Letter from James Winthrop to William Bentley, 1799 November 25

Two folio-sized leaves containing a one-and-a-half-page handwritten letter from Winthrop to Bentley discussing James Dallaway's Constantinople, Ancient and Modern, and Greek mythology.

Shāhnāmah : manuscript, 1718-1721

Written in a professional taʻlīq script in black ink, rubricated in red, 20 lines per page in 4 gold-ruled columns. Contains 115 miniatures portraying various scenes from the poem.

O imaginário das ilhas atlânticas no universo medieval islâmico-cristão

O pensamento cultural medieval aparece-nos como herdeiro da Antiguidade Clássica, da sua filosofia, ciência, arte e mitos. Todos estes conceitos traduzem-se com facilidade para as elites intelectuais cristãs e muçulmanas, que os conservam e integram em elementos da sua própria cultura. A ideia do mar, em especial o mar dito ‘aberto’ como o Oceano Atlântico, é marcada pelo maravilhoso. Em plena Idade Média o Oceano Atlântico surge como território de Caos, envolto em mistério. O Oceano Atlântico é local das mais variadas manifestações do fantástico. Desta forma, as ilhas atlânticas, contidas neste vasto oceano, são elas próprias impregnadas de um carácter maravilhoso. Tentaremos, ao longo desta dissertação de mestrado, abordar a questão das ilhas atlânticas e das suas características a nível de imaginário. Este exercício será feito, sempre que possível, fazendo o cruzamento de fontes de origem islâmica e de origem cristã. Desta maneira, surgirá uma imagem comum em relação ao imaginário do Oceano Atlântico e, em especial, das ilhas neste contidas. O objetivo principal deste trabalho é verdadeiramente demonstrar pontos de aproximação entre relatos e mapas, de origem cristã e islâmica, ligados a ilhas fantásticas e, ao mesmo tempo, reais. Veremos que as duas categorias, do real e do imaginário, sobrepõem-se diversas vezes, sendo que não se conseguem muitas vezes distinguir a nível das fontes. Desta forma, relatos de navegações atlânticas como a de São Brandão (de origem celto-cristã) ou a dos Aventureiros de Lisboa (originária no al-Andalus,) são reveladoras das atitudes e ideias na Idade Média em relação ao Atlântico e às suas ilhas.

(Table 1) Age determination of sediment cores MD925-2002 and MD03-2690

The compilation of results obtained on three giant piston cores from the Whittard, Shamrock and Guilcher turbidite levees reveals a high-resolution stratigraphic record for the Bay of Biscay. Due to the abundance of reworked sediments in these sedimentary environments, a specific methodological approach, based on an X-ray-assisted subsampling phase associated with sedimentological, geochemical and micropalaeontological analyses, was implemented. With an accurate chronological framework, this multi-proxy investigation provides observations on the 'Fleuve Manche' palaeoriver and the British-Irish Ice Sheet (BIS) histories over the last 20,000 years. The results obtained highlight the direct influence of the decay of the BIS on the Bay of Biscay deep-sea clastic sedimentation during the last European deglacial phase. During this period, the annual BIS cycle of meltwater seems enough to generate seasonal turbidity currents associated with exceptional sedimentation rates in all the Celtic and Armorican turbidite systems. With very high sedimentation rates, the turbidite levees represent the main deep-sea clastic depositional area. Long coring combined with a very careful subsampling method can provide continuous high-resolution palaeoenvironmental signals.

Dissolved organic carbon concentrations, amino sugar concentrations and highly significantly correlating FT-ICR mass peak magnitudes obtained from solid phase extracted marine dissolved organic matter during POLARSTERN cruise ANT-XXV/1

Dissolved organic matter (DOM) was extracted with solid phase extraction (SPE) from 137 water samples from different climate zones and different depths along an Eastern Atlantic Ocean transect. The extracts were analyzed with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI). D14C analyses were performed on subsamples of the SPE-DOM. In addition, the amount of dissolved organic carbon was determined for all water and SPE-DOM samples as well as the yield of amino sugars for selected samples. Linear correlations were observed between the magnitudes of 43% of the FT-ICR mass peaks and the extract D14C values. Decreasing SPE-DOM D14C values went along with a shift in the molecular composition to higher average masses (m/z) and lower hydrogen/carbon (H/C) ratios. The correlation was used to model the SPE-DOM D14C distribution for all 137 samples. Based on single mass peaks a degradation index was developed to compare the degradation state of marine SPE-DOM samples analyzed with FT-ICR MS. A correlation between D14C, degradation index, DOC values and amino sugar yield supports that SPE-DOM analyzed with FT-ICR MS reflects trends of bulk DOM. A relative mass peak magnitude ratio was used to compare aged SPE-DOM and fresh SPE-DOM regarding single mass peaks. The magnitude ratios show a continuum of different reactivities for the single compounds. Only few of the compounds present in the FT-ICR mass spectra are expected to be highly degraded in the oldest water masses of the Pacific Ocean. All other compounds should persist partly thermohaline circulation. Prokaryotic (bacterial) production, transformation and accumulation of this very stable DOM occurs probably primarily in the upper ocean. This DOM is an important contribution to very old DOM, showing that production and degradation are dynamic processes.