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Academic literature on the topic 'Rha2'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Rha2"

1

Akada, R., K. Minomi, J. Kai, I. Yamashita, T. Miyakawa, and S. Fukui. "Multiple genes coding for precursors of rhodotorucine A, a farnesyl peptide mating pheromone of the basidiomycetous yeast Rhodosporidium toruloides." Molecular and Cellular Biology 9, no. 8 (August 1989): 3491–98. http://dx.doi.org/10.1128/mcb.9.8.3491-3498.1989.

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Haploid cells of mating type A of the basidiomycetous yeast Rhodosporidium toruloides secrete a mating pheromone, rhodotorucine A, which is an undecapeptide containing S-farnesyl cysteine at its carboxy terminus. To analyze the processing and secretion pathway of rhodotorucine A, we isolated both genomic and complementary DNAs encoding the peptide moiety. We identified three distinct genes, RHA1, RHA2, and RHA3, encoding four, five, and three copies of the pheromone peptide, respectively. Complementary DNA clones were classified into two types. One type was homologous to RHA1, and the other type was homologous to RHA2. Transcription start sites were identified by primer extension and S1 nuclease protection, from which the site of the initiator methionine was verified. A primary precursor of rhodotorucine A was detected as a 7-kilodalton protein by immunoprecipitation of in vitro translation products. On the basis of these results, we propose similar three-precursor structures of rhodotorucine A, each containing the amino-terminal peptide sequence Met-Val-Ala. The precursors contain three, four, or five tandem repeats of the pheromone peptide, each separated by a spacer peptide, Thr-Val-Ser(Ala)-Lys, and each precursor has the carboxy-terminal sequence Thr-Val-Ala. This structure suggests that primary precursors of rhodotorucine A do not contain canonical signal sequences.
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2

Akada, R., K. Minomi, J. Kai, I. Yamashita, T. Miyakawa, and S. Fukui. "Multiple genes coding for precursors of rhodotorucine A, a farnesyl peptide mating pheromone of the basidiomycetous yeast Rhodosporidium toruloides." Molecular and Cellular Biology 9, no. 8 (August 1989): 3491–98. http://dx.doi.org/10.1128/mcb.9.8.3491.

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Haploid cells of mating type A of the basidiomycetous yeast Rhodosporidium toruloides secrete a mating pheromone, rhodotorucine A, which is an undecapeptide containing S-farnesyl cysteine at its carboxy terminus. To analyze the processing and secretion pathway of rhodotorucine A, we isolated both genomic and complementary DNAs encoding the peptide moiety. We identified three distinct genes, RHA1, RHA2, and RHA3, encoding four, five, and three copies of the pheromone peptide, respectively. Complementary DNA clones were classified into two types. One type was homologous to RHA1, and the other type was homologous to RHA2. Transcription start sites were identified by primer extension and S1 nuclease protection, from which the site of the initiator methionine was verified. A primary precursor of rhodotorucine A was detected as a 7-kilodalton protein by immunoprecipitation of in vitro translation products. On the basis of these results, we propose similar three-precursor structures of rhodotorucine A, each containing the amino-terminal peptide sequence Met-Val-Ala. The precursors contain three, four, or five tandem repeats of the pheromone peptide, each separated by a spacer peptide, Thr-Val-Ser(Ala)-Lys, and each precursor has the carboxy-terminal sequence Thr-Val-Ala. This structure suggests that primary precursors of rhodotorucine A do not contain canonical signal sequences.
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3

Coelho, Marco A., André Rosa, Nádia Rodrigues, Álvaro Fonseca, and Paula Gonçalves. "Identification of Mating Type Genes in the Bipolar Basidiomycetous Yeast Rhodosporidium toruloides: First Insight into the MAT Locus Structure of the Sporidiobolales." Eukaryotic Cell 7, no. 6 (April 11, 2008): 1053–61. http://dx.doi.org/10.1128/ec.00025-08.

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ABSTRACT Rhodosporidium toruloides is a heterothallic, bipolar, red yeast that belongs to the Sporidiobolales, an order within a major lineage of basidiomycetes, the Pucciniomycotina. In contrast to other basidiomycetes, considerably less is known about the nature of the mating type (MAT) loci that control sexual reproduction in this lineage. Three genes (RHA1, RHA2, and RHA3) encoding precursors of the MAT A1 pheromone (rhodotorucine A) were previously identified and formed the basis for a genome walking approach that led to the identification of additional MAT genes in complementary mating strains of R. toruloides. Two mating type-specific alleles encoding a p21-activated kinase (PAK; Ste20 homolog) were found between the RHA2 and RHA3 genes, and identification in MAT A2 strains of a gene encoding a presumptive pheromone precursor enabled prediction of the structure of rhodotorucine a. In addition, a putative pheromone receptor gene (STE3 homolog) was identified upstream of RHA1. Analyses of genomic data from two closely related species, Sporobolomyces roseus and Sporidiobolus salmonicolor, identified syntenic regions that contain homologs of all the above-mentioned genes. Notably, six novel pheromone precursor genes were uncovered, which encoded, similarly to the RHA genes, multiple tandem copies of the peptide moiety. This suggests that this structure, which is unique among fungal lipopeptide pheromones, seems to be prevalent in red yeasts. Species comparisons provided evidence for a large, multigenic MAT locus structure in the Sporidiobolales, but no putative homeodomain transcription factor genes (which are present in all basidiomycetous MAT loci characterized thus far) could be found in any of the three species in the vicinity of the MAT genes identified.
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4

Nguyen, Duong. "EFFECT OF DIFFERENT TYPES OF RICE HUSK ASH ON SOME GEOTECHNICAL PROPERTIES OF CEMENT-ADMIXED SOIL." Iraqi Geological Journal 53, no. 2C (September 30, 2020): 1–12. http://dx.doi.org/10.46717/igj.53.2c.1rs-2020-09-01.

