Spanish National Research Council

About: Spanish National Research Council is a government organization based out in Madrid, Spain. It is known for research contribution in the topics: Population & Galaxy. The organization has 79563 authors who have published 220470 publications receiving 7698991 citations. The organization is also known as: CSIC & Consejo Superior de Investigaciones Científicas.

Recent advances in rechargeable battery materials: a chemist’s perspective

Abstract: The constant increase in global energy demand, together with the awareness of the finite supply of fossil fuels, has brought about an imperious need to take advantage of renewable energy sources. At the same time, concern over CO2 emissions and future rises in the cost of gasoline has boosted technological efforts to make hybrid and electric vehicles available to the general public. Energy storage is a vital issue to be addressed within this scenario, and batteries are certainly a key player. In this tutorial review, the most recent and significant scientific advances in the field of rechargeable batteries, whose performance is dependent on their underlying chemistry, are covered. In view of its utmost current significance and future prospects, special emphasis is given to progress in lithium-based technologies.

Biophysical controls on organic carbon fluxes in fluvial networks

Abstract: Rivers may be efficient environments for metabolizing terrestrial organic carbon that was previously thought to be recalcitrant, owing to pockets that provide geophysical opportunities by retaining material for longer, and to the adaptation of microbial communities, which has enabled them to exploit the energy that escapes upstream ecosystems. Metabolism of terrestrial organic carbon in freshwater ecosystems is responsible for a large amount of carbon dioxide outgassing to the atmosphere, in contradiction to the conventional wisdom that terrestrial organic carbon is recalcitrant and contributes little to the support of aquatic metabolism. Here, we combine recent findings from geophysics, microbial ecology and organic geochemistry to show geophysical opportunity and microbial capacity to enhance the net heterotrophy in streams, rivers and estuaries. We identify hydrological storage and retention zones that extend the residence time of organic carbon during downstream transport as geophysical opportunities for microorganisms to develop as attached biofilms or suspended aggregates, and to metabolize organic carbon for energy and growth. We consider fluvial networks as meta-ecosystems to include the acclimation of microbial communities in downstream ecosystems that enable them to exploit energy that escapes from upstream ecosystems, thereby increasing the overall energy utilization at the network level.

Yeast Carbon Catabolite Repression

Abstract: Glucose and related sugars repress the transcription of genes encoding enzymes required for the utilization of alternative carbon sources; some of these genes are also repressed by other sugars such as galactose, and the process is known as catabolite repression. The different sugars produce signals which modify the conformation of certain proteins that, in turn, directly or through a regulatory cascade affect the expression of the genes subject to catabolite repression. These genes are not all controlled by a single set of regulatory proteins, but there are different circuits of repression for different groups of genes. However, the protein kinase Snf1/Cat1 is shared by the various circuits and is therefore a central element in the regulatory process. Snf1 is not operative in the presence of glucose, and preliminary evidence suggests that Snf1 is in a dephosphorylated state under these conditions. However, the enzymes that phosphorylate and dephosphorylate Snf1 have not been identified, and it is not known how the presence of glucose may affect their activity. What has been established is that Snf1 remains active in mutants lacking either the proteins Grr1/Cat80 or Hxk2 or the Glc7 complex, which functions as a protein phosphatase. One of the main roles of Snf1 is to relieve repression by the Mig1 complex, but it is also required for the operation of transcription factors such as Adr1 and possibly other factors that are still unidentified. Although our knowledge of catabolite repression is still very incomplete, it is possible in certain cases to propose a partial model of the way in which the different elements involved in catabolite repression may be integrated.