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We measured the concentrations and isotopic compositions of He Ne and Ar in 14 fragments from 12 different meteorites: three carbonaceous chondrites six L chondrites (three most likely paired) one H chondrite one R chondrite and one ungrouped chondrite. The data obtained for the CV3 chondrites Ramlat as Sahmah (RaS) 221 and RaS 251 support the hypothesis of exposure age peaks for CV chondrites at approximately 9Ma and 27Ma. The exposure age for Shir 033 (CR chondrite) of 7.3Ma is also indicative of a possible CR chondrite exposure age peak. The three L chondrites Jiddat al Harasis (JaH) 091 JaH 230 and JaH 296 which are most likely paired fall together with Hallingeberg into the L chondrite exposure age peak of approximately 15Ma. The two L chondrites Shelburne and Lake Torrens fall into the peaks at approximately 40Ma and 5Ma respectively. The ages for Bassikounou (H chondrite) and RaS 201 (R chondrite) are approximately 3.5Ma and 5.8Ma respectively. Six of the studied meteorites show clear evidence for 3He diffusive losses the deficits range from approximately 17 for one Lake Torrens aliquot to approximately 45 for RaS 211. The three carbonaceous chondrites RaS 221 RaS 251 and Shir 033 all have excess 4He either of planetary or solar origin. However very high 4He/20Ne ratios occur at relatively low 20Ne/22Ne ratios which is unexpected and needs further study. The measured 40Ar ages fit well into established systematics. They are between 2.5 and 4.5Ga for the carbonaceous chondrites older than 3.6Ga for the L and H chondrites and about 2.4Ga for the R chondrite as well as for the ungrouped chondrite. Interestingly none of our studied L chondrites has been degassed in the 470Ma break up event. Using the amount of trapped 36Ar as a proxy for noble gas contamination due to terrestrial weathering we are able to demonstrate that the samples studied here are not or only very slightly affected by terrestrial weathering (at least in terms of their noble gas budget).

Background: Leukotrienes are pivotal lipid mediators in various immune and inflammatory reactions. Herein, 5-LO is a validated target. 2-Aminothiazoles, as a privileged structure, implicate known 5-LO inhibitors like ST-1083 (IC50 [polymorphonuclear leukocytes (PMNL)] = 0.68 mM), yet deep structure-activity relationships (SAR) have not been established. Materials & methods: Compounds were synthesized via Hantzsch thiazole synthesis. Inhibitory activities were evaluated using intact PMNL and purified 5-LO together with cytotoxicity measurements in U937 cells. Results: We introduced novel functionalities at 2-, 3-, 4- and 5-position of the 2-aminothiazole scaffold and conducted bioisosteric replacement to optimize the parent scaffold. SARs of the 2-aminothiazole scaffold were deduced and extended primarily for inhibition of the 5-LO enzyme. Conclusion: SAR studies provided at least two optimized leads (ST-1853, ST-1906) with high potency (IC50 [polymorphonuclear leukocytes] = 0.05 mM), specificity and noncytotoxic behavior.

Leukotrienes (LTs) are inflammatory mediators that play a pivotal role in many diseases like asthma bronchiale, atherosclerosis and in various types of cancer. The key enzyme for generation of LTs is the 5-lipoxygenase (5-LO). Here, we present a novel putative protein isoform of human 5-LO that lacks exon 4, termed 5-LOD4, identified in cells of lymphoid origin, namely the Burkitt lymphoma cell lines Raji and BL41 as well as primary B and T cells. Deletion of exon 4 does not shift the reading frame and therefore the mRNA is not subjected to non-mediated mRNA decay (NMD). By eliminating exon 4, the amino acids Trp144 until Ala184 are omitted in the corresponding protein. Transfection of HEK293T cells with a 5-LOD4 expression plasmid led to expression of the corresponding protein which suggests that the 5-LOD4 isoform is a stable protein in eukaryotic cells. We were also able to obtain soluble protein after expression in E. coli and purification. The isoform itself lacks canonical enzymatic activity as it misses the non-heme iron but it still retains ATP-binding affinity. Differential scanning fluorimetric analysis shows two transitions, corresponding to the two domains of 5-LO. Whilst the catalytic domain of 5-LO WT is destabilized by calcium, addition of calcium has no influence on the catalytic domain of 5-LOD4. Furthermore, we investigated the influence of 5-LOD4 on the activity of 5-LO WT and proved that it stimulates 5-LO product formation at low protein concentrations. Therefore regulation of 5-LO by its isoform 5-LOD4 might represent a novel mechanism of controlling the biosynthesis of lipid mediators.

