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Brumadoite, a new copper tellurate hydrate, from Brumado, Bahia, Brazil
- D. Atencio, A. C. Roberts, P. A. Matioli, J. A. R. Stirling, K. E. Venance, W. Doherty, C. J. Stanley, R. Rowe, G. J. C. Carpenter, J. M. V. Coutinho
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- Journal:
- Mineralogical Magazine / Volume 72 / Issue 6 / December 2008
- Published online by Cambridge University Press:
- 05 July 2018, pp. 1201-1205
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Brumadoite, ideally Cu3Te6+O4(OH)4-5H2O, is a new mineral from Pedra Preta mine, Serra das Eguas. Brumado, Bahia, Brazil. It occurs as microcrystalline aggregates both on and, rarely, pseudomorphous after coarse-grained magnesite, associated with mottramite and quartz. Crystals are platy, subhedral. 1—2 μm in size. Brumadoite is blue (near RHS 114B), has a pale blue streak and a vitreous lustre. It is transparent to translucent and does not fluoresce. The empirical formula is (Cu2.90Pb0.04Ca0.01)Σ2.95 (Te0.936+Si0.05)Σ0.98O3.92(OH)3.84.5.24H2O. Infrared spectra clearly show both (OH) and H2O. Microchemical spot tests using a KI solution show that brumadoite has tellurium in the 6+ state. The mineral is monoclinic, P2/m or P21. Unit-cell parameters refined from X-ray powder data are a 8.629(2) Å, b 5.805(2) Å, c 7.654(2) Å,β 0 103.17(2)°, F 373.3(2) Å3, Z= 2. The eight strongest X-ray powder-diffraction lines [d in Å,(I),(hkl)] are: 8.432,(100),(100); 3.162,(66),(2̄02); 2.385,(27),(220); 2.291,(12),(l̄22); 1.916,(11),(312); 1.666,(14),(4̄22,114); 1.452,(10),(323,040); 1.450,(10),(422,403). The name is for the type locality, Brumado, Bahia, Brazil. The new mineral species has been approved by the CNMNC (IMA 2008-028).
Carlosbarbosaite, ideally (UO2)2Nb2O6(OH)2·2H2O, a new hydrated uranyl niobate mineral with tunnels from Jaguaraçu, Minas Gerais, Brazil: description and crystal structure
- D. Atencio, A. C. Roberts, M. A. Cooper, L. A. D. Menezes Filho, J. M. V. Coutinho, J. A. R. Stirling, K. E. Venance, N. A. Ball, E. Moffatt, M. L. S. C. Chaves, P. R. G. Brandão, A. W. Romano
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- Journal:
- Mineralogical Magazine / Volume 76 / Issue 1 / February 2012
- Published online by Cambridge University Press:
- 05 July 2018, pp. 75-90
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Carlosbarbosaite, ideally (UO2)2Nb2O6(OH)2·2H2O, is a new mineral which occurs as a late cavity filling in albite in the Jaguaraçu pegmatite, Jaguaraçu municipality, Minas Gerais, Brazil. The name honours Carlos do Prado Barbosa (1917–2003). Carlosbarbosaite forms long flattened lath-like crystals with a very simple orthorhombic morphology. The crystals are elongated along [001] and flattened on (100); they are up to 120 μm long and 2–5 μm thick. The colour is cream to pale yellow, the streak yellowish white and the lustre vitreous. The mineral is transparent (as individual crystals) to translucent (massive). It is not fluorescent under either long-wave or short-wave ultraviolet radiation. Carlosbarbosaite is biaxial(+) with α = 1.760(5), β = 1.775(5), γ = 1.795(5), 2Vmeas. = 70(1)º, 2Vcalc. = 83º. The orientation is X || a, Y || b, Z || c. Pleochroism is weak, in yellowish green shades, which are most intense in the Z direction. Two samples were analysed. For sample 1, the composition is: UO3 54.52, CaO 2.07, Ce2O3 0.33, Nd2O3 0.49, Nb2O5 14.11, Ta2O5 15.25, TiO2 2.20, SiO2 2.14, Fe2O3 1.08, Al2O3 0.73, H2O (calc.) 11.49, total 104.41 wt.%; the empirical formula is (□0.68Ca0.28Nd0.02Ce0.02)Σ=1.00[U1.44□0.56O2.88(H2O)1.12](Nb0.80Ta0.52Si0.27Ti0.21Al0.11Fe0.10)Σ=2.01 O4.72(OH)3.20(H2O)2.08. For sample 2, the composition is: UO3 41.83, CaO 2.10, Ce2O3 0.31, Nd2O3 1.12, Nb2 O5 14.64, Ta2O5 16.34, TiO2 0.95, SiO2 3.55, Fe2O3 0.89, Al2O3 0.71, H2O (calc.) 14.99, total 97.43 wt.