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  • 1
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    Manganese-rich brown layers in Arctic Ocean sediments: Composition, formation mechanisms, and diagenetic overprint (2011)
    Elsevier
    In:  EPIC3Geochimica et Cosmochimica Acta, Elsevier, 75, pp. 7668-7687
    Details
    Publication Date: 2019-07-16
    Description: We present inorganic geochemical analyses of pore waters and sediments of two Late Quaternary sediment cores from the western Arctic Ocean (southern Mendeleev Ridge, RV Polarstern Expedition ARK-XXIII/3), focussing on the composition and origin of distinct, brown-colored, Mn-rich sediment layers. Carbonate enrichments occur in association with these layers as peaks in Ca/Al, Mg/Al, Sr/Al and Sr/Mg, suggesting enhanced input of both ice-rafted and biogenic carbonate. For the first time, we show that the Mn-rich layers layers are also consistently enriched in the scavenged trace metals Co, Cu, Mo and Ni. Distinct bioturbation patterns, specifically well-defined brown burrows into the underlying sediments, suggest these metal enrichments formed close to the sediment–water interface. The geochemical signature of these metal- and carbonate-rich layers most probably documents formation under warmer climate conditions with an intensified continental hydrological cycle and only seasonal sea ice cover. Both rivers and sea ice delivered trace metals to the Arctic Ocean, while enhanced seasonal productivity exported reactive organic matter to the sea floor. The coeval deposition of organic matter, Mn (oxyhydr)oxides and trace metals triggered intense diagenetic Mn cycling at the sediment–water interface. These processes resulted in the formation of Mn and trace metal enrichments, and the degradation of labile organic matter. With the onset of cooler conditions, reduced riverine runoff and/or a solid sea ice cover terminated the input of riverine trace metal and fresh organic matter, resulting in deposition of grayish-yellowish, metal-poor sediments. Oxygen depletion of Arctic bottom waters under these cooler conditions is not supported by our data, and did not cause the sedimentary Mn distribution. While the original composition and texture of the brown layers resulted from specific climatic conditions and corresponding diagenetic processes, pore water data show that diagenetic Mn redistribution is still affecting the organic-poor deeper sediments. Given persistent steady state conditions, purely authigenic Mn-rich brown layers may form, while others may be partly or completely dissolved. The degree of diagenetic Mn redistribution largely depends on the depositional environment, the Mn and organic matter availability, and apparently affected the Co/Mo ratios of Mn-rich layers. Thus, brown Arctic layers are not necessarily synchronous features, and should not be correlated across the Arctic Ocean without additional age control.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 2
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    Comparison of Automatic DSM Generation Modules by Processing IKONOS Stereo Data of an Urban Area (2010)
    In:  EPIC3IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 3(2), pp. 162 - 167, ISSN: 1939-1404
    Details
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 3
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    A summary review of wider Caribbean fisheries and their relationships to sea turtles, marine mammals and seabirds (2021)
    In:  http://aquaticcommons.org/id/eprint/13235 | 9596 | 2014-02-04 00:02:41 | 13235 | Gulf and Caribbean Fisheries Institute
    Details
    Publication Date: 2021-07-09
    Description: Item includes an abstract in Spanish. Page range is taken from table of contents for proceedings volume (page numbers in article are incorrect due to publishing error).
    Keywords: Fisheries ; GCFI
    Repository Name: AquaDocs
    Type: conference_item
    Format: application/pdf
    Format: application/pdf
    Format: 391-394
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  • 4
    Electronic Resource
    Electronic Resource
    Mechanically induced growth-disorder high-T"c-Josephson-junctions
    Amsterdam : Elsevier
    Physica C: Superconductivity and its applications 235-240 (1994), S. 3347-3348 
    Details
    ISSN: 0921-4534
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0921-4534(94)91200-9
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  • 5
    Electronic Resource
    Electronic Resource
    Geographic Differences in Bone Turnover: Data from a Multinational Study in Healthy Postmenopausal Women (1998)
    Springer
    Calcified tissue international 63 (1998), S. 277-282 
    Details
    ISSN: 1432-0827
    Keywords: Key words: Bone markers — Bone metabolism — Osteoporosis — Geography — Epidemiology.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. Biochemical markers of bone metabolism (bone markers) are used increasingly to monitor response to therapy and may be predictors of bone loss and fractures. The relationship between fracture rates, which differ between countries, and the rate of bone turnover has not been examined. Therefore, we explored the geographic variability of bone turnover in a selected, healthy study population of 619 postmenopausal women, ages 40–61, participating in a clinical trial of raloxifene hydrochloride for osteoporosis prevention. The subjects were distributed among 38 investigative sites in 10 countries (9–211 subjects/country) on four continents (North America, n = 277, Europe, n = 168, Australia, n = 125, and Africa, n = 49). Specimens for serum osteocalcin (OC), bone-specific alkaline phosphatase (BSAP), and urine type I collagen fragment/urinary creatinine ratio (CTX) were handled in a uniform fashion and assayed in a central laboratory. Mean levels of OC (P 〈 0.001), BSAP (P= 0.006), and CTX (P 〈 0.001) varied significantly by country (ANOVA), with the lowest values typically in German and Spanish subjects and the highest in American and Canadian subjects. The consistent pattern and wide ranges of mean bone marker values (OC 1.6-fold, BSAP 1.7-fold, CTX 3.1-fold) between countries suggest clinically significant differences in bone turnover. Geographic differences in bone markers were not explained by the determined potential confounders of age, years posthysterectomy, total serum cholesterol, and serum follicle stimulating hormone (FSH). We conclude that bone marker values vary substantially by country in this selected study population, suggesting systematic geographic differences in bone metabolism that potentially relate to osteoporotic fracture rates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002239900526
