@article{SchmittMorasBihlmayeretal.2019, author = {Schmitt, Martin and Moras, Paolo and Bihlmayer, Gustav and Cotsakis, Ryan and Vogt, Matthias and Kemmer, Jeannette and Belabbes, Abderrezak and Sheverdyaeva, Polina M. and Kundu, Asish K. and Carbone, Carlo and Bl{\"u}gel, Stefan and Bode, Matthias}, title = {Indirect chiral magnetic exchange through Dzyaloshinskii-Moriya-enhanced RKKY interactions in manganese oxide chains on Ir(100)}, series = {Nature Communications}, volume = {10}, journal = {Nature Communications}, doi = {10.1038/s41467-019-10515-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230986}, year = {2019}, abstract = {Localized electron spins can couple magnetically via the Ruderman-Kittel-Kasuya-Yosida interaction even if their wave functions lack direct overlap. Theory predicts that spin-orbit scattering leads to a Dzyaloshinskii-Moriya type enhancement of this indirect exchange interaction, giving rise to chiral exchange terms. Here we present a combined spin-polarized scanning tunneling microscopy, angle-resolved photoemission, and density functional theory study of MnO2 chains on Ir(100). Whereas we find antiferromagnetic Mn-Mn coupling along the chain, the inter-chain coupling across the non-magnetic Ir substrate turns out to be chiral with a 120° rotation between adjacent MnO2 chains. Calculations reveal that the Dzyaloshinskii-Moriya interaction results in spin spirals with a periodicity in agreement with experiment. Our findings confirm the existence of indirect chiral magnetic exchange, potentially giving rise to exotic phenomena, such as chiral spin-liquid states in spin ice systems or the emergence of new quasiparticles.}, language = {en} } @article{SchurrSpindlerKurzetal.2019, author = {Schurr, Yvonne and Spindler, Markus and Kurz, Hendrikje and Bender, Markus}, title = {The cytoskeletal crosslinking protein MACF1 is dispensable for thrombus formation and hemostasis}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-44183-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234966}, year = {2019}, abstract = {Coordinated reorganization of cytoskeletal structures is critical for key aspects of platelet physiology. While several studies have addressed the role of microtubules and filamentous actin in platelet production and function, the significance of their crosstalk in these processes has been poorly investigated. The microtubule-actin cross-linking factor 1 (MACF1; synonym: Actin cross-linking factor 7, ACF7) is a member of the spectraplakin family, and one of the few proteins expressed in platelets, which possess actin and microtubule binding domains thereby facilitating actin-microtubule interaction and regulation. We used megakaryocyte- and platelet-specific Macf1 knockout (Macf1fl/fl, Pf4-Cre) mice to study the role of MACF1 in platelet production and function. MACF1 deficient mice displayed comparable platelet counts to control mice. Analysis of the platelet cytoskeletal ultrastructure revealed a normal marginal band and actin network. Platelet spreading on fibrinogen was slightly delayed but platelet activation and clot traction was unaffected. Ex vivo thrombus formation and mouse tail bleeding responses were similar between control and mutant mice. These results suggest that MACF1 is dispensable for thrombopoiesis, platelet activation, thrombus formation and the hemostatic function in mice.}, language = {en} } @article{ScholzCosgareaSuesskindetal.2018, author = {Scholz, S. L. and Cosgarea, I. and S{\"u}ßkind, D. and Murali, R. and M{\"o}ller, I. and Reis, H. and Leonardelli, S. and Schilling, B. and Schimming, T. and Hadaschik, E. and Franklin, C. and Paschen, A. and Sucker, A. and Steuhl, K. P. and Schadendorf, D. and Westekemper, H. and Griewank, K. G.}, title = {NF1 mutations in conjunctival melanoma}, series = {British Journal of Cancer}, volume = {118}, journal = {British Journal of Cancer}, doi = {10.1038/s41416-018-0046-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233329}, pages = {1243-1247}, year = {2018}, abstract = {Background Conjunctival melanoma is a potentially deadly eye tumour. Despite effective local therapies, tumour recurrence and metastasis remain frequent. The genetics of conjunctival melanomas remain incompletely understood. Methods A large cohort of 63 conjunctival melanomas was screened for gene mutations known to be important in other melanoma subtypes by targeted next-generation sequencing. Mutation status was correlated with patient prognosis. Results Frequent mutations in genes activating the MAP kinase pathway were identified. NF1 mutations were most frequent (n = 21, 33\%). Recurrent activating mutations were also identified in BRAF (n = 16, 25\%) and RAS genes (n = 12, 19\%; 11 NRAS and 1 KRAS). Conclusions Similar to cutaneous melanomas, conjunctival melanomas can be grouped genetically into four groups: BRAF-mutated, RAS-mutated, NF1-mutated and triple wild-type melanomas. This genetic classification may be useful for assessment of therapeutic options for patients with metastatic conjunctival melanoma}, language = {en} } @article{SteuerCostaVanderAuweraGlocketal.2019, author = {Steuer Costa, Wagner and Van der Auwera, Petrus and Glock, Caspar and Liewald, Jana F. and Bach, Maximilian and Sch{\"u}ler, Christina and Wabnig, Sebastian and Oranth, Alexandra and Masurat, Florentin and Bringmann, Henrik and Schoofs, Liliane and Stelzer, Ernst H. K. and Fischer, Sabine C. and Gottschalk, Alexander}, title = {A GABAergic and peptidergic sleep neuron as a locomotion stop neuron with compartmentalized Ca2+ dynamics}, series = {Nature Communications}, volume = {10}, journal = {Nature Communications}, doi = {10.1038/s41467-019-12098-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223273}, year = {2019}, abstract = {Animals must slow or halt locomotion to integrate sensory inputs or to change direction. In Caenorhabditis elegans, the GABAergic and peptidergic neuron RIS mediates developmentally timed quiescence. Here, we show RIS functions additionally as a locomotion stop neuron. RIS optogenetic stimulation caused acute and persistent inhibition of locomotion and pharyngeal pumping, phenotypes requiring FLP-11 neuropeptides and GABA. RIS photoactivation allows the animal to maintain its body posture by sustaining muscle tone, yet inactivating motor neuron oscillatory activity. During locomotion, RIS axonal Ca2+ signals revealed functional compartmentalization: Activity in the nerve ring process correlated with locomotion stop, while activity in a branch correlated with induced reversals. GABA was required to induce, and FLP-11 neuropeptides were required to sustain locomotion stop. RIS attenuates neuronal activity and inhibits movement, possibly enabling sensory integration and decision making, and exemplifies dual use of one cell across development in a compact nervous system.}, language = {en} } @article{CarradecPelletierDaSilvaetal.2018, author = {Carradec, Quentin and Pelletier, Eric and Da Silva, Corinne and Alberti, Adriana and Seeleuthner, Yoann and Blanc-Mathieu, Romain and Lima-Mendez, Gipsi and Rocha, Fabio and Tirichine, Leila and Labadie, Karine and Kirilovsky, Amos and Bertrand, Alexis and Engelen, Stefan and Madoui, Mohammed-Amin and M{\´e}heust, Rapha{\"e}l and Poulain, Julie and Romac, Sarah and Richter, Daniel J. and Yoshikawa, Genki and Dimier, C{\´e}line and Kandels-Lewis, Stefanie and Picheral, Marc and Searson, Sarah and Jaillon, Olivier and Aury, Jean-Marc and Karsenti, Eric and Sullivan, Matthew B. and Sunagawa, Shinichi and Bork, Peer and Not, Fabrice and Hingamp, Pascal and Raes, Jeroen and Guidi, Lionel and Ogata, Hiroyuki and de Vargas, Colomban and Iudicone, Daniele and Bowler, Chris and Wincker, Patrick}, title = {A global ocean atlas of eukaryotic gene}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, organization = {Tara Oceans Coordinators}, doi = {10.1038/s41467-017-02342-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222250}, year = {2018}, abstract = {While our knowledge about the roles of microbes and viruses in the ocean has increased tremendously due to recent advances in genomics and metagenomics, research on marine microbial eukaryotes and zooplankton has benefited much less from these new technologies because of their larger genomes, their enormous diversity, and largely unexplored physiologies. Here, we use a metatranscriptomics approach to capture expressed genes in open ocean Tara Oceans stations across four organismal size fractions. The individual sequence reads cluster into 116 million unigenes representing the largest reference collection of eukaryotic transcripts from any single biome. The catalog is used to unveil functions expressed by eukaryotic marine plankton, and to assess their functional biogeography. Almost half of the sequences have no similarity with known proteins, and a great number belong to new gene families with a restricted distribution in the ocean. Overall, the resource provides the foundations for exploring the roles of marine eukaryotes in ocean ecology and biogeochemistry.