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11. Goldhillite, Cu5Zn(AsO4)2(OH)6⋅H2O, a new mineral species, and redefinition of philipsburgite, Cu5Zn[(AsO4)(PO4)](OH)6⋅H2O, as an As–P ordered species

Author

Ismagilova, Rezeda M., primary, Rieck, Branko, additional, Kampf, Anthony R., additional, Giester, Gerald, additional, Zhitova, Elena S., additional, Lengauer, Christian L., additional, Krivovichev, Sergey V., additional, Zolotarev, Andrey A., additional, Ciesielczuk, Justyna, additional, Mikhailova, Julia A., additional, Belakovsky, Dmitry I., additional, Bocharov, Vladimir N., additional, Shilovskikh, Vladimir V., additional, Vlasenko, Natalia S., additional, Nash, Barbara P., additional, and Adams, Paul M., additional

Published
2022
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20. A Computer-Interfaced Drop Counter as an Inexpensive Fraction Collector for Column Chromatography

Author

Nash, Barbara T.

Abstract

A computer-interfaced drop counter is described that serves as an inexpensive alternative to a fraction collector for column chromatography experiments. Undergraduate biochemistry laboratories frequently do not have the budget to purchase fraction collectors. Protocols that call for the manual measurement of fraction volumes as well as the manual application of buffer to the column do not provide students with the skills required to function in a professional setting. In this experiment, students use a column outfitted with Luer fittings to set up an automatic buffer-feeding system and also monitor fraction collection using a drop counter. Students have the opportunity to learn troubleshooting techniques for both methods. To illustrate this system, a sample of typical student data from an experiment in which the molecular weight of myoglobin is determined by gel filtration chromatography is shown. The system described can be used for any column chromatography experiment, including preparative gel filtration chromatography, ion exchange chromatography, and affinity chromatography. (Contains 3 figures and 2 notes.)

Published
2008

21. Determination of the Subunit Molecular Mass and Composition of Alcohol Dehydrogenase by SDS-PAGE

Author

Nash, Barbara T.

Abstract

SDS-PAGE is a simple, rapid technique that has many uses in biochemistry and is readily adaptable to the undergraduate laboratory. It is, however, a technique prone to several types of procedural pitfalls. This article describes the use of SDS-PAGE to determine the subunit molecular mass and composition of yeast alcohol dehydrogenase employing state-of-the-art methods that produce accurate results. Students apply precise amounts of protein to the gel to determine the optimal amount required for accurate measurements. Precision Plus Protein standards are used to produce a standard curve. Students calculate the true subunit molecular mass of the protein using information from the ExPASy protein knowledgebase. They use published data from gel filtration chromatography to determine the molecular mass of the native protein and use this information and their experimental data to determine the subunit stoichiometry of the protein. (Contains 1 table and 3 figures.)

Published
2007

23. Goldhillite, Cu5Zn(AsO4)2(OH)6⋅H2O, a new mineral species, and redefinition of philipsburgite, Cu5Zn[(AsO4)(PO4)](OH)6⋅H2O, as an As–P ordered species

Author

Ismagilova, Rezeda M., Rieck, Branko, Kampf, Anthony R., Giester, Gerald, Zhitova, Elena S., Lengauer, Christian L., Krivovichev, Sergey V., Zolotarev, Andrey A., Ciesielczuk, Justyna, Mikhailova, Julia A., Belakovsky, Dmitry I., Bocharov, Vladimir N., Shilovskikh, Vladimir V., Vlasenko, Natalia S., Nash, Barbara P., and Adams, Paul M.

Published
2022
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26. Niasite and johanngeorgenstadtite, Ni2+4.5(AsO4)3 dimorphs from Johanngeorgenstadt, Germany

Author

Kampf, Anthony R., Nash, Barbara P., Plášil, Jakub, Smith, Jason B., and Feinglos, Mark N.