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Rice husk ash (RHA) is an agricultural residue and has shown great potential for soil stabilization. However, the research on the utilization of RHA for soft soil improvement using cement deep mixing method is still limited and the efficiency of using different RHA types for soil improvement needs to be clarified. In this study, the effect of different RHA types on Atterberg limits, unconfined compressive strength (UCS), and elastic modulus (E50) of soil-cement mixtures will be investigated. Two types of RHA which obtained from open fire burning (RHA1) and burning in a furnace under controlled conditions of temperature and duration of burning (RHA2), were used for this study. The RHA contents from 0 to 15% and 10% cement of the dry weight of the soil were used to treat the soft soil. The research results show that the types of RHA insignificantly affect the change in Atterberg limits of cement-admixed soil. Regarding the soil strength, the RHA2 shows a higher efficiency in the enhancement of treated soil strength at 28 days of curing than the RHA1. The addition of 12% RHA2 to the cement-admixed soil can increase the UCS and E50 values of treated soil by more than 50%.
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5

Bhende, Prasanna M., and Susan M. Egan. "Amino Acid-DNA Contacts by RhaS: an AraC Family Transcription Activator." Journal of Bacteriology 181, no. 17 (September 1, 1999): 5185–92. http://dx.doi.org/10.1128/jb.181.17.5185-5192.1999.

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ABSTRACT RhaS, an AraC family protein, activates rhaBADtranscription by binding to rhaI, a site consisting of two 17-bp inverted repeat half-sites. In this work, amino acids in RhaS that make base-specific contacts with rhaI were identified. Sequence similarity with AraC suggested that the first contacting motif of RhaS was a helix-turn-helix. Assays of rhaB-lacZactivation by alanine mutants within this potential motif indicated that residues 201, 202, 205, and 206 might contact rhaI. The second motif was identified based on the hypothesis that a region of especially high amino acid similarity between RhaS and RhaR (another AraC family member) might contact the nearly identical DNA sequences in one major groove of their half-sites. We first made targeted, random mutations and then made alanine substitutions within this region of RhaS. Our analysis identified residues 247, 248, 250, 252, 253, and 254 as potentially important for DNA binding. A genetic loss-of-contact approach was used to identify whether any of the RhaS amino acids in the first or second contacting motif make base-specific DNA contacts. In motif 1, we found that Arg202 and Arg206 both make specific contacts with bp −65 and −67 in rhaI 1, and that Arg202 contacts −46 and Arg206 contacts −48 inrhaI 2. In motif 2, we found that Asp250 and Asn252 both contact the bp −79 in rhaI 1. Alignment with the recently crystallized MarA protein suggest that both RhaS motifs are likely helix-turn-helix DNA-binding motifs.
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6

Christova, Nelly, Boryana Tuleva, Rashel Cohen, Galya Ivanova, Georgy Stoev, Margarita Stoilova-Disheva, and Ivanka Stoineva. "Chemical Characterization and Physical and Biological Activities of Rhamnolipids Produced by Pseudomonas aeruginosa BN10." Zeitschrift für Naturforschung C 66, no. 7-8 (August 1, 2011): 394–402. http://dx.doi.org/10.1515/znc-2011-7-811.

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Pseudomonas aeruginosa BN10 isolated from hydrocarbon-polluted soil was found to produce rhamnolipids when cultivated on 2% glycerol, glucose, n-hexadecane, and n-alkanes. The rhamnolipids were partially purified on silica gel columns and their chemical structures elucidated by combination of one- and two-dimensional 1H and 13C NMR techniques and ESI-MS analysis. Eight structural rhamnolipid homologues were identified: Rha-C10- C8, Rha-C10-C10, Rha-C10-C12:1, Rha-C10-C12, Rha2-C10-C8, Rha2-C10-C10, Rha2-C10-C12:1, and Rha2-C10-C12. The chemical composition of the rhamnolipid mixtures produced on different carbon sources did not vary with the type of carbon source used. The rhamnolipid mixture produced by Pseudomonas aeruginosa BN10 on glycerol reduced the surface tension of pure water from 72 to 29 mN m-1 at a critical micellar concentration of 40 mg l-1, and the interfacial tension was 0.9 mN m-1. The new surfactant product formed stable emulsions with hydrocarbons and showed high antimicrobial activity against Gram-positive bacteria. The present study shows that the new strain Pseudomonas aeruginosa BN10 demonstrates enhanced production of the di-rhamnolipid Rha2-C10-C10 on all carbon sources used. Due to its excellent surface and good antimicrobial activities the rhamnolipid homologue mixture from Pseudomonas aeruginosa BN10 can be exploited for use in bioremediation, petroleum and pharmaceutical industries.
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Wickstrum, Jason R., Jeff M. Skredenske, Vinitha Balasubramaniam, Kyle Jones, and Susan M. Egan. "The AraC/XylS Family Activator RhaS Negatively Autoregulates rhaSR Expression by Preventing Cyclic AMP Receptor Protein Activation." Journal of Bacteriology 192, no. 1 (October 23, 2009): 225–32. http://dx.doi.org/10.1128/jb.00829-08.

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ABSTRACT The Escherichia coli RhaR protein activates expression of the rhaSR operon in the presence of its effector, l-rhamnose. The resulting RhaS protein (plus l-rhamnose) activates expression of the l-rhamnose catabolic and transport operons, rhaBAD and rhaT, respectively. Here, we further investigated our previous finding that rhaS deletion resulted in a threefold increase in rhaSR promoter activity, suggesting RhaS negative autoregulation of rhaSR. We found that RhaS autoregulation required the cyclic AMP receptor protein (CRP) binding site at rhaSR and that RhaS was able to bind to the RhaR binding site at rhaSR. In contrast to the expected repression, we found that in the absence of both RhaR and the CRP binding site at the rhaSR promoter, RhaS activated expression to a level comparable with RhaR activation of the same promoter. However, when the promoter included the RhaR and CRP binding sites, the level of activation by RhaS and CRP was much lower than that by RhaR and CRP, suggesting that CRP could not fully coactivate with RhaS. Taken together, our results indicate that RhaS negative autoregulation involves RhaS competition with RhaR for binding to the RhaR binding site at rhaSR. Although RhaS and RhaR activate rhaSR transcription to similar levels, CRP cannot effectively coactivate with RhaS. Therefore, once RhaS reaches a relatively high protein concentration, presumably sufficient to saturate the RhaS-activated promoters, there will be a decrease in rhaSR transcription. We propose a model in which differential DNA bending by RhaS and RhaR may be the basis for the difference in CRP coactivation.
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Cristache, Corina Marilena, Eugenia Eftimie Totu, Daniel Petre, Roxana Buga, Gheorghe Cristache, and Tiberiu Totu. "Melatonin and Hyaluronic Acid Mixture as a Possible Therapeutic Agent in Dental Medicine." Revista de Chimie 69, no. 8 (September 15, 2018): 1996–99. http://dx.doi.org/10.37358/rc.18.8.6461.

