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Sample records for bisphosphate carboxylase small

  1. Soybean ribulose bisphosphate carboxylase small subunit: Mechanisms and determinants of RNA turnover. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, R.B. [Georgia Univ., Athens, GA (United States). Dept. of Genetics

    1993-12-31

    An in vitro degradation system has been developed from petunia and soybean polysomes in order to investigate the mechanisms and determinants controlling RNA turnover in higher plants. This system faithfully degrades soybean ribulose-1,5-bisphosphate carboxylase small subunit (rbcS) mRNA into the same products observed in total RNA preparations. In previous years it was shown that the most stable products represent a nested constellation of fragments, which are shortened from their 3{prime} ends, and have intact 5{prime} ends. Exogenous rbcS RNA tagged with novel 5{prime} sequence 15 or 56 bp long were synthesized in vitro as Sp6 and T7 runoff transcripts, respectively. When added to the system they were degraded faithfully into constellation of products which were 15 or 56 bp longer than the endogenous products, respectively. Detailed kinetics on the appearance of these exogenous products confirmed degradation proceeds in an overall 3{prime} to 5{prime} direction but suggested that there are multiple pathways through which the RNA may be degraded. To further demonstrate a precursor product relationships, in vitro synthesized transcripts truncated at their 3{prime} ends were shown to degrade into the expected smaller fragments previously mapped in the 5{prime} portion of the rbcS RNA.

  2. A Novel Approach to Functional Analysis of the Ribulose Bisphosphate Carboxylase Small Subunit Gene by Agrobacterium-Mediated Gene Silencing

    Institute of Scientific and Technical Information of China (English)

    Xiao-Fu Zhou; Peng-Da Ma; Ren-Hou Wang; Bo Liu; Xing-Zhi Wang

    2006-01-01

    A novel approach to virus-induced post-transcriptional gene silencing for studying the function of the ribulose bisphosphate carboxylase small subunlt (rbcS) gene was established and optimized using potato virus X vector and Nicotiana benthamiana as experimental material. The analysis of silencing phenomena,transcriptional level, protein expression, and pigment measurement showed that the expression of the rbcS endogenous gene was inactivated by the expression of a 500-bp homologous cDNA fragment carried in the virus vector.

  3. Differential transcription and message stability of two genes encoding soybean ribulose 1,5-bisphosphate carboxylase small subunit

    International Nuclear Information System (INIS)

    The expression of two closely related soybean ribulose bisphosphate carboxylase small subunit (Rubisco ss) genes, SRS1 and SRS4, has been compared. These genes account for approximately 2-4% of the total transcription in light grown leaves, SRS4 being twice as transcriptionally active as SRS1. The transcription of these genes is reduced more than 30 fold after a pulse of far-red light or extended periods of darkness. When etiolated seedlings are shifted to the light the transcription of both genes increases 30-50 fold. Despite this 30-fold range in transcriptional expression the steady state mRNA levels in light and dark grown tissue differ by less than 8 fold. This suggests that the mRNAs are less stable in light grown tissue. 38 refs., 5 figs

  4. Transcritption regulation of soybean ribulose-1,5-bisphos-phate carboxylase small sub-unit gene by external factors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ribulose-1,5-bisphosphate carboxylase small subunit gene (rbcS) is present with multi-gene family in plant genome. In Glycine max, the rbcS polypeptide (EC4.1.1.39) is encoded by a gene family containing 4-8 members. Three full-length rbcS cDNA clones were isolated and characterized from soybean seedlings, and both of their nucleotide and amino acid sequences showed high similarity. Differential accumulation of the rbcS mRNA was observed among roots, hypocotyls, cotyledons, epicotyls and leaves. The rbcS genes were up-regulated by various external factors such as salicylic acid (SA), salt stress and drought stress. The expression level of rbcS genes after being treated by 2.0 mmol/L SA and 0.4% NaCl, respectively, is 2.5-3.0-fold as high as that of control sample. Moreover, soybean rbcS mRNA was accumulated with diurnal variation but easily influenced by light and low temperature.

  5. Nucleotide sequence encoding the precursor of the small subunit of ribulose 1,5-bisphosphate carboxylase from Lemna gibba L.G-3.

    OpenAIRE

    Stiekema, W J; Wimpee, C F; Tobin, E M

    1983-01-01

    We have sequenced a cDNA clone, pLgSSU, which encodes the small subunit of ribulose 1,5-bisphosphate carboxylase of Lemna gibba L.G-3 a monocot plant. This clone contains a 832 basepair insert which encodes the entire 120 amino acids of the mature small subunit polypeptide (Mr = 14,127). In addition this clone encodes 53 amino acids of the amino terminal transit peptide of the precursor polypeptide and 242 nucleotides of the 3' non-coding region. Comparison of the nucleotide sequence of pLgSS...

  6. Isolation, identification, and synthesis of 2-carboxyarabinitol 1-phosphate, a diurnal regulator of ribulase-bisphosphate carboxylase activity

    International Nuclear Information System (INIS)

    The diurnal change in activity of ribulose 1,5-bisphosphate (Rbu-1,5-P2) carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing); EC 4.1.1.39] of leaves of Phaseolus vulgaris is regulated (in part) by mechanisms that control the level of an endogenous inhibitor that binds tightly to the activated (carbamoylated) form of Rbu-1,5-P2 carboxylase. This inhibitor was extracted from leaves and copurified with the Rbu-1,5-P2 carboxylase of the leaves. Further purification by ion-exchange chromatography, adsorption to purified Rbu-1,5-P2 carboxylase, barium precipitation, and HPLC separation yielded a phosphorylated compound that was a strong inhibitor of Rbu-1,5-P2 carboxylase. The compound was analyzed by GC/MS, 13C NMR, and 1H NMR and shown to be 2-carboxyarabinitol 1-phosphate [(2-C-phosphohydroxymethyl)-D-ribonic acid]. The structure of the isolated compound differs from the Rbu-1,5-P2 carboxylase transition-state analogue 2-carboxyarabinitol 1,5-bisphosphate only by the lack of the C-5 phosphate group. This difference results in a higher binding constant for the monophosphate compared with the bisphosphate. The less tightly bound compound acts in a light-dependent, reversible regulation of Rbu-1,5-P2 carboxylase activity in vivo

  7. Dark/light modulation of ribulose bisphosphate carboxylase activity in plants from different photosynthetic categories

    Energy Technology Data Exchange (ETDEWEB)

    Vu, J.C.V.; Allen, L.H. Jr.; Bowes, G.

    1984-11-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from light-exposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO/sub 3//sup -/ and Mg/sup 2 +/ concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C/sub 3/); P. maximum (C/sub 4/ phosphoenolpyruvate carboxykinase); P. milioides (C/sub 3//C/sub 4/); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C/sub 3/); P. miliaceum (C/sub 4/ NAD malic enzyme); Zea mays and Sorghum bicolor (C/sub 4/ NADP malic enzyme); Moricandia arvensis (C/sub 3//C/sub 4/); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C/sub 3/ species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO/sub 2/ and Mg/sup 2 +/ activation, but which can be converted to an activatable state upon exposure of the leaf to light. 16 references, 2 tables.

  8. Dark/Light modulation of ribulose bisphosphate carboxylase activity in plants from different photosynthetic categories.

    Science.gov (United States)

    Vu, J C; Allen, L H; Bowes, G

    1984-11-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from lightexposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO(3) (-) and Mg(2+) concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C(3)); P. maximum (C(4) phosphoenolpyruvate carboxykinase); P. milioides (C(3)/C(4)); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C(3)); P. miliaceum (C(4) NAD malic enzyme); Zea mays and Sorghum bicolor (C(4) NADP malic enzyme); Moricandia arvensis (C(3)/C(4)); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C(3) species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO(2) and Mg(2+) activation, but which can be converted to an activatable state upon exposure of the leaf to light.

  9. Dark/Light Modulation of Ribulose Bisphosphate Carboxylase Activity in Plants from Different Photosynthetic Categories 1

    Science.gov (United States)

    Vu, J. Cu V.; Allen, Leon H.; Bowes, George

    1984-01-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from lightexposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO3− and Mg2+ concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C3); P. maximum (C4 phosphoenolpyruvate carboxykinase); P. milioides (C3/C4); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C3); P. miliaceum (C4 NAD malic enzyme); Zea mays and Sorghum bicolor (C4 NADP malic enzyme); Moricandia arvensis (C3/C4); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C3 species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO2 and Mg2+ activation, but which can be converted to an activatable state upon exposure of the leaf to light. PMID:16663937

  10. Ribulose-1,5-bisphosphate Carboxylase/Oxygenase content, assimilatory charge, and mesophyll conductance in leaves

    Science.gov (United States)

    Eichelmann; Laisk

    1999-01-01

    The content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) (Et; EC 4.1.1.39) measured in different-aged leaves of sunflower (Helianthus annuus) and other plants grown under different light intensities, varied from 2 to 75 &mgr;mol active sites m-2. Mesophyll conductance (&mgr;) was measured under 1.5% O2, as well as postillumination CO2 uptake (assimilatory charge, a gas-exchange measure of the ribulose-1,5-bisphosphate pool). The dependence of &mgr; on Et saturated at Et = 30 &mgr;mol active sites m-2 and &mgr; = 11 mm s-1 in high-light-grown leaves. In low-light-grown leaves the dependence tended toward saturation at similar Et but reached a &mgr; of only 6 to 8 mm s-1. &mgr; was proportional to the assimilatory charge, with the proportionality constant (specific carboxylation efficiency) between 0.04 and 0.075 &mgr;M-1 s-1. Our data show that the saturation of the relationship between Et and &mgr; is caused by three limiting components: (a) the physical diffusion resistance (a minor limitation), (b) less than full activation of Rubisco (related to Rubisco activase and the slower diffusibility of Rubisco at high protein concentrations in the stroma), and (c) chloroplast metabolites, especially 3-phosphoglyceric acid and free inorganic phosphate, which control the reaction kinetics of ribulose-1,5-bisphosphate carboxylation by competitive binding to active sites. PMID:9880359

  11. Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

    NARCIS (Netherlands)

    Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

    1988-01-01

    The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

  12. Identification of Interactions between Abscisic Acid and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase.

    Directory of Open Access Journals (Sweden)

    Marek M Galka

    Full Text Available Abscisic acid ((+-ABA is a phytohormone involved in the modulation of developmental processes and stress responses in plants. A chemical proteomics approach using an ABA mimetic probe was combined with in vitro assays, isothermal titration calorimetry (ITC, x-ray crystallography and in silico modelling to identify putative (+-ABA binding-proteins in crude extracts of Arabidopsis thaliana. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco was identified as a putative ABA-binding protein. Radiolabelled-binding assays yielded a Kd of 47 nM for (+-ABA binding to spinach Rubisco, which was validated by ITC, and found to be similar to reported and experimentally derived values for the native ribulose-1,5-bisphosphate (RuBP substrate. Functionally, (+-ABA caused only weak inhibition of Rubisco catalytic activity (Ki of 2.1 mM, but more potent inhibition of Rubisco activation (Ki of ~ 130 μM. Comparative structural analysis of Rubisco in the presence of (+-ABA with RuBP in the active site revealed only a putative low occupancy (+-ABA binding site on the surface of the large subunit at a location distal from the active site. However, subtle distortions in electron density in the binding pocket and in silico docking support the possibility of a higher affinity (+-ABA binding site in the RuBP binding pocket. Overall we conclude that (+-ABA interacts with Rubisco. While the low occupancy (+-ABA binding site and weak non-competitive inhibition of catalysis may not be relevant, the high affinity site may allow ABA to act as a negative effector of Rubisco activation.

  13. Large structures at high resolution: the 1.6 A crystal structure of spinach ribulose-1,5-bisphosphate carboxylase/oxygenase complexed with 2-carboxyarabinitol bisphosphate.

    Science.gov (United States)

    Andersson, I

    1996-05-31

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach is a hexadecamer (L8S8, Mr = 550,000) consisting of eight large (L, 475 residues) and eight small subunits (S, 123 residues). High-resolution data collection on crystals with large unit cells is not a trivial task due to the effect of radiation damage and the large number of overlapping reflections when conventional data collection methods are used. In order to minimise these effects, data on rubisco were collected with a giant Weissenberg camera at long crystal to image-plate distances at the synchrotron of the Photon Factory, Japan. Relative to conventional data sets, this experimental arrangement allowed a 20 to 30-fold reduction of the X-ray dose/exposure time for data collection. This paper describes the refined 1.6 A crystal structure of activated rubisco complexed with a transition state analogue, 2-carboxyarabinitol-bisphosphate. The crystallographic asymmetric unit contains an L4S4 unit, representing half of the molecule. The structure presented here is currently the highest resolution structure for any protein of comparable size. Refinement of the model was carried out by restrained least squares techniques without non-crystallographic symmetry averaging. The results show that all L and S subunits have identical three-dimensional structures, and their arrangement within the hexadecamer has no intrinsic asymmetry. A detailed analysis of the high-resolution maps identified 30 differences in the sequence of the small subunit, indicating a larger than usual heterogeneity for this nuclear encoded protein in spinach. No such differences were found in the sequence of the chloroplast encoded large subunit. The transition state analogue is in the cis conformation at the active site suggesting a key role for the carbamate of Lys201 in catalysis. Analysis of the active site around the catalytically essential magnesium ion further indicates that residues in the second liganding sphere of the metal

  14. Degradation of the Large Subunit of Ribulose-1, 5-Bisphosphate Carboxylase/Oxygenase in Wheat Leaves

    Institute of Scientific and Technical Information of China (English)

    Lie-Feng ZHANG; Qi RUI; Lang-Lai XU

    2005-01-01

    The degradation of the large subunit (LSU) of ribulose- 1, 5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) in wheat (Triticum aestivum L. cv. Yangmai 158) leaves was investigated. A 50 kDa fragment, a portion of the LSU of Rubisco, was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with antibody against tobacco Rubisco in crude enzyme extract of young wheat leaves. The appearance of the 50 kDa fragment was most obvious at 30-35 ℃ and pH 5.5. The LSU and its 50 kDa fragment both existed when the crude enzyme extract was incubated for 60 min. The amount of LSU decreased with incubation time from 0 to 3 h in crude enzyme extract. However, the 50 kDa fragment could not be found any pH from 4.5 to 8.5 in chloroplast lysates of young wheat leaves. In addition,through treatment with various inhibitors, reactions were inhibited by cysteine proteinase inhibitor E-64 or leupeptin.

  15. Composition, quaternary structure, and catalytic properties of D-ribulose-1, 5-bisphosphate carboxylase from Euglena gracilis.

    Science.gov (United States)

    McFadden, B A; Lord, J M; Rowe, A; Dilks, S

    1975-05-01

    D-Ribulose-1,5-bisphosphate carboxylase has been purified in one step by sedimenting extracts of autotrophically-grown Euglena gracilis into a linear 0.2-0.8 M sucrose density gradient. The resultant product was pure by the criteria of disc electrophoresis in gels polymerized from 5 or 7.5% acrylamide and sedimentation. The molecular weight of the enzyme estimated by density gradient centrifugation and electrophoresis in gels polymerized from various concentrations of acrylamide was 5.25 X 10(5). The S20,W was 16.4 S. Dissociation and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate established that the enzyme was composed of two types of subunits (mr 50,000 and 15,000). The oligomeric structure was visualized through negative staining and transmission electron microscopy leading to a model for the quaternary structure. Although the enzyme was moderately unstable, the estimated maximal specific activity was 1.6 mumol CO2 fixed min-1 mg protien-1 at 30 degrees C and pH 8.0 Km values were 2.2 m M, 15. 1 MUM and 0.63 mM for Mg2+, ribulose 1,5-bisphosphate, and CO2, respectively, when measured under air. 6-Phospho-D-gluconate was a noncompetitive inhibitor with respect to ribulose 1,5-bisphosphate (Ki = 0.04 mM). Oxygen was a competitive inhibitor with respect to CO2 suggesting that the enzyme was also an oxygenase. The latter was confirmed by experiments showing a molar equivalence between ribulose-1,5-bisphosphate-dependent oxygen consumption and phosphoglycerate production.

  16. Cloning and characterization of the gene product of the form II ribulose-1,5-bisphosphate carboxylase gene of Rhodopseudomonas sphaeroides.

    OpenAIRE

    Muller, E D; Chory, J; Kaplan, S

    1985-01-01

    We report the cloning and characterization of the gene product of the gene for the form II ribulose bisphosphate carboxylase from Rhodopseudomonas sphaeroides. We present evidence that the form II enzyme is encoded by a single gene in R. sphaeroides; however, this gene does hybridize to a second chromosomal locus.

  17. Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag.

    Science.gov (United States)

    Bhaskaran, S; Smith, R H; Finer, J J

    1983-11-01

    Plants obtained from anther culture of the African violet, Saintpaulia ionantha Wendl. ;Shag' and vegetatively cloned copies of the parent anther donor plant were examined for their ploidy and ribulose-1,5-biphosphate carboxylase (RuBPcase) activity. The cloned parent plants were all diploid and did not vary much in their nuclear DNA, chlorophyll, and RuBPcase activity. Some of the anther-derived plants were similar to the parent plants while others were not. Different levels of ploidy were observed among the androgenetic plants. RuBPcase activities higher than that of the parent plants were found in some anther-derived plants. However, there was no direct correlation between ploidy and RuBPcase activity. Expression of nuclear genes from a single parent in the anther-derived plants and it's diploidization or plastid changes during early stages of microsporogenesis or androgenesis are suggested as possible reasons for the variations observed among them. This could be a useful technique to obtain physiological variants which could be agronomically desirable. PMID:16663273

  18. Decline of activity and quantity of ribulose bisphosphate carboxylase/oxygenase and net photosynthesis in ozone-treated potato foliage

    Energy Technology Data Exchange (ETDEWEB)

    Dann, M.S.; Pell, E.J. (Pennsylvania State Univ., University Park (USA))

    1989-09-01

    The effect of ozone (O{sub 3}) on ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv Norland foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters per liter O{sub 3} from 1,000 to 1,600 hours for 4 days in a controlled environment chamber. On day 5, plants were exposed to a 6-hour simulated inversion in which O{sub 3} peaked at 0.12 microliters per liter. Net photosynthesis declined in response to O{sub 3} but recovered to near control levels 3 days after the exposure ended. Rubisco activity and quantity in control potato foliage increased and then decreased during the 12-day interval of the study. In some experiments foliage studied was physiologically mature and Rubisco activity had peaked when O{sub 3} exposure commenced. In those cases, O{sub 3} accelerated the decline in Rubisco activity. When less mature foliage was treated with O{sub 3}, the leaves never achieved the maximal level of Rubisco activity observed in control foliage and also exhibited more rapid decline in initial and total activity. Percent activation of Rubisco (initial/total activity) was not affected significantly by treatment. Quantity of Rubisco decreased in concert with activity. The reduction in the quantity of Rubisco, an important foliage storage protein, could contribute to premature senescence associated with toxicity of this air pollutant.

  19. Simple determination of the CO2/O2 specificity of Ribulose-1,5-bisphosphate carboxylase/oxygenase by the specific radioactivity of [14C] glycerate 3-phosphate

    International Nuclear Information System (INIS)

    A new method is presented for measurement of the CO2/O2 specificity factor of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The [14C]3-phosphoglycerate (PGA) from the Rubisco carboxylase reaction and its dilution by the Rubisco oxygenase reaction was monitored by directly measuring the specific radioactivity of PGA. 14CO2 fixation with Rubisco occurred under two reaction conditions: carboxylase with oxygenase with 40 micromolar CO2 in O2-saturated water and carboxylase only with 160 micromolar CO2 under N2. Detection of the specific radioactivity used the amount of PGA as obtained from the peak area, which was determined by pulsed amperometry following separation by high-performance anion exchange chromatography and the radioactive counts of the [14C]PGA in the same peak. The specificity factor of Rubisco from spinach (Spinacia oleracea L.) (93 ± 4), from the green alga Chlamydomonas reinhardtii (66 ± 1), and from the photosynthetic bacterium Rhodospirillum rubrum (13) were comparable with the published values measured by different methods

  20. Dithiothreitol decreases the thermal stability and unfolding cooperativity of ribulose-1, 5-bisphosphate carboxylase/oxygenase

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Plant rubisco consists of eight large subunits (55 kD) encoded by chloroplast gene and eight small subunits (15 kD) encoded by nuclear gene. There are abundant cysteine residues that do not form disulfide bonds in native rubisco. Differential scanning calorimetry has been used to study some plant rubisco and suggested an irreversible two-state denaturation due to the high cooperativity in subunits. By comparing the data from circular dichroism, fluorescence, differential scanning calorimetry, SDS electrophoresis, and activity assays in the absence or presence of DTT, we suggest that the formation of disulfide bonds in subunits during the early thermal unfolding may increase the thermal stability and the thermal unfolding cooperativity of rubisco.

  1. Electrophoretic assay for ribulose 1,5-bisphosphate carboxylase/oxygenase in guard cells and other leaf cells of Vicia faba L

    Energy Technology Data Exchange (ETDEWEB)

    Tarczynski, M.C.; Outlaw, W.H. Jr.; Arold, N.; Neuhoff, V.; Hampp, R. (Florida State Univ., Tallahassee (USA) Max-Planck-Institute fuer Experimentelle Medizin, Goettingen (West Germany) Universitaet Tuebingen (West Germany))

    1989-04-01

    The ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) contents of guard cells and other cells of Vicia faba L. leaflet were determined. To prevent proteolysis, proteins of frozen protoplast preparations or of cells excised from freeze-dried leaf were extracted directly in a sodium-dodecyl-sulfate-containing solution which was heated immediately after sample addition. Protein profiles of the different cell types were obtained by electrophoresis of the extracts and subsequent densitometry of the stained protein bands. About one-third of the protein of palisade parenchyma and of spongy parenchyma was Rubisco large subunit. Using chlorophyll (Chl):protein ratios previously obtained, we calculate mesophyll contained ca. 22 millimoles Rubisco per mole Chl. In contrast, guard-cell protoplast preparations were calculated to contain from 0.7 to 2.2 millimoles Rubisco per mole Chl. The upper end of this range is an overestimate resulting from contamination by mesophyll and to the method of peak integration. Extracts of excised guard cells were calculated to contain 0.05 to 0.17 millimole Rubisco per mole Chl. We conclude that Rubisco is absent, or virtually so, in guard cells of V. faba.

  2. Phylogeny of 16S rRNA, ribulose 1,5-bisphosphate carboxylase/oxygenase, and adenosine 5'-phosphosulfate reductase genes from gamma- and alphaproteobacterial symbionts in gutless marine worms (oligochaeta) from Bermuda and the Bahamas.

    Science.gov (United States)

    Blazejak, Anna; Kuever, Jan; Erséus, Christer; Amann, Rudolf; Dubilier, Nicole

    2006-08-01

    Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5'-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes.

  3. Phylogeny of 16S rRNA, Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase, and Adenosine 5′-Phosphosulfate Reductase Genes from Gamma- and Alphaproteobacterial Symbionts in Gutless Marine Worms (Oligochaeta) from Bermuda and the Bahamas

    Science.gov (United States)

    Blazejak, Anna; Kuever, Jan; Erséus, Christer; Amann, Rudolf; Dubilier, Nicole

    2006-01-01

    Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5′-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes. PMID:16885306

  4. Determining Photosynthetic Parameters from Leaf CO2 Exchange and Chlorophyll Fluorescence (Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Specificity Factor, Dark Respiration in the Light, Excitation Distribution between Photosystems, Alternative Electron Transport Rate, and Mesophyll Diffusion Resistance.

    Science.gov (United States)

    Laisk, A.; Loreto, F.

    1996-03-01

    Using simultaneous measurements of leaf gas exchange and chlorophyll fluorescence, we determined the excitation partitioning to photosystem II (PSII), the CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase, the dark respiration in the light, and the alternative electron transport rate to acceptors other than bisphosphoglycerate, and the transport resistance for CO2 in the mesophyll cells for individual leaves of herbaceous and tree species. The specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase for CO2 was determined from the slope of the O2 dependence of the CO2 compensation point between 1.5 and 21% O2. Its value, on the basis of dissolved CO2 and O2 concentrations at 25.5[deg]C, varied between 86 and 89. Dark respiration in the light, estimated from the difference between the CO2 compensation point and the CO2 photocompensation point, was about 20 to 50% of the respiration rate in the dark. The excitation distribution to PSII was estimated from the extrapolation of the dependence of the PSII quantum yield on F/Fm to F = 0, where F is steady-state and Fm is pulse-satuarated fluorescence, and varied between 0.45 and 0.6. The alternative electron transport rate was found as the difference between the electron transport rates calculated from fluorescence and from gas exchange, and at low CO2 concentrations and 10 to 21% O2, it was 25 to 30% of the maximum electron transport. The calculated mesophyll diffusion resistance accounted for about 20 to 30% of the total mesophyll resistance, which also includes carboxylation resistance. Whole-leaf photosynthesis is limited by gas phase, mesophyll diffusion, and carboxylation resistances in nearly the same proportion in both herbaceous species and trees. PMID:12226229

  5. Effects of manganese-excess on CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, carbohydrates and photosynthetic electron transport of leaves, and antioxidant systems of leaves and roots in Citrus grandis seedlings

    Directory of Open Access Journals (Sweden)

    Tang Ning

    2010-03-01

    Full Text Available Abstract Background Very little is known about the effects of manganese (Mn-excess on citrus photosynthesis and antioxidant systems. Seedlings of sour pummelo (Citrus grandis were irrigated for 17 weeks with nutrient solution containing 2 μM (control or 500 μM (excess MnSO4. The objective of this study were to understand the mechanisms by which Mn-excess leads to a decrease in CO2 assimilation and to test the hypothesis that Mn-induced changes in antioxidant systems differ between roots and leaves. Results Mn-excess decreased CO2 assimilation and stomatal conductance, increased intercellular CO2 concentration, but did not affect chlorophyll (Chl level. Both initial and total ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco activity in Mn-excess leaves decreased to a lesser extent than CO2 assimilation. Contents of glucose, fructose, starch and total nonstructural carbohydrates did not differ between Mn-excess leaves and controls, while sucrose content was higher in the former. Chl a fluorescence (OJIP transients from Mn-excess leaves showed increased O-step and decreased P-step, accompanied by positive L- and K-bands. Mn-excess decreased maximum quantum yield of primary photochemistry (Fv/Fm and total performance index (PItot,abs, but increased relative variable fluorescence at I-steps (VI and energy dissipation. On a protein basis, Mn-excess leaves displayed higher activities of monodehydroascorbate reductase (MDAR, glutathione reductase (GR, superoxide dismutase (SOD, catalase (CAT and guaiacol peroxidase (GPX and contents of antioxidants, similar ascorbate peroxidase (APX activities and lower dehydroascorbate reductase (DHAR activities; while Mn-excess roots had similar or lower activities of antioxidant enzymes and contents of antioxidants. Mn-excess did not affect malondialdehyde (MDA content of roots and leaves. Conclusions Mn-excess impaired the whole photosynthetic electron transport chain from the donor side of photosystem II

  6. Serine 363 of a Hydrophobic Region of Archaeal Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase from Archaeoglobus fulgidus and Thermococcus kodakaraensis Affects CO2/O2 Substrate Specificity and Oxygen Sensitivity.

    Directory of Open Access Journals (Sweden)

    Nathan E Kreel

    Full Text Available Archaeal ribulose 1, 5-bisphospate carboxylase/oxygenase (RubisCO is differentiated from other RubisCO enzymes and is classified as a form III enzyme, as opposed to the form I and form II RubisCOs typical of chemoautotrophic bacteria and prokaryotic and eukaryotic phototrophs. The form III enzyme from archaea is particularly interesting as several of these proteins exhibit unusual and reversible sensitivity to molecular oxygen, including the enzyme from Archaeoglobus fulgidus. Previous studies with A. fulgidus RbcL2 had shown the importance of Met-295 in oxygen sensitivity and pointed towards the potential significance of another residue (Ser-363 found in a hydrophobic pocket that is conserved in all RubisCO proteins. In the current study, further structure/function studies have been performed focusing on Ser-363 of A. fulgidus RbcL2; various changes in this and other residues of the hydrophobic pocket point to and definitively establish the importance of Ser-363 with respect to interactions with oxygen. In addition, previous findings had indicated discrepant CO2/O2 specificity determinations of the Thermococcus kodakaraensis RubisCO, a close homolog of A. fulgidus RbcL2. It is shown here that the T. kodakaraensis enzyme exhibits a similar substrate specificity as the A. fulgidus enzyme and is also oxygen sensitive, with equivalent residues involved in oxygen interactions.

  7. Mechanism and Significance of Post-Translational Modifications in the Large (LS) and Small (SS) Subunits of Ribulose-1,5 Bisphosphate Carboxylase/Oxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Houtz, Robert, L.

    2012-11-09

    This project focused on a molecular and biochemical characterization of the protein methyltransferases responsible for methylation of the LS and SS in Rubisco, and the associated functional consequences accompanying these modifications. Our results provided some of the most informative structural and mechanistic understandings of SET domain protein methyltransferases. These results also positioned us to provide the first unambiguous assignment of the kinetic reaction mechanism for SET-domain protein methyltransferases, and to design and engineer an alternative substrate for Rubisco LSMT, enabling substrate specificity and functional significance studies. We demonstrated that the minimal substrate recognized by Rubisco LSMT is free lysine as well as monomethyllysine, an observation corroborated both by structural analyses as well as enzymatic activity and subsequent product distribution analyses. Ternary complexes between Rubisco LSMT and free lysine compared to complexes with monomethyllysine demonstrated that the structural basis for multiple methyl group additions is a consequence of hydrogen-bond driven spatial shifts in the amino group of Lys-14, which maintains the direct in-line geometry necessary for SN2 nucleophilic attack. The structural observations are also consistent with the previous proposal that the multiplicity of methyl group additions takes place through a processive mechanism, with successive methyl group additions to an enzyme protein complex which does not disassociate prior to the formation of trimethyllysine. This mechanism has important implications, since the regulation of gene expression by SET domain histone methyltransferases is not only dependent on site-specific lysine methylation, but also the degree of methylation. We examined the kinetic reaction mechanism for three different types of SET domain protein methyltransferases, each under conditions supporting mono-, di-, or trimethyllysine formation corroborated by product analyses. Additionally, the tight initial binding of Rubisco LSMT to Rubisco also allowed us to design a novel immobilized complex between Rubisco and Rubisco LSMT, which allowed for an unambiguous demonstration of the requirement for trimethyllysine formation prior to disassociation of the Rubisco LSMT:Rubisco complex, and therefore proof of the processive mechanism for methyl group transfer. These kinetic studies also demonstrated that an important factor has been overlooked in all kinetic analyses of SET domain protein methyltransferases reported to date. This factor is the influence of the low turnover number for SET domain protein methyltransferases and how, relative to the time-frame of kinetic enzyme assays, this can generate changes in kinetic profiles shifting reciprocal plot patterns from random/ordered bi-bi to the real kinetic reaction mechanism plots of ping-pong. Although the ternary complexes of Rubisco LSMT with S-Adenosylhomocysteine and lysine and monomethyllysine were informative in regard to reaction mechanism, they were not helpful in identifying the mechanism used by Rubisco LSMT for determining substrate specificity. We were unsuccessful at obtaining ternary complexes of Rubisco LSMT with bound synthetic polypeptide substrates, as has been reported for several histone methyltransferases. However, we were able to model a polypeptide sequence corresponding to the N-terminal region of the LS of Rubisco into the apparent substrate binding cleft in Rubisco LSMT. Knowledge of the determinants of polypeptide substrate specificity are important for identifying possible alternate substrates, as well as the possibility of generating more desirable substrates amenable to site-directed mutagenesis experiments unlike Rubisco. We determined that Rubisco LSMT is capable of methylating synthetic polypeptide mimics of the N-terminal region of the LS, both free as well as conjugated to keyhole limpet hemacyanin, but with considerable less efficiency than intact holoenzyme.

  8. Phylogeny of 16S rRNA, Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase, and Adenosine 5′-Phosphosulfate Reductase Genes from Gamma- and Alphaproteobacterial Symbionts in Gutless Marine Worms (Oligochaeta) from Bermuda and the Bahamas

    OpenAIRE

    Blazejak, Anna; Kuever, Jan; Erséus, Christer; Amann, Rudolf; Dubilier, Nicole

    2006-01-01

    Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluore...

  9. Protein (Cyanobacteria): 246918 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 5-bisphosphate carboxylase small subunit Moorea producens 3L MKTLPKERRYETLSYLPPLSDAQIMRQVEYILAEGYIPAIEFNESSEPEIYYWTLWKLPLFKATSPKDVLAEVDECRSEYRDCYIRVVGFDNVKQCQVLSFIIHKPNEGVSRSRW ...

  10. Fructose-2,6-bisphosphate

    DEFF Research Database (Denmark)

    Nielsen, Tom Hamborg; Rung, Jesper Henrik; Villadsen, Dorthe

    2004-01-01

    Fructose-2,6-bisphosphate (Fru-2,6-P2) regulates key reactions of the primary carbohydrate metabolism in all eukaryotes. In plants, Fru-2,6-P2 coordinates the photosynthetic carbon flux into sucrose and starch biosynthesis. The use of transgenic plants has allowed the regulatory models to be tested...... by modifying the Fru-2,6-P2 levels and the enzymes regulated by Fru-2,6-P2. Genes for the bifunctional plant enzyme that synthesizes and degrades Fru-2,6-P2 have been isolated and molecular characterization has provided new insight into structure and molecular regulation of the enzyme. Advances in Fru-2,6-P2...

  11. AcEST: DK947508 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e bisphosphate carboxylase small c... 111 2e-23 tr|A6MZQ8|A6MZQ8_ORYSI Ribulose bisphosphate carboxylase sma...ll c... 111 2e-23 tr|A3CGJ9|A3CGJ9_ORYSJ Ribulose bisphosphate carboxylase small c... 111 2e-23 tr|A2ZJQ0|A2

  12. Fructose 2,6-bisphosphate in rat erythrocytes. Inhibition of fructose 2,6-bisphosphate synthesis and measurement by glycerate 2,3-bisphosphate.

    OpenAIRE

    Sobrino, F; Rider, Mark; Gualberto, A; Hue, Louis

    1987-01-01

    The concentration of fructose 2,6-bisphosphate found in freshly isolated erythrocytes was below the limit of detection (20 pmol/ml of packed cells). However, it increased to about 250 pmol/ml of cells when erythrocytes were incubated with glucose at pH 6.9, but not at pH 7.4 or 8.2. This could be explained by variations in the content of glycerate 2,3-bisphosphate, which was found to inhibit 6-phosphofructo-2-kinase, the enzyme responsible for fructose 2,6-bisphosphate synthesis. Glycerate 2,...

  13. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    Science.gov (United States)

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity. PMID:26936271

  14. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    Science.gov (United States)

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity.

  15. Phosphatidylinositol-bisphosphate regulates intercellular coupling in cardiac myocytes

    DEFF Research Database (Denmark)

    Hofgaard, Johannes P; Banach, Kathrin; Mollerup, Sarah;

    2008-01-01

    Changes in the lipid composition of cardiac myocytes have been reported during cardiac hypertrophy, cardiomyopathy, and infarction. Because a recent study indicates a relation between low phosphatidylinositol-bisphosphate (PIP(2)) levels and reduced intercellular coupling, we tested the hypothesis...

  16. Regulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase: product inhibition, cooperativity, and magnesium activation.

    Science.gov (United States)

    Hazra, Suratna; Henderson, J Nathan; Liles, Kevin; Hilton, Matthew T; Wachter, Rebekka M

    2015-10-01

    In many photosynthetic organisms, tight-binding Rubisco inhibitors are released by the motor protein Rubisco activase (Rca). In higher plants, Rca plays a pivotal role in regulating CO2 fixation. Here, the ATPase activity of 0.005 mm tobacco Rca was monitored under steady-state conditions, and global curve fitting was utilized to extract kinetic constants. The kcat was best fit by 22.3 ± 4.9 min(-1), the Km for ATP by 0.104 ± 0.024 mm, and the Ki for ADP by 0.037 ± 0.007 mm. Without ADP, the Hill coefficient for ATP hydrolysis was extracted to be 1.0 ± 0.1, indicating noncooperative behavior of homo-oligomeric Rca assemblies. However, the addition of ADP was shown to introduce positive cooperativity between two or more subunits (Hill coefficient 1.9 ± 0.2), allowing for regulation via the prevailing ATP/ADP ratio. ADP-mediated activation was not observed, although larger amounts led to competitive product inhibition of hydrolytic activity. The catalytic efficiency increased 8.4-fold upon cooperative binding of a second magnesium ion (Hill coefficient 2.5 ± 0.5), suggesting at least three conformational states (ATP-bound, ADP-bound, and empty) within assemblies containing an average of about six subunits. The addition of excess Rubisco (24:1, L8S8/Rca6) and crowding agents did not modify catalytic rates. However, high magnesium provided for thermal Rca stabilization. We propose that magnesium mediates the formation of closed hexameric toroids capable of high turnover rates and amenable to allosteric regulation. We suggest that in vivo, the Rca hydrolytic activity is tuned by fluctuating [Mg(2+)] in response to changes in available light.

  17. Purification and Properties of Phosphoenolpyruvate Carboxylase from Immature Pods of Chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Singal, H R; Singh, R

    1986-02-01

    Phosphoenolpyruvate carboxylase (EC 4.1.1.31) was purified to homogeneity with about 29% recovery from immature pods of chickpea using ammonium sulfate fractionation, DEAE-cellulose chromatography, and gel filtration through Sephadex G-200. The purified enzyme with molecular weight of about 200,000 daltons was a tetramer of four identical subunits and exhibited maximum activity at pH 8.1. Mg(2+) ions were specifically required for the enzyme activity. The enzyme showed typical hyperbolic kinetics with phosphoenolpyruvate with a K(m) of 0.74 millimolar, whereas sigmoidal response was observed with increasing concentrations of HCO(3) (-) with S(0.5) value as 7.6 millimolar. The enzyme was activated by inorganic phosphate and phosphate esters like glucose-6-phosphate, alpha-glycerophosphate, 3-phosphoglyceric acid, and fructose-1,6-bisphosphate, and inhibited by nucleotide triphosphates, organic acids, and divalent cations Ca(2+) and Mn(2+). Oxaloacetate and malate inhibited the enzyme noncompetitively. Glucose-6-phosphate reversed the inhibitory effects of oxaloacetate and malate.

  18. Structure of Toxoplasma gondii fructose-1,6-bisphosphate aldolase

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, Lauren E.; Bosch, Jürgen, E-mail: jbosch@jhu.edu [Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205 (United States); Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205 (United States)

    2014-08-29

    The structure of T. gondii fructose-1,6-bisphosphate aldolase, a glycolytic enzyme and structural component of the invasion machinery, was determined to a resolution of 2.0 Å. The apicomplexan parasite Toxoplasma gondii must invade host cells to continue its lifecycle. It invades different cell types using an actomyosin motor that is connected to extracellular adhesins via the bridging protein fructose-1,6-@@bisphosphate aldolase. During invasion, aldolase serves in the role of a structural bridging protein, as opposed to its normal enzymatic role in the glycolysis pathway. Crystal structures of the homologous Plasmodium falciparum fructose-1,6-bisphosphate aldolase have been described previously. Here, T. gondii fructose-1,6-bisphosphate aldolase has been crystallized in space group P22{sub 1}2{sub 1}, with the biologically relevant tetramer in the asymmetric unit, and the structure has been determined via molecular replacement to a resolution of 2.0 Å. An analysis of the quality of the model and of the differences between the four chains in the asymmetric unit and a comparison between the T. gondii and P. falciparum aldolase structures is presented.

  19. Structural analysis, plastid localization, and expression of the biotin carboxylase subunit of acetyl-coenzyme A carboxylase from tobacco.

    Science.gov (United States)

    Shorrosh, B S; Roesler, K R; Shintani, D; van de Loo, F J; Ohlrogge, J B

    1995-06-01

    Acetyl-coenzyme A carboxylase (ACCase, EC 6.4.1.2) catalyzes the synthesis of malonyl-coenzyme A, which is utilized in the plastid for de novo fatty acid synthesis and outside the plastid for a variety of reactions, including the synthesis of very long chain fatty acids and flavonoids. Recent evidence for both multifunctional and multisubunit ACCase isozymes in dicot plants has been obtained. We describe here the isolation of a tobacco (Nicotiana tabacum L. cv bright yellow 2 [NT1]) cDNA clone (E3) that encodes a 58.4-kD protein that shares 80% sequence similarity and 65% identity with the Anabaena biotin carboxylase subunit of ACCase. Similar to other biotin carboxylase subunits of acetyl-CoA carboxylase, the E3-encoded protein contains a putative ATP-binding motif but lacks a biotin-binding site (methionine-lysine-methionine or methionine-lysine-leucine). The deduced protein sequence contains a putative transit peptide whose function was confirmed by its ability to direct in vitro chloroplast uptake. The subcellular localization of this biotin carboxylase has also been confirmed to be plastidial by western blot analysis of pea (Pisum sativum), alfalfa (Medicago sativa L.), and castor (Ricinus communis L.) plastid preparations. Northern blot analysis indicates that the plastid biotin carboxylase transcripts are expressed at severalfold higher levels in castor seeds than in leaves. PMID:7610168

  20. Expression of bovine vitamin K-dependent carboxylase activity in baculovirus-infected insect cells.

    Science.gov (United States)

    Roth, D A; Rehemtulla, A; Kaufman, R J; Walsh, C T; Furie, B; Furie, B C

    1993-09-15

    A vitamin K-dependent carboxylase has recently been purified from bovine liver microsomes and candidate cDNA clones have been isolated. Definitive identification of the carboxylase remains circumstantial since expression of candidate carboxylase cDNAs in mammalian cells is confounded by the presence of endogenous carboxylase activity. To overcome this problem, a recombinant strain of baculovirus (Autographa california nuclear polyhedrosis virus, AcMNPV) encoding a putative carboxylase (vbCbx/AcMNPV) was used to infect Sf9 insect cells, which we demonstrate have no endogenous carboxylase activity. Infection with vbCbx/AcMNPV conferred vitamin K-dependent carboxylase activity to Sf9 insect cells. Carboxylase activity was demonstrated to peak 2-3 days after infection with vbCbx/AcMNPV. Metabolic radiolabeling with L-[35S]methionine revealed that the 90-kDa recombinant protein is the major protein synthesized at the time of peak activity after infection. An anti-peptide antibody directed against residues 86-99 reacted with bovine liver carboxylase on Western blot analysis and immunoprecipitated recombinant carboxylase from infected Sf9 microsomal protein preparations. Since Sf9 insect cells lack endogenous vitamin K-dependent carboxylase activity, expression of carboxylase activity in Sf9 insect cells with recombinant baculovirus demonstrates that the protein encoded by this cDNA is a vitamin K-dependent gamma-glutamyl carboxylase. PMID:8378308

  1. Structure of fructose bisphosphate aldolase from Encephalitozoon cuniculi

    International Nuclear Information System (INIS)

    The eukaryotic parasite E. cuniculi expresses a fructose bisphosphate aldolase that crystallizes readily in the presence of the partial substrate analog phosphate. This aldolase–phosphate structure and that of the sugar-bound Schiff base are reported. E. cuniculi aldolase displays a dimeric structure rather than the expected tetrameric quaternary structure. Fructose bisphosphate aldolose (FBPA) enzymes have been found in a broad range of eukaryotic and prokaryotic organisms. FBPA catalyses the cleavage of fructose 1,6-bisphosphate into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. The SSGCID has reported several FBPA structures from pathogenic sources. Bioinformatic analysis of the genome of the eukaryotic microsporidian parasite Encephalitozoon cuniculi revealed an FBPA homolog. The structures of this enzyme in the presence of the native substrate FBP and also with the partial substrate analog phosphate are reported. The purified enzyme crystallized in 90 mM Bis-Tris propane pH 6.5, 18% PEG 3350, 18 mM NaKHPO4, 10 mM urea for the phosphate-bound form and 100 mM Bis-Tris propane pH 6.5, 20% PEG 3350, 20 mM fructose 1,6-bisphosphate for the FBP-bound form. In both cases protein was present at 25 mg ml−1 and the sitting-drop vapour-diffusion method was used. For the FBP-bound form, a data set to 2.37 Å resolution was collected from a single crystal at 100 K. The crystal belonged to the orthorhombic space group C2221, with unit-cell parameters a = 121.46, b = 135.82, c = 61.54 Å. The structure was refined to a final free R factor of 20.8%. For the phosphate-bound form, a data set was collected to 2.00 Å resolution. The space group was also C2221 and the unit-cell parameters were a = 121.96, b = 137.61, c = 62.23 Å. The structure shares the typical barrel tertiary structure reported for previous FBPA structures and exhibits the same Schiff base in the active site. The quaternary structure is dimeric. This work provides a direct experimental result

  2. The source and characteristics of chemiluminescence associated with the oxygenase reaction catalyzed by Mn(2+)-ribulosebisphosphate carboxylase.

    Science.gov (United States)

    Lilley, R M; Riesen, H; Andrews, T J

    1993-07-01

    We confirm the observation of Mogel and McFadden (Mogel, S.N., and McFadden, B. A. (1990) Biochemistry 29, 8333-8337) that ribulosebisphosphate carboxylase/oxygenase (rubisco) exhibits chemiluminescence while catalyzing its oxygenase reaction in the presence of Mn2+. However, our results with the spinach and Rhodospirillum rubrum enzymes differ markedly in the following respects. 1) Chemiluminescence intensity was directly proportional to enzyme concentration and behaved as if representing the rate of oxygenase catalysis. 2) The wavelength spectrum peaked at about 770 nm and extended beyond 810 nm. This seems inconsistent with chemiluminescence generated by simultaneous decay of pairs of singlet O2 molecules. It is consistent with manganese(II) luminescence and we discuss its possible sources. The time course of chemiluminescence (resolution, 0.25 s) was distinctively different for spinach and R. rubrum enzymes during the initial 5 s of catalysis, with the bacterial enzyme exhibiting a pronounced initial "burst." Chemiluminescence by the spinach enzyme responded to substrate concentrations in a manner consistent with known oxygenase properties, exhibiting Michaelis-Menten kinetics with ribulose-1,5-bisphosphate (Km 400 nM). Chemiluminescence required carbamylated enzyme with Mn2+ bound at the active site (activation energy, -57.1 KJ.mol-1). As an indicator of oxygenase activity, chemiluminescence represents an improvement over oxygen electrode measurements in response time and sensitivity by factors of at least 100. PMID:8314755

  3. Pyruvate carboxylase is expressed in human skeletal muscle

    DEFF Research Database (Denmark)

    Minet, Ariane D; Gaster, Michael

    2010-01-01

    Pyruvate carboxylase (PC) is a mitochondrial enzyme that catalyses the carboxylation of pyruvate to oxaloacetate thereby allowing supplementation of citric acid cycle intermediates. The presence of PC in skeletal muscle is controversial. We report here, that PC protein is easily detectable...

  4. Hybrid Structure of a Dynamic Single-Chain Carboxylase from Deinococcus radiodurans.

    Science.gov (United States)

    Hagmann, Anna; Hunkeler, Moritz; Stuttfeld, Edward; Maier, Timm

    2016-08-01

    Biotin-dependent acyl-coenzyme A (CoA) carboxylases (aCCs) are involved in key steps of anabolic pathways and comprise three distinct functional units: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and carboxyl transferase (CT). YCC multienzymes are a poorly characterized family of prokaryotic aCCs of unidentified substrate specificity, which integrate all functional units into a single polypeptide chain. We employed a hybrid approach to study the dynamic structure of Deinococcus radiodurans (Dra) YCC: crystal structures of isolated domains reveal a hexameric CT core with extended substrate binding pocket and a dimeric BC domain. Negative-stain electron microscopy provides an approximation of the variable positioning of the BC dimers relative to the CT core. Small-angle X-ray scattering yields quantitative information on the ensemble of Dra YCC structures in solution. Comparison with other carrier protein-dependent multienzymes highlights a characteristic range of large-scale interdomain flexibility in this important class of biosynthetic enzymes.

  5. Molecular cloning and characterization of a cotton phosphoen01pyruVate carboxylase gene

    Institute of Scientific and Technical Information of China (English)

    Zhixin Qiao; Jin-Yuan Liu

    2008-01-01

    Phosphoenolpyruvate carboxylase(PEPC)plays diverse physiological functions during plant development.In this study,a new phosphoenolpyruvate carboxylase gene GhPEPC2 is isolated from cotton(Gossypium hirsutum CV.zhongmian 35)by RACE-PCR.The cloned eDNA of GhPEPC2 is 3364 bp in length,and has an open reading frame of 2913 bp,encoding for 971 putative amino acids with a calculated molecular mass of 110.6 kD and pI of 5.56.The deduced amino acid sequence Of GhPEPC2 shares high similarity with other reported plant PEPCs.Southern blot analysis indicates that the cotton PEPC exists as a small gene family and the GhPEPC2 might have two copies in the cotton genome.The semi-quantitative RT-PCR reveals that GhPEPC2 constitutively expresses in all the tissues of cotton and accumulated highly in roots.flowers and embryos but relatively low in stems and fibers.In addition.the recombinant GhPEPC2 has been purified by expressing it in Escherichia coli and the catalytic properties of it were also investigated.The results showed that GhPEPC2 is a typical C3 PEPC with a higher Km(83.6 μM)and lower Vmax(8.0 μmol min-1mg-1)compared with the C3 PEPCs previously reported.

  6. Changes in mRNA levels and polypeptide subunits of ribulose 1,5-bisphosphate carboxylase in response to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Pea plants (Pisum sativum L., cv. Greenfeast) were grown for 17d (150 μmol photons m−2 s−1; 12h light/12 h dark) and then exposed to moderate levels of supplementary ultraviolet-B radiation (UV-B: 280–320 nm) during the light cycle. The total soluble leaf protein, maximum Rubisco activity, polypeptide and mRNA transcript levels for Rubisco subunits were then determined in the mature third leaf pair from the base of the plants. Total soluble protein per unit leaf area showed little change after 1 d but declined by 33% during 3d of UV-B exposure. However, there was no change on a unit chlorophyll basis. Total RNA per unit area declined by 15% and 37% after 1 or 3d of UV-B treatment, respectively. Maximum Rubisco activity declined by 38% after 1 d and 71% after 3d of UV-B exposure. Rubisco polypeptide subunits showed some decrease (∼16%) after 1d exposure, but declined by 56% over 3d. The decrease in Rubisco is probably the major reason for the reduction in soluble protein. In contrast to the relatively slow decline in total soluble protein and Rubisco, the level of the mRNA transcripts for both rbc L and rbc S showed a dramatic decrease within hours of UV-B exposure. The mRNA transcripts for rbc S were reduced to >20% of control values after 4h of UV-B exposure, while the rbc L transcripts were reduced by 60% after 8h. Further exposure to UV-B reduced the mRNA transcripts to either trace or undetectable levels. The decrease in rbc S mRNA levels with the UV-B exposure can be partially ameliorated by higher photosynthetically active irradiance during the period of UV-B exposure. Plants that were exposed to supplementary UV-B radiation for short periods (4h or 8h) and returned to control conditions, showed no recovery after 24h. However, after a further 2d, the rbc L and rbc S mRNA transcripts had recovered to ca. 60% of the control values, showing that the effect upon the mRNA transcripts is a reversible response. (author)

  7. Impact of ozone on the activity and quantity of ribulose bisphosphate carboxylase/oxygenase in potato foliage and its relation to premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Dann, M.S.

    1988-01-01

    Plants, 26 days old, were exposed to O{sub 3} for five days in a controlled environment chamber. Initial and total activities and quantity of enzyme declined in both O{sub 3}-treated and control plants. Ozone accelerated the decline and produced a significantly greater decrease in activity and quantity by the fifth day of O{sub 3} exposure. Percent activation of the enzyme did not change. Enzyme activity and quantity of O{sub 3}-treated plants remained below control levels throughout a seven-day post-exposure observation period. Ozone may accelerate the decline in rubisco by increasing enzyme acceptability to proteases. To test this hypothesis, rubisco was purified from Norland potato foliage and the enzyme exposed to O{sub 3} or oxygen (O{sub 2}) in vitro. Following oxidant treatment, the extract was treated with exogenous protease. Oxidant treatment reduced the quantity of rubisco an average of 15%. Addition of protease further reduced the quantity by another 30% after O{sub 3} but no O{sub 2} treatment.

  8. Regulation of fructose 2,6-bisphosphate concentration in white adipose tissue.

    OpenAIRE

    Rider, Mark; Hue, Louis

    1985-01-01

    Injection of insulin to fed rats diminished the concentration of fructose 2,6-bisphosphate in white adipose tissue. Incubation of epididymal fat-pads or adipocytes with insulin stimulated lactate release and sugar detritiation and also decreased fructose 2,6-bisphosphate concentration. Such a decrease was, however, not observed in fat-pads from starved or alloxan-diabetic rats. Incubation of adipocytes from fed rats with various concentrations of glucose or fructose led to a dose-dependent ri...

  9. Control of liver 6-phosphofructokinase by fructose 2,6-bisphosphate and other effectors.

    OpenAIRE

    Van Schaftingen, Emile; Jett, M F; Hue, Louis; Hers, H G

    1981-01-01

    Rat liver 6-phosphofructokinase (ATP-D-fructose-6-phosphate 1-phosphotransferase, EC 2.7.1.11) was partially purified free of interfering enzymes by a rapid procedure. Fructose 2,6-bisphosphate, at micromolar concentrations, greatly stimulated the enzyme by increasing its affinity for fructose 6-phosphate and relieving the inhibition by ATP. Its action was synergistic with that of AMP. As a stimulator of liver phosphofructokinase, fructose 2,6-bisphosphate was approximately 1000- and 2500-fol...

  10. Structural and evolutionary relationships among RuBisCOs inferred from their large and small subunits.

    Science.gov (United States)

    Xiang, Fu; Fang, Yuanping; Xiang, Jun

    2016-01-01

    Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is the key enzyme to assimilate CO(2) into the biosphere. The nonredundant structural data sets for three RuBisCO domain superfamilies, i.e. large subunit C-terminal domain (LSC), large subunit N-terminal domain (LSN) and small subunit domain (SS), were selected using QR factorization based on the structural alignment with QH as the similarity measure. The structural phylogenies were then constructed to investigate a possible functional significance of the evolutionary diversification. The LSC could have occurred in both bacteria and archaea, and has evolved towards increased complexity in both bacteria and eukaryotes with a 4-helix-2-helix-2-helix bundle being extended into a 5-helix-3-helix-3-helix one at the LSC carboxyl-terminus. The structural variations of LSN could have originated not only in bacteria with a short coil, but also in eukaryotes with a long one. Meanwhile, the SS dendrogram can be contributed to the structural variations at the βA-βB-loop region. All the structural variations observed in the coil regions have influence on catalytic performance or CO(2)/O(2) selectivities of RuBisCOs from different species. Such findings provide insights on RuBisCO improvements. PMID:27049618

  11. Fructose 1,6-bisphosphate aldolase activity is essential for synthesis of alginate from glucose by Pseudomonas aeruginosa.

    OpenAIRE

    Banerjee, P C; Vanags, R I; Chakrabarty, A M; Maitra, P. K.

    1985-01-01

    We have isolated a mutant of Pseudomonas aeruginosa deficient in fructose 1,6-bisphosphate aldolase activity. This mutant, similar to the mutants deficient in any of the Entner-Doudoroff pathway enzymes, does not allow appreciable alginate formation from glucose and gluconate, but allows alginate synthesis from mannitol and fructose. This suggests that glucose and gluconate must be converted to fructose 1,6-bisphosphate via the Entner-Doudoroff pathway enzymes and fructose 1,6-bisphosphate al...

  12. Experiments on the formation of carboxylase and thiamine pyrophosphate in living bakers' yeast

    NARCIS (Netherlands)

    Leijnse, B.; Terpstra, W.