}, language = {en} } @article{BrunkSputhDooseetal.2018, author = {Brunk, Michael and Sputh, Sebastian and Doose, S{\"o}ren and van de Linde, Sebastian and Terpitz, Ulrich}, title = {HyphaTracker: An ImageJ toolbox for time-resolved analysis of spore germination in filamentous fungi}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, doi = {10.1038/s41598-017-19103-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221691}, year = {2018}, abstract = {The dynamics of early fungal development and its interference with physiological signals and environmental factors is yet poorly understood. Especially computational analysis tools for the evaluation of the process of early spore germination and germ tube formation are still lacking. For the time-resolved analysis of conidia germination of the filamentous ascomycete Fusarium fujikuroi we developed a straightforward toolbox implemented in ImageJ. It allows for processing of microscopic acquisitions (movies) of conidial germination starting with drift correction and data reduction prior to germling analysis. From the image time series germling related region of interests (ROIs) are extracted, which are analysed for their area, circularity, and timing. ROIs originating from germlings crossing other hyphae or the image boundaries are omitted during analysis. Each conidium/hypha is identified and related to its origin, thus allowing subsequent categorization. The efficiency of HyphaTracker was proofed and the accuracy was tested on simulated germlings at different signal-to-noise ratios. Bright-field microscopic images of conidial germination of rhodopsin-deficient F. fujikuroi mutants and their respective control strains were analysed with HyphaTracker. Consistent with our observation in earlier studies the CarO deficient mutant germinated earlier and grew faster than other, CarO expressing strains.}, language = {en} } @article{ChinaBurrowsWangetal.2018, author = {China, Swarup and Burrows, Susannah M. and Wang, Bingbing and Harder, Tristan H. and Weis, Johannes and Tanarhte, Meryem and Rizzo, Luciana V. and Brito, Joel and Cirino, Glauber G. and Ma, Po-Lun and Cliff, John and Artaxo, Paulo and Gilles, Mary K. and Laskin, Alexander}, title = {Fungal spores as a source of sodium salt particles in the Amazon basin}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, doi = {10.1038/s41467-018-07066-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222492}, year = {2018}, abstract = {In the Amazon basin, particles containing mixed sodium salts are routinely observed and are attributed to marine aerosols transported from the Atlantic Ocean. Using chemical imaging analysis, we show that, during the wet season, fungal spores emitted by the forest biosphere contribute at least 30\% (by number) to sodium salt particles in the central Amazon basin. Hydration experiments indicate that sodium content in fungal spores governs their growth factors. Modeling results suggest that fungal spores account for ~69\% (31-95\%) of the total sodium mass during the wet season and that their fractional contribution increases during nighttime. Contrary to common assumptions that sodium-containing aerosols originate primarily from marine sources, our results suggest that locally-emitted fungal spores contribute substantially to the number and mass of coarse particles containing sodium. Hence, their role in cloud formation and contribution to salt cycles and the terrestrial ecosystem in the Amazon basin warrant further consideration.}, language = {en} } @article{BruchhagenJarickMewisetal.2018, author = {Bruchhagen, Christin and Jarick, Marcel and Mewis, Carolin and Hertlein, Tobias and Niemann, Silke and Ohlsen, Knut and Peters, Georg and Planz, Oliver and Ludwig, Stephan and Ehrhardt, Christina}, title = {Metabolic conversion of CI-1040 turns a cellular MEK-inhibitor into an antibacterial compound}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, doi = {10.1038/s41598-018-27445-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221648}, year = {2018}, abstract = {Influenza virus (IV) infections cause severe respiratory illnesses that can be complicated by bacterial super-infections. Previously, we identified the cellular Raf-MEK-ERK cascade as a promising antiviral target. Inhibitors of MEK, such as CI-1040, showed potent antiviral activity. However, it remained unclear if this inhibitor and its active form, ATR-002, might sensitize host cells to either IV or secondary bacterial infections. To address these questions, we studied the anti-pathogen activity of ATR-002 in comparison to CI-1040, particularly, its impact on Staphylococcus aureus (S. aureus), which is a major cause of IV super-infections. We analysed IV and S. aureus titres in vitro during