%; the empirical formula is (□0.67Ca0.27Nd0.05Ce0.01)Σ=1.00[U1.04□0.96O2.08(H2O)1.92] (Nb0.79Ta0.53Si0.42Ti0.08Al0.10Fe0.08)Σ=2.00O4.00(OH)3.96(H2O)2.04. The ideal endmember formula is (UO2)2Nb2O6(OH)2·2H2O. Calculated densities are 4.713 g cm-3 (sample 1) and 4.172 g cm-3 (sample 2). Infrared spectra show that both (OH) and H2O are present. The strongest eight X-ray powder-diffraction lines [listed as d in Å (I)(hkl)] are: 8.405(8)(110), 7.081(10)(200), 4.201(9)(220), 3.333(6)(202), 3.053(8)(022), 2.931(7)(420), 2.803(6)(222) and 2.589(5)(040,402). The crystal structure was solved using single-crystal X-ray diffraction (R = 0.037) which gave the following data: orthorhombic, Cmcm, a = 14.150(6), b = 10.395(4), c = 7.529(3) Å, V = 1107(1) Å3, Z = 4. The crystal structure contains a single U site with an appreciable deficiency in electron scattering, which is populated by U atoms and vacancies. The U site is surrounded by seven O atoms in a pentagonal bipyramidal arrangement. The Nb site is coordinated by four O atoms and two OH groups in an octahedral arrangement. The half-occupied tunnel Ca site is coordinated by four O atoms and four H2O groups. Octahedrally coordinated Nb polyhedra share edges and corners to form Nb2O6(OH)2 double chains, and edge-sharing pentagonal bipyramidal U polyhedra form UO5 chains. The Nb2O6(OH)2 and UO5 chains share edges to form an open U—Nb—φ framework with tunnels along [001] that contain Ca(H2O)4 clusters. Carlosbarbosaite is closely related to a family of synthetic U–Nb–ϕ framework tunnel structures, it differs in that is has an (OH)-bearing framework and Ca(H2O)4 tunnel occupant. The structure of carlosbarbosaite resembles that of holfertite.
Cerchiaraite-(Fe) and cerchiaraite-(Al), two new barium cyclosilicate chlorides from Italy and California, USA
- A. R. Kampf, A. C. Roberts, K. E. Venance, C. Carbone, D. Belmonte, G. E. Dunning, R. E. Walstrom
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- Journal:
- Mineralogical Magazine / Volume 77 / Issue 1 / February 2013
- Published online by Cambridge University Press:
- 05 July 2018, pp. 69-80
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The ideal formula for members of the cerchiaraite group is Ba4M4(Si4O12)O2(OH)4Cl2[Si2O3(OH)4], where M represents Mn3+, Fe3+ or Al in the octahedral site. A suffix-based naming scheme is used in which the original cerchiaraite is renamed cerchiaraite-(Mn) and two new minerals are named cerchiaraite-(Fe) and cerchiaraite-(Al). The type localities for cerchiaraite-(Fe) are the Cerchiara mine, Liguria, Italy and the Esquire No. 7 and No. 8 claims, Big Creek, Fresno County, California, USA. The type localities for cerchiaraite-(Al) are the Esquire No. 1 claim, Rush Creek, Fresno County, California, USA and the Esquire No. 7 and No. 8 claims noted above. At the Cerchiara mine, cerchiaraite-(Fe) occurs in small fractures and veinlets in a Jurassic ophiolitic sequence. It is of secondary hydrothermal origin and occurs as tan to brown thin prisms and matted fibres. Cerchiaraite(Fe) and cerchiaraite-(Al) from the Esquire No. 1, No. 7 and No. 8 claims occur in parallel-bedded quartz-sanbornite vein assemblages which formed as a result of fluid interaction along the margin of the vein. At the Esquire No. 1, No. 7 and No. 8 claims, both cerchiaraite-(Fe) and cerchiaraite-(Al) occur as subparallel aggregates of blue to bluish green irregular prisms. Both minerals are transparent with a vitreous lustre, Mohs hardness ~4½ , brittle tenacity, irregular fracture and no cleavage. The calculated density of cerchiaraite-(Fe) is 3.710 g cm-3; the measured density of cerchiaraite-(Al) is 3.69(3) g cm-3and the calculated density is 3.643 g cm-3. Cerchiaraite-(Fe) is uniaxial (+), with ω = 1.741(2) and ε = 1.768(2); it is weakly pleochroic and O is colourless and E is yellow. Cerchiaraite-(Al) is uniaxial (-), with ω = 1.695(2) and e = 1.677(2); it is strongly pleochroic and O is colourless and E is blue. Electron-microprobe analyses yielded empirical formulae ranging from (Ba3.82Na0.02Ca0.04)Σ3.88(Fe3+3.42Ti4+0.27Al3+0.25Mn3+0.04Mg0.02)Σ4.00Si5.62O15.47(OH)9.31Cl2.22 (Cerchiara mine) to Ba4.00(Al3+2.40Fe3+1.12Mg0.15Fe2+0.12Mn2+0.06)Σ3.85Si5.78O15.34(OH)8.75Cl2.91 (Esquire No. 1 claim). Cerchiaraite is tetragonal with Z = 2 and crystallizes in space group I4/mmm. The cell parameters for cerchiaraite-(Fe) are a = 14.3554(12), c = 6.0065(5) Å and V = 1237.80(5) Å3; those for cerchiaraite(Al) are a = 14.317(4), c = 6.0037(18) Å and V = 1230.6(6) Å3. In the cerchiaraite-(Fe) structure, SiO4 tetrahedra share corners forming a four-membered Si4O12 ring. The ring is corner-linked to an edgesharing chain of Fe3+ O6 octahedra running parallel to c. A Cl site alternates along c with the Si4 O12 ring. A large channel in the framework contains Ba atoms around its periphery and statistically distributed Si2 O7 silicate dimers and Cl atoms. The strong blue pleochroic colour is attributed to Fe2+ - Fe3+intervalence charge transfer along the octahedral chain.