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The present work reports an efficient procedure for a simultaneous determination of melatonin (MEL) and hyaluronic acid (HA) mixture applying first derivative UV-Vis spectrophotometry. At selected wavelength (205 nm), the linearity range for each component of the mixture was established. The linear regression correlation coefficients for the direct UV-Vis spectra (RHA2 = 0.9627) and their first derivate (RHA2 = 0.9986) put in evidence a better fit for the derivative procedure. Through such simple analysis method, it was possible to emphasize that each component of MEL-HA mixture preserves its identity and characteristic properties. Consequently, the association of MEL and HA biomolecules could be used for obtaining a complex therapeutic agent with extensive applications in dental medicine.
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Wickstrum, Jason R., and Susan M. Egan. "Amino Acid Contacts between Sigma 70 Domain 4 and the Transcription Activators RhaS and RhaR." Journal of Bacteriology 186, no. 18 (September 15, 2004): 6277–85. http://dx.doi.org/10.1128/jb.186.18.6277-6285.2004.

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ABSTRACT The RhaS and RhaR proteins are transcription activators that respond to the availability of l-rhamnose and activate transcription of the operons in the Escherichia coli l-rhamnose catabolic regulon. RhaR activates transcription of rhaSR, and RhaS activates transcription of the operon that encodes the l-rhamnose catabolic enzymes, rhaBAD, as well as the operon that encodes the l-rhamnose transport protein, rhaT. RhaS is 30% identical to RhaR at the amino acid level, and both are members of the AraC/XylS family of transcription activators. The RhaS and RhaR binding sites overlap the −35 hexamers of the promoters they regulate, suggesting they may contact the σ70 subunit of RNA polymerase as part of their mechanisms of transcription activation. In support of this hypothesis, our lab previously identified an interaction between RhaS residue D241 and σ70 residue R599. In the present study, we first identified two positively charged amino acids in σ70, K593 and R599, and three negatively charged amino acids in RhaR, D276, E284, and D285, that were important for RhaR-mediated transcription activation of the rhaSR operon. Using a genetic loss-of-contact approach we have obtained evidence for a specific contact between RhaR D276 and σ70 R599. Finally, previous results from our lab separately showed that RhaS D250A and σ70 K593A were defective at the rhaBAD promoter. Our genetic loss-of-contact analysis of these residues indicates that they identify a second site of contact between RhaS and σ70.
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Wickstrum, Jason R., Jeff M. Skredenske, Ana Kolin, Ding J. Jin, Jianwen Fang, and Susan M. Egan. "Transcription Activation by the DNA-Binding Domain of the AraC Family Protein RhaS in the Absence of Its Effector-Binding Domain." Journal of Bacteriology 189, no. 14 (May 18, 2007): 4984–93. http://dx.doi.org/10.1128/jb.00530-07.

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ABSTRACT The Escherichia coli l-rhamnose-responsive transcription activators RhaS and RhaR both consist of two domains, a C-terminal DNA-binding domain and an N-terminal dimerization domain. Both function as dimers and only activate transcription in the presence of l-rhamnose. Here, we examined the ability of the DNA-binding domains of RhaS (RhaS-CTD) and RhaR (RhaR-CTD) to bind to DNA and activate transcription. RhaS-CTD and RhaR-CTD were both shown by DNase I footprinting to be capable of binding specifically to the appropriate DNA sites. In vivo as well as in vitro transcription assays showed that RhaS-CTD could activate transcription to high levels, whereas RhaR-CTD was capable of only very low levels of transcription activation. As expected, RhaS-CTD did not require the presence of l-rhamnose to activate transcription. The upstream half-site at rhaBAD and the downstream half-site at rhaT were found to be the strongest of the known RhaS half-sites, and a new putative RhaS half-site with comparable strength to known sites was identified. Given that cyclic AMP receptor protein (CRP), the second activator required for full rhaBAD expression, cannot activate rhaBAD expression in a ΔrhaS strain, it was of interest to test whether CRP could activate transcription in combination with RhaS-CTD. We found that RhaS-CTD allowed significant activation by CRP, both in vivo and in vitro, although full-length RhaS allowed somewhat greater CRP activation. We conclude that RhaS-CTD contains all of the determinants necessary for transcription activation by RhaS.
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Dissertations / Theses on the topic "Rha2"

1

Marangoni, Davide. "On Derived de Rham cohomology." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0095.

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La cohomologie de de Rham dérivée a été introduite par Luc Illusie en 1972, suite à ses travaux sur le complexe cotangent. Cette théorie semble avoir été oubliée jusqu’aux travaux récents de Bhatt et Beilinson, qui ont donné diverses applications, notamment en théorie de Hodge p-adique. D’autre part, la cohomologie de Rham dérivée intervient de manière cruciale dans une conjecture de Flach-Morin sur les valeurs spéciales des fonctions zêta des schémas arithmétiques. Dans cette thèse, on se propose d’étudier et de calculer la cohomologie de de Rham dérivée dans certains cas
The derived de Rham complex has been introduced by Illusie in 1972. Its definition relies on the notion of cotangent complex. This theory seems to have been forgot until the recents works by Be˘ılinson and Bhatt, who gave several applications, in particular in p-adic Hodge Theory. On the other hand, the derived de Rham cohomology has a crucial role in a conjecture by Flach-Morin about special values of zeta functions for arithmetic schemes. The aim of this thesis is to study and compute the Hodge completed derived de Rham complex in some cases
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2

