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  • 1
    Publication Date: 2015-09-17
    Description: Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McGlynn, Shawn E -- Chadwick, Grayson L -- Kempes, Christopher P -- Orphan, Victoria J -- England -- Nature. 2015 Oct 22;526(7574):531-5. doi: 10.1038/nature15512. Epub 2015 Sep 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA. ; Exobiology Branch, National Aeronautics and Space Administration Ames Research Center, Moffett Field, California 94035, USA. ; Control and Dynamical Systems, California Institute of Technology, Pasadena, California 91125, USA. ; SETI Institute, Mountain View, California 94034, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26375009" target="_blank"〉PubMed〈/a〉
    Keywords: Anaerobiosis ; Archaea/cytology/*metabolism ; Cytochromes/genetics/metabolism/ultrastructure ; Deltaproteobacteria/cytology/*metabolism ; Diffusion ; Electron Transport ; Genome, Archaeal/genetics ; Genome, Bacterial/genetics ; Heme/metabolism ; Methane/*metabolism ; Microbiota/physiology ; Models, Biological ; Molecular Sequence Data ; *Single-Cell Analysis ; Sulfates/metabolism ; *Symbiosis
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 2
    Publication Date: 2016-02-26
    Description: The oxidation of methane with sulfate is an important microbial metabolism in the global carbon cycle. In marine methane seeps, this process is mediated by consortia of anaerobic methanotrophic archaea (ANME) that live in syntrophy with sulfate-reducing bacteria (SRB). The underlying interdependencies within this uncultured symbiotic partnership are poorly understood. We used a combination of rate measurements and single-cell stable isotope probing to demonstrate that ANME in deep-sea sediments can be catabolically and anabolically decoupled from their syntrophic SRB partners using soluble artificial oxidants. The ANME still sustain high rates of methane oxidation in the absence of sulfate as the terminal oxidant, lending support to the hypothesis that interspecies extracellular electron transfer is the syntrophic mechanism for the anaerobic oxidation of methane.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Scheller, Silvan -- Yu, Hang -- Chadwick, Grayson L -- McGlynn, Shawn E -- Orphan, Victoria J -- New York, N.Y. -- Science. 2016 Feb 12;351(6274):703-7. doi: 10.1126/science.aad7154.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26912857" target="_blank"〉PubMed〈/a〉
    Keywords: Anaerobiosis ; *Carbon Cycle ; Electron Transport ; Geologic Sediments/microbiology ; Methane/*metabolism ; Methanosarcinales/classification/genetics/*metabolism ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; RNA, Archaeal/classification/genetics ; Seawater/microbiology ; Sulfates/*metabolism ; Sulfur-Reducing Bacteria/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 3
    Publication Date: 2016-06-11
    Description: Radio pulsars have concentrated on long observations of the Crab pulsar and showed that it emits short intense bursts and a persistent weak periodic flux at gamma-ray energies 1000 GeV. It was shown that the light curve of the persistent emission was dominated by a single peak, coincident with the position of the radio and low energy gamma-ray main pulse. The results of a more detailed analysis of the structure of this main pulse are reported following an appraisal of the timing system. It is shown that at energies 1000 GeV the duration of the main pulse is not greater than 0.4 ms, which is less than that seen at all frequencies other than radio. Flux limits for the emission of 1000 GeV gamma-rays by seven other radio pulsars are reported
    Keywords: SPACE RADIATION
    Type: 19th Intern. Cosmic Ray Conf - Vol. 1; p 155-158; NASA-CP-2376-VOL-1
    Format: application/pdf
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  • 4
    Publication Date: 2019-06-28
    Description: A new very high energy gamma-ray telescope employing the atmospheric Cerenkov light technique and currently nearing completion is described. The telescope is designed to have capability as both a wide angle instrument (4 degree field of view) for sky survey work and as a narrow field of view instrument (1.35 degrees) for conventional drift-scanning and tracking modes of operation. The telescope consists of two 10 sq. m. mirrors operated in fast coincidence with multiple phototube assemblies at the prime focus of each mirror. The design philosophy of the instrument is discussed and comparisons of its performance with our previous telescopes are made.
