136 research outputs found

    Water in alkali feldspar: The effect of rhyolite generation on the lunar hydrogen budget

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    Recent detection of indigenous hydrogen in a diversity of lunar materials, including volcanic glass (Saal et al., 2008), melt inclusions (Hauri et al., 2011), apatite (Boyce et al., 2010; McCubbin et al., 2010), and plagioclase (Hui et al., 2013) suggests water played a role in the chemical differentiation of the Moon. Water contents measured in plagioclase feldspar, a dominant mineral in the ancient crustal lunar highlands have been used to predict that 320 ppm water initially existed in the lunar magma ocean (Hui et al., 2013) whereas measurements in apatite, found as a minor mineral in lunar rocks, representing younger potassium-enriched melt predict a bulk Moon with <100 ppm water. Here we show that water in alkali feldspar, a common mineral in potassium-enriched rocks, can have ∼20 ppm water, which implies magmatic water contents of ∼1 wt. % in chemically evolved rhyolitic magmas. The source for these wet, potassium-rich magmas probably contained ∼1000 ppm H2O. Thus, lunar granites with ages from 4.3-3.9 Ga (Meyer et al., 1996) likely crystallised from relatively wet melts that degassed upon crystallisation. Geochemical surveys by the Lunar Prospector (Jolliff et al., 2011) and Diviner Lunar Radiometer Experiment (Glotch et al., 2010; Jolliff et al., 2011) indicating the global significance of evolved igneous rocks suggest that the formation of these granites removed water from some mantle source regions, helping to explain the existence of mare basalts with <10 ppm water, but must have left regions of the interior relatively wet as seen by the water content in volcanic glass and melt inclusions. Although these early-formed evolved melts were water-rich, their petrogenesis supports the conclusion that the Moon's mantle had <100 ppm water for most of its history

    Quantitative proteogenomics of human pathogens using DIA-MS.

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    The increasing number of bacterial genomes in combination with reproducible quantitative proteome measurements provides new opportunities to explore how genetic differences modulate proteome composition and virulence. It is challenging to combine genome and proteome data as the underlying genome influences the proteome. We present a strategy to facilitate the integration of genome data from several genetically similar bacterial strains with data-independent analysis mass spectrometry (DIA-MS) for rapid interrogation of the combined data sets. The strategy relies on the construction of a composite genome combining all genetic data in a compact format, which can accommodate the fusion with quantitative peptide and protein information determined via DIA-MS. We demonstrate the method by combining data sets from whole genome sequencing, shotgun MS and DIA-MS from 34 clinical isolates of Streptococcus pyogenes. The data structure allows for fast exploration of the data showing that undetected proteins are on average more amenable to amino acid substitution than expressed proteins. We identified several significantly differentially expressed proteins between invasive and non-invasive strains. The work underlines how integration of whole genome sequencing with accurately quantified proteomes can further advance the interpretation of the relationship between genomes, proteomes and virulence

    La pandémie a besoin d'une stratégie cantonale et supracantonale : changement de perspective après deux ans de gestion du Covid-19 = Zeit für eine kantonale und überkantonale Corona-Strategie : Perspektivenwechsel nach zwei Jahren Corona-Politik

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    Das Ende der Corona-Pandemie für die Schweiz zeichnet sich ab. Damit wird sich die Gesundheitspolitik wieder auf ihre Regelstrukturen abstützen und sich statt nur auf die Kapazität der Intensivpflegestationen wieder auf umfassendere Ziele ausrichten können. Eine besondere Bedeutung werden dabei kantonale und überkantonale Corona-Strategien erlangen. = La fin de la pandémie de coronavirus se dessine en Suisse. Ainsi, la politique de la santé pourra s’appuyer à nouveau sur ses structures ordinaires et se recentrer sur des objectifs plus larges que la seule capacité des unités de soins intensifs. Les stratégies cantonales et supracantonales en matière de coronavirus revêtiront une importance particulière

    Insight into volatile behavior at Nyamuragira volcano (D.R. Congo, Africa) through olivine-hosted melt inclusions

