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The Metabolism of 2-Caroboxy-4-Ketopentitol Diphosphate

Description: 2-Carboxy-4-ketopentitol is converted enzymatically by a cell-free preparation from spinach leaves into a substance undergoing acid-lactone interconversion. This substance has no phosphate or letone group and is probably a dicarboxylic, six-carbon sugar acid or the saccharic or saccharinic acid type. The significance of these findings with regard to the metabolic role of 2-carboxy-4-ketopentitol diphosphate is discussed.
Date: July 15, 1958
Creator: Moses, V. & Calvin, M.
Partner: UNT Libraries Government Documents Department

The Path of Carbon in Photosynthesis IV. The Identity and Sequencefo the Intermediates in Sucrose Synthesis

Description: The synthesis of sucrose from C{sup 14}0{sub 22} by green algae has been investigated and the intermediates separated by the method of paper chromatography. It is shown that sucrose is the first free sugar appearing during photosynthesis. It is apparently formed by condensation of the glucose-I-phosphate and a fructose phosphate. A series of radioautographs of paper chromatograms of extracts from plants which have photosynthesized for different periods of time has been prepared. The results indicate that 2-phosphoglyceric acid is the first product synthesized from C0{sub 2} during photosynthesis.
Date: December 14, 1948
Creator: Calvin, M. & Benson, A.
Partner: UNT Libraries Government Documents Department

FLASHFOAM : a triboluminescent polymer foam for mechanical sensing.

Description: The formulation and processing of a brittle polyurethane foam containing triboluminescent powder additives is described. Two powder additives, known to exhibit triboluminescence, were individually examined: triethylammonium tetrakis (dibenzoylmethanato) europate [NEt3H][Eu(DBM)4] and ordinary table sugar (sucrose, C12H22O11). In each instance, the powders were mixed into the polyol component of the foam. When combined with the isocyanate component, the resulting foams had these powders incorporated into their cellular structure so as to induce a triboluminescent response upon crushing during impact testing. The triboluminescent response of foam specimens containing each of these powder additives was characterized by measuring: the time rate of change in the optical output (measured as Watts), the peak optical output, the total integrated output (Watt-seconds), during the impact event. Foams containing the europate compound were found to yield several orders of magnitude higher output when compared to the sugar-containing foam. Strain rate and concentration of the powder (in the foam) were important variables with respect to optical output. Both the peak and total triboluminescent output increased with increasing powder concentration. Peak output was also found to increase with increasing strain rate. However, the total output was found to be roughly constant for a given concentration regardless of strain rate (over the strain rate range: 20 sec-1< e& < 150 sec-1). At very low strain rates, no triboluminescent response was measured.
Date: July 1, 2003
Creator: Dentinger, Paul M.; Whinnery, LeRoy L., Jr. & Goods, Steven Howard
Partner: UNT Libraries Government Documents Department

Anisotropy studies around the Galactic Centre at EeV energies with the Auger Observatory

Description: Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius A. Also the events detected simultaneously by the surface and fluorescence detectors (the ''hybrid'' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.
Date: July 1, 2006
Creator: Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allison, P.; Alvarez, C. et al.
Partner: UNT Libraries Government Documents Department

Anisotropy studies around the Galactic Center at EeV energies with Auger data

Description: The Pierre Auger Observatory data have been analyzed to search for excesses of events near the direction of the galactic center in several energy ranges around EeV energies. In this region the statistics accumulated by the Observatory are already larger than that of any previous experiment. Using both the data sets from the surface detector and our hybrid data sets (events detected simultaneously by the surface detector and the fluorescence detector) we do not find any significant excess. At our present level of understanding of the performance and properties of our detector, our results do not support the excesses reported by AGASA and SUGAR experiments. We set an upper bound on the flux of cosmic rays arriving within a few degrees from the galactic center in the energy range from 0.8-3.2 EeV. We also have searched for correlations of cosmic ray arrival directions with the galactic plane and with the super-galactic plane at energies in the range 1-5 EeV and above 5 EeV and have found no significant excess.
Date: July 1, 2005
Creator: Letessier-Selvon, Antoine & /Paris U., VI-VII
Partner: UNT Libraries Government Documents Department

