Search results for "MARA"
showing 10 items of 343 documents
Floral synorganization and its influence on mechanical isolation and autogamy in Marantaceae
2012
The flowers of Marantaceae (∼ 550 species) exhibit a highly derived pollination mechanism within Zingiberales, with a rapid and irreversible style movement based on a close synorganization of different floral parts. Given the complexity of the structure, we assume that little variation is possible if functionality is to be maintained. To test this, we investigated how much floral diversity exists in the clade and whether this diversity potentially influences the breeding system and placement of pollen on the pollinator. Flowers of 66 species covering the five major phylogenetic clades of the family were analysed. All species are similar in their basic flower construction: the fleshy stamino…
Chemical Composition of the Leaf Oil ofLantana camara
2005
The essential oil of the fresh leaves of Lantana camera growing in Dehra Dun was analyzed by GC and GC/MS. The major constituents identified in the oil included β-caryophyllene (23.3%), α-humulene (11.5%), germacrene D (10.9%), davanone (7.3%) and γ-curcumene (6.3%).
Nord-Pas-de-Calais, Lille, rue Chaude Rivière, rue Dumont d'Urville : rapport de diagnostic
2015
L’opération de diagnostic archéologique a livré la présence de plusieurs occupations anciennes. La présence la plus ancienne est matérialisée par une fosse peu profonde de la Tène D2. Plusieurs fossés d’enclos d’orientation nord-sud ou est-ouest ont été repérés à divers endroits de la parcelle, ainsi que quelques structures domestiques. Ils sont datés du début de la période gallo-romaine. Du mobilier archéologique du Bas-Empire a également été récolté dans le comblement de structures plus récentes, ce qui laisse présager de la présence de structures de cette période.Un niveau de débordement de la rivière du Becquerel a scellé ces niveaux antiques. Sur ce niveau a été repéré une occupation d…
Desarrollo de métodos analíticos para evaluar la efectividad de cosméticos antipolución
2021
La contaminación ambiental es un problema tanto local como global de gran importancia en la actualidad. En concreto, la contaminación urbana es uno de los principales peligros para la salud humana, y en especial para la salud de la piel, lo que ha provocado un incremento de la concienciación y la preocupación con respecto a los niveles de contaminación en aire. La aparición de cosméticos antipolución, destinados a combatir estos efectos negativos sobre la salud humana, es el resultado de dicha preocupación. Sin embargo, el desarrollo de metodologías analíticas adecuadas para la evaluación de su efectividad es un gran desafío. Por ello, la presente Tesis se centra en el desarrollo de métodos…
A dammarane-type saponin from the roots of Ampelozizyphus amazonicus.
1993
A new C31 dammarane-type triterpenoid saponin has been isolated from the roots of Ampelozizyphus amazonicus. Its structure was elucidated to be ampelozigenin-15 alpha-O-acetyl- 3-O-alpha-L-rhamnopyranosyl-(1--2)-beta-D-glucopyranoside by 1D and 2D NMR spectroscopic methods, and by chemical transformations. Ampelozigenin is a novel triterpene, (20R,22R)-16 beta,22:16 alpha, 30-diepoxydammar-24(24')- methylene-3 beta, 15 alpha, 20-triol.
C4-dicarboxylate metabolons: Interaction of C4-dicarboxylate transporters of Escherichia coli with cytosolic enzymes
2021
AbstractMetabolons represent the structural organization of proteins for metabolic or regulatory pathways. Here the interaction of enzymes fumarase FumB and aspartase AspA with the C4-DC transporters DcuA and DcuB of Escherichia coli was tested by a bacterial two-hybrid (BACTH) assay in situ, or by co-chromatography (mSPINE). DcuB interacted strongly with FumB and AspA, and DcuA with AspA. The fumB-dcuB and the dcuA-aspA genes encoding the respective proteins are known for their colocalization on the genome and the production of co-transcripts. The data consistently suggest the formation of DcuB/FumB, DcuB/AspA and DcuA/AspA metabolons in fumarate respiration for the uptake of L-malate, or …
Experimental evidence for proton motive force-dependent catalysis by the diheme-containing succinate:menaquinone oxidoreductase from the Gram-positiv…
2006
In Gram-positive bacteria and other prokaryotes containing succinate:menaquinone reductases, it has previously been shown that the succinate oxidase and succinate:menaquinone reductase activities are lost when the transmembrane electrochemical proton potential, Deltap, is abolished by the rupture of the bacteria or by the addition of a protonophore. It has been proposed that the endergonic reduction of menaquinone by succinate is driven by the electrochemical proton potential. Opposite sides of the cytoplasmic membrane were envisaged to be separately involved in the binding of protons upon the reduction of menaquinone and their release upon succinate oxidation, with the two reactions linked…
Dammarane triterpenes of Salvia hierosolymitana
1990
Abstract Salvilymitone and salvilymitol, two new triterpenoids isolated from Salvia hierosolymitana , have been shown to be 7β,25-dihydroxy-(20 S ,24 R )-epoxydammaran-3-one and (20 S ,24 R )-epoxydammaran-3β,7α,25-triol, respectively. The absolute stereochemistry of these triterpenoids has been established by an X-ray diffraction analysis of a 25,26,27-trinor derivative obtained by degradation of both compounds. In addition, four previously known triterpenoids were isolated from the same source.
Succinate dehydrogenase functioning by a reverse redox loop mechanism and fumarate reductase in sulphate-reducing bacteria.
2006
Sulphate- or sulphur-reducing bacteria with known or draft genome sequences (Desulfovibrio vulgaris, Desulfovibrio desulfuricans G20, Desulfobacterium autotrophicum [draft], Desulfotalea psychrophila and Geobacter sulfurreducens) all contain sdhCAB or frdCAB gene clusters encoding succinate : quinone oxidoreductases. frdD or sdhD genes are missing. The presence and function of succinate dehydrogenase versus fumarate reductase was studied. Desulfovibrio desulfuricans (strain Essex 6) grew by fumarate respiration or by fumarate disproportionation, and contained fumarate reductase activity. Desulfovibrio vulgaris lacked fumarate respiration and contained succinate dehydrogenase activity. Succi…
1987. La protesta estudiantil contra el Gobierno socialista. La Generalitat Valenciana y el conflicto estudiantil. "El acuerdo valenciano" del consel…
2006
1987. La protesta estudiantil contra el Gobierno socialista. La Generalitat Valenciana y el conflicto estudiantil. "El acuerdo valenciano" del conseller Ciprià Císcar. La hegemonía socialista en la Comunidad Valenciana. El PSPV-PSOE. 1982-1995 La protesta estudiantil contra el Gobierno socialista. En diciembre de 1986 estallaría un conflicto entre el Ministerio de Educación y los estudiantes de Bachillerato -BUP- y formación profesional -FP-, que se extendería a profesores, y que tendría paralizada la enseñanza más de dos meses. Las manifestaciones y huelgas generales eran nacionales contra las políticas del ministro de Educación y Ciencia, José María Maravall, y que afectaría a la Generali…