The sequence of dyke intrusions between 2005 and 2010 in the Manda Hararo rift segment, Ethiopia, provided an opportunity to test conceptual models of continental rifting. Based on trends up to dyke 13 in the sequence, it was anticipated that, should magma supply con- tinue, dykes would shorten in length and eruptions would increase in size and decrease in distance from the segment centre as extensional stress was progressively released. In this paper we revisit these predictions by presenting a comprehensive overview of the May 2010 dyke and fissure erup- tion, the 14th and last in the sequence, from InSAR, seismicity, satellite thermal data, ultraviolet SO2 retrievals and multiple LiDAR surveys. We find the dyke is longer than other eruptive dykes in the sequence, propagating in two directions from the segment centre, but otherwise fairly typical in terms of opening, propagation speed and geodetic and seismic moment. However, though the eruption is located closer to the segment centre, it is much smaller than pre- vious events. We interpret this as indicating that either the Manda Hararo rifting event was magma limited, or that extensional stress varies north and south of the segment centre.

We describe a new high-purity germanium (HPGe) detector setup for low-background ��-ray spectrometry. The GeMSE facility (Germanium Material and meteorite Screening Experiment) is dedicated to material screening for rare event searches in astroparticle physics as well as to the characterization of meteorites. It is installed in a medium depth (~620 m.w.e.) underground laboratory in Switzerland in a multi-layer shielding and is equipped with an active muon veto. We have reached a very competitive integral background rate of (246$\pm$2) counts/day (100-2700 keV) and measured a sensitivity of $\sim$0.5-0.6 mBq/kg for long-lived isotopes from the $^{238}$U/$^{232}$Th chains in a $\sim$1\,kg sample screened for $\sim$27 days. An extrapolation to higher sample masses and measurement times suggests a maximum sensitivity in the $\mathcal{O}(50)$ ��Bq/kg range. We describe the data analysis based on Bayesian statistics, background simulations, the efficiency calibration and first sample measurements.