Abstract

Niasite (IMA2019-105) and johanngeorgenstadtite (IMA2019-122) are Ni4.52+(AsO4)3 dimorphs from Johanngeorgenstadt, Saxony, Germany. The two new minerals occur in association with one another and with aerugite, bunsenite, quartz, rooseveltite and xanthiosite. This mineral assemblage is apparently secondary in origin and most likely formed from the breakdown of primary nickeline under dry (low relative humidity) and oxidizing (high oxygen fugacity) conditions. Both minerals are found in sugary aggregates of irregular, rounded grains or short prisms. Niasite properties are as follows: colour violet-red to red-orange; streak pale pink; transparent; resinous to subadamantine lustre; brittle tenacity; no cleavage; conchoidal fracture; Mohs hardness ∼4; densitycalc 5.222 g cm−3; optically uniaxial (–), ω 1.925(5) and ε 1.855(5) (white light), pleochroism O beige, E deep pink (OY>Z). Raman spectra of both minerals are dominated by the stretching vibrations of AsO4 tetrahedra and confirm that both minerals are anhydrous. Electron microprobe analyses give the empirical formulas (Ni3.692+Co0.662+Fe0.032+Al0.02Na0.02Cu0.012+)Σ4.43As3.03O12 and (Ni3.562+Co0.752+Cu0.132+)Σ4.44As3.02O12 for niasite and johanngeorgenstadtite, respectively. Niasite is tetragonal, I4¯2d, with a=6.8046(8), c=18.6190(13) Å, V=862.1(2) Å3 and Z=4. Johanngeorgenstadtite is monoclinic, C2∕c, with a=11.933(3), b=12.753(3), c=6.6956(17) Å, β=113.302(8)∘, V=935.9(4) Å3 and Z=4. The structure of niasite (R1=0.0226 for 471 Io>2σI reflections) is the same as that of jeffbenite, as well as those of several garnet-like synthetic phases. Johanngeorgenstadtite (R1=0.0375 for 355 Io>2σI reflections) has an unprotonated alluaudite structure.

Published
2020

27. Davidbrownite-(NH₄), (NH₄,K)₅(V⁴⁺O)₂(C₂O₄)[PO_(2.75)(OH)_(1.25)]₄·3H₂O, a new phosphate–oxalate mineral from the Rowley mine, Arizona, USA

Author

Kampf, Anthony R., Cooper, Mark A., Rossman, George R., Nash, Barbara P., Hawthorne, Frank. C., and Marty, Joe

Abstract

Davidbrownite-(NH₄), (NH₄,K)₅ (V⁴⁺O)₂(C₂O₄)[PO_(2.75)(OH)_(1.25)]₄·3H₂O, is a new mineral species from the Rowley mine, Maricopa County, Arizona, USA. It occurs in an unusual bat-guano-related, post-mining assemblage of phases that include a variety of vanadates, phosphates, oxalates and chlorides, some containing NH⁴⁺. Other secondary minerals found in association with davidbrownite-(NH₄) are antipinite, fluorite, mimetite, mottramite, quartz, rowleyite, salammoniac, struvite, vanadinite, willemite and wulfenite. Crystals of davidbrownite-(NH4) are light green–blue needles or narrow blades up to ~0.2 mm long. The streak is white, the lustre is vitreous, Mohs hardness is ca. 2, tenacity is brittle and fracture is splintery. There are two good cleavages in the [010] zone, probably {100} and {001}. The measured density is 2.12(2) g cm⁻³. Davidbrownite-(NH₄) is optically biaxial (+) with α = 1.540(2), β = 1.550(5) and γ = 1.582(2) (white light); 2V = 58.5(5)°; moderate r > v dispersion; and orientation Z = b and Y ≈ a. Pleochroism: X = pale blue, Y = nearly colourless, Z = light blue; and Y < X < Z. Electron microprobe analysis gave the empirical formula [(NH₄)_(3.11)K_(1.73)Na_(0.09)]_(Σ4.93)[(V⁴⁺_(1.92)Mg_(0.01)Al_(0.02))_(Σ1.95)O₂](C₂O₄) [(P_(3.94)As_(0.12))_(Σ4.06)O_(10.94)(OH)_(5.06)]·3H₂O, with the C and H content provided by the crystal structure. Raman and infrared spectroscopy confirmed the presence of NH₄ and C₂O₄. Davidbrownite-(NH₄) is monoclinic, P2₁/c, with a = 10.356(6), b = 8.923(5), c = 13.486(7) Å, β = 92.618(9)°, V = 1244.9(12) ų and Z = 2. The crystal structure of davidbrownite-(NH₄) (R₁ = 0.0524 for 2062 I_o > 2σI reflections) consists of a chain structural unit with the formula {(V⁴⁺O)₂(C₂O₄)[PO_(2.75)(OH)_(1.25)]₄}⁵⁻, and a disordered interstitial complex containing five large monovalent cations (NH⁴⁺ and K⁺) and three H₂O groups pfu. Strong hydrogen bonds form links within and between the chains.

Published
2019

30. Explosive silicic volcanism of the Yellowstone hotspot: the ash fall tuff record

Author

Perkins, Michael E. and Nash, Barbara P.