    1951-01-01

    The formation of carboxylase by living bakers' yeast was demonstrated upon incubation of the yeast with either thiamine or 2-methyl-4-amino-5-ethoxymethylpyrimidine, in the presence and in the absence of glucose. Carboxylase is also formed upon incubation of the yeast with NH4 sulfate and glucose. I

  13. The dynamic organization of fungal acetyl-CoA carboxylase

    Science.gov (United States)

    Hunkeler, Moritz; Stuttfeld, Edward; Hagmann, Anna; Imseng, Stefan; Maier, Timm

    2016-04-01

    Acetyl-CoA carboxylases (ACCs) catalyse the committed step in fatty-acid biosynthesis: the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. They are important regulatory hubs for metabolic control and relevant drug targets for the treatment of the metabolic syndrome and cancer. Eukaryotic ACCs are single-chain multienzymes characterized by a large, non-catalytic central domain (CD), whose role in ACC regulation remains poorly characterized. Here we report the crystal structure of the yeast ACC CD, revealing a unique four-domain organization. A regulatory loop, which is phosphorylated at the key functional phosphorylation site of fungal ACC, wedges into a crevice between two domains of CD. Combining the yeast CD structure with intermediate and low-resolution data of larger fragments up to intact ACCs provides a comprehensive characterization of the dynamic fungal ACC architecture. In contrast to related carboxylases, large-scale conformational changes are required for substrate turnover, and are mediated by the CD under phosphorylation control.

  14. Cloning and Sequencing of a Full-Length cDNA Encoding the RuBPCase Small Subunit (RbcS)in Tea (Camellia sinensis)

    Institute of Scientific and Technical Information of China (English)

    YE Ai-hua; JIANG Chang-jun; ZHU Lin; YU Mei; WANG Zhao-xia; DENG Wei-wei; WEI Chao-lin

    2009-01-01

    This study was aimed to isolate ribulose-l,5-bisphosphate carboxylase/oxygenase small subunit (RbcS) from tea plant [Camellia sinensis (L.) O. Kuntze]. In the study of transcriptional profiling of gene expression from tea flower bud development stage by cDNA-AFLP (cDNA amplified fragment length polymorphism), we have isolated some transcript-derived fragments (TDFs) occurring in both the young and mature flower bud. One of them showed a high degree of similarity to RbcS. Based on the fragment, the full length of RbcS with 769-bp (EF011075) cDNA was obtained via rapid amplification of cDNA ends (RACE). It contained an open reading frame of 176 amino acids consisting of a chloroplast transit peptide with 52 amino acids and a mature protein of 124 amino acids. The amino acids sequence presented a high identity to those of other plant RbcS genes. It also contains three conserved domains and a protein kinase C phosphorylation site, one tyrosine kinase phosphorylation site and two N-myristoylation sites. Analysis by RT-PCR showed that the expression of RbcS in tea from high to low was leaf, young stem, young flower bud and mature flower bud, respectively. The isolation of the tea Rubisco small subunit gene establishes a good foundation for further study on the photosynthesis of tea plant.

  15. Influence of nitrogen enrichment on size-fractionated in vitro carboxylase activities of phytoplankton from Thau Lagoon (Coastal Mediterranean Lagoon, France)

    OpenAIRE

    Fouilland, Eric; Descolas Gros, Chantal; Collos, Yves; Vaquer A, André; Souchu, Philippe; Gasc, Anne; Bibent, Bertrand; Pons, Virginie

    2002-01-01

    The influence of dissolved inorganic and organic nitrogen (DIN and DON) enrichments on pools of enzymes responsible for CO2 fixation by the Calvin-Benson (Rubisco) and beta-carboxylation pathways (beta-carboxylases) were studied in a natural plankton assemblage. The plankton community from a coastal Mediterranean lagoon were incubated in situ for 24 h with initially ammonium, nitrate and DON (taurine) enrichments and compared to a control without any enrichment. An increase of small picophyto...

  16. Increased expression of fatty acid synthase and acetyl-CoA carboxylase in the prefrontal cortex and cerebellum in the valproic acid model of autism

    Science.gov (United States)

    Chen, Jianling; Wu, Wei; Fu, Yingmei; Yu, Shunying; Cui, Donghong; Zhao, Min; Du, Yasong; Li, Jijun; Li, Xiaohong

    2016-01-01

    The primary aim of the present study was to investigate alterations in enzymes associated with fatty acid synthesis, namely fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), in the prefrontal cortex and cerebellum of the valproic acid (VPA)-induced animal model of autism. In this model, pregnant rats were given a single intraperitoneal injection of VPA, and prefrontal cortex and cerebellum samples from their pups were analyzed. The results of western blotting and reverse transcription-quantitative polymerase chain reaction analyses demonstrated that the protein and mRNA expression levels of FASN, ACC and phospho-ACC (pACC) were increased in the prefrontal cortex and cerebellum of the VPA model of autism. Furthermore, in the prefrontal cortex and cerebellum of the VPA model of autism, AMPK expression is increased, whereas PI3K and Akt expression are unchanged. This suggests that disorder of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/FASN and/or adenosine 5′-monophosphate-activated protein kinase (AMPK)/ACC pathway may be involved in the pathogenesis of autism. It is hypothesized that fatty acid synthesis participates in autism through PI3K/Akt/FASN and AMPK/ACC pathways. PMID:27602061

  17. Modification of Rhizopus lactate dehydrogenase for improved resistance to fructose 1,6-bisphosphate

    Science.gov (United States)

    Rhizopus oryzae is frequently used for fermentative production of lactic acid. We determined that one of the key enzymes, lactate dehydrogenase (LDH), involved in synthesis of lactic acid by R. oryzae was significantly inhibited by fructose 1,6-bisphosphate (FBP) at physiological concentrations. Thi...

  18. Decreased renal vitamin K-dependent γ-glutamyl carboxylase activity in calcium oxalate calculi patients

    Institute of Scientific and Technical Information of China (English)

    陈俊汇; 刘继红; 章咏裳; 叶章群; 王少刚

    2003-01-01

    Objective To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis. Methods Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy. The renal carboxylase activity was evaluated as the radioactivity of [14C] labeled sodium bicarbonate in carboxylic reactions in vitro using β-liquid scintillation counting. Results Significantly reduced activity of renal vitamin K-dependent γ-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P<0.01). Conclusion It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis.

  19. Pyruvate carboxylase deficiency: An underestimated cause of lactic acidosis

    Directory of Open Access Journals (Sweden)

    F. Habarou

    2015-03-01

    Full Text Available Pyruvate carboxylase (PC is a biotin-containing mitochondrial enzyme that catalyzes the conversion of pyruvate to oxaloacetate, thereby being involved in gluconeogenesis and in energy production through replenishment of the tricarboxylic acid (TCA cycle with oxaloacetate. PC deficiency is a very rare metabolic disorder. We report on a new patient affected by the moderate form (the American type A. Diagnosis was nearly fortuitous, resulting from the revision of an initial diagnosis of mitochondrial complex IV (C IV defect. The patient presented with severe lactic acidosis and pronounced ketonuria, associated with lethargy at age 23 months. Intellectual disability was noted at this time. Amino acids in plasma and organic acids in urine did not show patterns of interest for the diagnostic work-up. In skin fibroblasts PC showed no detectable activity whereas biotinidase activity was normal. We had previously reported another patient with the severe form of PC deficiency and we show that she also had secondary C IV deficiency in fibroblasts. Different anaplerotic treatments in vivo and in vitro were tested using fibroblasts of both patients with 2 different types of PC deficiency, type A (patient 1 and type B (patient 2. Neither clinical nor biological effects in vivo and in vitro were observed using citrate, aspartate, oxoglutarate and bezafibrate. In conclusion, this case report suggests that the moderate form of PC deficiency may be underdiagnosed and illustrates the challenges raised by energetic disorders in terms of diagnostic work-up and therapeutical strategy even in a moderate form.

  20. Rational Design Synthesis and Evaluation of New Selective Inhibitors of Microbial Class II (Zinc Dependent) Fructose Bis-phosphate Aldolases

    Energy Technology Data Exchange (ETDEWEB)

    R Daher; M Coincon; M Fonvielle; P Gest; M Guerin; M Jackson; J Sygusch; M Therisod

    2011-12-31

    We report the synthesis and biochemical evaluation of several selective inhibitors of class II (zinc dependent) fructose bis-phosphate aldolases (Fba). The products were designed as transition-state analogues of the catalyzed reaction, structurally related to the substrate fructose bis-phosphate (or sedoheptulose bis-phosphate) and based on an N-substituted hydroxamic acid, as a chelator of the zinc ion present in active site. The compounds synthesized were tested on class II Fbas from various pathogenic microorganisms and, by comparison, on a mammalian class I Fba. The best inhibitor shows Ki against class II Fbas from various pathogens in the nM range, with very high selectivity (up to 105). Structural analyses of inhibitors in complex with aldolases rationalize and corroborate the enzymatic kinetics results. These inhibitors represent lead compounds for the preparation of new synthetic antibiotics, notably for tuberculosis prophylaxis.

  1. Structure of a Class I Tagatose-1,6-bisphosphate Aldolase - Investigation into an Apparent Loss of Stereospecificity

    Energy Technology Data Exchange (ETDEWEB)

    LowKam, C.; Liotard, B; Sygusch, J

    2010-01-01

    Tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes is a class I aldolase that exhibits a remarkable lack of chiral discrimination with respect to the configuration of hydroxyl groups at both C3 and C4 positions. The enzyme catalyzes the reversible cleavage of four diastereoisomers (fructose 1,6-bisphosphate (FBP), psicose 1,6-bisphosphate, sorbose 1,6-bisphosphate, and tagatose 1,6-bisphosphate) to dihydroxyacetone phosphate (DHAP) and d-glyceraldehyde 3-phosphate with high catalytic efficiency. To investigate its enzymatic mechanism, high resolution crystal structures were determined of both native enzyme and native enzyme in complex with dihydroxyacetone-P. The electron density map revealed a ({alpha}/{beta}){sub 8} fold in each dimeric subunit. Flash-cooled crystals of native enzyme soaked with dihydroxyacetone phosphate trapped a covalent intermediate with carbanionic character at Lys{sup 205}, different from the enamine mesomer bound in stereospecific class I FBP aldolase. Structural analysis indicates extensive active site conservation with respect to class I FBP aldolases, including conserved conformational responses to DHAP binding and conserved stereospecific proton transfer at the DHAP C3 carbon mediated by a proximal water molecule. Exchange reactions with tritiated water and tritium-labeled DHAP at C3 hydrogen were carried out in both solution and crystalline state to assess stereochemical control at C3. The kinetic studies show labeling at both pro-R and pro-S C3 positions of DHAP yet detritiation only at the C3 pro-S-labeled position. Detritiation of the C3 pro-R label was not detected and is consistent with preferential cis-trans isomerism about the C2-C3 bond in the carbanion as the mechanism responsible for C3 epimerization in tagatose-1,6-bisphosphate aldolase.

  2. A Patient With Pyruvate Carboxylase Deficiency and Nemaline Rods on Muscle Biopsy

    DEFF Research Database (Denmark)

    Unal, Ozlem; Orhan, Diclehan; Ostergaard, Elsebet;

    2013-01-01

    and nemaline rods detected on muscle biopsy. The nemaline rods may be due to cellular energy shortage and altered energy metabolism in pyruvate carboxylase deficiency, similar to that in the previously reported patients. The mechanism of nemaline rod formation may be associated with the role of pyruvate...

  3. Identification and expression of fructose-1,6-bisphosphate aldolase genes and their relations to oil content in developing seeds of tea oil tree (Camellia oleifera)

    Science.gov (United States)

    Tea oil tree (Camellia oleifera, Co) provides a fine edible oil source in China. Tea oil from the seeds is very beneficial to human health. Fructose-1,6-bisphosphate aldolase (FBA) hydrolyzes fructose-1,6-bisphosphate into dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, two critical metab...

  4. Identification of nuclear phosphatidylinositol 4,5-bisphosphate-interacting proteins by neomycin extraction.

    Science.gov (United States)

    Lewis, Aurélia E; Sommer, Lilly; Arntzen, Magnus Ø; Strahm, Yvan; Morrice, Nicholas A; Divecha, Nullin; D'Santos, Clive S

    2011-02-01

    Considerable insight into phosphoinositide-regulated cytoplasmic functions has been gained by identifying phosphoinositide-effector proteins. Phosphoinositide-regulated nuclear functions however are fewer and less clear. To address this, we established a proteomic method based on neomycin extraction of intact nuclei to enrich for nuclear phosphoinositide-effector proteins. We identified 168 proteins harboring phosphoinositide-binding domains. Although the vast majority of these contained lysine/arginine-rich patches with the following motif, K/R-(X(n= 3-7)-K-X-K/R-K/R, we also identified a smaller subset of known phosphoinositide-binding proteins containing pleckstrin homology or plant homeodomain modules. Proteins with no prior history of phosphoinositide interaction were identified, some of which have functional roles in RNA splicing and processing and chromatin assembly. The remaining proteins represent potentially other novel nuclear phosphoinositide-effector proteins and as such strengthen our appreciation of phosphoinositide-regulated nuclear functions. DNA topology was exemplar among these: Biochemical assays validated our proteomic data supporting a direct interaction between phosphatidylinositol 4,5-bisphosphate and DNA Topoisomerase IIα. In addition, a subset of neomycin extracted proteins were further validated as phosphatidyl 4,5-bisphosphate-interacting proteins by quantitative lipid pull downs. In summary, data sets such as this serve as a resource for a global view of phosphoinositide-regulated nuclear functions.

  5. Phosphatidylinositol 4,5-bisphosphate formation in rabbit skeletal and heart muscle membranes.

    Science.gov (United States)

    Varsányi, M; Messer, M; Brandt, N R; Heilmeyer, L M

    1986-08-14

    Incubation of rabbit skeletal muscle microsomes or isolated triads with gamma 32P-ATP/Mg2+ in the absence and in the presence of added phosphatidylinositol resulted in the formation of phosphatidylinositol 4-phosphate catalyzed by phosphatidylinositol kinase. When phosphatidylinositol 4-phosphate was added as exogenous substrate, phosphatidylinositol 4,5-bisphosphate was also formed demonstrating the presence of a membrane bound phosphatidylinositol 4-phosphate kinase. Triads were broken mechanically in a French press and separated on a continuous sucrose gradient. Incubation of these fractions with gamma 32P-ATP/Mg2+ resulted in a rapid labeling of phospholipid in a membrane fraction banding between transverse tubules and the terminal cisternae. Partial triad breakage and triad reformation experiments indicated that this phosphatidylinositol kinase was associated with T-tubules. When exogenous phosphatidylinositol 4-phosphate was employed as substrate phosphatidylinositol 4,5-bisphosphate and phosphatidic acid were formed, indicating the presence of all the enzymes of the polyphosphoinositide signaling system in this special membrane fraction. In contrast, heart muscle microsomes or plasma membranes can catalyze this reaction sequence from endogenous formed phosphatidylinositol 4-phosphate.

  6. Crystal Structure of the alpha6beta6 Holoenzyme of propionyl-coenzyme A Carboxylase

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.; Sadre-Bazzaz, K; Shen, Y; Deng, B; Zhou, Z; Tong, L

    2010-01-01

    Propionyl-coenzyme A carboxylase (PCC), a mitochondrial biotin-dependent enzyme, is essential for the catabolism of the amino acids Thr, Val, Ile and Met, cholesterol and fatty acids with an odd number of carbon atoms. Deficiencies in PCC activity in humans are linked to the disease propionic acidaemia, an autosomal recessive disorder that can be fatal in infants. The holoenzyme of PCC is an {alpha}{sub 6}{beta}{sub 6} dodecamer, with a molecular mass of 750 kDa. The {alpha}-subunit contains the biotin carboxylase (BC) and biotin carboxyl carrier protein (BCCP) domains, whereas the {beta}-subunit supplies the carboxyltransferase (CT) activity. Here we report the crystal structure at 3.2-{angstrom} resolution of a bacterial PCC {alpha}{sub 6}{beta}{sub 6} holoenzyme as well as cryo-electron microscopy (cryo-EM) reconstruction at 15-{angstrom} resolution demonstrating a similar structure for human PCC. The structure defines the overall architecture of PCC and reveals unexpectedly that the {alpha}-subunits are arranged as monomers in the holoenzyme, decorating a central {beta}{sub 6} hexamer. A hitherto unrecognized domain in the {alpha}-subunit, formed by residues between the BC and BCCP domains, is crucial for interactions with the {beta}-subunit. We have named it the BT domain. The structure reveals for the first time the relative positions of the BC and CT active sites in the holoenzyme. They are separated by approximately 55 {angstrom}, indicating that the entire BCCP domain must translocate during catalysis. The BCCP domain is located in the active site of the {beta}-subunit in the current structure, providing insight for its involvement in the CT reaction. The structural information establishes a molecular basis for understanding the large collection of disease-causing mutations in PCC and is relevant for the holoenzymes of other biotin-dependent carboxylases, including 3-methylcrotonyl-CoA carboxylase (MCC) and eukaryotic acetyl-CoA carboxylase (ACC).

  7. Phosphatidylinositol 3,5-bisphosphate: regulation of cellular events in space and time.

    Science.gov (United States)

    Jin, Natsuko; Lang, Michael J; Weisman, Lois S

    2016-02-01

    Phosphorylated phosphatidylinositol lipids are crucial for most eukaryotes and have diverse cellular functions. The low-abundance signalling lipid phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] is critical for cellular homoeostasis and adaptation to stimuli. A large complex of proteins that includes the lipid kinase Fab1-PIKfyve, dynamically regulates the levels of PI(3,5)P2. Deficiencies in PI(3,5)P2 are linked to some human diseases, especially those of the nervous system. Future studies will probably determine new, undiscovered regulatory roles of PI(3,5)P2, as well as uncover mechanistic insights into how PI(3,5)P2 contributes to normal human physiology.

  8. Vitamin K-dependent carboxylase: possible role of the substrate "propeptide" as an intracellular recognition site.

    Science.gov (United States)

    Suttie, J W; Hoskins, J A; Engelke, J; Hopfgartner, A; Ehrlich, H; Bang, N U; Belagaje, R M; Schoner, B; Long, G L

    1987-01-01

    The liver microsomal vitamin K-dependent carboxylase catalyzes the posttranslational conversion of specific glutamate residues to gamma-carboxyglutamate residues in a limited number of proteins. A number of these proteins have been shown to contain a homologous basic amino acid-rich "propeptide" between the leader sequence and the amino terminus of the mature protein. Plasmids encoding protein C, a vitamin K-dependent protein, containing or lacking a propeptide region were constructed and the protein was expressed in Escherichia coli. The protein products were assayed as substrates in an in vitro vitamin K-dependent carboxylase system. Only proteins containing a propeptide region were substrates for the enzyme. These data support the hypothesis that this sequence of the primary gene product is an important recognition site for this processing enzyme. PMID:3543932

  9. Reaction of phosphoenolpyruvate carboxylase with (Z)-3-bromophosphoenolpyruvate and (Z)-3-fluorophosphoenolpyruvate

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, E.; O' Laughlin, J.T.; O' Leary, M.H.

    1988-02-23

    (Z)-3-Bromophosphoenolpyruvate inactivates phosphoenolpyruvate carboxylase from maize in the presence of HCO/sub 3//sup -/ and either Mg/sup 2 +/ or Mn/sup 2 +/. The inactivation rate follows saturation kinetics. Inactivation is slower in the presence of phospholactate or epoxymaleate, both of which are inhibitors of the enzyme, or dithiothreitol. Inactivation is completely prevented by the presence of lactate dehydrogenase and NADH, and 3-bromolactate is formed during this treatment. If the reaction is conducted by using HC/sup 18/O/sub 3//sup -/, the inorganic phosphate produced contains /sup 18/O. This and other evidence indicate that phosphoenolpyruvate carboxylase catalyzes conversion of bromophosphoenolpyruvate into bromopyruvate by way of the usual carboxyphosphate-enolate intermediate, and bromopyruvate is the species responsible for enzyme inactivation. (Z)-3-fluorophosphoenolpyruvate is transformed by the enzyme into a 6:1 mixture of 3-fluoropyruvate and 3-fluorooxalacetate, presumably by the same mechanism. The enzyme is not inactivated during this treatment.

  10. Inhibition of acetyl-CoA carboxylase by cystamine may mediate the hypotriglyceridemic activity of pantethine.

    Science.gov (United States)

    McCarty, M F

    2001-03-01

    Pantethine is a versatile and well-tolerated hypolipidemic agent whose efficacy in this regard appears to be mediated by its catabolic product cystamine, a nucleophile which avidly attacks disulfide groups. An overview of pantethine research suggests that the hypotriglyceridemic activity of pantethine reflects cystamine-mediated inhibition of the hepatic acetyl-CoA carboxylase, which can be expected to activate hepatic fatty acid oxidation. Inhibition of HMG-CoA reductase as well as a more distal enzyme in the cholesterol synthetic pathway may account for pantethine's hypocholesterolemic effects. If pantethine does indeed effectively inhibit hepatic acetyl-CoA carboxylase, it may have adjuvant utility in the hepatothermic therapy of obesity. As a safe and effective compound of natural origin, pantethine merits broader use in the management of hyperlipidemias. PMID:11359352

  11. Regulation and structure of the heteromeric acetyl-CoA carboxylase.

    Science.gov (United States)

    Salie, Matthew J; Thelen, Jay J

    2016-09-01

    The enzyme acetyl-CoA carboxylase (ACCase) catalyzes the committed step of the de novo fatty acid biosynthesis (FAS) pathway by converting acetyl-CoA to malonyl-CoA. Two forms of ACCase exist in nature, a homomeric and heteromic form. The heteromeric form of this enzyme requires four different subunits for activity: biotin carboxylase; biotin carboxyl carrier protein; and α- and β-carboxyltransferases. Heteromeric ACCases (htACCase) can be found in prokaryotes and the plastids of most plants. The plant htACCase is regulated by diverse mechanisms reflected by the biochemical and genetic complexity of this multienzyme complex and the plastid stroma where it resides. In this review we summarize the regulation of the plant htACCase and also describe the structural characteristics of this complex from both prokaryotes and plants. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27091637

  12. Expression, purification and crystallization of an archaeal-type phosphoenolpyruvate carboxylase

    International Nuclear Information System (INIS)

    The expression, purification, crystallization and preliminary diffraction analysis of an archaeal-type phosphoenolpyruvate carboxylase are described. Complete highly redundant X-ray data have been measured from a crystal diffracting to 3.13 Å resolution. An archaeal-type phosphoenolpyruvate carboxylase (PepcA) from Clostridium perfringens has been expressed in Escherichia coli in a soluble form with an amino-terminal His tag. The recombinant protein is enzymatically active and two crystal forms have been obtained. Complete diffraction data extending to 3.13 Å resolution have been measured from a crystal soaked in KAu(CN)2, using radiation at a wavelength just above the Au LIII edge. The asymmetric unit contains two tetramers of PepcA

  13. Crystal structure of the 500-kDa yeast acetyl-CoA carboxylase holoenzyme dimer.

    Science.gov (United States)

    Wei, Jia; Tong, Liang

    2015-10-29

    Acetyl-CoA carboxylase (ACC) has crucial roles in fatty acid metabolism and is an attractive target for drug discovery against diabetes, cancer and other diseases. Saccharomyces cerevisiae ACC (ScACC) is crucial for the production of very-long-chain fatty acids and the maintenance of the nuclear envelope. ACC contains biotin carboxylase (BC) and carboxyltransferase (CT) activities, and its biotin is linked covalently to the biotin carboxyl carrier protein (BCCP). Most eukaryotic ACCs are 250-kilodalton (kDa), multi-domain enzymes and function as homodimers and higher oligomers. They contain a unique, 80-kDa central region that shares no homology with other proteins. Although the structures of the BC, CT and BCCP domains and other biotin-dependent carboxylase holoenzymes are known, there is currently no structural information on the ACC holoenzyme. Here we report the crystal structure of the full-length, 500-kDa holoenzyme dimer of ScACC. The structure is remarkably different from that of the other biotin-dependent carboxylases. The central region contains five domains and is important for positioning the BC and CT domains for catalysis. The structure unexpectedly reveals a dimer of the BC domain and extensive conformational differences compared to the structure of the BC domain alone, which is a monomer. These structural changes reveal why the BC domain alone is catalytically inactive and define the molecular mechanism for the inhibition of eukaryotic ACC by the natural product soraphen A and by phosphorylation of a Ser residue just before the BC domain core in mammalian ACC. The BC and CT active sites are separated by 80 Å, and the entire BCCP domain must translocate during catalysis. PMID:26458104

  14. Vitamin K-dependent carboxylase: possible role of the substrate "propeptide" as an intracellular recognition site.

    OpenAIRE

    Suttie, J W; Hoskins, J A; Engelke, J; Hopfgartner, A; Ehrlich, H.; Bang, N U; Belagaje, R M; Schoner, B; Long, G L

    1987-01-01

    The liver microsomal vitamin K-dependent carboxylase catalyzes the posttranslational conversion of specific glutamate residues to gamma-carboxyglutamate residues in a limited number of proteins. A number of these proteins have been shown to contain a homologous basic amino acid-rich "propeptide" between the leader sequence and the amino terminus of the mature protein. Plasmids encoding protein C, a vitamin K-dependent protein, containing or lacking a propeptide region were constructed and the...

  15. (4-Piperidinyl)-piperazine: a new platform for acetyl-CoA carboxylase inhibitors.

    Science.gov (United States)

    Chonan, Tomomichi; Oi, Takahiro; Yamamoto, Daisuke; Yashiro, Miyoko; Wakasugi, Daisuke; Tanaka, Hiroaki; Ohoka-Sugita, Ayumi; Io, Fusayo; Koretsune, Hiroko; Hiratate, Akira

    2009-12-01

    Acetyl-CoA carboxylases (ACCs), the rate limiting enzymes in de novo lipid synthesis, play important roles in modulating energy metabolism. The inhibition of ACC has demonstrated promising therapeutic potential for treating obesity and type 2 diabetes mellitus in transgenic mice and preclinical animal models. We describe herein the synthesis and structure-activity relationships of a series of disubstituted (4-piperidinyl)-piperazine derivatives as a new platform for ACC1/2 non-selective inhibitors.

  16. Solar ultraviolet radiation affects the activity of ribulose-1, 5-bisphosphate carboxylase-oxygenase and the composition of photosynthetic and xanthophyll cycle pigments in the intertidal green alga Ulva lactuca L.

    NARCIS (Netherlands)

    Bischof, K; Krabs, G; Wiencke, C; Hanelt, D

    2002-01-01

    The effect of solar UV radiation on the physiology of the intertidal green macroalga Ulva lactuca L. was investigated. A natural Ulm community at the shore of Helgoland was covered with screening foils, excluding UV-B or UV-B + UV-A from the solar spectrum. In the sampled material, changes in the ac

  17. Identification of arginine 331 as an important active site residue in the class II fructose-1,6-bisphosphate aldolase of Escherichia coli.

    OpenAIRE

    S Qamar; Marsh, K; Berry, A

    1996-01-01

    Treatment of the Class II fructose-1,6-bisphosphate aldolase of Escherichia coli with the arginine-specific alpha-dicarbonyl reagents, butanedione or phenylglyoxal, results in inactivation of the enzyme. The enzyme is protected from inactivation by the substrate, fructose 1,6-bisphosphate, or by inorganic phosphate. Modification with [7-14C] phenylglyoxal in the absence of substrate demonstrates that enzyme activity is abolished by the incorporation of approximately 2 moles of reagent per mol...

  18. Phosphatidylinositol 4,5-bisphosphate alters pharmacological selectivity for epilepsy-causing KCNQ potassium channels

    Science.gov (United States)

    Zhou, Pingzheng; Yu, Haibo; Gu, Min; Nan, Fa-jun; Gao, Zhaobing; Li, Min

    2013-01-01

    Pharmacological augmentation of neuronal KCNQ muscarinic (M) currents by drugs such as retigabine (RTG) represents a first-in-class therapeutic to treat certain hyperexcitatory diseases by dampening neuronal firing. Whereas all five potassium channel subtypes (KCNQ1–KCNQ5) are found in the nervous system, KCNQ2 and KCNQ3 are the primary players that mediate M currents. We investigated the plasticity of subtype selectivity by two M current effective drugs, retigabine and zinc pyrithione (ZnPy). Retigabine is more effective on KCNQ3 than KCNQ2, whereas ZnPy is more effective on KCNQ2 with no detectable effect on KCNQ3. In neurons, activation of muscarinic receptor signaling desensitizes effects by retigabine but not ZnPy. Importantly, reduction of phosphatidylinositol 4,5-bisphosphate (PIP2) causes KCNQ3 to become sensitive to ZnPy but lose sensitivity to retigabine. The dynamic shift of pharmacological selectivity caused by PIP2 may be induced orthogonally by voltage-sensitive phosphatase, or conversely, abolished by mutating a PIP2 site within the S4–S5 linker of KCNQ3. Therefore, whereas drug-channel binding is a prerequisite, the drug selectivity on M current is dynamic and may be regulated by receptor signaling pathways via PIP2. PMID:23650395

  19. Novel Phosphotidylinositol 4,5-Bisphosphate Binding Sites on Focal Adhesion Kinase.

    Directory of Open Access Journals (Sweden)

    Jun Feng

    Full Text Available Focal adhesion kinase (FAK is a protein tyrosine kinase that is ubiquitously expressed, recruited to focal adhesions, and engages in a variety of cellular signaling pathways. Diverse cellular responses, such as cell migration, proliferation, and survival, are regulated by FAK. Prior to activation, FAK adopts an autoinhibited conformation in which the FERM domain binds the kinase domain, blocking access to the activation loop and substrate binding site. Activation of FAK occurs through conformational change, and acidic phospholipids such as phosphatidylinositol 4,5-bisphosphate (PIP2 are known to facilitate this process. PIP2 binding alters the autoinhibited conformation of the FERM and kinase domains and subsequently exposes the activation loop to phosphorylation. However, the detailed molecular mechanism of PIP2 binding and its role in FAK activation remain unclear. In this study, we conducted coarse-grained molecular dynamics simulations to investigate the binding of FAK to PIP2. Our simulations identified novel areas of basic residues in the kinase domain of FAK that potentially undergo transient binding to PIP2 through electrostatic attractions. Our investigation provides a molecular picture of PIP2-initiated FAK activation and introduces promising new pathways for future studies of FAK regulation.

  20. Wheat cytosolic acetyl-CoA carboxylase complements an ACC1 null mutation in yeast

    OpenAIRE

    Joachimiak, M.; Tevzadze, G.; Podkowinski, J; Haselkorn, R.; Gornicki, P.

    1997-01-01

    Spores harboring an ACC1 deletion derived from a diploid Saccharomyces cerevisiae strain, in which one copy of the entire ACC1 gene is replaced with a LEU2 cassette, fail to grow. A chimeric gene consisting of the yeast GAL10 promoter, yeast ACC1 leader, wheat cytosolic acetyl-CoA carboxylase (ACCase) cDNA, and yeast ACC1 3′ tail was used to complement a yeast ACC1 mutation. The complementation demonstrates that active wheat ACCase can be produced in yeast. At low concentrations of galactose,...

  1. Attempts to apply affinity labeling techniques to ribulosebisphosphate carboxylase/oxygenase. [Comparison of spinach leaf and Rhodospirillum rubrum

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, F. C.; Norton, I. L.; Stringer, C. D.; Schloss, J. V.

    1978-01-01

    Studies on carboxylases/oxygenases from different species may be necessary to confirm that a residue implicated as essential is indeed an active-site component. To provide an especially stringent test case for the identification of species invariant structural features the enzymes from two phylogenetically distant species, spinach and Rhodospirillum rubrum, were compared. To date, the reactions of Br-butanone-P/sub 2/ and BrAcNHEtOP with the spinach enayme have been rather thoroughly characterized; only preliminary experiments have been completed with the R. rubrum enzyme. Both enzymes were isolated and assayed for carboxylase activity (spectrophotometrically or /sup 14/CO/sub 2/-fixation) and for oxygenase activity.

  2. Increased expression of pyruvate carboxylase and biotin protein ligase increases lysine production in a biotin prototrophic Corynebacterium glutamicum strain

    DEFF Research Database (Denmark)

    Wang, Zhihao; Moslehi-Jenabian, Soloomeh; Solem, Christian;

    2015-01-01

    was cultivated without biotin, indicating a suboptimal intracellular concentration of biotin. In an attempt to locate the potential bottleneck, we added pimelic acid, an early biotin precursor, and found that growth rate could be restored fully, which demonstrates that the bottleneck is in pimeloyl-CoA (or...... pimeloyl-Acyl Carrier Protein [ACP]) formation. Pyruvate carboxylase (pycA), a biotin-dependent enzyme needed for lysine biosynthesis and biotin ligase (birA), which is responsible for attaching biotin to pyruvate carboxylase, were overexpressed by replacing the native promoters with the strong superoxide...

  3. Isolation and characterization of an Arabidopsis biotin carboxylase gene and its promoter.

    Science.gov (United States)

    Bao, X; Shorrosh, B S; Ohlrogge, J B

    1997-11-01

    In the plastids of most plants, acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) is a multisubunit complex consisting of biotin carboxylase (BC), biotin-carboxyl carrier protien (BCCP), and carboxytransferase (alpha-CT, beta-CT) subunits. To better understand the regulation of this enzyme, we have isolated and sequenced a BC genomic clone from Arabidopsis and partially characterized its promoter. Fifteen introns were identified. The deduced amino acid sequence of the mature BC protein is highly conserved between Arabidopsis and tobacco (92.6% identity). BC expression was evaluated using northern blots and BC/GUS fusion constructs in transgenic Arabidopsis. GUS activity in the BC/GUS transgenics as well as transcript level of the native gene were both found to be higher in silique and flower than in root and leaf. Analysis of tobacco suspension cells transformed with truncated BC promoter/GUS gene fusions indicated the region from -140 to +147 contained necessary promoter elements which supported basal gene expression. A positive regulatory region was found to be located between -2100 and -140, whereas a negative element was possibly located in the first intron. In addition, several conserved regulatory elements were identified in the BC promoter. Surprisingly, although BC is a low-abundance protein, the expression of BC/GUS fusion constructs was similar to 35S/GUS constructs.

  4. Biotin deficiency in the cat and the effect on hepatic propionyl CoA carboxylase.

    Science.gov (United States)

    Carey, C J; Morris, J G

    1977-02-01

    Biotin deficiency was produced in growing kittens by feeding a diet containing dried, raw egg white. After receiving either an 18.5% egg white diet for 25 weeks, or a 32% egg white diet for 12 weeks, they exhibited dermal lesions characterized by alopecia, scaly dermatitis and achromotrichia, which increased in severity with the deficiency. Females developed accumulations of dried salivary, nasal and lacrymal secretions in the facial region although a male did not. There was a loss of body weight in all cats as the deficiency progressed. Hepatic propionyl CoA carboxylase activities were measured on biopsy samples of liver during biotin deficiency and after biotin supplementation. In the deficient state, activities were 4% and 24% of that following biotin supplementation. Propionyl carboxylase activity in the liver of the cat was comparable to that reported in the rat and chick in the deficient and normal states. Subcutaneous injection of 0.25 mg biotin every other day while continuing to receive the egg white diet caused remission of clinical signs, a body weight gain and increased food intake.

  5. Fructose 1,6-Bisphosphate Aldolase, a Novel Immunogenic Surface Protein on Listeria Species

    Science.gov (United States)

    Conceição, Fabricio Rochedo; Hust, Michael; Mendonça, Karla Sequeira; Moreira, Ângela Nunes; França, Rodrigo Correa; da Silva, Wladimir Padilha; Aleixo, José Antonio G.

    2016-01-01

    Listeria monocytogenes is a ubiquitous food-borne pathogen, and its presence in food or production facilities highlights the importance of surveillance. Increased understanding of the surface exposed antigens on Listeria would provide potential diagnostic and therapeutic targets. In the present work, using mass spectrometry and genetic cloning, we show that fructose-1,6-bisphosphate aldolase (FBA) class II in Listeria species is the antigen target of the previously described mAb-3F8. Western and dot blot assays confirmed that the mAb-3F8 could distinguish all tested Listeria species from close-related bacteria. Localization studies indicated that FBA is present in every fraction of Listeria cells, including supernatant and the cell wall, setting Listeria spp. as one of the few bacteria described to have this protein on their cell surface. Epitope mapping using ORFeome display and a peptide membrane revealed a 14-amino acid peptide as the potential mAb-3F8 epitope. The target epitope in FBA allowed distinguishing Listeria spp. from closely-related bacteria, and was identified as part of the active site in the dimeric enzyme. However, its function in cell surface seems not to be host cell adhesion-related. Western and dot blot assays further demonstrated that mAb-3F8 together with anti-InlA mAb-2D12 could differentiate pathogenic from non-pathogenic Listeria isolated from artificially contaminated cheese. In summary, we report FBA as a novel immunogenic surface target useful for the detection of Listeria genus. PMID:27489951

  6. Lack of fructose 2,6-bisphosphate compromises photosynthesis and growth in Arabidopsis in fluctuating environments.

    Science.gov (United States)

    McCormick, Alistair J; Kruger, Nicholas J

    2015-03-01

    The balance between carbon assimilation, storage and utilisation during photosynthesis is dependent on partitioning of photoassimilate between starch and sucrose, and varies in response to changes in the environment. However, the extent to which the capacity to modulate carbon partitioning rapidly through short-term allosteric regulation may contribute to plant performance is unknown. Here we examine the physiological role of fructose 2,6-bisphosphate (Fru-2,6-P2 ) during photosynthesis, growth and reproduction in Arabidopsis thaliana (L.). In leaves this signal metabolite contributes to coordination of carbon assimilation and partitioning during photosynthesis by allosterically modulating the activity of cytosolic fructose-1,6-bisphosphatase. Three independent T-DNA insertional mutant lines deficient in 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (F2KP), the bifunctional enzyme responsible for both the synthesis and degradation of Fru-2,6-P2 , lack Fru-2,6-P2 . These plants have normal steady-state rates of photosynthesis, but exhibit increased partitioning of photoassimilate into sucrose and have delayed photosynthetic induction kinetics. The F2KP-deficient plants grow normally in constant environments, but show reduced growth and seed yields relative to wildtype plants in fluctuating light and/or temperature. We conclude that Fru-2,6-P2 is required for optimum regulation of photosynthetic carbon metabolism under variable growth conditions. These analyses suggest that the capacity of Fru-2,6-P2 to modulate partitioning of photoassimilate is an important determinant of growth and fitness in natural environments.

  7. Insights into the carboxyltransferase reaction of pyruvate carboxylase from the structures of bound product and intermediate analogs.

    Science.gov (United States)

    Lietzan, Adam D; St Maurice, Martin

    2013-11-15

    Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP- and bicarbonate-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. The carboxyltransferase (CT) domain of PC catalyzes the transfer of a carboxyl group from carboxybiotin to the accepting substrate, pyruvate. It has been hypothesized that the reactive enolpyruvate intermediate is stabilized through a bidentate interaction with the metal ion in the CT domain active site. Whereas bidentate ligands are commonly observed in enzymes catalyzing reactions proceeding through an enolpyruvate intermediate, no bidentate interaction has yet been observed in the CT domain of PC. Here, we report three X-ray crystal structures of the Rhizobium etli PC CT domain with the bound inhibitors oxalate, 3-hydroxypyruvate, and 3-bromopyruvate. Oxalate, a stereoelectronic mimic of the enolpyruvate intermediate, does not interact directly with the metal ion. Instead, oxalate is buried in a pocket formed by several positively charged amino acid residues and the metal ion. Furthermore, both 3-hydroxypyruvate and 3-bromopyruvate, analogs of the reaction product oxaloacetate, bind in an identical manner to oxalate suggesting that the substrate maintains its orientation in the active site throughout catalysis. Together, these structures indicate that the substrates, products and intermediates in the PC-catalyzed reaction are not oriented in the active site as previously assumed. The absence of a bidentate interaction with the active site metal appears to be a unique mechanistic feature among the small group of biotin-dependent enzymes that act on α-keto acid substrates. PMID:24157795

  8. Evolution and Functional Diversification of Fructose Bisphosphate Aldolase Genes in Photosynthetic Marine Diatoms

    Science.gov (United States)

    Allen, Andrew E.; Moustafa, Ahmed; Montsant, Anton; Eckert, Angelika; Kroth, Peter G.; Bowler, Chris

    2012-01-01

    Diatoms and other chlorophyll-c containing, or chromalveolate, algae are among the most productive and diverse phytoplankton in the ocean. Evolutionarily, chlorophyll-c algae are linked through common, although not necessarily monophyletic, acquisition of plastid endosymbionts of red as well as most likely green algal origin. There is also strong evidence for a relatively high level of lineage-specific bacterial gene acquisition within chromalveolates. Therefore, analyses of gene content and derivation in chromalveolate taxa have indicated particularly diverse origins of their overall gene repertoire. As a single group of functionally related enzymes spanning two distinct gene families, fructose 1,6-bisphosphate aldolases (FBAs) illustrate the influence on core biochemical pathways of specific evolutionary associations among diatoms and other chromalveolates with various plastid-bearing and bacterial endosymbionts. Protein localization and activity, gene expression, and phylogenetic analyses indicate that the pennate diatom Phaeodactylum tricornutum contains five FBA genes with very little overall functional overlap. Three P. tricornutum FBAs, one class I and two class II, are plastid localized, and each appears to have a distinct evolutionary origin as well as function. Class I plastid FBA appears to have been acquired by chromalveolates from a red algal endosymbiont, whereas one copy of class II plastid FBA is likely to have originated from an ancient green algal endosymbiont. The other copy appears to be the result of a chromalveolate-specific gene duplication. Plastid FBA I and chromalveolate-specific class II plastid FBA are localized in the pyrenoid region of the chloroplast where they are associated with β-carbonic anhydrase, which is known to play a significant role in regulation of the diatom carbon concentrating mechanism. The two pyrenoid-associated FBAs are distinguished by contrasting gene expression profiles under nutrient limiting compared with

  9. Resolving the Activation Site of PositiveRegulators in Plant PhosphoenolpyruvateCarboxylase

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Dear Editor, Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) islocated at an important branch point in the carbohydratemetabolism of plants. The enzyme is a homotetramer andcatalyzes the addition of bicarbonate to phosphoenolpyru-vate (PEP) to form oxaloacetate and phosphate. PEPC isregulated by metabolites and phosphorylation. AIIostericfeedback inhibition is mainly regulated by L-malate andL-aspartate which bind to a site separated from the activecenter (Kai et al., 1999; Paulus et al., 2013). Structure analy-sis of PEPC from Escherichia coli (Kai et al., 1999; Matsumuraet al., 2002), Zea rnays (Matsumura et al., 2002), Flaveria trin-ervia, and F. pringlei (Paulus et al., 2013) revealed that thesubstrate PEP and the feedback inhibitors bind to separatesites within each monomer.

  10. Novel Mutations in the PC Gene in Patients with Type B Pyruvate Carboxylase Deficiency

    DEFF Research Database (Denmark)

    Ostergaard, Elsebet; Duno, Morten; Møller, Lisbeth Birk;

    2013-01-01

    We have investigated seven patients with the type B form of pyruvate carboxylase (PC) deficiency. Mutation analysis revealed eight mutations, all novel. In a patient with exon skipping on cDNA analysis, we identified a homozygous mutation located in a potential branch point sequence, the first...... possible branch point mutation in PC. Two patients were homozygous for missense mutations (with normal protein amounts on western blot analysis), and two patients were homozygous for nonsense mutations. In addition, a duplication of one base pair was found in a patient who also harboured a splice site...... mutation. Another splice site mutation led to the activation of a cryptic splice site, shown by cDNA analysis.All patients reported until now with at least one missense mutation have had the milder type A form of PC deficiency. We thus report for the first time two patients with homozygous missense...

  11. AcEST: BP918009 [AcEST

    Lifescience Database Archive (English)

    Full Text Available jct: 164 QVQCISFIAYKP 175 >tr|A7LIT5|A7LIT5_9ROSI Ribulose bisphosphate carboxylase small chain OS=Corchor...us olitorius PE=2 SV=1 Length = 183 Score = 110 bits (275), Expect = 4e-23 Identiti

  12. Insights into the carboxyltransferase reaction of pyruvate carboxylase from the structures of bound product and intermediate analogues

    OpenAIRE

    Lietzan, Adam D.; St. Maurice, Martin

    2013-01-01

    Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP- and bicarbonate-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. The carboxyltransferase (CT) domain of PC catalyzes the transfer of a carboxyl group from carboxybiotin to the accepting substrate, pyruvate. It has been hypothesized that the reactive enolpyruvate intermediate is stabilized through a bidentate interaction with the metal ion in the CT doma...

  13. Active Site Loop Dynamics of a Class IIa Fructose 1,6-Bisphosphate Aldolase from Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Pegan, Scott D. [Univ. of Denver, CO (United States); Rukseree, Kamolchanok [National Center for Genetic Engineering and Biotechnology (BIOTEC), Tha Khlong (Thailand); Capodagli, Glenn C. [Univ. of Denver, CO (United States); Baker, Erica A. [Univ. of Denver, CO (United States); Krasnykh, Olga [Univ. of Illinois, Chicago, IL (United States); Franzblau, Scott G. [Univ. of Illinois, Chicago, IL (United States); Mesecar, Andrew D. [Purdue Univ., West Lafayette, IN (United States)

    2013-01-08

    The class II fructose 1,6-bisphosphate aldolases (FBAs, EC 4.1.2.13) comprises one of two families of aldolases. Instead of forming a Schiff base intermediate using an ε-amino group of a lysine side chain, class II FBAs utilize Zn(II) to stabilize a proposed hydroxyenolate intermediate (HEI) in the reversible cleavage of fructose 1,6-bisphosphate, forming glyceraldehyde 3-phosphate and dihydroxyacetone phosphate (DHAP). As class II FBAs have been shown to be essential in pathogenic bacteria, focus has been placed on these enzymes as potential antibacterial targets. Although structural studies of class II FBAs from Mycobacterium tuberculosis (MtFBA), other bacteria, and protozoa have been reported, the structure of the active site loop responsible for catalyzing the protonation–deprotonation steps of the reaction for class II FBAs has not yet been observed. We therefore utilized the potent class II FBA inhibitor phosphoglycolohydroxamate (PGH) as a mimic of the HEI- and DHAP-bound form of the enzyme and determined the X-ray structure of the MtFBA–PGH complex to 1.58 Å. Remarkably, we are able to observe well-defined electron density for the previously elusive active site loop of MtFBA trapped in a catalytically competent orientation. Utilization of this structural information and site-directed mutagenesis and kinetic studies conducted on a series of residues within the active site loop revealed that E169 facilitates a water-mediated deprotonation–protonation step of the MtFBA reaction mechanism. Furthermore, solvent isotope effects on MtFBA and catalytically relevant mutants were used to probe the effect of loop flexibility on catalytic efficiency. Additionally, we also reveal the structure of MtFBA in its holoenzyme form.

  14. Relationship between NH4+ assimilation rate and in vivo phosphoenolpyruvate carboxylase activity

    International Nuclear Information System (INIS)

    The rate of NH4+ assimilation by N-limited Selenastrum minutum (Naeg.) Collins cells in the dark was set as an independent variable and the relationship between NH4+ assimilation rate and in vivo activity of phosphoenolpyruvate carboxylase (PEPC) was determined. In vivo activity of PEPC was measured by following the incorporation of H14CO3- into acid stable products. A linear relationship of 0.3 moles C fixed via PEPC per mole N assimilated was observed. This value agrees extremely well with the PEPC requirement for the synthesis of the amino acids found in total cellular protein. Determinations of metabolite levels in vivo at different rates of N assimilation indicated that the known metabolite effectors of S. minutum PEPC in vitro (KA Schuller, WC Plaxton, DH Turpin, [1990] Plant Physiol 93: 1303-1311) are important regulators of this enzyme during N assimilation. As PEPC activity increased in response to increasing rates of N assimilation, there was a corresponding decline in the level of PEPC inhibitors (2-oxoglutarate, malate), an increase in the level of PEPC activators (glutamine, dihydroxyacetone phosphate), and an increase in the Gln/Glu ratio. Treatment of N-limited cells with azaserine caused an increase in the Gln/Glu ratio resulting in increased PEPC activity in the absence of N assimilation. We suggest glutamate and glutamine play a key role in regulating the anaplerotic function of PEPC in this C3 organism

  15. Cloning and characterization of cotton heteromeric acetyl-CoA carboxylase genes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Heteromeric acetyl-coanzyme A(CoA)carboxylese(ACCase)catalyzes the formation of malonyl-CoA from acetyl-CoA.It plays an essential role in fatty acid synthesis in prokaryotes and most of plants.The heteromeric ACCase is composed of four subunits:biotin carboxylase (BC),biotin carboxyl carrier protein (BCCP),and α-and β-subunits of carboxyltransferese(α-andβ-CT).In this study,we cloned five novel genes encoding the subunits of heteromeric ACCese(one BC,BCCP and β-CT,and two α-CTs) from cotton (Gossypium hirsutum cv.zhongmian 35)by RACE-PCR.The deduced amino acid sequence of these cDNAs shares high similarity with other reported heteromeric ACCese subunits.The phylogenetic analysis indicated that the different subunits of heteromeric ACCase were grouped in a similar pattern.Southern blot analysis revealed the milti-copy patterns of these heteromeric ACCase genes in cotton genome.Semi-quantitative RT-PCR demonstrated that heteromeric ACCese genes were constitutively expressed in all of the cotton tissues,but the transcripts accumulated at a relatively low level in roots.To our knowledge,this is the first report about characterization of the heteromeric ACCase genes in cotton.

  16. The urea carboxylase and allophanate hydrolase activities of urea amidolyase are functionally independent.

    Science.gov (United States)

    Lin, Yi; Boese, Cody J; St Maurice, Martin

    2016-10-01

    Urea amidolyase (UAL) is a multifunctional biotin-dependent enzyme that contributes to both bacterial and fungal pathogenicity by catalyzing the ATP-dependent cleavage of urea into ammonia and CO2 . UAL is comprised of two enzymatic components: urea carboxylase (UC) and allophanate hydrolase (AH). These enzyme activities are encoded on separate but proximally related genes in prokaryotes while, in most fungi, they are encoded by a single gene that produces a fusion enzyme on a single polypeptide chain. It is unclear whether the UC and AH activities are connected through substrate channeling or other forms of direct communication. Here, we use multiple biochemical approaches to demonstrate that there is no substrate channeling or interdomain/intersubunit communication between UC and AH. Neither stable nor transient interactions can be detected between prokaryotic UC and AH and the catalytic efficiencies of UC and AH are independent of one another. Furthermore, an artificial fusion of UC and AH does not significantly alter the AH enzyme activity or catalytic efficiency. These results support the surprising functional independence of AH from UC in both the prokaryotic and fungal UAL enzymes and serve as an important reminder that the evolution of multifunctional enzymes through gene fusion events does not always correlate with enhanced catalytic function.

  17. Epigenetic regulation of pyruvate carboxylase gene expression in the postpartum liver.

    Science.gov (United States)

    Walker, C G; Crookenden, M A; Henty, K M; Handley, R R; Kuhn-Sherlock, B; White, H M; Donkin, S S; Snell, R G; Meier, S; Heiser, A; Loor, J J; Mitchell, M D; Roche, J R

    2016-07-01

    Hepatic gluconeogenesis is essential for maintenance of whole body glucose homeostasis and glucose supply for mammary lactose synthesis in the dairy cow. Upregulation of the gluconeogenic enzyme pyruvate carboxylase (PC) during the transition period is vital in the adaptation to the greater glucose demands associated with peripartum lactogenesis. The objective of this study was to determine if PC transcription in hepatocytes is regulated by DNA methylation and if treatment with a nonsteroidal anti-inflammatory drug (NSAID) alters methylation of an upstream DNA sequence defined as promoter 1. Dairy cows were left untreated (n=20), or treated with a NSAID during the first 5 d postcalving (n=20). Liver was biopsied at d 7 precalving and d 7, 14, and 28 postcalving. Total PC and transcript specific gene expression was quantified using quantitative PCR and DNA methylation of promoter 1 was quantified using bisulfite Sanger sequencing. Expression of PC changed over the transition period, with increased expression postcalving occurring concurrently with increased circulating concentration of nonesterified fatty acids. The DNA methylation percentage was variable at all sites quantified and ranged from 21 to 54% across the 15 CpG dinucleotides within promoter 1. The DNA methylation at wk 1 postcalving, however, was not correlated with gene expression of promoter 1-regulated transcripts and we did not detect an effect of NSAID treatment on DNA methylation or PC gene expression. Our results do not support a role for DNA methylation in regulating promoter 1-driven gene expression of PC at wk 1 postcalving. Further research is required to determine the mechanisms regulating increased PC expression over the transition period. PMID:27085418

  18. Core promoter acetylation is not required for high transcription from the phosphoenolpyruvate carboxylase promoter in maize

    Directory of Open Access Journals (Sweden)

    Horst Ina

    2009-12-01

    Full Text Available Abstract Background Acetylation of promoter nucleosomes is tightly correlated and mechanistically linked to gene activity. However, transcription is not necessary for promoter acetylation. It seems, therefore, that external and endogenous stimuli control histone acetylation and by this contribute to gene regulation. Photosynthetic genes in plants are excellent models with which to study the connection between stimuli and chromatin modifications because these genes are strongly expressed and regulated by multiple stimuli that are easily manipulated. We have previously shown that acetylation of specific histone lysine residues on the photosynthetic phosphoenolpyruvate carboxylase (Pepc promoter in maize is controlled by light and is independent of other stimuli or gene activity. Acetylation of upstream promoter regions responds to a set of other stimuli which include the nutrient availability of the plant. Here, we have extended these studies by analysing histone acetylation during the diurnal and circadian rhythm of the plant. Results We show that histone acetylation of individual lysine residues is removed from the core promoter before the end of the illumination period which is an indication that light is not the only factor influencing core promoter acetylation. Deacetylation is accompanied by a decrease in gene activity. Pharmacological inhibition of histone deacetylation is not sufficient to prevent transcriptional repression, indicating that deacetylation is not controlling diurnal gene regulation. Variation of the Pepc promoter activity during the day is controlled by the circadian oscillator as it is maintained under constant illumination for at least 3 days. During this period, light-induced changes in histone acetylation are completely removed from the core promoter, although the light stimulus is continuously applied. However, acetylation of most sites on upstream promoter elements follows the circadian rhythm. Conclusion Our results

  19. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Science.gov (United States)

    Peng, Yingmei; Cai, Jing; Wang, Wen; Su, Bing

    2012-01-01

    Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC) while the other as bacteria-type pepcase (BTPC) because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT) from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought. PMID:23251445

  20. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Directory of Open Access Journals (Sweden)

    Yingmei Peng

    Full Text Available Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC while the other as bacteria-type pepcase (BTPC because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought.

  1. Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    Full Text Available Pyruvate carboxylase (PC is an enzyme that plays a crucial role in many biosynthetic pathways in various tissues including glucose-stimulated insulin secretion. In the present study, we identify promoter usage of the human PC gene in pancreatic beta cells. The data show that in the human, two alternative promoters, proximal and distal, are responsible for the production of multiple mRNA isoforms as in the rat and mouse. RT-PCR analysis performed with cDNA prepared from human liver and islets showed that the distal promoter, but not the proximal promoter, of the human PC gene is active in pancreatic beta cells. A 1108 bp fragment of the human PC distal promoter was cloned and analyzed. It contains no TATA box but possesses two CCAAT boxes, and other putative transcription factor binding sites, similar to those of the distal promoter of rat PC gene. To localize the positive regulatory region in the human PC distal promoter, 5'-truncated and the 25-bp and 15-bp internal deletion mutants of the human PC distal promoter were generated and used in transient transfections in INS-1 832/13 insulinoma and HEK293T (kidney cell lines. The results indicated that positions -340 to -315 of the human PC distal promoter serve as (an activator element(s for cell-specific transcription factor, while the CCAAT box at -71/-67, a binding site for nuclear factor Y (NF-Y, as well as a GC box at -54/-39 of the human PC distal promoter act as activator sequences for basal transcription.

