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NEUTRON ACTIVATION ANALYSIS: CLINICAL AND BIOLOGICAL STUDIES OF MANGANESE

Description: From Symposium on Radioactivation Analysis and its Application to the Biological Sciences, Saclay, France, Sept. 1963. The use of neutron activation analysis for studying the metabolism of manganese in the body is discussed. Results of various clinical and biological studies of manganese metabolism are described. Some of the results indicate that pigments (melanin) in general contain high manganese concentrations and might play a role in extrapyramidal diseases. (D.L.C.)
Date: January 1, 1962
Creator: Cotzias, G.C.; Papavasiliou, P.S. & Miller, S.T.
Partner: UNT Libraries Government Documents Department

Visualization of Excitonic Structure in the Fenna-Matthews-OlsonPhotosynthetic Complex by Polarization-Dependent Two-DimensionalElectronic Spectroscopy

Description: Photosynthetic light-harvesting proceeds by the collection and highly efficient transfer of energy through a network of pigment-protein complexes. Inter-chromophore electronic couplings and interactions between pigments and the surrounding protein determine energy levels of excitonic states and dictate the mechanism of energy flow. The excitonic structure (orientation of excitonic transition dipoles) of pigment-protein complexes is generally deduced indirectly from x-ray crystallography in combination with predictions of transition energies and couplings in the chromophore site basis. Here, we demonstrate that coarse-grained excitonic structural information in the form of projection angles between transition dipole moments can be obtained from polarization-dependent two-dimensional electronic spectroscopy of an isotropic sample, particularly when the nonrephasing or free polarization decay signal rather than the photon echo signal is considered. The method provides an experimental link between atomic and electronic structure and accesses dynamical information with femtosecond time resolution. In an investigation of the Fenna-Matthews-Olson complex from green sulfur bacteria, energy transfer connecting two particular exciton states in the protein is isolated as being the primary contributor to a cross peak in the nonrephasing 2D spectrum at 400 fs under a specific sequence of polarized excitation pulses. The results suggest the possibility of designing experiments using combinations of tailored polarization sequencesto separate and monitor individual relaxation pathways.
Date: May 26, 2008
Creator: Department of Chemistry, The University of Chicago; Department of Biology, Department of Chemistry, Washington University; Fleming, Graham; Read, Elizabeth L.; Schlau-Cohen, Gabriela S.; Engel, Gregory S. et al.
Partner: UNT Libraries Government Documents Department

2011 Photosynthesis Gordon Research Conference & Seminar (June 11-17, 2011, Davidson College, Davidson, North Carolina)

Description: Photosynthesis is the biological process that converts solar energy into chemical energy. Elucidation of the mechanisms of photosynthetic energy conversion at a molecular level is fundamentally important for understanding the biology of photosynthetic organisms, for optimizing biological solar fuels production, and for developing biologically inspired approaches to solar energy conversion. The 2011 Gordon Conference on Photosynthesis will present cutting-edge research focusing on the biochemical aspects of photosynthesis, including: (1) structure, assembly, and function of photosynthetic complexes; (2) the mechanism of water splitting by PSII; (3) light harvesting and quenching; (4) alternative electron transport pathways; (5) biosynthesis of pigments and cofactors; and (6) improvement of photosynthesis for bioenergy and food production. Reflecting the interdisciplinary nature of photosynthesis research, a diverse group of invited speakers will represent a variety of scientific approaches to investigate photosynthesis, such as biochemistry, molecular genetics, structural biology, systems biology, and spectroscopy. Highly interactive poster sessions provide opportunities for graduate students and postdocs to present their work and exchange ideas with leaders in the field. One of the highlights of the Conference is a session featuring short talks by junior investigators selected from the poster presentations. The collegial atmosphere of the Photosynthesis GRC, with programmed discussion sessions as well as informal gatherings in the afternoons and evenings, enables participants to brainstorm, exchange ideas, and forge new collaborations. For the second time, this Conference will be immediately preceded by a Gordon Research Seminar on Photosynthesis (June 11-12, 2011, at the same location), with a focus on 'Photosynthesis, Bioenergy, and the Environment.' The GRS provides an additional opportunity for graduate students and postdocs to present their research, and it provides a mechanism to encourage active participation by junior scientists interested in photosynthesis and its applications.
Date: June 17, 2011
Creator: Niyogi, Prof. Krishna
Partner: UNT Libraries Government Documents Department

CHEMICAL EVOLUTION

Description: How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.
Date: June 1, 1965
Creator: Calvin, Melvin
Partner: UNT Libraries Government Documents Department

