Kloprogge, J T; Frost, R L
The Raman spectra at 300 and 77 K of beryl, columbite-tantalite and topaz single crystals from pegmatites in the Iveland-Evje area are described in detail. The beryl is shown to contain mainly water type I and less of type II in its channels, while CO2 is only a very minor channel constituent. Cooling to 77 K results in minor shifts towards higher wavenumbers for most bands. The Si-O vibrations at 1009 and 1066 cm(-1) show a doubling to four bands at 1015, 1072, 1087 and 1149 cm(-1) due to structural rearrangements in the hexameric rings forming the channels in the beryl crystal structure. In addition a new band becomes visible around 1155 cm(-1). The tantalite could not be analysed in detail due to strong fluorescence. The Raman spectrum of the yellow topaz from Solås is comparable to that of the colourless topaz from Topaz Mountain, Thomas Range, Utah. Upon cooling to 77 K, two OH-stretching bands become visible around 3644 and 3655 cm(-1), which were not observed at room temperature. PMID:10794464
Pūraitė, Irma; Rosef, Olav; Paulauskas, Algimantas; Radzijevskaja, Jana
Anaplasma phagocytophilum is a tick-borne bacterium that infects a wide range of animal species. The aim of our study was to investigate the prevalence of A. phagocytophilum in Norwegian moose Alces alces and to characterize the bacteria by sequencing of partial msp4 and 16S rRNA genes. Hunters collected spleen samples from 99 moose of different ages during 2013 and 2014 in two areas: Aust-Agder County (n = 70) where Ixodes ricinus ticks are abundant and Oppland County (n = 29) where ticks were either absent, or abundance very low. A. phagocytophilum was detected only in moose from the I. ricinus - abundant area. The overall prevalence of infection according to 16S rRNA and msp4 gene-based PCR was 41.4% and 31.4% respectively. Sequence analysis of the partial 16S rRNA and msp4 gene revealed two and eight different sequence types respectively. Four of eight msp4 sequence types determined in this study were unique, while others were identical to sequences derived from other ruminants and ticks. The present study indicates that moose could be a potential wildlife reservoir of A. phagocytophilum in Norway. PMID:26428857
Schmitt, A. K.; Zack, T.
In-situ geochronology of rutile can be applied to a large range of geological problems, from exhumation of lower crust to sedimentary provenance. Recent attempts to improve SIMS U-Pb rutile dating were stifled by crystal orientation dependent instrumental fractionation between Pb and U, leading to considerable uncertainty in the calibration , . Here, we demonstrate that injection of oxygen into the sputtered target region (O2 flooding) significantly reduces variation in the depth sputter rate for rutile. O2 flooding also correlates with increased homogeneity of the UO2+/U+ vs. Pb/U relative sensitivity calibration, resulting in higher precision for U-Pb ages. We also successfully tested an O2+ beam for rutile analysis. Natural and synthetic rutiles were found to efficiently dissipate local charges from positive ion bombardment, whereas charging largely prohibits the use of an O2+ primary beam for insulating silicates and phosphates that are common targets for in-situ geochronology. The advantage of the O2+ beam for rutile analysis is an ~10-times more intense beam current at a lateral resolution equivalent to conventionally used O- or O2- beams. The intense O2+ beam is also efficient in removing surficial Pb contamination. This leads to highly radiogenic Pb yields and combined with a 208Pb-based correction minimizes bias in the common Pb correction resulting from unresolved interferences on the conventionally used 204Pb. We compared three well-characterized rutiles where high-precision U-Pb ages are available: R10b (Gjerstad, Norway; 1090 Ma), R19 (Blumberg, Australia; 489.5 Ma), and JIMP-1B (Windmill Hills, Australia; 2625 Ma). O2+ -generated SIMS U-Pb and Pb-Pb age averages are accurate within <1% for Paleozoic to Archean rutile, the best accuracy reached so far for any in-situ rutile dating study. This underscores the potential of SIMS U-Th-Pb rutile geochronology at a precision and accuracy commensurate to zircon over a wide range of ages. Other potential