  2. Photosynthetic Characteristics and Heterosis in Transgenic Hybrid Rice with Maize Phosphoenolpyruvate Carboxylase (pepc) Gene

    Institute of Scientific and Technical Information of China (English)

    LI Ji-hang; XIANG Xun-chao; ZHOU Hua-qiang; HE Li-bin; ZHANG Kai-zheng; LI Ping

    2006-01-01

    Three F1 hybrids derived from the sterile rice lines Gang 46A, 776A and 2480A and the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase (pepc) gene were used to analyze the effect of pepc gene on the heterosis and photosynthetic characteristics, while the F1 obtained by crossing Shuhui 881 with the above three sterile lines served as controls. The dynamics of photosynthetic characteristics in leaves of three F1 with pepc gene and their controls were determined at the initial-tillering, maxium-tillering, elongation, initial-heading, heading, maturity stages, and other different times after flag leaf fully expanded. The PEPCase activities of the three F1 with pepc gene increased significantly as compared with control plants during the whole developmental stages. Moreover, the net photosynthesis rate (Pn) also increased to certain extent. The data showed that PEPCase activity was significantly correlated to Pn with a correlation coefficient of 0.6081**. The photosynthetic indexes of the three F1 with pepc gene were obviously superior with respective to controls in apparent quantum yield, light compensation point (LCP) and carboxylation efficiency (CE), while the CO2 compensation point (CCP) was lower than that of corresponding control. The Pn of the three F1 with pepc gene at light saturation point (LSP) and CO2 saturation point (CSP) was also higher than that of control plants. In addition, the three F1 with pepc gene had an average increase of 37.10% in grain yields per plant in comparison with control plants. The results indicated that the photosynthetic characteristics of hybrid rice containing pepc gene had been improved to some extent due to the introduction of pepc gene.

  3. Ion-exchange chromatography separates activities synthesizing and degrading fructose 2,6-bisphosphate from C3 and C4 leaves but not from rat liver

    Science.gov (United States)

    Macdonald, F. D.; Chou, Q.; Buchanan, B. B.

    1987-01-01

    Fructose-6-phosphate,2-kinase and fructose-2,6-bisphosphatase were separated on the basis of charge from leaves of C3 (spinach, lettuce, and pea) and C4 (sorghum and amaranthus) plants but not from rat liver--a tissue known to contain a bifunctional enzyme with both activities. [2-32P]Fructose 2,6-bisphosphate binding experiments also suggest that the major forms of these activities reside on different proteins in leaves.

  4. A preliminary X-ray study of d,d-heptose-1,7-bisphosphate phosphatase from Burkholderia thailandensis E264

    International Nuclear Information System (INIS)

    In this study, d,d-heptose-1,7-bisphosphate phosphatase has been cloned, expressed, purified and crystallized. d,d-Heptose-1,7-bisphosphate phosphatase (GmhB), which is involved in the third step of the NDP-heptose biosynthesis pathway, converts d,d-heptose-1,7-bisphosphate to d,d-heptose-1-phosphate. This biosynthesis pathway is a target for new antibiotics or antibiotic adjuvants for Gram-negative pathogens. Burkholderia thailandensis is a useful surrogate organism for studying the pathogenicity of melioidosis owing to its extensive genomic similarity to B. pseudomallei. Melioidosis caused by B. pseudomallei is a serious invasive disease of animals and humans in tropical and subtropical areas. In this study, GmhB has been cloned, expressed, purified and crystallized. X-ray data have also been collected to 2.50 Å resolution using synchrotron radiation. The crystal belonged to space group P6, with unit-cell parameters a = 243.2, b = 243.2, c = 41.1 Å

  5. Design and synthesis of disubstituted (4-piperidinyl)-piperazine derivatives as potent acetyl-CoA carboxylase inhibitors.

    Science.gov (United States)

    Chonan, Tomomichi; Tanaka, Hiroaki; Yamamoto, Daisuke; Yashiro, Miyoko; Oi, Takahiro; Wakasugi, Daisuke; Ohoka-Sugita, Ayumi; Io, Fusayo; Koretsune, Hiroko; Hiratate, Akira

    2010-07-01

    Acetyl-CoA carboxylases (ACCs), the rate limiting enzymes in de novo lipid synthesis, play important roles in modulating energy metabolism. The inhibition of ACC has demonstrated promising therapeutic potential for treating obesity and type 2 diabetes mellitus in transgenic mice and preclinical animal models. We describe herein the structure-based design and synthesis of a novel series of disubstituted (4-piperidinyl)-piperazine derivatives as ACC inhibitors. Our structure-based approach led to the discovery of the indole derivatives 13i and 13j, which exhibited potent in vitro ACC inhibitory activity.

  6. Rapid structural changes and acidification of guard cell vacuoles during stomatal closure require phosphatidylinositol 3,5-bisphosphate.

    Science.gov (United States)

    Bak, Gwangbae; Lee, Eun-Jung; Lee, Yuree; Kato, Mariko; Segami, Shoji; Sze, Heven; Maeshima, Masayoshi; Hwang, Jae-Ung; Lee, Youngsook

    2013-06-01

    Rapid stomatal closure is essential for water conservation in plants and is thus critical for survival under water deficiency. To close stomata rapidly, guard cells reduce their volume by converting a large central vacuole into a highly convoluted structure. However, the molecular mechanisms underlying this change are poorly understood. In this study, we used pH-indicator dyes to demonstrate that vacuolar convolution is accompanied by acidification of the vacuole in fava bean (Vicia faba) guard cells during abscisic acid (ABA)-induced stomatal closure. Vacuolar acidification is necessary for the rapid stomatal closure induced by ABA, since a double mutant of the vacuolar H(+)-ATPase vha-a2 vha-a3 and vacuolar H(+)-PPase mutant vhp1 showed delayed stomatal closure. Furthermore, we provide evidence for the critical role of phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] in changes in pH and morphology of the vacuole. Single and double Arabidopsis thaliana null mutants of phosphatidylinositol 3-phosphate 5-kinases (PI3P5Ks) exhibited slow stomatal closure upon ABA treatment compared with the wild type. Moreover, an inhibitor of PI3P5K reduced vacuolar acidification and convolution and delayed stomatal closure in response to ABA. Taken together, these results suggest that rapid ABA-induced stomatal closure requires PtdIns(3,5)P2, which is essential for vacuolar acidification and convolution. PMID:23757398

  7. A neurotoxic glycerophosphocholine impacts PtdIns-4, 5-bisphosphate and TORC2 signaling by altering ceramide biosynthesis in yeast.

    Science.gov (United States)

    Kennedy, Michael A; Gable, Kenneth; Niewola-Staszkowska, Karolina; Abreu, Susana; Johnston, Anne; Harris, Linda J; Reggiori, Fulvio; Loewith, Robbie; Dunn, Teresa; Bennett, Steffany A L; Baetz, Kristin

    2014-01-01

    Unbiased lipidomic approaches have identified impairments in glycerophosphocholine second messenger metabolism in patients with Alzheimer's disease. Specifically, we have shown that amyloid-β42 signals the intraneuronal accumulation of PC(O-16:0/2:0) which is associated with neurotoxicity. Similar to neuronal cells, intracellular accumulation of PC(O-16:0/2:0) is also toxic to Saccharomyces cerevisiae, making yeast an excellent model to decipher the pathological effects of this lipid. We previously reported that phospholipase D, a phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2)-binding protein, was relocalized in response to PC(O-16:0/2:0), suggesting that this neurotoxic lipid may remodel lipid signaling networks. Here we show that PC(O-16:0/2:0) regulates the distribution of the PtdIns(4)P 5-kinase Mss4 and its product PtdIns(4,5)P2 leading to the formation of invaginations at the plasma membrane (PM). We further demonstrate that the effects of PC(O-16:0/2:0) on the distribution of PM PtdIns(4,5)P2 pools are in part mediated by changes in the biosynthesis of long chain bases (LCBs) and ceramides. A combination of genetic, biochemical and cell imaging approaches revealed that PC(O-16:0/2:0) is also a potent inhibitor of signaling through the Target of rampamycin complex 2 (TORC2). Together, these data provide mechanistic insight into how specific disruptions in phosphocholine second messenger metabolism associated with Alzheimer's disease may trigger larger network-wide disruptions in ceramide and phosphoinositide second messenger biosynthesis and signaling which have been previously implicated in disease progression.

  8. A neurotoxic glycerophosphocholine impacts PtdIns-4, 5-bisphosphate and TORC2 signaling by altering ceramide biosynthesis in yeast.

    Directory of Open Access Journals (Sweden)

    Michael A Kennedy

    2014-01-01

    Full Text Available Unbiased lipidomic approaches have identified impairments in glycerophosphocholine second messenger metabolism in patients with Alzheimer's disease. Specifically, we have shown that amyloid-β42 signals the intraneuronal accumulation of PC(O-16:0/2:0 which is associated with neurotoxicity. Similar to neuronal cells, intracellular accumulation of PC(O-16:0/2:0 is also toxic to Saccharomyces cerevisiae, making yeast an excellent model to decipher the pathological effects of this lipid. We previously reported that phospholipase D, a phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5P2-binding protein, was relocalized in response to PC(O-16:0/2:0, suggesting that this neurotoxic lipid may remodel lipid signaling networks. Here we show that PC(O-16:0/2:0 regulates the distribution of the PtdIns(4P 5-kinase Mss4 and its product PtdIns(4,5P2 leading to the formation of invaginations at the plasma membrane (PM. We further demonstrate that the effects of PC(O-16:0/2:0 on the distribution of PM PtdIns(4,5P2 pools are in part mediated by changes in the biosynthesis of long chain bases (LCBs and ceramides. A combination of genetic, biochemical and cell imaging approaches revealed that PC(O-16:0/2:0 is also a potent inhibitor of signaling through the Target of rampamycin complex 2 (TORC2. Together, these data provide mechanistic insight into how specific disruptions in phosphocholine second messenger metabolism associated with Alzheimer's disease may trigger larger network-wide disruptions in ceramide and phosphoinositide second messenger biosynthesis and signaling which have been previously implicated in disease progression.

  9. Fructose-bisphosphate aldolase and enolase from Echinococcus granulosus: genes, expression patterns and protein interactions of two potential moonlighting proteins.

    Science.gov (United States)

    Lorenzatto, Karina Rodrigues; Monteiro, Karina Mariante; Paredes, Rodolfo; Paludo, Gabriela Prado; da Fonsêca, Marbella Maria; Galanti, Norbel; Zaha, Arnaldo; Ferreira, Henrique Bunselmeyer

    2012-09-10

    Glycolytic enzymes, such as fructose-bisphosphate aldolase (FBA) and enolase, have been described as complex multifunctional proteins that may perform non-glycolytic moonlighting functions, but little is known about such functions, especially in parasites. We have carried out in silico genomic searches in order to identify FBA and enolase coding sequences in Echinococcus granulosus, the causative agent of cystic hydatid disease. Four FBA genes and 3 enolase genes were found, and their sequences and exon-intron structures were characterized and compared to those of their orthologs in Echinococcus multilocularis, the causative agent of alveolar hydatid disease. To gather evidence of possible non-glycolytic functions, the expression profile of FBA and enolase isoforms detected in the E. granulosus pathogenic larval form (hydatid cyst) (EgFBA1 and EgEno1) was assessed. Using specific antibodies, EgFBA1 and EgEno1 were detected in protoscolex and germinal layer cells, as expected, but they were also found in the hydatid fluid, which contains parasite's excretory-secretory (ES) products. Besides, both proteins were found in protoscolex tegument and in vitro ES products, further suggesting possible non-glycolytic functions in the host-parasite interface. EgFBA1 modeled 3D structure predicted a F-actin binding site, and the ability of EgFBA1 to bind actin was confirmed experimentally, which was taken as an additional evidence of FBA multifunctionality in E. granulosus. Overall, our results represent the first experimental evidences of alternative functions performed by glycolytic enzymes in E. granulosus and provide relevant information for the understanding of their roles in host-parasite interplay.

  10. Inactive enzymatic mutant proteins (phosphoglycerate mutase and enolase as sugar binders for ribulose-1,5-bisphosphate regeneration reactors

    Directory of Open Access Journals (Sweden)

    Giri Ashok

    2005-02-01

    Full Text Available Abstract Background Carbon dioxide fixation bioprocess in reactors necessitates recycling of D-ribulose1,5-bisphosphate (RuBP for continuous operation. A radically new close loop of RuBP regenerating reactor design has been proposed that will harbor enzyme-complexes instead of purified enzymes. These reactors will need binders enabling selective capture and release of sugar and intermediate metabolites enabling specific conversions during regeneration. In the current manuscript we describe properties of proteins that will act as potential binders in RuBP regeneration reactors. Results We demonstrate specific binding of 3-phosphoglycerate (3PGA and 3-phosphoglyceraldehyde (3PGAL from sugar mixtures by inactive mutant of yeast enzymes phosphoglycerate mutase and enolase. The reversibility in binding with respect to pH and EDTA has also been shown. No chemical conversion of incubated sugars or sugar intermediate metabolites were found by the inactive enzymatic proteins. The dissociation constants for sugar metabolites are in the micromolar range, both proteins showed lower dissociation constant (Kd for 3-phosphoglycerate (655–796 μM compared to 3-phosphoglyceraldehyde (822–966 μM indicating higher affinity for 3PGA. The proteins did not show binding to glucose, sucrose or fructose within the sensitivity limits of detection. Phosphoglycerate mutase showed slightly lower stability on repeated use than enolase mutants. Conclusions The sugar and their intermediate metabolite binders may have a useful role in RuBP regeneration reactors. The reversibility of binding with respect to changes in physicochemical factors and stability when subjected to repeated changes in these conditions are expected to make the mutant proteins candidates for in-situ removal of sugar intermediate metabolites for forward driving of specific reactions in enzyme-complex reactors.

  11. Soraphen, an inhibitor of the acetyl-CoA carboxylase system, improves peripheral insulin sensitivity in mice fed a high-fat diet

    NARCIS (Netherlands)

    Schreurs, M.; van Dijk, T. H.; Gerding, A.; Havinga, R.; Reijngoud, D. -J.; Kuipers, F.

    2009-01-01

    Aim Inhibition of the acetyl-CoA carboxylase (ACC) system, consisting of the isozymes ACC1 and ACC2, may be beneficial for treatment of insulin resistance and/or obesity by interfering with de novo lipogenesis and beta-oxidation. We have evaluated effects of pharmacological inhibition of ACC by sora

  12. Phosphorylation-dephosphorylation process as a probable mechanism for the diurnal regulatory changes of phosphoenolpyruvate carboxylase in CAM plants.

    Science.gov (United States)

    Brulfert, J; Vidal, J; Le Marechal, P; Gadal, P; Queiroz, O; Kluge, M; Kruger, I

    1986-04-14

    Day and night forms of phosphoenolpyruvate carboxylase (EC 4.1.1.31) (PEPC) were extracted from leaves of the CAM plants Kalanchoe daigremontiana, K. tubiflora and K. blossfeldiana previously fed with [32P] labelled phosphate solution. A one-step immunochemical purification followed by SDS polyacrylamide gel electrophoresis and autoradiography showed that, in all species, the night form of the enzyme was phosphorylated and not the day form. Limited acid hydrolysis of the night form and two-dimensional separation identified predominantly labelled phosphoserine and phosphothreonine. In vitro addition of exogenous acid phosphatase (EC 3.1.3.2) to desalted night form-containing extracts resulted within 30 min in a shift in PEPC enzymic properties similar to the in vivo changes from night to day form. It is suggested that phosphorylation-dephosphorylation of the enzyme could be the primary in vivo process which might explain the observed rhythmicity of enzymic properties. PMID:3707571

  13. Toward a better knowledge of the molecular evolution of phosphoenolpyruvate carboxylase by comparison of partial cDNA sequences.

    Science.gov (United States)

    Gehrig, H H; Heute, V; Kluge, M

    1998-01-01

    To get deeper insight into the evolution of phosphoenolpyruvate carboxylase we have identified PEPC fragments (about 1,100 bp) of another 12 plants species not yet investigated in this context. The selected plants include one Chlorophyta, two Bryophyta, four Pteridophyta, and five Spermatophyta species. The obtained phylogenetic trees on PEPC isoforms are the most complete ones up to now available. Independent of their manner of construction, the resulting dendrograms are very similar and fully consistent with the main topology as it is postulated for the evolution of the higher terrestrial plants. We found a distinct clustering of the PEPC sequences of the prokaryotes, the algae, and the spermatophytes. PEPC isoforms of the archegoniates are located in the phylogenetic trees between the algae and spermatophytes. Our results strengthen the view that the PEPC is a very useful molecular marker with which to visualize phylogenetic trends both on the metabolic and organismic levels.

  14. Cloning, Expression and Purification of Wheat Acetyl-CoA Carboxylases CT Domain in E.coil

    Institute of Scientific and Technical Information of China (English)

    WANG Rui-jian; YANG Xue-ying; ZHENG Liang-yu; YANG Ye; GAO Gui; CAO Shu-gui

    2008-01-01

    The entire gene of carboxyltransferase(CT) domain of acetyl-CoA carboxylase(ACCase) from Chinese Spring wheat(CSW) plastid was cloned firstly,and the 2.3 kb gene was inserted into PET28a+ vector and expressed in E.coil in a soluble state.The (His)6 fusion protein was identified by SDS-PAGE and Western blot.The recombinant protein was purified by affinity chromatography,and the calculated molecular mass(Mr) was 88000.The results of the sequence analysis indicate that the cloned gene(GeneBank accession No.EU124675) was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid.The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides,and further to screen new herbicides.

  15. A 3-methylcrotonyl-CoA carboxylase deficient human skin fibroblast transcriptome reveals underlying mitochondrial dysfunction and oxidative stress.

    Science.gov (United States)

    Zandberg, L; van Dyk, H C; van der Westhuizen, F H; van Dijk, A A

    2016-09-01

    Isolated 3-methylcrotonyl-CoA carboxylase (MCC) deficiency is an autosomal recessive inherited metabolic disease of leucine catabolism with a highly variable phenotype. Apart from extensive mutation analyses of the MCCC1 and MCCC2 genes encoding 3-methylcrotonyl-CoA carboxylase (EC 6.4.1.4), molecular data on MCC deficiency gene expression studies in human tissues is lacking. For IEMs, unbiased '-omics' approaches are starting to reveal the secondary cellular responses to defects in biochemical pathways. Here we present the first whole genome expression profile of immortalized cultured skin fibroblast cells of two clinically affected MCC deficient patients and two healthy individuals generated using Affymetrix(®)HuExST1.0 arrays. There were 16191 significantly differentially expressed transcript IDs of which 3591 were well annotated and present in the predefined knowledge database of Ingenuity Pathway Analysis software used for downstream functional analyses. The most noticeable feature of this MCCA deficient skin fibroblast transcriptome was the typical genetic hallmark of mitochondrial dysfunction, decreased antioxidant response and disruption of energy homeostasis, which was confirmed by mitochondrial functional analyses. The MCC deficient transcriptome seems to predict oxidative stress that could alter the complex secondary cellular response that involve genes of the glycolysis, the TCA cycle, OXPHOS, gluconeogenesis, β-oxidation and the branched-chain fatty acid metabolism. An important emerging insight from this human MCCA transcriptome in combination with previous reports is that chronic exposure to the primary and secondary metabolites of MCC deficiency and the resulting oxidative stress might impact adversely on the quality of life and energy levels, irrespective of whether MCC deficient individuals are clinically affected or asymptomatic. PMID:27417235

  16. AcEST: DK960177 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 9. 5' end sequence. DK960177 CL2Contig2 Show DK960177 Clone id TST39A01NGRL0006_L09 Library TST39 Length 739... Definition Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0006_L09. 5' end sequence. Accession DK960177...tabase search programs, Nucleic Acids Res. 25:3389-3402. Query= DK960177|Adiantum capillus-veneris mRNA, clo...ylase small ch... 178 3e-44 sp|P16031|RBS_LARLA Ribulose bisphosphate carboxylase small chai... 177 4e-44 sp...|Q40004|RBS_HORVU Ribulose bisphosphate carboxylase small chai... 177 4e-44 sp|P1

  17. Seed Dormancy in Red Rice (Oryza sativa) (IX. Embryo Fructose-2,6-Bisphosphate during Dormancy Breaking and Subsequent Germination).

    Science.gov (United States)

    Footitt, S.; Cohn, M. A.

    1995-04-01

    Fructose-2,6-bisphosphate (Fru-2,6-bisP) was evaluated as a potential marker for the dormancy-breaking phase or the germination phase before pericarp splitting in red rice (Oryza sativa). During 4 h of imbibition at 30[deg]C, Fru-2,6-bisP of dehulled dormant and nondormant seeds increased to 0.26 and 0.38 pmol embryo-1, respectively. In nondormant seeds, embryo Fru-2,6-bisP content remained stable until the onset of pericarp splitting (12 h) and increased rapidly thereafter. In dormant seeds, Fru-2,6-bisP declined to 0.09 pmol embryo-1 at 24 h. Embryo Fru-2,6-bisP was correlated with O2 uptake of dormant and nondormant seeds. A 24-h exposure of dehulled, water-imbibed, dormant seeds to treatments yielding >90% germination (sodium nitrite [4 mM], propionic acid [22 mM], methyl propionate [32 mM], propanol [75 mM], and propionaldehyde [40 mM]) led to changes in embryo Fru-2,6-bisP that were unrelated to the final germination percentages. Furthermore, a 2-h pulse of propionaldehyde increased Fru-2,6-bisP 4-fold but did not break dormancy. Whereas nitrite and propionaldehyde increased Fru-2,6-bisP to 0.33 pmol embryo-1 after 2 h of contact, propionic acid and methyl propionate did not increase Fru-2,6-bisP above the untreated control. In all cases, further increases in Fru-2,6-bisP occurred after pericarp splitting. However, the plateau Fru-2,6-bisP attained during chemical contact was inversely correlated with elapsed time to 30% germination (r = -0.978). Therefore, although Fru-2,6-bisP is not a universal marker for dormancy release, its rapid increase during nitrite and propionaldehyde treatments suggests that events associated with dormancy breaking can occur within 2 h of chemical treatment.

  18. Measurement of Acylcarnitine Substrate to Product Ratios Specific to Biotin-Dependent Carboxylases Offers a Combination of Indicators of Biotin Status in Humans12

    OpenAIRE

    Bogusiewicz, Anna; Horvath, Thomas D; Stratton, Shawna L.; Mock, Donald M; Boysen, Gunnar

    2012-01-01

    This work describes a novel liquid chromatography tandem MS (LC-MS/MS) method for the determination of ratios of acylcarnitines arising from acyl-CoA substrates and products that reflect metabolic disturbances caused by marginal biotin deficiency. The urinary ratios reflecting reduced activities of biotin-dependent enzymes include the following: 1) the ratio of 3-hydroxyisovalerylcarnitine : 3-methylglutarylcarnitine (3HIAc : MGc) for methylcrotonyl-CoA carboxylase; 2) the ratio of propionylc...

  19. Targeting of proteins to the thylakoid lumen by the bipartite transit peptide of the 33 kd oxygen-evolving protein.

    OpenAIRE

    Ko, K.; Cashmore, A. R.

    1989-01-01

    Various chimeric precursors and deletions of the 33 kd oxygen-evolving protein (OEE1) were constructed to study the mechanism by which chloroplast proteins are imported and targeted to the thylakoid lumen. The native OEE1 precursor was imported into isolated chloroplasts, processed and localized in the thylakoid lumen. Replacement of the OEE1 transit peptide with the transit peptide of the small subunit of ribulose-1,5-bisphosphate carboxylase, a stromal protein, resulted in redirection of ma...

  20. Promotive Effect of Low Concentrations of NaHSO3 on Photophosphorylation and Photosynthesis in Phosphoenolpyruvate Carboxylase Transgenic Rice Leaves

    Institute of Scientific and Technical Information of China (English)

    Ben-Hua JI; Hong-He TAN; Rong ZHOU; De-Mao JIAO; Yun-Gang SHEN

    2005-01-01

    Spraying a 1-2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.)Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC+phosphate dikinase (PPDK) transgenic rice (PC+PK), in which the germplasm was transformed with wild-type Kitaake as the gene receptor, resulted in an enhancement of the net photosynthetic rate by 23.0%, 28.8%, and 34.4%,respectively, for more than 3 d. It was also observed that NaHSO3 application caused an increase in the ATP content in leaves. Spraying PMS (a cofactor catalysing the photophosphorylation cycle) and NaHSO3 separately or together on leaves resulted in an increase in photosynthesis with all treatments. There was no additional effect on photosynthetic rate when the mixture was applied, suggesting that the mechanism by which NaHSO3 promotes photosynthesis is similar to the mechanism by which PMS acts and that both of compounds enhanced the supply of ATP. After spraying a solution of NaHSO3 on leaves, compared with the WT Kitaake rice, a greater enhancement of net photosynthetic rate was observed in PEPC transgenic (PC) and PEPC+PPDK transgenic (PC+PK) rice, with the greatest increase being observed in the latter group. Therefore ATP supply may become the limiting factor that concentrates CO2 in rice leaves transformed with an exogenous PEPC gene and exogenous PEPC+PPDK genes.

  1. Liver-specific γ-glutamyl carboxylase-deficient mice display bleeding diathesis and short life span.

    Directory of Open Access Journals (Sweden)

    Kotaro Azuma

    Full Text Available Vitamin K is a fat-soluble vitamin that plays important roles in blood coagulation and bone metabolism. One of its functions is as a co-factor for γ-glutamyl carboxylase (Ggcx. Conventional knockout of Ggcx causes death shortly after birth in homozygous mice. We created Ggcx-floxed mice by inserting loxP sequences at the sites flanking exon 6 of Ggcx. By mating these mice with albumin-Cre mice, we generated Ggcx-deficient mice specifically in hepatocytes (Ggcx(Δliver/Δliver mice. In contrast to conventional Ggcx knockout mice, Ggcx(Δliver/Δliver mice had very low activity of Ggcx in the liver and survived several weeks after birth. Furthermore, compared with heterozygous mice (Ggcx(+/Δliver , Ggcx(Δliver/Δliver mice had shorter life spans. Ggcx(Δliver/Δliver mice displayed bleeding diathesis, which was accompanied by decreased activity of coagulation factors II and IX. Ggcx-floxed mice can prove useful in examining Ggcx functions in vivo.

  2. Pyruvate Carboxylase Activates the RIG-I-like Receptor-Mediated Antiviral Immune Response by Targeting the MAVS signalosome

    Science.gov (United States)

    Cao, Zhongying; Zhou, Yaqin; Zhu, Shengli; Feng, Jian; Chen, Xueyuan; Liu, Shi; Peng, Nanfang; Yang, Xiaodan; Xu, Gang; Zhu, Ying

    2016-01-01

    When retinoic acid-inducible gene 1 protein (RIG-I)-like receptors sense viral dsRNA in the cytosol, RIG-I and melanoma differentiation-associated gene 5 (MDA5) are recruited to the mitochondria to interact with mitochondrial antiviral signaling protein (MAVS) and initiate antiviral immune responses. In this study, we demonstrate that the biotin-containing enzyme pyruvate carboxylase (PC) plays an essential role in the virus-triggered activation of nuclear factor kappa B (NF-κB) signaling mediated by MAVS. PC contributes to the enhanced production of type I interferons (IFNs) and pro-inflammatory cytokines, and PC knockdown inhibits the virus-triggered innate immune response. In addition, PC shows extensive antiviral activity against RNA viruses, including influenza A virus (IAV), human enterovirus 71 (EV71), and vesicular stomatitis virus (VSV). Furthermore, PC mediates antiviral action by targeting the MAVS signalosome and induces IFNs and pro-inflammatory cytokines by promoting phosphorylation of NF-κB inhibitor-α (IκBα) and the IκB kinase (IKK) complex, as well as NF-κB nuclear translocation, which leads to activation of interferon-stimulated genes (ISGs), including double-stranded RNA-dependent protein kinase (PKR) and myxovirus resistance protein 1 (Mx1). Our findings suggest that PC is an important player in host antiviral signaling. PMID:26906558

  3. Chemical inhibition of acetyl-CoA carboxylase suppresses self-renewal growth of cancer stem cells

    Science.gov (United States)

    Corominas-Faja, Bruna; Cuyàs, Elisabet; Gumuzio, Juan; Bosch-Barrera, Joaquim; Leis, Olatz; Martin, Ángel G.; Menendez, Javier A.

    2014-01-01

    Cancer stem cells (CSC) may take advantage of the Warburg effect-induced siphoning of metabolic intermediates into de novo fatty acid biosynthesis to increase self-renewal growth. We examined the anti-CSC effects of the antifungal polyketide soraphen A, a specific inhibitor of the first committed step of lipid biosynthesis catalyzed by acetyl-CoA carboxylase (ACACA). The mammosphere formation capability of MCF-7 cells was reduced following treatment with soraphen A in a dose-dependent manner. MCF-7 cells engineered to overexpress the oncogene HER2 (MCF-7/HER2 cells) were 5-fold more sensitive than MCF-7 parental cells to soraphen A-induced reductions in mammosphere-forming efficiency. Soraphen A treatment notably decreased aldehyde dehydrogenase (ALDH)-positive CSC-like cells and impeded the HER2's ability to increase the ALDH+-stem cell population. The following results confirmed that soraphen A-induced suppression of CSC populations occurred through ACACA-driven lipogenesis: a.) exogenous supplementation with supraphysiological concentrations of oleic acid fully rescued mammosphere formation in the presence of soraphen A and b.) mammosphere cultures of MCF-7 cells with stably silenced expression of the cytosolic isoform ACACA1, which specifically participates in de novo lipogenesis, were mostly refractory to soraphen A treatment. Our findings reveal for the first time that ACACA may constitute a previously unrecognized target for novel anti-breast CSC therapies. PMID:25246709

  4. Brain Glycogenolysis, Adrenoceptors, Pyruvate Carboxylase, Na+,K+-ATPase and Marie E. Gibbs’ Pioneering Learning Studies

    Directory of Open Access Journals (Sweden)

    Leif eHertz

    2013-04-01

    Full Text Available The involvement of glycogenolysis, occurring in astrocytes but not in neurons, in learning is undisputed (Duran et al., JCBFM, in press. According to one school of thought the role of astrocytes for learning is restricted to supply of substrate for neuronal oxidative metabolism. The present ‘perspective’ suggests a more comprehensive and complex role, made possible by lack of glycogen degradation, unless specifically induced by either i activation of astrocytic receptors, perhaps especially beta-adrenergic, or ii even small increases in extracellular K+ concentration above its normal resting level. It discusses i the known importance of glycogenolysis for glutamate formation, requiring pyruvate carboxylation; ii the established role of K+-stimulated glycogenolysis for K+ uptake in cultured astrocytes, which probably indicates that astrocytes are an integral part of cellular K+ homeostasis in the brain in vivo; and iii the plausible role of transmitter-induced glycogenolysis, stimulating Na+,K+-ATPase/NKCC1 activity and thereby contributing both to the post-excitatory undershoot in extracellular K+ concentration and the memory-enhancing effect of transmitter-mediated reduction of slow neuronal afterhyperpolarization (sAHP.

  5. Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae.

    Directory of Open Access Journals (Sweden)

    Roger Huerlimann

    Full Text Available The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT, and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid and in two forms (homomeric and heteromeric. All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa and Chromista (Stramenopiles, Haptophyta and Cryptophyta have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO, Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta. These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was

  6. Metabolic regulation of invadopodia and invasion by acetyl-CoA carboxylase 1 and de novo lipogenesis.

    Directory of Open Access Journals (Sweden)

    Kristen E N Scott

    Full Text Available Invadopodia are membrane protrusions that facilitate matrix degradation and cellular invasion. Although lipids have been implicated in several aspects of invadopodia formation, the contributions of de novo fatty acid synthesis and lipogenesis have not been defined. Inhibition of acetyl-CoA carboxylase 1 (ACC1, the committed step of fatty acid synthesis, reduced invadopodia formation in Src-transformed 3T3 (3T3-Src cells, and also decreased the ability to degrade gelatin. Inhibition of fatty acid synthesis through AMP-activated kinase (AMPK activation and ACC phosphorylation also decreased invadopodia incidence. The addition of exogenous 16∶0 and 18∶1 fatty acid, products of de novo fatty acid synthesis, restored invadopodia and gelatin degradation to cells with decreased ACC1 activity. Pharmacological inhibition of ACC also altered the phospholipid profile of 3T3-Src cells, with the majority of changes occurring in the phosphatidylcholine (PC species. Exogenous supplementation with the most abundant PC species, 34∶1 PC, restored invadopodia incidence, the ability to degrade gelatin and the ability to invade through matrigel to cells deficient in ACC1 activity. On the other hand, 30∶0 PC did not restore invadopodia and 36∶2 PC only restored invadopodia incidence and gelatin degradation, but not cellular invasion through matrigel. Pharmacological inhibition of ACC also reduced the ability of MDA-MB-231 breast, Snb19 glioblastoma, and PC-3 prostate cancer cells to invade through matrigel. Invasion of PC-3 cells through matrigel was also restored by 34∶1 PC supplementation. Collectively, the data elucidate the novel metabolic regulation of invadopodia and the invasive process by de novo fatty acid synthesis and lipogenesis.

  7. Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae.

    KAUST Repository

    Huerlimann, Roger

    2015-07-01

    The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT), and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid) and in two forms (homomeric and heteromeric). All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa) and Chromista (Stramenopiles, Haptophyta and Cryptophyta) have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO), Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta). These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was acquired by the

  8. Abundance and distribution of archaeal acetyl-CoA/propionyl-CoA carboxylase genes indicative for putatively chemoautotrophic Archaea in the tropical Atlantic's interior

    OpenAIRE

    Bergauer, Kristin; Sintes, Eva; van Bleijswijk, Judith; Witte, Harry; Herndl, Gerhard J.; Lueders, Tillmann

    2013-01-01

    Recently, evidence suggests that dark CO2 fixation in the pelagic realm of the ocean does not only occur in the suboxic and anoxic water bodies but also in the oxygenated meso- and bathypelagic waters of the North Atlantic. To elucidate the significance and phylogeny of the key organisms mediating dark CO2 fixation in the tropical Atlantic, we quantified functional genes indicative for CO2 fixation. We used a Q-PCR-based assay targeting the bifunctional acetyl-CoA/propionyl-CoA carboxylase (a...

  9. Psychosine-triggered endomitosis is modulated by membrane sphingolipids through regulation of phosphoinositide 4,5-bisphosphate production at the cleavage furrow.

    Science.gov (United States)

    Watanabe, Hiroshi; Okahara, Kyohei; Naito-Matsui, Yuko; Abe, Mitsuhiro; Go, Shinji; Inokuchi, Jinichi; Okazaki, Toshiro; Kobayashi, Toshihide; Kozutsumi, Yasunori; Oka, Shogo; Takematsu, Hiromu

    2016-07-01

    Endomitosis is a special type of mitosis in which only cytokinesis-the final step of the cell division cycle-is defective, resulting in polyploid cells. Although endomitosis is biologically important, its regulatory aspects remain elusive. Psychosine, a lysogalactosylceramide, prevents proper cytokinesis when supplemented to proliferating cells. Cytokinetic inhibition by psychosine does not inhibit genome duplication. Consequently cells undergo multiple rounds of endomitotic cell cycles, resulting in the formation of giant multiploid cells. Here we successfully quantified psychosine-triggered multiploid cell formation, showing that membrane sphingolipids ratios modulate psychosine-triggered polyploidy in Namalwa cells. Among enzymes that experimentally remodel cellular sphingolipids, overexpression of glucosylceramide synthase to biosynthesize glycosylsphingolipids (GSLs) and neutral sphingomyelinase 2 to hydrolyze sphingomyelin (SM) additively enhanced psychosine-triggered multiploidy; almost all of the cells became polyploid. In the presence of psychosine, Namalwa cells showed attenuated cell surface SM clustering and suppression of phosphatidylinositol 4,5-bisphosphate production at the cleavage furrow, both important processes for cytokinesis. Depending on the sphingolipid balance between GSLs and SM, Namalwa cells could be effectively converted to viable multiploid cells with psychosine. PMID:27170180

  10. Rapid Structural Changes and Acidification of Guard Cell Vacuoles during Stomatal Closure Require Phosphatidylinositol 3,5-Bisphosphate[C][W

    Science.gov (United States)

    Bak, Gwangbae; Lee, Eun-Jung; Lee, Yuree; Kato, Mariko; Segami, Shoji; Sze, Heven; Maeshima, Masayoshi; Hwang, Jae-Ung; Lee, Youngsook

    2013-01-01

    Rapid stomatal closure is essential for water conservation in plants and is thus critical for survival under water deficiency. To close stomata rapidly, guard cells reduce their volume by converting a large central vacuole into a highly convoluted structure. However, the molecular mechanisms underlying this change are poorly understood. In this study, we used pH-indicator dyes to demonstrate that vacuolar convolution is accompanied by acidification of the vacuole in fava bean (Vicia faba) guard cells during abscisic acid (ABA)–induced stomatal closure. Vacuolar acidification is necessary for the rapid stomatal closure induced by ABA, since a double mutant of the vacuolar H+-ATPase vha-a2 vha-a3 and vacuolar H+-PPase mutant vhp1 showed delayed stomatal closure. Furthermore, we provide evidence for the critical role of phosphatidylinositol 3,5-bisphosphate [PtdIns(3,5)P2] in changes in pH and morphology of the vacuole. Single and double Arabidopsis thaliana null mutants of phosphatidylinositol 3-phosphate 5-kinases (PI3P5Ks) exhibited slow stomatal closure upon ABA treatment compared with the wild type. Moreover, an inhibitor of PI3P5K reduced vacuolar acidification and convolution and delayed stomatal closure in response to ABA. Taken together, these results suggest that rapid ABA-induced stomatal closure requires PtdIns(3,5)P2, which is essential for vacuolar acidification and convolution. PMID:23757398

  11. Influence of the nitrate concentration and source in the incorporation of 14CO2 by the RuBP-carboxylase from wheat (triticum aestivum) and maize (zea mays)

    International Nuclear Information System (INIS)

    The effect of the concentration and source of nitrogen in the culture media has been studied regarding its influence in the activity of the RuBP-carboxylase from wheat and maize during the first month of development. Wheat and maize has been chosen as plants representatives of two different types of CO2 assimilation: C3 and M- respectively. Plants have been grown in hydroponic media and under temperature, humidity and nutrient salts control. A negative effect of NH4 has been observed in the enzymatic activity of wheat seedlings, being this effect more remarkable as NH4 concentration increases and as long the time of treatment. In our experimental conditions the most favorable source of nitrogen has been N03NH4. The specific activity of the enzyme from wheat is about four times higher than in maize, even it decreases with time. This decreasing has not been observed in maize, with the exception of total absence of nitrogen in the media. We have not seen significant differences between the two photo periods which have been tested. Also, no differences have been found in the enzyme activities at the different NO3NH4 concentrations assayed, and it seems that RuBP-carboxylase metabolism is only affected in the case of absolute stress. (Author) 20 refs

  12. The cyclic keto-enol insecticide spirotetramat inhibits insect and spider mite acetyl-CoA carboxylases by interfering with the carboxyltransferase partial reaction.

    Science.gov (United States)

    Lümmen, Peter; Khajehali, Jahangir; Luther, Kai; Van Leeuwen, Thomas

    2014-12-01

    Acetyl-CoA carboxylase (ACC) catalyzes the committed and rate-limiting step in fatty acid biosynthesis. The two partial reactions, carboxylation of biotin followed by carboxyl transfer to the acceptor acetyl-CoA, are performed by two separate domains in animal ACCs. The cyclic keto-enol insecticides and acaricides have been proposed to inhibit insect ACCs. In this communication, we show that the enol derivative of the cylic keto-enol insecticide spirotetramat inhibited ACCs partially purified from the insect species Myzus persicae and Spodoptera frugiperda, as well as the spider mite (Tetranychus urticae) ACC which was expressed in insect cells using a recombinant baculovirus. Steady-state kinetic analysis revealed competitive inhibition with respect to the carboxyl acceptor, acetyl-CoA, indicating that spirotetramat-enol bound to the carboxyltransferase domain of ACC. Interestingly, inhibition with respect to the biotin carboxylase substrate ATP was uncompetitive. Amino acid residues in the carboxyltransferase domains of plant ACCs are important for binding of established herbicidal inhibitors. Mutating the spider mite ACC at the homologous positions, for example L1736 to either isoleucine or alanine, and A1739 to either valine or serine, did not affect the inhibition of the spider mite ACC by spirotetramat-enol. These results indicated different binding modes of the keto-enols and the herbicidal chemical families.

  13. Moringa oleifera leaf extract ameliorates alloxan-induced diabetes in rats by regeneration of β cells and reduction of pyruvate carboxylase expression.

    Science.gov (United States)

    Abd El Latif, Amira; El Bialy, Badr El Said; Mahboub, Hamada Dahi; Abd Eldaim, Mabrouk Attia

    2014-10-01

    Moringa oleifera Lam. contains many active ingredients with nutritional and medicinal values. It is commonly used in folk medicine as an antidiabetic agent. The present study was designed to investigate how an aqueous extract from the leaves of M. oleifera reveals hypoglycemia in diabetic rats. M. oleifera leaf extract counteracted the alloxan-induced diabetic effects in rats as it normalized the elevated serum levels of glucose, triglycerides, cholesterol, and malondialdehyde, and normalized mRNA expression of the gluconeogenic enzyme pyruvate carboxylase in hepatic tissues. It also increased live body weight gain and normalized the reduced mRNA expression of fatty acid synthase in the liver of diabetic rats. Moreover, it restored the normal histological structure of the liver and pancreas damaged by alloxan in diabetic rats. This study revealed that the aqueous extract of M. oleifera leaves possesses potent hypoglycemic effects through the normalization of elevated hepatic pyruvate carboxylase enzyme and regeneration of damaged hepatocytes and pancreatic β cells via its antioxidant properties.

  14. Characterization of the S. cerevisiae inp51 mutant links phosphatidylinositol 4,5-bisphosphate levels with lipid content, membrane fluidity and cold growth.

    Science.gov (United States)

    Córcoles-Sáez, Isaac; Hernández, Maria Luisa; Martínez-Rivas, Jose Manuel; Prieto, Jose A; Randez-Gil, Francisca

    2016-03-01

    Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and its derivatives diphosphoinositol phosphates (DPIPs) play key signaling and regulatory roles. However, a direct function of these molecules in lipid and membrane homeostasis remains obscure. Here, we have studied the cold tolerance phenotype of yeast cells lacking the Inp51-mediated phosphoinositide-5-phosphatase. Genetic and biochemical approaches showed that increased metabolism of PI(4,5)P2 reduces the activity of the Pho85 kinase by increasing the levels of the DPIP isomer 1-IP7. This effect was key in the cold tolerance phenotype. Indeed, pho85 mutant cells grew better than the wild-type at 15 °C, and lack of this kinase abolished the inp51-mediated cold phenotype. Remarkably, reduced Pho85 function by loss of Inp51 affected the activity of the Pho85-regulated target Pah1, the yeast phosphatidate phosphatase. Cells lacking Inp51 showed reduced Pah1 abundance, derepression of an INO1-lacZ reporter, decreased content of triacylglycerides and elevated levels of phosphatidate, hallmarks of the pah1 mutant. However, the inp51 phenotype was not associated to low Pah1 activity since deletion of PAH1 caused cold sensitivity. In addition, the inp51 mutant exhibited features not shared by pah1, including a 40%-reduction in total lipid content and decreased membrane fluidity. These changes may influence the activity of membrane-anchored and/or associated proteins since deletion of INP51 slows down the transit to the vacuole of the fluorescent dye FM4-64. In conclusion, our work supports a model in which changes in the PI(4,5)P2 pool affect the 1-IP7 levels modulating the activity of Pho85, Pah1 and likely additional Pho85-controlled targets, and regulate lipid composition and membrane properties. PMID:26724696

  15. Plasma membrane phosphatidylinositol 4,5 bisphosphate is required for internalization of foot-and-mouth disease virus and vesicular stomatitis virus.

    Directory of Open Access Journals (Sweden)

    Angela Vázquez-Calvo

    Full Text Available Phosphatidylinositol-4,5-bisphosphate, PI(4,5P(2, is a phospholipid which plays important roles in clathrin-mediated endocytosis. To investigate the possible role of this lipid on viral entry, two viruses important for animal health were selected: the enveloped vesicular stomatitis virus (VSV - which uses a well characterized clathrin mediated endocytic route - and two different variants of the non-enveloped foot-and-mouth disease virus (FMDV with distinct receptor specificities. The expression of a dominant negative dynamin, a PI(4,5P(2 effector protein, inhibited the internalization and infection of VSV and both FMDV isolates. Depletion of PI(4,5P(2 from plasma membrane using ionomycin or an inducible system, and inhibition of its de novo synthesis with 1-butanol revealed that VSV as well as FMDV C-S8c1, which uses integrins as receptor, displayed a high dependence on PI(4,5P(2 for internalization. Expression of a kinase dead mutant (KD of phosphatidylinositol-4-phosphate-5-kinase Iα (PIP5K-Iα, an enzyme responsible for PI(4,5P(2 synthesis that regulates clathrin-dependent endocytosis, also impaired entry and infection of VSV and FMDV C-S8c1. Interestingly FMDV MARLS variant that uses receptors other than integrins for cell entry was less sensitive to PI(4,5P(2 depletion, and was not inhibited by the expression of the KD PIP5K-Iα mutant suggesting the involvement of endocytic routes other than the clathrin-mediated on its entry. These results highlight the role of PI(4,5P(2 and PIP5K-Iα on clathrin-mediated viral entry.

  16. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    Science.gov (United States)

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  17. The bacterial-type phosphoenolpyruvate carboxylase isozyme from developing castor oil seeds is subject to in vivo regulatory phosphorylation at serine-451.

    Science.gov (United States)

    Dalziel, Katie J; O'Leary, Brendan; Brikis, Carolyne; Rao, Srinath K; She, Yi-Min; Cyr, Terry; Plaxton, William C

    2012-04-01

    Phosphoenolpyruvate carboxylase (PEPC) is a tightly controlled anaplerotic enzyme situated at a pivotal branch point of plant carbohydrate-metabolism. In developing castor oil seeds (COS) a novel allosterically-densensitized 910-kDa Class-2 PEPC hetero-octameric complex arises from a tight interaction between 107-kDa plant-type PEPC and 118-kDa bacterial-type PEPC (BTPC) subunits. Mass spectrometry and immunoblotting with anti-phosphoSer451 specific antibodies established that COS BTPC is in vivo phosphorylated at Ser451, a highly conserved target residue that occurs within an intrinsically disordered region. This phosphorylation was enhanced during COS development or in response to depodding. Kinetic characterization of a phosphomimetic (S451D) mutant indicated that Ser451 phosphorylation inhibits the catalytic activity of BTPC subunits within the Class-2 PEPC complex.

  18. Isolation of a cDNA for a phosphoenolpyruvate carboxylase from a monocot CAM-plant, Aloe arborescens: structure and its gene expression.

    Science.gov (United States)

    Honda, H; Okamoto, T; Shimada, H

    1996-09-01

    A phosphoenolpyruvate carboxylase (PEPCase) cDNA was isolated from Aloe arborescens, a monocot CAM plant. Northern analysis of the PEPCase transcript indicated that it is specifically expressed in green leaves, strongly suggesting its involvement in CAM photosynthesis. No diurnal change in expression level was evident. Western blot analysis also showed no alteration of the amount of the PEPCase protein. These results suggest that circadian rhythm in PEPCase activity may be regulated post-translationally. The representative cDNA clone contained an ORF encoding 964 amino acid residues. Deduced amino acid sequence of the aloe PEPCase is highly conserved as compared with other PEPCases. The phosphorylation site which may be modified by PEPC-kinase was conserved. An evolutional map with known PEPCases suggested that CAM-type PEPCases were located between C4 and housekeeping PEPCases. PMID:8888625

  19. Cloning and Characterization of a Pyruvate Carboxylase Gene from Penicillium rubens and Overexpression of the Genein the Yeast Yarrowia lipolytica for Enhanced Citric Acid Production.

    Science.gov (United States)

    Fu, Ge-Yi; Lu, Yi; Chi, Zhe; Liu, Guang-Lei; Zhao, Shou-Feng; Jiang, Hong; Chi, Zhen-Ming

    2016-02-01

    In this study, a pyruvate carboxylase gene (PYC1) from a marine fungus Penicillium rubens I607 was cloned and characterized. ORF of the gene (accession number: KM397349.1) had 3534 bp encoding 1177 amino acids with a molecular weight of 127.531 kDa and a PI of 6.20. The promoter of the gene was located at -1200 bp and contained a TATAA box, several CAAT boxes and a sequence 5'-SYGGRG-3'. The PYC1 deduced from the gene had no signal peptide, was a homotetramer (α4), and had the four functional domains. After expression of the PYC1 gene from the marine fungus in the marine-derived yeast Yarrowia lipolytica SWJ-1b, the transformant PR32 obtained had much higher specific pyruvate carboxylase activity (0.53 U/mg) than Y. lipolytica SWJ-1b (0.07 U/mg), and the PYC1 gene expression (133.8%) and citric acid production (70.2 g/l) by the transformant PR32 were also greatly enhanced compared to those (100 % and 27.3 g/l) by Y. lipolytica SWJ-1b. When glucose concentration in the medium was 60.0 g/l, citric acid (CA) concentration formed by the transformant PR32 was 36.1 g/l, leading to conversion of 62.1% of glucose into CA. During a 10-l fed-batch fermentation, the final concentration of CA was 111.1 ± 1.3 g/l, the yield was 0.93 g/g, the productivity was 0.46 g/l/h, and only 1.72 g/l reducing sugar was left in the fermented medium within 240 h. HPLC analysis showed that most of the fermentation products were CA. However, minor malic acid and other unknown products also existed in the culture.

  20. New insights into the post-translational modification of multiple phosphoenolpyruvate carboxylase isoenzymes by phosphorylation and monoubiquitination during sorghum seed development and germination.

    Science.gov (United States)

    Ruiz-Ballesta, Isabel; Baena, Guillermo; Gandullo, Jacinto; Wang, Liqun; She, Yi-Min; Plaxton, William Charles; Echevarría, Cristina

    2016-05-01

    Phosphoenolpyruvate carboxylase (PEPC; E.C. 4.1.1.31) was characterized in developing and germinating sorghum seeds, focusing on the transcript and polypeptide abundance of multiple plant-type phosphoenolpyruvate carboxylase (PTPC) genes, and the post-translational modification of each isoenzyme by phosphorylation versus monoubiquitination during germination. We observed high levels of SbPPC4 (Sb07g014960) transcripts during early development (stage I), and extensive transcript abundance of SbPPC2 (Sb02g021090) and SbPPC3 (Sb04g008720) throughout the entire life cycle of the seed. Although tandem mass spectrometry (MS) analysis of immunopurified PTPC indicated that four different PTPC isoenzymes were expressed in the developing and germinating seeds, SbPPC3 was the most abundant isozyme of the developing seed, and of the embryo and the aleurone layer of germinating seeds. In vivo phosphorylation of the different PTPC isoenzymes at their conserved N-terminal seryl phosphorylation site during germination was also established by MS/MS analysis. Furthermore, three of the four isoenzymes were partially monoubiquitinated, with MS/MS pinpointing SbPPC2 and SbPPC3 monoubiquitination at the conserved Lys-630 and Lys-624 residues, respectively. Our results demonstrate that monoubiquitination and phosphorylation simultaneously occur in vivo with different PTPC isozymes during seed germination. In addition, we show that PTPC monoubiquitination in germinating sorghum seeds always increases at stage II (emergence of the radicle), is maintained during the aerobic period of rapid cell division and reserve mobilization, and remains relatively constant until stage IV-V when coleoptiles initiate the formation of the photosynthetic tissues.

  1. New insights into the post-translational modification of multiple phosphoenolpyruvate carboxylase isoenzymes by phosphorylation and monoubiquitination during sorghum seed development and germination.

    Science.gov (United States)

    Ruiz-Ballesta, Isabel; Baena, Guillermo; Gandullo, Jacinto; Wang, Liqun; She, Yi-Min; Plaxton, William Charles; Echevarría, Cristina

    2016-05-01

    Phosphoenolpyruvate carboxylase (PEPC; E.C. 4.1.1.31) was characterized in developing and germinating sorghum seeds, focusing on the transcript and polypeptide abundance of multiple plant-type phosphoenolpyruvate carboxylase (PTPC) genes, and the post-translational modification of each isoenzyme by phosphorylation versus monoubiquitination during germination. We observed high levels of SbPPC4 (Sb07g014960) transcripts during early development (stage I), and extensive transcript abundance of SbPPC2 (Sb02g021090) and SbPPC3 (Sb04g008720) throughout the entire life cycle of the seed. Although tandem mass spectrometry (MS) analysis of immunopurified PTPC indicated that four different PTPC isoenzymes were expressed in the developing and germinating seeds, SbPPC3 was the most abundant isozyme of the developing seed, and of the embryo and the aleurone layer of germinating seeds. In vivo phosphorylation of the different PTPC isoenzymes at their conserved N-terminal seryl phosphorylation site during germination was also established by MS/MS analysis. Furthermore, three of the four isoenzymes were partially monoubiquitinated, with MS/MS pinpointing SbPPC2 and SbPPC3 monoubiquitination at the conserved Lys-630 and Lys-624 residues, respectively. Our results demonstrate that monoubiquitination and phosphorylation simultaneously occur in vivo with different PTPC isozymes during seed germination. In addition, we show that PTPC monoubiquitination in germinating sorghum seeds always increases at stage II (emergence of the radicle), is maintained during the aerobic period of rapid cell division and reserve mobilization, and remains relatively constant until stage IV-V when coleoptiles initiate the formation of the photosynthetic tissues. PMID:27194739

  2. New insights into the post-translational modification of multiple phosphoenolpyruvate carboxylase isoenzymes by phosphorylation and monoubiquitination during sorghum seed development and germination

    Science.gov (United States)

    Ruiz-Ballesta, Isabel; Baena, Guillermo; Gandullo, Jacinto; Wang, Liqun; She, Yi-Min; Plaxton, William Charles; Echevarría, Cristina

    2016-01-01

    Phosphoenolpyruvate carboxylase (PEPC; E.C. 4.1.1.31) was characterized in developing and germinating sorghum seeds, focusing on the transcript and polypeptide abundance of multiple plant-type phosphoenolpyruvate carboxylase (PTPC) genes, and the post-translational modification of each isoenzyme by phosphorylation versus monoubiquitination during germination. We observed high levels of SbPPC4 (Sb07g014960) transcripts during early development (stage I), and extensive transcript abundance of SbPPC2 (Sb02g021090) and SbPPC3 (Sb04g008720) throughout the entire life cycle of the seed. Although tandem mass spectrometry (MS) analysis of immunopurified PTPC indicated that four different PTPC isoenzymes were expressed in the developing and germinating seeds, SbPPC3 was the most abundant isozyme of the developing seed, and of the embryo and the aleurone layer of germinating seeds. In vivo phosphorylation of the different PTPC isoenzymes at their conserved N-terminal seryl phosphorylation site during germination was also established by MS/MS analysis. Furthermore, three of the four isoenzymes were partially monoubiquitinated, with MS/MS pinpointing SbPPC2 and SbPPC3 monoubiquitination at the conserved Lys-630 and Lys-624 residues, respectively. Our results demonstrate that monoubiquitination and phosphorylation simultaneously occur in vivo with different PTPC isozymes during seed germination. In addition, we show that PTPC monoubiquitination in germinating sorghum seeds always increases at stage II (emergence of the radicle), is maintained during the aerobic period of rapid cell division and reserve mobilization, and remains relatively constant until stage IV–V when coleoptiles initiate the formation of the photosynthetic tissues. PMID:27194739

  3. AcEST: BP915822 [AcEST

    Lifescience Database Archive (English)

    Full Text Available r_hit_id Q6Y9M7 Definition tr|Q6Y9M7|Q6Y9M7_9FILI Ribulose bisphosphate carboxylase large chain (Fragment) OS=Anogramma...9 6e-78 >tr|Q6Y9M7|Q6Y9M7_9FILI Ribulose bisphosphate carboxylase large chain (Fragment) OS=Anogramma leptop...FILI Ribulose bisphosphate carboxylase large chain (Fragment) OS=Anogramma guatemalensis GN=rbcL PE=3 SV=1 L

  4. Streptococcus pneumoniae fructose-1,6-bisphosphate aldolase, a protein vaccine candidate, elicits Th1/Th2/Th17-type cytokine responses in mice.

