214 Matching Results

Search Results

prev Results: 97 - 120 next
open access

Mitochondrial phenotypes and genotypes in yeast. Technical annual progress report, September 1, 1975--August 31, 1976

Description: An eight component yeast complex III preparation has been obtained which contains up to 6.2 nanomoles of heme b per mg protein. Studies in which the enzyme activity associated with the complex (reduced CoQ-cytochrome c reductase) was monitored, and in which in vivo /sup 14/C-leucine incorporation into whole washed mitochondrial membranes was carried out suggest that (1) entrance of mitochondrially translated proteins into the mitochondrial inner membrane is not dependent upon a prior build up o… more
Date: January 1, 1976
Creator: Rouslin, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Molecular sieving action of the cell membrane during gradual osmotic hemolysis

Description: Rat erythrocytes were hemolyzed by controlled gradual osmotic hemolysis to study cell morphology and hemoglobin loss from individual cells. Results suggest that each increase in the rate of loss of a protein from the cells during the initial phases of controlled gradual osmotic hemolysis is caused by the passage of a previously impermeable species across the stressed membrane. Similarly, during the final stages of controlled gradual osmotic hemolysis, each sharp decrease in the rate of loss of … more
Date: May 1, 1977
Creator: MacGregor, R. D. II
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Biological Processes in the Water Column of the South Atlantic Bight. Progress Report, July 12--August 20, 1976

Description: Preliminary results are reported from a study of the relationship between intrusions of phytoplankton, zooplankton, and particulate matter in the South Atlantic Bight off the coast of Georgia and Northeast Florida. The relationship between temperature, chlorophyll, and particle volume in bottom water from various locations was determined and the data were correlated with data on water mass movements. Samples were collected from a ship following a specified grid pattern.
Date: February 1, 1977
Creator: Paffenhofer, G. A. & Dunstan, W. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Energy transfer mechanisms in photobiological reactions. Progress report, 1 August 1975--30 April 1976

Description: As in our earlier work on the sensitized photooxidation of substituted phenylalanines, ring substituents were found to have a marked effect on the photooxidation of uracil. This compound was selected as a typical pyrimidine for detailed studies of the mechanism of photooxidation of molecules of biological importance. The photooxidation of a series of 5-substituted uracils as sensitized by eosin Y, ruthenium bipyridyl, 3-methyl-lumiflavin and methylene blue was studied using oxygen electrode and… more
Date: April 30, 1976
Creator: Spikes, J. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Peridinin-chlorophyll a proteins of dinoflagellate algae. [Role in photosynthesis]

Description: The pigments which function as the energy collection systems for photosynthesis are either tetrapyrroles or carotenoids. In the oceans, which cover over 70 percent of the surface of the earth, carotenoids may be more important than chlorophylls for photosynthetic energy capture by phytoplankton. A characteristic feature of the principal marine phytoplankton is the possession of a high carotenoid content. In general each major group of phytoplankton has a specific carotenoid which accounts for a… more
Date: January 1, 1976
Creator: Siegelman, H W; Kycia, J H & Haxo, F T
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hydrography of Onslow Bay, North Carolina: September 1975 (OBIS II)

Description: Data collected during studies of Onslow Bay, off the North Carolina coast during cruises during September, 1975, are reported. Current meters and thermography were placed at depths of 10 and 22 m along the 28 m isobath in the northeastern and southwestern sectors of the Bay. Data are included on wind turbulence and velocity; seawater salinity and temperature at various depths; the content of nitrates, phosphates, silicate, oxygen, chlorophyll, and phytoplankton biomass at various depths. Hydrog… more
Date: September 1, 1975
Creator: Atkinson, L. P.; Singer, J. J.; Dunstan, W. M. & Pietrafesa, L. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nutrient enrichment and eutrophication of Lake Michigan. Progress report, November 1, 1971--September 30, 1977

Description: Data on mixing processes in the nearshore zone of Lake Michigan are presented. Emphasis was placed on an area near Holland, Michigan where typical summer mixing patterns of the Kalamazoo River plume between the nearshore zone and mid-lake water mass were studied. Results showed that the nutrient load of the river's tributaries studied had a marked effect on the nearshore zone and the standing crop and species composition of phytoplankton. Data are included on the content of phosphates, silica, … more
Date: January 1, 1977
Creator: Schelske, C. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