Measuring the stress-bridging law of a heterogeneous material

Description: In this investigation, fracture experiments on a high explosive material (PBX 9501) were conducted using the digital image correlation technique. From the experimental measurement, we are able to determine quantitatively the stress-bridging law (or decohesion law), which characterizes the relationship between the bridging stress and the opening displacement cross the bridging zone. The plastic bonded HMX (PBX) high explosives are composed of the energetic crystal (HMX) and a polymeric binder. Previous experimental observations showed that the fracture process in the sugar mock, a simulant of the PBX 9501 high explosive, is very different from that in brittle solids, even though the high explosive material PBX 9501 is quite brittle under tension. A close examination of the fracture surface revealed that before crack initiation and propagation, a very large damage region is developed ahead of the crack tip. Since such a damage region is very narrow, it can be modeled as a stress bridging zone. Due to the presence of the sizable bridging zone, conventional fracture mechanics is no longer applicable. Stress bridging has to be considered explicitly in order to understand of fracture processes in the PBX 9501 high explosive and the sugar mock. The model, which explicitly incorporates stress-bridging mechanism, is shown in Fig.1. In describing the model, one would need the following quantities, bridging zone length R, bridging stress {sigma}(x{sub 1}), bridging-zone opening displacement {sigma}(x{sub 1}), and the critical stress, {sigma}{sub C}, at which bridging zone starts to develop. Among these quantities, the key element for the bridging model is the relationship between the bridging stress {sigma} and the opening displacement cross the bridging zone {sigma}, i.e., {sigma}({delta}), or the stress-bridging law that can only be determined through experimental measurement. In this study, fracture experiments on PBX 9501 high explosive using the digital image correlation technique were conducted. ...
Date: January 1, 2002
Creator: Liu, C. (Cheng)
Partner: UNT Libraries Government Documents Department

Sugar Transport and Metabolism in Thermotoga

Description: The work conducted under this grant demonstrated that the hyperthermophilic bacterium Thermotoga neapolitana carries out glucose and lactose transport in a sodium-dependent manner and that energization of anaerobic cells is required to observe transport. We also demonstrated that Thermotoga maritima carries out maltose and glucose transport using periplasmic sugar binding proteins. We began defining patterns of expression of genes encoding sugar transport and catabolic functions in both T. maritima and T. neapolitana. We began a collaborative effort to identify all the genes regulated at the transcriptional level in response to sugars substrates. These funds also allowed us to begin an examination of the functions of several periplasmic substrate binding proteins encoded in the genome of T. maritima.
Date: February 11, 2003
Creator: Noll, Kenneth M. & Romano, Antonio H.
Partner: UNT Libraries Government Documents Department

Victorias energy efficiency and cogeneration project. Final report

Description: This report describes a two-phase energy project currently contemplated for joint implementation at the Victorias Milling Company, a large sugar mill and refinery on the island of Negros in the Visayas region of the Philippines. The Energy Efficiency (EE) phase is expected to reduce of eliminate VMC`s fossil fuel consumption, which will have a direct and substantial impact on carbon emissions. Phase I is an EE project which involves the installation of equipment to reduce steam and electricity demand in the factories. Phase II, will involve retrofitting and increasing the capacity of the steam and power generation systems, and selling power to the grid. By increasing efficiency and output, the cogeneration project will allow the factory to use only bagasse sugar cane fiber waste as fuel for energy needs. The cogeneration project will also eliminate VMC`s electricity purchases and supply additional power for the island, which will offset generation capacity expansion on the island and the Visayas region.
Date: October 31, 1998
Partner: UNT Libraries Government Documents Department

Running Head: Control and Adjustment of the Rate of Photosynthesis Above Present CO{sub 2} Levels

