Search results for "Hierarchical analysi"
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Distribution of Heavy Metals in Marine Sediments of Palermo Gulf (Sicily, Italy)
2008
Concentrations of Cr, Cu, Hg, Pb and Zn have been measured, by atomic absorption spectrophotometry, in the fine fraction (<63 μm) of surface sediments collected in 30 sites in the Palermo Gulf (Sicily, Italy) in order to assess the levels and the spatial distribution of these elements. Enrichment factors calculated with respect to clean areas have been considered to discriminate between levels due to background or to pollution contributions. The sampling stations, which form a grid inside these areas, are characterized by geographic proximity and by the presence of pollution sources. Ratio matching technique along with hierarchical clustering, minimum spanning tree and principal component a…
Un ecosistema malalt: la lluita contra la resistència a antibiòtics des d’una perspectiva global
2013
La produccio antropogenica d'antibiotics ha provocat una malaltia dels ecosistemes microbians de dimensio planetaria, la repercussio mes immediata de la qual per a l'home es la intractabilitat de les infeccions. La comprensio del fenomen i les possibilitats d'intervencio requereixen nous metodes conceptuals, analitics i tecnologics.