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1.
Geobiology ; 14(4): 404-16, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27001345

RESUMEN

Benthic foraminifera are single-celled eukaryotes that make a protective organic, agglutinated or calcareous test. Some agglutinated, single-chambered taxa, including Psammophaga Arnold, 1982, retain mineral particles in their cytoplasm, but the selective mechanism of accumulation is not clear. Here, we report the ability of a foraminiferal species to select and accumulate zircons and other heavy minerals in their cytoplasm. In particular, the use of Scanning Electron Microscope coupled with an Energy Dispersive X-ray microanalysis system (SEM-EDS) enabled a representative overview of the mineral diversity and showed that the analysed Psammophaga zirconia sp. nov. individuals contained dominantly crystals of zircon (51%), titanium oxides (27%), and ilmenite (11%) along with minor magnetite and other minerals. The studied specimens occur in the shallow central Adriatic Sea where the sediment has a content of zircon below 1% and of other heavy minerals below 4%. For that reason we hypothesize that: (i) P. zirconia may be able to chemically select minerals, specifically zircon and rutile; (ii) the chemical mechanism allowing the selection is based on electrostatic interaction, and it could work also for agglutinated foraminifera (whether for ingestion, like Xenophyophores, or incorporation in the test as in many other described taxa). In particular, this aptitude for high preferential uptake and differential ingestion or retention of zircon is reported here for the first time, together with the selection of other heavy minerals already described in members of the genus Psammophaga. They are generally counted among early foraminifera, constructing a morphologically simple test with a single chamber. Our molecular phylogenetic study confirms that P. zirconia is a new species, genetically distinctive from other Psammophaga, and occurs in the Adriatic as well as in the Black Sea.


Asunto(s)
Foraminíferos/química , Foraminíferos/clasificación , Metales Pesados/análisis , Circonio/análisis , Análisis por Conglomerados , Citoplasma/química , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Foraminíferos/citología , Genes de ARNr , Mar Mediterráneo , Microscopía Electrónica de Rastreo , Minerales/análisis , Filogenia , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Espectrometría por Rayos X
2.
Med Sci Law ; 56(2): 107-15, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26130751

RESUMEN

During the Middle Ages and Renaissance, embalming the cadaver of the elite was common practice, being a highly technical treatment mixing vegetal and mineral substances. To assess the exact kind of embalming reserved for the dead body (with the practical necessities of desiccation and good odour), we performed a full biomedical analysis of the mummified remains of John Plantagenet of Lancaster, first Duke of Bedford, regent of France for his nephew, the English King Henri VI (died 1435 AD). Here, we show, among other aspects, that the body was embalmed using substances whose origins were in apothecary and botany: mercury, myrtle, mint, frankincense, lime and, possibly, cinnamon and copper.


Asunto(s)
Cadáver , Personajes , Patologia Forense/historia , Patologia Forense/métodos , Historia del Siglo XV , Humanos
3.
Science ; 338(6108): 785-8, 2012 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-23065902

RESUMEN

Tissint (Morocco) is the fifth martian meteorite collected after it was witnessed falling to Earth. Our integrated mineralogical, petrological, and geochemical study shows that it is a depleted picritic shergottite similar to EETA79001A. Highly magnesian olivine and abundant glass containing martian atmosphere are present in Tissint. Refractory trace element, sulfur, and fluorine data for the matrix and glass veins in the meteorite indicate the presence of a martian surface component. Thus, the influence of in situ martian weathering can be unambiguously distinguished from terrestrial contamination in this meteorite. Martian weathering features in Tissint are compatible with the results of spacecraft observations of Mars. Tissint has a cosmic-ray exposure age of 0.7 ± 0.3 million years, consistent with those of many other shergottites, notably EETA79001, suggesting that they were ejected from Mars during the same event.


Asunto(s)
Marte , Meteoroides , Isótopos de Carbono/análisis , Compuestos de Hierro/análisis , Compuestos de Magnesio/análisis , Isótopos de Nitrógeno/análisis , Isótopos de Oxígeno/análisis , Silicatos/análisis
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