Davis, Christopher (Christopher James). "The overconvergent de Rham-Witt complex." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50593.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2009.
Includes bibliographical references (p. 83-84).
We define the overconvergent de Rham-Witt complex ... for a smooth affine variety over a perfect field in characteristic p. We show that, after tensoring with Q, its cohomology agrees with Monsky-Washnitzer cohomology. If dim C < p, we have an isomorphism integrally. One advantage of our construction is that it does not involve a choice of lift to characteristic zero. To prove that the cohomology groups are the same, we first define a comparison map ... (See Section 4.1 for the notation.) We cover our smooth affine C with affines B each of which is finite, tale over a localization of a polynomial algebra. For these particular affines, we decompose ... into an integral part and a fractional part and then show that the integral part is isomorphic to the Monsky-Washnitzer complex and that the fractional part is acyclic. We deduce our result from a homotopy argument and the fact that our complex is a Zariski sheaf with sheaf cohomology equal to zero in positive degrees. (For the latter, we lift the proof from [4] and include it as an appendix.) We end with two chapters featuring independent results. In the first, we reinterpret several rings from p-adic Hodge theory in such a way that they admit analogues which use big Witt vectors instead of p-typical Witt vectors. In this generalization we check that several familiar properties continue to be valid. In the second, we offer a proof that the Frobenius map on W(...) is not surjective for p > 2.
by Christopher Davis.
Ph.D.
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3

Rivers, Damien M. R. "Characterization of the Rhizobiaceae protein RhaK." ASM, 2013. http://hdl.handle.net/1993/30289.

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In Rhizobium leguminosarum the ABC transporter responsible for rhamnose transport is dependent on RhaK, a sugar kinase that is necessary for the catabolism of rhamnose. It was hypothesized that RhaK has two separate functions; phosphorylation of rhamnose, and an unknown interaction with the rhamnose ABC transporter. To address this hypothesis a linker-scanning mutagenesis of rhaK was carried out. Two generated variants (RhaK72 and RhaK73) were found to maintain kinase activity, but were severely impaired in rhamnose transport function. Structural modelling suggested that both RhaK72 and RhaK73 affect surface exposed residues in two distinct regions localized to one face of the protein. This suggests that this proteins face may play a role in a protein-protein interaction that affects rhamnose transport. Using a two-hybrid system, an N-terminal and a C-teminal fragment of RhaK were both shown to interact with the N-terminal fragment of RhaT. These fragments span the regions that contain the rhaK73 and rhaK72 inserts respectively. When the rhaK72 and rhaK73 insert alleles were cloned and assayed using the two-hybrid system, these they were unable to interact with the RhaT fragment, suggesting these inserts abolish transport by interfering with a physical interaction between RhaT and RhaK. A phylogeny was generated based on the amino acid sequence of RhaK like proteins found in syntenous opereons. To gain insight into what residues may constitute a binding domain a PRALINE alignment of the orthologous kinases was combined with secondary structure analysis, known informative mutations, and functional residue predictions. A putative 12 amino acid binding site was identified using this method. An alanine scanning mutagenesis and subsequent two-hybrid analysis was carried out on this region. The substitution of any of these residues greatly affected the interaction between RhaT and RhaK. Although heterologous complementation of RhaK is possible, cosmid complementation anomalies and phylogenetic analysis of RhaK indicates the R. leguminosarum and S. meliloti kinases are different. Through a series of heterologous complementation experiments, enzyme assays, gene fusions, and transport experiments we show that the R. leguminosarum kinase is capable of directly phosphorylating rhamnose and rhamnulose, whereas the Sinorhizobium meliloti kinase does not have rhamnose kinase activity.
May 2015
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Silva, Junior Soares da. "Introdução à cohomologia de De Rham." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-16112017-101825/.

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Começamos definindo a cohomologia clássica de De Rham e provamos alguns resultados que nos permitem calcular tal cohomologia de algumas variedades diferenciáveis. Com o intuito de provar o Teorema de De Rham, escolhemos fazer a demonstração utilizando a noção de feixes, que se mostra como uma generalização da ideia de cohomologia. Como a cohomologia de De Rham não é a única que se pode definir numa variedade, a questão da unicidade dá origem a teoria axiomática de feixes, que nos dará uma cohomologia para cada feixe dado. Mostraremos que a partir da teoria axiomática de feixes obtemos cohomologias, além das cohomologias clássicas de De Rham, a cohomologia clássica singular e a cohomologia clássica de Cech e mostraremos que essas cohomologias obtidas a partir da noção axiomática são isomorfas as definições clássicas. Concluiremos que se nos restringirmos a apenas variedades diferenciáveis, essas cohomologias são unicamente isomorfas e este será o teorema de De Rham.
We begin by defining De Rhams classical cohomology and we prove some results that allow us a calculation of the cohomology of some differentiable manifolds. In order to prove De Rhams Theorem, we chose to make a demonstration using a notion of sheaves, which is a generalization of the idea of cohomology. Since De Rhams cohomology is not a only one that can be made into a variety, the question of unicity gives rise to axiomatic theory of sheaves, which give us a cohomology for each sheaf given. We will show that from the axiomatic theory of sheaves we obtain cohomologies, besides the classical cohomologies of De Rham, a singular classical cohomology and a classical cohomology of Cech and we will show that cohomologies are obtained from the axiomatic notion are classic definitions. We will conclude that if we restrict ourselves to only differentiable manifolds, these cohomologies are uniquely isomorphic and this will be De Rhams theorem.
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5

Apaza, Nuñez Danny Joel. "El Teorema de De Rham-Saito." Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/95679.

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The theorem of De Rham-Saito is a generalization of a lemma due to De Rham [3], which was announced and used in [7] by Kyoji Saito, as noproof of this theorem was available, Le Dung Trang encouraged to Saito to publish the proof that can be seen in [8], which indirectly encourages us to detail the proof in this article for the many applications it has,we highlight the Godbillon-Vey algorithm [4]; in the proof of Theorem classical Frobenius given in [2]; in [6] we see some interesting applications, in the proof of Frobenius theorem with singularities [5]. In [1] we givefull details of the proof given by Moussu and Rolin.
El teorema de De Rham-Saito es una generalización de un lema debido a De Rham [3], el cual fue enunciado y usado en [11] por Kyoji Saito, al no haber prueba de este teorema Le Dung Trang anima a Saito a publicar la prueba que puede ser vista en [12], lo cual indirectamente nos motiva a detallarla prueba en este articulo por las muchas aplicaciones que tiene, destacamos el algoritmo de Godbillon-Vey [5]; en la prueba del Teorema de Frobenius clásico dada en [2]; en [8] vemos unas aplicaciones interesantes; en la prueba del Teorema de Frobenius con singularidades [7]; en [1] se detalla la prueba realizada por Moussu y Rolin [10].
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6

Ewald, Christian-Oliver. "Hochschild homology and de Rham cohomology of stratifolds." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965191931.