Description: Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight bch'' genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. … more
Date: August 1, 1992
Creator: Burke-Agueero, D. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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 biochemica… more
Date: June 17, 2011
Creator: Niyogi, Prof. Krishna
Item Type: Refine your search to only Text
Partner: UNT Libraries Government Documents Department
open access

New methods and instrumentation for the characterization of biopolymers using electrospray ionization-mass spectrometry

Description: The technique of electrospray ionization (ESI) has significantly extended the ability to characterize large molecules by mass spectrometry. Proteins to at least 200,000 D can be transferred intact to the gas phase and molecular weights determined with precisions as high as 0.001% if individual charge states can be resolved. The ESI-MS can also serve as a near ideal interface and detector for capillary column separations providing a basis for highly efficient sample utilization. Using capillary … more
Date: September 1, 1992
Creator: Smith, R. D.; Udseth, H. R.; Rockwood, A. L.; Winger, B. E.; Hofstadler, S. A.; Goodlett, D. R. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Capillary electrophoresis - electrospray ionization mass spectrometry in small diameter capillaries

Description: Methods (such as small inner diameter capillaries) are being explored to increase analyte sensitivity in capillary electrophoresis- electrospray ionization/mass spectroscopy(CE-ESI/MS). Results are reported for melittin in a protein mixture, with 10 to 100 {mu}m ID capillaries; and for a mixture of aprotinin, cytochrome c, myoglobin, and carbonic anhydrase, with 5 to 50 {mu}m ID capillaries. It is shown that an increase in solute sensitivity occurs when small ID capillaries ({lt} 20 {mu}m) are … more
Date: June 1, 1992
Creator: Wahl, J. H.; Goodlett, D. R.; Udseth, H. R. & Smith, R. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Threshold switching in the amorphous semiconductor As/sub 15/Te/sub 70/Ge/sub 15/ and in the organic semiconductor melanin

Description: The threshold switching properties of the amorphous semiconductor As/sub 15/Te/sub 70/Ge/sub 15/ and the organic semiconductor melanin have been examined with threshold switching experiments. Measurements of delay time, energy and average resistance as functions of applied voltage were made by a computer controlled data acquisition system. These measurements were made on As/sub 15/Te/sub 70/Ge/sub 15/ at 243, 273 and 298/sup 0/K. A time dependent electrothermal model was solved numerically. The… more
Date: June 1, 1976
Creator: Culp, C. H. III
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of Light on Respiration and Development of Photosynthetic Cells. Progress Report, September 1, 1975--June 1, 1976

Description: Adaptation and deadaptation of unicellular algal cells to a hydrogen metabolism may involve not only hydrogenase but also the site of entry of electrons from NADH. NADPH can also serve as an electron donor in a chloroplast preparation fortified with hydrogenase but the rate of photoevolution falls off rapidly perhaps due to competition with NADP for electrons. The evolution of H/sub 2/ with reduced pyridine nucleotide as electron donor is coupled to ATP formation. Evidence is presented that sol… more
Date: June 1, 1976
Creator: Gibbs, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Paleolimnological sedimentation of organic carbon, nitrogen, phosphorus, fossil pigments, pollen, and diatoms in a hypereutrophic, hardwater lake: a case history of eutrophication

Description: The sediment history of this productive, hardwater lake (Wintergreen Lake in southern Michigan) developed as five periods of increasing eutrophy, each strongly influenced by a hybrid basin morphometry. This morphometry led to higher productivity per unit area by macrophytic plants in littoral waters of the lake than by phytoplankton in pelagic waters. Climate and trophic conditions during each of the five periods between 14,000 and 0 B.P. are postulated.
Date: January 1, 1977
Creator: Manny, B. A.; Wetzel, R. G. & Bailey, R. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Radiationless Energy Conversion of Photoexcited Triplet State of Organic Molecules. Progress Report for May 1, 1975--April 30, 1977