    Science.gov (United States)

    Elhaik Goldman, Shirin; Dotan, Shahar; Talias, Amir; Lilo, Amit; Azriel, Shalhevet; Malka, Itay; Portnoi, Maxim; Ohayon, Ariel; Kafka, Daniel; Ellis, Ronald; Elkabets, Moshe; Porgador, Angel; Levin, Ditza; Azhari, Rosa; Swiatlo, Edwin; Ling, Eduard; Feldman, Galia; Tal, Michael; Dagan, Ron; Mizrachi Nebenzahl, Yaffa

    2016-04-01

    Streptococcus pneumoniae (S. pneumoniae) is a major pathogen worldwide. The currently available polysaccharide-based vaccines significantly reduce morbidity and mortality. However, the inherent disadvantages of the currently available polysaccharide-based vaccines have motivated the search for other bacterial immunogens capable of eliciting a protective immune response against S. pneumoniae. Fructose-1,6-bisphosphate aldolase (FBA) is a glycolytic enzyme, which was found to localize to the bacterial surface, where it functions as an adhesin. Previously, immunizing mice with recombinant FBA (rFBA) in the presence of alum elicited a protective immune response against a lethal challenge with S. pneumoniae. Thus, the aim of the present study was to determine the cytokine responses that are indicative of protective immunity following immunization with rFBA. The protective effects against pneumococcal challenge in mice immunized with rFBA with complete Freund's adjuvant (CFA) in the initial immunization and with incomplete Freund's adjuvant (IFA) in booster immunizations surpassed the protective effects observed following immunization with either rFBA + alum or pVACfba. CD4+ T-cells obtained from the rFBA/CFA/IFA/IFA-immunized mice co-cultured with rFBA-pulsed antigen-presenting cells (APCs), exhibited a significantly greater proliferative ability than CD4+ T-cells obtained from the adjuvant-immunized mice co-cultured with rFBA‑pulsed APCs. The levels of the Th1-type cytokines, interferon (IFN)-γ, interleukin (IL)-2, tumor necrosis factor (TNF)-α and IL-12, the Th2-type cytokines, IL-4, IL-5 and IL-10, and the Th17-type cytokine, IL-17A, significantly increased within 72 h of the initiation of co-culture with CD4+ T-cells obtained from the rFBA‑immunized mice, in comparison with the co-cultures with CD4+ T-cells obtained from the adjuvant-immunized mice. Immunizing mice with rFBA resulted in an IgG1/IgG2 ratio of 41, indicating a Th2 response with substantial Th1

  5. The effect of nitrogen limitation on acetyl-CoA carboxylase expression and fatty acid content in Chromera velia and Isochrysis aff. galbana (TISO).

    Science.gov (United States)

    Huerlimann, Roger; Steinig, Eike J; Loxton, Heather; Zenger, Kyall R; Jerry, Dean R; Heimann, Kirsten

    2014-06-15

    Lipids from microalgae have become a valuable product with applications ranging from biofuels to human nutrition. While changes in fatty acid (FA) content and composition under nitrogen limitation are well documented, the involved molecular mechanisms are poorly understood. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the FA synthesis and elongation pathway. Plastidial and cytosolic ACCases provide malonyl-CoA for de novo FA synthesis in the plastid and FA elongation in the endoplasmic reticulum, respectively. The present study aimed at investigating the expression of plastidial and cytosolic ACCase in Chromera velia and Isochrysis aff. galbana (TISO) and their impact on FA content and elongation level when grown under nitrogen-deplete conditions. In C. velia, plastidial ACCase was significantly upregulated during nitrogen starvation and with culture age, strongly correlating with increased FA content. Conversely, plastidial ACCase of I. aff. galbana was not differentially expressed in nitrogen-deplete cultures, but upregulated during the logarithmic phase of nitrogen-replete cultures. In contrast to plastidial ACCase, the cytosolic ACCase of C. velia was downregulated with culture age and nitrogen-starvation, strongly correlating with an increase in medium-chain FAs. In conclusion, the expression of plastidial and cytosolic ACCase changed with growth phase and nutrient status in a species-specific manner and nitrogen limitation did not always result in FA accumulation.

  6. Maternal obesity reduces milk lipid production in lactating mice by inhibiting acetyl-CoA carboxylase and impairing fatty acid synthesis.

    Directory of Open Access Journals (Sweden)

    Jessica L Saben

    Full Text Available Maternal metabolic and nutrient trafficking adaptations to lactation differ among lean and obese mice fed a high fat (HF diet. Obesity is thought to impair milk lipid production, in part, by decreasing trafficking of dietary and de novo synthesized lipids to the mammary gland. Here, we report that de novo lipogenesis regulatory mechanisms are disrupted in mammary glands of lactating HF-fed obese (HF-Ob mice. HF feeding decreased the total levels of acetyl-CoA carboxylase-1 (ACC, and this effect was exacerbated in obese mice. The relative levels of phosphorylated (inactive ACC, were elevated in the epithelium, and decreased in the adipose stroma, of mammary tissue from HF-Ob mice compared to those of HF-fed lean (HF-Ln mice. Mammary gland levels of AMP-activated protein kinase (AMPK, which catalyzes formation of inactive ACC, were also selectively elevated in mammary glands of HF-Ob relative to HF-Ln dams or to low fat fed dams. These responses correlated with evidence of increased lipid retention in mammary adipose, and decreased lipid levels in mammary epithelial cells, of HF-Ob dams. Collectively, our data suggests that maternal obesity impairs milk lipid production, in part, by disrupting the balance of de novo lipid synthesis in the epithelial and adipose stromal compartments of mammary tissue through processes that appear to be related to increased mammary gland AMPK activity, ACC inhibition, and decreased fatty acid synthesis.

  7. Resistance to spiromesifen in Trialeurodes vaporariorum is associated with a single amino acid replacement in its target enzyme acetyl-coenzyme A carboxylase.

    Science.gov (United States)

    Karatolos, N; Williamson, M S; Denholm, I; Gorman, K; ffrench-Constant, R; Nauen, R

    2012-06-01

    Spiromesifen is a novel insecticide and is classed as a tetronic acid derivative. It targets the insects' acetyl-coenzyme A carboxylase (ACCase) enzyme, causing a reduction in lipid biosynthesis. At the time of this publication, there are no reports of resistance to this class of insecticides in insects although resistance has been observed in several mite species. The greenhouse whitefly Trialeurodes vaporariorum (Westwood) is a serious pest of protected vegetable and ornamental crops in temperate regions of the world and spiromesifen is widely used in its control. Mortality rates of UK and European populations of T. vaporariorum to spiromesifen were calculated and up to 26-fold resistance was found. We therefore sought to examine the molecular mechanism underlying spiromesifen resistance in this important pest. Pre-treatment with piperonyl butoxide did not synergize spiromesifen, suggesting a target-site resistance mechanism. The full length ACCase gene was sequenced for a range of T. vaporariorum strains and a strong association was found between spiromesifen resistance and a glutamic acid substitution with lysine in position 645 (E645K) of this gene. A TaqMan allelic discrimination assay confirmed these findings. Although this resistance is not considered sufficient to compromise the field performance of spiromesifen, this association of E645K with resistance is the first report of a potential target site mechanism affecting an ACCase inhibitor in an arthropod species.

  8. The glossyhead1 allele of acc1 reveals a principal role for multidomain acetyl-coenzyme a carboxylase in the biosynthesis of cuticular waxes by Arabidopsis

    KAUST Repository

    Lu, Shiyou

    2011-09-23

    A novel mutant of Arabidopsis (Arabidopsis thaliana), having highly glossy inflorescence stems, postgenital fusion in floral organs, and reduced fertility, was isolated from an ethyl methanesulfonate-mutagenized population and designated glossyhead1 (gsd1). The gsd1 locus was mapped to chromosome 1, and the causal gene was identified as a new allele of Acetyl-Coenzyme A Carboxylase1 (ACC1), a gene encoding the main enzyme in cytosolic malonyl-coenzyme A synthesis. This, to our knowledge, is the first mutant allele of ACC1 that does not cause lethality at the seed or early germination stage, allowing for the first time a detailed analysis of ACC1 function in mature tissues. Broad lipid profiling of mature gsd1 organs revealed a primary role for ACC1 in the biosynthesis of the very-long-chain fatty acids (C 20:0 or longer) associated with cuticular waxes and triacylglycerols. Unexpectedly, transcriptome analysis revealed that gsd1 has limited impact on any lipid metabolic networks but instead has a large effect on environmental stress-responsive pathways, especially senescence and ethylene synthesis determinants, indicating a possible role for the cytosolic malonyl-coenzyme A-derived lipids in stress response signaling. © 2011 American Society of Plant Biologists. All Rights Reserved.

  9. Decreasing the Rate of Metabolic Ketone Reduction in the Discovery of a Clinical Acetyl-CoA Carboxylase Inhibitor for the Treatment of Diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, David A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Kung, Daniel W. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Esler, William P. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Amor, Paul A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Bagley, Scott W. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Beysen, Carine [KineMed Inc., Emeryville, CA (United States); Carvajal-Gonzalez, Santos [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Doran, Shawn D. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Limberakis, Chris [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Mathiowetz, Alan M. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); McPherson, Kirk [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Price, David A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Ravussin, Eric [Louisiana State Univ., Baton Rouge, LA (United States); Sonnenberg, Gabriele E. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Southers, James A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Sweet, Laurel J. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Turner, Scott M. [KineMed Inc., Emeryville, CA (United States); Vajdos, Felix F. [Pfizer Worldwide Research and Development, Cambridge, MA (United States)

    2014-12-26

    We found that Acetyl-CoA carboxylase (ACC) inhibitors offer significant potential for the treatment of type 2 diabetes mellitus (T2DM), hepatic steatosis, and cancer. However, the identification of tool compounds suitable to test the hypothesis in human trials has been challenging. An advanced series of spirocyclic ketone-containing ACC inhibitors recently reported by Pfizer were metabolized in vivo by ketone reduction, which complicated human pharmacology projections. Here, we disclose that this metabolic reduction can be greatly attenuated through introduction of steric hindrance adjacent to the ketone carbonyl. Incorporation of weakly basic functionality improved solubility and led to the identification of 9 as a clinical candidate for the treatment of T2DM. Phase I clinical studies demonstrated dose-proportional increases in exposure, single-dose inhibition of de novo lipogenesis (DNL), and changes in indirect calorimetry consistent with increased whole-body fatty acid oxidation. This demonstration of target engagement validates the use of compound 9 to evaluate the role of DNL in human disease.

  10. Nuclear-cytoplasmic conflict in pea (Pisum sativum L.) is associated with nuclear and plastidic candidate genes encoding acetyl-CoA carboxylase subunits.

    Science.gov (United States)

    Bogdanova, Vera S; Zaytseva, Olga O; Mglinets, Anatoliy V; Shatskaya, Natalia V; Kosterin, Oleg E; Vasiliev, Gennadiy V

    2015-01-01

    In crosses of wild and cultivated peas (Pisum sativum L.), nuclear-cytoplasmic incompatibility frequently occurs manifested as decreased pollen fertility, male gametophyte lethality, sporophyte lethality. High-throughput sequencing of plastid genomes of one cultivated and four wild pea accessions differing in cross-compatibility was performed. Candidate genes for involvement in the nuclear-plastid conflict were searched in the reconstructed plastid genomes. In the annotated Medicago truncatula genome, nuclear candidate genes were searched in the portion syntenic to the pea chromosome region known to harbor a locus involved in the conflict. In the plastid genomes, a substantial variability of the accD locus represented by nucleotide substitutions and indels was found to correspond to the pattern of cross-compatibility among the accessions analyzed. Amino acid substitutions in the polypeptides encoded by the alleles of a nuclear locus, designated as Bccp3, with a complementary function to accD, fitted the compatibility pattern. The accD locus in the plastid genome encoding beta subunit of the carboxyltransferase of acetyl-coA carboxylase and the nuclear locus Bccp3 encoding biotin carboxyl carrier protein of the same multi-subunit enzyme were nominated as candidate genes for main contribution to nuclear-cytoplasmic incompatibility in peas. Existence of another nuclear locus involved in the accD-mediated conflict is hypothesized.

  11. Bacterial Hydrolysis of Protein and Methylated Protein and Its Implications for Studies of Protein Degradation in Aquatic Systems

    OpenAIRE

    Keil, Richard G.; Kirchman, David L.

    1992-01-01

    Ribulose 1,5-bisphosphate carboxylase was radiolabelled by in vitro translation, resulting in uniformly labelled ribulose 1,5-bisphosphate carboxylase, and also by reductive methylation. We investigated the degradation of the two forms of radiolabelled protein by natural bacterial populations. Although total hydrolysis of uniformly labelled protein and methylated protein was nearly equal, percent assimilation, respiration, and release as low-molecular-weight material were different. Radioacti...

  12. Discrimination in the dark. Resolving the interplay between metabolic and physical constraints to phosphoenolpyruvate carboxylase activity during the crassulacean acid metabolism cycle.

    Science.gov (United States)

    Griffiths, Howard; Cousins, Asaph B; Badger, Murray R; von Caemmerer, Susanne

    2007-02-01

    A model defining carbon isotope discrimination (delta13C) for crassulacean acid metabolism (CAM) plants was experimentally validated using Kalanchoe daigremontiana. Simultaneous measurements of gas exchange and instantaneous CO2 discrimination (for 13C and 18O) were made from late photoperiod (phase IV of CAM), throughout the dark period (phase I), and into the light (phase II). Measurements of CO2 response curves throughout the dark period revealed changing phosphoenolpyruvate carboxylase (PEPC) capacity. These systematic changes in PEPC capacity were tracked by net CO2 uptake, stomatal conductance, and online delta13C signal; all declined at the start of the dark period, then increased to a maximum 2 h before dawn. Measurements of delta13C were higher than predicted from the ratio of intercellular to external CO2 (p(i)/p(a)) and fractionation associated with CO2 hydration and PEPC carboxylations alone, such that the dark period mesophyll conductance, g(i), was 0.044 mol m(-2) s(-1) bar(-1). A higher estimate of g(i) (0.085 mol m(-2) s(-1) bar(-1)) was needed to account for the modeled and measured delta18O discrimination throughout the dark period. The differences in estimates of g(i) from the two isotope measurements, and an offset of -5.5 per thousand between the 18O content of source and transpired water, suggest spatial variations in either CO2 diffusion path length and/or carbonic anhydrase activity, either within individual cells or across a succulent leaf. Our measurements support the model predictions to show that internal CO2 diffusion limitations within CAM leaves increase delta13C discrimination during nighttime CO2 fixation while reducing delta13C during phase IV. When evaluating the phylogenetic distribution of CAM, carbon isotope composition will reflect these diffusive limitations as well as relative contributions from C3 and C4 biochemistry. PMID:17142488

  13. Pyruvate Carboxylase Is Up-Regulated in Breast Cancer and Essential to Support Growth and Invasion of MDA-MB-231 Cells.

    Directory of Open Access Journals (Sweden)

    Phatchariya Phannasil

    Full Text Available Pyruvate carboxylase (PC is an anaplerotic enzyme that catalyzes the carboxylation of pyruvate to oxaloacetate, which is crucial for replenishing tricarboxylic acid cycle intermediates when they are used for biosynthetic purposes. We examined the expression of PC by immunohistochemistry of paraffin-embedded breast tissue sections of 57 breast cancer patients with different stages of cancer progression. PC was expressed in the cancerous areas of breast tissue at higher levels than in the non-cancerous areas. We also found statistical association between the levels of PC expression and tumor size and tumor stage (P < 0.05. The involvement of PC with these two parameters was further studied in four breast cancer cell lines with different metastatic potentials; i.e., MCF-7, SKBR3 (low metastasis, MDA-MB-435 (moderate metastasis and MDA-MB-231 (high metastasis. The abundance of both PC mRNA and protein in MDA-MB-231 and MDA-MB-435 cells was 2-3-fold higher than that in MCF-7 and SKBR3 cells. siRNA-mediated knockdown of PC expression in MDA-MB-231 and MDA-MB-435 cells resulted in a 50% reduction of cell proliferation, migration and in vitro invasion ability, under both glutamine-dependent and glutamine-depleted conditions. Overexpression of PC in MCF-7 cells resulted in a 2-fold increase in their proliferation rate, migration and invasion abilities. Taken together the above results suggest that anaplerosis via PC is important for breast cancer cells to support their growth and motility.

  14. Computational simulations of structural role of the active-site W374C mutation of acetyl-coenzyme-A carboxylase: multi-drug resistance mechanism.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Wen-Chao; Yu, Ning-Xi; Yang, Sheng-Gang; Yang, Guang-Fu

    2011-03-01

    Herbicides targeting grass plastidic acetyl-CoA carboxylase (ACCase, EC 6.4.1.2) are selectively effective against graminicides. The intensive worldwide use of this herbicide family has selected for resistance genes in a number of grass weed species. Recently, the active-site W374C mutation was found to confer multi-drug resistance toward haloxyfop (HF), fenoxaprop (FR), Diclofop (DF), and clodinafop (CF) in A. myosuroides. In order to uncover the resistance mechanism due to W374C mutation, the binding of above-mentioned four herbicides to both wild-type and the mutant-type ACCase was investigated in the current work by molecular docking and molecular dynamics (MD) simulations. The binding free energies were calculated by molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) method. The calculated binding free energy values for four herbicides were qualitatively consistent with the experimental order of IC(50) values. All the computational model and energetic results indicated that the W374C mutation has great effects on the conformational change of the binding pocket and the ligand-protein interactions. The most significant conformational change was found to be associated with the aromatic amino acid residues, such as Phe377, Tyr161' and Trp346. As a result, the π-π interaction between the ligand and the residue of Phe377 and Tyr161', which make important contributions to the binding affinity, was decreased after mutation and the binding affinity for the inhibitors to the mutant-type ACCase was less than that to the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural role and mechanistic insights obtained from computational simulations will provide a new starting point for the rational design of novel inhibitors to overcome drug resistance associated with W374C mutation. PMID:20499260

  15. Bacterial- and plant-type phosphoenolpyruvate carboxylase isozymes from developing castor oil seeds interact in vivo and associate with the surface of mitochondria.

    Science.gov (United States)

    Park, Joonho; Khuu, Nicholas; Howard, Alexander S M; Mullen, Robert T; Plaxton, William C

    2012-07-01

    Phosphoenolpyruvate carboxylase (PEPC) from developing castor oil seeds (COS) exists as two distinct oligomeric isoforms. The typical class-1 PEPC homotetramer consists of 107-kDa plant-type PEPC (PTPC) subunits, whereas the allosterically desensitized 910-kDa class-2 PEPC hetero-octamer arises from the association of class-1 PEPC with 118-kDa bacterial-type PEPC (BTPC) subunits. The in vivo interaction and subcellular location of COS BTPC and PTPC were assessed by imaging fluorescent protein (FP)-tagged PEPCs in tobacco suspension-cultured cells. The BTPC-FP mainly localized to cytoplasmic punctate/globular structures, identified as mitochondria by co-immunostaining of endogenous cytochrome oxidase. Inhibition of respiration with KCN resulted in proportional decreases and increases in mitochondrial versus cytosolic BTPC-FP, respectively. The FP-PTPC and NLS-FP-PTPC (containing an appended nuclear localization signal, NLS) localized to the cytosol and nucleus, respectively, but both co-localized with mitochondrial-associated BTPC when co-expressed with BTPC-FP. Transmission electron microscopy of immunogold-labeled developing COS revealed that BTPC and PTPC are localized at the mitochondrial (outer) envelope, as well as the cytosol. Moreover, thermolysin-sensitive BTPC and PTPC polypeptides were detected on immunoblots of purified COS mitochondria. Overall, our results demonstrate that: (i) COS BTPC and PTPC interact in vivo as a class-2 PEPC complex that associates with the surface of mitochondria, (ii) BTPC's unique and divergent intrinsically disordered region mediates its interaction with PTPC, whereas (iii) the PTPC-containing class-1 PEPC is entirely cytosolic. We hypothesize that mitochondrial-associated class-2 PEPC facilitates rapid refixation of respiratory CO(2) while sustaining a large anaplerotic flux to replenish tricarboxylic acid cycle C-skeletons withdrawn for biosynthesis.

  16. Recombinant thermoactive phosphoenolpyruvate carboxylase (PEPC) from Thermosynechococcus elongatus and its coupling with mesophilic/thermophilic bacterial carbonic anhydrases (CAs) for the conversion of CO2 to oxaloacetate.

    Science.gov (United States)

    Del Prete, Sonia; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T; Carginale, Vincenzo

    2016-01-15

    With the continuous increase of atmospheric CO2 in the last decades, efficient methods for carbon capture, sequestration, and utilization are urgently required. The possibility of converting CO2 into useful chemicals could be a good strategy to both decreasing the CO2 concentration and for achieving an efficient exploitation of this cheap carbon source. Recently, several single- and multi-enzyme systems for the catalytic conversion of CO2 mainly to bicarbonate have been implemented. In order to design and construct a catalytic system for the conversion of CO2 to organic molecules, we implemented an in vitro multienzyme system using mesophilic and thermophilic enzymes. The system, in fact, was constituted by a recombinant phosphoenolpyruvate carboxylase (PEPC) from the thermophilic cyanobacterium Thermosynechococcus elongatus, in combination with mesophilic/thermophilic bacterial carbonic anhydrases (CAs), for converting CO2 into oxaloacetate, a compound of potential utility in industrial processes. The catalytic procedure is in two steps: the conversion of CO2 into bicarbonate by CA, followed by the carboxylation of phosphoenolpyruvate with bicarbonate, catalyzed by PEPC, with formation of oxaloacetate (OAA). All tested CAs, belonging to α-, β-, and γ-CA classes, were able to increase OAA production compared to procedures when only PEPC was used. Interestingly, the efficiency of the CAs tested in OAA production was in good agreement with the kinetic parameters for the CO2 hydration reaction of these enzymes. This PEPC also revealed to be thermoactive and thermostable, and when coupled with the extremely thermostable CA from Sulphurhydrogenibium azorense (SazCA) the production of OAA was achieved even if the two enzymes were exposed to temperatures up to 60 °C, suggesting a possible role of the two coupled enzymes in biotechnological processes.

  17. Expression and methylation of microsomal triglyceride transfer protein and acetyl-CoA carboxylase are associated with fatty liver syndrome in chicken.

    Science.gov (United States)

    Liu, Zhen; Li, Qinghe; Liu, Ranran; Zhao, Guiping; Zhang, Yonghong; Zheng, Maiqing; Cui, Huanxian; Li, Peng; Cui, Xiaoyan; Liu, Jie; Wen, Jie

    2016-06-01

    The typical characteristic of fatty liver syndrome (FLS) is an increased hepatic triacylglycerol content, and a sudden decline in egg production often occurs. FLS may develop into fatty liver hemorrhagic syndrome (FLHS), characterized by sudden death from hepatic rupture and hemorrhage. DNA methylation is associated with transcriptional silencing, leading to the etiology and pathogenesis of some animal diseases. The roles of DNA methylation in the genesis of FLS, however, are largely unknown. The lipogenic methyl-deficient diet (MDD) caused FLS similar to human nonalcoholic steatohepatitis (NASH). After 16 Jingxing-Huang (JXH) hens were fed MDD for 10 wk, eight exhibited FLS (designated as FLS-susceptible birds); the remainder, without FLS, served as controls (NFLS). Physiological and biochemical variables, gene expression levels, and DNA methylation were determined in the liver. The development of FLS in JXH hens was accompanied by abnormal lipid accumulation. Relative expression of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and microsomal triglyceride transfer protein (MTTP) were significantly up-regulated in the FLS group in comparison with the NFLS group. The transcript abundance of sterol regulatory element binding protein 1 (SREBP-1c), stearoyl-CoA desaturase (SCD), liver X receptor alpha (LXRα), peroxisome proliferator-activated receptor alpha (PPARα), and peroxisome proliferator-activated receptor gamma (PPARγ) did not differ between the two groups. Interestingly, MTTP and ACC mRNA abundance were negatively correlated with the level of promoter methylation. The extent of DNA methylation of the cytosine-guanine (CpG) sites in the SREBP-1c, FAS, PPARα, and LXRα promoter regions was also analyzed by direct sequencing but none differed between FLS and NFLS birds. Taken together, these results specify link DNA methylation to the pathogenesis of FLS in chickens. PMID:27083546

  18. Evaluation of pharmacokinetic/pharmacodynamic relationships of PD-0162819, a biotin carboxylase inhibitor representing a new class of antibacterial compounds, using in vitro infection models.

    Science.gov (United States)

    Ogden, Adam; Kuhn, Michael; Dority, Michael; Buist, Susan; Mehrens, Shawn; Zhu, Tong; Xiao, Deqing; Miller, J Richard; Hanna, Debra

    2012-01-01

    The present study investigated the pharmacokinetic/pharmacodynamic (PK/PD) relationships of a prototype biotin carboxylase (BC) inhibitor, PD-0162819, against Haemophilus influenzae 3113 in static concentration time-kill (SCTK) and one-compartment chemostat in vitro infection models. H. influenzae 3113 was exposed to PD-0162819 concentrations of 0.5 to 16× the MIC (MIC = 0.125 μg/ml) and area-under-the-curve (AUC)/MIC ratios of 1 to 1,100 in SCTK and chemostat experiments, respectively. Serial samples were collected over 24 h. For efficacy driver analysis, a sigmoid maximum-effect (E(max)) model was fitted to the relationship between bacterial density changes over 24 h and corresponding PK/PD indices. A semimechanistic PK/PD model describing the time course of bacterial growth and death was developed. The AUC/MIC ratio best explained efficacy (r(2) = 0.95) compared to the peak drug concentration (C(max))/MIC ratio (r(2) = 0.76) and time above the MIC (T>MIC) (r(2) = 0.88). Static effects and 99.9% killing were achieved at AUC/MIC values of 500 and 600, respectively. For time course analysis, the net bacterial growth rate constant, maximum bacterial density, and maximum kill rate constant were similar in SCTK and chemostat studies, but PD-0162819 was more potent in SCTK than in the chemostat (50% effective concentration [EC(50)] = 0.046 versus 0.34 μg/ml). In conclusion, basic PK/PD relationships for PD-0162819 were established using in vitro dynamic systems. Although the bacterial growth parameters and maximum drug effects were similar in SCTK and the chemostat system, PD-0162819 appeared to be more potent in SCTK, illustrating the importance of understanding the differences in preclinical models. Additional studies are needed to determine the in vivo relevance of these results.

  19. Transcriptional regulation of acetyl-CoA carboxylase α isoforms in dairy ewes during conjugated linoleic acid induced milk fat depression.

    Science.gov (United States)

    Ticiani, E; Urio, M; Ferreira, R; Harvatine, K J; De Oliveira, D E

    2016-10-01

    Feeding trans-10, cis-12 CLA to lactating ewes reduces milk fat by down-regulating expression of enzymes involved in lipid synthesis in the mammary gland and increases adipose tissue lipogenesis. Acetyl-CoA carboxylase α (ACC-α) is a key regulated enzyme in de novo fatty acid synthesis and is decreased by CLA. In the ovine, the ACC-α gene is expressed from three tissue-specific promoters (PI, PII and PIII). This study evaluated promoter-specific ACC-α expression in mammary and adipose tissue of lactating cross-bred Lacaune/Texel ewes during milk fat depression induced by rumen-unprotected trans-10, cis-12 CLA supplement. In all, 12 ewes arranged in a completely randomized design were fed during early, mid and late lactation one of the following treatments for 14 days: Control (forage+0.9 kg of concentrate on a dry matter basis) and CLA (forage+0.9 kg of concentrate+27 g/day of CLA (29.9% trans-10, cis-12)). Mammary gland and adipose tissue biopsies were taken on day 14 for gene expression analysis by real-time PCR. Milk fat yield and concentration were reduced with CLA supplementation by 27%, 21% and 35% and 28%, 26% and 42% during early, mid and late lactation, respectively. Overall, our results suggest that trans-10, cis-12 CLA down-regulates mammary ACC-α gene expression by decreasing expression from PII and PIII in mammary gland and up-regulates adipose ACC-α gene expression by increasing expression from PI.

  20. Tissue-specific expression and post-translational modifications of plant- and bacterial-type phosphoenolpyruvate carboxylase isozymes of the castor oil plant, Ricinus communis L.

    Science.gov (United States)

    O'Leary, Brendan; Fedosejevs, Eric T; Hill, Allyson T; Bettridge, James; Park, Joonho; Rao, Srinath K; Leach, Craig A; Plaxton, William C

    2011-11-01

    This study employs transcript profiling together with immunoblotting and co-immunopurification to assess the tissue-specific expression, protein:protein interactions, and post-translational modifications (PTMs) of plant- and bacterial-type phosphoenolpyruvate carboxylase (PEPC) isozymes (PTPC and BTPC, respectively) in the castor plant, Ricinus communis. Previous studies established that the Class-1 PEPC (PTPC homotetramer) of castor oil seeds (COS) is activated by phosphorylation at Ser-11 and inhibited by monoubiquitination at Lys-628 during endosperm development and germination, respectively. Elimination of photosynthate supply to developing COS by depodding caused the PTPC of the endosperm and cotyledon to be dephosphorylated, and then subsequently monoubiquitinated in vivo. PTPC monoubiquitination rather than phosphorylation is widespread throughout the castor plant and appears to be the predominant PTM of Class-1 PEPC that occurs in planta. The distinctive developmental patterns of PTPC phosphorylation versus monoubiquitination indicates that these two PTMs are mutually exclusive. By contrast, the BTPC: (i) is abundant in the inner integument, cotyledon, and endosperm of developing COS, but occurs at low levels in roots and cotyledons of germinated COS, (ii) shows a unique developmental pattern in leaves such that it is present in leaf buds and young expanding leaves, but undetectable in fully expanded leaves, and (iii) tightly interacts with co-expressed PTPC to form the novel and allosterically-desensitized Class-2 PEPC heteromeric complex. BTPC and thus Class-2 PEPC up-regulation appears to be a distinctive feature of rapidly growing and/or biosynthetically active tissues that require a large anaplerotic flux from phosphoenolpyruvate to replenish tricarboxylic acid cycle C-skeletons being withdrawn for anabolism.

  1. Recombinant thermoactive phosphoenolpyruvate carboxylase (PEPC) from Thermosynechococcus elongatus and its coupling with mesophilic/thermophilic bacterial carbonic anhydrases (CAs) for the conversion of CO2 to oxaloacetate.

    Science.gov (United States)

    Del Prete, Sonia; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T; Carginale, Vincenzo

    2016-01-15

    With the continuous increase of atmospheric CO2 in the last decades, efficient methods for carbon capture, sequestration, and utilization are urgently required. The possibility of converting CO2 into useful chemicals could be a good strategy to both decreasing the CO2 concentration and for achieving an efficient exploitation of this cheap carbon source. Recently, several single- and multi-enzyme systems for the catalytic conversion of CO2 mainly to bicarbonate have been implemented. In order to design and construct a catalytic system for the conversion of CO2 to organic molecules, we implemented an in vitro multienzyme system using mesophilic and thermophilic enzymes. The system, in fact, was constituted by a recombinant phosphoenolpyruvate carboxylase (PEPC) from the thermophilic cyanobacterium Thermosynechococcus elongatus, in combination with mesophilic/thermophilic bacterial carbonic anhydrases (CAs), for converting CO2 into oxaloacetate, a compound of potential utility in industrial processes. The catalytic procedure is in two steps: the conversion of CO2 into bicarbonate by CA, followed by the carboxylation of phosphoenolpyruvate with bicarbonate, catalyzed by PEPC, with formation of oxaloacetate (OAA). All tested CAs, belonging to α-, β-, and γ-CA classes, were able to increase OAA production compared to procedures when only PEPC was used. Interestingly, the efficiency of the CAs tested in OAA production was in good agreement with the kinetic parameters for the CO2 hydration reaction of these enzymes. This PEPC also revealed to be thermoactive and thermostable, and when coupled with the extremely thermostable CA from Sulphurhydrogenibium azorense (SazCA) the production of OAA was achieved even if the two enzymes were exposed to temperatures up to 60 °C, suggesting a possible role of the two coupled enzymes in biotechnological processes. PMID:26712095

  2. Associations of polymorphisms in the promoter I of bovine acetyl-CoA carboxylase-alpha gene with beef fatty acid composition.

    Science.gov (United States)

    Zhang, S; Knight, T J; Reecy, J M; Wheeler, T L; Shackelford, S D; Cundiff, L V; Beitz, D C

    2010-08-01

    The objectives of this study were to identify single nucleotide polymorphisms (SNPs) in the promoter I (PI) region of the bovine acetyl-CoA carboxylase-alpha (ACACA) gene and to evaluate the extent to which they were associated with lipid-related traits. Eight novel SNPs were identified, which were AJ276223:g.2064T>A (SNP1), g.2155C>T (SNP2), g.2203G>T (SNP3), g.2268T>C (SNP4), g.2274G>A (SNP5), g.2340A>G (SNP6), g.2350T>C (SNP7) and g.2370A>G (SNP8). Complete linkage disequilibrium was observed among SNP1, 2, 4, 5, 6 and 8. Phenotypic data were collected from 573 cross-bred steers with six sire breeds, including Hereford, Angus, Brangus, Beefmaster, Bonsmara and Romosinuano. The genotypes of SNP1/2/4/5/6/8 were significantly associated with adjusted backfat thickness. The genotypes of SNP3 were significantly associated with triacylglycerol (TAG) content and fatty acid composition of longissimus dorsi muscle (LM) in Brangus-, Romosinuano- and Bonsmara-sired cattle. Cattle with g.2203GG genotype had greater concentrations of TAG, total lipid, total saturated fatty acid and total monounsaturated fatty acid than did cattle with g.2203GT genotype. The genotypes of SNP7 were significantly associated with fatty acid composition of LM. Cattle with genotype g.2350TC had greater amounts of several fatty acids in LM than did cattle with genotype g.2350CC. Our results suggested that the SNPs in the PI region of ACACA gene are associated with variations in the fatty acid contents in LM. PMID:20002363

  3. Phosphorylation of bacterial-type phosphoenolpyruvate carboxylase by a Ca2+-dependent protein kinase suggests a link between Ca2+ signalling and anaplerotic pathway control in developing castor oil seeds.

    Science.gov (United States)

    Hill, Allyson T; Ying, Sheng; Plaxton, William C

    2014-02-15

    The aim of the present study was to characterize the native protein kinase [BTPC (bacterial-type phosphoenolpyruvate carboxylase)-K (BTPC Ser451 kinase)] that in vivo phosphorylates Ser451 of the BTPC subunits of an unusual Class-2 PEP (phosphoenolpyruvate) carboxylase hetero-octameric complex of developing COS (castor oil seeds). COS BTPC-K was highly purified by PEG fractionation and hydrophobic size-exclusion anion-exchange and affinity chromatographies. BTPC-K phosphorylated BTPC strictly at Ser451 (Km=1.0 μM; pH optimum=7.3), a conserved target residue occurring within an intrinsically disordered region, as well as the protein histone III-S (Km=1.7 μM), but not a COS plant-type PEP carboxylase or sucrose synthase or α-casein. Its activity was Ca2+- (K0.5=2.7 μM) and ATP- (Km=6.6 μM) dependent, and markedly inhibited by trifluoperazine, 3-phosphoglycerate and PEP, but insensitive to calmodulin or 14-3-3 proteins. BTPC-K exhibited a native molecular mass of ~63 kDa and was soluble rather than membrane-bound. Inactivation and reactivation occurred upon BTPC-K's incubation with GSSG and then DTT respectively. Ser451 phosphorylation by BTPC-K inhibited BTPC activity by ~50% when assayed under suboptimal conditions (pH 7.3, 1 mM PEP and 10 mM L-malate). Our collective results indicate a possible link between cytosolic Ca2+ signalling and anaplerotic flux control in developing COS.

  4. Characterization of acetyl-CoA and propionyl-CoA carboxylases encoded by Leptospira interrogans serovar Lai: an initial biochemical study for leptospiral gluconeogenesis via anaplerotic CO2 assimilation

    Institute of Scientific and Technical Information of China (English)

    Nanqiu Peng; Yi Zhong; Qing Zhang; Mingyue Zheng; Wei Zhao; Hualiang Jiang; Chen Yang; Xiaokui Guo; Guoping Zhao

    2012-01-01

    Leptospira interrogans is the causative agent of leptospirosis.The in vitro growth of L.interrogans requires CO2 and a partial 3-hydroxypropionate pathway involving two acyl-CoA carboxylases was suggested by genomic analysis to assimilate CO2.Either set of the candidate genes heterologously co-expressed in Escherichia coli was able to demonstrate both acetyl-CoA carboxylase (ACC)and propionyl-CoA carboxylase (PCC) activities.The trisubunit holoenzyme (LA_2736-LA_2735 and LA_3803),although failed to be purified,was designated ACC based on its substrate preference toward acetyl-CoA.The partially purified bi-subunit holoenzyme (LA_2432-LA_2433) has a considerably higher activity against propionyi-CoA as the substrate than that of acetyl-CoA,and thus,designated PCC.Native polyacrylamide gel electrophoresis indicated that this PCC has a molecular mass of around 669 kDa,suggesting an α4β4 quaternary structure and both structural homology modeling and site-directed mutagenesis analysis of its carboxyltransferase subunit (LA_2433) indicated that the A431 residue located at the bottom of the putative substrate binding pocket may play an important role in substrate specificity determination.Both transcriptomic and proteomic data indicated that enzymes involved in the suggested partial 3-hydroxypropionate pathway were expressed in vivo in addition to ACC/PCC and the homologous genes in genomes of other Leptospira species were re-annotated accordingly.However,as the in vitro detected specific activity of ACC in the crude cell extract was too low to account for the growth of the bacterium in Ellinghausen-McCulloughJohnson-Harris minimal medium,further systematic analysis is required to unveil the mechanism of gluconeogenesis via anaplerotic CO2 assimilation in Leptospira species.

  5. MEDICA 16 inhibits hepatic acetyl-CoA carboxylase and reduces plasma triacylglycerol levels in insulin-resistant JCR: LA-cp rats.

    Science.gov (United States)

    Atkinson, Laura L; Kelly, Sandra E; Russell, James C; Bar-Tana, Jacob; Lopaschuk, Gary D

    2002-05-01

    Intracellular triacylglycerol (TG) content of liver and skeletal muscle contributes to insulin resistance, and a significant correlation exists between TG content and the development of insulin resistance. Because acetyl-CoA carboxylase (ACC) is the rate-limiting enzyme for liver fatty acid biosynthesis and a key regulator of muscle fatty acid oxidation, we examined whether ACC plays a role in the accumulation of intracellular TG. We also determined the potential role of 5'-AMP-activated protein kinase (AMPK) in this process, since it can phosphorylate and inhibit ACC activity in both liver and muscle. TG content, ACC, and AMPK were examined in the liver and skeletal muscle of insulin-resistant JCR:LA-cp rats during the time frame when insulin resistance develops. At 12 weeks of age, there was a threefold elevation in liver TG content and a sevenfold elevation in skeletal muscle TG content. Hepatic ACC activity was significantly elevated in 12-week-old JCR:LA-cp rats compared with lean age-matched controls (8.75 +/- 0.53 vs. 3.30 +/- 0.18 nmol. min(-1). mg(-1), respectively), even though AMPK activity was also increased. The observed increase in hepatic ACC activity was accompanied by a 300% increase in ACC protein expression. There were no significant differences in ACC activity, ACC protein expression, or AMPK activity in the skeletal muscle of the 12-week JCR:LA-cp rats. Treatment of 12-week JCR:LA-cp rats with MEDICA 16 (an ATP-citrate lyase inhibitor) resulted in a decrease in hepatic ACC and AMPK activities, but had no effect on skeletal muscle ACC and AMPK. Our data suggest that alterations in ACC or AMPK activity in muscle do not contribute to the development of insulin resistance. However, increased liver ACC activity in the JCR:LA-cp rat appears to contribute to the development of lipid abnormalities, although this increase does not appear to occur secondary to a decrease in AMPK activity.

  6. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of CO2 marking 14C

    International Nuclear Information System (INIS)

    After a bibliografic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14CO3HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC2 from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg2 concentration and determination of the Km(s) from CO2 and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO22 and Mg2. (Author) 64 refs

  7. Small Orbits

    CERN Document Server

    Borsten, L; Ferrara, S; Marrani, A; Rubens, W

    2012-01-01

    We study both the "large" and "small" U-duality charge orbits of extremal black holes appearing in D = 5 and D = 4 Maxwell-Einstein supergravity theories with symmetric scalar manifolds. We exploit a formalism based on cubic Jordan algebras and their associated Freudenthal triple systems, in order to derive the minimal charge representatives, their stabilizers and the associated "moduli spaces". After recalling N = 8 maximal supergravity, we consider N = 2 and N = 4 theories coupled to an arbitrary number of vector multiplets, as well as N = 2 magic, STU, ST^2 and T^3 models. While the STU model may be considered as part of the general N = 2 sequence, albeit with an additional triality symmetry, the ST^2 and T^3 models demand a separate treatment, since their representative Jordan algebras are Euclidean or only admit non-zero elements of rank 3, respectively. Finally, we also consider minimally coupled N = 2, matter coupled N = 3, and "pure" N = 5 theories.

  8. Small Business Development Center

    Data.gov (United States)

    Small Business Administration — Small Business Development Centers (SBDCs) provide assistance to small businesses and aspiring entrepreneurs throughout the United States and its territories. SBDCs...

  9. Effect of the fructose 1,6-bisphosphate preconditioning in the isolated rat myocardium LVEDP MDA and SOD%FDP 预处理对离体大鼠心脏LVEDP和 MDA、SOD的影响

    Institute of Scientific and Technical Information of China (English)

    刘福林; 周玉娟; 刘春颖; 武变瑛

    2006-01-01

    目的:观察1,6-二磷酸果糖(fructose 1,6-bisphosphate,FDP)预处理对离体大鼠心肌组织MDA、SOD的变化, FDP对心肌缺血再灌注损伤的保护效果.方法:用Wistar大鼠建立Langendorff模型,实验随机分为2组,灌注液应用Krebs-Ring液和Krebs-Ring液加FDP 5mmol·L-1两组分别分成缺血前期、缺血期和再灌注期,每8只大鼠1组,共6组.进行对照组和FDP组对比,观察指标左室舒张末压(LVEDP)、心肌组织丙二醛(MDA)的含量、超氧化物歧化酶(SOD)的活性.结果:对照组大鼠缺血再灌注后LVEDP明显增高(P<0.05).MDA增高以对照组缺血期最为明显,且对照组缺血期及再灌注期与FDP组缺血期和再灌注期相比较差异显著(P<0.01、P<0.05).对照组缺血期、再灌期与缺血前期相比较差异明显(P<0.05).FDP组缺血期、再灌期与缺血前期比较无明显差异.SOD活性FDP组均较对照组增强且具有显著差异(P<0.01).结论:FDP预处理对心肌具有良好的保护效应,具有明显增加心肌组织对缺氧的耐受,减轻缺血再灌注损伤,减少脂质过氧化物-氧自由基的生成,促进心功能的恢复.

  10. Role of the Rubisco small subunit. Final report for period May 1, 1997--April 30,2000

    Energy Technology Data Exchange (ETDEWEB)

    Spreitzer, Robert J.

    2000-10-04

    CO{sub 2} and O{sub 2} are mutually competitive at the active site of ribulose-1,5-biphosphate (RuBP) carboxylase/oxygenase (Rubisco). Rubisco contains two subunits, each present in eight copies. The 15-kD small subunit is coded by a family of nuclear RbcS genes. Until now, the role of the small subunit in Rubisco structure or catalytic efficiency is not known. Because of other work in eliminating the two RbcS genes in the green algo Chlamydomonas reinhardtii, it is now possible to address questions about the structure-function relationships of the eukaryotic small subunit. There are three specific aims in this project: (1) Alanine scanning mutagenesis is being used to dissect the importance of the {beta}A/{beta}B loop, a feature unique to the eukaryotic small subunit. (2) Random mutagenesis is being used to identify additional residues or regions of the small subunit that are important for holoenzyme assembly and function. (3) Attempts are being made to express foreign small subunits in Chlamydomonas to examine the contribution of small subunits to holoenzyme assembly, catalytic efficiency, and CO{sub 2}/O{sub 2} specificity.

  11. 杜氏盐藻磷酸烯醇式丙酮酸羧化酶基因的克隆和分析%Cloning and analysis of phosphoenolpyruvate carboxylase (PEPC) gene of Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    张楠楠; 潘卫东; 崔玉琳; 秦松; 薛乐勋

    2011-01-01

    为研究杜氏盐藻(Dunaliella salina)磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxylase,PEPC)基因的功能, 根据莱茵衣藻(Chlamydomonas reinhardtii)、拟南芥(Arabidopsis thaliana)、花生(Arachis hypogaea)等真核生物PEPC 基因高度保守序列, 设计一对简并引物, 通过RT-PCR 的方法获得杜氏盐藻PEPC 基因部分序列, 然后采用RACE 的方法分别克隆到5′端和3′端序列, 拼接后得到全长cDNA, 其长度为3 523bp, 包含2 949 bp 的完整开放阅读框, 编码982 个氨基酸, 相对分子质量为110560.5。氨基酸序列与已知物种PEPC 序列的同源性依次为: Chlamydomonas reinhardtii 69%, Chlorellavariabilis 55%, Ostreococcus tauri 50%和Ostreococcus lucimarinus CCE9901 49%, 表明所克隆的序列确为杜氏盐藻PEPC cDNA 序列。%To investigate the function of phosphoenolpyruvate carboxylase (PEPC) gene of Dunaliella salina, a pair of degenerate primers was designed according to the conserved motifs of the PEPC of Chlamydomonas reinhardtii, Arabidopsis thaliana, and Arachis hypogaea. A cDNA fragment was obtained from green alga Dunaliella salina through RT-PCR, and then the full length of the cDNA was isolated by 3’ and 5’RACE. The isolated cDNA sequence was 3523 bp in length with a 2949 bp coding region that encoded 982 amino acid residues with the predicted relative molecular mass of 110560.5 dolton. In addition, homology analysis showed that PEPC of D. salina was highly similar to that of C. reinhardtii(69%), Chlorella variabilis(55%), Ostreococcus tauri(50%), and O. lucimarinus CCE9901(49%), suggesting that the cDNA isolated from Dunaliella salina was PEPC-encoding.

  12. Functions of plant phosphoenolpyruvate carboxylase and its applications for genetic engineering%植物磷酸烯醇式丙酮酸羧化酶的功能及其在基因工程中的应用

    Institute of Scientific and Technical Information of China (English)

    魏绍巍; 黎茵

    2011-01-01

    Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) is an important ubiquitous cytosol enzyme that fixes HCO3 together with phosphoenolpyruvate (PEP) and yields oxaloacetate that can be converted to intermediates of the citric acid cycle. In plant cells, PEPC participates in CO2 assimilation and other important metabolic pathways, and it has broad functions in different plant tissues. PEPC is also involved in the regulation of storage product synthesis and metabolism in seeds, such as affecting the metabolic fluxes from sugars/starch towards the synthesis of fatty acids or amino acids and proteins. In this review, we introduced the progress in classification, structure and regulation of PEPC in plant tissues. We discussed the potential applications of plant PEPCs in genetic engineering. The researches in functions and regulationmechanism of plant PEPCs will provide beneficial approaches to applications of plant PEPCs in high-yield crops breeding, energy crop and microbe genetic engineering.%植物磷酸烯醇式丙酮酸羧化酶(Phosphoenolpyruvate carboxylase,PEPC,EC 4.1.1.31)是广泛存在的一种细胞质酶,催化磷酸烯醇式丙酮酸(PEP)和HCO3-生成草酰乙酸(OAA),后者可转化生成三羧酸循环的多种中间产物.PEPC在植物细胞中参与植物的光合碳同化等重要代谢途径,并且在不同组织中具有多种生理功能.PEPC同时也参与调控植物种子的营养物质合成与代谢过程,控制糖类物质流向脂肪酸合成或蛋白质合成途径.以下介绍了植物PEPC的种类、蛋白质结构特点及其在植物组织中的调控方式,并重点论述了PEPC在生物基因工程中的应用方面的进展,随着对其功能机制和应用研究的深入,将有助于植物PEPC在高产优质农作物育种、能源植物和工业微生物等的开发利用等方面得到更好的发展与应用.

  13. Small intestinal ischemia and infarction

    Science.gov (United States)

    Intestinal necrosis; Ischemic bowel - small intestine; Dead bowel - small intestine; Dead gut - small intestine; Infarcted bowel - small intestine; Atherosclerosis - small intestine; Hardening of the arteries - small intestine

  14. Are Subject Small Clauses Really Small Clauses?

    Science.gov (United States)

    Kubo, Miori

    1993-01-01

    This paper discusses the ongoing debate over small clauses concerning the structure of the verb phrase in "I consider Bill smart." It is demonstrated that the subject constituent in question is not a small clause, but a Noun Phrase (NP), following Noun (N). It is shown that some peculiar phenomena under the small clause analysis are natural…

  15. Bioinformatic analysis on bacterial-type phosphoenolpyruate carboxylase in plants%植物细菌型磷酸烯醇式丙酮酸羧化酶基因的生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    关晶晶; 陈锦清; 汪小福

    2011-01-01

    The nucleic acid sequence and amino acid sequence of phosphoenolpyruate carboxylase (PEPC) from eleven plants such as Arabidopsis thaliana, Brassica napus, Gtycine max, Arachis hypogaea and Oryza sativa japonica,which were registered in GenBank, were analyzed and predicted by the tools of bioinformatics in the following aspects, mainly including the composition of nucleic acid sequence and amino acid sequence, physical and chemical characters, subcellular localization, hydrophobicity, structure functional domains, motifs search, tertiary structure of protein.%采用生物信息学方法对GenBank中的拟南芥、油菜、大豆、花生和水稻等11种植物细菌型磷酸烯醇式丙酮酸羧化酶(PEPC)基因的核苷酸和氨基酸序列进行了比对分析,进而对其基因结构、系统进化、理化性质、亚细胞定位、疏水性、功能结构域及蛋白质三级结构等重要参数进行了预测和分析.

  16. Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. In vivo phosphorylation of phosphoenolpyruvate carboxylase in guard cells of Vicia faba L. is enhanced by fusicoccin and suppressed by abscisic acid

    Energy Technology Data Exchange (ETDEWEB)

    Du, Z.; Aghoram, K.; Outlaw, W.H. Jr.

    1996-12-31

    Plants regulate water loss and CO{sub 2} gain by modulating the aperture sizes of stomata that penetrate the epidermis. Aperture size itself is increased by osmolyte accumulation and consequent turgor increase in the pair of guard cells that flank each stoma. Guard-cell phosphoenolpyruvate carboxylase, which catalyzes the regulated step leading to malate synthesis, is crucial for charge and pH maintenance during osmolyte accumulation. Regulation of this cytosolic enzyme by effectors is well documented, but additional regulation by posttranslational modification is predicted by the alteration of PEPC kinetics during stomatal opening. In this study, the authors have investigated whether this alteration is associated with the phosphorylation status of this enzyme. Using sonicated epidermal peels (isolated guard cells) pre-loaded with {sub 32}PO{sub 4}, the authors induced stomatal opening and guard-cell malate accumulation by incubation with 5 {micro}M fusicoccin (FC). In corroboratory experiments, guard cells were incubated with 5 {micro}M fusicoccin (FC). In corroboratory experiments, guard cells were incubated with the FC antagonist, 10 {micro}M abscisic acid (ABA). The phosphorylation status of PEPC was assessed by immunoprecipitation, electrophoresis, immunoblotting, and autoradiography. PEPC was phosphorylated when stomata were stimulated to open, and phosphorylation was lessened by incubation with ABA.

  17. N-acetylcysteine and fructose-1,6-bisphosphate: immunomodulatory effects on mononuclear cell culture N-acetilcisteína e frutose-1,6-bisfosfato: efeito imunomodulador em cultura de células mononucleares

    Directory of Open Access Journals (Sweden)

    Ricardo Obalski de Mello

    2012-04-01

    Full Text Available INTRODUCTION: Sepsis is a complex syndrome caused by an uncontrolled systemic inflammatory response. Inflammatory cytokines play a pivotal role in septic shock pathogenesis. Therapeutic strategies have been tested in order to modulate the excessive generation or function of sepsis mediators. OBJECTIVE: The objective of the present study was to investigate the therapeutic effect of N-acetylcysteine (NAC and its association with fructose-1,6-bisphosphate (FBP on T-lymphocytes proliferation, interleukin-1β (IL-1β and monocyte chemotactic protein-1 (MCP-1 levels. MATERIAL AND METHODS: Peripheral blood mononuclear cell samples were isolated from healthy individuals. T-lymphocytes were stimulated with phytohemagglutinin for 96 hours and submitted to different concentrations of NAC or NAC associated with FBP. RESULTS: NAC (10 and 15 mM and NAC (15 mM associated with FBP reduced T-lymphocytes proliferation. IL-1β levels rose in the presence of both NAC (15 mM and NAC with FBP (1.25 mM. MCP-1 levels were reduced only by NAC (15 mM associated with FBP (1.25 mM. CONCLUSION: The results suggest that both NAC itself and NAC associated with FBP inhibit cellular proliferation, acting as potent immunomodulatory agents, which corroborates its use in the treatment of inflammatory diseases.INTRODUÇÃO: A sepse é uma síndrome complexa causada pela resposta inflamatória sistêmica descontrolada. As citocinas inflamatórias representam papel central na patogênese do choque séptico. Têm sido testadas estratégias terapêuticas a fim de modular a geração ou a função excessiva de mediadores na sepse. OBJETIVO: O objetivo deste estudo foi investigar o efeito terapêutico da N-acetilcisteína (NAC e sua associação com a frutose-1,6-bisfosfato (FBP sobre a proliferação de linfócitos T e a geração de interleucina-1β (IL-1β e proteína quimiotática de monócitos 1 (MCP-1 em cultura celular. MATERIAL E MÉTODOS: Foram isoladas células mononucleares de

  18. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC ...

  19. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  20. Small Business Size Standards

    Data.gov (United States)

    Small Business Administration — Certain government programs, such as SBA loan programs and contracting opportunities, are reserved for small business concerns. In order to qualify, businesses must...

