Search results for "EVOLUTION"
showing 6 items of 11096 documents
La libertad incorporada como clave para la neuroeducación moral
2019
La libertad es uno de los principales atributos con los que tradicionalmente se ha caracterizado al ser humano. El objetivo de este artículo es analizar si a la luz de las investigaciones y los experimentos neurocientíficos es posible seguir caracterizando al ser humano como un ser con libertad. Para ello se alude al conocido experimento de Benjamin Libet y las conclusiones reduccionistas que influyentes autores como Patricia S. Churchland o Michael Gazzaniga extraen para la filosofía práctica. Desde una metodología hermenéutica, se denuncia el reduccionismo neurocientífico que pretende negar la libertad basándose en evidencias empíricas. Frente a dicho reduccionismo se propone un enfoque h…
Late Jurassic (Kimmeridgian–Tithonian) stable isotopes (δ18O, δ13C) and Mg/Ca ratios: New palaeoclimate data from Helmsdale, northeast Scotland
2010
Abstract The data presented here provide the first detailed stable isotope ( δ 18 O, δ 13 C) and geochemical (Mg/Ca) investigation of Kimmeridgian–Tithonian belemnites from the Helmsdale Coast, Scotland, UK. Oxygen and carbon stable isotope values from well preserved specimens range from − 2.8 to + 0.3‰ and from − 2.3 to + 2.8‰ respectively. The oxygen isotope data are consistent with palaeotemperatures of up to 24 °C in the Early Kimmeridgian cymodoce Zone and down to 11 °C in the Mid Tithonian rotunda–fittoni Zones. These estimates are strongly supported by the Mg/Ca data, which also indicate a cooling episode (and very similar palaeotemperatures, 11–22 °C) at this time. The cooling event…
A 2600-year record of past polycyclic aromatic hydrocarbons (PAHs) deposition at Holzmaar (Eifel, Germany)
2014
Polycyclic aromatic hydrocarbons (PAHs) are a proxy for climate- and human-related historical fire activity which has rarely been used beyond 1800 AD. We explored the concentration and composition patterns of PAHs together with other proxies (charcoal, C, N, S, δ13C, δ15N, and δ34S) in a sediment core of Holzmaar as indicators of variations in climate and anthropogenic activity over the past 2600 years. The concentrations of pyrogenic PAHs remained low (< 500 ng g− 1) from the pre-Roman Iron Age (600 BC) until the first significant increases to ca. 1000–1800 ng g− 1 between 1700 and 1750 AD related to regional iron production. The highest increases in pyrogenic PAH concentrations occurred w…
Unraveling environmental histories from skeletal diaries — Advances in sclerochronology
2013
High-resolution proxy archives from aquatic settings are essential to better understand processes and mechanisms of global change. During the last decade, it has become increasingly evident that calcified tissues of bivalve mollusks and cold-water corals, in particular, can significantly increase our knowledge of seasonal to multi-decadal paleoclimate and paleoenvironmental variability in the extratropical oceans and coastal marine settings. Daily, tidal, fortnightly and annual growth patterns of periodically formed skeletal hard parts provide a means to place the proxy record in a precise temporal context. Their extreme longevity coupled with the running similarity between growth increment…
Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments
2010
The Sr uptake features in Bithynia tentaculata aragonite shells from monthly collections in Lake Arreo (northern Spain) over a two-year period are compared with those from the same species grown in culture experiments with similar waters under controlled temperature. The shell aragonite of B. tentaculata from Lake Arreo formed in isotopic equilibrium with the lake water. A comparison of the stable oxygen isotope values (δ18O) from the shells and waters allowed the selection of suitable shells for Sr uptake studies. The Sr/Ca molar ratio in B. tentaculata shells (Sr/Cashell) from the lake and from the culture experiments positively correlate with some chemical parameters like conductivity an…
Riconsiderare l’identità delle donne musulmane nell’Egitto post-rivoluzionario
2019
Questo articolo esplora alcune forme dell’identità femminile nell’Egitto post-rivoluzionario, quale si manifesta in due documenti pubblicati dopo la Rivoluzione del 2011 sui diritti delle donne musulmane. Sono il Documento di al–Azhar (2013) e la Dichiarazione di Alessandria (2014), concordi nel ribadire il valore delle donne e i diritti garantiti loro dalla shari‘a. L’uno e l’altra hanno visto il coinvolgimento delle femministe islamiche. Si descrivono anche le possibilità di collaborazione tra al-Azhar e le femministe islamiche, per fondare una conoscenza religiosa-femminista autoctona e sensibile al genere. Tale collaborazione è utile per l’affermazione di un’identità femminile rispettos…