A Review of Conceptual Change Research in Science Education

This article describes research done on conceptual change as published in four of the better-known science education journals during a 20-year period, from 1981 to 2001.The present review was focused at identifying three characteristics of that research: a)temporal distribution, b) research topics, and c) methodology: experimental designs and validity. The results show that much research work was carried out, although essential elements of Conceptual Change remained unclear. With respect to the meth-odology, we have evidenced scarce replication of previous studies, and an important number of studies that fall short of desirable validity level

Transparency Policies in European Public Broadcasters: Sustainability, Digitalisation and Fact-Checking

Over the last few years, European public broadcasters have promoted the concept of public service media as one of their main values. To this end, transparency policies have been implemented as a mechanism of corporate projection by strengthening their role as an essential service. The objective of this article is to ascertain the existence of this type of policies among European public broadcasters. To this end, a nominal group was made with 24 experts who were surveyed, thus generating new indicators of transparency and accountability strategies around sustainability and digitalization. The contents of the websites of RTVE (Spain), RTP (Portugal), France TV (France), RAI (Italy), BBC (UK), RTÉ (Ireland), ZDF (Germany), VRT (Belgium), and SVT (Sweden) were also analyzed, paying attention to such indicators and strategies. The main results include the identification of differences on the basis of the ideal models described by Hallin and Mancini; a commitment to credibility (fact-checking) to the detriment of diversity of opinions; and a connection between the political system and the media system, which, preliminarily, determines the level of transparency of these public entitiesThe results of this research are part of the work of the “Equipo de Investigaciones Políticas” (USC). It is also part of the project “Nuevos valores, gobernanza, financiación y servicios audiovisuales públicos para la sociedad de Internet: contrastes europeos y españoles” (2019–2021) financed by the Spanish Ministry of Innovation and Universities (RTI2018-096065-B-I00)S

SERS study of different species of p-aminothiophenol adsorbed on silver nanoparticles

In the present work we have focused the discussion on the experimental and theoretical SERS spectra of the organic compound pATP recorded on silver colloids. The huge SERS of pATP on metal substrates is significantly different from its ordinary Raman spectra due to the formation of a new specie namely p,p’ –dimercaptoazobenzene (DMAB). The features of the SERS spectra of pATP are strongly dependent on many factors as i.e. the laser power density or the laser wavelength but there are still important aspects to understand as, for example, the effect of the concentration that has already been studied before by our group. In this case we have analyzed the effect of the concentration at different wavelengths on the SERS spectra of pATP on silver nanoparticles.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Voltage selection of physisorbed or chemisorbed 4-cyanobenzoate on a nanostructured silver electrode and the dual electronic structure of charged metal-molecule hybrids.

Applied electric potentials tune SERS wavenumbers due to vibrational Stark effect, but some modes of 4CNB- show two differentiated regions, being redshifted at more negative potentials than the potential of zero charge of the electrode but remain unshifted at positive potentials. DFT calculations have been carried out for a model where 4CNB- is linked through the carboxylate [Agnq-OOC(4CNB-)]q-1 or the nitrile [Agnq-NC(4CNB-)]q-1 to stick-like silver clusters [Agn]q with different densities of charge (qeff =q/n). The comparison between calculated and experimental wavenumber shifts points out that 4CNB- is always adsorbed through the carboxylate. The dual behaviour of the wavenumbers is due to the existence of two types of electronic structure of the metal-molecule hybrid. Physisorbed (P-hybrid, repulsive) or chemisorbed (C-hybrid, attractive) surface complexes are selected by the sign of the surface excess of charge of the electrode. The electronic structure of weakly bonded P-hybrid is very sensitive to the voltage and their wavenumbers are continuously shifted, while the wavenumbers of the strong C-hybrid remain almost unshifted. This result proves the dual nature of the electronic structure of molecules bonded to charged metal electrodes or nanoparticles which can be responsible of the qualitative changes observed in electrochemical or molecular electronics experiments.Junta de Andalucía/FEDER (UMA18-FEDERJA-049 and P18-RT-4592

