(Figure 2) Organic carbon content, stable isotope ratios, TEX86 index and sea surface temperature reconstruction for the early Aptian of ODP Hole 198-1207B

The Cretaceous has long been recognized as a time when greenhouse conditions were fueled by elevated atmospheric CO2 and accompanied by perturbations of the global carbon cycle described as oceanic anoxic events (OAEs). Yet, the magnitude and frequency of temperature change during this interval of warm and equable climate are poorly constrained. Here we present a high-resolution record of sea-surface temperatures (SSTs) reconstructed using the TEX86 paleothermometer for a sequence of early Aptian organic-rich sediments deposited during the first Cretaceous OAE (OAE1a) at Shatsky Rise in the tropical Pacific. SSTs range from ~30 to ~36 °C and include two prominent cooling episodes of ~4 °C. The cooler temperatures reflect significant temperature instability in the tropics likely triggered by changes in carbon cycling induced by enhanced burial of organic matter. SST instability recorded during the early Aptian in the Pacific is comparable to that reported for the late Albian-early Cenomanian in the Atlantic, suggesting that such climate perturbations may have recurred during the Cretaceous with concomitant consequences for biota and the marine environment.

Eric D. Perl, Theophany. The Neoplatonic Philosophy of Dionysius the Areopagite, State University of New York Press (SUNY series in ancient Greek philosophy), 2007. 163 p., ISBN-13: 978-0-7914-7111-1

Fil: Caram, Gabriela de los Ángeles.

La construcción político-social del βάρβαρος en el mundo helénico : los símbolos y/o signos identitarios que condujeron a la construcción del “nosotros” helénico

Resumen: El tema de este trabajo nos pone en el camino, estudio y reflexión sobre la construcción del concepto de “bárbaro” como oponente, contrario o antagonista de “heleno”. Esta construcción requirió de los autores de la época la necesidad de darle forma sustantiva al concepto de “heleno”, que no solo fue una figura retórica, sino un “signo identitario” importante. La afirmación de la identidad de los triunfadores de las Guerras Médicas los puso en la necesidad ideológica y política de reforzar el concepto de “heleno” desde el discurso, tal como lo habían hecho en su momento por las armas. Heródoto mismo nos indica que helenos y bárbaros son, en principio, diferentes, incluso representan regiones o espacios diferentes dentro de la ecúmene. La diferencia de lenguaje en el siglo V a. C, evolucionó hacia una forma de espacio. Aquellos que no hablaban griego fueron considerados atrasados, rudos, rebeldes e intelectualmente inferiores.

Image analysis from TEM and AFM micrograph, Table S1, S2, S3, Figure S1, Figure S2

We report on metal enrichment along a natural pH gradient owing to increased CO2 degassing at cold, shal- low seeps of Vulcano Island in the Mediterranean Sea, off Sicily. We assessed composition of unfiltered and filtered seawater (b100 nm) along acidic zones ranging between ambient and pH 5, and showed that most seep derived elements are present as nanoclusters which then aggregate into larger colloids while mixing with ambient seawater along a pH gradient. Size and elemental composition of such naturally occurring nanoparticles assessed by modern characterisation methods were in good agreement with the results from conventional analytical methods. We provide analytical evidence for the presence in the water column of a large fraction of seep derived ele- ments (e.g. approximately 50% of iron, over 80% of Mn, 100% of Cr, S and Zn) in the form of nano sized par- ticles (e.g. b100 nm) even at typical open ocean pHs. We launch in situ sampling protocols and sample preparation procedures for multi-method suitable to obtain accurate measurements on nanoparticles from environmental samples. Based on our results a first insight to the formation of natural nanoparticles at cold CO2 seeps is presented and the persistence of such nano-clusters in the surrounding seawater is stipulated.