As the global climate warms, a key question is how increased leaf temperatures will affect tree physiology and the coupling between leaf and air temperatures in forests. To explore the impact of increasing temperatures on plant performance in open air, we warmed leaves in the canopy of two mature evergreen forests, a temperate Eucalyptus woodland and a tropical rainforest. The leaf heaters consistently maintained leaves at a target of 4 °C above ambient leaf temperatures.
View Article and Find Full Text PDFARGONAUTE (AGO) proteins are the final effectors of small RNA-mediated transcriptional and post-transcriptional silencing pathways. Plant AGO proteins are essential for preserving genome integrity, regulating developmental processes, and in stress responses and pathogen defense. Since the discovery of the first eukaryotic AGO in Arabidopsis, our understanding of these proteins has grown exponentially throughout all the eukaryotes.
View Article and Find Full Text PDFThe nature of plant tissues has continuously hampered understanding of the spatio-temporal and subcellular distribution of RNA-guided processes. Here, we describe a universal protocol based on to investigate subcellular RNA distribution from virtually any plant species using flow cytometry sorting. This protocol includes all necessary control steps to assess the quality of the nuclear RNA purification.
View Article and Find Full Text PDFThe indole ring is present in many pharmaceutically active compounds, as in MaxiPost™ (or BMS-204352), an active pharmaceutical ingredient for post-stroke neuroprotection. Two different fluoro-oxindole-type chiral solutes derived from MaxiPost were prepared. The structural modification was placed on the NH indole function, which is probably taking part in the bioactivity, but also probably in the chromatographic enantiomer separation.
View Article and Find Full Text PDFPurpose: Early studies reported some abnormalities in saccade and vergence eye movements in children with vertigo and vergence deficiencies. The purpose of this study was to further examine saccade and vergence performance in a population of 44 children (mean age: 12.3±1.
View Article and Find Full Text PDFEnantiomeric separations of six amino-acid derivatives have been studied using packed-column supercritical fluid chromatography with two polysaccharide-based enantioselective stationary phases: cellulose tris(3,5-dimethylphenylcarbamate) and cellulose tris(3-chloro-4-methylphenylcarbamate) (Lux Cellulose-1 and -2). The effect of analyte structure on retention and separation was studied. Varied mobile phase compositions were investigated: alcohol modifier percentage was increased from 3 to 40% but smaller amounts were most effective in separating these compounds.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
October 2009
Purpose: An earlier study suggested that deficits of vergence can influence postural control via the efferent and afferent proprioceptive signals. In this study, postural control in 28 children with vertigo with normal vestibular function but with vergence abnormalities and in 19 normal children of comparable age was assessed with orthoptic tests.
Methods: A posturography platform was used to examine posture in quiet stance.
Pd(II) allyl and Pd(0) olefin complexes containing the configurationally labile ligand 1,2-bis-[4,5-dihydro-3H-dibenzo[c-e]azepino]ethane were studied as models for intermediates in Pd-catalyzed allylic alkylations. According to NMR and DFT studies, the ligand prefers C(s) conformation in both eta3-1,3-diphenylpropenyl and eta3-cyclohexenyl Pd(II) complexes, whereas in Pd(0) olefin complexes it adopts different conformations in complexes derived from the two types of allyl systems in both solution and, as verified by X-ray crystallography, in the solid state. These results demonstrate that the Pd complex is capable of adapting its structure to the reacting substrate.
View Article and Find Full Text PDFThis work reports the synthesis of new axially chiral bridged 2,2'-bipyridines 1 and pyridylmonooxazolines (pymox) 2. The potential of these new axially chiral N,N-ligands was evaluated in asymmetric catalytic cyclopropanation of styrene derivatives 22a-c with diazoesters 21a,b. While 2,2'-bipyridines 1a-c afforded the corresponding cyclopropanes 23a-f in up to 65% ee, pymoxs 2a-e gave somewhat lower enantioselectivities (up to 53% ee).
View Article and Find Full Text PDFA new and unprecedented exploitation of quinolinium thioester salts 2 in peptide bond formation is reported. These synthetic tools were assessed during the preparation of a number of dipeptides 3a-f obtained in good yields with complete stereochemical integrity. A sequential mechanism related to a prior amine capture strategy is well-established.
View Article and Find Full Text PDFUsing both SSR and AFLP markers, the genetic diversity of 30 plantains constituting a representative sample of the phenotypic diversity was assessed. The results confirmed a very narrow genetic base of this cultivar group. SSR and AFLP data support the hypothesis that these cultivars may have arisen from vegetative multiplication of a single seed.
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