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1.
Marco Dogs Bernd Wemheuer Laura Wolter Nils Bergen Rolf Daniel Meinhard Simon Thorsten Brinkhoff 《Systematic and applied microbiology》2017,40(6):370-382
Macroalgae harbour specific microbial communities on their surface that have functions related to host health and defence. In this study, the bacterial biofilm of the marine brown alga Fucus spiralis was investigated using 16S rRNA gene amplicon-based analysis and isolation of bacteria. Rhodobacteraceae (Alphaproteobacteria) were the predominant family constituting 23% of the epibacterial community. At the genus level, Sulfitobacter, Loktanella, Octadecabacter and a previously undescribed cluster were most abundant, and together they comprised 89% of the Rhodobacteraceae. Supported by a specific PCR approach, 23 different Rhodobacteraceae-affiliated strains were isolated from the surface of F. spiralis, which belonged to 12 established and three new genera. For seven strains, closely related sequences were detected in the 16S rRNA gene dataset. Growth experiments with substrates known to be produced by Fucus spp. showed that all of them were consumed by at least three strains, and vitamin B12 was produced by 70% of the isolates. Since growth of F. spiralis depends on B12 supplementation, bacteria may provide the alga with this vitamin. Most strains produced siderophores, which can enhance algal growth under iron-deficient conditions. Inhibiting properties against other bacteria were only observed when F. spiralis material was present in the medium. Thus, the physiological properties of the isolates indicated adaption to an epiphytic lifestyle. 相似文献
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Ryszard Slomski Ingrid Braulke Claudia Behrend Elisabeth Schröder Jean-Pierre Colombo Jochen Reiss 《Human genetics》1992,89(6):632-634
Summary A girl with ornithine transcarbamylase (OTC) deficiency was investigated for molecular and cytogenetic abnormalities that might explain this phenotype. Analysis with polymorphic DNA markers indicated that the patient did not inherit paternal alleles of the OTC locus, but that she did inherit the proximal locus DXS7 and the long arm of chromosome X. High-resolution cytogenetic analysis of the patient indicated a deletion of Xp11.4-p21, whereas both parents had normal karytoypes. Since the mother might be heterozygous according to biochemical tests, a second mutation within the maternal OTC gene cannot be excluded. 相似文献
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Experimental and Theoretical Assessment of Ni‐Based Binary Compounds for the Hydrogen Evolution Reaction 下载免费PDF全文
Marc Ledendecker Hannah Schlott Markus Antonietti Bernd Meyer Menny Shalom 《Liver Transplantation》2017,7(5)
Metallic binary compounds have emerged in recent years as highly active and stable electrocatalysts toward the hydrogen evolution reaction. In this work, the origin of their high activity from a theoretical and experimental point of view is elucidated. Here, different metallic ceramics as Ni3S2, Ni3N, or Ni5P4 are grown directly on Ni support in order to avoid any contaminations. The correlation of theoretical calculations with detailed material characterization and electrochemical testing paves the way to a deeper understanding of possible active adsorption sites for each material and the observed catalytic activity. It is shown that heteroatoms as P, S, and N actively take part in the reaction and do not act as simple spectator. Due to the anisotropic nature of the materials, a variety of adsorption sites with highly coverage‐dependent properties exists, leading to a general shift in hydrogen adsorption free energies ΔG H close to zero. Extending the knowledge gained about the here described materials, a new catalyst is prepared by modifying a high surface Ni foam, for which current densities up to 100 mA cm?2 at around 0.15 V (for Ni3N) are obtained. 相似文献
6.
Assortative mating preferences between colour morphs of the endemic Lake Tanganyika cichlid genus Tropheus 总被引:1,自引:1,他引:0
Bernd Egger Beate Obermüller Eva Eigner Christian Sturmbauer Kristina M. Sefc 《Hydrobiologia》2008,615(1):37-48
Female mate preferences effectuate reproductive isolation among and sexual selection within species. Both mechanisms have
been associated with the diversification and speciation of cichlid species flocks of the East African Great Lakes. In Lake
Tanganyika, the endemic genus Tropheus has diversified into >100 geographic colour morphs. Although distributed allopatrically at present, water level fluctuations
have repeatedly displaced and merged the benthic, rock-dwelling populations. Tests for assortative mating were performed to
explore the potential for reproductive isolation between morphs in secondary contact, and to assess the importance of sexual
selection for the diversification of this group. In contrast to other haplochromine cichlids, Tropheus is a sexually monochromatic, territorial and maternally mouthbrooding fish, which establishes temporary pair bonds prior
to spawning. Female mate preference trials involved two-way choices between a homotypic and a heterotypic male and were conducted
on allopatric populations of red and blue morphs from the southern part of Lake Tanganyika. Female affiliation time near each
male’s compartment did not predict the mate preferences subsequently expressed in unrestrained interactions after removal
of the compartment separators (spawning, pseudospawning and courtship). Consequently, mate preferences were inferred from
unrestrained interactions with one test male at a time in replicate observation sessions. Of the 23 females tested, 13 courted,
pseudospawned or spawned with the homotypic male, one blue female courted a red male, and nine females expressed no sexual
motivation. The assortative mate preferences in the experiments (P < 0.01) suggest that colour differentiation between Tropheus populations can effectuate reproductive isolation, and is consistent with the notion that sexual selection contributed to
the diversification of the genus.
Guest editors: T. Wilke, R. V?in?l? & F. Riedel
Patterns and Processes of Speciation in Ancient Lakes: Proceedings of the Fourth Symposium on Speciation in Ancient Lakes,
Berlin, Germany, September 4–8, 2006 相似文献
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Dynorphin-Related Opioid Peptides in the Neurointermediate Pituitary of Rats Are Not α-N-Acetylated 总被引:1,自引:1,他引:0
Immunoreactive dynorphin in the neurointermediate pituitary of rats was found to consist of four different molecular weight forms. The three larger molecular weight forms, with apparent molecular weights of 4800, 3200, and 1700, constituted more than 80% of the total dynorphin immunoreactivity, and each liberated leucine-enkephalin but not alpha-N-acetyl-leucine-enkephalin upon enzymatic treatment with trypsin followed by carboxypeptidase B. Only a minor portion of the smallest dynorphin-related molecular weight form, dynorphin-(1-8), released alpha-N-acetyl-leucine-enkephalin upon enzymatic cleavage. This suggests that the vast majority of dynorphin-related peptides in the rat neurointermediate pituitary is not alpha-N-acetylated. The exceptionally high opiate-like activity of the molecular weight 1700 dynorphin suggests that this dynorphin-related opioid peptide may constitute the major part of opioid activity in the neurointermediate pituitary of rats. 相似文献
9.
P Exadaktylos O Schlette W Rumler R Weidhase J Haerting T Reiss I Heinrichs 《Folia haematologica (Leipzig, Germany : 1928)》1987,114(5):610-616
1. As compared with the peripheral blood lymphocytes of healthy subjects the cells in the mononuclear fraction of peripheral blood and in the bone marrow of children with ANLL show a significant higher S- and G2 + M-phase. 2. A high proliferative activity correlate with a bad prognosis or with reaching no haematological remission. 3. Frequently, aneuploid cell populations will occur in the morphological subtypes M 4 and M 5. 相似文献