Differentiated adsorption of thiobenzoic acid and thiobenzamide on silver nanoparticles determined by SERS spectroscopy.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/15140?template=romeo (Submitted version)Surface-enhanced Raman scattering of thiobenzoic acid and thiobenzamide have been recorded on three different silver colloids in order to find the chemical species responsible for the spectra and to detect differences in the adsorption with respect to their oxygen counterparts, benzoic acid and benzamide, respectively. Very significant and unexpected shifts of opposite sign between the Raman and SERS wavenumbers have been detected. By comparing the experimental and DFT calculated wavenumbers, it can be concluded that the acid is bonded to the metal as thiobenzoate through the sulfur atom with unidentate coordination. SERS spectra of thiobenzamide can be explained by assuming that it is adsorbed as azanion, like in the case of benzamide, linking to the metal through the sulfur and nitrogen atoms of the ionized thiocarboxamide group. In order to support these conclusions, B3LYP/LanL2DZ force field calculations for different complexes of silver cations with the thiobenzoate anion, the neutral thiobenzamide as well as its azanion have been carried out. Additionally, the 8a;nring mode is the most enhanced band in the SERS of both adsorbates pointing to the participation of a metal-to-molecule resonant charge transfer mechanism.Spanish MINECO/FEDER (CTQ2015-65816-R) Junta de Andalucía/FEDER (UMA18-FEDERJA-049 and P18-RT-4592) Ramón Areces Foundatio

Comentarios al Borrador de Ley de Patrimonio Cultural de Uruguay

[ES] La reunión tuvo el objetivo de poner en común comentarios y observaciones al borrador del Proyecto de Ley de Patrimonio Cultural de Uruguay. Aprovechando la estancia de J. López Mazz y enmarcado en la cooperación entre el LaPa (CSIC) y la FHCE (UdelaR) y en los distintos trabajos que vienen realizando ambas instituciones en forma conjunta. La dinámica de la reunión se planteó a partir de los documentos con comentarios aportados por cada uno de los participantes y abriendo la discusión en torno a tres temas centrales: (1) objeto y cometidos de una ley de PC, (2) estructura de la ley, y (3) comentarios al articulado. Durante la reunión se pusieron en común todos los comentarios y se acordó elaborar un documento conjunto que los sintetizara. El documento que sigue se organiza en tres partes: (1) Comentarios y reflexiones generales torno al sentido y cometido de una ley de PC actual. (2) Comentarios generales acerca del borrador discutido y en torno a la estructura y objeto de la ley de PC uruguayo. (3) Comentarios individuales a cada uno de los artículos recogidos en el borrador

Emociones y engagement en los mensajes digitales de los candidatos a las elecciones generales de 2019

In recent years, social networks have become an important communication platform through which candidates promote the political engagement of their constituents.One of the variables that could influence this ability to generate engagement through social networks is the use of messages with a significant emotional charge, both positive and negative. Our research aims to delve into the analysis of this relationshipbetween political engagement and emotions in social networks, through the Sentiment Analysis in the tweets of the main candidates in the general elections of April and November 2019 in Spain. For this we resort to the technique of text extraction and its analysis with the Linguistic Inquiry and Word Count (LIWC) software, relating the level of presence of positive and negative emotions, with the level of engagement reached by the candidates during the electoral campaign. Our analysis helps to demonstrate the existence of a relationship between the emotional charge of the discourse on social networks and the level of engagement it generates, although this seems to be also mediated by the political agenda and the campaign strategy of the parties. We also verify that the relationship between emotional discourse and engagement towards a leader is not exclusively endogenous, but may also be due to exogenous elements due to the presence of shared digital communities.Las redes sociales se han convertido en los últimos años en una importante plataforma de comunicación a través de la que los candidatos promueven el compromiso político de sus electores. Una de las variables que podría influir en esa capacidad de generar engagementa través de las redes sociales es la utilización de mensajes con una importante carga emocional, tanto positiva como negativa. Nuestra investigación tiene como objetivo profundizar en el análisis de dicha relación entre el compromiso político y las emociones en las redes sociales, mediante el Análisis de Sentimientos en los tuits de los principales candidatos en las elecciones generales de abril y noviembre de 2019 en España. Para ello recurrimos a la técnica de extracción de textos y su análisis con el software Linguistic Inquiry and Word Count (LIWC), poniendo en relación el nivel de presencia de emociones positivas y negativas, con el nivel de compromiso alcanzado por los candidatos durante la campaña electoral. Nuestro análisis contribuye a demostrar la existencia de relación entre la carga emocional del discurso en las redes sociales y el nivel de engagement que genera, aunque este parece estar mediatizado además por la agenda política y la estrategia de campaña de los partidos. Comprobamos además que la relación entre discurso emocional y engagement hacia un líder no es exclusivamente endógena, sino que puede obedecer también a elementos exógenos debido a la presencia de comunidades digitales compartidas

Does the neuropsychiatric inventory predict progression from mild cognitive impairment to dementia? A systematic review and meta-analysis