    Keywords: SPACE RADIATION
    Type: OG-9.4-2 , 19th Intern. Cosmic Ray Conf - Vol. 3; p 406-409; NASA-CP-2376-VOL-3
    Format: application/pdf
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  • 5
    Publication Date: 2019-06-28
    Description: Measurements of 1000 GeV gamma-rays from Cygnus X-3 made with the University of Durham facility at Dugway, Utah in 1981/82 are reviewed. The light curve of the 4.8 hour modulated emission is updated and shows evidence significant at the 4.4 sigma level for strong emission (9% of the cosmic ray rate) at phase 0.625 and less significant (1.4 sigma level) indications of weaker emission (3% of the cosmic ray rate) at phase 0.125. The effect constituting the excess on the few nights showing the strongest emission appears to arise from the smallest Cerenkov light signals suggesting a steep gamma-ray spectrum. The 1982 data have been searched unsuccessfully for evidence of emission at phase 0.2, in coincidence with the results from the ultra-high energy (extensive Air Showers (EAS) measurements in 1979-1982. A systematic investigation of a long term variation in the strength of the peak of the 4.8 hr modulated 1000 GeV gamma-ray emission has been made. We find that in addition to the approximately 34 d variation reported by us previously, a stronger effect exists at around 19d.
    Keywords: SPACE RADIATION
    Type: OG-2.1-8 , 19th Intern. Cosmic Ray Conf - Vol. 1; p 79-82; NASA-CP-2376-VOL-1
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  • 6
    Publication Date: 2019-06-28
    Description: The detection of 1000 GeV gamma-rays with the characteristic 6.1 ms periodicity of the radio pulsar PSR 1953 +29 is reported. This result, significant at the 5.4 beta level, provides the first direct evidence for the association of the 6 ms radio pulsar PSR1953+29 with the gamma-ray source 2CG065+0. Extensive observations of the 1.5 ms pulsar PSR 1937 are also reported.
    Keywords: SPACE RADIATION
    Type: OG-2.3-12 , 19th Intern. Cosmic Ray Conf - Vol. 1; p 161-164; NASA-CP-2376-VOL-1
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  • 7
    Publication Date: 2019-06-28
    Description: Following the discovery of Her X-1 as a source of pulsed 1000 Gev X-rays, a search for emission from an X-ray binary containing a pulsar with similar values of period, period derivative and luminosity was successful. The sporadic X-ray binary 4U 0115-63 has been observed, with probability 2.5 x 10 to the minus 6 power ergs/s to emit 1000 GeV gamma-rays with a time averaged energy flux of 6 to 10 to the 35th power.
    Keywords: SPACE RADIATION
    Type: OG-2.6-11 , 19th Intern. Cosmic Ray Conf - Vol. 1; p 251-254; NASA-CP-2376-VOL-1
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 7 (1973), S. 1241-1251 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Semi-empirical molecular orbital calculations have been carried out on the steroidal hormone estrone, both as a neutral molecule and the corresponding positively charge molecular ion. These calculations provide estimates of bond densities and net atomic charges, factors deemed important in past correlations of observed mass spectra with molecular structure. Calculated net charges appear to be unrelated to fragmentation processes. Calculated bond densities of the ground state molecular ion of estrone allow prediction of gross features of fragmentation. Bond densities of excited electronic states of the molecular ion may provide a basis for finer distinction among sites of initial bond cleavage, which is information crucial to rationalization of subsequent fragmentation of the molecular ion.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 25 (1987), S. 251-255 
    ISSN: 0749-1581
    Keywords: 9-methoxyfluorene ; NMR ; MNDO ; ab intio calculations ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The results of NMR investigations based on the heteronuclear 3J(CH3, H-9) coupling constant, the methyl group chemical shift, lanthanide-induced shifts and MNDO calculations indicate that 9-methoxyfluorene exists predominantly in the trans conformation in which the methyl group is oriented in an antiperiplanar relationship with respect to H-9. Previous experimental work on the 9-hydroxy analogue demonstrated a similar conformational preference, which is also indicated by the results of MNDO and ab initio calculations presented here. The origin of the preference probably lies in a repulsive interaction between the electrons of the aromatic π-systems and the lone-pair electrons of the hydroxyl or methoxyl oxygen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 9 (1980), S. 1-4 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The interaction of iodine cyanide and cyanide in aqueous solution has been reinvestigated and it has been confirmed that a complex cyanide ion, the dicyanoiodate(I) ion [I(CN)2]- is formed. This ion has been isolated in the solid state for the first time, as its tetraphenylarsonium, tetraphenylphosphonium and caesium salts. Infrared and Raman spectroscopic studies of these salts are reported. These spectra are fully consistent with a linear centrosymmetric (D∞h) structure for the [I(CN)2]-ion. Assignments are made for six of the seven fundamentals of the [I(CN)2]-ion in the caesium salt.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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