  1. AcEST: DK946100 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 6. 5' end sequence. DK946100 CL2Contig2 Show DK946100 Clone id YMU02A01NGRL0011_H06 Library YMU02 Length 574... Definition Adiantum capillus-veneris mRNA. clone: YMU02A01NGRL0011_H06. 5' end sequence. Accession DK946100...ch programs, Nucleic Acids Res. 25:3389-3402. Query= DK946100|Adiantum capillus-veneris mRNA, clone: YMU02A0...boxylase small cha... 179 7e-45 sp|P10053|RBS_PINTH Ribulose bisphosphate carboxylase small chai... 178 2e-4...FDAKRQVQVSGFLVQKPS 571 K YPE F+R++GFD KRQVQ F+ KP+ Sbjct: 146 AKKAYPEYFVRIIGFDNKR

  2. A comparative study of drug resistance mechanism associated with active site and non-active site mutations: I388N and D425G mutants of acetyl-coenzyme-A carboxylase.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Guang-Fu

    2012-03-01

    A major concern in the development of acetyl-CoA carboxylase-inhibiting (ACCase; EC 6.4.1.2) herbicides is the emergence of resistance as a result of the selection of distinct mutations within the CT domain. Mutations associated with resistance have been demonstrated to include both active sites and non-active sites, including Ile-1781-Leu, Trp- 2027-Cys, Ile-2041-Asn, Asp-2078-Gly, and Gly-2096-Ala (numbered according to the Alopecurus myosuroides plastid ACCase). In the present study, extensive computational simulations, including molecular dynamics (MD) simulations and molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) calculations, were carried out to compare the molecular mechanisms of active site mutation (I388N) and non-active site mutation (D425G) in Alopecurus myosuroides resistance to some commercial herbicides targeting ACCase, including haloxyfop (HF), diclofop (DF) and fenoxaprop (FR). All of the computational model and energetic results indicated that both I388N and D425G mutations have effects on the conformational change of the binding pocket. The π-π interaction between ligand and Phe377 and Tyr161' residues, which make an important contribution to the binding affinity, was decreased after mutation. As a result, the mutant-type ACCase has a lower affinity for the inhibitor than the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural and mechanistic insights obtained from the present study will deepen our understanding of the interactions between ACCase and herbicides, which provides a molecular basis for the future design of a promising inhibitor with low resistance risk. PMID:22242795

  3. Contribution of carbon fixed by Rubisco and PEPC to phloem export in the Crassulacean acid metabolism plant Kalanchoë daigremontiana

    OpenAIRE

    Wild, Birgit; Wanek, Wolfgang; Postl, Wolfgang; Richter, Andreas

    2010-01-01

    Crassulacean acid metabolism (CAM) plants exhibit a complex interplay between CO2 fixation by phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), and carbon demand for CAM maintenance and growth. This study investigated the flux of carbon from PEPC and direct Rubisco fixation to different leaf carbon pools and to phloem sap over the diurnal cycle. Concentrations and carbon isotope compositions of starch, soluble sugars, and organic acids were ...

  4. Small bowel resection - discharge

    Science.gov (United States)

    ... incision is red, warm, swollen, or more painful Short of breath or chest pain Swollen legs or pain in your calves Alternative Names Small intestine surgery - discharge; Bowel resection - small intestine - discharge; Resection of ...

  5. Small Intestine Disorders

    Science.gov (United States)

    Your small intestine is the longest part of your digestive system - about twenty feet long! It connects your stomach to ... many times to fit inside your abdomen. Your small intestine does most of the digesting of the foods ...

  6. Securitization and small business

    OpenAIRE

    Wilcox, James A.

    2011-01-01

    Small businesses have relied considerably on securitized markets for credit. The recent financial crisis led to a virtual cessation of securitization of some of the loans used by small businesses, such as commercial real estate mortgages, vehicle, and credit card loans. In addition, values of commercial and residential real estate, which small businesses often use as collateral for loans, dropped dramatically. As a consequence, small businesses may have experienced tighter credit conditions t...

  7. Chairing a Small Department.

    Science.gov (United States)

    Bowker, Lee H.; Lynch, David M.

    Ten management problems for chairs of small departments in small colleges are discussed, along with problem-solving strategies for these administrators. Serious disagreements within a small and intimate department may create a country club culture in which differences are smoothed over and the personal idiosyncrasies of individual members are…

  8. Small cell glioblastoma or small cell carcinoma

    DEFF Research Database (Denmark)

    Hilbrandt, Christine; Sathyadas, Sathya; Dahlrot, Rikke H;

    2013-01-01

    was admitted to the hospital with left-sided loss of motor function. A MRI revealed a 6 cm tumor in the right temporoparietal area. The histology was consistent with both glioblastoma multiforme (GBM) and small cell lung carcinoma (SCLC) but IHC was suggestive of a SCLC metastasis. PET-CT revealed...

  9. Influence of the nitrate concentration and source in the incorporation of 14{sub C}O2 by the RuBP-carboxylase from wheat (triticum aestivum) and maize (zea mays); Influencia de la concentracion y fuente de nitrogeno en la incorporacion de 14{sub C}O2 por la RuBp-carboxilasa de trigo (triticum aewtivum) y maiz (zea mays)

    Energy Technology Data Exchange (ETDEWEB)

    Saez Angulo, R. M.; Gines Diaz, M. J.; Garcia Pineda, M. D.

    1982-07-01

    The effect of the concentration and source of nitrogen in the culture media has been studied regarding its influence in the activity of the RuBP-carboxylase from wheat and maize during the first month of development. Wheat and maize has been chosen as plants representatives of two different types of CO{sub 2} assimilation: C3 and M- respectively. Plants have been grown in hydroponic media and under temperature, humidity and nutrient salts control. A negative effect of NH{sub 4} has been observed in the enzymatic activity of wheat seedlings, being this effect more remarkable as NH{sub 4} concentration increases and as long the time of treatment. In our experimental conditions the most favorable source of nitrogen has been N0{sub 3}NH{sub 4}. The specific activity of the enzyme from wheat is about four times higher than in maize, even it decreases with time. This decreasing has not been observed in maize, with the exception of total absence of nitrogen in the media. We have not seen significant differences between the two photo periods which have been tested. Also, no differences have been found in the enzyme activities at the different NO{sub 3}NH{sub 4} concentrations assayed, and it seems that RuBP-carboxylase metabolism is only affected in the case of absolute stress. (Author) 20 refs.

  10. Small Schools, Big Future

    Science.gov (United States)

    Halsey, R. John

    2011-01-01

    Historically, small schools have played a very important role in the provision of schooling in Australia. Numerically, using an enrollment of 200 or less, small schools represent approximately 45% of the schools in Australia. Population growth and the consequences of this, in particular for food production, water and energy, mean that the…

  11. Development of Small Company

    OpenAIRE

    Fiedler, Viktor

    2015-01-01

    The subject of bachelor thesis is analysis of possibilities and directions of the development of small company. It describes the structure of small company and the problems of its development. It analyses present economical, financial and business situation inside and outside the company. In the second part author introduces some proposals for improving several parts of company.

  12. Small Group Inquiry.

    Science.gov (United States)

    Koller, Martin M.

    Learning in small groups is a practical way to bring about behavior change. The inquiry learning process is perceived to be the most natural and scientific way of learning. Skills developed include those of problem-solving task analysis, decision-making, value formation and adaptability. The art of small group interaction is developed. Factual…

  13. Small States in Europe

    DEFF Research Database (Denmark)

    This book offers an accessible, coherent and informative analysis of contemporary and future foreign policy challenges facing small states in Europe.......This book offers an accessible, coherent and informative analysis of contemporary and future foreign policy challenges facing small states in Europe....

  14. Regulation of methanol oxidation and carbon dioxide fixation in Xanthobacter strain 25a grown in continuous culture

    NARCIS (Netherlands)

    Croes, L.M.; Meijer, Wilhelmus; Dijkhuizen, L.

    1991-01-01

    The regulation of C1-metabolism in Xanthobacter strain 25a was studied during growth of the organism on acetate, formate and methanol in chemostat cultures. No activity of methanol dehydrogenase (MDH), formate dehydrogenase (FDS) or ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisC/O) could be

  15. Recycling carbon dioxide during xylose fermentation by engineered Saccharomyces cerevisiae

    Science.gov (United States)

    In this study, we introduced the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and phosphoribulokinase (PRK) into an engineered S. cerevisiae (SR8) harboring the XR/XDH pathway and up-regulated PPP 10, to enable CO2 recycling through a synthetic rPPP during xylose fermentation (Fig. 1). ...

  16. Studies on Dasyaceae. 3. Towards a phylogeny of the Dasyaceae (Ceramiales, Rhodophyta), based on comparative rbcL gene sequences and morphology

    NARCIS (Netherlands)

    de Jong, Y.S D M; van der Wurff, A.W G; Stam, W.T.; Olsen, J.L.

    1998-01-01

    Phylogenetic analyses of the Dasyaceae based on sequence analysis of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) and 42 morphological characters are presented. Comparative sequence analysis confirms the general view of the Ceramiaceae as a primitive, paraphyletic grou

  17. A novel expression cassette for the efficient visual selection of transformed tissues in florists' chrysanthemum (Chrysanthemum morifolium Ramat.).

    NARCIS (Netherlands)

    Mao, J.; Stoopen, G.M.; Jongsma, M.A.; Wang, C.Y.

    2011-01-01

    Constructs carrying visual reporter genes coupled with efficient promoters could facilitate the process of identification and selection of stable transformants in recalcitrant crops. Here, a novel construct utilizing a ribulose-1,5-bisphosphate carboxylase (RbcS) promoter combined with the green flu

  18. Wind: small is beautiful

    International Nuclear Information System (INIS)

    The small wind sector (0.5-100 kW) is often overlooked but could provide decentralised energy systems. Small wind turbines have been used for homes, farms and small businesses for over 80 years (e.g. in the USA and the Netherlands), receiving a boost in the 1970s and 1980s following the 1973 oil crisis when a new generation of turbines entered the European and US markets. Bergey Windpower and Southwest Windpower from the USA are the market leaders in this sector in terms of sales volume but are still classed as medium-sized enterprises. Small turbines have the disadvantage of higher costs compared with large turbines due to higher manufacturing costs, technical factors associated with the tendency to use small turbines on relatively short towers, small production runs and a failure to keep up with the latest design developments such as cost-effective state-of-the-art frequency converters. Most small turbines are horizontal axis turbines, though vertical axis turbines are produced by some manufacturers. Examples of the systems available from European suppliers are described

  19. Wind: small is beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Vries, E. de

    2005-10-01

    The small wind sector (0.5-100 kW) is often overlooked but could provide decentralised energy systems. Small wind turbines have been used for homes, farms and small businesses for over 80 years (e.g. in the USA and the Netherlands), receiving a boost in the 1970s and 1980s following the 1973 oil crisis when a new generation of turbines entered the European and US markets. Bergey Windpower and Southwest Windpower from the USA are the market leaders in this sector in terms of sales volume but are still classed as medium-sized enterprises. Small turbines have the disadvantage of higher costs compared with large turbines due to higher manufacturing costs, technical factors associated with the tendency to use small turbines on relatively short towers, small production runs and a failure to keep up with the latest design developments such as cost-effective state-of-the-art frequency converters. Most small turbines are horizontal axis turbines, though vertical axis turbines are produced by some manufacturers. Examples of the systems available from European suppliers are described.

  20. Small - Display Cartography

    DEFF Research Database (Denmark)

    Nissen, Flemming; Hvas, Anders; Münster-Swendsen, Jørgen;

    This report comprises the work carried out in the work-package of small display cartography. The work-package has aimed at creating a general framework for the small-display cartography. A solid framework facilitates an increased use of spatial data in mobile devices - thus enabling, together...... Service Communication and finally, Part IV: Concluding remarks and topics for further research on small-display cartography. Part II includes a separate Appendix D consisting of a cartographic design specification. Part III includes a separate Appendix C consisting of a schema specification, a separate...

  1. Small scale optics

    CERN Document Server

    Yupapin, Preecha

    2013-01-01

    The behavior of light in small scale optics or nano/micro optical devices has shown promising results, which can be used for basic and applied research, especially in nanoelectronics. Small Scale Optics presents the use of optical nonlinear behaviors for spins, antennae, and whispering gallery modes within micro/nano devices and circuits, which can be used in many applications. This book proposes a new design for a small scale optical device-a microring resonator device. Most chapters are based on the proposed device, which uses a configuration know as a PANDA ring resonator. Analytical and nu

  2. Small satellites - An overview

    Science.gov (United States)

    Ward, A. K.

    The present review of small satellites examines spacecraft activities in the U.K. and compiles a checklist of advantages and applications for the class. These advantages are illustrated with references to recent small satellite missions and technologies developed to facilitate such launches and projects. Specific programs examined include AMPTE-UKS, Viking, and the UoSAT program, and information is given regarding the Small Explorer program, the RAE Space Technology Research Vehicle, the AEA Argos Program, and space research programs in both Japan and India. Low-cost launches are shown to be available in the form of the Ariane Structure for Auxiliary Payloads, the Pegasus and Delta vehicles, and with the Shuttle Free-flying Getaway Special. Small-satellite technologies that play key roles in their effective implementation are: structure/thermal advances, attitude control systems, on-board communications, and power and data-handling systems.

  3. Small intestine (image)

    Science.gov (United States)

    The small intestine is the portion of the digestive system most responsible for absorption of nutrients from food into the bloodstream. The pyloric sphincter governs the passage of partly digested food ...

  4. Small Mammal Trapping 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Small mammal traps were placed in the Baring division and in the Edmunds division of Moosehom National Wildlife Refuge. There were a total of 98 traps set for up to...

  5. Small bowel bacterial overgrowth

    Science.gov (United States)

    ... Surgical procedures that create a loop of small intestine where excess bacteria can grow. An example is a Billroth II type of stomach removal ( gastrectomy ). Some cases of irritable bowel syndrome (IBS) Symptoms The most common symptoms are: Abdominal ...

  6. Small & Large Intestine

    Science.gov (United States)

    ... the large intestine produces no digestive enzymes. Chemical digestion is completed in the small intestine before the chyme reaches the large intestine. Functions of the large intestine include the absorption of water and electrolytes and the elimination of ...

  7. Small bowel resection

    Science.gov (United States)

    ... reconnect, your surgeon makes an opening called a stoma through the skin of your belly. The small ... of your belly. Stool will go through the stoma into a drainage bag outside your body. This ...

  8. Small Satellite Transporter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective is to determine whether this small satellite transporter is capable of transporting at least four 6U CubeSats is possible for a given set of...

  9. Small test SDHW systems

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different.......Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different....

  10. Research using small tokamaks

    International Nuclear Information System (INIS)

    These proceedings of the IAEA-sponsored meeting held in Nice, France 10-11 October, 1988, contain the manuscripts of the 21 reports dealing with research using small tokamaks. The purpose of this meeting was to highlight some of the achievements of small tokamaks and alternative magnetic confinement concepts and assess the suitability of starting new programs, particularly in developing countries. Papers presented were either review papers, or were detailed descriptions of particular experiments or concepts. Refs, figs and tabs

  11. SMALL SCALE MORPHODYNAMICAL MODELLING

    Institute of Scientific and Technical Information of China (English)

    D. Ditschke; O. Gothel; H. Weilbeer

    2001-01-01

    Long term morphological simulations using complete coupled models lead to very time consuming computations. Latteux (1995) presented modelling techniques developed for tidal current situations in order to reduce the computational effort. In this paper the applicability of such methods to small scale problems is investigated. It is pointed out that these methods can be transferred to small scale problems using the periodicity of the vortex shedding process.

  12. Small wind turbine

    OpenAIRE

    Vélez Castellano, Didier

    2010-01-01

    The main objective is to develop a project on installing a small wind turbine at the University of Glyndwr in Wrexham Wales. Today are immersed in a world seeking clean energy for reduce greenhouse gases because this problem is becoming a global reality. So installing a small wind turbine at the university would provide large quantity of clean energy to supply a workshop and also reduce the expulsion of CO2 into the atmosphere. The main characteristic of the turbine under...

  13. UNDERSTANDING SMALL BUSINESS SCAMS

    OpenAIRE

    Michael T. Schaper; PAUL WEBER

    2012-01-01

    This paper provides an overview of the current state of knowledge about small business scams. A scam is a form of dishonest action, based upon an invitation to participate in an activity. Victims are encouraged, mislead or induced to voluntarily interact with the perpetrator, and ultimately to willingly surrender over money, information or other valuable resources. Common forms of scams directed towards small business include phishing, false business valuations and sales, fake overpayments, f...

  14. Gas Quenching Small Components

    Institute of Scientific and Technical Information of China (English)

    Paul Stratton

    2004-01-01

    Gas quenching is an environmentally friendly and effective way of quenching components. However it has not been possible to apply it to small components because of the difficulties of jigging. A method of gas quenching such small components is described in which they are levitated in a confined gas stream. The method is suitable for quenching low alloy steel components that weigh between 1 and 10g.

  15. Small-x physics

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, A.H. [Columbia Univ., New York, NY (United States). Dept. of Physics

    1997-06-01

    After a brief review of the kinematics of deep inelastic lepton-proton scattering, the parton model is described. Small-x behavior coming from DGLAP evolution and from BFKL evolution is discussed, and the two types of evolution are contrasted and compared. Then a more detailed discussion of BFKL dynamics is given. The phenomenology of small-x physics is discussed with an emphasis on ways in which BFKL dynamics may be discussed and measured. 45 refs., 12 figs.

  16. Small dams in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Grapel, C.K. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada); Mitchelmore, P. [Mitchelmore Engineering Co. Ltd., Halifax, NS (Canada)

    2009-07-01

    Small dams are often used for irrigation, municipal water supplies and storm water management. Small dams outnumber large hydro-electric projects in Canada by a wide margin, and tend to be located closer to large population centres. Despite their lower profile with the general public, small dams frequently have high consequence classifications. This study discussed the distribution of various consequence classifications for small dams of varying heights. Databases from different Canadian provinces were used to develop sets of statistics on dam features, the distribution of risk, and other relevant information. Approximately 6000 dams were classified in the database. Of these, 444 were greater than 15 metres in height. A significant portion of with high consequence classifications qualified as small dams, and the majority of the high consequence dams were under 10 metres in height. The largest population of dam owners have limited resources available for adequate engineering design, construction supervision, and dam safety management programs. It was concluded that economical methods of estimating probable maximum flood (PMF) rates are needed for small dams. 8 refs., 5 tabs., 2 figs.

  17. How Small are Small Stars Really?

    Science.gov (United States)

    2002-11-01

    VLT Interferometer Measures the Size of Proxima Centauri and Other Nearby Stars [1] Summary At a distance of only 4.2 light-years, Proxima Centauri is the nearest star to the Sun currently known [2]. It is visible as an 11-magnitude object in the southern constellation of Centaurus and is the faintest member of a triple system, together with Alpha Centauri , the brightest (double) star in this constellation. Proxima Centauri is a very-low-mass star, in fact barely massive enough to burn hydrogen to helium in its interior. It is about seven times smaller than the Sun, and the surface temperature is "only" about 3000 degrees, about half of that of our own star. Consequently, it is also much fainter - the intrinsic brightness is only 1/150th of that of our Sun. Low-mass stars are very interesting objects , also because the physical conditions in their interiors have much in common with those of giant planets, like Jupiter in our solar system. A determination of the sizes of the smallest stars has been impossible until now because of their general faintness and lack of adequate instrumentation. However, astronomers have long been keen to move forward in this direction, since such measurements would provide indirect, crucial information about the behaviour of matter under extreme conditions. When the first observations with the VLT Interferometer (VLTI), combining the light from two of the 8.2-m VLT Unit Telescopes (ANTU and MELIPAL), were made one year ago ( ESO PR 23/01 ), interferometric measurements were also obtained of Proxima Centauri . They formed part of the VLTI commissioning and the data were soon released to the ESO community, cf. the special website. Now, an international team of astronomers from Switzerland, France and ESO/Chile has successfully analysed these observations by means of newly developed, advanced software. For the first time ever, they obtained a highly accurate measurement of the size of such a small star . Three other small stars were also

  18. MINERVA: Small Planets from Small Telescopes

    Science.gov (United States)

    Wittenmyer, Robert A.; Johnson, John Asher; Wright, Jason; McCrady, Nate; Swift, Jonathan; Bottom, Michael; Plavchan, Peter; Riddle, Reed; Muirhead, Philip S.; Herzig, Erich; Myles, Justin; Blake, Cullen H.; Eastman, Jason; Beatty, Thomas G.; Lin, Brian; Zhao, Ming; Gardner, Paul; Falco, Emilio; Criswell, Stephen; Nava, Chantanelle; Robinson, Connor; Hedrick, Richard; Ivarsen, Kevin; Hjelstrom, Annie; Vera, Jon De; Szentgyorgyi, Andrew

    2015-09-01

    The Kepler mission has shown that small planets are extremely common. It is likely that nearly every star in the sky hosts at least one rocky planet. We just need to look hard enough-but this requires vast amounts of telescope time. MINERVA (MINiature Exoplanet Radial Velocity Array) is a dedicated exoplanet observatory with the primary goal of discovering rocky, Earth-like planets orbiting in the habitable zone of bright, nearby stars. The MINERVA team is a collaboration among UNSW Australia, Harvard-Smithsonian Center for Astrophysics, Penn State University, University of Montana, and the California Institute of Technology. The four-telescope MINERVA array will be sited at the F.L. Whipple Observatory on Mt Hopkins in Arizona, USA. Full science operations will begin in mid-2015 with all four telescopes and a stabilised spectrograph capable of high-precision Doppler velocity measurements. We will observe ~100 of the nearest, brightest, Sun-like stars every night for at least five years. Detailed simulations of the target list and survey strategy lead us to expect new low-mass planets.

  19. Small Animal Retinal Imaging

    Science.gov (United States)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  20. Small hydroelectric engineering practice

    CERN Document Server

    Leyland, Bryan

    2014-01-01

    Small Hydroelectric Engineering Practice is a comprehensive reference book covering all aspects of identifying, building, and operating hydroelectric schemes between 500 kW and 50 MW. In this range of outputs there are many options for all aspects of the scheme and it is very important that the best options are chosen.As small hydroelectric schemes are usually built against a limited budget it is extremely important that the concept design is optimum and every component is designed to maximise the benefi t and minimise the cost. As operating costs are often a high proportion of the income it i

  1. Small is beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Woof, M.; Casteel, K.

    1997-12-01

    While safety standards in modern mechanised underground coal mines in Britain are good, so are standards in their smaller competitors using much older equipment. Working practices and conditions at several Federation of Independent Mines (FIM) operations are described, detailing the use of equipment and methods that would be considered obsolete in larger mines. Although these mines are small the high quality of the coal that they mine means that they are economic. Drilling equipment used in small mines, and scoops are also described. 7 photos. 1 tab.

  2. Beech trees exposed to high CO{sub 2} and to simulated summer ozone levels: Effects on photosynthesis, chloroplast components and leaf enzyme activity

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, C. [Univ. of Innsbruck, Inst. of Botany, Innsbruck (Austria); Anegg, S. [GFS. National Research Centre for Environment and Health, Inst. of Biochemical Plant Pathology, Oberschleissheim (Germany); Gerant, D.; Dizengremel, P. [Univ. Henri Poincare Nancy 1, Lab. de Biologie Forestiere, Vandauvre les Nancy cedex (France); Alaoui-Sosse, B. [Lab. de Biologie et Ecophysiologie, Besancon cedex (France)

    2000-07-01

    Young trees of European beech (Fagus sylvatica L.) were exposed in a phytotron to different levels of ozone and CO{sub 2} under the climatic simulation of one vegetation period. High ozone levels were simulated similar to high ozone concentration in the field (up to 110 ppb), while CO{sub 2} was added as 300 ppm to the present level of ca 380 ppm. Our study describes different aspects of photosynthesis from the leaf level to the reactions of selected thylakoid components at different harvest times during growth of the beech trees under the different fumigation regimes. Ozone effects appeared in the first weeks of the treatment as a stimulation of chlorophyll fluorescence (F{sub v}/F{sub m}), in oxygen production and in ribulose-1,5-bisphosphate carboxylase/oxygenase activity, while the summer and early autumn harvests showed strong reductions in these parameters. Only phosphoenolpyruvate carboxylase (PEPcase) activity remained higher under high ozone. The effects of high CO{sub 2} appeared in general as a small stimulation in enzyme activity like PEPcase in spring. However, with increasing time of fumigation, reductions of all parameters were observed. Especially chlorophylls showed strong reductions under high CO{sub 2}. The combined treatment with high ozone plus high CO{sub 2} resulted mostly in an amelioration of the negative ozone effects, although control levels were not reached. (au)

  3. Small Public Library Management

    Science.gov (United States)

    Pearlmutter, Jane; Nelson, Paul

    2012-01-01

    Anyone at the helm of a small public library knows that every little detail counts. But juggling the responsibilities that are part and parcel of the job is far from easy. Finally, here's a handbook that includes everything administrators need to keep a handle on library operations, freeing them up to streamline and improve how the organization…

  4. Small public private partnerships

    DEFF Research Database (Denmark)

    Koch, Christian; Jensen, Jesper Ole

    2009-01-01

    Public Private Partnerships (PPP) are frequently mobilized as a purchasing form suitable for large infrastructure projects. And it is commonly assumed that transaction costs linked to the establishment of PPP make them prohibitive in small sizes. In a Danish context this has been safeguarded...

  5. Rolling at small scales

    DEFF Research Database (Denmark)

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well...

  6. Libraries for Small Museums.

    Science.gov (United States)

    Anderson, Linda M.

    Presented are the very basic requirements for establishing a small special library operating under a limited budget. Physical plant organization, cataloging, book processing, circulation procedures, book selection and ordering and instructions for typists are covered. Although the practices discussed were established for a museum library, what is…

  7. Deburring small intersecting holes

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1980-08-01

    Deburring intersecting holes is one of the most difficult deburring tasks faced by many industries. Only 14 of the 37 major deburring processes are applicable to most intersecting hole applications. Only five of these are normally applicable to small or miniature holes. Basic process capabilities and techniques used as a function of hole sizes and intersection depths are summarized.

  8. Small hydrogen liquefier

    International Nuclear Information System (INIS)

    In this work the deign and construction of a small hydrogen liquefier (two liters per hour maximum production) is described. The isenthalpic expansion process is used, because its construction is simple and it is generally cheaper to operate. A comparison with other liquefier processes, and considerations about their basic theory are also presented. (author)

  9. Small and Magical

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Ant genome study offers promising evidence in medical and anti-aging research While children often love observing ants happily for hours, grownups are more likely to ignore these small creatures. Some scientists, however, show greater interest in ants than children do.

  10. Small can be beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Albrand, Solveig (Institut des Sciences Nucleaires, IN2P3-CNRS/Universite Joseph Fourier, 53, avenue des Martyrs, 38026, Grenoble Cedex (France)); Ravel, J.C. (Institut des Sciences Nucleaires, IN2P3-CNRS/Universite Joseph Fourier, 53, avenue des Martyrs, 38026, Grenoble Cedex (France))

    1994-12-15

    Small laboratories with limited financial means can use low-cost personal computers for many control applications. Examples of control systems developed at SARA are discussed, illustrating the evolution of the system in step with that of the PC, but each time with a considerable re-use of software. ((orig.))

  11. Small is beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Hindley, M.

    1994-09-01

    This article focusses on small hydroelectric power development in Finland. Legislative and financial incentives, and use of standard tubular turbines are discussed. The Vuotos reservoir project is described, and the preparation of an environmental assessment of the project is noted. (UK)

  12. Research using small tokamaks

    International Nuclear Information System (INIS)

    This document consists of a collection of papers presented at the IAEA Technical Committee Meeting on Research Using Small Tokamaks. It contains 22 papers on a wide variety of research aspects, including diagnostics, design, transport, equilibrium, stability, and confinement. Some of these papers are devoted to other concepts (stellarators, compact tori). Refs, figs and tabs

  13. Small is Beatiful

    DEFF Research Database (Denmark)

    Hansen, Henrik Aldershaab Boje; Pleman, Allan; Koch, Christian

    1999-01-01

    The life and death of a small Danish software house developing ERP-software in collaboration with costumers is analysed.User producer relationships are central drivers in the company's history. This reactive development strategy creates a niche at the marketplace but produces internal...

  14. Small Windmills in Denmark

    DEFF Research Database (Denmark)

    Petersen, H.

    1980-01-01

    The report describes a project for small windmills funded by the Ministry of Energy. The test plant is described and a survey of Danish windmills is presented. Some requirements for windmills are mentioned and regulations governing the interface between grid-connected windmills and the electric...

  15. Imaging the small bowel.

    LENUS (Irish Health Repository)

    Murphy, Kevin P

    2014-03-01

    Radiologic investigations continue to play a pivotal role in the diagnosis of pathologic conditions of the small intestine despite enhancement of capsule endoscopy and double-balloon endoscopy. Imaging techniques continue to evolve and new techniques in MRI in particular, are being developed.

  16. Small Engine & Accessory Test Area

    Data.gov (United States)

    Federal Laboratory Consortium — The Small Engine and Accessories Test Area (SEATA) facilitates testaircraft starting and auxiliary power systems, small engines and accessories. The SEATA consists...

  17. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  18. Small steps for hydro

    Energy Technology Data Exchange (ETDEWEB)

    Wicke, Peter [SOWIWAS GmbH, Managua (Nicaragua)

    1998-04-01

    The government in Peru has decided to utilise its gas reserves and restrict hydro to relatively small schemes. A number of reasons for the decision are given. In 1997, the Shell-Mobile-Bechtel-COSAPI consortium was formed and agreements were signed regarding exploiting Gas de Camisea. The country's energy needs to 2010 are being assessed. It is likely that by 2001 the whole of south Peru will be receiving gas from Camisea. The Peru situation is discussed under the headings of (i) existing capacity, (ii) growing demands, (iii) a history of hydro in Peru, (iv) electrification and SHP and (v) outlook. The future for Peru's electric energy development is bright. While most of its new power capacity will come from natural gas, the small hydros also have a part to play. A stronger commitment of national and regional political authorities to consider supplies outside the big cities is said to be needed. (UK)

  19. Small steps for hydro

    International Nuclear Information System (INIS)

    The government in Peru has decided to utilise its gas reserves and restrict hydro to relatively small schemes. A number of reasons for the decision are given. In 1997, the Shell-Mobile-Bechtel-COSAPI consortium was formed and agreements were signed regarding exploiting Gas de Camisea. The country's energy needs to 2010 are being assessed. It is likely that by 2001 the whole of south Peru will be receiving gas from Camisea. The Peru situation is discussed under the headings of (i) existing capacity, (ii) growing demands, (iii) a history of hydro in Peru, (iv) electrification and SHP and (v) outlook. The future for Peru's electric energy development is bright. While most of its new power capacity will come from natural gas, the small hydros also have a part to play. A stronger commitment of national and regional political authorities to consider supplies outside the big cities is said to be needed. (UK)

  20. Small Business Innovations (MISER)

    Science.gov (United States)

    1991-01-01

    Lightwave Electronics Corporation, Mountain View, CA, developed the Series 120 and 122 non-planner diode pumped ring lasers based on a low noise ring laser with voltage tuning that they delivered to Jet Propulsion Laboratory under a Small Business Innovation Research (SBIR) contract. The voltage tuning feature allows "phase-locking" the lasers, making them "electronic," similar to radio and microwave electronic oscillators. The Series 120 and 122 can be applied to fiber sensing, coherent communications and laser radar.

  1. Small Business Innovations (Photodetector)

    Science.gov (United States)

    1991-01-01

    Epitaxx, Inc. of Princeton, NJ, developed the Epitaxx Near Infrared Room Temperature Indium-Gallium-Arsenide (InGaAs) Photodetector based on their Goddard Space Flight Center Small Business Innovation Research (SBIR) contract work to develop a linear detector array for satellite imaging applications using InGaAs alloys that didn't need to be cooled to (difficult and expensive) cryogenic temperatures. The photodetectors can be used for remote sensing, fiber optic and laser position-sensing applications.

  2. Think Small Go Big

    Institute of Scientific and Technical Information of China (English)

    汤维维

    2006-01-01

    Vepoo公司在创立之前,经历了三次创业转型。用他们的话来说,从“think big go small”转到“think small go big”用了一年的时间。这期间他们耗尽了初期筹备资金,幸运的是在最后一刻迎来了黎明的曙光。

  3. Small Cell City

    OpenAIRE

    Dehghan, S.; Steele, R.

    1997-01-01

    Traditionally, mobile operators have planned their networks to accommodate mobile terminals at ground level. Increasingly, mobile users communicate while stationary from within high-rise buildings. With mobiles operating at a variety of different heights and mobilities, plus the requirement to accommodate increasing teletraffic and multimedia services, there is a need to compact small cells into the three-dimensional city space. This article is concerned with using city buildings to act as el...

  4. Small Animal Bone Biomechanics

    OpenAIRE

    Vashishth, Deepak

    2008-01-01

    Animal models, in particular mice, offer the possibility of naturally achieving or genetically engineering a skeletal phenotype associated with disease and conducting destructive fracture tests on bone to determine the resulting change in bone’s mechanical properties. Several recent developments, including nano- and micro- indentation testing, microtensile and microcompressive testing, and bending tests on notched whole bone specimens, offer the possibility to mechanically probe small animal ...

  5. Small and Magical

    Institute of Scientific and Technical Information of China (English)

    TANG YUANKAI

    2011-01-01

    While children often love observing ants happily for hours,grown-ups are more likely to ignore these small creatures.Some scientists,however,show greater interest in ants than children do.One of them is Zhang Guojie,Associate Director of the Bioinformatics Center and Leader of Genome Projects in BGI.BG1 is China's largest genome and bioinformatics analysis center in Shenzhen,in south China's Guangdong Province.

  6. Leadership in Small Societies

    OpenAIRE

    Stephen Younger

    2010-01-01

    Multi-agent simulation was used to study several styles of leadership in small societies. Populations of 50 and100 agents inhabited a bounded landscape containing a fixed number of food sources. Agents moved about the landscape in search of food, mated, produced offspring, and died either of hunger or at a predetermined maximum age. Leadership models focused on the collection and redistribution of food. The simulations suggest that individual households were more effective at meeting their ne...

  7. When small is beautiful. Boom time for small hydro?

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, John

    2002-08-01

    Although small hydropower projects generally contribute a small proportion of most nations' electricity needs their importance often exceeds their size. The author, a freelance industrial journalist considers prospects for small hydro, how such schemes are benefiting communities throughout the world and why some countries are more successfully using small hydro than others. (Author)

  8. The small library manager's handbook

    CERN Document Server

    Graves, Alice

    2014-01-01

    The Small Library Manager's Handbook is for librarians working in all types of small libraries. It covers the everyday nuts-and-bolts operations that all librarians must perform. This handbook, written by experts who are small librarians themselves, will help all small librarians to do multiple jobs at the same time.

  9. Ecology in Small Aquatic Ecosystems

    DEFF Research Database (Denmark)

    Andersen, Mikkel René

    Small ecosystems are many-fold more abundant than their larger counterparts. Both on regional and global scale small lakes outnumber medium and large lakes and account for a much larger surface area. Small streams are also far more common than rivers. Despite their abundance small ecosystems are ...

  10. Business Small company

    OpenAIRE

    KREJČOVÁ, Kateřina

    2011-01-01

    This diploma work deals with a Business Small company. The work moves on the concrete company, which is analyzed and on the basis of analyses the new strategy is formulated. At the theoretical part, summary of solving problems is introduced. It’s needed for the analytic part of work. At the beginning, business is defined in economic terms. Found in this part are basic concepts that are linked to business. From the general definition of business the work fluently proceeds to more concrete...

  11. Small changes for works

    Institute of Scientific and Technical Information of China (English)

    Jiarui Wu

    2011-01-01

    The central dogma of molecular biology indicates that genetic information from DNA is transmitted to RNA,and then translated into proteins that play various roles during all physiological and pathological processes.However,most of the proteins have to make small chemical changes on their amino acid chains,so-called post-translational modifications,before they start to work.The collection of four articles in this issue presents timely developments in the area of protein modifications,ranging from how proteins carry out their biological functions based on protein modifications to what are molecular mechanisms of protein modifications.

  12. Small Business Innovations

    Science.gov (United States)

    1995-01-01

    The PER-Force Handcontroller was originally developed for the International Space Station under a Johnson Space Center Small Business Innovation Research (SBIR) contract. Produced by Cybernet Systems Corporation, the unit is a force-reflecting system that manipulates robots or objects by "feel." The Handcontroller moves in six degrees of freedom, with real and virtual reality forces simulated by a 3-D molecular modeling software package. It is used in molecular modeling in metallurgy applications, satellite docking research, and in research on military unmanned ground vehicles.

  13. Small Business Innovations (Cryostat)

    Science.gov (United States)

    1991-01-01

    General Pneumatics Corporation, Scottsdale, AZ, developed an anti- clogging cryostat that liquifies gases by expansion for high pressure through a nozzle to produce cryorefrigeration based on their Kennedy Space Center Small Business Innovation Research (SBIR) work to develop a Joule-Thomson (JT) expansion valve that is less susceptible to clogging by particles or condensed contaminants in the flow than a non-contaminating compressor in a closed cycle Linde-Hampson cryocooler used to generate cryogenic cooling for infrared sensors, super conductors, supercooled electronics and cryosurgery.

  14. Small Business Innovations (Helicopters)

    Science.gov (United States)

    1992-01-01

    The amount of engine power required for a helicopter to hover is an important, but difficult, consideration in helicopter design. The EHPIC program model produces converged, freely distorted wake geometries that generate accurate analysis of wake-induced downwash, allowing good predictions of rotor thrust and power requirements. Continuum Dynamics, Inc., the Small Business Innovation Research (SBIR) company that developed EHPIC, also produces RotorCRAFT, a program for analysis of aerodynamic loading of helicopter blades in forward flight. Both helicopter codes have been licensed to commercial manufacturers.

  15. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  16. Rapid small lot manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, R.W.

    1998-05-09

    The direct connection of information, captured in forms such as CAD databases, to the factory floor is enabling a revolution in manufacturing. Rapid response to very dynamic market conditions is becoming the norm rather than the exception. In order to provide economical rapid fabrication of small numbers of variable products, one must design with manufacturing constraints in mind. In addition, flexible manufacturing systems must be programmed automatically to reduce the time for product change over in the factory and eliminate human errors. Sensor based machine control is needed to adapt idealized, model based machine programs to uncontrolled variables such as the condition of raw materials and fabrication tolerances.

  17. Securitization of Small Business Loans

    OpenAIRE

    Beshouri, Christopher P.; Peter J. Nigro

    1995-01-01

    This paper assesses the potential impact of securitization in improving small businesses’ access to credit. It begins by examining the nature of small business lending and the factors that make banks the primary providers of credit to small businesses. The paper then examines the conditions under which the benefits of securitization are fully realized and whether the nature of small business lend­ing satisfies those conditions. We argue that certain characteristics of small firm finance, espe...

  18. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya, E-mail: jyli@mail.shcnc.ac.cn; Nan, Fa-Jun, E-mail: fjnan@mail.shcnc.ac.cn; Li, Jia, E-mail: jli@mail.shcnc.ac.cn

    2013-12-01

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome.

  19. Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

    International Nuclear Information System (INIS)

    AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome

  20. Measurement of 2-carboxyarabinitol 1-phosphate in plant leaves by isotope dilution. [Spinacea oleracea; Triticum aestivum; Arabidopsis thaliana; Maize; Phaseolus vulgaris; Petunia hybrida

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.D.; Kobza, J.; Seemann, J.R. (Univ. of Nevada, Reno (United States))

    1991-05-01

    The level of 2-carboxyarabinitol 1-phosphate (CA1P) in leaves of 12 species was determined by an isotope dilution assay. {sup 14}C-labeled standard was synthesized from (2-{sup 14}C)carboxyarabinitol 1,5-bisphosphate using acid phosphatase, and was added at the initial point of leaf extraction. Leaf CA1P was purified and its specific activity determined. CA1P was found in dark-treated leaves of all species examined, including spinach (Spinacea oleracea), wheat (Triticum aestivum), Arabidopsis thaliana, and maize (Zea mays). The highest amounts were found in bean (Phaseolus vulgaris) and petunia (Petunia hybrida), which had 1.5 to 1.8 moles CA1P per mole ribulose 1,5-bisphosphate carboxylase catalytic sites. Most species had intermediate amounts of CA1P (0.2 to 0.8 mole CA1P per mole catalytic sites). Such intermediate to high levels of CA1P support the hypothesis that CA1P functions in many species as a light-dependent regulator of ribulose 1,5-bisphosphate carboxylase activity and whole leaf photosynthetic CO{sub 2} assimilation. However, CA1P levels in spinach, wheat, and A. thaliana were particularly low (less than 0.09 mole CA1P per mole catalytic sites). In such species, CA1P does not likely have a significant role in regulating ribulose 1,5-bisphosphate carboxylase activity, but could have a different physiological role.

  1. Small Wind Energy Systems

    DEFF Research Database (Denmark)

    Simoes, Marcelo; Farret, Felix Alberto; Blaabjerg, Frede

    2015-01-01

    devices, and a centralized distribution control. In order to establish a small wind energy system it is important to observe the following: (i) Attending the energy requirements of the actual or future consumers; (ii) Establishing civil liabilities in case of accidents and financial losses due to shortage...... or low quality of energy; (iii) Negotiating collective conditions to interconnect the microgrid with the public network or with other sources of energy that is independent of wind resources; (iv) Establishing a performance criteria of power quality and reliability to end-users, in order to reduce costs...... and guaranteeing an acceptable energy supply. This paper discuss how performance is affected by local conditions and random nature of the wind, power demand profiles, turbine related factors, and presents the technical issues for implementing a self-excited induction generator system, or a permanent magnet based...

  2. Small caliber guided projectile

    Science.gov (United States)

    Jones, James F.; Kast, Brian A.; Kniskern, Marc W.; Rose, Scott E.; Rohrer, Brandon R.; Woods, James W.; Greene, Ronald W.

    2010-08-24

    A non-spinning projectile that is self-guided to a laser designated target and is configured to be fired from a small caliber smooth bore gun barrel has an optical sensor mounted in the nose of the projectile, a counterbalancing mass portion near the fore end of the projectile and a hollow tapered body mounted aft of the counterbalancing mass. Stabilizing strakes are mounted to and extend outward from the tapered body with control fins located at the aft end of the strakes. Guidance and control electronics and electromagnetic actuators for operating the control fins are located within the tapered body section. Output from the optical sensor is processed by the guidance and control electronics to produce command signals for the electromagnetic actuators. A guidance control algorithm incorporating non-proportional, "bang-bang" control is used to steer the projectile to the target.

  3. Small Business Innovations

    Science.gov (United States)

    1996-01-01

    Under a Small Business Innovation Research (SBIR) contract to Kennedy Space Center, EIC Laboratories invented a Raman Spectrograph with fiber optic sampling for space applications such as sensing hazardous fuel vapors and making on-board rapid analyses of chemicals and minerals. Raman spectroscopy is a laser-based measurement technique that provides through a unique vibrational spectrum a molecular 'fingerprint,' and can function in aqueous environments. EIC combined optical fiber technology with Raman methods to develop sensors that can be operated at a distance from the spectrographic analysis instruments and the laser excitation source. EIC refined and commercialized the technology to create the Fiber Optic Raman Spectrograph and the RamanProbe. Commercial applications range from process control to monitoring hazardous materials.

  4. Small intestinal transplantation.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    The past few years have witnessed a considerable shift in the clinical status of intestinal transplantation. A great deal of experience has been gained at the most active centers, and results comparable with those reported at a similar stage in the development of other solid-organ graft programs are now being achieved by these highly proficient transplant teams. Rejection and its inevitable associate, sepsis, remain ubiquitous, and new immunosuppressant regimes are urgently needed; some may already be on the near horizon. The recent success of isolated intestinal grafts, together with the mortality and morbidity attendant upon the development of advanced liver disease related to total parenteral nutrition, has prompted the bold proposal that patients at risk for this complication should be identified and should receive isolated small bowel grafts before the onset of end-stage hepatic failure. The very fact that such a suggestion has begun to emerge reflects real progress in this challenging field.

  5. Seminar on small PWRs

    International Nuclear Information System (INIS)

    The first of the three papers presented, reviews the history of small and medium power reactors. Although the category includes all reactors with an output up to 600MWe, the concentration is on the range 250-300MWe. Their suitability for developing countries and their economic aspects are discussed. The other two papers are concerned with the construction, transportation, installation and management of the Shore Test Facility for the prototype of the PWR 2, a reactor designed for use in submarines. The test facility was built at Barrow-in-Furness and then moved to its site in Caithness, Scotland. The methods used to move the enormous loads involved are described in detail. The construction and installation was planned over 5 years and involved a large number of people from the construction company, the Royal Navy and the contractors who operate the facility. The project management is described. (U.K.)

  6. Small Active Radiation Monitor

    Science.gov (United States)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the

  7. Small rover exploration capabilities

    Science.gov (United States)

    Salotti, Jean-Marc; Laithier, Corentin; Machut, Benoit; Marie, Aurélien; Bruneau, Audrey; Grömer, Gernot; Foing, Bernard H.

    2015-05-01

    For a human mission to the Moon or Mars, an important question is to determine the best strategy for the choice of surface vehicles. Recent studies suggest that the first missions to Mars will be strongly constrained and that only small unpressurized vehicles will be available. We analyze the exploration capabilities and limitations of small surface vehicles from the user perspective. Following the “human centered design” paradigm, the team focused on human systems interactions and conducted the following experiments: - Another member of our team participated in the ILEWG EuroMoonMars 2013 simulation at the Mars Desert Research Station in Utah during the same period of time. Although the possible traverses were restricted, a similar study with analog space suits and quads has been carried out. - Other experiments have been conducted in an old rock quarry close to Bordeaux, France. An expert in the use of quads for all types of terrains performed a demonstration and helped us to characterize the difficulties, the risks and advantages and drawbacks of different vehicles and tools. The vehicles that will be used on the surface of Mars have not been defined yet. Nevertheless, the results of our project already show that using a light and unpressurized vehicle (in the order of 150 kg) for the mobility on the Martian surface can be a true advantage. Part of the study was dedicated to the search for appropriate tools that could be used to make the vehicles easier to handle, safer to use and more efficient in the field to cross an obstacle. The final recommendation is to use winches and ramps, which already are widely used by quad drivers. We report on the extension of the reachable areas if such tools were available. This work has been supported by ILEWG, EuroMoonMars and the Austrian Space Forum (OEWF).

  8. Small intestine aspirate and culture

    Science.gov (United States)

    ... ency/article/003731.htm Small intestine aspirate and culture To use the sharing features on this page, please enable JavaScript. Small intestine aspirate and culture is a lab test to check for infection ...

  9. Small Area Fair Market Rent

    Data.gov (United States)

    Department of Housing and Urban Development — Due to the increasing demand for more localized rents for a variety of purposes, HUD is making Small Area FMRs for all metropolitan areas available. Small Area FMRs...

  10. Small intestine contrast injection (image)

    Science.gov (United States)

    ... and throat, through the stomach into the small intestine. When in place, contrast dye is introduced and ... means of demonstrating whether or not the small intestine is normal when abnormality is suspected.

  11. Quality and the Small School.

    Science.gov (United States)

    Hildebrand, Edwin P., Ed.

    The 1965-1968 progress report of the Western States Small Schools Project focuses on the problem and challenge posed by small schools, which have thus far lacked the depth of resources compared to urban schools. The goals of the project are to assist small schools to: (1) provide individualized programs of career selection education; (2) develop…

  12. Modified Small Business Network Security

    Directory of Open Access Journals (Sweden)

    Md. Belayet Ali

    2012-02-01

    Full Text Available This paper covers some likely threats and effectivesteps for a secure small business. It also involves a flowchart tocomprehend the overall small business network security easilyand we identify a set of security issues and applyappropriate techniques to satisfy the correspondingsecurity requirements. In respect of all, this document isstrong enough for any small business network security.

  13. Small Stirling Cycle Convertors

    Science.gov (United States)

    Penswick, L. Barry; Schreiber, Jeffery

    2005-02-01

    The Stirling convertor concept continues to be a viable potential candidate for various space power applications at electrical power levels ranging from greater than 100 KW to on the order of 10+watts. Various development efforts, both in the past and currently underway, have clearly demonstrated the potential for long operating life of this concept, its high efficiency in comparison to alternative power systems (>50% of Carnot based on electric power out to heat in), and its excellent specific power characteristics. A truly unique attribute of the Stirling convertor is the ability to maintain many of these same advantages at significantly lower electrical power levels (on the order of 1 watt and below). This provides the opportunity for a wider range of potential space power applications and the use of alternative heat sources operating at dramatically lower hot-end temperatures (about 250 °C vs. current values of about 650 °C). An overview of low-power Stirling convertors and related Stirling cooler technology is provided with an emphasis on assessing the technical maturity of this concept's key components at the low power level of interest. A conceptual design of a small, 1-watt (electrical output) Stirling convertor utilizing multiple Low Weight Radioisotope Heater Unit heat sources will be described. Key technical issues in the development of this power level Stirling convertor are discussed.

  14. Small Hydropower in Nigeria

    Institute of Scientific and Technical Information of China (English)

    P.EOKRANEFE; S.OWOLABI

    2002-01-01

    Nigeria is the most populaous black nation in the world. It has an area of 913,072 square kilometres. The country population is about 120 million. There are three major languages, Hausa, Yoruba and Igbo, although there is still more than 380 dialects in local languages. There are large number of household on the African continent that are unelectrified.In Nigeria about 70 million people remain literally in the dark without access to electricity. The majority of these numbers are in the rural areas. This workshop is apt in a number of ways. It is a joint effort between government, private sector, the academic and other practitioners in small hydro power station, it is also a promotion of business and industrial activities as well as development of renewable energy resources. I wish to commend the organizers of this workshop. The focus of the workshop is relevant to the agenda of the Federal Ministry of Power and Steel and aspirations of the Federal Government of Nigeria to provide regular and steady electricity to majority of Nigerians before the end of year 2001.

  15. Small Cell Lung Cancer.

    Science.gov (United States)

    Bernhardt, Erica B; Jalal, Shadia I

    2016-01-01

    Small cell lung cancer (SCLC) is an aggressive cancer of neuroendocrine origin, which is strongly associated with cigarette smoking. Patients typically present with a short duration of symptoms and frequently (60-65 %) with metastatic disease. SCLC is a heterogeneous disease including extremely chemosensitive and chemoresistant clones. For this reason, a high percentage of patients respond to first-line chemotherapy but rapidly succumb to the disease. SCLC is generally divided into two stages, limited and extensive. Standard treatment of limited stage disease includes combination chemotherapy with cisplatin and etoposide for four cycles, thoracic radiation initiated early with the first cycle of chemotherapy, and consideration of prophylactic cranial irradiation (PCI) in the subset of patients with good response. Surgery may play a role in TNM stages I and II. In extensive disease, platinum agents and etoposide, used in combination, are again the first-line standard of care in the USA. However, thoracic radiation therapy is used predominately in patients where local control is important and PCI is of uncertain benefit. Despite these treatments, prognosis remains poor and novel therapies are needed to improve survival in this disease. PMID:27535400

  16. Exposition regarding small windmills

    International Nuclear Information System (INIS)

    Emphasis is laid on the elucidation of the current situation of small windmills in Denmark by estimating the industry's strengths and weaknesses and evaluating the technical status and user economy relevant to these wind turbines, in addition to their technical and marketing potentials within the next 3-5 years. It is also attempted to survey and forecast their situation within a competitive market which includes marketing and sales potential outside Denmark, often by way of development projects financed by DANIDA (Danish International Development Agency, a department under the Danish Foreign Ministry that takes responsibility for Danish aid to developing countries, often by direct agreement). It is noted that it is difficult to make predictions in the light of currently rapidly changing global political aspects, but it is suggested that sales of smaller Danish windmills within the country could amount to 300-700 wind turbines by the year 2000. Regarding sales abroad, it is concluded that the current number will not increase unless great efforts are made within the export market and the instigation of close cooperation with foreign companies which use an international sales network and have access to local distribution channels. (AB) (15 refs.)

  17. Research using small tokamaks

    International Nuclear Information System (INIS)

    The technical reports contained in this collection of papers on research using small tokamaks fall into four main categories, i.e., (i) experimental work (heating, stability, plasma radial profiles, fluctuations and transport, confinement, ultra-low-q tokamaks, wall physics, a.o.), (ii) diagnostics (beam probes, laser scattering, X-ray tomography, laser interferometry, electron-cyclotron absorption and emission systems), (iii) theory (strong turbulence, effects of heating on stability, plasma beta limits, wave absorption, macrostability, low-q tokamak configurations and bootstrap currents, turbulent heating, stability of vortex flows, nonlinear islands growth, plasma-drift-induced anomalous transport, ergodic divertor design, a.o.), and (iv) new technical facilities (varistors applied to establish constant current and loop voltage in HT-6M), lower-hybrid-current-drive systems for HT-6B and HT-6M, radio-frequency systems for HT-6M ICR heating experimentation, and applications of fiber optics for visible and vacuum ultraviolet radiation detection as applied to tokamaks and reversed-field pinches. A total number of 51 papers are included in the collection. Refs, figs and tabs

  18. 48 CFR 970.1907 - Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business...

    Science.gov (United States)

    2010-10-01

    ... MANAGEMENT AND OPERATING CONTRACTS Small, Small Disadvantaged and Women-Owned Small Business Concerns 970.1907 Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business... Business, Small Disadvantaged Business and Woman-Owned Small Business Concerns. 970.1907 Section...

  19. Correlation between Expression of TUBB3/STMN1 and EGFR Signaling Pathway
 in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Bo WANG

    2013-10-01

    Full Text Available Background and objective It has been proven that biomarkers play a key role in the individualized treatment of lung cancer. Correlations between expressions of TUBB3/STMN1 and gene mutations of epidermal growth factor receptor (EGFR, Kirsten rat sarcoma viral oncogene homolog (KRAS, v-raf murine sarcoma viral oncogene homolog B (BRAF, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K in non-small cell lung cancer (NSCLC would be investigated and this may provide essential significance on prognosis and predictions of drug efficiency. Methods This study total enrolled 46 NSCLC patients. Tumor specimens were resected. The gene expressions of TUBB3, STMN1 were analyzed using branched DNA-liquidchip, and EGFR, KRAS, BRAF, PI3K gene mutations were detected by xTAG-liquidchip. Correlations between gene expressions and gene mutations were further analyzed by Spearman. Results Co-expressions between TUBB3 and STMN1 are strongly demonstrated, and high expression of TUBB3 always exists as well as high expression of STMN1 (P=0.006. Meanwhile mutation of EGFR E21 is negatively correlated with TUBB3, and wild type of EGFR E21 always exists toghther with high expression of TUBB3 (P=0.004,6, whereas mutation of KRAS E2 is positively associated with expression level of STMN1 (P=0.038,6. Conclusion Antimicrotubule drug resistance factors of TUBB3 and STMN1 may be related with mutations of EGFR signal pathway, suggesting that EGFR mutation and KRAS mutation may be important factors in regulation of TUBB3/STMN1 expression, which provided basic references for chemotherapeutic resistance.

  20. Small diameter carbon nanopipettes

    Science.gov (United States)

    Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

    2010-01-01

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 °C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 °C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  1. Small diameter carbon nanopipettes

    International Nuclear Information System (INIS)

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 deg. C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 deg. C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  2. Small angle neutron scattering

    Directory of Open Access Journals (Sweden)

    Cousin Fabrice

    2015-01-01

    Full Text Available Small Angle Neutron Scattering (SANS is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ∼ 1 nm up to ∼ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ∼ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area… through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer, form factor analysis (I(q→0, Guinier regime, intermediate regime, Porod regime, polydisperse system, structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates, and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast. It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of

  3. Joint research using small tokamaks

    International Nuclear Information System (INIS)

    Small tokamaks have an important role in fusion research. More than 40 small tokamaks are operational. Research on small tokamaks has created a scientific basis for the scaling-up to larger tokamaks. Well-known scientific and engineering schools, which are now determining the main directions of fusion science and technology, have been established through research on small tokamaks. Combined efforts within a network of small and medium size tokamaks will further enhance the contribution of small tokamaks. A new concept of interactive coordinated research using small tokamaks in the mainstream fusion science areas, in testing of new diagnostics, materials and technologies as well as in education, training and broadening of the geography of fusion research in the scope of the IAEA Coordinated Research Project, is presented

  4. Regular Small-World Network

    Institute of Scientific and Technical Information of China (English)

    ZOU Zhi-Yun; MAO Bao-Hua; HAO Hai-Ming; GAO Jian-Zhi; YANG Jie-Jiao

    2009-01-01

    According to the deficiencies in Watts and Strogatz's small-world network model, we present a new regular model to establish the small-world network. Besides the property of the small-world, this model has other properties such as accuracy in controlling the average shortest path length L, and the average clustering coefficient C, also regular network topology as well as enhanced network robustness. This method improves the construction of the small-world network essentially, so that the regular small-world network closely resembles the actual network. We also present studies on the relationships among the quantities of a variety of edges, L and C in regular small-world network in detail. This research lays the foundation for the establishment of the regular small-world network and acts as a good guidance for further research of this model and its applications.