Background Neuropsychiatric Symptoms (NPS) are common in Mild Cognitive Impairment (MCI). The Neuropsychiatric Inventory (NPI) and its shorter version, the Neuropsychiatric Inventory Questionnaire (NPI-Q), are the most common measures to assess NPS. Our objective was to determine if NPI/NPI-Q ratings predict conversion from MCI to dementia. Methods Empirical longitudinal studies published in English or Spanish, concerned with the role of NPS as a risk factor for conversion from MCI to dementia, with a diagnosis of MCI following clinical criteria, that reported NPI/NPI-Q total score in converters versus non-converters, were included. Random effects models were used, and heterogeneity was explored with stratification and a random-effects meta-regression. The overall conversion rate and the standardized mean difference (SMD) for evolution, as a function of NPI/NPI-Q scores, were calculated. Results The overall conversion rate was 35 %. Mean NPI/NPI-Q ratings were higher in converters versus in non-converters, with the overall SMD approaching significance. Heterogeneity was observed in studies of more than two years of follow-up and in a study with a mean age of more than 80 years. This heterogeneity concerned the size, not the direction of the difference. Conclusions Our results suggest that NPI/NPI-Q ratings are associated with conversion from MCI to dementiaThis work was financially supported through FEDER founds by the Spanish Directorate General of Scientific and Technical Research (Project Ref. PSI2014-55316-C3-1-R), the National Research Agency (Spanish 'Ministry of Science, Innovation and Universities) (Project Ref. PSI2017-89389-C2-1-R) and by the Galician Government (Consellería de Cultura, Educación e Ordenación Universitaria; axudas para a consolidación e estruturación de unidades de investigación competitivas do Sistema Universitario de Galicia; GI-1807-USC: Ref. ED431-2017/27).S

About the Unexpected Structure and Properties of Molecules Bonded to Metal Nanoclusters.

SERS (Surface-Enhanced Raman Scattering) is a very powerful technique to gain insight into the nature of metal-molecule hybrids on a molecular level. We show the results of combining SERS and theoretical calculations (1) to analyze the subtle electronic structure of metal-molecule (M-A) interfaces, especially to study the dependence of their structure and properties on applied electric potentials or fields. An example of this is the huge efficiency of the potential (EV) in tuning the energies (E) of metal-molecule charge transfer (CT) states. An equivalence between both quantities is expected on the basis of classical electrochemistry (G=E/EV=1 eV/V) but observed energy gains up to G=4 or 5 eV/V can be explained by combining the dependence of the CT energies (E) on the excess of charge of the metal (qeff) (see Graphical Abstract) and the capacitive enhancement located at metallic nanostructures (2). Moreover, theoretical calculations predict a dual electronic structure of the M-A surface complex in the case of charged molecules bonded to charged metals. These two types of surface states of the same hybrid system are of a very different nature and are selected by the sign of the metal charge (qeff). It is predicted that a single M-A complex can be very strongly bonded (chemisorbed) or form weak and very polarizable complexes (physisorbed) depending on the charges of both the ionic species and the surface excess of the metal which is modulated by the applied potential. These two types of complexes determine the properties of the overall system in the ground electronic state, like the behavior of the wavenumbers of the CN stretching band adsorbed on metals (3-4), as well as in excited states, like the forward and reverse metal-molecule CT states of the isonicotinate anion bonded to positive (chemisorbed, G~0 eV/V) or negative (physisorbed, high G) silver clusters (5), respectively (see Graphical Abstract).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The case of a southern European glacier disappearing under recent warming that survived Roman and Medieval warm periods

Mountain glaciers have generally experienced an accelerated retreat over the last three decades as a rapid response to current global warming. However, the response to previous warm periods in the Holocene is not well-described for glaciers of the of southern Europe mountain ranges, such as the Pyrenees. The situation during the Medieval Climate Anomaly (900-1300 CE) is particularly relevant since it is not certain whether the glaciers just experienced significant ice loss or whether they actually disappeared. We present here the first chronological study of a glacier located in the Central Pyrenees (N Spain), the Monte Perdido Glacier (MPG), carried out by different radiochronological techniques and their comparison with geochemical proxies with neighboring paleoclimate records. The result of the chronological model proves that the glacier endured during the Roman Period and the Medieval Climate Anomaly. The lack of ice from last 600 years indicates that the ice formed during the Little Ice Age has melted away. The analyses of the content of several metals of anthropogenic origin, such as Zn, Se, Cd, Hg, Pb, appear in low amounts in MPG ice, which further supports our age model in which the record from the industrial period is lost. This study confirms the exceptional warming of the last decades in the context of last two millennia. We demonstrate that we are facing an unprecedented retreat of the 55 Pyrenean glaciers which survival is compromised beyond a few decades