Lunar sample analysis

Results are presented from an extensive series of new high resolution scanning electron microscope studies of the very primative group of meteorites known as unequilibrated chondrites. These include quantitative analyses of micrometer sized phases and interpretation in terms of relevant phase equilibria. Several new meteorite minerals including high chromium metal, have been discovered

The crystal structure of munakataite, Pb_2Cu_2(Se^(4+)O_3)(SO_4)(OH)_4, from Otto Mountain, San Bernardino County, California, USA

Munakataite, Pb_2Cu_2(Se^(4+)O_3)(SO_4)(OH)_4, has been found in association with a variety of rare secondary Te minerals at Otto Mountain, San Bernardino County, California, USA. It is very rare and occurs as subparallel bundles of blue needles up to 1 mm long. Electron microprobe analyses provided the empirical formula Pb_(1.96)Cu_(1.60)[(Se^(4+)_(0.89)S_(0.11)_(∑1)O_3](SO_4)[(OH)_(3.34)(H_2O)_(0.66)]_(∑4). Munakataite is monoclinic, space group P2_1/m, with cell parameters a = 9.8023(26), b = 5.6751(14), c = 9.2811(25) Å , β = 102.443(6), V = 504.2(2) Å^3 and Z = 2. The crystal structure, solved by direct methods and refined to R_1 = 0.0308 for 544 F_o > 4σF reflections, consists of Jahn-Teller-distorted Cu^(2+)O_6 square bipyramids, which form chains along b by sharing trans edges across their square planes. The chains are decorated by SO_4 tetrahedra and Se^4+O_3 pyramids, which bond to apical corners of adjacent bipyramids. The chains are linked to one another via bonds to two different PbO_9 polyhedra, only one of which exhibits one-sided coordination typical of Pb^(2+) with a stereochemically active 6s^2 lone-electron-pair. Munakataite is isostructural with schmiederite and the structure is closely related to that of linarite

Membership categorization, culture and norms in action

In this article, we examine the extent to which membership categorization analysis (MCA) can inform an understanding of reasoning within the public domain where morality, policy and cultural politics are visible (Smith and Tatalovich, 2003). Through the examination of three examples, we demonstrate how specific types of category device(s) are a ubiquitous feature of accountable practice in the public domain where morality matters and public policy intersect. Furthermore, we argue that MCA provides a method for analysing the mundane mechanics associated with everyday cultural politics and democratic accountability assembled and presented within news media and broadcast settings

Alcaparrosaite, K_3Ti^(4+)Fe^(3+)(SO_4)_4O(H_2O)_2, a new hydrophobic Ti^(4+) sulfate from Alcaparrosa, Chile

Alcaparrosaite, ideally K_3Ti^(4+)Fe^(3+)(SO_4)_4O(H_2O)_2, is a new mineral from the Alcaparrosa mine, Cerritos Bayos, El Loa Province, Antofagasta, Chile (IMA2011-024). The mineral occurs on and intergrown with coquimbite, and is also associated with ferrinatrite, krausite, pertlikite, pyrite, tamarugite and voltaite. It is a relatively early phase which forms during the oxidation of pyritic masses under increasingly arid conditions. Alcaparrosaite crystallizes from hyperacidic solutions in a chemical environment that is consistent with its association with coquimbite. It occurs as pale yellow blades and tapering prisms up to 4 mm in length, flattened on {010} and elongated along [100]. The observed crystal forms are {010}, {110}, {1.13.0} and {021}. The mineral is transparent and has a white streak, vitreous lustre, Mohs hardness of about 4, brittle tenacity, conchoidal fracture and no cleavage. The measured and calculated densities are 2.80(3) and 2.807 g cm^(−3), respectively. It is optically biaxial (+) with α = 1.643(1), β = 1.655(1), γ = 1.680(1) (white light), 2V_(meas) = 70(2)° and 2V_(calc) = 70.3°. The mineral exhibits strong parallel dispersion, r 2.704 (38) (2İ23,152); 1.9283 (30) (1İ55); 1.8406 (31) (3İ53,206). In the structure of alcaparrosaite (R_1 = 2.57% for 1725 F_o > 4σF), Ti^(4+) and Fe^(3+), in roughly equal amounts, occupy the same octahedrally coordinated site. Octahedra are linked into dimers by corner sharing. The SO_4 tetrahedra link the dimers into chains parallel to [001] and link the chains into undulating sheets parallel to {010}. The sheets link via 10- and 11-coordinated K atoms in the interlayer region. The structure shares some features with that of goldichite

Assessment of discharge treatment prescribed to women admitted to hospital for hyperemesis gravidarum