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7

Stacey, Andrew Edgell. "A construction of semi-infinite de Rham cohomology." Thesis, University of Warwick, 2001. http://wrap.warwick.ac.uk/55501/.

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The purpose of this thesis is to describe a construction of semi-infinite de Rham cohomology for infinite dimensional manifolds equipped with the extra structure of a polarisation. We describe the construction for finite dimensions and show how it extends to other cases; in particular the semi-infinite. We then define variations for Hilbert manifolds which allow us to calculate the semi-infinite cohomology of the projective space and the Grassmannians of a polarised Hilbert space. Finally, we consider some of the implications of these results for index theory, in particular for the Witten genus.
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8

Costeanu, Viorel 1975. "On the 2-typical de Rham-Witt complex." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32242.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2004.
Includes bibliographical references (p. 55).
In this thesis we introduce the 2-typical de Rham-Witt complex for arbitrary commutative, unital rings and log-rings. We describe this complex for the rings Z and Z(2), for the log-ring (Z(2), M) with the canonical log-structure, and we describe its behaviour under polynomial extensions. In an appendix we also describe the p-typical de Rham-Witt complex of (Z(p), M) for p odd.
by Viorel Costeanu.
Ph.D.
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9

Mendes, Thais Zanutto. "Do cálculo à cohomologia: cohomologia de de Rham." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-17072012-144946/.

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Neste trabalho, estudamos a cohomologia de de Rham e métodos para os seus cálculos. Finalizamos com aplicações da cohomologia de de Rham em teoremas da topologia
In this work we study the de Rham cohomology and methods for its calculations. We close it with applications of the Rham cohomology in theorems from topology
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10

Munoz, Bertrand Ruben. "Coefficients en cohomologie de De Rham-Witt surconvergente." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMC205.

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Deligne a défini dans les années 70 le complexe de De Rham-Witt, qui permit à Illusie de prouver un théorème de comparaison avec la cohomologie cristalline. Ce résultat fut ensuite étendu par Etesse aux coefficients. En 2004, Bloch démontra que le théorème de comparaison cohomologique étendu aux coefficients d'Etesse possédait une interprétation plus profonde : sous certaines conditions, on obtient en fait une équivalence de catégories entre des cristaux et des connexions de De Rham Witt.Plus récemment, Davis, Langer et Zink ont introduit un complexe de De Rham-Witt surconvergent et démontré des théorèmes de comparaison avec les cohomologies de Monsky-Washnitzer et rigide. Ces derniers furent ensuite étendus aux coefficients par Ertl, qui démontra notamment un quasi-isomorphisme de cohomologie avec les isocristaux surconvergents.On peut alors légitimement se demander si les résultats de Bloch possèdent une variante surconvergente : c'est-à-dire que l'on aimerait pouvoir obtenir une interprétation des isocristaux surconvergents pour la cohomologie de De Rham-Witt surconvergente. On peut y parvenir en considérant des connexions de De Rham-Witt surconvergentes comme définies par Ertl, pour lesquelles on peut raisonnablement espérer retrouver les mêmes opérations cohomologiques que pour les F-isocristaux.Cette question fut la motivation de cette thèse, et le théorème principal de ce travail y répond en partie positivement. Pour y parvenir, il est nécessaire d'expliciter la structure locale du complexe de De Rham-Witt surconvergent, et de redéfinir la notion de surconvergence afin de pouvoir mieux contrôler la convergence des produits de différentielles de De Rham-Witt
Under a few assumptions, we prove an equivalence of category between a subcategory of F-isocristals on a smooth algebraic variety and overcongergent integrable De Rham-Witt connections. We do so by giving an equivalent definition of overconvergence, and by studying the explicit local structure of the De Rham-Witt complex
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Books on the topic "Rha2"

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Thakʻ, Ñāṇʻ. Rhā rhā phve phve hāsa mhatʻ cu. Thokʻ kranʻʹ, [Rangoon]: Vānʻʺ Mraṅʻʹ ʼOṅʻ Cā pe, 1999.

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Nuiṅʻ, ʾOṅʻ. Phve phve rhā rhā Tuiṅʻ ̋raṅʻ ̋che ̋paññā. Maṅgalā toṅ ññvanʻg, Ranʻ kunʻ: Kyoʻ Ññvanʻʹ Raññʻ Cā pe, 2005.

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Nuiṅʻ, ʾOṅʻ. Phve phve rhā rhā Tuiṅʻ ̋raṅʻ ̋che ̋paññā. Maṅgalā toṅ ññvanʻg, Ranʻ kunʻ: Kyoʻ Ññvanʻʹ Raññʻ Cā pe, 2005.

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Ñāṇobhāsa. Nibbānʻ rhā naññʻʺ nissaraññʻʺ. Ranʻ kunʻ: Doʻ Rvhe ʼImʻ, 2000.

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La, Ne. Vipassanā rhā puṃ toʻ. Ranʻ kunʻ: Vaṅʻʺ Moʻ Ūʺ Cā pe Phranʻʹ khyī reʺ, 1991.

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Lvaṅʻ, Mraṅʻʹ. Mre sacʻ rhā sū. [Ranʻ kūn: Cā pe Bimānʻ, 1990.

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RHA, McGuire Edward, McGuire Sally, and Cronin Anthony, eds. Edward McGuire, RHA. Blackrock, Co. Dublin: Irish Academic Press, 1991.

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Taṅʻ, Cinʻ. Pu gaṃ rhā puṃ toʻ. Vaṅʻʺ Mraṅʻʹ ʼOṅʻ Cā pe: [Phranʻʹ khyi reʺ], ʼĀʺ Mānʻ Sacʻ Cā pe, 1998.

