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Se-bearing polybasite- Tac is associated with galena, chalcopyrite, sphalerite, tetrahedrite, electrum and quartz at the Martha mine, an epithermal silver–gold deposit located adjacent to the Deseado Massif, Santa Cruz province, Argentina. Three samples, with variable chemical composition and showing the 111 unit-cell type, were studied by means of X-ray single crystal diffraction and electron microprobe. The unit-cell parameters were modeled using a multiple regression method as a function of the Ag, Sb, and Se contents. The predicted values resulted in excellent agreement with experimental unit-cell parameters. We observed that high contents of selenium in polybasite are associated with relatively low copper contents. This finding corroborates previous studies that the copper content of pearceite–polybasite group minerals can be very low if selenium is present. [ABSTRACT FROM AUTHOR]

Detailed geological mapping of 900 km2, newly defined volcanic and volcaniclastic lithofacies, multiple stratigraphic profiles, and a new zircon U/Pb eruption age (178.7 ± 1.9 Ma) describe an early Jurassic extensional-related piece-meal collapsed graben caldera in the eastern sector of Deseado Massif, at southern Patagonia. This volcano-tectonic structure, here referred to as The Deseado Caldera, collapsed at least twice controlled by two major NW-striking normal faults, during which a large acidic ignimbrite (predominantly moderate to extremely high-grade) and co-ignimbrite lag breccias were extruded through multiple NW-fissure vents. During the two post-collapse periods, alluvial fans, lagoons and laharic sedimentary environments re-worked the intra-caldera volcaniclastic deposits. Finally, numerous elongated and aligned rhyolitic lava domes and dykes were emplaced during the final magmatic resurgence stage. This caldera represents the first clear evidence of the extensional tectonic regime influence, associated with the inception of Gondwana breakup, on the eruptive mechanisms of the Jurassic Chon Aike Silicic LIP in the Deseado Massif. • A new NW Jurassic graben caldera of the Deseado Massif, directly related to the extensional regime ascribed to the inception of the Gondwana breakup. • A new detailed geological map of 900 km2 of the eastern sector of the Deseado Massif. • New U-Pb zircon age data of the Chon Aike Formation (Chon Aike Silicic LIP). [ABSTRACT FROM AUTHOR]

Aim: A descriptive study was developed in an entire Argentine rural community considering breast cancer risk factors, preventive strategies and breast cancer incidence., Patients and Methods: the study comprised of 83 women. A questionnaire of 34 items was employed; a mammogram and a breast ultrasound were performed. ANOVA and Pearson correlation were employed., Results: Mean age was 54.5 years; 69% of women were postmenopausal; 96% had children; breastfeeding was X=10 months/child; Body Mass Index (BMI) was X=27.8 kg/m(2); 13% had first-degree relatives with breast cancer; 90% of women considered mammographic screening a necessary study. One woman had presented breast cancer. Argentine screening guidelines were not followed and an inverse relationship between education level and age of first mammogram was found (p<0.05). Mammographic and ultrasound studies did not reveal potential abnormalities., Conclusion: Peculiar social and cultural characteristics may be relevant to evaluate breast cancer risk factors in Argentina., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)