Aims: Prescribing drug treatment for the management of hyperemesis gravidarum (HG), the most severe form of nausea and vomiting in pregnancy, remains controversial. Since most manufacturers do not recommend prescribing antiemetics during pregnancy, little is known regarding which treatments are most prevalent among pregnant patients. Here we report for the first time, evidence of actual treatments prescribed in English hospitals.Methods: A retrospective pregnancy cohort was constructed using anonymised electronic records in the Nottingham University Hospitals Trust system for all women who delivered between January 2010 and February 2015. For women admitted to hospital for HG, medications prescribed on discharge were described and variation by maternal characteristics was assessed. Compliance with local and national HG treatment guidelines was evaluated.Results: Of 33,567 pregnancies (among 30,439 women), the prevalence of HG was 1.7%. Among 530 HG admissions with records of discharge drugs, Cyclizine was the most frequently prescribed (almost 73% of admissions). Prochlorperazine and metoclopramide were prescribed mainly in combination with other drugs, however, ondansetron was more common than metoclopramide at discharge from first and subsequent admissions. Steroids were only prescribed following readmissions. Thiamine was most frequently prescribed following readmission while high dose of folic acid was prescribed equally after first or subsequent admissions. Prescribing showed little variation by maternal age, ethnicity, weight, socioeconomic deprivation, or comorbidities.Conclusion: Evidence that management of HG in terms of discharge medications mainly followed local and national recommendations provides reassurance within the health professional community. Wider documentation of drugs prescribed to women with HG is required to enable full assessment of whether optimal drug management is being achieved

Bobmeyerite, a new mineral from Tiger, Arizona, USA, structurally related to cerchiaraite and ashburtonite

Bobmeyerite, Pb_4(Al_(3)Cu)(Si_(4)O_12)(S_(0.5)Si_(0.5)O_4)(OH)_(7)Cl(H_(2)O)_3, is a new mineral from the Mammoth - Saint Anthony mine, Tiger, Pinal County, Arizona, USA. It occurs in an oxidation zone assemblage attributed to progressive alteration and crystallization in a closed system. Other minerals in this assemblage include atacamite, caledonite, cerussite, connellite, diaboleite, fluorite, georgerobinsonite, hematite, leadhillite, matlockite, murdochite, phosgenite, pinalite, quartz, wulfenite and yedlinite. Bobmeyerite occurs as colourless to white or cream-coloured needles, up to 300 mm in length, that taper to sharp points. The streak is white and the lustre is adamantine, dull or silky. Bobmeyerite is not fluorescent. The hardness could not be determined, the tenacity is brittle and no cleavage was observed. The calculated density is 4.381 g cm^(-3). Bobmeyerite is biaxial (-) with a ≈ b = 1.759(2), γ = 1.756(2) (white light), it is not pleochroic; the orientation is X = c; Y or Z = a or b. Electron-microprobe analyses provided the empirical formula Pb_(3.80)Ca_(0.04)Al_(3.04) Cu^(2+)_(0.96)Cr^(3+)_(0.13)Si_(4.40)S_(0.58)O_(24.43) Cl_(1.05)F_(0.52)H_(11.83). Bobmeyerite is orthorhombic (pseudotetragonal), Pnnm with unit-cell parameters a = 13.969(9), b = 14.243(10), c = 5.893(4) Å, V = 1172.5(1.4) Å 3 and Z = 2. The nine strongest lines in the X-ray powder diffraction pattern, listed as [d_(obs)(Å )(I)(hkl)], are as follows: 10.051(35)(110); 5.474(54)(011,101); 5.011(35)(220); 4.333(43)(121,211); 3.545(34)(040,400); 3.278(77)(330,231,321); 2.9656(88)(141,002,411); 2.5485(93)(051,222,501); 1.873(39)(multiple). Bobmeyerite has the same structural framework as cerchiaraite and ashburtonite. In the structure, which refined to R_1 = 0.079 for 1057 reflections with F > 4σF, SiO_4 tetrahedra share corners to form four-membered Si_(4)O_12 rings centred on the c axis. The rings are linked by chains of edge-sharing AlO_6 octahedra running parallel to [001]. The framework thereby created contains large channels, running parallel to [001]. The Cl site is centred on the c axis alternating along [001] with the Si_(4)O_12 rings. Two non-equivalent Pb atoms are positioned around the periphery of the channels. Both are elevencoordinate, bonding to the Cl atom on the c axis, to eight O atoms in the framework and to two O (H_(2)O) sites in the channel. The Pb atoms are off-centre in these coordinations, as is typical of Pb^2+ with stereo-active lone-electron pairs. A (S, Si, Cr)O_4 group is presumed to be disordered in the channel. The name honours Robert (Bob) Owen Meyer, one of the discoverers of the new mineral

Calibration commentary

Radiocarbon is by far and away the most widely used dating tool in the Late Quaternary. Hundreds of key papers rely on the method to provide absolute and relative chronological information on important topics, including the late evolution of our own species (e.g. Higham et al. 2006a) and the timing and nature of abrupt climatic changes during the last glaciation (Lowe et al. 2001). Calibration of 14C determinations is an essential part of the dating process, and the implications of calibration can lead to significant differences in the interpretation of important processes (Blockley et al. 2006). Any development that enhances the accuracy, precision, or time coverage of the calibration curves is therefore to be welcomed. Since the early 1980s, there has been periodic publication of carefully vetted data in the form of internationally recognized consensus calibration curves that have allowed 14C users to convert their raw 14C determinations into calendar ages (Klein et al. 1982; Stuiver and Reimer 1986, 1993; Stuiver et al. 1998; Reimer et al. 2004). In the beginning, the basis on which this was done was easy to understand, 14C measurements were made on tree rings and the absolute calendar age came from counting annual growth rings. Although not without its complexities, the terrestrial tree-ring approach remains the most certain method and is at the heart of calibration process in the period 0-12.4 cal kyr. However, for periods beyond the limit of the tree-ring sequences the situation was significantly more problematic, and at times, even controversial.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Camaronesite, [Fe^(3+)(H_2O)_2(PO_3OH)]_2(SO_4)•1-2H_2O, a new phosphate-sulfate from the Camarones Valley, Chile, structurally related to taranakite