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Candāvarābhivaṃsa. Mratʻ so rhā phve khraṅʻʺ. Kraññʻʹ mraṅʻ tuiṅʻ, [Rangoon]: Cinʻ Panʻʺ Mruiṅʻ Cā pe, 2001.

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Williams, Rhydwen. Pedwarawd: Pryddest mewn pedair rhan. [Caernarfon?]: Barddas, 1986.

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Book chapters on the topic "Rha2"

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Jänich, Klaus. "De Rham Cohomology." In Vector Analysis, 195–213. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4757-3478-2_11.

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Tu, Loring W. "De Rham Theory." In An Introduction to Manifolds, 273–316. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-7400-6_8.

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Naber, Gregory L. "de Rham Cohomology." In Topology, Geometry, and Gauge Fields, 297–350. New York, NY: Springer New York, 2000. http://dx.doi.org/10.1007/978-1-4757-6850-3_5.

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Lück, Wolfgang. "De Rham-Kohomologie." In Algebraische Topologie, 228–35. Wiesbaden: Vieweg+Teubner Verlag, 2005. http://dx.doi.org/10.1007/978-3-322-80241-5_14.

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Nakahara, Mikio. "De-Rham-Kohomologiegruppen." In Differentialgeometrie, Topologie und Physik, 237–54. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-45300-1_6.

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Lee, John M. "De Rham Cohomology." In Introduction to Smooth Manifolds, 440–66. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4419-9982-5_17.

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Lee, John M. "De Rham Cohomology." In Introduction to Smooth Manifolds, 388–409. New York, NY: Springer New York, 2003. http://dx.doi.org/10.1007/978-0-387-21752-9_15.

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Huber, Annette. "De Rham cohomology." In Lecture Notes in Mathematics, 57–60. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/bfb0095510.

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Gilkey, Peter, JeongHyeong Park, and Ramón Vázquez-Lorenzo. "de Rham Cohomology." In Aspects of Differential Geometry II, 17–44. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-031-02408-5_2.

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Naber, Gregory L. "de Rham Cohomology." In Topology, Geometry and Gauge fields, 257–302. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-7895-0_5.

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Conference papers on the topic "Rha2"

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Scheiblechner, Peter. "Effective de Rham cohomology." In the 37th International Symposium. New York, New York, USA: ACM Press, 2012. http://dx.doi.org/10.1145/2442829.2442873.

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XING, Boyang, Yunhui HOU, Zhenyan GUO, Dongjiang ZHANG, Liang CHEN, Yongliang Yang, Jianhua Luo, Rongzhong LIU, and Rui GUO. "Analysis of the distribution of BAD generated during the normal penetration of a variable cross-section EFP on RHA." In 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/hvis2019-003.

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Abstract The purpose of this study is to analyse how the thickness of Rolled Homogeneous Armor (RHA) and impact velocity of an Explosively Formed Projectile (EFP) influence the middle mass behind-armor debris (BAD) when a variable cross-section EFP penetrates RHA normally. Numerical simulation is adopted, the thickness of RHA varies from 10mm to 70mm, and the impact velocity of the EFP varies from 1650m/s to 1860m/s. The results indicate that: (1) when the impact velocity of the EFP is 1650m/s and the thickness of RHA varies from 10mm to 70mm, p1g of the RHA and EFP decreases with increasing H0. The thin target could be used to produce a large proportion of the middle mass BAD from RHA (including BAD from the EFP and BAD from the RHA and EFP). (2) When the impact velocity of the EFP varies from 1650m/s to 1860m/s and the thickness of the RHA is 40mm, p1g of the RHA is less than 50%, p1g of the EFP is more than 70%, and p1g of the RHA and EFP is more than 50%.
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George, Mark, and Julie Brichacek. "Radiation hardened 32-bit processor (RH32)." In 15th International Communicatons Satellite Systems Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1994. http://dx.doi.org/10.2514/6.1994-1104.

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Musso Laespiga, Marcos, and Leonardo Behak Katz. "Performance of Low-Volume Roads with Wearing Course Layer of Silty Sandy Soil Modified with Rice Husk Ash and Lime." In CIT2016. Congreso de Ingeniería del Transporte. Valencia: Universitat Politècnica València, 2016. http://dx.doi.org/10.4995/cit2016.2016.3451.

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Rice husk ash (RHA) is a by-product of rice milling. Its use as soil stabilizer is a way to replace the final disposal with environmental benefit. However, RHA is not cementitious itself but when mixed with lime forms cements which improve the soil properties. A research of performance of a silty sandy soil modified with RHA and lime as wearing course layer of low-volume roads was conducted through two full-scale test sections with different pavements built in Artigas, northern Uruguay. The alkaline reactivity of RHA is low because the husk burning is not controlled. The soil-RHA-lime mix design was conducted according to the Thompson’s Method. The pavement test sections were monitored through deflection measures by Benkelman beam and observations of surface condition. The deflections decreased over time in both test sections due to the development of cementation of the study materials. After one year, the dust emission was reduced, the wet skid resistance of pavement surfaces improved and there was not rutting. The researched pavements have had a good performance under the existing traffic and environmental conditions, demonstrating that wearing course layer of silty sand modified with RHA and lime is an alternative to improve the condition of low-volume roads and to replace the final disposal of RHA, with environmental, social and economic benefits.DOI: http://dx.doi.org/10.4995/CIT2016.2016.3451
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Zeng, Tao, Devesh Upadhyay, Harold Sun, Eric Curtis, and Guoming G. Zhu. "Regenerative Hydraulic Assisted Turbocharger." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64927.