Description: During the initial two years of our ERDA-supported research program we have attempted to define and understand the mechanisms active in the intersystem crossing processes of large polycyclic hydrocarbons and chlorophyll. To study these excited states energy conversion processes we have utilized optical detection of magnetic resonance spectroscopy, as developed in our laboratory, which is uniquely applicable to these molecular systems. Our results on polycyclic hydrocarbons have shown that an un… more
Date: January 1, 1977
Creator: Clarke, R. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fast repetition rate (FRR) fluorometer for making in situ measurements of primary productivity

Description: Understanding the ocean carbon cycle and predicting how climate-induced changes in ocean circulation will affect ocean productivity requires that (a) primary productivity be measured with high spatial and temporal resolution, and (b) natural variability in primary productivity be parameterized with regardto environmental factors such as nutrient availabuity, irradiance, and temperature. Instrumentation to measure primary productivity from the stimulated in vivo fluoresence of phytoplankton chlo… more
Date: January 1, 1992
Creator: Kolber, Z. S. & Falkowski, P. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Continental Shelf Processes Effecting the Oceanography of the South Atlantic Bight. Hydrography of Onslow Bay, North Carolina: September 1975 (OBIS II). Progress Report

Description: Over the course of OBIS II, 3-14 September, two intrusion cores were observed. One was apparently trapped nearshore over much of the study period, but as time went on, it either dissipated, moved too far shoreward or moved too far laterally along the shelf to be detected by the existing observational grid. The other (later) intrusion was first detected on 5-7 September and was observed to be moving into the Bay from the southeast over the remainder of the study period. Plots of the horizontal t… more
Date: March 12, 1976
Creator: Atkinson, L. P.; Singer, J. J.; Dunstan, W. M. & Pietrafesa, L. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nitrogen control of chloroplast differentiation. Annual progress report

Description: This project is directed toward understanding how the availability of nitrogen affects the accumulation of chloroplast pigments and proteins functioning in energy transduction and carbon metabolism. Molecular analyses performed with Chlamydomonas reinhardtii grown in a continuous culture system such that ammonium concentration is maintained at a low steady-state concentration so as to limit cell division. As compared to chloroplasts from cells of non-limiting nitrogen provisions, chloroplasts o… more
Date: July 1, 1992
Creator: Schmidt, G. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Organization of the R chromosome region in maize. Triennial report

Description: R-r controls the production of anthocyanin pigment in plant parts and the aleurone layer of seeds through the production of a family of transcriptional activating proteins of the helix-loop-helix type. A series of mutant derivatives of R-r which have lost portions of the complex through unequal crossing over or intrachromosomal rearrangements have been examined to elucidate the molecular structure of the complex. The complex comprises a series of repeated, homologous components arranged in both… more
Date: July 1, 1992
Creator: Kermicle, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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 s… more
Date: January 1, 2004
Creator: Meeuwig, Michael
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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 c… more
Date: January 31, 2009
Creator: Leon, Yoanna; Sciau, Philippe; Goudeau, Philippe; Tamura, Nobumichi; Webb, Sam & Mehta, Apurva
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Regeneration of nitrogen by zooplankton and fish in the Northwest Africa and Peru upwelling ecosystems

Description: The availability of nutrients and light are the dominant controlling factors of the levels of primary production in the ocean. In the lower latitudes where most coastal upwelling areas are located, the amount of light is seldom below the critical level to inhibit productivity so nutrients are often the limiting factor in phytoplankton growth. Nutrients utilized in primary productivity are derived from two sources in upwelling areas. Nutrients are introduced to the euphotic zone from depth by th… more
Date: January 1, 1976
Creator: Whitledge, T E
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nutrient enrichment and eutrophication of Lake Michigan. Progress report, July 1, 1975--June 30, 1976

Description: Studies were conducted on relationships between phytoplankton and major nutrients. Data were collected on species composition and abundance of phytoplankton and on chlorophyll a, primary productivity, phosphorus silica, nitrate, ammonia, pH, chloride, specific conductance, water temperature, and transparency. Open lake studies confirmed a predicted shift in species composition from diatoms to blue-green algae in the epilimnetic waters and offered evidence that silica limitation is the major fac… more
Date: January 1, 1976
Creator: Schelske, C. L. & Davis, C. O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen