671 research outputs found

    Developing a Laser Induced Liquid Beam Ion Desorption Spectral Database as Reference for Spaceborne Mass Spectrometers

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    Spaceborne impact ionization mass spectrometers, such as the Cosmic Dust Analyzer on board the past Cassini spacecraft or the SUrface Dust Analyzer being built for NASA's upcoming Europa Clipper mission, are of crucial importance for the exploration of icy moons in the Solar System, such as Saturn's moon Enceladus or Jupiter's moon Europa. For the interpretation of data produced by these instruments, analogue experiments on Earth are essential. To date, thousands of laboratory mass spectra have been recorded with an analogue experiment for impact ionization mass spectrometers. Simulation of mass spectra of ice grains in space is achieved by a Laser Induced Liquid Beam Ion Desorption (LILBID) approach. The desorbed cations or anions are analyzed in a time-of-flight mass spectrometer. The amount of unstructured raw data is increasingly challenging to sort, process, interpret and compare with data from space. Thus far this has been achieved manually for individual mass spectra because no database containing the recorded reference spectra was available. Here we describe the development of a comprehensive, extendable database containing cation and anion mass spectra from the laboratory LILBID facility. The database is based on a Relational Database Management System with a web server interface and enables filtering of the laboratory data using a wide range of parameters. The mass spectra can be compared not only with data from past and future space missions but also mass spectral data generated by other, terrestrial, techniques. The validated and approved subset of the database is available for general public (https://lilbid-db.planet.fu-berlin.de)

    German Geographical Research on North America : A Bibliography with Comments and Annotations

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    The 27th International Geographical Congress in Washington, D.C., 1992 is the first geographical congress to take place in the United States for 40 years. This event and the 40th anniversaiy of the readmittance of Germany into the IGU offer a welconte opportunity of providing the international scientific Community with a survey of the research on North America by German and German speaking geographers in the form of a commentated bibliography

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    BĂŒcher in der Diskussion - Thema Bildung: 1) Horlacher, Rebekka: Bildung. UTB Profile. Bern: Haupt 2011. ISBN 978-3-8252-3522-2. 2) Lenz, Werner: Wertvolle Bildung - kritisch 
 skeptisch 
 sozial. Wien: Löcker 2011. ISBN 978-85409-591-0. 3) Maaser, Michael; Walther, Gerrit: Bildung - Ziele und Formen, Traditionen und Systeme, Medien und Akteure. Stuttgart: J.B. Metzler‘sche Verlagsbuchhandlung 2011. ISBN 978-3-476-02098-7. 4) Roth, Gerhard: Bildung braucht Persönlichkeit - wie Lernen gelingt. Stuttgart: Klett-Cotta 2011, 3. Aufl. ISBN 978-3-608-94655-0. / Rezensionen zu: 5) Möller, Svenja: Marketing in der Erwachsenenbildung. Bielefeld: W. Bertelsmann 2011. ISBN 978-3-7639-4902-1. 6) Rikowski-Bertsch, Anke: Die grundtvigsche Volkshochschule als Idee und Institution und ihre Rezeption fĂŒr die Erwachsenenbildung heute. SaarbrĂŒcken: VDM Verl. Dr. MĂŒller 2010. ISBN 978-3-639-23580-7. 7) Horst Siebert: Lernen und Bildung Erwachsener. Erwachsenenbildung und lebensbegleitendes Lernen, Bd. 17. Bielefeld: W. Bertelsmann 2011. ISBN 978-3-7639-4848-2. 8) Egloff, Birte; GrotlĂŒschen, Anke (Hrsg.): Forschen im Feld der Alphabetisierung und Grundbildung: ein Werkstattbuch. MĂŒnster: Waxmann 2011. ISBN 978-3-8309-2463-0. 9) Kathrin Berdelmann: Operieren mit der Zeit: Empirie und Theorie von Zeitstrukturen in Lehr-/Lernprozessen. Paderborn: Schöningh 2010. ISBN 978-3-506-77041-7. 10) Peter Faulstich: AufklĂ€rung, Wissenschaft und lebensentfaltende Bildung. Geschichte und Gegenwart einer großen Hoffnung der Moderne. Bielefeld. Transcript-Verl. 2011. ISBN 978-3-8376-1816-7

    Experimental discovery of sRNAs in Vibrio cholerae by direct cloning, 5S/tRNA depletion and parallel sequencing

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    Direct cloning and parallel sequencing, an extremely powerful method for microRNA (miRNA) discovery, has not yet been applied to bacterial transcriptomes. Here we present sRNA-Seq, an unbiased method that allows for interrogation of the entire small, non-coding RNA (sRNA) repertoire in any prokaryotic or eukaryotic organism. This method includes a novel treatment that depletes total RNA fractions of highly abundant tRNAs and small subunit rRNA, thereby enriching the starting pool for sRNA transcripts with novel functionality. As a proof-of-principle, we applied sRNA-Seq to the human pathogen Vibrio cholerae. Our results provide information, at unprecedented depth, on the complexity of the sRNA component of a bacterial transcriptome. From 407 039 sequence reads, all 20 known V. cholerae sRNAs, 500 new, putative intergenic sRNAs and 127 putative antisense sRNAs were identified in a limited number of growth conditions examined. In addition, characterization of a subset of the newly identified transcripts led to the identification of a novel sRNA regulator of carbon metabolism. Collectively, these results strongly suggest that the number of sRNAs in bacteria has been greatly underestimated and that future efforts to analyze bacterial transcriptomes will benefit from direct cloning and parallel sequencing experiments aided by 5S/tRNA depletion

    Distant Field BHB Stars III: Identification of a probable outer halo stream at Galactocentric distance r = 70 kpc

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    We present VLT-FORS1 spectra of a sample of 34 faint 20.0 < g* < 21.1 A-type stars selected from the Sloan Digital Sky Survey Early Data Release, with the goal of measuring the velocity dispersion of blue horizontal branch (BHB) stars in the remote Galactic halo, R~80kpc. We show that colour selection with 1.08 < u*-g* < 1.40 and -0.2 < g*-r* < -0.04 minimises contamination of the sample by less luminous blue stragglers. In classifying the stars we confine our attention to the 20 stars with spectra of signal-to-noise ratio > 15 per Angstrom. Classification produces a sample of eight BHB stars at distances 65-102 kpc from the Sun (mean 80 kpc), which represents the most distant sample of Galactic stars with measured radial velocities. The dispersion of the measured radial component of the velocity with respect to the centre of the Galaxy is 58+-15km/s. This value is anomalously low in comparison with measured values for stars at smaller distances, as well as for satellites at similar distances. Seeking an explanation for the low measured velocity dispersion, further analysis reveals that six of the eight remote BHB stars are plausibly associated with a single orbit. Three previously known outer halo carbon stars also appear to belong to this stream. The velocity dispersion of all nine stars relative to the orbit is only 15+-4 km/s. Further observations along the orbit are required to trace the full extent of this structure on the sky.Comment: 13 pages, 7 figures. Accepted for publication in MNRA

    The AP-1-BATF and -BATF3 module is essential for growth, survival and TH17/ILC3 skewing of anaplastic large cell lymphoma.

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    Transcription factor AP-1 is constitutively activated and IRF4 drives growth and survival in ALK+ and ALK- anaplastic large cell lymphoma (ALCL). Here we demonstrate high-level BATF and BATF3 expression in ALCL. Both BATFs bind classical AP-1 motifs and interact with in ALCL deregulated AP-1 factors. Together with IRF4, they co-occupy AP-1-IRF composite elements, differentiating ALCL from non-ALCL. Gene-specific inactivation of BATFs, or global AP-1 inhibition results in ALCL growth retardation and/or cell death in vitro and in vivo. Furthermore, the AP-1-BATF module establishes TH17/group 3 innate lymphoid cells (ILC3)-associated gene expression in ALCL cells, including marker genes such as AHR, IL17F, IL22, IL26, IL23R and RORÎłt. Elevated IL-17A and IL-17F levels were detected in a subset of children and adolescents with ALK+ ALCL. Furthermore, a comprehensive analysis of primary lymphoma data confirms TH17-, and in particular ILC3-skewing in ALCL compared with PTCL. Finally, pharmacological inhibition of RORC as single treatment leads to cell death in ALCL cell lines and, in combination with the ALK inhibitor crizotinib, enforces death induction in ALK+ ALCL. Our data highlight the crucial role of AP-1/BATFs in ALCL and lead to the concept that some ALCL might originate from ILC3

    Clinical relevance of molecular characteristics in Burkitt lymphoma differs according to age

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    While survival has improved for Burkitt lymphoma patients, potential differences in outcome between pediatric and adult patients remain unclear. In both age groups, survival remains poor at relapse. Therefore, we conducted a comparative study in a large pediatric cohort, including 191 cases and 97 samples from adults. While TP53 and CCND3 mutation frequencies are not age related, samples from pediatric patients showed a higher frequency of mutations in ID3, DDX3X, ARID1A and SMARCA4, while several genes such as BCL2 and YY1AP1 are almost exclusively mutated in adult patients. An unbiased analysis reveals a transition of the mutational profile between 25 and 40 years of age. Survival analysis in the pediatric cohort confirms that TP53 mutations are significantly associated with higher incidence of relapse (25 ± 4% versus 6 ± 2%, p-value 0.0002). This identifies a promising molecular marker for relapse incidence in pediatric BL which will be used in future clinical trials
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