Introduction: The main mass of the Twannberg meteorite (15.9 kg) has been found 1984 in the Canton of Bern, Switzerland. The Twannberg meteorite belongs to the IIG group, which comprises so far only six members and which is characterized by large amounts of schreibersite (Fe,Ni)3P and a low nickel content of 5% only [1]. Twannberg is so far the largest meteorite found in Switzerland. Recent research campaigns have increased the amount of recovered material yielding to a total mass of ~70 kg in ~550 individual pieces. In this study, we analyzed 17 individual samples and calculated their cosmic ray exposure (CRE) age using cosmogenic noble gases and radionuclides. We applied updated Monte-Carlo model calculations to determine (i) the preatmospheric size, (ii) the cosmic ray exposure age, and (ii), especially, the terrestrial age of Twannberg to better understand its relation to the last glaciation event in Europe [1]. Experimental methods: The isotopic concentrations for He, Ne, and Ar have been measured by noble gas mass spectrometry at the University of Bern following procedures described earlier [2,3]. Analyses of the cosmogenic radionuclides (i.e., 10Be, 26Al, 36Cl, and 41Ca) have been performed at the DREsden Accelerator Mass Spectrometry facility (DREAMS, [4]) using procedures described in [5]. Results: In total, 17 samples have been analyzed for noble gas concentrations; seven of them have also been investigated for their cosmogenic radionuclide contents. We observe a wide range of noble gas and radionuclide concentrations of more than one order of magnitude among the different samples. The noble gas and radionuclide concentrations linearly correlate, demonstrating the reliability of the analysis despite low concentrations. Combining the data with improved model calculations indicate a preatmospheric radius of up to 10 m. Considering an average density of about 8 g/cm3 and assuming a spherical object, the preatmospheric mass of Twannberg was most likely larger than 33000 tons. The CRE age for Twannberg, which has been determined using the 36Cl-36Ar method [6], is 236±50 Ma, which is in the range of typical CRE ages for iron meteorites [7] and which is in good agreement with the adopted age of 230±50 Ma found previously [1]. More importantly, the mean terrestrial age based on 41Ca-36Cl systematics and up-dated Monte-Carlo calculations is 165±58 ka. The age therefore indicates that Twannberg most likely fell during the second last glaciation (~185-130 ka), or even during one of the two last (~130-115 ka) or (~225-185 ka) interglacials. Research campaigns in the field are still ongoing and we hope for a further recoveries of Twannberg material. References: [1] Hofmann B. et al. 2009. Meteoritics and Planetary Science 44:187-199. [2] Ammon K. et al. 2008. Meteoritics and Planetary Science 43:685-699. [3] Ammon K. et al. 2011. Meteoritics and Planetary Science 46:785-792. [4] Rugel G. et al. 2016. Nuclear Instruments and Methods in Physics B 370:94-100. [5] Merchel S. and Herpers U. 1999. Radiochimica Acta 84:215-219. [6] Lavielle B. et al. 1999. Earth and Planetary Science Letters 170:93-104. [7] Eugster O. 2003. Chemie der Erde-Geochemistry 63:3-30. Acknowlegments: This study heavily relies on samples collected in a great effort by a joint group of meteorite enthusiasts and scientists. We particularly thank for the collaboration and samples: Marc Jost, Manuel Eggimann, Hannes Weiss, Sergey Vasiliev, Andreas Koppelt, Ernst Wyler, Gino Bernasconi, Marcel Häuselmann, and Edwin Gnos. This work is supported by the Swiss National Science Foundation (SNF).

We tested a handheld X ray fluorescence instrument with adaptable matrix correction for its suitability in meteoritics. We report here the instrument setup precision and accuracy and present examples of applications. With a measuring time of 300 s it is possible to collect accurate data for K Ca Ti Cr Mn Fe Co Ni Sr and Ba that are needed for the identification of doubtful meteorites and the nondestructive classification of chondrites and achondrites. The factory supplied calibration curve of the instrument was fine tuned for our purposes with the use of well analyzed meteorite powders pressed pellets and meteorite hand specimens as standards. Relative errors of 10 to 20 are reached for the mentioned elements. The instrument was tested in the hot desert of Oman while searching for meteorites and also in the laboratory while doing research on meteorites. The main applications of the instrument are the identification and classification of meteorites the quantification of terrestrial elemental contamination (Sr and Ba) and detection of Mn rich desert varnish. It is possible to discriminate the major meteorite groups using Fe/Mn and Ni values. Handheld X ray fluorescence is also useful in identifying meteorites belonging to the same fall event.