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  • 6
    Electronic Resource
    Electronic Resource
    The tryptophan synthase-encoding trpB gene of Aspergillus nidulans is regulated by the cross-pathway control system (2000)
    Springer
    Molecular genetics and genomics 263 (2000), S. 867-876 
    Details
    ISSN: 1617-4623
    Keywords: Key words Tryptophan synthase ; Aspergillus nidulans ; Amino acid biosynthesis ; Cross-pathway control ; Vacuolar ATP synthase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The tryptophan synthase-encoding gene, trpB, of Aspergillus nidulans was cloned and characterized. It was mapped to chromosome I, between the gene medA, which is required for sexual and asexual development, and an ORF encoding a protein with significant similarity to subunit B of vacuolar ATP synthases. The 5′ untranslated region was found to be at least 142 nucleotides (nt) long, the poly(A) addition site was localized at position +216 relative to the stop codon by sequencing of several independent cDNA clones. The trpB gene contains two exons separated by an intron of 105 nt, which is located close to the 5′ end of the ORF. Directly upstream of the transcriptional start site, one well conserved potential binding site for the cross-pathway control transcriptional activator CPCA was found. The level of trpB transcript was shown to be regulated by cross-pathway control. A knockout mutant for trpB displays tryptophan auxotrophy, no trpB transcript is detectable, and development is perturbed to an extent that is dependent on the amount of tryptophan added to the medium. The trpB gene encodes a protein of 723 amino acids, with a calculated molecular weight of 77.6 kDa. The deduced amino acid sequence shows 72.6% similarity to the tryptophan synthase of Neurospora crassa. Most amino acid residues essential for catalytic activity in the tryptophan synthase of Salmonella typhimurium are conserved. The linker region joining the two domains of the enzyme is 13 residues longer than the longest connector found so far in tryptophan synthases from fungi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380000250
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  • 7
    Electronic Resource
    Electronic Resource
    Developmental and metabolic regulation of the phosphoglucomutase-encoding gene, pgmB, of Aspergillus nidulans (2000)
    Springer
    Molecular genetics and genomics 262 (2000), S. 1001-1011 
    Details
    ISSN: 1617-4623
    Keywords: Key words Phosphoglucomutase ; pgmB ; Aspergillus nidulans ; Carbon metabolism ; Transcriptional regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated the pgmB gene from Aspergillus nidulans, which encodes a phosphoglucomutase, one of the key enzymes in carbohydrate metabolism. The pgmB gene is located on chromosome VII and its ORF encodes 557 amino acids. Mutant phenotypes were analysed by expression of high levels of pgmB antisense RNA, which lead to a loss of detectable levels of sense RNA. Under conditions of antisense RNA expression, a 30% reduction in the growth rate was observed in comparison to wild-type. On the enzyme level, expression of pgmB antisense RNA resulted in a 35% reduction in total phosphoglucomutase activity. Two pgmB mRNAs were observed under all conditions tested and differ with respect to the location of the poly(A) site. Expression of pgmB driven by the GAL1 promoter in Saccharomyces cerevisiae complemented the growth phenotype of a pgm2Δ mutant strain and suppressed the sensitivity of a gcn4Δ mutant strain to amino acid starvation in the presence of galactose. Cultivation of A. nidulans in the presence of glucose or galactose as carbon source did not affect transcription of pgmB. However, amino acid starvation conditions resulted in a six-fold reduction in the level of pgmB mRNA, while genes for amino acid biosynthesis showed increased transcription. Transcription of pgmB was low during hyphal growth and in the sexual phase of development, but was significantly increased during the asexual stage of the A. nidulans life cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008643
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  • 8
    Electronic Resource
    Electronic Resource
    Synthese von bipolaren Ionenaustauscherharzen (1987)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 483-492 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Bipolar Ion Exchange ResinsSyntheses of weakly acid/strongly basic and weakly acid/weakly basic bipolar ion exchange resins with varying acid and basic capacities via subsequent introduction of the exchange active groups in suitable crosslinked skeletal polymers are described.Methylacrylate-styrene-divinylbenzene polymers of varying composition which can be quantitatively chloromethylated and subsequently fully aminated (trimethylamine) and partially saponified in one process step were used as starting polymers for weakly acid/strongly basic resins. The reverse route saponification of the ester groups first, followed by chloromethylation of the aromatic parts of the matrix and animation turned out to the possible, if at all, only for bipolar resins of strongly predominant basic character. The capacity parameters can be controlled through the composition of the matrix.Polymethylacrylates crosslinked with divinylbenzene served as polymer basis of the weakly acid/weakly basic bipolar ion exchange resins. The functionalization was achieved by partial aminolysis with polyamines (dimethylaminopropylamine, ethylenediamine, diethylenetriamine) and saponification with lyes. The number of basic and acid groups which can be introduced is governed primarily by the conditions of the aminolysis. The capacity parameters are controllable within a broad range by the procedures.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19873290315
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  • 9
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    Measurement of the production cross section forZ/γ*in association with jets inppcollisions ats=7  TeVwith the ATLAS detector (2012)
    American Physical Society
    Details
    Publication Date: 2012-02-28
    Print ISSN: 1550-7998
    Electronic ISSN: 1550-2368
    Topics: Physics
    Published by American Physical Society
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  • 10
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    Measurement of the transverse momentum distribution ofWbosons inppcollisions ats=7  TeVwith the ATLAS detector (2012)
    American Physical Society
    Details
    Publication Date: 2012-01-18
    Print ISSN: 1550-7998
    Electronic ISSN: 1550-2368
    Topics: Physics
    Published by American Physical Society
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