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    Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 12 (2011): Q0AB11, doi:10.1029/2011GC003699.We present new olivine-hosted melt inclusion volatile (H2O, CO2, S, Cl, F) and major element data from five historic eruptions of Nyamuragira volcano (1912, 1938, 1948, 1986, 2006). Host-olivine Mg#'s range from 71 to 84, with the exception of the 1912 sample (Mg# = 90). Inclusion compositions extend from alkali basalts to basanite-tephrites. Our results indicate inclusion entrapment over depths ranging from 3 to 5 km, which agree with independent estimates of magma storage depths (3–7 km) based on geophysical methods. Melt compositions derived from the 1986 and 2006 Nyamuragira tephra samples best represent pre-eruptive volatile compositions because these samples contain naturally glassy inclusions that underwent less post-entrapment modification than crystallized inclusions. Volatile concentrations of the 1986 and 2006 samples are as follows: H2O ranged from 0.6 to 1.4 wt %, CO2 from 350 to 1900 ppm, S from 1300 to 2400 ppm, Cl from 720 to 990 ppm, and F from 1500 to 2200 ppm. Based on FeOT and S data, we suggest that Nyamuragira magmas have higher fO2 (>NNO) than MORB. We estimate the total amount of sulfur dioxide (SO2) released from the 1986 (0.04 Mt) and 2006 (0.06 Mt) Nyamuragira eruptions using the petrologic method, whereby S contents in melt inclusions are scaled to erupted lava volumes. These amounts are significantly less than satellite-based SO2 emissions for the same eruptions (1986 = ∼1 Mt; 2006 = ∼2 Mt). Potential explanations for this observation are: (1) accumulation of a vapor phase within the magmatic system that is only released during eruptions, and/or (2) syn-eruptive gas release from unerupted magma.Funding for this work was provided by NSF (grant EAR 0910795 (to SAC) and grant EAR 0646694 (to AMS)), as well as the National Geographic Society (grant 7698-04 (to SAC))

    Untersuchungen bei 53 Kühen mit Boviner Spongiformer Enzephalopathie (BSE)

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    Das Ziel dieser Arbeit war es, das Krankheitsbild der Bovinen Spongiformen Enzephalopathie anhand der letzten 53 Kühe mit BSE am Departement für Nutztiere der Universität Zürich mit klinischen, hämatologischen und biochemischen Daten sowie der Liquorzusammensetzung zu aktualisieren und die wichtigsten Symptome sowie den Untersuchungsgang auf BSE in einem neuen Videofilm darzustellen. Bei der klinischen Allgemeinuntersuchung konnten nur unspezifische Befunde erhoben werden. Beim Untersuchungsgang auf BSE zeigten 52 Kühe Verhaltensstörungen in Form von Ängstlichkeit oder Schreckhaftigkeit (92 %) und/oder Nervosität bzw. Unruhe (81 %). Bei 81 % der Kühe waren sie gleichzeitig vorhanden. Ebenfalls zeigten 52 Kühe eine Störung der Sensibilität, welche sich am häufigsten auf die Berührung mit dem Kugelschreiber (94 %), bei der Blitzprobe (90 %) und bei der Lärmprobe (89 %) äusserte. Alle Kühe wiesen eine Störung der Bewegung auf, welche sich am häufigsten beim Freilaufenlassen manifestierte. Allerdings waren die Bewegungsstörungen oft nur leichtgradig ausgeprägt. Der Passgang wurde bei der Untersuchung oft übersehen und konnte anhand der Auswertung der Videoaufzeichnungen bei 36 % der untersuchten Kühe gefunden werden. Im Videofilm „Klinische Befunde bei Boviner Spongiformer Enzephalopathie (BSE)“ wird der Untersuchungsgang auf BSE an gesunden Kühen an der Klinik, in einem Mutterkuhbetrieb und am Schlachthof demonstriert. Die Symptome der Krankheit werden anhand verschiedener Beispiele in unterschiedlich starker Ausprägung im Rahmen des Untersuchungsganges auf BSE gezeigt. Der Videofilm dauert 38 Min. und ist in deutscher, englischer, französischer und spanischer Sprache auf einer DVD-ROM erhältlich. The goals of this study were twofold. The first was to update clinical, haematological and biochemical findings and results of cerebrospinal fluid analysis in cattle with bovine spongiform encephalopathy (BSE). The second was to make a video film about the most important clinical signs of BSE and the procedures used to examine cattle for this disease. For this purpose, 53 cows with BSE that were referred most recently to the Department of Farm Animals, University of Zurich, were used. A general clinical examination revealed non-specific clinical signs in all cows. A clinical examination for BSE revealed behavioural abnormalities in 52 cows. Anxiety or panic-stricken behaviour was seen in 92% of cows and nervousness and/or restlessness in 81%. Both of these behavioural changes were seen in 81% of cows. Abnormalities in sensitivity were found in 52 cows with the most frequent abnormalities being hypersensitivity to touch with a pen (94%), hypersensitivity to a camera flash (90%) and hypersensitivity to sound (89%). Locomotion was abnormal in all cows, and this was seen most often when the patient was loose in a paddock. However, abnormalities in locomotion tended to be mild. Pacing was often missed during clinical examination, and only when the video footage was reviewed was this abnormal gait seen in 36% of cows. In the video film entitled “Clinical signs of bovine spongiform encephalopathy (BSE)”, the procedures used to examine cattle for BSE are demonstrated using healthy cows at our clinic, healthy cows in a cow-calf operation and cattle at the slaughter house. The clinical signs of BSE are shown during examination of affected cattle in which the severity of the disease varies from mild to severe. The video film is available as a DVD in German, English, French and Spanish
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