Introduction: The 15.9 kg main mass of the Twannberg meteorite has been found in 1984 in the Canton of Bern, Switzerland. Five additional masses were found until 2007 [1]. Since then, nearly 100 new finds brought the known mass to ~37 kg. The Twannberg meteorite belongs to the small IIG group (6 members), which is characterized by a low concentration of nickel and large inclusions of schreibersite. Here we study the cosmic ray exposure (CRE) history of 17 individuals of Twannberg using cosmogenic radionuclides and noble gases. We are especially interested in the terrestrial age of Twannberg to better understand its relation with the associated glacial sediments. Experimental Methods: Noble gas isotopes (He, Ne, and Ar) are analyzed by noble gas mass spectrometry at the University of Bern following procedure described earlier [2,3]. Analyses of the cosmogenic radionuclides (10Be, 26Al, 36Cl, and 41Ca) are performed at the DREsden Accelerator Mass Spectrometry facility (DREAMS, [4]) adapted from procedures described in [5]. Results: So far, 17 samples have been analyzed for the noble gas; 6 of them have also been investigated for their cosmogenic radionuclide contents. We observed a wide range of noble gas and radionuclide concentrations (more than one order of magnitude). The noble gas and radionuclide concentration correlate, indicating the reliability of the analysis despite low concentrations. Combining the data with model calculations indicate a preatmospheric radius in range of 1 to 10 meters. Considering an average density of about 8 g/cm3 and assuming a spherical object, the Twannberg preatmospheric mass was greater than at least 33 tons. The CRE age has been determined using the 36Cl-36Ar method [6]. The average CRE age is 243±64 Ma, which is in the range of typical CRE ages for iron meteorites [7] and which is in good agreement with the adopted age of 230±50 Ma found previously [1]. The average terrestrial age based on the 36Cl/10Be-10Be systematics is 88±38 ka, indicating that the meteorite fell during the last glaciation, the Würm event (~110-15 ka), but before the maximum glaciation at 24 ka. We expect 41Ca measurements soon, which will help to further pin down the terrestrial age of the Twannberg meteorite and bring the fall into context of glacial events, as suggested by geological indicators [1]. References: [1] Hofmann B. et al. 2009. Meteoritics and Planetary Science 44:187-199. [2] Ammon K. et al. 2008. Meteoritics and Planetary Science 43:685-699. [3] Ammon K. et al. 2011. Meteoritics and Planetary Science 46:785-792. [4] Akhmadaliev S. et al. 2013. Nuclear Instruments and Methods in Physic B 294:5-10. [5] Merchel S. and Herpers U. 1999. Radiochimica Acta 84:215-219. [6] Lavielle B. et al. 1999. Earth and Planetary Science Letters 170:93-104. [7] Eugster O. 2003. Chemie der Erde-Geochemistry 63:3-30. Acknowledgments: This work is supported by the Swiss National Science Foundation. We thank all the ion beam center members in Dresden for their precious help. This study is heavily based on a close cooperation with enthusiastic meteorite hunters.

Hard, Confusing, Entertaining is any attempt to understand James’ joys, or the details of the commodius vicus recirculation of molybdenum. Molybdenum (Mo) is a redox-sensitive element whose isotope fractionation in oceanic sediments is being established as a proxy for paleo-oceano-graphic conditions. In order to constrain the oceanic Mo cycle, it is necessary to understand its sources. The average Mo riverrun influx to the oceans is not well established. Crystalline continental crust has a lighter isotopic composi-tion than oceanic Mo by about 2 permil. We report here Mo isotopic compositions and concentrations from several closely-spaced river catchment profiles. We selected our sampling in such a way to monitor, for each sample suite, one or more of the following potential controlling factors: base-ment geology; fractionation during weathering; within-river precipitation (including lakes); anthropogenic contamination. Our results show variable deviations of dissolved river Mo from average crystalline continental crust, between 0 and 1.9 permil. We observe a positive, but not simple, cor-relation between Mo concentration and isotopic composi-tion, indicating that the riverine Mo system and thus global continental runoff are highly complex. Neither steady-state soil adsorption nor within-river precipitation cause a major isotopic fractionation. Weathering and labo-ratory leaching may lead to transient fractionation in some cases. The control by basement geology in most other cases is evident and can be documented in great detail along river transects and in tributaries; rock analyses supplement water analyses and confirm lithological control. Two very prominent effects are weathering of sedimentary (evaporitic) sulfates and oxidative weathering of sulfides. Several sub-economic molybdenite (MoS2) occurrences in the Swiss Alps contribute isotopically variable Mo. Disseminated pyrite occurs in most magmatic, metamorphic and sedimentary rocks, with variable Mo concentrations. The weathering style (glacial vs. non-glacial) has an extremely high influence on dissolved Mo concentration in rivers. In our samples anthropogenic effects appear to be subordinate except in areas of intensive use of agricultural fertilizers.