D.07 Clinical electromyography training in Canada: The experience of neurology and physiatry residents
- MJ Berger, AG Florendo-Cumbermack, DA Gray, É Côté-Mantha, K Chapman, P Winston, S Venance
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 43 / Issue S2 / June 2016
- Published online by Cambridge University Press:
- 17 June 2016, pp. S14-S15
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Background: There are currently no national standards for clinical electromyography (EMG) training for residents in neurology and physiatry in Canada. The purpose of this study was to obtain demographic and qualitative data pertaining to EMG residency training in Canada, with the goal of facilitating discourse that could lead to national standards for EMG training. Methods: An online survey was distributed to senior neurology and physiatry residents (post-graduate years 3-5), at seven tertiary Canadian centres. The study authors, who are trainees and consultants with a broad range of EMG expertise (junior and senior resident, clinical neuromuscular fellows, senior physiatrist and neuromuscular neurologists), developed pertinent demographic and qualitative questions. Results: Thirty-eight residents completed the survey (23 neurology, 15 physiatry). There was inter-program variation in quantity of the training experience, content of the curriculum, access to expertise (including technologists) and goals for future training and practice. Similarly, differences were identified between the training experiences of neurology and physiatry residents. Conclusions: Inter-program variability in EMG training was identified. Additionally, differences were identified between neurology and physiatry resident training. This data provides evidence of training discrepancies across the country and can be used to establish national training standards for EMG in Canada.
Contributors
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- By Amelia Evoli, Ami K. Mankodi, Ana Ferreiro, Anders Oldfors, Anne K. Lampe, Anneke J. van der Kooi, Bernard Brais, Bertrand Fontaine, Bjarne Udd, Carina Wallgren-Pettersson, Caroline A. Sewry, Carsten G. Bönnemann, Cecilia Jimenez-Mallebera, Chad Heatwole, Charles A. Thornton, Corrado Angelini, David Hilton-Jones, Doreen Fialho, Duygu Selcen, Edward J. Cupler, Emma Ciafaloni, Enrico Bertini, Eric A. Shoubridge, Eric Logigian, Erin O’Ferrall, Eugenio Mercuri, Franco Taroni, Frank L. Mastaglia, Frederic Relaix, George Karpati, Giovanni Meola, Gisèle Bonne, Hannah R. Briemberg, Hanns Lochmüller, Heinz Jungbluth, Ichizo Nishino, Jenny E. Morgan, John Day, John Vissing, John T. Kissel, Kate Bushby, Leslie Morrison, Maria J. Molnar, Marianne de Visser, Marinos C. Dalakas, Mary Kay Floeter, Mariz Vainzof, Maxwell S. Damian, Michael G. Hanna, Michael Rose, Michael Sinnreich, Michael Swash, Miranda D. Grounds, Mohammed Kian Salajegheh, Nigel G. Laing, Patrick F. Chinnery, Rabi Tawil, Rénald Gilbert, Richard Orrell, Robert C. Griggs, Roberto Massa, Saiju Jacob, Shannon L. Venance, Stefano Di Donato, Stella Mitrani-Rosenbaum, Stephen Gee, Stuart Viegas, Susan C. Brown, Tahseen Mozaffar, Tanja Taivassalo, Valeria A. Sansone, Violeta Mihaylova, Yaacov Anziska, Zohar Argov
- George Karpati, McGill University, Montréal
- Edited by David Hilton-Jones, Kate Bushby, Robert C. Griggs
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- Book:
- Disorders of Voluntary Muscle
- Published online:
- 26 February 2010
- Print publication:
- 21 January 2010, pp vii-x
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