Description: The adjustment of photosynthesis to different environmental conditions and especially to elevated CO{sub 2} is often characterized in terms of changes in the processes that establish (limit) the net CO{sub 2} assimilation rate. At slightly above present ambient pCO{sub 2} light-saturated photosynthetic responses to CO{sub 2} depart limitation by the catalytic capacity of tissue rubisco content. An hypothesis attributing this departure to limited thylakoid reaction/electron transport capacity is widely accepted, although we find no experimental evidence in the literature supporting this proposition.. The results of several tests point to the conclusion that the capacity of the thyiakoid reactions cannot be generally responsible for the deviation from rubisco limitation. This conclusion leaves a significant gap in the interpretation of gas exchange responses to CO{sub 2}. Since the inputs to the photosynthetic carbon reduction cycle (CO{sub 2} and photon-capture/electron-transport products) do not limit photosynthesis on the shoulder of the A=f(c{sub i}) curve, the control of photosynthesis can be characterized as: due to feedback. Several characteristics of gas exchange and fluorescence that occur when steady-states in this region are perturbed by changes in CO{sub 2} or O{sub 2} suggest significant regulation by conditions other than directly by substrate RuBP levels. A strong candidate to explain these responses is the triose-phosphate flux/ inorganic phosphate regulatory sequence, although not all of the gas exchange characteristics expected with ''TPU-limitation'' are present (e.g. oxygen-insensitive photosynthesis). Interest in nitrogen allocation between rubisco and light capture/electron transport as the basis for photosynthetic adjustment to elevated CO{sub 2} may need to be reconsidered as a result of these findings. Contributors to the feedback regulation of photosynthesis (which may include sucrose phosphate synthase and fructose bisphosphatase activities, phloem loading, and ''sink-strength'') may play a large role in the adjustment of photosynthesis to elevated CO{sub 2}. The continuing rise in atmospheric CO{sub ...
Date: December 1, 1996
Creator: Ball, J. Timothy
Partner: UNT Libraries Government Documents Department

THE CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

Description: The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates were completed and issued. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter of 2000. Initial pilot facility shakedown was completed during the fourth quarter. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. During this first quarter of 2001, shredding of the feed material and final feed conditioning were completed. Pilot facility hydrolysis production was completed to produce lignin for co-fire testing. During this quarter, TVA completed the washing and dewatering of the lignin material produced from the MSW hydrolysis. Seven drums of lignin material were washed to recover the acid and sugar from the lignin and provide an improved fuel for steam generation. Samples of both the lignin and bio-solids fuel materials for co-fire testing were sent to the co-fire facility (EERC) for evaluation. After sample evaluation, EERC approved sending the material and all of the necessary fuel for testing was shipped to EERC. EERC has requested and will receive coal typical of the fuel to the TVA-Colbert boilers. This material will be used at EERC as baseline material and for mixing with the bio-fuel for combustion testing. EERC combustion testing of the bio based fuels is scheduled to begin in August of 2001. The TVA-Colbert facility has neared completion of the task to evaluate the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing ...
Date: July 1, 2001
Creator: Berglund, Ted; Ranney, Jeffrey T.; Babb, Carol L. & Broder, Jacqueline G.
Partner: UNT Libraries Government Documents Department

Double-Diffusive Finger Convection: Flow Field Evolution in a Hele-Shaw Cell

Description: Double-diffusive finger convection is a hydrodynamic instability that can occur when two components with different diffusivities are oppositely stratified with respect to the fluid density gradient as a critical condition is exceeded. Laboratory experiments were designed using sodium chloride and sucrose solutions in a Hele-Shaw cell. A high resolution, full field, light transmission technique was used to study the development of the instability. The initial buoyancy ratio (R{sub p}), which is a ratio of fluid density contributions by the two solutes, was varied systematically in the experiments so that the range of parameter space spanned conditions that were nearly stable (R{sub p} = 2.8) to those that were moderately unstable (R{sub p} = 1.4). In systems of low R{sub p}, fingers develop within several minutes, merge with adjacent fingers, form conduits, and stall before newer-generated fingers travel through the conduits and continue the process. Solute fluxes in low R{sub p} systems quickly reach steady state and are on the order of 10{sup {minus}6} m{sup 2} sec{sup {minus}1}. In the higher R{sub p} experiments, fingers are slower to evolve and do not interact as dynamically as in the lower R{sub p} systems. Our experiment with initial R{sub p} = 2.8 exhibited flux on the order of that expected for a similar diffusive system (i.e., 10{sup {minus}7} m{sup 2} sec{sup {minus}1}), although the structures were very different than the pattern of transport expected in a diffusing system. Mass flux decayed as t{sup 1/2} in two experiments each with initial R{sub p} = 2.4 and 2.8.
Date: December 21, 2000
Creator: Cooper, Clay A.; Glass, Robert J., Jr. & Tyler, Scott W.
Partner: UNT Libraries Government Documents Department

