(árabe - العربية‎) 2024 الرزنامة الدراسية العلمية

El proyecto “Calendario Científico Escolar 2024” ha consistido en la elaboración de un calendario dirigido al alumnado de educación primaria y secundaria obligatoria. Cada día se ha recogido un aniversario científico o tecnológico como, por ejemplo, nacimientos de personas de estos ámbitos o conmemoraciones de hallazgos destacables. Además, el calendario se acompaña de una guía didáctica con orientaciones para el aprovechamiento educativo transversal del calendario en las clases, incluyendo actividades adaptadas a cada rango de edad y al alumnado con necesidades especiales. Se trata de la cuarta edición de este proyecto de divulgación científica.El proyecto “Calendario Científico Escolar 2024” ha consistido en la elaboración de un calendario dirigido al alumnado de educación primaria y secundaria obligatoria. Cada día se ha recogido un aniversario científico o tecnológico como, por ejemplo, nacimientos de personas de estos ámbitos o conmemoraciones de hallazgos destacables. Además, el calendario se acompaña de una guía didáctica con orientaciones para el aprovechamiento educativo transversal del calendario en las clases, incluyendo actividades adaptadas a cada rango de edad y al alumnado con necesidades especiales. Se trata de la cuarta edición de este proyecto de divulgación científica.Instituto Geológico y Minero de España (IGME); Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA); Centro de Biología Molecular Severo Ochoa (CBMSO); Instituto Español de Oceanografía (IEO); Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA); Museo Nacional de Ciencias Naturales (MNCN); Centre d'Estudis Avançats de Blanes (CEAB); Institut d’Investigació en Intel.ligéncia Artificial (IIIA); Institut de Microelectrònica de Barcelona - Centre Nacional de Microelectrònica (IMB-CNM); Institut de Ciències del Mar (ICM, CSIC). Discapacitodos; Mujeres con Ciencia; Comisión Mujeres y Ciencia de la Sociedad Geológica de España; Asociación Española para el Avance de la Ciencia (AEAC); PRISMA – Asociación para la diversidad afectivo-sexual y de género en ciencia, tecnología e innovación; Círculo Escéptico; Universitat de les Illes Balears (UIB); Asociaţia Secular-Umanistă din România; Civiencia; Universidad Autónoma de Madrid; Evento Ciencia; Europa Laica; Canaima; Universitat Autònoma de Barcelona; Fundación Odón de BuenPeer reviewe

X-ray diffraction microstructural analysis of swelling by ethylene glycol in two reference clay minerals

Kaolinite and montmorillonite are two clay minerals with different structures: dioctahedral 1:1 without layer charge and dioctahedral 2:1 with low layer charge. X-ray-diffraction microstructural analysis of two fractions of two reference clays (with kaolinite or montmorillonite) from the Clay Minerals Society Source Clay Repository were performed by the Voigt function method to provide microstructural data not available in the baseline studies of this Repository. A rough agreement was found between crystallite sizes determined from X-ray diffraction patterns and from images by field-emission scanning electron microscopy. In addition, the influence of swelling by ethylene-glycol on crystallite size was studied by the mentioned method. Two factors were found to affect the crystallite size variation in ethylene-glycol-treated clay minerals: (i) the increase of the unit cell in [001] direction due to the interlayer absorption of ethylene glycol molecules in the case of swelling minerals and (ii) the physisorption at the surfaces of the crystallites. Both effects operate in the case of montmorillonite, whereas just the latter one is expected in kaolinite

New C 2-symmetry diols accumulating one stereogenic axis and two stereogenic centers

Herein we report a protocol for the enantioselective synthesis of the three stereoisomers of 1,1′-(1,1′-binaphthalene-2,2′-diyl)bis(2,2, 2-trifluoroethanol) and their characterization. These compounds, that combine axial and central chirality, might present interesting properties for enantiorecognition. Different reduction processes were applied to racemic and enantiopure 1,1′-(1,1′-binaphthalene-2,2′-diyl)bis(2,2,2- trifluoroethanone) allowing the isolation of the corresponding ketols, 2,2,2-trifluoro-1-[2′-(2,2,2-trifluoro-1-hydroxyethyl)-1, 1′-binaphthalen-2-yl]ethanone, and the named diols. © 2012 Elsevier Ltd. All rights reserved.Peer Reviewe