Subjects
Yellowstone National Park -- Natural history, Yellowstone National Park -- Environmental aspects, Magmatism -- Research, Volcanic ash, tuff, etc. -- Composition, Volcanic ash, tuff, etc. -- Structure, Volcanism -- Research, Earth sciences
Abstract

Unaltered silicic ash fall tuffs are abundant in Neogene sedimentary basins of the western U.S. and constitute an important record of explosive silicic volcanism in this region. In particular, ash fall tuffs from silicic volcanic centers along the Yellowstone hotspot track are common in these basins and provide a detailed record of explosive volcanism along the hotspot track. The available hotspot ash fall tuff record commences at ca. 16 Ma, shortly after the initiation of hotspot silicic volcanism at ca. 16.5 Ma, and continues through the most recent explosive eruptions in the late Pleistocene. Post-16 Ma hotspot silicic volcanism has been dominated by eruption of metaluminous ash flow tuffs and rhyolites, and ash fall tuffs produced by these eruptions dominate the Yellowstone hotspot ash fall tuff record. Evaluation of a well-dated composite sequence of 142 of these tuffs reveals 0systematic variation in magma composition, magma temperature, eruption frequency, and, possibly, volumetric discharge as the hotspot migrated eastward from the western edge of the North America craton to its current location in the Yellowstone Plateau. On the basis of these variations, three primary stages of metaluminous rhyolite magmatism (M stages) are recognized: M1 (16.0-15.2 Ma), M2 (15.2-7.5 Ma), and M3 (7.5-0 Ma). Each of these stages is marked by distinctive magma compositions, eruption frequencies, and magma temperature ranges and trends, with an overall decline in average eruption frequency and magma temperature from stage to stage. The partitioning of explosive hotspot volcanism into stages likely reflects variation in the style and intensity of the interaction between the mantle anomaly powering the hotspot magmatic systems and a spatially and temporally heterogeneous lithosphere along the hotspot track. Although the ash fall tuff record does not provide definitive constraints on the nature of these variable interactions, correlations between changes in eruption frequency, ash fall tuff discharge, and magma temperature point to variable input of mantle basalt into hotspot crustal magmatic systems as a first order control on intensity of explosive volcanism. As future studies reveal more about the processes controlling the variations in hotspot silicic volcanism, a fuller understanding of both the nature of silicic magmatism and the nature of the Yellowstone hotspot should emerge. Keywords: ash fall tuff, composition, eruption frequency, explosive volcanism, volumetric discharge, Yellowstone hotspot.

Published
2002

39. Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia

Author

Ossendorf, Goetz, Groos, Alexander R., Bromm, Tobias, Tekelemariam, Minassie Girma, Glaser, Bruno, Lesur, Josephine, Schmidt, Joachim, Akcar, Naki, Bekele, Tamrat, Beldados, Alemseged, Demissew, Sebsebe, Kahsay, Trhas Hadush, Nash, Barbara P., Nauss, Thomas, Negash, Agazi, Nemomissa, Sileshi, Veit, Heinz, Vogelsang, Ralf, Woldu, Zerihun, Zech, Wolfgang, Opgenoorth, Lars, Miehe, Georg, Ossendorf, Goetz, Groos, Alexander R., Bromm, Tobias, Tekelemariam, Minassie Girma, Glaser, Bruno, Lesur, Josephine, Schmidt, Joachim, Akcar, Naki, Bekele, Tamrat, Beldados, Alemseged, Demissew, Sebsebe, Kahsay, Trhas Hadush, Nash, Barbara P., Nauss, Thomas, Negash, Agazi, Nemomissa, Sileshi, Veit, Heinz, Vogelsang, Ralf, Woldu, Zerihun, Zech, Wolfgang, Opgenoorth, Lars, and Miehe, Georg

Abstract

Studies of early human settlement in alpine environments provide insights into human physiological, genetic, and cultural adaptation potentials. Although Late and even Middle Pleistocene human presence has been recently documented on the Tibetan Plateau, little is known regarding the nature and context of early persistent human settlement in high elevations. Here, we report the earliest evidence of a prehistoric high-altitude residential site. Located in Africa's largest alpine ecosystem, the repeated occupation of Fincha Habera rock shelter is dated to 47 to 31 thousand years ago. The available resources in cold and glaciated environments included the exploitation of an endemic rodent as a key food source, and this played a pivotal role in facilitating the occupation of this site by Late Pleistocene hunter-gatherers.

Published
2019

45. Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia

Author

Ossendorf, Götz, primary, Groos, Alexander R., additional, Bromm, Tobias, additional, Tekelemariam, Minassie Girma, additional, Glaser, Bruno, additional, Lesur, Joséphine, additional, Schmidt, Joachim, additional, Akçar, Naki, additional, Bekele, Tamrat, additional, Beldados, Alemseged, additional, Demissew, Sebsebe, additional, Kahsay, Trhas Hadush, additional, Nash, Barbara P., additional, Nauss, Thomas, additional, Negash, Agazi, additional, Nemomissa, Sileshi, additional, Veit, Heinz, additional, Vogelsang, Ralf, additional, Woldu, Zerihun, additional, Zech, Wolfgang, additional, Opgenoorth, Lars, additional, and Miehe, Georg, additional

Published
2019
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