STUDIES ON THE CHEMICAL AND PHOTOCHEMICAL OXIDATION OFBACTERIOCHLOROPHYLL

Description: A simplified procedure is described for the preparation of crystalline bacteriochlorophyll from R. rubrum. The chemical dehydrogenation of bacteriochlorophyll with quinones is shown to give high yields of 2-desvinyl-2acetyl-chlorophyll a, whereas the photo-oxidation of bacteriochlorophyll results in a mixture of products of which 2-desvinyl-2acetyl-chlorophyll a is only a minor constituent. A number of interesting results have been observed spectrophotometrically during these oxidations under different reaction conditions. These observations are discussed and possible reaction mechanisms are outlined. The proton magnetic resonance spectrum of 2-desvinyl-2acetyl-chlorophyll a in deuteroacetone and the visible absorption spectra of this pigment and its magnesium-free derivative in acetone are reported. As expected, these spectra exhibit a marked resemblance to chlorophyll a and pheophytin a.
Date: June 1, 1966
Creator: Smith, John R. Lindsay & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

SPECTROSCOPIC INVESTIGATION OF THE INHIBITORY EFFECT OF FATTYACIDS ON PHOTOSYNTHETIC SYSTEMS

Description: Fatty acids have a reversible inhibitory effect on respiration and on photosynthetic action. They investigated the influence of octanoic acid on the photosynthetic bacteria Rhodopseudomonas spheroids R-26. From the spectroscopic data they conclude that a less efficient energy transfer and decoupling of the light harvesting pigment system from the energy converting reaction center is responsible for the inhibitory effect.
Date: May 1, 1971
Creator: Steffea, Hans & Calvin, Melvin.
Partner: UNT Libraries Government Documents Department

ABSORPTION CHANGES IN BACTERIAL CHROMATOPHORES. II. A NEWCHLOROPHYLL-LIKE PIGMENT FROM THE OXIDATION OF CHROMATOPHORES FROMRHODOSPIRILLUM RUBRUM

Description: Evidence is presented which points to (at least) two bound forms of bacteriochlorophyll present in chromatophores of Rhodospirillum rubrum, both of them readily converted to unbound bacteriochlorophyll (abs. max. 770 mu) when the chromatophores are extracted with acetone or ethanol. Controlled oxidation of the chromatophores with Ir(IV) or with Zn(II) and ferricyanide preferentially destroys the more strongly absorbing pigment (abs. max. 880 mu) but brings about only a slight decrease in the magnitude of the photoinduced absorption changes at 810 and 792 mu. Such oxidations yield a new pigment, absorbing at 715 mu in the aqueous preparation and, more strongly, at 680-684 mu when the pigment is extracted into organic solvents. This pigment is formed irreversibly and is therefore different from the material formed by photooxidation of chromatophores. Its visible spectrum and the spectrum of the material formed from it by acidification suggest that it is a chlorophyll-like substance, possibly derived from bacteriochlorophyll by (two-electron) oxidation of one of the dihydropyrrole rings to a pyrrole ring. Directions are given for separation of this pigment from other colored compounds present in the oxidation mixtures.
Date: October 1, 1964
Creator: Gould, Edwin S.; Kuntz Jr., Irwin D. & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

PYOMELANIN IS PRODUCED BY SHEWANELLA ALGAE BRY AND EFFECTED BY EXOGENOUS IRON

Description: Melanin production by S. algae BrY occurred during late/post-exponential growth in lactate-basal-salts liquid medium supplemented with tyrosine or phenylalanine. The antioxidant ascorbate inhibited melanin production, but not production of the melanin precursor, homogentisic acid. In the absence of ascorbate, melanin production was inhibited by the 4-hydroxyplenylpyruvate dioxygenase inhibitor, sulcotrione and Fe(II) (>0.2mM). These data support the hypothesis that pigment production by S. algae BrY was a result the conversion of tyrosine or phenylalanine to homogentisic acid which was excreted, auto-oxidized and self-polymerized to form pyomelanin. The inverse relationship between Fe(II) concentration and pyomelanin production has implications that pyomelanin may play a role in iron assimilation under Fe(II) limiting conditions.
Date: November 29, 2006
Creator: Turick, C; Frank Caccavo, F; Jr., J & Louis S. Tisa, L
Partner: UNT Libraries Government Documents Department

Field Deployment for In-situ Metal and Radionuclide Stabilization by Microbial Metabolites

