Los auroros de la huerta de Murcia

En número dedicado a: Murci

La ciudad medieval como escenario: primeras manifestaciones del teatro popular

Reunimos aquí el material relacionado con una serie de fiestas que se desarrollan en la ciudad medieval, haciendo hincapié en las fiestas populares y en la organización del espacio urbano medieval como espacio teatral

Biorefineries: Achievements and challenges for a bio-based economy

Funding This work was supported by a project (FQM-176) financed by the Junta de Andalucía. FM-M, acknowledges the support from the Global Challenges Research Fund from Swansea University, and from the Royal Society of Chemistry Enablement Grant (E21-7051491439).Climate change, socioeconomical pressures, and new policy and legislation are driving a decarbonization process across industries, with a critical shift from a fossil-based economy toward a biomass-based one. This new paradigm implies not only a gradual phasing out of fossil fuels as a source of energy but also a move away from crude oil as a source of platform chemicals, polymers, drugs, solvents and many other critical materials, and consumer goods that are ubiquitous in our everyday life. If we are to achieve the United Nations’ Sustainable Development Goals, crude oil must be substituted by renewable sources, and in this evolution, biorefineries arise as the critical alternative to traditional refineries for producing fuels, chemical building blocks, and materials out of non-edible biomass and biomass waste. State-of-the-art biorefineries already produce cost-competitive chemicals and materials, but other products remain challenging from the economic point of view, or their scaled-up production processes are still not sufficiently developed. In particular, lignin’s depolymerization is a required milestone for the success of integrated biorefineries, and better catalysts and processes must be improved to prepare bio-based aromatic simple molecules. This review summarizes current challenges in biorefinery systems, while it suggests possible directions and goals for sustainable development in the years to come.Project (FQM-176) financed by the Junta de AndalucíaGlobal Challenges Research Fund from Swansea UniversityRoyal Society of Chemistry Enablement Grant (E21-7051491439

Disjointly Homogeneous Banach Lattices and Applications

This is a survey on disjointly homogeneous Banach lattices and their applications. Several structural properties of this class are analyzed. In addition we show how these spaces provide a natural framework for studying the compactness of powers of operators allowing for a unified treatment of well-known results

A Proposal to Define Adaptive Learning Designs

Abstract. This paper outlines a framework to describe adaptive learning designs where definitions as the instructional design method, the type of tests, the learning style approach, and the adaptive rules are not prescribed. Standardized metadata based on IMS is used to guarantee the reusability and interoperability of the elements. The framework proposes, also, to adjust the learning design taking into account the student knowledge and the learning style of both the learner and the learning activities by means of adaptive rule definitions. These rules are defined using a set of elements (based on IMS LD) and they describe adaptive statements, techniques and students’ stereotypes

Characterization of the iron-regulated desA promoter of Streptomyces pilosus as a system for controlled gene expression in actinomycetes

BACKGROUND: The bioavailability of iron is quite low since it is usually present as insoluble complexes. To solve the bioavailability problem microorganisms have developed highly efficient iron-scavenging systems based on the synthesis of siderophores that have high iron affinity. The systems of iron assimilation in microorganisms are strictly regulated to control the intracellular iron levels since at high concentrations iron is toxic for cells. Streptomyces pilosus synthesizes the siderofore desferrioxamine B. The first step in desferrioxamine biosynthesis is decarboxylation of L-lysine to form cadaverine, a desferrioxamine B precursor. This reaction is catalyzed by the lysine decarboxylase, an enzyme encoded by the desA gene that is repressed by iron. RESULTS: The binding of the DmdR (acronym for divalent metal dependent repressor) to the desA promoter in presence of Fe(2+ )or other divalent ions has been characterized. A 51 bp DNA fragment of the desA promoter containing the 9 bp inverted repeat was sufficient for binding of the DmdR repressor, as observed by the electrophoretic mobility shift assay. The desA mobility shift was prevented by neutralizing DmdR with anti-DmdR antibodies or by chelating the divalent metal in the binding reaction with 2,2'-dipyridyl. Binding to the desA promoter was observed with purified DmdR repressors of Streptomyces coelicolor or Rhodococcus fascians suggesting that there is a common mechanism of iron-regulation in actinomycetes. The complete desA promoter region was coupled using transcriptional fusions to the amy reporter gene (encoding α-amylase) in low copy or multicopy Streptomyces vectors. The iron-regulated desA promoter was induced by addition of the iron chelating agent 2,2'-dipyridyl resulting in a strong expression of the reporter gene. CONCLUSIONS: The iron-regulated desA promoter can be used for inducible expression of genes in Streptomyces species, as shown by de-repression of the promoter when coupled to a reporter gene