Reaction between N-alkylhydroxylamines and chiral enoate esters: More experimental evidence for a cycloaddition-like process, a rationale based on DFT theoretical calculations, and stereoselective synthesis of new enantiopure β-amino acids

The reactions between N-benzyl- and N-methylhydroxylamine and chiral enoate esters, derived from D-glyceraldehyde and (-)-verbenone, respectively, have been investigated. Theoretical calculations show that the most favorable mechanism involves the concerted cycloaddition of the hydroxylamine to the substrate. This result is in good agreement with the stereospecificity observed when the trisubstituted olefins are used. The open-chain adducts have been isolated when the processes are carried out at low temperatures and for short reaction times. These compounds evolve to the corresponding isoxazolidinones on standing at room temperature or under acid catalysis. The high π-facial diastereoselection has been rationalized on the basis of steric effects induced by the dioxolane ring for D-glyceraldehyde derivatives or by the cyclobutane gem-dimethyl substitution for esters prepared from (-)-verbenone. As an application of these reactions, new β-amino acids have been synthesized in a highly efficient and stereocontrolled manner.Fil: Moglioni, Albertina Gladys. Universitat Autònoma de Barcelona; España. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Muray, Elena. Universitat Autònoma de Barcelona; EspañaFil: Castillo, José A.. Universitat Autònoma de Barcelona; EspañaFil: Álvarez Larena, Ángel. Universitat Autònoma de Barcelona; EspañaFil: Moltrasio, Graciela Y.. Universidad de Buenos Aires; ArgentinaFil: Branchadell, Vicenç. Universitat Autònoma de Barcelona; EspañaFil: Ortuño, Rosa M.. Universitat Autònoma de Barcelona; Españ

Morphological and molecular identification of filamentous fungi isolated from cosmetic powders

Seven fungi were isolated from 50 samples of cosmetic powders. Morphological analyses and ribosomal DNA Internal Transcribed Spacers sequencing were performed which allowed the discrimination of the isolated fungi as Aspergillus fumigatus, Penicillium sp., and Cladosporium sp. which could have, among their species, potentially pathogenic microorganisms

Introgression in peripheral populations and colonization shape the genetic structure of the coastal shrub Armeria pungens

The coastal shrub Armeria pungens has a disjunct Atlantic-Mediterranean distribution. The historic range expansion underlying this distribution was investigated using the nuclear internal transcribed spacer region, three plastid regions (namely trnL-F, trnS-fM and matK) and morphometric data. A highly diverse ancestral lineage was identified in southwest Portugal. More recently, two areas have been colonized: (1) Corsica and Sardinia, where disjunct Mediterranean populations have been established as a result of the long-distance dispersal of Portuguese genotypes, and (2) the southern part of the Atlantic range, Gulf of Cadiz, where a distinct lineage showing no genetic differentiation among populations occurs. Genetic consequences of colonization seem to have been more severe in the Gulf of Cadiz than in Corsica-Sardinia. Although significant genetic divergence is associated with low plastid diversity in the Gulf of Cadiz, in Corsica-Sardinia, the loss of plastid haplotypes was not accompanied by divergence from disjunct Portuguese source populations. In addition, in its northernmost and southernmost populations, A. pungens exhibited evidence for ancient or ongoing introgression from sympatric congeners. Introgression might have created novel genotypes able to expand beyond the latitudinal margins of the species or, alternatively, these genotypes may be the result of surfing of alleles from other species in demographic equilibrium into peripheral populations of A. pungens. Our results highlight the evolutionary significance of genetic drift following the colonization of new areas and the key role of introgression in range expansion