The C23A system, an exmaple of quantitative control of plant growth associated with a data base

The architecture of the C23A (Chambers de Culture Automatique en Atmosphere Artificielles) system for the controlled study of plant physiology is described. A modular plant growth chambers and associated instruments (I.R. CO2 analyser, Mass spectrometer and Chemical analyser); network of frontal processors controlling this apparatus; a central computer for the periodic control and the multiplex work of processors; and a network of terminal computers able to ask the data base for data processing and modeling are discussed. Examples of present results are given. A growth curve analysis study of CO2 and O2 gas exchanges of shoots and roots, and daily evolution of algal photosynthesis and of the pools of dissolved CO2 in sea water are discussed

Study of the relationship between photosynthesis, respiration, transpiration, and mineral nutrition in wheat

The growth of wheat (triticum aestivum) was studied in an enclosed controlled environment for a period of 70 days. The exchange of gases (photosynthesis, respiration), water (transpiration) and the consumption of mineral elements (nitrogen, phosphorus, potassium) were continuously measured. The dynamical relations observed in the different physiological functions, under the influence of growth and in response to environment modifications are presented. The influence of carbon dioxide content during growth (normal or double percentage) was made clear

Void-Assisted Ion-Paired Proton Transfer at Water-Ionic Liquid Interfaces.

At the water-trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate ([P14,6,6,6 ][FAP]) ionic liquid interface, the unusual electrochemical transfer behavior of protons (H(+) ) and deuterium ions (D(+) ) was identified. Alkali metal cations (such as Li(+) , Na(+) , K(+) ) did not undergo this transfer. H(+) /D(+) transfers were assisted by the hydrophobic counter anion of the ionic liquid, [FAP](-) , resulting in the formation of a mixed capacitive layer from the filling of the latent voids within the anisotropic ionic liquid structure. This phenomenon could impact areas such as proton-coupled electron transfers, fuel cells, and hydrogen storage where ionic liquids are used as aprotic solvents

Mol Biol Cell

The exon junction complex (EJC) is loaded onto mRNAs as a consequence of splicing and regulates multiple posttranscriptional events. MLN51, Magoh, Y14, and eIF4A3 form a highly stable EJC core, but where this tetrameric complex is assembled in the cell remains unclear. Here we show that EJC factors are enriched in domains that we term perispeckles and are visible as doughnuts around nuclear speckles. Fluorescence resonance energy transfer analyses and EJC assembly mutants show that perispeckles do not store free subunits, but instead are enriched for assembled cores. At the ultrastructural level, perispeckles are distinct from interchromatin granule clusters that may function as storage sites for splicing factors and intermingle with perichromatin fibrils, where nascent RNAs and active RNA Pol II are present. These results support a model in which perispeckles are major assembly sites for the tetrameric EJC core. This subnuclear territory thus represents an intermediate region important for mRNA maturation, between transcription sites and splicing factor reservoirs and assembly sites

Lessons from non-canonical splicing

Recent improvements in experimental and computational techniques that are used to study the transcriptome have enabled an unprecedented view of RNA processing, revealing many previously unknown non-canonical splicing events. This includes cryptic events located far from the currently annotated exons and unconventional splicing mechanisms that have important roles in regulating gene expression. These non-canonical splicing events are a major source of newly emerging transcripts during evolution, especially when they involve sequences derived from transposable elements. They are therefore under precise regulation and quality control, which minimizes their potential to disrupt gene expression. We explain how non-canonical splicing can lead to aberrant transcripts that cause many diseases, and also how it can be exploited for new therapeutic strategies

Chauffage solaire des gaz

The authors calculate numerically the profiles of temperatures of a gas circulating in forced convection through a porous cavity open to a concentrated solar radiation. They study the influence of some parameters of the system and compare their apparatus to the one studied by G. Olalde, M. Daguenet and J. L. Peube.Les auteurs calculent numériquement les répartitions de température d'un gaz circulant en convection forcée à travers une cavité poreuse soumise à un rayonnement solaire concentré. Ils étudient l'influence des divers paramètres du système et comparent ses performances énergétiques à celles obtenues par le dispositif étudié par G. Olalde, M. Daguenet et J. L. Peube

Theoretical study of gas heated in a porous material subjected to a concentrated solar radiation

The authors calculate analytically and numerically temperature distribution in the solid (porous material) and the fluid (gas) from a system of adimensional equations composed of one differential equation of order 4 and another one of order 2 with constant coefficient. An experimental reactor was constructed for the verification of the model; it was designed to be used with 6.5 kW solar furnace of Solar Energy Laboratory in Odeillo (France)

Site-isolated porphyrin catalysts in imprinted polymers

A meso-tetraaryl ruthenium porphyrin complex having four polymerizable vinylbenzoxy groups (2) has been synthesized by reaction of pyrrole with 4-(vinylbenzoxy)benzaldehyde and subsequent metalation with [Ru-3(CO)(12)]. The porphyrin complex was immobilized by copolymerization with ethylene glycol dimethacrylate. The resulting polymer P2 was found to catalyze the oxidation of alcohols alkanes with 2,6-dichloropyridine N-oxide without activation by mineral acids. Under similar conditions, the homogeneous catalyst 2 was completely inefficient. By using diphenylamino-methane and 1-aminoadamantane as coordinatively bound templates during the polymerization procedure, the molecularly imprinted polymers P3 and P4 have been synthesized. Compared with the polymer P2, the imprinted catalysts displayed a significantly increased activity with rate enhancements of up to a factor of 16

Wheat response to CO2 enrichment: effect of photosynthetic and photorespiratory characteristics

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