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Engine downsizing and down-speeding are essential in order to meet future US fuel economy mandates. Turbocharging is one technology to meet these goals. Fuel economy improvements must, however, be achieved without sacrificing performance. One significant factor impacting drivability on turbocharged engines is typically referred to as, “Turbo-Lag”. Since Turbo-lag directly impacts the driver’s torque demands, it is usually perceptible as an undesired slow transient boost response or as a sluggish torque response. High throughput turbochargers are especially susceptible to this dynamic and are often equipped with variable geometry turbines (VGT) to mitigate some of this effect. Assisted boosting techniques that add power directly to the TC shaft from a power source that is independent of the engine have been shown to significantly reduce turbo-lag. Single unit assisted turbochargers are either electrically assisted or hydraulically assisted. In this study a regenerative hydraulically assisted turbocharger (RHAT) system is evaluated. A custom designed RHAT system is coupled to a light duty diesel engine and is analyzed via vehicle and engine simulations for performance and energy requirements over standard test cycles. Supplier provided performance maps for the hydraulic turbine, hydraulic turbo pump were used. A production controller was coupled with the engine model and upgraded to control the engagement and disengagement of RHAT, with energy management strategies. Results show some interesting dynamics and shed light on system capabilities especially with regard to the energy balance between the assist and regenerative functions. Design considerations based on open loop simulations are used for sizing the high pressure accumulator. Simulation results show that the proposed RHAT turbocharger system can significantly improve engine transient response. Vehicle level simulations that include the driveline were also conducted and showed potential for up to 4% fuel economy improvement over the FTP 75 drive cycle. This study also identified some technical challenges related to optimal design and operation of the RHAT. Opportunities for additional fuel economy improvements are also discussed.
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Malakhaltsev, M. A. "De Rham like cohomology of geometric structures." In Proceedings of the 10th International Conference on DGA2007. WORLD SCIENTIFIC, 2008. http://dx.doi.org/10.1142/9789812790613_0042.

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Swartz, Morris L. "Electroweak radiative corrections and measurements of Rhad." In The workshop on the tau/charm factory. AIP, 1996. http://dx.doi.org/10.1063/1.49265.

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Idusuyi, Nosa, Peter Ozaveshe Oviroh, and Adetoye Henry Adekoya. "A Study on the Corrosion and Mechanical Properties of an Al6063 Reinforced With Egg Shell Ash and Rice Husk Ash." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-86662.

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Aluminium based metal matrix composites (MMCs) have received considerable attention in the last decade for its potential industrial applications. One of the challenges encountered using Aluminium based MMCs is understanding the influence of the reinforcement particles on the corrosion resistance and mechanical properties. In this study the corrosion behaviour and mechanical properties of Al6063 reinforced with egg shell ash and rice husk ash were investigated. Waste Egg Shell Ash (ESA) and Rice Husk Ash (RHA) 212 μm in size were used to produce the composites with 10 wt% of reinforcements via stir casting technique. The RHA and ESA were added in the ratios of 10:0, 7.5:2.5, 5:5, 2.5:7.5, 0:10. Unreinforced Al6063 was used as baseline material. Immersion tests, potentiodynamic polarization techniques, tensile tests, optical microscopy (OM) and scanning electron microscopy (SEM) were used to characterize the composites. The results showed that reinforcing with 7.5 wt% RHA + 2.5 wt% ESA provided the highest resistance to corrosion. Generally, a reduction in the corrosion rates were observed for the reinforced composites as the wt% of RHA increased. Porosity levels of the composites reduced with an increase in the percentage of ESA in the matrix. Microstructural characterization using SEM and OM revealed a distribution of pits on the composite surfaces which was more severe with increasing RHA percentage. The UTS (ultimate tensile stress) results revealed that the composite containing 10 wt% RHA had the maximum value of 161 MPa. The results demonstrate that rice husk ash and eggshell ash can be useful in producing low cost Aluminium composites with improved corrosion resistance and tensile properties.
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Abedloo, Ebrahim, Soheil Gholami, and Hamid D. Taghirad. "Eye-RHAS manipulator: From kinematics to trajectory control." In 2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM). IEEE, 2015. http://dx.doi.org/10.1109/icrom.2015.7367761.

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Akintola, Sarah, and Akinwale Akintola. "Performance Evaluation of Local Material Rice Husk Ash Under Downhole Conditions with the Addition of Basic Oil Well Additives Antifoam, Fluid Loss, Dispersant and Retarder on Oil Well Cementing." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/207144-ms.

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Abstract The effect of RHA on Compressive Strength as well as other parameters like Consistency and Rheological properties etc. on Class G cement slurry is studied. The following additives were used; Rice Husk Ash (for Compressive Strength), Guinea Corn Husk Ash (Retarder) and other liquid additives which are fluid Loss Additive, Antifoam, Dispersant, Retarder and Water in the formulation of the cement slurry. This research is a comparative analysis based on experimental study on the effectiveness of the various additives on the cement slurry using pure Class G cement slurry combined with all liquid additives as a control. At a Bottomhole Circulating Temperature of 140°C, the Compressive Strength tests carried out on the slurry samples showed that the strength of the concrete increases as the concentration of the RHA increases with time of curing, also the compressive strength started to increase. The best Compressive Strength result was obtained with the percentages of cement replaced by 13.01% RHA. The strength showed impressive increase with time, with highest compressive strength encountered in 24 hours. The Thickening Time of the set Cement Slurry was considered using Class G cement and different percentage of RHA. The final Thickening Time decreases with increase in Rice Husk Ash. Decrease in the setting time was noticeable from 1.87 hrs (at 13.01% RHA) from 40bc to 100 bc. At BHST of 700°C increasing the ash concentration resulted in decrease in the Plastic Viscosities (PV) and increase in the Yield Points of the slurries. The results indicate that the slurries formulated using this ash has viscosities which are within the recommended values showing it is desirable to pump such slurry. For both 124°C and Bottom Hole Pressure of 7700psi the amount of fluid loss increases as the percentage of RHA added increases but it is below 50cp which is acceptable.
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Reports on the topic "Rha2"

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Widianto, D. Suprayogo, Sudarto, and I. D. Lestariningsih. Implementasi Kaji Cepat Hidrologi (RHA) di Hulu DAS Brantas, Jawa Timu. World Agroforestry Centre (ICRAF), 2010. http://dx.doi.org/10.5716/wp10338.pdf.

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Xie, Xiaowei S. Experimental Treatment of Prostate Cancer Models with Rh2, an Isolated Ginsenoside Compound. Fort Belvoir, VA: Defense Technical Information Center, March 2003. http://dx.doi.org/10.21236/ada415533.

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Carpita, Nicholas C., Ruth Ben-Arie, and Amnon Lers. Pectin Cross-Linking Dynamics and Wall Softening during Fruit Ripening. United States Department of Agriculture, July 2002. http://dx.doi.org/10.32747/2002.7585197.bard.

