445 research outputs found
Observación de la inferencia en la compresión lectora de 2º de Primaria
El objetivo del trabajo es analizar el proceso de inferencia propio de la comprensión lectora. Se realiza una revisión bibliográfica con atención especial a los procesos cognitivos propios del lector y sucesivamente se señalan las líneas de trabajo. El trabajo se divide básicamente en dos grandes apartados: En primer lugar, un marco teórico en el que se tratan aspectos tan importantes como la lectura. Se analizarán brevemente los procesos implicados en ella, los principales modelos generales sobre lectura y los métodos que actualmente existen para enseñar aprender a leer. Se tratan los principales componentes de la comprensión lectora así como los diferentes niveles de comprensión lectora haciendo especial hincapié en las inferencias. En segundo lugar, tomando como referencia dicho marco teórico, hemos elaborado una prueba para primer ciclo de Primaria. Por último, y para terminar, realizaré una conclusión de este trabajoGrado en Educación Primari
Investigating the transformations of polyoxoanions using mass spectrometry and molecular dynamics
The reactions of [γ-SiW10O36]8– represent one of the most important synthetic gateways into a vast array of polyoxotungstate chemistry. Herein, we set about exploring the transformation of the lacunary polyoxoanion [β2-SiW11O39]8– into [γ-SiW10O36]8– using high-resolution electrospray mass spectrometry, density functional theory, and molecular dynamics. We show that the reaction proceeds through an unexpected {SiW9} precursor capable of undertaking a direct β → γ isomerization via a rotational transformation. The remarkably low-energy transition state of this transformation could be identified through theoretical calculations. Moreover, we explore the significant role of the countercations for the first time in such studies. This combination of experimental and the theoretical studies can now be used to understand the complex chemical transformations of oxoanions, leading to the design of reactivity by structural control
Gearing motion in cogwheel pairs of molecular rotors: weak-coupling limit
Variable-temp. (VT) crystal structures, VT 1H spin-lattice relaxation in static crystals, and DFT modeling of the rotational barriers of BCP rotators in cryst. arrays of a rod-like mol. contg. two 1,3-bis(ethynyl)bicyclo[1.1.1]pentane (BCP) units demonstrate that a correlated gearing motion occurs in the limit of a weak coupling between two rotors in a pair
Changing gears to neutral in a polymorph of one-dimensional arrays of cogwheel-like pairs of molecular rotors
We report on a polymorph (2) of an amphidynamic crystal of molecular rods with two helical 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators where half of the rod-like molecules appear to be shifted with respect to their closest neighbours. This translation takes cogwheel-like pairs of rotators apart in the lattice in such a way that their motion becomes uncorrelated. This property is to be contrasted with the highly correlated motion found to govern the rotators in a recently-published polymorph 1 of the same material. As with polymorph 1, this motion is shown to take place independently of mutations in the handedness of the rotators and of the ‘mutamer’-induced second harmonic generation
Static Modulation Wave of Arrays of Halogen Interactions Transduced to a Hierarchy of Nanoscale Change Stimuli of Crystalline Rotors Dynamics
Here we present a study where what can be seen as a static modulation wave encompassing four successive arrays of interacting iodine atoms in cryst. 1,4-Bis((4\u27-(iodoethynyl)phenyl) ethynyl)bicyclo[2,2,2]octane rotors changes the structure from one-half mol. to three-and-a-half mols. in the asym. unit below a phase transition at 105 K. The remarkable finding is that the total 1H spin-lattice relaxation rate, T1-1, of unprecedented complexity to date in mol. rotors, is the weighted sum of the relaxation rates of the four contributing rotors relaxation rates, each with distinguishable exchange frequencies reflecting Arrhenius parameters with different activation barriers (Ea) and attempt frequencies (τo-1). This allows us to show in tandem with rotor-environment interaction energy calcns. how the dynamics of mol. rotors are able to decode structural information from their surroundings with remarkable nanoscale precision
Adsorption of Direct Blue 78 using chitosan and cyclodextrins as adsorbents
The dyeing industry is one of the most polluting in the world. The adsorption of dyes by polymeric matrixes can be used to minimize the discharge of dyes into the environment. In the present study, chitosan-NaOH and β-cyclodextrin-epichlorohydrin polymers were used to remove the dye Direct Blue 78 from a wastewater model. To understand the adsorption behavior of Direct Blue 78 onto the polymers, adsorption rate and maximum adsorption capacity were calculated using kinetic tests and isotherm curves respectively. The kinetic data and mechanism of the adsorption process were analyzed by three models and the equilibrium data by three adsorption isotherms; also the different thermodynamic parameters were calculated. Results showed that the adsorption process follows pseudo-second-order kinetics in both polymers and the Langmuir isotherm best-fitted data for chitosan-NaOH polymer and the Freundlich isotherm for the β-CDs-EPI polymer. The adsorption process is exothermic in both cases and spontaneous for the β-CDs-EPI polymer to a certain temperature and not spontaneous for the chitosan-NaOH polymer and β-CDs-EPI polymer at higher temperatures. The complementary action of an advanced oxidation process eliminated >99% of the dye from water. The coupled process seems to be suitable for reducing the environmental impact of the dyeing industry.Ciencias de la Alimentació
Llonín, grotte
Le siteLa grotte de Llonín se trouve dans le bassin du Cares-Deva marqué par le relief montagneux du massif central des Picos de Europa. Le long de cette vallée s’échelonnent onze autres grottes ornées : La Loja, Subores, Coímbre, Traúno, Los Canes, Peña del Alba, Falo, Berodia, Soberaos, El Bosque et Covaciella (Rasilla Vives 2014).Bien que le vestibule de la grotte ait été connu depuis longtemps, l’accès à l’intérieur de la grotte n’a été ouvert qu’en 1957, pour servir à la maturation du f..