  5. 77 FR 30227 - Small Business Size Regulations, Small Business Innovation Research (SBIR) Program and Small...

    Science.gov (United States)

    2012-05-22

    ... (SBIR) Program and Small Business Technology Transfer (STTR) Program AGENCY: U.S. Small Business... (SBIR) and Small Business Technology Transfer (STTR) Programs. The proposed rule would implement... technological constraints, participation is limited to 125 registrants for the Webinar. If demand...

  6. Small Bowel Hamartoma: A Huge Diverticulum of Small Bowel

    Directory of Open Access Journals (Sweden)

    Hamdi Ebdewi

    2013-01-01

    Full Text Available A-20-year old male, with no significant medical history, presented with clinical features mimicking a perforated acute appendicitis. Because of features of peritonitis, a laparotomy was performed which showed a segment of small bowel with multiple large diverticula and mesenteric cysts. A segmental small bowel resection was performed. The patient made an uneventful recovery from surgery. Histology revealed features of a small bowel hamartoma.

  7. Research using small tokamaks

    International Nuclear Information System (INIS)

    The technical reports in this document were presented at the IAEA Technical Committee Meeting ''Research on Small Tokamaks'', September 1990, in three sessions, viz., (1) Plasma Modes, Control, and Internal Phenomena, (2) Edge Phenomena, and (3) Advanced Configurations and New Facilities. In Section (1) experiments at controlling low mode number modes, feedback control using external coils, lower-hybrid current drive for the stabilization of sawtooth activity and continuous (1,1) mode, and unmodulated and fast modulated ECRH mode stabilization experiments were reported, as well as the relation to disruptions and transport of low m,n modes and magnetic island growth; static magnetic perturbations by helical windings causing mode locking and sawtooth suppression; island widths and frequency of the m=2 tearing mode; ultra-fast cooling due to pellet injection; and, finally, some papers on advanced diagnostics, i.e., lithium-beam activated charge-exchange spectroscopy, and detection through laser scattering of discrete Alfven waves. In Section (2), experimental edge physics results from a number of machines were presented (positive biasing on HYBTOK II enhancing the radial electric field and improving confinement; lower hybrid current drive on CASTOR improving global particle confinement, good current drive efficiency in HT-6B showing stabilization of sawteeth and Mirnov oscillations), as well as diagnostic developments (multi-chord time resolved soft and ultra-soft X-ray plasma radiation detection on MT-1; measurements on electron capture cross sections in multi-charged ion-atom collisions; development of a diagnostic neutral beam on Phaedrus-T). Theoretical papers discussed the influence of sheared flow and/or active feedback on edge microstability, large edge electric fields, and two-fluid modelling of non-ambipolar scrape-off layers. Section (3) contained (i) a proposal to construct a spherical tokamak ''Proto-Eta'', (ii) an analysis of ultra-low-q and runaway

  8. Small Wind Site Assessment Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Tim [Advanced Energy Systems LLC, Eugene, OR (United States); Preus, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Site assessment for small wind energy systems is one of the key factors in the successful installation, operation, and performance of a small wind turbine. A proper site assessment is a difficult process that includes wind resource assessment and the evaluation of site characteristics. These guidelines address many of the relevant parts of a site assessment with an emphasis on wind resource assessment, using methods other than on-site data collection and creating a small wind site assessment report.

  9. Small Spacecraft Activities at JPL

    OpenAIRE

    Jones, Ross

    1991-01-01

    This paper presents a brief technical description of some of the small spacecraft concepts prepared by JPL for various sponsors. Some of JPL's work in microspacecraft is presented. The paper contains brief technical descriptions of the following four small spacecraft conceptual designs: 1) Lunar GAS, 2) Polar Mesoscale Explorer, 3) DARPA SHF and 4) Discovery. Since 1986, JPL has studied more than 10 small spacecraft including those to be presented here.

  10. Leadership in a small enterprise

    OpenAIRE

    Palmgren, Helena

    2010-01-01

    Leadership is often seen as the premier force behind the success and failure of enterprises and the well-being of the personnel. In spite of the vast amount of studies on leadership, leadership in small enterprises has seldom been in focus in leadership research. The increasing importance of small firms to the economic growth and competitiveness raises questions about the role and practice of leadership in small enterprises. This study aims to deepen our understanding of leadership as a socia...

  11. Sustainability for a Small Country

    OpenAIRE

    Edwards, Geoff W.

    1992-01-01

    The main objective in this paper is to promote thinking on what "sustainable development" or "ecologically sustainable development" means for a small trading country. After a brief acknowledgement of some of the diverse literature on sustainability, there is a consideration of some realities facing a small trading economy. The balance of the paper comprises a discussion of the scope for a small country to enhance sustainability. This is done under several headings, corresponding to different ...

  12. Investigation on a Small Oscillogram

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A small oscillogram, one end of which was substituted by a bright point caused by the redox of an appropriate depolarizer and the other end of which was the redox of Hg or the redox of supporting electrolyte cation, was investigated in this paper. Experimental results of application of the small oscillogram to oscillographic determination of cefoperazone showed that the small oscillogram was more stable, sensitive, and less interference than classical oscillogram.

  13. Patient Safety Outcomes in Small Urban and Small Rural Hospitals

    Science.gov (United States)

    Vartak, Smruti; Ward, Marcia M.; Vaughn, Thomas E.

    2010-01-01

    Purpose: To assess patient safety outcomes in small urban and small rural hospitals and to examine the relationship of hospital and patient factors to patient safety outcomes. Methods: The Nationwide Inpatient Sample and American Hospital Association annual survey data were used for analyses. To increase comparability, the study sample was…

  14. Small white matter lesion detection in cerebral small vessel disease

    Science.gov (United States)

    Ghafoorian, Mohsen; Karssemeijer, Nico; van Uden, Inge; de Leeuw, Frank E.; Heskes, Tom; Marchiori, Elena; Platel, Bram

    2015-03-01

    Cerebral small vessel disease (SVD) is a common finding on magnetic resonance images of elderly people. White matter lesions (WML) are important markers for not only the small vessel disease, but also neuro-degenerative diseases including multiple sclerosis, Alzheimer's disease and vascular dementia. Volumetric measurements such as the "total lesion load", have been studied and related to these diseases. With respect to SVD we conjecture that small lesions are important, as they have been observed to grow over time and they form the majority of lesions in number. To study these small lesions they need to be annotated, which is a complex and time-consuming task. Existing (semi) automatic methods have been aimed at volumetric measurements and large lesions, and are not suitable for the detection of small lesions. In this research we established a supervised voxel classification CAD system, optimized and trained to exclusively detect small WMLs. To achieve this, several preprocessing steps were taken, which included a robust standardization of subject intensities to reduce inter-subject intensity variability as much as possible. A number of features that were found to be well identifying small lesions were calculated including multimodal intensities, tissue probabilities, several features for accurate location description, a number of second order derivative features as well as multi-scale annular filter for blobness detection. Only small lesions were used to learn the target concept via Adaboost using random forests as its basic classifiers. Finally the results were evaluated using Free-response receiver operating characteristic.

  15. Targeted therapies in development for non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Thanyanan Reungwetwattana

    2013-01-01

    Full Text Available The iterative discovery in various malignancies during the past decades that a number of aberrant tumorigenic processes and signal transduction pathways are mediated by "druggable" protein kinases has led to a revolutionary change in drug development. In non-small cell lung cancer (NSCLC, the ErbB family of receptors (e.g., EGFR [epidermal growth factor receptor], HER2 [human epidermal growth factor receptor 2], RAS (rat sarcoma gene, BRAF (v-raf murine sarcoma viral oncogene homolog B1, MAPK (mitogen-activated protein kinase c-MET (c-mesenchymal-epithelial transition, FGFR (fibroblast growth factor receptor, DDR2 (discoidin domain receptor 2, PIK3CA (phosphatidylinositol-4,5-bisphosphate3-kinase, catalytic subunit alpha, PTEN (phosphatase and tensin homolog, AKT (protein kinase B, ALK (anaplastic lym phoma kinase, RET (rearranged during transfection, ROS1 (reactive oxygen species 1 and EPH (erythropoietin-producing hepatoma are key targets of various agents currently in clinical development. These oncogenic targets exert their selective growth advantage through various intercommunicating pathways, such as through RAS/RAF/MEK, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin and SRC-signal transduction and transcription signaling. The recent clinical studies, EGFR tyrosine kinase inhibitors and crizotinib were considered as strongly effective targeted therapies in metastatic NSCLC. Currently, five molecular targeted agents were approved for treatment of advanced NSCLC: Gefitinib, erlotinib and afatinib for positive EGFR mutation, crizotinib for positive echinoderm microtubule-associated protein-like 4 (EML4-ALK translocation and bevacizumab. Moreover, oncogenic mutant proteins are subject to regulation by protein trafficking pathways, specifically through the heat shock protein 90 system. Drug combinations affecting various nodes in these signaling and intracellular processes are predicted and demonstrated to be synergistic and

  16. How Small Is a Billionth?

    Science.gov (United States)

    Gough, John

    2007-01-01

    Children's natural curiosity about numbers, big and small can lead to exploring place-value ideas. But how can these abstract concepts be experienced more concretely? This article presents some practical approaches for conceptualising very small numbers using linear models, area models, volume models, and diagrams.

  17. Resourcing Change in Small Schools

    Science.gov (United States)

    Anderson, Michelle; White, Simone

    2011-01-01

    The theme of this article is the challenge that school leaders face in creating the conditions for learning in small schools. We draw on the concepts of "social capital" and "social entrepreneurship" to identify tensions and possibilities for school leaders in a case study of a small rural school as they seek to find resources for school-community…

  18. Standard Deviation for Small Samples

    Science.gov (United States)

    Joarder, Anwar H.; Latif, Raja M.

    2006-01-01

    Neater representations for variance are given for small sample sizes, especially for 3 and 4. With these representations, variance can be calculated without a calculator if sample sizes are small and observations are integers, and an upper bound for the standard deviation is immediate. Accessible proofs of lower and upper bounds are presented for…

  19. Effect of fructose-1,6-bisphosphate on the myocardial ultrastructure and oxidative stress in Diabetic cardiomyopathy rats%1,6-二磷酸果糖对糖尿病大鼠心肌超微结构及氧化应激的影响

    Institute of Scientific and Technical Information of China (English)

    孙冬梅; 薛瑞凤; 郭淑香; 刘洋; 孙萌

    2010-01-01

    Objective To study the effect of Fructose-1,6-Bisphosphate ( FBP) on the myocardial ultrastructure and oxidative stress in rats with STZ-induced diabetic cardiomyopathy(DCM). Methods Diabetes mellitus model in healthy male Sprague-Dawley(SD) rats was induced by single injection of streptozotocin (STZ,Sigma)into intraperitoneal with a dose of 65mg/kg. Intervening subjects( FBP group) were given 500 mg/( kg · d) body weight of FBP intraperitoneal administration, while diabetes mellitus subjects ( DM group) and normal control subjects ( NC group) received 500 mg/( kg · d) of saline After one month, all rats were killed and the myocardial ultrastructures were studied by transmission electron microscopy (TEM). The contents of malondialdehyde(MDA) , activity of superoxide dismutase( SOD), nitric oxide synthase (NOS) and inductive nitric oxide synthase (iNOS) were measured in myocardial homogenate. Results Compared with NC group, more ruptured myofibril was found in DM group, as well as increased mitochondria, vacuolar degeneration and increased electron concentration of capillary basement membrane. At the same time, the concentration of MDA and activation of NOS and iNOS increased (P <0.05) , while the activation of NOS and iNOS in FBP group decreased (P < 0. 05). Conclusion FBP can protect diabetic myocardium and decrease oxidative stress.%目的 观察1,6-二磷酸果糖(FBP)对糖尿病大鼠心肌超微结构、氧化应激的影响.方法 将25只8周龄SPF级健康雄性SD大鼠按抽签法选择19只建立SD大鼠糖尿病模型,余下6只作为正常组.将造模成功的大鼠完全随机分成糖尿病组和FBP干预组(干预组,FBP 500 mg/kg·d腹腔注射),糖尿病组及正常组给予等量生理盐水腹腔注射.1个月后处死大鼠,取心肌组织进行透射电镜(TEM)观察,并测定心肌组织内氧化应激指标后进行比较.结果 与正常组相比,糖尿病组大鼠心肌肌原纤维断裂,线粒体增多、空泡变性,毛细血管基

  20. Small bowel obstruction- a surprise.

    Science.gov (United States)

    Mathew, Jeffrey Daniel; Cp, Ganesh Babu; M, Balachandar; M, Ramanathan

    2015-01-01

    Trans - omental hernia is very rare, accounting to 1-4% of all internal hernias which is an unusual cause of small bowel obstruction. Here we present a case report of a small bowel obstruction in a female due to trans - omental hernia presenting with central abdominal pain, distension and bilious vomiting. She had no previous history of trauma, surgery. Plain X-ray abdomen erect showed multiple air fluid levels with dilated small bowel loops. Emergency laparotomy revealed a segment of congested small bowel loop (ileum) through a defect in greater omentum. On table the herniated bowel loop was reduced and the defect in greater omentum was closed primarily. There was no necessity for bowel resection as it regained normal colour after reduction. Postoperative period was uneventful with complete resolution of symptoms. This case is presented for its rarity and its importance in clinical differential diagnosis of acute abdomen due to small bowel obstruction.

  1. 78 FR 11745 - Small Business Size Regulations, Small Business Innovation Research (SBIR) Program and Small...

    Science.gov (United States)

    2013-02-20

    ... Small Business Technology Transfer (STTR) Program; Correction AGENCY: U.S. Small Business Administration... Technology Transfer (STTR) programs. DATES: Effective February 20, 2013 and is applicable beginning January..., or Edsel Brown, Assistant Director, Office of Technology, at (202) 205-7343, or...

  2. 77 FR 76215 - Small Business Size Regulations, Small Business Innovation Research (SBIR) Program and Small...

    Science.gov (United States)

    2012-12-27

    ... (SBIR) Program and Small Business Technology Transfer (STTR) Program AGENCY: Small Business... Business Technology Transfer (STTR) programs. This rule implements provisions of the National Defense... Edsel Brown, Assistant Director, Office of Technology, at (202) 205-7343. You may also email...

  3. Board Effectiveness in Small Firms

    OpenAIRE

    Söderqvist, Anette; WÀgar, Karolina

    2010-01-01

    Purpose: This study investigates boards of directors in small firms and explores the link between board effectiveness and the composition, roles and working styles of the boards. Design/methodology/approach: The study analyses data from a telephone survey of boards in 45 small firms. The survey included both the CEO and the chairperson of the board. Findings: The study identifies three groups of small firms: ‘paperboards’, ‘professional boards’, and ‘management ...

  4. Small Sat Analysis Laboratory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Low-Cost Small Spacecraft Program is focused on the technologies, subsystems, methodologies, and mission concepts for space missions which lower the...

  5. Quantum Small-world Networks

    CERN Document Server

    Wei, Zong-Wen; Han, Xiao-Pu

    2011-01-01

    Quantum networks are critical to quantum communication and distributed quantum computing. Here we propose a small-world model of large-scale quantum repeater networks, where "small-world" is a fundamental concept rooted in complex networks, which describe a broad range of real systems. The core of the model is to relate the hierarchical fashion of measurements to coarse-graining process, when quantum repeater protocols are implemented. We demonstrate that quantum repeater networks with fractal structure can be enlarged with certain length scale in geographic space, while preserving topology by performing renormalization. Actually, renormalization here serves as an organizing principle determining the distribution of long-range entangled links over quantum networks, which gives rise to fractal to small-world transition. Furthermore, by iterative implementation of renormalization on the former coarse-grained network, we eventually obtain an onion-like, hierarchical quantum small-world network, where the distanc...

  6. Small satellites and their regulation

    CERN Document Server

    Jakhu, Ram S

    2014-01-01

    Since the launch of UoSat-1 of the University of Surrey (United Kingdom) in 1981, small satellites proved regularly to be useful, beneficial, and cost-effective tools. Typical tasks cover education and workforce development, technology demonstration, verification and validation, scientific and engineering research as well as commercial applications. Today the launch masses range over almost three orders of magnitude starting at less than a kilogram up to a few hundred kilograms, with budgets of less than US$ 100.00 and up to millions within very short timeframes of sometimes less than two years. Therefore each category of small satellites provides specific challenges in design, development and operations. Small satellites offer great potentials to gain responsive, low-cost access to space within a short timeframe for institutions, companies, regions and countries beyond the traditional big players in the space arena. For these reasons (particularly the low cost of construction, launch and operation), small (m...

  7. Public Relations for Small Schools.

    Science.gov (United States)

    Seifert, Edward H.; Lott, Chester N.

    1981-01-01

    Discusses economically feasible and sensible methods of school-community relations for implementation in small schools; a multifaceted communication approach should be implemented which includes news releases, newsletters, advisory committees, and internal communication. (Author/LC)

  8. Small Probe Reentry System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Aerospace Corporation (GAC), and its research partner, Cal Poly San Luis Obispo (CPSLO), will develop an integrated Small Probe Reentry System (SPRS) for low...

  9. Development project of small accelerator

    CERN Document Server

    Yamada, S

    2002-01-01

    The object of this project is demonstration of a small proton and heavy ion synchrotron and a small hard X-ray photon radiation source by using new technology and application of them to therapy, diagnosis, material science and life science. In this paper, a part of small proton and heavy ion synchrotron is discussed. Nine organizations joined in this project. There are four development themes such as optimization of laser-ion 100 TW class source target, beam storage and cooling device, small synchrotron ring and FFAG accelerator. Outline and contents of development of them are explained. This project is planning to generate a few MeV/u carbon ions in fully ionized states by impact of laser with about 100 TW output. 3 T maximum bending magnetic field using normal conduction AC magnet will be actualized for synchrotron with 200 MeV proton beam. (S.Y.)

  10. Small Sat Analysis Laboratory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop Small Satellite Analysis Laboratory (SatLab): A simulation-of-simulations framework to integrate component and engineering simulations into a single larger...

  11. JPL Small Body Database Browser

    Data.gov (United States)

    National Aeronautics and Space Administration — The JPL Small-Body Database Browser provides data for all known asteroids and many comets. Newly discovered objects and their orbits are added on a daily basis....

  12. Small for gestational age (SGA)

    Science.gov (United States)

    ... is called intrauterine growth restriction. The most common definition of small for gestational age (SGA) is a ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  13. Small Bowel Review - Part I

    OpenAIRE

    Thomson, ABR; Wild, G.

    1997-01-01

    Significant advances have been made in the study of the small bowel. Part I of this two-part review of the small bowel examines carbohydrates, including brush border membrane hydrolysis and sugar transport; amino acids, dipeptides, proteins and food allergy, with a focus on glutamine, peptides and macromolecules, and nucleosides, nucleotides and polyamines; salt and water absorption, and diarrhea, including antidiarrheal therapy and oral rehydration treatment; lipids (digestion and absorption...

  14. Small windpower systems are beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Conway, A.

    1988-11-01

    Today's small wind turbine generators perform well and reliably, thanks to brushless alternators, composite blades and protection against high winds. Wind turbines of such dimensions would often be employed for battery chargers. Bigger, geared machines, with rotors of up to 17 m diameter, driving synchronous or induction generators, would be coupled with diesel sets for supplying small communities. Battery chargers, island and hybrid systems and possible sites are discussed.

  15. A Rubisco mutant that confers growth under a normally “inhibitory” oxygen concentration†

    OpenAIRE

    Satagopan, Sriram; Scott, Stephanie S.; Smith, Todd G.; Tabita, F. Robert

    2009-01-01

    Ribulose 1, 5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco) is a globally significant biocatalyst that facilitates the removal and sequestration of CO2 from the biosphere. Rubisco-catalyzed CO2 reduction thus provides virtually all the organic carbon utilized by living organisms. Despite catalyzing the rate-limiting step of photosynthetic and chemoautotrophic CO2 assimilation, Rubisco is markedly inefficient as the competition between O2 and CO2 for the same substrate limits the ability...

  16. Contrasting Diversity and Host Association of Ectomycorrhizal Basidiomycetes versus Root-Associated Ascomycetes in a Dipterocarp Rainforest

    OpenAIRE

    Sato, Hirotoshi; Tanabe, Akifumi S; Toju, Hirokazu

    2015-01-01

    Root-associated fungi, including ectomycorrhizal and root-endophytic fungi, are among the most diverse and important belowground plant symbionts in dipterocarp rainforests. Our study aimed to reveal the biodiversity, host association, and community structure of ectomycorrhizal Basidiomycota and root-associated Ascomycota (including root-endophytic Ascomycota) in a lowland dipterocarp rainforest in Southeast Asia. The host plant chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase large...

  17. Influence of temperature on measurements of the CO2 compensation point: differences between the Laisk and O2-exchange methods

    OpenAIRE

    Walker, Berkley J.; Cousins, Asaph B.

    2013-01-01

    The CO2 compensation point in the absence of day respiration (Γ*) is a key parameter for modelling leaf CO2 exchange. Γ* links the kinetics of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) with the stoichiometry of CO2 released per Rubisco oxygenation from photorespiration (α), two essential components of biochemical models of photosynthesis. There are two main gas-exchange methods for measuring Γ*: (i) the Laisk method, which requires estimates of mesophyll conductance to CO2 (g ...

  18. World Small Hydropower Development Report

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Heng; Esser, Lara (ICSGP (China)); Masera, Diego (UNIDO, Vienna (Austria))

    2013-07-01

    Currently, small hydropower plants with a capacity of 10 MW, exist in 148 countries or territories worldwide. Four other countries have been identified with resource potential. This report aims to identify the development status and resource potential of small hydro in various countries, territories and regions throughout the world. Working with experts at the ground level to compile and share existing information, experiences and challenges, one comprehensive report was created. Decision-makers, stakeholders and potential investors clearly need this comprehensive information to more effectively promote small hydropower as a renewable and rural energy source for sustainable development and to overcome the existing development barriers. The findings of this report show that small hydropower potential globally is approximated at almost 173 GW. The figure is arrived by totaling data from a wide range of sources with potential compromise of data integrity to varying degrees. For example, research data on economically feasible potential were more readily available in developed countries than those in the least developed or developing countries. More than half of the world's known hydropower potential is located in Asia, around one third can be found in Europe and the Americas. It is possible in the future that more small hydropower potential might be identified both on the African and American continents. The installed small hydropower capacity (up to 10 MW) is estimated to be 75 GW in 2011/2012. The report provides detailed data for each country/region, including recommendations on the national, regional and international level.

  19. Small

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Joseph

    2013-07-18

    Representing the Center on Nanostructuring for Efficient Energy Conversion (CNEEC), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of CNEEC is to understand how nanostructuring can enhance efficiency for energy conversion and solve fundamental cross-cutting problems in advanced energy conversion and storage systems.

  20. Small bowel faeces sign in patients without small bowel obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, S.L. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States)]. E-mail: stacylynnjacobs@yahoo.com; Rozenblit, A. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States); Ricci, Z. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States); Roberts, J. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States); Milikow, D. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States); Chernyak, V. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States); Wolf, E. [Department of Radiology, Montefiore Medical Center, Bronx, NY (United States)

    2007-04-15

    Aim: To evaluate frequency and clinical relevance of the 'small bowel faeces' sign (SBFS) on computed tomography (CT) in patients with and without small bowel obstruction (SBO) presenting with acute abdominal or acute abdominal and flank pain. Methods: Abdominal CTs of consecutive patients presenting to the emergency department with abdominal or flank pain over a 6 month period were retrospectively reviewed by six radiologists, independently, for the presence of the SBFS. Examinations with positive SBFS were further evaluated in consensus by three radiologists, blinded to the final diagnosis. The small bowel was graded as non-dilated (<2.5 cm) and mildly (2.5-2.9 cm), moderately (3-4 cm) or severely (>4 cm) dilated. The location of SBFS and presence of distal small bowel collapse indicative of SBO was recorded. Imaging findings were subsequently correlated with the final diagnosis via chart review and compared between patients with and without SBO. Results: Of 1642 CT examinations, a positive SBFS was found in 100 (6%) studies. Of 100 patients with a positive SBFS, 32 (32%) had documented SBO. The remaining 68 patients had other non-obstructive diagnoses. SBFS was located in proximal, central, distal and multisegmental bowel loops in one (3.1%), eight (25.0%), 21 (65.6%) and two (6.3%) patients with SBO, and in zero (0%), 10 (14.7%), 53 (77.9%) and five (7.4%) of patients without SBO (p < 0.273). The small bowel was non-dilated and mildly, moderately or severely dilated in one (3%), five (16%), 20 (62%) and six (19%) patients with SBO, and in 61(90%), seven (10%), zero (0%) and zero (0%) patients without SBO. Normal or mildly dilated small bowel was seen in all (100%) patients without SBO, but only in six (19%) of 32 patients with SBO (p < 0.0001). Moderate or severe small bowel dilatation was seen in 26 (81%) patients with SBO (p < 0.0001), but it was absent in patients without SBO. Distal small bowel collapse was found in 27 (84.4%) of 32 patients with

  1. Tumours in the Small Bowel

    Directory of Open Access Journals (Sweden)

    N. Kurniawan

    2014-01-01

    Full Text Available Small bowel tumours are rare and originate from a wide variety of benign and malignant entities. Adenocarcinomas are the most frequent primary malignant small bowel tumours. Submucosal tumours like gastrointestinal stromal tumours (GIST or neuroendocrine tumours (NET may show a central umbilication, pathologic vessels, bridging folds or an ulceration of the overlying mucosa. These signs help to differentiate them from harmless bulges caused by impression from outside, e.g. from other intestinal loops. Sarcomas of the small bowel are rare neoplasias with mesenchymal origin, sometimes presenting as protruding masses. Benign tumours like lipoma, fibrolipoma, fibroma, myoma, and heterotopias typically present as submucosal masses. They cannot be differentiated endoscopically from those with malignant potential as GIST or NET. Neuroendocrine carcinomas may present with diffuse infiltration, which may resemble other malignant tumours. The endoscopic appearance of small bowel lymphomas has a great variation from mass lesions to diffuse infiltrative changes. Melanoma metastases are the most frequent metastases to the small bowel. They may be hard to distinguish from other tumours when originating from an amelanotic melanoma.

  2. Small satellites for tropical applications

    Science.gov (United States)

    Montpetit, Marie-Jose; Bonn, Ferdinand

    1993-11-01

    A number of mission studies were performed to assess the suitability of small satellite systems for tropical data acquisition. These studies took into account the specifics of the tropical user communities and were focused on remote sensing and resource management issues. The requirements and potential solutions for four application areas are discussed. For monitoring of forest and agricultural vegetation, a small synthetic aperture radar is considered with P, C, or X band imaging, possibly supplemented by a high resolution multispectral imager. The radar would have the capability to monitor below cloud cover which is often found in tropical regions. Optical, microwave, or spectrographic imaging would also be useful in small satellites for disaster monitoring (notably of floods), land management, and air pollution monitoring. A small satellite with data storage and forwarding capability is also envisioned to collect data from dependable, low-power, and low-cost ground sensors via a simple ultrahigh frequency uplink and download the data on a very high frequency downlink. All the small satellites would be launched in low inclination orbits to ensure a number of consecutive passes over the targeted tropical area.

  3. Small-ductprimarysclerosingcholangitis withhepatocellularcarcinomarequiringliver transplantation

    Institute of Scientific and Technical Information of China (English)

    Sharif Ali; Veena Shah

    2010-01-01

    BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic progressive cholestatic liver disease, which usually affects young adults and is diagnosed by cholangiography. On a few occasions, the disease either starts in or exclusively involves the small intrahepatic bile ducts, referred to as small-duct PSC. METHODS: A 31-year-old man presented with severe hematemesis secondary to liver cirrhosis. Over a course of 8 years, his liver decompensated and required an orthotopic liver transplantation. In this report we discuss his disease presentation, course of management, and the post-transplantation course of manage-ment, and review the morphologic diagnosis, and differential diagnosis of the disease with large-duct type and other diseases that involve small intrahepatic bile ducts. RESULTS:The patient's explanted liver showed changes of PSC affecting only the small- and medium-sized bile ducts in addition to three incidental nodules of hepatocellular carcinoma. CONCLUSIONS: Small-duct PSC has a substantially better prognosis than the large-duct type, with less chance of developing cirrhosis and an equal risk for developing hepato-cellular carcinoma, but no increased risk for developing cholangiocarcinoma. Treatment seems to help relieve the symptoms but not necessarily improve survival. Liver transplantation remains the ultimate cure.

  4. Industry Research and Recommendations for Small Buildings and Small Portfolios

    Energy Technology Data Exchange (ETDEWEB)

    Langner, Rois [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hendron, Bob [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pless, Shanti [National Renewable Energy Lab. (NREL), Golden, CO (United States); Huppert, Mark [National Trust for Historic Preservation, Washington, DC (United States); Cochrane, Ric [National Trust for Historic Preservation, Washington, DC (United States)

    2013-12-01

    Small buildings have been left behind in the energy efficiency marketplace because financial and technical resources have flowed to larger commercial buildings. DOE's Building Technologies Office works with the commercial building industry to accelerate the uptake of energy efficiency technologies and techniques in existing and new commercial buildings (DOE 2013). BTO recognizes the SBSP sector'spotential for significant energy savings and the need for investments in resources that are tailored to this sector's unique needs. The industry research and recommendations described in this report identify potential approaches and strategic priorities that BTO could explore over the next 3-5 years that will support the implementation of high-potential energy efficiency opportunities for thisimportant sector. DOE is uniquely positioned to provide national leadership, objective information, and innovative tools, technologies, and services to support cost-effective energy savings in the fragmented and complex SBSP sector. Properly deployed, the DOE effort could enhance and complement current energy efficiency approaches. Small portfolios are loosely and qualitatively defined asportfolios of buildings that include only a small number of small buildings. This distinction is important because the report targets portfolio owners and managers who generally do not have staff and other resources to track energy use and pursue energy efficiency solutions.

  5. Marketing the Uniqueness of Small Towns. Small Town Strategy.

    Science.gov (United States)

    Hogg, David H.; Dunn, Douglas

    A small town can strengthen its local economy as a result of business people and concerned citizens collectively identifying that community's uniqueness and then capitalizing on it via advertising, personal selling, sales promotion, or publicity. This publication relates the science of marketing to communities. Seven simple techniques are provided…

  6. Small Business Social Responsibility Communication

    DEFF Research Database (Denmark)

    Morsing, Mette; Spence, Laura J.

    2015-01-01

    ) are confronting owner-managers’ ethos. We explain theoretically how small business managers respond to the challenge when they are required to formalize and display for external surveillance that which would otherwise be informal and part of the non-public or private sphere.......Purpose: Corporate social responsibility communication by small and medium sized enterprises is theorized to form the concept of Small Business Social Responsibility (SBSR) Communication. Design/methodology/approach: This is a conceptual paper that draws on Foucault’s theory of governmentality...... to develop a theoretical explanation for SBSR communication. Findings: Our analysis conceptualizes the ‘governmentality dilemma’ as SBSR managers face two simultaneous and potentially counterproductive expectations: responding to externally prescribed expectations, norms and standards such as branding, codes...

  7. Studies in small field inflation

    International Nuclear Information System (INIS)

    We explore some issues in slow roll inflation in situations where field excursions are small compared to Mp. We argue that for small field inflation, minimizing fine tuning requires low energy supersymmetry and a tightly constrained structure. Hybrid inflation is almost an inevitable outcome. The resulting theory can be described in terms of a supersymmetric low energy effective action and inflation completely characterized in terms of a small number of parameters. Demanding slow roll inflation significantly constrains these parameters. In this context, the generic level of fine tuning can be described as a function of the number of light fields, there is an upper bound on the scale of inflation, and an (almost) universal prediction for the spectral index. Models of this type need not suffer from a cosmological moduli problem

  8. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    International Nuclear Information System (INIS)

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity

  9. Compound 13, an α1-selective small molecule activator of AMPK, inhibits Helicobacter pylori-induced oxidative stresses and gastric epithelial cell apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hangyong; Zhu, Huanghuang; Lin, Zhou; Lin, Gang; Lv, Guoqiang, E-mail: lvguoqiangwuxivip@163.com

    2015-08-07

    Half of the world's population experiences Helicobacter pylori (H. pylori) infection, which is a main cause of gastritis, duodenal and gastric ulcer, and gastric cancers. In the current study, we investigated the potential role of compound 13 (C13), a novel α1-selective small molecule activator of AMP-activated protein kinase (AMPK), against H. pylori-induced cytotoxicity in cultured gastric epithelial cells (GECs). We found that C13 induced significant AMPK activation, evidenced by phosphorylation of AMPKα1 and ACC (acetyl-CoA carboxylase), in both primary and transformed GECs. Treatment of C13 inhibited H. pylori-induced GEC apoptosis. AMPK activation was required for C13-mediated GEC protection. Inhibition of AMPK kinase activity by the AMPK inhibitor Compound C, or silencing AMPKα1 expression by targeted-shRNAs, alleviated C13-induced GEC protective activities against H. pylori. Significantly, C13 inhibited H. pylori-induced reactive oxygen species (ROS) production in GECs. C13 induced AMPK-dependent expression of anti-oxidant gene heme oxygenase (HO-1) in GECs. Zinc protoporphyrin (ZnPP) and tin protoporphyrin (SnPP), two HO-1 inhibitors, not only suppressed C13-mediated ROS scavenging activity, but also alleviated its activity in GECs against H. pylori. Together, these results indicate that C13 inhibits H. pylori-induced ROS production and GEC apoptosis through activating AMPK–HO–1 signaling. - Highlights: • We synthesized compound 13 (C13), a α1-selective small molecule AMPK activator. • C13-induced AMPK activation requires α1 subunit in gastric epithelial cells (GECs). • C13 enhances Helicobacter pylori-induced pro-survival AMPK activation to inhibit GEC apoptosis. • C13 inhibits H. pylori-induced reactive oxygen species (ROS) production in GECs. • AMPK-heme oxygenase (HO-1) activation is required for C13-mediated anti-oxidant activity.

  10. Small Wind Turbine Technology Assessment

    International Nuclear Information System (INIS)

    The result of the study carried out under the scope of the ATYCA project Test Plant of Wind Systems for Isolated Applications, about the state of art of the small wind turbine technology (wind turbines with swept area smaller than 40 m2) is presented. The study analyzes the collected information on 60 models of wind turbines from 23 manufacturers in the worldwide market. Data from Chinese manufacturers, that have a large participation in the total number of small wind turbines in operation, are not included, due to the unavailability of the technical information. (Author) 15 refs

  11. Appropriate technology for small turbines

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, F.; Walch, E.

    1981-11-01

    The investment costs of small-scale hydro plants are relatively high; of these the electro-mechanical equipment is generally a high proportion. One way of reducing these costs is to use information and experience gained in the manufacture of equipment for large plants, avoiding expensive testing and assessment. To exploit this experience, a standard program has been developed which can be applied quickly and easily for the design of small turbines. In this way the best choice of turbines and configurations can be determined rapidly for any site.

  12. Particles in small volume injections.

    Science.gov (United States)

    Taylor, S A; Spence, J

    1983-12-01

    The level of particulate contamination in small volume injections has been examined using the light blockage (HIAC) and electrical sensing zone (Coulter counter) techniques, the HIAC system being found to be the more suitable. Particle counts on the same batch of injection showed a large and variable difference between the HIAC and the Coulter counter results, especially below 5 micron. None of the injections examined complied with the British Pharmacopoeia limits for particulates in large volume parenterals, suggesting the unsuitability of the limits for small volume parenterals. PMID:6141237

  13. Small molecule inhibition of 6-phosphofructo-2-kinase suppresses t cell activation

    Directory of Open Access Journals (Sweden)

    Telang Sucheta

    2012-05-01

    Full Text Available Abstract Background T cell activation is associated with a rapid increase in intracellular fructose-2,6-bisphosphate (F2,6BP, an allosteric activator of the glycolytic enzyme, 6-phosphofructo-1-kinase. The steady state concentration of F2,6BP in T cells is dependent on the expression of the bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (PFKFB1-4 and the fructose-2,6-bisphosphatase, TIGAR. Of the PFKFB family of enzymes, PFKFB3 has the highest kinase:bisphosphatase ratio and has been demonstrated to be required for T cell proliferation. A small molecule antagonist of PFKFB3, 3-(3-pyridinyl-1-(4-pyridinyl-2-propen-1-one (3PO, recently has been shown to reduce F2,6BP synthesis, glucose uptake and proliferation in transformed cells. We hypothesized that the induction of PFKFB3 expression may be required for the stimulation of glycolysis in T cells and that exposure to the PFKFB3 antagonist, 3PO, would suppress T cell activation. Methods We examined PFKFB1-4 and TIGAR expression and F2,6BP concentration in purified CD3+ T cells stimulated with microbead-conjugated agonist antibodies specific for CD3 and the co-stimulatory receptor, CD28. We then determined the effect of 3PO on anti-CD3/anti-CD28-induced T cell activation, F2,6BP synthesis, 2-[1-14C]-deoxy-d-glucose uptake, lactate secretion, TNF-α secretion and proliferation. Finally, we examined the effect of 3PO administration on the development of delayed type hypersensitivity to methylated BSA and on imiquimod-induced psoriasis in mice. Results We found that purified human CD3+ T cells express PFKFB2, PFKFB3, PFKFB4 and TIGAR, and that anti-CD3/anti-CD28 conjugated microbeads stimulated a >20-fold increase in F2,6BP with a coincident increase in protein expression of the PFKFB3 family member and a decrease in TIGAR protein expression. We then found that exposure to the PFKFB3 small molecule antagonist, 3PO (1–10 μM, markedly attenuated the stimulation of F2,6BP

  14. The growth of soybean under free air [CO(2)] enrichment (FACE) stimulates photosynthesis while decreasing in vivo Rubisco capacity.

    Science.gov (United States)

    Bernacchi, Carl J; Morgan, Patrick B; Ort, Donald R; Long, Stephen P

    2005-01-01

    Down-regulation of light-saturated photosynthesis (A(sat)) at elevated atmospheric CO(2) concentration, [CO(2)], has been demonstrated for many C(3) species and is often associated with inability to utilize additional photosynthate and/or nitrogen limitation. In soybean, a nitrogen-fixing species, both limitations are less likely than in crops lacking an N-fixing symbiont. Prior studies have used controlled environment or field enclosures where the artificial environment can modify responses to [CO(2)]. A soybean free air [CO(2)] enrichment (FACE) facility has provided the first opportunity to analyze the effects of elevated [CO(2)] on photosynthesis under fully open-air conditions. Potential ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V(c,max)) and electron transport through photosystem II (J(max)) were determined from the responses of A(sat) to intercellular [CO(2)] (C(i)) throughout two growing seasons. Mesophyll conductance to CO(2) (g(m)) was determined from the responses of A(sat) and whole chain electron transport (J) to light. Elevated [CO(2)] increased A(sat) by 15-20% even though there was a small, statistically significant, decrease in V(c,max). This differs from previous studies in that V(c,max)/J(max) decreased, inferring a shift in resource investment away from Rubisco. This raised the C(i) at which the transition from Rubisco-limited to ribulose-1,5-bisphosphate regeneration-limited photosynthesis occurred. The decrease in V(c,max) was not the result of a change in g(m), which was unchanged by elevated [CO(2)]. This first analysis of limitations to soybean photosynthesis under fully open-air conditions reveals important differences to prior studies that have used enclosures to elevate [CO(2)], most significantly a smaller response of A(sat) and an apparent shift in resources away from Rubisco relative to capacity for electron transport. PMID:15252734

  15. Small Business Innovations (Crystal Components)

    Science.gov (United States)

    1991-01-01

    Scientific Materials Corporation, Bozeman, MT developed the SciMax line of improved Nd:Yag crystals under an Small Business Innovation Research (SBIR) contract with Langley Research Center. They reduced the amount of water trapped in the crystals during growth to improve the optical quality and efficiency. Applications of the crystals include fiber optics, telecommunications, welding, drilling, eye surgery and medical instrumentation.

  16. Small Signal Loudspeaker Impedance Emulator

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold

    2014-01-01

    from driver to driver. Therefore, a loudspeaker emulator capable of adjusting its impedance to that of a given driver is desired for measurement purposes. This paper proposes a loudspeaker emulator circuit for small signals. Simulations and experimental results are compared and show that it is possible...

  17. Exact completions and small sheaves

    CERN Document Server

    Shulman, Michael

    2012-01-01

    We prove a general theorem which includes most notions of "exact completion". The theorem is that "k-ary exact categories" are a reflective sub-2-category of "k-ary sites", for any regular cardinal k. A k-ary exact category is an exact category with disjoint and universal k-small coproducts, and a k-ary site is a site whose covering sieves are generated by k-small families and which satisfies a weak size condition. For different values of k, this includes the exact completions of a regular category or a category with (weak) finite limits; the pretopos completion of a coherent category; and the category of sheaves on a small site. For a large site with k the size of the universe, it gives a well-behaved "category of small sheaves". Along the way, we define a slightly generalized notion of "morphism of sites", and show that k-ary sites are equivalent to a type of "enhanced allegory".

  18. Microwave Levitation Of Small Objects

    Science.gov (United States)

    Watkins, John L.; Jackson, Henry W.

    1991-01-01

    Microwave radiation in resonant cavities used to levitate small objects, according to proposal. Feedback control and atmosphere not needed. Technique conceived for use in experiments on processing of materials in low gravitation of outer space, also used in normal Earth gravitation, albeit under some limitations.

  19. Small firm transformation through IS

    NARCIS (Netherlands)

    Levy, Margi; Powell, Philip

    2008-01-01

    Globally, Small and Medium-sized Enterprises (SMEs) are encouraged, particularly by governments, to embrace c-business. Fully adopting e-business involves substantial change in firms, both internally and externally. However, there is little understanding of the mechanisms by which such business tran

  20. Economics: An Emerging Small World?

    NARCIS (Netherlands)

    S. Goyal (Sanjeev); M.J. van der Leij (Marco); J.L. Moraga-Gonzalez (José Luis)

    2004-01-01

    textabstractThis paper examines the small world hypothesis. The first part of the paper presents empirical evidence on the evolution of a particular world: the world of journal publishing economists during the period 1970-2000. We find that in the 1970's the world of economics was a collection of is

  1. Small Turing universal signal machines

    Directory of Open Access Journals (Sweden)

    Jérôme Durand-Lose

    2009-06-01

    Full Text Available This article aims at providing signal machines as small as possible able to perform any computation (in the classical understanding. After presenting signal machines, it is shown how to get universal ones from Turing machines, cellular-automata and cyclic tag systems. Finally a halting universal signal machine with 13 meta-signals and 21 collision rules is presented.

  2. Small animal radiotherapy research platforms

    International Nuclear Information System (INIS)

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  3. Small animal radiotherapy research platforms

    Science.gov (United States)

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-06-01

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research.

  4. Small bowel transplantation: An overview

    NARCIS (Netherlands)

    R.W.F. de Bruin (Ron); E. Heineman (Erik); R.L. Marquet (Richard)

    1994-01-01

    textabstractSmall bowel transplantation (SBT) would, in theory, be the treatment of choice for patients suffering from the short bowel syndrome. Although SBT has been done with a considerable degree of success in some centers [36,145], it is by no means an established or widely applicable therapy fo

  5. Sonography of the small intestine

    Institute of Scientific and Technical Information of China (English)

    Kim Nylund; Svein (φ)degaard; Trygve Hausken; Geir Folvik; Gülen Arslan Lied; Ivan Viola; Helwig Hauser; Odd-Helge Gilja

    2009-01-01

    In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy and double-balloon endoscopy, ultrasonography has the advantage of being cheap, portable, flexible and user- and patient-friendly, while at the same time providing the clinician with image data of high temporal and spatial resolution. The method has limitations with penetration in obesity and with intestinal air impairing image quality. The flexibility ultrasonography offers the examiner also implies that a systematic approach during scanning is needed. This paper reviews the basic scanning techniques and new modalities such as contrast-enhanced ultrasound, elastography, strain rate imaging, hydrosonography, allergosonography, endoscopic sonography and nutritional imaging, and the literature on disease-specific findings in the small intestine. Some of these methods have shown clinical benefit, while others are under research and development to establish their role in the diagnostic repertoire. However, along with improved overall image quality of new ultrasound scanners, these methods have enabled more anatomical and physiological changes in the small intestine to be observed. Accordingly, ultrasound of the small intestine is an attractive clinical tool to study patients with a range of diseases.

  6. Calculator. Owning a Small Business.

    Science.gov (United States)

    Parma City School District, OH.

    Seven activities are presented in this student workbook designed for an exploration of small business ownership and the use of the calculator in this career. Included are simulated situations in which students must use a calculator to compute property taxes; estimate payroll taxes and franchise taxes; compute pricing, approximate salaries,…

  7. Economics : An emerging small world

    NARCIS (Netherlands)

    Goyal, S; van der Leij, MJ; Moraga-Gonzalez, JL

    2006-01-01

    We study the evolution of social distance among economists over the period 1970-2000. While the number of economists has more than doubled, the distance between them, which was already small, has declined significantly. The key to understanding the short average distances is the observation that eco

  8. Small store presence in Japan

    NARCIS (Netherlands)

    M.A. Carree (Martin); J.C.A. Potjes; A.R. Thurik (Roy)

    1993-01-01

    textabstractThe determinants of the development of small store presence in Japan are investigated using a fixed effects multinomial logit market share model. Large stores tend to have higher market shares in shop-types with increasing shares in consumer expenditures, increasing inventory turnover, a

  9. Research on the Correlation of the Acetyl-CoA Carboxylase Activity and Fatty Acid Contents of Chufa (Cyperus esculentus L.Var.sativus)%油莎豆叶片发育过程中乙酰辅酶A羧化酶活性与脂肪酸含量的变化及其相关性分析

    Institute of Scientific and Technical Information of China (English)

    杨若琳; 杨敏; 张芬; 田丽萍; 薛琳

    2013-01-01

    [目的]研究油莎豆叶片中的乙酰辅酶A羧化酶(Acetyl-CoA carboxylase,ACC)的活性变化以及游离脂肪酸含量变化,以及二者的相关性.[方法]对来自不同地区、不同类型的油莎豆进行种植,利用植物乙酰辅酶A羧化酶(ACC)酶联免疫分析(ELISA)试剂盒和植物(Plant)游离脂肪酸(FFA) ELISA检测试剂盒测定其五个生育阶段(苗期、分蘖前期、分蘖期、分蘖后期、成熟期)叶片中乙酰辅酶A羧化酶活性以及油莎豆叶片中游离脂肪酸含量,并进行相关性分析.[结果]不同品种油莎豆叶片中乙酰辅酶A羧化酶活性的变化趋势未见一致规律性,不同品种油莎豆叶片中游离脂肪酸含量的变化也未见一致的规律性;乙酰辅酶A羧化酶活性与游离脂肪酸含量却呈现极显著或显著正相关关系.[结论]不同品种油莎豆叶片中乙酰辅酶A羧化酶的活性无确定范围,无一致的规律性,油莎豆叶片中乙酰辅酶A羧化酶的活性大小对游离脂肪酸合成的含量高低具有一定的作用.

  10. Small rocket research and technology

    Science.gov (United States)

    Schneider, Steven; Biaglow, James

    1993-01-01

    Small chemical rockets are used on nearly all space missions. The small rocket program provides propulsion technology for civil and government space systems. Small rocket concepts are developed for systems which encompass reaction control for launch and orbit transfer systems, as well as on-board propulsion for large space systems and earth orbit and planetary spacecraft. Major roles for on-board propulsion include apogee kick, delta-V, de-orbit, drag makeup, final insertions, north-south stationkeeping, orbit change/trim, perigee kick, and reboost. The program encompasses efforts on earth-storable, space storable, and cryogenic propellants. The earth-storable propellants include nitrogen tetroxide (NTO) as an oxidizer with monomethylhydrazine (MMH) or anhydrous hydrazine (AH) as fuels. The space storable propellants include liquid oxygen (LOX) as an oxidizer with hydrazine or hydrocarbons such as liquid methane, ethane, and ethanol as fuels. Cryogenic propellants are LOX or gaseous oxygen (GOX) as oxidizers and liquid or gaseous hydrogen as fuels. Improved performance and lifetime for small chemical rockets are sought through the development of new predictive tools to understand the combustion and flow physics, the introduction of high temperature materials to eliminate fuel film cooling and its associated combustion inefficiency, and improved component designs to optimize performance. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Results indicate that modeling of the injector and combustion process in small rockets needs improvement. High temperature materials require the development of fabrication processes, a durability data base in both laboratory and rocket environments, and basic engineering property data such as strength, creep, fatigue, and work hardening properties at both room and elevated temperature. Promising materials under development include iridium-coated rhenium and a

  11. Small Bodies, Big Discoveries: NASA's Small Bodies Education Program

    Science.gov (United States)

    Mayo, L.; Erickson, K. J.

    2014-12-01

    2014 is turning out to be a watershed year for celestial events involving the solar system's unsung heroes, small bodies. This includes the close flyby of comet C/2013 A1 / Siding Spring with Mars in October and the historic Rosetta mission with its Philae lander to comet 67P/Churyumov-Gerasimenko. Beyond 2014, the much anticipated 2015 Pluto flyby by New Horizons and the February Dawn Mission arrival at Ceres will take center stage. To deliver the excitement and wonder of our solar system's small bodies to worldwide audiences, NASA's JPL and GSFC education teams in partnership with NASA EDGE will reach out to the public through multiple venues including broadcast media, social media, science and math focused educational activities, observing challenges, interactive visualization tools like "Eyes on the Solar System" and more. This talk will highlight NASA's focused education effort to engage the public in small bodies mission science and the role these objects play in our understanding of the formation and evolution of the solar system.

  12. Small is beautiful: models of small neuronal networks

    Science.gov (United States)

    Lamb, Damon G; Calabrese, Ronald L

    2013-01-01

    Modeling has contributed a great deal to our understanding of how individual neurons and neuronal networks function. In this review, we focus on models of the small neuronal networks of invertebrates, especially rhythmically active CPG networks. Models have elucidated many aspects of these networks, from identifying key interacting membrane properties to pointing out gaps in our understanding, for example missing neurons. Even the complex CPGs of vertebrates, such as those that underlie respiration, have been reduced to small network models to great effect. Modeling of these networks spans from simplified models, which are amenable to mathematical analyses, to very complicated biophysical models. Some researchers have now adopted a population approach, where they generate and analyze many related models that differ in a few to several judiciously chosen free parameters; often these parameters show variability across animals and thus justify the approach. Models of small neuronal networks will continue to expand and refine our understanding of how neuronal networks in all animals program motor output, process sensory information and learn. PMID:22364687

  13. Small is beautiful: models of small neuronal networks.

    Science.gov (United States)

    Lamb, Damon G; Calabrese, Ronald L

    2012-08-01

    Modeling has contributed a great deal to our understanding of how individual neurons and neuronal networks function. In this review, we focus on models of the small neuronal networks of invertebrates, especially rhythmically active CPG networks. Models have elucidated many aspects of these networks, from identifying key interacting membrane properties to pointing out gaps in our understanding, for example missing neurons. Even the complex CPGs of vertebrates, such as those that underlie respiration, have been reduced to small network models to great effect. Modeling of these networks spans from simplified models, which are amenable to mathematical analyses, to very complicated biophysical models. Some researchers have now adopted a population approach, where they generate and analyze many related models that differ in a few to several judiciously chosen free parameters; often these parameters show variability across animals and thus justify the approach. Models of small neuronal networks will continue to expand and refine our understanding of how neuronal networks in all animals program motor output, process sensory information and learn.

  14. General Information about Small Cell Lung Cancer

    Science.gov (United States)

    ... Cancer Prevention Lung Cancer Screening Research Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Small Cell Lung Cancer Go to Health Professional Version Key Points Small ...

  15. Stages of Small Cell Lung Cancer

    Science.gov (United States)

    ... Cancer Prevention Lung Cancer Screening Research Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Small Cell Lung Cancer Go to Health Professional Version Key Points Small ...

  16. Treatment Option Overview (Small Cell Lung Cancer)

    Science.gov (United States)

    ... Cancer Prevention Lung Cancer Screening Research Small Cell Lung Cancer Treatment (PDQ®)–Patient Version General Information About Small Cell Lung Cancer Go to Health Professional Version Key Points Small ...

  17. Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency.

    Science.gov (United States)

    Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-11-01

    Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants.

  18. C4 Photosynthetic Gene Expression in Light- and Dark-Grown Amaranth Cotyledons.

    Science.gov (United States)

    Wang, J. L.; Long, J. J.; Hotchkiss, T.; Berry, J. O.

    1993-08-01

    The patterns of expression for genes encoding several C4 photosynthetic enzymes were examined in light-grown and dark-grown (etiolated) cotyledons of amaranth (Amaranthus hypochondriacus), a dicotyledonous C4 plant. The large subunit and small subunit of ribulose-1,5-bisphosphate carboxylase (RuBPCase), phosphoenolpyruvate carboxylase (PEPCase), and pyruvate orthophosphate dikinase (PPdK) were all present in the cotyledons by d 2 after planting when the seedlings first emerged from the seed coat. Kranz anatomy was apparent in light-grown cotyledons throughout development, and the overall patterns of C4 gene expression were similar to those recently described for developing amaranth leaves (J.L. Wang, D.F. Klessig, J.O. Berry [1992] Plant Cell 4: 173-184). RuBPCase mRNA and proteins were present in both bundle sheath and mesophyll cells in a C3-like pattern during early development and became progressively more localized to bundle sheath cells in the C4-type pattern as the cotyledons expanded over 2 to 7 d. PEPCase and PPdK polypeptides were localized to mesophyll cells throughout development, even though PEPCase transcripts were detected in both bundle sheath and mesophyll cells. Kranz anatomy also developed in cotyledons grown in complete darkness. In 7-d-old dark-grown cotyledons, RuBPCase, PPdK, and PEPCase were all localized to the appropriate cell types, although at somewhat lower levels than in light-grown cotyledons. These findings demonstrate that the leaves and postembryonic cotyledons of amaranth undergo common developmental programs of C4 gene expression during maturation. Furthermore, light is not required for the cell-type-specific expression of genes encoding RuBPCase and other photosynthetic enzymes in this dicotyledonous C4 plant. PMID:12231890

  19. Propulsion Challenges for Small Spacecraft: 2005

    Institute of Scientific and Technical Information of China (English)

    Vadim Zakirov; LI Luming

    2006-01-01

    Small (<100 kg) spacecrafts are being developed in many countries but their propulsion systems still have many challenges. Although there is demand for small spacecraft propulsion, the number of missions at present is small due to several commercial and technical reasons. Poor performance of existing small spacecraft propulsion systems is one of the main reasons for the small number of missions. Several reasons are given for the poor performance of existing small spacecraft propulsion. Suggested improvements focus on small spacecraft and propulsion hardware mass optimization rather than on specific impulse enhancement. Propellantless propulsion systems are also recommended for small spacecraft interplanetary missions.

