ficus-indica, were monitored to determine the effects of a doubled atmospheric CO2 concentration on their development and mature form. For daughter cladodes developing in controlled environment chambers for 60 d, maximal elongation rates were similar under a photosynthetic photon flux density (PPFD) of 6 mol m-2 d-1 and a CO2 concentration of 370 μl liter-1, an increased PPFD (10 mol m-2 d-1), and an increased PPFD and a doubled CO2 concentration. These maximal rates, however, occurred at 20, 15, and 12 d, respectively. …

Decreased Opsin Mrna And Immunoreactivity In Progressive Rod-Cone Degeneration (Prcd): Cytochemical Studies Of Early Disease And Degeneration, Jun Huang, Marie-Françoise Chesselet, Gustavo Aguirre

Gustavo D. Aguirre, VMD, PhD

Discipline Through Delegation: Solving The Problem Of Congressional Housecleaning, Laura K. Ray

Laura K. Ray

No abstract provided.