super-infection in the presence and absence of the drugs and characterized the direct impact of ATR-002 on bacterial growth and phenotypic changes. Importantly, neither CI-1040 nor ATR-002 treatment led to increased bacterial titres during super-infection, indicating that the drug does not sensitize cells for bacterial infection. In contrast, we rather observed reduced bacterial titres in presence of ATR-002. Surprisingly, ATR-002 also led to reduced bacterial growth in suspension cultures, reduced stress- and antibiotic tolerance without resistance induction. Our data identified for the first time that a particular MEK-inhibitor metabolite exhibits direct antibacterial activity, which is likely due to interference with the bacterial PknB kinase/Stp phosphatase signalling system.}, language = {en} } @article{CastilhoHochleitnerWilsonetal.2018, author = {Castilho, Miguel and Hochleitner, Gernot and Wilson, Wouter and van Rietbergen, Bert and Dalton, Paul D. and Groll, J{\"u}rgen and Malda, Jos and Ito, Keita}, title = {Mechanical behavior of a soft hydrogel reinforced with three-dimensional printed microfibre scaffolds}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, doi = {10.1038/s41598-018-19502-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222280}, year = {2018}, abstract = {Reinforcing hydrogels with micro-fibre scaffolds obtained by a Melt-Electrospinning Writing (MEW) process has demonstrated great promise for developing tissue engineered (TE) constructs with mechanical properties compatible to native tissues. However, the mechanical performance and reinforcement mechanism of the micro-fibre reinforced hydrogels is not yet fully understood. In this study, FE models, implementing material properties measured experimentally, were used to explore the reinforcement mechanism of fibre-hydrogel composites. First, a continuum FE model based on idealized scaffold geometry was used to capture reinforcement effects related to the suppression of lateral gel expansion by the scaffold, while a second micro-FE model based on micro-CT images of the real construct geometry during compaction captured the effects of load transfer through the scaffold interconnections. Results demonstrate that the reinforcement mechanism at higher scaffold volume fractions was dominated by the load carrying-ability of the fibre scaffold interconnections, which was much higher than expected based on testing scaffolds alone because the hydrogel provides resistance against buckling of the scaffold. We propose that the theoretical understanding presented in this work will assist the design of more effective composite constructs with potential applications in a wide range of TE conditions.}, language = {en} } @article{CiuchiDiSanteDobrosavljevićetal.2018, author = {Ciuchi, Sergio and Di Sante, Domenico and Dobrosavljević, Vladimir and Fratini, Simone}, title = {The origin of Mooij correlations in disordered metals}, series = {npj Quantum Materials}, volume = {3}, journal = {npj Quantum Materials}, doi = {10.1038/s41535-018-0119-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223148}, year = {2018}, abstract = {Sufficiently disordered metals display systematic deviations from the behavior predicted by semi-classical Boltzmann transport theory. Here the scattering events from impurities or thermal excitations can no longer be considered as additive-independent processes, as asserted by Matthiessen's rule following from this picture. In the intermediate region between the regime of good conduction and that of insulation, one typically finds a change of sign of the temperature coefficient of resistivity, even at elevated temperature spanning ambient conditions, a phenomenology that was first identified by Mooij in 1973. Traditional weak coupling approaches to identify relevant corrections to the Boltzmann picture focused on long-distance interference effects such as "weak localization", which are especially important in low dimensions (1D and 2D) and close to the zero-temperature limit. Here we formulate a strong-coupling approach to tackle the interplay of strong disorder and lattice deformations (phonons) in bulk three-dimensional metals at high temperatures. We identify a polaronic mechanism of strong disorder renormalization, which describes how a lattice locally responds to the relevant impurity potential. This mechanism, which quantitatively captures the Mooij regime, is physically distinct and unrelated to Anderson localization, but realizes early seminal ideas of Anderson himself, concerning the interplay of disorder and lattice deformations.}, language = {en} }