  20. Structural analysis of CsoS1A and the protein shell of the Halothiobacillus neapolitanus carboxysome.

    Directory of Open Access Journals (Sweden)

    Yingssu Tsai

    2007-06-01

    Full Text Available The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO2 fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/oxygenase (RuBisCO and carbonic anhydrase. The outer shell of the carboxysome is reminiscent of a viral capsid, being constructed from many copies of a few small proteins. Here we describe the structure of the shell protein CsoS1A from the chemoautotrophic bacterium Halothiobacillus neapolitanus. The CsoS1A protein forms hexameric units that pack tightly together to form a molecular layer, which is perforated by narrow pores. Sulfate ions, soaked into crystals of CsoS1A, are observed in the pores of the molecular layer, supporting the idea that the pores could be the conduit for negatively charged metabolites such as bicarbonate, which must cross the shell. The problem of diffusion across a semiporous protein shell is discussed, with the conclusion that the shell is sufficiently porous to allow adequate transport of small molecules. The molecular layer formed by CsoS1A is similar to the recently observed layers formed by cyanobacterial carboxysome shell proteins. This similarity supports the argument that the layers observed represent the natural structure of the facets of the carboxysome shell. Insights into carboxysome function are provided by comparisons of the carboxysome shell to viral capsids, and a comparison of its pores to the pores of transmembrane protein channels.

  1. Remotely sensed small reservoir monitoring

    Science.gov (United States)

    Eilander, Dirk; Annor, Frank; Iannini, Lorenzo; van de Giesen, Nick

    2013-04-01

    A new 'growing' maximum likelihood classification algorithm for small reservoir delineation has been developed and is tested with Radarsat-2 data for reservoirs in the semi-arid Upper East Region, Ghana. The delineation algorithm is able to find the land-water boundary from SAR imagery for different weather and environmental conditions. As such, the algorithm allows for remote sensed operational monitoring of small reservoirs. Multipurpose small reservoirs (1-100 ha) are important for many livelihoods in rural semi-arid West Africa. In order to manage and plan these reservoirs and to assess their hydrological impact at a river basin scale, it is important to monitor their water storage fluctuation. Several studies on remotely sensed reservoir mapping have recently been published, but no single method yields good results for all weather and environmental conditions. Detection of small reservoirs from optical satellite imagery using supervised maximum likelihood classification is a well proved method. The application of this method for the monitoring of small reservoirs is however limited because of its dependence on cloud-free day-acquisitions. Delineation from SAR images is promising, but because of difficulties with wind induced Bragg-scattering and low contrast between the water surface and the dried-out surroundings at the end of the dry season, only quasi manual methods have been applied successfully. A smart combination of optical satellite based detection combined with a delineation method for SAR imagery is proposed. From the optical satellite based small reservoir detection the reservoir window is determined in which the 'growing' maximum likelihood classification on SAR images is performed. A water-class seed and land-class seed are implemented and grown dependent on the likelihood of a pixel to belong to one class. The likelihood is calculated based on the probability distributions of the growing land and water populations. Combinations of single

  2. Small-for-sizesyndromeinlivingdonorliver transplantation

    Institute of Scientific and Technical Information of China (English)

    Shintaro Yagi; Shinji Uemoto

    2012-01-01

    When the graft volume is too small to satisfy the recipient's metabolic demand, the recipient may thus experience small-for-size syndrome (SFSS). Because the occurrence of SFSS is determined by not only the liver graft volume but also a combination of multiple negative factors, the deifnitions of small-for-size graft (SFSG) and SFSS are different in each institute and at each time. In the clinical setting, surgical inlfow modulation and maximizing the graft outlfow are keys to overcoming SFSS. Accordingly, relatively smaller-sized grafts can be used with surgical modiifcation and pharmacological manipulation targeting portal circulation and liver graft quality. Therefore, the focus of the SFSG issue is now shifting from how to obtain a larger graft from the living donor to how to manage the use of a smaller graft to save the recipient, considering donor safety to be a priority.

  3. Small satellite radiometric measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Weber, P.G.

    1992-01-01

    A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth`s radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

  4. Small black holes on cylinders

    International Nuclear Information System (INIS)

    We find the metric of small black holes on cylinders, i.e. neutral and static black holes with a small mass in d-dimensional Minkowski space times a circle. The metric is found using an ansatz for black holes on cylinders proposed in J. High Energy Phys. 05, 032 (2002). We use the new metric to compute corrections to the thermodynamics which is seen to deviate from that of the (d+1)-dimensional Schwarzschild black hole. Moreover, we compute the leading correction to the relative binding energy which is found to be non-zero. We discuss the consequences of these results for the general understanding of black holes and we connect the results to the phase structure of black holes and strings on cylinders

  5. Small Spacecraft for Planetary Science

    Science.gov (United States)

    Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

    2016-07-01

    As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (sustain a broad range of planetary environments (i.e., radiations, temperatures, limited power generation) and offer long-range telecommunication performance on a par with science needs. Other capabilities needed for planetary missions, such as fine attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

  6. Going global - growing small businesses

    International Nuclear Information System (INIS)

    The Going Global Energy Steering Committee was established to help small and medium-sized Canadian enterprises to compete in the electrical power industry in the Asia-Pacific region primarily, but also in Eastern Europe and Latin America. The aim is to provide market intelligence, and help with forming consortia for financing. A small to medium-sized business can be defined as one with 50 to 500 employees. Big businesses no longer have the same competitive advantages that they once had, because automated systems can make short production runs just as cost-effective as long ones, and because computerization, automation and rising productivity mean that fewer workers are required than formerly

  7. Trust Propagation in Small Worlds

    DEFF Research Database (Denmark)

    Gray, Elizabeth; Seigneur, Jean-Marc; Chen, Yong;

    2003-01-01

    The possibility of a massive, networked infrastructure of diverse entities partaking in collaborative applications with each other increases more and more with the proliferation of mobile devices and the development of ad hoc networking technologies. In this context, traditional security measures...... do not scale well. We aim to develop trust-based security mechanisms using small world concepts to optimise formation and propagation of trust amongst entities in these vast networks. In this regard, we surmise that in a very large mobile ad hoc network, trust, risk, and recommendations can...... be propagated through relatively short paths connecting entities. Our work describes the design of trust-formation and risk-assessment systems, as well as that of an entity recognition scheme, within the context of the small world network topology....

  8. Unveiling small sphere's scattering behavior

    CERN Document Server

    Tzarouchis, Dimitrios C; Sihvola, Ari

    2016-01-01

    A classical way for exploring the scattering behavior of a small sphere is to approximate Mie coefficients with a Taylor series expansion. This ansatz delivered a plethora of insightful results, mostly for small spheres supporting electric localized plasmonic resonances. However, many scattering aspects are still uncharted, especially for the case of magnetic resonances. Here, an alternative system ansatz is proposed based on the Pad\\'e approximants for the Mie coefficients. The extracted results reveal new aspects, such as the existence of a self-regulating radiative damping mechanism for the first magnetic resonance. Hence, a systematic way of exploring the scattering behavior is introduced, sharpening our understanding about sphere's scattering behavior and its emergent functionalities.

  9. Parton distributions at small x

    International Nuclear Information System (INIS)

    We perform a next-to-leading order quantum chromodynamics (QCD) analysis of the recent data for deep-inelastic lepton-nucleon scattering and related processes, in which we pay particular attention to the forms of the parton distributions at very small x. We discuss in detail, and we incorporate in the analysis, the theoretical QCD results leading to the singular x-1/2 type of behaviour of the gluon and sea quark distributions, as well as the modifications due to shadowing effects. We find the QCD shadowing corrections are significant for x ''approx -3 even though the parton distributions are below their saturation limit. We give predictions for the structure functions F2 and FL accessible at HERA, and for W and Z productions up to linear hard core pinch devices (LHC) and superconducting supercollider (SSC) energies. We discuss the possibility of experiments at these colliders probing the parton distributions in the very small x region. (author)

  10. Deployable Reflectors for Small Satellites

    OpenAIRE

    Barrett, Rory; Taylor, Robert; Keller, Philip; Codell, Dana; Adams, Larry

    2007-01-01

    A key limitation for future Small Satellite communications and radar missions will be available antenna reflector aperture. Two types of reflectors are dominant for satellite RF systems today, rigid, single-piece reflectors and deployable mesh reflectors. Single-piece reflectors are limited to the aperture that fits inside a launch vehicle without packaging the reflective surface. Mesh reflectors have become the workhorse of the deployable reflector market, however these reflectors are expens...

  11. Metagenomic small molecule discovery methods

    OpenAIRE

    Charlop-Powers, Zachary; Milshteyn, Aleksandr; Brady, Sean F

    2014-01-01

    Metagenomic approaches to natural product discovery provide the means of harvesting bioactive small molecules synthesized by environmental bacteria without the requirement of first culturing these organisms. Advances in sequencing technologies and general metagenomic methods are beginning to provide the tools necessary to unlock the unexplored biosynthetic potential encoded by the genomes of uncultured environmental bacteria. Here, we highlight recent advances in sequence- and functional- bas...

  12. Small gauge vitrectomy: Recent update

    OpenAIRE

    Sumeet Khanduja; Ashish Kakkar; Saptrishi Majumdar; Rajpal Vohra; Satpal Garg

    2013-01-01

    Small gauge vitrectomy, also known as minimally invasive vitreous surgery (MIVS), is a classic example of progress in biomedical engineering. Disparity in conjunctival and scleral wound location and reduction in wound diameter are its core principles. Fluidic changes include increased pressure head loss with consequent reduction in infusional flow rate and use of higher aspiration vacuum at the cutter port. Increase An increase in port open/port closed time maintains an adequate rate of vitre...

  13. Small Business Innovations (Robotic Wrist)

    Science.gov (United States)

    1991-01-01

    Under a Langley Research Center Small Business Innovation Research (SBIR) contract, Ross-Hime Designs, Inc. Minneapolis, MN, developed the Omni-Wrist actuator, which has a 25-pound capacity, 180 degrees of pitch/yaw, and 360 degrees of roll. Company literature calls it "the first successful singularity-free high-precision (robotic) wrist." Applications include spray painting, sealing, ultrasonic testing, welding and a variety of nuclear industry, aerospace and military uses.

  14. Small Business Innovations (Fiber Optics)

    Science.gov (United States)

    1991-01-01

    Foster-Miller, Inc. Waltham, MA developed the In-Situ Fiber Optic Polymer Reaction Monitor which could lead to higher yields and lower costs in complex composite manufacturing. The monitor, developed under a Small Business Innovation Research (SBIR) contract with Langley Research Center, uses an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. It is the first analytical system capable of directly measuring the chemistry of advanced composite materials.

  15. Small Business Innovations (Integrated Database)

    Science.gov (United States)

    1992-01-01

    Because of the diversity of NASA's information systems, it was necessary to develop DAVID as a central database management system. Under a Small Business Innovation Research (SBIR) grant, Ken Wanderman and Associates, Inc. designed software tools enabling scientists to interface with DAVID and commercial database management systems, as well as artificial intelligence programs. The software has been installed at a number of data centers and is commercially available.

  16. Twisted Yangians of small rank

    Science.gov (United States)

    Guay, Nicolas; Regelskis, Vidas; Wendlandt, Curtis

    2016-04-01

    We study quantized enveloping algebras called twisted Yangians associated with the symmetric pairs of types CI, BDI, and DIII (in Cartan's classification) when the rank is small. We establish isomorphisms between these twisted Yangians and the well known Olshanskii's twisted Yangians of types AI and AII, and also with the Molev-Ragoucy reflection algebras associated with symmetric pairs of type AIII. We also construct isomorphisms with twisted Yangians in Drinfeld's original presentation.

  17. Small intestinal bacterial overgrowth syndrome

    Institute of Scientific and Technical Information of China (English)

    Jan; Bures; Jiri; Cyrany; Darina; Kohoutova; Miroslav; Frstl; Stanislav; Rejchrt; Jaroslav; Kvetina; Viktor; Vorisek; Marcela; Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There...

  18. Design of small table saws

    OpenAIRE

    Stuchlík, Petr

    2016-01-01

    The main aim of this thesis is the engineering design of a small table circular saw according to the specified parameters. At first, the types of machines available on the market are named and analyzed in detail. Afterwards, the engineering design of the machine is created. The following part is concerned with the individual parts,, tilting of the saw blade, maximum cutting pull through linkage with motion screw and checking of deformation of he critical parts of the machine. The previously s...

  19. The small world of psychopathology

    OpenAIRE

    Denny Borsboom; Cramer, Angélique O. J.; Schmittmann, Verena D.; Sacha Epskamp; Waldorp, Lourens J.

    2011-01-01

    BACKGROUND: Mental disorders are highly comorbid: people having one disorder are likely to have another as well. We explain empirical comorbidity patterns based on a network model of psychiatric symptoms, derived from an analysis of symptom overlap in the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). PRINCIPAL FINDINGS: We show that a) half of the symptoms in the DSM-IV network are connected, b) the architecture of these connections conforms to a small world structure, fe...

  20. Rhapsody on small processor platforms

    OpenAIRE

    Andersson, Per-Oskar

    2008-01-01

    Rhapsody is a Model-Driven Development (MDD) tool for embedded and real-time system design. The purpose of this thesis is to determine if Rhapsody can be used for software development on small processor platforms such as the Atmel AVR. Rhapsody is normally used on platforms running an operating system. Therefore certain adaptations are needed in order to use it on platforms without an operating system. These adaptations and their affect on the usability of the tool, advantages and disadvantag...

  1. Manual on small earth dams

    OpenAIRE

    Stephens, Tim

    2015-01-01

    "This publication fills a void of practical guidelines for the construction of small earth dams. It presents readers with sound, reliable and practical source material to improve dam siting and design capacity in rural areas, to introduce a beneficiary and gender sensitive approach and to enhance safety and competence in construction. A section also provides convenient guidance on costing, drafting tenders and awarding contracts. The manual is primarily aimed at technicians and others with kn...

  2. Evolution of small prokaryotic genomes

    OpenAIRE

    Martínez-Cano, David J.; Reyes-Prieto, Mariana; Martínez-Romero, Esperanza; Partida-Martínez, Laila P.; Latorre, Amparo; Moya, Andrés; Delaye, Luis

    2015-01-01

    As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ∼800 genes as well as endosymbiotic bacteria with as few as ∼140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent ...

  3. Evolution of small prokaryotic genomes

    OpenAIRE

    David José Martínez-Cano; Mariana eReyes-Prieto; Esperanza eMartinez-Romero; Laila Pamela Partida-Martinez; Amparo eLatorre; Andres eMoya; Luis eDelaye

    2015-01-01

    As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent ...

  4. Desmoplastic small round cell tumour

    Energy Technology Data Exchange (ETDEWEB)

    Tan, T.H.L. [North District Hospital, Fanling, Kowloon (Hong Kong). Radiology Department; Ong, K.L. [Prince of Wales Hospital, Shatin, Kowloon (Hong Kong). Accident and Emergency Department; Au, Y.M.C. [Princess Margarete Hospital, Kowloon, (Hong Kong). Department of Radiology

    1998-11-01

    The present report describes a rare case of primary desmoplastic small cell tumour of the recto-sigmoid colon with hepatic metastases and lymphadenopathy. There are no pathognomonic radiological features and often their features overlap with other diseases including lymphoma. Histology is necessary to confirm this diagnosis. Unfortunately despite aggressive therapy, the prognosis for this disease is poor. Copyright (1998) Blackwell Science Pty Ltd 8 refs., 1 fig.

  5. Implantable telemetry for small animals

    Science.gov (United States)

    1982-03-01

    A series of totally implantable telemetry devices for use in measuring deep body parameters in small animals were developed. Under a collaborative agreement with NASA, several of these systems; the continuous wave Doppler ultrasonic flowmeter, the multichannel telemetry system, and the inductively-powered dual channel cardiac pacer were evaluated in a series of ten mongrel dogs (15 to 20 kg.). These systems were used to measure ascending aortic and coronary blood flow, aortic pressure, and subcutaneous EKG.

  6. Chronic Hemodialysis in Small Children.

    Science.gov (United States)

    Novljan, Gregor; Rus, Rina R; Premru, Vladimir; Ponikvar, Rafael; Battelino, Nina

    2016-06-01

    When peritoneal dialysis is inapplicable, chronic hemodialysis (HD) becomes the only available treatment option in small children. Due to small patient size, central venous catheters (CVC) are mainly used for vascular access. Over the past 4 years, four children weighing less than 15 kg received chronic HD in our unit. A total of 848 dialysis sessions were performed. Altogether, 21 catheters were inserted. In all but one occasion, uncuffed catheters were used. Catheter revision was performed 15 times during the study period, either due to infection or catheter malfunction. The median number of catheter revisions and the median line survival was 3.0/patient-year and 53 days (range; 6-373 days), respectively. There were 14 episodes of catheter related infections requiring 11 CVC revisions (78.6%). The median rate of line infections was 2.8/patient-year. Chronic HD in small children is demanding and labor intensive. Issues pertain mainly to CVCs and limit its long-term use. PMID:27312919

  7. Superconductivity of small metal grains

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Renrong; CHEN; Zhiqian; ZHU; Shunquan

    2005-01-01

    The formulas of the energy gap and superconducting critical temperature appropriate for systems with both odd and even number of electrons are derived; the bases of the derivations are BCS theory and energy level statistics. Numerical results qualitatively agree with the experimental phenomena. i.e., the superconductivity of small metallic grains will first enhance then decrease to zero when the grain are getting smaller and smaller. The calculations indicate that the above phenomena happen in the metallic grains belonging to Gaussian Orthogonal Ensemble (GOE) and Gaussian Unitary ensemble (GUE) with zero spin; The superconductivity of small metallic grains in Gaussian Symplectic Ensemble (GSE) will monotonically decrease to zero with the decreasing of the grain size. The analyses suggest that the superconductivity enhancements come from pairing and the balance of the strengths between spin-orbital coupling and external magnetic field. In order to take the latter into account, it is necessary to include the level statistics given by Random Matrix Theory (RMT) in describing small metallic grains.

  8. Small Break Air Ingress Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Soo Kim

    2011-09-01

    The small break air-ingress experiment, described in this report, is designed to investigate air-ingress phenomena postulated to occur in pipes in a very high temperature gas-cooled reactor (VHTRs). During this experiment, air-ingress rates were measured for various flow and break conditions through small holes drilled into a pipe of the experimental apparatus. The holes were drilled at right angles to the pipe wall such that a direction vector drawn from the pipe centerline to the center of each hole was at right angles with respect to the pipe centerline. Thus the orientation of each hole was obtained by measuring the included angle between the direction vector of each hole with respect to a reference line anchored on the pipe centerline and pointing in the direction of the gravitational force. Using this reference system, the influence of several important parameters on the air ingress flow rate were measured including break orientation, break size, and flow velocity . The approach used to study the influence of these parameters on air ingress is based on measuring the changes in oxygen concentrations at various locations in the helium flow circulation system as a function of time using oxygen sensors (or detectors) to estimate the air-ingress rates through the holes. The test-section is constructed of a stainless steel pipe which had small holes drilled at the desired locations.

  9. Evolution of small prokaryotic genomes

    Directory of Open Access Journals (Sweden)

    David José Martínez-Cano

    2015-01-01

    Full Text Available As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokaryotes have evolved diverse strategies for living with reduced gene sets inside a host-defined medium. These include utilization of host-encoded functions (some of them coded by genes acquired by gene transfer from the endosymbiont and/or other bacteria; metabolic complementation between co-symbionts; and forming consortiums with other bacteria within the host. Recent genome sequencing projects of intracellular mutualistic bacteria showed that previously believed universal evolutionary trends like reduced G+C content and conservation of genome synteny are not always present in highly reduced genomes. Finally, the simplified molecular machinery of some of these organisms with small genomes may be used to aid in the design of artificial minimal cells. Here we review recent genomic discoveries of the biology of prokaryotes endowed with small gene sets and discuss the evolutionary mechanisms that have been proposed to explain their peculiar nature.

  10. 78 FR 48537 - Small Business Innovation Research and Small Business Technology Transfer Programs...

    Science.gov (United States)

    2013-08-08

    ... ADMINISTRATION Small Business Innovation Research and Small Business Technology Transfer Programs... Administration (SBA) is publishing the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) program Commercialization Benchmark for the 11 participating agencies for public...

  11. 78 FR 59798 - Small Business Subcontracting: Correction

    Science.gov (United States)

    2013-09-30

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION 13 CFR Part 125 RIN 3245-AG22 Small Business Subcontracting: Correction AGENCY: U.S. Small..., 2013 (78 FR 42391). The document amended SBA's regulations governing small business subcontracting...

  12. 78 FR 42391 - Small Business Subcontracting

    Science.gov (United States)

    2013-07-16

    ... ADMINISTRATION 13 CFR Parts 121 and 125 RIN 3245-AG22 Small Business Subcontracting AGENCY: U.S. Small Business Administration. ACTION: Final rule. SUMMARY: The U.S. Small Business Administration (SBA or Agency) is amending.... FOR FURTHER INFORMATION CONTACT: Dean Koppel, U.S. Small Business Administration, Office of...

  13. Small Group Communication in the 1980's.

    Science.gov (United States)

    Neer, Michael R., Ed.

    1981-01-01

    This special edition of "Communication" brings together the work of nine leading scholars of small group communication. The following topics are discussed: (1) small group communication research in the 1980s; (2) unanswered questions in research on communication in the small group; (3) emerging trends in small group research; (4) structure in…

  14. 76 FR 61626 - Small Business Subcontracting

    Science.gov (United States)

    2011-10-05

    ... ADMINISTRATION 13 CFR Parts 121 and 125 RIN 3245-AG22 Small Business Subcontracting AGENCY: U.S. Small Business Administration. ACTION: Proposed rule. SUMMARY: The U.S. Small Business Administration (SBA or Agency) is... submissions: Dean Koppel, U.S. Small Business Administration, Office of Government Contracting, 409...

  15. Japanese Small Type Coastal Whaling

    Directory of Open Access Journals (Sweden)

    Sue Fisher

    2016-07-01

    Full Text Available 2016 marks the 70th anniversary of the International Convention for the Regulation of Whaling (ICRW as well as the 30th anniversary of the International Whaling Commission’s (IWC moratorium on commercial whaling. It also marks three decades of effort by Japan to overturn this ban. Its strategy to circumvent the moratorium by issuing permits to kill protected whales for scientific research is famous—even the subject of a 2014 lawsuit at the International Court of Justice. Less well known is Japan’s strategy to overturn the ban by persuading the Commission to authorise a category of commercial whaling known as Small Type Coastal Whaling (STCW that is conducted on minke and other small whales in Japanese waters but has never been regulated, or even formally recognised, by the IWC. For three decades Japan has sought STCW catch limits for four communities which it claims are still suffering distress as a result of the moratorium. While the Commission has rejected each proposal, mainly citing concerns that the commercial nature and purpose of STCW violates the moratorium, Japan has persisted, exhibiting great flexibility in its approach. Its tactics changed significantly in 2014; it no longer denied (or defended the commerciality of the hunt, but argued that it is irrelevant since it sought only a small exemption to the moratorium which would remain intact for all other populations. This is a perspective on Japan’s evolving STCW strategy and the risk that lifting, or modifying, the moratorium would pose to the conservation of whales.

  16. GEF small grants programme - overview

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    This paper describes the GEF small grants program which seeks to enhance the role of households and communities in conserving global biodiversity, mitigating global climate change, and protecting international waters. Grants up to $50k have been granted for projects in 33 countries, with plans for 12 other countries. The author describes the framework that the program works under, and the methodology followed in developing and planning projects. The approach to climate change concerns is to emphasize the development of non-carbon energy development activities to provide energy sources and economic development.

  17. Small Bowel Imaging: an Update.

    Science.gov (United States)

    Rimola, Jordi; Panés, Julián

    2016-07-01

    Bowel imaging had experienced relevant technical advances during the last decade. The developments in the field of cross-sectional imaging had a particular impact on the assessment of Crohn's disease. The purpose of this manuscript is to provide a review of the main progress of cross-sectional imaging in the assessment of Crohn's disease and other small bowel diseases with relevance in clinical practice and in research. Also, we outline the technical advances, trends, and potential contributions of new technological cross-sectional imaging improvements that may have potential impact and contribution in the near future. PMID:27315216

  18. Minimum Q Electrically Small Antennas

    DEFF Research Database (Denmark)

    Kim, O. S.

    2012-01-01

    Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for the stored energies obtained through the vector spherical wave theory, it is shown that a magnetic-coated metal core reduces the internal stored energy of both TM1m and TE1m modes simultaneously, so that a self-resonant antenna with the Q approaching the fundamental minimum is created. Numerical results...

  19. Small Bowel Review: Part II

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    1996-01-01

    Full Text Available Major scientific advances have been made over the past few years in the areas of small bowel physiology, pathology, microbiology and clinical sciences. Over 1000 papers have been reviewed and a selective number are considered here. Wherever possible, the clinical relevance of these advances have been identified. Topics discussed are enterocyte proliferation and growth factors; amino acids, peptides and allergies; motility; salt and water absorption and secretion – diarrhea; vitamins and minerals; early development and ageing of the intestine; and ethanol effects.

  20. Small helical flux compression amplifiers

    International Nuclear Information System (INIS)

    Small, explosively compressed, magnetic flux transducers with many closely spaced helical turns are investigated theoretically and experimentally. The analysis is limited to linear operation, but takes into account load influence, proximity effects, and switching delays. The latter are due to retarded breakdown in the wire insulation and to the finite decay time of the magnetic field in the wire. More than 150 experiments showed considerable data scatter. Shots which exhibited low clocking and high amplification were in good agreement with the theory. The main conclusion is that device performance is limited not only by flux loss, but by flux remaining in the generator after compression

  1. Small Bowel Review: Part I

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    2000-01-01

    Full Text Available In the past year, there have been many advances in the area of small bowel physiology and pathology. More than 1500 papers were assessed in preparation for this review. Some were selected and reviewed, with a particular focus on presenting clinically useful information for the practising gastroenterologist. Relevant review articles have been highlighted, and important clinical learning points have been stressed. The topics are varied in scope, and wherever possible show a logical progression from basic physiology to pathophysiology to clinical disorders and management.

  2. Small angle scattering and polymers

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, J.P. [Laboratoire Leon Brillouin (LLB) - Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1996-12-31

    The determination of polymer structure is a problem of interest for both statistical physics and industrial applications. The average polymer structure is defined. Then, it is shown why small angle scattering, associated with isotopic substitution, is very well suited to the measurement of the chain conformation. The corresponding example is the old, but pedagogic, measurement of the chain form factor in the polymer melt. The powerful contrast variation method is illustrated by a recent determination of the concentration profile of a polymer interface. (author) 12 figs., 48 refs.

  3. Small intestinal tophus mimicking tumor

    Directory of Open Access Journals (Sweden)

    Pragya Katoch

    2014-03-01

    Full Text Available A 72 year old male with hypertension, diabetes mellitus type 2 and previous gouty arthritis presented with weight loss, nausea, and vomiting. Ultrasound and CT scanning of the abdomen revealed a circumscribed tumor mass of the jejunum, 3.7 cm in diameter. Microscopic examination of the resected jejunum revealed the tumor to be a gouty tophus. To the best of our knowledge, three cases of tophi in the large intestine have previously been reported but none in the small intestine.

  4. Fuzzy Small Submodule and Jacobson -Radical

    OpenAIRE

    Saifur Rahman; Helen K. Saikia

    2011-01-01

    Using the notion of fuzzy small submodules of a module, we introduce the concept of fuzzy coessential extension of a fuzzy submodule of a module. We attempt to investigate various properties of fuzzy small submodules of a module. A necessary and sufficient condition for fuzzy small submodules is established. We investigate the nature of fuzzy small submodules of a module under fuzzy direct sum. Fuzzy small submodules of a module are characterized in terms of fuzzy quotient modules. This chara...

  5. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of 14{sub C}O2; Estudio de las propiedades de la Ribulosa-1,5-Difosfato Carboxilasa/Oxigenasa de maiz (Zea Mais) y de trigo (Triticum Aestivum), por incorporacion de CO{sub 2} marcado con 14{sub C}O2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. D.; Saez, R. M.

    1982-07-01

    After a bibliographic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14{sup C}O{sub 3}HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC{sub 2} from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg{sup 2} concentration and determination of the Km{sub (s)} from CO{sub 2} and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO{sub 2}2 and Mg{sup 2}. (Author) 64 refs.

  6. Railgun launch of small bodies

    Energy Technology Data Exchange (ETDEWEB)

    Drobyshevski, E.M.; Zhukov, B.G.; Sakharov, V.A. [Russian Academy of Sciences, St. Petersburg (Russian Federation). Ioffe Physico-Technical Inst.

    1995-01-01

    The small body launching using gas or plasma faces the fundamental problem caused by excess energy loss due to great wall surface/volume of the barrel ratio. That is why the efficiency of the plasma armature (PA) railgun acceleration is maximum for 8--10 mm-size bodies and drops as their size decreases. For the nuclear fusion applications, where {number_sign}1--2 mm-size pellets at 5--10 km/s velocity are desirable, one is forced to search for compromise between the body size (3--4 mm) and its velocity (3 km/s). Under these conditions, EM launchers did not demonstrate an advantage over the light-gas guns. When elaborating the {number_sign}1 mm railgun, the authors made use of the ideology of the body launching at constant acceleration close to the body strength or the electrode skin-layer explosion limits. That shortened the barrel length sufficiently. The system becomes highly compact thus permitting rapid test of new operation modes and different modifications of the design including the magnetic field augmentation. As a result of these refinements, the difficulties caused by the catastrophic supply of mass ablated from the electrodes were overcome and regimes of {number_sign}1 mm body non-sabot speed-up to 4.5 km/s were found. Potentialities of the small system created are far from being exhausted.

  7. Small gauge vitrectomy: Recent update

    Directory of Open Access Journals (Sweden)

    Sumeet Khanduja

    2013-01-01

    Full Text Available Small gauge vitrectomy, also known as minimally invasive vitreous surgery (MIVS, is a classic example of progress in biomedical engineering. Disparity in conjunctival and scleral wound location and reduction in wound diameter are its core principles. Fluidic changes include increased pressure head loss with consequent reduction in infusional flow rate and use of higher aspiration vacuum at the cutter port. Increase An increase in port open/port closed time maintains an adequate rate of vitreous removal. High Intensity Discharge (HID lamps maintain adequate illumination in spite of a decrease in the number of fiberoptic fibers. The advantages of MIVS are, a shorter surgical time, minimal conjunctival damage, and early postoperative recovery. Most complications are centered on wound stability and risk of postoperative hypotony, endophthalmitis, and port site retinal break formation. MIVS is suited in most cases, however, it can cause dehiscence of recent cataract wounds. Retraction of the infusion cannula in the suprachoroidal space may occur in eyes with scleral thinning. As a lot has been published and discussed about sutureless vitrectomy a review of this subject is necessary. A PubMed search was performed in December 2011 with terms small gauge vitrectomy, 23-gauge vitrectomy, 25-gauge vitrectomy, and 27 gauge vitrectomy, which were revised in August 2012. There were no restrictions on the date of publication but it was restricted to articles in English or other languages, if there abstracts were available in English.

  8. Small RNA in rice genome

    Institute of Scientific and Technical Information of China (English)

    王凯; 朱小蓬; 钟兰; 陈润生

    2002-01-01

    Rice has many characteristics of a model plant. The recent completion of the draft of the rice genome represents an important advance in our knowledge of plant biology and also has an important contribution to the understanding of general genomic evolution. Besides the rice genome finishing map, the next urgent step for rice researchers is to annotate the genes and noncoding functional sequences. The recent work shows that noncoding RNAs (ncRNAs) play significant roles in biological systems. We have explored all the known small RNAs (a kind of ncRNA) within rice genome and other six species sequences, including Arabidopsis, maize, yeast, worm, mouse and pig. As a result we find 160 out of 552 small RNAs (sRNAs) in database have homologs in 108 rice scaffolds, and almost all of them (99.41%) locate in intron regions of rice by gene predication. 19 sRNAs only appear in rice. More importantly, we find two special U14 sRNAs: one is located in a set of sRNA ZMU14SNR9(s) which only appears in three plants, 86% sequences of them can be compared as the same sequence in rice, Arabidopsis and maize; the other conserved sRNA XLHS7CU14 has a segment which appears in almost all these species from plants to animals. All these results indicate that sRNA do not have evident borderline between plants and animals.

  9. Management of Small Vessel Vasculitides.

    Science.gov (United States)

    Lopalco, Giuseppe; Rigante, Donato; Venerito, Vincenzo; Emmi, Giacomo; Anelli, Maria Grazia; Lapadula, Giovanni; Iannone, Florenzo; Cantarini, Luca

    2016-06-01

    Inflammation mediated by cells of the immune system and necrosis are the most striking features observed at the histologic level in patients with vasculitides, clinical entities classified according to pathologic findings involving different organs, to etiology, or to size of vessels involved. Small vessel vasculitides (SVV) are a peculiar group of systemic disorders electively involving small intraparenchymal arteries, arterioles, capillaries, or venules and leading to different levels of vascular obstruction, tissue ischemia and risk of infarction; they can be divided into anti-neutrophil cytoplasmic antibody-associated vasculitides and immune complex vasculitides. Despite the significant advances in understanding the whole disease process and pathophysiology of SVV, strong efforts are still needed to draft, share and spread guidelines in the therapeutic management of these protean disorders. After an accurate evaluation of different open or double-blind trials and cohort studies in this review, we analyze the actual medical tools suggested for treating granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, Henoch-Schönlein purpura, cryoglobulinemic vasculitis, anti-glomerular basement membrane disease and hypocomplementemic urticarial vasculitis. PMID:27118389

  10. Small Spacecraft for Planetary Science

    Science.gov (United States)

    Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

    2016-07-01

    As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (electronics, advanced manufacturing for lightweight structures, and innovative propulsion are making it possible to fly much more capable micro spacecraft for planetary exploration. While micro spacecraft, such as CubeSats, offer significant cost reductions with added capability from advancing technologies, the technical challenges for deep space missions are very different than for missions conducted in low Earth orbit. Micro spacecraft must be able to sustain a broad range of planetary environments (i.e., radiations, temperatures, limited power generation) and offer long-range telecommunication performance on a par with science needs. Other capabilities needed for planetary missions, such as fine attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

  11. Small Molecules Target Carcinogenic Proteins

    Science.gov (United States)

    Gradinaru, Claudiu

    2009-03-01

    An ingenious cellular mechanism of effecting protein localization is prenylation: the covalent attachment of a hydrophobic prenyl group to a protein that facilitates protein association with cell membranes. Fluorescence microscopy was used to investigate whether the oncogenic Stat3 protein can undergo artificial prenylation via high-affinity prenylated small-molecule binding agents and thus be rendered inactive by localization at the plasma membrane instead of nucleus. The measurements were performed on a home-built instrument capable of recording simultaneously several optical parameters (lifetime, polarization, color, etc) and with single-molecule sensitivity. A pH-invariant fluorescein derivative with double moiety was designed to bridge a prenyl group and a small peptide that binds Stat3 with high affinity. Confocal fluorescence images show effective localization of the ligand to the membrane of liposomes. Stat3 predominantly localizes at the membrane only in the presence of the prenylated ligand. Single-molecule FRET (fluorescence resonance energy transfer) between donor-labeled prenylated agents and acceptor-labeled, surface tethered Stat3 protein is used to determine the dynamic heterogeneity of the protein-ligand interaction and follow individual binding-unbinding events in real time. The data indicates that molecules can effect protein localization, validating a therapeutic design that influences protein activity via induced localization.

  12. Small crater populations on Vesta

    CERN Document Server

    Marchi, S; O'Brien, D P; Schenk, P; Mottola, S; De Sanctis, M C; Kring, D A; Williams, D A; Raymond, C A; Russell, C T

    2013-01-01

    The NASA Dawn mission has extensively examined the surface of asteroid Vesta, the second most massive body in the main belt. The high quality of the gathered data provides us with an unique opportunity to determine the surface and internal properties of one of the most important and intriguing main belt asteroids (MBAs). In this paper, we focus on the size frequency distributions (SFDs) of sub-kilometer impact craters observed at high spatial resolution on several selected young terrains on Vesta. These small crater populations offer an excellent opportunity to determine the nature of their asteroidal precursors (namely MBAs) at sizes that are not directly observable from ground-based telescopes (i.e., below ~100 m diameter). Moreover, unlike many other MBA surfaces observed by spacecraft thus far, the young terrains examined had crater spatial densities that were far from empirical saturation. Overall, we find that the cumulative power-law index (slope) of small crater SFDs on Vesta is fairly consistent with...

  13. 高脂饮食对老年大鼠骨骼肌脂肪酸含量及乙酰辅酶A羧化酶表达和活性的影响%Effects of high-fat diet on fatty acid metabolism, expression and activity of acetyl-coenzyme A carboxylase in skeletal muscle in aged rats

    Institute of Scientific and Technical Information of China (English)

    胡淑国; 宋光耀; 王敬; 高宇

    2010-01-01

    目的 探讨增龄和高脂饮食对大鼠骨骼肌脂肪酸含量及乙酰辅酶A羧化酶(acetyl-coenzyme A carboxylase,ACC)表达和活性的影响.方法 将22~24月龄雄性Wistar大鼠随机分为老年对照组和高脂组;4~5月龄大鼠作为青年对照组.老年对照组和青年对照组给基础饲料,高脂组给予高脂饲料,喂养8周.用高胰岛素-正葡萄糖钳夹实验评价各组大鼠胰岛素敏感性,用全自动生化分析仪测定骨骼肌三酰甘油,用荧光分光光度计测定骨骼肌总的长链脂酰辅酶A含量,用Western-blot方法测定骨骼肌ACC、和磷酸化ACC(P-ACC)蛋白表达.结果 (1)老年对照组空腹血糖、胰岛索和游离脂肪酸高于青年对照组,高脂组上述几项指标进一步升高,并且出现血清三酰甘油和总胆固醇水平增高;(2)老年对照组葡萄糖输注率(glucose infusion rates,GIR)低于青年对照组,高脂组GIR低于老年对照组,高脂组GIR在8周末低于4周末;(3)老年对照组骨骼肌三酰甘油及长链脂酰辅酶A含量高于青年对照组,高脂组与老年对照组比较进一步升高;(4)老年对照组与青年对照组之间、高脂组与老年对照组之间骨骼肌ACC蛋白表达均无明显变化(P>0.05);骨骼肌P-ACC蛋白水平在老年对照组低于青年对照组,高脂组与老年对照组比较进一步降低(P0.05). The protein levels of P-ACC in skeletal muscle were lower in OC group, and much lower in HF group than in YC group (P<0.05 or P<0.01). Conclusions Compared with young rats, abnormal fatty acid metabolism and insulin resistance always exist in aged rats. High-fat feeding results in a significant increase in lipid content in skeletal muscle. Alterations of ACC activity may contribute to fat accumulation in skeletal muscle and insulin resistance.

  14. Resistência de populações de capim-colchão (Digitaria ciliaris aos herbicidas inibidores da Acetil Co-A Carboxilase Resistance of crab-grass (Digitaria ciliaris populations to Acetyl-Co-A Carboxylase-inhibiting herbicides

    Directory of Open Access Journals (Sweden)

    R.F. López-Ovejero

    2005-09-01

    Full Text Available O objetivo do presente trabalho foi avaliar as populações com suspeita de ocorrência de biótipos resistentes de Digitaria ciliaris aos herbicidas inibidores da AcetilCoA Carboxilase (ACCase, por meio de curvas de dose-resposta, bem como estabelecer o grau de resistência cruzada aos herbicidas cicloexanodionas (CHD e ariloxifenoxipropionatos (APP desses biótipos. O experimento foi conduzido em casa de vegetação, utilizando-se quatro populações com suspeita de resistência (R1, R2, R3 e R4 e uma população suscetível (S. O delineamento experimental adotado foi o de blocos ao acaso, com quatro repetições, sendo os tratamentos resultado da interação fatorial entre cinco populações, três herbicidas (fluazifop-p-butil, sethoxydim e tepraloxydim e oito doses de herbicidas (0C, 0,06C, 0,125C, 0,5C, 1C, 2C, 4C e 10C, em que C é a dose comercial recomendada para cada produto. Foram realizadas avaliações de porcentagem de controle aos 28 dias após a aplicação (DAA. A partir dos resultados obtidos, conclui-se que as populações R1, R2, R3 e R4 apresentaram-se como biótipos resistentes aos herbicidas inibidores da ACCase, com diferentes níveis de resistência cruzada aos herbicidas com esse mecanismo de ação.This research aimed to verify the occurrence of resistant biotypes of crab-grass (Digitaria ciliaris to Acetyl-Co-A Carboxylase (ACCase-inhibiting herbicides through dose-response curves, as well as to establish the degree of cross resistance to the CHD and APP herbicides of these biotypes. The experiment was conducted in the greenhouse and tested four suspected resistant populations (R1, R2, R3 e R4 and a susceptible one (S. The experimental design adopted was randomized complete blocks with four replications, and the treatments were the result of a factorial interaction among five populations, three herbicides (fluazifop-p-butyl, sethoxydim and tepraloxydim, and eight rates (0C, 0.06C, 0.125C, 0.5C, 1C, 2C, 4C and 10C

  15. Small Space Launch: Origins & Challenges

    Science.gov (United States)

    Freeman, T.; Delarosa, J.

    2010-09-01

    The United States Space Situational Awareness capability continues to be a key element in obtaining and maintaining the high ground in space. Space Situational Awareness satellites are critical enablers for integrated air, ground and sea operations, and play an essential role in fighting and winning conflicts. The United States leads the world space community in spacecraft payload systems from the component level into spacecraft, and in the development of constellations of spacecraft. In the area of launch systems that support Space Situational Awareness, despite the recent development of small launch vehicles, the United States launch capability is dominated by an old, unresponsive and relatively expensive set of launchers in the Expandable, Expendable Launch Vehicles (EELV) platforms; Delta IV and Atlas V. The United States directed Air Force Space Command to develop the capability for operationally responsive access to space and use of space to support national security, including the ability to provide critical space capabilities in the event of a failure of launch or on-orbit capabilities. On 1 Aug 06, Air Force Space Command activated the Space Development & Test Wing (SDTW) to perform development, test and evaluation of Air Force space systems and to execute advanced space deployment and demonstration projects to exploit new concepts and technologies, and rapidly migrate capabilities to the warfighter. The SDTW charged the Launch Test Squadron (LTS) with the mission to develop the capability of small space launch, supporting government research and development space launches and missile defense target missions, with operationally responsive spacelift for Low-Earth-Orbit Space Situational Awareness assets as a future mission. This new mission created new challenges for LTS. The LTS mission tenets of developing space launches and missile defense target vehicles were an evolution from the squadrons previous mission of providing sounding rockets under the Rocket

  16. Amyloidosis of the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Kala, Zdenek [Department of Surgery, Faculty Hospital Brno, Jihlavska 20, 62500 Brno (Czech Republic)]. E-mail: zkala@tiscali.cz; Valek, Vlastimil [Department of Radiology, Faculty Hospital Brno, Jihlavska 20, 62500 Brno (Czech Republic)]. E-mail: v.valek@fnbrno.cz; Kysela, Petr [Department of Surgery, Faculty Hospital Brno, Jihlavska 20, 62500 Brno (Czech Republic)]. E-mail: pkysel@email.cz

    2007-07-15

    Amyloidosis is a rare disease characterized by forming pathological protein deposits - amyloid - in many organs and tissues. This decreases their functionality. The aim of this small study was to determine, whether the radiological picture of the small intestine involvement in amyloidosis is in some sense specific as sometimes described in literature giving rise to high suspicion for the disease in symptomatic patients. Material and methods: The prospective study comprising seven patients hospitalized in surgical department is presented together with a survey on the disease, its appearance in radiological imaging. All patients underwent abdominal ultrasound (ATL 5000 HDI, 7-12 MHz linear probe, no contrast enhancement, supine position), abdominal CT (Somatom Plus, Siemens, single detector, conventional abdominal CT protocol) and enteroclysis (Micropaque suspension 300 ml, application rate of 75 ml/min, dilution with HP-7000 being 1:1 and HP-7000 solution 2000 ml, application rate of 120 ml/min.). Results: The amyloid deposits in the small intestine could be visualized in five of seven patients with the disease. Enteroclysis revealed a diffuse slowed down intestinal motility with an obstruction-like picture in all of our seven patients. The intestinal secretion was normal, plicae were getting polyp-like shape in five of them forming so called 'thumb printing' picture. CT showed thickening of the intestinal wall due to deposits with poor blood supply and contrast retention in five of seven patients. Ultrasound visualized thickened, hypoechoic nodular plicae and slowed down motility in these five patients. The most striking finding was the pathological deposits in the intestinal wall were highly hypo-vascular. However, this picture is very similar to that of ischemic enteritis. All seven patients had proven amyloid deposits from bioptic specimens. Conclusion: The diagnosis of amyloidosis must be supported by bioptic examination as it has no pathognomic

  17. Mental retardation, premature balding, small genitalia, small acra and small patellae in brothers: Confirmation of an entity

    NARCIS (Netherlands)

    A.M. Vandersteen; R.C. Hennekam

    2010-01-01

    We describe two brothers with moderate to severe mental retardation, short stature, an unusual skull shape, early anterior balding, unusual facial morphology, hypogonadotrophic hypogonadism, small genitalia, and small patellae. The older sib had generalized hypotonia without focal neurological abnor

  18. Immunization against Small Ruminant Lentiviruses

    Directory of Open Access Journals (Sweden)

    Beatriz Amorena

    2013-08-01

    Full Text Available Multisystemic disease caused by Small Ruminant Lentiviruses (SRLV in sheep and goats leads to production losses, to the detriment of animal health and welfare. This, together with the lack of treatments, has triggered interest in exploring different strategies of immunization to control the widely spread SRLV infection and, also, to provide a useful model for HIV vaccines. These strategies involve inactivated whole virus, subunit vaccines, DNA encoding viral proteins in the presence or absence of plasmids encoding immunological adjuvants and naturally or artificially attenuated viruses. In this review, we revisit, comprehensively, the immunization strategies against SRLV and analyze this double edged tool individually, as it may contribute to either controlling or enhancing virus replication and/or disease.

  19. Small FDIRC Designs and Performances

    CERN Document Server

    Dey, B; Va'vra, J

    2016-01-01

    In this article we explore the angular resolution limits attainable in small FDIRC designs taking advantage of the new highly pixelated detectors that are now available. Since the basic FDIRC design concept attains its particle separation performance mostly in the angular domain as measured by two-dimensional pixels, this paper relies primarily on a pixel-based analysis, with additional chromatic corrections using the time domain, requiring single photon timing resolution at a level of 100-200ps only. This approach differs from other modern DIRC design concepts such as TOP or TORCH detectors, whose separation performances rely more strongly on time-dependent analyses. We find excellent single photon resolution with a geometry where individual bars are coupled to a single plate, coupled to cylindrical lens focusing.

  20. Small Business Innovations (Mass Microbalance)

    Science.gov (United States)

    1991-01-01

    Femtometrics of Costa Mesa, CA, developed the Model 200-1 SAW Mass Microbalance under a NASA Small Business Innovation Research (SBIR) contract with Langley Research Center. The product is described as "the next generation of aerosol mass microbalance technology," because a new type of sensor, the Surface Acoustic Wave (SAW) piezoelectric crystal, offers mass resolution two orders of magnitude greater than the Quartz Crystal Microbalance cascade impactor (QCM) (used at Langley since 1979 for collection and measurement of aerosol particles in the upper atmosphere). The Model 200-1 SAW Mass Microbalance, which provides a 400-fold increase in mass sensitivity per unit area over the QCM, can be used for real-time particle monitoring in clean rooms, measuring chemical vapors in very low concentrations, measuring target chemicals in the stratosphere and in industry as a toxic vapor monitor.

  1. Small Tank Tetraphenylborate Catalyst Studies

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, M.J.

    2001-06-04

    The Salt Disposition Systems Engineering Team identified Small Tank Tetraphenylborate Precipitation (STTP) as an alternative to replace the In-Tank Precipitation Facility at the Savannah River Site. The Department of Energy discontinued operation of the In-Tank Precipitation facility due to the potential for catalytic decomposition of sodium tetraphenylborate. The STTP applies the same process chemistry for removal of cesium from the radioactive wastes but at a controlled lower temperature and in a smaller facility that offers engineering features to mitigate potential for a catalytic reaction. However, additional understanding of the catalytic reaction, through further experimental investigation, is needed to better define the potential for a reaction to occur in the proposed facility.

  2. Aeration equipment for small depths

    Science.gov (United States)

    Sluše, Jan; Pochylý, František

    2015-05-01

    Deficit of air in water causes complications with cyanobacteria mainly in the summer months. Cyanobacteria is a bacteria that produces poison called cyanotoxin. When the concentration of cyanobacteria increases, the phenomena "algal bloom" appears, which is very toxic and may kill all the organisms. This article describes new equipment for aeration of water in dams, ponds and reservoirs with small depth. This equipment is mobile and it is able to work without any human factor because its control is provided by a GPS module. The main part of this equipment consists of a floating pump which pumps water from the surface. Another important part of this equipment is an aerator where water and air are blended. Final aeration process runs in the nozzles which provide movement of all this equipment and aeration of the water. Simulations of the flow are solved by multiphase flow with diffusion in open source program called OpenFOAM. Results will be verified by an experiment.

  3. Mycoplasmas: small but perfectly formed

    Directory of Open Access Journals (Sweden)

    Robin NICHOLAS

    2015-07-01

    Full Text Available Interest in mycoplasmas stems from their importance as serious animal and human pathogens, their frequent contamination of cell lines and, because of their small size, for their use as models of the minimal cell concept.They have traditionally been seen as highly host specific but this is being reviewed in view of recent detections of animal mycoplasmas in unlikely hosts including humans. Some highlights include:Mycoplasmas, containing as few as 450 genes, are the smallest free-living organisms on the planetThey were the first synthetically created life formsWhile the majority of mycoplasmas are harmless, the World Organisation for Animal Health (OIE have listed 4 mycoplasma diseases because of their serious socio-economic impacts10-15% of cell lines used for virus research are contaminated with mycoplasma Are they the real the causes of TSEs and other undiagnosed human conditions?

  4. Small Cell Network Topology Comparison

    Directory of Open Access Journals (Sweden)

    Jan Oppolzer

    2013-01-01

    Full Text Available One of the essential problems in a mobile network with small cells is that there is only a limited number of (PCIs available. Due to this fact, operators face the inevitable need for reusing (PCIs. In our contribution, we are dealing with a (PCI assignment to FAPs in three different topologies. The first model places FAPs randomly within the network while respecting overlapping defined. The second model places FAPs in a grid without other restrictions. The third model forms a grid as well, although buildings and roads are taken into account and (FAPs are always inside buildings. The proposed models are compared and a conclusion is made based on simulation results.

  5. Semitransparent peroral small bowel imaging

    Energy Technology Data Exchange (ETDEWEB)

    Emons, D.

    1981-10-01

    171 follow-through examinations of the small bowel performed in children and adolescents with a large contrast medium meal and the high voltage-low density barium technique (10 to 25 g BaSO/sub 4//100 ml, depending on age), are described. A ready made suspension, diluted with water, proved unsatisfactory. Coating properties and stability of the diluted, weak suspension were then greatly improved by hydroxyethylcellulose as a thickening agent and in addition by premedication of the patient with cimetidine. Pure cellulose solution instead of the last portion of barium prevented thickening in the ileum. The procedure has the well known advantages of a large contrast medium meal without the problem of overly dense superpositions.

  6. Disturbances in small bowel motility.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    Recently, the small intestine has become the focus of investigation as a potential site of dysmotility in the irritable bowel syndrome (IBS). A number of motor abnormalities have been defined in some studies, and include \\'clustered\\' contractions, exaggerated post-prandial motor response and disturbances in intestinal transit. The significance of these findings remains unclear. The interpretation of available studies is complicated by differences in subject selection, the direct influence of certain symptoms, such as diarrhoea and constipation, and the interference of compounding factors, such as stress and psychopathology. Dysmotility could also reflect autonomic dysfunction, disturbed CNS control and the response to heightened visceral sensation or central perception. While motor abnormalities may not explain all symptoms in IBS, sensorimotor interactions may be important in symptom pathogenesis and deserve further study.

  7. Episodic tremor triggers small earthquakes

    Science.gov (United States)

    Balcerak, Ernie

    2011-08-01

    It has been suggested that episodic tremor and slip (ETS), the weak shaking not associated with measurable earthquakes, could trigger nearby earthquakes. However, this had not been confirmed until recently. Vidale et al. monitored seismicity in the 4-month period around a 16-day episode of episodic tremor and slip in March 2010 in the Cascadia region. They observed five small earthquakes within the subducting slab during the ETS episode. They found that the timing and locations of earthquakes near the tremor suggest that the tremor and earthquakes are related. Furthermore, they observed that the rate of earthquakes across the area was several times higher within 2 days of tremor activity than at other times, adding to evidence of a connection between tremor and earthquakes. (Geochemistry, Geophysics, Geosystems, doi:10.1029/2011GC003559, 2011)

  8. Evaluation of small reactor economics

    International Nuclear Information System (INIS)

    The EPRI small reactor design program requires a procedure to analyze the economic benefits of specific design improvements suggested by the participating contractors, and to evaluate the total impacts of a new plant design on nuclear power generation costs. To that purpose, an analysis procedure is now being developed by EPRI and its participating contractors. This procedure involves the use of two separate costing models: 1. A top-down total generation cost model that integrates, in a relatively simplified manner, capital operating and fuel expenses, to yield total unit costs on an annual as well as on a lifetime levelized basis. A bottoms-up model that enables the analysis of specific system changes on station capital costs. Using a detailed reference plant cost breakdown, proposed design improvements can be measured against the reference data for their economic benefits

  9. Small boiler uses waste coal

    Energy Technology Data Exchange (ETDEWEB)

    Virr, M.J. [Spinheat Ltd. (United States)

    2009-07-15

    Burning coal waste in small boilers at low emissions poses considerable problem. While larger boiler suppliers have successfully installed designs in the 40 to 80 MW range for some years, the author has been developing small automated fluid bed boiler plants for 25 years that can be applied in the range of 10,000 to 140,000 lbs/hr of steam. Development has centered on the use of an internally circulating fluid bed (CFB) boiler, which will burn waste fuels of most types. The boiler is based on the traditional D-shaped watertable boiler, with a new type of combustion chamber that enables a three-to-one turndown to be achieved. The boilers have all the advantages of low emissions of the large fluid boilers while offering a much lower height incorporated into the package boiler concept. Recent tests with a waste coal that had a high nitrogen content of 1.45% demonstrated a NOx emission below the federal limit of 0.6 lbs/mm Btu. Thus a NOx reduction on the order of 85% can be demonstrate by combustion modification alone. Further reductions can be made by using a selective non-catalytic reduction (SNCR) system and sulfur absorption of up to 90% retention is possible. The article describes the operation of a 30,000 lbs/hr boiler at the Fayette Thermal LLC plant. Spinheat has installed three ICFB boilers at a nursing home and a prison, which has been tested on poor-grade anthracite and bituminous coal. 2 figs.

  10. Small government or big government?

    Directory of Open Access Journals (Sweden)

    MATEO SPAHO

    2015-03-01

    Full Text Available Since the beginning of the twentieth century, economists and philosophers were polarizedon their positions beyond the role that the government should have in the economy. On one hand John Maynard Keynes represented, within the optics of market economy, a position where the state should intervene in the economy to maintain the aggregate demand and the employment in the country, without hesitation in creating budget deficits and public debt expansion. This approach happens especially in the moments when the domestic economy and global economic trends show a weak growth or a recession. This means a heavy interference inthe economy, with higher income but with high expenditure to GDP too. On the other side, Liberals and Neoliberalsled by Friedrich Hayek advocated a withdrawal of the government from economic activity not just in moments of economic growth but also during the crisis, believing that the market has self-regulating mechanisms within itself. The government, as a result will have a smaller dimension with lower income and also low expenditures compared to the GDP of the country. We took the South-Eastern Europe countries distinguishing those with a "Big Government" or countries with "Small Government". There are analyzed the economic performances during the global crisis (2007-2014. In which countries the public debt grew less? Which country managed to attract more investments and which were the countries that preserved the purchasing power of their consumers? We shall see if during the economic crisis in Eastern Europe the Great Government or the Liberal and "Small" one has been the most successful the model.

