Radioactive minerals - Multimedias strategies for their divulgation

Science.gov (United States)

Cabral, João; Gomes, Ana; Aldano, Ana; Fonseca, Pedro; Cabral, Tiago; Nobre, José

2014-05-01

The region corresponding to Sortelha-Penalobo - Bendada, located deep in the transition zone between the Hesperian massif and the Cova da Beira in the central part of Portugal, more specifically in the Mountainous region of the province of Beira Alta, county Sabugal. This region is characterized by great mineral wealth combined with geomorphology of recognized landscape value. Under the scientific point of view, this region is the origin of the mineral sabugalite (HAl(UO2)4(PO4)4.16H2O) that was described by the famous American mineralogist Clifford Frondel (1907-2002) in the fifties of the 20th century. Uranium minerals of Sabugal region were also associated with the radioactivity studies made by the well-known French physicist Marie Curie (1867-1934). In 2007, U. Kolitsch et al described the Bendadaite (Fe (AsO4) 2 (OH) 2 • 4H2O), which corresponds to a new mineral from the group arthurite. The mineral wealth of this region is responsible for a rich history of mining and to highlight the importance until the 1990s the extraction of uranium minerals. The main uranium minerals extracted were the tobernite (Cu (UO2) 2 (PO4) 2 • 12 H2O), the metatobernite (Cu (UO2) 2 (PO4) 2 • 8 H 2 O), the autonite (Ca (UO2) 2 (PO4 ) 2 • 12H2O-10) and sabugalite (HAL (UO2) 4 (PO4) 4 16H2O). Due to the high radioactivity of these minerals, their handling becomes infeasible for disclosure purposes. An integrated and multidisciplinary museological strategy aims to access 3D images by QR codes, using multitouch as the primary means of interaction with the user, and can handle even the virtual samples, access various magnifications and enjoy explanations supplied by a mascot, in a fun way. All this framework and geological environment becomes an asset for the scientific, educational and economic development of the region. On the other hand, it has a vital importance in the context of a strategy of forming a geological park, in the point of view of tourism, research and

Influence of Uranium on Bacterial Communities: A Comparison of Natural Uranium-Rich Soils with Controls

Science.gov (United States)

Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

2011-01-01

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil. PMID:21998695