Full - sky search for ultrahigh - energy cosmic ray anisotropies

Description: Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for anisotropy patterns in the arrival directions of cosmic rays with energies > 10{sup 19.6} eV. We determine the angular power spectrum from an expansion in spherical harmonics for modes out to {ell} = 5. Based on available statistics, we find no significant deviation from isotropy. We compare the rather modest results which can be extracted from existing data samples with the results that should be forthcoming as new full-sky observatories begin operation.
Date: July 2, 2003
Creator: al., Luis A. Anchordoqui et
Partner: UNT Libraries Government Documents Department

Final Report

Description: This report describes basic science studies of conversion of starch to sucrose in plant leaves. The importance of maltose is described. The studies proved that hydrolysis of the starch is more important than phosphorolysis.
Date: February 7, 2005
Creator: Sharkey, Thomas D.
Partner: UNT Libraries Government Documents Department

Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. A new mechanism for the regulation of stomatal-aperture size in intact leaves: Accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba L.

Description: At various times after pulse labeling Vicia faba L. leaflets with {sup 14}CO{sub 2}, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents whereas those from rinsed peels contained only cytoplastic contents. Sucrose specific radioactivity peaked in palisade cells, 111 GBq{center_dot}mol{sup {minus}1}, at 20 min. In contrast, the {sup 14}C content and sucrose specific radioactivity were very low in guard cells for 20 min, implying little CO{sub 2} incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum sucrose specific radioactivity and a high sucrose influx rate. These and other comparisons implied the presence of (a) multiple sucrose pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived sucrose in guard-cell walls sufficient to diminish stomatal opening by {approximately} 4 {micro}m. Factors expected to enhance sucrose accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic sucrose concentration, which is elevated when mesophyll-sucrose efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal-aperture size by this previously unrecognized mechanism.
Date: December 31, 1996
Creator: Lu, P.; Outlaw, W. H., Jr.; Smith, B. G. & Freed, G. A.
Partner: UNT Libraries Government Documents Department

THE PATH OF CARBON IN PHOTOSYNTHESIS

Description: Biosynthesis begins with photosynthesis. Green plants and other photosynthetic organisms use the energy of absorbed visible light to make organic compounds from inorganic compounds. These organic compounds are the starting point for all other biosynthetic pathways. The products of photosynthesis provide not only the substrate material but also chemical energy for all subsequent biosynthesis. For example, nonphotosynthetic organisms making fats from sugars would first break down the sugars to smaller organic molecules. Some of the smaller molecules might be oxidized with O{sub 2} to CO{sub 2} and water. These reactions are accompanied by a release of chemical energy because O{sub 2} and sugar have a high chemical potential energy towards conversion to CO{sub 2} and H{sub 2}O. In a biochemical system only part of this energy would be released as heat. The heat would be used to bring about the conversion of certain enzymic cofactors to their more energetic forms. These cofactors would then enter into specific enzymic reactions in such a way as to supply energy to drive reactions in the direction of fat synthesis. Fats would be formed from the small organic molecules resulting from the breakdown of sugars. Thus sugar, a photosynthetic product, can supply both the energy and the material for the biosynthesis of fats.
Date: October 1, 1960
Creator: Bassham, J.A. & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

JGI Fungal Genomics Program

Description: Genomes of energy and environment fungi are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 50 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such 'parts' suggested by comparative genomics and functional analysis in these areas are presented here
Date: March 14, 2011
Creator: Grigoriev, Igor V.
Partner: UNT Libraries Government Documents Department