Description: A novel biotechnology is reported here that was demonstrated at SRS that facilitates metal and actinide immobilization by incorporating the physiology and ecology of indigenous bacteria. This technology is based on our previous work with pyomelanin-producing bacteria isolated from SRS soils. Through tyrosine supplementation, overproduction of pyomelanin was achieved, which lead ultimately to metal and actinide immobilization, both in-vitro and in-situ. Pyomelanin is a recalcitrant microbial pigment and a humic type compound in the class of melanin pigments. Pyomelanin has electron shuttling and metal chelation capabilities and thus accelerates the bacterial reduction and/or immobilization of metals. Pyomelanin is produced outside the cell and either diffuses away or attaches to the cell surface. In either case, the reduced pyomelanin is capable of transferring electrons to metals as well as chelating metals. Because of its recalcitrance and redox cycling properties, pyomelanin molecules can be used over and over again for metal transformation. When produced in excess, pyomelanin produced by one bacterial species can be used by other species for metal reduction, thereby extending the utility of pyomelanin and further accelerating metal immobilization rates. Soils contaminated with Ni and U were the focus of this study in order to develop in-situ, metal bioimmobilization technologies. We have demonstrated pyomelanin production in soil from the Tims Branch area of SRS as a result of tyrosine amendments. These results were documented in laboratory soil column studies and field deployment studies. The amended soils demonstrated increased redox behavior and sequestration capacity of U and transition metals following pyomelanin production. Treatments incorporating tyrosine and lactate demonstrated the highest levels of pyomelanin production. In order to determine the potential use of this technology at other areas of SRS, pyomelanin producing bacteria were also quantified from metal contaminated soils at TNX and D areas of SRS. A bacterial culture collection ...
Date: September 26, 2005
Creator: Turick, C. E.; Knox, A. S.; Dixon, K. L.; Roseberry, R. J. & Kritzas, Y. G
Partner: UNT Libraries Government Documents Department

Feasibility of measuring 3He bubble diameter populations in deuterium-tritium ice layers using Mie scattering

Description: In this report, I assess the feasibility of using Mie scattering to quantify the diameter distribution of {sup 3}He bubbles in DT ice layers. Mie scattering methods are often used for He diameter m measurements of particulates in emulsions like pigments and ink products. These measurements suggests that similar techniques could be used to measure the distribution of {sup 3}He bubbles He in DT ice layers, which is important for NIF ICF capsules. To investigate the achievable performance of bubble diameter measurements using Mie scattering, I performed numerical modeling using exact analytical expressions.
Date: January 22, 2007
Creator: Izumi, N
Partner: UNT Libraries Government Documents Department

Identification of Larval Pacific Lampreys (Lampetra tridentata), River Lampreys (L. ayresi), and Western Brook Lampreys (L. richardsoni) and Thermal Requirements of Early Life History Stages of Lampreys, Annual Report 2002-2003.

Description: Two fundamental aspects of lamprey biology were examined to provide tools for population assessment and determination of critical habitat needs of Columbia River Basin (CRB) lampreys (the Pacific lamprey, Lampetra tridentata, and the western brook lamprey, L. richardsoni). We evaluated the usefulness of current diagnostic characteristics for identification of larval lampreys (i.e., pigment patterns) and collected material for development of meristic and morphometric descriptions of early life stage CRB lampreys, and we determined the effects of temperature on survival and development of early life stage CRB lampreys. Thirty-one larval lampreys were collected from locations throughout the CRB and transported to the Columbia River Research Laboratory. Lampreys were sampled at six-week intervals at which time they were identified to the species level based on current diagnostic characteristics. Sampling was repeated until lampreys metamorphosed, at which time species identification was validated based on dentition, or until they died, at which time they were preserved for genetic examination. These lampreys were sampled 30 times with two individuals metamorphosing, both of which were consistently identified, and subsequently validated, as Pacific lampreys. Of the remaining lampreys, only one was inconsistently identified (Pacific lamprey in 83% of the sampling events and western brook lamprey in 17% of the sampling events). These data suggest that pigmentation patterns do not change appreciably through time. In 2001 and 2002 we artificially spawned Pacific and western brook lampreys in the laboratory to provide material for meristic and morphometric descriptions. We collected, digitized, preserved, and measured the mean chorion diameter of Pacific and western brook lamprey embryos. Embryos ranged in development from 1 d post fertilization to just prior to hatch, and were incubated at 14 C. Mean chorion diameter was greater and more variable for Pacific lampreys (mean {+-} SD; 1.468 {+-} 0.107 mm, N = 320) than for western ...
Date: January 1, 2004
Creator: Meeuwig, Michael
Partner: UNT Libraries Government Documents Department

BIO-ORGANIC CHEMISTRY QUARTERLY REPORT. December 1962 throughFebruary 1963

Description: This report covers the following titles: (1) A versatile solvent to replace phenol for the paper chromatography of radioactive intermediary metabolites; (2) Chromatography of plant lipids on alumina paper; (3) Quinone and pigment composition of chloroplasts and quantasomes from Spinacea oleracea; (4) The lipid composition of chloroplast lamellae from Spinacea oleracea; (5) Metal chelates and photochemistry of flavins; (6) Photoinduced ESR in some solutions of organic electron donors and acceptors; (7) Fluorescence of oriented dye-macromolecule complexes--Theoretical study; (8) Formation of adenine by electron irradiation of methane, ammonia, and water; (9) Uptake of organic compounds by planarians; (10) The planaria: Absorption spectrum, cell disaggregation, and studies on homogenates.
Date: March 29, 1963
Partner: UNT Libraries Government Documents Department

Thenature of marbled Terra Sigillata slips: a combined mu XRF and mu XRD investigation

Description: In addition to the red terra sigillata production, the largest Gallic workshop (La Graufesenque) made a special type of terra sigillata, called 'marbled' by the archaeologists. Produced exclusively on this site, this pottery is characterized by a surface finish made of a mixture of yellow and red slips. Because the two slips are intimately mixed, it is difficult to obtain the precise composition of one of the two constituents without contamination by the other. In order to obtain very precise correlation at the appropriate scale between the color aspect and the element and mineralogical phase distributions in the slip, combined electron microprobe, x-ray micro spectroscopies and micro diffraction on cross sectional samples were performed. The aim is to discover how potters were able to produce this unique type of terra sigillata and especially this slip showing an intense yellow color. Results show that the yellow component of marbled sigillata was made from a titanium-rich clay preparation. The color is related to the formation of a pseudobrookite (TiFe2O5) phase in the yellow part of the slip, the main characteristics of that structure being considered nowadays as essential for the fabrication of stable yellow ceramic pigments. Its physical properties such as high refractive indices and a melting point higher than that of most silicates widely used as ceramic colorants are indeed determinant for this kind of applications. Finally, the red parts have a similar composition (elementary and mineralogical) to the one of standard red slip.
Date: January 31, 2009
Creator: Leon, Yoanna; Sciau, Philippe; Goudeau, Philippe; Tamura, Nobumichi; Webb, Sam & Mehta, Apurva
Partner: UNT Libraries Government Documents Department

PS2004 Light-harvesting Systems Workshop

Description: This special issue of the international scientific research journal Photosynthesis Research consists of 25 original peer-reviewed contributions from participants in the PS 2004 Lisht-Harvesting Systems Workshop. This workshop was held from 26-29, 2004 at Hotel Le Chantecler, Sainte-Adele, Quebec, Canada. The workshop was a satellite meeting of the XIII International Congress on Photosynthesis held August 29-September 3, 2004 in Montreal, Canada. The workshope dealt with all types of photosynthetic antenna systems and types of organisms, including anoxygenic photosynthetic bacteria, cyanobacteria, algae and higher plants, as well as in vitro studies of isolated pigments. This collection of papers is a good representation of the highly interdisciplinary nature of modern research on photosynthetic antenna complexes, utilizing techniques of advanced spectroscopy, biochemistry, molecular biology, synthetic chemistry and structural determination to understand these diverse and elegant molecular complexes.
Date: November 1, 2005
Creator: Blankenship, Robert E.
Partner: UNT Libraries Government Documents Department

Underwater Coatings for Contamination Control

Description: The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included 1) Test Area North (TAN-607) with epoxy painted concrete walls; 2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; 3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and 4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55oF to 80oF dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: · Be easy to apply · Adhere well to the four surfaces of interest · Not change or have a negative impact on water chemistry or clarity · Not be hazardous in final applied form · Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the ...
Date: February 1, 2004
Creator: Tripp, Julia L.; Archibald, Kip; Phillips, Ann-Marie & Campbell, Joseph
Partner: UNT Libraries Government Documents Department

Smart Surfaces: New Coatings & Paints with Radiation Detection Functionality

Description: Paints are being developed and tested that might ultimately be able to detect radiological agents in the environment by incorporating special pigments into an organic polymeric binder that can be applied as a paint or coatings. These paints detect radioactive sources and contaminants with inorganic or organic scintillation or thermo-luminescent pigments, which are selected based upon the radiation ({alpha}, {beta}, {gamma} or n) to be detected, and are shown in Figure 1.
Date: March 12, 2007
Creator: Farmer, J & Choi, J
Partner: UNT Libraries Government Documents Department