Camaronesite (IMA 2012-094), [Fe^(3+)(H_2O)_2(PO_3OH)]_2(SO_4)•1-2H_2O, is a new mineral from near the village of Cuya in the Camarones Valley, Arica Province, Chile. The mineral is a low-temperature, secondary mineral occurring in a sulfate assemblage with anhydrite, botryogen, chalcanthite, copiapite, halotrichite, hexahydrite, hydroniumjarosite, pyrite, römerite, rozenite and szomolnokite. Lavender-coloured crystals up to several mm across form dense intergrowths. More rarely crystals occur as drusy aggregates of tablets up to 0.5 mm in diameter and 0.02 mm thick. Tablets are flattened on {001} and exhibit the forms {001}, {104}, {015} and {018}. The mineral is transparent with white streak and vitreous lustre. The Mohs hardness is 2½, the tenacity is brittle and the fracture is irregular, conchoidal and stepped. Camaronesite has one perfect cleavage on {001}. The measured and calculated densities are 2.43(1) and 2.383 g/cm^3, respectively. The mineral is optically uniaxial (+) with ω = 1.612(1) and ε = 1.621(1) (white light). The pleochroism is O (pale lavender) > E (colourless). Electron-microprobe analyses provided Fe_2O_331.84, P_2O_529.22, SO_315.74, H_2O 23.94 (based on O analyses), total 100.74 wt.%. The empirical formula (based on 2 P a.p.f.u.) is: Fe_(1.94)(PO_3OH)_2(S_(0.96)O_4)(H_2O)_4•1.46H_2O. The mineral is slowly soluble in concentrated HCl and extremely slowly soluble in concentrated H_2SO_4. Camaronesite is trigonal, R32, with cell parameters:a = 9.0833(5), c = 42.944(3) Å, V = 3068.5(3) Å3 and Z = 9. The eight strongest lines in the X-ray powder diffraction pattern are [d_(obs) Å (I)(hkl)]: 7.74(45)(101), 7.415(100)(012), 4.545(72)(110), 4.426(26)(018), 3.862(32)(021,202,116), 3.298(93)(027,119), 3.179(25)(208) and 2.818(25)(1•1•12,125). In the structure of camaronesite (R_1 = 2.28% for 1138 F_o > 4σF), three types of Fe octahedra are linked by corner sharing with (PO_3OH) tetrahedra to form polyhedral layers perpendicular to c with composition [Fe^(3+)(H_2O)_2(PO_3OH)]. Two such layers are joined through SO_4 tetrahedra (in two half-occupied orientations) to form thick slabs of composition [Fe^(3+)(H_2O)_2(PO_3OH)]_2(SO_4). Between the slabs are partially occupied H_2O groups. The only linkages between the slabs are hydrogen bonds. The most distinctive component in the structure consists of two Fe octahedra linked to one another by three PO_4 tetrahedra yielding an [Fe_2(PO_4)_3] unit. This unit is also the key component in the sodium super-ionic conductor (NASICON) structure and has been referred to as the lantern unit. The polyhedral layers in the structure of camaronesite are similar to those in the structure of taranakite. The Raman spectrum exhibits peaks consistent with sulfate, phosphate, water and OH groups

Zincalstibite-9R: the first nine-layer polytype with the layered double hydroxide structure-type

Zincalstibite-9R, a new polytype in the hydrotalcite supergroup is reported from the Monte Avanza mine, Italy. It occurs as pale blue curved disc-like tablets flattened on {001} intergrown to form rosettes typically less than 50 μm in diameter, with cyanophyllite and linarite in cavities in baryte. Zincalstibite-9R is uniaxial (−), with refractive indices ω = 1.647(2) and ε = 1.626(2) measured in white light. The empirical formula (based on 12 OH groups) is (Zn^(2+)_(1.09)Cu^(2+)_(0.87)Al_(0.04))_(Σ2.00)Al_(1.01) (Sb^(5+)_(0.97)Si_(0.02))Σ_(0.99)(OH)_(12), and the ideal formula is (Zn,Cu)_2Al(OH)_6[Sb(OH)_6]. Zincalstibite-9R crystallizes in space group R3İ, with ɑ = 5.340(2), c = 88.01(2) Å, V = 2173.70(15) Å^3 and Z = 9. The crystal structure was refined to R_1 = 0.0931 for 370 unique reflections [F_o > 4σ(F)] and R_1 = 0.0944 for all 381 unique reflections. It has the longest periodic layer stacking sequence for a layered double hydroxide compound reported to date