Porous HMX initiation studies -- Sugar as an inert simulant

Description: For several years the authors have been using magnetic particle velocity gauges to study the shock loading of porous HMX (65 and 73% TMD) of different particle sizes to determine their compaction and initiation characteristics. Because it has been difficult to separate the effects of compaction and reaction, an inert simulant was needed with properties similar to HMX. Sugar was selected as the simulant for several reasons: (1) the particle size distribution of C and H granulated sugar is similar to the coarse HMX the authors have been using (120 {micro}m average size), (2) the particle size of C and H confectioners (powdered) sugar is similar to the fine HMX in the studies (10 {micro}m average size), (3) it is an organic material, and (4) sugar was readily available. Because the densities of HMX and sugar are somewhat different, the authors chose to do the experiments on sugar compacts at 65 and 73% TMD. As expected, no reaction was observed in the sugar experiments. Compaction wave profiles were similar to those measured earlier for the HMX, i.e., the compaction waves in the coarse sugar were quite disperse while those in the fine sugar were much sharper. This indicates that the compaction wave profiles are controlled by particle size and not reaction. Also, the coarse sugar gauge signals exhibited a great deal of noise, thought to the be result of fracto-emission.
Date: November 1, 1997
Creator: Sheffield, S.A.; Gustavsen, R.L. & Alcon, R.R.
Partner: UNT Libraries Government Documents Department

Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species

Description: Photoassimilates are used by plants for production of energy, as carbon skeletons and in transport of fixed carbon between different plant organs. Many studies have been devoted to characterizing the factors that. regulate photoassimilate concentrations in different plant species. Most studies examining photoassimilate concentrations in C{sub 3} plants have focused on analyzing starch and soluble sugars. However, work presented here demonstrates that a number of C{sub 3} plants, including the popular model organism Arabidopsis thaliana (L.) Heynh., and agriculturally important plants, such as soybean [Glycine ma (L.) Merr.], contain significant quantities of furnaric acid. In fact, furnaric acid can accumulate to levels of several mg per g fresh weight in A-abidopsis leaves, often exceeding starch and soluble sugar levels. Furnaric acid is a component of the tricarboxylic acid cycle and, like starch and soluble sugars, can be metabolized to yield energy and carbon skeletons for production of other compounds. Fumaric acid concentrations increase with plant age and light intensity in Arabidopsis leaves. Arabidopsis phloem exudates contain significant quantities of fumaric acid, raising the possibility that fumaric acid may function in carbon transport.
Date: October 1, 2000
Creator: Chia, D.W.; Yoder, T.J.; Reiter, W.D. & Gibson, S.I.
Partner: UNT Libraries Government Documents Department

Sensory Transduction of the CO2 Response of Guard Cells

Description: Stomata have a key role in the regulation of gas exchange and intercellular CO2 concentrations of leaves. Guard cells sense internal and external signals in the leaf environment and transduce these signals into osmoregulatory processes that control stomatal apertures. This research proposal addresses the characterization of the sensory transduction of the CO2 signal in guard cells. Recent studies have shown that in Vicia leaves kept at constant light and temperature in a growth chamber, changes in ambient CO2 concentrations cause large changes in guard cell zeaxanthin that are linear with CO2-dependent changes in stomatal apertures. Research proposed here will test the hypothesis that zeaxanthin function as a transducer of CO2 signals in guard cells. Three central aspects of this hypothesis will be investigated: CO2 sensing by the carboxylation reaction of Rubisco in the guard cell chloroplast, which would modulate zeaxanthin concentrations via changes in lumen pH; transduction of the CO2 signal by zeaxanthin via a transducing cascade that controls guard cell osmoregulation; and blue light dependence of the CO2 signal transduction by zeaxanthin, required for the formation of an isomeric form of zeaxanthin that is physiologically active as a transducer. The role of Rubisco in CO2 sensing will be investigated in experiments characterizing the stomatal response to CO2 in the Arabidopsis mutants R100 and rca-, which have reduced rates of Rubisco-dependent carboxylation. The role of zeaxanthin as a CO2 transducer will be studied in npq1, a zeaxanthin-less mutant. The blue light-dependence of CO2 sensing will be studied in experiments characterizing the stomatal response to CO2 under red light. Arabidopsis mutants will also be used in further studies of an acclimation of the stomatal response to CO2, and a possible role of the xanthophyll cycle of the guard cell chloroplast in acclimations of the stomatal response to CO2. Studies on the ...
Date: June 30, 2003
Creator: Zeiger, Dr. Eduardo
Partner: UNT Libraries Government Documents Department

Sugar as food.

Description: Discusses the sources of sugar, its uses, and its chemical composition.
Date: December 21, 1906
Creator: United States. Dept. of Agriculture.
Partner: UNT Libraries Government Documents Department