Developmental regulation of apical endocytosis controls epithelial patterning in vertebrate tubular organs
© 2015 Macmillan Publishers Limited. Epithelial organs develop through tightly coordinated events of cell proliferation and differentiation in which endocytosis plays a major role. Despite recent advances, how endocytosis regulates the development of vertebrate organs is still unknown. Here we describe a mechanism that facilitates the apical availability of endosomal SNARE receptors for epithelial morphogenesis through the developmental upregulation of plasmolipin (pllp) in a highly endocytic segment of the zebrafish posterior midgut. The protein PLLP (Pllp in fish) recruits the clathrin adaptor EpsinR to sort the SNARE machinery of the endolysosomal pathway into the subapical compartment, which is a switch for polarized endocytosis. Furthermore, PLLP expression induces apical Crumbs internalization and the activation of the Notch signalling pathway, both crucial steps in the acquisition of cell polarity and differentiation of epithelial cells. We thus postulate that differential apical endosomal SNARE sorting is a mechanism that regulates epithelial patterning.MINECO (BFU2011-22622) and CONSOLIDER (CSD2009-00016); Fundación Obra Social `La Caixa' PhD fellowship. G.A. was supported by the Amarouto Program for senior researchers from the Comunidad Autónoma de Madrid.Peer Reviewe
El Bosque, grotte
Le siteLa grotte se trouve dans le bassin du Cares-Deva, marqué par le relief montagneux du massif central des Picos de Europa. Le long de cette vallée s’échelonnent onze autres grottes ornées : La Loja, Subores, Llonín, Coímbre, Traúno, Los Canes, Peña del Alba, Falo, Berodia, Soberaos et Covaciella (Rasilla Vives 2014).Dans la grotte d’El Bosque, aucune intervention archéologique n’a eu lieu jusqu’à présent, de sorte que nous ignorons tout d’une éventuelle occupation préhistorique. Les man..
Cerebral changes and disrupted gray-matter cortical networks in asymptomatic older adults at risk for Alzheimer's disease
The diagnostic value of cerebrospinal fluid (CSF) biomarkers is well established in Alzheimer's disease, but our current knowledge about how abnormal CSF levels affect cerebral integrity, at local and network levels, is incomplete in asymptomatic older adults. Here, we have collected CSF samples and performed structural magnetic resonance imaging scans in cognitively normal elderly as part of a cross-sectional multicenter study (SIGNAL project). To identify group differences in cortical thickness, white matter volume, and properties of structural networks, participants were split into controls (N = 20), positive amyloid-? (A?1?42 +) (N = 19), and positive phosphorylated tau (N = 18). The A?1?42 + group exhibited thickening of middle temporal regions, while positive phosphorylated tau individuals showed thinning in the superior parietal and orbitofrontal cortices. Subjects with abnormal CSF biomarkers further showed regional white matter atrophy and more segregated cortical networks, the A?1?42 + group showing heightened isolation of cingulate and temporal cortices. Collectively, these findings highlight the relevance of combining structural brain imaging and connectomics for in vivo tracking of Alzheimer's disease lesions in asymptomatic stages.This work was supported by research grants from the Spanish Ministry of Economy and
Competitiveness (SAF2011-25463 to J.L.C., PSI2014-55747-R to M.A.), the Carlos III
Institute of Health, Spain (PI11/02425 and PI14/01126 to J.F.; PI11/3035 and
PI14/1561 to A.L.; PI08/0139, PI12/02288 and PI16/01652 to P.S.J.), jointly funded by
Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, “Una manera de
hacer Europa”, the Joint Programming in Neurodegenerative Disease Research
(DEMTEST to P.S.J.), “Marató TV3” (project 20141210 to J.F. and 20142610 to A.L.),
the Regional Ministry of Innovation, Science and Enterprise, Junta de Andalucia (P12-
CTS-2327 to J.C.L.), and the CIBERNED program (Signal project)
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