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Our study was designed to elucidate the chemical determinants of pectin cross-linking in developing fruits of apple and peach and to evaluate the role of breakage cross-linkages in swelling, softening, and cell separation during the ripening. Peaches cell walls soften and swell considerably during the ripening, whereas apples fruit cells maintain wall firmness but cells separate during late stages of ripening. We used a "double-reduction" technique to show that levels of non-methyl esters of polyuronic acid molecules were constant during the development and ripening and decreased only in overripe fruit. In peach, methyl and non-methyl esters increased during the development and decreased markedly during the ripening. Non-methyl ester linkages in both fruit decreased accompanied fruit softening. The identity of the second component of the linkage and its definitive role in the fruit softening remain elusive. In preliminary examination of isolated apples cell walls, we found that phenolic compounds accumulate early in wall development but decrease markedly during ripening. Quantitative texture analysis was used to correlate with changes to wall chemistry from the fresh-picked ripe stage to the stage during storage when the cell separation occurs. Cell wall composition is similar in all cultivars, with arabinose as the principal neutral sugar. Extensive de-branching of these highly branched arabinans pre-stages softening and cell-cell separation during over-ripening of apple. The longer 5-arabinans remain attached to the major pectic polymer rhamnogalacturonan I (RG I) backbone. The degree of RG I branching, as judged from the ratios of 2-Rha:2,4-Rha, also decreases, specially after an extensive arabinan de-branching. Loss of the 4-Rham linkages correlated strongly with the softening of the fruit. Loss of the monomer or polymer linked to the RG I produce directly or indirectly the softening of the fruit. This result will help to understand the fruit softening and to have better control of the textural changes in fruit during the ripening and especially during the storage. 'Wooliness', an undesirable mealy texture that is induced during chilling of some peach cultivars, greatly reduces the fruit storage possibilities. In order to examine the hypothesis that the basis for this disorder is related to abnormality in the cell wall softening process we have carried out a comparative analysis using the resistant cultivar, Sunsnow, and a sensitive one, Hermosa. We investigated the activity of several pectin- and glycan-modifying enzymes and the expression of their genes during ripening, chilling, and subsequent shelf-life. The changes in carbohydrate status and in methyl vs. non-methyl uronate ester levels in the walls of these cultivars were examined as well to provide a basis for comparison of the relevant gene expression that may impact appearance of the wooly character. The activities of the specific polygalacturonase (PGase) and a CMC-cellulase activities are significantly elevated in walls of peaches that have become wooly. Cellulase activities correlated well with increased level of the transcript, but differential expression of PGase did not correspond with the observed pattern of mRNA accumulation. When expression of ethylene biosynthesis related genes was followed no significant differences in ACC synthase gene expression was observed in the wooly fruit while the normal activation of the ACC oxidase was partially repressed in the Hermosa wooly fruits. Normal ripening-related loss of the uronic acid-rich polymers was stalled in the wooly Hermosa inconsistent with the observed elevation in a specific PGase activity but consistent with PG gene expression. In general, analysis of the level of total esterification, degree of methyl esterification and level of non-methyl esters did not reveal any major alterations between the different fruit varieties or between normal and abnormal ripening. Some decrease in the level of uronic acids methyl esterification was observed for both Hermosa and Sunsnow undergoing ripening following storage at low temperature but not in fruits ripening after harvest. Our results support a role for imbalanced cell wall degradation as a basis for the chilling disorder. While these results do not support a role for the imbalance between PG and pectin methyl esterase (PME) activities as the basis for the disorder they suggest a possible role for imbalance between cellulose and other cell wall polymer degradation during the softening process.
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Sharon, Amir, and Maor Bar-Peled. Identification of new glycan metabolic pathways in the fungal pathogen Botrytis cinerea and their role in fungus-plant interactions. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7597916.bard.

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The involvement of glycans in microbial adherence, recognition and signaling is often a critical determinant of pathogenesis. Although the major glycan components of fungal cell walls have been identified there is limited information available on its ‘minor sugar components’ and how these change during different stages of fungal development. Our aim was to define the role of Rhacontaining-glycans in the gray mold disease caused by the necrotrophic fungus B. cinerea. The research was built on the discovery of two genes, Bcdhand bcer, that are involved in formation of UDP-KDG and UDP-Rha, two UDP- sugars that may serve as donors for the synthesis of cell surface glycans. Objectives of the proposed research included: 1) To determine the function of B. cinereaBcDh and BcEr in glycan biosynthesis and in pathogenesis, 2) To determine the expression pattern of BcDH and BcERand cellular localization of their encoded proteins, 3) Characterize the structure and distribution of Rha- containing glycans, 4) Characterization of the UDP-sugar enzymes and potential of GTs involved in glycanrhamnosylation. To address these objectives we generated a series of B. cinereamutants with modifications in the bchdhand bcergenes and the phenotype and sugar metabolism in the resulting strains were characterized. Analysis of sugar metabolites showed that changes in the genes caused changes in primary and secondary sugars, including abolishment of rhamnose, however abolishment of rhamnose synthesis did not cause changes in the fungal phenotype. In contrast, we found that deletion of the second gene, bcer, leads to accumulation of the intermediate sugar – UDP- KDG, and that such mutants suffer from a range of defects including reduced virulence. Further analyses confirmed that UDP-KDG is toxic to the fungus. Studies on mode of action suggested that UDP-KDG might affect integrity of the fungal cell wall, possibly by inhibiting UDP-sugars metabolic enzymes. Our results confirm that bcdhand bcerrepresent a single pathway of rhamnose synthesis in B. cinerea, that rhamnose does not affect in vitro development or virulence of the fungus. We also concluded that UDP-KDG is toxic to B. cinereaand hence UDP-KDG or compounds that inhibit Er enzymes and lead to accumulation of UDP-KDG might have antifungal activity. This toxicity is likely the case with other fungi, this became apparent in a collaborative work with Prof. Bart Thomma of Wageningen University, NETHERLANDS . We have shown the deletion of ER mutant in Verticillium dahlia gave plants resistance to the fungal infection.
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