  11. Effects of 60 Hz sinusoidal magnetic field on in vitro establishment, multiplication, and acclimatization phases of Coffea arabica seedlings.

    Science.gov (United States)

    Isaac Alemán, Elizabeth; Oliveira Moreira, Rafael; Almeida Lima, Andre; Chaves Silva, Samuel; González-Olmedo, Justo Lorenzo; Chalfun-Junior, Antonio

    2014-09-01

    The influence of extremely low frequency electromagnetic fields on net photosynthesis, transpiration, photosynthetic pigment concentration, and gene expression of ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit (RBCS1), during in vitro establishment, in vitro multiplication and acclimatization phases of coffee seedlings were investigated. Untreated coffee plants were considered as control, whereas treated plants were exposed to a 60 Hz sinusoidal magnetic field of 2 mT of magnetic induction during 3 min. This magnetic field was generated by an electromagnet, connected to a wave generator. The results revealed that magnetically treated plants showed a significant increase in net photosynthesis (85.4% and 117.9%, in multiplication and acclimatization phases, respectively), and in photosynthetic pigment concentration (66.6% for establishment phase, 79.9% for multiplication phase, and 43.8% for acclimatization phase). They also showed a differential RBCS1 gene expression (approximately twofold) and a decrease of transpiration rates in regard to their control plants. In conclusion, the findings suggest that the application of 60 Hz magnetic field to in vitro coffee plants may improve the seedlings quality by modifying some photosynthetic physiological and molecular processes, increasing their vigor, and ensuring better plant development in later stages.

  12. Sycamore amyloplasts can import and process precursors of nuclear encoded chloroplast proteins.

    Science.gov (United States)

    Strzalka, K; Ngernprasirtsiri, J; Watanabe, A; Akazawa, T

    1987-12-16

    Amyloplasts isolated from white-wild suspension-cultured cells of sycamore (Acer pseudoplatanus L.) are found to import and process the precursor of the small subunit (pS) of ribulose-1,5-bisphosphate carboxylase/oxygenase of spinach, but they lack the ability to form its holoenzyme due to the absence of both the large subunit and its binding-protein. They also import the precursor of the 33-kDa extrinsic protein (p33-kDa) of the O2-evolving complex of Photosystem II from spinach, but process is only to an intermediate form (i33-kDa). Chloroplasts from green-mutant cells of sycamore process p33-kDa to its mature form in this heterologous system. These results suggest that the thylakoid-associated protease responsible for the second processing step of p33-kDa is missing in amyloplasts, possibly due to the absence of thylakoid-membranes. In contrast, the apparent import of the precursor of the light-harvesting chlorophyll a/b-binding apoprotein (pLHCP) from spinach was not detected. Sycamore amyloplasts may lack the ability to import this particular thylakoid-protein, or rapidly degrade the imported molecules in the absence of thylakoid-membranes for their proper insertion.

  13. Effects of thermal stress of protein synthesis and gene expression in Brassica napus

    International Nuclear Information System (INIS)

    Leaf segments of Brassica napus were exposed to 22 degrees, 35 degrees, 38 degrees or 40 degrees C for up to 4 h. Analysis of radiolabelled proteins by 2-D SDS-PAGE and fluorography revealed two major groups of heat shock proteins (HSPs). One group comprised HSPs, 70, 76 and 87, with pIs ranging from 5.7 to 6.1, whereas the second group had molecular weights ranging from 23 to 16 kD and pIs from 5.6 to 6.9. Immunoblot analysis using antibodies directed against the large (RLSU) and small (RSSU) subunits of ribulose-1,5-bisphosphate carboxylase (RUBISCO) showed that increasing temperatures from 35 degrees to 38 degrees or 40 degrees C or the duration of thermal stress from 1 to 5 h did not affect levels of the RSSU (15 kd) whereas levels of the RLSU (52 kD) fell sharply. Nevertheless, RUBISCO activity was not adversely affected at 38 degree C for periods of up to 5 h. The increase observed in HSP 70 during heat shock was transcriptionally regulated, but the decrease in the RLSU was not accompanied by any detectable change in levels of its mRNA

  14. The bacterial carbon-fixing organelle is formed by shell envelopment of preassembled cargo.

    Directory of Open Access Journals (Sweden)

    Anna H Chen

    Full Text Available BACKGROUND: Cyanobacteria play a significant role in the global carbon cycle. In Synechococcuselongatus, the carbon-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO is concentrated into polyhedral, proteinaceous compartments called carboxysomes. METHODOLOGY/PRINCIPAL FINDINGS: Using live cell fluorescence microscopy, we show that carboxysomes are first detected as small seeds of RuBisCO that colocalize with existing carboxysomes. These seeds contain little or no shell protein, but increase in RuBisCO content over several hours, during which time they are exposed to the solvent. The maturing seed is then enclosed by shell proteins, a rapid process that seals RuBisCO from the cytosol to establish a distinct, solvent-protected microenvironment that is oxidizing relative to the cytosol. These closure events can be spatially and temporally coincident with the appearance of a nascent daughter RuBisCO seed. CONCLUSIONS/SIGNIFICANCE: Carboxysomes assemble in a stepwise fashion, inside-to-outside, revealing that cargo is the principle organizer of this compartment's biogenesis. Our observations of the spatial relationship of seeds to previously formed carboxysomes lead us to propose a model for carboxysome replication via sequential fission, polymerization, and encapsulation of their internal cargo.

  15. Cooperative insertion of CO2 in diamine-appended metal-organic frameworks

    Science.gov (United States)

    McDonald, Thomas M.; Mason, Jarad A.; Kong, Xueqian; Bloch, Eric D.; Gygi, David; Dani, Alessandro; Crocellà, Valentina; Giordanino, Filippo; Odoh, Samuel O.; Drisdell, Walter S.; Vlaisavljevich, Bess; Dzubak, Allison L.; Poloni, Roberta; Schnell, Sondre K.; Planas, Nora; Lee, Kyuho; Pascal, Tod; Wan, Liwen F.; Prendergast, David; Neaton, Jeffrey B.; Smit, Berend; Kortright, Jeffrey B.; Gagliardi, Laura; Bordiga, Silvia; Reimer, Jeffrey A.; Long, Jeffrey R.

    2015-03-01

    The process of carbon capture and sequestration has been proposed as a method of mitigating the build-up of greenhouse gases in the atmosphere. If implemented, the cost of electricity generated by a fossil fuel-burning power plant would rise substantially, owing to the expense of removing CO2 from the effluent stream. There is therefore an urgent need for more efficient gas separation technologies, such as those potentially offered by advanced solid adsorbents. Here we show that diamine-appended metal-organic frameworks can behave as `phase-change' adsorbents, with unusual step-shaped CO2 adsorption isotherms that shift markedly with temperature. Results from spectroscopic, diffraction and computational studies show that the origin of the sharp adsorption step is an unprecedented cooperative process in which, above a metal-dependent threshold pressure, CO2 molecules insert into metal-amine bonds, inducing a reorganization of the amines into well-ordered chains of ammonium carbamate. As a consequence, large CO2 separation capacities can be achieved with small temperature swings, and regeneration energies appreciably lower than achievable with state-of-the-art aqueous amine solutions become feasible. The results provide a mechanistic framework for designing highly efficient adsorbents for removing CO2 from various gas mixtures, and yield insights into the conservation of Mg2+ within the ribulose-1,5-bisphosphate carboxylase/oxygenase family of enzymes.

  16. Expression of chloroplast protein genes during the cell cycle of Chlamydomonas reinhardtii: evidence for transcriptional and translocational control

    International Nuclear Information System (INIS)

    Chlamydomonas reinhardtii cells, growing synchronously under a repeating 12 h light:12 h dark cycle, were used to investigate the synthesis and regulation of chloroplast proteins. The cells accumulate chlorophyll, the major thylakoid membrane proteins, and ribulose-1,5-bisphosphate carboxylase (RuBPCase) during the light (G1) period of the cell cycle. Pulse-labeling in vivo with [3H]arginine, and analysis of the protein synthetic capacity of thylakoid-bound polysomes in vitro, shows that these proteins are synthesized de novo during the light. Specific antibody and cloned DNA probes were obtained and used to estimate translatable and/or steady-state mRNA levels for light-harvesting (LHCII) and reaction center (D-1 and D-2) polypeptides of photosystem II, a light-harvesting polypeptide of photosystem I (LHCI), and the large (LS) and small (SS) subunits of RuBPCase. Levels of mRNA for the nuclear-encoded LHCI, LHCII and SS correlated with the synthesis of these polypeptides in vivo; they were higher in the light period and several-folded lower or absent during the dark period. The results suggest that synthesis of nuclear-encoded chloroplast proteins are regulated primarily by the level of mRNA. In contrast, regulation of chloroplast-encoded genes is achieved by controlling the translation of mRNA that is constitutively present, and by transcriptional mechanisms during light induction

  17. Normal Growth of Transgenic Tobacco Plants in the Absence of Cytosolic Pyruvate Kinase 1

    Science.gov (United States)

    Gottlob-McHugh, Sylvia G.; Sangwan, Rajender S.; Blakeley, Stephen D.; Vanlerberghe, Greg C.; Ko, Kenton; Turpin, David H.; Plaxton, William C.; Miki, Brian L.; Dennis, David T.

    1992-01-01

    The coding sequence of the cytosolic isozyme of potato tuber pyruvate kinase (PK) was attached to the transit peptide of the small subunit of pea ribulose-1,5-bisphosphate carboxylase oxygenase and placed under the control of the cauliflower mosaic virus 35S promoter. This construct was transformed into Nicotiana tabacum. Unexpectedly, two primary transformants were recovered in which PK activity in leaves was greatly reduced. The reduction in PK activity appeared to result from the complete absence of the cytosolic form of the enzyme (PKc). In addition, no PKc could be detected on western blots of leaf extracts. Metabolite analyses indicated that the levels of phosphoenolpyruvate are substantially higher in PKc-deficient leaves than in wild-type leaves, consistent with a block in glycolysis at the step catalyzed by PK. PKc deficiency in the leaves does not appear to adversely affect plant growth. Analysis of progeny indicates that PKc deficiency is a heritable trait. The leaves of PKc-deficient transformants have normal rates of photosynthetic O2 evolution and respiratory O2 consumption, indicating that these plants are using alternative pathways to bypass PK. Images Figure 2 Figure 4 PMID:16653063

  18. Effect of ozone on indicators of leaf aging. [Solanum tuberosum

    Energy Technology Data Exchange (ETDEWEB)

    Yisheng Ni; Yaoren Dai; Fayek Negm; Reddy, N. Flores, H.; Arteca, R.; Pell, E. (Pennsylvania State Univ., University Park (United States))

    1991-05-01

    Ozone (O{sub 3}) stress induces accelerated foliar senescence, as measured by a decline in ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). The authors wish to determine (1) whether the decline in rubisco is under genetic regulation and (2) what role is played by ethylene and polyamines in modulating this response. Plants of Solanum tuberosum L. cv. Norland were grown in a charcoal filtered greenhouse and treated with 0.15 {mu}1 1{sup {minus}1} O{sub 3} in continuous stirred tank reactors for 4 h. Immediately, 4 h and 20 h after O{sub 3} exposure, the fourth, seventh and tenth leaves from the apex were harvested and the tissue analyzed for ethylene emission, ethylene forming enzyme, malonyl transferase, ACC, malonyl ACC, spermine, spermidine, putrescine, ornithine decarboxylase and messenger RNA for the large and small subunits of rubisco. Ozone induced changes in most of the variables studied and the response was most evident in the younger tissue. In contrast O{sub 3} induces accelerated senescence of the oldest tissue. The relationship between O{sub 3}-induced changes in younger foliage and accelerated aging of older tissue will be the subject of further investigation.

  19. Characterization of SSU5C promoter of a rbcS gene from duckweed (Lemna gibba).

    Science.gov (United States)

    Wang, Youru; Zhang, Yong; Yang, Baoyu; Chen, Shiyun

    2011-04-01

    Photosynthesis-associated nuclear genes are able to respond to multiple environmental and developmental signals. Studies have shown that light signals coordinate with hormone signaling pathways to control photomorphogenesis. A small subunit of ribulose-1,5 bisphosphate carboxylase/oxygenase (rbcS) gene promoter was cloned from duckweed (Lemna gibba). Sequence analysis revealed this promoter is different from the previously reported rbcs promoters and is named SSU5C. Analysis of T1 transgenic tobacco plants with a reporter gene under the control of the SSU5C promoter revealed that this promoter is tissue-specific and is positively regulated by red light. Promoter deletion analysis confirmed a region from position -152 to -49 relative to the start of transcription containing boxes X, Y and Z, and is identified to be critical for phytochrome responses. Further functional analysis of constructs of box-X, Y, Z, which was respectively fused to the basal SSU5C promoter, defined boxes X, Y and Z alone are able to direct phytochrome-regulated expression, indicating that boxes Y and Z are different from those of the SSU5B promoters in L. gibba. This promoter may be used for plant gene expression in a tissue-specific manner. PMID:21080078

  20. Functional analysis of a Lemna gibba rbcS promoter regulated by abscisic acid and sugar.

    Science.gov (United States)

    Wang, Youru

    2013-04-01

    Photosynthesis-associated nuclear genes (PhANGs) are able to respond to multiple environmental and developmental signals, including light, sugar and abscisic acid (ABA). PhANGs have been extensively studied at the level of transcriptional regulation, and several cis-acting elements important for light responsiveness have been identified in their promoter sequences. However, the regulatory elements involved in sugar and ABA regulation of PhANGs have not been completely characterized. A ribulose-1,5-bisphosphate carboxylase small subunit gene (rbcS) promoter (SSU5C promoter) was isolated from duckweed (Lemna gibba). A series of SSU5C promoter 5' deletion fragments were fused to an intron-gus gene, and transgenic tobacco suspension cell lines were generated. Assay of tobacco suspension cell line harbouring the complete promoter in the fusion construct indicated that SSU5C promoter was negatively regulated by sugar and ABA under the condition of regular photoperiod. 5' deletion analysis of SSU5C promoter in transgenic tobacco suspension cell lines confirmed that a region between positions -310 and -152 included the ABA-response region, and that sugar-response cis-acting elements might be located in the region between -152 and -117. Taken together, our results confirmed that the cis-regulatory region responsible for repression by ABA and sugar in the SSU5C promoter was located between -310 and -117. PMID:23640406

  1. Changes in Protein Synthesis in Rapeseed (Brassica napus) Seedlings during a Low Temperature Treatment 1

    Science.gov (United States)

    Meza-Basso, Luis; Alberdi, Miren; Raynal, Monique; Ferrero-Cadinanos, Maria-Luz; Delseny, Michel

    1986-01-01

    Changes induced by cold treatment in young rapeseed (Brassica napus) seedlings were investigated at the molecular level. Following germination at 18°C for 48 hours, one half of the seedlings was transferred to 0°C for another 48 hour period, the other half being kept at 18°C as a control. Newly synthesized proteins were labeled for the last 6 hours of incubation with [35S]methionine. The different polypeptides were separated by two-dimensional electrophoresis in polyacrylamide gels. Newly synthesized proteins were revealed by fluorography. Protein synthesis clearly continues at 0°C and some polypeptides preferentially accumulate at this temperature. On the other hand, synthesis of several others is repressed while many are insensitive to cold treatment. Similar changes are also observed when mRNA is prepared from cold treated seedlings, translated in vitro in a reticulocyte cell free system and compared with the products of mRNA extracted from control samples. Among the genes which are repressed we identified the small subunit of ribulose 1,6-bisphosphate carboxylase. These changes are also detectable after shorter treatments. Images Fig. 1 Fig. 2 Fig. 3 PMID:16665102

  2. Pea amyloplast DNA is qualitatively similar to pea chloroplast DNA

    Science.gov (United States)

    Gaynor, J. J.

    1984-01-01

    Amyloplast DNA (apDNA), when subjected to digestion with restriction endonucleases, yields patterns nearly identical to that of DNA from mature pea chloroplasts (ctDNA). Southern transfers of apDNA and ctDNA, probed with the large subunit (LS) gene of ribulose-1,5-bisphosphate carboxylase (Rubisco), shows hybridization to the expected restriction fragments for both apDNA and ctDNA. However, Northern transfers of total RNA from chloroplasts and amyloplasts, probed again with the LS gene of Rubisco, shows that no detectable LS meggage is found in amyloplasts although LS expression in mature chloroplasts is high. Likewise, two dimensional polyacrylamide gel electrophoresis of etiolated gravisensitive pea tissue shows that both large and small subunits of Rubisco are conspicuously absent; however, in greening tissue these two constitute the major soluble proteins. These findings suggest that although the informational content of these two organelle types is equivalent, gene expression is quite different and is presumably under nuclear control.

  3. Functional analysis of a Lemna gibba rbcS promoter regulated by abscisic acid and sugar

    Indian Academy of Sciences (India)

    Youru Wang

    2013-04-01

    Photosynthesis-associated nuclear genes (PhANGs) are able to respond to multiple environmental and developmental signals, including light, sugar and abscisic acid (ABA). PhANGs have been extensively studied at the level of transcriptional regulation, and several cis-acting elements important for light responsiveness have been identified in their promoter sequences. However, the regulatory elements involved in sugar and ABA regulation of PhANGs have not been completely characterized. A ribulose-1,5-bisphosphate carboxylase small subunit gene (rbcS) promoter (SSU5C promoter) was isolated from duckweed (Lemna gibba). A series of SSU5C promoter 5′ deletion fragments were fused to an intron–gus gene, and transgenic tobacco suspension cell lines were generated. Assay of tobacco suspension cell line harbouring the complete promoter in the fusion construct indicated that SSU5C promoter was negatively regulated by sugar and ABA under the condition of regular photoperiod. 5′ deletion analysis of SSU5C promoter in transgenic tobacco suspension cell lines confirmed that a region between positions $-310$ and $-152$ included the ABA-response region, and that sugar-response cis-acting elements might be located in the region between $-152$ and $-117$. Taken together, our results confirmed that the cis-regulatory region responsible for repression by ABA and sugar in the SSU5C promoter was located between $-310$ and $-117$.

  4. Use of Silica Sol Step Gradients to Prepare Bundle Sheath and Mesophyll Chloroplasts from Panicum maximum.

    Science.gov (United States)

    Walbot, V

    1977-07-01

    The first method for the direct separation of mesophyll and bundle sheath chloroplasts from whole tissue homogenates of a C(4) plant is described. Centrifugation of mixed chloroplast preparations from Panicum maximum through low viscosity silica sol gradients effectively separates large, starch-containing chloroplasts from smaller plastids. The large chloroplasts are judged to be bundle sheath chloroplasts on the basis of microscopic appearance, the presence of starch grains, the protein complement displayed on sodium dodecyl sulfate acrylamide gels, and the exclusive localization of ribulose bisphosphate carboxylase activity in these plastids. As a measure of intactness both the large (bundle sheath) and small (mesophyll) chloroplasts contain glyceralde-hyde-3-phosphate NADP-dependent dehydrogenase activity that is greatly enhanced by plastid lysis and both chloroplast preparations are impermeable to deoxyribonuclease. Chloroplast enzyme activities are inhibited by silica sol due to the Mg(2+) chelating activity of this reagent. However, well washed chloroplasts separated on silica gradients had enzyme activities similar to reported values in which silica sol gradients were not used. PMID:16660019

  5. Chemisorption and Reactions of Small Molecules on Small Gold Particles

    Directory of Open Access Journals (Sweden)

    Geoffrey C. Bond

    2012-02-01

    Full Text Available The activity of supported gold particles for a number of oxidations and hydrogenations starts to increase dramatically as the size falls below ~3 nm. This is accompanied by an increased propensity to chemisorption, especially of oxygen and hydrogen. The explanation for these phenomena has to be sought in kinetic analysis that connects catalytic activity with the strength and extent of chemisorption of the reactants, the latter depending on the electronic structure of the gold atoms constituting the active centre. Examination of the changes to the utilisation of electrons as particle size is decreased points to loss of metallic character at about 3 nm, as energy bands are replaced by levels, and a band gap appears. Detailed consideration of the Arrhenius parameters (E and ln A for CO oxidation points clearly to a step-change in activity at the point where metallic character is lost, as opposed to there being a monotonic dependence of rate on a physical property such as the fraction of atoms at corners or edges of particles. The deplorable scarcity of kinetic information on other reactions makes extension of this analysis difficult, but non-metallic behaviour is an unavoidable property of very small gold particles, and therefore cannot be ignored when seeking to explain their exceptional activity.

  6. Beam Coupling Impedances of Small Discontinuities

    CERN Document Server

    Kurennoy, S S

    2000-01-01

    A general derivation of the beam coupling impedances produced by small discontinuities on the wall of the vacuum chamber of an accelerator is reviewed. A collection of analytical formulas for the impedances of small obstacles is presented.

  7. New Funding Opportunities for Small Businesses Announced

    Science.gov (United States)

    The National Cancer Institute Small Business Innovation Research (SBIR) program recently announced $8 million in new contract funding opportunities to assist small businesses with cancer research and technology development. The 12 new contract funding opp

  8. Cancer Statistics: Cancer of the Small Intestine

    Science.gov (United States)

    ... party. HPF: SEER Stat Fact Sheets: Small Intestine Cancer Expand All Collapse All Lifetime risk estimates are ... Or More after Being Diagnosed with Small Intestine Cancer? Relative survival statistics compare the survival of patients ...

  9. Enabling Technology for Small Satellite Launch Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Access to space for Small Satellites is enabled by the use of excess launch capacity on existing launch vehicles. A range of sizes, form factors and masses of small...

  10. Lung cancer - non-small cell

    Science.gov (United States)

    Cancer - lung - non-small cell; Non-small cell lung cancer; NSCLC; Adenocarcinoma - lung; Squamous cell carcinoma - lung ... Smoking causes most cases (around 90%) of lung cancer. The risk depends on the number of cigarettes ...

  11. Is small business a safety problem?

    OpenAIRE

    Larsson, Tore J

    2003-01-01

    Common beliefs in relation to safety in small business are of two types; a) small businesses are more unsafe, apply unsafe practices, and thus have a higher incidence of occupational injury and a higher average severity of injury, and b) small business have poor knowledge of, and exhibit low compliance with, laws, rules and regulations, and are increasingly difficult to control. A survey of 100 small business operators in the suburbs of Melbourne, Australia was undertaken. Ten different indus...

  12. Marketing Channels Used by Small Tennessee Farmers

    OpenAIRE

    Tegegne, Fisseha; Pasirayi, Simbarashe; Singh, Surendra P.; Ekanem, Enefiok P.

    2012-01-01

    One of the key challenges that small farmers face is marketing their products. National and international markets are difficult to tap into for small farmers due to their inability to compete with large farm operators that dominate these markets. The objective of this study was to examine marketing channels used by small Tennessee Farmers. A mail survey was sent to 250 selected small farmers in Tennessee. Ninety-two completed responses, representing about 37% response rate, were received. Ove...

  13. Myoglobin in pelagic small cetaceans.

    Science.gov (United States)

    Dolar, M L; Suarez, P; Ponganis, P J; Kooyman, G L

    1999-02-01

    Although myoglobin (Mb) is considered to contribute significantly to the oxygen and diving capacity of marine mammals, few data are available for cetaceans. Cetacean by-catch in the tuna driftnet fisheries in the Sulu Sea, Philippines, afforded the opportunity to examine Mb content and distribution, and to determine muscle mass composition, in Fraser's (Lagenodelphis hosei) and spinner (Stenella longirostris) dolphins and a pygmy killer whale (Feresa attenuata). Age was estimated by body length determination. Stomach contents were analyzed for the presence or absence of milk and solid foods. It was hypothesized (a) that Mb concentration ([Mb]) would be higher in Fraser's and spinner dolphins than in other small cetaceans because of the known mesopelagic distribution of their prey, (b) that [Mb] would vary among different muscles according to function during diving, and (c) that [Mb] would increase with age during development. The results were as follows. (1) Myoglobin concentrations of the longissimus muscle in adult Fraser's (6.8-7.2 g 100 g-1 muscle) and spinner (5-6 g 100 g-1 muscle) dolphins and in an immature pygmy killer whale (5.7 g 100 g-1 muscle) were higher than those reported previously for small cetaceans. (2) [Mb] varied significantly among the different muscle types in adult dolphins but not in calves; in adults, swimming muscles had significantly higher [Mb] than did non-swimming muscles, contained 82-86 % of total Mb, and constituted 75-80 % of total muscle mass. (3) Myoglobin concentrations in Fraser's and spinner dolphins increased with size and age and were 3-4 times greater in adults than in calves. The high Mb concentrations measured in the primary locomotory muscles of these pelagic dolphins are consistent with the known mesopelagic foraging behaviour of Fraser's and spinner dolphins and suggest that the pygmy killer whale is also a deep-diving species. The high Mb concentrations in epaxial, hypaxial and abdominal muscle groups also support

  14. 77 FR 46909 - Small Business Innovation Research (SBIR) Program and Small Business Technology Transfer (STTR...

    Science.gov (United States)

    2012-08-06

    ... Innovation Research (SBIR) Program and Small Business Technology Transfer (STTR) Program Policy Directives... Small Business Innovation Research (SBIR) and Small Business Technology Transfer Program (STTR) Policy... technology@sba.gov . SUPPLEMENTARY INFORMATION: I. Background Information SBA is publishing Policy...

  15. 27 CFR 19.912 - Small plants.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Small plants. 19.912... OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits For Fuel Use Permits § 19.912 Small plants. Persons wishing to establish a small plant shall apply for a permit as provided in...

  16. Understanding the statistics of small risks

    International Nuclear Information System (INIS)

    Monte Carlo analyses are used to show what inferences can and cannot be drawn when either a very small number of accidents result from a considerable exposure or where a very small number of people, down to a single individual, are exposed to small added risks. The distinction between relative and absolute uncertainty is illustrated. No new statistical principles are involved

  17. 7 CFR 201.42 - Small containers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Small containers. 201.42 Section 201.42 Agriculture... REGULATIONS Sampling in the Administration of the Act § 201.42 Small containers. In sampling seed in small containers that it is not practical to sample as required in § 201.41, a portion of one unopened container...

  18. Mutual Guarantee Institutions and Small Business Finance

    NARCIS (Netherlands)

    Columba, F.; Gambacorta, L.; Mistrulli, P.E.

    2009-01-01

    A large literature showed that small firms experience difficulties in accessing the credit market due to informational asymmetries; these may be mitigated by collateral or relationship lending, possibilities often precluded to small business. We investigate the effect on small business finance of an

  19. Yes, small firms can commercialize photonics

    Science.gov (United States)

    Nelson, Carl W.

    1997-01-01

    Small young companies can commercialize photonics. Many are already doing so and may more are getting started with a small government subsidy from Small Business Innovation Research. Capital is gushing, even begging for good investment opportunities, for companies ready to commit themselves to commercial success.

  20. Finding the "Right Staff" in Small Firms

    Science.gov (United States)

    Barrett, Rowena; Neeson, Robyn; Billington, Leo

    2007-01-01

    Purpose: The purpose of this paper is to explore what owners of small firms are looking for from new employees. The aim is to pursue this in light of the debate around formality and informality of small firm HRM, exploring the extent to which the small firms studied had formalized HRM practices. Design/methodology/approach: The data reported here…

  1. Assessing prospects for small reactors

    International Nuclear Information System (INIS)

    The use of nuclear power plants, like that of many other technologies, has been characterized by substantial growth in spread, numbers, equipment and plant sizes, with economies of scale generally favouring the large plants. Small and medium sized nuclear power plants, or SMPRs, are generally understood to be plants below the sizes being exploited commercially in industrialized countries. Such plants could be more readily adapted to smaller electric grids, particularly in developing countries, fulfilling requirements of low load growth, or serve remote locations or special purposes. The SMPR range is currently understood as the 200 to 500 megawatt (MWe) size for the generation of electricity and sometimes smaller for process-steam and/or low-temperature heat supply. For statistical purposes a size limit of 600 MWe has been in use by IAEA for some years. By this criterion some 140 nuclear power plants, or more than one-third of the world total, could be considered SMPRs. However, most of them are rather old vintage. Prospects are assessed under headings: indications of revived interest; today's SMPR supply situation; evolving IAEA programme - new study; market indications; economic competitiveness and financing aspects. (author)

  2. Neurological examination in small animals

    Directory of Open Access Journals (Sweden)

    Viktor Paluš

    2014-03-01

    Full Text Available This clinical review about the neurological examination in small animals describes the basics about the first steps of investigation when dealing with neurological patients. The knowledge of how to perform the neurological examination is important however more important is how to correctly interpret these performed tests. A step-by-step approach is mandatory and examiners should master the order and the style of performing these tests. Neurological conditions can be sometimes very distressing for owners and for pets that might not be the most cooperating. The role of a veterinary surgeon, as a professional, is therefore to collect the most relevant history, to examine a patient in a professional manner and to give to owners an educated opinion about the further treatment and prognosis. However neurological examinations might look challenging for many. But it is only the clinical application of neuroanatomy and neurophysiology to an every-day situation for practicing veterinarians and it does not require any specific in-to-depth knowledge. This clinical review is aimed not only to provide the information on how to perform the neurological examination but it is also aimed to appeal on veterinarians to challenge their daily routine and to start practicing on neurologically normal patients. This is the best and only way to differentiate between the normal and abnormal in a real situation.

  3. The small world of psychopathology.

    Directory of Open Access Journals (Sweden)

    Denny Borsboom

    Full Text Available BACKGROUND: Mental disorders are highly comorbid: people having one disorder are likely to have another as well. We explain empirical comorbidity patterns based on a network model of psychiatric symptoms, derived from an analysis of symptom overlap in the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV. PRINCIPAL FINDINGS: We show that a half of the symptoms in the DSM-IV network are connected, b the architecture of these connections conforms to a small world structure, featuring a high degree of clustering but a short average path length, and c distances between disorders in this structure predict empirical comorbidity rates. Network simulations of Major Depressive Episode and Generalized Anxiety Disorder show that the model faithfully reproduces empirical population statistics for these disorders. CONCLUSIONS: In the network model, mental disorders are inherently complex. This explains the limited successes of genetic, neuroscientific, and etiological approaches to unravel their causes. We outline a psychosystems approach to investigate the structure and dynamics of mental disorders.

  4. Aeration equipment for small depths

    Directory of Open Access Journals (Sweden)

    Sluše Jan

    2015-01-01

    Full Text Available Deficit of air in water causes complications with cyanobacteria mainly in the summer months. Cyanobacteria is a bacteria that produces poison called cyanotoxin. When the concentration of cyanobacteria increases, the phenomena „algal bloom“ appears, which is very toxic and may kill all the organisms. This article describes new equipment for aeration of water in dams, ponds and reservoirs with small depth. This equipment is mobile and it is able to work without any human factor because its control is provided by a GPS module. The main part of this equipment consists of a floating pump which pumps water from the surface. Another important part of this equipment is an aerator where water and air are blended. Final aeration process runs in the nozzles which provide movement of all this equipment and aeration of the water. Simulations of the flow are solved by multiphase flow with diffusion in open source program called OpenFOAM. Results will be verified by an experiment.

  5. Small Technology Business Incubation Needs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2007-12-31

    This report contains a summary of typical business incubation needs of small technology companies. This document will serve as a guide in the design and implementation of services offered by the National Security Technology Incubator (NSTI), an incubator program being designed and developed as part of the National Security Preparedness Project (NSPP), performed under a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This report includes a brief description of the methodology used to perform the needs assessment and services proposed to meet the needs of client companies. The purpose of the NSPP is to promote national security technologies through business incubation, technology demonstration and validation, and workforce development. The NSTI will focus on serving businesses with national security technology applications by nurturing them through critical stages of early development. The vision of the NSTI is to be a successful incubator of technologies and private enterprise that assist the NNSA in meeting new challenges in national safety, security, and protection of the homeland.

  6. Public acceptance of small reactors

    International Nuclear Information System (INIS)

    The success of any nuclear program requires acceptance by the local public and all levels of government involved in the decision to initiate a reactor program. Public acceptance of a nuclear energy source is a major challenge in successful initiation of a small reactor program. In AECL's experience, public acceptance will not be obtained until the public is convinced that the specific nuclear program is needed, safe and economic and environmental benefit to the community. The title of public acceptance is misleading. The objective of the program is a fully informed public. The program proponent cannot force public acceptance, which is beyond his control. He can, however, ensure that the public is informed. Once information has begun to flow to the public by various means as will be explained later, the proponent is responsible to ensure that the information that is provided by him and by others is accurate. Most importantly, and perhaps most difficult to accomplish, the proponent must develop a consultative process that allows the proponent and the public to agree on actions that are acceptable to the proponent and the community

  7. Small drops from large nozzles

    Science.gov (United States)

    Castrejon-Pita, Alfonso Arturo; Said Mohamed, Ahmed; Castrejon-Pita, Jose Rafael; Herrada, Miguel Angel

    2015-11-01

    We report experimental and numerical results of the generation of drops which are significantly smaller than the nozzle from which they are generated. The system consists of a cylindrical reservoir and two endplates. One plate is a thin metal sheet with a small orifice in its centre which acts as the nozzle. The other end consists of a piston which moves by the action of an elecromechanical actuator which in turn is driven by sine-shape pull-mode pulses. The meniscus (formed at the nozzle) is thus first overturned, forming a cavity. This cavity collapses and a thin and fast jet emerges from its centre. Under appropriate conditions the tip of this jet breaks up and produces a single diminutive drop. A good agreement between the experimental and numerical results was found. Also, a series of experiments were performed in order to study the effects that the pulse amplitude and width, together with variations in the liquid properties, have over the final size of the droplet. Based on these experiments, a predictive law for the droplet size has been derived. This work was funded by the Royal Society (University Research Fellowship and Research Grant), the John Fell Fund (Oxford University Press), the Ministry of Science and Education (DPI2013-46485 Spain), and the Junta de Andalucia (P08-TEP-31704128 Spain).

  8. Small is beautiful, and dry

    Institute of Scientific and Technical Information of China (English)

    SHERIDAN; John

    2010-01-01

    Thousands of plant and animal species have been observed to have superhydrophobic surfaces that lead to various novel behaviors. These observations have inspired attempts to create artificial superhydrophobic surfaces, given that such surfaces have multitudinous applications. Superhydrophobicity is an enhanced effect of surface roughness and there are known relationships that correlate surface roughness and superhydrophobicity, based on the underlying physics. However, while these examples demonstrate the level of roughness they tell us little about the independence of this effect in terms of its scale. Thus, they are not capable of explaining why such naturally occurring surfaces commonly have micron-submicron sizes. Here we report on the discovery of a new relation, its physical basis and its experimental verification. The results reveal that scaling-down roughness into the micro-submicron range is a unique and elegant strategy to not only achieve superhydrophobicity but also to increase its stability against environmental disturbances. This new relation takes into account the previously overlooked but key fact that the accumulated line energy arising from the numerous solid-water-air intersections that can be distributed over the apparent contact area, when air packets are trapped at small scales on the surface, can dramatically increase as the roughness scale shrinks. This term can in fact become the dominant contributor to the surface energy and so becomes crucial for accomplishing superhydrophobicity. These findings guide fabrication of stable super water-repellant surfaces.

  9. XP in a Small Software Development Business

    DEFF Research Database (Denmark)

    Babb, Jeffry; Hoda, Rashina; Nørbjerg, Jacob

    2014-01-01

    While small software development shops have trended towards the adoption of Agile methods, local conditions and high iteration pressure typically cause adaptations and appropriations of Agile methods. This paper shares evidence from a study concerning how a small software development company adop...... most sustainable for small shop teams, with process maintenance and viability as a goal, are highlighted.......While small software development shops have trended towards the adoption of Agile methods, local conditions and high iteration pressure typically cause adaptations and appropriations of Agile methods. This paper shares evidence from a study concerning how a small software development company adopts...

  10. Fast Development Of China's Small Satellite Industry

    Institute of Scientific and Technical Information of China (English)

    Sun Hongjin

    2009-01-01

    @@ China Spacesat Co., Ltd of China Academy of Space Technology (CAST) recently said, along with the successful launch of HJ-1A/B for the environment and disaster monitoring and forecasting small satellite constellation and after years of efforts, small satellite development technology has achieved fruitful results, and the development status has been greatly improved.China's small satellite technology has realized a great-leap-forward in development from a single satellite model to series model, from the satellite program to space industry. China has explored a development road for China's small satellite industrialization, and a modern small satellite development base has resulted.

  11. New developments in small reactors

    International Nuclear Information System (INIS)

    During the fifty years since nuclear fission was discovered, nuclear energy has emerged to play an increasingly important role in meeting global energy needs. At the recent World Energy Conference in Montreal, 1989 September, experts agreed that nuclear power will continue to be an essential part of the future energy mix. The demand for economic and reliable energy sources is driven by the growth in the world's population and the essential role energy plays in industrial development. Global energy requirements, expected to double over the next 40 years, will seriously challenge suppliers in their ability to meet the demand. Ultimately, efficient energy utilization will become singularly important. Industrialization and economic development manifest themselves in urbanization. Urban dwellers consume significantly more energy per capita compared with their rural neighbours. Consequently, concentrated and environmentally acceptable energy sources, combined with efficient distribution systems, are now recognized as essential to meet urban energy demands. In considering the alternatives that will meet these requirements, nuclear energy qualifies as both a concentrated and environmentally benign source. Nuclear electricity generation is a mature technology that paves the way for other applications. If nuclear energy is to realize its full potential as a safe and cost-effective alternative to fossil fuels, applications beyond those that are currently being serviced by large, central nuclear power stations must be identified, and appropriately designed and sized reactors developed as an investment in the future. To meet this potential, new small reactor concepts are being developed to satisfy the expected energy demands, while also displaying characteristics that address current public concerns for providing minimal environmental impact. Concepts ranging in sized from 10 MW(t) to 1000 MW(t) are being pursued in a number of countries, including Canada, USA, UK, China, and

  12. Large and small photovoltaic powerplants

    Science.gov (United States)

    Cormode, Daniel

    The installed base of photovoltaic power plants in the United States has roughly doubled every 1 to 2 years between 2008 and 2015. The primary economic drivers of this are government mandates for renewable power, falling prices for all PV system components, 3rd party ownership models, and a generous tariff scheme known as net-metering. Other drivers include a desire for decreasing the environmental impact of electricity generation and a desire for some degree of independence from the local electric utility. The result is that in coming years, PV power will move from being a minor niche to a mainstream source of energy. As additional PV power comes online this will create challenges for the electric grid operators. We examine some problems related to large scale adoption of PV power in the United States. We do this by first discussing questions of reliability and efficiency at the PV system level. We measure the output of a fleet of small PV systems installed at Tucson Electric Power, and we characterize the degradation of those PV systems over several years. We develop methods to predict energy output from PV systems and quantify the impact of negatives such as partial shading, inverter inefficiency and malfunction of bypass diodes. Later we characterize the variability from large PV systems, including fleets of geographically diverse utility scale power plants. We also consider the power and energy requirements needed to smooth those systems, both from the perspective of an individual system and as a fleet. Finally we report on experiments from a utility scale PV plus battery hybrid system deployed near Tucson, Arizona where we characterize the ability of this system to produce smoothly ramping power as well as production of ancillary energy services such as frequency response.

  13. EFFECT OF MARKET ORIENTATION ON SMALL BUSINESS PERORMANCE IN SMALL TOWN IN MALAYSIA: AN EMPRICAL STUDY ON MALAYSIAN SMALL FIRMS

    Directory of Open Access Journals (Sweden)

    Muhammad Masroor ALAM

    2010-01-01

    Full Text Available Most research on market orientation, and performance was related to big firms. In this study, based on the theoretical framework, a model was developed to investigate the effect of market orientation on business performance in small firms. To test the relationships among the variables, data from 53 small firms in the small town of Chunglun at Sintok, Kedah was used. The findings show that the three components of market orientation are related positive to business performance of small firms. The further analysis also confirmed that customer orientation and competitor orientation are strong predictors of small firm performance. The findings of this study confirm that market orientation behavior also applies to small firms.

  14. Small Modular Reactors: Institutional Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Perkowski, Ph.D.

    2012-06-01

    ? Objectives include, among others, a description of the basic development status of “small modular reactors” (SMRs) focused primarily on domestic activity; investigation of the domestic market appeal of modular reactors from the viewpoints of both key energy sector customers and also key stakeholders in the financial community; and consideration of how to proceed further with a pro-active "core group" of stakeholders substantially interested in modular nuclear deployment in order to provide the basis to expedite design/construction activity and regulatory approval. ? Information gathering was via available resources, both published and personal communications with key individual stakeholders; published information is limited to that already in public domain (no confidentiality); viewpoints from interviews are incorporated within. Discussions at both government-hosted and private-hosted SMR meetings are reflected herein. INL itself maintains a neutral view on all issues described. Note: as per prior discussion between INL and CAP, individual and highly knowledgeable senior-level stakeholders provided the bulk of insights herein, and the results of those interviews are the main source of the observations of this report. ? Attachment A is the list of individual stakeholders consulted to date, including some who provided significant earlier assessments of SMR institutional feasibility. ? Attachments B, C, and D are included to provide substantial context on the international status of SMR development; they are not intended to be comprehensive and are individualized due to the separate nature of the source materials. Attachment E is a summary of the DOE requirements for winning teams regarding the current SMR solicitation. Attachment F deserves separate consideration due to the relative maturity of the SMART SMR program underway in Korea. Attachment G provides illustrative SMR design features and is intended for background. Attachment H is included for overview

  15. 78 FR 59410 - Small Business Innovation Research and Small Business Technology Transfer Programs...

    Science.gov (United States)

    2013-09-26

    ... ADMINISTRATION Small Business Innovation Research and Small Business Technology Transfer Programs... period for the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR... Street SW., Washington, DC 20416; or send an email to Technology@sba.gov . Highlight the information...

  16. 12 CFR 32.7 - Residential real estate loans, small business loans, and small farm loans.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Residential real estate loans, small business loans, and small farm loans. 32.7 Section 32.7 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY LENDING LIMITS § 32.7 Residential real estate loans, small business loans, and small farm loans. (a) Residential real...

  17. 77 FR 28237 - Small Business Size Regulations; 8(a) Business Development/Small Disadvantaged Business Status...

    Science.gov (United States)

    2012-05-14

    ... / Monday, May 14, 2012 / Rules and Regulations#0;#0; ] SMALL BUSINESS ADMINISTRATION 13 CFR Part 124 RIN 3245-AF53 Small Business Size Regulations; 8(a) Business Development/Small Disadvantaged Business Status Determinations; Correction AGENCY: U.S. Small Business Administration. ACTION:...

  18. SMALL ENTERPRENEURSHIP IN HOSPITALITY: CROATIAN EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Slobodan Ivanovic

    2013-03-01

    Full Text Available After introductory explanations regarding the selection problems of small enterprises in the Croatian hotel industry, the author provides a number of key indicators of their role in improving the competitiveness of the Croatian hotel industry in the global tourism market. In developed tourism countries, small enterprises have a dominant share in the structure of the hotel industry, and their importance is growing even in the former socialist countries of Europe. Small hotels in Italy accounted for more than 50%, and in Austria with more than 70% of lodging facilities and represent a generator of hotel business in a large number of European tourism countries, and great attention is given to the small enterpreneurs stimulating their growth with different measures of tourist and general economy politics. The author reflects on the Croatian experience of the small businesses in the hospitality through research of development of small family hotels and their importance for the improvement of the supply of the Croatian hotel industry which future is built on personal approach to guests and present trends in the tourism market. States that the role of the National Association of family and small hotels, which represents the specific interests of small hoteliers and enables the continuous improvement of the quality of their offerings, as well as measures to encourage small business development at the macro level. Based on the made analysis the measures of increasing the efficiency of small businesses in the Croatian hospitality are given.

  19. Why Small Manufacturing Firms Shun DCF

    OpenAIRE

    Walker, Joe; Burns, Richard; Denson, Chad

    1993-01-01

    Although there is ample literature on the use of capital budgeting techniques by small firms, there is practically no research available on why small firms don’t use discounted cash flow methods. This paper looks at this rationale issue in die light of Brigham's 10 hypodieses (in Fundamentals of Financial Management, sixth edition). Support is found primarily for Brigham’s ignorance hypothesis, but also for his other hypotheses concerning small firms’ short-run cash flow orientation, the comp...

  20. Small Package Transportation Companies: An Exploratory Analysis

    OpenAIRE

    Scott Lee WILLIAMS; Nabil RAZZOUK; Victoria SEITZ

    2008-01-01

    Purpose: To determine the evaluative criteria used when choosing small-package transportation companies, the level of importance of selected criteria, and how selected package carriers are perceived by small business decision makers. Methodology: Data were collected via self-administered questionnaires from a total of 31 decision makers in small businesses. The self-administered questionnaire was designed with four sections that handled separate but related topics. Questions from all four sec...

  1. Small animal dentistry in Canada: 1994 survey.

    OpenAIRE

    Haws, I J; Anthony, J .M.

    1996-01-01

    Small animal dentistry is a rapidly growing area of interest and specialization internationally, offering tremendous benefits to patients, clients, and practitioners. To date, no studies have been done to determine the standard of small animal dental care in Canada. A national mail survey was designed to document the prevalence of dental disease in small animal patients, the types of veterinary dental procedures being provided by practitioners, as well as home care recommendations and complia...

  2. Success Essentials of Yiwu Small Commodity Market

    OpenAIRE

    Han, Yu

    2013-01-01

    The objective of this thesis was to find the success factors of Yiwu Small Commodity Market. Beside this main objective, the historical reasons of Yiwu Small Commodity Market’s formation also have been analyzed. The purpose was to integrate the historical reasons and internal reasons together to get more comprehensive analysis results of Yiwu market. During the process of research, interviews of five shopkeepers in Yiwu Small Commodity Market were done. The interviews were held in April 2...

  3. Tweezers for Chimeras in Small Networks

    Science.gov (United States)

    Omelchenko, Iryna; Omel'chenko, Oleh E.; Zakharova, Anna; Wolfrum, Matthias; Schöll, Eckehard

    2016-03-01

    We propose a control scheme which can stabilize and fix the position of chimera states in small networks. Chimeras consist of coexisting domains of spatially coherent and incoherent dynamics in systems of nonlocally coupled identical oscillators. Chimera states are generally difficult to observe in small networks due to their short lifetime and erratic drifting of the spatial position of the incoherent domain. The control scheme, like a tweezer, might be useful in experiments, where usually only small networks can be realized.

  4. Small entrepreneurship in hospitality: Croatian experiences

    OpenAIRE

    Ivanovic, Slobodan; Rot, Eddy; Pretula, Miroslav

    2013-01-01

    After introductory explanations regarding the selection problems of small enterprises in the Croatian hotel industry, the author provides a number of key indicators of their role in improving the competitiveness of the Croatian hotel industry in the global tourism market. In developed tourism countries, small enterprises have a dominant share in the structure of the hotel industry, and their importance is growing even in the former socialist countries of Europe. Small hotels in Italy accounte...

  5. SMALL ENTERPRENEURSHIP IN HOSPITALITY: CROATIAN EXPERIENCES

    OpenAIRE

    Slobodan Ivanovic; Eddy Rot; Miroslav Pretula

    2013-01-01

    After introductory explanations regarding the selection problems of small enterprises in the Croatian hotel industry, the author provides a number of key indicators of their role in improving the competitiveness of the Croatian hotel industry in the global tourism market. In developed tourism countries, small enterprises have a dominant share in the structure of the hotel industry, and their importance is growing even in the former socialist countries of Europe. Small hotels in Italy accounte...

  6. Social media and small non profit organisations

    OpenAIRE

    Gulyás, A.

    2016-01-01

    This project sought to explore patterns of and views about social media adoption among small non-profit organisations and to identify mechanisms that could effectively support these organisations with their social media use. The following findings emerged from the study: • Social media are now part of the organisational infrastructure of small non-profits and the main ways in which they communicate with the public • Key variables that influence social media adoption among small no...

  7. Hydro climatic ranking of small Mediterranean islands

    OpenAIRE

    Ljubenkov, Igor

    2013-01-01

    Islands are specific environments whose natural features form the basis of social and economic development. It is particularly distinct on small islands. In hydrological terms, these are islands with surface areas between 100 and 1000 km2. There are 40 small islands in the Mediterranean Basin. Most of these have very limited water resources, due to their geological structure and precipitation regime. This paper outlines the basic geographical and climatic features of small Mediterranean islan...

  8. Small Intestinal Bacterial Overgrowth: A Comprehensive Review

    OpenAIRE

    Dukowicz, Andrew C.; Lacy, Brian E.; Levine, Gary M

    2007-01-01

    Small intestinal bacterial overgrowth (SIBO), defined as excessive bacteria in the small intestine, remains a poorly understood disease. Initially thought to occur in only a small number of patients, it is now apparent that this disorder is more prevalent than previously thought. Patients with SIBO vary in presentation, from being only mildly symptomatic to suffering from chronic diarrhea, weight loss, and malabsorption. A number of diagnostic tests are currently available, although the optim...

  9. Small Worlds: Strong Clustering in Wireless Networks

    CERN Document Server

    Brust, Matthias R

    2007-01-01

    Small-worlds represent efficient communication networks that obey two distinguishing characteristics: a high clustering coefficient together with a small characteristic path length. This paper focuses on an interesting paradox, that removing links in a network can increase the overall clustering coefficient. Reckful Roaming, as introduced in this paper, is a 2-localized algorithm that takes advantage of this paradox in order to selectively remove superfluous links, this way optimizing the clustering coefficient while still retaining a sufficiently small characteristic path length.

  10. Small is beautiful: Russian compact reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.; Perera, J.

    1994-06-30

    Large areas of Russian territory still have no centralized electricity supply making them particularly suitable for the small nuclear power plants described in this article. Thirty small reactor designs have been assessed each generating between 1 MWe and 150 MWe. Six designs were selected as winners, two in each section of small, medium and large designs, capable of producing low cost electricity, efficiently. These are described briefly. plans are underway for the construction of some of the design winners in remote locations. (UK).

  11. Vanraj Mini-Tractors: Is Small Beautiful?

    OpenAIRE

    Pratik Modi

    2008-01-01

    This case presents the dilemma of the decision maker in selecting the most appropriate market segment for Vanraj 10 HP mini-tractors — an innovation from a small farmer in Gujarat, India. Four market segments were identified: small and marginal farmers, large farmers, industries, and horticulture farmers. Vanraj was economical and possessed all the features of a big tractor. Mr. Trivedi, the decision maker, believed that the tractor would serve the needs of small and marginal farmers better, ...

  12. New Orthogonal Small Set Kasami Code Sequence

    OpenAIRE

    I Nyoman Pramaita; I G.A.G.K. Diafari; DNKP Negara; Agus Dharma

    2015-01-01

    In this paper, the authors propose the design of a new orthogonal small set Kasami code sequence generated using combination of non-orthogonal m-sequence and small set Kasami code sequence. The authors demonstrate that the proposed code sequence has comparable auto-correlation function (ACF), cross- correlation function (CCF), peak cross-correlation values with that of the existing orthogonal small set Kasami code sequence. Though the proposed code sequence has less code sequence sets than th...

  13. Dynamic capabilities in small software firms

    OpenAIRE

    Kivelä, Marianne

    2007-01-01

    In this dissertation we study dynamic capabilities in small software firms. Small software firms find themselves in highly complex and turbulent environments that require dynamic capabilities to build, integrate and configure resources. While the literature describes a portfolio of such dynamic capabilities that can help firms to adapt to changing conditions, we could not find many definitions, models and studies on these capabilities suitable with particular focus on small software firms. Fu...

  14. Small wind planning and building successful installations

    CERN Document Server

    Clark, Nolan

    2013-01-01

    This book provides a cohesive guide to achieving successful small wind installations. It is a comprehensive information resource from one of the world's most experienced small wind professionals, covering all the key issues for small wind system development, from site and machine selection to international standards compliance. Engineers who are tasked with planning and developing these small wind systems, from choosing the best site and accurately estimating likely power output to obtaining proper permitting and troubleshooting operational inefficiencies, will find this book an ess

  15. ATLAS- lowering the muon small wheel

    CERN Multimedia

    2008-01-01

    ATLAS - the two muon small wheels lowered into the cavern Like briefly separated twin sisters, ATLAS’s small wheels were once again united at the experiment’s surface building at Point 1 on St Valentine’s Day. The lowering of the small wheels into the tunnel will mark the end of the installation of detector components for the experiment. At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern.

  16. The Innovation Types Evaluation of Small Business

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-jie; TANG Bing-yong; Ronald K. Mitchell; XING Xi-rong

    2002-01-01

    The technology innovation and technology innovation capability plays an important role in management study of small business's growth and development. In this paper, the types of innovation in small business are discussed. Then, a hierarchy comprehensive fuzzy index system evaluating the types of small businesses is proposed. Because of the fuzziness of 15 factors used to analyze the small business, L-R fuzzy number is applied to describe the basic fuzzy state index. Furthermore, the corresponding fuzzy evaluation algorithm is designed. An application example indicated the effects of the methods.

  17. IMPROVEMENT OF SMALL BUSINESS CREDIT IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Klimova N. V.

    2015-12-01

    Full Text Available Small business is the basis for the development of the national economy, providing 60% of revenues in foreign countries. In Russia, this sector is developing slowly due to lack of funding. In connection with the development of small business, lending is growing in popularity in this sphere. The state develops a variety of programs to support small businesses in the form of public and private lending institutions, venture capital funds, credit unions. However, the volume of lending to small business remains relatively low, due to mistrust of banks and credit organizations in the sphere of small business. Nevertheless, it is here, according to statistics, the debt on loans is only 1.5% of the total. The article describes the features of small business lending, it analyzes the dynamics of the volume of loans granted, and the amount of debt, identifies main obstacles to obtaining loans to entrepreneurs, gives the analysis of credit conditions of small business in Russia and Germany. The problem of credit was considered from two perspectives: from the perspective of credit institutions and the banks themselves. We have developed measures to improve credit conditions, which must take into account not only credit institutions but also the state. It is necessary to provide tax incentives, encouraging the establishment and development of insurance business associations, to support the creation of specialized banks lending to small businesses, the development of cooperation of small and large banks to increase bank lending and reduce credit risks

  18. Small firm subsistence and market dimensionality

    Science.gov (United States)

    Bruggeman, Jeroen; Péli, Gábor

    2014-04-01

    In many markets, large and small firms coexist. As large firms can in principle out-compete small ones, the actual presence of the latter asks for an explanation. In ours, we focus on the dimensionality of markets, which can change as a consequence of product innovations, preference elaboration or institutions. We show that increasing market dimensionality substantially enlarges the market periphery relative to the market center, which creates new potential niches for small firms. We thereby provide a parsimonious explanation for small firm subsistence.

  19. Role of Small Airways in Asthma.

    Science.gov (United States)

    Finkas, Lindsay K; Martin, Richard

    2016-08-01

    Asthma is an inflammatory condition of both the small and large airways. Recently the small airways have gained attention as studies have shown significant inflammation in the small airways in all severities of asthma. This inflammation has correlated with peripheral airway resistance and as a result, noninvasive methods to reliably measure small airways have been pursued. In addition, recent changes in asthma inhalers have led to alterations in drug formulations and the development of extrafine particle inhalers that improve delivery to the distal airways. PMID:27401620

  20. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    OBJECTIVE: Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestin......OBJECTIVE: Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small...