Discovery of Unusual Minerals in Paleolithic Black Pigments from Lascaux (France) and Ekain (Spain)

Description: Analyses of archaeological materials aim to rediscover the know-how of Prehistoric people by determining the nature of the painting matter, its preparation mode, and the geographic origin of its raw materials. This study deals with identification of manganese oxides in black pigments by micro-XANES (X-ray absorption near-edge structure) based on previous TEM (transmission electron microscopy) studies. Complex mixtures of the manganese oxides studied are present in some of mankind's oldest known paintings, namely those from the caves of Lascaux (Dordogne, France) and Ekain (Basque country, Spain). Scarce manganese oxide minerals, including groutite, hausmannite, and manganite, were found for the first time in Paleolithic art at these archaeological sites. Because there are no known deposits of such minerals in these areas, more distant origins and trade routes are inferred. The closest known Mn-rich geological province for Lascaux is the central Pyrenees, which is {approx} 250 km from the Dordogne area.
Date: December 13, 2006
Creator: Chalmin, E.; Farges, F.; Vignaud, C.; Susini, J.; Menu, M. & Brown, G. E., Jr.
Partner: UNT Libraries Government Documents Department

Structural Determinats Underlying Photoprotection in the Photoactive Orange Carotenoid Protein of Cyanobacteria

Description: The photoprotective processes of photosynthetic organisms involve the dissipation of excess absorbed light energy as heat. Photoprotection in cyanobacteria is mechanistically distinct from that in plants; it involves the Orange Carotenoid Protein (OCP), a water-soluble protein containing a single carotenoid. The OCP is a new member of the family of blue light photoactive proteins; blue-green light triggers the OCP-mediated photoprotective response. Here we report structural and functional characterization of the wildtype and two mutant forms of the OCP, from the model organism Synechocystis PCC6803. The structural analysis provides highresolution detail of the carotenoidprotein interactions that underlie the optical properties of the OCP, unique among carotenoid-proteins in binding a single pigment per polypeptide chain. Collectively, these data implicate several key amino acids in the function of the OCP and reveal that the photoconversion and photoprotective responses of the OCP to blue-green light can be decoupled.
Date: April 1, 2010
Creator: Wilson, Adjele; Kinney, James N.; Zwart, Petrus H.; Punginelli, Claire; D'Haene, Sandrine; Perreau, Francois et al.
Partner: UNT Libraries Government Documents Department

TASK 2.5.7 FIELD EXPERIMENTS TO EVALUATE COOL-COLORED ROOFING

Description: Aesthetically pleasing dark roofs can be formulated to reflect like a highly reflective white roof in the near infrared portion of the solar spectrum. New paint pigments increase the near infrared reflectance of exterior finishes by minimizing the absorption of near-infrared radiation (NIR). The boost in the NIR reflectance drops the surface temperatures of roofs and walls, which in turn reduces cooling-energy use and provides savings for the homeowner and relief for the utilities. In moderate and hot climates, a roof surface with high solar reflectance and high thermal emittance was shown by Akbari et al. (2004) and by Parker and Sherwin (1998) to reduce the exterior temperature and produce savings in comfort cooling. The new cool color pigments can potentially reduce emissions of carbon dioxide, which in turn reduces metropolitan heat buildup and urban smog. The pigments can also help conserve water resources otherwise used to clean and process fuel consumed by fossil-fuel driven power plants. Cool roofs also result in a lower ambient temperature that further decreases the need for air conditioning, retards smog formation, and improves thermal comfort. Parker, Sonne and Sherwin (2002) demonstrated that white barrel and white flat tiles reduced cooling energy consumption by 22% of the base load used by an adjacent and identical home having direct nailed dark shingles. Part of the savings was due to the reflectance of the white tiles; however, another part was due to the mass of the tile and to the venting occurring within the double batten installation. With, Cherry and Haig (2009) have studied the influence of the thermal mass and batten space ventilation and have found that, referenced to an asphalt shingle system, it can be equivalent to an additional 28 points of solar reflectivity. The double batten arrangement has wooden counter battens laid vertically (soffit-to-ridge) ...
Date: March 1, 2010
Creator: Miller, William A; Cherry, Nigel J; Allen, Richard Lowell; Childs, Phillip W; Atchley, Jerald Allen; Ronnen, Levinson et al.
Partner: UNT Libraries Government Documents Department