Arsenosugar standards extracted from algae: Isolation, characterization and use for identification and quantification purposes

Sulfate (SO4-sug) and sulfonate (SO3-sug) arsenosugar standard solutions were obtained using preparative liquid chromatography. Several commercial algae samples were characterized (total contents and speciation) to select the most appropriate in relation to their arsenosugar contents. Water extracts from the selected sample (Fucus vesiculosus) were fractionated using a Hamilton PRP-X100 preparative column, and the presence of arsenic species in the isolated fractions was ascertained by IC-ICP-MS. Two of the fractions successfully presented only one arsenic species corresponding to sulfate and sulfonate arsenosugars at suitable concentrations. To unequivocally confirm the presence of both compounds, high-resolution mass spectrometry (ESITOF/ MS) was used and the exact mass determined with errors lower than 0.5 ppm. The standard solutions obtained were successfully used to identify and quantify SO4-sug and SO3-sug in several edible algae samples purchased in local market. Total arsenic content for analysed samples ranged from 34 to 57 mg·kg-1, concentration values found for SO3-sug ranged from 5 to 36 mg As·kg-1 and SO4-sug was only found in fucus with a concentration of 9,3 mg As·kg-1

Esbozo del pensamiento arendtiano a raíz de la banalidad del mal

El presente trabajo tiene como objetivo realizar un breve recorrido por el entramado del pensamiento arendtiano. Partiremos del análisis de Eichmann en Jerusalén para ir perfilando el distanciamiento que esta autora realiza con respecto a las explicaciones tradicionales basadas en la intencionalidad del mal. La banalidad del mal mostrará la obsolescencia de cualquier intento de comprensión fundado en las estructuras de sentido modernas, ya que responderá a un nuevo fenómeno del que hasta entonces no habíamos tenido constancia y que supondrá el inicio de nuevos modos de pensar: el totalitarismo. Se presentarán las características de este nuevo acontecimiento haciendo especial hincapié en el aislamiento que supone la ruptura del espacio común entre individuos por medio del terror y la ideología. Así mismo, expondremos la doble vía que Arendt entiende como posible antídoto a tal condición: la acción, que supondrá el arranque de un nuevo modo de entender la libertad y la individualidad, y el pensamiento y el juicio como facultades que favorecen el pensamiento del otro sin subsunción alguna a una mismidad. Todo ello, teniendo siempre presente la base ontológica del entramado arendtiano: la pluralidad

Ten Years of Airbnb Phenomenon Research: A Bibliometric Approach (2010–2019)

The interest in the Airbnb phenomenon is represented in the fast growth of publications indexed in the Web of Science (WoS) since the research inception of this topic in 2010. However, there are no studies that analyze the incidence of this phenomenon from a bibliometric approach using WoS. Therefore, this paper aims to quantify the incidence and composition of the Airbnb phenomenon through bibliometrics taken it as a data source. To achieve this aim, the WoS statistical instruments and the bibliometric tool VOSviewer are used. The results obtained, such as the number of articles and citations per year, the main categories of these articles, the nationalities of the authors, the most productive institutions, the sources and authors in terms of publications, and the H-Core of the most cited articles, are presented. Finally, concept maps are exposed, representing the relatedness of co-authorship and co-citation among authors, as well as the co-occurrence of the keywords in the articles analyzed. Satisfaction, trust, and innovation appear as the main research lines. This paper can be useful for academics and professionals, giving them a holistic overview of the topic, identifying new research areas, or as an objective manner to literary review approaches

[Don Quijote de la Mancha]

En portada: Editio nova, castigata et alargataTraducción parcial de: Don Quijote de la Mancha / Miguel de Cervantes SaavedraCopia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Portraits on paper. New contributions about the artistic relations between Federico de Madrazo and the Dukes of Montpensier

Federico de Madrazo viajó a Sevilla a finales de 1858. Hoy se confirma a través de unas cartas inéditas conservadas en el Museo del Prado, que Madrazo acudió por el encargo de los duques de Montpensier de realizar un gran retrato ecuestre, familiar, historicista y cortesano, con unas circunstancias y un planteamiento muy particulares, puesto que se pretendía que la obra de Madrazo tomase como referencia una obra de Dominique Papety, discípulo de Ingres, para la que se buscaba un pendant. El encargo fue evolucionando hasta desaparecer, pero dejó un rastro de obras artísticas de diferente carácter cuya revisión se plantea aquí, a la luz de una interesante documentación, que contribuye a la mejor comprensión de esta relación artística.Federico de Madrazo travelled to Seville at the end of 1858. Today we know trough some unpublished letters preserved in the Museo del Prado, that Madrazo was commisioned by the Dukes of Montpensier to create a large equestrian portrait. It had to be a courtly, historicist and familiar portrait, under some very particular circumstances and approaches, since it was intended that Madrazo’s work took as reference a painting of Dominique Papety, disciple of Ingres, for wich a pendant was sought. The com-mision kept evolving until it disappeared, but it left a trail of artistic works of different natures we are reviewing here, thanks to the interesting documentation that contributes to a better understanding of this artistic relationship

Three-terminal transport through a quantum dot in the Kondo regime: Conductance, dephasing, and current-current correlations

We investigate the nonequilibrium transport properties of a three-terminal quantum dot in the strongly interacting limit. At low temperatures, a Kondo resonance arises from the antiferromagnetic coupling between the localized electron in the quantum dot and the conduction electrons in source and drain leads. It is known that the local density of states is accessible through the differential conductance measured at the (weakly coupled) third lead. Here, we consider the multiterminal current-current correlations (shot noise and cross correlations measured at two different terminals). We discuss the dependence of the current correlations on a number of external parameters: bias voltage, magnetic field and magnetization of the leads. When the Kondo resonance is split by fixing the voltage bias between two leads, the shot noise shows a nontrivial dependence on the voltage applied to the third lead. We show that the cross correlations of the current are more sensitive than the conductance to the appearance of an external magnetic field. When the leads are ferromagnetic and their magnetizations point along opposite directions, we find a reduction of the cross correlations. Moreover, we report on the effect of dephasing in the Kondo state for a two-terminal geometry when the third lead plays the role of a fictitious voltage probe.Comment: 10 pages, 8 figures; title changed, presentation improved, references adde