Elementu anaforikoak eskolako testuetan

[EU]Artikulu honetan, eskolan eukeraz erabiltzen diren azalpenezko testu idatziaetan agetzen diren elementu anaforikoak aztertzen ditu egileak. Natur Zientzietako hiru testuliburetako unitate didaktiko batean erabilitako azalpenak aztertu ondoren, multzo bakoitzean ikusitako ezaugarri nagusienak eta bien artean dauden zenbait ezberdintasuni buruzko hausnarketak bildu dira lan honetan

La sociedad ante los museos: públicos, usuarios y comunidades locales

Cap. 1. Públicos y museos: entre la democracia cultural y la mercantilización del patrimonio. Iñaki Arrieta Urtizberea. Cap. 2. Quelle place et quels rôles pour l’habitant dans son musée ? Hugues de Varine. Cap. 3. Museos comunitarios. Estrategias creativas para la formación de públicos en barrios patrimoniales. Mauricio Rojas Alcayaga. Cap. 4. Conociendo a todos los públicos: investigación y gestión en el Laboratorio Permanente de Público de Museos. Virginia Garde López. Cap. 5. Quand le visiteur du musée devient un acteur : la nécessaire contribution de l’évaluation. Lucie Daignault. Cap. 6. Evaluación implicativa: hacia una visión generativa y participativa en la gestión de audiencias. Mikel Asensio, Elena Asenjo, Yone Castro y Elena Pol. Cap. 7. Los estudios de visitantes en museos: conocer para gestionar. Cosmocaixa, un ejemplo de buenas prácticas. Antoni Laporte. Cap. 8. Los públicos de proximidad del Museu Blau (Museo de Ciencias Naturales de Barcelona). Lina Ubero Badia y Marta Ponseti Alonso.

From Gods to men: A historical overview of the discovery of the chemical elements

To achieve the apparently simple Periodic Table of the Elements has implied tremendous efforts over thousands of years. In this paper we present a brief history of the discovery of the chemical elements from prehistory to the present day, revealing the controversies that arose on the way and claiming the important work performed by alchemists in the advancement of knowledge. This is especially important if we consider that alchemy had a period of existence of many thousands of years, while the "Chemistry", officially established as a science in the eighteenth century, has operated as such for only a few hundred years. Even so, if we consider the progress of discovery and isolation of chemical elements throughout history, it can be observed that the number of elements identified is achieved mainly in the nineteenth and twentieth centuries, reflecting the development of instrumental techniques, that facilitated this task.

Geochemical characterization of the fire-fountain fed deposits of Las Herrerias volcano (Campo de Calatrava Volcanic Field, Ciudad Real)

The Las Herrerias volcano (Bolanos de Calatrava, Campo de Calatrava Volcanic Field) is characterized by the great amount and variety of fire-fountain fed deposits. All these deposits are compositionally similar, being constituted by magnesium-rich (MgO = 11.58-4.19%), aluminium-poor (Al2O3 = 9.64-10.99%) highly sodic (Na2O = 2.24-3.81%) melanephelinites, with high contents in rare earth-elements (10x-200x chondrite), particularly in light-rare earth elements with respect to the heavy ones [(La/Lu)(N) = 32-35]. Contrary to the equivalent melanephelinites of this volcanic field, the relatively low contents in Ni (233-286 ppm), Cr (393-520 ppm) and magnesium number (Mg* = 45-54) indicate that these rocks do not correspond with primary melts. On the other hand, the variable distribution of clinopyroxene in the magma during eruption would be responsible for the slight compositional differences observed in the studied samples. Finally, we argue that these fire fountains were developed in a continental intraplate setting.

Palaeoenvironmental analysis based on alluvial ostracod assemblages of the Cenicero section (lower Miocene, NW Ebro Basin)

In this work we perform for the first time a palaeoenvironmental and biostratigraphic analysis of the lower Miocene alluvial deposits of the Cenicero section (NW sector of the Ebro Basin; N Iberian Peninsula), based on the ostracod and micromammal assemblages. One of the main characteristics of this section is the unusual abundance on non-reworked ostracods present in the studied samples compared to other European sequences of similar age and sedimentary environment. This fact has allowed us to develop precise palaeoenvironmental reconstructions. The variations of the identified ostracod assemblages, defined by species such as Cyclocypris laevis, Ilyocypris bradyi, Ilyocypris gibba, Limnocythere sp. or Pseudocandona parallela, record the development of small, ephemeral and shallow ponds in a distal alluvial and/or floodplain environment. Towards the upper part of the section the ponds appear to be less ephemeral, being the aquatic systems more stable for ostracods development. Variations in the water temperature and salinity have been observed along the section, which are related to changes in the local pluviometric regime. On the other hand, the presence of micromammals in one of the studied samples has allowed the precise dating of this section. Thus, the presence of Armantomys daamsi dates the Cenicero section as Agenian (lower Miocene), local zone Y2 (MN2).